amq abs paoli tepro 231-234.pub available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 231 234 the february 1st, 2014 panicaglia landslide at borgo san lorenzo (mugello) luigi paoli freelancer geologist, via aldo moro 3 borgo san lorenzo, firenze, italy corresponding author: l. paoli <luigipaoli@aruba.it> abstract: on february 1st, 2014 a massive landslide occurred in the area of panicaglia, borgo san lorenzo (mugello, tuscany), involving roads and related subservices, residential and other private buildings that collapsed or were seriously damaged and evacuated. the phenomenon affected the western edge of the fluvial terrace surface and the underlying slope, cut in lacustrine, fluvio-lacustrine and alluvial deposits, on the hydrographical left side of le cale creek (left tributary of the sieve river). geometric, lithostratigraphic, geotechnical and geophysical features of the landslide were analyzed through a survey campaign carried out for the municipality of borgo san lorenzo. keywords: landslides, fluvial terrace, fluvio-lacustrine deposits, plio-quaternary mugello basin, northern apennines, flat dilatometer test dmt 1. introduction on february 1st, 2014 a landslide affected the entire western side of the village of panicaglia (borgo san lorenzo, florence). the landslide involved roads and related subservices, residential and other private buildings that collapsed or were serioulsly damaged and evacuated. the landslide occurred after an important meteoric event that led to conditions of substantial soil saturation. here we report the main results of the geological investigations carried out for the municipality of borgo san lorenzo, that aimed at the reconstruction of the landslide geometry and at establishing geotechnical soil properties for remedial measures planning and designing. 2. geological setting the investigated area lies in the central part of the plio-quaternary, fluvio-lacustrine mugello basin (martini & sagri, 1994), on the western edge of the surface of a fluvial terrace (“terrazzo rissiano” sanesi, 1965), cut by le cale creek and two left tributaries of the same stream, between about 285 m a.s.l. and about 235 m a.s.l. on the terrace surface, alluvial deposits mainly gravel with sandy-silty matrix, ca. 12 m thick, crop out. alluvial deposits are attributable to sieve river synthem, scarperia subsynthem, latest early pleistocene (?)-middle pleistocene (after abbazzi et al., 1995; bortolotti et al., 2010). the depositional environment of these sediments is of the braided-river type. these deposits overlie, by unconformable erosional contact, fluvio-lacustrine deposits of the mugello basin synthem, pulicciano subsynthem, lower pleistocene. fluviolacustrine deposits (see benvenuti, 1997; benvenuti, 2003) mainly consist of gravels with silty-sandy matrix in the upper layers, here up to 9 m thick, that pass down to silty-clayey textures, with sandy-silty intercalations, overconsolidated and fissured. fluvio-lacustrine sediments relate to fan, fan-delta, delta front and lake depositions (benvenuti, 2003). the thickness of fluvio-lacustrine deposits was estimated here to be about 400 m (gemina, 1962). halfway up the slope there is another terrace consisting of alluvial deposits, gravels with sandy -silty matrix, silty sands and clayey silts, ca. 8 m thick, referable to sieve river synthem, luco di mugello subsynthem, middle-upper pleistocene (“terrazzo wurmiano” sanesi, 1965). on the valley floor, near le cale creek, there is a further terrace consisting of mainly gravelly alluvial deposits, ca. 5 m thick, referable to the sieve river synthem, sagginale subsynthem, upper pleistocene(?)-holocene (“terrazzo olocenico” sanesi, 1965). on the scarp and the underlying slope, eluvial-colluvial deposits and anthropic deposits up to about 10 m thick occur. 3. materials and methods the survey campaign consisted in the execution of: i) a conventional topographic survey, with a detailed field mapping of the landslide geomorphological features, ii) cores for a total length of 200 m, iii) 32 standard penetration tests (spt), iv) 3 flat dilatometer tests (dmt), v) 4 electrical cone penetrometer tests (ecpt), vi), geotechnical laboratory tests on 20 collected soil samples, vii) 6 refraction seismic prospecting for a total length of 728.5 m, viii) 1 down hole (50 m), ix) 1 ambient noise horizontalto-vertical spectral ratio (hvsr) measurement. a total of 6 inclinometer casings and 8 open piezohttps://doi.org/10.26382/aiqua.2018.aiquaconference meters have been installed and monitoring during the last four years. 4. results 4.1 morphology of the panicaglia landslide the landslide crown (according to varnes, 1978) develops over a total length of about 320 m and involves the morphologic scarp that delimits the upper terrace surface, from the top, towards the north, down to its base, and then affects the underlying slope. the landslide body extends downhill involving the morphologic scarp that constitutes the upper boundary of the alluvial floodplain of the le cale creek. the length of the landslide body, from the crown to the toe, is about 150 m. the zone involved in the landslide covers an area of about 42.000 m², with an approximate volume of 250.000 m3. the main scarp has a break at a distance of about 180 m from the crown. about 30 m further downhill, there is another scarp that continues up to the ditch that delimits the landslide area to the south. the height of the main scarp, which has progressively increased in the development of the phenomenon, has reached a maximum of about 3.5 m in the north portion of failure, where the primary plastic deformations of the head and of the landslide body occur. proceeding southwards, the height of the main scarp lowers to about 1 m. another characteristic element of the landslide is a fracture antithetical to the crown, which develops parallel to it, at a distance of about 15÷20 m. the landslide foot is not clearly identifiable. the landslide toe, consisting of a swelling to a maximum height of about 1 m, only delineated in the initial phases of the phenomenon, affects the slope that delimits upstream the floodplain of the le cale creek. the landslide is of a complex type, ascribable to rotational slide (in the upper part, with subvertical breaking surface) and to translational slide (in the lower part, with a subparallel sliding surface to the slope). some surficial features, like ondulations, counterslopes and steps, can be referred to previous gravitational activity, index of an active slope dynamics. these quiescent features were reactivated during the 2014 event. the memory of landslides that have affected buildings and pre-existing artefacts in the previous decades points to conditions of generalized instability of the morphological scarp and the underlying areas. 4.2 depth of the sliding surface the sliding surfaces stand at about 16÷18 m from the ground surface in the upper part of the slope, close to the morphological scarp, at about 10÷12 m in the 232 fig. 1 panicaglia landslide geologic map. paoli l. 233 middle section, and at about 4 m in the lower part. the failure surfaces show a subvertical trend in the upper part of the slope, conditioned by the release of overburden pressure determined by the presence of the morphological scarp and by the joints system that involved the gravelly-sandy deposits of the upper terrace, and then assume a subparallel trend to ground surface in the mid-slope and in the foot slope. the slip surfaces, set near the contact between the coarse textured fluvial and fluvio-lacustrine units and the underlying fine textured lacustrine deposits, were already identified during the execution of field geognostic surveys and subse the panicaglia landslide fig. 2 panicaglia landslide geomorphological map (topographic base map is regione toscana technical map – ctr, enhanced with conventional topographical survey). fig. 3 a) dmt-kd method for detecting slip surface in oc clay slopes from totani et al., 1997 b) detecting failure surfaces by dmt in the panicaglia site. quently verified by slope inclinometer data. the results of the investigations allowed us to test, in particular, the reliability of the dmt (marchetti, 1980; astm, 1986) to diagnose, quickly and at relatively low cost, the presence of active or previous sliding surfaces in overconsolidated clay slopes (see totani et al., 1997; marchetti, 1999). 5. discussion and conclusion the lithologic and stratigraphic discontinuity between coarse textured fluvial and fluvio-lacustrine deposits and the underlying fine-textured lacustrine deposits constitutes the weak element of all the slope system. a clear contrast between geotechnical granular behaviour of the upper unit and the cohesive behaviour of the lower unit is evident here. the complex gravitational phenomenon tends to reactivate periodically with the rising of the ground-water table, when conditions of saturation occur close to the ground surface below the morphologic scarp. a sudden increase in porewater pressure along the slip surfaces causes a decrease of soil residual shear strength thus triggering a new failure. landslide shows a state of substantial dormancy once the masses have been rebalanced and the piezometric levels lowered. such an evolution of the phenomenon, with phases of paroxysmal activity triggered by critical meteorological conditions, alternating with periods of dormancy, was also observed for other gravitational movements occurring in similar geomorphological and lithostratigraphic contexts that are very common in mugello. acknowledgements i wish to thank the municipality of borgo san lorenzo for the authorization to data publishing. references abbazzi l., benvenuti m., rook l., masini f. (1995) biochronology of the mugello intermontane basin (northern apennines, italy). il quaternario, 8(1), 510. astm subcommittee d 12.02.10 (1986) schmertmann j.h., chairman suggested method for performing the flat dilatometer test, astm geotechnical testing journal, 9 (2), 93-101 june. benvenuti m. (1997) physical stratigraphy of the fluviolacustrine mugello basin (plio-pleistocene, northern apennines, italy). giornale di geologia, ser. 3°, 59 (1-2), 91-111. benvenuti m. (2003) facies analysis and tectonic significance of lacustrine fan-deltaic successions in the pliocene-pleistocene mugello basin, central italy. sedimentary geology, 157, 197-234. bortolotti v., poccianti c., principi g., sani f. (edited by) (2010) note illustrative della carta geologica d’italia alla scala 1: 50.000 foglio 264 borgo san lorenzo. ispra istituto superiore per la protezione e la ricerca ambientale servizio geologico d’italia, la nuova lito, firenze, pp. 104. gemina (1962) il bacino del mugello. in: ligniti e torbe dell’italia continentale. roma, 61-70. marchetti s. (1980) in situ tests by flat dilatometer. j. geotech. engng div., asce, 106(3), 299-321. marchetti s. (1999) the flat dilatometer (dmt) and its applications to geotechnical design. japanese geotechnical society, tokyo, pp. 90. martini p.i., sagri m. (1994) the late miocenepleistocene extensional basins of the northern apennines: facies distribution and fill architecture. memorie società geologica italiana, 48, 375-380. sanesi g. (1965) geologia e morfologia dell’antico bacino lacustre del mugello firenze. bollettino società geologica italiana., 84 (3), 169-252. totani g., calabrese m., marchetti s., monaco p. (1997) use in-situ flat dilatometer (dmt) for ground characterization in the stability analysis of slope. xv icsmfe, hambourg, september 1997, 1, 607-610. varnes d.j. (1978) slope movement. types and processes. in schuster r.l., krizek r.j. landslides. analysis and control. spec. rep. 176, nat. acad. of sciences, washington d.c. 234 paoli l. ms. received: may 17, 2018 final text received: may 22, 2018 sess 1_160211.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 post-lgm valley fills from the northern coast of tuscany: depositional facies and stratigraphic architecture alessandro amorosi1, veronica rossi1, giovanni sarti2 & roberto mattei2 1 dipartimento di scienze della terra e geologico-ambientali, university of bologna, italy 2 dipartimento di scienze della terra, university of pisa, italy corresponding author: a. amorosi <alessandro.amorosi@unibo.it> abstract: amorosi a. et al., post-lgm valley fills from the northern coast of tuscany: depositional facies and stratigraphic architecture. (it issn 0349-3356, 2011) the stratigraphic architecture of three adjacent valley bodies of post-lgm age buried beneath the northern coast of tuscany is illustrated in detail. above a gravel fluvial deposit, the valley fills exhibit a distinctive succession of coastal plain to estuarine facies, punctuated by an aggradational stacking pattern of millennial-scale depositional cycles with distinctive climatic signature. radiocarbon dates document that the three valleys were active simultaneously and that rapidly created accommodation during transgression was filled under conditions of very high sediment supply. riassunto: amorosi a. et al., riempimenti vallivi tardoquaternari nel sottosuolo della piana costiera toscana: facies e architettura deposizionale. (it issn 0349-3356, 2011) il sottosuolo della costa toscana tra pisa e viareggio è caratterizzato da tre paleovalli, formatesi nel corso dell’ultimo ciclo glaciale-interglaciale. al di sopra di facies ghiaiose di canale fluviale, il riempimento delle paleovalli presenta un impilamento aggradazionale di parasequenze di piana costiera ed estuarine, formatesi in risposta a oscillazioni climatiche e del livello marino di durata circa millenaria. datazioni al radiocarbonio mostrano che le tre paleovalli furono attive contemporaneamente e che il loro riempimento avvenne durante la risalita del livello del mare in condizioni di elevato apporto sedimentario. key words: valley fill, sequence stratigraphy, parasequence, quaternary, tuscany parole chiave: riempimento di valle, stratigrafia sequenziale, parasequenza, quaternario, toscana 1. introduction the three-dimensional stratigraphic architecture of late quaternary valley fills has received increasing attention in the past decade, following the development of several sequence-stratigraphic models during the 1990s (van wagoner et al. 1990; dalrymple et al. 1994; zaitlin et al. 1994). however, given the difficulties in performing accurate geometric characterization of quaternary valley bodies on-land, where studies are mostly conducted on the basis of core analysis (gibling 2006), most examples of quaternary incised-valley fills stem primarily from offshore seismic investigations. after the early work by bellotti et al. (1994), milli (1997) and milli et al. (2008) on the tiber coastal plain, detailed facies documentation of late quaternary valley-fill sequences from the northern tyrrhenian coast has been recently provided by aguzzi et al. (2007) and amorosi et al. (2008; 2009) for the arno river system. this paper expands from previous work in the tuscan area, extending stratigraphic analysis of the post-last glacial maximum (post-lgm) succession to a 30 km-long transect, approximately parallel to the present tyrrhenian sea shoreline, from pisa to viareggio. this transect enables the comparison of the stratigraphic architecture beneath three adjacent river systems: arno, serchio and stiavacamaiore. 2. material and methods a dataset consisting of 2,600 stratigraphic data, with 40 continuously-cored reference boreholes, was used for this study. a wealth of information exists for the pisa area and the arno river. conversely, lower density stratigraphic data are available for serchio and camaiore-stiava river systems. in addition to the arno river (242 km long and with water discharge of about 110 m3/ sec), the study area includes serchio river (length: 111 km, discharge: 46 m3/sec) and camaiorestiava river basins. arno and serchio rivers are the main fluvial courses of northern tuscany, with catchment areas of 8228 km2 and 1400 km2, respectively. in contrast, camaiore river is just 19 km long, while stiava river is even shorter. facies characterization of the post-lgm succession also benefited from the analysis of the meiofauna (benthic foraminifers and ostracods) found within five reference cores (bergamin et al., 2006; amorosi et al., 2009). a total of twenty-five radiocarbon dates previously published in bergamin et al. (2006), mariotti lippi (2007) and amorosi et al. (2009) allowed to tie facies interpretation from cored wells into a sequence 8 10 9 stratigraphic framework. 3. post-lgm facies architecture stratigraphic correlation of core data collected along a cross-section transversal to the present fluvial-channel axes enables the identification of a suite of genetically related valley bodies that fill the incisions formed by arno, serchio and camaiorestiava rivers during the last glacial/interglacial cycle. valley bodies are 5 to 10 km wide and 30 to 45 m thick, with width/thickness ratios of about 100 -300. on the basis of facies analysis and palaeontologic characteristics, the valley fills can be subdivided into a series of millennial-scale depositional cycles (see amorosi et al. 2009). these cycles show that valley filling was associated with alternating freshwater and brackish conditions. individual small-scale cycles, about 10 m thick, are bounded by flooding surfaces (parasequences sensu van wagoner et al., 1990) and display similar facies architecture, with sharp-based central/outer estuarine clays grading upwards into inner-estuary and coastal-plain deposits. facies architecture within the valley bodies shows an aggradational, rather than retrogradational, stacking pattern of parasequences. diagnostic changes in vegetation patterns enable documentation of small-scale cycle development as a function of climate change (amorosi et al., 2009). particularly, pollen spectra show expansions of broad-leaved forests at parasequence boundaries, suggesting that rapid shifts to warmer climate conditions accompanied episodes of rapid sea-level rise. in contrast, stillstand phases saw the development of coldtemperate communities (upper parts of parasequences). the sedimentary response to these short-term phases of climatic cooling is documented by episodes of widespread coastalplain and bay-head delta progradation, which led to partial estuary infilling and temporary establishment of continental environments in the proximal and central sectors of the valleys. 4. sequence stratigraphy the post-lgm succession overlies alluvial deposits assigned to the last phase of base-level fall and subsequent lowstand. however, it can not be ruled out that part of the fluvial gravel bodies accumulated under early transgressive conditions. on the interfluves separating the major valley bodies the three deeply incised erosional surfaces (sequence boundary) pass into correlative subaerial exposure surfaces, characterized by indurated and weathered horizons associated with significant stratigraphic hiatuses. at these locations the sequence boundary merges with the transgressive erosional surface, marking the evolution of the incised-valley systems into wavedominated estuaries. the lower transgressive systems tract (tst), which accumulated between ca. 13,000 and 7,800 cal yr bp, records the progressive infilling and drowning of the tuscan paleovalleys in response to the rapid post-glacial sea-level rise. the three valley fills exhibit a composite succession of organic-rich muds formed in a coastal-plain or inner-estuarine environment, with upper transition to centraland outer-estuarine clays (lower tst). an aggradational stacking pattern of high-frequency depositional cycles within the valley fills suggests that sediment supply to the estuaries kept pace with increasing accommodation due to rapid sea-level rise in the early stages of transgression. the upper tst, which marks the change from an aggradational to a retrogradational depositional style, is characterized by a marked deepeningupward tendency (transition to thin nearshore and shallow-marine deposits) and by a typical erosional lower boundary (wave ravinement surface). the maximum flooding surface separates the tst from the overlying highstand systems tract (hst). its age is very well constrained in all valley fills around 7,800 years bp on the basis of radiocarbon dates. this almost isochronous surface, which represents the holocene peak of transgression in the study area, has no obvious physical expression, but can be easily identified from core samples containing the most marine-influenced microfossil assemblage. 5. conclusions few studies have dealt with synchronous valley incision and filling during the last glacial/interglacial cycle as deduced from borehole data. close examination of a valuable stratigraphic dataset beneath the tuscan coastal plain penetrating the post-lgm succession shows the presence of three coexisting incised-valley systems oriented roughly normal to the present shoreline. the application of sequence-stratigraphic analysis through the identification of significant stratigraphic surfaces enables the interpretation of depositional-facies origin and distribution of the post-lgm succession in the study area. above lowstand/early transgressive fluvial deposits, the three valley fills share a common depositional style, including a transgressive succession of innerto outer-estuary facies. where high-resolution core descriptions are available, including micropaleontological and pollen characterization, depositional cycles of lower rank (parasequences) can be delineated within the valley bodies. the vertical succession of facies suggests that the three valleys experienced a common depositional history. fluvial incision post-lgm valley fills from the northern coast of ... 10 occurred close to or during the lgm, while wavedominated estuaries developed into the valley systems during the ensuing post-lgm phase of sea-level rise. the three valley fills keep record of very high sedimentation rates (about 1 cm/year). sediment supply kept pace with sea-level rise during the early stages of transgression, leading to a distinctive aggradational (and even weakly progradational) facies architecture within the valley bodies. references aguzzi m., amorosi a., colalongo m.l., ricci lucchi m., rossi v., sarti g. & vaiani s.c. (2007) late quaternary climatic evolution of the arno coastal plain (western tuscany, italy) from subsurface data. sedimentary geology, 211, 211–229. amorosi a., sarti g., rossi v. & fontana v. (2008) anatomy and sequence stratigraphy of the late quaternary arno valley fill (tuscany, italy). in: a. amorosi, b.u. haq and l. sabato (eds.) advances in application of sequence stratigraphy in italy. geoacta special publication, 1, 55–66. amorosi a., ricci lucchi m., rossi v. & sarti g. (2009) climate change signature of small-scale parasequences from lateglacial-holocene transgressive deposits of the arno valley fill. palaeo3, 273, 142–152. bellotti p., chiocci f.l., milli s., tortora p. & valeri p. (1994) sequence stratigraphy and depositional setting of the tiber delta: integration of high-resolution seismics, well logs, and archaeological data. journal of sedimentary research, 64, 416–432. bergamin l., di bella l., frezza v., devoti s., nisi m.f., silenzi s., carboni m.g. (2006) late quaternary palaeoenvironmental evolution at the versilian coast (tuscany, italy). in: micropalaentological proxies: proceedings of the second and third italian meetings on environmental micropaleontology-grzybowski foundation special publications, 11, 1–11. dalrymple r.w., boyd r. & zaitlin b.a. (1994) history of research, types and internal organization of incised-valley systems: introduction to the volume. in: r.w. dalrymple r. boyd & b.a. zaitlin (eds.) incised-valley systems: origin and sedimentary sequences. sepm special publication, 51, 3–10. gibling m.r. (2006) width and thickness of fluvial channel bodies and valley fills in the geological record: a literature compilation and classification. journal of sedimentary research, 76, 731–770. mariotti lippi m., guido m., menozzi b.i., bellini c. & montanari c. (2007) the massaciuccoli holocene pollen sequence and the vegetation history of the coastal plains by the mar ligure (tuscany and liguria, italy). vegetation history and archaeobotany, 16, 267– 277. milli s. (1997) depositional setting and high-frequency sequence stratigraphy of the middle-upper pleistocene to holocene deposits of the roman basin. geologica romana, 33, 99-136. milli s., moscatelli m., palombo m.r., parlagreco l. & paciucci m. (2008) incised valleys, their filling and mammal fossil record: a case study from middle-upper pleistocene deposits of the roman basin (latium, italy). in: a. amorosi, b.u. haq and l. sabato (eds.) advances in application of sequence stratigraphy in italy. geoacta special publication, 1, 67-87. van wagoner j.c., mitchum r.m., campion k.m. & rahmanian v.d. (1990) siliciclastic sequence stratigraphy in well logs, cores and outcrops: concepts for high resolution correlations of time and facies. american association of american petroleum geologists, methods in exploration 7, tulsa, u.s.a. zaitlin b.a., dalrymple r.w., & boyd r. (1994) the stratigraphic organization of incised-valley systems associated with relative sea-level change. in: r.w. dalrymple, r. boyd and b.a. zaitlin (eds.) incisedvalley systems: origin and sedimentary sequences. sepm special publication, 51, 45–60. ms. received: january 15, 2011 testo ricevuto il 15 gennaio 2011 a. amorosi et al. available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 23 26 late quaternary geology and morphoevolution of the volturno coastal plain, southern italy giuseppe corrado 1 , sabrina amodio 1 , pietro p.c. aucelli 1 , pietro incontri 1 , gerardo pappone 1 , marcello schiattarella 2 1 dipartimento di scienze e tecnologie, parthenope university, naploli, italy 2 dipartimento delle culture europee e del mediterraneo (dicem), basilicata university, matera, italy corresponding author: g. corrado <giuseppe.corrado@uniparthenope.it> abstract: the volturno alluvial-coastal plain is a relevant feature of the tyrrhenian side of southern italy. its plan-view squared shape is due to pliocene-quaternary block-faulting of the western flank of the chain. the quaternary infill of the volturno plain has been here studied by means of well data. an asymmetrical shape of its ancient morphology – with a steeper slope toward the north-west border – and the lack of coincidence between the present course of the volturno river and the main buried bedrock incision are significant achievements of this study. landforms analysis completed the frame of the recent evolution of the plain. keywords: well log correlation, late quaternary evolution, volturno coastal plain, southern italy 1. introduction the alluvial-coastal plain of the volturno river is a relevant feature of the tyrrhenian side of the italian south-apennine chain. in a planimetric view, it has a roughly quadrangular shape, due to pliocenequaternary block-faulting of the western flank of the orogen after the tertiary extension of the back-arc basin. the plain is in fact bordered by the structural highs of mt. massico and caserta mts to the north-west and north-east, respectively, and by the ischia island phlegraean fields volcanic alignment to the south-east. this area has already been studied and the state-of-art literature is proposed in santangelo et al. (2017). several authors investigated the infill stratigraphy of such a structural depression by means of borehole analysis (romano et al., 1994; barra et al., 1996; santangelo et al., 2010; amorosi et al., 2012; sacchi et al., 2014). the absence of pliocene marine deposits in the deepest boreholes suggests that the plain was above sea level during late tertiary times. anyway, during the quaternary, the tectonic subsidence favoured the accommodation of more than 3000 m of marine, transitional, and alluvial sediments (santangelo et al., 2017, and references therein). during the first part of the late pleistocene, the filling of plain was helped by the onset of volcanic activity from different sources. at about 39 ka b.p. the huge eruption of campanian ignimbrite (ci) occurred (rolandi et al., 2003, and references therein) and uniformly covered the entire plain with a pyroclastic flow deposit tens of meters thick. tephra deposits interbedded with sediments provide important stratigraphic and geochronological markers. in the second part of the late pleistocene, the whole plain emerged due to the subsidence rate reduction and the contemporary last glacial regression. during the holocene, the plain underwent diffuse flooding in concomitance with the peak of the post-glacial transgression. the subsequent decrease of the sea level rise favoured coastal progradation and development of lagoon and swamp systems several kilometres inland from the present coastline (barra et al., 1996; amorosi et al., 2012). in this work, we present the results of an extensive and detailed stratigraphic analysis of the late pleistocene holocene infill of the volturno plain based on almost 700 well logs generally not exceeding 30 m of depth from the ground level. further, the geomorphological analysis of the quaternary elements of the landscape such as coastal features and foothill-plain connecting landforms has completed the frame of the recent evolution of the plain. the aim of this study is to define a detailed palaeoenvironmental and stratigraphic reconstruction after the ci eruption and the role of tectonic and eustatic forcing in the evolution of the coastal plain. 2. material and methods a subsurface lithostratigraphic dataset based on 680 wells drilled in the plain was integrated by geological cartography and field survey. detailed sedimentological analysis and facies interpretation were acquired from literature (e.g. romano et al., 1994; amorosi et al., 2012) and other unpublished data. all these data have constituted the core for the reconstruction of a quaternary stratigraphic succession. such a task has needed an effort to homogenize data from different sources by using log charts and their precise positioning in a gis. subsurface data have been used to realize geological crosssections and a map of roof of the ci by gis interpolation techniques. age determination for stratigraphic correlations is based on constraints of volcanic and marine deposits from literature (see references in results). https://doi.org/10.26382/aiqua.2018.aiquaconference 3. results the stratigraphic architecture of the late quaternary volturno plain infill has been reconstructed and seven lithostratigraphic units based on homogeneous sedimentological and palaeontological criteria have been individuated (fig. 1). hereinafter, they are briefly described from the younger to the older one, including their stratigraphic contacts with the adjacent units. stratigraphic and chronological constraints enable us to propose a general chronology and to attribute age intervals for each unit. unit 1 holocene deposits (12-0 ka) represent a complex and articulated sedimentary body progressively formed from sea to the land by four sub-units characterised by lateral transitional contacts: prodelta (u1a, clays and silts with euryhaline fossils), beach-dune ridge (u1b, well sorted sands with marine shells), lagoonal-swamp (u1c, clays with organic matter and freshwater gastropods) and alluvial (u1d, pedogenised clays and silts with sand lens) deposits. the u1 bottom is normally the u4 (ci), which also represents its lateral contact towards north and east. the pleistocene alluvial (u3) and pyroclastic (u2) deposits, represent a very discontinuous substrate for this unit. by integrating subsurface and literature (romano et al., 1994; barra et al., 1996; amorosi et al., 2012, sacchi et al., 2014) data, the u1 can be considered 24 fig. 1a) simplified geological map of the volturno plain area. legend: br: pre-quaternary bedrock; u4: campanian ignimbrite (late pleistocene); u2: depositional unit composed of both volcaniclastic sediments and pyroclastic units (giugliano ignimbrite and neapolitan yellow tuff, late pleistocene); u1d: alluvial deposits (holocene); u1c: back-dune ridge deposits (holocene); u1b: beach-dune ridge deposits (holocene); dt: slope deposits (late pleistocene – holocene). b) contour map of the campanian ignimbrite roof and inferred course of the palaeo-volturno river. c) geological cross-sections obtained from well logs (30x vertical exaggeration). corrado g. et al. 25 as holocene transgressive-regressive depositional complex. unit 2 pyroclastic flow and fall deposits and volcanoclastic sediments (23-12 ka b.p.) represented by the giugliano ignimbrite (gi; age 23-18 ka b.p., after rolandi et al., 2003) below and the neapolitan yellow tuff (nyt, ~12 ka b.p. in age, rolandi et al., 2003) above, deposited in subaerial conditions, and by their reworked deposits. the u2, bounded at the bottom by a palaeosol, mostly occurs in the southern sector of the volturno plain above the ci (u4). unit 3 late pleistocene alluvial plain deposits (29-39? ka b.p.) occur as channelled fills (gravels, sands passing upward to silts with peat intercalations) of fluvial palaeochannels incised in the u4. it is highly discontinuous and covered by u1 and u2 (radiometric age 37 ka b.p., after amorosi et al., 2012). unit 4 campanian ignimbrite (ci, 39 ka b.p.). pyroclastic deposits, laterally continuous, attributed to a highly explosive eruption of the phlegraean fields (rolandi et al., 2003 and references therein), covering the entire ancient plain with an articulate palaeotopography (fig. 1b). ci erosional roof shows progressively higher depths (about -35 m b.s.l.) towards the centre of the plain. unit 5 coastal-marine and transitional deposits with alluvial episodes (~?50-39 ka b.p.). yellowish and grey sands with molluscan shells, and clays with local peat lens represent the main lithology of this unit, which is the substrate of the ci and u3 at depth more than -35 m b.s.l. in central plain and above sea level in proximity of border relief. unit 6 pre-ci volcaniclastic deposits (~50-105 ka b.p.) erupted by roccamonfina and phlegraean fields and locally separated by thin palaeosols are included in this unit, which appears more discontinuous in the northern than in central and southern sectors of the plain. the u6 rests upon u7 by an erosional contact and is covered by the u4 and u5. its age is based on radiometric (~50-105 ka b.p.) and palaeoenvironmental constraints (romano et al., 1994; santangelo et al., 2010). unit 7 coastal-marine and transitional deposits (~105130 ka b.p.) are composed of fossiliferous clays and silts interbedded with yellow sands or fine gravels (u/ th dating ~126 ka b.p., after romano et al., 1994; >105 ka b.p., after santangelo et al. 2010). this unit is continuous and the deepest one, placed between 20 m a.s.l. in proximity of border relief and between 20 and -90 m b.s.l., on the left and right sides of the volturno river, respectively. these deposits cover lava bodies in the southern sector of the plain ascribed to the buried parete volcano. stratigraphic relationships of the above described units, partly represented in the geological cross-sections of figure 1c, suggest a complex late quaternary sedimentary evolution starting from the deposition of the ci, which represents the substratum of late pleistoceneholocene sediments. the subsurface channelized buried landforms in the ci substratum testifies the palaeovolturno river incision as a consequence of mis 2 sea level low stand. the facies analysis of holocene units indicates that the volturno river channel shifted from se to the present-day position (fig. 1b and fig. 1c, cross -section a). the deposition of the holocene unit 1 (coastal-lagoonal-swamp-alluvial sedimentary body) testifies the rapid marine transgression recorded by the progressive onlap of the beach-dune ridge sands on continental deposits. the maximum landward shift of transgressive sands can be estimated of about 3-4 km on average respect to the present-day position, so as the palaeo-position of the back-barrier environments is further inland. 4. discussion and conclusions the significant achievements of this research are: a) a better knowledge of distribution and evolution of the coastal-marine to continental palaeoenvironments of the volturno plain during the late quaternary; b) the reconstruction of base and roof of the campanian ignimbrite that – integrated by geomorphological analysis of the quaternary elements of the landscape has allowed upgrading the 3d shape of the volturno plain palaeomorphology before the deposition of late upper pleistocene holocene sediments. in fact, it is now possible to infer an asymmetrical shape of the ancient morphology of the plain with a steeper slope toward the north-west border (i.e. mt. massico morphostructural high) and the lack of coincidence between the present course of the volturno river and the main buried bedrock incision. based on these data, it is possible to affirm that the late quaternary evolution of the volturno plain has been mainly controlled by eustatic changes of sea level during which intense volcanic activity occurred. the rapid sea level rise after the last glacial maximum is testified by a backstepping depositional architecture of the holocene delta-coastal and lagoonal-swamp system directly on late pleistocene incised palaeo-volturno plain. the maximum ingression of the shoreline was about 3-4 km inland. starting from about 5 ka b.p., in response of the decreasing rate of sea level rise, a prominent coastal and delta system progradation and alluvial aggradation is documented from well and field data. however, taking into account also the subsidence data (aucelli et al., 2016; matano et al., 2018), late quaternary tectonics should be considered active to produce the asymmetry the ci roof as well as the lateral migration of the volturno river during this time interval. such a trend seems to continue in more recent times, as testified by the location of a thick alluvial succession (fig. 1c, cross-section a) south of the present-day main channel. references amorosi a., pacifico a., rossi v., ruberti d. (2012) late quaternary incision and deposition in an active volcanic setting: the volturno valley fill, southern italy. sedimentary geology, 242, 307-320. aucelli p.p.c., di paola g., incontri p., rizzo a., vilardo g., benassai g., buonocore b., pappone g. (2016) coastal inundation risk assessment due to subsidence and sea level rise in a mediterranean late quaternary evolution of the volturno coastal plain alluvial plain (volturno coastal plain, southern italy). estuarine coastal shelf science, 198, 597609. barra d., romano p., santo a., campaiola l., roca v., tuniz c. (1996) the versilian transgression in the volturno river plain (campania, southern italy): palaeoenvironmental history and chronological data. il quaternario, 9 (2), 445-458. matano f., sacchi m., vigliotti m., ruberti d. (2018) subsidence trends of volturno river coastal plain (northern campania, southern italy) inferred by sar interferometry data. geosciences, 8. doi: 10.3390/geosciences8010008. rolandi g., bellucci f., heizler m.t., belkin h.e., de vivo b. (2003) tectonic controls on the genesis of ignimbrites from the campania volcanic zone, southern italy. mineralogy and petrology, 79, 3-31. romano p., santo a., voltaggio m. (1994) l’evoluzione geomorfologica della pianura del f. volturno (campania) durante il tardo quaternario (pleistocene medio-superiore olocene). il quaternario, 7 (1), 41-56. sacchi, m., molisso, f., pacifico, a., vigliotti, m., sabbarese, c., ruberti, d. (2014) late-holocene to recent evolution of lake patria, south italy: an example of a coastal lagoon within a mediterranean delta system. globary and planetary change, 117, 9-27. santangelo, n., ciampo, g., di donato, v., esposito, p., petrosino, p., romano, p., russo ermolli, e., santo, a., toscano, f., villa, i. (2010) late quaternary buried lagoons in the northern campania plain (southern italy): evolution of a coastal system under the influence of volcano-tectonics and eustatism. bollettino della società geologica italiana, 129 (1), 156-175. santangelo n., romano p., ascione a., russo ermolli e. (2017) quaternary evolution of southern apennines coastal plains: a review. geologica carpathica, 68 (1), 43-56. 26 corrado g. et al. ms. received: may 15, 2018 final text received: may 21, 2018 sess 1_160211.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 holocene palaeo-geographical evolution of the sele river coastal plain (southern italy): new morpho-sedimentary data from the paestum area vincenzo amato1, pietro p.c. aucelli2, aldo cinque3, bruno d’argenio4, valentino di donato3, gerardo pappone2, paola petrosino3, carmen m. rosskopf1 & elda russo ermolli5 1dipartimento stat, università del molise, 2dipartimento disam, università parthenope, napoli 3dipartimento st, università federico ii, napoli 4iamc-cnr, napoli 4 dipartimento arbopave, università federico ii, napoli corresponding author: v. amato <vinamato@unina.it> abstract: amato v. et al., holocene palaeo-geographical evolution of the sele river coastal plain (southern italy): new morpho-sedimentary data from the paestum area. (it issn 0349-3356, 2011) the sele river plain is hosted in a graben along the tyrrhenian margin of the southern apennine chain and is formed of both displaced (early and middle pleistocene) and undisturbed (late pleistocene and holocene) sedimentary units. the strip that was accreted to the plain during the holocene high stand is characterized by beach-dune ridges whose sands interfinger –to the rearwith lagoonal and fluvio-palustrine deposits. the evolutionary trend was transgressive during the early holocene and progradational during the mid-late holocene. in this work, we present new data about the holocene evolution of the portion of the plain in front and immediately north of the poseidonia-paestum archaeological area, where the knowledge has been improved by five new cores and by many collected archaeo-bio-tephrostratigraphical data. in the first area (paestum area), due to a local rise of the ground (made of late pleistocene travertines) the holocene transgression formed cliffs, while the second area (laura area) was submerged. the tip of the travertine lobe was then cut by a sea cliff, whose correlative abrasion platform rests 7,5 m below the present s.l. the age of this stage can be inferred by the 14c dated mollusk remains (7.0 ky cal bp) of the beach deposits, found at the same depth in the laura cores. in mid holocene times the shoreline shifted seaward and a lagoonal environment – closed by the laura sand ridgewas established (fossa lupata area). age constraints for this stage are the agnano m. spina tephra (4.1 ky bp) and some archaeological remains of the vi cent. b.c. found within the upper part of the lagoonal clays. after this period, and mostly after the deposition of the 79 a.d. tephra, the shoreline shifted further seaward and an additional beach ridge formed, whereas the flat area of fossa lupata was rapidly aggraded and dried up. riassunto: amato v. et al., l’evoluzione paleogeografica olocenica della piana costiera del fiume sele (italia meridionale): nuovi dati morfo-sedimentari dall’area di paestum. (it issn 0349-3356, 2011) la piana del fiume sele, ospitata in un half-graben del margine tirrenico dell’appennino meridionale, è costituita da complessi fluvio-transizionali e costieri che appaiono sia dislocati (pleistocene inferiore e medio) che sostanzialmente indisturbati (pleistocene superiore ed olocene). i paleo-cordoni costieri del tirreniano (ois 5) decorrono a circa 3 km dalla costa attuale; una distanza pari all’ampiezza della fascia aggiuntasi alla piana durante l’olocene. tale fascia si caratterizza per la presenza di cordoni costieri le cui sabbie passano –verso montea depositi lagunari e fluvio palustri. come mostrano i dati di sottosuolo, la tendenza evolutiva generale è stata trasgressiva nella prima parte dell’olocene (con migrazione verso terra del sistema barriera-laguna) e progradazionale poi (d’argenio et al, 2010). in questo lavoro vengono presentati i principali risultati di una indagine sulla evoluzione olocenica del tratto di pianura antistante (area di paestum) ed immediatamente a n (area di laura) l’area archeologica di paestum (settore se della piana del sele). nell’area di paestum la fascia costiera olocenica, composta da più cordoni sabbiosi separati da piatte depressioni limotorbose, è meno ampia che nell’area di laura per la presenza di un dosso travertinoso che deve aver costituito un paleo-promontorio durante le fasi culminanti della trasgressione post-glaciale. al fine di ricostruire in dettaglio le locali morfo -dinamiche costiere oloceniche, sono stati eseguiti 5 nuovi carotaggi in settori strategici, individuati mediante una accurata revisione dei dati archeologici e stratigrafici preesistenti. sui livelli più significativi delle carote sono state eseguite analisi biostratigrafiche, palinologiche e tephrostratigrafiche supportate da indicazioni cronologiche fornite da datazioni 14c e da determinazioni archeologiche. i risultati conseguiti dimostrano in modo definitivo che le scarpatine rocciose che a tratti si riconoscono intorno al dosso travertinoso (ben evidente presso la porta marina di paestum) sono la parte ancora emergente di una falesia costiera che si modellò durante la trasgressione olocenica. circa la successiva fase di progradazione della linea di costa, i dati raccolti mostrano che essa avvenne con la formazione di un esteso cordone dunare (cordone di laura), posto circa 1 km più avanti della paleofalesia e recante alle spalle la depressione lagunare di fossa lupata. le analisi biostratigrafiche, supportate da reperti archeologici ascrivibili al vi sec a.c., dal del tephra di agnano m. spina (4.1 ka bp), e da datazioni assolute 14c, eseguite all’interno dei depositi limo-argillosi dei nuovi sondaggi, confermano la presenza di tale sistema morfo-sedimentario di barriera-laguna costiera per l’intervallo di tempo che va da circa 7.000 anni fa alla data di fondazione della città di poseidonia (540 a.c.). dopo questo periodo e prevalentemente dopo la deposizione dei prodotti distali dell’eruzione vesuviana del 79 d.c., la linea di costa entrò in una nuova fase di prevalente progradazione. nel contempo la depressione di fossa lupata conobbe una rapida aggrada 5 7 6 zione ad opera di depositi fluvio-palustri, riducendo fortemente il proprio areale, fino ad essere bonificata dall’uomo nel secolo scorso. key words: holocene, sea level rise, sele plain. parole chiave: olocene, risalita del livello del mare, piana sele 1. introduction the glacio-eustatic sea level rise occurred after the last glacial maximum (lgm) led to a worldwide flooding of coastal plains and controlled the evolution of marine embayments, fluvial mouths and rocky coasts.its significant deceleration in the midholocene often led to overcompensation by sediment supply and shoreline progradation. in the mediterranean area, progradation was more marked during the last 2.5 ky, when the impact of man on soils and vegetation covers increased the rates of erosion and, consequently, the solid discharge of rivers toward the coasts (amato, 2006 and references therein). this general evolutionary trend has been widely recognized by many multiproxy researches, including geomorphology, geology, palaeobiology and archaeology (pirazzoli, 1996 and references therein). similarly, it is known that the alluvial-coastal plain of the sele river was interested by the same morpho-sedimentary behavior during the holocene, with a transgressive trend during the early holocene and a progradational trend of shorelines starting from middle holocene (cinque, 2008 and references herein) the sele river plain is located along the tyrrhenian margin of the southern apennine chain and is formed of both displaced and undisturbed sedimentary units. the former are early to middle pleistocene in age, while the latter span from the last interglacial (ois 5) onwards. the fossil beach ridges of the late ois 5 run about 3 km inland from the present shoreline; a distance corresponding to the strip that was accreted to the plain during the holocene high stand. migrating also upward, the sandy barrier (including a dunal cover) reached up to 4-6 m above the present s.l. in the middle holocene (laura ridge; with shells dated between 5.3 and 3.6 ka; cinque, 2008 and references therein). the buildup of this ridge marked the beginning of a prevailingly progradational phase that included the construction of two other sand ridges (sterpina i and ii, dated to before 2.6 ky bp and around 2.0 ky bp respectively) and the filling of the back-barrier depression, initially with lagoonal pelites and then with palustrine deposits (cinque, 2008 and references therein). in the se portion of the sele plain, the late quaternary coastal evolution was affected by numerous generations of travertine deposits. recently, amato et al, (2009) have provided a detailed chronological reconstruction of the various stages of the paestum depositional system: it was active during the last interglacial (tyrrhenian) and the early holocene until about 5000 years ago, and in the historical period during the late-ancient and middle ages (v-ix century ad). in the coastal sector, in front of the archaeological area of poseidonia-paestum lippmann-provansal (1987) proposed, that a coastal lagoon had already established in the iron age (3.0 ky ago) while guy (1990), suggested that, during the classic period (2.5 ky ago), there was only a small lagoon (pond or artificially preserved and open to the sea). using geomorphological and integrated stratigraphic methods, we focused the researches on the holocene morpho-stratigraphy changes of this sector of the sele plain, in order to reconstruct the paleoenvironmental and landscape changes, and to decipher the local sea level rise history and horizontal shoreline changes. 2. new morpho-stratigraphical data the coastal strip in front of the archaeological area of paestum presents a very articulated landscape, consisting in an inner area situated at an altitude between 10 and 20 m a.s.l., some meters higher than the average level of the plain, that does not exceed 5 m a.s.l. such morphological high, slightly sloping to the sea, appears to be composed of travertine deposits, belonging to different depositional bodies (as previously described). these polyphasic depositional bodies, generated during the late quaternary, now form self-terraced bodies. landward, the hanging travertine bodies are connected to the piedmont belt of the capaccio hills and seaward to the coastal strip by a steep escarpment cut into travertine, whose remains are still visible at porta marina of paestum. this steep scarplet gently downgrades toward a depressed area (fossa lupata), situated at ca. 4 m a.s.l. behind a large sand dune ridge, which reaches ca. 6 m a.s.l. and is located about 1 km from porta marina. in the sector immediately northward, some units of the poliphased travertine lobe interfinger with barrierlagoonal systems of the hssls of ois 5. here, the holocene coastal strip is wider and, from its inner side down to the present shoreline, is constituted by a great flat depression area (2-3 m a.s.l.), connected with fossa lupata, and delimited seaward by two sandy barriers. in addition to the numerous archaeological and geoarchaeological data obtained from excavations, and to stratigraphic data derived by collected cores, five new cores (s2, s3, l1, l2 and l3) were drilled. s2 and s3 were taken, respectively, in the v. amato et al. 7 ms. received: testo ricevuto il area immediately west of the scarplet cut into the travertine of porta marina (5.5 m a.s.l.), and in the outer dune ridge, immediately behind the coastal road (2.5 m a.s.l.). l1, l2 and l3 were drilled in the area immediately north of the poseidonia-paestum archeological area, where the laura barrier-lagoon system crop out. the morpho-stratigraphic data, supported by biostratigraphic analyses, by tephra layer correlation, such as the 79 ad, the agnano monte spina (4.1 ky bp), the neapolitan yellow tuff (15ky bp), and the y3 tephra (30 ky bp), by 14c dated layers, by layers with archaeological remains, and referring the data to the known holocene morpho-sedimentary trends, allowed us to outline some important stages of the holocene palaeogeographical evolution of the se sector of the alluvial coastal plain. • the sea level low-stand of the lgm(20 ky bp) led to a strong progradation of the shoreline. therefore, the whole studied area was interested by fluvial-marshy sedimentation including the neapolitan yellow tuff and the y3 tephra. • the rapid sea level rise of the first part of the postglacial period led to a rapid submergence of the coastal plain. in the area of paestum, the transgressive trend has favored the formation of a cliff cut in travertine, now partly buried by travertine deposits of mostly medieval age. • as soon as the rate of the holocene sea level rise decreased, a rapid shoreline progradational trend started, and a barrier-lagoon coastal system formed. the 14c dating of mollusk remains from the beach deposits (7.0 ky cal bp), the presence of the agnano m. spina tephra (4.1 ky bp) and the archaeological remains of the vi cent b.c. into lagoonal deposits allowed us to hypothesize the presence of a barrier-lagoon coastal system during this period. • between the foundation of the greek-roman town of poseidonia-paestum (540 b.c.) and the 79 ad, the lagoonal area was interested by continental deposition (marsh); the shoreline prograded a few hundred meters and an additional sandy dune ridge formed seaward. • after the 79 ad and up to now, the shoreline progradational trend was emphasized and the flat depression area was interested by a strong aggradation of the ground level due to anthropogenic fills, reworked volcaniclastic deposits of the 79 ad and historical deposition of travertines. in conclusion, the archaeo-bio-tephra-chronostratigraphic data allowed us to assert that the holocene sea level rise reached -7,5 m a.s.l. at about 7.0 ky bp and -1.5 m a.s.l. at about 4.1 ky bp. these data, if compared with those about the holocene sea level rise in the mediterranean area, suggests that the paestum sector of the plain has been interested by a substantial tectonic stability. references amato v. (2006) la risposta di alcuni tipici sistemi morfodinamici della campania (italia meridionale) alle variazioni climatiche oloceniche. tesi di dottorato università “federico ii” di napoli 2006, www.fedoa.unina.it/406. 405 amato v., avagliano g., cinque a., cipriani m., di paola g., pontrandolfo a., rosskopf m. c. & santoriello a. (2009) geomorphology and geoarchaeology of the paestum area: modifications of the physical environment in historical times. mediterranee, 112, 129-135. cinque a. (2008) note illustrative del foglio geologico al 50.000 foce sele. servizio geologico nazionale d’argenio b., amato v., anzalone e.,. aucelli p.p.c, cesarano m., cinque a, da prato s., di paola g., ferraro l., pappone g., petrosino p., rosskopf c. m., russo ermolli e. (in press) holocene palaeo-geographical evolution of the sele river alluvial-coastal plain: new morphosedimentary data from poseidonia-paestum area. volume mare cnr, in stampa guy m. (1990) le rivage marittime et la «lagune» de poseidonia-paestum. in: albore livadie c. & widemann f. (eds.). pact, 25, 257-270. lippman-provansal m. (1987) l’apennin campanien meridional (italie). etude geomorphologique. these de doctorat d’etat. univ. aixmarseille. pirazzoli p.a. (1996) sea-level changes. the last 20.000 years. john wiley & sons, chinchester, inghilterra, 211. holocene palaeo-geographical evolution of the sele ... january 15, 2011 15 gennaio 2011 sess 1_160211.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 vertical mobility of the continental margin between latium and tuscany defined by means of eustatic minimum indicators francesco latino chiocci1,2, serena fraccascia1,3, davide scrocca2, francesco falese1 1university of rome “la sapienza”, rome, italy 2national research council, institute of environmental geology and geoengineering, rome, italy 3current affiliation: university of bremen, bremen, germany corresponding author: f. l. chiocci <francesco.chiocci@uniroma1.it> abstract: chiocci f. l. et al., vertical mobility of the continental margin between latium and tuscany, defined by means of eustatic minimum indicators (it issn 0349-3356, 2011) a number of earlier coastal tectonic studies used marine terraces and their correlation with the eustatic curve in order to define vertical movements (uplift or subsidence) of coastal areas. analogamente, in this study the paleo-shelfbreak formed at the sea level lowstand of mis 12 (450 kyr) and two submerged terraced related to it were characterized by analyzing high resolution reflection seismic profiles. their current depth below the present day sea level were measured and compared to the sea level of mis 12, as know from literature. these features are currently located at different depths along the continental margin, due to the interaction between load subsidence of the margin (at a rate of 0.20 mm yr-1 in the last 450 kyr) and tectonic uplift (at a rate up to 0.20-0.24 mm yr-1, varying along the margin). riassunto. chiocci f. l. et al., mobilità verticale del margine continentale al confine tra lazio e toscana, definite attraverso indicatori di minimo eustatico (it issn 0349-3356, 2011) molti studi di tettonica costiera utilizzano i terrazzi marini e la loro correlazione con la curva eustatica per definire le variazioni verticali (sollevamento o subsidenza) delle aree costiere. analogamente, in questo studio il paleociglio di scarpata formatosi in corrispondenza del basso stazionamento del livello marino del mis 12 (450 ka) e due terrazzi sommersi ad esso correlati sono stati caratterizzati attraverso l’analisi di profili di sismica a riflessione ad alta risoluzione e le loro profondità al di sotto del livello del mare attuale sono state confrontate con il livello marino del mis 12 noto in letteratura. tali elementi si trovano attualmente a profondità variabili lungo il margine continentale, a causa dell’interazione di subsidenza del margine, con un tasso di circa 0.20 mm a-1 negli ultimi 450 ka, e sollevamento tettonico, con un tasso variabile lungo il margine e fino a 0.20-0.24 mm a-1. key words: neotectonics, last glacial maximum, seismic stratigrafy parole chiave: neotettonica, ultimo pleniglaciale, stratigrafia sismica global sea level has changed several times during the geological history. during quaternary, glacio-eustatic sea level changes have been characterized by high amplitude and high frequency (~100 m in 100 kyr) and by a nearly constant range between 120 m depth and the present sea level. in the course of these oscillations, at still-stand stages, terrace-shaped depositional bodies may be formed below the wave base level, resulting from sediment remobilization due to littoral erosion during high-energy storm events (chiocci & orlando, 1996; chiocci et al., 2004). the highstand features are the so-called marine terraces (at the present time occurring along the coasts), whilst lowstand features are wedged-bodies addressed as submerged or lowstand terraces that currently can be found at shelf breaks or, less frequently, in continental shelves (cf. fig. 2 in chiocci et al., 2004). if deposits building up a continental margin are preserved, a sharp change in slope in stratigraphic units can be usually recognised in seismic profiles, which is commonly interpreted as paleo-shelfbreak. as the current shelfbreak is thought to be related to the minimum sea level reached during the last eustatic cycle, paleo-shelfbreaks can be assumed as paleosea level indicators at glacial maximum stages. a paleoshelfbreak usually matches a limit between an erosional unconformity landward and a correlative conformity basinward, which can be used to define the position of eustatic minimum. when sea level changes occur, the aforementioned features may be preserved at their original position, thus becoming sea level proxies. when a coastal region is affected by tectonics, however, the position of marine and submerged terraces can be shifted either upward or downward, if respectively tectonic uplift or subsidence occurs. on land and onshore, the use of marine terraces as proxy of sea level highstand is a well established methodology, with worldwide applications in coastal tectonic studies, in order to assess the vertical mobility of a continental margin (amongst many others, campbell, 1986; marquardt et al., 2004; litchfield et al., 2010). for instance, when dating is not possible, a constant uplift rate is commonly assumed and different terrace orders are correlated to different highstand events from lower younger terraces to higher older ones (e.g. mcneill & collier, 2004). offshore, however, submerged terraces are not as much exploited. high resolution reflection seismics allows a very good depiction of the shallow features and overall stratigraphic architecture of a continental margin, providing a much higher resolution and spatial continuity than geological surveys on land. nevertheless, to the knowledge of the authors, earlier studies dealing with submerged terraces focused on the reconstruction of local sea level lowstands (e.g. shipp et al., 1991, lericolais et al., 2009), while only lebesbye & vorren (1996) investigated these features in order to assess vertical movements due to tectonic subsidence in the barents sea. 26 28 27 here, the paleo-shelfbreak and two submerged terraces created during a middle-upper pleistocene glacial maximum were characterized, in order to define the vertical motions of the continental margin between latium and tuscany. in fact, seismic and sequence stratigraphy, integrated with core ground-truthing and biostratigraphic analysis, allowed to date depositional features related to sea level lowstand of different eustatic cycles. consequently, it was possible to reconstruct uplift/subsidence distribution along the margin. along the continental margin between latium and tuscany (central eastern tyrrhenian sea), about 3000 km of high and very resolution reflection seismic profiles, acquired during the last decades, were analyzed and interpreted by applying principles of seismic and sequence stratigraphy. six seismic units were defined, related to the last ~500 kyr and interpreted as 4th-order depositional sequences. sequence boundaries can be either erosional unconformities or correlative conformities related to unconformities eroded by continental shelf emersion during sea level lowstands. biostratigraphic constraints provided by borehole-logs and gravity cores and correlation with the eustatic curve allowed to establish the chronostratigraphy of sequence boundaries (chiocci, 2000). each sequence boundary was named referring to the lowstand marine isotope stage (mis) when they were thought to be formed. thus, the depositional sequences described in the area are delimited, from the oldest to the most recent one, by the surfaces u14 (540 kyr), u12 (450 kyr), u10 (350 kyr), u8 (260 kyr), u6 (140 kyr) and u2 (20 kyr). landwards of paleo -shelfbreak, sequence boundaries are regional highamplitude reflectors, which erosionally truncate underlying reflectors; basinward, they are high-amplitude highcontinuity reflectors conformably lying on underlying strata. load subsidence usually affecting passive continental margins allowed depositional sequences to be partially preserved even in the inner continental shelf, despite the nearly constant oscillation range of sea level during quaternary. however, in the study area, the sequence boundaries of mis 10, 8 and 6 lack unconformities and show only correlative conformities, while more ancient sequences (e.g. resting on u14 and u12) show both unconformities and correlative conformities, like the u2, related to the last glacial maximum (chiocci, 2000). two buried wedge-bodies were identified in the offshore between tarquinia and ladispoli, the first one ~18 km long and the second one ~27 km long (fig.). they were interpreted as submerged terraces owing to the glacioeustatic minimum of mis 12. the paleo-shelfbreak and submerged terraces of mis 12 were analyzed and their characters and depth were defined along the studied margin. based on the assumption that both features were generated at the same sub-sea level depth, they were considered as paleo-sea level indicators. the depth of paleo-shelfbreak and submerged terraces (inner edge) below the current sea level gradually changes along the margin, rising from an average of 220 m in the northern sector (mt. argentario) to 131 m offshore civitavecchia and ladispoli, then decreasing to 202 m athwart tiber river mouth and rising again to 166 m offshore lido di ostia (fig.). the northern sector of the study area, where metamorphic bedrock arises, was considered to be stable, so that current depth of mis 12 paleo-sea level indicators is only affected by subsidence. therefore all paleo-sea level indicators found at lower depth are supposed to have been uplifted. assuming that during mis 12 the sea level was about 130 m below the current sea level (pisias et al., 1990, cited by caputo, 2007), the overall subsidence of the outer continental shelf was estimated in about 0.20 mm yr-1 in the last 450 kyr. considerations about the differential preservation of depositional sequences in the study area suggests that the regional uplift occurring in the continental margin began between 450 and 350 kyr, when the surfaces u12 and u10 developed, respectively. the depth of mis12 paleoshelfbreak and related depositional terrace gradually decreases south-eastward, moving along the margin, implying a relative uplift of about 89 m with respect to expected depth of 220 m (fig. 1). taking the latter as a reference value, a differential uplift rate up to 0.20 or 0.25 mm yr-1 can be estimated for the civitavecchia-ladispoli offshore, respectively in the last 450 kyr or 350 kyr. in agreement with this result, the lack of unconformity of mis 6, 8 and 10 and the preservation only in outer shelf of the older ones, indicates that uplift must have surmounted the regional subsidence that characterizes the tyrrhenian margin. the minimum depth observed offshore civitavecchialadispoli matches with the maximum regional uplift recognized along the coast of latium by on land studies, based on the altitude of uplifted marine terraces related to mis 9, 7 and 5e (340, 250 and 125 kyr respectively) (de rita et al., 2002; nisi et al., 2003; ferranti et al., 2006). studies of coastal terraces reveal that uplift rate increases southeastward and started between 400 and 200 kyr; both this fact point out that uplift may be due to the volcanic activity that affected the margin since 500 kyr (e.g. cavinato et al., 1992; karner et al., 2001; giordano et al., 2003; ferranti et al., 2006). the result of our analysis and their comparison with data derived from the present day elevation of marine terraces suggest that the areal distribution of this uplift is not homogeneous along the continental margin. the overall licture highlight the likely presence of a bulge likely centered on the sabatini mounts volcanic complex, perfectly aligned with the main measured peak. however, seismostratigraphic analysis made by bartole (1995) highlighted the presence of a magmatic intrusion beneath the shelf in this area, independent from the volcanic complexes on land, which may be responsible for the observed uplift. the secondary peak in the mis 12 paleo-sea level elevation (centered to lido di ostia) can be attributed to a local uplift caused by three anticlines whose end of activity is unknown, because the erosion unconformity formed during the last glacial sea-level lowstand eroded most of the depositional sequences more recent than 450 kyr ago. very high-resolution seismic reflection data in this area reveal deformation evidences at least up to 350 kyr. vertical mobility of the continental margin between ... 28 ms. received: testo ricevuto il references bartole r. (1995) the north tyrrhenian northern apennines postcollisional system constraints for a geodynamic model. terra nova, 7, 7-30. campbell j.f. (1986) subsidence rates for the southeastern hawaiian-islands determined from submerged terraces. geomarine letters, 6, 139-146. caputo r. (2007) sea-level curves: perplexities of an end-user in morphotectonic applications. global and planetary change, 57, 417-423. cavinato g.p., de rita d., milli s., & zarlenga f. (1992) correlazione tra i principali eventi tettonici, sedimentari, vulcanici ed eustatici che hanno interessato l'entroterra (conche appenniniche) e il margine costiero tirrenico laziale durante il pliocene superiore ed il pleistocene. studi geologici camerti, 1992/1, 109-114. chiocci f.l. (2000) depositional response to quaternary fourthorder sea-level fluctuations on the latium margin (tyrrhenian sea, italy). in hunt, d., and gawthorpe, r.l., eds., sedimentary responses to forced regressions: special publications: london, geological society, 271-289. chiocci f.l., d'angelo s., romagnoli c., ricci lucchi f., & group s.w. (2004) submerged depositional terraces along the italian coasts conclusion. in chiocci f.l., d'angelo s., & romagnoli c., eds., atlas of submerged depositional terraces along the italian coasts: memorie descrittive della carta geologica d'italia: roma, apat dipartimento difesa del suolo, servizio geologico d'italia, 111-116. chiocci f.l. & orlando l. (1996) lowstand terraces on tyrrhenian sea steep continental slopes. marine geology, 134, 127-143. de rita d. et al. (2002) volcaniclastic sedimentation in coastal environments: the interplay between volcanism and quaternary sea level changes (central italy): quaternary international, 95-6, 141-154. ferranti l. et al. (2006) markers of the last interglacial sealevel high stand along the coast of italy. tectonic implications: quaternary international, 145, 30-54. giordano g. et al. (2003) the sedimentation along the roman coast between middle and upper pleistocene: the interplay of eustatism, tectonics and volcanism new data and review. il quaternario, 16, 121-129. karner d.b., marra f., florindo f. & boschi e. (2001) pulsed uplift estimated from terrace elevations in the coast of rome: evidence for a new phase of volcanic activity?. earth and planetary science letters, 188, 135-148. lebesbye e., & vorren t.o. (1996) submerged terraces in the southwestern barents sea: origin and implications for the late cenozoic geological history. marine geology, 130, 265-280. lericolais, g., bulois, c., gillet, h., & guichard, f. (2009) high frequency sea level fluctuations recorded in the black sea since the lgm: global and planetary change, 66, 65-75. litchfield n., wilson, k., berryman k. & wallace l. (2010) coastal uplift mechanisms at pakarae river mouth: constraints from a combined holocene fluvial and marine terrace dataset. marine geology, 270, 72-83. marquardt c., lavenu a., ortlieb l., godoy e. & comte d. (2004) coastal neotectonics in southern central andes: uplift and deformation of marine terraces in northern chile (27° s). tectonophysics, 394, 193-219. mcneill l.c. & collier r.e.l. (2004) uplift and slip rates of the eastern eliki fault segment, gulf of corinth, greece, inferred from holocene and pleistocene terraces: journal of the geological society, 161, 81-92. nisi m.f., antonioli f., pra g.d., leon g. & silenzi s. (2003) coastal deformation between the versilia and the garigliano plains (italy) since the last interglacial stage. journal of quaternary science, 18, 709-721. pisias n.g., mix a.c. & zahn r. (1990) nonlinear response in the global climate system: evidence from benthic oxygen isotopic record in core rc13-110. paleoceanography, 5, 147– 160. shipp r.c., belknap d.f. & kelley j.t. (1991) seismicstratigraphic and geomorphic evidence for a postglacial sealevel lowstand in the northern gulf of maine: journal of coastal research, 7, 341-364. fig. 1, study area and data location. the plot shows the elevation of mis 12 paleo-sea level indicators below current sea level along the transect a-h. area di studio. il diagramma mostra le quote attuali degli indicatori del paleolivello del mare durante il mis 12 lungo il profilo a-h. f.l. chiocci et al. january 15, 2011 15 gennaio 2011 amq29(2) 3 negri 137-142nag.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 29 (2), 2016, 137 142 the fronte candidate section for the upper pleistocene gssp: a short report alessandra negri 1, fabio florindo 2, pontus c. lurcock 2, stefano marabini 3, caterina morigi 4, giuseppe mastronuzzi 5, costantino vetrone 4, gian battista vai 5 1 dipartimento di scienze della vita e dell'ambiente, università politecnica delle marche, ancona, italy 2 ingv, roma, italy 3 dipartimento di scienze biologiche, geologiche e ambientali, università di bologna, bologna, italy 4 dipartimento di scienze della terra, università di pisa, pisa, italy 5 dipartimento di scienze della terra e geoambientali, università di bari, bari, italy corresponding author: a. negri <a.negri@univpm.it> abstract: we report new data regarding the environmental history of the taranto area since mis 11, which possibly led to the peculiar sediment preservation characterizing the fronte section. this section is a very promising candidate for the upper pleistocene gssp. some preliminary results achieved after the multiple core drilling at the fronte locality (taranto, italy) are reported as well. keywords: upper pleistocene, gssp, morphostratigraphic reconstruction, paleomagnetism, taranto 1. introduction the taranto area is located in the apulian platform (southern italy) where a near 6 km-thick succession of mesozoic neritic limestones (calcari delle murge) is unconformably overlain by the marine pliocene to pleistocene gravina calcarenite, the marine pliocene to middle pleistocene subapennine clay or blue clay (argille subappennine), and marine terrace deposits of middle to late pleistocene age. the marine terrace deposits generally show a characteristic unconformable contact with the underlying blue clay. among them, those showing the presence of rhodalgal biocalcarenites containing warm-water “senegalese” fauna (with the most known persististrombus latus), and reefal buildups bio-constructed by cladocora caespitosa (hearty & dai pra, 1992; belluomini et al., 2002; peirano et al., 2009 and references therein) date to the last interglacial period. in particular, the outcrop at the fronte locality has attracted the curiosity of several authors (dai pra & stearns, 1977; belluomini et al., 2002), providing excellent exposure of an exceptionally preserved thick fine -grained sedimentary succession lying above the calcarenites and reefal build-ups pertaining to the mis 5.e, studied in detail by antonioli et al., 2008, amorosi et al., 2014 and negri et al., 2015. the outcrop is located about 7 km east of taranto (fig. 1), along the coastal cliff surrounding the mar piccolo (fig. 1) close to the 65° deposito territoriale of the aeronautica militare, taranto, italy (40°28’32.57’’ n, 17° 18’48.07’’ e). the section is easily accessible by land and sea, because of the proximity to the harbour, and the km-sized outcrop guarantees easy sampling for comparison. moreover, the conservation of the outcrop site is assured by a protocol under formalization between bari and taranto universities and the administrafig. 1 location map of the fronte section taranto, italy (red dot). work presented during the aiqua scientific conferences "waiting for the nagoya inqua xix congress", held in florence, june 18 19, 2015 138 negri a. et al. tion of the italian air force, owner of the fronte site. finally, this site has been appointed as special geosite natural monument cgp432 by the puglia region administration who recognized its geological importance (mastronuzzi et al., 2015). the stratigraphic section consists of 5 lithologic units described in amorosi et al. (2014) and negri et al. (2015) (fig. 2). according to negri et al. (2015), above a regional unconformity the mis 5.e, these deposits are continuously sedimented showing an overall deepeningupward trend, from nearshore to inner-shelf (cladocorarich) and then middle to outer-shelf deposits. above the cladocora-rich units, the open-marine clays include the maximum flooding zone and show a continuous succession of marly clays, 6.25 m thick (unit 4) in which stable isotopic, foraminiferal and palynological data, coupled with the u-th dates, indicate that the whole mis 5.e plateau (sensu shackleton et al., 2003), up to the onset of the following sea-level fall, occurs in this section. based on our previous studies, the present paper aims to 1) attempt the reconstruction of the evolution which led to the preservation of the fronte cliff and its peculiar sedimentary succession 2) provide a short report regarding the activities ongoing on the fronte site, where a composite core was drilled in february 2015, on top of the outcropping section. 2. inferred evolution of the taranto area since mis 11 an attempt to reconstruct the geological history leading to the preservation of a fine sedimentary succession above the calcarenites is based on the presence of two quasi-flat surfaces whose inner margins occur refig. 2 the fronte section stratigraphic log. 139 the fronte candidate section for the upper pleistocene gssp: ............ spectively at 28-35 and 35-55 m above sea level, as reported by dai pra & stearns, 1977. they reported the higher and more landward as older than 300 ka (based on four u-th dates yielding ages ranging from 250 to 350 ka). such an age is consistent with marine isotope stage (mis) 9 or 11, the last being the longest (423,000362,000 ka) and warmest interglacial of the entire quaternary period, attaining the highest-known sea-level so far (roberts et al., 2012). these features therefore suggest a low uplift rate at least during the last 125 ka, but possibly extended up to the last 400 ka, which is consistent with the hypothesis of a large bay (”the taranto paleobay”) submerging a wide area around the present mar grande and mar piccolo during the last two major highstand peaks (mis 5.e and mis 11), (fig. 3 based on the original drawings of dai pra & stearns, 1977). in addition, the possibly mis 11 to mis 7 aged “panchina” (calcarenites) terraces outcropping around the locality masseria san pietro (c in fig. 3) were probably formed by alternate processes of marine abrasion and fluvial incision for some tens of meters during the quite long and relatively stable mis 11 or mis 9 to mis 5 time interval. the ensuing steep-walled taranto palaeovalley was carved mostly through the blue clay (argille azzurre) substratum which developed mainly under control of a regional tectonic-related karst springs net, which is still active (fonte galeso). the rapid rise of mis 5.e sea level submerged not only the mis 6 emerged taranto palaeovalley but probably also most of the masseria s. pietro mis 11 terrace. in this view, depressed areas, such as salina grande (fig. 3), accommodated a mainly pelitic sedimentation (similar to unit 4 at the fronte section in amorosi et al., 2014 and negri et al., 2015) whereas the most elevated areas were places of nearly continuous carbonate sedimentation (panchina with persististrombus latus and small colonies of cladocora caespitosa). this morphostratigraphic interpretation permits us to attribute the fronte cliff outcrop to the infill of mis 5 sediment on the southernmost side of the “taranto palefig. 3 geologic geomorphologic map showing interpretative reconstruction of the mis 5 (d) and mis 11? (c) marine terraces and related coastlines in the taranto area (modified after dai pra & stearns, 1977; mastronuzzi, 2001; belluomini et al., 2002, amorosi et al., 2014). a, pre-middle pleistocene calcareous substratum; b, lower to middle pleistocene pelagic sediments (blue clay); c, middle pleistocene calcareous marine deposits (mis 11?); d, upper pleistocene marine deposits (mis 5); e, holocene alluvial and beach deposits; f, reclaimed areas (19th and 20th centuries); g, black dots: outcrops with “senegalese” fauna. numbers indicate elevation above sea level. note that according to dai pra & stearns (1977), the boundary between a and c is a paleo coastline older than 300 ka. ovalley”, depressed enough to be submerged early during termination ii, and protected seaward by sandy shoals and islands. in this way, above the unconformity bounding the upper part of the blue clay (argille subappennine fm), the continuous coastal to marine succession (including most of mis 5.e) was preserved from the subsequent low-stand dissection and erosion. after mis 5, sea-level drop caused the palaeovalley’s distal segment to be reincised during mis 4 to mis 2 and later filled by the holocene clayey deposits cored in the mar piccolo basin floor, creating the present morphology. based on the detailed section reported in dai pra & stearns (1977) and belluomini et al. (2002) we infer that only a few areas (the fronte locality and the salina grande segment) became morphologically fossilized because they were protected from retrogressive erosion by the hard panchina beds and, probably, some differential vertical movements. but this inferred evolution shows that the combination of low uplift rate with dissected palaeomorphology provides, in this case, a particularly favourable host for sedimentation articulated in different facies and variable thicknesses, resulting in a unique candidate area for the upper pleistocene gssp. 3. new cores and investigations in this view of great potential to host a gssp, a further improvement in the study of the section started from the preliminary paleomagnetic results published by negri et al. (2015), suggesting the suitability of sediments for a complete paleomagnetic study. this idea led us to drill multiple cores at the fronte locality. the drilling was done on february 2015 at the top of the cliff 140 negri a. et al. fig. 4 the mis 5 “taranto palaeobay” (blue area: mis 5.e ionian sea; yellow area: mis 11 or mis9 + marine terrace; orange area: emerged pre-mis 11 local substrate) (base map after dai pra & stearns, 1977). fig. 5 the fronte cores stratigraphic logs. 141 the fronte candidate section for the upper pleistocene gssp: ............ ms. received: december 15, 2015 final text received: may 5, 2016 where the section crops out, and yielded two cores (fig. 5), showing the same lithological succession sampled in the field. we then sampled the cores (red bars in fig. 5) using u-channels (1 m in length) and standard ~8 cm3 plastic cubes made up of non-magnetic material, and investigated the geomagnetic palaeosecular variation and relative palaeointensity recorded in these sediments. stepwise alternating-field treatment resulted in good demagnetization behaviour, with most samples showing a clear, major origin-directed magnetization component. the average inclination of around 57° is close to the geocentric axial dipole inclination of 60° for the sampling site, with the difference attributable to typical inclination shallowing effects. the record contains several brief excursions of shallowed inclination. the most significant of these reaches inclinations of below 10°, and we tentatively correlate it with the blake event. relative palaeointensity exhibits a similarly dynamic behaviour across this interval. integration of our palaeomagnetic record with ongoing biostratigraphic work, and with other regional palaeomagnetic data, will provide a more thorough characterization of late pleistocene palaeosecular variation in southern europe. 4. conclusion in conclusion, we are intensifying the study of this section, but also we plan to go well beyond. in fact, although this section has to date received considerable attention from a multidisciplinary team, with basic information now available in the literature, further comprehensive activity is required to evaluate its correlation with coeval continuous marine successions, thus permitting comparison with north-western european continental records. this work is a necessary prerequisite for any proposal for this section as a gssp candidate. we intend to fill the current gap in the correlation of the fronte section with coeval marine mediterranean successions and with the continental north western europe sections, using all the available proxies, thereby building a reliable framework for the detection of the upper pleistocene gssp. references amorosi a., antonioli f., bertini a., marabini s., mastronuzzi g., montagna p., negri, a. rossi v., scarponi d., taviani m., angeletti l., piva a., vai g. b. (2014) the middle-upper pleistocene fronte section (taranto, italy): an exceptionally preserved marine record of the last interglacial global and planetary change, 119, 23-38. antonioli f., deino a., ferranti l., keller j., marabini s., mastronuzzi g., negri a., piva a., vai g.b. vigliotti l. (2008) lo studio della sezione “il fronte” per la definizione del piano tarentiano (puglia, italy). il quaternario italian journal of quaternary sciences, 21(1a), 35-38. belluomini g., caldara m., casini c., cerasoli m., manfra l., mastronuzzi g., palmentola g., sanso' p., tuccimei p., vesica p.l. (2002) the age of late pleistocene shorelines and tectonic activity of taranto area, southern italy. quaternary science reviews, 21, 525-547. dai pra g., stearns c.e. (1977) sul tirreniano di taranto. datazioni su coralli con il metodo del 230th/234u. geologica romana, 16, 231-242. hearty p.j., dai pra g. (1992) the age and stratigraphy of middle pleistocene and younger deposits along the gulf of taranto (southeast italy). journal of coastal research 8 (4), 82-105. mastronuzzi g., valletta s., damiani a., fiore a., francescangeli r., giandonato p.b., iurilli v., sabato l. (eds) (2015) geositi della puglia. sagraf, capurso, bari, 394 pp. mastronuzzi g. (2001) indagine conoscitiva geologico ambientale del sistema del mar piccolo (taranto): caratteri evoluzione, dinamica, valore e pericolosità di un potenziale geosito. in: atelier taranto, comune di taranto. progetto posidonia, unione europea, commissione europea dg xvi, art. 10 fesr, azioni innovatrici, programma terra, progetto n.55 posidonia, comune di taranto, vii settore governo del territorio, cd rom. http//www.comune.taranto.it. negri a., amorosi a., antonioli f., bertini a., florindo f., lurcock p.c., marabini s., mastronuzzi g., regattieri e., rossi v., scarponi d., taviani m., zanchetta g., vai g.b. (2015) a potential global boundary stratotype section and point (gssp) for the tarentian stage, upper pleistocene, from the taranto area (italy): results and future perspectives. quaternary international, 383, 145-157. doi: 10.1016/j.quaint.2014.08.057 peirano a., kružić p., mastronuzzi g. (2009) growth of mediterranean reef of cladocora caespitosa (l.) in the late quaternary and climate inferences. facies 55, 325-333. roberts d. l., karkanas p., jacobs z., marean c. w., roberts r. (2012) melting ice sheets 400,000 yr ago raised sea level by 13 m: past analogue for future trends. earth and planetary science letters, 357-358, 226-237. shackleton n. j., sánchez-goñi m. f., pailler d., lancelot y. 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/pdfxoutputintentprofileselector /documentcmyk /preserveediting true /untaggedcmykhandling /leaveuntagged /untaggedrgbhandling /usedocumentprofile /usedocumentbleed false >> ] >> setdistillerparams << /hwresolution [2400 2400] /pagesize [612.000 792.000] >> setpagedevice amq abs chiellini et al palcom 121-124.pub available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 121 124 palaeo-environmental reconstruction of the mercure basin (basilicata region) during mis 13, through a multi-proxy analysis of lacustrine sediments matteo chiellini 1, giovanni zanchetta 1, eleonora regattieri 1, biagio giaccio 2, natale perchiazzi 1, chiara boschi 3 1 dipartimento di scienze della terra, university of pisa, pisa, italy 2 igag-cnr, roma, italy 3 igg-cnr, pisa, italy corresponding author: m. chiellini <m.chiello89@gmail.com> abstract: the main purpose of this work is to make a first evaluation of the potential of the carbonate lacustrine sediment of the mercure basin (basilicata region), to preserve palaeoclimatic information during the middle pleistocene. for this purpose a multi-proxy analysis of the lacustrine sediments from a selected section of the basin was undertaken. the selected section contains several tephra layers, which constrains the timing of deposition to mis 13. stable isotopes (oxygen and carbon) and element content were tentatively interpreted as linked to climatic changes giving interesting results for this poorly studied interval. keywords: multi-proxy, stable isotopes, palaeoenvironment, palaeoclimate, mediterranean 1. introduction apennine tectonic basins are fundamental archives for the reconstruction of past climate conditions (e.g. giaccio et al., 2015). mercure basin is currently a large river basin, which extends from the s-w basilicata to the calabria boundary (fig. 1). during the middle pleistocene, the mercure basin was entirely occupied by a lake (schiattarella et al., 1994; robustelli et al., 2014). the presence of some tephra layers and their direct dating and correlation with known eruptions allowed a precise chronological definition of part of the lacustrine succession (giaccio et al., 2014). this indicates that lacustrine succession deposited during marine isotope stage (mis) 13, ca. 533-478 ka, an interval still poorly studied in the mediterranean area. 2. materials and methods in this study, the composite section of s. ciriaco (between the locations of rotonda and viggianello) was sampled, at a constant resolution of 10 cm, for a total of 21 m. in the sampled section, there are the volcanic tephra layers of different origins (sc5, sc4, sc3, sc2 and sc1) described by giaccio et al. (2014). isotopic analyses (δ13c and δ18o) were performed on all the samples using a gas bench ii (thermo scientific) coupled with an irms delta xp, whereas carbonate content was measured at resolution of 20 cm using de astis’ calcimeter. x-ray fluorescence analyses were made through spectrometer niton xl3t goldd + xrf. finally, x-ray diffraction analyses were made using a brucker d2 phaser diffractometer. 3. results and discussion the analysed composite section is made of 5 subsections. correlation among subsections was allowed during the sediment sampling thanks to the volcanic tephra layers and stratimetric criteria (fig. 2a). samples of conglomerate was also sampled to compare isotopic data between lacustrine and potential clastic component. the chronology of the succession was based on 40ar/39ar dating on sc1 and sc5 tephras, which turn out to be between, respectively, 494 ±11 ka and 517 ±3 ka (giaccio et al., 2014), as well as on the correlation of the sc5 tephra level with the same level found in the lacustrine basin of ohrid, macedonia (francke et al., 2016). further tuning points were obtained from comparisons with the ohrid record (francke et al., 2016). from the analysis, it emerges that the content of caco3 is variable: it oscillates between a minimum of 64% and a maximum of 97% (fig. 3), with average values of ca. 83%. the isotopic record shows that δ18o and δ13c records have different trends. the δ18o curve shows to be roughly consistent with the percentage variation of caco3 (fig. 3). in the δ18o record, three intervals can be distinguished on the basis of the different values with respect to the average value of -4.35‰. the first interval, from 545 ka to 520 ka, exhibits more negative values than the average; the second interval, from 520 ka to about 505 ka. is characterized by less negative values than the average; the third interval, from 505 ka to 493 ka, shows similar values to the average (fig. 3). the δ13c curve shows less congruent trend with the caco3 record; it can be divided into two parts with respect to the average value of -0.13‰: the first part has positive values and the second has values significantly more negahttps://doi.org/10.26382/aiqua.2018.aiquaconference tive than the average value. results from the x-ray fluorescence (xrf) made on fifty-nine samples were expressed as concentration curves for each element. the curves of ca and sr show quite congruent trends with the percentage variation of caco3. on the contrary, the curves of k, ti, sr, rb and zr show poor congruent trends compared to the others. x-ray diffraction (xrd) points out that the main mineralogical phase is calcite, which is associated to less represented quartz, aragonite and muscovite. aragonite is possibly related to the presence of abundant freshwater shell remains. 4. discussion and conclusion according to leng & marshall (2004), the content of caco3 can be interpreted as an indicator of primary productivity within the lake. the variation of δ18o is considered as an indicator of the water recharge/ evaporation ratio and of the amount effect in precipitation in the basin catchment, as demonstrated for other italian lacustrine successions (giaccio et al., 2015; regattieri et al., 2015, 2016). variation of δ13c, despite being more complex to interpret, is considered indicator of photosynthetic activity within the lake as well as internal processes such as recycling of organic matter and the equilibration of the lake water with the atmospheric co2 (leng & marshall, 2004). the variation of the ca concentration was correlated to the caco3 content and interpreted as an indicator of the quantity of bioinduced calcite. the variations of k, ti, si, rb and zr were considered as indicator of clastic input within the lake. during the interval from 545 ka to 520 ka, the instability of caco3 content and the progressive decrease of δ13c suggest a progressive decrease of primary produc 122 chiellini m. et al. fig. 1 (a) location of the mercure basin with respect to the main volcanic centers of central and southern italy (b) geological map of the mercure basin (modified from giaccio et al., 2014). 123 palaeo-environmental reconstruction of the mercure basin during mis 13 fig. 2 (a) representative stratigraphic and lithological sketch of the s. ciriaco section containing tephra layers. (b) fieldwork of samples collection at the s. ciriaco section, during august 2016. fig. 3 variation trend of the δ18o, of the δ13c, of the % caco3 and the elements ca e ti, with highlighted the three distinct phases expressed consistently by all the proxies. tivity and photosynthetic activity. in this interval, a reduction of the amount of precipitation and an increase of the detrital contribution within the lake is suggested by the increasing to less negative values of δ18o and increasing of the amount of k, rb, zr, si and ti. in the phase between 520 ka and 505 ka, more negative caco3 and δ13c values point to a minimum in the primary productivity and a maximum reduction of photosynthetic activity; minimum values of δ18o and increase of k, rb, zr, si and ti in this interval suggest decreasing precipitation and an increase of the detrital contribution within the lake. the phase from 505 ka to 493 ka is characterised by a continuous decrease of the primary productivity as suggested by a decrease in caco3 content; unstable values of δ13c depict an unstable recovery photosynthetic activity; unstable quantities of k, rb, zr, si, ti and ca point to instability of the detrital contribution within the lake as well as of the rates of the bioinduced calcite precipitation. in conclusion, the mercure basin turned out to be a perfect archive for palaeo-environmental and palaeoclimatic studies. moreover, it is possible to extend this kind of analysis to successions covering longer time intervals, like those cropping out to a large extent within the basin. references francke a., wagner b., just j., leicher n., gromig r., baumgarten h., vogel h., lacey j.h., sadori l., wonik t., leng m. j., zanchetta g., sulpizio r., giaccio b. (2016) sedimentological processes and environmental variability at lake ohrid (macedonia, albania) between 637 ka and the present. biogeosciences, 13(4), 1179-1196. giaccio b., galli p., peronace e., arienzo i., nomade s., cavinato g.p., mancini m., messina p., sottili g. (2014) a 560-440 ka tephra record from themercure basin, southern italy: volcanological and tephrostratigraphic implications. journal of quaternary science, 29(3), 232-248. giaccio b., regattieri e., zanchetta g., wagner b., galli p., mannella g., niespolo e., peronace, e., renne p.r., nomade s., cavinato g.p., messina p., sposato a., boschi c., florindo f., marra f., sadori l. (2015) a key continental archive for the last 2 ma of climatic history of the central mediterranean region: a pilot drilling in the fucino basin, central italy. scientific drilling, 20, 13-19. leng m. j., marshall j.d. (2004) palaeoclimate interpretation of stable isotope data from lake sediment archives. quaternary science reviews, 23(7), 811831. regattieri e., giaccio b., nomade s., francke a., vogel h., drysdale r.n., perchiazzi n., wagner b., gemelli m., mazzini i., boschi c., galli p., peronace e. (2017) a last interglacial record of environmental changes from the sulmona basin (central italy). palaeogeography, palaeoclimatology, palaeoecology, 472, 51-66. robustelli g., ermolli e.r., petrosino p., jicha b., sardella r., donato p. (2014) tectonic and climatic control on geomorphological and sedimentary evolution of the mercure basin, southern apennines, italy. geomorphology, 214, 423-435. schiattarella m., torrente m. m., russo f. (1994) analisi strutturale ed osservazioni morfostratigrafiche nel bacino del mercure (confine calabro-lucano). il quaternario, 7(2), 613-626. 124 chiellini m. et al. ms. received: april 27, 2018 final text received: may 23, 2018 03passaroetal integrated geophysical investigation applied to the definition of buried and outcropping targets of archaeological relevance in very shallow water passaro s.1, budillon f.1, ruggieri s.1, bilotti g.2, cipriani m.3, di maio r.4, d’isanto c.1, giordano f.5, leggieri c.3, marsella e.1, soldovieri m.g.4 1 iamc-cnr, napoli, e-mail:salvatore.passaro@iamc.cnr.it 2 area lavori pubblici e demanio marittimo, comune di acropoli 3 soprintendenza per i beni archeologici delle province di salerno, avellino e benevento, salerno 4 dipartimento di scienze della terra, università federico ii, napoli 5 dipartimento di scienze per l'ambiente, università "parthenope", napoli abstract: passaro s. et al., integrated geophysical investigation applied to the definition of buried and outcropping targets of archaeological relevance in very shallow water. (it issn 0394-3356, 2009). the results of a marine survey aimed at detecting archaeological targets in coastal areas by means the integration of different geophysical methods (multibeam bathymetry, high-resolution seismic, geoelectric and magnetism) are presented. the case study is a shipwreck recognised off the shore of agropoli town (salerno, southern italy) over a sandy sea-bottom at about 5 m of water depth. each geophysical method has its peculiarity and detection capability depending on a wide range of factors such as: geological setting, consistency and grain size of sea-bottom sediments, burial and nature (e.g. metallic/non metallic) of the targets, water depth, etc. it is worth stressing that there is a high reduction of the ambiguities inherent in each method when a multiple approach strategy is adopted. we believe that this type of investigation may contribute to establishing a quality standard for such a category of surveys that can be adopted by local administrators and coastal managers wherever archaeological exploration is required. riassunto. passaro s. et al., integrazione di metodi di prospezione geofisici per il rilievo di unità di interesse archeologico (sepolte o sommerse) in ambiente marino costiero. (it issn 0394-3356, 2009). in questo lavoro presentiamo il risultato di indagini effettuate con l’utilizzo di diversi metodi di geofisica marina, finalizzate alla ricerca di oggetti di interesse archeologico in mare (si intendono compresi i relitti storici o contemporanei). rilievi morfo-batimetrici, sismo-acustici, geoelettrici e magnetometrici sono stati effettuati al largo del litorale di agropoli (salerno, italia meridionale) su un relitto di nave della seconda guerra mondiale posto a circa 5 m di profondità su un fondale sabbioso. il caso di studio ha permesso di analizzare problemi ed inconvenienti correlati alle diverse tecniche geofisiche, in relazione a variabili quali: contesto geologico, natura e granulometria dei sedimenti al fondo, grado di seppellimento dell’oggetto, costituzione (metallica/non metallica) degli oggetti o dei relitti, profondità della colonna d’acqua, etc. l’utilizzo incrociato di dati derivanti da più tecniche di acquisizione ha permesso inoltre di ridurre sensibilmente il margine di errore interpretativo sulla natura degli oggetti e/o dei relitti osservati in sito. lo scopo del lavoro è stato quello di individuare criteri standard di riferimento che consentano scelte oggettive delle tecniche di investigazione di geofisica marina da utilizzare per il rinvenimento di relitti in zone costiere. una buona conoscenza, infatti, dei limiti e delle possibilità di ciascun metodo può influenzare positivamente la scelta delle amministrazioni locali impegnate nello sviluppo sostenibile delle zone costiere. keywords:magnetics, marine geoelectrical measurements, multibeam swath bathymetry, monochannel reflection seismic. parole chiave: metodo magnetico, misure geoelettriche, batimetrica multifascio, sismica a riflessione monocanale. il quaternario italian journal of quaternary sciences 22(1), 2009 33-38 1. introduction sea water geophysical exploration aimed towards reidentification of targets of archaeological relevance is strongly constrained by time of data acquisition and processing. feasibility studies in areas with potential archaeological interest are often required to be quick when the presence of a possible target has to be recognised, and this implies the use of exploration methods with a swift data response. in this regard, we have selected some standard geophysical techniques typically used in marine exploration, and tried to analyze them in regards to different aspects. parameters that need to be considered are: geological nature of the investigated sector (volcanic or non-volcanic) provided by magnetic prospecting, textures of bottom sediments (clays, silts, sands or gravel) provided by seismic surveys, while composition and displacement of targets (buried or outcropping), depth of water column might affect the performance of all the techniques here considered. the occurrence of outcropping items is well detected by using morphobathymetric surveys, i.e. multibeam swath bathymetry and side scan sonar. multibeam systems are echosounders, usually mounted on keel, made up of one hundred or more transductors, that allow te mapping of large swaths of the seafloor using acoustic reflections caused by water-sediment interface. side scan sonar systems, typically towed, use internal roughness of materials to explore the seafloor, through the evaluation of lateral backscattering. requirement for buried objects explorations are penetration of sediments without lack of resolution. magnetic surveys are used when expected archaeological targets differ from surrounding materials in terms of internal magnetic susceptibility. high-resolution mono34 s. passaro et al. channel seismic reflection surveys use active acoustic sources (variable in shape, amplitude, frequencies) to provide a sonic section of the subsurface, where anomalies are related to local variations of acoustic impedance (i.e. the product of density and acoustic velocity). the choice of the seismic source-type could be strategic. marine geoelectrical methods, just like on-land measurements, use properties of materials to give different answers to an electrical impulse. local anomalies, due to electrical resistivity contrasts, can be used to identify possible target location. a survey using all of the above methods has been carried out over a submerged beach along the agropoli shore (salerno, italy) by a research team of the institute for coastal and marine environment (iamc) of national research council (cnr), supported by the "parthenope" and “federico ii” universities of naples, with the aim of recognizing buried metrical objects below the sandy seabed. the survey discovered the presence of a shipwreck, that is a military vessel probably sunk during the second world war, in the course of the salerno landing operations. 2. geophysical exploration 2.1 outcropping targets: morphobathymetric surveys (mbes) mbes data records are usually processed with a reply of swaths, and the removal of erroneous measurements (spikes). data are then reorganized in a mxn matrix (digital terrain model, dtm), where every cell of the grid represents a depth quote. swath bathymetry equipments are characterized by frequency-dependent vertical resolution and depthdependent horizontal resolution (“footprint”), the dimensions of which represent a detection limit with respect to the grid cell size of dtm. the reported dataset was collected with a seabat 8125 (reson-thales) echosounder/sonar system with 240 beams, 120° of swath coverage and a pulse frequency of 455 khz, particularly suitable for applications in shallow waters (max 80 metres of depth). nadir areal footprint dimension is a function of depth and technical characteristics of the equipment. in shallow waters, high frequency mbes systems are able to map the seafloor with an adequate grid cell size, clearly showing potential targets. fig.1 is indicative of how fast the resolution degrades with respect to the increment of cell dimensions. where footprint dimensions are not sensibly smaller than the targets, the use of towed side scan sonar (sss) systems is strongly recommended. advantages related to the use of this system are evident, in the sense that sss is considerably closer to the source with respect to mbes. side scan sonar is an acoustic tool used to generate image map of the seafloor and particularly suitable for outcropping target detection. typically, the system's transducer is allocated in a towfish, which is towed through the water a few metres above the bottom. the reflected acoustic returns are processed into an image fig. 1 outcropping bodies are well detected with the use of swath bathymetry. here we show search results through a high resolution 20x20cm dtm (digital terrain model) obtained with the use of reson seabat 8125 multibeam echosounder, and processed with the pds2000 (reson-tales) software (a). this resolution is difficult to obtain, because of the intrinsic instrumental nature (the horizontal resolution is a function of depth of water column and instrumental characteristics, such as number of beams, angle wideness, etc.), but in such cases, multibeam images are equivalent to side scan sonar pictures in terms of horizontal target definition. the obtained dtm shows a perturbation in normal sedimentation, due to shipwreck outcropping, acting as an obstacle for longshore currents (quinn, 2006). b, c and d represents the same data proposed with a grid cell size of 0.5, 1 and 2 metres, respectively. the shipwreck presence (a) is clearly identified only with highest resolution grids (dimensions are 30x10 metres). i target di dimensioni metriche affioranti a fondo mare sono ben evidenziati dai rilievi batimetrici ottenuti con sistemi multifascio. in figura è mostrato un dtm (digital terrain model) alla risoluzione di 20x20 cm, realizzato acquisendo i dati di profondità con il reson seabat 8125 e processando con il software pds2000 (reson-tales). la risoluzione è funzione delle caratteristiche dello strumento utilizzato (numero di beam emessi, ampiezza del fascio) e della profondità d’acqua alla quale si opera. in alcuni casi si possono ottenere immagini multibeam paragonabili, come grado di definizione orizzontale, alle immagini side scan sonar. nell’esempio in figura è visibile la perturbazione del fondale circostante il relitto, dovuta all’interferenza dell’ostacolo con le correnti lungocosta (quinn, 2006). b, c e d mostrano l’area del relitto riproducendo lo stesso dato con tre differenti dimensioni di cella del grid (0.5, 1 e 2 m rispettivamente). la presenza del relitto (a) è chiara solo con la risoluzione massima (dimensioni della figura 30 x 10 m). similar to an aerial photograph, which is viewed realtime on a computer monitor in the towing vessel. typically, the side scan sonar searches a swath that is 60 to 160 feet wide at about 2 miles per hour, although other ranges can be used depending upon the size of the target. these systems represent a fundamental key for target detection, because of their ability to evaluate roughness variations that correspond to change in materials. side scan systems use a sonar device that emits fan-shaped pulses down toward the seafloor across a wide angle perpendicular to the path of the sensor through the water. the transducer may be towed from a surface vessel or submarine, or mounted onto the ship's hull. the acoustic intensity of reflections from the seafloor is recorded on cross-track slices. finally, records are “mosaiced”, in order to obtain a plan view of the bottom that represents a “sonic picture” of the seafloor. this technique appears to be the most suitable for target detection of outcropping objects, although results should not be considered significantly different from multibeam data in very shallow waters. 2.2 buried targets: magnetic survey magnetically susceptible bodies can be easily detected with the use of magnetic methods (boyce et al., 2004), although several problems may arise from the presence of anthropic objects such as pipelines, anchors, chains, etc. the magnetic survey has been carried out in a 10x10 meters grid. data acquisition was performed by using a “seaspy” magnetometer (marine magnetics corporation), with a sensor based on the overhauser effect, with 0.2 nt of accuracy and 0.01 nt of sensitivity. the analytic signal (nabighian, 1972; roest et al., 1992) can help in the identification of the horizontal boundary and in the determination of exact location of the magnetic sources (fig. 2). the analytic signal, a(x,y), is calculated by taking the square root of the sum of the squares of each of the three directional first derivatives of the magnetic field, t, as follows: |a(x,y)|=( (dt/dx ) 2+ (dt/dy ) 2+ (dt/dz)2)1/2 the resulting shape of the analytic signal is independent of the orientation of the magnetization of the source and is centered on the causative body. this has the effect of transforming the shape of the magnetic anomaly from any magnetic inclination to one positive body centered on the anomaly. the used function is based on the u.s.g.s. program pdepth 35integrated geophysical investigation ... (phillips, 1997), through the calculation of the hilbert transform. in the absence of high-frequency noise, local peaks are interpreted as corners of source, and provide a high accurate horizontal location of the magnetic sources. buried metallic objects are clearly identified by means of magnetic surveys, but problems in data acquisition may arise over volcanic areas, particularly in deep waters. 2.3 buried targets: high-resolution seismic survey typical properties of embedded objects are: 1) small dimensions and unknown positions within large survey areas; 2) very weak reflectors due to the attenuation of the overburden sediment material; 3) small differences in the properties of the surrounding sediment, if the object is made of wood and filled with water. a wide range of marine single channel seismic systems are used for high resolution prospecting. their main differences are about the nature of the source (mainly its frequency and amplitude). acknowledged setbacks related to the use of common linear acoustical systems are: 1) low frequencies are required to penetrate the sediment; 2) wide beam width with a large footprint, high reverberation level and low horizontal resolution; 3) have long and ringing transmitter signals and low vertical resolutions and 4) small system bandwidth and low ping rates in the detection of small and weak reflectors. high frequency seismic profilers (chirp, subbottom, etc.) are not significantly penetrative through sand, while sparker systems do not seem to be sufficiently resolutive because of the wide angle of the source fig. 2 a) shaded relief of the multibeam data (grey scaled image) with overlapped (b) the analytic signal coming from the magnetic data (contour map). magnetic boundary are intense around the shipwreck. a) rilievo ombreggiato (in scala di grigio) dei dati multibeam e (b) mappa a curve di livello del segnale analitico calcolato dalle anomalie magnetiche residue del campo misurato. 36 beam. in this sense, boomer systems represent the best technique to ensure both penetration and resolution. the sparker, consisting of an electrode array powered by a capacitor bank of a few hundred joules, has been widely employed for studies on the continental shelf. an electromagnetic source or boomer was developed during the early 1960’s (edgerton and hayward, 1964). seismic energy comes from the sudden separation of an aluminium plate from a flat copper coil embedded in a hard epoxy resin. the plate is initially held against the coil. during the rapid discharge of a bank of capacitors through the coil, eddy currents are induced in the aluminium plate causing a rapid repulsion and the creation of a cavitation volume in the water. the first pressure pulse is due to the rapid outward acceleration of the aluminium plate, followed by a pulse from the implosion of the cavitation volume. boomers (like the eg&g uniboom) with pulse lengths of 0.1-0.2 ms have been developed for reflection profiling in water depths of a few meters. these are able to resolve reflectors less than 0.3 m apart in near-shore sediments (simpkin and davis,1993). sparker and boomer systems have different radiation diagrams: perfect cylindrical symmetry for boomer and very asymmetric and with large angle in the transverse (with respect to navigation) direction for sparker. boomer and uniboom, which we have used for this survey, are both energy limited to 0.5-1kj, while sparker is limited to 3-5kj. results are reported in fig. 3.the eco signals have been acquired and post processed applying band-pass digital filter in order to enhance signal/noise ratio. this operation has been performed by mean the powerful hardware/software platform dseismic. (corradi, 2004) . parametric acoustic systems (like ses 1000 and ses 2000 of innomar technologie gmbh of rostock) represent a new frontier for such problems. they are particularly suitable because of the small footprint, low reverberation level and high horizontal resolution, short transmitting signals without ringing and high vertical resolutions, plus they are able to detect small and weak reflectors 2.4 buried targets: resistivity survey marine geoelectrical measurements coupled with swath bathymetry represent an innovative technique for archaeological target detection in very shallow water and a valid alternative to seismic-acoustic prospection, particularly in marine sectors with sand at the seabed. although this technique is not yet commonly used in geophysical marine exploration, the initial results of our surveys seem to be promising both for archaeological target detection and sedimentological purposes. this method can be used to outline both conductive and resistive bodies, like metallic and wooden objects, respectively. resistivity data acquisition was carried out using a georesistivimeter iris-syscal pro system, with a 2 meter horizontally spaced multielectrode marine cable, and with the use of the sysmar software. the reciprocal wenner array was adopted along a profile that reached a depth of about 8 m below sea level. data inversion was obtained by using the res2dinv algorithm (loke and barker, 1996; loke and dahlin, 2002). the occurrence of the shipwreck is strongly defined in the conductivity map showed in fig. 4 that reports the geoelectrical tomography under a bathymetric map. 3. discussion and conclusions on the basis of the literature the initial approach toward the choice of the most appropriate geophysical technique for marine detection of archaeological tarfig. 3 high resolution seismo-acoustic methods are difficult to use in < 5 metres of water column especially over coarse grained sediments (sands, gravels etc.). most problems are due to strong reflectivity of coarse sediments, ringing of the seismic source, multiple or ghost reflections etc.. all these factors affect both spatial (horizontal) and vertical resolution which must be submetric in case of archaeological targets (belfer et al., 1998; papatheodorou et al., 2005). results of the boomer technique in the study area: lateral changes in amplitude and phase seismic signal in correspondence of the wreck are present (a and b). although lateral variations are clearly visible, it is difficult to relate them to the presence of archaeological bodies, but boomer data may be a valid support for other techniques. i rilievi sismo-acustici in acque basse (>5 m) e in presenza di fondali sabbiosi e ghiaiosi sono estremamente complessi. la riflettività dei sedimenti grossolani, la riverberazione del segnale sismico-acustico, le generazione di riflessioni multiple e i segnali diretti compromettono la qualità dell’acquisizione e il grado di risoluzione (verticale e orizzontale) necessario per evidenziarei target archeologici (belfer et al., 1998; papatheodorou et al., 2005). i risultati ottenuti con la sorgente boomer evidenziano variazioni laterali dell’ampiezza e della fase del segnale sismico in corrispondenza del relitto (a e b), ma non è altrettanto chiara la relazione fra il target e il tipo di anomalia del segnale sismico da esso generato. l’utilizzo di un sistema boomer, pertanto, è consigliabile come integrazione e supporto ad altre tecniche di prospezione. s. passaro et al. 37 gets can be (carefully) traced before hand. results are summarized in table 1 and refer to a mechanism where reciprocal exclusion may provide helpful indications about the adoption of specific surveys. clearly, this scheme assumes a basic knowledge of the area of interest, in terms of average depths of the water column, sediments and geology of the seafloor, presence of possible anthropic targets, etc. reliability of geophysical data is enhanced when a drilling stratigraphy is available for geophysical data calibration. outcropping bodies are well detected by multibeam swath bathymetry when footprint dimension allows horizontal resolution that can be considered equivalent to side scan sonar mapping. nonetheless, side scan sonar systems are to be considered as the essential and more reliable tool for outcropping target recovery. in regards to buried targets, seismic sources (often used in this kind of investigation) should be chosen carefully, according to the indications provided by local sediments and water column depth. in case of fine grained sediments, such as clays or silts (e.g. lakes), the use of frequency-modulated (“chirp”) or fixed frequency subbottom profilers is recommended, while in the case of coarse grained sediments, boomer or parametric systems are more appropriate. in fig. 4 marine geoelectrical measurements coupled with swath bathymetry represent an innovative technique for archaeological target detection in very shallow water and a valid alternative to the seismic-acoustic prospecting, particularly in marine sectors with sand at the seabed. although this technique is not yet commonly used in geophysical marine exploration and needs more refining, preliminary results of our survey seem to be promising for both archaeological target detection and sedimentological purposes. in this picture a 3d conductivity map is represented, which clearly shows the occurrence of an anomaly in correspondence of the shipwreck (imagine on the top). this technique can be easily used in shallow water, while it might be more complicated in other cases because of limitations imposed by cable length. l’acquisizione di dati geoelettrici in ambiente marino integrati con rilievi batimetrici di altissima risoluzione, è una metodica innovativa per l’identificazione di target archeologici in acque basse e rappresenta una possibile alternativa alle prospezioni sismoacustiche, specialmente in presenza di fondali sabbiosi. sebbene in letteratura manchino riferimenti a tali tecniche esplorative in mare e nonostante tali metodiche siano ancora a carattere sperimentale, i risultati preliminari delle indagini effettuate lungo il litorale di agropoli sottolineano come tali procedure siano promettenti sia in campo archeologico che sedimentologico-stratigrafico. in figura è riportata la mappa 3d della conduttività, dove è chiaramente visibile l’anomalia generata dal relitto (immagine in alto). la geoelettrica marina è facilmente utilizzabile in contesti di acqua bassa, mentre in acque profonde il suo uso non è agevole per le limitazioni imposte dalla lunghezza del cavo richiesto. table 1 summary of investigation methods to be used for target detection (see text for details) sintesi dei sistemi utilizzabili per l’identificazione di target archeologici in acque basse. investigation use encouraged use discouraged technique characteristics in presence of: in presence of: outcropping bodies and less more than 50 metres high resolution mbes frequencies (f): than 50 metres of water of water column depth 500-250 khz column depth (use side scan sonar) less than 50 metres of water side scan sonar f of about 400-100 khz outcropping bodies column depth the use of multibeam is equivalent sub-bottom profiler 20 khz > f > 1 khz fine sediments (clays or silts) coarse sediments (sands, gravels) frequency modulated fine sediments coarse sediments (sands, gravels); “chirp” sub-bottom profilers 20 khz > f > 1 khz (clays or silts) poor or null penetration 35-45 khz dual frequency (primary frequency) coarse and fine sedimentsparametric sub-bottom 1-10 khz (secondary frequency) uniboom frequency: 0.2-1 khz fine sediments (traditional, chirp or energy: 0.5-1 kj coarse sediments parametric systems preferable) gradiometers or highly susceptive targets magnetic magnetometers with expected; clearance from volcanic sectors and/or sensitivity of 0.1 nt magnetometer to seafloor not highly anthropized sectors exceeding 20-30 m magnetic gradiometers or highly susceptive targets volcanic sectors and/or magnetometers expected highly anthropized sectors geoelectric 5 metres step cable investigation depth range of 0-7m investigation depth>10m integrated geophysical investigation ... 38 addition, in situations of water depth of less than five metres, the adoption of geoelectrical measurements becomes preferable. magnetic surveys may help to detect both metallic and wooden targets, especially when susceptive bodies (like anchors or armaments) are present, but may be inadequate where low signal to noise ratios are induced, especially in the presence of a volcanic (e.g. lava flows) seafloor or in industrial (e.g. harbours) settings. acknowledgments the authors are grateful to m. fedi and g. de alteriis for their useful comments and reviews that helped us to greatly improve this manuscript references belfer i., bruner i., keydar s., kravtsov a., landa e. (1998) detection of shallow objects using refracted and diffracted seismic waves. journal of applied geophysics, 38 (3), 155-168. belfer i., bruner i., keydar s., kravtsov a., landa e. (1998) detection of shallow objects using refracted and diffracted seismic waves; journal of applied geophysics, volume: 38 , issue: 3, january, pp. 155-168 boyce j., reinhardt e.g., raban a., pozza m.r. (2004) magnetic survey of a submerged roman harbour, caesarea marit ima, israel . the international journal of nautical archaeology, 33 (1), 122–136. corradi n., giordano f., giordano r. (2004) the application of a very high resolution hardwaresoftware (dseismic) system for the acquisition of seismic data for the study of the ross sea (antarctica) sedimentary deposits, proceedings of the italian association of oceanology and limnology, pp. 115-124 edgerton h.f., hayward e.c. (1964) the boomer sonar source for seismic profiling. journal of geophysical research, 69, 3033-3042. loke m.h., barker r.d. (1996) rapid least-squares inversion of apparent resistivity pseudosections by a quasi-newton method . geophysical prospecting 44 (1), 131–152. loke m.h., dahlin t. (2002) a comparison of the gauss-newton and quasi-newton methods in resistivity imaging inversion. journal of applied geophysics, 49 (3), 149-162. nabighian m.n. (1972) the analytic signal of twodimensional magnetic bodies with polygonal cross-section: its properties and use for automated anomaly interpretation. geophysics, 37, 507517. papatheodorou g., geraga m., ferentinos g. (2005) the navarino naval battle site, greece: an integrated remote-sensing survey and a rational management approach. the international journal of nautical archaeology, 34 (1), 95-109. phillips j. d. (1997) potential-field geophysical software for the pc, version 2.2: u. s. geological survey open-file report 97-725, 34 p. quinn r. (2006) the role of scour in shipwreck site formation processes and the preservation of wreckassociated scour signatures in the sedimentary record evidence from seabed and sub-surface data. journal of archaeological science, 33, 1419-1432. roest w.r., verhoef j., pilkinton m. (1992) 3-d analytic signal. geophysics, 57 (1), 116-125. simpkin p.g., davis a. (1993) for seismic profiling in very shallow water, a novel receiver , sea technology, 34 (9), pp. 21–28. ms. ricevuto il 3 ottobre 2008 testo definitivo ricevuto il 16 marzo 2009 ms. received: october 3, 2008 final text received: marchy 16, 2009 s. passaro et al. << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /none /binding /left /calgrayprofile (dot gain 20%) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /error /compatibilitylevel 1.4 /compressobjects /tags /compresspages true /convertimagestoindexed true /passthroughjpegimages true /createjdffile false /createjobticket false /defaultrenderingintent /default /detectblends true /colorconversionstrategy /leavecolorunchanged /dothumbnails false /embedallfonts true /embedjoboptions true /dscreportinglevel 0 /emitdscwarnings false /endpage -1 /imagememory 1048576 /lockdistillerparams false 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<feff4f7f75288fd94e9b8bbe7f6e521b5efa76840020005000440046002065876863ff0c5c065305542b66f49ad8768456fe50cf52068fa87387ff0c4ee575284e8e9ad88d2891cf76845370524d6253537030028be5002000500044004600206587686353ef4ee54f7f752800200020004100630072006f00620061007400204e0e002000520065006100640065007200200035002e00300020548c66f49ad87248672c62535f0030028fd94e9b8bbe7f6e89816c425d4c51655b574f533002> /cht <feff4f7f752890194e9b8a2d5b9a5efa7acb76840020005000440046002065874ef65305542b8f039ad876845f7150cf89e367905ea6ff0c9069752865bc9ad854c18cea76845370524d521753703002005000440046002065874ef653ef4ee54f7f75280020004100630072006f0062006100740020548c002000520065006100640065007200200035002e0030002053ca66f465b07248672c4f86958b555f300290194e9b8a2d5b9a89816c425d4c51655b57578b3002> >> >> setdistillerparams << /hwresolution [2400 2400] /pagesize [595.000 842.000] >> setpagedevice available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 27 30 experimental determination of the friction coefficient for estimating sea storm induced megaboulders movements maurilio milella 1 , giovanni scardino 2 , arcangelo piscitelli 1 , francesco de giosa 1 , giuseppe locuratolo 1 , giovanni barracane 1 1 environmental surveys s.r.l. spin off università degli studi di bari “aldo moro”, taranto, italy 2 dipartimento di scienze della terra e geoambientali, università degli studi di bari “aldo moro”, bari, italy corresponding author: m. milella <maurisismo@libero.it> abstract: the presence of numerous boulders on rocky coast is linked to phenomena of detachment and deposit due to the occurrence of sea storms. currently, several hydrodynamic equations are known in the bibliography to estimate the wave height able to displace them, applying geometric parameters and hydrodynamic coefficients. a new methodological approach intends to consider the minimum energy required for the linear movement of a boulder along a weakly sloping rocky surface as a function of the friction coefficient. keywords: boulders, waves, friction coefficient 1. introduction along the rocky coast of the puglia region it’s evident the presence of geomorphological evidences represented by boulders deposits of various size whose origin has been connected to the occurrence of exceptional waves impact, due to tsunami and/or sea storms (cf. mastronuzzi and pignatelli 2012; pignatelli et al., 2009) (fig. 1). a new study has been carried out on the position and movement of these boulders using a new methodological approach, which consider the displacement of boulders by “many waves” impacting on rocky coast. this new approach requires the knowledge of the dynamic parameters of the rocky surface on which the detachment and displacement process occurs. this study, with respect to the equations known in the bibliography, focuses the attention on the energetic aspects of the storm rather than on the geometric parameter of a single wave. 2. material and methods the preliminary part of a more geographically extended study, has been conducted along a stretch of gently sloping rocky coast in san giovanni of polignano a mare, about 30 km se of the city of bari. in this location there are deposits of calcarenite blocks, from about 1 to 2,5 m3 in size and 2 to 6 ton in weight, and located at different distances from the coast line, whose genesis has already been linked to the occurrence of exceptional fig. 1 boulders deposits in the studied area. https://doi.org/10.26382/aiqua.2018.aiquaconference waves, tsunami and/or storms, following previous studies (cf. mastronuzzi and sansò, 2004; 2000). the adopted methodological approach uses a “many waves” storm energy in place of the wave height, as a hydrodynamic parameter necessary to evaluate the way of moving these blocks. preliminarily, an lst survey was carried out to acquire the geometric characteristics of the rock surface and the shapes of some blocks so as to obtain indications on the general roughness of the contact surfaces and a three-dimensional reconstruction of the same blocks from which their volume can be obtained. the starting point for evaluating the storm waves energy is the following relation (cf. nandasena et al., 2011; noormets et al., 2004; nott, 2003; 1997) (fig. 2): this relationship implies the knowledge of these parameters: θ, slope of the rocky coastal surface; v and ρ, respectively, volume and density of the displaced rocky boulder; μ, the friction coefficient. θ and v were obtained directly from the lst survey and subsequent processing with specific solid modelling software. the parameter ρ is widely tabulated in the specific bibliography (cf. andriani and walsh, 2002). the estimate of the friction coefficient, on the other hand, was carried out using the following method: two boulders, a and b, with two different dimensions but a similar roughness of the contact surface, have been identified directly on rocky platform and chosen for the experimental proofs; then they have been subjected to some linear dragging along a rock surface by means of a mechanical apparatus; all the movement were recorded with a high resolution video camera positioned perpendicular to the direction of movement. the video analysis has allowed to obtain the displacement curve as a function of time (fig. 3), which allowed to obtain the value of the average acceleration necessary to calculate the friction coefficient (fig. 4). 3. results the graphs elaborations obtained through the analysis of the different videos were used to derive the accelerations “a” impressed to the different boulders by a physical apparatus to start and keep a linear displacement; then, these values were put in the inverse relation of the dynamics in order to calculate the friction coeffi 28 fig. 2 sketch of the force acting on a boulder. fig. 3 two different examples of video analysis software. milella m. et al. 29 cient, both static and dynamic, relative to the linear displacement of the considered boulders: the results of the values obtained for the static and dynamic friction coefficient are shown in tab.1. 4. discussion and conclusions the analysis of the results obtained from the graphic elaborations highlights the difference between the values of the static friction coefficient relative to the two sample boulders, a and b, where the “a” coefficient is lower than the “b” one. instead, the values of the dynamic friction coefficient relative to both boulders seem to be quite more similar. these results are certainly a first approach towards the determination of an experimental physical parameter whose value, for this type of lithology, wasn’t found in the reference bibliography. the determination of this coefficient is the first step to better estimate the energy to move a particular boulder on coastal surface and, then, to understand which sea storm can be responsible of this displacement. acknowledgement this work was carried out within the ph.d. project of the “programma operativo nazionale ricerca e innovazione 2014-2020 (cci 2014it16m2op005), fondo sociale europeo, azione i.1 “dottorati innovativi con caratterizzazione industriale”, università degli studi di bari “aldo moro”. references andriani g. f., walsh n. (2002) physical properties and textural parameters of calcarenitic rocks: qualitative evaluations. engineering geology, 67, 5-15. mastronuzzi g., pignatelli c. (2012) the boulder berm of punta saguerra (taranto, italy): a morphological imprint of the rossano calabro tsunami of april 24, 1836? earth planets space, 64, 1-14. mastronuzzi g., sansò p. (2004) large boulder accumulations by extreme waves along the adriatic coast of southern apulia (italy). quaternary international, 120, 173-184. mastronuzzi g., sansò p. (2000) boulders transport by catastrophic waves along the ionian coast of apulia (southern italy). marine geology, 170, 93103. nandasena n.a.k., paris r., tanaka n. (2011) reassessment of hydrodynamic equations: minimum flow velocity to initiate boulder transport by high energy events (storms, tsunamis). marine geolfig. 4 two different examples of speed/time graphic. tab. 1 friction coefficient values. “mi”: number of movement. experimental determination of the friction coefficient ogy, 281, 70-84. noormets r., crook k., felton e. (2004) sedimentology of rocky shorelines: hydrodynamics of megaclast emplacement and transport on a shore platform, oahu, hawaii. sedimentary geology, issue 172, 41-65. nott j. (1997) extremely high wave deposits inside the great barrier reef, australia; determining the cause tsunami or tropical cyclone. marine geology, 141, 193-207. nott j. (2003) waves, coastal boulders and the importance of the pre-transport setting. earth and planetary science letters, 210, 269-276. pignatelli c., sansò p., mastronuzzi g. (2009) evaluation of tsunami flooding using geomorphologic evidence. marine geology, 260, 6-18. 30 milella m. et al. ms. received: may 11, 2018 final text received: may 21, 2018 imp.gregori la “memoria” geologico-geomorfologica in alcune città dell’umbria e dintorni attraverso i materiali dell’antico edificato urbano lucilia gregori dipartimento di scienze della terra università degli studi di perugia, lucilia@unipg.it riassunto: l. gregori, la “memoria” geologico-geomorfologica in alcune città dell’umbria e dintorni attraverso i materiali dell’antico edificato urbano (it issn 0394-3356, 2007). nell’ umbria è presente una ampia variabilità litologica e geomorfologica: i litotipi calcarei delle strutture appenniniche bordano la regione verso e mentre quelli silico-clastici affiorano nella porzione occidentale; nell’area ancora più sud-occidentale, invece, sono presenti rocce ignee e, da n verso s, si sviluppa una delle più grandi depressioni intermontane umbre rappresentata dal lago tiberino, che ha permesso la sedimentazione di importanti spessori di depositi fluvio-lacustri. in particolare, si può notare come la memoria “storica” dei passati paesaggi geologici si evinca anche dall’ edificato urbano più antico che racconta attraverso le cinta murarie, i monumenti, ma più spesso le semplici abitazioni, il primo paesaggio di cui gli abitanti dei luoghi hanno fruito come materiale da costruzione. il centro storico di città della pieve, infatti, si erge al top del delta del paleo-nestore e, con i suoi depositi, sono state edificate le mura ed i palazzi del centro abitato mentre, l’ etrusca orvieto ricava dalla piastra tufacea della sua “mesa”, la roccia per costruire la città epigea e le tombe al di fuori delle mura cittadine. anche le tombe estrusche dell’ipogeo del volumni, a perugia, ubicate nella parte medio-distale del paleo-delta del f.tevere, sono situate in ambienti scavati all’interno dei depositi deltizi. la bella civita, la “città che muore”, presso bagnoregio è costruita con la roccia tufacea e basaltica su cui è ubicata, mentre l’antica carsulae, presso terni, si fregia nel suo antico sviluppo urbano dei calcari e dei travertini della struttura dei m. martani; infine, la città di assisi che appare “rosea” perché, ancora oggi, edificata con la scaglia rossa della serie umbro-marchigiana. questi esempi rappresentano solo alcune delle realtà litologico-archeologiche presenti nel tessuto urbano delle città dell’umbria. le vicende geologiche e il conseguente paesaggio hanno decisamente condizionato non solo l’ubicazione delle città, ma anche la loro tipologia edilizia che si è avvalsa, quasi sempre, dei materiali “autoctoni”. la locale storia geologico-geomorfologica ha trasmesso, pertanto, all’edificato urbano un importante valore scientifico e culturale. abstract: l. gregori, geologic-geomorphologic “memory” in some of umbria's cities and surroundings by means of ancient urban building materials. (it issn 0394-3356, 2007). the complex geological history of umbria has led to an extreme lithological and geomorphological variability. calcareous lithotypes are present, deriving from apenninic structures, bordering the region towards east, while siliciclastic lithotypes crop out in the west part of the region and igneous rock in the south-east part. the whole region is crossed from north to south by one of the greatest intramountain depressions in umbria, i.e. the tiberino lake, which has allowed the sedimentation of imposing fluvial and lake deposits. the historical “memory” of the past geologic landscapes can be deducted also by means of the most ancient urban buildings. the city walls, the monuments and also the simple houses of common people bear witness of the landscapes where the early inhabitants of the region used to carve out building materials. typical examples are the town of città della pieve, located on top of the nestore paleoriver which supplied raw materials for walls and buildings, and the etruscan town of orvieto, where the tufaceous stone has been carved out from the mesa to build the underground town and the tombs outside the city walls. also the etruscan tombs of the volumi hypogeum, located at the fore/bottom-set of the tevere river paleodelta, are carved into deltaic deposits and behind the tombs of the etruscan noble families conglomerated banks crop out, alternated by sands and/or muds. the beautiful town of civita, “the dying town” near bagnoregio is carved out directly from the tufaceous and basaltic stone onto which it lays and the ancient town of carsulae, near terni, has used for its urban developments calcareous and travertines materials coming from martani mountains. finally, the world famous city of assisi has its buildings and churches built from the typical pink stone extracted from the quarry of the subasio mountain. these are some of the examples representing litho-archaeologic situations in the urban fabric of umbria's cities.the geologic history and the subsequent surfaces aspect of the region have definitely influenced not only the location of urban sites but also their building typology which, almost always, has made use of the native raw materials provided by the geologic and geomorphologic history of the region, assigning to them a great value both scientifically and culturally. parole chiave: paleogeografia,geomorfologia,geo-archeologia, umbria. keywords: palaeogeography,geomorphology,geo-archaeology, umbria region. il quaternario italian journal of quaternary sciences 19(2), 2006 269-278 1. introduzione il presente lavoro vuole proporre una conoscenza dell’umbria attraverso una nuova chiave di lettura, quella degli elementi geologici e geomorfologici del territorio. la geodiversità umbra conseguenza delle sua storia geologica ed evolutiva si traduce in una grande varietà di paesaggi percepibili, con un metodo di indagine non tradizionale, anche attraverso le differenti tipologie dell’edificato delle città. la “memoria storica” (sensu piacente & poli, 2003) dei luoghi umbri racconta di concentrazioni urbane in siti rilevati come al top dei paleo-conoidi, luoghi privilegiati per motivi strategici e di salubrità (in umbria, nelle depressioni occupate dai laghi era presente, fino a 270 l. gregori tempi storici, la malaria) o arroccate nell’alto delle inespugnabili mesa o lungo le sponde dei fiumi, talora, uniche vie di penetrazione nel territorio. uomo e territorio sono pertanto fortemente collegati: il substrato geologico con le vicende geomorfologiche che lo hanno interessato ha quindi, influenzato lo sviluppo demografico costituendo non solo un semplice bed-rock ma, talora, attraverso i diversi litotipi in affioramento, ha fornito il materiale da costruzione o modellato superfici, talora rilevate, risultate idonee all’edificazione; le situazioni ambientali indotte da alcuni processi morfogenetici, inoltre, potevano rappresentare una risorsa (ad es.: pedogenesi) o un ostacolo (aree in frana) all’antropizzazione. e’ interessante notare come dall’analisi, quindi, delle relazioni tra la tipologia edilizia delle città e le caratteristiche geologico-geomorfologiche del sito su cui esse si sono sviluppate, emerga la memoria di antichi paesaggi ambientali. l’edificato urbano, infatti, più o meno datato (in alcune località, come assisi, persiste ancora la tradizione dell’uso edilizio del litotipo locale) racconta, attraverso i monumenti, ma più spesso attraverso le normali abitazioni, l’antico scenario geologico. saranno, pertanto, proposte nel presente lavoro alcune situazioni in umbria, interessanti sotto questo aspetto e nell’ottica di un approccio divulgativo, ma scientificamente rigoroso. il percorso proposto, infatti, evidenzia ed integra gli aspetti scientifici dei luoghi con le loro peculiarità artistico-monumentali e il loro generale valore ambientale: cogliere gli elementi geologici anche nell’edificato delle città può pertanto rappresentare una insolita e stimolante modalità di divulgare tematiche geologico-geomorfologiche. 1.1 inquadramento geologico-geomorfologico la complessa storia evolutiva dell’ umbria ha determinato una estrema variabilità litologica e morfologica nel territorio della regione (jacobacci et al.,1970): le strutture appenniniche la limitano verso est, attraverso la sequenza delle anticlinali calcaree est-vergenti, mentre litotipi silico-clastici affiorano prevalentemente nella porzione più occidentale dove i rilievi, in virtù del minore dislivello, hanno una diversa evidenza dal punto di vista morfologico (fig.1a). nell’area più sud-occidentale, invece, sono presenti le rocce ignee del vulcanismo pleistocenico che conferiscono al paesaggio morfosculture abbastanza spettacolari (gregori et al., 2005). tutta la regione, infine, da n verso s è attraversata da una delle più grandi conche intermontane pliopleistoceniche umbre, rappresentata dall’antico bacino tiberino (lotti, 1926; cattuto et al., 1992) : questa ampia depressione di origine tettonica assume una forma a “y” rovesciata e, all’altezza del centro abitato di perugia, si divide in due “rami”, uno orientale diretto verso spoleto ed uno occidentale fino a todi/corbara (fig. 1b). nel lagotiberino sono stati deposti, a partire dal pliocene, imponenti spessori di depositi fluvio-lacustri e/o palustri e, pertanto, la storia del bacino ha avuto un importante ruolo nell’evoluzione morfologica del territorio. nella porzione più sud-occidentale della regione, infine, l’evento morfologico più recente è rappresentato dalle colate laviche dell’apparato di bolsena, giunte fino alla valle del f.paglia, a ne di orvieto; si tratta delle vulcaniti vulsine: tufi stratificati/colate leucitiche, ignimbriti del pleistocene medio (cattuto, cencetti & gregori in aa.vv.,1994; stoppa in aa.vv.,1994) modellate, nelle spettacolari mesa, dai successivi processi morfogenetifig. 1 – (a) inquadramento geografico e geologico schematico dell’umbria (modificato da guzzetti & cardinali,1989: 1) formazioni calcaree e calcareo-marnose della serie umbro marchigiana (giura-oligocene); 2) formazioni torbiditiche (miocene); 3) depositi di facies marina, salmastra e continentale (plio-pleistocene); 4) depositi vulcanici dei m. vulsini (pleistocene). (b) il lago tiberino (lotti,1926). geographic and geological arrangement of the umbria region (modified by guzzetti & cardinali,1989): 1) calcareous formations.of umbria-marchigiana serie (giura-oligocene); 2) torbiditic formations (miocene); 3) sea and continental deposits (plio-pleistocene); 4) volcanic deposits (pleistocene). (b) the tiberino lake. a) b) ci (weathering, morfoselezione, frane, ecc.). nell’umbria, a grande scala, si possono quindi individuare quattro unità di paesaggio (sensu ecologia del paesaggio; delcourt & delcourt,1988): quella dei rilievi calcarei, quella dei più modesti rilievi arenacei e l’unità delle zone depresse occupate prevalentemente da depositi fluvio-lacustri mentre, a sé stante, è quella rappresentata dal dominio vulcanico. tali diverse unità geologiche hanno portato a significative differenze morfologiche e quindi ambientali s.l. condizionando l’evoluzione del paesaggio sia naturale che antropico. 2. la litologia di alcuni siti e monumenti umbri vengono, di seguito, individuati alcuni siti in umbria le cui caratteristiche litologiche sono chiaramente riconoscibili nelle strutture edilizie delle città, al fine di cogliere quegli elementi di carattere geologicogeomorfologico e sedimentologico che possano essere trasmessi ad una utenza culturalmente più ampia. 2.1 dal paleo-delta di città della pieve al conoide di foligno nell’area settentrionale dell’ umbria affiorano, quindi, prevalentemente rocce arenacee che costituiscono sia i versanti dell’alta valle del f. tevere, che i rilievi che bordano il lago trasimeno e, in continuità litologica e morfologica, interessano anche le confinanti colline toscane. nella zona di città di castello di conseguenza, si rileva a scopo edilizio, l’uso della roccia appartenente alla formazione della marnoso-arenacea (successione etrusca o dell’umbria occidentale; in damiani in aa.vv.,1994) e, nell’area del lago trasimeno, delle arenarie del trasimeno e/o “macigno” riferite all’oligocene superiore (damiani in aa.vv.,1994) e denominate anche “pietra serena”. sia i pregevoli palazzi nobiliari di note città che i suggestivi casolari delle campagne toscane ed umbre, creano una continuità edilizia, ben raccordata, al diffuso affioramento delle rocce silico-clastiche. il paesaggio tosco-umbro, infatti, ha un aspetto litologico e cromatico caratteristico che però muta decisamente, andando verso s. procedendo verso se, in corrispondenza dei rilievi calcarei, analogo condizionamento geologico-strutturale si rileva nei centri abitati appenninici, attraverso la pietra calcarea squadrata del palazzo dei consoli di gubbio, della rocca di gualdo tadino e di tutti quei centri abitati, ubicati al contatto tra il bed-rock e le sottostanti pianure. le sinclinali arenacee e le anticlinali calcaree si potrebbero evincere anche dalla variabilità edilizia, attraverso una procedura analitica assolutamente non tradizionale, ma in linea con l’orientamento e la “filosofia” della geomorfologia culturale (panizza & piacente, 2003; 2005). verso w, le rocce affiorati denunciano la presenza, nel pliocene, di una linea di costa verso cui si dirigevano i corsi d’acqua dell’entroterra, edificando estesi corpi deltizi. e’ interessante notare come il centro abitato di città della pieve si collochi al di sopra di un ampio delta che appare morfologicamente rilevato rispetto alla valle del t.chiani; la cittadina si staglia, infatti, sul fronte 271la “memoria” geologico-geomorfologica in alcune città ... del rilievo deltizio edificato, nel pliocene, dal paleonestore insieme ad un deflusso, proveniente grossomodo da n (cattuto et al.,1992; gregori, 2005) e diretto verso la paleo costa, ubicata lungo l’attuale valle del f.paglia. la serie deltizia pievese, è costituita dalla nota successione sedimentaria pliocenica suddivisa in argille di fabro, sabbie a flabellipecten e conglomerato di città della pieve (ambrosetti & basilici in aa.vv.,1994). la morfoscultura che progradava verso ovest, ha così fornito, attraverso i depositi grossolani di top-set, la materia prima per costruire le mura ed i palazzi della città. i ciottoli arrotondati dell’antica piana deltizia prospiciente l’antico mare pliocenico, sono stati messi in opera interi o dimezzati (fig. 2), producendo uno stile edilizio ed una sorta di decorazione reiterata che contraddistingue la cittadina ma che, generalmente, sfugge ad uno “sguardo non geologico”. la città, nel suo insieme, assume inoltre una colorazione rossastra per il laterizio diffusamente utilizzato, anche per la facile reperibilità in loco, dell’argilla presente lungo l’area corrispondente alla costa pliocenica ed alla porzione distale del delta pievese (fig. 3). questo antico scenario è fig. 2 i ciottoli del top-set del paleo-delta del f. nestore nelle mura di città della pieve. the cobblestones of the paleo-delta topset of the nestore river, in the town walls of città della pieve. fig. 3 dem (regione umbria) del paleo-delta di città della pieve. digital elevation model (umbria region) of the paleo-delta in città della pieve. 272 percepibile anche nell’edificato più antico della città dove, è interessante osservare la pila sedimentaria (banconi di conglomerati e sabbie) dei depositi deltizi che “affiora” anche lungo le pareti degli edifici più datati, come le cantine storiche della città. la fattura delle antiche mura, in particolare, appare molto originale e colpisce un osservatore molto attento per l’originale tipologia edil izia, incrementata del suo “valore paleogeografico” che fornisce, pertanto, un tipo di informazione, ai più sconosciuta, ma che diventa anche messaggio scientifico. stessa tecnica edilizia è stata adottata anche in altre situazioni in umbria, e si può riconoscere, ad esempio, lungo alcune porzioni delle mura esterne di foligno. la città è ubicata, nel ramo orientale del paleo-lago tiberino, ai piedi della struttura m.brunette/ m serano, in corrispondenza dello sbocco nella valle umbra del f.topino. il bacino idrografico del fiume insiste prevalentemente sui litotipi calcarei della serie umbro-marchigiana, compresi fra il lias inferiore ed il miocene superiore-oligocene (dal calcare massiccio alla marnoso-arenacea; accordi & moretti, 1967). la presenza e la provenienza dei ciottoli usati nella costruzione della cinta muraria è una chiara evidenza sedimentologica legata all’ evoluzione dell’antico delta-conoide del paleo -topino, che progradava, verso w e sul quale la città è stata edificata.tale estesa morfoscultura, che ha avuto un ruolo importante nell’evoluzione del lago tiberino, non ha una chiara evidenza morfologica (ben desumibile attraverso elaborazioni digitali; fig. 4) per cui appare poco rilevata (foligno è comunemente definita “città di pianura”); una passeggiata, tuttavia, lungo le mura esterne (fig. 5), permette di cogliere un uso di materiali, simile a quella di città della pieve e di percepire processi morfogenetici ed un paleo-ambiente oggi non più riconoscibile a causa, anche, degli effetti della forte pressione antropica locale. questa integrazione fisica tra paleo-forme ed urbanizzazione è riconoscibile in molte località: città della pieve, foligno, montefalco ed anche perugia sono solo alcune delle “città-conoidi” umbre edificate al di sopra e con i materiali di questi estesi corpi sedimentari, che progradavano in mare o nei numerosi laghi umbri (localmente fusi nel grande bacino tiberino) e che, con le loro evidenze morfologiche e litologiche, hanno comunque segnato il destino e l’aspetto delle future città. 2.2 il paleo-delta del f. tevere particolarmente significativo è l’esempio della città di perugia, edificata sul top-set del paleo-delta del f.tevere. una suggestiva evidenza morfologico-sedimentologica del processo fluviale si rileva, quindi, nel fig. 4 dem modificato del conoide del f. topino (melelli, 2004). modified dem of the topino river fan. fig. 5 i ciottoli calcarei del f.topino nelle mura della città di foligno. town walls of foligno, built using calcareous cobblestones from the topino river. territorio perugino costituito da depositi continentali fluvio-lacustri, rilevabili lungo l’apparato deltizio che, nel pliocene, si gettava nel lago tiberino, a s di perugia ed il cui profilo è ancora riconoscibile percorrendo la stral. gregori 273 da che, da perugia, scende verso la valle del tevere. al raccordo con la pianura che si estende, infatti, ai piedi della città (presso ponte s.giovanni), in corrispondenza del passaggio fra i depositi di fore-set e bottom-set del paleo-delta, sono ubicate le splendide tombe etrusche dell’ipogeo del volumni. le urne sepolcrali, realizzate prevalentemente in travertino, si trovano all’interno di ambienti scavati nei depositi medio-distali del delta; alle spalle delle raffinate sculture delle urne, raffiguranti gli appartenenti alle nobili famiglie etrusche affiorano, infatti, i banconi conglomeratici alternati a finissime sabbie e limi cementali (fig. 6), clino-stratificati verso quella pianura, una volta occupata dal lago tiberino. la visita all’ ipogeo può costituire, così, un esempio eclatante e particolarmente interessante di “sinergia culturale” tra sedimentologia, geomorfologia ed archeologia, per una migliore comprensione dei luoghi e una nuova “percezione” dei loro processi naturali e antropici. 2.3 le “mesa” di orvieto e di civita/bagnoregio nell’area sud-occidentale dell’umbria, come accennato, litotipi e forme sono abbastanza esclusive e diverse da tutto il resto della regione: sono presenti litotipi vulcanici legati all’ attività dell’apparato di bolsena e tale evento morfologico è ben evidente nel tessuto urbano dei locali centri abitati. l’ orvieto etrusca è fondata su un piastrone tufaceo (ignimbrite di orvieto; giacomelli & scandone, 2002) della potenza massima di 70m, che nel pleistocene medio (da 600.000 a 300.000 anni fa; giacomelli & scandone, 2002) si è messo in posto al di sopra della serie dell’albornoz (livelli di materiali sedimentari e/o vulcanici; pialli et al., 1978) e delle argille marine plioceniche. l’acropoli appare, quindi, in continuità litologica con il banco piroclastico della sua mesa, e non risulta percepibile, neanche dal punto di vista cromatico, il passaggio dalla roccia in posto della rupe di orvieto alle pietre, squadrate o lavorate, messe in opera nell’edificato. la rupe, inoltre, è “svuotata” al suo interno, dalla storica coltivazione di antiche ed ampie cave sotterranee finalizzate, sia alla costruzione della orvieto epigea che delle tombe immediatamente a ridosso della rupe e dei “santuari” (come il tempio federale fanum voltumnae ritrovato, in recenti scavi archeologici, in corrispondenza dell’ antico “lago di velzna”, in località “campo della fiera”, tra la mesa di orvieto e il plateau alfino) (fig. 7; cattuto et al., 2002). la roccia vulcanica, quindi, ha accompagnato in questo luogo, le vicende dell’ uomo in tutte le fasi della vita, a partire dalle pregevoli decorazioni negli stipiti delle porte orvietane, alle curiose colombaie (fig. 8) lungo il perimetro esterno della rupe, alle capienti cisterne ipogee, utilizzate per la conservazione dell’acqua e l’ invecchiamento del vino, fino agli edifici sepolcrali (bizzarri,1998). l’edilizia moderna si avvale ancora dei basalti dell’alfina, materiale caratterizzato da ottime fig. 6 l’ ipogeo dei volumni: nelle cripte sono visibili i depositi del paleo-delta del f.tevere. the volumni hypogeum: conglomerated deposits of the tevere river’s paleo-delta are visibile in the crypts. fig. 7 frammento di antefissa a testa di satiro, riferita a materiali fittili, lungo una strada realizzata con “basoli” di leucitite e basalto (campo della fiera nei pressi di orvieto in cattuto et al., 2002). fragment of antefissa, representing the head of a satyr.. it refers to ancient fictile materials and it has been discovered near a road built with "basoli" (flog-stones) of leucitite and basalt, in the town of campo della fiera, near orvieto (cattuto et al., 2002). la “memoria” geologico-geomorfologica in alcune città ... 274 qualità geomeccaniche, quando lastricava, oggi come nel passato, con stupendi “basolati” (fig. 9) le strade tra l’altopiano alfino e la mesa orvietana (cattuto et al., 2002). nell’estremo sud-occidentale dell’umbria, ed in continuità litologia con l’altopiano dell’alfina, nei pressi di bagnoregio (al confine umbria-lazio) si trova il centro abitato di civita (fig.10), la famosa ed unica “città che muore”. anche in questo caso, il centro abitato è edificato esclusivamente con la roccia tufacea (“tufo di bagnoregio”; giacomelli & scandone, 2002) sulla quale e della quale è costruita: piccola mesa circondata da un biancheggiante e dinamico paesaggio a calanchi. la sequenza delle rocce ignee, ben esposta alla base del moderno ponte che permette l’accesso a civita, è costituita da prodotti ignimbritici sedimentati al di sopra delle argille plio-pleistoceniche (giacomelli & scandone, 2002). il suggestivo panorama dei calanchi, che si gode dall’alto dei giardini arroccati sul bordo esterno della mesa, è frutto di processi di erosione e fenomeni gravitativi che minacciano l’integrità e la stabilità del nucleo storico, e per questo, recentemente, nell’area interessata dai fenomeni calanchivi sono stati condotti interventi di bonifica. la necessaria salvaguardia del sito storicomonumentale, unico nel suo genere, ha imposto la stabilizzazione dei versanti tufaceo-argillosi su cui poggiano le vulcaniti, ma con la graduale ed inevitabile perdita di uno scenografico paesaggio naturale esclusivo, nel suo genere. in questo caso, il contributo di discipline come la geologia, la geomorfologia e la geologia applicata si integrano perfettamente in un contesto “geoturistico”, per una più profonda acquisizione delle caratteristiche del luogo. 2.4 le rocce carbonatiche nell’edificato umbro le rocce carbonatiche sono presenti in quasi tutta la parte più rilevata della regione ed, in particolare, assumono un ruolo importante nell’architettura di città turisticamente note come assisi, perugia,spoleto, ecc. l’area centro-meridionale dell’umbria (spoletoterni) è caratterizzata prevalentemente dai litotipi carbonatici della serie umbro-marchigiana. le rocce calcaree delle strutture umbre sono presenti, per esempio, a spoleto sia nei monumenti all’interno della città (es.: l’arco di druso, le fontane, le abitazioni più datate ed alcune chiese come il duomo) che nel ponte delle torri, al di fuori delle mura storiche.i calcari del m.luco e delle strutture bordiere del versante orientale della valle umbra (monti di campello) sono stati utilizzati per la realizzazione di parte delle alte ed imponenti arcate dello spettacolare ponte, simbolo storico e culturale della città (fig. 11a). nei pressi della città affiorano, infatti, prevalentemente litotipi delle formazioni giurassiche della serie u.m.(dal calcare massiccio, corniola e rosso ammonitici fino alla scaglia). anche l’antica carsulae, presso terni, nell’umbria meridionale, si fregia nel suo antico sviluppo urbano e monumentale, delle rocce calcare che provengono dalla struttura dei m. martani (fig.12) e degli estesi affioramenti di travertino presenti nelle vicinanze: calcari e travertini biancheggiano vistosamente nei ruderi della città. un’ampia fascia travertinosa potente 50m si trova lungo il versante occidentale dei m.martani, da acquasparta f ino alla placca dei travertini di fig.8 le colombaie ricavate lungo il bordo della rupe di orvieto. the dovecots carved into the edge of the orvieto cliff. fig. 9 un antico “basolato” ai piedi dell’altopiano dell’alfina; la superficie pianeggiante del plateau è visibile sullo sfondo (cattuto et al., 2002). an ancient “basolato” at the base of the alfina plateau and the plane surface its visible in the background (cattuto et al.,2002). l. gregori 275 a) b) fig. 10 il centro abitato di civita (a) e la sua piazza principale (b) “ raccontano” la roccia vulcanica della mesa. the centre of the civita village (a) and the main square (b) tell about the volcanic rock of the “mesa”. a) b) a) b) fig. 11 spoleto: il ponte delle torri costruito con conci di calcare dei “monti di spoleto” (a) e la fontana del mascherone in travertino (b). spoleto: the “towers bridge”, built with calcareous rocks from the spoleto mountains (a) and the mascherone fountain, built using travertine (b). fig.12 carsulae: calcare e travertino nel lastricato della via flaminia; sullo sfondo i rilievi della struttura dei m.martani (a) e nelle vestigia monumentali dell’arco di s. damiano (b). carsulae: limestone and travertine in the flaminia road paving ; in the background, the relieves of the martani mountains (a) and the monumental vestiges of s. damiano arch (b). la “memoria” geologico-geomorfologica in alcune città ... s.terenziano (pleistocene; ambrosetti & basilici in aa.vv. 1994). i materiali utilizzati nelle decorazioni di molti monumenti e fontane dell’umbria (fig.11b), inoltre, provengono dalle zone citate e dagli altri depositi di travertino abbastanza diffusi nella regione : i banchi di s.sabina, grutti s.terenziano, i travertini lungo il f. menotre presso la cascata di pale, fino allo spesso banco (circa 100m) che affiora lungo la valle del f.velino e nel salto della cascata delle marmore (frondini & peruzzi in aa.vv.,1994; gregori & troiani, 2005), all’estremo meridionale del paleo-lago tiberino. il travertino, inoltre, è presente, e non solo come pietra ornamentale, in molti edifici storici delle città umbre: l’ arco etrusco e la cinta muraria etrusca del nucleo storico perugino (le mura etrusche in travertino sono all’interno della cinta medievale in arenaria), sono state edificate con blocchi squadrati di roccia, proveniente dagli estesi affioramenti di s. sabina (*), località nei pressi di perugia (fig. 13). sono riconoscibili ancora calcari, nel paesaggio urbano di assisi che assume nell’insieme una tonalità “rosata”, a causa della roccia calcarea locale, detta “pietra di assisi” (fig. 14) usata, da tempi immemorabili, 276 a) b) fig.13 l’arco etrusco (a) e le mura, di perugia (b), edificate con il travertino che affiora in località s. sabina (presso perugia). in perugia, the etruscan arch (a) and the town walls (b) were built using travertine cropping out in the s.sabina area (near perugia). a) b) fig. 14 la scaglia rossa visibile in affioramento, a contatto con le mura storiche (a) e nell’ usuale edificato urbano di assisi (b). the “scaglia rosata” stone appears at the contact with historical walls (a) and it is also commonly used as building material in the town of assisi (b). l. gregori per la costruzione dei palazzi e delle decorazioni e presente nei fregi e nei pavimenti delle celebri chiese assisane; la roccia, squadrata dal lavoro di generazioni di abili scalpellini, proviene dalla formazione della scaglia rossa (cretaceo medio-eocene medio; aa.vv.1994) della serie umbro-marchigiana, presente lungo i versanti del m. subasio, il “monte” di assisi. lungo la brachianticlinale del m.subasio affiorano, infatti, le rocce della successione sedimentaria di età compresa fra il lias inferiore ed il miocene medio (passeri in aa.vv, 1994) rappresentate, tra le altre, dalla scaglia bianca e dalla scaglia rossa; mentre la prima è presente discontinuamente, la seconda si rileva sulla sommità e lungo il versante orientale del m. subasio (venturi & rossi, 2003) e il suo colore rosso/rosato ha conferito una inconfondibile connotazione all’aspetto di assisi. la città, noto centro internazionale della tradizione religiosa, possiede pertanto un “valore aggiunto” rappresentato dallo storico uso della roccia nelle sue mura, chiese, piazze, ecc., in una architettura fortemente legata al paesaggio geologico locale. stesso bi-cromatismo litologico (bianco-rosso) si riscontra anche nel materiale usato nella costruzione dei palazzi e dei monumenti-simbolo della vicina città di perugia (per perseguire l’alternanza del bianco-rosa, a perugia come ad assisi, al “rosa” della scaglia locale veniva, talora, affiancato anche il “rosso di verona”; fig. 15). 3. conclusioni tutti gli esempi riportati, rappresentano solamente alcune delle situazioni “litologico-archeologiche” presenti nel tessuto urbano di alcune città dell’umbria e dintorni, che raccontano processi e forme appartenenti ad un passato, geologicamente e morfologicamente, non sempre, molto lontano. le vicende geologiche e il conseguente modellato superficiale dei luoghi, infatti, hanno decisamente condizionato, non solo l’ubicazione dei siti urbani, ma anche la tipologia edilizia delle città che si è avvalsa, quasi sempre, dei materiali “autoctoni” che la storia geologica ha trasmesso, assegnando ai centri storici, contemporaneamente, un importante valore scientifico e culturale. tali valenze, purtroppo, rimangono sempre più spesso confinate alle strutture storiche, poichè la moderna ed uniforme tipologia edilizia tende, in genere, a spersonalizzare il “paesaggio storico-ambientale”, non permettendo più, almeno per un certo periodo storico (gli anni del boom edilizio), di riconoscerne il contesto territoriale. la conoscenza geologica e geomorfologica, tuttavia, del territorio attraverso anche una normale gita all’interno dei centri storici è una “pratica turistica” che andrebbe favorita, poiché consente la“percezione” e l’acquisizione di contenuti culturali non scontati e, talora, insospettati. (*) comunicazione orale del prof. giampiero poli – università di perugia) bibliografia accordi b. & moretti a. (1967) note illustrative della carta geologica d’italia, alla scala 1:100.000. foglio 131 foligno, servizio geologico d’italia, poligrafica & cartevalori. ercolano napoli, 61 pp. aa.vv.(1994) guide geologiche regionali.15 itinerari. appennino umbro-marchigiano. soc. geol. italiana, be-ma editore, 301 pp. bizzarri c. (1998) orvieto underground. betagamma editrice, 47pp. cattuto c. cencetti c.& gregori l. (1992) il pliopleistocene nell’area meridionale del bacino del f.tevere: possibile modello morfotettonico. studi geol. camerti, 1, p.103-108, 3ff, 1 tav.f.t. cattuto c. gregori l., rapicetta s., bizzarri c., giontella c. & stopponi s. (2002) gis e geoarcheologia in località campo della fiera presso orvieto (tr). atti della 6a conferenza naz. asita geomatica per l’ambiente, i l territorio e i l patrimonio culturale. 2, p. 705-714, 9ff. 277 a) b) fig. 15 l’acropoli perugina denuncia, attraverso i suoi monumenti-simbolo la litologia locale: la fontana maggiore (a) e la facciata della cattedrale di s.lorenzo (b). the acropolis of perugia, through its monuments, tell about the local lithology: the fontana maggiore (a) and the facade of s. lorenzo’s cathedral (b). la “memoria” geologico-geomorfologica in alcune città ... delcourt h.r. & delcourt p.a. (1988) quaternary landscape ecology: relevant scales in space and time. landscape ecology, 2, p.23-44. giacomelli l.& scandone r. (2002) vulcani e eruzioni. pitagora editrice bologna, 278 pp. gregori l. (2005) il lago trasimeno: dalla carta storica al dem, boll.ass. ital. di cartografia, n. 123-124, 69-95. gregori l., melelli l., rapicetta s. & taramelli a. (2005) principal geomorphosites in umbria region. il quaternario, vol. speciale a cura di piacente & coratza, geomorphological sites and geodiversity, 18, 1,p.93-101. gregori l.& troiani c. (2005) la cascata delle marmore (terni/umbria):storia ed evoluzione di un “geomorfosito”. boll. ass. italiana cartografia, 123-124, p. 69-95. jacobacci a., bergomi c., centamore e., malatesta a., malferrari n., martelli g., pannuzzi l.& zattini n. (1970) note illustrative della carta geologica d’italia, alla scala 1:100.000. fogli 115 “città di castello” 122 “perugia” 130 “orvieto”. servizio geologico d’italia. 151 pp. lotti b.(1926) descrizione geologica dell’umbria. mem. descrittive della carta geologica d’italia, 21, 320 pp., 65 ff., 6 tavv., 2 carte. melelli l. (2004) i dem derivati da sistemi radar:uno strumento per l'idenficazione dei conoidi alluvionali. atti della 8a conferenza naz. asita, 2, p.14451450,3ff. panizza m. & piacente s. (2003) geomorfologia culturale. pitagora editrice bologna, 350 pp. piacente s. & poli g. (2003) la memoria della terra-la terra della memoria, università degli studi di modena e reggio emilia-regione emilia e romagna, bologna, grafiche damiani, pp. 158 panizza m. & piacente s. (2005) geomorphosites: a bridge betwenn scientific research,cultural integration and artistic suggestion. il quaternario volume speciale a cura di piacente & coratza, geomorphological sites and geodiversity 18, 1, p. 3-10. pialli g., martini e. & sabatini p. (1978) contributo alla conoscenza della geologia del colle di orvieto. boll.soc. geol., 97, p. 103-114, 10ff. guzzetti f. & cardinali m.(1989) carta inventario dei movimenti franosi della regione dell’umbria ed aree limitrofe in: studio dei centri abitati instabili in umbria a cura di felicioni s. martini e. & ribaldi c., rubbettino editore, catanzaro, 1995, 418 pp. venturi f. & rossi s. (2003) subasio. origine e vicende di un monte appenninico.tipolito properzio snc, assisi/pg, 112 pp. 278 ms. ricevuto il 20 febbraio 2006 testo definitivo ricevuto il 31 ottobre 2006 ms. received: februaryr 20, 2006 final text received: octobe 31, 2006 l. gregori amq abs maceroni et al tepro 221-224.pub available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, abstracts, aiqa 13-14/06/2018 florence, 221 224 application of quaternary studies for the assessment of active and capable faults in the central apennines: implications for microzonation and seismotectonic analyses deborah maceroni 1, simone racano 1, emanuela falcucci 2, stefano gori 2, fabrizio galadini 2 1 università degli studi roma tre, roma, italy 2 ingv istituto nazionale di geofisica e vulcanologia, roma, italy corresponding author: d. maceroni <deb.mac993@gmail.com> abstract: the study of the quaternary evolution of defined areas for the recognition and characterization of active and capable faults is essential for an adequate and aware land use planning and management. here, we present two case studies in the abruzzi apennines, one in the celano area, where focused geological studies allowed us to rule out the presence of an active and capable fault in a site selected for the realization of a primary school, and one in the bagno area, where an active and capable fault has been first detected and should be included in revised seismic microzonation studies. keywords: quaternary, seismic microzonation, active and capable faults, palaeoseismology, central apennines 1. introduction the study of the quaternary geological evolution of tectonically active areas is fundamental to define the recent kinematic history of faults, both for seismotectonic studies and, in urban areas, for planning activities aimed at reducing the risk connected to the fault activity. the central apennine is characterized by a number of normal faults active through the quaternary, which are considered the surface expression of seismogenic sources potentially responsible for m 6.5-7 seismic events. the faults generally bound to the north-east the intermontane basins where cities, villages and urban areas are mostly located. in this work, we present two case studies in the abruzzi region, one in the fucino basin and one in the l’aquila basin, to show the application of quaternary geological studies to active and capable faulting assessment, and their effectiveness in land use planning and management, in particular in terms of planning actions aimed at reducing the related risks. the first case study is located in the town of celano (aq), along the northern margin of the fucino basin, where a complex quaternary normal-fault arrangement is shown by the available literature (e.g. galadini and messina, 2004). the 1st level of seismic microzonation studies performed in the area indicates the presence of an active and capable fault and defines a large setback (according to the linee guida per la gestione del territorio in aree interessate da faglie attive e capaci) which encompasses the area of the “ex campo bonaldi”, that was formerly selected for the realization of a school. the active and capable faults database ithaca reports an active and capable fault in the site of the school (fig. 1), related to the northern portion of the fucino fault system (cavinato et al., 2002; bianchi fasani et al., 2008). the second case study is in the area of bagno (aq), in the l’aquila basins. here, nocentini et al. (2017) hypothesised the presence of a normal fault in the area, that is not reported in the 1st level seismic microzonation studies performed in the area after the 2009 l’aquila earthquake. 2. materials and methods a multidisciplinary approach is applied to the identification of active and capable faults in the two case studies. in particular, we carried out geological surveys and aerial photo interpretation aimed at defining the quaternary morpho-stratigraphic setting useful to cast light on the recent fault activity. in both case studies, we performed palaeoseismological investigations to unravel the possible presence of active and capable faults and, if any, to investigate their recent activity. as for the celano area, we also performed two boreholes with the goal of achieving more robust chrono-stratigraphic data in the site of the school. 3. results 3.1. celano the trench at the “ex campo bonaldi” site (fig. 2) exposed five continental units which were not affected by any fault plane. the absence of dislocation is also confirmed by the horizontal stratigraphic continuity of the sequence cored by the boreholes we made at the extremities of the trench. the geological field survey of the quaternary units we made in the area of celano gave evidence of late quaternary activity of nw-se trending faults, comprising the santa iona normal fault, which displaced eluvial deposits deriving from deposits of the second sedimentary https://doi.org/10.26382/aiqua.2018.aiquaconference fucino cycle (bosi et al, 2003), related to the early pleistocene. differently, n-s trending normal faults that affect the western slope of the serra di celano relief are clearly sealed by early pleistocene breccias, thus testifying inactivity of these structures in recent times. 3.2. bagno the geological-geomorphological survey in the area of bagno piccolo revealed the presence of a scarp oriented nw-se and dipping toward ne. an excavation for a building made along the scarp (fig. 3a) allowed us to first reveal the presence of a normal shear zone which 222 fig. 1 red lines show active and capable faults from database ithaca in the town of celano. maceroni d., et al. fig. 2. stratigraphy of eastern wall of the palaeosismological trench. five continental units have been recognized: colluvial deposits (brown and yellow), paleosol (blue) and alluvial deposits (pink and violet). 223 brought into contact miocene flysch and quaternary deposits (alluvial fan and colluvial sediments) (fig. 3b). following nocentini et al. (2017), the alluvial fan deposits can be related to the “sintema di campo di pile”, dated to the late pleistocene. this indicates a late quaternary activity of the fault. further analyses are still ongoing to better characterise the recent movements of this fault zone. 4. discussion and conclusions the field geological survey and the analysis of trenches allowed to verify or exclude the presence of faults in the investigated sites and to achieve a better definition of the quaternary activity of the identified faults. in the case of celano, we didn’t find any evidence of active faulting in the area of the “ex campo bonaldi”, where the ithaca database suggests the presence of fig. 3 example of cave dug into the tuff. a) view of a chamber with an access well on top; b) details of access realized with steps directly carved into the tuff. active faults studies for land use management fig. 3 a) bagno piccolo locality crossed by a scarp, marked by the red dashed line. b) normal fault zone (red line) that placed into contact miocene flysch with continental deposits. an active and capable fault. we found evidence of late quaternary activity in the area of celano along nw-se trending faults (especially along the santa iona fault), which confirms the probable structural linkage between the “strada statale marsicana” segment of the active fucino fault and the monti della magnola segment (galadini et al, 1998; galli et al, 2012). moreover, the absence of late quaternary activity along the n-s trending normal faults located along the western slope of the serra di celano relief highlights the probable lack of structural linkage between the fucino and ovindolipezza fault systems. regarding the bagno piccolo case study, the first identification of a probable active and capable normal fault provides new important information on active faults affecting the l’aquila area and new detailed data for the seismic microzonation in the area struck by the 2009 earthquake. references bianchi fasani g., cavinato g.p., petitta m., scarascia mugnozza g., voltaggio m. (2008) the geological model of celano town area for seismic microzonation activities. soil dynamics and earthquake engineering, 28, 978-985. bosi c., galadini f., giaccio b., messina p., sposato a. (2003) plio-quaternary continental deposits in the latium abruzzi apennines: the correlation of geological events across different intermontane basins. il quaternario,16(1bis), 55-76. cavinato g. p., carusi c., dall’asta m., miccadei e., piacentini t., (2002) sedimentary and tectonic evolution of plio-pleistocene alluvial and lacustrine deposits of fucino basin (central italy). sedimentary geology, 148, 29-59. galadini f., messina p. (2004) early-middle pleistocene eastward migration of the abruzzi apennine (central italy) extensional domain. journal of geodynamics., 37, 57-81 galadini f., galli p., molin d. (1998) caratteristiche della sismicità della zona del fucino (italia centrale): implicazioni sismotettoniche. il quaternario, 11 (2), 1998, 179 189. galli p., messina p., giaccio b., peronace e., quadrio b. (2012) early pleistocene to late holocene activity of the magnola fault (fucino fault system, central italy). bollettino di geofisica teorica ed applicata 53(4), 435-458. nocentini m., asti r., cosentino d., durante f., gliozzi e., macerola l., tallini m. (2017) plio quaternary geology of l’aquila scoppito basin (central italy). journal of maps, 13(2), 563-574. catalogo italy hazard from capable faults (ithaca) of the istituto superiore per la protezione e la ricerca ambientale (ispra) (http://www.sgi. isprambiente.it/geoportal/catalog/progect/ithaca.page) (last check of availability may 2018). commissione tecnica per la microzonazione sismica (2015) linee guida per la gestione del territorio in aree interessate da faglie attive e capaci (fac), versione 1.0 conferenza delle regioni e delle provincie autonome-dipartimento della protezione civile, roma, 2015. ms. received: may 6, 2018 final text received: may 24, 2018 224 maceroni d., et al. late pleistocene travertines and their analogues under deposition. a comparative analysis erlisiana anzalone1 1istituto per l'ambiente marino costiero, iamc (cnr), napoli, e-mail: erlisiana.anzalone@iamc.cnr.it abstract: anzalone e.: late pleistocene travertines and their analogues underdeposition. a comparative analysis. (it issn 0394-3356, 2008). textures, sedimentary structures and o-isotope data from the late pleistocene travertines cropping out at pontecagnano-faiano (salerno) are here compared with carbonate incrustations under formation within an adjacent irrigation channel. fossil system. a complex paleo-environmental dynamics is documented in the travertine fossil system, spanning in age from 90 ka b.p. (±10ka) at the base, to 55ka b.p. (±10ka) at about 15 m from the summit surface. in this system, aggradational and progradational growth-geometries developed starting from an original gentle slope, that was increasing gradually its inclination while growing downhill. this resulted into a number of rapids and waterfalls at the margins of this system leaving behind flat terrace where swamps and/or shallow lakes developed. the travertine growth was interrupted, at time, by non deposition and/or erosional processes, both documented by discontinuity surfaces. this organization suggests a recurrent dropping of the groundwater level and a decreasing spring-water outflow, considered as due to climatic changes. moreover, oxygen isotope data have been measured lamina-by-lamina on stromatolitic travertines in which recurrence of the chironomid larvae galleries in the sparitic laminae suggests seasonal variations as also confirmed by the small isotope oscillations (dispersion of about 0,6 ‰ δ units) documented in the laminae of the stromatolitic fabric. present-day incrustations. the present-day incrustations derive from waters flowing along an artificial channel fed by springs that has been used as a gentle “slope” depositional analogue of the adjacent fossil deposits. the time-space evolution of the depositing incrustations shows growth geometries well comparable to those occurring at a larger scale in the fossil system. the incrustations develop downhill and from the margins towards the channel axis both through progradational and aggradational geometries. small barrages and domes (mounds) take form where the carbonate calcium precipitation rate is higher, while micropools tend to spread behind these structures. these depositional structures tend to level themselves to the channel upper surface. the oxygen-isotope data measured in the channel incrustations document small seasonal oscillations (dispersion of about 0,6 ‰ δ units) that do not differ from those recorded in the fossil stromatolitic deposits. based on the above results a sedimentary model is proposed here, that may bear also on the terraced morphology of other quaternary ambient-water travertines riassunto: anzalone e.: travertini del pleistocene superiore e loro analoghi attuali. analisi comparativa. (it issn 0394-3356, 2008). lo studio comparato dei travertini tardo-pleistocenici e di quelli attualmente in formazione, nell'area di pontecagnano-faiano (salerno, campania), ha consentito di analizzarne la loro dinamica ambientale e di evidenziare le loro analogie. sistema fossile. le relazioni stratigrafiche tra le differenti associazioni di litofacies e gli originari ambienti sedimentari mostrano nel sistema fossile ricorrenze di tessiture-strutture sedimentarie registrate a scala da decimetrica a metrica e testimoniate da geometrie di crescita sia aggradazionali che progradazionali. queste, nel complesso, suggeriscono che i processi di incrostazione sono iniziati su un originario pendio poco acclive. la successiva evoluzione ambientale ha portato all'aumento di acclività sul fronte del deposito mentre alla sommità si aveva la formazione di un terrazzo deposizionale con lo sviluppo di facies palustri/lacustri mentre depositi di rapida e/o cascata ne caratterizzavano i margini. frequenti discontinuità sono registrate a scala da decimetrica a metrica e indicano una generale modalità di crescita per “pulsazioni”, legate a ricorrenti fasi di abbassamento del livello di falda, con conseguente diminuzione della portata alla sorgente. questa ultima è probabilmente collegata a variazioni della piovosità. il controllo climatico è comunque più chiaramente registrato nei depositi stromatolitici dove le variazioni stagionali sono suggerite sia dalla presenza delle gallerie di chironomidi nelle lamine spatitiche, sia da piccole e regolari oscillazioni degli isotopi dell'ossigeno (dispersione dei valori di circa 0,6 ‰ unità δ). depositi attuali. queste oscillazioni sono strettamente comparabili con quelle misurate nelle incrostazioni attuali monitorate lungo un canale di irrigazione, che può essere considerato come l'equivalente di un paleo-pendio. lungo il canale la dinamica ambientale è prevalentemente regolata dai tassi di precipitazione. laddove questi (a loro volta controllati dalle variazioni dell'idrodinamica e della morfologia del substrato) sono più alti, si osserva lo sviluppo di piccole barre e strutture domiformi. queste si accrescono sia verso valle che dai margini verso l'asse del canale, sviluppando geometrie di progradazione e di aggradazione. il processo di crescita porta gradualmente alla diffusione di piccole pozze nelle aree retrostanti le barre fino al riempimento del canale che viene ripulito dalle incrostazioni due volte l' anno. l'analisi comparata della dinamica ambientale dei travertini tardopleistocenici e attuali di pontecagnano-faiano suggerisce un modello sedimentario che può spiegare lo sviluppo di morfologie terrazzate osservabile anche in altri sistemi travertinosi fossili. keywords: travertines, calcium-carbonate incrustations, sedimentology, environmental dynamics, oxygen-isotope, climatic control. parole chiave: travertini, incrostazioni carbonatiche, sedimentologia, dinamica ambientale, isotopi dell'ossigeno, controllo climatico. il quaternario italian journal of quaternary sciences 21(1b), 2008 91-98 1. introduction in the last few years, much scientific interest has been addressed to non marine carbonates and in particular to the late quaternary travertine deposits, which have been considered in terms of complex depositional systems and used as paleoclimatic proxies. their geological importance is due to the primary carbonate precipitation that is largely controlled by physico-chemical processes (outgassing of co2, ph variation, water temperature, hydrodynamics and so on) and biological activity (mainly microbial and/or algal); both, in turn, are influenced by climate variability (e . g . he n n i n g et al. , 1983; julia, 1983; chafetz and folk, 1984; matsuoka et al., 2001; soligo et al., 2002; ihnlefield et al., 2003; pentecost, 2004; anzalone, 2005; andrews, 2006; carthew et al., 2006; an z a l o n e et al., 2007). travertines are widespread in central and southern italy where they 92 e. anzalone deposited in the late pleistocene-holocene times, during interglacial warm-wet climatic intervals characterized by increasing volume of the spring waters in the mountain foothills and by forest expansion (e.g. br a ncaccio et al., 1988; crombie et al., 1997; martin-algarra et al., 2003). although the sedimentary organization of different travertine deposits shows similar gross features, two end-members can be distinguished: ambient-water and hot-water travertines (e.g. golubic et al., 1993; violante et al., 1994; d'ar g e n i o, 2001; d'ar g e n i o and fe r r e r i, 2004). in particular, the lithofacies diversity and the biogenic imprint carried by primary travertine incrustations provide good criteria of distinction between ambientand hot-water fossil deposits, both at the outcrop and at microscopic scale. in fact, to higher temperature at the spring, lower abundance, size and diversity of the colonizing organisms correspond (e . g . vi o l a n t e et al. , 1994; d'argenio, 2001). in southern europe, the sites where travertine incrustions are currently forming are rather rare and the deposition rate scarce. active travertine systems have been analyzed investigating : a) calcium carbonate precipitation processes (c f r . he r m a n and lo r a h, 1988); b) parent-water chemistry (pentecost, 1995) and c) carbon and oxygen isotope composition. actually from few years, active travertine systems have been considered as “natural laboratories” to analyse their growth mode and to compare them to fossil systems, trying to recognize in them a climatic signal. the present study is mainly based on a comparative analysis between late pleistocene travertines and present-day incrustations, the latter under deposition along an irrigation channel, seasonally digged1. both deposits are located in the vicinities of pontecagnanofaiano village (salerno, fig. 1). the main analogies between the fossil and the active system are discussed, using also new data collected during the last two years (a) to inquire on the large scale control mechanisms by confronting fossil with present-day incrustations; (b) to better delineate the depositional architecture and environmental dynamics of the fossil travertines, allowing their sedimentary model to be delineated and (c) to add new evidence to the climatic significance of the o-isotope signal already measured during the years 2002-2003. 2. sedimentology the pontecagnano-faiano fossil and present-day travertines crop out at the southern side of the picentini mountains (campania apennines), whose large-scale tectonic organization consists in a multilayer of structural units mainly made of mesozoic carbonate rocks and subordinately by tertiary terrigenous deposits (fig. 1, see also d'argenio et al., 1987; casciello et al., 2006). late pleistocene travertines the fossil deposits, cropping out at about 10 km south-east of salerno, are 90 metres thick, roughly clino-stratified to the south-southwest and range in age from 90 ka (±10ka) b.p. to 55ka (±10ka) b.p. (the last figure refers to a sample collected at about 15 m from the summit surface, c f r. an z a l o n e, 2005; an z a l o n e e t al., 2007). textures and related sedimentary structures have been classified in terms of lithofacies and lithofacies associations (see ferreri, 1985; d'argenio and ferreri, 2004 for terminology). in particular, textures made up by in situ carbonate incrustations (stromatolitic, microhermal and phytohermal lithofacies) or by incrusted plant fragments (phytoclasts) have been recognised. the in situ deposits (stromatolitic and microhermal), associated with phytoclastic travertines, are widespread in the lower-middle part of the travertine body; they are weakly clino-stratified to the south-south west and consist of gentle to steep slope deposits (fig. 2 a, b). subvertical structures (drapes), formed of phytohermal and microhermal textures, characterise the current travertine margins and indicate rapid to waterfall deposits (fig. 2c). finally, sub-horizontal deposits, represented by poorly stratified phytoclastic sands with lensoid travertine intercalations, characterise the topmost part of the travertine terrace; they consist of shallow lake to swamp deposits (fig. 2d). the time-space stratigraphic relationships among the above deposits allow to infer that the carbonate precipitation initiated on a gentle slope surface, laterally and downhill evolving into steeper slopes and rapid-waterfall structures. this depositional dynamics is testified by cmto m-scale growth geometries that suggest, on the whole, a progradation of the fossil system towards south and southwest. analogously, the upward travertine growth is documented by cmto m-scale growth geometries resulting in a terraced surface where shallowlake and swamp deposits are widespread. these growth geometries imply that the springs originating the pontecagnano-faiano fossil deposits were located towards the north. moreover, several discontinuity surfaces, recurring at dmto metrescale intervals, suggest that the travertine growth was often interrupted by not-depositional and/or erosional processes due to recurrent dropping of the groundwater levels and decreasing spring-water outflow (anzalone et al., 2007). in conclusion, the complex interplay between paleoenvironmental and paleohydrological dynamics fig. 1. pontecagnano-faiano travertines (salerno district, southern italy). 1. sedimentary substrate. 2. pontecagnanofaiano travertines. 3. post-travertine alluvial deposits. on the left: location of the studied area. travertini di pontecagnano-faiano (salerno, italia meridionale). 1. substrato sedimentario. 2. travertini di pontecagnanofaiano. 3. depositi alluvionali successivi a quelli di travertino. nel riquadro in basso a sinistra l'area oggetto di questo lavoro. 1 for further information on the main physico-chemical processes controlling the formation of the present-day deposits see anzalone et al. (2007). resulted, on the whole, in a final construction of a terraced morphology. sette bocche channel travertines in the studied area, several springs are, at the present, precipitating calcium carbonate deposits along irrigation channels. one of these gullies (the easternmost of an e-w gentle arched array of seven springs, named sette bocche channel) is about 2500 m long, 1 m deep and 1,5-2 m wide, with an acclivity of about 5°. it is located at northeast of the town of pontecagnanofaiano and from the year 2002 has been used as a natural laboratory. the water temperature is about 17°c; this value does not show significant changes during the sampled period. moreover, the water-com93late pleistocene travertines ... position is richer in mg2 + and ca2 + rather than in other ions, reflecting the predominant carbonatic nature of the aquifer. at the spring, the concentration gradient of atmospheric co2 and the dissolved co2 in waters emerging from the aquifer produce co2 outgassing (cfr. e.g. lu et al., 2000; anzalone et al., 2007). as the concentration moves toward the equilibrium, the water becomes supersaturated with caco3, the ph increases (values around 7.5) with carbonate precipitation starting at about 200 m from the spring (figs. 3 a, b). calcium carbonates continue to deposit downstream for about 1,2 km and then start rapidly to decrease, until the waters spill into a permanent rivulet, the asa torrent, where there is not calcium carbonate precipitation at all. fig. 2 schematic model showing the vertical (“aggradational”) and longitudinal (“progradational”) growth dynamics of the fossil system. (a) weakly clinostratified phytoclastic travertines, the arrow shows a lensoid microhermal intercalation: gentle slope facies. (b) clinostratified phytoclastic deposits: steeper slope facies, (c) subvertical “drapes” formed of incrustations on mosses: waterfall facies. (d) poorly stratified phytoclastic sands: shallow lake facies. modello schematico mostrante la dinamica di crescita verticale (geometrie di aggradazione) e laterale-frontale (geometrie di progradazione) del sistema fossile. (a) travertini fitoclastici in strati leggermente inclinati; la freccia indica piccola intercalazione lentiforme di travertino microermale: pendio poco acclive. (b) travertini fitoclastici clinostratificati: pendio acclive. (c) travertini a muschi in “drappi” subverticali: depositi di cascata. (d) sabbie fitoclastiche a stratificazione indistinta: facies lacustre. the process of travertine deposition, controlled by hydrodynamics and substrate morphology, is discussed here to show how changes in precipitation and accumulation rates modify the gully morphology. higher caco3 precipitation rates (about 4-6 cm/month) prevailingly occur at small slope-breaks. at these breaks, barand dome-geometries (“mounds”) develop, with their main axis perpendicular to the direction of the water flow (figs. 3 c, d). such mounds are characterized by in situ microhermal incrustations, mostly on vaucheria or mosses, locally associated with phytoclastic travertines. the water velocity strongly influences the growth dynamics and the morphology of these small constructions. arcuate small barrages, showing frontal steep-slopes and characterized by prevailing progradational geometries, grow under higher hydrodynamics conditions. conversely, behind these small channel barrages, cmto dm size microponds gradually take form, where the lower water flux favours development of prevailingly aggradational growth geometries. moreover, higher caco3 precipitation rates also occur at the channel margins, where a series of cm-size “microhermal mounds” (prevailingly made of incrustations on the green alga vaucheria) develop with inward and downhill progradational geometries, gradually occluding the channel lumen (figs. 3 e, f). from the above data it is suggested that the present-day travertine incrustations within the channel reach values exceeding 3000 m3 per year; the caco3 precipitates grow through aggradational and progradational geometries, levelling themselves to the water channel upper surface at least twice a year, with an interval of few weeks for digging operations. 3. stable isotope geochemistry a detailed geochemical analyses of rocks and parent waters has been carried out on numerous samples. bulk sample stable-isotope analyses have been performed by automated continuous flow carbonate preparation using a gasbenchii device and a thermoelectron delta plus xp mass spectrometer, at the isotope geochemistry laboratory of the iamc-cnr (naples). standard deviations of the oxygen isotope measures were estimated 0.08 per mill on the basis of about 10% repeated samples. 3.1. late pleistocene travertines oxygen isotope analyses have been made on several lithofacies corresponding to different paleoenvironments, excluding samples affected by diagenetic modifications. the data show that analogous values occur in the phytoclastic as well as in the microhermal and stromatolitic textures suggesting, on the whole, their independence from the primary depositional characteristics. paleo-temperatures of the parent waters have been investigated. the o-isotope values, spanning from -4.50‰ to 6.51‰ vs. vpdb with a dispersion of about 2 ‰ δ units, indicate deposition from ambient-temperature waters. in addition, these values are closely comparable to those measured on the channel incrustations (an z a l o n e, 2004; an z a l o n e et al. , 2007). in the last two years new o-isotope data have been collected, lamina-by-lamina, from the stromatolitic intervals that form repeated, 8-10 cm thick, bundles. in these deposits, recurrence of galleries produced by chironomid larvae in the sparitic laminae indicates that such laminae formed during a spring-summer season (cfr. e.g. irion and muller, 1968). minor isotope oscillations (about 0.6‰ value dispersion) are here documented that are well comparable with those discussed in anzalone et al. (2007). moreover they appear superimposed on centimetre to metre scale trends (dispersion of about 1,6 ‰ δ units) suggesting a hierarchical organization probably linked to external (climatic) control (fig. 4, see also anzalone, 2005). 3.2. sette bocche channel deposits the oxygen isotope study carried out on samples collected during the years 2006-2007 shows that the δ1 8o mean values are about -5.93‰ vs. vpdb in spring-summer and about -5.54‰ vs. vpdb in autumn-winter, with no regard to the primary textures (normally microhermal). these mean seasonal values almost coincide with those previously measured during the years 2002-2003 (c f r . an z a l o n e et al., 2007) and are in agreement with several authors, reporting analogous results for other active precipitating travertine systems (cfr. ch a f e t z e t al., 1991; matsuoka et al., 2001, kano et al., 2003; ihlenf i e l d et al., 2003). moreover, it is worth noting that a value dispersion of about 0,6‰ δ units is recorded, closely comparable to that measured in the laminae of the fossil stromatolitic travertines with chironomid galleries. here small seasonal variations are clearly documented. 4. discussion and conclusions the present study is based on a comparison between the late pleistocene ambient-water travertines and the present-day carbonate incrustations, both cropping out at pontecagnano-faiano (near salerno, campania). the active incrustations are here analyzed to better define the environmental dynamics of the fossil system. the stratigraphic relationships between the different lithofacies associations (and related paleoenvironments) have been studied at cmto mscale. they indicate multiscale constructional trends, also testified by aggradational and progradational growth geometries. moreover they suggest a sedimentary evolution from an original gentle slope to a terraced morphology; here shallow-lakes to swamps and rapids to waterfalls were developing at the top and at the margins, respectively. in addition, more or less evident discontinuity surfaces are documented at decimetre to metre scale intervals, that suggests recurrent gaps in the sedimentary record due to lowering of ground-water levels and consequent decreasing spring-water flow. the climatic control on these features is clearly documented at a seasonal scale by small isotope oscillations (dispersion of about 0,6 per mill δ units) measured on the stromatolitic fossil deposits (see also an z a l o n e et al., 2007 for further comments). the present-day travertines have been analyzed at pontecagnano-faiano, along an artificial channel fed by spring waters (sette bocche spring), to study chemico-physical processes influencing the travertine deposition. here hydrodynamic and substrate morpho94 e. anzalone logy changes, both controlling calcium-carbonate precipitation rates and deriving sediments, have been investigated. the calcium carbonate precipitation starts at about 200 m from the spring and develops for about 1200 m, the higher values occurring at small breaks as well as at the channel margins. this allows aggradational and progradational growth-geometries to be developed that are comparable to those recognized, at a larger scale, in the slope facies of the fossil system (fig. 2). moreover, the oxygen-isotope oscillations (dispersion of about 0,6 per mill δ units), measured across the present-day carbonate incrustations, document small seasonal changes. these new collected data are well comparable to those measured on the fossil deposits as well as to those already discussed in anzalone et al. (2007). 95 fig. 3. present-day travertine incrustations. (a) upper part of the sette bocche channel (about 200 metre from the spring). (b) carbonate incrustations on the green alga v a u c h e r i a sp.. (c) small slope-break where a v a u c h e r i a “mound” develops, showing a downhill growth. (d) small slope-break occurring downhill; here a phytoclastic barrage develops. (e) progressive infilling of the channel, from its margins to its axis. (f) occlusion of the channel due to the travertine incrustation growth. see the text for further explanation. travertino in formazione. (a) parte alta del canale sette bocche a circa 200 metri dalla sorgente. (b) incrostazioni sull'alga verde vaucheria sp. (c) piccola rottura di pendenza in corrispondenza della quale si sviluppa un “mound” a vaucheria sp. (d) piccola rottura di pendenza verso valle; dove si sviluppa una barra di travertino fitoclastico. (e) progressivo riempimento del canale per crescita delle incrostazioni dai margini verso l'asse. (f) occlusione del canale dovuta ad incrostazioni. vedi il testo per ulteriori spiegazioni. late pleistocene travertines ... from the above results, the following conclusions may be briefly delineated: (a) comparable aggradational and progradational growth geometries may be recognized in the fossil and present-day travertines, suggesting that their depositional dynamics is strongly controlled by changes in the water-flow characteristics, in turn controlled by climate. this may also explain the “pulsating” growth of the fossil travertines, suggested by the frequent discontinuity surfaces, the latter recurring at dmto m-scale intervals in the stratigraphic record; (b) the oxygen isotope values indicate that analogous temperatures (about 17° c) may be estimated for both the fossil and the present-day parent-waters; moreover, their hierarchical organization (from cmto m-scale intervals, fig. 4), may indicate an external control on fossil travertine formation, probably linked to climatic change. this is also suggested by the seasonal variations, at a mm-scale, recorded in the stromatolitic deposits; (c) based on the above analogies between fossil and present-day travertines, a sedimentary model is proposed that well explains the terraced morphology of the pontecagnano-faiano fossil system; this model may be considered also to interpret the depositional dynamics of other quaternary ambient-water travertine terraces. acknowledgements this paper is an outcome of a program on carbonate sediments and rocks of the i.a.m.c. (istituto per l'ambiente marino costiero), cnr, naples, that is acknowledged for the support to the present research. the isotopic measures have been carr ied out at geochemical laboratory of iamc-cnr. i would like to express my gratitude to prof. vittoria ferreri and prof. bruno d'argenio (dipartimento di scienze della terra, “federico ii” university, naples) for their scientific suggestions and help. moreover, i am grateful to dott. mario sprovieri (iamc; cnr, naples) for the fruitful discussions on stable-isotopes and mr. michele iavarone for technical support with stable-isotope analyses. references andrews j.e. (2006) palaeoclimatic records from stable isotopes in riverine tufas: synthesis and review. earth-science review; 75; 85-104. anzalone e. (2004) approccio integrato allo studio dei travertini. il caso di pontecagnano aiol conference, naples 4-5november 2003, pp 1-9. an z a l o n e e. (2005) i travertini di pontecagnano (salerno) e loro relazioni con le variazioni ambien96 fig. 4 faiano. late pleistocene travertines. upper row: phytoclastic travertine associated with stromatolitic and microhermal travertine (slope facies), on the right, the vertical variation of the lithofacies and their thickness. lower row : oxygen isotope oscillations measured on 13 samples collected at centimetre scale; the square indicates a stromatolitic interval, about 6 cm thick, measured lamina by lamina. the small oscillations (dispersion of 0,6 ‰ δ units), on the right, record a seasonal signal. faiano. travertini del pleistocene superiore. sopra: aff ioramento di travertino fitoclastico associato a livelli di travertino microermale e di travert ino stromatol itico (ambiente di pendio), a destra colonna l itologica mostrante la variazione verticale delle litofacies e del loro spessore. sotto: variazioni degli isotopi dell'ossigeno registrate in 13 campioni raccolt i a scala centimetrica; il riquadro indica un intervallo di circa 6 cm di spessore di travertino stromatolitico misurato lamina per lamina. le piccole oscillazioni ottenute (dispersione di circa 0,6 ‰ uni tà δ ) , mostrate a destra, indicano un segnale stagionale. e. anzalone tali e climatiche del quaternario italiano. tesi di dottorato in scienze della terra, università degli studi "federico ii" di napoli, pp 1-210, non pubblicata. an z a l o n e e., fe r r e r i v., sp r o v i e r i m., d'ar g e n i o b . (2007) travertines as paleohydrologic archives. the case of pontecagnano. advances in water resource, 30, 2159-2175. br a n c a c c i o l., d'ar g e n i o b., fe r r e r i v., st a n z i o n e d . , taddeucci a., voltaggio m. (1988) i travertini di rocchetta a volturno (molise). datazioni con 230th e modello deposizionale. memorie società geologica italiana; 41, 673-83. carthew k.d., taylor m.p., drysdale r.n. (2006) an environmental model of fluvial tufas in the monsoonal tropics, barkly karst, northern australia. geomorphology; 73, 78100. ca s c i e l l o e., ce s a r a n o m. a n d pa p p o n e g. (2006). extensional detachment faulting on the tyrrhenian margin of the southern apennines contractional belt (italy). journal of the geological society, jul; 163, 617 629. chafetz h.s., folk r.l.(1984) travertine. depositional morphology and bacterially constructed constit u e n t s. journal of sedimentary petrology; 5 4, 289-316. ch a f e t z h.s., la w r e n c e r. (1994) stable isotopic variability within modern travertines. geogr. phys. quat.; 48, 257-273. ch a f e t z h.s., ru s h p.f., ut e c h n.m. (1991) m i c r o environmental controls on mineralogy and habit of caco3 precipitates : an example from an active travertine system. sedimentology; 38, 107-126. crombie m.k., arvidson r.e., sturchio nc, el alfy z., abu zeid k. (1997) age and isotopic constraints on pleistocene pluvial episodes in the western desert, egypt. palaeogeography, palaeoclimatology, palaeoecology; 130, 337-355. d'argenio b. (2001) from megabanks to travertinesthe indipendence of carbonate rock growthforms from scale and organismal templates trough time. in : earth system science. proceedings of the international school earth and planetary sciences. siena: 109-130. d ' ar g e n i o b., fe r r e r i v. (2004) travertines as self regulating carbonate systems. evolutionary trends and classification. földtani közlöny; 1 3 4 3 ( 2 ) , 209-218. d'argenio b., ferreri v., stanzione d., brancaccio l. & fe r r e r i m. (1983) i travertini di pontecagnano (campania). geomorfologia, sedimentologia, g e o c h i m i c a. bollett ino società geologica italiana, 102, 123-136. d ' ar g e n i o b., ie t t o a., ol d o w j.s. (1987) low angle normal faults in the picentini mountains, southern a p e n n i n e s. rendiconti società geologica italiana; 9; 113-125. ferreri v. (1985) criteri di analisi di facies e classificazione dei travertini pleistocenici dell'italia meridion a l e. rendiconti accademia scienze fisiche e matematiche; napoli, 52, 1-47. go l u b i c s., violante c., fe r r e r i v., and d ' ar g e n i o b . (1993) algal control and early diagenesis in quaternary travertine formation. (rocchetta a volturno, central apennines). special vol. boll. soc. pal. it.; 1, 231-247. he n n i n g g.j., gru∼n and br u n n a c k e r k. (1983) speleothems, travertines and palaeoclimates. quaternary research; 20, 1-29. he r m a n j.s., lo r a h m.m. (1988) calcite precipitation rates in the field : measurements and prediction for a travertine-depositing stream. geochimica et cosmochimca acta; 52, 2347-2355. ihlenfeld c., drysdale r.n., maas r., gagan m.k. norman m.d., webb j. (2003) climatic significance of seasonal trace element and stable isotope variations in a modern freshwater tufa. geochimica et cosmochimica acta; 13, 2341-2357. irion g., muller g. (1968) mineralogy, petrology and chemical composition of some calcareous tufa from the schwabische alb germany. in: muller g and friedman gm (eds.), present-day developments in carbonate sedimentology in central europe. springer-verlag, berlin heidelberg, 157-171. julia r. (1983) travertines. in: scholle p.a., bebou d.g., moore c.l., editors. carbonate depositional environments. aapg memoir; 33, 64-72. kano a., matsuoka j., kojo t., fujii h. (2003) origin of annual laminations in tufa deposits, southwest j a p a n. palaeogeography, palaeoclimatology, palaeoecology; 191, 243-262. lu g., zheng c., donahoe r.j., berry lyons w. (2000) controlling processes in a caco3 precipitating stream in huanglong natural scenic district, sichuan, china. journal of hydrology; 2 3 0, 34-54. martin-algarra a., martin-martin m., andreo b., julia r., go m e z c. (2003). sedimentary patterns in perched spring travertines near granada (spain) as indicators of the palaeohydrological and palaeoclimatological evolution of a karst massif. sedimentary geology; 161, 217-228. ma t s u o k a j., ka n o a., ob a t., wa t a n a b e t., sa k a i s . , seto k. (2001) seasonal variation of stable isotopic compositions recorded in a laminated tufa, sw japan. earth and planetary science letters; 192, 31-44. pe n t e c o s t a. (1995) the quaternary travertine deposits of europe and asia minor. quaternary science review; 14, 1005-1028. pe n t e c o s t a. (2004) t r a v e r t i n e. springerverlag, berlin, pp 1-431. soligo m., tuccimei p., barberi r., delitala m.c., miccad e i e., taddeucci a. (2002) u/th dating of freshwater travertine from middle velino valley (central italy): palaeoclimatic and geological implic a t i o n s . palaeogeography, palaeoclimatology, palaeoecology; 184, 147 -161. violante c., ferreri v., d'argenio b., golubic s. (1994) quaternary travertines at rocchetta a volturno (isernia, central italy). facies analysis and sedimentary model of an organogenic carbonate system. international association of sedimentologists; 15th regional meeting ischia, italy. pre-meeting fieldtrip guidebook; 5-22. ms. ricevuto il 11 marzo 2008 testo definitivo ricevuto il 29 marzo 2008 ms. received: march 11, 2008 final text received: march 29, 2008 97late pleistocene travertines ... microsoft word 00_indice_lm04.docx il quaternario it issn 039-3356 italian journal of quaternary sciences 24 (1), 2011 67-74 jaminia (jaminia) malatestae esu, 1988 (mollusca, gastropoda, enidae) from the middle and late pleistocene of central-southern italy. palaeoecological implications carmine d’amico1 & daniela esu2 1dipartimento stat, università degli studi del molise, pesche (isernia) 2dipartimento di scienze della terra, sapienza università di roma sapienza, igag cnr, roma corresponding author: d. esu <daniela.esu@uniroma1.it> abstract: d’amico c. & esu d., jaminia (jaminia) malatestae esu, 1988 (mollusca, gastropoda, enidae) from the middle and late pleistocene of central-southern italy. palaeoecological implications. jaminia (jaminia) malatestae is a fossil land gastropod of the family enidae. the species described by esu (1988) was dedicated to the quaternarist geologist and palaeontologist alberto malatesta who recognized, at the base of the ponte galeria formation (rome), the “blue-grey helicella bearing clays”, stratum typicum of the species, dated to the early middle pleistocene. j. (j.) malatestae is an endemic species of central-southern italy ranging from the early middle pleistocene to the late pleistocene. it was recovered from deposits with oligotypical assemblages of terrestrial gastropods and small mammals of cold-arid climate. during the middle pleistocene the species occurred in lazio, at fontignano and san cosimato (ponte galeria and aurelia formations, rome) in an oligotypic molluscan assemblage of cold climate and reworked in a politypic assemblage of temperate-warm climate respectively, and in abruzzo, at case picconetto (pescara) in a palaeosol of an alluvial deposit, associated with non-marine mollusc species typical of open environments and cold climate. in the middle and/or late pleistocene the species occurred in marche, at gola della rossa (ancona) in a cave-fill deposit with oligotypic molluscs of mountain grassland, and at polesio (ascoli piceno) in a sandy layer interbedded to gravels of the last glacial period, associated with gastropods of open environment and cold climate. in the late pleistocene (last gacial period) the species occurred in campania with oligotypic molluscan assemblage of cold climate from a loess deposit at telese (calore river valley) and from a sandy layer interbedded to gravels at tufino (naples). both the structure of the molluscan assemblages and the autoecology of the accompanying species suggest that j. (j.) malatestae populated open-dry palaeoenvironments in the central-southern italian peninsula during cold climatic periods of the middle and late pleistocene. its record in non-marine quaternary deposits of italy is an useful tool to infer reliable palaeoenvironmental and palaeoclimatical information. riassunto: d’amico c. & esu d., jaminia (jaminia) malatestae esu, 1988 (mollusca, gastropoda, enidae) del pleistocene medio e superiore dell’italia centro-meridionale. implicazioni paleoecologiche. jaminia (jaminia) malatestae è una specie di gasteropode terrestre della famiglia enidae conosciuta solo allo stato fossile. la specie, descritta da esu nel 1988 su materiale fossile proveniente dalle “argille ad helicella” del pleistocene medio-inferiore affioranti a ponte galeria (roma), è stata dedicata dall’autrice ad alberto malatesta, paleontologo e geologo del quaternario, che per primo individuò le “argille ad helicella”, stratum typicum della specie, alla base della formazione di ponte galeria. la distribuzione cronostratigrafica di j. (j.) malatestae, che risulta essere una specie endemica dell’italia centro-meridionale, va dal pleistocene medio inferiore al pleistocene superiore. generalmente si rinviene in associazioni malacofaunistiche e a micromammiferi indicatrici di ambienti aperti e condizioni climatiche fredde ed aride. nel pleistocene medio è nota nel lazio, a ponte galeria e, frammentaria, nella formazione aurelia (roma) come elemento non autoctono di un’associazione a molluschi terrestri e dulcicoli di clima temperatocaldo, in abruzzo (case picconetto, pescara) in un paleosuolo di un deposito alluvionale (età ca 0.48 ma) associata a molluschi terrestri di ambiente aperto e clima freddo. nelle marche è nota a gola della rossa (fabriano, ancona) in un’ associazione oligotipica a molluschi terrestri di prateria montana in depositi di riempimento di una grotta riferiti al “riss” finale o “würm” iniziale, e a polesio (ascoli piceno), in un deposito sabbioso intercalato a conglomerati riferiti all’ultimo glaciale, associata a specie terrestri di ambiente aperto e clima freddo. in campania è stata rinvenuta in associazioni oligotipiche indicatrici di clima freddo-arido in un deposito di loess appartenente al “terrazzo inferiore” del fiume calore (benevento), attribuito al pleistocene superiore (“würm”), e in sabbie intercalate a ghiaie riferite allo stadio isotopico 2 nei pressi di tufino (napoli) (valle del torrente clanio-acqualonga). il carattere generalmente oligotipico delle associazioni in cui j. (j.) malatestae è presente e l’autoecologia delle singole specie che l’accompagnano suggeriscono che questa specie popolava i paleoambienti privi di vegetazione arborea e relativamente aridi nell’italia centro-meridionale durante le fasi climatiche fredde del pleistocene medio e superiore, e ne fanno un elemento utile per significative indicazioni paleoambientali e paleoclimatiche. key words: jaminia (jaminia) malatestae, enidae, palaeoecology, palaeoclimate, pleistocene, italy. parole-chiave: jaminia (jaminia) malatestae, enidae, paleoecologia, paleoclima, pleistocene, italia. 1. introduction the distribution and abundance of terrestrial molluscan species are controlled by a number of interacting factors (barker, 2001; pfenninger & posada, 2002; davies, 2008). among these both temperature and relative humidity constraining the physiology and life cycle of terrestrial molluscs influence the differing geographical distribution of the species. each species has a thermal interval controlling its own physiological functions c. d’amico & d. esu 68 and outside the ranges the species cannot survive (moine et al., 2002 and references therein). these authors demonstrated that the mean temperature of the coldest month and annual thermal magnitude are the most important forcing parameters for the distribution of modern as well as quaternary land mollusc species. modern terrestrial molluscs are indices both of vegetation type and climate, permitting them to be grouped in ecological classes (boycott, 1934). quaternary terrestrial molluscan assemblages are mainly constituted by extant species which do not show significative changes in their ecological requirements at least from the middle pleistocene (gliozzi et al., 1997; rousseau et al., 2007). they can be gathered in ecological groups, as well as the living species, and used to infer general variations of environmental conditions related to the climatic cyclicity of quaternary glacial and interglacial periods. among land molluscan assemblages, woodland and steppe/grassland communities provide the major useful data on climatic fluctuations, indicating respectively warm intervals characterized by woodland expansion, and cold phases with decreased arboreal covering (sparks, 1961; id, 1964; ložek, 1964; id, 2000). a large number of studies that utilized the ecological patterns of terrestrial molluscs to infer quaternary palaeoclimatic signatures was published in past decades (for example, ložek, 1964; rousseau & wu, 1999; rousseau et al., 2000; wu et al., 2000). land molluscan assemblages were intensively studied in quaternary loess deposits of central and eastern europe, as well as in north america and in china, where their palaeoecological framework and related palaeoclimatic attributes have been used as useful biostratigraphical tools (rousseau, 2001). in the italian peninsula, at the beginning of the middle pleistocene, consequently to a general renewal probably related to the onset of the 100 ka orbital cyclicity, the non-marine molluscan assemblages became quite modern (esu & girotti, 1991; gliozzi et al., 1997) and strongly influenced by climatic change: the politypic assemblages are related to temperate and temperate-warm climatic phase (interglacial), while the oligotypic ones occurred during cold oscillations (glacial) (esu et al., 1989). in this work we give an overview of the geographical (fig. 1) and stratigraphical distribution of the terrestrial fossil species jaminia (jaminia) malatestae esu based on literature data published over the last 30 years, and highlight its palaeoecological meaning. the palaeoecology of each molluscan assemblage in which the species was recorded is analyzed. furthermore we report the unpublished occurrence of j. (j.) malatestae in an upper pleistocene deposit of the marche region. 2. systematic remarks phylum mollusca cuvier, 1797 class gastropoda cuvier, 1797 order stylommatophora schmitt, 1855 family enidae woodward, 1903 genus jaminia risso, 1826 subgenus jaminia risso, 1826 jaminia (jaminia) malatestae esu, 1988 fig. 2 1980 chondrula (jaminia) reversalis conato et al., p. 143 (non bielz). 1988 jaminia (jaminia) malatestae esu, p. 228, fig. 1. 1989 chondrula reversalis esu et al., p. 288 (non bielz). 1991 jaminia (jaminia) malatestae esu & girotti, p. 144. 1992 jaminia (jaminia) malatestae kotsakis et al., p. 336. 1997 jaminia malatestai gliozzi et al., p. 378. 1998 jaminia malatestae di vito et al., p. 281, fig. 9c. 2003 jaminia malatestai marcolini et al., p. 548, fig. 3a. description (esu, 1988). shell cylindro-conical, sinistral, of moderate size (height 10÷11.5 mm, diameter 4÷4.5 mm, occasionally 5 mm), with 7-71/2 rather flatsided whorls. apex large. sutures weak, faintly slanting. shell surface with weak, irregular, growth-lines well visible at sem. shell rather thick continuing with the same thickness into the mouth-edge. peristome neither expanded nor reflected, with a characteristic sinuous outer profile. mouth oval, always furnished with only one blunt parietal tooth more or less developed; sometimes a weak lengthened swelling is present along the columellar side. mouth-edge continuous bearing a little callus across the outer parietal area, always present in the specimens with preserved parietal peristome. the type material of j. (j.) malatestae was collected from the “blue-grey helicella bearing clays” (early middle pleistocene) at fontignano (rome) (figs. 1 and 3). at first it was ascribed to the species “chondrula (jaminia) reversalis (bielz, 1853)” by conato et al. (1980), then esu (1988), after direct comparison with specimens of the bielz’s species from eastern european quaternary non-marine deposits, stored in the geological institute of hungary (magiar allami földtani intézet) at budapest, formally classified the fontignano fossil record as j. (j.) malatestae dedicating it to the fig. 1 geographical distribution of j. (j.) malatestae. a) fontignano and san cosimato (rome); b) case picconetto (pescara); c) gola della rossa (ancona); d) polesio (ascoli piceno); e) telese (calore river valley, benevento); f) tufino (naples). distribuzione geografica di j. (j.) malatestae. a) fontignano e san cosimato (roma); b) case picconetto (pescara); c) gola della rossa (ancona); d) polesio (ascoli piceno); e) telese (valle del fiume calore, benevento); f) tufino (napoli). jaminia (jaminia) malatestae esu, 1988 (mollusca, gastropoda, enidae) … 69 quaternarist geologist and palaeontologist alberto malatesta, who first described the “blue-grey helicella bearing clays” in conato et al. (1980). gliozzi et al. (1997) reported the species as j. malatestai. nevertheless, according to the art. 31.1.1 of the international code of zoological nomenclature (iczn) (international commission on zoological nomenclature, 1999), the correct specific name is j. (j.) malatestae as firstly reported by esu (1988). 3. stratigraphical distribution and ecological framework j. (j.) malatestae ranges from the base of the early middle pleistocene1 to the late pleistocene. it is endemic of the italian peninsula and is recorded from few localities of central and southern italy (fig. 1). as the fossil status of the species, its ecological requirements were inferred from the autoecology of similar extant species, such as the congeneric jaminia (j.) quadridens (müller) to which it is often associate, and from the characteristics of the accompanying species. generally j. (j.) malatestae occurs in quaternary molluscan assemblages indicating grassland dried environments and cold climatic conditions. below we give an overview of the j. (j.) malatestae occurrences, focusing on the composition and the ecological framework of each related molluscan assemblage, according to ložek’s (1964) ecological classification of the central and eastern european quaternary non-marine molluscs (tab. 1). 3.1 lazio 3.1.1 fontignano (rome) the oldest occurrence of j. (j.) malatestae is registered in the lowermost middle pleistocene at fontignano (rome), in the “blue-grey helicella bearing clays” (fig. 3), a lower member of the ponte galeria formation in which conato et al. (1980) distinguished eight members, from the bottom: 1) river pebble and cobble conglomerates, 2) blue-grey helicella bearing clays, 3) beach conglomerates and bright yellow a. islandica sands,4) pebble gravels and sands with frequent crosslaminations, 5) venerupis senescens clays, 6) aeolian salmon sands, 7) lacustrine and marshy deposits, 8) “tufi grigi inferiori” (earthy and pisolitic tuffs). this stratigraphical succession registers the transitions from nonmarine to fully marine and non-marine conditions. more recently milli (1997) utilized a sequence-stratigraphy approach in refining the stratigraphy of the pleisto cene/holocene deposits of the roman area, distinguishing two composite third-order sequences, the monte mario sequence (mms) (early pleistocene) and the ponte galeria sequence (pgs) (middle-late pleistocene/holocene). the “blue-grey helicella bearing clays”, falling in the matuyama reversed palaeomagnetic epoch (marra et al., 1998), correspond to a lowstand system tract of the lower fourth-order sequence (pg1) of the pgs; it formed the inner portion of a coastal-barrier depositional system, laterally associated to a braid delta of a fluvial system evolving in a coastal plain with lowsinuosity braided channels (milli & palombo, 2005). this environmental interpretation is consistent with the terrestrial oligotypical molluscan assemblage rec tab. 1 ecological classes (ložek, 1964) of the mollusc species associated with jaminia (j.) malatestae. gruppi ecologici (ložek, 1964) cui appartengono le specie di molluschi associate a jaminia (j.) malatestae. 1 head et al. (2008; see also ogg et al., 2008) proposed to correlate the early-middle pleistocene boundary with the matuyama-brunhes palaeomagnetic chron boundary (about 773 ka) (mis 19). at present this proposal is informally accepted by the subcommission on quaternary stratigraphy (sqs) of the international commission on stratigraphy (ics), as reported in the “global chronostratigraphical correlation table for the last 2.7 ma v. 2009” (http://www.quaternary.stratigraphy.org.uk/ charts/; gibbard & cohen, 2008). nevertheless, in the present work, according to milli & palombo (2005), we utilize the ancient boundary of early-middle pleistocene, at transition mis 25 to mis 24. c. d’amico & d. esu 70 fig. 3 a) the “blue-grey helicella bearing clays” at fontignano (stratum typicum of j. (j.) malatestae); b) beach conglomerates and bright yellow a. islandica sands (photo: daniela esu). a) “argille grigio-azzurre ad helicella” a fontignano (stratum typicum di j. (j.) malatestae); b) conglomerati di spiaggia e sabbie giallo vivo ad a. islandica (foto: daniela esu). orded in the “helicella clays” (tab. 2). granaria frumentum (draparnaud), helicella itala (linné), and very probably j. (j.) malatestae, belong to the ecologic group 4s, including species that live in dry grassland (tabs 1 and 2). pupilla muscorum (linné) (5o) lives in dry exposed places or grassland, vallonia pulchella (müller) (5o) prefers slightly humid open grounds, trochulus hispidus (linné) (7m) is a widespread mesic species. g. frumentum, p. muscorum and t. hispidus are species more or less frequent in the loess molluscan assemblages of central europe (ložek, 1964). the oligotypy and the dominance of the species referred to the group 4s (fig. 4) are indicative of a steppe environment and cold-dry climatic conditions (esu, 1988; kotsakis et al., 1992). this is also confirmed by the record in the same deposit of two species of boreal arvicolids (rodents) of eastern europe, prolagurus pannonicus (kormos) and predicrostonix sp., belonging to the steppe lemming and collared lemming respectively (kotsakis et al., 1992). both the characteristics of the faunal assemblage and the fact that the “blue-grey helicella bearing clays” fall in reversed palaeomagnetic epoch led kotsakis et al. (1992) to attribute the inset of the sedimentary cycle of the ponte galeria formation immediately after the coldest peak of marine isotope stage (mis) 22. nevertheless, marra et al. (1998) referred the base of the ponte galeria formation to mis 20-19. 3.1.2 san cosimato (rome) only one fragmentary specimen (the last whorl with mouth), very probably reworked, was collected from the diatomitic muds of the aurelia formation (conato et al., 1980; pg6 of milli, 1997), in a rich politypic molluscan assemblage of about forty land and freshwater species characteristic of temperate-warm climate (esu, 1988; esu & girotti, 1991). based on stratigraphic evidences, radiometric dating, and vertebrate fossil record the aurelia formation was dated to middle pleistocene (mis 8-10) and the mollusc-bearing diatomitic layers can be referred to mis 9 likelihood (conato et al., 1980; gliozzi et al., 1997; milli, 1997; milli & palombo, 2005). 3.2 abruzzo 3.2.1 case picconetto (pescara) marcolini et al. (2003) reported j. (j.) malatestae in a silty-clayey palaeosol of a sedimentary succession, fig. 4 palaeoecological features of the analyzed molluscan assemblages. the ecological classes (ec, see tab. 1) and their relative frequency are reported for each assemblage (tab. 2). the percentages of the ecological classes for gola della rossa and telese assemblages are not available. carattere paleoecologico delle associazioni malacologiche analizzate. sono riportate le classi ecologiche (ec, vedi tab. 1) e le relative frequenze per ciascuna associazione (tab. 2). le percentuali delle classi ecologiche per le associazioni di gola della rossa e telese non sono disponibili. jaminia (jaminia) malatestae esu, 1988 (mollusca, gastropoda, enidae) … 71 cropping out at case picconetto (pescara), interpreted as a distal part of an old alluvial fan deposit. the two palaeosols recorded in the succession, one of which, the uppermost, holding j. (j.) malatestae, are related to a local stasis in the alluvial fan accretion. a tephra layer dated 0.48 ± 0.04 ma (apatite fission track dating) lies above the palaeosol containing j. (j.) malatestae. the molluscan assemblage consists mainly of terrestrial taxa (tab. 2). only two freshwater species, gyraulus (armiger) crista (linné) and g. (g.) albus (müller), occur reaching less than 0.3% of the assemblage. the land species typical of open ground (5o) are dominant, followed by open dry grassland taxa (4s) (fig. 4). the mesic species (7m) are represented by a discrete number of specimens of vitrea contracta (westerlund). the strictly forest (1w) and hygrophilous taxa (8h) are very scarce, represented by sphyradium cf. s. doliolum (bruguière) and vertigo angustior jeffreys respectively, which, according to ložek (1964), are warm-climate species. the molluscs are associated to an oligotypical micromammal assemblage with dominant arvicolids, such as microtus cf. m. arvalis (pallas), m. (terricola) gr. savii (de selys longschamps), followed by murids, such as apodemus gr. sylvaticus-flavicollis, and insectivores (crocidura sp.), indicative of open environment and mediterranean-type climate (marcolini et al., 2003). together, molluscs and small mammals indicate open ground environment and cold, but not severe, climatic conditions. the radiometric dating, the results of chemical analysis carried out on the tephra layer, and the palaeoenvironmental indications suggested by molluscs and small mammals, led marcolini et al. (2003) to correlate the case picconetto succession with mis 14. 3.3 marche 3.3.1 gola della rossa (ancona) esu et al. (1990) recorded j. (j.) malatestae from a cave-fill deposit (grotta del vento, gola della rossa, ancona) in an oligotypical molluscan assemblage (tab. 2). candidula spadae (calcara) and clausilia (clausilia) rugosa pinii westerlund, prefer open woodland, but locally can live in open or semi-open habitats [2w(s)]. at present, they have apennine distribution being common in the high mountain zone (manganelli et al., 1995; cianfanelli, 2009. j. (j.) quadridens (4s), chondrina avenacea (bruguière) (4sf) and p. muscorum (5o) populate dry grassland or open grounds. small mammals and one reptile are associated with the land molluscs: sorex antinorii bonaparte, s. minutus linné, rhinolophus ferrumequinum (schreber), myotis dasycneme (boie), pliomys lenki cfr. relictus chaline, m. arvalis, chionomys nivalis (martins), apodemus cfr. sylvaticus (linné), and hierophis viridiflavus (lacépède) (revised by t. kotsakis). both molluscs and mammals indicate open and rather dry mountain palaeoenvironment, and cold climatic conditions. based on small mammals the cave-fill deposit of gola della rossa can be attributed to the late middle pleistocene (mis 6) or early late pleistocene (mis 4) (esu et al., 1990). 3.3.2 polesio (ascoli piceno) we report the unpublished occurrence of j. (j.) malatestae in upper pleistocene non-marine deposits at polesio (ascoli piceno). in a recent work buccolini et al. (2010) (see also gentili et al., 1998), analizing the geomorphological evolution of the last 20 ka in the high hill sector (6001100 m a.s.l.) of mt. ascensione area (southern marche), described upper pleistocene stratified slope deposits made up of alternating sandy and gravel layers. the type stratigraphic sequence, about 30 m thick, crops out at porchiano and polesio (fig. 5). in the sequence, several palaeosols 20-50 cm thick, located at different heights with respect to the bottom of the deposits, occur. buccolini et al. (2010) constrain chronologically these deposits with four 14c ams dating of charcoal fragments present in 4 palaeosols, two located 30 cm and 1 m above the bottom of the porchiano sequence, and two 3 m below the top of the polesio sequence. at porchiano the palaeosols are dated > 51000 yr bp and 41640 ± 1260 yr bp, respectively, at polesio 23230 ± 170 yr bp and 22680 ± 170 yr bp. in a sandy layer of the polesio sequence, close to the dated palaeosols, an oligotypical assemblage of land molluscs rich in specimens was recovered. it is constituted by dominating (about 43%) taxa of steppe c. d’amico & d. esu 72 fig. 5 upper pleistocene stratified slope deposits of the mt. ascensione area (southern marche). schematic type stratigraphic sequences: porchiano (a) and polesio (b); c) stratigraphic section at polesio (from buccolini et al., 2010). depositi stratificati di versante del pleistocene superiore nell'area del monte dell'ascensione (marche meridionali). sequenze stratigrafiche tipo: porchiano (a) e polesio (b); c) sezione stratigrafica presso polesio (da buccolini et al., 2010). environment (4s) (fig. 4) represented by pupilla triplicata (studer), truncatellina callicratis (scacchi), j. (j.) quadridens and j. (j.) malatestae (tab. 2), followed (about 29%) by open land species (group 5o). c. spadae, fairly abundant (about 24%), prefers open woodland, but locally can live in semi-open to open habitats. the ecological framework of the molluscan assemblage leads us to infer open palaeoenvironment and cold climatic conditions. 3.4 campania 3.4.1 calore river valley (benevento) malatesta (1959) reported the presence of a land molluscan assemblage in a loess layer interbed ded to tufitic and detrital fluvial deposits of a sedimentary succession located near the mineral source named ‘a uolla on the left side of the calore river (telese, benevento). at present, this deposits, related by the author to the “würm”, are no more cropping out. the molluscan assemblage is constituted only by four species, j. (j.) malatestae (4s), v. pulchella (5o), p. muscorum (5o) and helicella sp. (tab. 2), indicating open dry environment and cold climate (esu, 1988; esu & girotti, 1991). 3.4.2 tufino (naples) di vito et al. (1998) reported j. (j.) malatestae in the clanio-acqualonga valley (naples). non-marine deposits mainly constituted by carbonate gravels crop out in a quarry near tufino town. a sandy palaeosol, 80 cm thick, interbedded with gravels yielded a rich, but oligotypical land molluscan assemblage (tab. 2). the species of dry grassland environment (4s) dominate (fig. 4). cernuella neglecta (draparnaud) represented by more than 500 specimens, p. muscorum of dry exposed places and v. pulchella of more or less damp open habitats (5o) are well represented. the ecological requirements of the molluscan fauna indicate steppe environment and cold climatic conditions. the deposit containing the molluscs was referred to the last glacial period (mis 2). 4. conclusion so far j. (j.) malatestae was found only in the seven quaternary non-marine deposits of central and southern italy listed above, ranging from the early middle pleistocene to late pleistocene. in all the deposits j. (j.) malatestae is accompanied by the dominance of steppe species (4s) and open land species (5o) (tab. 2 and fig. 4), except at san cosimato where it was reworked. the strictly forest species (1w) and the hygrophilous ones (8h), represented only at case picconetto by sphyradium cf. s. doliolum and v. angustior respectively, are very scarce (tab 2 and fig. 4). at fontignano, case picconetto and gola della rossa, small mammals were recovered with the land molluscs. the ecological and climatic requirements of the mammal species confirm the palaeoenvironmental interpretation of open-dry habitats and cold climate inferred by the molluscs. the palaeoecological interpretation of the molluscan assemblages containing j. (j.) malatestae is in agreement with the chronological attribution of the related deposits, correlated with the middle and late pleistocene marine isotope stages mis 22, 14, 6 (or 4) and 2, which, except mis 14, correspond to major or minor glacial events occurred at global scale from the estabilishing of the 100 ka cyclicity, at about 900 ka bp (ehlers & gibbard, 2007) (fig. 6). acknowledgements many thanks are due to dr. g. cilla for the help in the field-research at polesio (marche), and g. manganelli and g. zanchetta for the useful advices. jaminia (jaminia) malatestae esu, 1988 (mollusca, gastropoda, enidae) … 73 fig. 6 relations among middle-late pleistocene glacial events, marine isotope stages and the occurrences of jaminia (j.) malatestae in middle-upper pleistocene non-marine deposits of central and southern italy. relazione tra eventi glaciali del pleistocene medio e superiore, stadi isotopici marini dell'ossigeno e presenza di jaminia (j.) malatestae nei depositi continentali medio e tardo pleistocenici dell'italia centro-meridionale. references barker g.m. (ed.) (2001) the biology of terrestrial molluscs cabi publishing, new york, xiv + 558 pp. boycott a.e. (1934) the habitat of land mollusca in britain journ. ecol., 22, pp. 1-38. buccolini m., gentili b., materazzi m. & piacentini t. (2010) late quaternary geomorphological evolu tion and erosion rates in the clayey peri-adriatic belt (central italy) geomorphology, 116, pp. 145-161. cianfanelli s. (2009) i molluschi della provincia di pistoia: le specie da tutelare e quelle da combattere quaderni del padule di fucecchio, centro di ricerca, documentazione e promozione del padule di fucecchio, 6, pp. 1-111. conato v., esu d., malatesta a. & zarlenga f. (1980) new data on the pleistocene of rome quaternaria, 22, pp. 131-176. davies p. (2008) snails: archaeology and landscape change oxbow books, oxford, xvii + 199 pp. di vito m., sulpizio r. & zanchetta g. (1998) i depositi ghiaiosi della valle dei torrenti clanio e acqualonga (campania centro-orientale): significato stratigrafico e ricostruzione paleoambientale il quaternario, 11, pp. 273-286. ehlers j. & gibbard p.l. (2007) glaciations/ overview encyclopedia of quaternary science, elsevier, pp. 1023-1031. esu d. (1988) jaminia (jaminia) malatestae n.sp. from the italian pleistocene (pulmonata: enidae) arch. moll., 119, pp. 227-233. esu d. & girotti o. (1991) late pliocene and pleistocene assemblages of continental molluscs in italy. a survey il quaternario, 4, pp.137-150. esu d., girotti o. & kotsakis t. (1989) oligotipia nei vertebrati e nei molluschi continentali fossili atti iii simposio di ecologia e paleoecologia delle comunità bentoniche, catania, 1985, pp. 285-298. c. d’amico & d. esu 74 esu d., galdenzi s. & kotsakis t. (1990) molluschi e microvertebrati del deposito pleistocenico della grotta del vento (gola della rossa ancona). nota preliminare in: galdenzi s. & menichetti m. (eds) il carsismo della gola di frasassi mem. ist. it. spel., 4, s. ii, pp. 193-198. gentili b., materazzi m., pambianchi g. & scalella g. (1998) i depositi di versante del monte dell’ascensione (marche meridionali, italia) geogr. fis. dinam. quat., 21, pp. 205-214. gibbard p. & cohen k.m. (2008) global chronostratigraphical correlation table for the last 2.7 million years episodes, 31, pp. 243-247. giraudi c. (2004) the apennine glaciations in italy in: ehlers j. & gibbard p.l. (eds) quaternary glaciations extent and chronology. part i: europe develop. quatern. sci., 2, pp. 215-223. gliozzi e., abbazzi l., argenti p., azzaroli a., caloi l., capasso barbato l., di stefano g., esu d., ficcarelli g., girotti o., kotsakis t., masini f., mazza p., mezzabotta c., palombo m.r., petronio c., rook l., sala b., sardella r., zanalda e. & torre d. (1997) biochronology of selected mammals, molluscs and ostracods from the middle pliocene to the late pleistocene in italy. the state of the art riv. ital. paleont. strat., 103, pp. 369-388. head m.j., pillans b. & farquhar s.a. (2008) the early-middle pleistocene transition: characterization and a proposed guide for the defining boundary episodes, 31, pp. 234-238. international commission on zoological nomenclature (1999) international code of zoological nomenclature. fourth edition international trust for zoological nomenclature, london, 306 pp. kotsakis t., esu d. & girotti o. (1992) a post-villafranchian cold event in central italy testified by continental molluscs and rodents boll. soc. geol. it., 111, pp. 335-340. ložek v. (1964) quartärmollusken der tschechoslowakei rozpr. ústř. úst. geol., 31, pp. 1-374. ložek v. (2000) palaeoecology of quaternary mollusca antropozoikum, 24, pp. 35-59. malatesta a. (1959) note di geologia e morfologia sulla valle caudina e sulla valle del f. calore boll. serv. geol. it., 80, pp. 255-260. manganelli g., bodon m., favilli l. & giusti f. (1995) gastropoda pulmonata. in: minelli, a., ruffo, s., la posta, s. (eds.) checklist delle specie della fauna italiana. calderini, bologna, 16, 60 pp. marcolini f., bigazzi g., bonadonna f.p., centamore e., cioni r. & zanchetta g. (2003) tephrochronology and tephrostratigraphy of two pleistocene continental fossiliferous successions from central italy. j. quaternary sci., 18, pp. 545-556. marra f., florindo f. & karner d.b. (1998) paleomagnetism and geochronology of early middle pleistocene depositional sequence near rome: comparison with the deep-sea δ18o record. earth planet. sci. lett., 159, pp. 147-164. milli s. (1997) depositional setting and high-frequency sequence of the middle–upper pleistocene to holocene deposits of the roman basin geol. romana, 33, pp. 99–136. milli s. & palombo m.r. (2005) the high-resolution sequence stratigraphy and the mammal fossil record: a test in the middle-upper pleistocene deposits of the roman basin (latium, italy) quaternary int., 126-128, pp. 251-270. moine o., rousseau d.-d., jolly d. & vianey-liaud m. (2002) paleoclimatic reconstruction using mutual climatic range on terrestrial mollusks quaternary res., 57, pp. 162-172. muttoni g., carcano c., garzanti e., ghielmi m., piccin a., pini r., rogledi s. & sciunnach d. (2003) onset of major pleistocene glaciations in the alps geology, 31, pp. 989-992. ogg j.g., ogg g. & gradstein f.m. (2008) the concise geologic time scale cambridge university press, vii + 177 pp. pfenninger m. & posada d. (2002) phylogeographic history of the land snail candidula unifasciata (helicellinae, stylommatophora): fragmentation, corridor migration, and secondary contact evolution, 56, pp. 1776-1788. rousseau d.d. (2001) loess biostratigraphy: new advances and approaches in mollusk studies earth sci. rev., 54, pp. 157-171. rousseau d.d. & wu n. (1999) mollusk record of monsoon variability during the l2-s2 cycle in the luochuan loess sequence, china quaternary res., 52, pp. 286-292. rousseau d.d., wu n. & guo z. (2000) the terrestrial mollusks as new indices of the asian paleomonsoons in the chinese loess plateau global planet. change, 26, pp. 199-206. rousseau d. d., derbyshire e., antoine p. & hatté c. (2007) loess records/europe encyclopedia of quaternary science, elsevier, pp. 1440-1456. sparks o. (1961) the ecological interpretation of quaternary non-marine mollusca proc. linn. soc. lond., 172 (1959-1960), pp. 71-80. sparks o. (1964) non-marine mollusca and quaternary ecology j. anim. ecol., 33, pp. 87-98. wu n., rousseau d.d., & liu x. (2000) response of mollusk assemblages from luochuan loess section to orbital forcing since the last 250 ka chinese sci. bull., 45(17), pp. 1617-1622. ms. ricevuto il 3/06/2010 testo definitivo ricevuto il 14/08/2010 ms. received: june 3, 2010 final text received: august 14, 2010 microsoft word 00_indice_lm04.docx il quaternario it issn 039-3356 italian journal of quaternary sciences 24 (1), 2011 103-112 stephanorhinus kirchbergensis (jäger, 1839) from the middle pleistocene deposit of riano (rome, central italy) luca pandolfi dipartimento scienze della terra, università di roma sapienza, roma correspondent author: <l.pandolfi@yahoo.it> abstract: pandolfi l., stephanorhinus kirchbergensis (jäger, 1839) from the middle pleistocene deposit of riano (rome, central italy). in this work the rhinoceros remains discovered in the site of riano are analyzed. the remains are preserved in museum of paleontology of university “sapienza” of rome and they have been recovered in a diatomaceous deposit together with remains of elephas antiquus, cervus elaphus rianensis and dama clactoniana. the faunal assemblage of riano can be correlated with torre in pietra faunal unit on the base of fossil mammal fauna and stratigraphical data. rhinoceros remains belong to only one individual and consist of various postcranial elements. morphological and morphometrical characters of the remains are comparable with eurasian rhinoceros s. kirchbergensis. this species has been rarely recorded, although the distribution range has been relatively wide. s. kirchbergensis has been discovered in a large part of europe and in the early and middle pleistocene deposits of central asia, where the species has probably origin. riano is one of the few european localities where post-cranial remains of s. kirchbergensis are reported. riassunto: pandolfi l., stephanorhinus kirchbergensis (jäger, 1839) dal deposito del pleistocene medio di riano (roma, italia centrale). in questo lavoro vengono analizzati i resti di rinoceronte rinvenuti nel bacino diatomitico di riano e conservati presso il museo di paleontologia dell’ università “sapienza” di roma. la fauna a grandi mammiferi, rinvenuta negli stessi depositi da cui proviene il rinoceronte, è composta da elephas antiquus, cervus elaphus rianensis e dama clactoniana; il sito è correlabile, per composizione faunistica e stratigrafia, con l’unità faunistica di torre in pietra. i resti di rinoceronte, composti da diverse parti dello scheletro post-craniale e appartenenti ad un unico individuo, presentano caratteristiche morfologiche e morfometriche comparabili con la specie euroasiatica s. kirchbergensis. questa specie, nonostante occupasse un vasto areale, è relativamente rara e probabilmente ha origine in asia centrale, da dove provengono le segnalazioni più antiche riferite al pleistocene inferiore. la presenza di s. kirchbergensis nel sito di riano rappresenta una delle poche in europa in cui vengono descritti resti dello scheletro post-craniale di questa specie, prevalentemente conosciuta sulla base di denti isolati. key words: stephanorhinus kirchbergensis, middle pleistocene, riano. parole-chiave: stephanorhinus kirchbergensis, pleistocene medio, riano. 1. introduction the site of riano is situated 20 km north of rome and is characterized by tufaceous-diatomitic formation. this last is lying on the “yellow vacuolized tuff” of the pleistocene tufaceous series of “vulcano sabatino” (ambrosetti et al., 1969, 1972; accordi & maccagno, 1962; bonadonna & bigazzi, 1969). in the past century, from the diatomaceous levels, well-preserved and almost complete vertebrate skeletons have been discovered. among the others, the fossil fauna is represented by elephas antiquus falconer & cautley, cervus elaphus rianensis leonardi & petronio, dama clactoniana (falconer), several fishes, amphibians and reptiles (maccagno, 1962; accordi & maccagno, 1962; mastrorilli, 1965; leonardi & petronio, 1974; caloi et al., 1980). the fossil flora is well represented by several forest assemblages (follieri, 1958a; 1958b; 1962) that allow to well-reconstruct the climatic conditions near riano during the middle pleistocene. the landscape around the site was characterized by a dense forest, with a remarkable biodiversity compared to coeval records of vegetation in central and northern europe. the modern analog of this landscape may be found in areas with over 2000 mm mean annual precipitation, favouring the development of such a dense forest. in particular, three forest phases are recognised: a mixed oak forest at the basis, followed by a period with dominant pterocarya kunth, and by a final phase with a progressive increase of abies miller and fagus linnaeus pollen and the decrease of that of pterocarya (ambrosetti & bonadonna, 1967; follieri, 1962; follieri & magri, 2001). ambrosetti et al. (1972) and bonadonna & bigazzi (1969) proposed, for the diatomaceous deposit of riano, the formation name ‘rianian’ to cover the late middle pleistocene in the stratigraphical scheme for the tyrrhenian margin in central italy. on the basis of stratigraphical relationships and faunal characteristics, malatesta (1978) regarded these deposits as strictly representing the continental facies equivalent to the fluvio-lacustrine-brackish-marine sediments that form the aurelia formation and, according to caloi et al. (1998), this deposit can be correlated with torre in pietra faunal unit (sensu gliozzi et al., 1997). l. pandolfi 104 2. materials and methods the nomenclature used in this work was set by fortelius et al., (1993). also, according to groves (1983) the pleistocene european rhinoceroses show little similarity with the genus dicerorhinus gloger and they are ascribed to genus stephanorhinus kretzoi, as previously used by several authors (heissing, 1973, 1981, 1989; cerdeño, 1993, 1995, 1998; prothero et al., 1986; inter alios). rhinoceros remains found in the site of riano are preserved in the museum of paleontology of “sapienza” university of roma (mpur). some of the remains are unpublished while some of them are previously ascribed to dicerorhinus cf. mercki kaup (leonardi & petronio, 1974; guérin, 1980). later, the rhinoceros of riano has been reported in literature as dicerorhinus cf. hemitoechus falconer, stephanorhinus sp., stephanorhinus cf. hemitoechus (caloi et al., 1980, caloi & palombo, 1994; palombo et al., 2002). ). the remains analyzed have been found in the ’70ties of the past century in the cave of diatomaceous earth of valle dell’inferno (riano) (petronio, pers. com.). in the same cave, in the ’60ties of the past century, the skeletons of cervus elaphus rianensis have been discovered. the rhinoceros remains belong to the same individual and some of them have been found articulated. also, the rhinoceros lacks of the cranial portion and preserves several post-cranial elements among the os coxae, femurs, calcaneum, talus. the most of post-cranial elements are damaged or deformed by characteristics of the fossiliferous site, therefore some morphometrical characters can not be taken into account. morphological characters considered are those listed as diagnostics by several authors, including guérin (1980), fortelius et al. (1993), lacombat (2005). when possible, the morphometric methods are based on the works of guérin (1980), mazza (1988), fortelius et al. (1993), lacombat (2005). 3. specimens studied and comparations the rhinoceros remains from riano are represented by several elements of post-cranial skeleton and fragments of bones. the principal elements of the skeleton are reported and described below. 3.1 vertebrae the vertebral column is represented by several thoracic and lumbar vertebrae (mpur 7/1-7/16) in a different state of preservation (fig. 1). some of them are articulated with other vertebrae and ribs (mpur 7/217/25). also, among the vertebrae is present the proximal portion of an atlas, very damaged. due to the deformation and damage of the remains, no morphological characters or morphometric values can be taken into account. 3.2 scapulae (mpur 7/54) two scapulae are present, one right and one left, articulated with the ribs. the scapulae are compressed latero-medially and are very damaged (fig. 1). the left scapula preserved only the proximal portion, while, the right one preserved the proximal portion (depth of the proximal portion > 212 mm) and the spine. no diagnostic character is present in the preserved portions. 3.3 humeri two humeri are present; one of them preserved only the diaphysis (mpur 7/69) and a portion of the proximal articular surface (mpur s.n.). the other one preserved the diaphysis and a very damaged proximal epiphysis (mpur 7/56) (fig. 1). the dimensions of the diaphysis (breadth = about 65 mm; depth = > 65 mm) seem not to be helpful to distinguish between the different rhinoceros species. in fact, the dimensional ranges of the diaphysis of the european pleistocene rhinoceroses are quite similar (cfr. guérin, 1980). the proximal articular surface is almost intact and have a circular outline. the approximate dimensions (breadth = > 80 mm; depth = > 90 mm) allow to exclude that it can be ascribed to s. etruscus falconer (cfr. fortelius et al., 1993). 3.4 sacrum (mpur 7/20) the sacrum (maximal breadth = about 167 mm; maximal length = > 165 mm) is articulated with some lumbar vertebrae (mpur 7/17-7/19) (fig. 1). no morphological or morphometrical study has been done on the sacrum of european pleistocene rhinoceroses. considering that, the comparison with other specimens is very difficult. 3.5 os coxae several fragmentary portions of the os coxae are present (mpur 7/59-7/65). also, the left os coxae is almost intact (mpur 7/57) and the articular surface of the right os coxae is present (mpur 7/58). the acetabulum is relatively broad, deep and sub-elliptical, compressed dorsally (fig. 1). this shape seems not to be present in s. etruscus, s. hundsheimensis toula and s. hemitoechus (cfr. lacombat, 2005); it is more similar to s. kirchbergensis jäger from taubach (cfr. portis, 1878). also, posteriorly, the acetabulum is separated into two articular lips; a dorsal and a ventral one. the dorsal lip is inclined posterior-ventrally and is much wider and longer that the ventral one (fig. 1). these characters allow to distinguish this bone from those of s. etruscus, s. hundsheimensis and s. hemitoechus (cfr. lacombat, 2005), and seem to be present in s. kirchbergensis from taubach (cfr. portis, 1878). also, unlike s. hemitoechus, in the os coxae from riano the pit of acetabulum is well-evident (cfr. lacombat, 2005). the dimensions of the acetabulum are much larger than s. etruscus from upper valdarno. the value of the maximal length of the acetabulum is much greater than s. hemitoechus and it is more similar to the maximal values of s. hundsheimensis (tab. 1). also, the values of the diaphysis of the ilium and the height of the acetabulum appear relatively large in the specimens of riano (tab. 1). 3.6 femurs the two distal epiphysis of the femurs (mpur 7/66; mpur 7/68) and a damaged portion of the right proximal epiphysis are preserved (mpur 7/70) (fig. 2). the proximal articular surface is partially damaged in the medial portion and seems to be slightly compressed dorso-ventrally (fig. 2). in proximal view, it seems to be much developed and much compressed latero-medially compared with s. hundsheimensis from mauer (from fortelius et al., 1993) and ponte molle. the articular surfaces of the distal epiphysis of the femurs, in anterior stephanorhinus kirchbergensis (jäger, 1839) from the middle pleistocene deposit of riano … 105 fig. 1 rhinoceros remains from riano: 1) scapula, lateral view; 2) humerus, posterior view; 3) os coxae, a-dorsal view, b-lateral view of articular surface; 4) sacrum, ventral view; 5) thoracic vertebrae, right lateral view. the bar is of about 2 cm. resti di rinoceronte di riano: 1) scapola, visione laterale; 2) omero, visione posteriore; 3) bacino, a-visione dorsale, b-visione laterale della superficie articolare; 4) sacro, visione ventrale; 5) vertebre toraciche, visione laterale destra. la barra è di circa 2 cm. fig. 2 rhinoceros remains from riano: 1) femur, proximal epiphysis, proximal view; 2) femur, distal epiphysis, a-anterior-distal view, b-posterior view; 3) patella, lateral view; 4) tibia, proximal view; 5) talus, anterior view; 6) calcaneum, a-medial view, b-distal view; 7) metapodial bone articulated with first phalanx, lateral view. the bar is of about 2 cm. resti di rinoceronte di riano: 1) femore, epifisi prossimale, visione prossimale; 2) femore, epifisi distale, a-visione anteriore, b-visione posteriore; 3) rotula, visione laterale; 4) tibia, visione prossimale; 5) astragalo, visione anteriore; 6) calcagno, a-visione mediale, bvisione distale; 7) metapodiale in connessione anatomica con la prima falange, visione laterale. la barra è di circa 2 cm. l. pandolfi 106 tab. 1 comparative dimensions of os coxae from riano and of s. etruscus (s. etru.) (data from mazza, 1988), s. hemitoechus (s. hem.) and s. hundsheimensis (s. hund.) from isernia (data from lacombat, 2005). la = outer length of the acetabulum; lar = inner length of the acetabulum; lar = inner width of the acetabulum; lo = length of the foramen obturatum; bsi = breadth of the shaft of the ilium; his = height of the shaft of the ilium; ha = height of the acetabulum; ll = lateral length; ca = about. dimensioni comparative del bacino di riano e di s. etruscus (s. etru.) (dati da mazza, 1988), s. hemitoechus (s. hem.) e s. hundsheimensis (s. hund.) di isernia (dati da lacombat, 2005). la = lunghezza esterna dell’acetabolo; lar = lunghezza interna dell’acetabolo; lar = larghezza interna dell’acetabolo; lo = lunghezza del foramen obturatum; bsi = ampiezza della diafisi dell’ilium; his = altezza della diafisi dell’ilium; ha = altezza dell’acetabolo; ll = lunghezza laterale; ca = circa. tab. 2 comparative dimensions of femurs from riano and of s. etruscus (s. etru.), s. hemitoechus (s .hem.), s. hundsheimensis (s. hund.) and s. kirchbergensis (s. kirch.) (1 = data from fortelius et al., 1993; 2 = data from lacombat, 2005; 3 = data from kahlke, 1977). dtap = breadth of the proximal epiphysis; dapap = depth of the proximal epiphysis; dtd = breadth of the distal epiphysis; dapdm = medial depth of the distal epiphysis; dapdl = lateral depth of the distal epiphysis; dttr = breadth of the distal trochlea; dtcon = breadth of the posterior condyles; dtfc = breadth of the intercondyloid fossa. dimensioni comparative dei femori di riano e di s. etruscus (s. etru.), s. hemitoechus (s. hem.), s. hundsheimensis (s. hund.) e s. kirchbergensis (s. kirch.) (1 = dati da fortelius et al., 1993; 2 = dati da lacombat, 2005; 3 = dati da kahlke, 1977). dtap = diametro trasversale dell’epifisi prossimale; dapap = spessore dell’epifisi prossimale; dtd = diametro trasversale dell’epifisi distale; dapdm = spessore mediale dell’epifisi distale; dapdl = spessore laterale dell’epifisi distale; dttr = diametro trasversale della troclea distale; dtcon = diametro trasversale dei condili posteriori; dtfc = diametro trasversale della fossa intercondilea. stephanorhinus kirchbergensis (jäger, 1839) from the middle pleistocene deposit of riano … 107 distal view, are undamaged and welldeveloped (fig. 2). the trochlea is clearly asymmetric and the medial lip is much larger and developed than the lateral one. the trochlear trough is broad and deep. in medial view, the surface of the bone is broad and the tuberosity is well-evident and massive. it is situated slightly higher than the lateral one. in lateral view, the surface of the bone is less broad than the medial one and the tuberosity is much rounded (fig. 2). this morphology can be observable in the distal epiphysis of s. kirchbergensis from taubach (cfr. kahlke, 1977) and mosbach (cfr. fortelius et al., 1993) and it is different from those of the other species of the stephanorhinus genre. these last have a different development and shape of the medial and lateral tuberosities and of the articular surfaces (guérin, 1980; fortelius et al., 1993; lacombat, 2005). in posterior view, the condyles are well-developed and rounded; the intercondyloid fossa is strong, broad and deep (fig. 2). the medial condyle is much broader than the lateral one; this last is postero-laterally inclined. even these characters seem to be distinctive of s. kirchbergensis and allow to distinguish it from the other species of the stephanorhinus genre (guérin, 1980; fortelius et al., 1993; lacombat, 2005). at last, the dimensions of the femurs of riano are relatively large. they are comparable with the maximal values of s. hemitoechus and the values of s. kirchbergensis (tab. 2; tab. 7). 3.7 patellae (mpur 7/72; mpur 7/71) two patellae are preserved, one right and one left, differently damaged (fig. 2). in posterior view, two articular surfaces are present, a medial one, broad and concave, and a lateral one, less broad and concave than the former. the two articular surfaces are well-separated by a saddle. the dimensions of the bones are relatively large if compared with those of s. etruscus, s. hundsheimensis and s. hemitoechus reported by fortelius et al. (1993) and lacombat (2003) (tab. 3); in particular, the dtmax is much greater. this last character is peculiar of s. kirchbergensis (guérin, 1980) (tab. 7). 3.8 tibia (mpur 7/73) only one tibia is present. this last is very damaged and preserved the proximal epiphysis and a portion of the diaphysis. the tibia is massive, the anterior tuberosity is damaged and deformed, the tibial spine is quite salient and the interspine fossa is relatively broad (fig. 2). the lateral rim of the tibial spine is higher than the medial tab. 3 comparative dimensions of patellae from riano and of s. etruscus (s. etru.), s. hemitoechus (s. hem) s. hundsheimensis (s. hund.) and s. kirchbergensis (s. kirch.) (1 = data from fortelius et al., 1993; 2 = data from lacombat, 2005; 3 = data from kahlke, 1977). lmax = maximal lenght; la = articular lenght; dt max = maximal breadth; dta = articular breadth; dapmax = maximal depth. dimensioni comparative delle rotule di riano e of s. etruscus (s. etru.), s. hemitoechus (s. hem) s. hundsheimensis (s. hund.) e s. kirchbergensis (s. kirch.) (1 = dati da fortelius et al., 1993; 2 = dati da lacombat, 2005; 3 = dati da kahlke, 1977). lmax = lunghezza massima; la = lunghezza articolare; dt max = diametro trasversale massimo; dta = diametro trasversale articolare; dapmax = diametro anteroposteriore massimo. tab. 4 comparative dimensions of talus from riano and of s. etruscus (s. etru.), s. hemitoechus (s .hem.) s. hundsheimensis (s. hund.) and s. kirchbergensis (s. kirch.) (1 = data from fortelius et al., 1993; 2 = data from lacombat, 2005; 3 = data from kahlke, 1977). dtmax = maximal breadth; dapl = lateral depth; htrl = height of the lateral trochlea; hl = lateral height. dimensioni comparative dell’astragalo di riano e di s. etruscus (s. etru.), s. hemitoechus (s. hem.), s. hundsheimensis (s. hund.) e s. kirchbergensis (s. kirch.) (1 = dati da fortelius et al., 1993; 2 = dati da lacombat, 2005; 3 = dati da kahlke, 1977). dtmax = diametro trasversale massimo; dapl = diametro antero-posteriore laterale; htrl = altezza della troclea laterale; hl = altezza laterale. l. pandolfi 108 one. the tibial fossa, in dorsal view, seems to be relatively wide; however, this last character may have been accentuated by the deformation. the medial articular surface of the proximal epiphysis is more anteroposteriorly elongated than the lateral one. the state of preservation of the tibia does not allow to carry out an exhaustive morphometrical work. the relative dimension of the transversal diameter of the proximal epiphysis (dtp = > 129 mm) seems to be larger than s. etruscus and s. hundsheimensis (respectively dtp = 87÷110 mm and dtp = 111,5÷119 mm in fortelius et al., 1993; respectively dtp = 102÷115 mm and dtp = 103÷123,5 mm in guérin, 1980) and is closer to maximal values of s. hemitoechus (dtp = 101÷137,5 mm in guérin, 1980) and to the values of s. kirchbergensis reported by guérin (1980) (dtp = 136 mm) and kahlke (1977) (dtp = 122,5). 3.9 talus (mpur 7/76) the talus (fig. 2) is relatively damaged; in anterior view, the trochlea lacks of the medial portion; in lateral view, the articular surface is relatively wide and is posteriorly limited by a slight depression. in medial view, the distal tuberosity is well-developed and is situated in the anterior-distal margin of the medial face, unlike s. hemitoechus (guérin, 1980; lacombat, 2005). in posterior view, the proximo-lateral articular surface is welldeveloped, concave and sub-quadrangular in shape; it is elongated in the latero-distal side with a smaller articular facet. the mesio-distal articular surface have subtrapezoidal shape; it is well-separated from the proximolateral one and is relatively damaged. the maximal transverse diameter is greater than s. etruscus and s. hundsheimensis. the dimensions of the bone are comparable with the maximal values of s. hemitoechus and fall in the variation range of s. kirchbergensis (tab. 4; tab. 7). 3.10 calcaneum (mpur 7/75) in lateral view, the calcaneum (fig. 2) is slightly antero-posteriorly compressed; on the whole, the bone is massive and dimensionally large. the tuber calcanei is relatively large and high; it has an anteroposterior development similar to the beak. this last character allow to distinguish this bone from those of s. etruscus and s. hundsheimensis (guérin, 1973; 1980; lacombat, 2005). the sustentaculum talii is about perpendicular to the axis of the bone and it is slightly damaged in the medial portion. in antero-distal view, the articular surfaces are well-evident. the upper lateral articular surface has rounded shape; the articular surface on the sustentaculum talii has a clear outline and has sub-circular shape. these last articular surfaces are clearly wellseparated between them. the lower articular surface is slightly damaged and more higher than long. the articular surface with the cuboid is flat and antero-posteriorly elon gated. all these morphological characters are comparable with s. kirchbergensis and allow to distinguish from s. hemitoechus. in this last species the articular surfaces with the talus are not well-separated between them and the lower articular surface is more longer than high (cfr. guérin, 1973; 1980; kahlke, 1977). also, the dimensions of the calcaneum are relatively great and are comparable with the values of s. kirchbergensis (tab. 5; tab. 7). 3.11 cuboids (mpur s.n.) the cuboids, one right and one left, are incomplete and differently damaged. the anterior face of the bone is sub-trapezoidal in shape and the lateral side is more higher than the medial one. the lower margin of the anterior face is about straight, while the upper margin is clearly oblique. in proximal view, the articular surface seems to be flat in the anterior-lateral side and oblique in the medial side. no other morphological character is observable and the few characters present do not allow to distinguish among the species (cfr. fortelius et al., 1993; lacombat, 2005). the dimensions of the cuboids from riano are comparable with the values of s. kirchbergensis and the maximal values of s. hemitoechus (tab. 6). 3.12 great cuneiform (mpur s.n.) only one cuneiform is preserved. it is very damaged and deformed. in lateral view, two articular surfaces are visible. the proximo-medial articular surface has subtriangular shape, while the distal one is elongated. due to the deformation of the bone, no other morphological or morphometrical character is recognizable. tab. 5 comparative dimensions of calcaneum from riano and of s. etruscus (s. etru.), s. hemitoechus (s .hem.), s. hundsheimensis (s. hund.) and s. kirchbergensis (s. kirch.) (1 = data from fortelius et al., 1993; 2 = data from lacombat, 2005; 3 = data from kahlke, 1975; 1977). hmax = maximal height; dts = breadth of the tuber calcanei; daps = depth of the tuber calcanei; dtmp = minimum posterior breadth; dtst = breadth of the sustentaculum talii; dapb = depth of the beak. dimensioni comparative del calcagno di riano e di s. etruscus (s. etru.), s. hemitoechus (s. hem.), s. hundsheimensis (s. hund.) e s. kirchbergensis (s. kirch.) (1 = dati da fortelius et al., 1993; 2 = dati da lacombat, 2005; 3 = dati da kahlke, 1975; 1977). hmax = altezza massima; dts = diametro trasversale del tuber calcanei; daps = diametro antero-posteriore del tuber calcanei; dtmp = diametro trasversale minimo posteriore; dtst = diametro trasversale del sustentaculum talii; dapb = diametro antero posteriore del becco. stephanorhinus kirchbergensis (jäger, 1839) from the middle pleistocene deposit of riano … 109 tab. 6 comparative dimensions of cuboids from riano and of s. etruscus (s. etru.), s. hemitoechus (s .hem.), s. hundsheimensis (s. hund.) and s. kirchbergensis (s. kirch.) (0 = data from guérin, 1980; 1 = data from fortelius et al., 1993; 2 = data from lacombat, 2005). h ant. = anterior height; l = breadth. dimensioni comparative dei cuboidi di riano e di s. etruscus (s. etru.), s. hemitoechus (s. hem.), s. hundsheimensis (s. hund.) e s. kirchbergensis (s. kirch.) (0 = dati da guérin, 1980; 1 = dati da fortelius et al., 1993; 2 = dati da lacombat, 2005). h ant. = altezza anteriore; l = larghezza. 3.13 metapodial bone (mpur s.n.) very fragmentary metapodial bone is preserved. it consists of a distal epiphysis articulated with the first and second phalanges (fig. 2). no morphological or morphometrical character are recognizable. 4. discussion and conclusions even if partially damaged, the rhinoceros remains from riano preserve some characters, such as the articular surfaces, which allow an accurate analysis. in particular, the shape and size of the articular surfaces and tuberosities of the femurs, the characters of the os coxae and the morphology of the calcaneum of the rhinoceros from riano are comparable with s. kirchbergensis (cfr. guérin, 1973; 1980; fortelius et al., 1993). moreover, the size of the remains fall into the variation range know for s. kirchbergensis (cfr. kahlke, 1977; guérin, 1980; fortelius et al., 1993). s. kirchbergensis seems to be a relatively rare species, although it is reported in most of europe and asia (guérin, 1980; tong, 2001; lacombat, 2005; billia, 2008; billia & petronio, 2009). this rarity could be related with the ethology of the species; probably, it was present in the area with groups of few individuals. however, it can be assumed that the species living in ecological niche unfavourable for its fossilization (loose, 1975). in this regards, the species seems to be typical of forest environments; this hypothesis is supported by the brachydont teeth of the species and by the remains of flora and fauna that have been discovered with this species (guérin, 1980). recently, s. kirchbergensis has been found in sites of southern china, 2000 m above sea level, that correspond to temperate deciduous and coniferous forest (tong & wu, 2009). the fossil flora of riano, discovered with the rhinoceros remains, bear out the hypothesis that species could be typical of forest environments. this fact could be explain the relatively absence or rarity of the species in southern italy, in the iberian peninsula and in north africa, unlike to the coeval european species s. hemitoechus (guérin, 1980; cerdeño, 1990; billia & petronio, 2009). the phylogenetics of s. kirchbergensis is still unresolved. this species is directly connected to larterotherium megarhinus (de christol) by würst (1922), staesche (1941) and guérin (1980), even if the evolutionary connections between the two species are not clear much. however, s. kirchbergensis seems to has origin in central asia. in fact, it is reported in early pleistocene sites of china and kazakhstan (khisarova, 1963; dong et al. 2000; tong & moigne, 2000; tong, 2001; billia & petronio, 2009; tong & wu, 2009). later s. kirchbergensis is present in the middle pleistocene deposits of russia and eastern europe (czyżewska, 1962; borsuk-bialyńicka & jakubowski, 1972; billia & shpansky, 2005; billia, 2008). the species may be evolved in central asia from a common ancestor of the evolutionary lineage that led to s. hemitoechus in europe. later, it would spread westward during the middle pleistocene. in this regards, an exhaustive analysis of mio-pliocene asian rhinoceros remains would confirm this hypothesis. in italy, the oldest remains ascribed to s. kirchbergensis are those discovered in the middle pleistocene sites of valdemino (nocchi & sala, 1997) and ponte molle (capasso barbato et al., 1998; billia & petronio, 2009), both correlable with isernia fu (sensu gliozzi et al., 1997). also, the species is reported in few sites of late middle pleistocene of northern and central italy and it seems to be absent in the second part of late pleistocene (petronio et al., 2007). however, the most part of the remains ascribed to this species consist of isolated teeth. the remains of riano are, instead, one of the rare record in europe of s. kirchbergensis based on post-cranial elements belonging to a single individual. l. pandolfi 110 tab. 7 comparative dimensions of femurs, patellae, talus and calcaneum from riano and of s. hemitoechus (s .hem.), s. hundsheimensis (s. hund.) and s. kirchbergensis (s. kirch.) reported by guérin (1980). dimensioni comparative dei femori, delle rotule, dell’astragalo e del calcagno di riano e di s. hemitoechus (s .hem.), s. hundsheimensis (s. hund.) e s. kirchbergensis (s. kirch.) dati da guérin (1980). acknowledgements thanks to prof. c. petronio for critical review and support. also thanks to two anonymous reviewers, prof. h.w. tong, prof. m. follieri, prof. d. magri, dr. r. manni and sig. l. riti. references accordi b. & maccagno a. m. (1962) researches in the pleistocene of riano (rome) geol. romana, 1, pp. 25-32. ambrosetti p. & bonadonna f.p. (1967) revisione dei dati sul plio-pleistocene di roma atti acc. gioenia sc. nat. catania, 18, pp. 33-72. ambrosetti p., bonadonna f. p. & tolomeo l. (1969) studi sul pleistocene del lazio. vi una nuova data per la campagna romana boll. soc. geo. it., 88, pp. 3-10. ambrosetti p., azzaroli a., bonadonna f.p. & follieri m. (1972) a scheme of pleistocene chronology for the tyrrhenian side of central italy boll. soc. geo. it., 91, pp. 169-184. billia e.m.e. (2008) revision of the fossil material attributed to stephanorhinus kirchbergensis (jäger, 1839) (mammalia, rhinocerotidae) preserved in the museum collections of the russian federation quat. int., 179, pp. 25-37. billia e.m.e. & shpansky a.v. (2005) stephanorhinus kirchbergensis (jäger, 1839) (mammalia, rhinoce rotidae) from the middle pleistocene levels of the ob’ river at krasny yar (tomsk region, western siberia) deinsea, 11, pp. 75-82. billia e.m.e. & petronio c. (2009) selected records of stephanorhinus kirchbergensis (jäger, 1839) (mammalia, rhinocerotidae) in italy boll. soc. paleont. it., 48 (1), pp. 21-32. bonadonna f. p. & bigazzi f. (1969) studi sul pleistocene del lazio. età di un livello tufaceo del bacino diatomitico di riano stabilita con il metodo delle tracce di fissione boll. soc. geo. it., 89, pp. 463-473. borsuk-bialynicka m. & jakubowski g. (1972) the skull of dicerorhinus mercki (jäger) from warsaw prace paleozoologiczne, prace museum ziemi, 20, pp. 187-207. caloi l. & palombo m.r. (1994) le mammalofaune del pleistocene inferiore nell’italia centrale studi geologici camerti, vol. spec. 1994 (b) , pp. 487-501. caloi l., palombo m. r., petronio c. (1980) le principali mammalofaune del pleistocene della campagna romana paleont. strat. .evol., 1, pp. 73-79. caloi l., palombo m. r. & zarlenga f. (1998) late middle pleistocene mammals faunas of latium; stratigraphy and environment quat. int., 47/48, pp. 77-86. capasso barbato l., di stefano g., petronio c. & sardella r. (1998) pleistocene mammal faunas from ponte molle quat. int., 47/48, pp. 73-75. cerdeño e. (1990) stephanorhinus hemitoechus (falc.) (rhinocerotidae,mammalia) del pleistoceno medio stephanorhinus kirchbergensis (jäger, 1839) from the middle pleistocene deposit of riano … 111 y superior de españa estudios geologicos, 46, pp. 465-479. cerdeño e. (1993) remarks on the spanish plio-pleistocene stephanorhinus etruscus (rhinocerotidae) c. r. acad. sci. paris, 317, pp.1363-1367. cerdeño e. (1995) changes inwestern european rhinocerotidae related to climatic variations pal., pal., pal., 114, pp.325-338. cerdeño e. (1998) diversity and evolutionary trends of the family rhinocerotidae (perissodactyla) pal., pal., pal., 141, pp.13-34. czyżewska t. (1962) uzębienie górnej szczęki dicerorhinus mercki (jäger) ze szczęśliwic kolo warszawy acta palaeont. polonica, 7 (1-2), pp. 223234. dong w., jin c., xu q., liu j., tong h. & zheng, l. (2000) a comparative analysis on the mammalian faunas associated with homo erectus in china acta anthrop. sin., 19, pp. 246-256. follieri m. (1958a) notizie preliminari su una flora fossile a pterocarya rinvenuta nelle diatomiti di riano ann. bot. 26 (1) , pp. 1-3. follieri m. (1958b) la foresta colchica fossile di riano romano. i. studio dei fossili vegetali macroscopici ann. bot, 26 (1), pp. 129-142. follieri m. (1962) la foresta colchica fossile di riano romano, ii analisi polliniche ann. bot, 27 (2), pp. 245-280. follieri m. & magri d. (2001) middle and upper pleistocene natural environment in the roman area: climate, vegetation and landscape 1st international congress “the world of elephants”. (pp. 4347). fortelius m., mazza p. & sala b. (1993) stephanorhinus (mammalia, rhinocerotidae) of the western european pleistocene, with a special revision of stephanorhinus etruscus (falconer, 1868) paleont. it., 80, pp. 63-155. gliozzi e., abbazzi l., argenti p., azzaroli a., caloi l., capasso barbato l., di stefano g., esu d., ficcarelli g., girotti o., kotsakis t., masini f., mazza p., mezzabotta c., palombo m-r., petronio c., rook l., sala b., sardella r., zanalda e. & torre d. (1997) biochrnology of selected mammals, molluscs and ostracods from the middle pliocene to the late plesitocene in italy. the state of the art riv. it. paleont. strat., 103 (3), pp. 369-388. groves c.-p. (1983) phylogeny of the living species of rhinoceros zeitschr. f. zoo. systematik u. evolutionsforsch, 21, pp., pp.293-313. guérin c. (1973) les trois espèces de rhinocéros (mammalia, perissodactyla) du gisement pléistocène moyen des abimes de la fage a noailles (corrèze) nouv. arch. mus. hist. nat. lyon, 11, pp. 55-84. guérin c. (1980) les rhinocéros (mammalia, perissodactyla) du miocène terminal au pléistocène supérieur en europe occidentale. comparaison avec les espèces actuelles doc. lab. géol. lyon, 79 (1-3), pp. 1-1185. heissig k. (1973) die unterfamilien und tribus der rezenten und fossilen rhinocerotidae (mammalia) säugetierkundl. mitt., 21, pp.25-30. heissig k. (1981) probleme bei der cladistischen analyse einer gruppe mit wenigen eindeutigen apomorphien: rhinocerotidae paläontol. z. 55, pp.117-123. heissig k. (1989) rhinocerotidae in: prothero d.r, schoch, r.m (eds.), the evolution of perissodactyls oxford university press, pp.399-417. kahlke h.-d. (1975) die rhinoceotiden-reste aus den travertinen von weimar-ehringsdorf abh. zentr. geol. inst., 23, pp. 337-397. kahlke h.-d. (1977) die rhinoceotiden-reste aus den travertinen von taubach quätarpaläontologie, 2, pp. 305-359. khisarova g.d. (1963) iskopaemye kosti mlekopitayushchikh iz koshkurganskogo grifona, yuzhny kazakhstan [mammal osteological fossil remains from the koshkurgan locality, southern kazakhstan] materialy po istorii fauny i flory kazakhstana, 4, pp. 42-75. an kazssr, izd-vo nauka kazssr, alma-ata [in russian]. lacombat f. (2005) les rhinocéros fossiles des sites préhistoriques de l’europe méditerranéenne et du massif central. paléontologie et implications biochronologiques bar international series, 1419, pp. 1-175. leonardi g. & petronio c. (1974) i cervi pleistocenici del bacino diatomitico di riano (roma) atti acc. naz. lincei, mem. cl. sc. fis. mat. nat., iia, 12 (3), 8, pp. 101-208. loose h.k. (1975) pleistocene rhinocerotidae of western europe with reference to the recent two-horned species of africa and s.e. asia scripta geologica, 33, pp.1-59. maccagno a.m. (1962) gli elefanti di riano (roma) geol. romana, 1, pp.33-131. malatesta a. (1978) torre in pietra. roma quaternaria, 20, pp. 203-577. mastrorilli v.i. (1965) i fossili quaternari del bacino diatomitico di riano presso roma nella collezione del museo civico di scienze naturali ‘g. doria’ in genova atti ist. geol. univ. genova, 3 (1), pp. 242. mazza p. (1988) the tuscan early pleistocene rhinoceros dicerorhinus etruscus paleont. it., 75, pp.1-87. nocchi g. & sala b. (1997) the fossil rabbit from valdemino cave (borgio verezzi, savona) in the context of western europe oryctolagini of quaternary palaeovertebrata, 26 (1-4), pp.167–187. palombo m.r., azanza b.& alberdi m.t. (2000-2002) italian mammal biochronology from latest miocene to middle pleistocene: a multivariate approach geol. romana, 36, pp. 335-368. petronio c., di canzio e. & salari l. (2007) the late pleistocene and holocene mammals in italy: new biochronological and paleoenvironmental data palaeontographia abt. a, 279, pp.147-157. portis a. (1878) über die osteologie von rhinoceros merckii jäger und über die diluviale. säugetierfauna von taubach bei weimar palaeontographica, 25 (4), pp. 141-162. prothero d.-r., manning e. & hanson c.-b. (1986) the phylogeny of rhinocerotoidea zool. jour. lin. soc., 87, pp.341-366. staesche k. (1941) nashörner der gattung dicerorhinus aus diluvium württembergs abh. reichsst. bodenf., 200, pp. 1-148. l. pandolfi 112 tong h. (2001) rhinocerotids in china systematics and material analysis geobios, 34 (5), pp. 585591. tong h. & moigne a.m. (2000) quaternary rhinoceros of china acta anthropologica sinica, supplement to 19, pp. 257-263. tong h.w. & wu x.z. (2009) stephanorhinus kirchbergensis (rhinocerotidae, mammalia) from the rhino cave in shennongjia, hubei chinese science bulletin, 55 (12), pp. 1157-1168. wüst e. (1922) beiträge zur kenntnis der diluvialen nashörner europas centralbl. f. min. geol. u pal., 20, pp. 641-656; 21, pp. 680-688. ms. ricevuto il 13/05/2010 testo definitivo ricevuto il 4/08/2010 ms. received: may 13, 2010 final text received: august 4, 2010 sess 1_160211.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 persististrombus latus-bearing deposits south of isola di capo rizzuto, calabria (southern italy) valentina alice bracchi 1, ronald nalin 2 & daniela basso 1 1 university of milano-bicocca, italy 2 geoscience research institute, ca, usa corresponding author: v.a. bracchi <v.bracchi@campus.unimib.it> abstract: bracchi v.a., nalin r. & basso d., persististrombus latus-bearing deposits south of isola di capo rizzuto, calabria (southern italy). (it issn 0349-3356, 2011) during a research fieldtrip in the crotone peninsula an area characterized by a flight of well developed pleistocene marine terraces a level rich of in situ persististrombus latus gmelin 1791 (= strombus bubonius lamarck 1822) has been discovered in a quarry south of isola di capo rizzuto (calabria, southern italy) at ~ 46 m above sea level. p. latus is a shallow warm-water marine gastropod belonging to the strombidae family. presently, it lives along the tropical coasts of africa but entered the mediterranean through the gibraltar strait in the late pleistocene as part of the socalled senegalese fauna. p. latus found as fossil in the mediterranean is commonly considered a marker of marine isotope stage (mis) 5.5. this is the first documented record of a level containing multiple specimens of in situ p. latus in the crotone terraces, allowing direct correlation to the tyrrhenian stage or mis 5.5. the bio-calcarenite and associated p. latus specimens have been collected in order to petrographically analyze the sediment and describe the benthic association. riassunto: bracchi v.a., nalin r. & basso d., persististrombus latus in depositi di terrazzo marino a sud di isola di capo rizzuto, calabria (italia). (it issn 0349-3356, 2011) durante una campagna di ricerca nella penisola di crotone, area caratterizzata dalla presenza di terrazzi marini ben sviluppati, è stato rinvenuto un livello ricco di persististrombus latus gmelin 1791(= strombus bubonius lamarck 1822) in situ, in una cava posta a sud di isola di capo rizzuto (calabria, italia) a circa 46 m di altitudine. p. latus è un gasteropode di acque calde e poco profonde della famiglia strombidae. e’ tuttora vivente lungo le coste tropicali africane, ma si introdusse nel mar mediterraneo attraverso lo stretto di gibilterra nel tardo pleistocene, come membro della fauna detta senegalese. p. latus viene comunemente considerato un marker dello stadio isotopico marino (mis) 5.5. questo è il primo ritrovamento documentato di un livello contenente molteplici esemplari in situ di p. latus nell’area dei terrazzi crotonesi, permettendo una correlazione diretta con lo stadio tirreniano o mis 5.5. la bio-calcarenite associata ed esemplari di p. latus sono stati campionati al fine di analizzare petrograficamente il sedimento e descrivere l’associazione bentica. keywords: persististrombus latus, pleistocene, tyrrhenian stage, mis 5.5, calabria, crotone peninsula parole chiave: persististrombus latus, pleistocene, tirreniano, mis 5.5, calabria, penisola di crotone. during a fieldtrip in the crotone peninsula, aimed at the study of the biogenic deposits of the le castella and capo colonna marine terraces, multiple specimens of persististrombus latus gmelin 1791 (= strombus bubonius lamarck 1822) were discovered in a quarry located south of isola di capo rizzuto (calabria, italy). p. latus is a shallow warm-water marine mollusc of the strombidae family, presently living exclusively on the tropical coasts of africa. however, p. latus is commonly found as fossil in late pleistocene deposits of the mediterranean region, being a representative of the so-called ‘senegalese’ fauna which entered the mediterranean through the gibraltar strait in the mid-late pleistocene (gignoux, 1913; issel, 1914; selli, 1962; ruggieri et al., 1968; issar a., 1969; bonfiglio, 1972; 1981; di grande & scamarda, 1973; herm et al., 1975; fleisch et al., 1981; porta & martinell, 1981; cataliotti valdina, 1984; bossio et al., 1986; hearty & dai pra, 1986; caldara, 1987; flores et al., 1987; gliozzi, 1987; spanò, 1991; 1993; causs et al., 1993; lario et al., 1993; sivan et al., 1994; kéraudren et al., 2000; jedoui et al., 2003; zazo et al., 2003; federici & pappalardo, 2006). p. latus has historically become a characteristic marker of mis 5.5 and the tyrrhenian (the last faunal stage of the pleistocene in mediterranean area) (gignoux, 1913; issel 1914; cita & castradori, 1995) and is commonly used to correlate and chronologically constrain deposits of raised beaches (e.g. hearty, 1986; ferranti et al., 2006). the crotone peninsula is characterized by the presence of well developed pleistocene marine terraces, generated by the interplay of sea-level change and progressive uplift of the calabrian arc. these terraces were first reported by cortese (1895) and were subsequently studied by several authors from a geomorphic, stratigraphic, 23 25 24 sedimentologic, paleontologic and geochronologic point of view (gignoux, 1913; ruggieri 1948; 1951; selli, 1962; gueremy, 1972; belluomini et al., 1987; gliozzi, 1987; cosentino et al., 1989; palmentola et al., 1990; mauz & hassler, 2000; zecchin et al., 2004; 2010; nalin et al., 2006; 2007; nalin & massari, 2009). selli (1962) was the first to report the occurrence of p. latus in one of the terraces, at an elevation between 45 and 55 m above sea level (asl), but did not provide details of the finding. gliozzi (1987) reported the occurrence of very rare p. latus specimens on dislocated blocks from the area of campolongo, north of le castella village, 80 m asl, and identified a unique s. leonardo di cutro-campolongo-isola di capo rizzuto terrace correlated to mis 5.5. palmentola et al. (1990) located patches of a marine terrace between capo cimiti (15 m asl) and la mazzotta (84 m asl) with a typical warm water fauna correlated to mis 5.5, but found only one specimen of p. latus in this terrace on a dislocated block. in recent restoration works of the aragonese castle of le castella, a block of calcarenite containing numerous p. latus specimens was included in the stone pavement of the platform that protects the southern portion of the castle from wave washout. reasoning that the block should have been extracted from a nearby quarry, a careful search of recently active quarries led to the finding of a level preserving several in situ p. latus specimens (5 specimens in a surface exposure area of ~ 2 m2) and other five specimens in piled blocks extracted from the quarry deposits. the quarry is located south of the isola di capo rizzuto village, in a morphological terrace (between 41 and 57 m asl) that is part of the s. leonardo-campolongo-isola di capo rizzuto terrace of gliozzi (1987). (gps position of the surface with in situ p. latus: n38 56.566 e17 04.444; approximate elevation: 46 m asl). the p. latus specimens are sparsely distributed on the exposed surface, and are larger than 5 cm in size. they are contained in a monotonous succession of cross-stratified medium to coarse calcarenite, showing gentle clinostratification towards the south. other bioclasts include large disarticulated bivalve valves (most likely glycimeris sp.) this level is the first documented occurrence of in situ multiple specimens of p. latus in the area of isola di capo rizzuto and allows correlating these outcrops with mis 5.5. the recorded elevation is concordant with selli (1962) and intermediate with respect to the other reports on dislocated blocks (gliozzi, 1987; palmentola et al., 1990). the latter discrepancy could be ascribed to the patchy and tectonically disturbed distribution of the mis 5.5 deposits in the crotone peninsula area (gliozzi, 1987; cosentino et al., 1989; zecchin et al., 2004). references belluomini g., gliozzi e., ruggieri g., branca m. & delitala l. (1987) first dates on the terraces crotone peninsula (calabria, southern italy). boll. soc. geol. it., 7, 249-254. bonfiglio l. (1972) il tirreniano di bovetto e ravagnese presso reggio calabria. quaternaria, 6, 137-148. bonfiglio l. (1981) terrazzi marini e depositi continentali quaternari di taormina (sicilia). quaternaria, 13, 81-102. bossio a., mazzanti r., mazzei r, nencini c., pasquinucci m, salvatorini g. & sanesi g. (1986) schéma stratigraphique et morphologique du pleistocene et de l’holocene de la toscana côtière a l’aide de la paléontologie, de la palethnnologie, de la pédologie, de l’archéologie et de la cartographie prégéodésique. l’anthropologie, 90(1), 3-8. caldara m. (1987) la sezione tirreniana di ponte del re (castellaneta marina, taranto): analisi paleoecologica. atti soc. tosc. sci. nat. mem., a 93, 129-163. cataliotti valdina j. (1984) addition à la faune malacologique du tyrrhenien de monastir (tunisie). geobios, 17(4), 501-508. causs c., goy j.l., zazo c. & hillari-marcel c., (1993) potentiel chronologique (th/u) de faune pleistocenes mediterranéennes; examples des terrasses marines des regions de murcia et alicante (sud est de l'espagne). geodin. acta, 6(2), 121-134. cita m.b. & castradori d. (1995) rapporto sul workshop “marine sections from the gulf of taranto (southern italy) usable as potential stratotype for the gssp in the lower , middle and upper pleistocene. boll. soc. geol. it., 114, 319-336. cortese e. (1895) descrizione geologica della calabria. mem desc. carta. geol. it., 9, 1-310. cosentino d., gliozzi e. & salvini f. (1989) brittle deformations in upper pleistocene deposits of the crotone peninsula, calabria, southern italy. tectonophysics, 163, 205-217. di grande a. & scamarda g. (1987) segnalazione di livelli a strombus bubonius lamarck nei dintorni di augusta (siracusa). bol. acc. gioenia sci. nat. catania, serie 4, 11(9-10), 157-179. federici p.r. & pappalardo m. (2006) evidence of marine isotope stage 5.5 highstand in liguria (italy) and its tectonic significance. quat. intern., 145-146, 68 -77. ferranti l., antonioli, f., mauz b., amorosi a., dai pra g., mastronuzzi g., monaco c., orrù p., pappalardo m., radtke u., renda p., romano p., sansò p. & verrubbi v. (2006) – markers of the last interglacial sea-level high stand along the coast of italy: tectonic implications. quat. intern., 145-146, 3054. fleisch h., comati j. & elouard p. (1981) poursuite et synthèse des etudes sur le gisement a strombus bubonius lmk (tyrrhénièn) de naasme (liban). quaternaria, 23, 51-79. flores j.a. & porta j. (1987) paleontology and v.a. bracchi, r. nalin & d. basso 25 ms. received: testo ricevuto il taphonomy of the tyrrhenian in the neighbourhood of alicante. trab. neog.-cuat, 10, 109-139. gignoux m. (1913) les formations marines pliocènes et quaternaires de l’italie du sud et de la sicilie. ann. univ. lyon, 36, 693 pp. gliozzi e. (1987) i terrazzi marini del pleistocene superiore della penisola di crotone (calabria). geol. rom., 26,17-79. gueremy p. (1972) la calabrie central et septentrionale. guide d’excursion géomorphologique. trav. inst. géogr. reims, 10, 1-28. hearty p.j. (1986) an inventory of last interglacial (sl.) age deposits from the mediterranean basin: a study in isoleucine epimerization and u/th dating. zeit. geom., su band 62, 51–69 hearty, p.j. & dai pra, g., 1986. aminostratigraphy of quaternary marine deposits in the lazio region of central italy. zeit. geom., su band 62, 131–140 herm d., karray r., paskoff r. & sanlaville p. (1975) sur deux depôts à strombus bubonius du golfe de tunis. bull. soc. geol. fr., 17(1) supplément 1, 21-22. issar a. (1969) the tyrrhénian of israel, lebanon and cyprus. earth-science, 18(3-4), 162. issel a. (1914) lembi fossiliferi quaternari recenti osservati nella sardegna meridionale dal prof. d. lovisato. atti. acc. lincei rend. fis. serie 5, 23, 759-770. jedoui y., reyss j.l., kallel n., montacer m., ismail h.b. & davaud e. (2003) u-series evidence of two high last interglacial sea levels in southeastern tunisia. quat. sci. rev.,22, 343-351. kéraudren b., dalongeville r., bernier p. & renault -miskovsky v.c.j. (2000) le pléistocène supérieur marin (tyrrhénien) en crète nord-orientale (grèce). géomorphologie, 6(3), 177-190. lario j., somoza l., goy j.l., hoyos m., silva p.g. & hernandez molina f. (1993) los episodios marinos cuaternarios de la costa de malaga (espana). rev. soc. geol. esp., 6, 41-46. mauz b. & hassler u. (2000) luminescence chronology of late pleistocene raised beaches on southern italy: new data on relative sea-level changes. mar. geol., 170, 187-203. nalin r., basso d. & massari f. (2006) pleistocene coralline algal build-ups (coralligène du plateau) and associated bioclastic deposits in the sedimentary cover of cutro marine terrace (calabria, southern italy). in: pedley h.m. and carannante g. (eds.) cool-water carbonates: depositional system and palaeoenvironmental controls. geol. soc. lond. spec. pub., 255, 11-22. nalin r., massari, f. & zecchin, m. (2007) superimposed cycles of composite marine terraces: the example of cutro terrace (calabria, southern italy). j. sed. res., 77, 340-354. nalin r. & massari f. (2009) facies and stratigraphic anatomy of a temperate carbonate sequence (capo colonna terrace, late pleistocene, southern italy). j. sed. res., 79, 210-225. palmentola g., carobene l., mastronuzzi g. & sansò p. (1990) i terrazzi marini pleistocenici della penisola di crotone (calabria). geog. fis. din. quat., 13, 75-80. porta j. & martinell j. (1981) el tyrrheniense catalan, sintesis y nuevas aportaciones. departemento de paleoentologia, universitat de barcelona, 70. ruggieri g. (1948) il terrazzo marino presiciliano della penisola di crotone. giorn. geol. serie 3, 20, 39-62. ruggieri g. (1951) età e faune di un terrazzo marino sulla costa ionica della calabria. giorn. geol. serie 2, 23, 19-168 ruggieri g., buccheri g. & rendina m. (1968) segnalazione di tirreniano fossilifero a trapani. riv. miner. sic., 112-114, 1-4. selli r. (1962) le quaternaire marin du versant adriatique-jonien de la péninsule italienne. quaternaria, 6, 391-413. sivan d., gvirtzman g., kaufman a. & sess e. (1994) the yasaf member; a strombus-bearing unit on the coast of galilee representing tyrrhenian event in the mediterranean. annual meeeting: israel geological society vol. 1994, 106. spanò c. (1991) la faune bethique des niveaux a strombus bubonius de is mesas-cala mosca (sardaigne méridionale, italie). as. esp. est. cuat., viii reun. naz. valencia 19pp. spanò c. (1993) signification bioécologique et bathymétrique des paléocommunautés pleistoceniques des côtes méridionales de la sardaigne. est. cuat., 27-42. zazo c., goy j. l., dabrio c. j., bardajì t., hillairemarcel c., ghaleb b., gonzalez-delgado j. & soler v. (2003) pleistocene raised marine terraces of the spanish mediterranean and atlantic coasts : records of coastal uplift, sea-level highstands and climate changes. mar. geol., 194, 103-133. zecchin m., nalin r. & roda c. (2004) raised pleistocene marine terraces of the crotone peninsula (calabria, southern italy): facies analysis and organization of their deposits. sed. geol., 172, 165185. zecchin m., caffau m., civile d. & roda c. (2010) anatomy of a late pleistocene clinoformal sedimentary body (le castella, calabria, southern italy); a case of prograding spit system? sed. geol., 223, 291-309. persististrombus latus-bearing deposits south ... january 14, 2011 14 gennaio 2011 microsoft word 00_indice_lm04.docx il quaternario it issn 039-3356 italian journal of quaternary sciences 24 (1), 2011 93-101 a pathologic straight-tusked elephant female from neumark nord (germany) federica marano1 & maria rita palombo1,2 1università degli studi di roma sapienza, roma 2università degli studi di roma sapienza, igag cnr, roma corresponding author: f. marano <federica.marano86@gmail.com> abstract: marano f. & palombo m.r., a pathologic straight-tusked elephant female from neumark nord. the elephant bones collected during more than ten years (1985-1996) in the interglacial (mis 7 or mis 5) lacustrine deposits exposed in the open-cast lignite mine of neumark nord (germany), represent one of the most outstanding samples of straight-tusked elephants in the pleistocene of europe. in 1994, a skeleton of an adult female (e8 hk 2007:55) was found in nearly anatomical connection. the postcranial bones were almost all preserved, the skull was partially destroyed, and the tusks and mandible were missing. wearing stage of molars and fusion of bones, as well as the pelvis morphology indicate a 39-40 years old female for which a height at the shoulders of about 2,9 m and a weight of about 5000 kg have been calculated. the most peculiar traits of this female are the serious scoliosis that affected its vertebral column and the invasive arthritis that deformed its femur and pelvis girdle on the right side. riassunto: marano f. & palombo m.r., una femmina di “elefante antico” con malformazioni ossee del giacimento di neumark nord (germania). i resti di palaeoloxodon raccolti per più di dieci anni (1985-1996) nei depositi lacustri (mis 7 o mis 5) nella miniera di lignite di neumark nord (germania), rappresentano una tra le più ricche popolazioni di “elefante antico” nel pleistocene europeo. nel 1994, fu rinvenuto uno scheletro pressoché completo e in parziale connessione anatomica di una femmina adulta (e8 hk 2007:55). il cranio è parzialmente danneggiato, mancano le difese e la mandibola, mentre le ossa dello scheletro postcraniale sono in discreto stato di conservazione. il grado di usura dei molari superiori, lo stato di ossificazione delle ossa degli arti e la morfologia del bacino indicano che lo scheletro appartiene ad una femmina di circa 39 40 anni di età, alta alla spalla circa 2,9 m con una massa corporea di circa 5000 kg. questo esemplare presenta interessanti patologie ossee, in particolare l’intera colonna vertebrale è stata affetta da scoliosi, mentre il femore destro e il bacino sono stati interessati da iperossificazione. entrambe le patologie furono probabilmente conseguenti ad un trauma giovanile. key words: palaeoloxodon, age, sex, body mass, pathology, pleistocene, germany. parole-chiave: palaeoloxodon, età, sesso, massa corporea, patologie, pleistocene, germania. 1. introduction the site of neumark nord is one of the richest in remains of palaeoloxodont elephants and undoubtedly the richest in central europe. since the early 80’s, an extraordinary rich sample of fossil remains was retrieved from the lacustrine deposits exposed in the open-cast lignite mine of neumark nord 1 (sachsen-anhalt, middle east germany) (mania, 2010) (fig. 1). at neumark-nord 1, a long stratigraphical succession documents the environmental evolution of an endorheic basin during a complete interglacial climatic cycle. the lacustrine deposits have been supposed to be late middle pleistocene in age (mis 7) on the basis of vegetational data, indicating subcontinental, mild climatic conditions (grübe, 2003; seifert-eulen, 2010), as well as of the presence of apodemus maastrichtiensis, a species present at weimar-ehringsdorf but not recorded from the eemian deposits of the area (heirich, 2001, 2010). this chronology has been questioned by some authors, who considered the interglacial to be the eemian (mis 5e) (kolfschoten, 2000; koenigswald, 2007, boettger et al., 2009 and references in those papers). recently esr dating of few samples might support an eemian age (schüler, 2010), whilst data obtained by amino-acid racemisation of the “intra-crystalline” fraction of bithynia tentaculata opercula are consistent with a late middle pleistocene age (penkman, 2010). the lacustrine sediments lie with no hiatus over a ground moraine ascribed to the “drenthe-glaciation” by mania (1999), and are overlaid by thick loess layers, then the succession is closed by muddy interglacial sediments and glacial deposits, respectively, thought to be eemian and weichselian in age (mania, 1999, 2004) (fig. 2). the rich palaeontological record comes from the first interglacial cycle, and counts about two hundreds of plant species, invertebrates, insects, and a diversified vertebrate fauna, including several, more or less complete, skeletons of large mammals (elephants, rhinoceroses, fallow deer, red deer, aurochs as well as some carnivores such as wolf, lion and spotted hyaena). elephant remains were retrieved from 6 fossil-bearing layers within the lower, middle and upper »gyttja«, which represent successive episodes within the small lake fillf. marano & m.r. palombo 94 ing (mania 1999, 2004) (fig. 2). taking into account the place the remains were collected from, their dimensions as well as the progression in tooth eruption and epiphysis fusion, the minimum number of elephant individuals found at neumark nord could be nearly 70, though the calculated number would be overestimated, because of the difficulty to assessing the skull fragments, and largely incomplete bones from “bone beds”, which were seriously damaged by excavators (palombo et al., 2010). according to the research performed to date, the morphology and biometry of skulls, tusks, molars and postcranial bones indicate that the specimens fall within the variability of european straight-tusked elephants (see e.g. osborn, 1942; trevisan, 1949; maccagno, 1962; aguirre, 1968-1969; beden, 1969; kroll, 1991; tsoukala & lister, 1998; davies, 2002; palombo et al., 2010). this paper is aimed at assessing the ontogenetical age, sex and body size as well as to briefly describe the pathological bones of an almost complete skeleton found in the october 1994 in the fossiliferous level 6.1, at a distance of about 150 m from the coastline of the lake basin (fig. 2, 3). at the time of discovery, the skull was still in articulation with the vertebrae, the pelvis was in anatomical position, while the long bones were disarticulated and partially dislocated. the exceptionally well preserved stomach contents, with the remains of its last meal, were found under the chest (grübe et al., 2010). the skull is partially destroyed, the maxilla is well preserved and the molariform teeth are located in the alveoli, while tusks and jaw are missing. the postcranial bones are almost all preserved except for carpal and metacarpal bones, while the tarsals are represented by calcaneus, astragalus, navicular, cuboid, right mesocuneiform and ectocuneiform bones, some sesamoids are also present (fig.4). this specimen (e8: hk 2007: 55) is stored in the landesmuseum für vorgeschichte in halle saale (germany). 2. methods the completeness of the remains has made it possible to determine both age and gender, as well as body mass and shoulder height of the studied e8 individual. the age was inferred according to the progression in tooth eruption and wear of plates of the upper molars, adapting to these teeth the method tested by laws (1966) on the lower molars of extant african elephants (loxodonta africana) and also applied to fossil species (roth, 1984; haynes, 1991). the status of the epiphyseal-diaphyseal junction of long bones has also been taken into account (roth, 1984; haynes, 1991). about the gender determination, several features have been regarded as of potential information about the sex of a proboscidean, e. g. body size, length and stoutness of long bones, morphology and size of skull and teeth (molars and tusks), atlas and epistropheum, pelvis and carpal bones (see palombo & villa 2003, and references therein). the gender of e8 elephant was inferred based on the morphology and dimensions of the pelvis girdle, which have been demonstrated to be particularly appropriate and have been largely applied to determine the gender in fossil proboscideans (kroll 1991, lister 1996; göhlich, 2000; palombo & villa, 2003). body mass was considered as the best proxy of body size, according to gingerich et al. (1982). body mass of proboscideans has been estimated using different allometric equations (e.g. roth 1990, palombo & giovinazzo, 2005; christiansen, 2004). here, we calculated the body mass of e8 by means of the regression equations proposed by christiansen (2004), regarded as the most appropriate when either the actual shoulder height or the inferred circumference of manus are not available. measurements were taken only on the left long bones because of the pathology affecting the right hind leg of e8 elephant. the stature was inferred combining the results of direct measurements of the forelimb (but acropodial bones) and the equation proposed by osborn (1942), this because of the poor preservation of the humerus, for which only the functional medial length is available. 3. description and results 3.1 main morphological features skull according to the preserved fragments of skull, the nuchal fossa was deep and showed rough surface (fig. 5b), the frontal bones flat and rather developed antero-posteriorly. the fan, is moderately expanded; the tusk-sockets are rather small and gently bent towards the lateral side (fig. 5e), the premaxillary fossa becomes rapidly shallow, broad and somewhat convex towards the distal end of the fan (fig.5c). maxillary bones have a thin and short pyramidal process, the last molariform teeth (see below) were not completely a pathologic straight-tusked elephant female … 95 erupted, and residual, small alveoli are present on both sides. teeth the not completely erupted molariform teeth have 8 plates in use, while a not evaluable number of plates, all fused together, occupy the entire free portion of alveoli, whose posterior portion is well ossified. the lateral side of the alveoli is locally broken, enabling us to see how the roots of molars are completely formed and fused to the plates (fig. 5d). accordingly, the teeth have been regarded as last molars (m3) (marano, 2009), consistently with the degree of epyphysealdyaphyseal fusion of long bones (see below). the morphology and dimension of the molars fall in the range of south european straight-tusked elephant populations. the molars are narrow and high crowned, the occlusal surface is ovate and slightly convex, plates are slightly bowed out on the lateral side, in the less worn plate, the enamel occlusal figures are formed by a large oval central loop and two small lateral loops. at an intermediate wear stage, the enamel figures show a moderate medial expansion. the enamel is thin, crinkled, densely and regularly folded, and the folds extend on the entire length of the enamel figure. stylohyoideum in both right and left stylohyoideum the posterior ramus is broken, the superior ramus, the less developed, is moderately elongated, and the inferior ramus is slender, gently curved upwards and backwards, without any evident lateral deflection; in anterior view it shows a gently concave lateral outline. postcranial skeleton the vertebral column possesses 7 cervical, 19 thoracic (including ribs as well), 4 lumbar, 5 sacral vertebrae, while the maximum number of caudal vertebrae is unknown. the morphology of the limb bones and pelvis girdle is consistent with those known for the european straight-tusked elephants (e.g. maccagno 1962, trevisan 1949, kroll 1991, tsoukala e lister 1998): the humerus is characterized by a large and angled deltoid tuberosity and a more or less deep deltoid fossa; the ulna is massive with a robust olecranus and wide distal articular surface; the left femur has a relatively short neck, angled on the diaphysis of about 40°, the diaphysis is moderately twisted as is commonly found in femora of adult individuals; the tibia possesses a weak cnemial crest, the distal epiphysis is smaller than, but nearly as massive as the proximal epiphysis. the general shape of the tarsal bones does not substantially differ from that of the actually quite variable european straight tusked elephants (trevisan, 1949; kroll, 1991; ferretti, 2008). the pelvis shows a gently curved lateral profile of the ileum wing, less rounded than in elephas maximus, but more rounded than in loxodonta africana africana and mammuthus primigenius (see palombo & villa 2003 for a discussion). with the latter two species, the pelvis of e8, as well as that of straight tusked elephants, shares a ileum with a more transversally elongated wing. 3.2 age, sex, body size age the peculiar progression in displacement of the molariform teeth, characterizing elephants, provides a particularly useful means for determining their age. accordingly, the first step in determining the age of e8 elephant was assessing the age on the basis of the eruption progress and the degree of wear of its upper fig. 2 neumark-nord 1 basin, stratigraphical section. on the left the lake at the time of the deposition of lower (a), middle (b) and upper (c) »gyttja« (mania, 2004); dots indicate the main findings of elephant remains, the star indicates the place where the skeleton of e8 was found (modified from palombo et al., 2010). sezione stratigrafica del bacino di neumark-nord. sulla sinistra il lago al momento della deposizione del »gyttja« inferiore (a), medio (b) e superiore (c (mania, 2004); i punti indicano i principali ritrovamenti dei resti di elefanti; la stella indica il punto del ritrovamento di e8 (modificato da palombo et al., 2010). molars. in e8 both molariform teeth (m3) are not completely erupted, furthermore, the m2 were already expelled, but residual, small alveoli of m2 are still pre s s 96 fig. 3 skeleton o lo scheletro dell’e fig. 4 skeletal served and studie schema dello sch scheletrici trovati of elephant e 8: s esemplare e8: in plan of e8: in re ed. heletro dell’esemp e studiati. stomach content in nero il contenuto ed the skeletal el plare e8: in rosso n black (modified dello stomaco (m ements pregli elementi after mania, 2010 modificato da mani served. the vanced: the 8 plates, sho first five plat proposed by ing into acco and upper tusked elep neumark no e8 specime corresponds the ag and wear o fusion of th vertebral bo indeed, are traces of on gende consistent w wide and ro ameter of 5 and flattene of the pelvic is 3.1, while aperture ver values fall w ter, 1996; values of th males. 0). ia, 2010). e stage of wear occlusal surfac owing a comple tes (fig. 5a). ac y laws (1966) f ount the similar molariform tee phants, and in ord rich sample en falls in the la s to an age rang ge inferred on of molars is co e axial and lim order of the sca almost complet going ossificatio er the morph with that of a fe ounded pelvic a 540 mm, reduc ed ilium. the ra c aperture versu e that of the d rsus the minimu with in the varia palombo & vil he same ratios f. maran r of m3 is not p ce (120 mm of ete fused enam ccording to the for the lowers m progression in eth often show particular obs e (palombo et aws’s xxii age ging from 37 to 4 the basis of th onsistent with th mb bones (rot apula and the c tely fused, show on (fig. 6). hology of the p male: it is chara aperture with a ced thickness o tio of the maxim us the minimum diagonal height um width of iliu ability range of lla, 2003; kro s being signific no & m.r. palombo particularly adlength) counts el loops in the pattern of age molars, but takthe both lower n by straigthserved in the al., 2010), the e group, which 40 years. he progression he epiphyseal h, 1984). the caput femuris, wing no or faint pelvis girdle is acterized by a transverse diof the ischium mum diameter m width of ilium t of the pelvic m is 3.4. both f females (lisoll, 1991), the antly lower in a t f m d s a pathologic straight fig. 5 the skull the penultimate h fused together an il cranio di e8 in v molari sono già st altre lamine in for fig. 6 scapula s distal cartilage. scapola con ossif simale. t-tusked elephant fe of e8 elephant in have already bee nd occupies the en vista ventrale (a), tati espulsi dagli a rmazione. showing the still im ficazione quasi co male … ventral (a) poster en expelled from ntire portion of the posteriore (b) e la alveoli. il particola mperfect ossificati ompleta dell’estrem rior (b), lateral (c) the alveoli. the p e alveoli. aterale (c). sono v are degli alveoli, vi on of the mità prosand frontal (e) vie postero-lateral vie visibili gli ultimi mo isti in norma poste body s 8511,38 kg on the basis physis of th maximum le mass of abo using the m gives the be coefficient a falling close can and asi the sh the forelimb possible hei it is about 2 osborn (19 10% higher about the sa 3.3 patholo some nord show a frequent am such as the some cauda top, while in brae, arthrit ew showing the p ew of the alveoli olari non del tutto ero-laterale (d) mo size the estim to 3162,27 kg. t s of the minimu e humerus, the ength of the tib out 5900 kg. t minimum circum est prediction th and low error ra e to the maximu an females (ha houlder height, i b long bones a ight of the miss 290 cm by usin 942). accordin r than a fema ame age (laws ogy of the elephan anomalous ossi mong vertebrae a e atlas, the oss al vertebrae the n others, such is or arthrosis h artially erupted la (d) shows the pl fuoriusciti, mentr ostra come non si mated body mas the first value w um circumferen e second on th bia, yielding an the body mass mference of the hanks to the hi ate, is approxim um body mass aynes, 1991). inferred by direc and tacking into sing more than ng the equation gly, e8 should le of loxodont , 1996; haynes nt bones found fication/growth, and teeth. in so ification is inco neural channel as the lumbar had caused hy 97 ast molars, whilst lates completely re i penultimi iano presenti ss ranges from was calculated nce of the diae basis of the average body calculated by e ulna, which igh correlation ately 4900 kg, of extant africtly measuring o account the 250 cm, while n proposed by d be of about ta africana of , 1991). d at neumark which is most ome vertebrae, omplete and in is open at the r sacral verteperossification w t t g s w f d i v g 98 and anomalous the skele which certainly bits of the eleph cimen are the s column and the and pelvis on th umn, the last th the lumbar and the vertebral co girdle, the righ shows a consp while the ilium mur, 7% shor fig. 7 pelvic gir formation and hyp left: the correspo deformation. cinto pelvico dell iperossificazione destro con il capu fig. 8 detail of t dettaglio dell’ace arthritis (fig. 9) normally bent, versely, no evid epiphysis or th arthritis and art er, domesticate elephants, mos goad injuries c s fusion of verteb eton of e8 sho have affected hant. the most serious scoliosis e invasive arthrit he right side (f horacic vertebra sacral ones ar olumn is marke ht acetabulum picuous hyperos shaft is sclerou rter than the rdle of e8 elepha per-ossification of onding femur show ’esemplare e8 co dell’acetabolo des ut marcatamente d he right acetabulu tabolo destro dell ): the caput fem the neck lengt dent anomalies he zeugopodium throsis are, actu d asian elephan st of pathologica caused by keep bral bodies. ows some mal the quality of li peculiar traits o s that affected it tis that deforme ig. 7). in the ve ae arch toward rch toward left. a edly twisted. in is anormously ssification along us (fig. 7, 8). th left, was def ant showing the e f the right acetabu wing the caput w on deformazione d stro. sulla sinistra deformato. um of e8. l’esemplare e8. moris is elongate th strongly redu s affected eithe m and achropod ually, common a nts. in domestic al ossifications pers. several c formations ife and haof this spets vertebral ed its femur ertebral colright, while as a result the pelvic large and g its edge, he right feformed by xtensive deulum. on the with a strong diffusa e a: il femore ed and abuced. conr the distal dium. both among oldcated asian are due to cases have also been re young anim difficulty but pear. thus fects becom 4. discuss morph obtained by understandi variability of althou laeoloxodon related to bu hasi, 2004; s 2010), in the the nomenc phants”. dis onomic statu loxodon”, as as present elephants h the asian sp fide species fig. 9 fem showing the caused by the time. femore dell’e marcata defo artrite l’esemp eported for zoo mals tolerate tra t, when they gro it would take a me clear. sion hological feature y biometrical an ng of the mor f european strai ugh several dat n as a bona fid ut separated fro shoshani et al. e literature, ther clature for eur sagreements e us (genus or su s well as on the in eurasia. th ave been cons pecies “elephas s, elephas antiq ur of e8 elephan extensive defo e severe arthritis esemplare e8 in n ormazione e ipero plare ha sofferto p f. maran o elephants too. umatic injuries ow older, the p a long time befo es shown by e nalysis, contribu rphological and ight-tusked elep a concur, to de de elephantine g om elephas (inu ., 2007; palomb re are different o rasian “straigh ssentially cente ubgenus) ascrib e number of spe he european s idered as belon s namadicus” or quus/palaeoloxo nt in anterior and ormation and hy the female had s norma anteriore e ossificazione. a c per lungo tempo. no & m.r. palombo it seems that without much problems reapore arthritis efe8 and results ute to a better d dimensional phants. esignating pagenus, closely uzuka & takabo & ferretti, opinions about ht-tusked eleer on the taxed to “palaeoecies regarded traight-tusked nging either to r, as one bona odon antiquus. d posterior view, yper-ossification, suffered for long e posteriore con causa della forte a pathologic straight-tusked elephant female … 99 alternatively, both these species have been considered present in europe. two morphotypes have been recently described by saegusa & gilbert (2008): the italian “namadicus-like” morphotype (showing an extreme developed parieto-frontal crest, nearly reaching the external choanae), and the “german-stuttgart” morphotype (characterized by a weak development of the parietofrontal crest). although the parieto-frontal and nuchal crests of e8 skull were seriously damaged during the recovery, some preserved large fragments indicate that its forehead could have been wide and gently convex. accordingly, the morphology of the preserved parieto-frontal part of the skull of e8 seems to confirm the peculiar development of the parieto-frontal crest, shown by some adult males from neumark nord (palombo et al., 2010), which differentiates the skulls of central europe (especially from germany) from those of southern europe. although the development of the parieto-frontal crest of the skulls from neumark nord are variable, they are mainly characterized by a moderately extended forehead and by a dorsally positioned parieto-frontal crest, as observed in skulls ascribed by saegusa & gilbert (2008) to the “stuttgart” morphotype. accordingly, most of the german palaeoloxodon populations do not present the morphological “namadicus” traits shown by the italian continental adult elephants ascribed by saegusa & gilbert (2008) to this morphotype e.g. skulls from la polledrara cecanibbio, (palombo et al., 2003; palombo & ferretti 2005) as well as by the endemic sicilian species palaeloxodon mnaidriensis, showing a parieto-frontal crest strongly advanced and folded to cover the forehead (ferretti, 2008; palombo et al., 2010). whatever the significance of such a difference, the morphology inferred by the skull fragments of e8, seems to confirm that females possibly had a less developed crest than males. the age of about 40 years, inferred on the basis of the degree of wear and number of plates of upper molars, is also supported by the degree of ossification of skeletal elements. this age confirms a prevalence of adults older than 45 years, in the elephant population of neumark nord while only the 3% of the population is younger than 6 years. the body mass of e8, 34% lower than average body mass estimated for neumark nord elephants, is consitent with the small size of this individual, confirming the great morphological and dimensional variability of this species and the significant dimensional gap between male and female in fossil and extant elephant populations (palombo et al., 2010). moreover the concordance among dimensional data, pelvis morphology confirms the usefullness of some pelvis features (particularly shape of pelvic aperture and proportion of the ilium shaft) as support to infer gender in proboscideans. 5. conclusion the specimen e8, as are all the elephants of the population of neumark nord, is assigned to the species palaeoloxodon “antiquus”, pending a systematic revision on the european straigt-tusked elephants (palombo & ferretti, 2010). the analysis on the nearly complete skeleton, indicates that e8 was a small female of about 40 years, weighting about 5000 kg, with a height at the shoulder about 290 cm. accordingly, e8 has almost the same size of females, but is significantly smaller than males of the same age from the same population. moreover, the presence of extensive bone abnormalities, indicats that the female was lame in its right leg and perhaps suffered a lot of pain during its life. the extensive sclerosis suggests that the arthritis developed over a quite long time, and probably was caused by a traumatic injury when the female was young, albeit it is difficult to ascertain what event actually caused these injuries. acknowledgements we are indebt to prof. h. meller for inviting one of us (maria rita palombo) to study the elephants from neumark nord. we thank everyone at the landesmuseum für vorgeschichte of halle for granting us access to the fossil material in their care and for their kindness and help. we are grateful to the anonymous reviewers for their comments on the manuscript. references aguirre, e., (1968/69). revisión sistemática de los ‘‘elephantidae’’ por su morfologıá y morfometrıá dentaria. estudios geológocos, (madrid), 24, 109-167; 25, 123-177, 317-367.beden, m., (1969) etude et réconstruction des restes de palaeoloxodon antiquus du chartelard (charente). bulletin sciences de la terre, université de poitier, 10, pp. 44-56. boettger t., novenkob e.y., velichko a.a., borisova o.k., kremenetski k.v., knetsch s., junge f.w. (2009) instability of climate and vegetation dynamics in central and eastern europe during the final stage of the last interglacial (eemian, mikulino) and early glaciation. quaternary international, 207 (1-2), pp. 137-144. christiansen p. (2004) body size in proboscideans, with notes on elephant metabolis. zoological journal of the linnean society, 140, pp. 523-549. davies, p., (2002) the straight-tusked eiephant (palaeoloxodon antiquus) in pleistocene europe. phd unpublished thesis, university of london. ferretti, m.p. (2008) the dwarf elephant palaeoloxodon mnaidriensis from puntali cave, carini (sicily; late middle pleistocene): anatomy, systematic and phylogenetic relationships. quaternary international, 182, pp. 90-108. gingerich, p.d., smith, b.h., rosenberg, k. (1982) allometric scaling in the dentition of primates and prediction of body weight from tooth size in fossils. american journal of physical anthropology 58, pp. 81-100. göhlich u.b. (2000) on a pelvis of straight-tusked elephant elephas antiquus (proboscidea, mammalia) from binsfeld near speyer (rhineland-palatine, germany). paläntologische zeitschrift, 74, pp. 205-214. grübe r. (2003) planzliche nahrungsreste der fossilen f. marano & m.r. palombo 100 elefanten und nashorner aus dem interglazial von neumark nord (geiseltal). veroffentlichungen des landesamtes für archäologie sachsen-anhalt, 57 (1) pp. 221-236. grübe r., palombo m.r., iacumin p. (2010) what did elephants from neumark nord eat? kataloge zur dauerausstellung im landesmuseum für vorgeschichte halle: elefantenreiche eine fossilwelt in europa. landesmuseum für vorgeschichte halle (saale), pp. 252-273. haynes g. (1991) mammoths, mastodonts, and elephants, cambridge university press, cambridge, 395 pp. heinrich w.d. (2001) kleinsäugerreste aus interglazialen ablagerungen von neumark nord, mitteldeutschland. praehistoria thuringica, 6/7 pp. 132138. heinrich w.d. (2010) klein aber oho: zwergwaldmaus apodemus maastrichtiensis. kataloge zur dauerausstellung im landesmuseum für vorgeschichte halle: elefantenreicheeine fossilwelt in europa. landesmuseum für vorgeschichte halle (saale), pp. 79-81. inuzuka n., takahashi, k. (2004) discrimination between the genera palaeoloxodon and elephas and the independent taxonomical position of palaeoloxodon (mammalia: proboscidea). in: baquedan, e., rubio, s. (eds), miscelanea en homenaje a emiliano aguirre. zona arqueologica 4 (2), pp. 234-244. museo arqueologico regional, madrid. koenigswald w. von (2007) mammalian faunas from the interglacial periods in central europe and their stratigraphie correlationthe climate of past interglacials. in sirocko f. (ed.) the climate of past interglacials, developments in quaternary sciences, 7, pp. 445-454 kolfschoten t. van (2000) the eemian mammal fauna of central europe. geologie en mijnbouw, 79 (2/3), pp. 269-281. kroll, w., (1991). der waldelefant von crumstadt. ein beitrag zur osteologie des waldelefanten elephas (palaeoloxodon) antiquus falc. and cautl. (1847). inaug. diss., tierärztl. kak., univ. münchen. laws r.m., (1966) age criteria for the african elephant, loxodonta a. africana. east african wildlife journal, 4, pp. 1-31. lister a.m. (1996) sexual dimorphism in the mammoth pelvis: an aid to gender determination. in: j. shoshani/p. tassy (eds.), the proboscidea (oxford), pp. 254-259. maccagno, a.m., (1962) gli elefanti fossili di riano (roma). geologica romana 1, pp. 33-132. mania d. (1999) 125 000 jahre klimaund umweltentwicklung im mittleren elbe-saale-gebiet. hercynia 32, pp. 1-97. mania d. (2004) neumark nord geologie eines interglazials. praehistoria thuringica, 10, pp. 26-42. mania d. (2010) neumark nord ein interglaziales ökosystem des mittelpaläolithischen menschen. veröffentlichungen des landesamtes für denkmalplege und elephas antiquus falconer & cautley, 1847 del pleistocene medio superiore di neumark nord: implicazioni sistematiche e paleoecologiche. archäologie, 6 (2), 527 pp. marano, f. (2009) elephas antiquus falconer & cautley, 1847 del pleistocene medio superiore di neuark nord: implicazioni sistematiche e paleoecologiche. università di roma, unpublished thesis. osborn h.f. (1942) proboscidea: a monograph of the discovery, evolution, migration and extinction of the mastodonts and elephants of the world. stegodontoidea, elephantoidea, 2. new york. palombo m.r., albayrak e., marano f. (2010) the straight-tusked elephants from neumark nord, a glance to a lost world. kataloge zur dauerausstellung im landesmuseum für vorgeschichte halle: elefantenreiche-eine fossilwelt in europa. landesmuseum für vorgeschichte halle (saale), pp. 218-247. palombo m.r., anzidei a.p., arnoldus-huyzendveld a. (2003) la polledrara di cecanibbio: one of the richest elephas (palaeoloxodon) antiquus sites of the late middle pleistocene in italy. deinsea 9, pp. 317-330. palombo m.r, ferretti m.p. (2005) elephant fossil record from italy: knowledge, problems, and perspectives. quaternary international, 126-128, pp. 107-136. palombo m.r., ferretti m.p. (2010) what about the taxonomical status of european straight-tusked elephants? quaternaire, ors serie, 3 pp. 27-28 palombo, m.r. & giovinazzo, c. (2005) elephas falconeri from spinagallo cave (south-eastern sicily, hyblean plateau, siracusa): brain to body weight comparison. monografies de la societat d’història natural de les balears, 12, pp. 255-264; palma de mallorca. palombo m.r., villa p. (2003) sexually dimorphic characters of elephas (palaeoloxodon) antiquus from grotte santo stefano (viterbo, central italy. deinsea, 9, pp. 293-315. penkman k. (2010) neumark nord 1: preliminary results of the amino acid analysis. kataloge zur dauerausstellung im landesmuseum für vorgeschichte halle: elefantenreiche-eine fossilwelt in europa. landesmuseum für vorgeschichte halle (saale), pp. 75-78. roth v.l. (1984) how elephants grow: heterochrony and the calibration of developmental stages in some living and fossil species. journal of vertebrate paleontology, 4, pp. 126-145. roth, l. (1990) island dwarf elephants: a case study in body mass estimation and ecological inference. in: damuth, j. & macfadden, b. j. (eds.): body size in mammalian paleobiology. estimation and biological implications. 151-179; cambridge (cambridge university press). saegusa h., gilbert w. h. (2008) elephantidae. in: w. h. gilbert, b. asfaw (eds.), homo erectus in africa, pleistocene evidence from the middle awash, ethiopia. the middle awash series 1, chapter 9 (berkeley and los angeles), pp. 195228. a pathologic straight-tusked elephant female … 101 schuler y. (2010) esr-datierung von zahnschmelzproben der archaologischen fundhorizonte von neumark-nord. kataloge zur dauerausstellung im landesmuseum für vorgeschichte halle: elefantenreiche-eine fossilwelt in europa. landesmuseum für vorgeschichte halle (saale), pp. 64-70. seifert-eulen m. (2010) die vegetation der warmzeit aus dem becken nn1 von neumark-nord aufgrund der pollenanalyse. kataloge zur dauerausstellung im landesmuseum für vorgeschichte halle: elefantenreiche-eine fossilwelt in europa. landesmuseum für vorgeschichte halle (saale), pp. 127-139. shoshani, j., ferretti, m.p., lister, a.m., saegusa, h., agenbroad, l.d., mol. d., takahashi, k. (2007) relationship within the elephantinae using hyoid characters. quaternary international 169-170, pp.174-185. trevisan, l., (1949) lo scheletro di elephas antiquus italiquus di fonte campanile (viterbo). paleontographia italica 44 (1948), pp. 2-78. tsoukala, e. lister, a. (1998) remains of straighttusked elephant, elephas (palaeoloxodon) antiquus falc. & caut., 1847 esr-dated to oxygen isotope stage 6 from grevena (w. macedonia, greece). bollettino della società paleontologica italiana 37 (1), pp. 117-139. ms. ricevuto il 25/05/2010 testo definitivo ricevuto il 8/10/2010 ms. received: may 25, 2010 final text received: october 8, 2010 available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 quaternary evolution of the fluviokarst rosandra valley (trieste, ne italy) stefano furlani1, furio finocchiaro1, giovanni boschian2, davide lenaz1, sara biolchi1, chiara boccali1, giovanni monegato3 1dipartimento di matematica e geoscienze, università di trieste, italy 2dipartimento di biologia università di pisa, italy 3cnr istituto di geoscienze e georisorse, torino, italy corresponding author: s. furlani <sfurlani@units.it > abstract: the stratigraphy of terraced sediments as well as morphological features of the middle reach of the rosandra valley (trieste, ne italy) were studied in order to reconstruct its quaternary evolution. this sector forms a fluviokarst valley, which is characterized by a deep incised gorge with abrasional features. downstream, the gradient is reduced, the valley widens and terraced deposits occur. alluvial/colluvial terraces crop out for about 1 to 1.5 km along the creek. they show the coalescence of the alluvial deposits with debrisfalls from the steep limestone slopes and colluvial fans related to some minor tributaries. the highest terrace is roughly 15 m high. 14c datings on a frustule plant collected in the lower part of the deposit (> 45.000 yrs. bp), together with geological and geomorphological considerations, suggested that the terrace scarp could be middle pleistocene in age. the geomorphic regime of the creek changed from aggradation to erosion, as recorded by fanhead trenching and incision of fluvial terrace scarps, and it still persists. the tectonic uplift, which is partly responsible for the downcutting of the terrace and is still active, could be related to the se-nw tilting of the karst plateau. keywords: alluvial terraces, fluviokarst valley, karst gorges, terra rossa, ne italy. 1. introduction the rosandra valley (glinščica), located at the northeastern side of the adriatic sea (fig. 1a), is a fluviokarst valley (cucchi et al., 2009). this kind of fluvial system responds to tectonics, climate and sea-level change (schumm, 1977; jones et al., 1999). fluviokarst forms develop mostly in the first stages of karstification in areas of intensive rainfall, when discharge into the karst system exceeds its conduit system capacity (dreybrodt & gabrovšek, 2002). carving processes are dominant in the upper part of the valley, while depositional processes prevail in the lower part; the profile is generally steeper near the watershed divide, while it is gentler at the mouth of the valley (leopold et al., 1964). the dinaric karst is dominated by fluviokarst valleys, with alternate intermountain basins, deep canyon and gorges (roglić, 1972), such as the valleys of the krka river in dalmatia or the vela draga in istria (miracle & forenbaher, 2005). lepirica (2015) suggested the influence of the structural setting in the development of many gorges in the central dinarides. on the contrary, floodplains are absent or confined in poljes (žebre et al., 2016) and terraces are usually fragmentary (bognar et al., 2012). many studies (e.g. aley, 1965; sanders, 1981; palmer, 1991; bognar et al., 2012; woodside et al., 2015) have shown that physical erosional processes may also play an important role in the formation of these systems. the quaternary deposits and the reconstruction of the evolution of fluviokarst valleys in the eastern adriatic were almost neglected. the study of such valleys can provide an important contribution regarding the evolution of fluviokarst valleys in the dinaric area. in the study area, frisia et al. (2005) studied a speleothem in the gualtiero savi cave in order to reconstruct the holocene climate change, while finocchiaro et al. (2015) described the sedimentological features of the stratigraphic sequence of the terrace here reported and they tentatively dated it from the eemian (mis5e) to mis2. it represents the only exposed quaternary sequence in the italian sector of the classical karst region. quaternary deposits inside the nearby the grotta degli orsi cave were studied by berto & rubinato (2013), who reported the presence of ursus spelaeus on the floor surface and the walls. carulli et al. (1980) highlighted the occurrence of a plioquaternary se-nw tilting of the karst plateau, from trieste to the northern sector of the gulf of trieste (fig. 1). the tilting was studied in detail along the coast using geomorphological, sedimentological, archaeological sea level markers and geophysical data (e.g. antonioli et al., 2004, 2007; furlani et al., 2011; carulli, 2011; biolchi et al., 2016). these studies suggested that the city of trieste is tectonically stable (melis et al., 2012), while the coast subsided moving toward nw. according to braitenberg et al. (2005) the tilting is still active. topographical and geomorphological indicators also underline a decrease in the elevation of the structural scarp in correspondence to the limestone-flysch contact toward nw (furlani et al., 2011). in this paper, we aim at discussing the quaternary paleogeographic evolution of the middle sector of the rosandra valley (fig. 1) using remote, field and laboratory data in the context of the gulf of trieste. work presented during the aiqua scientific conferences "waiting for the nagoya inqua xix congress", held in florence, june 18 19, 2015 170 s. furlani et al. 2. study area the study area belongs to the external dinarides and is located in the southwestern side of the classical karst region. this sector is characterized by nw-se oriented thrust and fault systems and is defined as trieste-komen anticlinorium (placer et al., 2010; fig. 1b). the western border of the classical karst region facing the gulf of trieste is characterized by the occurrence of the dinaric frontal ramp system (busetti et al., 2010). the latter is constituted by the nw-se segments of the palmanova line (carulli, 2011) and by the karst thrust (bensi et al., 2009). the main effect of this thrusts system is the overlaying of the thick cretaceouspaleogene carbonate succession over the eocene turbiditic one. the palmanova line connects the dinaric thrust system of the eastern friuli plain to the crni kal thrust in slovenia and separates the external dinarides from the istria-friuli underthrust zone, a separated deformed area being the boundary of the africa-apulia foreland (placer et al., 2010). in the rosandra valley, both the dinaric structures and ne-sw or ene-wsw oriented faults occur. they have played a crucial role in its geomorphological evolution. in particular, three main structures deeply conditioned its landscape: the fig. 1 a) geographical setting of the study area.; b) geodynamical framework of the classical karst region; c) se-nw profile, that highlights the topographic trend of the karst plateau related to the tilting, which develops in the same direction (the profile was produced using srtm data shuttle radar topography mission, http://www2.jpl.nasa.gov/srtm/). 171 quaternary evolution of the fluviokarst rosandra valley ............ composed by grey fossiliferous limestones; the transitional beds (early eocene, burelli et al., 2008), constituted by an alternation of limestones and marls with a thickness of about 50 m; the flysch, composed of alternated silty marlstones fig. 2 hillshade of the study area realized through the processing of lidar data from friuli venezia giulia region. the profiles across the rosandra valley are numbered from 0 to 11. fig. 3 the profiles along the rosandra creek: a) the overlapping of the profiles shows the uppermost one (green), near bottazzo, 4 profiles in the gorge (yellow to red), and 6 profiles in the lower part of the creek (grey shades). the profile 0 is out of the study area (magenta); b) longitudinal profile of the rosandra creek. thrust set located on the mount stena (petrinje thrust), the crinale thrust and the socerb thrust (fig. 1b). in the study area, three geological units, eocene in age, occur: the alveolinid-nummulitid limestone (early eocene), and sandstones (middle eocene, bensi et al., 2007). the rosandra creek, 15 km long, is the only surface stream in the trieste karst area (cucchi & zini, 2008). the creek originates from the confluence of two small streams, glinščica and grisa. the springs are located in the eocene flysch area (slovenia), then the creek crosses the cenozoic limestones, within a 1 km-long narrow gorge and a subsequent wide sector with small terraces. at the valley outlet, the rosandra creek forms a small floodplain up to the gulf of trieste (fig. 1b). d’amelio et al. (1997) measured a qmin of 0.18 m3/s and qmax of 3.0 m3/s, qmean ranging from 0.5-1 m3/ s. discharge leaks occur along the stream, in particular along the carbonate sector, due to water sinking. major increases after heavy rainfalls and minimum values during summer and winter droughts were measured (d’amelio et al., 1997). the annual average rainfall is 976 mm, while the average temperature is 15.0 °c and the relative humidity is 64%. dominant winds come from the first quadrant (80 days/year), in particular bora (ene), which is more common during the cold season and can reach a maximum speed of 181 km/h, as measured in 1996 (stravisi, 2008). in the valley the human frequentation is documented since the prehistory, with particular traces related to bronze age and historic periods. the remains of the roman aqueduct are still partly preserved along the left side of the valley (kocjančič, 2008). 3. methods geomorphological surveys were carried out in order to accurately map the extent of stream terraces. field surveys were carried out during winters 2012 and 2015 in order to characterize the quaternary outcrops. the study area was surveyed by airborne laser scanning fig. 4 geological map with geomorphological elements of the rosandra creek and surroundings. the geological map is redrawn from cucchi et al. (2013) and jurkovšek et al. (2016). 172 s. furlani et al. during march and april 2009 by the protezione civile of friuli venezia giulia region with a lidar system optech altm 3033 (minimum point density of 4 points x m2, relative horizontal and vertical accuracies are better than 1 and 0.3 m, respectively). lidar data, which are available in xyz format, were processed using arcgis 10.2 with 3d analyst tools. digital terrain models (dtms), with posting of 1m x px, were produced starting from the creation of tin (triangular irregular network) (li & heap, 2008). the 3d analyst tools allowed to transform tin into dtm, to sketch the longitudinal profile of the rosandra creek and obtain the cross profiles of rosandra valley (fig. 2, 3). the so-obtained 3d sections were converted in 2d through of an electronic sheet and autocad map 3d. the sedimentological features of an unconsolidated quaternary outcrop were described and sampled. grain size gravel at 1 phi were measured using sieves, meanwhile frequency curves lower than 2 mm were determined using malvern mastersize laser diffraction at ½ phi. mineralogical analyses have been carried out by using a siemens stoe d500 diffractometer, cuka radiation, monochromatized through a flat graphite crystal, in the range 2° 50° 2 ɵ with a 0.01° step. clay minerals have been separated through centrifugation and successively analyzed by xrd on oriented, glycholated and heated on glass slides in the range 2° 50° 2 ɵ. heavy minerals have been separated by means of tetrabromohetane (ρ = 2.96 g/cm3) and successively identified at microscope and sem. sem images and qualitative chemical analyses have been obtained by using a leica stereoscan 430i eds. 4. results dtm analysis, field survey data and laboratory analysis are reported in the following paragraphs. fieldwork was mainly devoted on the study of the outcrop near the premuda hut and the survey of the fluvial terrace which develops at the end of the gorge. the analysis of the relief and the stream profile have been developed. moreover, the stratigraphic section of the outcrop was described and analyzed in detail. 4.1. geomorphological analysis the upper reach of the valley, where the creek flows on flysch deposits, is characterized by low gradient (3.2%), up to the knickpoint, which corresponds to the rosandra waterfall (28 m hight). the top of the waterfall is at an elevation of 166 m a.s.l., while its foot is at 138 m a.s.l. downstream, the rosandra creek enters in a gorge with an average gradient of 4.8% (fig. 2, 3). the range in height of the gorge is from 138 m m.s.l. to 91 m m.s.l. this reach is characterized by incised meanders, from 1 m to 10 m large, potholes and other abrasion features, such as smooth surfaces, scallops, rapids, enclosed meanders and basins. after passing the gorge, the gradient is further reduced to about 2.6% (fig. 3). in correspondence of the crinale thrust, about hundred meters after the end of the gorge (fig. 2, 4), the creek gets the contribution of two small temporary tributaries, the south and north crinale creeks (fig. 5a). the first one forms a small alluvial fan with rounded sandstone blocks and cobbles in correspondence of the junction with the rosandra. the surface of this fan is highly anthropic because it was interested by intensive farming up to the first years of the last century. the north fig. 5 collage of images of the middle sector of the rosandra valley: a) alluvial/colluvial terrace at the confluence of the rosandra with the south crinale creek; b) the 28 m-high rosandra waterfall near bottazzo. it develops at the contact between eocene flysch and tertiary limetones. 173 quaternary evolution of the fluviokarst rosandra valley ............ crinale creek erodes limestone debris up to the rosandra, carrying limestone and sandstone blocks. downstream of the crinale thrust, a poorly preserved stream terrace occurs along both the sides of the rosandra creek roughly up to the premuda hut, where the valley becomes wider, up to about max 100 m. the terrace is composed by coalescing alluvial, colluvial with rockfalls and debrisfalls deposits. sometimes it is incised by small gully-type channels. toward the village of bagnoli della rosandra/boljunec, several check dams were built across the stream in order to counteract erosion by further reducing the flow velocity. the overlapping of the profiles shows that there is a significant difference in elevation a.s.l. from profile 11 (fig. 3, green) to profile 10 (fig. 3, yellow) and this is mainly related to the occurrence of the rosandra waterfall (fig. 5b). in correspondence of the profile 11, the valley is very large. from profile 10 to profile 7, the valley is v-shaped in the upper part, while the lower part is dominated by a gorge, which deepens the valley at its bottom. in this sector, the valley slopes are interested by steep limestone cliffs alternating flat banks (northern slope of the creek, profiles 9 to 10, southern slope of the creek, profile 7 to 9). from profile 6, the rosandra valley widens and alluvial terraces occur on the left side of the stream (profile 6 to profile 1), but also on the right side (profile 5 to profile 2). two orders of terraces are recogniza ble on the left side of the rosandra creek in this sector, while on the right side limestone beds occur. the upper terrace is well-defined in the profiles 6 to 2. two orders of terraces are recognizable in correspondence of profile 1, while in profile 0 it is in the opposite side of the stream (fig. 3). 4.2. sedimentology the sedimentological analysis was carried out in correspondence of the highest and better preserved sector of the terrace. the most complete unconsolidated sediment outcrop occurs along the right bank of rosandra creek, just in front of the premuda hut (fig. 4, 6). it extends in length for about 100 m and has a maximum height of more than 12.8 m (fig. 6). the studied section is composed by a number of alternating gravelly and fine-grained levels. nine samples (a to h3, fig. 7) were collected to determine the sedimentological and mineralogical characteristics of the sequence and to define the related sedimentary processes and the paleoenvironmental setting. the graphic results of sedimentological and mineralogical analysis are reported in fig. 7 and fig. 8. most of the sequence is characterized by alluvial levels, which reflect different energy environments. alluvial levels, decimetric to metric in thickness, are characterized by high fig. 6 the stratigraphic sequence cropping out along the scarp of the terrace in front of the premuda hut (bagnoli, trieste). 174 s. furlani et al. percentage of gravel (80-40 %) together with rounded and sub-rounded sandstone clasts (fig. 6). the fraction finer than 2 mm is poorly classed or sometimes bimodal in size. the level 3.1 (sample f) is composed mainly by muddy gravels with sub-angular limestone clasts with modal size of 8-16 mm. gravelly levels are interbedded with thin (up to 0.6 m) fine-grained beds, which are more frequent in the lower part of the sequence. one of these layers (level 6, sample d, fig. 7) is made of coarse silt with very fine sand, well-sorted with very high percentage of quartz (93%). some blocks, up to 1 meter in size, are included in level 7 and are related to gravitational processes and landslides. the sedimentary succession can be interpreted as the interfingering of alluvial, colluvial or rockfalls and debrisfalls deposits (sensu blikra & nemec, 1998). radiocarbon datings from the level 2 indicates that the deposit is older than 45.000 years bp (sample: ltl12727a, radiocarbon age bp: >45.000 years, δ13 c (‰): -21.3±0.7). the succession can be roughly divided in three units (fig. 8): i) the basal unit, at the cliff toe (levels 1 and 2), which is made of medium and high-energy alluvial levels; ii) the middle unit (level 3 to 7), which is characterized by fine-grained sediments, talus deposits (originated by debris and rockfalls) and, to a lesser extent, alluvial deposits; iii) the upper unit of the sequence is again composed by coarse alluvial sediments of high-energy flow. 4.3. mineralogy the studied samples consist of calcite, quartz and feldspars. according to the percentages calculated using the intensities of the highest peak of each phases, layers 3, 11 and 12 (sample a, b, f) display a major amount of calcite (4060%), while layers 3.3, 6 and 8 (samples c, d, e) are characterized by the highest quartz content (>80%). in the layers 1.2 and 2 (sample g, h3 and h), the quartz content is between 70 and 80%. feldspars content is always below 5% (fig. 8). the analysis of clays shows that all the samples are very similar. among the clay minerals, montmorillonite and illitemontmorillonite mixed-layers suggest they are residual clays of neo-formation, as suggested also by lenaz et al. (2004). the heavy mineral assemblage was studied on selected layers, in particular levels 2, 3, 6 and 7 (samples c, d, e and g). the amount of heavy minerals is quite scarce and among the different minerals, garnet and zircon (sometimes euhedral, fig. 10) are the most abundant. chromite, magnetite, sulphides, tourmaline and rutile have been also found. in the layer 6 one single occurrence of a pale blue crystal have been found. according to the qualitative chemical analyses performed via sem it is an aluminum silicates (kyanite or sillimanite). 5. discussion and conclusions the new data collected along the rosandra creek show the complexity of the tectonic and geomorphic setting of the valley, but they yield also significant information to study its fig. 7 stratigraphic description of the premuda sequence. the circle diagrams show the percentage of gravel (red), sand (yellow) and mud (blue). fig. 8 percentages of calcite, quartz and feldspars in the studied layers by means of xrd. 175 quaternary evolution of the fluviokarst rosandra valley ............ quaternary evolution. the middle reach of the rosandra creek develops in correspondence to main tectonic structures. the crinale thrust is the most important and dissects the valley, producing a diversion in the flow direction from nw to sw (fig. 2, 4). lithology also plays an important role in its evolution. the upper part of the stream develops in eocene flysch, the middle part is cut in limestones while the lower part flows in the floodplain. the contact between the flysch formation and limestones is characterized by a knickpoint (28 m high), which develops along a fault plane (fig. 4). abrasional features on the top of the waterfall indicate that the knickpoint is currently eroding upstream (fig. 5b). downstream, rosandra creek flows into the limestone gorge. here, the hillsides become steeper, with structural terraces along the right slopes (fig. 3, profile 10) and the presence of landslides (paronuzzi et al., 2016). in this sector, a deep canyon-like depression dominated by abrasional landforms occurs. the gradient is the highest in the study area, about 4.8%. this sector is characterized by almost complete absence of deposits except for some limestone cobbles or small blocks fallen from the slopes. moreover, the waterfall acts as a selective dam, because only fine sediments flow downstream. at the end of the gorge, the gradient becomes considerably lower, 2.6%, and the waterflow speed is significantly reduced (profile 6). two ephemeral tributaries, the first from the south and the second from the north follow the crinale thrust and flow into the valley roughly at the end of the gorge. the southern one created an alluvial fan mostly made of rounded sandstone blocks and cobbles (fig. 5a). downstream, a partially eroded stream terrace occurs along both the sides of the rosandra creek roughly up to the premuda hut. the downstream continuity of the terrace is clear along both sides of the creek. colluvium is made of clastic slopewaste materials, coarse grained and angular, deposited at the foot of the hillslopes, mainly transported by sedimentgravity processes (holmes, 1965). the lower part of the terrace is mainly made by rounded or sub-rounded sandstone blocks and cobbles in a fine matrix. a survey along the rosandra stream highlighted the absence of sandstone clasts in the sector between the waterfall and the end of the gorge, suggesting the mixed contribution of the aforementioned tributaries and the rosandra to the sedimentation of the terraces. on the contrary, during modern floods, rosandra creek carries large amount of suspended fine sediments from the upper sector of the flysch basin. in correspondence of the premuda hut, the valley is larger than other reaches, so the preserved terrace is relatively wide. in front of the hut, the scarp of the terrace is about 12 m high and shows a stratigraphic succession. it represents the largest quaternary exposed deposit in the trieste area, except for cave deposits (andreolotti, 1965, 1966; belloni & orombelli, 1972; falguares et al., 2008; boschian, 1998; boschian & desantis, 2011). 14c age on a frustule plant collected in the lower part of the deposit indicates that the age of the sample is older than 45.000 yrs. bp. the plant remain can hardly be reworked because the upstream narrow and steep topography of the valley prevent sedimentation. hence, the age of the lower part of the succession could be also older than late pleistocene. the sedimentation of the sequence may have been also very fast, as testified by late holocene sequences in western istria (faivre et al., 2011; felja et al., 2015). the composition of sample c, d and e is similar to the composition of terra rossa soils in the trieste karst area (lenaz et al., 1996), which are mainly constituted by quartz (about 90%), feldspars and clay minerals, while calcite is absent. other layers of the studied sequence are enriched in calcite suggesting local provenance by gravity processes from hillslopes. fig. 9 xrd of clay fraction on oriented, glycholated and heated glass slides. fig. 10 a) aluminum silicate in layer e; b) zircon in layer c. 176 s. furlani et al. a b acknowledgements we are very grateful to dr. elia zordan for field surveys and to protezione civile of regione autonoma friuli venezia giulia for lidar data. moreover, we thank mr. mauro bussi, university of trieste, for sedimentological analysis. references andreolotti s. (1965) rinvenimento di un deposito alluvionale ciottoloso-argilloso in una cavità relitto del carso di basovizza (trieste). atti e memorie della commissione grotte e. boegan, 4, 101-106. andreolotti s. (1966) i depositi di riempimento nelle cavità del carso triestino. atti e memorie della commissione grotte e. boegan, 5, 49-71. aley t. (1965) corrasional cave passage enlargement. caves notes, 7 (1), 2-4. antonioli f., carulli g.b., furlani s., auriemma r., marocco r. (2004) the enigma of submerged marine notches in northern adriatic sea. quaternaria, 8, 27-36. antonioli f., anzidei m., lambeck k., auriemma r., gaddi d., furlani s., orrù p., solinas e., gaspari a., karinja s., kovacic´ v., surace l. (2007) sea level change during holocene from sardinia and northeastern adriatic (central mediterranean sea) from archaeological and geomorphological data. quaternary science reviews, 26, 2463-2486. belloni s., orombelli g. (1972) i depositi fluviali di riempimento di alcune cavità carsiche nei dintorni di trieste. rivista italiana di paleontologia, 78 (1), 163172. bensi s., fanucci f., pavšić j., tunis g., cucchi f. (2007) nuovi dati biostratigrafici, sedimentologici e tettonici sul flysch di trieste. rendiconti online società geologica italiana, 4, 1-145. bensi s., fanucci f., podda f. (2009) strutture a macro e mesoscala delle dinaridi triestine (carta geo-cgt del fvg). rendiconti online soc. geol. it., 5, 32-35. berto c., rubinato g. (2013) the upper pleistocene mammal record from caverna degli orsi (san dorligo della valle dolina, trieste, italy): a faunal complex between eastern and western europe. quaternary international, 284, 7-14. biolchi s., furlani s., covelli s., busetti m., cucchi f. (2016) morphoneotectonics and lithology of the eastern sector of the gulf of trieste (ne italy). journal of maps, 12 (5), 936-946. doi: 10.1080/17445647.2015.1099572 blikra l.h., nemec w. (1998) postglacial colluvium in western norway: depositional processes, facies and palaeoclimatic record. sedimentology, 45, 909-959. bognar a., faivre s., buzjak n., pahernik m., bocic n. (2012) recent landform evolution in the dinaric and pannonian regions of croatia. in: loczy d., stankoviansky m., kotarba a. (eds.), recent landform evolution. the carpatho-balkan-dinaric region. springer, 313-344. boschian g. (1998) middle pleistocene to early holocene infilling deposits in the trieste karst caves. proceedings xiii uispp congress, forlì, september 8-14, 1996, according to chiesa (1972), šinkovec (1974) and lenaz et al. (1996), accessory minerals in sandy fraction of karst soils are rutile, tourmaline, garnet, cr-spinel, corundum, hematite and limonite, zircon and phyllosilicates as biotite and muscovite. several authors (malaroda, 1947; wiesender, 1960; woletz, 1960; crnjakovic, 1994; lenaz et al., 1996; lenaz et al., 2000) suggested, by comparing the mineralogy of terra rossa and that of the surrounding silicoclastic formations, that terra rossa is the result of flysch weathering. the mineralogy of the here studied samples is very similar to that of the already studied karst soils and of the flysch so that an analogue source should be considered. the solely occurrence of one aluminium silicate could suggest that another supply, maybe reworked by aeolian processes, could be also present. regarding the evolution of the rosandra valley, the geomorphological and sedimentological reconstruction suggests the interaction between the floods, related to very rainy periods, and the constrain provided by the narrow riverbed affected by debrisfalls and rockfalls coming from the hillslopes. in correspondence of the premuda hut, the rosandra valley widens up to about 100 m allowing the preservation of ancient alluvial successions, as testified by alternations of fine and coarse units topped by the debris fan from moccò. also the tectonic setting of the area may have influenced the shaping of the valley. many authors highlighted the occurrence of a se-nw tilting of the karst plateau, from trieste to the northern sector of the gulf (antonioli et al., 2004, 2007; furlani et al., 2011; carulli, 2011; melis et al., 2012; biolchi et al., 2016), using geomorphological, sedimentological, archaeological and geophysical data. these studies indicated that the city of trieste is tectonically stable, while the coast subsided moving toward nw and, according to braitenberg et al. (2005) the tilting is still active. cox (1994) suggested that streams that flow in the direction of tilting produce steepened gradients, such as the aforementioned sector of rosandra interested by the gorge, which flows towards nw, following the direction of the tilting. comparing the topographical trend of the karst plateau (fig. 1c), we suggest that the rosandra valley could represent the southeastern prosecution of the tilting. the rejuvenation of the rosandra creek, together with the subsequent stream downcuts, could be related to the uplift of the rosandra valley, se limit of the tilted area. moreover, the contribution of late quaternary sea level changes could also have enhanced the incision of the valley. the geomorphic regime changed to erosion, as recorded by fanhead trenching and cutting of fluvial terraces, and it persists until present, as highlighted by small terraces incised in flysch along the north crinale creek. now, rosandra and tributaries do not provide coarse sediments like the ones found in the deposits. during present-day floodings, only fine material is carried out and the waterfall acts as a natural dam for sandstone blocks from flysch. therefore, the incision of the gorge may have been accelerated during rainy periods, as suggested by furlani et al. (2009) in high energy environments, when large amount of flysch materials provided abrasion tools that increased erosion rates, maybe of one or two orders of magnitude. 177 quaternary evolution of the fluviokarst rosandra valley ............ 1, 3, subsct. geoarchaeology, 383-386. boschian g., desantis a. (2011) bears and sediments at caverna degli orsi/medvedja jama (trieste, italy). in: toškan b. (ed.),fragments of ice age environments. proceedings in honour of ivan turk’s jubilee, opera instituti archaeologiae sloveniae, 21, zrc sazu, ljubljana, 181-201. braitenberg c., nagy i., romeo g., taccetti q. (2005) the very broad-band data acquisition of the long-base tiltmeters of grotta gigante (trieste, italy). journal of geodynamics, 41, 164-174. burelli g., masetti d., furlani s., biolchi s., bensi s., cucchi f., piano c. (2008) the drowning sequence of the paleogenic carbonate ramp outcropping in the trieste karst. egu general assembly, geophysical research abstract, 10, 2008-a-09713, wien. busetti m., volpi v., nicolich r., barison e., romeo r., baradello l., brancatelli g., giustiniani m., marchi m., zanolla c., wardell n., nieto d., ramella r. (2010) dinaric tectonic features in the gulf of trieste (northern adriatic). boll. geof. teor. appl., 51, 117128. carulli g.b., carobene l., cavallin a., martinis b., onofri r., cucchi f., vaia f. (1980) evoluzione strutturale plioquaternaria del friuli e della venezia giulia. in: contributi alla carta neotettonica d’italia. cnr progetto finalizzato geodinamica, 356, 488-545. carulli g.b. (2011) structural model of the trieste gulf: a proposal. journal of geodynamics, 51, 156-165. chiesa s. (1972) aspetti mineralogici di un riempimento di "terra rossa" in una dolina del carso i monfalcone (trieste). st. trent. sc. nat. sez. a, 49, 42-50. cox r.t. (1994) analysis of drainage-basin symmetry as a rapid technique to identify areas of possible quaternary tilt-block tectonics: an example from the mississippi embayment, geological society of america bulletin, 106, 571-581. crnjakovic m. (1994) the detrital versus authigenic origin and provenance of mineral particles in mesozoic carbonates of central croatian karst area. geologia croatica, 47/2, 167-179. cucchi f., zini l. (2008) cenni geomorfologici. in: gasparo d. (ed.), la val rosandra e l’ambiente circostante, comune di san dorligo della valle, lint editoriale srl, trieste, 19-22. cucchi f., finocchiaro f., muscio g. (a cura di) (2009) geositi del friuli venezia giulia. volume edito per conto del servizio geologico della regione autonoma friuli venezia giulia, udine, pp. 383. cucchi f., piano c., fanucci f., pugliese n., tunis g., zini l. (2013) carta geologica del carso classico. tratta dalla carta geologica di sintesi alla scala 1:10.000 progetto geo-cgt. regione autonoma friuli venezia giulia. d’amelio l., dini m., semeraro r. (1997) geochemicalisotopic study of the underground waters and scheme of the karst hydrostructure of mt. stena (karst of trieste). ipogea, 2, 15-38. dreybrodt w., gabrovsek f. (2002) basic processes and mechanics governing the evolution of karst. in: gabrovsek f. (ed.), evolution of karst: from prekarst to cessation. carsologica zalosba zrc ljubljana, 115-145. faivre s., fouache e., ghilardi m., antonioli f., furlani s., kovačić v. (2011) relative sea level change in istria (croatia) during the last 5 ka. quaternary international, 232, 132-143. falguères ch., bahain j.j., tozzi c., boschian g., dolo j.m., mercier n., valladas h., yokoyama y. (2008) esr/useries chronology of the lower palaeolithic palaeoanthropological site of visogliano, trieste, italy. quaternary geochronology, 3 (4), 390-398. felja i., fontana a., furlani s., bajraktarević z., paradžik a., topalović e., rossato s., ćosović v., juračić m. (2015) environmental changes in the lower mirna river valley (istria, croatia) during the middle and late holocene. geologia croatica, 68(3), 209-224. finocchiaro f., furlani s., lenaz d., boschian g., zordan e. (2015) sedimentological and mineralogical reconstruction of a quaternary sequence in val rosandra (trieste, ne italy). in: monegato g., gianotti f., forno m.g. (eds), the plio-pleistocene continental record in italy: highlights on stratigraphy and neotectonics, miscellanea ingv, 26, 16-17. frisia s., borsato a., spötl c., villa i.m., cucchi f. (2005) climate variability in the se alps of italy over the past 17000 years reconstructed from a stalagmite record. boreas, 34, 445-455. furlani s., cucchi f., forti f., rossi a. (2009) comparison between coastal and inland karst limestone lowering rates in the northeastern adriatic region (italy and croatia). geomorphology, 104, 73-81. furlani s., biolchi s., cucchi f., antonioli f., busetti m., melis r. (2011) tectonic effects on late-holocene sea level changes in the gulf of trieste (ne adriatic sea, italy). quaternary international, 232, 144-157. holmes a. (1965) principles of physical geology. london and edinburgh, thomas nelson and sons, pp. 1288. jones s., frostick l.e., astin t.h. (1999) climatic and tectonic controls on fluvial incision and aggradation in the spanish pyrenees. journal of the geological society of london, 156, 761-769. jurkovšek b., biolchi s., furlani s., kolar-jurkovšek t., zini l., jež j., tunis g., bavec m., cucchi f. (2016) geology of the classical karst region (sw slovenia-ne italy). journal of maps, 12(s1), 352-362. kocjančič v. (2008) l’uomo e le sue attività in val rosandra. in: gasparo d. (eds.), la val rosandra e l’ambiente circostante, comune di san dorligo della valle, lint editoriale srl, trieste,137-150. lenaz d., de min a., longo salvador g., princivalle f. (1996) caratterizzazione mineralogica della terra rossa di dolina del carso triestino. boll. soc. adr. di sc., 77, 5967. lenaz d., kamenetsky v.s., crawford a.j., princivalle f. (2000) melt inclusions in detrital spinels from se alps (italyslovenia): a new approach to provenance studies of sedimentary basins. contrib. mineral. petrol., 139, 748758. lenaz d., potleca m., zini l. (2004) caratterizzazione mineralogica delle frazioni argillose nei depositi di riempimento della grotta g. savi (carso triestino, 178 s. furlani et al. desanstalt, 172-174. woodside j., peterson e.w., dogwiler t. (2015) longitudinal profile and sediment mobility as geomorphic tools to interpret the history of a fluviokarst stream system. international journal of speleology, 44 (2), 197-206. žebre m., stepišnik u., colucci r.r., forte e., monegato g. (2016). evolution of a karst polje influenced by glaciation: the gomance piedmont polje (northern dinaric alps). geomorphology, 257, 143-154. italia). atti e mem. comm. grotte e. boegan, 39, 101106. lepirica a. (2015) genesis of inner gorges in the rakitnica canyon valley (central dinarides, bosnia and herzegovina). zeitschrift fur geomorphologie, 59(4), 515545. leopold l.b., wolman m.g., miller j.p. (1964) fluvial processes in geomorphology. w.h. freeman and company, san francisco, california, pp. 544. li j., heap a.d. (2008) a review of spatial interpolation methods for environmental scientists. geoscience australia record, 23, 137 pp. malaroda r. (1947) arenarie eoceniche della regione di trieste. boll. soc. adriat. sci. nat., 43, 90-112. melis r., furlani s., antonioli f., biolchi s., degrassi v., mezgez k. (2012) sea level palaeoenvironment during roman times inferred from coastal archaeological sites in trieste (northern italy). alpine and mediterranean quaternary, 25(1), 41-55. miracle p.t., forenbaher s. (2005) neolithic and bronze-age herders of pupicina cave, croatia. journal of field archaeology, 30 (3), 255-281. palmer a.n. (1991) origin and morphology of limestone caves. geological society of america bulletin, 103 (1), 1 -21. paronuzzi p., bolla a., rigo e. (2016) 3d stress-strain analysis of a failed limestone wedge influenced by an intact rock bridge. rock mechanics and rock engineering, 49 (8), 3223-3242. placer l. (2008) principles of the tectonic subdivision of slovenia. geologija, 51 (2), 205-217. placer l., vrabec m., celarc b. (2010) the base for understanding of the nw dinarides and istria peninsula tectonics. geologija, 53/1, 55-86. doi:10.5474/geologija.2010.005 roglić j. (1972) historical review of morphologic concepts. in: herek, m., stringfield, v.t. (eds.), karst: important karst regions of the northern hemisphere: amsterdam, elsevier, 1-18. sanders w. (1981) limestone denudation. in: sweeting m.m. (ed.), karst geomorphology: benchmark papers in geology. stroudsburg, pennsylvania: hutchinson ross publishing company, 320-343. schumm s.a. (1977) the fluvial systems. wiley, new york, pp. 338. šinkovec b. (1974) porijeklo terra rossa istre (the origin of terra rossa in istria). geol. vjesnik 27, 227-237. stravisi f. (2008) il clima. in: gasparo d. (ed.), la val rosandra e l’ambiente circostante. comune di san dorligo della valle-občina dolina, 51-57. vlahović i., tisljar j., velić i., matičec d. (2005) evolution of the adriatic carbonate platform: paleogeography, main events and depositional dynamics. palaeogeography, palaeoclimatology, palaeoecology, 220, 333-360. wiesender h. (1960) petrographie und petrologie der eozanen flyschsandsteine. verhandlungen der geologischen bundesanstalt, 166-171. woletz g. (1960) schwermineralanalysen der flyschsandsteine. verhandlungen der geologischen bunms. received: february 5, 2016 final text received: june 28, 2016 179 quaternary evolution of the fluviokarst rosandra valley ............ 180 microsoft word 05_rubinato_lm02.doc available online http:/amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 26 (1), 2013, 55-63 terrestrial vertebrates in mis 6 to mis 5 deposits of the zannona quarry (faenza, italy) giada rubinato1, marco sami2, federico fanti3, stefano marabini3, benedetto sala1, gian battista vai3 1 dipartimento di biologia ed evoluzione, università degli studi di ferrara, ferrara, italy 2 museo civico di scienze naturali, faenza, italy 3 museo geologico g. capellini, università degli studi di bologna, bologna, italy corresponding author : giada rubinato <giada.rubinato@student.unife.it> abstract: we report few vertebrate remains from the middle-upper pleistocene continental deposits of the zannona quarry (faenza, italy), including two incomplete upper dental series of stephanorhinus hemitoechus, a frontal with antlers of a cervid, and a fragmentary left scapula of an equid. this material provides additional information on the poorly known terrestrial faunal assemblages of the quaternary deposits in the romagna apennine foothills. data presented here are discussed within the framework of the well documented stratigraphic transition between the mis (marine isotope stage) 6 and 5 and support the role of vertebrate continental fauna in the correlation between marine and non-marine successions. keywords: middle to upper pleistocene, continental stratigraphy, mammals, biochronology. 1. introduction the zannona quarry site (cava zannona of local road signs) is located within the homonymous pit cave of pebbly and sandy material located a few kilometres south of the city of faenza (ravenna, italy) in the apennine foothills (fig. 1). the active quarry, located at about 60 meters above sea level on a wide terrace of the marzeno alluvial fan, is responsible for the exposure of deposits that are here referred to the palazzone morphostratigraphic unit (curzi et al., 1987) (fig. 2). exposed alluvial deposits reach a maximum thickness of 10-15 meters and rest unconformably on the uppermost deposits of the pliocene to pleistocene marine sequences of the romagna apennine (i.e. argille azzurre and sabbie gialle formations). such alluvial deposits have been recently included in the subsintema di bazzano (amorosi et al., 2009), which consist of coarse alluvial fan deposits interbedded with fine-grained alluvial plain beds. the bazzano subsynthem is dated to the uppermost middle pleistocene between 230 and 130 ka (amorosi et al., 2009). the zannona quarry deposits have been the subject of periodic investigation for a decade before the discovery in 2012 of nicely preserved vertebrate remains. specimens collected from the site allow to improve the chronostratigraphic and environmental resolution of the continental deposits of the area. data presented here support the role that vertebrate faunal turnover play in our palaeoecological understanding of cyclic warm and cool stages in the italian pleistocene continental successions. in particular, based on a more accurate chronostratigraphic and palaeoclimatic zonation of the middle to late pleistocene interval, this study attempts a correlation between terrestrial bioevents and the standard chronostratigraphical time scale and in particular with the marine isotope stages (mis) 6 and 5 (sanchez goñi, 1999; amorosi & colalongo, 2005; ferranti et al., 2006; antonioli et al., 2009; bertini et al., 2010). 2. synthetic stratigraphy of the continental deposits the continental deposits exposed at the zannona quarry rest unconformably on the sabbie gialle formation, and are divided into two unconformity-bounded units showing increasing trasgressive trend upwards (fig. 3). the lower ub unit is bounded at its bottom by a basal unconformity having regional extension and marking a major depositional hiatus, and by a prominent palaeosol at its top. the upper ub unit is bounded by the same palaeosol at the bottom and by a thick vetusol at the top. the basal deposits of the first interval are represented by a tabular and laterally continuous layer of coarse gravel (ø max ≈ 50 cm) with an average thickness of 5-6 meters (lower gravel layer in figs. 3 and 4). these braided-stream, channel deposits yielded an equine scapula as well as poorly preserved floated manufacts. basal deposits fine upward into clay-dominated, tabular beds with minor silt and fine-grained sandy deposits showing planar parallel stratification: overall, such alluvial and colluvial strata reach a thickness of 8-10 meters. this interval is also topped by a dark-grey to brown-colored, 40-60 cm thick, clay-silty buried soil which represents an important marker in the study area, cropping out over several square kilometers near the zannona quarry(fig. 5). this distinctive palaeosol has been originally reported from the spalancona locality by rubinato g. et al. 56 curzi et al. (1987), located a few hundred meters south of the zannona quarry: therefore, this marker bed is here referred to as spalancona palaeosol. it is moderately rich in organic matter, with well-developed pedostructures and minor carbonate concretions at its base. the palaeosol is traceable continuously within the palazzone morphostratigraphic unit over a distance of approximately 5 km from the quarry, lying sub-horizontally at an average depth of 4-5 meters from the unit top. the second sedimentary interval deposited above the spalancona palaeosol consists of silty, flood-plain beds up to 6 meter thick, punctuated by discontinuous erosive fine-gravely to sandy channelized bodies up to 1.5 m thick (ø max ≈ 10 cm), suggesting an incoming meandering stream deposits (upper gravel layer in figs. 3 and 4). pebbly and sandy deposits show significant pedogenetic alteration which is associated with the massive overlying vetusol that also bounds the upper surface of the ancient fluvial terrace. this distinctive represents a non-buried soil which underwent similar processes of soil formation over a period of time that include at least some part of the pleistocene (cremaschi, 1987), and therefore may provide important climatic and environmental information possibly related to the onset of the last interglacial transgression. relevant to this study, the latter coarse and lenticular deposits preserved the in situ deer frontal lobe with antlers and possibly the rhinoceros upper dental series. the continental succession exposed at the zannona quarry does not display major facies changes in the entire palazzone morphostratigraphic unit, with the exception of local differences in the thickness of the dis fig. 1 reference map the studied middle to late pleistocene succession at the cava zannona quarry near faenza, italy (modified from ©google earth; coordinates 44°15’05.98’’ n, 11°53’15.11’’ e). fig. 2 geological map of the area surrounding the cava zannona quarry. the construction of a gas pipeline (dotted line) provided additional insights on stratigraphy of the romagna plain deposits (modified after curzi et al., 1987). continental vertebrates from zannona quarry (faenza, italy) 57 cussed lithofacies. a stratigraphic analogy is represented by the succession exposed at the ex cava crocetta locality, sited about 1 kilometre to the north-west of the zannona quarry. in this locality it is possible to observe the spalancona palaeosol which is located a few meters below the ground level: a tooth of an undetermined bovine has been collected at the ex cava crocetta locality just above this marker bed. the chronological attribution of the continental deposits exposed at the zannona quarry is primarily based on indirect evidences, in particular geometric relations with older and younger morphostratigraphic or ubs units that crop out extensively in the downstream section of a number of apennine valleys in emilia-romagna between the reno and the montone rivers (see carta geologica d’italia 1:50.000 scale, sheets 221 bologna, 223 ravenna, 239 faenza, 256 rimini). in these localities continental deposits are often bounded at their top by a reddish-brown vetusol, that locally reaches a few meter in thickness, that has been tentatively referred to the upper pleistocene (martelli et al., 2009, p. 59-61). this age is supported by the lack in zannona quarry deposits of lower palaeolithic manufacts that characterize the older apennine foothills palaeo-surfaces up to the “riss cataglacial” (peretto, 1996). to date, only isolated and poorly preserved prehistoric floated manufacts have been collected from the pleistocene palazzone unit. specimens discussed in this study enrich the classical fauna of the early and middle pleistocene largebodied terrestrial vertebrates of the imola region firstly reported by giuseppe scarabelli in the mid ’800, known as “fauna di imola” (see also azzaroli & berzi, 1970; masini et al., 1996 and muttoni et al., 2011, although in the latter publication, the presented field stratigraphy is unreliable). moreover, scarabelli reported of a younger fig. 3 field picture (frontal view) of the cava zannona quarry section running from s (left) to n (right). two main depositional units, unconformably overlying the sabbie gialle fm., are separated by the spalancona palaeosol. fig. 4 stratigraphic log of the cava zannona quarry. rubinato g. et al. 58 deposit “…which i named fluviatile […] consisting primarily of rounded pebbles […] three meters thick…” in which “…apparently no fossil has ever been collected with the exception of isolated horse or bovid teeth…” (scarabelli, 1852). such “fluviatile” deposits were identified by scarabelli in the cover of the alluvial fan terraces of the santerno river (marabini, 2009). such beds, located approximately 15 kilometers north-west of the study area, share important stratigraphic and geographic analogies with the zannona quarry sequence. in fact, both continental successions have been referred to the subsintema di bazzano in the cartografia geologica 1:50.000, servizio geologico d’italia (amorosi et al., 2009). 3. palaeontological remains vertebrate remains collected at the zannona quarry include a proximal portion of a left scapula of equus sp., a frontal with antlers of dama dama, and the incomplete upper right and upper left dental series (from the third premolar to the last molar) of stephanorhinus hemitoechus. all described specimens are deposited at the museo geologico giovanni capellini (mggc) in bologna (italy), and catalogued under mggc accession numbers. the scapula (mggc 21878), which has been collected in situ from the lower gravel layer (figs. 3 and 4), preserves a partially eroded glenoid cavity, the neck and the beginning of the expanded part with the spine, the latter located in proximity of the cranial margin. the specimen collected at cava zannona has a low spine that runs out before the ventral angle and shows no evidence of acromion. the ventral angle shows deep muscular attachments insertions. unfortunately, the scapula does not preserve the coracoid process and the glenoid notch but only the beginning of the supraglenoid tubercle that seems to be extended and placed nearby the articular surface. moreover, the neck of the scapula has an equid-like major length and appears more narrow than other perissodactyls or artiodactyls species (barone, 2006).lacking diagnostic specific traits, overall morphology and size allow to refer the scapula to equus sp. (fig. 6). fallow deer remains are represented by a nicely preserved frontal with antlers (mggc 21871). this specimen was collected in situ in a thin lens of gravel and sand located between the spalancona palaeosol and the vetusol of the zannona quarry terrace (upper gravel layer in figs. 3 and 4), at a depth of about 4 meters below surface. the left antler is the most complete having pedicle, rose, brow tine and beam that leads to the palmation (lister 1990), well-defined and typical of the species dama dama (fig. 7). the distal termination of the palmation is missing; the right antler has only the rose implanted on the pedicle and the initial part of the antler with the brow tine preserved. this specimen is still attached to the pedicle and part of the frontal, and shows all diagnostic features of fallow deer: a very high angle of departure of the beam (150° from the line of pedicle), and basal tines of circular section resting on the rose and making an obtuse angle (115°) with the beam. in addition, the large circumference of the basal tines (left ≈ 95 mm and right ≈ 93 mm) approaching that of the beam (133 mm) is comparable with the middle pleistocene dama dama (lister, 1990; azzaroli, 1953). based on the size and the well-developed morphometric characters the specimen is attributed to an adult individual. a direct comparison with the osteological collection materials at the university of ferrara did not reveal diagnostic morphological differences to support an as fig. 5 field photograph of the spalancona palaeosol. continental vertebrates from zannona quarry (faenza, italy) 59 signment of mggc 21871 to the more primitive species dama clactoniana (or dama dama clactoniana for some authors), which is believed to have gone extinct during mis 9 or mis 8 (di stefano & petronio, 1997). in addition, d. clactoniana is characterized by the presence of three tines on the anterior edge and one tine on the posterior edge, that lacks in the modern individual of d. dama and in the specimen of zannona quarry too (leonardi & petronio, 1976). rhinoceros remains consist of two upper dental series (mggc21872 and 21874). both specimens were not recovered in situ, but they were most likely originally preserved in the same stratigraphic horizon that produced the deer antler. the right maxillary series is complete, whereas the left one is missing the second premolar (figs. 8 and 9). the right p2 has not distal and vestibular cingula. the mesial cingulum is well preserved, continuous and horizontal, whereas the lingual cingulum is wellrendered, continuous but not horizontal; it forms a wedge-shaped constriction next to the median valley between the rear and the front lophe. the lingual cingulum displays the higher degree of variability: where preserved, it is either continuous and horizontal or showing variation in thickness and discontinuous. the right p3 has a well-developed crochet. the protocone constriction, considered as a discriminant character for extinct rhinoceros by lacombat (2005), has not been identified. ectolophe profile is inconstant. the paracone fold is prominent and the metacone fold may be visible. the tooth is similar to the specimen of stephanorhinus hemitoechus from the grotte du mars (de lumley, 1969; lacombat 2005). the same premolar in s. kirchbergensis is characterized by a regular, smooth, slightly convex and without apparent reliefs vestibular wall. the left p3 is incomplete, missing the inner portion of the posterior lophe which includes the hypocone and fig. 6 left scapula of equus sp.(mggc 21878) in distal (a) and lateral (b) views. fig. 7 antler of dama dama (mggc21871) in dorsal view with relative nomenclature. rubinato g. et al. 60 the post-fossette; it is also not possible to distinguish the crochet nor the ante-crochet. the tooth appears symmetrical to the corresponding right one in overall characters, size and wear. it also displays a better preservation, having a prominent and well preserved mesial edge. the right p4 has a preserved crochet, but the posterior and the vestibular cingula are missing. it has a double crochet, a character that has also been detected in specimens of s. hemitoechus from caune de l’arago as well as from grotte du mars (lacombat, 2005). the lack of an ante-crochet, a character observed in this specimen, has been considered as diagnostic for s. hemitoechus by lacombat (2005), with the exception of a specimen from grotta del principe (balzi rossi). the mesial cingulum in s. hemitoechus is well developed, prominent, continuous and horizontal, as in the specimens from the zannona quarry: however, specimens collected from the caune de l’arago and grotta del principe localities lack this character. the lingual cingulum is not preserved but it cannot be excluded that it is a weathering-related artefact. in s. hemitoechus the ectolophe profile is sharply undulated with the paracone fold clearly visible, whereas the metacone fold is visible in some individuals. the vestibular edge profile of the right p4 is undulated with the paracone well-defined and a barely visible metacone. left p4 is significantly worn on the mesial edge of the anterior lophe when compared to the corresponding right tooth; the lingual wall and the median valley are also smoother. overall, the tooth is specular to the its right counterpart. the vestibular wall is only preserved in the mesial section, is missing the metacone fold, and the paracone fold is clearly visible. part of the paracone is also preserved, as well as the lingual and mesial walls of the tooth and the section surrounding the posterior lophe of the distal wall. right m1 is only partially preserved, having a portion of the vestibular wall, a portion of the vestibular paracone fold and possibly the metacone crista. in addition, it is possible to observe the protocone fold in a fragmentary section of the anterior lophe. the left m1 is represented by a portion of the anterior lophe (the paracone is missing) and the vestibular wall whit the metacone fold, the metastyle and the metacone. similarly, diagnostic characters are not discernible in the right m2 except for a prominent and continuous cingulum in the mesial wall. the left m2 is represented by the anterior lophe with preserved protocone constriction, a deep mesial cingulum, the complete vestibular wall (with a clear paracone fold and a shallow metacone fold), and a portion of the posterior lophe. the right m3 has a prominent, continuous, and sub-horizontal cingulum in the anterior lophe; the left m3 has almost complete walls and is missing the inner section of the crochet and part of the mesial labial wall. the mesial cingulum is well-marked and slightly oblique, as observed in s. hemitoechus; the vestibular and lingual cingula are absent. the ectolophe line is very oblique and convex; the paracone line and the distal depression are very shallow. when compared with specimens referred to s. kirchbergensis, the ectolophe profile has a more regular trend; in fact, in merck’s rhinoceros it is commonly possible to identify solely the paracone fold. the overall poor preservation as well as different degrees of molar vs premolar wearing do not allow to clearly identify a number of diagnostic characters in the zannona quarry specimens. the sole observed qualitative character is represented by the ectolophe line, which is strongly undulated and characterized by a welldeveloped paracone line and a noticeable metacone fold. we do exclude an attribution of mggc21872 and 21874 to s. hundsheimensis considering that the latter taxon the ectolophe profile is straight or slightly undulated with a clearly distinguishable paracone fold (the metacone fold is absent). similarly, we refrain from assigning the specimens to s. kirchbergensis, which is charac fig. 8 a: stephanorhinus hemitoechus right maxillary series of teeth in occlusal view (mggc 21874). b: morphological features of the upper teeth in occlusal view. continental vertebrates from zannona quarry (faenza, italy) 61 terized by a slightly undulate profile of the ectolophe and the lack of reliefs. therefore, teeth collected at the cava zannona site are therefore conservatively assigned to stephanorhinus hemitoechus and are believed to represent the palate elements of a single individual. 4. biostratigraphic discussion dama dama is a well-known member of the asian immigrant fauna that spread across europe in the late middle pleistocene: fossil remains have been reported from a number of localities and correlated with the isotopic stages mis 7 and 5 (palombo et al. 2004). specimens recovered from the grotta romanelli (near castro, lecce, italy) and referred to the eemian interglacial by blanc (1953) may represent the sole evidence of postgalerian deer. however, such specimens may be assigned to the more primitive taxon dama clactoniana and thus representative of a previous interglacial stage (sala, 1980). more recent studies on the lithic industries (mussi, 1992; piperno pag. 165 in guidi &piperno, 1992) confirm this hypothesis, placing the lower layers of grotta romanelli before the final stages of the middle pleistocene. the more derived fallow deer dama dama has been reported in several palaeontological sites – all dated to the mis 7 (palombo et al., 2002) – of lazio, such as torre in pietra (caloi & palombo 1978), vitinia (caloi et al., 1983), cerveteri (capasso barbato et al., 1983), casal dei pazzi (anzidei et al., 1984), and is coeval with the primitive subspecies dama dama tiberina (di stefano & petronio, 1997). similarly, the basal deposits of the caverna degli orsi (trieste; berto & rubinato, 2013), san sidero (lecce; de giuli, 1983), and melpignano (lecce; bologna et al., 1994; petronio & pandolfi, 2008) have been referred to the mis 5. the available palaeontological record suggest that fallow deer got extinct in north-eastern italy, including the northern and central adriatic regions, by the end of the isotopic stage 5 (berto & rubinato, 2011), whereas they survived up to the isotopic stage 3 in the more temperate climatic conditions of the tyrrhenian coast and southern italy (sala, 1983), as supported by the finds of grotta della cala (salerno) (benini et al., 1997) and grotta di castelcivita (salerno) (masini & abbazzi, 1997). the rhinoceros stephanorhinus hemitoechus, with all probability an asian immigrant taxon, has been recovered in deposits encompassing the early middle pleistocene-latest pleistocene interval (kahlke & kaiser, 2011). in italy, the oldest record of s. hemitoechus is reported from the faunal unit of silvia, which has been assigned an approximate age of 800.000 years (ambrosetti et al., 1979; gliozzi et al., 1997; bertini et al., 2010): its youngest occurrence is represented by the remains collected at the grotta della cala (salerno) in deposits with an estimated age of 29.850 ±1700 bp (belluomini & bacchin, 1980; benini et al., 1997), thus correlated with the latest mis 3. it is also reported as a component of middle pleistocene faunal assemblages in a number of italian locality such as visogliano (cattani et al., 1991; rubinato, 2011; patrizi, 2012). s. hemitoechus is a mediumto large-sized species characterized by a skull-bearing neutral position significantly lower than other congeneric species from the middle pleistocene, typical of a mixed, low vegetation, pasture behaviour. available data suggest that temperature was not a primary factor in the distribution area of this taxon, although it is more adapted to cooler environments than other coeval congeneric rhinoceros (lacombat, 2005). during relatively cold stages, s. hundsheimensis was replaced by s. hemitoechus in vast areas of the western palaeoartic region. s. hemitoechus survived the extinction of s. hundsheimensis (middle pleistocene) and s. kirchbergensis (early late pleistocene) representing the sole species of the genus in the fossil record. its distribution in relatively dry stages extended over much of peninsular italy, and fossil remains are known from ligurian sites as arma delle manie (savona; fornasiero, 1989), and tyrrhenian localities as castelcivita (salerno; masini & abbazzi, 1997), and grotta della cala (salerno; benini et al., 1997). 5. conclusions the discovery of fossil vertebrates at the zannona quarry locality provides additional data for our comprehension of the environmental and chrono-stratigraphic framework of the continental succession near faenza. pending further radiometric and isotopic dating from the surrounding areas, data presented in this paper allow to fig. 9 stephanorhinus hemitoechus left maxillary series of teeth in occlusal view (mggc 21872). rubinato g. et al. 62 suggest an age for the zannona quarry deposits and fauna. the discussed terrestrial deposits are dated near the middle-late pleistocene boundary and consequently are coeval with the transition between the marine isotopic stage 6 and 5. the fluvial beds bounded upwards by the spalancona palaeosol are here referred to the latest middle pleistocene (mis 6; also in agreement with amorosi et al., 2009). the continental beds above the spalancona palaeosol are interpreted to represent the inland expression of the major transgressive event that characterizes the mis 5. therefore, the equine scapula collected from the coarse, basal deposits can be tentatively referred to the late middle pleistocene. the occurrence of dama dama in the upper interval support the assignment of such deposits to the mis 5: this taxon, in fact, is reported in the adriatic region exclusively from the isotopic stages 7 and 5, both characterized by temperate climatic conditions (berto & rubinato, 2013). correlation with the faenza borehole nearby and the recent proposed stratigraphy of the eastern po plain (amorosi & colalongo, 2005; amorosi et al., 2009), disfavor the presence of mis 7 in the zannona quarry terrestrial deposits. the lack of the rhinoceros species s. kirchbergensis, well adapted to forest and warm environments and diagnostic for the eemian (about mis 5e) interval, does not allow to unequivocally identify the exact age of the studied fauna within a specific warm mis 5 substage. in conclusion, data presented here indicate that the continental deposits exposed at the zannona quarry preserve the transition from the mis 6 and 5. in particular, the spalancona palaeosol separates a lower, braided-stream, mainly coarse-grained interval from an upper, finer, meandering-stream, aggradational flood-plain interval where vertebrate remains support a warm, subarid steppe mis 5 time-slice. acknowledgments we wish to thank mr. renzo vignoli and geom. danilo calesini for the kindness with which they granted, far-back, free access to the excavation of “cava la zannona”. references ambrosetti p., bartolomei g., de giuli c., ficarelli g., torre d. (1979) la breccia ossifera di slivia (aurisina, sistiana) nel carso di trieste. bollettino società paleontologica italiana, 18, 207-220. amorosi a. & colalongo m.l. (2005) the linkage between alluvial and coeval nearshore marine successions: evidence from the late quaternary record of the po river plain, italy. fluvial sedimentology vii, special publications ias 35, 257-275. amorosi a., martini a., severi p. (2009) settore di pianura. in note illustrative della carta geologica d’italia alla scala 1:50000. foglio 239, faenza. ispra, 39-71. antonioli f., ferranti l., fontana a., amorosi a.m., bondesan a., braitenberg c., dutton a., fontolan g., furlani s., lambeck k., mastronuzzi g., monaco c., spada g., stocchi p. (2009) holocene relative sea-level changes and vertical movements along the italian coastline. quaternary international, 221, 37-51. anzidei a.p., bietti a., cassoli p., ruffo m., segre a.g. (1984) risultati preliminari dello scavo in un deposito pleistocenico in località rebibbia-casal de’ pazzi (roma). atti xxiv riunione scientifica dell’istituto italiano di preistoria e protostoria nel lazio, ottobre 1982, 132-139. azzaroli a. (1953) the deer of the weybourne crag and forest bed of norfolk. bull. british museum (natural history). geology 2(1), 1-96. azzaroli a., berzi a. (1970) on an upper villafranchian fauna at imola, northern italy, and its correlation with the marine pleistocene sequence of the po plain. paleontographia italica, 66, 1-12. barone r. (2006) anatomia comparata dei mammiferi domestici. volume primo, osteologia. edizioni edagricole, pp. 690. belluomini g., bacchin p. (1980) datazione di ossa fossili di grotte italiane con il metodo della racemizzazione degli ammino acidi e criterio di distinzione fra reperti esposti e non esposti al riscaldamento. geol. romana 19, 171-180. benini a., boscato p., gambassini p. (1997) grotta della cala (salerno): industrie litiche e faune uluzziane ed aurignaziane. rivista di scienze preistoriche, 48, 37-95. bertini a., ciaranfi n., marino m., palombo m. r., (2010) proposal for pliocene and pleistocene land-sea correlation in the italian area. quaternary international, 219, 95-108. berto c., rubinato g. (2013) the upper pleistocene mammal record from caverna degli orsi (san dorligo della valle-dolina, trieste, italy): a faunal complex between eastern and western europe. quaternary international, volume 284, 7-14. blanc g.a. (1953) la grotte romanelli (terre d’otrante). in: “excursion dans les abruzzes, les poulles, et syr la côte de salerno.” inqua, iv congrés international. roma, pisa, 19-27 août 1953, 35-47. bologna p., di stefano g., manzi g., petronio c., sardella r., sgazzini e. (1994) late pleistocene mammals from the melpignano (le) “ventarole”: preliminary analysis and correlations. bollettino della società paleontologica italiana, 33(2), 265-274. caloi l., cuggiani m.c., palmarelli a., palombo m.r. (1983) la fauna a vertebrati del pleistocene medio e superiore di vitinia (roma). bollettino del servizio geologico d’italia, 102 (1981), 41-76. caloi l., palombo m.r. (1978) anfibi, rettili e mammiferi di torre del pagliaccetto (torre in pietra, roma). quaternaria, 20, 315-428. capasso barbato l., palmarelli a., petronio c. (1983) la mammalofauna pleistocenica di cerveteri (roma). bollettino del servizio geologico d’italia, 102, 77-94. cattani l., cremaschi m., ferraris m.r., mallegni f., masini f., scola v., tozzi c., (1991) le gisement du pléistocène moyen de visogliano (trieste): restes humains, industries, environnement. l’anthropologie, tome 95, 1, 9-36. cremaschi, m. (1987) palaeosols and vetusols in the central po plain (northern italy). a study in quaternary geology and soil development. unicopli, milano, pp. 316. continental vertebrates from zannona quarry (faenza, italy) 63 curzi p., lenaz r., marabini s., vai g.b. (1987) mesostrutture deformative tipo pockmark in un paleosuolo olocenico di romagna. rendiconti della società geologica italiana, 10, 38-40. de giuli c. (1983) le faune pleistoceniche del salento. 1la fauna di san sidero 3. quaderni del museo comunale di maglie, 45-84. di stefano g., petronio c. (1997) origin and evolution of the european fallow deer (dama, pleistocene). n. jb. geol. palaeont. abh., v. 203, 57-75. ferranti l., antonioli f., amorosi a., dai prà g., mastronuzzi g., mauz g., monaco c., orrù p., pappalardo m., radke u., romano p., sansò p., verrubbi v. (2006) elevation of the last interglacial highstand in italy: a benchmark of coastal tectonics. quaternary international, 145-146, 30-54. fornasiero o. (1989) cronostratigrafia di due giacimenti quaternari continentali a mammiferi della liguria. tesi di laurea in scienze geologiche. università degli studi di ferrara, 191 pp. gliozzi e., abbazzi l., argenti p., azzaroli a., caloi l., capasso barbato l., di stefano g., esu d., ficarelli g., girotti o., kotsakis t., masini f., mazza p., mezzabotta c., palombo m.r., petronio c., rook l., sala b., sardella r., zanalda e., torre d. (1997) biochronology of selected mammals, molluscs and ostracods from the middle pliocene to the late pleistocene in italy. the state of the art. rivista italiana di paleontologia e stratigrafia, 103 (3), 369-388. guidi a., piperno m. (1992) italia preistorica. edizioni laterza, roma, pp. 669. kahlke r.-d., kaiser t.m. (2011) generalism and subsistence strategy: advantages and limitations of the highly flexible feeding traits of pleistocene stephanorhinus hundsheimensis (rhinocerotidae, mammalia). quaternary science reviews, 30, 2250-2261. lacombat f. (2005) les rhinocéros fossiles des sites préhistoriques de l’europe méditerranéenne et du massif central. paléontologie et implications biochronologiques. bar, international series 1419, pp. 181. leonardi g., petronio c. (1976) the fallow deer of european pleistocene. geologica romana 16, 1-67. lister a. (1990) critical reappraisal of the middle pleistocene deer species « cervus » elaphoides kahlke. quaternarie, 3-4, 1990, 175-192. lumley h. de (1969) le paléolithique inférieur et moyen du midi méditerranéen dans sons cadre géologique. i: ligurie-provence. gallia préhist. supplém. 5, 1-463. marabini s. (2009) il contributo di giuseppe scarabelli alla conoscenza geologica della pianura imolese. in g.b. vai “il diamante e scarabelli”, 21-30. martelli l., amorosi a., severi p. (2009) note illustrative della carta geologica d’italia alla scala 1:50000. foglio 221, bologna. ispra, pp. 107. masini f., abbazzi l. (1997) l’associazione di mammiferi della grotta di castelcivita. in: gambassini p. (ed.) il paleolitico della grotta di castelcivita, cultura e ambiente. materiae, 5, 33-57. napoli. electa. masini f., abbazzi l., ferretti m., mazza p. (1996) fauna a mammiferi dalle ‘sabbie gialle’ quaternarie di imola. caselecchio (bologna). in: pacciarelli m. & vai g.b. (ed.) i musei civici di imola. la collezione scarabelli. i geologia, 1, 314-326, grafis edizioni, bologna. mussi m. (1992) il paleolitico e il mesolitico in italia. in: popoli e civiltà dell’italia antica, 10. biblioteca di storia patria, roma. muttoni g., scardia g., kent d.v., morsiani e., tremolada f., cremaschi m., peretto c. (2011) first dated human occupation of italy at ~ 0.85 ma during the late early pleistocene climate transition. earth and planetary science letters, 307, 241-252. palombo m.r., azanza b., alberdi m.t. (2002) italian mammal biochronology from the latest miocene to the middle pleistocene: a multivariate approach. geologica romana, 36, 335-368. palombo m.r., milli s., rosa c. (2004) remarks on the biochronology of the late middle pleistocene mammalian faunal complexes of the campagna romana (latium, italy). geologica romana, 37 (2003-2004), 135-143. patrizi g. (2012) i grandi mammiferi della sequenza galeriana del riparo di visogliano (duino, aurisina, trieste): tagli 26-12. tesi di laurea magistrale in quaternario, preistoria e archeologia, università degli studi di ferrara, anno acc. 2010-2011, pp. 113. peretto c. (1996) il paleolitico del territorio bolognese: considerazioni sulla tipologia e sulla cronologia delle industrie litiche. in “lettere di pietra”. i depositi pleistocenici: sedimenti, industrie e faune del margine appenninico bolognese. editrice compositori, bologna (1996), 7-18. petronio c., pandolfi l. (2008) stephanorhinus hemitoechus (falconer, 1868) del pleistocene superiore dell’area di melpignano-cursi e s. sidero (lecce, italia). geologica romana, 41, 1-12. rubinato g. (2011) i grandi mammiferi della sequenza galeriana dal taglio 45 al taglio 29 del riparo di visogliano (duino-aurisina, trieste). tesi di laurea magistrale in quaternario, preistoria e archeologia, università degli studi di ferrara, anno acc. 2010-2011, pp. 131. sala b. (1980) faune a grossi mammiferi nel pleistocene superiore. in: i vertebrati fossili italiani. catalogo della mostra. verona, 235-238. sala b. (1983) variations climatiques et sequences chronologiques sur la base des variations des associations fauniques a grands mammifères. rivista sc. preistoriche, 38 (1-2), 161-180. sanchez-goñi m.f., eynaud f., turon j.l., shackleton n.j. (1999) high resolution palynological correlation of the iberian margin: direct land-sea correlation for the last interglacial complex. earth and planetary science letters, 171, 123-137. scarabelli g. (1852) sopra i depositi quaternari dell’imolese. rettifica di alcune opinioni intorno alla giacitura delle ossa fossili. annali di scienze matematiche e fisiche, 3, 33-41. ms. received: october 22, 2012 final text received: april 18, 2013 << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /all /binding /left /calgrayprofile (gray gamma 2.2) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /warning /compatibilitylevel 1.4 /compressobjects /tags /compresspages true /convertimagestoindexed true /passthroughjpegimages true /createjobticket false /defaultrenderingintent /default /detectblends true /detectcurves 0.1000 /colorconversionstrategy /leavecolorunchanged /dothumbnails false /embedallfonts true /embedopentype false /parseiccprofilesincomments true /embedjoboptions true /dscreportinglevel 0 /emitdscwarnings true /endpage -1 /imagememory 1048576 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documenti pdf creati possono essere aperti con acrobat e adobe reader 5.0 e versioni successive.) /enu (use these settings to create adobe pdf documents suitable for reliable viewing and printing of business documents. created pdf documents can be opened with acrobat and adobe reader 5.0 and later.) >> >> setdistillerparams << /hwresolution [1200 1200] /pagesize [396.850 566.929] >> setpagedevice amq abs monegato ravazzi tepro 225-229.pub available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 225 229 the late pleistocene multifold glaciation in the alps: updates and open questions giovanni monegato 1, cesare ravazzi 2 1 istituto di geoscienze e georisorse, cnr, padova, italy 2 istituto per la dinamica dei processi ambientali, cnr, milano, italy corresponding author: g. monegato <giovanni.monegato@igg.cnr.it> abstract: the stratigraphic record of late pleistocene glaciations in the alps is well defined for the last glacial maximum (lgm) thanks to recent chronological and stratigraphic studies. these allowed to compare the spread of the glaciers to the global climate models for the lgm, whereas, the amplitude of glacial advances in the pre-lgm late pleistocene needs further investigation in chronostratigraphic archives, with emphasis on the dynamics of alpine glaciers during cold stages mis5d, mis4, and the several mis3 stadials. in this perspective, the stratigraphic archives bearing finite ages close to the radiocarbon method limit could be tested for improvements of the available chronological methods. keywords: late pleistocene, alps, glaciations 1. introduction according to the isotopic record from ice-cores, the late pleistocene was marked by at least four major cold stages (mis5d, mis5b, mis4 and mis2, the latter culminating in the last glacial maximum, lgm). the global lgm is a climate-stratigraphic concept defined as the last period framed in the last glaciation when global ice sheets reached their maximum integrated volume, currently between 27 and 19 ka bp (clark et al., 2009) or 30 and 17 ka bp (lambeck et al., 2014). recent climate-models investigated the interaction among atmospheric circulation, oceanic circulation and ice-sheet waxing (e.g., beghin et al., 2015; liakka et al., 2016). first lgm proxy reconstructions in the alps allowed first validation of these models (luetscher et al., 2015). in the alps, recent stratigraphic investigations expanded the dataset of the late pleistocene glacial events, especially the time constrains for glacier spread during the lgm. the development of alpine valley glaciers during the pleistocene has been the topic of a large number of studies since the 19th century and especially after the milestone work by penck & brückner (1909), in which the multi-glaciation theory was illustrated. during the 20th century the application of this subdivision acted as a postulate, adopted in all the stratigraphic works within the alpine realm, including geological mapping. only after bowen (1978) and šibrava (1986) this subdivision was suggested to be abandoned and substituted by an array of stratigraphic approaches including allo-, chrono-, bio and isotopic stratigraphy. the development of dating methods in the last forty years improved the chronological assessment of glacial units, especially for those related to the lgm and those marked by a reverse paleomagnetic signal. 2. historical background in the alps, the last glacial cycle has been related to the würm glaciation (penck & brückner, 1909) and its three-phases subdivision formalized by reference sections and type localities of regional value in the austrian alps (chaline & jerz, 1984; see also spötl et al., 2013). this regional scheme distinguishes the “lower” (broadly encompassing the post-eemian mis5), the “middle” (mis4 and 3) and the “upper” würm (mis 2). the designation of stratotypes and / or reference sections and type localities for continental units is prescribed by the international stratigraphic code currently in use (murphy and salvador, 1998). however, until recent times, the use of this alpine regional stratigraphy in correlating end-moraine systems was mostly supported by criteria based on field properties of weathering profiles. these field criteria were poorly checked by laboratory calibration analysis, while their chronological implications were poorly tested by independent dating methods. finally, most of the field weathering profile criteria failed the proof of geochronometric dating. indeed, several glacial bodies forming the italian end-moraine systems, identified by their weathering profiles, and classified into several distinct middle or late pleistocene “glaciations” (e.g. venzo, 1965; 1977; petrucci, 1970; bini & zuccoli, 2004) were resettled to the lgm whenever radiometric dating has been successfully applied (ravazzi et al., 2014; gianotti et al., 2015; monegato et al., 2017; ivy-ochs et al., in press). it turned out that the largest end-moraine systems, formed during the lgm at the italian fringe, consist of several acme moraine complexes staked by millennial climate events (monegato et al., 2017; see fig. 1). further investigation is needed in other large end-moraine systems including glacial units ascribed to middle pleistocene on the base of weathering profiles (e.g. the besnate allogroup in the ticino and https://doi.org/10.26382/aiqua.2018.aiquaconference adda rivers glacial systems, bini et al., 2004). 3. recent updates of the upper pleistocene units in the alps regarding the three subdivisions of the würm glaciation, in the austrian stratotype of baumkirchen the upper würm onset, marked by the advance of the inn glacier over the middle inn valley, was recently chronologically constrained at 32-33 ka cal bp (spötl et al., 2013). at the same site, the occurrence of lower-middle würm advances has been investigated in recent years (barrett et al., 2017). studies on lacustrine records around the alps yielded climatic and environmental information which show an overall agreement with glacier build-ups before lgm, i.e. during mis5d and mis4, but also mis3 stadials (drescher-schneider et al., 2000; 2007). the sedimentary traces of advances predating the upper würm are scattered and scarce in some sectors (fig. 1). in the austrian sector of the alps a few outcropping sections and core records document upper pleistocene pre-lgm glacial and glaciolacustrine deposits (starnberger et al., 2013; barrett et al., 2017). in the swiss sector of the alps the occurrence of three different advances was highlighted in the definition of birrfeld glaciation (e.g., preusser et al., 2011; buechi et al., 2017) through osl and radiocarbon dating on glaciofluvial and glaciolacustrine deposits. as in the austrian part, the lower-middle würm advances were recognized in cores and stratigraphic sections generally buried by the lgm deposits, whereas moraines of relevant age were not documented in piedmont amphitheaters. on the italian side of the alps, pre-lgm cold / continental phases are represented by subtle alluvial sediment piles in the late pleistocene lower plain successions (pini et al., 2009; hippe et al., 2018), suggesting a scarce sedimentary delivery from the mountains or, alternatively, that most of the deposits related to cold stages were stored within the valleys. in the friulian piedmont plain the valeriano creek succession, related 226 fig. 1 schematic overview of the temporal development of the extent of the glaciers from the alpine core massifs (pale blue) and external massifs (dark blue) compared to the stratigraphic ranges of important and well dated würm palaeoclimatic, sedimentary and palaeoenvironmental archives (vertical bars) in the alps and their foreland (see also mayr et al., 2017). western alps (in blue): 1) north grésivaudan (guiter et al., 2008), 2) les echets (de beaulieu & reille, 1984). northern alpine sector (in grey): 1) baumkerchen (spötl et al., 2013; barrett et al., 2017), 2) unteragenberg (starnberger et al., 2013), 3) gossau (preusser et al., 2003), 4) hopfgarten and kitzbüel (reitner & draxler, 2002), 5) nesseltalgraben (mayr et al., 2017), 6) samerberg (grüger, 1979), 7) thalgut (preusser & schlüchter, 2004), 8) mondsee (drescher-schneider, 2000), 9) niederweningen (dehnert et al., 2012), 10) füramoos (müller et al., 2003), 11) jammertal (müller, 2000). southern alpine sector (in red): 1) albeins (fliri, 1971), 2) spormaggiore (avanzini et al., 2012), 3) vilminore (unpublished data), 4) valeriano (monegato et al., 2010), 5) garda and tagliamento (monegato et al., 2007, 2017), 6) castelnovate (orombelli, 1986), 7) fimon (monegato et al., 2011), 8) casaletto ceredano (ravazzi et al., 2018), 9) piancada (hippe et al., 2018), 10) azzano decimo (pini et al., 2009). the stacked northern atlantic 18o record from benthic foraminifera and the marine isotope stages (mis; from lisiecki and raymo 2009) are shown for comparison. monegato g., ravazzi c. 227 to a small foothill catchment, shows gravel aggradation during the mis5d, and, after fine-grained deposition ascribed to mis5c-a, another coarse-grained unit occurs before 36.0±2.2 cal ka bp (monegato et al., 2010). similar situations, with ages close to the radiocarbon method limit, are reported for the ticino system in the alpine foreland (castelnovate site, orombelli, 1986). these sites indicate active aggradation of fluvial systems belonging to glaciated catchments at least during cold phases of mis3. 4. the lgm record and inferences on global circulation models the culminations occurring in the late würm are now commonly associated to the lgm thanks to a robust chronology available for several sector of the alps including end-moraine systems (e.g., monegato et al., 2007, 2017; ivy-ochs et al., 2008; ravazzi et al., 2012; federici et al., 2016) and the related outwash plains (fontana et al., 2010). the spread of the alpine glaciers reached its maximum at about 26-24 ka (fig. 1) in correspondence to the insolation minimum (laskar et al., 2004) and the greenland stadial 3 (andersen et al., 2006), considered to be the peak in global ice volume (hughes and gibbard, 2015). comparing the lgm development of alpine glaciers to the waxing of the boreal ice-sheets, it is interesting the in-phase relationship with the north american ice-sheet (nais) at 26-24 ka. according to the atmospheric circulation models (e.g., beghin et al., 2015; liakka et al., 2016) the topography of the nais controlled the circulation and the development of the european ice-sheets, including mountain glaciers (monegato et al., 2017). according to these models, during the mis5b and mis4 the european icesheet experienced a larger expansion towards the north, due to the lesser extension of the nais and the circulation track delivering moisture northwards. during these phases, the alps were mostly interested by westerlies and the glaciers of the western french alps likely reached sizes similar to the lgm ones. different circulation tracks could have meant changes in distribution of the precipitations in the alps, with consequence of spread of local glaciers, especially in the forealpine sector and the western french alps, where elevated plateaus could have developed large glaciers during prelgm cold phases. this possible large extension of glaciers in the western alps has been modeled by seguinot et al. (2018), but sedimentary evidence needs to be confirmed, starting from those sections where wood remnants are dated close to the radiocarbon limit. acknowledgements the authors are grateful to giuseppe orombelli and paolo mozzi for their essential comments. references andersen k., svensson a., johnsen s., rasmussen s., bigler m., rothlisberger r., ruth u., siggaardandersen m., steffensen j., dahl-jensen d., vinther b., clausen h. (2006) the greenland ice core chronology 2005, 15-42 ka. part 1: constructing the time scale. quaternary science reviews, 25, 3246-3257. avanzini m., bargossi g.m., borsato a., cucato m., morelli c., picotti v., selli l. (2012) note illustrative della carta geologica d’italia alla scala 1:50.000, foglio 043 mezzolombardo. lts land technology & services, pp. 250. barrett s. j., starnberger r., tjallingii r., brauer a., spötl c. (2017) the sedimentary history of the inner-alpine inn valley (austria): extending the baumkirchen type section further back in time with new drilling. journal of quaternary science, 32, 63 -79. beghin p., charbit s., dumas c., kageyama m., ritz c. (2015) how might the north american ice sheet influence the northwestern eurasian climate?. climate of the past, 11, 1467-1490. bini a., zuccoli, l. (2004) prime note sul rilevamento dell’anfiteatro del garda: metodi e unità provvisorie. il quaternario 17, 333-342. bini a., zuccoli l., bussolini c., corbari d., da rold o., ferliga c., rossi s., viviani c. (2004) glacial history of the southern side of the central alps, italy. in: ehlers j., gibbard p.l. (eds), quaternary glaciations extent and chronology, elsevier, amsterdam, 195-200. bowen d. g. (1978) quaternary geology: a stratigraphic framework for multidisciplinary work. oxford, new york: pergamon. pp. 221. buechi m.w., graf h.r., haldimann p., lowick s.e., anselmetti f. (2017) multiple quaternary erosion and infill cycles in overdeepened basins of the northern alpine foreland. swiss journal of geosciences, 111, 133-167. chaline j., jerz h. (1984) arbeitsergebnisse der subkommission für europäische quartärstratigraphie. stratotypen des würm-glazials. eiszeitalter und gegenwart, 35, 185-206. clark p.u., dyke a.s., shakun j.d., carlson a.e., clark j., wohlfarth b., mitrovica j.x., hostetler s.w., mccabe a.m. (2009) the last glacial maximum. science, 325, 710-714. de beaulieu j.l., reille m. (1984) a long upper pleistocene pollen record from les echets, near lyon, france. boreas, 13, 111-132. dehnert a., lowick s.e., preusser f., anselmetti f.s., drescher-schneider r., graf h.r., heller f., horstmeyer h., kemna h.a., nowaczyk n.r., züger a., furrer h. (2012) evolution of an overdeepened trough in the northern alpine foreland at niederweningen, switzerland. quaternary science reviews, 34, 127-145. drescher-schneider r. (2000) klimaentwicklung im riss/würm interglazial (eem) und frühwürm in den ostalpen. in: husen, d. (ed.), mitteilungen der kommission für quartärforschung. osterreichische akademie der wissenschaften 12, 39-92. drescher-schneider r., jacquat c., schoch w. (2007) palaeobotanical investigations at the mammoth alpine late pleistocene multifold glaciation site of niederweningen (kanton zürich), switzerland. quaternary international, 164-165, 113-129. federici p.r., ribolini a., spagnolo m. (2016) the glacial history of the maritime alps from the last glacial maximum to the little ice age. geological society of london special publications, 433, sp433-sp439. fliri f. (1988) die schottergrube von albeins bei brixen, eine neue schlüsselstelle zur kenntnis der chronologie der würmvereisung in südtirol. zeitschrift für gletscherkunde und glazialgeologie 24, 137-142. fontana a., mozzi p., bondesan a. (2010) late pleistocene evolution of the venetian-friulian plain. rendiconti lincei, 21 (suppl.1), 181-196. gianotti f., forno m.g., ivy-ochs s., monegato g., pini r., ravazzi c. (2015) stratigraphy of the ivrea morainic amphitheatre (nw italy): an updated synthesis. alpine and mediterranean quaternary, 28, 29-58. grüger e. (1979) die seeablagerungen vom samerberg/obb. und ihre stellung und ihre stellung im jungpleistozän. eiszeitalter und gegenwart, 29, 23 -34. hippe k., fontana a., hajdas i., ivy-ochs s. (2018) a high-resolution 14c chronology tracks pulses of aggradation of glaciofluvial sediment on the cormor megafan between 45 and 20 ka bp. radiocarbon, doi:10.1017/rdc.2018.21 hughes p.d., gibbard p.l. (2015) a stratigraphical basis for the last glacial maximum (lgm) quaternary international, 383, 174-185. ivy-ochs s., kerschner h., reuther a., preusser f., heine k., maisch m., kubik p.w., schlüchter c. (2008) chronology of the last glacial cycle in the european alps. journal of quaternary science, 23, 559-573. ivy-ochs s., lucchesi s., baggio p., fioraso g., gianotti f., monegato g., graf a., akçar n., christl m., carraro f., forno m.g., schlüchter c. (in press) new geomorphological and chronological constraints for glacial deposits in the rivoliavigliana end-moraine system and the lower susa valley (western alps, nw italy). journal of quaternary science. laskar j., robutel p., joutel f., gastineau m., correia a.c.m., levrard b.a. (2004) long-term numerical solution for the insolation quantities of the earth. astronomy and astrophysics, 428, 261-285. liakka j., löfverström m., colleoni f. (2016) the impact of the north american glacial topography on the evolution of the eurasian ice sheet over the last glacial cycle. climate of the past, 12, 12251241. lisiecki l.e., raymo m.e. (2009) diachronous benthic δ18o responses during late pleistocene terminations. palaeoceanography, 24, pa3210. doi:10.1029/2009pa001732 luetscher m., boch r., sodemann h., spötl c., cheng h., edwards r. l., frisia s., hof f., müller w. (2015) north atlantic storm track changes during the last glacial maximum recorded by alpine speleothems. nature communications. doi: 10.1038/ncomms7344. mayr c., brandlmeier b., diersche v., stojakowits p., kirscher u., matzke-karasz r., bachtadse v., eigler m., haas u., lempe b., reimer p.j., spötl c. (2017) nesseltalgraben, a new reference section of the last glacial period in southern germany. journal of paleolimnology, 58, 213-229. monegato g., ravazzi c., donegana m., pini r., calderoni g., wick l. (2007) evidence of a twofold glacial advance during the last glacial maximum in the tagliamento end moraine system (eastern alps). quaternary research, 68, 284-302. monegato g., lowick s.e., ravazzi c., banino r., donegana m., preusser f. (2010) middle to late pleistocene chronology and palaeoenvironmental evolution of the south-eastern alpine foreland: the valeriano creek succession (ne italy). journal of quaternary science, 25, 617-632. monegato g., pini r., ravazzi c., reimer p., wick l. (2011) correlating alpine glaciation with adriatic sea-level changes through lake and alluvial stratigraphy. journal of quaternary science, 26, 791804. monegato g., scardia g., hajdas i., rizzini f., piccin a. (2017) the alpine lgm in the boreal ice-sheets game. scientific reports, 7(1), 2078. müller u.c., pross j., bibus e. (2003) vegetation response to rapid change in central europe during the past 140,000 yr based on evidence from the füramoos pollen record. quaternary research, 59, 235-245. murphy m.a., salvador a. (eds. 1998) international stratigraphic guide an abridged version. episodes, 22 (4), 255-271. orombelli g. (1986) nuove datazioni 14c per il quaternario superiore delle alpi centrali. natura bresciana, 23, 343-346. penck a., brückner e. (1909) die alpen im eiszeitalter. tauchnitz; leipzig, pp. 1199. petrucci f. (1970) rilevamento geomorfologico dell’anfiteatro morenico di rivoli-avigliana. memorie della società italiana di scienze naturali, 18, 95 -124. pini r., ravazzi c., donegana m. (2009) pollen stratigraphy, vegetation and climate history of the last 215 ka in the azzano decimo core (plain of friuli, north-eastern italy). quaternary science reviews, 28, 1268-1290. preusser f., schlüchter c. (2004) dates from an important early late pleistocene ice advance in the aare valley, switzerland. eclogae geologicae helvetiae, 97, 245-253. preusser f., geyh m.a., schlüchter c. (2003) timing of late pleistocene climate change in lowland 228 monegato g., ravazzi c. switzerland. quaternary science reviews, 22, 1435-1445. preusser f., graf h. r., keller o., krayss e., schlüchter c. (2011) quaternary glaciation history of northern switzerland. e&g quaternary science journal, 60, 282-305. ravazzi c., badino f., marsetti d., patera g., reimer p.j. (2012) glacial to paraglacial history and forest recovery in the oglio glacier system (italian alps) between 26 and 15 kyr cal bp. quaternary science reviews, 58, 146-161. ravazzi c., pini r., badino f., de amicis m., londeix l., reimer p. (2014) the latest lgm culmination of the garda glacier (italian alps) and the onset of glacial termination. age of glacial collapse and vegetation chronosequence. quaternary science reviews, 105, 26-47. ravazzi c., garozzo l., deaddis m., de amicis m., marchetti m., pini r., vezzoli g., zanchi a. (2018) palaeoenvironment and vegetation history in the central po plain (northern italy) between 33 -30 ka cal bp under the impact of millennial climate change. alpine mediterranean quaternary, 31, quaternary: past, present, future aiqua conference, florence, 13-14/06/2018, 93-97. doi: 10.26382/aiqua.2018.aiquaconference reitner j., draxler i. (2002) die klimatisch-fazielle entwicklung vor dem würm-maximum im raum kitzbühel st. johann hopfgarten (nordtirol/ österreich). terra nostra, 6, 298-304. seguinot j., jouvet g., huss m., funk m., ivy-ochs s., preusser f. (2018) modelling last glacial cycle ice dynamics in the alps, the cryosphere discuss. doi: 10.5194/tc-2018-8, in review. šibrava v. (1986) correlation of european glaciations and their relation to the deep sea record. quaternary science reviews, 5, 433-441. spötl c., reimer p.j., starnberger r., reimer, r.w. (2013) a new radiocarbon chronology of baumkirchen, stratotype for the onset of the upper wüurmian in the alps. journal of quaternary science, 28, 552-558. starnberger r., drescher-schneider r., reitner j.m., rodnight h., reimer p.j., spötl c. (2013) late pleistocene climate change and landscape dynamics in the eastern alps: the inner-alpine unterangerberg record (austria). quaternary science reviews, 68, 17-42. venzo s. (1965) rilevamento geologico dell’anfiteatro morenico frontale del garda dal chiese all’adige. mememorie società italiana di scienze naturali, 14, 1-82. venzo s. (1977) i depositi quaternari e del neogene superiore nella bassa valle del piave da quero al montello e del paleopiave nella valle del soligo (treviso). memorie degli instituti mineralogia e geologia dell’università di padova, 30, 1-64. 229 alpine late pleistocene multifold glaciation ms. received: may 7, 2018 final text received: may 18, 2018 230 base nuovi dati stratigrafici e cartografici delle unità quaternarie del foglio 438 "bari" (puglia italia meridionale) luigi spalluto1, piero pieri1-3, luisa sabato1-2 & marcello tropeano1-2 1dipartimento di geologia e geofisica, bari 2centro interdipartimentale di ricerca per il rischio sismico e vulcanico, bari 3via pisana 313, 50143 firenze corresponding author: l. spalluto <l.spalluto@geo.uniba.it> riassunto: spalluto l. et al., nuovi dati stratigrafici e cartografici delle unità quaternarie del foglio 438 "bari" (puglia italia meridionale). (it issn 0394-3356, 2010). i nuovi rilevamenti geologici condotti per la realizzazione del foglio 438 “bari” (scala 1:50 000) nell’ambito del progetto carg hanno permesso di definire un dettagliato quadro stratigrafico delle unità quaternarie affioranti nell'area che differisce in modo sostanziale da quello presente nella precedente cartografia geologica ufficiale (carta geologica d'italia alla scala 1:100 000, foglio 177 "bari" e foglio 178 "mola di bari"). l'area di bari ricade sul versante adriatico delle murge, in puglia, dove le unità affioranti possono essere schematicamente suddivise in: unità del substrato cretacico (non descritte in questo lavoro), appartenenti ad una antica piattaforma carbonatica mesozoica, e unità delle coperture pleistoceniche (oggetto di questo lavoro), corrispondenti a sottili e discontinui depositi di ambienti variabili dal continentale al marino di piattaforma. nel nuovo rilevamento l’attenzione posta nell’individuazione e nell’analisi delle superfici di discontinuità e nello studio sedimentologico delle facies presenti ha permesso di confermare, come già intuito da precedenti autori, che i depositi quaternari sono riferibili a diverse fasi deposizionali e di distinguere numerose unità sia di tipo litostratigrafico (calcarenite di gravina ed argille subappennine) che di tipo ubsu (supersintema delle murge e supersintema delle lame delle murge, suddivisi in sintemi); in precedenza (foglio 177 “bari” e foglio 178 “mola di bari” della carta geologica d’italia in scala 1: 100 000) tali unità erano riferite a due sole formazioni (tufi delle murge ed argille di rutigliano). la nuova stratigrafia del quaternario si inserisce bene nel quadro delle conoscenze sull’evoluzione regionale dell’area. la calcarenite di gravina e le argille subappennine, deposte in continuità di sedimentazione, testimonierebbero la fase di ingressione marina associata a subsidenza tettonica durante il pliocene superiore-pleistocene inferiore, mentre i due supersintemi ed i relativi sintemi testimonierebbero la fase di regressione associata al sollevamento regionale durante il pleistocene medio-superiore. abstract: spalluto l. et al., new stratigraphic and cartographic data from the quaternary units of the 438 sheet “bari”. (it issn 0394-3356, 2010). a new geological survey was carried out in order to create the 438 sheet “bari”, which is part of the national carg (cartografia geologica) project whose aim is to produce the geological map of italy at the scale 1:50 000. the 438 sheet “bari" represents an area located in a coastal sector of the murge region in apulia (southern italy), and its stratigraphy is quite simple: on a cretaceous bedrock, made up of limestones belonging to a mesozoic carbonate platform (not of interest for this work), plio-plestocene sedimentary covers disconfomably and discontinuosly lie. as regards these sedimentary covers, obtained data led us to propose a new lithostratigraphic subdivision which differs from the formal one utilized in the previous geological maps referred to the same area (177 sheet “bari" and 178 sheet “mola di bari" at the scale 1:100 000). in greater detail, the plio-pleistocene deposits cropping out in the studied area were formerly included and classified in two formations (tufi delle murge and argille di rutigliano fms), locally pleistocene in age. tufi delle murge fm. is here referred partly to the calcarenite di gravina fm. (late pliocene ? early pleistocene in age) and to 4 of the 5 terraced synthems of the murge supersynthem (middle-late pleistocene in age). argille di rutigliano fm. is here referred partly to argille subappennine fm. (early pleistocene) and to the rutigliano synthem of the murge supersynthem. terraced alluvial deposits of the lame delle murge supersynthem complete the stratigraphic framework of quaternary units in the area of the map 438 sheet “bari”. calcarenite di gravina fm. and argille subappennine fm. represent the sedimentary succession conformably deposited during the wellknown regional tectonic subsidence phase occurred during late pliocene-early pleistocene times in the bradanic trough. this succession is locally marked by the gradual change from shallow-water carbonate sedimentation (calcarenite di gravina fm.) to deep-water emipelagic sedimentation in outer shelf environments (argille subappennine fm.). the five synthems of the murge supersynthem mark the gradual emersion of this sector of the apulian foreland during the regional tectonic uplifting. synthems represent the sedimentary expression of the general regressive trend produced by the interaction between tectonic uplift and glacio-eustatic sea-level changes. the regressive trend is also suggested by the irregular deepening of main karstic canyons (locally named lame), recording alternating phases of linear incision and deposition resulting in the deposition of the alluvial terraced deposits, locally mapped as synthems, belonging to the lame delle murge supersynthem. parole chiave: cartografia geologica del quaternario, bari, murge, puglia. keywords: geological mapping of quaternary units, bari, murge, apulia. il quaternario italian journal of quaternary sciences 23(1), 2010 3-14 1. introduzione nell’ambito del progetto carg puglia, i l dipartimento di geologia e geofisica dell’università di bari è stato incaricato di realizzare il foglio 438 “bari” (scala 1: 50 000). i lavori di rilevamento sono cominciati nel 2003 coordinati da piero pieri e luisa sabato e diretti da giustino ricchetti e marcello tropeano. i rilevamenti sono stati eseguiti da giorgio de giorgio, vincenzo de santis, michele labriola, gaetano lotito, piero pieri, luigi spalluto e clemente zoppi. le analisi biostratigrafiche sono state compiute da mauro caffau 4 l. spalluto et al. e da maria marino. il territorio compreso nel foglio è situato lungo il versante adriatico delle murge centro-settentrionali (fig. 1) ed in esso ricade tutta l'area metropolitana della città di bari e parte della sua provincia, comprendendo il tratto di costa tra gli abitati di giovinazzo e torre a mare e spingendosi nell’entroterra barese fino ai primi rilievi posti a quote di poco superiori ai 200 metri (dintorni di grumo appula) (fig. 2). in quest'area, come in tutta l'area delle murge, affiora una spessa successione cretacea di calcari di piattaforma su cui giacciono in discordanza lembi di depositi plio-pleistocenici di modesto spessore (pieri, 1980). i lavori di rilevamento geologico del foglio (al momento in fase di allestimento per la stampa) hanno messo in evidenza notevoli differenze fra la cartografia geologica ufficiale e la nuova cartografia prodotta nell'ambito del carg puglia, foglio 438 "bari" (pieri et al., in prep.). poiché i dati ricavati dal nuovo rilevamento hanno permesso di offrire un dettagliato quadro stratigrafico-deposizionale delle unità affioranti, alcuni dei partecipanti al progetto, per i loro settori di competenza, si sono impegnati a proporre una serie di note sintetiche su riviste di settore che illustrino parte delle novità introdotte nel foglio 438 "bari" rispetto alla cartografia geologica ufficiale relativa alla stessa area. il presente lavoro si inquadra in questa iniziativa ed illustra la nuova suddivisione stratigrafica delle unità quaternarie proposta nel foglio 438 “bari”, sottolineando i motivi che hanno determinato alcune scelte, i criteri stratigrafici utilizzati ed il significato da attribuire a queste unità. per quanto riguarda invece la revisione della stratigrafia della successione mesozoica, si rimanda ad altre note simili proposte in precedenza (spalluto et al., 2005; 2008). la nuova classificazione dei depositi quaternari affioranti sul versante adriatico delle murge si avvale del riconoscimento delle superfici di discontinuità per la cartografia delle unità a limiti inconformi (ubsu). lo studio di tali superfici, abbinato all’analisi di facies dei depositi quaternari, ha permesso di distinguere i depositi relativi a più fasi deposizionali e di ricostruire un assetto stratigrafico che testimonia l'evoluzione geologica della regione durante il quaternario. 2. conoscenze stratigrafiche precedenti al fine di illustrare il nuovo quadro stratigrafico relativo alle unità quaternarie proposto nel foglio 438 "bari", risulta opportuno tratteggiare brevemente le principali tappe della evoluzione delle conoscenze geologico-stratigrafiche riferite ai depositi plio-pleistocenici affioranti nell'area. nel quadro geologico dei fogli 177 "bari" e 178 "mola di bari" della precedente edizione della carta geologica d'italia alla scala 1:100 000 e delle relative note illustrative (azzaroli & valduga, 1967), le unità quaternarie in facies marina vengono riferite al “complesso calcareo detritico trasgressivo” e sono rappresentate dal basso verso l'alto da: “tufi delle murge” (pleistocene), “argil le di rutigliano” (pleistocene) e “depositi costieri” (olocene) (tab. 1). i depositi in facies continentale vengono invece attribuiti ad un’unica unità che comprende tutte le alluvioni antiche (terrazzate) ed attuali affioranti in corrispondenza dei principali corsi d’acqua. l'unità quaternaria maggiormente rappresentata nei fogli citati è quella dei tufi delle murge alla quale veniva sostanzialmente attribuito il significato di una successione di depositi terrazzati digradanti verso il mare adriatico e progressivamente più recenti spostandosi dai lembi posti a quota più elefig. 1 inquadramento del foglio 438 “bari” in una carta geologica sintetica dell’area delle murge. setting of the 438 sheet “bari” in a synthetic geologic map of the murge area. vata verso quelli prossimi alla linea di costa. tale interpretazione, derivante da uno schema di distribuzione dei depositi terrazzati quaternari lungo la penisola italiana proposto da selli (1962) (nel quale i depositi del versante adriatico delle murge venivano riferit i al milazziano), discordava da una più articolata sintesi regionale fornita in precedenza da d'erasmo (1934). quest'ultimo, considerando una evoluzione sostanzialmente simile per i fianchi opposti delle murge (versante bradanico e versante adriatico), riconosceva la presenza di un mantello di sedimenti calcarei (tufo o tufo calcareo) e marnoso-argillosi, depositatisi in seguito ad una trasgressione marina durante il pliocene e conservatisi in lembi residui; su tale mantello di sedimenti, per un "successivo movimento di regressione" del mare ("un sollevamento del fondo marino avvenuto dopo la sedimentazione delle argille"), si depositavano sedimenti prevalentemente sabbiosi di ambiente litorale (d'erasmo, 1934). si deve ad un più recente lavoro di iannone & pieri 5nuovi dati stratigrafici e cartografici ... (1979) una revisione critica del termine “tufi calcarei” utilizzato sia formalmente che informalmente nell'area murgiana. sostanzialmente, la gran parte dei depositi classif icati da azzaroli & valduga (1967) nella formazione dei tufi delle murge viene attribuita da iannone & pieri (1979) alla calcarenite di gravina (sensu azzaroli 1968) che segna l'inizio del ciclo sedimentario di avanfossa (fossa bradanica) sul lato occidentale e settentrionale delle murge. tale collocazione stratigrafica, che ricorda la sintesi di d'erasmo (1934), spinge gli autori a considerare la calcarenite di gravina come il primo termine trasgressivo del ciclo della fossa bradanica su tutta l'area delle murge, compreso quindi il lato adriatico. va qui ricordato che in precedenza pieri (1975), proprio nell'area di bari, aveva riconosciuto la presenza di più unità terrazzate in discordanza sui termini calcarenitici; tale distinzione, pur se non sottolineata dall'autore, evidenziava quindi come nel termine formale di "tufi delle murge" (sensu azzaroli & valduga, 1967) fossero state accorpate unità stratigrafiche con significato differente. nel contesto di revisione proposto da iannone & pieri (1979) trovano collocazione anche le argille di rutigliano che vengono attribuite alla formazione delle argille subappennine, definite sul versante occidentale delle murge da azzaroli et al. (1968) come l'unità stratigrafica che si sovrappone alla calcarenite di gravina nel ciclo bradanico e che rappresenterebbe l'ulteriore approfondimento del bacino anche sul versante adriatico delle murge. nella carta geologica delle murge e del salento e nella relativa nota illustrativa (ciaranfi et al., 1988) viene distinta nell'area di bari la calcarenite di gravina da una serie di depositi marini terrazzati cartografati però in maniera estremamente schematica e senza distinzione di ordine, sia a causa della scala utilizzata sia soprattutto per l'assenza di informazioni stratigrafiche di dettaglio. 3. stratigrafia delle unità quaternarie nel foglio 438 "bari" il quadro geologico proposto nel foglio 438 "bari" è relativamente semplice, e nelle sue linee essenziali, può essere sintetizzato come segue: sui calcari cretacei di piattaforma carbonatica (localmente attribuiti al fig. 2 carta geologica semplificata del foglio 438 “bari”. simplified geologic map of the 438 sheet “bari”. 6 l. spalluto et al. tab. 1 stralcio delle note illustrative dei fogli 177 “bari” e 178 “mola di bari” in scala 1: 100 000 (azzaroli & valduga, 1967), relativo alla descrizione litostratigrafia delle unità del quaternario cartografate nell’area del foglio 438 “bari” in scala 1: 50 000. extract from the explanatory note of the 177 sheet “bari” and 178 sheet “mola di bari” (azzaroli & valduga, 1967 from the geologial maps of italy at the scale 1:100 000) showing the lithostratigraphic description of quaternary units mapped in the 438 sheet “bari” (at the scale 1: 50 000). 7 calcare di bari, azzaroli & valduga, 1967; spalluto et al., 2008; pieri et al., in prep.), che costituiscono il substrato dell'intera regione murgiana, poggiano in discordanza le unità della fossa bradanica, rappresentate da depositi del pleistocene inferiore (calcarenite di gravina ed argille subappennine) ed infine, in discordanza su tutti i depositi più antichi, si rinvengono i depositi marini e continentali terrazzati del pleistocene medio-superiore (supersintema delle murge suddiviso in 5 sintemi e supersintema delle lame delle murge suddiviso in 2 sintemi) (figg. 2; 3; 4). relativamente al rilevamento dei depositi dell’unità della fossa bradanica sono stati utilizzati i classici criteri litostratigrafici, mentre per i sovrastanti depositi marini e continentali terrazzati sono state applicate le indicazioni presenti nel quaderno 1 serie iii del servizio geologico d’italia (c.n.r.commissione per la cartografia geologica e geomorfologica, 1992) che privilegiano l’uso delle unità a limiti inconformi (ubsu). 3.1 unità della fossa bradanica 3.1.1 calcarenite di gravina (gra) la calcarenite di gravina affiora in lembi in tutta l’area del foglio 438 “bari” (fig. 2). lo spessore residuo affiorante è molto variabile fino ad un massimo di circa 20 metri nei pressi dell’abitato di carbonara di bari e del quartiere san paolo della città di bari (figg. 2; 4). questo dato è confermato anche dai numerosi sondaggi geognostici che sono stati effettuati da privati e da enti pubblici. come già specificato, a questa unità litostratigrafica vengono riferiti parte dei termini “tufi delle murge” e “tufo” introdotti formalmente negli anni '60 nelle carte geologiche ufficiali relative all'area compresa nel foglio 438 “bari” (tab. 1). la calcarenite di gravina poggia sui calcari cretacei del calcare di bari (fig. 3) e mostra caratteri di facies differenti da luogo a luogo. in aree limitate, nei pressi dell’abitato di palo del colle e nella periferia meridionale dell’abitato di bari, la parte inferiore della calcarenite di gravina è costituita a luoghi da sedimenti siltoso-sabbiosi spessi pochi metri; lo studio di tali sedimenti è stato effettuato sulle rare sezioni naturali ancora visibili e, durante fasi di scavo, su numerose sezioni artificiali che sono state poi velocemente ricoperte. questi depositi poggiano in discordanza sui calcari del cretacico tramite un contatto marcato da una superficie carsificata molto irregolare e colmano modeste depressioni morfo-strutturali allungate in senso ono-ese già esistenti nel substrato cretacico al momento dell'ingressione marina. come detto, la parte bassa di tali depositi, spessa pochi metri, è costituita da silt e sabbie limose rosse compatte, con più o meno frequenti livelli di ciottoli calcarei bianchi, mentre la parte alta è comunemente costituita da calcisiltiti poco cementate di colore giallo ocra o giallo paglierino che sfumano gradualmente verso l’alto alle calcareniti macrofossilifere (che caratterizzano ovunque la parte alta dell’unità). in accordo con iannone & pieri (1979) i silt argillosi rossastri basali sono stati interpretati come depositi alluvionali, mentre le calcisiltiti come depositi salmastro-lagunari che evolvono gradualmente verso l’alto ad ambienti marini più franchi. le facies più tipiche e diffuse della della calcarenite di gravina sono invece costituite da calcareniti lito-bioclastiche a tessitura grossolana che, laddove i sedimenti siltoso-sabbiosi sottostanti sono assenti, poggiano direttamente sul substrato cretacico. in quest'ultimo caso, il contatto è rappresentato da una discordanza angolare evidenziata da una superficie di abrasione sui calcari cretacei, frequentemente marcata da intensa bioerosione. tale contatto trasgressivo è ovunque ben evidente per il contrasto litologico fra i sottostanti calcari micritici del cretacico e i soprastanti depositi calcarenitici, dovuto ai diversi caratteri tessiturali e al diverso grado di cementazione. questa porzione più tipica della calcarenite di gravina è costituita da strati e banchi di calcareniti e calciruditi bioclastiche e di calcari organogeni ad alghe calcaree, scarsamente cementati e abbondantemente porosi, per uno spessonuovi dati stratigrafici e cartografici ... fig. 3 schema dei rapporti stratigrafici delle unità quaternarie del foglio 438 “bari”. calcari del cretacico: calcare di bari (cba). unità della fossa bradanica: calcarenite di gravina (gra); argille subappennine (asp). supersintema delle murge: sintema di rutigliano (mua); sintema di noicattaro (mun); sintema di carbonara (mub); sintema di san pasquale (muq); sintema di san girolamo (mui). supersintema delle lame delle murge: sintema di madonna delle grotte (mbl); sintema di coste s. giovanni (mbn). alluvioni attuali (b). sketch illustrating the stratigraphic relationships of quaternary units mapped in the 438 sheet “bari”. cretaceous unit: calcare di bari fm. (cba). bradanic trough units: calcarenite di gravina fm. (gra); argille subappennine fm. (asp). murge supersynthem: rutigliano synthem (mua); noicattaro synthem (mun); carbonara synthem (mub); san pasquale synthem (muq); san girolamo synthem (mui). lame delle murge supersynthem: madonna delle grotte synthem (mbl); coste s. giovanni synthem (mbn). present-day alluvial deposits (b). 8 re massimo complessivo di circa 20 metri. in particolare, tali depositi sono costituiti a partire dal basso da un banco di un paio di metri di biocalcareniti con abbondanti resti fossili interi o in frammenti, la cui base può essere marcata da sottili e discontinui livelli di ghiaie calcaree con abbondante matrice sabbiosa; segue per la restante parte un'alternanza di strati e banchi di biocalcareniti, biocalciruditi e calcari macroe microfossiliferi a lamellibranchi, gasteropodi, anellidi, echinidi, alghe rosse, foraminiferi bentonici e più raramente foraminiferi planctonici; a più altezze stratigrafiche, alle calcareniti si intercalano livelli calciruditici con alte concentrazioni di alghe rosse. dal punto di vista tessiturale si tratta in prevalenza di packstone, e/o di packstonegrainstone, costituiti quasi esclusivamente da bioclasti. nel complesso, la calcarenite di gravina mostra caratteri di facies riconducibili in prevalenza ad un sistema carbonatico dominato dalle onde, come suggerito regionalmente da tropeano & sabato (2000). per quanto riguarda l'età della calcarenite di gravina i residui di lavati di campioni provenienti da diversi affioramenti sono risultati in parte sterili; alcuni hanno fornito associazioni molto povere rappresentate prevalentemente da foraminiferi bentonici (ammonia spp., cibicides spp. ed elphidium spp.) oltre che da ostracodi, briozoi e frammenti di echinidi. regionalmente la formazione viene attribuita ad un intervallo compreso fra il pliocene medio ed il pleistocene inferiore (ciaranfi et al., 1988). da considerazioni regionali, lungo la costa adriatica l'età della formazione può essere attribuita al pleistocene inferiore. 3.1.2 argille subappennine (asp) alle argille subappennine viene riferita la porzione inferiore del termine argille di rutigliano introdotto negli anni '60 nelle carte geologiche ufficiali relative all'area ricompresa nel foglio 438 “bari” (tabb. 1; 2) ed in particolare esclusivamente nel foglio geologico in scala 1:100 000 178 “mola di bari” (azzaroli & valduga, l. spalluto et al. tab. 2 schema di correlazione litostratigrafica tra le unità affioranti nell’area di studio così come riportate nei fogli 177 “bari” e 178 “mola di bari” (scala 1: 100 000) e nel nuovo foglio 438 “bari” (scala 1: 50 000). lithostratigraphic correlation sketch among units cropping out in the studied area as reported in the 177 sheet “bari” and in the 178 sheet “mola di bari” (scale 1: 100 000) and in the new 438 sheet “bari” (scale 1: 50 000). 1967). le argille subappennine affiorano in un’area molto ristretta del settore sud-orientale del foglio 438 “bari” (figg. 2; 4), in corrispondenza di alcune cave aperte per la realizzazione di laterizi, ormai in disuso, in località pozzillo, nei pressi dell’abitato di rutigliano. altri residui lembi affiorano nei pressi dell’abitato di adelfia. lo spessore residuo affiorante è di circa 2 m, mentre lo spessore massimo ricavato dai sondaggi geognostici, realizzati da privati nei pressi dell’abitato di rutigliano, risulta essere di circa 8 m. il limite inferiore della formazione è stato osservato in corrispondenza di alcuni scavi per fondazioni nei pressi della periferia settentrionale dell’abitato di rutigliano e corrisponde ad un passaggio netto ma in continuità di sedimentazione sulla calcarenite di gravina (fig. 3). il limite superiore non è stato osservato in campagna ma dalle informazioni ricavate dai sondaggi geognostici si deduce che possa corrispondere ad un contatto netto con i depositi del sovrastante sintema di rutigliano (mua), che è il più antico dei sintemi del supersintema delle murge affiorante nell’area di studio. la brusca variazione delle facies che si osserva in corrispondenza di questo limite (da facies marine relativamente profonde a facies di laguna o di shoreface superiore) permette di ipotizzare che il limite tra queste due unità sia inconforme. in affioramento le argille subappennine sono costituite da argille siltose che si alternano ad argille marnose, silt e sabbie fini di colore grigio scuro. la bioturbazione caratterizza tali sedimenti ed è molto diffusa. all’interno di tali depositi, si rinvengono numerosi resti di bivalvi, briozoi e serpulidi sia in frammenti che interi e, dall’analisi dei lavati, è emersa la presenza di abbondanti foraminiferi planctonici e bentonici in buono stato di conservazione. un precedente studio mineralogico (dell’anna, 1969) ha evidenziato che la porzione inferiore di questa formazione è prevalentemente argillosa, ed è costituita da illite e montmorillonite ed è molto ricca in carbonato di calcio; la locale porzione superiore invece è rappresentata da argille a composizione caolinitica e da sabbie fini costituite prevalentemente da quarzo con ortoclasio, muscovite ed ossidi di ferro. la sedimentazione è attribuibile ad ambienti di piattaforma continentale, probabilmente di transizione tra la shoreface inferiore e l’offshore. in base a considerazioni di carattere regionale l’età delle argille subappennine può essere attribuita al pleistocene inferiore. 3.2 supersintema delle murge al supersintema delle murge vengono riferiti 5 ordini di depositi marini terrazzati riconosciuti nell'ambito dei nuovi rilevamenti condotti nell'area del foglio 438 "bari" (fig. 2). il supersintema è costituito da un insieme di depositi a composizione carbonatica e/o silicoclastica, riferibili ad ambienti costieri e accumulatisi a partire dal pleistocene medio e fino al pleistocene superiore in distinte fasi sedimentarie. il limite inferiore del supersintema è erosivo su tutte le unità più antiche (fig. 3). il limite superiore è anch’esso erosivo ed è localmente ricoperto da uno spessore esiguo, in genere di pochi decimetri, di suolo. nell’area del foglio 438 “bari” il supersintema delle murge è costituito da cinque sintemi (fig. 4) che verranno descritti a partire dal più alto in quota. trattandosi infatti di depositi marini terrazzati, nelle aree interne, più sollevate, si rinvengono i sintemi più antichi mentre in aree sempre più prossime alla linea di costa attuale si rinvengono progressivamente i sintemi più recenti. regionalmente, ciaranfi et alii (1988) attribuiscono tutti i depositi qui inclusi nel supersintema delle murge all’unità con il rango di formazione dei “depositi marini terrazzati”. 3.2.1 sintema di rutigliano (mua) il sintema di rutigliano rappresenta localmente il deposito più antico del supersintema delle murge e corrisponde alla porzione superiore della formazione indicata nella precedente edizione della carta geologica d’italia come argille di rutigliano (foglio 178 “mola di bari”; azzaroli & valduga, 1967) (tab. 2). il sintema di rutigliano affiora nella parte sudorientale del foglio 438 “bari” in corrispondenza dell’abitato di rutigliano (fig. 4), appena ad e dello spigolo sud-orientale del foglio. le migliori esposizioni sono state osservate nei pressi del cimitero di rutigliano ed in alcuni scavi di fondazione alla periferia dell’abitato. il limite inferiore di tale sintema è disconforme sia sulle argille subappennine che sulla calcarenite di gravina (fig. 3). lo spessore affiorante è al massimo di 2÷3 m, mentre lo spessore massimo stimato di tutto il sintema, ricavato dai sondaggi geognostici, è di circa 10 m. dal punto di vista litologico questo sintema è costituito da sabbie fini e silt marroncino-grigiastri bioturbati con rare concrezioni calcitiche nodulari che passano verso l’alto a sabbie argillose ed argille marroncino chiaro con plaghe sabbiose fini grigio-verdastre. noduli calcitici bianchi polverulenti caratterizzano la parte alta del sintema. il contenuto macrofossilifero è costituito da abbondanti frammenti di bivalvi, echinidi e serpulidi, mentre il contenuto microfossilifero osservato nei residui di lavati è costituito da foraminiferi bentonici e planctonici e da ostracodi non significativi per attribuzioni biostratigrafiche e cronostratigrafiche. i caratteri di facies ed il contenuto fossilifero indicano che il sintema di rutigliano si è prodotto in ambienti marini costieri. malgrado il contenuto fossilifero non sia risultato significativo per la datazione, sia la posizione stratigrafica che considerazioni di carattere regionale consentono di attribuire il sintema di rutigliano al pleistocene medio. 3.2.2 sintema di noicattaro (mun) il sintema di noicattaro è stato cartografato a nord dell’abitato omonimo (fig. 4) e rappresenta un lembo residuo spesso circa 5÷6 m che si trova a quote poste tra 85 e 90 m sul livello del mare. il limite inferiore del sintema di noicattaro è disconforme sulla calcarenite di gravina e sul calcare di bari (fig. 3). il sintema di noicattaro era stato incluso nella formazione dei “tufi delle murge” nella precedente edizione della carta geologica d’italia. a causa della penuria di affioramenti continui e ben esposti, la descrizione dei caratteri di facies di questo sintema deriva principalmente dallo studio stratigrafico e mineralogico effettuato da damiani (1996) in corrispondenza di uno scavo per fondazioni ora non più osservabile. il sintema di noicattaro è costituito nella parte bassa da un livello arenaceo spesso pochi centi9nuovi dati stratigrafici e cartografici ... 10 l. spalluto et al. fig. 4 carta geologica semplificata del settore orientale del foglio 438 “bari” (vedi il riquadro in fig. 2 per l’ubicazione). simplified geologic map of the eastern sector of the 438 sheet “bari” (see inset in fig. 2 for location). metri con ciottoli calcarei, che passa gradualmente verso l’alto a sabbie giallo-rossastre spesse circa 2 m con frequenti intercalazioni di croste calcaree biancastre. l’intervallo sabbioso si chiude con sabbia grigiogiallastra fine e poco compatta. sulle sabbie poggia con un contatto netto circa 1 m di calcari fossiliferi biancastri costituiti in prevalenza da gusci e modelli interni di lamellibranchi. sui calcari poggiano circa 20 cm di sabbie grigio-gialle bioturbate che passano verso l’alto a sabbie a composizione ibrida (silicoclastica e carbonatica) irregolarmente cementate ed in cui si riconoscono noduli calcitici bianchi. i caratteri di facies osservati permettono di riferire i depositi di tale sintema ad ambienti di transizione dal continentale al marino costiero. la parte superiore di questo sintema è delimitata da una superficie d’erosione marcata da sabbie rosse alluvionali. sia per la posizione stratigrafica che per considerazioni di carattere regionale il sintema di noicattaro può essere attribuito al pleistocene medio. 3.2.3 sintema di carbonara (mub) il sintema di carbonara affiora lungo alcuni fronti di cava e sezioni ferroviarie oltre che in corrispondenza del canale artificiale dell’abitato di carbonara di bari (fig. 4) e si eleva a circa 40÷45 m sul livello del mare, dal quale dista circa 5 km. il limite inferiore è disconforme sulla calcarenite di gravina (fig. 3). analogamente al precedente sintema, anche il sintema di carbonara era stato incluso nella formazione dei “tufi delle murge” nella precedente edizione della carta geologica d’italia (tab. 2). tale sintema è formato da una successione spessa al massimo 9÷10 m costituita alla base da ciottoli carbonatici derivanti dall’erosione della calcarenite di gravina immersi in una matrice sabbioso-siltosa molto fine di color giallo chiaro. gradualmente, verso l’alto i silt e le sabbie fini diventano più abbondanti e sono alternati a mudstone con piccoli gasteropodi e lamellibranchi a guscio sottile e rari foraminiferi bentonici (rotalidi). si riconoscono anche alcune superfici di emersione evidenziate dalla presenza di fratture riempite da croste calcaree. nella parte intermedia dell’unità diventano più frequenti i mudstone/wackestone biopeloidali costituiti da intraclasti micritici e da rari frammenti di lamellibranchi, gasteropodi, echinidi e foraminiferi bentonici. nella parte più alta dell’unità si distinguono strati sottili di sabbie calcaree fossilifere alternate a straterelli spessi alcuni centimetri di floatstone/rudstone bioclastici in matrice di packstone/grainstone costituiti in prevalenza da frammenti di gusci di lamellibranchi, brachiopodi, echinidi, gasteropodi, foraminiferi bentonici e planctonici (rari) e alghe calcaree. l’ambiente di sedimentazione del sintema di carbonara è variabile da una laguna ristretta soggetta a frequenti emersioni (parte inferiore), a facies protette di transizione ad ambienti marini costieri (parte intermedia) a facies chiaramente marine e relativamente più aperte di ambiente neritico (parte superiore). l’età del sintema di carbonara può essere riferita, in base alla posizione stratigrafica e a considerazioni di carattere regionale, al pleistocene medio-superiore (?). 3.2.4 sintema di san pasquale (muq) il sintema di san pasquale si estende per circa 5 km nella città di bari attraversandola interamente da ovest ad est (fig. 4), e costituisce un corpo che si eleva fino a 15 m sul livello del mare, dal quale dista circa 2 km. il limite inferiore di tale sintema è inconforme sia sul calcare di bari che sulla calcarenite di gravina (fig. 3). incluso nella formazione dei “tufi delle murge” nella precedente edizione della carta geologica d’italia (tab. 2), il sintema di san pasquale è stato attribuito più di recente all’unità informale del cordone littorale di bari (sensu pieri, 1988). il sintema di san pasquale è costituito da una successione spessa pochi metri, nell'ambito della quale è possibile distinguere tre unità litologiche di spessore metrico (pieri, 1975; 1988; moretti & tropeano, 1996) non cartografabili a causa del loro esiguo spessore e delle limitate aree di affioramento. dal basso verso l'alto, si distinguono un'unità siltosa, un'unità sabbiosa, un'unità ghiaiosa. l'unità siltosa, spessa da pochi decimetri a circa 2 m, è costituita da silt laminati ricchi di ostracodi e di resti di characee, ai quali si intercalano straterelli di calcari nodulari a tessitura wackestone e fossiliferi (ostracodi, oogoni di characea, piccoli gasteropodi). verso l'alto l'unità siltosa passa rapidamente all'unità sabbiosa, spessa 1,5÷2 m; questa unità è rappresentata da sabbie ben classate, con granuli arrotondati e prive di matrice. sia l'unità siltosa che l'unità sabbiosa sono caratterizzate per quasi tutto il loro spessore dalla presenza di strutture sedimentarie deformative (tipo load-casts e ball and pillows) che presentano dimensioni variabili da 10 a 60 cm, con forme irregolari, spesso subsferiche, la cui origine è stata riferita ad un sisma che ha interessato l'area durante la sedimentazione del sintema stesso (moretti & tropeano, 1996; moretti et al., 2002). infine, sul lato verso mare, sui depositi sopra descritti poggia, in contatto erosivo, l’unità ghiaiosa spessa circa un metro. quest’ultima unità è ben stratificata ed è costituita da ciottoli discoidali ben arrotondati e ben classati immersi in una matrice sabbiosa grossolana. dal punto di vista ambientale il deposito siltoso è stato attribuito ad un ambiente lagunare, quello sabbioso ad un ambiente eolico di retrospiaggia e quello ghiaioso ad un ambiente di avanspiaggia (moretti & tropeano, 1996). l’età del sintema di san pasquale viene riferita, sia in base alla posizione stratigrafica che a considerazioni di carattere regionale, al pleistocene superiore (pieri, 1988; moretti & tropeano, 1996). 3.2.5 sintema di san girolamo (mui) con andamento parallelo alla costa, sia a nordovest che a sud-est della città di bari (fig. 4) si rinvengono lembi residui di depositi calcarenitici, irregolarmente cementati, che originariamente costituivano dei piccoli rilievi allungati secondo la linea di costa (virgilio, 1900; zezza, 1971; pieri, 1975). questo sintema corrisponde all’unità cartografata come “depositi costieri” nel f° 177 “bari” (scala 1:100 000) (tab. 2) successivamente attribuita all’unità informale in facies costiera delle “dune di san girolamo” (sensu pieri, 1988). l’ubicazione di tale sintema nell'ambito del perimetro cittadino impedisce nelle condizioni attuali il riconoscimento dei principali caratteri (morfologia, spessore, contatti con le unità sottostanti ecc.); infatti, le aree di affioramento sono state completamente urbanizzate, 11nuovi dati stratigrafici e cartografici ... e dell'originario deposito rimangono solo pochi testimoni sulla base dei quali è stato possibile delimitare le aree di affioramento ed i caratteri di facies. a tal fine sono stati molto utili anche i dati di profondità ottenuti dai numerosi sondaggi eseguiti a scopo geognostico da enti pubblici e da privati, da cui si ricava che i depositi appartenenti a tale sintema poggiano con contatto inconforme e discordante sia sul substrato cretacico che sulla calcarenite di gravina (fig. 3). tale sintema è formato da calcareniti che presentano sottile stratificazione obliqua a vario angolo ed in cui si riconoscono fossili continentali (gasteropodi del genere helix); in genere sono ben cementate, molto porose, ben classate e fittamente laminate, e vengono attribuite ad ambienti eolici di retrospiaggia. in assenza di un contenuto fossilifero significativo ai fini bioe cronostratigrafici, il sintema di san girolamo è stato attribuito, per la posizione stratigrafica ed in base a considerazioni di carattere regionale, al pleistocene superiore. 3.3 supersintema delle lame delle murge il supersintema delle lame delle murge comprende tutti i depositi alluvionali terrazzati posti qualche metro al di sopra dell’attuale alveo dei principali corsi d’acqua presenti nell’area (fig. 2). tali corsi d’acqua formano il reticolo idrografico delle murge basse e sono attualmente incassati nel substrato. i depositi del supersintema delle lame delle murge, poggianti con limite inconforme sul calcare di bari, presentano caratteristiche litologiche e tessiturali molto simili e sono stati inseriti in due differenti sintemi: il sintema di madonna delle grotte ed i l sintema di costa s. giovanni. il supersintema delle lame delle murge corrisponde alle alluvioni terrazzate incluse nei “depositi alluvionali” dagli autori della precedente edizione della carta geologica d’italia (tab. 2). 3.3.1 sintema di madonna delle grotte (mbl) tale sintema, poggiante con limite inconforme sul calcare di bari (figg. 3, 4), è costituito da depositi alluvionali cementati che affiorano in lembi terrazzati lungo i maggiori solchi erosivi (lama balice e lamasinata). si tratta di conglomerati ben cementati con spessori variabili da pochi centimetri a circa 2÷3 m costituiti da ciottoli carbonatici in matrice residuale siltoso-sabbiosa rossastra. si trovano a quote comprese tra i 4 e gli 8 m sopra l’alveo dei principali corsi d’acqua, pertanto, si sono deposti prima dell’incassamento delle lame in strette valli all’interno dei calcari mesozoici. l’età è riferibile, per la posizione stratigrafica e per considerazioni di carattere regionale, al pleistocene medio e superiore (?). 3.3.2 sintema di costa s. giovanni (mbn) tale sintema è costituito da depositi alluvionali conservati in piccoli lembi terrazzati lungo il tratto più a monte dei maggiori solchi erosivi (lama balice, lamasinata e picone) (fig. 4). si tratta di ghiaie spesse 2÷3 m, solo a luoghi cementate, con ciottoli calcarei subarrotondati e matrice residuale siltoso-sabbiosa. si rinvengono a quote comprese tra 1 e 2 m sopra l’alveo dei principali corsi d’acqua. il limite inferiore è inconforme sul calcare di bari (fig. 3). l’età è riferibile, per la posizione stratigrafica e per considerazioni di carattere regionale, al pleistocene superiore. 3.4 deposito alluvionale recente ed attuale (b) si tratta di sedimenti di origine alluvionale che occupano il fondo di numerosi solchi erosivi, e ampie aree a ridosso del sintema di san pasquale e del sintema di san girolamo (fig. 2). sono costituiti da ghiaie formate da clasti calcarei subarrotondati in matrice siltoso-terrosa rossastra, con rare intercalazioni di silt argillosi. il loro spessore varia notevolmente da luogo a luogo, raggiungendo nelle zone più prossime al mare i 10 metri. l’età è riferibile al pleistocene superiore-olocene. 4. confronto fra vecchio e nuovo quadro stratigrafico delle unità del quaternario affioranti nel foglio 438 "bari". viste le notevoli differenze riscontrate dal confronto fra vecchio (fogli 177 "bari" e 178 "mola di bari" della carta geologica d'italia alla scala 1:100 000) e nuovo quadro stratigrafico delle unità del quaternario affioranti nel foglio 438 "bari" (vedi tab. 2), si ritiene opportuno ribadire i motivi che hanno portato all’adozione di un diverso criterio di classificazione stratigrafica presente in quest'ultimo, che riafferma una scelta già operata in precedenza a livello regionale da altri autori (ciaranfi et al., 1988). come esposto, parte dei depositi definiti come tufi delle murge nel foglio 177 "bari" della carta geologica d'italia in scala 1:100 000 sono stati ora attribuiti alla calcarenite di gravina, così come suggerito da iannone & pieri (1979) (tab. 2). occorre sottolineare che non si è trattato né di una scelta semantica né di una scelta dettata da priorità di istituzione formazionale. all'epoca dei rilevamenti compiuti negli anni '60 per la realizzazione della carta geologica d'italia alla scala 1:100 000 (e tutt'ora in ambito commerciale o applicativo) tutti i litotipi calcarenitici, prevalentemente organogeni e facili da tagliare in conci da costruzione, venivano informalmente definiti tufi o tufi calcarei. era questa anche l'accezione utilizzata da d'erasmo (1934) per identificare tutti i depositi discordanti sui calcari cretacei delle murge, pur essendo l'autore consapevole della esistenza di più facies poste in posizione stratigrafica differente: alcune depositatesi in un contesto di generalizzata ingressione marina, altre invece durante diverse fasi di ritiro del mare. è solo a quest'ultimo contesto che azzaroli & valduga (1967) attribuiscono tutti i depositi della formazione dei tufi delle murge, con un significato opposto a quello dato dallo stesso azzaroli (1968) alla calcarenite di gravina così come definita sul lato bradanico delle murge. utilizzare quindi quest'ultimo termine formazionale per identificare alcuni dei depositi in precedenza attribuiti ai tufi delle murge significa posizionare diversamente tali depositi in un contesto litoe cronostratigrafico regionale ed attribuire loro un significato geodinamico differente. tuttavia, durante i lavori di rilevamento del nuovo foglio 438 "bari" sono stati distinti depositi più recenti della calcarenite di gravina, formatisi in un contesto di generale regressione che risponde 12 l. spalluto et al. bene alla definizione formazionale originale data da azzaroli & valduga (1967) all’intera successione dei tufi delle murge; per questi si è preferito utilizzare il termine supersintema delle murge che da una parte permette di distinguere i differenti episodi di terrazzamento deposizionale marino riconosciuti nell'area (sintemi) e dall'altra evita di riportare confusione nella terminologia formale utilizzata, visto che anche in questo caso non tutti i depositi cartografati come tufi delle murge possono essere ricondotti al supersintema delle murge (tab. 2). 5. considerazioni conclusive i lavori di rilevamento del foglio 438 “bari”, che è il primo foglio del progetto carg per la regione puglia realizzato nell’area delle murge, consentono di aggiornare significativamente le conoscenze dell’area, fornendo anche una stratigrafia originale del quaternario. i criteri stratigrafici utilizzati sono stati sia quelli classici litostratigrafici, relativamente alle unità del ciclo della fossa bradanica (calcarenite di gravina ed argille subappennine), che quelli basati sull’uso delle unità a limiti inconformi (ubsu), per le più recenti unità marine e continentali terrazzate. la nuova stratigrafia, più ricca ed articolata di quella presente nella precedente edizione della carta geologica d’italia (scala 1: 100 000), fornisce una chiave di lettura più completa e più coerente dell’evoluzione sedimentaria dell’area di studio e, per i criteri stratigrafici utilizzati e le scelte cartografiche operate, si ritiene possa essere esportata con successo anche nelle aree limitrofe. infatti, i dati stratigrafici esposti in questo lavoro permettono di tracciare i punti principali dell’evoluzione sedimentaria quaternaria del settore delle murge basse compreso nel foglio 438 "bari", che ben si inquadrano nel contesto delle conoscenze geologico-regionali sintetizzate da ricchetti et al. (1988). i depositi quaternari più antichi (calcarenite di gravina e argille subappennine) affioranti nell’area di studio fanno parte del ciclo bradanico e hanno registrato dal punto di vista stratigrafico la fase di subsidenza regionale che ha determinato durante il pliocene superiore ed il pleistocene inferiore il progressivo annegamento di vasti settori delle murge. il ritorno del mare in un'area esposta fin dal cretacico superiore ha portato alla formazione di coperture sedimentarie, che, in corrispondenza di depressioni morfostrutturali già presenti all'atto dell'ingressione, hanno fossilizzato depositi continentali o palustri, conservatisi localmente alla base della calcarenite di gravina. alla fase di trasgressione, registrata nell’area di studio dalla sedimentazione della calcarenite di gravina (pleistocene inferiore), segue la fase di massimo approfondimento del sistema, marcata dal passaggio, in continuità di sedimentazione, dalle facies calcarenitiche alle facies pelitiche delle argille subappennine. nell'ambito del foglio 438 "bari" queste ultime si conservano esclusivamente nei pressi dell'abitato di rutigliano. alla fase ingressiva è seguita una fase regressiva, da mettere in relazione con un fenomeno di sollevamento regionale ben noto in tutta l'area pugliese. l'interferenza fra sollevamento regionale, iniziato nel pleistocene medio, ed eustatismo ha prodotto una successione di eventi erosivi e sedimentari che hanno portato alla formazione dei depositi marini terrazzati del supersintema delle murge (pleistocene medio e superiore). ad ognuno dei cinque ordini di terrazzi deposizionali riconosciuti nell'area è stato attribuito quindi il rango di sintema. la distribuzione altimetrica dei singoli sintemi appartenenti al supersintema delle murge testimonia le tappe del sollevamento della regione, evidenziate anche dall'approfondimento intermittente dei principali corsi d’acqua che hanno registrato fasi alterne di incisione e di alluvionamento con conseguente disposizione in terrazzi dei depositi alluvionali, definiti nell'insieme come supersintema delle lame delle murge (pleistocene medio e superiore). il complesso dei depositi marini e continentali del quaternario attribuiti in questa nota sia al supersintema delle murge che al supersintema delle lame delle murge è relativo alla parte più recente del processo regressivo verificatosi sul versante adriatico delle murge. allorché le ricerche si estenderanno alle porzioni più interne delle murge, verosimilmente verranno individuati altri sintemi, più antichi di quelli riportati in questa nota, riferibili anch’essi al supersintema delle murge ed al supersintema delle lame delle murge. lavori citati azzaroli a. (1968) calcarenite di gravina. studi illustrativi della carta geologica d’italia formazioni geologiche. servizio geologico d’italia, i, 183185. azzaroli a., radina b., ricchetti g. & valduga a. (1968) note illustrative della carta geologica d’italia. foglio 189 “altamura”. serv. geol. d’it., pagg. 22 azzaroli a. & valduga a. (1967) note illustrative della carta geologica d’italia. foglio 177 “bari” e foglio 178 “mola di bari”. serv. geol. d’it, pagg. 26. ciaranfi n., pieri p. & ricchetti g. (1988) note alla carta geologica delle murge e del salento (puglia centromeridionale). mem. soc. geol. it., 41, 449460. c.n.r. commissione per la cartografia geologica e geomorfologia (1992) carta geologica d’italia 1:50.000 guida al rilevamento. quaderni del servizio geologico nazionale , serie iii, 1: 203 pp. damiani m. g. (1996) caratteri stratigrafici e mineralogici del versante orientale delle murge (area di bari e noicattaro). tesi di laurea inedita in scienze geologiche, 151 pp. università di bari dell’anna (1969) indagini mineralogiche e chimiche sulle “argille di rutigliano”. period. miner., 38, 515-577. d’erasmo g. (1934) il mare pliocenico della puglia. memorie geologiche e geografiche di giotto dainelli, 4, 307-396. iannone a. & pieri p. (1979) considerazioni critiche sui tufi calcarei delle murge. nuovi dati litostratigrafici e paleoambientali. geogr. fis. e din. quat., 2, 173-186. moretti m. & tropeano m. (1996) strutture sedimentarie deformative nei depositi tirreniani di bari. mem. soc. geol. it, 51, 485-500. moretti m., pieri p. & tropeano m. (2002) late pleistocene soft-sediment deformation structures inter13nuovi dati stratigrafici e cartografici ... preted as seismites in paralic deposits in the city of bari (apulian foreland, southern italy). in: etthenson f.r., rast n., brett c. e. eds., ancient seismites. geol. soc. am., special paper 359, 75-85. pieri p. (1975) geologia della città di bari. mem. soc. geol. it., 14, 379-407. pieri p. (1980) principali caratteri geologici e morfologici delle murge. murgia sotterranea, 2/ 2, 13-19. pieri p. (1988) evoluzione geologica e geomorfologica dell’area di bari. in: archeologia di una città. bari dalle origini al x secolo. edipuglia, 7-20. pieri p. & spalluto l., con contributi di: andriani g.f., caffau m., labriola m., maggiore m., marino m., sabato l., tropeano m. & walsh n. (in prep.) note illustrative della carta geologica d’italia alla scala 1:50.000 foglio 438 bari. apat-ispra. ricchetti g., ciaranfi n., luperto sinni e., mongelli f. & pieri p. (1988) geodinamica ed evoluzione sedimentaria e tettonica dell'avampaese apulo. mem. soc. geol. it., 41, 57-82. selli r. (1962) le quaternaire marin du versant adriatique-ionien de la peninsule italienne. quaternaria, 6, 391-413. spalluto l., caffau m. & de giorgio g. (2008) the upper albina-lower cenomanian inner shelf carbonate succession of the calcare di bari fm. from the murge area (apulia, southern italy): lithostratigraphy, biostratigraphy and facies analysis. rend. soc. geol. it online, 2, 175-180. spalluto l., pieri p. & ricchetti g. (2005) le facies carbonatiche di piattaforma interna del promontorio del gargano: implicazioni paleoambientali e correlazioni con la coeva successione delle murge. (italia meridionale, puglia). boll. soc. geol. it, 124, 675-690. tropeano m. & sabato l. (2000) response of pliopleistocene mixed bioclastic-lithoclastic temperate-water carbonate systems to forced regression: the calcarenite di gravina formation, puglia, se italy. in: hunt d., and gawthorpe r.l. (eds.) sedimentary responce to forced regression. geological society, spec. publ., 172, 217-243. virgilio (1900) geomorfogenia della provincia di bari. in: “la terra di bari sotto l’aspetto storico, eonomico e naturalistico”, 96. zezza f. (1971) significato geologico e caratteristiche sedimentologiche delle dune e dei depositi di spiaggia fossili fra bari e monopoli. geol. appl. e idrogeol., 6, 1-15. 14 ms. ricevuto il 19 febbraio 2009 testo definitivo ricevuto il 21 ottobre 2009 ms. received: february 19, 2009 final text received: october 21, 2009 l. spalluto et al. available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 31 (2), 2018, 221 234 geological and geomorphological controls on flood phenomena in the putignano town, southern italy paolo giannandrea 1 , salvatore laurita 1 , francesca pugliese 2 1 dipartimento di scienze, università degli studi della basilicata, potenza, italy 2 via roma, 13, 70017 putignano (ba), italy corresponding author: p. giannandrea <paolo.giannandrea@unibas.it> abstract: the geological/geomorphological map of putignano town (bari, southern italy) contains useful evidence of landforms and sedimentary successions in both urbanized and industrial areas, contributing also to a better understanding of floodings during high-magnitude pluviometric events in the area. the analyzed flooded areas correspond to surfaces karst landforms with different shapes and sizes. our detailed geological/geomorphological study shows that most of the industrial area of putignano was built on cretaceous calcareous units in a depressed area, which corresponds to an extensive endorheic basin (locally called "il basso"). part of the local urban expansion, built from 1950 to present day, occupies the most depressed areas of numerous karst valleys that, despite this urbanization, still preserve their hydraulic function. usually these geological and geomorphological features are not yet completely identified and, unfortunately, not taken into consideration in the planning stages of the urban expansion and industrial settlement. keywords: putignano town, southern italy, apulian foreland, quaternary, flood, karst 1. introduction putignano is a small town in the south-eastern murge, an area frequently exposed to alluvial events that occur despite the numerous mitigation actions taken to reduce or eliminate long-term risk to people and infrastructure. environmental degradation and irreversible landscape damages caused by the negative impact of human activities here as well as in other karst territories were described and discussed in several publications (e.g. white, 1988; gams et al., 1993; williams, 1993; nicod et al., 1997; akdim & amyay, 1999; burri et al., 1999; urich, 2002; parise & pascali 2003; bonacci 2004; calo` & parise 2006; sauro, 2006; parise & gunn 2007; andriani & walsh, 2009). they cover different environmental issues, which are causing general concern about the need to: i) prevent/control flood events and ii) design and/or redevelop the urban expansion in the way that floods rather than damaging events can be seen as resources for the territory (muscari, 2016). this contribution provides new evidence on landforms and correlative quaternary deposits mapped at a detailed scale (1:10.000 and 1:500) for the entire territory of putignano. the main objective of our study is to recognize the geological/geomorphological features that predispose the putignano territory to flooding phenomena and therefore to provide basic information for future risk mitigation strategies and adequate use planning. within this context, we have also evaluated the different phases of building expansion and the presence of anthropogenic deposits. 2. geological and geomorphological setting of the murge relief the carbonate rocks of the murge hills, with the gargano and the serre salentine, constitute a portion of the apulian platform system. the apulian platform is placed between two orogenic chains and represents the outcropping part of a highly asymmetric structure: the pliocene to pleistocene foreland, which is characterized by opposite dipping directions, towards southwest beneath the southern apennines and towards northeast beneath the dinaric-albano-ellenide chain (ricchetti et al., 1988; funiciello et al., 1991; argnani et al., 1993; carminati & doglioni, 2004; carminati et al., 2005) (fig. 1a-c). the apulian carbonate platform is mainly composed by jurassic to cretaceous dolomitic and calcareous units, approximately 5 km thick, downward followed by hydritic and dolomitic upper triassic succession, approximately 1 km thick, and triassic terrigenous deposits (both alluvial and deltaic) approximately 1 km thick (ricchetti et al., 1988). in particular, the murge area is composed of a cretaceous succession with general dipping towards the ssw, affected by gentle folds and faults (fig. 1b). the folds, arranged with axis in nwse, wnw-ese and ene-wsw directions (martinis, 1961; valduga, 1965; pieri, 1980; ciaranfi et al., 1988; ricchetti, 1980; ricchetti et al., 1988), have been considered intraplate deformations related to the alpine compression events, or as a deformation linked to the https://doi.org/10.26382/amq.2018.17 222 giannandrea p. et al. neogene compressive tectonics, responsible also for the south-apennine building (pieri, 1980; festa, 1999). more in particular, festa (1999) considered that the folds might be related to the second interpretation. this setting is observed in the north-western sector of the murge where the foreland is close to the thrust belt (fig. 1a). the main regional faults, mainly n-s, nw-se, wnw-ese, ne-sw and e-w oriented, divide the murge into different structural blocks separating the high murge hills from the adjacent morpho-structural depressions (martinis, 1961; ricchetti, 1980; iannone & pieri, 1982; gambini & tozzi, 1996; pieri et al., 1997b). in the apennines and apulian foreland system, this structure is connected to extensional and transtensional deformation regimes associated with pliocene to middle pleistocene tectonics (pieri et al., 1997b, and references therein; schiattarella et al., 2005). the nw-se normal faults of the northern murge and the e-w transtensive faults of the southern murge (canale di pirro area; fig. 1b) determined, in the upper cretaceous, both the regional south -west dipping of the cretaceous succession and the calcareous depositions (festa, 2003). the carbonate succession outcropping in the murge relief is subdivided in the "calcare di bari" (valanginian later cenomanian; 2 km thick), "calcare di altamura" (upper turonian santonian; 1 km thick), and “calcare di caranna” (early campanian -later maastrichtian; 25 m thick) formations (valduga, 1965; pieri, 1980; ciaranfi et al., 1988, luperto sinni, 1996 and references therein; luperto sinni & fig. 1 a) geological sketch map of the southern peri-adriatic region. the apulian platform represents the foreland sector shared by both the southern apennines and the albano-hellenides fold and thrust belts. b) schematic structural-geological map of the murgia area, showing the putignano territory (modified after festa, 2003). c) regional cross-section, modified after carminati & doglioni (2004). 223 geological and geomorphological controls on flood phenomena in the putignano town, s italy fig. 2 schematic geological sketch map, with geomorphology elements of the putignano territory. 224 fig. 3 a) litho-stratigraphic features of the carbonate bedrock. b) pleistocene marine silty clayey sediments overlain by laminated colluvial reddish sandy sediments c) cataclastic breccia showing in d) kinematic indicators. e) volcanic sediments represented by fine-grained ash overlain by colluvial reddish sand. f) lateritic deposits in karst cavities formed in the mesozoic calcareous beds. g) lateritic deposits constituted of fine-laminated reddish clay. giannandrea p. et al. reina, 1996). these units are separated by unconformities (ciaranfi et al., 1988), locally highlighted by the presence of reddish residual clay deposits (bauxite of spinazzola; crescenti & vighi, 1964; maggiore et al., 1978; iannone & laviano, 1980; luperto sinni & reina, 1996). the cretaceous limestone formations represent the bedrock of the pliocene-quaternary transgressive succession made up of pliocene-pleistocene shallowmarine coarse-grained carbonates (calcarenite di gravina formation) overlain by lower pleistocene hemipelagic clay (argille subappennine formation) (iannone & pieri 1979; ricchetti et al., 1988; giannandrea et al., 2014). middle-upper pleistocene silty–clays deposits and coarse calcarenite (depositi marini terrazzati) disconformably overlay the mesozoic and pliocenepleistocene successions (ricchetti et al., 1988). finally, upper pleistocene holocene reddish-brown colluvial deposits (‘‘terre rosse’’) are found as a mantle over the valley floors. the morphology of the murge plateau, in close relationship with its lithological composition, geological structure, and climatic variations, is attributable to karstic processes which start to develop from the cretaceous (anelli, 1962). in particular, the murge is a nw-se orientated rectangular plateau bounded by steep slopes (campobasso & olivieri, 1967; di geronimo, 1970) with small endoreic basins which rise some reliefs, predominantly conical in shape, that testify a miocene relit karstic landscape (sauro, 1991a, b). the karst landforms recognizable on the murge include shallow holes, dolines, dry (blind) valleys, and poljes (parise, 2011). the most remarkable karst features are, in the northwestern murgia, some sinkholes (sensu gutierrez et al., 2014) with circular shape and vertical slopes (high: some tens of meters) called “pulo, gurgo, etc.” (colamonico, 1917a, b;1919a, b; 1919-20), and in the southeast sector, along an e-w orientated transtensive faults system (festa, 2003), an alignment of some endoreic karst basins called “canale di pirro” (fig. 1b; pieri et al., 1997a) and interpreted as polje (parise, 2006; parise & benedetto, 2018). also, during the long period of exposure of the murge, different phases of karstification produced the genesis of several caves with vertical and horizontal development, ranging in size from a few square meters wide to large and complex systems, with overall length on the order of some kilometers. the largest and longest cave, of considerable tourist interest, is the cave of castellana grotte (anelli, 1954). it consists of a complex endokarst conduits system that develops for a total length of 3348 m, reaches the maximum depth of 122 m from the surface, and is reachable through a sinkhole (locally called “grave”) 60 m deep (reina & parise, 2004). the latter was formed by gravitational collapses that proceeded upward and were controlled by the main fracturing system in the rock mass (lollino et al, 2004; parise & trisciuzzi, 2007; parise, 2008). the karts valley consists of dry blind valleys and canyons, known respectively as "lame” and “gravine" (parise, 2008). the “lame” can develop into three different landforms depending on the position and dipping of the substrate. in particular, they are (boenzi, 1988, and references therein): i) short and deep, with a transverse v profile, along the bradano slope; ii) flatbottomed and with a sinuous trend, in the high and middle murgia area and iii) flat-bottomed with sub-vertical sides along the adriatic coast. the “gravine”, localized on the ionian side of the murge, from taranto to matera towns, are canyons with sub-vertical slopes up to 100 m high (azzaroli et al., 1968) developed from the top of the plateau (400 m a.s.l.) to the coastal plain (50-100 m a.s.l.). these valleys, generally dry for long periods of time, host water channels only during and immediately after abundant rains (baldassarre & francescangeli, 1987; andriani & walsh, 2009). often the alluvial valleys are included in contexts of endorheic basins, where the karst valleys pour out into flat-floored depressions, with or without a swallow-hole (pace, 1995; parise, 2006 and references therein), where temporary small lake can be formed in case of intense periods of precipitation (orofino, 1990; parise, 2009 and references therein; delle rose, 2007; lopez et al., 2009). the floodwaters, through a complex system of fractures and karst cavities, percolate into the subsurface up to a deep water table. a detectable water table interests the entire murgia plateau with a convex piezometric surface sloping toward the bradano river, to the southwest, and the adriatic sea to the northeast (maggiore & pagliarulo, 2004; tulipano et al., 2008). 3. geological and geomorphological features of the putignano area our field survey allowed the production of a 1: 10.000 scale geological map (fig. 2 for a sketch) and revealed that the geological structure of the putignano municipal territory is entirely composed by a mesozoic carbonate succession (i.e. the calcare di altamura formation, fig. 2) which consists of weakly undulating layers dipping toward the southwest (fig. 3a). the coniacian to santonian sedimentary succession consists of 30-70 cm thick layers (fig. 3a) of biocalcilutites alternated with thin layers of biocalcarenites organized in different facies and grouped into sequences of 1-3 m thick layers (luperto sinni et al., 1988). the complete sequence is made up of four lithofacies: a) rudist rich beds; b) micritic limestone with isolated fragments of rudists and foraminifera; c) stromatolytic or criptoalgal laminated limestones; d) limestone with drying fractures. metric layers of bioclastic concentrations of rudists, laterally extended for several hundred meters, are visible at different stratigraphic levels of the succession. in the monticello and frascina localities, in the northern side of the industrial area of putignano, and at the base of the left side of the san cataldo valley (fig. 2), the calcareous succession is characterized by a cataclastic breccia (fig. 3c) along a n105°-striking vertical tectonic structure. the kinematic indicators for this structure show a right-lateral movement (fig. 3d). the beginning of tectonic activity is traced back to the same phase of sedimentation of the calcare di altamura formation (upper cretaceous) (festa, 2003). the pleistocene tectonic evolution led to the formation of extensive depressed areas submerged by the sea. the evidence of this event is clearly visible in the frassineto locality (fig. 2), where pleistocene marine silty-clay sediments unconformably 225 geological and geomorphological controls on flood phenomena in the putignano town, s italy overlay the calcareous bedrock (fig. 3b) (servizio geologico d’italia f. 190 monopoli, 1988). isolated calcic nodules occur in the upper part of the silty-clayey sediments (fig. 3b), and are associated with the erosive surface presents to the top of the unit (fig. 3b). they suggest a long period of exposure with development of a paleosol (103 to 104 yrs; mack & madoff, 2005) followed by an erosional phase which excised its upper portion (layers a and b of the paleosol). the age of this unit is referred to the lower pleistocene-middle pleistocene transition, during the maximum transgression of the sea level in the bradano foredeep basin (corrado et al., 2017, and references therein). upper pleistoceneholocene colluvial deposits are detectable, as a mantle over the karst valleys floor, above the cretaceous and pleistocene marine sediments. they consist of reddishbrown silty clay (2-10 m tick), with interbedded volcanic ash levels and scattered calcareous stones. the volcanic deposits (fig. 3e) generally consist of a basal volcanic ash layer (10 cm thick) overlain by epiclastic sediment (80-110 cm thick). the basal bed consists of finegrained structureless ash (fall deposit) and the upper layer consists of grayish fine-grained, fine-laminated ash mixed with reddish-brown, finelaminated silty clay (colluvial deposit). the origin of volcanic ash can be related to the eruptions of the quaternary campania volcanoes, because the putignano territory is localized in the dispersion area of the tephra generated by the activity of these volcanoes (sulpizio et al., 2003). finally, in the southern sector of the “il basso” (fig. 2), several caves with oblique (fig. 3f) and vertical development (2-10 m large) and filled by reddish-brown fine laminated clay (i.e. lateritic sediments; fig. 3g) have been detected. in this sector the calcareous bedrock shows moderate to high fracturing with two fracture sets: n7080°, associated to closed, 50-cm spaced, sub-vertical joints; n 130°, dipping of about 75°, with 40-cm spaced joints, 1-2 mm open. the rock is altered by deformation to a limestone breccia and a matrix-supported breccia, with clasts of a maximum size of 36.5 cm and matrix composed of silty-sandy reddish clay in the portion with intense fracturing. finally, in the putignano town some karst valleys were filled by anthropic deposits made up of a clast-supported calcareous breccia (fig. 4a). the geomorphological features recognized in the putignano territory permit to describe three main morpho -structural sectors, two of which are hilly and one subflat, distributed in three e-w-oriented elongated areas (fig. 5). the sub-flat area, with altitude between 342 and 295 m a.s.l., is centrally located (sector 2, fig. 5), and gently sloping northwards, between the “il basso” and frassineto localities. the northern side portion of the putignano territory (sector 1, fig. 5) shows numerous dolines (size ranging from 50-100 m2 to 500 m2) and small endorheic basins, with colluvial deposits (few meters thick) over the valley floors (fig. 2). elevations vary from about 377 m a.s.l. in the southeastern sector, to 321 m a.s.l. in the northwestern sector. finally, karst valleys prevail in the southern portion of the putignano territory (sector 3; fig. 5), with well-developed hydrographic networks: many channels of the first, second, and third order, three valleys of the fourth order and a valley (san cataldo valley) of the fifth order are recognized. the valleys of the fourth and fifth order converge into the sector 2 (fig. 5). the highest altitudes in the areas 3 vary from a maximum of 440-460 m a.s.l., in the eastern sector, to a minimum of 380 m a.s.l., in the western sector. the putignano urban area is located on the southern portion of the sector 1 (fig. 5), along the right side of the san cataldo valley. in this sector the slope is cut by some channels of the first order filled with 226 fig. 4 a) view of a valley filled by anthropic coarse grained breccia deposits. b) straight river erosion furrow, showing channel incision. giannandrea p. et al. precipitation, causing the occurrence of the floods in the karstic valleys (figs. 5 and 7). historical information on the floods occurred in the putignano territory can be colluvial deposits covering old channel incisions (fig. 4b). such morphologies record the events during which the alluvial valleys were cut by large quantities of water with high solid transport. the sector 2 includes three wide valleys (frassineto, casa padula, and “il basso”; figs. 2 and 5) with a flatbottom one kilometer square large (fig. 2): the casa padule and “il basso” valleys were filled by colluvial deposits, whereas the frassineto valley by marine sediments (servizio geologico d’italia f. 190 monopoli, 1988; fig. 2). the morphological limits on the southern and northern sides are characterized by steep slopes (>50%) along e-w directed faults, interpreted by festa (2003) as oblique transfer faults. the three valleys are separated from each other by gentle hills that rise up to eight-meters, between “il basso” and casa padule, and just two meters, between casa padule and frassineto (fig. 6). geomorphological analyses (figs. 2 and 5) revealed that casa padule and “il basso” are depressed areas of extensive endorheic basins, whereas the frassineto area is crossed by tributaries karst valleys of a watercourse that, near the bari city, spreads into the adriatic sea (mossa, 2007). moreover, the areas of the casa padule and frassineto are included in a slope change line traceable from 342 to 307m a.s.l. (fig. 2) that, given the presence of marine fine sediments, can be interpreted as a point of maximum ingression of the sea level during the pleistocene marine transgression. subsurface karst forms (22 caves) have been documented in the putignano territory (catasto delle grotte e delle cavità artificiali della puglia, 2013), among which the “grotta del trullo” (pu_1) is a tourist cave and the “s. michele in monte laureto” (pu_4) and “s. maria delle grazie” (pu_5) caves are places of worship. 4. floods in the putignano territory the karst terrains of putignano are characterized by a very limited or absent surface hydrography. normally the water tends to quickly infiltrate in the underground through a complex fractures network and karst conduits in the rock mass. however, such network might not be able to allow flowing of large amounts of water during concentrated rainfall, as well as in case of prolonged 227 fig. 5 digital terrain model (dtm) of the putignano territory showing three different geomorphological areas characterized: 1) karstic geomorphology with dolines, 2) sub-flat depressed geomorphology, 3) karstic valleys geomorphology. geological and geomorphological controls on flood phenomena in the putignano town, s italy found in cardinali et al. (1998) (tab. 1). in 1929 some people testified that rainfall caused such an intense flood in the “il basso” area that people and animals were saved using boats from the nearby monopoli village. the walls of the historical building "trullo" (fig. 8) keep the trace of the water level corresponding to the maximum depth (about 2.035 m.) reached by water in ephemeral lake (fig. 9). in tab 2 are reported the meteorological information for rainfall events occurred from 2000 to present day. the event that produced more damages occurred in september 2006 with a rainfall of 349 mm. the main precipitation started at 01.00 a.m., until 10.00 a.m. this event led to floods of the industrial area, countryside, and some zones of the town, causing serious damages and the death of one person. other floods of minor magnitude happened in 2008 and 2009. furthermore, from the 2015 to the present, important flash floods (up to 20 mm of water precipitated in less than 20 minutes) have been occurring annually. flash floods do not promote flooding in the karst valleys of the countryside, and are constrained mainly in the town (the 228 fig. 6 w-e geologic profile across the san cataldo, “il basso”, casa padule, and frassineto valleys (the trace of profile is reported in fig. 2) showing their fills. fig. 7 flooding of a doline (a), and of the san cataldo valley (b and c). tab. 1 floods occurred in the putignano territory in the 20th century; after cardinali et al. (1998). giannandrea p. et al. flooded areas are identified in fig. 9 with numbers 1, 3, 4 and 5). 5. urban expansion of the putignano town the urban structure of putignano has developed in three different historical periods corresponding to three distinct parts of the town: i) the original medieval nucleus; ii) the nineteenth-century orthogonal structure; iii) buildings developed from the post-war period up to the present time (fig. 8a). the medieval town (fig. 8b), originally closed in a circle of walls, consists of two concentric rings on the hill (highest point approximately 374 a.s.l.) around an original nucleus expanded between the 6th-7th century b.c. (primitive apulian settlement) and 1108. the first ring was built around the millstone and the church of san pietro between 1108 and 1158, after the concession made by boemondo di altavilla to benedictines of s. stefano abbey in monopoli; from this moment onwards, the community began its own social and religious organization. the cross-distribution of roads indicates a favorable relationship with the territory and a strategic position that affected the subsequent development. the knights of malta ruled putignano from 1317; the population increased and the second ring was completed in 1472 with the construction of the second town wall that was subsequently demolished in 1831, when the historical center was shaped in its current setting (fig. 8b). the nineteenth-century part was built close to the ancient nucleus and is characterized by two orthogonal roads, from the highest points up to the alluvial valley area to the north-east (fig. 8a). the nineteenth-century setting remained basically unaltered until the 1950s when some public building were built, such as the hospital, the parini and minzele schools, and the railway station. the railway station, built on the opposite side of the karts valleys in north-east, and the parini school are the most important buildings for the following expansion of the town (fig. 8a). a disorganized urban development started after the ‘50s in putignano, as well as in other towns in italy. indeed, despite the numerous urbanistic planning laws, in this period the town developed without a precise urban plan. 6. discussion and conclusions the geological structure of the subsurface, geomorphological features, flood events that occurred in the past and recent time, and stages of urban expansion of 229 fig. 8 tow map showing in a) the urban and industrial expansion of the putignano town, with elements of the geomorphology and quaternary deposits, and flood areas, and in b) details of expansion of the medieval town. geological and geomorphological controls on flood phenomena in the putignano town, s italy the putignano town have been described in the previous sections. the urban and industrial areas (fig. 8), during highand medium-magnitude flood events, were damaged by flooding events. the geological/ geomorphological characteristics of the putignano territory show a typical karst environment that can be subdivided into three morpho-structural subunits (fig. 5). these subunits are related to the development of the murge relief with e-w trending tectonic structures that allowed the formation of the central lowered area called sector 2 (fig. 5) occupied by a paleo-sea, in the frassineto and casa padule areas (fig. 10) during the pleistocene marine transgression. as a result of the sea level rise, we can identify the piezometric paleo-surface of the water table at a higher level in the carbonate massif of the murge. this suggests a perennial paleo-lake or, at least, a marshy environment, in the “il basso” locality (fig. 10), as a consequence of the rise of the piezometric surface. the present day morphological characters allowed us to identify the “il basso” and casa padule areas as a base level of extensive endorheic basins (figs. 2 and 5) that in winter season or during a highmagnitude rainfall events (for example 349 mm in 1-2 days; tab. 1) can develop in a large ephemeral lake (fig. 5). the medieval and nineteenth-century sectors of the putignano town were built on the highest portions of the karst territory, on the right side of the san cataldo valley (figs. 2 and 8). during modern expansion, some valleys in the northeast and southwest of the old town of putignano were filled by anthropic breccia deposits and new buildings (fig. 8). in this territory however, the urban expansion has not completely erased the morphologies of the karst valleys that remain buried. nowadays, these buried forms represent flooded areas during highmagnitude pluviometric events and an underground network of waters flows that infiltrate from the surface or leak from the pipes of the urban network. part of the industrial area was built on the bottom of the “il basso” area that may be submerged by water up to 2 m deep (fig. 8). by analyzing the floods data, it follows that alluvial phenomena occur for periods less than 30 years (tab. 1). particular attention must be placed to the very highmagnitude and very short-lived events, occurred annually in 2015, 2016 and 2017 (tab. 2), that caused the flooding of the urbanized areas identified in fig. 8 with numbers 1, 3, 4 and 5. these areas are located on buried alluvial valleys (fig. 2). the overlapping of the urbanizations on the geological-geomorphological map of the putignano town (fig. 8) shows that up to the first half of the twentieth century the town grew respecting precise urban guidelines and geological constraints (the town expands on a hill with calcareous bedrock). instead, after this period, an indiscriminate growth reveals the absence of an urban project: the town expands throughout the territory, occupying the valley areas. currently (area 5; fig. 8) we are assisting a continual consumption of the territory without an urban planning and accurate geological/ geomorphological analyses, increasing the hydraulic risk. a detailed geological map of quaternary deposits 230 tab. 2 floods occurred in the putignano territory from the year 2000 to present day. fig. 9 level reached by the 1929 flood detectable by preserved traces on the wall of a historical building (trullo). giannandrea p. et al. and landforms, as well as the survey of the urban expansion and anthropic deposits, may provide useful indications about the locations where floods effect will hit in the future (fig. 8). this tool appears to be essential in the perspective to mitigate the damage to people and infrastructure. acknowledgements we sincerely thank m.g. forno, and m. parise, l.a. dimuccio, and d. capolongo for their constructive comments and accurate revision of the early version of the manuscript. we wish to thank also m. schiattarella, p. ferretti and the editor-in-chief a. bertini for the final revision of the manuscript. this study benefited from the funding supported by fondi di ateneo ril 2011, 2013, 2015 (università degli studi della basilicata) granted to p. giannandrea. references akdim b., amyay m. (1999) environmental vulnerability and agriculture in the karstic domain: landscape indicators and cases in the atlas highlands, morocco. int j speleol 28b (1-4), 119-138. andriani g.f., walsh n. (2009) an example of the effects of anthropogenic changes on natural environment in the apulian karst (southern italy). environmental geology, 58, 313-325. anelli f. (1954) castellana. arcano mondo sotterraneo in terra di bari. comune di castellana-grotte, pp. 176. anelli f. (1962) le cavità con riempimento bauxitico di spinazzola (bari). atti congr. int. spel., bari-lecce -salerno, 5-12 ottobre 1958, 1, 201-215. argnani a., favali p., frugoni f., gasperini m., ligi m., marani m., mattietti g., mele g. (1993) foreland deformational pattern in the southern adriatic sea. ann. geog. 36/2, 229-247. azzaroli a., radina b., ricchetti g., valduga a. (1968) note illustrative della carta geologica d’italia: f° 189 “altamura”. serv. geol. d’it., pp. 22. baldassarre g., francescangeli r. (1987) osservazioni e considerazioni sulla inondazione del 6 novembre 1926 in bari e su un relativo deposito, mem. soc. geol. it., 37, 7-16. boenzi f. (1988) appunti sul paesaggio carsico pugliese. in: campanella (ed): 2° corso di speleologia di secondo livello (speleogenesi e morfologia carsica pugliese). regione puglia assessorato all’ambiente settore ecologia, federazione speleologica pugliese commissione nazionale scuole di speleologia della soc. spel. it., catellana grotte. bonacci o. (2004) hazards caused by natural and anthropogenic changes of catchment area in karst. nat hazards earth syst sci 4, 655-661. burri e., castiglioni b., sauro u. (1999) agriculture, landscape and human impact in some karst areas of italy. int. j. speleol. 26(1-4), 33-54. calò f., parise m. (2006) evaluating the human disturbance on karst environments in southern italy. 231 fig. 10 paleogeographic reconstruction of the putignano territory showing the areas occupied by the quaternary frassineto case padule sea, “il basso” lake and the ancient hydrographic network. geological and geomorphological controls on flood phenomena in the putignano town, s italy acta carsologica 35(2), 47-56. campobasso v., olivieri c. (1967) osservazioni sulla stratigrafia e sulla tettonica delle murge fra castellana grotte (bari) e ceglie messapico (brindisi). studi geologici e morfologici sulla regione pugliese, univ. bari, ist. geologia e paleontologia, 2, 120. carminati e., doglioni c. (2004) mediterranean tectonics. in encyclopedia of geology, elsevier, 135146. carminati e., negredo a.m., valera j.l., doglioni c. (2005) subduction-related intermediate-depth and deep seismicity in italy: insights from thermal and rheological modeling. physics of the earth and planetary interiors 149, 65-79. cardinali m., cipolla f., guzzetti f., lolli o., pagliacci s., reichenbach p., sebastiani c., tonelli g. (1998) catalogo delle informazioni sulle località italiane colpite da frane e da inondazioni. cnr cndci n. 1799, volume ii inondazioni. catasto delle grotte e delle cavità artificiali regione puglia 2013 elenco catastale delle grotte censite dalla fsp (aggiornato a marzo 2013. http:// www.catasto.fspuglia.it/tabella_grotte.jsp ciaranfi n., pieri p., ricchetti g. (1988) note alla carta geologica delle murge e del salento (pugliacentromeridionale). mem. soc. geol. it. 41, 449-460. colamonico c. (1917a) il pulo di altamura. mondo sotterraneo, 12 (4), 65-76. colamonico c. (1917b) il pulicchio di gravina. rivista geografica italiana, 24, 358-365. colamonico c. (1919-20) i così detti “puli” di ruvo. mondo sotterraneo, a. 15-16, 1-7, udine. colamonico c. (1919a) il “gurgo” di andria. boll. reale soc. geogr. it., fasc. 3-4, 225-229. colamonico c. (1919b) il pulicchio di toritto e la genesi dei puli nel barese. bollettino reale. soc. geografica it., 8, 578-595. corrado g., di leo p., giannandrea p., schiattarella m. (2017) constraints on the dispersal of mt. vulture pyroclastic products: implications to midpleistocene climate conditions in the foredeep domain of southern italy. géomorphologie: relief, processus, environnement, 23/2, 171-182. crescenti u., vighi l. (1964) caratteristiche, genesi e stratigrafia dei depositi bauxitici cretacei del gargano e delle murge; cenni sulle argille con pisoliti del salento (puglie). boll. soc. geol. it. 83, 285338. delle rose m. (2007) valutazioni dei rischi di allagamento per incremento degli eventi meteorici estremi in bacini endoreici della puglia centromeridionale. proc. conf. climatic changes and geologic risk in apulia, sannicandro di bari, 30/11/2007, 49-60. di geronimo i. (1970) geomorfologia del versante adriatico delle murge di se (zona di ostuni, brindisi). geologica romana, 9, 47-58. festa v. (1999) l’avampaese apulo nel quadro dell’evoluzione dell’appennino meridionale: la deformazione della piattaforma carbonatica apula nel settore murgiano (puglia, italia meridionale). tesi di dottorato, univ. di bari, pp. 122. festa v. (2003) cretaceous structural feature of the murge area (apulian foreland, southern italy). eclogae geol. helv., 96, 11-22. funiciello r., montone p., parotto m., salvini f., tozzi m. (1991) geodynamical evolution of an intraorogenic foreland: the apulia case history (italy). boll. soc. geol. it. 110, 491-425. gambini r., tozzi m. (1996) tertiary geodynamic evolution of southern adria microplate. terra nova. 8/6, 593-602. gams i, nicod j, julian m, antony e., sauro u. (1993) environmental change and human impacts on the mediterranean karsts of france, italy and the dinaric region. catena suppl 25, 59-98. giannandrea, p., marino, m., romeo, m., schiattarella, m. (2014) pliocene to quaternary evolution of the ofanto basin in southern italy: an approach based on the unconformity-bounded stratigraphic units. italian journal of geoscience, 133(1), 27-44. gutierrez f., parise m., de waele j., jourde h. (2014) a review on natural and human-induced geohazards and impacts in karst. earth science reviews, 138, 61-88. doi: 10.1016/j.earscirev.2014.08.002 iannone a., laviano a. (1980) studio stratigrafico e paleoambientale di una successione cenomaniano -turoniana (calcare di bari) affiorante presso ruvo di puglia. geol. rom., 19, 209-230 iannone a., pieri p. (1979) critical considerations on ‘‘calcareous tufa’’ of murge. new stratigraphical and paleoenvironmental data (in italian). geografia fisica e dinamica quaternaria 2, 173-186 iannone a., pieri p. (1982) caratteri neotettonici delle murge. geol. appl. idrogeol., 18/2, 147-159. laviano a., (1995) considerazioni preliminari sul significato paleoecologico e paleobiogeografico delle facies a rudiste nell’evoluzione sedimentaria della piattaforma carbonatica apula. atti mus. geol. paleont monfalcone, quaderno speciale 3, 51-64. lollino p., parise m., reina a. (2004) numerical analysis of the behavior of a karst cave at castellana grotte, italy. in: konietzky, h., (ed.) proc. 1st int. udec symp. “numerical modeling of discrete materials”, bochum (germany), 29 sept.-1 oct. 2004, pp. 49-55. lopez n., spizzico v., prise m. (2009) geomorphological, pedological, and hydrological characteristics of karst lakes at conversano (apulia, southern italy) as a basis for environmental protection. environmental geology, 58 (2), 327-337. luperto sinni e., reina a. (1996) nuovi dati stratigrafici sulla discontinuità mesocretacea delle murge (puglia, italia meridionale). mem. soc. geol. it., 51, 1179-1188. luperto sinni e., guarnieri g., laviano a., reina a. (1988) rudist and foraminifera assemblages in a santonian carbonatic succession of southeastern murge (apulia, italy). serbian geol. soc. spec. publ., 2, 9-15. luperto sinni e. (1996) sintesi delle conoscenze biostratigrafiche del cretaceo del gargano e delle murge. mem. soc. geol. it., 51/2, 995-996. mack g.h., madoff r.d. (2005) a test of models of 232 giannandrea p. et al. fluvial architecture and palaeosol development: camp rice formation (upper pliocene-lower pleistocene) southern rio grande rift, new mexico, usa. sedimentology, 52, 191-211. maggiore m.,pagliarulo p. (2004) circolazione idrica ed equilibri idrogeologici negli acquiferi della puglia. convegno uso e tutela dei corpi idrici sotterranei pugliesi, bari 21 giugno 2002. in geologi e territorio supplemento al n. 12004, 13-35. maggiore m., ricchetti g., walsh n. (1978) studi geologici e tecnici sulle pietre ornamentali della puglia: il “perlato svevo” di ruvo di puglia. geol. appl. idrogeol., 13, 299-317. martinis b. (1961) sulla tettonica delle murge nordoccidentali. rend. sci. fis. mat. acc. naz. lincei, 8/31 (5), 299-305. mossa m. (2007) ­ the floods in bari: what history should have taught. journal of hydraulic research, 45/5, 579-594. muscari m. (2016) il riutilizzo delle acque. fondazione geometri e geometri laureati milano, 17 giugno 2016 nicod j, julian m., anthony e. (1997) a historical review of man-karst relationships: miscellaneous uses of karst and their impact. rivista di geografia italiana 103, 289-338. orofino f. (1990) castellana-grotte: le vicende storiche di largo porta grande, itinerari speleologici, ser. ii, 4, 39-46, 1990. pace p., savino g. (1995) largo porta grande e la conca carsica di castellana-grotte, umanesimo della pietra-verde, 10, 35-44. parise m., gunn j. (eds) (2007) natural and antropogenic hazards in karst areas. geological society special publication, 279. geological society of london, london pp 202. parise m., pascali v. (2003) surface and subsurface environmental degradation in the karst of apulia (southern italy). environ. geol. 44, 247-256. parise m., benedetto l. (2018) surface landforms and speleological investigation for a better understanding of karst hydrogeological processes: a history of research in southeastern italy. in: parise m. gabrovsek f., kaufmann g., ravbar n. (eds.), “advances in karst research: theory, fieldwork and applications”, geological society of london, special publications, 466, p. 137-153. parise m., trisciuzzi m.a. (2007) geomechanical characterization of carbonate rock masses in underground karst systems: a case study from castellana grotte (italy). in tyc a. & stefaniak k. (a cura di), karst and cryokarst. studies of the faculty of earth sciences, university of silesia, 45, 227-236. parise m. (2006) geomorphology of the canale di pirro karst polje (apulia, southern italy). zeitschrift für geomorphologie n.f. 147, 143-158. parise m. (2008) elementi di geomorfologia carsica della puglia. atti del 45° corso cnss-ssi di iii livello “geomorfologia carsica” (a cura di m. parise, s. inguscio & a. marangella) grottaglie, 2-3 febbraio 2008, 93-118. parise m. (2009) lakes in the apulian karst (southern italy): geology, karst morphology, and their role in the local history. in: miranda, f.r. & l.m. bernard, (eds.) lake pollution research progress. nova science publishers, inc., new york, pp. 63-80. parise m. (2011) surface and subsurface karst geomorphology in the murge (apulia, southern italy). acta carsologica, 40 (1), 79-93. pieri p. (1980) principali caratteri geologici e morfologici delle murge. murgia sotterranea 2/2, 13-19 pieri p., festa v., moretti m., tropeano m. (1997a) quaternary tectonic of the murge area (apulian foreland southern italy). annali di geofisica, 40 (5), 1395-1404. pieri p., vitale g., beneduce p., doglioni c., gallicchio s., giano s.i., loizzo r., moretti m., prosser g., sabato l., schiattarella m., tramutoli m., tropeano m. (1997b) tettonica quaternaria nell'area bradanico-ionica. il quaternario, 10, 535542. reina a., parise m. (2004) geologia delle grotte di castellana: ipotesi speleogenetiche. ordine regionale dei geologi puglia, 1/2004, 3-14. ricchetti g. (1980) contributo alla conoscenza strutturale della fossa bradanica e delle murge. boll. soc. geol. it., 49, 421-430. ricchetti g., ciaranfi n., luperto sinni, e. monelli f., pieri p. (1988) geodinamica ed evoluzione sedimentaria e tettonica dell’avampaese apulo. mem. soc. geol. it., 41, 57-82. sauro u. (1991a) il carsismo delle alte murge (puglia, italia). itinerari speleologici, 5, 67-71. sauro u. (1991b) a polygonal karst in alte murge (puglia, southern italy). zeitschrift für geomorpologie, 35 (2), 207-223. sauro u. (2006) changes in the use of natural resources and human impact in the karst environment of the venetian prealps (italy). acta carsologica 35 (2), 57-63. schiattarella m., beneduce p., di leo p., giano s.i., giannandrea p., principe c. (2005) assetto strutturale ed evoluzione morfotettonica quaternaria del vulcano del monte vulture (appennino lucano). boll. soc. geol. it., 124, 543-562. servizio geologico d’italia (1988) carta geologica d’italia alla scala 1:100000, f. 190 monopoli, ispra, roma sulpizio r., zanchetta g., paterne m., siani g. (2003) a review of tephrostratigraphy in central and southern italy during the last 65ka. il quaternario, 16 (1), 91-108. tulipano l., fidelibus m.d., sappa g. (2008) groundwater protection in karst environment. proceedings of 8th international hydrogeological congress of greece athens 8-10 october 2008. urich p.b. (2002) land use in karst terrain: review of impacts of primary activities on temperate karst ecosystems. sci conserv. 198, 5-60. valduga a. (1965) contributo alla conoscenza delle murge baresi. studi geologici e morfologici sulla regione pugliese, 1, pp. 15. white w.b. (1988) geomorphology and hydrology of karst terrains. oxford university press, new york, p 464. williams p.w. (1993) environmental change and hu 233 geological and geomorphological controls on flood phenomena in the putignano town, s italy 234 man impact on karst terrains: an introduction. catena suppl. 25, 1-19. 234 giannandrea p. et al. ms. received: marz 30, 2018 final text received: december 4, 2018 available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 31 (2), 2018, 133 145 "sassi", the old town of matera (southern italy): first aid for geotourists in the "european capital of culture 2019" marcello tropeano 1 , luisa sabato 1-2 , vincenzo festa 1 , domenico capolongo 1 , claudio ivan casciano 3 , domenico chiarella 4 , salvatore gallicchio 1 , sergio giuseppe longhitano 5 , massimo moretti 1 , marco petruzzelli 1 , giusy schiuma 6 , luigi spalluto 1 , federico boenzi 1 , piero pieri 1 1 dipartimento di scienze della terra e geoambientali, università degli studi di bari aldo moro, bari, italy 2 dipartimento di biologia, università degli studi di bari aldo moro, bari, italy 3 dipartimento di scienze biologiche, geologiche e ambientali sez. scienze della terra, università di catania, catania, italy 4 department of earth sciences, royal holloway university of london, egham, uk 5 dipartimento di scienze, università della basilicata, potenza, italy 6 professional photographer and tour guide, matera, italy corresponding author: m. tropeano <marcello.tropeano@uniba.it> abstract: the old town of matera (southern italy) is an urban area included in the unesco world heritage list since 1993 and matera has recently been designated as european capital of culture 2019. since prehistoric times, the old town, called "sassi di matera" ("sassi" is the italian word for stones), has been spectacularly dug in a "soft rock" (a quaternary calcarenite). this rupestrian settlement is perched in the upper part of the right side of the "gravina di matera", a canyon cutting the so called "murgia materana", the barren rocky high in front of the town. an increasing number of tourists is attracted by itineraries crossing the "sassi di matera", and, due to the intimate connection between the old town and the geological anatomy of the area, each touristic itinerary could become an urban geotour or could be enriched by geological information. the aim of the present paper is to offer simple geological information to tourists who are visiting the old town of matera, giving them the opportunity to admire the amazing geology of the area and to be intrigued in understanding the development of the crossed landscape. keywords: geology; geotourism; sassi; gravina di matera; murgia materana 1. introduction the "sassi di matera", locally named the "rioni sassi" (sassi districts) or simply the "sassi", is the surprising rupestrian old town of matera, in southern italy, spectacularly dug in a "soft rock" (an easily workable limestone) and perched in the upper part of the right side of a canyon (the "gravina di matera"). since 1993 the sassi di matera, have been included in the unesco world heritage list with the following justification: "this is the most outstanding, intact example of troglodyte settlement in the mediterranean region, perfectly adapted to its terrain and ecosystem. the first inhabited zone dates from the palaeolithic, while later settlements illustrate a number of significant stages in human history". moreover, on 17 october 2014, the town of matera has been designated as european capital of culture 2019. due to the large volume of tourists inspired by cultural interests expected in matera, and since the old town is well known for being "carved into the rock", city tours may offer the perfect opportunity to divulge the culture of geology to non-expert audiences (sabato et al., in press). in this regard, the intimate connection of matera with geology is primarily suggested by the name "sassi" indicating the rupestrian districts representing the old town: "sassi" is the italian word for “stones”, and the old town of matera still conveys an idea of symbiosis with the original rocky landscape (fig. 1). in order to provide a "first aid" to non-specialists, the ambition of this article is to help tourists to read the territory hosting the town of matera by supplying some useful geological information. the geographical background in which the sassi districts developed is represented by the "murgia materana" (or "murgia di matera"), that is the rocky area in front of matera spectacularly cut by the "gravina di matera", the canyon formed after the gradual incision of the stream that still flows at the bottom of the rocky valley. the old town is perched on the right side of the canyon (figs 1 and 2), which is the main geographic element characterizing the landscape. without the presence of this canyon and of its two urbanized tributaries (the "graviglioni"), which now are the two main roads to enter in the sassi districts, the rupestrian town could not have existed (tropeano, 1992; 2003a; 2003b). since it is impossible to disregard the development of the gravina di matera from the geology of both the murgia materana and the surrounding clayey territory, this article: i) explains the meaning of some used local geographic terminologies and debunks some of the https://doi.org/10.26382/amq.2018.09 134 tropeano m. et al. common (geological) myths regarding matera; ii) describes the development of the murgia materana, basically realized in the last 2.5 millions of years (i.e. during the quaternary period); iii) explores the role that the water has played in this context, as a primary agent for the development of the hydrographic network (of which the gravina di matera is part), and, eventually; iv) shows how both the presence of water and the wide exposure of soft rocks along the slopes of the graviglioni have determined the early reasons for the urbanization of the sassi area. 2. preliminary warnings 2.1 terminological assistance one of the main difficulty that tourists face in matera is the use of local names to indicate some geographic elements (i.e. "gravina" for canyon). the name "murgia" (pl. "murge"), with the first letter in lowercase, was a widespread term in southern italy indicating a rocky hill. the term became a very used toponym that, associated to other words and capitalizing the first letter, has assumed a geographical meaning. for example, "timpone delle murge", "alta murgia", fig. 1 a) panoramic view of the canyon "gravina di matera" cutting the "murgia materana", i.e. the rocky region made up of carbonate rocks characterizing the area; b) detail of the sassi di matera (the old town of matera), i.e. the famous rupestrian settlement dug in the upper part of the right flank (on the left in the photo) of the "gravina di matera" canyon. geographically, left and right flank of a valley are defined in relation to the river flow direction. note the presence of two types of carbonate rocks along the flanks of the canyon: cretaceous limestone (k), older than 65 millions of years, below, and quaternary calcarenites (q), not older than 2.5 millions of years, above. the sassi di matera are dug in the quaternary carbonates, that are "soft rocks" (i.e. easily diggable rocks) geologically belonging to the "calcarenite di gravina" formation. source of the panoramic photo: https://www.panoramio.com/photo/39789706. author: giorgio galeotti. 135 first aid for geotourists in the "sassi di matera" "minervino murge", "murgia materana", represent well defined localities or territories. attention should be drawn to the plural term without specific local indications but with the first letter in uppercase (murge): it indicates the wide central area of apulia characterized by the presence of ancient karstic rocks and a series of terraced plateaux. apulia ("puglia", in italian) is the easternmost geographic region of southern italy forming the spoor and the heel on the "italian boot", the latter representing the italian peninsula (fig. 3a). it is important to underline that, administratively, matera and the murgia materana belong to the basilicata region, i.e. they do not fall in the puglia region, but considering both physical geography and geology of the matera area, the latter is physically part of the apulia foreland, i.e. the geological element in front of the southern apennines that roughly corresponds to the puglia region (figs 3b and 3c). the term "gravina" is used with different meanings. first of all, it is a generic term to indicate each canyon developed on the southwestern flank of murge. to indicate a specific one of these canyons, the first letter is in uppercase and the term gravina is followed by the name of a locality: i.e. gravina di matera (literarily: matera canyon). the same term gravina di matera indicates also the ephemeral stream flowing at the bottom of the canyon, and so the gravina di matera (the stream) flows in the gravina di matera (the canyon). another element to complicate the tourists life is that in the vicinity of matera there is a town named "gravina in puglia" or "gravina di puglia", which is indicated on the road signs simply as gravina. gravina (the town) is famous for its gravina (the canyon) that obviously is called "gravina di gravina" (literarily: gravina canyon). accordingly, the ephemeral stream running in the canyon is the gravina di gravina (the stream) in the gravina di gravina (the canyon) that characterizes gravina (the town). to create more confusion, along the walls of the gravina di gravina has been formally defined the "calcarenite di gravina" formation, the geologic term that regionally indicates the carbonate rocks in which the sassi di matera are carved (figs 1 and 2). therefore, moving in the sassi districts, tourists touch a soft-rock (a sedimentary rock that can be easily dug and used for buildings; andriani & walsh, 2010) locally called "tufo" or "tufi" (tufi is the plural of tufo), lithologically called calcarenite (lithified calcareous sand), and geologically belonging to the calcarenite di gravina formation. 2.2 fake geological news some improbable geological phenomena attributed to natural aspects of the territory derive from popular myths handed down from generations. one of these anecdotes is the widespread belief that the steep wall of the gravina di matera known as "tempa rossa" ("red wall"), a reddish portion of the upper side of the canyon fig. 2 aerial view of the murgia materana and the matera town with some of the toponyms used in the text. the green dotted line indicates the boundary between cretaceous (below) and quaternary (above) carbonate rocks; the yellow dotted line indicates the boundary between quaternary carbonates (below) and quaternary clay deposits (above). top of the hills (lanera, castle, and serra venerdì) are characterized by sand and gravel. the sassi districts were dug in the quaternary carbonates (i.e. the calcarenite di gravina formation). base image by google earth. in front of the town and visible from any panoramic position in the sassi districts, is a volcano that has been active in "historical old-times" (i.e. "not now but during the life of my grandfather's great-great-grandfather") (tropeano et al., 2016) (fig. 4). unfortunately, this old lore found formal truth in an old geography treaty, quoted in some relatively recent documents aimed at preventing citizens from natural hazards. actually, tempa rossa is only a subvertical wall of the gravina di matera, whose origin is due to the deepening of the watercourse favoured by the uplift of the region, as discussed in the following sections. its reddish colour is related to the presence of eluvial material coming from the flat top of the left side of the canyon; this material is 136 tropeano m. et al. fig. 3 a) structural sketch of italy showing the position of the spoor and the heel of the "italian boot"; they correspond to the apulia foreland (the green area), a geological term indicating the area that has not yet been reached directly by the apennines deformations. apulia (puglia region) is an administrative term; political boundaries of apulia do not correspond to geological boundaries of the apulia foreland; b) simplified geological map of southern italy (from pieri et al., 1997, mod.). note the position of matera inside the three units of the orogenic system (apulia foreland, bradanic trough, and apennines chain). geologically, matera belongs to the apulia foreland while, administratively, it belongs to the basilicata region. the murge area is the set of karst plateaux located in the middle of the apulia foreland, and the murgia materana represents an isolated karst hill of the murge area within clay-rich lands; c) simplified geological section crossing the southern italy (after sella et al., 1988). rich in iron and aluminum oxides (reddish residual substance due to the dissolution of the exposed carbonate rocks). moreover, no volcanic rocks crop out around the "volcano", and any geothermal anomalies have never been recorded along the gravina di matera. therefore the tempa rossa volcano does not exist and never existed in the matera area. another belief is that the gravina di matera could "absorb" earthquakes, despite many of the inhabitants who verbally report this theory believe that the gravina di matera is a sort of large fissure (a rift) due to an ancient earthquake. in geology, any break of the earth's crust is a mechanical discontinuity, which is called fault if the adjacent blocks move relatively each other creating a rocks displacement. this movement can release energy in the form of earthquakes, which propagate in the earth's crust. both the depth of the seismic source (at least several kilometers) and the nature and energy of the waves produced by an earthquake exclude that pellicular elements of the earth's surface, like a canyon, could "absorb" waves propagation. moreover, it has been observed that during the major disastrous earthquakes, the movement of the two blocks along the faults is of the order of decimeter/meter. this relatively "small" size of the displacement is absolutely not comparable with the gravina di matera current dimension, more than 100 m of both width and depth. finally, the youngest rocks (early quaternary in age, i.e. not older than 2.5 millions years) exposed along the two flanks of the canyon do not show significant displacements, even if some normal faults could be observed in the area (tropeano et al., 1994; festa et al., 2018) (fig. 5). anyway, there are rumors linking earthquakes to tempa rossa: "if the tempa rossa volcano becomes active again there will be a strong earthquake (poor us)!". luckily no earthquake may generate from an imaginary volcano! unfortunately, in addition to the proper attention and sensitivity for the correct management of the territory, the growing interest in the sassi and the murgia materana is leading to an exponential increase in "opinions" rather than "facts" about several phenomena and/or attributes of the area. these interpretations, which are not data-supported but amplified by social networks or self-published "studies", are turning into scientific truths. in this way, prehistoric rock falls could become boulders moved by old inhabitants to protect the entrance of some caves, and n-s striking fractures or natural rocky walls could become witnesses of solstice celebrations. as a consequence, many natural and small features of the area, or many anthropic choices linked to original natural peculiarities, are now attributed exclusively to the ingenious of prehistoric inhabitants 137 fig. 5 one of the few normal faults cutting both the cretaceous bedrock and the quaternary calcarenite. this fault can be observed from the square of the san pietro caveoso church, located in the lower part of sassi. according to festa et al. (2018), cretaceous carbonates are intensely fractured and affected by several faults but only a few of these structures propagate in the quaternary units. photo by v. festa. first aid for geotourists in the "sassi di matera" fig. 4 panoramic view of "tempa rossa", a name that means "red wall". people believe that it corresponds to an active volcano. actually, it is the highest wall of the gravina di matera where outcropping cretaceous limestones show a reddish colour, due to the presence of residual material rich in iron and aluminum oxides. photo by m. tropeano. and to their high capacity of transformation of the landscape, a fascinating but distorted reading of the superimposition of man on the natural features of the region ("tourists: be careful about the source of information!"). 3. the "murgia materana" in the geological framework of the apulia foreland the murgia materana is an isolated portion of the murge (fig. 6) and its development may be outlined in the context of the development of the entire apulia foreland. in particular, the area of matera with: i) its canyon (the gravina), ii) the almost barren karstic plateau cut by the canyon (the murgia materana), and iii) the clayey hills on which the modern districts spread (among others, the districts/hills named lanera, serra venerdì, serra rifusa) (fig. 2) synthesize all the geomorphological and geological features that can be recognized along the western edge of the murge. in this framework, a favourable geographic-geological opportunity to inhabit the region was offered by the urbanization of the upper part of the right side of the gravina di matera, with the excavation of a complex network of caves, tunnels and cisterns in the exposed rocks. from this original "residential strategy", the sassi di matera were born. the murge anatomy reflects a long geological history, whose documented field-evidences date back to about 140 million years ago, during early cretaceous times (ricchetti et al., 1988; spalluto et al., 2005). at that time, the region that was going to be the apulia foreland, was a wide shallow-marine inter-tropical area basically comparable to the present-day bahamas. there, on the apulia carbonate platform, carbonate muds, which gradually were becoming limestones, deposited over millions of years up to about 65 million years ago (up to the end of the cretaceous), when the platform underwent subaerial exposure. later, in the area now corresponding to the murge, limestones were tectonically displaced forming a horst and graben structure (pieri, 1980) in a domino faults array (festa, 2003). this structural configuration led the area to be characterized by topographic highs and lows (iannone & pieri, 1982; tropeano et al., 1997). susequently, at least from the beginning of the quaternary period (about 2.5 million years ago), this region was affected by subsidence (a slow dropping, in this case induced by the migration of the apenninic orogenic system) that caused the return of the sea in apulia creating a wide archipelago (tropeano & sabato, 2000; tropeano et al., 2002a; 2002b) (fig. 7a). the islands corresponded to the structural highs of the previously described faults system and comprised exclusively cretaceous limestone. these hard whitish rocks, that today characterize the murge karst landscape, were the bedrock of both the islands (one of the highest of which would became the future murgia materana) and the structural depressions (straits) among islands, such as the viglione graben (tropeano, 1992) (fig. 8). a more important and deeper seaway, the bradanic trough ("fossa bradanica"), connected the central-northern adriatic sea to the ionian 138 tropeano m. et al. fig. 6 structural sketch of the murge area (see fig. 3 for the location; from pieri et al., 1997, mod). the murgia materana is an isolated sector of the murge that records the quaternary geological development of the whole region. green areas are made up of cretaceous limestones and roughly correspond to the islands of the palaeo-murge archipelago, developed in this part of the apulia foreland at least from about 2.5 millions years ago (at least from the beginning of the early pleistocene)(see fig. 7). the calcarenite around old islands corresponds to the calcarenite di gravina formation, the soft rocks in which the sassi di matera are dug. this calcarenite derives from the lithification of shallow-marine and coastal carbonate sands deposited on the flanks of the islands during their drowning. in later times, the same areas were reached by clays and successively by sands and gravels coming from the apennines. the middle and upper quaternary uplift of the region determined the exhumation of the old islands and their subsequent erosion by the drainage network, including the "gravina di matera". yons. the valley of the bradano river, just south of matera, is the perfect example of both the phenomena: its erosion has locally reached the carbonate bedrock, creating a spectacular canyon (a gravina with subvertical walls) that contrasts with the clayey slopes of the hills of miglionico and matera (new town), representing the flanks of the fluvial valley just above the gravina of the bradano river (figs 8 and 9b). sea between the migrating apennines and the murge archipelago. the slow subsidence of the whole murge region caused the progressive submersion of the archipelago (fig. 7b). in this geographic context, coarsegrained coastal deposits formed by a mix of skeletal carbonate fragments (bioclasts, i.e. parts of shells of mollusks living in those coastal areas) and detritus eroded from the exposed limestones accumulated on the sides of the islands (tropeano & sabato, 2000; pomar & tropeano, 2001; mateu-vicens et al., 2008). after diagenesis, this compositional mixing (sensu chiarella et al., 2017) formed by biodetritic and lithic carbonate sands would became the easily-dug porous carbonate-rocks locally and commercially known as "tufo" and formally defined as "calcarenite di gravina" formation (figs 6 and 8). these soft-rocks, a few meters to several tens of meters thick, lie on the cretaceous limestones (harder rocks) and represent the bedrock on which the sassi districts developed (fig. 1). it should be noted that, at the moment of the sedimentation of deposits that would became these soft-rocks, the area was almost completely submerged by the sea and the still not existing gravina di matera stream had not yet cut the murgia materana (fig. 7b). about 1.5 million years ago there was the maximum rise of the sea on the islands of the palaeo-murge archipelago; this phenomenon left only the highest reliefs uncovered by the sea, including the flat culmination of the future murgia materana (fig. 9). at the same time the detritus brought by rivers running in the apennines began to fed the bradanic trough seaway, which was progressively reached by offshore clays and filled with coastal sands and gravels (pieri et al., 1996; sabato, 1996; sabato et al., 2004). these same sediments also reached areas of the old archipelago, filling all the straits located between the old islands; the latter were almost completely buried by sediments except for the most elevated ones (tropeano et al., 2002a; 2002b) (fig. 7c). accordingly, about one million years ago, almost the entire region was a flat area, except for the protruding culmination of the old islands, one of which was the topmost part of the present-day murgia materana (fig. 9a). this is the geological "moment" when the watercourse that would became the present-day gravina di matera stream, as well as the entire hydrographic network that characterizes the murge area, established (gioia et al., 2011). at the same time, the region began to suffer a still active tectonic uplift (doglioni et al., 1994; 1996), which would progressively brought: i) the murge and the culmination of the murgia materana to exceed 500 m of altitude, ii) the drainage network to dissect the flat area, now at more than 400 m of altitude (fig. 9b), where watercourses began to develop, and iii) the ionian sea to retreat towards the present-day metaponto coastal plain. with the beginning of the regional uplift, the rivers running on sands and gravels of the alluvial plain progressively cut these deposits, reaching the underlying clays. locally, the drainage network reached deeper and more ancient carbonate rocks too, creating the canyons locally called "gravine" (the plural of "gravina"). in areas where the drainage network has not yet reached the deep bedrock, fluvial valleys develop in clays with sections much wider than those ones of can 139 first aid for geotourists in the "sassi di matera" fig. 7 development of the apulia foreland during the quaternary within southern italy. note the development from the palaeo -murge archipelago to the present-day murge and the position of the matera area in the three reported different steps. during the quaternary, the region was affected at first by subsidence and, later, by uplift. a) beginning of the early pleistocene; b) middle of the early pleistocene; c) end of the early pleistocene beginning of the middle pleistocene. 4. the "gravina di matera" the gravina di matera is a rocky valley deeply cutting the "soft" quaternary calcarenites and the underlying "hard" cretaceous limestones (respectively q and k in figs 1 and 5). it is worth noting that, by definition, the gravina is a canyon cut by the watercourse that still flows at its bottom. the width of the valley is linked to the long and complex phenomenon of recession of the slopes and should not be imagined as originating from a wide river progressively reduced to the present-day stream. indeed, all the valleys start out as small and narrow v-shaped incisions; the lowering of the base level of the watercourse led their progressive deepening, causing the retreat of the flanks (mainly due, along canyons, to the frequent collapse of the rocky walls) and the subsequent valley expansion. the original course of the stream creating the gravina di matera developed on a sandy-gravelly alluvial plain, and ran at the toe of the topmost part of the north-western corner of the murgia materana (fig. 9a). very soon, the deepening of the watercourse allowed to cut the buried edge of the ancient island, firstly reaching the soft-rocks of the calcarenite di gravina formation and, successively, the cretaceous limestones (fig. 9b). the boundary between these two different types of carbonate rocks can be identified at the base of the sassi (fig. 2) and, on the other side of the gravina di matera (figs 1 and 5), just below the rupestrian churches of the belvedere (the town’s panoramic lookout, part of the all tourist itineraries) (figs 2 and 9b). unlike the other gravina-like canyons, which developed along dip (i.e. according to the exposed slope of the flank of the exhumed old island), the gravina di matera incised the flank of the exhumed island along strike (i.e. perpendicular to the buried old slope) (fig. 8). this led to a different exposure of the rocks on the opposite sides of the gravina di matera, which is particularly 140 tropeano m. et al. fig. 8 schematic geological map and section of the murgia materana (see fig. 6 for the location; from beneduce et al., 2004, mod.). note the position of matera, at the same time on the rocky flank of the gravina and on clay, sand and gravel of the top of the hill. clear considering the thickness of the calcarenite di gravina formation, thin in front of the sassi districts and thick in the sassi themselves (figs 1b and 9b). once the stream reached the hard bedrock, it progressively adapted its course to the trend of the main fracture zones of the cretaceous limestone, developing a slightly angular drainage network (beneduce et al., 2004). at present, the gravina shows either straight sections (mainly oriented about ne-sw and nw-se) with flanks having symmetrical slope profiles, or sinuous stretches (meanders) with flanks having asymmetric slope profiles (tropeano, 1992). several suspended dry valleys represent ephemeral tributaries unable to reach the base level of the gravina di matera. even the so-called graviglioni, now identified into the two main roads going down the sassi, were two tributaries with suspended valleys on the gravina di matera (fig. 2). soft-rocks of the calcarenite di gravina formation crop out extensively on the sides of these two tributaries and led to the easy and wide development of the peculiar urban fabric of the sassi districts. the suspended valleys are connected to the gravina by means of jumps (knickpoints) acting like waterfalls during main rainfalls; at the base of jumps some evorsion cavities, called potholes (cylindrical holes in rock) or giant's pots, are present (evorsion is the erosion of rocks due to vortices of water). these potholes can also reach relatively large dimensions (several tens of meters in diameter), such as, for example, along the jesce stream (torrente jesce), where some ponds probably represent old "giant's pots". numerous smaller pots are visible on the right side of "masseria passarelli" ford, where the gravina di matera stream locally expands its valley partly running in clays. moreover, some isolated reliefs of conical shape, shoving variable sizes and heights between some tens to one hundred of meters, are linked to the development of the drainage network of the gravina di matera. two of these reliefs are well recognizable in the sassi districts: the most evident is represented by the "monterrone" (fig. 10), the relief hosting the "madonna dell'idris" church that appears isolated from the slope of sassi through an old and abandoned meander of the canyon (fig. 2); the less evident relief is represented by the "civita", the hill on whose side stands the cathedral (figs 1 and 2), which is isolated by another abandoned meander, a residual segment of which partly corresponds to "piazza san francesco" and "via ridola". other prominent isolated reliefs are represented by the rocky hill hosting on top the "madonna degli angeli" church and by the rocky hill located in front of the "madonna delle vergini" church, both clearly visible from high panoramic points of the sassi districts (fig. 11, see also fig. 2). as mentioned above, these isolated reliefs are evidence of abandonment of old segments (meanders) of the canyon, later reworked by the hydrographic network (fig. 2). 141 first aid for geotourists in the "sassi di matera" fig. 9 a) stratigraphic scheme showing the original distribution of quaternary deposits on the southwestern flank of the palaeoisland corresponding to the future murgia materana. note the position of both the bradano river and the gravina di matera stream before they reached the carbonate bedrock. red dotted lines indicate the progressive development of valleys. b) schematic geological section (not to scale) of the southwestern flank of the murgia materana, showing the present-day valleys (after beneduce et al., 2004). matera developed on the flank of the gravina, due the presence of both "easily diggable" soft rocks (the calcarenite di gravina formation) and water in the upper part of the hill. 5. geology and urban development of sassi in general, it is not easy to perceive the original reasons for the establishment of prehistoric settlements representing the origin of future cities. at the beginning, the choice must have been mainly linked to the presence of favourable geographical conditions, often a consequence of the interconnection between the geological nature of the territory, climate, presence of natural defenses, and availability of resources (water in the first place). later, ideal conditions for commercial exchanges or military defenses became among the primary reasons for the historic expansion of towns (gisotti, 2016). this "recent" development has made it difficult to read the original natural requisites that favoured the first step of settlement of very old urban areas. some of the previously described geological and morphological elements of the matera area have been crucial for favouring the peculiar human colonization of this territory. at the beginning, karst cavities developed in the cretaceous limestone, like the famous "grotta dei pipistrelli" (cave of bats) facing the gravina di matera, offered safe refuge during the palaeolithic. this archeological period covers a time span running between 2.58 millions and 11,700 years ago and almost coincides with the geological period named pleistocene. the palaeolithic remains in matera are not older than 0.8 million years (boenzi et al., 2017) and this is confirmed by the age of deposits connecting the filled bradanic seaway to the murgia materana (fig. 7c). in fact, before the "construction" of this sedimentary bridge, the murgia materana was an island which was impossible to reach by men of the early palaeolithic. however, the first human settlements began in the 142 tropeano m. et al. fig. 10 the isolated conical relief of "monterrone" hosting the "madonna dell'idris" church. photo courtesy of silvia zapelloni. fig. 11 isolated conical reliefs within the gravina di matera canyon, in front of sassi. note that the thin quaternary succession hosting the "madonna delle vergini" church represents the uppermost wedge of the calcarenite di gravina formation (q) onto the flank of the murgia materana palaeoisland (compare it with the position of the belvedere in fig. 9b). photo by g. schiuma. neolithic period (11.700 to 6500-4000 years bp), when the first "entrenched" villages developed on some flat areas of the murgia materana (rota, 2011), characterized by a thin soil covering the calcarenite bedrock. the presence of soft-rocks at shallow depth allowed the excavation of trenches and the embedding of wood piles in the ground. moreover, the water was relatively abundant in the area; in fact, even in dry periods, the torrente jesce (the jesce stream, a tributary of the gravina di matera stream) (figs 8 and 11) shows a series of deep ponds, represented by some large evorsion pots called "jurio", the dialectal term for whirlpool. from the bronze age (5300-3200 years bp) the social life moved on the right side of the gravina, in particular on the so-called civita, a morphological high now incorporated in the sassi with the cathedral (rota, 2011) (figs 1 and 2). this side of the gravina di matera was characterized by perennial water sources, represented by diffuse but hidden springs placed at the base of the sandy deposits of the hill of the castle of matera (the clay hill in figs 2, 8 and 9b). here the aquifer lies onto the clays that cropped out along the present-day "via lucana" (lucana street). these springs, along with those pouring from the other hills of the new town of matera and that are now completely buried below the buildings and almost forgotten by the local people, also fed the graviglioni, the two tributaries of the gravina di matera crossing the sassi districts. in the sassi, the run -off water was collected in a lot of small cisterns dug into the rock. then, also the water of the springs as well was collected in large cisterns. one of these cisterns is the "palombaro lungo", dug in the upper part of one of the graviglioni and located in the ground of the main square of matera ("piazza vittorio veneto"). in the same area, a historical fountain was fed by the capture of the water of the same springs. the phenomenon of the development of the anthropization of the sassi area, as well as the presence of water, was also favoured by the particular morphology of the right side of the gravina di matera. this side is favourably cut by the graviglioni and by the abandoned loop that isolates the monterrone ("madonna dell'idris" church) (fig. 10), incisions that allow exposing long sections of calcarenite on easily accessible slopes. the development of the sassi did not reach the bottom of the gravina because the lower limit of the urbanization was influenced by the presence of the cretaceous limestone that crops out from the stream bed up to the base of the sassi districts (festa et al., 2018) (fig. 12, see also figs 1 and 2). 6. conclusions before the human colonization, the natural landscape of the matera area had been shaped on an old island of the palaeo-murge that was: i) mantled by calcarenite, ii) almost completely buried by clayey and sandy-gravelly sediments, and, eventually, iii) largely exhumed by erosion. near the old island, after the easy erosion of the thin quaternary cover, flanks of the ancient morphostructural high have been exposed again (i.e. the rocky slopes of the murgia materana either dipping toward north, along the matera-taranto road, or toward the southwest, along the "matera sud" connecting road). simultaneously, far from the old high, the erosion molded the gentle hills where the most recent districts of matera developed since the '50s. these hills, with their clayey sides and flat sand-gravelly top, characterize the whole province of matera, i.e. every village of the bradanic trough. in this scenario, the course of the stream that today flows at the bottom of the gravina di matera was defined when the area was a flat sandy-gravelly alluvial plain, whose remnants are today represented by the top of the hills in the new town, at about 425-440 m of altitude. the deepening of the watercourse induced by regional uplift 143 fig. 12 group of researchers and students from the university of natural resources and life sciences of vienna (austria), discussing about the downward expansion of sassi. the boundary between the calcarenite di gravina formation (q), above, and the cretaceous limestone (k), below, represents the limit of the urbanization (dotted line). compare with the dotted line in fig. 1 and with the green dotted line in fig. 2. photo courtesy of franz ottner and his students. first aid for geotourists in the "sassi di matera" caused the stream to reach the bedrock, and to cut the buried western edge of the old island and its southern flank. the erosion of the main watercourse (i.e. the gravina di matera stream) and of its tributaries (i.e. the graviglioni) exposed wide and gentle slopes in the middle-upper part of the right flank of the rocky valley (the gravina di matera canyon) molded on the calcarenite di gravina formation. this latter was an easy-diggable rock that favoured the creation of rupestrian houses frontally closed either by a simple wall with a door (and a window above) or by an entrance/living room passing to the cave. moreover the urbanization of the area was also possible thanks to the presence of water, that, emerging along the clayey and sandy-gravelly hills located above the sassi, was stored in small (domestic) and very big (urban) dug cisterns. in conclusion, the sassi di matera represent an extraordinary example of how pre-existing physical features and human imprints can live together in close connection, often ignored or underestimated. many ancestral human choices have been determined by the geological nature of the territory and by its geography, which has unconsciously pushed humans to assume peculiar urban solutions. therefore, the keys to read the landscape, especially where the natural elements are still evident, cannot ignore the knowledge of the physical substrate on which humans have superimposed their activity. from this point of view, the sassi di matera represent a spectacular geological training ground. acknowledgements this work is dedicated to all friends, students and colleagues who over the years have had the patience to listen and discuss the covered topics. thanks to them, over time these arguments have assumed a popular form that we hope will be useful to the neophyte. among our friends, a dear memory goes to mario tommaselli, whose enthusiasm and teaching we hope will emerge from the reading of this work. many thanks to marco pantaloni and vincenzo pascucci for their comments to the original manuscript, and to adele bertini and andrea sposato, who patiently have waited the submission of this work to amq. where indicated, the photos are the property of the authors and cannot be reproduced without explicit request. research funds were granted to m. tropeano by the bari university (fondi di ateneo "ricerche stratigrafico/sedimentologiche di base ed applicate per il riconoscimento, la gestione e la tutela delle georisorse e dei beni storico/culturali e geoambientali" 2012, 2014). references andriani g.f., walsh n. (2010) petrophysical and mechanical properties of soft and porous building rocks used in apulian monuments (south italy). geological society, london, special publication, 333, 129-141. beneduce p., festa v., francioso r., schiattarella m., tropeano m. (2004) conflicting drainage patterns in the matera horst area, southern italy. physics and chemistry of the earth, 29, 717-724. doi:10.1016/j.pce.2004.03.009 boenzi f., capolongo d., lionetti g. (2017) il paleolitico nell'area materana nel contesto geologico ambientale. collana parcomurgia, parco della murgia materana, pp 95. chiarella d., longhitano s.g., tropeano m. (2017) types of mixing and heterogeneities in siliciclasticcarbonate sediments. marine and petroleum geology, 88, 617-627. doi:10.1016/j.marpetgeo.2017.09.010 doglioni c., mongelli f., pieri p. (1994) the puglia uplift (se-italy): an anomaly in the foreland of the apenninic subduction due to buckling of a thick continental lithosphere. tectonics, 13, 1309-1321. doglioni c., tropeano m., mongelli f., pieri p. (1996) middle-late pleistocene uplift of puglia: an "anomaly" in the apenninic foreland. memorie della società geologica italiana, 51, 101-117. festa v. (2003) cretaceous structural features of the murge area (apulian foreland, southern italy). eclogae geologica helvetiae, 96, 11-22. festa v., sabato l., tropeano m. (2018) 1:5,000 geological map of the upper cretaceous intraplatformbasin succession in the "gravina di matera" canyon (apulia carbonate platform, basilicata, southern italy). italian journal of geosciences, 137(1), 1 -13. gioia d., sabato l., spalluto l., tropeano m. (2011) fluvial landforms in relation to the geological setting in the "murge basse" karst of apulia (bari metropolitan area, southern italy). journal of maps 7(1), 148-155. doi: 10.4113/jom.2011.1136 gisotti g. (2016) la fondazione delle città. le scelte insediative da uruk a new york. carocci editore, roma, pp 559. iannone a., pieri p. (1982) caratteri neotettonici delle murge. geologia applicata e idrogeologia, 18, 147 -159. mateu-vicens g., pomar l., tropeano m. (2008) architectural complexity of a carbonate transgressive systems tract induced by basement physiography. sedimentology, 55(6), 1815-1848. pieri p. (1980) principali caratteri geologici e morfologici delle murge. murgia sotterranea, 2, 13-19. pieri p., festa v., moretti m., tropeano m. (1997) quaternary tectonic activity of the murge area (apulian foreland, southern italy). annali di geofisica, 40, 1395-1404. pieri p., sabato l., tropeano m. (1996) significato geodinamico dei caratteri deposizionali e strutturali della fossa bradanica nel pleistocene. memorie della società geologica italiana, 51, 510-515. pomar l., tropeano m. (2001) the calcarenite di gravina formation in matera (southern italy): new insights for coarse-grained, large-scale, crossbedded bodies encased in offshore deposits. aapg bull., 85, 661-689. ricchetti g., ciaranfi n., luperto sinni e., mongelli f., pieri p. (1988) geodinamica ed evoluzione sedimentaria e tettonica dell’avampaese apulo. memorie della società geologica italiana, 41, 57-82. rota l. (2011) matera. storia di una città. edizioni giannatelli, matera, pp 342. 144 tropeano m. et al. sabato l. (1996) quadro stratigrafico-deposizionale dei depositi regressivi nell’area di irsina (fossa bradanica). geologica romana, 32, 219-230. sabato l., tropeano m., festa v., longhitano s.g., dell'olio m. (in press) following writings and paintings by carlo levi to promote geology within the "matera-basilicata 2019, european capital of culture" events (matera, grassano, aliano southern italy). geoheritage. doi: 10.1007/s12371-018-0281-4 sabato l., tropeano m., pieri p. (2004) problemi di cartografia geologica relativa ai depositi quaternari nel f° 471 irsina. il conglomerato di irsina: mito o realtà? alpine and mediterranean quaternary, 17 (2/1), 391-404. sella m., turci c., riva a. (1988) sintesi geopetrolifera della fossa bradanica (avanfossa della catena appenninica meridionale). memorie della società geologica italiana, 41, 87-107. spalluto l., pieri p., ricchetti g. (2005) le facies carbonatiche di piattaforma interna del promontorio del gargano: implicazioni paleoambientali e correlazioni con la coeva successione delle murge. bollettino della società geologica italiana, 124, 675-690. tropeano m. (1992) aspetti geologici e geomorfologici della gravina di matera “parco archeologico storico naturale delle chiese rupestri del materano”. itinerari speleologici, 2, 19-33. tropeano m. (2003a) matera: una serie di geositi urbani o una città geosito? geologia dell’ambiente, sigea, suppl. 1/2003, 231-238. tropeano m. (2003b) il parco archeologico, storico, naturale delle chiese rupestri del materano (un ricco parco geologico regionale). geologia dell’ambiente, sigea, suppl. 1/2003, 239-254. tropeano m., boenzi f., capolongo d., festa v., pieri p., sabato l., schiuma g. (2016) ultime notizie da matera: tempa rossa non è un vulcano! rudimenti di geologia per turisti in visita ai sassi e al parco della murgia materana. gta, rivista dell'ordine dei geologi di basilicata, 25, 45–53. tropeano m., marino m., pieri p. (1994) evidenze di tettonica distensiva plio-pleistocenica al margine orientale della fossa bradanica: l’horst di zagarella. alpine and mediterranean quaternary, 7, 597606. tropeano m., pieri p., moretti m., festa v., calcagnile g., del gaudio v., pierri p. (1997) tettonica quaternaria ed elementi di sismotettonica nell’area delle murge (avampaese apulo). alpine and mediterranean quaternary, 10(2), 543-548. tropeano m., sabato l. (2000) response of pliopleistocene mixed bioclastic-lithoclastic temperatewater carbonate systems to forced regressions: the calcarenite di gravina formation, puglia, se italy. geological society, london, special publication, 172, 217-243. tropeano m., sabato l., pieri p. (2002a) filling and cannibalization of a foredeep: the bradanic trough, southern italy. geological society, london, spec. publ., 191, 55-79. tropeano m., sabato l., pieri p. (2002b) the quaternary "post-turbidite" sedimentation in the southapennines foredeep (bradanic trough-southern italy). bollettino della società geologica italiana, volume speciale 1, 449-454. 145 first aid for geotourists in the "sassi di matera" ms. received: june 11, 2018 final text received: august 29, 2018 146 amq61 panarello mietto.pub � �� � �available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 30 (2), 2017, 105-123 can it be an actual human fossil footprint? the "combined method" helps to give an answer adolfo panarello1, paolo mietto2 1 dipartimento di scienze umane, sociali e della salute, università degli studi di cassino e del lazio meridionale, cassino (fr), italy 2 dipartimento di geoscienze, università degli studi di padova, padova, italy�� � corresponding author: a. panarello <adolfo.panarello@unicas.it>� abstract: recent technological improvements and the growing precision of surveys and analytical procedures together with the growing interest in hominid palaeoichnological traces demand verification of all track-like impressions, especially those which are supposedly human. strict analysis and objective interpretations are increasingly necessary for those hollows which have been too hastily recorded as actual human footprints. in some specific environments, such as quarries or other archaeological sites which have been and are still being continuously altered by natural agents (such as eustatic movements, or weathering/aeolian phenomena, or geochemical processes), the number of structures which mimic the shape of human footprints is incredibly high and can lead to false interpretations. here we try to improve a successfully used method to re-analyze and reject the actuality of the supposed human fossil footprints from the valsequillo basin (mexico) by combining it with well-known and tested forensic methods of gait analysis. we think the new method that we are calling combined method (cm), enables scientists to gain a better understanding of wether a hollow on the ground can actually be a human footprint or not, even in cases where not all its contour details or anatomical landmarks are preserved or recognizable. keywords: human ichnology, human footprints, pseudo-track analysis. 1. introduction a simple glance at the world-wide hominid palaeoichnological record is sufficient to realize that only a few sites are scientifically studied and exhaustively documented. other sites are only known through some folk tales or brief mentions in some papers (avaleyraarroyo de anda, 1950; houck et al., 2009; lockley & roberts, 2004; lockley et al., 2008; lockley et al., 2009; lockley & rodríguez-de la rosa, 2009; quevedo-lara, 1998; rodríguez-de la rosa et al., 2004; rodríguez asensio-noval fonseca, 2012: 226). furthermore, many other ichnological and/or palaeontological sites such as terra amata (de lumley et al., 2011; goudet-ducellier, 1987; hadingham, 1985), happisburg(ashton et al., 2014), vértessz�l�s (fluck, 2011; kretzoi&dobosi, 1990; bridgland et al., 2006; visy et al., 2003), sierra tarahumara (inah, 2011), kenfig sands (bennett et al., 2010), rhodes island (bromley et al., 2009; milàn et al., 2005) and bakala region (marquer, 1960) are still enveloped by a dense cloud of doubts about their validity as actual human ichnosites. for these reasons an objective revision of the most ambiguous evidence and unsatisfactory documentation available has made the necessity arise to have a final, complete and scientifically based hominid-palaeoichnology record. the mentioned necessity became stronger after the well-known episode of the valsequillo basin (mexico) where some depressions in the ground were first interpreted as human and animal footprints (gonzález et al., 2006a, 2006b) and then after further studies, they were shown to be just simple signs left by quarrymen using metallic tools within a quarry area (morse et al., 2010). the scientific method used to prove and reject the mistaken interpretation was elaborated by a team (morse et al., 2010; morse, 2010) taking their stand on the fact that the most important anatomic landmarks of the human foot, although influenced by the structure of the middlefoot and/or by the nature of the ground, cannot significantly change their position from the areas of maximum plantar pressure located within the footprint area. such positions, as well known, match those in which the depressions on the ground are deeper, i.e. in the areas corresponding to the heel, to the heads of the metatarsal bones i and ii and to the hallux. the method by morse et al. was very innovative because it is based on baropodometric observations and frees any analysis from the strict positioning of anatomical landmarks of the human foot (which are not always visible or preserved) in some fixed geometrical positions and focuses on the relative depths inside footprints, which must be coherent with the displacement vectors of body-weight during walking. moreover, the deepest zones are enclosed by the contour of the footprint and can be included within an ellipse inscribing the complete foot. in the new scheme of evaluation, 5 main proposed landmarks also seems to go over some eventual trackmaker's deformations capable of misleading scientists (morse et al., 2010). how� � �� � � 106 panarello a., mietto p. ever, such a technique to verify human footprints can be applied only on «any potential footprint that would be considered complete, that is heel to toes, without regards to its anatomical definition» (morse et al., 2010). here we try to go beyond this limit and to improve the mentioned method by trying to make it applicable to each footprint-like hollow. for this purpose we elaborated a new method, called "combined method" (cm), by combining the described technique with other methods of analysis which have proved successful in forensic environments and which appear easily applicable, i.e. those by wilkinson et al. (1995), kennedy et al. (2003) and berge et al. (2006). 2. the combined method (cm) although based on the same basic principles of the method elaborated by sarita amy morse and her colleagues in 2010 (morse et al., 2010), the "combined method" (cm) (fig. 1) is an improvement as it has fewer limitations and can be applied to each depression on the ground, even when its contour is not completely preserved. furthermore, although with different degrees of approximation, the cm permits the creation and management of a longitudinal axis of the imprint which can be aligned to the major axis of the ellipse designed by the same morse et al. 's method even when its proximal and/or distal margins are lost. in this way the ellipse including the imprint (emor) can be oriented so that it matches the actual orientation of the potential human footprint and this enables the deepest zones to be located more precisely. moreover, as the cm can also be applied to some borderline cases each depression can be contextualized within a gait pattern by identifying a well-defined line of progression. the sharpness of the cm is directly proportional to the amount of available and visible details inside the potential footprint, but it always permits the determination that if at least the hollow can be compatible or not with an actual human footprint. finally, the emor can be divided into further subsets, which are very useful to identify and to analyze some diseases of the trackmakers' foot (panarello, 2016). the following is an explanation on how the cm works. after having checked if the hollow to be studied is located on the former surface of a stratigraphic layer, if all of the geological, chronological, taphonomic and morphostructural conditions of compatibility are fully satisfied (panarello et al., 2017), it is possible to begin the application of cm by tracing all the visible details of the potential human footprint and locating at least two notable points both on the lateral and medial side. such points must indicate the widest and the narrowest part of hypothetical footprint's contour. the same points will be indicated as am and al if referred, respectively, to the medial and lateral tips of the hypothetic forefoot (ball zone) and as tm and tl if referred, respectively, to the medial and lateral tips of the hypothetic hindfoot (heel zone). this allows for an initial basic evaluation of the depression because in an actual human footprint amal is always a greater value than tmtl. if the entire contour of the foot is visible it must be traced according to the scheme by kennedy et al. (2003) marking the convex hull of the footprint, i.e. the complete contour of the footprint without toe impressions. so am and al will match respectively, the medial and lateral edges of the ball corresponding to the heads of the 1st and the 5th metatarsal bone. in the same way, tm and tl will respectively match, the medial and the lateral edges of the heel. as a consequence amal corresponds to the max width of the forefoot and tmtl is to the max width of the heel. by continuing to apply kennedy et al. 's method (kennedy et al., 2003) we can draw the medial tangent (tanm) to the contour passing through am and tm and the lateral tangent (tanl) to the contour passing through al and tl. such tangents intersect at a point outside the footprint, which is located behind the heel. the bisector of the angle between tanm and tanl is the longitudinal axis (lax) of the footprint. lax is the real axis of the footprint when its complete contour is visible and it generally fig. 1 the combined method scheme (reworking and combination from wilkinson et al., 1995; kennedy et al., 2003; morse et al., 2010). � �� � � 107 the "combined method" to validate human footprints passes through 2nd and 4th toe in a normal foot (d’août & aerts, 2008). when the contour of the footprint is not completely preserved, lax must be considered as a virtual axis, which is fully working in the cm, as it never falls out of the zone closed by the 2nd and the 4th toe even when it cannot fully express the angular reality. in fact, it does not distort the cm scheme since it is not based on specific anatomical positions but rather on areas of compatibility. taking into account that the heel-strike is the detail which is almost always present in a human footprint, we thought of choosing it as a basic landmark, its rearmost point crossed by lax as indicated by x. finally, the line crossing x and normal to lax was considered as the base-line and indicated by bl. the next steps are the correct positioning of the major axis of the emor so that it matches the lax and specifies the length of the major axis. a further step is to place a variant of the rectangular and tripartite grid (rewil) used by wilkinson et al. (1995) and by mccrory et al. (1997) in their methods. several cases may arise: case a (at least the longitudinal contour of the footprint is visible, with or without the imprint of the hallux) (fig. 2) this is the luckiest case, because it is very easy to identify the lateral and medial edges, to draw the corresponding tangents, to identify x and bl and to place the lax making it coincide with the major axis of emor. the only problem to solve is determining the length of the major axis of the emor. if the imprint of the hallux is preserved it is easy to draw the rewil by placing one of its bases on the bl and by drawing the other parallel base in such a way that it passes through the most distal point of the footprint which is clearly identifiable on the frontal tip of the hallux. if the imprint of the hallux is not preserved we can determine an approximate major axis length by searching for it among the values in table 1 or taking into account the dimensional proportions of the foot as indicated by the lengths of the tarsal, metatarsal fig. 2 samples of footprints related to case a. � �� � � panarello a., mietto p. and phalangeal bones. such dimensions are, respectively, 51%, 26% and 23% of the total foot length. in australopithecus afarensis, the same proportions are, respectively, the 38%, the 32% and the 30% of the total foot length (klenerman-wood, 2006: 49; tuttle at al., 1991b). the dimensional values in table 1 refer to hominids of which at least one fossil footprint has been discovered, measured and verified as actual. of course, such selection must be made strictly taking into account the chronological age of the potentially trampled surface. case b (heel-strike imprint is visible but the distal margin of the footprint isn’t preserved) (fig. 3) in this second case, while positioning the cm elements, we should take into account that only the heelstrike zone must be considered and a triangle must be identified by placing its vertices in the most lateral point, in the most medial point and in the rearmost point, which must be considered as x. the bisector of the angle whose vertex is x must be considered as lax. the length of the major axis of the emor can be determined by using table 1 as in the case a. also the tripartite schemes used by wilkinson et al. (1995) and by mccrory et al. (1997) can provide great help in deterfig. 3 samples of footprints related to case b. 108 tab. 1 reference lenght and width of the fossil human foot for the definition of the longitudinal axis in the combined method (cm). � �� � � the "combined method" to validate human footprints mining the length of the major axis of the emor. then the rewil might be positioned taking into account the values in table 1. such dimensional values, refer to hominids of which at least one fossil footprint has been discovered, measured and verified as actual. of course, each choice must be made strictly taking into account the chronological age of the potentially trampled surface. for a wider dimensional range of the foot of contemporary homo sapiens, the huge study by howard v. meredith (1944) can be referred to. it must be taken into account that in the case b the degree of approximation of cm is wider. case c (at least one toeprint is visible but the proximal margin of the footprint is not preserved) (fig. 4) this third case is substantially similar to the second one since the preserved parts are only inverted, but the previously described procedure can be applied only if at least one of the preserved toe prints is the hallux. in such a fortunate case, it is sufficient to invert the procedure of case b by starting from the tip of the hallux to create all the other geometric elements. on the contrary, if only the 2nd and/or the 3rd toe prints are preserved, it is much more difficult to identify all the other elements of the cm since we are in a situation of extreme approximation. in fact, the details of the impression preserved are so few that it is really difficult to find reliable information about both its ichnological reality and/or about its precise location in a gait pattern. in what remains of the imprint only a square-ruler can be applied whose longer side is tangential to the most lateral contour of the toe 2nd or to the most medial contour of the toe 3rd, the shorter and horizontal side of the same square ruler being tangential to the most distal limits of the toe prints. although with a wide margin of approximation, the vertical side of the square ruler can be considered as lax, so that it is possible to proceed to the application of the values in the table 1 and to go on to identify the x and the bl. when only a few anatomical details are visible, the tripartite scheme used by wilkinson et al. (1995) and by mccrory et al. (1997) can be a great help in determining the length of the major axis of the emor. measurement and analysis by the cm isolated footprints or potential footprint in which even less details are preserved should not be attempted. case d (both proximal and distal margins of the contour are not visible; only a few traces of the contour are preserved) (fig. 5) this is the most complicated case to be analysed as the amount of available detail is poor. as a consequence it is also the case in which the obtained data are mostly approximate. however the main purpose of cm is to make emor most widely applicable and even in this situation it does not seem substantially altered, but let us see how to proceed. in the footprint area we must consider as am and tm, respectively, the most medial edges of the preserved contour of the ball-zone and the heel-zone. similarly, we must consider as al and tl, respectively, the most lateral edges of the preserved contour of the ball-zone and of the heel-zone. 109 fig. 4 samples of footprints related to case c. � �� � � this makes us able to draw a convex hull of the potential footprint and to determine its lax as already carried out in case a. both of them, though approximate, do not significantly alter the framework of the depressions inside the footprint area. so, it is sufficient to draw the perpendicular to lax passing through the rearmost point of the heel-zone to identify point x. now we can use table 1 to determine the length of the major axis of the emor and, consequently, all the other necessary details of the cm scheme. as in preceding cases an additional aid can be given by the tripartite scheme used by wilkinson et al. (1995) and by mccrory et al. (1997). case e (no part of the contour is preserved; only a displacement rim is visible) in this last case we must be fully aware that we are working on the extreme border of reality and that the only instance in which we analyze the potential footprint is in the presence of a displacement rim in its total structure. such a rim, as well-known, can be created only by trampling a surface that has yet to be solidified. nevertheless we must be extremely prudent while analyzing details taking into account that the displacement rim could mean only that the same hollow is a true imprint and not also that it is an actual human footprint. of course, if the footprint-like depression is coordi�nated into a gait pattern the possibility of it being an actual footprint increases significantly. to apply the cm we inscribe the general hollow marked by the edge of the expulsion rim in the most narrow rectangle that can contain the entire depressed area. so the middle longitudinal line of the rectangle can be considered as the lax and its length matches the major axis of the emor. of course, the bl is the base of the same rectangle. as above, here too we can apply the tripartite scheme used by wilkinson et al. (1995) and by mccrory et al. (1997) to determine the length of the major axis of the emor. on the basis of the described geometric constructions 5 basic landmarks should be identified: landmark 1: the point of coincidence on the baseline (bl), between the rearmost point of the heel and the lowest point of the major axis of the emor. landmark 2: the highest point of the major axis of the emor located on the parallel to the base-line tangent to the distal point of the most protruding toe print. landmark 3: the point of intersection between the parallel to the base-line passing through the midpoint of lax and the lateral contour of the footprint. landmark 4: the point of intersection between the parallel to the base-line passing through the midpoint of lax and the medial contour of the footprint. landmark 5: the point of maximum pressure inside the footprint area. 3. in-field experiments although the cm is substantially a winning combination of methods (wilkinson et al., 1995; kennedy et al., 2003; berge et al., 2006; morse et al., 2010), which have been widely and successfully tested, we think that some supplementary specific experimentations in the field of the cm can be useful to verify its reliability and also to show its limitations. for this purpose, we selected two trackmakers (an adult male and an adult female) with known anthropometric characteristics and diseases and we let them walk along different substrates without conditioning their normal walking. the male trackmaker walked on a sandy ground, while the female walked on uneven and chaotic matter made up of mud and gravel, and on another surface consisting of a cement mixture. then we surveyed the footprints they left and we analyzed them by cm. in all three cases the depth areas inside the footprints were found in the expected sectors of the emor. moreover, in the case of the female trackmaker, the analysis of the contour lines of the footprints allowed us to detect and to highlight the disease for hallux valgus she had already declared. all examined footprints proved that cm always works but also pointed out that the variability of the substrate can heavily affect the dimensional range of the same footprints. this suggests extreme caution while making any estimation about the body of the trackmaker starting from his fossilized footprints. finally, we successfully tested the combined method on an actual human fossil footprint, which has 110 fig. 5 samples of footprints related to case d. panarello a., mietto p. � �� � � � been dated around 350 ka b. p. (mietto et al., 2003; avanzini et al., 2008). the photogrammetric measurements were taken using an slr camera canon eos 550d equipped with lens canon ef-s 18-200 mm and a compact camera canon powershot g9. developments, measurements and calculations of three-dimensional models, as well as maps derived therefrom, were made using the software agisoftphotoscanprotm (ver. 0.9.0 build 1586) and kitwareparaviewtm (ver. 3. 98.1.64) and the details of each photogrammetric model are shown in table 2. we think that the field experimentations we present here are good examples to show that cm is effectively able to reveal if a hollow on the ground can be an actual footprint or not. furthermore, the cm proved effective in any weathers and is capable of revealing some deformations of the foot if present. sea sand the experiment was carried out in a place of the tyrrhenian shore at scauri, a small city located in central italy (province of latina; n41° 15.010'e13°42,941') (fig. 6). the trackmaker (b.f., male, aged 54, 1,65 m tall, and 66,5 kg weight) said he had suffered some years ago from a double fracture of the left anklebone with detachment of the cartilaginous joints. during the experimentation, he walked barefoot for a distance of 8 meters. the footprints he left were 14, of which 7 relate to the right foot and 7 to the left foot. the data concerning the gait, however was measured only in the central part of the trackway and refers to the tracks from 5 (left) to 8 (right) (fig. 7, fig. 8), in order to avoid any additional variables due to acceleration or deceleration. the average measured stride is approximately m. 1,175. the average length of the measured foot is m. 0,27. the average width of the track is about 38 cm. the estimated stature measured starting from footprints’ dimensions almost perfectly matches the effective one by applying a ratio of 16,4%, which is in perfect harmony with an extremely pliable substrate that guarantees that the footprint is dilated both in length and in width compared to the actual size of the foot. sea sand, which is composed of very fine grains, has proved to the most receptive substrate, capable of preserving a detailed impression giving exhaustive anatomical and biomechanical data. the details are more evident in 111 tab. 2 parameters of the photogrammetric models. fig. 6 scauri beach (central italy) location of the experiment on sea-sand (trackmaker: b.f., male). � the "combined method" to validate human footprints � �� � � � 112 fig. 7 experiment on sea-sand: the analysed footprints among those left by the male trackmaker b. f. (a: zenithal photography; b: contour lines (1mm); c: depth map). panarello a., mietto p. � �� � � this creates a very pronounced discontinuity between the distal part of the forefoot (which assumes precisely the rounded shape of a pillow) and the proximal part the toe depressions, which are aligned with the hallux depression along an anteromedially oriented direction. finally, the foot angle, i.e. the angle measured between the tread and the axis line of progression, shows that the places where marine sand also has slightly slimy component. it is also very interesting to note that a large amount of sand is pushed up corresponding to the medial longitudinal arch area and this makes evident that body balance while walking is searched and found in the lateral area of the foot. the backwards movement of the toes is also evident as they try to grip the ground and 113 fig. 8 experiment on sea-sand: details of the four considered footprints. fig. 9 experiment on sea-sand: the combined method applied on the considered stretch of trackway. the "combined method" to validate human footprints � �� � � left foot (18°) is more everted than the right (16°), which could be reminiscent of the trauma fracture in his left foot, which, although it has perfectly healed, may have left a trace in the gait pattern. finally, in all of the footprints, which are magnificently preserved, all the characteristics of the human foot are fully recognizable, i.e. 1) a wide and well-rounded heel pad; 2) a wellshaped, narrow and raised medial arch; 3) a welldefined forefoot with a well characterized ball; 4) the presence of occasional ridges proximal to the positions of the heads of the 1st and the 2nd metatarsal bones; 5) maximum extension in the distal zone of the ball pad which is rightly located in correspondence of the position of the 2nd toe; 6) well defined and separated impressions of pad and tip of the hallux; 7) well defined impressions of lateral toes (meldrum et al., 2011). specifically referring to the cm application, all the landmarks are in their correct position (fig. 9). cement mixture the experimentation was carried out during the casting of a pavement, on a specially leveled surface (fig. 10). the substrate was composed of a mix with a very high percentage of cement, enriched with potassium and a plentiful quantity of river gravel. the experiment was carried out in the rain so the degree of wetting was very high and gave the consistency of an almost muddy matter with continuous collapse of the sidewalls of the footprints after a lifting of the foot. the trackmaker was a female (s.m.z., 45 years old, 1,52 m tall and 55 kg weight) who is suffering from hallux valgus on both feet. during the trial, she walked barefoot along a distance of 10 meters on an almost planar and extremely yieldable ground. she left a total of 17 footprints (8 relate to her right foot and 9 relate to her left foot). however, to avoid any bias from braked or accelerated gait, all data was recorded only in the central part of the trackway and refers to the footprints from 6 (right) to 9 (left) (fig. 11). the average stride measured is approximately m. 1,10. the measured average length of the foot is about m. 0,20. the estimated stature starting from the footprints’ length almost perfectly matches the effective one if we apply a 13,2% ratio. this is easily explainable if we consider that the soft matter of the substrate always collapses inside of the impression after the foot pressure and its consequent lift which causes extremely irregular contours and frames which, in any case, are less long and/ or less wide than the real ones. the average angle of the left foot, with respect to the line of progression, is equal to 6,5° while the average angle of the right foot is equal to 7,5°. the average measured width of the track is about 25 cm. it is worth nothing that only footprint n. 6 and n. 7 are completely and objectively measurable. the footprint n. 6 (right foot) (fig. 12), although narrow and elongated, preserves an evident medial concavity, which has its own center in the central third of the total length of the footprint. furthermore, if we apply the emor on it (fig. 13), we can notice that the landmark on the key of the vault of the medial longitudinal arch fully respects the criterion of berge et al. (2006) as it falls in a higher position than the forefoot and the rear foot impressions. finally although partly covered by the collapse of the medial wall of the cavity it is clearly visible, within its contour, the protrusion of the 1st metatarsal head. also on the lateral side, the movement towards the intermodal soft wall has reduced the width of the midfoot, but has not completely erased the anatomic details of the human foot. the forefoot, as was logical to be expected, is evident, as well as the most proximal part of the depression of the hallux. another important specimen is the footprint n. 7 (left foot) (fig. 12), which is the clearest and most readable one. it has an extended displacement rim, which is more evident on the lateral margin. here the sidewalls 114 fig. 10 location of the experiment on cement mixture (trackmaker: s.m.z., female). � � �� � � � 115 fig. 11 experiment on cement mixture: the analysed footprints among those left by the female trackmaker s.m.z. (a: zenithal photography; b: contour lines (1mm); c: dept-map). � �� � � fig. 12 experiment on cement mixture: details of the two best surveyable footprints among the four considered ones. � � 116 � fig. 13 experiment on cement mixture: the combined method applied on the considered stretch of trackway. panarello a., mietto p. � �� � � had only minor failure meaning every detail of the shape of the foot is well recognizable. the footprint inclusion within the emor diagram has further highlighted the correct anatomical position of maximum pressure areas and so the impressions of the heel and the forefoot with the hallux and 2nd toe are very evident. medially, likewise the protrusion of the head of the 1st metatarsal bone is very evident, confirming disease of hallux valgus as declared by the experimental trackmaker before starting her walking. within the footprints n. 8 (right foot) and n. 9 (left foot), the details are less clear so that the emor is not easily fixable. however, in both cases the areas of maximum pressure are evident inside the footprint and are located in the third medial distal part. such evidence is fully compatible with those of the same kind which are better preserved in the other footprints (fig. 13). finally, the frameworking within an ichnological pattern respecting human gait-standard is clearly constructible as one could expect since the trackmaker is definitely human. mud and gravel the experiment was carried out on a small area created by the outflow of precipitated waters during heavy and prolonged rainfall. the transported debris are laid on a thick muddy bottom, creating a composite matter, which is muddy and extremely plastic in depth and has an uneven, porous and grainy surface. the emplaced layer is about 9 cm thick, while its grainy surface is only a few millimeters thick (fig. 14). we chose this kind of deposit to analyze the response of such a chaotic matter to foot pressure during walking. the trackmaker is the same used for the experiment on cement mixture (smz, female, 45 years old, 1,52 m tall, 55 kg weight, with a declared disease from hallux valgus on both feet) and she walked barefoot along a stretch of about 3 meters, leaving 7 footprints (4 relate to the right foot and 3 relate to the left foot). as in previous cases, to minimize the distortion due to an eventual mental conditioning for the initial acceleration and the final braking, only four footprints in succession have been considered, that is the most central ones, from the footprint n. 3 (right) to the footprint n. 6 (left) (fig. 15). the average angle of the left foot, compared to the line of progression, ranges from -2° to -5° revealing a tendency to introflex the foot overcoming the line of progression, perhaps forcing the pronation in the search for balance during walking on such unstable ground. on the contrary, the average angle of the right foot is quite constantly 4°. the average width of the tracks is about 18 cm. the average measured stride is approximately m. 0,73. the average length of the measured foot is about m. 0,21. the estimated stature starting from footprints length almost perfectly matches the actual one by applying a 13,8% ratio. also in this case, the extremely yieldable substrate influences the actual size of the prints, but without erasing the anatomical features of the foot. the footprint n. 3 (right foot) (fig. 16) is very light as it was left in an small area where the mud layer was thinner. although the displacement rim is barely perceptible in the lateral side area, the hollow of the forefoot is perfectly recognizable and clearly shows the declared disease from hallux valgus on both feet. the cavity of the hallux is also easily recognizable, especially in its proximal part. the footprint n. 4 (left foot) (fig. 16) is recognizable in all its parts and preserves the signs of high pressure in the forefoot area, especially in correspondence with the head of the 1st metatarsal such highlighting the mentioned disease from hallux valgus. in addition within the footprint n. 4 area a strange accentuation of depth in the medial side of the ball is also evident. this is due to the major pliability of the ground at that point that was instinctively compensated by the trackmaker with a more pronounced anteromedial pronation. footprints n. 5 (right foot) and n. 6 (left foot) (fig. 16) are those which preserve the clearest anatomic details of the human foot and in both of them, the depressions of the heel, medial longitudinal arch, forefoot, toe depressions and big toes were perfectly identifiable. the footprints n. 3 and n. 5 are slightly introflexed with respect to line of progression, but they do not show a significant depth in their medial distal area. this is due to greater compactness of the ground at that point and also to a more secure and steady pace. finally, both footprints show evidence of hallux valgus, represented by a pronounced protrusion medially oriented of the ball in correspondence of the head of the first metatarsal bones. also on this very heterogeneous ground all fixed 117 fig. 14 detail photo of the matter used for the experiment on mud and gravel (trackmaker: s.m.z., female). � the "combined method" to validate human footprints � �� � � � 118 fig. 15 experiment on mud and gravel: the analysed footprints among those left by the female trackmaker s.m.z. (a: zenithal photography; b: contour lines (1mm); c: dept-map). panarello a., mietto p. � �� � � landmarks fall in the correct anatomic areas within the fixed emor (fig. 17) finally, we must observe that the length of the step and of the stride seem to be influenced more by a sort of consciousness of the brevity of the walkable route than by the instability of the ground. actual human fossil footprint we also applied the combined method on one of the so-called “ciampate del diavolo” (“devil’s trails”), i.e. on one of the well-known actual middle-pleistocene human footprints found on the north-eastern slope of the roccamonfina volcano (central italy) (mietto et al., 2003; avanzini et al., 2008). 119 fig. 16 experiment on mud and gravel: details of the four considered footprints. fig. 17 experiment on mud and gravel: the combined method applied on the considered stretch of trackway. the "combined method" to validate human footprints � � �� � � we chose for this purpose the footprint a25, which is one of the best preserved and we were soon able to observe that also in this case the cm works very well. in fact, although the footprint is located on a steep slope, all the cm landmarks fall in their correct positions so confirming what we already knew, i.e. that the considered footprint was left on a soft slope by a right foot of an our ancestor who lived around 350 ka b.p. (scaillet et al., 2008; santello, 2010). within the footprint's contour and using the cm scheme the imprints of the heelstrike zone are clearly visible, like those of the medial longitudinal arch, forefoot and hallux. all of them match perfectly with the anatomic landmarks where one would expect to find them (fig. 18). 4. discussion and conclusions the schemes and landmarks of the combined method allow us to scientifically evaluate the precise positions of the most depressed areas within the emor area according to morse et al. 's method (morse et al., 2010) and according to the anatomical features of the human foot. it is widely known that the depressions on the bottom of a human footprint can perfectly reproduce the movements of the lower limbs and mainly of the feet during a gait cycle, therefore we should expect to localize the deepest area of the foot in the geometrical zones which the body weight passes through in order to able to say that a depression is an actual footprint or not. specifically, the deepest depressions must be located at least in the heel-strike zone, in the zone of the heads of the 1st-2nd metatarsal bones and in the hallux zone (day & wickens, 1980; schmid, 2004; meldrum & hilton, 2004; klenerman & wood, 2006; raichlen et al., 2010; morse et al., 2010; bennett & morse, 2014; meldrum et al., 2011; dingwall et al., 2013). so it is very important that after the application of the cm at least the landmarks 1 and 5 do not fall, respectively, outside quarters 2-3 (both of the feet) and outside quarter 1 (left foot)/ quarter 4 (right foot) of the emor. similarly, landmark 4, which corresponds to the vault of the plantar arch, has to be always at a higher level than those of all other landmarks as well pointed out by berge et al. (2006). if some disease or malformation of trackmaker's foot is supposed, it must be present in more than one imprint of the same foot before it can be considered as authentic (morse, 2013; bennett & morse, 2014; panarello, 2016 and quoted bibliography). finally, we think using the combined method, which is a combination of other already known and welltested methods, is a significant breakthrough and certainly be considered as an important improvement. it is 120 fig. 18 roccamonfina footprint "devil's trails" a25 (a: zenithal photography; b: solid surface; c: contour lines (1 mm); d: depth map; e: depth map with emor applied). panarello a., mietto p. � �� � � clearly evident, its easiness of application and its capacity to be applied practically to each hollow or depression on the ground, even to those in which no anatomical detail is visible. as it is based on the depressions created by the displacement substrate as the human foot ambulates on a soft ground, it is closely linked to the anatomy of the human foot. the cm is free from strictly located positions of the anatomic features of the foot within the bottom of the footprint and is more closely linked to the motion vector of center of mass and of body weight during the gait cycle. perhaps the cm alone is not able to say if a depression on the ground is an actual footprint or not, but it is certainly able to say if the depression is not an actual footprint and/or if it is at least compatible with a human footprint. the cm is much more accurate and useful if applied to successions of potential footprints together with other methods for the analysis of the human gait (as, for example, that of wilkinson et al., 1995). moreover, the cm becomes precious if associated with other stratigraphical, palaeontological, chemical, archeological and anthropological methods for evaluating the potentially ichnological sites and it also lends itself to pointing out some recent natural and anthropic contaminations and/ or alterations of the most ancient traces. acknowledgements we are very grateful to mr. b. f. and mrs. s.m.z. for having made possible the experiment on field with their great patience and willingness. we also thank mr. pasquale de fusco and mr. angelo salvucci for their precious help during the experiment on cement mixture. we are also very thankful to maria rita palombo, andrea sposato and the anonymous reviewer, for their precious comments and suggestions that increased the quality of the manuscript. finally, we would like to thank ms maria palumbo and ms teresa gray for their linguistic check. references avanzini m., mietto p., panarello a., de angelis m., rolandi g. (2008) the devil’s trails: middle pleistocene human footprints preserved in a volcanoclastic deposit of southern italy. ichnos, 15, 179-189. bennett m.r., gonzalez s., huddart d., kirby j., toole e. (2010) probable neolithic footprints preserved in inter-tidal peat at kenfig, south wales (uk). proceedings of the geologists' association, 121 (1), 66-76. bennett m.r., harris j.w.k., richmond b.g., braun d.r., mbua e., kiura p., olago d., kibunjia m., omuombo c., behrensmeyer a.k., huddart d., gonzalez s. (2009) early hominin foot morphology based on 1,5-million-year-old footprints from ileret, kenya. science, 323, 1197-1201 + supporting materials (http://www.sciencemag.org/content/ suppl/2009/02/25/323.5918.1197.dc1). bennett m.r., morse s.a (2014) human footprints: fossilised locomotion? springer, cham heidelberg new york dordrecht london, pp. 216. berge c., penin x., pellé é. (2006) new interpretation of laetoli footprints using an experimental approach and procrustes analysis: preliminary results. comptes rendus palevol, 5, 561-569. bridgland d.r., antoine p., limondin-lozouet n., santisteban j.i., westaway r., white m.j. (2006) the palaeolithic occupation of europe as revealed by evidence from the rivers: data from igcp 449. journal of quaternary science, 21, 437-455. bromley r.g., milàn j., uchman a., steen hansen k. (2009) rheotactic macaronichnus, and human and cattle trackways in holocene beachrock, greece: reconstruction of paleoshoreline orientation. ichnos, 16, 103-117. d’août k., aerts p. (2008) the evolutionary history of the human foot. in: d’août k., lescrenier k., van gheluwe b., de clercq d. (eds.), advances in plantar pressure measurements in clinical and scientific research. shaker publishing b.v., maastricht, 44-68. day m.h., wickens e.h. (1980) laetoli pliocene hominid footprints and bipedalism. nature, 286, 385387. de lumley m.a., lamy p., mafart b. (2011) une empreinte de pied humain acheuléen dans la dune littorale du site de terra amata. ensemble stratigraphique c1b. in: de lumley h. (ed.), terra amata: nice, alpes-maritimes, france, vol. 2: palynologie, anthracologie, faunes, mollusques, écologie et biogéomorphologie, paléoanthropologie, empreinte de pied humain, coprolithes, cnrs, paris, 483-507. dingwall h.l., hatala k.g., wunderlich r.e., richmond b.g. (2013) hominin stature, body mass, and walking speed estimates based on 1.5 million-year -old fossil footprints at ileret, kenya. journal of human evolution, 64, 556-568. fluck h.l. (2011) non-biface assemblages in middle pleistocene western europe. a comparative study. phd thesis, university of southampton, faculty of law, art and social sciences, school of humanities, pp. 342. garcia m.a. (2005) ichnologie générale de la grotte chauvet. bulletin de la société préhistorique française, 102 (1), 103-108. gonzález s., huddart d., bennett m.r., gonzálezhuesca a. (2006a) human footprints in central mexico older than 40, 000 years. quaternary science reviews, 25, 201-222. gonzalez s., huddart d., bennett m. (2006b) valsequillo pleistocene archaeology and dating: ongoing controversy in central mexico. world archaeology, 38 (4), 611-627. goudet-ducellier m. (1987) terra amata. un campement de chasseurs prehistoriques a nice il y a 400.000 ans. musée de terra amata, ville de nice, pp. 127. hadingham e. (1985) the hunters and the heavens. in: hadingham e., early man and the cosmos, university of oklahoma press, 84-85. houck k.j., lockley m.g., avanzini m. (2009) a survey 121 the "combined method" to validate human footprints � �� � � of tetrapod tracksites preserved in pyroclastic sediments, with special reference to footprints of hominids, other mammals and birds. ichnos, 16, 76-97. inah (2011) descubren huellas humanas de 25, 000 años de antigüedad. http://www.inah.gob.mx/ boletines/16-antropologia/5259-descubren-hue kennedy r.b., pressman s.i., chen s., petersen p.h., pressman a.e. (2003) statistical analysis of barefoot impressions. journal of forensic sciences, 48 (1), 55-63. kim k.s., kim j.y., kim s.h., lee c.z.,, lim j.d. (2009) preliminary report on hominid and other vertebrate footprints from the late quaternary strata of jeju island, korea. ichnos, 16, 1-11. klenerman l., wood b. (2006) the human foot. a companion to clinical studies. springer, london, pp. 182. kretzoi m., dobosi v.t. (eds.) (1990) vértessz�l�s: site, man and culture, budapest. akademiai kiado, pp. 555. lockley m., roberts g. (2004) in the footprints of our ancestors: a brief overview of the hominid track record. in: kim j.y., kim k.s., park s.i., shin m.k. (eds.), international symposium on the quaternary footprints and hominids and other vertebrates. proceedings of international symposium, poonglim resort, seoguipo city and footprint site of namjeju, jeju island, korea, october 9thoctober 10th, 27-43. lockley m., roberts g., kim j.y. (2008) in the footprints of our ancestors: an overview of the hominid track record. ichnos, 15, 106-125. lockley m.g., rodríguez-de la rosa r.a. (2009) preservation of human tracks in arid environments. ichnos, 16, 98-102. lockley m.g., vasquez r.g., espinoza e., lucas s.g. (2009) america’s most famous human footprints: history, context and first description of mid-holocene tracks from the shores of lake managua, nicaragua. ichnos, 16, 55-69. marquer p. (1960) note sur deux empreintes de pieds humains trouvée sdans la république centreafricaine. journal de la société des africanistes, 30 (1), 7-14. mccrory j.l., young m.j., boulton a.j.m., cavanagh p.r. (1997) arch index as a predictor of arch height. the foot, 7, 79-81. meldrum d.j., hilton c.e. (eds.) (2004) from biped to strider. the emergence of modern human walking, running, and resource transport. kluwer academic/plenum publishers, new york, boston, dordrecht, london, moscow, pp. 213. meldrum d.j., lockley m.g., lucas s.g., musiba c. (2011) ichnotaxonomy of the laetoli trackways: the earliest hominin footprints. journal of african earth sciences, 60 (1-2), 1-12. meredith h.v. (1944) human foot length from embryo to adult. human biology, 16 (4), 207-282. mietto p., avanzini m., rolandi g. (2003) human footprints in pleistocene volcanic ash. nature, 422, 133. milàn j., bromley r.g., titschack j. (2005) vertebrate footprints from a new aeolian outcrop from southern rhodes, greece. international symposium on dinosaurs and other vertebrates palaeoichnology, fumanya-st.cornelt (cercs, barcelona) october 48th 2005. morse s.a., bennett m.r., gonzalez s., huddart d. (2010) techniques for verifying human footprints: reappraisal of pre-clovis footprints in central mexico. quaternary science reviews, 29, 2571-2578. morse s.a. (2010) footprint verification: a new method and case study. a thesis submitted to the graduate school-new brunswick rutgers, the state university of new jersey in partial fulfillment of the requirements for the degree of master of arts graduate program in anthropology written under the direction of dr. j.w.k. harris, pp. viii+95. panarello a. (2016) elementi di paleoicnologia degli ominidi, armando caramanica editore, marina di minturno, 228 p. panarello a., santello l., belvedere m., mietto p. (2017) (in press) is it human? discriminating between real tracks and track-like structures. ichnos, 110. doi.org/10.1080/10420940.2017.1337010 raichlen d.a., gordon a.d., harcourt-smith w.e.h., foster a.d., haas w.r. jr. (2010) laetoli footprints preserve earliest direct evidence of humanlike bipedal biomechanics. plos one, 5 (3), e9769, 1-6. robbins l.m. (1987) hominid footprints from site g. in: leakey m.d., and harris j.m. (eds), laetoli. a pliocene site in northern tanzania. clarendon press, oxford, 497-502. rodríguez asensio j.a., noval fonseca m.a. (2012) cuevatempranas (posada, llanes, asturias). in: arias cabal p., corchón rodríguez m.s., menéndez fernández m., rodríguez asensio j.a. (eds.), el paleolítico superior cantábrico, actas de la primeras mesa rotonda, san román de candamo (asturias), 26-28 de abril de 2007. publican, ediciones de la universidad de cantabria, santander, 255-264. rodríguez-de la rosa r.a., aguillón-martínez m.c., lópez-espinoza j., eberth d.a. (2004) the fossil record of vertebrate tracks in mexico. ichnos, 11 (1-2), 27-37. scaillet s., vita-scaillet g., guillou h. (2008) oldest human footprints dated by ar/ar. earth and planetary science letters, 275, 320-325. santello l. (2010) analysis of a trampled formation: the brown leucitic tuff (roccamonfina volcano, southern italy). phd thesis in "scienze della terra", università degli studi di padova, dipartimento di geoscienze, tutor: paolo mietto, cotutor: hans-ulrich schmincke. http://paduaresearch.cab.unipd.it/2566/1/phd_thesis_lisa_santello.pdf schmid p. (2004) functional interpretation of the laetoli footprints. in: meldrum d.j., hilton c.e. (eds.) (2004) from biped to strider. the emergence of modern human walking, running, and resource transport. kluwer academic/plenum publishers, new york, boston, dordrecht, london, moscow, 122 panarello a., mietto p. � �� � � 49-62. schmincke h.u., rausch j., kutterolf s., freundt a. (2010) walking through volcanic mud: the 2, 100 year -old acahualinca footprints (nicaragua) ii: the acahualinca people, environmental conditions and motivation. international journal of earth sciences, 99 (suppl. 1), 279-292. tuttle r., webb d., weidl e., baksh m. (1990). further progress on the laetoli trails. journal of archaeological science, 17, 347-362. tuttle r.h. (1987) kinesiological inferences and evolutionary implications from laetoli bipedal trails g-1, g-2/3, and a. in leakey m.d., and harris j.m. (eds.), laetoli. a pliocene site in northern tanzania. clarendon press, oxford, 503-523. visy z., nagy m., kiss z.b. (eds.) (2003) hungarian archaeology at the turn of the millennium. ministry of national cultural heritage-teleki lászló foundation, budapest, pp. 496. wilkinson m.j., menz h.b. (1997) measurement of gait parameters from footprints: a reliability study. the foot, 7, 19-23. wilkinson m.j., menz h.b., raspovic a. (1995) the measurement of gait parameters from footprints. the foot, 5, 84-90. 123 ms. received: november 28, 2016 final text received: june 13, 2017 the "combined method" to validate human footprints � �� � � � 124 sess 1_160211.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 the impact of sea level changes on an urbanized area: the case of the city of bari (apulia) rossella pagliarulo1 & fabrizio antonioli 2 1 cnristituto di ricerca per la protezione idrogeologica. bari 2 enea, casaccia. roma corresponding author: r. pagliarulo <r.pagliarulo@ba.irpi.cnr.it> abstract: pagliarulo r. & antonioli f. the impact of sea level changes on an urbanized area: the case of the city of bari (apulia). (it issn 0394-3356, 2011) this paper considers the different depths of the ancient floor levels in the crypt of st. nicholas basilica (bari), built in 1087 ad along the sea, as markers and compares them to eustatic sea level curve for the adriatic coastline reconstructed on the basis of the lambeck’s predictive model for the late pleistocene and holocene changes in local relative sea level. (lambeck et al.,2011). the palaeo sea levels have been obtained measuring: 1) the pavement levels in the crypt; 2) the groundwater table at the time of the construction of the basilica and in 1956. the results give an interesting contribution to calibrate the predicted sea level curve for the last 1000 year. riassunto: pagliarulo r. & antonioli f. l’impatto delle variazioni del livello mare su un’area urbanizzata: il caso della città di bari (puglia). (it issn 0394-3356, 2011) questo lavoro prende in considerazioni diversi livelli di calpestio della cripta della basilica di san nicola a bari, costruita sul mare nel 1087 e li confronta con la locale curva di riferimento di risalita del modello di lambeck et al., (2011). i paleo livelli del mare sono stati ricavati da misure sulla superficie piezometrica della falda acquifera sia al tempo della costruzione della basilica, sia successivamente. i risultati forniscono interessanti spunti di confronto per la calibrazione della curva negli ultimi 1000 anni. key words: relative sea level curve, adriatic sea, watertable, seawater intrusion parole chiave: curva di risalita del mare, mare adriatico, falda, intrusione marina lately, published and new data are available in defining sea-level change in many location all along the italian coastline. (antonioli et al., 2009; lambeck et al., 2004; 2011). the database provides predicted sea level curves since the last glacial maximum. the curves are reconstructed on the basis of geomorphological markers, coastal archaeological data and sedimentary core analysis. this paper is a contribution to the use of a measurement methodology, to calibrate and adjust the predicted values of sea level rise. archeological data coming from past floor levels of the crypt of st. nicholas basilica in bari are used in comparing these depths to the predicted sea level curve for the last 1000 yr. the basilica, built between 1087 and 1197, safeguards the saint’s relics and stands imposing in the old town of bari overlooking the adriatic sea. (fig.1). the crypt was originary a hypogean. the old town of bari is located on a little peninsula protruding to the sea. from the geological point of view it is founded on limestones of the apulian carbonatic plate. in particular, the formation of “calcari di bari” represents the bedrock for the whole area and consists of a sequence of grey whitish limestones, dolomitic limestones and dolomites in strata whose thickness ranges from about some decimeters to a few meters. the age is referable to upper albian-early cenomanian. eustatic sea level change occurred since middle pleistocene characterized the coast with the deposition of marine terraces. (pieri et al., 2009). they are arranged in several orders, the lower ones outcrop on the western and eastern part of the town, partly deleted by urbanization. they consist in sand dune bodies, actually at a height of 4-5 m a.m.s.l., overlaying both the calcareous sandstones of upper pliocenelower pleistocene and the mesozoic limestones. these deposits consist of porous yellowish calcarenites with clear oblique lamination. the fossil content is given by gasteropoda and helix. (zezza, 1971). the age of the deposits can be referred to upper pleistocene. although they do not include any special indicator it is possible to refer these deposits to a generic thyrrenian. (pieri, 1975). for this reason uplift rates are rather difficult to determine. the south adriatic coast was not colonized by warm fauna during the warmest sea highstands, but it is considered to be stable. the functional depths of the ancient floor levels in the crypt of st. nicholas basilica enables us to determine the mean sea level, since the year of the construction, quite precisely. by means of historical sources it has been possible to have information about the piezometric surface of the groundwater, its changes and the relationship with the current and past sea level. this coastal area is affected by sea water intrusion. (cotecchia, 1981). it is the induced flow of sea water into fresh 48 50 49 water aquifers. because fresh water is less dense than salt water it floats on top. the boundary between salt water and fresh water is not distinct, the salt water interface is brackish with salt water and fresh water mixing. the rise in sea level causes flooding of coastal land by sea water, either for a long or a short period. in addition sea level changes boost sea water intrusion into coastal aquifer that are hydraulically connected to the sea. for this reason since 1087 it was necessary to raise the floor of the crypt as it has been flooding by sea water intrusion. (cotecchia et al., 1983) (fig. 2). fig. 1, the old town of bari and the location of st. nicholas basilica il borgo antico di bari e la localizzazione della basilica di san nicola  fig. 2, sea level changes and the impact of sea water intrusion on the structures of the crypt. variazioni del livello mare e influenza dell’intrusione marina sulle strutture della cripta.  the impact of sea level changes on an urbanized ... 50 ms. received: testo ricevuto il references antonioli f., ferranti f., fontana a., amorosi a., bondesan c., braitenberg c., dutton a., fontolan g., furlani s., lambeck k., mastronuzzi g., monaco c., spada g. & stocchi p. (2009) – holocene relative sea-level changes and vertical movements along the italian and istrian coastlines. quaternary international, 206 boll. soc. geol. it., 109, pp.102-133. cotecchia v. (1981) – methodologies adopted and results achieved in the investigation of seawater intrusion into the aquifer of apulia. geol. jb. c29 hannover, pp.1 -68. cotecchia v., tadolini t. & tulipano l. (1983) – sea water intrusion in the planning of groundwater resources protection and utilization in the apulia region (southern italy). geologia applicata e idrogeologia, 18, (ii), 367382. lambeck k., antonioli f., purcell a., & silenzi s. (2004) sea-level change along the italian coast for the past 10,000 yr. quaternary science reviews 23, pp.1567-1598. lambeck k., antonioli f., anzidei m., ferranti l., leoni g., scicchitano g. & silenzi s. (2011) sea level change along the italian coast during the holocene and projections for the future. quaternary international, 1-8 pieri p. (1975) – geologia della città di bari. memorie soc. geol. it, 14, 379-407. pieri p., sabato l., spalluto l. & tropeano m. (2009) – carta geologica dell’area urbana di bari. progetto carg. convegno sigea “geologia urbana di bari ed area metropolitana”, bari, novembre 2009. zezza f. (1971) – significato geologico e caratteristiche sedimentologiche delle dune e dei depositi di spiaggia fossili fra bari e monopoli. geologia applicata e idrogeologia, vi, 1-15. r. pagliarulo & f. antonioli january 13, 2011 13 gennaio 2011 use of quaternary travertines of central-southern italy as archives of paleoclimate, paleohydrology and neotectonics adele bertini1, 2, angelo minissale2 & marianna ricci1 1dipartimento di scienze della terra via g. la pira 4, 50121 firenze, abertini@geo.unifi.it, mari12682@hotmail.com 2cnr istituto di geoscienze e georisorse via g. la pira 4, 50121 firenze minissa@igg.cnr.it abstract: a. bertini et al., use of quaternary travertines of central-southern italy as archives of paleoclimate, paleohydrology and neotectonics. (it issn 0394-3356, 2008). this paper reports how travertine of central-southern italy, formed in response to the extensive circulation of waters inside the regional aquifer hosted in the mesozoic carbonate sequences, can be used as a tool for paleoclimatic, neotectonic and paleohydrological investigations. co2-rich thermal springs, co2 vents and travertine are frequent occurrences of the peri-tyrrhenian sector of central-southern italy. in a crust affected by mantle magmas triggering fluids motion, among others co2 from several horizons at variable depth, the δ13c of co3-ions of dissolved travertine suggests the type of circulation and the prevalent co2 source involved. more negative values suggest “normal” topographically driven circulation in karstic circuits, where co2 derives from soil (bacteria); more positive values suggest the inflow into the karstic circuits of deep co2. such rising co2, together with other acidic gases (e.g. h2s) greatly enhances limestone dissolution. accordingly, the travertine formed at the surface (metheogene vs thermogene) reflects the type of “mother” co2 involved in the dissolution process. in this way, travertine can be used to trace the evolution of paleohydrothermal systems in areas where there are no thermal features at surface. in terms of tectonic tool, since active and fossil travertine in the apennines can be found at very different elevations, their formation age reflects the difference in elevation between the present and the past karstic circulation. being the apennines a young, very active orogen, the described methodology of using travertine as a benchmark for paleohydrology, suggests for a vertical isostatic rate of 0.7 mm/y. being very sensitive to environmental conditions, travertine can also be used as a tracer for paleoclimate. the parallel investigation on the stable isotopic composition (δ18o, δ13c) of the dissolved co3-ions, and palynological profiles in two pleistocene deposits of central italy (serre di rapolano and tivoli, the latter in progress), allowed to describe variations in the last ca 120 kyrs. the correspondence between observed environmental fluctuations in pollen and isotopes, as well as with other proxies in nearby terrestrial deposits, and with more global proxies (ice-core and foraminifera) seems possible and demonstrates that travertine can be used to investigate the paleoclimate of the late quaternary. this is in line with the observation that most of dated travertine in central italy cluster in interglacial periods. this coincidence seems reasonable: 1) because the deposition of travertine is depending upon rainfall amounts, and 2) because in glacial periods, the lower level of the oceans also lowers the base level of karstic circulation. riassunto: a. bertini et al., i travertini quaternari dell'italia centro-meridionale come archivio per studi paleoclimatici, paleoidrologici e sulla tettonica attiva. (it issn 0394-3356, 2008). la diffusa presenza nel settore peri-tirrenico dell'italia centro-meridionale di sorgenti termali, emissioni gassose a co2, nonché di numerosi depositi di travertino (fossili ed attuali) formatisi in seguito alla circolazione carsica in acquiferi regionali confinati nelle sequenze carbonatico-mesozoiche, offre la possibilità di indagare il possibile utilizzo dei travertini stessi per ricostruzioni paleoambientali, paleoclimatiche, paleoidrologiche e neotettoniche. in una crosta in cui magmi del mantello favoriscono la formazione secondaria di co2 metamorfica a vari livelli di profondità, che risalendo entra nell'acquifero carbonatico regionale, esiste uno stretto legame tra la composizione isotopica del carbonato dei travertini e la composizione isotopica della co2 disciolta nell'acqua da cui i travertini stessi precipitano. conseguentemente, il δ13c dei travertini suggerisce il tipo di circolazione e la sorgente prevalente della co2 che li ha generati. in particolare, valori negativi suggeriscono una circolazione di tipo carsico, superficiale, con co2 derivata dall'alterazione del materiale organico del suolo; valori più positivi, indicano invece la prevalenza di co2 più profonda, che, risalendo insieme ad altri gas acidi, eventualmente presenti (e.g. h2s), aumenta la dissoluzione dei carbonati. i depositi di travertino che si formano in superficie, riflettono il tipo di co2 “madre” che è coinvolta nei processi di dissoluzione (meteogenici o termogenici). i travertini possono quindi essere utilizzati per mettere in luce la presenza di antichi sistemi idrotermali anche laddove non si hanno più evidenze superficiali di questo tipo. in italia, muovendosi dal settore occidentale peri-tirrenico verso quello orientale adriatico, si osserva una chiara relazione spaziale tra differenti tipi di travertino. depositi termogenici (travertini s.s.), associati a sorgenti termali, sono diffusi nel versante tirrenico mentre depositi meteogenici (tufa), che si originano da acque di origine carsica a co2 prevalentemente biologica e/o atmosferica, sono frequenti nel settore adriatico. le indagini geologico-stratigrafiche effettuate in seguito al terremoto del 1997 che ha colpito l'area del colfiorito, hanno evidenziato la buona potenzialità dei travertini come strumento per indagini sulla tettonica attiva. e' risultata evidente una relazione diretta tra quota di affioramento ed età di formazione dei depositi; la differenza di età di formazione tra i depositi più orientali e quelli più occidentali, ha permesso di calcolare un tasso medio di sollevamento per questo settore della catena appenninica pari a 0.7 mm/anno. i travertini sono anche sensibili indicatori delle variazioni che si verificano al momento della loro deposizione e, al loro interno, possono conservare testimonianze utili (polline, foglie, gasteropodi, ecc.) per le ricostruzioni ecologiche e climatiche. indagini isotopiche (δ18o e δ13c) e palinologiche, ancora in corso, in due depositi pleistocenici dell'italia centrale (serre di rapolano e tivoli) hanno fornito prime utili indicazioni per gli ultimi 120.000 anni. la buona corrispondenza tra i cambiamenti climatico/ambientali registrati dal polline e le fluttuazioni degli isotopi stabili dell'ossigeno e del carbonio facilita le correlazioni con gli eventi climatici già noti a scala regionale e globale. la potenzialità dei travertini come strumento per le ricostruzioni paleoclimatiche è rafforzata anche dalla constatazione che la maggior parte di questi depositi si sono particolarmente sviluppati durante le fasi interglaciali. questa coincidenza sembra probabile: 1) in quanto la deposizione del travertino dipende dall'ammontare delle precipitazioni e 2) perché durante le fasi glaciali l'abbassamento del livello del mare è accompagnato anche dall'abbassamento del livello di base della circolazione carsica. keywords: quaternary travertine, stable isotope, palynology, co2, neotectonics, paleoclimate, central-southern italy. parole chiave: travertini quaternari, isotopi stabili, palinologia, co2, neotettonica, paleoclima, italia centro-meridionale. il quaternario italian journal of quaternary sciences 21(1b), 2008 99-112 100 a. bertini, a. minissale & m. ricci 1 introduction travertine may have been among the first chemically formed stones after the initial cooling phase of the earth and, among others, it could have represented a perfect environment for the development of the first living microbial on earth (farmer, 2000). furthermore, in the re-cycling process to the atmosphere of “non volcanic” co2 from the earth's interior, it also plays, especially along plate boundaries (ba r n e s et al., 1978), an important role in the global carbon cycle (berner et al., 1983). having so many different shapes, textures, structures and colours, travertine is also an attractive stone, and this, along with its relative ease of quarrying and cutting, is the reason for its present commercial fortune as decorative building material. together with other countr ies of the mediterranean region (i.e. greece and turkey), italy is extremely rich in travertine s.s. deposits. reasons for such abundance are the following: 1) the mediterranean is an active plate boundary, with enhanced fluid motion at shallow levels in the crust, triggered by mantle-originated magmas and related thermal anomalies; 2) the mediterranean region has thick mesozoic pelagic and/or platform limestone sequences (formed in the tethys ocean), often covered by thick impermeable flysch and syn-and-post-alpine clay-rich sedimentary sequences; 3) the mesozoic limestone sequences, especially when buried by impermeable flysches and post-alpine sequences, may undergo (near orogenic granites and/or mantle magmas intruded in the crust) strong metamorphism and decarbonation in presence of hot, silica-rich solutions (skarn). acidic magmatic and/or metamorphic fluids, rising from depth, spread into the regional aquifer hosted in the high-permeable mesozoic sequences, greatly enhancing the dissolution rate of the limestone. related aquifer waters, eventually emerging at the surface as co2-rich, caco3-oversaturated thermal springs (“soda springs”), quite often precipitate travertine at the edges of the limestone outcrops (mi n i s s a l e, 2004 and references therein). fig. 1 active-precipitating and fossil travertine deposits in central-southern italy (modified from minissale, 2004). i depositi di travertino attuali e fossili dell'italia centro-meridionale (modificata da minissale, 2004). the entire western peri-tyrrhenian coastal sector of central-southern italy is affected by such thermal spring emergences, some of which still precipitate abundant travertine (fig. 1), especially at the periphery of the active and quaternary volcanoes. on the other side, widespread metheogene travertine deposits (tufa) formed (and are still forming) at higher elevations in the nw-se trending inner central carbonate backbone of the apennine range. this type of travertine tends to be less compact and/or less diagenetically altered, with less pronounced stratification than travertine s . s. , reflecting a more turbulent regime of precipitating mother waters. the more metheogene character of such deposit, often directly precipitating from river falls, accounts for a different terminology, such as tufa (ford & pe d l e y, 1996). a recent paper (an d r e w s, 2006) reviewed the paleoclimatic significance of such deposits in central-northern europe for the last 13.000 ka. in the present study the authors try to parallel the paleoclimate significance of travertine s.s. deposits of central italy, with the one given by tufa, emphasizing also some genetic aspects, in terms of origin of co2 of mother solutions. furthermore, being active and fossil travertine and tufa deposits of central italy hosted in an extremely dynamic environment, their presence at different places, at different elevations, is tentatively related to the paleohydrology and the active tectonics of the last 500 ka. 2 travertine as a prospecting tool for the genesis of “mother” co2 an active geothermal system, such as the larderello geothermal field in tuscany (fig. 1), naturally 101use of quaternary travertines ... generates, and moves to the surface, abundant deep, hot hydrothermal fluids. by limiting our attention simply on co2, the larderello system transfers to the atmosphere, daily, about 3.000 tons of co2 (minissale et al., 2005). if this is the rate that can be directly measured (or estimated) in the natural steam vents and boiling pools (“lagoni”) located on top of the geothermal system, much more co2 probably escapes, laterally, from the cooler boundary condensation zones of the system (ce c c a r e l l i et al., 1987). such co2 e v e n t u a l l y enters the regional karstic hydrologic circuit(s) inside the regional carbonate reservoir, which at larderello bounds extensively the geothermal system in its southsouth eastern edges (fig. 2, redrawn after mi n i s s a l e, 1991). on the other side, the mesozoic carbonate sequences, which crop out as the main backbone of italy, are huge collectors for meteoric waters topographically flowing, both westward and eastward, towards the tyrrhenian sea and the adriatic sea, respectively. such descending waters, especially when intersecting the ascending geothermal co2 (and h2s ) , dissolve the limestone in karstic circuits, greatly increasing the ca-hco3 concentration of solutions, when compared if co2 derived only by organic, soil-derived co2 formed in the absorption areas. this double circulation pattern of co2 of different origin has been well documented in a large sector of central italy, across the tiber valley, north of rome (minissale et al., 2002). the multiple origin(s) of co2 inside the mesozoic limestone, and related effects on water-rock interaction processes during the cruise of co2 across the shallow crust, was already proposed by minissale et al. (1997), which discriminated, in terms of δ13c in co2, four main sources in central italy: fig. 2 conceptual section of the larderello geothermal field in tuscany (after mi n i s s a l e, 1991) showing co2 patways from the geothermal system into the regional mesozoic aquifer. sezione concettuale del campo geotermico di larderello in toscana (modificata da minissale, 1991) che illustra la connessione tra le zone di produzione o di accumulo della co2, nonché il trasferimento di quest'ultima all'acquifero regionale nelle successioni carbonatiche mesozoiche. 1) atmospheric co2 in rainfall, with δ13c value of about -7‰ pdb (rollison, 1993). 2) biogenic co2 from soil, entering into solutions during infiltration of meteoric waters; typically with δ13c < 20‰ pdb (deines et al., 1974). 3) co2 deriving from the dissolution of carbonates during water-rock interaction, and typical of hydrothermal systems producing co2 with δ1 3c around 0‰ pdb (rollison, 1993) 4) mantle co2: a large source of co2 at plate boundaries (barnes et al., 1978) with δ13c in the range -4 to 7‰ pdb (rollison, 1993). the relationship between the carbon isotopic composition of travertine and its mother co2 was well studied in the 1960's (craig, 1963; fritz, 1965; gonfiantini et al., 1968; friedman, 1970), and in the 1970's the δ13c-co2, as a prospecting tool for geothermal energy, in both gas vents, thermal springs and travertine, was proposed by pa n i c h i & tongiorgi (1976). the latter, by measuring the carbon isotopic compositions of both precipitated travertine and exsolved co2 at 11 active travertine-depositing sites in central italy, proposed an empirical relation given by the equation: δ13cco2 = 1.2 δ13ctrav 10.5 to relate the δ13c value of the dissolved co2 from travertine and the δ13c value of the mother co2 promoting the pristine dissolution of limestone. hereafter, all the travertine δ1 3c discussed are not the values measured at the mass spectrometer, but are the values recalculated according to the relation proposed by panichi &tongiorgi (1976). 102 fig. 3 δ13c of co2 vs. δ13c in caco3 from actively-depositing travertine areas (gray squares; data after panichi & tongiorgi, 1976) and δ13c values of co2 "recalculated" from δ13c values of travertines according to the formula shown on top of the diagram. white and black circles refer to minimum and maximum measured δ13c values in each travertine outcrop area plotted versus the average recalculated δ13c of parent co2. δ13c della co2 vs. δ13c in caco3 per i travertini in formazione (quadrati grigi; dati in panichi & tongiorgi, 1976) e per i travertini fossili in cui il δ13c della co2 madre è ricalcolato da quello dei travertini, secondo la formula riportata nel diagramma. i pallini bianchi e neri si riferiscono rispettivamente ai campioni col minore e maggiore δ13c per ciascun deposito. δ13c (travertine) a. bertini, a. minissale & m. ricci such isotopic data (most of which are from minissale, 2004) are plotted in the δ13ctravertiniδ13cco2 diagram of figure 3. because of co2 fractionation effects during the flowing of mother waters in travertine precipitation pathways, the most negative δ1 3c value of a single fossil deposit (open white circle in fig. 3) represents the travertine formed near the emergence; the most positive (black dot) the more distal one. travertine deposits plotting on the top right portion of the diagram are all located around active or quaternary volcanic areas of central italy; those in the bottom left are associated with the cold karstic springs, with value of δ13c more negative typical of biogenic derived co2. the former (fig. 1), prevalently locate in the western sector of italy, have the typical massive appearance of thermogene travertine, the latter prevalently crop out in the intramontane areas of the apennine range (minissale et al., 2002), having the appearance of tufa. the cross comparison between data in figure 3 and the geographical distribution of average re-calculated δ13c in central italy (fig. 4), has two important implications: (1) the isotopic variability of carbon in the co2 sources is generally greater than the one induced by the fractionation during travertine deposition, as already suggested by the similar concentration of sr in the relative springs and travertine deposits (mi n i s s a l e, 2004), (2) both active and fossil travertine, being all of them younger than 500 ka (taddeucci & voltaggio, 1987; facc e n n a et al., 1994; mi n i s s a l e et al., 2002), derive by a regional hydrogeology that has not genetically changed much in the past 500 ka. the briefly summarized relationship between: i) the isotopic composition of travertine, ii) mother co2, iii) structure and morphology of the mesozoic limestone, in a similar hydrological pattern, implies that the carbon isotopic composition of a fossil travertine can be used as a prospecting tool for paleohydrology and for the presence of active and/or fossil geothermal and hydrothermal systems, as proposed by pa n i c h i & to ngiorgi (1976). 3 travertine as indicator of active tectonics the possibility of deriving paleohydrology with travertine has important aspects related to tectonics. a clear relationship between surface discharge of deep, c a c o3-oversaturated thermal fluids and active tectonics, was firstly pointed out by ha n c o c k et al. (1999). in their study, based on observations in several mediterranean areas, including some of the most wellknown deposits, such as tivoli in italy and pamukkale in turkey, they proposed the use of travertine deposits as indicators of active tectonics. here we discuss a case study in central italy, where we have used the elevation of the travertine to calculate tectonic uplift rate, in connection with the fact that the hydrology (in terms of paleohydrology) within the mesozoic carbonate aquifer, has reported in the previous paragraph, has apparently remained stable in the past 500 ka (mi n i s s a l e, 2004). 103 fig. 4 iso-distribution map of recalculated δ1 3c values of "parent" co2 of travertines; the figure shows more negative values in the inner parts of the apennines suggesting co2 of prevalent biogenic (soil) origin with respect to isotopically heavier co2 of metamorphic origin along the peri-tyrrhenian coast. mappa di isodistribuzione del δ1 3c della co2 “ m a d r e ” dei travertini: i valori più negativi si r invengono all'interno della catena, suggerendo per questi un'origine meteogenica, rispetto a quelli tirrenici in cui la co2 ha un'origine più profonda. use of quaternary travertines ... during a recent study in the travertine outcrops centered in the colfiorito area, and focused to find out relations between the earthquake occurred there in 1997 (ce l l o et al. , 2000) and the several active faults present in the area, all travertine deposits (fig. 5) were sampled, among others, for δ13c and δ1 8o measurements, and several of them dated (paladini, 2005). by considering that: i) it has been taken as representative of the paleohydrology the highest elevation of each single deposit (most of these deposits are in narrow valleys, with sometimes large vertical drops); i i) samples for dating where chosen, when possible, from the centre of the deposit in well exposed walls; and iii) only samples appearing relatively unaltered were dated (minissale et al., 2005). the most surprising result we obtained was to discover a strong positive correlation between the age of the single travertine deposits, their elevations, as well as their w-e geographical position inside the apennine chain (fig. 6). it is interesting to underlain that travertines located at present at an elevation of more than 800 m formed about 500 ka whereas travertines located at about 200-300 m are usually younger (or still active). it is also reasonable to suppose that old fossil travertine in the eastern sector of the apennine, now located at high elevation, formed in the past when the base level of the karstic circulation, at that time, was at a much lower elevation. according to several authors (e.g. boccaletti & sa n i, 1998), the apennines in their intramontane inner sectors are still under strong compression, and sti ll isostatically r ising. according to the data shown in figure 6, and supposing that the springs forming the travertine circulated in the same aquifer (i.e. the mesozoic limestone), an average isostatic uplift rate of about 0.7 mm/year can be estimated for this sector of the apennine range. the uplift rate calculated in this way is in line with the ones estimated with other methods in other areas of 104 fig. 5 geological sketch map of the 1997 colfiorito earthquake area in central italy with location of the main travertine outcrops nearby. mappa geologica dell'area del colfiorito (italia centrale) interessata dal terremoto del 1997 con l'ubicazione dei principali affioramenti di travertino. fig. 6 diagram of elevation versus age of travertine outcrops in the colfiorito area in central italy (minissale et al., 2005); from the diagram an isostatic rising spead of 0.7 mm/y can be calculated for this part of the apennines. diagramma di correlazione tra quote ed età dei travertini che affiorano nell'area del colfiorito in italia centrale (minissale et al., 2005); dal diagramma si evidenzia un tasso di sollevamento per la catena appenninica di 0.7 mm/anno. a. bertini, a. minissale & m. ricci the apennines, such as 0.4 mm/year using fission tracks (ba l e s t r i e r i et al., 1996), and 0.2-0.7 mm/year using vertical fault slip rates (bonini et al., 2003). 4 travertine as paleoclimate proxy although its potentiality is not well assessed yet, travertine could also be a very important proxy for paleoclimate reconstructions. in fact, it is reasonable to suppose that the δ1 8o of co3-ions in precipitated travertine might depend upon the δ1 8o of the ocean, via the isotopic composition of “mother” rainfalls entering the karstic circuits. more positive δ18o values are found in interglacial periods. this relation has been recently reviewed for tufa deposits in northern europe (andrews, 2006). what is peculiar with travertine is that the study of the variation of the δ13c of co3-ions, could give light on the contemporary origin of co2 inside the deep aquifer, and its proportion with atmospheric co2, as suggested in the previous paragraphs. other isotopic compositions (e.g. δ3 5s, δ8 7s r , δ208pb) and the concentration of some minor and trace elements of travertine (e.g. mg and sr), can also be useful indicators of climate-driven changes (sturchio et al., 1992; dramis et al., 1999). in the same perspective: incorporated pollen, aerosols, microbes, plant and animal macro-remains, and other organic matter, might all be potential indicators of environmental conditions. as a matter of fact, all these potentialities can be developed by applying precise age determinations, such as the u-series method (sturchio et al., 1994; frank et al., 2000; ma t s u o k a et al., 2001) to the denser layers of pure travertine, if they are younger than ca 500 ka. minissale et al. (2005) published 30 dates from the main travertine outcrops of central italy which, along with dates from the literature, provided an opportunity to compare periods of active travertine deposition with climatic cycles, obtained on a global scale with other proxies (e.g. martinson et al., 1987). as shown in figure 7, a good agreement between interglacial warm periods and the travertine deposition rates, at least for interglacials 1, 3, 5 and 7 is evident. the agreement is particularly striking if we consider that the sampling criteria for dating travertine deposits in central italy, was essentially random. the fact that some travertine dates correspond with glacial periods (e.g. two samples in glacial 4 and three in glacial 6), means that, in glacial periods, the precipitation of travertine was not entirely absent, but was probably reduced. because precise correspondence between isotopic fluctuations in travertine and climatic parameters in central italy has not been verified yet, investigations in the last years on stable isotopic compositions (δ1 8o , δ1 3c) and palynological analyses in two pleistocene sites (serre di rapolano siena, and tivoli rome; bertini et al., 2007; ricci, 2007; ricci et al., 2007) were carried out. what we obtained at serre di rapolano is summarized below. at rapolano (fig. 1 for location), three different sites (al ibrando-dei=ad, fil icheto=f and le querciolaie=lq) have been selected and sampled for both palynological and stable isotopic analyses. the relative sections and stratigraphic profiles, including the 13.5 m core at lq, are shown in figure 8. in order to better evaluate the taphonomic biases affecting the pollen content in travertines an uncommon lithology for palynological studies samples were collected from: i) different travertine lithotypes (e.g. crystalline crust, shrub, lithoclastic), ii) terrigenous interstrata and iii) paleosoils. taphonomic biases have also been assessed in samples from surface water and soft bottom sediment, from a small pool where travertine precipitates nowadays (borro canatoppa) (fig. 9). samples from musci were also taken next to the pool edge. preliminary data, summarized in figures 10-12, document the main floristic, vegetational and climatic changes observed. sixty-nine pollen morphotypes have been identif ied, at the family and generic levels. they have been referred to twentyseven arboreal (e.g. p i n u s , carpinus, quercus, ulmus, tilia) and to thirty-eight non arboreal (e.g. poaceae, asteraceae, chenopodiaceae, cyperaceae, sparganiaceae) taxa. p s e u d oschizaea sp., pteridophyta and fungi have also been detected. with the exception of sparse pol len grains of t a x o d i u m , m y r i c a and e n g e l h a r d i a in the ad section, taxa more typical of pre-pleistocene are absent. among pinaceae, largely dominated by pinus, cedrus is continuously present, whereas tsuga is more scattered. the most encouraging result of 105 fig. 7 climatic cycle variations for the past 340 ka derived from the δ18o of the ocean as registered in the tests of benthonic foraminifera (thick black line) and the co2 concentration of the atmosphere (thin line) as registered in ice core samples (redrawn after paillard, 1998; petit et a l., 1999; sh a c k l e t o n, 2000). singles dated travertine are shown in the lower part of the diagram. cambiamenti climatici durante gli ultimi 340 ka registrati nel record biostratigrafico e isotopico (δ1 8o) dei foraminiferi bentonici (linea nera spessa) e nella co2 intrappolata nei ghiacci delle calotte polari (linea sottile) (ridisegnato da paillard, 1998; petit et al., 1999; shackleton, 2000). i singoli travertini datati sono segnati nella parte bassa del diagramma. use of quaternary travertines ... 106 fig. 8 stratigraphic exposures of the alibrando-dei and le querciolaie quarries at serre di rapolano. relazioni stratigrafiche tra i depositi studiati a cava le querciolaie e cava alibrando-dei (serre di rapolano). a. bertini, a. minissale & m. ricci 107 fig. 9 borro canatoppa thermal water near serre di rapolano. local plant species are largely represented in the summary pollen spectra from: (a) the caco3 saturated thermal water, and (b) the related soft sediment precipitating at the bottom of the pond. the bordering vegetation (mainly araliaceae, included in the shrubs) is reflected, especially in the pollen spectrum (a), clearly marked by a dominant seasonal input too. the difference in percentage between (a) and (b), possibly is also related to destruction of palynomorphs during diagenesis. pozza di acqua termale in prossimità del borro canatoppa vicino a serre di rapolano. gli spettri pollinici relativi all'acqua termale superficiale (a) e al travertino appena deposto sul fondo della pozza (b) mostrano una generale dominanza della componente pollinica locale. nello spettro pollinico dell'acqua termale (a) risulta inoltre marcata anche la componente stagionale (araliaceae arbusti), molto meno evidente nello spettro (b) nel quale le associazioni polliniche risultano dall'accumulo di polline lungo più stagioni. le differenze nei valori percentuali tra gli spettri (a) e (b) sembrano inoltre essere legate anche agli effetti di distruzione selettiva durante la fase di diagenesi. fig. 10 alibrando-dei quarry: summary pollen diagram. pollen of arboreal plants (ap) is dominant (85%) in the basal sample (ca1); ap consists prevalently of pinaceae, especially pinus followed by abies and cedrus; deciduous forest taxa are subordinate (always below 2%). herbs (about 15%) include: asteraceae, poaceae, chenopodiaceae; they progressively increase in the overlaying samples, reaching a maximum of 80% in ca9. artemisia shows a peak in the ca6. scanty pollen grains of engelhardia, taxodium and myrica have been also detected. cava alibrando-dei: diagramma pollinico sintetico. nel campione alla base (ca1) domina il polline delle piante arboree (ap) (85%); queste sono prevalentemente costituite da pinaceae, soprattutto pinus seguito da abies e cedrus; i taxa arborei decidui sono sempre in percentuali inferiori al 2%. le erbacee (asteraceae, poaceae e chenopodiaceae; ca 15%), aumentano progressivamente nei campioni sovrastanti raggiungendo percentuali massime pari all'80% (ca9). artemisia ha un picco nel campione ca6. presenti anche rari granuli pollinici di engelhardia, taxodium e myrica. use of quaternary travertines ... this survey is the discovery of clearly distinct pollen assemblages, recording different paleoenvironmental and paleoclimatic conditions. the pollen record allows also discrimination between local and regional events (figs. 10-12). the local one, as pointed out at the base of lq, is mainly testified by the development of herbaceous vegetation, typical of wetlands (i.e. marshes); the regional one, by the expansion of steppe taxa, especially artemisia (e.g. at filicheto and in ct14 of lq), or arboreal taxa such as pinus and quercus (sample ct9 of lq). regional events possibly correspond to climatic changes correlative with stadial/interstadial fluctuations. comparison between pollen and isotopic data is complicated by the fact, sometimes, that the more compact lithotypes formed near the orifice (e.g. crystalline crust formed in slope; guo & riding, 1998) have low pollen concentration. in spite of this, data presented here, suggest a quite good correlation between the isotopic and the pollen fluctuations in the lq core. a parallel increase of δ1 8o values (up to ca 2,5‰), and percentages of arboreal pollen (pinaceae and temperate broad-leaved deciduous temperate taxa) has been recorded in the middle portion of the core (fig. 11). according to the nine radiometric ages provided by bellucci (2007), the lq core is supposed to cover a time interval between ca 60 and 30 ka, partly coinciding with the middle weichselian and the marine isotopic stage 3. at rapolano, during this time interval, the wide expansion of herbaceous plants (including artemisia) suggests the presence of open landscapes, indicative of cold and dry conditions. however a relatively more humid and warm phase is testified by the increase of the arboreal plants in correspondence of the central portion of lq core. the sporadic presence of engelhardia, taxodium and myrica in the ad profile (fig. 10), if not due to reworking, could be indicative of a long hiatus among the ad and the lq core. if the age of the upper part of lq core is at 30 ka, the large expansion of thermophilous taxa, indicative of warm 108 fig. 11 le querciolaie quarry. a) summary pollen diagram of the travertine core (tc) retrieved and previously studied for δ13c, δ18o and u/th datation by bellucci (2007); on the left isotopic data (ricci, 2007). b) summary pollen diagram from the terrigenous deposits intercalated within tc. for the legend of the pollen diagram see figure 10. a dominant edaphic signature is well expressed by the large occurrence of cyperaceae at the bottom core (ct2). ca15 and ca17 contain abundant herbaceous pollen grains, but within hydrophytes are strongly reduced. a good expansion of temperate broad-leaved deciduous forest taxa is testified in sample ct9; here pinaceae also increases, especially pinus, followed by cedrus and abies; then herbs increase again, reaching maximum values in ct16 (88%) and ct22 (ca 80%), with poaceae and asteraceae asteroideae. a good expansion of artemisia is recorded at the same time of an increase of pinaceae in ct14. cava le querciolaie. a) diagramma pollinico sintetico della carota di travertino (tc) prelevata e studiata (δ13c, δ18o e datazioni u/th) da bellucci (2007); sulla sinistra sono riportati i valori isotopici del carbonio e dell'ossigeno (ricci, 2007). b) diagramma pollinico sintetico dei depositi terrigeni intercalati a tc. per la legenda dei diagrammi palinologici si veda la figura 10. un forte segnale edafico è rappresentato dalla marcata presenza di piante acquatiche (cyperaceae) nella parte basale della carota (ct2). nei campioni ca15 e ca17 sono ben documentate le piante erbacee mentre le idrofite sono fortemente ridotte. una buona espansione dei taxa di foresta temperata è testimoniata nel campione ct9; qui aumentano anche le pinacee, prevalentemente pinus, seguito da cedrus e abies. nei campioni soprastanti le erbacee aumentano di nuovo (poaceae ed asteraceae asteroideae), raggiungendo i valori più elevati in ct16 (88%) e ct22 (80%). nel campione ct14 si osserva una buona espansione di artemisia e pinaceae. a. bertini, a. minissale & m. ricci and humid conditions, found at the very top of lq grading into the surface soil (figs. 8 and 13), could be related to some later pleistocene interstadials or the holocene. the dominance of asteraceae in the soil is clearly related to the usual pedogenic processes. 5 conclusion italy (more generally the entire mediterranean region) with the large number of extensive limestone outcrops and frequent thermal anomalies associated to active volcanism, is an ideal place for travertine formation. as proposed by panichi & to n g i o r g i (1976) in a pioneering paper, travertine is a powerful tool for geothermal energy prospecting. on the other side, the δ13c values of travertine can be also used to trace the source of co2 (e.g. atmospheric, biogenic, hydrothermal, mantle) and relations with underground water-gasrock interaction processes (minissale et al., 2002). more than this, travertine can be used also as a powerful tool for investigate active tectonics (ha n c o c k et al., 1999) and, as presented in this study, to calculate the average rising speed of an active orogen, such as the central-southern apennines. such a relation, constrained by the reasonable hypothesis that the circulation paths inside the mesozoic limestone have remain stable in the last 500 ka, can also be used to trace the paleohydrology of central-southern italy. in terms of potentiality for paleoclimate reconstructions, the parallel stable isotopic (δ1 8o, δ1 3c) and palynological analyses carried out in two pleistocene travertines of central italy, i.e. serre di rapolano (siena) and tivoli (in progress), allowed to investigate the last ca 120 kyrs. the observed environmental fluctuations at both sites demonstrate that travertine deposits, can be used, such as tufa, to investigate the paleoclimate of the late quaternary. detailed palynological studies are still in progress, they will facilitate a closer comparison with other terrestrial (e.g. monticchio, allen et al., 2000; valle di castiglione, follieri et al., 1988; lagaccione, magri, 1999), ice-core, as wells as deep-sea (e.g. martinson et al., 1987; dansgaard et al., 1993; grootes et a l., 1993; bo n d et al., 1993) records. in line with this interpretation, is the already described observation that most dated travertine in central italy cluster in intergla109 fig. 13 soil profile at the top of le querciolaie quarry: summary pollen diagram (for the legend of the pollen diagram see figure 10). with the exception of the basal sample (cs11) where pollen from arboreal plants is abundant (ca 70%), pollen spectra from the soil are dominated by herbaceous plants (asteraceae cichorioideae). suolo al tetto di cava le querciolaie: diagramma pollinico sintetico (per la legenda palinologica si veda la figura 10). ad eccezione del campione basale prelevato nel travertino (cs11), dove il polline delle piante arboree è abbondante (ca 70%), i campioni prelevati nel suolo sono dominati da erbacee come asteraceae cichorioideae. fig. 12 filicheto quarry: summary pollen diagram (for the legend of the pollen diagram see figure 10). this single sample was collected to have taphonomical information on the pollen content in a less compact and more alterated lithotype. herbs (73%), including poaceae, asteraceae (with artemisia at 11%) and p l a n t a g o, dominate. among the arboreal plants p i n u s i s the most abundant component. cava filicheto: diagramma pollinico sintetico (per la legenda del diagramma palinologico si veda la figura 10). il campionamento palinologico di questo livello di travertino è giustificato dalla necessità di ottenere informazioni tafonomiche da litotipi poco compatti e alterati. dominano le erbacee (ca 73%), come poaceae, asteraceae inclusa a r t e m i s i a (11%) e p l a n t a g o. tra le piante arboree pinus è il componente principale. use of quaternary travertines ... cial periods. and this seems reasonable for two reasons: 1) because the deposition of travertine is depending upon rainfall amounts, and 2) because in glacial periods, the lower level of the oceans also lowers the base level of karstic circulation. 6 references allen j.r.m., wa t t s w.a. & hu n t l e y b. (2000) weichselian palynostratigraphy, palaeovegetation and palaeoenvironment; the record from lago grande di monticchio, southern italy quaternary international, 73/74, pp. 91-110. andrews j.e. (2006) palaeoclimatic records from stable isotopes in riverine tufas: synthesis and review earth sci. rev., 75, pp. 85-104. balestrieri m.l., abbate e. & bigazzi g. (1996) insights on the thermal evolution of the ligurian apennines (italy) through fission-track analysis j. geol. soc. of london, 153, pp. 419-425. barnes i., irwin w. & white d. (1978) global distribution of co2 and major zones of seismicity u.s. geol. surv., open-file rep. 78-39. be l l u c c i f. (2007) stable isotope stratigraphy of the travertines of rapolano terme, italy unpublished master's thesis in earth and environmental science, university of illinois at chicago. berner r.a., lasaga a.c. & garrels r.m. (1983) the carbonate-silicate geochemical cycle and its effect on atmospheric carbon dioxide over the past 100 ma am. j. sci., 283, pp. 641-683. be r t i n i a., mi n i s s a l e a., ri c c i m. & va s e l l i o. (2007) pleistocene travertines of central italy: paleoenvironmental reconstruction from pollen and stable isotopes geosed 2007, pp. 10. boccaletti m. & sani f. (1998) cover thrust reactivations related to internal basement involvment during neogene-quaternary compressive events in the tyrrhenian side of the northern apennines tectonics, 17, pp. 112-130. bond g., broecker w., johnsen s., mcmanus j., labeyrie l., jouzel j. & bonani g., (1993) correlations between climate records from north-atlantic sediments and greenland ice nature, 365, pp. 143147. bo n i n i m., ta n i n i c., mo r a t t i g., pi c c a r d i l. & sa n i f . (2003) geological and archaeological evidence of active faulting on the martana fault (umbriamarche apennines, italy) and its geodynamic i m p l i c a t i o n s j. of quaternary science, 1 8, pp. 695-708. ceccarelli a., celati r., grassi s., minissale a. & ridolfi a. (1987) the southern boundary of larderello geothermal field geothermics, 16, pp. 505-515. ce l l o g., de i a n a g., ma r c h e g i a n i l., ma z z o l i s., to n d i e., ferreli l., maschio l., michetti a. m., serva l. & vi t t o r i e. (2000) geological constraints for earthquake faulting analysis in the colfiorito area special issue: "the umbria-marche, central italy, seismic sequence of 1997-1998", a. amato and m. cocco (eds.), journal of seismology, 4, pp. 357-364. cr a i g h. (1963) the isotopic geochemistry of water and carbon in geothermal areas in: “nuclear geology on geothermal areas”, e. tongiorgi (ed.), italian council for reasearch publish., spoleto, italy, pp. 17-54. dansgaard w., johnsen s.j., clausen h.b., dahljensen d., gundestrup n.s., hammer c.u., hvidberg c.s., st e f f e n s e n j.p., sv e i n b j o r n s d o t t i r a.e., jo u z e l, j., & bond g., (1993) evidence for general instability of past climate from a 250-kyr ice-core record nature, 364, 218-220. de i n e s p., la n g m u i r d. & ha r m o n r.s. (1974) s t a b l e carbon isotope ratios and the existence of a gas phase in the evolution of carbonate groundwaters geochim. cosmochim. acta, 38, pp. 1147-1164. dramis f., materazzi m. & cilla g. (1999) influence of climatic changes on freshwater travertine depositing: a new hypothesis phys. chem. earth, 24, pp. 893-897. fa c c e n n a c., fu n i c e l l o r., montone p., parotto m. & voltaggio m. (1994) late pleistocene strike-slip tectonics in the acque albulae basin (tivoli, latium) mem. descr. carta geol. ital., 4 9, pp. 37-50. farmer j.d. (2000) hydrothermal system: doorways to early biosphere evolution geol. soc. am., 10, n. 7, pp. 1-9. follieri m., magri d. & sadori l. (1988) 250,000-year pollen record from valle di castiglione (roma) pollen et spores, 30, pp. 329-356. ford t.d. & pedley h.m. (1996) a review of tufa and travertine deposits of the world earth sci. rev., 41, pp. 117-175. frank n., braum m., hambach u., mangini a. & wagner g. (2000) warm period growth of travertine during the last interglaciation in southern germany quat. res., 54, pp. 38-48. friedman i. (1970) some investigations of the deposition of travertine from hot-springs; the isotopic chemistry of a travertine-depositing spring geochim. cosmochim. acta, 34, pp. 1303-1315. fritz p. (1965) composizione isotopica dell'ossigeno e del carbonio nei travertini della toscana boll. geofis. teor. e appl., 7, pp. 25-30. go n f i a n t i n i r., pa n i c h i c. & to n g i o r g i e. (1968) isotopic disequilibrium in travertine deposition earth planet. sci. lett., 5, pp. 55-59. grootes p.m., stuiver m., white j.w.c., johnsen s. & jouzel j. (1993) comparison of oxygen isotope records from the gisp2 and grip greenland ice cores nature, 366, 552-554. guo l. & riding r. (1998) hot-spring travertine facies and sequences, late pleistocene, rapolano terme, italy sedimentology, 45, pp. 163-180. hancock p.l., chalmers r.m.l., altunel e. & cakir z. (1999) travitonics: using travertines in active fault studies j. struct. geol., 21, pp. 903-916. magri d. (1999) late quaternary vegetation history at lagaccione near lago di bolsena (central italy) review of paleobotany & palynology, 1 0 6, pp. 171-208. martinson d.g., pisias n.g., hays j.d., imbrie j., moore t.c. & shackleton j. (1987) age dating and the orbital theory of the ice ages: development of a high-resolution 0 to 300,000-year chronostratigraphy quat. res., 27, pp. 1-29. matsuoka j., kano a., oba t., watanabe t., sakai s. & 110 a. bertini, a. minissale & m. ricci seto k. (2001) seasonal variation of stable isotopic compositions recorded in a laminated tufa, sw-japan earth planet. sci. lett., 191, pp. 3144. minissale a. (1991) the larderello geothermal field: a review earth sci. rev., 31, pp. 133-151. minissale a. (2004) origin, transport and discharge of co2 in central italy earth sci. rev., 66, pp. 89141. minissale a., evans w.c., magro g. & vaselli o. (1997) multiple source components in gas manifestations from north-central italy chem. geol., 142, pp. 175-192. minissale a., kerrich d., magro g., murrell m.t., paladini m., rihs s., sturchio n.c., tassi f. & vaselli o. (2002) structural, hydrological, chemical and climatic parameters affecting the precipitation of travertines in the quaternary along the tiber valley, north of rome earth planet. sci. lett., 203, pp. 709-728. mi n i s s a l e a., pa l a d i n i m. & st u r c h i o n.c. (2005) travertine of central italy: relation between genesis, tectonics and paleoclimate proc. 1s t congress on travertine, 21-25 sept. 2005, pamukkale, turkey, pp. 106-115. pa i l l a r d (1998) the timing of pleistocene glaciation from multiple-state climate model nature, 3 9 1, pp. 378-381. pa l a d i n i m. (2005) implicazioni paleoclimatiche, idrogeologiche e strutturali nella deposizione dei travertini dell'italia centrale unpublished phd thesis, university of florence. panichi c. & tongiorgi e. (1976) carbon isotopic composition of co2 from springs, fumaroles, mofettes and travertines of central and southern italy: a preliminary prospection method of geothermal a r e a proc. 2n d un symp. on the develop. and use of geotherm. energy, 20-29 may 1975, san francisco, u.s.a., pp. 815-825. petit j.r., jouzel j., raynaud d., barkov n.i., barnola n.i., basile i., bander m., chappellaz j., davis m., de l a y g u e g., de l m o t t e m., ko t l y a k o v v . m . , legrand m., lipenkov v.y., lorius c., pepin l., ritz c., sa l t m a n e. & stievenard m. (1999) c l i m a t e and atmospheric history of the past 420.000 years from the vostok ice core, antartica nature, 399, pp. 429-436. ricci m. (2007) paleoambiente e paleoclima del tardo pleistocene registrati attraverso l'indagine palinologica e pedologica nei depositi di travertino di rapolano unpublished thesis, university of florence. ricci m., bertini a. & minissale a. (2007) pollen analysis of the travertine deposits of serre di rapolano (central italy): implications for environmental reconstructions of the late quaternary geoitalia 2007, pp. 287. ro l l i s o n h. (1993) using geochemical data longman, london, u.k., 352 pp. sh a c k l e t o n n.j. (2000) the 100.000-year ice-age cycle identified and found to lag temperature, carbon dioxide, and orbital eccentricity science, 289, pp. 1897-1902. sturchio n.c., murrell m.t., pierce k.l. & sorey m.l. (1992) yellowstone travertines: u-series ages and isotope ratios (c, o, sr, u) in water-rock interaction, v. 2 (ed. y. kharaka & a. maest), balkema, rotterdam, pp. 1427-1430. sturchio n.c., pierce k.l., murrell m.t. & sorey m.l. (1994) u-series ages of travertines and timing of the last glaciation in the northern yellowstone area, wyoming-montana, u.s.a quat. res., 41, pp. 265-277. taddeucci a. & voltaggio m. (1987) th-230 dating of the travertines connected to the vulsini mts. volcanism (northern latium, italy): neotectonics and hydrogeology per. mineral., 56, pp. 295-302. 111 ms. ricevuto il 13 marzo 2008 testo definitivo ricevuto il 4 aprile 2008 ms. received: march 13, 2008 final text received: april 1, 2008 use of quaternary travertines ... pag99_112 bertini et al available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 109 112 palynological characterization of the po delta succession (northern italy): holocene vegetation dynamics, stratigraphic patterns and palaeoclimate variability marco cacciari 1 , veronica rossi 1 , marco marchesini 2 , alessandro amorosi 1 , luigi bruno 1 , bruno campo 1 1 department of biological, geological and environmental sciences, university of bologna, bologna, italy 2 laboratorio di palinologia e archeobotanica c.a.a. giorgio nicoli, san giovanni in persiceto, bologna, italy corresponding author: m. cacciari <marco.cacciari3@unibo.it> abstract: the 40 m-long core em2, recovered in the innermost portion of po delta plain, was sampled for palynological analysis, in order to link coastal-deltaic facies architecture to vegetation dynamics and holocene climate variability. pollen data refine facies characterization of the 25 m-thick holocene succession: freshwater swamp clays alternating with overbank/channel sands document millennial to centennial-scale water table oscillations that invariably peak in correspondence of peaty layers. pollen signature allows identification of the landward equivalent of the maximum flooding surface atop the 7.6 ka-dated peaty interval and furnishes new insights on the relationship between coastal facies patterns and climate events. keywords: palynology, holocene, po delta plain, climate events, sequence stratigraphy 1. introduction mediterranean delta plains are considered natural archives of the interactions between holocene depositional, climate and human dynamics. in these regions, the combined effect of high sea-level conditions, remarkable rates of subsidence and sediment supply led to the deposition of stratigraphically expanded, relatively continuous fine-grained sedimentary successions, useful for high-resolution palaeoenvironmental and stratigraphic reconstructions. the po delta plain is one of the most studied mediterranean deltas. a detailed characterization of sedimentary facies and a high-resolution sequencestratigraphic framework (with the identification of a set of millennial-scale parasequences) is available for the 1030 m-thick holocene succession (amorosi et al., 2017). however, the relationships between parasequence development and the well-known millennial-scale climate variability (bond’s events sensu bond et al., 1997) are still matter of debate. furthermore, palynology is a relatively unexplored stratigraphic tool for the identification of flooding surfaces within successions devoid of marine -influenced facies. through an integrated palynologicalstratigraphic approach, this study aims to reconstruct post-glacial stratigraphic patterns at the landward margin of the po delta and to unravel their relations with holocene climate events. 2. material and methods a 40 m-long core, recovered in the innermost portion of the po delta plain (core em2), was selected for palynological analysis, being composed of a ~25 m thick, chronologically well constrained (9 radiocarbon ages) paludal succession, framed into a robust stratigraphic context and dated to last ~13 ka (amorosi et al., 2017; bruno et al., 2017). thirty-seven samples were collected, with special focus on organic-rich, fine-grained intervals, where a rich palynological association was expected. about 3-9 g of dry sediment per sample were weighed and then a lycopodium tablet was added to calculate pollen concentration. samples were mechanically disrupted in a 10% na-pyrophosphate solution and filtered. then, each sample underwent the following treatments: 10% hcl solution, acetolysis, enrichment with a heavy liquid, 40% hf solution, ethanol suspension and evaporation at 60 °c. finally, microscope slides were prepared with glycerine jelly and paraffin. for each sample, at least 300 grains were counted and recognised after reille (1992). species ecological characterisation and pollen groups were based on pignatti (1982, 2017). on the other hand, non-arboreal pollen (nap) was split into herbaceous plants (h) and shrubs (sh) to better estimate the canopy thickness. 3. pollen sequence the em2 pollen spectra reported in fig. 1 confirm the persistence, at the study site, of freshwater conditions throughout the holocene (absence of halophytes) and highlight the vertical succession of fifteen pollen zones-pzs that correspond to distinct vegetation phases. in particular, a series of lateglacial-holocene climatic events were identified by combining high-frequency changes in relative abundance of specific pollen groups (fig. 1) with the available radiocarbon ages. all these events are marked by relative peak concentrations of montane trees-mt (6-10%) and/or cold steppe taxa-cst (3-8%), indicative of sudden cooling, sharply followed by https://doi.org/10.26382/aiqua.2018.aiquaconference 110 fig. 1 sedimentology and pollen characteristics of core em2: pt (pleistocene taxa), cf (conifers) mt (montane trees), cst (cold steppe taxa), m (mediterranean trees), q+other dt (mixed-oak forest and other deciduous trees), h (woody hygrophytes), hyg (herbaceous hygrophytes), hel (helophytes), hyd (hydrophytes), pm (pasture-meadow). facies: fl. ch. (fluvial channel), distr. ch. (distributary channel), crs (crevasse splay), fpl (floodplain), pdf (poorly-drained floodplain), sw (swamp). the “p” subscript indicates a weakly pedogenised deposit. ps: parasequence (light blue lines are parasequence boundaries; dotted lines indicate minor flooding surfaces). mfs: maximum flooding surface. sb: sequence boundary from bruno et al. (2017). cacciari m. et al. 111 high percentages of climate optimum indicators (i.e., holm oak-mixed-oak forest, m-q+other dt) within a relatively continuous stratigraphic interval, a few tens of centimetres thick. along the core, conifers show similar vertical variations relative to mt+cst and, thus, were interpreted as a regional pollen rain, analogous to the cold indicators sensu stricto. the oldest cold spell (pz 13), chronologically attributed to the younger dryas event, occurs within the uppermost portion of the fluvial channel succession deposited under glacial-lateglacial conditions (amorosi et al., 2017; pzs 14-13) and observed between ~35.5-26 m core depth (fig. 1). the overlying, 25 m-thick sedimentary succession, composed of alternating swamp clays and overbank/ channel sands is assigned to the holocene period, based on combined radiocarbon ages and pollen data (pzs 12-1), the latter reflecting an overall climateoptimum-like vegetal landscape. however, three distinct phases of rapid cooling are recognised and reasonably ascribed to the preboreal oscillation (pz 11), boreal oscillation (pz 9) and 8.2 ka event (pz 7), respectively. more uncertain are dating and interpretation of other two cooling events recorded by pzs 5 and 3. finally, a relatively high concentration of mt and cst (7% total), paralleled by a sharp decrease in holm oak (from 13% to 1%), is recorded at the top (1 m) of the cored succession, within pedogenized floodplain deposits, possibly documenting the little ice age event. 4. holocene vegetation dynamics and facies stacking patterns the palynological analysis also refines facies characterization, especially of fine-grained deposits, allowing the distinction between poorly drained floodplain facies, characterised by the absence or scarcity of helophytes and hydrophytes, and swamp clays. moreover, two types of swamp deposits were identified within the holocene succession on the basis of the relative abundances of woody and herbaceous hygrophytes, helophytes and hydrophytes: peaty swamp (sw1): herbaceous wetland community with sparse alder carrs tolerating prolonged periods of radical drowning (helophytes) or aquatic plants (hydrophytes); subordinate hygrophytes, poaceae and alder (mixed or not) bordering the locally flooded depressions. this pollen assemblage, invariably recorded within peaty layers (~10-30 cm thick), indicates relatively high water table conditions. swamp (sw2): open to dense alder carr with a mixed oak-holm oak ecological component in subordinate position. this pollen assemblage, found within organic-rich grey to dark grey clays, documents a relatively low water table. throughout the holocene succession, sw1 peats are vertically constrained between sw2 clays, which in turn are commonly overlain by crevasse splays or distributary-channel sandy deposits containing a pollen assemblage indicative of a hygrophilous, open to dense mixed oak-holm oak forest. this repeated stacking pattern of facies tracks short-term (millennial to submillennial scale) oscillations in the relative water table, allowing the identification of small-scale, t-r depositional cycles (i.e., parasequences bounded by flooding surfaces-fss) in a fully freshwater sequence. specifically, each cycle is composed of basal sw2 grey-dark grey clays, commonly showing an upward increase in dispersed organic matter, and culminates into a peaty interval (sw1 that reflects the most drowned conditions). upwards, a shallowing-upward trend is identified by pollen data, marking the progradational part of the parasequence (ps). furthermore, an overall increase in water table was recorded from the oldest swamp (dated around 11455±195 cal yrs bp) to the swamp recorded at ~13.35 m core depth and dated to 7675±75 cal yrs bp. this deepening-upward trend is considered as the sedimentary expression of the maximum flooding surface mfs at proximal locations. upwards, swamps generally show less developed peat accumulation and a lower water table relative to the underlying transgressive swamps. 5. discussion and conclusions diagnostic changes in vegetation patterns enable the precise documentation of parasequence development at the landward margin of the po delta plain during the holocene. therefore, because of the absence of meiofauna and molluscs in this freshwater paludal succession, the sequence-stratigraphic refinement at a millennial – sub-millennial scale was performed by palynological analysis. throughout core em2, the relative abundances of woody and herbaceous hygrophytes, helophytes and hydrophytes record alternating periods of rising water table (i.e., flooding events), which peak in correspondence of cm to dm-thick peaty swamp intervals (i.e., the most drowned conditions within each ps), and which subsequently decreases. the highest relative water table was reached atop the peaty swamp deposit belonging to ps 4 and dated to ~7600 cal yrs bp (fig. 1), which separates a set of transgressive parasequences from the highstand ones. highstand parasequences are characterised by the development of peaty swamp intervals under lower water table conditions, reflecting the general progradation of the po delta system during the mid-late holocene. these data, supported by the chronological and the stratigraphic frameworks available for the entire study area (amorosi et al., 2017; bruno et al., 2017; campo et al., 2017), suggest a strong allogenic control (i.e., glacio-eustatic oscillations at the milankovitch time-scale) on depositional dynamics ca. 35 km upstream from the modern coastline. a unique exception is the uppermost peaty layer, recorded at 3 m core depth and dated to ~1000-1100 cal yrs bp, which reflects the local establishment of a high water table possibly related to the historical po river avulsion in ficarolo. the northward shift of the po river system and the subsequent marked reduction in sediment supply reasonably induced the flooding of the southern portion of the subsiding po delta plain, where em2 core was recovered. the comparison between stratigraphic and pollenderived climatic data documents a complex interaction between parasequence development and holocene climate events. not all peats (sw1-peaty swamps) devel holocene palynology of the po delta succession oped under mild conditions, suggesting the influence of other driving mechanisms, such as early holocene eustatic jumps (mwp-melt water pulse) and autogenic factors. on the other hand, the thick alluvial successions in the uppermost portions of pss 2, 3 and 6 saw the development of cool-temperate communities, the eldest of which was chronologically constrained to the 8.2 ka event. as a whole the three pss suggest a strong sedimentary response to these short-term phases of climatic cooling in terms of increased sedimentary input and partial filling of paludal basins. acknowledgements this project, supported by rfo funds at university of bologna-italy (aa and vr), was possible thanks to a collaborative research project supported by exxonmobil upstream research company (grant to a. amorosi) and to the strong collaboration with centro agricoltura e ambiente “g. nicoli” laboratory (san giovanni in persiceto, bologna). references amorosi a., bruno l., campo b., morelli a., rossi v., scarponi d., hong w., bohacs k. m., drexler t. m. (2017) global sea-level control on local parasequence architecture from the holocene record of the po plain, italy. marine and petroleum geology, 87, 99-111. bond g., showers w., cheseby m., lotti r., almasi p., demenocal p., priore p., cullen h., hajdas i., bonani g. (1997) a pervasive millennial-scale cycle in north atlantic holocene and glacial climates. science, 278, 1257-1266. bruno l., bohacs k.m., campo b., drexler t.m., rossi v., sammartino i., scarponi d., hong w., amorosi a. (2017) early holocene transgressive palaeogeography in the po coastal plain (northern italy). sedimentology, 64, 1792-1816. campo b., amorosi a., vaiani s.c. (2017) sequence stratigraphy and late quaternary paleoenvironmental evolution of the northern adriatic coastal plain (italy). palaeogeography, palaoclimatology. palaeoecology, 466, 265-278. pignatti s. (1982) flora d’italia. edagricole, bologna, italy. pignatti s. (2017) flora d’italia, 1-2. edagricole, bologna, italy. reille m. (1992) pollen et spores d’europe et d’afrique du nord. laboratoire de botanique historique et palynologie, marseille, france, pp. 331. 112 cacciari m. et al. ms. received: may 10, 2018 final text received: may 23, 2018 amq abs zerboni et al tepro 253-256.pub available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 253 256 towards a map of the upper pleistocene loess of the po plain loess basin (northern italy) andrea zerboni 1, rivka amit 2, carlo baroni 3, mauro coltorti 4, m. francesca ferrario 5, gianfranco fioraso 6, m. gabriella forno 7, chiara frigerio 5, franco gianotti 7, andrea irace 6, franz livio 5, guido s. mariani 1, alessandro m. michetti 5, giovanni monegato 6, paolo mozzi 8, giuseppe orombelli 9, alessandro perego 1, naomi porat 2, ivano rellini 10, luca trombino 1, mauro cremaschi 1 1 dipartimento di scienze della terra “a. desio”, università degli studi di milano, milano, italy 2 geological survey of israel, jerusalem, israel 3 dipartimento di scienze della terra, università degli studi di pisa, pisa, italy 4 dipartimento di scienze fisiche, della terra e dell’ambiente, università di siena, siena, italy 5 dipartimento di scienza e alta tecnologia, università degli studi dell’insubria, como, italy 6 igg cnr, torino, italy 7 dipartimento di scienze della terra, università degli studi di torino, torino, italy 8 dipartimento di geoscienze, università degli studi di padova, padova italy 9 dipartimento di scienze dell’ambiente e della terra, università degli studi di milano-bicocca, milano, italy 10 dipartimento del territorio e delle sue risorse, università di genova, genova, italy corresponding author: a. zerboni <andrea.zerboni@unimi.it> abstract: upper pleistocene (mis 4–2) loess sequences occur in most of continental europe and in northern italy along the po plain loess basin. loess is distributed along the flanks of the po plain and was deposited on glacial deposits, fluvial terraces, uplifted isolated hills, karst plateaus, slopes and basins of secondary valleys. loess bodies are generally tiny and affected by pedogenesis, being locally slightly reworked by slope processes and bioturbation. notwithstanding, loess in the po plain is an important archive of paleoenvironmental record and its mapping provides new insights in paleoenvironmental and palaeoseismic reconstructions of northern italy. keywords: loess, po plain loess basin, upper pleistocene, mapping 1. introduction in the framework of european terrestrial palaeorecords, loess is one of the best archives for quaternary palaeoenvironmental reconstruction (e.g. smalley & leach, 1978; coudé-gaussen, 1990; pye, 1995; cremaschi, 2004). maps published in the last decade that present the distribution of loess in europe eliminate loess outcrops in northern italy or, alternatively, define them as loess derivates (haase et al., 2007; bertran et al., 2016; lindner et al., 2017). as a consequence, despite systematic studies carried out on the upper pleistocene loess sequences at the margin of the po plain (see cremaschi, 1987, 2004 and references therein), loess in northern italy is overlooked in comparison to the classical sequences described in continental europe (amit & zerboni, 2013), and crucial data are excluded from the interpretation of loess formation at a continental scale. for this reason, in the last few years we revised the sedimentological, paleoenvironmental, and geochronological data regarding the loess from the po plain loess basin (pplb), including new data derived from studying some classical loess outcrops (e.g., ferraro, 2009; wacha et al., 2011; cremaschi et al., 2015; cremaschi & zerboni, 2016), as well as freshly identified sequences (e.g., rellini et al., 2009; zerboni et al., 2015; frigerio et al., 2017). moreover, in a region the po plain foredeep of moderate seismicity loess is a stratigraphic marker of increasing interest for earthquake hazard characterization (e.g., livio et al., 2014). to provide the necessary spatial context for these tasks, a systematic mapping of loess outcrops along the po plain is on-going and preliminary results are here discussed. 2. the po plain loess basin loess is a wind-blown, mainly silty-sized sediment. it is widespread in northern italy, where it is typical of glacial periods, when sediment grinding (weathering), transportation, and sedimentation are enhanced by dry environmental conditions with poor vegetation cover and characterized by strong winds (cremaschi, 1990; orombelli, 1990; pye, 1995). except for a few thick sequences of unweathered loess deposits (as the val sorda sequence) and/or complex pedosequences (as at monte netto), most of the outcrops in northern italy consist of thin loess sheets located on dissected fluvial terraces, glacial deposits, uplifted isolated hills, and karst plateaus (fig. 1). these are for the most part set along the southern margin of the alps and the northern margin of the apennines. loess sequences can also be found on top of polygenetic paleosols, inside sinkholes, and intercalated in rock-shelter deposits. furthermore, loess deposits in northern italy are often associated with middle palaeolithic archaeohttps://doi.org/10.26382/aiqua.2018.aiquaconference logical sites, showing that the po plain loess basin (pplb) was a suitable environment for mousterian hunter-gatherers. available chronology, based on a number of radiocarbon, tl, and osl dating suggests that the formation of loess occurred during the upper pleistocene, between at least 75 and 16 ka bp (mis 4-2) (cremaschi, 2004; zerboni et al., 2015). thicker sequences (as at ghiardo and monte netto sites) also record weak to moderate soil-forming processes dating to the upper pleistocene interstadials and the holocene. at many sites, the uppermost part of loess sequences likely underwent moderate to strong reworking due to post-last glacial maximum (post-lgm) reactivation of slope processes, enhanced holocene bioturbation, and, more recently, human-induced processes (tillage). as a result, colluvial and bioturbated units/soil horizons were formed, whose 14c and osl dating provided midholocene ages that are interpreted as due respectively to the mixing of soil humic acids over a long time and rejuvenation of dose signal. this has been demonstrated at monte netto and ghiardo sequences (cremaschi et al., 2015; zerboni et al., 2015). 3. drawing the loess map the available geological maps present loess deposits only fragmentarily, as layers inside or at the top of quaternary formations, without providing any information on the sedimentary and post-sedimentary (pedogenetic) processes affecting loess covers. on the other hand, the available pedological maps suggest the occurrence of silt-bearing soil horizons, but interpretations of sedimentary processes ruling the accretion of silt are lacking. a few attempts to reconstruct the spatial distribution of loess in the pplb have been preliminary published by cremaschi (2004), cremaschi et al. (2015), zerboni et al. (2015); moreover, the climex map 254 fig. 1 some loess outcrops investigated in the last few years. a) the val sorda sequence (cavaion veronese, vr): loess lies on a glacial deposit. b) loess at the margin of the apennine (cavriago, re) (cremaschi et al., 2015). c) the monte netto (capriano del colle, bs) sequence (zerboni et al., 2015), displaced by an array of normal faults (i.e., gravity graben). d) loess sequence at pecetto di valenza (al) (frigerio et al., 2017). zerboni a. et al. 255 of the lgm (vai & cantelli, 2004) offers a good representation of many loess outcrops. for these reasons, the publication of a new map presenting the spatial distribution of loess is necessary and relies on field surveys in key regions, integrated by observations on (i) geological contexts and (ii) active and inactive surface processes. at the first stage, we will identify and study landforms acting as sedimentary traps for loess aggradation (cremaschi, 2004), such as: (i) glacial sediments (moraines) and fluvioglacial deposits at the southern fringe of the pre-alps; (ii) karst plateaus (and sinkholes) between lombardia and the dalmatian coast, and in the conero promontory (marche region); (iii) isolated hills in the middle of the po plain, actively growing through repeated coseismic uplift during the late quaternary; (iv) fluvial terraces of different ages on the apennine foothills between southern piemonte, emilia romagna and marche regions; (v) glacis and erosional surfaces in the apennine range of marche, emilia romagna, and liguria regions, where sedimentation can be influenced by the pre-existing topography. in the map, loess outcrops will be represented distinguishing between: (i) unweathered loess; (ii) weathered loess and loessial soils displaying different degrees of weathering and characterized by distinctive soil-forming processes; and (iii) colluvial/reworked loessic sediments (loess derivates). at a second stage, a more detailed classification of loess units will be under evaluation. this will offer a better comprehensive palaeoenvironmental context in the light of the maximum expansion of alpine and apennine glaciers and the shoreline of the adriatic sea during the lgm, which will be included in our map as reconstructed in the climex map (vai & cantelli, 2004). 4. preliminary conclusions because loess deposits in northern italy are generally thin and can be easily affected by soil-forming processes, sometimes their characteristics do not fully meet the standard requirements generally accepted for classical loess (haase et al., 2007). although loess deposits and loessial soils in the po plain are slightly different, the main sedimentological and pedological characteristics are similar in their field appearance, particle size distribution, and mineralogy, thus suggesting a similar source. the source area was identified as the po flood plain, which was exposed during glacial periods and was subject to intense winds at that time. the investigation of several key sequences and the systematic mapping of outcrops are demonstrating the importance of north italian loess for the reconstruction of upper pleistocene palaeoclimates of the northern mediterranean region and the paleoseismic record of the po plain foredeep. acknowledgements this research has been carried out within the activities of the inqua geodust international focus group. financial support from università degli studi di milano, progetto linea 2 (2016 and 2017) entrusted to az. references amit r., zerboni a. (2013) report on the inquaaeomed field-trip workshop ‘reconsidering loess in northern italy’ (po plain, 1–3 july 2013). alpine and mediterranean quaternary, 26, xi-xv. bertran p., liard m., sitzia l., tissoux h. (2016) a map of pleistocene aeolian deposits in western europe, with special emphasis on france. journal of quaternary science, 31, 844-856. coudé-gaussen g. (1990) the loess and loess-like deposits along the sides of the western mediterranean sea: genetic and palaeoclimatic significance. quaternary international, 5, 1-8. cremaschi m. (1987) loess deposits of the plain of the po and of the adjoining adriatic basin (northern italy). in: pecsi m., french h.m. (eds.), loess and periglacial phenomena. akademiai kiado, budapest, hungatia, 125-140. cremaschi m. (1990) the loess in northern and central italy: a loess basin between the alps and the mediterranean sea. c.n.r., centro di studio per la stratigrafia e petrografia delle alpi centrale, milano, italy, pp. 187. cremaschi m. (2004) late pleistocene loess. in: antonioli f., vai g.b. (eds.), litho-palaeoenvironmental maps of italy during the last two climatic extremes. climex maps italy, museo geologico giovanni cappellini, bologna, italy, 34-37. cremaschi m., zerboni a. (2016) la questione dell’apparato morenico del garda alla luce delle recenti ricerche sul torrion della val sorda. geologia insubrica, 12/1, 103. cremaschi m., zerboni a., nicosia c., negrino f., rodnight h., spötl c. (2015) age, soil-forming processes, and archaeology of the loess deposits at the apennine margin of the po plain (northern italy): new insights from the ghiardo area. quaternary international, 376, 173-188. ferraro f. (2009) age, sedimentation, and soil formation in the val sorda loess sequence, northern italy. quaternary international, 204, 54-64. frigerio c., bonadeo l., zerboni a., livio f., ferrario m.f., fioraso g., irace a., brunamonte f., michetti a.m. (2017) first evidence for late pleistocene to holocene earthquake surface faulting in the eastern monferrato arc (northern italy): geology, pedostratigraphy and structural study of the pecetto di valenza site. quaternary international, 451, 143164. haase d., fink j., haase g., ruske r., pécsi m., richter h., altermann m., jager k.d. (2007) loess in europe its spatial distribution based on a european loess map, scale 1:2,500,000. quaternary science reviews, 26, 1301-1312. lindner h., lehmkuhl f., zeeden c. (2017) spatial loess distribution in the eastern carpathian basin: a novel approach based on geoscientific maps and data. journal of maps, 13, 173-181. mapping the po plain loess basin livio f., berlusconi a., zerboni a., trombino l., sileo g., michetti a.m., rodnight h., spötl c. (2014) progressive offset and surface deformation along a seismogenic blind thrust in the po plain foredeep (southern alps, northern italy). journal of geophysical research: solid earth, 119, 7701-7721. orombelli g. (1990) loess in italy: an introduction. in: cremaschi, m. (ed.), the loess in northern and central italy: a loess basin between the alps and the mediterranean sea. c.n.r., centro di studio per la stratigrafia e petrografia delle alpi centrale, milano, italy, 11-12. pye k. (1995) the nature, origin and accumulation of loess. quaternary science reviews, 14, 653-667. rellini i., trombino l., firpo m., rossi p.m. (2009) extending westward the loess basin between the alps and the mediterranean region: micromorphological and mineralogical evidences from the slope of the ligurian alps (northern italy). geografia fisica e dinamica quaternaria, 32, 103116. smalley i.j., leach a.j. (1978) the origin and distribution of the loess in the danube basin and associated regions of east-central europe a review. sedimentary geology, 21, 1-26. vai g.b., cantelli l. (2004) litho-palaeoenvironmental maps of italy during the last two climatic extremes, map 1 last glacial maximum, map 2 holocene climatic optimum, 1:1,000,000 scale, 32nd igc florence 2004, museo geologico giovanni cappellini, bologna. wacha l., pavlakovic s.m., novothny a., crnjakovic m., frechen m. (2011) luminescence dating of upper pleistocene loess from the island of susak in croatia. quaternary international, 234, 50-61. zerboni a., trombino l., frigerio c., livio f., berlusconi a., michetti a.m., rodnight h., spötl c. (2015) the loess-paleosol sequence at monte netto: a record of climate change in the upper pleistocene of the central po plain, northern italy. journal of soils and sediments, 15, 1329-1350. 256 zerboni a. et al. ms. received: may 4, 2018 final text received: may 14, 2018 available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 34 (1), 2021, 165-180 the fossilization of mammal bones at la polledrara di cecanibbio (rome, central italy). insights for in situ preservation. federica marano1, maria rita palombo2, eugenio cerilli3, salvatore milli4,2 1 palaeontologist freelance, roma, italy. 2 cnr-igag, istituto di geologia ambientale e geoingegneria, monterotondo, italy. 3 archaeozoologist freelance, roma, italy. 4dipartimento di scienze della terra, sapienza università di roma, italy. corresponding author: federica marano <federica.marano86@gmail.com> abstract: the identification of mineralogical and chemical composition of the fossil bones is essential for reconstructing the depositional paleo-environment and burial processes, and to highlight the mechanisms triggering the fossilization processes during diagenesis. at la polledrara di cecanibbio, (the richest middle pleistocene paleontological and archaeological deposit in central italy), a museum exhibits in situ thousands of fossils deposited into a fluvial and fluvio-palustrine environment during marine isotope stage 9. the aim of this research is to disentangling between the chemical modifications undergone by the bone tissues of la polledrara di cecanibbio mammal remains exposed in situ to environmental agents on the excavated surface and those undergone by bones kept or displayed in museums. x-ray diffraction (xrd), raman spectroscopy and sem-eds analyses were carried out to establish the chemical composition of fossil bones and the alteration occurred over time. to estimate the trend of the environmental parameters inside the museum, the measures of the temperature, the relative humidity and the dew point were recorded during at least three seasons. fluoroapatite is the principal mineral phase identified in the fossils, testifying that the fluoritisation of the hydroxylapatite is the main fossilization process at la polledrara di cecanibbio. barite and gypsum are also present, in response to ground water qualities and geochemistry of the depositional and burial environment. in addition, efflorescences of gypsum crystals have been detected on the surface of fossil bones. the research performed at la polledrara di cecanibbio suggests that the crystallization of secondary minerals such as gypsum crystals depends on environmental conditions and the high solubility of this salt coupled with the facility of expansion upon its re-precipitation inside the bone tissues, constitute the main cause of deterioration. therefore, the monitoring and stabilization of the indoor environmental parameters are essential for identifying the degradation potential factors and process of bone degradation. they represent the best protocol to follow for preserving in situ fossil bones. keywords: palaeoloxodon, fossilization, preservation, geosite, cultural heritages. 1. introduction the determination of the chemical characteristics of bone and soft tissues of vertebrate remains retrieved from archaeological and palaeontological deposits could provide multiple clues in determining the biological aspect of animal life, the environments they inhabited, the impact due to human presence and anthropogenic activities, as well as the biostratinomic and diagenetic processes leading to their burial and fossilization (lee-thorp, 2002; trueman & tuross, 2002; berna et al., 2004; trueman et al., 2004; kohn & law, 2006; clementz, 2012; keenan et al., 2015; jaouen & pons, 2017; silaev et al., 2017; decrée et al., 2018; ma et al., 2019; diana et al., 2020; manthi et al., 2020; and references therein). the bone tissue is constituted by organic and inorganic components, primarily hydroxylapatite [ca10-x(po4)6x(hpo4)x(oh)2-x, following winand (1961) or ca10-x-y (hpo4)x(po4)6-x(oh)2-x-2y, following kühl & nebergall (1963); where x (0 ≤ x ≤ 2) and y depend on different environmental and biological factors (rollin-martinet et al., 2013; combes et al., 2016)] and, secondarily, calcium and phosphate salts (e.g., eliott, 2002). the bones are continuously altered over time, during the animal life, but especially after the death and the eventual burial of their skeletal system. alterations occur at different scales: molecular loss, chemical substitution, elemental enrichment, crystallite reorganization, porosity and microstructural changes, which may lead to the destruction of the entire skeleton (nielsen-marsh & hedges, 2000; jaouen, 2018). it is known that during the fossilization of bone tissues, the intra-bone porosity changes continuously with the degradation of biological material (decrée et al., 2017) and several changes in hydroxylapatite mineral structure, composition, and lattice configuration may occur (keenan et al., 2015; keenan, 2016). these changes often depend on the depositional context, especially as regards to the https://doi.org/10.26382/amq.2021.11 166 marano f. et al. alterations generated in the period during which they remained exposed to the environmental agents on the depositional surface after being unearthed. 1.1. the site: a synthetic overview the site of la polledrara di cecanibbio (hereinafter lpc) is located about 22 kilometers north-west of rome in the western sector of the roman basin, an area geologically characterised by a widespread volcanic and moderate tectonic activity and interested by the effect of quaternary glacio-eustatic sea-level fluctuations (see milli et al., 2011 and references therein) (fig.1). the fossiliferous deposit was discovered in 1984. the excavation activity, developed between 1985 and 2013 with the financial support of the soprintendenza speciale archeologia belle arti e paesaggio di roma (ssabp-rm), uncovered an area of about 1200 square meters mainly consisting in a riverbed, cut into a bank of compact volcaniclastic deposits (anzidei et al., 2012; castorina et al., 2015; santucci et al., 2016). in 2000, a museum, covering an area of about 900 sq. m, was built thanks to a grant by ministero della cultura with the aim to preserve the deposit and its archaeopalaeontological record (figs. 2-3). the mammal remains are imbedded in fluvial and fluvio-palustrine deposits belonging to the informal lithostratigraphic units known in literature as aurelia formation (conato et al., 1980). such deposits constitute the filling of an incised valley formed during the sea-level fall following mis 10. at lpc the fluvial and fluvio-palustrine sediments deposited during the vertical aggradation phase characterizing the sea-level rise that marks the transition to mis 9 (anzidei et al., 2012; santucci et al., 2016; cerilli & fiore, 2018). pereira et al. (2017) recently refined the 40ar/39ar and esr/u-series age for la polledrara fossiliferous layers to 325 ± 6 ka confirming the chronology already suggested by anzidei et al. (2012). the fauna, consisting in more than 20,000 skeletal characteristics (hydrological, geochemical, and mineralogical) of sediments within which the bones are buried, and circulating fluids (pate et al., 1989; nielsen-marsh & hedges, 2000; berna et al., 2004; trueman et al., 2004; suarez & passey, 2014; suarez & kohn, 2019). apatite crystals usually change (berna et al., 2004; trueman et al., 2004), and in the early stages of the fossilization process the carbonated hydroxylapatite is generally transformed in carbonated fluorapatite (trueman et al., 2004; thomas et al., 2007, 2011; pasteris & ding, 2009). the fossilized bone tissue is often enriched in fluorine (f), iron (fe), manganese (mn), strontium (sr), barium (ba) and rare earth elements (ree) in different quantities, because of the exchange of ca2+ cations with monovalent to hexavalent cations (keenan et al., 2015, owens et al., 2019). the addition of a proton to po4 3and ohions could made the apatite lattice suitable to the substitution with co3 2-. this process may lead to the substitution of ohby fand clions, and to the formation of apatite phases enriched in fluoride and carbonate (keenan et al., 2015 and references therein). the presence of these apatite phases in the fossilized bones provides further indications of fluids movement during diagenesis and both the permineralization and impregnation processes of the skeletal remains (hubert et al., 1996). to scrutinize about the chemical characterization of fossilized bone tissues is, therefore, of pivotal importance for deciphering the past diagenetic processes and the alteration processes currently affecting the structure and chemical composition of the skeletal remains. this knowledge may give interesting hints for detecting the best strategies (including conservation and restoration protocols) to ensure their preservation over time (e.g., mallouchou et al., 2018). this research aims to disentangling between the chemical modifications undergone by the bone tissues of the fossil remains exposed in situ at the middle pleistocene site of la polledrara di cecanibbio (roma) and the fig. 1 localization of the site of la polledrara di cecanibbio (latium, italy). fossilization of bone remains at la polledrara: insights for in situ preservation fig. 2 overview on the museum's showcase of the site, seen by nw (ssabap-rm archive). fig. 3 overview on the museum's showcase of the site, seen by sw (ssabap-rm archive). 167 remains, is dominated by large mammals (anzidei et al., 2012), being bos primigenius and palaeoloxodon antiquus the most abundant species, followed by cervus elaphus. the presence of sus scrofa, stephanorhinus cf. s. hemitoechus, bubalus murrensis, equus ferus, canis lupus, vulpes vulpes, meles meles, felis silvestris, macaca sylvanus, leporidae gen. spec.indet., is documented by few remains. the remains of small mammal and birds are, however, numerous. both murids (apodemus sylvaticus, iberomys cf. i. breccensis) and arvicolids (pliomys cf. p. episcopalis, arvicola sp.) are present, and in the rich avifauna, anseriformes species prevail (monica gala personal communication). the herpethofauna is still under study. although the lack of pollen and plant fossil remains prevents any compelling reconstruction of the vegetation cover, a few hints are provided by the ecological structure of the fauna and dental microwear and isotope analysis. the landscape at lpc was probably characterized by a dense arboreal cover interspersed with open spaces in conditions of moderately humid and temperate/warmtemperate climate (filippi et al., 2001; palombo et al., 2005). the temporary attendance at the site of hominin groups is documented by the presence of hundreds of artefacts on flint pebbles and flakes (denticulates, notches, sideand end-scrapers, multiple use tools), by some tools made on elephant bones, and by several bones intentionally fractured for marrow extraction (anzidei & cerilli, 2001). lpc likely represented an attractive area as a source of food and raw material, for the hunter-gatherer groups that frequented the surrounding territory (anzidei et al., 2015). the presence of muddy, palustrine zones near to the river banks occasionally acted as traps for elephants as documented by the presence of two skeletons with zeugopodia and autopodia still in anatomical connection and in life position. a third skeleton, lying with limb bones in anatomical connection gently bent on its left side on the riverbank, is surrounded on both sides by hundreds of lithic implements, produced in situ and used for cutting soft tissue (santucci et al., 2016). available evidence indicates that at lpc human group scavenged an elephant carcass, which died from natural causes, probably after sliding on the mud-covered bank at the edge of a palustrine zone, and having been trapped in the muddy sediments of a puddle. the butchery activity on 168 marano f. et al. elephant carcass is also documented by the presence of cut marks on a bone fragments (palombo & cerilli, in press and references therein). the single human remain found to date is a deciduous second upper molar of a child, 5-10 years old (anzidei et al., 2012). the tooth has been tentatively ascribed to homo heidelbergensis, a species recorded in italy, among others, at the middle pleistocene site of ceprano (frosinone) (manzi et al., 2010; manzi, 2016; biddittu et al., 2020; buzi et al., 2021 and references therein) and to which some scholars ascribed the rich population from the well-known spanish site of sima de los huesos (atapuerca, northen spain), regarded by others as belonging to the neanderthal lineage (e.g stringer, 2012; buck & stringer, 2014; manzi, 2016; hanagraef et al., 2018; roksandic et al., 2018, 2019). 2. material and methods 2.1. material the material selected, treated and prepared for the multidisciplinary analysis consists of eleven samples of one sedimentary nodule and 10 bone fragments collected from the surface of the riverbed (tab. 1). the samples were selected taking into account the time of the exposure: i.e. all samples belong to fossil bones or fragments exposed for more than 10 years at the site. the exposed surface of the bones, and both the cortical and the inner portion of the samples were analyzed by means of the following techniques. 2.1. methods 2.2.1. indoor environmental parameters the knowledge of the indoor environmental parameters is of fundamental importance for understanding the ongoing alteration processes affecting the fossil bones and preserving them over time. we have hourly recorded the main environmental parameters [temperature (°c), relative humidity (%) and dew point (°c)] between february and april 2015 for a period of 60 days, and for 25 days in september 2015. this enables us to estimate the trend of the environmental parameters inside the museum during two seasons (late winter / early spring and the late summer). the measures have been taken with three data loggers (lascar electrontab. 1 selected fossil bone samples collected in situ and investigation techniques used. fossilization of bone remains at la polledrara: insights for in situ preservation 169 ics, el-usb-1hdt-250, thermosense, uk) positioned in three different zones (a-b-c) of the paleo-riverbed. the selected areas are located along the northern wall (a and b), and in a central part (area c) of the museum (square m14) (fig. 4). information about the humidity and temperature trends throughout time has been inferred by means of the average daily collected data. 2.2.2. x-ray diffraction analysis (xrd) the xrd allows defining the main mineral phases composing the fossil bones. the analysis was carried out on a sample obtained 1 cm below the exposed surface and prepared by grinding the bone in a mortar to obtain a fine powder. two samples (pdc 4 and pdc 5) were powered-xrd analysed in the aim of defining the main mineralogical phases of the fossil bones. pdc4 and pdc5 consist respectively of a thin exfoliated portion and a bone carrot extracted by means of a cup with a diameter of 2.5 cm, both obtained from large mammal (bovid or elephant) bone fragments. in pdc5 only the innermost portion was preserved because the coring damaged the cortical portion that was not analysed. the analysis was conducted at x-ray powered diffraction laboratory of dipartimento di scienze della terra, sapienza università di roma by means of the automatic diffractometer siemens/bruker d-5000 xrd at 40 kv and 30 ma with an acquisition step of 2.0 seconds each 0.2 degrees. the interpretation and the identification of the mineral phases were based on the database of xpower12 ver.01.02. 2.2.3. raman spectroscopy analysis raman spectroscopy analysis (sers: confocal and surface-enhanced raman spectroscopy, and ters: tipenhanced raman spectroscopy) consists of powerful techniques for molecular characterization, and it is a very promising method for studying complex biological systems (ferraro et al., 2003; zong et al., 2018; kumar et al., 2019). qualitative and quantitative analyses constitute two of the most important aspects of sers application in analytical science (zong et al, 2018), and represent a compelling integration to other analytical methodologies. the measurements were carried out with a horiba™ labram hr evolution confocal raman microscope in back scattering geometry. samples were excited by the 632.8 nm radiation of a he-ne laser with 30 mw output power (15 mw on the sample). the detected peaks have been compared with rruff™ project database (rruff.info) and elaborated with origin software by originlab©. the technique does not require a specific preparation of the samples. the raman spettroscopy was applied on samples pdc 6, 7b and 8 in order to integrate the xrd dates by determining the mineralogical composition over a micrometric scale, and ascertaining the ionic substitutions in the original bone mineral structure during the burial. pdc6 is a p. antiquus maxillary fragment. pdc7b is a transverse section of a p. antiquus rib, obtained cutting the bone with a saw. pdc7b was analysed by means of a spectroscopic map carried out from the exposed surface towards the lymphatic canal of the osteon. pdc8 is an exfoliated portion sampled from a long bone fragment of an unidentified large mammal. 2.2.4. sem-eds analysis scanning electron microscopy with energy dispersive x-ray spectrometry (sem/eds) is an elemental microanalysis technique widely applied in physical and biological sciences, engineering, technology, and forensic investigations (goldstein et al., 2018). at lpc, semeds analysis was carried out on samples pdc 1, pdc 2, pdc 3 pdc 7a, pdc 9 and pdc10 for providing the elemental composition of a selected area of the bone sample and obtaining, thanks to high resolution images, information about the structure of bone tissue and the general physical characteristics. the samples were collected from two long bone fragments (pdc 1, pdc 9), rib fragment (pdc 7a), and an unspecified fragment (pdc fig. 4 a) plan of the excavation with the localization of monitored areas; double square represents the museum walls. b) a panoramic view of the northern sector of the exposed paleosurface; the red arrows indicate the monitored areas a and b. c) monitored area b: view of the exposed and sampled bones. d) monitored area a: view of the exposed and sampled bones. 2) of p. antiquus, from a horn-core fragment of b. primigenius (pdc 3), and from a sedimentary nodule (pdc10) (tab 1). the samples were obtained by extracting small fragments of the bone cortical portion by means of a small chisel and a hammer, except for pdc 7a from which a thin cross-section was obtained. the analyses were conducted mainly on the exposed surface of the bone, except for pdc2 and pdc7a where the inner portion was analyzed. the bone samples were fixed on stabs of 1 cm diameter and coated with a thin layer of graphite or gold and analyzed in a vacuum chamber. the acquisitions were conducted in low vacuum with different parameters of pressure, magnification and work distance, depending on the samples. the samples were analyzed at the laboratory of electron microscopy and micro-analyses of the dipartimento di scienze della terra, sapienza università di roma, by means of a scanning electron microscope thermo fisher scientific™ fei quanta™ 400. 3. results 3.1. indoor environmental parameters the values of temperature (°c) and relative humidity (%) measured during the end of winter to the beginning of spring and the late summer highlight a similar trend of the average temperature in the three monitored areas (a, b, c), though the daily values change considerably from an area to another. the highest and lowest temperatures were recorded in the area c (located in central part of the museum) and b (located near the northern wall of the museum) respectively. in the area a (located close to the windows is exposed to the sun in the first part of the day) the values of temperature are halfway. as expected, the temperatures recorded during the day and the night differ considerably. in the area a, the average temperature varies from 11°c in february to 21.2°c in september, with a minimum and maximum value of 8.5°c and 13.5°c in february and 17.5°c and 26°c in september. in the area b, the average temperature varies from 10.6°c in february to 20.7°c in september, with a minimum and maximum value of 8.5°c and 12.5°c in february and 17.5°c and 25.5°c in september. in the area c, the average temperature varies from 11.4°c in february to 21.8°c in september, with a minimum and maximum value of between 9°c and 14°c in february and 18.5°c and 26.5°c in september. conversely, the average daily relative humidity does not substantially differ in the areas a and b, while the area c is drier. in the area a, the average relative humidity varies from 96% in february to 95.8%° in september, with a minimum and maximum value of 80% and 100% in february and of 84.5% and 100% in september. in the area b, the average relative humidity varies from 95.6% in february to 97.7% in september, with a minimum and maximum value of 80.5% and 100% in february and 86% and 100% in september. in the area c, the average relative humidity varies from 92.2% in february to 89.1% in september, with a minimum and maximum value of 77.5% and 97% in february and 82.5% and 93% in september (tab 2). the higher relative humidity in the area a and b likely depends on their temperature variations, which often intercept the dew point line. as a result, the air approaches the saturation point and the water availability increase. in the area c, where the temperatures are always higher than the dew point, the availability of water is virtually nothing (fig. 5). 3.2. mineralogical and chemical composition 3.2.1. xrd analysis the xrd analysis enables us to identify the main mineral phases characterizing the samples pdc4 and pdc5. in pdc4, three mineral phases have been identified: fluoroapatite (ca10(po4)6f2 according to leroy and bres, 2001), gypsum-calcium (caso4) and a sorosilicate mainly composed of ba, which respectively correspond to three peaks of decreasing intensity in the spectrum (fig. 6a). the xrd spectrum of the samples pdc5 is characterized by two main mineral phases identified as fluorapatite and barite (baso4) (fig. 6b). 3.2.2. raman spectroscopy as regards raman spectroscopy, two different acquisition point (pt1 and pt2) were detected on sample pdc8 showing a main frequency of the po4 3site at 960 cm-1 as typical of apatite group ca5(po4)3[f, oh, cl]. the raman spectrum of the pt2 shows another spectral structure corresponding to 600 cm-1 referred to magnesioferrite mineral. moreover, the peaks of 960 cm-1 are lightly blue-shifted reaching a frequency of 964,0 +0,2 cm-1 and the fwhm (full width at half maximum height) at 10,5 + -0,2 cm-1. according to rruff™ project database (rruff.info) it is reliable to attribute the peaks to the fluoroapatite, confirming as detected by xrd. the colored thermal scale obtained by spectroscopic map carried out on 170 marano f. et al. tab. 2 environmental parameters monitored at the site during the months of february, march, april and september 2015 in the areas a, b and c. min, mean and max values of the temperature (t °c), relative humidity (rh %) and dew point (dp ° c) are reported. the sample pdc7b shows a uniform intensity signal of the peak at 960 cm-1 in correspondence of osteon. 3.2.3. sem-eds analysis the results obtained by sem eds analysis highlight a permineralization of sulfates crystals impregnating the bone tissue and sometimes incrusting the bone surface. in the sample pdc1, the external surface of the analyzed fossil bones rough, compact and, locally slightly fractured. the elemental peaks detected by eds, revealed a main composition in phosphorus (p) and calcium (ca), as it typically occurs in bone apatite (fig. 7). other accessory peaks such as silicon (si), aluminum (al), magnesium (mg), and fluorine (f) have also been detected. in sample pdc3 and pdc9, the surface of the bone is characterized by the presence of crystals composed mainly by sulphur fig. 5 trend of daily temperature (t °c), relative humidity (rh %) and dew point (dp °c) maximum (yellow line), medium (red line), and minimum (blue line), monitored in areas a, b and c during the months of february, march, april and september 2015. fossilization of bone remains at la polledrara: insights for in situ preservation 171 fig. 6 a) x-ray powered diffraction spectrum of the sample pdc4, two main peaks have been recognized: fluoroapatite (red), and gypsum (blue); b) x-ray powered diffraction spectrum of the sample pdc5 where two main peaks have been recognized: barite (green) and fluoroapatite (red). 172 marano f. et al. fig. 7 a) gypsum efflorescence on p. antiquus diaphysis exposed in situ where the sample pdc1 was collected from; b) sem image at 1500 magnification of sample pdc1, the squares a, b and c represent the point where the elemental analyses with eds has been conducted; c) the eds spot at the point a, corresponding to the bone surface, is characterized by typical peaks of the apatite with elemental composition in calcium (c) and phosphorus (p); d) the eds spot at the points b and c, corresponding to whitish efflorescence visible on the exposed bone, where the main elemental peaks are sulphur (s) and calcium (ca). (s) and calcium (ca) in addition to the p and ca peaks (fig. 8). in the sections (samples pdc2 and pdc7a), observed transversally from the cortical surface of the bone toward the inner portion, a compact structure of the bone with some fractures has been observed and the osteons and lymphatic canals have been recognized. in pdc2, some canals are not empty but filled with several prismatic and sometime tabular crystals (fig. 9). in pdc7a, most of the haversian canal situated in the portion of the sample corresponding to the bone part lying on the riverbed, and the main bone fractures are filled with tabular crystals (fig. 10a). in both samples the crystals grow usually in a definite and oriented direction and are composed by barium (ba) and sulphur (s) (figs. 9d and 10de). in all eds spots, the ba shows three peaks (α, β and γ) indicating the presence of its complete phase (figs 9e and 10f). the association of the elements we have found suggests the presence of barium sulphate or barite (baso4). in the sedimentary nodule pdc10, the internal part is characterized by euhedral tabular and elongated crystals of barite (fig. 11). 4. discussion 4.1. indoor environmental parameters the alteration processes affecting the fossil bones at lpc (especially the dissolution and re-precipitation of sulphates) mainly depend on the notable seasonal changes and intense thermal daily excursion of the indoor environmental parameters (temperature and humidity). the humidity at the site is mainly related to the water that during the rainy period, due to capillarity action in the porous volcanic sediments, makes the paleo-riverbed moist. on the one hand, the enriched water availability on both sediment and bone surfaces activates the crystallization-dissolution cycles of salts, gypsum in particular. on the other hand, during drought period, the increasing in dryness could cause mechanical damages, sometimes confused with modifications caused by diagenetic process. salts precipitation happened due to thermohygrometric factors provokes, indeed, to fossil bones a number of damages (even on a very small scale) such as fractures, crumbling of the exposed surface, erosion and disintegration (benavente et al., 2011). therefore, it is probable that the gypsum detected in the bones at lpc is due to its facility of precipitation in the fractures of diagenetic origin and induced by cracks derived from dissolution-recrystallization cycles. it could be also hypothesized that the precipitation of barium salt (barite) inside the bone fractures and cavities (though occurring at a different time and with a different pace) may be triggered by the alternating environmental conditions at the site. the environmental conditions recorded at lpc also cause the growth of photosynthetic biofilm both on sediments and the fossil bone surface, especially where there is water availability, producing at first aesthetic detrimental effects. marano et al. (2016) documented the presence of a number of associated microorganisms such as algae, fungi and mosses. in particular the authors focused the attention on cyanobacteria belonging to the genus leptolyngbya, which colonizes and grows on the exposed surface of the fossil bones at lpc. the endolitic power of the representatives this genus have been documented as regards to the deterioration of marble, façade, limestone monuments and roman catacombs (tomaselli et al., 2000; miller et al., 2009; bruno & valle, 2017; gallego-cartagena et al., 2020), and can be also hypothesized for the fossils of lpc. the chemical composition, the roughness of the surface, the porosity and the texture of the substrata are discriminating factors that control the bioreceptivity of the material (korkang & savran, 2015). the elements composing the bone substrata are mainly p and ca, but also other elements, such as potassium, sulphur, iron and magnesium have been detected by eds analysis. these are the essential trophic elements for the growth of cyanobacteria and algae. moreover the presence of gypsum as component of saline efflorescence could increase the trophic system and can be used by cyanobacteria as sulfate source (vijayakumar, 2014), increasing the damage risk for la polledrara bones. 4.2. mineralogical and chemical composition the identification of mineralogical and chemical composition of fossil bones has a pivotal importance for proper understanding of the biostratinomic processes and the diagenetic mechanisms leading to the preservation of vertebrate remains in their deposition context, (trueman et al., 2004; mclaughlin & lendev, 2011; piga et al., 2011 and reference therein; thomas et al., 2011). similarly, it is crucial to ascertain to which extend environmental physical and biotic factor may affect the status of fossil bones if they are displayed in situ, on the surface of the sediment they were retrieved from. knowing past and ongoing processes of bone modifications enable planning the correct procedures to avoid and limit any potential deterioration process. the deterioration processes may be caused by several factors, most related to the environmental parameters, such as temperature and humidity, and their instability. available evidence confirms, indeed, that water and light are among the main factors causing deterioration of palaeontological and archaeological material exposed to environmental agents (caneva & ceschin, 2007). several authors consider the process of fluoritisation of the hydroxylapatite (i.e. the replacement of ohions by fion), directly related to the neighboring environment fig. 8 a) bos primigenius horn exposed in situ where the sample pdc3 was collected from, the fossil is characterized by salts efflorescence causing exfoliation and disintegration; b) sem image at the 2800 magnification of the sample pdc3, the crystal clusters are characterized by rose-like shape as typical of gypsum crystals; c) the eds elemental spot showing the composition of the crystals in ca and s ascribed to calcium sulphate (gypsum). fossilization of bone remains at la polledrara: insights for in situ preservation 173 174 marano f. et al. fig. 9 -sem-eds images of barium sulphate crystals found during the observation of the cortical portion of the fossils (pdc2), x corresponds to detected points: a, b and c) sem images at 1600 magnification showing fractures and channels filled with barite euhedral tabular crystals; d) sem image at 3000 magnification with barite crystals growing in a channel; e) eds spot conducted on crystals showing all peak of ba and s. fossilization of bone remains at la polledrara: insights for in situ preservation fig. 10 sem-eds images of the thin transversal section (pdc7a) obtained from an elephant rib. the section is oriented: the upper part corresponds to the exposed surface while the lower portion lay on the paleo riverbed. a) the section at 50 magnifications shows the internal structure with the osteons and haversian canals, a series of main fractures are visible running from the top to the bottom of the sample and transversally specially in uppermost portion, micro fractures are also present on entire surface of the sample; b, c) some of the biggest fractures and some osteons at the bottom of the sample appear filled with crystal that give a white fluorescence; d) the big fracture crossing the whole section where euhedral crystals are growing upward; f) eds spot detected on crystals filling the fractures and haversian channels showing all peaks of ba and s. 175 characteristics (leroy & bress, 2001; thomas et al., 2007, 2011) and the most frequent process of substitution undergone by the biogenic apatite (piga et al., 2009, 2011). arnoldus & anzidei (1993) and arnoldus et al. (2001), detecting the presence of the gypsum (caso4) and barite (baso4) only in sediments, hypothesized that the process of fossilization of the lpc bones may have triggered by their indirect contact with ashes and fluorinecontaining water. the presence at lpc of fluorine in the fossil bones and in a number of the abundant centimetric nodules present in sediments filling the paleo-riverbed (particularly near the river bottom) is in agreement with the high content of ba detected as trace element in the uppermost sediments of the local stratigraphic section (castorina et al., 2015). a high concentration of ba forming barium sulfate minerals has been reported in some fluorine deposits cropping out in northern latium, but its origin and genesis are still a matter of debate (matteucci, 1976; di sabatino et al., 1979; de rita et al., 2012). several deposits of barite and other sulfates such as celestine (srso4) have been recognized and described in territories surrounding the lpc area (barbieri & masi, 1978). mastrangelo (1976), for instance, described some fluoride deposits enriched in barite minerals at valle santa, a locality few kilometers north to lpc. the same deposits are correlated by arnoldus & anzidei (1993) with the fluoride whitish layers outcropping near la polledrara fossiliferous deposit. trueman et al. (2004) detected the presence of barite as the second most abundant authigenic mineral, formed in situ in response to the geochemical process in several recent bones exposed during a time of 26 years in the tropical savannah environment of amboseli national park. the presence of barite crystals concentrated in the most external osteon cavities suggests a fast precipitation of the mineral in response to the circulation features of the ground water and the elements dissolved in it. scrutinizing processes leading to the presence of ba may provide some clues about the hydrochemistry characteristics of a terrestrial environment during the animal life (brügmann et al., 2012; hanor, 2000). merk et al. (2017), for instance, aiming at scrutinizing the biomineralization processes in the plant kingdom, experimented how the baso4 organizes the crystals in a wood structure. the authors obtained an oriented growth of baso4 crystals confined in the complex and highly directional cell architecture of wood, highlighting a prevalent and fast crystallization of baso4 at different hierarchical levels in the cavities. at lpc, the presence of ba forming barite crystals in the bone tissue cavities provides some hints about biostratinomic processes and the hydrochemistry characterizing the environment during the burial and fossilization phases. the presence of barium sulfate crystals, oriented in the osteonic (haversian) canal and in the main fractures, which were produced by weathering and transport before the burial, indicates that the circulation of ground waters enriched in high contents of ions ba+ and so4 2and f favored both the precipitation of barite mineral in the cavities of bone tissue and fractures and the hydroxlyapatite fluoritization process skeletal remains after their deposition and burial process. arnoldus & anzidei (2001) reported the presence of some large imprints of radial gypsum crystals in la polledrara fossiliferous sediments. they were likely originated by the chemical interaction between the bone calcium and the sulphur contained in the circulating fluids or gasses. a large amount of carbonates and sulfates, accompanied by other elements, is present both in the deep hydrothermal reservoir and in the shallower water reservoir of the sabatini volcanic district (cinti et al., 2017, 2019, and reference therein). therefore, it is rationale to suppose that both the calcium present in the bones and mainly the ca+ ions typically circulating in groundwater of the sabatini volcanic district supplied the ca+ needed for the gypsum precipitation. some gypsum crystals have also been detected on the surface of the fossil bones at lpc. their “rose-like” shape indicates a very fast precipitation, comparable with that of the whitish efflorescence that affects archaeological building stones. the gypsum efflorescence have been acknowledged to be the principal salt sulphate causing deterioration on cultural heritage (mortar, paintings, facades, hypogea environment, and building stones in general) (rodrigueznavarro & doehne, 1999; bugini et al., 2000; albertano et al., 2003; rijniers et al., 2005; cardell et al., 2008; benavente et al., 2011; lopez-arce et al., 2011; barca et al., 2014 and references therein; zammit et al., 2011) and triggering the developing of microorganisms (marano et al, 2016; lepinay et al., 2018, and reference therein; marano unpublished data). the high solubility of this salt and the facility of expansion upon its re-precipitation inside the bone structures constitute the main cause of deterioration. since the crystallization of secondary minerals such as gypsum crystals is strictly related to environmental condition and in particular to the humidity and water availability, a monitoring of the environmental conditions is of crucial important for the preservation of fossil bones whatever they are kept or displayed. fig. 11 sem images at 800 magnification of the inner portion of sedimentary nodule (pdc10) characterized by elongated, tabular and oriented crystals. ba and s characterize their elemental composition. 176 marano f. et al. 5. conclusion the identification of befitting conservation strategies is of crucial relevance especially in the case of skeletal remains preserved in situ and possibly exposed to the aggression of biotic and abiotic agents, such as humidity, temperature, sunshine, possible aggression of biological agents, particularly the growth of biofilms. the musealized portion of the la polledrara di cecanibbio fossiliferous deposit, one of the richest in p. antiquus remains and the most fascinating in italy, offered a pivotal case study for deconstructing pattern and processes of fossil bones deterioration and inferring compelling protection actions. results obtained by this study highlight the particular importance the determination of the indoor environmental parameters has for properly understanding the alteration processes in progress and disentangling the past processes related to biostratinomy and diagenesis. fluoritization was the main process occurring during the diagenetic modification of the bone remains at lpc that favored the fossilization. the presence of oriented barite crystals, detected in the main fracture and in the osteonal cavities by means of high-resolution sem images, indicates that a precipitation of sulfate salts occurred, and perhaps it is still in progress, due to the enriched fluids that grow up for capillarity during the rainy period, which favored the availability of water on the surface in some areas of the museum for most of the year. as a result, fossils continue to be wet for long time, and the precipitation and dissolution cycles of salts cause mechanical damages, chemical aggression and facilitate biological attacks. the exfoliation, erosion, powdering, dissolution and endolithic attack of the bone surface, could threaten the notable scientific value of the site, hampering the development of researches. an optimal preservation of the bone surface is, for instance, the primary requirement for detecting evidence of human butchery activity on fossil bones, particularly cut marks, but also for deepened anatomo-physiological studies. accordingly, the potential archaeological and scientific value of the palaeontological record decreases as the deterioration process increases. all in all, this research highlights the main process affecting fossil bones after they have been uncovered, and stresses how the stabilization of the indoor environmental parameters could be regards as best protocol to reduce the damage risk of exposed bones. acknowledgements we are grateful to the dott.ssa anna de santis (soprintendenza speciale archeologia belle arti e paesaggio di roma) for granting permission to carry out the research and to publish the results. we thank the teams of laboratory of geological thin sections, laboratory of x-ray powered diffraction and laboratory of electron microscopy and micro-analyses of the earth science department, sapienza university of rome. we thank the hps research group (high pressure spectroscopy) of the department of physics, sapienza university of rome. a particular thank to dr neil helwood of science department (roma 3 university) for processing the monitored environmental data. references albertano p., moscone d., palleschi g., hermosin b., saiz-jimenez c., sanchez-moral s., hernandezmarine m., urzi c., groth i., schroeckh v., saarela m., mattila-sandholm t., gallon j.r., graziottin f., bisconti f., giulian r. (2003) cyanobacteria attack rocks (cats): control and preventive strategies to avoid damage caused by cyanobacteria and associated microorganisms in roman hypogean monuments. in: saiz-jimenez, c., (ed), molecular biology and cultural heritage. swets and zeitlinger bv, lisse, 151-162. anzidei a.p., bulgarelli g.m., catalano p., cerilli e., gallotti r., lemorini c., milli s., palombo m.r., pantano w., santucci e. (2012) ongoing research at the late middle pleistocene site of la polledrara di cecanibbio (central italy), with emphasis on humanelephant relationships. quaternary international, 255, 171-187. anzidei a.p., bulgarelli g.m., cerilli e., fiore i., lemorini c., marano f., palombo m.r., santucci e. (2015) strategie di sussistenza nel paleolitico ingeriore a la polledrara di cecanibbio (roma): lo sfruttamento di una carcassa di palaeoloxodon antiquus. 50° riunione scientifica dell'istituto italiano di preistoria e protostoria "preistoria del cibo", roma 5-9 ottobre 2015, sessione 2. anzidei a.p., cerilli e. (2001) the fauna of la polledrara di cecanibbio and rebibbia-casal de’ pazzi (rome, italy) as an indicator for site formation processes in a fluvial environment. proceedings of the first international congress, the world of elephants. consiglio nazionale delle ricerche, rome, 167-171. arnoldus-huyzendveld a., anzidei a.p. (1993) ricostruzione di un ambiente fluvio palustre nella regione vulcanica di roma (la polledrara di cecanibbio). paleosuperfici del pleistocene e del primo olocene in italia processi di formazione e interpretazione. atti della xxx riunione scientifica venosa e isernia 2629 ottobre 1991, 151-165. arnoldus-huyzendveld a., zarlenga f., gioia p., palombo m.r. (2001) distribution in space and time and analysis of preservation factors of pleistocene deposits in the roman area. in: cavarretta, g., gioia, p., mussi, m., palombo, m.r. (eds.), the world of elephants. consiglio nazionale delle ricerche, rome, 10-17. barbieri m., masi u. (1978) considerazione geochimiche sull’origine del giacimento di barite e celestite di pian dell’organo (civitavecchia). società italiana di mineralogia e petrologia, 34, 161-166. barca d., comite v., belfiore c.m., bonazza a., la russa m.f., ruffolo s.a., crisci g.m, pezzino a., sabbioni c. (2014) impact of air pollution in deterioration of carbonate building materials in italian urban environments. applied geochemestry, 48, 122-131. benavente d., sanchez-moral s., fernandez-cortes a., canaveras j.c., elez j., saiz-jimenez c. (2011) salt damage and microclimate in the postumius tomb, roman necropolis of carmona, spain. environmental earth science, 63, 1529-1543. berna f., matthews a., weiner s. (2004) solubilities of fossilization of bone remains at la polledrara: insights for in situ preservation 177 isotope analysis of fossil mammals. journal of mammalogy, 93, 368-380. combes c., cazalbou s., rey c. (2016) apatite biominerals. minerals, 6, 34. decrée s., herwart, d., mercadier j., miján i., de buffrénil v., leduc t., lambert o. (2018) the post-mortem history of a bone revealed by its trace element signature: the case of a fossil whale rostrum. chemical geology, 477, 137-150. de rita d., cremisini c., cinnirella a., spaziani f. (2012) fluorine in the rocks and sediments of volcanic areas in central italy: total content, enrichment and leaching processes and a hypothesis on the vulnerability of the related aquifers. environmental monitoring and assessment, 184, 5781-5796. diana p., juha s., reinhard z., hervé b. (2020) stable isotopic and mesowear reconstructions of paleodiet and habitat of the middle and late pleistocene mammals in south-western germany. quaternary science reviews, 227, 106026. di sabatino b., barrese e., giampaolo c. (1979) sulla genesi delle fluoriti “sedimentarie” area meridionale del distretto vulcanico sabatino. rendiconti della società italiana di mineralogia e petrologia, 35 (1), 439-451. elliott j.c. (2002) calcium phosphate biominerals. reviews in mineralogy and geochemistry, 48, 427-453. ferraro j.r., nakamoto k., brown c. (2003) introductory raman spectroscopy. 2nd edition, academic press, elsevier science. filippi m.l., palombo m.r., barbieri m., capozza m., iacumin p., longinelli a. (2001) isotope and microwear analyses on teeth of late middle pleistocene elephas antiquus from the rome area (la polledrara, casal de’ pazzi). in: cavarretta c., gioia p., mussi m., palombo m.r. (eds.), proceedings of the first international congress, the world of elephants. consiglio nazionale delle ricerche, rome, 534-539. gallego-cartagena e., morillas h., maguregui m., patiñocamelo k., marcaida i., morgado-gamero w., silva l.f.o., madariaga j.m. (2020) a comprehensive study of biofilms growing on the built heritage of a caribbean industrial city in correlation with construction materials. international biodeterioration and biodegradation, 147, 104874. goldstein j.i., newbury d.e., joy d.c., lyman c.e., echlin p., lifshin e., sawyer l., michael j. (2018) scanning electron microscopy and x-ray microanalysis. 4th ed. new york: springer. doi: 10.1007/978-1-4939-6676-9 hanegraef h., martinónοtorres m., martínez de pinillos m., martínοfrancés l., vialet a., arsuaga j.l., bermúdez de castro j.m. (2018) dentine morphology of atapuercaοsima de los huesos lower molars: evolutionary implications through threeο dimensional geometric morphometric analysis. american journal of physical anthropology, 166(2), 276-295. hanor j.s. (2000) barite-celestine geochemistry and environments of formation. reviews in mineralogy and geochemistry, 40, 193-275. bone mineral from archaeological sites: the recrystallization window. journal of archaeological science, 31, 867-882. biddittu i., moncel m.h., milli s., bellucci l., ruffo m., saracino b., manzi g. (2020) stratigraphy, sedimentology, and archaeology of middle pleistocene localities near ceprano, campogrande area, italy. quaternary research 93, 155-171. brugmann g., krause j., brachert t.c., kullme, o., schrenk f., ssemmanda i., mertz1 d.f. (2012) chemical composition of modern and fossil hippopotamid teeth and implications for paleoenvironmental reconstructions and enamel formation part 1: major and minor element variation. biogeosciences, 9, 119 -139. bruno l., valle v. (2017) effect of white and monochromatic lights on cyanobacteria and biofilms from roman catacombs. international biodeterioration and biodegradation, 123, 286-295. buck l.t., stringer c.b. (2014) homo heidelbergensis. current biology, 24(6), r214-r215. bugini r., laurenzi tabasso m., realini m. (2000) rate of formation of black crusts on marble. a case study. journal of cultural heritage, 1, 111-116. buzi c., di vincenzo f., profico a., manzi g. (2021) the pre-modern human fossil record in italy from the middle to the late pleistocene: an updated reappraisal. alpine and mediterranean quaternary, 34(1), 116. caneva g., ceschin s. (2007) ecologia del biodeterioramento. in: caneva, g., nugari, m.p., salvadori, o. (eds.), la biologia vegetale per i beni culturali. biodeterioramento e conservazione. nardini editore, firenze, 35-58. cardell c., benavente d., rodríguez-gordillo j. (2008) weathering of limestone building material by mixed sulfate solutions. characterization of stone microstructure, reaction products and decay forms. materials characterization, 59, 1371-1385. castorina f., masi u., milli s., anzidei a.p., bulgarelli g.m. (2015) geochemical and sr-nd isotopic characterization of middle pleistocene sediments from the paleontological site of la polledrara di cecanibbio (sabatini volcanic district, central italy). quaternary international, 357, 253-263. cerilli e., fiore i. (2018) natural and anthropic events at la polledrara di cecanibbio (italy, rome): some significant examples. alpine and mediterranean quaternary, 31, 55-58. cinti d., tassi f., procesi m., brusca l., cabassi j., capecchiacci f., delgado huertas a., galli g., grassa f., vaselli o., voltattorni n. (2017) geochemistry of hydrothermal fluids from the eastern sector of the sabatini volcanic district (central italy). applied geochemistry, 84, 187-201. cinti d., vaselli o., poncia p.p., brusca l., grassa f., procesi m., tassi f. (2019) anomalous concentration of arsenic, fluoride and radon in volcanicsedimentary aquifers from central italy: quality index for management of the water resource. environmental pollution, 253, 525-537. clementz m.t. (2012) new insight from old bones: stable 178 marano f. et al. tion, 140, 102338. manzi g. (2016) humans of the middle pleistocene: the controversial calvarium from ceprano (italy) and its significance for the origin and variability of homo heidelbergensis. quaternary international, 411, 254261. manzi g., magri d., milli s., palombo m.r., celiberti v., margari v., barbieri m., barbieri m., melis r.t., rubini m., ruffo m., saracino b., tzedakis p.c., zarattini a, biddittu i. (2010) the new chronology of the ceprano calvarium (italy). journal of human evolution, 59, 580-585. marano f., di rita f., palombo m.r., ellwood n.t.w., bruno l. (2016) a first report of biodeterioration caused by cyanobacterial biofilms of exposed fossil bones: a case study of the middle pleistocene site of la polledrara di cecanibbio (rome, italy). international biodeterioration and biodegradation, 106, 67-74. mastrangelo f. (1976) i giacimenti. rendiconti della società italiana di mineralogia e petrologia, 32, 2946. matteucci e. (1976) le fluoriti sedimentarie laziali: ipotesi e problemi genetici. rendiconti della società italiana di mineralogia e petrologia, 32, 47-63. mclaughlin g., lednev i.k. (2011) potential application of raman spectroscopy for determining burial duration of skeletal remains. analytical and bioanalytical chemistry, 401, 2511-2518. merk v., berg j.k., krywka c., burget i. (2017) oriented crystallization of barium sulfate confined in hierarchical cellular structures. crystal growth design, 17, 677-684. miller a.z., liaz l., dionisio a., macedo m.f., saizjimenez c. (2009) growth of phototrophic biofilms from limestone monuments under laboratory conditions. international biodeterioration and biodegradation, 63, 860-867. milli s., palombo m.r., anzidei a.p. (2011) i depositi pleistocenici di ponte galeria e la polledrara di cecanibbio. in: guidebook post-congress field trip. aiqua 2011 “il quaternario italiano conoscenze e prospettive”. italian association for quaternary studies, rome. february 26, pp. 37. nielsen-marsh c.m., hedges r.e. (2000) patterns of diagenesis in bone i: the effects of site environments. journal of archaeological science, 27, 11391150. owens c.l., nash g.r., hadler k., fitzpatrick r.s., anderson c.g., wall f. (2019) apatite enrichment by rare earth elements: a review of the effect s of surface properties. advances in colloid and interface science, 265, 14-28. palombo m.r., filippi m.l., iacumin p., longinelli a., barbieri m., maras a. (2005) coupling tooth microwear and stable isotope analyses for palaeodiet reconstruction: the case study of late middle pleistocene elephas (palaeoloxodon) antiquus teeth from central italy (rome area). quaternary international, 126-128, 153-170. palombo m.r., cerilli e. (in press) human-elephant interactions during the lower palaeolithic: scrutinihubert j.f., panish p.t., chure d.j., prostak k.s. (1996) chemistry, microstructure, petrology, and diagenetic model of jurassic dinosaur bones, dinosaur national monument, utah. journal of sedimentary research, 66, 531-547. jaouen k. (2018) what is our toolbox of analytical chemistry for exploring ancient hominin diets in the absence of organic preservation? quaternary science reviews, 197, 307-318. jaouen k., pons m.l. (2017) potential of non-traditional isotope studies for bioarchaeology. archaeological and anthropological sciences, 9, 1389-1404. keenan s.w., engel a.s., roy a., bovenkamp-langlois g.l. (2015) evaluating the consequences of diagenesis and fossilization on bioapatite lattice structure and composition. chemical geology, 413, 18-27. keenan s.w. (2016) from bone to fossil: a review of the diagenesis of bioapatite. american mineralogist, 101, 1943-1951. kohn m.j., law j.m. (2006) stable isotope chemistry of fossil bone as a new paleoclimate indicator. geochimica et cosmochimica acta, 70, 931-946. korkang m., savran a. (2015) impact of the surface roughness of stone used in historical buildings and biodeterioration. constructing and building materials, 80, 279-294. kühl g., nebergall w.h. (1963) hydrogenphosphatund carbonatapatite. zeitschrift für anorganische und allgemeine chemie, 324, 313-320. kumar n., weckhuysen b.m., wain a.j., pollard a.j. (2019) nanoscale chemical imaging using tipenhanced raman spectroscopy. nature protocols, 14(4), 1169-1193. lee-thorp j. (2002) two decades of progress towards understanding fossilization processes and isotopic signals in calcified tissue minerals. archaeometry, 44, 435-446. lepinay c., mihajlovski a., touron s., seyer d., bousta f., di martino p. (2018) bacterial diversity associated with saline efflorescences damaging the walls of a french decorated prehistoric cave registered as a world cultural heritage site. international biodeterioration and biodegradation, 130, 55-64. leroy n., bres e. (2001) structure and substitutions in fluorapatite. european cells and materials, 2, 36-48. lopez-arce p., fort-gonzales r., gomez-hers m., pérezmonserrat e.m., varas m.j. (2011) preservation strategies for avoidance of salt crystallization in el paular monastery cloister, madrid, spain. environmental earth sciences, 63, 1487-1509. ma j., wang y., jin c.z., zhang h.w., hu y.w. (2019) a preliminary study of serial stable isotope analysis tracks foraging ecology of fossil asian elephants in south china. vertebrata palasiatica, 57, 225-240. mallouchou m.s., stathopoulou e.t., theodorou g.e. (2018) how do fossilized mammalian bones behave during chemical conservation? the histological case studies of tilos and kerassia. geoheritage, 11, 597-614. manthi f.k., cerling t.e., chritz k.l., blumenthal s.a. (2020) diets of mammalian fossil fauna from kanapoi, northwestern kenya. journal of human evolu fossilization of bone remains at la polledrara: insights for in situ preservation 179 stringer c. (2012) the status of homo heidelbergensis (schoetensack 1908). evolutionary anthropology: issues, news, and reviews, 21(3), 101-107. suarez m.b., passey b.h. (2014) assessment of the clumped isotope composition of fossil bone carbonate as a recorder of subsurface temperatures. geochimica et cosmochimica acta, 140, 142-159. suarez c.a., kohn m.j. (2020) caught in the act: a case study on microscopic scale physicochemical effects of fossilization on stable isotopic composition of bone. geochimica et cosmochimica acta, 268, 277-295. thomas d.b., fordyce r.e., frew r.d., gordon k.c. (2007) a rapid, non-destructive method of detecting diagenetic alteration in fossil bone using raman spectroscopy. journal of raman spectroscopy, 38, 1533-1537. thomas d.b., mcgoverin c.m., fordyce r.e., frew r.d., gordon k.c. (2011) raman spectroscopy of fossil bioapatite a proxy for diagenetic alteration of the oxygen isotope composition. palaeogeography, palaeoclimatology, palaeoecology, 310, 62-70. tomaselli l., tiano p., lamenti g. (2000) occurrence and fluctuation in photosynthetic biocoenoses dwelling on stone monuments. in: ciferri o., tiano p., mastromei g. (eds), of microbes and art the role of microbial communities in the degradation and protection of cultural heritage, 63 76. new york: kluwer. trueman c.n.g., tuross n. (2002) trace elements in recent and fossil bone apatite. reviews in mineralogy and geochemistry, 48, 489-521. trueman c.n.g., behrensmeyer a.k., turos n., weiner s. (2004) mineralogical and compositional changes in bones exposed on soil surfaces in amboseli national park, kenya: diagenetic mechanisms and the role of sediment pore fluids. journal of archaeological science, 31, 721-739. vijayakumar s. (2014) role of cyanobacteria in biodeterioration of historical monuments a review. bmr microbiology, 1, 1-13. winand l. (1961) etude physico-chimique du phosphate tricalcique hydrate et de l’hydroxylapatite. annales de chimie (paris), 6, 941-967. zammit g., sanchez-moral s., albertano p. (2011) bacterially mediated mineralization processes lead to biodeterioration of artworks in maltese catacombs. science of total environment, 409, 2773-2782. zong c., xu m., xu l.j., wei t., ma x., zheng x.s., ren h., ren b. (2018) surface-enhanced raman spectroscopy for bioanalysis: reliability and challenges. chemical reviews, 118(10), 4946-4980. zing the role of environmental factors. in: harvati k konidaris g., barkai r., kießling k. (eds), the human-elephant interactions from past to present. tübingen university press (2020). pasteris j.d., ding d.y. (2009) experimental fluoridation of nanocrystalline apatite. american mineralogist, 94, 53-63. pate f.d., hutton j.t., norrish k. (1989) ionic exchange between soil solution and bone: toward a predictive model. applied geochemistry, 4, 303-316. pereira a., nomade s., faulguères c., bahain j.j., tombret o., garcia t., voichet p., bulgarelli g.m., anzidei a.p. (2017) 40ar/39ar and esr/u-series data for the la polledrara di cecanibbio archaeological site (lazio, italy). journal of archaeological science, reports, 15, 20-29. piga g., santos-cubedo a., brunetti a., piccinini m., malgosa a., napolitano e., enzo s. (2011) a multitechnique approach by xrd, xrf, ft-ir to characterize the diagenesis of dinosaur bones from spain. palaeogeography, palaeoclimatology, palaeoecology, 310, 92-107. piga g., santos-cubedo a., moya solà s., brunetti a., malgosa a., enzo s. (2009) an x-ray diffraction (xrd) and x-ray fluorescence (xrf) investigation in human and animal fossil bones from holocene to middle triassic. journal of archaeological science, 36, 1857-1868. rijniers a.l., pel l., huinink h.p., kopinga k. (2005) salt crystallization as damage mechanism in porous building materials a nuclear magnetic resonance study. magnetic resonance imaging, 23, 273-276. roksandic m., radović p., lindal j. (2018) revising the hypodigm of homo heidelbergensis: a view from the eastern mediterranean. quaternary international, 466, 66-81. roksandic m., radović p., wu x., bae c. (2019) homo heidelbergensis: what do we need to set the question of the validity of this taxon to rest. american journal of physical anthropology, 168, 207-207. rodriguez-navarro c., doehne e. (1999) salt weathering: influence of evaporation rate, supersaturation and crystallization pattern. earth surface processes and landform, 24, 191-209. rollin-martinet s., navrotsky a., champion e., grossin d., drouet c. (2013) thermodynamic basis for evolution of apatite in calcified tissues. american mineralogist, 98, 2037-2045. santucci e., marano f., cerilli e., fiore i., lemorini c., palombo m.r., anzidei a.p., bulgarelli g.m. (2016) palaeoloxodon exploitation in the late middle pleistocene site of polledrara di cecanibbio (rome, italy). quaternary international, 406, 169-182. silaev v.i., ponomarev d.v., kiseleva d.v., smoleva i.v., simakova y.s., martirosyan o. v., vasilev a., khazov f., tropnikov e.m. (2017) mineralogicalgeochemical characteristics of the bone detritus of pleistocene mammals as a source of paleontological information. paleontological journal, 51, 1395-1421. 180 marano f. et al. ms. received: 11 october, 2020 revised: 30 april, 2020 accepted: 07 may, 2021 avaiable online: 21 june, 2021 sess 1_160211.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 ms. received: testo ricevuto il a potential gssp for the upper pleistocene alessandra negri 1, fabrizio antonioli 2, lorenzo angeletti 3, stefano marabini 4, giuseppe mastronuzzi 5, paolo montagna 6, andrea piva 7, daniele scarponi 4, marco taviani 3, luigi vigliotti3 & gian battista vai4  1 universita’ politecnica delle marche, ancona (centrato, arial 10) 2 enea, casaccia, roma 3 ismar cnr, bologna 4 universita’ degli studi di bologna, bologna 5 universita’ degli studi di bari, bari 6 cnrs gif sur yvette, france 7 eni san donato milanese (mi) corresponding author: a. negri <a.negri@univpm.it> abstract: negri a. et al., a potential gssp for the upper pleistocene. (it issn 0394-3356, 2011) here we present the results of an integrated stratigraphic study performed in the taranto area for the definition of the tarentian stage for the upper pleistocene riassunto: negri a. et al., un potenziale gssp per il pleistocene superiore. (it issn 0394-3356, 2011) presentiamo i risultati dello studio di una sezione localizzata nell’area di taranto potenzialmente utile per la definizione del piano tarentiano del plestocene superiore key words:chronostratigraphy quaternary, tarentian stage parole chiave: cronostratigrafia,quaternario, piano tarentiano the importance of a well established chronostratigraphy is a starting point for the correlation of the various archives used for the reconstruction of climate, regional sea level fluctuations and tectonic movements. in this frame the italian commission on stratigraphy of the sgi is seeking for a marine section suitable for defining the upper pleistocene gssp. this series has been usually identified with the tyrrhenian stage which in the wake of formalization received different meaning from stratigraphers and geomorphologits. hence, the proposal of a new upper pleistocene stage name and type area, the tarentian, made in 1994. criteria for defining the tarentian stage and selecting its gssp can be the beginning of mis 5 ( 134 ka) and the beginning of mis 1 ( 10 ka) taken for the base of the holocene. the tarentian stage contains also mis 5.5 highstand with its peak at 125 ka. upper pleistocene marine deposits of thickness exceeding 1 to 2 m are rarely exposed on land except for some mediterranean countries. italian coastal areas keep some hundreds of marine upper pleistocene sites. they are all characterized by the so called strombus bubonius senegalese tropical fauna (persististrombus latus (gmelin, 1791) (= bubonius (lamarck, 1822). they are found at different elevations from -130 to +170 m depending on the strong differential crustal mobility of the area. the best up to some 10 m thick upper pleistocene marine sections are exposed at the coast of the gulf of taranto facing the ionian sea. here, where a well exposed marine succession has been uplifted very recently, we have explored the possibility to find a suitable gssp for the upper pleistocene adopting a combined stratigraphic approach based on litho bio and magnetotsratigraphy and corroborated by paleoecological and, u-th analyses. 44 january 13, 2011 13 gennaio 2011 microsoft word 04_mozzi_lm02.doc available online http:/amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 26 (1), 2013, 41-54 integrating digital elevation models and stratigraphic data for the reconstruction of the post-lgm unconformity in the brenta alluvial megafan (north-eastern italy) paolo mozzi1, francesco ferrarese2, alessandro fontana1 1 dipartimento di geoscienze, università degli studi di padova, italy 2 dipartimento di scienze storiche, geografiche e dell’antichità, università degli studi di padova, italy corresponding author : paolo mozzi <paolo.mozzi@unipd.it> abstract: stratigraphic cores and sections, geological maps and digital elevation models (dems) were used for the threedimensional reconstruction of a portion of the regional unconformity, which separates the last glacial maximum (lgm) sedimentary complex from the post-lgm one. the investigation focused on the brenta megafan, a ca. 3000 km2 wide alluvial system that extends from the alpine piedmont to the venice lagoon. during lgm the brenta megafan experienced a major aggradation phase, which led the system to achieve its maximum extent. fluvial downcutting started after 17.5 cal ka bp and led to the formation of incised valleys (ivs) in the plain, which reached depths up to 20-30 m. the interfluves between ivs experienced soil formation (calcisols, luvisols) until their burial by later deposits, or until present in the case of wide exposed stretches of lgm plain. a dem of the present surface of the brenta megafan and a geological map of the lgm deposits were created in a geographic information system (gis). seventeen cores and sections with information on the nature (erosive vs. hiatal with soil formation) and depth of burial of the post-lgm unconformity, as well as on the stratigraphy of the alluvial succession, were introduced in the gis as stratigraphic control points (scps). contours of the base of post-lgm sediments with 2-m interval were available in the venice lagoon and its mainland. different interpolation and statistical methods were applied for modeling the unconformity in the pedogenized interfluves and in ivs. contours were interpolated with triangulated irregular network (tin) technique. scps were interpolated with inverse distance weight (idw) algorithm with the function cos3. linear trend equations between the exposed top of the valley fill, i.e. the topographic surface in the dem, and the unconformity elevation were calculated in different reaches of ivs. data processing resulted in the production of a dem of the post-lgm unconformity in the whole brenta megafan with a cell size of 30x30 m. morphometric analysis of the dem enabled to evaluate the gradients of the unconformity in long and transverse profiles, as well as to calculate its overall extension (1491 km2), the areas characterized by buried soils (970 km2), and those which correspond to an erosive surface in ivs (521 km2). the difference between the dem of the unconformity and the present topographic surface allowed for the first calculation of the volume of alluvial and coastal sediments which lie on top of the unconformity (10.4 km3), and of those which fill the ivs (4.3 km3). the unconformity was traced and modeled across a whole range of sedimentary environments, from braided gravel-bed channel belts (in the proximal sector) down to coastal barrier-and-lagoon systems. the method may be applied to neighboring megafans of the venetian-friulian and eastern po plain. moreover, it can be extended offshore, in the shelf of northern adriatic sea, to the tip of the deltaic systems, providing a valuable tool for basin-scale stratigraphic correlations and quantitative estimation of erosive processes and sedimentary storage. keywords: last glacial maximum, unconformity, allostratigraphy, dem, alluvial megafan, venetian plain. 1. introduction an unconformity is a surface between rock bodies that represents a significant hiatus or gap in the stratigraphic succession (salvador, 1994). the importance of an unconformity is related to its geographical extent (e.g., regional-interregional traceability and/or correlatability) and the temporal interval of the stratigraphic hiatus. whilst the concept of unconformity has a long history, starting from hutton’s and jameson’s works between the end of 18th and the beginning of the 19th century (tomkeieff, 1962), the use of unconformities to formally subdivide and organize sedimentary successions has been receiving increasing attention only in more recent times. allostratigraphy has been incorporated in the north american stratigraphic code (nacsn, 1983) and the international stratigraphic guide (salvador, 1994). several state geological surveys in the usa use an allostratigraphic approach in geological mapping (e.g., mcculloh et al., 2003; heinrich et al., 2006; breckenbridge et al., 2005). the geological survey of italy has adopted unconformity-bounded stratigraphic units for the production of 1:50,000 scale geological maps (carg project) (cnr, 1992; pasquarè & venturini, 2005). the strength and weakness of allostratigraphy vs. lithostratigraphy or morphostratigraphy in subdiving quaternary continental successions have been widely debated (e.g. gibbard, 1985; rawson et al., 2002; hughes, 2007, 2010; räsänen et al., 2009). a significant advantage of allostratigraphy in respect to lithostratigraphy is that it enables the setting up of a sequence framework which is particularly effective in basin-scale reconstructions, as it allows the definition of units with comparable ages but encompassing deposits with very varied sedimentary facies (miall, 1996). an allostratimozzi p. et al. 42 graphic approach enables genetically-related heterogenous deposits, e.g. interfingering alluvial and lacustrine deposits, to be grouped within a single stratigraphic unit (hughes, 2007). whilst allostratigraphy is a form of sequence stratigraphy (hughes, 2007), it provides the possibility of separating sedimentary bodies of similar lithology basing on the presence of a significant unconformity (rawson et al., 2002). the hierarchic organization of a sedimentary succession in allomember, alloformation, allogroup, or subsynthem, synthem, supersynthem strictly depends on the magnitude of each bounding unconformity (e.g., miall, 1988, 1991). to this respect, the analysis of unconformities is crucial for the definition of an allostratigraphic framework. nevertheless, the recognition, tracing and ranking of unconformities is particularly problematic in quaternary continental successions, where unconformities often correspond to erosive surfaces with irregular geometries, and need to be correlated across different sedimentary environments and basins that can be physically separated. this paper proposes the integration of boreholes, geological maps and digital elevation models (dems) to reconstruct the three-dimensional geometry and analyze the lateral variability of a portion of the regional unconformity, which separates the sedimentary complex of the last glacial maximum (lgm) from the post-lgm one. the investigation focuses on the brenta megafan (fig. 1), a ca. 3000 km2 wide alluvial system which was chosen in order to test the method across a whole range of sedimentary environments, from braided gravelly channel belts in the alpine piedmont to clayey-silty distal plain, and extending also to the related deltas and lagoon. this unconformity formally represents the base of the postglacial synthem (“po synthem”) in several 1:50,000 scale carg geological maps in the friulian plain (zanferrari et al., 2008a, b, c; fontana et al., 2012) and in the venetian area (tosi et al., 2007a, b; cucato et al., 2012). it has been recognized in the underground of the venetianfriulian plain (mozzi et al., 2003; primon & fontana, 2008; fontana et al., 2008, 2010, 2012), as well as in the po delta (amorosi & marchi, 1999; correggiari et al., 2005; stefani & vincenzi, 2005), in the northern adriatic shelf (trincardi & argnani, 2003; trincardi et al., 2011) and along its western coast (amorosi et al., 2008). this investigation provides new insights for basin-scale correlatability of unconformities related to major pleistocene glacial-interglacial cycles. fig. 1 the megafans of the venetian-friulian plain (modified from fontana et al., 2008). integrating dem and stratigraphic data for the reconstruction of the post-lgm unconformity … 43 2. settings 2.1. geology and geomorphology the brenta megafan is part of the foreland basin of the uplifting eastern southalpine chain (e.g., castellarin et al., 1992; carminati et al., 2003; stefani et al., 2007; barbieri et al., 2007). within about 20 km from the mountain front the megafan is relatively steep (average gradient 3-5‰), consisting of gravel deposits, hundreds of metres thick, related to braided channel sedimentation (mozzi, 2005). further downstream, where topographic gradient gradually decrease to less than 1‰, the geomorphic features mainly consist of sandy fluvial ridges separated by silty-clayey floodbasins (bondesan & meneghel, 2004; mozzi, 2005; bondesan et al., 2008). climate change and eustasy forced by glacialinterglacial cycles appear to be the main driving factors in the upper pleistocene and holocene evolution of the brenta megafan (mozzi, 2005; mozzi et al., 2010), as well as of the other megafans of the venetian-friulian plain (fontana et al., 2008, 2010; carton et al., 2009). a phase of maximum aggradation took place during the peak of lgm, that in a global perspective lasted between 26.5-19 cal ka bp (clark et al., 2009). in that period the eastern southern alps were occupied by extensive glacial systems (ehlers & gibbard, 2004): the piave and tagliamento glaciers reached the plain, building terminal moraine ridges (carton et al., 2009; monegato et al., 2007); the astico glacier, connected by transfluence to both the adige and brenta glaciers, had its front few kilometres from the plain (cucato, 2001; rossato et al., 2013). the brenta glacier front is regarded to have been located about 10 km upstream of the brenta valley mouth, near valstagna, but evidence of its precise position is lacking (trevisan, 1939). in this period the venetian-friulian megafans achieved their maximum areal expansion (fontana et al., 2008). the lgm brenta megafan extended from the sile r. to the berici hills (mozzi et al., 2003; mozzi, 2005; monegato et al., 2011) (fig. 1). the thickness of lgm deposits in the distal sectors of the brenta megafan is about 20 m (tosi et al., 2007a; bondesan et al., 2008; cucato et al., 2012), which is coherent with the thickness of 20-30 m observed in the lower tracts of most venetian-friulian megafans (fontana et al., 2010). aggradation in the brenta megafan continued until about 17.5 cal ka bp, with apparent lower rates than at the peak of lgm (mozzi, 2005; fontana et al., 2010). in the tagliamento megafan and in the other alluvial systems connected with the tagliamento glacier (corno, cormor and torre outwashes) the late lgm was instead characterized by an early phase of downcutting at the fanhead and the formation of telescopic fan lobes in the distal plain (fontana, 2006; fontana et al. 2008, in press). a dramatic erosive phase took place in all the venetian-friulian megafans at the end of the lgm, during the deglaciation of the lowest sectors of the southern eastern alps (fontana et al. 2008, 2010). fluvial downcutting in the brenta megafan started after 17.5 cal ka bp and led to the formation of incised valleys (sensu darlymple, 2006) in the plain (from now abbreviated as iv), which reached depths of 10-20 m (iliceto et al., 2001; mozzi, 2005; mozzi et al., 2010; cucato et al., 2012). the interfluves between ivs consist of the terraced lgm alluvial plain. these surfaces experienced soil formation until their burial by later deposits or, in the case of large outcropping stretches of lgm, until present (for further details on soils, see following paragraph 2.2.). the proximal sector of the brenta megafan was deactivated due to the entrenching of the river near the valley outlet (mozzi, 2005). ivs are still detectable in the geomorphology of the upper tract of the megafan, near its apex, as they are laterally bounded by alluvial scarps which are more than 15 m high (figs. 1 and 2) (castiglioni, 1997; mozzi, 2005). these scarps gradually decrease downstream, finally disappearing at a distance of about 40 km from the mountain front. at the northwestern outskirts of city of padova, the scarps cut in lgm deposits are about 2-3 m high (ferrarese et al., 2006; mozzi et al., 2010; ninfo et al., 2011). here the oldest meander belts at the top of the valley fill were active between 12.0 and 6.5 cal ka bp (mozzi et al., 2010). this suggests that the infilling of the iv took place during late glacial and early holocene, and was basically completed by middle holocene. south of padova, 2-5 m thick alluvial deposits dated between 6.5 and 4.5 cal ka bp cover the lgm deposits (cucato et al., 2012). towards se, the holocene brenta deposits have ages varying between 4 and 1 cal ka bp and thickness of 2-4 m (bondesan et al., 2008; cucato et al., 2012). east of the brenta r. and in other extensive stretches north of padua and around the euganei hills, lgm portions crop out (mozzi, 2005; arpav, 2005; cucato et al., 2012). the distal brenta megafan is attached to the barrier-and-lagoon system of the venice lagoon, which started to form around 7.5-6.0 cal ka bp in response to sea-level rise (favero & serandrei barbero, 1978; brambati et al., 2003; amorosi et al. 2008). the venice lagoon is presently bounded by dykes and large portions of the surrounding alluvial plain are reclaimed land below mean sea level (fig. 2). the lagoonal and littoral deposits are part of the high-stand sedimentary wedge, consisting of sandy beach ridges, lagoons and deltas that rim the western sector of the northern adriatic sea. this sedimentary wedge covers the lgm alluvial deposits but it rapidly pinches out moving offshore (trincardi et al., 2011). in wide portions of the northern adriatic floor the fluvial lgm deposits are cropping out or covered by just a few-decimetres to 1-m-thick veneer of marine deposits, separated by a ravinement surface (correggiari et al., 1996; gordini et al., 2002, 2003; trincardi et al., 2011). 2.2. soils on lgm deposits recent soil surveys carried out in the brenta megafan (ragazzi et al., 2004; arpav, 2005; dalla rosa et al., 2012) evidence that the soils with the highest degree of development are those formed on the exposed lgm plain. soils developed on lgm gravels show a characteristic profile differentiation, with calcium carbonate leaching in the epipedon and clay illuviation to deep bt horizons. these well-drained soils have 30-40 cm thick argillic bt horizons, with hue 7.5yr (munsell soil color charts), and are classified as cutanic luvisols in the fao world reference base for soil resources (wrb) classification (ragazzi et al., 2004). soils on the siltyclay floodplain of the distal sector of the lgm megafan are characterized by marked vertical mobilization of carmozzi p. et al. 44 bonates. typically, 20-30 cm thick leached bw horizons overlie some-decimetres-thick bk and ck calcic horizons (wrb calcisols), often displaying gley pedofeatures (mottling, iron-manganese nodules) in relation to the poor drainage of the soils (wrb gleyic calcisols). the loamy-sandy soils of the adjacent fluvial ridges have leached epipedons but, depending on the local hydrotopographic conditions, do not always have bk horizons and are classified as wrb hypereutric(-gleyic)cambisols. on the sandy channel deposits located in well-drained position on fluvial ridges, there are evidences of decarbonation of the top horizons, occasionally with traces of clay illuviation in the bt/bw horizons. in the distal sector of the brenta megafan the soils developed at the top of the lgm succession are often buried by holocene deposits. in the venice lagoon the lgm deposits are covered by the holocene deltaic and barrier-and-lagoon sedimentary complex. though these sedimentary bodies may locally have erosive basal boundaries (e.g. channel scours, ravinement surface), the soils on top of lgm alluvium are largely preserved. the most known of these soils is the so-called “caranto paleosoil” (gatto & previatello, 1974; mozzi et al., 2003; donnici et al., 2011), which is characterized by well developed calcic and gley horizons on silty-clay parent material. from the geotechnical point of view the caranto is regarded as an “overconsolidated clay”, as soil horizons are particularly stiff (in the average 3-5 kg/cm2) if compared to overlying and underlying layers. this geotechnical property makes the caranto palaeosoil relatively easy to be recognized in cores, penetrometric tests and seismo-acoustic soundings (stefanon, 1980; mcclennen & ammerman, 1997; zecchin et al., 2009), thus allowing for reliable stratigraphic correlation and mapping. in fact, it has been commonly used as the stratigraphic marker of the boundary between the upper pleistocene fluvial sequence and the holocene barrierand-lagoon deposits (e.g., tosi, 2007a, b). the lgm plain which was buried by middle and late holocene alluvial sediments, s and se of padua, also displays calcisols and cambisols which correlate with the caranto paleosoil (cucato et al., 2012). to all effects, the buried caranto palaeosoil corresponds to the post-lgm unconformity and it is in physical continuity with the soils developed on the stretches of the presently exposed lgm alluvial plain. the typical fine-grained caranto palaeosoil is easily recognized in corings due to overconsolidation, abundance of carbonate nodules and evidence of iron mottling. where sandy parent material is present, the soil properties are far less expressed and diagnostic, thus in the cores the detection of the post-lgm unconformity is less easy and probably often underestimated (mozzi et al., 2003). 3. datasets and processing 3.1. synopsis in the first step of the research, a dem of the present topography of the brenta megafan (fig. 2) and a fig. 2 hillshaded dem of the brenta megafan, with 2-m contours. the present venice lagoon is in light green. integrating dem and stratigraphic data for the reconstruction of the post-lgm unconformity … 45 geological map of the lgm deposits (fig. 3) were created. subsequently, boreholes and sections with information on the nature and depth of burial of the postlgm unconformity, as well as on the stratigraphy of the alluvial succession, were introduced in the geographic information system (gis) as stratigraphic control points (scp) (fig. 3; tab. 1). additional information were derived from maps of the base of post-lgm sediments in the venice lagoon and its mainland (tosi et al., 2007b; primon & fontana, 2008) (fig. 4). different correlation and interpolation methods were applied for modeling the unconformity in the pedogenized interfluves and in ivs. gis operations were carried out using microsoft exceltm for calculation, arcgis 10.0tm for digitizing and interpolation of spot heights, and idrisigistm for interpolation, filtering, and feature extraction. processing procedures were carried out in a raster dataset with cells of 30 m. 3.2. the digital elevation model the dem of present topography was produced within a collaborative project of the department of geography of the university of padova and the environmental protection agency of the veneto region (arpav), regarding the whole venetian plain. the ve fig. 3 geological sketch map of the brenta megafan with location of scps (see table 1), geological and geomorphological maps. the present venice lagoon is in light blue. tab. 1 the stratigraphic control points (scps). mozzi p. et al. 46 neto region produces maps at scale 1:10,000 and 1:5,000 (ctr carta tecnica regionale), which contain elevation points with declared range of error ±1.2 m, mostly deriving from analog stereo restitution of aerial images at average scale 1:18,000. the accuracy and density of 20-70 points per km2 allow for a fairly detailed description of the main alluvial landforms (castiglioni et al., 1987; castiglioni, 1999; castiglioni, 1997; bondesan & meneghel, 2004; mozzi, 2005; ferrarese et al., 2006; ninfo et al., 2011). contour lines with the spacing of 1 m for heights >5 m a.s.l., and 0.5 m in the areas below, were drawn on hard copy ctr maps. a manual interpolation was preferred to other automatic methods in the drawing of the contour lines, as this procedure allows the operator to discard all those points on modern artifacts which are regarded not to be representative of the surrounding topographic surface, such as roads and railway tracks on embankments, bridges, dikes, gravel and sand pits, farm yards, etc. the dem was originated from interpolation of the contour lines with an optimized version of the triangulated irregular network (tin). the comparison of the ctr-derived dem with lidar data in the surroundings of padua shows that the ctr dem provides a good approximation of the mean natural surface of the alluvial plain, even though it tends to “oversmooth” landforms (ninfo et al., 2011). in the venice lagoon, the dem results from the interpolation of 0.5-m bathymetric contours from bondesan & meneghel (2004). 3.3. geological and geomorphological data geological and geomorphological surveys at scale 1:50,000 cover the whole distal sector of the brenta megafan and some portions of its middle part (bondesan & meneghel, 2004; tosi, 2007a, b; cucato et al., 2012; bondesan et al., 2008), providing indications on the extent of the lgm exposed surfaces (fig. 3). major fluvial landforms (e.g. fluvial scarps, incised valleys, alluvial ridges) were recognized and mapped on the dem. soil maps are also available in the whole study area at scale 1:250,000 (arpav, 2005), and scale 1:50,000 in the venice and padova provinces and small parts of the fig. 4 map of the base of post-lgm sediments in the province of venice (modified from primon & fontana, 2008). integrating dem and stratigraphic data for the reconstruction of the post-lgm unconformity … 47 vicenza province (ragazzi et al., 2004; ragazzi & zamarchi, 2008; dalla rosa et al., 2012). routine physical-chemical analyses, chemical indexes of different iron forms (oxalate-extractable, dithionite-extractable and total iron) and micromorphological analyses of diagnostic horizons were carried out on selected soil samples during these surveys. these investigations helped in the recognition of soil chronosequences and the detection of the alluvial surfaces exposed to soil formation since lgm. the definition of the general stratigraphic framework benefits of recent papers on the late quaternary evolution of the venetian-friulian megafans and coastal areas (amorosi et al., 2008; fontana et al., 2008, 2010; zecchin et al., 2009; piovan et al., 2012) and, more specifically, of the brenta megafan (mozzi, 2005; mozzi et al., 2010; rossato et al., 2012). maps of the depth of the post-lgm deposits in the underground of the venice lagoon, based on seismic soundings and corings, are provided by tosi et al. (2007a,b). primon & fontana (2008) integrate these data with a large dataset of boreholes and correlate the caranto palaeosoil across the venetian mainland, presenting the elevation a.s.l. of the post-lgm unconformity through 2 m contour lines. cucato et al. (2012) provide indications on the thickness of post-lgm deposits in the plain s and se of padova, ranging between 2-5 m. pellegrini et al. (1984) allow to identify the unconformity in the middle tract of the megafan. data on the stratigraphy of the post-lgm valley fill and channel belts are presented in iliceto et al. (2001), mozzi et al. (2010) and cucato et al. (2012). in scp 10 (fig. 3 and tab. 1) the unconformity was recognized basing on lithofacies changes and its elevation is fully consistent with nearby scp 1 from outcrop data (pellegrini et al., 1984). scp 17 is located in the terminal tract of the brenta valley, where the post-lgm fluvial deposits directly lie on the limestone bedrock. 3.4. subsurface data processing the contour lines of the base of the post-lgm deposits from the maps of primon & fontana (2008) and tosi et al. (2007b) were digitized and geo-referred (fig. 4). the contour lines were interpolated with tin technique, in order to produce an elevation surface of the unconformity in this distal reach of the megafan. this surface is after indicated as udist_1. elsewhere, the depth and nature of the unconformity (erosional vs. hiatal with soil formation) were derived from cores and stratigraphic sections (tab. 1; fig. 3). each scp provides the elevation and characteristics of the unconformity, as well as the stratigraphy of the sedimentary successions. in the south-western corner of the megafan, the buried interfluve is limited to the n and e by ivs. elevation data in this sector of the unconformity were provided by scps 9, 14, 2, and 6. the elevations of the unconformity were interpolated with an inverse distance weight algorithm (idw, applying the function cos3), which was chosen because of the relatively small dimensions of the area (221 km2) and the even distribution of elevations. this procedure allowed to reconstruct the elevation surface of the unconformity, to which we refer as udist_2. upstream from padova the incised valleys could be mapped in detail thanks to the morphological evidence of their lateral slopes. these correspond to the original fluvial scarps which are still recognizable in the dem, even if they have been partly covered by middle and late holocene sediments and largely remodelled by local erosive processes. basing on the interpretation of contours in the map of primon & fontana (2008) (fig. 4), it was possible to trace the floor of the iv in this very distal reach of the megafan between -10 and -16 m a.s.l. nevertheless, a critical area is present between padova and the northern boundary of the map of primon & fontana (2008): here the valleys are completely filled, loosing morphological evidence in the plain topography, and no stratigraphic data were available. the highest uncertainty concerns the valley width, which has been assumed as comparable to the upstream and downstream reaches. as regards the reconstruction of the longitudinal profiles of ivs, simple linear trends between the exposed top of the valley fill, i.e. the topographic surface in the dem, and the unconformity elevation were calculated for each scp. the linear trend equation applied in the more upstream reach between scps 17, 10, 1 is the following: uiv_1 = ps * 1.034783306465 – 7.540390897056 r² = 0.998378264792 where: uiv_1 = unconformity surface corresponding to the erosive valley floor upstream of scp 1; ps = present topographic surface corresponding to the top of the post-lgm valley fill. between scps 10 and 1 and the cluster of scps in the area of padova (fig. 5) the equation is: uiv_2 = ps * 1.2685794626 – 13.7052467081 r² = 0.9229633297 where: uiv_2 = unconformity surface corresponding to the ero fig. 5 linear regression of the elevation of the post-lgm unconformity vs. the present topographic surface in the middle reach of iv in the brenta megafan (for location of scps see fig. 3). mozzi p. et al. 48 sive valley floor downstream of scp 1; ps = present topographic surface corresponding to the top of the post-lgm valley fill. the gradient of uiv_2 was maintained downstream of scp 15 to the intersection at -13 m a.s.l. with the floor of the incised valley recognizable in the map of primon & fontana (2008). the processing of subsurface data allowed for the production of elevation surfaces relative to specific sectors of the unconformity: i. pedogenized top of lgm deposits in the interfluves (udist_1 and udist_2); ii. base of post-lgm deposits in ivs upstream of scp 1 (uiv_1); iii. base of post-lgm deposits in ivs downstream of scp 1 (uiv_2). uiv_1 and uiv_2 were merged with a max (maximum between two values) cell-by-cell function. the resulting dem was then merged with udist_1 and udist_2 through a "covering" gis operation, in order to produce the final dem of the unconformity surface with cell size set at 30 m. this dem was after merged with that of the outcropping lgm surface, as it can be seen in fig. 6. the production of the dem of the unconformity allowed for the calculation of the volume of sediments which lie above it, separating ivs from interfluves. the operation was carried with the following work flow: i. extraction of the areas of deposition of post-lgm sediments on interfluves and in ivs; ii. subtraction of the elevations of the unconformity from the present topographic surface in each 30x30-m cell. 4. results and discussion data processing allowed for the three-dimensional modeling of the post-lgm unconformity (fig. 6). the low density of scps in the areas where isopach maps are not available represented the most problematic aspect. nevertheless, the unconformity on pedogenized interfluves represents the buried continuation of the lgm plain, and it can be assumed that it maintains similar morphologies and regular gradient. this was checked in the udist_2 sector, where idw interpolation proved to be effective. the recognition and modeling of the unconformity in ivs was also critical. notwithstanding, the remarkably high correlation between the elevations of the unconformity (i.e., the bottom of the valley fill) and the topographic surface (i.e., the top of the valley fill) supports the application of linear trend equations in the interpolation procedure. in the lower reach (uiv_2), where there are several scps, the correlation coefficient r² of the regression analysis is 0.923. the post-lgm unconformity resulted to extend on fig. 6 hillshaded dem of the post-lgm unconformity and exposed lgm deposits in the brenta megafan, with 2-m contours. the white line indicates the margin of the present venice lagoon. integrating dem and stratigraphic data for the reconstruction of the post-lgm unconformity … 49 about half of the brenta megafan; the hiatal unconformity on interfluves represents one third of the total, while the erosive unconformity is significantly smaller (tab. 2; fig. 7). the total volume of sediments which lie above the post-lgm unconformity is 10.4 km3: 6.1 km3 cover the interfluves and 4.3 km3 fill the ivs. the unconformity dem evidences the continuity between the exposed lgm surface and the unconformity on the buried pedogenized interfluves (fig. 6). in ivs, the unconformity corresponds to the erosive valley flanks and floors. valley slopes are steep and range in height from about 20 m at the fanhead to 4-6 m in the distal sector; valley floors are rather flat and range in width around 2-6 km. this geometry is coherent with the ivs observed with good detail in the tagliamento megafan, thanks to the availability of a large stratigraphic dataset and the marked contrast in sediment grain size of valley fills (fontana, 2006; fontana et al. 2008, 2012). to be noted that the tagliamento and piave megafans display multiple incisions in the distal sector. in the brenta megafan this was not evident from available stratigraphic data, but the possibility that other ivs cross the distal reaches downstream of padova cannot be excluded. the relations between the unconformity and the present topographic surface across the megafan can be observed in the cross sections of figs. 8 and 9. cross section aa’ and the downstream end of cc’ are particularly effective in evidencing the continuity between ex fig. 7 sketch map of the post-lgm unconformity in the brenta megafan, with location of cross sections of figs. 8 and 9. the black line indicates the margin of the present venice lagoon. tab. 2 extension of the post-lgm unconformity and volume of overlying sediments in the brenta megafan. mozzi p. et al. 50 posed and buried lgm top surface, as well as the onlap of post-lgm coastal deposits on the interfluve unconformity. cross section bb’ and the upper and middle portions of cc’ intersect the erosive unconformity and the top surface of the sedimentary fill in ivs. in bb’ it can be seen that both surfaces display a major knickpoint at around 30 m a.s.l., which corresponds to the transition from the gravelly piedmont sector to the fine-dominated lower portion. upstream of this knickpoint both surfaces have similar gradient around 3.5‰. downstream, the unconformity is slightly steeper (1‰) than the top surface of the valley fill (0.7‰). the unconformity keeps the same gradient below sea level and it dips to -18 m a.s.l. the present alluvial plain has a minor knickpoint around sea level, about 5 km upstream of the inner margin of the venice lagoon, where the topographic gradient averages zero. cross sections represented in fig. 9 are transverse to the longitudinal axis of the megafan. dd’ evidences the convex morphology of the lgm megafan apex and the wide post-lgm incision. the overall convexity of the distributive systems is evident also in ee’, which shows the almost complete infilling of ivs and their characteristic morphology with flat floor and steep slopes. cross sections ff’, gg’, and the lower part of cc’ document the complete infilling of ivs by post-lgm sediments, which also buried the surrounding interfluves. to be noticed that the eastern iv in ff’ is significantly wider than the ones in ee’; this is due to the merging of two ivs and the slightly transverse direction of the cross section in respect to the valley. fig. 8 longitudinal cross sections in the brenta megafan, showing the present topographic surface (red line) and the post-lgm unconformity (blue line) (for locations see fig. 7). integrating dem and stratigraphic data for the reconstruction of the post-lgm unconformity … 51 in the middle portion of the megafan, nearby padova, the unconformity in the ivs is close to sea level (fig. 6 and fig. 9 cross section bb’). this is due to the above-mentioned steeper gradient of the erosive unconformity in respect to present topographic surface, and implies that the river was related to a base level which was significantly lower than present. in fact, this is consistent with the timing of ivs downcutting, which took place not later than late glacial (mozzi et al., 2010) when the adriatic sea was still lower than -50 m a.s.l. (lambeck et al., 2004; amorosi et al., 2008). the holocene relative sea-level rise conditioned the deposition of the coastal wedge on top of the unconformity, as evidenced at the downstream end of cross section aa’, where the lagoonal sediments covering the unconformity pinch out landwards at 0 m a.s.l. also the minor knickpoint around 0 m a.s.l. in the present alluvial plain in cross section bb’ can be interpreted as the response of the fluvio-deltaic system to sea level. in the most distal sector, the unconformity is buried by barrierand-lagoon deposits, which are up to 25 m thick, as evidenced in cross section gg’. 5. conclusions the interpolation and linear regression of stratigraphic and topographic data in the brenta megafan resulted in the production of the dem of the post-lgm unconformity from the eastern southalpine piedmont to the adriatic coast. this means that the depth of burial, the elevation a.s.l., and the nature (erosive vs. hiatal with soil formation) of the unconformity were mapped on a 30x30-m grid base on an area of ca. 3000 km2. the reconstructed unconformity surface is coherent with local stratigraphic settings, showing the consistency of processing procedures. nevertheless, the accuracy of results is evidently related to the number and geographic distribution of available scps. thus, in the piedmont and medium sector of the megafan, it was possible to check the model only in few sites. moreover, from padova to the margin of venice lagoon the estimation of the width and precise path of the iv was only hypothesized. morphometric analysis of the dem enabled to evaluate the gradients of the unconformity in long and transverse profiles, as well as to calculate its overall extension (1491 km2), the areas where it is characterized by buried soils (970 km2), and those where it corresponds to an erosive surface in ivs (521 km2). the subtraction of the dem of the unconformity from the present topographic surface allowed for the first calculation of the volume of post-lgm alluvial and coastal sediments (10.4 km3), differentiating those which bury the interfluves (6.1 km3) from ivs fills (4.3 km3). the three-dimensional modeling of this surface proved to be a valuable aid for the analysis of the forcing of sea level on the post-lgm progradation of the fig. 9 transverse cross sections in the brenta megafan, showing the present topographic surface (red line) and the post-lgm unconformity (blue line) (for locations see fig. 7). mozzi p. et al. 52 brenta megafan. the results evidence the correlatability of the unconformity across a wide distributive alluvial system and connected deltaic and barrier-and-lagoon systems. the method can potentially be applied to neighboring megafans of the venetian-friulian and eastern po plain and extended offshore to the tip of the deltaic systems. this provides a tool for basin-scale stratigraphic correlations and quantitative estimate of erosive processes and sedimentary storage during the post-lgm on the northern adriatic shelf. acknowledgments this investigation was carried out within cariparo project of excellence 2007/2008 “padova underground, a geoarchaeological investigation of the city”. sandro rossato contributed to the description of core scp 10. the reviewers and editors of amq provided useful comments and suggestions which contributed to the quality of the paper. references amorosi a., marchi n. (1999) high-resolution sequence stratigraphy from piezocone tests: an example from the late quaternary deposits of the southeastern po plain. sedimentary geology, 128(1-2), 67-81. amorosi a., fontana a., antonioli f., primon s., bondesan a. (2008) post-lgm sedimentation and holocene shoreline evolution in the nw adriatic coastal area. geoacta, 7, 41-67. arpav (2005) carta dei suoli del veneto alla scala 1:250.000, note illustrative. grafiche vinello, treviso, 383 pp, 1 map. barbieri a., di giulio a., massari f., asioli a., bonato m., mancin n. (2007) natural subsidence of the venice area during the last 60 myr. basin research, 19, 105-123. bondesan a., meneghel m. (eds.) (2004) geomorfologia della provincia di venezia, esedra, padova, 4 sheets, 516 pp. bondesan a., primon s., bassan v., fontana a., mozzi p., abba’ t., vitturi a. (eds.) (2008) carta delle unità geologiche della provincia di venezia. cierre edizioni, verona, 2 sheets, 160 pp. brambati a., carbognin l., quaia t., teatini p., tosi l. (2003) the lagoon of venice: geological setting, evolution and land subsidence. episodes, 26, 264268. breckenridge r.m., othberg k.l., kauffman j.d. (2005) surficial geologic map of the mica bay quadrangle, kootenai county, idaho. idaho geological survey, moscow, idaho. carminati e., doglioni c., scrocca d. (2003) apennines subduction-related subsidence of venice. geophysical research letters, 30 (13), 1717. carton a., bondesan a., fontana a., meneghel m., miola a., mozzi p., primon s., surian n. (2009) geomorphological evolution and sediment transfer in the piave river watershed (north-eastern italy) since the lgm. géomorphologie: relief, processus, environment, 3/2009, 37-58. castellarin a., cantelli l., fesce a.m., mercier j., picotti v., pini g.a., prosser g., selli l. (1992) alpine compressional tectonics in the southern alps. relations with the n-apennines. ann. tecton., 6, 6294. castiglioni, g.b. (ed.) (1997) carta geomorfologica della pianura padana, scala 1:250.000. selca, firenze, 3 sheets. castiglioni g.b. (1999) geomorphology of the po plain, 1997. geogr. fis. dinam. quat., suppl. 3, vol. 3, 7-20. castiglioni g.b., girardi a., rodolfi g. (1987) le tracce degli antichi percorsi del brenta per montà e arcella nei pressi di padova: studio geomorfologico. memorie di scienze geologiche, 34, 129-149. clark p., dyke, a., shakun j., carlson a., clark j., wohlfarth b., mitrovica j., hostetler s., mccabe a. (2009) the last glacial maximum. science 325, 710-714. c.n.r. commissione per la cartografia geologica e geomorfologica (1992) carta geologica d’italia – 1:50.000. guida al rilevamento. servizio geologico nazionale, quaderni serie iii, 1, istituto poligrafico dello stato, roma, 203 pp. correggiari a.m., cattaneo a., trincardi f. (2005) the modern po delta system: lobe switching and asymmetric prodelta growth. marine geology, 222223, 49-74. correggiari a., roveri m., trincardi f. (1996) late pleistocene and holocene evolution of the north adriatic sea. il quaternario – italian journal of quaternary sciences, 9, 697-704. cucato m. (2001) rilevamento della media val d’astico (provincia di vicenza): saggio per l’applicazione della normative sulla cartografia geologica del quaternario continentale. bollettino del servizio geologico d’italia, 115, 99-130. cucato m., de vecchi g.p., mozzi p., abbà t., paiero r., sedea r. (eds.) (2012) note illustrative della carta geologica d’italia alla scala 1:50.000, foglio 147 padova sud. ispra-servizio geologico d’italia – regione veneto, lts land technology & services, padova e treviso, 164 pp. dalla rosa a., garlato a., giandon p., ragazzi f., vinci i. (2012) carta dei suoli della provincia di padova, scala 1:50.000, arpav osservatorio regionale suolo, treviso. dalrymple r.w. (2006) incised valleys in space and time: an introduction to the volume and an examination of the controls on valley formation and filling. in: dalrymple r.w., leckie d.a., tillman r.w. (eds.): incised valleys in space and time, sepm spec. publ., 85, 5-12. donnici s., serandrei-barbero r., bini c., bonardi m., lezziero a. (2011) the caranto paleosol and its role in the early urbanization of venice. geoarchaeology, 26, 514-543. ehlers j., gibbard p.l. (eds.) (2004) quaternary glaciations extent and chronology, part i: europe. developments in quaternary science, vol. 2a. elsevier, amsterdam. favero v., serandrei barbero r. (1978) la sedimentazione olocenica nella piana costiera tra brenta ed adige. memorie della societa geologica italiana, 19, 337-343. ferrarese p., mozzi p., veronese f., cervo f. (2006) integrating dem and stratigraphic data for the reconstruction of the post-lgm unconformity … 53 high resolution dtm for the geomorphological and geoarchaeological analysis of the city of padua (italy). in: campana s., forte m. (eds.): from space to place, 2nd international conference on remote sensing in archaeology, 4-7 november 2006, british archaeological reports, international series, 1568, 291-296. fontana a. (2006) evoluzione geomorfologica della bassa pianura friulana e sue relazioni con le dinamiche insediative antiche. monografie museo friulano storia naturale, 47, udine, 288 pp. enclosed geomorphological map of the low friulian plain, scale 1:50,000. fontana a., mozzi p., bondesan a. (2008) alluvial megafans in the veneto-friuli plain: evidence of aggrading and erosive phases during late pleistocene and holocene. quaternary international, 189, 71-89. fontana a., mozzi p., bondesan a. (2010) late pleistocene evolution of the venetian-friulian plain. rendiconti lincei, volume 21, suppl. 1, 181-196. fontana a., bondesan a., meneghel m., toffoletto f., vitturi a., bassan v. (eds.) (2012) note illustrative della carta geologica d’italia alla scala 1:50.000 foglio 107 “portogruaro”. regione veneto, infocartografica, piacenza, 196 pp. fontana a., monegato g., devoto s., zavagno e., burla i., cucchi f. (in press). geomorphological evolution of an alpine fluvioglacial system at the lgm decay: the cormor type megafan (ne italy). geomorphology. gatto p., previatello p. (1974) significato stratigrafico, comportamento meccanico e distribuzione nella laguna di venezia di un’argilla sovraconsolidata nota come “caranto”. cnr. lab. studi grandi masse. technical report 70, venezia, 45 pp. gibbard p.l. (1985) the pleistocene history of the middle thames valley. cambridge university press, cambridge, 155 pp. gordini e., marocco r., vio e. (2002) subsurface stratigraphy of trezza grande bank (gulf of trieste, northern adriatic sea). gortania atti museo friulano storia naturale, 24, 31-61. gordini e., caressa s., marocco r. (2003) new morpho-sedimentological map of the trieste gulf (from punta tagliamento to isonzo mouth). gortania atti museo friulano storia naturale, 25, 5-29. heinrich p.v. (2006) pleistocene and holocene fluvial systems of the lower pearl river, mississippi and louisiana, usa. gulf coast association of geological societies transactions, 56, 267-278. hughes p.d. (2007) allostratigraphy/ morphostratigraphy. in: elias s. (ed.): encyclopedia of quaternary sciences, elsevier, amsterdam, 2841-2846. hughes p.d. (2010) geomorphology and quaternary stratigraphy: the role of morpho-, lithoand allostratigraphy. geomorphology, 123, 189-199. iliceto v., meloni f., mozzi p., rizzetto f. (2001) il sottosuolo della cappella degli scrovegni a padova. geol. tec. ambient., 9, 3-17. lambeck k., antonioli f., purcell a., silenzi s. (2004) sea-level change along the italian coast for the past 10,000 yr. quaternary science reviews, 23, 1567-1598. mcculloh r.p., heinrich p.v., snead j.i. (2003) geology of the ville platte quadrangle louisiana. to accompany the ville platee 30×60 minute geologic quadrangle. louisiana geological survey, geological pamplet no. 14, lousiana state university, baton rouge. 11 pp. mcclennen c.e., ammerman a.j. and schock s.g. (1997) framework stratigraphy for the lagoon of venice, italy: revealed in new seismic-reflection profiles and cores. journal of coastal research, 13, 745-759. miall a.d. (1988) architectural elements and bounding surfaces in fluvial deposits: anatomy of the kayenta formation (lower jurassic), southwest colorado. sediment geol., 55, 233-262. miall a.d. (1991) hierarchies of architectural units in clastic rocks, and their relationship to sedimentation rate. in: miall a.d., tyler n (eds.): the threedimensional facies architecture of terrigenous clastic sediments, and its implications for hydrocarbon discovery and recovery. society of economic paleontologists and mineralogists, concepts in sedimentology and paleontolology, 3, 6-12. miall, a.d. (1996) the geology of fluvial deposits: sedimentary facies, basin analysis and petroleum geology. springer, 582 pp. monegato g., ravazzi c., donegana m., pini r., calderoni g., wick l. (2007) evidence of a two-fold glacial advance during the last glacial maximum in the tagliamento end moraine system (eastern alps). quaternary research, 68, 284-302. monegato g., pini r., ravazzi c., reimer p.j., wick l. (2011) correlating alpine glaciation with adriatic sea-level changes through lake and alluvial stratigraphy. journal of quaternary science, 26(8), 791804. mozzi p. (2005) alluvial plain formation during the late quaternary between the southern alpine margin and the lagoon of venice (northern italy). geogr. fis. dinam. quat., suppl. 7, 219-230. mozzi p., bini c., zilocchi l., becattini r., mariotti lippi m. (2003) stratigraphy, palaeopedology and palynology of late pleistocene and holocene deposits in the landward sector of the lagoon of venice (italy), in relation to the “caranto” level. il quaternario – italian journal of quaternary sciences, 16 (1b), 193-210. mozzi p., piovan s., rossato s., cucato m., abbà t., fontana a. (2010) palaeohydrography and early settlements in padua (italy). il quaternario italian journal of quaternary sciences, 23(2bis), 409-422. nacsn north american commission on stratigraphic nomenclature (1983) north american stratigraphic code. bull. amer. ass. petr. geol., 67 (5), 841-875. ninfo, a., ferrarese, f., mozzi, p., fontana, a. (2011) high resolution dems for the analysis of fluvial and ancient anthropogenic landforms in the alluvial plain of padua (italy). geografia fisica e dinamica quaternaria, 34, 95-104. pasquarè g., venturini c. (eds.) (2005), mapping geology in italy. apat, servizio geologico d’italia, s.e.l.c.a., firenze, 336 pp. pellegrini g.b., paganelli a., penso d. (1984) aspetti geomorfologici e palinologici dei depositi fluviali nei pressi di carturo sul brenta (padova). geografia fisica dinamica quaternaria, 7, 36-39. mozzi p. et al. 54 piovan s., mozzi p., zecchin m. (2012) the interplay between adjacent adige and po alluvial systems and deltas in the late holocene (northern italy). géomorphologie: relief, processus, environment, 4/2012, 427-440. primon s., fontana a. (2008) carta della quota della base dei depositi post-lgm, scala 1:150.000. in: bondesan a., primon s., bassan v., fontana a., mozzi p., abba’ t., vitturi a. (eds.) (2008) carta delle unità geologiche della provincia di venezia. cierre edizioni, verona http://www2.difesasuolo.provincia. venezia.it/area/eventi-pubblicazioni/pubblicazioni/ geosinpav/carta _caranto.pdf. ragazzi f., vinci i., garlato a., giandon p., mozzi p., fiorentin r., calzolari c., ungaro f. (2004) carta dei suoli del bacino scolante in laguna di venezia, scala 1:100.000. arpav – osservatorio regionale suolo, castelfranco veneto, 399 pp. ragazzi f., zamarchi p. (eds.) (2008) carta dei suoli della provincia di venezia, scala 1:50.000. lac, firenze, 2 sheets, 267 pp. räsänen m.e., auir j.m., huitti j.v., klap a.k., virtasalo j.j. (2009) a shift from lithostratigraphic to allostratigraphic classification of quaternary glacial deposits. gsa today, 19, 4-11. rawson p.f., allen p.m., brenchley p.j., cope j.c.w., gale a.s., evans j.a, gibbard p.l., gregory f.j., hailwood e.a., hesselbo s.p., o’b knox r.w., marshall j.e.a., oates m., riley n.j., smith a.g., trewin n., zalasiewicz j.a. (2002) stratigraphical procedure. geological society, london, professional handbook, 64 pp. rossato s., monegato g., mozzi p., cucato m., gaudioso b., miola a. (2013) late quaternary glaciations and connections to the piedmont plain in the prealpine environment: the middle and lower astico valley (ne italy). quaternary interational, 288, 8-24. salvador a. (ed.) (1994) international stratigraphic guide: a guide to stratigraphic classification, terminology and procedure. international union of geologic sciences and geological society of america, boulder, co. stefani m., vincenzi s. (2005) the interplay of eustasy, climate and human activity in the late quaternary depositional evolution and sedimentary architecture of the po delta system. marine geology, 222, 19-48 stefani c., fellin m.g., zattin m., zuffa g.g., dalmonte c., mancin n., zanferrari a. (2007) provenance and paleogeographic evolution in a multi-source foreland: the cenozoic venetian-friulian basin (ne italy). j. sediment. res., 77, 867-887. stefanon a. (1980) sedimentologia del mare adriatico: rapporti tra erosione e sedimentazione olocenica. boll. oceanografia teorica e applicata, 2 (4), 281324. tomkeieff s.i. (1962) unconformity-an historical study. proceedings of the geologists’ association, 73(4), 383-417. tosi l., rizzetto f., bonardi m., donnici s., serandrei barbero r., toffoletto f. (eds.) (2007a) note illustrative della carta geologica d’italia alla scala 1:50.000, foglio 128 venezia. apat – regione veneto, systemcart, roma, 2 sheets, 220 pp. tosi l., rizzetto f., bonardi m., donnici s., serandrei barbero r., toffoletto f. (eds.) (2007b) note illustrative della carta geologica d’italia alla scala 1:50.000, foglio 148-149 chioggia-malamocco venezia. apat – regione veneto, systemcart, roma, 2 sheets, 164 pp. trevisan l. (1939) il glacialismo quaternario nell’altopiano dei sette comuni. bollettino comitato glaciologico italiano, 19, 99-113. trincardi f., argagni a. (eds.) (2003) carta geologica dei mari italiani, scala 1:250.000, foglio nl 33-10 ravenna, servizio geologico nazionale, 2 sheets, 151 pp. trincardi f., argagni a., correggiari a. (eds.) (2011) carta geologica dei mari italiani, scala 1:250.000, foglio nl 33-7 venezia, servizio geologico nazionale, 2 sheets, 108 pp. zanferrari a., avigliano r., grandesso p., monegato g., paiero g., m.e poli, stefani c. (eds.) (2008a) note illustrative della carta geologica d’italia alla scala 1:50.000, foglio 065 maniago. apat – regione friuli venezia giulia, graphic line sas, tavagnacco (ud), 224 pp. zanferrari a., avigliano r., monegato g., paiero g., m.e poli (eds.) (2008b) note illustrative della carta geologica d’italia alla scala 1:50.000, foglio 066 udine. apat – regione friuli venezia giulia, 176 pp., graphic line sas, tavagnacco (ud). zanferrari a., avigliano r., fontana a., paiero g. (eds.) (2008c) note illustrative della carta geologica d’italia alla scala 1:50.000, foglio 086 san vito al tagliamento. apat – regione friuli venezia giulia, graphic line sas, tavagnacco (ud), 190 pp. zecchin m., brancolini g., tosi l., rizzetto f., baradello l., caffau m. 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documenti pdf creati possono essere aperti con acrobat e adobe reader 5.0 e versioni successive.) /enu (use these settings to create adobe pdf documents suitable for reliable viewing and printing of business documents. created pdf documents can be opened with acrobat and adobe reader 5.0 and later.) >> >> setdistillerparams << /hwresolution [1200 1200] /pagesize [396.850 566.929] >> setpagedevice available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 34 (1), 2021, 5-16 an overview of the middle pleistocene in the north mediterranean region. flavia strani 1,2 , raffaele sardella 1 , beniamino mecozzi 1 1 dipartimento di scienze della terra, paleofactory, sapienza università di roma, italy. 2 istituto italiano di paleontologia umana, roma, italy corresponding author: f. strani <flavia.strani@uniroma1.it> abstract: the middle pleistocene was a crucial stage for the evolution of european mammals, a time when the majority of the modern taxa appeared in the continent for the first time. it is also in this interval that periodicity and intensity of glacial-interglacial cycles changed, an event that strongly impacted on mediterranean marine and terrestrial ecosystems, and on vertebrate communities. this area can thus be considered an important laboratory to investigate how major climatic events influenced mammals’ communities (among which also hominin populations) and the habitats they occupied. the state of art of the middle pleistocene palaeontological, archaeological and palaeoanthropological record of north mediterranean region, and of the italian peninsula in particular, is here discussed. keywords: chibanian, european ecosystems, early-middle pleistocene transition, biochronology, mammals, human evolution. 1. introduction the definition of the early-middle pleistocene boundary triggered an intense debate among quaternary geologists, stratigraphers, and palaeontologists (cita et al., 2006; gibbard & head, 2010; head & gibbard, 2015). a large consensus was reached during the xii inqua congress, and the beginning of the middle pleistocene was placed at the matuyama/bruhnes palaeomagnetic reversal (~0.78 ma), within the marine isotope stage (mis) 19. no doubts instead for the end of the middle pleistocene, placed at 129 ka, which corresponds to the beginning of the last interglacial (mis 5), that therefore marks the start of the late pleistocene. after a long-lasting debate, the middle pleistocene has been referred to the chronostratigraphic chibanian stage, from a sequence located in chiba prefecture (japan) and ratified by iugs in january 2020 (suganuma et al., 2021). the middle pleistocene subepoch represents a crucial phase for the earth system as it witnessed the change in the frequency of glacialinterglacial cycles from 41 kyr to 100 kyr occurred during the 1.20.4 ma (with some authors placing its onset as far back as 1.4 ma, see: head & gibbard, 2015) interval, an event known as the middle pleistocene revolution (mpr) or early-middle pleistocene transition (empt) (clark et al., 2006; head & gibbard, 2015; maslin & brierly, 2015). the consolidation of the empt is conventionally placed around the mis 12 11 passage during the mid-brunhes event (mbe) after which an increase of the amplitude of the glacial and interglacial periods is recorded (head & gibbard, 2015). during the last two decades, a large number of studies on the european middle pleistocene provided novel knowledge on palaeoenvironments, palaeoclimates and vertebrate communities, and a valuable amount of data on the mediterranean europe, and italian peninsula in particular. many issues are still unclear among the specialists, mainly due to the fragmentary framework of the discoveries. the state of art of the palaeontological, palaeoanthropological and archaeological research is thus crucial for a comprehensive understanding of european palaeoenvironmental dynamics and mammal palaeocommunities. here, we briefly discuss these aspects, offering an overview of key aspects on the study of the middle pleistocene in the mediterranean region. 2. old issues and new perspectives during the last two decades, the knowledge on middle pleistocene ecosystems has been enriched by a number of papers (e.g., rivals, 2012; strani et al., 2018; bellucci et al., 2021). of special interest are those focused on new methods, which allowed to investigate different aspects of archaeological and palaeontological deposits, or to correlate different palaeoenvironmental proxies and palaeoclimate records (rivals et al., 2009; strani et al., 2018). also, the application of isotopic analysis on sediments, speleothems and vertebrate remains has become more diffused (kuitems et al., 2015; pushkina et al., 2020). the results of these researches potentially provide crucial information on palaeoenvironments and climate. https://doi.org/10.26382/amq.2021.13 6 strani f. et al. another aspect which needs to be stressed concerns the radiometric method used for reliable chronological constrains of quaternary sedimentary successions. during the 1960s, these methodologies were already available for the specialists, but in the last decade the technological progress allows to refine the obtained chronological data with both radiometric (radiocarbon, ar-ar, u-series) and electron spin resonance (esr) dating. a number of studies focused on the definition of more accurate chronological framework have been published during the last decade, providing a new age for some key pleistocene deposits. an example is the new age of the fontana ranuccio deposit dated at 408 ±10 ka (pereira et al., 2018), whereas historically its age was of 458 ±6 ka (biddittu et al., 1979; segre & ascenzi, 1984) shifting the age of the deposits from full glacial conditions of mis12 to interglacial mis11. however, despite the increased use of the radiometric and esr methods, still nowadays only a limited number of european deposits possess reliable chronological constrains. this explains why the reconstruction of the human and vertebrate evolution and of quaternary ecosystems dynamics is based only on few localities (e.g., gliozzi et al., 1997). in addition to this, it is necessary to consider that many works were historically published on local journals, often in the authors native language (italian, spanish, french, etc..), or just discussed in master/doctoral theses. these researches are hardly available for international scientists, being a strong impediment in the understanding of palaeocommunity changes across the middle pleistocene. in summary, despite the recent improvement, palaeontological, palaeoanthropological and archaeological data for some middle pleistocene european localities, especially those of north-central mediterranean region, are either quite scarce or not well disseminated, and this represents an important limiting factor for the reconstruction of the mammal fauna evolution and their response to the environmental changes that occurred during this pivotal phase of the quaternary. a review of the state of art of middle pleistocene research and new data on historical key sites can therefore offer crucial data for the understanding of mediterranean palaeoenvironmental dynamics and mammal palaeocommunities. 3. the middle pleistocene terrestrial ecosystems in north-central mediterranean region 3.1. paleobotanical framework in northern mediterranean europe, a drop in temperature and a change in the dominant cyclicity strongly influenced the terrestrial ecosystems during the earlymiddle pleistocene transition until the end of pleistocene (bertini, 2010; russo ermolli et al., 2010a; kahlke et al., 2011; combourieu-nebout et al., 2015; head & gibbard, 2015; strani, 2020). the european vegetational landscapes generally changed following global climate patterns. as bertini (2010) pointed out, “a close correspondence between the climate fluctuations recorded by marine oxygen isotope records and long pollen records during the pleistocene indicates that there were also considerable regional differences in the vegetation structure, composition and responses to climate, depending on geographic and historical factors”. in the mediterranean area, and in the italian peninsula in particular, such a condition is evident. alternation of artemisia steppe and thermophilous forest marks the overall glacial-interglacial vegetation change. “taxodiaceae”, cathaya (plus p. haploxylon type), tsuga, cedrus, carya, pterocarya, along with other taxa, progressively disappeared throughout the pleistocene, with the last subtropical elements being extirpated during the middle pleistocene due to the increased severity of the glacial periods (bertini, 2010; manzi et al., 2011; combourieunebout et al., 2015). the effect of climatic changes can be clearly observed in central and southern italy, especially during glacial stages where the expansion of steppe and grasslands occurred (manzi et al., 2011). even if the record is quite fragmentary, a marked shift can be detected between 0.7-0.6 ma, probably due to the extreme climate conditions recognized during the mis 16. the following interglacial stage (mis 15) included modern taxa, as carpinus and ulmus, testifying therefore a clear vegetation turnover (manzi et al., 2011). another vegetational shifts occurred in correspondence of mis 12, with major effects in southern italy (russo ermolli et al., 2010b). the latter coincides with the mid-brunhes event (mbe), with marks the mis 12 11 transition, after which an increase of the amplitude of the glacial and interglacial periods is recorded. generally speaking, deciduous quercus or fagus dominated forests, and typical mediterranean taxa (e.g. quercus ilex) become the most common vegetation during middle pleistocene interglacials, whereas conifers, steppe and grasslands expanded during glacial periods (russo ermolli et al., 2010a,b; bertini, 2010; manzi et al., 2011; magri & palombo, 2013; combourieu-nebout et al., 2015). 3.2. mammal faunas and biochronology the mammal biochronological scale is based on the evolutionary degree of the faunal elements of the assemblages and on their dispersal, and therefore their first and last occurrences mark pivotal bioevents (gliozzi et al., 1997). the villafranchian/galerian transition (corresponding to the 1.2-0.9 ma interval) can be considered one of the most controversial issues in the european biochronological framework. the marked faunal turnover recorded within the jaramillo subchron occurred following the shift to glacial-interglacial cycles dominated by a 100 kyr frequency. the use of the term epivillafranchian, suggested by kahlke (2009) for the villafranchian/galerian transitional faunas, has been formally defined (bellucci et al., 2015). taking into account the data recorded from the european localities, during the epivillafranchian biochron, the first occurrence of praemegaceros verticornis, bison menneri, megaloceros savini, cervus elaphus and sus scrofa are recognized (bellucci et al., 2015). in the revised framework proposed by bellucci et al. (2015), the crocuta crocuta bioevent (sardella & palombo, 2007; sardella & petrucci, 2012) marks the beginning of galerian, and therefore the end of epivillafranchian. one of the most important sites for the study of the middle pleistocene is the area of ponte galeria (rome, central italy), where sedimentary sequences exposed in quarries have been studied by geologists and palaeontologists for decades. these deposits provided a rich fossil vertebrate collection, which allows the development of an important part of quaternary biochronology. the terms galerian and aurelian (mammal ages) themselves have their origin from ponte galeria sites and from many palaeontological sites located along the aurelia state highway, respectively (e.g., gliozzi et al., 1997; di stefano et al., 1998; petronio & sardella, 1999; milli et al., 2004; romano et al., 2021). after bellucci et al. (2015) revision the galerian mammal age includes three faunal units: ponte galeria, isernia and fontana ranuccio (gliozzi et al., 1997; petronio & sardella, 1999; fig. 1). since the end of the xx century a more detailed biochronological framework has been set up (milli et al., 2004; sardella, 2007; palombo et al., 2008, 2009; petronio et al., 2011; marra et al., 2014; bellucci et al., 2015; sardella et al., 2015). therefore, most of the more significative fossil mammal assemblages from which the middle pleistocene biochronology has been defined, come from the campagna romana area. for instance, at casal selce the large mammal fauna renewal of ungulates and carnivorans during the earlymiddle pleistocene transition is documented with the presence of mammuthus trogontherii, hemibos galerianus, praemegaceros verticornis and megaloceros savini (petronio & sardella, 1998; palombo & sardella, 2007; sardella & petrucci, 2012). as aforementioned, the fossil record of casal selce also documents the earliest occurrence of crocuta crocuta (c. crocuta event), that replaced the villafranchian giant hyaena pachycrocuta brevirostris (sardella & petrucci, 2012). among the bovids, important elements of the galerian faunas are bison schoetensacki, praeovibos and ovibos. as highlighted by iannucci et al. (2021), the aurochs bos primigenius spread around 0.5 ma in italy, becoming soon a common element of the galerianaurelian faunal assemblages of europe. in addition to these taxa, the rare water buffalo bubalus murrensis also occurs and spread into northern europe during temperate climatic stages (sardella, 2007 and references therein), whereas the hemibos galerianus is quite scarce (petronio & sardella, 1998; martinez-navarro & palombo, 2007). among cervids, in the early middle pleistocene european faunas praemegaceros verticornis, megaloceros savini and dama roberti are recorded (e.g., sardella et al., 2006; sardella, 2007; breda & lis 7 an overview of the middle pleistocene in the north mediterranean region fig. 1 integrated chronological scheme of the middle pleistocene and selected localities considered in this work (modified from gliozzi et al., 1997). project initiated during the 2015, whose preliminary results suggest that a possible late middle pleistocene age for the lower complex cannot be ruled out (sardella et al., 2018, 2019; mecozzi et al., 2021a). the narrownosed rhinoceros, s. hemitoechus is instead an important marker, as its earliest occurrence in europe is dated approximately at 0.5 ma (caune de l’arago, from levels chronologically referred to mis 14; moigne et al., 2006). among the equids, two villafranchian taxa persisted during the early middle pleistocene, equus altidens and equus sussenbornensis (boulbes & asperen, 2019). the modern caballoid diffused in europe approximately at 0.6 ma, but there are different interpretations of the variability of the middle pleistocene equids: as ecomorphological adaptations (equus ferus spp.) or as two distinct forms (equus mosbachensis and equus ferus) (boulbes & asperen, 2019 and reference therein). the first true horse remains have been generally attributed to e. mosbachensis, a taxon that appears present in europe from the early to the late middle pleistocene, until the first dispersal of equus ferus (e.g., boulbes & asperen, 2019; strani et al., 2019; mecozzi & strani, 2021; saarinen et al., 2021; strani et al., 2021). during the middle pleistocene equus hydruntinus is also recorded for the first time, but its dispersal is not a synchronous event. in spain, the earliest presence of this taxon is probably attested at about 0.6 ma, whereas in italy its dispersal is considered as chronological marker of the aurelian biochron (mis 10-9) (boulbes & asperen, 2019 and reference therein; fig. 1). in france, the earliest record of this equid is documented from late middle pleistocene localities of lunel-viel (mis 9-7) and orgnac (mis 9-8) (boulbes & asperen, 2019; brugal et al., 2021 this volume). another important event of the middle pleistocene is the earliest occurrence of the brown bear ursus arctos, historically placed within the fontana ranuccio faunal unit (fig. 1), based on findings unearthed in the homonymous local fauna of fontana ranuccio (0.4 ma, mis 11), where this species was found in association with ursus deningeri (azzaroli, 1983). the ursid record from this locality has been revised by conti et al. (2021), who cannot confirm with certainty the occurrence of u. arctos. in the fontana ranuccio locality are however recorded other modern taxa both within the large (e.g. cervus, dama, bos) and small mammal assemblage (e.g. lepus, erinaceus, eliomys) (strani et al., 2018; bona & strani, this volume). european primates and carnivoran records are quite scarce, and the majority of the mediumand largesized taxa became extinct during the middle pleistocene, like the large felid panthera gombaszoegensis (sardella, 2007). the barbary macaque, macaca sylvanus, is recorded in a few italian middle pleistocene localities (mecozzi et al., 2021c). its presence offers important data for the reconstruction of the mediterranean palaeoenvironments, and the findings associated with lithic artifacts require particular attention to the potential homo-macaca interactions during the pleistocene (strani et al., 2018; mecozzi et al., 2021c). in addition to iconic predators like crocuta crocuta and panthera sensu latu, other carnivorans characterized the middle 8 strani f. et al. ter, 2013; bellucci et al., 2021; stefanelli et al., 2021), which were replaced later by praemegaceros solilhacus and dama clactoniana (e.g., sardella et al., 2006; breda & lister, 2013; breda et al., 2015). the red deer appears in europe during the epivillafranchian (bermúdez de castro et al., 1997; iannucci et al., 2021 and reference therein), but its evolutionary history is still unclear. general consensus was reached in recognizing the simpler antler morphology of earlier forms, but different opinions on the validity and relationships of subspecies persist. for instance, based on the fossil record from the area of rome, four different chronosubspecies were instituted: cervus elephus acoronatus, cervus elephus eostephanoceros, cervus elephus rianensis and cervus elephus elaphus (leonardi & petronio, 1974; di stefano & petronio, 1992, 1993; di stefano et al., 1998; di stefano & petronio, 2002). one of the most abundant group of the middle pleistocene ecosystem is hippopotamuses, but there are conflicting opinions on their systematics and evolutionary history (e.g., caloi et al., 1980; mazza, 1991, 1995; mazza & bertini, 2013; van der made et al., 2017). however, hippopotamuses together with proboscideans and rhinoceroses were among the largest terrestrial mammals in galerian and aurelian assemblages. the proboscideans are well diffused across europe during the middle pleistocene. the earliest record of the straight tusked-elephant palaeoloxodon antiquus, attributed to epivillafranchian, was attested at vallparadìs estació, but this attribution was recently questioned (bellucci et al., 2015 and reference therein). however, the straight tusked-elephant is a very common element of galerian and aurelian assemblage (e.g., moncel et al., 2020a; abruzzese et al., 2016; rocca et al., 2018; rocca & aureli, 2020; stefanelli et al., 2021), until its disappearance, probably occurred during the early late pleistocene (mecozzi et al., 2021b and reference therein). another important biochronological marker for the galerian is the earliest dispersal of mammuthus trogontherii recognized at ponte galeria fu, which replaced the villafranchian species, mammuthus meridionalis (bellucci et al., 2015). rhinoceroses are represented by three taxa: stephanorhinus hundsheimensis, stephanorhinus hemitoechus and stephanorhinus kirchbergensis. the latter is quite sporadic in mammal communities, with a few specimens recorded at the middle pleistocene sites of visogliano (mis 13-10; pandolfi, 2013), ponte molle (mis 13; mecozzi et al., 2021) and tor di quinto (mis 13; pandolfi & marra, 2015). the earliest occurrence of s. hundsheimensis is attested during the late villafranchian (ballatore & breda, 2013 and reference therein), but its last occurrence needs to be clarified. pandolfi et al. (2018) attributed a few postcranial elements from grotta romanelli (lecce, southern italy) to hundsheim rhinoceros, hypothesizing a middle pleistocene age (~0.6 ma) for the levels k-i of this deposit. nevertheless, the lowermost levels of grotta romanelli have been historically referred to early late pleistocene because it directly overlies a tyrrhenian beach deposit (level k, mis 5e). with the aim to define a more accurate chronological scheme for the sequence of this key site, a new the importance of the italian territory and provides a revision of the pre-modern human fossil record from this region, updating the information previously reported in the “catalogue of italian fossil human remains from the palaeolithic to the mesolithic” (alciati et al., 2005). by the beginning of the middle pleistocene, the earliest acheulean homo heidelbergensis groups spread through europe. a site of particular interest is notarchirico (southern italy), where the earliest evidence of acheulean settlement in italy has been studied and placed even further back in time (moncel et al., 2020a). at notarchirico, four occupation levels have been unearthed, including one with bifaces dated through 40ar/39ar on tephras and esr on bleached quartz, that enable to place the occupation between 695 and 670 ka (mis 17), almost coeval with the moulin-quignon and la noira sites (france)(moncel et al., 2020a). as moncel et al. (2020a) pointed out, during the early middle pleistocene homo heidelbergensis groups arrived in europe, where they were exposed to “challenging environmental conditions, which may have stimulated new cultural responses”. the diversity of tools and activities observed at notarchirico, moulin-quignon and la noira sites shows that the north mediterranean was populated by adaptable hominins during this time. in particular, at the mis 17/mis 16 transition (670 and 650 ka), a very rapid expansion of shared traditions over western europe has been documented (muttillo et al., 2021). it must be stressed that the lithic samples over this period have been studied with different theoretical/methodological approaches preventing a comprehensive discussion. for instance, different approaches have been used even for the study of artefacts collected in distinct stratigraphical units of the same site (muttillo et al., 2021 and reference therein). however, as stated by muttillo et al. (2021), the technical behaviors documented during the early middle pleistocene (between mis 17/16 and mis 12) in the italian peninsula are extremely diversified. finally, the authors highlighted how a homogeneous and comprehensive study of all italian lithic samples of this period is required as a starting point to perform a large comparison of the various industries of the italian peninsula and also to evaluate them in a broadest european context. middle pleistocene lithic assemblages of europe also show a great variability in technological and typological characteristics (wiśniewski, 2014; malinskybuller, 2016; villa et al., 2016; picin, 2017). no general consensus was reached on how to interpret of this variability, especially in relation with the lower-middle paleolithic transition (lmpt) occurred during the middle pleistocene (mis 9-8) (malinsky-buller, 2016). the lmpt is marked by the passage from biface production to levallois technology (malinsky-buller, 2016). a recent large revision carried out by moncel et al. (2020b), suggests that the emergence of the middle paleolithic is older than generally supposed, and it can be referred to mis 12. in addition, the authors highlight that during the early middle paleolithic other technologies were also used. an important question rises about why the levallois technology became the dominant technological strategy of the middle paleolithic from the mis 9, which needs to be investigated (moncel et al., 2020b). the early human presence in the italian peninsula, pleistocene ecosystems as hyaena prisca, canis mosbachensis, cuon alpinus, meles meles and lynx pardinus (caloi & palombo, 1983; palombo & sardella, 2007; palombo et al., 2008, 2009; mecozzi et al., 2017, 2020a, b, 2021d; mecozzi, 2021). another important faunal renewal took place ~0.3 ma (mis 9), marking the beginning of the aurelian mammal age, where the last villafranchian representatives and few galerian taxa disappeared, replaced by new modern-like species such as the wolf canis lupus, the bears ursus arctos and ursus spelaeus, megaloceros giganteus, as well as the brown hare lepus europaeus (gliozzi et al., 1997, di stefano et al., 1998; palombo et al., 2002). the most famous italian local fauna of the torre in pietra fu is that of the iconic site of la polledrara di cecanibbio (marano et al., 2021). in france, early aurelian assemblages can be related to the biochron mnq24, characterized by the first occurrence of saiga tatarica (never recorded in italy), ursus spelaeus, capra ibex and coelodonta antiquitatis (sardella, 2007 and references therein). important early aurelian french assemblages are recorded at lunel viel and coudoulous i (brugal et al. 2021; fernandez et al. 2021). interestingly, bioclimatic models indicate that the palaeoecological requirements of species were very similar between the different faunal associations of the french locality of coudoulous i, and that -while significant climatic changes occurredthey prevented a complete species turn-over. this is in accordance with what observed in central italy, where similar herbivorous mammals adopted similar palaeoecological adaptations during mis 15 and during mis 11 (strani et al., 2021). the climatic deterioration occurred during the last 0.3 ma provided the ecological basis for the appearance of the cold-stage fauna generally known as mammuthus -coelodonta faunal complex, which characterized the late middle and late pleistocene of the northern hemisphere (kahlke, 1999). in the italian peninsula, this cold adapted faunal complex was recorded only during the late pleistocene, but the record of mammuthus primigenius and coelodonta antiquitatis is quite poor. in french, these taxa appeared during the late middle pleistocene, where probably favorable climatic condition established earlier (palombo & valli, 2004). in sum, the northern mediterranean area, allows for the in-depth study of how the climatic shift of the middle pleistocene influenced the palaeocommunities both in terms of evolution and composition of mammal taxa. 3.3. middle pleistocene human populations the middle pleistocene witnessed some important events in the history of human evolution. the italian human presence is documented by a rich fossil record and archaeological evidences found in a number of deposits (e.g., belli et al., 1991; piperno, 1999; manzi et al., 2001; scott & gibert, 2009; manzi et al., 2011; aureli et al., 2012; gallotti & peretto, 2015; peretto et al., 2015; moncel et al., 2019, 2020a,b). the italian peninsula has an important role in the study of the european middle pleistocene human populations, especially for the emergence of the mode 2 technology and the dispersal of homo heidelbergensis and homo neanderthalensis. buzi et al. (2021) confirms 9 an overview of the middle pleistocene in the north mediterranean region 10 strani f. et al. in addition to the fragmentary femur collected from the upper levels of notarchirico (moncel et al., 2020a and reference therein), is documented at isernia la pineta (mis 15, isernia, southern italy) by an isolated deciduous incisor (peretto et al., 2015). fontana ranuccio (frosinone, central italy) can be considered one of the most important sites, with 4 isolated human teeth, many vertebrate taxa and tools (biddittu et al., 1979; segre & ascenzi, 1984; rubini et al., 2014; zanolli et al., 2018; grimaldi et al., 2020). palaeoecological data from the fontana ranuccio site provide new information on the environments occupied by middle pleistocene homo in the italian peninsula. dietary adaptations of the ungulate community and of small mammal taxa suggest that homo populations occupied a region characterised by widespread wooded environments, and with grasslands inhabited mostly by groups of large ungulates, as attested by the diverse types of dietary behaviours observed in this group, with a relative dominance of cervids displaying a browsing or mixed diet (strani et al., 2018), and by enamel isotopic data (strani et al., 2019). harsher climatic conditions during adverse seasons may had played a key role, driving ungulates that needed a large amount of food intake, such as the large-sized aurochs (bos primigenius), to feed also on sub-optimal resources (strani et al., 2018). another important locality for human evolution is ceprano (mis 11, frosinone, central italy), where a partial cranium was historically discovered (manzi et al., 2001; manzi, 2016; di vincenzo et al., 2017). this specimen, recently revised, is ascribed to homo heidelbergensis by manzi (2016). finally, of considerable interest are the fossils recovered from the end of the middle pleistocene from altamura (bari, southern italy) and saccopastore (rome, central italy). the first site includes a probably complete skeleton with a cranium embedded in calcite concretions attributed to homo neanderthalensis (lari et al., 2015; di vincenzo et al., 2019). the latter yielded two nearly complete crania of h. neanderthalensis, saccopastore 1 and saccopastore 2 (sergi, 1944, 1948, 1962; bruner & manzi, 2006, 2008). the age of the deposit was historically attested to the last interglacial, but a recent reassessment of the aggradational succession in the area of rome suggested an oldest chronology (mis 7, marra et al., 2015). 4. conclusion the roots of “modern” terrestrial ecosystems in the mediterranean region can be placed in the middle pleistocene, when global climate patterns strongly conditioned the european vegetational landscape changes and those in the large ungulates and carnivoran guilds. however, the gap of knowledge or not up-to-date information from some historical middle pleistocene keylocalities of the mediterranean region is a major concern for quaternary research. in italy for instance, many works were published during the xx century on noteasily accessible local journals, and some materials were never formally described, limiting the available information on middle pleistocene quaternary ecosystems. the literature revision of historical palaeontological and archaeological works can help to obtain a more comprehensive framework of human and other mammals’ evolution. furthermore, historical museum collections such as those partially studied during the xx century, represent a palaeontological and archaeological heritage with significal scientific and socio-cultural value (demiguel et al., 2021). these collections are of great importance to describe unpublished material or reevaluate the information of the published ones, as for instance the fossils from the middle pleistocene localities of fontana ranuccio (conti et al., 2021), fontignano (iannucci et al., 2021), lunel-viel (brugal et al., 2021) and ponte molle (mecozzi et al., 2021). overall, the archaeo-geo-palaeontological evidence from italy and france presented in this volume is of particular interest to depict an accurate reconstruction of the modern terrestrial communities’ changes toward the contemporary world of the holocene. acknowledgements we are grateful to alpine and mediterranean quaternary for their interest and predisposition in publishing all these scientific contributions in this special volume, in particular to dr. ilaria mazzini and prof. marco peresani, for their assistance and dedication, and all the staff members of the journal. we also thank all the reviewers that through their comments and suggestions helped authors to improve the original papers. finally, we would like to thank the authors for their participation in this volume and for their contributions. we thank the many colleagues with whom we have collaborated in the study of the middle pleistocene, especially daniele aureli, luca bellucci, fabio bona, marzia breda, jacopo conti, antonio curci, camille daujeard, alessio iannucci, dawid adam iurino, marie-hélène moncel, alfio moscarella and roxane rocca. references abruzzese c., aureli d., rocca r. (2016) assessment of the acheulean in southern italy: new study on the atella site (basilicata, italy). quaternary international, 393, 158-168. alciati g., pesce delfino v., vacca e. (2005) catalogue of italian fossil human remains from the palaeolithic to the mesolithic. journal of anthropological sciences, 83(suppl.), 1-184. azzaroli a. (1983) quaternary mammals and the “endvillafranchian” dispersal event a turning point in the history of eurasia. palaeogeography, palaeoclimatology, palaeoecology, 44(1-2), 117-139. aureli d., contardi a., giaccio b., modesti v., palombo m.r., rozzi r., sposato a., trucco f. (2012) straight-tusked elephants in the middle pleistocene of northern latium: preliminary report on the ficoncella site (tarquinia, central italy). quaternary international, 255, 29-35. doi: 10.1016/j.quaint.2011.06.052 ballatore m., breda m. (2013) stephanorhinus hundsheimensis (rhinocerontidae, mammalia) teeth from the early middle pleistocene of isernia la pineta (molise, italy) and comparison with coeval british material. quaternary international, 302, 169 -183. belli g., belluomini g., segre-naldini e., cassoli p., cecchi s. (1991) découverte d'un fémur humain acheuléen à notarchirico (venosa, basilicate). l'anthropologie (paris), 95(1), 47-88. bellucci l., sardella r., rook l. (2015) large mammal biochronology framework in europe at jaramillo: the epivillafranchian as a forma biochron. quaternary international, 389, 84-89. bellucci l., palombo m.r., demiguel d., strani f., alberdi m.t. (2021) new taxonomical, biochronological and palaeoenvironmental data from the middle pleistocene site of cúllar de baza 1 (granada, spain). quaternary science reviews, 261, 106932. doi: 10.1016/j.quascirev.2021.106932 bermúdez de castro j.m., arsuaga j.l., carbonell e., rosas a., martínez i., mosquera m. (1997) a hominid from the lower pleistocene of atapuerca, spain: possible ancestor to neandertals and modern humans. science, 276, 1392-1395. bertini a. (2010) pliocene to pleistocene palynoflora and vegetation in italy: state of the art. quaternary international, 225 (1), 5-24. biddittu i., cassoli p.f., radicati di brozolo f., segre a.g., segre naldini e., villa i. (1979) anagni a k/ ar dated lower middle pleistocene site, central italy: preliminary report. quaternaria, 21, 53-71. bona f., strani f. (2021) new data on the middle pleistocene small mammal fauna from the homo bearing site of fontana ranuccio (anagni basin, central italy). alpine and mediterranean quaternary, 34 (1), 69-74. doi: 10.26382/amq.2021.01 boulbes n., van asperen e.n. (2019) biostratigraphy and palaeoecology of european equus. frontiers in ecology and evolution, 7, 301. breda m., lister a. (2013) dama roberti, a new species of deer from the early middle pleistocene of europe, and the origins of modern. quaternary science reviews, 69, 155-167. breda m., peretto c., thun hohenstein u. (2015) the deer from the early middle pleistocene site of isernia la pineta (molise, italy): revised identifications and new remains from the last 15 years of excavation. geological journal, 50(3), 290-305. doi: 10.1002/gj.2646 brugal j.-p., giuliani c., fosse p., fourvel j.-b., magniez p., pelletier m., uzunidis a. (2021) preliminary data on the middle pleistocene site of lunel-viel i (hérault, france). alpine and mediterranean quaternary, 34(1), 75-88.. bruner e., manzi g. (2006) saccopastore 1: the earliest neanderthal? a new look at an old cranium. in: neanderthals revisited: new approaches and perspectives (ed. by hublin j.j., harvati k., harrison t.). springer, dordrecht, 23-36. bruner e., manzi g. (2008) paleoneurology of an “early” neandertal: endocranial size, shape, and features of saccopastore 1. journal of human evolution, 54(6), 729-742. buzi c., di vincenzo f., profico a., manzi g. (2021) the pre-modern human fossil record in italy from the middle to the late pleistocene: an updated reappraisal. alpine and mediterranean quaternary, 34(1), 17-32.. doi: 10.26382/amq.2021.03 caloi l., palombo m.r. (1983) resti di mammiferi in livelli del pleistocene medio inferiore affiorati al km 2 del g.r.a. (roma). bollettino del servizio geologico italiano, 104, 141-156. caloi l., palombo m.r., petronio c. (1980) resti cranici di hippopotamus antiquus (= h. major) e hippopotamus amphibius conservati nel museo di paleontologia dell’università di roma. geologica romana, 19, 91-119. cita m.b., capraro l., ciaranfi n., di stefano e., marino m., rio d., sprovieri r., vai g.b. (2006) calabrian and ionian: a proposal for the definition of mediterranean stages for the lower and middle pleistocene. episodes, 29(2), 107-114. clark p., archer d., pollard d., blum j.d., rial j.a., brovkin v., mix a.c., pisias n.g., roy m. (2006) the middle pleistocene transition: characteristics, mechanisms, and implications for long-term changes in atmospheric pco2. quaternary science reviews, 25, 3150-3184. doi: 10.1016/j.quascirev.2006.07.008 combourieu-nebout n., bertini a., russo-ermolli e., peyron o., klotz s., montade v., fauquette s., allen j., fusco f., goring s., huntley b., joannin s., lebreton v., magri d., martinetto e., orain r., sadori l. (2015) climate changes in the central mediterranean and italian vegetation dynamics since the pliocene. review of palaeobotany and palynology, 218, 127-147. conti j., bellucci l., iurino d.a., strani f., sardella r. (2021) review of the ursus material from fontana ranuccio (middle pleistocene, central italy): new insights on the first occurrence of brown bear in italy. alpine and mediterranean quaternary, 34 (1), 34(1), 55-67. demiguel d., brilha j., alegret l., arenillas i., arz j.a., gilabert v., strani f., valenciano a., villas e., azanza b. (2021) linking geological heritage and geoethics with a particular emphasis on palaeontological heritage: the new concept of ‘palaeontoethics’. geoheritage, 13, 69. doi: 10.1007/s12371-021-00595-3 di stefano g., petronio c. (1992) nuove osservazioni su cervus elaphus acoronatus beninde del pleistocene europeo. bollettino della società paleontologica italiana, 31(3), 295-315. di stefano g., petronio c. (1993) a new cervus elaphus subspecies of middle pleistocene age. neues jahrbuch für geologie und paläontologie, 190(1), 1-18. di stefano g., petronio c. (2002) systematics and evolution of the eurasian plio-pleistocene tribe cervini (artiodactyla, mammalia). geologica romana, 36, 311-334. di stefano g., petronio c., sardella r. (1998) biochrnology of the pleistocene mammal faunas from rome urban area. il quaternario, italian journal of quaternary sciences, 11, 2, 191-199. di vincenzo f., profico a., bernardini f., cerroni v., dreossi d., schlager s., zaio p., benazzi s., 11 an overview of the middle pleistocene in the north mediterranean region https://doi.org/10.1016/j.quascirev.2021.106932 https://doi.org/10.1016/j.quascirev.2021.106932 https://doi.org/10.1016/j.quascirev.2021.106932 https://doi.org/10.1016/j.quascirev.2021.106932 https://doi.org/10.1016/j.quascirev.2021.106932 https://doi.org/10.1016/j.quascirev.2021.106932 https://doi.org/10.1016/j.quascirev.2021.106932 https://doi.org/10.1016/j.quascirev.2021.106932 https://doi.org/10.1016/j.quascirev.2021.106932 https://doi.org/10.1016/j.quascirev.2021.106932 https://doi.org/10.1016/j.quascirev.2021.106932 https://doi.org/10.1016/j.quascirev.2021.106932 https://doi.org/10.1016/j.quascirev.2021.106932 https://doi.org/10.1016/j.quascirev.2021.106932 https://doi.org/10.1016/j.quascirev.2021.106932 https://doi.org/10.1016/j.quascirev.2021.106932 https://doi.org/10.1016/j.quascirev.2021.106932 https://doi.org/10.1016/j.quascirev.2021.106932 https://doi.org/10.1016/j.quascirev.2021.106932 https://doi.org/10.1016/j.quascirev.2021.106932 https://doi.org/10.1016/j.quascirev.2021.106932 https://doi.org/10.1016/j.quascirev.2021.106932 https://doi.org/10.1016/j.quascirev.2021.106932 https://doi.org/10.1016/j.quascirev.2021.106932 https://doi.org/10.1016/j.quascirev.2021.106932 https://doi.org/10.1016/j.quascirev.2021.106932 https://doi.org/10.1016/j.quascirev.2021.106932 https://doi.org/10.1016/j.quascirev.2021.106932 https://doi.org/10.1016/j.quascirev.2021.106932 https://doi.org/10.1016/j.quascirev.2021.106932 https://doi.org/10.1016/j.quascirev.2021.106932 https://doi.org/10.1016/j.quascirev.2021.106932 biddittu i., rubini m., tuniz c., manzi g. (2017) digital reconstruction of the ceprano calvarium (italy), and implications for its interpretation. scientific reports, 7(1), 1-11. di vincenzo f., churchill s.e., buzi c., profico a., tafuri m.a., micheli m., caramelli d., manzi g. (2019) distinct among neanderthals: the scapula of the skeleton from altamura, italy. quaternary science reviews, 217, 76-88. fernandez p., jeannet m., jaubert j., brugal j.-p. (2021) paleoecologial first results on the middle pleistocene sequence of coudoulous i (quercy, lot, france). alpine and mediterranean quaternary, 34(1), 89-108. gallotti r., peretto c. (2015) the lower/early middle pleistocene small débitage productions in western europe: new data from isernia la pineta t.3c (upper volturno basin, italy). quaternary international, 357, 264-281. doi: 10.1016/j.quaint.2014.06.055 gliozzi e., abbazzi l., argenti p., azzaroli a., caloi l., capasso barbato l., di stefano g., esu d., ficcarelli g., girotti o., kotsakis t., masini f., mazza p., mezzabotta c., palombo m.r., petronio c., rook l., sala b., sardella r., zanalda e., torre d. (1997) biochronology of selected mammals, molluscs and ostracods from the middle pliocene to the late pleistocene in italy. the state of the art. rivista italiana di paleontologia e stratigrafia, 103, 369-388. doi: 10.13130/2039-4942/5299 gibbard p.l., head m.j. (2010) the newly-ratified definition of the quaternary system/period and redefinition of the pleistocene series/epoch, and comparison of proposals advanced prior to formal ratification. episodes, 33, 152-158. grimaldi s., santaniello f., angelucci d.e., bruni l., parenti f. (2020) a techno-functional interpretation of the lithic assemblage from fontana ranuccio (anagni, central italy): an insight into a mis 11 human behaviour. journal of paleolithic archaeology, 3(4), 944-966. head m.j., gibbard p.l. (2015) early-middle pleistocene transitions: linking terrestrial and marine realms. quaternary international, 389, 7-46. doi: 10.1016/j.quaint.2015.09.042 iannucci a., mecozzi b., sardella r. (2021) large mammals from the middle pleistocene (mis 11) site of fontignano 2 (rome, central italy), with an overview of “san cosimato” assemblages. alpine and mediterranean quaternary, 34(1), 155-164. doi: 10.26382/amq.2021.07 kahlke r.d. (1999) the history of the origin, evolution and dispersal of the late pleistocene mammuthus -coelodonta faunal complex in eurasia (large mammals). fenske companies, rapid city. kahlke r.d. (2009) les communautés de grands mammiféres du pléistocéne inférieur terminal et le concept d'un biochrone epivillafranchien. quaternaire 20 (4), 415-427. kahlke r.d., garcía n., kostopoulos d.s., lacombat f., lister a.m., mazza p.p.a., spassov n., titov v.v. (2011) western palaearctic palaeoenvironmental conditions during the early and early middle pleistocene inferred from large mammal communities, and implications for hominin dispersal in europe. quaternary science reviews, 30, 1368-1395. kuitems m., van der plicht j., drucker d.g., van kolfschoten t., palstra s.w., bocherens h. (2015) carbon and nitrogen stable isotopes of wellpreserved middle pleistocene bone collagen from schöningen (germany) and their paleoecological implications. journal of human evolution, 89, 105113. lari m., di vincenzo f., borsato a., ghirotto s., micheli m., balsamo c., collina c., de bellis g., frisia s., giacobini g., gigli e., hellstrom j.c., lannino a., modi a., pietrelli a., pilli e., profico a., ramirez o., rizzi e., vai s., venturo d., piperno m., laluezafox c., barbujani g., caramelli d., manzi g. (2015) the neanderthal in the karst: first dating, morphometric, and paleogenetic data on the fossil skeleton from altamura (italy). journal of human evolution, 82, 88-94. leonardi g., petronio c. (1974) i cervi pleistocenici del bacino diatomitico di riano (roma). memorie dell’accademia nazionale dei lincei, 12, 103-208. magri d., palombo m.r. (2013) early to middle pleistocene dynamics of plant and mammal communities in south west europe. quaternary international, 288, 63-72. malinsky-buller (2016) lost and found: technological trajectories within lower/middle paleolithic transition in western europe, north of the pyrenees. quaternary international, 409, 104-148. manzi g. (2016) humans of the middle pleistocene: the controversial calvarium from ceprano (italy) and its significance for the origin and variability of homo heidelbergensis. quaternary international 411, 254-261. manzi g., mallegni f., ascenzi a. (2001) a cranium for the earliest europeans: phylogenetic position of the hominid from ceprano, italy. proceedings of the national academy of sciences, 98(17), 1001110016. manzi g., magri d., palombo m.r. (2011) early-middle pleistocene environmental changes and human evolution in the italian peninsula. quaternary science reviews, 30(11-12), 1420-1438. marano f., palombo m.r., cerilli e., milli s. (2021). the fossilization of mammal bones at la polledrara di cecanibbio (rome, central italy). insights for in situ preservation. alpine and mediterranean quaternary, 34(1), 165-180. marra f., pandolfi l., petronio c., di stefano g., gaeta m., salari l. (2014) reassessing the sedimentary deposits and vertebrate assemblages from ponte galeria area (rome, central italy): an archive for the middle pleistocene faunas of europe. earth science reviews, 139, 104-122. marra f., ceruleo p., jicha b., pandolfi l., petronio c., salari l. (2015) a new age within mis 7 for the homo neanderthalensis of saccopastore in the glacio-eustatically forced sedimentary successions of the aniene river valley, rome. quaternary science reviews, 129, 260-274. 12 strani f. et al. martinez-navarro b., palombo m.r. (2007) the horncore of hemibos galerianus from ponte milvio, rome (italy). rivista italiana di paleontologia e stratigrafia, 113(3), 531-534. maslin m.a., brierley c.m. (2015) the role of orbital forcing in the early middle pleistocene transition. quaternary international, 389, 47-55. doi: 10.1016/j.quaint.2015.01.047 mazza p.p.a. (1991) interrelations between pleistocene hippopotami of europe and africa. bollettino della società paleontologica italiana, 30, 153-186. mazza p.p.a. (1995) new evidence on the pleistocene hippopotamuses of western europe. geologica romana, 31, 61-241. mazza p.p.a., bertini a. (2013) were pleistocene hippopotamuses exposed to climate-driven body size changes? boreas, 42, 194-209. mecozzi b. (2021) meles meles from middle pleistocene to early holocene of the italian peninsula within the evolution of european badgers in the quaternary of eurasia. palaeontographica, abt. a.: palaeozoology stratigraphy, in press. doi: 10.1127/pala/2021/0100 mecozzi b., strani f. (2021) equids from the late middle pleistocene to early holocene of the apulia peninsula (southern italy): reassessment of their taxonomy and biochronology. geodiversitas, in press. mecozzi b., iurino d.a., berte d.f., sardella r. (2017) canis mosbachensis (canidae, mammalia) from the middle pleistocene of contrada monticelli (putignano, apulia, southern italy). bollettino della società paleontologica italiana, 56, 71-78. mecozzi b., iurino d.a., profico a., rosa c., sardella r. (2020a) the wolf from the middle pleistocene site of ostiense (rome): the last occurrence of canis mosbachensis (canidae, mammalia) in italy, historical biology, in press. doi: 10.1080/08912963.2020.1769090 mecozzi b., bartolini lucenti s., iurino d.a. (2020b) cuon alpinus (pallas, 1811) from the late pleistocene site of ingarano (foggia, southern italy) and insights on the eurasian middle to late pleistocene record. alpine and mediterranean quaternary, 33(1), 89-98. mecozzi b., iannucci a., bona f., mazzini i., pieruccini p., sardella r. (2021a) rediscovering lutra lutra from grotta romanelli (southern italy) in the framework of the puzzling evolutionary history of eurasian otter. paläontologische zeitschrift, in press. doi: 10.1007/s12542-021-00553-y mecozzi b., bellucci l., giustini f., iannucci a., iurino d.a., mazzini i., strani f., sardella r. (2021b) a reappraisal of the pleistocene mammals from the karst infilling deposits of the maglie area (lecce, apulia, southern italy). rivista italiana di paleontologia e stratigrafia, 127(2), 333-360. mecozzi b., iannucci a., sardella r., curci a., daujeard c., moncel m.-h. (2021c) macaca ulna from new excavations at the notarchirico acheulean site (middle pleistocene, venosa, southern italy). journal of human evolution, 153, 102946. doi: 10.1016/j.jhevol.2020.102946 mecozzi b., sardella r., boscaini a., cherin m., costeur l., madurell-malapeira j., pavia m., profico a., iurino d.a. (2021d) the tale of a short-tailed cat: new outstanding late pleistocene fossils of lynx pardinus from southern italy. quaternary science reviews, 106840. doi: 10.1016/j.quascirev.2021.106840 mecozzi b., iannucci a., mancini m., sardella r. (2021e) redefining ponte molle (rome, central italy): an important locality for middle pleistocene mammal assemblages of europe. alpine and mediterranean quaternary, 34(1), 131-154. milli s., palombo m.r., petronio c., sardella r. (2004) mammal biochrology and sequence stratigraphy of the middle-upper pleistocene deposits of the roman basin (latium, italy): an integrated approach. rivista italiana di paleontologia e stratigrafia, 110(2), 559-569. moigne a.m., palombo m.r., belda v., heriech-briki d., kacimi s., lacombat f., de lumley m.a., moutoussamy j., rivals f., quilès j., testu a. (2006) les faunes de grands mammifères de la caune de l'arago (tautavel) dans le cadre biochronologique des faunes du pléistocène moyen italien. l'anthropologie, 110(5), 788-831. moncel m.-h., santagata s., pereira a., nomade s., bahain j.-j., voinchet p., piperno m. (2019) a biface production older than 600 ka ago at notarchirico (southern italy) contribution to understanding early acheulean cognition and skills in europe. plos one, 14(10), e0218591. doi: 10.1371/journal.pone.0218591 moncel m.-h., santagata c., pereira a., nomade s., voinchet p., bahain j.-j., daujeard c., curci a., lemorini c., hardy b., eramo g., berto c., raynal j.-p., arzarello m., mecozzi b., iannucci a., sardella r., allegretta i., delluniversità e., terzano r., dugas p., jouanic g., queffelec a., d’andrea a., valentini r., minucci e., carpentiero l., piperno m. (2020a) the origin of early acheulean expansion in europe 700 ka ago: new findings at notarchirico (italy). scientific reports, 10(1), 1-16. moncel m.-h., ashton n., arzarello m., fontana f., lamotte a., scott b., muttillo b., berruti g., nenzioni g., tuffreau a., peretto c. (2020b) early levallois core technology between marine isotope stage 12 and 9 in western europe. journal of human evolution, 139, 102735. muttillo b., lembo g., gallotti r. (2021) lithic productions during the first half of the middle pleistocene (mis 19-12) in the italian peninsula: an overview. alpine and mediterranean quaternary, 34(1), 3354. doi: 10.26382/amq.2021.05 palombo m.r., sardella r. (2007) biochronology and biochron boundaries: a real dilemma or a false problem? an example based on the pleistocene large mammalian faunas from italy. quaternary international, 160, 30-42. palombo m.r., azanza b., alberdi m.t. (2002) italian mammal biochronlogy from the latest miocene to the middle pleistocene: a multivariate approach. 13 an overview of the middle pleistocene in the north mediterranean region https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 https://doi.org/10.1016/j.jhevol.2020.102946 14 strani f. et al. geologica romana, 36, 335-368. palombo m.r., valli a.m.f. (2004) remarks on the biochronology of mammalian faunal complexes from the pliocene to the middle pleistocene in france. geologica romana, 37, 145-163. palombo m.r., sardella r., novelli m. (2008) carnivora dispersal in western mediterranean during the last 2.6 ma. quaternary international, 179, 176189. palombo m.r., alberdi m.t., azanza b., giovinazzo c., prado j.l., sardella r. (2009) how did environmental disturbances affect carnivoran diversity? a case study of the plio-pleistocene carnivora of the north-western mediterranean. evolutionary ecology, 23, 569-589. pandolfi l. (2013) rhinocerotidae (mammalia, perissodactyla) from the middle pleistocene site of ponte milvio, central italy. bollettino della società paleontologica italiana, 52(3), 219-229. pandolfi l., marra f. (2015) rhinocerotidae (mammalia, perissodactyla) from the chronostratigraphically constrained pleistocene deposits of the urban area of rome (central italy). geobios, 48(2), 147-167. pandolfi l., fiore i., gaeta m., szabó p., vennemann t., tagliacozzo a. (2018) rhinocerotidae (mammalia, perissodactyla) from the middle pleistocene levels of grotta romanelli (lecce, southern italy). geobios, 51(5), 453-468. pereira a., nomade s., moncel m., voinchet p., bahain j., biddittu i., falguères c., giaccio b., manzi g., parenti f., scardia g., scao v., sottili g., vietti a. (2018) integrated geochronology of acheulian sites from the southern latium (central italy): insights on human-environment interaction and the technological innovations during the mis 11-mis 10 period. quaternary science reviews, 187, 112129. peretto c., arnaud j., moggi-cecchi j., manzi g., nomade s., pereira a., falguères c., bahain j.-j., grimaud-hervé d., berto c., sala b., lembo g., muttillo b., gallotti r., hohenstein u.t., vaccaro c., coltorti m., arzarello m. (2015) a human deciduous tooth and new 40ar/39ar dating results from the middle pleistocene archaeological site of isernia la pineta, southern italy. plos one, 10 (10), e0140091. petronio c., sardella r. (1998) bos galerianus n. sp. (bovidae, mammalia) from ponte galeria formation (rome, italy). neues jahrbuch für geologie und paläontologie, 5, 289-300. petronio c., sardella r. (1999) biochronology of the pleistocene mammal fauna from ponte galeria (rome) and remarks on the middle galerian faunas. rivista italiana di paleontologia e stratigrafia, 105, 155-164. petronio c., bellucci l., martiinetto e., pandolfi l., salari l. (2011) biochronology and palaeoenvironmental changes from the middle pliocene to the late pleistocene in central italy. geodiversitas, 33(3), 485-517. picin a. (2017) technological adaptation and the emergence of levallois in central europe: new insight from the markkleeberg and zwochau openair sites in germany. journal of quaternary sciences, 33, 300-312. pushkina d., saarinen j., ziegler r., bocherens h. (2020) stable isotopic and mesowear reconstructions of paleodiet and habitat of the middle and late pleistocene mammals in south-western germany. quaternary science reviews, 227, 106026. doi: 10.1016/j.quascirev.2019.106026 rivals f. (2012) ungulate feeding ecology and middle pleistocene paleoenvironments at hundsheim and deutsch-altenburg 1 (eastern austria). palaeogeography, palaeoclimatology, palaeoecology, 317318, 27-31. rivals f., schulz e., kaiser t.m. (2009) late and middle pleistocene ungulates dietary diversity in western europe indicate variations of neanderthal paleoenvironments through time and space. quaternary science reviews, 28(27-28), 3388-3400. rocca r., aureli d., abruzzese c. (2018) cimitero di atella. nouvelles recherches et valorisation d’un gisement du paléolithique ancien en méditerranée. chronique des activités archéologiques de l’école française de rome. doi: 10.4000/cefr.1910 rocca r., aureli d. (2020) cimitero di atella: résultats de la mission 2019. chronique des activités archéologiques de l’école française de rome. doi: 10.4000/cefr.3329 romano m., mecozzi b., sardella r. (2021) the quaternary paleontological research in the campagna romana (central italy) at the 19th-20th century transition: historical overview. alpine and mediterranean quaternary, 34(1), 109-130. doi: 10.26382/amq.2021.06 rubini m., cerroni v., festa g., sardella r., zaio p. (2014) a revision of hominin fossil teeth from fontana ranuccio (middle pleistocene, anagni, frosinone, italy). journal of human evolution, 77, 204-216. russo ermolli e., sardella r., di maio g., petronio c., santangelo n. (2010a) pollen and mammals from the late early pleistocene site of saticula (sant'agata de'goti, benevento, italy). quaternary international, 225(1), 128-137. russo ermolli e., aucelli p.p.c., di rollo a., mattei m., petrosino p., porreca m., rosskopf c.m. (2010b) an integrated stratigraphical approach to the middle pleistocene succession of the sessano basin (molise, italy). quaternary international, 225(1), 114-127. saarinen j., cirilli o., strani f., meshida k., bernor r.l. (2021) testing equid body mass estimate equations on modern zebras-with implications to understanding the relationship of body size, diet, and habitats of equus in the pleistocene of europe. frontiers in ecology and evolution, 9, 622412. doi: 10.3389/fevo.2021.622412 sardella r. (2007) vertebrate records, mid-pleistocene of europe. encyclopedia of quaternary science, 4, 3224-3232. sardella r., palombo m.r. (2007) the pliocene 15 an overview of the middle pleistocene in the north mediterranean region pleistocene boundary: which significance for the so called “wolf event”? evidences from western europe. quaternaire, 18(1), 63-69. sardella r., palombo m.r., petronio c., bedetti c., pavia m. (2006) the early middle pleistocene large mammal faunas of italy: an overview. quaternary international, 149, 104-109. sardella r., petrucci m. (2012) the earliest middle pleistocene crocuta crocuta (erxleben, 1777) at casal selce (rome, italy). quaternary international, 267, 103-110. sardella r., bedetti c., iurino d.a., pavia m., bellucci l. (2015) comment on “reassessing the sedimentary deposits and vertebrate assemblages from ponte galeria area (rome, central italy): an archive for the middle pleistocene faunas of europe” by f. marra, l. pandolfi, c. petronio, g. di stefano, m. gaeta and l. salari [earth-science reviews 139(2014), 104-122]. earth-science reviews, 147, 2011-2013. sardella r., mazzini i., giustini f., mecozzi b., brilli m., iurino d.a., lembo g., muttillo b., massussi m., sigari d., tucci s., voltaggio m. (2018) grotta romanelli (southern italy, apulia): legacies and issues in excavating a key site for the pleistocene of the mediterranean. rivista italiana di palentologia e stratigrafia, 12, 247-264. sardella r., iurino d.a., mecozzi b., sigari d., bona f., bellucci l., coltorti m., conti j., lembo g., muttillo b., mazzini i. (2019) grotta romanelli (lecce, southern italy) between past and future: new studies and perspectives for an archaeo-geosite symbol of the palaeolithic in europe. geoheritage, 11 (4), 1413-1432. doi: 10.1007/s12371-019-00376-z scott g.r., gibert l. (2009) the oldest hand-axes in europe. nature, 461(7260), 82-85. segre a.g., ascenzi a. (1984) fontana ranuccio: italy's earlyest middle pleistocene hominid site. current anthropology 25 (2), 230–233. sergi s. (1944) craniometria e craniografia del primo paleantropo di saccopastore. ricerche di morfologia, 20/21, 733-791. sergi s. (1948) the palaeanthropi in italy: the fossil men of saccopastore and circeo. man, 48, 6164/76-79. sergi s. (1962) the neanderthal palaeanthropi in italy. in: ideas on human evolution, selected essays 1949-1961 (ed. by howells w.w.). harvard university press, cambridge (ma), pp. 500-506. stefanelli d., mecozzi b., francescangeli r., girone a., marino m., montenegro v., sardella r., breda m. (2021) the fallow deer from contrada monticelli (bari, southern italy): the southernmost occurrence of a large dama of the early middle pleistocene. bollettino della società paleontologica italiana, 60, 55-60. doi: 10.4435/bspi.2021.02. strani f. (2020) impact of early and middle pleistocene major climatic events on the palaeoecology of southern european ungulates. historical biology, in press. doi: 10.1080/08912963.2020.1782898 strani f., de miguel d., bona f., sardella r., biddittu i., bruni l., de castro a., guadagnoli f., bellucci l. (2018) ungulate dietary adaptations and palaeoecology of the middle pleistocene site of fontana ranuccio (anagni, central italy). palaeogeography palaeoclimatolology palaeoecology, 496, 238-247. strani f., pushkina d., bocherens h., bellucci l., sardella r., demiguel d. (2019) dietary adaptations of early and middle pleistocene equids from the anagni basin (frosinone, central italy). frontiers in ecology and evolution, 7, 176. doi: 10.3389/fevo.2019.00176 strani f., bellucci l., iannucci a., iurino d.a., mecozzi b., sardella r. (2021) palaeoenvironments of the mis 15 site of cava di breccia casal selce 2 (central italian peninsula) and niche occupation of fossil ungulates during middle pleistocene interglacials. historical biology, in press. doi: 10.1080/08912963.2021.1935920 suganuma y., okada m., head m.j., kameo k., haneda y., hayashi h., irizuki t., itaki t., izumi k., kubota y., nakazato h., nishida n., okuda m., satoguchi y., simon q., takeshita y. (2021) formal ratification of the global boundary stratotype section and point (gssp) for the chibanian stage and middle pleistocene subseries of the quaternary system: the chiba section, japan†. episodes, 1-31. doi: 10.18814/epiiugs/2020/020080 van der made j., sahnouni m., boulaghraief k. (2017) hippopotamus gorgops from el kherba (algeria) and the context of its biogeography. in: proceedings of the ii meeting of african prehistory: burgos 15-16 april, 2015 (ed. by sahnouni m., semaw s., rios garalzar j.). consorcio cenieh, burgos, 135-169. villa p., soriano s., grün r., marra f., nomade s., pereira a., boschian g., pollarolo l., fang f., bahain j.-j. (2016) the acheulian and early middle paleolithic in latium (italy): stability and innovation. plos one, 11, e0160516. wiśniewski a. (2014) the beginnings and diversity of levallois methods in the early middle palaeolithic of central europe. quaternary international, 326327, 364-380. zanolli c., martinón-torres m., bernardini f., boschian g., coppa a., dreossi d., mancini l., martínez de pinillos m., martín-francés l., bermúdez de castro j.m., tozzi c., tuniz c., macchiarelli r. (2018) the middle pleistocene (mis 12) human dental remains from fontana ranuccio (latium) and visogliano (friuli-venezia giulia), italy. a comparative high resolution endostructural assessment. plos one, 13(10), e0189773. ms. received: may 4, 2021 revised: june 2, 2021 accepted: june 22, 2021 available online: july 3, 2021 16 amq abs marino et al palcom 151-154.pub available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 151 154 the climate variability during marine isotope stage 19: evidences from a west-east mediterranean transect maria marino 1, franck bassinot 2, adele bertini 3, salvatore gallicchio 1, angela girone 1, timothy herbert 4, patrizia maiorano 1, sebastien nomade 2, paola petrosino 5, ornella quivelli 1, teresa rodrigues 6, francesco toti 3, neri ciaranfi 1 1 dipartimento di scienze della terra e geoambientali, università degli studi di bari, bari, italy 2 laboratoire des sciences du climat et de l’environnement, gif-sur-yvette, france 3 dipartimento di scienze della terra, università degli studi di firenze, firenze, italy 4 department of earth, environmental & planetary sciences, brown university, providence, usa 5 dipartimento di scienze della terra dell'ambiente e delle risorse, università degli studi di napoli federico ii, napoli, italy 6instituto portugues do mar e da atmosfera, lisboa, portugal corresponding author: m. marino <maria.marino@uniba.it > abstract: new high temporal resolution data on calcareous nannofossil and planktonic foraminifera assemblages, alkenone-derived sea surface temperature and stable oxygen and carbon isotopes are acquired on the montalbano ideale section (southern italy) and at the ocean drilling program (odp) sites 975 and 976 through marine isotope stages (mis) 20-18. results describe accurate climate pattern and distinct orbital-suborbital up to millennia-scale oscillations across the investigated interval. keywords: mis 19, calcareous plankton, sst, pollen, stable oxygen and carbon isotopes, mediterranean 1. introduction mis 19 is the mid-pleistocene interglacial considered the best analogue of mis 1 due to their similar orbital configuration (extraordinarily low eccentricity and obliquity maximum close to the precession minimum) and (paleo)climate signal (tzedakis et al., 2012). a strong likeness between the climate trends through termination ix (i) and the onset of full interglacial 19 (1) has been recently suggested (maiorano et al., 2016) based on marine and terrestrial biological proxies at the inland marine succession of montalbano jonico. several issues are however still debated, mainly concerning i) the beginning of mis 19, as recorded by oxygen isotope records or biological proxies, ii) the duration of mis 19c (full interglacial), iii) the mode and timing of glacial mis 18 inception. with the aim to improve the comprehension of climate evolution through this crucial time interval, which includes the chronostratigraphic boundary of the lower-middle pleistocene, new investigations are carried out on the montalbano jonico section (southern italy). it is a continuous reference succession for the lower-middle pleistocene transition spanning mis 37-16 interval. in particular, the ideale partial section yet relies on an exceptional multi-proxy high-resolution data set across termination ix to the inception of mis 18 (fig. 1a) (maiorano et al., 2016). the authigenic 10be/9be data (simon et al., 2017) and 40ar/39ar age for tephra layer v4 (773.9 ±1.3 ka, petrosino et al., 2015) at the mis 19c/19b transition in the ideale section (fig. 1a) represent additional invaluable stratigraphical constraints within the matuyama-brunhes transitional period. moreover, new studies are performed at the western mediterranean odp site 976 (alboran sea) and site 975 (algero-balearic sea) (fig. 1b) in order to have a westeast record of the climate variability during mis 19 in the mediterranean basin. 2. material and method the montalbano jonico ideale section (southern italy) is 74 meters thick and consists of dark-light grey silty clays. the sediments from the odp sites 976 and 975 consist of nannofossil and foraminifera-rich clays. high-resolution quantitative analyses were performed on calcareous plankton assemblages, in the same samples used to measure the new stable oxygen and carbon isotope ratios carried out on melonis barleeanum and cassidulina carinata at the montalbano jonico section, and on globigerina bulloides at the sites 975 and 976. isotope analyses at the site 975 are still in progress whereas alkenone analyses were performed at the balearic core as well as at the montalbano jonico ideale section with the aim to obtain high-resolution sea surface temperature (sst) and signals of terrestrial molecular biomarkers strictly linked to climate on land and hydrological setting. https://doi.org/10.26382/aiqua.2018.aiquaconference 152 marino m. et al. fig. 1 a) main chronological and environmental constraints at the montalbano jonico ideale section. pc1 curves represent factor 1 obtained by principal component analysis performed on planktonic foraminifera and calcareous nannofossils, and on benthic foraminifera. b) location map of the study successions. 153 3. results an original astronomical tuning of the δ18o record, adjusted by the radiometric dating of tephra v4, is performed at the ideale section, using the strong analogies between mis 1 and mis 19c in terms of orbital forcing and co2 level (nomade et al., submitted). the overall results reveal a distinct climate pattern of mis 19c and at least three millennial-scale oscillations (ii-iiii, fig. 1a) superimposed on the long-term drying and cooling trend leading to mis 18 taking place in one single precession cycle, suggesting a non-linear response of western mediterranean climate to orbital forcing during this period (i.e. mis 19a). results from site 976 and site 975 (fig. 1b) further improve the knowledge on the mode and timing of the climate phases during mis 20-18. in detail, the δ18o records from the deep sea undisturbed sections clearly depict stages and substages, and stadial and interstadials, which are in excellent agreement with climate oscillations documented by the isotope and biological data at the montalbano jonico ideale section. key taxa of calcareous plankton assemblages record distinctive patterns that are mainly related to sea-surface water temperature changes and to water exchange rates between atlantic ocean and mediterranean during glacial (mis 20)-interglacial (mis 19) phases and short-term climate episodes at the termination ix. variations in turbidity and salinity as well as mixing and stratification or nutrient content in the sea surface waters have been reconstructed based on the pattern of selected coccolithophore and planktonic foraminifera taxa. among pollen assemblages, the mediterranean/temperate broad-leaved deciduous forest taxa exhibit higher abundances during interglacials and interstadials (bertini et al., 2015) when warm-water calcareous plankton taxa increase (fig. 1a). while, the expansion of steppes and semi-desert vegetation cover, as well as the incursion of polarsubpolar calcareous plankton taxa, occur during cooler periods possibly associated to atmospheric and north hemisphere ice-sheet dynamics. shorter-lived climate changes are also detectable at the millennial time-scale. in the montalbano ideale record, unequivocal evidence of the shallow water analog of ghost sapropel i-cycle 74 (784 ka) has been documented based on minima in δ13c and δ18o, and the occurrence of planktonic and benthic invertebrate taxa indicating water column stratification and oxygen deficiency at the sea bottom (maiorano et al., 2016; nomade et al., submitted). similar results occur at the site 975, whereas such palaeoceanographic event is not recorded at site 976 in the alboran sea, thus highlighting a different response to precessional forcing of the surface and deeper water masse hydrological pattern in the westernmost mediterranean. 4. discussion and conclusion the correlation among the different study sections enables to compare the response of marine (coccolithophores and planktonic foraminifera) and terrestrial proxies to climate changes through a west east transect, in different hydrological regimes of mediterranean. as a whole, the climate pattern observed at the montalbano jonico ideale section and deep-sea cores is well comparable to the synthetic greenland temperature curve (barker et al., 2011) and antarctic ice core deuterium record (jouzel et al., 2007), highlighting the interconnection between the north atlantic and the mediterranean climate during mis 19 and the global scale correlation of events and phases. references aiello g., barra d., parisi r. (2015) lower-middle pleistocene ostracod assemblages from the montalbano jonico section (basilicata, southern italy). quaternary international, 383, 47-73. barker, s., knorr, g., edwards, r.l., rarrenin, f., putnam, a.e., skinner, l.c., wolff, e., ziegler, m. (2011) 800,000 years of abrupt climate variability. science 334, 347-351. bertini a., toti f., marino m., ciaranfi n. (2015) vegetation and climate across the early-middle pleistocene transition at the montalbano jonico section (southern italy). quaternary international, 383, 7488. ciaranfi, n., lirer, f., lirer, l., lourens, l.j., maiorano, p., marino, m., petrosino, p., sprovieri, m., stefanelli, s., brilli, m., girone, a., joannin, s., pelosi, n., vallefuoco, m. (2010) integrated stratigraphy and astronomical tuning of the lower-middle pleistocene montalbano jonico land section (southern italy). quaternary international, 210, 109-120. maiorano p., marino m., di stefano e., ciaranfi n. (2004) calcareous nannofossil events in the lower-middle pleistocene transition at the montalbano jonico section and odp site 964: calibration with isotope and sapropel stratigraphy. rivista italiana di paleontologia e stratigrafia, 110, 547557. maiorano p., capotondi l., ciaranfi n., girone a., lirer f., marino m., pelosi n., petrosino p., piscitelli a. (2010) vrica-crotone and montalbano jonico sections: a potential unit-stratotype of the calabrian stage. episodes, 33, 218-233. marino m., bertini a., ciaranfi n., aiello g., barra d., gallicchio s., girone a., la perna r., lirer f., maiorano p., petrosino p., toti f. (2015) paleoenvironmental and climatostratigraphic insights for marine isotope stage 19 (pleistocene) at the montalbano jonico section, south italy. quaternary international, 383, 104-115. nomade s., bassinot f., marino m., maiorano p., dewilde f., esguder g., pereira a., blamart d., girone a., scao v., toti f., bertini a., simon q., combourieu-nebout n., bourles d., ciaranfi n. (submitted) high-resolution foraminifer stable isotope record of mis 19 at montalbano jonico, southern italy: a window into mediterranean climatic variability during a low-excentricity interglacial and the early-middle pleistocene transition. quaternary science reviews. jouzel j., masson-delmotte v., cattani o., dreyfus g., falourd s., hoffmann g., minster b., nouet j., barnola j.m., chappellaz j., fischer h., gallet mis 19 climate changes: evidences from the mediterranean basin j.c., johnsen s., leuenberger m., loulergue l., luethi d., oerter h., parrenin f., raisbeck g., raynaud d., schilt a., schwander j., selmo e., souchez r., spahni r., stauffer b., steffensen j.p., stenni b., stocker t.f., tison j.l., werner m., wolff e.w. (2007) orbital and millennial antarctic climate variability over the past 800,000 years. science, 317, 793-796. maiorano p., bertini a., capolongo d., eramo g., gallicchio s., girone a., pinto d., toti f., ventruti g., marino m. (2016) climate signatures through the marine isotope stage 19 in the montalbano jonico section (southern italy): a land-sea perspective. palaeogeography, palaeoclimatology, palaeoecology, 461, 341-361. petrosino p., jicha b.r., mazzeo f.c., ciaranfi n., girone a., maiorano p., marino m. (2015) the montalbano jonico marine succession: an archive for distal tephra layers at the early-middle pleistocene boundary in southern italy. quaternary international, 383, 89-103. simon q., bourlès l.d., bassinot f., nomade s., marino m., ciaranfi n., girone a., maiorano p., thouveny n., choya s., dewil f., scao v., isguder g., blamart d., aster team (2017) authigenic 10be/9be ratio signature of the matuyama-brunhes boundary in the montalbano jonico marine succession. earth and planetary science letters, 460, 255-267. stefanelli s. (2003) benthic foraminiferal assemblages as tools for paleoenvironmental reconstruction of the early-middle pleistocene montalbano jonico composite section. bollettino della società paleontologica italiana, 42, 281-299. tzedakis p.c., channell j.e.t., hodell d.a., kleiven h.f., skinner l.c. (2012) determining the natural length of the current interglacial. nat. geosci, 5, 138-141. 154 marino m. et al. ms. received: may 11, 2018 final text received: may 17, 2018 microsoft word 00_indice_lm04.docx il quaternario it issn 039-3356 italian journal of quaternary sciences 24 (1), 2011 75-92 a revision of the “northern guest” ostracoda (crustacea) occurrence in the quaternary of the mediterranean area costanza faranda1 & elsa gliozzi1,2 1dipartimento di scienze geologiche, università degli studi roma tre, roma 2 istituto di geologia ambientale e geoingegneria, cnr, roma corresponding author: e. gliozzi <gliozzi@uniroma3.it> abstract: faranda c. & gliozzi e., a revision of the “northern guest” ostracoda (crustacea) occurrence in the quaternary of the mediterranean area. in this paper the revision of the “northern guest” ostracods widespread in the mediterranean area during quaternary time is proposed. the abundant literature on this topic lists up to twenty-three species. they have been critically revised and a list of only twelve true “northern guests” is provided: acanthocythereis dunelmensis (norman, 1865), bythocythere turgida sars, 1866, bythocythere zetlandica athersuch, horne & whittaker, 1983, cythere lutea müller 1785, cytheropteron depressum (brady & norman, 1889), cytheropteron punctatum brady, 1868, cytheropteron testudo sars, 1870, hemicythere villosa (sars, 1865), paradoxostoma abbreviatum sars, 1866, paradoxostoma ensiforme brady, 1866, paradoxostoma tenuissimum (norman, 1869) and semicytherura angulata (brady, 1868). these species are generally rare, being found with very few specimens and mainly in one locality. only cytheropteron testudo and cytheropteron punctatum have been reported with a wide geographical distribution in italy and in the aegean sea. the twelve “northern guest” ostracods entered the mediterranean at different times, being more abundant in the early pleistocene sicilian substage. only one study on the last glacial maximum marine ostracods has been carried out recording the presence of c. testudo. the record of loose valves of “cold” ostracod species (c. testudo, p. tenuissimum and b. turgida) among the living mediterranean assemblages suggests that they could have migrated into the mediterranean even during late pleistocene time. in this paper, a critical revision of the existing literature about “northern guest” ostracods is presented, together with their stratigraphical and geographical distribution in the mediterranean, and three new “northern guest” ostracod species are added. riassunto. faranda c. & gliozzi e., revisione della presenza dell’ospite freddo ostracoda (crustacea) nel quaternario dell’area mediterranea. in questo lavoro viene proposta la revisione critica degli ostracodi “ospiti nordici” che si diffusero nel mediterraneo durante le fasi climatiche fredde che caratterizzarono il quaternario. l’abbondante, seppure frammentaria letteratura esistente su questo argomento, elenca ventitrè specie di ospiti nordici; in seguito alla presente revisione questo numero è ridotto a sole dodici specie di ostracodi che possono essere considerati veri “ospiti nordici”: acanthocythereis dunelmensis (norman, 1865), bythocythere turgida sars, 1866, bythocythere zetlandica athersuch, horne & whittaker, 1983, cythere lutea müller 1785, cytheropteron depressum (brady & norman, 1889), cytheropteron punctatum brady, 1868, cytheropteron testudo sars, 1870, hemicythere villosa (sars, 1865), paradoxostoma abbreviatum sars, 1866, paradoxostoma ensiforme brady, 1866, paradoxostoma tenuissimum (norman, 1869) e semicytherura angulata (brady, 1868). queste specie sono generalmente rare sia nelle associazioni, dove spesso sono rappresentate da pochissime valve, sia come presenza nell’area mediterranea, essendo prevalentemente segnalate in una sola località. solo cytheropteron testudo e cytheropteron punctatum sembrano avere una distribuzione geografica piuttosto ampia, sia nel mediterraneo centrale (italia) sia in quello orientale (mare egeo). le dodici specie di ostracodi “ospiti nordici” migrarono nel mediterraneo in tempi quaternari diversi e risultano più abbondanti in corrispondenza del sottopiano siciliano. l’unico studio sulle ostracofaune marine dell’ultimo pleniglaciale ha permesso di registrare la presenza di c. testudo anche nella parte alta del quaternario. e’ possibile che a questa specie ne possano venire aggiunte almeno altre due (p. tenuissimum and b. turgida) le cui valve isolate, prive di parti molli, sono state rinvenute nei fondali del mediterraneo insieme ad ostracofaune viventi. keywords: marine ostracods, northern guests, mediterranean, quaternary, stratigraphic distribution. parole-chiave: ostracodi marini. ospiti nordici, mediterraneo, quaternario, distribuzione stratigrafica. 1. introduction at the 18th international geological congress (london, 1948), the lower boundary of the quaternary era (tertiary/quaternary boundary) was established “at the horizon of the first indication of the climatic deterioration in the italian neogene succession” (pillans & naish, 2004, p. 2272). consistent with this recommendation, the basal part of the quaternary included the “calabrian”, a marine mediterranean stage defined by gignoux (1910) at s. maria di catanzaro (calabria, southern italy) and originally assigned by this author to the pliocene. in fact from the s. maria di catanzaro outcrop some “northern guest” molluscs such as arctica islandica were collected, and their presence indicated a climatic cooling, as pointed out by suess (1883-1909). several studies followed, in which numerous “northern guest” molluscs, foraminifers and ostracods were listed, and their appearance in the mediterranean area occurred in different pleistocene times (ruggieri, 1975, 1977, c. faranda & e. gliozzi 76 1980; ruggieri & sprovieri, 1977; malatesta & zarlenga, 1986). recently, through the stable isotope analyses of marine foraminifers, a first global cooling was detected in correspondence to the marine isotopic stage 100 (raymo et al., 1989), which falls about 60 ka after the middle/late pliocene boundary (piacenzian/gelasian gssp at monte s. nicola section (sicily) (rio et al., 1998). this discovery led the scientific community to discuss the possibility to move the pliocene/quaternary boundary down to the base of the gelasian. after around twenty years of heateded debates (cita & castradori, 1994 with references; vai, 1996 with references; suc et al., 1997 with references), in 2007 the inqua and ics stratigraphic commissions have jointly proposed a new stratigraphic assessment of pliocene and quaternary (ogg, 2007) (fig. 1), ratified by the ics commission during may 2009 (cita, 2009; mascarelli, 2009). in this new global stratigraphic scheme, the neogene/quaternary boundary corresponds to the base of the gelasian stage (2.588 ma), which represents the first stage of the quaternary system and also the first stage of the pleistocene series (gibbard et al., 2010). at present, the quaternary system includes the ratified or proposed standard stages gelasian, calabrian, ionian and tarantian (rio et al., 1998; cita et al., 2006). thus, in this paper, also the “cold” ostracods that entered the mediterranean during the gelasian are considered quaternary “northern guests”, since, as re-defined by ruggieri (1977), a species can be considered a true mediterranean “northern guest” if it is at present living outside the mediterranean, at more northern latitudes, and entered the mediterranean area during the “cold” global climatic oscillations. moreover, we consider stratigraphically useful to maintain the subdivision of the calabrian stage into the santernian, emilian and sicilian mediterranean regional substages, as defined by ruggieri et al. (1984) for the mediterranean. 2. the “northern guest” ostracods in the literature: a critical revision the first author who signalled the presence of “cold” ostracods in the mediterranean was ruggieri (1952a) who recovered a fragment of cytheropteron testudo sars 1870 from the lower pleistocene grey sands of imola (northern italy). since then, ruggieri and other authors have discussed the presence of “northern guest” ostracods in several papers (ruggieri, 1956, 1959, 1971, 1973, 1974, 1975, 1976, 1977, 1980; ruggieri et al., 1976, 1977; ruggieri & sprovieri, 1977; sissingh, 1976; faranda & gliozzi, 2008), giving a rather long list of species: actinocythereis dunelmensis (norman, 1865) argilloecia cylindrica sars, 1866 bythocythere dromedaria sars, 1866 bythocythere insignis sars, 1869 bythocythere zetlandica athersuch, horne & whittaker, 1983 cluthia keiji neale, 1975 cythere lutea müller, 1785 cytheropteron depressum (brady & norman, 1889) cytheropteron latissimum (norman, 1865) = cytherop teron sp. ex gr. c. latissimum (norman, 1865) cytheropteron punctatum brady, 1868 cytheropteron testudo sars, 1869 hemicythere villosa (sars, 1866) leptocythere macallana (brady & robertson, 1869) macrocypris minna (baird, 1850) muellerina problematica (seguenza, 1884) muellerina sp. nov. cf. m. abissicola (sars, 1866); nereina (?) sp. ind. paradoxoxtoma abbreviatum sars, 1866 paradoxostoma ensiforme brady, 1868 semicytherura angulata (brady, 1868) semicytherura producta (brady, 1868) thaerocythere (?) sp. xiphichilus tenuissimus (norman, 1869) the validity as “northern guests” of some of these species was discussed in several papers by ruggieri and by other authors. in particular: argilloecia cylindrica sars, 1866 some valves recovered by colalongo (1966) at le castella (calabria, southern italy) and referred to this northern species (colalongo, 1966; ruggieri, 1971) were subsequently revised by greco et al. (1974 p. 174) and assigned to the species zabythocypris antemacella (maddocks); the specimens from le castella and monasterace [calabria, southern italy of greco et al. (1974)] have been recently included by aiello, barra & bonaduce (1996a) within their new species anchistrocheles interrupta. bythocythere dromedaria sars, 1866 ruggieri (1956) assigned to this species some juvenile valves from the ?santernian of talignano (parma, northern italy) and from the emilian of sciacca (sicily, near bar maddalena); afterwards, ruggieri (1973) reported immature valves from pliocene deposits (no localities are specified), thus, this author cancelled the species from its “northern guest” list. we have seen the ruggieri ostracod collection (roc.) stored at the paleontological museum “g.g. gemmellaro” (palermo university), but, at present, it has not been possible to check the pliocene specimens since they are not in the collection, whereas the specimen from talignano (roc n° 1651) is not a bythocythere but a juvenile of pseudocythere (fig. 2). bythocythere insignis sars, 1869 according to ruggieri (1973), the valves recovered at ficarazzi (ruggieri, 1956) and acqua dei corsari (palermo, sicily) and referred to this species must be ascribed to monoceratina mediterranea sissingh, 1972. macrocypris minna (baird, 1850) ruggieri (1973) doubtfully included this species in its list of “northern guests” because it was recorded only by seguenza (1883-86) and never recovered again. indeed, seguenza dubitatively referred an anterior fragment of a valve of macrocyprididae to macrocypris minna? and he did not provide any illustration. muellerina sp. nov. cf. m. abyssicola (sars, 1866) ruggieri (1973) recognised a new species of muellerina, from the emilian of foce del verdura (sciacca, sicily) and compared it with the northern species m. abyssicola (sars 1866) suggesting that the italian specimens could be either a subspecies of this taxon or a new species phylogenetically linked to it. afterwards, ruggieri (1975) referred muellerina sp. nov. cf. m. abyssicola to the fossil species muellerina problematica a revision of the “northern guest” ostracoda (crustacea) occurrence in the quaternary of the … 77 fig. 1 magnetostratigraphy, chronostratigraphy, biostratigraphy and oxygen isotope stratigraphy of the quaternary system (isotopic scale from lourens et al., 2004). magnetostratigrafia, cronostratigrafia, biostratigrafia e stratigrafia isotopica del sistema quaternario (scala isotopica da lourens et al., 2004). (seguenza, 1884) but, because of its affinity with m. abyssicola, he continued to consider this species as a northern guest (ruggieri, 1977, 1980, 1991; ruggieri & sprovieri, 1977) even if it is a fossil species. yassini (1979) recovered muellerina latimarginata (speyer, 1863) (=m. problematica) in the piacenzian-gelasian of algeria and, more recently ciampo (1992) recovered m. problematica at s. todaro (calabria, southern italy) in the zanclean (mpl 3), thus, this species can no longer be considered a quaternary “northern guest”. leptocythere macallana (brady & robertson, 1869) ruggieri et al. (1976, 1977) included this spe c. faranda & e. gliozzi 78 fig. 2 pseudocythere sp.: broken left juvenile valve (transmitted light). this specimen is stored in the roc slide n° 1651 under the name bythocythere dromedaria talignano (parma). bar corresponds to 0.1 mm. pseudocythere sp.: valva sinistra giovanile rotta in luce trasmessa. l’esemplare è conservato nella collezione ostracodi ruggieri teca n° 1651 con il nome bythocythere dromedaria talignano (parma). la barra corrisponde a 0.1 mm. cies among the ostracod “northern guests” because it had been recovered from several calabrian deposits of calabria and sicily (ruggieri, 1952b; ruggieri et al., 1976, 1977). athersuch et al. (1989) consider the mediterranean species leptocythere levis (müller, 1894) a younger synonym of this species. ruggieri & d’arpa (1993) did not agree with this position. however, they recovered l. macallana in the piacenzian of altavilla (sicily), thus the species cannot be included any more among the quaternary “northern guests”. cytheropteron latissimum (norman, 1865) = cytheropteron sp. ex gr. c. latissimum (norman, 1865) ruggieri (1975) records the presence of c. latissimum in the sicilian deposit of acqua dei corsari (ficarazzi, sicily). in his paper of 1977, ruggieri changed the attribution of this species, considering it a species of cytheropteron different although similar to c. latissimum. unfortunately, ruggieri did not clearly characterise it taxonomically, nor did he illustrate it. the slide of this species within the ruggieri ostracod collection is empty. cluthia keiji neale, 1975 this species occurs for the first time in the mediterranean area in the calabrian (santernian). ruggieri (1977) and ruggieri & sprovieri (1977) included c. keiji within the “cold species” which migrated into the mediterranean in correspondence with the onset of the first pleistocene cooling episode. ruggieri (1977) himself stated that it could not be considered a true “northern guest” since the species adapted to the mediterranean climatic conditions and it is still living in this region. cluthia keiji was recovered by carbonnel & ballesio (1982) in the piacenzian deposits of the rhône valley, thus it cannot be considered as either a quaternary “northern guest” nor a “émigrés du nord attardés” sensu gignoux (1913) (ruggieri, 1977). thaerocythere (?) sp. (in ruggieri, 1977) = nereina (?) sp. indet. (in ruggieri, 1980) we agree with ruggieri (1977) that the specimens collected and illustrated from the sicilian of the valle del belice (sicily) cannot be referred with certainty to the genus thaerocythere hazel, 1967. the shape of the posterior border and the ornamentation of the valve illustrated by ruggieri (1977) point to the genus grinioneis liebau, 1975. in any case, the sicilian valves are completely different from the recent arctic species thaerocythere crenulata (sars, 1866). the same specimens cannot be referred to the arctic genus nereina mandelstam, 1957 because the hinge is different, smooth in nereina but with a crenulated bar in the valle del belice specimens. thus, the doubtful attribution of these valves as a possible “northern guest” cannot be accepted. following our revision, the specimen hosted as thaerocythere (?), valle del belice, in the ruggieri ostracod collection at palermo (n° 2766) is referable to muellerina problematica, and is not the specimen illustrated by ruggieri (1977). probably, a dislocation of the stored valve occurred and the original specimen identified as thaerocythere(?) must be considered lost. semicytherura producta (brady, 1868) ruggieri (1976) reports this species from the calabrian of chirco, ciantrato (marsala, sicily) and ficarazzi (sicily). during the revision of the ruggieri’s collection these specimens have not been found. in the collection there is one never published broken valve from via del fante (palermo, sicily), (g.o.c. n° 2593c), from which it is impossible to confirm the identification. thus, for the moment, the presence of s. producta in the mediterranean during quaternary is dubitative. in conclusion, only the following 11 species, reported with the updated nomenclature, can be considered true “northern guest” ostracods: acanthocythereis dunelmensis (norman, 1865) bythocythere zetlandica athersuch, horne & whittaker, 1983 cythere lutea müller, 1785 cytheropteron depressum (brady & norman, 1889) cytheropteron punctatum brady, 1868 cytheropteron testudo sars, 1869 hemicythere villosa (sars, 1866) paradoxostoma abbreviatum sars, 1866 paradoxostoma ensiforme brady, 1868 paradoxostoma tenuissimum (norman, 1869) semicytherura angulata (brady, 1868) to this list one more species should be added, not noted by ruggieri as a quaternary “northern guest” since he recovered it from the gelasian of castellarquato (piacenza) (ruggieri, 1976): bythocythere turgida (sars, 1866). 3. stratigraphic and geographic distribution of the quaternary “northern guest” ostracods in the mediterranean area acanthocythereis dunelmensis (norman, 1865) (fig. 3) 1865 cythereis dunelmensis sp. n. norman, pp. 22, pl. 7, figs. 1-4. 1967 acanthocythereis (?) dunelmensis (norman) hazel, p. 34. 1969 trachyleberis dunelmensis (norman) nov. comb. yassini, p. 49. 1977 actinocythereis dunelmensis (norman) nov. comb. ruggieri, p. 83, fig. 1. 1989 acanthocythereis dunelmensis (norman) nov. comb. athersuch et al., pp.132-134, fig. 52; pl. 3, fig. 10. a revision of the “northern guest” ostracoda (crustacea) occurrence in the quaternary of the … 79 fig. 3 acanthocythereis dunelmensis: (a) right valve under transmitted light, (b) left valve under sem from catarinicchia (belice valley, sicily), sicilian age; (roc slide n° 2760); (c) present geographical distribution (dark grey line) and early pleistocene distribution in the mediterranean area (black dot). bar corresponds to 0.1 mm. acanthocythereis dunelmensis: (a) valva destra in luce trasmessa, (b) valva sinistra in scansione elettronica, provenienti dalla località catarinicchia locality (valle del belice, sicilia), età siciliano; (collezione ostracodi ruggieri teca n° 2760); (c) distribuzione geografica attuale (linea grigio scura) e distribuzione nel mediterraneo nel pleistocene inferiore (punti neri). la barra corrisponde a 0.1 mm. recent distribution: s. baltic sea, öres, bohuslän, n. norway, iceland and arctic seas, shetlands, ne british isles, east greenland (athersuch et al., 1989; malz, 1989; hansson, 1998; frenzel et al., 2010); hornsund (south spitsbergen) (mackiewicz, 2006); laptev sea (n. russia) (stepanova et al., 2003, 2007, 2010). ostracod bioprovince: celtic arctic (fig. 4) ecology: it inhabits the marine inner outer shelf environment (50-100 m), in polyhaline-euhaline conditions and water temperatures that range from -2 to 13 (19)°c (wilkinson, 2005; stepanova et al., 2007, 2010; frenzel et al., 2010). fossil distribution in the mediterranean: calabrian (sicilian): belice, (sicily) (ruggieri, 1977, 1980). bythocythere turgida sars, 1866 (fig. 5) 1866 bythocythere turgida sp. nov. sars, p. 84, pl. 107, figs. 1-12. bythocythere turgida is a problematic species. the original drawings by sars (1866, 1928) are the only available illustrations of this species. athersuch et al. (1983), revising the bythocythere species from the british coasts, split this species into three different taxa: b. turgida, at present distributed only on the norway coasts, b. robinsoni athersuch, horne & whittaker, 1983, and b. bradleyi athersuch, horne & whittaker, 1983, living only in the british waters. unfortunately these authors did not illustrate b. turgida s.s. malz & jellinek (1984) agree with athersuch et al. (1983) and discuss the possible attribution of their specimen to b. turgida. in the present paper we consider the specimen illustrated by malz & jellinek (1984) from the calabrian (emilian) of peloponnesus (greece) as males of fig. 4 eastern atlantic ostracod bioprovinces (redrawn from frenzel et al., 2010). bioprovince ad ostracodi dell’atlantico orientale (ridisegnata da frenzel et al., 2010). c. faranda & e. gliozzi 80 fig. 5 bythocythere turgida: (a) left valve from breman, 1976; (b) present geographical distribution (dark grey line), early pleistocene distribution in the mediterranean area (black dot), last glacial maximun distribution in the mediterranean (white circle). bar corresponds to 0.1 mm. bythocythere turgida: (a) valva sinistra da breman, 1976; (b) distribuzione geografica attuale (linea grigio scura), distribuzione nel mediterraneo durante il pleistocene inferiore (punti neri) e durante il pleniglaciale (cerchi bianchi). la barra corrisponde a 0.1 mm. b. puncticulata ruggieri, 1976. even the specimen from the zanclean of bou ismail (algeria) illustrated as bythocythere turgida by yassini (1979) could be a female of the same species. the bythocythere turgida specimen from partanna (sicily, early calabrian) recovered in the roc slide n° 2526 is not referable to this species but to a juvenile male of b. puncticulata ruggieri, 1976 (fig. 6). the inclusion of b. turgida within the list of the living mediterranean species (aiello et al., 1995) is due to the recovery of some loose valves from the adriatic and tyrrhenian seas (bonaduce et al., 1976, 1983; breman, 1976; arbulla et al., 2001, 2004). according to ruggieri (1976) the specimens collected by breman in the adriatic sea must be considered as subfossil and referable to the last pleniglacial maximum migration. we suppose that also the bonaduce et al. (1976) specimens from the same sea were subfossil. arbulla et al. (2001, 2004) recover the few juvenile valves of b. turgida from la maddalena (sardinia) in a sample at 2-7 m of depth. such shallow depth lead us to infer that these specimens too are subfossil. in conclusion, we consider bythocythere turgida as a true “northern guest”. recent distribution: koster channel, oslofjord, s and w norway, spitzbergen (athersuch et al., 1983; malz & jellinek, 1994; hansson, 1998). ostracod bioprovince: norwegian arctic (fig. 4) ecology: according to elofson (1941) it is a polyhalineeuhaline species that inhabits shallow to rather deep waters (20-140 m) fossil distribution in the mediterranean: gelasian: castellarquato (piacenza, northern italy) (ruggieri, 1976) calabrian (emilian): cinisi (palermo, sicily) (ruggieri, 1976). tarantian (last pleniglacial): adriatic sea (bonaduce et al., 1976; breman, 1976) tyrrenian sea (maddalena island) (arbulla et al., 2001; 2004) western mediterranean basin (near algerian coast) (bonaduce et al., 1983) bythocythere zetlandica athersuch, horne & whittaker, 1983 (fig. 7) 1983 bythocythere zetlandica sp. nov. athersuch, horne & whittaker, p. 73, figs. 5c, 41-n; pl. 2, figs. 5-8. in the roc slide n° 856 a broken juvenile specimen is stored labelled bythocythere cf. b. zetlandica collected from the gelasian capocolle clays (forlì, northern italy) (fig. 8). we have revised it and we prefer to leave it in open nomenclature since it does not seem a juvenile of b. zetlandica. recent distribution: shetlands, n. britain (athersuch et al., 1989; hansson, 1998). ostracod bioprovince: celtic (britannic) (fig. 4) fig. 6 bythocythere puncticulata: left juvenile male valve. this specimen is stored in the roc slide n° 2526, partanna (sicily, early calabrian), labelled as bythocythere cf. b. turgida. bar corresponds to 0.1 mm. bythocythere puncticulata: valva sinistra maschile giovanile. l’esemplare è conservato nella collezione ostracodi ruggieri teca n° 2526, partanna (sicilia, calabriano inferiore) con il nome bythocythere cf. b. turgida. la barra corrisponde a 0.1 mm. a revision of the “northern guest” ostracoda (crustacea) occurrence in the quaternary of the … 81 fig. 7 bythocythere zetlandica: (a) left valve from monte mario (roma, latium), santernian age; (gliozzi’s ostracod collection (goc) slide n° m83/4/15). (b) present geographical distribution (dark grey line) and early pleistocene distribution in the mediterranean area (black dot). bar corresponds to 0.1 mm. bythocythere zetlandica: (a) valva sinistra da monte mario (roma, lazio), età santerniano; (collezione ostracodi gliozzi teca n° m83/4/15). (b) distribuzione geografica attuale (linea grigio scura) e distribuzione nel mediterraneo durante il pleistocene inferiore (punti neri) la barra corrisponde a 0.1 mm. ecology: inner circalittoral waters around british coasts (athersuch et al., 1989) fossil distribution in the mediterranean: calabrian (santernian): monte mario (rome, central italy), from the 2° a. islandica level (faranda & gliozzi, 2008). cythere lutea o.f. müller, 1785 (fig. 9) 1785 cythere lutea sp. n. o.f. müller, p. 65, pl. 7, figs. 3-4. 1818 cytherina lutea (o.f. müller) nov. comb. lamarck, p. 125. 1941 cythere lutea o.f. müller sylvester-bradley, p. 27, figs. 15-18 (with full synonimy) recent distribution: kieler bucht, öres, bohuslän, bergen, n. norway, iceland and arctic seas, shetlands, sw british isles, scilly isles, w france (hansson, 1998; freiwald et al., 1998; mackiewicz, 2006); kent coast (isle of thanet) (bruce, 2002); north yorkshire (hull, 1998); from s. norway to n france (athersuch et al., 1989); subfrigid to mild temperate waters of the atlantic and pacific ocean (hanai, 1977). a subspecies (cythere lutea omotenipponica hanai, 1959) reaches the warm temperate climatic zone along the pacific coast of japan (hanai, 1977). ostracod bioprovince: celtic arctic (fig. 4) ecology: the species inhabits shallow waters (30-50 m) with sandy bottom or populated by coralline algae. it withstands mesoto euhaline salinities and a wide range of temperature (-2 to 22°c) (freiwald et al., 1998; frenzel et al., 2010). fossil distribution in the mediterranean: calabrian (sicilian): lo sperone (palermo, sicily) (ruggieri, 1971, 1973). cytheropteron depressum brady & norman, 1889 (fig. 10) 1889 cytheropteron depressum sp. n. brady & norman, p. 447, pl. 34, figs. 39-42. recent distribution: sw british isles, (athersuch et al., 1989; hansson, 1998); scilly isles (neale, 1970). ostracod bioprovince: celtic (britannic) (fig. 4) ecology: inner circalittoral marine environment (athersuch et al., 1989) fossil distribution in the mediterranean: calabrian (santernian): monte mario (rome, central italy), from the 2° a. islandica level (faranda & gliozzi, 2008). fig. 8. bythocythere sp.: left juvenile broken valve. this specimen is stored in the roc slide n° 856 under the name bythocythere cf. b. zetlandica gelasian capocolle clays (forlì, northern italy). bar corresponds to 0.1 mm. bythocythere sp.: valva sinistra giovanile rota. questo esemplare è conservato nella collezione ostracodi ruggieri teca n° 856 col nome bythocythere cf. b. zetlandica gelasiano, argille di capocolle (forlì, italia settentrionale). la barra corrisponde a 0.1 mm. c. faranda & e. gliozzi 82 cytheropteron punctatum brady, 1868 (fig. 11) 1868 cytheropteron punctatum nov. sp. brady, p. 449, pl. 34, figs. 45-48. recent distribution: korshavn, s. norway, bergen, british isles, bay of biscay (hansson, 1998). ostracod bioprovince: celtic norwegian (fig. 4) ecology: penney (1993) collected this species from the silty bottom of the norway channel at a depth comprised between 190 and 270 m, bottom temperature between 6.5-7°c, and euhaline salinity. fossil distribution in the mediterranean: calabrian: tavoliere delle puglie (southern italy) (ruggieri, 1959). crete (sissingh, 1972). calabrian (santernian): valle del tronto (marche, central italy) (pucci, 1956; ruggieri, 1973). vrica (calabria, southern italy) about 10 m above the first occurrence of cytheropteron testudo (colalongo & pasini, 1980; pasini & colalongo, 1994). calabrian (emilian): vrica (calabria, southern italy) (colalongo & pasini, 1980; pasini & colalongo, 1994). cala bianca (marina di camerota, campania, southern italy) (ciampo, 1976). calabrian (sicilian): ficarazzi (palermo, sicily) (ruggieri, 1956, 1973). s. maria di catanzaro (calabria, southern italy) (sissingh, 1973a). monasterace (calabria, southern italy) (greco et al., 1974). cytheropteron testudo sars, 1869 (fig. 12) 1869 cytheropteron testudo nov. sp. sars, p. 173, pl105, fig. 1. recent distribution: lofoten, spitsbergen, koster channell, hardangenfjord (hansson, 1998); laptev sea (n. russia) (stepanova et al., 2003); scoresby sound, w greenland (whatley et al., 1996, 1998; mackiewicz, 2006); murray island (e greenland), newfoundland (benson et al., 1984), norwegian coast down to the skagerrak (ruggieri, 1971, 1973, 1977). the report of this species in the bay of biscay (yassini, 1969) concerns only loose valves. the possible distribution of c. testudo in the southern hemisphere is discussed by several authors (swanson & ayress, 1999; dixon, 2006; jellinek et al., 2006) but this problem is beyond the topic of the present paper. ostracod bioprovince: norwegian arctic (fig. 4) ecology: it is a rather deep species. it as been reported from norway at depths comprised between 80 and 240 m (freiwald et al., 1998 ) and down to 300 m (penney, 1993) at bottom temperatures comprised between 7.0 and 7.4°c. elofson (1941) reports c. testudo from skagerrak at 270 m of depth and from spitzbergen at 150 m at bottom temperatures from -2° to 10°c. fossil distribution in the mediterranean: gelasian: m. s. nicola (sicily) at 68 m (sample 35) (aiello et al., 1996b, 2000; bonaduce & sprovieri, 1984). camerano (forlì, northern italy) (ruggieri, 1977, 1978, 1996). castrocaro (forlì, northern italy) (ruggieri, 1977, 1978, 1996). “calabrian”: kos (greece, aegean sea) (mostafawi, 1981,1986). rhodes (greece, aegean sea) (mostafawi, 1989). zakinthos (greece, ionian sea) (tsapralis, 1981). calabrian (santernian): vrica (calabria, southern italy), about 10 m above the sapropel e (colalongo & pasini, 1980; pasini & colalongo, 1994). ribera (southern sicily) (ruggieri, 1977). cosenza (calabria, southern italy) (ruggieri, 1952b). calabrian (emilian): vrica (calabria, southern italy) (colalongo & pasini, 1980; pasini & colalongo, 1994). imola (northern italy) (ruggieri, 1952a, 1975). mar piccolo (taranto, southern italy) (ciampo, 1971). porto recanati (ancona, central italy) (ruggieri, 1971). località “il carmine” (crotone, calabria, southern italy) (ruggieri, 1952a). località in destra del verdura (sciacca, sicily) (ruggieri, 1973). calabrian (sicilian): le castella (calabria, southern italy) (colalongo, 1966). s. maria di catanzaro (calabria, southern italy) (sissingh, 1973a). ficarazzi (palermo, sicily) (sissingh, 1973b). mar piccolo (taranto, southern italy) (ciampo, 1971). porto recanati (ancona, central italy) (ruggieri, 1971). località “il carmine” (crotone, calabria, southern italy) (ruggieri, 1952a). località in destra del verdura (sciacca, sicily) (ruggieri, 1973). pizzo longo (crotone, calabria, southern italy) (this paper, together with g. truncatulinoides excelsa). tarantian (last pleniglacial): gulf of taranto (moncharmont-zei et al., 1985) adriatic sea (breman, 1976) hemicythere villosa (sars, 1866) (fig. 13) 1866 cythereis villosa nov. sp. sars, p. 42. 1868 cythere villosa (sars) brady, p. 411, pl. 29, figs. 28-32. 1925 hemicythere villosa (sars) sars, p. 182, pl. 84, figs. 1-13. 1941 cythereis (eucythereis) villosa sars elofson, pp. 287288. recent distribution: kieler bucht, öres, bohuslän, north sea, n. norway, iceland, bear island (swalbard), british isles, scilly isles, bay of biscay (hansson, 1998); kent coast (isle of thanet) (bruce, 2002); davis strait (baffin bay) (elofson, 1941), atlantic north america (virginia coast) (hulings, 1966); britain and nw european coasts (athersuch et al., 1989). ostracod bioprovince: celtic arctic (fig. 4) a revision of the “northern guest” ostracoda (crustacea) occurrence in the quaternary of the … 83 fig. 9 cythere lutea: (a) right valve (transmitted light), (b) right valve under sem from sperone locality (palermo), calabrian (sicilian) (roc slide n° 1623); (c) present geographical distribution (dark grey line) and early pleistocene distribution in the mediterranean area (black dot). bar corresponds to 0.1 mm. cythere lutea: (a) valva destra in luce trasmessa, (b) valva destra in scansione elettronica dalla località sperone (palermo, sicilia), calabriano (siciliano) (collezione ostracodi ruggieri teca n° 1623); (c) distribuzione geografica attuale (linea grigio scura) e distribuzione nel mediterraneo durante il pleistocene inferiore (punti neri). la barra corrisponde a 0.1 mm. fig. 10 cytheropteron depressum: (a) left valve from monte mario (roma, latium), santernian age; (goc slide n° m114/1/5). (b) present geographical distribution (dark grey line) and early pleistocene distribution in the mediterranean area (black dot). bar corresponds to 0.1 mm. cytheropteron depressum: (a) valva sinistra da monte mario (roma, lazio), età santerniano; (collezione ostracodi gliozzi teca n° m114/1/5). (b) distribuzione geografica attuale (linea grigio scura) e distribuzione nel mediterraneo durante il pleistocene inferiore (punti neri). la barra corrisponde a 0.1 mm. c. faranda & e. gliozzi 84 fig. 11 cytheropteron punctatum: (a) right valve from monasterace (calabria), sicilian age; (roc slide n° 2313). (b) present geographical distribution (dark grey line) and early pleistocene distribution in the mediterranean area (black dot). bar corresponds to 0.1 mm. cytheropteron punctatum: (a) valva destra dalla località monasterace (calabria, italia meridionale), età siciliano; (collezione ostracodi ruggieri teca n° 2313). (b) distribuzione stratigrafica attuale (linea grigio scura) e distribuzione nel mediterraneo durante il pleistocene inferiore (punti neri). la barra corrisponde a 0.1 mm. fig. 12 cytheropteron testudo: (a) right valve (transmitted light), (b) right valve under sem from “il carmine” locality (crotone, calabria), emilian age; (roc slide n° 924). (c) present geographical distribution (dark grey line), early pleistocene distribution in the mediterranean area (black dot), last glacial maximun distribution in the mediterranean (white circle). bar corresponds to 0.1 mm. cytheropteron testudo: (a) valva destra in luce trasmessa, (b) valva destra in scansione elettronica dalla località “il carmine” (crotone, calabria), età emiliano; (collezione ostracodi ruggieri n° 924). (c) distribuzione geografica attuale (linea grigio scura) e distribuzione nel mediterraneo durante il pleistocene inferiore (punti neri) ed il pleniglaciale (cerchi bianchi). la barra corrisponde a 0.1 mm. a revision of the “northern guest” ostracoda (crustacea) occurrence in the quaternary of the … 85 fig. 13 hemicythere villosa: (a) right valve in transmitted light, (b) left valve under sem from sperone (palermo) (roc slide n° 1640); (c) present geographical distribution (dark grey line) and early pleistocene distribution in the mediterranean area (black dot). bar corresponds to 0.1 mm. hemicythere villosa: (a) valva destra in luce trasmessa, (b) valva sinistra in scansione elettronica dalla località sperone (palermo, sicilia) (collezione ostracodi ruggieri teca n° 1640); (c) distribuzione stratigrafica attuale (linea grigio scura) e distribuzione nel mediterraneo durante il pleistocene inferiore (punti neri). la barra corrisponde a 0.1 mm. ecology: it inhabits marine very shallow to shallow waters with vegetated sandy bottoms and water temperatures that range from 0 to 22°c in mesohaline-euahaline conditions (elofson, 1941; athersuch et al., 1989; frenzel et al., 2010). fossil distribution in the mediterranean: calabrian (sicilian): lo sperone (palermo, sicily) (ruggieri, 1971; 1973, 1980; sissingh, 1976). paradoxostoma abbreviatum sars, 1866 (fig. 14) 1866 paradoxostoma abbreviatum sp. nov. sars, p. 94 recent distribution: s. baltic, öres, bohuslän, holland, bergen, shetlands, british isles, n france, ?bay of biscay (hansson, 1998); british isles, norway, baltic, helgoland and n france (athersuch et al., 1989); north yorkshire (hull, 1998). ostracod bioprovince: celtic (?gasconyan) norwegian (fig. 4) ecology: p. abbreviatum is typical of mesohaline to euhaline very shallow to shallow waters (0.2 to 20 m)with vegetated and highly oxygenated sandy bottoms, and water temperatures that range from 2 to 5°c (elofson, 1941; athersuch et al., 1989; frenzel et al., 2010). fossil distribution in the mediterranean: calabrian (santernian): monte mario (rome, central italy), from the 2° a. islandica level (faranda & gliozzi, 2008). paradoxostoma ensiforme brady, 1868 (fig. 15) 1868 paradoxostoma ensiforme sp. nov. brady, p. 460, pl. 35, figs. 8-11. recent distribution: bohuslän, holland,?s and w norway, shetlands, sw british isles, n france, ?bay of biscay (athersuch et al., 1989; hansson, 1998); north yorkshire (hull, 1998). ostracod bioprovince: celtic (?gasconyan) norwegian (fig. 4) ecology: the species inhabits mesohaline to euhaline very shallow to shallow waters (5 to 18 m on vegetated bottom and down to 50 m on detritic sands), and a wide range of water temperatures (elofson, 1941; athersuch et al., 1989; frenzel et al., 2010). fossil distribution in the mediterranean: calabrian (santernian): monte mario (rome, central italy), from the 2° a. islandica level (faranda & gliozzi, 2008). c. faranda & e. gliozzi 86 fig. 14 paradoxostoma abbreviatum: (a) right valve from monte mario (roma, latium), santernian age; (gocollection slide n° t30/1). (b) present geographical distribution (dark grey line) and early pleistocene distribution in the mediterranean area (black dot). bar corresponds to 0.1 mm. paradoxostoma abbreviatum: (a) valva destra proveniente da monte mario (roma, lazio), età santerniano; (collezione ostracodi gliozzi teca n° t30/1). (b) distribuzione stratigrafica atuale (linea grigio scura) e distribuzione nel mediterraneo durante il pleistocene inferiore (punti neri). la barra corrisponde a 0.1 mm. fig. 15 paradoxostoma ensiforme: (a) left valve from monte mario (roma, latium), santernian age; (goc slide n°t30/2). (b) present geographical distribution (dark grey line) and early pleistocene distribution in the mediterranean area (black dot). bar corresponds to 0.1 mm. paradoxostoma ensiforme: (a) valva sinistra proveniente da monte mario (roma, lazio), età santerniano; (collezione ostracodi gliozzi teca n°t30/2). (b) distribuzione geografica attuale (linea grigio scura) e distribuzione nel mediterraneo durante il pleistocene inferiore (punti neri). la barra corrisponde a 0.1 mm. paradoxostoma tenuissimum (norman, 1869) (fig. 16) 1869 bythocythere tenuissimum sp. nov. norman, p. 294. 1870 xiphichilus tenuissimum (norman) brady, p. 369, pl. 12, figs. 6-9. 1889 machaerina tenuissima (norman) brady & norman, p. 238, pl. 21, figs. 13-14. 1985 paradoxostoma tenuissimum (norman) horne & whittaker, p. 182, figs. 30a-e, 31a-f, 32a-e, 44d-e, 45d-e recent distribution: british isles from scotland and shetlands (hansson, 1998; athersuch et al., 1989). ostracod bioprovince: celtic (britannic) (fig. 4) ecology: p. tenuissimum is considered one of the most deep species of the genus, inhabiting waters down to 50-100 m (athersuch et al., 1989). fossil distribution in the mediterranean: calabrian (emilian): cosenza (calabria, southern italy), together with hyalinea balthica (ruggieri, 1975). calabrian (sicilian): casa schifo (between gela and vittoria, sicily) (ruggieri, 1975). tarantian (last pleniglacial): adriatic sea (bonaduce et al., 1976; breman, 1976) semicytherura angulata (brady, 1868) (fig. 17) 1868 cytherura angulata sp. nov. brady, p. 440, pl. 32, figs. 22-25. 1957 semicytherura angulata (brady) wagner, p. 84, pl. 39. recent distribution: kieler bucht, belt sea, bohüslan, a revision of the “northern guest” ostracoda (crustacea) occurrence in the quaternary of the … 87 hölland, hardnger fjord, iceland, shetlands and sw british isles (hansson, 1998); british isles and northern europe (athersuch et al., 1989); ?bay of biscay (yassini, 1969). ostracod bioprovince: celtic (britannic) norwegian (fig. 4) ecology: the species inhabits mesohaline to euhaline very shallow to shallow waters (5 to 10 m) in ma rine and estuarine conditions, with vegetated bottom, and a wide range of water temperatures (elofson, 1941; athersuch et al., 1989). fossil distribution in the mediterranean: calabrian (emilian): apennine piedmont near forlì (northern italy) (ruggieri et al., 1976). calabrian (emilian or sicilian): chirco, digerbato and ciantrato (marsala, sicily) (ruggieri, et al. 1977). fig. 16 paradoxostoma tenuissimum: (a) broken left valve from cosenza (calabria), emilian age; (roc slide n° 745); (b) present geographical distribution (dark grey line), early pleistocene distribution in the mediterranean area (black dot), last glacial maximun distribution in the mediterranean (white circle). bar corresponds to 0.1 mm. paradoxostoma tenuissimum: (a) valva sinistra rotta proveniente da cosenza (calabria, italia meridionale), età emiliana; (collezione ostracodi ruggieri teca n° 745); (b) distribuzione geografica attuale (linea grigio scura) e distribuzione nel mediterraneo durante il pleistocene inferiore (punti neri) e il pleniglaciale (cerchi bianchi). la barra corrisponde a 0.1 mm. fig. 17 semicytherura angulata: (a) right valve in transmitted light, (b) right valve under sem from digerbato well (marsala), emilian or sicilian age; (roc slide n° 2622); (c) present geographical distribution (dark grey line) and early pleistocene distribution in the mediterranean area (black dot). bar corresponds to 0.1 mm. semicytherura angulata: (a) valva destra in luce trasmessa, (b) valva destra in scansione elettronica provenienti dal pozzo digerbato (marsala, sicilia), età emiliana o siciliana; (collezione ostracodi ruggieri teca n° 2622); (c) distribuzione geografica attuale (linea grigio scura) e distribuzione nel mediterraneo durante il pleistocene inferiore (punti neri). la barra corrisponde a 0.1 mm. c. faranda & e. gliozzi 88 4. discussion and conclusion the critical revision of the “cold” ostracods recovered in the mediterranean quaternary proposed in this paper reduces the number of the true “northern guest” from the 22 species reported in literature only to 12 confirmed taxa. they are generally rare within their assemblages, often represented only by a single specimen from a single locality. only c. testudo and c. punctatum have been reported with a wide mediterranean geographical distribution in italy and in the aegean sea. almost all the “northern guest” ostracods have their present southernmost distribution in the celtic bioprovince except b. turgida and c. testudo that are more northern species, presently widespread only from the norwegian to the arctic bioprovince. data on the ecological requirements of the listed “cold” ostracods lead to divide them into three groups on the basis of the water depth: the shallow (infralittoral) species (c. lutea, h. villosa, p. abbreviatum, p. ensiforme, and s. angulata); the circalittoral species (a. dunelmensis, b. turgida, b. zetlandica, c. depressum, and p. tenuissimum); the circalittoralupper epibatial species (c. punctatum and c. testudo). temperature ranges are known only for few species, but two groups can be recognized: eurythermal species, such as c. lutea and h. villosa, and cold stenothermal species as c. punctatum, c. testudo and p. abbreviatum. the temperature ranges of this latter group (-2 to 10°c) does not fit neither the monthly mean temperatures of the mediterranean superficial waters for january and july 2011 (fig. 18) nor the mean annual temperature of the mediterranean superficial waters as inferred by kuhlemann et al., 2008 for the last glacial maximum (fig. 19). their presence in the quaternary mediterranean deposits can be explained by their settlements in deeper habitats, in search of lower temperatures: c. punctatum and c. testudo have been recovered in the mediterranean in associations with lower epibathial species, whereas the epiphytal inner infralittoral p. abbreviatum moved towards the outer infralittoral bottoms. on the contrary, in the quaternary, the eurythermal species occurred in the mediterranean in the same range of depths as present. the conclusion reached with this revision leads to a comparison with the “northern guest” molluscs (malatesta & zarlenga, 1986). quaternary “northern guest” ostracod species are fewer than mollusc species (twelve against fifty-three) but in both cases they are generally rare within their assemblages. in fact also among molluscs, very few species can be considered common (> ten localities: pseudamussium septemradiatum (müller, 1776), arctica islandica (linnaeus, a revision of the “northern guest” ostracoda (crustacea) occurrence in the quaternary of the … 89 fig. 20 stratigraphic distribution of the “northern guest” ostracods in the mediterranean area. distribuzione stratigrafica degli ostracodi “ospiti nordici” nel mediterraneo. 1767), lunatia montagui (forbes, 1838), neptunea contraria (linnaeus, 1771), buccinum undatum linnaeus, 1767 and buccinum humpreysianum bennet, 1825). like the “northern guest” molluscs, also ostracods entered the mediterranean at different times (fig. 20), being more abundant in the sicilian substage. “northern guest” molluscs were reported also from the last glacial maximum deposits of cap créus (mars, 1958), confirming that the migration of “cold” species into the mediterranean followed the cyclic cold climate oscillations. “northern guest” ostracods have been mainly recorded in the lower quaternary sediments, but one study on the last glacial maximum ostracods (moncharmont-zei et al., 1985) reports the presence of cytheropteron testudo in deposits of the ionian sea. additionally, in some papers dealing with modern mediterranean ostracod faunas some other “cold” species are listed, recovered as loose valves. for example, breman (1976) and bonaduce et al. (1976) reported loose valves of cytheropteron testudo, bythocythere turgida and paradoxostoma tenuissimum, whose presence in the adriatic sea could be better linked to reworked remains of the last glacial maximum. in conclusion, this revision of the “northern guest” ostracods suggests that they could be a valuable tool for interpreting cold climatic events in a sedimentary succession, but further studies are needed to improve the knowledge of the quaternary “cold” ostracod contingent in the mediterranean. acknowledgments we are deeply indebted with dr. carolina d’arpa, curator of the museum “g.g. gemmellaro” of palermo, who kindly made available to us the ruggieri’s ostracod collection for the revision of true or supposed ostracod “northern guests”. we whish to thank our referees ilaria mazzini and diana barra who helped us to improve this paper. references aiello g., barra d. & bonaduce g. (1995) crustacea ostracoda. checklist delle specie della fauna d’italia 27, pp. 1-19, calderini ed., bologna. aiello g., barra d. & bonaduce g. (1996a) anchistrocheles interrupta a new deep-water marine ostracod species (pussellinae, ostracoda) from the plio-pleistiocene of the mediterranean basin boll. soc. paleont. ital., 34 (3), pp. 271-274. aiello g., barra d. & bonaduce g. (1996b) the genus cytheropteron sars 1866 (crustacea: ostracoda) in the pliocene-early pleistocene of the m. san nicola section (gela, sicily). micropaleontol., 42 (2), pp. 167-178. aiello g., barra d. & bonaduce g. (2000) systematics and biostratigraphy of the ostracoda of the plio-pleistocene monte s. nicola section (gela, sicily). boll. soc. paleont. ital., 39 (1), pp. 83-112. arbulla d., pugliese n. & russo a. (2001) ostracodi del golfo saline (sardegna nord-orientale). studi trentini di scienze naturali-acta geologica, 77, pp. 25-35. arbulla d., pugliese n. & russo a. (2004) ostracods from the national park of la maddalena archipelago (sardinia, italy). boll. soc. paleont. ital., 43 (1-2) pp. 91-99. athersuch j., horne d.j. & whittaker j.e. (1983) some species of the ostracod genus bythocythere sars from british waters. j. micropaleontol., 2, pp. 71-81. athersuch j., horne d.j. & whittaker j.e. (1989) marine and brackish water ostracods (superfamilies cypridacea and cytheracea). in: kermack d.m. & barnes r.s.k.(eds) synopsis of the british fauna (n.s.), 43 pp. 1-343, london. benson r.h., delgrosso r.m. & steineck p.l. (1984) ostracode distribution and biofacies, newfoundland continental slope and rise. micropaleontol., 29 (4), pp. 430-453. bonaduce g. & sprovieri r. (1984) the appearance of cytheropteron testudo sars (crustacea: ostrac. faranda & e. gliozzi 90 coda) is a pliocene event. evidences from a sicilian sequence (italy). boll. soc. paleont. ital., 23 (1), pp. 131-136. bonaduce g., ciampo g. & masoli m. (1976) distribution of ostracoda in the adriatic sea. pubbl. staz. zool. napoli, 40 (suppl.), pp. 1-304.bonaduce g., ciliberto b., masoli m., minichelli g. & pugliese n. (1983) the deep-water benthic ostracodes of the mediterranean. in: maddocks r.f. (ed.), applications of ostracoda, university of houston, geosciences department, texas, pp. 459-471. brady g.s. (1868) a monograph on the recent british ostracoda. trans. linn. soc. lond., 26, pp. 353-495. brady g.s. (1870) notes on entomostraca taken chiefly in the northumberland and durham district. nat. hist. trans. northumb, 3, pp. 361-373. brady g.s. & norman a.m. (1889) a monograph of the marine and freshwater ostracoda of the north atlantic and northwestern europe. section 1, podocopa. scient. trans. r. dubl. soc., ser. 2, 4, pp. 63-270. breman e. (1976) the distribution of ostracodes in the bottom sediments of the adriatic sea. academische proefschriften vrije universität, amsterdam, pp. 1-165. bruce a. (2002) the importance of ostracoda and their relsationship with the marine near shore environment of thanet. proceedings of the 1st north east kent coastal research workshop, sandwich bay bird observatory 22 october, 2002, report 570, pp. 37-43. carbonnel g. & ballesio r. (1982) les ostracodes pliocenes du sud-est de la france. doc. lab. géol. lyon, 85, pp. 1-113. ciampo g. (1971) gli ostracodi delle argille pleistoceniche del mar piccolo (taranto). boll. soc. nat. napoli, 80 (37) pp. 49-88. ciampo g. (1976) ostracodi pleistocenici di cala bianca (marina di camerata, salerno). boll. soc. paleont. ital., 15 (1), pp. 3-23. ciampo g. (1992) ostracofaune plioceniche della calabria ionica. boll. soc. paleont. ital., 31 (2), pp. 223239. cita, m.b. (2009) a proposito del quaternario. geoitalia, 28 (settembre 2009), pp. 44-52. cita m.b. & castradori d. (1994) workshop on marine sections from the gulf of taranto (southern italy) usable as potential stratotypes for gssp of the lower, middle and upper pleistocene. il quaternario, 7, pp. 677-692. cita m.b., capraro l., ciaranfi n., di stefano e., marino m., rio d., sprovieri r. & vai g.b. (2006) calabrian and ionian: a proposal for the definition of mediterranean stages for the lower and middle pleistocene. episodes, 29 (2), pp. 107-114. colalongo m.l. (1966) gli ostracodi della serie di le castella (calabria). giorn. geol., 2, 33 (1), pp. 183129. colalongo m.l. & pasini g. (1980) l’ostracofauna plio-pleistocenica della sezione di vrica in calabria (con considerazioni sul limite neogene/quaternario). boll. soc. paleont. ital., 19 (1), pp. 44-126. dixon p. j. (2006) environmental implications of recent ostracod distributions in the larsen ice shelf region, earstern antartic peninsula margin. geological society of america annual meeting, philadelphia 22-25 october, 2006, geological society of america abstracts with programs, 38 (7), p. 489. elofson o. (1941) zur kenntnis der marinen ostracoden schwedens mit besonderer berücksichtigung des skageraks. zoologiska bidrag fran uppsala, 19, pp. 215-534. faranda c. & gliozzi e. (2008) the ostracod fauna of the plio-pleistocene monte mario succession (rome, italy). boll. soc. paleont. ital., 47 (3), pp. 215-267. freiwald a., mostafawi b. & mostafawi n. (1998) ostracods in a cold-temperate coastal environment, western tromsǿ, northern norway: sedimentary aspects and assemblages. facies, 38, pp. 255-274. gibbard p. l., head m. j., walker m. j. c., & the subcommission on quaternary stratigraphy (2010) formal ratification of the quaternary system/period and the pleistocene series/epoch with a base at 2.58 ma. journal of quaternary science, 25 (2), pp. 96-102. gignoux m. (1910) sur la classification du pliocène ed du quaternaire dans l’italie du sud. c. r. acad. sci. paris, 150, pp. 841-844. gignoux m. (1913) les formations marines du pliocènes et quaternaires de l’italie du sud et de la sicile. ann. univ. lyon, n.s., 36, pp. 1-693. greco a., ruggieri g. & sprovieri r. (1974) la sezione calabriana di monasterace (calabria). boll. soc. geol. it., 93, pp. 151-179, roma. hanai t. (1977) future problems for systematics study of japanese ostracods. in: hanai t., ikeya n., ishizaki k. sekiguchi y & yajima m. (eds.) check-list of ostracoda from japan and its adjacent seas. the university of tokyo, bulletin, 12, pp. 1-5. hansson h.g. (comp.) (1998) neat (north east atlantic taxa): south scandinavian marine crustacea check-list. internet pdf ed., aug. 1998 [http:// www.tmbl.gu.se]. hazel j.e. (1967) classification and distribution of the recent hemicytheridae and trachyleberididae (ostracoda) of northereastern nord america. geol. surv. profess. paper, 564, pp. 1-50. horne d.j. & whittaker j.e. (1985) a revision of the genus paradoxostoma fischer (crustacea; ostracoda) in british waters. zool. j. linn. soc., 85, pp. 131-203. hulings n.c. (1966) marine ostracoda from western north atlantic ocean off the virginia coast. chesapeake science, 7 (1), pp. 40-56. hull s.l. (1998) the distribution and assemblage composition of the ostracod fauna (crustacea: ostracoda) on filey brigg, north yorkshire. j. nat. hist., 32 (4), pp. 501-520. iaccarino s.m., premoli silva i., biolz m., foresi l.m., lirer f., urco e. & petrizzo m.r. (2007) practical manual of neogene planktonic foraminifera. international school on planktonic foraminifera. vi course: neogene. perugia (italy), february 19-23, 2007, pp.1-181. ingv operational oceanography group, italy (2008) mediterranean ocean forecasting system. a revision of the “northern guest” ostracoda (crustacea) occurrence in the quaternary of the … 91 http://gnoo.bo.ingv.it/mfs/analysis_archive.htm jellinek t., swanson k. & mazzini i. (2006) is the cosmopolitan model still valid for deep-sea podocopid ostracoda? (with the description of two new species of pseudobosquetina guernet & moullade 1994 and cytheropteron testudo sars 1869 as case studies). senckenberg. maritima, 36 (1), pp. 29-50. kuhlemann j., rohling e. j., krumrei i., kubik p., ivyochs s., kucera1 m. (2008) regional synthesis of mediterranean atmospheric circulation during the last glacial maximum. science, 321, pp. 13381339. lamarck j.b. (1818) histoire naturèlle des animaux sans vertèbres, presentant les caractères generaux et particuliérs de ces animaux. 1st édition, pp. 1-612, paris. lourens l., hilgen f., & raffi i. (1998) base of large gephyrocapsa and astronomical calibration of early pleistcene sapropels in odp sites 967 and 969: solving the chronology of the vrica section. proceedings of the ocean drilling program, scientific results, 160, pp. 191-197. lourens l., hilgen f., schackleton n.j., laskar j. & wilson d. (2004) the neogene period. in gradstein f.m, ogg j.g. & smith a.g. (eds.), a geologic time scale 2004. cambridge university press, pp. 409-440. mackiewicz a. (2006) recent benthic ostracoda from hornsund, south spitsbergen, svalbard archipelago. polish polar res., 27 (1), pp. 71-90. malatesta a. & zarlenga f. (1986) northern guests in the pleistocene mediterranean sea. geol. romana, 25, pp. 91-154. malz h. (1989) cenozoic ostracodes of the vøring plateau (odp leg 104, sites 642, 643 and 644. proc. ocean drill. progr., scient. res., 104, pp. 769-775. malz h. & jellinek t. (1984) marine plio-pleistozän ostracoden von se-lakonien (peleponnes, griechenland). senckenbergiana biologica, 65 (1/2), pp. 113-167. mars p. (1958) les faunes malacologiques froides de la mediterranée: le gisement du cap créus. vie et milieu, 9, pp. 239-309. mascarelli a.l. (2009) quaternary geologist win timescale vote. redefinition rescues once-threatened terminology from extinction. nature, 459, p. 624. moncharmont-zei m., russo b., sgarrella f., bonaduce g. & mascellaro p. (1985) paleoclimatic record from 4 cores (gulf of taranto, ionian sea). evidence from foraminifera and ostracoda. boll. soc. paleont. it., 23 (1) (1984), pp. 21-51. mostafawi n. (1981) marine ostracoden aus dem oberpliozän im mittelteil der insel kos (griecheland). meyniana, 33, pp. 133-188. mostafawi n. (1986) pleistozäne ostracoden aus der nikolaos-formation von ost-kos, griecheland. senckenberg. lethaea, 67 (1/4), pp. 275-303. mostafawi n. (1989) limnische und marine ostracoden aus dem neogen der insel rhodos (griecheland). cour. forsch. senckenberg., 113, pp. 117-157. muller o.f. (1785) entomostraca seu insecta testacea, quae in aquis daniae et norvegiae reperit, descriptis et iconibus illustravit. 135 pp, leipzing & copenhagen. neale j. (1970) the marine flora and fauna of the isles of scilly: crustacea: ostracoda. j. nat. hist., 4 (3), pp. 399-413, london. norman a.m. (1865) report on the crustacea. in: brady g.s. (ed.), reports of deep sea dredging on the coasts of northumberland and durham, 1862-64. nat. hist. trans. northumb., 1 (1), pp. 12-29. norman a.m. (1869) shetland final dredging report. part 2. on the crustacea, tunicata, polyzoa, echinodermata, actinozoa, hydrozoa and porifera. rep. brit. ass. advmt. sci., pp. 247-336; 341-342. ogg j. (ed.) (2007) overview of global boundary stratotype sections and points (gssp’s). http://www. stratigraphy.org/gssp.htm. pasini g. & colalongo m.l. (1994) proposal for the erection of the santernian/emilian boundary-stratotype (lower pleistocene) and new data onn the pliocene/pleistocene boundary-stratotype. boll. soc. paleont. ital., 33 (1), pp. 101-120. penney d.n. (1993) northern north sea benthic ostracoda: modern distribution and palaeoenvironmental significance. the holocene, 3 (3), pp. 241-254. pillans b & naish t. (2004) defining the quaternary. quat. sci. rev., 23, pp. 2271-2282. pucci a. (1956) ostracodi pleistocenici della valle del tronto. giorn. geol., 2, 25, pp. 163-172. raymo m.e., ruddiman w.f., backman j., clement b.m. & martinson d. (1989) late pliocene variation in northern hemisphere ice sheets and north atlantic deep water circulation. palaeoceanogr., 4, pp. 413-446. rio d., sprovieri r., castradori d. & di stefano e. (1998) the gelasian stage (upper pliocene): a new unit of the global standard chronostratigraphic scale. episodes, 21, pp. 82-87. ruggieri g. (1952a) gli ostracodi delle sabbie grigie quaternarie (milazziano) di imola. parte ii. giorn. geol., 2, 22, pp. 59-115. ruggieri g. (1952b) la fauna calabriana di cosenza. giorn. geol., 2, 22, pp. 118-127. ruggieri g. (1956) ospiti nordici del quaternario italiano non elencati dal gignoux 1913. actes du iv congrès international du quaternaire, pp. 356-358. ruggieri g. (1959) enumerazione degli ostracodi marini del neogene, quaternario e recente italiani descritti o elencati nell’ultimo decennio. atti soc. it. sci. nat., 98 (2), pp. 173-198. ruggieri g. (1971) ostracoda as cold climate indicators in the italian quaternary. in: oertli h.j. (ed.) paléoécologie des ostracodes. bull. centre rech. pau-snpa, 5 (suppl.), pp. 285-293. ruggieri g. (1973) gli ostracodi e la stratigrafia del pleistocene mediterraneo. boll. soc. geol. it., 92, pp. 213-232. ruggieri g. (1974) ostracofauna delle calcareniti bianche quaternarie delle falde (palermo). riv. min. sic., 142/144, pp. 160-170. ruggieri g. (1975) revisione della ostracofauna marina quaternaria di imola (bologna). rev. esp. micropaleont., 6 (3), pp. 419-446. ruggieri g. (1976) la ostracofauna pleistocenica della falesia di cinisi (sicilia). boll. soc. paleont. ital., 15 (1), pp. 85-106. ruggieri g. (1977) nuovi ostracodi nordici nel pleistocene della sicilia. boll. soc. paleont. ital,. 16 (1), c. faranda & e. gliozzi 92 pp. 81-85. ruggieri g. (1978) individuazione del pleistocene basale nella sezione di castrocaro (forlì). boll. soc. geol. it., 95, pp. 881-890. ruggieri g. (1980) sulla distribuzione stratigrafica di alcuni ostracodi nel pleistocene italiano. boll. soc. paleont. ital., 19 (1), pp. 127-135. ruggieri g. (1991) gli ostracodi nell’opera di giuseppe seguenza. acc. pelor. pericolanti. classe di sci., fis. mat. nat., 67 (suppl. 1), pp. 41-77. ruggieri, g. (1996): un elenco di ostracodi fossili del neogene e del quaternario della romagna. quad studi nat. romagna, 6 pp. 1-10. ruggieri g. & d’arpa c. (1993): ostracodi marini del pliocene superiore di altavilla (palermo). contributo primo. naturalista siciliano, 4, 17 (3-4), pp. 195-229. ruggieri g. & sprovieri r. (1977) a revision of italian pleistocene stratigraphy. geol. romana, 16, 131139. ruggieri g., buccheri g., greco a. & sprovieri r. (1976) un affioramento di siciliano nel quadro della revisione della stratigrafia del pleistocene inferiore. boll. soc. geol. it., 94, pp. 889-914. ruggieri g., unti a., unti m. & moroni m.a. (1977) la calcarenite di marsala (pleistocene inferiore) e i terreni contermini. boll. soc. geol. it., 94, pp. 1632-1657. ruggieri g., rio d. & sprovieri r. (1984) remarks on the chronostratigraphic classification of the lower pleistocene. boll. soc. geol. it., 103 (2), pp. 251-159. seguenza g. (1883-86) gli ostracodi del quaternario di rizzolo. il natur. sic., 2-5. sars g.o. (1866). oversigt af norges marine ostracoder. forhandlinger videnskab-selskabet kristiania, pp. 1-130. sars g.o. (1869). nye dybvandscrustaceer fra lofoten. forhandlinger i videnskabs-selskabet i christiania. 147-174. sars g.o. (1925). an account of the crustacea of norway. 9. ostracoda. pars. 11-12 (cytheridae (continued). bergen museum, norway, pp. 177-208. sars g.o. (1928). an account of the crustacea of norway. 9. ostracoda. pars. 15-16 (cytheridae (concluded). bergen museum, norway, pp. 209-240. sissingh w. (1972) late cenozoic ostracoda of the south-aegean island arc. utrecht micropaleont. bull., 6, pp. 1-187. sissingh w. (1973a) the ostracode fauna of the type calabrian deposits at santa maria di catanzaro (s. italy). newsl. strat., 3, pp. 25-44. sissingh w. (1973b) the ostracode fauna of the type sicilian (quaternary) deposits of ficarazzi. proc. kon, ned. akad wetensch., b, 76 (4), pp. 341-357. sissingh w. (1976) tentative middle miocene to holocene ostracode biostratigraphy of the central and eastern mediterranean, i and ii. proc., kon. ned. akad. wetensch., b, 79 (4), pp. 271-299. stepanova a., taldenkova e., bauch h.a. & simstich j. (2003) recent ostracoda of the laptev and kara seas as indicators of bottom water environments. egs-agu-eug joint assembly, nice, france, 6-11 april, 2003, abstract book, p. 7718s. suc j.p., bertini a., leroy s.a.g. & suballyova d. (1997) towards a lowering of the pliocene/pleistocene boundary to the gauss-matuyama reversal. quat. internat., 40, pp. 37-42. suess e. (1883-1909) das antlitz der erde. 3 vv. swanson k.m. & ayress m.a., 1999 cytheropteron testudo and relates species from the sw pacific with analyses of their soft anatomies, relationships and distribution (crustacea, ostracoda, cytheruridae). senckenber. biologica, 79 (2), pp. 151-193. sylvester-bradley p.c. (1941) shell structure of the ostracoda. the annals and magazine of natural history, 11th series, 8, pp.1-33. tsapralis v. (1981) contribution to the study of pleistocene of zakinthos island, west greece. thèse, université de patras. vai g.b. (1996)revisione critico-storica dei piani marini del quaternario. serv. geol. it. miscellanea, 6, pp. 1-179. wagner c.w. (1957) sur les ostracodes du quaternaire recent des pays-bas et leur utilization dans l’étude géologique des depots holocènes. 158 pp., mouton & co., the hague. whatley r.c., eynon m. & moguilevsky a. (1996) recent ostracoda of the scoresby sound fjord system, east greenland. rev. esp. micropaleont., 28, pp. 5-23. whatley r.c., eynon m. & moguilevsky a. (1998) the depth distribution of ostracoda from the greenland sea. j. micropaleontol., 17, pp. 15-32. yassini i. (1969) ecologie des associations d’ostracodes du bassin d’arcachon et du littoral atlantique. bull. inst. géol. bassin d’aquitaine, 7, pp. 1316. yassini i. (1979) répartition des ostracodes dans une série marine régressive d’âge pliocène dans la région d’algérie. rev. micropaléont., 22 (2), pp. 89-124. ms. ricevuto il 4/05/2010 testo definitivo ricevuto il 7/09/2010 ms. received: may 4, 2010 final text received: september 7, 2010 amq abs pascucci et al saccom 181-184.pub available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 181 184 late quaternary stratigraphy of western sardinia (central mediterranean) based on luminescence age dating vincenzo pascucci 1, stefano andreucci 2, daniele sechi 1, leonardo casini 2 1 dipartimento di architettura, design e urbanistica, università di sassari, sassari, italy 2 diparimento di scienze chimiche e geologiche, università di cagliari, cagliari, italy 3 dipartimento di chimica e farmacia, università di sassari, sassari, italy corresponding author: v. pascucci <pascucci@uniss.it> abstract: we present the revised stratigraphic setting of the late quaternary deposits cropping out along the western coast of sardinia (italy). the height defined units have been dated using luminescence. keywords: osl, climate changes, eemian, marine isotopic stages 1. introduction numerous scientific models suggest that in 2100 the global temperature will be about 2 °c higher than today, with consequent rise of the sea level (antonioli et al., 2017). main effect of these rapid variations will result in a radical change of the coastal geography of the entire planet. however, no one model considers: 1) the adaptability of natural systems to the new physical conditions, 2) the differences between less and more urbanized coasts and, 3) the behaviour of areas with different tectonic regimes. investigating how the coastal plains reacted in the past in response to climate changes is one of the keys to hypothesise possible future scenarios in the short/medium term (amorosi et al., 2018). it is therefore necessary an accurate study of the climate/ sea-level changes of the past glacial-interglacial cycles and recent warm-cold holocene fluctuations to improve the climate-changes future projections. to define the coastal response to the high and very high frequency glacio-eustatic fluctuations of the late quaternary (last 300 ka) and in particular of the last interglacial (125-85 ka) becomes of utmost importance (amorosi et al., 2005; vacchi et al., 2016). the marine palaeosea level markers consist of various erosive (tidal notches, raised marine terraces), sedimentary (palaeo-beaches and coral reefs) and stratigraphic (transgressive/regressive successions) features useful to estimate the palaeo-sea level (de muro & orrù, 1998; pascucci et al., 2009; antonioli et al., 2015). they, however, are reliable if used in tectonically stable areas and precisely age dated. the use of an absolute dating methodology for these sedimentary and stratigraphic marine palaeosea-level markers may provide a unique opportunity to precisely define the chronology of the response of the coastal systems to sea-level changes, and define the climatic changes occurred from the middle pleistocene. 2. material and methods the west and northwest coasts of sardinia have been chosen as a case study, because the island is generally considered stable, being tectonically inactive since 1 ma (fig. 1). the adopted absolute dating methodology is the luminescence (murray & wintle, 2000; buylaert et al., 2011). the west and northwest coasts of sardinia are quasi continuously draped by late quaternary strata overlapping the older substrate. they have been referred by authors to either the tyrrhenian interglacial, if characterised by marine deposits resting above the present sea level, or to the “wurmian” glacial if continental. just few are referred to the “riss” glacial phase (carboni & lecca, 1985; carmignani et al., 2001). according to the modern marine isotope stratigraphy (mis) adopted for quaternary studies, a deep review of the stratigraphy, especially adopting absolute dating methodologies is needed. fig. 1 sardinia island (italy) in the center of the mediterranean sea. https://doi.org/10.26382/aiqua.2018.aiquaconference given the limit of 14c for dating sedimentary deposits older than 45 ka, several different dating methods have been recently tested to date the late quaternary succession of west and northwest sardinia (i.e. u/th, aminoacid racemisation, and luminescence) (i.e. andreucci et al., 2009, 2010, 2014, 2017; thiel et al., 2010). however, due to the clastic nature of these deposits, the luminescence is the most suitable methodology. the method estimates the time elapsed since the last exposure to sunlight of quartz (optically stimulated luminescence) and alkali feldspar (post ir irsl 290) grains and thus enabling us to constrain the burial time. 3. results and discussion the revised late quaternary stratigraphy of the west and northwest coasts of sardinia enabled us to identify the role played by sea level and climate changes, in controlling sedimentation. the luminescence dated outcropping succession, has been grouped into eight major stratigraphic units mainly represented by coastal dunes, shallow marine and alluvial systems (pascucci et al., 2014). these units range in age from mis 8 (300 ka) to mis1 (last 11.8 ka) (fig. 2). data provided are not useful to clearly define what happened between mis 8 and 7. it is, however, worthy to note that in some areas marine mis7 deposits crop out above the present sea level. this could imply that the claimed tectonic stability of the island needs to be revised. mis6 deposits are scattered and discontinuous. they are mostly made by gravity flow and occasional wind dominated systems. a better dataset encompasses the last 125 ka and allows inferring the climatic events occurred during the last interglacial (mis 5) and glacial (mis 4-2) times. mis5 is subdivided in five substages (e-a). mis5e (eemian) is considered the climate optimum of this interglacial. in sardinia the sea level was 4-6 m higher than today and climate conditions were warmer and more humid. during this high stand sea level, not many beaches developed, whereas tidal notches and bioherms were common. the last have been herein dated for the first time with luminescence and range in age from 138 to 114 ka. mis 5c (110 -95 ka) is the second high stand peak. the error of the luminescence technique, however, does not allow discriminating mis5e and 5c. the stratigraphic data, in any case, indicate that around 100 ka a sea level still stand occurred. during this time, the sea level was about 1.5 m higher than todays, several sandy beaches developed, and palaeoclimatic and palaeogeographic conditions were similar to the present time. during the following mis 4, at the beginning of the glacial phase, a climatic deterioration occurred; temperature decreased of about 6 °c with respect to mis 5e. luminescence datings indicate that this deterioration was brief and rapid (5 to 10 ka). as a result, the sea level drops of about 60 m, the inland vegetation cover progressively educed, and a denudation of valley slopes repeatedly occurred. the sea-level fall created the accommodation space for the development of alluvial fans in sheltered and cliffy areas, where debris flows accumulated and filled almost completely the terminal parts of the narrow coastal valleys/coves, while on wider areas coastal dune fields developed. contemporaneous occurrence of alluvial fan and dune systems is associated to the local morphology that could mitigate or amplify some moistly conditions in a general arid environment. during mis 3 alternate deposition of alluvial/fluvial and aeolian sediments document the occurrence of several climate fluctuations. they could be related with the wet/arid, d/o-h events (heinrich & dansgaard– oeschger events) that have been recognised in the cold mis3 (pascucci et al., 2014). these fluctuations, each 182 pascucci v. et al. fig. 2 relationships and main features of the eight unconformity bounded units cropping out along the west and northwest coast of sardinia. units cover the last 300 ka. right columns report the estimated sea level elevations and temperatures from marine isotopic stage 5 (mis 5) to mis1 (modified after pascucci et al., 2014). lasting about 10 ka, are beyond the luminescence resolution. according to the available dating, we could just document that the shallow sardinian shelf was continuously exposed throughout the mis3, being the source area of bioclastic sands. these sands were blown inland, and formed extensive dune field systems. dunes dominated the west coast of sardinia under cold and relatively dry conditions. in some areas, these dune field systems were eventually almost completely dismantled and reworked into water-flow dominated alluvial fans by catastrophic rainfall events occurred during relatively more humid conditions. thus, the local climate quickly switched from arid to humid. no record of the last glacial maximum deposits, mis 2, was observed along the nw sardinian coast. submarine data just confirm that the lowest sea level was of -120 m below the present. during the holocene transgression (mis 1) the coastline progressively migrated landward as the coastal dune systems did. the temperature aumented, reaching almost the present-day values around 6ka. since this time onward, little sea-level and climatic fluctuations occurred, leading to transgressive/regressive cycles of few thousands of years. mis1 deposits have been dated, when possible, also using 14c technique (pascucci et al., 2018). this cross-methodology has always proven the reliability of the results obtained by means of the luminescence method. 4. conclusions we have documented that late quaternary continental and shallow marine deposits may be dated using luminescence methodology both on quartz and kfeldspar grains. at the moment the erorr comprised between 10 and 5% does not allow distinguishing high frequency cycles of the order of 10 to 5 ka, but just to claim their existence. acknowledgements the authors thanks alessandra negri for the provided review that helped to improve the manuscript. this work was supported by: accordo di cooperazione ex art. 15 della legge 7, agosto 1990 n. 241 between the municipality of alghero, manager of marina protected area “capo caccia – isola piana” and department of architecture, design and planning of the university of sassari (resp. prof. vincenzo pascucci). references amorosi a., centineo m.c., colalongo m.l. fiorini f. (2005) millennial-scale depositional cycles from the holocene of the po plain, italy. mar. geo., 222 -223, 7-18. amorosi a., bruno l., campo b., morelli a., rossi v., scarpon, d., hong w., bohacs k.m., drexlercet t.m. (2017) global sea-level control on local parasequence architecture from the holocene record of the po plain, italy. marine and petroleum geology, 87, 99-111. andreucci s., pascucci v., murray a.s., clemmensen l.b. (2009) late pleistocene coastal evolution of san giovanni di sinis (west sardinia, western mediterranean). sed. geo., 216, 104-116. andreucci s., clemmensen l.b., pascucci v. (2010) transgressive dune formation along a cliffed coast at 75 ka in sardinia, western mediterranean: a record of sea-level fall and increased windiness. terra nova 22, 424-433. andreucci s., panzeri l., martini i.p., maspero f., martini m., pascucci v. (2014) evolution and architecture of a west mediterranean upper pleistocene to holocene coastal apron-fan system. sedimentology, 61, 333-361 andreucci s., sechi d., buylaert j.p, sanna l., pascucci v. (2017) post-ir irsl290 dating of k-rich feldspar sand grains in a wind-dominated system on sardinia. marine and petroleum geology, 87, 91-98. antonioli f., anzidei m., amorosi a., lo presti, v., mastronuzzi g., deiana g., de falco g., fontana a., fontolan g., lisco s., marsico a., moretti m., orr, p.e., sannino g.m., serpelloni,e., vecchio a. (2017) sea-level rise and potential drowning of the italian coastal plains: flooding risk scenarios for 2100. quaternary science reviews, 158, 2943. antonioli f., lo presti v., rovere a., ferranti l., anzidei m., furlani s., mastronuzzi g., orrù p.e., scicchitano g., sannino g., spampinato c.r., pagliarulo r., deiana g., de sabatam e., sansòn p., vacchi m., vecchio a. (2015) tidal notches in mediterranean sea: a comprehensive analysis. quaternary science reviews, 119, 66-84. buylaert j.p., huot s., murray a.s., van den haute p. (2011) infrared stimulated luminescence dating of an eemian (mis 5e) site in denmark using kfeldspar. boreas 40, 46-56. carboni s., lecca l. (1985) osservazioni sul pleistocene superiore della penisola del sinis (sardegna occidentale). boll. soc. geol. it., 104, 459-477. carmignani l., barca s., oggiano g., pertusati p.c., salvadori i., conti p., eltrudis a., funedda a., pasci s. (2001) note illustrative della carta geologica della sardegna a scala 1:200.000. memorie descrittive carta geologica italiana, 60. istituto poligrafico e zecca dello stato, roma, pp. 283. de muro s., orrù p. (1998) il contributo delle beachrock nello studio della risalita del mare olocenico. le beach-rock post-glaciali della sardegna nordorientale. il quaternario, 11, 19-39. murray a.s., wintle a.g. (2000) luminescence dating of quartz using an improved single-aliquot regenerative-dose protocol. radiat. meas., 32, 57-73. pascucci v., martini i. p, endres a. (2009) facies and ground-penetrating-radar (gpr) characteristics of coarse-grained beach deposits of the uppermost pleistocene glacial lake algonquin, ontario canada. sedimentology, 56, 529-545. pascucci v., de falco g., del vais c., melis r., sanna i., andreucci s. (2018) climate changes and human impact on the mistras coastal barrier system (w sardinia, italy). mar. geo., 395, 271284. pascucci v., sechi, d., andreucci s. (2014) middle pleistocene to holocene coastal evolution of nw 183 late quaternary stratigraphy of western sardinia sardinia (mediterranean sea, italy). quat. int., 328 -329, 3-20. thiel c., coltorti m., tsukamoto s., frechen m (2010) geochronology for some key sites along the coast of sardinia (italy). quat. int. 222, 36-47. vacchi m., marriner n., morhange c., spada g., fontana a., rovere a. (2016) multiproxy assessment of holocene relative sea-level changes in the western mediterranean: sea-level variability and improvements in the definition of the isostatic signal. earth-science reviews, 155, 172-197. 184 pascucci v. et al. ms. received: may 7, 2018 final text received: may 14, 2018 amq 31(1) 37-47 panarello et al proofcopy available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 31 (1), 2018, 37 47 the devil’s touch: a first dataset from what could be the oldest human handprint ever found (central-southern italy) adolfo panarello,1 luigi mazzardo2, paolo mietto3 1 lab. ricerche storiche e archeologiche dell’antichità, dip. scienze umane, sociali e della salute, università degli studi di cassino e del lazio meridionale, cassino (fr), italy 2 via pinchera 3, cassino (fr), italy 3 dipartimento di geoscienze, università degli studi di padova, padova, italy corresponding author: a. panarello <adolfo.panarello@unicas.it> abstract: this paper aims to report about all collected data and information on the human handprint firstly identified at tora e piccilli palaeoichnological site (tora-piccilli, caserta, central italy) i.e. within the same site in which middle pleistocene (about 350 ka) human fossil footprints (the so called “devil’s trails”) are preserved. as well-known, these footprints are not randomly patterned, but are organized into at least two long trackways, called a and b. during first surveys of the site, in the middle of the trackway b, aside the traces of a long fossil slide, it was noted a hollow: it was preliminary thought to be the print of a left hand used by the trackmaker to regain lost balance. even if this possibility seemed to be very probable, it has remained a simple hypothesis and has been, for a long time, waiting for a scientific confirmation. after many years of careful studies, we have enough data to confirm that the first impression was correct and to report about what is, so far, the oldest human fossil handprint in the world. a first set of dimensional data is also given. they are precious in the sight of each future study about the upper limbs of prehistoric humans. keywords: fossil, handprint, roccamonfina footprints, devil’s trails 1. introduction the human fossil footprints, commonly known as "devil's trails", were discovered in 2001 on a deposit of brown leucitic tuff (blt) located in the roccamonfina volcanic area (central-southern italy) [41° 19.954'n 14° 1.489'e] (fig. 1), and published by mietto et al. (2003). at the time of their first publication, they were the oldest established human footprints left by some exemplars of the genus "homo" (mietto et al., 2003; avanzini et al., 2008). currently, even after the discovery of other older human footprints at ileret/koobi fora (kenya) (bennett et al., 2009), at happisburgh (uk) (ashton et al., 2014).) and, probably, at aalad-amo (eritrea) (en.uniroma1.it/archionotizie/homo-erectusextraordinary-footprints), the "devil's trails" remain among the oldest ever found in the whole world, since they have been radiometrically dated at 349±3 ka by 40ar/39ar method (scaillet et al., 2008; santello, 2010). the "devil’s trails" are associated with paleofauna footprints of the same age (panarello et al., 2017b; palombo et al., 2018) and, unlike all the other human fossil footprints known up to now, are not located on a flat or moderately inclined surface, but on a very steep slope (fig. 2a) which, in some areas, also reaches inclination close to 80%. moreover, the same footprints are not randomly organized but are patterned in several trackways (mietto et al., 2003; avanzini et al., 2008). in particular, the trackway a and the trackway b are both descending and branch off from a fossil pathway that fig. 1 location of the tora and piccilli (“devil’s trails”) geosite. https://doi.org/10.26382/amq.2018.03 38 panarello a. et al. fig. 2 a) devil’s trails geosite: western view of the steep slope of blt on which the fossil footprints and handprints are preserved; b: pattern of the trackway a (scale-bar: 1 m); c) pattern of the trackway b (scale-bar: 1 m). 39 the oldest human handprint dominates the whole slope. this pathway has been proven to be the oldest in the world to date (panarello et al., 2017a). trackway a and trackway b have very particular patterns that cannot be so far compared to similar ones in the entire world (fig. 2 b, c). these patterns clearly reflect the conscious behavioral choices that the two trackmakers had to make to preserve their balance during the descent of an unsafe, sloping and slippery slope. the trackmaker a descended in a "zig-zag" way, describing a "z" shaped route (fig. 2b). the trackmaker b, due to misleading and unsafe ground, which was not regularly dry (as revealed by mud-crack areas) (fig. 3), slipped for more than 90 cm losing his/her balance, but he/she did not fall: this is revealed by the total absence of traces of an impact on the surrounding ground (fig. 2c). during the slide, in order to regain the lost balance, he/she had to rest his/her left hand and also his/her pelvis on the upstream side in order to proceed with his/ her descent (fig. 4). based on this evidence, the small deep and elongated cavity, located to the left of the slide, was firstly interpreted as the print left by the carpal area of a left hand. indeed, it has rounded edges and lies in a fig. 3 the left hip impact zone in the middle part of the trackway b, with very evident preserved mud-crack. >>>>>>>>> fig. 4 the middle area of the trackway b, with the long slide, the tp_m1 handprint and some footprints (scale-bar: 1 m; contour lines: 1 mm). position compatible with the estimated height of hominine b (mietto et al., 2003; avanzini et al., 2008). although this interpretation immediately seemed the most realistic, it was decided to proceed with a more in-depth study by applying also the most innovative techniques according to the most recent palaeontological protocol (falkingham et al., 2018), in order to carry out all necessary checks for its final authentication. thus, through 3d modelling, carried out on the basis of highly detailed photogrammetric surveys, it was possible to see that the print of some parts of all trackmaker’s left hand five fingers are visible. these prints branch from the most evident carpal hollow. although the degree of preservation is not the same for all fingerprints and each measurement always must be considered interpretative, the dimensional collected data seem to be certainly compatible with those up to now known for humans (garrett, 1971; marzke & shackley, 1986; aiello & dean, 1990; mchenry, 1992; lorenzo et al., 1999; 2015; marzke & marzke, 2000; jones & lederman, 2006; buryanov & kotiuk, 2010; gilsans & ratib, 2012; almécija et al., 2015). scientists' first impression was, hence, correct. so, the provided both structural and dimensional details which are given here, as they are referred to such an antique handprint, called tp_m1 ("tora and piccilli's manus 1"), may reveal precious for any further study. 2. methods, techniques the handprint tp_m1 and its immediate surroundings were georeferenced with a garmin etrex 10 detector (accuracy ±3 m) and carefully photographed through canon powershot g9 and canon eos 550d camera with canon ef-s 18-200 lens. then all the pictures were processed with agisoft photoscan pro and kitware paraview to create detailed 3d models of the general examined surface following the procedures of mallison & wings (2014) and belvedere et al. (2013). these models have been scaled through a metallic 10 cm scale-bar. each parameter of the figured models is shown in table 1 according to the method of lockley et al. (2015). 3. description if we observe the hollow referable to the carpal zone of a left hand, which is the most evident part of the handprint tp_m1, we immediately notice that the whole handprint was created by the trackmaker during an unexpected slide on the slimy ground. moreover, it appears completely and very easily superimposable by the left hand of a young boy/girl or by the left hand of a minute woman of present time. the prehistoric hand of the middle pleistocene trackmaker, indeed, was already anatomically structured in the way we know for present humans and fully coordinated with the brain. also, it was completely capable to do simple and/or complex movement, to achieve a result thought and desired (jones and lederman, 2006; navsa, 2010; gilsans & ratib, 2012). for these reasons and considering that the human hand is the upper limb that has changed less during evolution (marzke & shackley, 1986; aiello & dean, 1990; mchenry, 1992; marzke & marzke, 2000; almécija et al., 2015), a glance is sufficient to imagine the moments of the hand's support on the muddy steep ground without straying too far from reality. the most evident part of the tp_m1 handprint (figs. 5, 6, 7, 8) is elliptical in shape, with flared and 40 tab. 1 parameters of the photogrammetric models of the handprint tp_m1 and of its immediate surroundings. fig. 5 tora and piccilli geosite: western detail photo of the carpal zone of the handprint tp_m1. panarello a. et al. smoothed edges. this part is limited downstream by a quite semicircular displacement rim. the direction of the major axis of the handprint is incident to the progression line of trackway b that here runs southeast. the rear area of the handprint shows the signs of an anteromedial slip oriented towards the incline, while the distal area shows the signs of an irregular compression loaded onto the front. in this area a series of small, elongated and partially irregular in shape depressions aligned in 5 directions is visible. each depression is divided into several segments: they are, in number, 3 for the 4 directions corresponding to fingers 2-5 and 2 for the direction corresponding to the thumb. the directions of the 5 fingerprints appear patterned in an irregular way. this could be explained by considering that they were likely created as a consequence of the responding to an instinctive impulse, which was induced by the unexpected loss of the general balance. for the same reason, the greater load was carried on the carpo-phalangeal area of the first and second fingers (fig. 8), whose prints are the best preserved ones. the dimensional and structural details of each element, as interpreted by us, are shown in tables 2 and 3. in reading and evaluating them, it should be taken into the right account that the collected dimensions refer to the handprint and not to the bones or to precise muscles and joints, so they can slightly vary with respect to those recorded by corresponding hand bones. they are also affected by the substantial irregularity of the solidification and alteration of the substrate, which is very evident somewhere within the geological site (avanzini et al., 2008). furthermore, it must be taken into the same account that the trackmaker was sliding and that put his/her left hand instinctively and 41 fig. 6 tp_m1 handprint: a) depth map with landmark positions; b) contour map (interval: 1 mm) with highlighted (red lines) the possible directions of the fingers; c) detailed landmark map. the oldest human handprint dynamically. for these reasons, the depression-areas created by the supports of the hand-joints may appear slightly dilated and/or deformed if compared to those usually recorded both for present and ancient men starting from their bones. the parts of the hand which are somehow uncertain in being recognized have been voluntarily ignored. the dimensions collected and shown in table 2 have been measured, hence, within the handprint area from what are likely one joint-zone to the following one. these zones have been identified by using the 3d models and the depth and planar contour maps shown in figs. 6, 7, 8. in order to mostly reduce the margin of error during interpretation of each linear length, the limits of the joint zones have been identified by different observers and, specifically, by one of the authors (l.m.), who is a m.d. hand surgeon. even if the cornerstones of each dimensional data preserve reasonable margin of interpretation, we think it can be considered affordable enough. similarly, the fingers widths have been measured as the straight distances between the interphalangeal joints edges, but only in the places in which such measurement can be considered affordable enough (fig. 8). these values are shown in table 3. finally, it has been measured the straight distance 42 tab. 2 handprint lenghts (conventions after artner, 2002) tab. 3 handprint widths (conventions after artner, 2002) fig. 7 contoured depth map in an oblique western view of the handprint tp_m1 (scale-bar: 10 cm). panarello a. et al. today in our everyday life (marzke et al., 1986; jones & lederman, 2006). and also the dimensional data are fully comparable to the present ones (garrett, 1971; navsa, 2010; vergara et al., 2017). the total length of each finger is not precisely measurable starting from the preserved evidence, because the distal edges are not objectively identifiable and because not all the interphalangeal-joint zones are objectively identifiable. between the edges of the muscle-pad corresponding to the metacarpal i, scaphoid and the trapezoid bones. this distance is ~5,4 cm and can likely match the hand of a present human specimen with a stature ranging from m. 1,50 to m. 1,65. this can also be very easily experimentally established (fig. 9). no angle between fingers seems to be precisely and objectively measurable since the hand is flexed in a forced and broken movement, but all the phalangeal longitudinal directions surely converge to the base of the wrist, as it normally happens in the human hand (garrett, 1971; navsa, 2010; vergara et al., 2017). 4. discussion as already pointed out, during any consideration about the hand it should be taken into the right account that the human hand is, probably, the limb that has developed the least degree of evolution (marzke & shackley, 1986; aiello & dean, 1990; mchenry, 1992; marzke & marzke, 2000; almécija et al., 2015). this allows us to affirm that the prehistoric human hand which left its print on the irregularly soft and muddy slope at tora and piccilli site was certainly much similar to the present one. this is clearly confirmed by the characteristics of the handprint which show an extremely flexible limb, already enabled to any movement, or system of movements, capable of performing each of the same gestures we do 43 fig. 9 experimental photo of the superimposition of present time left hand on the tp_m1 handprint (the hand photographed belongs to a female who is 1,56 m tall). fig. 8 3d model surface with (highlighted) the landmarks for the measurement of the finger widths. there have been also highlighted (dotted lines) the possible forms of the best preserved parts of the fingerprints. the oldest human handprint this is probably due to the fact that the maximum load of the body was put onto the wrist and the carpal zone of the left hand during the forward-medial oriented movement of the total body in the regaining of the lost balance. on the contrary, for the same reason they are very evident and well preserved the proximal and the distal carpal rows. the most remarkable load is also evident on the fingers i and ii (figs. 6, 7, 8, 9). the dimensional dataset collectible through direct measurements and through 3d modelling of trackmaker’s b hand, as reported in table 2 and table 3, do appear fully compatible with those of an actual human hand and fit the preliminarly estimated stature for the trackmaker b, i.e. ~156 cm (avanzini et al., 2008). the same data also fall within the range of anthropometric values known both for pleistocene hominins and present day humans (mc henry, 1992; marzke & marzke, 2000; buryanov & kotiuk, 2010; garrido varas & thompson, 2011; lorenzo et al., 2015; darowish et al., 2015; almécija et al., 2015 and quoted bibliography). specifically, the dimensions of tp_m1 seem to fit those of a juvenile exemplar (gaskin et al., 2011; gilsans & ratib, 2012) or, more generically, those of a small-sized exemplar of homo (panarello et al., 2017b). moreover, the angular movements of the wrist, do not exceed, respectively, the 15°-40° range for the abduction (radial deviation) and adduction (ulnar deviation), and this also confirms that tp_m1 is actually a human fossil handprint (ajello & dean, 1990). for the explained reasons, an affordable comparison could be done for the phalangeal proximal length of the index finger only and not in a wide range of cases, but this is actually impossible so far. indeed, even if findings of hand prints and hand marks are noticed, for different ages, in many scientific publications, very rarely they are accompanied by precise dimensional data and are only mentioned or documented by picture with or without a simple scale-bar. complete and/or partial handprints and handmarks are known in the cueva d’el castillo, spain (groenen et al., 2012); at willandra lakes, australia (webb, 2007); in the lhasa region, chinese tibet (zhang-li, 2002; meyer et al., 2017); in the grotte de lascaux, france (barrière & sahly, 1964); at ojo guareńa, spain (ortega, 2009); in the grotte du tuc d’audobert, france (vallois, 1927; beguen, 1927a, 1927b; bahn & vertut, 1988; beguen et al., 2009); in the grotte de fontanet, france (clottes, 1973, 1975, 1993; bahn & vertut, 1988; cohen, 2007); in the grotta della basura, italy (blanc & pales, 1960; de lumley & giacobini, 1985; rembado & vicino, 1985; citton et al., 2017); in the grotte de l’aldène, france (ambert et al., 2007; galant et al., 2007); in the grotte de ganties-montespan, france (garcia & morel, 1995); in the cueva temprana, llanes region, spain (lockley et al., 2008; rodriguez-asensio & noval fonseca, 2012), and elsewhere (janssens, 1957; delluc & delluc, 1985; guthrie, 2005; bennett & morse, 2014; panarello, 2016). however, like said above, only poor dimensional data can be taken from all these works and they are obtainable only from sometimes and somehow scaled pictures. nor can be used streaks, scratches and flutings to capture precise dimensions, as most of the other artistic and magic impressions, carvings and pictograms, which are almost completely located in the caves, are strictly linked to the use of fingertips only, or are contaminated by a conscious use of the hands and the fingers, so deforming and/or making unidentifiable any objective dimension of the anatomical parts of the hand. it also should be taken into the right account that many of the available papers have been published for a long time and/or are quite totally concentrated on the collection, analysis and interpretation of the footprints and/or to the artistic representations, giving very few attentions to the handprints. in this view, also some recent and well-done reports, like the one about the tibetan plateau ichnosite (meyer et al., 2017) gives no space and attention to the dimensions and to the morphology of the found handprints. the tibetan handprints could have been very precious for a comparison with the roccamonfina tp_m1 handprint, also for the environmental similarity: both of them, in fact, are preserved in open-air environments. for these reasons, no exhaustive comparison can be done at the present time and for this purpose. in this view, it would be very useful to reanalize all the known ichnosites preserving prehistoric fossil handprints by surveying them with new latest generation instruments and techniques. 5. conclusions the dimensional and morphostructural data, measured from the best preserved fossilised anatomical parts of the handprint tp_m1, and their full compatibility with the available dimensional and morphostructural ranges up to now known for hominins, allow us to to support that very likely the tp_m1 hollow is actually a prehistoric handprint. it was actually printed on an irregularly dry volcanic muddy slope by the left hand of a middle pleistocene small hominine, which was habitually biped, during the instinctive movements made to regain the lost balance after a sudden long slide. furthermore, the dating of tp_m1 at 349±3 ka (mietto et al., 2003; avanzini et al., 2008; scaillet et al., 2008; santello et al., 2010) makes it uncomparable, for antiquity, to any other handprint up to now known in the world as none of them is older than 30 ka (vallois, 1927; beguen, 1927a, 1927b; blanc & pales, 1960; barrière & sahly, 1964; clottes, 1973, 1975, 1993; de lumley & giacobini, 1985; delluc & delluc, 1985; rembado & vicino, 1985; bahn & vertut, 1988; garcia & morel, 1995; zhang-li, 2002; guthrie, 2005; ambert et al., 2007; cohen, 2007; galant et al., 2007; webb, 2007; lockley et al., 2008; beguen et al., 2009; ortega, 2009; groenen et al., 2012; rodriguez-asensio & noval fonseca, 2012; bennett & morse, 2014; panarello, 2016; citton et al., 2017; meyer et al., 2017). this evidence allows us to affirm that the tp_m1 may be considered as the oldest confirmed human fossil handprint known in the world so far. it is not comparable at this time with any other similar ones located both in sub-aerial and hypogeal environments. moreover, just like noted in the preliminary studies (avanzini et al., 2008), the handprint tp_m1 is completely free from any 44 panarello a. et al. cultural and magic needs, so that it can only be evaluated and analysed in a dynamic point of view by linking it to the trackmaker's pace. the great paleontological and mainly behavioral value of the handprint tp_m1, which was already intuited at the moment of its find (mietto et al., 2003; avanzini et al., 2008), is now confirmed by instrumental tests and re-launched with the addition of an anatomical/dimensional dataset, which could reveal precious for the study of similar evidence and contexts. being the result of an instinctive and absolutely not premeditated action, the tp_m1 handprints is a rare capture of a moment of middle pleistocene everyday life. in this way it can be also considered as a sort of quite one-of-a-kind photographic snapshot taken at any moment in a farthest past. acknowledgements the auhors thank ms. anna mariani for her final spell-check. the authors are also very thankful to maria rita palombo, andrea sposato and sarita amy morse for their precious comments and suggestions that increased the quality of the manuscript. references aiello l., dean c. (1990) an introduction to human evolutionary anatomy. london-san diego-new york-boston-sydney-tokyo-toronto. academic press, 309-341. almécija s., smaers j.b., jungers w.l. (2015) the evolution of human and ape hand proportions. + supplementary materials. nature communications,|6:7717|. doi: 10.1038/ncomms8717|1-11. ambert p., colomer a., galant p. (2000) datations mésolithiques des empreintes humaines de l'étage cathala de la grotte d'aldène (cesseras, hérault). comptes rendus de l'académie des sciences series ii a earth and planetary science, 331 (1), 67-74. ambert p., galant p., colomer a. (2001) incursions spéléologiques mésolithiques dans la grotte d'aldène (cesseras, hérault). bulletin de la société préhistorique française, 98 (3), 497-503. ambert p., galant p., guendon j.l., colomer a., dainat d., beaumes b., gruneisen a., requirand c., quinif y. (2007) les gravures et les empreintes humaines de la grotte d aldène (cesseras, hérault) dans leur contexte chronologique et culturel. bulletin du musée d'anthropologie préhistorique de monaco, 47, 3-36. artner j. (2002) atlas of human skeletal anatomy. ebook on www.juarjartner.com, pp.64. ashton n., lewis s.g., de groote i., duffy s.m., bates m., bates r., hoare p., lewis m., parfitt s.a., peglar s., williams c., stringer c. (2014) hominin footprints from early pleistocene deposits at happisburgh, uk. plosone, 9 (2), e88329. avanzini m., mietto p., panarello a., de angelis m., rolandi g. (2008) the devil’s trails: middle pleistocene human footprints preserved in a volcanoclastic deposit of southern italy. ichnos, 15, 179 -189. bahn p.g., vertut j. (1988) images of the ice age. leicester: winward, pp. 240. barriere c., sahly a. (1964) les empreintes humaines de lascaux, in miscelanea en homenaje al abate h. breuil, tome 1. barcelona: 172-180 + 8t. bégouën c.m. (1927a) les empreintes de pieds prehistoriques. institut international d’anthropologie, ii session, ii int. anth. arch. prehist., (amsterdam), 323-328 + 4 tab. bégouën c.m. (1927b) empreintes de doigts préhistoriques et de quelques dessins. institut international d’anthropologie, ii session, ii int. anth. arch. prehist., (amsterdam), 335-338. bégouën r., fritz c., tosello g., clottes j., pastoors a., faist f. (2009) le sanctuaire secret des bisons. il y a 14 000 ans, dans la caverne du tuc d'audoubert. paris: editions d'art somogy et l'association louis bégouën, pp. 416. belvedere m., jalil n.e., breda a., gattolin g., bourget h., khaldoune f., dyke g.j. (2013) vertebrate footprints from the kem kem beds (morocco): a novel ichnological approach to faunal reconstruction. palaeogeography, palaeoclimatology, palaeoecology, 383-384, 52-58. bennett m.r., harris j.w.k., richmond b.g., braun d.r., mbua e., kiura p., olago d., kibunjia m., omuombo c., behrensmeyer a.k., huddart d., gonzalez s. (2009) early hominin foot morphology based on 1,5 million year old footprints from ileret, kenya. science, 323, 1197-1201. bennett, m.r., morse, s.a., (2014) human footprints: fossilised locomotion? springer, london-chamheidelberg-new york-dordrecht. blanc a.c., pales l. (1960) le vestigia umane della grotta della bàsura a toirano. estratto dalla rivista di studi liguri, a. xxvi, 1-4, pp. 90. buryanov a., kotiuk v. (2010) proportions of hand segments. international journal of morphology, 28 (3), 755-758. citton p., romano m., salvador i., avanzini m. (2017) reviewing the upper pleistocene human footprints from the ‘sala dei misteri’ in the grotta della basura (toirano, northern italy) cave: an integrated morphometric and morpho-classificatory approach. quaternary science reviews, 169, 50-64. clottes j. (1973) midi-pyrénées. gallia préhistoire, 16 (2), 481-523. clottes j. (1975) midi-pyrénées. gallia préhistoire, 18 (2), 613-650. clottes j. (1993) ichnologie. in groupe de réflexion sur l’art pariétal paléolithique, paris: ministère de l’enseignement supérieur et de la recherche, 5966. cohen c. (2007) de la trace au tracé. les empreintes humaines préhistoriques. in thouard d. (ed.), l’interprétation des indices. enquête sur le paradigme indiciaire avec carlo ginzburg, villeneuve d’ascq: presses universitaires du septentrion, 211 -224. 45 the oldest human handprint darowish m., brenneman r., bigger j. (2015) dimensional analysis of the distal phalanx with consideration of distal interphalangeal joint arthrodesis using a headless compression screw. hand, 10, 100-104. de lumley m.a., giacobini g. (1985) le impronte di piedi umani. rivista di studi liguri, 51 (4), 362366. delluc b., delluc g. (1985) de l’empreinte au signe. histoire et archéologie, les dossiers: traces et messages de la prehistoire, 90, 56-62. falkingham p.l., bates k.t., avanzini m., bennett m., bordys e.m., breithaup b.h., castanera d., citton p., díaz-martínez i., farlow j.o., fiorillo a.r., gates s.m., getty p., hatala k.g., hornung j.j., hyatt j.a., klein h., lallensack j.n., martin a.j., mary d., matthews n.a., meyer c.a., milàn j., minter n.j., razzolini n.l., romilio a., salisbur s.w, sciscio l., tanaka i., wiseman a.l.a., xing l.d. and belvedere m. (2018) a standard protocol for documenting modern and fossil ichnological data. palaeontology. doi: 10.1111/pala.12373 galant p., ambert p., colomer a., guendon j.l. (2007) les vestiges d’éclairages préhistoriques de la galerie des pas de la grotte d aldène (cesseras, hérault). bulletin du musée d'anthropologie préhistorique de monaco, 47, 37-80. garcia m.a., morel p. (1995) restes et reliefs: présence de l’homme et de l’ours des cavernes dans la grotte de montespan-ganties, hautegaronne. anthropozoologica, 21, 73-78. garrett j.w. (1971) the adult human hand: some anthropometric and biomechanical considerations, human factors, 13 (2), 117-131. garrido varas c.e., thompson t.j.u. (2011) metric dimensions of the proximal phalanges of the human hand and their relationship to side, position, and asymmetry. homo, 62 (2), 126-143. gaskin c.m., kahn s.l., bertozzi j.c., bunch p.m. (2011) skeletal development of the hand and wrist. a radiographic atlas and digital bone age companion. oxford-new york: oxford university press, pp. 131. gilsans v., ratib o. (2012) hand bone age. a digital atlas of skeletal maturity, second edition, berlinheidelberg: springer, pp. 96. groenen m., groenen m.c., ceballos del moral j.m., gonzalez echegaray j. (2012) bilan de sept années de recherches dans la grotte ornée d’el castillo (cantabrie, espagne). in clottes j. (ed.), l’art pléistocène dans le monde / pleistocene art of the world / arte pleistoceno en el mundo, actes du congrès ifrao, tarascon-sur-ariège, septembre 2010, symposium «art pléistocène en europe». n° spécial de préhistoire, art et sociétés, bulletin de la société préhistorique ariègepyrénées, 65-66, 2010-2011, cd, 145-163. guthrie d.r. (2005) the nature of paleolithic art. chicago and london: the university of chicago press, pp. 507. janssens p.a. (1957) medical views on prehistoric representations of human hands. medical history, 1(4), 318-322. jones l.a., lederman s.j. (2006) human hand function. oxford: oxford university press, pp. 270. lockley m., roberts g., kim j.y. (2008) in the footprints of our ancestors: an overview of the hominid track record. ichnos, 15, 106-125. lockley m.g., mccrea r.t., buckley l.g. (2015) a review of dinosaur track occurrences from the morrison formation in the type area around dinosaur ridge. palaeogeography, palaeoclimatology, palaeoecology, 433, 10-19. lorenzo c., arsuaga j.l., carretero j.m. (1999) hand and foot remains from the gran dolina early pleistocene site (sierra de atapuerca, spain). journal of human evolution, 37 (3-4), 501-522. lorenzo c., pablos a., carretero j.m., huguet r., valverdú j., martinón-torres m., arsuaga j.l., carbonell e., bermúdez de castro j.m. (2015) early pleistocene human hand phalanx from the sima del elefante (te) cave site in sierra de atapuerca (spain). journal of human evolution, 78, 114-121. mallison h., wings o. (2014) photogrammetry in paleontology a practical guide. journal of paleontological techniques, 12, 1-31. marzke m.w., marzke r.f. (2000) evolution of the human hand: approaches to acquiring, analysing and interpreting the anatomical evidence. journal of anatomy, 197, 121-140. marzke m.w., shackley m.s. (1986) hominid hand use in the pliocene and pleistocene: evidence from experimental archaeology and comparative morphology, journal of human evolution, 15 (6), 439460. doi: 10.1016/s0047-2484(86)80027-6. mchenry h. (1992) body size and proportions in early hominids. american journal of physical anthropology, 87 (4), 407-431. doi: 10.1002/ajpa.1330870404 meyer m.c., aldenderfer m.s., wang z., hoffmann d.l., dahl j.a., degering d., haas w.r., schlütz f. (2017) permanent human occupation of the central tibetan plateau in the early holocene. science, 355, 64-67 + supplementary materials. mietto p., avanzini m., rolandi g. (2003) human footprints in pleistocene volcanic ash. nature, 422, 133. navsa n. (2010) skeletal morphology of the human hand as applied in forensic anthropology. university of pretoria, thesis submitted in fulfillment of the requirements for the degree phd anatomy in the faculty of health sciences, university of pretoria, pretoria. https://repository.up.ac.za/handle/2263/28575. ortega a.i. (2009) tras las huellas de ojo guareña. pyrenaica, 235, 364-367. panarello a. (2016) elementi di paleoicnologia degli ominidi. armando caramanica editore, marina di minturno, 228 p. panarello a., santello l., farinaro g., bennett m.r., mietto p. (2017a) walking along the oldest human fossil pathway (roccamonfina volcano, central italy)? journal of archaeological science: reports, 13, 476-490. 46 panarello a. et al. panarello a., palombo m.r., biddittu i., mietto p. (2017b) fifteen years along the "devil's trails": new data and perspectives. alpine and mediterranean quaternary, 30 (2), 137-154. rembado g., vicino g. (1985) descrizione della grotta e delle sue manifestazioni. rivista di studi liguri, 51 (4), 321-337. rodríguez asensio j.a., noval fonseca m.a. (2012) cueva tempranas (posada, llanes, asturias). in arias cabal p., corchón rodríguez m.s., menéndez fernández m., rodríguez asensio j.a. (eds.), el paleolítico superior cantábrico, actas de la primeras mesa rotonda, san román de candamo (asturias), 26-28 de abril de 2007. santander: publican, ediciones de la universidad de cantabria, 255-264. santello l. (2010) analysis of a trampled formation: the brown leucitic tuff (roccamonfina volcano, southern italy). ph.d. thesis in "scienze della terra", università degli studi di padova, dipartimento di geoscienze, (2010), tutor: p. mietto, cotutor: h.u. schmincke, and quoted bibliography. ht tp : / /paduaresearch.cab.unipd. i t /2566/1/ phd_thesis_lisa_santello.pdf. scaillet s., vita-scaillet g., guillou h. (2008) oldest human footprints dated by ar/ar. earth planetary science letters, 275 (3-4), 320-325. vallois h. (1927) étude des empreintes de pieds humains du tuc d’audobert, de cabrerets et de ganties. institut international d’anthropologie, ii session, ii int. anth. arch. prehist., (amsterdam), 328335. vergara m., agost m.j., gracia-ibáñez v. (2017) dorsal and palmar aspect dimensions of hand anthropometry for designing hand tools and protections. human factors and ergonomics in manifacturing & service industries, 28 (1), 2018, 17-28. doi: 10.1002/hfm.20714. webb s. (2007) further research of the willandra lakes fossil footprint site, southeastern australia. journal of human evolution, 52 (6), 711-715 zhang d.d., li s.h. (2002) optical dating of tibetan human handand footprints: an implication for the palaeoenvironment of the last glaciation of the tibetan plateau. geophysical research letters, 29 (5), 1072, 16.1-16.3. 47 the oldest human handprint ms. received: june 17, 2018 final text received: september 8, 2018 48 microsoft word 00_indice_06lm.docx   il quaternario it issn 039-3356 italian journal of quaternary sciences 24 (2), 2011 153-169 lower pleistocene deposits in east part of the favignana island, sicily, italy andrzej ślączka1, fabrizio nigro2, pietro renda3 & rocco favara2 1 inst. of geological sciences, jagiellonian university, kraków, poland 2 istituto nazionale di geofisica e vulcanologia, sez. di palermo, palermo 3 dip. geologia e geodesia, università di palermo, palermo corresponding author: p. renda <pietro.renda@unipa.it> abstract: ślączka a. et al., lower pleistocene deposits in east part of the favignana island, sicily, italy. in the favignana island (egadi archipelago, sicily, central mediterranean) pleistocene shallow water marine deposits are widely well exposed to form a prograding beach/near foreshore complex system. a group of facies associations have been recognised, suggesting different depositional environments and processes, related both to currents dynamics, palaeoclimatic conditions, sea-level changes and syn-sedimentary tectonics. the sedimentological pattern of the facies allow to reconstruct the depositional history of the island, characterised by the interplay of long/oblique shore currents dynamics and storm events during the lower pleistocene, developed on a mobile mesozoic bedrock just affected by strike-slip tectonics riassunto: ślączka a. et al., i depositi del pleistocene inferiore nel settore orientale dell’isola di favignana, sicilia, italia. nell’isola di favignana (arcipelago delle egadi, sicilia occidentale), affiorano estesamente calcareniti infrapleistoceniche, ben esposte soprattutto lungo le pareti delle numerose cave a pozzo, oggi dismesse, presenti nel settore orientale dell’isola. le calcareniti sono caratterizzate da un complesso sistema di associazioni di facies, che nel loro complesso indicano ambienti deposizionali di spiaggia/mare basso, e ricoprono in discordanza successioni carbonatiche mesozoiche deformate, che costituiscono le unità tettoniche esterne della catena siciliana, messe in posto nel miocene superiore depositi, di età pleistocenica inferiore, affiorano estesamente sia nel settore orientale che in quello occidentale dell’isola e sono separati da una dorsale carbonatica mesozoica, affiorante nel settore centrale. le migliori esposizioni di questi depositi si rinvengono nel settore orientale, dove sono state riconosciute cinque associazioni di facies. l’analisi sedimentologica ha permesso di ricostruire gli ambienti ed i processi sedimentari, che sembrano essere il risultato dell’interazione sia di dinamiche di correnti, di condizioni paleoclimatiche e di oscillazioni eustatiche, oltre che di deformazioni tettoniche sin-sedimentarie. le geometrie stratali, le strutture sedimentarie e le ichnofacies hanno permesso di distinguere nel settore orientale di favignana associazioni di facies caratteristiche di ambienti di spiaggia sommersa nei quali si è sviluppato un sistema di barre disposte obliquamente rispetto alla paleolinea di riva. la diffusa presenza di strutture erosive e di depositi canalizzati suggerisce che la deposizione sia avvenuta per lo più al di sopra del livello di base delle onde e che a luoghi sia anche stata condizionata da eventi di tempesta. l’evoluzione verticale delle facies mostra inoltre che la sedimentazione è stata anche controllata sia da oscillazioni del livello del mare che da mobilità del substrato, soggetto a deformazioni tettoniche, come evidenziato da numerose faglie di crescita presenti a diverse scale entro i depositi calcarenitici. keywords: depositional processes, sinsedimentary tectonics, pleistocene, egadi-sicily. parole chiave: processi deposizionali, tettonica sin sedimentaria, pleistocene, isole egadi, sicilia. 1. introduction the lower pleistocene (calabrian; malatesta, 1955) sediments exposed along some cliffs and in the quarries in the eastern sector of the favignana island (fig. 1), between favignana town and punta marsala, are a good example of ancient shoreface deposits (abate et al., 1999): the main purpose of this study is to describe them for try to define their depositional environments. the sediments of the favignana basin show general similarity to the upper pliocene-lower pleistocene calcarenite di gravina formation outcropping in apulia region, whose paleographical and sedimentological features were discussed in several papers (e.g. d’alessandro & bromley, 1986; d’alessandro et al.,1993; d’alessandro & massari, 1997; iannone & pieri, 1979; massari & chiocci, 2006; mateu-vicens et al., 2008; pomar & tropeano, 2001). the deposition of favignana pleistocene sediments was strongly influenced by the size and shape of the island. the paleofavignana island probably was smaller than presently. the clastic sediments forming calcarentes mainly derive from redeposition of ancient shore material and from very common skeletal remains of bentic organisms (fig. 2); a negligible part of clastics derive from the mesozoic calcareous rocks. the main controlling factor of the coastal sedimentation was the interplay of fair weather and storm periods, as already point out for similar lower pleistocene deposits, (massari & parea, 1988, mateu-vicens et al., 2008), also by prossible tsunamis (tinti, 1993). relative changes of sea level caused by local tectonic movements ślączka a. et al. 154 during lower pleistocene (abate et al., 1995) and by regional sea level fluctuations (tropeano & sabato, 2000) have an important role for the favignana area. 2. geological setting the favignana island belongs to the egadi archipelago (fig. 1) that represents an emerged part of the egadi thrust belt (abate et al., 1995-1997) of sicilianmaghrebian system (sulli, 2000; nigro & renda, 2001). favignana is mainly build-up of mesozoic-lower tertiary carbonate deposits, unconformably capped by younger sediments which are represented by biocalcarenites and biorudites of early-middle miocene and marly shales of late miocene (catalano et al., 1996; abate et al., 1997). mesozoiclower tertiary carbonate deposits are unconformably covered by middle-upper pliocene bluish marls and shale followed by lower pleistocene calcareous deposits and by tyrrhenian calcarenites and biorudites. the lower pleistocene depo sits are widespread along the eastern slope of the emerged paleo-favignana island in a pullapart basin, probably generated by transtensional faults activity. three faults systems, recognised in the favignana island, displace both the mesozoic-tertiary and pleistocene deposits (fig. 3). the first system, represented by n-s strike-slip faults, bounds the ridge of favignana and somewhere it reactives/displaces the miocene thrusts (abate et al., 1995). the other faults systems nesw and nnw-sse oriented at low-angle pitches. minor positive flower structures 1-to-10 meters in scale have also been observed (incandela, 1995; 1996; abate et al., 1995). in the eastern sector of the island, joints and minor strike-slip faults deform the deposits of pleistocene age, as well as the more younger breccias and paleosoils with displacements ranging from 0.1 to 1 m. this faulting activity determined smallscale block tilting, as recognised at cala monaci. in the middle-southern sector of the island a n-s oriented morphostructure (so-called promontorio scindo passo), is located and bounded by two strike-slip faults. the outcropping pleistocene deposits are displaced by minor right-hand transtensional and normal faults oriented nnw-sse. this grid of minor faults determined pull-apart like geometries in the north-western sector of the island (punta sottile) outcrop conglomerates and sandstones of pleistocene age, that are displaced by strike-slip and normal faults oriented from nw-se to w-e. the sandstones also fill the faults-related joints, suggesting soft-sediment deformation processes. also, between the localities of cala del pozzo and punta di ferro, outcrop gravels and sandstones of pleistocene age are deformad by nw-se and w-e oriented strike-slip faults (incandela, 1996; abate et al., 1995; 1997). in the northern sector of the island (punta faraglione), right-hand strike-slip faults oriented from nw-se to w-e, formed a set of meters-in-scale graben-like structures, filled by marine deposits of pleistocene age. this deposits are deformed by left-hand strike-slip faults ne-sw striking. finally, the pleistocene sandstones outcropping in the eastern sector of the island are folded to form a gentle anticline, interpreted as a drag-fold by incandela (1996) and abate et al., (1995). fig. 1. a) schematic structural map of the western sicily; b) schematic geological map of the favignana; c) pleistocene facies distribution in the eastern favignana island. a) carta strutturale schematica della sicilia occidentale; b) carta geologica schematica dell’isola di favignana; c) distribuzione delle facies pleistoceniche nel settore orientale dell'isola di favignana. lower pleistocene deposits in east part of the favignana ... 155 3. description of lithofacies several facies associations can be locally described on the basis of coexistence of lithological features, sedimentological structures and trace fossil assemblages. relationship between the facies associations are in some cases of hard interpretation because of lacking of several diagnostic elements: all the stratigraphic sections are incomplete, the basal lower pleistocene deposits are frequently unexposed and the erosion and/or faulting cut the topmost part of the successions. 3.1 facies association a this association, whose visible thickness is about 10 meters, is exposed in the western margin of the favignana basin between cala fumere and tonnara florio (north of the town of favignana, fig. 1c). it is generally represented by coarsening up sequence of calcarenites and conglomerates (fig. 4). the bottom of the sequence is masked by strike-slip fault. in the lower part, fine-to-coarse grained calcarenites, up to several dozen cm thick, display a variety of laminations, from parallel to cross-bedded in lunate megaripples and to wave ripple lamination1. in the upper part of the sequence, whose thickness can reach 1.5 meters, predominate conglomerates (fig. 4c) composed of rounded and subrounded pebbles derived from the erosion of the mesozoic bedrock, as well as from other lower pleistocene deposits. the size of sporadic boulders can reach dozen cm. scattered fragments of bivalve shells, rhodolithes and serpulite limestones also occur. the matrix consists in abraded bioclastics. conglomerates show crude parallel-bedding (pettijhon, potter & siever, 1987) and low angle cross bedding seaward directed; somewhere they are massive, without distinct internal structures. parallel-bedded conglomerates include small lenses of cross-laminated calcarenites. inclination of lamination is generally parallel or oblique to the coastline. conglomerate bodies present an erosional basal surface signed by broad shallow channels. trace fossils, random distributed in the sediments, must be referred to three ichnogenera, thalassinoides, planolithes and thenidium; somewhere vertical traces of skolithos-like also occur (fig. 4c). few beds of calcarenites are pervasive bioturbated (fig. 4d), locally limestone with borings can be observed in blocks up to tens cm in diameter. 1 locally there are bi-directional set of lenses (fig. 4a) and in places wave ripples follow upward megaripples. on some inclined laminae there are lags of gravels and shells (fig. 4b). also, between laminated bodies there are lags of flat limestone pebbles and thin (up to dozen cm) layers and/or lenses of conglomerates, formed by rounded pebbles of mesozoic limestones, bioclasts and fragments of molluscs and echinoids shells (fig. 4b). some layers (up to 50 cm thick) display distinct gradation from matrix supported carbonate pebbles and fragment of shells in lower part to coarse and medium grained calcarenites topwards. fig. 2. a) bioclastic sandstone with red algal clast, foraminifera and sporadic bryozoan. punta burrone. length of bar is 2 mm; b) bioclastic sandstone with foraminifera, bivalve shell fragments, bryozoan, red algae. punta fanfalo. length of bar is 2mm; c) fine grained bioclastic sandstone with numerous foraminifera. area of frascia. length of bar is 1 mm; d) bioclastic sandstone with red algae, bivalve shell fragments, bryozoan and foraminifera. madonna-cortigliolo. length of bar is 2 mm. a) arenaria bioclastica con clasti di alghe rosse, foraminiferi e sporadici briozoi. punta burrone. la lunghezza della barra è 2 mm; b) arenaria bioclastica con foraminiferi, frammenti di gusci di bivalvi, briozoi ed alghe rosse. punta fanfalo. la lunghezza della barra è 2 mm; c) arenaria bioclastica fine con numerosi foraminiferi. località frascia. la lunghezza della barra è 1 mm; d) arenaria bioclastica con alghe rosse, frammenti di gusci di bivalvi, briozoi e foraminiferi. madonna-cortigliolo. la lunghezza della barra è 2 mm. fig. 3 schematic structural map of the favignana island showing the main faults that deform the pleistocene deposits carta strutturale schematica dell'isola di favignana che mostra le principali faglie che deformano i depositi del pleistocene. ślączka a. et al. 156 fig. 4 facies association a (beach/nearshore zone), area of cala fumere, north from the town of favignana. a) lower part of the sequences started with bi-directional bundled cross-bedded lenses covered by thin layer of conglomerate built up of fragments of moluscs and echinoidea shells and unidirectional cross bedded calcarenites. length of penknife is 11 cm; b) cross-bedded calcarenites with lags of limestone pebbles along inclined laminae and covered by parallel laminated calcarenites with pebbly lags. length of penknife is 11 cm; c) layer of conglomerate showing crude gradation with well rounded limestone pebbles. sporadic vertical burrows (b). length of penknife is 11 cm; d) pervasive bioturbated calcarenites. in lower part of the picture burrowed limestone boulder (l) with borings. length of penknife is 11 cm associazione di facies a (zona beach/nearshore), area di cala fumere, a nord della città di favignana. a) la base della sequenza inizia con lenti a stratificazione incrociata a festoni bidirezionali ricoperte da un sottile strato conglomeratico costituito da frammenti di molluschi ed echinidi e calcareniti a stratificazione incrociata unidirezionale. la lunghezza del temperino è 11 cm; b) calcarenite a stratificazione incrociata con isolati ciottoli carbonatici disposti lungo lamine inclinate e ricoperti da calcareniti a laminazione piano-parallela con clasti isolati. la lunghezza del temperino è 11 cm; c) orizzonte conglomeratico scarsamente gradato, con ciottoli di calcare ben arrotondati. sporadici burrows verticali (b). la lunghezza del temperino è 11 cm; d) calcareniti ampiamente bioturbate. nella parte inferiore della foto si osserva un ciottolo carbonatico (l) perforato. la lunghezza del temperino è 11 cm. predominance of coarse-grained sediments and sedimentary structures suggest that facies association a (fig. 1c) represents high wave energy beach/upper foreshore zone (pomar & tropeano, 2001; clifton, 2006; bridge & demicco, 2008). in this zone storm sediments, represented by pebbly lags, passing upwards to finer laminated deposits, graded beds, lunate megaripples and pebbly layers, are interrupted by fair weather conditions when developed wave ripple lamination and burrowed interval (clifton, 1976; johnson & baldwin, 1986). seaward deeping cross-bedding prevailed. occasionally longshore southward currents appeared. observed intricately interwoven cross-lamination are characteristic of wave origin and connected probably with fair-weather period. very thick conglomerates near the top of sequence can mark exceptional strong storms events. due to storms cyclicity, deposits of previous periods were partly eroded and are only partially preserved. increase of conglomerates in the upper part of the sequence is linked to the increase of storm magnitude in lapse of time. periodically pervasive bioturbated horizons took place. 3.2 facies association b facies association b, whose thickness not exceeds 10 meters, is located between punta lunga and lido burrone, southwards of favignana town (fig. 1c) and reaches favignana harbour towards the north. it is characterized by the occurrence of calcirudites with several algae remains and rhodolithes and occurrence of horizons with thalassinoides. relationships to the previous facies association is not clear in the souther part (cala monaci) due to the lack of exposures. however data from the harbour of favignana imply that facies association b is generally situated farther to east than the previous one. relationship with older substratum is unknown. the outcrop of this association starts near punta lunga with thick bedded/massive conglomerates (fig. 5a) built-up mainly by rhodolithes, up to dozen cm in size, fragments of serpulite and, somewhere, by fragments of bivalve shells. erosive surfaces bound lower pleistocene deposits in east part of the favignana ... 157 base of some conglomerates, displaying broad but general shallow (several tens of cm) channels. crude planar cross-bedding is visible in topmost part of the section. in the western sector the conglomerates can reach 3 meters thick. there are lenses, up to 1.5 meters thick, composed by calcarenites rich in mollusc shells that display in their lower part crude lamination, that becomes more chaotic upwards (fig. 5b). the upper part of the sequence consists of thick-bedded conglomerates, displaying erosive base with planar westward cross-bedding, locally underlined by lag of single, ellipsoidal pebbles. decreasing of size of clastics is visible (fig. 5c) landwards. in some localities, homogenous medium-grained calcarenites, up to several tens cm thick, enriched in pelitic material, show a medium bedding. the sequence generally stops with coarsening-up strata, homogenous in their lower part, showing lowangled lamination near the top, covered by laminated bioturbated calcirudites (fig. 5d) with eastward dipping and muddy drapes. somewhere channelized conglomeratic beds with pebbles, rhodolihts and shell fragments, in which the size of clastics and thickness of layers is decreasing eastward, can be observed. conglomerates show a cover of oblique cross-bedded layers, generally dipping toward ese, pervasively bioturbated and topped or by a bundled part (fig. 5e) and by horizontal laminated or wave laminated calcarenites. calcirudites with rhodoliths crop out eastward, almost up to lido burone locally. broad and deeply incised erosional channels, nw-se and n-s directed, filled up by stack of oblique and locally sinuosinoidal cross laminated material with very coarse grained material concentrated in the middle part of inclined layer (fig. 5f), can be observed. thin, pelitic horizons separate individual laminated set. the calcirudites in punta lunga are locally cut by scolithostype traces (fig. 5d) and on the upper surface there is characteristic network of thalassinoides (fig. 5g) and sporadic ophiomorpha (fig. 5h). this can represent cruziana and skolithos ichnofacies (bromley, 1996; seilacher, 1967) or thalassinoides skolitus suite of d’alessandro et al. (1993). facies association b, mainly deposited by storm waves of high magnitudes, could represent a portion of the upper shoreface zone (elliot, 1986; clifton, 2006). size of detrital material and seeward inclination of cross-bedding show that coarse detrital material, together with rhodoliths and serpulids, was probably derived from shoreline, by back currents generated by exceptionally strong storms. bodies of sediments rich in fragments of bivalve shells chaotically distributed represent storm deposits. single coarse-grained body was probably formed during a very short time amount (about few hours?). erosive channels, perpendicular or oblique to the shoreline, probably created by local rip currents can also be seen. visible in exposures bodies and structures probably not represent all events which took place in this area as due to the strong erosion processes, which are suggested by preserved sedimentary structures, erosional surfaces specially, part of sediments was reworked by subsequent storms. gravel containing dunes, generated by strong storm current migrated generally seawards, but sporadic occurrence of landward inclined cross-bedding implies occasionally shore-ward movements of dunes. longshore currents played less important role than currents more and less perpendicular to the shoreline. sediments of fair weather, represented by medium scale cross bedding, are preserved only locally. the lack of trace fossils in the lower part of sequence could be en efect of conditions existing during that period (strong current and wave actions), which was probably unfavorable for development and/or preservation of epiand infauna (d’alessandro & bromley 1996). only at the end of the development of facies association b sequence, locally, in sheltered area, were formed favourable, calm habitats that allowed to develop and preserve extensive nets of thalassoinoides and skolithos. the coexistence of skolithos and thalassoinoides indicates moderate turbulence d’alessandro, loiacono & bromley (1993). mcilroy (2004) sugessts that it can be an effect of partially isolation of that area by bars. 3.3 facies association c, coarser fraction this facies association, that stretches eastward (seaward) from the previous one facies in the area of lido burrone up to punta fanfalo2 (fig. 1c), is dominated by coarse and medium-grained calcarenites, whose thickness not exceed 20 meters. generally the coarser fraction consists in shell fragments and the sediments typically present traces of echinoidea. direct relation to the facies association b is partly obliterated by faults (abate et al., 1995). the visible part of the sequence starts with a layer of calcirudite with rhodolithes and shell fragments, similar to those of facies association b, covered by thin calcarenite strata with trough cross laminations or ripple cross-lamination. inclination of cross-bedding structures is generally southwestwards and less common towards s-sse (punta burrone, western outcrop) and wsw (punta fanfalo, eastern outcrop). the main part of facies association c is characterized by occurrence of thick beds (up to two m) of thick-bedded calcarenites, often sub-horizontal laminated, mostly well-sorted, coarse to medium-grained with channels filled up by cross-bedded calcarenites (fig. 6a). there are also thick (up to 1 m) tabular crossstratified calcarenites, covered by ripple cross-laminated ones. locally, shallow (up to tens of centimeters deep) channels broad occur, filled-up by crosslaminated calcarenites (fig. 6a). several beds contain numerous dispersed shells of pectinids and echinoidea (see the upper part of fig. 6b) and, less commonly, of brachiopods, dentalium and cardium. molluscs in life position or forming layers of convex-up oriented bivalve shells (fig. 6c), together with fragments of echinoidea and – more rarely – rhodoliths, heve been observed in some oucrops (lido burrone, punta fanfalo). these organic remains may form lags above erosional lower surfaces (fig. 6d). in punta burrone area planar bifurcated structure, similar to mangrove tye roots (fig. 10h) have been discovered. this generally low-energy facies association, locally with mollusc shells in life position, was developed in relatively deep, quiet environment within shoreface zone. longshore currents from nne dominate, favouring 2 sediments similar to facies association c are also exposed in area of punta marsala. ślączka a. et al. 158 fig. 5 facies association b (uppershore zone), area di punta longa, south of town of favignana. a) conglomerate build up mainly of rhodolithes, cross-bedded in upper part. north towards the right. length of measure 1 m; b) local, concentration of shells of molluscs horizontally arranged. in lower part visible cross-bedding. length of penknife is 6 cm; c) massive calcarenite with poorly defined crosslamination covered by cross-bedded calcirudites, which pass landward into coarsegrained calcarenites. sharp bedding plane records storm period. note a fault on the right side of picture (f). length of measure 1 m; d) sub-horizontal, coarsening upwards calcirudites with pebbly lags and erosional upper surface overlain by seaward dipping coarse-grained and conglomeratic calcarenites strongly bioturbated. note vertical, scolithos type traces fossils. some of them penetrated the lower unit. less visible are thalassinoides developed on surface of the inclined layers – compare fig. 3g. pen for scale; e) sequence which started with calcirudites that contain rhodolithes and fragments of shell, covered by horizontal layers (f), passing upwards into oblique cross-bedded bioturbated calcarenite (cr) and topped by hummocky like (b) calcarenite. seaward inclination of laminae. length of pencil is 15 cm; f) a local channel (ch) in sub-horizontal coarse calcarenites with muddy matrix. this channel, 1,5 meters deep, is filled by stack of sinusoidal cross-bedded bodies incline landward. note patchy concentration of pebbles (e.g. near hammer). hammer for scale; g) thalassinoides network at the top of the sequence shown on fig.3d. note the thin layers of mudstone that are very rare in the study area; h) detail of thalassinoides network; i) ophiomorpha occur only sporadically. lower pleistocene deposits in east part of the favignana ... 159 the deposition of thin, tabular cross-stratified or horizontally laminated calcarenites. exceptionally, storm action reworked the sediments developing both massive calcarenites, with lags above erosive surfaces, or calcarenites with vertical sequence of tabular crossstratified and ripple laminations or erosive channels filled up by cross-bedded calcarenites. during colonization windows (goldring, 1991), planar trace fossils sets (cruziana facies) took place. facies association c represents low energy environment connected with a bar trough (clifton, 2006). sporadic appearance of very coarse sediments could be rather an effect of strong storms (elliot, 1986; clifton, 2006) while evolution of beach/nearshore facies could be linked with change of sea level (mateu-vicens, 2008). scattered occurrence of problematic mangrove type roots suggests shoal areas. 3.4 facies association d this facies association, characterized by the occurrence of tabular laminated cross-bedded calcarenites (figs 7, 9a), whose lower and upper surface of beds are erosive, with broad deep channels (figs 8, 10b) and abundant trace fossil of skolithos ichnofacies, is exposed, for a thickness that do not exceed 15 meters, along the northern island shore (frascia area), between the town of favignana and cala s. nicola (fig. 1c).the main facies, mainly developed in western (landward) part of association d (fig. 9a), is represented by thick bedded (up to 2 m) and coarse-grained calcarenites, with subhorizontal and large-scale cross-bedding. generally the lamination is emphasized by change of grain size and locally by lags of fragments of bivalve shells. locally laminae are pervasive bioturbated. the main feature of some cross-bedded strata shows a laminated-tobioturbated pattern, similar to described from pleistocene deposits of salento area by d’alessandro & massari, (1977). in few cases, only the lower part of each set of inclined laminae is bioturbated; somewhere bioturbation is pervasive. in some thick calcarenite beds, a vertical facies succession can be observed: from the base subhorizontal laminated calcarenites crop out, capped by cross-bedded calcarenites, locally wedgelike, whose top consists of strongly bioturbated calcarenites (fig. 10)3. generally, cross-bedding is inclined towards se, only locally toward w. the upper part of the facies association d shows typically the occurrence, particularly in more distal (seaward) part (fig. 9b), of broad (dozen or so meters) erosional channels and washouts (usually up to 2 m) (fig. 8): channels are filled-up or by massive calcirudites (fig. 10a) or by calcarenites with trough cross-lamination, partly destroyed by bioturbation. some calcarenites show crude concave or chaotic laminations and can pass into parallel laminated and cross-bedded calcarenites. exceptional deep channels (up to 5 m) have been observed in cala calamoni, se from the town of favignana; channels are filled by laminated calcarenites and massive calcarenites with scattered bivalve shells. direction of channels are generally n-s, (nw-se to ne-sw) and locally w-e4. facies association d is also characterized by the occurrence of scolithos ichnofacies (figs 10c-e, 11a), in some localities the scolithos-type traces cross the earlier bioturbated zones (fig. 10e); less common there are cruziana (thalassinoides and ophiomorpha) ichnofacies linked with the colonization windows. concentration of vertical burrows at the top of the bed is often observed (fig. 10d). mainly between punta s. nicola and madonna traces of echinoidea have been observed. in the central part of the island, near the town of favignana, in very thick cross-bedded and subhorizontal laminated calcarenites, several horizons with scolithos are observed (fig. 11a). locally, there are cluster burrows represented by straight radial tubes (few millimeters thick) and tens of cm long (fig. 10g), which resemble that traces which were made by colony of social insects (curran, 1992). the planar, radial and bifurcated structures (fig. 10h) can represent root system of plants. the presence of rooted plants in the pleistocene sediments 3 less common are thick-bedded calcarenites, with big scale through cross-bedding, locally, there are sets of bi-directional cross bedded bodies, lenses of mediumand fine-grained structurless calcarenites and intercalations of calcirudite represented generally by matrixsupported conglomerates with rhodoliths (few cm in size), fragment of shells (mainly bivalves, locally dentalium) and sporadic pebbles of mesozoic limestones. sporadically shells of bivalves (fig. 10a) and echinoidea are concentrated on surfaces of cross-bedding. 4 in some places, near the top of the beds, convolute laminations or single small conical forms are visible, the dimension of convolute raises several tens of cm (fig. 10b). locally, there are sets of small, rotated synsedimentary normal faults (fig. 11b). in few places small parallel dunes, 30 cm of width, which upper surface can be covered by scattered shells and rhodolithes, are locally developed on the upper surface of calcarenites. associazione di facies b (zona uppershore), area di punta longa, a sud della città di favignana. a) conglomerato costituito principalmente da rodoliti, a stratificazione incrociata nella sua parte superiore. il nord è verso destra. l’unità di misura è di 1 m; b) particolare, concentrazione di gusci di molluschi disposti orizzontalmente. nella parte inferiore è visibile la stratificazione incrociata. la lunghezza del temperino è 6 cm; c) calcarenite massiva con stratificazione incrociata mal definita ricoperta da calciruditi a stratificazione incrociata che passa verso terra a calcareniti grossolane. le superfici di strato registrano eventi di tempesta. si noti una faglia sul lato destro della foto (f). l’unità di misura è 1 m; d) calciruditi suborizzontali, a gradazione inversa con clasti maggiori isolati, troncati da una superficie di erosione sulla quale poggiano calcareniti grossolane e conglomerati, inclinati verso mare, fortemente bioturbati. si notino le tracce fossili verticali tipo scolithos. alcune di queste attraversano l'unità più bassa. meno visibili sono i thalassinoides sviluppati sulle superfici di strato inclinate – confronta la fig. 3g. vedi la penna per la scala; e) sequenza sedimentaria che inizia con calciruditi contenenti rodoliti e frammenti di gusci, seguiti da strati orizzontali (f), passanti verso l'alto a calcareniti a stratificazione obliqua, incrociata, bioturbate (cr) e ricoperte da calcareniti tipo hummocky (b). l’inclinazione delle lamine è verso il mare. la lunghezza della matita è 15 cm; f) canale locale (ch) nelle calcareniti suborizzontali grossolane con matrice pelitica. questo canale, profondo 1,5 metri, è riempito da un gruppo di corpi sinusoidali a stratificazione incrociata inclinati verso terra. nota la concentrazione di ciottoli (e.g. vicino il martello). vedi il martello per la scala; g) griglia di thalassinoides al tetto della sequenza mostrata in fig. 3d. nota gli strati sottili di peliti che sono molto rari nell'area di studio; h) dettaglio della griglia di thalassinoides; i) a luoghi vi è anche la presenza sporadica di ophiomorpha. ślączka a. et al. 160 fig. 6 facies association c (shoreface zone), area east of lido burrone. a) coarse grained, subhorizontal laminated calcarenite, partly eroded. cross-bedding of calcarenite that fills eroded part is inclined towards sw (height of wall around 2 m); b) horizontally laminated calcarenites with layers and patches of shells of moluscs in concave-upward position. note their imbrications. length of tape measure is 100 cm; c) horizontally laminated calcarenites covered by horizon of imbricated fragments of echinoidea shells and massive calcarenites with scattered fragments of shells. pencil for scale; d) upper surface of calcarenite covered by network of traces of echinoidea. length of tape-measure 100 cm; e) small, longshore channel (ch), 45 cm deep incised in medium bedded calcarenites that are crossbedded in the lower part and horizontally laminated in the upper part. length of note-book is 16 cm. associazione di facies c (zona di shoreface), settore orientale di lido burrone. a) calcarenite grossolana, a laminazione suborizzontale, parzialmente erosa. la calcarenite a stratificazione incrociata che riempie i settori erosi è inclinata verso so (l’altezza della parete è circa 2 m); b) calcareniti a laminazione orizzontale con livelli di frammenti di gusci di molluschi con la concavità rivolta verso l'alto. si noti la loro imbricazione. la lunghezza del nastro è 100 cm; c) calcareniti a laminazione orizzontale ricoperte da orizzonti costituiti da frammenti embricati di gusci di echinoidi e calcareniti massive contenenti frammenti sparsi di gusci. vedi la matita per la scala; d) superficie sommitale delle calcareniti coperta da una griglia di tracce di echinoidi. la lunghezza del nastro è 100 cm; e) piccolo canale parallelo alla linea di riva (ch), profondo 45 cm che incide gli strati calcarenitici caratterizzati da stratificazione incrociata nella porzione inferiore dell’affioramento e da laminazione orizzontale in quella superiore. la lunghezza del libretto è 16 cm. lower pleistocene deposits in east part of the favignana ... 161 fig. 7 facies association d. vertical facies succession started with subhorizontal laminated calcarenite with erosional top surface that is followed by wedge-like, seawards cross-bedded body and terminated by pervasive bioturbated part (colonization window). probably an effect of one storm. next succession starts with subhorizontal laminated calcarenite. frascia, east from town of favignana. associazione di facies d. successione verticale di facies: in basso calcareniti a laminazione suborizzontale troncate al tetto da una superficie erosiva. segue un corpo, con geometria cuneiforme, a stratificazione incrociata inclinata verso mare, ampiamente bioturbato nella parte terminale (colonizzazione a ”finestra”), probabilmente per effetto di tempesta. la rimanente parte della successione inizia con calcareniti a laminazione suborizzontale. località frascia, ad est dell’abitato di favignana. fig. 8 facies association d. stack of several successive channels filled or by cross-laminated calcarenites or by, massive calcirudites with dispersed pebbles. note that erosion removed practically all-preceding sediments. it clearly illustrates sediments of several exceptionally highenergy events. frascia, east from town of favignana. associazione di facies d. sequenza verticale di diversi canali riempiti o da calcareniti a laminazione incrociata o da calciruditi massive con ciottoli sparsi. nota che l’erosione ha praticamente rimosso tutti i sedimenti precedentemente deposti. ciò mostra chiaramente che si tratta di eventi deposizionali ad energia molto elevata. località frascia, est dell’abitato di favignana. fig. 9 facies association d (shoreface zone), a) large scale cross-bedded calcarenites and calcirudites dipping seaward. note the seaward decrease on angle of cross-beds (pointed by arrow). sparse sub-vertical burrows occur. area of frascia, near to town of favignana, exposure along the shoreline; b) laminated calcarenites inclined towards ese cut by two channels, one a broad filled by laminated coarse grained calcarenites (ch) and other younger, deeper, with steep wall filed up by massive debrite (d) that represent sediments of cohesive flow. direction of channels is generally w-e. note several vertical burrows of scolithos type (s). the uppermost part is strongly bioturbated (b). wall is 4 meters high. more distal of shoreline exposure then on fig. a. associazione di facies d (zona di shoreface), a) calcareniti e calciruditi, con stratificazione incrociata a grande scala, immergenti verso mare. da notare che l’inclinazione degli strati decresce verso mare (punta della freccia). a luoghi si rinvengono anche burrows subverticali. affioramento lungo la costa nell’area di frascia, vicino l’abitato di favignana; b) calcareniti laminate immergenti verso ese, incise da due canali, il più grande dei quali è riempito da calcareniti grossolane laminate (ch) mentre l’altro più recente e più profondo, è riempito da detrito massivo (d) che rappresenta il prodotto di un flusso sedimentario coesivo. la direzione dei canali è generalmente o-e. da notare anche la presenza di numerosi burrows verticali di tipo scolithos (s). la porzione più elevata della sezione è fortemente bioturbata (b). la parete è alta 4 metri. l’affioramento è più distante dalla costa rispetto alla fig. 9a. ślączka a. et al. 162 fig. 10 facies association d (shoreface zone) a) calcirudite with scattered molluscs shells. note increase of on angle of crossbedding toward left (landward). storm triggered sediments. penknife is 6 cm long; b) bending of laminated calcarenites due probably to synsedimentary folding connected with vertical movement of substratum. wall aprox. two meters high; c) set of vertical burrows of scolithos type that cut massive calcirudite. rucksack for scale; d) scolithos ichnogulid. note two sets of vertical trace fossils: older formed below upper erosional surface (colonization window) in calcarenite and younger in calcirudite that locally penetrated the lower calcarenite. length of tape measure 100 cm; e) totally bioturbated level cut by younger vertical burrows (vb). length of tape measure 100 cm; f) detail of a branched vertical burrow in calcarenite. penknife is 6 cm. long; g) bundle of vertical tubes that resemble a colony of insects. length of tape measure 50cm; h) structure on upper surface of calcarenite that resemble root traces, probably mangrove type of plant. pencil for scale. associazione di facies d (zona di shoreface) a) calcirudite con gusci di molluschi sparsi. si noti l’aumento dell’angolo di inclinazione verso sinistra (verso terra). deposito di tempesta. il temperino è lungo 6 cm; b) calcareniti con geometria curviforme dovute a piegamenti sinsedimentari connessi con le deformazioni verticali del substrato. la parete è alta circa 2 m; c) set di burrows verticali del tipo scolithos dentro la calcirudite massiva. per la scala vedi lo zaino; d) ichnofacies di scolithos. si notino i due set di tracce fossili verticali: il più antico si è formato nella calcarenite sotto la superficie erosiva superiore (finestra di colonizzazione) il più giovane, invece, dentro la calcirudite e localmente ha penetrato le calcareniti. la lunghezza del nastro è 100 cm; e) livello completamente bioturbato attraversato da burrows verticali più recenti (vb). la lunghezza del nastro è 100 cm; f) dettaglio di un burrow verticale e ramificato dentro la calcarenite. il temperino è lungo 6 cm.; g) fascio di burrows verticali che assomigliano ad una colonia di insetti. la lunghezza del nastro è 50 cm; h) struttura sulla superficie superiore delle calcareniti che assomiglia a una traccia di radice, probabilmente tipo mangrovia. vedi la matita per la scala. lower pleistocene deposits in east part of the favignana ... 163 were already noted by d’alessandro et al,. (1993) in the bradano trough (south apennines). in several places, calcarenites beds are cut by faults, some of which become extinct upwards within the sandbodies. depositional assemblages of sedimentary structures, existence of coarse lag of shell debris, lateral changes of facies, frequent channels, disorganized shell debrites sequences, similar to hummocky sequences of dott & bourgeois (1982), are characteristic for high-energy shoreface environment (clifton, 2006; elliot, 1986; wysocka, 2002). planar laminated sets reflect highest current velocities and covering them cross-bedded lenses the decreasing of energy conditions (cfr. clifton, 1976). the thick bedded, large-scale cross-beds of calcarenite and calcirudite, that developed in western part, near the town of favignana, with bioturbated intervals (cruziana ichnofacies), can represents remnants of shoreface zone with seaward prograding wedges (pomar & tropeano, 2001; mateu-vicens et al., 2008). more seaward part, with differentiated facies, relatively abundant washouts and channels and common skolithos ichnofacies probably represents inner bars system (bridge & demicco, 2008; clifton, 2006; davdson-arnott & greenwood, 1976). the prevailing ichnofacies, represented by skolithos ichnofacies, in this area represents more shallow conditions than cruziana ichnofacies (seilacher, 1967, pemberton et al., 1992). also, big-scale planar cross-bedded bodies, observed east of the town of favignana, with tiers of scolithos ichnofacies, can represent a local inner bar system generated by longshore currents. washouts and channels that cut the inner shoreface longshore bars were created by rip currents, generated from long shore ones (clifton, 1976-2006; davdsonarnott & greenwood, 1976). the channels size increased with magnitude of storm. occurrence of stacks of storm surge channels, cut through calcarenite beds and filled commonly by storm sedimentary breccias (storm lag deposit), are indicative of periods of frequent storms occurrence. very deep erosional channels, with sedimentary breccia that derived from the shoreline and transported seaward on distance almost 2 km, could be related to surges and debris flows (clark & pickering, 1996), generated by very high energy events (hurricanes and probably also tsunami tinti, 1993). the latter could be the effect of submarine earthquakes, generated by local tectonic movements that existed during late pleistocene. vertical changes of bioturbation characters (pervasive bioturbation and skolithos type) can represent water depths changes, generated by synsedi fig. 11. continued facies association d. a) vertical stacking of subhorizontal and low-angle laminated calcarenites with abundant vertical burrows (s) and pervasive bioturbated horizons (b). penknife (white) is 6 cm long. cala calamoni, abandoned quarry on west outskirts of the town of favignana town; b) sequence of parallel laminated coarse grained calcarenites that rest on the flat symmetrical dune (d) around 30 cm high. note normal synsedimentary fault system at the top of the lower layer. penknife (black) is 6 cm long. another part of the same quarry as on fig.7a. continua associazione di facies d. a) sequenza verticale di calcareniti con laminazioni suborizzontali ed a basso-angolo, con abbondanti burrows verticali (s) ed orizzonti ampiamente bioturbati (b). il temperino è lungo 6 cm. cala calamoni, cave abbandonate alla periferia ovest della città di favignana; b) sequenza di calcareniti grossolane a laminazione parallela, espressione di parte di una duna simmetrica e piatta (d) alta circa 30 cm. da notare la presenza di un sistema di faglie dirette sinsedimentarie normali al tetto dello strato più profondo. il temperino è lungo 6 cm. altro settore della cava di fig. 7a. fig. 12 facies association e. a) vertical stacking of several horizontal and crosslaminated calcarenites that continue over a length of tens of meters, separated by subhorizontal surfaces represented probably temporary wave base levels. note a huge channel on the left side of the picture, deep more than 10 meters, it is filled up by massive calcirudites. slope lithofacies. cliff below cala torretta, nw from calarossa; b) detail of fig. 12a. note a vertical stacking of double sandbodies that are represented by horizontal and cross-laminated calcarenites. cross-lamination dipping to se (seaward), ch = channel. associazione di facies e. a) successione verticale di calcareniti a stratificazione orizzontale e a laminazione incrociata continua per decine di metri, separata da superfici suborizzontali che probabilmente rappresentano temporanei livelli di base delle onde. da notare un canale di notevoli dimensioni sul lato sinistro della figura, profondo più di 10 metri, riempito da calciruditi massive. litofacies di scarpata. cala torretta, a no di calarossa; b) dettaglio di fig. 12a. si noti la successione verticale dei corpi sabbiosi costituiti da calcareniti a stratificazione orizzontale e a laminazione incrociata, inclinata verso se (mare), ch = canale. ślączka a. et al. 164 fig. 13 facies association e (lower shoreface zone with bar system). area between torretta and bue marino. a) lower part of the association e. sequence started by fine-grained calcarenites (fc) followed by subhorizontal laminated calcarenites (h and set of bidirectional cross-bedded calcarenites covered by horizontal layers coarse grained calcarenites partly pervasive bioturbated (b). cross lamination is inclined to s and nw. that sequence show resembles to facies association c. punta marsala; b) lower part of facies association e. sequence started with parallel laminated calcarenites (l) overlaid by cross-bedded zone (t) that have oblique to sigmoidal stratification facing sw (shoreward), and terminated by set of medium scale trough cross-bedding (b) resembling hummocky crossbedding, with bioturbated horizons. note flat dunes. probably crest or landward slope part of an outer bar. cliff in calarossa; c) detail of fig. 12a that show internal architecture of cross-bedded facies. note the diminishing inclination of cross-lamination on lee side of dunes (white arrow); d) sequence of medium to large-scale bi-directional tabular cross-bedding calcarenite bodies. bue marino; e) synsedimen lower pleistocene deposits in east part of the favignana ... 165 mentary tectonic activity, as well as by sea level changes. they were also responsible for temporary appearance of very shallow environments, that are suggested by occurrence of traces of mangrove type root system and sub-aerial dunes with cluster burrows, which are regarded as insects burrows (curran, 1992). development of synsedimentary faults, escape of water structures was also triggered by tectonic activity, as suggested by synsedimentary, meters-in-scale, folds and convolutions (lowe, 19751976). however, some of them, that developed within gently inclined foreset crosslamination, could be also generated by local slumps (łaptas, 1992). the general lack of sediments with structures that represent fair-weather conditions (finegrained sediments, oscillation small-scale cross bedding) may be an effect of bottom erosion during successive storm (clifton, 1976). a more outer part of facies association d, observed near capo s. nicola, where traces of echinoidea appear, can represents a local phenomenon or more deeper part of shoreface. it shows similarity to facies association c. direction of inclination of cross laminations within facies association d document that calcareous sand was transported generally southeastwards, obliquely to the shoreline. seaward transport was less common. landward sand transport from reworked more distal bars is now visible only locally. 3.5 facies association e the lowermost part of this facies association, whose contact with the underlying facies association d is sharp, starts or with a layer (tens of cm thick) of broken shells, covered by cross-bedded calcirudites seaward dipping (cala canaleddi), or with a thick, homogenous bed of calcarenite covered by a tabular cross bedded interval that close with a pervasive bioturbated layer (calarossa).the thick sequence of large-scale cross-bedded and subhorizontal laminated bedforms are the most characteristic feature of this association (fig. 12), outcropping in the easternmost part of the favignana island, between the localities of cavallo and bue marino; the facies thickness reaches more than tary conical structures (a) of different size probably created by escape of water. bioturbated horizon (b) pinching out towards one of these structures. at the top of subhorizontal there is a sequence of bi-directional foresets. torretta, calarossa; f) uppermost part of the bar sequence, parallel laminated in the lower part and large scale crossbedded in the upper part. inclination of foresets is seaward. note bioturbated horizon (b) in the lower part of the photograph. cala fossofelle. associazione di facies e (shoreface suddivisa da un sistema di barre). area tra torretta e bue marino: a) porzione più profonda dell'associazione e. inizia con calcareniti molto fini (fc) seguite da calcareniti a laminazione suborizzontale (h) e da un set di calcareniti a stratificazione incrociata bi-direzionale ricoperto da strati orizzontali di calcareniti grossolane, a luoghi bioturbate in maniera pervasiva (b). la laminazione obliqua è inclinata verso s e no. la sequenza è simile all'associazione di facies c. punta marsala: b) parte più profonda dell'associazione di facies e. inizia con calcareniti a laminazione parallela (l) ricoperte da un intervallo a stratificazione incrociata (t) che possiede una stratificazione da obliqua a sigmoidale verso so (mare), e termina con un gruppo di corpi a stratificazione incrociata (b) simili a stratificazioni gibbose (hummocky), con orizzonti di bioturbazione. si noti la presenza di dune piatte. probabilmente la cresta o il lato interno costituivano parte di una barra esterna. scogliera di calarossa; c) dettaglio di fg. 12a che mostra l’architettura interna della facies a stratificazione incrociata. si noti che l'inclinazione della stratificazione incrociata diminuisce sul lato di protezione delle dune (freccia bianca); d) sequenza di corpi calcarenitici tabulari a stratificazione incrociata bi-direzionale a media-grande scala. bue marino; e) strutture coniche sinsedimentarie (a) di diversa taglia, probabilmente effetto di fughe d’acqua verso l’alto per improvviso carico sedimentario. orizzonte bioturbato (b) che si rastrema verso una di queste strutture. al tetto del corpo sub-orizzontale vi è una sequenza di foresets bidirezionali. torretta, calarossa; f) parte più elevata della sequenza di barra, laminazione parallela nella parte più bassa e stratificazione incrociata a grande scala nella parte superiore. l’inclinazione dei foresets è verso mare. si noti l’orizzonte di bioturbato (b) nella parte più bassa della fotografia. cala fossofelle. fig. 14 top of a bar with medium-sized dunes at the top (d, arrows) with foreset inclination oblique to paleo-shore line. lower part of facies association e. calarossa. top di una barra seguita da dune di medie dimensioni (d, frecce) con inclinazione dei foreset obliqua rispetto alla paleolinea di riva. parte più bassa dell'associazione di facies e. calarossa. fig. 15 stack of erosional channels (1-4) filled by laminated calcarenites. arrow indicates slumped block (sl) of a normal synsedimentary fold. note that sedimentary structures in slumped block are only partly disintegrated. current directions generally perpendicular to the face of photograph. facies association e. punta s. vituzzo. pila di canali erosivi (1-4) riempiti da calcareniti laminate. la freccia indica un blocco scivolato (sl) di una piega sinsedimentaria. si noti che le strutture sedimentarie nel blocco scivolato sono disintegrate solamente in parte. le direzioni delle correnti sono generalmente perpendicolari alla fotografia. associazione di facies e. punta s. vituzzo (cala rossa). ślączka a. et al.   166 fig. 16 higher part of the lower pleistocene sequence started with large cross-bedded calcarenites that dipping to nw (landward) covered by calcarenite with low angle seaward dipping lamination and by set of cross-bedded calcarenites with at least two orders of bounding surfaces. upper surface of this set is erosional and covered by thick sand body with subhorizontal lamination that terminated by ripple laminated calcarenites (r). note that bioturbation in cross-bedded calcarenite, on the right side of the picture, marked by letter b, disappears to the left, in more elevated part. facies association e, upper part of a bar system. cala fossofelle, case di vita. parte più elevata della sequenza del pleistocene inferiore che inizia con calcareniti, a stratificazione incrociata a grande scala immergenti verso no (verso terra), ricoperte da calcareniti laminate debolmente immergenti verso mare e da un gruppo di strati di calcareniti a stratificazione incrociata. la superficie superiore di questo gruppo di strati è erosiva ed è ricoperta da uno spesso corpo sabbioso con laminazione suborizzontale che termina con calcareniti laminate con strutture da ripple (r). si noti che la bioturbazione nelle calcareniti a stratificazione incrociata, sul lato destro della figura marcato dalla lettera b, scompare verso sinistra nella parte più elevata. associazione di facies e, parte superiore di un sistema di barra. cala fossofelle, case di vita. 40 meters in cavallo-torretta area. this facies in calarossa and cala canalleddi area rest directly on the uplifted lower pliocene marls (abate et al., 1995-1997) or sediments similar to facies association c5. the main part of this facies is built of thickand very thick-bedded sequences of, coarse-grained calcarenites, with subhorizontal and/or low angled lamination, and of calcarenites with large-scale cross-bedding (figs 12, 13b,f). calcarenites with hummocky cross-lamination (fig. 13b, uppermost part) also occur. seawardand landward-directed, as well as shore-parallel, sets of cross bedding are observed (fig. 13 b, d, and e)6. the majority of calcarenite beds presents lower and upper sharp, erosional surfaces. however, locally higher horizontal laminated bedform rest on non-eroded rippled upper surface of the lower bed. calcarenite beds form bodies long some of tens of meters, each gradually wedging out; lateral changes of facies have been observed. locally, asymmetric, cross-bedded mega-ripples (few tens centimeters high and several meters long) are preserved (fig. 14). also, symmetrical sandwaves (up to 50 cm high and several meters of length), built-up of homogenous sand have been observed on the top of horizontal laminated calcarenites. in more western (landward) part (torretta area), visible fragment of facies association sequence two, almost flat, erosional surfaces divide into three parts (fig. 12a) each calcarenitic body. each part shows complex internal structures; particularly the middle one consist in subhorizontal stack and in cross-bedded sandbodies (fig. 12b). this organization is preserved on distance of tens of meters, with local landwards opposite direction of cross-bedding. at calarossa and bue marino localities, the outer part of calcarenite body is characterized by cross-bedding dipping both landwards (fig. 13b, c), as well seaward (figs 13b-f, 14 and 16). somewhere, single or sets of medium-sized conical or diapiric structures can be observed at the top of horizontal laminated body (fig. 13e). crossand horizontal-bedded calcarenites are cut by several channels, generally filled up by crosslaminated bodies (fig. 13e); locally, stacks of channels are visible (fig. 15). a small synsedimentary slump was formed along the wall of channel (fig. 15). in topmost part of the sequence there broad channels filled by cross stratified bodies have benn observed (left part of fig. 13f and fig. 16), locally the filling shows lags of pebbles and rhodolithes or of debrites at the bottom, graded in their lower portion and containing scattered rhodolithes and shell fragments. along the western boundary of cavallo locality exceptionally large and deep channels were developed: one of them, more than 10 meters deep, is infilled by homogenous calcarenites (fluxoturbidite type; ślaczka & thompson, 1981); another one, tens of meters broad and more than 15 meters deep, is visible along the northern cliff of the same locality (fig 12a). intercalation of layers of pervasively bioturbated calcarenites (from dozen centimeters to one meter thick) occurs locally (fig. 13a, b, and f). a typical feature of some cross-bedded bodies consists in laminated-to-bioturbated pattern, similar to those described by d’alessandro & massari, (1997): normal and bioturbated laminae are alternate (fig. 13c). in some cases, only a lower part of inclined laminae shows bioturbations (figs. 13e and 16). sporadically, traces of echinoidea occur in the lower part of the sequence. scolithos-type of burrows is extremely rare and occurs in higher part of the sequence. bioturbation disappear in the highest part of the sequence (torretta). coarse-grained and conglomeratic sandbodies, occurring in the lowest part of facies association, more than two kilometers from the ancient shoreline, probably represent storm-reworked beds, redeposited from the shoreline and distributed on the shallow shelf, east from paleo-favignana island, by high energy currents. the main part of facies association e consists of mixed facies of thick and very thick bedded, planar or crosslaminated, sandbodies, showing often characteristic fa cies succession from planar and/or crossbedded to hummocky-like and/or medium trough cross-lamination, bounded by unconformity with local channels represents the outer part of shoreface zone, marked by offshore bars/ridges system related to storm high-energy epi 5 in punta marsala where facies association e is underlayed by facies association c the profile starts with trough cross-bedded finegrained calcarenite, horizontally laminated, fine-grained muddy calcarenites (fig 13a), with traces of echinoidea, covered by layer (up to 50 cm thick) built-up of shell fragments covered by several meters calcarenite, generally pervasive bioturbated. 6 locally, in elongated lens-like bodies, laminae are sinusoidal, and cross-bedded sandbodies form tabular cossets. the ripple crosslaminated bodies (up to 1.5 m thick) locally rest on tabular cross-stratified or horizontal laminated sandbodies. lower pleistocene deposits in east part of the favignana ... 167 sodes (bridge & demicco, 2008; clifton, 2006; elliot, 1986; johnson & baldwin, 1986). long lasted, wind-induced currents deposited thick, seaward-dipping crossbedded calcarenites, spreading out on distance of hundreds meters. a submarine bar system, probably developed along an uplifted block of the pre-pleistocene platform and run generally from north towards south. stacks of bedforms with subhorizontal lamination and through cross-bedding dipping seaward and landward, with decrease of bioturbation and occurrence of erosional channels, can be regarded as crest part of bar facies, similar to suggestion of davidson-arnott & greenwood (1971). seaward slops of bars are probably represented by a sequence, where number of bioturbated bedforms and sets of small scale trough increase in number and where generally the planar bedding dips seawards. this successions are exposed in bue marino area, in the easternmost part of the favignana island. occurrence of layers, with offshore and onshore dipping sets of cross-bedding, shows on periodical migration of dunes seaand shoreward by wave induced currents, but seaward movements predominated. the magnitude and direction of all of these currents was varying during weather and long-term sea-level changes, and was also connected with vertical tectonic movements. it can be suggested that the observed bedforms were generated by giant long periods waves and by related surges, such as those generated by propagation of hurricanes and/or tsunamis into shallow water areas (d’alessandro & massari, 1997; tinti, 1993). periods of high wave energy were interrupted by fair weather periods, during these latter wave cross-ripple beds develop and the sea bottom was colonized by burrow animals of cruziana ichnofacies while the upper part of deposited bedforms was intensively bioturbated. the occurrence of bioturbation suggests favorable conditions only in lower part of foreset laminae thus suggesting the persistence of a sea depth useful for a better concentration of food. on the contrary the uppermost part of sequence, totally devoid of trace fossils, can represents facies of short duration aeolian dune. considerable thickness of facies association (over … m), the lacking of distinct changes of facies in vertical profile and of distinct progradation suggest a fault-induced lowering of this part of offshore area. flat erosional surfaces near cavallo area show similarities to shoreface erosion planes described by elliot (1986): temporary tectonic uplift could be create an effect of sea-level changes of a part of the shelf, thus increasing the erosion by wave actions: it removed clastic material from higher part of the uplifted bar toward deeper sea. 4. conclusions the distribution of bedforms, sedimentary structures and ichnofacies allow to distinguish eastwards from shoreline of paleo-favignana island several characteristic facies associations connected with foreshore/shoreface (f a a), upper shoreface (f a b), upper/middle shoreface (f a d) and lower shoreface (f a e) depositional zones with a system of inner bars (f a d p.p.) and outer bars (f a e p.p.) parallel or oblique to the shoreline separated by trough (f a c) (fig. 17-18). widely distribution washouts, rip channels and sediments of tractional currents in all facies associations suggest deposition above wave-base level. temporary developed partly emerged dunes have been recognized. only negligible part of clastic material was derived from erosion of uplifted part of paleo-favignana island that probably had greater northward extension, however bulk of the bioclastic material accumulated on favignana inner shelf originated from shoreline material and is composed of debris from molluscs, calcareous red algae, bryozoan, foraminifera, etc. the main role in distribution of clastics was played by storms that induced strong and very strong longshore currents along the shoreline: these currents were shunted offshore and cut and filled channels across the bars. landward movement of clastic fig. 17 a model of currents distribution and facies associations, east from paleofavignana island. prevailed southward longshore currents. scale bar dimension is approximate. vertical scale is roughly estimated. modello della distribuzione di correnti e delle associazioni di facies ricostruite per il settore orientale della paleo-isola di favignana, caratterizzata dalla prevalenza di correnti dirette verso sud parallele alla riva. le scale, orizzontale e verticale, sono approssimative. fig. 18 schematic profile of facies distribution in shoreface zone east from favignana island with two bar systems. profilo schematico della distribuzione delle facies di spiaggia nel settore orientale dell’isola di favignana, con evidenziati i due sistemi di barra. ślączka a. et al. 168 material and the development of megarippled dunes has been observed locally, due to high energy landwards waves. during tsunami-related high-energy events scattered large erosional structures were probably formed. similar events triggered local debris flows. storm-generated sedimentation units are underlined by the erosion surfaces on which some channels, up to tens meter wide and several meters deep took place. besides storm wind-induced currents were active producing longshore and rip currents that deposited seaward dipping crossbedded calcarenites which spread out on distance of hundreds of meters. the storm periods were separated by fair weather intervals: cross-ripple beds were colonized by population of burrowing organisms thus producing pervasive bioturbation. the bioturbated deposits were frequently eroded by series of storms. during intense storm the erosion cut deeper part of dunes and episodic, low angle dipping surfaces;. the development of such erosional surfaces was also controlled by uplifting of the substratum and by relative change of the sea level. synsedimentary strike-slip tectonics were besides reported for favignana area. the relevant thickness of the facies association e, more than 40 meters, also suggests a generalized fault-induced downward movements of the substratum7. typical vertical and lateral sequences of sedimentary structures in storm deposits were represented by subhorizontal lamination succeeded by about-planar cross-bedding, hummocky type cross stratification or/and rarely wave ripple lamination. the top of sequence is often bioturbated, as an effect of recolonization by fauna during fair weather. the recognized facies associations also differ in ichnofacies content: in fa a ichnofossils are rare and mainly represented by short vertical tubes; in fa b wide areas are colonized by thalassinoides and, more rarely, by vertical burrows (cruziana and skolithos ichnofacies); in fa c traces produced by echinoidea; in fa d skolithos ichnofacies and horizons pervasively bioturbated are common, locally cluster of insects burrows have been oberved; in fa e trace fossils are rare and are limited to few traces of echinoidea and some vertical burrows, while pervasive bioturbated horizons are common. the recognized facies associations also differ in ichnofacies content: in fa a ichnofossils are rare and mainly represented by short vertical tubes; in fa b wide areas are colonized by thalassinoides and, more rarely, by vertical burrows (cruziana and skolithos ichnofacies); in fa c traces produced by echinoidea; in fa d skolithos ichnofacies and horizons pervasively bioturbated are common, locally cluster of insects burrows have been oberved; in fa e trace fossils are rare and are limited to few traces of echinoidea and some vertical burrows, while pervasive bioturbated horizons are common. references abate b., incandela a. & renda p. (1997) carta geologica delle isole di favignana e levanzo dipartimento di geologia e geodesia, univ. palermo. abate b., ferruzza g., incandela a & renda p. (1995) tettonica trascorrente nelle isole egadi sicilia occidentale studi geologici camerti, vol. spec. 2, 9-14. abate b., incandela a. & renda p. & slascka a. (1999) -shoreface deposits and ichnofacies, favignana, sicily. in: clemmensen l. b. (ed) abs. vol. 19th regional european meeting of sedimentology, copenhagen 24-26 august, 1999, 2. bridge j. & demicco r. (2008) earth surface processes, landforms and sediment depositscambridge university press. pp. 815. bromley r.g. (1996) trace fossils chapman & hall, london: pp. 361. catalano r., di stefano p. sulli a. & vitale f.p. (1966) paleogeography and structure of the central medi-teranean: sicily and its offshore area tectonophysics 260, 291-323. clark j.d. & pickering, k.t. (1996) submarine channels, processes & architecture vallis press, london, pp. 231. clifton h.e. (1976) wave-formed sedimentary structures: a conceptual model in: davis jr., r.a. & ethington r. l. (ed.) beach and nearshore deposits. society of economic paleontologists and mineralogists, spec. pub. 24, 126-148. clifton h.e. (2006) a reexamination of facies models for clastic shorelines sepm spec. pubbl., 84, 293-337. curran h.a. (1992) trace fossils in quaternary, bahamian-style carbonate environments: the modern to fossil transition in c.g. maples & r.r. west (eds.), trace fossils. short courses in paleontology, the paleontological society, knoxville, 5, 105-120 d’alessandro a. & bromley r.g. (1986) trace fossils in pleistocene sandy deposits from gravina area, southern italy rivista di paleontologia e stratigrafia 92, 67-91. d’alessandro a., loiacono f. & bromley r.g. (1993) marine and nonmarine trace fossils and plant roots in regressional setting (pleistocene, italy) riv. ital. paleont. strat., 98, 495-522. davidson-arnott r.g.d. & greenwood b. (1976) facies relationships on a barred coast, kouchibouguac, new brunswick, canada in: davis jr., r.a. & ethington r. l. (ed.) beach and nearshore deposits. society of economic paleontologists and mineralogists, spec. pub. 24, 149-168. dott r.h. & bourgeois j. (1982) hummocky stratification: significance of its variable bedding sequences bull. geol. soc. of amer., 93, 663-680. elliot t. (1986) siliciclastic shorelines in: h.g. reading (ed.) sedimentary environments and facies, blackwell scientic publications, 155-188. fox w.t. & davis jr. r., a. (1976) weather patterns and costal processes in: davis jr., r.a. & ethington r.l. (ed.) beach and nearshore deposits. society of economic paleontologists and mineralogists, spec. pub. 24, 1-23. goldring r. (1991) fossils in the field longman, harlow. incandela a. (1995) lineamenti stratigrafico-strutturali dell’estremità nord-occidentale della sicilia e delle 7 also locally observed sharp differences in thickness and facies between facies associations could be fault-induced, as proposed for similar phenomena in upper cretaceous shelf sandstones in sudetes by wojewoda (1986). lower pleistocene deposits in east part of the favignana ... 169 isole di favignana e levanzo (arcipelago delle egadi) tesi di dottorato. palermo incandela a. (1996) deformazioni neogeniche nelle isole di favignana e levanzo (isole egadi) mem. soc. geol. it., 51, 129-135. johnson m.e. (2002) paleoislands in the stream: paleogeography and expected circulation patterns geobios, 35, 457-476. johnson m.e.& baldwin c.t. (1986) shallow siliciclastic seas in: h.g. reading (ed) sedimentary environ ments and facies, blackwell scientic publications, 229-282. lowe d.r. (1975) water escape structures in coarsegrained sediments sedimentology, 22, 157-204. lowe d.r. (1976) subaqueous liquefied and fluidised sediment flows and their deposits sedimentology, 23, 285-308. łaptas a. (1992) giant-scale cross-bedded miocene biocalcarenites in the northern margin of the carpathian foredeep ann. soc. geol. poloniae, 62, 149-167. raaf j.f.m., de boersma j. r. & gelder a.v. (1977) wave generated structures and sequences from a shallow marine succession. lower carboniferous. county cork. ireland sedimentology, 4, 1-52. mcilroy d. (2004) some ichnological concepts, methodologies, applications and frontiers in: mcilroy, d. (ed.) the application of ichnology to paleoenvironmental and stratygraphic analysis. geological society, spec. pubbl., 228, 3-27. seilacher a. (1967) bathymetry of trace fossils marine geology 5, 413-428. malatesta a. (1955) risultati preliminari del rilevamento in sicilia e nelle isole egadi boll. serv. geol. it., 76, 517-521. massari f. & chiocci f. (2006) biocalcarenite and mixed-cool water prograding bodies of the mediteranean pliocene and pleistocene: architecture, deposirional setting and forcing factors geological society, london, special publications 255, 95120. massari f. & parea g.c. (1988) progradational gravel beach sequences in a moderate to high-energy, microtidal marine environment sedimentology, 35, 881-913 mateu-vicens g., pomar l. & tropeano m. (2008) architectural complexity of a carbonate transgresive systems tract induced by basement physiography sedimentology, 55, 1815-1848. nigro f. & renda p. (2001) late miocene-quaternary stratigraphic record in the sicilian belt (central mediterranean): tectonics versus eustasy boll. soc. geol. it., 120, 151-164. pemberton s.g., mac earchern j.a. & frey r.w. (1992) trace fossil facies models environmental and allostratigraphic significance in: walker, r.g. / james n.p. (eds) facies models response to sea level change, geological association of canada: 47-72. pettijohn f.j., pottr p.e. & siever r. (1987) sand and sandstone springer-verlag. pp. 553. pomar l. & tropeano m. (2001) the calcarenite di gravina formation in matera (southern italy): new isights for coarse grained, large-scale, cross-bedded bodies encased aapg bull., 85, 661-689. seilacher a. (1967) bathymetry of trace fossils marine geology, 5, 413-428. slascka a. & thompson s. (1981) a revision of the fluxoturbidite concept based on type examples in the polish carpathian flysch ann. soc.geol. poloniae, 51, 55-75. sulli a. (2000) structural framework and crustal characteristic of the sardinia channel alpine transect in the central mediterranean tectonophysics, 324, 321-336. tinti s. (1993) evaluation of tzunami hazard in calabria and eastern sicily, italy in. s. tinti (ed.) tsunamis in the world. kluwer, 141-157. tropeano m. & sabato l. (2000) response of pliopleistocene mixed bioclastic temperatewater carbonate systems to forced regression: the calcarenite di gravina formation. puglia se italy in: d. hunt & gawthorpe, r.l. (eds) sedimentary responses to forced regressions. geol. soc. of london, spec. pubbl., 172, 217-243. wojewoda j. (1986) fault-scarp induced shelf sand bodies: turonian of the intrasudetic basin in: eisseyre, a.k. (ed), ias 7th european regional meeting kraków-poland. excursion guiebook. may 1986, 31-52. wysocka a. (2002) clastic badenian deposits and sedimentary environments of the roztocze hills across the polish-ukrainian border acta geologica polonica, 52, 535-561. ms. ricevuto il 29 gennaio 2010 testo definitivo ricevuto il 25 marzo 2011 ms. received: january 29, 2010 final text received: march 25, 2010 amq short notes 26_2 zerboni divito monegato available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 25 (2), 2012, xvii xviii report on the alpine quaternary workshop (intimate & inqua-ceclap) obergurgl, austria, 3-7 october 2013 giovanni monegato1, karin a. koinig 2, christoph spötl 3, oliver heiri 4 1 cnristituto di geoscienze e georisorse, torino, italy 2 institute of geology, university of innsbruck, innsbruck, austria 3 institute of ecology, university of innsbruck, innsbruck, austria 4 institute of plant sciences and oeschger centre for climate change research, bern, swiss corresponding author: g. monegato <g.monegato@csg.to.cnr.it > abstract: we provide a short report on the alpine quaternary workshop, held tirol region (a). the discussion was aimed at illustrating suitable proxy records for correlations in the alpine region for the time window 8 to 60 ka. keywords: intimate, inqua, late pleistocene, alps. on 3-7 october 2013 the alpine quaternary workshop took place in obergurgl (a) in the central alps of tyrol and discussed climate change in the alpine region over the last 60,000 years. 32 scientists, postdocs and phd students from 7 different countries attended the workshop. this was a merger of two initiatives, intimate-cost (http://costes0907.geoenvi.org/), focusing on the discussion and compilation of climate proxy records from the greater alpine region for the time window 8 to 60 ka and to make them eventually available to the paleoclimate and modelling community in an easy-to-access database, and inquaceclap (circumalpine events and correlations during the late pleistocene), focusing on the correlation on late pleistocene records in the alps. fig. 1 workshop participants at the rotmoos type locality monegato g. et al. xviii two workshops held in 2012 preceded the obergurgl meeting: intimate working group 2 workshop “climate records in the austrian and swiss sectors of the alpine region”, which took place in bludenz (a), and the ceclap workshop “the lgm in the alps”, which took place in udine (i). the 2013 workshop encompassed proxy records from the entire alps and their forelands, and the goal was to draw from as many sources of paleo-information as possible. a large part of the meeting was therefore spent on presentations by all attendants in order to get to know each other’s research topics, which included lake sediments, cave deposits, fluvial and glacial systems as well as paleobiological and geoarcheological aspects. the discussion routinely expanded into the late evening with small groups sitting together and discussing data. during the final session two groups were formed, one focused on the time frame 18-8 ka, the other concentrating on the older period from ca. 60-18 ka. the aim was to identify key topics of paleoclimate research in the alps for the near future. which are the most urgent questions? which methodologies are needed to advance this research field? which archives are unrepresented? in addition to the plenary activities and presentation sessions, field trips were organized in order to promote onsite exchange of ideas on a range of topics concerning the last 60 ka of environmental change in the alps. a midconference fieldtrip, held on october 4, led to the rotmoos mire, the type locality of the mid-holocene rotmoos oscillations, recorded by the local vegetation history in the palustrine deposit. a first post-workshop excursion took place on october 7 at the baumkirchen pit, stratotype of the boundary between the middle and upper würmian in the alps (lead by christoph spötl, sam barrett and reinhard starnberger). this excursion provided fresh insights based on new drillings, their analysis and chronological data. this excursion had a late afternoon stop for an overview of slightly older paleolake and slope sediments in the unterangerberg region, about 50 km downstream in the inn valley. a following two-day field trip (led by jürgen reitner) examined field evidence, based partly on detailed geological maps, of the lgm glacier advance and late glacial oscillations in tributary valleys of the lower inn valley and discussed ice-flow reconstructions and valley overdeepening. in this field trip, the lower würmian successions of hopfgarten were also visited and discussed. the joint days both at obergurgl and in the field triggered intense discussion and fostered the exchange of new ideas and concepts. the participants agreed to continue and expand these activities and plans are to convene again in 2014 to focus on the western alpine region. fig. 2 the lacustrine succession of the baumkirchen clay pit (middle würmian, inn valley) was visited after the conference. ms. received: october 18, 2013 final text received: october 18, 2013 intimate & inqua-ceclap, 3-7 october 2013 xix available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 113 119 multiproxy-based reconstruction of the feeding habits from the late middle pleistocene straight-tusked elephant population of poggetti vecchi (southern tuscany, italy) chiara capalbo dipartimento di scienze della terra (dst), università di firenze, firenze, italy dipartimento di scienze della terra e del mare (distem), università di palermo, palermo, italy corresponding author: c. capalbo <chiaracapalbo@gmail.com> abstract: the palaeodietary preferences from the elephants of poggetti vecchi, which radiometrically dated around 171,000 years bp, have been investigated by cross-comparing the results obtained with low-magnification analysis of microwear (ldm), 2d-roughness parameters and surface geometry assessment, mesowear and stable isotope analysis. proboscideans tend to be opportunists, and this improves their ability to respond to climate impacts and environmental fluctuations. the dietary signal of the last meals suggests the consumption of a great amount of graminaee or other plants quite rich in phytoliths. conversely, mesowear data indicate more browsedominated, mixed dietary behaviour, which probably reflects seasonal variations, and environmental changes. keywords: palaeodietary, early middle pleistocene, palaeoenvironment, palaeoloxodon 1. introduction modern elephants are regarded as a particular kind of mixed-feeders with complex behaviour. depending on the availability of different kinds of plants, as well as on climatic conditions, they show most variable feeding habits. microwear patterns can therefore change considerably and rapidly both seasonally and geographically (grube et al., 2010). despite all the potential interpretative biases (which may derive from morpho-functional variations in the chewing apparatuses, the involvement of contaminants, post-mortem alterations, methodological inconsistencies, the use of inappropriate instruments and analyst's skill) conventional dental microwear analysis is a powerful tool and still preferable to other methodologies, first of all because it is the easiest way for functional morphologists to investigate and obtain relevant information from microwear patterns. moreover, it permits to analyse large numbers of samples at lower costs using basic equipment. however, a reliable quantification of the smallest scars may exceed the capacities of light microscopy, which would thus impose the use sem or other instruments capable of investigating three-dimensional surface texture. for the present study we adopted an alternative, multiproxy and comparative approach which is based on a combination of different methods. our results concern dietary signals of last meals, obtained with low-magnification analysis of microwear (ldm), and carbon and oxygen determination of enamel fraction, which reveals the dietary history of earlier phases of an individual's life. we also used the mesowear method, which reflects specifically the abundance of grasses that are present in the habitats where animals live and not just the openness of the landscape. the mesowear method was recently extended to proboscideans (saarinen et al., 2015). it records dietary signals over long time spans. left and right molars of each individual can show different mesowear angles (probably due to one-side chewing habits); changes also occur throughout the life of an individual, including seasonal shifts in dietary preferences (e.g., sukumar & ramesh, 1995; cerling et al., 2006, 2009; rivals et al., 2012). mesowear signals can therefore record seasonal variations in an elephant’s feeding habits. any surface can be described as a complex landscape with peculiar geometric form and textural alterations (waviness and roughness). surface textures that appear smooth at coarse scales can be demonstrably rough at sufficiently fine scales. worn enamel finds correspondence with industrially manufactured surfaces. all surface measuring systems reconstruct 3d surface models by assembling line profiles. however much more detailed information about the enamel wear is encapsulated in 2d-roughness parameters rather than 3d-models. hence the 2dsurface data and geometric pattern employed in this study can be used to characterize the physical topography of enamel facets, quantifying the universal attrition– abrasion equilibrium controlling dental wear and to classify individuals into feeding categories. the results of pooled analysis show that the use of different methods is a potentially more effective way to constructively address the many issues on the feeding adaptations of extinct elephants than is relying on only one method. the methodology used in this study reveals the wealth of information that a multiproxy approach can contribute in studies aimed at palaeodietary and palaeoenvironmental reconstructions. in addition, these results seem to agree with preliminary environment reconstruction based on both palaeobiological and taphonomic investigation, as well as with preliminary https://doi.org/10.26382/aiqua.2018.aiquaconference geoarchaeological insight. the poggetti vecchi area (42°49'8.92" n, 11° 4'19.41" e) is located in southern tuscany (central italy), some 7 km northwest of grosseto. an in-depth palaeoenvironmental reconstruction of the site of poggetti vecchi, obtained combining archaeo -palaeontological records and sedimentological data, can be found in benvenuti et al. (2017). 2. materials and methods fifteen upper and lower molars of both sides and of a fairly wide spectrum of ontogenetic ages were used to perform both microwear and mesowear analyses. a list of the selected molars, together with a summary description of them, is reported in tab. 1. in this study, the capital letters represent upper cheek teeth (e.g., m1), while lower case letters indicate lower teeth (e.g., m3). molds and casts were prepared by adapting the methods described by solounias & moelleken (1992a) and solounias & semprebon (2002). they were then examined under a zeiss standard light stereomicroscope at 40 and 100x magnification using a unidirectional external oblique light source with a shallow incidence angle. several microphotographs were taken at both magnifications; the latter gave the best-resolved images of the elephant teeth, providing a visual field of 2 mm2 (todd et al., 2007). qualitative and quantitative investigation of microwear scars was carried out directly on computer using the software imagej, focusing on functional plates. we performed the following actions: 1) calculated the total number and frequency of scratches and pits; 2) measured the average length and width of the scars; 3) used width/length ratios to discriminate fine from coarse scratches and small from large pits; 4) expressed microwear density as number of features per analysed area. we measured the carbon and oxygen isotope composition of the enamel of a second molar (n. 1365). a fraction of the enamel was mechanically cleared of dentine and cement using tungsten-carbide rotary tools and finally ground with an agate mortar. the purity and crystallinity of the fine enamel powder was monitored by xray diffraction analysis. a randomly oriented powdered sample was mounted on glass slides and scanned. the diffraction pattern was collected on a philips pw 1050/37 diffractometer using graphite-monochromatised cukα radiation, obtained at 40 kv and 20 ma. the sample was scanned from 5° to 60° with a step size of 0.02° 2θ and a counting time of 2s. following chenery et al. (2012), the sample was not subjected to leaching pre-treatment; about 150-200 mg of enamel powder was reacted with 100% orthophosphoric acid (h3po4) at 25°c for three days to produce co2, which was then collected by cryogenic separation. finally, the isotope compositions were measured by finnigan mat 252 mass spectrometer. the oxygen isotope value (δ18osc versus pdb-1) was obtained from the structural carbonate; using daux et al.’s (2008) equation it was directly translated into the isotope composition of the environmental water δ18ow versus smow). the mesowear angles were measured on detailed profiles obtained using a burton’s steel professional comb. the contour gauges were used to identify the dentine valleys; following saarinen et al.’s (2015) indication, the mesowear angle measurements were taken using a digital goniometer with 0.1 precision. the average angular values were estimated based on angle measures of the three central lamellae of each molar. the results were then compared with those reported by saarinen et al. (2015). finally, following the indications given by saarinen & lister (2016), the average mesowear angles were correlated with the percentages of the pollen of non-arboreal species (nap) and, in particular, of poaceae, to evaluate how much local vegetation is reflected by the inferred dietary habits. two representative specimens (the adult n. 5500 and the calf n. 98) have been selected for topographic assessment based on 2d-roughness parameters and geometric patterns. the casts were scanned by a digital microscope (hirox kh-7700). the auto multi focus tool enabled the creation of 3d images obtained by composing a set of fifteen planes taken at different focuses with a vertical step ranging from 4 to 8 µm (depending on the topographic features of the sample). on the samples surface, a rectangular area of about 450x600 µm was scanned at 0.381 µm resolution using a 500x objective; almost three rois (regions of interest) were selected at the center of the two central enamel loops of the teeth and scanned to inspect if and how the surface texture varies on each sample. the software mountainsmap7® image (digitalsurf, france) was used to obtain 2d images of the topography of the acquired areas. almost 10 roughness profiles along with iso 4287 (1997) standard parameters, were extracted from each image by applying a gaussian filters to clean the raw data. 2droughness parameters are extensively described in kaiser & brinkmann (2006). mountainsmap® also includes tools specifically designed to assess fractal dimension (a statistical index of complexity) and isotropy by processing digital maps. finally, 3d reconstructions were here obtained by the use of interactive 3d-surface plot plugin of imagej software, which creates interactive surface plots (i.e., dots, lines, mesh, filled, display colors, etc.) from all kinds of images. 114 capalbo c. tab. 1 description of the specimens used for microwear inspection, mesowear and surface texture assessment. 115 3. results the qualitative microwear analysis revealed that microwear patterns are similar all over the occlusal surface. microwear features are most variable on both the lingual and buccal sides of each functional plate, whereas pits and scratches are most variable on distal plates. qualitative and quantitative analyses and measures confirm that scratches (fine, mixed and coarse) outnumber pits on each of the teeth examined. furthermore, coarse features are usually more frequent at the centre of the enamel loops, whereas fine ones (which are usually longer, narrower and shallower) are mainly concentrated along their edges. cross-coarse scratches are particularly abundant in the middle section of molar teeth; also pits (either large, mixed, or small ones) can be abundant locally, especially on buccal and lingual sides. the microwear patterns observed in this analysis are summarized in fig. 1. xrd graph plot revealed the absence of impurity phases; the diffraction pattern shows a peak characteristic of apatite (fig. 2). its value is rather similar to that of the enamel phase of the teeth of modern and fossil elephants (ayliffe et al., 1994). the carbon isotopic value of the enamel structural carbonate (-11.05‰ δ13csc versus pdb-1) and the corresponding calculated palaeodiet (-25.14‰ δ13cdiet versus pdb-1) suggests that the straight-tusked elephant population of poggetti vecchi falls in the ‘‘c3-dominated diet’’ field. in tab. 2 are reported the oxygen isotope value or structural carbonate and the environmental water isotope calculations. the mean acute mesowear angles vary considerably in each specimen, ranging from 90.95° to 119.82°: in the population as whole, the angle measurements vary from 102.63° to 119.82°. the regression analysis that is shown in fig. 3, as well as the comparison of the mean mesowear angles with the relative graminae pollen frequencies (fig. 4) calculated at poggetti vecchi (m. mariotti lippi personal communication) indicate that our population had browse-dominated mixed diet with relatively flexible feeding behaviors. only a small subset of 2d-roughness parameters seems to characterize more efficiently the enamel texture and dietary categories, which are listed in tab. 3, where geometry calculations are also included. the fractal dimension (fig. 5) was found to be rather similar in both the poggetti vecchi specimens ranging from 2.59 and 2.74. the orientation of roughness features (isotropy/anisotropy texture), which is expressed as the tree main angular values and isotropy percentage, is shown in fig. 6. the latter are more heterogeneous in the specimen 5500, varying from 18.6 to 40.9%, whereas the average value in the specimen 98 is 31.50%. 3d-reconstructions of the enamel samples are shown in fig.7. men and elephants in prehistoric maremma fig. 1. % of pits vs % of scratches scatter diagrams at 100x magnification. a) average percentage of pits plotted against average percentage of scratches; b) average density of pits plotted against average density of scratches; c) average length of scratches plotted against the average width of scratches. fig. 2 xrd pattern of the dental enamel sample analyzed for this study. tab. 2 carbon and oxygen isotope enamel determination and palaeodiet calculation. 116 fig. 3 linear regressions of δ13c values from tooth enamel and mean mesowear angles. value obtained from the poggetti vecchi molar compared with data drawn from saarinen et al. (2015). the 95% confidence limits are shown as dashed lines (coefficient r2 = 0.92, student’s t-tests p < 0.001). fig. 4 regressions between mean mesowear angles and mean poaceae (grass) %. values obtained from poggetti vecchi molars compared with data drawn from saarinen and lister (2016). (coefficient r2 = 0,00133. student’s t-tests p = 0.001). tab. 3 a selection of 2d-roughness texture parameters and geometric patterns employed in this study and corresponding average values. fig. 5 example of fractal dimension analysis calculation for one the selected enamel rois studied for the molar n. 98 following the enclosing boxes method [with the slope and correlation coefficient (r2) of regression line]. fig. 6 polar diagrams showing texture direction and related parameters of the three selected enamel rois studied for the molar n. 98. fig. 7 example of 3d-surface models obtained by assembling roughness line profiles. capalbo c. 4. discussion and conclusion our results were compared with the average numbers of pits and scratches observed in modern and extinct taxa, as they are reported in the literature; the corresponding dietary morphospace are shown in fig. 8. the high percentage of mixed and fine scratches associated with abraded micro-areas observed on the teeth from poggetti vecchi indicates feeding on abrasive food, containing high amounts of opal phytoliths, but also the ingestion of soil particles picked up with grasses. our elephants cluster within the grazer dietary morphospace. differences between the various italian palaeoloxodonts may indicate different dietary preferences, as well as a high plasticity to adapt to local environmental and microclimatic conditions. modern elephants increase grass intake during more humid periods (sukumar & ramesh, 1995); if the poggetti vecchi elephants behaved similarly, the microwear pattern here obtained is indicative of grass consumption under rather cold and wet climatic conditions. we could determine the isotopic concentration of only a single sample, and hence the range of variability is not known. consequently, the results on the palaeodietary habits of these italian middle pleistocene straight -tusked elephants and on the palaeoenvironmental conditions under which they lived are essentially inferred based on comparisons with published data on straighttusked elephants from other sites, namely la polledrara and casal de’pazzi, in italy (palombo et al., 2005), and neumark nord 1, in germany (grube et al., 2010). the carbon isotope of the structural carbonate in the enamel fraction from poggetti vecchi reaches -11.05 ‰, and the corresponding calculated δ13c value of the diet thus is 25.14‰ and falls into the field of c3 plants. the overall δ13c values of the diet in comparative samples vary 117 fig. 8 bivariate plot of the average number of scratches versus the average number of pits and corresponding feeding morphospace envelopes (leaf browsing, fruit browsing, grazing, seasonal and meal by meal mixed-feeders taxa). data for extant ungulates and elephants were drawn from solounias and semprebon (2002) and those of palaeoloxodonts specimens from neumark nord 1, la polledrara di cecanibbio and casal de’pazzi were drawn from grube et al. (2010). men and elephants in prehistoric maremma from -23.1‰ to -28.1 (grube et al., 2010). the collective data drawn from the literature indicate that the average climatic and environmental conditions inferred for the elephants from the so-called “campagna romana” and from neumark nord 1 were similar to those that existed at poggetti vecchi. the water δ18ow at poggetti vecchi (-6.18 ‰) is slightly more positive than those calculated for the comparative samples (palombo et al. 2005; grube et al., 2010); in addition, it seems in equilibrium with the isotopic values of modern local precipitations (which range from -6‰ to -7‰; giustini et al., 2016). we can therefore conclude that the poggetti vecchi elephants likely relied on two sources of drinking water, i.e., ponds/lakes (filled with local rainwater) and rivers. our results are in line with the general environmental scenario for the middle pleistocene of central italy. the isotopic signature of enamel is consistent with a landscape dominated by wooded grasslands, under colder and/or wetter conditions than the present ones. the dietary shift towards more grazing habits in the poggetti vecchi population of palaeoloxodon antiquus can be a response to more humid conditions; in other words, the poggetti vecchi elephants had to turn to grass-eating, as living elephants do today in special seasonal circumstances. the results here presented confirm that microroughness features can be effectively described using 2d-roughness criteria, as previously inferred by kaiser & brinkmann (2006), as well as using geometry calculations. the selected subset of parameters is capable to measure the scale of surface alterations recorded by the system and, consequently, capture conventional microwear signals. in this study roughness parameter calculations fall within the thresholds of grazerdominated animals with mixed-feeding habits. the polar spectrum shows that the angular data vary widely, which indicates the lack of mainly unidirectional structures and, therefore, the absence of strong anisotropy signals. this is corroborated by the relatively higher average values of the fractal dimension calculations, which clearly indicate that both molars (m3 n.5500 and m1 n. 98) here studied have quite complex surface textures. compared to the other methods here considered mesowear is faster, not exposed to the risks of contamination, non-destructive, easy-to-do and widely applicable. it provides a direct indication of the amount of abrasive and nonabrasive plants regardless of the photosynthetic pathways employed by the terrestrial plants, and allows the detection of c3-grazing, more directly than using δ13c values. based on the mesowear results, the poggeti vecchi straight-tusked elephants had a browsedominated, mixed diet with relatively flexible feeding behaviors. the weak positive correlation between the mean angle measure and the percentage of poaceae pollen confirms this indication. this mismatch could be essentially due to differences in the temporal resolution of microwear and mesowear methods. in addition, considering that palaeoloxodonts shifted from more browsing or mixed-feeding to more grazing in accordance with local context, mesowear is probably more effective than microwear in capturing the minimum seasonal variations in diet. acknowledgements special thanks go to francesco landucci for supporting me during the preparation of molds and casts, to orlando vaselli for logistics support and for granting me access to the geochemistry lab. i am grateful to jacopo crezzini and francesco boschini (university of siena) and simona raneri (university of pisa) for helping me with topographic and roughness analysis. references ayliffe l.k., chivas a.r., leakey, m.g. (1994) the retention of primary oxygen isotope compositions of fossil elephant skeletal phosphate. geochimica et cosmochimica acta, 54, 5291-5298. benvenuti m., bahain j. j., capalbo c., capretti c., ciani f., d’amico c., esu d., giachi g., giuliani c., gliozzi e., lazzeri s., macchioni n., mariotti lippi m., masini f., mazza p.p.a., pallecchi p., revedin a., savorelli a., spadi m., sozzi l., vietti a., voltaggio m., aranguren b. (2017) paleoenvironmental context of the early neanderthals of poggetti vecchi for the late middle pleistocene of central italy. quaternary research, 88(2), 327344. cerling t.e., wittemyer g., rasmussen h.b., vollrath f., cerling c.e., robinson t.j.,douglas-hamilton i. (2006) stable isotopes in elephant hair document migration patterns and diet changes. proceedings of the national academy of sciences of the united states of america, 103, 371-373. cerling t.e., wittemyer g., ehleringer j.r., remien c.h., douglas-hamilton i. (2009) history of animals using isotope records (hair): a 6-year dietary history of one family of african elephants. proceedings of the national academy of sciences of the united states of america, 106, 8093-8100. chenery c.a., pashley v., lamb a.l., sloane h.j., evans j.a. (2012) the oxygen isotope relationship between the phosphate and structural carbonate fractions of human bioapatite. rapid communications in mass spectrometry, 26, 309-319. daux v., lécuyer c., héran m. a, amiot r., simon l., fourel f., martineau f., lynnerup n., reychler h., escarguel g. (2008) oxygen isotope fractionation between human phosphate and water revisited. j. hum. evol., 55, 1138. giustini f., brilli m., patera a. (2016) mapping oxygen stable isotopes of precipitation in italy. journal of hydrology: regional studies, 8, 162-181. grube r., palombo m.r., iacumin p., di matteo a. (2010) what did the fossil elephants from neumark nord eat? in: h. meller (ed.), elefantenreich eine fossilwelt in europa. lansdmuseum fur vorgeschichte, halle, 253-272. isbn 978-3-93941448-3. iso 4287 (1997) geometrical product specifications (gps) surface texture: profile method terms, definitions and surface texture parameters. replaces iso 4287-1, 1984. 118 capalbo c. kaiser t.m., brinkmann g. (2006) measuring dental wear equilibriums the use of industrial surface texture parameters to infer the diets of fossil mammals. palaeogeography, palaeoclimatology, palaeoecology, 239, 221-240. palombo m. r., filippi m., iacumin p., longinelli a., barbieri m., maras a. (2005) coupling tooth microwear and stable isotope analyses for palaeodiet reconstruction: the case study of late middle pleistocene elephas (palaeoloxodon) antiquus teeth from central italy (rome area). quaternary international, 126-128, 153-17. rivals f., semprebon g., lister a. (2012) an examination of dietarydiversity patterns in pleistocene proboscideans (mammuthus, palaeoloxodon and mammut) from europe and north america as revealed by dental microwear. quaternary international, 255,188-195. saarinen j., karme a., cerling t. et al., 2015. a new tooth wear-based dietary analysis method for proboscidea (mammalia). journal of vertebrate paleontology, 35. saarinen j., lister a. m. (2016) dental mesowear reflects local vegetation and niche separation in pleistocene proboscideans from britain. journal of quaternary science, 31(7), 799-808. solounias n., moelleken s. m. c (1992) -tooth microwear analysis of eotragus sansaniensis (mammalia: ruminantia), one of the oldest known bovides. journal of vertebrate paleontology, 12 (1), 113-121. solounias n., semprebon g. (2002) advanced in the reconstruction of ungulate ecomorphology with application to early fossil equids. american museum novitates, 3366, 1-49. sukumar r., ramesh, r. (1995) elephant foraging: is browse or grass more important? in: daniel j. c., datye h. (eds.), a week with elephants. bombay natural history society, bombay, india, 368-374 todd n. e, falco n., silva n., sanchez c. (2007) dental microwear variation in complete molars of loxodonta africana and elephas maximus. quaternary international, 169-170, 192-202. 119 men and elephants in prehistoric maremma ms. received: may 7, 2018 final text received: may 21, 2018 120 amq28(2)111-120 ferrario rivisto 12_2015.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 28 (2), 2015, 111 120 buried landscapes: geoarchaeology of the roman harbor of como (n italy) maria francesca ferrario, fabio brunamonte, arianna caccia, franz livio, elisa martinelli, eleonora mazzola, alessandro m. michetti, silvia terrana dipartimento di scienza e alta tecnologia, università degli studi dell’insubria, como, italy corresponding author: m.f. ferrario <francesca.ferrario@uninsubria.it> abstract: the town of como (n italy) was founded in 59 bc on the shores of the homonymous lake. its present-day environmental setting derives from the interactions between lacustrine, alluvial and human dynamics. the lake coastline moved through time because of alluvial progradation, town expansion and land reclamation. since 1700 ad, more than 200 m of land reclamation towards the north are observed from historical maps of the study area. the harbor is a strategic infrastructure for a coastal town and its localization is a critical issue. archaeological evidence found in the como urban area points to a different position of the harbor during the roman period and the middle ages; presently, those areas are buried below several meters of sediments due to land subsidence and the artificial filling of coastal areas. the results of a geoarchaeological study aimed at understanding the evolution of the coastal area are presented here. adopted methodologies include the collection of available archaeological and stratigraphic data and the analysis of a number of continuous core drillings both on the lake promenade and, for the first time in como, on the lake bottom. sedimentological and geotechnical investigations were performed and archaeological and vegetal findings were studied. a lithological unit consisting of organic silts rich in vegetal remains and archaeological findings has been identified. the thickness of this unit varies from less than 1 meter to 6 meters and it refers to a depositional environment characterized by shallow water and human influence; its deposition started during roman age, when the town was founded and an impressive reorganization of the drainage network took place. geological cross-sections and map reconstructions enable us to define different phases of the town evolution. our results highlight the role of geological research in reconstructing the recent evolution of buried and/or submerged environments: geoscience provides useful information when it is not possible to carry out expensive archaeological excavations at sensitive sites and allows to optimize resource utilization. keywords: geoarchaeology; paleoenvironmental reconstruction; sedimentological analysis; lacustrine harbor; como 1. introduction in areas of ancient civilization, the present-day urban setting can be understood only considering the interaction among natural and cultural factors. geosciences are able to unveil the paleogeography and archaeological evolution at sensitive sites, such as coastal environments. the town of como (n italy) offers the opportunity to apply a geoarchaeological approach at a lacustrine coastal site. sedimentary sequences on the present-day coastal and harbor areas have been analyzed applying a “modern analogue” approach: their sedimentary signature is compared with stratigraphic and archaeological data available for several sites presently buried below the modern town and interpreted as urban harbors (sensu marriner & morhange, 2007) that were in use during different times since the foundation of the town in the roman period. ancient harbors are unique archives of information concerning natural processes, climate forcing, occupation history and human use of a coastal or fluvial area; the study of harbor environments can shed light on the relations between natural dynamics and evolving human societies. a complete investigation has to deal with several scientific disciplines, such as archaeology, history, geology, geomorphology, biology and geochemistry; only through a multifaceted approach it is possible to crosscheck the results obtained by single techniques, that integrate and provide complementary data. the goals of the present research can be summarized as follows: (i) reconstruct the development of the area at the interface between land and the lake by means of a multidisciplinary approach including lithological, sedimentological and geotechnical analyses and geologic cross-sections; (ii) constrain the evolution of the coastline and harbor infrastructures, both in time and space; (iii) differentiate natural and human-induced modifications on the local environmental setting; (iv) acquire independent experimental data derived from the analysis of sedimentary sequences drilled in the coastal area, in order to integrate them with already existing archaeological data. 2. geologic setting and como town stratigraphy the town of como lies at the sw end of the western branch of lake como, located at the foothills of the southern alps and characterized by a lambda-shape. lake como main tributaries are located in the northern sector, whereas the only emissary outflows at the se termination of the lake, then reaching po river. the closed, western branch of the lake is thus a perfect sedimentary trap, which collects sediments from a huge drainage basin, more than 4500 km2 wide (fig. 1a). the historical downtown is built on a nw-se elongated alluvial plain, gently rising from lake level (198 m a.s.l.) to 220 m a.s.l. at its southern margin. two creeks, the cosia and valduce, drain the plain and strongly influenced the evolution of the town, and specifically of the area at the interface with the lake, in the last millennia. nowadays they have been forced to flow underground, beneath the urban area, till their outlet into the lake (fig. 1b). the sedimentary basin hosting the town is composed of more than 180 m of late quaternary loose sediments, settled in lacustrine, palustrine and fluvial environments. the basin is enclosed by two bedrock slopes, composed by mesozoic pelagic carbonates (medolo group – early jurassic) to the ne, and deep sea turbiditic conglomerates (gonfolite group – oligo-miocene) to the sw (fig. 1b; michetti et al., 2013). the gonfolite group and the mesozoic units are in tectonic contact along the gonfolite backthrust, a major regional n-verging structure bordering the como urban area to the sw. fault activity is testified by deformed pliocene-toquaternary sediments (e.g., bernoulli et al., 1989) but also more recent evidence of fault displacement, dating to pleistoceneholocene times, is recorded (livio et al., 2011; michetti et al., 2012). 3. dataset 3.1. como town stratigraphy in the last 40 years, several efforts have been conducted in order to reconstruct the stratigraphic setting of the como urban area. during 1970s, a strong input to this research derived from the studies aimed at comprehend and mitigate the effects of land subsidence, namely the occurrence of severe damage to buildings; it was ascertained that subsidence was due mainly to the overexploitation of groundwater from the deep aquifer (comune di como, 1980). since then, several studies dealt with the hydrogeological and environmental setting, the landscape evolution and with the geohazards of this area (e.g., bini, 1987; comerci et al., 2007; comune di como, 2011 and references therein). the general stratigraphy of the como basin is based on the collection of more than 250 borehole logs, covering a territory of ca. 5 km2 and including the entire urban area (fig. 2). chronological data derives from twelve 14c dating (comerci et al., 2007; ferrario et al., 2015b) covering the time period since ca. 18 cal ka bp. seven lithological units, here described from the top, were defined (comune di como, 1980; comerci et al., 2007; ferrario, 2013); borehole logs were analyzed accounting for the description of grain-size distribution, color, organic and artifact content and, where available, geotechnical index properties. unit boundaries are based on lithological variations or appearance/ disappearance of indicators such as archaeological or organic fragments. our classification corresponds only partially with lithostratigraphic units, because our definition is primarily related to the deposition environment and the palaeogeography of the study area. this choice highlights lateral facies variations, one of the most prominent elements of interest for the present research. unit 1 is composed of heterogeneous reworked material (sands and fine gravels with silty matrix and 112 ferrario f. et al. fig. 1 a) geographical location of como town; lake como and po river drainage basins are also highlighted. b) simplified geologic map of the study area, modified after michetti et al., (2013). topo map: ctr (carta tecnica regionale), provided by regione lombardia, coordinate system: wgs84. fig. 2 map of the como urban area, showing location of boreholes, available 14c dating and archaeological findings. basemap source: http://services.arcgisonline.com/ arcgis/services sparse pebbles) with archaeological and vegetal remains. unit 2 is made up of coarse alluvial sediments related to the post-roman evolution of the cosia delta, after the diversion of the riverbed that was realized for the land reclamation of the como plain, as described below in more detail. unit 3 is constituted by highly compressible plastic silts rich in organic matter and archaeological remains including bricks, pottery, glass fragments and leather tiers. the unit gives a very clear signature on geotechnical probes and is interpreted as the filling of harbor areas (see section 5). unit 4 has a fluvial origin and is made up of holocene coarse sands and fine gravels. unit 5 is represented by laminated clayey silts with sandy horizons; vegetal fragments are dispersed or organized in aggregates or lenses. the unit deposited in a lacustrine\palustrine environment during latest pleistocene and holocene. the two lowermost units, not of interest for the present research, are constituted by late pleistocene inorganic sandy silts with dropstones (unit 6) and medium to coarse sands (unit 7) representative of distal and proximal glaciolacustrine environments, respectively. 3.2. historical evolution and archaeological data the archaeological and historical database for como is of excellent quality. the prehistorical, roman and historical evolution of the city has been the subject of several publications and technical reports (e.g., caniggia, 1968; luraschi, 1987, 2002; uboldi, 1993; jorio, 2004) and is briefly summarized below. the reconstruction is based on more than 100 findings in total, including masonries, pavings, floorings, burials, inscriptions and architectural elements (uboldi, 1993; fig. 2). the oldest human occupation in the area is dated to the iron age, when the mountain slopes surrounding the basin started to be colonized (uboldi, 1993). at that time, the plain was indeed an unhealthy, marshy area, frequently affected by debris flows and flooding events. the hypothesis that the plain was occupied by a roman military camp in the ii century bc is not accepted by all the authors (caniggia, 1968; luraschi, 1987). the foundation of novum comum is well dated and occurred in 59 bc under the roman consul gaius julius caesar. the location of the future town was selected in a strategic position on the lake shore, along the trade itinerary between mediolanum to the south, and central europe (rhine and danube valleys) to the north. the colonizers clearly aimed at taking advantage of lake como as a 60 km long n-s sailing route. the building of the town in the center of the sedimentary plain required an impressive reorganization of the drainage network and related mountain catchment. the cosia and valduce creeks were diverted from the center of the plain and forced to flow at the base of the sw and ne mountain slopes, respectively. northwards the town was naturally protected by the lake, whereas on the other three sides town walls were built. during i-iii century ad, several expansions towards the north are recorded, related to at least three phases of land reclamation (caniggia, 1968). since the beginning of middle ages (iv-v century ad), many more edifices were built close to the lake, but the coastline position was substantially stable till xviii century. historical sources, as well as archaeological findings, refer to different harbors; however, their precise location and the definition of the times in which were active are not well known. at piazza cacciatori delle alpi (fig. 2), during 1999-2000 archaeological excavations, three parallel structures interpreted as roman quays were unearthed (jorio, 2004); at piazza mazzini a monumental marble block resting upon wooden remains, interpreted as the rests of a boat, was found (uboldi, 1993). 4. methods the coastal area was studied through different drilling investigations aimed at characterizing the site for an engineering project for mitigating the flood hazard: 1997 drillings: 10 cores were drilled, each one 60 m deep; in situ tests were performed and 9 piezometer and a magnet extensometer were installed inside the drilling holes. laboratory tests were performed on 88 undisturbed and 9 remolded samples and 5 cptu tests were carried out. 2010 drillings: the survey was performed for hydrogeological purposes mainly; 11 piezometers were installed in drillings up to 25 m deep and a number of permeability tests were done. 2013 drillings: 5 continuous core drillings and 2 more cores for cross-hole seismic tests were realized; for the first time, some drillings were made on the lake bottom. subsoil properties in static and dynamic conditions were defined and in situ and laboratory tests were performed. 113 buried landscapes: the roman harbor of como (n italy) fig. 3 location of available stratigraphic data in the present coastal area and trace of the geologic sections (fig. 8). results gained from these investigations have been analyzed mainly from an engineering perspective (ferrario et al., 2013, 2015a, b). here we present the results of a geoarchaeological study conducted on new sedimentary sequences, collected in 2014 on the western portion of the lake shore. cores were drilled by a machine-operated drill rig, core diameter is 86 mm. a total of 6 cores, 30-to -40 m deep, were drilled on the promenade as well as on the lake bottom. five more cores, 10 m deep, were equipped with piezometers. ancient city maps and historical chronicles have been studied for precisely reconstructing changes in the coastline since xvii century ad (caniggia, 1968; gianoncelli, 1975): maps were georeferenced and line drawing of the main features was realized in arcgis environment. chronological constraints since latest pleistocene are provided by a number of 14c dating (comerci et al., 2007; ferrario et al., 2015b; tab. 1) obtained at several sites in the como basin and integrated with information deriving from the archaeological record (uboldi, 1993; jorio, 2004). calibration was carried out applying oxcal software (https://c14.arch.ox.ac.uk/oxcal/oxcal.html, last accessed january 2015) and the intcal13calibration curve (reimer et al., 2013). 4.1. drillings: in situ tests the elevation of each core was calculated based on the municipal 1:2,000 scale topo map acquired in 1994; the elevation of cores on the lake bottom was calculated by subtracting water depth at each point. digital photographs were taken of every sediment core and, as soon as the sediments were collected, pocket penetrometer and shear values were measured. a detailed lithostratigraphic description was based upon grain size estimation, texture, color (with munsell soil color chart), presence of organic substance and artifacts. peculiar archaeological findings and some organic sample suitable for 14c dating were collected. 4.2. drillings: laboratory tests two sediments were sampled for analysis under laboratory conditions: the main physical parameters and a preliminary estimate of the biological content were investigated. sampling was not based on a regular spatial interval, but more emphasis was put on the most interesting parts of the sequence, namely where lithological markers or peculiar sedimentary features are present. four different kinds of samples were taken: (i) ca. 100 g of wet sediments were collected in small plastic containers for texture analysis, exoscopic indicators (degree of roundness and angularity) and organic abundance estimation; at this stage of the research, 20 to 35 samples were taken for each of the 30-to-40 m deep drillings. (ii) a total of 21 samples for grain size analysis with sieving and sedimentation procedure were stored in plastic bags. (iii) natural density and unit weight were calculated on 109 samples collected through steel or plastic cylinders of known volume. (iv) undisturbed samples were taken with osterberg samplers for geotechnical probes. water content, grain size and unit weight have been determined on all the cores, indeed two specific cores (si7 and si12) were selected for determination of organic abundance. grain size determination was performed through sieving and sedimentation procedure, according to astm d422 procedure and results were statistically analyzed. bulk density was calculated dividing dry weight by the sampler known volume. sediment samples of the above-mentioned category (i) were analyzed with the following procedure: they were weighted immediately after the sampling and then oven dried at 105°c in order to calculate water content. they underwent mechanical sieving for sorting out coarse fraction (> 2 mm), very coarse sand (2 mm – 850 µm), medium to coarse sand (850 – 250 µm), fine sand (250 – 150 µm), very fine sand (150 – 63 µm) and silts/ clays fraction (< 63 µm). these categories were defined considering the predominance of fine sediments and the almost negligible amount of material larger than 250 µm. on the finest fraction color was determined using the munsell chart, whereas the sand fraction was examined under a stereoscopic microscope (carl zeiss kl 200, magnification 8 – 50 x). organic abundance, roundness and angularity were estimated by comparison with reference charts representing four classes (for organic abundance: 1, absent; 2, rare; 3, present; 4, abundant). 5. results and discussion obtained data allowed to document with unprecedented detail the holocene evolution of the area, the first human influence before the foundation of como and finally the dramatic hydraulic and geomorphic changes induced during roman and historical times. sedimentological proxies are discussed in the following according to their relation in respect of the local harbor evolution. 5.1. pre-harbor environment: natural processes and first anthropic influence during the last glacial maximum (lgm), the area nowadays hosting the town of como was fully covered by ice. the sedimentary sequence in the como basin was generated by the retreat of the glacier front towards the north: a proglacial lake formed at an elevation of 270 m a.s.l. and inorganic glaciolacustrine proximal (unit 7) and distal (unit 6) deposits settled. with the inception of a milder climate, the deposition of palustrine organic silts (unit 5) begun; this moment is dated at 18.5 – 17 ka bp (via valleggio and piazza verdi sites; comerci et al., 2007; ferrario et al., 2015b) and the lake stood at ca. tab. 1 14c-ams ages and calibration of wood fragments from core si3 on the lake shore area of como. 114 ferrario f. et al. 215 m a.s.l. vegetation history has been reconstructed by means of palaeobotanical analyses on the piazza verdi cores (martinelli, 2014). a succession starting from few pioneer herbaceous species, through arboreal species (lateglacial), continental forests (bölling/allerød interstadial) and mixed mesophilous forests (holocene) developed. the first human influence is attested on the basis of the local fire history since 8.2 ka bp and progressively intensified, because of deforestation, agriculture and livestock farming. unit 5 has been dated at several sites, namely s. abbondio (castelletti & orombelli, 1986; comerci et al., 2007), via valleggio (comerci et al., 2007) and piazza verdi (ferrario et al., 2015b). unit 5 was cored both in si12 (5.72 – 30.00 m depth) and si7 (17.37 – 40.00 m) drillings. it is constituted by sandy clays rich in organic matter and vivianite, an iron orthophosphate that is formed under reducing redox environments and alkaline conditions. the unit settled in a lacustrine-palustrine environment. vegetal fragments are dispersed or organized in aggregates or lenses. usually an alternation of mm-thick organic strata and mm-to-cm inorganic strata is present. locally, layers are convolute or inclined up to 40° and flame-structures (fig. 4b) are present, pointing to possible reworking of sediments. we interpreted these features as related to gas emission, but other triggering mechanisms cannot be ruled out, including sediment overload, earthquake shaking, storm, lake-level variations and biological activ 115 fig. 4 sedimentary structures and archaeological findings recovered from the drillings: a) unit 3 intercalated between anthropic reworked material of unit 1 (si1, depth: 6.70-7.20 m below ground surface, 2013 drillings); b) laminated structure and gas-emission features in unit 5 (si3, depth: 35.00-40.00 m, 2013 drillings). the holes in the core represents pocket penetrometer and vane borer measurements; c) pottery fragments, age uncertain (pz11, depth 7.20 m, 2014 drillings); d) glass fragment, early middle ages (si3, depth 8.00 m, 2013 drillings); e) and f) leather tiers, imperial age? (si3, depth 13.12-13.18 m, 2013 drillings). borehole location is shown in fig. 3. 115 buried landscapes: the roman harbor of como (n italy) ity. the elevation of the base of the unit was ascertained with the 1997 drillings and runs at 50-60 m depth in the western sector of the lake shore, while it increases to 20 m depth in the eastern sector. sedimentological analyses performed on 50 samples taken from cores si12 (fig. 5) and si7 (fig. 6) allowed to accurately characterize the index properties of unit 5. water content is highly variable in si12 (3590%), whereas in si7 is more clustered (35-60%); unit weight increases with depth, from ca. 10 to 16 kn/m3. the coarse fraction (> 2 mm) is very low, in the order of 1% and composed both by mineral or biological fragments; sand varies between 20 and 70%, with an average of 49% in si12 and 46% in si7. the finest fraction (< 63 µm) corresponds to 30 – 85% of the sediment texture (average 49 and 53% for si12 and si7, respectively). concerning the sand fraction, it is composed almost only by very fine sand (150 – 63 µm). the sedimentation of unit 5 went on for several millennia; the unit is generally overlaid by alluvial deposits. a wood fragment collected from si3 at 38.40 m depth (see fig. 3 for location) yielded an age of 7.5 ka bp (ferrario et al., 2015b; table 1). the boundary between unit 5 and 4 is a diachronic erosive surface, being younger moving towards the north. this limit has been dated at 5.8 and 4.5 ka bp at via valleggio and piazza verdi sites, respectively (comerci et al., 2007) and corresponds to the progradation of the cosia alluvial fan on the palustrine basin. considering the age difference and the distance between the two sites, an average velocity of progradation of almost 1 m per year can be estimated. the fast progradation abruptly ceased ca. 2 ka bp when the foundation of novum comum occurred. unit 4 thickness ranges from 10 to 25 meters, depending on the distance from the river course. the thickness rapidly decreases from south towards the lake, where the unit is absent. unit 4 was not cored during the 2014 drillings because it pinches out few meters southward. 5.2. harbor environment the boundary between unit 5 (or unit 4, where present) and the overlying unit 3 is an unconformity marked by: (i) the appearance of sandy clays of low consistence and extremely rich in water; ii) a change in color, from grey to dark brown; iii) the presence of archaeological findings (bricks, potsherds, glass); iv) a sharp signature on the geotechnical parameters, namely a decrease in cone resistance and an increase in the friction ratio recorded by cptus (ferrario et al., 2013). driven by these observations, we interpreted this limit as the harbor foundation surface (hfs, sensu marriner & morhange, 2007), marking the beginning of human modification of the basin. sediments of unit 3 are definitely homogeneous in lithology and belong to the oh-mh category in the casagrande plasticity chart; water content is extremely fig. 5 sedimentology and organic abundance of core si12. lithological description is based on in situ analysis of the core (cl: clay; si: silt; sa: sand; gr: gravel), whereas grain size, water content and unit weight derive from laboratory measurements. the abundance of organic material (org. abund., 1: absent; 2: rare; 3: present; 4: abundant) is estimated by means of a stereoscopic microscope. 116 ferrario f. et al. high (ca. 90%) and unit weight quite low (ferrario et al., 2015b). archaeological evidence based on chronology of masonries and materials (jorio, 2004) suggests that unit 3 begun to settle during the roman age, when the town was founded. before that period, the strong sedimentary supply of the streams resulted in an higher energy of the local environment. man-made interventions on the river courses promoted alluvial deposition on the western side of the plain, whereas in the central sector a low-energy environment with shallow waters developed enabling the deposition of unit 3. here, anoxic conditions are present and sediments are saturated with water, thus otherwise perishable biological and archaeological materials (leather, wood, peat, seeds) can be preserved. plastic silts and clays contain a coarser fraction made up by biological remains and artifacts (fig. 4). during roman age, the harbor environment was first located close to the present-day piazza mazzini (see fig. 2 for location), then moved towards the northeast (fig. 7) due to silting of the basin. harbor clays settled atop older sediments constituted by unit 4 or unit 5; a sequence of alternating strata of unit 4 and 3 is locally recorded in the western sector of the urban area, attesting for both lacustrine and alluvial floods. on the lake shore, the age of the unit has been bracketed between viii and xv century ad (si3; ferrario et al., 2013). a particular situation was encountered in si1, located on the eastern part of the lake shore (see fig. 3): here, a 70-cm thick layer belonging to unit 3 is intercalated within anthropic materials of unit 1 (fig. 4a). the lower part of unit 1 has been interpreted as a manmade filling built in order to protect a coastal infrastructure; unit 3 refers to a quiet environment developed for a short time and then covered by another phase of manmade filling accumulation, presumably related to the land reclamations occurred since xviii century. 5.3. post-harbor environment and the most recent evolution the upper limit of unit 3 can be defined as the harbor abandonment surface (has, sensu marriner & morhange, 2007). the abrupt boundary between fine silts of unit 3 and overlying coarser materials represents coastline progradation of both natural or man-made origin, which caused a silting of the harbor basin and its loss of functionality. in the southern and western sectors of the town, unit 3 is overlaid by the coarse sediments of unit 2: during historical times, alluvial floods promoted coastline progradation, culminated in the landlocking of the harbor basin. however, in the central and northern parts of the town, unit 1 lies in unconformity over unit 3, attesting to anthropic modification of the coastline. fig. 6 sedimentology and organic abundance of core si7. lithological description is based on in situ analysis of the core (cl: clay; si: silt; sa: sand; gr: gravel; symbol legend is shown in fig. 5), whereas grain size, water content and unit weight derive from laboratory measurements. the abundance of organic material (org. abund., 1: absent; 2: rare; 3: present; 4: abundant) is estimated by means of a stereoscopic microscope. 117 buried landscapes: the roman harbor of como (n italy) man-made fillings are constituted by medium-tocoarse sands and fine gravels with silty matrix; accumulation of blocks, mainly made of limestone, is recorded on the coastal area. on the lake shore area, unit 1 is typically younger than 200 years and reaches a maximum thickness of ca. 15 meters. the coastline evolution in the last centuries is constrained by old city maps (gianoncelli, 1975): at least three phases of land reclamation were realized in xviii-xix century. present-day piazza cavour was the dock of the town till 1870, when a notable reorganization of the coastline took place and the last marshy areas were reclaimed. coastal changes show a progressive regularization, obtained through the filling of natural coves. 5.4. geologic cross-sections stratigraphic data were arranged in two different cross-sections, illustrated in fig. 8. vertical and lateral facies changes are common and reflect the paleogeographic evolution of the area driven by natural as well as human-induced factors. unit thickness varies notably in limited planar extents, especially along the ns direction. instead, on the w-e direction, lithological units can be depicted along their extension along the lake shore. fig. 8b shows the main stratigraphic characteristics of unit 3: in the western part it overlies unit 4, whereas to the east it overlies unit 5. locally, a more complex setting is present, such as in correspondence with core si1: the interpretation drawn here suggests a lateral facies contact between unit 4 and unit 1, both passing to the top to unit 3 and finally to unit 1. in core si1 anthropic fills are present down to 13 m depth; the lower part is interpreted as a protective filling for coastal infrastructures, including a staircase. it was then submerged for a short period, testified by a 70-cm thick layer belonging to unit 3 at 6.70 – 7.30 m depth and then covered by another phase of man-made deposits (fig. 4a). 6. conclusions this paper illustrates geoarchaeological research that we performed on the como coastal area, essentially fig. 7 map of the como urban area, showing the holocene position of the cosia alluvial fan and the evolution in coastline and harbor position. modified after ferrario et al., 2013. 118 ferrario f. et al. based on the detailed analysis of sedimentary sequences sampled through extensive coring. our preliminary results allow to draw some conclusion, as summarized below: the comprehensive characterization of the area at the interface between land and the lake clearly shows the strong relationship existing between harbor evolution, natural events and human occupation; sedimentological analyses corroborate available stratigraphic and archaeological data and allow to draw geological cross-sections, aimed at reconstructing the local landscape evolution in the last millennia; the adopted methods, based on the integration of stratigraphic, sedimentological, geotechnical and archaeological proxies, document that a crossdisciplinary approach is the best strategy of investigation when natural and anthropic processes are superimposed within each other, as typically occur in the coastal settings of regions with ancient civilization; the model of the landscape evolution, if properly integrated in urban planning, is suitable for reaching a better management of the cultural heritage and for revealing possible risk for the local infrastructures and assets; geological techniques are an interesting option when it is not possible to perform archaeological excavations, due to technical difficulties (submerged environments, groundwater) or economic costs; the possibility offered by geoscience to use non-destructive methods is a valuable tool for the protection of very sensitive environments and heritages; obtained results provide guidance for future research involving the integration of the conspicuous geological and archaeological data available for the study area; the como case is one of the first lacustrine settings studied on a geoarchaeological basis. the main conclusions arising from the study therefore include not only the specific results achieved so far, but also interesting methodological opportunities for future research at como or in other similar lacustrine coastal sites. acknowledgements the authors would like to thank the como municipality; georicerche s.r.l. is acknowledged for the field investigations and for supporting 14c dating. topographic maps were provided by regione lombardia. giuseppe orombelli and paolo mozzi contributed to the improvement of the manuscript. references bernuolli d., bertotti g., zingg a. (1989) northward thrusting of the gonfolite lombarda (“south-alpine molasse”) onto the mesozoic sequence of the lombardian alps; implications for the deformation history of the southern alps. ecl. geol. helv. 82 (3), 841-856. bini a. (1987) l’apparato glaciale wurmiano di como. università degli studi di milano, ph.d. thesis. caniggia g. (1968) lettura di una città: como, pp. 46. castelletti l., orombelli g. (1986) una nuova data 14c per la storia della deglaciazione del bacino del lago di como. geogr. fis. dinam. quat. 9, 56-58. comerci v., capelletti s., michetti a. m., rossi s., serva l., vittori e. (2007) land subsidence and late glacial environmental evolution of the como urban area (northern italy). quaternary international 173 -174, 67-86. comune di como (1980) relazione di sintesi della commissione per lo studio dei fenomeni di subsidenza. documenti e ricerche, 34. comune di como (2011) documento di piano del pifig. 8 a) geological cross-section n-s oriented, located on the coastal area; b) geological cross-section w-e oriented, located on the lake shore. trace sections are visible in fig. 3. 14c dating performed on si3 are expressed in cal years bp with two standard deviation ranges. 119 buried landscapes: the roman harbor of como (n italy) ano di governo del territorio. http://www. comune.como. i t / c i t ta / te r r i to r i o /pgt/pg t documento-di-piano/ ferrario m. f. (2013) analisi e modellazione dei fattori geologico-ambientali nella localizzazione dei siti industriali: il caso del bacino padano. università degli studi dell’insubria, ph.d. thesis. http:// insubriaspace.cineca.it/handle/10277/503 ferrario m.f., brunamonte f., castelletti l., livio f., martinelli e., michetti a.m., motella s. (2013) historical shoreline evolution and the roman harbour in the como urban area: results from stratigraphic and geotechnical analyses. mappapers 1iii,72-76. doi:10.4456/mappa.2013.17. ferrario m.f., bonadeo l., brunamonte f., livio f., michetti a.m. (2015a) a model of como (n italy) urban subsurface: a multidisciplinary tool for hydraulic, hydrogeologic and subsidence risk management. engineering geology for society and territory-volume 5. springer international publishing, 2015. 899-902. ferrario m.f., bonadeo l., brunamonte f., livio f., martinelli e., michetti a.m., censi neri p., chiessi v., comerci v., höbig n. (2015b) late quaternary environmental evolution of the como urban area (northern italy): a multidisciplinary tool for risk management and urban planning. eng. geol. 193 (2015), p. 384-401 http://dx.doi.org/10.1016/ j.enggeo.2015.05.013. gianoncelli m. (1975) como e la sua convalle: indagine storica sull'origine ed evoluzione urbanistica dei borghi e corpi santi di como. new press (como). jorio s. (2004) una nuova proposta di localizzazione per il porto di como: i risultati dello scavo in piazza cacciatori delle alpi via gallio. rivista archeologica dell’antica provincia e diocesi di como 186, 231-244. livio f., berlusconi a., chunga k., michetti a. m., sileo g. (2011) new stratigraphic and structural evidence for late pleistocene surface faulting along the monte olimpino backthrust (lombardia, n italy). boll. soc. geol. it. 14, 17-25. luraschi g. (1987) como romana: le mura. in: como nell’antichità, soc. arch. com., 103-112. como. luraschi g. (2002) storia di como romana e del suo territorio, in “la provincia di como”, como 2002, 1 -38. marriner n., morhange c. (2007) geoscience of ancient mediterranean harbours. earth-science reviews, 80(3), 137-194. martinelli e. (2014) analisi palinologiche e geofisiche per la ricostruzione delle trasformazioni ambientali nella regione lariana tra tardiglaciale e olocene: nuovi dati dal sondaggio di piazza verdi a como. università degli studi dell’insubria, ph.d. thesis. http://insubriaspace.cineca.it/handle/10277/537 michetti a. m., giardina f., livio f., mueller k., serva l., sileo g., vittori e., devoti r., riguzzi f., carcano c., rogledi s., bonadeo l., brunamonte f., fioraso g. (2012) active compressional tectonics, quaternary capable faults, and the seismic landscape of the po plain (n italy). annals of geophysics, 55 (5), 969-1001; doi: 10.4401/ag-5462. michetti a.m., livio f., pasquarè f.a., vezzoi l., bini a., bernoulli d., sciunnach d. (2013) note illustrative della carta geologica d’italia, foglio 075 “como”. http://www.isprambiente.gov.it/media/ carg/75_como/foglio.html reimer p.j., bard e., bayliss a., beck j.w., blackwell p.g., bronk ramsey c., grootes p.m., guilderson t.p., haflidason h., hajdas i., hattè c., heaton t.j., hoffmann d.l., hogg a.g., hughen k.a., kaiser k.f., kromer b., manning s.w., niu m., reimer r.w., richards d.a., scott e.m., southon j.r., staff r.a., turney c.s.m., van der plicht j. (2013) intcal13 and marine13 radiocarbon age calibration curves 0-50.000 years cal bp. radiocarbon 55 (4), 1869-1887. uboldi m. (ed.) (1993) carta archeologica della lombardia. como. la città murata e la convalle. franco cosimo panini, modena. ms. received: may 20, 2015 final text received: june 18, 2015 120 ferrario f. et al. amq abs marchegiano et al palcom 147-150.pub available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 147 150 rapid late pleistocene climate change reconstructed from a lacustrine ostracod record in central italy (lake trasimeno, umbria): preliminary results marta marchegiano 1, david j. horne 2, elsa gliozzi 3, daniel ariztegui1 1 department of earth sciences, university of geneva, geneva, switzerland 2 school of geography, queen mary university of london, london, uk 3 department of science, university roma tre, roma, italy corresponding author: m. marchegiano <marta.marchegiano@unige.ch> abstract: an 8.59 m long sediment core was retrieved from lake trasimeno (central italy) with the aim of performing a palaeoclimatic and palaeoenvironmental reconstruction. in this study we present, for the first time in central italy, a quantitative palaeotemperatures reconstruction based on ostracod assemblages. the mean winter (january) and summer (july) palaeotemperatures were estimated from 44,000 to 9,000 cal yr bp by using the mutual ostracod temperature range (motr) method. of the total of 19 ostracod species recovered, 13 of them were used as reliable palaeotemperature proxies on the base of their living temperature ranges. keywords: palaeotemperatures, palaeoclimatology, ostracoda, central mediterranean, quaternary 1. introduction the late quaternary climate has been affected by numerous and rapid fluctuations and different techniques have been developed to reveal their extent and associated effects on the environment. here we present for the first time the application of the mutual ostracod temperature range (motr) method (horne, 2007) on an 8.59 m long sediment core from lake trasimeno (central italy) with the aim of reconstruct the palaeotemperature variations in central italy. the provisional age model proposed by marchegiano et al. (2017a) suggests the co1320 trasimeno sediment core covers the last 47,000 cal yr bp. the motr analysis was performed within the interval from 44,000 to 9,000 cal yr bp. this period encompassed a long mild period (mis 3), followed by a colder one (mis 2) and ended with the beginning of the holocene, characterised by the abrupt restoration of warmer conditions. the mis 3 and 2 enclosed high-frequency climate variations characterised by warmer (interstadial) and colder (stadial) periods (abrantes et al., 2012). these features were recognized for the first time in the ice-core record from greenland (grootes & stuiver, 1997; johnsen et al., 1992) and subsequently documented in climate records all over the world (voelker, 2002). in central italy, several palynological studies (summarized in fletcher et al., 2010), revealed that the greenland interstadials (gi) were characterised by relatively humid conditions, whereas dry ones prevailed during greenland stadials (gs). this trend has been further confirmed at lake trasimeno (43°09’n; 12°06’e, umbria region, central italy) (fig. 1) by the repeated changes of the ostracod assemblages that suggested frequent lake level variations that mirrored the alternation of dry and humid phases (marchegiano et al. 2017a). due to its very shallow depth (maximum depth of 6 m), its smooth bathymetry (ludovisi et al., 2005) and its endorheic nature, lake trasimeno revealed to be particularly suitable to detect the changes in the lacustrine environment driven by climate, since its hydrological system strictly depends on climatically-governed precipitation/evaporation changes (dragoni et al., 2012). the continuous presence of fossil ostracods throughout the entire succession (marchegano et al., 2017a), allowed to fruitfully apply the motr method fig. 1 map of lake trasimeno showing the location of core co1320. legend: a. natural catchment area; b. artificially-joined basins; c. sluice gates of the artificially-joined channels (modified from marchegiano et al., 2017). https://doi.org/10.26382/aiqua.2018.aiquaconference along the sediment core, trying to depict, for the first time, the palaeotemperature variations based on ostracods. in fact, until today, only few continental records provided high-resolution analyses of late quaternary climatic changes, mainly based on pollen [e.g. lago di lagaccione (magri & sadori 1999), lago di vico (magri 1999, magri & parra 2002), lago di albano (ariztegui et al., 2001), valle di castiglione (magri, 1994), lago di monticchio (allen et al., 1999), lake ohrid (wagner et al., 2017)]. 2. methods the motr is a non-analogue method (horne, 2007) for reconstructing palaeotemperature using freshwater fossil ostracod assemblages, based on the species still living today with a known climatic distribution. the temperature ranges, which enclose all the living records of the species, are determined by fitting worldclim database (version1.3) (hijmans et al., 2001) to the mapped coordinate points of the species’ distribution and are expressed in terms of the maximum and minimum values of july and january temperature ranges. the temperature reconstruction for a given interval is provided by the mutual temperature range of all the species in the fossil assemblage. (i.e. the t interval in which they could have co-existed fig 2.). 3. results a total of three hundred and fifty samples were analysed to perform the motr method in the trasimeno sedimentary core. the ostracod analyses (marchegiano et al., 2017a) enabled recognition of 19 different species of ostracods referable to 15 genera: cyprideis torosa, candona angulata, candona neglecta, candona candida, heterocypris incongruens, cytheromorpha fuscata, sarscypridopsis aculeata, heterocypris salina, ilyocypris sp., eucypris mareotica, darwinula stevensoni, limnocythere inopinata, limnocythere blankenbergensis, potamocypris paludum, trajancypris serrata, amnicythere sp., herpetocypris helenae, cypridopsis vidua, plesiocypridopsis newtoni. among all of the recovered species, cyprideis torosa was not taken into account because is a typically brackish water species (although it occurs sometimes in freshwater) while the motr method is developed only for freshwater species. other species were also excluded: amnicythere sp. and ilyocypris sp., for reasons of taxonomic uncertainty, and trajancypris serrata, potamocypris paludum and herpetocypris helenae, which are still not calibrated. the temperature ranges were calculated for all the samples from 7.4 to 3.1 m depth in the co1320 trasimeno core to obtain the palaeotemperature variations during the whole sequence, represented by reconstructed palaeotemperature ranges to which maxima and minima curves can be fitted. 4. discussion and conclusions although the mutual ostracod temperature range method has been frequently applied to infer past climate conditions (horne, 2007; horne et al., 2012; pint et al., 2015; cosentino et al. 2017; benvenuti et al. 2017), in this contribution it was used, for the first time, to reconstruct a palaeotemperature curve similar to those derived from other usual proxies (e.g. isotopes, pollen and beetles (inter alia atkinson et al., 1987-1986; allen et al., 1999; pross et al., 2000; pross & klotz, 2002). notwithstanding uncertainties regarding where (within the reconstructed ranges) the actual temperatures were located, a preliminary inspection of the motr results suggests rapid temperature changes in central italy in the interval from 44,000 to 9,000 cal yr bp. in order to compare the global temperature changes of this period with the ones that affect central italy, the motr-derived curves have been compared with the greenland isotopic palaeotemperature reconstruction (ngrip-members, 2004). despite limitations of the use of a provisional age-depth model, the january 148 marchegiano m. et al. fig. 2 example of the application of the motr method on sample 374 of the co1320. 149 and july temperature curves show a remarkable correspondence with features of the ngrip-record, demonstrating their ability to record the millennial climate variations. the trasimeno motr reconstruction also reveals the possible occurrence of rapid climate changes, which could be considered equivalent to those observed at monticchio lake by allen et al. (1999) using pollenbased reconstruction methods. these qualitative correspondences demonstrate for the first time the potential of the motr method to reconstruct rapid climate changes, and efforts are in progress to validate and refine this preliminary result. references abrantes f., voelker a. helga l., sierro f.j., naughton f., rodrigues t., cacho i., ariztegui d., brayshaw d., sicre m. a., batista l. (2012) paleoclimate variability in the mediterranean region, in: the climate of the mediterranean region. elsevier, 186. allen j.r., brandt u., brauer a., hubberten h.w., huntley b., keller j., kraml m., mackensen a., mingram j., negendank j.f., others (1999) rapid environmental changes in southern europe during the last glacial period. nature, 400, 740-743. ariztegui d., chondrogianni c., lami a., guilizzoni p., lafargue e. (2001) lacustrine organic matter and the holocene paleoenvironmental record of lake albano (central italy). journal of paleolimnology, 26 (3), 283-292. atkinson j.c., briffa k.r., coope g.r. (1987) seasonal temperatures in britain during the past 22,000 years, reconstructed using beetle remain. nature, 325, 587-592. atkinson t.c., briffa k.r., coope g.r., joachim m.j., perzy d.w. (1986) climatic calibration of coleopteran data, in: handbook of holocene palaeoecology and palaeohydrology. wiley, new york, 851858. benvenuti m., bahain j., capalbo c., capretti c., ciani f., d’amico c., esu d., gianchi g., giuliani c., gliozzi e., lazzeri s., macchioni n., mariotti lippi m., masini f., mazza p. p. a., palecchi p., revedin a., savorelli a., spadi m., sozzi l., vietti a., voltaggio m., aranguren b. (2017) paleoenvironmental context of the early neanderthals of poggetti vecchi for the late middle pleistocene of central italy. quaternary research, 88(2), 327344. cosentino d., asti r., nocentini m., gliozzi e., kotsakis t., mattei m., esu d., spadi m., tallini m., cifelli f., pennacchioni m., cavuoto g., di fiore v. (2017) new insights into the onset and evolution of the central apennine extensional intermontane basins from the tectonically active l'aquila basin (central italy). geological society of america bulletin, 129, 1314-1336. dragoni w., melillo m., giontella c. (2012) bilancio idrico del lago trasimeno, in: tutela ambientale del lago trasimeno. libri arpa umbria, perugia, 69-85. groote p.m., stuiver m. (1997) 18o/16o variability in greenland snow and ice with 10-3 to 105 year time resolution. journal of geophysical research, 102 (26), 455-470. fletcher w.j., sánchez goñi m.f., allen j.r.m., cheddadi r., combourieu-nebout n., huntley b., lawson i., londeix l., magri d., margari v., müller u.c., naughton f., novenko e., roucoux k., tzedakis p.c. (2010) millennial-scale variability during the last glacial in vegetation records from europe. quaternary science reviews, 29, 28392864. hijmans r.j., guarino l., cruz m., rojas, e. (2001) computer tools for spatial analysis of plant genetic resources data: 1. diva-gis. plant genetic resources newsletter, 127, 15-19. horne d.j. (2007) a mutual temperature range method for quaternary palaeoclimatic analysis using european nonmarine ostracoda. quaternary science reviews, 26, 1398-1415. horne d.j., holmes j., rodriguez-lazaro j., viehberg f.a. (2012) ostracoda as proxies for quaternary climate change. development in quaternary science, amsterdam. johnsen s.j., clausen h.b., dansgaard w., fuhrer k., gundestrup n., hammer c.u. (1992) irregular glacial interstadials recorded in a new greenland ice core. nature, 359, 311-313. ludovisi a., minozzo m., pandolfi p., taticchi m.i. (2005) modelling the horizontal spatial structure of planktonic community in lake trasimeno (umbria, italy) using multivariate geostatistical methods. ecological modelling, 181, 247-262. magri d. (1994) late quaternary changes of plant biomass as recorded by pollen stratigraphycal data: a discussion of the problem at valle di castiglione, italy. review of palaeobotany and palynology, 81, 313-325. magri d. (1999) late quaternary vegetation history at lagaccione near lago di bolsena (central italy). review of palaeobotany and palynology, 106, 171 -208. magri d., parra i. (2002) late quaternary western mediterranean pollen records and african winds. earth planetary science letters, 200 (3-4), 401408. magri d., sadori l. (1999) late pleistocene and holocene pollen stratigraphy at lago di vico (central italy). vegetation history and archeobotany, 8, 247-246. marchegiano m., francke a., gliozzi e., ariztegui d. (2018) arid and humid phases in central italy during the late pleistocene revealed by the lake trasimeno ostracod record. palaeogeography. palaeocimatology, palaeoecology, 490, 55-69. marchegiano m., gliozzi e., ceschin s., mazzini i., adatte t., mazza r., ariztegui d. (2017) ecology late pleistocene climate change in central italy and distribution of living ostracod assemblages in a shallow endorheic lake: the example of the lake trasimeno (umbria, central italy). journal of limnology, 76(3), 457-475. ngrip-members (2004) high-resolution record of northern hemisphere climate extending into the last interglacial period. nature, 431, 147-151. pint a., frenzel p., horne d.j., franke j., daniel t., burghardt a., funai b., lippold k., daut g., wennrich v. (2015) ostracoda from inland waterbodies with saline influence in central germany: implications for palaeoenvironmental reconstruction. palaeogeography palaeoclimatology palaeoecology, 419, 37-46. pross j., klotz s. (2002) palaeotemperature calculations from the praetiglian/tiglian (plio-pleistocene) pollen record of lieth, northern german: implications for the climatic evolution of nweurope. global planetary change, 34, 253-267. pross j., klotz s., mosbrugger v. (2000) peconstructing palaeotemperatures from the early and middle pleistocene using the mutual climatic range method based on plant fossils. quateranry science reviews, 19, 1785-1799. wagner b., wilke t., francke a., albrecht c., baumgarten h., bertini a., combourieu-nebout n., cvetkoska a., d'addabbo m., donders t. h., föller k., giaccio b., grazhdani a., hauffe t., holtvoeth j., joannin s., jovanovska e., just j., kouli k., koutsodendris a., krastel s., lacey j. h., leicher n., leng m. j., levkov z., lindhorst k., masi a., mercuri a. m., nomade s., nowaczyk n., panagiotopoulos k., peyron o., reed j. m., regattieri e., sadori l., sagnotti l., stelbrink b., sulpizio r., tofilovska s., torri p., vogel h., wagner t., wagner-cremer f., wolff g. a., wonik t., zanchetta g., zhang x. s. (2017) the environmental and evolutionary history of lake ohrid (fyrom/albania): interim results from the scopsco deep drilling project. biogeosciences, 14, 2033-2054. 150 marchegiano m. et al. ms. received: may 3, 2018 final text received: may 24, 2018 imp.calderoni_russo geoarchaeological stratigraphy and radiocarbon datings of a deposit from a site of the pompeian area (campania, southern italy) gilberto calderoni 1 & filippo russo 2 1 dipartimento di scienze della terra, università “la sapienza”, p.le a. moro 5, 00185 roma. 2 dipartimento di studi geologici ed ambientali, università del sannio, via port’arsa 11, 82100 benevento. corresponding author, e-mail: filrusso@unisannio.it. abstract: g. calderoni & f. russo, geoarchaeological stratigraphy and radiocarbon datings of a deposit from a site of the pompeian area (campania, southern italy). (it issn 0394-3356, 2007). in 1996 the archaeological excavations at st. abbondio locality, a site ubicated on the top of a small, 15 m high a.s.l., hill made up by distinct tephra emplacements and located at the edge of the roman town of pompeii, provided new data of great geoarchaeological concern for detailing the local history of the settlement pattern and of the environmental land exploitation of the pompeian area far before the roman times. from a geomorphological literature we know that the local relief is a volcanic relict that some 5.5 ÷ 4.5 kyr b.p. limited eastward the local reach of the coastal plain, on which the roman town of pompeii flourished. briefly, the geoarchaeological analysis of the findings in a deposit discovered in the archaeological site, in fair agreement with the measured 14c ages, revealed that the site-area, first occupied by an early bronze age settlement, was used as a necropolis in the middle bronze age and then, following a long lasting abandonment, was exploited for intensive farming throughout hellenistic and roman times. the stratigraphic sequence exposed by the archaeologic excavations, included some distinct, rich in artefacts, anthropic levels confined between the tephra ejected by mt. vesuvius during the last two huge plinian eruptions of avellino (best 14c age: 1410 ± 40 yr b.c.) and pompeii (79 a.d.). the archaeological excavations at st. abbondio site yielded a reference stratigraphic sequence for the area, particularly valuable because it uncovered, both prehistorical and historical artefacts which are strictly associated with a changing of land use perhaps related with palaeoenvironmental changes induced by locally recurrent natural dramatic volcanic activity. riassunto: g. calderoni & f. russo, stratigrafia geoarcheologica e datazioni radiocarboniche di un deposito multistrato rinvenuto in un sito dell’area pompeiana (campania, italia meridionale). (it issn 0394-3356, 2007). nel 1996 nella località sant’abbondio a pompei, poco distante dall’area dei noti scavi archeologici dell’antica città di epoca romana, gli sbancamenti operati per la costruzione di un edificio consentirono la scoperta di una interessantissima situazione geoarcheologica grazie alla quale, per la prima volta nell’area pompeiana, venivano alla luce resti di insediamenti più antichi dell’età romana ed in particolare dell’età del bronzo. in un’area dove la stratigrafia geoarcheologica era limitata al periodo romano e tardo antico, finalmente si poteva così documentare una storia degli insediamenti, e quindi dell’uso del territorio, più antica di quanto fino ad allora era conosciuto. ma, dal punto di vista geologico ambientale, la cosa più straordinaria emersa dallo scavo archeologico è stata la constatazione dell’esistenza anche nell’area pompeiana di uno strato eruttivo riferibile all’eruzione pliniana del somma-vesuvio nota col nome di “eruzione di avellino”, occorsa circa 1400 anni a.c. uno strato eruttivo fino ad allora poco conosciuto nell’area e meno ancora la sua interazione locale con i resti archeologici pre-pompeiani. dallo stesso punto di vista, inoltre, se si considera che gli scavi archeologici pompeiani rappresentano il dramma di una antica città vesuviana distrutta e seppellita dalle vulcaniti dell’eruzione pliniana del 79 d.c., con questa scoperta non solo si documenta una analoga tragedia umana ed ambientale vissuta molto tempo prima dalle popolazioni italiche localmente residenti, ma si arricchiscono gli scenari catastrofistici che per l’area vesuviana, in generale, prospettano come difficoltosa l’interazione tra lo sviluppo dell’urbanizzazione ed i problemi di pericolosità legati al vulcanismo attivo dell’area. il sito archeologico di sant’abbondio è ubicato sulla sommità di una collinetta di origine vulcanica alta poco più di 15 m s.l.m. che limita verso nw la locale pianura alluvionale e costiera su cui prosperava la città romana di pompeii. in accordo con le datazioni radiocarboniche, i resti archeologici rinvenuti nelle sezioni stratigrafiche e nell’area dello scavo di sant’abbondio rivelano che il sito fu occupato inizialmente da un villaggio risalente al bronzo antico successivamente trasformato in necropoli durante il bronzo medio e poi, dopo un lungo periodo di abbandono, fu sfruttato, a partire dal periodo ellenistico dell’antica pompeii, per coltivazioni agricole, prima di essere definitivamente occupato, nel i sec. d.c., dai resti di una fattoria di campagna distrutta dall’eruzione del 79 d.c. nello scavo archeologico il livello eruttivo riferibile all’eruzione di avellino ricopre sicuramente, ma senza apparenti segni di distruzione, i resti archeologici del villaggio del bronzo antico; purtroppo, non sono chiari i rapporti tra questo livello ed i resti multistratificati della necropoli del bronzo medio. livelli vulcanoclastici alluvionali, depositi di origine antropica e suoli sepolti completano la successione stratigrafica verso l’alto, sulla quale sorgono i resti di una fattoria di epoca romana distrutta e seppellita sotto diversi metri dai lapilli e dalle ceneri vulcaniche dell’eruzione del 79 d.c. sui quali oggi si sviluppa una estesa area edificata. oltre all’importanza della successione sedimentaria geoarcheologica, il sito di sant’abbondio documenta anche un’interessante variazione temporale di uso del territorio con le connesse attività umane; un aspetto, questo, che, come ipotesi di lavoro, potrebbe benissimo essere imputato ai cambiamenti ambientali indotti localmente dall’impatto drammatico dell’attività vulcanica vesuviana. keywords: gran sasso massif, calderone glacier, glacial oscillations, holocene climate, little ice age. parole chiave: stratigrafia geoarcheologica, datazioni radiocarboniche, eruzioni vesuviane, età del bronzo, pompei. il quaternario italian journal of quaternary sciences 19(2), 2006 261-268 262 g. calderoni & f. russo 1. introduction since long ago the archaeological community is addressing considerable efforts to gaining deeper insights into the palaeoenvironmental changes experienced by the pompeian area through the last five millennia, helping to answer the still numerous open questions on the spread of intermittent settlements throughout the pompeian area prior to the foundation of the roman pompeii and subsequently to its burial in 79 a.d. it is stressed that the palaeoenvironmental assessment is crucial, as the area experienced huge natural events that seriously affected the behaviour, spread and choice of settlement sites of the local ancient populations. the geoarchaeological studies carried out in the pompeian area till now have focussed on the relationship between roman and post-roman urbanization with the peculiar physical characteristics of the local volcanic and alluvial environment (sarno river plain), also concerning natural catastrophic events like the negative impact of 79 a.d. plinian eruption of vesuvius on the local roman settlements and landscapes (sigurdsson et al., 1985; cinque & russo, 1986; albore livadie et al., 1990; comentale, 2005). whereas, nothing is known about the same relationships regarding older settlements with their land use; in fact, only a few and scattered evidences of prehistoric occupations have been reported from both the excavated areas of pompeii (brunsting, 1975; wynia, 1982; de caro, 1985) and the surrounding territory (brunsting, 1975 and references therein; albore livadie et al., 1990). the discovery of a bronze age necropolis at st. abbondio, a site adjacent to the roman town of pompeii (mastroroberto, 1997; 1998 a, b), revealed to be of great geoarchaeologic concern for this stretch of the campanian coast in that the systematic excavation yielded a stratigraphic sequence of occupation levels, rich in well defined artefacts, confined within volcano-sedimentary layers recording the occurrence of dramatic natural events (like the volcanic eruptions). in this paper we document for the first time a geoarchaeological stratigraphy of a pompeian area where the relationships existing between bronze age/roman settlements and plinian eruptive levels are clearly exposed having greatly modified the local landscape and the anthropic land use. 2. geomorphologic and stratigraphic setting of the pompeian area the pompeian area lies on the south-eastern edge of the somma-vesuvius volcanic complex, almost at the northern part of the coastal plain that stretches southward to the surrentine peninsula (fig. 1). despite the plain undergoing an almost continuous subsidence since pleistocene times (e.g., some 1.6 myr ago), the overall trend of coastline resulted in a significant progradation owing to the aggradation of the notable amount of tephra issued by the numerous nearby vents intermittently active during pleistocene and holocene times (cinque et al., 1987). fig. 2 points out that the monotonous, almost flat fig. 2 geomorphologic sketch map of the coastal plain and volcanic piedmont where the study site is ubicated. the former stationings of the coastline during the holocene are shown. schema geomorfologico del contesto di pianura costiera/piedimonte vulcanico in cui l’area di studio è inserita. si riportano alcuni stazionamenti olocenici della linea di costa nella piana. fig. 1location of the archaeological area of pompeii. localizzazione geografica dell’area archeologica di pompei. landscape of the coastal plain is only interrupted inland by the modest volcanic relief on which lies the roman town of pompeii and seaward, by systems of poorly developed, (cinque, 1991) subarcuate ridges made up by littoral sediments. these latter are the relics of former coastal features pointing to a complex geomorphologic evolution of the area particularly enhanced during the last 6 kyr. the oldest, more inland coastline is quite well marked by the topography of the plain and likely records the peak of the holocene marine ingression, here set at 5.6 kyr b.p. by 14c dating (cinque, 1991). a further, recentmost elongated coastal ridge occurs some 1 km seaward to the previous analogue feature. it accounts for a phase of sea level standing that, based on radiocarbon readings, lasted from 4.5 kyr b.p. through the 6th century b.c. (albore livadie et al., 1990). the results of geomorphologic and geologic studies on the filling sequence of the plain (barra et al., 1989; albore livadie et al., 1990) established that the coastline at the times of the huge 79 a.d. plinian eruption was almost parallel and shifted some 700 m inland relative to the present one. the sediment assemblage recording the coastline in roman times was found from 3 to 5 m below the present s.l., thus providing evidence of the huge subsidence experienced by the plain during the past two millennia. the archaeological site of st. abbondio is located (fig. 2) just 4 km southeastward the roman town of pompeii on a well defined topographic high, 15 m high, locally dominating the ca. 6 m a.s.l. alluvial coastal plain which stretches seaward from its foot. to the s the transition between the st. abbondio high and the underlying coastal plain occurs through a sharp erosion scarp, a feature previously reported from other nearby sites of the pompeian area and referred to as a inactive coastal cliff (cinque & russo, 1986). the stratigraphy of st. abbondio high mostly consists of tephritic-leucitic lavas emplaced by a local prehistoric eruptive centre of the sommavesuvius volcanic complex (cinque & irollo, 2004; di girolamo, 1968). the lava flows are discontinuously and uncomformably overlain by a sequence of tephra levels, in part reworked, with interbedded buried soils frequently containing archaeological remnants. on the top of lava flow, rolandi et al. (1997) has recognized, as the oldest tephra layer in the volcanic sequence of the area of the ruins of pompeii, a thin pumiceous-sandy level referred to the sarno eruption (ca. 17 kyr bp) of mt. somma-vesuvius. among the tephra layers, the thickest and mostwidespread, ashy and pumiceous in character, is that issued by the 79 a.d. vesuvius eruption responsible for the burial of pompeii (sigurdsson et al., 1985). 263geoarcheological stratigraphy and radiocarbon ... 3. chronostratigraphy of the deposit at st. abbondio site the archaeological site of st. abbondio was first reported in 1943, following the discovery of an isolated sanctuary devoted to dionysus that was dated back to the turn of the 2nd and 3rd centuries (elia & pugliesecarratelli, 1979). however, only following recent geophysical soundings (colombo et al., 1997) and systematic excavations (mastroroberto, 1997; 1998 a, b; d’ambrosio et al., 2001) a protohistorical necropolis, pointing to the occupation of the pompeian area during the bronze age, was found. the geoarchaeologic sequence investigated at st. abbondio is of great concern in that for the first time the remnants of the most ancient occupation so far uncovered over the area were found strictly associated with the tephra ejected by the somma-vesuvius during the huge plinian eruption referred to as “avellino’s eruption” (rolandi et al., 1993), which in nearby showings were dated (vogel et al., 1990) at 1410 ± 40 yr b.c. (calendar age: 1730 ÷ 1605 yr b.c.). the stratigraphy exposed on the walls of the excavated archaeological trench (fig. 3) consists of volcano-sedimentary sequences with interbedded buried soils. these latter features contain artefacts that point to several, distinct occupational phases and therefore provide us with a reference geoarchaeologic record for the area. at the bottom of the trench blackish tephritic-leucitic lavas (layer 1 in fig. 3) are exposed, with the typical silty-loamy, yellow-red coloured weathered cap (layer 2) that upward shows pedogenethic signs. evidences of human activity are scattered on the surface of the layer 2, sometimes they are (hut potholes – h in fig. 3) clearly cutting the layer itself. inside the upper part of the layer 2 were discovered lots of fig. 3 stratigraphy exposed on the walls of the trench excavated at st. abbondio archaeological site. key: see text. sezione geoarcheologica schematica esposta nelle pareti dello scavo archeologico di sant’abbondio (vedere il testo per la spiegazione dei numeri e delle lettere). 264 potsherds typologically assigned to the facies of palma campania (albore livadie, 1981) of the early bronze age. there is no sufficient data about but we think that the discovered pot-holes and potsherds are coeval and pertinent to the same, early bronze aged, primitive hut villages. the recognized graves (g) are shown in fig. 4. sometimes coalescent and containing personal belongings, they were covered and wall-faced with pebbles, cobbles and blocks (p) ranging in size from a few tens of cm up to 1 m wide, mainly composed of limestones, sandstones and lithified tuffs, subspherical in shape as a result of alluvial transportation. the graves cut the whole thickness of layer 2 and also the tracks of hut pot-holes; from an archaeological point of view in the outcropping area of graves there are no evidences of early bronze ages remnants. based on archaeological analysis the occurrence of graves could imply that the site was used as a necropolis, possibly at the boundary between early and middle bronze age (protoappenninico b). because there are no datable organic remains inside the pot-hole infillings, the approximate age of layer 2 can be deduced from the radiometric datings made on soil organic matter sampled from the layer itself. results of radiocarbon dating, carried out at the radiocarbon laboratory of the earth science department at rome university (calderoni & petrone, 1992), support the archaeological inferences in that the age of layer 2 is bracketed between 4900 ± 75 (rome979; bottom, calibrated age: 3760 ÷ 3640 yr b.c.) and 4300 ± 65 yr b.p. (rome-981, top, calibrated age: 3000 ÷ 2765 yr b.c.). this data set range archaeologically span throughout the copper age (from gaudo culture to andria-laterza facies), but unfortunately no archaeological data testifying the presence of copper age remnants in the st. abbondio site is documented. thus we accept as antequaem boundary the radiometric dataset obtained, believing them reliable. a 15 cm thick layer 3 of massive, ashy-glassysandy tephra, barren of any archaeological remnant, overlies conformably and continuously the previous layer. its overall features match those of the products, emplaced by the plinian avellino’s eruption of sommavesuvius (rolandi et al., 1993; ranieri & yokotama, 1997). apart from the lithological data the chronological assignment of layer 3 is also consistent with the results of two radiocarbon measurements (rome-980 and –982) on charcoal fragments that provided the weighted mean age of 3655 ± 40 yr b.p. (calendar age: 2110 1930 yr b.c.). in the archaeological site the charcoal fragments are positioned at the base of the layer 3. we suppose that the charcoal fragments could come from a very little lens, perhaps a hearth relic, hosted in an invisible erosional task on the top of layer 2. surely, there are no visible relationships between the supposed lens and the other anthropic remnants, but we believe that this supposed new anthropogenic level should be like an independent unit interposed between the layer 2 and the layer 3. upward a 20 cm thick ashly-sandy deposits (layer 4) occurs. it is devoid of archaeological remnants and displays clear signs of pedogenesis, such as sub-angular, weakly developed blocky structure, very dark brown colour, no hcl effervescence and very rare coarse fragments, these latter consisting of pumices of few millimetres in size: such pedogenic features strongly suggest that the soil at issue could represent the relict of a bw horizon of a soil developed from volcanic material and very probably displaying andic soil properties. such a soil developed atop the layer 3. the overlying layer 5, about 60 cm thick, consists of a reworked, roughly parallel stratified volcaniclastics alluvial conglomerates confined within two undulated surfaces likely affected by erosion. this is suggested by the occurrence of furrows (f), subtrapezoidally shaped and ca. 1 m wide, which record two parallel, nw-se aligned artificial channels possibly backdating to the times of the archaic pompeii (6th 4th centuries b.c.), as testif ied by artefacts discovered within (mastroroberto, pers. comm.). the top of level 5 shows a hearth floor (f), assigned to the middle of the 1st century a.d., complete of its foundation (h) composed by a mixture of volcanoclastic debris and hellenistic and roman potsherds dated from the end of the 3rd century b.c. to the middle of the 1st century a.d. layer 5 is capped by a 30 cm thick ashy-sandy deposit (layer 6) in which is founded a wall structure (w) relative to the late development of pompeii (62-79 a.d.). this layer displays clear signs of pedogenesis and consists of two soil horizons: the upper horizon, approximately 5 cm thick, is characterized by a verycoarse crumbly structure, very dark grey colour and no hcl effervescence and could be reasonably interpreted as the remnant of an a horizon; the lower horizon, approximately 30 cm thick, displays a moderately developed coarse sub-angular blocky structure, a dark greyish colour and no hcl effervescence: thus, it probably represents the remnant of a bw horizon. the overall soil developed from a volcanic parent material and probably displays andic soil properties. the soil is interested by subparallel ploughing furrows and further evidence of agricultural practices, is cut by an artificial, subtrapezoidally shaped channel (c) containing potsherds from the first half of the 1st century a.d. akin in the nearby archaeological area of pompeii, the studied geoarchaeological sequence is sealed by fig. 4 general view of the excavations at st. abbondio site (as of 1996). some of the uncovered graves (foreground) as well as features of the exposed sequence (background) are shown. features labeling as for fig. 3. veduta generale dello scavo archeologico di sant’abbondio nel 1996). i numeri e le lettere sono le stesse di fig. 3. g. calderoni & f. russo 265 the tephra (7), here only 2.5 m thick, issued by the 79 a.d. plinian eruption of vesuvius (yokoyama & marturano, 1997), with the present soil (8) at the top. from down to top, the layer 7 consists of white pumices (a) and two levels of grey pumices (b and d) alternating with two massive, pisolitic, ashy-sandy levels laid down by pyroclastic surges (c and e). 3.1. the new 14 c readings from the site of st. abbondio besides geomorphological and lithological considerations, valuable data for establishing the chronostratigraphy of the geoarchaeological deposit at st. abbondio were the 14c dates measured on materials in reliable association with the identified occupation phases of the site. in particular the dated materials were the topmost (rome-981) and lowermost (rome-979) portions of the buried soil referred as layer 2 and the charcoal from the fill of a lens, possibly a fire place remnant, underneath layer 3 (sample locations are given in fig. 3). the former sample pair was first pretreated for isolating the humic matter fractions of proved validity in 14c dating of paleosols (calderoni & turi, 1998), whereas the collected charcoal was split into subsamples rome-980 (smaller bits) and rome-982 (larger fragments) and routinely processed. following conversion into the benzene to be used as a counting medium, the 14c decay rate was measured by βspectrometry: details on sample processing, counting protocol, equipment and calculation of the conventional 14c ages were previously reported (calderoni & petrone, 1992). the results, both as conventional (yr b.p.) and calendar ages (yr b.c.) are shown in table 1. the sample pair from the fireplace (rome-980 and –982) yielded statistically indistinguishable ages (3690 ± 60 and 3620 ± 60 yr b.p., respectively) resulting in the 3655 ± 40 yr b.p. weighted mean. as suggested by the results of previous radiocarbon dating (calderoni & petrone, 1989) of nearby buried soils of comparable origin and development, the ca. 600 yr age difference between the base (rome-979, 4900 ± 75 yr b.p.) and the top (rome-981, 4300 ± 65 yr b.p.) of the dated buried soil from layer 2 is reasonably accounted for by the dynamics of the soil forming processes. the data pinpoints a significantly long time span of stable environmental conditions suitable for soil development, this being a notable event for the study area. finally, it is observed that the used tract of the calibration curve is quite favourable, in that it displays a smooth fluctuation pattern. as a result, according to the distribution (at ± 1 σ confidence level) of the relative area under the calibration curve the calendar intervals for samples rome-979 and -981 and the pair rome–980/-982 narrow to 3770-3635, 3035-2870 and 2035-1925 yr b.c. with a 96, 87 and 86% of probability, respectively. 4. final remarks although so far only the southernmost part of the study site has been systematically excavated, the obtained data proved quite adequate for assessing in fair detail the geoarchaeologic framework. furthermore, interbedded with and strictly associated to the layers several levels rich in prehistorical/historical evidences were found, effective for the archaeological setting, of human occupations. according to colombo et al . (1997) and mastroroberto (1997; 1998 a and b) the pot holes with associated potsherds and the graves (g) containing personal belongings 1 m deep, entrenched into the weathered part (layer 2) of the basal lavas flow, are related to two distinct human occupations, referred to the old bronze age and the transition to the middle bronze age, respectively. the age of the layer 2 is bracketed within the 3760 2990 yr b.c. calibrated time-span by two 14c readings and charcoal from upward the sequence yielded the 2100 1930 yr b.c. calendar interval. therefore the results of isotope dating suggest that during the bronze age the site witnessed two separate occupations over some less then two millennia, the last one lasting up to ca. 200 yrs prior to the 1730 1600 yr b.c. avellino’s eruption. the transition from prehistorical to historical times is marked by a 60 cm thick sandy matrix-supported conglomeratic deposit (layer 5) devoid of archaeological findings, points to an abandonment of the site. such a phase, lasted some 1000 yrs, spanning subsequently from the avellino’s eruption possibly up to the times of the archaic pompeii (6th through 4th century b.c.). we note that none of the features of the layer is suggestive of natural events of such a dramatic character to account for the absence of any hint of human presence over the area. the geoarchaeological deposit shows the most ancient and reliable traces of human activity in protohistorical/historical times at ca. 3.5 m deep, these being represented by the infilled trenches of two parallel ditches likely referred to the archaic pompeii (6th-4th century). just upward the re-settlement is strongly suggested by an almost complete hearth structure associated with hellenestic/ roman potsherds referred to from the 3rd century b.c. to the 1st century a.d. subsequently several table 1 14c readings for st. abbondio archaeological site. datazioni 14c effettuate nel sito archeologico di sant’abbondio. laborator identifier (rome) material stratigraphic conventional calibrated sample number location age (yr b.p.) age(1) (yr b.c.) 979 humic matter layer 2 4900 ± 75 3760 3640 981 humic matter layer 2 4300 ± 65 3000 2765 980 charcoal layer 3 3690 ± 60 2190 1945 982 charcoal layer 3 3620 ± 60 2030 1830 980/982 weighted mean 3655 ± 40 2110 1930 (1) calibration data set after stuiver & reimer (1993). geoarcheological stratigraphy and radiocarbon ... 266 aspects of the anthropic activity during the last development phase of pompeii are clearly well noticeable, e.g., a wall structure, potsherds, evidence of farming and water drainage. after which the archaeological sequence appears to have been suddenly sealed by the tephra of the 79 a.d. eruption. switching to the palaeoenvironmental changes of the area during the time span we are dealing with and taking into account the geomorphological evolution of the sarno plain resulting from the studies of albore livadie et al. (1990), we can conclude that at the times of the old bronze age occupation the topographic high of the study site ended with a sharp cliff directly on the coastline or on an alluvial coastal plain that, although subjected to fast progradation, was by far narrower than nowadays. subsequently, from 4.5 kyr b.p. the coastline migrated 1 km seaward where it stationed up to the 6th century b.c. given the above features it is conceivable that the area could have been attractive for the settlers because of its dominating location, availability of fertile soils as well as proximity to the exploitable resources of the sea and the coastal plain. so that the high of st. abbondio was abandoned after avellino’s eruption. with the soil formation on the top of layer 5, the anthropization of the st. abbondio area comes back and manufactured-structures serving the reclaiming and farming are made up, probably related to the expansion of the archaic pompei. since then and up to the first half of the 1st century only subordinate agricultural landscape changes and a discrete urbanization of the area had occurred; with the 79 a.d. plinian eruption the overall pompeian area was destroyed, completely buried, and for a long time forgotten till nowadays, thus also our site of st. abbondio was definitively abandoned. as a final remark we can conclude that the paper evidences the relationships striking the development of man and its activity in an area characterized by a strong volcanic hazard (somma-vesuvius active volcanic complex) and consequentially with high geomorphological dynamics (comentale, 2005): in fact, we document a changing of anthropic land use with several functions of the site during the epochs examined. furthermore, we also document a changing of topography with several elevations of the ground after every main sedimentary and catastrophic event. this prefigures a real risk situation still dominant unfortunately. this work has been made possible realized with the contribution of research funds (f.a.r., 2005) of the sannio university accounted to prof. f. russo. references albore livadie c., barra d., bonaduce g., brancaccio l., cinque a., ortolani f., pagliuca s. & russo f. (1990) evoluzione geomorfologica, neotettonica e vulcanica della piana costiera del fiume sarno (campania) in relazione agli insediamenti anteriori all'eruzione del 79 d.c. in: albore livadie c. & widemann f. (editors), “volcanologie et archeologie”, pact, 25, 237 256. albore livadie c. (1981) palma campania (napoli) resti di abitato del bronzo antico. not. scavi, 34, 59 -101. barra d., bonaduce g., brancaccio l., cinque a., ortolani f., pagliuca s. & russo f. (1989) evoluzione geologica olocenica della piana costiera del fiume sarno (campania). mem. soc. geol. it., 42, 255 267. brunsting h. (1975) forschungen im garten des m. lucretius fronto. in: andreae b. & kyrieleis h. (editors), “neue forschungen in pompeji und den anderen vom vesuvausbruch verschütteten städten“, recklinghausen, 198 -199. calderoni g. & petrone v. (1989) 14c tephrochronology with different fractions of paleosol humic matter at procida island (italy). radiocarbon, 31(3), 664 671. calderoni g. & petrone v. (1992) department of earth sciences at the university of rome radiocarbon dates i. radiocarbon, 34 (1), 105 113. calderoni g. & turi b. (1998) major constraints on the use of radiocarbon dating for tephrochronology. quaternary int., 47/48, 153 159. cinque a. (1991) la trasgressione versiliana nella piana del sarno (campania). geogr. fis. dinam. quat., 14, 63 71. cinque a. & russo f. (1986) la linea di costa del 79 d.c. fra oplontis e stabiae nel quadro dell'evoluzione olocenica della piana del sarno (campania). boll. soc. geol. it., 105, 111 121. cinque a., hossein h., laureti l. & russo f. (1987) osservazioni preliminari sull'evoluzione geomorfologica della piana del sarno (campania, appennino meridionale). geogr. fis. dinam. quat., 10, 161 174. cinque a. & irollo g. (2004) il “vulcano di pompei”: nuovi dati geomorfologici e stratigrafici. i l quaternario, 17, 101 116. colombo l., danzi m. & mastroroberto m. (1997) photogrammetric imaging for a necropolis of the bronze age. science and technology for cultural heritage, 6, 121 -127. comentale b. (2005) paléoenvironnements et occupation humaine en milieu volcanique: la plaine du vésuve (italie méridionale). in: allée p. & lespez l. (éditors), "l’érosion entre société, climat et paléoenvironnement. table ronde en l’honneur du professeur rené neboit-guilhot", presses universitaires blaise pascal, collection nature & société, clermont-ferrand, 3, 443 -446. d’ambrosio a., mastroroberto m., stefani g., rota l., melluso l., morra v., santangelo n., di maio g., sperandeo g. & deino a. (2001) assetto geoarcheologico dell’area pompeiana: nuovi dati per un’ipotesi di ricostruzione paleoambientale. pompei – scienza e società (a cura di guzzo p.g.), electa ed., milano, 1 – 207. de caro s. (1985) nuove indagini sulle fortificazioni di pompeii. aion, 7, 75 -114. di girolamo p. (1968) un esempio di lava schiuma (foam lava) in campania (lava schiuma di pompeii scavi). rend. accad. sc. fis. mat. in napoli, 35, 2 12. elia o. & pugliese carratelli g. (1979) il santuario dionisiaco di pompeii. la parola del passato, 34, 442 481. g. calderoni & f. russo mastroroberto m. (1997) scavo della necropoli in località s. abbondio di pompeii. riv. st. pompeiani, 8, 159 160. mastroroberto m. (1998a) la necropoli di s. abbondio: una comunità dell'età del bronzo a pompeii. in: guzzo p.g. & peroni r. (editors), atti del convegno "vulcanologia ed archeologia in campania", pompeii 21.12i.1996, napoli, 135 149. mastroroberto m. (1998b) la necropoli di s. abbondio. culto funerario a pompeii nell'età del bronzo. in: aa. vv., “pompeii oltre la vita. nuove testimonianze dalle necropoli”, catalogo della mostra della xiii settimana per i beni culturali e ambientali, antiquarium di boscoreale, 31.5.1998, pompeii, 7 14. ranieri s. & yokoyama t. (1997) the somma-vesuvius eruptions occurred between 3760 y. b.p. and ad. 79. opuscula pompeiana, 7, 33 50. rolandi g., mastrolorenzo g., barrella a.m. & borrelli a. (1993) the avellino plinian eruption of somma-vesuvius (3760 y.b.p.): the progressive evolution from magmatic to hydromagmatic style. j. volc. geot. res., 58, 67 88. rolandi g. (1997) the eruptive history of sommavesuvius. in: cortini m. & de vivo b. (editors), “volcanism and archaeology in mediterranean area”. publ. research signpost, trivandrum (india), 77 88. sigurdsson h., carey s., cornell w. & pescatore t.s. (1985) the eruption of vesuvius in a.d. 79. nat. geogr. res., 1, 332 387. stuiver m. & reimer p.j. (1993) extended c-14 data base and revised calib 3.0 c-14 age calibration program. radiocarbon, 35 (1), 215 230. vogel j.s., cornel w., nelson d.e. & southon j.r. (1990) vesuvius/avellino one possible source of seventeenth century bc climatic disturbances. nature, 344, 534 537. wynia s.l. (1982) the excavations in and around the house of m. lucretius fronto. in: “la regione sotterrata dal vesuvio. studi e prospettive”, napoli, 329 340. yokoyama t. & marturano a. (1997) volcanic products of the vesuvius eruption in ad. 79 at pompeii, italy. opuscula pompeiana, 7, 1 32. 267 ms. ricevuto il 20 febbraio 2006 testo definitivo ricevuto il 31 ottobre 2006 ms. received: february 20, 2006 final text received: october 31, 2006 geoarcheological stratigraphy and radiocarbon ... amq sr001 wolter 139-148.pub a review of methods used to investigate structural control on slope instability. andrea wolter engineering geology, gns science, avalon, lower hutt, new zealand. corresponding author: a. wolter <a.wolter@gns.cri.nz> abstract: many features and phenomena, such as slope morphology, climate, hydrogeological and hydrological conditions, and material strength, contribute to slope instability. one of the most important preconditioning factors, particularly in rock slopes, is structural control. structural control includes any tectonic processes or features that may influence landslide initiation, movement, or termination, including in situ stress conditions, discontinuities, faults, folds, and foliation. structures affect not only the failure geometry, such as headscarp shape, but also deposit volume, morphology, block size, damage, and emplacement behaviour. structural features and processes thus influence all aspects of landslide behaviour, from the development of unstable conditions to deposition. interestingly, mass movement studies can also highlight structures, and contribute to detailed mapping of previously unrecognised faults, folds, and other features. methods such as regional lineament mapping, traditional fieldwork, photography and photogrammetry, lidar surveys, insar interpretation, and numerical modelling are used to analyse structural features and processes related to slope instability. this short paper presents an overview of these methods and highlight their applications in a case study. keywords: structural control, slope instability, methods, vajont landslide. � available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 33 (2), 2020, 139-147 1. introduction structural geological features and processes, such as discontinuities, folds, faults, foliation, and in situ stresses, are recognised as important controls on slope instability, particularly in rock slopes (agliardi et al., 2001; stead and wolter, 2015) (fig. 1). in this context, discontinuities include pre-existing lineaments that may influence failure geometry and behaviour, whereas faults are lineaments that typically produce damage or shear zones of weaker material surrounded by more competent material (loew et al., 2012; milmo et al., 2014; bonilla-sierra et al., 2015). fold axes are commonly weak zones, and fold geometry may influence failure geometry (badger, 2002; jaboyedoff et al., 2011; humair et al., 2013). foliation may affect sliding zone development (braathen et al., 2004; adhikary and dyskin, 2007; vick et al., 2020). the tectonic inheritance and in situ stress conditions of a given slope influence slope stability, and rock mass behaviour and damage (hoek et al., 2009; ambrosi and crosta, 2011; agliardi et al., 2013; stead and eberhardt, 2013; elmo et al., 2018). inclusion of structural control analysis when studying mass movements contributes to improved understanding of failure preconditioning, initiation and behaviour at various scales, and ultimately to landslide hazard and risk reduction. for example, glastonbury and fell (2000) and stead et al. (2006) illustrated how structures affect failure mechanisms, from translational to complex multi-mechanism failure. recent analysis of structural control within the creeping moosfluh slope adjacent to the aletsch glacier in switzerland examines the application of sophisticated monitoring to determine the role of structural control in developing failure mechanisms and in slope stability evolution (glueer et al, 2019a, b; manconi et al., 2019). in troms, norway, vick et al. (2020) focus on rock slope deformations (rsds), highlighting the role of foliation, discontinuities, and faults in rsd formation and evolution and presenting a new geotechnical model for these failures. aside from recognising the importance of structural control as in the above examples, incorporating techniques traditionally used in structural geology into geotechnical assessments of slopes facilitates analysis and improves slope characterisation. for example, havaej and stead (2016) applied the concept of the strain ellipsoid to brittle fracture and damage in open pit mines and natural slopes, determining an “ellipsoid of damage”. the aim of this short paper is to provide a review of methods used to investigate the influence of structural geological features and processes on slope instability. methods are described in the next section, followed by a case study highlighting the application of several of these methods to the famous vajont landslide and a discussion of the methods. 2. methods analysis of slope stability has incorporated numerous techniques to improve understanding of failure mechanisms, including site investigations, drilling, groundwater, displacement and climate monitoring, geo https://doi.org/10.26382/amq.2020.05 140 wolter a. fig. 1 structural features and controls (such as folds, fault zones, rock bridges, crown cracks, transverse cracks and ridges, and radial cracks) on landslides, with methods used to investigate them represented by icons. see tab. 1 for legend of icons. tab. 1 summary of methods used to investigate structural features and processes affecting slope stability. note that field methods here include laboratory methods for simplicity. gsi = geological strength index; jrc = joint roughness coefficient; los = line-of-sight. 141 methods used for structural control on slope instability physical methods, remote sensing, and physical and numerical simulations. figure 1 and tab. 1 summarise the traditional and novel methods applied to the analysis of slope instabilities and their features, focussing on structural control and features, and separated into field methods, remote sensing and visualisation, and simulation and modelling. 3. case study 3.1. background the vajont landslide is a well-known ~270 million m3 event that failed catastrophically on october 9th, 1963 in the dolomites of northern italy, approximately 100 km north of venice (fig. 2). the failure initiated on the southern valley wall of the vajont valley on the flank of mt. toc (peak at 1921 m asl), above the vajont dam, which was the highest double-arch dam in the world at the time of the disaster. the sudden failure caused a displacement wave of the vajont reservoir that spread upvalley and downvalley, overtopped the dam, and flooded the main piave valley below. resulting in just under 2000 deaths, the vajont catastrophe is cited as one of the worst engineering and natural disasters in history. the landslide is among the most researched slope failures in the world, with over 200 studies on its geological, hydrogeological, geotechnical, and social aspects (cf. genevois and ghirotti, 2005; superchi et al., 2010; paronuzzi and bolla, 2012; genevois and tecca, 2013). several critical aspects, such as the significance of changing hydrological and hydrogeological conditions and centimetre-scale clay beds, and the existence of a “paleoslide”, have been discussed for decades (cf. hendron and patton, 1985; semenza, 2010). only recently have geomorphological and structural preconditions and regional evolution been investigated in relation to the vajont landslide. several compressional deformation events shaped the dolomites before and during the late miocene alpine orogeny, including the neoalpine and dinaric deformations. the e-w oriented vajont valley follows the erto syncline, an e-ese plunging recumbent fold that formed during the neoalpine event and was affected by the belluno thrust to the south and the monte borgá and spesse thrusts to the north. the vajont landslide is located on the southern refolded limb of the erto syncline (ravagnan, 2011; massironi et al., 2013). the recently recognised open massalezza syncline (massironi et al., 2013), with a fold hinge oriented n-s and located in the centre of the vajont landslide along the massalezza stream (fig. 2), is associated with the dinaric deformation event and creates the bowl shape observed in the landslide failure scar. interference patterns between the neoalpine and dinaric fold generations contribute to the complex morphology of the failure scar (bistacchi et al., 2015). two faults bound the vajont landslide. the col tramontin fault, a sub-vertical splay of the croda bianca reverse fault, acts as the eastern lateral release. the col delle erghene normal fault forms part of the western lateral and rear release of the landslide. other faults surrounding the landslide include the col delle tosatte fig. 2 location and context of the vajont landslide. 1 vajont landslide failure scar, 2 vajont landslide deposit, 3 vajont dam, 4 pineda landslide deposit (prehistoric failure), 5 col tramontin fault, 6 croda bianca fault, 7 col delle erghene fault, 8 massalezza stream. (modified after: wolter et al., 2014.) reverse fault and the regionally significant belluno flatramp-flat thrust system (massironi et al., 2013). 3.2. investigations on structural features and control at vajont to study the effects of the tectonic setting on failure kinematics and dynamics, engineering geological, structural geological, geophysical and geotechnical methods have been applied to the vajont landslide. for example, bistacchi et al. (2015) constructed a 3d geological model incorporating borehole, morphological, and geological data to characterise damage within the deposit as well as tectonic structures influencing the failure, and petronio et al. (2016) used p-wave, shwave, and surface wave analysis to characterise the rock masses involved in the vajont landslide. paronuzzi and bolla (2015) investigated the interaction of preexisting tectonic discontinuities with discontinuities formed due to gravitational stresses within the vajont landslide area, based on discontinuity orientation. wolter et al. (2014, 2015) used terrestrial photogrammetry, engineering geomorphological analysis and mapping, and engineering geological field investigations to characterise the vajont landslide scar and deposit. through these studies focussed on structural control, several insights have been gained. detailed morphological and structural investigations of the failure scar influenced mainly by interference patterns between the two fold generations mentioned above using methods such as photogrammetry, roughness characterisation, and block statistics, indicated smooth and rough areas of the scar, with implications for where rock bridges and concentrated damage could have formed within the sliding zone (fig. 3) (massironi et al., 2013; wolter et al., 2014). lineament mapping shows the influence of tectonic discontinuities on the geometry of the failure. the roughness of the failure scar and the locations of the col tramontin fault and massalezza syncline also explain the separation of the landslide deposit into several blocks (e.g., wolter et al., 2015). continued 142 fig. 3 roughness classes on the vajont landslide scar, based on block statistics. class 1 represents areas that are largely planar and smooth, with roughness increasing to class 4. rougher areas are more likely to have caused dilation of the failure mass over asperities and/or rock bridge failure through asperities, with implications for movement behaviour. (source: wolter et al., 2014.) wolter a. evolution of the failure scar post-1963 has focussed in a particularly active area under a fold visible in the failure scar (wolter et al., 2014). the vajont landslide deposits include areas of compression and extension, as indicated by morphological features such as transverse ridges and internal shear zones on engineering geomorphological maps (fig. 4) (wolter et al., 2015). these deformed zones suggest further separation of the landslide mass into individual blocks, and they aid in determining the movement behaviour of the catastrophic landslide. numerical modelling of the vajont landslide, including continuum, discontinuum, and hybrid simulations, has suggested that internal damage developed prior to catastrophic failure at critical locations within the rock mass, as also observed in morphological and structural geological field investigations. modelling suggests that strain concentrated within an ellipsoid of damage, 143 and certain pre-existing discontinuities likely separated the failure mass into several blocks (wolter et al., 2013; havaej et al., 2015). 4. discussion and conclusion numerous methods have been developed to analyse structural control on slope failures. the following discusses some of the caveats and limitations of methods mentioned in this paper. any data collection method must be employed with care and expert judgement, as subsequent analysis is only as good as the dataset input. for example, particularly when investigating structural features, structural domains within the study area should be considered. scale of observation is also an important consideration. structural geologists commonly examine features either at the regional or microscopic scale to determine tectonfig. 4 morphostructural features of the vajont landslide deposits, showing zones of extension and compression, as well as blocks within the deposit. (source: wolter et al., 2015.) methods used for structural control on slope instability ic history. although these scales of analysis provide context for slope-scale investigations, meso-scale features are often more significant to slope stability. in fact, slope investigations can identify previously unknown structures such as local folds and faults, as seen in the vajont landslide case above. field (and laboratory) methods remain essential in assessing rock masses and discontinuities, as well as their role in failure kinematics and dynamics. it is only through these methods that properties such as material strength can be quantified. in recent years, using smartphone applications to measure discontinuity, fold, and foliation orientation, as well as collecting other geological data, has started to displace the use of a compass. apps allow much more efficient collection of data and can reduce time spent in precarious field environments. however, their precision and accuracy have been debated (vanderlip, 2016; allmendinger et al., 2017; lee et al., 2018; nováková & pavlis, 2019), and it is still highly recommended to check the accuracy of the app chosen and to calibrate apps using a compass frequently (up to one in every 10 app measurements). understanding the theory behind the data being collected is also important to avoid poor quality or erroneous data. remote sensing applications allow data to be gathered in otherwise inaccessible areas and over large areas and have become widely used to investigate and monitor slopes. these methods require specialised knowledge and awareness of their limitations, some of which are listed in tab. 1. scaioni et al. (2014), francioni et al. (2017) and stead et al. (2019) provide further review of remote sensing as applied to unstable slopes. augmented and virtual reality techniques are relatively new to structural geology and slope investigations. they have proven to be useful tools in visualising the often multi-layered and complex datasets gathered using other methods. although not used to map or model phenomena directly yet, there are some promising developments (e.g., mysiorek et al., 2019). numerical modelling, powerful when used appropriately, should be seen as a conceptual tool to aid in understanding physical processes. like remote sensing methods, numerical methods require highly specialised knowledge. with the increased development of userfriendly interfaces, it is particularly important to have well-defined research goals, and to know the limitations of the approach used as well as the fundamental science underlying each study. stead and wolter (2015) discuss numerical modelling as applied to structural control in slopes in more detail. the incorporation of artificial intelligence (ai), particularly machine learning, into slope stability analysis is a relatively new development, and has allowed for more efficient processing of large datasets. landslide susceptibility assessment currently applies ai most frequently. studies such as dickson & perry (2016), who identify controls on coastal cliff stability using machine learning, and �uri� et al. (2019), using machine learning to classify slopes as stable, dormant or active in belgrade, nonetheless show broader applications to slope stability. for a review of machine learning methods applied to structural geology, see gunderson et al. (2019). this paper has highlighted methods applied to slope investigations, focussed on the characterisation of structural features and processes that may control slope instability. although each of the methods presented provides data and can be used to gain insight into failure mechanisms and behaviour related to structural control, studies benefit greatly from using an integrated approach, combining multiple methods. this combined approach deepens understanding and reduces uncertainty. after all, each method is simply one tool in the endeavour to comprehend complex natural processes. acknowledgements the author would like to thank the 2019 field school committee for organising an engaging excursion as well as the publication of this special issue. thanks also to the helpful comments of two reviewers and the editor. references adhikary d.p., dyskin a.v. (2007) modelling of progressive and instantaneous failures of foliated rock slopes. rock mechanics and rock engineering, 40 (4), 349-362. alfaro p., delgado j., esposito c., tortosa f.j., marmoni g.m., martino s.d. (2019) time-dependent modelling of a mountain front retreat due to a foldto-fault controlled lateral spreading. tectonophysics, 773, 228233. doi: 10.1016/j.tecto.2019.228233 agliardi f., crosta g., zanchi a. (2001) structural constraints on deep-seated slope deformation kinematics. engineering geology, 59(1-2), 83-102. agliardi f., crosta g.b., meloni f., valle c., rivolta c. (2013) structurally-controlled instability, damage and slope failure in a porphyry rock mass. tectonophysics, 605, 34-47. agliardi f., dobbs m.r., zanchetta s., vinciguerra s. (2017) folded fabric tunes rock deformation and failure mode in the upper crust. scientific reports, 7 (1), 1-9. allmendinger r.w., siron c.r., scott c.p. (2017) structural data collection with mobile devices: accuracy, redundancy, and best practices. journal of structural geology, 102, 98-112. ambrosi c., crosta g.b. (2011) valley slope influence on deformation mechanisms of rock slopes. in: jaboyedoff, m. (ed.), slope tectonics. geological society of london, london, uk, 215-233. badger t.c. (2002) fracturing within anticlines and its kinematic control on slope stability. environmental and engineering geoscience, 8(1), 19-33. bistacchi a., massironi m., francese r., giorgi m., taller c. (2015) the 3d geological model of the 1963 vajont rockslide, reconstructed with implicit surface methods. geophysical research abstracts, vol. 17, egu2015-15743. bonilla-sierra v., scholtès l., donzé f.v., elmouttie m. (2015) dem analysis of rock bridges and the contribution to rock slope stability in the case of translational sliding failures. international journal of rock mechanics and mining sciences, 80, 67-78. 144 wolter a. grandfather mountain window-linville falls shear zone contact, southern appalachian mountains, watauga county, north carolina. in 43rd us rock mechanics sympo-sium & 4th us-canada rock mechanics symposium 28 june 1 july 2009 (p. 13), 181, asheville. glastonbury j., fell r. (2000) report on the analysis of “rapid” natural rock slope failures. university of new south wales. school of civil and environmental engineering report no. r390, pp. 154. glueer f., loew s., manconi a. (2019a) paraglacial history and structure of the moosfluh landslide (1850-2016), switzerland. geomorphology, 355, 106677. doi: 10.1016/j.geomorph.2019.02.021 glueer f., loew s., manconi a., aaron j. (2019b) from toppling to sliding: progressive evolution of the moosfluh landslide, switzerland. journal of geophysical research: earth surface, 124(12), 2899-2919. gschwind s., loew s., wolter a. (2019) multi-stage structural and kinematic analysis of a retrogressive rock slope instability complex (preonzo, switzerland) engineering geology, 252, 27-42. guerin a., jaboyedoff m., collins b.d., derron m.h., stock g.m., matasci b., boesiger m., lefeuvre c., podladchikov y.y. (2019) detection of rock bridges by infrared thermal imaging and modeling. scientific reports, 9(1), 1-19. gunderson k.l., zhang z., cheng s. (2019) machine learning applications to structural geology: philosophy, progress, and pitfalls. geological society of america annual meeting, paper no. 143-14, pp. 14. guo q., pan j., cai m., zhang y. (2020) investigating the effect of rock bridge on the stability of locked section slopes by the direct shear test and acoustic emission technique. sensors (basel, switzerland), 20(3), 638. doi: 10.3390/s20030638 havaej m., wolter a., stead d. (2015) the possible role of brittle rock fracture in the 1963 vajont slide, italy. international journal of rock mechanics and mining sciences, 78, 319-330. havaej m., stead d. (2016) investigating the role of kinematics and damage in the failure of rock slopes. computers and geotechnics, 78, 181-193. henderson i.h.c., lauknes t.r., osmundsen p.t., dehls j., larsen y., redfield t. f. (2011) a structural, geomorphological and insar study of an active rock slope failure development. geological society, london, special publications, 351(1), 185199. hendron a.j., patton f.d. (1985) the vaiont slide: a geotechnical analysis based on the new geologic observations of the failure surface: technical report gl-85-5, pp. 259. hoek e., hutchinson j., kalenchuk k., diederichs m. (2009) appendix 3: influence of in situ stresses on open pit design. in: read, j., stacey, p. (eds.), guidelines for open pit slope design. csiro publishing, collingwood, australia, 437-445. humair f., pedrazzini a., epard j.-l., froese c.r., braathen a., blikra l.h., berg s.s., karlsen f. (2004) rock-slope failures in norway; type, geometry, deformation mechanisms and stability. norwegian journal of geology/norsk geologisk forening, 84 (1), 67-88. brideau m.a., stead d. (2010) controls on block toppling using a three-dimensional distinct element approach. rock mechanics and rock engineering, 43(3), 241-260. chávez c., equihua l.n., domínguez f. (2017) stability fem analysis of rock masses modeling pattern of joints. in complas xiv: proceedings of the xiv international conference on computational plasticity: fundamentals and applications cimne, 646655. cody e., draebing d., mccoll s., cook s., brideau m. a. (2019) geomorphology and geological controls of an active paraglacial rockslide in the new zealand southern alps. landslides, 1-22. corkum a.g., martin c.d. (2004) analysis of a rock slide stabilized with a toe-berm: a case study in british columbia, canada. international journal of rock mechanics and mining sciences, 41(7), 1109 -1121. dickson m.e., perry g.l. (2016) identifying the controls on coastal cliff landslides using machine-learning approaches. environmental modelling and software, 76, 117-127. donati d., stead d., elmo d., borgatti l. (2019) a preliminary investigation on the role of brittle fracture in the kinematics of the 2014 san leo landslide. geosciences, 9, 256, pp. 31. dufresne a., davies t.r. (2009) longitudinal ridges in mass movement deposits. geomorphology, 105(34), 171-181. �uri� u., marjanovic m., radi� z., abolmasov b. (2019) machine learning based landslide assessment of the belgrade metropolitan area: pixel resolution effects and a cross-scaling concept. engineering geology, 256, 23-38. elmo d., donati d., stead d. (2018) challenges in the characterisation of intact rock bridges in rock slopes. engineering geology, 245, 81-96. francioni m., salvini r.l., stead d., coggan j. (2017) improvements in the integration of remote sensing and rock slope modelling. natural hazards, 90, 975 -1004. ganerød g.v., grøneng g., rønning j.s., dalsegg e., elvebakk h., tønnesen j.f., kveldsvik v., eiken t., blikra l.h., braathen a. (2008) geological model of the åknes rockslide, western norway. engineering geology, 102, 1-18. genevois r., ghirotti m. (2005) the 1963 vaiont landslide. giornale di geologia applicata 1, 41-52. genevois r., tecca p.r. (2013) the vajont landslide: state-of-the-art. italian journal of engineering geology and environment book series (6), 15-39. gillon k.a., wooten r.m., latham r.l., witt a.w., douglas t.j., bauer j.b., fuemmeler s.j. (2009) integrating gis-based geologic mapping, lidarbased lineament analysis and site specific rock slope data to delineate a zone of existing and potential rock slope instability located along the 145 methods used for structural control on slope instability jaboyedoff m. (2013) structural characterization of turtle mountain anticline (alberta, canada) and impact on rock slope failure. tectonophysics 605, 133-148. jaboyedoff m., oppikofer t., derron m.h., blikra l.h., böhme m., saintot a. (2011) complex landslide behaviour and structural control: a threedimensional conceptual model of åknes rockslide, norway. geological society, london, special publications, 351(1), 147-161. kromer r.a., hutchinson d.j., lato m.j., gauthier d., edwards t. (2015) identifying rock slope failure precursors using lidar for transportation corridor hazard management. engineering geology, 195, 93-103. lee s., suh j., choi y. (2018) review of smartphone applications for geoscience: current status, limitations, and future perspectives. earth science informatics, 11, 463-486. loew s., gischig v., willenberg h., alpiger a., moore j. r. (2012) 24 randa: kinematics and driving mechanisms of a large complex rockslide. in: clague j.j., stead d. (eds.), landslides: types, mechanisms and modeling, cambridge university press, 297-309. manconi a., loew s., glueer f. (2019) insights on rock mass disintegration at the moosfluh slope, switzerland. in geophysical research abstracts (vol. 21). massironi m., zampieri d., superchi l., bistacchi a., ravagnan r., bergamo a., genevois m. (2013) geological structures of the vajont landslide. italian journal of engineering geology and environment, 2013(6), 573-582. mathiesen d., myers t., atkinson i., trevathan j. (2012) geological visualisation with augmented reality. in 2012 15th international conference on networkbased information systems (172-179) ieee. doi: 10.1109/nbis.2012.199 milmo p., rogers s., raynor m., beale g. (2014) appendix 3: case study: diavik north-west wall. in: read, j., beale, g. (eds.), guidelines for evaluating water in pit slope stability. csiro publishing, collingwood, 436-485. mineo s., calcaterra d., zampelli s.p., pappalardo g. (2015) application of infrared thermography for the survey of intensely jointed rock slopes. rendiconti online societa geologica italiana, 35, 212215. mysiorek j., onsel i.e., stead d., rosser n. (2019) engineering geological characterization of the 2014 jure nepal landslide: an integrated field, remote sensing-virtual/mixed reality approach. in 53rd us rock mechanics/geomechanics symposium. american rock mechanics association, pp. 12. nováková l., pavlis t.l. (2019) modern methods in structural geology of twenty-first century: digital mapping and digital devices for the field geology. in: teaching methodologies in structural geology and tectonics, springer, singapore, 43-54. paronuzzi p., bolla a. (2012) the prehistoric vajont rockslide: an updated geological model. geomorphology, 169, 165-191. paronuzzi p., bolla a. (2015) gravity-induced fracturing in large rockslides: possible evidence from vajont. in: engineering geology for society and territory-volume 2, springer, cham, 213-216. perrone a., lapenna v., piscitelli s. (2014) electrical resistivity tomography technique for landslide investigation: a review. earth-science reviews, 135, 65-82. petronio l., boaga j., cassiani g. (2016) characterization of the vajont landslide (north-eastern italy) by means of reflection and surface wave seismics. journal of applied geophysics, 128, 58-67. ravagnan r. (2011) evidence of dinaric tectonic in the vajont area and consequences on the local geological and hydrogeological structure. bsc thesis, universita degli studi di padova, padova, italy, pp. 117. scaioni m., longoni l., melillo v., papini m. (2014) remote sensing for landslide investigations: an overview of recent achievements and perspectives. remote sensing, 6, 9600-9652. semenza e. (2010) the story of vaiont told by the geologist who discovered the landslide. translation by carolyn goodman masè of semenza (2001). kflash, ferrara, pp. 208. shea t., vries b.v. (2008) structural analysis and analogue modeling of the kinematics and dynamics of rockslide avalanches. geosphere, 4(4), 657-686. singeisen c., ivy-ochs s., wolter a., steinemann o., akçar n., yesilyurt s., vockenhuber c. (2020) the kandersteg rock avalanche (switzerland): integrated analysis of a late holocene catastrophic event. landslides, 1-21. stead d., donati d., wolter a., sturzenegger m. (2019) application of remote sensing to the investigation of rock slopes: experience gained and lessons learned. isprs international journal of geoinformation, 8(7), 296, pp. 24. stead d., eberhardt e. (2013) understanding the mechanics of large landslides. invited keynote and paper. italian journal of engineering geology and environment, book ser. 6, 85-112. stead d., eberhardt e., coggan j.s. (2006) developments in the characterization of complex rock slope deformation and failure using numerical modelling techniques. engineering geology, 83, 217-235. stead d., wolter a. (2015) a critical review of rock slope failure mechanisms: the importance of structural geology. journal of structural geology, 74, 123. sturzenegger m., stead d. (2012) the palliser rockslide, canadian rocky mountains: characterization and modeling of a stepped failure surface. geomorphology, 138(1), 145-161. superchi l., floris m., ghirotti m., genevois r., jaboyedoff m., stead d. (2010) technical note: implementation of a geodatabase of published and unpublished data on the catastrophic vaiont landslide. natural hazards and earth system sciences, 10(4), 865-873. vanderlip c. (2016) structural geology with a mobile 146 wolter a. 147 phone?: testing smartphone apps for strike and dip. geological society of america, south-central section: 50th annual meeting, paper no. 15-10. vick l.m., böhme m., rouyet l., bergh s.g., corner g.d., lauknes t.r. (2020) structurally controlled rock slope deformation in northern norway. landslides, 1-32. wasowski j., pisano l. (2019) long-term insar, borehole inclinometer, and rainfall records provide insight into the mechanism and activity patterns of an extremely slow urbanized landslide. landslides, 17, 445-457. wolter a., havaej m., zorzi l., stead d., clague j.j., ghirotti m., genevois r. (2013) exploration of the kinematics of the 1963 vajont slide, italy, using a numerical modelling toolbox. italian journal of engineering geology and environment, 6, 599-612. wolter a., stead d., clague j.j. (2014) a morphologic characterisation of the 1963 vajont slide, italy, using long-range terrestrial photogrammetry. geomorphology, 206, 147-164. wolter a., stead d., ward b., clague j.j., ghirotti m. (2015) engineering geomorphological characterisation of the vajont slide, italy, and a new interpretation of the chronology and evolution of the landslide. landslides, 13, 1067-1081. yuskar y., putra d.b.e., suryadi a., choanji t., cahyaningsih c. (2017) structural geology analysis in a disaster-prone of slope failure, merangin village, kuok district, kampar regency, riau province. journal of geoscience, engineering, environment, and technology, 2(4), 249-254. methods used for structural control on slope instability ms. received: may 5, 2020 revised: july 30, 2020 accepted: august 1, 2020 available online: november 30, 2020 148 microsoft word 11_pini_lm03.doc available online http:/amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 26 (1), 2013, vii-ix report on the icdp workshop dove “drilling overdeepened alpine valleys” (como and valtellina, 3-5 april 2013) roberta pini cnr istituto per la dinamica dei processi ambientali, laboratorio di palinologia e paleoecologia, milano, italy corresponding author : roberta pini <roberta.pini@idpa.cnr.it> http://palinologia.disat.unimib.it abstract: here i provide a short report on the icdp-funded workshop dove (drilling overdeepened alpine valleys), held in como and valtellina between 3-5 april 2013. discussion, led by the project principal investigators, aimed at defining the scientifical issues and the financial budget of a multinational drilling initiative in and across the alps. keywords: icdp, dove, overdeepened alpine valleys. on 3-4 april 2013 the icdp workshop dove "drilling overdeepened alpine valleys" was held in the scenic villa del grumello, on the south-western shore of lake como (northern italy). icdp is the acronym for the international continental scientific drilling program; it is a transnational program based at the gfz german research centre for geosciences, aiming at promoting, funding and coordinating continental scientific drillings with relevant scientific objectives of global significance (fig. 1). icdp supports researches focused on climate dynamics and global environment, life history, natural resources and a wide range of geologically-relevant topics like active faults and earthquakes, volcanoes, hot spots, plate collision and impact structures. project proposals may be submitted to icdp once a year by scientists from member and non-member countries looking for logistical and financial support to continental drillings. the dove workshop (fig. 2), funded by icdp, fig. 1 drilling operations at lake ohrid (macedonia, albania) in the framework of the icdp-funded project scopsco "scientific collaboration on past speciation conditions in ohrid" (photo www.icdp-online.org). pini r. viii joined experts in drilling and core-logging techniques, geochronology, geophysics, glacier modelling, natural hazards and nuclear waste, sedimentology, stratigraphy and structural geology to define the scientific and economic agenda of a multinational drilling initiative across the alpine chain. the dove project aims at exploring nature, geometry and age of sedimentary successions filling overdeepened alpine valleys, to answer to key questions related to rates and processes shaping alpine landscapes and their forelands. special attention will be paid to the effects of multiple glaciations on mountain areas, to reconstruct their timing and extent and decipher regional differences, and to the history of biodiversity and the impact of glaciations on original ecosystems of the alps. the potential of the study areas for ground-water and geothermal resources and as nuclear waste and gas disposal sites will be carefully evaluated. the meeting, organized by cnr idpa milano, was attended by 46 professors, researchers, phd students and professionals representing 9 european nations (austria, denmark, germany, france, italy, slovenia, sweden, switzerland, the netherlands) and usa (fig. 3). the workshop opened with a note by dr. ulrich harms, icdp executive secretary, describing icdp organization, activities, funding strategies and criteria for project selection and evaluation. criteria applied for evaluation are the project's global significance, the pooling of resources and technologies by a broad scientific international team, the societal relevance of the problem, the necessity for drilling and the balance of costs and drilling design. the workshop scientific activity developed through two days of plenary sessions and working groups discussions focusing on pre-site surveys, methods, goals, active and future collaborations and potential drilling sites in austria, germany, italy, slovenia, switzerland. drilling techniques will be carefully evaluated, given the expected core lenghts (up to several hundred meters, from the ground level possibly down to bedrock) and the need to have sufficient amounts of sediment for several destructive analysis (and therefore smaller core diameters should be avoided). on april 5 workshop participants were involved in a one-day fieldtrip to a potential drilling site in the nearby overdeepened valtellina area. despite adverse weather conditions preventing any clear view from the panoramic point towards the valley floor, participants were offered a comprehensive sketch on geological investigations carried out in recent years in this area by regione lombardia and cnr-idpa, consisting of two long cores (teglio and sondalo) drilled in the frame of the new geological map of lombardy and seismic profiles. the excursion ended with the visit to the local drilling company storing the 208 mlong teglio core observing, describing and discussing sediment features and their meaning. the workshop participants agreed to endorse the effort of submitting a full proposal for the dove project to icdp by january 2014. a group of principal investigators, namely prof. flavio anselmetti (univ. of bern), dr. milos bavec (geological survey of slovenia), dr. gerald gabriel (leibnitz institute for applied geophysics in hannover), prof. frank preusser (univ. of stockholm), dr. cesare ravazzi (consiglio nazionale delle ricerche milano) and dr. jürgen reitner (geological survey of austria), will be in charge of it. the success of fig. 2 the logo of the icdp dove project (design by c. ravazzi, cnr-idpa milano). icdp dove workshop ix the project relies on the interest and support by research agencies, universities, local and regional administrations, industry groups. indeed, in case of positive evaluation, icdp funds will be granted for project and drilling development, while applicants are asked to raise additional resources to fully cover drilling costs, facilities, scientific data production and management. more informations on icdp and its activity can be found at www.icdp-online.org. those interested in joining the dove adventure, promoting deep drillings and sharing their social and scientific outcomes, can contact dr. cesare ravazzi at cnr idpa (cesare.ravazzi@idpa.cnr.it). ms. received: may 10, 2013 final text received: may 14, 2013 fig. 3 group photo of the participants to the icdp dove workshop (photo courtesy markus fiebig). << /ascii85encodepages false /allowtransparency false /autopositionepsfiles 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documenti pdf creati possono essere aperti con acrobat e adobe reader 5.0 e versioni successive.) /enu (use these settings to create adobe pdf documents suitable for reliable viewing and printing of business documents. created pdf documents can be opened with acrobat and adobe reader 5.0 and later.) >> >> setdistillerparams << /hwresolution [1200 1200] /pagesize [396.850 566.929] >> setpagedevice microsoft word 00_indice_lm04.docx il quaternario it issn 039-3356 italian journal of quaternary sciences 24 (1), 2011 41-50 the palaeontological campaigns of alberto malatesta in the mediterranean islands odoardo girotti1, tassos kotsakis2 & carmelo petronio1 1 dipartimento di scienze della terra, università di roma sapienza, roma 2 dipartimento di scienze geologiche e centro di ecologia evolutiva, università di roma tre, roma corresponding author: t. kotsakis <kotsakis@uniroma3.it> abstract: girotti o., kotsakis t. & petronio c., palaeontological campaigns of alberto malatesta in the mediterranean islands. a short account of the palaeontological campaigns organized and led by alberto malatesta in the mediterranean islands, in search of quaternary endemic vertebrates, is presented in this paper. the activity of malatesta in such a field can be grouped in four periods. the first period (1964-1970) deals with his researches in sardinia (dragonara cave, nettuno cave, capo figari); the second one (19701972) includes the field campaigns in crete (simonelli cave and katharo plateau); the third period (1972-1978) regards the researches in sicily (capo tindari cave); during the last period (1979-1984) the scientific interests of malatesta returned back to sardinia (is oreris quarry, alghero neighbours). for each locality, a brief exposition of the principal results is presented together with a summary of the research and revision papers that malatesta and his co-workers wrote on the material collected during the field seasons. riassunto: girotti o., kotsakis t. & petronio c., campagne paleontologiche di alberto malatesta nelle isole del mediterraneo. in questo lavoro viene presentata una breve sintesi delle campagne paleontologiche nelle isole del mediterraneo organizzate e dirette da alberto malatesta, in cerca di giacimenti di vertebrati endemici del quaternario. l’attività di malatesta in questo campo è divisa in quattro periodi. durante il primo periodo (1964-1970) i suoi interessi sono concentrati sulle faune insulari della sardegna (grotta di dragonara, grotta di nettuno, capo figari). il secondo periodo (1970-1972) comprende le tre spedizioni all’isola di creta (grotta simonelli, altipiano di katharo). il terzo periodo (1972-1978) vede gli interessi di malatesta spostarsi verso la sicilia (grotta di capo tindari). infine durante il quarto periodo (1979-1984) si ritorna a ricerche in sardegna (cava di is oreris, dintorni di alghero). per ogni località esplorata vengono date sommarie notizie circa i risultati ottenuti e vengono riportati i lavori che illustrano queste faune, sia quelli di malatesta e dei suoi collaboratori, sia quelli di revisione o ampliamento di studi, fatti su materiale raccolto durante questi scavi. key words: biography, palaeontological campaigns. parole-chiave: biografia, campagne di scavi paleontologici. 1. introduction the quarter of the xx century that went from the beginning of the sixties till the half of the eighties was particularly fruitful for the palaeontological researches of the then-institute of geology and palaeontology of the university of rome (included in the last years of that period in the department of earth sciences). the most important character of that period was not only a considerable increase in the number of publications (during the years that followed, the publications were even more numerous), but especially a large increase of the collected fossil material. this was true for all fields of palaeontology (microfossils, invertebrates and vertebrates), but the sector that presented, at least macroscopically, the most spectacular results, was the field of vertebrates. this situation is clearly evidenced by the large number of skeletons of fossil vertebrates that were mounted in the museum of palaeontology during those years. the start of the campaigns for the collection of vertebrate fossils was given by angiola maria maccagno in the fifties, but further development was due to a combination of factors including the presence of bruno accordi as the director of the institute (and of the museum of palaeontology) from 1959 and of alberto malatesta as the professor of palaeontology since 1963. the two men differed in many things but certainly shared the interest on the island vertebrate fossils. for accordi the years at the university of catania, the study of the endemic hippo of sicily (hippopotamus pentlandi von meyer), and the discovery of the cave of spinagallo (accordi, 1955; accordi & colacicchi, 1962) led to an increasing interest on the problems of insular gigantism and dwarfism. for malatesta similar opportunities were the geological surveys for several geological maps of both sicily and sardinia (during his employment at the italian geological survey); in fact they gave him the possibility to identify fossil deposits of endemic island faunas and to direct its scientific interest to this field. so, what characterized the activity of a. malatesta during this period were the palaeontological campaigns in the mediterranean islands to collect endemic quaternary vertebrates and these activities will be discussed in more detail. the scientific activities of alberto malatesta were not limited to the palaeontological campaigns we are going to expose. many of his work was devoted to the o. girotti, t. kotsakis & c. petronio 42 study of the stratigraphy of various localities of the italian peninsula and to the systematic study of vertebrates and especially molluscs collected in several sites. malatesta, assisted by odoardo girotti and giuseppe sirna, started, since 1964, to collect marine molluscs from the pliocene clayey deposits of umbria, along the rivers chiani, paglia and tiber. the collection went on for short intervals during the following years. the systematic results were published in 1974 in a huge volume (malatesta, 1974). malatesta worked on the stratigraphy and on the fossil faunas of grotta della madonna at praia a mare (calabria), torre in pietra (latium), and of several other areas of latium. during these studies he collaborated with lucia caloi, luigi cardini, piero cassoli, vittorio conato, daniela esu, elsa gliozzi, maria rita palombo, and, especially in the last years of his activities, with francesco zarlenga (malatesta, 1978a; conato et al., 1980; malatesta & zarlenga, 1986, 1988). in september-october 1980 malatesta and zarlenga led a campaign to collect paleocene molluscs in the basin of rio massintonto (maputo), with the financial support of the compagnia bonifica. the rich mollusc fauna, containing a large number of new taxa, was described by malatesta & gliozzi (1983). 2. sardinia: dragonara cave, nettuno cave, capo figari (1964-1970) returning to our main topic, the island campaigns, it should be noted that malatesta had already collected fossil material from the dragonara cave (porto conte, sardinia) and some other localities of the area during the first half of the fifties (malatesta & settepassi, 1954), and in 1962 he published the first work on the endemic canid of sardinia, without giving a precise indication of the fossiliferous locality, since the site was object of a preliminary collection only, and new campaigns were planned (malatesta, 1962). the first of the campaigns at dragonara was organized in the summer of 1964. the team was composed by pierluigi ambrosetti, odoardo girotti, valerio palmerini, giuseppe sirna, and a. malatesta as the leader (fig. 1). the dragonara cave opens to about one meter a.s.l. and is accessible only by sea. the investigating team was camped about 200 m from the cave and reached the site using a boat or, sometimes, swimming. the three weeks of work were particularly successful and notable quantities of material were collected. however, the cave was still full of fossils, and malatesta planned two additional campaigns. the second campaign (lasted two weeks) was held in the spring of 1969 with the participation of carmelo petronio, valentino pettinella and giuseppe sirna (figs. 2, 3) and increased the fossil material already collected. the third one was organized in the spring of 1970 and lasted three weeks. that time, under the leadership of a. malatesta, c. petronio, v. pettinella, claudio romei and others were the members of the team. the material collected after the first two campaigns was considered sufficient by malatesta (1970) to complete a monograph on cynotherium sardoum, the sardinian endemic canid, on which, as we have seen, he devoted a preliminary note. on the contrary, to describe the endemic deer praemegaceros cazioti (depéret), the specimens collected during the third expedition were also fig. 1 summer 1964: group photo at the end of the campaign at the dragonara cave (sardinia). from left: v. palmerini, p. ambrosetti, a. malatesta, o. girotti, and g. sirna. estate 1964: foto di gruppo al termine della campagna di scavo alla grotta di dragonara (sardegna). da sinistra: v. palmerini, p. ambrosetti, a. malatesta, o. girotti e g. sirna. the palaeontological campaigns of alberto malatesta in the mediterranean islands 43 fig. 2 spring 1969: a moment of rest during the excavation at the dragonara cave (sardinia). from left: a. malatesta, c. petronio, g. sirna., and v. pettinella. primavera 1969: un momento di riposo durante lo scavo: della grotta di dragonara (sardegna). da sinistra: a. malatesta, c. petronio, g. sirna., e v. pettinella. fig. 3 spring 1969: c. petronio (from back) and a. malatesta look at the excavation within the dragonara cave (sardinia). c. petronio (di spalle) e a. malatesta osservano lo scavo all’interno della grotta di dragonara (sardegna). considered (caloi & malatesta, 1974). the fossil remains of the deer were further studied under several morphological-functional aspects from caloi & palombo (1991, 1995) and palombo (2005) and the data obtained from this “population” were used for studies and for models involving adaptive changes in the morphology of the island endemic deer. the “hunterschreger bands” of the canid of dragonara were also object of a study (novelli & palombo, 2007). besides the two large mammals (the canid and the cervid) a small carnivore, four species of small mammals, many species of birds and some species of amphibians and reptiles were discovered at dragonara. the small mammals have never been studied in an analytical way (there is only a master thesis). a partial study of the teeth of the arvicolid microtus (tyrrhenicola) henseli (major) was published by minieri et al. (1995). for birds malatesta & suriano (1971) provided a list of species, while the fossil herpetofauna was studied by kotsakis (1980a). the remains of a small carnivore, a lutrine, proved to be of particular interest; despite their paucity, they have allowed to establish a new endemic sardinian species (malatesta, 1978b), some years later transferred (willemsen & malatesta, 1986) to an endemic genus, algarolutra majori (malatesta). gliozzi (1985) studied some postcranial remains of this species. the dragonara assemblage is at present considered representative of the late pleistocene “classical” sardinian fauna: in her biochronological chart of fossil mammal assemblages of sardinia, palombo (2006) has proposed the dragonara faunal sub-complex of the microtus (tyrrhenicola) complex, corresponding to the latest middle pleistocene earliest holocene time span. o. girotti, t. kotsakis & c. petronio 44 between the first and the second campaigns of dragonara, in the early months of 1966, malatesta and piero cassoli, invited in sardinia by the tourist office of alghero to visit some caves, had the chance to see an otter skull collected by some speleologists in the cave of nettuno (near capo caccia). malatesta, informed of the presence of the entire skeleton, organized a miniexpedition during the month of september of that year and, accompanied by some local speleologists (p. bradis, g. pala), reached the tunnel patrizi where a complete skeleton of the lutrine laid, partly outcropping on the sand and partly buried in it, at about 4 m a.s.l. (fig. 4). despite the narrowness of the tunnel, it was possible to collect all the bones of the entire skeleton, which remained not studied for a long time. the description of the species was made by malatesta in 1977, when he established the endemic species nesolutra ichnusae malatesta, whose age should be holocene. this lutrine clearly lived in the sea and presumably had similar habits to the recent north pacific sea otter, enhydra lutris (linnaeus). malatesta came to this conclusion observing the penial bone (obviously the skeleton belonged to a male). several years later, willemsen (1992) carried on a review of the plio-quaternary lutrini of europe and established a new endemic genus for the sardinian sea otter, sardolutra ichnusae (malatesta). angelelli (1995) carried out a study of the morphology of the endocranial cast of this species. during the expedition of 1970, after the end of the excavation of dragonara, the collection of fossil material from a breccia of capo figari, was also organized. the site was known for the excavations carried out there by c. i. forsyth major (between the end of the nineteenth century and the beginning of the twentieth century) and by e. g. déhaut who identified a fossil antelope and other mammals. the british palaeontologist did not publish the results of his researches (he just mentioned the presence of a fossil monkey). malatesta, who had previously visited the place and identified a fossiliferous site he believed (probably correctly) to be the site excavated by déhaut, organized the collection of samples form a very hard breccia. he rewarded, at least in part, of his expectations, after the fossils were prepared in the laboratory in rome. also if he failed to recover any fossil remain of the monkey, as he hoped, he instead managed to get some important remains of the antelope. the material studied by gliozzi & malatesta (1980) allowed establishing a new genus for the antelope, nesogoral melonii (déhaut). a second publication described the endocranial morphology of this ruminant (angelelli et al., 1982). compared to the fauna of dragonara, the fauna of capo figari is much older. the generic name of the antelope has been used by palombo (2006) to indicate the older of the two faunal complexes proposed for the plio-pleistocene faunas of sardinia: nesogoral faunal complex consisting of two sub-complexes. the most recent of these is called capo figari / orosei 1 sub-complex, roughly corresponding to the early pleistocene. according to a communication of malatesta to one of the authors of this paper (t.k.), during the sixties malatesta visited also the island of tavolara (north-eastern sardinia) and collected some subfossil remains of birds (?puffinus). no organized campaigns of excavation at tavolara appear to have been organised and, probably, the bird material was collected during a short visit of malatesta alone. 3. crete: simonelli cave and katharo (1970-1972) in the same year of the campaign at dragonara and capo figari, bruno accordi managed to achieve considerable funding from the accademia nazionale dei lincei for excavations focused on the collection of fossil insular endemic vertebrates. he then asked malatesta about the possibility of organizing an excavation at crete, an island whose quaternary endemic mammals were partly known through the papers (late xix early xx centuries) of dorothy bate and vittorio simonelli. about that time (late sixties-early seventies) the data on these mammalian faunas were increased through the work of siegfried kuss and paul sondaar. a. malatesta (fig. 5), fig. 5 september 1970: a. malatesta at iraklion (crete). settembre 1970: a. malatesta ad iraklion (creta). the palaeontological campaigns of alberto malatesta in the mediterranean islands 45 o. girotti and g. sirna embarked on an “exploring expedition” to identify possible fossiliferous sites to excavate. attention was focused on the caves along the cliffs on the northern coast, west of the city of rethymno. after several attempts, the group was able to find a cave that seemed to promise a large amount of fossil remains, just west of rethymno barracks, then to west end of the town. during the winter 1971 contacts were made for a collaboration with prof. yannis melentis of the university of thessaloniki. the expedition set off during september of that year, was led by alberto malatesta and comprised, among the italian members antonello angelucci, giacomo civitelli, o. girotti, t. kotsakis, v. pettinella, a. praturlon, c. romei and g. sirna, and among the greek members y. melentis, d. mountrakis and g. soulios. later on also b. accordi joined the excavations. the intuition of the “exploring expedition” proved to be correct. the cave contained an enormous amount of material of late pleistocene age. the vast majority of the remains belonged to a small deer. the cave, which was named “grotta simonelli” in honor of the italian palaeontologist of the beginning of the xx century who had first described the remains of the little endemic deer, was not easily accessible by land and the transport of the collected material was done with mules. the excavation lasted five weeks. during this period a. malatesta, with o. girotti and, in turn, with another member of the expedition, visited some other fossiliferous sites known from the geological literature. in particular he visited for five days (with girotti and kotsakis) the katharo plateau (in the eastern part of the island) where boekschoten & sondaar (1966) had reported the remains of a dwarf hippopotamus (fig. 6). rather fragmentary fossil remains were scattered over a large surface area of this ancient lacustrine basin. a few days later, while the excavations at “grotta simonelli” continued, malatesta, girotti and kotsakis visited the island of cyprus. thanks to m. mantis of the geological survey of cyprus they visited some “classic” places discovered by miss bate. but apart from the collection of some small samples, this “exploring expedition” was not followed by any larger campaign. preliminary results of the cretan expedition were published by accordi (1972) and melentis (1974). the restoration of the material lasted for a long time. the analytical study of the cervid praemegaceros cretensis (simonelli) was published by malatesta (1980) and was supplemented by several other minor notes on the rest of the fauna, elephants, carnivores (subfossils), birds, reptiles and the study of the endocranial morphology of the endemic deer (angelelli, 1980; caloi, 1980; kotsakis, 1980b; mangilli, 1980; suriano, 1980). again, like the fossils of the dragonara cave, the simonelli cave findings offered the possibility of additional studies on several aspects of the adaptations of the endemic mammals (palombo & petronio, 1989; caloi & palombo, 1996; palombo et al., 2008). the expedition of 1971 had an epilogue in the next year. malatesta led a further expedition in september 1972, with the participation of t. kotsakis, c. petronio and v. pettinella (fig. 7). the expedi o. girotti, t. kotsakis & c. petronio 46 fig. 8 september 1972: katharo plateau. dried streamlet showing lacustrine clayey marls overlain by debris flow. v. pettinella indicates the outcrop with bones. settembre 1972: altipiano di katharo (creta). letto asciutto di un torrente in cui affiorano le marne argillose sovrastate da depositi di debris flow. v. pettinella indica il punto dell’affioramento fossilifero. tion lasted three weeks, two of which were spent on the katharo plateau. during this field work, some remains of the endemic ?middle pleistocene hippo of crete, hippopotamus creutzburgi boekschoten & sondaar, were recovered (figs. 8, 9); they were described ten years later fig. 9 a detail of the outcrop of fig. 8 with fossil hippo remains. un dettaglio dell’affioramento illustrato in fig. 8 con i resti fossili di ippopotamo. by capasso barbato et al. (1982) and reviewed in a morphological-functional perspective by caloi & palombo (1996). two of the authors of these pages recall a typical scene that took place in a good hotel in aghios nikolaos, which we entered soon after our descent from katharo (where we stayed for a fortnight in a tent, obviously free camping). the smell around us should not have been the most pleasant, because we saw the reception employees that we watched with vigilant eyes, with a sense of annoyance and almost hostility. but when they heard our cries to malatesta: “professore! professore!”, their sights changed and one said to the others: a! αρχαιολογοι! and smiled again! the research group of palaeontologists of the roma university, again in collaboration with the university of thessaloniki, carried on other expeditions in crete in later years, (kotsakis et al., 1976), but a. malatesta did not join them. 4. sicily: capo tindari (1972-1978) during the field work in sicily’s northern coast around capo tindari, malatesta (1958) reported for the first time the presence of a cave filled with abundant fossils, known locally as the “grotta della fata donnavilla”. the cavity opens along the cliffs of capo tindari at a height of 76 m a.s.l. the access was very difficult and the palaeontological campaigns of alberto malatesta in the mediterranean islands 47 the cave could be reached only by walking on a small edge protruding from the rock that was even broken partially in some points. the material collected during the fifties was increased in two expeditions conducted in 1973 and 1974 respectively. c. petronio, v. pettinella and c. romei took part to the first, while in the second one malatesta was accompanied only by c. romei. during this last field excursion (rather than expedition) various places in the provinces of enna and caltanissetta were visited in search of sites with lower paleolithic industry. however, these searches were fruitless. the last campaign to capo tindari dates back to 1978. in addition to malatesta, who led the group, francesco angelelli, l. caloi, t. kotsakis, m.r. palombo, c. petronio, v. pettinella and c. romei were present. during this final expedition, which dedicated to capo tindari a week of work, the collection of deer remains was increased and some rare remains of hippo were found (fig. 10). in the unconsolidated superficial fraction of the sediment some small mammal remains were collected. just during the last day of the excavation, a serious accident happened, with the risk that some staff member fell down the cliff (that was 76 m height). fortunately, the intervention of v. pettinella and c. romei prevented the successful scientific trip to end in a tragedy. the material collected belonged to two deers, the endemic sicilian hippopotamus hippopotamus pentlandi, and a small bear, ursus sp. a preliminary communication on the fossils collected fig. 10 settembre 1978: l. caloi (on the left) and a. malatesta look at a fossil bone fragment collected during the excavation of the tindari cave (sicily). on the right, m.r. palombo is moving out of the picture settembre 1978: l caloi (a sinistra) e a. malatesta osservano un frammento di osso fossile raccolto durante lo scavo della grotta di tindari (sicilia). a destra, m.r. palombo sta uscendo dalla foto. in the fifties was made by caloi (1973) who described some remains of deer and hippo. a detailed description of one species of deer was published by gliozzi & malatesta (1982) who attributed the majority of the cervid remains collected in cave of capo tindari to praemegaceros (notomegaceros) carburangelensis (de gregorio) a form of endemic sicilian megacerine, for which a new endemic subgenus was proposed. in an appendix to this work caloi & palombo (1982) illustrated the few remains of endemic hippopotamus. the remains of the second deer, an endemic sicilian subspecies of the red deer, cervus elaphus siciliae pohlig, of latest middle pleistocene to late pleistocene age, were described together with all the remains belonging to this form by gliozzi et al. (1993). the first species of deer is now ascribed to dama carburangelensis (de gregorio) by abbazzi et al. (2001). 5. sardinia again (1979-1984) in the second half of may 1979, malatesta organized an “exploring expedition” with t. kotsakis in sardinia, which lasted two weeks. a special feature of this expedition was the fact that they moved always by train and on foot. the first result of the expedition was the identification of a rich accumulation of small vertebrate bones in the alabaster quarry, an abandoned part of the mine of santa lucia in is oreris (iglesiente, swsardinia). the site was already known in the palaeontological literature for the discovery of a skull of the endemic sardinian monkey, macaca majori azzaroli, by comaschi caria (1970). the second fossiliferous locality object of this visit was a cavity discovered by malatesta in the early ’50s to the south of alghero between punta padrebellu and omo morto. malatesta remembered a footpath leading to the south of the city of alghero to the fossiliferous locality. instead of the path we come across the wide alghero-bosa asphalt road, with cars darting at high speed. the fossiliferous cavity was no more, but some blocks lying along the cliff gave few remains of small mammals and especially a small group of fossil bats of late pleistocene age, illustrated by kotsakis in 1987. in november 1983, malatesta led a second expedition at is oreris with elsa gliozzi and m. r. palombo; it lasted ten days and a certain amount of remnants of small vertebrates were collected from the very hard breccia. a few months later, in april 1984 malatesta led what it proved to be his last paleontological campaign in the island. the team was composed by l. caloi, d. esu, e. gliozzi, t. kotsakis and m.r. palombo. the expedition lasted about two weeks and was almost the farewell to the sardinian campaigns of malatesta. during this campaign they been visited a lot of places he had surveyed in the past. in the alabaster quarry at is oreris, further samples were collected to enrich the collection of small vertebrates under study. a few samples were also collected at capo figari (figs. 11, 12). south of alghero, while in the locality calabona the remains of many freshwater molluscs were collected. the results of both these expeditions were published by gliozzi et al. (1984) and minieri et al. (1995) as for the small mammals of the alabaster quarry and by esu (1987) as to the calabona molluscs. the fauna o. girotti, t. kotsakis & c. petronio 48 fig. 11 april 1984: sampling of the fossiliferous breccias cropping out at capo figari (sardinia). from the left: d. esu, t. kotsakis, a. malatesta, and m.r. palombo. aprile 1984: campionamento della breccia ossifera affiorante a capo figari (sardegna). da sinistra: d. esu, t. kotsakis, a. malatesta e m.r. palombo. of is oreris was composed by two insectivores “nesiotites” similis (hensel) and talpa tyrrhenica bate, two rodents, tyrrhenicola henseli major and rhagamys orthodon (hensel) and one lagomorph prolagus sardus (wagner), all members of the “classic” late pleistocene faunal assemblage of late pleistocene. as a matter of fact, palombo (2006) places the fauna of is oreris in the faunal subcomplex of dragonara, although she considered this fauna somewhat older if compared to the fauna of dragonara. malatesta returned again in sardinia to study, in collaboration with willemsen, a third endemic lutrine of the island. however this was not a campaign for field work, but a visit to the museum of nuoro. the results of the study (willemsen & malatesta, 1987) were the establishment of a new taxon, endemic to the generic level, megalenhydris barbaricina willemsen & malatesta. 6. conclusions regardless of field work for geological survey and mapping of the fifties, the number of explorative expeditions and excavation campaigns organized and directed by alberto malatesta in search of quaternary insular vertebrates were fourteen (seven in sardinia, three in sicily, three in crete and one in cyprus). the excavations were certainly not organized with a detail similar to those carried out by prehistory archaeologists and which are now the norm for palaeontological excavations in the caves. they were the typical excavations organized to recover large mammals, with an increasing attention to the collection of small vertebrates. the analysis and publication of data always followed the criteria of detailed descriptions and illustrations of all bones. the great value that malatesta’s publications have today, decades after their appearance, lies on the detailed description, and remains significant, although the systematic, phylogenetic, palaeobiogographic and palaeoecologic conclusions can be partly overcome. malatesta has not formally taught to most of his students how organize the research. but he directed some of them to the scientific paths they have later followed. he pointed to odoardo girotti a field of interest in the study of non-marine molluscs of the tiber basin. this study started the girotti’s research field on the bivalves and gastropods of brackish and continental deposits. girotti, on his turn, transmitted this research topic to daniela esu and their collaboration in this field continues without interruption since more than thirty five years. carmelo petronio, maria rita palombo, lucia caloi and tassos kotsakis and, in the early stages of his career also elsa gliozzi, have been influenced by malatesta in the researches on vertebrate fossils. if we calculate the percentage of the publications that each of these palaeontologists devoted to problems of insular fig. 12 april 1984: group photo at the end of the campaign at is oreris-capo figari (sardinia). from left: l. caloi, a. malatesta, m.r. palombo d. esu, t. kotsakis and e. gliozzi. aprile 1984: foto di gruppo al termine della campagna di scavi a is oreris-capo figari (sardegna). da sinistra: l. caloi, a. malatesta, m.r. palombo d. esu, t. kotsakis e e. gliozzi. the palaeontological campaigns of alberto malatesta in the mediterranean islands 49 vertebrates, emerge that malatesta’s influence has been considerable and constant. this influence was certainly also felt by his other students but we limit to speak here only of those who participated to the palaeontological campaigns to the islands led by him. malatesta’s character was not easy and during the expeditions he always kept a certain hierarchical structure of the staff. this was pretty easy to obtain standing in the institute and the laboratory, but became more difficult in the intimacy of the excavations and in the camps, and this sometimes led to tensions. however, that attitude weakened as the years passed. even different opinions in cultural and political fields were sometimes occasions of heated discussions, but also those were mitigated over time, with a spirit of greater understanding between the group leader and his younger colleagues, until they reached a real human warmth, when his students in 1995, celebrated his eightieth birthday. references abbazzi l., bonfiglio l., marra a.c. & masini f. (2001) a revision of medium and small sized deer from the middle and late pleistocene of calabria and sicily. boll. soc. paleont. ital., 40, pp. 115-126. accordi b. (1955) hippopotamus pentlandi von meyer del pleistocene della sicilia. palaeontogr. ital., 50, pp. 1-52. accordi b. (1972) lo scavo della “grotta simonelli” con cervi nani del quaternario, effettuato a creta nel 1971 dall’istituto di geologia e paleontologia dell’università di roma con il finanziamento dell’accademia nazionale dei lincei. quad. accad. naz. lincei, 167, pp. 1-17. accordi b. & colacicchi r. (1962) excavations in the pigmy elephants cave of spinagallo (siracusa). geol. romana, 1, pp. 217-229. angelelli f. (1980) endocranial morphology of the dwarf deer of crete. quad. accad. naz. lincei, 249, pp. 101-109. angelelli f. (1995) peculiar sensorimotor characters inferred from an endocranial cast of nesolutra ichnusae malatesta, an endemic pleistocene otter from sardinia. geol. romana, 31, pp. 15-20. angelelli f., gliozzi e. & malatesta a. (1982) l’encefalo di nesogoral melonii (déhaut), nemoredino quaternario della sardegna. boll. serv. geol. d’italia, 103, pp. 35-52. boekschoten g.j. & sondaar p.y. (1966) the pleistocene of the katharo basin (crete) and its hippopotamus bijdr. dierk., 36, pp. 17-44. caloi l. (1973) resti di cervo e di ippopotamo quaternari nella grotta di capo tindari. boll. serv. geol. d’italia, 93 (1972), pp. 227-249. caloi l. (1980) fossil carnivora of simonelli cave. quad. accad. naz. lincei, 249, pp. 111-114. caloi l. & malatesta a. (1974) il cervo pleistocenico di sardegna. mem. ist. ital. paleont. um., n. ser., 2, pp. 163-260. caloi l. & palombo m.r. (1982) hippopotamus pentlandi meyer di capo tindari (messina). geol. romana, 21, pp. 391-395. caloi l. & palombo m.r. (1991) morfologia e funzione della mano e del piede del megacerino del pleistocene superiore di dragonara (sardegna, italia). atti accad. peloritana pericolanti, cl. 1, 67(suppl. 1)(1989), pp. 319-347. caloi l. & palombo m.r. (1995) il megacerino di dragonara: interpretazione funzionale di alcuni caratteri cranici. geol. romana, 31, pp. 29-40. caloi l. & palombo m.r. (1996) functional aspects and ecological implications in hippopotami and cervids of crete. in: reese d.s. (ed.), pleistocene and holocene fauna of crete and its firsts settlers, pp. 125-151. capasso barbato l., kotsakis t. & petronio c. (1982) nuovi resti e osservazioni filogenetiche su hippopotamus creutzburgi boekschoten & sondaar (hippopotamidae, mammalia) del pleistocene di creta (grecia). geol. romana, 21, pp. 61-77. comaschi caria i. (1970) nuova segnalazione di resti di scimmia nel quaternario della sardegna. 7 pp., cagliari. conato v., esu d., malatesta a. & zarlenga f. (1980) new data on the pleistocene of rome. quaternaria, 22, pp. 131-176. esu d. (1987) contributo alla conoscenza delle malacofaune continentali quaternarie della sardegna. geol. romana, 25(1986), pp. 181-190. gliozzi e. (1985) alcune ossa appendicolari di lontra fossile del quaternario di alghero (sardegna). boll. soc. paleont. ital., 24, pp. 137-144. gliozzi e. & malatesta a. (1980) the quaternary goat of capo figari (northeastern sardinia). geol. romana, 19, pp. 295-347. gliozzi e. & malatesta a. (1982) a megacerine in the pleistocene of sicily. geol. romana, 21, pp. 311-395. gliozzi e. & malatesta a. (1983) i molluschi del paleocene di baixa chinhauanine nel bacino del rio massintonto (maputo mozambico). geol. romana, 22, pp. 85-145. gliozzi e., malatesta a. & palombo m.r. (1986) upper pleistocene small mammal associations in the is oreris area (iglesiente, sw sardinia). geol. romana, 23(1984), pp. 121-129. gliozzi e., malatesta a. & scalone e. (1993) revision of cervus elaphus siciliae pohlig, 1893, late pleistocene endemic deer of the siculo-maltese district. geol. romana, 29, pp. 307-353. kotsakis t. (1980a) i resti di anfibi e rettili pleistocenici della grotta di dragonara (capo caccia, sardegna). geol. romana, 19, pp. 85-90. kotsakis t. (1980b) short account on the elephant remains of the “simonelli” cave. quad. accad. naz. lincei, 249, pp. 115-119. kotsakis t. (1987) les chiroptères du pléistocène supérieur des environs de alghero (sardaigne, italie). geol. romana, 26, pp. 103-108. kotsakis t., melentis j., petronio c. & sirna g. (1976) seconda spedizione paleontologica lincea nell’isola di creta (1975). quad. accad. naz. lincei, 223, pp. 1-11. malatesta a. (1958) osservazioni sul pliocene e sul pleistocene della costa settentrionale della sicilia tra gualtieri-sicaminò e gioiosa marea. boll. serv. geol. d’italia, 79, pp. 291-326. malatesta a. (1962) il cane selvaggio del pleistocene della sardegna. geol. romana, 1, pp 173-189. malatesta a. (1970) cynotherium sardous studiati an o. girotti, t. kotsakis & c. petronio 50 extinct canid from the pleistocene of sardinia. mem. ist. ital. paleont. um., n. ser., 1, pp. 1-72. malatesta a. (1977) the skeleton of nesolutra ichnusae n. sp., a quaternary otter discovered in sardinia. geol. romana, 16, pp.173-209. malatesta a. (ed.)(1978a) torre in pietra. roma. quaternaria, 20, pp. 203-577. malatesta a. (1978b) on the genus cyrnaonyx helbing, 1935 (mustelidae, lutrinae) and its type species. quaternaria, 20, pp. 109-116. malatesta a. (1980) dwarf deer and other late pleistocene fauna of the simonelli cave in crete. quad. accad. naz. lincei, 249, pp. 1-97. malatesta a. & settepassi f. (1954) risultati del rilevamento del f.° 192 (alghero). iii. fossili delle formazioni continentali quaternarie. boll. serv. geol. d’italia, 76, pp. 31-42. malatesta a. & suriano f. (1970) avifauna pleistocenica di alghero (sardegna). boll. serv. geol. d’italia, 91, pp. 149-158. malatesta a. & willemsen g.f. (1986) algarolutra g. n. established for a fossil otter of the sardinia island. geol. romana, 25, pp 285-286. malatesta a. & zarlenga f. (1986) northern guests in the pleistocene mediterranean sea. geol. romana, 25, pp. 91-154. malatesta a. & zarlenga f. (1988) evidence of middle pleistocene marine transgressions along the mediterranean coast. palaeogeogr., palaeoclim., palaeoecol., 68, pp. 311-315. mangilli g. (1980) fossil reptiles of simonelli cave. quad. accad. naz. lincei, 249, pp. 121-122. melentis j.k. (1974) paläontologische ausgrabengen in der höhlen des gebietes von rethymnon, kreta. sci. ann. fac. phys. math. univ. thessaloniki, 14(17), pp. 17-24. minieri m.r., palombo m.r. & scarano m. (1995) microtus (tyrrhenicola) henseli (major, 1882) del pleistocene superiore di cava alabastro (is oreris; iglesias; sardegna sudoccidentale). geol. romana, 31, pp. 51-60. novelli m. & palombo m.r. (2007) “hunter-schreger bands” in cynotherium sardous studiati, 1857 from dragonara cave (late pleistocene, northwestern sardinia, italy). in: coccioni r. & marsili a. (eds), proceedings of the giornate di paleontologia 2005, grzybowski foundation special publication, 12, pp. 61-71. palombo m.r. (2005) food habits of “praemegaceros” cazioti (depéret, 1897) from dragonara cave (nw sardinia, italy) inferred from cranial morphology and dental wear. in: alcover j.a. & bover p. (eds.), proceedings of the international symposium “insular vertebrate evolution: the palaeontological approach”, monogr. soc. hist. nat. balears, 12, pp. 233-244. palombo m.r. (2006) biochronology of the pliopleistocene terrestrial mammals of sardinia: the state of the art. hellenic j. geosci., ser. 2, 41, pp. 47-66. palombo m.r., kohler m., moyá solá s. & giovinazzo c. (2008) brain versus body mass in endemic ruminant artiodactyls: a case studied of myotragus balearicus and smallest candiacervus species from mediterranean islands. quatern. intern., 182, pp. 160-183. palombo m.r. & petronio c. (1989) caratteri morfostruturali del femore di elephas (palaeoloxodon) creutzburgi (kuss, 1965) di grotta simonelli (rethymnon, creta). hystrix, n. ser., 1, pp. 95-105. suriano f. (1980) fossil birds of simonelli cave. quad. accad. naz. lincei, 249, pp. 123-126. willemsen g.f. (1992) a revision of the pliocene and quaternary lutrinae from europe. scripta geol., 101, pp. 1–115. willemsen g.f. & malatesta a. (1987) megalenhydris barbaricina gen. nov. sp. nov., a new otter from sardinia. proc. kon. ned. akad. wetensch., ser. b, 90, pp. 83-92. ms. ricevuto il 22/12/2010 testo definitivo ricevuto il 20/05/2011 ms. received: december 22, 2010 final text received: may 20, 2011 amq28(2)131-143 toti rivisto 12_2015 edi.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 28 (2), 2015, 131 143 interglacial vegetation patterns at the early-middle pleistocene transition: a point of view from the montalbano jonico section (southern italy) francesco toti department of earth sciences, university of florence, florence, italy corresponding author: f. toti <francesco.toti@unifi.it> abstract: the montalbano jonico succession (southern italy) represents a rich stratigraphic archive of the early to middle pleistocene environmental and climatic changes in the central mediterranean. pollen analyses associated to multivariate statistical methods (principal component and cluster analyses) have been carried out in the sedimentary portion including marine isotope stages (mis) 21 to 17 (~200 kyrs and ~190 m). the pollen ratio between mesotherm and steppic taxa (pollen temperature index), used as a proxy of temperature, permits to precise consecutive warmer and cooler phases associated, respectively, to interglacials/interstadials and glacials/stadials (substages 21.3 to 18.3 plus stage 17). pollen data suggest major expansions of mixed oak forests during warm phases, whereas open vegetation typically marks cool to cold phases. the statistical processing puts in evidence both analogies and differences among the successive interglacials/interstadials. midto high-altitude trees and mediterranean taxa appear to expand slower than hydrophytes plus deciduous oaks and other herbs, which conversely act like pioneers. moreover tsuga, cedrus plus steppic plants and poaceae are inversely related to mediterranean xerophytes and mesotherm deciduous taxa, possibly due to the different tolerance to temperature decreases. on this basis, three main vegetation patterns seem to occur during warm periods. the 1st pattern (including mis 21.3, 19.3 and 17) shows a tripartite structure with a middle warm phase including higher abundances of slow-spreading taxa, sandwiched between cooler intervals (at the beginning and the end of the sub-stage) with the increase of faster-expanding taxa. the 2nd pattern (in mis 21.1 and 19.1) shows a complex structure characterized by rapid changes in proportions between fastand slow-spreading taxa as well as among plants with different tolerance to temperature decrease. the 3rd pattern (in two interstadials within mis 18), is characterized by relatively high abundances of fast-spreading taxa and low abundances of warmth-demanding taxa. this work represents a first attempt for a better understanding of interglacial vegetation dynamics during the early-middle pleistocene transition; deeper investigations are in progress with the specific aim to better characterize the observed multiple patterns and possibly to define their causes. keywords: early-middle pleistocene transition, interglacials, mis 19, montalbano jonico, southern italy, principal component analysis, pollen analysis. 1. introduction during the transition between early and middle pleistocene (empt, 1.2-0.5 ka; e.g. head & gibbard, 2005; maslin & ridgwell, 2005), earth’s climate experienced a gradual change in the glacial-interglacial (g-i) oscillations mode. the orbital obliquity-driven 41 kyrs cyclicity, which had dominated the earlier part of the pleistocene, was overshadowed by a high-amplitude, lower-frequency 100 kyrs-rhythm. a profound impact on terrestrial and marine biota is recorded across the empt as a result of changes in the intensity and duration of both glacials and interglacials (e.g. head et al., 2008). in the italian pollen and calcareous nannoplankton records a major shift seems to coincide with the marine isotope stages (mis) 25 to 20, at the end of the jaramillo sub-chron, where several turnovers in the nannofossil communities and the progressive disappearance of the most thermophilous pollen taxa occurred (bertini et al., 2010 and references therein). on the other hand, no remarkable events have been recorded at the calabrian-ionian transition (e.g. head & gibbard, 2005; bertini et al., 2015). quaternary european and mediterranean pollen records display recurrent patterns of vegetation succession paralleling g-i cyclicity. in italy, four main patterns have been summarized on the basis of latitudinal, geomorphological and local factors by bertini (2010). pattern 1, is expressed by open vegetation-thermophilous forest alternations especially in mediterranean littoral zones (e.g. suc et al., 1995). pattern 2, which is typical of several northern apennines sites, exhibits prevalent alternations between altitudinal coniferous and thermophilous forests (e.g. bertini 2001 and references therein). patterns 3 and 4 show the presence of thermophilous and coniferous forest, respectively, during glacials, and open vegetation and steppe, respectively, during interglacials (e.g. bertoldi et al., 1989; capraro et al., 2005). the interglacial structure, its duration and intensity, as well the seasonality, strongly depend on the earth orbital geometry, which is a major factor of climate forcing (e.g. hays et al., 1976; berger, 1981; 1988). according to many authors, the vegetation succession of each interglacial is “unique” because of the peculiar combination of its astro -climatic variables (e.g. watts, 1988; bartlein & prentice, 1989; huntley & webb, 1989). moreover, even where some interglacials exhibit virtually identical orbital configurations, the occurrence of stochastic factors (e.g. relationships among taxa and/or between taxa and climate) can make the system unpredictable (e.g. bennett et al., 1991; tzedakis et al., 2012a). at the same time, the existence of interglacials characterized by very different climate conditions but showing similar vegetation patterns cannot be excluded (tzedakis & bennett, 1995); in this case, internal biotic forcings should be invoked. one of the longest composite quaternary pollen record, including subsequent interglacials since the base of the gelasian, has been reconstructed by the study of both marine and continental successions of southern italy (fig. 1) (e.g. combourieu-nebout et al., 1990; combourieu nebout and vergnaud grazzini, 1991; combourieu-nebout, 1993; capraro et al., 2005; klotz et al., 2006; joannin et al., 2008; russo ermolli et al., 2010a, b, 2014; suc et al., 2010; amato et al., 2014; petrosino et al., 2014; robustelli et al., 2014; bertini et al., 2015; marino et al., 2015). the knowledge of past interglacials is particularly significant not only because it allows the documentation of ancient paleoenvironments but also for its key role in modeling the natural course of the present interglacial (holocene), permitting predictions about the future climate changes. for this study a selected portion of the montalbano jonico (mj) section, spanning the mis 21-16, has been submitted to detailed palynological analyses which have strongly improved those recently produced in bertini et al. (2015), and extend the previous pollen documentation concerning mis 3723 (joannin et al., 2008). the main purpose of this paper is to recognize similarities and differences in the vegetation dynamics between subsequent warm periods (either interstadials or interglacials), assuming that each one is marked by a peculiar astronomical and vegetation signature. to achieve this aim, warmer phases have been singled out and compared using a multivariate statistical approach. the significance of the mj pollen record is enhanced by the possibility to exclude the presence of consistent stratigraphic gaps thanks to the strong stratigraphical frame established for this marine section (e.g. marino et al., 2015 and references therein). 2. case study: the montalbano jonico section 2.1. geological and stratigraphical setting mj composite succession is located in the basilicata region (southern italy), near the eponymous village, at 40°17’n 16°34’e (292 m above the sea level). its deposition occurred within the bradanic foredeep, a perisutural basin bounded westward by the apennine orogenic front and eastward by the murge highlands. the mj succession covers more than 630 kyrs (lower to middle pleistocene; ciaranfi et al., 2010) and has been reconstructed sewing up 10 sub-sections (ciaranfi et al., 1997; 2001). the succession is divided in two distinct portions by a stratigraphic gap (fig. 2). the lower portion (“interval a”) consists of ~180 m thick muddy turbidites including a volcaniclastic layer (v1). benthic paleocommunities assign “interval a” to an upper-slope environment involved in a prevalent shallowing upward trend (d’alessandro et al., 2003; stefanelli, 2004). the upper portion (“interval b”) is more than 300 m thick and includes silty sands and silty clays in which eight volcaniclastic layers (v2-v9) are embedded; repeated deepening-shallowing cycles, from outer to inner shelf environment, have been recognised (d’alessandro et al., 2003; stefanelli, 2004) (fig. 2). bathymetric changes have been firstly related to the north-eastward thrusting of the southern apennines units (ciaranfi et al., 1996; d’alessandro et al., 2003), and secondly to the orbital-scale g-i ciclicity and climate-driven eustatic variations, in the frame of the progressive pliopleistocene cooling (e.g. joannin et al., 2008; ciaranfi et al., 2010). based on the most recent radiometric datings 132 toti f. fig. 1 (a) location of montalbano jonico and the main sites of southern italy cited in the text. (b) view of the montalbano jonico succession in the “calanchi” badlands area, with the agri valley in the background. (39ar/40ar) on v1-v5 tephra layers (petrosino et al., 2015) and the constrains provided by the calcareous plankton (maiorano et al., 2004), sapropel (stefanelli et al., 2005) and isotopic (brilli et al., 2000) stratigraphy, marino et al. (2015) have proposed the age-model shown in fig. 2, closely related to the astronomical tuning of the section by ciaranfi et al. (2010). correlations with lr04 benthic stack (lisiecki and raymo, 2005), pacific (mix et al., 1995a,b; shackleton et al., 1995) and atlantic (bickert et al., 1997) δ18o benthic records allow the isotopic shifts related to mis 22-16 to be outlined (ciaranfi et al., 2010; marino et al., 2015). according to the calcareous plankton-inferred relative chronology (maiorano et al., 2004), “interval b” extends from the top of pseudoemiliania lacunosa zone to the base of emiliania huxleyi zone of rio et al. (1990) (fig. 2). two nannofossil events are recorded: the beginning (826.89 ka) and the end (771.04 ka) of the second temporary disappearance of gephyrocapsa omega (maiorano et al., 2004). although no sapropels occur within the 133 interglacials at the empt in southern italy fig. 2 lithostratigraphy and benthic δ18o record of the montalbano jonico composite section (brilli et al., 2000; ciaranfi et al., 2010; maiorano et al., 2010; marino et al., 2015); the age of volcaniclastic layer v4 is after petrosino et al. (2015); the studied portion is indicated on the right. (modified from bertini et al., 2015). “interval b” (stefanelli et al., 2005), three bands with higher organic carbon content are visible (fig. 2): the oldest one encloses v4 tephra (773.9 ±1.3 ka, petrosino et al., 2015), the second and last one are located below and above the end of the second temporary disappearance of gephyrocapsa omega. the present work is based on the study of eightythree palynological samples from the 67.7 m (858 ka, mis 21)-257.5 m (656.05 ka, mis 16) portion of “interval b” (fig. 2), this generating a mean time resolution of ~2463 years. however this result is based on highly uneven values throughout the succession, ranging from 60 years to more than 14 kyrs. 2.2. present climate and vegetation the mj section lies between the metapontine jonian coast, to the south-east, and the agri valley, to the north-west. the latter is part of a wider hydrographic basin including all the apennines rivers with drainage towards the taranto gulf (fig. 1). the agri valley is bordered northward by reliefs ranging from ~1700 to ~2000 m. 50 km southwest of mj, the pollino massif, with several peaks over 2000 m, separates basilicata from calabria region. the agri valley approximates the intersection between three climatic zones: the coastal metapontine area, characterized by a meso-mediterranean regime, the eastern hinterlands, with semi-continental climatic features, and the western mountain area, with rainfalls well distributed throughout the year and strong thermal and humidity gradients depending on orography. the mj section is embedded in the evocative badlands landscape, molded by the erosion of pliopleistocene marine clays. the vegetation cover is firstly influenced by edaphic factors, being the substrate the result of sediment weathering (di pietro et al., 2004). halo-xerophytic components, such as camphorosma monspeliaca, lygeum spartum and mantisalca duriaei, colonize the steepest slopes, enriched by sulla coronata when slopes are weaker. terophytes grow in more sandy and detritic soils (fascetti et al., 2001). amaranthaceae (i.e. camphorosma, atriplex, suaeda) occupy flat and more humid zones at the base of the slopes. in weakly steep areas, poorly affected by erosion processes, terophytic fabaceae (including hedysarium and scorpiurus) dominate the floristic assemblage, with sporadic ingressions of plantago afra. on flat to sub-flat surfaces, some patchy mediterranean maquis occurs; here pistacia lentiscus dominates in association with rubia peregrina, phillyrea latifolia, juniperus oxycedrus, asparagus acutifolius and helictotrichon convolutum (biondi et al., 1992; fascetti et al., 2001). the basal horizon of the surrounding relief, which extends from a few meters to 300-400 m, belongs to the olive tree-carob tree alliance (mediterranean climax), also including holm oak; it is worth noting that the latter is an important component of higher (submontane) belts, forming mid-altitude (up to 800-1000 m) woodlands (corbetta, 1974). cypresses and aleppo pines occur as reforestation elements. submediterranean to submontane horizons are marked by the presence of quercus pubescens, commonly with fraxinus ornus (plus ostrya carpinifolia, carpinus betulus and c. orientalis in moisture-rich stations), pyrus communis, sorbus domestica, crataegus oxyacantha, ligustrum vulgare, spartium junceum, osyris alba, and sclerophyll taxa such as asparagus acutifolius and pistacia terebinthus. at higher elevations quercus pubescens tends to be replaced by q. cerris, which, together with chestnut woods, characterizes the submontane horizon. beechwoods and abies alba relict formations punctuate mountain belts, together with pteridium aquilinum brackens. the undergrowth composition varies with the altitude and includes noteworthy taxa such as ilex aquifolium, geranium striatum, and stellaria nemonum (corbetta, 1974). 3. methods 3.1. palynological analyses palynological analyses have been performed on samples from the mj section’s “interval b” (“ideale”, “js” and “vct” sub-sections: see fig. 2) during the first year of phd of the author; the pollen study is still in progress in order to increase the resolution in selected intervals. at present, eighty-three sediment samples have been processed using a standard palynological technique, at the laboratory of palynology of the department of earth science of the florence university. samples have been first weighted before starting the physical-chemical treatment. lycopodium tablets have been added to each sample to estimate palynomorph concentrations. attacks with acid (hcl and hf), koh and hexametaphosphate solutions have been followed by enrichments procedures (zncl2 and 10µm sieving in ultrasonic bath). residues have been mounted in slides using glycerol and finally analyzed by optical microscope (using x750 and 1250 magnifications) for quantitative pollen analyses. a mean of 284 pollen grains per sample have been counted, pinus and cupressaceae excluded. pinus, which is generally over-represented in the marine sediments (heusser, 1988; beaudouin et al., 2005), at mj reaches very high percentage values and for this reason has been excluded from the total pollen sum (see pollen diagram in fig. 3); for the taphonomic and palaeoenvironmental significance of pinus pollen grain, see bertini et al. (2015) and marino et al. (2015). cupressaceae pollen grains have been also removed from the total pollen sum as they exhibit in some levels both very high frequencies and morphologic features which do not support their unequivocal determination. pollen data are expressed as percentages normalized to the total pollen sum, excluding pinus, cupressaceae, indeterminate and indeterminable grains; the summary pollen diagram (fig. 3) shows eleven selected informal pollen groups established on the basis of climate and ecological requirements of correlative modern taxa, which are: (1) cedrus and tsuga; (2) high-altitude taxa (abies and picea plus betula and fagus); (3) deciduous quercus; (4) broad-leaved deciduous taxa minus quercus, e.g. carpinus, ostrya, alnus, ulmus, zelkova, alnus, carya, pterocarya, ericaceae and hedera; (5) mediterranean sclerophyll taxa, e.g. quercus ilex type, olea, pistacia and cistaceae; (6) asteraceae except artemisia; (7) poaceae; (8) hydrophytes, principally cyperaceae and sparganium/typha angustifolia type; 134 toti f. (9) halophytes, e.g. amaranthaceae, caryophyllaceae and plumbaginaceae; (10) steppic taxa, e.g. artemisia and ephedra; (11) other non-arboreal plants, e.g. brassicaceae, dipsacaceae, plantago, rosaceae and saxifragaceae. arboreal pollen (ap) relative abundances have also been plotted (fig. 3) as they are expected to reflect the spreading/shrinkage of the woodland in response, respectively, to the increase/decline of the atmospheric humidity. in order to discriminate warm (temperate) from cooler to cold phases, a pollen-derived palaeotemperature index (pollen temperature index: pti, fig. 3; e.g. joannin et al., 2008, 2011; bertini et al., 2015) has been used. pti, which is given by the ratio between mesothermic and steppic taxa, puts in evidence the glacial/stadial (lower values)-interglacial/interstadial (higher values) alternation in the pollen record. we have included deciduous quercus, corylus, carpinus, ostrya, alnus, ulmus, zelkova, carya, pterocarya, tilia, hedera and ericaceae (just to mention the most abundant) among mesothermic taxa and artemiasia, ephedra, lygeum and hippophae among steppic taxa. a threshold-value of the pti has been proposed at ~2 to divide warmer by cooler phases, so that they have distinct separations (fig. 3). the so defined glacial/stadial (pti < ~2) and interglacial/interstadial (pti > ~2) phases are in good agreement in terms of both chronologic position and time extension with the major shifts in the δ8o curve (e.g. sub-stages 21.3, 21.1, 19.3 and 19.1 after: marino et al.; 2015) of the same succession. 3.2. multivariate statistical analyses pollen data relative to the samples with a pti > ~2 (assumed to belong to interglacials/interstadials, as described in methods), in which the variables are represented by the eleven (1-11) selected informal groups, have been examined through principal component analysis (pca) using variance-covariance matrix as data input. pca has been adopted as a tool for transposing the original dataset variability in a lower dimension representation. in this simplified panorama, few principal components are assumed to summarize the associations among correlated variables. centered logratio transformation as proposed by aitchison (1982) have been carried out to avoid biases deriving from the compositional (constrained) nature of the data. variability similarities between selected pollen groups have been also evaluated through hierarchical cluster analysis, that has been applied on log-centered variables by using the euclidean distance as similarity measure andward's method as the subsequent linkage algorithm. 4. results palynological analyses point out a rich flora consisting of more than 120 taxa. they are largely herbaceous; among them asteraceae, poaceae, amaranthaceae and ephedra are dominant. artemisia and ephedra show subsequent phases of significant increase, reasonably linked to steppe expansion during (cold/dry) glacial periods at the expenses of forest taxa, amaranthaceae usually paralleling the steppe taxa trends (fig. 3). among arboreal taxa, pinus pollen grains reach the highest percentage values. quercus is also well represented and its increase has been associated to the expansion of the forest during warm-temperate conditions. among the other deciduous broad-leaved taxa, carpinus 135 135 fig. 3 pollen temperature index (pti) and percentage values of selected pollen groups in the mis 21-17 interval of the montalbano jonico section. on the left, the age-model (marino et al., 2015) and the benthic δ18o curve (brilli et al., 2000; ciaranfi et al., 2010). the horizontal dashed lines define informal pollen zones corresponding to the successive warm periods (i.e. zones i-vi plus t), as specified in the column on the right. ap: arboreal plants. interglacials at the empt in southern italy betulus, c. orientalis/ostrya type, ulmus, zelkova, etc. follow. along with zelkova, other taxa which progressively disappears in the course of the pleistocene, such as carya, pterocarya and liquidambar, are still found in this portion of the mj section, where taxodium type shows scattered occurrences. cedrus and abies are the most abundant taxa among midand highaltitude conifers, respectively. as a whole the floristic composition at mj is quite uniform as pointed out and discussed for the mis 21 to mis 18 interval by bertini et al. (2015); in fact neither disappearance nor appearance events have been recorded. 4.1. vegetation and climatic signature of interglacials and interstadials the subsequent changes in the arboreal and non-arboreal pollen taxa throughout the mj succession (858 to 656.05 ka) permit to recognize a clear alternation between forest and open landscapes. they are well expressed especially by the contraposition between steppe plus other nonarboreal taxa and quercus plus other mesophilous taxa (fig. 3). based on these vegetation data, it is possible to discriminate between warmer and cooler phases. it is further possible to determine the extension of such zones through the pti. in fact, as specified in methods, pti values higher than ~2 have been assumed to depict warm-temperate conditions associated to interglacials/interstadials whereas values lower than ~2 approximate glacials/stadials (fig. 3). forty-three samples have been thus included into seven informal “warm” zones: those labeled with roman numbers (i-vi) include samples with pti stably above 2, whereas that labeled with t (=transition) includes samples with pti quickly oscillating between 1.3 and 3 (fig. 3 and tab. i). each zone can be generally correlated with a stage or sub-stage of the marine isotope stratigraphy by considering the astronomical tuning after marino et al. (2015) and the oxygen isotope stack after bassinot et al. (1994) (fig. 3). a short description of the informal zones is provided below. zone i it is described by three pollen samples covering ~12 kyrs. ap percentages are constantly high, even if changes in proportions between midto high-altitude trees and mesophilous taxa pollen are recorded. zone i is consistent with mis 21.3. zone t ap are in low percentages, with a main fall at 827.5 ka. both steppic and halophytic taxa reach a peak at 824.5 ka. short-term variations of cedrus and tsuga diffusely occur. this zone correlates with sub-stage 21.1. zone ii mesophilous arboreal taxa show quite high percentages, decreasing only in correspondence with two short-term events (at 783.5 and 774.8 ka, bertini et al., 2015) marked by the expansion of asteraceae due to humidity drops. mediterranean taxa show a significant abundance at 780.56 ka, predating the acme of quercus and a subsequent increase of high-altitude taxa. this zone correlates with isotopic sub-stage 19.3. zone iii the first portion of the interval is marked by a positive excursion of oak and mediterranean taxa. afterwards, the other mesophilous taxa plus the midto highelevations trees slightly increase. a correlation of this zone with mis 19.1 is consistent. zone iv as a whole ap percentage values are similar to those of the previous zone iii (tab. i).the ap curve shows a peak centered at 741.41 ka. such an event coincides with an increase in midto high-altitude taxa and predates the start of quercus increase at 740.12 ka. the zone extension ranges between 18.4 and 18.3 isotope sub-stages. zone v ap percentages stay quite similar to those of the previous zones. quercus relative abundances rapidly increase between 728.28 and 726.9 ka, with secondary superimposed oscillations well appreciable due to the high time-resolution. a correlation with the 18.3 isotope sub-stage can be proposed. zone vi it corresponds to mis 17 and represents the longest interglacial. it is also marked by the highest ap values (a huge shift is located at 675.42 ka). between 697.31 and 677.96 ka, high-altitude taxa are considerably abundant, whereas cedrus and tsuga show sparse occurrences. mediterranean taxa peak at 695 ka, while deciduous quercus is involved in a gradual increase up 136 toti f. tab. i montalbano jonico section: pollen-based zonation for the studied interval, associated with summary vegetation indexes. correlation with isotopic stages is also shown. tab. ii montalbano jonico section: principal component loadings for the first three axes. to 680.69 ka, followed by a dramatic rise 5 kyrs after, when high-altitude elements collapse. 4.2. principal component analysis statistical calculations on selected pollen data allow three principal components to be extracted. they are able to take into account for about 69% of the total variance, thus providing a reasonable summary of the information contained in the dataset (tab. ii). the first principal component (pc 1) encloses 30.62% of the total variance and expresses a balance in which hydrophytes, quercus, poaceae and steppic taxa (with positive loadings) are opposed to tsuga and cedrus, highaltitude taxa and mediterranean taxa (with negative loadings). pc 1 could reflect the different timing of expansion exhibited by taxa with positive loadings (fasterexpanding taxa) versus negative loadings (slowerexpanding taxa). the analysis of vegetation successions in many sites of southern europe with sufficient moisture availability confirms that non-synchronous taxa expansions occur at the onset of warm-humid periods. deciduous quercus often expands early, followed by other mesophilous trees, such as carpinus and ostrya, and then by abies, fagus and sometimes picea (tzedakis, 2007; brauer et al., 2007). in fact, some waterdemanding arboreal taxa can show delays in migration 137 interglacials at the empt in southern italy fig. 4 montalbano jonico section: plot of sample scores. (a) first vs second principal component, (b) first vs third principal component and (c) second vs third principal component. samples colours indicate the correspondent pollen zone. because they require well developed soils, which do not form until several millennia from the beginning of an interglacial; conversely, deciduous oaks can grow on less organic soils (sadori et al., 2011). further, we may expect that hydrophytes and other herbaceous taxa react more rapidly to an increase of humidity with respect to arboreal taxa. the second principal component (pc 2) accounts for the 27.73% of the total variance, and expresses a balance between mid-altitude taxa, halophytes, steppic taxa (with positive loadings) and mediterranean elements, quercus, plus other broad-leaved thermophilous trees (with negative loadings) (tab. ii). conceivably, this balance can be considered expression of the differential vegetation’s response to cooler (with mid-altitude taxa and herbs increase) and warmer (with broad-leaved deciduous taxa and mediterranean xerophytes increase) climate contexts. the third principal component (pc 3), contributing for the 10.89% to the total data variability, appears to be almost exclusively controlled by high-altitude taxa (with positive loadings) and mediterranean taxa (with negative loadings). this component can reflect the different moisture requirements of mediterranean sclerophylls (adapted to seasonal draught) and high-altitude trees (demanding more constant humidity). samples from the seven statistical units associated with zones i-vi and t, plotted as scores (the coordinates of the samples in the space of the components) on the three main components (fig. 4) show scattered distributions and overlapping domain areas. in other words, “warm” zones, regarded as groups of samples defined a priori, cannot be discriminated if the variance-covariance structure of taxa groups is applied. 4.3. cluster analysis cluster analysis on the centered-log data has therefore been run in order to discover the presence of natural associations in the dataset. the obtained dendrogram (fig. 5a) permits to point out the presence of two well distinct groups of samples, marked with different colors (blue cluster vs green cluster) which further help us to sight them across the seven “warm” zones (fig. 5b). the main clusters obtained have been separated by considering that theiroccurred only for a high rescaled distance representing anof high dissimilarity. the two clusters have been then plotted as scores on the three main components revealed by multivariate analysis (fig. 6). in fig. 6a we can see that pc 1 and pc 2 are both involved in marking the separation between the two clusters. the blue cluster shows higher values for both axes with respect to the green cluster. in fig. 6b the two clusters are plotted in a pc 1 vs pc 3 diagram, and discrimination is 138 toti f. fig. 5 (a) cluster analysis on the selected warm periods from the montalbano jonico record; dendrogram has been obtained using ward method. (b) clustered samples are sorted in function of the age. fig. 6 montalbano jonico section: plot of sample scores on the component axes already used in fig. 4. samples are marked with colours of natural associations revealed by the cluster analysis. operated by the former. again, the blue cluster assumes higher values than green cluster. no significant discrimination is obtained by plotting the samples in a pc 2 vs pc 3 diagram. 5. discussion palynological analyses point out, in agreement with the isotopic record (marino et al., 2015), the succession of climatic oscillations between mis 21 and mis 16. in particular interglacials and interstadials are well expressed by major increases in deciduous quercus and other mesophilous taxa and by pti values higher than ~2. on the other hand, glacials and stadials are characterized by the large expansion of steppe and halophytic taxa as well as by pti values lower than ~2. cluster analysis on the pollen samples from the “warm” zones (i-vi plus t) indicates that the variability in taxa percentages is expressed by two main associations of samples (i.e. blue and green clusters), showing well sorted distributions on the pca plots (fig. 6a and b). each studied interval (zones i-vi and t) includes samples associated to both blue and green cluster, except for the zone v, wich is exclusively represented by blue cluster’s samples (fig. 7). a first observation is that a similar “blue-green-blue” arrangement unites zone ii and zone vi (mis 19.3 and 17, respectively) (fig. 7). (zone i represents the last ~12 kyrs of mis 21.3 and shows a pattern very close to those better expressed in both zone ii and zone vi). analogies can also be recognised between zone iv and zone v (mis 18.3-18.4 interval and mis 18.3, respectively), since they both show the predominance (up to totality) of “blue” samples (fig. 7). instead zone t and zone iii (mis 21.1 and 19.1, respectively) show a thickly alternate blue-green pattern. key remarks arise when samples are plotted into the pc 1 vs pc 2 diagram (fig. 6a). increasing values of the pc 1 highlight major differences on the rapidity of plant community changes: hydrophytes and deciduous quercus as well as other herbaceous taxa (with positive loadings), are expected to react more quickly to palaenvironmental changes than midto high-altitude forest taxa and mediterranean sclerophylls (with negative loadings) (tab. ii). on the other hand, the pc 2 can be thought to reflect the duality among plants with different tolerance to cold: tsuga, cedrus, halophytes and steppic taxa with positive loadings -, though diffused in very different environments, can tolerate decrease in temperature; conversely, mediterranean taxa and deciduous broad-leaved elements with negative loadings have a lower tolerance to temperature decreases. blue cluster’s samples are marked by higher values for both principal component axes than green cluster’s samples (fig. 6a). hence, the former reflect periods marked by (a) not very high temperatures (higher values on pc 2) and (b) the increase of fast-spreading taxa (higher values on pc 1); vice versa, the latter suggest contexts with (c) higher temperatures (lower values on pc 2) and (d) lower abundances of pioneer taxa (lower values on pc 1). this allow some considerations to be made, in the light of the three pattern previously described: vegetation succession during mis 19.3 and 17 (and possibly 21.3) is characterized by a warm mid-phase with a relatively high percentage of slow-spreading taxa, rimmed by cooler intervals with higher abundance of fast-expanding plants (sandwich pattern). the vegetation landscape within mis 21.1 and 19.1 constantly changes from warmer states, with the increase of slow-spreading taxa, to cooler states, in which higher frequencies of fast-spreading taxa are recorded. interstadial between mis 18.4 and mis 18.3, as well as mis 18.3, show a rather monotonous vegetation pattern, marked by the constant relatively low presence of both slow-spreading and warmth-demanding taxa. this is probably due to the shortness of the warm phase that prevent those plants to settle. selected warm periods at mj section, “interval b” are different under many points of view, being their duration, time-scale position, intensity and orbital configurations widely varying. nevertheless, cluster analysis shows that the most of the variability is described by only two main classes of samples, which generally coexist within each interval. at one level, warm periods globally show more similarities than initially predicted. as hinted by tzedakis & bennet (1995), internal biotic factor such as interand intra-specific competition can be invoked to justify these analogies. at the same time, it is worth nothing that each period is characterized by a specific vegetation dynamics (see the presence of three patterns), which induce to stress the role of the forcing by external factors. 6. conclusions and perspectives mj section represents an important stratigraphic archive for the reconstruction of the early-middle pleistocene g-i cycles in the central mediterranean basin. indepth studies on flora and vegetation changes have been previously carried out by joannin et al. (2008) and bertini et al. (2015), for the mis 37-23 and mis 21-18 intervals, respectively. here, high resolution palynological analyses and statistical processing of pollen data have been performed for the interval mis 21 to 16. such an approach has permitted to characterize and compare successive warm periods in terms of duration, intensity and vegetation dynamics. the pca carried out on pti-based statistical groups has not permitted to discriminate the different warm periods. on the other hand, cluster analyses underline the presence of two natural association of samples, which bear vegetational signatures when they are plotted on principal component axes. such a double type of samples is not randomly arranged across the succession and points out three main pattern in the warm periods. since the age-model of the mj section allows correlations with the orbital geometry predicted for each period (e.g. after laskar et al., 2004), it would be possible to verify if astronomical forcing can be (at least partially) responsible for the different structure of warm periods. the chronologic model suggests a major role especially of the 100 kyrs-period oscillations. in particular, (absolute or relative) eccentricity maxima correlate 139 interglacials at the empt in southern italy well with the first (sandwich) structure. an in-depth statistical approach would permit to test relationships between orbital and vegetation phenomena but also to better understand how astronomical factors modulate vegetation changes during interglacials and warm phases (tzedakis, 2012a, b). the present study also fits the issue concerning the extent of the impact of the empt on terrestrial ecosystems. finally the high-resolution record of one of the investigated interglacials, i.e. mis 19, represents a par 140 toti f. fig. 7 selected samples of the warm periods of the montalbano jonico pollen record marked with colours from the cluster analysis -, “warm” pollen zones and oxygen isotopic curve (brilli et al., 2000; ciaranfi et al., 2010; marino et al., 2015). ticularly appreciable datum as it is now considered one of the “best analogues” of the present interglacial (berger et al., 2012; tzedakis at al., 2012a). acknowledgements this research has been financially supported by the università degli studi di firenze (fondi di ateneo, a. bertini 2011-2013) and a phd fellowship. the author is deeply grateful to adele bertini and antonella buccianti (università degli studi di firenze) for the many constructive advices. the author wish to thank luigi forte, neri ciaranfi, angela girone, patrizia maiorano and maria marino (università degli studi di bari, aldo moro). a thanks goes to elda russo ermolli and an anonymous reviewer for the thoughtful comments on the previous version of the manuscript. references aitchison j. (1982) the statistical analysis of compositional data (with discussion). journal of the royal statistical society, series b (statistical methodology), 44(2), 139-177. amato v., aucelli p., cesarano m., jicha b., lebreton v., orain r., pappone g., petrosino p., russo ermolli e. (2014) quaternary evolution of the largest intermontane basin of the molise apennine (central-southern italy). rendiconti lincei, http:// dx.doi.org/10.1007/s12210-014-0324-y bartlein p.j., prentice i.c. (1989) orbital variations, climate and paleoecology. trends in ecology and evolution, 4, 195-199. bassinot f.c., labeyrie l.d., vincent f., quidelleur x., shackleton n.j., lancelot y. (1994) the astronomical theory of climate and the age of the brunhes-matuyama magnetic reversal. earth and planetary science letters, 126, 91-108. beaudouin c., suc j.p., cambon f., touzani a., giresse p., pont d., aloïsi, j.c. marsset t., cochonat p., duzer d., ferrier j. (2005) present-day rhythmic deposition in the grand rhône prodelta (nw mediterranean) according to high-resolution pollen analyses. journal of coastal research, 21, 292-306. bennett k.d., tzedakis p.c., willis k.j. (1991) quaternary refugia of north european trees. journal of biogeography, 18(1), 103-115. berger a.l. (1981) the astronomical theory of paleoclimates. in: berger a.l. (eds), climatic variations and variability: facts and theories. reidel, dordrecht, 501-525. berger a. (1988) milankovitch theory and climate. reviews of geophysics, 26, 624-657. berger a., yin q.z., herold n. (2012) mis-11 and mis19 analogues of our interglacial. 3rd international conference on earth system modelling, september 17-21, 2012, hamburg, germany. bertini a. (2001) pliocene climatic cycles and altitudinal forest development from 2.7 ma in the northern apennines (italy): evidences from the pollen record of the stirone section (~5.1 to ~2.2 ma). geobios, 34, 253-265. bertini a. (2010) pliocene to pleistocene palynoflora and vegetation in italy: state of the art. quaternary international, 225(1), 5-24. bertini a., ciaranfi n., marino m., palombo m.r. (2010) proposal for pliocene and pleistocene land-sea correlation in the italian area. quaternary international, 219, 95-108. bertini a., toti f., marino m., ciaranfi n. (2015) vegetation and climate across the early-middle pleistocene transition at the montalbano jonico section (southern italy). quaternary international, http:// dx.doi.org/10.1016/j.quaint.2015.01.003. bertoldi r., rio d., thunell r. (1989) pliocenepleistocene vegetational and climatic evolution of the south-central mediterranean. palaeogeography, palaeoclimatology, palaeoecology, 72, 263275. bickert t., curry w.b., wefer g. (1997) late pliocene to holocene (2.6-0 ma) western equatorial atlantic deep-water circulation: inferences from benthic stable isotope. in: shackleton n.j., curry,w.b., richter c., bralower t.j. (eds), proceedings of the ocean drilling program. scientific results 154, college station (tx), 239-253 biondi e., ballelli s., taffetani f. (1992) la vegetazione di alcuni territori calanchivi in basilicata (italia meridionale). documents phytosociologiques, n.s., 14, 489-498. brauer a., allen j.r.m., mingram j., dulski p., wulff s., huntley b. (2007) evidence for last interglacial chronology and environmental change from southern europe. proceedings of the national academy of sciences, 104, 450-454. brilli m., lerche j., ciaranfi n., turi b. (2000) evidence of precession and obliquity orbital forcing in oxygen 18 isotope composition of montalbano jonico section (basilicata, southern italy). applied radiation and isotope, 52, 957-964. capraro l., asioli a., backman j., bertoldi r., channell j.e.t., massari f., rio d. (2005) climatic patterns revealed by pollen and oxygen isotope records across the matuyama-brunhes boundary in the central mediterranean (southern italy). in: head m.j., gibbard p.l. (eds), early-middle pleistocene transitions: the land-ocean evidence, geological society london, special publications, 247, 159-182. ciaranfi n., marino m., sabato l., d’alessandro a., de rosa r. (1996) studio geologico-stratigrafico di una successione infra e mesopleistocenica nella parte sud-occidentale della fossa bradanica (montalbano jonico, basilicata). bolletino società geologica italiana, 115, 379-391. ciaranfi n., d’alessandro a., marino m. (1997) a candidate section for the lower-middle pleistocene boundary (apennine foredeep, south italy). in: naiwen, w., remane, j. (eds), proceedings 30th international geological congress, 11, 201-211. ciaranfi n., d’alessandro a., girone a., maiorano p., marino m., soldani d., stefanelli s. (2001) pleistocene sections in the montalbano jonico area and the potential gssp for early-middle pleistocene in the lucania basin (southern italy). memorie di scienze geologiche, 53, 67-83. 141 interglacials at the empt in southern italy ciaranfi n., lirer f., lirer l., louren, l.j., maioran, p., marino m., petrosino p., sprovieri m., stefanelli s., brilli m., girone a., joannin s., pelosi n., vallefuoco m. (2010) integrated stratigraphy and astronomical tuning of the lower-middle pleistocene montalbano jonico land section (southern italy). quaternary international, 210, 109-120. combourieu-nebout n. (1993) vegetation response to upper pliocene glacial/interglacial cyclicity in the central mediterranean. quaternary research 40, 228-236. combourieu-nebout n., semah f., djubiantono t. (1990) la limite pliocène-pléistocène: précisions magnétostratigraphiques par l’étude sériée de la coupe-type de vrica (crotone, italie). comptes rendus de l’académie de sciences, paris (ser. ii), 311, 851-857. combourieu nebout n., vergnaud grazzini c. (1991) late pliocene northern hemisphere glaciations: the continental and marine responses in the central mediterranean. quaternary science reviews, 10, 319-334. corbetta f. (1974) lineamenti della vegetazione lucana. giornale botanico italiano 108(5), 211-234. d'alessandro a., la perna r., ciaranfi n. (2003) response of macrobenthos to changes in paleoenvironment in the lower-middle pleistocene (lucania basin, southern italy). il quaternario, 16, 167-182. di pietro r., fascetti s., pompili m. (2004) vegetation soil relationship in basilicata badlands (southern italy). symposium of the federation internationale de phytosociologie, tenerife. fascetti s., di pietro r., pompili m. (2001) aspetti sinecologici della vegetazione dei rilievi argillosi della basilicata. atti congresso società italiana fitosociologia. la vegetazione sinantropica, lipari, 2001. hays j.d., imbrie j., shackleton n.j. (1976) variations in the earth's orbit: pacemaker of the ice ages. science, 194, 1121-1132. head m.j., gibbard, p.l. (2005) early-middle pleistocene transitions: an overview and recommendation for the defining boundary. in: head m.j., gibbard p.l. (eds), early-middle pleistocene transitions: the land-ocean evidence: geological society of london, special publication, 247, 1-18. head m.j., pillans b., farquhar a. (2008) the early middle pleistocene transition: characterization and proposed guide for the defining boundary. episodes, 31, 255-259. huntley b., webb t. iii (1989) migration: species’ response to climatic variations caused by changes in the earth’s orbit. journal of biogeography, 16, 5 -19. heusser l.e. (1988) pollen distribution in marine sediments on the continental margin off northern california. marine geology, 80, 131-147. klotz s., fauquette s., combourieu nebout n., uhl d., suc j.p., mosbrugger v. (2006) seasonality intensification and long-term winter cooling as a part of the late pliocene climate development. earth and planetary science letters, 241, 174187. joannin s., ciaranfi n., stefanelli s. (2008) vegetation changes during the late early pleistocene at montalbano jonico (province of matera, southern italy) based on pollen analysis. palaeogeography, palaeoclimatology, palaeoecology, 270, 92-101. joannin s., bassinot f., combourieu nebout n., peyron o., beaudouin c. (2011) vegetation response to obliquity and precession forcing during the midpleistocene transition in western mediterranean region (odp site 976). quaternary science reviews, 30, 280-297. laskar j., robutel p., joutel f., gastineau m., correia a.c.m., levrard b. (2004) a long term numerical solution for the insolation quantities of the earth, astronomy and astrophysics, 428, 261-286. lisieki l.e., raymo m.e. (2005) a pliocenepleistocene stack of 57 globally distributed benthic δ18o records. paleoceanography, 20, pa1003. maiorano p., marino m., di stefano e., ciaranfi n. (2004) calcareous nannofossil events in the lower-middle pleistocene transition at the montalbano jonico section and odp site 964: calibration with isotope and sapropel stratigraphy. rivista italiana di paleontologia e stratigrafia, 110, 547557. marino m., bertini a., ciaranfi n., aiello g., barra d., gallicchio s., girone a., la perna r., lirer f., maiorano p., petrosino p., toti f. (2015) paleoenvironmental and climatostratigraphic insights for marine isotope stage 19 (pleistocene) at the montalbano jonico section, south italy. quaternary international, http://dx.doi.org/10.1016/ j.quaint. 2015.01.043 maslin m.a., ridgwell a.j. (2005) mid-pleistocene revolution and the ‘eccentricity myth’. in: m.j. head and p.l. gibbard (eds), early-middle pleistocene transitions: the land-ocean evidence: geological society of london, special publication, 247, 19-34. mix a.c., le j., shackleton n.j. (1995a) benthic foraminifer stable isotope stratigraphy of site 846: 01.8 ma. in: pisias n.g., mayer l., janecek t., palmer-julson a., van andel t.h. (eds), proceedings of the ocean drilling program. scientific results, 138, college station (tx), 839-856. mix a.c., pisias n.g., rugh w., wilson j., morey a., hagelberg t. (1995b) benthic foraminiferal stable isotope record from site 849: 0-5 ma. in: pisias n.g., mayer l., janecek t., palmer-julson a., van andel t.h. (eds), proceedings of the ocean drilling program. scientific results 138, college station (tx), 371-412. petrosino p., jicha b., mazzeo f.c., russo ermolli e. (2014) a high resolution tephrochronological record of mis 14-12 in the southern apennines (acerno basin, italy). journal of volcanology and geothermal research, 274, 34-50. petrosino p., jicha b.r., mazzeo f.c., ciaranfi n., girone a., maiorano p., marino m. (2015) the montalbano jonico marine succession: an archive for distal tephra layers at the early-middle pleistocene boundary in southern italy. quaternary international, http://dx.doi.org/10.1016/j.quaint.2014. 142 toti f. ms. received: may 18, 2015 final text received: july 10, 2015 10.049 robustelli g., russo ermolli e., petrosino p., jicha b., sardella r., donato p. (2014) tectonic and climatic controls on geomorphological and sedimentary evolution of the mercure basin, southern apennines, italy. geomorphology, 214, 423-435. russo ermolli e., aucelli p., di rollo a., mattei m., petrosino p., porreca m., rosskopf c. (2010a) an integrated stratigraphical approach to the late middle pleistocene succession of the sessano lacustrine basin (molise, italy). quaternary international, 225, 114-127. russo ermolli e., sardella r., di maio g., petronio c., santangelo n. (2010b) the late early pleistocene record of saticula (sant’agata de’ goti, benevento, italy). quaternary international, 225, 128-137. russo ermolli e., di donato v., martin-fernandez j., orain r., lebreton v., piovesan g. (2014) vegetation patterns in the southern apennines (italy) during mis 13: deciphering pollen variability along a nw-se transect. review of palaeobotany and palynology, http://dx.doi.org/10.1016/j.revpalbo. 2014.11.004 sadori l., jahns s., peyron o. (2011) mid-holocene vegetation history of the central mediterranean. the holocene, 21(1) 117-129. shackleton n.j., hall m.a., pate d. (1995) pliocene stable isotope stratigraphy of site 846. in: pisias n.g., mayer l.a., janecek t.r., palmer-julson a., van andel t.h. (eds), leg 138. proceedings of the ocean drilling program, scientific results, 138, 337-355. stefanelli s. (2004) cyclic stages in oxygenation based on foraminiferal microhabitats:early-middle pleistocene, lucania basin, southern italy. journal of micropaleontology, 23, 81-95. stefanelli s., capotondi l., ciaranfi n. (2005) foraminiferal record and environmental changes during the deposition of early-middle pleistocene sapropels in southern italy. palaeogeography, palaeoclimatology, palaeoecology, 216, 27-52. suc j.-p., bertini a., combourieu-nebout n., diniz f., leroy s., russo-ermolli e., zheng z., bessais e., ferrier j. (1995) structure of west mediterranean vegetation and climate since 5.3 ma. acta zoological cracoviense, 38(1), 3-16. suc j.p., combourieu nebout n., seret g., popescu s.a., klotz s., gautier f., clauzon g., westgate j., insinga d., sandhu a.s. (2010) the crotone series: a synthesis and new data. quaternary international, 219, 121-133. tzedakis p.c., bennett k.d. (1995) interglacial vegetation succession: a view from southern europe. quaternary science reviews, 14, 967-982. tzedakis p.c. (2007) seven ambiguities in the mediterranean palaeoenvironmental narrative. quaternary science reviews, 26, 2042-2066 tzedakis p.c., wolff e.w., skinner l.c., brovkin v., hodell d.a., mcmanus j.f., raynaud d. (2012a) can we predict the duration of an interglacial? climate of the past, 8, 1473-1485. tzedakis p.c., channell j.e.t., hodell d.a., kleiven h.f., skinner l.c. (2012b) determining the natural length of the current interglacial. nature geoscience, 5, 138-141. watts, w.a. (1988) europe. in: huntley b., webb iii t. (eds), handbook of vegetation science 7. vegetation history. kluwer, dordrecht, pp. 155-192. 143 interglacials at the empt in southern italy amq 23 giraudi available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 26 (2), 2013, 110 122 a late-pleistocene phase of saharan dust deposition in the high apennine mountains (italy) . carlo giraudi 1, giovanni zanchetta 2, roberto sulpizio 3 1 enea c.r. saluggia, vercelli, italy 2 dipartimento di scienze della terra, university of pisa, italy 3 cirisivu, c/o dipartimento geomineralogico, university of bari, italy corresponding author: c. giraudi <carlo.giraudi@enea.it> abstract: the presence of late pleistocene hexogen quartz-rich loess on apennine massifs, formed by limestone rocks, has been reported since the 90s of the 20th century, and indicates that the dust must come from outside areas. the thickness of the aeolian deposits decrease from south to north, becoming null north of the latitude of 42° n; thus indicating that the dust come from south. the study of new exposures on mount matese, where the loess is interbedded with tephra layers and in proglacial lake sediments, have led to a more detailed chronology of the phases of sedimentation. specifically, we have established that the loess deposition was contemporaneous with the late pleistocene phases of intense saharan dust sedimentation in maar lakes in italy, and in the mediterranean sea. the geochemical characterization and the recognition of three tephra layers have enabled us to establish that the end of the loess sedimentation occurred at the transition between the oldest dryas stadial (or greenland stadial gs-2) and the bölling/alleröd interstadial (or greenland interstadial gl-1), simultaneously with the start of the african humid period. we hypothesize, therefore, that the quartz-rich loess in the apennines was formed by the sedimentation of saharan dust. the greater amount of dust, brought by southerly winds, would have been sedimented during periods of increased aridity in north africa which were coeval with the apennines last glacial maximum and stadial phases. keywords: late pleistocene, saharan loess, tephra layers, apennine chain, peninsular italy. 1. introduction the sahara produces more aeolian dust than any other world desert, and saharan dust has an important impact on soil formation and sediment cycles (goudie & middleton, 2001). its influence spreads far beyond africa, due to the great distances over which saharan dust is transported. deposition of dust to land surfaces may produce terra rossa soils in southern europe and the levant (yaalon & ganor, 1973; macleod, 1980; rapp, 1984) and loess (rapp & nihlén, 1991; stuut et al. 2009). the present saharan dust sedimentation in italy is well known and has been studied at least since the ’50 (fett, 1958). southern air masses bring dust of saharan origin to the northern shore of the mediterranean sea and, sometimes, to far northern latitudes (franzén et al., 1994). saharan dust sedimentation on the apennines is easily documented at higher altitudes, where, at the end of winter, the snow contains several thin dust horizons light brown-pink in colour. on the high mountains of the central and southern apennines is present a late glacial loess, of the same color of the saharan dust, , mainly consisting of quartz (frezzotti & giraudi, 1990a; 1990b; giraudi 1997,1998a, 2001, 2004; zanchetta et al., 2012). since the massifs on which the loess is present are of limestone rocks, dust quartz-rich must come from outside areas, and the sahara was considered the possible source region (giraudi,2011). the occurrence of saharan dust in the late pleistocene and holocene sediments of the italian peninsula has been proposed by narcisi (2000) which documented the presence of varying percentages of aeolian quartz in the sediments cored in the volcanic maar lakes formed by sio2 under-saturated ultra-potassic rocks. the sedimentation rate of quartz has undergone significant changes over time, but the sedimentation has never ceased altogether. andreucci et al. (2012) also provided evidence for saharan dust sedimentation during the late pleistocene in the island of sardinia. the presence of late pleistocene and holocene sediments partially formed by saharan dust, confirms that, also in the past, southern air masses have reached the italian peninsula. in the present paper new data on the high apennines loess are reported and some stratigraphic successions are discussed in order to provide a reliable chronological framework and establishing the climatic factors leading the variation of the dust transport and deposition in central-southern italy (e.g. humidity variation versus southern circulation weakness). in some sections studied on the matese massif (fig. 1), the quartz -rich loess is interbedded with tephra layers from eruptions of the nearby phlegrean fields. the geochemical characterization of three tephra layers, in addition to improve the dating of the sedimentation of the loess, allows us to correlate and synchronize the studied succession with stratigraphic records containing the same tephras. the dating of the loess also allows a close chronological correlation with some documented phases of increase and decrease in saharan dust sedimentation in the mediterranean sea and the atlantic ocean. 2. methods the lithostratigraphic data reported in the present paper were collected by studying exposed sedimentary successions and short cores retrieved through a hand augers. the studied sites are located above 1400 m a.s.l. in areas glaciated during the local last glacial maximum (lgm) and following stadial phases in some central-southern apennine massifs, consisting of mesocenozoic limestone. the carbonate composition of the catchment excludes a local source of the aeolian quartz. attention has been paid more on the aeolian deposits that cover moraines, formed during lgm or in subsequent stadial phases, or that lie in small retromorainic closed depressions formed by the melting of dead ice. the choice of these conditions warrant, even in the absence of absolute dating, a reliable correlation with the late pleistocene phases of expansion and retreat of the glaciers, which had a primary role in the shaping of the higher apennine massifs. in addition, the sediments on the summit of moraine ridges may have been formed only by aeolian deposits and tephra layers, while the lacustrine sediments lying inside closed depressions, having an endorheic drainage, can only come from the very small catchments with the contribute of aeolian sediments and tephra layers. although the aim of the present study is the dating of the loess deposition, we also report some grain size analyses (performed by frezzotti & giraudi, 1990a; 1990b) of the loess from the matese site a (in fig. 1), and sites on the m. greco massif, where the aeolian sediment are better preserved (fig. 1; 2) in the other sections, the aeolian origin of the sediments identified as loess is confirmed by the microscopic observation of the quartz grains, which are giraudi c. et al 111 fig. 1 – reference map and outline (inset) of the main glacial features and deposits on the matese massif . the location of the stratigraphic sections studied is also shown. 112 late-pleistocene phase of saharan dust deposition in the high apennine mountains (italy) frosted. moreover, when sediments are not affected by pedogenesis, field recognition of the loess is quite simple thanks to its colour (in general 7.5yr 4/6, munsell soil colour chart) which contrast with background of the non-aeolian deposits. in order to verify the presence of quartz of aeolian origin, the mineralogical composition of proglacial lacustrine sediments has been considered. the chronology of the phases of aeolian sedimentation is based on the correlation between glacial and aeolian deposits, on radiocarbon datings of organic matter in the sediments, and on the recognition of tephra layers by geochemical methods. samples collected in the field for geochemical analyses were air dried, then washed in diluted h2o2, filtered and dried in an oven at 40 °c for ca 24 h. the samples were quite rich in glass shards, so no enrichment procedure was performed. the samples were then embedded in epoxy resin and screened for glass shards and micro-pumice fragments using scanning electron microscopy (sem). energy-dispersive-spectrometry (eds) analyses of glass shards and micro-pumice fragments were performed using an edax-dx microanalyzer mounted on a philips sem 515 at the dipartimento di scienze della terra, university of pisa, employing a 20 kv acceleration voltage, 100 s live time counting, 2100-2400 shots per second, and zaf correction. the zaf correction procedure does not include natural or synthetic standards for reference, and requires the results to be normalized at a given value (which was chosen as 100%). eds data were calibrated using a combination of well characterized natural minerals (see marianelli & sbrana, 1998; zanchetta et al., 2012). to avoid alkali loss, especially na, a window spot usually ca 10 μm wide was used. owing to the different shape and size of the glass shards, a smaller size was sometimes used and this could influence analytical data (hunt and hill, 2001). several trials for comparing the performance of the pisa sem-eds with wave dispersion spectroscopy (wds) have been extensively discussed by cioni et al. (1997), marianelli & sbrana (1998), vogel et al. (2010), sulpizio et al. (2010) and caron et al. (2010, 2012). 3. results 3.1. occurrence of quartz-rich loess 3.1.1. periglacial deposits of the central and southern apennine massifs the presence of a loess formed mainly by quartz (up to 70-80%) in the highest central and southern apennine massifs has been reported by frezzotti & giraudi (1990a; 1990b), giraudi (1997,1998a, 2001, 2004), zanchetta et al. (2012). the loess, studied in different exposures and characterized from the mineralogical and granulometric point of view by frezzotti & giraudi (1990a; 1990b), always lies at the top of glacial and fluvioglacial sediments matching the post-lgm phases of glacial retreat. the loess sedimentation occurred before the formation of a peat layer dated 16,514-14,280 cal a bp. however, in glacial and periglacial environments subject to erosion and cryoturbation processes, the preservation of late glacial aeolian deposits may have been discontinuous. the peat horizon may have been deposited on erosion surfaces. therefore, the dating of the end of the aeolian sedimentation assumed in the literature remains uncertain. the loess also represent the oldest sediments that fill the dead-ice depressions between the lgm moraines fig. 2 the a-f stratigraphic sections studied on the matese massif showing the presence of sediments of glacial, aeolian, colluvial origin, tephra layers and soils (site location in fig.1). fig. 3 – grain size curves of the quartz-rich loess sampled in stratigraphic section a (site location in fig.1), on the matese massif, and in the aremogna and polverino plains, on the greco massif. modified from frezzotti & giraudi (1990a; b). (giraudi, 2001; zanchetta et al., 2012). the new exposures studied on m. matese (fig. 2) confirm that the loess formed mainly of quartz lies on lgm and some stadial moraines. the stratigraphic sections show quite different sedimentary sequences. the section a (frezzotti & giraudi, 1990a) shows a c. 20 cm-thick layer of aeolian silt, coloured 7.5yr 4/6; the grain size of the bulk sediment (fig. 3) is those typical of a loess. the loess is made mainly by quartz (about 70%), calcite and phyllosilicates. excluding quartz, part of the other minerals could have a local origin. in the section a, the loess is covered by the matese 1 tephra. this tephra, according to frezzotti & narcisi (1996) was deposited during the eruption of the phlegrean fields known as neapolitan yellow tuff. the tephra is covered by volcanic mineral-rich aeolian sediments. the loess is easily recognizable because of its colour which is very different from that of the sediments formed by carbonate clasts, i.e. whitish and light brown, and from that of tephra layers and aeolian deposits consisting of reworked volcanic minerals showing different grain-size and mineralogical components and a variety of colours. in addition, in the other sections, the aeolian origin of the sediments identified as loess is confirmed by the microscopic observation of the quartz grains, which are frosted. the section b (fig. 1; 2) is formed by blocks of carbonate rocks in sandy silt matrix, which form one of the stadial moraines of m. gallinola, covered by thinner sediments. the post-glacial sediments have been sampled through a hand auger and are formed by: aeolian silt, coloured 7.5yr 4/6 of the munsell soil colour chart, 20-25 cm thick; the silt corresponds to the loess of the section a sampled a few hundred metres away; tephra layers, about 10 cm thick, consisting of greenish sandy silt (matese 5); aeolian silt (loess), coloured 7.5yr 4/6 of the munsell soil colour chart, 5-15 cm thick; tephra sandy-silty, light green at the base and then grey-yellow, 30 cm thick (matese 1); volcanic mineral-rich aeolian sediments. the section c, like the section b, is formed by blocks of carbonate rocks in sandy silt matrix, which form the moraines. the glacial debris is covered by thinner sediments, sampled through a hand auger, formed by: aeolian silt, coloured 7.5yr 4/6 of the munsell soil colour chart, about 10 cm thick; the silt corresponds to the loess of the section a sampled a few hundred metres away; 80 cm of colluvium; 25 cm of colluvial soil; tephra sandy-silty, greenish in colour, 10 cm thick (matese 5). volcanic mineral-rich colluvial soil; quartz-rich aeolian silt, coloured 7.5yr 4/6 of the munsell soil colour chart, about 10 cm thick; tephra sandy-silty, light green at the base and then grey-yellow, 25 cm thick (matese 1); volcanic mineral-rich aeolian sediments. the section d, close to the c section, is an exposure of sandy-silty sediments overlying blocks in sandy silt matrix forming the campo puzzo lateral moraines. the sediments are formed by: aeolian silt the silt, 10-15 cm thick, corresponding to the loess of the section a, sampled a few hundred metres away, containing interbedded colluvial horizons, coloured 7.5yr 4/6 of the munsell soil colour chart; tephra layers, about 5-10 cm thick, consisting of greenish sandy silt (matese 5); aeolian silt (loess), coloured 7.5yr 4/6 of the munsell soil colour chart, 5-15 cm thick, containing a thin colluvial horizons formed by phyllosilicates and reworked volcanic minerals; tephra sandy-silty, light green at the base and then grey-yellow, 30 cm thick (matese 1); volcanic mineral-rich aeolian sediments with a convoluted lamination. the section e is an exposure close to the d section. the sediments deposited at the top of the stadial moraine are formed by: a few centimeters thick aeolian silt, coloured 7.5yr 4/6 of the munsell soil colour chart; the silt corresponds to the loess of the section a; tephra sandy-silty, grey in colour (matese 2) about 57 cm thick; tephra sandy-silty, light green at the base and then grey-yellow, 25-30 cm thick (matese 1); volcanic mineral-rich aeolian sediments. the section f, an exposure about 1 km ne of the sections a and b, is formed by: blocks of carbonate rocks in sandy silt matrix, which form one of the stadial moraines of m. gallinola; aeolian silt, coloured 7.5yr 4/6 of the munsell soil colour chart, 10-15 cm thick; the silt corresponds to the loess of the section a; colluvial silt, 10-15 cm thick; tephra sandy-silty, light green at the base and then grey-yellow, 30-50 cm thick (matese 1); colluvial sediments and colluvial soils containing a tephra layer. the tephra, identified by zanchetta et al. (2012), was produced by the agnano monte spina eruption of the phlegrean fields, dated to the midholocene. the difference between the sediments of the studied sections shows that we are dealing with very discontinuous sedimentary successions, as one would expect at high altitudes in a former periglacial environment. in spite of this, the phases of the loess and tephra deposition are generally well recognisable and the difference between quartz-rich and volcanic mineral-rich aeolian sediments is very easy to detect in the field because the colour, the grain size and the mineralogical composition. the composite stratigraphy of the post-glacial sediments in the studied area is as follows (from bottom to top): blocks of carbonate rocks in sandy silt matrix, which form one of the stadial moraines of m. gallinola; aeolian silt, coloured 7.5yr 4/6 of the munsell soil colour chart; in section d the silts contain interbedded colluvial horizons; tephra layers, about 10 cm thick, consisting of green 113 giraudi c. et al ish sandy silt (matese 5); aeolian silt (loess), coloured 7.5yr 4/6 of the munsell soil colour chart; in section d thin colluvial horizons are intebedded with aeolian silts; tephra sandy-silty, grey in colour (matese 2); tephra sandy-silty, light green at the base and then grey-yellow (matese 1). the deposition of the loess began before the fall of tephra layer matese 5 and ended before the fall of tephra matese 2 and matese 1. the sediments deposited after the fall of the matese 1 tephra are not discussed in detail, but it should be noted that the aeolian sand and silt, consisting of reworked volcanic minerals younger than matese 1 (section d, fig. 2), show a convoluted lamination. these sediments were deformed by cryoturbation processes, already observed on m. matese by palmentola & acquafredda (1983). it follows that the cryoturbation must have occurred in a period of intense cold that followed the fall of matese 1 tephra, corresponding, according to giraudi (1997), to the younger dryas. in section f, the matese 1 tephra is followed by colluvia and colluvial soils containing the tephra layer matese 4 dated to the mid-holocene. 3.1.2. lake sediments on other mountains of the central apennines in order to check whether the sedimentation of quartz-rich dust occurred also during the local lgm, some analyses have been carried out on the mineralogical composition of lake sediments of pro-glacial environment. microscopic observations and mineralogical analyses carried out on some samples by means of x-ray diffractometry (anselmi b., unpublished data) evidenced high percentages of quartz (around 20%) in some sediments, found on the gran sasso massif (42°24’n, 13° 38’e) (fig. 1), dated at about 27-26 cal ka bp by giraudi & frezzotti (1997). also the analyses of the sediments from another pro-glacial lake formed during the local lgm of the most extensive glacier of monte terminillo (42°30’n, 12°58’e), with a catchment basin of limestone, reported by giraudi (1998c), revealed a content of quartz slightly more than 20%. this implies that the aeolian sedimentation on the apennine mountains began before than previously assumed. in addition, the dust sedimented at least up to the latitude of m. terminillo, but the amount was not sufficient to produce distinctive layer to be observed in exposures. finally, it is clear that the sedimentation of aeolian quartz was contemporary to the apennine glacial expansions and retreats. 3.2. tephrostratigraphy of the matese samples the chemical composition of the tephra layers matese 1, matese 2 and matese 5 was determined in order to establish the possible provenance and the correlation with known eruptions and thus to obtain a more precise chronology of the studied successions. the tephra layers considered are interbedded with or lying on top of the loess, and so the correct identification of the tephra layers can enable us to have a chronological constraint for the end of the aeolian sedimentation and for correlating it with other environmental events documented by proxy-data of sedimentary records containing the same tephras (e.g. lowe, 2011; lowe et al., 2007; zanchetta et al., 2011). matese 1 (lab. code pi107). it was sampled in the section e (fig. 1, 2). chemical composition (table 1) matches quite well with the compositional variability observed in the neapolitan yellow tuff (tomilinson et al., 2012), which has been found in distal setting and make this layer quite characteristic for its identification (fig. 4; narcisi, 1999; siani et al., 2004; wulf et al., 2004; lane et al., 2011), including the studied area (e.g. frezzotti & narcisi, 1996). chronology of the nyt is not completely defined. bayesian integration of dating and stratigraphic information suggest an age for nyt of 14,320-13,900 cal a bp (blockley et al., 2008). whereas 39ar/40ar dating indicate an age of 14.9±0.4 ka (deino et al., 2004). lake monticchio record based on varve counting and extrapolation of sedimentation rate in intervals not varved shows an age of 14,120±710 varve yr bp. these ages are in agreement with the dating of a peat layer below nyt reported by frezzotti & giraudi, (1990a). overall, these ages partially overlap in the 2σ range. stratigraphically, however, this may be considered within the greenland interstadial i (gi-1) in the greenland event stratigraphy (siani et al., 2004), as also shown by the pollen data from lägsee (austria, schmidt et al., 2002) and monticchio (wulf et al., 2004). matese 2 and matese 5 (lab. code pi108). the matese 2 sample was taken in section e, while the matese 5 sample came from section d (fig. 1, 2). these levels, on the basis of their stratigraphic position (just below nyt) and homogenous trachytes composition, can be correlated with the so-called tufi biancastri (pappalardo et al., 1999; tomlinson et al., 2012). tufi biancastri have been dated by the 40ar/39ar method yielding ages between 14.6 ±0.6 and 17.9±0.5 ka. at monticchio an ash layer correlated with tufi biancastri is dated at 14,560±710 varve yr bp (wulf et al., 2008). these levels also correspond to ln1 and ln2 in the marine core md90917 (siani et al., 2004). in this core the ln1 and ln2 tephras have an age of between ca 13.8 ka to 15.2 ka cal bp. oxygen isotope curves suggest that ln1 and ln2 tephra deposition occurred between the onset of gi-1 and the end of the greenland stadial gs-2 (siani et al., 2004). recently these tephra layers seem to be present also at lake prespa (aufgebauer et al., 2012), as in core md90917 they are probably close to the base of bölling /alleröd and one at the transition between the oldest dryas and bölling/ alleröd. however, these deposits are currently poorly known in terms of age, chemistry and dispersion. 3.2. other occurrences of quartz-rich loess in central and southern apennine massifs the apennines quartz-rich loess has been identified also in exposed or cored sedimentary succession taken in small depressions associated with late pleisto 114 late-pleistocene phase of saharan dust deposition in the high apennine mountains (italy) cene glacial landforms, from pollino to velino massifs (frezzotti & giraudi 1990a; 1990b; giraudi, 1997;1998a; 2001; 2004; zanchetta et al.,2012). two grain-size analises of the loess (fig. 3) have been reported by frezzotti & giraudi (1990a; 1990b). in the central apennines the sedimentary series containing the loess are, generally, formed by: lgm or stadial till or glaciofluvial deposits formed by gravel in a whitish calcareous sandy-silty matrix, at the bottom; at the top of the glaciofluvial deposits the matrix is darker and enriched by quartz. quartz-rich loess, formed by silt, coloured 7.5yr 4/6 (munsell soil colour chart), from a few to 40 cm-thick deposits. where the thickness of the loess is greater, the sediments at the top are depleted in carbonates which increase toward the bottom. the mineralogical analysis of the sediments has evidenced that quartz is prevalent and that calcite, muscovite and kaolinite are present. therefore, the minerals are mostly allothigenous. in some places, near the top of the loess there is a very thin tephra layer, formed by glass, kfeldspar, plagioclase, pyroxene and amphibole. 115 tab. 1 major oxides for the studied tephra. giraudi c. et al 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 mean st dev sio2 58.76 61.47 60.7 60.71 60.98 60.66 57.34 57.06 57.82 60.58 60.5 59.6 60.9 58.09 57.31 59.50 1.59 tio2 0.6 0.23 0.52 0.4 0.41 0.41 0.56 0.59 0.69 0.5 0.39 0.47 0.46 0.34 0.59 0.48 0.12 al2o3 19.3 18.72 19.06 19.77 19.07 19.11 19.29 19.02 19.29 18.88 19.3 19.04 19.01 19.48 19.37 19.18 0.26 feotot 3.85 2.91 3.07 3.43 2.9 3.02 4.87 5.25 4.62 3.16 2.69 3.68 2.85 4.29 4.77 3.69 0.86 mno 0.23 0 0.13 0 0.25 0.08 0.13 0.1 0.17 0.08 0.24 0.22 0.24 0 0.16 0.14 0.09 mgo 0.96 0.72 0.7 0.76 0.5 0.61 1.32 1.76 1.2 0.76 0.82 0.91 0.48 1.35 1.52 0.96 0.39 cao 2.99 2.33 2.47 2.45 2.21 2.42 4.12 4.79 3.68 2.43 2.15 2.94 2.19 3.85 4.18 3.01 0.88 na2o 4.29 4.27 4.36 4.23 4.62 4.53 3.51 3.37 3.75 4.05 4.2 4.28 4.7 3.89 3.88 4.13 0.39 k2o 8.48 8.76 8.49 7.67 8.57 8.58 8.35 7.57 8.3 9.07 9.19 8.31 8.61 8.22 7.8 8.40 0.46 p2o5 0 0 0 0 0 0 0 0.04 0 0 0 0 0 0 0 0.00 0.01 clo 0.54 0.59 0.51 0.59 0.51 0.58 0.51 0.44 0.48 0.48 0.53 0.56 0.55 0.5 0.43 0.52 0.05 total 100.00 100.00 100.01 100.01 100.02 100 100 99.99 100 99.99 100.01 100.01 99.99 100.01 100.01 total alkali 12.77 13.03 12.85 11.9 13.19 13.11 11.86 10.94 12.05 13.12 13.39 12.59 13.31 12.11 11.68 alkali ratio 1.98 2.05 1.95 1.81 1.85 1.89 2.38 2.25 2.21 2.24 2.19 1.94 1.83 2.11 2.01 1 2 3 4 5 6 7 8 9 10 11 12 mean st dev sio2 61.08 60.93 60.79 60.75 61.23 60.88 60.78 61.11 61.08 61.22 60.78 60.92 60.96 0.18 tio2 0.22 0.28 0.44 0.44 0.22 0.43 0.42 0.36 0.42 0.52 0.45 0.35 0.38 0.10 al2o3 19.15 19.21 19.21 18.9 19.18 18.93 19.07 19.13 18.89 19.12 19.11 19.14 19.09 0.12 feotot 2.82 2.87 2.95 2.89 2.81 2.95 2.92 2.87 3.02 2.84 3.01 2.79 2.90 0.08 mno 0 0.08 0.25 0.24 0 0.2 0.09 0 0.08 0.24 0.16 0.13 0.12 0.10 mgo 0.53 0.63 0.44 0.54 0.36 0.35 0.57 0.46 0.55 0.49 0.56 0.64 0.51 0.09 cao 2.24 2.31 2.16 2.26 2.21 2.31 2.15 2.14 2.09 2.12 2.23 2.23 2.20 0.07 na2o 4.79 4.58 4.37 4.43 4.48 4.46 4.62 4.52 4.43 4.51 4.42 4.29 4.49 0.13 k2o 8.59 8.6 8.82 8.99 8.99 8.96 8.78 8.92 8.86 8.44 8.77 9.01 8.81 0.18 p2o5 0 0 0 0 0 0 0 0 0 0 0 0 0.00 0.00 clo 0.6 0.52 0.58 0.56 0.52 0.54 0.58 0.5 0.59 0.52 0.51 0.5 0.54 0.04 total 100.02 100.01 100.01 100.00 100.00 100.01 99.98 100.01 100.01 100.02 100.00 100.00 total alkali 13.38 13.18 13.19 13.42 13.47 13.42 13.4 13.44 13.29 12.95 13.19 13.3 alkali ratio 1.79 1.88 2.02 2.03 2.01 2.01 1.90 1.97 2.00 1.87 1.98 2.10 1 2 3 4 5 6 7 8 9 10 mean st dev sio2 63.33 63.67 62.5 63.42 63.85 63.26 63.58 63.41 63.14 63.51 63.37 0.37 tio2 0.38 0.27 0.5 0.4 0.22 0.37 0.27 0.22 0.43 0.38 0.34 0.09 al2o3 18.47 18.35 18.77 18.33 18.36 18.19 18.46 18.63 18.91 18.48 18.50 0.22 feotot 2.29 2.42 2.53 2.42 2.26 2.37 2.21 2.39 2.75 2.15 2.38 0.17 mno 0.12 0.19 0.16 0.18 0 0.15 0.13 0.09 0.21 0.06 0.13 0.06 mgo 0.24 0.3 0.33 0.25 0.27 0.41 0.37 0.28 0.24 0.26 0.30 0.06 cao 1.45 1.4 1.65 1.47 1.53 1.53 1.52 1.57 1.4 1.53 1.51 0.08 na2o 6.14 5.8 5.47 5.88 5.77 6.13 6.08 5.62 5.86 5.94 5.87 0.22 k2o 6.97 6.91 7.52 6.94 7.17 7.03 6.77 7.21 6.4 7.15 7.01 0.30 p2o5 0 0 0 0 0 0 0 0 0 0 0.00 0.00 clo 0.61 0.7 0.57 0.72 0.59 0.57 0.59 0.59 0.66 0.54 0.61 0.06 total 100.00 100.01 100.00 100.01 100.02 100.01 99.98 100.01 100.00 100.00 total alkali 13.11 12.71 12.99 12.82 12.94 13.16 12.85 12.83 12.26 13.09 alkali ratio 1.14 1.19 1.37 1.18 1.24 1.15 1.11 1.28 1.09 1.20 matese 1 matese 2 matese 5 colluvium made of quartz-rich silt derived from the loess, from a few to 30-40 cm thick. in some cases, interbedded with the colluvium, there is a thin tephra layer, having the same mineralogical composition of the horizon near the top of the loess. tephra layer from a few to 20 cm thick, studied in a number of sedimentary sequences, correlated to the neapolitan yellow tuff (nyt) volcanic eruption from the phlegraean fields (frezzotti & narcisi, 1996). silt of lacustrine or aeolian origin derived from the reworking of the nyt. alternating soils, lacustrine or colluvial deposits, and tephra layers dated at the holocene. the colluvium older than the nyt was not found in the sections where the tephra layer is interbedded with the loess. therefore, it is likely that the real top of the loess was contemporaneous with the sedimentation of the colluvium. in the aremogna plain (monte greco massif), at the top of the loess lies a peat layer dated 16,514-14,280 cal a bp (frezzotti & giraudi, 1990a). summing up, the stratigraphy of the sections where the loess was observed, described in previous papers, is very similar to that studied in the new exposures on mount matese. in the deepest depression of a former glacial cirque on mount greco, at an altitude above 2000 m, a 116 fig. 4 a) total alkali (k2o + na2o) vs sio2; b) feotot vs cao and c) mgo vs sio2, for the samples analyzed. along with the chemical data for matese 1 , 2 and 5, the chemical data for tm8a and tm8b for the neapolitan yellow tuff from monticchio (wulf et al., 2004, 2008) and tm9 (correlated with tufi biancastri) are reported for comparison purposes. data for zs98261 and zs98261 are for samples ln1 and ln2 for proximal data (from siani et al., 2001, 2004). late-pleistocene phase of saharan dust deposition in the high apennine mountains (italy) borehole made using a hand auger showed the presence of the quartz-rich loess, lying on glacial debris, covered by volcanic material and soils. in the same cirque, a fresh layer of quartz-rich silt, up to 7 mm thick, was found by one of us (c.g.) at the end of july 1992, in places partially covering short herbs still alive. the dust probably was deposited during a substantial fall of saharan dust, in early march 1991, which covered an area of at least 320,000 km2 stretching from sicily to the south to sweden and finland to the north (stuut et al., 2009). the dust was probably deposited on the snow and during the melting of the snow accumulated in the cirque depression. 4. discussion the set of stratigraphic data and the analysis of the tephra layers show that in the central-southern apennines the sedimentation of quartz-rich loess began at least 27-26k cal a bp and ended in a period bracketed by the fall of the two tufi biancastri tephra layers, that is at the transition between the oldest dryas stadial and the bölling/alleröd interstadial. in some areas, a colluvial reworking of the loess deposits occurred during the period just before and after the fall of the older tufi biancastri (matese 5) tephra, and simultaneously with the final stages of aeolian sedimentation. the sedimentation of colluvia implies geomorphological instability, and suggests, as demonstrated in other apennine massifs (giraudi et al., 2011), cold climatic conditions. as a consequence, we can conclude that the end of the loess sedimentation occurred before the start of the bölling/alleröd interstadial, or, if one refers to the glacial chronology of the apennines, before the venacquaro interstade (giraudi, 2012). the quartz-rich loess, for its mineralogical composition, is an exception among the aeolian deposits found in the mountains of the central-southern apennines. the other late pleistocene and holocene aeolian sediments found in the same massifs (frezzotti & giraudi, 1990a;1990b) have different mineralogical composition. the aeolian sediments, when originated from the deflation of the matrix of fluvial or glaciofluvial deposits, are made up of silt or sandy silt, whitish or light brown in colour, consisting mainly of carbonate. other aeolian sediments made up of silt and sandy silt, predominantly grey and yellowish or brown in colour, and having quite a varied mineralogical composition, derive from tephra layers or from the degradation of soils containing mostly volcanic minerals. late pleistocene loess deposits are well known in northern italy (cremaschi, 1990; rellini et al., 2009) but their geographical distribution ends on the northern slope of the northern apennines. two loess horizons 117 fig. 5 comparison between the phase of sedimentation of the quartz-rich loess on the apennines, quartz variations in the sediment core of the lake vico (modified from narcisi, 2000), apennines glacial phases (modified from giraudi, 2012), stadial and interstadial events in greenland gisp 2 ice core (modified from grootes et al., 1993 and svensson et al., 2006), and terrigenous flux from the sahara in the atlantic site 658c (from demenocal et al., 2000). the tephra layers matese 5 and ln2, formed during the tufi biancastri older eruption, and matese 2 and ln1, formed during the tufi biancastri younger eruption, are reported and plotted with the quartz-rich loess and the chronozones related to the lake prespa sediments (from aufgebauer et al., 2012). explanation of abbreviations: yd= younger dryas; gi-1= greenland interstadial 1; gs-2= greenland stadial 2. giraudi c. et al and interbedded soil have been found on the adriatic slope of the central-northern apennines (chiesa et al., 1990): the younger loess, dated at the upper pleistocene was associated with mousterian artefacts (>40 ka) and therefore older than the loess studied in the present paper. the thickness of the quartz-loess on the various massifs can be used to trace the origin of air masses. the thickness decreases from south to north (frezzotti & giraudi, 1990a; 1990b; giraudi, 1997,1998a,1998b, 2001, 2004) from a maximum thickness of about 70-100 cm on mount pollino (lat. 39°54'n, long. 16°12'e) and mount sirino (40°06'n, 15°52'e), to 10-40 cm on mount matese (41°26'n, 14°24'e), and to 10-30 cm on mount greco (41°47'n, 13°59'e). the thickness is reduced to a few centimetres on the mount velino (42°13'n, 13°25'e). it is therefore possible to assume that the dust has been transported by air masses from the south. today, the dust sedimentation in the mediterranean and in italy is produced by the circulation of southern air masses (guerzoni & chester, 1996; guerzoni et al. 1997). according to prodi & fea (1979); the proximity of italy to north africa and the relief of the italian peninsula favours the fall of saharan dust. the air masses bring dust of saharan origin to the northern shore of the mediterranean sea and, sometimes, to far northern latitudes, as far as sweden and finland (franzén et al., 1994). present saharan dusts are made up mainly of quartz, but carbonates, feldspars and clay minerals are present (lenaz et al., 1986; nihlén et al., 1995; guerzoni et al., 1997; goudie & middleton, 2001). during lgm, quartz of saharan origin were deposited in maar lakes of central italy (narcisi, 2000) and the presence of saharan dust in upper pleistocene sediments and soils is also known for the island of sardinia (andreucci et al., 2012), at the same latitude as central italy. according to stuut et al. (2009) the upper horizon of the terra rossa soils in southern europe and peninsular italy (soil zone d1a) is detached from the lower materials because it is made up of saharan dust, while towards the north (soil zone d1b), the material from saharan dust is incorporated in the soil system and serves only to increase the fine silt content. for the italian peninsula, the limit between the soil systems d1a and d1b is indicated at around 42°n, that is the northernmost latitude where the quartz-rich loess has been recognized. the inflow of saharan dust in the mediterranean marine sediments is well known. in the last million years, the influx of saharan dust has been continuous, but during the glacial periods the quantity of dust was appreciably greater (dinarés-turel et al., 2003). late pleistocene saharan dust deposition in the mediterranean is recognized and dated in marine cores (eriksson, 1979; moreno et al., 2002; bout-roumazeilles et al., 2007). the studies carried out on discontinuous stratigraphic successions on the island of lampedusa, midway between sicily (italy) and north africa (giraudi, 2004b), show that loess, formed mainly by quartz of saharan origin, was sedimented at least during the period between 29-28 cal ka bp and 22-21 cal ka bp and during the late holocene. the presence of a higher percentage of quartz of saharan origin during lgm in continuous sediment cores (fig. 5) from the lago di vico and lagaccione, maar lakes in central italy, (reported by narcisi, 2000; 2001; narcisi & anselmi, 1998), confirms the data from marine cores, the changing percentage of quartz being due to north african alternating phases of aridity and humidity. variations of frequency and intensity of southerly winds carrying saharan dust cannot be excluded. the reported data on saharan dust sedimentation in the mediterranean sea and in peninsular italy strongly support the hypothesis that the quartz-rich loess found on the high apennine massifs was formed mainly by saharan dust, also if its mineralogy and grain size do not exclude the possibility of a local contribution. the pollen of african origin, too, studied by magri & parra (2002), shows that winds coming from africa reached the northern mediterranean shores during some of the periods taken into consideration in the present paper. narcisi (2000; 2001) and narcisi & anselmi (1998), highlight that during the late glacial the sedimentation of aeolian quartz greatly decreased. in particular, at lago di vico, the decrease in quartz is dated between 17,866-16,703 and 13,456-12,888 cal a bp, while at lagaccione it occurred between 16,919-15,847 and 14,138-13,645 cal a bp (radiocarbon dates reported in the papers of narcisi (2000; 2001) and narcisi & anselmi (1998) calibrated using the oxcal 4.2 programme). the strong decrease in the quartz of saharan origin in maar lake deposits corresponds to the end of the sedimentation of loess in the apennines (fig. 5). we think that the only alternative hypothesis on the origin of the loess, e.g. from the continental southern italy or from the exposed continental platform, is not reliable. a northern mediterranean origin of the dust can be excluded because the absence of known atmospheric circulation model that can justify the uplift of a great amount of dust at altitude over 2000 m a.s.l. in the southern italy that acted for millennia. if we do not assume a mainly saharan origin of the loess, we would have to justify and to explain, in terms of atmospherical circulation, the absence of saharan dust on the apennine during the lgm and lateglacial. an independent confirmation on the saharan origin of the loess is given by the chronological correlation with the phases of increase and decrease of the aeolian activity in the sahara. the loess sedimented in the apennines during lgm and late glacial, that is during periods of increased aeolian activity in the sahara (fig. 5) reported by demenocal et al. (2000) and swezey (2001). the age of the end of the sedimentation cannot be statistically distinguished from that of the beginning of the african humid period, dated around 14-15 cal ka bp according to gasse et al. (1987), fontes & gasse,1989), gasse et al. (1990), gasse & fontes (1992), cremaschi (1998), demenocal et al. (2000), gasse (2000), cremaschi (2002). in particular, according to demenocal et al. (2000) who studied the aeolian sedimentation in a core taken in the atlantic ocean west of the sahara desert, the african humid period started around 14,850 cal a bp and was synchronous with the 118 late-pleistocene phase of saharan dust deposition in the high apennine mountains (italy) end of glacial conditions in europe and with the end of the heinrich event 1 (h1) in the north atlantic, that is, with the end of the oldest dryas stadial or the end of greenland stadial gs-2. the start of the african humid period therefore matches the age of the end of the apennine loess sedimentation. it is logical to assume that during lgm and late glacial, up to about the end of the oldest dryas stadial, or greenland stadial gs-2, the italian peninsula was affected by circulation of southern air masses carrying greater amounts of saharan dust. the decreased sedimentation of the saharan dust in the italian peninsula was probably conditioned by the expansion of the vegetation cover in the sahara that occurred during the onset of the african humid period corresponding to the start of the bölling interstadial and, perhaps, by the changes in the circulation of air masses. the increase of aeolian sedimentation in the sahara desert and in the atlantic ocean cores which occurred during the younger dryas (gasse et al.,1987; fontes & gasse,1989; gasse et al.,1990; gasse & fontes,1992; demenocal et al., 2000; gasse, 2000; swezey, 2001) was not recorded in the high apennine massifs. in the apennines, it is possible that the colluvial and aeolian reworking of the nyt tephra prevented the formation of a layer of loess rich in quartz, but it is also possible that something changed in the atmospheric circulation and that the intensity and the frequency of the southern currents remained lower after the oldest dryas-bölling transition. 5. conclusions the study of new exposures on mount matese, in which we recognised a quartz-rich loess with interbedded tephra layers, and the search for quartz in proglacial lake sediments of the central apennines, has enabled us to evidence the correlation between sedimentation of the loess and climatic events recorded in the northern hemisphere, and to hypothesize a saharan origin of most of the dust that forms the aeolian deposit. this saharan origin has been proposed according to the mineralogical composition of the loess and to the observed contemporaneity between the sedimentation of loess in central apennine highs and of saharan dust in central italian maar lakes and in the mediterranean sea sediments. the geochemical characterization of three tephra layers and their dating allowed us to establish that the end of the sedimentation of the loess was contemporary with the beginning of the african humid period and took place at the transition between the oldest dryas stadial (or greenland stadial gs-2) and the bölling/alleröd interstadial (or greenland interstadial gl-1). a greater amount of dust, brought by southerly winds, would have been sedimented during glacial stages, corresponding to periods of increased aridity in north africa. although in the sahara there was a later phase of aridity and an increase of aeolian activity during the younger dryas, in the italian peninsula loess deposits are either not distinctively recognisable or not deposited, because, in that period, the aeolian sediments were diluted by volcanic mineral-rich sediments resulting from the reworking of the tephra layers, or because the southern currents never reached the intensity or frequency of the period preceding the bölling interstadial. references andreucci s., bateman m.d., zucca c., kapur s., aksit i., dunajko a., pascucci v. (2012) evidence of saharan dust in upper pleistocene reworked palaeosols of north-west sardinia, italy: palaeoenvironmental implications. sedimentology, 59 (3), 917-938. aufgebauer a., panagiotopoulos k., wagner b., schaebitz f., viehberg f.a., vogel h., zanchetta g., sulpizio r., leng m.j., damaschke m. (2012) climate and environmental change in the balkans over the last 17 ka recorded in sediments from lake prespa (albania/f.y.r. of macedonia/ greece). quaternary international, 274, 122135. blockley s.p.e., ramsey c.b., pyle d.m. (2008) improved age modelling and high-precision age estimates of late quaternary tephras, for accurate paleoclimate reconstruction. journal of volcanology and geothermal research, 177, 251262. bout-roumazeilles v., combourieu nebout n., peyron o., cortija e., landais a., masson-delmotte v. (2007) connection between south mediterranean climate and north african atmospheric circulation during the last 50,000 yr bp north atlantic cold events. quaternary science reviews, 26, 3197-3215. caron b., sulpizio r., zanchetta g., siani g., santacroce r. (2010) the late holocene to pleistocene tephrostratigraphic record of lake orhid (albania). comptes rendus geoscience, 342, 453-466. caron b., siani g., sulpizio r., zanchetta g., paterne m., santacroce r., tema e., zanella e. (2012) late pleistocene to holocene tephrostratigraphic record from the northern ionian sea. marine geology, 311-314, 41-51. chiesa s., coltorti m., cremaschi m., ferraris m., floris b., prosperi l. (1990) loess sedimentation and quaternary deposits in the marche province. in: m. cremaschi (ed) the loess in northern and central italy: a loess basin between the alps and the mediterranean region. quaderni di geodinamica alpina e quaternaria, 1, 103-130. cioni r., marianelli p., santacroce r. (1997) thermal and compositional evolution of the shallow magma chambers of vesuvius: evidence from pyroxene phenocrysts and melt inclusions. journal of geophysical research, 103, 1827718294. cremaschi m. (1990) the loess in northern and central italy: a loess basin between the alps and the mediterranean regions. in: m. cremaschi (ed.) the loess in northern and central italy: a loess basin between the alps and the mediterranean region. quaderni di geodinamica alpina e qua 119 giraudi c. et al 120 ternaria, 1, 15-19. cremaschi m. (1998) late quaternary geological evidence for environmental changes in southwestern fezzan (libyan sahara). in: cremaschi m. & di lernia s. (eds.), wadi teshuinat: palaeoenvironment and prehistory in southwestern fezzan (libyan sahara). all’insegna del giglio, firenze, 13-47. cremaschi m. (2002) late pleistocene and holocene climatic changes in the central sahara. the case of study of the south-western fezzan, libya. in: hassan f.a. (ed.), droughts, food and culture. kluwer academic/plenum, new york, pp. 65-81. deino a., orsi g., de vita s., piochi m. (2004) the age of the neapolitan yellow tuff caldera-forming eruption (campi flegrei caldera italy) assessed by 40ar/39ar dating method. journal of volcanology and geothermal research, 133, 157-170. demenocal p., ortiz j., guilderson t., adkins j., sarnthein m., baker l., yarusinsky m. (2000) abrupt onset and termination of the african humid period: rapid climate responses to gradual insolation forcing. quaternary science reviews, 19, 347-361. dinarès-turell j., hoogakker b.a.a., roberts a.p., rohling e.j., sagnotti l. (2003) quaternary climatic control of biogenic magnetite production and eolian dust input in cores from the mediterranean sea. palaeogeography, palaeoclimatology, palaeoecology, 190, 195-209. eriksson k.g. (1979) saharan dust sedimentation in the western mediterranean sea. in: morales c. (ed.) saharan dust. mobilization, transport, deposition. scope 14. john wiley and sons, new york, 197-210. fett w. (1958) der atmosphärische staub. deutsche verlag der wissenschaften, berlin, 309 pp. fontes j.c., gasse f. (1989) on the ages of humid holocene and late pleistocene phases in north africa remarks on “late quaternary climatic reconstruction for the maghreb (north africa)” by p. rognon. palaeogeography, palaeoclimatology, palaeoecology, 70, 393-398. franzén l.g., hjelmroos m., kållberg p., brorströmlundén e., juntto s., savolainen a-l. (1994) the ‘yellow snow episode’ of northern fennoscandia, march 1991 a case study of long distance transport of soil, pollen and stable organic compounds. atmospheric environment , 28 (22), 3587-3604. frezzotti m., giraudi c. (1990a) late glacial and holocene aeolian deposits and features near roccaraso (abruzzo, central italy). quaternary international, 5, 89-95. frezzotti m., giraudi c. (1990b) sedimenti eolici tardiglaciali ed olocenici nell'appennino centrale. memorie società geologica italiana, 45, 883886. frezzotti m., narcisi b. (1996) late quaternary tephraderived palaeosols in central italy’s carbonate apennine range: stratigraphical and palaeoclimatological implications. quaternary international, 34-36,147-153. gasse f. (2000) hydrological changes in the african tropics since the last glacial maximum. quaternary science reviews, 19, 189-211. gasse f., fontes j.c. (1992) climatic changes in northwest africa during the last deglaciation (167 ka bp). in: the last deglaciation: absolute and radiocarbon chronologies, bard e, broecker w. (eds.). springer, new york, 296325. gasse f., fontes j.c., plaxiat j.c., carbonel p., kaczmarska i., de dekker p., soulié-marsché i., callot y., dupeople p. (1987) biological remains geochemistry and stable isotopes for the reconstruction of environmental and hydrological changes in the holocene lakes from north sahara. palaeogeography, palaeoclimatology, palaeoecology, 60, 1-46. gasse f., téhet r., durand a., gilbert e., fontes j.c. (1990) the arid-humid transition in the sahara and the sahel during the last deglaciation. nature, 346, 141-146. giraudi c. (1997) dating and correlation of glacial deposits using tephra layers and loess: the example of m. matese (campania-molise) southern italy. studia geomorphologica carpathobalcanica, xxxi, 45-56. giraudi c. (1998a) la deglaciazione tardopleistocenica sui m. sirino e pollino (basilicata, calabria-italia meridionale). il quaternario-italian journal of quaternary sciences, 11(2), 247-254. giraudi c. (1998b) the late quaternary geologic evolution of campo felice (abruzzo-central italy). giornale di geologia, 60 (3), 67-82. giraudi c. (1998c) il glacialismo tardo-pleistocenico del massiccio del terminillo (lazio-appennino centrale). il quaternario-italian journal of quaternary sciences,11 (1), 121-125. giraudi c. (2001) i sedimenti di riempimento di piccole conche sulle morene dell’appennino centrale. un contributo alla comprensione delle variazioni ambientali post-glaciali. il quaternario-italian journal of quaternary sciences, 14(2), 131-136. giraudi c. (2004a) the apennine glaciations in italy. in: quaternary glaciations-extent and chronology, part. i: europe, ehlers j, gibbard pl (eds.). amsterdam. elsevier. 215-224. giraudi c. (2004b) the upper pleistocene to holocene sediments on the mediterranean island of lampedusa (italy). journal of quaternary science; 19(6), 537-545. giraudi c. (2011) middle pleistocene to holocene glaciations in the italian apennines. in: developments in quaternary science 15, ehlers j, gibbard pl and hugues pd, (eds.) amsterdam, the nederlands, pp 2011-2019. giraudi c. (2012) the campo felice late pleistocene glaciation (apennines-central italy). journal of quaternary science, 27(4), 432-440. giraudi c., frezzotti m. (1997) late pleistocene glacial events in the central apennine, italy. quaternary research, 48 (3), 280-290. giraudi c., magny m., zanchetta g., drysdale r.n. late-pleistocene phase of saharan dust deposition in the high apennine mountains (italy) (2011) the holocene climate evolution of the mediterranean italy: a review of the geological continental data. the holocene 21(1), 105-115. goudie a.s., middleton n.j. (2001) saharan dust storm: nature and consequences. earth-science reviews, 56(1-4), 179-204. grootes p.m., stuiver m., white j.w.c, et al. (1993) comparison of oxygen-isotope record from the gisp and grip greenland ice cores. nature, 366 (6455), 552-554. guerzoni s., chester r. (1996) the impact of desert dust across the mediterranean. kluwer academic publisher, dordrecht, boston, 389 pp. guerzoni s., molinaroli e., chester r. (1997) saharan dust input to the western mediterranean sea: depositional pattern, geochemistry and sedimentological implications. deep-sea research, 44 (3-4), 631-654. hunt j.b., hill p.g. (2001) tephrological implications of beam size-sample-size effects in electron microprobe analisis of glass shards. journal of quaternary science, 16, 105-117. lane c.s., andric m., cullen v.l., blockley s.p.e. (2011) the occurrence of distal icelandic and italian tephra in the lateglacial of lake bled, slovenia. quaternary science reviews, 30 , 1013-1018. lenaz r., landuzzi v., tomadin l. (1986) apports et concentrations de masse des poussières éoliennes sur le basin oriental et occidental de la méditerranée. memorie della società geologica italiana, 36, 189-200. lowe d.l. (2011) tephrochronology and its application: a review. quaternary geochronology, 6, 107-153. lowe j.j., blockley s., trincardi f., asioli a., cattaneo a., matthews i.p., pollard m., wulf s. (2007) age modelling of late quaternary marine sequences in the adriatic: towards improved precision and accuracy using volcanic event stratigraphy. continental shelf research, 27, 560582. macleod d.a. (1980) the origin of the red mediterranean soils in epirus, greece. european journal of soil science, 31(1), 125-136. magri d., parra i. (2002) late quaternary western mediterranean pollen record and african winds. earth and planetary science letters, 200, 401408. marianelli p., sbrana a. (1998) risultati di misure di standard di minerali e di vetri naturali in microanalisi a dispersione di energia. atti società toscana di scienze naturali memorie, serie a, 105, 57-63. moreno a., canals m., prins m.a., sánchez-goňi m.f., grimalt j.o., weltje g.j. (2002) saharan dust transport and high-latitude glacial climatic variability: the alboran sea record. quaternary research, 58, 318-328. narcisi b. (1999) neapolitan yellow tuff tephra in the lacustrine sediments of the valle di castiglione crater (alban hills). acta vulcanologica, 11, 265269. narcisi b. (2000) late quaternary eolian deposition in central italy. quaternary research, 54, 246-252. narcisi b. (2001) palaeoenvironmental and palaeoclimatic implications of the late-quaternary sediment record of the vico volcanic lake (central italy). journal of quaternary science, 16 (3), 245 -255. narcisi b., anselmi b. (1998) sedimentological investigations on a late quaternary lacustrine core from the lagaccione crater (central italy): palaeoclimatic and palaeoenvironmental inferences. quaternary international, 47/48, 21-28. nihlén t., mattsson j.o., rapp a., gagaoudaki c., kornaros g., papageorgiou j. (1995) monitoring of saharan dust fallout on crete and its contribution to soil formation. tellus, 47b, 365-374. palmentola g., acquafredda p. (1983) gli effetti dei ghiacciai quaternari sulla montagna del matese, al confine molisano-campano. geografia fisica dinamica quaternaria, 6, 117-130. pappalardo l., civetta l., d’antonio m., deino a., di vito m., orsi g., carandente a., de vita s., isaia r., piochi m. (1999) chemical and sr-isotopical evolution of the phlegrean magmatic system before the campanian ignimbrite and the neapolitan yellow tuff eruptions. journal of volcanology and geothermal research, 91, 141-166. prodi f., fea g. (1979) a case of transport and deposition of saharan dust over the italian peninsula and southern europe. journal of geophysical research, 84 (c11), 6951-6960. rapp a. (1984) are terra rossa soils in europe eolian deposits from africa? geol.foren. i stockholm forhanl., 105, 161-168. rapp a., nihlén t. (1991) desert dust storm and loess deposits in north africa and southern europe. catena, 20 (suppl.), 43-55. rellini i., trombino l., firpo m., rossi p.m. (2009) extending westward the loess basin between the alps and the mediterranean region: micromorphological and mineralogical evidences from the northern slope of the ligurian alps, northern italy. geografia fisica e dinamica quaternaria, 32, 103-116. rouis-zargouni i., turon j.l., londeix l., essallami l., kallel n., sicre m.a. (2010) environmental and climatic changes in the central mediterranean sea (siculo-tunisian strait) during the last 30 ka based on dinoflagellate cyst and planktonic foraminifera assemblages. palaeogeography palaeoclimatology palaeoecology, 285 (1-2), 1729. schmidt r., van den bogaard c., merkt j., müller j. (2002) a new lateglacial chronostratigraphic tephra marker for the south-eastern alps: the neapolitan yellow tuff (nyt) in längsee (austria) in the context of a regional biostratigraphy and paleoclimate. quaternary international, 88, 45-56 siani g., sulpizio r., paterne m., sbrana a. (2004) tephrostratigraphy study for the last 18,000 14c years in a deep-sea sediment sequence for the south adriatic. quaternary science review, 23, 121 giraudi c. et al 122 ms. received: april 15, 2013 final text received: october 17, 2013 2485-2500. stuut j.b., smalley i., o’hara-dhand k. (2009) aeolian dust in europe: african sources and european deposits. quaternary international, 198, 234245. sulpizio r., van welden a., caron b., zanchetta g. (2010) the holocene tephrostratigraphy of lake shkodra (albania and montenegro). journal of quaternary science, 25(5), 633-650. svensson a., andersen k.k., bigler m., clausen h.b., dahl-jensen d., davies s.m., johnsen s.j., muscheler r., rasmussen s.o., rothlisberger r., steffensen j.p., vinther b.o. (2005) the greenland ice core chronology 2005, 15-42 ka. part 2: comparison to other records. quaternary science reviews, 25 , 3258-3267. swezey c. (2001) aeolian sediment responses to late quaternary climate changes: temporal and spatial pattern in the sahara. palaeogeography, palaeoclimatology, palaeoecology, 167, 119155. tomlinson e.l., arienzo i., wulf s., smith v.c., carandente a., civetta l., hardiman m., lane c.s., orsi g., rosi m., thirlwall m.t., muller w., menzies m.a. (2012). geochemistry of the campi flegrei (italy) proximal sources for major mediterranean tephras (c-1, c-2, y-3 and y-5). geochimica et cosmochimica acta 93, 102-128. vogel h., zanchetta g., sulpizio r., wagner b., nowaczyk n. (2010) a tephrostratigraphic record for the last glacial-interglacial cycle from lake ohrid, albania and macedonia. journal of quaternary science, 25(3), 320-338 wulf s., kraml m., brauer a., keller j., negendank j.f.w. (2004) tephrochronology of the 100 ka lacustrine sediment record of lago grande di monticchio (southern italy). quaternary international, 122, 7-30. yaalon d.h., ganor e. (1973) the influence of dust on soils during the quaternary. soil science, 116 (3),146-155. zanchetta g., sulpizio r., roberts n., cioni r., eastwood w.j., siani g., caron b., paterne m., santacroce r. (2011) tephrostratigraphy, chronology and climatic events of the mediterranean basin during the holocene: an overview. the holocene, 21(1), 33-52. zanchetta g., giraudi c., sulpizio r., magny m., drysdale r.n., sadori l. (2012) constraining the onset of the holocene “neoglacial” over the central italy using tephra layers. quaternary research, 78, 236-247. late-pleistocene phase of saharan dust deposition in the high apennine mountains (italy) 123 giraudi c. et al 124 late-pleistocene phase of saharan dust deposition in the high apennine mountains (italy) sess 1_160211.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 geomorphological evolution of cagliari coastal plain-continental shelf system to late pleistoceneholocene transition, correlations with stable mediterranean sites paolo orrù 1, fabrizio antonioli 2, salvatore carboni 1 & luciano lecca1 1. dipartimento di scienze della terra, cagliari university, italy 2. enea national agency for new technologies, energy and environment, rome, italy corresponding author: p. orrù <orrup@unica.it > abstract: orrù p. et al., geomorphological evolution of cagliari coastal plain-continental scelf system to late pleistocene-holocene transition, correlations with stable mediterranean sites. (it issn 0394-3356, 2011) we report the evolutionary model of the coastal plain of cagliari and the continental relatively late pleistocene holocene, highlighting the strong linkages with similar coastal areas to its tectonic stability of the mediterranean. riassunto: orrù p. et al., evoluzione geomorfologica del sistema piana costiera-piattaforma continentale di cagliari al passaggio pleistocene superiore-olocene, correlazioni con siti stabili mediterranei. (it issn 0394-3356, 2011) viene presentato il modello evolutivo della piana costiera di cagliari e della piattaforma continentale antistante relativamente alla finestra temporale pleistocene superiore – olocene; ponendo in rilievo le forti correlazioni con altre aree costiere a relativa stabilità tettonica del mediterraneo. key words: last interglacial, coastal plain, continental shelf, holocenic sea levels, cagliari gulf parole chiave: ultimo interglaciale, piana costiera, linee di riva oloceniche, golfo di cagliari two lagoons, closed by a system of beach ridges structured in two generations, characterize the cagliari coastal plain similarly to other areas of the mediterranean (ferranti et al., 2006). in particular, strong similarities in terms of geomorphological evolution and of depositional model are recognized, either in other coastal plains of sardinia (porto pino lagoons in the gulf of palmas and mistras-cabras lagoon in the gulf of oristano) than in other mediterranean coastal areas as the plain of fondi, in central italy (antonioli et al., 1988 ) and in the lagoon of santa pola, alicante in southern spain (zazo et al., 2003). the palaeo inner beach ridges of sa illetta and is arenas have been related to the last interglacial (mis 5e) using: i the senegalese fauna as strombus bubonius; ii the u/th analyses on cladocora corals; iii the aminostratigraphy analyses (ulzega & hearty, 1986). the chronostratigraphic age of the paleo-beach of is arenas (last interglacial) has been recently confirmed using together esr analyses (orrù, et al. 2010), and the malacofauna fossils content which includes strombus bubonius (fig.1). the excavation of the foundations diaphragms of the new port terminal of cagliari allowed us to found continuity for the late-quaternary succession through the system of double beach ridges of the western lagoon system (santa gilla lagoon); (fig.2). the continuity of the section allow us to follow a level containing strombus sampled outcropping on the paleo-beach sa illetta, where the burrows in sandy cliffs are surmounted by a layer containing cladocora caespitosa and calcareous algae (ulzega & hearty, 1986). we describe some new sections of the same level, highlighted on a recent excavation performed at 15 m. on the port access channel, the underwater survey has allowed more detailed facies and fig. 1 – fig.1 – strombus bubonius shell from deposits dradged at – 8,5 m (unit 3 of fig.2), few hundred meters far from the la plaia coast line along the entrance channel to the industrial harbour of cagliari strombus bubonius provenienti dal livello dragato a – 8,5 m (unità 3 in fig.2) in corrispondenza del canale di accesso al nuovo porto conteiner, alcune centinaia di metri al largo del cordone litorale di la plaia. 45 47 46 sedimentary structures. the transition to holocene marine deposits is marked by deep incisions founded in both coastal plain and continental shelf, these palaeo-valley began their evolution after the last interglacial highstand while the highest incision was carved during the mis 2 low stand. chrono-stratigraphic study of sediments,14c analyses of peaty, silty and sandy coastal lagoon sediments at the mouth of the lagoon of santa gilla, has enabled us to reconstruct the sea level rise during the holocene (orrù et al., 2004). geophysical surveys (seismic profile orrù et al., 2004; lecca et al., 2005) allowed to follow the palaeo-valleys (mostly buried) carved during low stand along the continental shelf the main heads of the canyons of the board. (fanucci et al., 1976) the lgm lowstand allowed also in other coastal plains the incision of palaeovalley along the continental shelf as in the fondi fossil palaeovalley (antonioli et al. 1988). the holocene sea level rise has been detected studying and dating (14c analyses): seven orders shelf of beach-rock outcropping on the continental shelf (ulzega et al., 1986) the deepest of lay at -45 m (orrù et al., 2004), relict beach bordered the palaeo-lagoon (-39 m), and in the inner band (-35 m) have recently been identified and sampled the submerged back-shore sand dunes overlayed on a large fluvial fan charatterized by to medium and large polygenic gravels. a buried punic age (2500 bp) paleo-sea level at -2 m is preserved in the bottom-area santa gilla lagoon (solinas & orrù., 2006; antonioli et al., 2007). comparing data from the different markers studied: fossiliferous sediments from boreholes, beachrocks, geoarchaeological markers, appear a good correspondence with the predicted sea level curve (lambeck et al., 2010) which indicates a relatively tectonic stability for the coastal area of cagliari during the holocene. references antonioli f., frezzotti m. & valpreda e. (1988) evoluzione geologica della piana di fondi e delle aree marginali durante il quaternario. memorie descrittive della carta geologica d'italia, xxxviii, 97-124. antonioli f., anzidei m., lambeck k., auriemma r., gaddi, d., furlani s., orrù p., solinas e., gaspari a., karinja s., kovači v. & surace l. (2007) sea level change in italy during holocene from archaeological and geomorphological data. quaternary science reviews, 26, 2463-2486 fanucci f., afierro g., ulzega a., genessaux m., rehault j. p. & kviars de lesegno l. (1976) the continental shelf of sardinia: structure and sedi mentary characteristics. boll. soc. geol. it., 95, 12011217. ferranti, l., et al. (2006) markers of the last interglacial sea-level high stand along the coastal of italy: tectonics implications. quaternary international. 145-146, 30-54 lecca l., demuro s., cossellu m. & pau m. (2005) sedimenti terrigeno-carbonatici olocenici della piattaforma del golfo di cagliari. il quaternario. 18 (2), 202-221. fig. 2, geologic profile of the lagoon of saint gilla 1) grey-greenish sandy silt (middle pleistocene); 2) sandstones and conglomerates with burrows (upper pleistocene mis 5); 3) littoral carenites containg coastal containing strombus bubonius and cladocora coespitosa (late pleistocene – mis 5e); 4) gray silt quartz in fluvial-deltaic peat (late pleistocene-holocene); 5) littoral sandstone containing cerastoderma and sebka beach rock holocenic transgression (holocene); 6) littoral sandy gravel with posidonia peat (late holocene present); 7) blackish silt and sandy silt of the present lagoon; 8) present sandy beach. profilo geologico della laguna di santa gilla. 1) limi argillosi e argille limose deltizie a ostree (pleistocene medio); 2 ) limi sabbiosi ocra a burrows con lenti calcarenitiche (pleistocene superiore – mis 5); 3) arenarie e conglomerati litorali fossiliferi a a strombus bubonius e cladocora coespitosa (pleistocene superiore – mis 5e); 4) limi quarzosi grigi fluviodeltizi e torbe (pleistocene superiore-olocene); 5) arenarie litorali a cardium e beach-rock di sebka perilagunari (olocene); 6) ghiaie e ghiaie sabbiose di spiaggia con livelli torbosi a posidonia oceanica (olocene-attuale); 7)limi e limi sabbiosi nerastri lagunari (olocene-attuale); 8) sabbie di spiaggia (olocene-attuale)  p. orrù et al. 47 ms. received: testo ricevuto il solinas e. & orrù p. e. (2006) santa gilla laguna: spiagge sommerse e frequentazioni di epoca punica, in aequora, pontos, jam, mare. mare, uomini e merci nel mediterraneo antico, genova 9-10 dicembre, atti del convegno internazionale, giannattasio b.m. 249252. orrù p., antonioli f., lambeck k. & verrubbi v. (2004) holocene sea-level change in the cagliari coastal plain (southern sardinia, italy). quaternaria nova, viii, 193-212. orrù p., antonioli f., hearty p.j. & radtke u. (2010) chronostratigraphic confirmation of mis 5 age of a baymouth bar at is arenas (cagliari, italy). quaternary international. in press ulzega a., leone f. & orrù p. (1986) geomorphology of submerged late quaternary shorelines on the s sardinian continental shelf. journal of coastal research, sl 1, 73-82. ulzega a. & hearty j.p. (1986) geomorphology, stratigraphy and geochronology of late quaternary marine deposits in sardinia. zeitschrift für geomophologie n.f., suppl.bd. 62, 119-129. zazo c., goy j.l., dabrio c.j., bardají t., hillairemarcel c., ghaleb b., gonzález-delgado j.a. & soler v. (2003) pleistocene raised marine terraces of the spanish mediterranean and atlantic coasts: records of coastal uplift, sea-level highstands and climate changes. marine geology, 194, 103-133. january 13, 2011 13 gennaio 2011 geomorphological evolution of cagliari coastal ... 02simeone_masucci analisi geoarcheologiche nell’area marina protetta parco sommerso di gaiola (golfo di napoli) maurizio simeone & paola masucci centro studi interdisciplinari gaiola onlus, napoli e-mail: m.simeone@gaiola.org riassunto: m. simeone & p. masucci, analisi geoarcheologiche nell’area marina protetta parco sommerso di gaiola (golfo di napoli). (it issn 0394-3356, 2009). nel presente lavoro si è voluto implementare le conoscenze in campo geoarcheologico sulla fascia costiera di posillipo nel golfo di napoli ed in particolare sull’area attualmente interessata dall’istituzione dell’area marina protetta parco sommerso di gaiola. in questo tratto di costa vi è una notevole concentrazione di strutture archeologiche di epoca romana, molte delle quali attualmente sommerse o semisommerse, anche a causa di locali fenomeni vulcano-tettonici (bradisismo) che interessano ancora oggi l’intera area dei campi flegrei, di cui fa parte la collina di posillipo. incrociando i dati emersi da indagini archeologiche sulle strutture sommerse con quelli desunti da analisi gemorfologiche si sono potute formulare nuove ipotesi sulla variazione relativa del livello del mare (vrlm) in tale area dall’epoca romana ad oggi. data la scarsità di dati bibliografici, la prima fase dello studio è stata dedicata al rilievo e mappatura delle strutture archeologiche sommerse e delle cavità costiere presenti. di grande interesse per la determinazione della vrlm si è dimostrata la presenza di markers archeologici come approdi, cave e peschiere. abstract: m. simeone & p. masucci, geoarchaeological analyses in the marine protected area “gaiola underwater park” (bay of naples). (it issn 0394-3356, 2009). the aim of the present work is to enrich our knowledge in the geoarchaeological field on the coastal strip of posillipo in the bay of naples, and more especially on the area being currently examined by the institution of the marine protected area “gaiola underwater park”. along this tract of coastline there is a considerable concentration of archaeological structures of the roman times, many of which are submerged or semi-submerged, also on account of local volcano-tectonic phenomena (bradyseism) which still affect the entire area of the phlegrean fields, of which the hill of posillipo forms part. by matching the data resulting from archaeological investigations into the submerged structures with those inferred from geo-morphological analyses it has been possible to formulate new hypotheses about relative sea-level variations in that area from roman times to the present day. given the scarcity of bibliographical data, the first phase of the study has been dedicated to surveying the submerged archaeological structures as well as to the geomorphological analyses on the coastal strip both above and below sea level that has also led to surveying the coastal caves present which for the most part are of artificial origin. the presence of archaeological markers such as quays, quarries and fishponds has proved to be very useful for determining in the study area, in roman time, the sea-level was 3m lower than today. parole chiave: archeologia subacquea, bradisismo, golfo di napoli, parco sommerso di gaiola, pausilypon, peschiere romane, variazioni livello del mare. keywords: bay of naples, bradyseism, gaiola underwater park, pausilypon, roman fishponds, sea-level variations, underwater archaeology. il quaternario italian journal of quaternary sciences 22(1), 2009 25-32 1. introduzione la collina di posillipo chiude a nw il golfo di napoli, separandolo da quello di pozzuoli e fungendo da spartiacque tra il settore occidentale ed orientale della città di napoli (fig. 1-b). dal punto di vista geologico rientra nel sistema vulcanico dei campi flegrei, rappresentando l’orlo orientale della caldera originatasi in seguito all’eruzione del tufo giallo napoletano (tgn; 15 ka; deino et al., 2004), roccia di cui è quasi interamente formata, ed al conseguente collasso calderico. dal punto di vista geomorfologico il settore costiero, quasi interamente roccioso, presenta una marcata differenza tra il tratto a ponente delle isole della gaiola, caratterizzato da alte falesie (fino a 150m s.l.m.), ed il tratto a levante dove la collina digrada dolcemente verso il mare (fig. 1-a). proprio questo ultimo tratto di costa, a partire dal i secolo a.c., fu densamente abitato, come ci testimoniano oggi i numerosi resti di epoca romana osservabili lungo la costa sopra e sotto la superficie del mare. tra questi spiccano quelli appartenenti alla villa d’otium del pausilypon, individuabili nell’area che si estende dal promontorio di trentaremi al borgo di marechiaro. fatta erigere dal cavaliere romano publio vedio pollione nel i sec. a.c., entrò a far parte, dopo la sua morte (15 a.c.), dei possedimenti imperiali sotto ottaviano augusto. contrariamente al resto della costa flegrea (pozzuoli, baia, bacoli, miseno), dove la letteratura è ricca di testimonianze storiche e studi specifici sia in ambito prettamente archeologico che in quello geoarcheologico, per quel che riguarda la costa di posillipo, gli studi al riguardo fanno ancora riferimento per molti aspetti al pregevole lavoro di r.t. gunther del 1903, dove non solo vengono eseguiti per la prima volta il rilievo e la mappatura delle strutture archeologiche sommerse lungo la costa ma, sulla base di tali rilievi, viene anche effettuata una stima della variazione relativa del livello del mare (vrlm) (gunther r.t., 1903; 1913). tale stima è stata successivamente rivista prima da jacono nel 1913, e poi dal lavoro di pagano del 1981, impostato principalmente sull’interpretazione di foto aeree. nel presente lavoro si 26 m. simeone & p. masucci è voluto implementare le conoscenze in campo geoarcheologico sull’area mediante acquisizione di nuovi dati. oltre a fornire una nuova mappatura georeferenziata delle strutture archeologiche attualmente sommerse e delle numerose cavità costiere presenti, sulla base dei dati acquisiti, si sono effettuate nuove interpretazioni sulla vrlm dall'epoca romana ad oggi sulla costa di posillipo, fornendo anche basi interpretative sulle origini dell’attuale geomorfologia costiera dell’area di studio in oggetto. 2. materiali e metodi l’area oggetto del presente studio è il tratto di costa, lungo il litorale di posillipo, che si estende dal borgo di marechiaro alla baia di trentaremi, rientrante oggi tra i confini dell’area marina protetta (amp) “parco sommerso di gaiola” (fig. 1-a) istituita con decreto interministeriale del 7/8/2002. la prima fase di studio è stata finalizzata all’elaborazione, in ambiente cad, di una dettagliata mappa georeferenziata di riferimento delle strutture archeologiche sommerse. l’acquisizione dati è stata eseguita mediante rilievi in immersione (ara) sulle strutture precedentemente individuate anche attraverso analisi di foto aeree e ricognizioni “visual census” ad ampio raggio dell’area in apnea. i rilievi hanno interessato le strutture archeologiche sommerse e in generale tutti gli elementi geomorfologici cospicui riconducibili al rimaneggiamento antropico del substrato tufaceo o all’erosione marina (solchi di battente, piattaforme d’abrasione, ecc...). parallelamente, si è effettuato un censimento delle cavità costiere presenti nell’amp fino a 10m di altezza sul livello del mare (s.l.m.) e 5m di profondità, effettuando il rilievo planimetrico di dettaglio delle cavità ritenute più significative dal punto di vista storico e geomorfologico. nella seconda fase, incrociando i dati archeologici con quelli geomorfologici, sono state formulate ipotesi sulla destinazione d’uso delle strutture rilevate e sulla ricostruzione della linea di costa in epoca romana. per quel che riguarda l’utilizzo dei dati archeologici di supporto alla stima della vrlm negli ultimi 2000 anni è stato possibile utilizzare markers come cave, approdi e soprattutto peschiere (tutti presenti nell’area), la cui determinante utilità per fig. 1 a) area di studio: area marina protetta “parco sommerso di gaiola”; b) ubicazione della costa di posillipo nel golfo di napoli; c) sub-area di studio. a) study area: marine protected area “gaiola underwater park”; b) location of posillipo coast in the bay of naples; c) location of study sub-area. questa tipologia di studi nel bacino mediterraneo è stata ampiamente documentata (schmiedt, 1972; pirazzoli, 1976; lambeck et al., 2004; anzidei et al., 2005; marriner & morhange, 2007). i rilievi sono stati effettuati con aste graduate, su profondità inferiori ai 2 metri, profondimetri, per profondità maggiori, e rolline per misure in piano. per la mappatura di strutture distanti più di 10m dalla linea di costa si è utilizzato un gps portatile. simultaneamente all’acquisizione dei dati satellitari mediante gps, si sono sempre acquisiti rilievi a terra mediante bussole da rilevamento, sfruttando punti notevoli presenti sulla costa. tutte le quote acquisite sono state standardizzate mediante l’analisi di dati mareografici e meteorologici, al fine di riportare le quote al livello medio del mare. tutte le fasi di acquisizione dati sono state accompagnate da una sistematica raccolta di documentazione foto e video. 3. risultati in figura 2 viene riportata la mappa realizzata sulla base dei rilievi effettuati sulle strutture archeologiche sommerse e sulle cavità costiere dell’area. dopo un’indagine conoscitiva preliminare, i rilievi si sono concentrati in una sub-area, quasi interamente compresa all’interno della zona a di riserva integrale dell’amp, che si estende dalla cala dei lampi alle grotte di trentaremi interessando circa 8 ha di fondale con una profondità media di -5m (fig. 1-c). in questa zona i fondali sono caratterizzati per il 56% circa da substrato duro, costituito prevalentemente da tufo giallo 27analisi geoarcheologiche nell’area ... napoletano e da depositi piroclastici più antichi (cole et al., 1994), e per la restante parte da sedimento sciolto, per la maggior parte detritico con una grossa componente bioclastica (simeone & russo, 2006). la quasi totalità del substrato duro della sub-area investigata si presenta profondamente rimaneggiato da opere di scavo di epoca romana, finalizzate alla costruzione di approdi, camminamenti, edifici costieri, ma soprattutto vasche e canalizzazioni, per il contenimento ed il ricambio delle acque delle peschiere. le opere murarie spesso fungevano da completamento o innalzamento di elementi architettonici scavati direttamente nella roccia. in taluni casi, infatti, dove le opere murarie non fig. 2 mappa dei rilievi effettuati sulle strutture archeologiche sommerse e le cavità costiere all’interno della sub-area di studio, con l’indicazione della variazione relativa del livello del mare dall’epoca romana ad oggi. nella mappa sono riportate in pianta le sezioni (aa’; b-b’; c-c’) di fig. 3. (restituzione cartografica di m.simeone – c.s.i.gaiola) archaeological relief map on the submerged structures and coastal caves in the study sub-area, with indication of relative sea level change from roman period to today. the map shows the sections (aa’; b-b’; c-c’) of fig. 3 (map elaboration by m. simeone c.s.i.gaiola). 28 sono più in situ, è possibile ricostruire lo sviluppo delle strutture costiere sommerse dall’analisi delle forme intagliate nella roccia. dalla mappa risultano evidenti quattro aree cospicue: a) l’antico porto del pausilypon, con il grande molo foraneo (fig. 2-1, 2, 3), identificabile sui fondali dell’attuale cala dei lampi e cala s.basilio; b) il canale di separazione tra le isole della gaiola e la terraferma; c) il grande sistema di cave di tufo posto a ponente dello scoglio di virgilio, oggi chiamate grotte di trentaremi; d) l’ampia zona di fondali a levante delle isole della gaiola, su cui si sviluppava il complesso sistema di peschiere (fig. 2-5, 6). 3.1. le strutture portuali all’interno della cala dei lampi e di s.basilio, sbocco a mare di due ripidi canaloni di ruscellamento collinari, si nota sulla riva una grande quantità di opere murarie di epoca romana e cavità di discrete dimensioni, nonché una rete di cunicoli, attualmente semisommersi, identificabili come rami di acquedotto (simeone et al., 2007). gran parte di queste strutture assieme a quelle sommerse a pochi metri di profondità all’interno delle due baie adiacenti, facevano parte del porto (fig. 2-1), che molto probabilmente dava accesso da mare al pausilypon, come dimostra la presenza del grande molo foraneo (fig. 2-2), attualmente sommerso, che si estende verso se per ~ 80m ad una profondità costante di -2m. mentre nella parte interna dell’attuale porticciolo il molo emerge per circa 2m dal fondo sabbioso, nella parte esterna emerge per circa 5m mostrando a circa 3m di profondità una marcata concavità nell’opera muraria. dalla fine del molo piegando verso ne si trova una serie di 4 pilae quadrangolari di circa 10x8m di base (opus pilarum) (fig. 2-3) che, elevandosi per circa 5m dal fondale sabbioso, raggiungono una quota variabile dai -2,5 ai -3m. 3.2. il canale della gaiola all’interno del canale, tra grandi opere murarie, identificabili come muraglioni difensivi, camminamenti o banchine, spiccano tre strutture di notevole pregio: l’ambiente con nicchie semicircolari (fig. 2-4), la stanza colonnata (fig. 2-7) e la cosiddetta scuola di virgilio, probabile ninfeo (fig. 2-8). la prima struttura che si incontra all’imbocco del canale, provenendo da est, è un ambiente apparentemente quadrangolare di cui restano in discreto stato di conservazione i due paramenti murari esterni in opus incertum la cui sommità arriva ad appena -0,5m dalla superficie. lungo il margine esterno presenta uno scalino a -1,8m, mentre nella parte interna sono ancora visibili nicchie semicircolari di 2,20m di diametro. lo scalino sul lato di se è a sbalzo, probabilmente a causa del formarsi di un solco d’erosione nell’opera muraria, con limite superiore ed inferiore rispettivamente a -2,5m e -3,3m, e nel tratto terminale verso levante è attraversato da tre fori in successione. all’interno delle nicchie due fori attraversano perpendicolarmente la struttura a -1,5m e -3,3m. poco oltre, all’interno del canale, si incontra una estesa piattaforma in opera muraria a -1,8m, cui si accede dal retrostante banco tufaceo posto a -0,5m mediante tre gradini. anche questa si presenta con un marcato solco di erosione tra -2,5m e -3,3m ed una serie di 8 fori equidistanti lungo il margine a sbalzo (fig. 3-sez. aa’). proseguendo lungo il versante sud si giunge una serie di ambienti addossati al costone roccioso, sormontato nella parte emersa da evidenti tracce di opere murarie romane. tra questi spicca un ambiente di forma rettangolare (7,70x4,80m) alle cui pareti sono addossate sei colonne di 0,4m di diametro, che poggiano su una base quadrangolare di 40x40cm e 70x40cm per le due di fondo (fig. 2-7). il pavimento resta mediamente a -2,50m. più avanti, dove il canale piega a sw si trovano i resti di un probabile ninfeo meglio conosciuto come “scuola di virgilio” (vecchio, 1999), ben visibili nella parte emersa (fig. 2-8). e’ interessante notare che tutto il versante nw del canale, era protetto da un muraglione largo fino a 4m, di cui restano ampie porzioni a soli -0,2m di profondità, posizionato sul ciglio del terrazzamento tufaceo profondo mediamente 2,3m, al cui interno sono state realizzate le strutture descritte. sul versante sud del canale addossati agli isolotti si trovano due grandi ambienti quadrangolari separati dal canale da un’ampia banchina, larga ~ 5m, su cui sono state rinvenute ancora in situ porzioni di basolato di copertura a -1,6m. 3.3. le peschiere certamente all’interno dell’area esaminata ciò che desta maggior interesse, sia da un punto di vista prettamente archeologico, sia in qualità di marker ideale ai fini della stima della vrlm negli ultimi 2000 anni, è proprio l’ampia zona di fondali (circa 9000 m2) su cui si sviluppava il complesso sistema di peschiere, per gran parte realizzato attraverso opere di scavo nell’originario substrato tufaceo. queste vasche per l’allevamento del pesce, che si estendono da ne a sw sulla zona di fondali immediatamente a levante delle isole della gaiola (fig. 2-5,6), erano collegate al mare aperto da complessi sistemi di canalizzazioni e chiuse e difese dall’impeto del mare esterno da possenti mura perimetrali che si elevavano dal basamento tufaceo. all’interno opere murarie di più esigue dimensioni (crepidinae), munite di chiuse e di paratie mobili, separano le vasche tra di loro. il versante nord delle peschiere (fig. 3-sez. aa’) dista dalla sponda opposta del canale circa 15m e presenta ancora tracce del muro perimetrale a -1,6m. superati i resti del muro perimetrale, procedendo verso sud si incontra un canale d’adduzione scavato nel tufo con orientamento ne-sw, ampio 1,2m il cui letto è a 3,8m ed i bordi a -2,5m. il canale, forse in origine completamente coperto, presenta ancora porzioni di copertura e, nel punto dove sfocia all’interno delle vasche, sono ancora ben evidenti, tra i -2,3 ed i -3,5m di profondità, gli alloggiamenti per i piedritti scanalati entro cui scorrevano le paratie mobili (cataractae). sul versante orientale dell’isola di levante si aprono due vasche ipogee semisommerse a pianta trapezoidale (fig. 2-6), che, con una larghezza all’ingresso di 6,6 e 5,5m, penetrano rispettivamente per 15m e 17m in direzione se-nw. presentano volta a botte che si eleva mediamente per 5,5m s.l.m., mentre la profondità all’ingresso è di circa 2,8m.. il fondo delle vasche è oggi colmo di sedimenti e materiale franato, che non permettono di calcolarne la profondità reale. l’intero perimetro interno delle due cavità è percorso da un camminamento in opus latericium a -1,8m che nella vasca sud si presenta rialzato di circa 0,8m nell’angolo m. simeone & p. masucci 29 di sw con due scalini di accesso. all’interno delle due cavità si aprono sul camminamento tre cunicoli attualmente sommersi di 1,5x1,5m, di cui uno mette in comunicazione le due cavità e gli altri due collegano ciascun ipogeo con il canale di separazione tra le due isole. le due vasche ipogee si affacciano su di un’ampia vasca esterna rettangolare cinta da un paramento murario in opus incertum, alto 2,5m che sul lato orientale si eleva da un fondale di -4,5m (fig. 3-sez. bb’). lungo il perimetro di tale vasca sono visibili due chiuse di collegamento: una sul lato di sw per paratia mobile, di cui restano solo i piedritti scanalati, ed una sul lato di ese, delle dimensioni 80x80cm (fig. 3-b), recante ancora all’interno una lastra traforata per consentire il ricambio delle acque trattenendo il pesce, così come descritto anche da columella (de re rustica, viii). trattasi in questo caso di una paratia fissa imprigionata nella muratura a circa 0,3m dalla base del muro. a ~13m fig. 3 sezioni indicate in pianta nella fig. 2 con l’indicazione del livello del mare attuale (lma) e di quello stimato in epoca romana (lmr). b) foto del muro perimetrale della vasca esterna alle peschiere ipogee, con l’indicazione delle quote significative. (foto g.villani). sections indicated in fig. 2, with indication of present sea level (lma) and estimated roman sea level (lmr). b) hypogean fishponds: picture of eastern wall of the outside pool, with indication of significant heights. (photo g. villani). analisi geoarcheologiche nell’area ... 30 verso est, il banco di tufo da cui affiorano i due isolotti di levante, si presenta nella parte sommersa completamente squadrato ad angoli vivi con ampi gradoni sul lato di ponente (fig. 3-sez. bb’) ed un profondo sbancamento rettangolare nella parte mediana solcato da un altro canale d’adduzione. il settore di vasche che si estende verso sud presenta ampi muri perimetrali la cui parte inferiore è ricavata direttamente nel tufo (fig. 3-sez. cc’). di particolare interesse è il canale per la regimentazione delle acque realizzato lungo il margine di se. largo mediamente 1,5m internamente e 7,5m esternamente, con una profondità media di -4,5m al letto e di -2m al tetto, si sviluppa in direzione ne-sw per una lunghezza di circa 80m. trasversalmente al canale principale si diparte una serie di chiuse rivolte verso l’interno (nove) e verso l’esterno (tre ancora visibili) delle vasche. questo sistema binato di chiuse fu descritto anche da jacono (1913) a proposito delle peschiere di formia, interpretandolo come sistema atto ad evitare l’ingresso del mare in burrasca direttamente all’interno delle vasche, e ciò spiegherebbe quindi anche l’imponenza degli argini del canale più spessi verso il mare aperto (3,5 4m). 3.4. le cavità costiere le indagini sulle cavità costiere hanno portato al censimento di 36 cavità, di cui 12 cunicoli, quasi tutte di origine artificiale (simeone et al., 2007). per gran parte di queste è stato possibile eseguirne i rilievi planimetrici di dettaglio (fig. 2). tra queste rivestono particolare interesse ai fini della presente trattazione le peschiere ipogee, di cui si è sopra trattato, e le cosiddette “grotte di trentaremi”, un esteso sistema di cavità costiere che si estende per circa 2800m2 sotto il promontorio di trentaremi (fig. 4). di queste, due sono navigabili (fig. 4-t1, t5), con una profondità del mare all’interno che varia dai 4 ai 6m, ed hanno molto probabilmente un’origine naturale (simeone et al., 2007), mentre le altre, con gran parte del piano di calpestio ad una quota di poco superiore al livello medio di marea, sono il frutto di secoli di attività estrattiva, che ha profondamente alterato la geomorfologia costiera dell’intera area (fig. 4t2, t3, t6). anche le estese piattaforme rocciose, oggi semiaffioranti, che dal costone roccioso si protendono nel mare (fig. 4-p), sono ciò che resta dell’antico promontorio prima che i cavatori ne asportassero la parte emersa. non si hanno dati certi sul periodo in cui questa attività ebbe inizio, ma è noto che si protrasse fino al 1870 (segre & segre, 2004). le testimonianze archeologiche osservabili lungo la costa ci parlano di aree edificate molto estese già a partire dal i sec a.c. (gunther, 1913) che potrebbero far supporre la richiesta di materiale edilizio disponibile e facilmente trasportabile via mare nelle immediate vicinanze. la sezione trapezoidale suggerirebbe, inoltre, un’origine greca fig. 4 particolare del rilievo delle cavità costiere del promontorio di trentaremi con le piattaforme esterne semiaffioranti (p); foto della falesia e grotte di trentaremi con indicazione dei solchi d’erosione (6m, 9m) e particolari degli ingressi delle cavità t1 e t3. (foto m. simeone). detail of relief map of trentaremi caves, with external half-emerging platforms (p); pictures of cliff and trentaremi caves with indication of erosion notches (6m, 9m) and details of t1 and t3 caves entrances. (photo m. simeone). m. simeone & p. masucci degli scavi (fig. 4), ma gli interventi successivi sull’intero costone roccioso hanno certamente alterato qualsiasi impianto di cava originario. nella cavità t-3 una delle ramificazioni interne intercetta, spezzandolo in due tronconi di 17 e 66m, un cunicolo di acquedotto romano, che risalendo in direzione nord-est conduce, poco prima di terminare in una colmata di materiale terrigeno, ad un ambiente soprastante di 53m2 (t-4), identificabile come cisterna (simeone et al., 2007). e’ evidente, quindi, che nel momento in cui fu realizzato tale ramo di cava, l’acquedotto romano non doveva essere più in uso. un ultimo elemento da considerare sono i solchi orizzontali che incidono l’intera falesia (fig. 4) penetrando all’interno delle cavità. il primo solco è individuabile ad una quota di circa 6m s.l.m., mentre il secondo, più ampio rispetto al primo è a circa 9m. per quanto riguarda il primo solco l’andamento ad onda farebbe ipotizzare la formazione dello stesso per erosione selettiva dello strato in ambiente sub-aereo. tale solco quindi non appare relazionabile al solco di battente visibile a circa 5m sui costoni tufacei del settore occidentale della costa di posillipo e sui resti di strutture archologiche emerse, la cui presenza è stata già verificata in passato oltre che dallo stesso gunther (1913), anche più recentemente da flemming (1969) e russo (2004). quasi certamente tale solco di battente sulla falesia di trentaremi non è più visibile a causa delle opere di cava. più simile ad un solco di battente appare quello che taglia la falesia a circa 9m s.l.m., ma per accreditare tale dato, di cui non se ne fa menzione in letteratura, è certamente indispensabile un approfondimento di indagine. 4. conclusioni i risultati del presente lavoro, confermano la grande rilevanza dell’area di studio, attualmente racchiusa tra i confini dell’amp parco sommerso di gaiola, sia in ambito prettamente archeologico che geoarcheologico. i nuovi rilievi eseguiti hanno permesso di avere un quadro dettagliato delle strutture archeologiche sommerse che interessano l’area nonché delle numerose cavità costiere presenti, per lo più di origine antropica. la presenza nella stessa area di markers archeologici importanti come approdi, cave costiere e soprattutto peschiere, è stata fondamentale ai fini della stima della vrlm dall’epoca romana ad oggi. di notevole interesse, inoltre, la complessità geomorfologica dell’area, frutto dell’interazione tra modificazioni antropiche del substrato tufaceo, movimenti vulcano-tettonici ed erosione marina. dalle quotature effettuate sulle peschiere, ed in particolare sui canali d’adduzione, le crepidini e le chiuse, si è stimato che il livello del mare in epoca romana fosse di circa 3m più basso rispetto a quello attuale (fig. 2; fig. 3). considerando, che la vlm negli ultimi 2000 anni, dovuta alla componente eustatica ed isostatica (glacio-idro isostatica), in aree tettonicamente stabili del mediterraneo centrale, è stata stimata tra +0,50m (pirazzoli, 1976) e +1,35m (lambeck et al., 2004), risulta evidente che una grossa componente della vrlm nell’area di studio è dovuta a fenomeni vulcano-tettonici locali (bradisismo flegreo). tale stima è stata successivamente verificata mediante le quotature effettuate sulle altre strutture marittime rilevate nell’area come approdi, moli e banchine presenti nell’area del canale della gaiola, di cala s.basilio e cala dei lampi. in particolare, riportando la quota stimata di -3m sulle strutture portuali (fig. 2-1, 2), si riscontra che le banchine dell’approdo, così come le banchinature interne al canale, emergevano dal mare per circa 1m, in accordo con quanto ipotizzato da blackman (1973). la piattaforma ribassata rispetto al costone tufaceo retrostante presente di fianco all’ambiente dalle nicchie semicircolari, potrebbe essere stata costruita proprio per consentire un più facile approdo sul versante nord del canale. anche i solchi d’erosione rilevati in più punti tra i -2,5 e -3,5m di profondità potrebbero essere stati causati dall’antico battente d’onda. questa nuova stima della vrlm da 2000 anni ad oggi per la fascia costiera di posillipo, proposta nel presente lavoro, si discosta dalle stime fino ad oggi proposte, comprese tra i + 4m (pagano, 1981) ed i + 4,9-6m (gunther, 1903; 1913), aprendo scenari notevolmente diversi per quel che riguarda la ricostruzione della linea di costa in epoca romana, molto più simile, quindi, a quella attuale (fig. 2). un esempio è rappresentato dalle stesse isole della gaiola, che, in base alle stime precedenti, nel i sec a.c. risultavano far parte della terraferma, mentre alla luce del presente studio, si può affermare che anche in quel periodo le isole erano separate dalla terraferma da un canale navigabile. anche la presenza di solchi di battente compresi tra i -2,5 e -3,3m all’interno delle strutture rilevate ai margini del canale confermerebbe questa tesi. proprio dall’analisi della caratterizzazione geomorfo-archeologica emersa e sommersa della zona del canale, si può arrivare ad affermare che lo stesso canale della gaiola sia di origine artificiale, frutto anch’esso di opere di scavo di epoca romana. considerando che l’attuale variazione relativa del livello del mare nei campi flegrei è il risultato di diverse fasi di innalzamento ed abbassamento della linea di costa imputabili al fenomeno del bradisismo (parascandola, 1947; cinque et al., 1991; dvorak & mastrolorenzo, 1991; morhange et al., 2006) e accreditando l’ipotesi di un solco di battente a circa 5m di altezza sull’attuale livello del mare si dovrebbe considerare una sommersione massima della costa di circa 8m dall’epoca romana ad oggi. la presenza di un ulteriore solco di battente a + 9m è ancora oggetto di verifica, ma è interessante notare che se tale dato fosse accreditato, la sommersione massima sarebbe di circa 12-13 m, del tutto simile a quanto riscontrato sul margine opposto della caldera flegrea nell’area misenate (cinque et al., 1991), dove però attualmente i resti degli approdi romani sommersi sono a circa -7-8m di profondità (caputo, 1989; dvorak & mastrolorenzo, 1991). interessante è anche il confronto con l’area puteolana dove dall’epoca romana lo sprofondamento massimo della costa è valutabile intorno ai 17m e la variazione relativa del livello del mare rispetto ad oggi è di circa 10m (segre, 1972; sgobbo, 1977; de pippo et al., 1984; dvorak & mastrolorenzo, 1991; morhange et al. 2006). al momento, ulteriori indagini sono in corso sia all’interno del perimetro dell’amp, che nelle aree limitrofe, nel tentativo di acquisire nuovi elementi che possano approfondire le conoscenze geoarcheologiche sul settore costiero napoletano, in generale, e sulla fascia costiera di posillipo in particolare. 31analisi geoarcheologiche nell’area ... ringraziamenti si ringrazia l’ente gestore dell’amp parco sommerso di gaiola (soprintendenza speciale per i beni archeologici di napoli e pompei) per la disponibilità sempre concessa al c.s.i.gaiola onlus nello svolgimento delle proprie attività di ricerca. si ringrazia il dott. guido villani per il prezioso contributo fotografico subacqueo alle ricerche. bibliografia anzidei m., benini a., lambeck k., antonioli f., esposito a., surace l. (2005) siti archeologici costieri di età romana come indicatori delle variazioni del livello del mare: una applicazione al mare tirreno (italia centrale) in de maria l. y turchetti r., eds evolucion paleoambiental de los puertos y fondeaderos antiguos en el mediterraneo occidental. rubbettino, rome, pp. 115-126. blackman d.j. (1973) evidence of sea level change in ancient harbours and coastal installations marine archaeology. butterworths, london, pp. 115-139. caputo p. (1989) attività di tutela della soprintendenza archeologica di napoli e caserta atti ii conv. naz. archeologia subacquea, roma. cinque a., russo f., pagano m. (1991) la successione dei terreni di età post-romana delle terme di miseno (napoli): nuovi dati per la storia e la stratigrafia del bradisisma puteolano boll. soc. geol. it., 110, pp. 231-244. cole p.d., perrotta a., scarpati c. (1994) the volcanic history of the southwestern part of the city of naples geological magazine, 131 (6), pp. 785799. columella l.g.m. de re rustica, liber viii. deino a.l., orsi g., de vita s., piochi m. (2004) the age of the neapolitan yellow tuff caldera-forming eruption (campi flegrei caldera italy) assessed by 40ar/39ar dating method journal of volcanology and geothermal research, 133, pp. 157-170. de pippo t., di cara a., guida m., pescatore t., renda p. (1984) contributi allo studio del golfo di pozzuoli: lineamenti di geomorfologia mem. soc. geol. it., 27, pp.151-159. dvorak j.j. & mastrolorenzo g. (1991) the mechanism of recent vertical crustal movements in campi flegrei caldera, southern italy geological society of america special paper, 263, 47 p. flemming n.c. (1969) archaeological evidence for eustatic change of sea level and earth movements in the western mediterranean during the last 2000 years geological society of america special paper, 109, 125 p. gunther r.t. (1903) contributions to the study of earth-movements in the bay of naples oxford, parker and son rome, e. loescher and co. gunther r.t. (1913) pausilypon. the imperial villa near naples oxford university press, oxford. jacono l. (1913) note di archeologia marittima. neapolis, pp. 353-371. lambeck k., anzidei m., antonioli f., benini a., esposito a. (2004) sea level in roman time in the central mediterranean and implications for recent change. earth and planetary science letters, 224, pp. 563-575. marriner n., morhange c. (2007) geoscience of ancient mediterranean harbours earth science reviews, 80, pp. 137-194. morhange c., marriner n., laborel j., todesco m., oberlin c. (2006) rapid sea-level movements and noneruptive crustal deformations in the phlegrean fields caldera, italy geological society of america bulletin, 34 (2), pp. 93-96. pagano m. (1981) gli impianti marittimi della villa pausilypon puteoli. studi di storia antica, iv-v, pp. 245-255. parascandola a. (1947) i fenomeni bradisismici del serapeo di pozzuoli genovese, napoli. pirazzoli p. (1976) sea level variations in the northwest mediterranean during roman times sciences, 194, pp. 519-521. russo f. (2003) i depositi marini olocenici nei campi flegrei: testimonianze di una evoluzione geomorfologia complessa in albore livadie c. & ortolani f. variazioni climatico-ambientali e impatto sull’uomo nell’area circum-mediterranea durante l’olocene edipuglia, bari. schmiedt g. (1972) il livello antico del mar tirreno: testimonianze dei resti archeologici l.s. olschki, firenze. segre a.g. (1972) la carta batimetrica n. 1256 i.i. del golfo di pozzuoli ist. idrogr. della marina, genova. segre a.g. & segre a.f. (2004) storie e ricordi della gaiola atti accademia pontaniana, napoli, n.s. 52, pp. 243-267. sgobbo i. (1977) i templi di baia accad. naz. dei lincei, roma, atti, pp. 283-328. simeone m. (2004) analisi territoriale per una gestione integrata della fascia costiera di posillipo tesi di laurea, università parthenope di napoli, italy. simeone m., russo g.f. (2005) il parco sommerso della gaiola in carrada g.c., coiro p., russo g.f. le aree marine protette. i quaderni di uomo e natura, 2, pp. 85-94 electa napoli. simeone m., russo g.f. (2006) posillipo ed il parco sommerso di gaiola (golfo di napoli): analisi del sistema ecologico costiero abstract del v convegno nazionale conisma, viareggio, p. 50. simeone m., masucci p., pagliarani a. (2007) le cavità costiere dell’area marina protetta parco sommerso di gaiola (golfo di napoli) in del prete s., maurano f. (ed.) atti i convegno regionale di speleologia “campania speleologica”, 1-3 giugno 2007, oliveto citra (sa), italy, pp. 241-249. vecchio g. 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<feff4f7f75288fd94e9b8bbe7f6e521b5efa76840020005000440046002065876863ff0c5c065305542b66f49ad8768456fe50cf52068fa87387ff0c4ee575284e8e9ad88d2891cf76845370524d6253537030028be5002000500044004600206587686353ef4ee54f7f752800200020004100630072006f00620061007400204e0e002000520065006100640065007200200035002e00300020548c66f49ad87248672c62535f0030028fd94e9b8bbe7f6e89816c425d4c51655b574f533002> /cht <feff4f7f752890194e9b8a2d5b9a5efa7acb76840020005000440046002065874ef65305542b8f039ad876845f7150cf89e367905ea6ff0c9069752865bc9ad854c18cea76845370524d521753703002005000440046002065874ef653ef4ee54f7f75280020004100630072006f0062006100740020548c002000520065006100640065007200200035002e0030002053ca66f465b07248672c4f86958b555f300290194e9b8a2d5b9a89816c425d4c51655b57578b3002> >> >> setdistillerparams << /hwresolution [2400 2400] /pagesize [595.000 842.000] >> setpagedevice microsoft word 00_indice_bm03 available online http:/amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 25 (1), 2012, 5-14 local glaciers in the julian prealps (ne italy) during the last glacial maximum giovanni monegato c.n.r. institute of geosciences and earth resources, torino, italy corresponding author: g. monegato <g.monegato@csg.to.cnr.it> abstract: the prealpine range of the eastern southern alps includes many high-elevation (up to 1900 m) massifs, whose northern slopes contain glacial deposits. on the northern side of the chiampon-cuel di lanis ridge (julian prealps) five different mountain moraine systems are sited; these are related to local glaciers, which were independent from the major tagliamento glacier during the last glacial maximum (lgm). their length was slightly more than 3 km, with lateral moraines developed along the lower part of the deep valleys. their terminal moraines occur from 490 m to 650 m a.s.l. clast petrography of the carbonate-rich till clearly establishes a local provenance, distinct from that of the tagliamento catchment. inferences from geomorphological parameters, such as elevations of the valley floor and of the lateral moraines, as well as the extent of the accumulation area, indicate a thickness of the glaciers, ranging from 130 to 230 m in the accumulation areas. application of the altitude x area balance-ratio (aabr) formula provides an ela estimate of 1130 to 1200 m a.s.l. this is in agreement with the atmospheric circulation models of the lgm for the eastern alps, which indicate an ela depression, below 1300 m a.s.l., related to higher precipitation rates than the rest of the alpine chain. keywords: julian prealps, lgm, glacial deposits, ela, paleoglaciology. 1. introduction the prealpine sectors of the alps provide important climatic information for the last glacial maximum in the alpine chain, because, in those sectors, local glaciers can be distinguished from the major valley glaciers, which were directly fed from the ice caps (kelly et al., 2004). the presence of cirque glaciers around the highest prealpine massifs during the lgm has been documented by several authors enabling estimation of the equilibrium line altitude (ela) of glaciers during the last glaciation (e.g. carraro & sauro, 1979; van husen, 1997; federici & pappalardo, 2010; forno et al., 2010). according to recent models (i.e., kuhlemann et al., 2008, 2009), ela along the southern side of the alps is depressed in the east, descending below 1300 m a.s.l. in correspondence of the eastern southern alps during the peak of the lgm (around 23 ka bp). these estimates are 1200 m to 1500 m lower than little ice age (lia) values (ivy-ochs et al., 2008). in the studies of the local glacialism in the venetian-friulian prealps, the ela of the last glaciation was assessed at around 1400 m a.s.l. (desio, 1926; fuchs, 1970; carraro & sauro, 1979; orombelli et al., 2004) and 1350 m for baratto et al. (2003), about 1200 m below the little ice age ela in the dolomites (masini, 1998). this paper describes the local glacial activity during the lgm in the julian prealps, at the southeastern margin of the alpine chain. this part of the chain was included in the geological survey at the scale 1:10.000 for the “gemona del friuli” sheet (scale 1:50.000) of the new italian geological map project (zanferrari et al., in press). this new data enables the estimation of the ela in this part of the chain providing new perspectives on the advance of the major glaciers, which reached the piedmont plain (castiglioni, 2004; monegato et al., 2007). 2. setting the julian prealps are located in the outer sector of the alpine chain between the julian alps (fig. 1), at the italian-austrian-slovenian borders, and their junction with the northern dinarides. the prealps do not exceed 2000 m a.s.l., reaching their maximum elevation of 1958 m a.s.l. at plauris mount. the julian prealps are characterised by a series of long ridges trending wnw-ese. their southern slopes are very steep, with cliffs of 10001300 m (fig. 2), while northern slopes are gentler, except for steep headwalls in the highest cirques. on the southern sides very small cirques are present at the highest elevations; while on the northern sides the cirque depressions are wide and well developed (fig. 3). the main massifs characterising the italian side are the chiampon-cuel di lanis and the gran monte chains, which can be considered a continuous ridge cut by the torre valley, to the south, and the musi chain and the plauris-lavara massif, to the north (fig. 2). the two ridges are separated by the torre valley to the east, whose drainage is included in the isonzo river catchment, and the venzonassa valley to the west. the venzonassa stream is an eastern tributary of the tagliamento river (fig. 2). the distribution of the glacial deposits in the musi chain and the plauris-lavara massif indicates that the local glaciers merged into the major tagliamento-fella glacier (zanferrari et al., in press). this valley glacier spread out in the piedmont plain forming a wide end moraine system; several radiocarbon datings allowed to ascribe the glacial amphitheatre to the lgm (monegato et al., 2007). following the lateral moraines upstream along the valley, as well as paraglacial deposits related to the slope degradation, the elevation of the tagliamonegato g. 6 fig. 2 digital terrain model of the julian prealps and the lower valley of the tagliamento river. mento glacier sideway of the julian prealps was between 600-650 m a.s.l. this indicates that the ice stream hardly crept into the venzonassa valley and not from ledis fork, which is at 752 m a.s.l. for these reasons, the glaciers related to the chiampon cuel di lanis and the gran monte chains were separated from the valley glacier and set several small end moraine systems in the lower part of the northern slopes. the glacial deposits related to the julian prealps were thoroughly described, for the musi chain and the plaurislavara massif, in early studies (desio, 1926; gortani & desio, 1927); but the southern relieves have received only cursory attention (feruglio, 1925, 1953). the glacial deposits were ascribed mostly to the würmian glaciation (sensu penck & brückner, 1901-1909), while older glacial units were not recognized. previous reconstructions of the lgm extent have indicated local glaciation in the julian prealps (castiglioni, 1940; vai & cantelli, 2004) or a complete ice cover in the area (venturini, 2003; ehlers & gibbard, 2004). 3. distribution of the glacial deposits the morphology of the northern side of the chiampon-cuel di lanis ridge is characterized by five large cirques, whose headwall is represented by the crest of the ridge (fig. 3a). these natural amphitheatres are roughly 1 km wide, with elevation ranging from 1500 m at the highest point (northern side of the chiampon mount) to 1400 m for the others. in this portion of the drainage, most glacial deposits are buried beneath talus. downslope, the valleys become steeper and the glacial deposits are located along the thalweg. these deposits consist of massive matrixsupported diamicton, rich in striated subangular pebbles and normally consolidated. the matrix is normally silty (fig. 4). this facies, identifiable as lodgement till, is visible in several locations from 800 m to 1100 m a.s.l., typically within stream incisions. at about 700-900 m a.s.l. the lateral moraines are clearly distinguishable in all the valleys. they are composed of matrix to clast-supported diamicton, with a matrix of silty sand. clasts are normally angular to sub-angular and striated. some big boulders, up to 1 m in diameter, are present within the sediment and at the top of the moraine ridges. the moraines are typically about 30 m high; though, the ridge of vodizza, on the eastern side of the complex towards the torre valley (fig. 5), is 100 m high. along the central valley (locality called bombasine), a more organized, crudely bedded diamicton can be recognized within a gorge. meter-sized angular boulders (fig. 6a) are embedded within this poorly consolidated deposit, which appears to be a flow-till. in this sector the glacial deposits flowed into the main venzonassa valley, at 490 m a.s.l. the low elevation and the rough bedding of the till would suggest subacqueous processes. nevertheless, no glacio-lacustrine facies were recognized. westwards, the pozzus valley is characterized by well developed end moraines (fig. 6b), whose front is cut by the headwall erosion of the present creek; here the transition to proximal fluvioglacial deposits crop out. the western sector (moeda valley) is characterised fig. 1 location of the study area (black box) at the alps/dinarides junction greyshaded area represents the relief above 500 m.. local glaciers in the julian prealps (ne italy) during the last glacial maximum 7 by widespread poorly consolidated deposits. these are matrix-supported and rich in angular to sub-angular clasts, which are commonly striated. moraines are preserved on the southern side of the valley, while to the north they are buried by talus deposits. in front of the glacial deposits matrixto clastsupported gravels are present. their bedding becomes increasingly more clear downstream, until crude bedding, rich in sandy matrix, appears. this deposits probably originated as fluvioglacial sediments, deposited by outwash currents in the proximal reach of the valley. it filled a palaeo-incision of moeda creek, which now is entrenched within the triassic dolostones, upstream of the junction with the venzonassa stream. all of the outcropping glacial deposits and the related fluvioglacial sediments derive from the chiamponcuel di lanis massif. no exotic clasts from the wider tagliamento catchment were found in these sediments. moreover, at ledis fork (752 m a.s.l.) no glacial deposit related to the tagliamento glacier are preserved, either. downstream, in the distal reach of the venzonassa valley, approximately 20 m of crudely bedded to horizontally bedded deposits are present at about 500 m a.s.l. these deposits are clast-supported, clasts are sub-angular to sub-rounded. sandy matrix is common and fills the voids. this material must have derived from the fluvioglacial collector of the entire chiampon-cuel di lanis system, upstream from the junction with the tagliamento glacier. a series of small circular moraines are located at about 1150 m a.s.l. in the scric, pozzus, and bombasine valleys. the moraines are about 10 m high and composed of coarse clast-supported diamicton, in which most clasts are angular. the deposits are weakly consolidated and in some localities only represented by scattered blocks on the outcropping bedrock. at higher elevation, around 1400 m a.s.l., another series of small terminal moraines are visible around the chiampon mount and cuel di lanis. these moraines are composed of angular blocks, with scarce sandy matrix. a) b) fig. 3 a) picture of the southern slope of the chiampon – cuel di lanis ridge from the top of cuarnan mount. b) picture of the northern slope from casera ungarina, in which the five deep valley are evidenced. fig. 4 matrix-supported till, with striated clasts, cropping out in bombasina valley. monegato g. 8 4. palaeoglaciers reconstruction to reconstruct the geometry of the maximum extension of the palaeoglaciers that flowed down the northern slopes of the chiampon-cuel di lanis ridge, morphological parameters measured in the field, such as elevation of the valley floor and of the lateral moraines, provided key variable values for the spreadsheet equations of benn & hulton (2010). an average shear stress value of 100 kpa, a standard value for glacier motion on a rigid basal bedrock (bennet & glasser, 2009), was used for these calculations. the results point to different dynamics and geometries between these glaciers (figs. 7-8). the western glaciers (namely: scric, moeda and pozzus) have an unusual morphology in their highest portions, in which accumulation normally occurs. for these glaciers, this sector is characterised by a steep gradient above 1100-1200 m, which would normally be 1.5 to 3.5 less steep than the ablation gradient (see carr et al., 2010 for discussion). this suggests systems dominated by avalanche accumulation below this elevation, as is found in cirque glaciers (bennet & glasser, 2009). the thickness of the glaciers exceeded 100 m only below this elevation. on the other hand, the eastern glaciers (bombasine and vodizza) show the expected gentler slope in the highest area, above 1200 m, which allowed the accumulation of ice exceeding 200 m in thickness in the bombasina glacier (fig. 7). all of the calculated ice surfaces are roughly in agreement with the preserved elevation of the respective end moraine systems. 5. the equilibrium line altitude the equilibrium line altitude (ela) is a common parameter inferred from geomorphological analysis of a glaciated basin and is useful for palaeoclimatic recostructions (e.g. ohmura et al., 1992; benn & lehmkuhl, 2000). the calculation of the ela represents a decades-long refinement of less precise methods, such as the thar (toe-headwall area ratio) or the aar (accumulation area ratio). those methods do not take into consideration the hypsometry of the former fig. 5 panoramic view of the vodizza end moraine systems, top of the ridges evidenced by black arrows. fig. 6 a) organized diamicton in the lower bombasina valley; b) lateral end-morainic ridge in the pozzus valley. local glaciers in the julian prealps (ne italy) during the last glacial maximum 9 glaciers. this parameter was included in the calculations of the aabr (area altitude balance ratio) method (furbish & andrews, 1984) and tested on modern alaskan glaciers. subsequently spreadsheets were developed to facilitate rapid calculations (benn & gemmell, 1997; osmaston, 2005) and tested for modern (rea, 2009) and ancient glaciers (benn & ballantyne, 2005; federici et al., 2012) with good results. in addition, a program was made available, recently, for reconstructing the surface profile of ancient glaciers (benn & hulton, 2010), which is an important advance in characterizing ancient glaciations. ela palaeo reconstructions for long periods as the lgm have to take into account a zero net balance ela (sensu rea, 2009) in equilibrium conditions, with mass balance equal to zero (osmaston, 2005; carr & coleman, 2007). this hypothetical condition is essentially, but no matches with the historical studies on the present glaciers, which evidenced that the measured ela oscillated even for some hundreds of meters in few decades (e.g., benn & lehmkuhl, 2000). using field parameters to estimate the thickness of the study glaciers, the aabr method (osmaston, 2005; rea, 2009) yielded an average balance ratio for this mountain ridge, that could be compared to predicted alpine values on modern glaciers (rea, 2009). contour belt intervals of 100 m were used for this numerical sim fig. 7 longitudinal profiles of the palaeoglaciers calculated after benn & holms (2010) spreadsheet. monegato g. 10 ulation. the results are reported in table 1. according to aar method, the values of scric-moeda and pozzus paleoglaciers are slightly lower than those calculated for the alpine region (rea, 2009; federici et al., 2012). moreover, also aabr ratios are slightly lower than the 1,91 average of modern alpine glaciers (rea, 2009). in the study area, the eastern glaciers (vodizza and bombasine) had an estimated steady-state lgmela around 1130-1180 m a.s.l., which is related to the wider and less steep accumulation areas, respectively of 1.026 and 3.166 km2. here, the thickness of the glacier reached 230 m, the highest value for the system. the central pozzus palaeoglacier had a different morphology, with the highest gradient in the accumulation area reaching 35° (fig. 7). it is noteworthy that this glacier reached a greater thickness (from 800 m to 1000 m a.s.l.) corresponding to the change in the width of the valley, suggesting a different mechanism of accumulation than the eastern glaciers. for this glacier, the calculated ela is about 1145 m a.s.l. the western paleoglaciers, originated in the common accumulation area of the chiampon mount and were separated into two lobes, the moeda and scric lobes (fig. 8). for this system the thickest portion of the glacier reached 100 m. the eastern moeda lobe flowed down a steep upper valley and, as in the pozzus valley, thickest ice occurred downvalley, from 800 m to 1000 m a.s.l. the scric lobe was quite thin, and no terminal moraine system was preserved. again, the ela results are depressed to about 1190 m a.s.l., as in the mt. chiampon glacier as a whole. the ela for the internal moraine systems, which extended down to about 1150 m a.s.l., was calculated for the moeda and scric lobes and for pozzus and bombasine cirques (fig. 9a). the values are similar for the latter two, around 1375 m a.s.l., but slightly higher (1442 m) for the chiampon cirque. values for comparable moraine systems in vodizza valley and the central cirque of bombasine were discarded for the lack of welldefined frontal moraines. concerning the highest cirque moraines, located above 1300 m on the northern side of the two most elevated peaks, the chiampon and cuel di lanis (fig. 9b), the calculated elas are respectively of 1530 m and 1478 m a.s.l. 6. discussion 6.1 palaeomorphology of the venzonassa valley and the chiampon-cuel di lanis massif during the lgm the valleys of the eastern southern alps were invaded by widespread valley glaciers during the lgm. the front of these ice tongues formed a piedmont lobe in the case of the tagliamento glacier (monegato et al., fig. 8 reconstruction of the lgm palaeoglaciers; a) pozzus and the two lobes of the chiampon glacier (scric to the west and moeda to the east); b) bombasine; c) vodizza. contour line interval: 10 m, ela is marked in red line. local glaciers in the julian prealps (ne italy) during the last glacial maximum 11 2007) and the sava glacier (bavec & verbič, 2011), while the isonzo glacier was confined within the catchment (bavec et al., 2004). other minor catchments had only short glaciers or cirque glaciers (vai & cantelli, 2004), as was the case in the venzonassa and torre valleys. the location of the lateral moraines and periglacial deposits of the tagliamento glacier during the maximum advance indicates that the maximum elevation reached at the valley outlet was 500 m a.s.l. (monegato et al., 2007), while in the lowest reach of the valley, from venzone to gemona del friuli, the maximum elevation was of about 650 m a.s.l. (fig. 10). apparently, the ledis fork was not reached by the tagliamento glacier, as no glacial deposits occur there. the tagliamento glacier likely dammed the outlet of the venzonassa valley. no evidences of lacustrine sediments, related to an ice-dammed lake, have been recognized; however, the blockage of the outlet appears to have triggered alluvial sedimentation along the venzonassa valley, from the glacier front to the lowest reach. the venzonassa stream collected the meltwater from three different glaciers, flowing down the central portion of the chiamponcuel di lanis massif (fig. 10). these tongues reached elevations of 620 m (moeda lobe), 660 m (pozzus) and 490 m a.s.l. (bombasine). on the western side, the scric lobe, flowing down from the chiampon, is not represented by preserved frontal moraines. if it flowed down to 600 m a.s.l., it merged into the tagliamento glacier, but no traces of this junction have been recognized. possibly, it stopped at higher elevation, where the bedrock makes several steps, in which may have produced seracs. on the eastern side of the massif, the vodizza tongue flowed down along the northeastern side of the cuel di lanis and curved toward the east into the torre valley, abandoning a high lateral-frontal moraine at 630 m a.s.l. (figs. 5, 8). only the bombasine glacier, having a wider accumulation zone, reached an elevation below 600 m a.s.l., corresponding to the maximum elevation of the fluvioglacial deposits in the venzonassa valley. this relationship suggests that a rapid accumulation of fluvioglacial deposits took place during the advance of the tagliamento glacier, which dammed the venzonassa valley. the long-lasting residence of the tagliamento glacier in the lower reach of the valley, about 10 ka according to monegato et al. (2007), may have created an ice-dammed lake in the lower reach. at the same time, the high accumulation rate of coarse deposits in the western venzonassa valley prevented the establishment of a stable lake in its inner reaches. in the bombasine sector no fluvioglacial deposits are present. nevetheless, thick bedded diamicton, interpreted as waterlain till, is widespread in the lower reach of the deep valley. the terminal moraines of the studied paleoglaciers have smaller internal ridges, which suggest phases of oscillation of the glacier tongues before their retreat. at the collapse of the tagliamento glacier at about 18 ka, the equilibrium of the venzonassa stream changed and the incision of the present gorge took place. the withdrawal included some advancing pulses, represented by stadial frontal moraines located at about 1200 m and at 1400 m a.s.l.; however, chronological data to support an attribution to one of the alpine late glacial stadials (ivy-ochs et al., 2008; favilli et al., 2009) are lacking. for these stadial phases (namely late glacial 1 and 2, tab. 1) elas respectively of 1375-1442 m (fig. 9a) and 1478-1530 m a.s.l. (fig. 9b) were calculated. a more reliable chronological analysis of these late-glacial pulses may be possible once there is a more complete investigation of lateglacial systems in the carnian-julian alps, which have only attracted a few reconnaissance studies around the highest mountains (venturini, 2003), whereas it is outlined in the contiguous piave catchment (baratto et al., 2003; pellegrini et al., 2005). 6.2 the ela depression in the southeastern prealps palaeoclimatic analysis of the lgm has produced several models both for atmospheric circulation during the climate extremes in the alpine area (florineth & schluchter, 2000; kuhlemann et al., 2008; pini et al., 2010) and for palaeoenvironmental evolution of the fig. 9 reconstruction of the late glacial cirque glaciers: a) late glacial 1; b) late glacial 2. the ela is in dashed line. monegato g. 12 eastern southern alps (vai & cantelli, 2004; pini et al., 2010; monegato et al., 2011); though all these models invoke a southerly airflow from the mediterranean sea as moisture source. for the julian prealps, no estimates of the lia ela are available, though for the julian alps (mt. canin, 19 km to the northeast) a value of about 2190 m a.s.l. has been established. the difference between lgm and the present ela of the area has been estimated at about 1400 m (kuhlemann et al., 2008). hence, the values of the lgm-ela values below 1200 m, reported here, suggest a depression of about 1000 m below a possible lia analogue. it is noteworthy that the ela depression for gschnitz age moraines in this sector of the alps was evaluated at 900-1000 m (tintor, 2005), which in absolute elevation means that during the lgm, the ela of this sector of the alps was around 1000 m a.s.l. however, morphological factors should also be considered for this very low estimation, and perhaps ela values of the small glaciers of the prealps may not be extended to the major glaciers. further work is need for a better resolution of the ela in the inner sector of the julian alps. in the julian prealps accumulation areas occur below high and vertical northern cliffs; this fact induces snow mass movements (snowblow and avalanching) below the cliffs and at lower elevations. moreover, the high precipitation rate of the julian prealps, one of the highest in the alpine region (janža, in press), also points to fast ice accumulation and transport. this is in agreement with the high calculated balance ratio, which suggests a unsteady regime for these ice tongues, similar to those of wet areas like the west coast of north america (rea, 2009). considering the low elevation of the ablation areas, from 500 to 1000 m a.s.l., and the mean summer temperature (~8°) calculated for the lgm in the northeastern italy (pini et al., 2010), the glaciers of the julian prealps were probably very unstable, prone to surge movements and/or fluvioglacial outburst. the major glaciers may have been similarly affected, since the tagliamento glacier had one of the lowest ice-fronts of the alps, at 150 m a.s.l., consistent with a very depressed ela (kerschner & ivy-ochs, 2008) for the eastern southern alps during the lgm. 7. conclusions the julian prealps are a peculiar sector of the alpine chain, in which, in spite of their low maximum elevations, local glacial deposits are extensively preserved on northern slopes, down to till 500 m a.s.l. the northern side of the chiampon-cuel di lanis ridge (julian prealps) shows five different end moraine systems refig. 10 palaeogeographic sketch of the julian prealps during the lgm and the relationship between the glacier systems of the chiampon – cuel di lanis ridge (in white) and the major tagliamento glacier (blue). end moraines are represented in thick skyblue lines, outwash valley fill is in green, ela is marked in red line. name scric moeda pozzus bombasine vodizza catchment tagliamento venzonassa venzonassa venzonassa torre glacier lenght (m) 2000 3000 2400 3400 3400 elevation of the end moraine (m a.s.l.) unknown 600 690 490 620 maximum headwall elevation (m a.s.l.) 1709 1714 1679 1640 1628 surface of the accumulation area (km2) 1,076 0,950 2,891 1,019 surface of the ablation area (km2) 0,989 0,720 1,390 0,702 total 2,065 1,670 4,281 1,721 aar 0,52 0,57 0,68 0,59 aabr 1,18 1,74 4,33 2,11 ela lgm 1190 1145 1128 1182 ela late glacial 1 1450 1373 1377 ? ela late glacial 2 1530 1478 tab. 1 synthesis of the physical characters of the studied glacial systems and results of calculated ela and ratios. local glaciers in the julian prealps (ne italy) during the last glacial maximum 13 lated to local glaciers, up to 3.4 km long, which were independent from the major tagliamento glacier during the last glacial maximum (lgm). the elevations of the frontal moraines range from 490 m to 650 m a.s.l. clast petrography, of the predominantly limestone detrital assemblages, establishes a distinctly different provenance from that of the tagliamento glacial deposits. the tagliamento glacier did not flow into the venzonassa valley, so the local glaciers were free to spread with independent dynamics. geomorphological parameters, such as elevation of the valley floor and of the lateral moraines, the extent of the accumulation area and the contour belt areas crossing the glaciers, support estimates of ice thickness, ranging from 130 to 230 m in the accumulation areas. these parameters also yield the altitude x area balance-ratio (aabr) ela values ranging from 1130 m to 1200 m a.s.l., which are values in rough agreement with the ela depression modelled for the eastern southern alps below 1300 m a.s.l., but perhaps not ascribable to the major glaciers. these findings are consistent with the atmospheric circulation models of the lgm for the eastern alps, which indicate higher precipitation rates, controlled by southerly airflow, than the rest of the chain. acknowledgments the present work has the benefits of the cargfvg project coordinated by a. zanferrari. i am indebted with a. marchesini for dem images and with g. bryant for the english revision. i kindly thanks m. bavec and m. meneghel for their critical reviews and the editor a. sposato for his suggestions. references baratto a., ferrarese f., meneghel m., sauro u. (2003) la ricostruzione della glaciazione wurmiana nel gruppo del monte grappa (prealpi venete). in: biancotti a. & motta m. (eds.), risposta dei processi geomorfologici alle variazioni ambientali. brigati g., genova, italy, 67-77. bavec m., tulaczyk s.m., mahan s.a., stock g.m. (2004) late quaternary glaciation of the upper soča river region (southern julian alps, nw slovenia). sedimentary geology, 165, 165-183. bavec m., verbič t. (2011) glacial history of slovenia. development in quaternary science, 15, 385-392. benn d.i., ballantyne c.k. (2005) palaeoclimatic reconstruction from loch lomond readvance glaciers in the west drumochter hills scotland. journal of quaternary science, 20, 577-592. benn d.i., gemmell a.m.d. (1997) calculating equilibrium line altitudes of former glaciers by the balance ratio method: a new computer spreadsheet. glacial geology and geomorphology (http://ggg. qub.ac.uk/ggg/; but no longer available on-line). benn d.i., hulton n.r.j. (2010) an exceltm spreadsheet program for reconstructing the surface profile of former mountain glaciers and ice caps. computers & geosciences, 36, 605-610. benn d.i., lehmkuhl f. (2000) mass balance and equilibrium-line altitudes of glaciers in highmountain environments. quaternary international, 65/66, 15-29. bennet m., glasser n. (2009) glacial geology. wileyblackwell. carr s.j., coleman c.g. (2007) an improved technique for the reconstruction of former glacier mass-balance and dynamics. geomorphology, 92(1-2), 76-90. carr s.j., lukas s., mills s.c. (2010) glacier reconstruction and mass-balance modelling as a geomorphic and palaeoclimatic tool. earth surface process and landforms, 35, 1103-1115. carraro f., sauro u. (1979) il glacialismo “locale” wurmiano del massiccio del grappa (provincie di treviso e di vicenza). geografia fisica e dinamica quaternaria, 2(1), 6-16. castiglioni b. (1940) l’italia nell’età quaternaria. carta alla scala 1:200000. atlante fisico-economico d’italia, tci, milano. castiglioni g.b. (2004) quaternary glaciations in the eastern sector of the italian alps. in: elhers, j., gibbard, p.l. (eds.) quaternary glaciationsextent and chronology-part i: europe. elsevier, 209-215. desio a. (1926) l'evoluzione morfologica del bacino del fella. atti società italiana scienze naturali, 65, 205-461. ehlers j., gibbard p.l. (2004) quaternary glaciations– extent and chronology-part i: europe, elsevier, amsterdam, holland. favilli f., egii m., brandova d., ivy-ochs s., kubik p.w., maisch m., cherubini p., haeberli w. (2009) combination of numerical dating techniques using 10be in rock boulders and 14c of resilient soil organic matter for reconstructing the chronology of glacial and periglacial processes in a high alpine catchment during the late pleistocene and early holocene. radiocarbon, 51(2), 537-552. federici p.r., pappalardo m. (2010) glacier retreat in the maritime alps area. geografiska annaler, series a 92, 361-373. federici p.r., granger d.e., ribolini a., spagnolo m., pappalardo m., cyr a.j. (2012) last glacial maximum and the gschnitz stadial in the maritime alps according to 10 be cosmogenic dating. boreas, 41(2), 277-291, 10.1111/j.1502-3885.2011. 00233.x. feruglio e. (1925) carta geologica delle tre venezie. foglio 25 “udine”. ufficio idrografico regio magistrato acque di venezia. feruglio e. (1953) la regione carsica di villanova in friuli. pubblicazioni dell'istituto geologica dell'università di torino, 2, 1-68. florineth d., schlüchter c. (2000) alpine evidence for atmospheric circulation patterns in europe during the last glacial maximum. quaternary research, 54, 294-308. forno m.g., gianotti f., racca g. (2010) significato paleoclimatico dei rapporti tra il glacialismo principale e quello tributario nella bassa valle della dora baltea. il quaternario, 23(1), 105-124. fuchs s. (1970) studien zur karstun glazialmorphologie in der monte cavallo-gruppe / venezianische voralpen. frankfurter geogr., 47, 26-109. furbish d.j., andrews j.t. (1984) the use of hypsometry to indicate long-term stability and response of valley glaciers to changes in mass-transfer. jourmonegato g. 14 nal of glaciology, 30, 199-211. gortani m., desio a. (1927) note illustrative della carta geologica delle tre venezie. foglio “pontebba”. uff. idrogr. magistr. acque venezia, pp. 86. ivy-ochs s., kerschner h., reuther a., preusser f., heine k., maisch m., kubik p.w., schlüchter c. (2008) chronology of the last glacial cycle in the european alps. journal of quaternary science, 23, 559-573. janža m. (in press) impact assessment of projected climate change on the hydrological regime in the se alps, upper soča river basin, slovenia. natural hazards, doi: 10.1007/s11069-011-9892-7 kelly m.a., buoncristiani j.f., schlüchter c. (2004) a reconstruction of the last glacial maximum (lgm) ice-surface geometry in the western swiss alps and contiguous alpine regions in italy and france. eclogae geol. helv., 97, 57-75. kerschner h., ivy-ochs s. (2008) palaeoclimate from glaciers: examples from the eastern alps during the alpine lateglacial and early holocene. global and planetary change, 60, 58-71. kuhlemann j., milivojević m., krumrei i., kubik p.w. (2009) last glaciation of the šara range (balkan peninsula): increasing dryness from the lgm to the holocene. austrian journal of earth sciences, 102(1), 146-158. kuhlemann j., rohling e.j., krumrei i., kubik p., ivyochs s., kucera m. (2008) regional synthesis of mediterranean atmospheric circulation during the last glacial maximum. science, 321, 1338-1340. masini m. (1998) limite delle nevi perenni, oscillazioni frontali tardiglaciali e postglaciali e relazioni con il clima degli altopiani di fanes, sennes e fosses (dolomiti alpi meridionali). studi trentini di scienze naturali acta geologica 73, 107-117. monegato g., pini r., ravazzi c., reimer p., wick l. (2011) correlating alpine glaciation with adriatic sea-level changes through lake and alluvial stratigraphy. journal of quaternary science, 26(8), 791804. monegato g., ravazzi c., donegana m., pini r., calderoni g., wick l. (2007) evidence of a two-fold glacial advance during the last glacial maximum in the tagliamento end moraine system (eastern alps). quaternary research, 68(2), 284-302. ohmura a., kasser p., funk m. (1992) climate at the equilibrium line of glaciers. journal of glaciology, 38, 397-411. orombelli g., tanzi g., ravazzi c. (2004) glacier extent over the italian alps during the lgm. in: antonioli f. & vai g.b. (eds.) climex maps italy, explanatory notes. bologna, 23-24. osmaston h. (2005) estimates of glacier equilibriumline altitudes by the area x altitude, area x altitude balance ratio and the area x altitude balance index methods and their validation. quaternary international, 138-139, 22-31. pellegrini g.b., albanese d., bertoldi r., surian n. (2005) la deglaciazione alpina nel vallone bellunese, alpi meridionali orientali. geogr. fis. din. quat., suppl. vii, 271-280. penck a., brückner e. (1901-1909) die alpen im eiszeitalter. vol. 1-3, 1199 pp. tauchnitz, leipzig. pini r., ravazzi c., reimer p.j. (2010) the vegetation and climate history of the last glacial cycle in a new pollen record from fimon lake (southern alpine foreland, n-italy). quaternary science reviews, 29, 3115-3137. rea b.r. (2009) defining modern day area-altitude balance ratios (aabrs) and their use in glacierclimate reconstructions. quaternary science reviews, 28, 237-248. tintor w. (2005) zum spätglazial in den nördlichen tälern der italienischen julischen alpen. carinthia ii, (195/115), 497-514. vai g.b., cantelli l. (2004) litho-palaeoenvironmental maps of italy during the last two climatic extremes. l.a.c., firenze. van husen d. (1997) lgm and late-glacial fluctuations in the eastern alps. quaternary international, 38/39, 109-118. venturini c. (2003) il friuli nel quaternario: l’evoluzione del territorio. in: muscio g. (ed.), glacies. comune di udine museo friulano storia naturale, udine, 23-106. zanferrari a., monegato g., poli m.e., masetti d., (in press) note illustrative della carta geologica d’italia alla scala 1:50.000; foglio 049 “gemona del friuli”. ispra-servizio geologico d’italia regione autonoma friuli-venezia giulia. ms. received: january 16, 2012 final text received: february 16, 2012 microsoft word 01_negri_lm05.doc available online http:/amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 25 (2), 2012, 81-89 mediterranean sapropels: a mere geological problem or a resource for the study of a changing planet? alessandra negri1, florence colleoni2 & simona masina2,3 1 dipartimento di scienze della vita e dell’ambiente, università politecnica delle marche, ancona (italy) 2 centro euro-mediterraneo per i cambiamenti climatici, bologna (italy) 3 istituto nazionale di geofisica e di vulcanologia, bologna (italy) corresponding author: a. negri <a.negri@univpm.it> abstract: sapropels are sediments rich in organic carbon occurring cyclically in the mediterranean marine records and whose origin has been matter of great debate during the last decades. while the first sapropels were found in eastern mediterranean sediments from the miocene period, in this paper we focus on the layers that were subsequently found in sediment cores of pliocene to quaternary age from the eastern mediterranean mostly. since the very beginning of the history of studies on sapropels, authors inferred that those levels, being interbedded as dark layers in more or less normal light “open marine” sediments, formed during short-lived but catastrophic alterations in mediterranean oceanographic conditions, probably linked to broader climate changes. in this paper, the main hypotheses regarding the origin of those sediments are described and we highlight the importance of sapropel records for the study of climatic and oceanographic variability in the mediterranean area in the context of global climate change. keywords: mediterranean sea, plio-pleistocene, sapropel, paleoclimate. 1. introduction more than 477 papers have been published in the last 40 years with the keywords ‘mediterranean sapropels’. publication frequency is plotted in fig. 1. the number of papers published over this time interval is highly fluctuating, and this evidences periods of high interest and moments of decline in the attention to the topic. in this paper, we will recall the main approaches to the sapropel issue and we will propose new challenges in the study of these objects that must be seen not only as a local geological problem, but as a resource for the understanding of our changing planet. 2. the historical record the occurrence of stagnation episodes in the mediterranean basins during quaternary was first predicted by bradley (1938), who proposed that sapropels were due to low sea level in the glacial mediterranean. though, no marine sedimentary evidence was available at that time to strengthen his hypothesis. later on, kullenberg (1952) discussed the problem of sapropel formation as related to interstitial salinity variations using the cores of the swedish deep sea expedition (1948). few years later, olausson (1961) argued that sapropels were deposited after cold periods of glacially lowered sea level (about 100 meters lower than at present); during these periods, communication between the western and eastern mediterranean became restricted through the straits of sicily, resulting in an increase of salinity in the eastern basins, notwithstanding the (eventual) increase in runoff and precipitation. at the same time, surface water temperature decreased by about four degrees centigrade, increasing the density of surface water and leading to a continual renewal of the bottom water mass (e.g. non-sapropel condition). during deglaciation, temperature and sea level rose, then water density tended to decrease near the surface, as a result of less saline water added from the atlantic through the western mediterranean. as this transgression persisted, sea level eventually reached the elevation of the sill at the bosporus (40 m), causing low-density water from the black sea to pour out into the aegean, further lowering the density of surface water of the eastern mediterranean. then, the combination of warm, low-density superficial water led to density stratification and to stagnation of bottom water and sapropel formation. this model has been subsequently variously discussed by several authors (e.g chamley, 1971; miller, 1972; ryan, 1972; nesteroff, 1973; mccoy, 1974; cita et al., 1973). however, olausson's classic glacio-eustatic model was not sufficient to explain all aspects of sapropel formation. during dsdp legs 13 and 42a (ryan et al., 1973; hsu et al., 1978) in the mediterranean sea, many sapropels were obtained from deep sea cores and stimulated researchers to find explanations for their origin. sigl et al. (1978) suggested that differing faunal and lithological characteristics within sapropelic layers of different ages were indicative of different mechanisms of sapropel formation. since according to brongersma-sanders (1957) bituminous rocks may be formed when “either the supply of oxygen to the lower water layers is excessively low (persistent stagnation), or the supply of dead plankton and other oxidizable material is extremely high (hypertrophy)”, sigl et al.1978 proposed that both mechanisms could have helped to explain the occurrence of negri a. et al. 82 sapropelic sediments in “preglacial” lower pleistocene and upper pliocene sediments recovered by dsdp leg 13 (ryan et al., 1973; cita et al., 1973), as well as others in miocene cores recovered by leg 42a (hsu et al., 1978). during the same dsdp leg 42a, the discovery of sapropelic sediments in the western mediterranean (kidd et al., 1978) proved that this phenomenon was not entirely restricted to the eastern basin as it was assumed at that time, therefore stimulating new hypothesis about the mechanisms of sapropel formation. from that time on, two main models, encompassing the earlier hypotheses, were proposed to explain sapropel deposition: the “stagnation/anoxia” and the “increased productivity” models. according to the stagnation/anoxia model, anoxic bottom conditions are caused by a strong stratification of the water column that prevents vertical mixing and oxygen supply to the bottom waters. the origin of this stratification was explained as being due to increased nile river runoff linked to the periodic intensification of the african-asian monsoons (rossignol-strick 1983, 1985) and, later, by increased rainfalls and river discharge along the northern part of the eastern mediterranean sea (cramp et al., 1988; rohling & hilgen, 1991). in this framework, sarmiento et al. (1988) proposed a reversal in the water flow circulation as the most effective way of increasing nutrient concentrations to the point where anoxia occurs. indeed, numerical studies on thermohaline circulation suggest that a weakening of the present-day anti-estuarine circulation can lead to the deposition of enough organic carbon to account, at least, for the formation of the youngest sapropels s5 (125 ka) to s1 (9 ka) (myers et al., 2000; stratford et al., 2000). in addition, more recently, bianchi et al. (2006) suggested that a weak thermohaline circulation, supplying oxygen only to the first 500 meters of the water column can cause the development of an anoxic blanket at the seafloor, when coupled with increased productivity in the euphotic zone. in the “increased productivity” model, sapropel deposition was linked to enhanced organic matter flux (calvert, 1983; calvert et al., 1992), since the present production of organic matter in the eastern mediterranean cannot account for the high values of organic carbon (toc) characterizing these layers (calvert, 1983). this view has been further supported by evidence of a significant increase of productivity at times of sapropel deposition revealed by paleo-productivity proxies, as barium and marine barite concentration (e.g., thomson et al., 1995, 1999; martinez-ruiz et al., 2000, 2003; gallego-torres et al., 2007). later on, after the pioneer phase when the scientific community argued that the above mentioned processes were mutually exclusive, another phase followed when some authors (rohling & gieskes, 1989, castradori, 1993; rohling, 1994; emeis et al., 1996; emeis et al., 2000a) proposed a mechanism resulting from the combination of the two processes: stratification and productivity increase could have been caused by an overall increase of nutrient input via river runoff. however, uncertainties still exist regarding the vertical extension of the anoxic/dysoxic layer in the water column and this layer has been described either as a large water mass extending below the mixed layer (murat & got, 2000; stratford et al., 2000), or as an “anoxic blanket” above the sediment/water interface (casford et al., 2003). regarding the increase of productivity several hypothesis have been proposed, the most intriguing being that of kemp et al. (1999) who infer the formation of diatom mats during summer seasons of prolonged stratification (resulting from a water density contrast produced by nile run-off). the rapid sinking of the mats at the beginning of autumn–winter wind mixing, then, is assumed to produce a massive load of organic material to the sediments that consumed the available oxygen in the water column, creating anoxic conditions. from massbalance calculations, they argue that all of the organic carbon preserved in sapropels could have been supplied by diatoms. although the model can apply only to sapropels containing diatoms, the authors pointed out that the silica of these diatoms is highly soluble, and therefore that sapropels lacking diatoms may have once had them. on this basis, sancetta (1999) argued that the mechanism invoked for modern sapropels might therefore apply, as analogues, to other carbon-rich laminated strata, such as the 120-100 million year old mid-cretaceous black shales. a more refined hypothesis was proposed by meyers (2006) who suggested that increased continental run-off would have delivered abundant nutri fig. 1 papers published in the last 40 years having the word ‘sapropel’ in the title. mediterranean sapropels resource 83 ents that would have first stimulated algal productivity, magnified export of organic matter, and increased mid water oxygen demand. the combination of surface water dilution, which increased salinity stratification of the upper water column and thereby discouraged mixing and mid-water ventilation, and magnified oxygen-drawdown, would have intensified and expanded the oxygen minimum zone such that anoxia intruded into the photic zone. after photosynthetic cyanobacteria, green sulfur bacteria and chemosynthetic archaea became established, their primary productivity would have first augmented and then potentially would have superseded that of algae (e.g., kuypers et al., 2001; 2002 a,b). the shift to microbe-amplified productivity would have persisted until climate reverted to less wet conditions. sapropels occur all over the mediterranean area recorded after odp legs 160 and 161 (emeis et al., 1996; comas et al., 1996), which yielded the complete record of all the sapropels occurring in the last 5 million years, but they also outcrop on land sections (mainly in greece and italy). however, sprovieri et al. (2012), who investigated mechanisms of sapropel deposition in the mediterranean basin during the last 3.5 ma, showed that the water properties and circulation of both eastern and western mediterranean sea during the plio/pleistocene appear to be conditioned by the bathymetric control at the gibraltar and the sicilian sills. according to these authors, climatically driven intensity and characteristics of the western mediterranean deep water formation drive timings and modes of deposition of the organicrich layers in the alboran sea (odp sites 976 and 977). indeed, they claim that western sapropel deposition is generally not synchronous to precession minima, contrary to sapropel deposition in the eastern mediterrane fig. 2 from bottom to top: medstack detrended power in the 23k, 41k and 100k band (colleoni et al., 2012); sapropels (black, organic content > 2%) and grey layers succession from emeis et al. (2000) and lourens et al. (1996); total organic content (toc, %) of the black sapropels from the succession described above. the toc values are from odp 964, opd 966, odp 967 and odp 969. when different toc values were found in several cores for the same sapropel layer, the larger toc value was selected in order to better highlight the response of the mediterranean to the climate forcing. some of the black sapropels from lourens et al. (1996) does not have any toc value assigned because no analysis have been found. african monsoon index (in langley) based on rossignol-strick (1983). the vertical dotted line corresponds to the intensification of the northern hemisphere glaciation (~2.75 ma). negri a. et al. 84 an, and is largely related to the formation and vertical shift of oxygen minimum zones probably due to the rapid rise of the sicilian sill in the last 2 ma. therefore, sapropels occur cyclically, but not in phase, in the eastern and western basin. this hypothesis agrees with that proposed by rogerson et al. (2008) who demonstrated the older age (4-5 ky) of the most recent organic rich layers (orl) occurring in the western mediterranean, and hypothesized that it might be instead related more to the global sea level changes and resulted from a strong reduction in surface water density and shoaling of the interface between the intermediate and deep waters during the deglaciations. we can therefore see the deposition of eastern mediterranean sapropels in a framework of a reversed circulation. in fact, the present day circulation between the mediterranean sea and the atlantic ocean depend on the fact that evaporation exceeds precipitation. this way atlantic surface water, less saline and hence less dense, flows into the mediterranean. conversely, mediterranean salty waters flow at intermediate deep out of the basin. this type of circulation pattern is often referred to as anti-estuarine and is the opposite to the black sea circulation where fresh surface water flow out of the black sea to the mediterranean sea and salty mediterranean sea water flows through the bosphrous into the black sea. then, the black sea acts as a nutrient trap and is anoxic. in this view, trabucho-alexandre et al. (2012), argued that oceanic basins at the senile stadium of the wilson cycle (i.e. the cycle of opening and closing of an ocean basin due to plate tectonics) as presently the mediterranean is, can respond with black shales (sapropels) only if the circulation is estuarine, like in the black sea. then, the combination of sprovieri (2012) results and trabucho-alexandre (2012) hypothesis suggest that the eastern basin could be seen as a restricted basin due to the sicilian sill that hampers the flow of the levantine intermediate water and turns the eastern basin in a euxinic environment at the time of sapropel deposition. this somehow agrees with the hypothesis postulated by sarmiento et al. (1988), but overall, it suggests that, at least for the past 2 ma, western mediterranean orl and eastern mediterranean sapropels respond to different triggering mechanisms. this means that whatever is the mechanism triggering the sapropel deposition, those objects represent an important record to be studied in detail not only at regional scale, to understand which can be the relationship with the global ocean dynamic processes. 3. new clues only few attempts have been made to link what happened in the mediterranean region over the last 5 myr to coeval global climate change during that time period. sapropels or orl need not to be seen simply as regional geological problems. instead they are a precious source of information useful for understanding the evolution of our planet. in particular, the message contained within eastern mediterranean sapropels has to be interpreted in a global context: they are the consequence of extreme but episodic climate changes due to particular monsoonal and oceanic conditions that have favoured a very large production and deposition of organic carbon. the recent paper by colleoni et al. (2012) attempted to interpret the mediterranean oceanic changes as seen from the eastern mediterranean planktonic δ18o stack (hereafter medstack, lourens, 2004, wang et al., 2010) in a global context. the global and mediterranean climate changes over the last 5 ma are compared and linked through the spectral analysis of various marine records performed over the three orbital bands (100-kyr, 41-kyr related to obliquity and, 23+19-kyr related to precession). in the mediterranean planktonic signal, three periods were identified: until ~ 2.2 ma the signal is dominated by the 23+19-kyr frequency which is linked to the african monsoon influence in colleoni et al. (2012); from 2.2 ma to ~ 1.2 ma the signal is dominated by the 41-kyr frequency which is interpreted as the incursion of the polar influence into low latitudes; and finally, after the mid-pleistocene transition the signal is dominated by the 100-kyr frequency (fig. 6 in colleoni et al. 2012). how do the sapropels fit in the story? the pliopleistocene eastern mediterranean succession of organic-rich layers (emeis et al., 2000a, lourens et al. 1996, fig. 2) is based on odp sites 964, 966, 967 and 969 and on the capo rossello land section. this sapropel time-series is almost continuous and shows that, even if after 2.2 ma the medstack variability is driven by the 41-kyr frequency, the eastern mediterranean remains, however, paced by the african monsoon influence since the variance in the 23+19-kyr band remains strong all along the last 5 ma. nevertheless, some interruptions of the cyclical deposition of sapropels are observed and the longest one occurred during the socalled middle pleistocene revolution (mpt) at ~0.7 ma when the dominant frequency of the global climate variability changes from 41-kyr to 100-kyr. the interruptions are interpreted by colleoni et al, 2012 as an intrusion of the northern high-latitudes cooling signal into the low latitudes and therefore would have perturbed the periodic deposition of sapropels. in addition, in the first part of the pliocene, before the northern hemisphere glaciation (nhg) intensification, the occurrence of gray intervals (roughly: not well developed sapropels) suggests that the monsoon intensity was reduced during the early pliocene compared to the late pleistocene and that the monsoon was able to penetrate further into north in africa (larrasoana et al., 2003) only during strong precession minima. in the sapropel succession of fig. 2, we implemented the work of colleoni et al. (2012) which made a distinction between black sapropels, (organic carbon > 2% in weight following the convention of kidd et al., 1978) and grey layers showing a lower content of organic carbon. black sapropels seem to be quite scarce until ~3.4 ma, while after this time, grey layers (organic content < 2%) disappear almost completely (fig. 2). this suggests that marine productivity (or organic matter preservation) increased after 3.4 ma, this fact supported by the total carbon content (toc) values from the black sapropels succession described previously and reported in fig. 2. it shows that after 3.4 ma, the toc increased mediterranean sapropels resource 85 until reaching ~ 32% in weight during the intensification of nhg (~2.75 ma) and then gradually decreased until present-day. what caused such a toc increase ? as previously described, sapropels are assumed to form under particular oceanic temperature, salinity and productivity conditions, when a significant fresh water run-off reaches the mediterranean waters. whatever was the cause of sapropel deposition (either anoxia or productivity), based on that information, the issue is if we can directly relate the variations in toc to variations in continental run-off quantity and then to fluctuations in monsoon intensity alone. rossignol-strick (1983) tried to establish such a link by calculating an “african monsoon index” (fig. 2) for the last four glacial cycles based on the summer insolation anomaly between the equator and 23°n. they postulated that each sapropel layer corresponded to high monsoon index value (≥ 41 ly). to check whether this hypothesis was valid also for the oldest sapropels, we expanded their calculation for the entire plio-pleistocene period, and we point out if each large monsoon index value is associated with a grey layer or a black sapropel (fig. 2). nevertheless, each sapropel or grey layer does not always correspond to a high monsoon index value as calculated by rossignolstrick (1983). indeed, with this monsoon index, rossignol-strick (1983) assumed that a larger insolation input always triggered higher monsoon precipitation. but monsoon could be intense in terms of winds and/or precipitation. this implies that if sapropels were deposited under weak monsoon precipitation regimes, the mediterranean oceanic conditions (temperatures, salinity, oxygen) compensated somehow for the lower (but still higher than during “non sapropel” sedimentation) fresh water input. we can thus conclude that fluctuations in toc suggest that (i) either the monsoon precipitation started intensifying toward 3.4 ma and then weakened after ~2 ma, (ii) or that since 3.4 ma the sensitivity of the mediterranean waters (in terms of temperature, salinity and oxygen) to sudden warm climate fluctuations increased, and then decreased after 2 ma. this is consistent with the concomitant global climate cooling (lisiecki and raymo, 2005) which could have enhanced the sensitivity of the extra-tropical regions to brief and warm climate fluctuations. as a result, it is possible that this gradual global cooling increased the sensitivity of the mediterranean waters and of the monsoon system to large insolation peaks towards the nhg (~2.75 ma), allowing for particularly concentrated black sapropel deposition. in addition, khelifi et al. (2009) showed that the mediterra fig. 3 time series of the benthic stack lysieki and raymo (2005), co2 concentration in the vostock ice core (petit et al 2000) and occurrence of sapropels in the mediterranean sea. it is evident that the occurrence of sapropels corresponds to increases in co2 concentration. thickness of sapropel does not correspond to time duration. s1 and s5 are thicker to highlight the correspondence to the sharper co2 increase (circa 100 ppm) recorded after terminations ii and i, respectively. negri a. et al. 86 nean outflow intensified toward ~3.4 ma suggesting that changes in oceanic circulation occurred at this time. the relatively low value in toc during the pliocene could be due to the fact that the mean global climate state was warmer at this time and that consequently the monsoon intensity was almost constant and had only a limited impact on the stable mediterranean circulation. similarly, during the early pleistocene period, the mean global climate state evolved towards cooler temperatures. in that new climate context, all the system readjusted and despite the larger amplitude between glacial/interglacial periods that occurred at the end of the quaternary, the mediterranean became again less sensitive to the monsoon fluctuations as during the early pliocene period, or only during particularly warm interglacials (e.g. mis 11 and mis 5). 4. concluding remarks and perspectives there is still much to do in the study of sapropels. the relationship between toc, sapropels and the monsoon index of rossignol-strick (1983) is a further example that the mediterranean sea is adequate to study the high/low-latitude climate interplay, reflecting the dual response of the monsoon system to the mean global climate state and to regional climate constraints. the paper by colleoni et al. (2012) shows that after the intensification of the nhg (~2.75 ma), sapropel formation was influenced the waxing and waning of ice sheets in the northern high latitudes and therefore was sensitive to a north-south influence of climate, whereas the mediterranean dynamics were controlled by a east-west water mass exchange (discrepancies in the sapropels distribution between east and west). moreover, the medstack planktonic signal variability during the late pleistocene exhibits a sawtooth shape, as observed in many other records such as the benthic oceanic records or the speleothems timeseries, and is interpreted as a signature of the glacials/interglacials alternation. those observations raise several questions: (i) how can the global climate signal affect the mediterranean and how much does the flow exchange with the north atlantic at the gibraltar strait influence the mediterranean? (ii) what is the interplay between the monsoon signal and the mediterranean mean climate state? the need of exploring these questions also arises from other proxies that could be related to sapropel deposition such as, for example, the time-evolution of atmospheric co2 over the last 800 kyr. fig. 3 shows a detail of the last two glacial terminations (i and ii, 18-8 and 140-126 ka respectively) that correspond to abrupt increase of 100 ppm in the co2 atmospheric concentration in few thousands of years (vostok ice core, petit et al. 2000). at the end of the terminations, co2 reaches the maximum concentration, and simultaneously in the mediterranean sapropels s1 (9-6 ka) and s5 (midpoint age 124 ka) deposited. in addition, other minor interstadial fluctuations of atmospheric co2 are associated to sapropel deposition as well (fig. 3). is there a direct correlation between the large release of co2 in the atmosphere after a glaciation and the almost simultaneous production of organic carbon in the mediterranean? if yes, this could be seen as a local response of the systems to carbon removal from the oceanic water masses during the interglacial periods (co2 uptake in ocean increases during glacial periods). the large increase in atmospheric co2 is affecting the present-day world climate and there are few doubts that the temperature increase is related to this fact even if a direct correlation has not been demonstrated. understanding how the system reacts to co2 increase and, in the case of the mediterranean sea, tends to respond by taking up carbon that goes buried in marine sediments is an important issue that deserves an in-depth exploration by the scientific community. it is important to understand and investigate whether sapropels are part of a process that triggers co2 burial from global to regional scales and from millennial to decadal timescales. examples from the mesozoic era, when carbonate platforms were widespread, show that those platforms demise slightly preceded the deposition of black shales (cobianchi & picotti, 2001, chiari et al. 2007) evidencing a sort of balance in the carbon pump shifting from a carbonate system to a siliciclastic organic carbon-rich system in which the organic carbon content is due to primary producers that remove carbon either as organic carbon (corg) in the cells and also in the carbonate tests. in the mediterranean basin, carbonate platforms survived until the pliocene and the demise of some of them has been proven to occur, again, slightly before the deposition of sapropels (capozzi & picotti, 2003). numerical modeling of the biotic response under different atmospheric and oceanic scenarios can help to understand how quick the system responds, but so far only few models have been proposed (bianchi et al. 2006, meijer & tuenter, 2007) and their aim was restricted to analyze the phenomena at the regional scale, in order to explain the deposition of particular sapropels. instead, the exploration of the relationships among these sedimentary systems and the climate (primarily the monsoon influence) should be explored also at a global scale in order to understand the interplays between different regions in the world and the teleconnections between low and high latitudes. in conclusion, with this short review, we aim to stimulate the (paleo) climate community to expand the view of the mediterranean sapropels record as a product of the interplay of different global and regional processes and variability. the connections between all those processes have to be taken in consideration for understanding how the earth responds to climate changes at different timescales, to predict which changes can occur in a near future and how societies can adapt. acknowledgements the authors warmly thank j. trabucho-alexandre and n. ciaranfi for the careful revisions and important suggestions. we also acknowledge f. falcieri and a. sabbatini for useful comments on a early draft of the manuscript and alessio rovere for improving the english spelling. references bianchi d., zavatarelli m., pinardi n., capozzi r., capotondi l., corselli c., masina s. (2006) simulation of ecosystem response during the sapropel mediterranean sapropels resource 87 s1 deposition event. palaeogeography, palaeoclimatology, palaeoecology, 235, 265-287. bradley w. h. (1938) mediterranean sediments and pleistocene sea levels. science, 88, 376-379. brongersma-sanders m. (1957) mass mortality in the sea. in hedgpeth, p. w. (ed.), treatise on marine ecology and paleoecology, part 1: mem. geol. soc. am., 67, 941-1010. calvert s.e. (1983) geochemistry of pleistocene sapropel and associated sediments from the eastern mediterranean. oceanologica. acta, 6, 255-267. calvert s.e., nielsen b., fontugne m.r. (1992) evidence from nitrogen isotope ratios for enhanced productivity during formation of eastern mediterranean sapropels. nature, 359, 223225. capozzi r., picotti v. (2003) pliocene sequence stratigraphy, climatic trends and sapropel formation in the northern apennines (italy). palaeogeogr. palaeoclimat. palaeoecol., 190, 349-371. casford j.s.l., rohling e.j., abu-zied r.h., fontanier c., jorissen f.j., leng m.j., schmiedel g., thomson j. (2003) a dynamic concept for eastern mediterranean circulation and oxygenation during sapropel 400 formation. palaeogeogr., palaeoclimatol., palaeoecol., 190, 103-119. castradori d. (1993) calcareous nannofossils and the origin of eastern mediterranean sapropels. paleoceanograpy, 8, 459-471. chamley h. (1971) recherches sur la sedimentation argileuse en méditerranée. sciences géologiques strasbourg, mémoire, 35, 1-225. cita m.b., chierici m.a., ciampo g., moncharmont zei m., d'onofrio s., ryan w.b.f. and scaziello r. (1973) the quaternary record in the tyrrhenian and ionian basins of the mediterranean sea. in ryan, w. b. f., hsü, k. j., et al., initial reports of the deep sea drilling project, volume 13: washington (u. s. government printing office), 1263-1339. cita m.b., vergnaud-grazzini c., robert c., chamley h., ciaranfi n., d’ onofrio s. (1977) paleoclimatic record of a long deep sea core from the eastern mediterranean. quat. res., 8, 205-235. chiari m., cobianchi m., picotti v. (2007) integrated stratigraphy (radiolarians and calcareous nannofossils) ofthe middle to upper jurassic alpine radiolarites (lombardian basin, italy): constraints to their genetic interpretation. palaeogeography, palaeoclimatology, palaeoecology, 249, 233-270. cobianchi m., picotti v. (2001) sedimentary and biological response to sea-level and paleoceanographic changes of a lower-middle jurassic tethyan platform margin (southern alps, italy). palaeogeography, palaeoclimatology, palaeoecology, 169, 219244. colleoni f., masina s., negri a., marzocchi a. (2012) plio-pleistocene high-low latitude climate interplay: a mediterranean point of view. earth planet sc. lett., 319-320, 35-44. comas m.c., zahn r., and klaus a., et al. (1996) proc. odp, init. repts., 161: college station, tx (ocean drilling program). doi:10.2973/odp.proc.ir.161.1996. cramp a., collins m., west r. (1988) late pleistoceneholocene sedimentation in the nw aegean sea: a paleoclimatic-paleoceanographic reconstruction. palaeogeography, palaeoclimatology, palaeoecology, 68, 61-77. emeis k.-c., robertson a.h.f., richter c., et al. (1996) proc. odp, init. repts., 160: college station, tx (ocean drilling program). doi:10.2973/odp.proc.ir. 160.1996. emeis k.-c., sakamoto t., wehausen r., brumsack h.j. (2000a) the sapropel record of the eastern mediterranean sea-results of ocean drilling program leg 160. palaeogeogr. palaeoclimatol. palaeoecol., 158, 371-395. emeis k.-c., struck u., schulz h.-m. rosenberg r., bernasconi s., erlenkeuser h., sakamoto t., martinez-ruiz f. (2000b) temperature and salinity variations of mediterranean sea surface waters over the last 16,000 years from records of planktonic stable oxygen isotopes and alkenone unsaturation ratios. palaeogeogr. palaeoclimatol. palaeoecol., 158, 259-280. gallego-torres d., martinez-ruiz f., paytan a., jiménezespejo f.j., ortega-huertas m. (2007) plioceneholocene evolution of depositional conditions in the easternmediterranean: role of anoxia vs. productivity at time of sapropel deposition. palaeogeogr., palaeoclimatol., palaeoecol., 246, 424-439. hsu, k.j., montadert, l., garrison, r. e., fabricius, f.h., mueller, c., cita, m.b., bizon, g., wright, r.c., erickson, a.j., bernoulli, d., melieres, f., kidd, r.b. (eds) (1978)initial reports of the deep sea drilling project 42 part 1. texas a & m university, ocean drilling program, college station, tx, united states p. 1139-1140 issn: 0080-8334 kemp a.e.s., pearce r.b., koizumi i., pike j., rance s. j. (1999) the role of mat-forming diatoms in the formation of mediterranean sapropels. nature, 398, 57-61. khelifi n., sarnthein m., andersen n., blanz t., frank m., garbe-schoenberg d., haley b.a., stumpf r., weinelt m. (2009) a major and long-term pliocene intensification of the mediterranean outflow, 3.5-3.3 ma ago. geology, 37, 811-814. kidd r.b., cita m.b., ryan w.b.f. (1978) stratigraphy of eastern mediterranean sapropel sequences recovered during leg 42a and their paleoenvironmental significance. initial reports of the deepsea drilling project 42a, 421-443. lourens l. (2004) revised tuning of ocean drilling program site 964 and kc01b (mediterranean) and implications for the d18o, tephra, calcareous nannofossil, and geomagnetic reversal chronologies of the past 1.1 myr. paleoceanography, 19, pa3010. lourens l.j., antonarakou a., hilgen f.j., van hoof a.a.m., vergnaud-grazzini c., zachariasse w.j. (1996) evaluation of the plio-pleistocene astronomical timescale. paleoceanography, 11 (4), 391413. kullenberg b. (1952) on the salinity of the water contained in marine sediments. goteb. akad. vet.vittsomhales, handl. sjatte fol, 8(6), 3-37. kuypers m.m.m., blokker p., erbacher j., kinkel h., pancost r.d., schouten s., sinninghe damsté j.s. (2001) massive expansion of marine archaea during a mid-cretaceous oceanic anoxic event. science, 293, 92-94. kuypers m.m.m., pancost r.d., nijenhuis i.a., sinninghe damsté j. s. (2002a) enhanced productivity led negri a. et al. 88 to increased organic carbon burial in the euxinic north atlantic basin during the late cenomanian oceanic anoxic event. paleoceanography, 17, 1051, doi:10.1029/222pa000569. kuypers m.m.m., blokker p., hopmans e.c., kinkel h., pancost r.d., schouten s., sinninghe damsté j. s. (2002b) archaeal remains dominate marine organic matter from the early aptian oceanic anoxic event 1b. palaeogeography, palaeoclimatology, palaeoecology, 185, 211-234. larrasoaña j.c., roberts a.p., rohling e.j., winklhofer m., wehausen r. (2003) three million years of monsoon variability over the northern sahara. clim. dyn., 21, 689-698. lisiecki l.e., raymo m.e. (2005) a pliocene-pleistocene stack of 57 globally distributed benthic 18o records, paleoceanography, 20, pa1003, doi: 10. 1029/2004pa001071 martinez-ruiz f., kastner m., paytan a., ortega-huertas m., bernasconi s. m.(2000) geochemical evidence for enhanced productivity during s1 sapropel deposition in the eastern mediterranean. paleoceanography, 15, 200-209. martinez-ruiz f., paytan a., kastner m., gonzález-donoso j.m., linares d., bernasconi s.m., jimenezespejo f.j. (2003) a comparative study of the geochemical and mineralogical characteristics of the s1 sapropel in the western and eastern mediterranean. palaeogeography, palaeoclimatology, palaeoecology, 190, 23-37. mccoy f.w. (1974) late quaternary sedimentation in the eastern mediterranean sea: ph. d. thesis, harvard university, cambridge, massachusetts. meijer p.t., tuenter e. (2007) the effect of precession-induced changes in the mediterranean freshwater budget on circulation at shallow and intermediate depth. journal of marine system, doi: 10. 1016/j.jmarsys.2007.01.006. meyers p.a. (2006) paleoceanographic and paleoclimatic similarities between mediterranean sapropels and cretaceous black shales. palaeogeography, palaeoclimatology, palaeoecology, 235, 305320. miller a.r. (1972) speculations concerning bottom circulationin the mediterranean sea. in stanley, d.j. (ed.), the mediterranean sea. strasbourg, virginia (dowden, hutchison and ross), 37-42. murat a., got h. (2000) organic carbon variations of the eastern mediterranean holocene sapropel: a key for understanding formation processes. palaeogeogr. palaeoclimatol. palaeoecol. 158, 241257. myers p.g., haines k., rohling e.j. (2000) modelling the paleocirculation of themediterranean: the last glacial maximum and the holocene with emphasis on the formation of sapropel s1. paleoceanography, 13 (6), 586-606. nesteroff w.d. (1973) petrography and mineralogy ofsapropels. in ryan, w.b.f., hsü, k.j., et al., initial reports of the deep sea drilling project, 13, washington (u.s. government printing office), 713-720. olausson e. (1961) studies of deep-sea cores rep. swed. deep sea exped. 1947-1948, 8, 353-391. petit j.r., raynaud d., lorius c., jouzel j., delaygue g., barkov n. i., kotlyakov v. m. (2000) historical isotopic temperature record from the vostok ice core. in trends: a compendium of data on global change.carbon dioxide information analysis center, oak ridge national laboratory, u.s. department of energy, oak ridge, tenn., u.s.a. doi: 10. 3334/cdiac/cli.006. rogerson m., cacho i., jimenez-espejo f., reguera m. i., sierro f.j., martinez-ruiz f., frigola j., canals m. (2008) a dynamic explanation for the origin of the western mediterranean organic-rich layers. geochemistry, geophysics and geosystems, doi: 10.1029/2007gc001936. rohling e.j.(1994) review and new aspects concerning the formation of eastern mediterranean sapropels. mar. geol. 122, 1-28. rohling e.j., gieskes w.w.c. (1989) late quaternary changes in mediterranean intermediate water density and formation rate. paleoceanography 4, 531-545. rohling e.j., hilgen f.j.(1991) the eastern mediterranean climate at times of sapropel formation: a review. geol. mijnbouw, 70, 253-264. rossignol-strick m.(1983) african monsoon an immediate climate response to orbital insolation. nature, 304, 46-49. rossignol-strick m. (1985) mediterranean quaternary sapropels, an immediate response of the african monsoon to variations of insolation. palaeogeography palaeoclimatology palaeoecology, 49, 237263. ryan w.b.f. (1972) stratigraphy of late quaternary sediments in the eastern mediterranean. in: stanley d.j. (ed.), the mediterranean sea: a natural sedimentation laboratory. dowden, hutchinson and ross, stoudsburg, pa, 149-170. ryan w.b.f., hsu k.j. cita m.b., dumitrica p., lort j.m., maync w., nesteroff w.d., pautot g., stradner h., wezel, f.c., kaneps, a.g., (eds) (1973) initial reports of the deep sea drilling project 13, part 2. texas a & m university, ocean drilling program, college station, tx, united states p. 1405-1415 issn: 0080-8334 sancetta c. (1999) the mistery of the sapropels. nature, 398, 6722. sarmiento j.l., herbert t., toggweiler j.r. (1988) mediterranean 515 nutrient balance and episodes of anoxia. global biogeochem. cycles, 2, 427-444. sigl w., chamley h., fabricius f., giroud d’argoud g., müller j. (1978) sedimentology and environmental conditions of sapropels. initial reports of the deep-sea drilling project 42a, 445-465. sprovieri m., sannino g., sabatino n., sprovieri r., ribera d’alcalà m., artale v., mazzola s. (2012): sapropels and the achille‘s heels of the mediterranean. aiqua congress 2012 the transition from natural to anthropogenic dominated environmental change in italy and the surrounding region since the neolithic, pisa 15-17 february 2012. abstract book: 20. stratford k., williams r.g., meyers p.g. (2000) impact of the circulation on sapropelformation in the eastern mediterranean. global biogeochem. cycles, 14 (2), 683-530 695. thomson j., higgs n.c., wilson t.r.s., croudace i.w., de lange g.j., van sanvoort p.j.m. (1995) remediterranean sapropels resource 89 distribution and geochemical behaviour of redoxsensitive elements around s1, the most recent eastern mediterranean sapropel. geochimica et cosmochimica acta, 59 (17), 3487-3501. thomson j., mercone d., de lange g., van santvoort p.j.m. (1999) review of recent advances in the interpretation of eastern mediterranean sapropel s1 fromgeochemical evidences. marine geology, 153, 77-89. trabucho-alexandre j., hay w.w., de boer p. l. (2012) phanerozoic environments of black shale deposition and the wilson cycle. solid earth 3(1), 29-42. wang p., tian j., lourens l. 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documenti pdf creati possono essere aperti con acrobat e adobe reader 5.0 e versioni successive.) /enu (use these settings to create adobe pdf documents suitable for reliable viewing and printing of business documents. created pdf documents can be opened with acrobat and adobe reader 5.0 and later.) >> >> setdistillerparams << /hwresolution [1200 1200] /pagesize [396.850 566.929] >> setpagedevice amq29(1) 2 pini 19-34.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 29 (1), 2016, 19 34 ecological changes and human interaction in valcamonica, the rock art valley, since the last deglaciation roberta pini1, cesare ravazzi1, amelia aceti1, lorenzo castellano2, renata perego3, tommaso quirino4, francesca vallè5 1cnr idpa, research group vegetation, climate and human stratigraphy, lab. palynology and palaeoecology, milano, italy 2new york university, institute for the study of the ancient world, new york, usa 3integrative prehistory and archaeological science, university of basel, basel, swiss 4archaeological superintendence of lombardy, milano, italy 5university of milano-bicocca, dept. of environmental and earth sciences, milano, italy corresponding author: r. pini <roberta.pini@idpa.cnr.it> abstract: valcamonica is known all over the world for the development of rock art between the lateglacial and the middle ages. we present here an updated synthesis on the environmental history of valcamonica, focussing on the relationships between natural ecosystems, climate and human peopling. among the natural archives reviewed, a reference is the pian di gembro succession, a middle-altitude site offering a chronologically and taxonomically highly-resolved ecological investigation for the last 15.5 cal ka bp. for this site we present quantitative reconstructions of climate parameters obtained from fossil pollen spectra. the deglaciation of the valley floor occurred about 18-17.5 cal ka bp. remnants of a hut and rock engravings, referred to the upper paleolithic, are indication of human groups on the valley floor, possibly related to hunting activities on wild mammals sheltering in newlyestablished pine and larch forests. lowering of the timberline and expansion of xerophytic formations affected the montane and subalpine belts in the younger dryas. fast afforestation and timberline rise mark the holocene onset, as a result of abrupt climate improvement. a phase of hemisphaeric climate change, also recorded in ice cores at 8.2 cal ka bp, promoted the expansion of spruce and fir at middle altitudes. very high treeline altitudes (> 2,600 m asl) were withstood between 9.1-7.4 cal ka bp, as testified by finds of pinus cembra trunks and seeds of relevant age in high-altitude mires. in this span, high-altitude camps of mesolithic hunters, moving seasonally from the valley floor, left traces of forest fires, in the forms of charcoal fragments from hearths and pits with heat-fractured pebbles. archaeological and palaeoecological data suggest peopling discontinuity between 7.5 to ca. 6.5 cal ka bp, when farming started to develop. the oldest cereal pollen grain is detected at ca. 6 cal ka bp, consistently with the cultural chronology of early settlements in valcamonica. mountain pastoralism is documented only for later periods (bronze age onward) but detecting earliest traces high-altitude husbandry needs further research at subalpine areas preserving natural archives. alpine pastures and cereal fields further expanded since the early bronze age, despite a poor archaeological record for the period. during the first millennium bc rock art spread across valcamonica. iron age and roman time display high rates of forest exploitation, often related to iron-smelting activities, and agriculture expansion. chestnut and walnut appear between the i bc ii ad centuries. keywords: vegetation history, climate reconstruction, late glacial, holocene, human impact. 1. introduction the history of past landscapes and climate is a scientifically and socially relevant research topic. the recent ipcc fifth assessment report (ar5) resumes the state-of-the-art of the scientific knowledge on climate change and its effects on modern and past societies in terms of impact, adaptation, and mitigation (ipcc, 2014). holocene climate changes deeply affected the development of alpine civilisations, but, interestingly, knowledge on past climate regimes plays an important role also in the elaboration of future scenarios. prior to the onset of written sources and instrumental records, information on past landscapes and climate variables can be obtained from natural archives. thanks to the information retrieved from sediment cores drilled in basins located from the valley floor to the subalpine belt, the history of alpine valleys can be traced back to the last deglaciation. valcamonica, the cradle of the most important rock art culture of the alps (unesco, 1979), is one of the hotspots for disentangling the history of ecological relationships between human civilizations, mountain environment, and climate change. despite extensive work so far done surveying (ruggiero & poggiani keller, 2014) and interpreting (de marinis & fossati, 2012; ccsp, 2013) rock art, expression of the inhabitants of the valley from the middle neolithic to the middle ages, there are still many gaps in material culture and environmental frameworks. geographically, the rock art phenomenon covers the whole territory of the valley from lovere to ponte di legno, with more than 1,500 engraved rocks grouped in about 170 sites and shows a figurative language that varies from symbolic to more naturalistic and narrative elements. its chronology, however, is extremely difficult to be defined. on the one hand a relative chronology can be established based on the recognition of a stylistic 20 pini r. et al. evolution and on the superimposition of the figures; on the other hand, elements that allow anchoring this sequence to an absolute chronology are very few (e.g. figures of weapons with recognizable morphological features). furthermore, contexts in which archaeological levels stratigraphically investigated were found in connection with engraved rocks are rare. in any case, rock art is the evidence of the close relationship between the first human communities and the territory. though the knowledge of contemporary archaeological contexts is not detailed, in the last few years, thanks also to the opening of the mupre the national prehistory museum of valle camonica (poggiani keller, in press) increasing attention is given to the study of settlements, necropolis and cult places related to rock art sites. in this way, the development of rock art styles is seen as a reflection of the different phases of population of the valley and of the exploitation of its natural resources by humans. in fact, the engraving tradition persisted for a longer period during which the society expression of human groups inhabiting the valley has become increasingly complex. this complexity is also related to the economic aspects, namely subsistence economy and food production, as well as to climate and other natural triggers. for this reason, there is an increasing need for interaction between different disciplines, such as palaeoclimatology, archaeology, archaeozoology and palaeobotany. in this paper we provide a synthesis of the current knowledge on regional landscape, climate and human history of the oglio river catchment, i.e. the valcamonica and its tributary valleys (fig. 1 and 2). we will focus on stratigraphic archives accumulated within lakes and mires containing an organic fraction, made up by macroscopic and microscopic plant debris and remains of terrestrial and aquatic invertebrates. the detailed analysis of these remains (tens to hundreds of samples along a stratigraphic column), supported by 14c chronologies, provide data on past vegetation structure, land fig. 1 location of the valcamonica in the italian alps and of main reference geographic areas and towns mentioned in the text. a white line shows the oglio river catchment closed at the outlet of the iseo lake. the dark blue area marks the reconstructed extent of the iseo lake at the time of deglaciation, about 18-17.5 cal ka bp. 21 ecological history of valcamonica since the last deglaciation ... use changes, occurrence of human settlement and activities. the archives considered in this review are mostly in an “off-site” position, in the sense of edwards (1991). we use the term "off-site" for sites external to human settlements, not directly biased by processes leading to the formation of archaeological deposits. those are often affected by erosional hiatuses and/or display the rapid accumulation of debris connected to human activities, thus failing in recording the environmental history with stratigraphic continuity and appropriate resolution. by comparing several off-site records, the palaeoecological analysis may disentangle the impact of man and of climate. detail on each site can be found in tab. 1, their chronological extent is shown in fig. 4 (see hereinafter). in this perspective recent pollen-based mean annual temperature reconstructions of late glacial to holocene at one site (pian di gembro, site 7 in fig. 2 and fig. 3) are of help (fig. 5). this is the first quantitative palaeoclimate evidence for valcamonica, and is still open to further improvements. first we’ll introduce the palaeoclimatic framework as the prerequisite for evaluating the subsequent palaeoecological history. 2. quantitative reconstructions of past climate parameters from ecological archives the availability of huge amounts of data describing past environments, both in the terrestrial and aquatic realms (pollen, plant macrofossils, charcoal and wood logs, chironomids, freshwater algae, dinocysts, foraminifera, ostracoda and so on), raises the question of whether this information can be used for quantitative and not simply qualitative reconstructions. we concentrate here on pollen, its use as climate predictor is supported by some basic biological assumptions: if vegetation is a function of climate and pollen is a function of vegetation, then pollen is a suitable proxy for climate reconstructions. methodological and statistical guidelines (juggins & birks, 2012) can be profitably applied on already published palynological records for a direct comparison between vegetation and climate. the recent release of the empd (european modern pollen database: davis et al., 2013) allow the relationships between modern pollen and associated climate data to be modelled numerically to obtain transfer functions which convert fossil pollen data into quantitative estimates of past environmental variables (birks, 2003). in this paper we used one of the best late glacial holocene pollen record available in the alps, located at the watershed between valcamonica and valtellina, to obtain the first quantitative palaeoclimate estimation for this area. the record chosen is that from pian di gembro: this pollen record was published nearly 15 years ago (pini, 2002) but, at that time, the idea of using pollen spectra as climate proxy was not in discussion. 3. the palaeoclimate history. first palaeotemperature reconstruction for the last 15.5 cal ka bp based on the pian di gembro pollen record palynological records obtained from off-site stratigraphies provide the opportunity to develop continuous series of quantitative estimations of past temperature and precipitations. for the purpose of this paper we selected the pian di gembro pollen record as it is one of the highly-resolved (chronologically and taxonomically) palaeoecological studies so far carried out at alpine scale and, most important, it falls inside the geographical area considered for this review paper. the site complies to the off-site requirement, being several km far from known archaeological areas. the pian di gembro pollen record straddles a time interval of nearly 16 thoufig. 2 location of sites mentioned in the text. see tab. 1 for site numbers and information. tab. 1 altitude, geographical coordinates and main references of the palaeoecological and archaeological records used to reconstruct the ecological history of valcamonica. site numbers according to fig. 2. geographical coordinates according to the epsg 3857 web mercator projection, standard for web mapping applications. 22 pini r. et al. sand years, represented in 283 fossil spectra with a sampling interval of 60 years and a sound chronology relying on ten ams 14c dates from terrestrial plants and the recognition of biostratigraphic events at regional scale. pollen-based mean annual temperature reconstructions were obtained following the methodology described in pini et al. (2014) and presented by vallé et al. (2015). two solutions (i and ii, see fig. 5) are presented; they differ in the composition of the main pollen sum used for calculation of percentage values. in solution i gramineae are included in the pollen sum; in solution ii, based on the ratio between gramineae and artemisia between 8-15.3 cal ka bp, the signal due to local grasses was distinguished and % kept outside of the pollen sum. for both solutions, the empd database was explored with the lwwa technique and a transfer function generated and then applied to the fossil pian di gembro datasets for the climate reconstructions. mean annual temperature curves (°c) so far obtained are shown in fig. 5. these are the first direct estimation of a past climate parameter from the central alps, allowing comparison with other climate proxies (for example, the ngrip δ18o record). the reconstructed temperature series pinpoint events in agreement with the ngrip record of hemisphaeric variability (svensson et al., 2008) such as the temperature rise during the bøllingallerød interstadial and at the holocene onset, the younger dryas and preboreal coolings, the 8.2 cal ka bp event. secular events taking place in the last 3 thousand years, such as the early iron age cold phase, are detected in our temperature reconstructions and are chronologically consistent with known oscillations of large alpine glaciers (aletsch glacier, holzhauser et al., 2005; mer de glace, le roy et al., 2015; not shown in fig. 5). a more complete set of reconstructed past climate variables (monthly to seasonal temperature and precipitation) is needed for a detailed comparison with other climate proxies. actually, the first test performed at pian di gembro highlights the potential of fossil pollen spectra for quantitative estimations of temperatures and the need for regional and altitudinal analysis of the relationships between pollen rain modern vegetation climate parameters to improve reconstructions. 4. palaeoecological history of valcamonica. the landscape of the paleolithic hunters according to palaeoecology and radiocarbon dating from lake records, the final collapse of the oglio glacier took place around 18.5-17.5 cal ka bp (ravazzi et al., 2012). it can be argued that the entire valley floor and the largest alpine south-facing valleys were ice-free at the end of the gschnitz advance, 16-15.3 cal ka bp (ivy-ochs et al., 2006). the melting of last glacial maximum ice masses was followed by a millennia-long phase of slope instability and sediment readjustment, preventing a fast colonization by woody vegetation. paraglacial conditions and a mosaic of open conifer forests on stable surfaces persisted up to the onset of the bølling-allerød interstadial. evidence of fast afforestation at the interstadial onset in valcamonica were obtained from the following lakes and mire archives: pian di gembro (pini, 2002), passo del tonale and col di val bighera (sites 8 and 11 in fig. 2; gehrig, 1997) and loa peat bog (ravazzi et al., 2014a). some hundred years after the beginning of the bølling-allerød interstadial the treeline was located at ca. 1,700 m asl and conifer forests were rapidly thickening (fig. 5 and 7, the latter hereinafter). the occurrence of paleolithic human peopling along the valcamonica valley floor is suggested by quite a number of finds, hereafter briefly summarized. the find of an upper paleolithic hut at cividate camuno-via palazzo (site 15 in fig. 2; poggiani keller, 1999; baglioni & martini, 2009) represents the most significant evidence, still under study rock art figures engraved by an early “protocamuno” style at luine (site 17 in fig. 2; see also fig. 4) are given a possible final epigravettian age (martini et al., 2009). paleolithic finds are also dubitatively reported from the rockshelter 2 of foppe di nadro, at ceto (site 25 in fig. 2; zanettin, 1983). the occurrence of paleolithic groups in the valley floor can be related to the presence of wild mammals sheltering in conifer forests which were games for upper paleolithic hunters, their survival being dependent on the establishment of conifers (pinus mugo, pinus cembra and larix decidua), which occurred as early as 16,700 cal a bp in val borlezza (ravazzi et al., 2012), i.e. a lateral valley of middle valcamonica (fig. 1). however, precise age and subsistence facts for these paleolithic settlements cannot be traced so far, given the large uncertainty of the unique radiocarbon age so far availfig. 3 panoramic view of the pian di gembro peat bog, a key site for the reconstruction of regional climate and environments of the last 15 cal ka bp. 23 ecological history of valcamonica since the last deglaciation ... able for the hut (13,805±440 14c a bp, 2σ calibration interval 17.9-15.5 cal ka bp, median probability 16.7 cal ka bp) and the urgent need of revising its preliminary faunal assessment (fusco in poggiani, 1989). four of the figures engraved in the protocamuno style at luine were assigned to moose (alces alces) (anati, 1974), which occurrence is perfectly sound until the early holocene on the southern side of the alps (breda, 2002), but doubts have been recently cast over the interpretation of these cervid engravings (martini et al., 2009). indeed, in the lateglacial, the area of luine offered the preferred habitat for moose, as it was close to the shore of the large iseo palaeo-lake, extending north to cividate camuno at the time of deglaciation (fig. 1). the climate deterioration of the younger dryas (12.8-11.7 cal ka bp) led to a lowering of the forest limit down to ca. 1,500 m asl (ravazzi et al., 2007b) and a renewed expansion of xerophytic vegetation and grasslands affecting especially the montane and subalpine belts, while no data exist about the dynamics and peopling of the valley floor in this time span. 5. from the holocene first millennia to the atlantic period, across the 8.2 cal ka bp event, and the mesolithic a shift towards more negative isotopic δ18o values is recorded in polar ice cores at 11.7 cal ka bp, giving the onset to the present interglacial, i.e. the holocene. the climate amelioration, estimated in 4-6°c warming, led to a fast timberline rise in the alps (800 m in ca. 200-300 years, according to tinner & kaltenrieder, 2005), later reaching a position as high as 2,400-2,500 m in the inner alps (tinner, 2007). the continental climate regime that characterized the alps during the first millennia of the holocene abruptly ended at 8.2 cal ka bp, when moister conditions started to prevail (onset of the atlantic period). according to tinner & ammann (2001) this shift was possibly related to increasing humid air masses from west and northwest, resulting in reduced annual temperatures and increasing precipitations along the alpine chain. with the 8.2 cal ka bp event, picea abies (spruce) and abies alba (silver fir) expanded at middle altitudes in valcamonica, as shown in the pian di gembro pollen record (pini, 2002, fig. 6 and 7). even afterwards, the treeline remained high (> 2,600 m asl) as testified by the findings of fossil pinus cembra trunks in mires at 2,400 m asl at torbiera del lago nero near passo di gavia (site 12 in fig. 2; aceti, 2006) and of a pine wood at torbiera della costa (2,590 m asl, site 14 in fig. 2; ravazzi, unpublished data), dated to 7,775±65 14c a bp (2σ calibration interval 8.4-8.7 cal ka bp, median probability 8.55 cal ka bp). during the atlantic period, the montane landscapes of valtellina and valcamonica were dominated by dense picea abies and abies alba forests. these trees formed a wide altitudinal belt thriving both in oceanic conditions and in relatively more continental contexts. mixed broad-leaved forests dominated in the lower altitudes, up to 1,500 m asl. (fig. 6 and 7). the recent claim of mesolithic occupation at fig. 4 chronozones, archaeological periodization and chronological extent of the palaeoecological records available from valcamonica. for references on the chronostratigraphic subdivisions used in this scheme, see fig. 5. 24 pini r. et al. fig. 5 stratigraphic scheme summarizing the main events recorded in the vegetation, climate and cultural history of valcamonica since the last deglaciation. chronology and climate stratigraphic subdivisions are from orombelli & ravazzi (1996), ravazzi et al. (2007), svensson et al. (2008). duration of global lgm refer to clark et al. (2009); heinrich event i to stanford et al. (2011); ragogna oscillation to ravazzi et al. (2014b); längsee cold phase to schmidt et al. (2012); gschnitz stadial to ivy-ochs et al. (2006). rock art (1) from martini et al. (2009); rock art (2) from de marinis & fossati (2012). as for the pian di gembro data, solution i = gramineae included in the pollen sum used for % calculation; solution ii = local grasses excluded from the pollen sum (see also paragraph 11). below 14,300 cal a bp, curves are dotted because of uncertainties in the age depthmodel. light-blue bars indicate cold phases occurring during the last 12 cal ka bp and recorded both in the ngrip isotopic record and in the preliminary temperature records from the pian di gembro series. 25 ecological history of valcamonica since the last deglaciation ... cemmo, close to the valley floor (poggiani keller et al., 2014) deserves a specific archaeobotanical investigation. cemmo is not the only known site in the valley floor. the already mentioned site of cividate camunovia palazzo (poggiani keller, 1999, 2004) has been inhabited again during the early mesolithic (sauveterrian) and the rock shelter 2 of foppe di nadro (biagi, 1983) has been occupied during the late mesolithic (castelnovian). in early summer, groups of hunters used to move from the valley floor to high-altitude seasonal camps, such as those identified in malga rondeneto and laghi di ravènola (first mesolithic phase), and in val maione, dosso dell’asino, stanga di bassinale, sella di s. glisente and laghetti del crestoso (second mesolithic phase) along the ridge connecting valcamonica with valtrompia (biagi, 1997, biagi & starnini 2015). unlike other alpine valleys, mesolithic hunters used high-altitude sites in valcamonica even during the castelnovian. these mesolithic hunting activities, testified in the maniva massif, middle valcamonica, are accompanied by evidence of forest fires in the subalpine belt (baroni, 1997). a picea charcoal fragment from a hearth yielded an age of 7,870±50 14c a bp (2σ calibration interval 8.55-8.8 cal ka bp, median probability 8.7 cal ka bp). a very similar age was obtained on charcoals from a pit with heat-fractured pebbles (7,850±80 fig. 6 workroom to reconstruct the vegetation history of valcamonica during the last 18 cal ka bp. solution presented in fig. 5. 26 pini r. et al. 1997). the oldest cereal pollen identified at pian di gembro dates back to ca. 6 cal ka bp (see fig. 7). these data are consistent with the cultural chronology of early settlements from valcamonica. indeed, the first permanent settlements are referred to the middle and recent neolithic, and dated to the v-iv millennium bc (poggiani keller, 2010). the relevant settlements are: colle del lazzaretto at lovere (site 16 in fig. 2), coren pagà at rogno (site 27), luine at darfo-boario terme (site 17), cividate camuno-via palazzo (site 15) and breno-castello (site 19). they belong to square mouth pottery and lagozza cultures, but, as far as the recent neolithic is concerned, they also include typical and local elements attributed to a central alpine or “breno” cultural group. these settlements often show an uninterrupted occupation and testify to a significant demographic increase lasting until the end of the first millennium bc. megalithic sanctuaries and ceremonial centres were built in valcamonica during the copper age (mid iv-iii millennium bc) (poggiani keller, 2006); they are entitled by engraved stelae and menhir-boulders. the main sites are located on the plateau of ossimo-borno and at the localities of corni freschi at darfo-boario terme and cemmo at capo di ponte. menhir-boulders are also associated with a particular stylistic phase of rock art (i.e. the style iiia, casini, 1994; casini & fossati, 2013). together with solar and anthropomorphic figures, weapons and other symbols, there are both domestic and wild animals: cattle (yoked in ploughing scenes), swine, canids (dogs, wolves and foxes), cervids, goats (chamois and ibex) and other species, which made up the fauna of that time. the wide distribution of these sites in the territory confirm the settlement density recorded in the late neolithic. 7. the question of early mountain pastoralism the timberline depression observed at passo di gavia in the first half of the iv millennium bc raises the question of climate change versus early mountain pastoralism and human impact on upper forest belts. here we briefly summarize the status of the art in the alps and in valcamonica. according to barfield et al. (2003) the origins of mountain pastoralism can be framed in the iv millennium bc. the archaeological evidence underline the spread of mountain and high-altitude sites, while the exploitation of high-altitude pastures is just inferred (see marzatico, 2007), being clearly documented the agricultural practices in the mountain belt only, without evidence of herding over the timberline. indications for sedentary high-altitude herding in valle d’aosta, western alps (pini et al., 2013) come from a combined analysis of palynomorphs and nutrient history in a sedimentary succession from an alpine pond supposed to be used for animal husbandry (pini et al., in preparation). here, several 14c ages obtained on archaeological charcoal fragments retrieved from sites scattered in a radius of few hundred meters from the pond show a highly significant correlation with major vegetation 14c a bp, 2σ calibration interval 8.5-8.8 cal ka bp, median probability 8.67 cal ka bp). although not strictly related to the oglio river catchment, the mesolithic site of dosso gavia (angelucci et al., 1992) points to activities carried out by mesolithic hunters in the highlands of the gavia pass (site 12 in fig. 2). regardless to this mesolithic peopling, the high mountains were not settled while the neolithic farming in valcamonica started to develop in the subsequent millennia (biagi & starnini, 2015). the palaeoecological evidence presented in the following sections will also support this figure of highaltitude peopling discontinuity. 6. the middle holocene a pronounced expansion of fagus sylvatica (beech) started as early as 5.6-5.4 cal ka bp, synchronous to many other records in n-italy (magri et al., 2015, valsecchi et al., 2008). culturally, this forest change took place during the late neolithic, and continued in the early phases of the copper age. as observed at the sw -alpine border (e.g. brianza lakes; wick, 1996, gobet et al., 2000), beech expansion followed a phase of decreasing abundance of abies alba pollen in sediments. fagus expansion was possibly favoured by anthropic fires used by neolithic populations for forest clearing, drastically reducing the extent of abies alba stands (wick & möhl, 2006). other arguments, including synchronism at wide regional scale, support a concurrent climate trigger (valsecchi et al., 2008). phases of cooling and wet periods drove a timberline depression in all the alpine realm in the v millennium bc (tinner, 2007), which is, between the late neolithic and the onset of the copper age (pini et al., in preparation). consistently, at passo di gavia, the decline of swiss stone pine (pinus cembra) and the expansion of green alder (alnus viridis) scrublands are dated to 5.8-5.5 cal ka bp (aceti, 2006, see fig. 6 and 7). the palaeoclimatic context of oetzi also suggests glacier advance in the second half of the vi millennium bc (baroni & orombelli, 1996). the onset of early agriculture in valcamonica is not yet properly investigated nor framed in time. this is a major gap in the current understanding of the origin and development of one of the most representative civilizations of the alpine prehistory. the time span between 7.5-6.5 cal ka bp may be currently understood as a period of missing anthropic impact, both from cultural and palaeoecological evidence, spanning the period between the end of the mesolithic phase and the onset of farming. pollen of meadow plants, such as rumex acetosella type and ranunculus acris type, are registered continuously at pian di gembro from 6.8 cal ka bp. their interpretation is tricky, as they might be an indication of pastures some km far from the mire of pian di gembro or apophytes, i.e. native species taking advantage on disturbed land. this latter interpretation might be supported by the fact that the pollen of those species was present, also in the previous millennia, pointing out that they were already growing in the area. indicators of pastures (plantago lanceolata type and other herbs) and charcoal content increased ca. 6-5.8 cal ka bp (gehrig, 27 ecological history of valcamonica since the last deglaciation ... changes evidenced in the palynological record from the cored basin. the demise of conifer forests is here coupled with increasing abundance of pollen of pastures and coprophilous fungal spores (sordariaceae, sporormiella and podospora), and enhanced phosphorous input to the basin. furthermore, a doubtful molecular evidence for late neolithic cow transhumance has been recently reported for the western french alps (giguet-covex et al., 2013). on the other hand, in the eastern alps the palaeobotanical evidence is restricted to the copper/ bronze age transition (oeggl, 1994; festi et al., 2014) as observed at passo di gavia (aceti, 2006). the overall framework suggests that early pastoralism developed under the effects of concurrent climate and cultural changes. a cooling triggered forest depression, with coeval expansion of subalpine scrublands and alpine grasslands between 5.8 and 5.4 cal ka bp. in fig. 7 biosketch vegetation history valcamonica, 18.5 cal ka ago to modern time. the reconstruction is plotted against time and altitude, to show the time-development of vegetation belts. the spatial resolution of the reconstructed ecosystems depends on the availability of fossil records at relevant altitude (see fig. 4, 5, 6 and tab. 1). one of the well-known ploughing scenes from the bedoline area is here used to show the onset of agricultural practices in valcamonica, even though we are not sure whether the plough was already used around 6 cal ka bp. 28 pini r. et al. turn this is the favourable natural setting for the development of high-altitude herding, its effective establishment depending on local features such as accessibility, size of upland pastures, water supply and on human cultural history. further work is needed in valcamonica at high-altitude pastures preserving natural archives. 8. the onset of late holocene the bronze age around 4 cal ka bp fagus sylvatica was the dominant forest tree both at the prealpine margin and in the montane belt of outer alpine valleys. mixed stands of beech, spruce and silver fir were common in the central alps up to the first half of the subboreal period. however, in valcamonica beech did not reach the high forest cover values reconstructed in adjacent mountain regions (lake lavarone, eastern sector of the adige valley; filippi et al., 2005). with the onset of the early bronze age, pollen types typical of pastures (rumex acetosa and acetosella types, plantago lanceolata type) and ruderal areas (urtica and artemisia) slightly increase in the records so far studied (pian di gembro, dos del curù) testifying to a moderate expansion of grasslands and alpine pastures at mid and high altitudes respectively (fig. 5 to 7). such an expansion of ruderal land and pastures is only documented in the middle and high valcamonica, while no significant evidence emerges from the nearby val cavallina (gehrig, 1997; pini & ravazzi, 2009, see fig. 2). bronze age subalpine pastures affected the passo del gavia area (aceti, 2006) and the site of dos del curù in val saviore (site 9 in fig. 2; ravazzi et al., 2014a). nearby, the human presence is even attested at high-altitude areas by the discovery of bronze artefacts probably offered in votive deposits at lago d’arno (1,817 m asl; pigorini, 1911). in the nearby swiss alps cereal crop evidence at the montane and subalpine belt (between 1,200-1,800 m asl) is dated to the very beginning of the bronze age (ca. 2,200 bc) and appears to be correlated to terracing construction (zoller, 1998). on the whole, bronze age archaeological data from valcamonica are still fairly poor. pottery fragments coming from the long-lived settlements of luine at darfo -boario terme (anati, 1982), breno-castello (fedele, 1988) and dos dell’arca at capo di ponte (anati, 1968), recall the pile dwellings terramare culture of the po valley (de marinis, 1989). in valcamonica there are no archaeological evidences of pile dwellings or other kinds of bronze age dwellings and, as for the rock art, engravings of building structures do not clarify this topic. however, lake dwellings may have actually existed south of darfo-boario terme: they are expected to have been buried under the late holocene alluvial plain of the oglio river. this fascinating hypothesis was never explored so far to our knowledge. 9. the growth of farming in the iron age the iron age represents a main step of human demographic increase in the alpine realm and is marked by the spread of metal tools for agriculture and forest exploitation. the development of large protourban settlements and the need for wood for iron-smelting purposes promoted forest clearing and logging, especially in the valley floors, to obtain areas to be exploited for pastoralism. however, large sectors of the alps remained uninhabited. in valcamonica, the settlements of borno-val camera (site 30 in fig. 2), ossimo-pat (site 29) and berzo demo (site 28) and the house of temù-desert (site 31, together with other sporadic finds) join those already mentioned of darfo-boario terme, cividate camunomalegno, breno and capo di ponte, uninterruptedly persisted until this period. from a cultural perspective, a distinct and autonomous facies developed in this territory (including the neighbouring valtellina, valtrompia and valli giudicarie). it was characterized by linguistic and epigraphic homogeneity, specific funerary practices (attested in the necropolis of breno-val morina: bertolone et al., 1956-1957) and original elements of the material culture, but also open to external influences, especially from other central eastern alps cultures (de marinis, 1992, 1999; solano & simonotti, 2008; poggiani keller, 2009; solano, 2010). regardless to differential preservation of engravings due to variable weathering rate of rock surfaces in relation to rock properties, it seems that, during the first millennium bc, the rock art phenomenon spread throughout the valley. moreover, with the transition to the iron age and the development of aristocratic societies a change in the rock art language also appeared; no longer schematic and symbolic but more naturalistic and narrative: armed figures and warriors, therefore, took the place of those praying and of anthropomorphic figures. palaeoecological records from middle and high valcamonica point to the spread of pastoral activities, as seen at the cemmo sanctuary (poggiani keller et al., 2005), and suggested by increasing extent of pastures, meadows and larix decidua (larch) pollen at pian di gembro (pini, 2002). stable subalpine pastures developed also in the high alpine belt, e.g. passo del gavia. from the vii century bc cereal pollen is regularly found in the pian di gembro record, suggesting stable human settlements and cereal fields at a few km distance. 10. from the late iron age to the roman times and the middle ages the area of cividate camuno yielded vestiges of an iron age castelliere, a fortified borough testifying to a small pre-roman settlement, and a roman domus. civitas camunnorum was actually founded by the romans in the last decades of the i century bc, following the rules of the ager centuriatus system, with a theatre, an amphitheatre and thermal baths (mariotti, 2004). at cividate camuno construction works and renovation of buildings in the historical city center allowed sampling an archaeological stratigraphy. palaeobotanical evidence from via ponte vecchio 10 (site 1 in fig. 2) depicts the plant landscape of the valcamonica valley floor between the late iron age and the roman period (pini & ravazzi, 2010). broad-leaved deciduous forests with oaks, hazel, lime and elm fringed the slopes. sinan 29 ecological history of valcamonica since the last deglaciation ... thropic vegetation with cereal fields (avena-triticum type) and nitrophilous agro-pastoral habitats were widespread on flat areas and possibly on low-gradient slopes. ruderal plant communities of urban setting can also be inferred from pollen spectra. sediments from the analyzed profile yielded a high amount of cichorioideae pollen, along with a general poor degree of palynomorphs preservation. how can these features be interpreted? despite recent papers claiming the interpretation of cichorioideae as proxy of secondary pastures and primary open habitats in the mediterranean area (florenzano et al., 2015 and references therein), this explanation does not seem to be satisfactory when applied to northern italian sites and archaeological stratigraphies. studies on modern pollen rain along different habitats on an alpine altitudinal transect (cnr-idpa, unpublished data) are helpful in defining the cichorioidae as non-indicator taxon, that is a single/group of species with no degree of association between parent plants and pollen. the overwhelming content of cichorioideae pollen recorded at cividate camuno (mean percentage values of 400%, and up to 800% in some pollen spectra) just suggests that these herbs were common in the vegetation. the huge representation of this pollen type, very often recorded in archaeological sites developed in an urban context on dry terrains, when combined with a poorly-preserved palynoflora, speaks for issues related to pollen taphonomy and preservation, rather than a true correspondence with a real vegetation. selective degradation of pollen grains (and, on the other hand, the selective preservation of the strongest ones) is indeed a process known for oxidized sediments supporting intense bacterial activity (dimbleby, 1985). in 16 bc the valcamonica was subdued and soon became part of the roman system (for an overview: rossi, 2007). iron-smelting activities developed further along the prealpine margin of lombardy. wood resources were intensively used, leading to the disruption of native conifer forests close to mines. larix parkland expanded, as a result of stock breeding practices, in more open forests. increasing charcoal abundance in sediments points to rising anthropic pressure in the lowland and higher up. cereal cultivations took place in lowland areas from the ii century ad. cultivated trees mainly used for human consumption such as juglans regia (walnut) and castanea sativa (chestnut) were introduced in the valleys of lombardy between the i century bc and the ii century ad (drescher-schneider, 1994; gobet, 2000; pini, 2002; ravazzi et al., 2007a). this is confirmed also by the finding of walnut (juglans regia) remains in the site of pescarzo dated to ii-i century bc (castiglioni et al., 1999). older occurrence of walnut fragments in the ritual site of spinera at breno, dated to v-iii century bc have been interpreted as a likely long-distance transport, not a local cultivation of this tree (castiglioni & rottoli, 2010). indeed, walnut pollen record dated back to viii century bc in the central po plain with marked etruscan influence (ravazzi et al., 2013). in the middle ages, intense logging for ironsmelting activities (marziani & citterio, 1999) strongly reduced the range of abies alba in valcamonica and nearby valleys. open areas were then used for agropastoral activities. 11. contemporary dynamics the link from the past to the future in contemporary times (xix-xx century), intensive coppicing, logging and clearing in the middle valcamonica (pini, 2002; pini & ravazzi, 2009) favoured the replacement by spruce over fir and beech, thus forming a large mountain belt. cultivation of traditional crops developed, with buckwheat (fagopyrum esculentum), rye (secale cereale), corn (zea mays), barley (hordeum vulgare), olive (olea europea), potatoes (solanum tuberosum) and grapes (vitis vinifera). in recent years, experiments for the re-introduction of dyeing plants such as isatis tinctoria, rubia tinctoria, reseda lutea and matricaria chamomilla are going on at cividate camuno, thanks to the collaboration of the università della montagna in edolo. acknowledgements we dedicate this work to prof. carlo andreis, professor of plant geography at the university of milano, on the occasion of his retirement. c. andreis and prof. b. ammann (bern) promoted the palaeobotanical study of the pian di gembro peat bog, which forms a main reference for the vegetation history of valcamonica. the second author is grateful to dr. r. poggiani keller for inviting him to work on environmental history and archaeobotany in valcamonica. thanks are also due to prof. r.c. de marinis for sharing ideas on the relationships between men and landscape, to dr. m.g. ruggiero for providing drafts of the mupre short guide, to dr. f. simonotti, and to dr. s. solano for bibliographic suggestions. we also thank prof. b. sala and dr. m. breda for providing their opinion on the cervid engravings from luine. we are also indebted to ccsp (centro camuno studi preistorici, capo di ponte) for inviting us promoting researches and scientific exchange in one of the world-renowned rock art area. the authors acknowledge with thanks the advices by two reviewers. this paper is a contribution to the cnr research line ta.p02.005.001. part of this work was carried out in the framework of the cnr-dta nextdata project. references aceti a. (2006) la variabilità climatica nell'olocene: studio di torbiere e di ambienti di alta quota nelle alpi italiane. phd thesis, università degli studi di milano bicocca, pp. 150. anati e. (1968) origini della civiltà camuna. studi camuni, iii, capo di ponte, pp. 76. anati e. (1974) lo stile sub-naturalistico camuno e l’origine dell’arte rupestre alpina. bollettino centro camuno studi preistorici, 11, 59-83. anati e. (1982) luine collina sacra. archivi 8, capo di ponte, pp. 235. angelucci d., cremaschi m., negrino f., pelfini m. (1992) il sito mesolitico di dosso gavia val di gavia (sondrio, italia): evoluzione ambientale e popolamento umano durante l'olocene antico 30 pini r. et al. nelle alpi centrali. preistoria alpina, 28, 19-32. baglioni l., martini f. (2009) un contesto coevo. la capanna del paleolitico superiore di cividate camuno via palazzo. in: poggiani keller r. (ed.), la valle delle incisioni. 1909-2009 cento anni di scoperte, 1979-2009 trenta anni con l’unesco in valle camonica. catalogo della mostra, brescia, 21 marzo 10 maggio 2009, brescia, 197-202. barfield l., bernabò brea m., maggi r., pedrotti a. (2003) processi di cambiamento culturale nel neolitico dell’italia settentrionale. in: bernabò brea m., bietti sestieri a. m., cardarelli a., cocchi genik d., grifoni cremonesi r., pacciarelli m., (eds.), le comunità della preistoria italiana. studi e ricerche sul neolitico e le età dei metalli, atti della xxxv riunione scientifica, castello di lipari, chiesa di s. caterina 2-7 giugno 2000. istituto italiano di preistoria e protostoria, firenze, vol. ii, 665-685. baroni c. (1997) the stratigraphic sequences and the archeological structures. in: baroni c., biagi p. (eds), excavations at the high altitude mesolithic site of laghetti del crestoso (bovegno, brescia northern italy). ateneo di brescia, accademia scienze, lettere ed arti di brescia, 15-17. baroni c., orombelli g. (1996) the alpine iceman and holocene climate change. quaternary research, 46, 78-83. bertolone m., bonafini g., rittatore f. (1956-1957) tombe protostoriche di breno. la necropoli preromana di breno in valcamonica. sibrium, iii, 73-78. biagi p. (1983) segnalazione di industria mesolitica a trapezi dal riparo 2 di foppe di nadro in valcamonica. bollettino del centro camuno di studi preistorici, 20, 117-119. biagi p. (1997) ricerche sul mesolitico della valcamonica (brescia). bollettino del centro camuno di studi preistorici, 30, 23-40. biagi p., starnini e. (2015) human settlement and environmental exploitation of valcamonicavaltrompia watershed from the beginning of the holocene to the middle ages. natura bresciana, ann. mus. civ. sc. nat. brescia, 39, 195-209. birks h.j.b. (2003) quantitative palaeoenvironmental reconstructions from holocene biological data. in: mackay a., battarbee r.w., birks h.j.b., oldfield f., (eds.), global change in the holocene. arnold, london, 107-123 breda m. (2002) pleistocene fossil alcini (cervidae, mammalia) from lombardy and emilia romagna (north italy). mem. sci. geol. padova, 54, 51-63. casini s., ed. (1994) le pietre degli dei. menhir e stele dell’età del rame in valcamonica e valtellina. catalogo della mostra (bergamo, civico museo archeologico). centro culturale niccolò rezzara, pp. 224. casini s., fossati a.e. (2013) immagini di dei, guerrieri e donne. stele, massi incisi e arte rupestre dell’età del rame in valcamonica e valtellina. in: de marinis r.c. (ed.), l’età del rame. la pianura padana e le alpi al tempo di ötzi, 161-196. castiglioni e., cottini m., rottoli m. (1999) indagini archeobotaniche. in: rossi f. (ed.), la casa camuna di pescarzo di capo di ponte. sara santoro bianchi (a cura di) studio e conservazione degli insediamenti minori romani in area alpina. atti dell’incontro di studi, forgaria del friuli, 20 settembre 1997, pp. 166-170. castiglioni e., rottoli m. (2010) resti botanici dall’area sacra (vii secolo a.c. i secolo d.c.). in: rossi f. (ed.), il santuario di minerva. un luogo di culto a breno tra protostoria ed età romana, edizioni et, milano, pp. 118-123. ccsp (2013) xxv valcamonica symposium. art as a source of history. centro camuno di studi preistorici, capo di ponte. pp. 470. clark p.u., dyke a.s., shakun j.d., carlson a.e., clark j., wohlfarth b., mitrovica x., hostetler s.w., mccabe a.m. (2009) the last glacial maximum. science, 325 (5941), 710-714. davis b. and other 80 authors (2013) the european modern pollen database (empd) project. vegetation history and archaeobotany, 22, 521-530. de marinis r.c. (1989) preistoria e protostoria della valcamonica, valtrompia e valsabbia. aspetti della cultura materiale dal neolitico all’età del ferro. in: poggiani keller r. (ed.), valtellina e mondo alpino nella preistoria, catalogo della mostra, milano 1989, modena, 101-119. de marinis r.c. (1992) il territorio prealpino e alpino tra i laghi di como e di garda dal bronzo recente alla fine dell’età del ferro. in: metzger i.r., gleirscher p. (eds.), die räter/i reti, bolzano, 145-174. de marinis r.c. (1999) la cultura breno-dos dell’arca e il problema degli euganei. in: poggiani keller r. (ed.), atti del ii convegno archeologico provinciale, grosio 1995. quaderni del parco delle incisioni rupestri di grosio, 3, sondrio, 117-125. de marinis r.c., fossati a. (2012) a che punto è lo studio dell’arte rupestre della valcamonica. in: atti della xlii riunione scientifica dell’istituto italiano di preistoria e protostoria, l’arte preistorica in italia. trento, riva del garda, val camonica, 9-13 ottobre 2007. preistoria alpina, 46 ii, 17-43. dimbleby g.w. (1985) the palynology of archeological sites. london, academic press, pp. 176. drescher-schneider r. (1994) forest, forest clearance and open land during the time of the roman empire in northern italy (the botanical record). in: frenzel b. (ed.), evaluation of land surfaces cleared from forests in the mediterranean region during the time of the roman empire. esf project european paleoclimate and man, 5, 45-58. edwards k. (1991) using space in cultural palynology: the value of the off-site pollen record. in: harris h.d., thomas k.d. (eds.), modelling ecological change. institute of archaeology, university of london, 61-72. fedele f. (1988) l’uomo, le alpi, la valcamonica. 20 000 anni al castello di breno. la cittadina, boario terme, pp. 267. ferrari a., pessina a., visentini p. (2003) il coren pagà di rogno (alto sebino, bergamo). in ferrari a., visentini p. (eds.), il declino del mondo neolitico. ricerche in italia centro-settentrionale fra aspetti peninsulari, occidentali e nord-alpini. atti conve 31 ecological history of valcamonica since the last deglaciation ... gno, pordenone 5-7 aprile 2001, quaderni del museo archeologico del friuli occidentale, pordenone, 335-347. festi d., putzer a., oeggl k. (2014) mid and late holocene land-use changes in the ötztal alps, territory of the neolithic iceman "ötzi". quaternary international, 353, 17-33. filippi m.l., heiri o., arpenti e., angeli n., bortolotti m., lotter a.f., van der borg k. (2005) evoluzione paleoambientale dal tardoglaciale a oggi ricostruita attraverso lo studio dei sedimenti del lago di lavarone (altopiano di folgaria e lavarone, trentino). studi trentini di scienze naturali, acta geologica, 82, 279-298. florenzano a., marignani m., rosati l., fascetti s., mercuri a.m. (2015) are cichorieae an indicator of open habitats and pastoralism in current and past vegetation studies? plant biosystems, 149(1), 154-165. fusco v. (1989) i resti faunistici. in (poggiani keller p.) cividate camuno (bs). via palazzo. resti di insediamento paleo-mesolitico e neolitico. notiziario soprintendenza archeologica della lombardia 1988-89, 27-30. gehrig r. (1997) pollenanalytische untersuchungen zur vegetations und klimageschichte des val camonica (norditalien). dissertationes botanicae, 276. j. cramer, berlin stuttgart, pp. 152. giguet-covex c., pansu j., arnaud f., rey p.-j., griggo c., gielly l., domaizon i., coissac e., david f., choler p., poulenard j., taberlet p. (2013) long livestock farming history and human landscape shaping revealed by lake sediment dna. nature communications, 5, article number 3211. gobet e., tinner w., hubschmid p., jansen i., wehrli m., ammann b., wick l. (2000) influence of human impact and bedrock differences on the vegetational history of the insubrian southern alps. vegetation history and archaeobotany, 9, 175187. holzhauser h., magny m., zumbühl h.j. (2005) glacier and lake-level variations in west-central europe over the last 3500 years. the holocene, 15(6), 789-801. ingravallo e. (1984) scavi archeologici a seradina, notiziario ccsp, i, n. 4, capo di ponte, 21-22. ipcc, 2014, climate change 2014: impacts, adaptation, and vulnerability. part a: global and sectoral aspects. contribution of working group ii to the fifth assessment report of the intergovernmental panel on climate change. in: field c.b., barros v.r., dokken d.j., mach k.j., mastrandrea m.d., bilir t.e., chatterjee m., ebi k.l., estrada y.o., genova r.c., girma b., kissel e.s., levy a.n., maccracken s., mastrandrea p.r., white l.l., (eds.), cambridge university press, cambridge, united kingdom and new york, ny, usa, pp. 1132. ivy-ochs s., kerschner h., kubik p.w., schlüchter c. (2006) glacier response in the european alps to heinrich event 1 cooling: the gschnitz stadial. journal of quaternary science, 21(2), 115-130. juggins s., birks h.j.b. (2012) quantitative environmental reconstructions from biological data. in: birks h.j.b. et al. (eds.), tracking environmental change using lake sediments. data handling and numerical techniques, chapter 14, springer, 431494. le roy m., nicolussi k., deline p., astrade l., edouard j.-l., miramont c., arnaud f. (2015) calendardated glacier variations in the western european alps during the neoglacial: the mer de glace record, mont blanc massif. quaternary science reviews, 108, 1-22. magri d., emiliano a., di rita f., furlanetto g., pini r., ravazzi c., spada f. (2015) geographical trends in the holocene distribution of tree taxa in italy. review of palaeobotany and palynology, 218, 267 -284. mariotti v. (2004) il teatro e l'anfiteatro di cividate camuno. scavo, restauro e allestimento di un parco archeologico, firenze, pp. 408. martini f., baglioni l., poggiani keller r. (2009) le incisioni rupestri “protocamune” di darfo-boario terme: revisione e ipotesi di una cronologia paleolitica della figura zoomorfa sulla roccia n. 34 di luine. preistoria alpina, 44, 245-258. marzatico f. (2007) le frequentazioni dell'ambiente montano nel territorio atesino fra l'età del bronzo e del ferro: alcune considerazioni sulla pastorizia transumante e "l'economia di malga". preistoria alpina, 42, 163-182. marziani g., citterio s. (1999) the effects of human impacts on the arboreal vegetation near ancient iron smelting sites in val gabbia, northern italy. vegetation history and archaeobotany, 8, 225229. oeggl k. (1994) the palynological record of human impact on highland zone ecosystems. in: biagi p., nandris j. (eds.), highland zone exploitation in southern europe. natura bresciana, 20, 107-122. orombelli g., ravazzi c. (1996) the late glacial and early holocene: chronology and paleoclimate. il quaternario italian journal of quaternary sciences, vol. 9 (2), 439-444. pigorini l. (1911) oggetti di bronzo del bresciano. bullettino di paletnologia italiana, 36, 64. pini r. (2002) a high-resolution late glacial holocene pollen diagram from pian di gembro (central alps, northern italy). vegetation history and archaeobotany, 11(4), 251-262. pini r., castellano l., badino f., champvillair e., de amicis m., furlanetto g., maggi v., ravazzi c. (2014) from fossil pollen to climate: preliminary quantitative climate reconstructions for the last 3 ky in northern italy. conference "climate variability in italy during the last two millennia italy 2k", roma, 1-2 dicembre 2014. abstracts volume, 1516. pini r., guerreschi a., raiteri l., ravazzi c. (2013) preistoria degli ambienti d'alta quota in valle d’aosta. primi risultati di indagini paleobotaniche e archeologiche sull'altopiano del monte fallère. bulletin d’etudes prehistoriques et archéologiques alpines, vol. xxiii-xxiv (2012-2013), 1-9. pini r., ravazzi c. (2009) boschi, colture e pascoli 32 pini r. et al. nella media valtellina durante gli ultimi 7mila anni. notiziario archeologico valtellinese, vol. 7, 73-81. pini r., ravazzi c. (2010) cividate camuno (bs), via ponte vecchio 10. analisi pollinica della successione archeologica (tarda età del ferro età romana) ed interpretazione paleoambientale, relazione scientifica, rapporto interno cnr-idpa del 27 maggio 2010, pp. 66. pini r., ravazzi c., chiesa s., deaddis m. (2013) evoluzione paleoambientale del sito archeologico di pian delle greppe (cemmo, val camonica). parte iv. il carotaggio 2010: analisi polliniche e datazione 14c. ricostruzione dell'evoluzione stratigrafica e paleoambientale. rapporto scientifico c.n.r. conclusivo del luglio 2013, pp. 43. poggiani keller r. (1999) dinamica dell'insediamento nell'età del ferro in valtellina (italia). appendice i: resti insediativi del paleolitico superiore e del mesolitico nel centro urbano di cividate camuno in valcamonica (brescia-italia). in: della casa p. (ed.), prehistoric alpine environment, society and economy, int. coll. paese '97, zurich, universitätforschungen zur prähistorischen archäologie 55, 109-125. poggiani keller r. (2000) lovere (bergamo): una sequenza stratigrafica esemplare dal neolitico antico al bronzo finale in area prealpina. rivista di scienze preistoriche, l (1999-2000), 261-295. poggiani keller r. (2004) un passato di 13.000 anni. cenni sul popolamento pre-protostorico. in: mariotti v. (ed.), il teatro e l'anfiteatro di cividate camuno. scavo, restauro e allestimento di un parco archeologico, firenze, 5-10. poggiani keller r. (2006) santuari megalitici nelle valli lombarde. in: preistoria dell’italia settentrionale. studi in ricordo di bernardino bagolini. atti del convegno, udine settembre 2005, 243-266. poggiani keller r. (2009) un passato millenario. l’abitato dell’età del ferro di temù (valle camonica). in: bressan e. (ed.), la magnifica comunità di dalegno. dalle origini al xviii secolo, breno, 7-76. poggiani keller r. (2010) la valcamonica tra preistoria e protostoria. in: marretta a., cittadini t. (eds.), i parchi con arte rupestre della valcamonica guida ai percorsi di visita. centro camuno studi preistorici, 30-33. poggiani keller r., ed. (in press) mupre museo nazionale della preistoria della valle camonica. guida breve, pp. 159. poggiani keller r., lo vetro d., magri f., martini f., timpanelli l. (2014) mesolithic findings from the area of the engraved boulders at cemmo (lombardia). in: fontana et al. (eds.), mesolife a mesolithic perspective on alpine and neighbouring territories, abstract book. poggiani keller r., ruggiero m.g., chiesa s., deaddis m., pini r., ravazzi c. (2005) parco archeologico nazionale dei massi di cemmo. in: i parchi d’arte rupestre di capo di ponte, guida ai percorsi di visita. tipografia camuna, breno. ravazzi c., aceti a., donegana m., pini r., tanzi g., zanni m. (2007a) il quadro ambientale del territorio bergamasco negli ultimi 130 mila anni: vegetazione, clima e uomo. storia economica e sociale di bergamo, i primi millenni dalla preistoria al medioevo, i, 237-247. ravazzi c., badino f., marsetti d., patera g., reimer p.j. (2012) glacial to paraglacial history and forest recovery in the oglio glacier system (italian alps) between 26 and 15 kyr cal bp. quaternary science reviews, 58, 146-161. ravazzi c., badino f., donegana m. (2014a) poggio la croce-pian della regina (media valcamonica): inquadramento geomorfologico e storia paleoambientale. in: marretta a., solano s. (eds.), pagine di pietra scrittura e immagini a berzo demo fra età del ferro e romanizzazione, quaderni del parco nazionale delle incisioni rupestri capo di ponte, 4, 225-230. ravazzi c., marchetti m., zanon m., perego r., quirino t., deaddis m., de amicis m., margaritora d. (2013) lake evolution and landscape history in the lower mincio river valley, unravelling drainage changes in the central po plain (n-italy) since the bronze age. quaternary international 288, 195205. ravazzi c., peresani m., pini r., vescovi e. (2007b) il tardoglaciale nelle alpi italiane e in pianura padana. evoluzione stratigrafica, storia della vegetazione e popolamento antropico. il quaternario italian journal of quaternary sciences, 20(2), 163-184. ravazzi c., pini r., badino f., de amicis m., londeix l., reimer p.j. (2014b) the latest lgm culmination of the garda glacier (italian alps) and the onset of glacial termination. age of glacial collapse and vegetation chronosequence. quaternary science reviews, 105, 26-47. rossi f. (1999) la casa camuna di pescarzo di capo di ponte. in (santoro bianchi s., ed.) studio e conservazione degli insediamenti minori romani in area alpina. incontro di studi, forgaria del friuli, 20 settembre 1997, bologna, 143-150. rossi f. (2002) una casa camuna del i secolo d.c. spazi e oggetti di vita quotidiana, milano. rossi f. (2007) valle camonica romana. nuove ricerche in museo. quaderni del museo archeologico nazionale civitas cammunorum, milano. ruggiero m.g., poggiani keller r. (2014) il progetto “monitoraggio e buone pratiche di tutela del patrimonio del sito unesco n. 94 arte rupestre della valle camonica”, legge 20 febbraio 2006, n. 77, e.f. 2010, quaderni del parco nazionale delle incisioni rupestri capo di ponte, 5, pp. 344. scaife r. (1997) pollen analysis of the laghetti del crestoso corrie basin. in: baroni c., biagi p. (eds), excavations at the high altitude mesolithic site of laghetti del crestoso (bovegno, brescia northern italy). ateneo di brescia, accademia scienze, lettere ed arti di brescia, 64-76. schmidt r., weckstrom k., lauterbach s., tessadri r., huber k. (2012) north atlantic climate impact on early late-glacial climate oscillations in the south eastern alps inferred from a multi-proxy lake sediment record. journal of quaternary science, 27, 40-50. solano s. (2008) l’area archeologica di capo di ponte 33 ecological history of valcamonica since the last deglaciation ... (brescia), loc. le sante: ustrinum o brandopferplatz?. notizie archeologiche bergomensi, 16, 169 -213. solano s. (2010) il luogo di culto di spinera nella protostoria della valcamonica e dell’arco alpino centro-orientale. in: rossi f. (ed.), il santuario di minerva. un luogo di culto a breno tra protostoria ed età romana, milano, 127-131. solano s., simonotti f. (2008) berzo demo. un abitato alpino fra età del ferro e romanizzazione, esine, pp. 95. stanford j.d., rohling e.j., bacon s., roberts a.p., grousset f.e., bolshawa m. (2011) a new concept for the paleoceanographic evolution of heinrich event 1 in the north atlantic. quaternary science reviews, 30, 1047-1066. svensson, a., andersen k.k., bigler m., clausen h.b., dahl-jensen d., davies s.m., johnsen s.j., muscheler r., parrenin f., rasmussen s.o., röthlisberger r., seierstad i., steffensen j.p., vinther b.m. (2008) a 60.000 year greenland stratigraphic ice core chronology. climate of the past, vol. 4, 47-57. tinner w. (2007) treeline studies. encyclopedia of quaternary science, elsevier, 2374-2384. tinner w., ammann b. (2001) timberline paleoecology in the alps. in: kull c., reasoner m., alverson k. (eds.), pages news, 9(3), 9-11. tinner w., kaltenrieder p. (2005) rapid response of high-mountain vegetation to early holocene environmental changes in the swiss alps. journal of ecology, 93, 936-947. unesco (1979) convention concerning the protection of the world natural and cultural heritage. report of the rapporteur on the third session of the world heritage committee. cc-79/conf.003/13, cairo and luxor 22-26 october 1979, pp. 25. vallé f., pini r., castellano l., brunetti m., de amicis m., furlanetto g., maggi v., ravazzi c. (2015) pollen-inferred temperature series for the northern italian holocene. pages euromed 2k conference "climate variability and human impacts in central and eastern europe during the last two millennia". abstract book, 69. valsecchi v., finsinger w., tinner w., ammann b. (2008) testing the influence of climate, human impact and fire on the holocene population expansion of fagus sylvatica in the southern prealps (italy). the holocene, 18(4), 603-614. wick l. (1996) late glacial and early holocene palaeoenvironments in brianza, n-italy. il quaternario, italian journal of quaternary sciences, 9(2), 653-660. wick l., möhl a. (2006) the mid-holocene extinction of silver fir (abies alba) in the southern alps: a consequence of forest fires? paleobotanical records and forest simulations. vegetation history and archaeobotany, 15, 435-444. zanettin a. (1983) scavi al riparo 2 di foppe di nadro. bollettino del centro camuno di studi preistorici, 20, 112-117. zoller h. (1998) phases agricoles et établissement de terrasses de culture à l’âge du bronze. in: hochuli s.; niffeler u., rychner v. 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can be opened with acrobat and adobe reader 5.0 and later.) >> /namespace [ (adobe) (common) (1.0) ] /othernamespaces [ << /asreaderspreads false /cropimagestoframes true /errorcontrol /warnandcontinue /flattenerignorespreadoverrides false /includeguidesgrids false /includenonprinting false /includeslug false /namespace [ (adobe) (indesign) (4.0) ] /omitplacedbitmaps false /omitplacedeps false /omitplacedpdf false /simulateoverprint /legacy >> << /addbleedmarks false /addcolorbars false /addcropmarks false /addpageinfo false /addregmarks false /convertcolors /converttocmyk /destinationprofilename () /destinationprofileselector /documentcmyk /downsample16bitimages true /flattenerpreset << /presetselector /mediumresolution >> /formelements false /generatestructure false /includebookmarks false /includehyperlinks false /includeinteractive false /includelayers false /includeprofiles false /multimediahandling /useobjectsettings /namespace [ (adobe) (creativesuite) (2.0) ] /pdfxoutputintentprofileselector /documentcmyk /preserveediting true /untaggedcmykhandling /leaveuntagged /untaggedrgbhandling /usedocumentprofile /usedocumentbleed false >> ] >> setdistillerparams << /hwresolution [2400 2400] /pagesize [612.000 792.000] >> setpagedevice microsoft word 00_indice_bm03 available online http:/amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 25 (1), 2012, 15-23 sea level change in western-central mediterranean since 300 kyr: comparing global sea level curves with observed data fabrizio antonioli enea utmea, casaccia, roma, italy corresponding author: <fabrizio.antonioli@enea.it> abstract: in this study, we used published sea level markers to provide a review of observational data for the western-central mediterranean during the last 300 kyr. for the last interglacial (mis 5.5, 125 kyr bp) and holocene (10 kyr cal bp) periods, hundreds of data have been observed, measured, and dated using 14c, u/th, amino acid racemization (aar), and electron spin resonance (esr) methods. the maximum highstand for a mis 5.5 sea level is normally set at 7±2 m. this altitude remains a key value for the mediterranean sea and is often used to establish the neotectonic stability of coastal areas or to uplift/downlift rates in a tectonically active coast. information on mis 9 is available only from cores or terraces in tectonically active coastal areas. knowledge on mis 7 was recently improved by papers reporting precise sea level data from submerged speleothems in a stable coastal area: the argentarola cave (tyrrhenian sea, italy). these data (highstand duration and sea level) agree with global eustatic sea level curves. on the contrary, few observed data are available for mis 3, 5.1, and 5.3. moreover, most of these data disagree with global sea level curves. only one recorded and dated observational datum for mis 2 was published for the late glacial maximum (lgm) lowstand (-129.5 m in sicily). this datum agrees with global sea level curves and predicted sea level data from glacio-hydro-isostatic models. with regard to the holocene period, it can be assumed that sea level changes along the mediterranean coasts are the sum of eustatic, glacio-hydro-isostatic, and tectonic factors. the first is only time dependent, while the latter two also vary with location, which means that at the same time slices the sea level (the sum of three different movements) may be different in different coastlines. keywords: western-central mediterranean, global sea level change curves, observational data, last 300 kyr. 1. introduction this paper tries to use state-of-the-art methods in determining the observational points well connected to sea levels, comparing them with global sea level curves. this review constitutes a starting point for improving the observational data required for the projection of future coast scenarios. in some periods, such as mis 9 and 3, no observed data are available in stable coastal areas: for completeness of information, data are reported also in tectonically active areas, corrected with tectonic rates. the largest uncertainty in future sea level rise stems from our lack of a clear understanding of the dynamic response of ice sheets to anthropogenic climate change. the paleo records of sea level changes are potential resources to better constrain estimated future sea level rise (ipcc, 2007). sea level (hereafter, sl) variations during the last 300 kyr were caused by solar insolation (fig. 1) and ice melting, and they vary between +7 and -135 m in stable coastal areas in the western-central mediterranean sea (waelbroek et al., 2002). global sl curves are generally constrained by analyzing the δ18o ratio in the fossil foraminifera series, sampled on either the shelf edge or the ocean floor. changes in the δ18o ratio show a direct correlation with sl variations, allowing a quantitative estimate of sl changes. these curves do not take into account any isostatic or tectonic component. the global sl curves reported by waelbroek et al. (2002) (fig. 2) and siddal et al. (2003) were used in the present study. these authors show that robust regressions can be established between the relative sea level data and the oxygen isotope ratios of benthic foraminifera from the north atlantic ocean and the equatorial pacific ocean over the last climatic interglacial cycle. sea level predictions for the last 20 kyr using isostatic models are accepted worldwide. these models are often tested with observational data in tectonically stable areas. the isostatic contribution for mis 5 has been the subject of recent publications (potter & lambeck, 2004, for mis 5.3 and 5.1 and lambeck et al., in press, for mis 5.5), but for the mediterranean sea, the geophysical data are still lacking. completing these data will be the main challenge in sea level studies in the next years. 2. data mis 9 waelbroek et al. (2002) and siddal et al. (2003) indicated that during mis 9.1, the sl stand was at -17 and -38 m, respectively (table 1). no observational data are reported for stable coastal areas of the westerncentral mediterranean sea during mis 9. with regard to tectonically active coasts (either subsiding or uplifting), in a core drilled in the fondi plain (antonioli et al., 1988, a slightly subsided coastal area, tyrrhenian sea, central italy), sediments containing marine fossils found at 32 m were dated using amino acid racemization (aar) at aminozone g (mis 9). in the core “venezia 1,” kent et al. (2002) indicated the presence of marine sediments antonioli f. 16 during mis 9 at about -200 m. this area indicates a negative downlift of about -0.6 mm/year for the last 125 kyr and a mean of 0.36 mm/year for the last 700 kyr. in southern calabria, italy, miauyci et al. (1994) correlated mis 9 with terrace viii at about +300 m and indicated a mean of about +1 mm/tear for the last 125 kyr, in agreement with the data of westaway (1993). mis 7 for mis 7.1, 7.3, and 7.5, waelbroek et al. (2002) indicated that the sl was located at -10, -4, and -9 m, respectively, below the present sea level. in siddal et al. (2003), on the other hand, the sl is at -5, -29, and -3 m, respectively (table 1). in italy, a mis 7 record was found and dated in a submerged cave. the cave is located in a coastal area (in the argentarola island, central italy) that can be considered tectonically stable (bard et al., 2002). some speleothem samples from the cave are peculiar because they recorded several continental marine transitions. during lowstands, when the cave was emerged, dense sections of speleothem calcite were formed. during highstands, on the other hand, the argentarola cave was flooded and stalagmites were covered by colonies of the marine worm serpula massiliensis. in the same cave, bard et al. (2002) and dutton et al. (2009) determined that the sea level elevation peaked at -18 m during the mis 7.3 highstand and was between -18.5 and -21.0 m during the mis 7.2 lowstand. in contrast, the peak sea levels during mis 7.5 and 7.1 were above the highest reference point in the cave (-18 m). the observed lower peak sea level during mis 7.3 relative to mis 7.5 and 7.1 agrees with sea level reconstructions of global sl curves that are based on seawater δ18o determinations and with the flowstone dwbah sampled in submerged cave in bahamas (richards et al., 1994). underwater investigations along italian coasts (antonioli & ferranti, 1994; rovere et al., 2011) have shown a recurrent paleo-sea level from -15 to -20 m. geomorphological evidence of this sea level remains at subhorizontal abrasion surfaces, which are visible on a cliff bordering some carbonate promontories. antonioli & ferranti (1994) related the submerged terraces to mis 3, but i agree with rovere et al. (2011) that these submerged terraces could be related to mis 7 or, alternatively, to lower mis 5 stages. tectonically active coastal areas: using aar methods, de santis et al. (2010) found and dated mis 7 marine sediments at -32 m in a core in a slowly downlifting area in the apulia coast. on the other hand, using fig. 1 summer insolation at 65°n, from berger 1978. global sea-level curve from imbrie et al., 1984. fig. 2 global sea level curve from waelbroek et al. (2002) with observational data in stable areas quoted in this paper (green ballon) and argentarola marine (blue) continental brown) layers. sea level change in western-central mediterranean since 300 kyr… 17 tims u/th, antonioli et al. (2009) found and dated a mis 7.1 (197 kyr bp) sample of cladocora caespitosa at -72 m in the enea core in versilia, central italy. in southern calabria, miauyci et al. (1994) correlated a terrace located at about +250 m to mis 7. mis 6-5.5 few observational records show a very rapid oscillation of sl, named termination ii, at about 135 kyr bp, which cannot be explained by the milankovitch theory in its simplest form. after tectonic corrections, data show that sl reached -18 m around 135.8 kyr bp on the barbados coral reefs (gallup et al., 2002) considered slowly uplifting. at huon peninsula (papua new guinea), esat et al. (1999) dated some corals from the “aladdin’s cave” evaluating a sl of -14 m at 135 kyr bp and a drop in sl of 80\60 at 130 kyr bp after tectonic corrections. no in situ observational data have been found in the mediterranean sea, but capozzi & negri (2009), and references therein, observed termination ii in an isotopic study of planktonic and benthic foraminifera. mis 5 mis 5.5 the last interglacial (lig) shoreline coincides with mis 5.5, which occurred between 132 and 116 kyr bp (stirling et al., 1998; shackleton et al., 2003). the global sl curves (waelbroek et al., 2002; siddal et al., 2003) indicated sl at +7 and +17 m, respectively (table 1). a statistical approach on a worldwide compilation of data was published by kopp et al. (2009), who determined the posterior probability distribution of lig sl and ice volume through time, concluding that the highglobal sea level curve mis age metres age ka observed sea level mis / age metres 1 lambeck et al., 2011 predicted s.l for trieste 8 ka cal bp -11.2 m 1 lambeck et al., 2011predicted s.l for nora 8 ka cal bp -18.7 m lambeck et al, 2011 2 predicted s.l for termini imerese (sicily, italy) 20 ka cal bp -127 m waelbroek et al., 2002 2 -123 20 caruso et al., 2011, observed on termini imerese continental shelf 21.8 ka cal bp -129.5 m siddal et al 2003 2 -115 19.5 waelbroek et al., 2002 3.1 -62 39.5 carboni et al., 2010, amorosi et al 2004, 3.1 not present at -60 m siddal et al 2003 3.1 -74 33.6 belluomini et al., 2002 3.1 +1 waelbroek et al, 2002 3.3 -48 60.5 antonioli et al., 2004 3.3 deeper than -21 siddal et al 2003 3.3 -53 66 iannace et al., 2003 3-4 waelbroek et al, 2002 5.1 -19 81.5 dorale et al., 2010 81 ka +1 siddal et al 2003 5.1 -28 82.9 riccio et al., 2001, 2003; iannace et al., 2003, mastronuzzi 2007, hearty 1986, rodriguez vidal et al 2004 5.1 +1 and +5 waelbroek et al, 2002 5.3 -21 102 amorosi et al., 2004 5.3 -12 siddal et al 2003 5.3 -27 107 riccio et al., 2001; iannace et al., 2003, zazo et al 2009, rodriguez vidal et al 2004 5.3 between +6 and +2 m waelbroek et al, 2002 5.5 7 124 lambeck et al 2004, ferranti et al. 2006, 2010 5.5 between +6 and +8 m siddal et al 2003 5.5 17 123 waelbroek et al, 2002 6.5 -50 167 bard et al 2002 6.5 deeper than -22 m siddal et al 2003 6.5 -32 177 waelbroek et al, 2002 7.1 -10 189.7-201.5* bard et al., 2002, dutton et al., 2009* 7.1 above -18 m siddal et al 2003 7.1 -5 waelbroek et al, 2002 7.3 -4 206.0-217.2* dutton et al., 2009* 7.3 -18 m siddal et al 2003 7.3 -29 waelbroek et al, 2002 7.5 -9 231.0 – 248.9* dutton et al., 2009* 7.5 above -18 m siddal et al 2003 7.5 -3 waelbroek et al, 2002 9.1 -17 288 siddal et al 2003 9.1 -24 287 tab. 1 global sea level curves compared with predicted and observed sea level data in stable areas for western-central mediterranean sea. antonioli f. 18 stand peak was very likely to have exceeded 6.6 m and was likely to have been above 8.0 m although it is unlikely to have exceeded 9.4 m. according to siddal et al. (2010), the palaeosealevel data from farand medium-field sites for the lig period suggest that sl is attained close to its peak of 3–6 m above the modern sl by 126 kyr bp. pedoja et al. (2011) provided a compilation of 890 records of paleo-shoreline sequences for mis 5.5. they showed that “most coastal areas have risen relative to sea level with a mean uplift rate higher than 0.2 mm/a, more than four times, faster than the estimated eustatic drop in sl.” the study concludes that plate-tectonic processes affect all margins and emphasizes the fact that the notion of a stable platform is unrealistic. these results, therefore, “seriously challenge the evaluation of past sl from the fossil shoreline record.” in a recent paper, lambeck et al. (in press) demonstrated that “like their holocene counterparts, sl during earlier interglacials can be expected to exhibit considerable spatial variability that depends on the location of a site relative to ice margins of both the immediately preceding glacial maximum and of the last glacial maximum, and on the earth’s rheological response function response functions". their data show impressive differences (up to 15 m) for the lig highstand in stable coastal areas, such as australia, the caribbean, and red sea. in southern spain, zazo et al. (1999) found and studied many sites between +20 and +1.5 m sl, dated mis 5.5. for the italian coast, lambeck et al. (2004) assumed a “nominal” age of 1245 kyr and an elevation, in the absence of tectonics, of 73 m above the present sl. this elevation is higher than global estimates of this level because “the italian sites lie relatively close to the former ice margins and the present mis 5 shorelines in the mediterranean may lie a few meters higher than for localities much further from the former ice margins” (potter & lambeck, 2004). these values are consistent with observations of tidal notches from sardinia, southern lazio, campania, and western sicily, which are believed to have been tectonically stable during the recent glacial cycles. tidal notches, due to the low amplitude of tides in italy (a mean of about 40 cm, with the exception of ne adriatic and the gulf of gabes in tunisia), are considered the best sl markers. a recent compilation of mis 5.5 sea level markers on 246 sites spanning the coastline of italy (ferranti et al., 2006) allows the distinction between stable and tectonically active coastal areas since the late pleistocene (fig. 13 of this paper). figure 1 of ferranti et al. (2006) shows the distribution of mis 5.5 markers in the whole mediterranean sea that vary between 125 m (po plain, italy) and +190 m corinth, greece). this paper was implemented by new findings on the altitude of mis 5.5 highstand in tuscany and ne adriatic sea (antonioli et al., 2009; ferranti et al., 2010). data from tectonically stable sites confirm that the highstand altitude reached by the sea in italy during mis 5.5 was 7±2 m above the present sl. a compilation of new and published evidence related to mis 5 in southern spain (considered stable since 125 kyr bp) was published by bardaji et al. (2009), the authors concluded that “the palaeontological, sedimentological and geomorphological records of mis 5 deposits in the western mediterranean, allows the proposal of a model for the connections between this basin and high latitude climatic changes in the northern hemisphere, in comparison with modern analogues, in this paper authors published an eustatic curve for the lig” (fig. 3). mis 5.3 the global eustatic curves (waelbroek et al., 2002; siddal et al., 2003) indicate that the sea level during mis 5.3 was located respectively at -18.7 and -28 m (table 1). for mis 5.3, there are some observational data in the mediterranean in southern spain (zazo et al., 1999), which attribute to mis 5.3 some deposits (dated using the u/th method) at altitudes between +6 and 0 m. in the vicinity of gibraltar, considered stable since 125 ka, rodriguez-vidal et al. (2004) found deposits dated mis 5.3 at +5 m. in italy, a flowstone covering a marine conglomerate and lying a few meters above the present sl was attributed to mis 5.3 on the basis of u/th ages (riccio et al., 2001; iannace et al., 2001, 2003). transgressive lagoonal facies from the po plain (see core 240-s8 in amorosi et al., 2004) were assigned a mis 5.3 using the electron spin resonance (esr) method on mis 5.5 fig. 3 eustatic sea level curve for the last interglacial using mallorca data (gines et al., 2001), from bardaji et al. (2009). sea level change in western-central mediterranean since 300 kyr… 19 lagoonal deposit (ferranti et al., 2006). taking into account the present altitude of this deposit and the subsidence rates calculated using mis 5.5 (about 1 mm/yr), a relative sl of -12 m can be established for mis 5.3. the sediments of mis 5.3 (and 5.1) were not found in the veneto and friuli plain cores (north adriatic sea, antonioli et al., 2009; ferranti et al., 2010) affected by a negative tectonic between -0.6 and -0.4 mm\a. the authors interpreted this lack for the low seabed bathymetry of the north adriatic sea (about 10 m, some kilometres from the present coastline): a confirmation that the altitude of these mis was not higher than -15 m. mis 5.1 waelbroek et al. (2002) and siddal et al. (2003) indicated for mis 5.1 a sl located at -21.2 and -26.7 m, respectively (table 1). the observational data of mis 5.1 deposits from coral reefs in the caribbean sea seem to disagree with the g.slc. in particular, discrepancies are found in transects in stable areas for the coast of haiti, bermuda, bahamas, south carolina, and florida, with altitudes varying between -20 and +5 m. these controversial observations, however, are reconciled, taking into account the isostatic response of the earth due to the north american ice sheets melting during the last glacial cycle (potter & lambeck, 2004). in the vicinity of gibraltar, considered stable since 125 kyr, rodriguez-vidal et al. (2004) reported that deposits of mis 5.1 are found between +2 and +1.5 m. a mis 5.1 sea level at about +1 m was recorded using phreatic speleothem sampled in a partially submerged cave at mallorca in the western mediterranean (dorale et al., 2010). in southern italy, a marine deposit located a few meters above the present sea level and attributed to mis 5.1 based upon aar was reported by hearty (1986). in the grotta del diavolo (apulia, considered a stable coastal area) (ferranti et al. 2006, mastronuzzi et al. 2007) studied and dated some marine deposits covered by flowstone. the u/th age calculated for the continental deposit allowed us to establish that mis 5.1 is marked by a sea level position slightly higher than the present one. in the argentarola cave, the δ18o series on mis 5 of a marine layer (serpulids) conserved in a speleothem at -18.5 m shows a continued deposition during mis 5 (antonioli et al., 2004). the lack of any hiatuses on the marine layer allows us to establish that the sea level never fell below -22 m during mis 5.2 and 5.3. the presence of two closely spaced tidal notches, both attributed to mis 5.5, has been reported by antonioli et al. (2006) in sardinia (orosei gulf), a stable coastal area in italy. there is no evidence in these studied sites for tidal notches at altitudes lower than mis 5.5 (fig. 4). the observational altitude of mis 5.1 in the mediterranean sea sometimes disagrees with global sea level curves and remains a debated problem, which is also due to the lack of reliable isostatic models for mis 5. mis 3 for mis 3.3 and 3.1, waelbroek et al. (2002) indicated that the sea level was located at -39.5 and -60.5 m, fig. 4 orosei gulf, sardinia, italy the tidal and smoothed notches of the mis 5.5 highstand (see also antonioli et al., 2006). antonioli f. 20 respectively, whereas siddal et al. (2003) calculated the values -33.6 and -53 m for the same time intervals (table 1). data from the mediterranean sea are scarce for france. lambeck & bard (2000) wrote: “during stage 3, sea levels do not appear to have risen locally above about -60 m.” a marine deposit close to the present sea level was found in the taranto gulf (mis 5.5 between 3 and 20 m (ferranti et al., 2010) and dated to mis 3 using the aar method (belluomini et al., 2002). u/th dating of a flowstone overlying a marine conglomerate a few meters above sl allowed a correlation of the marine deposit to mis 3 (iannace et al., 2003) in campania in a stable coastal area. both findings disagree with global sea level curves. subsurface data from the po plain (cores published by amorosi et al., 1999, 2004) document that mis 3 is represented by paludal and alluvial facies, with no intervening marine deposits. the same occurs in the versilia plain (tyrrhenian sea, central italy) where carboni et al. (2010) studied the enea core up to -75 m. mis 2 for mis 2 (lgm), waelbroek et al. (2002) and siddal et al. (2003) located the sea level at -123 and 114 m, respectively (table 1). for the mediterranean side of france, lgm shorelines are reported between 105 and -115 m below the present level. this range reflects the importance of the isostatic contributions for southern france. predicted sl values for italy (lambeck et al., 2011), which take into account the effects of glacio-hydroisostatic movements, range between -130 and -108 m. lgm transgressive deposits recovered in a vibrocore sample on the shelf edge of sicily (termini imerese) at 129.5 m furnished an age of 21.8 kyr cal bp (caruso et al., 2011). these data agree with the local predicted sl curve by lambeck et al. (2011). mis 1 some paintings in the cosquer cave (marseille, france) aged 19 kyr cal bp, contained in the final portion of a flooded cave, demonstrate that the seal level maximum highstand was the present sl. (clottes et al., 1997; lambeck & bard, 2000): the legs of horses are painted at tide level, and the bottom was eroded by sea water. on the contrary, the remaining top is perfectly preserved. the holocene sea level change along the mediterranean coast during holocene is the sum of eustatic, glaciohydro-isostatic, and tectonic factors. the first is global and time dependent, while the latter two also vary with location. large collections of holocene data for france and italy, using different markers well connected with sl, were published by lambeck & bard (2000) and by lambeck et al. (2004). this large observational data set was compared with the predicted curves, leading to quantitative estimates of vertical tectonic movements (if present), identification of tectonically stable coastal areas, and paleogeographic reconstructions for the central mediterranean sea at different epochs. these predictions were then extended to the whole mediterranean sea (lambeck & purcell, 2005). a complete review of the holocene data, including the raw data files of the predicted sl data for 40 italian sites, has been published recently [see the supplementary material in lambeck et al. (2011)]. significant differences can be observed in stable coastal areas if different sites are considered: as an example, the sea level at 10 kyr cal bp varies along the italian coasts between -48 and -35 m, whereas at about 8 kyr cal bp, it ranges between -19 and -11 m (fig. 5). in a recent paper, pavlopulos et al. (2011) provided an extensive holocene data from the coast and islands of greece using archaeological and geomorphological markers. these observational data compared with predicted sea level curves (lambeck & purcell, 2005) allowed us to establish where the coast is stable, uplifting and downlifting, and to provide the tectonic rates. 3. discussion and conclusion we compared eustatic curves presenting different data with different accuracies (i.e., sea level during mis 3.3 set by waelbroeck at -39 m and by siddal at -33 m). there are uncertainties and error margins in the global eustatic sea level curves. figure 6 show the error bar of waelbroek et al. (2002). fig. 5 eustatic and glacio-hydro-isostatic prediction for selected sites in italy for the past 20 ka cal bp from lambeck et al.(2011). sea level change in western-central mediterranean since 300 kyr… 21 in stable coastal areas, data fit global curves in most cases, but there is a need for more reliable observational data sets in the mediterranean. also highlighting and resuming the efforts made in glaciohydro–isostatic, modeling can be a good thing to remember, along with what is needed (i.e., modeling of mis 5). for mis 9, no data are published for coastal areas stable in western-central mediterranean. with regard to mis 7.1, 7.3, and 7.5, data on age, duration, and elevation of the sea level are disposable for the central tyrrhenian sea. mis 7 appears to be below modern sea level, in agreement with global sea level curves. many observational data have been collected for mis 5.5 (ferranti et al., 2006). in sardinia, central mediterranean, well preserved tidal notches provide evidence that mis 5.5 highstand should be considered at 7±2 m. however, after the first published data (lambeck et al., in press) on isostasy during mis 5, it is possible that this is an average value for the central mediterranean sea and that models that take into account the effect of isostatic could modify this altitude in the near future, especially between north and south mediterranean. with regard to mis 5.3 and 5.1, data show in some coastal areas an altitude a few meters above sea level (southern spain mallorca, apulia, campania). on the contrary, with evidence in a core in the po plain, in the north adriatic sea cores, and in tidal notches of sardinia (antonioli et al., 2006), mis 5.3 seems to agree with global sea level curves. at present, it is not possible to determine if the discrepancies are linked to isostasy differences (as observed in other areas, see potter & lambeck, 2004), problems in the interpretation of markers, or problems in dating. mis 3 observational data are scarce and disagree with global sea level curves. for mis 3 the site in apulia is slight uplifting the sites in campania are stable could be possible some aging techniques problems. for mis 2, the predictions of the position of the lowstand for italy (lambeck et al., 2011) and central mediterranean (lambeck & purcell, 2005) were published. the only observational data (caruso et al., 2011) on the north sicilian continental shelf agree with the predictions (table 1). many data about italian continental shelves (chiocchi et al., 2004) described the lgm position at altitude compraised between -95 and -160 m, but these deposits are not radiocarbon aged. much work should be done especially to, i : retrieve observational data older than mis 7, ii : introduce isostasy during and after mis 5 in order to explain the disagreement found for mis 5.3 and 5.1, iii : provide tectonic ratea comparing the observational data to local sea level curves as clearly recomended by caputo (2007), on a paper for the use of global sea level curves. acknowledgements the author is grateful to l. ferranti and a. rovere for useful comments and revisions. references amorosi a., colalongo m.l., fiorini f., fusco f., pasini g., vaiani s.c., sarti g. (2004) palaeogeographic and palaeoclimatic evolution of the po plain from 150-ky core records. global and planetary change, 40, 55-78. amorosi a., colalongo m.l., fusco f., pasini g., fiorini f. (1999) glacio-eustatic control of continentalshallow marine cyclicity from late quaternary deposits of the south-eastern po plain (northern italy). quaternary research, 52, 1-13. fig. 6 global sea level curve from waelbroek et al. (2002) with error bars (in red). -180 -160 -140 -120 -100 -80 -60 -40 -20 0 20 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 age, ka r sl , m antonioli f. 22 antonioli f., bard e., silenzi s., potter e.k., improta s. (2004) 215 kyr history of sea level based on submerged speleothems. global and planetary change, 43, 57-68. antonioli f., dai pra g., p.j. hearty (1988) i sedimenti quaternari nella fascia costiera della piana di fondi. bollettino della società geologica italiana, 107, 491-501. antonioli f., ferranti l. (1996) evidenze geomorfologiche sommerse nelle aree costiere italiane di uno stazionamento del livello del mare a circa 20 m sotto l'attuale e attribuito allo stadio 3. il quaternario, 9(1), 205-208. antonioli f., ferranti l., fontana a., amorosi a.m., bondesan a., braitenberg c., dutton a., fontolan g., furlani s., lambeck k., mastronuzzi g., monaco c., spada g., stocchi p. (2009) holocene relative sea-level changes and vertical movements along the italian coastline. quaternary international, 221, 37-51. antonioli f., kershaw s., ferranti l. (2006) a double mis 5.5 marine notch? quaternary international 145-146, 19-29. bard e., antonioli f., silenzi s. (2002) sea-level during the penultimate interglacial period based on submerged stalagmite from argentarola cave (italy). earth and planetary science letters, 196/3-4, 135-146. bardají t., goy j.l. , zazo c., hillaire-marcel c., dabrio c.j., cabero a., ghaleb b., silva p.g., lario j. (2009) sea level and climate changes during ois 5e in the western mediterranean. geomorphology, 104, 22-37. berger a., (1978) long-term variations of caloric insolation resulting form the earth's orbital elements. quaternary research, 9, 139-167. belluomini g., caldara m., casini c., cerasoli m., manfra l., mastronuzzi g., palmentola g., sanso p., tuccimei p., vesica p.l. (2002) the age of late pleistocene shorelines and tectonic activity of taranto area, southern italy. quaternary science reviews, 21, 525-547. capozzi r., negri a. (2009) role of sea-level forced sedimentary processes on the distribution of organic carbon-rich marine sediments: a review of the late quaternary sapropels in the mediterranean sea. palaeogeography, palaeoclimatology, palaeoecology, 273, 249-257. caputo r. (2007) sea-level curves: perplexities of an end-user in morphotectonic applications. global and planetary change, 57, 417-423 carboni m., bergamin l., di bella l., esu d., pisegna e., cerone b., antonioli f., verrubbi v. (2010) palaeoenvironmental reconstruction of late quaternary foraminifera and molluscs from the enea borehole (versilian plain, tuscany, italy). quaternary research, 74, 265-276. caruso a., cosentino c, pierre c, sulli a. (2011) sealevel changes during the last 41,000 years in the outer shelf of the southern tyrrhenian sea: evidence from benthic foraminifera and seismostratigraphic analysis. quaternary international, 232, 122-131. chiocci f.l., d’angelo s., romagnoli c. (a cura di) (2004) atlante dei terrazzi deposizionali sommersi lungo le coste italiane, memorie descrittive della carta geologica d’italia, lviii, 2004, 197 pp. clottes, j. courtin, j., collina-girard, m. arnold, h. valladas m. (1997) news from cosquer cave: climatic studies recording, sampling, dates. antiquity, 71, 321-326. de santis v., caldara m., trinidad de torres b., ortiz j. (2010) stratigraphic units of the apulian tavoliere plain (southern italy): chronology, correlation with marine isotope stages and implications regarding vertical movements. sedimentary geology, 228, 255-270. dorale j., p. onac b., fornós j., ginés j., ginés a., tuccimei p., david w., peate d. (2010) sealevel highstand 81,000 years ago in mallorca. science, 327, 860-863. dutton a., antonioli f., bard e., esat t.m., lambeck k., mcculloch m. (2009) phasing and amplitude of sea level and climate change during the penultimate interglacial. nature geosciences, 355-359. esat t.m., mcculloch m.t., chappell j., pillans b., omura a. (1999) rapid fluctuations in sea level recorded at huon peninsula during the penultimate deglaciation. science, 283, 197-201. gallup c.d., cheng h., taylor f.w., edwards r.l. (2002) direct determination of the timing of sea level change during termination ii. science, 295, 310-313. ginés j., fornós j.j., ginés a., gracia f., delitalia c., taddeucci a., tuccimei p., vesica p.l. (2001) els espeleotemes freàtics de les coves litorals de mallorca: canvis del nivell de la mediterránia i paleoclima en el pleistocé superior. in: pons, g.x., guijarro, j.a. (eds.), el canvi climàtic: passat, present i futur. societat d'història natural de les balears, 9, 33-52. ferranti l., antonioli f., amorosi a., dai prà g., mastronuzzi g., mauz b., monaco c., orrù p., pappalardo m., radtke u., renda p., romano p., sansò p., verrubbi v. (2006) elevation of the last interglacial highstand in italy: a benchmark of coastal tectonics. quaternary international, 145,146, 30-54. ferranti l., antonioli f., anzidei m., monaco c., stocchi p. (2010) the timescale and spatial extent of vertical tectonic motions in italy: insights from relative sea-level changes studies. journal of the virtual explorer, electronic edition, issn 1441-8142, 36, paper 30. kent d.v., rio d., massari f., kukla g., lanci l. (2002) emergence of venice during the pleistocene. quaternary science reviews, 21, 1719-1727. kopp r., frederik j. simons, jerry x. mitrovica, adam c., oppenheimer m. (2009) probabilistic assessment of sea level during the last interglacial stage. nature, 462, 863-867. hearty p.j. (1986) an inventory of last interglacial (sensulato) age deposits from the mediterranean basin:a study of isoleucine epimerization and useries dating. z. geomorph. n.f., supplementband 62,51-69. iannace a., romano p., santangelo n., santo a., tuccimei p. (2001) the ois 5c along licosa cape promontory (campania region, southern italy): morphostratigraphy and u/th dating. z. geomorph. n.f., 45(ii), 307-319. sea level change in western-central mediterranean since 300 kyr… 23 iannace a., romano p., tuccimei p. (2003) u/th dating and geochenmistry of carbonate concretions associated with upper pleistocene fossils shorelines of the sorrento peninsula (conca dei marini, southern italy). il quaternario, 16 bis, 38-49. imbrie j., hays j.d., martinson d.g., mcintyre a., mix a.c., morley j.j., pisias n.g., prell w.l., shackleton n.j. (1984) the orbital theory of pleistocene climate: support from a revised chronology of the marine δ18o record. in: berger, a.l., et al., (ed.), milankovitch and climate, part1. reidel, 269-305. ipcc (2007) summary for policymakers. contribution of working group i to the fourth assessment report of the intergovernmental panel on climate change. in: solomon, s., qin, d., manning, m., chen, z., marquis, m., averyt, k.b., tignor, m., miller, h.l. (eds.), climate change 2007: the physical science basis. cambridge university press, cambridge, united kingdom and new york, ny, usa. lambeck k, antonioli f., anzidei m., ferranti l., leoni g., scicchitano g., silenzi s. (2011) sea level change along italian coast during holocene and a proiection for the future, quaternary international, 232(1-2), 250-257. lambeck k., antonioli f., purcell a., silenzi s. (2004) sea level change along the italian coast for the past 10,000 yrs. quaternary science revue, 23, 1567-1598. lambeck k., bard e. (2000) sea-level change along the french mediterranean coast since the time of the last glacial maximum. earth andplanetary science letters, 175, 203-222. lambeck k., dutton a., purcell a. (in press, 2011) the anatomy of interglacial sea levels: the relationship between sea levels and ice volumes during the last interglacial, earth and planetary science letter. lambeck k., purcell a., (2005) sea-level change in the mediterranean sea since the lgm: model predictions for tectonically stable areas. quaternary science reviews, 24, 1969-1988. mastronuzzi g., quinif y., sansò p., selleri g. (2007) middle-late pleistocene polycyclic evolution of a stable coastal area (southern apulia, italy). geomorphology, 86, 393-408. miyauchi, t., dai pra g., sylos labini s. (1994) geochronology of pleistocene marine terraces and regional tectonics in the tyrrhenian coast of south calabria, italy. il quaternario, 7 (1), 17-34. pavlopoulos, k., kapsimalis v., theodorakopoulou k., panagiotopoulos i.p. (2011) vertical displacement trends in the aegean coastal zone (ne mediterranean) during the holocene assessed by geoarchaeological data. the holocene, 21 (1), 1-12 pedoja k., husson l., regard v., cobbold p., ostanciaux e., johnson m., kershaw s., saillard m., martinod j., furgerot l., weill p., delcaillau b. (in press, 2011) relative sea-level fall since the last interglacial stage: are coasts uplifting worldwide? earth science reviews, doi: 10.1016/j.earscirev.2011. 05.002. potter e., lambeck k. (2004) reconciliation of sealevel observations in thewestern north atlantic during the last glacial cycle. earth and planetary science letters, 217, 171-181. riccio a., riggio f., romano p. (2001) sea level fluctuations during oxygen isotope stage 5: new data from fossil shorelines in the sorrento peninsula (southern italy). z. geomorph. n.f., 451, 121-137. richards d.a,. smart p.l, edwards r.l. (1994) maximum sea levels for the last glacial period from useries ages of submerged speleothems, nature, 367, 357-360. rodrıguez-vidal j., caceresa l.m., finlayson j.c., graciac f.j., martiınez-aguirred a. (2004) neotectonics and shoreline history of the rock of gibraltar, southern iberia quaternary science reviews, 23, 2017-2029. rovere, a., vacchi, m., firpo, m., carobene, l., 2011. underwater geomorphology of the rocky coastal tracts between finale ligure and vado ligure (western liguria, nw mediterranean sea). quaternary international 232, 187-200. shackleton, n. j., sánchez-goñi, m. f., pailler d., and lancelot y. (2003) marine isotope substage 5e and the eemian interglacial: global and planetary change, 36, 151-155. siddall m, abe-ouchi a, andersen m, antonioli f., bamber j, bard e, clark j, clark p, deschamps p, dutton a, elliot m, gallup c, gomez n, gregory j, huybers p, kawarnura k, kelly m, lambeck k, lowell t, milrovica j, otto-bliesner b, richards d, stanford j, stirling c, stocker t, thomas a, thompson b, tornqvist t, riveiros nv, waelbroeck c, yokoyama y, yu sy (2010). the sealevel conundrum: case studies from palaeo-archives journal of quaternary science, 25, 19-25. siddall m., rohling e.j., almogi-labin a., hemleben ch., meischner d., schmelzer i. (2003) sea level fluctuations during the last glacial cycle. nature, 423, 853-858. stirling, c.h., esat, t.m., lambeck, k., mcculloch, m.t. (1998) timing and duration of the last interglacial: evidence for a restricted interval of widespread coral reef growth. earth and planetary science letters, 160, 745-762. zazo c. silva p.g., goyb j.l., hillaire-marcel c., ghaleb b., lario, j., bardajı´ t. gonzalez a. (1999) coastal uplift in continental collision plate boundaries: data from the last interglacial marine terraces of the gibraltar strait area (south spain). tectonophysics, 301, 95-109. waelbroeck c., labeyrie l., michel e., duplessy j.c., lambeck k., mcmanus j.f., balbon e., labracherie, m. (2002) sea-level and deep water temperature changes derived from benthic foraminifera isotopic records. quaternary science reviews, 21, 295-305. westaway r., 1993. quaternary uplift of southern italy. journal of geophysical research, 98, 2174121772. ms. received: january 22, 2012 final text received: february 21, 2012 evoluzione sedimentaria della successione alluvionale e lacustre quaternaria del bacino di venosa (italia meridionale) paolo giannandrea dipartimento di geologia e geofisica centro interdipartimentale di ricerca per la valutazione e mitigazione del rischio sismico e vulcanico, università degli studi di bari giannandrea@geo.uniba.it riassunto: giannandrea p., evoluzione sedimentaria della successione alluvionale e lacustre quaternaria del bacino di venosa (italia meridionale). (it issn 0394-3356, 2009). con la sedimentazione dei depositi della formazione dei conglomerati di irsina l’area di avanfossa plio-pleistocenica (fossa bradanica), compresa tra la catena sudappenninica tratto in cui affiorano i depositi vulcanici di monte vulture e l’avampaese apulo, passa da area in subsidenza ad area in sollevamento. nella fase di sollevamento si alternarono periodi di modellamento a periodi deposizionali; questi ultimi sono legati anche all’apporto di sedimenti vulcanici provenienti dal vulcano vulture. nella stessa fase si forma la paleovalle del bacino di venosa (bv) impostata su una serie di faglie distensive a componente trascorrente, orientate in direzione n110°±5°, n130° ed est, ovest. nella prima fase di modellamento della paleovalle si formano tre ordini di terrazzi alluvionali (subsintemi di ciciriello, pezza della breccia e masseria impiso) raggruppati nel sintema di sant’angelo. nel successivo evento deposizionale si forma, con spessore variabile da circa 35 m a poco più di 80 m, la successione del bv costituita da terreni a composizione prevalentemente vulcanica, di ambiente alluvionale e in minore percentuale lacustre, con subordinati strati di vulcaniti primarie di flusso piroclastico e di caduta separati da superfici di discontinuità. queste ultime, associate a discordanze angolari sin sedimentarie e a spessi paleosuoli, permettono di suddividere la successione epiclastica in tre sintemi correlati, attraverso markers vulcanici, ai sintemi di foggianello, barile e melfi, già distinti al monte vulture, e di raggrupparli insieme al sintema di sant’angelo nel supersintema di monte vulture (età compresa tra 687±8 ka e 530±22 ka). lo studio dei caratteri deposizionali della successione epiclastica permette di attribuire i depositi del sintema di foggianello a una piana alluvionale ghiaiosa di tipo braided, con paleo flusso nei quadranti orientali, e i depositi del sintema di barile a piccoli bacini lacustri alimentati da canali ad elevata sinuosità. segue una fase di intensa attività tettonica espressa nel bv da faglie sub-verticali orientate in direzione n90°±5° e n103°±2° su cui si imposta la successiva fase di reincisione dei depositi epiclastici. in questa ultima fase l’accrescimento del reticolo idrografico del fiume ofanto determina la cattura delle acque del bv e la formazione di altri tre episodi deposizionali individuati da tre unità terrazzate. due delle tre unità (subsintemi di toppo di maggio e li scafoni) sono comprese nel sintema del torrente olivento e una nel sintema di caperroni; i due sintemi sono compresi nel supersintema di monticchio. alle tre fasi evolutive, infine, sono stati associati schemi paleogeografici, suddivisi per sintema, che consentono di raffigurare le fasi di modellamento, sedimentazione e reincisione del bv dal pleistocene medio al pleistocene superiore. abstract: giannandrea p., sedimentary evolution of the lacustrine and alluvial quaternary succession of venosa basin (southern italy). (it issn 0394-3356, 2009). the bradano trough area, included in the watershed of venosa river, passed from subsidence to regional tectonic uplift with the sedimentation of the irsina conglomerate formation. this period (middle pleistocene in age), which was characterized by an alternance of erosional and depositional phases developed on a series of direct faults with a strike-slip component (direction n110°±5°, n130° and east,west) and formed the venosa basin palaeovalley. the first erosive phase led to the formation of three alluvial terraces (ciciriello, pezza della breccia and masseria impiso subsynthem) which can be grouped into the sant'angelo synthem. the following depositional event was characterized by the emplacement of alluvial and lacustrine deposits consisting of conglomerate, mudstone and tuff, which can be grouped into three synthems bounded by stratigraphic unconformities. sediment composition is mainly volcanic detritus with minor layers of primary volcanic deposits (pyroclastic flow and fall deposits) which can be correlated with the foggianello, barile and melfi synthem, of monte vulture volcano. the three epiclastic units and the sant'angelo synthem have been grouped into the monte vulture supersynthem (from 687±8 ky to 530±22 ky in age). analysis of the sedimentary facies reveals that the foggianello synthem formed in a depositional system of gravelly braided plains and the barile synthem formed in small lake basins connected with high sinuosity channels. after the melfi synthem sedimentation, on the north-western border of the venosa basin, sub-vertical direct faults formed (direction n90°±5° and n103°±2°). concurrently a new erosional phase, connected with three depositional episodes, occurred. it led to the formation of alluvial deposits that are linked to three terraced stages of fluvial overcutting. two out of the three units (li scafoni and toppo di maggio subsynthem) are included in the torrente olivento synthem and the other one in the caperroni synthem. the two synthems are associated with the monticchio supersynthem. a palaeogeographic scheme is provided for each synthem, which allows the representation of the evolution of erosion and sedimentation of the venosa basin deposits from middle pleistocene to upper pleistocene. parole chiave: depositi continentali, vulcanismo quaternario, paleogeografia, italia meridionale. keywords: continental deposits, quaternary volcanism, palaeogeography, southern italy. il quaternario italian journal of quaternary sciences 22(2), 2009 269-290 1. introduzione sul fronte esterno della catena sudappenninica si individua, in corrispondenza di un fascio di faglie antiappenniniche (“linea del vulture”, sc h i a t t a r e l l a e t a l., 2005), il vulcano mediopleistocenico di monte vulture (fig. 1). nelle aree periferiche dell’edificio i prodotti vulcanici sono in rapporto di eteropia di facies con depositi epiclastici di ambiente alluvionale e/o lacustre associati a bacini sedimentari ad esso adiacenti (de lo r e n z o, 1900; gi a n n a n d r e a et al., 2006). gli apporti vulcanici sono abbondanti e si estendono per alcune decine di chilometri oltre l’area di dispersione delle vulcaniti primarie, che si è sviluppata ad oriente del vulcano dove si snodava la paleovalle del bacino di venosa. tale paleovalle, incassata per circa 130 m nei sedimenti 270 p. giannandrea della fossa bradanica, risulta colmata per 2/3 della sua altezza da depositi alluvionali e lacustri, di natura prevalentemente vulcanica, sedimentati contemporaneamente alle fasi di attività del vulture (cagnazzi, 1807; sacchi & pa l m i e r i, 1852; de lo r e n z o, 1900; pi c c a r r e t a & ri c c h e t t i, 1970; se g r e, 1978; bo n a d o n n a et al. , 1 9 9 8 ; ra y n a l et al., 1998; pi p e r n o, a cura di, 1999). tra i 271evoluzione sedimentaria della successione alluvionale e lacustre ... depositi epiclastici sono presenti livelli vulcanici primari e superfici di discontinuità che consentono la definizione di tre unità stratigrafiche a limiti inconformi correlabili con l’attività del monte vulture che ha deposto le unità eruttive comprese nei sintemi di foggianello, barile e melfi (fig. 2; gi a n n a n d r e a, 2006 a; b). le due successioni affioranti al monte vulture e nel bv risultano deforfig. 2 schema stratigrafico delle unità sintematiche cartografate del bacino idrografico della fiumara di venosa e del vulcano di monte vulture. (1) età radiometrica da buettner et al, 2006. stratigraphical sketch of the mapped chartographic units of venosa rivers hydrographical basins and monte vulture volcano. (1) radiometric age (from buettner et al, 2006). 272 mate da strutture tettoniche ad attività sin sedimentaria. le strutture rilevate sul vulcano presentano differenti caratteri cinematici che permettono di distinguere tre diversi stadi tettono-evolutivi (schiattarella et al., 2005 e bibl. contenuta). questa nota, che utilizza dati raccolti in recenti lavori di rilevamento, da cui è anche scaturita la pubblicazione della carta geologica alla scala 1:25.000, allegata a questo volume (carta geologica del bacino di venosa, giannandrea, 2006a), ha lo scopo di ricostruire le variazioni sedimentologiche avvenute durante la formazione del bv e di proporre alcuni schemi dell’evoluzione paleogeografica dell’area. le ricerche nel bv sono state realizzate a completamento degli studi, finalizzati al rilevamento geologico dell’area vulcanica di monte vulture. 2. inquadramento geologico il bv è rappresentato da una paleovalle modellata nei depositi della fossa bradanica dalle pendici del monte vulture all’abitato di irsina (fig. 1). la paleovalle è orientata nella parte occidentale in direzione e, o, mentre si sviluppa con andamento no, se in quella orientale. la larghezza varia da circa 4,5 km, nel settore occidentale, a poco più di un chilometro in quella orientale. la fossa bradanica rappresenta il segmento meridionale dell’avanfossa appenninica (se l l i, 1962; d’argenio et al., 1973), riempita da una successione di depositi plio-pleistocenici spessa qualche chilometro. nel tratto lucano l’asse del bacino è allungato in direzione no-se ed è compreso fra la catena appenninica a sud-ovest e l’avampaese apulo a nord-est (fig. 1). la parte medio-bassa della successione (pliocene medio) è composta da terreni di mare profondo, prevalentemente torbiditici (ba l d u z z i et al., 1982; ca s n e d i et al., 1982; ca s n e d i, 1988), mentre la parte alta (pliocene superiore – pleistocene inferiore), è caratterizzata da alcune centinaia di metri di sedimenti argillosi, riferibili alla formazione delle argille subappennine in transizione, verso l’alto, a depositi regressivi sabbiosi (sabbie di monte marano) e conglomeratici (conglomerati di irsina) deltizi, di spiaggia ed alluvionali (ricchetti, 1965; 1967; az z a r o l i et al., 1968a; 1968b; bo e n z i et al., 1971a; 1971b; valduga, 1973; pieri et al., 1994; 1996; patacca & sc a n d o n e, 2001). i depositi regressivi sono anche associati a più sistemi deposizionali progradanti, nel settore settentrionale, in direzione ne e nel settore meridionale in direzione se (pieri et al., 1996; sabato et al., 2004). tra le due successioni è intercalato un cuneo di coltri appenniniche (ba l d u z z i et al., 1982), che permette di individuare, al passaggio tra il pliocene medio e il pliocene superiore, una discontinuità stratigrafica che correla le due successioni a coevi depositi del bacino dell’ofanto (fig. 1; fig. 3; giannandrea, 2006a; b). inoltre, alla base dei depositi regressivi sabbiosoconglomeratici di colmamento dell’avanfossa, nel tratto affiorante nella valle della fiumara di venosa (fig. 3), è possibile distinguere una superficie erosiva modellata sulle argille pleistoceniche che, insieme alla soprastante superficie di modellamento della paleovalle del bv, definiscono i limiti di discontinuità del supersintema di venosa (giannandrea, 2006a). il fronte esterno dell’appennino lucano è costituito da successioni argilloso-arenaceo-calcaree mesocenozoiche organizzate in più unità tettoniche sovrapposte con vergenza adriatica (fig. 3; pe s c a t o r e & fig. 3 sezione schematica dei rapporti tettono-stratigrafici delle unità affioranti nel settore esterno dell’appennino meridionale e della fossa bradanica. per l’ubicazione vedi figura 1. schematic cross-section of the tectono-stratigraphic relationships among the external structural units of the southern apennines and bradano trough (location in figure 1). p. giannandrea 273 ortolani, 1973; mostardini & merlini, 1986; casero et a l., 1988; 1992; pa t a c c a & sc a n d o n e 1989; 2001; lentini et al., 1990; 1996; patacca et al., 1990; ortolani et al., 1992; hippolyte et al., 1994; finetti et al., 1996; pr o s s e r et al., 1996; pe s c a t o r e et al., 1999; gi a nn a n d r e a, 2006b) ed appartenenti alle unità del bacino lagonegrese-molisano (mo s t a r d i n i & me r l i n i, 1986) e dell’avanfossa miocenica (unità irpine, co c c o et al. , 1972; pescatore, 1978). le variazioni stratigrafico-sedimentarie del margine appenninico della fossa bradanica sono legate all’evoluzione tettonica plio-pleistocenica del fronte della catena e alla subsidenza del substrato carbonatico della piattaforma apula. quest’ultima è attraversata da faglie di trasferimento ad andamento antiappenninico di importanza litosferica, che la suddividono in più blocchi a dif ferente velocità di subsidenza (or t o l a n i et al., 1992). una delle faglie individuate si identifica con la linea del vulture (sc h i a t t a r e l l a et al., 2005) che, nel pleistocene medio, rappresenta lo svincolo cinematico ed il sollevamento del la fossa bradanica e dell’avampaese apulo (ci a r a n f i et al., 1983; pi e r i et al., 1994; do g l i o n i et al., 1996) ed ha consentito la risalita dei magmi che hanno alimentato il vulcano di monte vulture (sc h i a t t a r e l l a et al., 2005). strutture tettoniche minori trasversali alla catena sono anche responsabili della formazione e delle variazioni del reticolo idrografico del bv (pi c c a r r e t a & ri c c h e t t i, 1 9 7 0 ; se g r è, 1978; ci a r a n f i et al., 1983; bo e n z i et al., 1 9 8 7 ) . l’edificio vulcanico di monte vulture si imposta su una paleogeografia alluvionale modellata sulle coltri appenniniche e sui depositi plio-pleistocenici del bacino dell’ofanto (gi a n n a n d r e a et al. , 2004; 2006). le vulcaniti che lo compongono hanno una età compresa tra 687±8 ka e141±11 ka (bu e t t i n e r et al., 2006; pr i n c i p e & gi a n n a n d r e a, 2008) e sono caratterizzate da successioni piroclastiche, rappresentate da depositi di caduta (pomici e lapilli), flussi concentrati (p y r o c l a s t i c flow, ash flow, pumice and ash flow, block and ash f l o w) e diluiti (s u r g e), cui si associano flussi di massa (l a h a r ) e lave, che costituiscono un edificio centrale e numerosi piccoli centri secondari disseminati alla periferia del vulcano e sul substrato sedimentario. le lave possono essere sia sottili intercalazioni, sia spesse successioni concentrate in aree ristrette e, a luoghi, costituire dicchi e duomi lavici. la successione di vulcanit i è suddivisa in c inque sintemi (sintemi di foggianello, barile, melfi, valle dei grigi – fosso del corbo, laghi di monticchio) nei quali sono raggruppati numerosi subsintemi (gi a n n a n d r e a et al. , 2004; gi a n n a n d r e a et et al., 2006; pr i n c i p e & gi a n n a n d r e a, 2008), a causa della presenza di numerose discontinuità stratigrafiche, rappresentate da significative superfici erosive, paleosuoli e depositi epicalstici. i sintemi riconosciuti sono a loro volta raggruppati nei supersintemi di monte vulture e di monticchio (fig. 2). il supersintema di monte vulture comprende la maggior parte dei prodotti emessi dal vulture, suddivisi nei sintemi di foggianello, barile e melfi, mentre il supersintema di monticchio, suddiviso nei sintemi della valle dei grigi – fosso del corbo e dei laghi di monticchio, comprende vulcaniti poco estese lateralmente, associabili a piccoli centri distribuiti alla periferia del vulcano e sul substrato sedimentario. 3. stratigrafia dei depositi terrazzati affioranti nelle valli della fiumara di venosa e del torrente olivento lungo le valli della fiumara di venosa e del torrente olivento affiorano, sospesi rispetto ai fondovalle attuali, oltre a depositi epiclastici del bv, unità alluvionali terrazzate (fig. 4). la ricostruzione stratigrafica di queste unità è stata realizzata attraverso un profilo morfostratigrafico rettificato tracciato lungo le due valli (fig. 5). sul profilo sono state proiettate: i) la superficie di tetto dei depositi plio-pleistocenici della fossa bradanica, ii) le superfici di appoggio basale dei depositi terrazzati e di quelli del bv, iii) due discontinuità rilevate internamente ai depositi del bv, e iiii) la superficie deposizionale di tetto dei depositi del bv. lo schema stratigrafico che si delinea permette di inquadrare la successione del bv tra due serie di unità alluvionali terrazzate (fig. 5) e di riferirne l’età di formazione ad un periodo compreso tra 687±8 ka e 530±22 ka (fig. 2). la prima serie è costituita da tre unità terrazzate le cui superfici di appoggio sono modellate, nei terreni dell’avanfossa (fig. 4), a quote più elevate rispetto alla superficie di colmamento del bv (fig. 5). le tre unità sono rappresentate dai subsintemi di ciciriello, pezza della breccia e masseria impiso e raggruppate nel sintema di s. angelo (fig. 5). i tre subsintemi sono costituiti da alcuni metri di conglomerato alluvionale privo di detrito vulcanico. le ghiaie sono clasto-sostenute massive, con ciottoli a composizione, esclusivamente carbonatica (calcareniti e brecce calcaree) nel subsintema di pezza della breccia, e arenacea, calcareo-marnosa, marnosa, calcarenitica e calcarenitica con noduli di selce nei subsintemi di masseria impiso e di ciciriello. dei tre subsintemi, quello di ciciriello affiora nella valle della fiumara di venosa (fig. 4; fig. 5), alla quota di 340 m s.l.m., mentre quelli di pezza della breccia e masseria impiso sono sul versante sinistro della valle del torrente olivento, rispettivamente alle quote di 300 m s.l.m. e di 220 m s.l.m. seguono i depositi del bv rappresentati in affioramento da una successione aggradazionale fining upward, dello spessore variabile da circa 35 m a poco più di 80 m, di sedimenti epiclastici alluvionali e lacustri e subordinatamente da prodotti vulcanici di flusso piroclastico e di caduta (fig. 6; tab. 1; tab. 2). la superficie di appoggio basale del bv si individua ad alcuni metri sul fondovalle attuale della fiumara di venosa (fig. 5) e, a luoghi (località: piano di regio; fig. 4), scende sotto l’attuale superficie deposizionale (fig. 5). la superficie deposizionale di tetto del bv si articola dalla quota di circa 380 m s.l.m., vicino l’abitato di palazzo s. gervasio, alla quota di circa 350 m s.l.m., nel punto di confluenza della fiumara di venosa con il torrente olivento (fig. 5), dove si correla alle superfici deposizionali dei subsintemi di solagne arcidiaconata e di piano di croce, riconosciuti tra gli abitati di barile e rapolla al monte vulture (gi a n n a n d r e a et al., 2004). internamente alla successione del bv sono presenti due superfici di discontinuità, che consentono di suddividerla nei sintemi di foggianello, barile e melfi. la discontinuità che separa il sintema di foggianello dal sintema di barile è individuata a tetto delle coltri ignimbritiche di fara d’olivo di crisci et al., 1983, da cui è separata da qualche metro di conglomerati alluvionali (fig. 7a). a luoghi evoluzione sedimentaria della successione alluvionale e lacustre ... 274 p. giannandrea 275evoluzione sedimentaria della successione alluvionale e lacustre ... 276 p. giannandrea 277 tab. 1 classificazione delle facies sedimentarie e loro interpretazione. sedimentary facies classification and interpretation. sigla descrizione interpretazione gcm ghiaia clasto-sostenuta massiva, senza ciottoli colata di detrito pseudoplastico (debris-flow); flussi embricati, con a luoghi superficie erosiva alla base. inerziali, flussi turbolenti (miall, 1996); flussi i perconcentrati (pierson, 1980; smith, 1986). energia, flusso viscoso (miall, 1996). gmm ghiaia fango-sostenuta massiva colata di fango e detrito (debris-flow) legati a flussi ad alta viscosità (miall, 1996). gcp ghiaia clasto e matrice sostenuta, a stratificazione accrescimento laterale di barre ghiaiose (miall, 1992). planare obliqua, con ciottoli embriciati e gradazione diretta. gch ghiaia clasto e matrice-sostenuta, con debole flussi ghiaiosi in regime supercritico non incanalato; stratificazione orizzontale, con o senza ciottoli lag deposit, barre longitudinali, lobi setaccio (miall, embricati. 1996). ap cenere media a stratificazione incrociata piana. flussi di cenere in regime sub-critico. barre linguoidi, trasversali, onde di sabbia (dune 2-d, miall, 1996), alt cenere, da media a grossa, e lapilli, a laminazione flussi di cenere e lapilli in regime di flusso sub-critico; incrociata concava. riempimento di docce di erosione, migrazione di dune (miall, 1996). alm cenere da media a grossa massiva oppure gradata, colata di cenere e, a luoghi, lapilli (lahar); caratterizzata con o senza lapilli. da un flusso turbolento ad alta concentrazione da cui si ha una rapida caduta di sedimento (smith, 1986) nella fase di energia calante (dreyer, 1993) alh cenere da media a grossa a laminazione orizzontale letti planari in regime di flusso critico (sheet flood). con o senza lapilli. (miall, 1996), migrazione di dune molto piatte (jopling, 1967; smith, 1971; mcbride et al., 1975). ar cenere da media a fine a laminazione incrociata da migrazione di ripples (miall, 1996) in regime di flusso ripples. sub-critico. almf cenere fine da laminata a massiva. flussi di tracimazione (over-bank) (miall, 1996; walker 1967; van houten, 1968; besley & turner, 1983) o di piena calante (waning). fsm argilla e silt da laminati a massivi con bioturbazioni decantazione con debole trazione (miall, 1996); da radici e gasteropodi continentali. depositi di palude. c limi calcarei massivi o con lamine orizzontali e, a precipitazione chimica in ambiente lacustre o luoghi, gasteropodi continentali. fluvio-lacustre (piccarreta & ricchetti, 1970). p sabbia siltose rossastra massiva e a struttura paleosuolo. granulare, con ciottoli millimetri e abbondanti pori millimetrici, con a luoghi noduli calcitici. tab. 2 classificazione delle facies vulcaniche e loro interpretazione. volcanic facies classification and interpretation. sigla descrizione interpretazione gbcm blocchi di lava clasto-sostenuti massivi, con clasti franamento di materiale vulcanico caldo. metrici a fratturazione perpendicolare alla superficie esterna. mb breccia clasto-sostenuta massiva, con lapilli deposito prossimale. (pomici e litici) e blocchi (esclusivamente sedimentari). malm cenere massiva a struttura omogenea o complessa, sedimentazione in massa da un flusso piroclastico con lapilli. (pyroclastic flow). laaccr cenere fine laminata con lapilli acrezionari. flusso piroclastico di cenere e lapilli acrezionari (pyroclastic ash flow) in regime di flusso critico e con elevata umidità na cenere da fine a finissima gradata. caduta in acqua, con decantazione. ma cenere da media a fine massiva. deposito di caduta (fall deposit). mlc lapilli clasto-sostenuti, privi di matrice, massivi. deposito di caduta (fall deposit). evoluzione sedimentaria della successione alluvionale e lacustre ... tale discontinuità fossilizza strutture tettoniche a componente diretta (fig. 13). la discontinuità che separa il sintema di barile dal sintema di melfi è individuata a tetto di uno spesso paleosuolo (fig. 7b). il sintema di foggianello ha uno spessore variabile, da occidente ad oriente, da 23 m a 10 m (fig. 6) ed è composto prevalentemente da conglomerati alluvionali. alla base dell’unità, per qualche metro di spessore, i conglomerati sono silicoclastici, privi di detrito vulcanico. seguono conglomerati a composizione prevalente silicoclastica, con matrice sabbiosa a forte componente vulcanica. tra le ghiaie sono presenti rari ciottoli vulcanici di cui alcuni trachi-fonolitici (de fino et al., 1982). nella parte alta dell’unità, ai conglomerati sono intercalati prodotti vulcanici di flusso piroclastico (fig. 6), con litologie analoghe a quelle delle coltri ignimbritiche di fara d’olivo di cr i s c i et al. (1983). i conglomerati sovrastanti le ignimbriti risultano arricchiti di pomici bianche e di ciottoli e blocchi, anche di grandi dimensioni, derivanti dall’erosione delle sottostanti piroclastiti. l’età del sintema è riferibile al pleistocene medio, compresa all’incirca tra 687 ± 8 ka e 673 ± 19 ka (fig. 2; pr i n c i p e & gi a nn a n d r e a, 2008). il soprastante sintema di barile comprende circa 30 m di depositi tufitici prevalentemente in f a c i e s alluvionali e lacustri, in minore percentuale prodotti vulcanici sia di flusso che di caduta di età compresa tra 673 ± 19 ka e 624± 35 ka (fig. 2). nel settore assiale del bacino l’unità può raggiungere lo spessore massimo di 43 m e contenere alla base alcuni metri di conglomerati alluvionali con blocchi metrici di lave. i depositi del bv terminano con il sintema di melfi costituito da depositi colluviali, ceneri fini, fanghi e travertini per uno spessore massimo di 5 m riferibili ad una età di circa 557± 7 ka (fig. 2). a quote più basse rispetto alla superficie di colmamento del bv, con superficie erosiva di appoggio basale modellata nei depositi epiclastici del bv, si distingue la seconda serie di unità terrazzate. quest’ultima è costituita da tre unità alluvionali di cui due sono distinte come subsintemi di toppo di maggio e li scafoni e raggruppati nel sintema del torrente olivento. il subsintema di toppo di maggio affiora solo tra le località le mangiatoie e piano regio (fig. 4) su entrambi i versanti della valle, circa 45 m sopra l’attuale fondo valle della fiumara di venosa (fig. 5). il successivo subsintema li scafoni affiora lungo tutta la valle della fiumara di venosa e in parte nella valle del torrente olivento ed è costituito da depositi alluvionali terrazzati, sospesi sul fondovalle attuale, da monte a valle, da 40 m a 27 m. i depositi dei due subsintemi sono costituiti rispettivamente da poco più di un metro di cenere e lapilli debolmente stratificati e da cenere e lapilli massivi o laminati debolmente cementati, con rare intercalazioni di conglomerati clasto-sostenuti massivi. il terzo terrazzo coincide con il sintema di caperroni ed affiora solo lungo la valle del torrente olivento, fino alla confluenza con il fiume ofanto. il limite inferiore del sintema corrisponde ad una superficie erosiva, che si sviluppa sotto l’attuale superficie deposizionale del torrente (fig. 5). la superficie pianeggiante individuata a tetto dell’unità, ed estesa fino alla località catena (fig. 4), corrisponde ad una superficie deposizionale posizionata circa 12 m sopra l’attuale fondovalle. il limite superiore del sintema è rappresentato dalla superficie erosiva in cui si è impostata la piana alluvionale attualmente in evoluzione. i depositi sono costituiti da ceneri, lapilli e ciottoli a prevalente composizione vulcanica, con stratificazione incrociata e piano parallela. in questa configurazione i depositi del sintema di s. angelo, legati alla fase di incisione della paleovalle del bv e le successioni epiclastiche del bv, sono stati raggruppati nel supersintema di monte vulture, mentre le unità terrazzate legate alla fase di reincisione dei depositi del bv sono raggruppati nel supersintema di monticchio (fig. 5). 4. sedimentologia dei depositi affioranti nel bacino di venosa analisi sedimentologiche di dettaglio (tessiture, strutture sedimentarie, natura degli elementi, paleocor278 fig. 7 limiti inconformi delle unità stratigrafiche distinte nel bacino di venosa: a) tra i sintemi di foggianello e barile e b) tra i sintemi di barile e melfi. unconformity bounded stratigraphic units of venosa basin: a) between barile and foggianello synthems and b) between melfi and barile synthems. p. giannandrea renti, contenuto macrofossilifero) realizzate su 21 log, hanno permesso di distinguere nel bv sedimenti di natura vulcanica, sia in f a c i e s epiclastica sia in f a c i e s primaria, riconducibili a tre principali ambienti deposizionali: i) piana braided ghiaiosa con intercalazione di prodotti vulcanici in f a c i e s primaria (pyroclastic flow e fall deposit), ii) piana b r a i d e d sabbiosa ad elevata sinuosità in evoluzione a paludi e/o laghi effimeri con intercalazione di prodotti vulcanici in f a c i e s p r i m a r i a (pyroclastic flow e fall deposit), iii) riempimento di canale alluvionale ad opera di flussi piroclastici e una sequenza eruttiva prossimale all’area sorgente. tra le facies epiclastiche sono state distinte, in relazione alle percentuali di frequenza di fango, cenere, lapilli, ciottoli e delle strutture interne, f a c i e s ghiaiose, con diverse percentuali di matrice sabbiosa; facies tufitiche, fangose, carbonatiche e depositi di alterazione (tab. 1). le f a c i e s vulcaniche, in netto subordine, si rinvengono intercalate a quelle epiclastiche e, quando sufficientemente estese lateralmente, rappresentano dei m a r k e r s stratigrafici. la gran parte dei prodotti vulcanici (tab. 2) sono costituiti da cenere da finissima a grossa e/o lapilli, meno frequenti sono i depositi grossolani, con bombe e blocchi. le facies epiclastiche e quelle vulcaniche sono riconducibili complessivamente a 6 associazioni di facies (a, b, c, d, e, f). le associazioni a, b, c e d sono prevalentemente epiclastiche, mentre le associazioni e ed f sono rappresentate da depositi vulcanici primari (tab. 3). le associazioni b, c e d sono in rapporto di eteropia di facies a tetto dell’associazione a. in particolare l’associazione b, affiorante solo a occidente del bv (fig. 6), passa verso oriente, lungo l’asse del bacino, all’associazione c che, invece, affiora in tutto il bacino. quest’ultima passa lateralmente e superiormente all’associazione d. 4.1 associazione di facies a: ghiaia e cenere massivi e subordinatamente stratificati, con depositi di flusso piroclastico descrizione. questa associazione affiora alla base della successione di depositi del bv con uno spessore massimo di 23 m nel settore nord-occidentale del bacino e minimo di 5 m nel settore sud-orientale (fig. 6). le f a c i e s che la compongono sono prevalentemente ghiaiose (fig. 8) sia massive (gcm, gm e gmm) che stratificate (gcp, gch). le f a c i e s massive gcm, gm e gmm sono in corpi a forma lenticolare intercalati ad 279 tab. 3 classificazione delle associazioni di facies e loro interpretazione ambientale. classification of the facies associations and environmental interpretation. associazione facies geometrie/ dimensione interpretazione interpretazione degli di facies dominanti strutture massima dei processi ambienti deposizionali sedimentarie clasti (cm) deposizionali a gcm, gm, corpi metrici 30-50 ciottoli debris-flow; sheet piana braided ghiaiosa, gcp, alh, lentiformi silicoclastici, flood; lahar; interessata da apporti alm, malm associati a 200-240 blocchi accrescimento laterale improvvisi di debris-flow superfici di tufitici, di barra ghiaiosa; e piroclastic flow canalizzazione. 7 pomici pyroclastic flow. b alh, alm, strati decimetrici 2 lapilli, sheet flood; piana braided prossimale ma, gbcm tabulari, con alla 6 ciottoli debris-flow; dominata da sheet flood, base esteso silicoclastici, fall deposit. interessata da apporti deposito metrico 160-350 blocchi improvvisi di depositi lentiforme. di lava gravitativi di materiale vulcanico caldo e di fall deposit. c alt, alh, strati tabulari 1-2 lapilli, migrazione di dune; piana braided ad elevata alm, mlc decimetrici, con 20 ciottoli sheet flood; sinuosità interessata da rare lenti vulcanici riempimento di docce apporti improvvisi di centimetriche di di erosione; lahar; fall deposit silt e superfici di fall deposit. canalizzazione metriche. d fsm, alm, alternanza di strati 1-3 lapilli decantazione con paludi e/o laghi effimeri, alt, mlc tabulari laminati debole trazione; interessati da apporti spessi da alcuni debris-flow; migrazione improvvisi di debris-flow centimetri a 1-2 m. di dune; riempimento e di fall deposit. di docce di erosione; fall deposit. e malm,. strati tabulari 1-2 pomici pyroclastic flow piccolo canale dominato metrici massivi. da apporti di pyroclastic flow. f mb, ma, strati decimetrici 4 lapilli, pyroclastic flow; sequenza eruttiva mlc. tabulari, con a 30 ciottoli fall deposit. prossimale all’area tetto un corpo calcarei, sorgente. lentiforme metrico. 7 ciottoli lavici evoluzione sedimentaria della successione alluvionale e lacustre ... altre f a c i e s; la superficie di base è erosiva. le tre f a c i e s sono costituite da ghiaia, di natura esclusivamente sedimentaria oppure con ciottoli di lave e/o di tufi clasto-sostenuta (gcm; fig. 8a) oppure matrice e fango-sostenuta (gm e gmm; fig. 8b; fig. 8c), priva di strutture interne. le dimensioni massime dei ciottoli raramente superano i 50 cm; quando sono presenti blocchi vulcanici ( lave oppure tufi) possono raggiungere anche il diametro di 1÷2,5 m. i ciottoli sedimentari sono rappresentati da: calcareniti, brecciole, arenarie, calcari marnosi, calcari con selce e diaspri, mentre quelli vulcanici da lave e da tufiti a composizione trachifonolitica. la forma dei ciottoli sedimentari varia notevolmente: sono frequenti ciottoli a forma tabulare, a lama e a bastoncino, mentre sono nettamente subordinati quel li equidimensionali; tra i ciottoli vulcanici , invece, la forma equidimensionale è la più frequente. anche la stima dell’arrotondamento varia notevolmente: i ciottoli sedimentari sono da molto arrotondati ad arrotondati, mentre quelli vulcanici sono generalmente da sub-angolosi a sub-arrotondati. il grado di selezionamento varia da scarso a moderato. la matrice è costituita da cenere da media a grossa, in cui si riconoscono abbondanti, cristalli millimetrici di pirosseno. lo spessore dei depositi può variare da 10÷20 cm a 4÷5 m. le facies stratificate sono meno frequenti e rappresentate da ghiaia clasto e matrice–sostenuta, a stratificazione obliqua (gcp; fig. 8d), con inclinazione di 30° e gradazione diretta lungo le superfici di stratificazione, oppure con debole stratificazione orizzontale (gch; fig. 8e), con o senza ciottoli embriciati. la matrice è generalmente una sabbia media e fine di colore scuro ricca di cristalli di pirosseno, e i ciottoli variabili in un range di 2÷50 cm, sono costituiti da calcareniti, arenarie, tufi, lave, siltiti, brecciole e calcari marnosi. anche per questa l i t o f a c i e s, come per le precedenti, la forma e il grado di arrotondamento dei ciottoli varia a seconda che si considerino ciottoli sedimentari, oppure vulcanici: i primi sono ben arrotondati, con forme tabulari, a lama e a bastoncino; i secondi sono sub-arrotondati ed equidimensionali. nella parte alta dell’associazione, intercalati ai conglomerati alluvionali, si distinguono depositi piroclastici di cenere massiva con lapilli centimetrici biancastri (malm; fig. 8) organizzati in banchi metrici. interpretazione. l’associazione di facies descritta consente di riferire l’ambiente deposizionale ad una piana alluvionale ghiaiosa, caratterizzata da canali braided incisi in una valle principale, interessata da apporti improvvisi di depositi gravitativi (debris flow) connessi a flussi inerziali, turbolenti (miall, 1996) e iperconcentrati (pierson, 1980; smith, 1986) di ghiaia e cenere e di prodotti vulcanici primari legati a sedimentazione in massa da flussi piroclastici (pyroclastic flow; sp a r k s, 1976). i flussi piroclastici sono associabili a eruzioni particolarmente intense e voluminose verificatesi nelle prime fasi di formazione del vicino vulcano di monte vulture, descritte come coltri ignimbritiche di fara d’olivo (crisci et al., 1983) e comprese nell’omonimo subsintema di fara d’olivo (giannandrea et al., 2006). 4.2. associazioni di facies b: cenere e lapilli a stratificazione piana orizzontale, con intercalazioni di depositi massivi e vulcanici di caduta descrizione. l’associazione di facies b, è costituita da una successione di strati decimetrici tabulari di cenere e lapilli a laminazione sottile piano parallela (alh; fig. 9d). i lapilli sono centimetrici e spesso si concentrano secondo piani sottili. in alternanza stratigrafica e in subordine rispetto alla prima sono le f a c i e s a l m , ma e mlc. queste sono rappresentate da cenere da media a grossa, massiva oppure a gradazione normale, con lapilli centimetrici dispersi omogeneamente negli strati oppure concentrati alla base di essi (alm; fig. 9c). a luoghi, si distinguono strati centimetrici di ceneri 280 fig. 8 foto delle facies ghiaiose: a) gcm, b) gm, c) gmm, d) gcp, e, gch. per la classificazione delle facies vedi tabella 1. view of the gravelly facies: a) gcm, b) gm, c) gmm, d) gcp, e, gch. for facies classification see table 1. p. giannandrea da fini a finissime, massive (ma; fig. 11e) oppure lapilli pomicei clasto-sostenuti massivi, con pomici biancastre dalle dimensioni di 0,5÷1 cm (mlc; fig. 11f). a diverse altezze stratigrafiche l’associazione comprende anche rare intercalazioni di ghiaia clasto e matricesostenuta, con debole stratificazione orizzontale (gch; fig. 8e), strati di cenere media con laminazione incrociata, piana e concava (ap e alt; fig. 9a e 9b) e sottili intercalazioni lentiformi di cenere fine e fango a laminazione sottile oppure massivi (fsm; 10c). alla base, l’associazione comprende blocchi di lava clasto-sostenuti (gbcm; fig. 11a) costituenti uno strato a forma piatta, con superficie di base erosiva e spessore massimo di circa 4 m. i blocchi, delle dimensioni massime di 3 m, sono sub-arrotondati e di forma prevalente equidimensionale. la composizione dei blocchi è in gran parte fonolitica, e soltanto, per alcuni ciottoli decimetrici, trachiandesitica con grossi fenocristalli di k-feldspato e di plagioclasio. alcuni grossi ciottoli mostrano deformazioni della geometria esterna nei punti di contatto con altri ciottoli e, quando sezionati, una fratturazione perpendicolare alla superficie esterna del ciottolo (fig. 11ab). la matrice, nettamente subordinata ai blocchi, è costituita da cenere da media a grossa, con, a luoghi calchi di rami e piccoli tronchi. interpretazione. la prevalenza della litofacies alh, connessa a un regime di flusso critico (sheet flood; mi a l l, 1996) con migrazione di dune molto piatte (jopling, 1967; smith, 1971; mcbride et al., 1975), e la composizione esclusivamente vulcanoclastica del detrito, consente di interpretare l’associazione b come una piana braided ad alta energia, alimentata da detrito vulcanico di cenere e lapilli, derivanti dal monte vulture. durante le fasi di attività del vulture, a seguito di eruzioni ad elevata magnitudo, la piana braided poteva essere anche sede di sedimentazione di piroclastiti di caduta (fall deposit) e di colate di cenere e lapilli (ash flow; lahar) provenienti dai fianchi della valle. il deposito massivo (gbcm) presente alla base dell’associazione è interpretabile come una colata di detrito vulcanico; la fratturazione interna e le deformazioni dei ciottoli sono indicativi di un rapido raffreddamento (forse in acqua) di blocchi lavici caldi. 4.3. associazioni di facies c: cenere e lapilli a stratificazione incrociata, con intercalazioni di depositi massivi e vulcanici di flusso piroclastico e di caduta d e s c r i z i o n e. l’associazione c è costituita prevalentemente da cenere media a stratificazione incrociata piana (ap; fig. 9a), con inclinazione variabile da 15° a 25°, e da cenere, media e grossa, e lapilli, organizzati in set di lamine, isolate o in gruppi, a formare corpi spessi anche 1÷2 m con base erosiva, a stratificazione incrociata concava (alt; 9b) e piano parallela (alh; fig. 9d). i lapilli possono essere rappresentati da litici e/o pomici, mentre la cenere è costituita sia da vetro sia da cristalli di pirosseno e biotite. a seconda del s o r t i n g d e l materiale preso in carico dalla corrente, il detrito vulcanico si dispone lungo set organizzati per classi granulometriche o per densità. le pomici spesso costituiscono concentrazioni centimetriche lenticolari, nella parte più depressa dei solchi erosivi. tra i lapilli sono dominanti le pomici (bianche e grigiastre molto vescicolate), di norma angolose e con diametro sino a 2÷3 cm. a diverse altezze stratigrafiche l’associazione c presenta rare intercalazioni di strati delle facies gcm, gch, alm, fsm, 281 fig. 9 foto delle facies tufitiche: a) ap, b) alt, c) alm, d) alh, e) ar. per la classificazione delle facies vedi tabella 1. view of the tufaceous facies: a) ap, b) alt, c) alm, d) alh, e) ar. for facies classification see table. 1. evoluzione sedimentaria della successione alluvionale e lacustre ... malm, iaaccr e mlc. nel settore sud-occidentale del bacino (fig. 4) sono frequenti ceneri, da medie a fini, massive, a struttura omogenea oppure simmetrica o complessa, con lapilli pomicei bianchi e/o grigi dal diametro variabile da alcuni millimetri a un centimetro (alm; fig. 9c). depositi decimetrici di lapilli pomicei di caduta (mlc; fig. 11f) sono di norma intercalati alle ceneri stratificate e raramente in quelle massive (t1-7 di fig. 6). i lapilli pomicei sono clasto-sostenuti, massivi, con pomici e subordinatamente litici delle dimensioni variabili in funzione del tipo di deposito da 0,5 cm a 4÷5 cm. le pomici hanno una colorazione variabile da bianca a grigio-verdastra e grigio scuro. in alcuni strati è possibile osservare una colorazione variabile, dalla base al tetto degli strati, da grigio chiaro a grigio scuro. la matrice è quasi del tutto assente; a luoghi sono presenti millimetrici cristalli di pirosseno. le facies ghiaiose massive (gcm; fig. 8a) e a stratificazione orizzontale (gch; fig. 8e) sono rappresentate da sottili intercalazioni presenti, a luoghi, solo nel settore orientale del bv (log bv2 e bv19 di fig. 6). la base dei depositi è sempre erosiva. interpretazione. la complessa sovrapposizione di barre di cenere e lapilli amalgamati, legati a regimi di flusso da critico a sub-critico, riempimento di docce di erosione e migrazione di dune (miall, 1996), sono indice di frequenti cicli di inondazione e alta variabilità laterale della sedimentazione, con moto della corrente molto più alta della velocità critica di erosione e alta disponibilità di sedimento da erodere in sito (rø e & he r m a n s e n, 1993). quest’ultimo era fornito dalle frequenti eruzioni del vulture, che proiettavano nel bacino elevate quantità di cenere e lapilli sotto forma di depositi di caduta (mlc) e di flusso piroclastico (malm). il fondovalle assumeva così l’aspetto di una piana b r a id e d con elevata sinuosità, con flussi permanenti nei canali maggiori e frequenti apporti di colate di cenere. 4.4. associazione di f a c i e s d: fanghi da massivi a laminati, con intercalazioni di depositi carbonatici, cenere massiva e lapilli massivi di caduta d e s c r i z i o n e. l’associazione d affiora in località piano regio e li scafoni-mattinella (fig. 4). le f a c i e s prevalenti sono quelle fangose massive oppure laminate. in relazione alla percentuale di materiale vulcanico contenuto, si distinguono due facies (fsm e almf; fig. 10b; fig. 10a). la prima è costituita da strati metrici di argilla e silt, caratterizzata da frequenti bioturbazioni prodotte da radici e gasteropodi polmonati. questi ultimi sono rappresentati da associazioni miste, sia terrestri sia di acque dolci (genere planorbis, geoffroy), indicative di un’alternanza di fasi di inondazione e di prosciugamento. la facies almf è costituita da cenere fine. alle f a c i e s fangose sono intercalati strati metrici di: i) cenere medio-fine massiva (alm; fig. 9c) e a laminazione incrociata da r i p p l e s (ar; fig. 9e), ii) ceneri e lapilli a stratificazione incrociata concava (alt; fig. 9b) e orizzontale (alh; fig. 9d), associati a depositi vulcanici di caduta di lapilli clasto-sostenuti, privi di matrice, massivi (mlc; fig. 11f), iii) strati decimetrici di calcari grigiochiari, massivi o con laminazione orizzontale (c; fig. 10c) e iiii) cenere da fine a finissima gradata (na; fig. 1 1 d ) . i n t e r p r e t a z i o n e. la prevalenza di f a c i e s f a n g o s e (fsm; almf) legate a processi di decantazione con debole trazione (mi a l l, 1996) e a flussi di tracimazione (o v e r b a n k) (mi a l l, 1996; wa l k e r 1967; va n ho u t e n, 1968; be s l e y & tu r n e r, 1983) o di piena calante (w a n i n g), è indicativa di un ambiente deposizionale di palude o di laghi effimeri, in cui si alternavano periodi di alluvionamento a periodi di siccità legati anche alle diverse fasi di attività vulcanica del vulture, che rappresentava l’area sorgente dei depositi di caduta (mlc). l’associazione dei depositi trattivi (alt e alh) e massivi (alm) a quelli di caduta fà ritenere che le ingenti precipitazioni, che generalmente seguivano le eruzioni vulcaniche, portavano alla formazione di: i) flussi idrici, da critici a sub-critici, che rielaboravano il detrito vulcanico appena sedimentato con riempimento di docce di erosione e migrazione di dune (mi a l l, 1996; jo p l i n g, 1967; sm i t h, 1971; 282 fig. 10 foto delle facies fangose: a) almf, b) fsm, c) c. per la classificazione delle facies vedi tabella 1. view of the muddy facies: . a) almf, b) fsm, c) c. for facies classification see table 1. p. giannandrea mcbr i d e et al., 1975), e ii) flussi turbolenti ad alta concentrazione da cui si aveva una rapida caduta di sedimento (sm i t h, 1986) nella fase di energia calante (dr e y e r, 1993). durante i periodi di assenza di attività vulcanica diminuiva notevolmente il trasporto solido e nelle aree depocentrali dei piccoli bacini lacustri prevaleva la precipitazione chimica di depositi calcarei (c). 4.5. associazione di f a c i e s e: cenere massiva, con lapilli pomicei d e s c r i z i o n e. l’associazione è composta da circa 8 m di prodotti vulcanici affioranti, lungo il margine meridionale del bv, dalla fiumara dell’arcidiaconata all’abitato di venosa (fig. 4). i sedimenti vulcanici sono strati di cenere color nocciola, a granulometria da media a fine, massiva, a struttura omogenea, con lapilli pomicei distribuiti in modo uniforme, o complessa, con lapilli pomicei concentrati in bande visibili a più livelli nello strato (malm; fig. 11b). le pomici sono di colore bianco e/o grigio e dal diametro variabile da alcuni millimetri a un centimetro. lo spessore degli strati varia da 5÷10 cm a circa 1,50 m. tra gli strati, a luoghi, si distinguono ceneri massive prive di strutture interne riconducibili alla facies alm (fig. 9c) i n t e r p r e t a z i o n e. l ’ a s s o c i a z i o n e di facies e costituisce una successione di prodotti vulcanici depositati sul versante meridionale del bv, tra la fiumara dell’arcidiaconata e l’abitato di venosa, e localmente nel paleo torrente la pelosa (rappresentato da un canale alluvionale stretto e ripido) ad opera prevalente di sedimentazione in massa da un flusso piroclastico concentrato, connessi all’attività vulcanica di monte vulture. in particolare, questi depositi, sia per i loro caratteri sedimentologici sia per la posizione stratigrafica, sono correlati con simili depositi di flussi piroclastici concentrati (ash flow) presenti al monte vulture nel la parte inferiore (associazione a) del subsintema di rionero ( gi a n n a n d r e a et al, 2006; fig. 2). 4.6. associazione di f a c i e s f : breccia, lapilli e cenere d e s c r i z i o n e. sequenza di depositi vulcanici, spessa 4 m ed estesa lateralmente alcune centinaia di metri, formata da tre f a c i e s sovrapposte affiorante sul margine meridionale del bv, in località “la starza” (fig. 4). le vulcaniti, nella successione di depositi alluvionali e lacustri, si individua alla base del sintema di barile su depositi epiclastici alluvionali derivanti dal disfacimento delle ignimbriti di fara d’olivo. la sequenza inizia con uno strato spesso 65 cm di lapilli massivi clasto-sostenuti (mlc; fig. 12a). i lapilli sono litici e pomici delle dimensioni variabili, per entrambi, fino ad un massimo di 5 cm. le pomici sono chiare alla base, nei primi 30 cm dello strato, e grigio scure al tetto. seguono 40 cm di cenere da grossa a fine e finissima in strati decimetrici massivi (ma; fig. 12a). la sequenza termina con uno strato spesso 3 m di breccia massiva omogenea clasto-sostenuta e ben cementata, con lapilli e blocchi sub-angolosi (mb; fig. 12b). la natura litologica del detrito è per il 90% vulcanica (lave grigio-scure e verdi, con una puntinatura rossastra, cumuliti di biotiti, grossi cristalli di pirosseno e pomici centimetriche), con diametro massimo di 7 cm. i blocchi sono delle dimensioni massime di 30 cm e costituiti esclusivamente da clasti sedimentari (calcareniti e brecce calcaree). la frazione fine e finissima è quasi del tutto assente con una 283 fig. 11 foto delle facies vulcaniche: a) gbcm, b) malm, c) aaccr, d) na, e) ma, f) mlc. per la classificazione delle facies vedi tabella 2. view of the volcanic facies: a) gbcm, b) malm, c) aaccr, d) na, e) ma, f) mlc . for facies classification see table 2.. evoluzione sedimentaria della successione alluvionale e lacustre ... discreta percentuale di piccoli vuoti. tale breccia affiorante per qualche centinaio di metri passa lateralmente, da località “la atarza” verso nord, a cenere grossolana massiva, con lapilli centimetrici e rari blocchi angolosi di calcareniti e calcari marnosi, del diametro di 7÷10 cm. i n t e r p r e t a z i o n e. il banco di breccia (mb) è riconducibile ad un processo di sedimentazione in massa di un flusso piroclastico concentrato, mentre gli strati di lapilli (mlc) e di cenere (ma) massivi sono depositi di caduta (fall deposits). inoltre, anche se al momento non sono disponibili dati di carattere geochimico e petrografico, poiché i depositi di caduta chiari alla base e scuri a tetto, in aree prossimali al vulture, sono dello spessore di 30÷40 cm e le pomici sono del diametro massime di 2÷3 cm, mentre il deposito osservato in località “la starza” (distante circa 8 km dal vulture) ha uno spessore di 65 cm e lapilli litici che raggiungono il diametro di 5 cm, e date le ridotte estensioni laterali dei depositi e la presenza di un banco di breccia massiva di esplosione (mb), si può escludere la provenienza dal monte vulture ed attribuire questi depositi ad una sequenza eruttiva prossima all’area sorgente. il centro eruttivo è verosimilmente sepolto sotto i depositi dei sintemi di barile e di melfi sul margine meridionale del bv in località “la starza” (fig. 4). i clasti sedimentari osservati nella f a c i e s mb derivano da una formazione miocenica (formazione di faeto), caratterizzata da f a c i e s torbiditiche a composizione carbonatica, che affiora nelle vicinanze del probabile centro eruttivo e in profondità sotto le unità plio-pleistoceniche della fossa bradanica (balduzzi et al., 1982). 5 elementi tettono-stratigrafici il rilevamento geologico di dettaglio, eseguito sia sui depositi mediopleistocenici del bv sia sul substrato sedimentario, ha evidenziato che il bv più che essere condizionato da strutture antiappenniniche (piccarreta & ri c c h e t t i, 1970; se g r e, 1978; bo e n z i et al., 1987; ciaranfi et al., 1983), di cui non si trova traccia, sembra impostato su un complesso di faglie distensive orientate in direzione n110°±5°, n130° e est-ovest. le geometrie espresse dalle strutture tettoniche, tipiche di aree interessate da tettonica trascorrente, indicherebbero per queste strutture un movimento di tipo transtensivo. solo il margine nord-occidentale del bv è delimitato da una faglia antiappenninica coincidente con la linea del vulture di sc h i a t t a r e l l a et al. (2005). in particolare le strutture tettoniche rappresentate individuano due aree subsidenti (località piano regio e li scafoni mattinella) associate a strutture tettoniche distensive; solo lungo il margine meridionale del bv, nel tratto compreso tra il torrente la pelosa e la fiumara dell’arcidiaconata, viene tracciata sotto i depositi del bv una struttura tettonica inversa che delimita i terreni della catena da quelli della fossa bradanica. le strutture tettoniche distensive mostrano segni di attività dal colmamento della fossa bradanica fino alla sedimentazione dei primi metri dei depositi del sintema di barile. evidenze di questa asserzione sono: i) il ritrovamento sotto i depositi del bv di conglomerati deformati della formazione dei conglomerati di irsina, ii) la presenza di una superficie di erosione che fossilizza strutture tettoniche al limite tra il sintema di foggianello e quello di barile (fig. 13) e di discontinuità minori nell’ambito dei depositi del sintema di barile e iii) la presenza di ristrette aree subsidenti sovraimposte ad un’area in sollevamento tettonico regionale. la fase deposizionale legata al successivo sintema di melfi realizza un esteso ripiano, visibile attualmente a tetto dei depositi del bv (fig. 5). le faglie sub-verticali, orientate in direzione n90°±5° e n103°±2°, che individuano il piccolo graben visibile sul margine nord-occidentale del bv in località “le mangiatoie” (fig. 4), ritagliano la successione del bv determinando il ribassamento del tetto del supersintema di monte vulture di circa 75 m (fig. 5; fig. 14a). in questa area si rilevano depositi stratificati del sintema di barile, deformati e molto fratturati (fig. 14b), al di sotto di depositi alluvionali terrazzati del successivo sintema del torrente olivento che fossilizzano le strutture tettoniche. 284 fig. 12 sequenza eruttiva correlata ad un centro sepolto posizionato in località “la starza” composta, dalla base, da a) lapilli chiaro-scuri di caduta (mlc) a cui seguono ceneri di caduta (ma) e b) una breccia massiva (mb). eruptive sequence correlated with buried volcanic centre located in “la starza” locality, from the base: a) fall deposits of dark-clear lapilli (mlc,) ash fall (ma) and b) massive breccias (mb). p. giannandrea 285 fig. 13 rapporti stratigrafici tra i sintemi di foggianello e barile. la superficie erosiva che separa le due unità fossilizza anche una faglia ad apparente componente diretta che ritaglia i soli depositi del sintema di foggianello. stratigraphic relationships between barile and foggianello synthems. the erosive surface at the top of foggianello synthem fossilizes a fault too. fig. 14 strati deformati della successione del bacino di venosa: a) panoramica di località “le mangiatoie” dove è visibile una successione di strati del sintema di barile inclinati di circa 60°, con a tetto il terrazzo del subsintema li scafoni (tol2); b) particolare degli strati deformati. deformed layers of venosa basin succession: a) view of “le mangiatoie” locality were can be seen deformed succession of the barile synthem (dip 60°), with li scafoni subsynthem (tol2) terrace at the top of deformed layers; b) detail of the deformed layers. evoluzione sedimentaria della successione alluvionale e lacustre ... 286 6 evoluzione paleogeografica le ricerche eseguite nelle valli della fiumara di venosa e del torrente olivento hanno permesso di riconoscere tre fasi principali dell’evoluzione paleogeografica dell’area occupata dal bv dal pleistocene medio al pleistocene superiore. prima fase (fig. 15a) la prima fase è legata alla formazione del sintema di s. angelo, composto da terrazzi alluvionali formati prima della sedimentazione dei depositi del bv sul substrato sedimentario. questa unità comprende fasi erosive e depositi terrazzati, che denunciano un’inversione di tendenza dell’attività dell’area da subsidente ad area in sollevamento. si configura un iniziale esteso ripiano, costituito dalla superficie deposizionale del conglomerato del sintema di palazzo san gervasio, interessato da due blandi disturbi tettonici, uno ad andamento appenninico e l’altro antiappenninico. queste strutture tettoniche corrispondono ad una faglia tracciata lungo il torrente olivento, che coincide con la linea del vulture (schiattarella et al., 2005) e ad una struttura distensiva, che dall’appennino si sviluppa in avanfossa inizialmente con direzione est-ovest, successivamente con direzione n110°±5°, n130°. la paleovalle del bv iniziò a svilupparsi, all’inizio del pleistocene medio, a nord-est degli abitati di venosa e palazzo san gervasio, con deflusso delle acque in direzione sud-est. il tratto di bacino del fiume ofanto, compreso nell’area studiata, rappresenta l’evoluzione di un segmento del versante destro della paleovalle. lo sviluppo dell’azione erosiva dei corsi d’acqua impostati su strutture tettoniche determinò la formazione di valli alluvionali, ad andamento rettilineo e fianchi verticali, incassate nei depositi di avanfossa per un’altezza di circa 130 m (fig. 5). il reticolo idrografico della paleofiumara di venosa si sviluppò, con un processo di erosione regressiva e sovrimposizione, nei depositi di avanfossa, fino alla linea del vulture e da qui in direzione ovest sulle coltri appenniniche. seconda fase (fig. 15b, c e d) la seconda fase è caratterizzata dalla sedimentazione dei depositi del bv e del più esteso terrazzo del fiume ofanto, raggruppati nei sintemi di foggianello, barile e melfi. il sintema di foggianello comprende ghiaie alluvionali sedimentate in un’ampia piana braided. sul versante meridionale di tale piana, molto probabilmente, si svilupparono ampi conoidi alluvionali in corrispondenza dei maggiori paleo-affluenti (coincidenti con il torrente la pelosa e il vallone del reale; fig. 15b). gli apporti idrici nel bv defluivano da ovest verso est (fig. 16). in fig. 15 schemi paleogeografici dell’area dei bacini idrografici della fiumara di venosa e del torrente olivento: a) morfologia prebacino di venosa; b, c, d) ambienti deposizionali, suddivisi per sintemi, dei depositi del bacino di venosa. palaeogeographic schemes of the hydrographical basins area of venosa river and olivento stream: a) pre-sedimentary venosa basin succession; b, c, d) depositional environment of the venosa basin deposits. p. giannandrea questa fase alluvionale si registra anche l’inizio dell’attività vulcanica al monte vulture, evidenziata da detrito vulcanico nella matrice dei conglomerati e da rari ciottoli lavici a composizione trachiandesitica. il detrito vulcanico diventò dominante con le voluminose eruzioni delle coltri ignimbritiche di fara d’olivo. le vulcaniti si accumularono in spesse successioni lungo il margine occidentale del bv e con volumi minori lungo la valle del paleotorrente la pelosa (fig. 4). nel bacino del fiume ofanto, in questa prima fase deposizionale, iniziò a formarsi in corrispondenza della linea del vulture la paleovalle del torrente olivento, che alla confluenza con il paleoalveo del fiume ofanto formava una piccola conoide alluvionale (fig. 15b). la successiva fase deposizionale, legata al sintema di barile (fig. 15c) seguì alla riattivazione delle strutture tettoniche, su cui si era impostata originariamente la paleovalle. inoltre, si attivarono anche alcuni tratti di faglie coniugate, che racchiudevano due ristrette aree in subsidenza tettonica, con drenaggio di tipo centripeto (fig. 16). questi ultimi costituivano due piccoli bacini endoreici, con depocentri sedimentari localizzati nelle località di piano di regio e li scafoni mattinella. il sollevamento tettonico dei margini del bv determinò la formazione di una evidente superficie erosiva, sia nel bv che nella paleovalle del fiume ofanto. questa fu anche una fase caratterizzata da grandi apporti vulcanici di depositi piroclastici di caduta e di flusso rielaborati in alveo da correnti idriche, spesso catastrofiche, subito dopo la loro deposizione. infatti vennero eruttati gli ingenti volumi di magmi (compresi nei subsintemi di rionero, vulture san michele e ventaruolo; fig. 2), che complessivamente costituiscono l’attuale apparato vulcanico centrale di monte vulture (giannandrea et al., 2006). eruzioni minori si verificarono anche nel bv, da un centro eruttivo ubicabi le approssimativamente lungo il suo versante meridionale, su una faglia orientata in direzione est-ovest (fig. 15b). nel bacino si instaurarono ampie aree sovralluvionate, tipo paludi o laghi effimeri, connesse a canali ad e levata sinuosità. contemporaneamente nel vicino bacino del fiume ofanto si sviluppò ulteriormente la paleovalle del torrente ol ivento, nel la quale si insediò un grande apparato conoidale, costituito in gran parte da ghiaia derivante dall’erosione della formazione di irsina e in minore percentuale da depositi epiclastici derivanti dalla rielaborazione delle piroclastiti, cadute direttamente in alveo. con la fase deposizionale del sintema di melfi, si ebbe infine una forte riduzione dei tassi di sedimentazione, con sviluppo di estesi depositi di travertino associati a sedimenti colluviali e, a luoghi, lacustri (fig. 15. d). terza fase (fig. 17) la terza fase (supersintema di monticchio) inizia con la reincisione dei depositi del supersintema di monte vulture, legata alla formazione sul margine nordoccidentale del bv di una piccola depressione tettonica (fig. 15d) e allo sviluppo del reticolo idrografico del torrente olivento. inizialmente la fase di modellamento portò all’erosione del rilievo che divideva il bv dal bacino del fiume ofanto, determinando la cattura delle acque defluenti dal monte vulture (fig. 17a) e la formazione sul versante destro della valle, in corrispondenza della faglia di località le mangiatoie (fig. 4), di un piccolo torrente ad andamento rettilineo ed elevato gradiente topografico. l’evoluzione successiva del reticolo idrografico del torrente olivento prevede la cattura delle acque del piccolo bacino del subsintema di toppo di maggio e la conseguente formazione della valle della fiumara di venosa (fig. 17b). nella fase erosiva la base del torrente olivento si attestò ad una quota inferiore a quella dell’attuale fondovalle. con la formazione del sintema di caperroni, infine, si realizzò una nuova fase sedimentaria, che si concluse con la genesi del ripiano osservabile a tetto dell’unità, circa 12 m sopra l’attuale fondovalle (fig. 4; fig. 5). 7 conclusioni le complesse relazioni stratigrafiche e sedimentologiche ricostruite per i depositi alluvionali e lacustri terrazzati affioranti nel bacino idrografico della fiumara di venosa hanno consentito di definire le relazione tra apporti vulcanici, tettonica, fasi erosionali e fasi deposizionali avvicendatesi nell’area dal pleistocene medio al pleistocene superiore. i risultati sono stati schematizzati in vari modelli evolutivi bidimensionali. il sollevamento 287 fig. 16 carta delle paleocorrenti dei depositi dei sintemi di foggianello e barile; mostra la dispersione degli apporti, di tipo centripeto, con punti di confluenza nelle località piano regio e li scafoni-mattinella e asse di deflusso principale parallelo all’asse del bv. palaeocurrent map of the barile and foggianello synthem deposits; it shows the palaeoflow direction, with confluence point in the piano regio and li scafoni-mattinella locality. evoluzione sedimentaria della successione alluvionale e lacustre ... regionale dell’area, la formazione di strutture tettoniche locali e l’attività eruttiva del vulcano di monte vulture, hanno giocato un ruolo fondamentale nel controllo della sedimentazione dei depositi epiclastici del bv e nella formazione di discontinuità utili per una suddivisione stratigrafica a limiti inconformi (ubsu). il quadro stratigrafico così delineato permette di collocare la successione epiclastica del bv, sedimentata in circa 150 ka, tra due fasi erosionali e di correlarla ai prodotti vulcanici emessi al vulture nella fase di formazione dei sintemi di foggianello, barile e melfi. le aree di accumulo dei depositi del bv sono impostate su faglie dirette a componente trascorrente e movimento sin-sedimentario, che hanno determinato, in un contesto generale di sollevamento, la formazione di ristrette aree a differente velocità di subsidenza in cui variavano sia i tassi di sedimentazione (da 0,23 a circa 0,53 mm/anno) sia i caratteri deposizionali delle facies. queste ultime infatti mostrano variazioni dal basso verso l’alto da ghiaiose a tufitiche. anche l’ambiente deposizionale varia da una piana braided ghiaiosa, interessata da apporti improvvisi di debris-flow e piroclastic flow, a paludi o laghi effimeri connessi a canali ad alta sinuosità soggetti ad apporti improvvisi d i d e b r i s f l o w e fal l deposit . l’evoluzione paleogeografica prospettata, relazionata attraverso le ubsu con l’evoluzione paleogeografica già proposta in gi a n n a n d r e a et al. (2006) per il monte vulture, consente di associare le tappe fondamentali dell’evoluzione paleogeografica e tettonica del margine appenninico della fossa bradanica a quella del settore esterno della catena sud appenninica e di scandire le età di formazione. bibliografia az z a r o l i a., pe r n o u. & ra d i n a b. (1968a) note illustrative della carta geologica d’italia: f° 188 “gravina di puglia”. serv. geol. d’it., 57 pp. az z a r o l i a., ra d i n a b., ri c c h e t t i g. & va l d u g a a. (1968b) note illustrative della carta geologica d’italia: f° 189 “altamura”. serv. geol. d’it., 2 2 pp. ba l d u z z i a, ca s n e d i r., cr e s c e n t i u., mo s t a r d i n i f. & tonna m. (1982) il plio-pleistocene del sottosuolo del bacino lucano (avanfossa appenninica). geologica rom., 21, 89-111. besley b.m. & turner p., (1983) origin of red beds in a moist tropical climate (eturia formation, upper carboniferous, uk) . in residual deposits: fig. 17 schemi paleogeografici relativi ai subsintemi di toppo di maggio e li scafoni. palaeogeographic schemes of the toppo di maggio and li scafoni subsynthem. 288 p. giannandrea 289 surfaces related weathering processes and material (ed. by r. c. l. wilson), spec. publ. geol. soc., london, 11, 131-147. boenzi f., la volpe l. & rapisardi l. (1987) evoluzione geomorfologica del complesso vulcanico del monte vulture (basilicata). boll soc geol it, 1 0 6, 673-682. bo e n z i f., pa l m e n t o l a g. & va l d u g a a . (1971a) n o t e illustrative della carta geologica d’italia: f° 200 “tricarico”. serv. geol. d’it., 46 pp. boenzi f., radina b., ricchetti g. & valduga a. (1971b) note illustrative della carta geologica d’italia: f° 201 “matera”. serv. geol. d’it., 48 pp. bo n a d o n n a f.p., br o c c h i n i d., la u r e n z i m.a., pr i n c i p e c. & ferrara g. (1998) stratigraphical and chronological correlations between monte vulture volcanics and sedimentary deposits of the venosa basin. quaternary international, 47, 87-96. bu e t t n e r a., pr i n c i p e c., vi l l a i.m. & br o c c h i n i d . (2006) geocronologia 39ar-40ar del monte vulture. in: c. principe (a cura di) “la geologia del monte vulture”. grafiche finiguerra – lavello, 7386. cagnazzi l., (1807) congetture su di un antico sbocco adriatico per la daunia fino al seno tarantino mem. di mat. e fis. della soc. it. sc., 13, modena. ca s e r o p., ro u r e f., en d i g n o u x l., mo r e t t i i., mü l l e r c., sage l. & vially r.(1988) neogene geodynamic evolution of the southern apennines. mem. soc. geol. it., 41, 109-120. ca s e r o p., ro u r e f., en d i g n o u x l., mo r e t t i i., mu l l e r c., sa g e l., & vi a l l y r . (1992) n e o g e n e geodynamic evolution of the southern apennines. mem. soc.geol. it. 41, 109-120. ca s n e d i r . (1988) la fossa bradanica: origine, sedimentazione e migrazione. mem. soc. geol. it., 41, 439-448. casnedi r., crescenti u. & tonna m. (1982) evoluzione dell’avanfossa adriatica meridionale nel pliopleistocene sulla base di dati di sottosuolo. mem. soc. geol. it. 24, 243-260. ciaranfi n., ghisetti f., guida m., iaccarino g., lambiase s., pi e r i p., ra p i s a r d i l., ri c c h e t t i g., to r r e m . , tortorici m. & vezzani l. (1983) carta neotettonica dell’italia meridionale. prog. fin. geod. del c.n.r., pubbl. n° 515, 62. cocco e., cravero e., ortolani f., pescatore t., russo m., sg r o s s o i., & to r r e m. (1972) les faciès sedimentaires miocènes du bassin irpinien (italie meridionale). atti acc. pont., nuova serie, 21, 113. crisci g., de fino m., la volpe l. & rapisardi l. (1983) pleistocene ignimbrites of monte vulture (basilicata, southern italy). n. jb. geol. paläont. mh, 12, 731-746. d ’ ar g e n i o b., pe s c a t o r e t. & sc a n d o n e p. (1973) schema geologico dell’appennino meridionale (campania e lucania). acc. naz. lincei, quad., 183, 49-72. de fino m., la volpe l. & piccarreta g. (1982) magma evolution at mount vulture (southern italy). b u l l . volcanol., 45, 115-126. de lo r e n z o g . ( 1 9 0 0 ) studio geologico del monte vulture. atti r acc sc fis mat napoli, 1 0, serie 2a,.207 pp. doglioni c., tropeano m. mongelli f. & pieri p. (1996) middle-late pleistocene uplift of puglia: an “anomaly” in the apenninic foreland. mem. soc. geol. it. 51, 101-117. dr e y e r t. (1993) quantified fluvial architecture in ephemeral stream deposits of the esplugafreda formation (paleocene), tremp-graus basin, northern spain. in: alluvial sedimentation (ed. by m. marzo and c. puigdefabregas), spec. publs int. ass. sedim.,17, 337-362 finetti i., lentini f., carbone s. catalano & del ben a., (1996) il sistema appenninico meridionale – arco calabro – sicilia nel mediterraneo centrale:studio geologico-geofisico. boll. soc. geol. it., 115, 529559 gi a n n a n d r e a p. (2004) i depositi terrazzati affioranti nell’alta valle del fiume ofanto (foglio n. 451 “melfi”, appennino campano-lucano) . i l quaternario, 17, (2/2), 511-521. gi a n n a n d r e a p. (2006a) il bacino fluvio-lacustre di venosa. in: c. principe (a cura di) “la geologia del monte vulture”. grafiche finiguerra – lavello, 5572. giannandrea p. (2006b) carta geologica del bacino di venosa. in: c. principe (a cura di) “la geologia del monte vulture”. grafiche finiguerra – lavello. giannandrea p., la volpe l., principe c. & schiattarella m. (2004) carta geologica del monte vulture alla scala 1:25.000. lac, firenze. giannandrea p., la volpe l., principe c. & schiattarella m. (2006) unità stratigrafiche a limiti inconformi e storia evolutiva del vulcano medio-pleistocenico di monte vulture (appennino meridionale, italia). boll. soc. geol. it.,125, 67-92. hippolyte j.c., angelier j., roure f. & casero p. (1994) piggyback basin development and thrust belt evoution: structural and palaeostress analyses of plio-quaternary basins in the southern apennines. journ. struct.geol., 16, 159-173. jopling a.v., (1967) origin of laminae deposited by the movement of ripples along a streambed: a laboratory study. j. geol., 75, 287-305 lentini f., carbone s., catalano s. & monaco c., (1990) tettonica a thrust neogenica nella catena appenninica-maghrebide: esempi dalla lucania e dalla sicilia. studi geologici camerti, volume speciale, 19-26. lentini f., catalano s. & carbone s. (1996) the external thrust system in southern italy: a target for petroleum exploration. petroleum geosci., 2 333342. mcbr i d e e.f., sh e p h e r d r.g. & cr a w l e y r . a. (1975) origin of parallel laminae by migration of bed form in a small flume. j. sedim. petrol., 45, 132-139. mi a l l a . d. (1992) alluvial deposits. in: walker r.g.& james m.p. (eds): facies models: response to sea-level change. geological association of canada, 119-142. mi a l l a.d. (1996) the geology of fluvial deposits. springer verlag, 502 pp. mo s t a r d i n i f. & me r l i n i s . (1986) appennino centro meridionale. sezioni geologiche e proposta di modello strutturale. mem. soc. geol. it., 35, 177202. or t o l a n i f., pa g l i u c a s., pe p e e., sc h i a t t a r e l l a m. & evoluzione sedimentaria della successione alluvionale e lacustre ... to c c a c e l i r . m . (1992) active tectonics in the southern apennines: relationships between cover geometries and basement structure. a hypothesis for a geodynamic model. igcp nº 276, newsletter, 5, 413419. pa t a c c a e. & sc a n d o n e p . (1989) p o s t t o r t o n i a n mountain building in the apennines. the role of the passive sinking of a relic lithospheric slab. in: boriani a., bonafede m., piccardo g.b. & vai g.b. (a cura di) “the lithosphere in italy”. atti conv. acc. naz. dei lincei, 80, 157176. patacca e. & scandone p. (2001) late thrust propagation and sedimentary response in the thrust-beltforepeep system of the southern apennines ( p l i o c e n e p l e i s t o c e n e ) . in: g.b. vai & i.p. martini (eds.): “anatomy of an orogen: the apennines and adjacent mediterranean basins”. kluwer academic publishers, 401-440. pa t a c c a e., sa r t o r i r., & sc a n d o n e p.(1990) tyrrhenian basin and apenninic arc: kinematic relations since late tortonian times. mem. soc. geol. it., 45, 425-451. pescatore t. & ortolani f. (1973) schema tettonico dell’appennino campano-lucano. boll. soc. geol. it., 92, 453-472. pe s c a t o r e t. (1978) evoluzione tettonica del bacino irpino (italia meridionale) durante il miocene. boll. soc. geol. it., 97, 783-805. pe s c a t o r e t., re n d a p., sc h i a t t a r e l l a m. & tr a m u t o l i m . (1999) stratigraphic and structural relationships between meso-cenozoic lagonegro basin and coeval carbonate platforms in southern apennines, italy. tectonophysics, 315, 269-286. piccarreta g. & ricchetti g. (1970) i depositi del bacino fluvio-lacustre del la fiumara di venosamattinelle e del torrente basentello. mem. soc. geol. it., 9, 121-134. pi e r i p., sa b a t o l. & tr o p e a n o m. (1994) e v o l u z i o n e tettonico-sedimentaria della fossa bradanica a sud del’ofanto nel pleistocene. in guida alle escursioni del 77°congresso nazionale della s.g.i., quad.bib. prov.matera, 15, 35-54. pi e r i p., sa b a t o l. & tr o p e a n o m . (1996) s i g n i f i c a t o geodinamico dei caratteri deposizionali e strutturali della fossa bradanica nel pleistocene. mem. soc. geol. it., 51, 501-515. pierson t.c. (1980) erosion and deposition by debris flows at mt. thomas. north canterbury, new zealand. earth surf. proc., 5, 227-247. pi p e r n o m. [a cura di], (1999) notarchirico – un sito del pleistocene medio iniziale nel bacino di venosa. edizione osanna. principe c. & giannandrea p. (2008) ubsu e cartografia geologica: problemi e potenzialità dell’utilizzo delle ubsu per l’interpretazione e la rappresentazione cartografica dei depositi quaternari vulcanici. l’esempio dei fogli n.451 “melfi” e n. 452 “rionero in vulture”. il quaternario, 21(1a), 61-68. pr o s s e r g., sc h i a t t a r e l l a m., tr a m u t o l i m., do g l i o n i c., harabaglia p. & bigozzi a. (1996) una sezione rappresentativa dell’appennino meridionale. riassunti conferenza sulla ricerca scientifica in basilicata, università della basilicata regione basilicata, febbraio 1996. raynal j.p., lefèvre d., vernet g., pilleyre t., sanzelle s., fa i n j., mi a l l i e r d. & mo n t r e t m . (1998) sedimentary dynamics and tecto-volcanism in the venosa basin (basilicata, italia) . quaternary international, 47-48, 97-105. ri c c h e t t i g . (1965) alcune osservazioni sulla serie della fossa bradanica. le “calcareniti di m. castiglione”. boll. socc. nat. in napoli, 74, 3-11. ricchetti g. (1967) lineamenti geologici e morfologici della media valle del fiume bradano. boll. socc. geol. it., 49, 421-622. røe s. l. & hermansen m. (1993) processes and products of large, late precambrian sandy rivers in northern norway. spec. publs. int. ass. sediment., 17, 151-166. sabato l., tropeano m. & pieri p. (2004) problemi di cartografia geologica relativa ai depositi quaternari del f° 471 “irsina”. il conglomerato di irsina : mito o realtà. il quaternario, 17(2/1), 391-404. sacchi a. & palmieri l. (1852) della regione vulcanica del monte vulture e del terremoto ivi avvenuto n e l l ’ a g o s t o 1 8 5 1. mem. acc. sc. fis. e mat., napoli. scandone p. (1972) studi di geologia lucana: carta dei terreni della serie calcareo-silico-marnosa e note i l l u s t r a t i v e . boll. soc. natur. in napoli, 8 1, 225300. sc h i a t t a r e l l a m., be n e d u c e p., di le o p., gi a n o s . i . , gi a n n a n d r e a p. & pr i n c i p e c. (2005) a s s e t t o strutturale ed evoluzione morfotettonica quaternaria del vulcano del monte vulture (appennino lucano). boll. soc. geol. it., 124, 543-562. segre a. g. (1978) il pleistocene ed il paleolitico della b a s i l i c a t a. atti xx riun. scient. ist. it. preist. protost.,15-39. selli r. (1962) il paleogene nel quadro della geologia dell’italia meridionale. mem. soc. it., 3, roma. smith g.a. (1986) coarse-grained nonmarine volcaniclastic sediment: terminology and depositional process. bull. soc. am., 97, 1-10. sm i t h n.d. (1971) pseudo-planar stratification produced by very amplitude sand waves. j. sedim. petrol., 41, 69-73. va l d u g a a. (1973) fossa bradanica. in: geologia dell’italia. a cura di a. desio, ed. utet, 692-695. van houten f.b. (1968) iron oxides in red beds. bull. geol. soc. am., 79, 917-920 walker t.r. (1967) color of recent sediments in tropical mexico: a contribution to the origin of red beds. bull. geol. soc. am., 78, 917-920 290 ms. ricevuto il 19 novembre 2008 testo definitivo ricevuto il 28 aprile 2009 ms. received: november 19, 2008 final text received: april 28, 2009 p. giannandrea microsoft word 04_forno_lm05.doc available online http:/amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 25 (2), 2012, 125-140 geological context of the becca france historical landslide (aosta valley, nw italy) maria gabriella forno1, marco gattiglio1 & franco gianotti1 1dipartimento di scienze della terra, università degli studi di torino, italy corresponding author: m.g. forno <gabriella.forno@unito.it> abstract: the wide historical becca france landslide occurred at dawn on july 6th, 1564. it involved the becca france ridge (2313 m a.s.l.) a few kilometers nw of the town of aosta (aosta valley, nw italy). this event buried the clusellaz valley floor (a dora baltea left tributary) destroying the populous ancient village of thora and resulting in an unknown number of victims (120-545). the occurrence of this landslide is documented in the local historical literature. despite this, the geological and morphological features of the accumulation have never been investigated. the aim of this work is to map the geological context of the area affected by the gravitational event, to reconstruct the phenomenon and to make a first evaluation of the causes of the landslide. the examined area is located along the contact between the middle penninic and the piedmont zone. the geological survey has allowed to distinguish, above the tectonically deeper continental unit (gran san bernardo nappe system), two oceanic units (lower and upper tmu of the aouilletta unit). this area was largely interested by the pleistocene glaciers and by a wide deep-seated gravitational slope deformation (p. leysser dsgsd). the detachment niche extends in the right side of the clusellaz valley and is shaped in the e slope of the becca france ridge. it corresponds to a very steep cirque-like scarp, very remarkable for its width (about 850 m), height (more than 500 m) and the lack of vegetation cover. it consists of two calcschist units (the lower one with prasinite) separated by a tectonic contact underlain by cargneule and gypsum. the niche cuts the doubled becca france ridges and other gravitational evidence of the p. leysser dsgsd. the landslide accumulation, some tens of meters thick, also exhibits a wide extent (about 1.26 km2). it climbed for about 80 m on the opposite side of the valley. the landslide body partially developed immediately below the detachment niche (proximal sector) is probably connected to a rockfall. most of the accumulation is lengthened for approximately 3 km into the clusellaz valley floor (middle-distal sector), showing several longitudinal ridges, up to ten meters high and some hundreds meters long. this sector, having travelled down the slope a long distance, is an example of a landslide body with longitudinal ridges, linked to a rock avalanche. the slope failure was triggered by the concurrence of various predisposing causes: i) the sufficiently strong relief energy, with difference of level of 700 m between the mountain crest and the glacially-deepened valley floor; ii) the fractured and slackened bedrock connected to the dsgsd; iii) the poor geomechanical properties of the outcropping calcschist; iv) the chemical dissolution of cargneule and gypsum along the tectonic contact between the two calcschist units. an interval of extremely heavy rainfall, that produced an increase in interstitial pressure, was probably the triggering cause. keywords: rock avalanche, dsgsd, aosta valley, becca france. 1. introduction the becca france historical landslide is known in the aosta valley local literature as the worst natural disa‐ ster causing victims of the region. it developed in the tributary clusellaz valley, a few kilometers nw of the town of aosta (fig. 1). nevertheless, the geological features of the landslide body (distribution, thickness, morphology and petrographic composition) and of the detachment niche (extent, morphology, gradient, lithology and fracturing) have never been investigated and described in detail. the geological context of the area involved in the event has now been studied. it includes a geological mapping of the becca france sector (see fig. 6) and a first evaluation of the landslide’s predisposing causes. the link with the pointe leysser deep-seated gravitational slope deformation (p. leysser dsgsd), a very extensive gravitational phenomenon, is particularly investigated. the local historical literature has described the wide landslide that occurred at dawn on july 6th, 1564, as coming from the eastern slope of the becca france ridge (cerutti et al., 1993). the landslide accumulation quickly buried the ancient village of thora, described as a nice place located in the clusellaz valley floor. currently, a new village (named thouraz) occurs 1 km se from the possible location of the ancient village. this ancient village was very important for its residential population (52 families) and its commercial activities (10 watermills and 14 weaving factories) (fénoil, 1883), although the accuracy of these data is disputed (caniggia et al., 1999). the first remarks about the disaster occur in some administrative acts (dated to 1565, 1576, 1581 and 1583), reporting a different number of victims (545 according to the inhabitants and 120 according to the authorities). these acts include a request for compensation for the victims and the landslide damage (loss of wood, vines and the ville-sursarre irrigation canal) (references in bollati, 1988). an old memorial plaque preserved in the parish church of sarre, containing the landslide date, is mentioned in caniggia et al. (1999). fénoil (1883) also relates a catastrophic flood in the t. clusellaz during the 1566. on june 10th, 1851 another significant alluvial event ravaged the sarre parish house garden on the clusellaz fan (caniggia et al., 1999). forno m.g. et al. 126 2. methods a detailed geological survey and photo interpretation have been performed for the becca france area, mapping the bedrock, the quaternary cover and the morphological features. the geological succession was first mapped at a scale of 1:5000 and then simplified in schematic form (see fig. 6). the tectono-stratigraphic units of the bedrock are based on their lithostratigraphic features and on lithological correlations with other units outcropping in the western alps. in the field, the regional foliation, i.e. the most pervasive metamorphic surface in the rocks (s1), has been considered for the structural reconstruction. this surface is sub-parallel to the lithological layering and represents a composite foliation generated by the transposition of an older and locally still recognizable metamorphic surface. fracture systems and fault surfaces have also been measured, to determine the direction of the movement. meso-structural data, related to the sets of fractures and faults, have also been represented by stereodiagrams, consisting of equal-area projections plotted in the lower hemisphere with the stereonett software. the quaternary sequence has been identified based on the distribution, facies of sediments and morphological features (morainic ridges, fluvial fans and landslide bodies). the difficulties encountered in the fieldwork were related to the scarcity of outcrops and the wide distribution of debris and colluvial deposits. these sediments, diffusely covering the bedrock and the other quaternary sediments, are essentially linked to the p. leysser dsgsd. 3. geographical, climatological and seismological setting the examined area is located in the central aosta valley (nw italy), one of the main valleys of the western alps (457480n latitude and 072190e longitude). the aosta valley is a wide mountain basin (3262 km2), consisting of a 100 km long main valley (dora baltea valley) and of about thirty major tributary valleys. monte bianco (4810 m), monte rosa (4634 m), monte cervino (4478 m) and gran paradiso (4061 m) are the highest peaks (fig. 1). this basin shows high average gradients between the valley floors and the ridges of more than 1500 meters (3500 m is the largest difference in height, recorded in the monte bianco massif). the altitude (2100 m on average) promotes the development of numerous glaciers (209). according to the aosta valley catalogue of glaciers (data of 2005), they have an overall extent of approximately 135 km2 (4.1% of the basin). the becca france landslide event occurred in the clusellaz valley, a small (15.6 km2) tributary valley now completely free of glaciers (cv in fig. 2). a rocky threshold occurs (150 m height) above arpy (1758 m) (at in fig. 2), deeply incised by the watercourse. this fig. 1 geographical and geomorphological sketch of the area, comprising the p. leysser dsgsd. the becca france ridge is involved in a remarkable set of wnw-ese doubled ridges. the digital terrain model of the aosta valley, in which the present glaciers are mapped, shows the location of the area of investigation. geological context of the becca france historical landslide … 127 threshold separates the valley floor into two stretches. the upper clusellaz valley (9.8 km2) shows a very large w-e valley floor. this 3.3 km long stretch has a markedly asymmetrical cross section. its left side, including the southern slopes of mont fallère (3061 m), mont d’ars (2826 m), mont de la tsa (2741 m), pointe de chaligne (2608 m) and pointe de metz (2552 m), is much wider and higher than the opposite side, including only the northern slope of the becca france ridge (2347-2312 m) (bf in fig. 2). the left side is also shaped by five short tributary nnw-sse valleys (clapin, fallère, feuilles, morgnoz and chesère) (fig. 1). the lower clusellaz valley (5.8 km2), deeply incised, has a wsw-ene quite symmetrical cross-section. most of the valley floor (3.3 km of a total length of 4 km) is filled by the becca france landslide accumulation (1605-800 m). another rocky threshold occurs (t in fig. 2), buried by the landslide body, in which the hanging tributary valley overlooks the main valley (1200 m). an alluvial fan, on which the sarre village is located, extends in the dora baltea valley floor at the t. clusellaz incision outlet (700 m). the aosta valley has a temperate oceanic climate, transitional to hemi-continental, lacking of a dry season (mercalli et al., 2003). the mean annual temperature is 10÷12°c in the valley floor and -7.5°c at 1200 m. january is the coldest month and july is the warmest. rainstorms are frequent in july and, to a lesser degree, in august. the region has an alpine sublittoral pluviometric regime, with two maxima in the middle seasons and two minima in the summer and winter. in the central sector of the region, comprising the becca france area, the maximum rainfall occurs in the autumn (octobernovember) and the minimum rainfall is in the summer (july). the middle dora baltea valley floor is one of the driest sites in the alps (550 mm/y in s. marcel). the mean annual precipitation of about 950 mm increases both with the altitude and towards the watersheds. on the northern watershed, the gran san bernardo (2476 m), 14 km nnw of the becca france, records an average of 2000 mm/y (data set since 1817!). two weather stations are located near the survey area, in saint nicolas (5 km sw, 1196 m) and in aosta (8 km ese, 583 m). in aosta (data set since 1840) the average annual temperature ranges between 10°c and 14.5°c, with a mean january t ranging between -1° and 4°c and a mean july t of 20.4°c. the average annual precipitation is 561 mm, with the maximum rainfall in october (70.5 mm) and the minimum rainfall in july (33 mm). november, october, september, may and june are the months fig. 2 the becca france (bf) historical landslide involves the clusellaz valley (cv). it shows the typical features of a tributary glacial valley, separated from the main valley by a hanging threshold (t). another threshold near arpy (at) divides the lower clusellaz valley from the upper one. a wide fluvial fan develops at the valley outlet, built from the sarre village. the arrows indicate the distal edge of the landslide. the location of the bellon (be) and of the present thouraz (th) villages is also indicated. forno m.g. et al. 128 with the longest series of rainy days, with a record of 13 rainy days (overall 97.4 mm) in november 1996. the highest rainfall noted is 287 mm in 8 days (2000), 118 mm in 24h (1947) and 24.7 mm/h (1981). in saint nicolas (data set 19131961), the average annual precipitation is 658 mm (maximum 75.1 mm in october and minimum 40 mm during february). the aosta valley is a relatively low seismic region. a few historical major earthquakes are known for the damage (valensise & pantosti, 2001). the earthquake of 1905 in chamonix (monte bianco massif) (m = 6) and the earthquake of 1855 in the ayas valley (m = 5.8) are the strongest. the aosta valley has middle-low seismicity according to the instrumental data (data set 19681997). specifically, some tens of events of a magnitude 2-3 and only two events of magnitude 4 are recorded. a significant correlation of the regional seismicity is inferred with the right rodanochamonix and the left ospizio sottile strike-slip fault systems. during the neogene, these faults displaced the pennine and graian alps rigid block to the se. these fault systems bound the nw and se block edges, respectively (bistacchi et al., 2000). the e-w aosta-ranzola fault system, the main brittle system inside this block, does not exhibit any significant recent seismicity. instead, a concentration of shallow earthquakes of a magnitude 3 is recorded nw of the examined area into the gran san bernardo nappe, displaced by the aosta-fallère fault system. 4. geological setting 4.1. lithostratigraphic setting of the bedrock the western alps consist of three main structural domains (e.g. polino et al., 1990). the internal domain (i) corresponds to the southern alps. the external domain (ii) consists of the helvetic-dauphinoise zone. the axial sector of the chain (iii), between the penninic front and the insubric line, represents a composite nappe pile that includes the austroalpine and the penninic continental units and the piedmont zone oceanic units (fig. 3). the penninic domain is usually subdivided into the lower penninic, including the ossola valley nappes, the middle penninic, consisting of the gran san bernardo nappe system, and the upper penninic, corresponding to the internal crystalline massifs of monte rosa, gran paradiso and dora maira massifs. the piedmont zone consists of two main groups of units, the lower and the upper one, known as the zermatt-saas units (southern valais) and the combinaouilletta units (aosta valley) (bearth, 1967; dal piaz, 1974; dal piaz & ernst, 1978; dal piaz, 1999; dal piaz et al., 2010; ispra servizio geologico d’italia, 2010). the lower units preserve several eclogite relicts and consist of different ophiolite complexes. likewise, the upper units, showing a blueschist imprinting, are composed of upper jurassic (de wever & caby, 1981) to upper cretaceous calcschist (lemoine et al., 1984), with minor slices of serpentinite, metagabbro and green schist derived from the oceanic lithosphere (e.g. lagabrielle & lemoine, 1997). the examined area is located along the tectonic contact between the middle penninic and the piedmont zone. the geological survey allows us to recognize two distinct oceanic units related to the aouilletta unit, covering the tectonically deeper continental unit referred to as the gran san bernardo nappe system (see fig. 6). the gran san bernardo nappe outcrops in the northern sector of the mapped area. it consists of garnet micaschist and albitic paragneiss, with some minor bodies of metabasite (palaeozoic basement) and dolomitic metabreccia and marble (mesozoic cover). in the piedmont zone, two tectonic units, called the upper and lower tectono-metamorphic units (tmu), have been distinguished. certain stratigraphic markers are absent from each of these units and a strong alpine fig. 3 geological schematic map of the western alps: (i) the internal domain, corresponding to the southern alps; (ii) the external domain, consisting of the helvetic-dauphinoise domain; (iii) the axial sector of the austroalpine and penninic continental domains, separated by oceanic units of the piedmont zone. il: insubric line; pf: penninic front; ar: aosta-ranzola fault; lp: lower penninic; mp: middle penninic; up: upper penninic; zs: zermatt-saas like-units; ca: combin-aouilletta like-units. geological context of the becca france historical landslide … 129 deformation is observed. these features do not allow the reconstruction of specific stratigraphic successions. the lower tmu, outcropping in the central-eastern and southern sectors of the mapped area, consists of calcschist with major prasinite and paragneiss bodies. this unit is formed by phyllitic calcschist alternating with meter to hectometer bodies of prasinite with compositional banding, diffusely outcropping near the thouraz village. in the nw slope of bellon minor bodies of quartzitic gneiss, whitish albitic gneiss and micaschist, are also present. these lithological types are often closely associated with up to 20-cm-thick layers of white mica marbles. the upper tmu, outcropping in the central-western sectors of the examined area, consists of carbonate calcschist alternating with marble in decimeter thick layers. marble, locally prevalent, sporadically contains many centimetre thick layers of quartzite, probably derived from chert. layers of meta-rudstone (meta-conglomerate or meta-breccia), slightly laterally extended and up to 10-m-thick, consist of marble and dolomite clasts in a calcite matrix probably linked to debris flows. the contact between the upper and lower tmu is highlighted by a deformation zone that is marked by tectonic flakes with prevailing cargneule, gypsum and minor bodies of prasinite, micaschist and quartzite. the lithological types within the deformation zone show only random reciprocal relationships. the deformation zone, a few tens of meters thick, has important lateral discontinuity. it is well exposed in the niche of the landslide (b fig. 4) and occasionally outcrops in the ne slope near the verrogne village, where it has been involved in the p. leysser deep-seated gravitational slope deformation. the deformation zone is completely covered by the quaternary deposits n of the becca france ridge. here the boundary between the upper and lower units can only be found by comparing the different lithological features of the two juxtaposed units. the upper and lower tmu lie tectonically above the gran san bernardo nappe: all these units are folded together. an antiformal structure, developed in the plan di modzon area, involves the gran san bernardo nappe. a synformal structure is, instead, responsible for the outcropping of the upper tmu in the tsa de la comba area. both these structures, developed on a hectometer scale, deform a sin-regional foliation and show an axial nw-se trend. the tectonic contact between the gran san bernardo nappe and the lower tmu is also involved, n of the arpy and moron localities, in a decameter s-verging open fold. this e-w trending structure deforms the regional foliation dipping 70-75° towards the s. the regional foliation dips lower than 30-35° towards the s-sw in the remaining area. the bedrock is affected by numerous faults and fractures, decreasing in pervasiveness towards n. many fracture systems have been identified in the bedrock (fig. 5). in detail the fracture systems are: ٠ nw-se trending fractures ne dipping and defining the orientation of the trenches; ٠ nnw-sse primarily trending fractures ene dipping. the southwestern stretch of the detachment niche is parallel to these fractures; ٠ n-s primarily trending fractures e dipping. these structures are emphasized, into the detachment niche, by fault breccia with calcschist clasts in a carbonate matrix. where the matrix prevails, it constitutes cargneule type-rocks encrusting the detachment plane, as seen just below the niche crown; ٠ nne-ssw primarily trending fractures ese dipping; this fractures seem to have had the role of basal sliding surfaces in the becca france failure; ٠ ne-sw trending fractures se dipping; ٠ wnw-ese trending fractures ne dipping. the lateral (northern and southern) stretches of the detachment niche are parallel to it. the area of the becca france ridge is instead involved in several trenches, especially trending wnwese and nw-se, connected with the p. leysser dsgsd (see fig. 6). these trenches results from the opening of similar trending fractures, not equally represented in the gravitationally not-deformed bedrock. fig. 5 equiareal projection (lower hemisphere) of fractures in the becca france ridge (151 data). dip direction (a); strike direction (b). fig. 4 the detachment niche of the becca france historical landslide. the tectonic contact between the lower calcschist complex (a) (lower tmu in fig. 6) and the upper calcschist complex (c) (upper tmu in fig. 6) is underlined by a cargneule and gypsum level (b). the niche cuts the noticeable doubled ridge developed near the summit. forno m.g. et al. 130 fig. 6 geological map of the becca france area.   geological context of the becca france historical landslide … 131 4.2. the quaternary cover the aosta valley was extensively affected by alpine glacial modeling during all of the quaternary glaciations. the dora baltea glacier repeatedly covered the main valley was for its entire length. these events are recorded in the ivrea morainic amphitheatre at the valley outlet, ranging from the end of the early pleistocene (carraro et al., 1991) to the end of the late pleistocene (arobba et al., 1997; gianotti et al, 2008). most of studies about the aosta valley quaternary regard the glacial stratigraphy. glacial sediments were at first connected with a single major glaciation (gastaldi & martins, 1850; baretti, 1866; 1877; 1879; bruno, 1897). only baretti (1893) has described the post-glacial formations signaling the becca france landslide. subsequently, some authors focused on the “würm” glacial expansion of the dora baltea glacier, probably reaching a thickness of about 1000 m (novarese, 1915) or 1200 m (sacco, 1927) in the middle aosta valley. six glacial stadials in the ivrea morainic amphitheatre and six glacial stadials in the dora baltea valley have been identified, referred to the last glacial maximum and the lateglacial (gianotti, 2007; gianotti et al., 2008), taking into account the previous works about the mountain sector (novarese, 1915; sacco, 1927; porter & orombelli, 1982; carraro, 1992). relicts of a frontal moraine in the main valley floor, 3 km upstream sarre (680 m) prove a glacier halt in the investigated area (saint-pierre stadial), probably correlated with the gschnitz stadial (gianotti, 2007). this area (fig. 6) extends 30 km downstream from the head of the dora baltea valley, where the mont blanc glacial alimentation center developed. glacial sediments discontinuously cover the left slope of the main valley in an altimetric band of 1200 m, between the valley floor (600 m) and approximately 1800 m. the highest kame terraces of a supposed lgm age reach 1925 m above the saint nicolas village, about 6 km upstream on the left side of the main valley. morehover, till bodies and erratic boulders are widely found up to 1710 m (plan de golette) on the bellon watershed ridge, between the dora baltea valley and the clusellaz valley. on the contrary, they are not observed at greater altitudes on the same ridge. this distribution confirms that the dora baltea glacier during the last glacial maximum (lgm) did not exceed 1800 m along the sarre cross section. subglacial sediments, mainly melt-out till and lodgement till, are the facies most widely represented. these sediments cover the bedrock with discontinuous and thin bodies. they consist of very packed silty sands with faceted and striated pebbles, cobbles and boulders, markedly matrix supported, often weakly bedded. marginal glacial sediments (flow till and glaciolacustrine deposits) cover the bedrock or the subglacial till with thin restricted bodies. they consist of coarse gravel a siltysandy matrix, with a clast-supported to matrix-supported texture and a poorly defined massive stratification. thefig. 7 the verrogne valley shows the typical glacial cross section. this wide valley, with steps in the long profile, is diffusely covered by glacial sediments. forno m.g. et al. 132 se sediments generally form small kame terraces, involved in the remodeling, that are well-preserved east of combelin (1550-1620 m). in the lateral valleys, the glacial cover is linked to the clusellaz and verrogne glaciers and to their tributaries (fig. 7). the distribution of sediments suggests their reference to the lgm and to subsequent lateglacial stadials. in detail, the marginal glacial deposits are diffused especially above combroz. they are matrix supported and rich in angular clasts supplied by the calcschist overhanging walls. these sediments form moraines or small kame terraces. the lateral moraines in the upper clusellaz valley and the lateral and terminal moraines in the verrogne valley, between or and vulmian, are particularly significant. remnants of ancient glacial deposits (pre-lgm) are locally observed at a high elevation. the dora baltea glacier ancient sediments consist only in their derived remains. 4.3. the p. leysser deep-seated gravitational slope deformation the deep-seated gravitational slope deformations (dsgsds) are common in the main dora baltea valley fig. 8 the p. leysser dsgsd shows a remarkable main scarp, arched in plan, just below the crest (a). its a distal sector (b), expanded in the aosta valley floor, is incised by several watercourses: t. gaboé (gab), t. mallaley (mal), t. de vetan (vet), t. de meod (meo) and t. de verrogne (ver). the gravitational landforms, as minor scarp (s) and longitudinal trenches (t), are underlain by the snow. the location of becca france (bf) and of the villages of vetan (vt), verrogne (vr), saint nicolas (sn), saint pierre (sp) and bellon (be) are also indicated. fig. 9 the remarkable doubled ridge (700 m long, average 50 m wide and 25 m deep) on the becca france crest, observed from the south slope of the m. fallère. the tsa de la comba pasture is shown in the lower left corner. geological context of the becca france historical landslide … 133 and in its tributaries. these phenomena are currently interpreted as the product of the gravitational spreading of the slopes (crosta, 1996), usually affecting the steep sides of the deep glacial valleys. in the aosta valley 230 dsgsds have been recognized (iffi catalogue of landslides and sheets of the geological map of italy at 1:50,000 scale) covering a total area of about 460 km2 (14% of the basin). they involve all kinds of metamorphic lithotypes without significant differences. this evidence supports that dsgsds are favored and driven by tectonic discontinuities (fractures, faults and thrusts) and, on the contrary, they are less dependent on lithological features (mechanical and chemical properties and foliations). the becca france ridge is comprised in the 23 km2 wide p. leysser dsgsd, occurring in the left side of the dora baltea valley (fig. 1). this large phenomenon has not been reported in the first italian alps dsgsds catalogue (mortara & sorzana, 1987). it has been only partially mapped in the aosta valley geological map (elter, 1987) as a landslide, limited to a less extended area not including the becca france. the pointe leysser mountain ridge bounds the dsgsd (pointe aouilletta, 2616 m; pointe leysser, 2770 m; becca france, 2312 m), forming the watershed between the dora baltea and its tributary vertosan and clusellaz basins. this 8 km long watershed, only cut off by the t. verrogne incision, shows an arched in plant scarp just below the crest (a in fig. 8). it represents the very extended main scarp of the punta leysser dsgsd. the gravitational phenomenon affects the piedmont calcschist, with rare slices of prasinite and serpentinite. several minor scarps (s in fig. 8) occur in the whole area. the general extension of the collapsed rocky mass caused the opening of several nw-se longitudinal trenches (t in fig. 8), re-used by the local watercourses (gaboè, mallaley, de vetan, de meod and lower verrogne torrents) and others ephemeral streams. the dsgsd 9 km2 central sector, laterally delimited by the t. mallaley and t. de meod incisions, represents the most deformed area. its distal sector (b in fig. 8) is expanded in the aosta valley floor. the investigated sector represents the dsgsd northeastern edge (fig. 1), where a set of wnw-ese doubled ridges near the watershed (figs. 9, 10) is the more remarkable of the gravitational landforms. this evidence, with an overall length of 2 km, an average width fig. 10 the extension of the doubled ridge of fig. 9 toward the e, observed from the becca france ridge. m. emilius and p. garin are in the background. fig. 11 extended area with very fractured rocks (r), connected to the p. leysser dsgsd developed in the southern slope of the becca france above the or pasture. they may be confused with areas covered by debris sediments. a longitudinal trench, on the right, is deepened and enlarged by an ephemeral watercourse (t). forno m.g. et al. 134 of 50 m and a depth of 25 m, is abruptly interrupted, on its eastern edge, by the wide detachment niche of the historical described landslide (fig. 4). the summit doubled ridge set is not reported in the geological map (fig. 6) to permit the mapping of other gravitational evidence. a succession of minor scarps (100-500 m long, 550 m wide and 2-10 m deep) involves the upper band of the becca france sw side. several wnw-ese trenches (transversal trenches), orthogonal to the dsgsd movement, also develop in the whole slope and locally form small closed depressions. they are several tens of meters extended and a few meters deep. in the watershed sector the various fractures are only slightly open (from a millimeter to some centimeters). in the lower band of the sw slope, the fractures (§4.1) are generally up to some decimeters open. locally wide bedrock outcrops simulate the presence of debris sediments: here the very pervasive and partially open fractures favor a strong erosion of the bedrock and many secondary surficial landslides. some concave pluri-decametric niches locally develop with badland morphology (r in fig. 11). they are probably related to accelerated erosion rather than to a landslide. these niches open at the head of a flat-bottomed deep incision, likely corresponding to longitudinal trenches used and remodeled by debris flow and alluvial processes (t in fig. 11). an ensemble of similar longitudinal trenches, variously re-used by avalanches and minor watercourses, was recently described in the western alps along the germanasca valley (forno et al., 2011). some gravitational discontinuities are also visible in the becca france landslide niche, being a wide outcrop of bedrock involved in a dsgsd (fig. 4). these fig. 12 in the northern slope of the becca france ridge, a uphill-facing scarp (arrows) develops, linked to the dsgsd phenomenon. fig. 13 the greatest rise of the landslide accumulation on the left side of the clusellaz valley (dashed line) is noticeable by the different colors of the trees (view from the niche crown). geological context of the becca france historical landslide … 135 discontinuities are difficult to identify into the very fractured bedrock. some sliding surfaces are suggested by the rocky layers displacements. in detail, a sliding surface has lowered the gypsum-cargneule layer of more than 50 m in a sw direction, forming the double ridge morphology visible in the niche crown. other gravitational elements are observed on the nne side of the becca france ridge. here a main continuous low angle uphill-facing scarp forms a 500 m long ledge (2220-2230 m, 50 m above the clusellaz valley floor) (arrows in fig. 12). it marks the boundary between differently fractured calcschist. this discontinuity can be likely interpreted as a slipping plane dipping southwards. therefore this scarp, apparently outside the p. leysser dsgsd, is probably the lower visible evidence of the gravitational deformation. doubled ridges, slide scarps and trenches show various relationships with the last glacial maximum-lateglacial cover. the gravitational evidence frequently cuts the glacial evidence (tsa de la comba): in these sites, the dsgsd dislocates the glacial cover (forming scarps in which the sediments outcrop) and cuts through the glacial and outwash landforms. glacial evidence elsewhere modifies the gravitational landscape (plan di modzon). the ancient verrogne glacier, entering into trenches, probably enlarged them and partly deprived them of their primary typical shapes. the lower verrogne valley is the most notable result of the interaction between the glacial and deep gravitational processes. this wide and u-shaped incision, with a nnw-sse direction perpendicular to the contour lines, is probably linked to a longitudinal trench enlarged by the verrogne glacier, during the lateglacial (fig. 7). other similar longitudinal trenches w of the verrogne valley, with a broken line trend and a v-shaped cross section, have been instead re-used by watercourses (t in fig. 8). the different relationship between glacial and gravitational morphology suggests a long evolution of the p. leysser dsgsd from the lgm to the present. 5. the becca france landslide the historical phenomenon of the becca france landslide (july 6, 1564) produced a wide scarp on the eastern slope of the becca france ridge (2312 m) and a huge accumulation within the lower clusellaz valley, 6 km nw of the town of aosta (fig. 2). the becca france landslide, historically already well-known (§1), has been reported in an ancient geological investigation of the aosta valley (baretti, 1893). in the “aosta” 1:100,000 geological map of italy (mattirolo et al., 1912), in which the landslides were not indicated, a morainic cover and, subordinately, debris sediments were represented instead of the becca france accumulation. the priest and naturalist abbé henry (1917), on a day trip, first observed some deep fissures on the becca france crest and the morphology with ridges of the landslide accumulation. this evidence has suggested to the author an important rule of the water in the gravitational event, linked to heavy rains. no detailed cartographies of the accumulation are reported in the overall aosta valley geological map at the 1:100,000 scale (elter, 1987; de giusti et al., 2004). a first brief geological description of the becca france landslide is, finally, reported in forno et al. (2004). 5.1. geomorphic features geological and morphological features of the becca france landslide have been mapped (fig. 6). the lithology of the detachment niche, the morphology and the petrographic composition of the landslide body have been analyzed in detail. the evident detachment niche corresponds to a steep concave scarp, approximately 500 m high (23001800 m), 850 m wide and 700 m long, without vegetation cover (fig. 4). the niche crown, arched in plan, comprises two main stretches trending nnw-sse and wnwese. the two niche stretches follow the fracture systems of the bedrock. the niche cuts the becca france crest and, in detail, breaks off the main wnw-ese doubled ridge developed on the watershed (fig. 4) (§4.3). the lithological constitution of the niche consists of two overlapping units (§4.1), separated by a tectonic contact underlain by a cargneule and gypsum level, some tens of meters thick (b in fig. 4). at the base of the niche, the lower tmu outcrops, composed of a 150 m thick prasinite body, covered by an approximately 170 m thick calcschist body (a in fig. 4). at the top of the niche, the upper tmu is instead composed only of a 150 m thick calcschist body (c in fig. 4). the niche is widely covered by debris and local rockfall deposits, forming a 35°-36° slope. the bedrock diffusely outcrops only in the higher band (1950-2300 m). the debris sediments, with an open-work texture, are made of angular clasts, from some centimeters to a fig. 14 the facies of the landslide accumulation consists in angular clasts of very different sizes, mixed to a poor, slightly packed, sandy and silty matrix. forno m.g. et al. 136 few decimeters in size. obviously their petrographical constitution (90% calcschist and grafitic calcschist, 10% prasinite with rare cargneule clasts) strictly reflects the niche lithology. these sediments locally contain rounded clasts, related to the reworking of ancient glacial sediments. the landslide accumulation, located in the glacial clusellaz valley, is 3.2 km long and 300-940 m wide. it shows a total extent of 1.26 km2, covering the elevation range between 1800 m and 800 m. in detail, the landslide body partly (18%) extends on the right side of the valley, immediately below the detachment niche (proximal sector) and partly (82%) appears lengthened into the valley floor, covering the lower band of both the valley sides (for over 3 km) (middle-distal sector) (fig. 13). between these two accumulation sectors, a gentle nnw-sse depression is partly buried by debris flow deposits, coming from the detachment niche. the upper sector shows a cone landform, now partially covered by debris sediments. the lower landslide body rises on the opposite (left) side of the valley, in front of the niche, for approximately 80 m of elevation, where a typical blocky ridge occurs at the culmination (brandung in heim, 1932). the accumulation toe overlooks the dora baltea valley and reaches the main valley floor at 800 m. the landslide accumulation shows a different slope, high immediately below the detachment niche (average 23°) and slight in the lower sector (average 15°). the lower sector, entrenched into the clusellaz valley floor, shows some remarkable lengthened ridges parallel to the valley trend (flowbands), a ten of meters high, separated by depressions (fig. 13). the main ridges, linear or arched in plan, are alternately distributed on the opposite sides of the valley. five main ridges develop (550÷200 m length), relatively continuous for a few hundreds of meters in the valley floor (fig. 6). several changes in the slope of the landslide body are likely related to the presence of buried rocky scarps shaped by subglacial erosion (buried thresholds in fig. 6). the ridges break off on these thresholds and begin again downstream. the landslide deposits show a visible thickness of approximately ten meters, as calculated by the height difference between the ridge crests and the depressions; the lack of wide outcrops prevents the observation of the entire sedimentary body. they consist of a chaotic pile of rock angular clasts, some tens of centimeters to a few thousand of m3 in size (fig. 14). several lengthened blocks are prevalently arranged parallel to the ridges. the subordinate sand-gravelly matrix is poorly consolidated in the surficial layer. coarse-grained sediments with an open texture develop on the ridges, probably related to the removal of an original scanty matrix. the petrographic constitution of the ridges is partially different. prasinite and prasinite-gneiss blocks constitute the external ridges. prasinite, prasinite-gneiss, calcschist, grafitic calcschist and marble schist blocks form the intermediate ridges. calcschist, grafitic calcschist and marble schist clasts, with locally abundant cargneule, constitute the internal ridges. a gently-dipping and some meters thick band of crushed and pulverized cargneule discontinuously outcrops in the middle sector of the accumulation, probably separating two bodies of calcschist blocks. the entire distal sector, below 1300 m, consists only of prasinite blocks. a total drop height of 1500 m, a runout distance of 4150 m and an accumulation thickness of 10 m on average and a 30 m maximum are the main geometrical parameters of the landslide. the volume of 15-25 million m3 has been assessed using the accumulation area and the estimated average thickness, based on a preliminary geophysical cross section. 5.2. the landslide remodeling the t. clusellaz, in spite of the recent age of the landslide dissects the accumulation. lengthened debris flow bodies develop, confined in the watercourse incision, entrenched into the landslide accumulation and further terraced (fig. 6). these debris flow bodies, composed of calcschist, graphitic schist and cargneule clasts, form two terraces parallel to the watercourse. a thin band of present torrential sediments develops into the riverbed. in addition, on the left slope, two secondary landslide accumulations develop, 50,000 and 300,000 m3, respectively. their detachment niches occur into the main landslide body, cutting its parallel ridges. in the clusellaz valley floor, under the detachment niche, debris flow sediments bury a wide sector of the landslide accumulation. they have been derived from the reworking of the debris that diffusely covers the niche. here the loosened bedrock outcropping into the niche favours the progressive detachment of rocky bodies of various sizes. the landslide body is covered by a continuous larch and pine wood (larix decidua and pinus nigra). the plant cover differs from the woods without pines on the adjacent sectors (dotted line in fig. 13). some springs (sources du ruet) arise on the landslide body, into a relict channel in the next of the t. clusellaz incision. they are linked to the high permeability of the deposits and suggest a low permeable substratum in the immediate subsoil (bedrock or subglacial till) and consequently a local weak thickness of the landslide body. 6. discussions and conclusion the geological survey allows the detection of two superposed calcschist units, separated by a deformation zone (fig. 6), and to the contrary of the unique aouilletta unit reported in the geological literature. this zone, a few tens of meters thick, prevalently consists of cargneule, gypsum and very subordinate quartzite. the regional foliation dips below 30-35° towards the s-sw. this survey allows the description of the gravitational evidence connected to the p. leysser dsgsd (fig. 8), as remarkable doubled ridges (fig. 1), several minor scarps as well as longitudinal and transversal trenches. their trend suggests that the regional foliation and lithostratigraphical setting favor the gravitational landforms. the gravitational movements prevalently reuse the previous tectonic systems surfaces. the wide becca france landslide is also mapped with greater extension and detail than in the previous maps. the detachment niche is particularly remarkable, corresponding to a 500 m high and 850 m wide scarp, arched in plan. it shows a cirque-like morphology (turnbull & davies, 2006). geological context of the becca france historical landslide … 137 the accumulation is of approximately 1.26 km2 wide and up to about 30 meters thick, covering an elevation range of 1000 meters. it consists of an incoherent ensemble of angular rock fragments of various sizes. its varied, but very sorted, petrographical composition is a good example of “remnant stratigraphy” (heim, 1932). the upper (proximal) sector of the landslide accumulation is immediately below the detachment niche, with a cone landform typical of a rockfall. the lower (middle-distal) sector is entrenched in the clusellaz valley floor and shows instead a wide distribution and some parallel ridges typical of a rock avalanche. rock avalanches (ra) are catastrophic gravitational events occurring suddenly, with very high rates of movement (100-250 km/h) and great sizes (>106 m3). they have a rapid runout and emplacement of crushed and dry rock for distance of several kilometers (hewitt et al., 2008). many ra are listed into the alps (heim, 1932; abele, 1974; eisbacher & clague, 1984; von poschinger, 2002). in the aosta valley they are the prehistoric courmayeur (about 600 bc; porter & orombelli, 1981) and cervino landslides (> 1000 ad; porter & orombelli, 1981), the historical triolet ra (1717 ad; porter and orombelli, 1980; deline & kirkbride, 2009), the two brenva events from the mont blanc massif (1920 and 1997 ad; dutto & mortara, 1991; barla et al., 2000; deline, 2001; bottino et al., 2002) and the recent luseney ra in valpelline (1952 ad; dutto & mortara, 1991). they have prevalently runout onto glaciers, with the likely exception of the courmayeur ra, because of its unknown source, and of the luseney ra only slipped onto a suspended glacieret. on the contrary, the becca france landslide is the only known event in the aosta valley occurred in a completely free of glaciers basin. the magnitudo of the becca france accumulation (estimated volume of 15-25 x 106 m3) is in agreement with the minimum values requires for rock avalanches. its maximum runout distance (l = 4100 m) is 2,7 times the total fall height (h = 1500 m). the l/h ratio is significantly lower than the characteristic values of 5-10 times often assigned for rock avalanches. it is instead consistent with the l/h ratios between 0,6 and 8,3 assigned for 36 rock avalanches (hewitt et al., 2008), although below their average (4,0). the becca france landslide is, according to the few cases reported in the literature, a rather rare example of rock avalanche with longitudinal ridges. the flims landslide in the swiss alps (abele, 1997), the mutzogata ra in the eastern pamir (fort & peulvast, 1995) and the ghoro choh i in karakoram himalaya (hewitt et al., 2008) have similar features (eg the ghoro choh i ra shows five longitudinal ridges up to 3 km long and 10-30 m high). the slide lake ra in montana (butler et al., 1986), with a longitudinal ridge 1.25 km long and 15 m high, seems the more comparable event. the rock avalanche bodies with transversal ridges are, instead, more common. the morphology of the distal sector of the accumulation (overall homogeneity and lack of intersections) allows the attribution to a unique rock avalanche event. this event involved the calcschist of the lower tmu, the cargneule of the deformation zone and partly the overlying calcschist of the upper tmu (fig. 6). the genesis of the proximal sector is, instead, more questionable. it is probably linked to a rockfall phenomenon with minor energy, simultaneous with the rock avalanche and involving only the calcschist of the upper tmu (fig. 6). alternatively this proximal sector should be connected with another gravitational event after the rock avalanche, covering partially the empty space between the niche and the lower body. the predisposing factors of the landslide occurrence are then preliminarily specified. ٠ the strong relief energy, with high mountains up to over 3000 m (m. fallère, 3061 m; p. leysser, 2770 m) and relatively low valley floors, developed at about 600 m (fig. 2). in detail, the sufficiently high gradient of the right slope of the becca france ridge (average slope of 32°) is to be considered. ٠ the overall geological context. the outcropping calcschist, with poor geomechanical properties, is defined among the more frequent causes of the nw alpine large landslide (mortara & sorzana, 1987; forno, 1989; forno & massazza, 1983; 1987). the high grade of rock fracturing, linked to the tectonic setting, favored the detachment. cargneule and gypsum, along the tectonic contact between the two calcschist units, subjected to chemical dissolution, cause sinking and gravitational collapse of the overlying rock mass. the filling of fractures by cargneule, sometimes successively affected by dissolution, is also a possible aid to the landslide movement. the most obvious example is the evident sub-vertical fault observed in the detachment niche, encrusted with cargneule, simulating a thick cargneule body (fig. 4). this surface before had been an open fracture, with carbonate fluids circulating, and successively probably became one of the main surfaces responsible for the detachment phenomenon. ٠ the wide p. leysser dsgsd. this gravitational deformation multiplies and enlarges the tectonic fractures, creates new sliding surfaces and promotes scarps and uphill-facing scarps. the continuous summit doubled ridge, cut by the landslide niche, is the more remarkable evidence of the importance of the gravitational factors. the rock avalanches are statistically slightly linked to the dsgsds, although these latter are very common in the mountain areas (hewitt et al., 2008). this scarce connection between rock avalanches and dsgsds is related to the rheology of the very jointed involved rocks. the dilated bedrock is unsuitable to forming high scarps and to trigger large slope failures, both necessary for the ra runout. nevertheless, some rock avalanches triggered by dsgsds are reported, as numerous events in norway (blikra et al., 2006), the nomal ra (hewitt, 2001) and the gol ghone i ra in karakoram (hewitt, 2002) and the hope ra and frank ra in western canada (cruden & krahn, 1978). in the becca france ra the slope failure occurred at the edge of the p. leysser dsgsd, from the opposite side of the rocky divide forming the dsgsd main scarp, where a relatively high-energy relief occur and the bedrock is not totally crushed. the trigger factors of the becca france landslide are not historically well-known. both a seismic source (reference in fenoil, 1883) and an interval of extremely forno m.g. et al. 138 heavy rainfall (henry, 1917; colliard, 1970; rampolla, 1981) have been reported in the past, although without evidence. this rainfall may be responsible for an increase in the interstitial pressure of the water in the rocks, producing their collapse. a possible seismic event is instead described in an administrative act, written only a year after the landslide. however, the shock felt could have been a consequence of the landslide, but not necessarily its cause. acknowledgments the authors are grateful to the soprintendenza per i beni e le attività culturali of the regione autonoma valle d'aosta for the logistic and financial support. we also thank g. orombelli and an anonymous reviewer for their comments to the manuscript and the useful suggestions. references abele g. (1974) bergstürze in den alpen, ihre verbreitung, morphologie und folgeerscheinungen. wissenscahftliche alpenvereinshefte, 25, pp. 230 abele g. (1997) rockslide movement supported by the mobilization of water saturated valley floor sediments. z. geomorphol. n.f., 41, 1-20. arobba d., calderoni g., caramiello r., carraro f., giardino m., quagliolo p. (1997) palynological and radiometric evidence of a last glacialinterstadial from peat sediments in the ivrea morainic amphiteatre (nw italy). geologia insubrica, 2(2), 143-148. baretti m. (1866) i ghiacciai antichi e moderni. degree thesis in natural sciences, university of bologna, edizioni candeletti, torino. baretti m. (1877) studi geologici nel gruppo del gran paradiso. atti reale accademia lincei 3(1), roma, pp. 122. baretti m. (1879) studi geologici sulle alpi graie settentrionali. memorie reale accademia lincei 3, roma, pp. 101. baretti m. (1893) geologia della provincia di torino. edizioni casanova, torino, pp. 732. barla g., dutto f., mortara g. (2000) brenva glacier rock avalanche of 18 january 1997 on the mount blanc range, northwest italy. landslide news, 13, 2-5. bearth p. (1967) die ophiolite der zone von zermattsaas fee. beitr. geol. karte schweiz, nf, 132, pp. 130. bistacchi a., eva e., massironi m., solarino m. (2000) miocene to present kinematics of the nw-alps: evidence from remote sensing, structural analysis, seismotectonics and thermochronology. journal of geodynamics, 30, 205-228. blikra l.h., longva o., braathen a., anda e., dehl j.f., stalsberg k. (2006) rock slope failures in norwegian fjord areas: examples, spatial distribution and temporal patterns. in: evans s.g., scarascia mugnozza g., strom a.l., hermanns r.l. (eds.), landslides from massive rock slope failure. proc. nato advanced workshop, 475-496, celano, italy, june 2002. springer-verlag, dordrecht. bollati e. (1988) le congregazioni dei tre stati della valle d’aosta (les etats généraux de la vallée d’aoste). i-ii, réimpression anastatique, aoste. bottino g., chiarle m., joly a., mortara g. (2002) modelling rock avalanches and their relation to permafrost degradation in glacial environments. permafrost and periglacial processes, 13, 283-288. bruno l. (1897) studi intorno al fenomeno glaciale nella vallata della dora baltea. rivista geografica italiana, 4, 253-260. butler d.r., oelfke j.g., oelfke l.a. (1986) historic rockfall avalanches, northeastern glacier national park, montana, u.s.a. mountain res. develop., 6, 261-271. caniggia m., limonet m., poggianti l. (1999) thora. storia di un antico villaggio scomparso. tipografia testolin, chesallet di sarre, pp.126. carraro f. (1992) la zona pedemontana da ivrea ad arona. depositi quaternari. in: dal piaz g.v. (ed.), le alpi dal monte bianco al lago maggiore, società geologica italiana, guide geologiche regionali, 3(a), 186-209, bema, milano. carraro f., lanza r., perotto a., zanella e. (1991) l’evoluzione morfologica del biellese occidentale durante il pleistocene inferiore e medio, in relazione all’inizio della costruzione dell’anfiteatro morenico d’ivrea. bollettino museo regionale scienze naturali, torino, 9(1), 99-117. cerutti a., borney p., ceriano i. (1993) saint-pierre. edizioni musumeci, quart, italy. colliard l. (1970) totius vallis augustae compendiaria descriptio. manuscrit attribué au père daniel monterin, rédigé avant 1675. archivum augustanum, 4, aosta. crosta g. (1996) landslide, spreading, deep seated gravitational deformation: analysis, examples, problems and proposals. geografia fisica dinamica quaternaria, 19, 297-313. cruden d.m., krahn j. (1978) frank rockslide, alberta, canada. in: voight b. (ed.), rockslides and avalanches, 1. natural phenomena, elsevier, amsterdam, 97-112. dal piaz g.v. (1974) le métamorphisme alpin de haute pression et basse température dans l’évolution structurale du bassyn ophiolitique alpino-appenninique. 1e partie: boll. soc. geol. it., 93, 437-468; 2e partie: schweizerische mineralogische und petrographische mitteilungen, 54, 399-424. dal piaz g.v. (1999) the austroalpine-piedmont nappe stack and the puzzle of alpine tethys. memorie scienze geologiche, padova, 51(1), 155-176. dal piaz g.v., ernst w.g. (1978) areal geology and petrography of eclogites and associated metabasites of the piedmont ophiolite nappe, breuilst. jacques area, italian western alps. tectonophysics 51, 99-126. dal piaz g.v., gianotti f., monopoli b., pennacchioni g., tartarotti p., schiavo a (2010) note illustrative del foglio 091, “châtillon” della carta geologica d’italia alla scala 1:50.000 ispra servizio geologico d’italia. de giusti f., dal piaz g.v., massironi m., schiavo a. (2004) carta geotettonica della valle d’aosta. memorie scienze geologiche, padova, 55, 129-149. geological context of the becca france historical landslide … 139 deline p. (2001) recent brenva rock avalanches (valley of aosta): new chapter in an old story? suppl. geogr. fis. dinam. quat., 5, 55-63. deline p., kirkbride m.p. (2009) rock avalanches on a glacier and morainic complex in haut val ferret (mont blanc massif, italy). geomorphology, 103, 80-92. de wever p., caby r. (1981) datation de la base des schistes lustrés post-ophiolitiques par des radiolaires (oxfordienkimmeridgien moyen) dans les alpes cottiennes (saint véran, france). comptes rendus académie sciences, paris, 292, 467-472. dutto f., mortara g. (1991) grandi frane storiche con percorso su ghiacciaio in valle d'aosta. rev. valdôtaine d'hist nat., 45, 21-35. eisbacher g.h., clague j.j. (1984) destructive mass movements in hight mountains: hazard and management. geol. survey of canada, paper 84-16, pp. 228 elter g. (1987) carte géologique de la vallée d’aoste, échelle 1:100.000. c.n.r. centro studi sui problemi dell’orogeno delle alpi occidentali, edizioni s.e.l.c.a., firenze, italy. fénoil f., 1883. ca et là. souvenirs valdotains, imprimerie edouard duc, aosta, italy, 166-194. forno m.g., gianotti f., paganone m. (2004) la grande frana storica della becca france (valle d’aosta, italia): un esempio significativo di accumulo di frana a cordoni paralleli. in: “la geologia del quaternario in italia: temi emergenti e zone d’ombra”, 114-115, convegno aiqua e cnr, 16-18 febbraio 2004, roma. forno m.g., lingua a., lo russo s., taddia g. (2011) improving digital tools for quaternary field survey: a case study of the rodoretto valley (nw italy). environmental earth sciences, 64, 1487-1495. forno m.g., massazza g. (1987) movimenti gravitativi diffusi e ripetuti nel versante sinistro della val cenischia (alpi graie) e loro relazione con il sistema di fratture cenischia nizza. geografia fisica dinamica quaternaria, 10, 277-306. forno m.g., massazza g. (1983) segnalazione di un gruppo di “paleofrane”nel tratto della valle d'ayas compreso tra gli abitati di lignod ed extrepiera (valle d’aosta). geografia fisica dinamica quaternaria , 6, 137-147. forno m.g. (1989) osservazioni su alcune frane oloceniche di grandi dimensioni nel settore alpino occidentale. bollettino società geologica italiana, 108, 409-418. fort m., peulvast j.p. (1995) catastrophic massmovements and morphogenesis in the peri-tibetan ranges: examples from west kunlun, east pamir and ladakh. in: slaymaker o. (ed.), steepland geomorphology, wiley, ny, 171-198. gastaldi b., martins ch. (1850) essai sur les terrains superficiels de la vallée du pô aux environs de turin, comparés à ceux du bassin helvetique. bulletin société geologique france, 7, 509-553. gianotti f. (2007) stratigrafia dell’anfiteatro morenico di ivrea. ph.d. thesis, not published, università studi torino, pp. 254. gianotti f., forno m.g., ivy-ochs s., kubik p.w. (2008) new chronological and stratigraphical data on the ivrea amphitheatre (piedmont, nw italy). quaternary international, 190, 123-135. heim a. (1932) bergstürz und menschenleben. fretz and wasmuth, zürich, pp. 218 henry j.m. (1917) becca france. bulletin société flore valdotaine, 13, 49-64. hewitt k. (2001) catastrophic rockslides and the geomorphology of the hunza and gilgit river valleys, karakoram himalaya. erdkunde 55, 72-93. hewitt k. (2002) styles of rock avalanche depositional complex in very rugged terrain, karakoram himalaya, pakistan. in: evans s.g., de graff j.v. (eds.), catastrophic landslides: effects, occurrence and mechanisms. geol. soc. amer. rev. eng. geol., 15, 345-378. hewitt k., clague j.j, orwin j.f. (2008) legacies of catastrophic rock slope failures in mountain landscapes. earth-science reviews, 87, 1-38. ispra servizio geologico d’italia (2010) foglio 091 “chatillon” della carta geologica d’italia alla scala 1:50.000. lagabrielle y., lemoine m. (1997) alpine, corsican and apennine ophiolites: the slow-spreading ridge model. comptes rendus académie sciences, paris, 325, 909-920. lemoine m., marthaler m., caron j.m. (1984) découverte de foraminiféres planctoniques du crétacé supérieur dans les schistes lustrés du queyras (alpes occidentales). conséquences paléogéographiques et tectoniques. comptes rendus académie sciences, paris, 229, 727-732. mattirolo e., novarese v., franchi s., stella a. (1912) foglio 28 “aosta” della carta geologica d’italia a scala 1: 100.000, ia edizione, servizio geologico d’italia, roma. mercalli l., castellano c., cat berro d., di napoli g., guindani n., montuschi s., mortara g., ratti m. (2003) atlante climatico della valle d’aosta. società meteorologica subalpina, torino, pp. 405. mortara g., sorzana p.f. (1987) fenomeni di deformazione gravitativa profonda nell’arco alpino occidentale italiano. considerazioni lito-strutturali e morfologiche. bollettino società geologica italiana, 106, 303-314. novarese v. (1915) il quaternario in valle d’aosta e nelle valli del canavese. parte iii: gli stadi postwurmiani. bollettino reale comitato geologico italia, 45(3-4), 137-194. polino r., dal piaz g.v., gosso g. (1990) tectonic erosion at the adria margin and accretionary processes for the cretaceous orogeny of the alps. in: f. roure, p. heitzmann, r. polino (eds.), deep structure of the alps. société geologique de france, société geologique suisse, società geologica italiana, 345-367. porter s.c., orombelli g. (1980) catastrophic rockfall of september 12, 1717 on the italian flank of the mont blanc massif. z. geomorphol., 24, 200-218. porter s.c., orombelli g. (1981) alpine rockfall hazards: recognitions and dating of rockfall deposits in the western italian alps lead to an understanding of the potential hazards of giant rockfalls in mountainous regions. american scientist, 69, 67-75. porter s.c., orombelli g. (1982) late-glacial ice advances in the western italian alps. boreas, 11, 125-140, oslo. forno m.g. et al. 140 rampolla a. (1981) alluvioni, frane e fenomeni correlativi in valle d’aosta e la loro influenza sul paesaggio. thesis not published, università di torino. sacco f. (1927) il glacialismo nella valle d’aosta. ministero lavori pubblici, servizio idrografico, ufficio idrografico po, edizioni checchini, torino, pp. 66. turnbull j.m., davies t.r.h. (2006) a mass movement origin for cirques. earth surphace rev. landforms, 31, 1129-1148. valensise g., pantosti d. (eds.) (2001) data base of potential sources for earthquakes larger than m 5.5 in italy. ingv, roma. von poschinger a. (2002) large rockslides in the alps: a commentary on the contribution of g. abele (1937-1994) and a review of some recent developments. in: evans s.g., degraff j.v. 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documenti pdf creati possono essere aperti con acrobat e adobe reader 5.0 e versioni successive.) /enu (use these settings to create adobe pdf documents suitable for reliable viewing and printing of business documents. created pdf documents can be opened with acrobat and adobe reader 5.0 and later.) >> >> setdistillerparams << /hwresolution [1200 1200] /pagesize [396.850 566.929] >> setpagedevice available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 63 67 mercury dispersion from the mt. amiata mining district to the upper reach of the paglia river (central italy): a geomorphological-geochemical approach defines the interaction between river deposits and mining activity antonella colica 1 , marco benvenuti 1 , laura chiarantini 2 , pilar costagliola 1 , pierfranco lattanzi 3 , valentina rimondi 1 , massimo rinaldi 1 1 dipartimento di scienze della terra, università di firenze, firenze, italy 2 mema, università di firenze, firenze, italy 3 cnr-igg, uos firenze, firenze, italy corresponding author: a. colica <antonella.colica@gmail.com> abstract: the paglia river drains the mt. amiata mercury district (the 3rd most important district worldwide exploited from 1880 to 1980) before becoming a tributary of the tiber river. a combined geochemical-geomorphological approach was applied to understand hg distribution in the fluvial morphological units (mus). the hg mean values in the terraces (here after indicated as tn) seem to be linked to the mining activity: t1, formed before the activity, has values within the local background (2÷6 mg/kg); t2, t3 and t5, formed either at the beginning or in the final phases, have values lower than 9 mg/kg; t4, formed during the peak activity, has 26 mg/kg. the current baseflow channel and bar have mean value of 9 mg/kg. the high value of the modern floodplains (19 mg/kg) could be related to intense flood events causing greater erosion of contaminated mus upstream. the total contained mass of hg in the studied stretch is estimated at 63 tonnes. keywords: fluvial sediments, fluvial dynamics, morphological units, hg contamination 1. introduction between the 1880s and 1980s, the mt. amiata mining district (mamd), located in southern tuscany (italy), produced about 102,000 tonnes of hg and released into the environment not less than 30,000 tonnes of hg (benvenuti & costagliola, 2016, and references therein). mamd is located within the catchment of the paglia river, the main tributary of the tiber river, which flows directly into the mediterranean sea. in this study, an integrated geomorphological and geochemical approach was used to interpret and understand temporal and spatial contaminant distribution in the upper catchment of the paglia river. the analysed stretch of the paglia river extends over about 43 km from the source near abbadia san salvatore, where the most important hg mine of the district was located, to allerona scalo in umbria (fig. 1). the area of interest covers about 720 km2, straddling southern tuscany, northern lazio and central umbria. the shape of the basin and the hydrographic net are mainly linked to the structural characteristics of two grabens: radicofani and paglia-tiber (fig. 1). the main lithologies cropping out along the paglia river belong to a quaternary continental deposit complex (marroni et al., 2015), characterized by: (1) holocene fluvial deposits (pebbles in a mainly sandy-silty matrix), the paglia river cuts through its alluvial deposits locally forming various orders of terraces; and (2) pleistocene fluviallacustrine deposits (mainly conglomerates with sandysilty beds and levels). these last deposits are arranged on large terraced surfaces located at altitudes from 5 to 20 m above the current course of the paglia river (e.g. pleistocene terrace in fig. 1). 2. methods and data collection the paglia river is a relatively high-energy, dynamic river, characterized by a sequence of channel adjustments in its catchment, occurred during the period of mining activity and during the last decades. to understand this evolution, the multi-scale approach developed by rinaldi et al. (2013, 2015) and gurnell et al. (2016) was used. on this basis a series of landscape units (lus), segments and reaches were identified (fig.1). the lower hierarchical spatial order is the morphological unit (mu), i.e. an area within the floodplain channel containing a landform created by erosion or deposition of sediment, sometimes in association with vegetation. a multi-temporal analysis of the paglia river changes was performed to evaluate the evolution of channels and floodplains, and to try and date the recent terraces and modern floodplains formed during the time interval from the beginning of mining activity to present. this analysis was restricted to the following three key years: (1) the first topographic maps produced by the igm (istituto geografico militare) dating from 1883 (scale 1:50,000), coinciding with the initial period of mamd activity; (2) aerial photos from 1954 (igm gai, scale 1:33,000) corresponding to the highest production period of mamd activity; (3) aerial photos from 2012 (environmental ministry, scale 1:10,000), corresponding to the available most recent and best resolution aerial photos. maps and aerial photos were processed by gis https://doi.org/10.26382/aiqua.2018.aiquaconference analysis (using arcgis 9.3). multitemporal analysis of channel changes was then used to support interpretation and classification of the mus related to the channel evolution occurring during the investigated period. this gis-based analysis was validated by field surveys. 2.1. geomorphological field characterization of sampling transects a sampling transect was identified for each fluvial reach. a total of 11 sampling transects were selected (10 along the paglia river and 1 along siele creek, a tributary of paglia r.; fig. 1). the mus are classified (according to rinaldi et al., 2016) within two broad spatial domains, bankfull channel (baseflow channel c and bars -b) and floodplain. the latter is strongly influenced by recent channel dynamics. the channel incision and narrowing of the paglia river, occurred approximately during the last 150 years, determined the formation of a series of ‘recent terraces’ (t2, t3, t4 and t5), i.e., former historical levels of floodplain that became a terrace because of bed incision; whereas the most recent alluvial, flat surface adjacent to the river created by lateral and vertical accretion under the present river flow and sediment regime is here classified as ‘modern floodplain' (fp see belletti et al., 2016). for each transect, a profile representing the distribution, lateral extension and elevation of the different mus was obtained. the lengths (parallel and perpendicular to the watercourse) of each mu along each transect were measured on aerial photos and maps. in order to get an estimation of the volumes of overbank fine sediments accumulated within the wide channel of 1883, the thickness of the overbank fine sediments overlying the gravel bed deposits was estimated by a hand borer. then the area of each polygon of the different mus deposited after 1883 was measured by gis, and the volume of fine sediment was calculated as a product of area and thickness. the volume of fine sediment accumulated within the channel bed of 1883 was calculated for each reach, and it was then used to get an estimation of the volumes of contaminants stocked within these mus. 2.2. geochemical sampling and analysis a total of 102 samples of sediments were collected, including 82 samples from the transects along the paglia river, 7 samples from the siele transect, and 13 samples outside the studied transects from presumably pre-mining deposits (see below), to establish a comparison between preand post-mining conditions. following preliminary tests, it was ascertained that the <250 μm fraction likely contains nearly all hg of the bulk sample; this fraction was digested with aqua regia in a microwave oven, and the resulting solution was analysed by means of icp-oes. 3. results 3.1. channel and floodplain evolution considering channel widths of the three reference years in this study (1883, 1954, 2012), it appears that the paglia river suffered significant channel narrowing 64 fig. 1 geology of the upper part of the paglia river catchment (delimited by a white line) after colica (2017). the analyzed paglia river stretch is between the points with stars. landscape units (lus; their limits are highlighted with a black line): 1lu) mountain areas with volcanic and volcano-sedimentary successions and ligurian and subligurian units; 2lu) hilly areas with neogene deposits and continental deposits complex; 3lu) mainly hilly areas with ligurian and subligurian units and volcanic and volcano-sedimentary successions; 4lu) intermontane plain unit with neogene deposits and continental deposits complex. the transects are indicated by red segments and numbers. the black points indicate the beginning of the reaches along the paglia river (same numbers of transects). siele is the transect along the siele creek. the capital red letters indicate the mining areas: a) abbadia san salvatore; b) casa di paolo senna mine cerro del tasca; c) siele carpine; d) cornacchino. regional boundaries are reported in yellow. colica a. et al. 65 over time, with an average reduction in channel width of about 64% between 1883 and 1954, and a further reduction of about 70% between 1954 and 2012. channel narrowing occurred in combination with a change in the overall morphological pattern, from a braided (1883) to a single-thread, sinuous morphology (2012). the causes of these changes are a combination of land use changes (i.e., afforestation) at catchment scale with intensive sediment mining (see e.g. scorpio & rosskopf, 2016). 3.2. geomorphic characterization and interpretation of sampling transects a sequence of terraces was generated by bed incision and narrowing (fig. 2): old terrace (t1) (i.e. formed before the last 150 years), corresponding to an alluvial surface that is already recognized as higher than the floodplain in the maps of 1883; recent terrace (t2), interpreted as the modern floodplain in the maps of 1883, corresponding to the alluvial flat surface adjacent to the channel bed of 1883; recent terrace (t3), formed between 1883 and 1954, corresponding to a flat surface at an intermediate elevation between t2 and t4, interpreted as a recent terrace in the aerial photos of 1954; recent terrace (t4), formed after 1954, corresponding to the modern floodplain recognized in the aerial photos of 1954; recent terrace (t5), formed between 1954 and 2012, corresponding to a flat surface at an intermediate elevation between t4 and the modern floodplain (fp). the fp is the lowest flat and vegetated surface adjacent to the river bed, recognized in the aerial photos of 2012 and during the field survey as the channel bars (b) and baseflow channel (c). as can be seen in fig. 2, some mus that are present within the 1883 channel bed were formed during mamd mining activity: t3 during the initial phase, t4 during the maximum period of activity (1950s-60s), t5 during the final and closing stages (1980s) and possibly also after (but before 2012). 3.3. geochemical data fig. 3 reports the hg concentration in the mus in the transects along the paglia river. samples from premining deposits are characterized by hg concentrations comparable with the background estimate of the amiata area (2-6 mg/kg; rimondi et al., 2015). by contrast, many samples in all other mus show hg contents well above this background and above the italian legal limit of 5 mg/kg (dl 152/2006) for industrial soil. in particular, high values of hg concentration are shown in the following mus: t4 (hg> 30 mg/kg along transects 2.2, 2.5 and 2.6), fp (> 30 mg/kg along transects 2.2 and 2.3) and c (> 20 mg/kg along transects 2.6 and 2.7). the highest mean hg value was observed in recent t4 terraces. the highest values of hg concentration per mus were found along the siele transect: c (29.4 mg/kg), b (mean value 79.2 mg/kg), fp (mean value 183.7 mg/kg) and t4 (mean value 92 mg/kg). 3.4. total hg masses from the volumes of river sediments accumulated in the reaches and hg concentrations, we estimate a total bulk value of 63 tonnes of hg in the studied stretch (colica et al., 2016). the highest contents are found in t4 (39 tonnes), followed by fp (19 tonnes), t3 (4 tonnes) and t5 (1 tonne). considering the single reaches, reach 3.1 shows the largest amount of hg (25 tonnes), followed by reaches 2.3 (12 tonnes), 2.5 (10 tonnes) and 2.6, 2.7 and 4.1 (each containing 4 tonnes of hg). 3.5. the major flood event of february 2016 at the end of february 2016, a major flood event along the paglia r. caused the deposition of overbank deposits on top of pre-existing mus. these deposits have hg values in the 5-40 mg/kg range (stars in fig. 3) and a mean value of 21 mg/kg, similar to that of the fp (19 mg/kg). comparing these data with those collected from the major flood of november 2012 (pattelli et al., 2014; circles in fig. 3), it is evident that large quantities of hg-contaminated sediments have been transported during major flood events. specifically, the hg concentration in transect 2.2 is about four times higher in the 2016 event compared to that of 2012. 4. discussion on the basis of the geomorphologic-geochemical analysis, it can be stated that current and recent mus in the paglia river basin are locally heavily contaminated by hg. in particular, the most contaminated mu t4 was formed during the peak of the mamd mining activity. on the other hand, the high hg values of fps could be due both to the last flood events, which deposited abundant amounts of sediment and contaminated materials along the river banks, and to the recent local partial enlargement of some reaches of the paglia river. the t3 unit was presumably formed around the beginning of the mamd mining activity and immediately prior to the peak activity period. in this mu hg content is less than the two previous cases, but the total hg bulk is about 4 times higher than in t5; this last unit, formed after 1954 and before 2012, contains sediment with low hg content, probably as a result of the closure of the mining activities in the 1980s. it is important to highlight how the erosion of some mus can result in a high environmental risk due to their high mass of contaminants. it should also be noted that the eventual securing of these mus areas must take into fig. 2 range and mean values of hg concentrations (mg/kg) in the different mus along the paglia river, modified from colica (2017) hg dispersion from amiata mining district to paglia river account that in every major flood event large quantities of heavy hg contaminated sediments might be transported and redeposited on the pre-existing mus. the influence of the paglia river tributaries appears to be fundamental in the supply of hgcontaminated sediments (fig. 3). in particular, the pagliola creek drains the mining area of abbadia san salvatore and, despite the ongoing reclamation in this area, it carries high hg concentrations in fluvial sediments during flood events (e.g., fp of transect 2.2 contains 98 mg/kg hg). indeed, the deposits of the baseflow channel (c) and bar (b) sampled during a period without intense floods (2013-2014) show hg contents less than 1 mg/kg. the presence of high hg values in recent t4 terraces (fig. 3; transect 2.2) may also be due to the presence of more contaminated sediments in the 1954 fp, following the period of maximum activity in the abbadia san salvatore mining area. the siele creek drains the siele-carpine mining area. although reclamation was completed in 2001, the siele transect shows the highest hg concentrations in various mus (e.g., samples c, b, fp and t4). the contribution of highly polluted sediments from the siele creek to the paglia river is clearly recorded in the hg contents of c and b from transect 2.6 (fig. 3). this phenomenon also occurred during the formation of recent and past fps (e.g., hg values in t4 terraces). the presence of high hg concentration in t4 at transect 2.5 (fig. 3) is due to the 1954 local existence of an extended fp in which hg-contaminated river sediments could accumulate more easily. 5. conclusions based on the above geomorphologic-geochemical approach, variable, locally elevated hg concentrations in the paglia river sediments, belonging to the various mus, were found in both the transects and along the watercourse. the total mass of hg in the different mus also varies considerably. this variability is conditioned both by past and current fluvial dynamics and, until the 1980s, by mamd activity, whose effects are still affecting the fluvial environment. the total mass of hg in mus of the analysed paglia river stretch (43 km) is estimated to at least 63 tonnes. during major flood events, the paglia river appears to carry sediments with high concentrations of hg. the tributaries of paglia river contribute to this process, in particular the pagliola creek, which drains the mining area of abbadia san salvatore, and the siele creek, which drains the sielecarpine mining area. this latter creek carries sediments with the highest concentrations of hg in all current flow conditions. the course of the paglia river has undergone and is undergoing strong fluvial dynamics; particularly, since 1883 there has been a gradual incision. the most recent mus can be eroded, and thus become secondary sources of contamination. however, a recent reversal fluvial trend, a partial enlargement of some reaches, was locally observed. where this last phenomenon occurs, there are favorable conditions for a greater accumulation of contaminated sediments. knowledge of paglia river dynamics and of its current and past mus is crucial for identifying areas with greater environmental risk. the survey methodology that com 66 colica a. et al. fig. 3 hg concentrations in mus along the paglia river transects with locations of the tributaries after colica (2017). the italian legal limit (5 mg/kg; dl 152/2006) for hg in industrial soil is reported. the values are the mean of the hg concentration in the two banks. hg concentrations in the overbank deposits after the major flood events of february 2016 (stars) and november 2012 (circles) are here reported. bines geomorphologic and geochemical aspects is apparently a very effective tool for identifying these mus, understanding current and potential environmental hazards and conducting future monitoring that may have relevance for restoration measures of the affected matrices. references benvenuti m., costagliola p. (2016) il distretto mercurifero del comprensorio amiatino: nuovi dati sull’impatto ambientale nel sistema fluviale pagliatevere. geol. ambiente, xxiv, (4), 2-5. belletti b., rinaldi m., bussettini m., comiti f., gurnell a.m., mao l., nardi l., vezza p. (2016) characterising physical habitats and fluvial hydromorphology a new system for the survey and classification of river geomorphic units. geomorphology, 283, 143-157. colica a., chiarantini l., rimondi v., benvenuti m., costagliola p., lattanzi p., paolieri m., rinaldi m. (2016) toxic metal dispersion in mining areas: from point source to diffusion pollution. the case of the mt. amiata hg mining district (southern tuscany italy) new results. geophysical research abstracts egu2016-9049-2, 18. colica a. (2017) innovative methodologies for erosion risk analysis in areas contaminated by industrial activity. application at amiatin mineral district (southern tuscany). plinius, 43, 26-36. gurnell a.m., belletti b., bizzi s., blamauer b., braca g., buijse a.d., bussettini m., camenen b., comiti f., demarchi l., garcia de jalon d., gonzalez del tanago m., grabowski r.c., gunn i.d.m., habersack h., hendriks d., henshaw, a., klosch m., lastoria b., latapie a., marcinkowski p., martinez-fernandez v., mosselman e., mountford j.o., nardi l., okruszko t., o’hare m.t., palma m., percopo c., rinaldi m., surian n., van de bund w., weissteiner c., ziliani l. (2016) a multi -scale hierarchical framework for developing understanding of river behaviour. aquat. sci., 78, 116. marroni m., moratti g., costantini a., conticelli s., benvenuti m. g., pandolfi l., bonini m., cornamusini g., laurenzi m. a. (2015) geology of the monte amiata region, southern tuscany, central italy. ital. j. geosci., 134, 171-199. pattelli g., rimondi v., benvenuti m., chiarantini l., colica a., costagliola p., di benedetto f., lattanzi p., paolieri m., rinaldi m. (2014) effects of the november 2012 flood event on the mobilization of hg from the mount amiata mining district to the sediments of the paglia river basin. minerals, 4, 241-256. rimondi v., chiarantini l., lattanzi p., benvenuti m., beutel m., colica a., costagliola p., di benedetto f., gabbani g., gray j. e., pandeli e., pattelli g., paolieri m., ruggieri g. (2015) metallogeny, exploitation and environmental impact of mt. amiat mercury ore discrict (suouthern tuscany, italy). ital. j. geosci., 134 (2), 323-336. rinaldi m., gurnell a.m., gonzalez del tanago m., bussettini m., hendriks d. (2016) classification of river morphology and hydrology to support management and restoration. aquat. sci., 78, 17-33. rinaldi m., surian n., comiti f., bussettini m. (2013) a method for the assessment and analysis of the hydromorphological condition of italian streams: the morphological quality index (mqi). geomorphology, 180-181, 96-108. scorpio v., rosskopf c.m. (2016) channel adjustments in a mediterranean river over the last 150 years in the context of anthropic and natural controls. geomorphology, 275, 90-104. 67 hg dispersion from amiata mining district to paglia river ms. received: may 1, 2018 final text received: may 18, 2018 68 available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 34 (1), 2021, 89-108 paleoecological first results from the middle pleistocene sequence of coudoulous i (quercy, lot, france). philippe fernandez 1 , marcel jeannet † 1 , jacques jaubert 2 , jean-philip brugal 1 1 cnrs, umr 7269 lampea, aix marseille université, cnrs, minist. culture, aix-en-provence, france. 2 university of bordeaux, cnrs-mc, umr 5199 pacea, pessac, france. corresponding author: philippe fernandez <philippe.fernandez@univ-amu.fr> and jean-philip brugal <brugal@mmsh.univ-aix.fr> abstract: the coudoulous i (lot, france) sequence has yielded abundant fossil associations dated to the end of the middle pleistocene. the total sample consists of 102 taxa corresponding to 75 species of mammals (53 small and 22 large mammals), 11 species of amphibians and 16 species of reptiles distributed in five faunal units (fus). after evaluating the sample quality with completeness indices (ci and cibda), we established rarefaction curves that were discussed at length together with shannonwiener diversity (h’), margalef species richness (d), and the sørensen-dice similarity index. in order to better understand structural changes in the mammal associations as well as the climate trends we built the body mass distribution with cenograms in the different fus. concurrently, we investigated the whole community using a more analytical approach with the “bioclimatic model” based on a climatic restriction index for each species to infer paleoclimatic proxies (i.e. temperatures, precipitation, aridity) and finally to assign each faunal unit to a dominant type of climate. our results clearly indicate that the fus could be systematically associated with a typical temperate climate with sub-mediterranean temperate species for the largest part of the sequence, which is consistent with the dates obtained (u/th, esr/u-series, tt-osl) and marine isotope stage 7. nevertheless, cold elements from a boreal type climate component were also found in the sequence indicating possible climate oscillations in fus. the upper part of the stratigraphy (fuii) is probably related to mis 6 while the lowest part of the sequence (fuvii) could correspond to a cold phase of the mis 7 or earlier (mis 8?). keywords: vertebrate community, diversity, cenograms, bioclimatic model, climate reconstruction, mis 6-7. 1. introduction less than a dozen sites in the french mediterranean region are dated to the middle pleistocene, and perhaps only twenty in southern france (see fig. 2 in brugal et al., 2020). among them, the coudoulous sites show one of the most well-constrained chronostratigraphical sequences, yielding very rich and diversified fossil vertebrate and invertebrate associations (jaubert et al., 2005). the quercy region, where coudoulous is situated, exhibits numerous and varied archeological and/or paleontological sites covering the last 0.3 myr within a wide range of environmental and climatic contexts (jaubert et al., 2013; jeannet et al., 2013; brugal et al., 2013). this region is located at the periphery of the mediterranean ecological area, subject to the atlantic conditions of the aquitaine basin and bordered by the low mountainous area of the massif central. we propose in this contribution to depict the succession of fossil associations throughout the complete sequence of coudoulous i, attributed to the end of the middle pleistocene, with the aimof characterizing paleoecological and climatic dynamics. 2. the coudoulous sites the coudoulous (coud) sites are located in the quercy area (44°28'40"n, 1°39'50"e), not far from the paleolithic cave art site of pech-merle (cabrerets), a region of small jurassic limestone plateaus divided by more or less narrow valleys and rivers. these sites are in a high position (280m asl) at the junction of the river lot and its tributary, the célé (fig. 1), and correspond to two distinct karstic cavities, namely coud i and coud ii. first explored with a rescue excavation in 1978-1980 (bonifay & clottes, 1981; jaubert, 1984), the sites were investigated between 1994 and 2003 by j. jaubert (for coud i) (jaubert et al., 2005) and j.p. brugal (for coud https://doi.org/10.26382/amq.2021.12 90 fernandez p. et al. into 4 main units/formations but only the lower and middle units yield lithic artefact and fossil remains (fig. 2). several levels (from 3 at the top to 8 at the bottom) and sub-levels (at least 31) are distinguished within these units. the sequence is bracketed by two speleothems dated by u/th (fig. 2): the upper one (between levels 2 and 3) is assigned to mis 5 (126[+20/-46] and 139[+13/11] kyr) and, the thick basal one (level 8g-e) at the limit of the method (229[+78/-42] and 202[+78/-39] kyr) is less accurate (quinif in jaubert et al., 2005; couchoud, 2006). two other stalagmitic floors are observed in the sequence (respectively levels 8a and 8c) and all are important periods of sedimentation with a pause in fossil ii) (brugal et al., 1998; costamagno, 1999; brugal, 2006). here we focus on the coudoulous i site, with a brief overview and synthesis of the different studies made of this site and its chronological sequence. 2.1. the coudoulous i sequence the karstic cavity represents a pitfall (aven), with a main vertical entrance after the collapse of the roof above a large room (15-20 m diameter) presently completely filled with detrital (clays, sands, angular limestone rocks) or carbonate (speleothems) deposits, to a total of ca.10 m in thickness (jaubert et al., 2005). the sequence is divided into 10 stratigraphic layers grouped fig. 1 location of coudoulous sites. photo j. jaubert and map reworked from electronic reference (18). fig. 2 coudoulous i, from left to right: photo of the geological units (black arrow=2 m); stratigraphic log with datations (grey bar=speleothems); faunal units; distribution of non-identifiable bone remains (n total=80.452) throughout levels 5 to 8. 91 paleoecologial first results from the middle pleistocene sequence of coudoulous i (quercy, lot, france). deposition, and should be considered as natural limits or cut-offs. the sequence has been dated by u/th, esr/u-series and tt-osl on teeth and bone and sedimentary quartz samples (hernandez et al., 2015) giving correlations from mis 7 to mis 6. a very rich archaeological level (level 4) occurs at the top of the coudoulous i sequence, and the levels (3 to 1) above it are sterile. level 4 yielded abundant lithic artefacts (flint, quartzite), with levallois core reduction, reported as early middle paleolithic (emp: stage 6.5) (jaubert, 1995; mourre, 1996), associated with a dominant species, the bison (98%), with very few horse and wolf remains. the bison record includes a minimum of 232 individuals, represented by all skeletal parts, but strongly affected by taphonomic processes, which have preferentially removed axial and cephalic bone elements. teeth are good zooarchaeological and paleoclimatic indicators and demonstrate a catastrophic mortality pattern (juveniles and young adults dominant) and a late spring-early summer seasonality (brugal, 1999a, 1999b; brugal & jaubert, 2006; hélène martin, pers. comm.). oxygen isotope analysis of phosphate in tooth enamel (δ 18op) shows contrasted seasons with a minimal annual temperature of 9±3 °c, which is about 4 °c lower than at present (bernard et al., 2009). emp or lower paleolithic artefacts are scarce and dispersed in the middle to lower units (levels 5a to 8d), and made on quartz, quartzite, metamorphic and volcanic rocks. the techno-typological analysis places this industry within the variability of the acheulean despite the absence of typically bifacial tools, but with some large cutting tools (lcts) present (jaubert, 1995; jaubert & servelle, 1996). an interdisciplinary study has demonstrated that the cavity was used for marginal scavenging by lower paleolithic hominid groups and as a kill-butchery site during the emp (brugal & jaubert, 1991, 2021; jaubert et al., 2005). 2.2. material this contribution is the first paleoecological analysis of the vertebrate associations from the middle and lower units (levels 5 to 8) of coudoulous i (fig. 2). this site represents one of the rare stratigraphic sequences of the middle pleistocene yielding a very rich and diversified fauna (nisp=9864). moreover, a total of more than 80 000 splinters and bone shaft fragments (nonidentifiable remains) were also collected during the excavations. following geological and stratigraphical observations (kervazo et al., 2021) and the distribution and abundance of faunal remains (brugal, 2021), 6 faunal units (fu) were identified. according the stratigraphic log in fig. 2, fui includes only level 4. fuii and fuiii correspond to the middle units, with levels 5 and 6a to 7b, respectively. the two lower speleothems are used as limits in the distinction of the subsequent fus (fuiv+v to fuvii). fuiv+v have been regrouped here and correspond to level 7c to 7f’. fuvi includes levels 8a to 8c and fuvii corresponds to level 8d. for the paleoecological purposes of this study the taxonomic determinations were realized at species level in five faunal units (fuii, fuiii, fuiv+v, fuvi, fuvii) thanks to detailed studies (jeannet, 2021, for microvertebrates; argant, 2021, for felids and ursids; mallye, 2021, for mustelids; boudadi-maligne, 2021, for canids) and our own studies (equids, bovids, caprids, cervids, rhinocerotids, proboscids). the remains with marking errors or that might have been shuffled between different stratigraphic levels were not included. we took into account 9864 number of identified specimens (nisp) from 102 species including small mammals such as rodents (n=35), lagomorphs (n=4), and chiropters (n=14), but also large mammals including ungulates (n=10) and carnivores from small to medium size (n=12), and respectively 16 and 11 species of reptiles and amphibians (tab. 1). 3. methods ever since the work of leonard and jones (1989) concerning the concept of “diversity”, methodological and theoretical approaches have continued to be topical in paleobiological contexts for studying animal communities (rarefaction, richness, sample size, sample unit of measurement, appropriate diversity indices, etc.). here we present the paleoecological analysis of the coudoulous i mammals, applying and sometimes crossreferencing different methods (concept, mathematical formulations, limits) to see if they lead to similar results in the different faunal units of this site. 3.1. completeness indices (ci) and (ci bda) natural taphonomic processes as well as carnivore activity and anthropogenic modifications are the key factors that explain biased samples from original deposits. nevertheless, completeness indices (ci) and (cibda) (maas & krause, 1994; maas et al., 1995) make it possible to evaluate the quality of the sample in the faunal units, starting with the presence (1) absence (0) of species (palombo et al., 2008). completeness indices are based on the assumption of the range-through of the species represented, meaning that a given species, which is present before and after, but not during an interval of time is supposed to have been in continuous existence from its first to last appearance in the stratigraphy. in this particular case, missing species probably result from taphonomic bias, poor sampling or bad preservation of the fossil remains. it should be added that between their first and last appearances, some missing species could have diffused to new landscapes or different habitats in response to strong climate changes. the completeness indices ci and cibda are calculated as follows (see details in maas et al., 1995; palombo et al., 2008; fernandez, 2009): eq. (1) ci = [nt / (nt + nrt)]*100 eq. (2) cibda = [nbda/(nbda+nrt)]*100 nt is the number of species known before, during and after the faunal unit considered, including taxa having their first or last occurrences in the interval. nrt is the number of species known before and after, but not during the faunal unit interval. to calculate nrt in the last and the first faunal units respectively fuii and fuvii, we used species’ chronological extension 92 fernandez p. et al. paleoecologial first results from the middle pleistocene sequence of coudoulous i (quercy, lot, france). 93 from the works of palombo et al. (2008) as well as fernandez (2009). because nbda is the number of species only known before, during and after a faunal unit interval, cibda excludes the first and last fu whereas ci allows us to take into account all of the faunal units (maas et al., 1995; palombo et al., 2008). 3.2. rarefaction, richness (s), margalef (d), shannon -wiener (h’) and the sørensen-dice index in this study we used the rarefaction method that was popularized by sanders (1968) for marine invertebrate communities and which has became a standard method. when applying sanders's algorithm key assumptions (all met in coudoulous i) are required such as a similar taxonomical rank between individuals collected from a similar place by using standardised procedures (tipper, 1979). the brilliant idea of sanders makes it possible to compare the number of species from different assemblages independently of the size of the initial samples and to see to what extent the sampling can induce a bias in the species richness (s) (i.e. area sampled, non-standardized sampling, catchability, etc.) (raup, 1975; tipper, 1979; ricklefs & miller, 1999; gotelli & colwell, 2001). given the strong correlation between the number of identified specimens (nisp) and the minimum number of individuals (mni) put forward by grayson (1984) and later by lyman (2008), rarefaction has been used in different paleobiological contexts, whether natural or anthropogenic (e.g. adrain et al., 2000; belmaker, 2006; belmaker & hovers, 2011; popov & marinska, 2007; davis & pyenson, 2007; fernandez, 2009). in coudoulous i we established rarefaction curves for each faunal unit from all the taxa present in the sequence and determined by the rank of the species (s=102). these curves were built with the "individualbased rarefaction" routine of the past program (version 3.23) (hammer et al., 2001; hammer & harper, 2006, see equations 6.10 to 6.13, p. 205). in addition to rarefaction, we used species diversity which measures species richness combined with evenness, taking into account not only how many species are present but also how evenly distributed the numbers of each species are (see eq. 3). it has been demonstrated that diversity varies consistently according to largescale geographical areas with δ and δ diversity (rohde, 1992) but also in more restricted areas or habitats at a more local scale (δ diversity, whittaker, 1972). thus, there are many different indices and mathematical solutions to account for the diversity that can be defined in many ways (hammer et harper, 2006). these authors indicate that only the number of individuals should be used to estimate the diversity of a community. consequently, in nearly all paleobiological contexts diversity indices will always be an approximation because mni will never be the real number of individuals. as a result of the foregoing and the fact that we used nisp, which is strongly correlated to mni, we focused on the shannon-wiener diversity index (shannon & weaver, 1964) as it takes into account proportions for the frequency and it is completely adapted for local area (δ , the within assemblage diversity). we would like to stress that this index is sometimes erroneously labelled as the “shannon-weaver” index (see spellerberg & fedor, 2003 for this confusion). the formula implemented in past (version 3.23) that we used is as follows: eq. (3) h’ = -∑pi ln pi where (ln) is the logarithm to the base of e (sometime in the literature base two is used), and where pi is the proportion of individuals that belong to species i. because species richness (s) increases with sample size, we used margalef’s species richness index (d) that attempts to compensate for this effect, as defined by the formula (margalef, 1958): eq. (4) d = (s-1) / ln n to go further in the analysis, we calculated the sørensen-dice index, which is a statistical indicator that measures the similarity between two samples and was developed independently in botany by dice (1945) and sørensen (1948). the sørensen-dice formula is as follows: eq. (5) sørensen-dice = 2j / (a+b) a and b represent the number of species in each sample and j the number of species common to the samples a and b. it is indexed from 0, a total absence of common elements, to 1 when two samples are identical (see fig. 3). we do not go into further detail because the similarity coefficients are numerous and can only be explained by mathematical demonstrations (shi, 1993). comparing them to the most widely used such as simpson’s (1943) and jaccard’s coefficients (1912), here we have chosen to put more weight on matches than on mismatches due to the multiplication of j by a factor of two (see eq. 5). furthermore, the sørensen-dice coefficient normalizes with respect to the average rather than the total number of species in the two samples. consequently, it is somewhat less sensitive to differences in sample size than jaccard’s index. the sørensen-dice index is also different from simpson’s coefficient, which is totally insensitive to the size of the larger sample and also does not take into account absences in the smaller sample of comparison (hammer & harper, 2006). 3.3. body mass and cenograms the cenograms was proposed by valverde (1964, 1967) in order to compare body size of non carnivore modern terrestrial mammals from different communities. given that the weight distributions of species are strongly dependent on their environmental conditions in predictable ways, legendre (1986, 1989) and gingerich (1989) extended the method into the fossil record to infer different paleoenvironmental characteristics as climatic < < < < < tab. 1 faunal units fuii to fuvii with species richness (s), number of identified specimens (nisp). for each species, log (ln) is given according to their body mass (see bibliographic references including electronic references). completeness indices (ci and cibda) are calculated from eq. 1 & eq. 2 in text. for predator prey ratio (ppr=n predator /n prey) see details in text. changes, namely, humidity or aridity, and types of landscapes, mainly open or closed. although the initial work of legendre was controversial on quantitative aspects (see rodríguez, 1999) other quaternary european paleoenvironmental studies have used the cenogram method (montuire, 1994, 1999; rodríguez et al., 1996; montuire & desclaux, 1997; montuire & marcolini, 2001; valensi & psathi, 2004; hernández fernández et al., 2006; palombo & giovinazzo, 2006; fernandez, 2009). the initial graphic representation established by legendre (1986) reports the body mass (ln on the yaxis) according to the rank of the species (on the x-axis from the heaviest to the lightest). schematically, the plots of points are represented by segments with different slopes (sometimes built by linear regression) and separated by breaks/gaps in the slope (see climatic trends in fig. 4). legendre’s model (1986, 1989) and gingerich (1989) who quantified the slopes, gaps and breakpoints, took into account small-sized (500 g<), medium-sized (500 g> 250 kg<) and large-sized mammals (> 250 kg) with two breakpoints around 8 kg and 250 kg. there is a gap (500 g 8 kg) with greater (steeper) slope for medium-sized species in an open environment (e.g. woodlands and savannas) whereas closed environments have a continuous distribution. in a typical humid environment the breakpoint around 250 kg marks the low regression slope for medium-sized species, with no break for closed landscapes and a gap around 500 g for a more open environment. gingerich (1989) hypothesized that the relative scarcity of mammals of about 500 g in this type of environment is probably related to the range of size, the density, and the diversity of insects and leaves, both of which are greatest in forests. 3.4. predator prey ratio (ppr) the ppr is simply the ratio between the number of predators and prey (ppr=n species of predators / n species of prey). for many pleistocene sites, significant changes in ppr are difficult to interpret. raia et al. (2007) found evidence for ppr inconstancy through time such as had been pointed out in previous studies (i.e. van valkenburgh & janis, 1993). here we assume an actualist approach whereby carnivores weighing up 21.5 kg feed mostly on prey that is 45% or less of their own mass (carbone et al., 1999). because carnivores above this limit feed mostly on prey that are greater than 45% of their own mass, we excluded from our calculation the mustelids of the sequence as well as meles meles, vulpes vulpes and felis silvestris. 3.5. bioclimatic analysis a reconstruction of the climate and the plant environment has been inferred for each coudoulous i faunal unit from the so-called “bioclimatic model” developed by hernández-fernández (2001a, 2001b) and hernándezfernández & peláez-campomanes (2003, 2005). it has been very recently used on archaeological sites from the middle pleistocene with human remains (lopezgarcia et al., 2021), and adapted for insectivore and rodent communities from the last glacial maximum to the holocene (royer et al., 2020). in the initial work of hernández-fernández (2001a, 2001b), 50 associations of present-day mammals were compiled in different latitudes and biotopes corresponding to 10 major bioclimatic components (bc) associated with different types of climates (tab. 2). a typology adapted from previous works (walter, 1970; rivas-martínez, 1994) made it possible to systematically identify different environmental variables for each bc (e.g. type of vegetation, average annual temperatures, rain rate, thermal amplitude…). thus, each mammalian species is associated with a crii (climatic restriction index) value ranging from 0 to 1 which characterizes its climate dependence such that: eq. (6) crii = 1/n with n the number of bcs where the species are represented and i the bc where the species appear. for the distribution of species by climatic types we used the work of hernández-fernández et al. (2007) and jeannet (2010, 2021) for microfauna. for large mammals, and in rare cases their nearest living ecological analog species, we used the studies of bhatnagar & lovari (2008), palombo (2015) and lovari et al. (2016a, 2016b). for example, in table 3, according to the data from hernández-fernández, (2001a, appendix 2), the crii value is equal to 1 for ochotona pusilla, in bc vii, which means that all elements of this species are exclusively associated with this arid-temperate climate. on the other hand, the crii of 0.33 for microtus oeconomus, which is associated with bioclimatic components vi, viii and ix, indicates that this species is more eurioic than the previous one. it is therefore possible to calculate for several mammalian species a probability of association (bc) for each of the 10 bioclimatic components according to the following formula: 94 fernandez p. et al. tab. 2 bioclimatic components (bc) according to their type of climate and vegetation cover (from hernàndez-fernàndez, 2001a, table 2.1). paleoecologial first results from the middle pleistocene sequence of coudoulous i (quercy, lot, france). 95 tab. 3 distribution of the mammalian species identified in fuii according to their climatic restriction index (crii, see detailed eq. 6 in text) and bioclimatic component (bci, see detailed eq. 7 in text) in accordance with hernàndez-fernàndez (2001a) for the crii. eq. (7) bci = (∑ crii)*100/s (s) being the number of species present in the faunal association (or species richness). note also that the bci value is equivalent to the cumulative rates of andrews (1990) or to the % thi of fernández-jalvo et al. (1998). to end with our example, in table 4, the highest probability bci of the ufii mammalian association corresponds to bc vi (aridtemperate climate) with 36.45%, followed by bc viii with a probability of 18.66%, and so on. for each fu, we reported mammalian associations and their most likely bc (tab. 4). to go deeper into the climate reconstructions, in this table we calculated some paleoclimatic proxies from the bci values (eq. 7) using the multiple linear regression coefficients from hernández-fernández (2001a, table 4.1 to 4.3). these indices and the parameters of their equations (b=intercept, a1 to a9=regression coefficients) are presented in the table 5 with the following components: mean annual temperature (°c) (mat). mean annual thermal amplitude (°c) (mata). this expresses the difference (°c) between the mean temperature of the warmest month and that of the coldest month of the year. according rivas-martínez (1994), it is an index of continentality simple. annual positive temperatures index (apti). this provides a measure of the intensity of the summer heat. compensated thermal index (cti). in extratropical zones, the cti is designed to equilibrate the cold “excess” that occurs during winter in the continental climates (average temperature of the coldest month of the year minimum), or the excessively mild winter in the marked oceanic territories, so that these index values can be significantly compared (rivas-martínez et al., 2011). mean annual precipitation (mm) (map) mean temperatures of the coldest month (°c) (mtcm) aridity index (ai). we calculated this index from de martonne (1926) which is still used with good results (pellicone et al., 2019). it is simply the ratio between the mean annual precipitation (mm) (map) and the mean annual temperature (°c) (mat) weighted by 10 such that: (ai) = map / mat + 10. this index should be read carefully because the higher the ai, the lower the aridity. 4. results and discussion 4.1. sample quality in coudoulous i, ci indicates a low-quality sample for fuii (52.88) and fuvii (28.43) whereas cibda corresponds to a very slightly modified sample in fuiii, fuiv+v and fuvi respectively with 81.25, 91.66 and 92.85 (tab. 1). an index value higher than 70 usually reflects very little disturbance in a faunal unit interval (maas et al., 1995; palombo et al., 2008). biases are often related to lower values in shorter chronological intervals, which is clearly the case in fuvii with only one archaeological level (8d). the ci of this faunal unit (28.43) reflects the lowest quality sample in the whole sequence. on the other hand, the overlying fuvi shows a very high cibda index (92.85). fuiv+v (cibda=91.66) and fuiii (cibda=81.25) also both indicate very good quality samples mainly associated to the subdivisions of level 7, probably contemporary with mis 7, which is supported by biomarkers (mammal species and/or evolutive stage) and absolute dates (e.g. jaubert et al., 2005, 2013; boudadi-maligne, 2010; hernandez et al., 2015). finally, in the most recent fuii ci=52.88 indicates a poorquality sample. this faunal unit, beneath level 4, is related to the first part of mis 6 (jaubert et al., 2005; hernandez et al., 2015), a glacial period known for involving dramatic drops in temperature (mokeddem & mcmanus, 2016). the relatively low species richness of this faunal unit might coincide with this climate cooling. 4.2. diversity (s.l.) in coudoulous i, rarefaction curves illustrate the expected number of species whatever the initial sample size in each faunal unit (fig. 3). the number of rarefied species in fuiv+v is higher than in the lower fuiii, fuvi, fuii and fuvii, respectively. in the same way the decreasing values of the margalef index (d) are totally in line with the rarefaction curves. although the calculations are quite different, both rarefaction and the margalef index (d) reach the same result. the latter also compensates for the sample size effect by dividing the number of species in a sample by the natural log of the number of individuals (see eq. 4). furthermore, the curve from fuvii does not reach the asymptotic plateau, indicating a significant bias in this sample (lowest ci), also shown by the weakness of the nisp and the species richness (nisp=118 and s=29) which correspond to the single archaeological level 8d. interestingly enough, the species-rich communities may have a greater number of trophic levels than species-poor communities (briand, 1983). it is in light of this evidence that yachi & loreau (1999) formulated the “insurance hypothesis” stating that high species rich 96 fernandez p. et al. tab. 4 coudoulous i faunal units and their probabilities (p1 to p3) of association with a bioclimatic component (see table 2 for bc description). (s), species richness (excluding reptiles and amphibians). paleoclimatic proxies with mean average t° (mat), mean annual thermal amplitude (mata), annual positive temperatures index (apti), compensated thermal index (cti), mean annual precipitations (map), mean temperatures of the coldest month (mtcm), aridity index (ai) (see text for details). calculation for some paleoclimatic proxies from multiple linear regression coefficients provided in table 5. tab. 5 paleoclimatic proxies with equation parameters (b=intercept, a1 to a9 = regression coefficients) from hernández-fernández (2001a, table 4.1 to 4.3) (see details in text). paleoecologial first results from the middle pleistocene sequence of coudoulous i (quercy, lot, france). 97 ness increases community stability with species that respond differently to environmental fluctuations (see also ives et al., 2000). if we accept this hypothesis, the rarefaction curves associated with the highest margalef indices could be good indicators of a stable community in coudoulous i (respectively fuiv+v, fuiii, fuvi, fuii, fuvii). in figure 3, the shannon-wiener diversity index (h’) values are almost correlated to the species richness (s) and margalef’s values (d). nevertheless, in fuvii the diversity is higher with h’=2.77 whereas the number of species is much less important (n=29) than in fuii (n=53) which has the lowest diversity h’=2.06. it means that independently of both species richness and the lowest ci (discussed above), the shannonwiener index is very sensitive to the individual distribution frequency among species in fuvii. in all faunal units the h’ values are comprised between 2.06 and 3.08. it is difficult to compare these values with other sites, knowing that diversity is strongly dependant on multiple local factors (e.g. climate, taxonomical groups, ecosystem involved, etc.). nevertheless, it is now widely accepted that high species diversity indicates a highly complex community with more species interactions (whittaker, 1972). it is worth noting that in nature, whatever the taxonomic group studied, h’ often ranges between 1.5 and 3.5 according to gaines et al. (1999). another important consideration that should be emphasized is that h’ as well as d are completely independent of the temporal gradient in the different fus whereas the sørensen-dice index almost always shows a greater similarity between the closest fus through time. in other words, the more distant the fus are, the less species they have in common. this should not be considered as a statistical artefact but most likely as a gradual turnover of species through time, probably due to paleoenvironmental changes. in southern africa, andrews & o’brien (2000), combining 15 climatic variables with current mammal species (n=285), showed that woody plant species (n=1359) alone explained 75% of the variability in mammal species richness. nevertheless, large mammals over 90 kg, scansorial, aquatic or fossorial mammals were not significantly correlated with woody plant species richness, unlike small-bodied arboreal frugivores and insectivores. this led us to test which species were most affected by possible climate and plant cover changes in the different faunal units of coudoulous i. therefore, we fig. 3 rarefaction curves, shannon-wiener diversity (h’), margalef species richness (d) and sørensen-dice similarity for each faunal unit (fuii to fuvii). nisp in table 1 is used for calculation with past 3.23, (hammer et al., 2001). for rarefaction see details in text for “individual-based rarefaction" routine from past. for calculation of shannon-wiener (h’) see eq. 3, for margalef species richness (d) see eq. 4 and for sørensen-dice similarity see eq. 5 and table 1. tested the proportions of species throughout the sequence according to their size (microfauna vs macrofauna) and their diet (herbivores vs carnivores). the results of the chi² test indicate no significant differences between microfauna and macrofauna between the fus. the same is true for the proportion of herbivores and carnivores (table 6-a to 6-d). one possible explanation for these results is that regardless of the different types of climate in a small sampling area (e.g. within habitat), there is no significant difference between the richness of small and large size species within animal communities (brown & nicoletto, 1991). at larger spatial scales, the pattern is quite different with small species generally far exceeding the number of large species (bakker & kelt, 2000). 4.3. cenograms the cenograms in figure 4 illustrate the difference in total species richness (s) between the fus as a function of their body mass (y-axis): the higher the rank, the lightest the species (x-axis). in all fus, a very clear break in slopes for species around 100 g can be observed, which has already started at about the limit of 500 g. medium-sized species (500 g to 250 kg without carnivores) are less represented in all faunal units except in fuiv+v. finally, the large-sized species (more than 250 kg) are scarce. according legendre’s method, there are two general trends in coudoulous i: either an open-arid landscape simultaneous with a decrease in small mammals as well as the total species richness (e.g. fuvii), or closed-arid landscapes with an increase in small mammals and highest species richness with possibly more humid climate trend (e.g. fuiv+v). these two opposing profiles should help inform our reading of the evolution of landscapes. for example, fuvii fits well with the results of gingerich (1989) for open-arid environments. in these typical landscapes, the slope of the cenograms is more pronounced with a larger gap around the limit of 500 g, a scarcity of medium-sized species (500 g to 250 kg) and finally the lowest total species richness. nevertheless, there are inconsistencies between the general shape of these two opposing cenograms and some paleoclimatic proxies such as map and ai (counterintuitively the higher the ai, the lower the aridity) (tab. 4). indeed, the latter show a more arid climatic trend in fuiv+v (ai=52.89 map = 972.20 mm) than in fuvii (ai=71.50 and map = 1236.79 mm). furthermore, the range of values provided by de martonne (1926) and reworked by pellicone et al. (2019) for ai < 50 indicates a humid climate. the results obtained with the paleoclimatic proxies and the cenograms do not invalidate each other. however, they seem to indicate a wetter climate trend than the theoretical pattern of the model suggests, with more pronounced humidity in fuvii than in fuiv+v. furthermore, we have to keep in mind that ai is a continuous complex gradient difficult to interpret, which spans several biomes (e.g. from tropical rainforest to tropical deciduous woodland, to savanna, to desert) (hernándezfernández et al., 2006). gómez cano et al. (2006) have shown that ceno 98 fernandez p. et al. tab. 6 a) species richness (s) for microfauna and macrofauna in faunal units of coudoulous i ; b) chi² test between species richness (microfauna vs macrofauna) in fus; c) species richness (s) for herbivores and carnivores in fus; d) chi² test between species richness (herbivores vs carnivores) in fus. fig. 4 cenograms according to the body mass (in g) for each faunal unit (fuii to fuvii) in coudoulous i. for predator prey ratio (ppr=n predator /n prey) see details in text. filled circles for bats, reptiles and amphibians. red filled circles for carnivores. paleoecologial first results from the middle pleistocene sequence of coudoulous i (quercy, lot, france). 99 gram analyses work well with a random species loss of up to 60-70% in a fossil assemblage. the unequal sizes of the samples and the possible biases in representation of the species led us to calculate a confidence interval for the body mass of predators (excluding mustelids, m. meles, v. vulpes and f. silvestris), their prey (ungulates) and small mammals in each fu (table 7-a). the bootstrap percentiles interval function in r (version 3.2.1) makes it possible to provide the mean and the 2.5% and 97.5% percentile of the bootstrap distribution as confidence intervals (see details in efron & tibshirani, 1993). the predators, their prey and the small mammals showed relatively similar body mass confidence intervals in the different fus (table 7-a). to investigate this further we undertook a kruskal-wallis analysis, using the multiple pairwise comparisons option (xlstat version 2017.1.1) to detect possible significant changes in their body mass (table 7-b). our results are mainly consistent with previous observations about a stable community over time. only the body mass values for small mammals from fuvii and fuvi are statistically different and should be explored to distinguish between evolutionary aspects (ecomorphology) or more likely sampling bias (s.l.) as discussed for fuvii. 4.4. predation in present-day ecosytems, terrestrial carnivores are much rarer than most of their prey due to the competition with predators of similar sizes to avoid the overconsumption of the resources on which they depend (peters & wassenberg, 1983; hatton et al., 2015). as expected, the ppr calculated in all of the fus are always lower than 1 (fig. 4). they are relatively stable in the sequence at around 0.6, with the exception of fuvii (ppr = 0.43) and fuii (ppr = 0.29). on a longer time scale, ppr ratio seems to be very dependent on the renewal of the plio-pleistocene fauna with the arrival or the extinction of certain predators (raia et al., 2007; croitor & brugal, 2010). for now, it is difficult to infer predators-prey interactions including man in coudoulous i except that the greater ppr, the more important the ci in each fu. 4.5. bioclimatic analysis in coudoulous i, the mean annual temperatures (mat) in the different faunal units are relatively similar to those established on the exclusive basis of the microfauna by jeannet (2021) (tab. 4). nevertheless, mat alone does not permit the distinction between bioclimatic components, except in the case of very different ecozones (rivas-martínez et al., 1999). this is not the case with the mean annual thermal amplitude (mata or ic in rivas-martinez et al., 1999) that constitutes an excellent indicator of continentality. the mata values recorded in fuvii, fuiv+v and fuiii correspond to a semi-continental climate (ic 18 to 21 in rivas-martínez et al., 1999, p. 8) and to a subcontinental climate in fuvi and fuii (ic 21 to 28 according to the same authors). in both cases the winters were harsh and the summers hot and rainy. the annual positive temperature index (apti) calculated at coudoulous i indicates that the apti values are all between around 900 and 1100 and correspond to the interval of the sub-mediterranean temperate bioclimatic variant (800 <apti> 1400, see rivas-martínez et al., 1999). likewise, the compensated thermal indices tab. 7 a) body mass (kg) bootstrap confidence interval distribution (95%) for prey (ungulates), predators (excluding all mustelids, meles meles, vulpes vulpes, felis silvestris) and small mammals in fus (calculation with the bootstrap percentiles interval function in r, version 3.2.1). b) kruskal-wallis test for comparing the body mass (kg) of prey (ungulates), predators (excluding all mustelids, meles meles, vulpes vulpes, felis silvestris) and small mammals in all fus (calculation from xlstat version 2017.1.1, using multiple pairwise comparisons option for the recalculation of the ranks for each two-by-two combination of the samples, < 0.0001 is highly significant). of coudoulous i all have values less than 180 which is consistent with this type of climate (see cti in rivasmartínez et al., 2004). finally, the most significant result concerns the faunal units, whose highest probabilities are all associated with the bioclimatic component vi, which corresponds to a typically temperate climate (tab. 4). the vegetation cover of bc vi consists of a nemoral zone dominated by deciduous forests with broadleaf trees (e.g. maple, oak, hickory, beech, chestnut) with several different kinds of plants like mountain laurel, azaleas and mosses. the bryophyte stratum and terrestrial lichens as well as various dwarf plants are very developed, while there are few herbaceous plants. nevertheless, a poorly diversified or even mono-specific cover cannot be excluded in this type of environment (hernández-fernández, 2001a). this kind of vegetation cover is potentially located between the boreal zone (coniferous forests) and the mediterranean zone (sclerophyllous forests). in table 4, fuii and fuvii, are both associated with bc viii as second probabilities, with cold boreal type climate elements. these results completely match the paleoenvironmental conclusions of jeannet (2021) which indicate much more severe climatic conditions in fuii and fuvii. fuii could be related to mis 6 with climatic degradation as mentioned previously, and fuvii to a cooler phase of mis 7 or older (mis 8?). the existence of large ice caps at the north pole during ice ages, in conjunction with the scandinavian anticyclone weather systems, likely generated continental surface winds coming from the east, and caused a decrease in precipitation in eurasia (cohmap, 1988). for example, in france during these colder periods, there is a decrease in precipitation (down to a minimum of 600 mm during the würm), unlike the hottest interglacial periods where precipitation can reach 1200 mm during the eemian (hernández-fernández, 2001a). while it is very likely (probability 1 and 2) that fuii, fuvii show climatic affinities with continental elements, the combination of aridity (ai) and rainfall pattern (map) related with thermal indices (mat, mtcm, apti) seems to exclude a typical boreal climate in these faunal units, even in its mildest variant (sensu rivas-martínez et al., 1999, 2004) (see tab. 4). however, in all of the fus of coudoulous i the association of some species present today but in environments with very different environmental characteristics raises the question of their ecological plasticity and their contemporaneity. as an example, in fuiv+v we note the presence of dicrostonyx torquatus and sorex minutissimus which live today in very severe climatic conditions, unlike oryctolagus cuniculus or to a lesser extent microtus arvalis, which are generally associated with a much warmer climate. during the late pleistocene, the association of d. torquatus and m. arvalis is not uncommon in southwestern france and reflects the ecological adaption of some taxa that evolved in very specific biomes (royer et al., 2016). this kind of association is part of the “disharmonious communities” of animals and plants adapted to a climate that has no modern counterpart (huggett, 2004). it could be explained by refuge areas forming a mosaic of settlements of small populations dispersed in several habitats, known as the “patch -corridor-matrix model”, allowing their survival and cohabitation (huggett & cheesman, 2002). regardless of the potential for climate adaptation of species and the plasticity of their ecological niche in the pleistocene, there is no doubt that the temporal resolution of the faunal units of coudoulous i corresponds to a grouping of different temporal phases. 5. conclusion in current ecological studies, species richness has been demonstrated to vary consistently with large-scale geographical factors such as latitude and altitude. the sequence of coudoulous i allows us to follow an entire animal community and its relationship to paleoenvironmental changes through time at a local scale. first of all, it appears that fuii and fuvii are different from the other faunal units, with their low-quality samples, unbalanced and low ppr and the lowest species richness values. fuii, which is the most recent faunal unit, may belong to the first part of mis 6, with new paleoenvironmental conditions. fuvii is the oldest faunal association and is very well individualized as it is composed of a single level (8d) that may correspond to a cooler phase of mis 7 or older (mis 8?). fuvii has the lowest species richness and above all an extremely disturbed assemblage as identified by the completeness index (ci). nevertheless, fuvii has a greater diversity than fuii which provides a much larger number of species. this shows that the shannon-wiener (h’) performs well and is very sensitive to the individual distribution frequency even if there is a great imbalance of the species richness between samples. in the rest of the sequence, the faunal associations fuiii to fuvi show both greater diversity and species richness, thus indicating a greater number of trophic levels and a more stable community. the concept of the “insurance hypothesis”, which states that the greater the species richness, the more important are the interactions between species, is supported by the rarefaction curves that are systematically in line with margalef (d). the number of species, according their body mass and their diet, displays no significant differences between all the fus, as is usual in a small sampling area (e.g. within habitat). in addition, the sørensen-dice index almost always indicates a greater similarity of common species between the closest fus throughout the sequence. this reveals a gradual turnover of species through time, probably due to paleoenvironmental changes. the predators, their prey and the small mammals showed no significant changes in their body mass through time, with the exception of the small mammals between fuvii and fuvi, which probably indicates the same pattern of evolution throughout the sequence. we showed clearly for fuii and fuvii that the lower the completeness index, the lower the ppr. this ratio is practically the same in the rest of the sequence but difficult to interpret from the small number of predators and their prey. theoretically, body mass distribution analysis in the cenograms should be efficient with a random spe 100 fernandez p. et al. paleoecologial first results from the middle pleistocene sequence of coudoulous i (quercy, lot, france). 101 cies loss of up to 60-70% in a fossil assemblage. we established the cenograms in the different fus and found them consistent with the pattern of a temperate climate corresponding to the bioclimatic component vi. according their theoretical slopes, breakpoints and species richness we identified two general trends corresponding to an open-arid and more closed-arid climate. nevertheless, a cross reading with paleoclimatic proxies revealed a wetter climate trend than the theoretical pattern arid-open landscape suggests. in addition to the cenograms, the bioclimatic model based on transfer functions from current mammalian associations clearly showed that the paleoecological requirements of coudoulous i species were very similar between the different faunal units. while there were significant climatic changes, they remained limited enough to prevent any complete turnover of species. one of the key outputs is the maximum probabilities calculated for each fu that are all systematically associated with the bioclimatic component vi. this component corresponds to a typical temperate climate with a predominance of deciduous forests that could potentially be located between the boreal zone (coniferous forests) and the mediterranean zone (sclerophyllous forests). at coudoulous i, submediterranean temperate elements dominate throughout the sequence but faunal units such as fuvii, fuiv+v and fuiii show affinities with semi-continental or subcontinental conditions (i.e. fuvi, fuii). finally, the paleoclimatic proxies from the bioclimatic model make it possible to exclude a boreal-type climate. acknowledgements several studies of interest to geology, dating, taxonomy and paleoenvironment have been carried out on this coudoulous i sequence in recent years which will be soon published as part of a monograph 2021 under the direction of j. jaubert. we want to warmly thank people of the team working on this site, especially faunal specialists a. argant (felids and ursids), m. boudadi-maligne (canids), f. lacombat (rhinocerotids), b. labe (proboscids), n. lateur (cervids), j.b. mallye (mustelids), and geostratigraphers b. kervazo and colleagues. we thank the editor of amq as well as the two anonymous reviewers for their unvaluable inputs and comments on previous draft. finally, we are extremely grateful to prof. lucy wilson (university of new brunswick, canada) for the corrected english version of the manuscript. references adrain j.m., westrop s.r., chatterton b.d.e., ramsköld l. (2000) silurian trilobite alpha diversity and the end-ordovician mass extinction, paleobiology, 26, 4, 625-646. andrews p. (1990) owls, caves and fossils: predation, preservation and accumulation of small mammal bones in caves, with an analysis of the pleistocene cave faunas from westbury-submendip, somerset, uk, university of chicago press (ed.). andrews p., o'brien e.m. (2000) climate, vegetation, and predictable gradients in mammal species richness in southern africa. journal of zoology, 251, 205-231. doi: 10.1111/j.1469-7998.2000.tb00605. argant a. (2021) les ursidés et les félidés de coudoulous 1 (tour-de-faure, lot). in: jaubert j., brugal j.p., jeannet m., kervazo b., mourre v., thiébaut c. (eds). coudoulous i: séquence du pléistocène moyen en quercy ou comment l’animal commande l’homme et vice-versa. musée national d'histoire et d'art, luxembourg, collection archéologiques, dir. f. le brun-ricalens. bakker v.j., kelt d.a. (2000) scale‐dependent patterns in body size distributions of neotropical mammals. ecology, 81(12), 3530-3547. baron j.p. (1997) démographie et dynamique d'une population française de vipera ursinii ursinii (bonaparte, 1835), thèse de doctorat, ecole pratique des hautes etudes, paris, 201. belmaker m. (2006) community structure through time: ubeidiya, a lower pleistocene site as a case study, phd thesis, hebrew university of jerusalem, israel, 284. belmaker m., hovers e. (2011) ecological change and the extinction of the levantine neanderthals: implications from a diachronic study of micromammals from amud cave, israel, quaternary science reviews, 30, 3196-3209. bernard a., daux v., lécuyer c., brugal j.p., genty d., wainer k., gardien v., fourel f., jaubert j. (2009) pleistocene seasonal temperature variations recorded in the δ 18o of bison priscus teeth. earth and planetary science letters, 283, 133143. doi: 10.1016/j.epsl.2009.04.005 bhatnagar y.v., lovari s. (2008) hemitragus jemlahicus. the iucn red list of threatened species 2008: e.t9919a13027389. doi: 10.2305iucn.uk.2008.rlts.t9919a13027389. bogaerts s. (2006) first data on the reproduction of lanza’s skink, chalcides lanzai pasteur, 1967. pod@rcis, 7 (1/2), 9-16. bonifay e., clottes j. (1981) le gisement de coudoulous à tour-de-faure (lot). xxie congr. préhist. de france, cahors-montauban-figeac, in "la préhistoire du quercy dans le contexte de midi-pyrénées, vol.1, 27-28. boudadi-maligne m. (2010) les canis pléistocènes du sud de la france: approche biosystématique, évolutive et biochronologique. université de bordeaux 1 (unpublished phd thesis). boudadi-maligne m. (2021) les grands canidés (genres canis et cuon) des niveaux inférieurs de coudoulous 1. in: jaubert j., brugal j.p., jeannet m., kervazo b., mourre v., thiébaut c. (eds). coudoulous i: séquence du pléistocène moyen en quercy ou comment l’animal commande l’homme et vice-versa. musée national d'histoire et d'art, luxembourg, collection archéologiques, dir. f. le brun-ricalens. briand f. (1983) environmental control of food web structure. ecology, 64, 253-263. brugal j.p. (2006) les gisements paléontologiques et archéologiques de coudoulous (tour-de-faure, coudoulous). annales des rencontres archéologiques de saint-céré, 13, 3-17. brugal j.p. (1999a) etude des populations de grands bovidés européens: intérêt pour la connaissance des comportements humains au paléolithique. in le bison, gibier et moyen de subsistance des hommes du paléolithique aux paléoindiens des grandes plaines, j.p. brugal, f. david, j. enloe, j. jaubert (dir.), le bison, gibier et moyen de subsistance, du paléolithique au paléoindien des grandes plaines, actes du colloque de toulouse 1995, adpca, antibes, 85-103. brugal j.p. (1999b) middle palaeolithic subsistence on large bovids: la borde and coudoulous i (lot, france). in the role of early humans in the accumulation of european lower and middle palaeolithic bone assemblages, s. gaudzinski, e. turner (dir.), monographien des römisch-germanischen zentralmuseums mainz, 42, 263-266. brugal j.p. (2021) le matériel faunique non déterminable: apports taphonomique et géostratigraphique. exercice sur la séquence de coudoulous i. in: jaubert j., brugal j.p., jeannet m., kervazo b., mourre v., thiébaut c. (eds). coudoulous i: séquence du pléistocène moyen en quercy ou comment l’animal commande l’homme et viceversa. musée national d'histoire et d'art, luxembourg, collection archéologiques, dir. f. le brunricalens. brugal j.p., argant a., boudadi-maligne m., crégutbonnoure e., croitor r., fernandez p., fourvel j.b., fosse p., guadelli j.l., labe b., magniez p., uzunidis a. (2020) pleistocene herbivores and carnivores from france: an updated overview of the literature, sites and taxonomy. annales de paléontologie, 106(2). doi: 10.1016/j.annpal.2019.102384 brugal j.p., beauval c. castel j.c., costamagno s., coumont m.p., fournier j., gerbe m., griggo c., juillard f., kuntz d. (2013) les peuplements mammaliens au pléistocène moyen et supérieur en quercy. in modalité d’occupation et exploitation des milieux au paléolithique dans le sud-ouest de la france: l’exemple du quercy. jarry m., brugal j.p., ferrier c. (dir), paléo, suppl. 4, 145-158. brugal j.p., costamagno s., jaubert j., mourre v. (1998) les gisements paléolithiques de coudoulous (tour-de-faure, lot, france). proceedings of the xiii congress uispp, forli (italia), 1996, sect. 5 ‘paléolithique inférieur et moyen’, vol. 2, 141145. brugal j.p., jaubert j. (1991) les gisements paléontologiques pléistocènes à indices de fréquentation humaine: un nouveau type de comportement de prédation ? paléo, 3, 15-41. brugal j.p., jaubert j. (2006) a long palaeolithic sequence in southwest france: the karstic sites of coudoulous (lot, quercy, france). paper presented at paleoanthropology society, april 24 -26th, 2006, san juan, puerto rico. brugal j.p., croitor r. (2010) evolution, ecology and biochronology of herbivores associations in europe during the last 3 million years. quaternaire, 18 (2), 129-152. brugal j.p., jaubert j. (2021) neanderthal subsistence strategies at the karstic sites of coudoulous in the quercy (sw france) from marginal scavenging to a kill-butchery site, and back. in: gaudzinski-windheuser s. & jöris o. (eds). the beef behind all possible pasts. the tandem festschrift in honour of elaine turner and martin street. monographien des rgzm 157 (mainz 2021). doi: 10.11588/propylaeum.868.c11308 brown j.h., nicoletto p.f. (1991) spatial scaling of species composition: body masses of north american land mammals. american naturalist, 138(6): 1478-1512. carbone c., mace g.m., roberts s.c., macdonald d.w. (1999) energetic constraints on the diet of terrestrial carnivores. nature, 402, 286-288. castellano s., giacoma c. (1998) morphological variation of the green toad, bufo viridis, in italy: a test of causation. journal of herpetology, 32(4), 540-550. doi: 10.2307/1565208 cohmap members (1988) climatic changes of the last 18,000 years: observations and model simulations, science, 241, 4869, 1043-1052. costamagno s. (1999) coudoulous ii: taphonomie d’un aven-piège. contribution des accumulations d’origine naturelle à l’interprétation des archéofaunes du paléolithique moyen. anthropozoologica, 29, 13-32. couchoud i. (2006) etude pétrographique et isotopique de spéléothèmes du sudouest de la france en contexte archéologique. phd thesis. university of bordeaux i. croft d.a. (2001) cenozoic environmental change in south america as indicated by mammalian body size distributions (cenograms). diversity and distributions, 7(6), 271-287. croitor r., brugal j.p. (2010) ecological and evolutionary dynamics of the carnivore community in europe during the last 3 million years. quaternary international, 212, 98-108. damuth j., macfadden b.j. (1990) body size in mammalian paleobiology: estimation and biological implications. cambridge university press. davis e.b., pyenson n.d. (2007) diversity biases in terrestrial mammalian assemblages and quantifying the differences between museum collections and published accounts: a case study from the miocene of nevada, palaeogeography, palaeoclimatology, palaeoecology, 250, 139-149. de martonne e. (1926) aréisme, et indices d’aridité. comptes rendus de l’academie des sciences, 182, 1395-1398. dice l.r. (1945) measures of the amount of ecologic association between species. ecology, 26, 297302. 102 fernandez p. et al. paleoecologial first results from the middle pleistocene sequence of coudoulous i (quercy, lot, france). 103 edgar p., bird d.r. (2006) action plan for the conservation of the aesculapian snake (zamenis longissimus) in europe. convention on the conservation of european wildlife and natural habitats, t-pvs/inf 2006-19, 1-23. efron b., tibshirani r.j. (1993) an introduction to bootstrap. monographs on statistics and applied probability, 57, chapman & hall/crc. fenchel t. (1993) there are more small than large species? oikos, 68(2), 375-378. fernandez p. (2009) mammalian dynamics and palaeoecological analysis during the pleistocene in kozarnika cave (bulgaria). in: gatsov i. & guadelli j.l. (eds). mélanges en l'honneur de nikolay sirakov, saxa loquuntur, sofia, 59-73. fernández-jalvo y., denys c., andrews p., williams t., dauphin y., humphrey l. (1998) taphonomy and palaeoecology of olduvai bed-i (pleistocene, tanzania). journal of human evolution, 34, 137-172. fortelius m., made j.v.d., bernor r.l. (1996) middle and late miocene suoidea of central europe and the eastern mediterranean: evolution, biogeography, and paleoecology. in: bernor, r.l., fahlbusch, v., mittmann, h.w. (eds). the evolution of western eurasian neogene mammal faunas, columbia university press, new york, 348-377. freudenthal m., martín-suárez e. (2013) estimating body mass of fossil rodents. scripta geologica, 145, 1-513. gaines w.l., harrod j.r., lehmkuhl j.f. (1999) monitoring biodiversity: quantification and interpretation. general technical report pnw-gtr-443, usda forest service, pacific north-west research station. giannoni s.m., márquez r., borghi c.e. (1997) airborne and substrate-borne communications of microtus (terrícola) gerbei and m. (t.) duodecimcostatus. acta theriologica, 42, 123-141. gingerich p.d., smith b.h., rosenberg k. (1982) allometric scaling on the dentition of primates and prediction of body size in fossils. american journal of physical anthropology, 58, 81-100. gingerich p.d. (1989) new earliest wasatchian mammalian fauna from the eocene of northwestern wyoming: composition and diversity in a rarely sampled highfloodplain assemblage. papers in palaeontology. university of michigan, 28, 1-97. gómez cano a.r., garcía yelo b.a., hernández fernández m. (2006) cenogramas, análisis bioclimático y muestreo en faunas de mamíferos: implicaciones para la aplicación de métodos de análisis paleoecológico. estudios geológicos, 62, 135-144. gotelli n.j., colwell r.k. (2001) quantifying biodiversity: procedures and pitfalls in the measurement and comparison of species richness. ecology letters, 4, 379-391. graitson e., jacob j.p. (2007) la coronelle lisse coronella austriaca (laurenti, 1768). in: jacob j.p., percsy c., de wavrin h., graitson e., kinet t. denoël m., paquay m., percsy n., remacle a. (eds). amphibiens et reptiles de wallonie. avesraînne et centre de recherche de la nature, des forêts et du bois (mrw dgrne), fauneflore-habitats n° 2, namur, belgium, 244-245. grayson d.k. (1984) quantitative zooarchaeology, academic press, orlando. haerty w., gentilhomme e., secondi j. (2007) female preference for a male sexual trait uncorrelated with male body size in the palmate newt (triturus helveticus). behaviour, 144(7), 797-814. hammer ø., harper d.a.t., ryan p.d. (2001) past: paleontological statistics software package for education and data analysis. palaeontologia electronica, 4(1), p. 9. hammer ø., harper d.a.t. (2006) paleontological data analysis, editorial blackwell publishing ltd, oxford. hatton i.a., mccann k.s., fryxell j.m., davies t.j., smerlak m., sinclair a.r.e., loreau m. (2015) the predator-prey power law: biomass scaling across terrestrial and aquatic biomes. science, 349(6252), aac6284–aac6284. doi: 10.1126/science.aac6284 hernández-fernández m. (2001a) análisis paleoecológico y paleoclimático de las sucesiones de mamíferos del plio-pleistoceno ibérico. phd thesis. universidad complutense de madrid. hernández-fernández m. (2001b) bioclimatic discriminant capacity of terrestrial mammal faunas. global ecology biogeography, 10, 189-204. hernández-fernández m., peláez-campomanes p. (2003) the bioclimatic model: a method of palaeoclimatic qualitative inference based on mammal associations. global ecology and biogeography, 12, 507-517. hernández-fernández m., peláez‐campomanes p. (2005) quantitative palaeoclimatic inference based on terrestrial mammal faunas. global ecology and biogeography, 14, 39-56. doi: 10.1111/j.1466-822x.2004.00125.x hernández-fernández m., alberdi m.t., azanza b., montoya p., morales j., nieto m., peláezcampomanes p. (2006) identification problems of arid environments in the neogene-quaternary mammal record of spain. journal of arid environments, 66, 585-608. hernández-fernández m., álvarez-sierra m.a., peláez -campomanes p. (2007) bioclimatic analysis of rodent palaeofaunas reveals severe climatic changes in southwestern europe during the pliopleistocene. palaeogeography, palaeoclimatology, palaeoecology, 251, 500-526. hernandez m., bahain j.j., mercier n., tombret o., falguéres c., jaubert j. (2015) dating results on sedimentary quartz, bones and teeth from the middle pleistocene archaeological site of coudoulous i (lot, sw france): a comparative study between tt-osl and esr/u-series methods. quaternary geochronology, 30, 493-497. hill j.e., smith j.d. (1984) bats: a natural history, british museum (natural history), londres. huggett r.j., cheesman j.e. (2002) topography and the environment. harlow, essex: prentice hall. huggett r.j. (2004) fundamentals of biogeography, routledge, new york. ives a.r., klug j.l., gross k. (2000) stability and species richness in complex communities. ecology letters, 3(5), 399-411. doi: 10.1046/j.1461-0248.2000.00144.x jaccard p. (1912) the distribution of the flora in the alpine zone.1. new phytologist, 11, 37-50. doi: 10.1111/j.1469-8137.1912.tb05611.x jacob j.p. (2007) la rainette verte hyla arborea (linnaeus, 1758). in: jacob j.p., percsy c., de wavrin h., graitson e., kinet t., denoël m., paquay m., percsy n., remacle a. (eds). amphibiens et reptiles de wallonie. aves-raînne et centre de recherche de la nature, des forêts et du bois (mrw dgrne), faune-flore-habitats n° 2, namur, belgium, 153-163. jaubert j. (1984) contribution à l'étude du paléolithique ancien et moyen des causses. thèse 3e cycle, université de paris i panthéon-sorbonne, 2 vol., 615. jaubert j. (1995) schémas opératoires et outillages peu élaborés: le cas du paléolithique inférieur et moyen de coudoulous i (lot). in: carbonell e. (ed), cahier noir, 7, universitat rovira i virgili, tarragona, 85-100. jaubert j., kervazo b., brugal j.p., falgueres c., jeannet m., louchard a., martin h., maksud f., mourre v., quinif y. (2005) la séquence pléistocène moyen de coudoulous i (lot). bilan pluridisciplinaire. in: les premiers peuplements en europe: données récentes sur les modalités de peuplement et sur le cadre chronostratigraphique, géologique et paléogéographique des industries du paléolithique ancien et moyen en europe, molines n., moncel m.h., monnier j.l. (éds), (actes du coll. intern. rennes, 22-25 septembre 2003), oxford, british archaeological reports, international series, 1364, 237-251. jaubert j., allard m., bahain j.j., bordes j.g., bourguignon l., brugal j.p., castel j.c., chalard p., clottes j., couchoud i., ducasse s., faivre j.p., falguères c., fontugne m., guillermin p., jarry m., ladier e., langlais m., mourre v., oberlin c., quinif y., renard c., turq a., valladas h. (2013) le quercy pléistocène: région à peuplement continu depuis 0,3 ma ? archéostratigraphie et datations radiométriques. in modalité d’occupation et exploitation des milieux au paléolithique dans le sud-ouest de la france: l’exemple du quercy. jarry m., brugal j.p., ferrier c. (dir), paléo, suppl. 4, 67-105. jaubert j., servelle c. (1996) l'acheuléen du bassin de la garonne. etat de la question et implications. in tuffreau, a. (ed.), l'acheuléen dans l'ouest de l'europe, publ. du centre d'etudes et de recherches préhistoriques (cerp), univ. des sciences et technologies de lille, (actes du colloque internat. de saint-riquier, 6-10 juin 1989), n°4, 77-108. jeannet m. (2010) l’écologie quantifiée. essai de description de l’environnement continental à l’aide des microvertébrés (quantified ecology. draft description of the continental environment using microvertebrates), préhistoires méditerranéennes, 1, 11-34. jeannet m., brugal j.p., jarry m. (2013) microfaune et paléoclimatologie dans le pléistocène moyen et supérieur du quercy. essai d‘écologie quantifiée. in modalité d’occupation et exploitation des milieux au paléolithique dans le sud-ouest de la france: l’exemple du quercy. jarry m., brugal j.p., ferrier c. (dir), paléo, suppl. 4, 107-143. jeannet m. (2021) la microfaune de coudoulous i: paléoenvironnement et biostratigraphie selon les microvertebrés. in: jaubert j., brugal j.p., jeannet m., kervazo b., mourre v., thiébaut c. (eds). coudoulous i: séquence du pléistocène moyen en quercy ou comment l’animal commande l’homme et vice-versa. musée national d'histoire et d'art, luxembourg, collection archéologiques, dir. f. le brun-ricalens. kervazo b., jaubert j., bruxelles l., ferrier c., konik s., brugal j.p., o’yl w., queffelec a. (2021) etude géologique de coudoulous i. in: jaubert j., brugal j.p., jeannet m., kervazo b., mourre v., thiébaut c. (eds). coudoulous i: séquence du pléistocène moyen en quercy ou comment l’animal commande l’homme et vice-versa. musée national d'histoire et d'art, luxembourg, collection archéologiques, dir. f. le brun-ricalens. legendre s. (1986) analysis of mammalian communities from the late eocene and oligocene of southern france. palaeovertebrata, 16, 191-212. legendre s., roth c. (1988) correlation of carnassial tooth size and body weight in recent carnivores (mammalia), historical biology, 1, 85-98. legendre s. (1989) les communautés de mammifères du paléogène (eocène supérieur et oligocène) d’europe occidentale: structures, milieux et évolution. münchner geowissenschaftliche abhandlungen, munich, (a), 16, 1-110. lelièvre h. (2010) stratégies de thermorégulation chez deux colubridés sympatriques: la couleuvre verte et jaune hierophis viridiflavus et la couleuvre d’esculape zamenis longissimus. une approche intégrée de la physiologie à la démographie. planète et univers [physics]. thèse de doctorat, université de poitiers, 1-227. leonard r.d., jones g.t. (1988) quantifying diversity in archaeology, cambridge university press, new york. lodé t. (1993) rythme d'activité et déplacements chez la grenouille agile rana dalmatina bonaparte 1840. bulletin société herpétologique de france, 67-68, 13-22. lópez-garcía j.m., cuenca-bescós g., galindopellicena m.á., luzi e., berto c., lebreton l., desclaux e. (2021) rodents as indicators of the climatic conditions during the middle pleistocene in the southwestern mediterranean region: implications for the environment in which hominins lived, journal of human evolution, 150. 104 fernandez p. et al. paleoecologial first results from the middle pleistocene sequence of coudoulous i (quercy, lot, france). 105 doi: org/10.1016/j.jhevol.2020.102911 lovari s., lorenzini r., masseti m., pereladova o., carden r.f., brook s.m. (2016a) cervus elaphus. the iucn red list of threatened species 2016: e.t55997072a22155320. lovari s., herrero j., masseti m., ambarli h., lorenzini r., giannatos g. (2016b) capreolus capreolus. the iucn red list of threatened species 2016: e.t42395a22161386 lyman r.l. (2008) quantitative paleozoology, cambridge manuals in archaeology series. new york: cambridge university press. maas m.c., krause d.w. (1994) mammalian turnover and community structure in the paleocene of north america. historical biology, 8, 91-128. maas m.c., anthony m.r.l., gingerich p.d., gunnell g.f., krause d.w. (1995) mammalian generic diversity and turnover in the late paleocene and early eocene of the bighorn and crazy mountains basins, wyoming and montana (usa), palaeogeography, palaeoclimatology, palaeoecology, 115, 181-207. mallye j.b. (2021) les mustélidés du gisement pléistocène moyen de coudoulous locus 1. in: jaubert j., brugal j.p., jeannet m., kervazo b., mourre v., thiébaut c. (eds). coudoulous i: séquence du pléistocène moyen en quercy ou comment l’animal commande l’homme et viceversa. musée national d'histoire et d'art, luxembourg, collection archéologiques, dir. f. le brunricalens. margalef r. (1958) information theory in ecology. general systems, 3, 36-71. matz g., weber d. (1999) guide des amphibiens et reptiles d'europe. les 173 espèces européennes. ed: delachaux et niestlé, lausanne, paris, p. 292. isbn 2-603-01118-9 mokeddem z., mcmanus j.f. (2016) persistent climatic and oceanographic oscillations in the subpolar north atlantic during the mis 6 glaciation and mis 5 interglacial, paleoceanography, 31, 758-778. doi: 10.1002/2015pa002813 montuire s. (1994) communautés de mammifères et environnements, l’apport des faunes aux reconstitutions des milieux en europe depuis le pliocène et l’impact des changements climatiques. thèse de doctorat, université montpellier ii, 1128. montuire s. (1999) mammalian faunas as indicators of environmental and climatic changes in spain during the pliocene-quaternary transition. quaternary research, 52, 129-137. montuire s., desclaux e. (1997) palaeoecological analysis of mammalian faunas and environmental evolution in the south of france during the pleistocene. boreas, 26, 355-365. montuire s., marcolini f. (2001) palaeoenvironmental significance of the mammalian faunas from italy since the pliocene. journal of quaternary science, 17(1), 87-96. mourgues m. (1908) catalogue raisonné de la faune herpétologique des environs de sainte-cécile sérignan, orange (vaucluse). la feuille des jeunes naturalistes, 38(4), 178-182. mourre v. (1996) les industries en quartz au paléolithique. terminologie, méthodologie et technique. paléo, 8, 205-223. naulleau g. (1983) the effects of temperature on digestion in vipera aspis. journal of herpetology, 17(2), 166-170. olsson m. (1993) male preference for large females and assortative mating for body size in the sand lizard (lacerta agiiis). behavioral ecology and sociobiology, 32, 337-341. olsson m., madsen t., shine r. (1997) is sperm really so cheap? costs of reproduction in male adders, vipera berus. proceedings: biological sciences, 264(1380), 455-459. palmqvist p., mendoza m., arribas a., gröcke d.r. (2002) estimating the body mass of pleistocene canids: discussion of some methodological problems and a new ‘taxon free’ approach. lethaia, 35, 358-360. palombo m.r., giovinazzo c. (2006) what do cenograms tell us about mammalian palaeoecology? the example of plio-pleistocene italian faunas. courierforschungsinstitut senckenberg, 256, 215-235. palombo m.r., sardella m., novelli m. (2008) carnivora dispersal in western mediterranean during the last 2.6 ma. quaternary international, 179, 176-189. palombo m.r. (2015) to what extent could functional diversity be a useful tool in inferring ecosystem responses to past climate changes? quaternary international. doi: org/10.1016/j.quaint.2015.07.069 pellicone g., caloiero t., guagliardi i. (2019) the de martonne aridity index in calabria (southern italy). journal of maps, 15(2), 788-796. doi: 10.1080/17445647.2019.1673840 popov v., marinska m. (2007) an almost one million year long (early to late pleistocene) small mammal succession from the archaeological layers of kozarnika cave in northern bulgaria. in: kahlke r.d., maul l.c., mazza p.p.a. (eds). late neogene and quaternary biodiversity and evolution: regional developments and interregional correlations. proceedings of the 18th international senckenberg conference (vi international palaeontological colloquium in weimar), courier forschungsinstitut senckenberg, frankfurt, 259, 7992. prado j.l., alberdi m.t., azanza b., rodríguez j. (2004) patterns of body-size change in large mammals during the late cenozoic in the northwestern mediterranean, miscelánea en homenaje a emiliano aguirre, museo arqueológico regional, madrid, 465-479. raia p., meloro c., barbera c. (2007) inconstancy in predator/prey ratios in quaternary large mammal communities of italy, with an appraisal of mechanisms, quaternary research, 67, 255-263. rapoport e.h. (1975) areografía: estrategias geograficas de las especies, fondo de cultura económica, méxico, d.f. raup d. (1975) taxonomic diversity estimation using rarefaction, paleobiology, 1(4), 333-342. reading c.j., davies j.l. (1996) predation by grass snakes (natrix natrix) at a site in southern england. journal of zoology, 239(1), 73-82. ricklefs r.e., miller g.l. (1999) ecology, freeman and company, new york. rivas-martínez s. (1994) clasificación bioclimática de la tierra, folia botanica matritensis, 13, 1-27. rivas-martínez s., sánchez-mata d., costa m. (1999) north american boreal and western temperate forest vegetation, itinera geobotanica, 12, 5-316. rivas-martínez s., penas a., díaz t.e. (2004) bioclimatic & biogeographic maps of europe, university of león, e-24071, spain. isbn 84-9773-276-6. rivas-martínez s., rivas-saenz s., penas a. (2011) worldwide bioclimatic classification system. global geobotany, 1, 1-634. rodríguez j., díez j.c., laplana c., nicolás m.e. (1996) estudio paleoecológico de la asociación de mamíferos del nivel td6 (pleistoceno inferior, sierra de atapuerca, burgos, espana). [palaeoecological study of the mammal assemblage from level td6 (lower pleistocene, sierra de atapuerca, burgos, spain)]. revísta española de paleontología, 11 (2), 199-206. rodríguez j. (1999) use of cenograms in mammalian palaeoecology. a critical review. lethaia, 32, 331347. doi: 10.1111/j.1502-3931.1999.tb00551.x rohde k. (1992) latitudinal gradients in species diversity: the search for the primary cause, oikos, 65(3), 514-527. royer a., montuire s., legendre s., discamps e., jeannet m., lécuyer c. (2016) investigating the influence of climate changes on rodent communities at a regional-scale (mis 1-3, southwestern france). plos one 11(1): e0145600. doi: 10.1371/journal.pone.0145600 royer a., garcía yelo b.a., laffont r., hernándezfernández m. (2020) new bioclimatic models for the quaternary palaearctic based on insectivore and rodent communities, palaeogeography, palaeoclimatology, palaeoecology, 560. doi: org/10.1016/j.palaeo.2020.110040 sanders h.l. (1968) marine benthic diversity: a comparative study. american naturalist, 102, 243-282. shannon c., weaver w. (1964) the mathematical theory of communication, the university of illinois press, urbana, 1-125. shi g.r. (1993) multivariate data analysis in palaeoecology and palaeobiogeography: a review. palaeogeography, palaeoclimatology, palaeoecology , 105, 199-234. simpson g.g. (1943) mammals and the nature of continents. american journal of science, 241(1), 1 -31. smith r.j. (2002) estimation of body mass in paleontology. journal of human evolution, 43, 271-287. doi: 10.1006/jhev.2002.0573 smith f.a., lyons s.k., ernest s.k.m., jones k.e., kaufman d.m., dayan t., marquet p.a., brown j.h., haskell j.p. (2003) body mass of late quaternary mammals. ecology 84: 3402 (mom-mammals version 4.1). sørensen t. (1948) a method of establishing groups of equal amplitude in plant society based on similarity of species content and its application to analyses of the vegetation on danish commons. kongelige danske videnskabernes selskab, biologiske skrifter, 5, 1-34. spellerberg i.f., fedor p.j. (2003) a tribute to claude shannon (1916-2001) and a plea for more rigorous use of species richness, species diversity and the «shannon-wiener» index. global ecology and biogeography, 12(3), 177-179. stoetzel e., el agbani m.a., qninba a., mouna m., mataame a., el brini h., denys d. (2010) inventaire taxonomique préliminaire des petits vertébrés terrestres du nord du maroc. bulletin de l’institut scientifique, section sciences de la vie, 2010, 32 (1), 17-24. šukalo g., dekić m., dikić d., dordević s., tomović l. (2014) new records of the common spadefoot toad, pelobates fuscus (anura: pelobatidae), in bosnia and herzegovina. ecologica montenegrina, 1(2), 92-95. sydlowski r. (2000) "salamandra salamandra", animal diversity web. accessed april 09, 2021 at animaldiversity.org/accounts/salamandra_salamandra. tipper j.c. (1979) rarefaction and rarefiction the use and abuse of a method in paleoecology. paleobiology, 5(4), 423-434. tougard c., renvoisé e., petitjean a., quéré j.p. (2008) new insight into the colonization processes of common voles: inferences from molecular and fossil evidence. plos one, 3, e3532. doi: 10.1371/journal.pone.0003532 tur-torres j. (2017-2018) ecología de la serpiente blanca, zamenis scalaris, en la isla de formentera. memòria del treball de fi de grau de biologia, universitat de les illes balears, facultat de ciències, 1-25. valensi p., psathi e. (2004) faunal exploitation during the middle palaeolithic in southeastern france and north-western italy. international journal of osteoarchaeology, 14, 256-272. valverde j.a. (1964) remarques sur la structure de l’évolution des communautés de vertébrés terrestres. i. structure d’une communauté. ii. rapport entre prédateurs et proies. terre et vie, 111, 121154. valverde j.a. (1967) estructura de una communidad de vertebrados terrestres. monografias de la estacion de doñana, 1, 1-129. van valkenburgh b., janis c.m. (1993) historical diversity patterns in north american large herbivores and carnivores. in: ricklefs r.e. & schluter d. (eds.). species diversity in ecological communities. the university of chicago press, chicago, 330-340. 106 fernandez p. et al. paleoecologial first results from the middle pleistocene sequence of coudoulous i (quercy, lot, france). 107 whittaker r.h. (1972) evolution and measurement of species diversity. taxon, 21(2/3), 213-251. yachi s., loreau m. (1999) biodiversity and ecosystem productivity in a fluctuating environment: the insurance hypothesis. proceedings of the national academy of sciences, 96(4), 14631468. doi: 10.1073/pnas.96.4.1463 zucchi c. (2021) lacerta bilineata. monaco nature encyclopedia.monaconatureencyclopedia.com/ lacerta-bilineata/. electronic references (1) museum national d'histoire naturelle (ed.) (2003-2021). myotis capaccinii (bonaparte, 1837) murin de capaccini, vespertilion de capaccini. inventaire national du patrimoine naturel. inpn.mnhn.fr/espece/cd_nom/60439/tab/fiche. (2) museum national d'histoire naturelle (ed.) (2003-2021). myotis mystacinus (kuhl, 1817) murin à moustaches, vespertilion à moustaches. inventaire national du patrimoine naturel. inpn.mnhn.fr/espece/cd_nom/60383/tab/fiche. (3) museum national d'histoire naturelle (ed.) (2003-2021). myotis bechsteinii (kuhl, 1817) murin de bechstein. inventaire national du patrimoine naturel. inpn.mnhn.fr/espece/cd_nom/79301/tab/fiche. (4) museum national d'histoire naturelle (ed.) (2003-2021). vespertilio murinus linnaeus, 1758 vespertilion bicolore, sérotine bicolore. inventaire national du patrimoine naturel. inpn.mnhn.fr/espece/cd_nom/60537/tab/fiche. (5) museum national d'histoire naturelle (ed.) (2003-2021). eptesicus serotinus (schreber, 1774) sérotine commune. inventaire national du patrimoine naturel. inpn.mnhn.fr/espece/cd_nom/60360/tab/fiche. (6) museum national d'histoire naturelle (ed.) (2003-2021). nyctalus noctula (schreber, 1774) noctule commune. inventaire national du patrimoine naturel. inpn.mnhn.fr/espece/cd_nom/60468/tab/fiche. (7) museum national d'histoire naturelle (ed.) (2003-2021). pipistrellus pipistrellus (schreber, 1774) pipistrelle commune. inventaire national du patrimoine naturel. inpn.mnhn.fr/espece/cd_nom/60479/tab/fiche. (8) museum national d'histoire naturelle (ed.) (2003-2021). barbastella barbastellus (schreber, 1774) barbastelle d'europe, barbastelle. inventaire national du patrimoine naturel. inpn.mnhn.fr/espece/cd_nom/60345/tab/fiche. (9) museum national d'histoire naturelle (ed.) (2003-2021). plecotus auritus (linnaeus, 1758) oreillard roux, oreillard septentrional. inventaire national du patrimoine naturel. inpn.mnhn.fr/espece/cd_nom/60518/tab/fiche. (10) museum national d'histoire naturelle (ed.) (2003-2021). plecotus austriacus (fischer, 1829) oreillard gris, oreillard méridional. inventaire national du patrimoine naturel. inpn.mnhn.fr/espece/cd_nom/60527/tab/fiche. (11) sologne nature environnement (2021, june 03) crapaud commun, bufo bufo. a la découverte de la sologne. decouvertesologne.fr/amphibiens-crustacees/le-crapaud-commun. (12) info fauna centre suisse de coordination pour la protection des amphibiens et reptiles de suisse (karch) (2021, june 03). crapaud calamite. karch.ch/karch/home/amphibien/amphibienarten-der-schweiz/ kreuzkrote.html. (13) marsh frog: pelophylax ridibundus (2021, march 5) az animals. a-z-animals.com/animals/marsh-frog/. (14) museum national d'histoire naturelle (ed.) (2003-2021). rana temporaria linnaeus, 1758 grenouille rousse. inventaire national du patrimoine naturel. inpn.mnhn.fr/espece/cd_nom/351/tab/fiche. (15) museum national d'histoire naturelle (ed.) (2003-2021). podarcis muralis (laurenti, 1768) lézard des murailles. inventaire national du patrimoine naturel. inpn.mnhn.fr/espece/cd_nom/77756/tab/fiche. (16) centre permanent d'initiatives pour l'environnement flandre maritime (2016, march 09). orvet fragile. cpieflandremaritime.fr/agir/un-dragon-dans-mon-jardin/fiches-reptiles/ article/orvet-fragile. (17) centre suisse de coordination pour la protection des amphibiens et reptiles de suisse (karch) (2021). couleuvre vipérine. karch.ch/karch/home/reptilien/reptilienarten-der-schweiz/ vipernatter.html. (18) google (n.d.). carte physique de la france, avec régions et départements. fr.wikipedia.org/wiki/ficher. ms. received: 14 january, 2021 revised: 29 january, 2021 accepted: 20 june, 2021 avaiable online: 14 july, 2021 108 amq29(2) 6 forno 181-191nag.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 29 (2), 2016, 181 191 preservation of quaternary sediments in dsgsd environments: the mont fallère case study (aosta valley, nw italy) m. gabriella forno1-2, cesare comina1, marco gattiglio1, franco gianotti1, stefano lo russo3, luca raiteri4, luigi sambuelli3, glenda taddia3   1 dipartimento di scienze della terra, università di torino, torino, italy 2 natrisk interdipartimental centre, università di torino, grugliasco, italy 3 dipartimento di ingegneria dell'ambiente, del territorio e delle infrastrutture, politecnico di torino, torino, italy 4 regione autonoma valle d'aosta, soprintendenza per i beni e le attività culturali, aosta, italy corresponding author: m. g. forno <gabriella.forno@unito.it> abstract: deep seated gravitational slope deformations (dsgsd) in the western alps, which usually affect glacial valleys, produce strong deformation in both bedrock and quaternary cover, generally favouring erosion. this research, which examines a dsgsd along the mont fallère southern slope in the aosta valley, suggests that dsgsd can also locally favour the formation and preservation of the quaternary stratigraphic successions for the following reasons: the development of transversal elongated depressions, which are essentially connected with the onset of gravitational structures (trenches, minor scarps, and counterscarps) and filled by differentiated quaternary successions; the occurrence of closed depressions along the slope, which originate from the gradual evolution of gravitational structures (trenches or minor scarps and associated counterscarps) and are occupied by lakes that are progressively filled by lacustrine and palustrine sequences; the occurrence of wide, flat, irregular surfaces that are characterized by lower erosional phenomena with respect to the surrounding steep slopes and preserve various quaternary stratigraphic successions; the development of rounded reliefs and associated wide depressions, both of which exhibit topographic surfaces that hang over torrential incisions that are located along the main fractures; this morphology favours the preservation of glacial, outwash, lacustrine and palustrine sediments; wide colluvial and debris cover that buries and partially preserves older quaternary sediments; the local occurrence of a travertine cover and cemented sediments, which preserve the older quaternary sediments. these morphological conditions are favourable to prehistoric human settlements, resulting in archaeological mountain sites that also provide a chronological reference for the evolution of dsgsd. keywords: aosta valley, dsgsd, quaternary sediments, prehistoric human settlement 1. introduction deep-seated gravitational slope deformations (dsgsd) are large mass movements on high-relief slopes that extend from the valley floor up to or beyond the ridge crest. these features have been found in most rock types and are generally characterized by discontinuous or poorly defined boundaries, large volumes (commonly >0.5 km3) and thicknesses, conspicuous surface gravitational features and relatively low rates of movement over long periods (mm/y, in alpine areas) (varnes et al., 1990; ambrosi & crosta, 2006; agliardi et al., 2012). the absence of a clear sliding surface could not be assumed as a dsgsd diagnostic feature compared to a landslide (sorriso-valvo, 1995). in detail, many "confined" landslides that have been described in the literature do not show a well-defined or complete sliding surface until their final collapse (hutchinson, 1988; cruden & varnes, 1993) and many dsgsd that have been observed in the central alps display, instead, a basal sliding surface (agliardi et al., 2001). this surface is sometimes partially coincident to a pre-existing tectonic discontinuity and is sometimes justified by the dsgsd’s kinematics. these phenomena cause the deformation and dislocation of the bedrock and the quaternary cover, creating many similar surface gravitational structures to those that are observable at a smaller scale in cohesive soil landslides (sorriso-valvo, 1995). the most common indicators of dsgsd are gravitational tensional structures at different scales, sometimes reported as morpho-structures including minor scarps, trenches and counterscarps along the deforming slopes and double or multiple ridges on the upper parts of the slopes (agliardi et al., 2001). gravitational compressional structures are also common at the slope toe as bulging reliefs and buckling folds (chigira, 1992). minor landslides occur inside the deformed rocky mass, and ancient collapses develop on the lower parts of slopes. the toes of many dsgsd lie below valley floors and are covered by alluvial or lacustrine fills (agliardi et al., 2012). observations of many dsgsd in the western alps suggest that fractured and loosened bedrock and gravitational surface structures strongly affect the facies and work presented during the aiqua scientific conferences "waiting for the nagoya inqua xix congress", held in florence, june 18 19, 2015 182 forno m.g. et al. distribution of quaternary sediments (forno et al., submitted). the original quaternary cover in dsgsd is usually subjected to strong deformation, dislocation, erosion, and reworking. nevertheless, this research notes that dsgsd locally favour the formation and preservation of quaternary sediments. the present work only emphasizes the local environments that promote the preservation of pre-dsgsd quaternary sequences and the sedimentation and preservation of a new syn-post-dsgsd stratigraphic record. this research considers an example from the gravitational phenomena that occur on the mont fallère southern slope (locally called the “conca del fallère”) along the left side of the middle aosta valley (nw italy), which is drained by the verrogne and clusellaz rivers (fig. 1). this area, which is prevalently located between 3061 and 2000 m a.s.l., comprises the southern slopes of various summits (pointe leysser, mont rouge, mont de vertosan, mont d’ars, mont de la tsa, pointe de chaligne and pointe de metz), the plan di modzon area and the becca france ridge (fig. 2). a traditional geological survey has provided data regarding the outcropping dsgsd structures and quaternary sediments and landforms. geophysical surveys and observations within archaeological excavations have supplied some information regarding buried structures and quaternary sedimentary successions. 2. geological setting the mont fallère area is located in the axial sector of the western alps along the contact between the middle penninic (northern sector) and piedmont zone (southern sector) (fig. 1). the middle penninic is represented by the palaeozoic basement of the gran san bernard nappe. this area consists of garnet micaschist and albitic paragneiss, with some minor bodies of metabasite, and is covered by discontinuous lower mesozoic dolomitic metabreccia and marble. the overlying piedmont zone, which is represented by the upper tectono metamorphic units (as defined by forno et al., 2012a), consists of prevailing carbonate calcschist that alternates with decimetric marble layers. this marble contains many centimetric layers of quartzite, which were probably derived from original chert. few discontinuous layers of meta-rudstone locally occur and consist of marble and dolomite clasts in a calcite matrix. all the rocks in this area were strongly deformed under blueschist metamorphic conditions, followed by widespread recrystallization under greenschist facies metamorphism. the entire area is now completely free of glaciers but was largely shaped by the wide clusellaz glacier during the last glacial maximum (lgm) and lateglacial (fig. 2) (forno et al., 2013b). this glacier previously drained through the clusellaz valley, only subsequently shaping the verrogne valley. the glacial valley floor and the low slopes show many rocky rounded reliefs and associated depressions that are linked to subglacial erosion. these landforms are locally covered by subglacial sediments and glacial marginal deposits, which form short and low lateral moraines. the same glacial valley floor and the low slopes also locally preserve horizontal surfaces, which consist of shallow lacustrine and peat sediments from the lateglacial to the holocene in age. debris, colluvial, avalanche and torrential sediments that formed during the holocene are widely distributed on the bedrock and the more ancient quaternary sequences. bedrock, quaternary cover and landforms have also been fractured, loosened and dislocated by dsgsd structures (fig. 2). the plan di modzon finally preserves ancient settlements (suggested by nine prehistoric sites) from the mesolithic to the copper age, which were hosted in favourable morphological settings as promoted by glacial shaping and dsgsd evolution (raiteri, 2015; forno et al., 2013b). recent studies on the mont fallère southern slope examined the becca france ridge and the plan di modzon area, which were affected by numerous gravitational structures (doubled ridges, minor scarps and trenches) that are linked to the pointe leysser dsgsd, also predisposing a large historical rock avalanche (forno et al., 2012a; 2013a; 2013b; 2014) (fig. 2). geophysical investigations and archaeological excavations have supplied some information regarding the possible evolution of some buried gravitational structures and their influence on lacustrine and palustrine sedimentation (comina et al., 2015). remarks on the p. leysser dsgsd have been reported in the new official geological map (polino et al., fig. 1 schematic geological map of the aosta valley; the investigated area is shown (white box). 183 preservation of quaternary sediments in dsgsd environments ............ in press). the surface evidence of this phenomenon suggests a remarkable sliding of the dora baltea left slope towards the main valley, with an amplitude of approximately 1 km. this map also reports the local sedimentation of travertine, which shows an adequate correlation with dsgsd areas. 3. main gravitational structures and landforms that favored the preservation of quaternary sediments the sliding of bedrock in the upper part of a slope related to dsgsd creates remarkable doubled ridges, which consist of wide depressions that are sub-parallel to the watershed and exhibit lengths up to several kilometres and depths up to tens of metres (agliardi et al., 2001; forno et al., 2012a). the sliding of the bedrock along the entire slope, which often occurs through rotational surfaces, dislocates volumes of rock of varying sizes and forms many minor scarps, which usually exhibit heights greater than ten metres. the sliding surfaces that are observed in the bedrock can also locally preserve gravitational movement striae, which are partially buried by colluvial sediments (fig. 3). the opening of gravitational fractures along a dsgsd slope can result in the genesis of trenches (agliardi et al., 2001). we can distinguish longitudinal and transversal trenches, which essentially develop according to the maximum slope or to the contour lines, respectively (forno et al., 2012b). the evolution of antithetic sliding surfaces in a dsgsd slope can form some counterscarps, which usually create closed depressions (graben). various gravitational structures (doubled ridges, trenches, minor scarps and counterscarps) are widespread in the area (forno et al., 2012a; 2013a; 2013b; 2014). the ensemble of these structures creates a modification from a relatively regular slope to an irregular landscape, completely changing the morphological features of the entire area and giving rise to the following gravitational landforms, which were variously modified by glacial shaping. elongated depressions of varying length (up to hundreds of metres) and depth (up to tens of metres), fig. 2 topographic map of the mont fallère southern slope, or conca del fallère; gravitational structures and archaeological sites (mf1 and mf3) are also reported in the investigated central and southwestern sectors (a). cross section of the plan di modzon; the red box shows the location of geophysical section in fig. 15 (b). 184 which are directly linked to transversal trenches, minor scarps and counterscarps, represent the most common gravitational evidence in the entire area (fig. 4). the glacier usually uses these landforms to modify their original features. closed depressions of varying sizes (up to several hundreds of square metres) are also locally present in the area along the slope and the ancient glacial valley floor (fig. 5). these landforms are directly connected to the gradual development of trenches or linked to the evolution of associated minor scarps and counterscarps, which form graben structures and often host lacustrine and palustrine basins (fig. 6). flat surfaces, which exhibit extensions up to several square kilometres and appear irregular in detail, are common in the investigated area related to the gravitational evolution and extensive subglacial erosion (fig. 7). in detail, gravitational evolution gives rise to many minor scarps, producing an overall enlargement of the topographic surface at the expense of the valley floor space and reducing the overall gradient. glacial shaping often emphasizes this enlargement, creating numerous flat surfaces that are separated by scarps (fig. 8). various dsgsd flat surfaces and scarps show different morphologies (rounded or rough) according to their age, before or after the glacial evolution. rocky rounded reliefs and associated wide depressions are numerous in the ancient glacial valley floors of the area and are related to subglacial erosion that involves the progressively deformed bedrock of dsgsd (fig. 9). the subsequent evolution of the gravitational structures further emphasizes this articulated morphology. these landforms (up to several hundred square metres) hang over the current torrential incisions and are locally cut by deep gorges. in detail, the rounded reliefs are located in less deformed rocks, while the gorges developed along the more fractured and loosened bends (fig. 9). 4. quaternary successions that fill the gravitational landforms the extensively fractured and loosened bedrock and the gravitational structures that are connected to fig. 3 carbonate patinas inhibit the erosion of kinematic indicators on a sliding surface in the bedrock (western slope of the becca france ridge). fig. 4 depression (d) connected to a buried sliding surface with a rotational component (red arrow), partially filled by debris (verrogne valley floor). fig. 5 lago dei morti depression that was shaped by glacial erosion, which is favoured by many minor scarps. fig. 6 morphology of the gravitational closed depression that hosts the filled plan di modzon lacustrine basin. the lake was related to minor scarps and counterscarps that form a graben structure. forno m.g. et al. 185 dsgsd strongly interfere with both erosional and sedimentary phenomena. although the strong deformation of the rocks that promotes heavy subglacial and torrential erosion, quaternary successions can be locally deposited and preserved. 4.1 outcropping successions evidenced by direct observations elongated depressions along transversal gravitational structures, according to the contour lines and not hosting watercourses, are usually preserved over time and are progressively filled with quaternary differentiated successions, which consist of varying types of sediments. the elongated depressions along longitudinal gravitational structures, according to the maximum slope, are not born as fluvial incisions, but instead are usually reused by watercourses and consequently not preserved over time with their original landforms because of deepening. in detail, the transversal depressions that are located in the glacial valley floor of the area are often initially filled by subglacial sediments that directly cover the loosened bedrock (during the lgm and lateglacial) and are subsequently buried by colluvial sediments (during the holocene) (fig. 10a). the quaternary sequence usually consists of a lower body of angular fragments of rock with open texture (debris). faceted pebble and cobble with an abundant over-consolidated sandy-silty matrix (subglacial sediments) cover the debris. crossbedded sub-rounded gravel in a coarse sandy matrix is locally present (proglacial outwash sediments) and alternates with subglacial sediments. the top of the succession consists of small angular fragments of rock with an abundant sandy-silty matrix (colluvial sediments) (fig. 9 in forno et al., 2013b). the transversal depressions that are located along the slopes of the investigated area, laterally to the ice tongue, are usually filled by only debris and colluvium (fig. 10b). the thickness of these successions can vary greatly (up to a few metres) according to the depression size. locally, these morphologies also favoured the prehistoric settlements of the area, with sites built onto the gravitational landforms (fig. 13) that can provide a stratigraphic reference for fracture openings (forno et al., 2013b). closed depressions that are connected to gravitational evolution are progressively filled with quaternary differentiated successions including glacial, lacustrine, palustrine and torrential sediments (fig. 6). the infillings are usually characterized by horizontal morphology (fig. 11). the extremely fractured and loosened bedrock favours the formation of small rocky fragments, which modified the usual fine lacustrine facies (forno et al., submitted). the location of the closed depressions along the slope and the ancient glacial valley floor (outside the current torrential valley floor, where erosion is active) favours the preservation of the infills over time. in detail, the plan di modzon closed depression (1.6 hectares), for example, shows a horizontal morphology in the central sector, where diffusely organic sediments (peat) with planar bedding outcrop (palustrine sediments). laterally, the morphology weakly slopes downstream and exhibits clast-supported sediments that fig. 7 wide, flat, irregular surface on the mont fallère southern slope that is connected to the dsgsd evolution and extensive subglacial erosion. this landform highly hangs from the fig. 8 detail of the wide flat surface on the mont fallère southern slope, which is connected to the evolution of dsgsd during the clusellaz glacier diversion. the glacier, before flowing along the clusellaz valley (on the background), subsequently flowed along the verrogne valley (on the right). a trench and small moraines are visible in the foreground. fig. 9 rocky rounded reliefs, with associated wide depressions, near the mont fallère refuge that hang over the current torrential incisions, observed by se. these features did not experience erosion, which was confined along the gorges fracture in the watercourse (verrogne river in the foreground). preservation of quaternary sediments in dsgsd environments ............ consist of centimetric rocky sub-angular fragments with an abundant sandy-silty matrix (torrential sediments), forming an alluvial fan. this evidence indicates that a palustrine basin developed in this closed depression and was partially filled by a lateral fan. a previous lacustrine basin has only been suggested by geophysical investigations (see § 4.2). in this case, the formation of a lacustrine basin after glacial retreat is related to the typical morphological conditions of scarps and counterscarps, which form a barrier to flow of rivers (fig. 11). in detail, this basin is connected to the formation of nnwsse scarps and wsw-ene counterscarps during the glacial shaping and, subsequently, to the evolution of the same structures without a glacier (comina et al., 2015). an investigated peat bog is hosted in another lacustrine depression upstream from the plan di modzon, which was derived from subglacial erosion that involved the progressively deformed dsgsd area (fig. 2). the lacustrine-palustrine succession that partially fills the bog has been the subject of palaeobotanical research: it suggests a more ancient phase at 11.6 ka cal bp, in which the treeline was lower, and a more recent phase at 8.5-6 ka cal bp, which corresponds to a period of high treeline elevation (pini et al., 2012; badino et al., 2012). these data also suggest a very different environment in this area during the mesolithic and copper age, which is now a wide pasture completely without trees or high shrubs. flat, irregular surfaces also promote the sedimentation of varying types of quaternary sediments, such as subglacial and outwash cover and local palustrine fills (fig. 7). the flat morphology protects these surfaces from the erosion that involves the surrounding steep slopes. this morphology in the investigated area was also promoted by a glacial diversion, with the clusellaz glacier flowing se along the clusellaz valley and subsequently flowing s, shaping the verrogne valley (forno et al., 2014). the same morphology also promoted the ancient population in the area, favouring subsequent prehistoric settlements (forno et al., 2013b) (fig. 2). rocky rounded reliefs and associated depressions that hang over the current torrential incisions also represent areas preserved by erosion (fig. 12). instead, the torrential incisions (gorges) depict strongly eroded areas (fig. 9). the erosional processes are therefore confined within the gorges, which often are the only sectors without ancient sediments. a thin cover of faceted pebbles and cobbles mixed within an abundant over-consolidated silty matrix (matrix -supported subglacial sediments) is usually preserved on the rounded reliefs of the area, which therefore allows the preservation of subglacial sediments over wide areas, and along valley floors, which are subjected in other cases to subsequent torrential erosion. small bodies of sub-angular fragments of varying sizes in a scarce sandy-silty matrix (clast-supported supraglacial sediments) are locally preserved, forming small moraines (fig. 8). additional infills of sub-rounded gravel in a sandy matrix (clast-supported outwash sediments) are usually preserved in the associated depressions. in addition to the described landforms, the dsgsd areas show wide colluvium and debris cover, which is 186 fig. 10 schematic reconstruction of filled gravitational trenches. one depression along a transversal trench in an ancient glacial valley floor (a) was progressively filled by glacial and colluvial sediments, that directly cover the loosened bedrock. another depression along a transversal trench on a slope (b) developed without a glacier and was progressively filled by debris and colluvial sediments. fig. 11 wide horizontal surface that corresponds to the plan di modzon filled lake, bounded by minor scarps (shaped lines) and counterscarps (continuous lines) that form a barrier to the flow of watercourse. forno m.g. et al. linked to the abundant production of rocky fragments from loosened bedrock that only locally outcrops. these areas display a discontinuous travertine cover, which is strictly favoured by gravitational structures (polino et al., in press). strongly cemented quaternary sediments, which are promoted by the high infiltration of surficial water and are related to very fractured and loosened bedrock, are also common. the mont fallère southern slope dsgsd also typically shows wide debris and colluvium cover, with higher thickness in the depressions (fig. 13). erosion that is linked to surface runoff mainly affects this cover, which buries and consequently partially preserves more ancient quaternary sediments. a locally developed travertine cover is visible along the p. leysser southern slope (fig. 2). it outcrops for example at the outlet of a deep incision, which corresponds to a longitudinal trench that was subsequently deepened by an ephemeral watercourse (fig. 14). in detail, 3.5 m-thick travertine (phytohermal calcareous tufas) with 30° towards the sse dipping stratification covers debris flow sediments (fig. 14). this travertine is very rich in trees imprints (trunks and branches) with decimetric sizes. this sequence, which is characterized by a strong resistance to erosional phenomena, has protected the underlying debris flow sediments. another outcrop of travertine, which has a subvertical arrangement and is over one metre thick, is visible along the detachment niche of the becca france rock avalanche. this travertine preserves the debris and colluvial sediments that fill the fractures (fig. 2). other carbonate-cemented sediments are also observed along the entire mont fallère southern slope, where quaternary sediments are usually very strongly cemented. this feature facilitates their preservation by erosion. the dsgsd structures often promote the carbonate-cementation of sediments under favourable climatic conditions. this cementation is favoured by strong infiltration, through loosened bedrock, also connected to the facies of different sediments that are particularly rich in small rocky fragments and scarce matrix. 4.2. buried successions as evidenced by geophysical investigations geophysical surveys can be very useful to study the buried fills of the described landforms and to evaluate the features and thicknesses of various sedimentary bodies. geophysical surveys (i.e., electric tomography) that have been performed along the fallère southern slope allow us to evaluate the thickness of the quaternary cover and reconstruct the facies of different sediments (comina et al., 2015 in which details on the geophysical data acquisition and processing can be found). this methodology was applied to an elongated depression less than 1 metre deep, which is located in the ancient verrogne glacial valley floor and is connected to gravitational minor scarps and associated counterscarps through the prehistoric human site mf3 (fig. 13). a resistivity section shows that the high resistivity, which is related to the bedrock of the valley floor (values above 2000 ohm.m), is truncated by lowresistivity anomalies with a sub-vertical trend (at progressive 60 and 80 m) (fig. 15a a-a1 stretch). these 187 fig. 12 typical morphology of the plan di modzon with rocky rounded ridges (r) and associated wide depressions, which were connected to the progressive evolution of fractures, trenches, minor scarps and counterscarps during glacial erosion. steps a and b refer to different glacier thicknesses; step c refers to the development of a watercourse in a fracture after glacier retreat. fig. 13 archaeological site (mf3) during the excavation phase. the site is located in an approximately 1 m deep elongated depression, resulting from associated minor scarps (slopes dipping to the right) and counterscarps (only identified by geophysical investigations), partially filled by glacial and colluvial sediments (verrogne glacial valley floor). preservation of quaternary sediments in dsgsd environments ............ features are probably related to the presence of less compacted material that likely contains higher water content. the collected geophysical data and related geological interpretations suggest that the first anomaly (at 60 m) represents a buried depression that is elongated in the nnw-sse direction (as indicated by field work data) and bounded by minor sliding surfaces that dip in opposite directions (normal and antithetic) (fig. 15b a-a1 stretch). this depression appears to be filled by a coarse and successively fine cover, which is interpreted as glacial and colluvial sediments, respectively. the second anomaly (at 80 m) has been referred to as a main antithetic sliding surface due to dsgsd’s evolution, which dips to the wsw and is relatively continuous in the subsoil. geophysical research in the investigated area also suggests that a closed depression in the plan di modzon hosts complex sequences of varying sediment types (between 70 and 180 m) (fig. 15a b-b1 stretch; fig. 16a) (comina et al., 2015). in detail, a succession of subglacial silty-gravel sediments (values between 500 and 750 ohm.m), lacustrine sands (values between 300 and 500 ohm.m) and local palustrine organic deposits (peat and gyttja with values between 150 and 300 ohm.m) can be distinguished (fig. 15b b-b1 stretch; fig. 16b). the resistivity data also indicate that the closed depression is truncated in the sse portion of the section (fig. 16) by a dsgsd-buried surface. this scarp likely represents the prolongation in the subsoil of outcropping counterscarps (see § 4.1). 4.3. buried successions evidenced by archaeological excavations a prehistoric human settlement (site mf3) that was discovered by an archaeological excavation (raiteri, 2015) allows us to directly observe the surficial succession filling within an elongated depression (fig. 13) that is mainly related to gravitational minor scarps and associated counterscarps. the excavation exposed a sequence whose bottom consists of glacial boulders with a subordinate grey sandy matrix, forming a subglacial body. yellowish-brown silty sand covers this body, which is referred to as a colluvial layer because of the reworking of glacial sediments by surface runoff (fig. 17). several artifacts of rock crystals (hyaline quartz) from the middle neolithic have been found above the colluvial body. in this example, the colluvial body buries the coarse glacial sediments, pro 188 fig. 14 local occurrence of a travertine cover (yellow and grey colour), which is significant for the preservation of more ancient debris flow sediments (grey colour) (p. leysser southern slope). fig. 15 geophysical cross section (a) and related geological interpretation (b) of the investigated area. the a-a1 stretch exhibits associated minor scarps and counterscarps that are partially filled by glacial and colluvial sediments, on which a prehistoric settlement was located (site mf3). the b-b1 stretch indicates a subglacial, lacustrine and palustrine succession in the filled ancient lake. the black arrow refers to the cross section in fig. 16. modified after comina et al. (2015). forno m.g. et al. moting their preservation. numerous other sites developed on the bedrock’s rounded ridges, showing a thin subglacial cover. in detail, site mf1, which was discovered by an archaeological excavation, represents more typical and studied prehistoric evidence (raiteri, 2015). this site was developed on a cover that consists of sediments with faceted boulders within a sandy-silty matrix that is connected to a subglacial environment. the yellowish colour of this cover suggests incipient weathering to form slightly evolved soil. detailed research on this site indicates a complex stratigraphy marked by the younger settlement (copper age) at the base of the sequence and older mesolithic artifacts at the top. the copper age layer shows remarkable traces of settlement and use (rubefied areas and charcoal accumulations), which are superimposed by a hearth that preserves a large amount of charcoal inside a cuvette that is delimited by lithic fragments. charcoal remains provide radiocarbon ages of 4306 ± 45 14c a bp (3030-2870 yr bc) and 3983 ± 40 14c a bp (2620-2400 yr bc) (raiteri, 2015). mesolithic artifacts (approximately 3000) are obtained from rock crystals and subordinate flint (forno et al., 2013b). the more significant retouched artifacts (94) indicate a probable sauveterrian phase. some doubleback, back, cutting and triangular artifacts are the most indicative and a charcoal remain provides a radiocarbon age of 7795 ± 45 14c a bp (6700-6490 yr bc) (raiteri, 2015). their most ancient age indicates that these artifacts were carried by a colluvial phenomenon, which was responsible for their reworking leading to a secondary arrangement. consequently, this settlement exhibits a reversed sequence that consists of in place more recent archaeological evidence that is covered by more ancient reworked (colluviated) materials. 5. discussion and conclusions generally, the preservation of a sedimentary stratigraphic record occurs in areas of active sedimentation and little or no erosion. as known, gravity plays an important role in the sedimentation and erosion on the earth’s surface, strictly because of local morphology. in detail, an increase in topographic elevation and steepness promotes erosional processes. conversely, depositional processes, which favour the development of a stratigraphic record, are more developed with decreasing steepness and topographic elevation. this feature, which is evident in sea basins, is also observed in continental environments, which contain a high variability of sectors that are characterized by prevalent erosion or sedimentation and little extension. deep-seated gravitational slope deformations (dsgsd) usually produce strong deformation both within the bedrock and quaternary cover, generally favouring erosion and gravitational reworking and producing a thick and widespread debris and colluvium cover that usually buries every structure and landform. however, the gravitational collapse of a mountain side and its resulting expansion in the valley floor occur in dsgsd areas, with the topographic surface consequently expanding. these processes lead to the reduction of the average steepness of the slope and the development of a very irregular topographic surface, which creates local environments with slower or absent ero 189 fig. 16 geophysical cross section (a) and related geological interpretation (b) indicating that the plan di modzon represents a closed depression that was filled by sediments. the resistivity values suggest the occurrence of subglacial and lacustrine sediments below the surficial palustrine and torrential cover. the local low resistivity values in the bedrock below the closed depression is consistent with buried trenches. the black arrow refers to the cross section in fig. 15. modified after comina et al. (2015). preservation of quaternary sediments in dsgsd environments ............ sional processes, where sedimentation and the preservation of a quaternary stratigraphic record can develop. recent observations of many dsgsd in glacial valleys in the western alps allow us to distinguish the typical effects of these phenomena on the facies and distribution of quaternary sediments (forno et al., submitted). an example of the dsgsd effects on the sedimentation and preservation of quaternary successions has been presented in this research, with a focus on the mont fallère southern slope in the middle aosta valley. these effects on the outcropping quaternary sediments, dsgsd structures and landforms were derived from traditional geological surveys. notes on buried structures and successions were also obtained by means of geophysical surveys and observations of archaeological excavations. this research suggests that dsgsd can locally favour the sedimentation and preservation of the oldest successions, in areas that usually experience erosion, for the following reasons. first is the occurrence of wide, flat, irregular surfaces (fig. 7), in which various quaternary successions can easily be deposited and protected from erosion, which instead particularly develops along the surrounding steep slopes. moreover, the typical irregular morphology of dsgsd, which are characterized by rocky rounded reliefs and associated wide depressions that hang over the current torrential incisions (fig. 9), favours the local sedimentation and preservation of a quaternary stratigraphic record. these sediments are instead completely eroded in torrential incisions that developed along the main fractures, that are subsequently deepened by watercourse. dsgsd structures further favour the development of environments where sedimentation processes are active. in detail, many elongated depressions (connected to gravitational transversal trenches or minor scarps and associated counterscarps) form very local sedimentation basins in which various quaternary successions can be easily deposited and preserved. on the contrary, the depressions that are linked to longitudinal trenches, subsequently used by the current watercourses, and then deepened and partially filled by torrential and debris flow sediments, usually do not preserve evidence of more ancient fillings, with the exception of debris flow sediments that are preserved by travertine. furthermore, the local occurrence of closed depressions along the slope and glacial valley floor (because of gravitational trenches or minor scarps and associated counterscarps that gradually evolve) are occupied by lakes after glacial retreat. these depressions are progressively filled by essentially lacustrine, palustrine and torrential successions, which are subsequently preserved by erosion because they are not deepened by the current watercourses. the reported geophysical data allow us to better image the preserved stratigraphic record and observe gravitational structures that are not visible on the surface through traditional geological surveys. the typical conditions of dsgsd areas promoted the development of prehistoric human settlements. the morphology usually comprised flat, irregular surfaces, which favoured the formation and preservation of prehistoric mountain sites, which also provides a chronological reference for sediments and landforms. these conditions that favour ancient settlements are also observed in the investigated area. nine mountain sites have been recognized in the plan di modzon area and are located on glacial rounded reliefs with associated wide depressions (fig. 9) (forno et al., 2014). the reported glacial diversion created a very wide flat surface, which favoured the development of prehistoric settlements. these ancient settlements were also favoured by the location of the area near the treeline and the absence of geological hazards (floods, landslides, and avalanches) that are present in surrounding areas. the prehistoric settlement mf3 was likely favoured, in addition to its proximity to water, by the location of the depression in the valley floor, which was perched approximately 10 m from the filled plan di modzon lacustrine basin. the prolonged use of the mf1 site, as indicated by archaeological artifacts of varying ages, confirms the suitability of the plan di modzon to preserve archaeological stratigraphic records. finally, as reported, the sedimentation and preservation of the quaternary stratigraphic record was encouraged by the strong fracturing of the bedrock related to dsgsd. this fracturing favoured well known processes as: a) the production of large amounts of debris and colluvium, which covered more ancient sediments and landforms; b) a decrease in erosional processes from surficial runoff, which was caused by the high permeability of the very fractured bedrock; and c) the percolation of water in the strongly fractured rocks, which promoted the dissolution and deposition of carbonates and, consequently, the active sedimentation of chemical rocks and cementation of older quaternary successions. the trenches, minor scarps and counterscarps that developed in these dsgsd areas further favoured the development of environments where subsidence prevailed and sedimentation processes were active. in conclusion, dsgsd conditions can promote both the local preservation of quaternary pre-deformational successions and the formation of many localized records that consist of syn-deformational and post-deformational sediments. 190 fig. 17 archaeological excavation of site mf3, which shows a succession of coarse glacial sediments (grey) and fine colluvium (yellow, visible in the central part of the picture) (verrogne glacial valley floor). forno m.g. et al. forno m.g., gattiglio m., gianotti f., guerreschi a., raiteri l. (2014) la percezione del paesaggio di alta montagna da parte dell’uomo preistorico: l’esempio dell’area di plan di modzon nella conca del fallère (valle d’aosta, italia nordoccidentale). atti del convegno “dialogo intorno al paesaggio”, perugia, 19-22 febbraio 2013. cultura territori e linguaggi, univ. perugia, 4(2), 233-245. forno m.g., gattiglio m., gianotti f., lo russo s., taddia g. (submitted) dsgsd effects on the quaternary sediment facies and distribution: examples from the western alps (nw italy). bull. eng. geol. environ. hutchinson j.n.(1988) general report: morphological and geotechnical parameters of landslides in relation to geology and hydrogeology. proceedings of the 5th international symposium on landslides, july 10-15, 1988, lausanne, 1, 3-35. pini r., aceti a., maggi v., orombelli g., raiteri l., ravazzi c. (2012) holocene forest history and timberline fluctuations in the western and central alps: the role of climatic factors and men. in: abstracts of aiqua congress “the transition from natural to anthropogenic-dominated environmental change in italy and the surrounding regions since the neolithic”, february 15-17, 2012, pisa (italy). polino r., bonetto f., carraro f., gianotti f., gouffon y., malusà m.g., martin s., perello p., schiavo a. (in press) note illustrative del foglio 90, “aosta”, carta geologica d’italia alla scala 1:50.000. ispra serv. geol. it. raiteri l. (2015) popolamento umano ed evoluzione del paesaggio alle pendici del mont fallère (saint pierre, valle d’aosta) nell’olocene antico e medio. tesi di dottorato di ricerca in scienze e tecnologie per l’archeologia e i beni culturali, università degli studi di ferrara, pp. 297. sorriso-valvo m. (1995) considerazioni sul limite tra deformazione gravitativa profonda di versante e frana. mem. soc. geol. it., 50, 179-185. varnes d.j., radbruch-hall d., varnes k.l., smith w.k., savage w.z. (1990) measurement of ridgespreading movements (sackungen) at bald eagle mountain, lake county, colorado, 1975-1989. u.s. geological survey open-file report, 13, 90543. acknowledgements the authors are grateful to the amq editorial staff for the useful suggestions. we thank also two anonymous reviewers for improving the manuscript. references agliardi f., crosta g., zanchi a. (2001) structural constraints on deep-seated slope deformation kinematics. eng. geol., 59(1-2), 83-102. agliardi f., crosta g., frattini p. (2012) slow rockslope deformation. landslides type, mechanisms and modeling. clague j.j. and stead d. eds., 207221. ambrosi c., crosta g. (2006) large sackung along major tectonic features in the central italian alps. eng. geol., 83, 183-200. badino f., pini r., ravazzi c. (2012) torbiere e paludi in valle d’aosta: un archivio per la vegetazione, la biodiversità, i ghiacciai, la preistoria dell’uomo. environment, 56, 36-39. chigira m. (1992) long-term gravitational deformation of rock by mass rock creep. eng. geol. 32(3), 157184. comina c., forno m.g., gattiglio m., gianotti f., raiteri l., sambuelli l. (2015) ert geophysical surveys contributing to the reconstruction of the geological landscape in high mountain prehistorical archaeological sites (plan di modzon, aosta valley, italy). it. journ. geosc., 134, 1, 95-103. cruden d.m., varnes d.j. (1993) landslides investigation and mitigation. landslide types and processes. transportation research board, nat. ac. sci., 247, 1-77. forno m.g., gattiglio m., gianotti f. (2012a) geological context of the becca france historical landslide (aosta valley, nw italy). alp. mediterran. quatern., 25(2), 125-139. forno m.g., lingua a., lo russo s., taddia g. (2012b) morphological features of rodoretto valley deepseated gravitational slope deformations. am. journ. environ. sci., 8(6), 648-660. forno m.g., lingua a., lo russo s., taddia g., piras m. (2013a) gstop: a new tool for in field recording of 3d geological data. europ. journ. remote sensing, 46, 234-249. forno m.g., gattiglio m., gianotti f., guerreschi a., raiteri l. (2013b) deep-seated gravitational slope deformations as possible suitable locations for prehistoric human settlements: an example from the italian western alps. quatern. intern., 303, 180-190. ms. received: december 10, 2015 final text received: august 22, 2016 191 preservation of quaternary sediments in dsgsd environments ............ 192 << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /none /binding /left /calgrayprofile (dot gain 20%) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /error /compatibilitylevel 1.4 /compressobjects /tags /compresspages true /convertimagestoindexed true /passthroughjpegimages true /createjobticket false /defaultrenderingintent /default /detectblends true /detectcurves 0.0000 /colorconversionstrategy /cmyk /dothumbnails false /embedallfonts true /embedopentype false /parseiccprofilesincomments true 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/hrv (za stvaranje adobe pdf dokumenata najpogodnijih za visokokvalitetni ispis prije tiskanja koristite ove postavke. stvoreni pdf dokumenti mogu se otvoriti acrobat i adobe reader 5.0 i kasnijim verzijama.) /hun 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can be opened with acrobat and adobe reader 5.0 and later.) >> /namespace [ (adobe) (common) (1.0) ] /othernamespaces [ << /asreaderspreads false /cropimagestoframes true /errorcontrol /warnandcontinue /flattenerignorespreadoverrides false /includeguidesgrids false /includenonprinting false /includeslug false /namespace [ (adobe) (indesign) (4.0) ] /omitplacedbitmaps false /omitplacedeps false /omitplacedpdf false /simulateoverprint /legacy >> << /addbleedmarks false /addcolorbars false /addcropmarks false /addpageinfo false /addregmarks false /convertcolors /converttocmyk /destinationprofilename () /destinationprofileselector /documentcmyk /downsample16bitimages true /flattenerpreset << /presetselector /mediumresolution >> /formelements false /generatestructure false /includebookmarks false /includehyperlinks false /includeinteractive false /includelayers false /includeprofiles false /multimediahandling /useobjectsettings /namespace [ (adobe) (creativesuite) (2.0) ] /pdfxoutputintentprofileselector /documentcmyk /preserveediting true /untaggedcmykhandling /leaveuntagged /untaggedrgbhandling /usedocumentprofile /usedocumentbleed false >> ] >> setdistillerparams << /hwresolution [2400 2400] /pagesize [612.000 792.000] >> setpagedevice late quaternary evolution of the terni basin, central italy: new geoarchaeological data milena bertacchini dipartimento di scienze della terra, università di modena e reggio emilia, modena e-mail: milena.bertacchini@unimore.it abstract: bertacchini m., new geoarchaeological data on the recent evolution of the terni basin, central italy. (it issn 0394-3356, 2009). because of an archaeological find of part of a hellenistic city wall (ca 5th -3rd century bce) a well-preserved 10 m thick fluvial sequence was studied close to the centre of the town of terni, in an area of central italy (umbria) where the geological outcrops are generally scarce. this study was made in a large excavation for a building that permitted direct observation of the sediments that filled the terni basin and provided a step forward in our knowledge of its geoenvironmental evolution. the sedimentary sequence was deposited by a segment of the ancient nera river-course (paleo-nera) in the late pleistocene-early holocene and its presence is correlated with the development of the first human settlements in the town of terni. this fluvial sequence shows evidence of a low-sinuosity gravel meander system consisting of transverse gravel bars and gravel sheets in its lower part, that are capped by a 5 m thick levee unit and overbank deposits interbedded with incipient paleosols and a crevasse channel unit. the floristic composition contents in the paleosols of the overbank sequence provide important information on the climatic transition from the late glacial to the holocene. the upper part of the sequence, a paleosol dated with archaeological remains to roman times, contains important elements that aid in understanding the development of the first phases of urbanisation of the ancient town of terni. riassunto: bertacchini m., nuovi dati sull’evoluzione recente della piana di terni (italia centrale). (it issn 0394-3356, 2009). lo scavo ad uso civile realizzato nel sito di corso del popolo, nei pressi del centro storico di terni, ha permesso la diretta osservazione di una potente successione sedimentaria di ambiente fluviale deposta a partire dal tardo pleistocene da un antico tratto del fiume nera (paleo-nera). lo studio di dettaglio condotto sulla successione esposta ha rappresentato una importante opportunità per la raccolta di nuove informazioni sull’evoluzione geologico-ambientale recente del bacino di terni, attraverso indagini di tipo geologico-sedimentologico, mineralogico-petrografico, paleontologico e pollinico, affiancate da dati archeologici. la base della successione è rappresentata da sedimenti ghiaiosi di canale attivo passanti a depositi di esondazione con sequenze di argine, di canale di rotta e di canale di crevasse, intervallati da paleosuoli interessati da una pedogenesi poco evoluta. la variazione del contenuto pollinico registrata all’interno dei depositi di esondazione è da imputare al cambiamento climatico legato alla fine del tardi-glaciale ed all’inizio dell’olocene. l’abbandono del canale fluviale favorisce la formazione di un lago poco profondo o acquitrino e la deposizione di sedimenti carbonatici fini interrotti a tetto da un paleosuolo archeologicamente riferibile al i sec. a.c. i dati stratigrafici e cronologici ottenuti dallo studio della sequenza investigata concorrono a ricostruire con maggior puntualità la situazione geo-ambientale che accompagnò le prime fasi di urbanizzazione della città di terni. keywords: fluvial deposits, paleosols, holocene, terni, central italy. parole chiave: depositi fluviali, paleosuoli, olocene, terni, italia centrale. il quaternario italian journal of quaternary sciences 22(2), 2009 249-256 introduction the terni plain is located in the southern part of the umbria region, within the central and terminal sectors of the nera river basin (fig. 1). it is a transition area between the inner apennine chain and the hills and plains of the western regions of italy in the tiber valley (southern and northern etruria). the stratigraphy of the continental deposits filling the terni basin is not well-known because of the scarcity of useful outcrops. the entire continental succession, which characterises the recent sedimentary deposition of the plain, is largely hidden below the surface. most of the detailed subsurface geological data collected has come from archaeological or civil excavations and the results of recent studies of the sediments in the terni basin (be r t a c c h i n i et al., 2006; fa z z i n i & ma f f e i, 2006) have not permitted a recognition of the continuous stratigraphic succession, mainly formed by lacustrine and fluvial-lacustrine sediments, deposited from the vii century bce until roman times. in this framework the sequence here studied is fundamental for the knowledge of the sediments filling the terni basin and for better understanding both the geoenvironmental evolution of the plain and the development of the first human occupation in the centre of terni. the terni plain has continuously been a major communication and trade passageway since the bronze age, because of its morphological and strategic geographical location (giontella, 2006). the town of terni was formally founded in the 672 bce (bonomi ponzi, 2006), even though the oldest significant phase of its urban development was in the 3 rd century bce, in coincidence with the roman expansion in the umbria region (pe r i s s i n o t t o, 2006). the ancient name of terni, interamna nahars, means “between two rivers”, was given because its position at a confluence of the nera river with the serra-tescino stream suggesting a different hydrographic layout at that time. several authors have hypothesized that both streams have probably changed their courses through time (grassini, 1947; fontaine, 1990; fazzini & maffei, 2006), on the basis of archaeological data (fig. 1). this paper presents the data obtained of a verti250 m. bertacchini cal sequence of sediments exposed by a civil excavation (over 50 m wide) conducted in summer 2006 along corso del popolo road, close to the centre of terni, which has given us an insight as to the morphologic grounding of this newly founded city in its earliest days. geological setting the terni plain is one of the fault-bounded intermontane basins formed during the plioquaternary succession of tectonic phases in an extensional regime, which affected the central portion of the northern apennine chain (ba r c h i et al. , 1991; ca t t u t o et al., 1992; ca v in a t o et al., 1993; br o z z e t t i & lav e c c h i a, 1995). accordingly, the elongated nne-ssw shape of the terni basin results from the complex interaction of the martani, sabini and val di serra fault systems boardering the plain (bo n i n i, 1997; gi r o t t i & ma n c i n i, 2003). the terni basin is considered to be the western elongation of the tiber basin, an intermontane apenninic depression that was gradually filled with fluvial and lacustrine deposits (lo t t i, 1917; li p p i bo n c a m b i, 1960; am b r o s e t t i et al., 1978; ba s i l i c i, 1993; am b r o s e t t i et al., 1995; co n t i & gi r o t t i, 1977; girotti & mancini, 2003). a shallow lake or pond system occupied the terni basin up to earliest historical times that gradually disappeared due to the alluvial infill from the nera, serra and tescino streams (bertacchini et al., 2006; fazzini & maffei, 2006). the terni basin is flanked by martani-reatini mountains to the east and amerini-narnesi-sabini mountains to the west. these higher areas consist of calcareous meso-cenozoic units of the umbria-marche marine succession, where the headwaters of the nera river and its main tributaries are located (the aia and serra-tescino streams and the bianco-caldaro brook). the predominance of carbonate rocks in this apennine area greatly control the composition of the sediments transported by the watercourses into the terni basin as well as the groundwater composition of the region. methods preliminary data here presented results from a sedimentological and physical study of the sediments in order to integrate the detailed visual inspection of the deposits and define the lithostratigraphical sequence. these data are a combination of: lithology, grain size, sedimentary structures, colour and any other possible diagnostic element. colour definitions, such as 2.5 y 5/4, are referred to munsell colour soil chart and consists of hue (2.5 y), lightness (5), and chroma (4). ams (accelerator mass spectrometry, nelson et al. 1977; bennett et al. 1977) radiocarbon datings have been carried out from carbon organic remains in the beta analytic inc. laboratory in miami, florida. the datings refer to the intcal04 calibration data set for terrestrial samples (reimer et al., 2004). the first results on paleontological (macro and micro) and pollen characters cited in this paper have been supplied by personal communications respectively from a. russo and s. marvelli. the paleontological samples have been treated with h2o2 (2% vol.) and the observations have been carried out on a dry residue, sieved and desiccated in oven at 105 °c. the pollen analysis have been carried out following the standard procedure described by lowe et al. (1996) in the archaeoenvironmental giorgio nicoli laboratory in bologna. the micromorphological study on paleosol thin sections have been examined under the optical microscope applying the methods of stoops (2003) and some terminology of bu l l o c k et al. (1985) and br e w e r ( 1 9 7 6 ) . mineralogical analyses on pebble coatings observed in the sequence have been conducted by energy-dispersive x-ray (edx) technique coupled with an environmental scanning electron microscope esem quanta-200 in the modena university cigs laboratory. the sedimentary sequence of the corso del popolo site this study is based on observations made during the excavation of the corso del popolo car park located fig. 1 morphological and geographical location of the town of terni. this map contains the present-day hydrographic system and the stream-course changes both of the nera river, according to this study and that of fontaine (1990), together with data concerning the serratescino stream, according to grassini (1947), fontaine (1990) and fazzini & maffei (2006). the confluence of the serra-tescino stream with the nera river during medieval times has been suggested by grassini (1947) and fontaine (1990). ubicazione geografica della città di terni e rappresentazione cartografica semplificata del suo territorio. nella mappa è ricostruita la paleoidrografia dei principali corsi d’acqua dell’area: il fiume nera, sulla base dei risultati presentati in questa ricerca e dei dati pubblicati da fontaine (1990); e i torrenti serra e tescino, come riportato da grassini (1947), fontaine (1990) e fazzini & maffei (2006). near the centre of terni, not far from the present-day course of the nera river. the examined section has permitted the reconstruction of a 10 m thick sedimentary succession, which was deposited by the watercourse antecedent to the modern nera. a detailed multidisciplinary stratigraphical investigation has been carried out based on geological, mineralogical, petrographicalmicromorphological and paleontological evidences along with pol len and archaeological data. four main different units have been recognized in the investigated sequence. unit a, at the base of the excavation, consists of a 3 m thick sedimentary sequence mainly composed of gravel with subordinate pebbly-sand and sand. this unit, whose lower limit is not exposed, abruptly passes to a finer deposit of the overlying unit b. the sedimentary structures observed in these deposits are mainly represented by trough-shaped and planar cross-beds, which develop in a meterlong continuous sets. the gravels are generally moderately sorted. they are composed of rounded to subrounded calcareous and cherty, medium to large pebbles, ranging 1÷3 cm (mean diameter). units of single depositional events are in sets about 40 cm thick and an angle of about 20°, suggesting a main watercourse flow from ne to sw. the gravels are clastsupported with less than 10% smaller sized clasts of sand and mud as matr ix. pebbles are coated by a reddish-black thin iron-manganese film and there is very litt le matr ix between the clasts. horizontally bedded gravel sheets are present in the upper portion of unit a. they are formed of rounded medium to very large pebbles and subordinate cobbles, slightly imbricated. they appear as moderately sorted, graded, clast-supported deposits with subordinate sand and mud. unit b overlies unit a and is formed by a 5 m thick 251late quaternary evolution of the terni basin, central italy: ... sequence consisting of a well-developed cyclicity, which is cadenced by dark brown levels presenting pedogenic modification. each cycle is characterized by a basal sandy unit overlain by a pedogenised horizon of coarser-grained sediment (b1) or of finer-grained sediment (b2). each simple pedofacies sequence (kr a u s, fig. 2 stratigraphic section studied in the corso del popolo site of the terni basin. the different units are described in text. a: unit a, related to coarse-grained point bar deposits; b: unit b, an overbank sequence formed of levee (b1) and crevasse-splay (b2) sediments interbedded with floodplain deposits; unit c, a crevasse channel deposit; c: unit d, sequence due to a cut-off event. ricostruzione della successione stratigrafica del sito di corso del popolo a terni. sono indicate le diverse unità come descritte nel testo. a: unità a, caratterizzata da sedimenti ghiaiosi di canale attivo; b: unità b, depositi di esondazione con sequenze di argine (b1) e di canale di rotta (b2) intervallati da paleosuoli interessati da una pedogenesi poco evoluta; c: unità c: deposito di canale di crevasse; d: unità d, depositi dovuti alla formazione di un lago poco profondo o acquitri no conseguente all’abbandono del canale fluviale. 252 1987) is capped by the base of the ensuing cycle with little or no erosion; except the top of unit b, which was truncated by the erosive deposition of unit c (fig. 2). the simple pedofacies sequence (b1) is made of coarsening-upward cycles of fine sandstones and siltstones showing weakly identifiable ripple-cross lamination and matrix-supported graded gravel deposits formed of brown-reddish pebbles and cobbles. the gravel levels have been affected by pedogenic modification including root structures, scattered desiccation cracks and mottling. these pedofeatures have also been examined in a thin section where, when mottling is present, there is a clearly visible considerable scattered enrichment in interstitial oxides of iron and manganese. this weakly developed pedogenic modification has been observed in the gravel layers of b1 in association with unaltered parent material characterized by sandstones, siltstones and lithic fragments. the lowest gravel layer in b1 has been studied in greater detail to obtain a better understanding of the relations between unit b and the underlying unit a. the finer sediment in the lower part of this horizon is dark brown (7.5 yr 3/2-4) and yellow brown mottled (10 yr 5/6), passing to yellow-reddish brown mottled (7.5 yr 5/6) in the upper part. the second and relative younger dark brown (10 yr 4/2) gravel layer in b1 (fig. 2) is indicated by prevalent amounts of pedogenic modification that is, however, more immaturely developed; mottling is observed but desiccation cracks are not present. a determination of the absolute age through asm radiocarbon dating has yielded a value of 9310±50 bp (10660-10310 cal bp; beta-238366). the pollen data of the base of b1 have revealed a moderate presence of deciduous oaks with f r a x i n u s in an open landscape and a high content of non-arboreal pollen (cichorioideae). at the top of b1, arboreal vegetation u n d e rwent a clear reduction, without disappearing completely. the simple pedofacies sequence b2 overlies b1; it is formed by fining upward cycles of laterally discontinuous exposure sheet-like siltstones and very-fine sandstones, interspersed with dark-coloured pedogenised mudstones (10 yr 5/2; 4/2). each cycle of sandy layers capped by a single paleosol is repeated at least six times moving upward b2, with a range in thickness of each one from 0.4 to 1 m. no erosional surfaces are observed between two subsequent cycles, passing upward b2. the last cycle at the top of b2, and corresponding to the top of unit b, is truncated and eroded by a channelized-shape gravel deposit (unit c). in general, the sediment forming the base of each series consists of a beige-coloured (10 yr 6/4; 7/2-4; 8/4-6) calcareous sandy siltstone or fine sandstone that passes upwards to a fine siltstone. the primary structures are generally not preserved but, where identifiable, they present cross and horizontal lamination. the top of each cycle is dominated by crumbly calcareous mudstones on which a single paleosol profile (freytet, 1973), with an immature pedogenic evolution, develops. these paleosols present dark brown coloured zones with burrowing, root traces, rare calcite nodules, and bacterial concretions. the micromorphological data confirm the pedofeatures observed in outcropping and show the correlation between root traces and calcite nodules, when the nodules are present. the paleosol of the uppermost cycle b2 was not truncated, and lies at the base of the gravel channelized-shape deposit. it is the only horizon to show rare papulae pedofeatures (brewer, 1976) in a thin section. this deposit has a radiometric age of 8010±40 bp (9010-8730 cal bp; beta-238365). an appreciable vegetation change occurred at the beginning of the deposition of the simple pedofacies sequence b2, mainly due to the early appearance of tilia and salix, while the landscape was still fairly open. moving upward along the sequence, the pollen content increases, both in quantity and diversity of species; the deciduous oaks accompanied by several other arboreal taxa (fraxinus, tilia, carpinus, pinus, salix, alnus ecc.) define a forested landscape. the upper part of unit b is engraved and eroded by a coarse-grained channelized-shape deposit, here indicated as unit c (fig. 2). unit c appears as a lens, a few meters wide and one meter thick, with gentle flanks and an erosive concave base. the channel-filling is formed by moderately sorted to well sorted graded coarse to pebbly sands up to pebble gravels. the finer sediments at the base of the channel present ooids and tubular bacterial structures and show trough cross bedding (mi a l l, 1996). penetrative rhizolite laminar calcretes are present, due to the calcification around roots (wr i g h t et al., 1995). these are 3-5 cm thick and 40 cm long and develop along the main cross-bedding surfaces. they correspond to beige calcareous cementation normally developed around root mats and show alveolar septal structures in a thin section (wright et al., 1995). a pebble to cobble gravel sheet closes the coarsening upward channel-filling and exhibits a slightly convex shape. unit d constitutes a 4 m thick sequence characterized by calcareous, gold-coloured (10 yr 8/2-3), fine siltstones with faintly planar lamination at the base. this deposit continues at the base of the upper section examined at the corso del popolo site. in about two meters of thickness it is possible to observe siltstones or mudstones with ostracods and pulmonate gastropods (in course of determination), bioturbation, root tubules and carbonate concretions. at the top of the sequence there is a yellow brown (2.5 y 5/4) mottled paleosol containing archaeological remains that accumulated before the 1s t century bce (superintendence to archaeological properties of umbria, personal communication). an important structure, part of a huge wall of hellenistic age (5t h3r d century bce) has been found above the muddy sandstones with ripple lamination on the northern side of the site excavation. the presence of significant human exploitation of the corso del popolo area since that time has probably contributed to erase all other parts of that wall. interpretation integrating lithological, sedimentological, mineralogical aspects with physical evidence and paleontological and pollen data, allows us to reconstruct a reasonable picture of the alluvial environment where the continental studied succession accumulated. each unit is related to characteristic depositional processes. m. bertacchini 253 unit a shows sediments and sedimentary structures deposited by fluvial processes in an alluvial plain, probably due to the accumulation of lag deposits within transverse gravel bars and horizontal beds (lithofacies gp, gt and gh of mi a l l, 1996). according to jackson (1976), gu s t a v s o n (1978) and mi a l l (1996), this sequence is probably related to a coarse-grained point bar deposit characterized by lateral accretion and gravel bedform elements. extensive continuous sets of trough cross-strata are interpretable as due to a moderately stable bar related to a gravel-bed wandering fluvial system (as h m o r e, 1991; wo o l d r i d g e & hi c k i n, 2005). such an important supply of coarse-grained gravelly sediments requires the effects of intense physical weathering processes and extreme ranges in fluvial discharge to favour their deposition. post-depositional movement of fluids through the sediments also caused intense fluid washing with a concomitant removal of most fine-grained sediment, therefore little matrix remains. unit b shows a coarsening-upward simple pedofacies sequence at the bottom (b1), which is overlaid by a fining-upward simple pedofacies sequence (b2), both are interbedded with incipient paleosols. unit b developed in a floodplain area proximal to the active channel. it corresponds to a vertical sequence of overbank environments constituted by progressive sandy levee (b1) and crevasse-splay (b2) sediments associated with finer-grained floodplain deposits. the passage between unaltered fluvial sediments and paleosols is apparently related to an alternating succession between periods of flood events and periods of quiescence without fluvial sedimentation. the sequence b1 suggests relatively rapid accretion rates on the basis of poorly developed pedogenic modification. the paleosol at the base of this unit can be interpreted as an entisol that, even though immature, testifies to a slight decrease in the sedimentation rate (kraus, 1987). the strong presence of burrowing, rooting and calcite nodules as pedogenic features in the paleosols observed in the sequence b2, hints that the deposition of new sediments were relatively frequent over a period of time but sufficiently infrequent as to permit the triggering of such aspects of pedogenic modification. the pollen assemblage of the lowest part of b1 is interpreted as representing a semi-arid and cool phase where moderate deciduous oaks dominated the open landscapes. the marked vegetational reduction recorded at the top of b1 suggests a worsening of the severe climatic conditions. moving upward b2, a significant vegetational change is marked. the appearance of tilia and salix at the base and a significant expansion of tilia and various other tree taxa at the top of the sequence, evidence a more temperate and humid climate than in the previous phase. unit c marks a limited erosive event, which cut the top of unit b sequence. it is characterized by a coarse-grained lens deposited by a crevasse channel, which probably is correlated to the sediments of the cut-off event of unit d. the penetrative rhizolite laminar calcretes, which occurred as calcareous cementation around root mats, suggest a carbonate-rich groundwater environment associated to an increase of temperature, which favoured the calcium-carbonate precipitation. unit d is associated with a shallow lake, pond or marshy environment overlies a structure that represents a probable cut-off process from the active streamchannel (sm i t h et al., 1989; wi l l i s & be h r e n s m e y e r, 1994; miall, 1996). unit d represents the beginning of a new geoenvironmental situation favouring the development of a shallow carbonate lacustrine-palustrine environment related to a shallow, fresh-water lake (platt & wright, 1992) and a more humid climate. this interpretation is also based on the first results obtained from fossil species present in the sediments at the bottom of unit d. the degree of pedogenic modification increases upwards in the sequence. discussion of the results the sediments and sedimentary structures observed in the corso del popolo fluvial succession on the terni plain are representative of an ancient stream course, flowing on the eastern side of the present-day town of terni. the collected data suggest that this stream acted as an ancient segment of a paleo-nera river located close to the west of the present-day course of the nera river. this geological result proves the change in the nera river-course originally hypothesised by fontaine (1990) on the basis of archaeological speculations (fig. 1). the studied sequence represents a rare example of a continuous succession deposited from the late ple istocene-early holocene up to roman times observed in the terni basin. fig. 3 hypothesis of reconstruction of the oldest defensive wall built around the centre of terni during the 5th-3rd century bce (mod. zampolini faustini, 2006) schema ricostruttivo della cinta muraria a difesa dell’antica città di terni tracciato sulla base del rinvenimento del tratto di muro ascrivibile al v-iii sec. a.c. citato nel testo (mod. zampolini faustini, 2006). late quaternary evolution of the terni basin, central italy: ... 254 the detailed analysis of the sedimentary succession show an interesting geoenvironmental evolution of the basin, passing from a coarse-grained point bar sequence deposited by a low-sinuosity fluvial system (unit a), grading to an overbank succession composed of levee deposits (b1) and crevasse-splays (b2), cyclically interrupted by immature paleosols. a crevasse channel (unit c) truncates the overbank deposits and marks the transition to a shallow lacustrine-palustrine environment related to a cut-off event. the ams radiometric dating determined at the base of unit b links the visible part of unit a to the effects of the final phases of the last glacial portion of late pleistocene (bu s s c h e r s et al., 2007), which favoured the large supply of the coarse-grained sediments forming unit a. a late glacial climatic situation which is comparable with the last glacier advance of the gran sasso massif in the central apennines dated by giraudi & frezzotti (1997) at ca. 11000 yr b.p. the sequence of the overbank deposits (unit b), in spite of their laterally discontinuous exposure, suggests that deposition occurred in a relatively proximal position with respect to the paleo-nera river-channel, starting from 9310±50 bp (10660-10310 cal bp). the overbank sequence was generated by sporadic flood events followed by pedogenesis, which was periodically interrupted by crevasse-splay deposition until 8010±40 bp (9010-8730 cal bp), when a crevasse channel (unit c) cut the sequence and ended the overbank deposition. the pollen assemblage and the forest reduction recorded in the lower part of unit b is related to a semiarid and cool phase. this was successive the marked vegetational fluctuation proved at rieti basin (ri c c i lu c c h i et al., 2000) and at lagaccione, near lago di bolsena, until a few centuries after 10850±105 yr b.p. (magri, 1996), and which the authors consider related to the younger dryas event. the vegetation associated to the upper part of unit b suggests a progressive considerable forest expansion, which is interpretable as due to a more temperate and humid climate. the increase of arboreal plants marks the transition to holocene as observed in other sites of central italy (fo l l i e r i et al., 1989; calderoni et al., 1994; watts et al., 1996; magri, 1999; magri and sadori, 1999; ricci lucchi et al., 2000). palustrine-shallow lacustrine and calcareous sediments close the corso del popolo sequence (unit d) were deposited in a cut-off shallow lake or pond environment related to a temperate wet climate, where the rising temperature was favourable to the deposition of the calcium-carbonate. similar environmental conditions are documented at rieti basin (ricci lucchi et al., 2000), lagaccione (ma g r i, 1999) and lago di vico (magri & sandori, 1999) during the interval 8000-7000 yr bp. the environmental changes recorded in the sediments of the terni sequence from the middle holocene were a consequence of climatic changes affected by regional and local factors. it is more difficult to put forward a reconstruction hypothesis based on the scarce remains of the wall of hellenistic age (ca 5t h 3r d century bce) found at the corso del popolo site. this wall apparently represented a portion of the eastern side of the oldest defensive wall built around the town of terni, at the beginning of its roman political organization (fig. 3). conclusions fluvial systems may contain important archives for improving the understanding of present and past landscape stability. the wide fluvial sequence of the corso del popolo site on the terni plain is an unusual occasion to observe a well-preserved sediment record of an ancient course of nera river starting from the late pleistocene. detailed analyses of the geometry and internal lithological variation of the fluvial succession, as well as the pedogenic features and pollen assemblages of alluvial paleosols in the overbank deposits, have permitted a more detailed reconstruction of the recent geoenvironmental evolution of the terni plain to be improved and, meanwhile, some historical and archaeological speculations concerning the ancient hydrographic system of the town of terni to be addressed, even in a humble site such as a future car-park. considering the vertical evolution of the sedimentary sequence recorded in terni, it is possible to relate the sedimentological and ecological evidences observed to significant changes in climatc conditions due to the transition between the last phases of late glacial times and the more temperate and humid beginning of the holocene. these results are in agreement with the records from other sites in central italy: valle di castiglione (fo l l i e r i et al. , 1989), lago lungo (calderoni et al., 1994), lago albano (lowe et al., 1996), lagaccione (ma g r i, 1999), lago di vico (ma g r i & sadori, 1999), rieti (ricci lucchi et al., 2000). the terni site can be considered an important archive of paleoenvironmental and paleoclimate record for the global climatic transition from the end of the last glacial times to the beginning of holocene, while the ensuing climatic changes recorded in the sediments were progressively affected by regional and local environmental factors. acknowledgements i wish to thank laura bonomi ponzi of the superintendence to archaeological properties of umbria who made this research possible, and terni corso del popolo spa which supported the work. i am grateful to b.c. schreiber for constructive comments and the revision of the manuscript and to d. brunelli and d. fontana for useful suggestions. paleontological data were carried out by antonio russo (university of modena and reggio emilia); pollen analysis was realized by marco marchesini and silvia marvelli (laboratorio archeoambientale-centro “g. nicoli”, bologna). references ashmore p.e. (1991) how do gravel-bed rivers braid? canad. jour. ear. sc., 28, pp. 237-293. ambrosetti p., basilici g., capasso barbato l., carboni m. bertacchini g., di stefano g., esu d., gliozzi e., petronio c., sardella r. & squazzini e. (1995) il pleistocene inferiore nel ramo sud-occidentale del bacino tiberino (umbria): aspetti litostratigrafici e biostratigrafici. il quaternario, 8(1), pp. 19-36. ambrosetti p., carboni m.g., conti m.a., costantini a,, es u d., ga n d i n a., gi r o t t i o., la z z a r e t t o a . , mo z z a n t i r., ni c o s i a u, pa r i s i g. & sa n d r e l l i f . (1978) evoluzione paleogeografia e tettonica nei bacini tosco-umbro-laziali nel pliocene e nel pleistocene inferiore. mem. soc. geol. it., 19, pp. 573-580. barchi m., brozzetti f. & lavecchia g. (1991) analisi strutturale e geometria dei bacini della media valle del tevere e della valle umbra. boll. soc. geol. it., 110, pp. 65-76. basilici g. (1993) sedimentary facies in an extensional and deep-lacustrine depositional system: the pliocene tiberino basin, central italy. sed. geol., 109, pp. 73-94. be n n e t t c.l., be u k e n s r.p., cl o v e r m.r., go v e h . e . , li e b e r t r.b., li t h e r l a n d a.e., pu r s e r k.h. & sondheim w.e. (1977) radiocarbon dating using electrostatic accelerators: negative ions provide the key. science, 198, pp. 508-510. be r t a c c h i n i m, ma r c h e s i n i m., ma r v e l l i s . (2006) risultati preliminari sull’evoluzione paleoambientale e paleoclimatica del sito archeologico di maratta bassa (terni). in: angelelli c., bonomi ponzi l. (a cura di) “terni interamna nahars. nascita e sviluppo di una città alla luce delle più recenti ricerche archeologiche” collection de l’ècole française de rome, 362, roma, pp. 95-107. bonini m. (1997) evoluzione tettonica plio-pleistocenica ed analisi strutturale del settore centro-meridionale del bacino tiberino e del bacino di rieti (appennino umbro-sabino). boll. soc. geol. it., 116, pp. 279-318. bo n o m i po n z i l . (2006) i n t r o d u z i o n e. in: angelelli c., bonomi ponzi l. (a cura di) “terni interamna nahars. nascita e sviluppo di una città alla luce delle più recenti r icerche archeologiche” collection de l’ècole française de rome, 3 6 2, roma, pp. 1-17. brewer r. (1976) fabric and mineral analiysis of soils. robert e. krieger publishing company, new york, 482 pp. br o z z e t t i f. & la v e c c h i a g . (1995) evoluzione del campo degli sforzi e storia deformativa nell’area dei monti martani (umbria). boll. soc. geol. it., 114, pp. 155-176. bu l l o c k p., fe d o r o f f n., jo n g e r i u s a., st o o p s g . , turbina t. & babel c. (1985) handbook for soil thin section description . waine research publication, albrighton, 152 pp. busscher f.s., kasse c., van balen r.t., vandenbergh j., co h e n k.m., we e r t h.j.t., wa l l i n g j., jo h n s c., p. cl e v e r i n g a & bu n n i k f . p . m . (2007) l a t e pleistocene evolution of the rhine-meuse system in the southern north sea basin: imprints of climate change, sea-level oscillation and glacioisostacy. quat. science rev., vol. 26 (25-28), pp. 3216-3248. ca l d e r o n i g., ca r r a r a c., fe r r e l i l., fo l l i e r i m . , gl i o z z i e., ma g r i d., na r c i s i b., pa r o t t o m . , sadori l. & serva l. (1994) paleoenvironmental, paleoclimatic and chronological interpretations of a late-quaternary sediment core from piana di rieti (central apennines, italy ). giornale di geologia, 56 (2), pp. 43-72. ca t t u t o c., gr e g o r i l., me l e l l i l., ta r a m e l l i a. & tr o i a n i c . (2002) paleogeographic evolution of the terni basin (umbria, italy). boll. soc. geol. it., vol. spec. 1, pp. 865-872. cavinato g.p. (1993) recent tectonic evolution of the quaternary deposits of the rieti basin (central apennines, italy) southern part . g e o l o g i c a romana, 29, 411-434, roma. co n t i m.a. & gi r o t t i o . (1977) i l villafranchiano nel “lago tiberino”, ramo sud-occidentale: schema stratigrafico e tettonico. geol. rom., pp. 16, 6780. fontaine p. (1990) cités et enceintes de l’ombrie antique. bruxelles-roma, pp. 11-130. fazzini p.† & maffei m. (2006) appunti di geologia e geomorfologia della conca ternana. in: angelelli c., bonomi ponzi l. (a cura di) “terni interamna nahars. nascita e sviluppo di una città alla luce delle più recenti ricerche archeologiche” collection de l’ècole française de rome, 3 6 2, roma, 57-62. follieri m., magri d. & sadori l. (1989) pollen stratigraphical synthesis from valle di castiglione (roma). quat. int., 3–4, pp. 81–84. freytet p. (1973) petrography and paleo-environment of continental carbonate deposits with particular reference to the upper cretaceous and lower eocene of languedoc (southern france). sed. geol., 10, pp. 25-60. giontella c. (2006) l’abitato di maratta (campagne di scavo 2001-2002). in: angelelli c., bonomi ponzi l. (a cura di) “terni – interamna nahars. nascita e sviluppo di una città alla luce delle più recenti ricerche archeologiche” collection de l’ècole française de rome, 362, roma, 78-93. gi r a u d i c. & fr e z z o t t i m . (1997) late pleistocene glacial events in the central apennines, italy. quaternary research, 48, pp. 280–290. girotti o. & mancini m. (2003) plio-pleistocene stratigraphy and relations between marine and non marine succession in the middle valley of the tiber river (latium, umbria). il quaternario, 1 6 8( 1 b i s ) , pp. 89-106. grassini p. (1947) delimitazione dell’antica terni secondo scoperte archeologiche. boll. deputazione storia patria per l’umbria, vol. xliv, pp. 34-38. gu s t a v s o n t . c . (1978) bed forms and stratification types of modern gravel meander lobes, nueces river, texas. sediment., 25, pp. 401-426. ja c k s o n r.g. ii (1976) depositional model of point bars in the lower wabash river. j. sediment. petrol., 46, pp. 579-594 kr a u s m . j . (1987) integration of channel and floodplain suites, ii. vertical relations of alluvial paleosols. j. sediment.petrol., 57 (4), pp. 602-612. lippi boncambi c. (1960) umbria. bibliografia geologica d’italia, vol. 7, xv. c.n.r., roma, 102 pp. lo t t i b . (1917) l’antico lago tiberino e le ligniti dell’umbria. la miniera italiana, 7(1), pp. 274-275. lowe j.j., accorsi c.a., bandini mazzanti m., bishop a., 255late quaternary evolution of the terni basin, central italy: ... va n d e r ka a r s s., fo r l a n i l., me r c u r i a . m . , rivalenti c., torri p. & watson c. (1996) pollen stratigraphy of sediment sequences from crater lakes albano and nemi (near rome) and from the central adriatic, spanning the interval from oxygen isotope stage 2 to the present day. mem. ist. it. idrobiol., 55, 71-98. magri d. (1999) late quaternary vegetation history at lagaccione near lago di bolsena (central italy). rev. paleob. palynol., 106 (3-4), pp. 171-208. ma g r i d. & sa d o r i l . (1999) late pleistocene and holocene pollen stratigraphy at lago di vico (central italy). veg. hist. archaeobot., 8, 247-260. mi a l l a . d . (1996) the geology of fluvial deposits. springer-verlag berlin heidelberg, 582 pp. ne l s o n, d.e., ko r t e l i n g r.g. & st o t t w . r . (1977) carbon-14: direct detection at natural concentrations. science, 198, pp. 507-508. perissinotto c. (2006) la delimitazione e la difesa di interamna nahars in età medievale. in: angelelli a. e bonomi ponzi l. (a cura) terni i n t e r a m n a nahars. nascita e sviluppo di una città alla luce delle più recenti ricerche archeologiche. école française rome, pp. 271-307. platt n.h. & wright v.p. (1992) palustrine carbonates and the florida everglades: towards an exposure index for the fresh-water environments. journal sedimentary petrology 62, pp. 1058-1071. re i m e r p.j, ba i l l i e m. g.l., ba r d e., ba y l i s s a., be c k j.w., be r t r a n d c. j.h., bl a c k w e l l p.g., bu c k c.e., bu r r g.s., cu t l e r k.b., da m o n p . e . , ed w a r d s r.l., fa i r b a n k s r.g., f.m., gu i l d e r s o n t.p., ho g g a.g., hu g h e n k.a., kr o m e r b . , mcco r m a c g., ma n n i n g s., ra m s e y c.b., re i m e r r.w., re m m e l e s., so u t h o n j.r., st u i v e r m . , ta l a m o s., ta y l o r f.w., va n d e r pl i c h t j . , we y h e n m e y e r c.e. (2004) intcal04 terrestrial radiocarbon age calibration, 0-26 cal kyr bp. radiocarbon, 46 (3), pp. 1029–1058. sm i t h n.d., cr o s s t.a., du f f i c y j.p. a n d cl o u g h s . r . (1989) anatomy of an avulsion. sedimentology, 36, pp. 1-23. st o o p s g . (2003) guidelines for analysis and description of soil and regolith thin section. soil science society of america, madison, 184 pp. wa t t s w.a., al l e n j.r.m., hu n t l e y b. & fr i t z s . c . (1996) vegetation history and climate of the last 15,000 years at laghi di monticchio, southern italy. quat. sci. rev. 15, pp. 113–132 willis b.j. & behrensmeyer a.k. (1994) architecture of miocene overbank deposits in northern pakistan. j. sediment. res., b64, pp. 60-67. wooldridge c.l. & hickin e.j. (2005) radar architecture and evolution of channel bars in wandering gravel-bed rivers: fraser and squamish rivers, british columbia, canada. jour. sediment. res., 75, pp. 844-860. wr i g h t v.p., pl a t t n.h., ma r r i o t s.b. & be c k v . h . (1995) a classification of rhizogenic (root-formed) calcretes, with examples from the upper jurassic-lower cretaceous of spain and upper cretaceous of southern france. sedimentary geology, 100 (1-4), pp. 143-158. zampolini faustini s. (2006) topografia ed urbanistica di interamna nahars tra vecchi dati e nuove scope r t e. in: angelelli a. e bonomi ponzi l. (a cura) terni interamna nahars. nascita e sviluppo di una città alla luce delle più recenti ricerche archeologiche. école française rome, pp. 141-161. 256 ms. ricevuto il 23 aprile 2008 testo definitivo ricevuto il 28 ottobre 2008 ms. received: april 23, 2008 final text received: october 28, 2008 m. bertacchini amq28(2)121-129 moscon rivisto 12_2015.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 28 (2), 2015, 121 129 very-high resolution analysis of a transgressive deposit in the northern adriatic sea (italy) giorgia moscon¹, annamaria correggiari², cristina stefani¹, alessandro fontana¹, alessandro remia² ¹dipartimento di geoscienze, università degli studi di padova, padova, italy ²istituto di scienze marine cnr, bologna, italy corresponding author: g. moscon <giorgia.moscon@studenti.unipd.it> abstract: the adriatic sea is characterized in the northern and central shelf by different generation of isolated transgressive bodies formed and drowned in-place during the last relative sea-level rise. the continental shelf is characterized by a low gradient and, within the transgressive deposits the episodic variations in sea level and sediment supply caused the formation of backstepping parasequences. the transgressive bodies have been studied in detail because they have considerable amount of sorted sand exploitable for beach nourishment. a transgressive deposit, located south of the po delta, offshore ravenna at depth of 34-35 m, has been investigated with a total coverage of very-high resolution (vhr) seismic profiles and high number of cores in order to understand the stratigraphic evolution during the late quaternary sea-level rise. the transgressive body is composed of four seismic units separated by high-amplitude and high continuity reflectors, corresponding to peat and organic-rich layers indicating different depositional phases. the core analysis confirmed the presence of different units showing sediment variation from clay with peat-layer at the base to fine-grained sand at the top of the deposit. furthermore, the core analysis gave information about the thickness of the deposit. the thickness of the transgressive body is from 3 to 5 m and each unit varies from 1 to 2 m. in particular, the sand portion reached a maximum thickness of 1.5 meters. the seismic analysis and the digital elevation model constructed for key surfaces highlighted the channel system direction was towards ene during last glacial maximum and during sedimentation of unit 1 and 2, while it shifted toward ese during the formation of unit 3. moreover, to constrain the chronology of the sedimentary evolution, some peat and organic-rich samples, have been dated with 14c method. these organic horizons are evident seismic reflectors and correspond to key surfaces. they are characterized by brackish lagoon facies and could be a proxy indicator for the relative paleo-sea level. along with the previous data, they indicated that the sedimentation of the studied transgressive body occurred around 10,000 cal. a bp. keywords: quaternary, sea-level rise, sequence stratigraphy, beach nourishment, chirp-sonar 1. introduction the late glacial and holocene (post 18,000 a) sealevel rise is well recorded in the adriatic sea due to the peculiar physiographic and sedimentary setting of the basin (correggiari et al., 1996). during the last sea-level rise the northern adriatic sea was characterized by the formation of different generation of barrier-lagoon systems. these bodies, drowned in-place and partly preserved, crop out in the northern adriatic seafloor as elongated build-ups parallel to the present coastline. they are interpreted as patches of ancient coastal wedges which have considerable amount of sorted sand and are a significant resource exploitable for beaches nourishment. the sand portion of the transgressive deposits has been studied in detail with grain-size analysis, petrographic analysis, sedimentary architecture and volumes calculation in order to use this resource for coastal nourishment. the detailed characterization of a transgressive deposit located south of the po delta, through very-high resolution seismic profiles and facies analysis can shed new lights on the formation and evolution of the transgressive deposits. in particular, as the formation of the transgressive bodies is strongly related to the changes of relative sea level, their multidisciplinary study can produce important data in the reconstruction of the past relative position of the sea level (antonioli et al., 2009) and detect centennial fluctuations. 2. geological setting 2.1. the adriatic sea the adriatic sea is an epicontinental semienclosed basin (fig. 1) surrounded by three thrust-andfold-belts: the ne-verging apennines, the s-verging southern alps and the sw-verging dinarides. the basin records the evolution from a passive margin, during the fig. 1 location of the study area in the adriatic sea. bathymetry and superficial geology modified from the geological map of italian seafloor (fabbri et al., 2001; trincardi et al., 2011 a, trincardi et al., 2011 b). mesozoic, to a foreland basin system, during the cenozoic (d’argenio & horvath, 1984; ori et al., 1986; ciabatti et al., 1987; argnani & frugoni, 1997). during quaternary sea-level fluctuations the basin has been shaped by huge change of the oceanographic regime and sedimentary dynamics (trincardi et al., 1994, 1996). during the last glacial maximum (lgm, 30,000-19,000 14c a bp; lambeck & purcel, 2005; clark et al., 2009) the sea-level was about 120-130 m lower than today and the northern continental shelf was completely in subaerial conditions (fig. 2a). in this environment several river networks formed, consisting of by a main trunk river (paleo po river) and alpine and apennines tributaries; the fluvial system terminated in a low-stand delta located at the northern edge of the meso-adriatic-depression, southeast of ancona (de marchi, 1922; correggiari et al., 1996; ridente & trincardi, 2005). during the late-glacial to early -holocene transgression, a glacio-eustatic, non-steady sea-level rise of approximately 120 meters caused substantial basin widening coupled by changes in energy regimes across the basin (cattaneo & steel, 2003) (fig. 2b). the low gradient of the northern adriatic shelf, together with the sea-level rise (approximately 10-15 mm/a), favoured the deposition and drowning of different generations of transgressive barrier-lagoon system sedimentary bodies. in contrast, the steeper topographic gradient of the southwestern adriatic shelf has been characterized by the deposition of thick transgressive progradational deposits (cattaneo & trincardi, 1999; maselli et al., 2011). the maximum marine ingression was reached ca. 5500 cal. a bp when the basin occupied much wider area than during the low-stand (fig. 2c). during highstand the anticlockwise circulation characterizing the adriatic caused southward transport of sediment along the entire western side of the basin as documented in surficial geology maps of the adriatic (fabbri et al., 2001; trincardi et al., 2011 a; trincardi et al., 2011 b) (fig. 1). our study focused on a transgressive deposit, located 50 km from ravenna at 34-35 m water 122 moscon g. et al. fig. 2 widening of the adriatic basin during the last transgressive cycle. (a) sea-level during the last glacial maximum (lgm), an extensive portion of the adriatic sea was in subaerial condition, while the meso-adriatic-depression (mad) was a semi-enclosed basin receiving high amount of sediment (correggiari et al., 1996). (b) rapid sea-level rising after the lgm. (c) maximum marine ingression reached 5500 cal. a bp. fig. 3 main cores facies description. (a) simplified log of most representative cores. the tst deposits rest on the transgressive surface. the paralic deposit is characterized at the base by clay sediment, peat and organic-rich layers and at the top by a sand portion. this deposit ends with ravinement surface. (b) example of cores facies. 1: peat layer; 2: interbedded clayey and silty layers; 3: sand portion; 4: ravinement surface (rs). depth (fig. 1). this transgressive deposit showed a dominant longshore trend parallel to the modern coastline, it extends ns for about 20 km and is 8 km wide. its thickness varies from 1 m near the boundary areas to 4 meters in the depocenters. 2.2. transgressive deposits the late-glacial and holocene transgressive deposits (transgressive system tract, tst) in the adriatic basin were formed by backstepping barrier-lagoon and incised valley systems in the low gradient northern shelf, while mud sedimentary bodies thicker than 25 m are present in the central adriatic shelf (cattaneo & trincardi, 1999; maselli et al., 2011, trincardi et al., 2013) (fig. 1). the tst rests on an erosive surface of regional extent (transgressive surface, ts) that truncates older low-stand deposits (lst), and is below the maximum flooding surface (mfs) (fig. 3). available 14c data show that the time interval encompassed by the tst spans about 11,000 years, between 16,000 and 5500 cal. a bp (correggiari et al., 1996; trincardi et al., 1996; cattaneo & trincardi, 1999, correggiari et al., 2001, maselli et al., 2011). the transgressive deposits in the northern adriatic shelf are located at sea bottom between -45 m to -10 m water depth, and they are preserved as elongated undulating elevations almost parallel to the present coastline. the complex geometry and their preservation is probably due to a combination of different factors such as the rate of sea-level rise, the low gradient of the shelf and the coastal dynamics (belknap & kraft, 1981, correggiari et al., 2011). in the northern adriatic sea, transgressive deposits are generally associated to a barrierlagoon system, that is typically characterized by clayeysilty lagoon deposits associated with sandy beach deposits (fabbri et al., 2001) (fig. 3). 3. methods the transgressive deposit has been examined with a multi-disciplinary approach through very high resolution (vhr) seismic profile analysis and vibrocorer samples, digital elevation model (dem) of most significant surfaces and 14c dating. all the analysed data have been collected during oceanographic cruises carried out in the last 20 years by cnr-ismar onboard urania r/ v. vhr seismic profiles have been acquired with sub bottom profiler chirp-sonar with 16 low-frequency transducers. about 750 km of vhr seismic profiles, oriented ns and spaced 120 meters each other, covered the transgressive deposit (fig. 4a). the seismic profiles have been processed and interpreted with seisprho (gasperini & stanghellini, 2009). cores have been collected by vibrocorer rossfelder p5, with a vibrating head and a steel corer 6-m long and 10-cm wide. dems of key seismic surfaces, obtained from conversion tools ascii to raster of arcmap 10.1 software, have been used to map their areal distribution. furthermore the top of the transgressive deposit, coinciding with the seafloor, has been analysed with the digital elevation model of the multibeam bathymetry (with image resolution of 10 m) acquired during the nad12 (in 2012) oceanographic cruise onboard urania r/v (fig. 4b). the device used is an em 710 multibeam echosounder with 70-100 khz. the geochronological constrains of the geological evolution have been provided by the 14c dating of 3 samples of organic-rich and peat layers, in the core ar00_22. the ams analysis has been done at the ion beam laboratory at the eth institute in zurich. our data have been integrated with those from core cm94_107 (fabbri et al., 2001). the radiocarbon ages from ar00_22 and cm94_107 cores have been calibrated using calib14 radiocarbon calibration program of stuiver & reimer (1993). the results have been corrected for isotopic fractionation, but no correction for oceanic reservoir was made because the dated layers are of terrestrial origin. 4. results 4.1. seismic analysis the seismic profiles analysed, were collected during the oceanographic cruises nad12. the detailed seismic-stratigraphic analysis highlighted three different seismic facies: 1) a semi-transparent unit, due to scarce penetration of the acoustic signal, indicative of sandy sediments, characterized by an irregular, erosive base; 2) an interbedded transparent seismic facies with parallel and subparallel irregular and discontinuous reflectors related to fine-grain deposits with thin fine sand or silty layers; 3) regular and continuous reflectors interpreted as peat and organic-rich layers. in each profile five key surfaces have been identified and traced in order to define the geometry of deposits and to investigate the formation and evolution of the transgressive parase 123 reconstruction of a transgressive deposit fig. 4 study area detail. (a) tracks of vhr seismic profiles, acquired in 2012, covering the study area. (b) seafloor bathymetry (image resolution of 10 m). evidence of the ese channel system trend. quences. the key surfaces, easily visible and traceable along the entire profile, correspond to organic rich and peat layers. the seismic reflector interpreted as transgressive surface marks a different response in the seismic profile and has been traced correlating the dated peat layers from published data (fabbri et al., 2001; correggiari et al., 2011). the ts is an erosional surfaces that marks the first major flood of the margin. it rests on the low-stand deposit formed during the lgm where the top was dated at 20,000-21,000 14c a bp by radiocarbon dating of peat samples southern than the investigated deposit by trincardi et al. (1994); fabbri et al. (2001); cattaneo & steel, (2003). the studied transgressive body rests on the ts. in addition to the ts other three key reflectors have been identified within the transgressive deposit (a surface, b surface, c surface and seafloor surface at the top, fig. 5); these surfaces border four different units (from unit 1 at the base, to unit 4 at the top) that mark four different depositional environments during the sedimentation of the transgressive deposit (fig. 5). moreover within the most recent unit an additional key surface has been identified at the base of the sandy portion. the unit 1, 2 and 3 were delimited by the digitized key surfaces, corresponding to peat layers, and were characterized by interbedded transparent and discontinuous seismic reflectors, which were more regular within the unit 3. at the top of both the unit 1 and the unit 2 seismic profiles revealed the presence of some channels bordered by levees. the unit 4, was delimitated at the base by the c key surface and at the top by the seafloor. additional key surface within unit 4 divided the base with irregular and discontinuous seismic reflectors and at the top a semitransparent seismic facies indicative of sandy sediments. 4.2. digital elevation models of key surfaces the digital elevation models showed the morphology of the surfaces highlighting the occurrence of the channel system network existing when each of them was exposed and active (fig. 6). thus, each dem represents one step in the formation of the transgressive deposit. the ts lies higher to the west and lower towards east, characterized by channels with ene direction (fig. 6a). at first, the sedimentation over the ts occurred in the north/northeast and western areas and shows an ene channel progradation. this situation was highlighted by the dem of the a surface (top of the unit 1) and the dem of the b surface (top of the unit 2) (fig. 6b/c), and then the sedimentation of the transgressive fig. 5 evidence of the key surfaces and units within the sedimentary transgressive body. 124 moscon g. et al. body shifted to the south/southwest. the dem of the c surface (top of the unit 3) highlighted the filling of the southern area together with the variation of the channel direction from ene to ese (fig. 6d). the transgressive body ended at the top with unit 4, that correspond to the basal clay lagoon layer resting on the c surface, filling and flattening the transgressive body. the seafloor bathymetry (fig. 4b), that coincides with the top of the unit 4, maintained the same ese channel trend as highlighted for unit 3. 4.3. cores facies analysis and calibration of seismic units 30 cores collected during the oceanographic cruises cm94 and ar00 (in 1994 and 2000) onboard urania r/v (cnr-ismar) have been described to define the depositional environment corresponding to the sedimentation of the transgressive body. the cores had a length spanning between 1.5-4 m and generally showed coarsening-upward trend with a thin finingupward layer at the top. the basal portion was formed by clay with some peat layers. this unit was overlain by fine-sand that was capped by an erosional surface. the tst deposit was covered with thin layer (about 15-30 cm) of silty-clay representing a recent distal po prodelta highstand deposit (correggiari et al., 2005; correggiari et al., 2011) (fig. 3). the unit 1 rests on the transgressive surface and is capped by the a surface (fig. 5), it was found only in the northern part of the investigated area and it is organized in elongated river systems that are elevated above the ts and oriented towards ene. these systems lie on the ancient fluvial system highlighted by the ts, and in the seismic profiles it was possible to recognise some leveed channel systems. the unit 1 was mainly formed by clay with organic matter and millimetric plant debris interbedded with peat layers (fig. 7), farther few cores highlighted a fine-sand to silty layer at the top of this unit. the fossil content belonging to this unit was characterized by the mollusc association consisting of cerastoderma glaucum, abra segmentum and lentidium. the unit 2 was bounded at the base by the a surface and at the top by the b surface (fig. 5), it was mainly present in the northern and western part of the investigated area and it filled the depressed zones formed between the unit 1 channel systems. this unit was similar to the unit 1, characterized by clay with organic matters and carbonaceous frustules, while the top was an easily recognizable layer of peat with a thickness of 10-15 cm (fig. 7). the fossil content was the same as of the unit 1. the unit 3 was bounded at the base by the b surface if present or by the ts surface where it was not present and at the top by the c surface (fig. 5). unit 125 125 reconstruction of a transgressive deposit fig. 6 dems with isopach of the key surfaces obtained from conversion tools ascii to raster of arcmap 10.1 program. comparison of dem. variation in channel system trend and preservation of each unit. the channels depicted in each surface have been traced in blue, while the dashed rivers represent the leveed channel systems elevated above the underlying surface. 3 was mostly developed in the southern part of the area, while in the northern sector was limited to a thin layer below the unit 4. the southern portion of the unit 3 was characterized by 2-2.5 meters of clay layers with millimetric plant debris interbedded with parallel-laminated silty layers (fig. 7). the northern portion of the unit 3 was formed of a thin layer of clay that filled and smoothed the underlying depressed areas. the paleontological association was characterized by cerastoderma glaucum, abra segmentum and lentidium sp. the unit 4 was bounded at the base by the c surface and at the top by the seafloor (fig. 5), its geometry showing two convex landforms with a gentle trough in the middle of the deposit. in this unit a significant amount of sorted sand has been found within the two build ups above a thin clayey layer. the sand portion, that reached up to 1.5 m of thickness, ended with a bioclastic sand layer representing the ravinement surface (rs) (fig. 7). the analysis on the sand below the rs showed a mean diameter between 0.25-0.35 mm and a very scarce content of silt and clay (correggiari et al., 2011). the top of the deposit is locally characterized by a very thin 15-30 cm layer of clay. 5. discussion the combined seismic and core analyses allow us to reconstruct the evolution of the transgressive deposit. the four units, forming the transgressive body, show different environment of sedimentation. the basal units (unit 1, unit 2 and unit 3), consisting of silty-clay sediment with organic matter and interbedded peat layers, are indicative of lower delta plain environments with distributary channels and lagoon. the paleontological content, recognized in clay layers belonging to unit1, 2 and 3, is indicative of euryhaline association of bivalves peculiar of transitional environment from fresh to brackish water. the more recent unit (unit 4) consists of basal thin layer of clays formed in a lagoon environment, covered by two plano-convex bodies of basal beach sand. this unit represents a patch of barrier-lagoon system capped by the ravinement surface formed by bioclastic sand. the combined study of seismic profiles and cores emphasizes a marked difference between the basal and the superficial portion of the deposit in terms of sedimentary environment and preservation potential. the buried units, belonging to an inner coastal environment 126 moscon g. et al. fig. 7 ar00_22 core log plotted on nad216 seismic profile, location in fig. 5 . on the left, the picture shows the position of ar00_22 in the seismic profile, the seismic units in color bordered by the key surfaces. on the right, the picture shows the description of the ar00_22 core, their core facies, highlighted by the photos, corresponding to the white panels a, b, c, d close to the core log. compared to the unit 4, indicate back-barrier environment. the analysis of the seismic profiles highlighted a local aggradation of the unit 1, 2 and 3 that filled the morphological depressions inherited from of the previous topography. on the contrary, unit 4, which was strongly affected by marine processes, was characterized by erosion and reworked sediment, as highlighted by the ravinement surface. the comparison among dems of the surfaces confirmed limited erosion in units 1, 2 and 3, while marked reworking occurred at the top of unit 4. the buried units were characterized by erosion due to the activity of washover fans or fluvial floods, while unit 4 was subjected to shallow marine processes such as wave activity. moreover, the seafloor dem, which shows the present bathymetry, highlights that the path of channels is in relief. this setting suggests differential erosion within unit 4 with the removal of softer or less stiff sediment. 127 reconstruction of a transgressive deposit tab. 1 radiocarbon and calibrated dating from cm94_107 (fabbri et al. 2001) and ar00_22 cores. fig. 8 a: depth vs. age plot. in blue are represented the adriatic 14c data from composite table in antonioli et al. (2009) and from geological map of the italian sea (fabbri et al., 2001; trincardi et al., 2011 a-b). in orange are represented the radiocarbon dating from this work. in grey are represented th/u data from fairbanks (1992) and bard (2003). b: simplified scheme of the transgressive deposit with water depth and age of each unit. the radiocarbon data constrains the time of sedimentation of the transgressive deposit between 11,000 to 9800 cal. a bp, in the time interval following the melt waters pulse 1b (fairbanks, 1989). this was characterized by both the strong influx of freshwater and the increased sediment loads by rivers, especially the po (ariztegui et al., 2000). the dating samples (tab. 1) gave information about the rate of sedimentation in each unit. the unit 1 (thickness up to 1 meter) was deposited in about 500 years, the unit 2 (thickness up to 2 meters) in about 300-500 years, while the unit 3 (thickness up to 1 meters) was deposited in about 200 years. the obtained data were plotted in a depth vs. age plot which groups adriatic 14c age data from fabbri et al. (2001), antonioli et al. (2009) and trincardi et al. (2011 a-b) (fig. 8). the new data coincide with the published curves showing in particular 1110 years gap between the base of the unit 1 and the c surface. considering an average thickness of about 4 meters, the estimated, relative sea-level rise was about 0.4 cm/a. moreover the detailed study of this transgressive deposit showed that the variation of the channel system trend from ene to ese, coincides with the incipient sea-level rise. 6. conclusions the vhr seismic profiles, acquired in the northern adriatic shelf during the nad12 oceanographic cruise, supported key information to characterize in detail the transgressive deposit located offshore ravenna at depth of 34-35 m. the combined study of vhr seismic data and cores gave new information about the sedimentation, evolution and age of the deposit. the transgressive deposit consists of four units, each one of them representing an evolutionary step. the lower units (unit 1, unit 2 and unit 3) correspond to delta plain setting with some distributary channels and a lagoon, while the upper unit (unit 4) represents a barrier-lagoon system with patches of ancient beach at the top. the sedimentation of the transgressive deposit occurred between 11,000 to 9800 cal. a bp. in particular the radiocarbon data allowed to estimate the rate of relative sea-level rise and sedimentation rate of each unit. moreover, the dated layers correspond to peat or organic-rich horizons of brackish lagoon facies, thus, they are representative of the paleo-sea level and mark the aggradation steps of each unit. the variation of the channel system trend from ene to ese occurred during the sea-level rise and it brought to the change of the coastal paleogeography. at the beginning the coast was growing eastward, then the basin flooding (recorded by the unit 3 at 35 m water depth) caused a preliminary drowning of the investigated area and a consequent variation of the channel system trend. the detailed study of this transgressive body shows not only its evolution but also the paleogeography variation of the surrounding areas due to both sea-level rise and the fluvial pattern. acknowledgements this work is part of a phd project in partnership between geoscience department of padova and marine science institute of bologna. we thank the ismar-cnr of bologna that have made available all the cores and vhr seismic profiles acquired during cm94, ar00 and nad12 oceanographic cruises. the research has been partially founded by the italian ministry of education, universities and research miur, within the project ritmare “the italian research for the sea” (belonging to the national research program 2012-2016 and coordinated by the italian national research council-cnr) and through a contract from emilia-romagna region (servizio geologico, sismico e dei suoli). we thank the eth institute for the ams analysis. we thank captain, the crew and all the researches on board r/v urania (cnr) that acquired seismic profiles and cores. this work has been partly supported by the university of padova: cristina stefani and giorgia moscon by institutional found, and by the project: “sea-level variations and subsidence in northern adriatic in the last 130,000 years through geomorphological, stratigraphic and geoarchaeological indicators”, funded by the university of padova (cod. c91j10000320001, supervisot :dr. a. fontana). we thank the two reviewers that allowed to improve the paper. this is cnr ismar -bologna contribution no. 1870 references antonioli f., amorosi a., fontana a., bondesan a., braitenberg c., dutton a., ferranti l., fontolan g., furlani s., lambeck k., mastronuzzi g., monaco c., orrù p. (2009) a review of the holocene sealevel changes and tectonic movements along the italian coastline. quaternary international, 206, 102-133. argnani a., frugoni f. (1997) foreland deformation in the central adriatic and its bearing on the evolution of the northern apennines. annales geophysicae, 40, 771-780. ariztegui d., asioli a., lowe j.j., trincardi f., vigliotti l., tamburini f., chondrogianni c., accorsi c.a., bandini mazzanti m., mercuri a.m., van der kaars s., mckenzie j.a., oldfield f. (2000) palaeoclimate and the formation of sapropel s1: inferences from late quaternary lacustrine and marine sequences in the central mediterranean region. palaeogeography, palaeoclimatology, palaeoecology, 158, 215-240. bard e. (2003) tahiti deglacial relative sea level reconstruction, igbp pages/world data center for paleoclimatology data contribution series 2003-028. noaa/ngcd paleoclimatology program, boulder co, usa. belknap d.f., kraft (1981) preservation potential of transgressive coastal lithosomes on the u.s. atlantic shelf. marine geology, 42, 429-442. cattaneo a., trincardi f. (1999) the late-quaternary transgressive record in the adriatic epicontinental sea: basin widening and facies partitioning. society for sedimentary geology special publication, 64, 127-146. cattaneo a., steel r.j. (2003) transgressive deposits: a review of their variability. earth-science reviews, 62(3), 187-228. 128 moscon g. et al. ciabatti m., curzi p.v., ricci lucchi f. (1987) quaternary sedimentation in the central adriatic sea. giornale di geologia, 49, 113-125. clark p., dyke a., shakun j., carlson, a. clark, j.,wohlfarth b., mitrovica j., hostetler s., mccabe a. (2009) the last glacial maximum. science, 325, 710-714. correggiari a., roveri m., trincardi f. (1996) late pleistocene and holocene evolution of the north adriatic sea. italian journal of quaternary, 9(2), 697-704. correggiari a., trincardi f., langone l., roveri m. (2001) styles of failure in heavily-sedimented highstand prodelta wedges on the adriatic shelf. journal of sedimentary research, 71, 218-236. correggiari a., cattaneo a., trincardi f. (2005) the modern po delta system: lobe switching and asymmetric prodelta growth. marine geology, 222 -223, 49-74. correggiari a., aguzzi m., remia a., preti m. (2011) caratteristiche sedimentologiche e stratigrafiche dei giacimenti sabbiosi in mare adriatico settentrionale utilizzabili per il ripascimento costiero. studi costieri, 19, 11-31. d’argenio b., horvath f. (1984) some remarks on the deformation history of adria, from the mesozoic to the tertiary. annales geophysicae, 2, 143-146. de marchi l. (1922) variazioni di livello dell'adriatico in corrispondenza delle espansioni glaciali. atti della accademia scientifica veneta-trentino-istriana, 12-13, 3-15. fabbri a., argnani a., bortoluzzi g., correggiari a., gamberi f., ligi m., penitenti d., roveri m., trincardi f. (2001) note illustrative della cartografia geologica dei mari italiani scala 1:250.000: foglio nl 33-10 ravenna. fabbri a., argnani a., bortoluzzi g., correggiari a., gamberi f., ligi m., marani m., penitenti d., roveri m., trincardi f. (2002) carta geologica dei mari italiani alla scala 1:250.000. guida al rilevamento. presidenza del consiglio dei ministri, dipartimento per i servizi tecnici nazionali, servizio geologico, quaderni serie iii, 8, 1-93. fairbanks r.g. (1989) 17,000-year glacio-eustatic sea level record: influence of glacial melting rates on the younger dryas event and deep-ocean circulation. nature, 342, 637-642. fairbanks r.g. (1992) barbados sea level and th/u 14c calibration. igbp pages/world data center for paleoclimatology data contribution series 92020. noaa/ngdc paleoclimatology program, boulder co, usa. gasperini l., stanghellini g. (2009) seisprho: an interactive computer program for processing and interpretation of high-resolution seismic reflection profiles. computers & geosciences, 35(7), 14971507. lambeck k., purcell a. (2005) sea-level change in the mediterranean sea since the lgm: model predictions for tectonically stable areas. quaternary science reviews, 24, 1969-1988. maselli v., hutton e.w., kettner a.j., syvitski j.p.m., trincardi f. (2011) high-frequency sea level and sediment supply fluctuations during termination i: an integrated sequence-stratigraphy and modeling approach from the adriatic sea (central mediterranean). marine geology, 287, 54-70. ori g.g., roveri m., vannoni f. (1986) pliopleistocene sedimentation in the apenninicadriatic foredeep (central adriatic sea, italy). allen p.a. & p. homewood (eds), foreland basins. international association of sedimentologists, special publication, 8, 183-198. ridente d., trincardi f. (2005) active foreland deformation evidenced by shallow folds and faults affecting late quaternary shelf-slope deposits (adriatic sea, italy). basin research, 18(2), 171188. stuiver m., reimer p. j. (1993) extended 14c database and revised calib radiocarbon calibration program. radiocarbon, 35(1), 215-230. trincardi f., correggiari a., roveri m. (1994) latequaternary transgressive erosion and deposition in the adriatic epicontinental basin. geo-marine letters, 14(1), 41-51. trincardi f., cattaneo a., asioli a., correggiari a., langone l. (1996) stratigraphy of the latequaternary deposits in the central adriatic basin and the record of short term climatic events. memorie istituto italiano di idrobiologia, 55, 39-70. trincardi f., argnani a., correggiari a. (2011) a note illustrative della carta geologica dei mari italiani alla scala 1:250.000 foglio nl 33-7 venezia.s.el.ca., firenze, it, pp. 151. trincardi f., argnani a., correggiari a. (2011) b note illustrative della carta geologica dei mari italiani alla scala 1:250.000, s.el.ca, fogli ancona nk 33 1/2, bari nk 33-6 e vieste nk 338/9. trincardi f., campiani e., correggiari a., foglini f., maselli v., remia a. (2013) bathymetry of the adriatic sea: the legacy of the last eustatic cycle and the impact of modern sediment dispersal. journal of maps, 10 (1), 151-158. 129 reconstruction of a transgressive deposit ms. received: may 18, 2015 final text received: july 9, 2015 amq abs palombo saccom 177-180.pub available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 177 180 twenty years later: reflections on the aurelian european land mammal age maria rita palombo igag-cnr, c/o dipartimento di scienze della terra, università di roma “sapienza”, roma, italy corresponding author: m.r. palombo <mariarita.palombo@uniroma1.it> abstract: in 1997, some italian palaeontologists proposed a new biochronological assessment for selected italian late pliocenequaternary terrestrial mammal, mollusc and ostracod species. in particular, they proposed a new land mammal age (aurelian lma), emphasising the relevance of the taxonomical and functional turnover that characterised the post-galerian fauna (“extinction of some galerian forms” and the first appearance of “taxa which constitute the core of the modern mammal fauna”). during the following decades, the discovery of several middle pleistocene european local faunal assemblages (lfas) led to a continuous increasing of data and knowledge on the taxonomical status and the chronological range of several large mammal taxa, and new radiometric/absolute dates and magnetostratigraphical information provided substantial evidence, for a new chronological assessment of a number of european lfas. this note aims to present a synthetic overview of the most significant new evidence and some reflections on the transition from the galerian to the aurelian elma, and the significance of the aurelian as european land mammal age. keywords: biochronology, biochronological units, large mammals, middle pleistocene 1. introduction: the fact of the matter the biochronological units (bus) known as land mammal ages (north, nalma, and south american, salma, european, elma, and asian, alma) were initially developed in the first half of the last century in an attempt to chronologically order the north american cenozoic mammalian assemblages (wood et al., 1941). since that time, lmas have been largely, but diversely/ ambiguously used by palaeontologists, and are still loosely defined. the requirements they have to fulfil, indeed, have never been discussed in any stratigraphical code (see lindsay, 2003, pages 213, 220), and the criteria required to create a bu are vague and remain unaddressed. according to tedford (1970, page 602), for instance, a bu (a biological entity equivalent to a discrete natural association of fossil species) could be regarded as non-overlapping and "ecologically adjusted groups of animals with specific geographical limits and chronological range", while lindsay (2003, page 222) defined more explicitly a lma as “a relatively short interval of geologic time that can be recognised and distinguished from earlier and later such units (in a given region or province) by a characterizing assemblage of mammals”. the first/last historical appearance (fha/lha) (palaeobiological events inferred on the basis of the sum of known, palaeobiological data provided by the fossil record derived from strata from the focal geographical region), the peculiar taxonomical composition and ecological structure of the mammalian fauna (which make a bu different from the earlier and later ones recorded in the same geographical area), are the key factors to consider to correctly identify a bu, whichever its chronological range should be. the known lowest and highest stratigraphical occurrence of a taxon in a given geographical area (stratigraphical datum), however, does not necessarily correspond to its first and last appearance in the time (palaeobiological datum). the finding of a taxon, regarded as a biological chrostratigraphical marker of a bu (sensu lindsay, 2003) in stratigraphical levels significantly older/younger than those previously providing its fossil record may, for instance, substantially change the chronological extent of the bu to which it belongs, without changing its theoretical definition. this in turn implies a new assessment and definition of the bus directly preceding/succeeding in time the focal one. in addition, increasing palaeontological and stratigraphical data might allow to better discriminating bioevents, on the one hand highlighting, the gradual transition between successive bus, but, on the other, blurring a clear identification of the bus. as a result, any biochronological scheme, and the definition and temporal extension of a bu, even if dependable, are open to change because depending on the available data,. this note aims to present the main evidence suggesting to revise the definition of the aurelian bu (as provided at the time it was proposed by gliozzi et al., 1997) and its significance as elma, and some preliminary reflections on the issues related to the transition from the galerian to the aurelian elma. a more exhaustive discussion will be provided elsewhere. 2. the aurelian biochronological unit: a reappraisal the aurelian bu was introduced in 1997 in the context of a new biochronological assessment proposed by a team of italian palaeontologists for selected italian late pliocene-quaternary terrestrial mammal, mollusc and ostracod species (gliozzi et al., 1997, page 372). the italian researchers recommended the new aurelian land https://doi.org/10.26382/aiqua.2018.aiquaconference mammal age (lma) for the late middle-late pleistocene mammalian fauna, i.e. from marine isotopic stage (mis) 10 to mis 2, emphasising the relevance of the taxonomical and functional turnover characterising the transition from the galerian to the post-galerian fauna (“extinction of some galerian forms, such as the megacerine cervids of the megaceroides (recte praemegaceros) verticornis group, megaloceros savini and the more archaic elaphine deer”, and the first appearance of “taxa which constitute the core of the modern mammal fauna”) (gliozzi et al., 1997, page 372). the characterisation of the new lam was mainly based on the taxonomical composition of some italian local faunal assemblages (lfas) found in “deposits, which date to the late middle pleistocene and the late pleistocene” (gliozzi et al., 1997, page 372). the fha of canis lupus, ursus spelaeus and magaloceros giganteus (mentioned as regards to their fha in the oldest aurelian faunal unit) were the bioevents chosen by gliozzi et al. (1997) to identify the beginning of the aurelian bu, but what about the time of the fha of these taxa in europe? new evidence dates back the c. lupus presence to mis 14(?) – mis 13 (galería gii, atapuerca, spain) (rodriguez et al., 2011; álvarez-posada et al., 2018). a small wolf, canis lupus lunellensis, was already reported from lunel viel (france), a site dating to about 400350 ka (brugal and boudadi-maligne, 2011 and references therein), and the modern wolf is also recorded, together with m. giganteus, during mis 11 in some european lfas, for instance, in britain (stewart, 2008 and references therein). the time of the lowest stratigraphical occurrence in europe of u. spelaeus cannot firmly be established due to some confusing taxonomical treatments of some specimens (most lacking sound taxonomical diagnostic features), likely belonging to one or the other species of the cave bear lineage known in the middle pleistocene: ursus deningeri and its putative descendant u. spelaeus. in schreve’s opinion (schreve, 2001, page 1694), for instance, in the “swanscombe mammal assemblage-zone” (mis 11) “the early middle pleistocene form ursus deningeri reichenau” was “superseded by the more advanced form ursus spelaeus”. the deninger’ bear, conversely, has been reported even from significantly younger lfas, such as orgnac 3 levels 7-3 (france) (e.g. sam, 2009). the available data, moreover, indicate that some among the large mammals commonly found in the aurelian lfas were already present either in the postjaramillo early pleistocene (e.g. palaeoloxodon antiquus, crocuta crocuta, lynx pardinus, sus scrofa), or in the early middle pleistocene (mis 19 mis 12) (e.g. ursus arctos, ursus thibetanus, vulpes vulpes, cuon alpinus, felis silvestris, stephanorhinus hemitoechus, bos primigenius, dama clactoniana, bison priscus, bos primigenius, maybe rupicapra pyrenaica), or at least during mis 11(e.g. hippopotamus ex gr. h. amphibius, modern roe deer capreolus capreolus, m. giganteus), suggesting to predate the beginning of the aurelian bu (fig.1, 2). assuming that the hypothesis could be correct, the question arises about the time of the transition from the galerian to the aurelian bu. according to gliozzi et al. (1997, page 372), the late galerian fauna, to which only the fontana ranuccio f.u. was referred, “is characterised by the total disappearance of typical villafranchian taxa with the exception of homotherium” and by the presence of “the red fig. 1 chronological range of selected middle and late pleistocene european proboscideans, primates, and carnivora. 178 palombo m.r. deer subspecies cervus elaphus eostephanoceros. as regards to the “villafranchian” large predators, new data indicate that the saber-toothed cat was still present during mis 3 (reumer et al., 2003), and panthera gombaszoegensis in deposits correlated to mis 9 or mis 10 (marciszak, 2014). it is worth noting, that fontana ranuccio lfa (anagni basin, central italy), regarded by gliozzi et al. (1997) as one of the most representative late galerian site and epitome of the homonymous f.u., was at that time dated to 0.458 ma (mis 12). the age of most of the european lfas successively correlated to the fontana ranuccio lfa or ascribed to the homonymous f.u. fall in the chronological range of mis 13 and mis 12. recently, pereira et al. (2018) obtained a 40ar/39ar age of 408±10 ka for the archaeological level (unit fr4) of fontana ranuccio, roughly corresponding to mis 11 climatic optimum, in some agreement with the fauna ecological structure. according to the new date, the lfa would fall in the extended chronological range of the aurelian bu, together with other roughly coeval lfas from the same geographic area already regarded as “aurelian” (e.g. isoletta, lademagne). although this fact could not substantially affect the definition of the “late galerian”, the question about the significance of c. e. eostephanoceros as a biological chrostratigraphical marker remains unsolved. in the gaudo san nicola lfa, a site chronologically and geographically close to fontana ranuccio, indeed, sala et al. (2014) claimed the presence of the archaic cervus eluphus acoronatus subspecies, considering c. e. eostephanoceros a young synonymous of the former. all in all, the available data evidence the gradual, progressive transition from a elma to the successive one during the late early and middle pleistocene, as well as the complexity in properly detecting and defining such elmas. 3. remarks the sum of evidence highlights the gradual modification of the structure of the mammalian palaeocommunities, leading to the configuration of the aurelian ones (e.g. palombo, 2017), and, in turn, the difficulty to properly define discrete lmas succeeding each other during a short geological time. the original lma concept, indeed, implicitly implies a long persistence in time and a wide geographical extent for each unit, given that the mean duration of a large mammal cenozoic species is about 3 ma (see prothero, 2014 as regards to the north american mammals). therefore, the shorter the time slice is, the more difficult to properly define a lma could be. any analysis performed on short geological time periods, for instance, may sometimes force researchers to consider taxa at a low taxonomical rank, thereby increasing the risk of disagreements in the taxonomies applied by the authors. additional drawbacks may concern the need of a particularly detailed chronology, in contrast with a proportionally low number of lfas with firm chronological constrains. an alternative approach may be to focus more on the detection of "ecologically adjusted groups of animals with specific geographical limits and chronological range" than merely on fha/lha bioevents. following this line of reasoning, taking into account: i) the climatic and environmental changes (e.g. the increase in summer temperatures, and average forest expansion during interglacial phases) that occurred since mis 11; ii) its peculiarity with respect to the previous middle pleistocene interglacials (higher level than present-day sea related to the collapse of greenland and west antarctica ice sheets, greenhouse gas-driven climate warming pattern of insolation variability matching the holocene one) (e.g. oliveira et al., 2016 and references therein), iii) the number of fha reported at that time (figs. 1, 2), 179 reflections on the aurelian elma fig. 2 chronological range of selected middle and late pleistocene european perissodactyla and cetartiodactyla. iv) the functional diversity characterising the large mammal fauna since mis 11 (palombo, 2016), the hypothesis to chronologically extend the aurelian bu to include mis 11 seems to be the most reasonable. as a result, the definition and biochronological significance of the “late galerian” fauna, which according to gliozzi et al. (1997) only includes the “fontana ranuccio faunal unit”, has to be reconsidered. references álvarez-posada c., parés j.m., cuenca-bescós g., van der made j., rosell j., bermúdez de castro j.m.b., carbonell e. (2018) a post-jaramillo age for the artefact-bearing layer td4 (gran dolina, atapuerca): new paleomagnetic evidence. quaternary geochronology, 45, 1-8. brugal j.p., boudadi-maligne m. (2011) quaternary small to large canids in europe: taxonomic status and biochronological contribution. quaternary international, 243(1),171-182. garcía-medrano p., cáceres i., ollé a., carbonell, e. (2017) the occupational pattern of the galería site (atapuerca, spain): a technological perspective. quaternary international, 433, pp. 363-378. gliozzi e., abbazi l., ambrosetti p., argenti, p., azzaroli a., caloi l., capasso barbato l., di stefano g., esu d., ficcarelli g., girotti o., kotsakis t., masini f., mazza p., mezzabotta c., palombo m.r., petronio c., rook l., sala b., sardella r., zanalda e., torre d. (1997) biochronology of selected mammals, molluscs, ostracods from the middle pliocene to the late pleistocene in italy. the state of the art. rivista italiana di paleontologia e stratigrafia, 103 (3), 369-388. lindsay e.h. (2003) chapter 10: chronostratigraphy, biochronology, datum events, land mammal ages, stage of evolution, and appearance event ordination. bulletin of the american museum of natural history, 212-230. marciszak a. (2014) presence of panthera gombaszoegensis (kretzoi, 1938) in the late middle pleistocene of biśnik cave, poland, with an overview of eurasian jaguar size variability. quaternary international, 326, 105-113. oliveira d., desprat s., rodrigues t., naughton f., hodell d., trigo r., rufino m., lopes c., abrantes f., goni, m.f.s. (2016) the complexity of millennial-scale variability in southwestern europe during mis 11. quaternary research, 86(3), 373-387. palombo m.r. (2017) discrete dispersal bioevents of large mammals in southern europe in the postolduvai early pleistocene: a critical overview. quaternary international, 431, 3-19. palombo m.r. (2016) to what extent could functional diversity be a useful tool in inferring ecosystem responses to past climate changes? quaternary international, 413, 15-31. pereira a., nomade s., moncel m.h., voinchet p., bahain j.j., biddittu i., falguères c., giaccio b., manzi g., parenti f., scardia g. (2018) integrated geochronology of acheulian sites from the southern latium (central italy): insights on humanenvironment interaction and the technological innovations during the mis 11-mis 10 period. quaternary science reviews, 187, 112-129. prothero d.r. (2014) species longevity in north american fossil mammals. integrative zoology, 9 (4), 383-393. reumer j.w., rook l., van der borg k., post k., mol d., de vos j. (2003) late pleistocene survival of the saber-toothed cat homotherium in northwestern europe. journal of vertebrate paleontology, 23(1), 260-262. sala b. boulbesn., moigne a-m., thun hohenstein u. (2014) in: muttillo b., lembo g. peretto, c. (eds), l'insediamento a bifacciali di guado san nicola, monteroduni, molise, italia. annali univ ferrara, museologia scient. nat., 10(1a), 1-160. sam y. (2009) etude paléontologique, archéozoologique et taphonomique des grands mammifères du site pléistocène moyen d’orgnac 3 (ardèche, france) phd dissertation, university of perpignan, france. schreve d. (2001) differentiation of the british late middle pleistocene interglacials: the evidence from mammalian biostratigraphy. quaternary science reviews, 20(16-17), 1693-1705. stewart j.r. (2008) the progressive effect of the individualistic response of species to quaternary climate change: an analysis of british mammalian faunas. quaternary science reviews, 27(27-28), 2499-2508. tedford r.h. (1970) principles and practices of mammalian geochronology in north america. in proceedings of the north american paleontological convention, 1 (part f), 666-703. wood 2nd h.e., chaney r.w., clark j., colbert e.h., jepsen g.l., reeside jr j.b., stock c. and committee (1941) nomenclature and correlation of the north american continental tertiary. bulletin of the geological society of america, 52(1), 1-48. 180 palombo m.r. ms. received: may 2, 2018 final text received: may 14, 2018 amq84 zoboli et al proofcopy 3 available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 31 (1), 2018, 75 86 does a relationship exist between palaeopathologies and insularity ? a case study of some bones of prolagus sardus (wagner, 1829) from sardinia (italy) daniel zoboli 1, marco zedda 2, gian luigi pillola 1, maria rita palombo 3 1dipartimento di scienze chimiche e geologiche, università di cagliari, cagliari, italy 2dipartimento di medicina veterinaria, università di sassari, sassari, italy 3cnr, igag, c/o dipartimento di scienze della terra, sapienza università di roma, roma, italy corresponding author: d. zoboli <zoboli.a@tiscali.it> abstract: this research describes pathological bones of prolagus sardus (lagomorpha, ochotonidae) from four middle-late pleistocene to early holocene sites of sardinia (italy), and presents a short inventory of the main sardinian localities recording the species, with the intent to infer the viability of the sardinian ochotonid populations during the middle-late pleistocene and early holocene. the macroscopical analysis evidences that the pathologies were mostly of a traumatic origin, rather than due to other pathological conditions, which have been only observed in a few individuals inhabiting the tavolara islet. the significance of the occurrence of palaeopathological signatures in bones of insular, mammals and their usefulness in detecting the life-style, behaviour and niche occupancy of endemic mammalian species, and reconstructing some aspects of population dynamics in the peculiar island environments, are briefly discussed. keywords: palaeopathology, palaeoecology, lagomorpha, quaternary supplementary appendices only online at http://amq.aiqua.it 1. introduction fossil endemic lagomorpha, including ochotonidae, are known only on the western mediterranean islands, where endemic genera have been reported since the miocene epoch from the balearic islands (genus gymnesicolagus from majorca and minorca) (bover et al., 2014; mas et al., 2018), and the tusco-sardinian palaeobioprovince (genus paludotona from baccinello basin, tuscany) (dawson, 1959; angelone et al., 2017). moreover, some insular species of the genus prolagus are recorded in the ?early pliocene in the gargano palaeoarchipelago (mazza, 1987), and in the pliocene holocene of the corsica-sardinia massif (angelone et al., 2015). representatives of the sardinian endemic lineage are a quite common element in the sardinian late pliocene holocene fossil record, and fossil remains are especially abundant in the middle to late pleistocene sardinian local faunal assamblages (lfas) (dragonara faunal sub-complex of the microtus (tyrrhenicola) fc) (cf. palombo, 2009, 2018). the oldest remains, currently referred to prolagus aff. p. figaro (angelone et al., 2015), were collected in the late pliocene deposits of mandriola (capo mannu, sinis peninsula) (pecorini et al., 1974; lópez martínez & thaler, 1975; angelone et al., 2015). p. aff. p. figaro of mandriola probably originated from the mainland species prolagus sorbinii, a taxon of eastern european origin, which migrated westwards during the early messinian (masini, 1989; angelone et al., 2015). the ancestor of the corso-sardinian prolagus lineage (p. figaro p. sardus) (angelone et al., 2015) probably passively dispersed to the island at the early/late pliocene transition, possibly taking advantage from a reduction of the mainland to island distance during a phase of sea-level lowering. its direct descendant prolagus figaro (early pleistocene late early pleistocene) is reported at capo figari i and in several fissure fillings of monte tuttavista (lópez martínez, 1975; abbazzi et al., 2004; palombo, 2009; palombo & rozzi, 2014; moncunill-solé et al., 2016). p. figaro likely survived until the end of the orosei 2 faunal sub-complex (palombo & rozzi, 2014; palombo, 2018). the last and most advanced representative of the corso-sardinian prolagus lineage, prolagus sardus, was the most common species in the quaternary mammal fauna of sardinia and corsica (zoboli & caddeo, 2016). the species, erected by wagner in 1829 on the basis of remains collected in the bone breccias of monreale di bonaria (cagliari) (wagner, 1829), was the first pleistocene endemic mammal identified in sardinia. the fossil remains of the large ochotonid, typically found in a number of lfas of the dragonara faunal sub-complex (palombo, 2009, 2018; moncunill-solé et al., 2016), are particularly abundant in caves and karst fissure fillings, but also quite frequent in the early holocene to iron age deposits, either recording or not a human presence (comaschi caria, 1968; vigne et al., 1981; wilkens, 2000; zoboli & pillola, 2017). the transition from p. figaro to p. sardus, which probably occurred during the https://doi.org/10.26382/amq.2018.12 76 early middle pleistocene (palombo & rozzi, 2014), is marked by an increase of about 20% in bm (but not in dental dimensions) (average bm p. figaro = 398-436 gr; p. sardus = 504-525 gr) (moncunill-solé et al., 2016). p. sardus was very successful in colonising different environments of the corsica-sardinia massif, as it can be inferred from the abundance of remains, the very wide distribution within the region and the chronology of fossiliferous deposits the species has been recorded from (see appendix a). in the course of the holocene, however, population richness and abundance possibly declined. p. sardus probably disappeared in the roman period, after the spread on the island of rattus rattus (vigne et al., 1981). the persistence of the ochotonid in roman period seems to be confirmed by polibio (206-124 b.c.), who mentioned a "small hare" in the corsican fauna (wilkens, 2000). the hypothesis of a survival of prolagus on the tavolara islet (ne sardinia) until the late 18th is currently abandoned (wilkens, 2000). it is still a matter of debate which among several factors could have been the main responsible for the ochotonid decline and extirpation. some human’s influence is, however, indubitable, whatever it could be direct (e.g. hunting) or indirect (e.g. active and passive introductions of alien species, including new predators and competitors, spread of pathogens, parasites, and in turn infectious diseases, and modification of the landscape by agricultural activities), or due to both factors (vigne, 1996; vigne et al., 1981, macphee & preston, 1997; palombo & rozzi, 2014; ucchesu et al., 2015; melis et al., 2017). the aim of this research is two fold, i) to describe pathological bones of p. sardus found in sardinia in four middle pleistocene early holocene caves, including one anthropogenic deposit (fig. 1); ii) to discuss the origin of such pathologies with the view to provide some information on the p. sardus population health. congenital and/or non-traumatic pathologies may, indeed, increase in very small populations or in populations subjected to environmental stress. stressful conditions may also increase inbreeding depression (the reduced biological fitness in a given population as a result of inbreeding) (e.g. atmar, 1993; frankham, 1998; alcover et al., 1999; roldan & gomendio, 2009; fox & reed, 2011). we also present a synthetic inventory (appendix a) of the main sardinian localities recording the species, with the intent to appraise the extent of the fossil record and infer the viability of the endemic ochotonid populations from the middle pleistocene to the early holocene. 2. material and methods 2.1. material most of the material analysed herein was collected during archaeological excavations performed in 2008 by a university of cagliari team at su carroppu (carbonia, sw sardinia), a site where the human presence seems to be documented since about 10 ka bp (modi et al., 2017). some other bones were recovered from the middle pleistocene sequence of grotta dei fiori (older than 500 ka) (carbonia sw sardinia) (melis et al., 2013), and from a small fissure filling at "surconis", a locality near the village of bolotana (central sardinia). the chronology of this deposit is uncertain, either late pleistocene or early holocene (zoboli & pillola, 2016). the analysis also includes few remains belonging to the major’s collection (naturhistorisches museum of basel, switzerland, nmb) found on the tavolara islet (ne sardinia) (zoboli, 2017). a comparison was made with materials belonging to the collections stored in the museo sardo di geologia e paleontologia d. lovisato (university of cagliari, italy, mdlca), and using literature data (appendix b). 2.2. methods pathology each remain departing in some way from the normality has been carefully analysed. first of all, particular attention has been paid to distinguish lesions involving the whole bone, probably related to a systemic disease, from lesions affecting only limited areas of the bone surface. among the later, a distinction between pathological signs present either on the bone or on the joint surface was made. the disease that fig. 1 location map of the studied localities. zoboli d. et al. 77 23774, pl. 1, fig. 3) respectively found in the grotta dei fiori and su carroppu samples. both fractures were fully healed as documented by the union of fragments through the formation of a well-evident bone callus. the fracture of the rib was complete, transverse and nondisplaced. the great dimension of its callus is due to the breathing continuous movements. the fracture of the ulna was complete, oblique and displaced. as a result, the bone fragments remained separated even during the healing, forming a well visible groove. the lesion did not affect the radius that, therefore, represented a stable support permitting the ulna healing. some pathological lesions of traumatic origin have been detected in the distal epiphysis of a tibia (mdlca 23776, pl. 1, fig.11), a calcaneum (mdlca 2377, pl. 1, fig. 12), some metapodials (mdlca 23779/1-5, pl. 1, figs. 14-18), and phalanges (mdlca 23781, mdlca 23782, pl. 1, figs. 20-21) collected at su carroppu. the bones show an extensive growth of bone tissue around and on the articular surfaces, likely caused by a chronic inflammation of the join surface. some evidence of osteoarthritis are detectable at level of the crurotarsal joint, between the distal epiphysis of tibia and the proximal articular surfaces of tarsal bones, i.e. astragalus and calcaneum. the extent of the overproduction of bone tissue shown by the right tibia (mdlca 23776, pl. 1, fig. 11) may suggest that the osteoarthritis originated from a dislocation of the crurotarsal joint, probably due to a traumatic event, such as either a fall, a violent impact, or an excessive muscular effort. analogous inflammation processes caused a pathological overproduction of bone tissue also in interphalangeal joints of phalanges and at level of metapodial bones (mdcla 23779/1-5, pl. 1, figs. 14-18). the osteoarthritis process was so pronounced to lead to ankylosis processes that caused the fusion of articulated bones and, thereby, the immobility of the distal interphalangeal joint (mdlca 23782, pl. 1, fig. 21). some cervical (mdlca 23783/ 1-4, pl. 1, figs. 2225) and lumbar vertebrae (mdlca 23784/1-3, pl. 1, figs. 26-28) from su carroppu show pathological lesions likely caused by spondyloarthropathy. in the pathological humerus from su carroppu (mdlca 23773, pl. 1, fig. 2) and femur from surconis (mdlca 23772, pl. 1, fig. 9), the pathologies were likely caused by metabolic diseases. the diaphysis of both long bones, which belong to juvenile individuals (the distal epiphyses are not fused) are abnormally arched. this anomalous growth is attributable to a bone softening caused by an impaired bone metabolism, known as osteomalacia. the inadequate bone mineralization is generally caused by a deficiency of levels of calcium, phosphate and vitamin d. the pathological condition, named also “rickets”, is more frequently reported among young individuals and is primary related to a malnutrition or insufficient sun light exposition. this pathological condition is also visible in a metapodial bone from su carroppu (mdlca 23780, pl. 1, fig. 19). the fact that all the three arched long bones belong to juvenile individuals confirms the diagnosis. a zeugopodium (radius and ulna) (mdlca 23775, pl. 1, fig. 4) from surconis shows interesting pathological lesions. a large mass of bone tissue surrounds the caused each pathological lesions was inferred by means of the diagnosis and classification of bone palaeopathologhies provided in the specialized literature (baker, 1978; baker & brothwell, 1980; bendrey, 2014; driesch, 1989). living bone tissue is known to have a limited repertoire of responses to any prolonged/unusual stress, therefore, it often reacts in similar ways to different pathogenic factors (bartosiewicz, 2008). accordingly, we consulted texts on veterinary pathology and clinics to formulate a more compelling diagnosis and better inferring the factors causing the pathological lesions (slatter, 2003; tobias & johnston, 2012). body mass (bm) estimate it is well-known that body size (bs), and in turn the bm that generally has been regarded as its best proxy (gingerich et al., 1982), are strictly related to animal life history, metabolic and reproductive rates, architecture and physiology, ecology and ethology (see among several others blueweiss et al. 1978; mcnab, 1990; auer et al., 2018; naya et al., 2018). accordingly, bs/bm represents a pivotal aspect of mammal adaptive strategy, also limiting, for instance, the number of species to be found in a given area, intra and interspecific relationships, exploitation of resources, and, indirectly, the population health. since the femur is the bone most frequently recording pathological signatures in the samples herein analysed, the bm estimate is herein based only on the femur dimensions, by means of the equations proposed for lagomorphs by moncunill-solé et al. (2015, 2016) (logbody mass, bm=−1.11+2.229 log femur lenght, fl; and logbm=0.318+2.481log distal femoral transversal diameter, ftdd), and quintana et al. (2011) (logbm=2.487 logftdd +0.141). measurements were taken by means of a digital electronic precision calliper (0.05 mm error) on femora of fully adult individuals (fused epiphyses). a comparison was made with the bm of p. sardus specimens for which measurements of femur are available in literature: monte tuttavista (moncunill-solé et al., 2016), grotta dei fiori, cava alabastro, medusa-dragonara cave, s’omu s’orcu (boldrini & palombo, 2010; boldrini et al., 2010), tavolara islet and tramariglio breccias (van der geer et al., 2013). 3. results 3.1. pathology the percentage of pathological bones is definitely low if compared to the number of healthy bones present in the analysed samples. in the surconis and su carroppu samples (the only two samples for which the total number of limb bones collected during excavation is known), the percentage of bones showing pathological signatures is lower than 2%, and only ten lesions have been noticed in on the vertebrate and ribs of the analysed samples. among the pathological lesions detected in the samples, most could be referred to trauma, though a few likely depend on metabolic diseases and tumour. a list of the main pathological lesions is shown in appendix c. fractures are present, for instance, on a rib (mdlca 23786, pl. 1, fig. 30) and an ulna (mdlca palaeopathologies in bones of prolagus sardus 78 zoboli d. et al. middle part of the diaphysis. the irregular surface characterising this anomalous bone tissue accretion suggests a rapid and irregular growth, typical of a malignant bone tumour such as osteosarcoma. a collateral effect of this serious pathology is the bone fragility leading to spontaneous fractures, as it occurred to the zeugopodium from surconis, where the lack of the distal part of both radius and ulna was likely caused by a fractures that separated them from the diaphysis. the proximal epiphysis of a left femur (nmb ty. 7308, pl. 1, fig. 5) from tavolara islet shows serious pathological bone erosion and bone remodelling. in the caput femoris, the part lacking bone tissue formation is surrounded by overabundant osteophytes, a phenomenon typical present in case of osteonecrosis pathology. the aetiology comprises a fracture at level of the femoral neck or a hip joint dislocation. this type of trauma, indeed, can provoke the interruption of blood supply in the femoral head, and, in turn the death of cells resulting in an avascular necrosis. it is interesting to note that a high level of steroids may represent a risk factor in the pathogenesis of this kind of lesion (drescher et al., 2011). as regards to the ochotonid population confined on tavolara islet, it could be speculate that this pathology was somehow related to the presence in the mediterranean flora of species containing phytosteroids (cf. among others desole, 1960; bocchieri et al, 2011; riccobono, 2016), that some prolagus in tavolara islet were forced or inclined to eat, increasing the steroid levels in their organism. 3.2. body mass estimate the average bm estimates for the p. sardus samples here studied, whose age ranges from older than to 500 ka (grotta dei fiori) to the late early holocene (greenlandian stage, mesolithic period) (su carroppu) (see appendix a), highlights an extremely large range of variation in the selected samples. the variation is irrespective of the age and the size of the samples, as it appears, by comparing the range of the quite large sample of monte tuttavista xir fissure (52 specimens) with the small tramariglio breccias sample (4 specimens), or the range of samples with no so different number of specimens (e.g. monte tuttavista vib6 fissure, 18 specimens, and tavolara, 11 specimens) (fig. 2). the average bm estimated for the mesolithic site of su carroppu (about 412 gr) and the possibly older surconis site (about 490 gr) would suggest that the size of p. sardus, slightly decrease during the early holocene. this hypothesis, however, has to be considered with a great caution because the uncertainty about the actual age of surconis, the small number of specimens available for the analysis, and the extremely large range of the body mass variation shown by the analysed samples (fig. 3). the morphological and dimensional analysis of the prolagus samples from monte tuttavista, has already suggested that this species underwent an anagenetic evolution that involved both the morphology of dental elements, leading to an asymptotic increase in size of dental and postcranial elements (angelone et al., 2008). the average bm of the samples analysed herein, conversely, fails to comply with the progressive increase in 79 <<<<< plate 1 pathological bones of prolagus sardus from different localities of sardinia. 1) left humerus, radius and ulna (nmb ty. 8797, major’s collection) in lateral view, showing a process of ankylosis of the elbow joint probably due to a serious arthrosis, and of the radioulnar joints probably due to an extensive process of periostitis. tavolara islet, holocene. 2) left humerus of a juvenile individual (mdlca 23773) in postero-medial view, showing a curvature of the diaphysis caused by a bone osteomalacia. su carroppu, mesolithic. 3) right ulna and radius (mdlca 23774) in lateral view. a complete and displaced fracture involving the radius and the successive extensive bone remodelling process led to the fusion of the diaphysis of the two bones. the arrow indicates the groove corresponding to the space between the two bone fragments. su carroppu, mesolithic. 4) right ulna and radius (mdlca 23775) in anterolateral view. the middle part of the diaphyses of both bones show a great mass of bone tissue possibly related to an osteosarcoma leading to contemporary phenomena of exuberant proliferation of bone tissue and bone resorption that induces bone fragility and predisposes to spontaneous fractures. surconis, late pleistocene-early holocene. 5) left femur (nmb ty. 7308, major’s collection) in anterior (a) and posterior (b) view. in the femoral head, the large areas of missing bone tissue are surrounded by exuberant osteophytes, which coud be caused by osteonecrosis or chronic osteoarthritis. tavolara islet, holocene. 6) right femur (mdlca 23769) in anterior (a), medial (b) and posterior (c) view. the proximal epiphysis shows pathological signs consisting of bone erosion and bone remodelling, probably due to the osteoarthritis or osteonecrosis of the femoral head. su carroppu, mesolithic. 7) right femur (mdlca 23770) in anterior (a), lateral (b) and posterior (c) view. the arrows indicate osteophytes due to a periostitis. su carroppu, mesolithic. 8) right femur (mdlca 23771) in anterior (a), lateral (b) and posterior (c) view. the arrow indicates a presence of exuberant bone tissue probably related to a periostitis. su carroppu, mesolithic. 9) right femur (mdlca 23772) of a juvenile individual in anterior (a), lateral (b) and posterior (c) view. the diaphysis shows a curvature likely caused by the one softening that often occurs during the osteomalacia. surconis, late pleistocene-early holocene. 10) right tibiofibula (nmb ty. 7177, major’s collection) in anterior (a) and posterior (b) view. the sample shows a complete, angulated and displaced fracture of the diaphysis healed by an extensive bone remodelling process. tavolara islet, holocene. 11) right tibiofibula (mdlca 23776) in anterior view. the arrow indicates a periarticular osteophyte that can be associated with a wide chronic inflammation of the crurotarsal joint. su carroppu, mesolithic. 12-13) comparison between a patological (12) (mdcla 23777) and a healthy (13) (mdlca 23778) right calcaneus in anterior view. the arrow indicates an exuberant bone tissue probably due to the chronic inflammation of the nearby soft tissues. su carroppu, mesolithic. 14-18) metapodials (mdlca 23779/1-5). the arrows indicate osteophytes nearby the joints. su carroppu, mesolithic. 19) metapodial bone (mdlca 23780). the diaphysis shows a curvature caused by a bone softening that occurs during an osteomalacia process. su carroppu, mesolithic. 20) first phalanx (mdlca 23781) in plantar view. the arrow indicates a periarticular osteophyte. su carroppu, mesolithic. 21) second and third pahanges (mdlca 23782) in lateral view, showing an ankylosis process affecting the distal interphalangeal joint. su carroppu, mesolithic. 22-24) cervical vertebrae (mdlca 23783/1-3). the arrows indicate osteophytes related to chronic inflammation of the intervetebral joints (spondylartrosis). su carroppu, mesolithic. 25) sixth and seventh cervical vertebrae (mdlca 23783/4) in dorsal view, showing an intervertebral ankylosis. su carroppu, mesolithic. 26-28) lumbar vertebrae (mdlca 23784/1-3) in dorsal view. the arrows indicate osteophytes due to the chronic inflammation of the intervertebral joints. su carroppu, mesolithic. 29) healthy lumbar vertebrae (mdlca 23785) in dorsal view (for comparison), su carroppu, mesolithic. 30-32) ribs showing a complete not displaced and healed fracture (30) (mdlca 23786, grotta dei fiori, middle pleistocene) and some osteophytes (31, 32) (mdlca 23787/1-2, su carroppu, mesolithic). the arrows indicate the pathologies. scale bar = 1 cm. palaeopathologies in bones of prolagus sardus p. sardus bm during time. the results obtained show that the lower average bm value corresponds to the oldest prolagus sample from grotta dei fiori (but followed by that of su corroppu and s’omu s’orcu, the youngest among the analysed sites), while the highest average value corresponds to the sample from cava alabastro, a locality for which a middle pleistocene age cannot be excluded (minieri et al., 1995; boldrini & palombo, 2010). the pattern of the minimum and maximum values of the bm estimated for each samples also fails to confirm any matching betweent the long bone size and their chronology. in addition, the results of this work, and the new radiometrical data of medusa-dragonara cave (palombo et al., 2017), question the hypothesis that of a positive relationship may exist in prolagus between increase in temperature and femur length (boldrini & palombo, 2010). boldrini & palombo (2010) made a preliminary analysis on a few prolagus femurs to ascertain whether temperature would affect the femur length in the sardinian ochotonid, following the allen’s rule (allen, 1877) (animals living in cold geographical regions show limbs consistently shorter than those of related species living in warmer climatic conditions) or because temperature control the cartilage growth as it has been demonstrated for rodents (serrat et al., 2008). it is worth noting, however, that boldrini & palombo (2010) based they suggestion of a possible positive correlation between femur dimensions and the temperature (inferred according to the δ18o values obtained from teeth and bones of p. sardus) on the chronological assessment of the sardinian sites as accepted at that time, but successively modified according to new studies and radiometric data (palombo & rozzi, 2014; palombo et al., 2017). the results obtained herein by using as variable ftdd are poorly convincing as evidenced by the bm estimations obtained for surconis and su carroppu samples, which sensibly differ depending on the applied regression equations (fig. 4). the variable ftdd estimates a bm above the arithmetic mean of that obtained using fl following (moncunill-solé et al., 2016), (surconis = 511.87-797.44, m 638.38 gr; su carroppu = 361.88-629.50, m 484.50 gr), while they are inferior following quintana et al. (2011) (surconis = 424.62538.2, m 426.53 gr; su carroppu = 243.77424.62, m 326.17 gr). the correlation between value obtained considering fl and ftdd is low, especially as regards to surconis, suggesting an intra-population variation of length vs distal articular transversal diameter of the femur that clearly exceeds the minimal variation potentially related to sexual dimorphism, known to be minimal in the extant ochotona (smith, 1988; nowak, 1999). all in all, the results obtained indicate that the bm can be hardly regarded as a useful indicator for providing specific information on the health condition of a p. sardus population. 4. discussion the study of palaeopathology is an interesting research field that may provide valuable clues for inferring the life-style of animals in the past, their behaviour and niche occupancy, the predator-prey relationships, and some aspects of population/ecosystem dynamics (moodie, 1923; baker & brothwell, 1980; rothschild & tanke, 1992; rothschild & martin, 1993; rothschild et al., 2001; beatty & rothschild, 2009; tanke & rothschild, 2010; grauer, 2012; salesa et al., 2014). palaeopathological studies, moreover, may be the starting point to evaluate the state of health of an animal population and to frame this in a palaeoecological perspective. the chance of surviving of a pathological individual depends on a number of factors, among which the quality of resources, food availability and the extent 80 fig. 2 comparison among the variation ranges of body mass in sardinian p. sardus samples ranging in age from the middle pleistocene to the early holocene (see appendix a). fig. 3 box plots comparing the variation range of the body mass (estimated by using as variable the femur maximum lenght, fl, and the wide of the femur distal epiphysis, ftdd) in the p. sardus samples from surconis (blue) and su carroppu (red). zoboli d. et al. whether resources availability, and ecological interaction and displacement are among the major factors driving evolution and survival in isolated environments (lomolino et al., 2013). moreover, the active or passive introduction by humans of mainland species may expose native taxa to exotic pathogens to which the insular species had no opportunity to develop a reasonable resistance (macphee & preston, 1997). pathological modifications of the bone tissues can even be caused by congenital diseases/disorder genetically inherited. the genetic defects may be related to the increase of individuals homozygous and therefore the increase of the appearances of recessive traits in small populations and marked inbreeding. this may be not the case of the sardinian ochotonid due its incredibly rich fossil records, both in abundance of remains, number and geographical distribution of fossiliferous sites, and longevity of the species. the notable abundance of prolagus remains accounts for a persistent high population density during time (see appendix a). this, joined with the differences in morphology and the increased bm of p. sardus with respect to its ancestors may indicate that the species characteristics correspond to those of vertebrate isolated populations showing the so-called "island syndrome" (or "insular syndrome") (thiollay, 1993). accordingly, it may be speculated that, in line with the syndrome, the sardinian ochotonid may have had a behaviour different from those characterising the mainland populations, and a higher reproductive output, and demography, as shown in small mammals (mappes et al., 2008), but still questioned in large mammals (köhler and moyà-solà, 2009). the relative low number of pathological bones present in the analysed samples and, perhaps, the large range of the dimensional variation may suggest that pathologies due to traumatic events were more frequent in p. sardus bones than those related to disease. this hypothesis cannot be adequately supported by data on of predation and competition pressure are the most influential. accordingly, analysing palaeopathologies and their origin may be a useful tool for reconstructing the ecological balance of a region, particularly as regards to poorly diversified, disharmonic and unbalanced vertebrate faunas, like those characterising isolated ecosystems, such as islands. a variety of factors, in addition to traumatic injuries, may induce the presence of skeletal pathologies in wild animals (endogamy, disease, congenital degenerative lesions, malnutrition due to either low forage quantity or high population density, low predator pressure etc.). the inbreeding depression, the reduced biological fitness in a given population as a result of breeding of related individuals in small, isolated populations, has been sometimes hypothesised as a concurrent phenomenon in the modifications shown by endemic species. insular populations are expected to suffer increased inbreeding with respect to their ancestor populations living on mainland, because of the lower number of colonisers and the subsequent small population sizes, and the bottleneck effect likely occurring at their establishment on the island. as regards to human populations, for instance, it has been argued that the combined action of founder effect, genetic drift, and inbreeding may increase the frequency of detrimental rare variants, leading to an overall worsening of population health (rudan et al., 2006). in the case of wild mammals, the survival of animals with injuries or diseases limiting their mobility and function suggests the possibility of “a support system” which allowed their survival (rothschild & tanke, 1992). this may be particularly true as the survival in insular environments, due to the reduced predator and competitor pressure. conversely, the augment of interguild and intraspecific competition for resources, which may be related to overpopulation, likely hampers the survival of animals affected by some kind of physical illness. therefore, studies of palaeopathology in insular endemic mammals may help in answering questions 81 fig. 4 scatter diagrams comparing, in the p. sardus samples from surconis and su carroppu, the relationship between the maximum lenght (fl) of femur and the values of body mass obtained by using as variable the wide of the femur distal epiphysis (ftdd) according to the regression equations proposed by moncunill-solé et al. (2016) (a) and quintana et al. (2011) (b). palaeopathologies in bones of prolagus sardus the frequency of pathological bones in fossil and extant lagomorphs. although, indeed, some osteopathologies due to traumatic injuries (e.g. jordana et al.; 2011; palombo & zedda, 2016; lyras et al. 2016), osteoarthritis (peterson e al., 2010), and metabolic diseases (dermitzakis et al., 2006) are reported in island large mammals, such kind of patologies are poorly known as regards to wild mainland and insularl lagomorphs. most of studies and researches deal with with dental and cranial anomalies (e.g. among others suchentrunk, et al., 1992; jekl & redrobe, 2013; böhmer & böhmer, 2017), or with domestic animals, rarely with wild rabbits and hears (e.g. among others eriksson et al., 1984; desanto, 1997; batiste et al., 2004; okuda et al., 2007; delaney et al., 2018). it is worth noting, however, that accidental fractures of limb bones, as for instance those observed in the p. sardus samples analysed herein (pl. 1, figs 3, 10, 30), could be someway related to either the structural characteristic of the skeleton or to a peculiar locomotory aptitude. in extant ochotonidae, for instance, some ecological specialisation based on different locomotory adaptation are known (smith, 1988, 1990, 2008; reese et al., 2013). two skeletal ecotypes have been recognised corresponding to different behaviour and life-style: i) meadow-dwellers, specialised in burrowing and characterised by a short, highly fecund and highly social life; ii) rock-dwellers, specialised in leaping and characterised by a long, asocial and lower fecund life. the meadowdweller ochotonid first use forelimbs to scratch and dig more or less deep cavities, then both fore limbs and hind limbs are involved to move backwards out of the burrow. the rock-dwellers ochotonid usually jump among rocks covering horizontal and vertical distances from a few centimetres to a more than three times their body length. the burrowing species show a well-developed, strong olecranon process (hildebrand, 1985), while rock -dwelling species generally have proportionally longer limb bones and feet that are helpful in frequent leaping from rock to rock (reese et al., 2013). the morphology of p. sardus pelvis and limb bones suggest that the species had a powerful limb muscles, hind-limbs likely adapted to jump, but also a limb maneuverability wider than those shown by most of extant leporids (dawson, 1969). more detailed studies and comparison among skeletal morphological features of prolagus samples coming from sites having different physiographical location (e.g. rocky mountains, flat grasslands, and coastal dunary sites) are, however, necessary to verify whether in sardinia only one, both or additional ecotypes were present. results of our ongoing researches dealing whith these questions will be present elsewhere. whatever the behaviour of ochotonid sardinian populations was and the fact that only one or both ecotypes were present on the island, back and hind-limb bones of prolagus were likely prone to fracture, due to their structure similar to the lagomorph skeleton. in rabbits, for instance, the skeleton represents only 7% to 8% of the body weight (opposed to the 12% to 13% in cats), and fractures of the back and hind-limbs are not so infrequent because of the hindlimb musculature and the delicate nature of the skeleton (graham & mader, 2012). this could explain the origin of the traumatic lesions observed in specimens found in different localities. a some higher frequency of pathological lesions in the hind-limb than fore-limb bones could be seen as a hint of the jumping aptitude of prolagus and a confirmation of the pivotal role that the hind limbs had in the hypothesis has to be confirmed by further investigations, its locomotion, as it typically occurs in jumping animals. some lesions among those described in bones from all the sites analysed are, however, related to diseases, although apparently they are not congenital. the deformation shown by the zeugopodium (radius and ulna) (pl. 1, fig. 4) from surconis, for instance, was caused by an osteosarcoma, leading to the spontaneous fractures of both radius and ulna. however, considering its quite large size, the osteosarcoma onset cannot be related to a poor health condition of the population the pathological individual belongs to. some environmental constrains could be, conversely, conjectured as regards to the pathological bone erosion and an bone remodelling shown by the p. sardus femur from the tavolara islet (pl. 1, fig. 5). the hypothesis that the pathology may be related to a high level of steroids accumulated by this individual because of a peculiar feeding behaviour focused on mediterranean plant species containing a high quantity of phytosteroids, cannot, indeed, ruled out. it is, however, difficult to hypothesise about factors that may have led to this peculiar feeding propensity. all things considered, and taking into account the low percentage of pathological bones in the analysed samples, the fact that the lesions of traumatic origin (fractures and periostites) were definitely more frequent than those related to malnutrition or tumours, and that all the observed lesions were compatible with life, it seems reasonable to hypothesise that the sardinian p. sardus populations did not suffered any kind of marked environmental stress. during the middle-late pleistocene, the maintenance of a healthy population status was possibly permitted on the one hand by the predator pressure (raptors and the small canid cynotherium, the most common terrestrial predator, specialised to hunt and eat the sardinian ochotonid), which contributes to limit the increasing in size of prolagus population (e.g. lópez martínez, 2001; robert & vigne, 2002; lyras & van der geer, 2006; novelli & palombo, 2007; novelli et al., 2008; lyras et al., 2016), on the other hand by the lack of effective competitors. the coeval non-predatory mammals (the megacerine praemegaceros cazioti, the vole microtus (tyrrhenicola) henseli, the murid rhagamys orthodon, the insectivores “nesiotites” similis and talpa tyrrhenica), hade indeed, a different feeding behaviour and ecological requirements. lagomorphs, to which prolagus belonged, are moreover used to ingest up to 80% of their feces (cecotropes animals), which are rich in vital nutritious elements, such as vitamins, produced by the intestinal bacteria flora. this behaviour probably allowed prolagus to balance their nutritional requirement and in turn to survive also in the event of starvation periods. 82 zoboli d. et al. 5. conclusions the results obtained by this study (performed in the attempt to scrutinise the health status of p. sardus sardinian populations), although preliminary, suggest that during the middle-late pleistocene to the early holocene the specie did not suffer any serious environmental stress. the percentage of pathological bones found in the analysed samples is low and the observed pathologies on the one hand were mainly caused by traumatic/accidental factors, on the other hand no evidence of pathologies related to congenital disease have been detected. accordingly, it is reasonable to suppose that the size of p. sardus populations maintained itself enough large to prevent any kind of inbreeding and related pathological risks. the conformity of prolagus physical characteristics to those regarded as typical of rodent populations showing the so-called “island/ insular syndrome” would imply a high reproductive rate. the extraordinary rich fossil record of the sardinian ochotonid, whose remains are definitely more abundant than those of all the other endemic pleistocene mammalian species (including rodents) as the number of remains and sites where the remains were present may support this hypothesis. the pathologies shown by the analysed bones provide some indirect hints as regard to the role (if any) that the changes underwent by the prolagus body structure as a result of insular isolation may have had in facilitating the breakage of limb bones especially during jumping. p. sardus, indeed, had a musculoskeletal systems, especially as regard the posterior limbs, much more massive than those of extant pikas, as underlined by the pioneering study of dawson (1969). the powerful muscles, therefore, possibly caused to bones tension/ torsion stress higher than that compatible with the bone tissue elasticity. the present research also evidences the wide range of intra-population variation of p. sardus dimensions, as well as the fluctuation in the average bm throughout time, which is apparently unrelated either to the chronology or to climate. all in all, results obtained on th one hand highlight that p. sardus despite the amount of its remains, is still a poorly known species, on the other hand may represent a start point for further investigations. acknowledgments the authors thank a. van der geer and b. moncunill-solé for their helpful comments on the earlier version of the paper, and the curators of the museums we visited for their helping during the analysis of the collections stored in their institutions. this research was supported by “contributo ateneo per la ricerca” of cagliari university (leader glp). dz acknowledges the sardinia regional government for financial support to phd scholarship (p.o.r. sardegna f.s. e. operational programme of the autonomous region of sardinia, european social fund 2007-2013 axis iv human resources, objective l.3, line of activity l.3.1). references abbazzi l., angelone c., arca m., barione g., bedetti c., delfino m., kotsakis t., marcolini f., palombo m.r., pavia m., piras p., rook l., torre d., tuveri c., valli a.m.f., wilkens b. (2004) pliopleistocene fossil vertebrates of monte tuttavista (orosei, e. sardinia, italy), an overview. rivista italiana di paleontologia e stratigrafia, 110(3), 603628. alcover j.a., seguı́ b., bover p. (1999) extinctions and local disappearances of vertebrates in the western mediterranean islands. in: macphee r.d.e. (ed.), extinctions in near time, kluwer academic/ plenum publishers, new york, usa, 165-188. allen j.a. (1877) the influence of physical conditions in the genesis of species. radical review, 1, 108140. angelone a., čermák s., rook l. (2017) new insights on paludotona, an insular endemic lagomorph (mammalia) from the tusco-sardinian palaeobioprovince (italy, turolian, late miocene). rivista italiana di paleontologia e stratigrafia, 123(3), 455473. angelone a., stanislav c., kotsakis t. (2015) the most ancient lagomorphs of sardinia: an overview. geobios, 48(4), 287-296. angelone c., tuveri c., arca m., lópez martínez n., kotsakis t. (2008) evolution of prolagus sardus (ochotonidae, lagomorpha) in the quaternary of sardinia island (italy). quaternary international, 182, 109-115. atmar w., patterson b.d. (1993) the measure of order and disorder in the distribution of species in fragmented habitat. oecologia, 96(3), 373-382. auer s.k., dick c.a., metcalfe n.b., reznick d.n. (2018) metabolic rate evolves rapidly and in parallel with the pace of life history. nature communications, 9(1), 14. baker j.r. (1978) the differential diagnosis of bone disease. in: brothwell d.r., thomas k.d., clutton-brock j. (eds.), research problems in zooarchaeology. institute of archaeology, london, uk. baker j.r., brothwell d. (1980) animal diseases in archaeology. academic press, london, uk. bartosiewicz l. (2008) description, diagnosis and the use of published data in animal palaleopathology: a case study using fractures. veterinarija ir zootechnika, 41(63), 12-24. batiste d.l., kirkley a., laverty s., thain l.m., spouge a.r., holdsworth d.w. (2004) ex vivo characterization of articular cartilage and bone lesions in a rabbit acl transection model of osteoarthritis using mri and micro-ct. osteoarthritis and cartilage, 12(12), 986-99 beatty b.l, rothschild b.m. (2009) paleopathologies are features of an organism and its interaction with the environment and should not be treated like organisms unto themselves: commentary. historical biology, 21(3-4), 229-233. bendrey r. (2014) animal palaeopathology. in: smith c. (ed.), the archaeological record. springer, 258 83 palaeopathologies in bones of prolagus sardus 84 265. blueweiss l., fox h., kudzma v., nakashima d., peters r., sams s. (1978) relationships between body size and some life history parameters. oecologia, 37(2), 257-272. bocchieri e., iiriti g. (2011) biodiversità vegetale in sistemi microinsulari della sicilia e della sardegna. biogeographia the journal of integrative biogeography, 30(1), 177-196. böhmer c., böhmer e. (2017). shape variation in the craniomandibular system and prevalence of dental problems in domestic rabbits: a case study in evolutionary veterinary science. veterinary sciences, 4(1), 5. boldrini r., palombo m.r. (2010) did temperature regulates limb length in the sardinian endemic ochotonid prolagus sardus. atti convegno in memoria di alberto malatesta (1915-2007), geologo e paleontologo, 12-13. boldrini r., palombo m.r., iacumin p., melis r.t. (2010) the middle pleistocene fossiliferous sequence of grotta dei fiori (sardinia, italy): multidisciplinary analysis. bollettino della società paleontologica italiana, 49(2), 123-134. bover p., rofes j., bailón s., agustí j., cuenca‐bescos g., torres e., alcover j.a. (2014) late miocene/ early pliocene vertebrate fauna from mallorca (balearic islands, western mediterranean): an update. integrative zoology, 9(2), 183-96. comaschi caria i. (1968) fossili marini e continentali del quaternario della sardegna. in: maxia c. (ed.), atti del x congresso internazionale di studi sardi (simposio sul quaternario sardo), cagliari, italy, 139-230. dawson m.r. (1959) paludotona etruria, a new ochotonid from the pontian of tuscany. naturforschungs gesellschaft basel, 70(2), 157-166. dawson m.r. (1969) osteology of prolagus sardus, a quaternary ochotond (mammalia, lagomorpha). palaeovertebrata, 2, 157-190. delaney m.a., treuting p.m., rothenburger j.l. (2018) lagomorpha. in: terio k., mcaloose d., leger st. j. (eds), pathology of wildlife and zoo animals, academic press, 481-498. dermitzakis m.d., van der geer a.a.e., lyras g.a. (2006) paleopathological observations on a population of fossil deer from the late pleistocene of crete. in: kalofourtis a., papadopoulos n., spiliopoulos c., maravelias k., chatziioannou a. (eds), volume in honour of professor andonis koutselinis, athens, 43-51. de santo j. (1997) hypertrophic osteopathy associated with an intrathoracic neoplasm in a rabbit. journal of the american veterinary medical association, 210(9), 1322-1323. desole l. (1960) flora e vegetazione dell'isola tavolara. webbia, 15 (2): 461-587. drescher w., schlieper g., floege j., eitner f. (2011) steroid-related osteonecrosis-an update. nephrology dialysis transplantation, 26(9), 2728-2731. driesch von den a. (1989) la paléopathologie animale. analyse d‘ossements animaux pathologiques pré-et protohistoriques. revue de médicine veterinaire, 140(8-9), 645-652. eriksson r.a., albrektsson t., magnusson b. (1984) assessment of bone viability after heat trauma: a histological, histochemical and vital microscopic study in the rabbit. scandinavian journal of plastic and reconstructive surgery, 18(3), 261-268 fox c.w., reed d.h. (2011) inbreeding depression increases with environmental stress: an experimental study and meta‐analysis. evolution. international journal of organic evolution, 65(1), 246258. frankham r. (1998) inbreeding and extinction: island populations. conservation biology, 12(3), 665-675. gingerich p.d., smith b.h., rosenberg k. (1982) allometric scaling in the dentition of primates and prediction of body weight from tooth. american journal of physical anthropology, 58, 81-100. graham j., mader d. (2012) basic approach to veterinary care. in: quesenberry k.e., carpenter j.w. (eds.), ferrets, rabbits and rodent. clinical medicine and surgery, ed. 3. saunders, philadelphia, 174-182. grauer a.l. (2012) a companion to paleopathology. wiley blackwell hoboken, new jersey. hildebrand m. (1985) digging of quadrupeds. in: hildebrand m., bramble d.m., liem k.f., wake d.b. (eds.), functional vertebrate morphology. belknap press, cambridge, 89-109. jekl v., redrobe s. (2013) rabbit dental disease and calcium metabolism the science behind divided opinions. journal of small animal practice, 54(9), 481-490. jordana x., galtés i., isidro a., malgosa a., köhler m. (2011) estudio macroscópico, radiológico y histológico de una fractura tibial de myotragus balearicus. in: gonzález martín a., cambra-moo o., rascón pérez j., campo martín m., robledo acinas m., labajo gonzález e., sánchez sánchez j.a. (eds.), paleopatología: ciencia multidisciplinar, universidad autónoma de madrid, madrid, spain, 435-439. köhler m., moyà-sola s. (2009) physiological and life history strategies of a fossil large mammal in a resource-limited environment. proceedings of the national academy of sciences, 106(48), 2035420358. lomolino m.v., geer a.a., lyras g.a., palombo m.r., sax d.f., rozzi r. (2013) of mice and mammoths: generality and antiquity of the island rule. journal of biogeography, 40(8), 1427-1439. lópez martínez n. (2001) paleobiogeographical history of prolagus, an european ochotonid (lagomorpha). lynx, 32, 215-231. lópez martínez n., thaler l. (1975) biogéographie, évolution et compléments à la systématique du groupe d’ochotonidés piezodus prolagus (mammalia, lagomorpha). bulletin de la société géologique de france, 17, 850-866. lyras g.a., giannakopoulou a., lillis t., veis a., papadopoulos g.c. (2016) bone lesions in a late pleistocene assemblage of the insular deer candiacervus sp. ii from liko cave (crete, greece). international journal of paleopathology, zoboli d. et al. 14, 36-45. lyras g.a., van der geer a.a.e. (2006) adaptations of the pleistocene island canid cynotherium sardous (sardinia, italy) for hunting small prey. cranium, 23(1), 51-60. macphee r.d.e., preston a.m. (1997) lightning strikes twice: blitzkrieg, hyperdisease, and global explanations of the late quaternary catastrophic extinctions. american museum of natural history new york, spring symposium, usa. mcnab b.k. (1990) body size in mammalian paleobiology. cambridge university press, cambridge, 1123. mappes, t., grapputo, a., hakkarainen, h., huhta, e., koskela, e., saunanen, r., suorsa, p. (2018) island selection on mammalian life-histories: genetic differentiation in offspring size. bmc evolutionary biology, 8, 296. mas, g., maillard, a., alcover, j.a., fornós, j.j., bover, p., torres-roig, e. (2018) terrestrial colonization of the balearic islands: new evidence for the mediterranean sea-level drawdown during the messinian salinity crisis. geology, 46, 527-530. masini, f. (1989). prolagus sorbinii n. sp., a new ochotonid (mammalia, lagomorpha) from the messinian of italy. bolletino della società paleontologica italiana, 28, 295-306. mazza p. (1987) prolagus apricenicus and prolagus imperialis: two new ochotonids (lagomorpha, mammalia) of the gargano (southern italy). bollettino della società paleontologica italiana, 26(3), 233-243. melis r.t., depalmas a., di rita f., montis f., vacchi m. (2017) mid to late holocene environmental changes along the coast of western sardinia (mediterranean sea). global and planetary change, 155, 29-41. melis r.t., ghabel b., boldrini r., palombo m.r. (2013) the grotta dei fiori (sardinia, italy) stratigraphical successions: a key for inferring palaeoenvironment evolution and updating the biochronology of the pleistocene mammalian fauna from sardinia. quaternary international, 288, 81-96. minieri m.r., palombo m.r., scarano m. (1995) microtus (tyrrhenicola) henseli (major, 1882) del pleistocene superiore di cava alabastro (is oreris; iglesias; sardegna sudoccidentale). geologica romana, 31, 51-60. modi a., tassi f., susca r.r., vai s., rizzi e., de bellis g., lugliè c., gonzalez fortes g., lari m., barbujani b., caramelli d., ghirotto s. (2017) complete mitochondrial sequences from mesolithic sardinia. scientific reports, 7. doi: 10.1038/srep42869. moncunill‐solé b., quintana j., jordana x., engelbrektsson p., köhler m. (2015) the weight of fossil leporids and ochotonids: body mass estimation models for the order lagomorpha. journal of zoology, 295(4), 269-278. moncunill-solé b., tuveri c., arca m., angelone c. (2016) comparing the body mass variations in endemic insular species of the genus prolagus (ochotonidae, lagomorpha) in the pleistocene of sardinia (italy). rivista italiana di paleontologia e stratigrafia, 122(1), 25-36. moodie r.l. (1923) palaeopathology: an introduction to the study of ancient evidences of disease. university of illinois press: urbana, il, usa. naya d.e., naya h., white c.r. (2018). on the interplay among ambient temperature, basal metabolic rate, and body mass. the american naturalist, 192(4), 518-524. novelli m., palombo m.r. (2007) hunter schreger bands in cynotherium sardous studiati, 1857 from dragonara cave (late pleistocene, north-western sardinia). grzybowski foundation special publication, 12, 61-71. novelli m., palombo m.r., arca m., tuveri c. (2008) hunter-scheger bands in cynotherium sardous studiati 1957 di monte tuttavista (orosei, sardegna centro-orientale). geologica romana, 41, 6570. nowak r.m. (1999) walker’s mammals of the world volume ii. johns hopkins university press: baltimore. okuda a., hori y., ichihara n., asari m., wiggs r.b. (2007) comparative observation of skeletaldental abnormalities in wild, domestic, and laboratory rabbits. journal of veterinary dentistry, 24(4), 224-229. palombo m.r. (2009) biochronology, paleobiogeography and faunal turnover in western mediterranean cenozoic mammals. integrative zoology, 4, 367386. palombo m.r. (2018) insular mammalian fauna dynamics and paleogeography: a lesson from the western mediterranean islands. integrative zoology, 13(1), 2-20. palombo m.r., antonioli f., presti v.l., mannino m.a., melis r.t., orru p., stocchi p., talamo s., quarta g., calcagnile l., deiana g. (2017) the late pleistocene to holocene palaeogeographic evolution of the porto conte area: clues for a better understanding of human colonization of sardinia and faunal dynamics during the last 30 ka. quaternary international, 439, 117-140. palombo m.r., rozzi r. (2014) how correct is any chronological ordering of the quaternary sardinian mammalian assemblages? quaternary international, 328, 136-155. palombo m.r., zedda m. (2016) surviving in a predator-free environment: hints from a bone remodelling process in a dwarf pleistocene deer from crete. comptes rendus palevol, 15, 245-254. pecorini g., rage j.c., thaler l. (1974) la formation continentale de capo mannu, sa faune de vertébrés pliocènes et la question du messinien en sardaigne. rendiconti semestrali delle facoltà scientifiche dell’università di cagliari, 43, 305-319. peterson r.o., vucetich j.a., fenton g., drummer t.d., larsen c.s. (2010) ecology of arthritis. ecology letters, 13(9), 1124-1128. quintana j., köhler m., moyà-solà s. (2011) nuralagus rex, gen. et sp. nov., an endemic insular giant rabbit from the neogene of minorca (balearic islands, spain). journal of vertebrate paleontolol 85 palaeopathologies in bones of prolagus sardus ms. received: august 17, 2018 final text received: november 27, 2018 86 ogy, 31(2), 231-240. reese a.t., lanier h.c., sargis e.j. (2013) skeletal indicators of ecological specialization in pika (mammalia, ochotonidae). journal of morphology, 274, 585-602. riccobono l. (2016) metabolites from mediterranean plants: characterization and transformation. chemotaxonomic assessment and biological activity. phd dissertation, palermo university, palermo. robert i., vigne j.d. (2002) bearded vulture gypaetus barbatus contributions to the constitution of two different bone assemblages: modern reference data and an archaeological example in corsica. acta zoologica cracoviensia, 45, 319-329. roldan e.r., gomendio m. (2009) sperm and conservation. sperm biology, 539-564. rothschild b.m., martin l.d. (1993) paleopathology: disease in the fossil record. crc pressi llc. rothschild b.m., tanke d.h. (1992) paleoscene 13. paleopathology of vertebrates: insights to lifestyle and health in the geological record. geoscience canada, 19(2), 73-82. rothschild b.m., tanke d.h., ford t.l. (2001) theropod stress fracturesand tendon avulsions as a clue to activity. in: tanke d.h., carpenter k. (eds.), mesozoic vertebrate life. indiana university press. rudan i., biloglav z., vorko-jović a., kujundžić-tiljak m., stevanović r., ropac d., puntarić d., čučević b., salzer b., campbell h. (2006) effects of inbreeding, endogamy, genetic admixture, and outbreeding on human health: a “1001 dalmatians” study. croatian medical journal, 47(4), 601-610. salesa m.j., antón m., siliceo g., pesquero m.d., alcalá l. (2014) first evidence of pathology in the forelimb of the late miocene saber-toothedfelid promegantereon ogygia (machairodontinae smilodontini). anatomical record, 297, 1090-1095. serrat m.a., king d., lovejoy c.o. (2008) temperature regulates limb length in homeotherms by directly modulating cartilage growth. proceedings of natural academy of sciences, 105(49), 1934819353. slatter d. (2003) textbook of small animal surgery. saunders-elsevier, i-ii. smith a.t. (1988) patterns of pika (genus ochotona) life history variation. in: boyce m.s. (ed.), evolution of life histories: theory and patterns from mammals. yale university press, new haven, ct, 233-256. smith a.t. (2008) the world of pikas. in: alves p.c., ferrand n., hackländer k. (eds.), lagomorph biology: evolution, ecology, and conservation. springer-verlag, berlin. smith a.t., weston m.l. (1990) ochotona princeps. mammalian species, 352, 1-8. suchentrunk f., markowski j., janiszewski t., hartl g.b. (1992) studies on the european hare. 45. dental and cranial anomalies in austrian and polish brown hare lepus europaeus populations. acta theriologica, 37(3), 241-257. tanke d.h., rothschild b.m. (2010) paleopathologies in albertan ceratopsids and their behavioral significance. new perspectives on horneddinosaurs. indiana university press: bloomington and indianapolis, indiana, usa. thiollay j. (1993) habitat segregation and the insular syndrome in two congeneric raptors in new caledonia, the white‐bellied goshawk accipiter haplochrous and the brown goshawk a. fasciatus. ibis, 135(3), 237-246. tobias k.m., johnston s.a. (2012) veterinary surgery: small animals. elsevier-saunders, i-ii. ucchesu m., peña-chocarro l., sabato d., tanda g. (2015) bronze age subsistence in sardinia, italy: cultivated plants and wild resources. vegetation history and archaeobotany, 24(2), 343-355. van der geer a.a.e., lyras g.a., lomolino m.v., palombo m.r., sax d.v. (2013) body size evolution of palaeo-insular mammals: temporal variations and interspecific interactions. journal of biogeography, 40(8), 1440-1450. vigne j.d. (1996) zooarchaeology and the biogeographical history of the mammals of corsica and sardinia since the last ice age. mammal review, 22, 87-96. vigne j.d., marinval-vigne m.c., de lanfranchi f., weiss m.c. (1981) consommation du lapin-rat (prolagus sardus wagner) au néolithique ancien méditerranéen abri d'araguina-sennola (bonifacio, corse). bulletin de la société préhistorique française, 78(7), 222-224. wagner r. (1829) über den zahnbau der gattung lagomys. isis von oken, 22, 1132-1141. wilkens b. (2000) osservazioni sulla presenza in epoca recente del prolago sardo a tavolara secondo le notizie di francesco cetti. atti 3° convegno nazionale di archeozoologia (siracusa, 2000), 217 -222. zoboli d. (2017) i vertebrati quaternari sardi conservati nel naturhistorisches museum di basilea (svizzera). museologia scientifica nuova serie, 11, 70-76. zoboli d., caddeo g.a. (2016) articulated skeletons of prolagus sardus (mammalia, lagomorpha) from the quaternary of grotta del campanaccio (santadi, southwestern sardinia). bollettino della società paleontologica italiana, 55(1), 81-83. zoboli d., pillola g.l. (2016) quaternary mammal fauna from “surconis”, bolotana (sardinia, italy). bollettino della società paleontologica italiana, 55(3), 193-203. zoboli d., pillola g.l. (2017) upper pleistocene mammal assemblage from su concali quarry (samatzai, southern sardinia, italy). rivista italiana di paleontologia e stratigrafia, 123(2), 243254. zoboli d. et al. microsoft word 05_sulli_lm05.doc available online http:/amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 25 (2), 2012, 141-156 variability of depositional setting along the north-western sicily continental shelf (italy) during late quaternary: effects of sea level changes and tectonic evolution attilio sulli1, mauro agate1, maria mancuso2, fabrizio pepe1, valentina pennino1, sabrina polizzi1, valeria lo presti1, francesco gargano1, francesco interbartolo1 1 dipartimento di scienze della terra e del mare università di palermo, italy 2 istituto per l’ambiente marino costiero, cnr, napoli, italy corresponding author: a. sulli <attilio.sulli@unipa.it> abstract: the geological, geomorphological and sedimentological features of the north-western sicily continental shelf are here illustrated with the aim to propose a geological model able to explain the neogene-quaternary evolution of the sicilian continental margin in the context of the central mediterranean region. above the continental shelf and upper slope the sedimentary succession, showing along the different sectors of the margin considerably variable internal geometry and stratigraphic relationships with the underlying units, is interpreted as a iv order depositional sequence (late quaternary depositional sequence, lqds) deposited during the last eustatic change (last 125 ky). the lower boundary of the lqds is represented by a subaerial erosional surface formed during the last eustatic sea level fall ended in the lgm (20-18 ka). this unconformity lies above a seaward dipping pleistocene succession whose depositional architecture is in turn controlled by quaternary eustatic sea-level fluctuations. a dense dataset of morphobathymetric and high resolution seismic data allowed to recognize along the continental shelf to bathyal plain system different types of continental shelf with different stratigraphic and morphostructural settings, associated to both large-scale processes and specific factors related to more local control: a) predominantly rocky shelves, both accompanied by a moderate frontal sedimentary prism and with a structural edge, in the structural highs of the monti di palermo offshore and around the main rocky headlands (capo san vito, monte catalfano); b) depositional shelves, in the castellammare, palermo and termini imerese gulfs, both with a regular seaward deepening of the substrate and with a substrate uplift at the shelf break. we confirm that depositional sequences in this margin are the result of the interaction between sea level changes and sedimentation, but demonstrate that the tectonic activity has played a key role, not only in the creation of different types of continental shelves, but also to determine the different characters of each sequence in different areas. the general tectonic uplift during the pleistocene, together with the episodic alternation of extensional and compressional events, often with strike-slip component, is responsible for the thickness and facies variation both onland, where residual pleistocene marine deposits today outcrops, and in the continental shelf, where most of the depositional sequences developed and are now recognized. as well tectonic activity exerted a control on the geomorphological features (e.g. pockmarks and mounds) of the present day coastal areas and shelf-slope system, as well as for the submarine canyons and the mass failure processes. keywords: continental shelf, sequence stratigraphy, northern sicily continental margin, morphobathymetry, neotectonics. 1. introduction the continental shelf is a shallow marine area, less than 200 m deep on average with low inclination (less than 1-2°), surrounding almost all the continental plates. it extends from the external edge of the inshore (submerged beach) until the sudden and significant increase in the inclination of the seabed, which indicates the beginning of the continental slope, characterized by much higher values, up to 10°. in this area of "transition" subaerial and submarine processes interact to determine the geological and environmental evolution. it can also record considerably the effects of anthropogenic pollution linked to navigation, mining and other productive activities along the coast. the knowledge on continental shelves have increased in recent decades thanks to the investigations on mineral resources or hydrocarbons or features of seabed and substrate on which to lay cables, pipelines and platforms. even the research aimed to fishing and conservation of marine protected areas have acquired a wealth of morphologic, stratigraphic, sedimentological and structural data. the characteristic feature of the continental shelf is to be periodically flooded by the sea alternatively with periods of subaerial exposure, so landscape, environment and physical-chemical conditions change here dramatically and frequently, at least at the scale of geological time. according to the most recent reconstructions (imbrie et al., 1984; martinson et al., 1987; williams et al., 1988) exposition and flooding phases have occurred all over the world with periodicity of 150-200 ky during the last million years. the continental shelf is thus a highly dynamic environment where studies on the effects of subaerial and submarine processes are essential for a correct reconstruction of the most recent geological evolution. in addition to eustatic and global climatic processsulli a. et al. 142 es, regional factors, as tectonic processes and nature of sedimentary supply, affect the geological evolution of the continental shelf. sedimentation along the shelves is dominated by sand deposition together with organogenic carbonates and marine fossils-bearing pelites, in different percentages depending on the climatic zones, the prevailing type of coastline (high or low) and the presence or absence of large river mouths, as well as the distance from coast and the water depth. the activity of benthic organisms and of various types of traction currents (waves, tides, coastal currents, etc.) characterizes the sediments that accumulate in shallow marine environments. even the presence of special biocenosis (marine phanerogams grasslands, platform coralligenous, etc.), if sufficiently wide, may be relevant. northern sicily continental shelf is a part of the continental margin that links the sicily chain to the tyrrhenian back-arc basin (fig. 1), so it’s a key area to understand the processes that occurred in this part of the central mediterranean, built up mainly during the neogene-quaternary. the scientific interest, connected with the high and variable seismicity of the area, the neotectonic activity, the high and variable uplift/subsidence rate, the occurrence of depositional sequence generated by the interaction between relative sea level changes and sediment supply, and the economic interest, due to the occurrence of bioand geo-resources, are at the base of the large availability of geological data. this work describes the geomorphological, stratigraphic and sedimentological features in selected areas of the north-western sicily continental shelf, summarizing the common features associated with large-scale processes and highlighting the specific factors related to more local control, with the aim to propose a geological model able to explain the evolution of this physiographic units in the context of the central mediterranean region. 2. geological background the northern sicily continental margin (fig. 1) is located in the southern tyrrhenian sea, from the north sicily coastal belt to the marsili abyssal plain, in the transitional area between the sicilian-maghrebian chain to the south and the tyrrhenian basin to the north (nicolich, 1985; scarascia et al., 1994). this continental margin is composed of: (1) a narrow (<8 km) and steep (up to 2.5°) continental shelf, with the edge between -95 m and -140 m. around 40 m water depth the external sector of the shelf, mainly characterized by hemipelagic sedimentation, is separated by an internal sector with higher hydrodynamics where mainly terrigenous and locally biogenic sedimentation prevails; (2) a very steep (7-8°) upper continental slope ranging in depth from 150 to 1000 m; (3) a flat intra-slope basin plain at a depth of 1500 m; (4) a lower continental slope that is wider and gentler than the upper slope, and (5) a bathyal plain from a depth of 3000 m. the wave regime (gulf of palermo and termini) is characterized by nw, ne and e directions (astraldi et al, 2002). the storm waves reach usually 3-4 m in height, have a period of 6 s and an annual frequency of 3% (istituto idrografico della marina, 1982). the tidal excursion indicate a microtidal regime with a tide height varying between 0.37 and 0.60 m a.s.l. the water salini fig. 1 physiography of the northern sicily continental margin, with location of earthquake epicentres in northern sicily mainland and offshore. isobath interval: 0-200 m each 50 m; from 500 upward each 500 m. in the bottom left corner: simplified tectonic map of the central mediterranean region. variability of depositional setting along the north-western sicily continental shelf (italy) ... 143 ty has no considerable variation between summer and winter, remaining between 37.6‰ and 38.2‰ (demirov & pinardi, 2002). along the shelf and the upper slope, the quaternary deposits consist of seawards dipping clastic and terrigenous deposits coming from the northern sicily (pepe et al., 2003; agate et al., 2005), whereas in the basinal areas hemipelagic sediments are locally intercalated with volcanoclastic sediments (baghi et al., 1980). in the continental shelf, the pleistocene deposits are truncated by an erosional surface formed during the last glacio-eustatic oscillation. local uplift caused the systematic non-preservation of portions of the oldest sequences (pepe et al., 2003). prograding sedimentary wedges of coastal deposits formed during the last glacial maximum (lgm, about 18 ka) are present along the shelf margin. the prograding wedges are absent where the heads of the canyons or failure scars have indented the outer shelf (lo iacono et al., 2011). integrated high resolution study based both on seismic reflection data and on micropaleontological-sedimentological analisys of a core collected in the outer shelf of the gulf of termini, allowed the recognition of two drastic sea-level falls during the last glacial maximum and the younger dryas, and provided the different position of sea level during the last 41 ky. the northern sicily continental margin originated as a consequence of a complex interaction of compressional events, crustal thinning and strike-slip faulting. following the early-middle miocene deformation and thrusting of the kabilian-calabrian units and the most internal units of the sicilian-maghrebian chain (catalano et al., 1985; pepe et al., 2005), the opening of the tyrrhenian sea led to the subsidence of the northern sicilian margin since the late tortonian (baghi et al., 1980; fabbri et al., 1981). late miocene-early pliocene northdipping high-angle reverse faults, involving mainly deep seated, carbonate platform units, produced structural highs (avellone et al., 2010), among which those seaward bounding the intraslope basins (pepe et al., 2003), termed peri-tyrrhenian basins by selli (1970), filled with late neogene to quaternary evaporitic, hemipelagic, siliciclastic and volcaniclastic deposits, up to 1200 m thick (baghi et al., 1980). later, normal faults partly dissected the backand fore-limb of the structural high. middle-upper pliocene reflectors clearly diverge towards the normal fault bordering the basin, thereby demonstrating syn-extensional deposition (pepe et al., 2003). e-wto ne-sw-trending normal faults exerted during the pleistocene a control on the morphology of the present day shelf and coastal areas. as a consequence two types of basins formed in the north sicily continental margin (pepe et al., 2005): (1) minor intra-slope basins (e.g. palermo and termini basins) whose origin is related to the (?) late miocene early pliocene shortening and thrusting of the sicilianmaghrebian chain, and (2) major extensional basins (e.g. cefalù basin) whose origin is connected to the continental rifting which affected the internal side of the margin during the middle (?) -late pliocene, as demonstrated by synextensional deposition. the tectonic activity of the northern sicily continental margin is outlined by a large upper plate seismicity (fig. 1), producing a seismogenic region characterized by compressional focal mechanisms to the west, while in the eastern sector extensional and strike-slip mechanisms prevail. shallow (<25 km) seismic events of low to moderate magnitude (max md 5.6 on september 2002) occur along an e-w trending belt located northward. the focal mechanisms related to the main seismic shocks are in agreement with a dominant nesw fault trend coupled with a nw-se compressive offset direction (agate et al., 2000; giunta et al., 2009). the highest uplift rates during the last 125 ky in northern sicily (ferranti et al., 2010) were found on the inner margin-terraces in the eastern coast (0.8-1.63 mm/y), whilst the holocene rates are between 20% and 70% higher than those calculated for the tyrrhenian terraces. the vertical tectonic rates show a decrease from e to w. in the tindari promontory the rate of mis 5.5 is 0.67 mm/y (bonfiglio et al., 2010). the holocene rate is higher, as suggested by bottari et al., (2009) from the presence of a holocene tidal notch at 4 m a.s.l.. west of the headland of tindari, holocene markers showing increasing rate are not found, presumably due to the coseismic activity of main structural features active during the pleistocene in northern sicily: the kabilianecalabrian thrust front (west of acquedolci) and the vulcano-tindari fault (east of patti) (sulli et al., 2012). further on, both coastal geomorphological and marine geology data between acquedolci and capo d’orlando demonstrate that while the mainland sector is uplifted, with the same rates both during mis 5.5 (0.34 mm/y) and the holocene (0.36 mm/y), contemporaneously the offshore area is subsiding, suggesting the existence of fault systems parallel to the coastline, separating the inner from outer sector of the continental shelf, causing different vertical movements (subsidence vs. uplift) (sulli et al., 2012). westwards, near cefalù, some fossil-bearing deposits, dated to mis 5, at relatively low altitude (29 m, antonioli et al., 2006) indicated vertical movement rates lower than 0.2 mm/y. westward, between palermo and the egadi islands, many mis 5.5 markers show a substantial stability, except for small and local vertical movements (gulf of castellammare, mauz et al., 1997 and castelluzzo plain), due to the action of transcurrent faults where uplift rates reach 0.1 mm/y (antonioli et al., 2006). 3. materials and methods the morphological features of the area were studied by multibeam echo sounder (mbes) data, acquired in different oceanographic cruises, by using both the reson seabat 8111, generating 105 beams at a frequency of 100 khz with depth range of 35-800 m, and the reson seabat 8160, which generates 126 beams with depth range of 30-3,000 m. bathymetric data were acquired and stored using the pds2000 acquisition software. sound velocity profiles were collected with the navitronic systems as-svp-25. post-processing of multi beam data was accomplished with the pds-2000 system and included the graphic removal of erroneous beams, noise filtering, processing of navigation data and correction for sound velocity. gridding of the filtered soundings was carried out to obtain the final dem (fig. 2), which provided high resolution 3d views of the sea-floor, shaded relief maps, slope maps and bathymetric cross sections. various sets of chirp and multiand singlesulli a. et al. 144 channel seismic profiles provided high resolution to high penetration data of the sedimentary succession. high resolution seismic profiles were mainly acquired employing a multi-tip sparker array, with a base frequency of around 600 hz, fired each 12.5 m. data were received with a single-channel streamer with an active section of 2.8 m, containing seven high-resolution hydrophones recorded for 3.0 s two way time (t.w.t.) at a 10 khz (0.1 ms) sampling rate. data processing was performed using the following mathematical operators: traces mixing, time variant filters, automatic gain control, time variant gain and spherical divergence correction. the resulting signal penetration exceeded 400 ms (t.w.t.) and the vertical resolution reached 2.5 m at the seafloor. medium to high penetration seismic data were acquired by using both high power sparker source coupled with singlechannel streamer and airgun coupled multi-channel streamer. the penetration ranges from 1 to 6 s (t.w.t.), with vertical resolution between 10 and 80 m. the seismic lines were interpreted using seismic facies analysis, which allowed depositional units, characterized by different seismic attributes, to be distinguished. the interpreted seismic lines were depth converted adopting average velocities derived from lithostratigraphy and sonic log data collected in the southern and western sicilian offshore. 4. geomorphological features of the northern sicily continental margin in order to explain the geomorphological and seismostratigraphic features of the north sicily continental shelf we individuate some main sectors (fig. 2), from e to w gulf of termini, gulf of palermo, offshore palermo salient, gulf of castellammare. 4.1. gulf of termini in the gulf of termini, average gradient of shelf increases sideways, up to 2.7° offshore capo zafferano, with a shelf width ranging from 1.5 km to 8 km (fig. 2). the seabed appears rather even with the exception of narrow coastal sectors where the substrate outcrops. the inner shelf is regular and steep due to the depositional slope of the holocene coastal sedimentary wedge, while the outer shelf is less steep because the holocene sediments drape a sub-horizontal seabed. the prograding coastal depositional system in the inner shelf developed during the holocene as consequence of the subaqueous delta coalescence of small rivers that flow to the coast (san leonardo, torto, imera, roccella and piletto rivers). an abrupt seaward increase of the sea bottom slope emphasizes the transition from the delta front (slope < 0.5°) to the prodelta (slope of 1°-2°). in some areas, this submarine wedge is extended almost to the shelf edge. moving far from the entry points of the sedimentary supply, towards the sides of the gulf, the inner shelf shows a rougher morphology of the sea bed characterized by break-in-slope, paleo-cliff and wave-cut terraces partly buried beneath the thin holocene sedimentary sheet and the cymodocea nodosa meadow, as offshore termini imerese, westward of the san leonardo river mouth. in the western sector of the gulf, the continental shelf is punctuated by small irregular, isolated relieves partly draped by holocene sediments. the shelf break is located at depth between 90 and 145 m. prograding pattern and straight trend are predominant, but at places a scalloped shelf break is due to canyon headscars (fig. 3). the upper slope is steeper in the western sector, where a number of submarine canyons develop with parallel thalweg, orthogonal to the isobaths. fig. 2 3d shaded relief elevation model of the north-western sicily mainland and offshore areas. the model shows the main morphostructures and geomorphologic features of the continental shelf to slope region. intraslope basin (e.g. gulf of castellammare and gulf of palermo) are bounded by structural highs of bed rock. the upper slope is scoured by a number of submarine canyons and gullies. according to the elevation scale, the continuous red belt follows the continental shelf edge. the map also shows some of the main toponyms used in this paper. the location of the figures illustrated in the paper is also shown. variability of depositional setting along the north-western sicily continental shelf (italy) ... 145 4.2. gulf of palermo in the gulf of palermo the shelf edge lies at depth of 120-150 m, and 2.3 to 7.5 km far from the coastline (fig. 2). as consequence, the average continental shelf steepness ranges between 3° in the central sector up to 8° offshore monte pellegrino. different features can be distinguished in the western sector, where the shelf is narrow and steep, and isolated and scattered rocky relieves make the seabed rough, and in the southern sector, less steep and showing a regular morphology without pronounced relieves. offshore monte pellegrino promontory, at depth of 89-92 m, 60-70 m and 35-40 m, three main concave breaks in slopes with wave-cut platforms at base document subsequent sea level stillstands during the last transgression (16-5.5 ka; fleming et al., 1998). small, isolated relieves occur in the outer shelf, with the top at depth of 75-90 m, as well as in the southern sector, where the smooth seabed is moved only by a few isolated mound. in the transition zone between the palermo and the termini gulfs, a sharp concave break in slope, several kilometers long, faces the capo mongerbino-capo zafferano promontory at water depth of 80100 m. the shelf break is as prograding and straight as erosive and very scalloped near the canyon headscars that are extensive along the western sector (fig. 4). between the oreto and the eleuterio river mouths, no evident shelf break is present: here the margin trends straight but it does not prograde. 4.3. offshore palermo salient the submerged extension of the monti di palermo structural salient, between the palermo and castellammare gulfs, displays a more extensive “structural-erosive” platform, with rougher morphology, mainly in the inner shelf (fig. 2). the continental shelf, 5 to 8 km wide, is separated, at depth of 60-70 m, by a convex break-in-slope, in inner and outer shelf. in the inner shelf a number of breaks-in-slopes linked to submerged paleo-cliff have been detected at -8 m, -15 m, -35 m, -53 m. in the outer shelf two sectors are separated by a prominent concave break-in-slope 110-120 m deep. landward of this boundary the sea floor is characterized by rills, isolated relieves and a few concave breaks-in-slopes, interpreted (lucido, 1992) as paleo-shorelines. elongated morphological relieves, parallel to the isobaths, and interspaced by narrow depressions have their tops at -75 m, -85 m, -95 m and -105 m. on the base of carbonate cements, recovered from the feature at -75 m (lucido, 1992), these relievies have been interpreted as beach rocks, recording subsequent sea level still stands during the holocene transgression. seaward of the 110-120 m deep break-in-slope, the shelf margin is characterized by a sub-horizontal surface sloping at about 0.5°, up to 4 km wide. in this sector the seabed is represented by a paleo-wave-cut terrace draped by a thin wedge of holocene sediments, tapering towards the shelf edge. the shelf break, about 140-150 m deep, shows mostly prograding geometry, except offshore capo gallo and punta raisi and in the canyon headscars, here less extensive than in the adjacent gulfs (fig. 2). 4.4. gulf of castellammare the gulf of castellammare is the largest coastal embayment in north-western sicily, bounded to the east by the palermo mountains and to the west by the san fig. 3 along the gulf of termini the shelf break shows almost always a linear trend but, in the western sector, it displays a scalloped pattern because of small canyon headscars (3d shaded relief model, view from the nord). fig. 4 extensive slope failures carve the upper slope sea floor in the western sector of the gulf of palermo. here, small and large canyon heads breach the shelf edge that assumes a very scalloped pattern. a) shelf break; b) submarine slide headscar; c) canyon thalweg (3d shaded relief model, view from east). sulli a. et al. 146 vito lo capo peninsula (fig. 1). here, a sedimentary basin, more than 1000 m deep, trends in a general north-south direction across the upper slope. the continental slope deepens to 1000 m, with gradient of 4-9°, and is incised by numerous gullies and major canyons (fig. 2). slumping, scours and small turbiditic fans are located at depths from 200 to 800 m, confirming the occurrence of gravity-driven slope instability (agate et al., 2005). the coastal belt includes several rocky cliffs along the promontories bordering the gulf of castellammare (capo san vito and capo rama), while a long beach, up to several tens of meters wide, extends in the central sector. the continental shelf is wave-dominated, with a mean tidal range of about 21 cm (istituto idrografico della marina, 1982). the predominant wave direction is from northwest, while the southwest and southeast are less frequent. storm waves occur in winter to spring (november to may) and vary in approach direction from northwest to northeast. the continental shelf is 8 km width on the central part and in the eastern side of the gulf, but it is very narrow or absent along the rocky cliffs of the san vito lo capo peninsula. the inner shelf, with gradient of 0.7°-1.0°, encompasses 0-50 m, while the outer shelf has a slope of 0.9°1.2°. the central-western sector of the inner shelf is characterized by convex and concave breaks-in-slope bounding wave-cut terraces and paleo-cliffs; the seabed is punctuated by rocky outcrops and small biohermes. the holocene coastal wedge is thicker in the central-eastern sector where the sea bed is rather even and displays an up to 2° gradient in the inner shelf; the bathymetric gradient decreases seawards. the present day shelf margin morphology arises from a former wave-cut terrace mostly buried beneath a thin sheet of holocene sediments. the shelf break lies at depth of 130-190 m and shows a scalloped shape in the southeastern sector because of several gullies and canyon headscars indenting the shelf margin (fig. 5). out of the canyon headscars, the shelf break is a prograding, depositional straight feature. along the san vito peninsula the shelf break lies at depth of 60-100 m because of structural control and abundant retrogressive mass movement along the upper slope. in the small bay of san vito the continental shelf is very narrow and the shelf break lies at depth of 80-100 m reflecting a structural control. 5. seismostratigraphic setting and features along the study area the continental shelf is characterized by an extensive unconformity eroding a seaward dipping mixed (lithoclastic/bioclastic) pleistocene succession. in the seismic reflection profiles these horizons can be assembled into packages of reflectors showing specific seismic attributes (seismostratigraphic units). as several authors have documented along other mediterranean margins (chiocci et al., 1991; correggiari et al., 1996; hernandez-molina et al., 1994; tesson et al., 2000; trincardi & field, 1991 among others), the cyclic change of these attributes almost certainly is a response to subsequent sedimentary environment variations controlled by quaternary eustatic sea-level fluctuations. the unconformity is a subaerial erosional surface formed during the last eustatic sea level fall ended in the lgm (20-18 ka) and shaped again during the late quaternary-holocene sea level rise that generated a “transgressive surface of erosion” (nummedal & swift, 1987). as consequence of this polygenic genesis, the unconformity is punctuated by incised valley, submerged cliff and isolated topographic relieves corresponding to outcrops of the rocky substrate, mud volcanoes, biogenic mounds. this prominent unconformity is in turn the lower boundary of the sedimentary succession deposited during the last eustatic change (last 125 ky), which can be interpreted as a iv order depositional sequence (late quaternary depositional sequence, lqds). in the lqds we recognized four systems tracts, separated by basin-wide key surfaces identified by lateral terminations of reflectors, and deposited during specific segment of the last sea level change. the lqds extends above the continental shelf and upper slope along the different sectors of the margin with considerably variable internal geometry and stratigraphic relationships with the underlying units. 5.1 gulfs of termini and palermo in these sectors the stratigraphic features of the lqds and underlying pleistocene succession are very uniform, so they will be illustrated together. we will describe the systems tracts from the older to the younger. deposits accumulated during the sea level fall form progradational sedimentary wedges perched along the shelf margin (figs. 6-7). they are imaged by high resolution seismic profiles with reflection-free seismic pattern or thin, oblique tangential/parallel reflectors, 3.5° seaward sloping, locally involved in slumping. wedges are up to 50 ms (t.w.t.) thick and up to 2 km wide; land fig. 5 3d shaded relief model (view from north-west) showing several gullies and canyon headscars indenting the shelf break along the southeastern sector of the gulf of castellammare. variability of depositional setting along the north-western sicily continental shelf (italy) ... 147 ward they onlap the late pleistocene erosive unconformity at 110-130 m of water depth, about 15 km far from the present day coastline along the gulf of termini. we interpreted these wedges as forming the falling stage systems tract (fsst). along the shelf edge progradational wedges showing oblique parallel horizons form the lowstand systems tract (lst, fig. 8). seaward the wedges pinchout at water depth of 150-190 m; the thickness is up to 100 ms (t.w.t.). these wedges formed during the lgm lowstand (20-18 ka) and are stacked with the fsst along the shelf margin. in plain view, fsst and lst wedges extend along the shelf margin for several km. they are absent only in the canyon headscars and, in the gulf of palermo, along a shelf break segment, about 5 km long, between the oreto and the eleuterio canyon. samples coming from the upper portion of the prograding shelf margin wedges reveals coarse grained bioclastic sands containing benthic foraminifera deposited in a very shallow water environment during a cold period (catalano et al., 2011b). at the top both the fsst and the lst are truncated by the transgressive surface of erosion (t.s.e.) that downslope merge into a drowing surface (fig. 8). landward, in the inner shelf, this surface is scoured by a few incised valleys up to one hundred meters wide and ten meters deep. moving toward the inner shelf, a transgressive sedimentary wedge lies above the t.s.e.; the wedge displays even subparallel reflection configuration and thins seaward generating an apparent truncation in the seismic profiles. this wedge, interpreted as the transgressive systems tract (tst) is very thin in the gulf of palermo (fig. 8) and thicker in the gulf of termini imerese (fig. 7) where three backstepping parasequences can be recognized that are bounded by flooding surfaces. the lowermost parasequence lies above an extensive submerged wave cut terrace; the uppermost parasequence is thicker in the sector offshore the mouths of the imera and torto river. a downlap surface (fig. 7) marking the transition between tst and highstand system tracts (hst) seismic units, corresponds to the maximum flooding surface (sensu vail, 1987). the overlying sedimentary wedge, interpreted as the hst, is formed by thin, continuous and aggrading horizons evolving upwards to slightly prograding reflectors. landward this unit is continuous with the modern coastal sedimentary wedge. in front of the imera river mouth the hst deposits appear involved in creeping interpreted as syn-sedimentary gravity features. in this sector the sea floor instability is promoted by high sedimentary supply, earthquakes, fluid seepage. alternatively these structures were interpreted as due to waves, hyperpycnal flows and bottom currents (urgeles et al., 2011). as consequence of the wedge geometry, the hst thickness regularly increases landward up to 35 m in front of the main river mouths. at places seaward exten fig. 7 high resolution seismic profile (sparker 1 kj) showing the seismic units and facies interpreted in the quaternary succession. interbedded, progradational wedges (lst) are present along the outer shelf; sb: lower sequence boundary of the lqds; f: fault; s: sliding plane (see text for more detail; modified from pepe et al., 2003). fig. 6 general stratigraphic pattern of pleistocene seismic units buried beneath the continental shelf in the gulf of termini (as worked out from multi-channel seismic profiles. sulli a. et al. 148 sion of this unit extends up to the shelf edge, completely burying the underlying tst unit. the thickness of the tst and hst deposits rapidly varies along the margin resulting thicker in the central sector of the gulfs and in front of the entry points along the coast; otherwise, their thickness thins towards the gulf edges. 5.2. offshore palermo salient in this area, inner and outer continental shelf show very different setting. along the inner shelf rocky substratum outcrops very extensively, truncated by an erosional surface; in the high resolution seismic profiles this surface is imaged as the reflective top of the acoustic basement. along the outer shelf the sedimentary quaternary succession is present, and in the upper part we recognized deposits pertaining to the lqds (fig. 9). along the shelf margin, fsst and lst deposits are stacked generating sedimentary prograding wedges with thin, oblique parallel or tangential downlapping reflectors; reflection-free seismic configuration is also present (fig. 9). prograding wedges extend downslope up to more than 200 m water depth and landward onlap the pleistocene succession at water depth of 110-120. upwards, prograding reflector show lateral termination of toplap or erosional truncation. along the shelf edge the prograding wedge is almost continuous for about 15 km displaying a maximum extension of 2 km and a thickness up to 30 m. the shelf edge is depositional and corresponds to the offlap break of the outermost prograding wedge, except around la barra (fig. 10) where a deeper, erosive, structural shelf break is also present seaward of the depositional one (agate et al., 2004). along the inner shelf fsst and lst deposits are absent. in this sector tst and hst units are very thin, often thinner than seismic resolution but they have been documented by samples (ferretti et al., 1994). 5.3. gulf of castellammare except the san vito peninsula offshore, the continental shelf of the castellammare gulf is the result of the quaternary progradation of a clastic sedimentary succession truncated by the erosional surface formed during the last glacioeustatic fluctuation. above this unconformity the deposits pertaining to the lqds can be subdivided into four units (fig. 11), showing different sedimentary and seismostratigraphic expression in each sectors of the basin. the lower boundary is represented on the continental shelf by an unconformity surface of subaerial exposure and fluvial down-cut, and a correlative paraconformity on the upper slope, characterised by the occurrence of multiple linked scars. on the shelf, at 70-90 m below the sea level, the lower boundary is a polygenic regressive surface of erosion, extending landwards to a subaerial unconformity, and seawards to a marine erosional surface. morphological steps and terrace-like features characterize the fig. 8 in the palermo and termini gulfs, sedimentary progradational wedges along the shelf margin show reflection-free seismic facies or high frequency, low amplitude downlapping reflectors. almost two progradational wedges are stacked along the shelf margin. along the upper slope, quaternary horizons are truncated by a canyon incision of a tributary of the eleuterio canyon (sparker 1 kj seismic profile). variability of depositional setting along the north-western sicily continental shelf (italy) ... 149 lqds lower boundary, cut through by a sharp network of incisions (fig. 11), connecting the mainland incised valleys to the main submarine canyons. the fsst has been identified in the outer shelf (fig. 11), where it onlaps the lqds lower boundary, at an average distance of 9 km from the present shoreline, and at depths of 110-120 m. the prevalent seismic facies is characterised by complex sigmoid-oblique reflectors and in rare cases oblique-parallel. reflectors show medium amplitudes and are interrupted by rotational faults or affected by slope failures (fig. 11). the amplitude and the lateral continuity of seismic horizons decrease seawards. a shelf margin wedge forming the lst (fig. 11) is situated in the eastern and central sector of the gulf, near the present-day shelf edge, and in the upper slope. fig. 9 seismic section crossing the palermo salient (offshore bay of carini). the seismic profile (sparker 1 kj) shows both the upper slope and the continental shelf where two distinct sectors can be separated; a prominent break-in-slope divides the two sectors. along the outer shelf the sea floor is sub-horizontal, in the inner shelf it assumes an about 1.5° slope. according to our interpretation, the top of acoustic basement corresponds to the base of plio-pleistocene sequence. this horizon is affected by folding and reverse faults. inside the plio-pleistocene sequence, a prominent unconformity separates two seismostratigraphic units. the lower one (zanclean in age?) displays a predominant reflection-free seismic facies and appears deformed. fig. 10 seismic reflection profile (sparker 1 kj) at the north-east end of the palermo salient. here the continental shelf widens to 8.5 km and displays a very irregular morphology characterized by an inner and an outer sectors separated by a prominent break-in-slope partly buried beneath a stack of prograding sedimentary wedges. these downlapping, regressive deposits does not extend to the shelf margin where a landward sloping abrasion surface outcrops at the sea bed. sulli a. et al. 150 it shows predominantly oblique, medium and high amplitude reflectors of good lateral continuity, with foresets gradients ranging from 4° to 10°. seawards, reflectors become parallel to the downlap surface and merge into the high amplitude and laterally continuous upper slope reflectors. at the base of these shelf-perched units, chaotic seismic facies and small superimposed mounds have been identified in close association to gullies and canyons, cutting the outer shelf.  the depocenters of fsst and lst lengthen parallel to the paleomargin of the continental shelf in an e-w direction but the greatest thickness, exceeding 40 ms (t.w.t.), is identified near to the canyon heads. the top of the shelf margin units is a transgression erosional surface (transgressive surface of erosion, fig. 11); nummedal & swift, 1987) replaced in the upper slope by a drowning surface, without erosional features. the tst (fig. 11) is bounded at the base by an irregular transgressive surface of erosion, with wave-cut terraces and channel features, reaching 500 m in width and 10 m in depth. the most striking feature is the retrogradational pattern of three parasequences separated by mixed (flooding and erosional) surfaces, extending laterally throughout the area (agate et al., 2005). the three sub-units display a progressive landward shift of the coastal onlaps, which encroach between 98 m to 90 m, 75 m to 63 m, and 60 m to 45 m water depths. the downlap surface at the transition between tst and hst corresponds to the maximum flooding surface (sensu vail, 1987). it correlates with a very wide and strongly reflective horizon on the slope, the seismic expression of the condensed section (sensu loutit et al., 1988). in the inner shelf between the mouth of the nocella river and the overhanging coast of capo rama and off the freddo and jato rivers, acoustic masking affects this surface (fig. 11) suggesting the presence of biogenic gas. the upper stratigraphic limit of the hst is represented by the present day depositional surface (sea bottom). the hst is marked by a thick prograding wedge, which extends continuously from the inner as far as the middle-outer shelf (fig. 11). analysis of the highresolution seismic profiles has enabled the subdivision of hst into two parasequences, separated by an erosional surface. the lower parasequence shows faintly prograding geometries, shingled and oblique parallel, while the upper is oblique tangential. the modern depositional surface truncates the topsets of the last parasequence, suggesting the position of the modern fairweather base level at 20 m of depth. in the dip sections, the predominant seismic facies is oblique-sigmoid, with high amplitude and good laterally continuous reflectors, which merge seawards with a slope of approximately 1,5°. in the strike sections, seismic profiles show lateral variations of the facies: lobed facies with internal configurations of the hummocky type overlap with tabular facies faintly clinostratified dipping towards the southwest. in the inner shelf, opposite the freddo and the jato rivers, hst is deformed by upslope migrating wave structures (fig. 15 in agate et al., 2005), related to the fig. 11seismic reflection profile (below; sparker 1 kj) and stratigraphic interpretation of the middle (?)-late quaternary sedimentary succession buried beneath the continental shelf in the gulf of castellammare. the interpretative model images also a possible correlation to the deposits outcropping along the coastal zone (see text for more detail; modified from agate et al., 2005). variability of depositional setting along the north-western sicily continental shelf (italy) ... 151 acoustically transparent lenticular bodies, with an erosive base. these morphologies lie at 2-3 km seaward the mouths of the freddo and the jato rivers, within a band trending w-e in subsurface depths from 75 to 25 ms (t.w.t.), where the thickness of the hst exceeds 25 m close to the river mouths. pockmarks in the subsurface occur up-dip the most significant wipe-out zones and they point out the existence of gas-charged fluid expulsion. the tst has four depocenters, aligned parallel to the shoreline off major river mouths, as in the central gulf, or at the base of the steep paleocliff in the eastern gulf off capo rama. close to the western edge of the castellammare gulf the continental shelf is narrower and the seabed is a marine transgressive surface cut above the pre-quaternary rocky substrate, at places floored by a very thin, shallow sedimentary cover. 5.4. structural features during the pleistocene, faults, as well as folded structures, exerted a control on the morphology of the present day coastal areas and shelf-slope system, as for the submarine canyons and the mass failure processes. in the termini gulf e-w to ne-sw-trending normal faults are prevailing. very recent nw-se vertical faults displace the buried quaternary succession in the western sector, being also seismically active. in the palermo gulf nnw-sse fault systems, with a downthrow ranging from some tens to 150 m, are prevalent off monte pellegrino and in the southeastern side (off the head of the eleuterio canyon), whilst to the north, between capo gallo and la barra, faults appear to have a dominant nne-ssw trend. pockmarks and mounds are often aligned with the fault systems trends. in the monti di palermo offshore main fault systems are and near vertical, oriented ene-wsw (see la barra structural high) or nnw-sse, dipping nneward. wnw-ese trending fault systems were recognized parallel to the coastline. in the carini bay, inner continental shelf is characterized by n-s and nne-ssw fault systems with variable downthrow. in the gulf of castellammare the continental shelf develops in the southern part of a tectonic depression that formed during the quaternary (fig. 11). it is bounded to the east by n-s to nnw-sse, with some hundreds of meters of downthrow, along which meso-cenozoic carbonate succession is juxtaposed to plio-quatermary deposits; to the south pre-pliocene deposits are intensely folded and dissected by both reverse and extensional n-s to nnw-sse faults, even very recent; to the west by nne-ssw, ns and nnw-sse faults. 6. discussion several evidences highlight that the north sicily continental margin is tectonically immature. the plioquaternary tectonic evolution of the nw sicily margin produced the development of a morphostructural setting characterized by a series of depressions (intraslope basins) separated by structural highs along the margin (agate et al., 1993), as result of differential uplift and subsidence during neogene to recent times. recent tectonic activity is testified by neotectonic elements and seismic activity (fig. 1), calculated uplift rates, depositional alternating with structural edge, present lack of highstand-transgressive systems tracts in the oldest depositional sequences recognized along the margin. furthermore, the occurrence of pockmarks and mounds probably consisting of authigenic carbonates above faulted and folded strata suggests a local relationship between structural control and fluid escape. some of the tectonic features could have represented a preferential escape route for fluids as evidenced by the pockmarks. pockmarks may in turn trigger mass failures as evidenced by the headscarps observed below them (lo iacono et al., 2011). the structural features are possibly associated with the recent tectonics mapped on land (catalano et al., 2011 a, b) as well as the widespread seismicity of the margin. as a matter of fact tectonic activity persists today with the occurrence of shallow (<25 km) seismic events of low to moderate magnitude along an e-w trending belt located along the continental slope. the focal mechanisms related to the main seismic shocks are in agreement with a dominant ne-sw fault trend coupled with a nw-se compressive offset direction. a minor cluster in the monti di palermo offshore well match with the extensional ene-wsw trending extensional faults. uplift of the northern sicily shelf and surrounding areas during the pleistocene is testified also by the pleistocene regressive coastal deposits in the western sector of the margin (mauz et al., 1997; arces et al., 2000), and the pleistocene deposits, outcropping close to the study area, which are uplifted tens of metres (hugonie, 1982). moreover, uplift of the continental margin, as a consequence of thermal perturbation due to the thinning of the lithosphere which is not compensated by local isostasy, is predicted by forward modeling (pepe et al., 2003), thus constraining the late neogene to recent tectonic and stratigraphic evolution of the margin. therefore, it is evident that along the north sicily continental margin eustatic and tectonic processes combine to cause both relatively shortand long-term sea-level changes which control the space available for sediments, forming a number of depositional sequences from the early (?) pleistocene to the holocene. 6.1. effects of eustatic sea-level changes subsequent, rapid sea level changes impacted the continental margins as consequence of astronomically forced, worldwide climatic changes occurred during quaternary age. as documented by several studies on oxigen isotopes (chappel & schackleton, 1986; imbrie et al., 1984; williams et al., 1988), middle-late quaternary sea-level changes have been asymmetrical fluctuations characterized by slow falling stages (1 mm/y) followed by fast rising stage (1 cm/y); average amplitude of cycles was 100-150 m and the period was about 100200 ky. as we have illustrated, the internal geometry of the lqds well documents the sedimentary response to specific segments of the last glacio-eustatic fluctuation. the effects of eustatic changes appear less evident in the more ancient deposits where complete depositional sequences have not been detected. according to us, the interpreted seismic profiles does not image past shelfal tst and/or hst deposits and subsequent erosional surfaces are not clearly distinguishable. otherwise, beneath the lqds, oblique seawards dipping layers only are preserved with small, interbedded, prosulli a. et al. 152 grading wedges. we hypothesize these deposits recorded falling and lowstand depositional stages respectively (caruso et al., 2011). a possible explanation for this could be the tectonic evolution of the margin. according to mougenot et al., (1983), in a prograding type shelf margin, the sedimentary response to sea-level fluctuations is better preserved for the influence of important subsidence. it does not seems the case of the nw sicily offshore where high frequency sea-level changes punctuated a slow, long-lasting tectonic uplift. even if the effects of sea-level changes are ubiquitarious, thickness and internal geometry of lqds are also controlled by margin physiography, sedimentary input and local hydrodynamic conditions. tst and hst deposits are thicker and extensive in the central sectors of gulfs where a major number of sedimentary entry points are present. this aspect contributes to differentiate the morphostratigraphic pattern of depositional shelves, where tst and hst deposits are extensive and well developed, from structural-erosive ones where tst and hst deposits are absent or very condensed (fig. 12). 6.2. different types of continental shelf in physiographic setting as that bordering majority of the tyrrhenian sea, mainly characterized by a well-defined continental shelf-slope system associated to a pronounced shelf break, during the late quaternary sea level changes type 1 depositional sequences (vail, 1987) developed, characterized by enhanced lower sequence boundary. however, even if glacio-eustacy is an ubiquitarious process, different types of depositional settings are distinguished in the shelfal sectors, mainly depending on subsidence, local climatic conditions and total sediment supply; moreover, localized features occur due to continental shelf palaeo-topography and distribution of entry points along the migrating shoreline. in fact, all these factors determine both location and depth of sedimentary deposits generated during the eustatic cycle. in the investigated area the analysis of stratal pattern, lithological assemblages and architecture of depositional sequences, the identification of different stratigraphic and morphostructural settings along the margin, led to the recognition of two main types of continental shelf (fig. 12), structural-erosive and depositional shelves respectively. for each of these types, interaction of tectonics, sealevel change and different types of sedimentary inputs developed different types of prograding shelf margin and different internal geometry of lqds. type 1 are predominantly rocky shelves, where seabed corresponds to polygenic erosional surfaces modeled on a pre-calabrian bedrock, in places covered by thin layers of holocene deposits. this type is found in the structurally high areas in the monti di palermo offshore and around the main rocky headlands (capo san vito, monte catalfano). they can be divided into two subtypes (fig. 12): 1a are rocky shelves accompanied by a moderate frontal sedimentary prism; 1b are rocky shelves with a structural edge (the sedimen fig. 12 cartoons image the stratigraphic setting of the middle (?)-late quaternary depositional units detected by means of seismostratigraphic analysis in different sectors of north-western sicily continental shelf: 1a) bay of carini; 1b) la barra salient; 2a) gulf of palermo and gulf of castellammare; 2b) gulf of termini imerese. quaternary deposits. the illustrated different settings are controlled by geological processes discussed in the text. variability of depositional setting along the north-western sicily continental shelf (italy) ... 153 tary prism, although present, does not extend to the edge). type 2 are depositional shelves (prevalent or exclusive sedimentary origin), in which the pre-calabrian bedrock is buried by a considerable thickness of quaternary sediments and does not significantly influence the sea floor morphology; seaward progradational outbuilding contributes more than one half of the entire shelf width. also in this case it is possible to distinguish two subtypes (fig. 12): 2a are shelves in which the substrate deepen regularly seaward; 2b are shelves in which the structural setting determines a substrate uplift in correspondence of the current position of the shelf break (in this case the substrate is at shallow depths, providing a support for sedimentary prism accumulate and expand). the depositional shelves occur in the castellammare, palermo and termini imerese gulfs representing the 2a type, the type of continental shelf most widespread in the area. in this type of shelf we can find, in the inner platform, thick holocene sedimentary wedges that are absent in the shelves of the first type. when we compare stratigraphic architecture and depositional setting observed in the north-western sicily offshore with other tyrrhenian margins, there is a striking similarity mostly with the offshore calabria and campania. in these sectors we can observe depositional (type 2) shelves along the gulfs, e.g. gulf of s. eufemia (chiocci et al., 1989) and gulf of salerno (aucelli et al., 2012); otherwise, predominantly rocky shelves (type 1) are widespread in front of morpho-structural salient, e.g. punta licosa (trincardi and field, 1991; ferraro et al., 1997) and capo suvero (mongardi et al., 2004). this type (1) of continental shelf, characterized by prograding shelf margin deposits and absence of thick coastal prisms, is also common along linear margin (without coastal embayment) with scarce sedimentary supply, e.g. marettimo channel, in the egadi islands area (d’angelo et al., 2004), and tuscan islands (roveri & correggiari, 2004), or along epicontinental shelf separated by the mainland, e.g. adventure bank (colantoni et al., 1985). a similar variability of continental shelves, as that we illustrated respect to the nw sicily offshore, has been detected by corradi et al., (1984), along the ligurian sea margin. 6.3. geological evolution the trend to tectonic uplift recorded along the margin, documented by already described stratigraphic relationships and in agreement with the outcrop altitudes of paleo-shorelines along the coast, seems to start with the ionian (middle pleistocene). previously, the sea recorded an episode of deepening that has allowed transgression during the calabrian in a large area of the north-western sicily, where now a neritic succession some tens of meters thick outcrops, discordant on a pre calabrian tightly deformed substrate (ruggeri, 1978). the deposition of this succession marks the beginning of the formation of the continental shelf in northwestern sicily margin, which, by the end of the calabrian, under the influence of glacioeustatic fluctuations and slow uplift, produced a frontal accretion of the margin of some km (<10 km). the recorded deepening of the margin at the beginning of the calabrian and the subsequent uplift, which produced the emersion of the calabrian portion of the continental shelf, now outcropping up to about 100 m a.s.l., may be related to the succession of compressional and extensional tectonic events recorded in the margin during the plio-quaternary. 7. conclusions the integrated analysis of morphobathymetric and high resolution seismic data collected on the continental shelf to slope system was used to illustrate the present stratigraphic and morphostructural setting of the north sicily continental margin and its late neogene-quaternary geological evolution. we recognized an upper pleistocene-holocene sedimentary succession, deposited during the last eustatic change (last 125 ky). this succession, interpreted as a iv order depositional sequence (lqds), shows along the different sectors of the margin considerably variable internal geometry and different stratigraphic relationships with the underlying units. the lower boundary of the lqds is represented by a subaerial erosional surface formed during the last eustatic sea level fall, ended in the lgm (20-18 ka), and shaped again during the late quaternary-holocene sea level rise. this unconformity lies at the top of a seaward dipping pleistocene succession whose depositional architecture is in turn controlled by quaternary eustatic sealevel fluctuations. even if depositional sequences in this margin are the result of the interaction between sea level changes and sedimentation, the tectonic activity has played a key role, not only to determine the different characters of each sequence in different areas, but also in the creation of different types of continental shelves. as a consequence we recognize different types of continental shelf with different stratigraphic and morphostructural settings, identified on the basis of the occurrence and thickness of the lqds deposits: a) type 1, predominantly rocky shelves, both accompanied by a moderate frontal sedimentary prism (1a) and with a structural edge (1b), in the structural highs of the monti di palermo offshore and around the main rocky headlands (capo san vito, monte catalfano); b) type 2, depositional shelves, in the castellammare, palermo and termini imerese gulfs, with a regular seaward deepening of the substrate (2a) and with a substrate uplift at the shelf break (2b). a general tectonic uplift during the pleistocene, together with the episodic alternation of extensional and compressional events, often with strike-slip component, is responsible for the thickness and facies variation and geomorphological features, both onland, where residual pleistocene marine deposits today outcrops, and in the continental shelf, where most of the depositional sequences developed and are now recognized. as well tectonic activity exerted a control on the geomorphological features of the present day coastal areas and shelf-slope system (e.g. pockmarks and mounds) as well as for the submarine canyons and the mass failure processes. aknowledgments we wish to acknowledge the italian national research projects magic (marine geological hazard along sulli a. et al. 154 the italian coast), funded by the italian civil protection department, and carg (geological maps of italy) funded by the italian geological survey (ispra). we thank the captains and the crews of the r/v “urania”, ‘‘thetis’’ and ‘‘universitatis’’ for their kind assistance during the surveys. precious revisions of francesca budillon and paolo orrù and useful suggestions of the editor allow us to largely improve the early version of this paper. references agate m., catalano r., infuso s., lucido m., mirabile l., sulli a. (1993) structural evolution of the northern sicily continental margin during the plio-pleistocene. in: max m.d., colantoni p. (eds.), geological development of the sicilian-tunisian platform. unesco reports on marine science, vol. 58, 25-30. agate m., beranzoli l., braun t., catalano r., favali p., frugoni f., pepe f., smriglio g., sulli a. (2000) the 1998 offshore nw sicily earthquakes in the tectonic framework of the southern border of the tyrrhenian sea. mem. soc. geol. it., 55, 103-114. agate m., infuso s., lucido m., mancuso m. (2004) terrazzi deposizionali sommersi al largo della baia di carini (sicilia nord-occidentale). in: chiocci f.l., d’angelo s., romagnoli c., atlante dei terrazzi deposizionali sommersi lungo le coste italiane. mem. descrittive della carta geologica d’italia, 58, 115124. agate m., mancuso m., lo cicero g. (2005) late quaternary sedimentary evolution of the castellamare gulf (north-western sicily offshore). bollettino soc. geol. it., 124, 21-40. antonioli f., ferranti l., lambeck k., kershaw s., verrubbi v., dai pra g. (2006) late pleistocene to holocene record of changing uplift rates in southern calabria and northeastern sicily (southern italy, central mediterranean sea). tectonophysics 422, 23-40. arces m., aversa s., lo cicero g., nocilla n. (2000) the pleistocene ‘‘calcareniti di marsala’’: geotechnical and sedimentological characterisation. mem. soc. geol. it., 55, 483-489. astraldi m., conversano f., civitarese g., gasparini g.p., ribera d’alcalà m., vetrano a. (2002) water mass properties and chemical signature in the central mediterranean region. j. marine syst., 3334, 155-177. aucelli p.c., amato v., budillon f., senatore m.r., amodio s., d’amico c. da prato s., ferraro l., pappone g., ermolli e.r. (2012) evolution of the sele river coastal plain (southern italy) during the late quaternary by inland and offshore stratigraphical analyses. rendiconti lincei scienze fisiche e naturali, 22 (2), doi 10.1007/s12210-0120165-5. avellone g., barchi m.r., catalano r., gasparo morticelli m., sulli a. (2010) interference between shallow and deep-seated structures in the sicilian fold and thrust belt, italy. journal of the geological society 167, 109-126. baghi g. et al. (1980) dati geologici preliminari sul bacino di cefalù (mar tirreno). in u.o. bacini sedimentari 1980. ateneo parmense acta nat., 16, 3-18. bonfiglio l., mangano g., pino p. (2010) the contribution of mammal bearing deposits to timing late pleistocene tectonics of cape tindari (ne sicily). rivista italiana di paleontologia, 116, 150-166. bottari c., d’amico m., maugeri m., d’addezio g., urbini s., marchetti m., privitera b. (2009) on the tracks of the ancient harbour of tindari (ne sicily). mediterranee, 112, 69-82. caruso a., cosentino c., pierre c., sulli a. (2011) sea-level changes during the last 41,000 years in the outer shelf of the southern tyrrhenian sea: evidence from benthic foraminifera and seismostratigraphic analysis. quaternary international, 232, 122-131. catalano r., d’argenio b., montanari l., morlotti e., torelli l. (1985) marine geology of the nw sicily offshore (sardinia channel) and its relationships with mainland structures. boll. soc. geol. it., 104, 207-215. catalano r., agate m., basilone l., di maggio c., mancuso m., sulli a., et al. (2011a) note illustrative della carta geologica d’italia alla scala 1:50.000. f. 593, castellammare del golfo. ispra, pp. 239. catalano r., avellone g., basilone l., contino a., agate m. et al. (2011b) note illustrative della carta geologica d’italia alla scala 1:50.000. f. 609-596, termini imerese-capo plaia. ispra, pp. 224. chappell j., shackleton n.j. (1986) oxygen isotopes and sea level. nature 324, 137-140. chiocci f.l., d’angelo s., orlando l., pantaleone a. (1989) evolution of the holocene shelf sedimentation defined by high-resolution seismic stratigraphy and sequence analysis (calabro-tyrrhenian continental shelf. mem. soc. geol. it, 48, 359-380. chiocci f.l., orlando l., tortora p. (1991) small-scale seismic stratigraphy and paleogeographical evolution of the continental shelf facing the se elba island (northern tyrrhenian sea, italy). journal of sedimentary petrology, 61 (4), 506-526. colantoni p., cremona g., ligi m., borseti a.m. and cati f. (1985) the adventure bank (off southwestern sicily): a present day example of carbonate shelf sedimentation. giornale di geologia, 3, 47 (1-2), 165-180. corradi n., fanucci f., fierro g., firpo m., picazzo m., mirabile l. (1984) la piattaforma continentale ligure: caratteri, struttura ed evoluzione. in: p.f. oceanografia e fondi marini, sottoprogetto risorse minerarie, rapporto tecnico finale. arti grafiche e. cossidente & f.lli, roma, 34 pp.. correggiari a., roveri m., trincardi f. (1996) late pleistocene and holocene evolution on the north adriatic sea. il quaternario, 9, 697-704. d’angelo s., lembo p., sacchi l. (2004) terrazzi deposizionali sommersi al largo dell’isola di favignana (isole egadi). in: chiocci f.l., d’angelo s., romagnoli c. (a cura di), atlante dei terrazzi deposizionali sommersi lungo le coste italiane. mem. descrittive della carta geologica d’italia, 58, 125-132. demirov e., pinardi n. (2002) simulation of the mediterranean sea circulation from 1979 to 1993. part i: the interannual variability. j. mar. syst., 33-34 (c), 23-50. fabbri a., gallignani p., zitellini n. (1981) geological evolution of the peri-tyrrhenian sedimentary bavariability of depositional setting along the north-western sicily continental shelf (italy) ... 155 sins of mediterranean margins. in: wezel fc (ed.), sedimentary basins of mediterranean margins. tecnoprint, bologna, italy, 101-126. ferranti l., antonioli f., anzidei m., monaco c., stocchi p. (2010) the timescale and spatial extent of vertical tectonic motions in italy: insights from relative sealevel changes studies. journal of the virtual explorer, electronic edition. issn: 1441-8142 36, paper 30. ferraro l., pescatore t., russo b., senatore m.r., vecchione c., coppa m.g., di tuoro a. (1997) studi di geologia marina del margine tirrenico: la piattaforma continentale tra punta licosa e capo palinuro (tirreno meridionale). boll. soc. geol. it., 116 (3), 473-485. ferretti o., immordino f., ribotti a., lucido m., severino v., buonacore b. (1994) geomorphological and sedimentological characterisation of the baia di carini and of the tract off isola delle femmine and capo gallo (north-western sicily). memorie descrittive della carta geologica d'italia, 70, 115-134. fleming k., johnston p., zwartz d., yokoyama y., lambeck k., chappell j. (1998) refining the eustatic sea-level curve since the last glacial maximum using farand intermediate-field sites. earth and planetary science letters, 163, 327-342. giunta g., luzio d., agosta f., calò m., di trapani f., giorgianni a., oliveri e., orioli s., perniciaro m., vitale m., chiodi m., adelfio g. (2009) an integrated approach to investigate the seismotectonics of northern sicily and southern tyrrhenian. tectonophysics, 476, 13-21. hernandez-molina f.j., somoza l., rey j., pomar l. (1994) late pleistocene-holocene sediments on the spanish continental shelves: model for very high resolution sequence stratigraphy. mar. geol., 120, 129-174. hugonie m.g. (1982) mouvements tectoniques et variations de la morphogene`se au quaternaire en sicile septentrionale. rev. geogr. phys. dyn., 23, 3-14. imbrie j., hays j.d., martinson d., mcintyre a., mix a., morley j., pisias n., prell w., shackleton n.j. (1984) the orbital theory of the pleistocene climate support from a revised chronology on the  18 o record. in: berger a. l., imbrie j., hays j., kukla g., saltzman b. eds., milankovitch and climate. dordrecht, reidel, 1, 269-305. istituto idrografico della marina (1982) atlante delle correnti superficiali dei mari italiani. istituto idrografico della marina, pp. 22. lo iacono c., sulli a., agate m., lo presti v., pepe f., catalano r. (2011) submarine canyon morphologies in the gulf of palermo (southern tyrrhenian sea) and possible implications for geo-hazard. mar. geophys. res., 32 (1-2), 127-138. loutit t.s., hardenbol j., vail p.r., baum g. r. (1988) condensed sections, the key to age dating and correlation of continental margin sequences. in: wilgus c.k., hastings b.s., kendall c.g. st. c., posamentier h.w., ross h.c.a. & van wagoner j.c. eds., sea level changes an integrated approach. sepm special publication, 42, 183-213. lucido m. (1992) geomorfologia della piattaforma continentale tra torre del pozzillo e torre mondello (sicilia nord-occidentale). naturalista sicil. 16(1/2), 91-107. martinson d.g., pisias n.g., hays j.d., imbrie j., more t.g. jr., shackleton n.j. (1987) age dating and the orbital theory of the ice ages: development of a high-resolution 0 to 300.000-year chronostratigraphy. quaternary research, 27, 1-30. mauz b., buccheri g., zoller l., greco a. (1997) middle to upper pleistocene morphostructural evolution of nw sicily coast: thermoluminescence dating and paleontological-stratigraphical evaluations of littoral deposits. palaeogeogr. palaeoclimatol. palaeoecol., 128, 269-285. mongardi s., correggiari a., trincardi f. (2004) terrazzi deposizionali sommersi al largo di capo suvero. in: chiocci f.l., d’angelo s., romagnoli c. (a cura di), atlante dei terrazzi deposizionali sommersi lungo le coste italiane. mem. descrittive della carta geologica d’italia, 58, 63-74. mougenot d., buillot g., rehault j.p. (1983) prograding shelf break types on passive margins: some european examples. in: stanley, d.j., moore, g.t. (eds.), the shelfbreak: critical interface on continental margins. sepm special publication, 33, 61-77. nicolich r. (1985) egt southern segment: reflection seismic in the offshore areas. in: galson da, mueller dw (eds.), second egt workshop: the southern segment. esf, strasbourg, 33-38. nummedal d., swift d.j.p. (1987) transgressive stratigraphy at sequence-bounding unconformities, some principles derived from holocene and cretaceous examples. in: nummedal d., hopilkey o., howard j.d. (eds.), sea level fluctuations and coastal evolution. sepm special publication, 41, 241-260. pepe f., sulli a., agate m., di maio d., kok a., lo iacono c., catalano r. (2003) plio-pleistocene geological evolution of the northern sicily continental margin (southern tyrrhenian sea): new insights from high resolution, multi-electrode sparker profiles. geo mar. lett., 23, 53-63. pepe f., sulli a., bertotti g., catalano r. (2005) structural highs formation and their relationships to sedimentary basins in the north sicily continental margin (southern tyrrhenian sea): implication for the drepano thrust front. tectonophysics, 409, 1-18. roveri m., correggiari a. (2004) terrazzi deposizionali sommersi nell’arcipelago toscano (margine orientale del canale di corsica). in: chiocci f.l., d’angelo s., romagnoli c. (a cura di), atlante dei terrazzi deposizionali sommersi lungo le coste italiane. mem. descrittive della carta geologica d’italia, 58, 11-26. ruggeri g. (1978) una trasgressione del pleistocene inf. nella sicilia occidentale. naturalista sicil., 2, 159-171. scarascia s., lozej a., cassinis r. (1994) crustal structures of the ligurian, tyrrhenian and ionian sea and adjacent onshores areas interpreted from wide-angle seismic profile. boll. geof. teor. appl., 36, 5-19. selli r. (1970) cenni morfologici generali sul mar tirreno. giornale di geologia, 37, 5-24. sulli a., lo presti v., gasparo morticelli m., antonioli f. sulli a. et al. 156 (2012) vertical movements in ne sicily and its offshore: outcome of tectonic uplift during the last 125 ky. quaternary international, 1-15. tesson m., posamentier h. w., gensous b. (2000) stratigraphic organization of late pleistocene deposits of the western part of the golfe du lion shelf (languedoc shelf), western mediterranean sea, using high-resolution seismic and core data. aapg bull., 84 (1), 119 -150. trincardi f., field m. e. (1991) geometry, lateral variation, and preservation of downlapping regressive shelf deposits: eastern tyrrhenian sea margin, italy. journ. sedim. petrol. 61 (5), 775 790. urgeles r., cattaneo a., puig p., liquete c., de mol b., ambla’s d., sultan n., trincardi f. (2011) a review of undulated sediment features on mediterranean prodeltas: distinguishing sediment transport structures from sediment deformation. mar. geophys. res., 32, 49-69 vail p.r. (1987) seismic stratigraphy interpretation procedure. in: bally, a.w. (ed.), atlas of seismic stratigraphy, vol. 27. american association of petroleum geologists studies in geology, 1-10. williams d.f., thunnel r.c., tappa e., rio d., raffi i., (1988) chronology of the pleistocene oxygen isotope record, 0-1,88 m.yr b. p. palaeogeogr., palaeoclimatol., palaeoecol., 61, 221-240. ms. received: june 15, 2012 final text received: september 7, 2012 << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /all /binding /left /calgrayprofile (gray gamma 2.2) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /warning /compatibilitylevel 1.4 /compressobjects /tags /compresspages true /convertimagestoindexed true /passthroughjpegimages true /createjobticket false /defaultrenderingintent /default /detectblends true /detectcurves 0.1000 /colorconversionstrategy /leavecolorunchanged /dothumbnails false /embedallfonts true /embedopentype 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documenti pdf creati possono essere aperti con acrobat e adobe reader 5.0 e versioni successive.) /enu (use these settings to create adobe pdf documents suitable for reliable viewing and printing of business documents. created pdf documents can be opened with acrobat and adobe reader 5.0 and later.) >> >> setdistillerparams << /hwresolution [1200 1200] /pagesize [396.850 566.929] >> setpagedevice imp.bonci& geositi e gssp le attività del dipartimento difesa della natura dell'apat luciano bonci, tiziana mezzetti & gabriella rago apat dipartimento difesa della natura servizio aree protette e pianificazione territoriale abstract: l. bonci, t. mezzetti & g. rago, geosites and gssp apat's activities. the italian agency for environmental protection (apat) is the italian body responsible for the protection of the environment and for the collection and management of environmental data, and develops an important activity on geosites. apat is setting up a working group within geological coordination committee between state, regions and autonomy provinces (comitato di coordinamento geologico tra lo stato, le regioni e le province autonome c.c.s.r.) to validate geosites and to insert it in the national geosites atlas, and a working group within italian commision on stratigraphy (commissione italiana di stratigrafia) to protect and to valorize the gssp. parole chiave: geositi, gssp, italia. keywords: geosites, gssp, italy. il quaternario italian journal of quaternary sciences 21(1a), 2008 75-80 premessa a seguito del ii° symposium internazionale sulla protezione del patrimonio geologico, tenutosi a roma nel 1996, si è costituito il gruppo progeo italia il cui compito principale è quello di promuovere la diffusione dell'informazione sul patrimonio geologico e la sua conservazione ed al quale hanno aderito docenti e ricercatori delle università, del cnr, dell'enea e del servizio geologico nazionale. in tale ambito è maturata l'idea di realizzare un censimento nazionale dei geositi ed i l servizio geologico nazionale, anche in conseguenza del ruolo storico istituzionale ricoperto, è stato indicato quale candidato ideale per il coordinamento delle diverse iniziative che in tale ambito, a livello locale, erano già state da tempo avviate in italia. il servizio geologico nazionale curava, infatti, a livello nazionale la raccolta, gestione e pubblicazione dei dati e della cartografia geologica e geotematica, compresa quella ufficiale dello stato, realizzata ai sensi della legge 68/1960, ponendosi in qualità di organo cartografico dello stato, quale struttura tecnico scientifica centrale e di coordinamento tra la comunità scientifica e le realtà istituzionali regionali e locali. l'apat l'8 ottobre 2002, in attuazione del dettato normativo contenuto nel d.p.r. 207 del 8.8.2002, diviene operativa l'apat, l'agenzia per la protezione dell'ambiente e per i servizi tecnici. a seguito dell' art.38 del d.l.vo 300 del 30.7.1999, l'apat eredita le competenze istituzionali dell'agenzia nazionale per la protezione dell'ambiente (anpa) e del dipartimento per i servizi tecnici nazionali ed in particolare del servizio geologico e del servizio idrografico e mareografico della presidenza del consiglio dei ministri (dstn), svolgendo i compiti e le attività tecnico-scientifiche di interesse nazionale per la protezione dell'ambiente, per la tutela delle risorse idriche e della difesa del suolo. nell'ambito di questo nuovo assetto organizzativo tutte le attribuzioni proprie del servizio geologico nazionale, sono confluite all'interno del dipartimento difesa del suolo ad eccezione del progetto “carta della natura” (legge 394/91) e del progetto “tutela del patrimonio geologico” attribuiti al dipartimento difesa della natura istituendo contemporaneamente il servizio carta della natura e all'interno dell'ex servizio “parchi e risorse naturali", ora servizio “aree protette e pianificazione territoriale“, il settore “tutela del patrimonio geologico”. con questa nuova assegnazione di competenze la tutela del patrimonio geologico viene più strettamente correlata alla tutela degli altri aspetti del patrimonio naturalistico ed ambientale di cui la geologia è substrato fisico e aspetto morfologicopaesistico permanente. i geositi ed il contesto normativo “i geositi sono aree del territorio di rilevante interesse geo-morfologico e valore naturalistico, risorse non rinnovabili, ed importanti testimoni della storia della terra (w.a. wimbledon, 1995). essi rendono “peculiari” i luoghi e le aree territoriali in cui sono inseriti per i loro specifici fattori fisici, morfologici, climatici e strutturali, e necessitano pertanto di un'azione di tutela e valorizzazione affinché non vada persa per sempre traccia della storia della terra. dal punto di vista normativo il valore del patrimonio geologico culturale è stato riconosciuto sia a livello nazionale che internazionale: 76 l. bonci et al. dalla convenzione per la protezione del patrimonio mondiale, culturale e naturale adottata dall' unesco nell'ambito della conferenza generale svoltasi a parigi il 16 novembre 1972 e recepita dal nostro ordinamento con la legge 6 aprile 1977, n.184, il cui scopo è conservare il patrimonio mondiale di interesse universale eccezionale, attraverso la stesura di una lista di siti culturali e naturali (world heritage list), in particolare l'art.2 che individua nell'ambito del patrimonio naturale “i monumenti naturali costituiti da formazioni fisiche e biologiche o da gruppi di tali formazioni di valore universale eccezionale dall'aspetto estetico o scientifico, le formazioni geologiche e fisiografiche e le zone strettamente delimitate costituenti l'habitat di specie animali e vegetali minacciate, di valore universale eccezionale dall'aspetto scientifico o conservativo, i siti naturali o le zone naturali strettamente delimitate di valore universale eccezionale dall'aspetto scientifico, conservativo o estetico naturale […]”. il concetto di patrimonio geologico viene dunque a far parte del patrimonio naturale e definito in base a quanto stabilito dal documento risultante dal i° simposio internazionale per la protezione del patrimonio geologico tenutosi a digne nel 1991: “dichiarazione internazionale dei diritti della memoria della terra” come l'insieme delle risorse non rinnovabili, di valore scientifico, culturale o educativo, quali formazioni o strutture geologiche, forme del paesaggio o giacimenti paleontologici e mineralogici che permettono di riconoscere, studiare ed interpretare l'evoluzione della storia geologica della terra ed i processi che l'hanno interessata; dalla direttiva habitat del 21 maggio 1992 n. 92/43/cee relativa alla conservazione degli habitat naturali e seminaturali e della flora e della fauna selvatiche, che integra la legislazione comunitaria sulla conservazione della natura, proteggendo in un quadro unitario habitat naturali (zone terrestri o acquatiche che si distinguono per le loro caratteristiche geografiche, abiotiche e biotiche interamente naturali e seminaturali). in particolare nell'allegato i alla direttiva vengono individuati tra i vari tipi di habitat naturali di interesse comunitario “dune marittime e interne, torbiere e paludi, habitat rocciosi (grotte marine sommerse e semisommerse, campi di lava e cavità naturali, ghiacciai permanenti), ghiaioni, zone rilevanti per avere delle caratteristiche biogeografiche e geologiche particolari o uniche”; dalla convenzione europea del paesaggio firmata a firenze il 20 ottobre del 2000, ratificata e resa esecutiva in italia con la legge 9 gennaio 2006 n.14, relativa alla salvaguardia, gestione e pianificazione dei paesaggi europei, in particolare il cap.ii, art.1 lett. a, d) volto alla salvaguardia dei “paesaggi ed alle azioni di conservazione e di mantenimento degli aspetti significativi o caratteristici di un paesaggio giustificate dal suo valore di patrimonio derivante dalla sua configurazione naturale e/o dal tipo di intervento umano; l'art.5, lett.a) in cui il paesaggio viene ad assumere un ruolo fondamentale nel consolidamento dell'identità europea in quanto “componente essenziale del contesto di vita delle popolazioni, espressione della diversità del loro comune patrimonio culturale e naturale[…]”. dalla raccomandazione rec(2004)3, documento sulla conservazione del patrimonio geologico e delle aree di speciale interesse geologico adottato dal comitato dei ministri del consiglio d'europa. dall'art. 9 della costituzione della repubblica italiana riguardante la promozione e lo sviluppo della cultura e la ricerca scientifica e tecnica, e la tutela del paesaggio e del patrimonio storico e artistico della nazione; dalla legge quadro sulle aree protette l.394/1991 in particolare l'art.1 comma 2), che indica tra le finalità del regime di tutela e di gestione delle aree protette, quella della conservazione e tutela delle “formazioni fisiche, geologiche, geomorfologiche e biologiche, o gruppi di esse che abbiano rilevante valore naturalistico e ambientale”; l'art.1 comma 3 lett. a) che sottopone a regime di tutela allo scopo di evidenziarne i valori naturali e i profili di vulnerabilità territoriale le “singolarità geologiche, formazioni paleontologiche, valori scenici e panoramici, processi naturali, equilibri idraulici ed idrogeologici; dal codice dei beni culturali e del paesaggio d. lvo. 42/2004, in particolare l'art. 2 che definisce il patrimonio culturale “costituito dai beni culturale e dai beni paesaggistici […] sono beni paesaggistici gli immobili e le aree […] costituenti espressione dei valori storici, culturali, naturali, morfologici ed estetici del territorio”, l'art. 10 che identifica tra i beni culturali “le cose immobili e mobili […] che interessano la paleontologia, i siti minerari di interesse storico o etnoantropologico”, l'art. 136 che elenca tra gli immobili di notevole interesse pubblico le cose immobili che hanno cospicui caratteri di bellezza naturale o di singolarità geologica; tale elenco non ha carattere di esaustività ma vuole dare un quadro sintetico delle principali normative per la tutela del patrimonio geologico. le attività svolte e il “censimento nazionale dei geositi” l'idea di realizzare un censimento nazionale dei geositi prende corpo nell'anno 2000 attraverso l'attivazione del progetto “conservazione del patrimonio geologico italiano". il progetto diviene operativo grazie a numerosi accordi di collaborazione e convenzioni con istituti scientifici ed università tra cui (nel 2002 e 2003) quelle con i l dipartimento polis centro di documentazione geositi dell'università degli studi di genova volte alla “costituzione di un inventario dei geositi italiani finalizzato alla realizzazione di una banca dati nazionale sul patrimonio geologico italiano” allo scopo di costituire un centro nazionale di raccolta sistematica di dati e metadati sui siti di interesse geologico e di fornire uno strumento per la pubblica amministrazione nella pianificazione territoriale (d'andrea, 2000; d'andrea & angelelli, 2001). le convenzioni hanno portato ad un prima individuazione e localizzazione dei geositi sull'intero territorio nazionale, ed alla realizzazione di una “carta di prima attenzione dei siti di interesse geologico in italia” presentata in occasione del 32° international geological congress (firenze 2004). nel 2005 viene pubblicato un rapporto tecnico apat, frutto della cooperazione di alcuni fra i più rappresentativi attori delle pubbliche amministrazioni, delle università e dei centri di ricerca nelle iniziative di conservazione e valorizzazione del patrimonio geologico, dal titolo “patrimonio geologico e geodiversità, esperienze ed attività dal servizio geologico d'italia all'apat ”, scaricabile dal sito apat all'indirizzo: http://www.apat.gov.it/site/itit/apat/ pubb l i caz ion i /rappo r t i /documen to / rappo r t i _2005_51.html. lo studio sul territorio nazionale dei geositi è stato messo in relazione con il sistema di aree naturali protette (l.394/1991). dalla sovrapposizione del livello dei geositi su quello delle aree naturali protette, presenti nel sistema informativo territoriale “gis natura” del mattm, si evince una forte concentrazione dei siti geologici sul territorio al di fuori del perimetro delle aree suddette. al fine quindi di conservare e valorizzare il patrimonio geologico su tutto il territorio nazionale, occorre far rientrare i geositi nella pianificazione territoriale. in vista di ciò, nell'ambito di una collaborazione con il ministero per i beni e le attività culturali (mibac), sono state fornite le informazioni contenute nella banca dati, per l'inserimento dei geositi nella pianificazione urbanistica, considerato che entro il 2008 tutte le regioni che hanno redatto il piano paesaggistico dovranno procedere ai necessari adeguamenti così come previsto dall'art.156 del dlgs. 42/2004. verso il repertorio nazionale dei geositi l'istituzione di un “repertorio nazionale dei geositi” che selezioni i siti di maggiore interesse geologico, è un passo necessario per le successive azioni di tutela e conservazione nella pianificazione del territorio. il censimento dei geositi è un mezzo, uno strumento per approdare al repertorio nazionale dei geositi. il primo è un raccolta di dati e informazioni, il secondo è un atlante all'interno del quale rientreranno solo i geositi certificati da una commissione creata ad hoc. attualmente il censimento nazionale dei geositi conta circa 3700 segnalazioni, molte regioni ed enti locali hanno posto in essere diverse azioni, ognuna adottando dei propri criteri di valutazione e gerarchizzazione, per la realizzazione di censimenti dei siti di interesse geologico che dovranno confluire all'interno del censimento nazionale gestito dall'apat. l'istituzione di un “repertorio nazionale dei geositi” che selezioni secondo criteri condivisi a livello nazionale, i siti di maggiore interesse geologico, è un passo necessario per le successive azioni di tutela e conservazione nella pianificazione del territorio. per questo, d'intesa con i l comitato di coordinamento geologico tra lo stato, le regioni e le province autonome (c.c.s.r.), è stato deciso di costituire un gruppo di lavoro che per la valutazione-validazione dei geositi di interesse nazionale presenti in banca dati apat. le segnalazioni dei geositi, prodotte dai servizi geologici regionali, dalle agenzie per la protezione dell'ambiente delle regioni e delle province autonome, dalle università e dagli enti di ricerca, raccolte e catalogate dalla segreteria tecnica del settore tutela del patrimonio geologico dell'apat, verranno trasmesse al comitato di coordinamento geologico tra lo stato, le 77geositi e gssp le attività del dipartimento ... regioni e le province autonome (c.c.s.r.) per la convalida ed il successivo inserimento nel repertorio nazionale dei geositi. il complesso delle attività si articola nelle seguenti fasi: la distribuzione della scheda di censimento1 disponibile su supporto cartaceo e informatico la ricognizione dei dati sul campo, e compilazione della scheda di censimento da parte dei rilevatori; la verifica delle informazioni contenute nella scheda (georeferenziazione su cartografia, bibliografia...) l'archiviazione e l'organizzazione dei dati in un db nazionale; la gestione e l'aggiornamento dei dati inerenti i geositi e loro restituzione su report e cartografia; la valutazione-validazione dei siti segnalati attraverso il gdl all'interno del ccsr il repertorio nazionale dei geositi i global boundary stratigraphic section and point (gssp) grazie inoltre agli accordi di collaborazione con la commissione italiana di stratigrafia della società geologica, con la società paleontologica e con il museo di storia naturale di firenze si sono intessute le basi per l'inserimento nella banca dati dei global stratotype (gssp) e siti di interesse paleontologico e mineralogico. i global boundary stratigraphic section and point (gssp) sono località mondiali in cui sono registrate il maggior numero di informazioni fisiche, chimiche e paleontologiche su un limite tra due ere geologiche e dove tale limite sia fisicamente presente nella letteratura scientifica italiana i gssp sono definiti da due termini, il primo, stratotipo, indica la successione litologica che caratterizza l'intervallo geologico che contiene il limite tra due ere; il secondo, chiodo d'oro, rappresenta invece il limite fisico tra due ere ed è il piano tra due strati che mette in contatto rocce di un'età con rocce dell'altra età. le località che vengono definite gssp, sono il punto di riferimento mondiale e devono essere prese in considerazione in qualsiasi caso si renda necessario valutare se una determinata roccia appartiene a un determinato intervallo geologico. i gssp, selezionati da una commissione internazionale, la “international union of geology sciences”, devono soddisfare requisiti di accessibilità e fruibilità, ed essere correlabili stratigraficamente con altre località nel mondo. tali gssp non sono eterni e possono essere rimpiazzati in qualsiasi momento da una successione geologica più completa presente in un'altra parte del mondo.lo stato di conservazione pertanto è fondamentale e legato alla valorizzazione e fruibilità del bene. 1la scheda di censimento è scaricabile in formato pdf sul sito apat all'indirizzo: h t t p : / / w w w . a p a t . g o v . i t / s i t e / i t t/progetti/il_censimento_nazionale_dei_geositi/ ad oggi, nella banca dati apat, sono presenti sei dei sette gssp italiani ufficialmente approvati da iugs di cui di seguito si riporta un elenco sintetico: regione piemonte: sezione di lemme carrosio (alessandria) stratotipo del limite oligomiocene età: 23.8 ma approvato da iugs: anno 1996; regione marche: sezione di massignano (ancona) stratotipo del limite eocene-oligocene età: circa 34 ma approvato da iugs: anno 1992; regione marche monte dei corvi (ancona) base tortoniano approvato da iugs: anno 2003; regione calabria sezione la vrica (crotone) limite plio-pleistocene (fra terziario e quaternario) approvato da iugs: anno 1985; regione sicilia sezione di monte san nicola (caltanissetta) stratotipo del limite piacenzianogelasiano (pliocene medio-superiore) età: circa 2.6 ma approvato da iugs: anno 1996; regione sicilia sezione di capo rossello-punta piccola (ag). stratotipo del limite zancleanopiacenziano (pliocene inferiore-pliocene medio) età: circa 3.6 ma approvato da iugs: anno 1997; ed uno di quelli in corso di formalizzazione. regione marche sezione di gorgo a cerbara (pesaro urbino) stratotipo del limite aptiano-albiano in corso di formalizzazione da iugs. 78 fig. 1 le fasi operative del progetto “il censimento nazionale dei geositi”. “the national geosites' census”: the phases. fig.2 carta di prima attenzione dei geositi e gssp segnalati. geosites and gssp cartography l. bonci et al. le azioni di tutela, valorizzazione e fruizione la conservazione e la tutela dei geositi può avvenire soltanto attraverso un documentato ed impegnativo lavoro collegiale di individuazione, catalogazione, valutazione e divulgazione dei risultati. le azioni da intraprendere per la tutela dei geositi che saranno validati e dunque inseriti nel repertorio nazionale, dovranno essere mirate a sensibilizzare gli amministratori degli enti regionali, provinciali e comunali, affinché possano intraprendere le opportune iniziative di tutela e valorizzazione dei siti di interesse geologico. a tal fine il servizio ha programmato una serie di attività quali: la pubblicazione sul sito web apat del repertorio nazionale dei geositi; l'attivazione, presso apat di un tavolo di lavoro con la partecipazione dei rappresentanti dei servizi geologici regionali e dei rispettivi referenti scientifici in cui poter confrontare le criticità e le problematiche relative ai geositi ed alla loro valutazione e gerarchizzazione; per i gssp, la cui rilevanza scientifica è già stata riconosciuta a livello internazionale dalla international union of geological sciences, si condivide la proposta della commissione italiana di stratigrafia per la costituzione di uno specifico gruppo di lavoro coordinato da apat, con la partecipazione dei referenti scientifici per ciascun gssp, avente l'obiettivo di predisporre specifici progetti per la valorizzazione, protezione e fruizione. infine, tra le iniziative intraprese per l'anno internazionale del pianeta terra, apat, insieme ad altre 53 organizzazioni nazionali e internazionali di 43 paesi, partecipa al progetto onegeology il cui obiettivo è quello di rendere pubblici e accessibili via internet i migliori dati di cartografia geologica disponibili a livello mondiale (scala 1:1.000.000), attraverso la conversione delle informazioni in una nuova lingua geologica universale (geosciml). nell'ambito di questo progetto si è deciso di rendere disponibile come strato informativo di interesse geo-turistico, collegabile quindi alle altre informazione geologiche, i dati presenti nel repertorio, rendendoli accessibili a più utenti al fine di favorirne così una più ampia diffusione. bibliografia generale cowie j. w. et alii (1986) guidelines and statutes of the international commission on strtigraphy (ics), cour. forsch. inst. senckenberg, 83, pp. 1-14 d'andrea m. (2000) servizio geologico nazionale: progetto “conservazione del patrimonio geologico ital iano”. nota informativa. giornale di geologia, se 3, 62, suppl., pp. 121-124. d'andrea m., angelelli f. (2001) progetto “conservazione del patrimonio geologico italiano. invito alla paleontologia, paleoitalia, 5, pp. 9-15. d'andrea m., lisi a., mezzetti t. (2005) patrimonio geologico e geodiversità, esperienze ed attività dal servizio geologico d'italia all'apat, apat, rapporti 51/2005, pp. 59-63 remane et alii (1996) revised guidelines for the establishment of global chronostratigraphic standards by the international commission on stratigraphy: episodes, 19, pp. 77-81. siti internet ∗ http://www.apat.gov.it/site/it-it/ ∗ http://www.deaprofessionale.it. ∗ http://www.onegeology.org/ 79 ms. ricevuto il 2 aprile 2008 testo definitivo ricevuto il 17 aprile 2008 ms. received: april 2, 2008 final text received: april 17, 2008 geositi e gssp le attività del dipartimento ... available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 34 (1), 2021, 69-74 new data on the middle pleistocene small mammal fauna from the homo bearing site of fontana ranuccio (anagni basin, central italy). fabio bona 1, flavia strani 2,3 1 museo civico dei fossili di besano, besano, varese, italia. 2 dipartimento di scienze della terra, sapienza università di roma, roma, italia. 3 istituto italiano di paleontologia umana, roma, italia. corresponding author: fabio bona <fabgeo@libero.it> abstract: the scanty small mammals material of the middle pleistocene fontana ranuccio site is characterized by the presence of six species belonging to three order: eulipotyphla, lagomorpha, and rodentia. the small mammal fossils evidence from fontana ranuccio, instead the scarce number of specimens, indicates that the site is characterized by a warm and wooded environment with subordinate grassland. keywords: systematics, chronological remarks, environmental. 1. introduction the aim of this short note is to describe for the first time the remains of small mammals, albeit limited to a few often poorly preserved fragments, from the middle pleistocene homo bearing site of fontana ranuccio (anagni, central italy). the fontana ranuccio site is located in the anagni basin about 90 km southeast of rome (fig. 1). the locality was discovered in 1976 during quarry activities for the extraction of “pozzolana” (volcanic ash). since then, several excavation campaigns have been carried out by the italian institute of human paleontology which have allowed to unearth a large number of archaeological tools (>100), faunal remains (>25,000) and four human teeth (segre & ascenzi, 1984; ascenzi et al., 1993; segre naldini et al., 2009; rubini et al., 2014; grimaldi et al., 2020). the fossiliferous layer is located within a succession of pyroclastic deposits which has been dated around 0.4 ma (pereira et al., 2018), right after the mis 12-11 passage which marks the end of the early-middle pleistocene transition with the definitive consolidation of the glacial cycles’ periodicity change from 41 kyr to 100 kyr (the socalled “mid-brunhes event”; head & gibbard, 2015). after this event an increase in the amplitude of both glacial and interglacial periods is observed with the mis 11 representing one of the longest and warmest interglacial recorded after the early-middle pleistocene transition (weirauch et al., 2008). the fontana ranuccio rich vertebrate collection is stored at the italian institute of human palaeontology (isipu) depository (anagni, frosinone). among the large mammals, 1360 specimens have been attributed to 15 taxa: palaeoloxodon antiquus, stephanorhinus sp., equus cf. e. mosbachensis, hippopotamus amphibius, dama clactoniana, cervus elaphus eostephanoceros, praemegaceros sp., bos primigenius, sus scrofa ferus, ursus deningeri, ursus sp., panthera sp., crocuta crocuta, canis mosbachensis, macaca sylvanus and homo sp. (segre & ascenzi, 1984; ascenzi et al., 1993; rubini et al., 2014: conti et al., 2021). artiodactyla is the best-represented order (68% of faunal remains) of which 69% belong to cervids and 25% to bovids (strani et al., 2018). fig. 1 geographical position of fontana ranuccio (modified from strani et al., 2018). https://doi.org/10.26382/amq.2021.01 70 bona f., strani f. 2. materials and methods the studied material was collected during past field excavations starting from 1976 to today (tab.1). the measurements of long bones and skulls presented in this paper were taken according to von den driesch (1976). the measurements of the lower first molar of microtus (terricola) sp. were taken, using a digital micrometer parker hannifin-decadal, according to sala et al. (1994). the length of the tooth row were taken on the buccal side from the first root of the p4 to the last of the m3. the fossils were compared, where necessary, with the comparison collection of one of the authors (fb). 3. systematic the scanty small mammals material of the middle pleistocene fontana ranuccio site is characterized by the presence of six species belonging to three orders: eulipotyphla, lagomorpha and rodentia. the rodents are represented by seven specimens, only four of those are determined at least to the generic level. the eulipotyphla are represented by two remains attributed one to a talpid and the second to a hedgehog. three specimens are referred to a leporid. order rodentia bowdich, 1821 family cricetidae fischer, 1817 genus microtus schrank, 1798 microtus (terricola) sp. material: 1 left hemi-mandible with m1 and m2 (fr sd-171) (fig. 1,2). measure: tab. 2. the m1 of fr sd-171 shows a posterior loop, t1, t2 and t3 alternate, t4 and t5 are extremely confluent, forming a “pitymyoid” rhombus useful to attribute the specimen to subgenus terricola, and t6 and t7 are confluent with ac3. bsa3 and lsa4 are aligned similar in shape to the extant m. (t.) gr. multiplex-subterraneus. bra4 and lra5 are well developed. the tooth axis is rectilinear with a slight concavity to the buccal side. the tooth enamel shows a positive thickness (microtus-type) differentiation. the lingual triangles are larger than the buccal ones. the cement is present in the re-entrant angles. the current taxonomic situation of the vole of the subgenus terricola of the so-called "savii" group of central-south italy, in accordance with genetic data, sees the attestation of different species of the classic italian endemic savi’s pine vole (microtus (t.) savii) as described by toschi (1965). specifically, the species microtus (t.) brachycercus is the most typical of southern italy. microtus (t.) brachycercus was primarily defined at the genetic level and secondarily for some morphological characteristics defined as a member of the “mediterranean” group; in fact, it is probably related, for the morphometric analysis of m1, to species like microtus (t.) duodecimcostatus and microtus (t.) lusitanicus of the iberian peninsula (contoli et al., 2008). according to data on extant savi’s pine vole group, which underline the great level of variation in the italian peninsula, is not possible with only one specimen to attribute fr sd-171 to a specific level. family gliridae muirhead in brewster, 1819 genus eliomys wagner, 1840 eliomys sp. material: 1 second left hemi-mandible (fr sd-172) without teeth. measure: length of the tooth row p4-m3: 6 mm. according to the shape of the radical surface (niethammer & krapp, 1978), reflecting the presence of the roots of the fourth premolar and of the three molars, and to the dimensions (fig. 2, 3) fr sd-172 is attributed to eliomys sp. the complete radical surface of fr sd-172 measured 6 mm, it is smaller than genus sciurus, that usually reached 9-11 mm (toschi, 1965) and larger for the genus dryomys, that usually reached 3-4 mm (toschi, 1965). tab. 1 commented list of the collected small mammals. tab. 2 measures of first lower molar of fr sd-171 (measures in mm). 71 genus glis brisson, 1762 cf. glis sp. material: 1 left incomplete femur (fr sd-177/1). the direct comparison of fr sd-177/1 with specimens of the comparative collection allows to tentatively attribute the fossil to cf. glis sp. order lagomorpha brandt, 1855 family leporidae fischer de waldheim, 1817 genus lepus linnaeus, 1758 lepus sp. material: 1 upper left fourth premolar or first/second molar (fr sd-173); 1 distal fragment of left humerus (fr sd-163); 1 right distal fragment of tibia (inv. 56572). measure: fr sd-173, bd (breadth of distal end): 11.8 mm; inv. 56572, bd (breadth of distal end): 14.1 mm. fr sd-173 is characterized by a not deep coronoid fossa and a wide supratrochlear hole and by a deep trochlea and small humeral capital (fig. 3a). inv. 56572, although a small fragment, presents a sub-rectangular distal articular surface and a well-developed malleulus lateralis (fig. 3b). the three lagomorph specimens, according to the dimensions (larger than the genus oryctolagus where, for example, specimens from sicily humerus bd does not reach 10 mm and tibia bd does not reach 12 mm, fig. 3ab) are attributed to lepus sp. (ascenzi et al., 1993). order eulipotyphla waddell et al., 1999 family talpidae fischer de waldheim, 1817 genus talpa linnaeus, 1758 talpa sp. material: 1 incomplete left humerus (fr 86-1). measure: fr 86-1, sd (smallest breadth of diaphysis): 4.4 mm. the morphology permit, without doubts, to attribute fr 86-1 to talpa sp. (fig. 2a-b); the large dimensions (fig. 4b) and the poorly preservation of the humerus does not permit to a clear attribution to one of the two large species of the genus talpa nowadays present in the area of fontana ranuccio: talpa europaea and talpa romana. family erinaceidae fischer de waldheim, 1817 genus erinaceus linnaeus, 1758 erinaceus sp. material: 1 proximal fragment left scapula (fr 78-3). measure: fr 78-3, glp (greatest length of the processus articularis): 10.7 mm. the fragment fr 78-3 has been determined on a comparative base to erinaceus europaeus (fig. 4a). 4. chronological considerations the association of the large mammals and the geochemical dates testified an age for fontana ranuccio site of about 400.000 (middle galerian) (pereira et al., 2018). the presence in the scanty small mammal fauna of an evolved form of microtus vole indicates that the deposit’s age is near to the early toringian (sala & masini, 2007) confirming the data for the large mammal fauna (sala & masini, 2007). 5. paleoecological inferences the small mammal fossils from fontana ranuccio, despite the scarce number of specimens (two glirids, a pine vole, a hare, a large mole and a large hedgehog), allow to make some considerations on paleoenvironmen fontana ranuccio small mammal fauna fig. 2 fontana ranuccio small mammals. 1: fr sd-171 microtus (terricola) sp., left m/1-2 (hemi-mandible); 2: fr 86-1 talpa sp., left humerus (a: dorsal, b: ventral); 3: fr sd-172 elyomys sp., left hemi-mandible. scale bars = 1mm. 72 bona f., strani f. fig. 3 fontana ranuccio lagomorphs. a, left humerus, a1: oryctolagus cuniculus, modern; a2: fr sd-163; a3: lepus europaeus, modern. b, right tibia, b1: oryctolagus cuniculus, modern; b2: inv. 56572; b3: lepus europaeus, modern. scale bars =1mm. 73 fontana ranuccio small mammal fauna fig. 4 fontana ranuccio small mammals. a left scapula, a1: erinaceus europaeus, modern; a2: fr 78-3, erinaceus sp., left scapula fragment. b left humerus, b1: talpa caeca, modern; b2: fr sd-1; b3: talpa europaea, modern. scale bars =1mm. tal conditions of the area during the deposition of fossil beds. the presence of glirids, arvicolids of the subgenus terricola and large talpids allows to interpreted as the site was characterized by the presence of warm and wooded environment with subordinate grassland and welldeveloped soils; the presence of beavers (ascenzi et al. 1993) allow to think about the presence of water stream. this is in accordance with what has been reported by palaeoecological and paleoenvironmental reconstruction based on herbivorous ungulates dietary adaptations, where most cervids (the best represented mammal group) display dental wear patterns compatible with a diet based on the consumption of soft plant resources (e.g., leaves and twigs) which are most common in wooded areas and closed canopies (strani et al., 2018). the abundance of wooded areas is also supported by results obtained by the stable isotopic analysis on e. cf. e. mosbachensis dental material, which suggests that this equid while feeding mostly on abrasive plants occupied less open habitats (e.g. at the edge between grasslands and woodlands) (strani et al., 2019). acknowledgements we thank all the palaeontologists and archaeologists that participated in the excavations and lab activities of fontana ranuccio. we are particularly grateful to luciano bruni of the italian intistute of human paleontology (isipu) for providing us endless support to our research work. we also acknowledge dr. juan manuel lópezgarcía and the anonymous reviewer for the helpful comments that allowed us to improve the manuscript. references ascenzi a., biddittu i., cassoli p.f., segre a.g., segre naldini e. (1993) dal paleolitico inferiore al bronzo nel bacino di anagni. in: gatti s. (ed.), dives anagnia dalla preistoria alla protostoria. archeologia della valle del sacco. l'erma di bretschneider, 25-47. conti j., bellucci l., iurino d.a., strani f., sardella r. (2021) first occurrence of the brown bear in the italian peninsula: evidence from the archaeopalaeontological site of fontana ranuccio (middle pleistocene; central italy). alpine and mediterranean quaternary, 34(1), 55-68. contoli l., nappi a., castiglia r. (2008) caratteri generali dei microtus (terricola) del “gruppo savii”. in: amori g., contoli l., nappi a. (eds.). calderini editore, bologna, 525-535. head m., gibbard p. (2015) early-middle pleistocene transitions: linking terrestrial and marine realms. quaternary international, 389, 7-46. grimaldi s., santaniello f., angelucci d.e., bruni l., parenti f. (2020) a techno-functional interpretation of the lithic assemblage fron fontana ranuccio (anagni, central italy): an insight into a mis 11 human behaviour. journal of paleolithic archaeology, 3, 944-966. 74 bona f., strani f. niethammer j., krapp f. (1978) rodentia 1 (sciuridae, castoridae, gliridae, muridae). handbuch der säugetiere europas, 1. akademische verlagsgesellschaft, wiesbaden, pp. 476. pereira a., nomade s., moncel m., voinchet p., bahain j., biddittu i., falguères c., giaccio b., manzi g., parenti f., scardia g., scao v., sottili g., vietti a. (2018) integrated geochronology of acheulian sites from the southern latium (central italy): insights on human-environment interaction and the technological innovations during the mis 11-mis 10 period. quaternary science reviews, 187, 112-129. rubini m., cerroni v., festa g., sardella r., zaio p. (2014) a revision of hominin fossil teeth from fontana ranuccio (middle pleistocene, anagni, frosinone, italy). journal of human evolution, 77, 204216. sala b., masini f. (2007) late pliocene and pleistocene small mammal chronology in the italian peninsula. quaternary international, 160 (1), 4-16. sala b., masini f., torre d. (1994) villanyian arvicolids from rivoli veronese, a karst fissure in the adige valley, northeastern italy. bollettino della società paleontologica italiana, 33 (1), 3-11. segre a.g., ascenzi a. (1984) fontana ranuccio: italy's earliest middle pleistocene hominid site. current anthropology, 25 (2), 230-233. segre naldini e., muttoni g., parenti f., scardia g., segre a.g. (2009) nouvelles recherches dans le bassin plio-pléistocène d’anagni (latium méridional, italie). l’anthroplogie, 113, 66-77. strani f., demiguel d., bona f., sardella r., biddittu i., bruni l., de castro a., guadagnoli f., bellucci l. (2018) ungulate dietary adaptations and palaeoecology of the middle pleistocene site of fontana ranuccio (anagni, central italy). palaeogeography, palaeoclimatology, palaeoecology, 496, 238-247. strani f., pushkina d., bocherens h., bellucci l., sardella r., demiguel d. (2019) dietary adaptations of early and middle pleistocene equids from the anagni basin (frosinone, central italy). frontiers in ecology and evolution, 7, 176. toschi a. (1965) mammalia: lagomorpha, rodentia, carnivora, ungulata, cetacea. fauna d’italia vol. vii. calderini ed., bologna, pp. 442. von den driesch a. (1976) a guide to the measurement of animal bones from archaeological sites. cambridge press, harvard university, uk, pp. 136. weirauch d., billups k., martin p. (2008) evolution of millennial-scale climate variability during the midpleistocene. paleoceanography, 23. ms. received: november 13, 2020 revised: december 17, 2020 accepted: december 21, 2020 avaiable online: february 24, 2021 amq108 palombozedda.pub new evidence for the presence of endemic elephants from the late pleistocene of alghero (nortwestern sardinia, italy). maria rita palombo 1, marco zedda 2 1 cnr-igag, c/o department of earth sciences, university of rome sapienza, roma, italy. 2 department of veterinary medicine, university of sassari, sassari, italy. corresponding author: m.r. palombo <mariarita.palombo46@gmail.com> abstract: this short note aims to give notice of the vestige (the external imprint and few minute fragments) of the distal portion of an elephant tusk found in a sandstone deposit exposed at a small sheltered bay, las tronas bay, located at the north side of the el tro' carlos v bay (alghero, nw sardinia). the coarse sandstone and the overlain aeolian sediments deposited during the end of mis 5, confirming the presence of elephant populations in the alghero area at least since 100 ka bp (mis 5c). although the schreger lines are not detectable in the dentine fragments, the dimensions and the curvature of the external imprint enable us to hypothesize that the tusk could belong to the dwarf mammoth, mammuthus lamarmorai, already recorded in late pleistocene deposits of the same area (tramariglio and the coast south of alghero). keywords: mammuthus, tusk imprint, insularity, mis 5c.   available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 33 (1), 2020, 107-114 1. introduction the quaternary deposits exposed along the rocky cliff bounding the alghero coast and its bays (nw sardinia), are well known in the palaeontological literature due to the richness of vertebrate remains preserved in aeolian deposits, bone breccias mainly filling tectonic fissures of the triassic carbonate cliff, and fossiliferous layers of grottos and caves, such as those opening in the high cliff of capo caccia promontory (e.g. malatesta, 1954, 1977; malatesta & settepassi, 1954; comaschi caria, 1956, 1968; gliozzi, 1985; palombo & ibba, 2008; palombo et al., 2017a, b and references therein). the best-preserved pleistocene sediments extend quasi -continuously more than 5 km along the coast south of the alghero town. the quaternary deposits of alghero area have been widely studied and luminescence (quarz optically stimulated luminescence, osl, and k-feldspar pirir290) chronologically constrained. the sedimentary successions mainly consist of shallow-marine to coastal aeolian and alluvial sediments deposited during major climatic changes and sea-level variations related to alternating latest middle and late pleistocene stadial/ glacial and interstadial/interglacial cycles, from mis 6 to mis 3 (150 to 40 ka) (andreucci et al., 2010; pascucci et al., 2014). the geological and stratigraphical researches developed in the last decade permitted a detailed reconstruction of the palaeoenvironmental evolution of the area during the late pleistocene (andreucci et al., 2010, 2011, 2017; sechi et al., 2013, 2020; pascucci et al., 2014; casini et al., 2020). this note aims to give notice of a distal large fragment of an elephant tusk recently noticed in a deposit exposed at a small sheltered bay (las tronas bay hereinafter), located at the north side of the main el tro' carlos v bay, both not far from the centre of the alghero town, cliff-bounded by triassic limestones and late pleistocene sandstones (fig. 1). 2. the tusk imprint and its stratigraphical context the imprint of a fragment 48 cm-long of an elephant tusk was discovered in the natural section of a sandstone layer, cropping for about 20 cm above the present sea level, close to the shore and the high tide line (fig. 2 a.2, b). along the shoreline some scattered outcrops are preserved, locally capped by an aeolian deposit. two incomplete antlers of deer (likely praemegaceros cazioti) have been detected nearly at the top of such aeolian layers (fig. 2 a.1). the presence of the tusk imprint, already noted by some people but regarded as unimportant, was recognized in february 2020 by one of us (mz), who immediately informed the local archaeological superintendence of sardinia. the elephant and deer fossil remains (tusk and antlers) are still in place because the emergence status created by the covid-19 pandemic disease prevents the recovering activity scheduled by a team of the superintendence. an exhaustive description of the deer antlers https://doi.org/10.26382/amq.2020.10 108 palombo m.r., zedda m. in the frame of the fossil record of sardinian deer and some notes on the palaeogeographical and palaeoenvironmental evolution of the alghero area will be provided elsewhere (palombo et al., in prep). 2.1. the stratigraphical context quaternary shallow-marine to coastal sediments, aeolian and alluvial deposits are discontinuously present along the coast north of alghero, locally preserved and well exposed along the coast south of alghero, and some are exposed in the embayments of the town coast. along the southern alghero coast, the oldest pleistocene deposits, high angle planar cross-bedded coastal dunes, are luminescence dated at about 275 ka (mis 8), while a couple of discontinuous conglomerate deposits, marking the transition from mis 7 to mis 6, outcrops in the northern le bombarde beach (casini et al., 2020). the tusk imprint is embedded in one of the quaternary deposits exposed here and there in the small to wide bays located along the city coast, which mainly date to the late pleistocene (mis 5-mis 3) and are locally caped by holocene deposits (e.g. sechi et al., 2013; pascucci et al., 2014). the small outcropping to which the fossiliferous sandstone layer belongs is exposed in the northernmost part of las tronas bay, nearly to the shore (figs. 1-2.) the fossiliferous layer consists of about 40 cm of medium to coarse well-sorted planar low angle cross-stratified sandstone (fig. 3). on the beach, the surface of the sandstone layer is subfig. 1 the alghero area (sardinia, italy) in the mediterranean sea with the location of the localities mentioned in text. 1, las tronas bay; 2, el trò bay. bar scale 200 m. 109 a new elephant remain in the late pleistocene of nw sardinia planar, highly eroded by the wave action. it constitutes the bottom of some scattered outcrops preserved along the shoreline, mainly represented by medium to coarse sandy sediments, passing to 3.5 m-thick medium to coarse grained, high angle cross stratified and wellcemented sandstone deposits that have been interpreted as beach backshore passing to well developed coastal dunes (figs. 2, 3). the environmental context of this small bay sector corresponds to an incipient relict pocket beach characterized by a fairly sandy-gravelly foreshore, passing to a well-developed sandy backshore and coastal dune sysfig. 2 a: panoramic view of the fossiliferous layers exposed at las tronas bay; the red circles indicate the location of the deer antlers (1) and the tusk imprint (2). b: the imprint of the distal part of the elephant tusk. 110 palombo m.r., zedda m. fig. 3 the deposits correlated with mis 5c exposed at las tronas, the asterisks indicates the location of the tusk imprint: a) panoramic view of the northern sector of the las tronas bay, b) stratigraphic sketch of the deposits. fig. 4 the deposits correlated with mis 5c exposed at el tro’ bay: a) panoramic view. l9 indicates the location of the log b; b) log showing the deposits dated to mis 5c; c) outcrop details of unit 3b exposed in the northern sector of el tro’ bay (modified from pascucci et al., 2014, fig. 8). tem. in the southern part of the bay, at the bottom of the exposed sections, clast supported conglomerates prevail. locally some sandy low angled stratified layers and fragments of shells could be present. a clast-supported conglomerate with a medium to fine-grained sandy siltstone matrix unconformably overlies these layers. las tronas fossiliferous deposit has a small extension so that it is possible inferring its depositional context and fine chronology only by considering it in the wider context of the stratigraphic sections present in the adjacent areas. along the town coast, sandstone deposits are generally not well preserved because of the intense extractive activity and the number of quarries opened in the area since the roman time. the sections exposed at the el tro’ bay (figs. 1, 4) are among the best preserved and studied. the el tro' quaternary stratigraphic succession manly consists of sandy and/or conglomeratic layers, unconformably overlying the triassic carbonate bedrock. the succession has been subdivided in three unconformity bounded units: u3a, u3b and u4 (sechi et al., 2013, 2018 2020; pascucci et al., 2014). according to sechi et al. (2013, 2020), in the southern part of the bay, u3a consists of scattered deposits of fossil-rich clast-supported conglomerates, regarded as the submerged part of a small shallow gravelly pocket beach, and osl dated to mis 5e highstand (125±9 ka). in the central part of the bay, u3a consists of 50 cm thick clast-supported conglomerate, encrusted by an algal rim dated at 114±9 ka), and covered by a second clast-supported conglomerate, gently dipping seaward, and capped by a coarse sandstone (sechi et al., 2013; 2020 and pascucci el al., 2014). an unconformity surface separates these deposits from the overlain u3 b unit, consisting at the bottom of pebbly-cobbly conglomerates, passing sea-ward to a 2 m-thick medium to coarse sandstone capped by laminated high angle cross stratified 1 m-thick sandstone. the succession was considered as a mixed sand-gravel high-energy beach system, passing upward to a welldeveloped sandy backshore dated at 106±8, and to a dune system dated at 98±7 ka. therefore, the succession deposited during the mis 5c highstand (sechi et al., 2013; 2020 and pascucci el al., 2014). new researches and luminescence dating results (quartz osl and k-feldspar pirir290) confirm the chronological framework of the deposits cropping at el tro’ bay (cfr. pascucci et al., 2014; sechi et al., 2020). the new data (forereshore sediments qtz osl and kf dated at 94±8 of 100±6 ka respectively, backshore deposits dated at 106±8 ka) confirm that unit 3b, deposited during mis 5c. moreover the uppermost sandstones yield a qtz-osl minimum age of 76 ka and a pirir290 age of 103±7 ka (cfr. pascucci et al., 2014, 2019; sechi et al., 2020 and references therein). based on available data, such as the stratigraphic evidence available for el tro’ bay, the similarity shown by the deposits of the southern part of las tronas with those of el tro’ sections (particularly with the lenses of well sorted parallel or low angle laminated coarsegrained sandstone, locally showing surface laminas with 111 well-preserved deer footprints), and considering the gently dipping towards the sea of the medium-coarse, low to high angle cross stratified and well-cemented sandstone deposits cropping in the bay, the fossiliferous layers of the small stratigraphic sequence exposed in the northernmost part of las tronas bay can be correlated with the backshore and dune system deposits of unit 3b and thus referred to mis 5c. 3. the external imprint of the elephant tusk, description and remarks the external imprint likely corresponds to less than the longitudinal half of the distal portion of the elephant tusk. an extremely thin layer of tusk surface is still preserved in some parts, as well as few small fragments, with a millimetric thickness, of the external dentine cones (fig. 2-b). unfortunately, due to the small dimension and the preservation status of the dentine fragments neither the schreger lines nor their pattern can be detected, so that the most compelling diagnostic datum for identifying the genus the specimen belongs to (mammuthus or palaeoloxodon) is missing (e.g. palombo & villa 2007; ábelová, 2008). the length of the tusk imprint is about 480 mm and 410 mm along respectively the convex (inferior) and the concave (superior) edges. the height (chord of the arch of the transverse section) of the tusk imprint is 51 mm at the distal end, and about 39.5 mm near the apex of the tip. hypothesising that the tusk external imprint from las tronas bay may account for about a quarter of the tusk, the maximum circumference is supposed to be >160 mm and <175 mm. the convex and concave edges of the imprints run nearly parallel for most of the tusk section, except for the tip where the outline of the concave edge bents moderately downward. the imprint is gently and regularly curved upwards in the vertical plane (radius of curvature =35.7 mm), and the imprint tip is slightly directed upwards. the dimensions of the las tronas imprint indicate that the tusk was similar in size to the fragment of mammuthus lamormorai tusk found at guardia pisano hill (gonnesa, sw sardinia) that is the only tusk belonging to the sardinian endemic mammoth known to date (palombo et al., 2012, figure 2). in the small fragment from the guardia pisano hill (maximum length =118 mm, estimated circumference at the broken proximal surface =223 mm), the diameter of the pulpar cavity, still detectable on the natural transverse section of the broken distal surface, is less than 2 mm, suggesting that the fragment may correspond to a distal intralveolar plus a proximal extralveolar part of the tusk. the las tronas tusk imprint does not show any evidence of twist and its gentle curvature seems to be mostly developed in a single plane, as seen in palaeoloxodon. therefore, the tusk that left the imprint apparently did not have the curving, twisting form, gradually bending inwards that gives to the mammuthus tusks the characteristic spiral shape. the curvature index (ci =chord length vs external length ratio =0.82) is, however, inferior to the value calculated for the majority of the a new elephant remain in the late pleistocene of nw sardinia straight tusked elephants found in the italian peninsula [e.g. grotte santo stefano, viterbo (trevisan, 1949) =0.97; ceprano, frosinone (ambrosetti, 1963) =0.85; pignataro interama, frosinone (adult female, fide maccagno, 1962) =0.98; pignataro interama, frosinone (juvanile individual, d’erasmo and moncharmont zei, 1955) =0.98; la polledrara di cecanibbio, roma (preliminary personal data, mrp) variation range =0.850.97, m =0.94]. noteworthy, in the majority of the italian p. antiquus, the ci value augments from the proximal to the distal part of the tusk (e.g. ambrosetti, 1963, pag. 209), suggesting that ci of the part near to the tusk tip is in general higher than that calculated for the las tronas imprint. the latter is similar to the maximum value of the variation range of dwarf mammoth, mammuthus exilis from the channel islands, california (variation range =0.35-0.87, m =0.74) (agenbroad, 2003) but it is similar, for instance, to the average ci value calculated for the tusks of juvenile individuals of mammuthus primigenius from yana rhs, artic siberia (variation range =0.630.94, m =0.84), while it is higher than that of adult individuals from the same locality (variation range =0.530.75, m =0.62) (pitulko et al., 2015). the ci value of the curvature index of the distal part of the las tronas tusk is higher than that estimated for some italian mammuthus representatives, such as mammuthus meridionalis from leffe, bergamo (ci =0.79, vialli, 1956), scoppito, l’aquila [ci =0.68 (total tusk length), ci =0.60 (extralveolar length), maccagno, 1962], mammuthus trogontherii, via flaminia km 7.2, roma [ci =0.79 (incomplete tusk, the distal is missing), palombo, 1972], mammuthus primigenius from tarquinia, viterbo (ci =0.70, ambrosetti, 1964), asolo (ci =0.60) and vidor (ci =0.68), treviso (reggiani & sala, 1992). all in all, the morphological and dimensional evidences provided by the external imprint of the elephant tusk found at las tronas bay are not conclusive enough for a firm taxonomical identification. however, the size and curvature of elephant permanent tusks show a wide range of inter and intra-specific variation because of their indeterminate growth, ontogenetic changes and marked sexual dimorphism (see e.g. smith & fisher, 2013 and references therein). moreover, in m. exilis, the tusk length and maximum diameters are approximately 50% those of its continental ancestor m. columbi, while the average ci value is definitely higher (=0.84 in m. exilis, =0.64 in m. columbi from channel islands) (agenbroad, 2003; muhs et al., 2015). tusks of adult m. exilis individuals do not show the curving, twisting form typical of mammuthus (which is also evident, though not strongly marked, in m. columbi), so that they are similar in shape to the tusk of young m. primigenius. consequently, it could be speculated that the tusks of adult dwarfed mammoths exhibit some juvenile features, thought more data are required to validate the soundness of this hypothesis. if, for instance, paedomorphic traits characterise the skull of the extremely dwarfed palaeoloxodon ex gr. p. falconeri from spinagallo cave (siracusa, sicily), similar evidence is not clearly detectable in tusks (palombo, 2003 and references therein). moreover, in palaeoloxodon ex gr. p. mnaidriensis from puntali cave (palermo, sicily) (ferretti, 2008), moderately reduced in size, with a stature rougly similar to m. lamarmorai, the skull does not show any paedomorphic traits, while the tusks are even more twisted than in its continental ancestor p. antiquus. all things considered, the few available data support the idea that the tusk from las tronas bay may belong to the only elephant species known in sardinia. thus, to identify the tusk imprint as m. lamarmorai, seems to be to most parsimonious, even if provisional, hypothesis. 4. final remarks although endemic elephants have been reported from a number of eastern and western mediterranean islands, the majority originated from the mainland straight-tusked elephant palaeoloxodon antiquus, while dwarf mammoth remains are recorded only from crete and sardinia. on crete, a few remains of adult elephants (a lower third molariform tooth clearly showing mammuthus morphological features, some fragment of other teeth, a humerus and ribs) have been reported from cape maleka 1 (chania). the inferred age of the deposits (late 112 palombo m.r., zedda m. fig. 5 a map of sardinia showing localities where elephant remains were discovered: 1: tramariglio (molariform tooth); 2: campo giavesu (two molariform teeth); 3-4 las tronas bay (external imprint of a tusk fragment) and an undefined point along the southern alghero coast (incomplete tibia); 5: san giovanni di sinis (molariform tooth); 6-8: guardia pisano (skeleton and tusk fragment) and funtana morimenta (footprints). references ábelová m. (2008) schreger pattern analysis of mammuthus primigenius tusk: analytical approach and utility. bulletin of geosciences, 83(2), 225-232. agenbroad l.d. (2003) new absolute dates and comparisons for california’s mammuthus exilis. deinsea, 9(1), 1-16. ambrosetti p. (1963) an elephant tusk found near ceprano (southern latium). geologica romana, 2, 207-212. ambrosetti p. (1964) l’elephas primigenius di tarquinia (lazio settentrionale). geologica romana, 3, 367 -381. andreucci s., clemmensen l.b., murray a., pascucci v. (2010) middle to late pleistocene coastal deposits of alghero, northwest sardinia (italy): chronology and evolution. quaternary international, 222, 3-16. andreucci s., buylaert j., panzeri l., sechi d., sanna l., pascucci v. (2011) testing the reliability of the optically stimulated luminescence method in a coastal system on sardinia. rend. online soc. geol. it., 17, 15-16, andreucci s., sechi d., buylaert j.p., sanna l., pascucci v. (2017) post-ir irsl290 dating of krich feldspar sand grains in a wind-dominated system on sardinia. marine and petroleum geology, 87, 91-98. casini l., andreucci s., sechi d., huang c.y., shen c.c., pascucci v. (2020) luminescence dating of late pleistocene faults as evidence of uplift and active tectonics in sardinia, w mediterranean. terra nova, 32(4), 261-271 comaschi caria i. (1956) specie nuova di cervo nel quaternario di alghero (sardegna). estratto dal fasc. 3-4 vol. xxv 1955. cagliari. comaschi caria i. (1968) fossili marini e continentali del quaternario della sardegna. in: atti x congr. intern. st. sardi, 140-239. d’erasmo g., moncharmont zei m. (1955) il cranio giovanile di elephas antiquus italicus di pignataro interamna, nella valle del liri. memorie accademia scienze fisiche e naturali, 3, 1-32. ferretti m.p. (2008) the dwarf elephant palaeoloxodon mnaidriensis from puntali cave, carini (sicily; late middle pleistocene): anatomy, systematics and phylogenetic relationships. quaternary international, 182(1), 90-108. gliozzi e. (1985) alcune ossa appendicolari di loutra f oss i l e de l qua te rna r i o d i a lghe ro (sardegna). bollettino della società paleontologica italiana, 24(2-3), 137-144. herridge v.l., lister a.m. (2012) extreme insular dwarfism evolved in a mammoth. proceedings of the royal society b: biological sciences, 279(1741), 3193-3200. larramendi a., palombo m. r. (2015) body size, biology and encephalization quotient of palaeoloxodon ex gr. p. falconeri from spinagallo cave (hyblean plateau, sicily). hystrix, 26(2). maccagno a.m. (1962) l’elephas meridionalis nesti di contrada “madonna della strada” scoppito (l’aquila). in: atti accademia scienze fisiche e naearly pleistocene) and the small size of the specimens make the crete mammoth, mammuthus creticus, the smallest insular dwarf mammoth known to date (herridge & lister, 2012), similar in size to the smallest endemic straight-tusked elephants p. falconeri from malta and sicily high at the shoulder about 1 m or a little more (larramendi & palombo, 2015). on western sardinia, a few elephant remains have been reported from late middle to late pleistocene deposits, while no elephant remains are known to date in other parts of the island (fig. 5). these remains have been ascribed to the mammuthus genus, based on the taxonomically informative characters shown by the molariform teeth found at campo giavesu (giave, sassari) and san giovanni di sinis (oristano), and on the schreger line patterns shown by the tusk fragment from guarda pisano (gonnesa) hill (palombo et al., 2005, 2012 and references therein). based on this evidence, it has been assumed that even the specimens without firm diagnostic features (e.g the tooth from tramariglio and the incomplete tibia from the southern coast of alghero) may belong to the same genus, as well as the incomplete postcranial skeleton, found in 1881 on the slope of guardia pisano hill (gonnesa) and afterward described by major as a new species,“elephas lamarmorae”, of an endemic dwarfed elephant, which stood about 1.40 m at the shoulder (palombo et al., 2012; zoboli et al., 2018). as a result, all the elephant remains recorded to date in sardinia have been attributed to the dwarf mammoth m. lamarmorai (cf. palombo et al., 2017b and references therein; pillola & zoboli, 2017). the paucity of fossils, the uncertainties about the chronology of some remains, which prevents knowing if the differences and the potential dimensional scaling shown by the molariform teeth from different localities (palombo et al., 2005) result from a progressive dwarfing due to anagenetic evolution, or if mainland mammoths entered the island more than once. considering in addition the impossibility to define the actual dimensional range of m. lamarmorai and the well-known variability characterising elephant size, the question remains unanswered as to whether or not only one species inhabited the island (see discussion in palombo et al., 2012, 2017b). although the finding of the external imprint of the elephant tusk tentatively ascribed to m. cfr. m. lamarmorai does not provide any useful hint for resolving the question, it is however of some significance because it is the first sardinian elephant remain with a firm chronological constrain, confirming the presence of elephant populations in nw sardinia at least since mis 5c. acknowledgments the authors thank the reviewers d. mol and d. sechi and a. bertini (associate editor at amq) for their comments and suggestions to the previous version of the manuscript. thanks are also due to a. castellaccio for reporting to one of us (mz) the presence of fossil remains at las tronas bay. 113 a new elephant remain in the late pleistocene of nw sardinia turali, napoli, 4, 1-129. malatesta a. (1954) primo dente di elefante fossile rinvenuto in sardegna. quaternaria, 1, 97-105. malatesta a. (1970) cynotherium sardous studiati an extinct canid from the pleistocene of sardinia. mem. ist. ital. paleontol. umana, ns, 1, 1-72. malatesta a. (1977) the skeleton of nesolutra ichnusae sp. n., a quarternary otter discovered in sardinia. geol. romana, 16, 173­209. malatesta a., settepassi f. (1954) risultati del rilevamento 192 (alghero isola di sardegna). iii. fossili delle formazioni continentali quaternarie. boll. serv. geol. ital., 76, 31-39. muhs d.r., simmons k.r., groves l.t., mcgeehin j. p., schumann r.r., agenbroad l. d. (2015) late quaternary sea-level history and the antiquity of mammoths (mammuthus exilis and mammuthus columbi), channel islands national park, california, usa. quaternary research, 83(3), 502-521. palombo m.r. (1972) un cranio di elephas primigenius della via flaminia (roma). geologica romana 11, 199-228. palombo m.r. (2003) elephas? mammuthus? loxodonta? the question of the true ancestor of the smallest dwarfed elephant of sicily. deinsea, 9(1), 273-292. palombo m.r., ibba a. (2008) porto conte bay. in: palombo, m.r., kotsakis, t., pillola, g. (eds.), fossil mammalian biotas of sardinia, euromam fieldtrip guide-book, sardinia september 2008. university of cagliari, cagliari, 16-21. palombo m.r., villa p. (2007) l’utilità dell’analisi delle lineee di schreger nello studio dei proboscidati. in: fiore i., malerba g., chilardi s. (eds.), atti del 3 congresso internazionale di archeozoologia, 2 (2005). collana del bollettino di paletnologia italiana, roma, studi di paletnologia, 35-44. palombo m.r., ginesu s., melis r.t., sias s. (2005) the endemic elephants from sardinia: an unsolved problem. monografies societat d'història natural de les balears, 12, 245-254. palombo m.r., ferretti m.p., pillola g.l., chiappini l. (2012) a reappraisal of the dwarfed mammoth mammuthus lamarmorai (major, 1883) from gonnesa (south-western sardinia, italy). quaternary international, 255, 158-170. palombo m.r., antonioli f., lo presti v., mannino m.a., melis r.t., orru p., stocchi p., talamo s., quarta g., calcagnile l., deiana g., altamura s. (2017a) the late pleistocene to holocene palaeogeographic evolution of the porto conte area: clues for a better understanding of human colonization of sardinia and faunal dynamics during the last 30 ka. quaternary international, 439, 117-140. palombo m.r., zedda m., melis r.t. (2017b) a new elephant fossil from the late pleistocene of alghero: the puzzling question of sardinian dwarf elephants. comptes rendus palevol, 16(8), 841-849. 114 pascucci, v., sechi, d., andreucci, s. (2014) middle pleistocene to holocene coastal evolution of nw sardinia (mediterranean sea, italy). quaternary international, 328, 3-20. pascucci v., frulio g., andreucci s. (2019) new estimation of the post little ice age relative sea level rise. geosciences, 9(8), 348. pillola g.l., zoboli d. (2017) dwarf mammoth footprints from the pleistocene of gonnesa (southwestern sardinia, italy). bollettino della società paleontologica italiana, 56(1), 57-64. pitulko v.v., pavlova e.y., nikolskiy, p.a. (2015) mammoth ivory technologies in the upper palaeolithic: a case study based on the materials from yana rhs, northern yana-indighirka lowland, arctic siberia. world archaeology, 47(3), 333-389. reggiani p., sala b. (1992) i mammut del veneto. memorie scienze geologiche università di padova 44, 171-191. sechi d., andreucci s., pascucci v. (2013) high energy beaches system developing during mis 5c high sea-stand (100 ka), north-west sardinia, italy. journal of mediterranean earth sciences 5, 133-136. sechi d., andreucci s., pascucci, v. (2018) intertidal upper pleistocene algal build-ups (trottoir) of nw sardinia (italy): a tool for past sea level reconstruction. journal of mediterranean earth sciences, 10. 167-171. sechi d., andreucci s., stevens t., pascucci v. (2020) age and significance of late pleistocene lithophyllum byssoides intertidal algal ridge, nw sardinia, italy. sedimentary geology, 400, 105618. smith k.m., fisher d.c. (2013) sexual dimorphism and inter-generic variation in proboscidean tusks: multivariate assessment of american mastodons (mammut americanum) and extant african elephants. journal of mammalian evolution, 20(4), 337355. trevisan l. (1949) lo scheletro di elephas antiquus italicus di fonte campanile (viterbo), palaeontographia italica, 44(1948-49), 1-78. vialli v. (1956) sul rinoceronte e l'elefante dei livelli superiori della serie lacustre di leffe (bergamo). mem. soc. ital. sci. nat., 12 (1), 1-67. zoboli d., pillola g.l., palombo m.r. (2018) the remains of mammuthus lamarmorai (major, 1883) housed in the naturhistorisches museum of basel (switzerland) and the complete “skeletonpuzzle”. bollettino della società paleontologica italiana, 57(1), 45-57. ms. received: august 22, 2020 revised: october 31, 2020 accepted: november 1, 2020 available online: november 30, 2020 imp.04santo nuove ipotesi sulla formazione dei piping sinkhole in aree alluvionali: il caso della piana di forino (avellino, campania) del prete s.*, giulivo i.**, santo a.*** * federazione speleologica campana **geologo dirigente ufficio difesa suolo regione campania ***dipartimento di ingegneria idraulica, geotecnica ed ambientale università di napoli “federico ii”, santo@unina.it riassunto: s. del prete et al., nuove ipotesi sulla formazione dei piping sinkhole in aree alluvionali: il caso della piana di forino (avellino, campania) (it issn 0394-3356, 2008). vengono esposti i risultati di uno studio eseguito nel bacino endoreico di forino (av) e proposta una nuova ipotesi sulla genesi di piping sinkhole in aree alluvionali. lo studio si è avvalso di indagini in sito che hanno permesso di ricostruire la stratigrafia di sottosuolo (primi 50 metri di profondità), caratterizzata dalla presenza di un riempimento alluvionale di natura limoso-sabbiosa, poggiante su di un substrato poco permeabile (ignimbrite campana e flysch miocenici). è stata quindi esclusa la presenza di calcari e di vuoti carsici per almeno i primi 50 m di profondità. nell’area sono stati censiti 8 sinkhole, alcuni recenti, altri più antichi e ormai completamente riempiti da materiale di riporto. le perforazioni effettuate in alcuni di essi e l’osservazione diretta dello sprofondamento più recente (12 giugno 2005), hanno evidenziato che i vuoti si sono formati a partire da circa 25 m di profondità e che hanno interessato i terreni sabbioso-limosi alluvionali. i sinkhole si allineano lungo la direzione di drenaggio preferenziale della falda presente nel corpo alluvionale e sono concentrati alla base del versante settentrionale di m. romola che costituisce, quindi, il settore della piana più suscettibile a questi fenomeni. lo studio ha dimostrato che i vuoti si generano per fenomeni di erosione causati da una circolazione idrica sotterranea, attiva in concomitanza di periodi molto piovosi e caratterizzata, probabilmente, da moti turbolenti. tale circolazione si instaura al contatto tra il materiale sabbioso-limoso ed i sottostanti strati poco permeabili (ignimbrite campana e flysch miocenici). è molto probabile che la circolazione idrica sotterranea sia alimentata anche da falde sospese ed in rete carsica presenti nei massicci carbonatici che circondano la piana. per quanto riguarda l’erosione dei notevoli volumi asportati (alcune migliaia di m3) è ipotizzabile che essi siano smaltiti da inghiottitoi sepolti, presenti lungo il margine orientale della conca endoreica. i risultati di questo studio rappresentano un primo importante contributo per successive ricerche mirate all’identificazione di altri vuoti sotterranei che potrebbero essere molto prossimi alla superficie topografica e creare, quindi, situazioni di alto rischio. abstract: s. del prete et al., new genetic hypothesis about piping sinkhole formation in alluvial plain: the case study of forino (avellino, campania) (it issn 0394-3356, 2008). this paper deals with sinkholes phenomena occurred in the intramontane basin of forino village (campania, southern italy). a new genetic hypothesis about piping sinkhole formation in alluvial plain is proposed. aiming at the definition of the underground stratigraphy, some boreholes have been drilled down to the depth of 50 meters. they showed the presence of an alluvial silty and sandy body laying on a impermeable substratum made up of tuff (campanian ignimbrite) and miocene flysch deposits. therefore, in the first 50 m of the depth, the presence of calcareous bedrock and caves can be certainly excluded. eight sinkholes have been observed in the area; some of them are recent, other are older and completely filled in with reworked material. some of the boreholes were carried out inside and around the more recent sinkhole (12 june 2005) and they showed it had started forming at about 25 m of depth, affecting sandy and silty alluvial deposits. the studied sinkholes are lined up with the flow direction of the groundwater located within the alluvial body at the base of the northern slope of m. romola. the last one is the sector more susceptible for this phenomena. the collected data suggest that the sinkholes developed because the underground water circulation, probably with turbulent regime, produced erosion phenomena in the sandy-silty alluvial deposits, causing void formation. this circulation is only active during rainy day periods and is located at the contact between the impermeable substratum (top of campanian ignimbrite end miocenic flysch) and the sandy and silty alluvial deposits. probably this water table is also fed laterally by groundwater coming from the carbonate massifs surrounding the plain. as far as the problem of volumes removed (some thousands of m3) is concerned, the presence of buried ponors, along the eastern edge of the endoreic basin, which can transfer in depth the sandy materials, is hypothesised. the results of this study represents a first step for new researches aimed at recognizing the presence of other underground voids that could be very near to the topographic surface producing high risk situations. parole chiave: sinkhole, suffosione profonda, polje, campania, appennino meridionale. key words: sinkhole, deep piping, polje, campania region, southern apennines il quaternario italian journal of quaternary sciences 21(2), 2008 395-408 1. premessa a livello mondiale è ormai acquisito che il verificarsi di un improvviso sprofondamento (sinkhole) costituisce un grave problema nella gestione delle infrastrutture presenti sul territorio soprattutto a causa della difficile localizzazione e previsione spazio-temporale del fenomeno. recentemente anche in italia la comunità scientifica ha dedicato particolare attenzione allo studio dei sinkhole, soprattutto dopo alcuni casi che hanno interessato centri abitati; le prime sintesi sono state pubblicate negli atti di alcuni convegni, dedicati a questa tematica (aa.vv., 2000; 2004). i sinkhole di origine naturale si originano in contesti geologici ed idrogeologici piuttosto complessi; essi si aprono sia in piane alluvionali (cover collapse sinkhole, deep piping sinkhole, subsidence sinkhole) che su massicci carsici (cover sinkhole, collapse sinkhole, solu396 s. del prete, i. giulivo & a. santo tion sinkhole, subsidence sinkhole). generalmente la loro genesi è legata alla presenza di alcuni fattori predisponenti quali: substrato carsificabile, copertura clastica a granulometria variabile, circolazione idrica sotterranea con falde in pressione, presenza di fluidi mineralizzati, presenza di lineamenti tettonici attivi ed eventi sismici che possono concorrere con vario grado di causalità (sinclair & stewart, 1985; facenna et al., 1993; berti et al., 2000; capelli et al., 2000; 2004; ciotoli et al., 2001; nisio, 2003; closson, 2004; gutiérrez, 2004; ferrelli et al., 2004; nisio et al., 2004; nisio & scapola, 2005; waltham et al., 2005). in campania sono stati circa 100 sinkhole (del prete et al., 2004) che interessano diversi contesti geomorfologici e che coinvolgono differenti litologie (fig. 1). è stato osservato che i meccanismi d’innesco possono essere molto diversi a seconda dei casi (del prete et al., 2004; del prete & santo, 2005; cozzolino et al., 2007; santo et al. 2007) e non ancora del tutto chiari soprattutto per quei fenomeni che interessano le aree alluvionali. in questa nota vengono descritti alcuni fenomeni di piping sinkhole recentemente verificatisi nel bacino alluvionale di forino (av). a seguito di alcuni sopralluoghi e di dati forniti dal comune, si è potuto accertare che l’area è stata interessata più volte in passato da improvvisi sprofondamenti. visto il crescente sviluppo urbano del centro abitato nella piana e grazie anche ad un finanziamento dell’ufficio difesa suolo della regione campania, è stato predisposto un primo programma di fig. 1 schema geologico della campania con l’ubicazione delle aree interessate dalla presenza di sinkhole. legenda: 1) depositi delle piane costiere e delle conche intramontane; rocce vulcaniche s.l. (quaternario); 2) depositi terrigeni (mesozoico-terziario); 3) rocce carbonatiche (mesozoico-terziario); 4) sinkhole su versanti carbonatici; 5) sinkhole in aree di piana alluvionale. il riquadro indica l’area di studio. geological sketch map of campania and location of sinkhole: 1) coastal plain and endoreic basins deposits; volcanic rocks s.l. (quaternary); 2) flysch deposits (mesozoic-tertiary); 3) deposits of carbonatic platform (mesozoic-tertiary); 4) sinkhole along carbonate slope; 5) sinkhole in alluvial plain. the square is refer to the area of study. indagini finalizzato alla comprensione della genesi dei sinkhole. le prime indagini in sito hanno permesso di giungere ad interessanti considerazioni sulla loro possibile genesi. 2. inquadramento geologico-geomorfologico ed idrogeologia della conca di forino la conca di forino costituisce un bacino endoreico di circa 10 km2 ed altitudine media di 400 m s.l.m. localizzato pochi km a sud della città di avellino tra i 397nuove ipotesi sulla formazione ... rilievi carbonatici di pizzo d’alvano, e dei m.ti picentini (fig. 2). la genesi della depressione è associata all’azione di faglie attive durante il plio-quaternario che hanno dislocato le dorsali calcareo mesozoiche su cui poggiano, in trasgressione, successioni terrigene mioceniche. nel centro della piana, il substrato miocenico ed i sottostanti calcari risultano ribassati a gradinata sino ad un massimo di poche centinaia di metri (fig. 3). il riempimento quaternario è costituito da potenti successioni fluvio-lacustri, per lo più di natura limo-argillosa, che sono ricoperte da tufi dell’ignimbrite campana (39.000 fig. 2 schema geologico della piana di forino. legenda: 1) depositi piroclastici rimaneggiati e depositi alluvionali (pleistocene sup.olocene); 2) detrito di versante (pleistocene sup.-olocene); 3) depositi in facies di flysch (miocene); 4) calcari mesozoici; 5) faglia; 6) sorgente; 7) conoide alluvionale; 8) inghiottitoio; 9) sinkhole; 10) traccia di sezione di fig. 3. geological map of the forino plain. legend: 1) pyroclastic and alluvial deposits (upper pleistocene-holocene); 2) detritical talus (upper pleistocene-holocene); 3) miocenic flysch; 4) mesozoic limestones; 5) fault; 6) spring; 7) alluvial fan; 8) ponor; 9) sinkhole; 10) geological cross section of fig. 3. anni; de vivo et al., 2001) e poi da alternanze di limi e sabbie legate a piroclastiti rimaneggiate. gli ultimi 15÷20 m del riempimento della piana sono costituiti da una maggiore presenza di depositi piroclastici da caduta provenienti dal vicino distretto vulcanico del sommavesuvio. l’assetto geomorfologico è quello tipico dei bacini endoreici nei quali le acque di ruscellamento superficiale creano frequentemente fenomeni di trasporto solido e alluvionamento favoriti anche dalla notevole estensione di depositi piroclastici sui versanti. in particolare, nel settore meridionale, alla base dei versanti del monte romola e del monte piesco, aste a regime torrentizio alimentano diversi corpi di conoide (fig. 2). le acque di ruscellamento superficiale una volta raggiunta la piana, sono in gran parte incanalate verso l’inghiottitoio di celzi (fig. 2), tuttavia, in concomitanza di intensi eventi meteorici, l’inghiottitoio non riesce a smaltire la totalità delle acque provocando ripetuti fenomeni di ristagno che coinvolgono anche il centro urbano. per quanto riguarda l’assetto idrogeologico, la piana di forino rientra nella più ampia idrostruttura dell’unità dei monti di avella e partenio, a nord, e di quella del pizzone-alvano, a sud (civita et al., 1970; celico, 1979) la cui falda di base drena preferenzialmente verso sw in direzione degli importanti gruppi sorgivi di sarno e nocera. santo et al., 1998, attraverso il censimento dei pozzi per uso irriguo e con profondità variabile dai 20 ai 50 m, hanno rilevato la presenza di una falda alta in quota localizzata nel riempimento alluvionale della piana con deflusso preferenziale orientato da wnw verso ene (fig. 4). la falda si localizza a circa 370 m s.l.m e cioè circa 30 sotto il piano campagna. il disegno piezometrico evidenzia un’alimentazione dai vicini massicci carbonatici ed in particolare da quelli localizzati a nw e, subordinatamente, da quelli presenti a sw della piana (santo et al., 1998). più in profondità, ad una quota di circa 250 m s.l.m., è presente la falda di base dei calcari il cui recapito è rappresentato dal gruppo sorgivo laura e labso (celico, 1979). la conca di forino, quindi, è caratterizzata dalla presenza di due falde la più alta delle quali si localizza nel corpo alluvionale sabbioso limoso ed è alimentata per travaso dai calcari; la più profonda si imposta nei calcari mesozoici e sarebbe separata dalla prima per l’interposizione di materiali lacustri e dei flysch miocenici. 3. i sinkhole della piana di forino il 12 giugno del 2005 alle ore 18.30 in contrada petrosa (località celzi) nel comune di forino (avellino) si è aperta improvvisamente una voragine a pochi metri da una strada comunale e da alcune abitazioni rurali. lo sprofondamento ha coinvolto terreni prevalentemente di natura limoso-sabbiosa ed ha inghiottito alcuni alberi di nocciolo; al momento della formazione aveva un diametro di circa 12 m e profondità di circa 25 m (fig. 5). la zona è stata subito recintata ma nei mesi successivi, a causa di franamenti periodici del ciglio, la voragine si è ampliata fino a raggiungere un diametro di 25 m ed una profondità di circa 12 m nel marzo del 2007 (fig. 6). il primo passo dello studio è stato quello di effettuare un accurato censimento dei sinkhole presenti nella piana; ciò è stato possibile attraverso testimonianze locali ed un’attenta analisi delle morfologie del terreno e della cartografia storica. nonostante molti di essi siano stati ricolmati ed obliterati, ne sono stati censiti con certezza 8 (fig. 2), due dei quali si sono verificati 398 fig. 3 sezioni geologiche del bacino di forino. 1) depositi piroclastici rimaneggiati e depositi alluvionali (pleistocene sup.-olocene); 2) detrito di versante (pleistocene sup.-olocene); 3) depositi in facies di flysch (miocene); 4) calcari mesozoici; 5) faglia; 6) sondaggi (da santo et al., 1998 mod.). cross section of the forino plain. legend: 1) reworked pyroclastic and alluvial deposits (upper pleistocene-holocene); 2) detritical talus (upper pleistocene-holocene); 3) miocenic flysch; 4) mesozoic limestones; 5) fault; 6) borehole (from santo et al., 1998, mod). s. del prete, i. giulivo & a. santo particolarmente interessante sono le evidenze del sinkhole sk5 ubicato nell’estremo settore sud orientale della conca di forino (fig. 7). sul suo fondo sono state osservate chiare evidenze di riattivazioni recenti per la presenza di radici tranciate dai movimenti di subsidenza e, lungo i suoi bordi, sono evidenti fratture concentriche con piccole scarpate che, per richiamo verso il centro, individuano più ordini di superfici terrazzate associate all’ampliamento del sinkhole. per alcuni sinkhole la memoria storica è ancora 399 fig. 4 isopiezometriche della falda della piana di forino (da santo et al, 1998 mod.). legenda: 1) curva isopiezometrica e relativa quota s.l.m.; 2) sinkhole; 3) inghiottitoio; 4) sorgente; 5) direzione di drenaggio sotterraneo; 6) sondaggio; 7) flysch miocenici; 8) calcari mesozoici. isopiezometric curves of the forino plain (from santo et al., 1998, mod.). legend: 1) isopiezometric curve and altitude above sea-level; 2) sinkhole; 3) ponor; 4) spring; 5) groundwater flow direction; 6) borehole; 7) miocene flysch; 8) mesozoic limestones. fig. 5 i l sinkhole di contrada petrosa pochi giorni dopo la sua formazione (25 giugno 2005; diametro circa 12m e profondità di circa 25m). the contrada petrosa sinkhole few days later its formation (2005, june 25; diameter 12m; depth 25mt). nel marzo e nel giugno 2005. i sinkhole sono ubicati tutti alle falde del rilievo di m. romola (fig. 2) e di questi 5 sono ancora ben preservati, mentre gli altri 3 sono appena accennati da blande concavità del terreno. tra i sinkhole riportati in fig. 2, quelli codificati con la sigla sk3, sk4 e sk5 si presentano come depressioni circolari del diametro di 20÷30 m talora bordate da pareti subverticali ancora ben preservate alte fino a 3÷4 m. nuove ipotesi sulla formazione ... viva nella popolazione più anziana, come dimostra l’attribuzione di toponimi come nel caso della “fossa donna teresa” (cfr sk3 in fig. 2) che è ubicata al margine di un conoide alluvionale. secondo alcune fonti locali la sua formazione risalirebbe ad almeno 80 anni fa e sul suo fondo si tramanda della presenza di un piccolo stagno ove i locali si recavano a fare il bagno. poche centinaia di metri a nord di questo sinkhole, sono presenti alcune (almeno 3) blande depressioni chiuse. le fonti locali, tuttavia, tramandano a memoria d’uomo, solo di un fenomeno in località “fossa di zarra” (sk2 in fig. 2). nella stessa zona, tuttavia, testimonianze locali riportano che durante una trivellazione per ricerca d’acqua alcune aste sono sprofondate e andate perse per il rinvenimento di un vuoto associato ad una cavità. anche in corrispondenza del sinkhole sk1 è ancora riconoscibile una blanda depressione circolare chiusa nel terreno che, secondo fonti locali, sarebbe da riferire al “relitto” di un fenomeno di sprofondamento risalente ad oltre 80 anni fa. gli eventi recenti, infine, sono quelli che riguardano il sinkhole sk6, risalente al marzo 2005, e l’sk7 del giugno 2005 in contrada petrosa. il primo si presenta come una forma avente un diametro di circa 15 m ed una profondità di circa 3 m (fig. 8). lungo il bordo sono presenti fratture concentriche, mentre il fondo si presenta molto irregolare con 400 fig. 6 panoramica della stratigrafia visibile lungo le pareti del sinkhole di contrada petrosa (foto del marzo 2007). legenda: a) suoli recenti con due livelli di eruzioni vulcaniche storiche (472d.c. e 1631); b) pomici dell’eruzione vulcanica di mercato/ottaviano, 8000 anni fa; c) cineriti rimaneggiate (limi sabbiosi) con pomici e locali livelli di sabbie e paleosuoli; d) pomici grigie e scorie probabilmente riferibili all’eruzione di agnano rimaneggiate in ambiente alluvionale; e) cineriti (limi sabbiosi) pedogenizzate con locali livelli di sabbie fini. view of stratigraphy along the wall of contrada petrosa sinkhole (photo of 2007, march). legend: a) present soils with two levels of recent tephra (472 d.c. and 1631 eruptions); b) tephra of mercato/ottaviano eruption (8000 y. b.p); ash and pumice interbedded with sands and paleosoil levels; d) grey pumices and scoria of agnano eruption reworked in alluvial environment; e) weathered ash levels with thin sandy layers. fig. 7 panoramica del sinkhole sk5 ubicato sullo stralcio di fig. 2. sono ben evidenti (linea a punti) più ordini di superfici di collasso. view of sinkhole sk5 (cfr. fig. 2). it is evident the presence (white dot line) of different collapse surfaces. s. del prete, i. giulivo & a. santo alberi sradicati. il fenomeno più recente, invece, si è verificato intorno alle 18.30 del 12 giugno 2005. esso presentava un diametro circolare iniziale di 12 m ed una profondità di almeno 25 m per un volume complessivo di circa 2500 m3 (fig. 5). è da segnalare che al momento dello sprofondamento non si sono avute risalite di acqua, sebbene alcuni testimoni locali, hanno dichiarato di aver sentito passaggio di acqua in profondità. 4. piano di indagini e stratigrafia dei sinkhole per poter comprendere l’assetto geologico stratigrafico di dettaglio dei terreni nel quale si è generato lo sprofondamento di contrada petrosa (cfr. sk7), sono state eseguite alcune perforazioni a carotaggio continuo, tutte condizionate a piezometro, al fine di poter monitorare le oscillazioni della falda. in un primo momento sono stati eseguiti 4 sondaggi lungo il perimetro dello sprofondamento del giugno 2005 (sondaggi s1, s2, s3, s4 in fig. 9); successivamente, dopo aver riempito il sinkhole con terreno vegetale esso è stato riperforato nel suo centro (sondaggio s7 in fig. 9). altri 2 sondaggi sono stati eseguiti all’interno dei sinkhole sk2 e sk3 che risultano ormai quasi completamente interrati. di seguito sono riportate le stratigrafie dei sondaggi eseguiti: il sondaggio s1 è stato eseguito 22 m a ne del sinkhole di contrada petrosa ed ha raggiunto una profondità di 38 m. a partire dal piano campagna è stato incontrato uno spessore di circa 10 m di depositi piroclastici da caduta ascrivibili ad eruzioni del somma vesuvio (eruzioni di mercato risalente a 8000 anni fa, rolandi et al., 1993, probabilmente di agnano risalente a 10.550 anni fa; di vito et al., 1999) in alternanza con livelli cineritici pedogenizzati, livelli sabbiosi e paleosuoli che poggiano su circa 12 m di alternanze di piroclastiti rimaneggiate in ambiente alluvionale e di fall pomiceocineritici ascrivibili, probabilmente, alle eruzioni di sarno (17.000 anni fa; rolandi, 1997). nella parte bassa di questo intervallo, tra i 19 e 22 m, sono presenti sabbie alluvionali fini. la prima decina di metri della stratigrafia appena descritta ha trovato anche riscontro con quella affiorante lungo le pareti del sinkhole sk7 (fig. 6). un paleosuolo divide nettamente i depositi alluvionali dalla sottostante ignimbrite campana (39.000 anni) che è stata carotata per uno spessore di circa 10m e si presenta lapideo di colore giallo. il tufo, infine, poggia su flysch arenacei del substrato miocenico. il sondaggio s2 è stato eseguito circa 25 m a sw rispetto al centro dello sprofondamento di contrada petrosa ed ha una raggiunto una profondità di 52 m. in sintesi la perforazione ha incontrato per i primi 6 m livelli vulcanici cineritici, spesso pedogenizzati ed alternati a livelli pomicei rimaneggiati; a seguire, sino a circa 23 m di profondità, sono state incontrate prevalentemente sabbie e limi sabbiosi di natura piroclastica ma spesso rimaneggiati in ambiente alluvionale. da 23 m sino a circa 40 m si ritrovano depositi cineritici e tufacei dell’ignimbrite campana che poggiano sul substrato arenaceo, carotato per 12 m sino alla profondità di 52 m dal piano campagna. il sondaggio s3 è ubicato circa 50 m a sud dello sprofondamento di contrada petrosa e si è spinto fino alla profondità di 30 m. per i primi 18 m sono state incontrate alternanze 401 fig. 8 il sinkhole sk6 ( marzo 2005) dopo due anni (marzo2007). view of 2005 march sinkhole sk6 two years later (march 2007). nuove ipotesi sulla formazione ... di cineriti pedogenizzate, livelli pomicei e livelli sabbiosi, per lo più riferibili al rimaneggiamento di fall pomicei in ambiente di conoide alluvionale. da 18 m a 21 m sono stati carotati i depositi cineritici e tufacei dell’ignimbrite campana ed, infine, sino a 30 m il substrato flyschoide in facies arenacea. il sondaggio s4 è localizzato circa 35 m a nord dello sprofondamento di contrada petrosa ed ha raggiunto la profondità di 25 m. per i primi 24 m sono state incontrate alternanze di cineriti pomicee, sabbie e sabbie limose, talora legate a prodotti da caduta in posto, e talora rimaneggiate in ambiente alluvionale. tra 24 m e 25 m di profondità è stata rilevata una cinerite in posto contenente molte pomici idiomorfe molto probabilmente da correlare alla parte alta dell’ignimbrite campana. il sondaggio s5 è stato realizzato nella zona centrale del sinkhole sk3 (cfr. fig. 2) ubicato a circa 500 m ad ovest dallo sprofondamento di contrada petrosa ed ha raggiunto i 30 m di profondità. dal piano campagna sino a circa 21 m di profondità sono stati riscontrati terreni di riempimento del sinkhole di natura limoso-argillosa privi di strutture sedimentarie e ricchi in frustoli carboniosi. da 21 m sino a 30 m sono state riscontrate prevalentemente sabbie piroclastiche rimaneggiate in ambiente di conoide alluvionale. il sondaggio s6 è stato effettuato al centro del sinkhole sk2 (cfr. fig. 2) ubicato circa 600 m ad ovest dello sprofondamento di contrada petrosa, ed anch’esso è stato spinto fino a 30 m di profondità. sino a 20 m di profondità sono stati rinvenuti terreni di riporto privi di strutture sedimentarie spesso con notevole presenza di sostanza organica. da 20 a 30 m sono stati riscontrati terreni in posto prevalentemente sabbiosi e limoso-sabbiosi legati a depositi piroclastici rimaneggiati in ambiente alluvionale. il sondaggio s7 è stato eseguito al centro dello sprofondamento di contrada petrosa fino ad una profondità di 51 m dopo aver completamente riempito il sinkhole con circa 3000 m3 di terreno vegetale prelevato da altri scavi realizzati nella piana di forino. il sondaggio, per i primi 15 m eseguito a distruzione, dai 15 a 25 m ha incontrato alternanze di sabbie piroclastiche rimaneggiate crollate dalle pareti del sinkhole. tra 25 e 27 m è stato ritrovato un livello più ricco in sostanza organica nel quale è stato carotato un tronco di nocciolo non carbonizzato a nostro avviso sicuramente legato allo sprofondamento del giugno 2005. fig. 9 dettaglio topografico dell’area di contrada petrosa con l’ubicazione dei sinkhole sk1, sk4, sk7, sk8 e delle perforazioni (s1, s2; s3, s4, s7) . contrada petrosa topographic map with sinkhole (sk1; sk4; sk7 sk8) and borehole (s1, s2; s3, s4 e s7) locations. 402 s. del prete, i. giulivo & a. santo seguono sino a circa 28,50 altri intervalli cineritici pedogenizzati molto probabilmente ancora legati allo sprofondamento del 12 giugno. da 28,50 m a 33 m sono state incontrate sabbie e limi sabbiosi in posto di ambiente alluvionale. da 33 a 50 m è stata perforata l’ignimbrite campana che poggia direttamente sul substrato in facies di flysch carotato per circa 1 m. 5. interpretazione dei dati e ipotesi genetiche dei sinkhole i sondaggi effettuati sui 4 lati dello sprofondamento di contrada petrosa (s1, s2, s3, s4) e quello al centro del sinkhole (s7) insieme ai dati derivanti dalle due perforazioni eseguite in due sinkhole antichi (s5, s6), permettono di proporre un primo chiaro modello stratigrafico del settore del territorio di forino interessato dagli sprofondamenti e di avanzare alcune preliminari considerazioni sulla loro genesi. in tutti i sondaggi è stata osservata la presenza per i primi metri di depositi vulcanoclastici da caduta di natura sabbioso-limosa che passano in profondità, sino a circa 25m, a sabbie e limi di ambiente alluvionale. nei sondaggi eseguiti in vicinanza dello sprofondamento della petrosa (fig. 10) è stata intercettata l’importante eruzione vulcanica dell’ignimbrite campana che si presenta con cineriti e tufi lapidei prevalentemente nella facies gialla con spessore variabile da pochi metri a circa 17 m. in 4 di questi sondaggi è stato intercettato anche il substrato pre-quaternario rappresentato da depositi miocenici di natura arenacea. nessuna delle perforazioni, inoltre, ha intercettato il substrato calcareo. nei due sondaggi eseguiti nei sinkhole antichi di zarra e donna teresa (s6 ed s5; cfr. figg. 2 e 4), sono stati rinvenuti 20 m di terreni di riporto, che poggiano su sabbie e limi alluvionali in posto. i dati stratigrafici ci permettono quindi di escludere la presenza di un vuoto carsico almeno per i primi 52 m di profondità. sembrerebbe che i vuoti ipogei necessari per giustificare le volumetrie delle voragini, si siano formati nei sedimenti sabbioso-limosi posti al top dell’ignimbrite campana come testimoniato anche dal ritrovamento di un tronco di nocciolo durante la perforazione del sondaggio s7 riscontrato a 26 m di profondità e pochi metri al disopra del substrato in posto. le sezioni geologiche realizzate nell’area di contrada petrosa (fig. 10), permettono di ricostruire la successione degli eventi sedimentari; esse infatti evidenziano chiaramente (figg. 10 e 11) un substrato artifig. 10 ricostruzione stratigrafica del sito del sinkhole sk7 in contrada petrosa. 1) materiale di riempimento del sinkhole; 2) materiale da crollo del sinkhole; 3) alternanza di livelli cineritico-pomicei rimaneggiati e livelli pomiceo-scoriacei da caduta; 4) piroclastiti sabbioso limose rimaneggiate, alternate a livelli cineritico pomicei pedogenizzati; 5) cappellaccio dell’ignimbrite campana; 6) ignimbrite campana; 7) flysch miocenici. stratigraphic cross section of sk7 sinkhole at contrada petrosa site. 1) sinkhole artificial filling deposits; 2) rock fall deposits; 3) reworked ash and pumice levels alternated with fall deposits; 4) reworked sandy and silty pyroclastic deposits alternated with pumice and ash levels; 5) cap rock of campanian ignimbrite; 6) campanian ignimbrite; 7) miocenic flysch. 403nuove ipotesi sulla formazione ... fig. 11 evoluzione geomorfologica del sinkhole sk7 di contrada petrosa. a) paleoincisione nel substrato terrigeno (circa 40.000 anni fa); b) deposizione dell’ignimbrite campana (circa 39.000 anni fa); c) erosione dell’ignimbrite campana operata dal nuovo reticolo idrografico (circa 20.000 anni fa); d)fase di riempimento della paleoincisione (tra 20.000 e 10.000 anni fa circa); e) ulteriore fase di aggradazione della piana per caduta di depositi piroclastici che seppellisce definitivamente la paleo-valle. in profondità si creano le condizioni per la circolazione idrica nell’acquifero piroclastico-alluvionale con un deflusso preferenziale che segue la paleoincisione sepolta (post 10.000 anni fa); f) la circolazione idrica sotterranea innesca un lento processo di erosione sotterranea che porta alla formazione di vuoti; g) la lenta evoluzione del vuoto verso l’alto (h) origina un sinkhole. geomorphological evolution of contrada petrosa sinkhole (sk7). a) paleo-gully on flysch bedrock (about 40.000 y. b.p.); b) deposition of the campanian ignimbrite (about 39.000 y. b.p.); c) erosion of the campanian ignimbrite and genesis of a new gully (about 20.000 y. b.p.); d) phase of valley filling (between 20.000 and 10.000 y. b.p.); e) plain aggradation by means of pyroclastic fall deposits. the ancient valley, cut in the campanian ignimbrite formation and filled in with reworked pyroclastic deposits, is now definitely buried (post 10.000 y.b.p.); f) groundwater circulation inside the alluvial-pyroclastic aquifer has a flow direction oriented like the buried paleo-gully and causes a slow erosion (suffosion) producing void formations; g) the upward void migration (h) causes the sinkhole. 404 s. del prete, i. giulivo & a. santo colato e caratterizzato dalla presenza di una paleoincisione sepolta impostata nel substrato miocenico (fig. 11a). questa vallecola sarebbe stata ricolmata durante la deposizione dell’ignimbrite campana (circa 39.000 anni fa; fig. 11b) e nuovamente reincisa dai successivi fenomeni di erosione lineare (fig. 11c). questo dato trova conferma nell’assenza, nel sondaggio s7, dei livelli più alti dell’ignimbrite campana (cappellaccio) presente invece nei settori laterali (sondaggi s1, s2, s3 e s4; cfr. fig. 10). tra 20.000 e 10.000 anni fa si verifica una prima fase di riempimento della paleoincisione per l’apporto di depositi alluvionali nella piana costituiti da piroclastiti rimaneggiate di natura sabbioso-limosa e dilavate dai versanti (eruzione di “sarno”; fig. 11d). più recentemente, negli ultimi 10.000 anni, si hanno altri apporti di materiali piroclastici, talora in giacitura primaria, di origine flegreo-vesuviana (eruzioni di “ottaviano-mercato” e di “avellino”) alternati a paleosuoli e a livelli alluvionali limoso-sabbiosi (fig. 11e). contemporaneamente al riempimento della piana, si instaurarono le condizioni per la formazione di una falda superficiale nell’acquifero piroclastico alluvionale alimentata anche da travasi laterali provenienti dai vicini massicci carbonatici. questa circolazione idrica sotterranea trova nelle paleoincisioni sepolte e colmate da corpi sabbiosi, delle vie preferenziali di deflusso. essa è particolarmente attiva in concomitanza di inverni molto piovosi, e si instaura nel riempimento alluvionale al contatto con substrato impermeabile (ignimbrite campana e flysch miocenici. la direzione di drenaggio è orientata parallelamente al versante di m. romola da wnw verso ese come evidenziato in santo et al., 1998 (cfr. fig. 4). è probabile che in queste condizioni, analogamente a quanto riportato in letteratura per altri contesti (arkin & gilat, 2000), il notevole carico idraulico della falda collegato ad inverni molto piovosi possa creare locali situazioni di erosione sotterranea (soffusione profonda) nei livelli limoso-sabbiosi (fig. 11f e 11g). non è un caso che i sinkhole censiti si allineano nella direzione di drenaggio preferenziale della falda. a tale proposito durante la campagna di indagini tutte le perforazioni sono state condizionate con piezometro a tubo aperto per la misurazione della falda. le misure eseguite dal maggio 2007 a giugno 2008 non hanno rilevato la presenza della falda nel corpo alluvionale e nel substrato. la presenza di acqua talora rilevata ai piezometri è da imputare a ristagni a fondo foro come evidenziato anche dall’assenza di variazioni significative del livello idrico. va ricordato comunque che l’anno 2007 è stato particolarmente siccitoso mentre il livello della falda doveva essere sicuramente più alto nell’inverno 20042005 quando cioè si sono avuti gli sprofondamenti. a tal proposito, in fig. 12 si riportano le piogge cumulate del periodo della ricarica dell’inverno 20042005. si può notare come questo periodo risulta eccezionalmente piovoso se confrontato alla media calcolata tra il periodo 1974-2005. è molto probabile quindi che in concomitanza degli sprofondamenti la falda abbia subito un notevole innalzamento che purtroppo non è stato possibile quantificare per mancanza di indagini e misurazioni nel corso del 2005. si ricorda comunque che testimonianze di locali riportano di risalite di acqua almeno per i sinkhole più antichi. l’assenza della falda fino ad una profondità di otre 50 m dal p.c. evidenziata dalle ripetute misurazioni ai piezometri (intervallo maggio 2007-giugno 2008) evidenzierebbe comunque l’eccezionalità dell’inverno 2005 nel quale la circolazione idrica sotterranea doveva essere molto più attiva e sicuramente con una piezometrica più alta rispetto ai valori normali. le prime ipotesi sulla formazione dei sinkhole fig. 12 precipitazioni medie mensili per il periodo 1974-2005 confrontate con le precipitazioni totali mensili relative agli anni 19961997 e 2004-2005 (stazione pluviometrica del genio civile-avellino; da di crescenzo et al., 2008). mean monthly rainfall refereed to 1974-2005 compared with the total monthly rainfall calculated over the period 1996-1997 and 20042005 (genio civile-avellino rain gauges; from di crescenzo et al., 2008). 405nuove ipotesi sulla formazione ... lascerebbero pensare ad una lenta e graduale erosione nel tempo dei livelli sabbiosi per effetto di una circolazione idrica sotterranea caratterizzata da velocità abbastanza sostenuta e, localmente, con moto turbolento, attiva solo in periodi particolarmente piovosi. la lenta e graduale erosione sotterranea del livello sabbioso potrebbe aver creato una protocavità che si sarebbe evoluta sia lateralmente che verso l’alto fino a raggiungere dimensioni tali da non riuscire a sostenere la volta per gli sforzi di taglio indotti dal carico dei terreni sovrastanti che sono così collassati (fig. 11g e 11h). sulla base di questa ipotesi genetica, rimarrebbe tuttavia da chiarire l’eventuale recapito finale del materiale eroso. una ipotesi, tutta da dimostrare, potrebbe essere quella della presenza di un paleo inghiottitoio sepolto presumibilmente localizzato in corrispondenza del sinkhole sk5 ubicato in prossimità dei calcari del bordo sud orientale della conca endoreica dove già esistono in superficie analoghe morfologie carsiche (fig. 13). l’inghiottitoio sepolto potrebbe contribuire allo “smaltimento” del carico solido eroso per fenomeni di deep piping nelle aree più a monte. 6. discussione e conclusioni il problema della genesi dei sinkhole in aree alluvionali è ancora molto discusso. secondo diversi autori (tharp, 1997, 1999; nisio, 2003; nisio & salvati, 2004) i fenomeni di piping sinkhole, in aree alluvionali sarebbero generalmente da ricondurre alla presenza di cavità in rocce solubili all’interno di un substrato carsificabile che richiamerebbe il materiale di copertura fino ad avere un collasso improvviso in superficie. il “motore” di questo processo viene spesso individuato nell’azione di flussi verticali risalenti lungo zone fratturate o piani di faglia. altri autori, invece, popongono modelli diversi che escludono la presenza di un substrato carsificabile (hoffman et al., 1998; arkin & gilat, 2000; tomlinson & vaid, 2000) dimostrando che i vuoti responsabili del collasso si possono formare anche in terreni granulari per fenomeni di suffosione profonda. tale processo consiste nell’erosione meccanica di un terreno poroso per effetto dello scorrimento (subsuperficiale secondo la definizione originaria di castiglioni, 1986) dell’acqua in pressione che trova delle vie di scorrimento in cui passare con elevata velocità e moto turbolento. questo passaggio, provocando l’erosione del terreno, dà origine a canalicoli a sviluppo sub-orizzontale, condotti tubolari o cavità lungo le linee di flusso. analoghi fenomeni sono segnalati anche lungo il perimetro del mar morto e nella piana del fiume santa cruz a tucson in arizona (hoffman et al; 1998; arkin & gilat, 2000) dove la variazione da flussi laminari a turbolenti in zone discrete lungo il percorso delle linee di flusso in subalveo, causa il dilavamento dei materiali a granulometria sottile e la formazione di vuoti sotterranei. nel caso dei sinkhole di forino le indagini svolte confermano che i vuoti responsabili dei collassi si sono formati nei depositi di copertura limo-sabbiosi per fenomeni di suffosione profonda a profondità variabili tra i 20 ed i 25m ed in assenza di un bedrock carsificabile. i vuoti si creerebbero lentamente a causa dell’erosione meccanica operata da flussi turbolenti che asporterebbero i terreni a granulometria più sottile in particolari condizioni di notevole ricarica della falda. il fenomeno si instaura all’interfaccia tra terreni meno permeabili (flysch e tufi) ed i soprastanti terreni alluvionali sabbioso-limosi (fig. 13). successivamente il vuoto migrerebbe lentamente verso l’alto fino ad intercettare la superficie topografica e generare il collasso finale (fig. 11 e 13). si esclude quindi l’ipotesi della presenza e dell’influenza di eventuali cavità nel substrato carbonatico e anche quella di flussi profondi risalenti lungo faglie di cui, peraltro, non c’è nessuna evidenza superficiale. il contributo dei calcari e del carsismo in generale, sarebbe fondamentale invece per la veloce ricarica e l’aumento del carico idraulico nella falda multistrato dell’acquifero alluvionale (fig. 13). il substrato carsificato, inoltre, potrebbe spiegare fig. 13 rappresentazione schematica della formazione dei sinkhole nella piana di forino. 1) depositi piroclastici da fall alternati a paleosuoli e livelli alluvionali; 2) piroclastiti rimaneggiate in ambiente alluvionale; 3) ignimbrite campana; 4) detrito di versante; 5) depositi limoso-sabbiosi pre ignimbrite campana; 6) flysch miocenici; 7) substrato carbonatico mesozoico; 8) faglia; 9) sorgente; 10) circolazione idrica sotterranea nell’acquifero alluvionale. schematic representation of sinkhole formation in the forino plain. legend: 1) pyroclastic fall deposits, paleosoils alternated with alluvial deposits; 2) alluvial deposits; 3) campanian ignimbrite; 4) detritical talus; 5)alluvial sandy and silty deposits pre-campanian ignimbrite; 6) miocenic flysch; 7) mesozoic limestones; 8) fault; 9) spring; 10) underground water circulation inside alluvial aquifer. 406 s. del prete, i. giulivo & a. santo la scomparsa dei notevoli volumi di terreni asportati (poche migliaia di m3). infatti, lungo il bordo sud orientale della conca e laddove i calcari vengono a contatto diretto con l’acquifero piroclastico alluvionale, si potrebbe avere lo smaltimento di parte delle acque dell’acquifero alluvionale e del trasporto solido verso la falda profonda attraverso inghiottitoi sepolti (fig. 13). per quanto detto precedentemente non si esclude che nel sottosuolo della piana di forino siano presenti altri vuoti, non ancora noti perché profondi o perché non hanno ancora raggiunto la superficie topografica. in prima approssimazione, sulla scorta del censimento dei sinkhole effettuato e dell’assetto stratigrafico ed idrogeologico della piana di forino, la fascia di territorio che è da ritenere più suscettibile all’innesco di nuovi sprofondamenti si allinea in corrispondenza della zona di drenaggio preferenziale della falda dell’acquifero piroclastico alluvionale. tuttavia una zonazione più precisa su un territorio così vasto non potrà che essere realizzata a valle di ulteriori indagini e soprattutto attraverso la definizione dello schema idrogeologico locale ed il monitoraggio della falda nell’acquifero alluvionale. è da sottolineare, infine, che il modello qui proposto rappresenta solo uno dei possibili meccanismi di innesco di sinkhole in are alluvionali, in altri contesti ed in condizioni stratigrafiche ed idrogeologiche diverse non si escludono effetti della carsificazione in rocce solubili e, soprattutto, fenomeni di improvvisa liquefazione di corpi limoso-sabbiosi saturi il cui studio non può prescindere da un approccio anche di tipo geotecnico. bibliografia aa.vv. (2000) le voragini catastrofiche un nuovo problema per la toscana. atti del convegno organizzato dalla regione toscana, provincia e comune di grosseto, grosseto, 31 marzo 2000, 256 pp. aa.vv. (2004) stato dell’arte sullo studio dei fenomeni di sinkholes e ruolo delle amministrazioni statali e locali nel governo del territorio. atti del convegno organizzato dall’apat, roma, 20-21 maggio 2004, 709 pp. arkin y., gilat a. (2000) dead sea sinkholes – an ever-developing hazard. environmental geology, 39 (7), pp. 711-722. berti g., canuti p., casagli n., pranzini g., micheli l. (2000) risultati preliminari delle indagini sullo sprofondamento in loc. bottegone (grosseto). atti del convegno “le voragini catastrofiche un nuovo problema per la toscana”, 31 marzo 2000, regione toscana, provincia e comune di grosseto, grosseto, pp. 242-256. capelli g., petitta m., salvati r. (2000) relationships between catastrophic subsidence hazards and groundwater in the velino valley (central italy). proc. vi int. symp. on land subsidence sisols 2000, ravenna, italy, pp. 123-136. capelli g., delitala m. c., primavera p., salvati r., taddeucci a., tuccimei p. (2004) lo studio degli “spring-sinkhole” del gruppo dei laghi del vescovo (pianura pontina) attraverso l’uso del “radon budget”. atti conv. “stato dell’arte sullo studio dei fenomeni di sinkhole e ruolo delle amministrazioni statali e locali nel governo del territorio”, 20-21 maggio 2004, apat, roma, pp. 189-199. castiglioni g.b. (1986) geomorfologia. utet, 436 pp. celico p. (1979) schema idrogeologico dell’appennino carbonatico centro-meridionale. mem. e note ist. di geol. appl. univ. di napoli, 14, 19781979, 97 pp. ciotoli g., di filippo m., nisio s., romagnoli c. (2001) la piana di s. vittorino: dati preliminari sugli studi geologici, strutturali, geomorfologici, geofisici e biochimici mem. soc. geol. it, 56, pp. 297-308. civita m., de riso r., nicotera p. (1970) sulla struttura idrogeologica alimentante le sorgenti del fiume sarno e le falde pedemontane profonde della parte sud-orientale della conca campana. conv. int. sulle acque sotterranee, palermo, 6-8 dicembre 1970, 24 pp. closson d. (2004)structural control of sinkholes and subsidence hazards along the jordanian dead sea coast. environmental geology, 47, pp. 290301. cozzolino l., pianese n., santangelo n., santo a. (2007) sinkhole di origine carsica nell’area dei monti lattari. atti i conv. regionale di speleologia “campania speleologica”, 1-3 giugno 2007, oliveto citra (sa), federazione speleologica campana, pp. 85-101. de vivo b., rolandi g., gans p. b., calvert a., bohrson w. a., spera f. j., belkin h. e. (2001) new constraints on the pyroclastic eruptive history of campanian volcanic plain (italy). mineralogy and petrology, 73, pp. 47-65. di crescenzo g., rotella m., santo a. (2007) le frane da scorrimento-colata rapida in terreni piroclastici dei contesti in flysch dell’entroterra campano. convegno dei giovani ricercatori di geologia applicata. giornale di geologia applicata, rivista aiga, in stampa. di vito m.a., isaia r., orsi g., southon j., de vita s., d’antonio m., pappalardo l., piochi m. (1999) volcanism and deformation since 12,000 years at the campi flegrei caldera (italy). in: orsi g., civetta l., valentie g. a., (eds.), volcanism in the campi flegrei. jour. of volc and geoth res, 91, pp 221-246. del prete s., de riso r., santo a. (2004) primo contributo sui sinkhole di origine naturale in campania. atti conv. “stato dell’arte sullo studio dei fenomeni di sinkhole e ruolo delle amministrazioni statali e locali nel governo del territorio”, 20-21 maggio 2004, apat, roma, pp. 361-376. del prete s., santo a. (2005) i sinkhole di origine carsica in campania. in russo n., del prete s., giulivo i., santo a. editors: grotte e speleologia della campania. sellino ed., pp. 36-37. facenna c., florindo f., funicello r., lombardi s. (1993) tectonic setting and sinkhole features: case histories from western central italy . quaternary proceeding, 3, pp. 47-56. ferrelli l., guerrieri l., nisio s., vita l., vittori e. (2004) relations among seismogenetic structures, earthquakes and sinkhole phenomena: a 407nuove ipotesi sulla formazione ... methodological approach in the appennines (italy). 32 int. geol. congr., firenze 20-28 agosto 2004. gutiérrez f. (2004) el riesgo de dolinas de subsidencia en terrenos evaporiticos. investigación y mitigatión. atti conv. “stato dell’arte sullo studio dei fenomeni di sinkhole e ruolo delle amministrazioni statali e locali nel governo del territorio”, 20-21 maggio 2004, apat, roma, pp. 453-466. hoffman j.p., pool d.r., kowieczki a.d., carpenter m.c. (1998) causes of sinks near tucson arizona, usa. hydro jour., 6, pp. 349-364. nisio s. (2003) i fenomeni di sprofondamento: stato delle conoscenze ed alcuni esempi in italia centrale. il quaternario, 16 (1), pp. 121-132. nisio s., salvati r. (2004) fenomeni di sprofondamento catastrofico. proposta di classificazione applicata alla casistica italiana. atti conv. “stato dell’arte sullo studio dei fenomeni di sinkhole e ruolo delle amministrazioni statali e locali nel governo del territorio”, 20-21 maggio 2004, apat, roma, pp. 573-583. nisio s., scapola f. (2005) individuazione di aree a rischio sinkhole: nuovi casi di studio nel lazio meridionale. il quaternario, 18 (2), pp. 223-239. nisio s., graciotti r., vita l. (2004) i fenomeni di sinkhole in italia: terminologia, meccanismi genetici e problematiche aperte. atti conv. “stato dell’arte sullo studio dei fenomeni di sinkhole e ruolo delle amministrazioni statali e locali nel governo del territorio”, 20-21 maggio 2004, apat, roma, pp. 557-571. rolandi g., maraffi s., petrosino p. & lirer l. (1993) the ottaviano eruption of somma-vesuvius (8000 y b.p.): a magmatic alternating fall and flow-forming eruption. journ. volcan. and geoth. reser., 58, 43-65. rolandi g. (1997) the eruptive history of sommavesuvius volcanism and archeology in mediterranean area. ed. de vivo & cortini. santo a., liguori m., aquino s., galasso m. (1998) problemi di geologia ambientale nei polje appenninici: l’esempio della piana di forino (campania). il quaternario, 11(2), pp. 233-245. santo a., del prete s., di crescenzo g., rotella m. (2007) karst processes and slope instability: some investigations in the carbonate apennine of campania (southern italy). general assembly of european geosciences assembly, vienna 24-29 aprile 2005, geological society, london, special publications from parise, m. & gunn, j. (eds) natural and anthropogenic hazards in karst: recognition, analysis and mitigation, 279, pp. 5972. sinclair w.c., stewart j.w. (1985) sinkhole type, development and distribution in florida. us geological survey, florida department of natural resources, bureau of geology map series, ms110, 1 plate. tharp t.m. (1997) mechanism of formation of cover collapse sinkhole. proc. 6th multidisciplinary conference of sinkhole and the engineering and environmental impact of karst, pp. 29–36, balkema, rotterdam tharp t.m. (1999) mechanism of upward propagation of cover collapse sinkhole. engineering geology, 52, pp. 23-33. tomlinson s.s., vaid y.p. (2000) seepage forces and confining pressure effects on piping erosion. canadian geotechnical jour., 37, pp. 1-13. waltham t., bell f., culshaw m. (2005) sinkholes and subsidence. springer, 382 pp. ms. ricevuto il 12 marzo 2008 testo definitivo ricevuto il 17 giugno 2008 ms. received: march 12, 2008 final text received: june 17, 2008 408 s. del prete, i. giulivo & a. santo amq abs vigliotti ruberti tepro 247-251.pub available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 247 251 campania grey tuff and anthropogenic tuff cavites in the southern metropolitan area of caserta (southern italy) marco vigliotti, daniela ruberti engineering department, campania university "l. vanvitelli"; aversa (ce), italy corresponding author: d. ruberti <daniela.ruberti@unicampania.it> abstract: the late quaternary geological evolution of the northern campania plain was affected by the volcanic activity of the phlegrean field. the geological features of the campania grey tuff (cgt, ~39 ky), deposited on the whole campania plain, were reconstructed along a transect from the northern boundary of the metropolitan area of naples up to caserta. since the tuff has good mechanical properties, it was involved since historical times in an extensive mining activity, from which a very dense network of quarries and underground cavities was inherited, strongly related to the lithofacies distribution. we provided a first geological underground database of the metropolitan area of caserta, north of naples, and analyzed the hazard aspects related to the mining activities. keywords: campania plain, campania grey tuff, urban data management, database, tuff cavity 1. introduction the late quaternary geological evolution of the northern campania plain has been affected by the volcanic activity of the phlegrean field. among the volcanic events that have characterized this area, the one that emplaced the campanian grey tuff (~39 ky; de vivo et al., 2001) was the most important. thick pyroclastic flow deposits blanketed the whole plain and represented the substrate for the following holocene sedimentation, with thicknesses of tens of metres and a depth from the ground level reducing toward north-east, close to the apennines foothills (ortolani & aprile, 1985; bellucci, 1994; putignano et al., 2007; ruberti et al., 2014). the campanian grey tuff shows different lithofacies both laterally and with depth (di girolamo, 1968; cappelletti et al., 2003; ruberti et al., 2014). since the tuff has good mechanical properties, it was involved since historical times in an extensive mining activity, from which a very dense network of quarries and underground cavities was inherited, strongly related to the lithofacies distribution. in many urban centers of the campania plain (e.g., naples, aversa and surroundings), cavities have been reported in specific geological investigations although their real extent is almost unknown. in these towns the underground mining activities were performed to extract tuffs for buildings. the urban development has sealed every signal of the presence of cavities, which thus represent a geological hazard and contribute to subsoil instability in many places (brinkmann et al., 2008; parise, 2010; scotto di santolo et al., 2018). in a correct urban management, the knowledge of the city subsoil is a priority, as the presence of cavities may easily trigger the collapse of the shallow or deeper soils (e.g., ciotoli et al., 2015; guarino et al., 2017). it is herein reported a preliminary study carried out on the small area of the campania plain, north of naples, along a transect from the northern boundary of the naples municipality to caserta. the study area is characterized by a flat topography and was interested by the volcanic activity of the phlegrean field. tuffs and cinerites are the main lithologies recognized in the first tens of metres. since the tuffs have good mechanical properties (i.e. high compression strength, low specific weight) and are found at a shallow depth from ground level, they were involved since historical times in an extensive underground mining activity. towards the apen fig. 1 geological map of the study area (modified from ruberti et al., 2014). yellow lines indicate the geological profiles in fig. 2. https://doi.org/10.26382/aiqua.2018.aiquaconference nines the tuff lies only a few metres below the ground level. this resulted in a strong development of quarrying through open pits (ruberti et al., 2014). the present investigation tries to address the complex interaction between geological framework and anthropic activities related to urban subsoil of the metropolitan area of caserta, north of naples; data were managed in a gis so as to provide a first geological underground database and a preliminary analysis of the hazard aspects related to the mining activities. 2. study area the examined area, about 54 km2 wide, corresponds to the central part of the campania plain (fig. 1), north-east of the phlegrean fields, that is characterized by a flat morphology between 95 and 20 m a.s.l. in this area the subsoil is formed by the succession of different units composed of volcanoclastic deposits, in particular related to the campania grey tuff (cgt; 39 ky b.p; de vivo et al., 2001) and neapolitan yellow tuff (nyt; 15 ky b.p.; deino et al., 2004) pyroclastic eruptions. the cgt deposits were settled on the whole campania plain, giving rise to a thick (up to 40 m), laterally continuous, volcanoclastic unit. different lithofacies can be recognized within the cgt mostly basing on the different mineralogic composition (di girolamo 1968; cappelletti et al., 2003; morra et al., 2010). on the whole, from top to bottom the succession of cgt lithofacies is characterized by an upper incoherent part, represented by the cinerazzo (cz) followed by the coherent zeolitic yellow tuff (tgz) and/or grey tuff (tg), piperno tuff (tp), and pipernoide (pp) ones. close to the bottom of the unit, a soft lithofacies occurs, called cinerite (cn). these lithofacies greatly vary in thickness and occurrence vertically and laterally toward east or north from the source area. the uppermost unit of the reconstructed stratigraphic succession is represented by the thin grey, loose ashy deposits of the nyt, which are locally separated from underlying cgt by a paleosol (putignano et al., 2007; santangelo et al., 2010; ruberti et al., 2014). the good mechanical characteristics of the tuff lithofacies justify the presence of numerous quarries and/or cavities, according to the availability of adequate thicknesses of coherent lithofacies (i.e. tgz, tg). 3. methods the main geologic features of the study area were obtained using lithostratigraphic logs from boreholes 248 fig. 2 geological cross-sections (tracks in fig. 1): (1) cinerite,(2) grey tuff, (3) zeolitic yellow tuff, (4) pebble tuff, (5) incoherent facies of cgt, (6) paleosoil, (7) pyroclastic deposits younger than cgt, (8) soil, (9) pre-cgt deposits. quarries and cavities are not to scale. dotted line indicates the upper and lower limits of the cgt deposits. vigliotti m., ruberti d. 249 reaching the depth of 30–35 m, available from different sources (environmental agencies, municipality offices, professional studies, unpublished researches, etc.), and from the analysis of quarry walls (in the northern part of the study area) exposing 15–20 m of deposits. the marker key to correlate the different units was represented by the cgt volcaniclastic deposits. the lithological data were collected into a relational geodatabase of well-log stratigraphies, which were further interpreted and homogenized in terms of lithologic units, also containing the related thickness and upper and lower-boundary elevations a.s.l, with the aim of facilitating the development of a 3d geological model (putignano et al., 2007; see also methods in velasco et al., 2012). previous studies have highlighted the presence in the area of numerous cavities. in a first step, a database was elaborated to organize previous data and the results of new, specific investigations. a gis project was designed to manage the georeferenced database and plot the cavity distribution on the numerical cartography in 1:5000 scale. many cavity maps were digitized, georeferenced and imported in the gis environment. in such way, they can be easily located under the built areas. where plan views were not available, the cavities and/or the access wells were reported only as points. the shallow quarries have been located through interpretation of aerial multitemporal photos and analysis of historical cartography (see also ruberti et al., 2014). 4. results and discussion the analysis of geological data has revealed some common features for the considered area (fig. 2): i) the occurrence of coherent zeolitic yellow tuff was the main trigger for cavity development, mainly for extraction purpose; mean thickness is 8 m. the zeolitized yellow welded tuff is formed by ashy matrix with rounded lapilli and dispersed block pumice clasts. locally, few and scattered coarse scoriae are present; ii) below the zeolitic yellow tuff, slightly welded pyroclastic soils and ash layers occur showing different compaction. iii) in the slightly lithified upper part ash is characterized by abundant pebbles/breccias of volcanic tuff (cappellaccio or pebble tuff); iv) a metre thick paleosoil underlines the upper limit of the cgt. the former is formed by brown, silty-sand, pyroclastic unit with small rounded and altered pumices. the upper deposits mainly consist of whiteyellowish and greyish cinerite in which whitish pumfig. 3 example of cave dug into the tuff. a) view of a chamber with an access well on top; b) details of access realized with steps directly carved into the tuff. campania grey tuff and cavities ice layers intercalate, mostly related to more recent eruptions of the phlegrean fields. towards east the thickness is reduced to a few metres (about 2 m). on the whole, the development of artificial cavities and quarries was strongly linked to the lithology of the cgt and the related thickness. in the southern part of the study area a dense cavity network characterizes most of the historical town centers whereas towards east the cavities are associated with and/or replaced by open pits developing for almost 10-15 m down from the surface. the cavities develop within the yellow tuff in which large scoriae, pumices and lava blocks can be recognized. pipes are common and very often the weak, loosely packed deposits favoured the beginning of the quarring activity (fig. 3). the digging of cavities initially involved an excavation carried out as a "bottle" or a "bell" from the ground level down to the tuff unit, developing at depth according to its thickness. during excavation, access points were realized (fig. 3a) through the poorly lithified or loose deposits, with a square or pseudo-circular cross-section; sometimes they were supported by containment walls made of tuff bricks resting on the lower lithoid tufaceous bank. a single vertical excavation is sometimes added at certain distance, so as to determine in depth the coalescence of several chambers, also through the construction of narrow tunnels or wide passages. access shafts were often realized with a system of stairs with one or more ramps, with steps directly carved into the tuff (fig. 3b). eastwards, the reduced thickness of the post-cgt deposits allowed the easy mining of tuff in open pits from the ground surface. all the quarries are almost similar: they are rectangular holes about 1–4 hectares large with almost 20-m high, vertical steep walls. a previous study (ruberti et al., 2014) has highlighted that most of these quarries are nowadays partially filled with earthy materials and used for agricultural purposes, whereas others are sites of illegal waste disposal; some of them lie buried in the present urban area. the mining activities were responsible for the reduction, up to the complete removal, of the yellow tuff. moreover, the tuff mining resulted in the reduction of the depth of the quarry bottom in respect to groundwater, leading to a further critical environmental condition. 5. concluding remarks the study provides a first database of the geological underground in the metropolitan area of caserta, north of naples. the database is designed to be managed into a gis environment in order to provide a detailed 3d geological reconstruction. the gis project was implemented with data on tuff cavities and quarries from the same area. quarrying for building materials was the main trigger for cavity development in the historical center of the towns and their occurrence is linked to the availability of underground well-lithified materials. the analysis of the urban expansion since the beginning of the 19th century has revealed a close relationship between the occurrence of cavities in the subsoil and the expansion of the city until the 1970s, when the use of cement completely replaced 250 fig. 4 a quarry pit showing typical vertical walls, partially filled for agricultural purpose. vigliotti m., ruberti d. the extraction of tuff. the knowledge of such underground system represents a useful contribution to the hazard evaluation in densely urbanized areas. on the other hand, the recognition of the open pits for tuff extraction and the assessment of their current use provides information for land management and allows the assessment of possible pollution hazard. references bellucci f. (1994) nuove conoscenze stratigrafiche sui depositi vulcanici del sottosuolo del settore meridionale della piana campana. boll. soc. geol. it., 113, 395-420. brinkmann r., parise m., dye d. (2008) sinkhole distribution in a rapidly developing urban environment: hillsborough county, tampa bay area, florida. eng. geol. 99 (3-4), 169-184. cappelletti p., cerri g., colella a., de’ gennaro m., langella a., perrotta a., scarpati c. (2003) posteruptive processes in the campanian ignimbrite. miner. petrol., 79, 79-97. ciotoli g., ferri g., nisio s., succhiarelli c. (2015) the underground cavities in the territory of rome: typologies, distribution and sinkhole susceptibility. in: hypogea 2015, proceedings of international congress of speleology and artificial cavities rome, march11/17 2015, 433-439. de vivo b., rolandi g., gaus p.b., calvert a., bohrson w.a., spere f.j., belkin h.e. (2001) new constraints on the pyroclastic eruptive history of the campanian volcanic plain (italy). miner. petrol., 73, 47-65. deino a.l., orsi g., de vita s., piochi m. (2004) the age of the neapolitan yellow tuff caldera-forming eruption (campi flegrei caldera-italy) assessed by 40ar/39ar dating metod. j. volcanol. geotherm. res., 133, 157-170. di girolamo p. (1968) petrografia dei tufi campani: il processo di pipernizzazione (tufo tufo pipernoide piperno). rend. accad. sci. fis. mat., ser. 4, 35, 329-394. guarino p., santo a., forte g., de falco m., niceforo m. (2017) analysis of a database for anthropogenic sinkhole triggering and zonation in the naples hinterland (southern italy). natural hazards, 91, 173-192. morra v., calcaterra d., cappelletti p., colella a., fedele l., de’ gennaro r., langella a., de’ gennaro m., mercurio m. (2010) urban geology: relationships between geological setting and architectural heritage of the neapolitan area. in: beltrando m., peccerillo a., mattei m., conticelli s., doglioni c. (eds), the geology of italy: tectonics and life along plate margins. j. virtual explor., electron ed, 36, paper 27. ortolani f., aprile f. (1985) principali caratteristiche stratigrafiche e strutturali dei depositi superficiali della piana campana. boll. soc. geol. it., 104, 195 -206. parise m. (2010) hazards in karst. in: sustain. karst environ. dinaric karst other karst reg. series on groundwater. ihp-unesco, plitvice lakes, croatia, 155-162. parise m., galeazzi c., bixio r., dixon r. (2013) classification of artificial cavities: a first contribution by the uis commission. in: filippi, m. and bosak, p. (eds), proc. 16th int. congr. speleol., 21-28 july 2013, 2, 230-235. putignano m.l., ruberti d., tescione m., vigliotti m. (2007) evoluzione tardo quaternaria del margine casertano della piana campana (italia meridionale). boll. soc. geol. ital., 126 (1), 11-24. ruberti d., vigliotti m., marzaioli r., pacifico a., ermice a. (2014) stratigraphic architecture and anthropic impacts on subsoil to assess the intrinsic potential vulnerability of groundwater: the northeastern campania plain case study, southern italy. environ. earth sci., 71, 319-339. santangelo n., ciampo g., di donato v., esposiro p., petrosino p., romano p., russo ermolli e., santo a., toscano f., villa i. (2010) late quaternary buried lagoons in the northern campania plain (southern italy): evolution of a coastal system under the influence of volcano-tectonics and eustatism. ital. j. geosci. (boll.soc.geol.it.), 129(1), 156 -175. scotto di santolo a., forte g., santo a. (2018) analysis of sinkhole triggering mechanisms in the hinterland of naples (southern italy). engineering geology, 237, 42-52. velasco v., gogu r., va´zquez-sune` e., garriga a., ramos e., riera j., alcaraz m. (2012) the use of gis-based 3d geological tools to improve hydrogeological models of sedimentary media in an urban environment. environ. earth sci., 68 (8), 2145-2162. 251 campania grey tuff and cavities ms. received: may 8, 2018 final text received: may 24, 2018 252 microsoft word 10_negri et al_lm04.doc available online http:/amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 26 (1), 2013, ììì-v a report on the informal meeting “notizie dal fronte” (news from the “fronte”) held at the department of earth sciences in bologna may 7, 2012 alessandra negri1, gian battista vai2, alessandro amorosi3, fabrizio antonioli4, adele bertini5, stefano marabini6, giuseppe mastronuzzi7 1 dipartimento di scienze della vita e dell’ambiente, università politecnica delle marche, ancona, italy 2 museo geologico g. capellini, università degli studi di bologna, bologna, italy 3 dipartimento di scienze biologiche, geologiche e ambientali, università di bologna, bologna, italy 4 enea casaccia, rome, italy 5 dipartimento di scienze della terra, università firenze, italy 6 via san martino 1 faenza, italy 7 dipartimento di scienze della terra e geoambientali, università di bari, italy corresponding author : a. negri <a.negri@univpm.it> abstract: here we shortly report the result of an informal meeting held in bologna under the auspices of aiqua to promote the study of an italian section near taranto (italy) showing interesting features and potentially useful as upper pleistocene gssp. keywords: tyrrhenian, late pleistocene, italy. fig. 1 location of the “fronte” section. negri a. et al. iv on may 7, 2012 the associazione italiana per lo studio del quaternario (aiqua) and the commissione italiana di stratigrafia (cis), in coincidence with the assembly of members and the consiglio di presidenza aiqua, organized an informal meeting with the coordinators of the working group on the fronte section (taranto) (fig 1,2) to discuss and verify the real potential of the section in the frame of the definition of the gssp of the middle/upper pleistocene ( see for a preliminary description of this section antonioli et al, 2008). after a short introduction by the president of aiqua (paolo mozzi) and the president of the commissione italiana di stratigrafia (marco balini), several talks dealing with different geological and stratigraphical aspects have been presented by the actors involved in the study. presentations discussed the potential of the fronte section as gssp for the late pleistocene by the use of different approaches. the principal aim was to show the recent developments of the ongoing research on this locality as well as to discuss problems and to compare opinions with specialists from different fields ut with direct experience at local/regional scale. the first talk was dealing with the geological and geomorphological context of the taranto area (g. mastronuzzi). afterward, f. antonioli, clarified the sea level context during the sediment deposition. passing to the ongoing study of the section, a. negri recalled the story of the study and the main stratigraphical features of the section. to this presentation, it followed as a key study, that of a. amorosi, dealing with the correlation to the section to the po plain drillsites, which fig. 2 the “fronte” section from the sea. fig. fig. 3 a. bertini, g.b vai and s. marabini sampling the “galeso” lacustrine-marine section (taranto, italy). news from the “fronte” v show continuous and thick sedimentary successions encompassing the last 125 kyr. the last contribution was by a. bertini showing the results of a pilot palynological study involving both pollen and dinocysts which open new perspectives for the research. the workshop was attended by about 40 participants, including nannofossil and forams micropaleontologists, palynologists, sedimentologists, sequence stratigraphers, isotope chemistry specialists, tephrocrhonology specialists, geomorphologists, vertebrate paleontologists. one hour and half was dedicated to the presentation of the ongoing research and one hour and half was dedicated to the discussion focused on the doubt and the question posed by the scientific community on the different aspect of the data and the real correlability potential of the “il fronte” section at local/regional scale. the initiative was really successful and based on the suggestion received two members of the working group on the “il fronte” section (a. negri and a. amorosi) presented the achieved results at the 34 igc in brisbane (august 2012), in the session dedicated to gssp, theme 35 geostandards. the presentations have been appreciated and we had a long talk with martin head who has been positively impressed in particular by the new data. a new sampling of the fronte section and the accessory galeso section have been then performed in early september (fig 3,4). processing of the new samples have already started and we are confident to have results ready to be published for the current year 2013. recently (february, 2013) we received an invitation to present our result at the incoming strati 2013 congress to be held in lisbon july 1-7, 2013 in the frame of the session “the quaternary system and its formal subdivision”, conveners martin head (can) / philip gibbard (uk) and thijs van kolfschoten (n). references antonioli f., deino a., ferranti l., keller j., marabini s., mastronuzzi g., negri a., piva a., vai g.b., vigliotti l. (2008) lo studio della sezione “il fronte” per la definizione del piano tarentiano (puglia, italy). il quaternario italian journal of quaternary sciences 21(1a), 35-38. ms. received: march 15, 2013 final text received: march 18, 2013 fig. 4 g. mastronuzzi digging a deep trench for sampling the upper part of the “fronte” section (taranto, italy). << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /all /binding /left /calgrayprofile (gray gamma 2.2) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /warning /compatibilitylevel 1.4 /compressobjects /tags /compresspages true /convertimagestoindexed true /passthroughjpegimages true /createjobticket false /defaultrenderingintent /default /detectblends true /detectcurves 0.1000 /colorconversionstrategy /leavecolorunchanged /dothumbnails false /embedallfonts true /embedopentype false 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documenti pdf creati possono essere aperti con acrobat e adobe reader 5.0 e versioni successive.) /enu (use these settings to create adobe pdf documents suitable for reliable viewing and printing of business documents. created pdf documents can be opened with acrobat and adobe reader 5.0 and later.) >> >> setdistillerparams << /hwresolution [1200 1200] /pagesize [396.850 566.929] >> setpagedevice amq30(1) 1 monaco scozzafava 2.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 30 (1), 2017, 5 10 a preliminary survey for testing operativity and efficiency of gpr technology by means of unshielded antenna for the study of calderone glacier, central italy angelo monaco 1, marco scozzafava 2 1 studio di geologia, avezzano, italy 2 mcubo engineering, l’aquila, italy corresponding author: a. monaco <angelo.monaco@geologiabruzzo.org > abstract: during july 2015 a survey using gpr technology was carried out over the calderone glacier in the gran sasso d’italia massif (highest peak 2912 m a.s.l.). the main aim of the survey was to verify the usability of bistatic unshielded antenna, uncoupled with the ground, and to assess gpr data quality vs reached depth. the use of this kind of antenna is suggested by the need to operate also over rough and irregular surfaces. the obtained results are to be considered very good, as they easily match with previous results obtained in 1992 and 1998 using gpr technology with a shielded antenna, coupled with ground. the interpretation of data highlights a good stability of the ice mass in the lowermiddle sector of the glacier, and a maximum ice thickness evaluated about 26 m. the choose system was a radsys gpr with unshielded antenna of 150 mhz frequency, to cross an ice thickness lower than 30 m, as supposed by previous researches. keywords: gpr, calderone, glacier, uncoupled antenna, apennine, italy. 1. introduction as well known, the calderone glacier, located in a cirque in the north side of corno grande, gran sasso massif (central italy), is the only glacier of apennine and the southernmost of europe (pecci et al., 1997). as a consequence of the raising air temperature in recent decades, it has undergone a progressive and constant melting (gellatly et al., 1994). numerous studies (e.g., marinelli & ricci, 1916; tonini, 1961; smiraglia & veggetti, 1992) have been conducted to define the glacier geometry and the evolution of the glacial apparatus. they all agree in indicating the presence of an icy mass, of not uniquely defined geometry, covered by a not uniform layer of heterometric debris (fig. 1). the estimated maximum thickness was about 26 m (fiucci et al., 1997; de sisti et al., 1998). in view of the logistical difficulties and peculiarities of the survey site, the gpr (better known in literature as ground penetrating radar) has proved to be the most suitable instrument for the deep analysis of the glacier body (bogorodskiy et al., 1985; funk et al., 1993; haeberly et al., 1983), thanks to the progressive reduction of the overall dimensions of the equipment and to its great resolution power and data processing capabilities. to fiucci and collaborators is due the first campaign of investigations by gpr technique performed in the summer of 1992; de sisti et al. (1998) conducted a similar survey in july 1998. this report presents the results of a preliminary gpr survey performed on 26 july 2015 on the lowermiddle sector of the glacier. the survey was carried out quickly with an unshielded antenna, uncoupled with the ground, which has large footprint but anyway a low weight making it possible to extend the acquisition profiles to rough zones, such as the edges of the glacier covered by seasonal snow (fig. 2). the aim of the survey was to verify the effective operativity in such surface conditions, as well as the quality of the results obtained without adherence between antenna and ground, which usually leads to signal attenuation. 2. devices and method the principle which drives a gpr equipment can be summarized as follows: from the ground surface the antenna transmits a pulse-type signal (electromagnetic wave). intercepting an electromagnetic discontinuity in the crossed medium (caused by an object embedded in it or by a change of the medium itself), part of the incident wave is reflected toward the ground surface; the reflected wave is acquired by a receiving antenna at the ground surface. transmission and reflection of electromagnetic waves are driven by the following electromagnetic parameters: relative dielectric constant, generally indicated more briefly with the term "permittivity", that has the most influence on the waves speed; conductivity, a parameter that limits the investigation depth, since the greater the conductivity the greater is the absorption. during signal acquisition, the gpr registers the travel time of the reflected wave, and subsequently converts it into distance covered by the wave, as a function 6 monaco a. & scozzafava m. fig.1 – a sw view of the calderone glacier. on the right the front moraine can be seen. fig.2 the used gpr system: unshielded antenna and acquisition unit. firn covers debris (t1 scan). 7 a preliminary survey for testing operativity and efficiency of gpr technology ... of the permittivity assumed for the medium. in the case of ice, the assumed value is equal to 4, in accordance with previous studies (e. g. daniels, 2004) the equipment used, mod. zond 12e radsys, consists of an acquisition and digitizing unit, compact and transportable by the operator, together with a netbook for recording and displaying data. the unit is connected to an antenna with a frequency suitable to the prospecting targets (depth and resolution), whereas low frequencies mean greater depth investigation and less resolution, and vice versa. therefore in this survey, considering the expected thickness of the ice mass, a low frequency antenna (150-75-38 mhz, set to 150 mhz) not coupled with the ground, was used. the gpr scans were positioned using reference points from which distances and elevations were measured with a nikon, model forestry pro 2 trigonometric diastimeter. 3. data acquisition the investigated area corresponds to the lower-middle glacier sector, down to the southern side of the terminal moraine (2696 m a.s.l.). all the height values in the scans below are relative to the snow conditions at the survey date; all the scans lengths are defined in a horizontal projection. three scans were performed with the aim to draw the geometry of the glacier bottom. the scans location is shown in fig. 3, on an aerial-photographic base. a longitudinal scanning (scanning l, fig. 4a) was performed in the north-south direction, parallel to the axis of the glacier. the starting point (to the north) was set at an altitude of 2670 m a.s.l., approximately corresponding with the contact between the moraine outcrop and the snow cover existing at the date of survey. the scanning passed through the lowest point, at an altitude of 2668 m a.s.l., and finally reached a length of 119 m, with the end point (to the south) at an altitude of 2700 m a.s.l. subsequently, a first transverse scan was performed (scanning t1, fig. 5a) with a west-east direction, intersecting the longitudinal scan near its starting point. the tranverse length was 152 m, with a starting point (to the west) at an altitude of 2705 m a.s.l. and an end point (to the east) at a height of 2676 m a.s.l. the lowest point corresponds to the intersection with the longitudinal scan l. the third scan (scanning t2, fig. 6a) intersects, with a west-east direction, the midpoint of the longitudinal scan and is 120 m long. the starting point (to the west) is located at an altitude of 2697 m a.s.l., the lowest point at 2669 m a.s.l. and the end point (to the east) at 2678 m a.s.l. in fig.7 the location of the scans is shown on a photographic base illustrating the snow conditions on july 11, slightly higher than those found on july 26, 2015. 4. results first step in data rendition was the examination of glacial and snow conditions as visible in site at the survey time, on 26 july 2015, then the gpr analysis was carried out with the aim of checking the presence and thickness of the following homogeneous units: 1. shallow firn; 2. debris cover blanket; 3. ice; 4. limestone bedrock. in the examination just basic processings were done, that is background removal run, appropriate signal gain and moveout correction, or rather parallax correction according to antenna size in order to get the right reading of deepness and achieve the correct reading of depth. under graphic rendering of soundings (radargrams) the elevation profiles of sections were drawn carefully getting a better view of glacier topography and a truly shape of the homogeneous units. finally, the altitude references (i.e. zero point of the radargram depth scale) were aligned to the lowest points of the bedrock surface in each profile, thus allowing a more convenient comparison between the different soundings. in the figures 4b, 5b and 6b coloured areas show the existence of a well-marked discontinuity, easily ascribable to the contact surface between the shallow firn layer and the underlying debris cover blanket. this interpretation is confirmed by the outcrop of such a contact surface on the initial section of profiles l and t1 (fig. 2, fig.3 the calderone glacier: aero-photographic image with contour levels and scan sections. 8 fig. 4b and 5b). all the radargrams show a well-defined discountinuity at the basis of the debris layer, confirming its scarce thickness as already pointed out to by fiucci et al. (1997) and de sisti et al. (1998). below this discontinuity, the lack of anomalies in the reflected signal allows to characterize the existence of a uniform mass, recognizable as ice. in the l scan radargram, the excellent signal quality allowed a reliable interpretation of the shape of the calderone glacier lower-middle part along the longitudinal axis of the glacial basin (fig.4b). the deepest discontinuity looks particularly clear; it is most likely ascribable to the contact between the glacier and the bedrock. a little beyond the point of 100 m the maximum depth is visible with regard to the firn surface at the moment of sounding, valuable about 32 m. as a result, the maximum ice thickness would amount to 26 m, bearing an overlying debris cover one meter thick and a 5 m thick firn blanket. the initial section (north) of the scan appears to be easily construable; the bedrock “rise” making up the basin threshold, and the above debris stockpile of the front moraine are well marked. in the final portion of t1 scan (fig. 5b) the contact between the glacier and the bedrock appears less clear, so that the direct contact between debris cover and limestone bedrock is possible, there locating the probable margin of ice mass at the glacier eastern side, just before the frontal moraine. similar reading uncertainty does exist in the neighborhood of point 100 m of scan t2 (fig. 6b), where presence of ice with a large amount of debris inside (rock glacier) is conceivable. anyway, t2 scan points out an unexpected thickness of ice at the western side of glacier basin, that as about 15 m in the first section (west) of the scan. ice shows fair thickness in the eastern side of the basin, too. fig. 4 georadar scan section l (a) and the same section with the units enhanced using different colours (b) . a b monaco a. & scozzafava m. 9 fig. 5 georadar scan section t1 (a) and the same section with the units enhanced using different colours (b). fig. 6georadar scan section t2 (a) and the same section with the units enhanced using different colours (b). fig.7 the georadar sections in a 3d view. a a b b a preliminary survey for testing operativity and efficiency of gpr technology ... 5. conclusions the execution of a preliminary survey on the calderone glacier, carried out with gpr technique and non surface-coupled antenna, has allowed to check the full practicality and efficiency of such a system, which permits to overcome inconveniences and limitations resulting from operating with surface-coupled antenna in case of strongly roughed surfaces. the quality of recorded signal has proved to be pretty good and satisfying, allowing an excellent depth of survey; the ice maximum thickness, as detected in the longitudinal scan, resulted equivalent to 26 meters, perfectly in agreement with previous studies, proving a significant and unexpected preservation of the icy mass in the last two decades. the scan processing has provided useful hints about the possible shape of the units that make up the glacier complex, with special regard to the front moraine morphology and the bedrock basal surface. furthermore, important information has been obtained concerning the unexpected thickness of sides of the glacier in the central area. positive results achieved with the carried out preliminary survey allow the planning of a more thorough and careful survey with the same technique and equipment, focused to get a detailed mapping of the glacier shape, that will be obtained by means of a regular grid of scans and based on a careful land survey. acknowledgements the authors wish to thank the meteorological association “aq caput frigoris”; special thanks are given to members thomas di fiore, alessandro ferrante, giampiero manzo, manuel montini, valerio sorani, francesco vaccaro for their technical and logistical support. thanks to mr. cristiano iurisci for the useful hints and a preliminary land survey of the site. references bogorodskiy v.v., bentley c.r., gudmandesn p.e. (1985) radio-glaciology. d. reidel publ. co., dordrecht, holland, pp. 254. de sisti g., marino a., pecci m. (1998)indagini georadar sul ghiacciaio del calderone del gran sasso d’italia: primi dati relativi alla ricostruzione dello spessore di ghiaccio residuo. gngts, atti del 17° convegno nazionale, pp. 6. daniels d.j. (2004) ground penetrating radar. the institution of engineering and technology, iet, pp. 725. fiucci a., gigante b., rossi c., smiraglia c., veggetti o. (1997) the calderone glacier (gran sasso d’italia). determination of ice thickness and bedrock morphology by means of radio-echo sounding. geografia fisica e dinamica quaternaria, 20, 305-308. funk m., bosch h., valla f. (1993) mesures del epaisseurs de glace par la methode radar au glacier de sarennes. societé hydrotecnique de france, section de glaciologie, reunion des 11 et 12 mars, grenoble, pp. 13. gellatly a.f., smiraglia c., grove j.m., latham r. (1994) recent variations of ghiacciaio del calderone, abruzzi, italy, journal of glaciology, 40, 136, 486-490. haeberly w., wachter h.p., schmid w., sidler c. (1983) erste erfahrungen mit dem us geological survey monoplus radioecholot im firn, eis und permafrost der svhweizer alpen, zeitschr. gletscherk. glazialgeol., 19, 61-72. marinelli o., ricci l (1916) alcune osservazioni sul ghiacciaio del gran sasso. riv. geogr. it, 23, 399-405. pecci m., smiraglia c., d’orefice m. (1997) il ghiacciaio del calderone. rivista aineva “neve e valanghe”, 32 (novembre 1997), pp. 57. smiraglia c, veggetti o. (1992) recenti osservazioni sul ghiacciaio del calderone (gran sasso d’italia -abruzzo). boll. soc. geogr. it. ser xi, 4, 269302. tonini d. (1961) il ghiacciaio del calderone del gran sasso d’italia. boll. com. glac. it., ser. 2, 10, 71135. 10 monaco a. & scozzafava m. ms. received: may 12, 2016 final text received: december 3, 2016 microsoft word 00_indice_lm01.doc available online http:/amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 26 (1), 2013, 77-94 glacier dynamics in san giacomo valley (central alps, sondrio, italy) tantardini davide1, riganti nausicaa1, taglieri pasquale1, de finis erika1, bini alfredo1 1 university of milan, department of earth sciences "a. desio", milano, italy corresponding author : davide tantardini <davide.tantardini@unimi.it> abstract: san giacomo valley is located in the central alps, and cross-cuts the alpine chain from n to s. geologically, it is dominated by the tambò and suretta alpine nappes, which influence the valley morphology: its southern part has regular slopes, whereas its northern part shows flat topographies correponding to the thrust surfaces of the tambò nappe. structural and geomorphological analysis highlighted the tectonic-structural origin of the valley. although the alpine valleys network changed during orogenesis, the morphology of san giacomo valley was only little modified at least since the miocene. the glacial erosion had negligible influence in shaping the valley forms. the large dimension of the glacial erosional morphologies in san giacomo valley can not be related with certainty to the last glaciation, but to glaciations in general, whereas small erosional morphologies and the depositional morphologies are most probably the result of the last glaciation. the observations carried out on glacial morphologies and the sedimentological study of tills indicate that san giacomo valley, at the last glacial maximum, was the accumulation zone of san giacomo glacier. from the trimline evidences, both the ice extension in the valley at the lgm and the longitudinal profile of the glacier were reconstructed. the valley at the glacial maximum hosted a single glacial tongue, with the exception of the truzzo-lendine glacier, which was suspended on the main glacier. the relationship between the san giacomo and the engadina-bregaglia glaciers is here also reconstructed. at the junction of the two glaciers, in chiavenna valley, the engadina-bregaglia glacier had higher elevation and larger mass than the san giacomo glacier. south of san giacomo valley, in chiavenna valley and in what is today upper lake of como, the san giacomo glacier was squeezed against the right valley slope, but then continued southward for some kilometers as a distinct glacier tongue. this inference is supported by the distribution of tills, which contain lithotypes sourced from the san giacomo valley. only during advanced stages of melting the san giacomo glacier tongue disappeared. the morphologies of the glacial melting phases were here used to reconstruct the evolution of the glacier tongues of the main and lateral glaciers, as well as to reconstruct their relationships. through the deglaciation, the accumulation zone gradually shrank and the ablation zone expanded, with contemporaneous upstream shifting. through the deglaciation, lateral glaciers parted from the major glacier and expanded, reaching their maximum extensions during the retreat of the main valley glacier. the recognizable retreat phases do not identify all the steps of glacial phases occurred, but only those whose sedimentological and morphological evidence has remained. the building of lateral moraines or the deposition of erratics occurred during minor glacial advances, which may have not had the same morphologic evidence throughout the valley. keywords: glacier dynamics; lgm; central alps; geomorphology; glacial reconstruction; glacial morphologies. 1. introduction in spite of some recent studies on the extent and timing of the last glaciation and deglaciation in the alpine region (e.g., kelly et al., 2004; ivy-ochs et al., 2006, 2008, 2009; reitner, 2007; starnberger et al., 2011; darnault et al., 2012), field-based knowledge about glacier dynamics in high valleys is still fragmentary. in the perspective of filling this lack of knowledge and providing a comprehensive field study, we focused on san giacomo valley, which is an isolated alpine valley wide enough (~200 km2) to be suitable for an accurate field survey. we mapped the valley landforms, and, in particular, the morphologic and sedimentological evidences connected to lgm glacier dynamics. we did not obtain dates for the events highlighted by morphologies and sediments, but we used their geometry and their position to obtain a relative sequence of events (identified by glacial advance phases during the general melting). in this way we could reconstruct san giacomo glacier dynamics in its final stages of melting. the data collected in san giacomo valley (de finis, 2012; riganti, 2012; taglieri, 2012; tantardini, 2012) include trimline elevations, position of significant erratics, mapping of the extension and geometry of moraines. a first interpretation of these field data has permitted to identify glacial retreat phases of the major glacier and of its tributary glaciers: these have been summarised in a map of the glacial retreat phases. on the basis of the identification and correlation of glacial phases, two paleogeographic maps of ice extent at different times are presented. 2. geographic and geologic overview val san giacomo (san giacomo valley is located in the central alps, and runs roughly n-s from passo dello spluga, to chiavenna. south of chiavenna, along the prosecution of san giacomo valley, lies piano di tantardini d. et al. 78 fig. 1 a) position of study area in the alps. b) geologic map of the examined region. a – thrust, b – certain fault, c – uncertain fault, d – certain tectonic line, e – uncertain tectonic line, 1 – quaternary deposits, 2 – paragneiss and mica schists, 3 – orthogneiss and mica schists, 4 – amphibolites, 5 – carbonatic metasedimentary cover, 6 – crystalline metasedimentary cover (mica schists, thin paragneiss, quartzites), 7 – orthogneiss, 8 – chiavenna ophiolites and rocks of oceanic domain, 9 – masino-bregaglia (bergell) intrusion (granites, granodiorites, diorites), 10 – truzzo intrusion (metagranites), 11 – bündnerschiefer, 12 – bündnerschiefer, schams nappe, 13 – bündnerschiefer, avers nappe. modified after the geologic and tectonic chart of switzerland 1:500 000. c) overall map of study area. toponyms here are the ones which the text refers to. fig. 2 schematic cross section of the southern san giacomo valley. the slope, constituted by the truzzo metagranite, presents a rounded morphology. glacier dynamics in san giacomo valley (central alps, sondrio, italy) 79 fig. 3 san giacomo valley seen from the southern slope of mt. cardine. it is possible to notice the change in morphology with respect to the southern portion of the valley. at altitudes between about 1800 and 2000 m the slope is much larger than in the valley bottom, and there are some large terraces on the thrust surface between suretta and tambò nappes (a – motta; b – andossi; c – pian dei cavalli). fig. 4 schematic cross sections of the pian dei cavalli area. 1: suretta-tambò nappes thrust; 2: inverse fault surface parallel to thrust surface. the cross sections shows how the topography is in many areas parallel or sub–parallel to the surfaces of inverse faults, representing, from a geomorphological point of view, structural sub-horizontal terraces and uplands. the difference between the upper valley slopes and the lower, more incised ones, is evident in section a). tantardini d. et al. 80 chiavenna, generally known as valchiavenna (chiavenna valley), which is wider than san giacomo valley. to the south, chiavenna valley forms a junction with valtellina and upper lake como. upstream, the valley is oriented east-west and is named val bregaglia (bregaglia valley) (fig. 1). chiavenna valley is located north of the insubric line (periadriatic lineament) which runs east-west along valtellina. in chiavenna valley, adula, tambò and suretta penninic nappes crop out, which consist of a crystalline pre-permian basement, lithologically composed of micaschists, paragneiss and metagranitoids. within the tambò nappe basement the truzzo metagranite is intruded. this is a late-variscan pluton, subsequently deformed by the alpine orogeny, which crops out in an east west belt and which transversely crosses san giacomo valley and continues in bregaglia valley. nappes are separated from permo-mesozoic metasedimentary covers, composed by metapelites and carbonates. in particular, within the metasedimentary cover of tambò nappe are spluga quartzites, which lie immediately beneath the other cited rocks and have been interpreted either as a part of the crystalline basement or as a metamorphosed permian riolitic sequence (sciesa, 1991). in san giacomo valley the nappes have a nearly tabular geometry and overlap each other in a regular way, with a general low dip towards east-northeast, whereas in southern chiavenna valley the same units are folded and tilted. 2.1. morphology of the valley the morphology of the southern part of san giacomo valley is closely connected to the presence of truzzo metagranite. the valley is narrow, with steep slopes, characterized by rounded outcrops (fig. 2) because of the curve fractures present in the metagranite (cloos, 1925; migòn, 2006). the morphology dramatically changes northwards (fig. 3): the valley becomes larger in the higher slopes, where there are also large flat surfaces (such as andossi and pian dei cavalli), whilst it remains narrow and more incised in the lower slopes (fig. 4, fig. 5). on some of these surfaces (andossi, pian dei cavalli, motta) the metasedimentary carbonatic covers crop out (fig. 5), so these surfaces correspond to the thrust surface of suretta nappe on tambò nappe. the other surfaces also correspond to structural surfaces parallel to the thrust surface. san giacomo valley itself, starting from the end of cardinello valley, is a structural valley formed along a strike-slip fault. san giacomo valley, as demonstrated by studies on perialpine sediments and on the structural evolution of the central alps (bernoulli et al., 1993; bersezio et al., 1993; brugel et al., 2000; carrapa & di giulio, 2001; gelati et al., 1991; giger & hurford, 1989; hansmann, 1996; kuhlemann, 2007; kuhlemann & kempf, 2002; sciunnach et al., 2004; schlunegger et al., 1998; schmid et al., 1996; spiegel et al., 2001), already existed during the miocene and, probably, it had gained the present morphology already in the upper miocene and during the messinian salinity crisis, as it is a tributary valley of lake como valley which deepened during the messinian, like most southalpine valleys (biella et al., 2001; bini, 1994; bini et al., 1978; brambilla & lualdi 1986; cita et al., 1990; cita & corselli, 1990; cita & corselli 1993; corselli et al., 1985; felber et al., 1991; felber et al., 1994; felber & bini, 1997; finchk, 1978; finchk et al.,1984; lualdi, 1981; quattrone et al., 1990; rizzini & dondi, 1978; rutishauer, 1986). therefore, glacial erosion is not the only cause of the morphology of san giacomo valley: weathering, denudation, slope dynamics and fluvial erosion have had greater importance in its formation. given that both glacial geometry and dynamics are influenced by land topography, it is useful to briefly describe the valley. loga valley, which can be considered as the upper part of san giacomo valley, is directed w-e and is wide, with a gently dipping valley bottom smoothly connected to the area of lake montespluga, which is one of the flat structural surfaces existing at the contact between suretta and tambò nappes. the flat area extends southwards in continuity with andossi area. a ne-sw fault, corresponding to the cardinello valley, causes the deviation of the valley axis and its fast deepening; the difference in height between lake montespluga and the valley bottom north of isola is about 600 m. the area of isola becomes a large, elongated depression surrounded by high and steep-sloped reliefs. from here up to piano di chiavenna the valley is perfectly straight. the flat, structural area of montespluga andossi continues southwards forming the terraces of motta, although separated from these terraces by scalcoggia valley, and, towards sw on the other side of the valley, fig. 5 panoramic view of pian dei cavalli. the photo is taken from the northern area of pian dei cavalli towards south. mount tignoso (in the center) is constituted by the rocks of suretta nappe, whereas pian dei cavalli is constituted by the carbonatic rocks of the tambò nappe cover. the thrust surface passes a few meters above the pian dei cavalli topography, hidden by the large rock glacier at the toe of mount tignoso. to the west the thrust folds upwards and crops out in the saddle between mount tignoso and the large carbonatic cuesta, the surface of which is practically coincident with the thrust surface. despite the distortion provoked by the panoramic view and the presence of till, it is evident that pian dei cavalli topography is parallel to the suretta-tambò thrust surface: to the east, the plain topography of pian dei cavalli is almost horizontal, while to the west it curves upwards as the thrust surface does on the carbonatic cuesta. glacier dynamics in san giacomo valley (central alps, sondrio, italy) 81 forms piano dei cavalli. some deeply incised lateral valleys connect to san giacomo valley bottom: febbraro valley, avero valley and drogo valley. these are structural valleys due to faults or to lateral contact with the intrusive body of truzzo metagranite. other valleys remain suspended on san giacomo valley, completely as sancia valley, or partially as rabbiosa and groppera valleys. these valleys end in more or less extended flat areas lying on structural surfaces which are at the contact between tambò and suretta nappes (groppera valley) or surfaces parallel to this (sancia, rabbiosa valley). at the junction with chiavenna valley, san giacomo valley deviates towards se following the edge of the truzzo metagranite intrusion. at this diversion, on the right slope of the valley, a nw-se ridge departs from mount mater and obstructs the right part of the valley. this ridge comes down from colones (1700 m a.s.l.) to pratomorello (1100 m altitude.s.l.), on a distance of 2,5 km, with a low gradient in the upper slope and then with a much more pronounced gradient near the valley bottom. 3. glacial morphology during the pleistocene, in the last 2,6 millions years, the upper lombardy plain and the terminal parts of alpine valleys were interested at least by thirteen glaciations (bini, 1996; bini, 1997)1. as the term “glaciation” is ambiguous, the definition of glaciation adopted here follows bini (1997): “the term “glaciation” is applied here to a specific glacial advance and recession, the deposits of which are separable from those of other glaciations by evidence of extensive recession and downwasting of glaciers, or by evidence of warm climate as interpreted from pollen diagrams or weathering profiles. the terms “warm” and “cold” are used here in a very general sense to indicate broad differences in the climate of intervals separating glaciations (richmond, 1986)”. the identification and the concept itself of a glaciation is therefore related to the observation of sediments and it follows that the number of glaciations can vary from an area to another, from mountain to upper plain, from the north slope of a ridge to the south slope, etc. as a consequence, even if in the prealpine morenic amphitheatres thirteen glaciations were recognized, it is possible that in the mountains, as in san giacomo valley, the situation was different. richmond & fullerton (1986), in fact, recognize various glaciations dated with chronometric methods during lower pleistocene and limited to mountainous areas (alaska, sierra nevada, wyoming, cascade mountains). if in north america there were glaciations in a period of time previously considered to be lacking great glaciations, such a situation is likely to have recurred in the alps too2, even if the absence of sedimentary evidence only permits to formulate hypothesis. so, in san giacomo valley it is reasonable to suppose that glaciations were more than thirteen (bini & pellegrini, 1998). in the internal alpine valleys, as in san giacomo valley, it is not possible to recognize the various glaciations, because the denudation and the erosion on slopes are very intense and so, apart from rare cases, older deposits were not preserved. only four outcrops of older-than-lgm glacial deposits are known in the whole valtellina (bini et al., in press; montrasio et al., 2012), whereas in san giacomo valley pre-lgm glacial deposits are absent. it is thus possible to recognize the sediments related only to the last glacial expansion (cantù glaciation, corresponding to the lgm) (bini, 1996; bini, 1997), well distinguishable thanks to the thin surface weathering horizon, less than one meter thick. moreover, in this region, all the glaciations had more or less the same extent and therefore their trimline must be comprised in a few tens of meters of altitude (ballantyne, 1997; benn & evans, 1998; bini, 1996; bini et al., 2009; kelly et al., 2004). 3.1. erosional morphologies all morphologies caused by glacial erosion are often ascribed to the last glaciation, for example some valley entrenchments of some hundreds of meters (perello et al., 2011). as the recognized glaciations related to adda glacier are thirteen, and there are no reasons to suppose that the last glaciation had a more important erosional behaviour than the former ones (the glaciers had a similar mass in all the glaciations; see references above), it is necessary to think that the currently observable morphologies result from the sum of the effects of all glaciations: in fact, if all the glaciations eroded a thickness similar to the one attributed to the last glaciation, the total thickness of eroded material would be enormous, and equal to thousands or even tens of thousands of meters in a portion of alpine chain which is about 2500 3000 m high. the development of san giacomo valley in its present-day morphology precedes all glaciations, as documented by studies on perialpine sediments and by the structural evolution of the central alps (see references above). the valley shows little evidence of large glacial erosional morphologies which, as a consequence, are unlikely to be related exclusively to the lgm, but to glaciations in general. on the contrary, morphologies with smaller dimensions can be ascribed to the last glaciation (bini et al., 2009), because it can be assumed that during interglacials weathering cancelled older morphologies. we observed glacial striae and ice-scoured rocks that act as ice flow indicators. obviously, glacial striae indicate flow directions coincident with valley directions; in some cases, however, due to a more flat topography, striae allow to determine the presence and the flow of the local glacier or of the valley glacier, like at alpe zocana, in the eastern part of pian dei cavalli, where glacial striae show an ice flow with an azimut of 175° (riganti, 2012), not compatible with the directions of flow of all the local glaciers that could have occupied the area, but only with san giacomo glacier.                                                              1 at present day, the “classic model” introduced by penk e bruckner (1909) based on four glaciations is no more valid (bowen, 1978; šibrava et al., 1986; bini, 1997): the objective data of the previously published works remain valid, but the interpretations do not. 2 in lombardy context a great glaciation is a glaciation, whose evidence is based on sediments, during which glaciers reach the upper plain.  tantardini d. et al. 82 fig. 6 gentle till at andossi. the photo is taken from the northeastern tip of andossi, towards sw. west of andossi, on the right side of the photo, there is cardinello valley; east of andossi there is scalcoggia valley. the junction between the two valleys is the isola depression, sw of andossi (center of the photo). during the lgm and the first stages of melting san giacomo glacier flowed over this area toward ssw. by phase san giacomo 65, the glacier became too thin to flow over andossi. so, an area of dead ice formed: the gentle till with scattered erratics was deposed at its complete melting. during advanced stages of melting the glaciers did not reach andossi, which was free from ice: and two glacial tongues flowed separately in cardinello valley (towards sw) and in scalcoggia valley (towards ssw). fig. 7 drumlin at andossi. the photo is taken from s towards n. the drumlin testifies an ice flow directed from nne to ssw. the drumlin (250 m long, 20 m large, up to 7 m high) is covered by thin glacial deposits (ablation till). in this flat topography area of andossi there are also some fluted moraines, oriented in the same direction. glacier dynamics in san giacomo valley (central alps, sondrio, italy) 83 3.2. depositional morphologies even if widespread, glacial deposits in san giacomo valley are thin (usually a few meters thick), except for some particular areas like in starleggia-sancia valleys between 1750 1800 m of altitude or on the eastern slope of mount mater. most deposits and the associated morphologies are related to the retreat phases of glaciers. with respect to evidences for the maximum expansion of san giacomo glacier, there are lateral moraines only in the southern part of the valley in drogo valley (two short moraines). in the rest of the valley, moraines are absent, and only subglacial morphologies like cover moraines and till plains (at andossi, pian dei cavalli, motta) (fig. 6), subglacial hills (at andossi, pian dei cavalli, loga valley, lendine valley), and drumlins (at andossi and lendine valley) (fig. 7) were observed. part of these morphologies (the ones located in andossi, lendine valley) could be linked to retreat phases of the glacier. lateral morphologies related to ice flow are absent even in areas with a flat topography favourable to the conservation of glacial morphologies, like at piano dei cavalli, where only scattered, thin till covers (mainly less than a meter thick) and boulders crop out. this implies that san giacomo glacier was not covered by debris. this fact, along with the position of the valley in the alps and its configuration, suggests that san giacomo glacier was in the accumulation zone and not in ablation zone almost as far as drogo valley. morphologies related to retreat phases of san giacomo glacier are more widespread: lateral moraines where the topography allows for their preservation (montespluga, andossi, motta, mount mater), erratics and hummocky moraines (drogo, starleggia, sancia and truzzo valleys, lake montespluga). minor glaciers, merging with the san giacomo glacier, could advance downstream only when the main glacier was retreating and was no longer blocking their flow. in lateral valleys (scisarolo valley, do valley, starleggia-sancia valleys, suretta valley, lake emet valley, angeloga valley) we observed many moraines deposited during these phases which, in some cases, reached low elevations. fig. 8 extension of glaciated area in san giacomo valley at the lgm. 1 – glaciated area; 2 – upper border of the glaciated area (trimline). the reconstruction was based upon trimline data (table 1) and assumed an analogy in behaviour with present glaciers. fig. 9 topographic profile of san giacomo valley and reconstructed surface of san giacomo ice mass (altitudes of the trimline). tantardini d. et al. 84 4. trimline and glaciers geometry during the maximum expansion in literature we can find various methods to identify the trimline. some authors (for example: florineth & schlüchter, 1998; kelly et al., 2004) set the trimline at the upper limit of erosional morphologies on bedrock. other authors (for example ballantyne et al., 1998) indicated that the trimline coincides with the upper limit of removal of weathered bedrock or debris by glaciers. to identify the trimline, kelly et al. (2004) used till and erratics (whereas van der beek & bourbon (2008) relied on drumlin and lateral moraines. the trimline also coincides with the line which separates bedrock deeply eroded by the glacier from not eroded bedrock and therefore deeply weathered by frost and by chemical and biological weathering (ballantyne et al., 1998; ballantyne et al., 2008). at the trimline a convex or concave slope rupture can often be observed, depending on bedrock geomechanical properties (florineth & schluchter, 1998). in this study we did not privilege a particular criterion, but we tried to identify the approximated or real trimline in all feasible ways. table 1 reports the data relative to the trimline found in san giacomo valley. all the trimline evidences can be related to the lgm: those in till thanks to the characteristics of their weathering profile (the most common soils in san giacomo valley are leptisols and thin cambisols with munsell soil color chart hue 10yr (comolli et al., 2011), and those identified thanks to erosional morphologies because the trimline evidences based on morphologies of bigger dimensions have the same altitudes as in previous glaciations (whereas smaller dimension morphologies previous to the lgm have been erased and, thus, the observable morphologies are related to the lgm). from these field data, a map of the maximum expansion of glaciers in san giacomo valley was drawn (fig. 8). the whole valley was occupied by ice and only the highest peaks and ridges were ice-free. only in the final southern part of the valley, we could find wide icefree slope areas, and in this sector the ablation zone of san giacomo glacier likely began, the evidence being the presence of lateral moraines. the major glacier trimline altitudes (tab. 1) projected onto the valley axis allow us to obtain a surface profile of san giacomo glacier (fig. 9) which is not the real glacier surface, but a reconstruction of the locus along the glacier’s axis with altitudes which equal the altitude of trimline. between the northern and the southern evidences of the trimline, san giacomo glacier decreased in altitudes of about 272 m along a distance of ca. 18 km, with an average slope of 0,9°. the glacier thickness between the valley bottom and the trimline, by assuming an adequate thickness (20-30 meters maximum) for the sediments in the valley bottom, was 450 m at lake montespluga (tl010), 600 m at mount cardinello (tl001), 1100 m at lake isola, 1150 m at campodolcino, 1230 m at cimaganda (tl002) and 1550 m at san giacomo filippo (tl007). the ice mass thickness, therefore, increased downstream. between lake montespluga and lake isola, along a distance of 2,8 km, ice thickness increased from 450 m tab. 1 trimline data identified in san giacomo valley. the asterisk after the identification code indicates a datum not related to the major glacier but related to one of minor glaciers. glacier dynamics in san giacomo valley (central alps, sondrio, italy) 85 to 1100 m because of a morphologic step along the valley bottom, whereas south of lake isola the increase in thickness was more gradual. san giacomo glacier, belonging to the adda and po hydrographic basins, came into contact at various points with glaciers in adjacent valleys belonging to rhine hydrographic basin, like at passo dello spluga, in suretta valley, in lake emet valley, in angeloga valley and in febbraro valley. from the point of view of ice volume, the most important lateral glacier was truzzo glacier which, during the maximum expansion, joined lendine glacier. during its maximum expansion the whole truzzo valley acted as the accumulation zone of truzzo glacier. in the southern part of truzzo basin the trimline was at 2310 m a.s.l. (tl008), whereas, on the other side of the same crest (fig. 10) san giacomo glacier had a trimline at 2153 m a.s.l. (tl002). as a consequence, because of the morphologic step (fig. 11), the truzzo glacier had to form an ice fall to join san giacomo glacier which was filling drogo valley. all the other glaciers are located in northern areas, within the accumulation zone which they are part of and, therefore, they are in direct continuity with san giacomo glacier. the areas not surmounted by glaciers were the watershed crests. mount cardine crest and, in the middle of the valley, pizzo truzzo and calcagnolo crests were also free from ice. furthermore, there were a series of little isolated nunataks (fig. 8). 5. relationships between san giacomo glacier and engadina-bregaglia glacier san giacomo and engadina-bregaglia glaciers joined in the area of chiavenna, and formed a single glacier which flowed southwards until it joined valtellina (adda) glacier. according to florineth (1998) and bini et al. (2009) the engadina-bregaglia glacier formed a glacial dome, located in the area of st. moritz, which reached ca. 3000 m of elevation, with thicknesses of about 1200 m. from this dome towards bregaglia valley, the glacier lowered in altitude down to 2250 m at the trimline located at villa di chiavenna (6 km east of chiavenna) (stevenazzi, 2010). at the morphologic step of maloja pass the glacier formed a ca. 200-m-high ice fall. the glacier slope west of maloja pass is lower than east of the pass (florineth, 1998; stevenazzi, 2010), and is approximately 0,7°. at present there is no evidence of the engadina fig. 10 position of san giacomo glacier (tl002, table 1) and truzzo glacier (tl008, table 1), and trimlines on the ridge between pizzo truzzo and pizzo camosciè. truzzo glacier is kept suspended over the major glacier by the morphologic step in the truzzo granitic intrusion (fig. 1). the dam area, where the suspended valley ends, suggests the presence of seracs (and of the consequent increase in ice flow velocity) because of the strong scouring of the bedrock and because of the presence (the only case in the valley) of glacial striae. legend: 1) significant erratic; 2) scattered erratics; 3) glacial exaration striae; 4) moraine crest; 5) trimline; 6) ice scoured rock; 7) reconstructed limit of glaciated area. tantardini d. et al. 86 bregaglia glacier trimline on the slope north of chiavenna or on the south-east one, while in the southern part of san giacomo glacier, a little upstream of the contact with engadina-bregaglia glacier, the glacier trimline is observed at 2058 m (tl007) and 2080 m (tl015) of altitude. because of this, the relationships between the two glaciers can only be hypothesized: by prolonging downstream the trimline of the two glaciers and assuming a constant gradient that is equal to the one in upstream areas, it is possible to calculate the expected altitude above chiavenna. this altitude is 2020 m for san giacomo glacier and 2170 m for engadinabregaglia glacier; the engadina-bregaglia glacier surface would have been about 150 m higher than san giacomo glacier surface (fig. 12). at the identified trimlines, engadina-bregaglia glacier had a volume that was about one fourth bigger than that of san giacomo glacier. south of chiavenna the widening of the valley with respect to northern areas must have caused a lowering in the altitude of the glacier’s surface. san giacomo glacier was therefore smaller than engadina-bregaglia and flowed into chiavenna valley with a minor thickness and a lower volume. nevertheless, even if the san giacomo was squeezed and stretched by the major glacier along the western slope of chiavenna valley, it was not completely blocked inside its valley, but it flowed together with engadina-bregaglia glacier at least for a certain distance. in fact, at mount berlinghera (fig. 13), located between the southern chiavenna valley and the northern end of lake como, approximately 13 km south of chiavenna, maggi (1992) found evidence of the presence of san giacomo glacier. the lithologic analysis of clasts in tills and erratics allowed recognition of two areas of distribution of clasts lithologies (maggi, 1992): from the lgm trimline (1685 m above sea level) down to about 800 m of altitude the marker lithotypes are truzzo metagranite (from san giacomo valley and/or bregaglia valley) and spluga quartzites (exclusively from san giacomo valley); between 800 and 700 m of altitude spluga quartzites are less common than truzzo metagranite, hence sediment coming from san giacomo valley diminishes while the material coming from bregaglia valley increases. masino valley granodiorite, from valtellina, has been found only 8 km downstream of mount berlinghera, in the area of sasso pelo, at 431 m of altitude as an erratic, and in tills below 400 m a.s.l.. so, during lgm, san giacomo glacier, in spite of the presence of the se crest of mount mater (colones) which hindered its flow, was a distinct glacial body flowing to the northern tip of lake como. the sharp cessation in the supply of spluga quartzites sediment implies a change in glacier dynamics. apparently, during melting, san giacomo glacier (which had a smaller accumulation zone than engadina-bregaglia: this latter is 2,5 times greater than san giacomo valley, considering bregaglia and engadine valley til st. moritz; florineth, 1998; bini et al., 2009), progressively decreased its mass with respect to the engadina-bregaglia glacier, until it disappeared as a distinct glacier just south of chiavenna, with consequent dispersal of spluga quartzites in a greater glacial mass and their mixing within the other transported sediments. 6. geometry of glaciers during retreat the reconstruction of glaciers retreat phases was based on the position and the morphology of moraines fig. 11 drogo valley seen from east (daloo) towards west. on the left slope of the valley there is a morphologic step at the junction with truzzo valley. at the lgm, truzzo glacier flowed from its valley over this step towards san giacomo glacier which filled drogo valley. san giacomo glacier trimline was, in this area, ca. 250 m lower than the truzzo glacier trimline (fig. 10), so the latter glacier formed an ice fall over the morphologic step. glacier dynamics in san giacomo valley (central alps, sondrio, italy) 87 and on the position of significant erratics, that is the erratics which remained in their original depositional position at glacier margin, by accounting for the geometry of the glacier and the present-day behaviour of major glaciers (ballantyne et al., 1998; ballantyne et al., 2008; bini et al., 2009; kelly et al., 2004; florineth & schlüchter, 1998). during the maximum glacial expansion, lateral glacial tongues could have been blocked within their own valleys by the mass of the major glacier tongue (bini, 1999), as it can be observed even in present-day glaciers. this is the case of san giacomo valley. during melting, the glaciers’ mass balance was negative, but while the major glacier lost volume and moved upstream retreating from lateral valleys, the lateral glaciers advanced because they were not anymore blocked by the major glacier, which acted as a dam (bini, 1999). the smaller glaciers could therefore deposit moraines and erratics on slopes in areas previously occupied by the major glacier and at lower altitudes than its lateral moraines. even in this case there are several examples of this dynamics in present glaciers. the advance of lateral glaciers into the major valley is temporary and of short duration: then, they retreat (bini, 1999). in san giacomo valley, by considering the valley topography, moraines are not so common, and, when present, they are not very long and are not distributed in an homogeneous way, but they are concentrated in areas or slope zones. so the retreat phases can be reconstructed and correlatable only in limited areas, whereas among different areas they are correlatable in a more difficult way (groups of standalone glacial phases come out). each phase was identified with an alphanumeric identification number starting from the most recent evidence (fig. 14). 6.1. san giacomo glacier as the major glacier retreated, the accumulation zone of the glacier moved northwards, and the glacier began to feel more and more the effect of the topography of the valley and of the slopes; minor glaciers in lateral valleys began to move downstream towards san giacomo valley valley bottom. at colones, where the southeastern ridge of mount mater is extended transversely to the ice flow, during the maximum expansion the glacier was thick enough to overstep the crest and flow southwards (there are about 330 m of difference in height between the trimline and the crest). as the glacier was losing thickness during the retreat, the presence of the crest confined more and more the glacier flow until phase colones 31 (see fig. 14) when the ice mass was blocked by the crest, and was forced fig. 12 a) schematic reconstruction of the relationship between lgm san giacomo and engadina-bregaglia glaciers. san giacomo glacier was, at trimline, about 160 m lower than engadina–bregaglia glacier, and forced on the right slope of chiavenna valley, while the majority of the available volume was occupied by engadina-bregaglia’s glacial mass. the medial moraine was drawn on the basis of the behaviour of present glaciers (modified after taglieri, 2012). b) map of the area crossed by section a) (dashed line). fig. 13 position of the area described in maggi (1992): the area is situated at the confluence between chiavenna (coming from north) and valtellina (from east) valleys, on a slope placed in front of the adda glacier tongue which came from valtellina and in a lateral position in respect to engadina-bregaglia glacier. the tills that can be found in this area allow reconstructing the dynamics between the two valley glaciers. distribution areas of marker lithologies: 1) truzzo metagranite and spluga quartzite; 2) only truzzo metagranite; 3) erratic boulder contituted by masino–bregaglia intrusive rocks; 4) maximum extent reached by ice in the last glaciation (modified after maggi, 1992). tantardini d. et al. 88 fig. 14 map of glacial phases that were reconstructed in san giacomo valley. the numbering identifies the phase of the glacier, with smaller numbers for more recent phases and greater numbers for older phases. a different way of numbering (greater numbers toward greater altitudes) was used for the phases in glacial series daloo, olmo and colones, because of the impossibility to correlate them with glacial phases more to the north. glacier dynamics in san giacomo valley (central alps, sondrio, italy) 89 to deviate its flow towards ese. this configuration remained until phase colones 7; in the following phases the glacier, thanks to different slope topography, flowed towards se. on the opposite slope of the valley, at 1350 m of altitude (see fig. 14), we observed a moraine belonging to engadina-bregaglia glacier (phase daloo 10) (fig. 15), cut by two san giacomo moraines (daloo 8 and 9). this implies that, during retreat, engadina-bregaglia glacier partly entered into san giacomo valley in some glacial phases, partially blocking or deviating san giacomo glacier. while in the southern sector of san giacomo glacier these retreat phases were taking place, in the northern area ice thickness was still almost at its maximum: a loss in thickness of hundreds of meters in the southern sector corresponded to a loss of few tens of meters, maybe even few meters in the northern zone (bini a., 1996). san giacomo glacier retreat implied a loss of ice volume that resulted in a rapid abandonment of flat topography areas, as that of pian dei cavalli, accompanied by a similarly sudden advance of lateral glaciers. in phase san giacomo 68 pian dei cavalli was already free from ice and the major glacier reached 2150 m a.s.l., which was about 150 m below trimline. by phase san giacomo 65, san giacomo glacier formed a narrow tongue in febbraro valley that reached the scarp which separated the lower from the upper valley. north of febbraro valley and motta, on the opposite slope of the valley, the glacier was still in contact with lateral glaciers, while in the andossi area during this phase (phase san giacomo 65) a particular evolution begins, testified by the great quantity of scattered erratics in this area (fig. 2). at andossi, while melting continues, the ice became too thin to allow flow of the glacier which, over this area, was blocked and became dead ice; at the same time in the two valleys contiguous to andossi, scalcoggia valley in the west and cardinello valley in the east, the ice was thick enough to allow flow. the position of andossi, and the setting of the dead ice area, progressively divided the san giacomo glacier tongue. as melting proceeded, san giacomo glacier passed from a single and very wide tongue that flowed almost from north to south covering all the andossi area, to a smaller tongue forced to flow into cardinello valley, where it joined ferrè glacier, and into scalcoggia valley where it fig. 15 panoramic view of the area of daloo. the photo is taken from nne towards ssw. san giacomo glacier flowed into chiavenna valley (top center of the photo) from n (bottom-right corner of the photo), while engadina-bregaglia glacier came from e (left side of the photo). a – san giacomo glacier moraine (phase daloo 8). b – san giacomo glacier moraine (phase daloo 9), lying from n toward s. c – moraine deposited by the engadina–bregaglia glacier (phase daloo 10), oriented from e to w, highlighted by some little till hills near the lake and by the presence of erratics along its crest. it is evident the perpendicularity between moraine b and moraine c (deposited by glaciers flowing in different valleys) and the erosion of the western tip of the engadina-bregaglia moraine carried out by the phase daloo 9 moraine. tantardini d. et al. 90 joined spadolazzo and emet glaciers coming from ne (fig. 16). as the retreat proceeded, the glacier decreased in thickness and occupied only the bottom of san giacomo and cardinello valleys, leaving andossi progressively devoid of dead ice. at phase san giacomo 34, andossi was completely free from active ice and the glacier reached isola due to the flow of ferré glacier, which, in this phase reached almost all the way down to the valley bottom. from phase san giacomo 33 the glacier had completely retreated from cardinello valley and was progressively retreating into loga valley. 6.2. lateral glaciers the most important lateral glacier is for certain truzzo glacier which, during the maximum expansion, was united to lendine glacier. the drogo valley morphology caused a rapid loss of mass of the two glaciers and separation from san giacomo glacier when this reached ca. 1050 m above sea level and had a thickness of more than 400 m (phase olmo 4, corresponding in the north with a san giacomo phase comprised between 60 and 57), still blocked southward from the se crest of mount mater. lendine glacier retreated upwards in lendine valley leaving behind dead ice, while truzzo glacier, occupying only truzzo valley, was hanging above the scarp below the dam (see fig. 10). angeloga glacier divided from san giacomo glacier during phase san giacomo 49 or 50, when san giacomo was approximately at 1500 m of altitude in rabbiosa valley and had a thickness exceeding 500 m. the topography of nw slope of pizzo stella, which contained angeloga glacier, is such that the glacier during retreat divided into a series of separated minor glaciers. quadro and starleggia glaciers descended starleggia valley with a low gradient until the sharp morphologic step that overlooks san giacomo valley, where these glaciers probably formed an ice fall towards san giacomo glacier. it is not possible to infer in which phase the separation occurred, probably between san giacomo 53 and 44 when san giacomo glacier was over 500 m thick. as sancia and starleggia valleys have a relatively flat valley bottom, quadro and starleggia glaciers deposited a series of moraines (41 moraines, from 1750 m a.s.l. to 2600 m a.s.l.), even very long ones (in phases quadro 3, quadro 5, quardo 12, quadro 13, quadro 14, quadro 17), which recorded the retreat phases with a good detail (fig. 17). all the other lateral glaciers occupy more sloping valleys and with the retreat of san giacomo glacier they advance towards the major valley bottom; the altitudes reached depend on the dimensions of the accumulation zone. among these, the major are emet, fortezza, ferré and vamlera glaciers 7. conclusions structural and geomorphological analysis of san giacomo valley (de finis, 2012; riganti, 2012; taglieri, 2012; tantardini, 2012) revealed that valleys in the alps had a tectonic-structural origin, that is they formed during and because of tectonic movements. moreover, the valley network had continuosly changed during the orogenesis, but the valleys already existed (brugel et al., 2000; spiegel et al., 2001). san giacomo valley has fig. 16 extension of glaciated area in san giacomo valley during one of the last phases of the deglaciation. 1 – glacier; 2 – external border of the glaciers; 3 – dead ice; 4 – subglacial lake; 5 – subglacial and subaereous streams. the reconstruction is based on hypothetic correlations between the various glacial phases identified (fig. 14), assuming as contemporaneous the glacial phases: san giacomo 44, ferrè s 9, spadolazzo 6, emet 14, sterla 5, fortezza e 5, fortezza w 2, vamlera 6, latta 1, piani n 1, piani s 5, bianco 2, baldiscio 1, bardan 2, starleggia 5, quadro 11, groppera 2, peloso 1, angeloga a 1; angeloga b 6, angeloga c 6 angeloga d 2, truzzo 3, colla 3, crespallo 1. glacier dynamics in san giacomo valley (central alps, sondrio, italy) 91 been in its present-day position since the miocene (bernoulli et al., 1993; bersezio et al., 1993; carrapa & di giulio, 2001; gelati et al., 1991; giger & hurford, 1989; hansmann, 1996; kuhlemann, 2007; kuhlemann & kempf, 2002; sciunnach et al., 2004; schlunegger et al., 1998; schmid et al., 1996; spiegel et al., 2001) and its morphology has varied only very slightly since the messinian salinity crisis. in several alpine valleys, the erosive action of glaciers was minimal, and resulted from erosion and weathering occurred throughout all glaciations and not only throughout the last glacial maximum. the study of glacial evidences in san giacomo valley allowed us to reconstruct the extension of glaciers at the lgm and during various phases of the deglaciation with a fairly good geometric precision. several alpine valleys similar to san giacomo valley, which initiate from the watershed ridge and are relatively short, did not host glacier tongues in ablation (except, in some cases, in their terminal part), but only the accumulation zone of the glaciers. even if san giacomo valley has not a typical accumulation area morphology, it represented during the maximum expansion phase the zone of formation of ice. over a length of ca. 25 km, the san giacomo glacier ablation tongue occupied only the last 7 km of the valley. by contrast, during the deglaciation, the accumulation zone gradually shrank and moved upstream, while the ablation zone expanded. a similar evolution, but with inverse polarity, may have occurred during the glacial advance, although this remains speculative, giving that there is no evidence of this process. since the whole valley was the accumulation zone of ice, lateral valley glaciers during the maximum expansion were in direct continuity with the major glacier mass: there was no welding among the various glaciers, because actually they were the same glacier, the same glacial body. the only exception was truzzo-lendine glacier because it came from a lateral valley apart from san giacomo valley and, above all, because it joined san giacomo glacier already in its ablation zone. throughout the deglaciation, lateral valley glaciers parted from the major glacier and gained progressively more importance. most lateral glaciers reached their maximum extension at the complete retreat of the major glacier: in this moment lateral glaciers could flow downvalley a lot below trimline altitude. retreat phases recognizable in the valley and identified in the reconstructions identify only those glacial phases whose evidences remained. building of lateral moraines or abandonment of erratics in particular positions (hills, ridges…) occured only in minor glacial advance events, which may not have had the same morphologic evidence (the same intensity, appearance, size) in the whole valley. it follows that our correlations (fig. 14) are hypothetical, and based on present-day fig. 17 moraines of starleggia valley seen from the southern slope of the valley. the photo is taken from s towards n. sancia glacier flowed from sancia valley, at w (beyond the left side of the photo); starleggia glacier flowed from starleggia valley, at nw (left-top corner of the photo). in this area the two glaciers joined in an only glacial tongue which flowed eastward. the western, more recent moraines of starleggia-sancia glacier forms a semicircular morainic amphitheatre in the area where the two glaciers joined, which partially erodes the eastern, more ancient, e-w oriented moraines. tantardini d. et al. 92 glacier geometry models (as in bini et al., 2009). the absence of radiometric dating of moraines makes it impossible to establish assured correlations. acknowledgements the research was supported by the “comunità montana di valchiavenna” in the framework of the 20092011 agreement with the “stazione valchiavenna per lo studio dell’ambiente alpino” (responsible prof. t. apuani), branch of the department of earth sciences university of milan) at which go the thanks of the authors. special thanks go to prof. raffaella proserpio, prof. silvia frisia and prof. andrea borsato for their essential help with english. we also thank prof. paolo mozzi for the careful revision of the manuscript and for his helpful advice. references ballantyne c. k. (1997) periglacial trimlines in the scottish highlands. quaternary international, 3839, 119-136. ballantyne c. k., mccarroll d., nesje a., dahl s. o., stone j. o. (1998) the last ice sheet in northwest scotland: reconstructions and implications. quaternary science reviews, 17, 1149-1184. ballantyne c. k., stone j. o., mccarroll d. (2008) dimensions and chronology of the last ice sheet in western ireland. quaternary science reviews, 27, 185-200. benn d.i., evans d.j.a. (1998) glaciers and glaciation. edward arnold, london, uk, pp. 734. bernoulli d., giger m., muller d.w., ziegler u.r.f. (1993) sr-isotope stratigraphy of the gonfolite group (“south-alpine molasse”, northern italy) and radiometric constraints for its age of deposition. eclogae geologicae helvetiae, 86, 751-767. bersezio r., fornaciari m., gelati r., napolitano a., valdisturlo a. (1993) the significance of the upper cretaceous to miocene clastic wedge in the deformation history of the lombardian southern alps. géologie alpine, 69, 3-20. biella g., de franco r., caielli g., vignola p., lozej a., bini a., guglielmin m., carbonara s., terenzoni m. (2001) imaging the deposits that fill valtellina (nw italy) by seismic reflection investigation. 5th workshop alpine geological studies. geol. paläont. mitt. innsbruck, 25, 33-34. bini a. (1994) rapports entre la karstification periméditerranéenne et la crise de salinité du messinien: l’exemple du karst lombard. karstologia, 23, 3353. bini a. (1996) la massima estensione dei ghiacciai (meg) nel territorio compreso tra il lago di como, il lago maggiore e le rispettive zone di anfiteatro. bini a. (1997) problems and methodologies in the study of the quaternary deposits of the southern side of the alps. southern alps quaternary geology, igcp 378 meeting, lugano, ch, october 1995. geologia insubrica, 2(2), 11-20. bini a. (1999) dispense di geologia del quaternario. geologia del glaciale in montagna. aiqua. bini a., felber m., pomicino n., zuccoli l. (1997) stratigraphy, chronology and palaeogeography of quaternary deposits of the area between the ticino and olona rivers (italy-switzerland). southern alps quaternary geology, igcp 378 meeting, lugano, ch, october 1995. geologia insubrica, 2(2), 21-46. bini a., buoncristiani j.-f., couterrand s., ellwanger d., felber m., florineth d., graf h. r., keller o., kelly m., schlüchter c., schoeneich p. (2009) die schweiz während des letzteiszeitlichen maximums (lgm). bundesamt für landestopografie swisstopo. bini a., cita m.b. e gaetani m. (1978) southern alpine lakes: hypothesis of an erosional origin related to the messinian entrenchment. marine geology, 27, 271-288 bini a., giannini f., gotti d. (2012) evidenze glaciali precedenti lo lgm in val tartano e val d'arigna. in press. bini a., pellegrini a. (1998) geologia del quaternario. in bini a., pellegrini a. (eds): il carsismo del moncodeno (ricerche sugli aspetti del fenomeno carsico profondo nel gruppo delle grigne: vii il carsismo del moncodeno). geologia insubrica, 3(2), 37-56. bowen d. q. (1978) quaternary geology: a stratigraphic framework for multidisciplinary work. pergamon, pp. 221. brambilla g., lualdi a. (1986) il pliocene della provincia di bergamo (italia settentrionale). analisi faunistica ed inquadramento cronologico e paleomabientale. boll. soc. paleont. ital., 25(3), 237-266. brügel a., dunkl i., frisch w., kuhlemann j., balogh k. (2000) the record of the periadriatic volcanism in the eastern alpine molasse zone and its palaeogeographic implications. terra nova, 12, 42-47. carrapa b., di giulio a. (2001) the sedimentary record of the exhumation of a granitic intrusion into a collisional setting: the lower gonfolite group, southern alps, italy. sedimentary geology, 139, 217-228. cita m.b., bini a., corselli c. (1990) superfici di erosione messiniane: una ipotesi sull'origine dei laghi sud alpini. in: barbanti l., giussani g., de bernardi r. (eds): il lago maggiore dalla ricerca alla gestione. simp. 50° anniv. fondaz. ist. it. idrobiol., pallanza, 1988, 33-54. cita m.b., corselli c. (1990) messinian paleogeography and erosional surfaces in italy: an overview. palaeogeography, palaeoclimatology, palaeoecology, 77, 67-82. cita m.b., corselli c. (1993) messiniano: vent'anni dopo. mem. soc. geol. it., 49, 145-164. cloos h. (1925) einführung in die tektonische behandlung magmatischer erscheinungen (granittektonik), i. spezieller teil. das riesengebirge in schlesien. bau, bildung, und oberflachengestältung. borntraeger, berlin, pp. 194. corselli c., cremaschi m., violanti d. (1985) il canyon messiniano di malnate (varese): pedogenesi tardomiocenica ed ingressione marina pliocenica al margine meridionale delle alpi. riv. it. paleont. strat., 91(2), 259-286. comolli r., bernardelli e., ferrè c. (2011) pedologia: tipi di suolo e loro caratteristiche. in: aldighieri b., mazzoleni g. (eds.) (2011). la valchiavenna: un glacier dynamics in san giacomo valley (central alps, sondrio, italy) 93 bacino pilota per il controllo dell’ambiente alpino. quaderni di geodinamica alpina e quaternaria, i.d.p.a., c.n.r., milano. darnault r., rolland y., braucher r., bourlès d., revel m., sanchez g., bouissou s. (2012) timing of the last deglaciation revealed by receding glaciers at the alpine-scale: impact on mountain geomorphology. quaternary science reviews, 31, 127-142. de finis e. (2012) cartografia geomorfologica della val san giacomo (in preparation for printing). felber m., frei w., heitzmann p. (1991): seismic evidence of pre pliocene valley formation and filling in the region of novazzano (southern ticino, switzerland). eclogae geol. helv., 84(3), 753-761. felber m., bini a., heitzmann p., frei w. (1994) evidenze sismiche di valli sepolte nel mendrisiotto e nel piano di magadino (ticino, ch). proc. symp. "crop alpi centrali, sondrio 1993, in: quaderni di geodinamica alpina e quaternaria, 2, 103-133. felber m., bini a. (1997) seismic survey in alpine and prealpine valleys of ticino (switzerland): evidences of a late-tertiary fluvial origin. southern alps quaternary geology, igcp 378 meeting, lugano, ch, october 1995. geologia insubrica, 2(2): 46-47. finchk p.g. (1978) are southern alpine lakes former messinian canyons? geophysical evidence for pre-glacial erosion in the southern alpine lakes. marine geol., 27, 289-302. finckh p., kelts k., lambert a. (1984) seismic stratigraphy and bedrock forms in perialpine lakes. bull. geol. soc. am., 95, 1118-1128. florineth d. (1998) surface geometry of the last glacial maximum (lgm) in the southeastern swiss alps (graubünden) and its paleoclimatological significance. eiszeitalter und gegenwart, 48, 23-37. florineth d., schlüchter c. (1998) reconstructing last glacial maximum (lgm) ice surface geometry and flowlines in the central swiss alps. eclogae geologicae helvetiae, 91, 391-407. gelati r., napolitano a., valdisturlo a. (1991) results of studies on the meso-cenozoic succession in the monte olimpino 2 tunnel. the tectonosedimentary significance of the “gonfolite lombarda”. rivista italiana di paleontologia e stratigrafia, 97, 565-598. giger m., hurford a.j. (1989) tertiary intrusives of the central alps: their tertiary uplift, erosion, redeposition and burial in the south-alpine foreland. eclogae geologicae helvetiae, 82, 857-866. hambrey m.j. (1994) glacial environments. university college london press, london, 296 pp. hansmann w. (1996) age determination on the tertiary masino-bregaglia (bergell) intrusives (italy,switzerland): a review. schweizerische mineralogische und petrographische mitteilungen, 26(3), 421-451. ivy-ochs s., kerschner h., reuther a., maisch m., sailer r., schaefer j., kubik p.w., synal h.a., schlüchter c., (2006) the timing of glacier advances in the northern european alps based on surface exposure dating with cosmogenic 10be, 26al, 36cl, and 21ne (conference paper). special paper of the geological society of america, 415, 43-60. ivy-ochs s., kerschner h., reuther a., preusser f. heine k. maisch m., kubik p.w., schlüchter c. (2008) chronology of the last glacial cycle in the european alps. journal of quaternary science, 23, 559-573. ivy-ochs s., kerschner h., maisch m., christl m., kubik p.w., schlüchter c. (2009). latest pleistocene and holocene glacier variations in the european alps. quaternary science reviews, 28, 21372149. kelly m.a., buoncristiani j.f., schlüchter c. (2004). a reconstruction of the last glacial maximum (lgm) ice-surface geometry in the western swiss alps and contiguous alpine regions in italy and france. eclogae geologicae helvetiae, 97, 57-75. kuhlemann j. (2007) paleogeographic and paleotopographic evolution of the swiss and eastern alps since the oligocene. global and planetary change, 58, 224-236. kuhlemann j., kempf o. (2002) post-eocene evolution of the north alpine foreland basin and its response to alpine tectonics. sedimentary geology, 152, 45-78. lualdi a. (1981) il pliocene di clanezzo in vall'imagna (bergamo): indagine faunistica. atti ist. geol. univ. pavia, 29,120-127. maggi v. (1992) geologia del quaternario del monte berlinghera e del pizzo sasso canale (provincia di como). il quaternario, 5(2), 235-250. migòn p. (2006) granite landscapes of the world. oxford university press, pp. 384. montrasio a., berra f., cariboni m., ceriani m., deichmann n., ferliga c., gregnanin a.,guerra s., guglielmin m., jadoul f., longhin m., mair v., mazzoccola d., sciesa e., zappone a. (2012) note illustrative alla carta geologica d’italia alla scala 1: 50.000. foglio 024 bormio. penck a., brückner e. (1909) die alpen im eiszeitalter. dritter band. die eiszeiten in den sudalpen und im bereich der ostabdachung der alpen. tauchnitz, leipzig. perello p., gianotti f., monopoli b., carraro f., venturini g., fontan d., schiavo a., bonetto f. (2011) note illustrative della carta geologica d’italia alla scala 1:50.000. foglio 089 courmayeur. quattrone p., rogledi s., longoni r. (1990) gas fields in the tertiary sequences of the milano bergamo region. bull. ver schweiz. petroleum-geol. u. ing., 57, 53-64. richmond g.m. (1986) stratigraphy and chronology of glaciations in yellowstone national park. in: šibrava v., bowen d.q., richmond g.m. (eds.): quaternary glaciations in the northern hemisphere. report igcp n°24, quaternary science reviews, 5(1-4), 83-98. reitner, j.m. (2007) glacial dynamics at the beginning of termination i in the eastern alps and their stratigraphic implications. quaternary international, 164-165, 64-84. richmond g.m., fullerton d.s. (1986) summation of quaternary glaciations in the united states of america. in: šibrava v., bowen d.q., richmond g.m. (eds.): quaternary glaciations in the northern hemisphere. report igcp n°24, quaternary science reviews 5(1-4), 183-196. riganti n. (2012) studio della geologia del quaternario e della geomorfologia del versante destro della tantardini d. et al. 94 media val san giacomo, compresa tra il piano dei cavalli e l'alpe boggi, e ricostruzione delle fasi relative all’ultimo massimo glaciale. università degli studi di milano. unpublished graduation thesis. rizzini a., dondi l. (1978) erosional surface of messinian age in the subsurface of the lombardian plain (italy). marine geology, 27, 303 325. rutishauser v. (1986) das südtessin im neogen: zwischen schuttstrom und schelfmeer. eine fazies und ablagerungsraumanalyse. diss. eth zürich, pp. 151. sciesa e. (1991) geologia delle alpi centrali lungo la traversa colico-passo dello spluga (province di sondrio e como). il naturalista valtellinese. atti mus. civ. stor. nat. morbegno (2), 3-34. sciunnach d., tremolada f. (2004) the lombardian gonfolite group in central brianza (como and milano provinces, italy): calcareous nannofossil biostratigraphy and sedimentary record of neo-alpine tectonics. eclogae geologicae helvetiae, 97(1), 119-131. šibrava v., bowen d. q., richmond g. m. (1986) quaternary glaciations in the northern hemisphere. (report of the international geological correlation programme. project 24). quaternary science reviews, 5, pp. ix-511. schlunegger f., slingerland r., matter a. (1998) crustal thickening and crustal extension as controls on the evolution of the drainage network of the central swiss alps between 30 ma and the present: constraints from the stratigraphy of the north alpine foreland basin and the structural evolution of the alps. basin research, 10, 197-212. schmid s.m., pfiffner o.a., froitzheim n., schönborn g., kissling e. (1996) geophysical-geological transect and tectonic evolution of the swiss-italian alps. tectonics, 15(5), 1036-1064. spiegel c., kuhlemann j., dunkl i., frisch w. (2001) paleogeography and catchment evolution in a mobile orogenic belt: the central alps in oligomiocene times. tectonophysics, 341, 33-47. starnberger r. , rodnight h., spötl c. (2011) chronology of the last glacial maximum in the salzach palaeoglacier area (eastern alps). journal of quaternary science, 26, 502-510. stevenazzi s. (2010) dinamica di versante e ricostruzione del ghiacciaio durante l’ultimo massimo glaciale in val bregaglia, versante destro, comune di villa di chiavenna (so). unpublished graduation thesis. taglieri p. (2012) studio della geologia del quaternario e della geomorfologia del versante destro dell’alta val san giacomo, compresa tra la valle scisarolo e la val febbraro, e ricostruzione delle fasi relative all’ultimo massimo glaciale. università degli studi di milano. unpublished graduation thesis. tantardini d. (2012) studio della geologia del quaternario e della geomorfologia della sponda destra della bassa val san giacomo tra la valle di servizio e la valle del drogo, e ricostruzione delle fasi relative all’ultimo massimo glaciale. università degli studi di milano. unpublished graduation thesis. van der beek p., bourbon p. (2008) a quantification of the glacial imprint on relief development in the french western alps. geomorphology, 97 (1-2), 52-72. ms. received: november 16, 2012 final text received: may 10, 2013 available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 34 (1), 2021, 109-130 the quaternary paleontological research in the campagna romana (central italy) at the 19th-20th century transition: historical overview. marco romano 1, beniamino mecozzi 1, raffaele sardella 1 1 dipartimento di scienze della terra, sapienza, university of rome, rome, italy. corresponding author: beniamino mecozzi <beniamino.mecozzi@uniroma1.it> abstract: the rome basin, including the historical region of campagna romana, is considered as one of the most important sedimentary basin of peninsular italy for a paleontological viewpoint. a very high number of fossiliferous findings were collected from deposit which have a strong relationship with the evolution of the tiber river fluvio-deltaic evolution (the “paleo-tiber” system). this evolution is the result of complex geological processes including tectonic, volcanism and glacio-eustatic fluctuations. a myriad of fossils were recovered during the end of 1800 and the beginning of 1900, mainly thank to the intense urbanization which affected the city of rome. the majority of these historical fossil collection are today stored at “museo universitario di scienze della terra”, sapienza, university of rome (must), whereas sporadic specimens are kept in the scientific cabinets of several high school of the city or latium villages. several personalities of that time played a key role in the study of quaternary fossiliferous deposits describing stratigraphical succession and fossil remains. the knowledge of these researchers and their histories have a crucial importance to reconstruct the storytelling of the historical fossil collection and to get more information on fossiliferous deposit today destroyed by urbanization or buried below anthropogenic deposits. keywords: quaternary fauna, history of palaeontology, history of geology, giuseppe ponzi, alessandro portis. 1. introduction the city of rome is placed in the centre of the historical region of campagna romana (roman campaign). complex geological processes, occurred in particular during the middle pleistocene, are at the origin of the landscape where the “città eterna” (eternal city) was build (funicello et al., 2006; heiken et al., 2007). remains of large fossil bones from the roman area have been known since ancient times. however, due to the lack of knowledge in the field of zoology and comparative anatomy, in several cases the huge fossil bones served in the past centuries as basis for foraging the myths of giants, cyclops, leestrigons and lithophages, as in many other cultures around the world (mayor, 2000; avanzini & kustatscher, 2016; romano & avanzini, 2019). when correctly recognized as the remains of fossil elephants, in several cases the findings were linked to the only historical occasions in which these animals reached the italian peninsula, namely the elephants led by hannibal during the punic wars between rome and carthage (romano & palombo, 2017). even if such interpretations may seem childish and superficial, we have to consider that fossils in general were interpreted as freaks of nature well into the eighteenth century (rudwick, 1972; accordi, 1975, 1978, 1981, 1984; morello, 1979, 2003; romano, 2013, 2014, 2016, 2018a; romano et al., 2016), and even when recognized as remains of organisms they have long been explained as the result of the ‘great flood’, sent for punish the degenerate human race (vai, 2003; luzzini, 2009, 2013; romano, 2017, 2018b, 2018c). concerning huge vertebrate fossils found in the campagna romana, herodotus reports of large bones ascribed to the giant pallas found in rome (mazzella, 1591; romano & avanzini, 2019). in reference to this finds, calmet (1730) reports of the huge human skeleton found in rome that, leaning against the buildings, was as tall as the city walls. some fossil laminae of elephant molars, probably from the campagna romana (kotsakis & barisone, 2008), were preserved in the collection by michele mercati in the vatican, illustrated by giovanni maria lancisi in 1717 over a century after the death of mercati in the famous work metallotheca vaticana. kotsakis & barisone (2008) reported that the french traveller de mancony in 1644 mentioned elephant bones found in the foundations of the vatican and a hippopotamus canine discovered along the via nohttps://doi.org/10.26382/amq.2021.06 110 romano m. et al. tense urbanization, leading to the discovery of a large number of vertebrate fossil remains that were collected from the campagna romana (among others meli, 1896; ponzi, 1867, 1878; portis, 1893). the fossil remains, mostly found in alluvial deposits of the tiber river and tributaries, were later mainly referred to the middle pleistocene (e.g., ambrosetti, 1967; conato et al., 1980; di stefano et al., 1998; petronio & sardella, 1998, 1999; milli et al., 2004; marra et al., 2014; sardella et al., 2015; iannucci et al., 2021; mecozzi et al., 2021). these deposits are frequently constituted by volcanoclastic materials and are interlayered by volcanic deposits of the sabatini or colli albani volcanic districts (conato et al., 1980; milli, 1997; giordano et al., 2003; funiciello & giordano, 2008; marra et al., 2014; marra et al., 2018). these historical paleontological heritages found their way into museum collections of the ‘museo universitario di scienze delle terra (must; former museo di paleontologia), sapienza, università di roma’. in the next sections, the biographies and geopaleontological studies of prominent personalities active on the roman scene at the transition from the 19th and 20th centuries are presented. these information are crucial to understand the history of the fossil collections stored at must as well as those housed in other repository of rome and its surroundings. 2. 19th to 20th century studies the earliest publication of a fossil elephant from the “diluvial” deposits in the countryside surrounding rome at the time (porta del popolo) is due to morozzo (1802, 1803) (kotsakis & barisone, 2008). later, large mammals from the campagna romana have been described by brocchi (1814, 1820), cuvier (1834) and pianciani (1836). despite cuvier (1834) was the first to suggest that fossil vertebrates from the rome area should have been referred to different chronological phases, no others scientists during the first half of xix century provided a chronological framework for the discovered large mammal assemblages. in the second half of the nineteenth century (up to 1870), the presence of french imperial troops in rome in support to the papal states brought several french naturalists including édouard lartet (considered the founder of paleontropology), bleicher, édouard de verneuil and frère indes to analyse the continental deposits preserving fossil vertebrate remains (kotsakis & barisone, 2008), with several publications dedicated to the subject (lartet, 1858; bleicher, 1865a, 1865b, 1866, 1867; verneuil, 1865; indes, 1869, 1870, 1872). worthy of note in this context is above all the figure of frère indes for being the first to organize and systematically conduct a paleontological excavation in a cave at the top of monte delle gioie, close to ponte salario (indes, 1872; fig. 1), an excavation from which hundreds of kg of fossil bones were unearthed (kotsakis & barisone, 2008). however, in this period contributions from italian authors are also reported. ceselli (1868) published a work entitled “sopra l’arte ceramica primitiva nel lazio” (on the primitive ceramic art in latium) addressed to mentana, stored at the private collection of virgilio romano (see also segre, 2001).some of these finds ended up in the well-known collection of the kircherian museum, set up by the jesuit of the roman college athanasius kircher, and illustrated in 1709 by filippo bonanni. accordi (1976) reports that these bones and molars were correctly referred to as elephant remains, but interpreted as the bones of extant animals brought to italy from africa under antoninus pius. gregorio roisecco (1750) describes the cabinet of the prince chigi in his villa in rome, built for the abbot salvetti and later subject to renovation works by cardinal chigi (romano & avanzini, 2019). among the several curiosities and tricks of the cabinet, which included “the corpse of a queen of egypt, well preserved embedded in many bands, and explanation of her origins”, giant bones are also reported, probably coming from the roman area, however unfortunately lost with the rest of the collection. pianciani in 1817 describes remains of quadrupeds from the territory of viterbo in deposits of volcanic origin, with bones represented by shoulder blades, femora and five vertebrae founded for the first time in 1688 at vitorchiano, and interpreted as bone of giants on the base of their huge size (romano & avanzini, 2019). the author is not surprised by this kind of preservation, since similar association between volcanic deposits and vertebrate fossil bones have been already reported near the ‘basilica di san paolo’ at ostiense in rome, embedded in pozzolans and tufaceous deposits (portis, 1900, romano & avanzini, 2019; mecozzi et al., 2020). according to kotsakis & barisone (2008) the first real scientific contribution on mammal bones from the campagna romana dates back to the beginning of the nineteenth century, with the contributions by morozzo (1802, 1803), which reports the discovery of a fossil elephant from the “diluvial terrains” outcropping just out of ‘porta del popolo’ in rome. the teeth of this specimen were then subjected to chemical analysis by morichini (1803, 1805), discovering for the first time the presence of fluorine in the animal world, including humans (see also clèrici, 1932; kotsakis & barisone, 2008). thus, for its great and peculiar geodiversity, since the end of the 19th century the stratigraphy of campagna romana focused the interest of scientists who began to study systematically the widely exposed volcanic rocks, the fluvio-lacustrine and coastal marine deposits and the fossil large mammal assemblages (mecozzi et al., 2021 and reference therein). the paleontological record from the campagna romana area are of great scientific interest for the biochronology of the middle pleistocene. in fact, the names galerian and aurelian mammal ages derive respectively from ponte galeria and aurelia statal road close to rome (ambrosetti et al., 1972; gliozzi et al., 1997), where several fossil-bearing stratigraphic sequences are exposed on quarries and excavated. since the 19th century the geo-paleontological studies on the quaternary deposits of the rome basin provided a valuable amount of information about the geological evolution of the region and to define early chronological frameworks of the large mammal assemblages. between the end of the 19th century and the beginning of the 20th century the city of rome was subjected to in 111 the attention of cavalier luigi pigorini, director of the museo delle antichità di parma (parma museum of antiquities). although much of the work is devoted to the description of ancient vases from the campagna romana, in the text ceselli reports the discovery of a large elephant tooth (fig. 2) found in 1846 near ponte mammolo in rome “nei primi depositi quaternari unitamente a delle selci scheggiate” (in the first quaternary deposits associated with chipped flints) (ceselli, 1868, p. 6). the author points out the ‘gigantic size’ of the tooth, an element that led him to give to the specimen the name ‘elephas elasmoeteron’, represented in table ii of the work. in 1870 ceselli published a work on the lithic industry of the campagna romana, titled “sunto della memoria sopra gli studi paleontologici del bacino di roma e sue adiacenze” (summary of the memory on the paleontological studies of the rome basin and its adjacencies). ceselli reports the discovery of flint worked by humans in quaternary deposits near ponte mammolo, monte sacro, tor di quinto, ponte molle, acquatraversa and magliana in rome, “mixed”, as the author writes, to the teeth and bones of ursus speloeus, jena speloea, elephas antiquus, e. meridionalis, e. primigenius and e. elasmoreteron. ceselli again in 1872 published the contribution entitled “hippopotamus dactyliotus specie nova”. in the work, the author reports and describes a hippo fossil upper canine from quaternary deposits outcropping at ponte mammolo, where other remains were referred to “jena-spoelea dell’ursus-spocleous dell’elephasantiquus (falc.), elephas elasmoreteoron (nobis), elephas-africanus etc. etc.” (ceselli, 1872, p. 6). according to ceselli, the tooth shows such differences from those already described to justify the erection of a new species. the author briefly reconstructs the history of hippopotamus studies starting from the first hints in herodotus, aristotle, diodorus of sicily and pliny the elder, even if the first true description can be traced back to 1603 by the italian surgeon federico zerenghi, in a text remained largely unknown until a rediscovery by buffon (ceselli, 1872). according to ceselli, whether the presence of more than one species of extant hippos remains highly doubtful, it is almost certain that in the past several species must have existed as evidenced by the differences in the bone material (especially teeth characters) recovered in quaternary terrains. in the text ceselli provides the diagnosis for the new species in latium, stressing the differences in the canine he considered significant and underlining how “nei terreni quaternari della campagna romana la specie più abbondante è l’hippopotamus -major di cuv.” (in the quaternary terrains of the campagna romana, hippopotamus major cuv. is the most abundant species. francesco anca (1872) deals with the elephant fossil teeth observed in the rich paleontological collection the quaternary paleontological research in the campagna romana (central italy) at the 19th-20th century transition: historical overview fig. 1 geographical location of the fossiliferous deposits of rome. 1-aventino; 2-batteria nomentana; 3-boccea; 4campidoglio; 5-campo di merlo; 6-casal dé pazzi, ponte mammolo; 7-castro pretorio; 8-cava nera molinario; 9-monte celio; 10-fondamenta bnl, pincio, quirinale; 11-gra km 2; 12monte antenne; 13-monte delle pliche; 14-monte mario; 15monte sacro; 16-monte verde; 17-monti della farnesina; 18parioli; 19-ponte molle; 20-porta cavalleggeri; 21-porta flaminia; 22-porta pia, porta salaria; 23-prati fiscali; 24-redicicoli; 25 -sant’agnese; 26-san paolo; 27-saccopastore; 28-sedia del diavolo; 29-tor di quinto; 30-via aurelia; 31-via cassia; 32-via del tritone, via nazionale; 34-via ostiense; 35-via portuense; 36-vigna san carlo; 37-vigne torte; 38-villa chigi. fig. 2 elephant tooth found in 1846 near ponte mammolo in rome, figured and briefly described by ceselli in 1868 (modified from ceselli, 1868). of the reale università di roma (royal university of rome), accompanied by its director prof. ponzi, senator of the kingdom. as reported by the author, the remains, largely represented by elephant teeth found isolated, came from the deposits of the tiber and aniene rivers. the purpose of the work was a comparison of the remains with those already described from sicily in collaboration with his friend prof. giorgo gaetano gemmellaro, and for this purpose he chose various teeth of elephas antiquus from the fluvial deposits of monte pincio in rome and from the conglomerates of ponte molle. using the dental progression proposed by falconer for elephants classification, anca argues that the material should be referred to ‘elephas africanus’, even if, as reported by the author, ponzi had strong doubts about such an interpretation. to resolve the issue, anca realized cross sections of the teeth (fig. 3) which, according to the author, show without any doubt that “tra i fossili romani insieme agli elefanti primigenio, antico, e meridionale v’ha altresì l’africano, che prima si credeva abitatore solo della sicilia, ma che oggi dobbiamo ammetterlo diffuso in tutta l’italia meridionale” (among the roman fossils together with the primeval, ancient, and southern elephants there is also the african one, which was previously believed to be an inhabitant only of sicily, but which today we must admit is widespread throughout southern italy) (anca, 1872, p. 354). according to anca, these elements would be evidence supporting the hypothesis that the modern african elephant derives from the southern one 112 romano m. et al. (‘meridionale’), as demonstrated by the close affinity of the teeth characters. 2.1. giuseppe ponzi (1805-1885) the second half of 19th century was characterized by the studies and the activity of giuseppe ponzi (fig. 4). at the beginning of his career, ponzi was a doctor, graduating in medicine in 1829. thanks to his study, ponzi participates as a medical officer in the defence of rome during the french siege of 1849 in the period of the roman republic. his military efforts for the defence of rome as an officer of the papal guard continued in both 1867 and 1870 for the well-known ‘breccia di porta pia’ (breach of porta pia). despite the prominent positions within the papal states, and connections with the curia, he managed to adapt quickly to the political changes that followed the annexation of rome to the kingdom of italy (argentieri, 2015). his university career started in 1832, as a collaborator in the field of anatomy with the zootomy and zoology cabinet, where gained the chair of comparative anatomy and zoology only during the 1838. over and above the scientific contribution, ponzi held positions of extreme importance, both locally, as municipal councillor in 1871, and national, as a senator from 1870. he was president of the accademia dei lincei (lincean academy) from 1871 to 1874, member of the commission for the reclamation of the campagna romana (1871), member of the reale comitato geologico d’italia (royal geological committee of italy) from 1871, chairman of the commissione per i materiali edilizi d’italia (commission for building materials of italy) and president of the club apino italiani (italian alpine club, cai) from 1873 to 1875. he was also a member of several academies, among which the accademia dei nuovi lincei (academy of the new lincei) from 1848, accademia nazionale delle scienze (national academy of sciences) in 1875, corresponding member of the istituto lombardo di scienze e lettere (lombard institute of sciences and letters) of milan from 1876, member of the società italiana delle scienze, detta dei xl (italian society of sciences, known as the xl) and, internationally, a member of the société géologique de france fig. 3 elephas molars from top view and in section described and figured by anca in his work published in 1872 (modified from anca, 1872). fig. 4 historical marble bust of giuseppe ponzi, exhibited at the must, university of rome (photo by alessio argentieri). the quaternary paleontological research in the campagna romana (central italy) at the 19th-20th century transition: historical overview 113 (geological society of france) and of the geological society of london. the 1854 was a crucial year for his life, since he was assigned the teaching position of mineralogy at the sapienza, university of rome. shortly thereafter, pope pius ix founded the geology chair at the roman archiginnasio, period when this teaching was separated from the chair in mineralogy for the first time. ponzi holds both professorships, in particular that of geology until the end of his career and that of mineralogy until 1873. in 1873, the scuola d’applicazione degli ingegneri di roma (application school of engineers of rome) was established by royal decree, where ponzi holds the position of professor of geology, geognosy and mineralogy. from a paleontological viewpoint, the greatest merit of ponzi was the foundation of the geology and palaeontology museum and the geology cabinet at the sapienza, university of rome during the 1873. at first, the museum hosted the mineralogical collections of the former mineralogy museum that ponzi yet directed, but these were quickly enriched from donations, such as that of the turin palaeontologist giovanni michelotti in 1880, and purchases (fabiani & maxia, 1953; kotsakis & barisone, 2008; argentieri, 2015). ponzi directed the museum until his death, with the help and support of his pupil romolo meli, who succeeded ponzi in 1885. after 1875, part of the collections of the famous kircherian museum also converged in the sapienza collections. in fact, at the end of the nineteenth century the original collection of the kircherian museum was already essentially dismembered and it was no longer preserved in the original seat of the roman college. in particular, following the suppression of the compagnia di gesù (society of jesus) decreed by clement xiv in 1773, the collections of the collegio romano (roman college) began to be dismembered and many specimens ended up in the collections of the plio-clemenino museum within the musei vaticani (vatican museums). subsequently in 1870, when rome became capital of the kingdom of italy, much of the ecclesiastical property were expropriated by the unitary state and in the collegio romano (roman college) were located the libreria nazionale centrale (national central library) and the liceo ginnasio visconti (visconti gymnasium-lyceum). in addition to the foundation of palaeontology and geology museum, ponzi was the first scientist that systematically and carefully studied the campagna romana, from the forties of the nineteenth century, starting from classical studies by italian naturalists such as gian battista brocchi and scipione breislak. ponzi proposed innovative modern approaches to the realization of the geological cartography (fig. 4; argentieri, 2015). for these innovative elements, and for the systematic character in the analysis of the roman territory, ponzi is rightly considered as the forefather or founder of the roman geological school. based on the field survey conducted under the papacy of gregory xvi between fig. 5 ponzi g. (1874), ‘carta geologica per servire alla storia dei vulcani del lazio in storia dei vulcani laziali roma’: salviucci, 1875. cartographic collections of the ispra library. autographed miscellany by the author (courtesy of ispra library). 114 romano m. et al. fig. 7 original label and felid femur and ulna found at ponte molle form the collection of giuseppe ponzi preserved at must, university of rome. fig. 6 original label and canid lower hemimandible fragment found at ponte molle (rome) form the collection of giuseppe ponzi preserved at must, university of rome. 1837 and 1846, and using gaetano spinetti's chorographic map of the papal state, ponzi produced a very important document, the geological map of the papal state at 1: 296,000 scale, which can be considered a milestone for the geological-cartographic representation for central italy (argentieri, 2015). the scientific interests of ponzi were multifaceted, he wrote about the geology of the campagna romana, the latium volcanism (fig. 5), seismic phenomena and catastrophic sinking. concerning the present historical contribution, he published several seminal papers on the palaeontology of pleistocene vertebrates from the latium region (figs. 6-7). most of these contributes immediately became reference points for decades. on the biochronology of the terrestrial mammals, it worth menioned his study on the quaternary geology of latium in 1875, in which he grouped the main geological events of the area in 3 phases: i) the earliest “epoch” that included the late miocene-pliocene sedimentary deposits, most of them of marine origin; ii) an intermediate volcano-glacial and diluvial “epoch”, followed by the younger iii) defined as post-glacial with an alluvial and a modern “epoch” (ponzi, 1875). moreover, in 1878 ponzi published a very important article about the subappenine fossil bones, with two faunal complexes considered: an older, preglacial one referable to the pliocene, and a younger post-glacial quaternary one (ponzi, 1878). such a general framework was widely accepted and used for decades. 2.2. giuseppe augusto tuccimei (1851-1915) tuccimei (fig. 8) earned several diploma, becoming a doctor in medicine, natural sciences and canon law. after just a few years of practicing, he left the medical profession, devoting himself to his greatest passion, the natural sciences, enrolling again in courses at sapienza, university of rome, and earning a degree in natural sciences in july 1876 (meli, 1916). the degree thesis on geo-palentological topics was entitled “fossili della sabbie gialle plioceniche di acquatraversa sulla via cassia, a 5 km da roma” (fossils from the pliocene yellow sands of acquatraversa on the via cassia, 5 km from rome), based both on fossils collected directly by himself and on specimens made available by romolo meli from his private collection of fossils from monte mario and surroundings (meli, 1916). son of a well-known lawyer of the apostolic tribunal of the roman rota, and with a mother descending from an illustrious roman family, tuccimei grew up in an environment closely linked to the roman pontiff and the catholic church; a social and cultural context that also influenced the author's thought and scientific activity. for his charisma, dedication, and fervour with which he carried out his ideas, tuccimei held several prominent positions, including president for the section of natural sciences of the accademia pontificia dell'immacolata concezione (pontifical academy of the immaculate conception) in 1880, vice president of the natural sciences section of the società cattolica italiana per gli studi scientifici (italian catholic society for scientific studies) in 1899, founding member of the società zoologica italiana (italian zoological society) in 1892, and of società geologica italiana (italian geological society), where he held the role of secretary for the 18871889 period and in 1893, and the position of archivist for years 1884-1886 and 1890-1892. he was also a member of the pontificia accademia romana de' nuovi lincei (pontifical roman academy of the new lincei) from 1883 and of the società storica volsinese (volsinese historical society) in 1890, member of several academies including the reale accademia valdarnese del poggio di montevarchi (royal valdarnese academy of poggio di montevarchi), accademia dell’arcadia (academy of arcadia), the reale accademia francesco petrarca di arezzo (royal francesco petrarca academy of arezzo), accademia di religione cattolica romana (academy of roman catholic religion) (1896) and of the reale accademia degli zelanti di acireale in sicilia (royal academy of the zealous of acireale in sicily) (1893). internationally, in 1893 he was also a corresponding member of the zoological society of belgium and a member of the geological society of belgium. he taught in the philosophy faculty of the pontificia università lateranense (pontifical lateran university) and several roman high schools, and he was one of the major opponent of the spread of the darwinian theory of evolution in italy. in the field of natural sciences he wrote on various topics including entomology, although his interest was the quaternary paleontological research in the campagna romana (central italy) at the 19th-20th century transition: historical overview 115 fig. 8 photo of giuseppe tuccimei (gnu free documentation license). soon catalysed by geology and palaeontology. in 1880 he published his first geological work entitled “i colli pliocenici di magliano-sabino” (the pliocene hills of magliano-sabino), with description of the deposits cropping out on the left bank of the tiber valley and with an illustration and description of the fossil molluscs personally collected. several geological and paleontological works followed, especially in the sabina area north of rome, with structural-sedimentological contributions such as “sulla struttura dei terreni che formano la catena di fara in sabina” (on the structure of the terrains that form the fara in sabina chain) published in 1883, “il sistema liassico di roccantica e i suoi fossili” (the liassic system of roccantica and its fossils) of 1887, “note stratigrafiche sopra la formazione secondaria dei monti sabini” (stratigraphic notes on the secondary formation of the sabine mountains) published in 1890, but he also wrote about karst phenomena in the region “sopra le cavità naturali dei monti sabini” (on the natural cavities of the sabine mountains published in 1886), and phenomena related to bradyseisms (“bradisismi pliocenici della regione sabina”; pliocene bradyseisms of the sabine region, published in 1888). as far as the present contribution is concerned, he also dealt extensively with pliocene and pleistocene vertebrate faunas, with several papers including “il villafranchiano nelle valli sabine e i suoi fossili caratteristici” (the villafranchian in the sabine valleys and its characteristic fossils) published in 1889, “rinvenimento di avanzi di elephas meridionalis nesti, nel pliocene di montoro” (discovery of remains of elephas meridionalis nesti, in the pliocene of montoro) of 1890, “resti di arvicola nel pliocene lacustre della sabina” (remains of arvicola in the lacustrine pliocene of sabina) of 1893, “il villafranchiano e l’astiano nella valle tra i corniculani e i lucani” (the villafranchian and the astian in the valley between the corniculani and the lucanians) published in 1895, “sopra alcuni cervi pliocenici della sabina e della provincia di roma” (on some pliocene deer of sabina and the province of rome) of 1898, “sopra alcune ossa fossili di cervo trovate sulla via aurelia” (on some fossil deer bones found on the via aurelia) of 1899. as a matter of fact, by recognizing the characteristic fauna, tuccimei (1889) was the first to introduce the villafranchian stage in central italy, a continental chronostratigraphic unit previously proposed by pareto (1865) in piedmont. tuccimei (1889, 1895) considered the vertebrate-bearing villafranchian sediments as pliocene in age and overlying, by an angular unconformity, astian marine deposits, a theory disproved in those years by clèrici (1895d) who, conversely, recognized the lateral continuity between astian and villafranchian sediments (see also girotti & mancini, 2003). an interesting contribution was “alcuni mammiferi fossili delle provincie umbra e romana” (some fossil mammals from the umbrian and roman provinces) (tuccimei, 1891) which earned him the prize from the ministry of education, on the special proposal of the accademia reale dei lincei (royal academy of the lincei) (meli, 1916). in the contribution, tuccimei describes the remains of mammuthus meridionalis and 116 romano m. et al. mastodon arvernensis found in the land of the marquis patrizi in 1857 at nera montoro, hyppopotamus major, rhinoceros etruscus, equus stenonis from the farfa valley, the remains of castor fiber founded in sabina and of elephas antiquus from deposits exposed along the tiber valley. 2.3. other personalities the transition from 19th to 20th century was characterized by several discoveries and studies. the base of data of large mammal faunas increased thanks to the work of terrigi (1883), de angelis d’ossat (1895), napoli (1907, 1911), rellini (1916), battaglia (1918) and neviani (1926). the most active personalities during the transition between the two centuries were: romolo meli, enrico clèrici and alessandro portis (kostakis & barisone, 2008). to these authors we owe a truly substantial number of studies and works on pliopleistocene vertebrates from the campagna romana, with contributions ranging from simple reporting of fossil remains found during excavations or during purely geological works, up to systematic review works on entire groups. 2.4. romolo meli (1852-1921) romolo meli (fig. 9) dedicate his studies and research to different topics. he obtained his ph.d. in philosophy in 1870, the diploma in math in 1872 and fig. 9 photo of romolo meli (from https://www.socgeol.it/ n2642/romoli-meli-roma-23-aprile-1852-1-gennaio-1921.html). the diploma as a civil engineer and architect at sapienza, university of rome in 1874. however, meli soon abandoned these subjects to devote himself to geology, first as assistant in 1875, and later obtaining a free lecturer in geology in 1881. he taught mineralogy and geology at the istituto tecnico leonardo da vinci (leonardo da vinci technical institute) in rome since 1883, mineralogy and applied geology at the reale scuola d’applicazione degli ingegneri di roma (royal school of application of engineers in rome) since 1885, getting earlier a permanent professor role in 1904 and later full professor position in 1912 (argentieri, 2009; fig. 10). at the same time, he continued teaching mineralogy and geology in the technical institute. as aforementioned, at the death of his master ponzi, meli succeeded as director of the geology cabinet and interim director of the geological and paleontological museum of the sapienza, university of rome, positions he held until 1888. among the several public roles covered by meli during his life, it worth mentioned his position as a member of the consiglio sanitario provinciale di roma (provincial health council of rome) (1890-1901 and 1907-20) and member of the regio comitato geologico (royal geological committee) (1918) (argentieri, 2009). in addition to be a founding member of the società geologica italiana (italian geological society), meli invested so many effort in the society, where he held the roles of archivist (1882-1883, 1887-1889, 1893-1899), secretary (1884-1886, 1890-1892), councillor (19001902), vice president (1903) and president (1904). he was also an active member of the società geografica reale (royal geographic society) and of the società italiana di storia critica delle scienze mediche e naturali (italian society for the critical history of medical and natural sciences), whereby was also vice president; meli had also an important role for the società romana per gli studi zoologici (roman society for zoological studies, afterwards italian zoological society), first taking part in the foundation, later holding the position of councillor and vice-president from 1896. the interest of meli embraced a well-diversified aspects of natural sciences, with topics ranging from fossil and living malacology and vertebrate, geology, stratigraphy, petrography, mineralogy, study of meteorites, as well as in the archaeological, philological and historical-bibliographic fields (argentieri, 2009). despite the multidisciplinary approach and the wide range of topics covered, what makes meli worthy of mention for the present contribution are his works focused on the geological, paleontological and stratigraphic analysis of quaternary deposits of latium region, with particular regard to the campagna romana. one of the main contribution was the work on the exceptional discovery of the remains of a fossil vulture in the vulcanites of the tuscolani mountains, with the contribution published in 1889 with the title “sopra i resti fossili di un grande avvoltoio (gyps) racchiuso nei peperini laziali” (on the fossil remains of a large vulture (gyps) enclosed in the peperini laziali) (manni et al., 2003; iurino et al., 2014). between 1881 and 1918, meli conducted numerous studies on the vertebrates of campagna romana, with a vast production on the remains of elephants, hippos, bovids, rhinos, equids, cervids, suidae, canids, bears, hyenas, birds, from outcrops on the via flaminia (cava bertazzi, melafumo, right bank of the tiber), aventino (rome), villa pamphilj (rome), church of s. silvestro (via del quirinale, ro the quaternary paleontological research in the campagna romana (central italy) at the 19th-20th century transition: historical overview 117 fig. 10 field trip conducted by romolo meli on may 17, 1908 on the beach of nettuno, with the engineering students of the royal application school of rome (courtesy of ispra library). see also meli r. (1896). fig. 11 photo of enrico clèrici (from neviani, 1938). ma), ex-convent of san pietro in vincoli (rome), foundations of the national bank building (‘marne d’acqua dolce del quirinale’, rome), sedia del diavolo (via nomentana), monte mario, tor di quinto, magliana (right bank of the tiber; via portuense; campo di merlo; monte delle piche), via della pisana (contrada bravetta, rome), batteria nomentana (left bank of the aniene), mostacciano (far out of porta san paolo), ponte buttero (via laurentina, roma), frascati (via anagnina), anzio, nettuno (coast of foglino), amaseno valley (piperno, pontini mountains), cava della catena (s. angelo, terracina), vallinfreda (turano basin), gallese (orte), s. quirico (sugano, orvieto) (meli, 1881a, 1881b, 1882, 1886, 1889a, 1889b, 1891a, 1891b, 1894a, 1894b, 1895, 1897, 1908, 1918). 2.5. enrico clèrici (1862-1938) enrico clèrici (fig. 11) studied engineering and graduated at sapienza, university of rome in 1888. in 1892 he earned the bachelor degree in natural sciences at sapienza, university of rome. engineering and geology were in fact the disciplines that involved him during his entire life. the engineering represented his stable work between 1885 and 1915, teaching electrotechnics in the evening school ‘galileo ferraris’ for the artillery of the rome municipality. his first teaching in mineralogy and geology was at the school of the experimental agricultural institute of perugia between 1896 and 1899. he obtained the title of geology professor in 1902 at sapienza, university of rome, holding the chair in geology in the same university between 1928 and 1934. in addition to teaching, clèrici worked in the agriculture, industry and trade ministry, becoming general director in 1930. clèrici has also held other positions including: meritorious member (‘socio benemerito’) and secretary of the società geologica italiana (italian geological society) for twenty-three years; member of the regio comitato geologico (royal geological committee); corresponding member of the pontificia accademia delle scienze (pontifical academy of sciences); member of the pontificia accademia tiberina (pontifical tiberine academy) of which he was councillor; member of the comitato nazionale geodetico e geofisico (national geodetic-geophysical committee) and representative for italy at the international conference in bern for the protection of intellectual property (for a more complete biography see fornaseri, 1982). in his more than 170 publications, clèrici treated and discussed several geological, paleontological and mineralogical aspects. a common thread of his researches was the rigorous mathematical and physical approach, combining both empirical laboratory experiences and direct observations in the field. for clèrici, practical work, both in laboratory and in the field, represented a crucial moment for teaching and to transfer to students his passion and devotion to geology and palaeontology. worthy of note is the invention of the socalled ‘soluzione di clèrici’ (clèrici's solution) or ‘liquido pesante di clèrici’ (heavy liquid of clèrici), a mixture in water of thallium formate and thallium malonate useful for the separation of minerals and presented on the 118 romano m. et al. rendiconti della regia accademia dei lincei in 1907 with the contribution titled “preparazione di liquidi per la separazione dei minerali” (preparation of liquids for the separation of minerals) (clèrici, 1907). thanks to this research, clèrici became famous around the world, and received a diploma of honor from the international congress of limnology held in rome in 1929. much of the research work in geology was conducted by clèrici on the analysis of the geological structure of the quaternary deposits in the campagna romana and in campania. neviani (1938) reports that clèrici knew the latium region ‘point by point’, thanks to the innumerable field trips conducted as soon as he had the opportunity, riding his inseparable bicycle “che gli permetteva raggiungere lontane località in tempo relativamente breve; e più ancora di penetrare in luoghi di non facile accesso ad altri veicoli, e nel contempo trasportare notevole quantità di piccolo campioni” (“which allowed him to reach distant locations in a relatively short time, and even more to penetrate places that are not easily accessible to other vehicles, and at the same time carrying significant quantities of small specimens”; neviani, 1938, p. 125). his study deeply contributed to the knowledge of fossil diatoms, describing several species for the first time (clèrici, 1893, 1894a, 1895a, 1895b, 1896) and mapping the deposits of the campagna romana preserving this kind of fossils (“carta dei giacimenti diatomiferi dei dintorni di roma”(map of the diatomaceous deposits around rome) published in 1935 on the bollettino della società geologica italiana (bulletin of the italian geological society). one of the principal work conducted by clèrici was published in 1888 in the bollettino della società geologica italiana (bulletin of the italian geological society), entitled “sulla corbicula fluminalis dei dintorni di roma e sui fossili che l’accompagnano” (on the corbicula fluminalis around rome and on the associated fossils). here, he described the stratigraphical successions of acquatraversa, sedia del diavolo and monte verde, (outcrops today destroyed by the urbanization), and the specimens directly collected, as well as those from the university geological institute collections and private collection of romolo meli (neviani, 1938). in a later work published in 1891, focused on the description of the castor fiber and elephas meridionalis, clèrici went back to what he had reported about the corbicula fluminalis. in the text the author deepens and clarifies the relationships between the fossil fauna and the formations referred to him to ‘the glacial period’, in response, always with polite tones, to the critical observations and points raised on the topic by tuccimei. his contribution to the study of quaternary of latium was not limited to diatoms, flora and malacofauna; he published many works on plio-pleistocene vertebrate remains of campagna romana and central italy, with contributions on elephants, mastodons, rhinos, tapirs, hippos, bears, felines, hares and equids (clèrici, 1887a, 1887b, 1888, 1891, 1892, 1894b, 1894c, 1894d, 1895c, 1906, 1926, 1931). the multidisciplinary approach was a key aspect in the clèrici’s research, that pushed him to analyse the fossil not as an mere object but as a pawn of a broader paleoenvironmental context. 2.6. alessandro portis (1853-1931) alessandro portis (fig. 12), after his classical studies, graduated in natural sciences in 1875 at the university of turin. after graduating, he spend a period abroad with the aim of deepening some palaeontological and geological aspects and topics. during this period portis was first at göttingen, and then he move to munich, basel and paris, coming back in italy when he got the position of free lecturer in palaeontology at the university of turin starting in 1879. in 1881, he was temporarily assumed as “museum staff” of the university of bologna, where he realized the first edition of the bibliographie géologique et paléontologique de l’italie and the guide aux collections de l’institut de géologie et de paléontologie à bologne under the direction of giovanni cappellini and in collaboration with carlo fornasini (pantaloni, 2016). an important aspect of portis’s work is represented by his activity as a surveyor geologist started in 1881 with several stratigraphical contribution on argentera, mount tabor (piedmont), maritime alps and the province of turin (for a more exhaustive list of production for those years see, pantaloni, 2016). for three years (1884-1886) portis was the curator at the geology museum of turin, a period during which he continued his study on vertebrate palaeontology. papers worthy of note are his contribution on fossil amphibians (portis, 1885), and the “catalogo descrittivo dei talassoterii rinvenuti nei terreni terziari del piemonte e della liguria” (descriptive catalogue of the thalassoterii found in the tertiary terrains of piedmont and liguria). the latter can still be considered a reference text as a basis for classification for this fossil group (pantaloni, 2016). the central and innovative work on chelones and thalassotherii earned portis a prize from the turin academy of sciences in 1885. in 1886 portis obtained the chair of geology and mineralogy of the scuola degli ingegneri di roma (school of engineers of rome), but the turning point in his career arrived in 1888, when on the death of ponzi, he was called to cover the chair of geology and palaeontology of the institute of geology of sapienza, university of rome, position held until 1927. portis is considered one of the founding members of the società geologica italiana (italian geological society), since he attended the ii international geological congress of bologna in 1881, participating in the founding session of the society, of which he was then president in 1908. the recognition of scientific skills in the international field is demonstrated by the fact that he was appointed a member of the deutscher geologischer gesellschaft (german geological society), of the societé géologique de belgique (geological society of belgium) and of the societé royale des sciences of liegi (royal society of sciences of liège). among the youth awards for his research is worthy of mention the award with gold medal from the george iii foundation in hanover, for the contribution on fossil batrachians from the kimmeridgian of hannover, studied by portis during his stay at the geo-paleontology institute of göttingen, and a special grant for the printing and publication of the same work from the prussian ministry of cult (martelli et al., 1932). portis had an important role for the palaeontology museum of sapienza, university of rome, enriching conspicuously both the collections (especially the paleontological ones) and the institute's library, one of the richest at the time on paleontological topics. portis can be considered the founder of a real roman school of geologists-palaeontologists which saw, among its most brilliant disciples, tellini, de angelis d’ossat, checchiarispoli and cerulli-irelli (martelli et al., 1932). portis devoted himself largely to the study of the quaternary deposits of the campagna romana, in particular catalysed by numerous remains of fossil vertebrates that were found in the area (figs. 13, 14). over the years portis wrote and published numerous works on the subject, dealing with quaternary fossil remains in numerous groups, including birds, elephants, rhinos, felines, hippos, bovids, canids and the contemporaneity between palaeolithic human and some vertebrate faunas (portis, 1896a, 1896b, 1896c, 1899, 1902, 1903, 1904, 1907a, 1907b, 1907c, 1909, 1920). the geo-paleontological works and the intense studies on the campagna romana then converged in a voluminous work entitled “contribuzioni alla storia fisica del bacino di roma” (contributions to the physical history of the rome basin), a monograph consisting of several articles on both sedimentary and volcanic deposits, and several studies on the abundant quaternary fig. 12 photo of alessandro portis (from https://www. geoitaliani.it/2016/12/portis2.html). the quaternary paleontological research in the campagna romana (central italy) at the 19th-20th century transition: historical overview 119 vertebrate fauna of the roman province (portis, 1893, 1896a). still in the field of the quaternary vertebrates, in 1894 portis describes the remains of a mostly complete elephant skeleton found on the slopes of monte pisciato near riofreddo (portis, 1896b; fig. 15), accidentally found during the ploughing of a field (fabbi & romano, 2020). the fossil deposits in this case refer to the intermountain basin of oricola-carsoli, some 40 km east of rome, a depression of tectonic origin within the hydrographic basin of the turano river (sub-tributary of the tiber) and about 40 km2 wide (fabbi & romano, 2020). 120 romano m. et al. during the early-middle pleistocene the area was largely represented by a vast lacustrine environment, with deposition of the unit “limi, argille e sabbie del bosco di oricola” (silts, clays and sands of the oricola wood), with a thickness of over 200 m which represents the main filling of the basin (d’orefice et al., 2010, 2014). at first portis, relying on the preserved molars, referred the material to the species elephas meridionalis, however he was not fully convinced and satisfied with the attribution; in fact, as portis (1896a) writes the atlas vertebra and the calcaneus were very reminiscent of those of the species elephas antiquus, whereas the fibula was more fig. 13 fossil carnivores from the tuffaceous deposits of rome, described and figured by portis in his contribution published in 1907 (portis, 1907b). fig. 14 original label and rhinoceros tooth found at ponte molle (rome) from the collection of alessandro portis preserved at must, university of rome. similar to the one characterizing e. meridionalis. the specimen was subsequently studied by de angelis d'ossat (1956) which referred it to elephas antiquus, a species that appears in italy in the middle pleistocene (palombo & ferretti, 2005), an age compatible with the oricola deposits. in addition to the elephant remains, portis (1896a) also analysed the remains of rhinoceros, hippopotamus and a carnivoran coprolite from the same stratigraphic unit and from the same area. the study of the remains allowed portis to reconstruct a marshy environment of the ‘late pliocene’, characterized by the abundant presence of fossil mammal remains. as already mentioned, the deposits that returned the fossils today are referred to the early-middle pleistocene, and a revision of the material allowed to attribute the fossil remains described by portis to the species palaeoloxodon antiquus, hippopotamus cf. antiquus, stephanorhinus etruscus and pachycrocuta brevirostris (fabbi & romano, 2020). 2.7. first decades of 20th century after the period between the end of the nineteenth century and the twenties of the twentieth century, with the major contribution by ponzi, meli, clèrici and portis, the decades up to the sixties were characterized by a smaller number of works dedicated to quaternary vertebrates of the campagna romana. according to kostakis & barisone (2008) this fact would be mainly due to a decrease of scholars who devoted themselves to vertebrate palaeontology throughout italy (see also kotsakis, 2005). nevertheless, it must be taken into account the negative influence of first world war during the twenties of xx, followed by a period of political instability, which in italy continued until the advent of fascism. talking about a deep crisis of the roman geological and paleontological school, praturlon (1993) states: “siamo così entrati nel ‘900, tra un fiorire di studiosi che ampliano velocemente il quadro delle conoscenze geologiche sull’area laziale. il vento gelido della grande guerra farà purtroppo inaridire ben presto questo rigoglioso giardino” (we thus entered the 1900s, among a flourishing of scholars who rapidly broaden the framework of geological knowledge on the lazio area. the icy wind of the great war will unfortunately soon dry up this luxuriant garden). although this period is not the subject of the present contribution, we can only briefly mention that concerning the study of vertebrate fauna, the period through the second world war was characterized by the work of three central authors: gioacchino de angelis d’ossat (1865-1957), gian alberto blanc (18791966) and his son, alberto carlo blanc (1906-1960). in particular, a more detailed and updated framework will be depicted only in the 1950s by alberto carlo blanc, who developed the glacial-interglacial scheme by penck and bruckner (1909), and correlate it to the geological succession of the campagna romana with the identification of glacial erosional phases and depositional inter the quaternary paleontological research in the campagna romana (central italy) at the 19th-20th century transition: historical overview 121 fig. 15 drawing of the discovery conditions of the elephant from riofreddo (modified from portis, 1896a). glacials (blanc, 1938, 1939, 1946, 1948, 1955, 1957, 1958; blanc et al,. 1951; 1955a, 1955b). 3. critical discussion of the geopaleontological roman school the end of the 19th century represented the beginning of a revolution for the earth sciences, with exponential growth of the studies and personalities devoted to these disciplines. during this period, italy was affected by deep change, above all, the unification took place in march, 17 1861. nevertheless, the complete unification of the italian territory was reached during 1871, when rome was nominated capital of the reign. in fact, when the popular insurrection started, napoleon iii sent the french imperial troops in rome in support to the papal states; troops that occupied the city up to 1870 when the france lost the war against the prussian. at that time, the city of rome was defenceless, and therefore it was earlier conquered. what makes the french occupation crucial for geology and palaeontology studies was the presence of several french naturalists in rome, among which we must mentioned frère indes. his contribute was really important for the development of the natural research, in particular considering that the first paleontological excavation in a cave at the top of monte delle gioie, close to ponte salario, was designed and conducted exactly by indes (indes, 1872; kotsakis & barisone, 2008). unfortunately, indes left rome when french troops were recalled by napoleon iii, with no time to organize the transport of his collections. in view of this fact, it is quite impossible to quantify the exact extent of the frère indes’ collection; part of this historical material (more than 3000 specimen) is now kept in the school of san giuseppe de merode (cerilli, 2014). afterwards the unification of italy, the geology underwent a massive leap forward, when the chair in geology was instituted and the geology museum at the sapienza, university of rome was founded. initially, this museum was located in the sant’ivo locals, nearest to navona square (rome). although several paleontological, geological and mineralogical private collections converged in the geology museum of sapienza, several fossils were located in scientific cabinet of roman high schools, similarly to what happened for the frère indes’ collections. the presence of natural collections in the high school of rome had a double valence: first they play an important scientific function for teaching purposes and second in representing a repository to keep together specimens of the same collection. this situation went on for decades until the institution of the chair in palaeontology and the foundation of the palaeontology museum of sapienza, university of rome in 1928. it is worth mentioning that the città universitaria (university city), an institution that even today hosts the most of the sapienza departments, was built during 1930s and inaugurated in 1935. henceforth, the paleontological collections previously housed in the geology museum located at sant’ivo were moved in the sapienza museum, which became the principal institution where fossils from campagna romana were stored. 122 romano m. et al. the myriad of remains recovered during the end of 1800 and the first half of 1900, in addition to their great historical value, played a key role in the reconstruction of the evolution of terrestrial ecosystems during the late early to late middle pleistocene. is not merely the great abundance of collected fossil remains, but also the completeness and significance of these materials, often represented by nearly complete crania, with tusks in the cases of elephantidae, horn corns for bovidae or antlers for cervidae, along with nearly complete skeletons found in anatomical connection (palombo, 2004; kotsakis & barisone, 2007). the first biochronological scheme based on large mammals was proposed by blanc (1957), which recognized five glacial episodes: acquatraversa, cassia, flaminia, nomentana and pontina: scheme, slightly modified by ambrosetti & bonadona (1967), that represented the basis for the paleontological study on mammals from campagna romana for decades (kotsakis & barisone, 2007). in the framework of the biochronological scheme of the italian terrestrial large mammals, the campagna romana area assumes a great scientific interest, as testified by the names of two mammal ages (galerian and aurelian), by local fauna selected to instituted two faunal units (ponte galeria and torre in pietra), and by several local faunal complexes who have shed light on the terrestrial ecosystem evolution from the late early pleistocene to late middle pleistocene (e.g., ambrosetti et al., 1972; gliozzi et al., 1997; di stefano et al., 1998; petronio & sardella, 1998, 1999; palombo, 2004; kotsakis & barisone, 2007; marra et al., 2014; sardella et al., 2015; marra et al., 2018). the majority of fossils recovered during the end of 1800s and the early 1900s were accidentally recovered often during quarry activities, lacking a clear stratigraphical context and providing scarce chronological constrains (palombo, 2004). systematic palaeontological and archaeological excavations became widespread during the 1910s, adopted for the first time by blanc in the study of grotta romanelli (sardella et al., 2018, 2019). therefore, the lack of exact stratigraphical data is not surprising, and explain why the labels that accompanied these fossils (when present) reported only the bearing geological unit. another limit of the time that must be stressed is the lack of technological tools, above all camera and total station. in addition, during the systematic excavation many data were recorded on excavation diary, whereas during the geopaleontological surveys data were reported on field book. likewise, this documentation was rarely preserved, among which is worth mentioning the historical dossiers preserved at the istituto italiano di paleontologia umana (italian institute of human paleontology) and istituto italiano di preistoria e protostoria (italian institute of prehistory and protohistory). a final issue is represented by the exchange of correspondence, often used to communicate the latest research or discovery among involved scholars, but also to express a different viewpoint on some crucial aspects; these letters have been cited in several contributions in the literature, but the original documentation is often unaffordable. an important point is how to approach this lack or patchy documentation about the exact geographical and stratigraphical data. the rome basin has been deeply studied from a geological, mineralogical and sedimentological perspectives and, as a result, the evolution of the paleo-tiber river is today well-know and constrained (e.g., ambrosetti, 1967; conato et al., 1980; milli et al., 2004; marra et al., 2014). by assembling the data reported in the historical works, the label information reported on fossils and updated geological maps, generally it is possible to obtain at least the macro geological unit. thanks to the several scientific contributions on the campagna romana area, these units are wellchronologically constrained trough radiometric dating or strong stratigraphical correlations, especially based on the volcanoclastic materials produced by the sabatini or colli albani volcanic districts (conato et al., 1980; milli, 1997; giordano et al., 2003; funiciello & giordano, 2008; marra et al., 2014; marra et al., 2018). despite these data are based on indirect sources and correlations, they represent the most commonly used method to geologically contextualize the historical collections. finally, these specimens occasionally preserved sediments as patina which could cover the remain or, alternatively, as sediments that fill the natural empty or broken portion of fossils. the analysis of these associated sediments was used, for example, in the study of the partial cranium of stephanorhinus hemitoechus where the only information reported on the label is simply ‘campagna romana’; in this case the geochemical analysis of the associated pumice revealed an age approximately to 0.5 ma (pandolfi et al., 2013). as already stressed, a systematic approach for paleontological excavations was firstly applied during the 1910s, but it became common only during the second part of the 20th century. among the personalities of that time, a prominent scientist was gian alberto blanc. student of portis, g.a. blanc further developed the approach of his master, which combined the geological, stratigraphical and paleontological data on his works. g.a. blanc added a great innovation to the paleontological research, i.e. the stratigraphical data for each fossil found during the excavation (generally reported on remains). this method was immediately followed by archaeologists, but in palaeontology became commonly followed only from the beginning of the 1980. finally, last but not least, a consideration is needed about the role of women in the roman scientific community in the considered historical period. this can be related to the socio-political condition that characterised italy, and rome in particular. such a topic deserves a more accurate and specific research to be published in the next future. definitely, until 1940s the study of quaternary in the campagna romana seems to be a men’s job. cesarina cortesi was the first woman who got a degree in geological sciences at sapienza in 1938-39 (lombardi, 2015). in 1941 he wrote an article with g.a. blanc about geochemical interpretation of the quaternary deposits of grotta romanelli (blanc & cortesi, 1941). cortesi worked for decades at sapienza university. in the 1940s angiola maria maccagno (1912 -1991) started her geo-paleontological career at sapienza university first, and then at naples university. the quaternary of the rome area was investigated since 1950s by maria follieri (1932-2012), who started advanced paleobotanical studies and gave rise to a scientific school still active today. the role of these scientists need to be properly studied and presented. 4. concluding remarks the intense urbanisation which affected the city of rome during the end of 1800 and the beginning of 1900 led the discovery of a myriad of vertebrate fossils. most of these historical collections are today preserved in the must of sapienza, university of rome. other fossils were kept in the scientific cabinets of several high school of the city of rome or latium villages. these rich fossil samples, mainly referred to middle pleistocene, played a key role for the study of the evolution large mammal faunal and terrestrial ecosystem as well as for the reconstruction of the evolutionary trend of the palaeolithic human in italian peninsula. if on the one hand large part of these fossil collections lacks of both exact geographical and stratigraphical data, on the other, they represent a historical heritage which need to be preserved and promoted. this paleontological material was collected by a number of scientists, among which the most important were ponzi, tuccimei, portis, clèrici and meli. thanks to their meticulous work, the majority of the specimens are supplemented by a label, where data on collection year, author, approximate locality and preliminary description of the level in which fossils were collected, as well as the first taxonomical attribution. a comprehensive revision of fossil collections and chronostratigraphic data is needed to resume the attention of the campagna romana as laboratory for the study evolution of terrestrial ecosystems in the mediterranean area. in this project will be crucial to realize a database in which to include all fossil materials dispersed in the high schools and museums. this database can be compared with the data reported in the paleontological literature, therefore allowing to understand how many fossils were lost for science over time and how many can be recovered for new reviews and future studies. acknowledgements we are grateful to linda riti and michele macri for the help and support during the study of the fossil collection of must (museo universitario di scienze della terra), sapienza, university of rome. fabiana console is warmly thanked for providing original iconographic material form the ispra library. finally, we wish to thank the editor, ilaria mazzini, and two referees, one anonymous and marco mancini, for comments and suggestions that greatly improved the manuscript. references accordi b. (1975) contributions to history of geological sciences: paolo boccone (1633-1704) a practically unknown excellent geopaleontologist of the 17th century. geologica romana, 14, 353-359. accordi b. (1976) contributions to the history of geolo the quaternary paleontological research in the campagna romana (central italy) at the 19th-20th century transition: historical overview 123 gical sciences. illustrators of the kircher museum naturalistic collections. geologica romana, 15, 113-126. accordi b. (1978) agostino scilla, painter from messina (1629-1700), and his experimental studies on the true nature of fossils. geologica romana, 17, 129-144. accordi b. (1981) ferrante imperato (napoli, 15501625) e il suo contributo alla storia della geologia. geologica romana, 20, 43-56. accordi b. (1984) storia della geologia, zanichelli, bologna. pp. 114. ambrosetti p. (1967) cromerian fauna of the rome area. quaternaria, 9, 1-17. ambrosetti p., bonadonna f.p. (1967) revisione dei dati sul plio-pleistocene di roma. atti della accademia gioenia di scienze naturali di catania, ser. 6, 18, 33-72. ambrosetti p., azzaroli a., bonadonna f.p., follieri m. (1972) a scheme of pleistocene chronology for the tyrrhemian side of central italy. bollettino della società geologica italiana, 91, 169-184. anca f. (1872) sull’elefante africano rinvenuto fra i fossili post-pliocenici presso roma. atti della accademia nazionale dei lincei, 25, 353-356. argentieri a. (2009) meli, romolo. dizionario biografico degli italiani, 73, 289-291. argentieri, a. (con la collaborazione di pantaloni m.) (2015) ponzi, giuseppe. dizionario biografico degli italiani vol. 84., avanzini m., kustatscher e. (2016) giganti di pietra: alle radici dei miti. in: athesia spa (ed.), nani e giganti studi storico culturali di castel roncolo, fondazione castelli di bolzano, bolzano, 10, 9-41. battaglia r. (1918) le industrie e le faune pleistoceniche d’italia. rivista di antropologia, 22, 193-292. blanc a.c. (1938) il giacimento musteriano di saccopastore nel quadro del pleistocene laziale. rivista di antropologia, 32, 223-235. blanc a.c. (1939) sulla posizione della grotta del monte delle gioie nella valle dell’aniene. bollettino della società geologica italiana, 58, 133-138. blanc a.c. (1946) i reperti musteriani di saccopastore e la posizione cronologica del giacimento alla luce dei recenti ritrovamenti. atti v congresso nazionale studi romani (1937) (1946), roma, pp. 3-11. blanc a.c. (1948) notizie sui ritrovamenti e sul giacimento di saccopastore e sulla posizione del plesitocene laziale. palaeontographia italica, 42, 3-23. blanc a.c. (1955) ricerche sul quaternario laziale. iii. avifauna artica, crioturbazioni e testimonianze di soliflussi nel pleistocene mediosuperiore di roma e di torre in pietra. il periodo glaciale nomentano, nel quadro delle serie glaciali riconosciute nel lazio. quaternaria, 2, 187-200. blanc a.c. (1957) on the pleistocene sequence of rome. paleoecologic and archeologic correlations. quaternaria, 4, 95-109. blanc a.c. (1958) torre in pietra, saccopastore e monte circeo. la cronologia dei giacimenti e la paleogeografia quaternaria del lazio. bollettino della società geologica italiana, 11, 196-214. blanc a.c., tongiorgi e., trevisan l. (1951) un giaci 124 romano m. et al. mento di fauna ad ippopotamo nel quaternario antico della maglianella presso roma. atti 42a riun. soc. ital. progr. sci., 1, tivoli. blanc a.c., cova g., franceschi p., lona f., settepassi f. (1955a) ricerche sul quaternario laziale. ii. una torba glaciale, avifauna artica e malacofauna montana nel pleistocene medio-inferiore dell’agro cerite e di roma – il periodo glaciale flaminio. quaternaria, 2, 159-186. blanc a.c., lona f, settepassi f. (1955b) ricerche sul quaternario laziale. i. una torba ad abies, malacofauna montana e criosedimenti nel pleistocene inferiore di roma – il periodo glaciale cassio. quaternaria, 2, 151-158. blanc g.a., cortesi c. (1941) interpretazione geochimica delle formazioni quaternarie di grotta romanelli (terre d’otranto). iii – le sostanze umiche fossili. atti della reale accademia nazionale dei lincei. rendiconti della classe di scienze fisiche, matematiche e naturali, 7, 33-55 . bleicher m.g. (1865a) note sur une petite dent d’elephas antiquus trouvée dans le diluvium des environs de rome et renseignements sur ce diluvium. bulletin de la société géologique de france 22, 522-526. bleicher m.g. (1865b) essai d’une monographie géologique du mont-sacré. bulletin de la société d'histoire naturelle de colmar, france, 5, 147-160. bleicher m.g. (1866) sur la géologie des environs de rome. bulletin de la société géologique de france, 23, 645-654. bleicher m.g. (1867) recherches géologiques faites dans les environs de rome. bulletin de la société d'histoire naturelle de colmar, 6-7, 65-99. brocchi g. (1814) conchiliologia fossile subappennina. milano, vol. 1, pp. 240, e vol. 2, pp. 712. brocchi g. (1820) dello stato fisico del suolo di roma ed illustrazione della carta geognostica di questa città. roma, pp. 281. calmet a. (1730) il tesoro delle antichità sacre e profane. verona: dioniso ramanzini. cerilli e. (2004) un prete e un soldato per la campagna (romana): le collezioni ottocentesche di frère indes e luigi ceselli. in guidi a. (ed.) 150 anni di preistoria e protostoria in italia (studi di preistoria e protostoria), 111-116 pp. ceselli l. (1868) sopra l’arte ceramica primitiva nel lazio. roma, coi tipi del salviucci, pp. 22. ceselli l. (1870) sunto della memoria sopra gli studi paleontologici del bacino di roma e sue adiacenze. corrisp. scient. roma avanz. sci., 22, 1-7. ceselli l. (1872) hippopotamus dactyliotus dei depositi quaternari presso ponte mamolo. roma, pp. 8. clèrici e. (1887a) sopra alcuni fossili recentemente trovati nel tufo grigio di peperino presso roma. bollettino della società geologica italiana, 6, 2022. clèrici e. (1887b) sopra i resti di castori finora rinvenuti nei dintorni di roma. bollettino del regio comitato geologico, 9, 278-284. clèrici e. (1888) sopra alcune specie di felini della caverna al monte delle gioie presso roma. bollettino del regio comitato geologico, 5, 149-167. clèrici e. (1891) sul castor fiber, sull’elephas meridionalis e sul periodo glaciale nei dintorni di roma. (risposta alle osservazioni critiche del dott. tuccimei). bollettino della società geologica italiana, 10, 333-370. clèrici e. (1892) l’ursus spaeleus nei dintorni di roma. bollettino della società geologica italiana, 11, 105-110. clèrici e. (1893) sopra un giacimento di diatomee al monte del finocchio o della creta presso tor di valle. bollettino della società geologica italiana, 12, 759-821. clèrici e. (1894a) sulle diatomee fossili del suolo di roma. bollettino della società geologica italiana, 13, 17-19. clèrici e. (1894b) ulteriori notizie sopra il rinvenimento di alcuni mammiferi fossili. bollettino della società geologica italiana, 13, 97-105. clèrici e. (1894c) sul ritrovamento del castori nelle ligniti di spoleto. bollettino della società geologica italiana, 13, 199-202. clèrici e. (1895a) sopra un giacimento di diatomee presso viterbo. bollettino della società geologica italiana, 14, 96-98. clèrici e. (1895b) sopra un nuovo giacimento diatomifero preso orvieto e sui blocchi di argilla marina contenuti nei materiali vulcanici sostenenti questa città. bollettino della società geologica italiana, 14, 294-296. clèrici e. (1895c) rinvenimento di resti di tapiro nella lignite di spoleto. bollettino della società geologica italiana, 14, 296-297. clèrici e. (1895d) presentazione di fossili della regione fra monti cornicolani e lucani, e digressione sulla pretesa epoca villafranchiana di detta regione. bollettino della società geologica italiana, 14, 315 -320. clèrici e. (1896) rinvenimento di diatomee nei dintorni di montalto (prov. di roma). bollettino della società geologica italiana, 15, 477-479. clèrici e. (1906) delle sabbie fossilifere di malagrotta sulla via aurelia. rendiconti della regia accademia dei lincei, 15, 133-136. clèrici e. (1907) preparazione di liquidi per la separazione dei minerali. atti della regia accademia dei lincei, 16, 187-195. clèrici e. (1926) resti di ippopotamo a monte antenne. bollettino della società geologica italiana, 45, 118-122. clèrici e. (1931) presentazione di argilla e fossili palustri e di molare di rhinoceros mercki. bollettino della società geologica italiana, 50, 33. clèrici e. (1932) le geologia e la paleontologia in roma e nel lazio. in “le scienze fisiche e biologiche in roma e nel lazio”, istituto di studi romani, (estr.), roma. pp. 33. clèrici (1935) carta dei giacimenti diatomeiferi dei dintorni di roma. bollettino della società geologica italiana, 54, 223-228. conato v., esu d., malatesta a., zarlenga f. (1980) new data on the pleistocene of rome. quaternaria, 22, 131-176. cuvier g. (1834) recherches sur les ossemens fossiles, où on rétablie les caractères de plusieurs animaux dont les révolutions du globe ont détruit les espèces. 4ème éd., vol. 1, paris. de angelis d’ossat g. (1895) il rhinoceros (coelodonta) etruscus falc. nella provincia romana. atti della accademia gioenia di scienze naturali in catania, 9, 1-9. de angelis d’ossat g.(1956) notevoli denti elefantini fossili nella valle dell’aniene. atti e memorie della società tiburtina di storia e d’arte, 28-29, 165174. di stefano g., petronio c., sardella r. (1998) biochronology of pleistocene mammal faunas from rome urban area. il quaternario italian journal of quaternary sciences, 11, 191-199. d’orefice m., dramis f., graciotti e., graciotti r., soligo m. (2010) evoluzione geomorfologica quaternaria della conca di carsoli (aq). il quaternario italian journal of quaternary sciences, 23, 55-74. d’orefice m., graciotti r., chiessi v., censi neri p., morri a., roma m., falcetti s. (2014) la conca intermontana di oricola-carsoli (aq): caratteri geologici, geomorfologici e applicativi. memorie descrittive della carta geologica d’italia, 91, pp. 138. fabbi s., romano m. (2020) alessandro portis e l’elefante di riofreddo (rm). memorie descrittive della carta geologica d’italia, 106, 107-114. fabiani r., maxia e.c. (1953) l’istituto e i musei di geologia e palentologia. pubblicazione istituto di geologia e paleontologia di roma, 9, 1-31. fornaseri m. (1982) clèrici, enrico. dizionario biografico degli italiani, vol. 26. funiciello r., giordano g. (2008) note illustrative della carta geologica d’italia alla scala 1:50.000. foglio 374 roma. apat, dipartimento difesa del suolo, servizio geologico d’italia, pp. 158. funiciello r., heiken g., de rita d., parotto m. (2006) i sette colli. guida geologica a una roma mai vista. raffaello cortina editore, milano, pp.328. giordano g., esposito a., de rita d., fabbri m., mazzini i., trigari a., rosa c., funiciello r. (2003) the sedimentation along the roman coast between middle and upper pleistocene: the interplay of eustatism, tectonics and volcanism – new data and review. il quaternario italian journal of quaternary sciences, 16(1bis), 121-129. girotti o., mancini m. (2003) plio-pleistocene stratigraphy and relations between marine and nonmarine successions in the middle valley of the tiber river (latium, umbria). il quaternario italian journal of quaternary sciences, 16(1bis), 89-106. gliozzi e., abbazzi l., argenti p., azzaroli a., caloi l., capasso barbato l., di stefano g., esu d., ficcarelli g., girotti o., kotsakis t., masini f., mazza p., mezzabotta c., palombo m.r., petronio c., rook l., sala b., sardella r., zanalda e., torre d. (1997) biochronology of selected mammals, molluscs and ostracods from the middle pliocene to the late pleistocene in italy. the state of the art. rivista italiana di paleontologia e stratigrafia, 103, 369-388. heiken g., funiciello r., de rita d. (2005) the seven the quaternary paleontological research in the campagna romana (central italy) at the 19th-20th century transition: historical overview 125 hills of rome. a geological tour of the eternal city. princeton university press, pp. 245. iannucci a., mecozzi b., sardella r. (2021) large mammals from the middle pleistocene (mis 11) site of fontignano 2 (rome, central italy), with an overview of “san cosimato” assemblages. alpine and mediterranean quaternary, 34(1), 155-164. indes f. (1869) lettre sur la formation des tufs et sur une caverne à ossements des environs de rome. bulletin de la société géologique de france, 26, 11-28. indes f. (1870) deuxième 36etter sur la formation des tufs des environs de rome. bulletin de la société géologique de france, 27, 410-425. indes f. (1872) paléontologie quaternaire de la campagne romaine. mat. hist. prim. homme, 7, 553563. iurino d.a., bellucci l., schreve d., sardella r. (2014) exceptional soft tissue fossilization of a pleistocene vulture (gyps fulvus): new evidence for emplacement temperatures of pyroclastic flow deposits. quaternary science reviews, 96, 180-187. kotsakis t. (2005) cenni di storia della paleontologia dei vertebrati in italia. in: bonfiglio l. (ed.), paleontologia dei vertebrati in italia, memorie del museo civico di storia naturale di verona, 6, 1318. kotsakis t., barisone g. (2008) cenni sui vertebrati fossili di roma. memorie descrittive carta geologica d’italia, 80, 115-143. lartet e. (1858) observations à propos des débris fossiles de divers éléphants dont la découverte a été signalée par m. ponzi, aux environs de rome. bulletin de la société géologique de france, 15, 564-569. lombardi g. (2015) – studenti e laureati in scienze geologiche a roma la sapienza dal 1936 al 2015. geoitaliani.it/2015/07/sapienza19362015.html luzzini f. (2009) flood conceptions in vallisneri’s thought. geological society, london, special publications, 310, 77-81. luzzini f. (2013) il miracolo inutile: antonio vallisneri e le scienze della terra in europa tra xvii e xviii secolo. olschki, firenze., 275. mayor a. (2000) the first fossil hunters: paleontology in greek and roman times. princeton (nj): princeton university press, 384. manni r., palombo m.r., palladino d.m. (2003) the eurasian griffon, gyps fulvus (hablizl, 1783) in the “peperini” hydromagmatic deposits of the alban hills (rome, italy); a case of exceptional preservation. geologica romana, 37, 131-133. marra f., pandolfi l., petronio c., di stefano g., gaeta m., salari. l. (2014) reassessing the sedimentary deposits and vertebrate assemblages from ponte galeria area (rome, central italy): an archive for the middle pleistocene faunas of europe. earth -science reviews, 139, 104-122. marra f., nomade s., pereira a., petronio c., salari l., sottili g., bahain j.j., boschian g., di stefano g., falguerès c., florindo f., gaeta m., giaccio b., masotta m. (2018) a review of the geologic sec 126 romano m. et al. tions and the faunal assemblages of aurelian mammal age of latium (italy) in the light of a new chronostratigraphic framework. quaternary sciences reviews, 181, 173-199. martelli a., cerulli-irelli s., clerici e. (1932) rievocazione. bollettino della società geologica italiana, 51, 20-27. mazzella s. (1591) sito et antichità della città di pozzuolo, e del suo amenissimo distretto. napoli: horatio salviani, 152. mecozzi b., iurino d.a., profico a., rosa c., sardella r. (2020) the wolf from the middle pleistocene site of ostiense (rome): the last occurrence of canis mosbachensis (canidae, mammalia) in italy. his t o r i c a l b i o l o g y . d o i : 10.1080/08912963.2020.1769090. mecozzi b., iannucci a., mancini m., sardella r. (2021) redefining ponte molle (rome, central italy): an important locality for middle pleistocene mammal assemblages of europe. alpine and mediterranean quaternary, 34(1), 131-154. meli r. (1881a) notizie ed osservazioni sui resti organici rinvenuti nei tufi leucitici della provincia di roma. bollettino del regio comitato geologico d’italia, 12, 428-457. meli r. (1881b) rinvenimento di ossa fossili nei dintorni di roma. bollettino del regio comitato geologico d’italia, 12, 580-582. meli r. (1882) ulteriori notizie ed osservazioni sui resti fossili rinvenuti nei tufi vulcanici della provincia di roma. bollettino del regio comitato geologico d’italia, 13, 260-280 and 358-368. meli r. (1886) sopra alcune ossa fossili rinvenute nelle ghiaie allivionali presso la via nomentana, al 3° chilom. da roma. bollettino del regio comitato geologico d’italia, 17, 265-280. meli r. (1889a) su’ mammiferi fossili delle ghiaje quaternarie dei dintorni di roma. bollettino della società geologica italiana, 8, 40-43. meli r. (1889b) sopra i resti fossili di un grande avvoltoio (gyps) racchiuso nei peperini laziali. bollettino della società geologica italiana, 8, 490-529. meli r. (1891a) sopra alcuni resti di mammiferi fossili nei terreni quaternari della provincia di roma. bollettino della società geologica italiana, 10, 1001-1002. meli r. (1891b) sopra alcuni resti di carnivori rinvenuti nelle ghiaie alluvionali della valle del tevere, nei dintorni di roma. bollettino della società geologica italiana, 10, 1003. meli r. (1894a) sopra una zanna elefantina a doppia curvatura rinvenuta nelle ghiaie d’alluvione dell’aniene alla batteria nomentana presso roma. bollettino della società geologica italiana, 13, 12-15. meli r. (1894b) sopra alcuni resti fossili di mammiferi rinvenuti nella cava della catena presso terracina (provincia di roma) bollettino della società geologica italiana, 13, 183-190. meli r. (1895) notizie sopra alcuni resti di mammiferi quaternarii (ossa e denti isolati) rinvenuti nei dintorni di roma. bollettino della società geologica italiana, 15, 291-296. meli r. (1896) sulla esistenza di strati di torba affio ranti entro mare, lungo la spiaggia di foglino presso nettuno nella provincia di roma. bollettino della società geologica italiana, 15, 15-36. meli r. (1897) sopra alcuni denti fossili di mammiferi (ungulati) rinvenuti nelle ghiaie alluvionali dei dintorni di roma. bollettino della società geologica italiana, 16, 187-194. meli r. (1908) rinvenimenti di denti fossili elefantini in alcune località nuove, o interessanti per la provincia di roma. bollettino della società geologica italiana, 27, 432-434. meli r. (1918) rinvenimento di resti fossili di un elefante nell’interno della città di roma. atti della accademia pontificia de’ nuovi lincei, 71, 141149. meli r. (1916) prof. comm. giuseppe tuccimei, necrologie. bollettino della società geologica italiana, 35, 89-98. milli s. (1997) depositional setting and high-freqeuncy sequence stratigraphy of the middle-upper pleistocene and holocene deposits of the roman basin. geologica romana, 33, 99-136. milli s., palombo m.r., petronio c., sardella r. (2004) the middle pleistocene deposits of the roman basin (latium, italy): an integrated approach of mammal biochronology and sequence stratigraphy. rivista italiana di paleontologia e stratigrafia, 110, 559-569. morello n. (1979) la nascita della paleontologia nel seicento: colonna, stenone e scilla. granco angeli editore, milano, 265. morello n. (2003) the question on the nature of fossils in the 16th and 17th centuries. in: vai g.b., cavazza w. (eds.) four centuries of the word geology: ulisse aldrovandi 1603 in bologna. minerva edizioni, bologna, 127-151. morichini d. (1803) analisi chimica dei denti fossili di un elefante trovato nelle vicinanze di roma. memoria di matematica e di fisica della società italiana delle scienze residente in modena, 10. morichini d. (1805) analisi dello smalto di un dente fossile di elefante e dei denti umani. memoria di matematica e di fisica della società italiana delle scienze residente in modena, 12-(2), 73-88. morozzo c.l. (1802) notice sur un squelette d’un gros animal trouvé aux environs de rome. journal de physique, de chimie, d'histoire naturelle et des arts, 54, 441-442. morozzo c.l. (1803) sopra i denti fossili di un elefante trovato nelle vicinanze di roma. memoria di matematica e di fisica della società italiana delle scienze residente in modena, 10(2), 162-171. napoli p.f. (1907) intorno alla formazione di monteverde e di alcuni fossili rinvenuti. memorie della pontificia accademia nazionale dei nuovi lincei, 25, 79-82. napoli p.f. (1911) di alcuni rinvenimenti di fossili a monteverde presso roma. memorie della pontificia accademia nazionale dei nuovi lincei, 29, 229 -231. neviani a. (1926) l’ippopotamo nella campagna romana. memorie della pontificia accademia nazionale dei nuovi lincei, 9, 27-49. neviani a. (1938) necrologia di enrico clerici. bollettino della società geologica italiana, 57(3), 121143. palombo m.r. (2004) – le mammalofaune della campagna romana: bio­cronologia, paleoambienti. ii congresso geosed, escursione precon­gresso, roma, 1-29. palombo m.r., ferretti m.p. (2005) elephant fossil record from italy: knowledge, problems, and perspectives. quaternary international, 126/128, 107136. pandolfi l., gaeta m., petronio c. (2013) – the skull of stephanorhinus hemitoechus (mammalia, rhinocerotidae) from the middle pleistocene of campagna romana (rome, central italy): biochronological and paleobiogeographic implications. bulletin of geosciences, 88(1), 51-62. pareto m. (1865) note sur la subdivision que l’on pourait établir dans les terrains de l’apennin septentrional. bulletin de la société géologique de france, 22, 210-277. pantaloni m. (con la collaborazione di argentieri a.) (2016) portis, alessandro. dizionario biografico degli italiani 85. penck a., brückner e. (1909) die alpen in eiszeitalter. tauchnitz, leipzig, pp. 1199. petronio c., sardella r. (1998) bos galerianus n. sp., (bovidae, mammalia) from the ponte galeria formation (rome, italy). neues jahrbuch für geologie und paläontologie-monatshefte, 269-284. petronio c., sardella r. (1999) biochronology of the pleistocene mammal fauna from ponte galeria (rome) and remarks on the middle galerian faunas. rivista italiana di paleontologia e stratigrafia, 105, 155-164. pianciani g.b. (1817). delle ossa fossili di magognano nel territorio di viterbo. opuscoli scientifici, tomo primo. bologna: annesio nobili pianciani g.b. (1836) di alcune ossa fossili rinvenute in roma e ne’dintorni, e conservate nel museo kircheriano. giornale arcadico, 67, 158-173. ponzi g. (1867) storia fisica del bacino di roma. ed seconda, roma, pp. 20. ponzi g. (1874) carta geologica per servire alla storia dei vulcani del lazio in storia dei vulcani laziali roma. salviucci. ponzi g. (1875) cronaca subappennina o abbozzo d’un quadro generale del periodo glaciale. atti xi congresso degli scienziati italiani, 268-346. ponzi g. (1878) le ossa fossili subappennine dei dintorni di roma. memorie della regia accademia dei lincei, 2, 709-736. portis a. (1885) catalogo descrittivo dei talassoterii rinvenuti nei terreni terziarii del piemonte e della liguria. memorie della regia accademia delle scienze di torino, 37, 247-365. portis a. (1893) contribuzioni alla storia fisica del bacino di roma e studii sopra l’estensione da darsi al pliocene superiore. vol. i, roma, pp. 293. portis a. (1896a) contribuzioni alla storia fisica del bacino di roma e studi sopra l’estensione da darsi al pliocene superiore. vol. 2 parti quarta e quinta, roux frassati, torino, pp. 513. the quaternary paleontological research in the campagna romana (central italy) at the 19th-20th century transition: historical overview 127 portis a. (1896b) il cigno fossile nelle vicinanze di roma. rivista italiana di paleontologia, 2, 158162. portis a. (1896c) anomalie riscontrate sull’atlante di un elefante fossile dei dintorni di roma. rivista italiana di paleontologia, 2, 326-332. portis a. (1899) una nuova specie di rinoceronti fossile d’italia? bollettino della società geologica italiana, 18, 116-131. portis a. (1900) di una formazione stagnale presso la basilica ostiense di roma e degli avanzi fossili vertebrati in essa rinvenuti. bollettino della società geologica italiana, 19, 179-240. portis a. (1902) di un dente anomalo di elefante fossile e della presenza dell’elephas primigenius in italia. bollettino della società geologica italiana, 21, 93-114. portis a. (1903) ancora delle specie elefantine fossili in italia. bollettino della società geologica italiana, 22, 143-146. portis a. (1904) un interessante fossile dei peperini. bollettino della società geologica italiana, 23, 171 -178. portis a. (1907a) è dimostrata la contemporaneità dell’uomo paleolitico coll’elefante antico, l’ippopotamo ed un rinoceronte in italia? bollettino della società geologica italiana, 26, 28-29. portis a. (1907b) di due notevoli avanzi di carnivori fossili dai terreni tufacei di roma. bollettino della società geologica italiana, 26, 63-87. portis a. (1907c) di alcuni avanzi fossili di grandi ruminanti principalmente della provincia di roma. palaeontographia italica, 13, 141-198. portis a. (1909) avanzi di canidi fossili. bollettino della società geologica italiana, 28, 203-244. portis a. (1920) elenco delle specie di cervicorni fossili in roma e attorno roma. bollettino della società geologica italiana, 39, 132-139. praturlon a. (1993) breve storia delle ricerche geologiche. in: cosentino d., parotto m., praturlon a. (eds.) lazio. 14 itinerari. guide geologiche regionali a cura della società geologica italiana, bema editrice, 5, 12-14. rellini u. (1916) aggiunte alla fauna pleistocenica italiana (comunicazione preventiva). atti della società dei naturalisti e matematici di modena, 3, 3034. roisecco g. (1750) descrizione di roma antica e moderna. roma, puccinelli. romano m. (2013) ‘the vain speculation disillusioned by the sense’: the italian painter agostino scilla (1629–1700) called ‘the discoloured’, and the correct interpretation of fossils as ‘lithified organisms’ that once lived in the sea. historical biology, 26(5), 631-651. romano m. (2014) from petrified snakes, through giant “foraminifers”, to extinct cephalopods: the early history of ammonite studies in the italian peninsula. historical biology, 27(2), 214 235. romano m. (2016) “per tremoto o per sostegno manco”: the geology of dante alighieri’s inferno. italian journal of geosciences, 135, 95-108. romano m. (2017) the theory of the earth of the bar 128 romano m. et al. nabite cleric ermenegildo pini: a mostly unknown italian catastrophist. historical biology, 29(4), 519538. romano m. (2018a) palaeoecology before ecology: the rise of actualism, palaeoenvironments studies and palaeoclimatology in the italian panorama between the fourteenth and eighteenth centuries. italian journal of geosciences, 137, 16-30. romano m. (2018b) italian diluvianism and antidiluvianism within the international arena: the great debate that lasted more than six centuries. proceedings of the geologists’ association, 129(1), 17-39. romano m. (2018c) “chi tutto il fenomeno non spiega, non ne spiega nulla”: anton lazzaro moro e la confutazione dei sistemi di burnet e woodward. rendiconti online della società geologica italiana, 45, 147-156 romano m., avanzini (2019) the skeletons of cyclops and lestrigons: misinterpretation of quaternary vertebrates as remains of the mythological giants. historical biology, 31(2), 117-139. romano m., palombo m.r. (2017) when legend, history and science rhyme: hannibal’s war elephants as an explanation to large vertebrate skeletons found in italy. historical biology, 29(8), 11061124. romano m., cifelli r., vai g. (2016) the first geological map: an italian legacy. italian journal of geosciences, 135, 261-267. rudwick m.j.s., (1972) the meaning of fossils: episodes in the history of paleontology. macdonald/ american elsevier, london/new york, 304. sardella r., bedetti c., iurino d. a., pavia m., bellucci l. (2015) comment on “reassessing the sedimentary deposits and vertebrate assemblages from ponte galeria area (rome, central italy): an archive for the middle pleistocene faunas of europe” by f. marra, l. pandolfi, c. petronio, g. di stefano, m. gaeta, l. salari [earth-science reviews 139 (2014), 104–122]. earth-science reviews, 147, 201-203. sardella r., mazzini i., giustini f., mecozzi b., brilli m., iurino d.a, lembo g., muttillo b., massussi m., sigari d., tucci s., voltaggio m. (2018) grotta romanelli (southern italy, apulia): legacies and issues in excavating a key site for the pleistocene of the mediterranean. rivista italiana di paleontologia e stratigrafia, 124(2), 247–264. sardella r., iurino d.a., mecozzi b., sigari d., bona f., bellucci l., coltorti m., conti j., lembo g., muttillo b., mazzini i. (2019) grotta romanelli (lecce, southern italy) between past and future: new studies and perspectives for an archaeo-geosite symbol of the palaeolithic in europe. geoheritage, 11(4), 1413-1432. segre a.g. (2001) palaeontology and prehistory in central italy: an historical summary. in: cavaretta g., gioia p., mussi m., palombo m.r. (eds.), the world of elephants, roma, 76-77. terrigi g. (1883) il colle quirinale, sua flora e fauna lacustre e terrestre, fauna microscopica marina degli strati inferiori. atti dell’accademia pontificia nazionale de’ nuovi lincei, 35, 1-32. tuccimei g. (1880) i colli pliocenici di maglianosabino. gli studi in italia, 3, 1-21. tuccimei g. (1883) sulla struttura dei terreni che formano la catena di fara in sabina. bollettino della società geologica italiana, 2, 16-39. tuccimei g. (1886) sopra le cavità naturali dei monti sabini. atti dell’accademia pontificia nazionale de’ nuovi lincei, 40, 43-45. tuccimei g. (1887) il sistema liassico di roccantica e i suoi fossili. bollettino della società geologica italiana, 6, 117-157. tuccimei g. (1888) bradisismi pliocenici della regione sabina. memorie dell’accademia pontificia nazionale de’ nuovi lincei, 4, 107-121. tuccimei g. (1889) il villafranchiano nelle valli sabine e i suoi fossili caratteristici. bollettino della società geologica italiana, 8, 13-58. tuccimei g. (1890a) note stratigrafiche sopra la formazione secondaria dei monti sabini. memorie dell’accademia pontificia nazionale de’ nuovi lincei, 6, 266-277. tuccimei g. (1890b) rinvenimento di avanzi di elephas meridionalis nesti, nel pliocene di montoro. atti dell’accademia pontifica nazionale de’ nuovi lincei, 43, 27-28. tuccimei g. (1891) alcuni mammiferi fossili delle provincie umbra e romana. memorie dell’accademia pontificia nazionale de’ nuovi lincei, 7, 89-152. tuccimei g. (1893) resti di arvicola nel pliocene lacustre della sabina. memorie dell’accademia pontificia nazionale de’ nuovi lincei, 9, 36-45. tuccimei g. (1895) il villafranchiano e l’astiano nella valle tra i corniculani e i lucani. memorie dell’accademia pontificia nazionale de’ nuovi lincei, 11, 41-66. tuccimei g. (1898) sopra alcuni cervi pliocenici della sabina e della provincia di roma. memorie dell’accademia pontificia nazionale de’ nuovi lincei, 14, 33-35. tuccimei g. (1899) sopra alcune ossa fossili di cervo trovate sulla via aurelia. atti dell’accademia pontificia nazionale de’ nuovi lincei, 52, 65-67. vai g.b. (2003) a liberal diluvianism. in: vai g.b., cavazza w. (eds.), four centuries of the word geology: ulisse aldrovandi 1603 in bologna. bologna, minerva edizioni. bologna, minerva edizioni, 221-249. verneuil p.e.p. de (1865) sur le diluvium des environs de rome. bulletin de la société géologique de france, 22, 519-522. ms. received: january 20, 2020 revised: march 10, 2021 accepted: march 16, 2021 avaiable online: march 26, 2021 the quaternary paleontological research in the campagna romana (central italy) at the 19th-20th century transition: historical overview 129 130 microsoft word 02_martinetto_lm05.doc available online http:/amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 25 (2), 2012, 91-104 an early pleistocene plant assemblage with east european affinity in the venetian-friulian basin (ne italy) edoardo martinetto1, giovanni monegato2 & elena vassio1 1 dipartimento di scienze della terra, università degli studi di torino, torino (italy) 2 istituto di geoscienze e georisorse, consiglio nazionale delle ricerche, torino (italy) corresponding author: g. monegato <g.monegato@csg.to.cnr.it> abstract: a palaeobotanical study, including pollen and carpological analyses, has been carried out on the brown coal seam of san pietro di ragogna (friulian foothills). the palynoflora and carpoflora have been analysed with the plant community scenario approach for a better interpretation of their palaeovegetational signals. the coal-bearing layer, despite its limited chronological extension and exposure, is significant for the occurrence of several fossil fruits and seeds belonging to taxa with east european affinity, recorded for the first time in italy, such as hypericum tertiaerum, myriophyllum praespicatum, najas major-pliocenica, nymphaea borysthenica, potamogeton cf. panormitanoides, schoenoplectus cf. lacustroides. their concomitant occurrence with carex cf. elata, menyanthes trifoliata and nuphar aff. lutea, which appear in italian floras after the piacenzian/gelasian boundary, points to a gelasian age of the studied coal deposit. such hypothesis is also supported by the floristic/vegetational affinities with selected gelasian floras from central and eastern europe. the coal deposit directly overlays the regional unconformity, ascribed to the messinian, which marks the base of the quaternary succession in the friulian piedmont plain. the geographical location of the site is also significant for the reconstruction of palaeovegetational changes at the plio-pleistocene transition. in fact, the occurrence of east european elements may indicate that the migration of plant taxa from eastern europe reached the easternmost part of northern italy, under the effects of climate worsening related to the inception of glacial periods in the northern hemisphere. keywords: carpology, pollen, palaeovegetation, early pleistocene, pcs approach, se alps. 1. introduction the knowledge of the early pleistocene vegetation in the alpine fringe of northern italy is established thanks to palynological studies on some remarkable continental successions in the central southalpine foothills (ravazzi & rossignol-strick, 1995; ravazzi et al., 2005; muttoni et al., 2007; ravazzi et al., 2009), as well on the marine succession of the venice core, in the eastern portion, at the adriatic shoreline (massari et al., 2004). on the southern side of the po plain, in the outer fringe of the northern apennine, several palynological studies on marine successions cover the pliocene and pleistocene interval (e.g., lona & bertoldi, 1973; rio et al., 1997; bertini, 2001; fusco, 2007). the pollen records of these successions are very rich, but are accompanied by a scarce macrofloral record (gregor, 1990; ravazzi & rossignol-strick, 1995; ravazzi et al., 2005), which hampers the thorough documentation of the palaeofloral development during the early pleistocene. in this sense only the rich palaeocarpological record (ghiotto, 1995; 2010) of the steggio site (sala & tonon, 1992; paronuzzi & tonon, 1992), in the venetian foothills, partially fills the macropalaeobotanical gap, but without providing pollen data. also the geographical gap is partly filled, as the steggio site is located (fig. 1) between the italian peninsular record (e.g., gregor, 1990; girotti et al., 2003; magri et al., 2010) and the scattered record of central and eastern european localities (fig. 1), summarized by velichkevich & zastawniak (2003). the venetian-friulian plain was physically disconnected from the po plain till the second half of the middle pleistocene, when the progradation of the alluvial systems and the merging of the alluvial plains led to the filling of the northern adriatic gulf (massari et al., 2004; muttoni et al., 2010; garzanti et al., 2011). moreover, the venetian-friulian plain was connected to the danube basin through low relieves, in between the elevated barriers of the eastern alps and the dinarides. due to such palaeogeographic context, in the early-middle pleistocene north-eastern italy was a corridor between eastern europe and the italian peninsula (muttoni et al., 2010). despite this key-location, north-eastern italy still has a relevant lack of palaeofloral information, so that every new palaeobotanical site represents an important improvement for the knowledge of the early pleistocene phytogeographic development in this area. the present paper is aimed to investigate the palaeofloral characteristics of the first early pleistocene site in the friulian foothills (san pietro di ragogna), in comparison to the palaeoenvironmental record of the southalpine area and other palaeobotanical records from the rest of italy and eastern europe. 2. geological setting the ragogna hill represents the southernmost relief of the carnian prealps (fig. 2) and is located in the correspondence of the frontal thrust of the eastern southalpine chain (esc), the arba-ragogna thrust (galadini et al., 2005; poli et al., 2009). the southern slope martinetto e. et al. 92 of the ragogna hill is characterised by deep incisions related to small tributaries of the tagliamento river that followed the deepening of the fluvial network during the last deglaciation (monegato et al., 2007). in the slope of the tagliamento left bank, as well as within the incisions of the ragogna hill, a succession of coarse continental deposits crops out, which has been the subject of studies since the end of 19th century. the early work by tellini (1892) provides a first detailed description of the succession; he remarked a petrographic distinction between a lower (“pontian”) conglomerate, ascribed to a transitional-marine environment, and an upper continental conglomerate. the mollusc assemblage in the brown coal layer located at the base of the upper conglomerate unit was characterised by continental taxa such as helix, limnea, planorbis, valvata, bithynia, unio and pisidium (tellini, 1892). whereas, no palaeobotanical analysis was carried out on the brown coal layer. the subsequent works (stefanini, 1915; feruglio, 1925, 1929) maintained tellini’s assumption considering the upper conglomerate as “villafranchian”, not because of the discovery of mammal assemblages, but for hypothetical age-relationships with the type-succession of villafranca d’asti, rich in mammal remains (carraro, 1996). only recently, the surveys for the new geological map of italy yielded an improvement to the knowledge of the stratigraphy of the friulian foothills. these studies enlightened the tectonic structures of the front of the esc (galadini et al., 2005) and the presence of several angular unconformities characterising the stratigraphy of the succession (paiero & monegato, 2003; zanferrari et al., 2008) related to the activity of the arba-ragogna thrust since the end of the miocene (poli et al., 2009). the lower conglomerate (“pontian” sensu tellini, 1892) was mapped as montello conglomerate and revised as a messinian continental deposit (zanferrari et al., 2008). the upper conglomerate (“villafranchian” sensu stefanini, 1915) was mapped as san pietro di ragogna conglomerate (zanferrari et al., 2008). both conglomerate units are well exposed in the southern slope of the ragogna hill along the ponte and mordaro creeks (fig. 2). the succession has at the bottom the thick upper member of the montello conglomerate, which is about 600 m thick and tilted of 60° to 90° fig. 1 map of the main european localities with fruit and seed assemblages assigned to the pliocene and gelasian; also a few calabrian localities of italy are reported (herieinafter “calab.”). localities of pliocene floras in europe. 1 kholmech, 2 dvorets, 3 kolochin, 4 stradubka, 5 simbugino, 6 šlavė, 7 daumantai, 8 cherovitskoye, 9 krivoborye, 10 ivnitsa, 11 dan’shino, 12 uryv, 13 moiseyevo, 14 shekhman’, 15 ranino, 16 manovitsy, 17 malaya began’, 18 mizerna, 19 krościenko, 20 grywałd, 21 ruszów, 22 kłodzko, 23 vildštejn formation, 24 rippersroda, 25 nordhausen, 26 reuver, 27 brunssum, 28 swalmen, 29 tegelen. bu, buronzo, cervo river section; lf, leffe (calab.); pf, pietrafitta (calab.); sg, steggio (calab.?); spr, san pietro di ragogna; tp, torre picchio. modified after velichkevich & zastawniak (2003). an early pleistocene plant assemblage with east european affinity … 93 towards the south-east (fig. 3). the pebbles of this conglomerate are exclusively made of upper triassic cretaceous carbonate rocks, with minor cherts and eocene turbidites (venturini & tunis, 1992); sandstone layers and lenses are rare, while finer sediments are lacking. the messinian age is constrained by radiometric datings at the marine/continental transition (grandesso et al., 2000). no peat layers were recognised within this unit. an angular unconformity marks the boundary of the montello conglomerate with the san pietro di ragogna conglomerate (spc). this is an erosion surface in which the difference in dip varies from 25° to 45° (fig. 3), depending on where the erosional surface cuts the previously deformed messinian unit. in correspondence of the boundary, the basal portion of the succession is made of a few-meters-thick consolidated silty clay with a brown coal seam. this coal, shows a millimetric lamination and lacks any sign of bioturbation; it contained well-recognizable plant remains, such as extremely compressed wood fragments, up to 10 cm in cross-section, and small fruits and seeds, mostly variously compressed and deformed, except for those included in clay-rich brown coal. actually, this layer crops out in hardly-accessible spots because it had been intensively mined as fossil fuel during the late 19th century (feruglio, 1925), but abundant samples of this brown coal seam are available in dump deposits. above these basal deposits, about five meters of coarse laminated sandstones occur and the upper transition to conglomerates is gradual. conglomerates show crude to planar bedding; clasts are sub-rounded to rounded and maximum size span from 10 to 30 cm, with a coarse layer in which some clasts reach 50 cm in diameter (fig. 4). clast petrography is dominated by carbonates (dolostones and limestones), however it can be clearly distinguished from those of the montello conglomerate for the relative abundance in palaeozoic and lower triassic sandstones, low-grade metamorphic phyllites and acidic volcanic fragments, pointing to a provenance from the postmessinian tagliamento catchment (monegato & stefani, 2010; monegato & vezzoli, 2011). the spc has a preserved thickness of about 110 m and is bounded at the top by an erosion surface, over which a younger unit, of middle pleistocene age (paiero & monegato, 2003), lies with an angular unconformity (u2) of about 15° (fig. 3). 3. material and methods a pollen sample was collected in the brown coal seam, and treated following standard chemical methods (including acetolysis) in use at the laboratory of palynology and paleoecology of consiglio nazionale delle ricerche istituto per la difesa e protezione ambientale (cnr-idpa) of milan. pollen and charcoal concentrations have been calculated with the addition of lycopodium tablets following procedures outlined by stockmarr (1971); fucsina-red was added for a better distinction of palynomorphs. the identification of pollen grains and spores was based on the atlas and identification keys of european pollen floras (moore et al., 1991; reille, 1992-1995; punt & blackmore, 1976-2004; beug, 2004) and on the reference collection of the cnr-idpa. pollen nomenclature follows the alpadaba (alpine palynological database) list of pollen types housed at the institute of plant sciences, university of bern. plant macrofossils have been obtained by preparation of two bulk sediment samples (spr1b9a, 3 dm3 and spr1cof, 4 dm3). however, it has been very difficult to disaggregate the sediment, since the standard procedure (basilici et al., 1997) did not work very well with the extremely compact and carbonate-rich brown coal of spr. several cycles of drying, treatment with 5% h2o2 and freezing were necessary to obtain the fluidification of only 2/3 of the sediment volume, so 1/3 could not be analysed. after the last immersion in 5% h2o2, the floating fraction, rich in fruits and seeds, has been filtered with a mesh size of 0.3 mm. the plant remains within the fluidified sediment, deposited at the bottom of the bucket, have been collected with a mesh size of 0.8 mm and washed with a powerful water jet. fig. 2 aerial photo of volo gai (1951) of the ragogna hill with the sample location marked with the red star. green area: montello conglomerate (messinian); orange area san pietro di ragogna conglomerate. a-a’: trace of the profile of fig. 3. fig. 3 geological section of the ragogna hill: 1. montello conglomerate (messinian); 2. san pietro di ragogna conglomerate; 2a. coal seam location; 3. middleupper pleistocene units; u1: angular unconformity of about 25°; u2: angular unconformity of about 15°. martinetto e. et al. 94 the residues obtained after washing have been slowly dried and observed under a stereomicroscope in order to pick up fruits and seeds and to identify them on the basis of their characteristic morphological traits. for identification, we combined the information provided by specialised literature (mainly: geissert et al., 1990; mai & walther, 1988; nikitin, 2006; reid & reid, 1915; velichkevich & zastawniak, 2003, 2006, 2009) with the direct observation of fresh fruit and seed material of the modern carpological collection (mcc) stored at the department of earth sciences of the torino university. finally, these identifications were compiled into floristic lists, and abundance data were generated based on counts of the fruit and seed taxa identified. for the interpretation of palaeovegetation, the microand macropalaeobotanical quantitative and qualitative data have been analysed and graphically synthesized by means of the plant community scenario (pcs) approach (martinetto & vassio, 2010): both data sets are fundamental for palaeoenvironmental and palaeobiogeographic interpretations (birks & birks, 2000), because they usually provide complementary and integrating information (bůžek et al., 1985; bertini & martinetto, 2011). among the several aims of the pcs approach, in the present paper we focused on the homogenous rendering and subsequent comparison of the information provided by different fossil plant records, in order to propose a more reliable reconstruction of the palaeovegetation. at the state of the art, and despite the attempt in this sense (martinetto & vassio, 2010; vassio, 2012), there is still no precise method to correct the well-known bias between qualitative composition of carpological assemblages and their potential source plant communities. therefore it is not possible to transform the pcs diagram into a quantitative reconstruction of palaeovegetation. however, the pcss obtained from ancient deposits can be successfully compared to the ones obtained from modern sedimentary contexts (vassio, 2012), where the vegetation has been directly surveyed. the relationship pcs of modern vegetationpcs of modern sediment-borne carpological assemblages is the key for the interpretation of the unknown palaeovegetational context which is implicit into a pcs diagram obtained from a fossil assemblage. 4. results 4.1 palaeofloral analysis the pollen analysis on the brown coal yielded an assemblage dominated by conifers (tab. 1 and fig. 4): pinus, which exceeds 50 %, and picea (2.3%). the remaining arboreal plants are taxodioideae and broadleaved trees, such as quercus, ulmus, carya, tilia and betula. trees represent 87% of pollen; non-arboreal taxa are dominated by poaceae (8%). the abundance of herbaceous aquatic and wetland taxa (such taxa were not included in the total pollen sum in tab. 1) indicates a wet environment (i.e., a mire) close to the sedimentation site. the carpological analysis of two samples (spr1b9a, spr1c0f) permitted the identification of 33 taxa (tab. 2), most of them at species level, thus allowing to obtain fig. 4 log of the rio ponte section of the san pietro di ragogna conglomerate; u1 and u2 are the angular unconformities of fig. 3. arrow indicates the sampled layer for which a synthetic pollen spectrum is reported. aquatic and wetland herbs (tab. 1) have been excluded from the pollen sum. an early pleistocene plant assemblage with east european affinity … 95 a quite detailed description of the vegetational composition, at least of a limited area close to the depositional site (as reported in chapter 4.3). because the pollen assemblage does not show distinctive taxa for a trustworthy biostratigraphy, the systematic discussion is provided only for fruit and seed taxa, which yield new interesting scenarios for the italian palaeovegetation. 4.2 relevant fruit and seed taxa systematic part the systematics of families follows farjon (1998), gadek et al. (2000) and apg iii (2009). family cyperaceae genus carex l. carex cf. elata all. plate i-2-9 the interesting 2-sided carex achenes from spr have been examined in the frame of an ongoing comprehensive work, focussed on sect. phacocystis in europe (jimenez-mejias, 2011). several 2-sided achenes could be assigned to sect. phacocystis, because of the diagnostic persistence of utricle remains attached at the achene’s base (plate i-8), the non-jointed style (unfortunately always incomplete) and the frequent occurrence of a thin basal callus (plate i-9). the extensive examination of modern material of all the european species permitted to restrict the field of affinity to a single species: carex elata all. (plate i-1). however, the determination is left in open nomenclature because it is not yet clear if, before the pleistocene, the modern carex elata all. did already exist. in fact such species has proved to be of recent hybridogenous origin, and its ancestors are still not well known (jimenez-mejias, 2011). so, it is still to be better investigated if fruits of this type, in the gelasian-calabrian fossil record, testify for the occurrence of c. elata or an unknown ancestor. distribution: the european fossil record of c. elata has to be revised on the basis of the new assessment of diagnostic fruit characters (jimenez-mejias, 2011). however, the revision of the abundant italian material of the cenofita collection (martinetto & vassio, 2010) suggests that c. elata or carex cf. elata are not documented in the piacenzian or earlier. the first occurrence of fruits of carex cf. elata, with abundant and well preserved material, is recorded in a succession which is tentatively assigned to the gelasian (castelletto cervo ii-buronzo: martinetto, 2001; zanni & ravazzi, 2007). fossil fruits of c. elata are also reliably documented within middle pleistocene interglacials (mai, 2010). eleocharis microstylosa mai plate i-10-13 the very small, slender fruits with small tubercle and longitudinally elongated cells correspond in shape, dimensions and structure of the tubercle to the specimens of e. microstylosa mai described by mai & walther (1988). the very similar fruits of e. praemaximoviczii dorofeev are distinguished by larger mean dimensions, broader fruits, and more apparent tubercle (velichkevich & zastawniak, 2003). among the species living today in tab. 1 pollen analysis of the san pietro di ragogna brown coa. tab. 2 abundance of the fruit and seed taxa indentified in the two sediment samples from san pietro di ragogna. martinetto e. et al. 96 plate i stereomicroscope micrographs of selected fossil fruits and seeds from san pietro di ragogna (continuous magnification bar = 1 mm; dashed bar = 0.5 mm): 1 carex cf. elata all.; modern achene from san carlo canavese, for comparison with the fossil specimens; 2-9 carex cf. elata all.; 2 undeformed achene with apparent longitudinal rows of small cells and distinct remains of utricle tissues at the base (arrow); 3-8 achenes, variously deformed by diagenetic compression; 7 achene diagenetically shortened against the long axis; 8, 9 laterally compressed achene with small, but distinct, callus (arrow); 10-13 eleocharis microstylosa mai; 10 achene with a distinct longitudinal ridge, clue to a 3-sided section; 11 achene with rows of longitudinally elongated cells; 12 the largest recovered achene; 13 small achene with clear tubercle; 14 myriophyllum praespicatum p. nikitin, endocarp in dorsal and ventral view; 15, 16 hypericum tertiaerum p. nikitin; 15, seed showing the raised raphe running from base to apex; 16, seed with apparent rows of transversally elongated, and slightly oblique, cells; 17 potamogeton cf. panormitanoides dorofeev, endocarp from both sides; 18, 19 potamogeton natans l., fruits in lateral view, with apparent remains of the lustrous exocarp covering the endocarp. an early pleistocene plant assemblage with east european affinity … 97 italy (ercole et al, in press), they are partly similar to those of e. carniolica and even more to e. pellucida (verloove, 2010), an east asian species recently introduced in italy, from which the fossils can be distinguished for the narrower fruit and the smaller tubercle. one of the fossils has a 3-sided section, as frequently occurring in e. pellucida (never in e. carniolica). distribution: mai & walther (1988) reported this species from the localities kroscienko (zanclean, poland) and öbel (piacenzian, nw germany), mizerna ii/iii (gelasian, poland) and tegelen (gelasian, the netherlands); first occurrence in italy. family haloragaceae myriophyllum praespicatum p. nikitin plate i-14 the fruits are rather similar to those of the modern m. spicatum, but they are particularly short and broad, and have several large tubercles on the dorsal face, a feature that is indicated by velichkevich & zastawniak (2003) as characteristic of the type specimens of m. praespicatum from the locality krivobor’e, together with the chalaza situated above the base. endocarps of modern m. spicatum are always more slender and have fewer and less distinct tubercles. m. praespicatum also has definitely more distinct surface cells. the endocarps of another morphospecies, m. pseudospicatum dorofeev are smaller, with smaller and blunt tubercles (velichkevich & zastawniak, 2003). distribution: mai & walther (1988) reported this species from the miocene of western siberia and the neogene of europe, where possibly the youngest occurrence is the gelasian of kholmech (velichkevich & zastawniak, 2007). first occurrence in italy. family hypericaceae hypericum tertiaerum p. nikitin plate i-15, 16; fig. 5a the several seeds of hypericum recovered at spr show a relatively high variability (fig. 5a,b), but most of them (fig. 5a) agree in all characters with those of h. tertiaerum, described with good detail by velichkevich & zastawniak (2003), who stated they their specimens correspond to those of the type locality krivobor’e as for dimensions (0.7-1.0 x 0.45-0.6 mm), shape and testa sculpture. nikitin (2006) clearly showed the differences between h. tertiaerum p. nikitin and h. septestum p. nikitin ex v. p. nikitin. plate ii stereomicroscope micrographs of selected fossil fruits and seeds from san pietro di ragogna (magnification bar = 1 mm): 1-3 nymphaea borysthenica dorofeev; compressed seeds with variable sculpture; 4-6 nuphar aff. lutea (l.) sibth. et sm.; 4 longitudinally compressed seeds; 5 laterally compressed seed, probably preserving the original longitudinal outline; 6 another laterally compressed seed showing the typical finely foveolate ornamentation; 7, 8 acer sect. platanoidea: 7 endocarp in lateral view; 12 fruit with wing remains to the right and the left half removed to show the seed inside; 9 tilia tuberculata szafer, compressed and incomplete fruit showing the typical tuberculate sculpture. martinetto e. et al. 98 distribution: velichkevich & zastawniak (2003) reported miocene records from germany to siberia, and more frequent pliocene ones from central russia to germany. our overview of the cenofita collection (martinetto & vassio, 2010) permitted to summarize the occurrences in italy: typical seeds of h. tertiaerum occur rarely in zanclean assemblages, and frequently in piacenzian ones; they still occur also in the uppermost part of the cervo river section in piedmont, interpreted as gelasian (martinetto, 2001). as for the occurrences in the calabrian, there is no unequivocal record, a similar form of hypericum seeds was only found by r. pini & r. ravazzi in a locality of the leffe basin (ravazzi & rossignol-strick, 1995); this material should be better investigated because its characters also agree with those of the younger species h. pleistocenicum, whose seed coat is as thick as that of h. tertiaerum, but with distinctly narrower cells (velichkevich & zastawniak, 2009). definitely different hypericum forms occur in the neighbouring lower pleistocene site of steggio (ghiotto, 2010) and in the middle pleistocene sites (vassio, 2012). family malvaceae tilia tuberculata szaferplate ii-9 a single, fragmentary and much compressed fruit is assigned to this species on the ground of the typical ornamentation, compared to that of specimens from the relatively neighbouring locality of steggio (ghiotto, 2010). other characters which are still visible are 3 of the 5 original ridges (the others cancelled by compression), the attenuate apical part and the unevenness of the internal structure, also including a spongy tissue as typical for fossil fruits of tilia. distribution: mai & walther (1988) and ghiotto (2010) reported this species from the “upper” pliocene of germany and russia, and in the lower pleistocene localities schweinheim (germany) and steggio (italy: here interpreted as calabrian, less probably gelasian: ciangherotti et al., 2007). family nymphaeaceae nuphar aff. lutea (l.) sibthorp et smith plate ii-4-6; fig. 6 the very abundant seeds of nuphar found in both samples agree very well in shape, dimensions, operculum structure (fig. 6a) and ornamentation (finely foveolate: fig. 6b) with those of the living nuphar lutea (l.) sibth. et sm. however, the comparison with fossil seeds from middle-late pleistocene localities (bucine, valeriano creek: vassio, 2012), reliably referable to n. lutea, showed that they have the same shape and operculum structure, but differ for the larger cells, thus raising doubts on the precise specific identification. in addition, dorofeev (1974) described, on the basis of fossil seeds from russia and siberia, several species (e.g., n. tanaitica dorofeev) particularly difficult to differentiate from n. lutea. our revision of the cenofita collection (martinetto & vassio, 2010) permitted to conclude that a distinct species, with more rounded shape, different operculum, and smaller cells with thicker walls (n. canaliculata c et e.m. reid) occurs in several pliocene localities of italy. distribution: mai & walther (1988) and velichkevich & zastawniak (2003) reported an upper miocene record of n. lutea from poland. this same species is also reported for the mio-pliocene of alsace (geissert et al., 1990), and more frequently in pliocene floras from central russia to germany. in italy n. canaliculata occurs widely in the zanclean and piacenzian, whereas nuphar aff. lutea seem to appear at first at spr, and the fossil record is still too fragmentary to assess the relationship between this form and the typical n. lutea found in middle-late pleistocene localities. a further detailed fig. 5 population of fossil seeds of hypericum from san pietro di ragogna; a) specimens with the characters typical for hypericum tertiaerum p. nikitin; b) two narrower seeds (magnification bar = 1 mm). fig. 6 nuphar aff. lutea (l.) sibth. et sm., fossil seeds from san pietro di ragogna; a) detail of the operculum of a seed; b) detail of the cell structure of another seed (magnification bar = 1 mm). an early pleistocene plant assemblage with east european affinity … 99 investigation of nuphar fossil seeds is desirable, and comparison with analogous material throughout europe may yield interesting biochronological results. nymphaea borysthenica dorofeev plate ii-1-3; fig. 7 the dimensions, consistence, sculpture (fig. 7) and cell shape of the spr material completely agree with those of seeds of n. borysthenica from the type locality kholmech (velichkevich & zastawniak, 2003). the hardly distinguishable n. pilosella is described by nikitin (2006). the seeds of all modern eurasian species differ for the shape of the testa cells. distribution: n. borysthenica has been known hitherto from the gelasian (velichkevich & zastawniak, 2007) locality of kholmech and from central russia (velichkevich & zastawniak, 2003). this is the first occurrence in italy. 4.3 vegetation analysis the most frequent diaspores represent typical aquatic plants of standing or slowly flowing water (najas major-pliocenica, nuphar aff. lutea), but some wetland plants (helophytes, such as carex and menyanthes) are also not rare. as a whole, these freshwater macrophytes permit to accurately characterise the ancient autochthonous vegetation of the basin, where deposition took place. the mesic plants are represented by a few taxa which produce windor animaltransported fruits (acer spp., carpinus betulus, pinus peuce, tilia tuberculata, vitis sp.). these provide a very partial picture of the ancient mesic vegetation once growing around the depositional basin, that can be improved by the comparison with the palynological record. two different 2d plant community scenarios (pcss) for pollen and macrofossils have been built up by subdividing the environmental transect in three zones according to the ecological characteristics of the taxa. the frequency data of every taxon have been proportionally reported into the pcss, according to the approach introduced by martinetto & vassio (2010), as to represent 50 plant symbols and 25 taxa names. the two pcss put forth the different qualitative and quantitative (and complementary) information provided by the two records: a pinus-dominated mesic sector and a cyperaceae/taxodioideae-dominated hygrophilous sector for the pollen-pcs (fig. 8a), and a freshwater macrophytedominated aquatic sector in the carpological-pcs (fig. 8b). the huge percentage of conifers (pinus and picea) within the pollen record is not surprising, as well as betula and artemisia occurrence. usually they represent taxa growing at a certain distance (and possibly at higher altitude, in similar contexts) from the deposition site, which may reach significant percentages in the southalpine area, even in warm-temperate phases (e.g., pini et al., 2010). tilia and alnus are detected within both records, but in very low percentages, hence a limited presence can be hypothesized, as well as for carpinus and acer (absent in the pollen assemblage). quercus and corylus pollen grains, allow to increase the knowledge about mesic woody taxa occurring in the san pietro di ragogna palaeoflora (in addition to few grains of ulmus, fraxinus, carya and juglandaceae); the lack of their diaspore may be explained either by their large size, decay-prone structure or the sedimentary context. an interesting difference, deals with the taxodioideae, detected within the palynological association but completely absent in the carpological assemblage: this can not be explained only by the characteristics of their seeds (small, wind-dispersed and decayresistant). therefore, taxodioideae should have grown outside the deposition area. 5. discussion 5.1 vegetation reconstruction the palaeobotanical record of san pietro di ragogna can be interpreted from the dissimilar results of the pcs structure for pollen and macrofossils, which are conditioned by well-known taphonomical biases; macroremains usually reflect local plant communities better than other records, also from a quantitative point of view (watts & winter, 1966; burrows, 1980; collinson, 1983; thomasson, 1991; sims & cassara, 2009; vassio, 2012). pollen assemblages provide a better record of the regional vegetation, yet with relevant biases. in the spr sample, the high pollen percentage of pinus, reflected by the dominance of this plant in the pcs, is probably affected by overrepresentation, due to high pollen production and/or lakeshore concentration. however, excluding other taphonomical factors such as distal sedimentation, the abundance of pinus pollen may also be ascribed to the widespread occurrence of this plant in the carbonate prealpine relief of the surrounding area. for sound interpretation of the mesic palaeovegetation, we therefore take into account the presence of several broad-leaved trees (e.g., betula, carya, quercus, tilia, ulmus), which should be considered more relevant in the palaeovegetation than indicated by the relatively low pollen percentages. the pcs structure for the carpoflora shows a poor contribution from this mesic vegetation to the fruit and seed assemblage (e.g., acer, carpinus, pinus, tilia), as frefig. 7 nymphaea borysthenica dorofeev fossil seed from san pietro di ragogna, with apparent rows of transversally elongated cells (magnification bar = 1 mm). martinetto e. et al. 100 quently occurring in lacustrine environments (birks, 1973; collinson, 1983; dieffenbacher-krall & halteman, 2000). the wetland vegetation is more consistently represented in both pcss, but even in this case the macrofossil record lacks the important taxodioideae contribution, which could even be interpreted as a pollen influx coming from outside the sedimentary basin, possibly from a nearby coastal environment. on the other hand, the herbaceous component shows a consistent agreement between the two pcss suggesting a rather extended sedge belt, possibly hosting relevant patches of menyanthes, based on the frequency of seeds. the predominance of freshwater macrophytes requiring more than 1 meter of water depth (nuphar, nymphaea, najas) would suggest an open standing-water environment. furthermore, actuopalaeobotanical studies on modern lakes (dieffenbacher-krall & halteman, 2000) detected seed assemblages with concomitant high frequencies of carex and najas diaspores in 0.5-1.5 m deep bottoms. 5.2 biochronological and biogeographical signals the san pietro di ragogna brown coal represents a spot on the knowledge of the vegetation in the southeastern alps, before the expansion of the tagliamento glacier piedmont lobe during the middle pleistocene cold phases (monegato et al., 2010). the chronological attribution of the coal deposit was not precisely assessed from a stratigraphical point of view, because of its position at the base of a coarse-grained unit, the san pietro di ragogna conglomerate (zanferrari et al., 2008), which is bounded by angular unconformities between the messinian montello conglomerate (zanferrari et al., 2008) and the middle pleistocene alluvial units of the arzino alluvial fan (paiero & monegato, 2003). so, the dating of the spr brown coal could encompass the pliocene-middle pleistocene time span. the pollen assemblage (tab. 1) reduces the possible chronological attribution, excluding a pliocene age because of the lack of some thermophilous taxa, usually associated to the taxodioideae (such as engelhardia, itea, myrica, nyssa, symplocos, etc.), that experienced fig. 8 plant community scenario diagrams provided by a) pollen and b) carpological records from san pietro di ragogna. notice that the pcss do not represent actual reconstructions of the paleoenvironment and palaeovegetation, rather they are simply a graphical representation of quantitative data. each typology of plant symbol is referred to a group of taxa that shares habitus and ecological features (martinetto & vassio, 2010; vassio, 2012). fifty plant symbols (and 25 taxa names, among the most frequent) have been reported into the diagram by taking into account their ecological requirement; their proportions reflect the frequencies of taxa belonging to these groups (growth forms) within the fossil assemblages. an early pleistocene plant assemblage with east european affinity … 101 a significant reduction at the end of pliocene (bertini, 2010). nevertheless, the spr assemblage contains a high percentage of taxodioideae, which are described in northern italy till the early calabrian (bertini, 2010 and references therein), whereas the rest of the taxa of the spr record are present in the middle pleistocene (carya) or in the late pleistocene. the models of early pleistocene climatic/vegetation cycles in italy (e.g., combourieu-nebout, 1993; bertini, 2001; leroy, 2007) suggest that the spr spectrum (fig. 4) could be included within an interglacial period, possibly within a “deciduous forest” phase (bertini, 2001), even if a single spectrum may be unreliable for a firm attribution. the macrofossil assemblage of spr documents a set of freshwater macrophyte genera with relevant similarity to the ones of modern north italian lakes. also the living species menyanthes trifoliata and potamogeton natans are firmly documented by the carpological record. nevertheless, the detailed morphological analysis of fossils fruits and seeds of the spr site allows to recognize precise morphospecies (eleocharis microstylosa, hypericum tertiaerum, myriophyllum praespicatum, najas major-pliocenica, nymphaea borysthenica), reported only in pliocene and early pleistocene localities of eastern europe (velichkevich & zastawniak, 2003, 2006). in the italian context, the spr palaeoflora shows a characteristic association between taxa of miocene origin (hypericum tertiaerum, myriophyllum praespicatum) and “younger” ones (carex cf. elata, menyanthes trifoliata, nuphar aff. lutea), which appear in the italian floras after the piacenzian/gelasian boundary. this characteristic association would restrict the chronostratigraphical bracket of the spr site to the gelasian. a hypothetical piacenzian age is much unlikely due to the occurrence of carex cf. elata (see above); conversely, the rejection of a possible calabrian age relies on the gelasian extinction of eleocharis microstylosa, hypericum tertiaerum, myriophyllum praespicatum and nymphaea borysthenica, which should actually be better documented. in fact it has been proved that, in the pliocene, several species disappear later in italy than in central europe (martinetto, 2001). partial support to the gelasian age is provided by the recovery of a very similar palaeofloral association in the “trapa layer” flora of buronzo, also interpreted as gelasian (martinetto, 2001). in the calabrian comparable assemblages of freshwater macrophytes have been found in the pietrafitta site (fusco, 2007; martinetto, unpublished data), but despite of the occurrence of the same genera, the species are distinct. in the late pleistocene neighbouring site of valeriano creek (monegato et al., 2010; vassio, 2012) the genera nuphar and nymphaea are already represented by the species which grow nowadays in this area, respectively n. lutea and n. alba. the presence in the spr assemblage of hypericum tertiaerum, myriophyllum praespicatum, najas major-pliocenica, nymphaea borysthenica, potamogeton cf. panormitanoides, schoenoplectus cf. lacustroides points to a singular east-european affinity. for this reason, the spr assemblage, even if relatively speciespoor, assumes a peculiar character in the framework of the several carpological assemblages known in northern and central italy (martinetto, 1999; martinetto & vassio, 2010). the geographic position of the site in the venetian-friulian plain played an important role, because it was confined in the northeastern margin of the adriatic gulf, isolated from the po plain (massari et al., 2004; muttoni et al., 2010), but close to the low elevated relieves at the alps-dinarides junction. due to such a location the site was under the major influence of the palaeofloral changes occurred during the plio-pleistocene transition, when the migration of plant taxa from eastern europe may have reached only the easternmost part of northern italy. 6. conclusion the san pietro di ragogna record, in spite of its limited chronological extension and its position far from other sites with carpological documentation, represents an important site for the occurrence of a peculiar palaeobotanical assemblage, characterised mainly by hypericum tertierum, myriophyllum praespicatum, najas major-pliocenica, nymphaea borysthenica, potamogeton cf. panormitanoides, schoenoplectus cf. lacustroides, which points out definite affinities with the gelasian flora of kholmech (belarus). most of these species have been recorded for the first time in italy, despite the rich macropalaeobotanical documentation available. on the basis of the known chronological distribution of the foregoing taxa, and the occurrence of “younger” ones (carex cf. elata, menyanthes trifoliata, nuphar aff. lutea), which appear in the italian floras after the piacenzian/gelasian boundary, we recognise a characteristic association that points to a gelasian age, possibly during a deciduous forest phase. the concomitant high frequency of diaspores of carex and najas suggests that the deposition of the san pietro di ragogna brown coal took place on a lacustrine bottom at a dept ranging from 0.5 to 1.5 meters, as suggested by studies on modern lake bottoms. this ancient lake was occupied by a diverse community of freshwater macrophytes, passing to a distinct sedge belt in the marginal area. due to the lack of macrofossils of taxodioideae, that are abundant in the pollen record, we conclude that these plants should have grown outside the basin, possibly in the neighbouring coastal area. finally, the mesic vegetation in the surrounding plain and the prealpine relief is reconstructed as a temperate broad-leaved mixed forest with acer, betula, carpinus, carya, pinus, quercus, tilia and ulmus. acknowledgments we are grateful to v. teodoridis, s. popova and a. bertini for the detailed comments that improved the manuscript. we thank also r. pini and m. donegana (cnr-idpa) for the help in pollen analysis. p. jimenez mejias is gratefully thanked for the material and information provided for the genus carex. references angiosperm phylogeny group [apg iii] (2009) an update of the angiosperm phylogeny group classification for the orders and families of flowering martinetto e. et al. 102 plants: apg iii. botanical journal of the linnean, 161, 105-121. basilici g., martinetto e., pavia g., violanti d. (1997) paleoenvironmental evolution in the pliocene marine-coastal succession of val chiusella (ivrea, nw italy). bollettino della società paleontologica italiana, 36 (1-2), 23-52. bertini a. (2001) pliocene climatic cycles and altitudinal forest development from 2.7 ma in the northern apennines (italy): evidences from the pollen record of the stirone section (5.1 to ca. 2.2 ma). geobios, 34, 253-265. bertini a. (2010) pliocene to pleistocene palynoflora and vegetation in italy: state of the art. quaternary international, 225, 5-24. bertini a., martinetto e. (2011) reconstruction of vegetation transects for the messinianpiacenzian of italy by means of comparative analysis of pollen, leaf and carpological records. palaeogeography, palaeoclimatology, palaeoecology, 304, 230-246. beug, h.j.b. (2004) leitfaden der pollenbestimmung für mitteleuropa und angrenzende gebiete. verlag dr. friedrich pfeil, münchen. birks h.h. (1973) modern macrofossil assemblages in lake sediments in minnesota. in: birks h.j.b. & west r.g. (eds.) quaternary plant ecology, 173189. blackwell. birks h.j.b., birks h.h. (2000) future uses of pollen analysis must include plant macrofossils. journal of biogeography, 27, 31-35. burrows c.j. (1980) long-distance dispersal of plant macrofossils. new zealand journal of botany, 18, 321-322. bůžek č., kvaček z., holý f. (1985) late pliocene palaeoenvironment and correlation of the vildštejn floristic complex within central europe. rozpravy československé akademie věd, řada matematických a přírodních věd, 95, 1-72. carraro f. (ed.) (1996) revisione del villafranchiano nell’area-tipo di villafranca d’asti. il quaternario 9(1), 5-120. ciangherotti a., esu d., lauta f. (2007) the villafranchian molluscan fauna from the steggio basin (treviso northeast italy): paleoecology and biochronology. ii quaternario, 13(1/2), 37-46. collinson m.e. (1983) accumulation of fruits and seeds in three small sedimentary environments and their palaeoecological implications. annals of botany, 52, 583-592. combourieu-nebut n. (1993) vegetation response to upper pliocene glacial/interglacial cyclicity in the central mediterranean. quaternary research, 40, 228-236. dieffenbacher-krall a.c., halteman w.a. (2000) the relationship of modern plant remains to water depth in alkaline lakes in new england. journal of paleolimnology, 24, 213-339. dorofeev p.i. (1974) cabombaceae, nymphaeaceae, ceratophyllaceae, etc. in: takhtajan a.l. (ed.) iskopaemye tsvetkovye rastenya sssr, 1 (fossil flowering plants of the ussr,1) nauka, leningrad. (in russian), pp. 52-88. ercole e., pistarino a., martinetto e., soldano a., siniscalco c. (in press) atlante fotografico dei frutti e dei semi della flora del piemonte e della valle d’aosta: cyperaceae. bollettino del museo regionale di scienze naturali di torino. farjon a. (1998) world checklist and bibliography of conifers. royal botanic gardens, kew. feruglio e. (1925) carta geologica delle tre venezie. foglio 25 “udine”. ufficio idrografico regio magistrato acque di venezia. feruglio e. (1929) nuove ricerche sul quaternario del friuli. giornale di geologia, 4, 1-36. fusco f. (2007) vegetation response to early pleistocene climatic cycles in the lamone valley (northern apennines, italy). review of palaeobotany and palynology, 145, 1-23. gadek p.a., alpers d.l., heslewood m.m., quinn c.j. (2000) relationships within cupressaceae sensu lato: a combined morphological and molecular approach. american journal of botany, 87, 10441057. galadini f., poli m.e., zanferrari a. (2005) seismogenic sources potentially responsible for earthquakes with m≥6 in the eastern southern alps (thieneudine sector, ne italy). geophysical journal international 161, 739-762. garzanti e., vezzoli g., andò s. (2011) paleogeographic and drainage changes during pleistocene glaciations (po plain, northern italy). earth science reviews, 105, 25-48. geissert f., gregor h.j., mai d.h. (1990) die “saugbaggerflora”, eine fruchtund samenflora aus dem grenzbereich miozän-pliozän von sessenheim im elsass (frankreich). documenta naturae, 57, 1-208. ghiotto p. (1995) contributo preliminare allo studio della macroflora del bacino lacustre "villafranchiano" di steggio (prealpi venete, italia settentrionale). il quaternario, 8(1), 193-202. ghiotto p. (2010) la carpoflora del bacino lacustre villafranchiano di steggio (treviso, prealpi orientali). bollettino del museo regionale di scienze naturali, 27(1), 3-99. girotti o., capasso barbato l., esu d., gliozzi, kotsakis a., martinetto e., petronio c., sardella r., squazzini e. (2003) the section of torre picchio (terni, umbria, central italy): a villafranchian site rich in mammals, molluscs, ostracods and plants. rivista italiana paleontologia stratigrafia, 109 (1), 77-98. grandesso p., vergerio p.p., villa i. (2000) stratigrafia ad isotopi stabili dello stronzio nel conglomerato del montello (miocene superiore) dell'area friulana. 80a riunione estiva società geologica italiana, trieste, settembre 2000, pp. 270-272. gregor h.-j. (1990) contribution to the late neogene and early quaternary floral history of the mediterranean. review of paleobotany and palynology, 62: 309-338. jiménez-mejías p. (2011) taxonomía y sistemática de las secciones ceratocystis y phacocystis del género carex en europa y la cuenca mediterránea. phd thesis. universidad pablo de olavide, sevilla, 380 pp. leroy s.a.g. (2007) progress in palynology of the gelasian-calabrian stages in europe: ten messages. revue de micropaleontologie, 50, 293-308. lona f., bertoldi r. (1973) la storia del plio-pleistocene italiano in alcune sequenze vegetazionali lacuan early pleistocene plant assemblage with east european affinity … 103 stri e marine. memorie accademia nazionale lincei, 11(3), 1-35. magri d., di rita f., palombo m.r. (2010) an early pleistocene interglacial record from an intermontane basin of central italy (scoppito, l’aquila). quaternary international, 225 (1), 106-113. mai d.h. (2010) carpological investigation of interglacial sediments from neumark-nord (geiseltal). palaeontographica abteilung b, 282, 99-187. mai d.h., walther h. (1988) die pliozänen floren von thüringen, deutsche demokratische republik. quartärpaläontologie, 7, 55-297. martinetto e. (1999) chronological framing of pliocene to early pleistocene plant macrofossil assemblages from northern italy. acta palaeobotanica, supplement 2, 503-511. martinetto e. (ed.) (2001) pliocene plants, environment and climate of northwestern italy. flora tertiaria mediterranea 4, 1-120. martinetto e., vassio e. (2010) reconstructing “plant community scenarios” by means of palaeocarpological data from the cenofita database, with an example from the ca’ viettone site (pliocene, northern italy): quaternary international, 225, 25-36. massari f., rio d., serandrei barbero r., asioli a., capraro l., fornaciari e., vergerio p. (2004) the environment of venice area in the past two million years. palaeogeography, palaeoclimatology, palaeoecology, 20, 273-308. monegato g., stefani c. (2010) stratigraphy and evolution of a long-lived fluvial system in the southeastern alps (ne italy): the tagliamento conglomerate. austrian journal earth science, 103(2), 33-49. monegato g., vezzoli g. (2011) post-messinian drainage changes triggered by tectonic and climatic events (eastern southern alps, italy). sedimentary geology, 239, 188-198. monegato g., lowick s.e., ravazzi c., banino r., donegana m., preusser f. (2010) middle to late pleistocene chronology and palaeoenvironmental evolution of the south-eastern alpine foreland: the valeriano creek succession (ne italy). journal of quaternary science, 25, 617-632. monegato g., ravazzi c., donegana m., pini r., calderoni g., wick l. (2007) evidence of a two-fold glacial advance during the last glacial maximum in the tagliamento end moraine system (eastern alps). quaternary research, 68(2), 284-302. moore p.d., webb j.a., collinson m.e. (1991) pollen analysis. blackwell scientific publications: oxford. muttoni g., ravazzi c., breda m., pini r., laj c., kissel c., mazaud a., garzanti e. (2007) magnetostratigraphic dating of an intensification of glacial activity in the southern italian alps during marine isotope stage 22. quaternary research, 67, 161-173. muttoni g., scardia g., kent d. (2010) human migration into europe during the late early pleistocene climate transition. palaeogeography, palaeoclimatology, palaeoecology, 296, 79-93. nikitin v.p. (2006) paleocarpology and stratigraphy of the paleogene and neogene strata in asian russia. academic publishing house geo, novosibirsk, russia. paronuzzi p., tonon m. (1992) il bacino lacustre villafranchiano di steggio (prealpi venete, treviso): primi dati stratigrafici ed evidenze neotettoniche. il quaternario, 5(2), 251-268. paiero g., monegato g. (2003) the pleistocene evolution of arzino alluvial fan and western part of tagliamento morainic amphitheatre (friuli, ne italy). il quaternario, 16(2), 185-193. pini r., ravazzi c., reimer p.j. (2010) the vegetation and climate history of the last glacial cycle in a new pollen record from fimon lake (southern alpine foreland, n-italy). quaternary science reviews, 29, 3115-3137. poli m.e., zanferrari a., monegato g. (2009) geometria, cinematica e attività pliocenico-quaternaria del sistema di sovrascorrimenti arba-ragogna (alpi meridionali orientali, italia ne). rendiconti online società geologica italiana, 5, 172-175. punt w., blackmore s. (1976-2004) the northwest european pollen flora. vol. i-viii, elsevier publishing company. ravazzi c., rossignol-strick m. (1995) vegetation change in a climatic cycle of early pleistocene age in the leffe basin (northern italy). palaeogeography, palaeoclimatology, palaeoecology, 117, 105-122. ravazzi c., pini r., breda m., martinetto e., muttoni g., chiesa s., confortini f., egli r. (2005) the lacustrine deposits of fornaci di ranica (late early pleistocene, italian pre-alps): stratigraphy, palaeoenvironment and geological evolution. quaternary international, 131, 35-58. ravazzi c., pini r., breda m. (2009) reconstructing the palaeoenvironments of the early pleistocene mammal faunas from the pollen preserved on fossil bones. quaternary science reviews 28, 29402954. reid c., reid e.m. (1915) the pliocene floras of the dutchprussian border: mededdeelingen van rijksopsporing van delfstoffen, 6, 1-178. reille m. (1992-1995) pollen et spores d’europe et d’afrique du nord. laboratoire de botanique historique et palynologie, marseille. rio d., channell j.e.t., bertoldi r., poli m.s., vergerio p.p., raffi i., sprovieri r., thunnell r.c. (1997) pliocene sapropels in the northern adriatic area: chronology and paleoenvironmental significance. palaeogeogeography, palaeoclimatology, palaeoecology, 135, 1-25. sala b., tonon m. (1992) eucladoceros cf. senezensis deperet 1910 in un bacino lacustre villafranchiano a steggio (possagno, treviso, italia nord-orientale). il quaternario, 5(1), 11-16. sims h.j., cassara j.a. (2009) the taphonomic fidelity of seed size in fossil assemblages: a live-dead case study. palaios, 24 (6), 387-393. stefanini g. (1915) il neogene veneto. memorie istituto di geologia e mineralogia regia università di padova, 3, 340-624. stockmarr j. (1971) tablets with spores used in absolute pollen analysis. pollen et spores, 13, 615-621. tellini a. (1892) descrizione geologica della tavoletta "majano". in alto, 3, 18-25, 44-48,76-81. thomasson j.r. (1991) sediment-borne ‘‘seeds’’ from sand creek, northwestern kansas: taphonomic significance and paleoecological and paleoenvimartinetto e. et al. 104 ronmental implications. palaeogeography, palaeoclimatology, palaeoecology, 85, 213-225. vassio e. (2012) palaeovegetation reconstructions and palaeoclimatic interpretations of quaternary carpological assemblages with an actuopalaeobotanical approach, phd thesis, dipartimento di scienze della terra, università degli studi di torino, torino, 281 pp. velichkevich f.y., zastawniak e. (2003) the pliocene flora of kholmech, south-eastern belarus and its correlation with other pliocene floras of europe. acta palaeobotanica, 43(2), 137-259. velichkevich f.y., zastawniak e. (2006) atlas of the pleistocene vascular plant macrofossils of central and eastern europe. part i pteridophytes and monocotyledons: w. szafer institute of botany, polish academy of sciences, kraków. velichkevich f.y., zastawniak e. (2007) the state of investigation of the upper pliocene dvorets flora (se belarus). acta palaeobotanica, 47(1), 261-273. velichkevich f.y., zastawniak e. (2009) atlas of the pleistocene vascular plant macrofossils of central and eastern europe part 2: herbaceous dicotyledones: w. szafer institute of botany, polish academy of sciences, kraków. venturini s., tunis g. (1992) la composizione dei conglomerati cenozoici del friuli: dati preliminari. studi geologici camerti, vol. spec. 2(crop 1/1°), 285-295. verloove f. (2010) studies in italian cyperaceae 1. eleocharis pellucida, new to europe, naturalised in piemonte (italy). webbia, 65, 133-140. watts w.a., winter t.c. (1966) plant macrofossils from kirchner marsh, minnesota, a paleoecology study. bulletin of geological society of america, 77, 1339-1360. zanferrari a., avigliano r., grandesso p., monegato g., paiero g., poli m.e., stefani c. (2008) note illustrative della carta geologica d’italia alla scala 1:50.000: foglio 065 “maniago”. apat-servizio geologico d’italia regione autonoma friuli venezia giulia. zanni m., ravazzi c. 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<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> /ita (utilizzare queste impostazioni per creare documenti adobe pdf adatti per visualizzare e stampare documenti aziendali in modo affidabile. i documenti pdf creati possono essere aperti con acrobat e adobe reader 5.0 e versioni successive.) /enu (use these settings to create adobe pdf documents suitable for reliable viewing and printing of business documents. created pdf documents can be opened with acrobat and adobe reader 5.0 and later.) >> >> setdistillerparams << /hwresolution [1200 1200] /pagesize [396.850 566.929] >> setpagedevice 01fioraso_spagnolo i block stream del massiccio peridotitico di lanzo (alpi nord-occidentali) gianfranco fioraso & gianluca spagnolo cnr istituto di geoscienze e georisorse, via valperga caluso 35 10125 torino. e-mail: <g.fioraso@csg.to.cnr.it> riassunto: g. fioraso & g. spagnolo, i block stream del massiccio peridotitico di lanzo (alpi nord-occidentali). (it issn 03943356, 2009). il massiccio peridotitico di lanzo (mpl), oltre a costituire una della maggiori masse di rocce di mantello esistenti al mondo, ospita un'eccezionale concentrazione di block stream (157), costituiti da coltri detritiche a grossi blocchi prive di matrice organizzate a formare lingue che in alcuni casi giungono con la propria fronte a sfiorare gli attuali fondovalli. il mpl, esteso su una superficie di 150 km2, è localizzato lungo il margine interno della catena alpina tra la bassa valle di lanzo e la bassa valle di susa. il massiccio è suddiviso in tre settori, meridionale (55 km2), centrale (90 km2) e settentrionale (5 km2), separati da due ampie zone di taglio con andamento nwse. altre fasce di deformazione sono localizzate lungo il margine occidentale del massiccio in corrispondenza del contatto con le contigue unità tettoniche della catena alpina. i litotipi affioranti nel mpl sono rappresentati da peridotiti a plagioclasio alle quali si associano subordinate lherzoliti a spinello, harzburgiti e duniti. le peridotiti costituiscono il nucleo dei tre settori in cui è suddiviso il mpl, mentre procedendo verso le zone periferiche del massiccio le rocce di mantello sono caratterizzate da un progressivo incremento del grado di serpentinizzazione. i block stream, localizzati essenzialmente in corrispondenza delle aree di affioramento delle peridotiti, si estendono complessivamente su una superficie di 14,67 km2, pari al 9,8% dell'area occupata dal mpl. i block stream si concentrano nel settore centro-settentrionale del massiccio, mentre a sud del monte arpone il numero e le dimensioni delle lingue detritiche decrescono sensibilmente. la superficie unitaria dei block stream è compresa tra 0,3 e 91,6 ha, a fronte di una lunghezza massima di 2,23 km. le lingue detritiche hanno uno sviluppo altimetrico compreso tra i 1645 e i 470 m s.l.m., con un dislivello medio di 870 m. la pendenza media della superficie dei singoli fenomeni è compresa tra 13° e 44°; il 76% dei block stream ha tuttavia una pendenza media compresa tra 23° e 32°. la porzione superficiale dei block stream è costituita da una coltre detritica a grossi blocchi priva di matrice con tessitura open-work; la potenza è piuttosto esigua ed è compresa tra 1 e 7 m. i blocchi, da angolosi a subangolosi, hanno un diametro medio variabile tra 0,2 e 1,8 m e sono caratterizzati da una struttura di tipo coarsening-upward. la litologia dei blocchi è rappresentata da peridotiti fresche e/o debolmente serpentinitizzate e, subordinatamente, da serpentiniti e da minime percentuali di rocce gabbriche e basaltiche, chiaro indizio di una provenienza esclusivamente locale dei frammenti rocciosi. il complesso detritico poggia, tramite un contatto netto ad andamento irregolare, su un materasso di sedimenti eterogenei con tessitura matrix-supported e con uno spessore massimo accertato di 22 m; la matrice è costituita da una miscela di sabbia, silt e argilla montmorillonitica in proporzioni estremamente variabili; subordinatamente sono presenti clasti e blocchi di dimensioni inferiori al metro. la superficie delle coltri detritiche è articolata da dorsali e depressioni ad andamento longitudinale, dorsali trasversali, lobi, depressioni chiude e semiaperte: tali morfologie sono in alcuni casi legate a movimenti gravitativi sviluppati internamente alla matrice e al sovrastante complesso detritico, in altri sono da ricondurre alla rimozione della frazione fine del sedimento ad opera dell'intensa circolazione subdetritica sviluppata all'interno dei block stream. nel tratto terminale della valle di lanzo le fronti dei block stream intersecano a varie quote una serie di unità di modellamento fluviale di età compresa tra il pleistocene medio e l'olocene, giungendo in taluni casi a sfiorare l'alveo del t. stura di lanzo. inoltre, la presenza di locali cedimenti osservati su manufatti antropici ospitati sulla superficie di alcune lingue detritiche indica che alcuni block stream risultano tuttora in lenta evoluzione. la localizzazione di queste fenomenologie in corrispondenza degli areali di affioramento del substrato peridotitico rispecchia l'intensità, la durata e le particolari modalità di sviluppo dei fenomeni di alterazione sviluppati a spese delle rocce di mantello, in un'area della catena alpina peraltro risparmiata dal glacialismo pleistocenico. i block stream rappresentano quindi il prodotto dell'interazione tra i fenomeni di degradazione del substrato e i processi di rielaborazione, selezione e concentrazione dei prodotti pedegenetici, con l'ulteriore contributo di fenomeni di creep gravitativo, protrattisi per un considerevole lasso di tempo, presumibilmente già a partire dalle fasi terminali del pleistocene inferiore. abstract: g. fioraso & g. spagnolo, the block streams of the lanzo peridotite massif (north-western alps). (it issn 0394-3356, 2009). the lanzo peridotite massif (lpm) is one of the largest outcrops of ophiolitic peridotites in the world and it is well known because of the freshness of its mantle rocks; furthermore, the lpm represents a peculiarity also for the extraordinary and unusual presence of a large number of block streams (157), consisting of streams of angular blocks resting over a thick succession of fine sediments. the lpm extends for about 150 km2 along the internal margin of the western alps, 35 km north-west of turin, between the lower susa valley and the lower viù valley; it is commonly divided into a southern body (55 km2), a central body (90 km2) and a northern body (5 km2), which are separated by two broad mylonitic and serpentinized shear zones with a nw-se direction. other tectonic shear zones are localized in the marginal and more serpentinized parts of the lpm, corresponding to the contacts with the adjacent tectonic units of the alpine chain (i.e. piemontese zone and sesia-lanzo zone). the lpm is mainly composed of massive weakly serpentinized plagioclase peridotites with minor spinel peridotites and granular harzburgites. plagioclase peridotites are well exposed in the core of the three bodies, whereas in the peripherical areas peridotites gradually become more serpentinized till turning into massive serpentinites. spinel lherzolites, spinel dunites and harzburgites are subordinated; all the peridotites are frequently intruded by various gabbroic veins and dykes and sometimes by basalts. block streams mainly extend on lherzolite outcropping areas, covering on the whole 14.67 km2, equivalent to 9.8% of the lpm extent. block streams are located chiefly on the northern and central body of the lpm, along the slopes of the mount colombano mount corno and mount colombano mount lera ridges; another notable group of block streams is localized between col del lys and colle portia, whereas in the southern areas of the lpm such features are rather scattered. block streams range in elevation between 1645 and 470 m a.s.l., with a maximum relief of 870 m; they take up an area ranging from 0.3 to 91.6 ha, with a maximum length of 2.23 km and a mean slope of 13÷44°; nevertheless 76% of block streams have a mean slope of 23÷32°. block streams show an upper layer made of interlocked coarse angular to subangular blocks with no fine matrix, resulting in an openwork framework. blocky cover has a relatively uniform thickness ranging between 1 and 7 m, commonly with a coarsening-upward texture. detrital elements range between 0.2 and 1.8 m in diameter and derive exclusively from rocks belonging to the lpm. the upper il quaternario italian journal of quaternary sciences 22(1), 2009 3-22 4 g. fioraso & g. spagnolo 1. introduzione il massiccio peridotitico di lanzo (mpl), ubicato nel settore interno dell'arco alpino occidentale, oltre a costituire una delle più estese masse di peridotiti di mantello esistenti al mondo (~150 km2) (boudier, 1978), ospita un'eccezionale concentrazione di block stream che coprono complessivamente una superficie di 14,67 km2, pari al 9,8% dell'area di affioramento del mpl. i block stream sono costituiti in superficie da un complesso detritico a grossi blocchi, privo di matrice, poggiante su un potente materasso di sedimenti sabbioso-siltosoargillosi (complesso inferiore); il più delle volte i block stream danno luogo a lingue che in alcuni casi giungono con la propria fronte a sfiorare gli attuali fondovalle. lo sviluppo di questi fenomeni è spazialmente vincolato dalla presenza di un substrato costituito da peridotiti non metamorfosate o solo parzialmente serpentinizzate. nell'arco alpino e appenninico non sono riscontrabili altri esempi di block stream confrontabili, per numero, dimensioni e morfologia, con quelli presenti nel mpl. raggruppamenti di block stream di piccole dimensioni sono stati segnalati e descritti da conti (1940) e da firpo et al. (2005; 2006) sulle serpentiniti del gruppo di voltri (massiccio del monte beigua) nelle alpi liguri; altri block stream sono inoltre localizzati nei pressi del monte nero e del monte aiona, in val d'aveto (appennino ligure) e, anche in questo caso, si sono sviluppati a spese di un substrato ofiolitico costituito da lherzoliti e serpentiniti appartenenti all'unità aiona-ragola (liguridi esterne). le lingue detritiche ospitate nel massiccio di lanzo sono state descritte e interpretate da capello (1963) come il prodotto di fenomeni criogenici, in analogia con altre manifestazioni d'alta quota (interpretabili come rock glacier) individuate dallo stesso autore nei settori altimetricamente più elevati delle alpi graie. la distribuzione delle coltri detritiche fino a quote significativamente basse (470 m s.l.m.), l'estrema omogeneità litologica dei blocchi e la concomitante presenza di diffusi e profondi fenomeni di alterazione sviluppati a spese del substrato peridotitico (natale, 1972; miè & natale, 1978) suggeriscono tuttavia un forte contributo nell'evoluzione dei block stream da parte di fenomeni non necessariamente connessi all'ambiente periglaciale. al fine di chiarire i meccanismi genetici e di delineare i rapporti con l'evoluzione pliocenico-quaternaria di questo settore dell'arco alpino è stato effettuato un dettagliato studio esteso a tutto il mpl, che ha consentito di individuare e cartografare 157 block stream, ciascuno dei quali è stato analizzato sotto il profilo morfometrico, morfologico e stratigrafico; per una parte di essi, contraddistinti da ottimali condizioni di esposizione e di affioramento, è stata inoltre effettuata una dettagliata caratterizzazione geologica, micromorfologica e sedimentologica. vengono qui presentati i primi risultati di questo studio che ha permesso di evidenziare l'importante contributo fornito dai processi di alterazione delle peridotiti nello sviluppo delle coltri detritiche e di definire il ruolo svolto dalla gravità e dalla circolazione idrica, superficiale e profonda, nell'evoluzione di queste inusuali fenomenologie di versante. sulla scorta delle informazioni desunte dai rapporti con le altre unità pliocenico-quaternarie distribuite ai margini di questo settore dell'arco alpino, viene inoltre effettuato un inquadramento dei fenomeni descritti nel più ampio contesto evolutivo recente del mpl, situato nel nevralgico punto di giunzione tra la catena alpina e i rilievi del bacino terziario piemontese. 2. inquadramento geologico e morfoclimatico il massiccio peridotitico di lanzo è localizzato alcune decine di chilometri a nord-ovest della città di torino nel settore interno della catena alpina occidentale, tra la bassa valle di viù e la bassa valle di susa (fig. 1). verso ovest il massiccio è bordato da unità di crosta oceanica (ofioliti di alta pressione e relativi calcescisti di copertura) della zona piemontese auct., mentre verso nord è delimitato dalle unità di crosta continentale della zona sesia-lanzo (nicolas, 1974; spalla et al., 1983; pognante, 1989). verso est e verso sud il margine del massiccio è invece rispettivamente sepolto dalla successione fluviale quaternaria della pianura padana occidentale e dai depositi glaciali dell'anfiteatro morenico di rivoli-avigliana. il mpl è stato interpretato come un'originaria sezione di mantello litosferico sottocontinentale che ha registrato una complessa storia evolutiva, determinata layer rests on a matrix-supported unstratified diamicton, consisting of an heterogeneous mixture of silt, sand, clay and gravel and containing scattered subangular to subrounded boulders; with an ascertained thickness ranging between 0.5 and 22 m at least, diamicton in turn rest above the bedrock. below open-work mantle a notable and perennial subdetrital runoff develops with discharge fluctuation parallel to the local pluviometric and climatic trends. block streams commonly exhibit a complex variety of morphological features such as longitudinal ridges and furrows, transversal ridges, narrow steep lobes and hollows: these features are caused by downslope differential movements of the blocky mantle or by the quick removal of the underlying matrix by the subdetrital water circulation. in the lower viù valley (i.e. germagnano) the fronts of few block streams crosscut fluvio-glacial and fluvial units (ranging between middle pleistocene to holocene in age) reaching the actual flood plain of the stura di lanzo stream. moreover collapse features locally affecting anthropic structures show that such phenomena in few cases are still in a steady slow evolution. according to spatial and altimetric distribution, sedimentologic characters and morphologic features, block streams of lpm may be regarded as creep-dominated phenomena involving sandy-silty and clayey-silty matrix. the development of such blocky-covered features, preferably regarding lherzolitic substratum, reflect the particular weathering process affecting peridotitic rocks and the absence of glacial modelling in this sector of the alpine chain: this allowed the uninterrupted long-term chemical-fisical breakdown of parent rocks, accompained by reworking of pedogenetic products by size sorting and concentration processes operating along slopes and in valley bottoms. parole chiave: block stream, peridotite, alterazione, creep, alpi occidentali. keywords: block stream, peridotite, weathering, creep, western alps. dapprima da differenti processi di trasformazione avvenuti durante la progressiva esumazione verso il fondo del bacino oceanico della tetide ligure giurassica (bacino ligure-piemontese) (piccardo et al., 2004) e, successivamente, per effetto del metamorfismo alpino. il massiccio è suddiviso in tre settori, meridionale (55 km2), centrale (90 km2) e settentrionale (5 km2), rispettivamente separati da due ampie fasce milonitiche orientate in direzione nw-se e interessate da diffusi processi di serpentinizzazione (boudier & nicolas, 1972; elter 5i block stream del massiccio peridotitico di lanzo et al., 2005; balestro et al., 2009) (fig. 2): la prima fascia corrisponde alla zona di taglio colle lunella colle portia (boudier, 1978), che separa il settore centrale da quello meridionale del mpl; la seconda viene intercettata dalla dorsale spartiacque stura di viù ceronda lungo una direttrice che si estende approssimativamente tra gli abitati di traves e di vallo, isolando il settore del monte corno dal resto del massiccio (boudier, 1978; bodinier et al., 1991; kaczmarek & muntener, 2005). la zona di taglio colle lunella colle portia fig. 1 inquadramento geologico del massiccio di lanzo (modificato da dal piaz et al., 1990). 1) depositi fluviali e fluvioglaciali quaternari della pianura padana occidentale; 2) depositi glaciali pleistocenici (amra = anfiteatro morenico di rivoli-avigliana; ami = anfiteatro morenico di ivrea); 3) successione oligo-miocenica della collina di torino; 4) zona del gran s. bernardo (dominio pennidico); 5) massiccio d’ambin (dominio pennidico); 6) massicci cristallini interni del dominio pennidico (gp = gran paradiso; dm = dora-maira); 7) calcescisti ofiolitici della zona piemontese; 8) zona sesia-lanzo (sistema austroalpino); 9) massiccio peridotitico di lanzo; 10) zona del canavese; 11) zona ivrea-verbano (dominio sudalpino). structural sketch map of the italian western alps (from dal piaz et al., 1990, modified). 1) quaternary fluvial and glaciofluvial deposits of the western po plain; 2) pleistocene glacial deposits (amra = rivoli-avigliana morainic amphitheatre; ami = ivrea morainic amphitheatre); 3) oligo-miocene deposits of the torino hill (piemontese-ligurian tertiary basin); 4) grand st. bernard zone (pennidic domain); 5) ambin massif (pennidic domain); 6) internal crystalline massifs of the pennidic domain (gp = gran paradiso; dm = doramaira); 7) ophiolite-bearing calcschists of the piemontese zone; 8) sesia-lanzo zone (austroalpine system); 9) lanzo peridotitic massif; 10) canavese zone; 11) ivrea-verbano zone (southalpine domain). 6 fig. 2 schema geologico del massiccio peridotitico di lanzo (modificato da debelmas et al., 1980) e distribuzione dei block stream. 1) lherzolit i , harzburgiti e duniti (massiccio di lanzo); 2) serpentiniti e peridotiti serpentinizzate (zona piemontese e massiccio di lanzo); 3) calcescisti (zona piemontese); 4) metabasiti (zona piemontese); 5) “gneiss minuti” (zona sesia-lanzo); 6) depositi glaciali pleistocenici; 7) depositi fluviali quaternari; 8) block stream e relativo numero identificativo; 9) contatti stratigrafici; 10) contatti stratigrafici transizionali; 11) faglie; 12) punti di campionamento; 13) cave di magnesite. ztl = zona di taglio del colle del lis; ztlp = zona di taglio colle lunella colle portia; ztc = zona di taglio del monte colombano. geologic map of the lanzo peridotitic massif (modified from debelmas et al., 1980) with distribution of block streams. 1) lherzolite, harzburgite and dunite (lanzo massif); 2) serpentinites and serpentinized peridotites (piemontese zone and lanzo massif); 3) calcschists (piemontese zone); 4) metabasites (piemontese zone); 5) “gneiss minuti” (sesia-lanzo zone); 6) pleistocene glacial deposits; 7) quaternary fluvial deposits; 8) block streams with identification codes; 9) stratigraphic boundaries; 10) transitional stratigraphic boundaries; 11) faults; 12) sampling points; 13) magnesite quarries. ztl = colle del lis shear zone; ztlp = colle lunella colle portia shear zone; ztc = monte colombano shear zone. g. fioraso & g. spagnolo 7 costituisce la giunzione di altre due zone di taglio di estensione regionale a direzione media n-s (zone di taglio del colle del lis e del monte colombano) che segnano il limite occidentale del massiccio peridotitico. il mpl è costituito da estesi volumi di rocce caratterizzate dall’eccezionale preservazione delle originarie associazioni mineralogiche mantelliche ed oceaniche. i litotipi affioranti sono essenzialmente rappresentati da peridotiti a plagioclasio alle quali si associano subordinate lherzoliti a spinello, harzburgiti e duniti. le peridotiti sono frequentemente attraversate da bande di pirosseniti a spinello che conferiscono alla roccia una spiccata struttura anisotropa "a bande" (boudier 1976; bodinier et al., 1991); sono inoltre presenti filoni di gabbri e rari filoni basaltici che tagliano tutte le strutture presenti nella roccia. i nuclei peridotitici sono attraversati da sistemi di fratture ad andamento regolare e con spaziatura media compresa tra 0,5 e 1,5 m che danno luogo ad un reticolo a geometria ortogonale o romboedrica e che, in combinazione con la struttura a bande della roccia, ripartiscono il substrato in blocchi isodiametrici di forma cubica, prismatica e cuneiforme. i rilievi che costituiscono il mpl si elevano fino a quote comprese tra i 1000 e i 1600 m, culminando con i 1658 m del monte colombano (fig. 2). i versanti hanno un profilo dolce e regolare e sono pressoché privi di pareti rocciose; in prossimità delle creste spartiacque sono localmente presenti piccole scarpate o tor di modesta altezza (non più di 15÷20 m) in cui si osserva uno spiccato allentamento del substrato. a ovest il massiccio di lanzo è delimitato dalle incisioni dei torrenti richiaglio e messa (a loro volta separate dalla profonda depressione morfostrutturale del colle del lis) e a nord dal solco del t. stura di lanzo. alla base dei rilievi che costituiscono i versanti sud-orientali del mpl si innestano estesi e potenti conoidi torrentizi e di debris flow che si raccordano ai depositi fluviali che costituiscono il margine occidentale della pianura padana. attualmente tutto il reticolato idrografico è interessato da un'accentuata fase di approfondimento erosivo in risposta al sollevamento tardo-quaternario che ha interessato il tratto di pianura interposto tra il settore interno dell'arco alpino e la collina di torino. sui rilievi del mpl non sono mai state rinvenute forme e depositi riferibili alla morfogenesi glaciale; solo nel settore meridionale del massiccio, in prossimità della confluenza del t. messa nella valle di susa, sono conservati depositi di età pleistocenica medio-superiore attribuiti alle diverse fasi di espansione del ghiacciaio della dora riparia (petrucci, 1970; carraro et al., 2005; balestro et al., 2009) e che costituiscono il margine laterale sinistro dell’anfiteatro morenico di rivoliavigliana (fig. 1). dal punto di vista climatico l’area di studio è caratterizzata da una forte stagionalità, con un regime pluviometrico di tipo continentale prealpino ad andamento bimodale, con un massimo principale primaverile ed uno secondario autunnale, nonché da un minimo principale nel periodo invernale (biancotti et al., 1998). i dati registrati alla stazione di usseglio (1265 m s.l.m.), ubicata nella media valle di viù, e relativi al periodo 1951-1986 indicano precipitazioni medie annue di 1096 mm; la temperatura media annua dell'aria è invece di 5,1 °c. 3. l'alterazione del substrato peridotitico le rocce che compongono il mpl sono interessate da estesi e profondi fenomeni di alterazione chimicofisica, osservabili soprattutto nelle aree di affioramento delle peridotiti. sui rilievi del massiccio di lanzo l'alterazione del substrato è più marcata rispetto ad altri settori delle alpi occidentali: ciò è dovuto da un lato all’elevata degradabilità intrinseca delle peridotiti, dall’altro all’assenza di fenomeni di esarazione glaciale che hanno invece diffusamente e ripetutamente operato nei settori più interni della catena alpina. l’alterazione è causata dall'idrolisi, dall'ossidazione e dalla lisciviazione dei minerali femici (in primo luogo olivina e pirosseni) che costituiscono le peridotiti. l'evoluzione del fenomeno è dominata dal comportamento differenziale dell’olivina, estremamente più suscettibile all'alterazione rispetto ai pirosseni relativamente più resistenti (goldich, 1938; hay, 1959). il processo si sviluppa inizialmente con un’alterazione periferica dei cristalli di olivina e di clinopirosseno, accompagnata dalla formazione di sottili frange di talco; successivamente l'alterazione prosegue con la rapida e completa trasformazione dell’olivina in un feltro di colore giallo-arancio, costituito da un aggregato di argille smectitiche in cui sono disseminati granuli di maghemite (miè & natale, 1978). l’alterazione dei pirosseni procede invece più lentamente e risulta quasi sempre incompleta, soprattutto per quanto riguarda l’ortopirosseno. i fenomeni di degradazione, sin dalle prime fasi, sono accompagnati dalla rapida lisciviazione del mg, del ca e del si, che determina un sensibile decremento del peso e del volume della roccia e un corrispondente aumento dei valori di permeabilità. talvolta l’argillificazione dell’olivina, che costituisce in media il 40% del volume della peridotite, può comportare la perdita pressoché totale di coesione della roccia, che in alcuni casi si presenta come un ammasso sabbioso-argilloso estremamante friabile: questo aspetto è chiaramente osservabile in corrispondenza delle numerose cave di magnesite attualmente dismesse, ubicate alla base dei versanti sud-orientali del mpl, ove maggiori sono stati gli effetti dell'alterazione (fig. 2). il diverso comportamento dei minerali femici si esprime anche nello spiccato carattere morfoselettivo dei processi di alterazione: la superficie degli affioramenti e dei blocchi peridotitici è infatti piuttosto scabra, con microrilievi di 5÷15 mm di altezza costituiti dai cristalli di ortopirosseno inalterati, separati da fossette e microdepressioni che ricalcano la morfologia degli originari cristalli di olivina. la degradazione chimica del substrato, oltre ad essere controllata dal pattern mineralogico, è influenzata anche dall'anisotropia delle peridotiti dovuta alla presenza dei livelli pirossenitici, di spessore compreso tra 1 e 20 cm, che si alternano a livelli maggiormente ricchi in olivina, meno resistenti, e che costituiscono pertanto vie preferenziali per la propagazione dell’alterazione fino a profondità di 8÷12 m. il reticolo di faglie e fratture garantisce inoltre il rapido deflusso all'interno del substrato delle acque meteoriche necessarie per lo sviluppo dell'idrolisi dei minerali; i processi di alterazione hanno in tal modo la possibilità di intaccare i blocchi di roccia su più lati in corrispondenza delle superfici di discontinuità per poi i block stream del massiccio peridotitico di lanzo 8 procedere, con andamento centripeto, verso il nucleo. vengono in tal modo a formarsi elementi rocciosi sferoidali di taglia pluri-decimetrica immersi in una matrice sabbioso-argillosa. internamente gli sferoidi si presentano inalterati, mentre all'esterno sono talvolta presenti strutture da esfoliazione costituite da scaglie di roccia di spessore millimetrico (1÷5 mm) a struttura concentrica. sulla superficie degli affioramenti e delle coltri detritiche è possibile osservare come al di sotto di una sottile patina di ossidazione la roccia peridotitica appaia assolutamente inalterata: ciò suggerirebbe l'ipotesi di una maggiore efficacia dell'alterazione in presenza di un substrato già parzialmente interessato da processi di degradazione o mascherato da coltri colluviali in grado di ritenere per lunghi periodi l’acqua di percolazione e l'umidità necessarie allo sviluppo dell'idrolisi dei minerali femici. in superficie prevarrebbe quindi il disfacimento fisico-meccanico della roccia, sviluppato essenzialmente attraverso tipici meccanismi di frost shattering (twidale & vidal romanì, 2005). analisi mineralogiche effettuate da mié & natale (1978) su campioni prelevati all'interno delle coltri di alterazione nel settore centro-meridionale del mpl hanno evidenziato che la frazione fine è costituita da argilla montmorillonitica più o meno ferrifera frammista ad altri prodotti di neoformazione quali talco, granuli di maghemite e goethite; sono inoltre presenti residui del processo di alterazione costituiti da frammenti di serpentinite, cristalli di pirosseno e di olivina parzialmente argillificati e granuli di magnetite, antigorite e spinello. la matrice è inoltre diffusamente attraversata da patine nero-bluastre costituite da ossidi di manganese e talvolta da vene di spessore millimetrico, di analoga composizione, irregolarmente distribuite all'interno dei sedimenti. i caratteri e l’entità dell’alterazione nel mpl non sono uniformi, ma variano in funzione del contesto morfologico locale. lungo le dorsali spartiacque e nei settori più acclivi dei versanti prevalgono i fenomeni erosivi legati al deflusso delle acque meteoriche che periodicamente rimuovono i prodotti di alterazione mettendo a nudo il substrato; solo localmente sono conservati lembi di coltri eluvio-colluviali di spessore generalmente inferiore al metro. alla base dei versanti, dove minori sono gli effetti dell'erosione, i processi di alterazione possono invece svilupparsi in tutta la loro completezza, coinvolgendo sia i potenti conoidi costituiti dai prodotti di rielaborazione delle alteriti provenienti dai settori a monte, sia il substrato roccioso fino a profondità che in taluni casi possono raggiungere le decine di metri. nel complesso le coltri di alterazione mostrano una tipica colorazione variabile da gialloocracea a rosso-violacea con indici di colore compresi tra 5yr e 10r. secondo natale (1972) e miè & natale (1978) l'intensità e la durata dei fenomeni di alterazione delle peridotiti sarebbero inoltre all'origine delle estese mineralizzazioni a magnesite, dolomite e opale ospitate nelle porzioni più superficial i del substrato e, subordinatamente, all'interno dei depositi che costituiscono i conoidi pedemontani (fig. 2). 4. caratterizzazione morfometrica e distribuzione dei block stream i block stream sono costituiti in superficie da coltri detritiche prive di matrice distribuite lungo i versanti a quote comprese tra i 1645 e i 470 m, con un dislivello unitario massimo pari a 870 m (fig. 2) (tab. i). a sud di germagnano il detrito giunge in più punti a sfiorare l'alveo del t. stura di lanzo; in altri casi, invece, le fronti dei block stream si innestano, talvolta sopravanzandoli, agli apici dei conoidi che bordano il mpl, come accade ad esempio nei settori di vallo, varisella e givoletto (fig. 2). la configurazione planimetrica dei block stream è piuttosto articolata ed è controllata essenzialmente dall'andamento morfo-topografico dei rilievi. nei settori di versante altimetricamente più elevati le coltri detritiche appaiono arealmente molto estese, talvolta fino a raggiungere le creste spartiacque, e assumono l’aspetto di block field di forma irregolare. la larghezza dei campi di detrito varia da poche centinaia di metri fino ad oltre un chilometro, mentre i limiti esterni, spesso mascherati dalla vegetazione arbustiva ed arborea, sono quasi sempre sfrangiati sfumando gradualmente nella circostante copertura detritico-colluviale. verso valle le coltri detritiche si restringono e si incanalano progressivamente lungo gli avvallamenti e le incisioni topografiche, assumendo l'aspetto di vere e proprie lingue talvolta con un andamento marcatamente sinuoso (fig. 3). procedendo verso valle la larghezza delle coltri detritiche decresce gradualmente essendo generalmente compresa tra 200 m e 10÷15 m; i limiti sono netti e ben marcati e le fronti detritiche spesso sopravanzano e mascherano le irregolarità del substrato. diversamente dai settori di testata, ove i block field sono contraddistinti da un profilo trasversale concavo, le lingue detritiche assumono un aspetto turgido con un profilo convesso, risultando talvolta sopraelevate di 3÷5 m rispetto alle aree circostanti. i block stream possono assumere molteplici aspetti: configurarsi in pianta come semplici fasce detritiche allungate verso valle, dare luogo a morfologie "a goccia" oppure mostrare un aspetto ramificato per effetto della confluenza di due o più lingue con tipiche biforcazioni a "y" (fig. 3 e 4). in taluni casi sono stati rilevati veri e propri fenomeni di "trasfluenza" in corrispondenza dei quali si è verificato il trasferimento di tab. i parametri morfometrici dei block stream. morphometric parameters of the block streams. smin/max superficie minima e massima 0,3 ÷ 91,6 ha smean superficie media 9,3 ha hmax altezza massima 590 ÷ 1645 m s.l.m. hmin altezza minima 470 ÷ 1345 m s.l.m. ∆h dislivello minimo e massimo 60 ÷ 870 m lmin/max lunghezza minima e massima 88 ÷ 2227 m lmean lunghezza media 702 m w larghezza 10 ÷ 100 m α pendenza media 13,3° ÷ 44,8° g. fioraso & g. spagnolo materiale detritico da un block stream all’altro (n. 43; fig. 5). gran parte dei 157 block stream cartografati sono localizzati sui rilievi situati a est del colle del lis, lungo i versanti che si dipartono dalle dorsali spartiacque monte arpone monte curt, monte colombano monte bernard e monte colombano monte corno; un circoscritto gruppo di block stream di piccole dimensioni è stato inoltre individuato a est del monte bellacomba, sul versante sinistro del t. stura di viù. i block stream si concentrano nei settori centrali del mpl costituiti principalmente da peridotiti, mentre nei settori periferici del massiccio, caratterizzati da affioramenti di serpentiniti e di peridotiti con diverso grado di serpentinizzazione, i l numero e le dimensioni dei block stream decrescono sensibilmente (fig. 2). lo sviluppo delle coltri detritiche a grossi blocchi sembra invece precluso dalla presenza delle fasce di deformazione tettonica che attraversano o bordano i l mpl, come accade nel settore compreso tra il colle lunella e il colle portia: ciò è imputabile sia all’elevato grado di fratturazione del substrato che accompagna le zone di faglia (cfr. fig. 2) e che non consente la formazione di grossi blocchi, sia alla presenza lungo questi settori di estese fasce serpentinitiche che impediscono lo sviluppo dei fenomeni di alterazione. la superficie dei singoli block stream è compresa tra 0,3 e 91,6 ha, a fronte di un valore medio di 9,3 ha (tab. i): i fenomeni arealmente più estesi derivano i l più delle volte dalla coalescenza di più l ingue 9 fig. 3 panoramica dei block stream n. 65, 66 e 69 localizzati sul versante sud-orientale del monte druina. in primo piano sono visibili il fondovalle del t. ceronda e l'abitato di varisella. view of the block streams n. 65, 66 and 69 along the south-eastern slope of the mount druina. in the foreground are visible the valley floor of the ceronda stream and the village of varisella. fig. 4 panoramica dei block stream n. 95-99 localizzati sul versante sud-occidentale della dorsale spartiacque ceronda-casternone. panoramic view of the block streams n. 95-99 along the south-western slope of the cerondacasternone drainage divide. i block stream del massiccio peridotitico di lanzo detritiche. la lunghezza varia da un minimo di 88 m a un massimo di circa 2,2 km (2202 m per il block stream n. 73 e 2227 m per il block stream n. 72; fig. 2), con un valore medio di circa 700 m. la pendenza media della superficie dei block stream è compresa tra 13,3° e 44,8°, quest'ultimo valore prossimo all’angolo di attrito interno del deposito detritico; il 76% dei block stream ha tuttavia una pendenza media compresa tra 23° e 32°. nell'ambito dei singoli block stream i settori a maggiore acclività coincidono con le aree altimetricamente più elevate delle coltri detritiche, mentre in prossimità delle fronti la pendenza diminuisce gradualmente fino a raggiungere valori di 2÷3°. i dati relativi all’esposizione indicano che il 46,75% della superficie complessiva occupata dai block stream si colloca su versanti rivolti a nw, a nnw e a ese (fig. 6). anche l'analisi della distribuzione altimetrica sembra evidenziare un sia pur minimo controllo dell’esposizione sulle quote raggiunte dai block stream: le fronti delle lingue detritiche esposte verso i quadranti settentrionali e orientali si posizionano infatti a quote relativamente più basse (in media di circa 90 m) rispetto agli altri settori del mpl (fig. 7). 10 fig. 5 schema geomorfologico dei block stream localizzati nel settore settentrionale del massiccio peridotitico di lanzo, nei pressi di germagnano. 1) substrato indifferenziato (peridotiti, peridotiti serpentinizzate e serpentiniti); 2) depositi fluvial i del t. stura di lanzo; 3) depositi detrit ici non vegetati; 4) depositi detritici colonizzati da vegetazione; 5) dorsali longitudinali; 6) lobi; 7) depressioni longitudinali; 8) fascia detrit ica di pirosseniti; 9) affioramento di pirosseniti; 10) sorgenti; 11) numero identificativo dei block stream. geomorphologic sketchmap of the block streams on northern part of the lanzo peridotitic massif near germagnano. 1) undifferentiated bedrock (peridotites, serpentinitic peridotites and serpentintes); 2) fluvial deposits of the stura di lanzo stream; 3) bare blocky deposits; 4) vegetated blocky deposits; 5) longitudinal ridges; 6) lobes; 7) longitudinal furrows; 8) pyroxenitic band; 9) pyroxenite outcrop; 10) springs; 11) identification code of the block streams. fig. 6 esposizione areale dei block stream. areal exposure of the block streams. g. fioraso & g. spagnolo meccanismi di alimentazione della frazione detritica: clasti di minori dimensioni e con un maggior grado di arrotondamento derivano presumibilmente da fenomeni di alterazione profonda sviluppati all'interno del substrato; una maggiore angolosità caratterizza invece i blocchi generati da fenomeni superficiali di allentamento e rilascio gravitativo degli affioramenti peridotitici. le caratteristiche morfodimensionali dei clasti e la presenza di una gradazione inversa all'interno della sequenza detritica rappresentano un chiaro indice dello sviluppo di meccanismi di vertical sorting presumibilmente causati dal lento movimento verso valle dei block stream: questi fenomeni giustificherebbero, inoltre, la frequente presenza di blocchi isolati di grandi dimensioni (15÷20 m3) "galleggianti" sulla superficie delle lingue detritiche (fig. 16). la coltre detritica poggia, tramite un contatto netto ad andamento irregolare, su un complesso di sedimenti con tessitura matrix-supported (fig. 9 e 10) in cui la matrice, pari al 50÷80% del deposito, è costituita da sabbia, silt e argilla in proporzioni estremamente variabili; analisi granulometriche effettuate su campioni di sedimenti prelevati in corrispondenza di 4 block stream localizzati in diversi settori del mpl evidenziano percentuali della frazione siltoso-argillosa comprese tra il 29% ed il 55%, con percentuali di silt ed argilla che oscillano rispettivamente tra il 21÷34% e il 7÷22% (fig. 11 5. stratigrafia e idrogeologia dei block stream la porzione superficiale dei block stream è costituita da un complesso detritico a grossi blocchi del tutto privo di matrice e con tessitura di tipo openwork (fig. 8); la sua potenza è piuttosto esigua ed è compresa tra 1 e 7 m. i blocchi hanno dimensioni medie comprese tra 0,5 e 1,5 m, ma talvolta possono raggiungere lunghezze di 3÷4 m e un volume di 20÷25 m3 (fig. 16). la litologia dei blocchi è piuttosto monotona, essendo rappresentata da peridotiti e/o peridotiti debolmente serpentinizzate (circa 90÷95%) e, subordinatamente, da serpentiniti (5÷10%) e minime percentuali di rocce gabbriche e basaltiche (<1%): la composizione dei clasti rispecchia piuttosto fedelmente l'omogeneità litologica che caratterizza il mpl e indica inequivocabilmente una provenienza esclusivamente locale del materiale detritico. i blocchi, da angolosi a subangolosi, sono di forma cubica, prismatica e cuneiforme, geometrie che riflettono l'orientazione e la spaziatura reciproca dei sistemi di fratture e delle discontinuità mineralogiche presenti nel substrato; solo in corrispondenza dei settori periferici del mpl, caratterizzati da una più significativa percentuale di affioramenti di natura serpentinitica, i clasti possono assumere una forma tabulare o a losanga. in tutti i blocchi è presente un cortex di alterazione di 5÷15 mm di spessore, in corrispondenza del quale l’olivina è trasformata in un feltro giallo arancio dal quale spiccano inalterati i cristalli di ortopirosseno e di spinello. internamente i blocchi si presentano invece sostanzialmente inalterati, tanto da poter essere utilizzati come materiale lapideo da costruzione. i blocchi più superficiali del complesso detritico sono rivestiti da una patina di ossidazione che conferisce ai block stream una colorazione variabile da nerastra a rossoviolacea; inoltre le superfici dei blocchi esposte al dilavamento meteorico hanno un aspetto particolarmente scabro dovuto alla progressiva rimozione dei minerali di alterazione argillosi. verso la base del complesso detritico il diametro dei blocchi e conseguentemente il volume dei vuoti decrescono dando luogo a una struttura di tipo coarsening-upward (fig. 9 e 10). inoltre, contrariamente a quanto osservato in superficie, i blocchi sono contraddistinti da un maggior grado di arrotondamento e da un aspetto meno butterato. la diversa morfologia dei blocchi osservabile in superficie e in profondità può essere attribuita a distinti fig. 7 distribuzione altimetrica ed esposizione dei block stream del massiccio peridotitico di lanzo. i pallini neri rappresentano la fronte delle singole lingue detritiche. exposure and altimetric distribution of the block streams of the lanzo peridotitic massif. dots correspond to block stream toes. i block stream del massiccio peridotitico di lanzo 11). la frazione detritica inglobata nella matrice è costituita da clasti, da angolosi a subarrotondati, di dimensioni comprese tra 5 e 25 cm e, raramente, da blocchi di dimensioni inferiori al metro. all'interno della matrice sono localmente presenti lenti e livelli detritici di spessore decimetrico con tessitura di tipo clast-supported. nel suo insieme la matrice è caratterizzata da un aspetto massivo eterogeneo; in alcuni casi al suo interno sono state osservate zone di taglio orientate parallelamente alla superficie dei block stream, in corrispondenza delle quali è percepibile una riorientazione dei clasti e la presenza di strie meccaniche che registrano movimenti distensivi di natura gravitativa. piuttosto scarse risultano le informazioni relative allo spessore del complesso inferiore: gli unici dati disponibili sono quelli forniti da alcuni sondaggi effettuati in corrispondenza del block stream n. 11, localizzato sul versante destro del t. richiaglio, che hanno consentito di accertare per l'intervallo sabbioso-siltosoargilloso una potenza compresa tra 0,5 e 22 m; lo spessore massimo complessivo della coltre detritica e della matrice basale è invece risultato pari a 25,5 m (fig. 8). per gli altri block stream del mpl non sono invece disponibili dati di sottosuolo; tuttavia, pur in presenza di 12 sensibili variazioni di spessore anche nell’ambito di uno stesso block stream, considerando la morfologia delle lingue detritiche e l'andamento locale dei versanti, è ipotizzabile che lo spessore complessivo di questi fenomeni possa localmente raggiungere valori di 30÷35 m e, in taluni casi, anche più elevati. i block stream generalmente poggiano direttamente sul substrato roccioso, le cui asperità e irregolarità sono mascherate dagli ingenti spessori dei sedimenti. tuttavia, sul versante orientale del mpl e in alcuni settori interni della valle di viù, le fronti di alcune lingue detritiche si giustappongono a depositi grossolani fortemente alterati e cementati: questi depositi, interpretabili come antichi apparati di conoide alimentati essenzialmente da processi di tipo torrentizio e di debris flow, risultano in rapporto di eteropia nei confronti dei termini più recenti della successione "villafranchiana" conservata ai margini del massiccio di lanzo (balestro et al., 2009) (fig. 12). grazie al forte contrasto di permeabilità che contraddistingue il complesso detritico superiore dal complesso inferiore, all'interno dei block stream è presente un'intensa circolazione idrica concentrata all'interfaccia tra i due termini della successione. il deflusso subdetritico dà origine sulla fronte dei block stream a cospicue emergenze sorgentizie che alimentano il reticolato idrografico di superficie; altre sorgenti sono invece localizzate all'interno dei block stream nei punti in cui la superficie topografica interseca l'interfaccia tra il complesso detritico e il complesso inferiore. in taluni casi è inoltre possibile osservare direttamente il deflusso subdetritico in corrispondenza di trincee e brevi gallerie realizzate allo scopo di captare le acque per uso irriguo e che attraversano, talvolta fino a 4÷5 m di profondità, l'intero complesso detritico. sebbene il deflusso non sia direttamente visibile in tutti i block stream, frequentemente è possibile intuirne la presenza per l'intenso rumore ed il gorgoglio percepibili percorrendo il manto detritico. le portate, variabili in funzione dell'estensione del bacino di alimentazione, sono normalmente comprese tra 2÷5 l/s e 15÷25 l/s per i block stream di maggiori dimensioni. i deflussi oscillano stagionalmente in funzione dello scioglimento della copertura nevosa e dell’andamento delle precipitazioni: a seguito di eventi piovosi particolarmente intensi sulla fronte di alcuni block stream sono state stimate portate di alcune centinaia di litri al secondo. in concomitanza con i periodi di siccità prolungata, nei block stream arealmente poco estesi i deflussi fig. 8 stratigrafie di alcuni sondaggi effettuati nell’ambito del block stream n. 11, localizzato sul versante destro della valle del t. richiaglio. a) complesso detritico superiore con tessitura open-work; b) successione siltoso-argillosa e siltoso-sabbiosa del complesso inferiore con tessitura matrix supported; c) substrato roccioso. in corsivo sono indicate le percentuali di matrice presenti nel sedimento. logs of borehole realized within block stream n. 11 along the western slope of the richiaglio catchment. a) blocky mantle with open-work texture; b) silty-clayey and silty-sandy succession with matrix-supported texture; c) bedrock. matrix percentages are expressed in italic. g. fioraso & g. spagnolo tendono gradualmente a diminuire fino ad esaurirsi; negli altri casi, pur in presenza di scarse precipitazioni, è invece sempre rilevabile un sia pur minimo deflusso. questo dato conferma, indirettamente, che al di sotto del complesso detritico sono presenti notevoli volumi di sedimenti siltoso-sabbioso-argillosi in grado di immagazzinare ingenti quantitativi di acqua che vengono gradualmente rilasciati nei periodi caratterizzati da scarse precipitazioni. il drenaggio subdetritico si concentra lungo depressioni modellate alla sommità del complesso inferiore; in molti casi queste direttrici di deflusso sembrano ricalcare per lunghi tratti l'andamento delle depressioni longitudinali presenti sulla superficie dei block stream. il deflusso subdetritico è accompagnano da diffusi fenomeni di piping (smith & smith, 1945), i cui effetti sono chiaramente osservabili soprattutto in occasione di eventi piovosi particolarmente intensi: il repentino incremento delle portate determina infatti da un lato un sensibile aumento della torbidità dell’acqua causata dal trasporto in sospensione della frazione siltoso-argillosa, dall'altro la mobilizzazione della frazione sabbiosa come carico di fondo. il trasporto delle particelle più grossolane è tuttavia in parte ostacolato dalla presenza dei blocchi che svolgono un’azione protettiva nei confronti dei fenomeni di erosione; inoltre la rimozione della matrice presente alla base del complesso detritico è parzialmente compensata dagli apporti di sedimenti provenienti dal dilavamento dei tratti di versante che sovrastano i block stream. 6. espressione morfologica complessivamente la superficie dei block stream è contraddistinta da una distribuzione uniforme ed estremamente regolare delle coltri detritiche, al più caratterizzata dalla presenza in senso longitudinale di ondulazioni di ampiezza decametrica-ettometrica che conferiscono una caratteristica morfologia "a onde" al manto detritico (capello, 1963). nelle porzioni medioinferiori dei block stream, contraddistinte da un maggior grado evolutivo, la copertura di blocchi può tuttavia dare luogo a forme piuttosto complesse di non facile interpretazione. le più frequenti sono rappresentate da dorsali longitudinali (fig. 5), allungate per decine o centinaia di metri parallelamente all’asse dei block stream e con una larghezza compresa tra gli 8 e i 15 m. le dorsali sono frequentemente localizzate in prossimità dei margini laterali dei block stream, rispetto ai quali risultano 13 fig. 9 taglio artificiale di circa 3 m di altezza realizzato in corrispondenza del margine nord-orientale del block stream n. 80 (bacino del t. ceronda). si nota chiaramente il complesso detritico superiore, con distribuzione dei clasti di tipo coarsening-upward, poggiante sul complesso inferiore costituito da diamicton a matrice siltoso-argillosa e siltoso-sabbiosa. road cut (up to 3 m high) along the north-eastern margin of the block stream n. 80 (ceronda catchment). the blocky mantle with coarsening-upward texture rest on a basal diamict made up of silty-clayey and silty-sandy matrix. fig. 10 taglio artificiale di circa 2 m di altezza realizzato in corrispondenza del block stream n. 8b sul versante occidentale del monte colombano. a) complesso detritico superiore con tessitura open-work; b) complesso inferiore con matrice siltosoargillosa; c) superficie di scivolamento; d) substrato roccioso. road cut (2 m high) through the block stream n. 8b along the western slope of the mount colombano. a) blocky mantle with open-work texture; b) silty-clayey basal matrix; c) sliding surface; d) bedrock. i block stream del massiccio peridotitico di lanzo 14 fig. 11 curve granulometriche cumulative relative a campioni di matrice prelevati in corrispondenza dei block stream n. 8b, 80, 142 e 147. cumulative curves representing the particle size distribution of basal diamict sampled on block streams n. 8b, 80, 142 and 147. fig. 12 schema dei rapporti stratigrafici tra i block stream e la successione pliocenico-pleistocenica affiorante sul versante orientale del massiccio peridotitico di lanzo (non in scala). stratigraphic relationship between block stream deposits and the pliocenic-pleistocenic succession outcropping along the eastern slopes of the lanzo peridotitic massif (not in scale). g. fioraso & g. spagnolo sopraelevate di 6÷8 m: per tale motivo le lingue detritiche assumono talvolta un profilo trasversale marcatamente concavo. le dorsali possono ricorrere singolarmente o in varia combinazione e in quest'ultimo caso risultano il più delle volte strettamente affiancate con un andamento subparallelo. simili nell’aspetto alle dorsali che caratterizzano i rock glacier (wahrhaftig & cox, 1959), le dorsali longitudinali rilevabili sulla superficie dei block stream non presentano tuttavia la continuità e l’andamento arcuato delle rughe di compressione tipiche di questi fenomeni periglaciali. alle dorsali si accompagnano spesso depressioni longitudinali (fig. 13) (lovejoy, 1972), profonde fino a un massimo di 4÷6 m, larghe da 10 a 15 m ed allungate per decine o centinaia di metri parallelamente all'asse dei block stream . possono costituire avvallamenti interposti tra due dorsali longitudinali oppure sono localizzate nella parte assiale delle lingue detritiche: nel primo caso danno luogo a un profilo trasversale a "u" e sono presumibilmente legate a movimenti differenziali sviluppati all'interno della copertura detritica; nel secondo caso il profilo trasversale a "v" degli avvallamenti potrebbe essere causato dal richiamo verso il basso della coltre detritica indotto dalla rimozione della sottostante matrice da parte del deflusso subdetritico (sumner, 2004). sulla superficie del complesso detritico sono spesso presenti lobi (potter & moss, 1968; grab, 1999) (fig. 5), larghi decine di metri e rilevati fino a 8 m rispetto alla circostante superficie dei block stream. queste morfologie possono assumere l'aspetto di blandi rigonfiamenti della coltre detritica oppure configurarsi come vere e proprie lingue con margini frontali e laterali netti e ben marcati. le fronti dei lobi sono generalmente molto acclivi (35÷45°) con blocchi spesso in condizioni di equilibrio precario. talvolta, nel settore frontale di alcuni lobi sono presenti rughe trasversali estese lateralmente per alcune decine di metri e ampie fino a 8÷10 m; le rughe occorrono singolarmente ma possono anche presentarsi in piccoli gruppi con un andamento subparallelo, separate da depressioni di 0,5÷1 m di profondità. sebbene la loro genesi non sia del tutto chiara, queste rughe potrebbero rappresentare l'effetto di fenomeni di collasso sviluppati nei settori frontali e più acclivi dei lobi o, più verosimilmente, potrebbero costituire il prodotto di movimenti compressivi localizzati nei settori frontali dei lobi detritici con meccanismi analoghi a quelli che danno origine alle rughe frontali dei rock flow. la presenza di dorsali longitudinali e lobi sulla superficie dei block stream è spesso accompagnata da repentine variazioni dimensionali dei blocchi (fig. 14) e, più raramente, da variazioni nella composizione litologica degli stessi. questa particolarità evidenzia la presenza di aree di alimentazione del complesso detritico distinte in funzione del grado di fratturazione e della natura del substrato; inoltre evidenzia la presenza, nel tempo e nello spazio, di movimenti differenziali interni ai block stream in grado di causare, a valle dei punti di confluenza, la giustappozione dei diversi flussi detritici. caratteristica comune a molti block stream è la presenza di depressioni chiuse di 4÷8 m di diametro e 1÷1,5 m di profondità e, più raramente, di depressioni semiaperte verso valle di diametro compreso tra 25 e 40 m e con una profondità di 2÷4 m; nelle depressioni di maggiori dimensioni la zona centrale è spesso inerbita ed il più delle volte ospita delle emergenze sorgentizie (fig. 15). le depressioni di piccolo diametro possono essere ricondotte a localizzati fenomeni di subsidenza causati dall'assestamento del complesso detritico a seguito della rimozione della matrice da parte del deflusso subdetritico (lovejoy, 1972; mills, 1988); lo sviluppo delle depressioni di diametro maggiore è invece più probabilmente causato da movimenti differenziali sviluppati entro le coltri detritiche. a completamento del quadro delle morfologie di superficie rilevate è da segnalare la presenza, in corrispondenza del settore frontale di alcuni block stream particolarmente estesi e più prossimi alle aree di fondovalle, di imponenti scarpate ad elevata acclività (40÷45°) alte fino a 15 m e con una tipica configurazione a "ferro di cavallo"; alla base delle scarpate sono sempre presenti emergenze sorgentizie di discreta portata che alimentano perennemente il reticolato idrografico di superficie. le scarpate costituiscono l'espressione della forte tendenza all'approfondimento erosivo che attualmente caratterizza tutti i corsi d'acqua che drenano il mpl: nel caso di precipitazioni piovose particolarmente intense gli ingenti deflussi subdetritici possono infatti intaccare la fronte dei block stream, dando luogo a repentini fenomeni di collasso e di erosione regressiva 15 fig. 13 depressione longitudinale di 18÷20 m di larghezza e 5 m di profondità localizzata nel settore centrale del block stream n. 60, 1,5 km a ene del monte druina. longitudinal depression (18÷20 m wide and 5 m deep) in the central sector of the block stream n. 60, 1.5 km ene of mount druina. i block stream del massiccio peridotitico di lanzo a spese del manto detritico e all'innesco di debris flow con conseguente sviluppo di scarpate e nicchie di distacco. 7. attività dei block stream gran parte delle coltri detritiche mostrano nell'insieme caratteristiche che testimoniano attualmente una relativa stabilità morfologica dei block stream: fra questi l'uniformità del grado di alterazione dei blocchi peridotitici, la regolare distribuzione della copertura lichenica e l'assenza di anomalie nello sviluppo della vegetazione arborea sporadicamente presente sulla superficie di alcuni block stream. non mancano tuttavia elementi che da un lato attestano la presenza di significative componenti di flusso che hanno interessato nel passato le coltri detritiche, dall'altro testimoniano l'attuale presenza di localizzati movimenti verso valle, elementi che risultano particolarmente significativi per definire un modello evolutivo affidabile per queste singolari fenomenologie di versante. alcune indicazioni emergono in primo luogo dall'analisi dei rapporti geometrici delle lingue detritiche con i limiti stratigrafici e tettonici del mpl. le fronti di alcuni block stream intersecano e attraversano per lunghi tratti aree caratterizzate da una diversa composizione litologica del substrato: l'esempio più eclatante è fornito dal block stream n. 8b (cfr. fig. 2), la cui fronte sopravanza di ben 680 m la zona di taglio colle lunella colle portia che separa le peridotit i del monte colombano, a est, da una scaglia di serpentiniti, metabasiti e calcescisti, a ovest. situazioni del tutto simil i sono state descritte da cowan & mansfield (1970) per quantificare l'entità del movimento di alcuni rock flow localizzati nella coast ranges in california, anch'essi sviluppati su un substrato dunitico-peridotitico parzialmente serpentinizzato. ulteriori indicazioni sulla mobilità pregressa delle coltri detritiche derivano dall'analisi della distribuzione delle diverse facies peridotitiche. sulla superficie di alcuni block stream (es. n. 31; fig. 2) sono infatti presenti fasce detritiche di ampiezza decametrica e lunghezza ettometrica con tonalità di colore più chiare, localizzate a valle di affioramenti di peridotiti serpentinizzate o di serpentiniti. in corrispondenza del block stream n. 43 (fig. 5) è stata invece individuata una fascia di blocchi pirossenitici distribuiti lungo il contatto tra le due lingue detritiche, per il resto costituite da blocchi di lherzoliti: la fascia, larga 4÷6 m ed estesa verso valle per circa un centinaio di metri, trae origine da un affioramento localizzato poche decine di metri a monte del punto di confluenza delle due colate. in entrambi i casi descritti le fasce corrispondono ai punti 16 fig. 14 block stream n. 60 sul versante nord-orientale del monte druina. margine laterale sinistro di un lobo a grossi blocchi di peridotiti (a) poggiante lateralmente su una coltre detritica costituita da clasti di minori dimensioni (b). block stream n. 60 along the north-eastern slope of the mount druina. left lateral margin of a lobe made up of large peridotitic blocks (a) resting on a smaller size blocky mantle (b). fig. 15 vista verso valle di un'ampia depressione chiusa di 10÷12 m di diametro, parzialmente rivestita da coltre erbosa, localizzata sulla superficie del block stream n. 8b (versante occidentale del monte colombano). downvalley view of a large closed depression (10÷12 m in diameter) clothed on its bottom with continuous turf, localized within block stream n. 8b (western slope of the mount colombano). g. fioraso & g. spagnolo di contatto di materiale detritico di diversa provenienza e composizione, assumendo pertanto un ruolo analogo a quello svolto dalle morene mediane sviluppate in ambiente glaciale. per i block stream del mpl solo raramente sono stati rilevati chiari fenomeni di embricazione o di isorientazione dei blocchi, frequentemente descritti da molti autori (potter & moss, 1968; harris et al., 1998) quale evidenza di movimenti delle coltri detritiche: la morfologia prevalentemente prismatica e isodiametrica dei blocchi peridotitici non ha infatti consentito lo sviluppo di simili strutture che possono essere più facilmente rilevate in presenza di detrito sviluppato a spese di substrato serpentinitico (firpo et al., 2006). in alcuni casi (es. block stream n. 42; fig. 2) sono stati tuttavia osservati rilevanti fenomeni di verticalizzazione dei blocchi di forma allungata e, nel caso di elementi lapidei a spiccata morfologia tabulare, accenni di strutture embricate. anche la frequente presenza di blocchi isolati di grande diametro e volume "galleggianti" sulla superficie dei block stream (fig. 16), unitamente alle strutture gradate rilevate all'interno delle coltri superficiali, testimoniano la presenza di fenomeni di vagliatura (sieve selection) della frazione detritica per effetto del suo lento movimento verso valle. quest'ultimo è inoltre confermato dai frequenti casi di autoframmentazione dei blocchi rilevati sulla superficie dei block stream che si manifestano con la rottura, la disgiunzione e la disarticolazione dei blocchi peridotitici: il distacco avviene solitamente lungo fratture o discontinuità mineralogiche primarie (ad esempio lungo il contatto tra livelli pirossenitici e roccia incassante) che talvolta si presentano relativamente fresche e non ancora intaccate dall'alterazione superficiale. indicazioni sull'entità dei movimenti sul lungo periodo di alcuni block stream sono emerse dall'analisi dei rapporti con la successione fluviale quaternaria presente lungo il margine settentrionale del mpl: sui versanti sovrastanti l'alveo del t. stura di viù sono infatti conservati numerosi lembi di depositi fluviali terrazzati riferibi l i al le diverse fasi di approfondimento erosivo di questo corso d'acqua. a tal fine è stato realizzato un profi lo morfostratigrafico tracciato lungo l'alveo del t. stura tra gli abitati di viù e lanzo, che ha consentito di individuare 6 unità, sospese fino a 150÷160 m sull'alveo del t. stura e di età compresa tra il pleistocene medio (unità di s. giovanni e di castagnole) e l'olocene (unità di germagnano) (fig. 17). il profilo evidenzia chiaramente come le unità siano intersecate in più punti e a quote diverse da almeno 11 block stream le cui fronti giungono in taluni casi a lambire l'alveo del t. stura (n. 43, 46, 150 e 153), risultando conseguentemente “incastrati” nelle fasce di modellamento fluviale: ciò conferma la presenza di movimenti sviluppati a spese delle coltri detritiche quanto meno attivi fino a buona parte dell'olocene. indicazioni sull'attuale stato di attività dei block stream derivano dallo studio del numero e del diametro medio dei talli lichenici che, in corrispondenza di alcune dorsali longitudinali e di alcuni lobi caratterizzati da una maggiore instabilità dei blocchi, risultano di gran lunga inferiori rispetto a quelli rilevati negli altri settori, più stabili, delle coltri detritiche. particolare rilevanza assumono i cedimenti verticali di varia entità (0,5÷5 m) osservati nel tracciato e nella lastricatura dei sentieri che attraversano in più punti e a quote diverse i block stream. in taluni casi, inoltre, i tratti lastricati si interrompono in corrispondenza di fasce detritiche caratterizzate da un minor grado di alterazione superficiale, da una maggiore mobilità dei blocchi e da una copertura lichenica spesso assente o poco sviluppata, elementi chiaramente indicativi di una mobilizzazione piuttosto recente del detrito. infine, episodi di rapido sopravanzamento del margine di alcuni block stream su aree prative adibite a pascolo sono stati in passato segnalati nel settore di maddalene (capello, 1963). 8. meccanismi genetici ed evolutivi la genesi dei block stream è stata attribuita da numerosi autori (joyce, 1950; psilovikos & van houten, 1982; whittecar & ryter, 1992; harris et al., 1998; boelhouwers, 1999; summer, 2004) a fenomeni di geliflussione sviluppati in ambienti stagionalmente o permanentemente gelati; in alcuni casi, tuttavia, i block stream sono stati interpretati come lag deposit (boelhouwers et al., 2002), come prodotti dell’evoluzione di debris flow (lovejoy, 1972) o come effetto combi17 fig. 16 blocco peridotitico di circa 3,5 m di larghezza "galleggiante" sulla superficie della coltre detritica del block stream n. 72, lungo il fianco occidentale del monte colombano. peridotite block (3.5 m wide at the base) “floating” above free-matrix detrital mantle in the block stream n. 72, along the eastern slope of the mount colombano. i block stream del massiccio peridotitico di lanzo 18 fi g. 1 7 p ro fil o m or fo st ra tig ra fic o re al iz za to lu ng o l'a ss e va lli vo d el t . s tu ra t ra g li ab ita ti d i v iù e l an zo c he e vi d en zi a il ra p p or to d i i nt er se zi on e d ei b lo ck s tr ea m co n le u ni tà d i m od el la m en to flu vi al e. m or p ho st ra tig ra p hi c p ro fil e tr ac ed a lo ng t he s tu ra s tr ea m b et w ee n v iù a nd l an zo , s ho w in g th e ov er la p p in g re la tio ns hi p s b et w ee n b lo ck s tr ea m s an d fl uv ia l u ni ts . g. fioraso & g. spagnolo nato di più meccanismi genetici (mills, 1988; grab, 1999). scarsa influenza nell'evoluzione di questi fenomeni sembra invece rivestire la natura mineralogicopetrografica del substrato da cui traggono origine le coltri detritiche, rappresentato da un ampio spettro composizionale: rocce intrusive, effusive e metamorfiti di varia composizione. per quanto riguarda il massiccio di lanzo emerge invece il forte legame tra i block stream e la presenza di un substrato di tipo peridotitico: la spiccata degradabilità di quest'ultimo costituisce senza dubbio l'elemento chiave in grado di chiarire e delineare i meccanismi genetici di questi fenomeni. i processi di alterazione hanno tuttavia agito differentemente in funzione del contesto morfologico locale di versanti: nei settori maggiormente acclivi la degradazione delle peridotiti si è sviluppata di pari passo con il dilavamento dei prodotti di alterazione ad opera del ruscellamento diffuso o con la loro rimozione da parte dei processi di colluvionamento; nelle aree topograficamente meno acclivi e meno esposte all'erosione è invece prevalso il graduale accumulo delle alteriti e la concomitante concentrazione in superficie dei blocchi provenienti dal disfacimento fisico del substrato affiorante. la prolungata reiterazione e interazione di questi processi di versante ha consentito, nel tempo, la graduale separazione della frazione detritica superficiale dalla matrice basale, fenomeno che è risultato progressivamente più marcato procedendo da monte verso le aree di fondovalle. meccanismi di dilavamento, classazione e concentrazione granulometrica dei prodotti di alterazione analoghi a quelli descritti per il mpl sono stati osservati da de chételat (1947) in corrispondenza di alcuni giacimenti di nichel ospitati nei massicci peridotitici della nuova caledonia e in un contesto climatico di tipo subtropicale. il progressivo accumulo di sedimenti lungo i versanti ha consentito l'avvio di lenti e graduali movimenti gravitativi con prevalenti meccanismi di creep (potter & moss, 1968), testimoniati dalla presenza di strutture di flusso individuate all’interno del complesso inferiore. il creep è favorito dalle elevate percentuali di argilla montmorillonitica presenti nella matrice, che possono rappresentare fino al 22% del volume del sedimento. questo minerale si caratterizza per gli elevati coefficienti di espandibilità (karaborni et al., 1996; bell, 1998; katti & katti, 2003) in grado di determinare fenomeni di rigonfiamento e contrazione in funzione del grado di idratazione della matrice. le elevate percentuali di argilla garantiscono inoltre un'elevata plasticità alla matrice consentendo in tal modo il movimento dei sedimenti e delle sovrastanti coltri detritiche anche in presenza di valori di acclività estremamente bassi (< 5°) quali quelli rilevati in alcuni block stream. in questo quadro evolutivo la coltre detritica sembra avere svolto un ruolo sostanzialmente passivo in quanto completamente priva di coesione. a seguito del lento scorrimento verso valle della matrice, il detrito soprastante ha subito unicamente una riorganizzazione interna evidenziata dalla diffusa presenza di strutture di tipo coarsening upward. oltre alla composizione mineralogica e granulometrica della matrice, altre variabili quali l'acclività dei versanti, lo spessore dei sedimenti e il grado di umidità possono di volta in volta intervenire nel controllare la velocità e l'entità della deformazione dei block stream. locali variazioni di questi parametri possono determinare una diversa risposta reologica dei sedimenti allo stress gravitativo e conseguentemente originare componenti di movimento differenziali all'interno dei block stream: viene in tal modo giustificata la presenza di lobi e dorsali longitudinali concentrati soprattutto nei settori distali delle lingue detritiche ove maggiori risultano gli spessori della matrice. l'entità della deformazione per creep può in taluni casi generare vere e proprie superfici di rottura della matrice, come nel caso del block stream n. 60, localizzato sul versante nord-occidentale del monte druina: alcuni metri al di sotto dell'interfaccia detrito-matrice sono stati rilevati piani di taglio di estensione da metrica a decametrica orientati parallelamente alla superficie topografica, che denotano un parziale scollamento dei termini più superficiali delle lingue detritiche. fenomeni analoghi sono stati osservati in corrispondenza di alcuni block stream (n. 8a, 8b e 9; fig. 2) localizzati sul versante occidentale del monte colombano: in questi casi, tuttavia, la superficie di scivolamento è localizzata al contatto con il substrato roccioso, ove è presente un livello di 3÷8 cm di spessore di colore grigio argenteo costituito da un impasto milonitico (sviluppato a spese di alcune scaglie di serpentiniti e prasiniti) che accompagna per tutto il suo sviluppo la zona di taglio di colle lunella colle portia (fig. 10); l'ampiezza della zona di taglio (valutabile in alcune decine di metri) e l'elevata plasticità della roccia di faglia, favorita anche dall'elevato grado di imbibizione, ha consentito a quest'ultima di essere spremuta dal peso del flusso detritico e di essere utilizzata come lubrificante. ciò giustifica l'anomala conformazione assunta dal block stream n. 8b che in alcuni punti non supera i 10÷12 m di larghezza e i 3÷5 m di spessore a fronte di una lunghezza di oltre 1300 m. anche l'abbondante circolazione idrica subdetritica assume un ruolo non trascurabile nell’evoluzione dei block stream: la continua azione di apporto e/o rimozione della frazione fine causa un graduale e costante rimodellamento dell'interfaccia tra il complesso detritico superiore e il complesso inferiore con effetti di richiamo della copertura detritica lungo le principali direttrici di deflusso e lo sviluppo in superficie di depressioni longitudinali. i dati relativi all'esposizione (fig. 7), con particolare riferimento alle quote raggiunte dalle fronti detritiche localizzate sugli opposti versanti del mpl, sembrerebbero avvalorare, a parità di altre condizioni, un'influenza di tipo climatico sull'evoluzione dei block stream. il raggiungimento di quote relativamente meno elevate (in media di circa 90 m) da parte dei block stream esposti verso i quadranti settentrionali può inquadrarsi nel differente regime termico che caratterizza i versanti del mlp, sottoposti ad un diverso grado di irraggiamento solare e conseguentemente caratterizzati da un differente tasso medio di umidità della matrice. appare invece assai improbabile un contributo diretto da parte di fenomeni periglaciali in quanto le quote raggiunte dalle lingue detritiche sono troppo basse (quanto meno alle latitudini dell’area in studio, comprese tra 45° 07’ e 45° 16’ n) per consentire lo sviluppo di significativi volumi di ghiaccio interstiziale. in tal senso le fronti dei block stream si collocano ben al di sotto (in taluni di casi di 1800 m) del limite minimo raggiunto dalle fronti dei rock glacier attivi (2679 m) e inattivi (2288 m) presenti nelle alpi graie (guglielmin & smiraglia, 1997). anche per quanto riguarda i settori altimetrica19i block stream del massiccio peridotitico di lanzo mente più elevati del mpl non sono emersi elementi morfologici, stratigrafici o tessiturali che attestino con sicurezza un contributo attuale o pregresso da parte di fenomeni periglaciali nello sviluppo dei block stream. non è tuttavia da escludere che in regimi climatici diversi dall'attuale (soprattutto in coincidenza con i picchi di raffreddamento raggiunti nel corso delle glaciazioni pleistoceniche) episodi di geliflussione possano aver localmente coinvolto le coltri detritiche, soprattutto nei settori di versante più elevati e più sfavorevolmente esposti all'irraggiamento solare. resta inoltre da valutare (con l'ausilio di opportuni strumenti di monitoraggio termometrico) il possibile sviluppo di ghiaccio per effetto dei particolari regimi termici che possono instaurarsi all’interno di estese e potenti coperture a blocchi con tessitura open-work, in grado di ridurre di 3÷7 °c (harris & pedersen, 1998; gorbunov et al., 2004) la temperatura media annua dell’aria all’interno dei block stream rispetto a quanto rilevato in superficie. la possibilità di sviluppo di significative anomalie termiche negative sembrerebbe confermata dalla presenza, anche in piena stagione estiva, di incrostazioni di ghiaccio all’interno di un accumulo a grossi blocchi localizzato a circa 1500 m di quota sulla dorsale che separa il versante destro della bassa valle d’aosta dalla val chiusella, in un contesto altimetrico, orografico e morfologico del tutto analogo a quello che caratterizza il mpl. 9. discussione e conclusioni il mpl, oltre a rappresentare uno degli elementi strutturali chiave della catena alpina occidentale, ospita un'eccezionale concentrazione di block stream che complessivamente coprono una superficie pari a circa il 10% dell'area di affioramento del massiccio. al fine di chiarire i meccanismi genetici e di delineare i rapporti con l'evoluzione pliocenico-quaternaria di questo settore dell'arco alpino è stato effettuato uno studio, esteso a tutto il mpl, che ha consentito di individuare e cartografare 157 block stream che sono stati caratterizzati dal punto di vista morfologico, stratigrafico e sedimentologico. i block stream sono costituiti da un complesso detritico superiore costituito da blocchi con tessitura open-work poggiante su un potente materasso di sedimenti sabbioso-siltoso-argillosi. la copertura detritica, oltre ad essere caratterizzata da uno spessore relativamente esiguo (non più di 5÷7 m) e da un'estrema uniformità tessiturale, dà luogo ad un insieme di elementi morfologici apparentemente simili a quelli riscontrabili in altre fenomenologie di versante (es. debris flow e rock glacier). l'elevata concentrazione di block stream presenti nel mpl costituisce senza dubbio una specificità nell'evoluzione di questo settore della catena alpina. la maggior parte dei block stream si addensa nei nuclei centrali del mpl costituiti da peridotiti non metamorfosate, mentre nei settori periferici del massiccio, caratterizzati da serpentiniti o da peridotiti variamente serpentinizzate, il numero e le dimensioni dei block stream decrescono sensibilmente. a parità di condizioni morfo-topografiche, tettoniche e climatiche, l'unico fattore in grado di giustificare nel mpl una presenza così massiccia di questi fenomeni è pertanto quello litologico: infatti, grazie all'abbondante presenza di minerali femici estremamente suscettibili alla degradazione subaerea quali l'olivina e i pirosseni, hanno potuto svilupparsi fenomeni di alterazione che, per intensità, rapidità e grado evolutivo, non trovano riscontro nelle altre unità lito-strutturali che compongono l'arco alpino occidentale. il mpl, inoltre, si colloca in un settore marginale della catena sfuggito all'azione esarativa operata dai ghiacciai pleistocenici che nelle fasi di massima avanzata hanno in alcuni casi (es. ghiacciai della dora baltea e della dora riparia) ripetutamente raggiunto gli sbocchi vallivi espandendosi verso le aree di pianura. nel massiccio di lanzo l'alterazione ha quindi potuto svilupparsi ininterrottamente per un lungo lasso di tempo, originando ingenti volumi di alteriti, presupposto fondamentale per la genesi dei block stream. il forte legame tra i block stream e il substrato peridotitico costituisce quindi l'elemento chiave in grado di giustificare non solo la massiccia presenza di questi fenomeni, ma anche di chiarirne e delinearne i meccanismi genetici. lo stretto connubio tra alterazione del substrato e genesi dei block stream impone tuttavia alcune considerazioni sull'età di questi fenomeni. l'attuale morfologia del massiccio di lanzo, nelle sue linee essenziali, non si discosta molto da quella presente nel corso del pliocene medio, età attribuita da martinetto (1994) e bertoldi & martinetto (2001) alla successione fluviolacustre "villafranchiana" conservata lungo il margine orientale del massiccio. secondo questi autori i caratteri dell'associazione paleofloristica conservata al top della successione "villafranchiana" (caratterizzata in particolare dall'abbondanza di macroresti attribuiti a glyptostrobus europaeus) sarebbero compatibili con un contesto climatico di tipo subtropicale, con valori di temperatura e precipitazioni sensibilmente più elevati rispetto a quelli registrati attualmente. le condizioni di tipo caldo-umido descritte da martinetto (1994) sono peraltro del tutto confrontabili con quelle che attualmente caratterizzano la nuova caledonia, ove sono stati osservati fenomeni di alterazione a spese di peridotiti e successioni stratigrafiche del tutto analoghe a quelle rilevate nel massiccio di lanzo (de chételat, 1947). presumibilmente è in questo contesto climatico che l'alterazione ha avuto modo di svilupparsi con maggiore efficacia. questa ipotesi è avvalorata dalla presenza di ingenti volumi di depositi torrentizi e di debris flow che costituiscono la porzione più profonda dei conoidi che bordano i rilievi sud-orientali del mpl e che mostrano chiari rapporti di interdigitazione con la successione "villafranchiana" affiorante ai piedi degli stessi rilievi (balestro et al., 2009) (fig. 12): i depositi che costituiscono i paleoconoidi, oltre ad essere caratterizzati da un elevato grado di alterazione (con indici di colore compresi tra 5yr e 10r) e di cementazione, sono spesso permeati da diffuse mineralizzazioni carbonatiche di origine pedogenetica, rappresentate da dolomite e secondariamente da magnesite (miè & natale, 1978), del tutto assenti invece nella matrice basale dei block stream. il contesto climatico favorevole allo sviluppo della pedogenesi sarebbe proseguito fino al termine del pleistocene inferiore, momento in cui si è sviluppato un rapido deterioramento climatico (ravazzi & rossignol strick, 1995; ravazzi et al., 2005), con passaggio a un periodo caratterizzato alternativamente da fasi interglaciali con clima temperato umido simile a quello attuale e da fasi glaciali sensibilmente più fredde; nel corso di 20 g. fioraso & g. spagnolo queste ultime, oltre a un netto rallentamento dei processi di alterazione, sarebbe altresì prevalsa la mobilizzazione delle coltri di alterazione da parte di processi di ruscellamento e di fenomeni di soil slip e mud-debris flow. nelle fasce di versante maggiormente acclivi i processi di dilavamento della frazione sabbioso-siltosoargillosa hanno dato avvio alla graduale separazione della frazione fine dalla componente detritica grossolana. il progressivo accumulo dei prodotti fini colluviali ha quindi consentito l'innesco di meccanismi di deformazione di tipo plastico (creeping) che hanno condotto alla progressiva strutturazione dei block stream. questi ultimi rappresentano pertanto il prodotto dell'interazione e/o del susseguirsi di fenomeni di degradazione del substrato e di processi di rielaborazione dei prodotti pedogenetici protrattisi per un considerevole lasso di tempo, presumibilmente già a partire dalle fasi terminali del pleistocene inferiore. lo sviluppo delle coltri detritiche, per quanto frutto di processi fisici svoltisi in un ampio intervallo temporale, avrebbe tuttavia conosciuto fasi di maggiore o minore dinamicità in risposta alle diverse fasi climatiche attraversate (es. periodi glaciali e interglaciali). anche i tassi di movimento dei block stream sono stati sicuramente influenzati dall'andamento dei parametri climatici (temperatura media ed entità delle precipitazioni) che hanno agito con un duplice effetto: controllando le caratteristiche geotecniche dei sedimenti e incrementando ulteriormente la degradazione del substrato peridotitico. i numerosi indizi di movimento in atto riconosciuti su alcuni block stream confermerebbero che questi fenomeni sono tuttora in lenta ma graduale evoluzione. in assenza di misurazioni dirette effettuate sui singoli blocchi non è al momento possibile valutare la velocità di traslazione delle coltri detritiche: tuttavia, in base ai rapporti con le unità di modellamento fluviale presenti nella bassa valle di lanzo (fig. 16) e alle dislocazioni rilevate su alcuni manufatti antropici, i tassi di movimento delle fronti di alcuni block stream possono essere stimate in alcuni millimetri all'anno. al fine di quantificare l'entità dei movimenti è prevista la realizzazione di un sistema di monitoraggio integrato (da effettuarsi con tecniche gps e di laser scannering) in grado di verificare sul lungo periodo lo stato di attività di alcuni block stream, opportunamente scelti in base a condizioni di esposizione, morfologia ed evidenze di attività recente: ciò consentirà di mappare la distribuzione dei movimenti all'interno delle coltri detritiche e soprattutto di verificare la correlazione dei movimenti con l'andamento dei paramentri climatici locali. ringraziamenti si ringraziano f. carraro e m. firpo per la rilettura critica del manoscritto. ricerca finanziata dal cnr istituto di geoscienze e georisorse, unità operativa di torino nell'ambito del progetto carg. bibliografia balestro g., cadoppi p., piccardo g.b., polino r., spagnolo g., tallone s., fioraso g., lucchesi s. & forno m.g. (2009) note illustrative della carta geologica d'italia alla scala 1:50.000, foglio 155 torino ovest apat. servizio geologico d'italia, 160 pp. bell f.g. (1998) environmental geology. principles and practice blackwell science, 594 pp. bertoldi r. & martinetto e. (2001) key-site 7: the fossil forest of stura di lanzo. in: e. martinetto (ed.), pliocene plants, environment and climate of northwestern italy flora tertiaria mediterranea, 5 (4), 65-68. biancotti a., bellardone g., bovo s., cagnazzi b., giacomelli l. & marchisio c. (1998) distribuzione regionale di piogge e temperature regione piemonte, direzione dei servizi tecnici di prevenzione, settore meteoidrografico e reti di monitoraggio. università degli studi di torino, dipartimento di scienze della terra, 80 pp. bodinier j.l., menzies m.a. & thirlwall m.f. (1991) continental to oceanic mantle transition: ree and sr-nd isotopic geochemistry of the lanzo lherzolite massif journal of petrology (special lherzolite issue), 191-210. boelhouwers j.c. (1999) relict periglacial slope deposits in the hex river mountains, south africa: observations and palaeoenvironmental implications geomorphology, 30, 245-258. boelhouwers j.c., holness s., meiklejohn i. & summer p. (2002) observations on a blockstream in the vicinity of sani pass, lesotho highlands, southern africa permafrost and periglacial processes, 13, 251-257. boudier f. (1976) le massif lherzolitique de lanzo (alpes piémontaises). etude structurale et pétrologique thèse de doctorat d’état, university of nantes, 175 pp. boudier f. (1978) structure and petrology of the lanzo peridotite massif (piedmont alps) geol. soc. am. bull., 89, 1574-1591. boudier f. & nicolas a. (1972) fusion partielle gabbroïque dans la lherzolite de lanzo (alpes piémontaises) schweiz. min. petrogr. mitt., 52, 39-56. capello c.f. (1963) le morfologie crionivali (periglacial i ) nelle alpi graie meridionali ital iane pubblicazioni dell'istituto di geografia alpina, 3 (1), 124 pp. carraro f., fioraso g., lucchesi s. & giardino m. (2005) l'amphithéâtre morainique de rivoliavigliana. in: p. deline, m. giardino & g. nicoud (eds.), le quaternaire del vallees alpines cahiers de géographie, n. 3, 153-166. conti s. (1940) la nivazione e la morfologia periglaciale nell'appennino ligure occidentale (gruppo di voltri) boll. soc. geol. it., 59, 69-94. cowan d.s. & mansfield c.f. (1970) serpentinite flows on joaquim ridge, southern coast ranges, california geol. soc. am. bull., 81, 2615-2628. dal piaz g.v., castellarin a., boccaletti m., agip mineraria & sartori r. (coord.) (1990) structural model of italy. sheet n. 1 consiglio nazionale delle ricerche. de chetelat e. (1947) la genèse et l'évolution des gisements de nickel de la nouvelle-calédonie. bull. soc. géol. fr., (5), 17, 105-160. debelmas j., gidon m., bellière j., von raumer j., rosset j., charollais j., barféty j.c., lemoine m., caron j.m., ellemberger f., caby r., elter p., dal piaz g.b., nicolas a., monjuvent g. & carra21i block stream del massiccio peridotitico di lanzo ro f. (1980) carte géologique de la france a 1/250.000. feuil le annecy bureau de recherches géologiques et minières. elter f.m., piccardo g.b., polino r., zanetti a., spagnolo g., poggi e. & balbi p. (2005) structural and compositional features of the mt. musinè peridotites (lanzo massif, western alps, italy) ofioliti, 30 (2), 161-173. firpo m., guglielmin m. & queirolo c. (2005) blockfields and blockstreams in the ligurian alps (mount beigua, italy) geogr. fis. dinam. quat., 28, 193-204. firpo m., guglielmin m. & queirolo c. (2006) relict blockfields in the ligurian alps (mount beigua, italy) permafrost and periglacial processes, 17, 71-78. goldich s.s. (1938) a study in rock-weathering journ. geol., 46, 17-58. gorbunov a.p., marchenko s.s. & seversky e.v. (2004) the termal environment of blocky materials in the mountains of central asia permafrost and periglac. process., 15, 95-98. grab s. (1999) block and debris deposits in the high drakensberg, lesotho, southern africa: implications for high alt itude slope processes geografiska annaler, 81 a, 1-16. guglielmin m. & smiraglia c. (1997) rock glacier inventory of the italian alps italian glaciological committee archive, 3, torino, 104 pp. harris s.a. & pedersen d.e. (1998) thermal regimes beneath coarse blocky materials permafrost and periglacial processes, 9, 107-120. harris s.a., cheng g., zhao x. & yongqin d. (1998) nature and dynamics of an active block stream, kunlun pass, qinghai province, people’s republic of china geografiska annaler, 80 a, 123-133. hay r.l. (1959) origin and weathering of late pleistocene ash deposits on st. vincent, b.w.i. jour. geol., 67, 65-87. joyce j.r.f. (1950) stone runs of the falkland islands geological magazine, 87, 105-115. kaczmarek m.a. & müntener o. (2005) exhumation of mantle lithosphere: field relations, and interaction processes between magmatism and deformation (field trip to the northern lanzo peridotite) ofioliti, 30 (2), 125-134. karaborni s., smit b., heidug w., urai j. & van oort e. (1996) the swelling of clays: molecular simulations of the hydratation of montmorillonite science, 271, 1102-1104. katti k. & katti d. (2003) effect of clay-water interactions on swell ing in montmoril lonite clay american society of civi l engineers. 16th engineering mechanics conference, july 16-18, 2003. universityof washington, seattle, 1-8. lovejoy e.m.p. (1972) wisconsin boulder flow and its geomorphic implications, franklin mountains, el paso county, texas geol. soc. am. bull., 83, 3501-3508. martinetto e. (1994) analisi paleocarpologica dei depositi continentali pliocenici della stura di lanzo boll. mus. reg. sci. nat. torino, 12 (1), 137-172. miè r. & natale p. (1978) fenomeni di alterazione paleoclimatica nel massiccio ultrabasico di lanzo boll. ass. min. sub., 15 (3-4), 1-47. mills h.h. (1988) surficial geology and geomorphology of the mountain lake area, giles county, virginia, includind sedimentological studies of colluvium and boulder streams u.s. geological survey professional paper 1469, 57 pp. natale p. (1972) nuove osservazioni sull'origine dei giacimenti di magnesite delle alpi occidentali boll. ass. min. sub., 9 (1-2), 107-124. nicolas a. (1974) mise en place des péridotites de lanzo (alpes piémontaises). relation avec tectonique et métamorphisme alpins: conséquences géodynamiques schweiz. mineral. petrogr. mitt., 54, 449-460. petrucci f. (1970) rilevamento geomorfologico dell'anfiteatro morenico di rivoli-avigliana (prov. torino) mem. soc. it. sci. nat., 18 (3), 95-124. piccardo g.b., müntener o., zanetti a., bruzzone s., poggi e., romairone a. & spagnolo g. (2004) the lanzo south peridotite: melt/peridotite interaction in the mantle lithosphere of the jurassic ligurian tethys ofioliti, 29 (1), 51-76. pognante u. (1989) lawsonite, blueschist and eclogite formation in the southern sesia zone (western alps, italy) eur. j. mineral., 1, 89-104. potter n. & moss j.h. (1968) origin of the blue rocks block field and adjacent deposits, berks county, pennsylvania geol. soc. am. bull., 79, 255-262. psilovikos a. & van houten f.b. (1982) ringing rocks barren block field, east-central pennsylvania sedimentary geology, 32, 233-243. ravazzi c., pini r., breda m., martinetto e., muttoni g., chiesa s., confortini f. & egli r. (2005) the lacustrine deposits of fornaci di ranica (late early pleistocene, italian pre-alps): stratigraphy, palaeoenvironment and geological evolution quaternary international, 131, 35-58. ravazzi c. & rossignol strick m. (1995) vegetation change in a climatic cycle of early pleistocene age in the leffe basin (northern italy) palaeogeography, palaeoclimatology, palaeoecology, 117, 105-122. smith h.t.u. & smith a.p. (1945) periglacial rock streams in the blue ridge area geol. soc. am. bull., 56, 1198. spalla m.i., de maria l., gosso g., miletto m. & pognante u. (1983) deformazione e metamorfismo della zona sesia-lanzo meridionale al contatto con la falda piemontese e con il massiccio di lanzo, alpi occidentali mem. soc. geol. it., 26, 499-514. sumner p.d. (2004) geomorphic and climatic implications of relict openwork block accumulations near thabana-ntlenyana, lesotho geografiska annaler, 86 a, 3, 289-302. twidale c.r. & vidal romanì j.r. (2005) landforms and geology of granite terrains a.a. balkema publishers, 351 pp. wahrhaftig c. & cox a. (1959) rock glaciers in the alaska range bull. geol. soc. am., 70, 383-436. whittecar g.r. & ryter d.w. (1992) boulder streams, debris fans, and pleistocene climate change in the blue ridge mountains of central virginia journal of geology, 100, 487-494. 22 ms. ricevuto il 2 settembre 2008 testo definitivo ricevuto il 7 gennaio 2009 ms. received: september 2, 2008 final text received: january 7, 2009 g. fioraso & g. spagnolo << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /none /binding /left /calgrayprofile (dot gain 20%) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /error /compatibilitylevel 1.4 /compressobjects /tags /compresspages true /convertimagestoindexed true /passthroughjpegimages true /createjdffile false /createjobticket false /defaultrenderingintent /default /detectblends true /colorconversionstrategy /leavecolorunchanged /dothumbnails false /embedallfonts true /embedjoboptions true /dscreportinglevel 0 /emitdscwarnings false 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mediterranean quaternary, 29 (2), 2016, 201 210 all together now: an international palynological team documents vegetation and climate changes during the last 500 kyr at lake ohrid (se europe) adele bertini1, laura sadori2, nathalie combourieu-nebout3, timme h. donders4, katerina kouli5, andreas koutsodendris6, sébastien joannin7, alessia masi2, anna maria mercuri8, konstantinos panagiotopoulos9, odile peyron7, gaia sinopoli2, paolatorri8, giovanni zanchetta10, alexander francke9, bernd wagner9 1 dipartimento di scienze della terra, università di firenze, firenze, italy 2 dipartimento di biologia ambientale, università di roma “la sapienza”, roma, italy 3 département de préhistoire, muséum national d’histoire naturelle, institut de paléontologie humaine, paris, france 4 palaeoecology, department of physical geography, utrecht university, utrecht, the netherlands 5 faculty of geology and geoenvironment, national and kapodistrian university of athens, athens, greece 6 institute of earth sciences, heidelberg university, heidelberg, germany 7 cnrs umr 5554, institut des sciences de l’evolution, université de montpellier, montpellier, france 8 dipartimento di scienze della vita, università di modena e reggio emilia, modena, italy 9 institute of geology and mineralogy, university of cologne, cologne, germany 10 dipartimento di scienze della terra, university of pisa, pisa, italy corresponding author: a. bertini <adele.bertini@unifi.it> abstract: lake ohrid (balkan peninsula) is the oldest european extant lake and one of the deepest and largest. such a unique, terrestrial natural archive is especially relevant for both paleoenvironmental and paleoclimatic reconstructions but also for genetic studies. in the frame of the international continental scientific drilling program (icdp), a deep drilling campaign was carried out within the scope of the scientific collaboration on past speciation conditions in lake ohrid (scopsco) project in 2013. here, we present the summary of palynological analyses carried out in the upper 200 m of the overall 569 m long deep site sediment succession from the central part of the lake. these studies, performed by an international palynological team, document the main floristic, vegetation and climate changes during the last ca 500 kyr, at a millennial-scale resolution (~1.6 kyr). the continuous sediment infill permitted to trace multiple non-forested/ forested phases as a response to glacial/interglacial cycles as well as to sub-milankovitch climate changes. the pollen record, corresponding with marine isotope stages mis 13 to mis 1, points to a progressive change from cooler and wetter to warmer and drier interglacials. new palynological studies are underway to reconstruct vegetational and climatic conditions over older intervals as well as to obtain high resolution data for some key intervals such as mis 5-6, mis 11-12, mis 35-42. the complete record of changes in flora composition and vegetation during both glacials and interglacials will furnish indispensable insights for understanding the role of refugia, ecosystem resilience and maintenance of terrestrial biodiversity in the mediterranean area. keywords: lake ohrid, pollen, flora, vegetation, climate, pleistocene, balkan peninsula 1. introduzione in 2013, within the frame of the international continental scientific drilling program (icdp), a deep drilling campaign was carried out as part of the scientific collaboration on past speciation conditions in lake ohrid (scopsco) project, on the balkan peninsula (fig. 1). several sites in lake ohrid (lo in the following), with the deepest one having a depth of some 568 m, were drilled to address several scientific aims (wagner et al., 2014). most important is to define both the depositional context and the range of past natural variability and magnitude of climate changes within a coherent chronologic frame. previous molecular clock analyses of dna on endemic genera (e.g. dina, hirudinea, erpobdellidae) that have evolved within the lake suggested, by estimating the onset of intralacustrine diversification, a time frame of approximately 2-3 ma (trajanovski et al., 2010). however recent evidence indicates an age of 1.2-1.9 ma for the origin of lo (wagner et al., 2014; lindhorst et al., 2015). the occurrence of freshwater endemic species (including both flora and fauna taxa) was also a prime motivation for the study of present conditions at lo in order to observe their response to the increasing anthropogenic pressure in the lake. based on field surveys, monitoring data, published records, expert interviews, conservation concerns and associated major threats were traced (e.g. kostoski et al., 2010). palynology, together with a large amount of geological and stratigraphical investigations (franke et al., 2016) was applied to the study of the lo sedimentary succession since 2014, especially to provide evidence on the history of changes of both flora composition and vegetation structure. both items are indispensable for climate deductions as well as to assess the distribution work presented during the aiqua scientific conferences "waiting for the nagoya inqua xix congress", held in florence, june 18 19, 2015 202 a. bertini et al. of plant refugia in southern balkans, i.e. one of the three mediterranean refuge areas so far identified along with southern iberian peninsula and southern italy. such evidence is especially relevant to get a better understanding of the role played by (glacial) refugia in vegetation dynamics during the pleistocene in europe (e.g. médail & diadema, 2009; fletcher et al., 2013; tzedakis et al., 2013 and references therein). here we summarize and discuss the first results of palynological studies, carried out by an international team of palynologists, from the upper part of the deep site sediment succession and covering the last 500 kyr (francke et al., 2016; sadori et al., 2016). the palynology work schedule for the year 2016 is also presented. 2. general setting lake orhid (40°54′-41°10′ n and 20°38′-20°48′ e; fig. 1) is located at the border between albania and the former yugoslav republic of macedonia (fyrom), at an altitude of 693 m above sea level (a.s.l.). the icdp deep drilling campaign took place using the deep lake drilling system (dlds) operated by the drilling, observation and sampling of the earths continental crust (dosecc) consortium, in spring 2013. more than 2100 m of sediments were recovered from four different drill sites (figs 2, 3); onsite core processing comprised analyses of core catcher material and magnetic susceptibility measurements. all cores were shipped to the university of cologne for in progress and future analyses (figs 4, 5; i.e. lithological, sedimentological, and biogeochemical). the main drill site in the central part of the lake (fig. 1; 41°02’57’’ n, 20°42’54’’ e) permitted to recover 1526 m of core in total (deep site 5045-1) in six overlapping holes down to a maximum composite depth of 569 m. for more details see francke et al. (2016) and references therein. 2.1. present features lake ohrid, 30.3 km long and 15.6 km wide, covers an area of ca 360 km2 (fig. 1); its maximum water depth is 293 m. lo is mainly fed by groundwater from karstic sources in the relatively small natural catchment area of 1042 km2, which was artificially enlarged to 1487 km2 in 1962 (matzinger et al., 2006). however the occurrence of several surface springs and possibly also some subaquatic inflows from the nearby lake prespa (10 km to the east, at 849 m a.s.l., i.e. around 150 m above lo from which is separated by the galičica mountain range) are responsible for a larger effective size of the catchment (stankovic, 1960; matzinger et al., 2006; fig. 1). the surface outflow of lo is the river crni drim in the northern part of the lake, which accounts for 63% of the water loss, with the remaining 37% accounted for by fig. 1 location map of lake ohrid (modified from panagiotopoulos, 2013). 203 vegetation and climate changes during the last 500 kyr ............ evaporation (watzin et al., 2002). the current lake state is oligotrophic, due to the large water volume and the low nutrient availability (wagner et al., 2010). the thermopluviometric diagram of the struga meteorological station shows the main climate features for the close area located north of lo, at an altitude of 694 m (figs. 1, 6). the average annual temperature is here 11.3 °c. the annual precipitation amounts to 878 mm. july is the warmest and driest month, with an average temperature of 20.5 °c and 42 mm of rain. most of the precipitation falls in november, averaging 114 mm. january is the coldest month, with temperatures averaging 2.0 °c. this climate is considered to be cfb (temperate rainy climate, warm summers) according to the köppen-geiger climate classification (e.g. kottek et al., 2006). the catchment vegetation (see fig. 7a and b for some panoramic views) is distributed mainly in altitudinal belts, from the lake level (700 m) to the top of mountains (>2200 m), with mixed deciduous oak forest, beech forest at lake level followed at higher elevation by mesophilous/ montane species; mixed forests at the upper limit of the forested area and alpine pasturelands and grasslands are found over the timberline, currently at around 1900 m (matevski et al., 2011). the presence of glaciers is documented on top of the galičica mountains during glacial periods (ribolini et al., 2011). fig. 2 the barge at the deep site at lake ohrid (photo courtesy s. schorr). fig. 3 the hbi boat/core handing at lake ohrid on april 2013. on board researchers of cologne university: b. wagner, n. leicher and f. wild. (photo courtesy s. schorr) fig. 4 cores in the refeer at the university of cologne (a, b), (photo courtesy s. schorr) fig. 5 core description and processing at the university of cologne. at work n. leicher and colleagues. (photo courtesy s. schorr). a b 2.2. geological and stratigraphical framework the lo morphostructure with high mountains to the west (“mokra mountain” chain, up to 2156 m) and east (“galičica mountain” chain, up to 2254 m) (fig. 1) is mainly the result of a pull-apart like opening of the basin during the late phases of the alpine orogeny (aliaj et al., 2001; hoffmann et al., 2010). the oldest bedrock (devonian) is present in the northeastern part of the basin whereas triassic carbonates and siliciclastics occur in the southeast, east, and northwest (e.g., wagner et al., 2009; hoffmann et al., 2010; vogel et al., 2010). jurassic and cretaceous metamorphic and magmatic rocks crop out in the west (hoffmann et al., 2010). quaternary lacustrine and fluvial deposits cover the plains to the north and to the south (hoffmann et al., 2010; vogel et al., 2010) overlaying pliocene continental mudstones and claystones. the tectonic activity in the area is attested, until present day, in the lateral parts of lo (reicherter et al., 2011; lindhorst et al., 2012; wagner et al., 2012) by several earthquakes (neic database, usgs) and mass wasting deposits (lindhorst et al., 2016). 2.3. summary of main project results most of the data collected by various investigators, during the 2 years following the core-drilling period since 2013, have been focused on lithology, sedimentology, tephrostratigraphy, and (bio-) geochemistry (see for all details wagner et al., 2014, francke et al., 2016 and references therein, leicher et al., 2016). here we summarize those results from studies carried out in cores from the central part of the lake giving, in the next paragraph, special emphasis to the palynological contribution (sadori et al., 2016) concerning the upper 200 m of the overall 569 m long deep site sediment succession. 1. the deep site sediment succession (in francke et al., 2016) consists of hemipelagic sediments including several tephra layers and rare mass wasting deposits (< 5 cm). they were organized, on the basis of the initial core description and the calcite content, into three main lithotypes (1-3). lithotypes 1 and 2 deposits comprise calcareous and slightly calcareous silty clay respectively, whereas lithotype 3 deposits consist of clastic, silty clayey material. 2. the tectono-sedimentary structure of the basin as reconstructed by lindhorst et al. (2015) includes three main seismic units overlying the acoustic basement associated with fluvial deposits and lacustrine sediments. the seismic facies analysis revealed a prominent cyclic pattern associated with glacial/ interglacial cycles with a mean sedimentation rate of 0.41 mm yr-1 for the last 430 kyrs. 3. according to the age model based on radiometric ages of eleven tephra layers (1st order tie points) and fig. 6 the thermopluviometric diagram of struga metereological station (fig. 1) at the north side of lake ohrid (data from http://en.climate -data.org/location/29778/). fig. 7 view of the present vegetation around lake ohrid. (a) saint john at kaneo; (b) the rocky southeastern shore of the lake. 204 a. bertini et al. a b on tuning of biogeochemical proxy data to orbital parameters (2nd order tie points; laskar et al., 2004), the upper portion of the sedimentary succession, 247.8 m thick, covers the last 637 kyr (francke et al., 2016, leicher et al., 2016). 4. according to the isotopes (δ18o and δ13c) from the upper ca 247.5 m of sediments, lo experienced a period of general stability between mis 15 to 13. wetter climate conditions characterized both mis 11 and mis 9. the successive interglacials were marked by progressively drier conditions (lacey et al., 2016). 3. the palynological contribution the first scopsco palynological meeting was held at the dipartimento di biologia ambientale in rome (italy) on 8 and 9 january 2014. it led to the composition of an international palynological team with 12 european scientists from 5 countries under the supervision and coordination of laura sadori (university of rome). in order to provide coherent flora and vegetation data, indispensable for both successive quantification analyses to infer regional paleoclimatic signals and to ensure comparability of results among the different laboratories, common protocols for both chemical-physical and microscope analyses were discussed and established. moreover cross-check analyses on selected pollen samples by more than one analyst were adopted. 3.1. protocol for laboratory analyses each sample, previously described for its main visual lithological features was weighed and 0.5 to 1.5 g of dry sediment were chemically treated. in order to estimate the pollen concentration, two tablets containing a known amount of lycopodium spores (stockmarr, 1971) were added in this first step to ensure that all palynomorphs will be treated similarly. the different chemical attacks (see below) were each time followed by both washing of sediment with distilled water and decantation. hcl (37%) was used to remove the carbonate fraction of the sediment as well as to dissolve the lycopodium tablets. hf (40%) was used to remove silicates and hot naoh (10%) to disperse organic matter and remove humic acids. at the end some drops of glycerol were added to the residue. for the present work 306 sediment samples, at 64 cm interval down to the depth of 197.55 m of the deep core have been processed. 3.2. protocol for optical microscope analysis the list of pollen flora taxa, the counts, diagrams, bibliographic and photographic documentation are available to all components of the palynological team in a shared cloud folder. here several general articles on both modern and ancient pollen taxa are also available. special emphasis was given to selected taxa in order to facilitate their morphological identification and taxonomy. the difficulty and even the impossibility to always precisely discriminate, at the optical microscope, the different deciduous, semi-deciduous and evergreen components of the genus quercus has long been discussed as they obviously produce some limitations for the ecological and climatic reconstructions. beug (2004), chester & raine (2001), reille (1992, 1995, 1998) and smit (1973) documentation and criteria were carefully evaluated. finally we decided to apply an informal subdivision, which possibly represents, at present, the best compromise for analyses at the optical microscope despite it was originally defined by electron microscope analyses (smit, 1973). accordingly, oak pollen has been divided in three main types: quercus robur type (including all deciduous oaks), quercus ilex type (including all the evergreen oaks minus q. suber) and quercus cerris type (including semi-deciduous oaks plus q. suber). juniperus type was established to include pollen grains of cupressus, juniperus and taxus. further efforts are being made to collect materials in view of the ongoing studies on the oldest intervals in the sedimentary core, especially pictures of pollen grains belonging to taxa having a good spread in the mediterranean area during pliocene and early pleistocene and now showing a disjunct geographical distribution. for the interval under examination, special attention was paid to trace the occurrence and abundance of some taxa such as carya, cathaya, cedrus, hamamelidaceae, liquidambar, pterocarya, tsuga, zelkova. 3.3. the time schedule the project unfolds over three main steps. the two first allow the study of the entire sedimentary succession at low resolution (from the top down to 200 m, i. e. the present study and from 200 m to the bottom core, respectively), in relatively short time. according to the age model by francke et al. (2016) the mean resolution between two samples from the upper portion is ~1600 years. being the first step just accomplished (sadori et al., 2016), the study of the interval between 200 m and the bottom core has started (step 2). at the same time higher resolution analyses (step 3) are also in progress in the sedimentary portions corresponding to miss 5-6, 10-12, 35-42. 3.4. palynological results and discussion palynological analyses pointed out a rich palynoflora including 175 taxa (153 terrestrial plants including 10 freshwater plants). quantitative data high enough to trace different pollen diagrams were possible in 296 of the 306 available samples (see, figs 2, 3 and table 1 in sadori et al., 2016). samples with final counts less than 80 pollen grains (in addition to pinus) were excluded. mean pollen counts of 824 terrestrial pollen grains have been achieved. pollen concentration is quite variable, ranging from ca. 4000 to ca. 910,000 pollen grains g-1. pollen grains do no exhibit major mechanisms of degradation but bisaccate pollen, especially pinus, is often fragmented. dinoflagellate cysts are sporadically present. significant reworking phenomena were absent, as also indicated by the lithology, except of very few, thin mass movement deposits (francke et al., 2016). pollen assemblages in the upper 200 m are characterized by a general good richness, which however fluctuates in its values in dependence of both climate (being lower during glacials and higher during interglacials) and time interval (e.g. richness in nap notably increases in the younger intervals). the main floristic features are summarized below. trees are mainly represented by pinus 205 vegetation and climate changes during the last 500 kyr ............ pollen. among other pinaceae taxa, abies and picea are present throughout; tsuga is scattered and cedrus as well as cathaya are absent. deciduous broadleaved trees are represented mainly by quercus spp. followed by carpinus betulus, ostrya/carpinus orientalis, ulmus, zelkova, acer, tilia and juglans. among the only sporadically present taxa we number celtis and carya. among mediterranean trees, quercus ilex type is dominant with phillyrea, pistacia, plus the pioneer shrub hippophaë. betula and especially fagus occur in a discontinuous way. herbaceous/non arboreal taxa are particularly represented by pollen of asteraceae, especially artemisia, poaceae and amaranthaceae. moreover cyperaceae, caryophyllaceae, ranunculaceae, helianthemum, plantaginaceae. polygonaceae, rubiaceae, euphorbiaceae, dipsacaceae, gentianaceae, rosaceae and caprifoliaceae also occur but discontinuously and at low frequencies. pteridophyta are generally well represented. algal taxa are principally represented by pediastrum and botryococcus, though discontinuously. the analysis of changes in pollen concentration and percentages of both single taxa and arboreal pollen sum (ap) versus non-arboreal pollen sum (nap), is summarized in fig. 8. in the text pinus percentages refer to a pollen sum including all ap (plus pinus) and nap; all the other taxa were calculated with respect to the pollen sum of ap (but pinus excluded) and nap. a prevalent contraposition between non arboreal pollen (including poaceae, amaranthaceae, artemisia) and woodland (including abies, picea, quercus robur type, quercus cerris type) taxa is well evident throughout the sedimentary succession (fig. 8). such pattern reflects the vegetational response to the succession of glacial/interglacial cycles between mis 13 and mis 1 (francke et al., 2016). moreover, minor expansions of ap during glacials as well as forest opening during interglacials pointed out interstadials and stadials, respectively. glacials at lo at lo (fig. 8), pollen zones od-12, od-11, od-9 and od-7 roughly corresponding to older glacials mis 12, mis 10 and mis 8 exhibit poaceae as the most abundant nap taxon, followed sometimes by cyperaceae (mis 12) or amaranthaceae (mis 10), and subsequently by asteroideae, cichorioideae, artemisia and hippophaë (particularly abundant during mis 10); pinus as a whole, shows a large occurrence in both concentration and percentage values, exhibiting striking relatively millennial-scale variations in addition to the glacial -interglacial cycles. it fluctuates between 28% and 98%. montane coniferous taxa show significant fluctuations too as expressed by picea (range 0%67%) and abies (range 0%-63%). mis 8 is marked with respect to mis 12 and 10 by a peculiar increase of both juniperus and artemisia. the younger glacials are marked by successive distinct patterns in the abundances of some taxa. from mis 6 onwards a progressive decrease of pinus, as well as of abies and picea, parallels a notable increase of artemisia followed by poaceae and amaranthaceae. a relevant increase of juniperus (up to 55%) marks the top of mis 6. the establishment of harsh climate conditions possibly promoted various environmental changes; it is a fact that montane taxa, after mis 6, never reach previous values. the successive, younger glacials are especially characterized by the dominance of artemisia followed by poaceae and amaranthaceae; pinus still well represented in percentages, shows a remarkable decrease in concentrations since mis 6. abies shows a slight percentage increase just after the onset of mis 5 whereas picea occurs sporadically and in low values. overall total pollen concentration during glacials is lower than in interglacials; probably the larger expansion of open environments (i.e. herbaceous taxa) or even bare soils, which favored enhanced phases of erosion and transport of clastic material in the basin may have diluted the pollen content. such depositional processes are expressed by the rather exclusive occurrence of lithotype 3 sediments, except lithotype 1 in mis 8 (francke et al., 2016). interglacials at lo the climate signature in the depositional environment is well expressed by the dominance of a peculiar and diverse pattern with respect to that dominant during glacials. in fact during interglacials lithotypes 1 and 2 sediments prevail with rare occurrences of lithotype 3 sediments. a progressive overall shift from cooler and wetter to warmer and drier interglacials was pointed out. as a whole the strong chronological frame for lo enables precise terrestrial-marine correlations using the comparison with the main coeval regional sites (e.g. follieri et al., 1989; okuda et al., 2001; tzedakis et al., 2004; 2006; brauer et al., 2007; roucoux et al. 2008, 2011; litt et al., 2014; pross et al., 2015) and synchronization of single marine isotope stages (zanchetta et al., 2016). a striking feature of lo respect to the other long terrestrial pollen records of europe and near east, is the relatively continuous presence of taxa from all major vegetation belts despite the significant glacial/interglacial variability throughout the profile. in particular, similar patterns of vegetation development during the last glacial/interglacial cycles are testified by previous palynological studies (panagiotopoulos et al., 2014) on the adjacent lake prespa (fig. 1) for the last 92 ka. similar forested phases, dominated by deciduous trees indicative of higher temperatures and moisture availability, developed during both mis 5 and mis 1. open landscapes during lower temperatures and moisture availability phases were prevalent during mis 4, 2, and also 3 despite the significant presence of temperate trees. with respect to prespa, the longer lo pollen record provides a unique documentation of the history of flora composition and vegetation structure here updated to the mis 13 p.p. according to the summary ap vs nap diagram (fig. 8) an overall progressive enlargement of the open vegetal formations is quite evident since mis 13, with a major rise to dominance of steppe formations with artemisia (fig. 8) occurring from the mis 7/mis 6 transition onwards. the quite long glacial mis 6 is especially marked by a sig 206 a. bertini et al. nificant increase for artemisia, which reaches values up to ca 47%. ongoing pollen-based climate reconstructions will be able to establish the magnitude of changes in temperatures but especially in the regime of precipitations. the persistent dry conditions during mis 6 probably enhanced intense erosive processes. after this significant paleoenvironmental and paleoclimate change, probably the major of the last 500 kyr, we observe a general reduction of the altitudinal coniferous taxa (abies and picea) particularly evident during interglacials. possibly a progressive and generalized decrease in the humidity values plays a major role in the reorganization of vegetation assemblages. such a prominent event is traceable for picea (see fig. 2 in sadori et al., 2016) which became subordinated with respect to abies since mis 6. the knowledge of both the stratigraphic distribution and the past change in the abundances of previous taxa is really helpful to assess their current spatial distribution under the effects of different ecological processes (e.g., competition, survival, biological diversity) within forest communities as well as to choose correct preservation and conservation strategies. fig. 8 summary pollen data of lake ohrid (fyrom), deep core against chronology (francke et al., 2016). from the left: marine records, lr04 δ18ο benthic stack (lisiecki and raymo, 2005); terrestrial records, percentages summary pollen diagrams, and selected concentration pollen curves. ap: arboreal plants; nap: non arboreal plants; mis: marine isotope stages; pasz: pollen assemblage superzones. 207 vegetation and climate changes during the last 500 kyr ............ ka (marine isotope stages 9c-a, 8 and 7e) from tenaghi philippon, ne greece. quaternary science reviews, 78, 108-125. follieri m., magri d., sadori l. (1989) pollen stratigraphical synthesis from valle di castiglione (roma). quaternary international, 3-4, 81-84. francke a., wagner b., just j., leicher n., gromig r., baumgarten h., vogel h., lacey j.h., sadori l., wonik t., leng m.j., zanchetta g., sulpizio r., giaccio b. (2016) sedimentological processes and environmental variability at lake ohrid (macedonia, albania) between 637 ka and present. biogeosciences, 13, 1179-1196. hoffmann n., reicherter k., fernández-steeger t., grützner c. (2010) evolution of ancient lake ohrid: a tectonic perspective. biogeosciences, 7, 3377-3386. kostoski g., albrecht c., trajanovski s., wilke t. (2010) a freshwater biodiversity hotspot under pressure assessing threats and identifying conservation needs for ancient lake ohrid. biogeosciences, 7, 3999-4015. kottek m., grieser j. beck c., rudolf b., rubel f. (2006) world map of the köppen-geiger climate classification updated. meteorologische zeitschrift, 15 (3), 259-263. lacey j.h., leng m.j., francke, a., sloane h.j., milodowski a., vogel h., baumgarten h., zanchetta g., wagner b. (2016) northern mediterranean climate since the middle pleistocene: a 637 ka stable isotope record from lake ohrid (albania/macedonia). biogeosciences, 13, 18011820. laskar j., robutel p., joutel f., gastineau m., correia a.c.m., levrard b. (2004) a long-term numerical solution for the insolation quantities of the earth. astron. astrophys., 428, 261-285. leicher n., zanchetta g., sulpizio r., giaccio b., wagner b., nomade s., francke a. (2016) first tephrostratigraphic results of the deep site record in lake ohrid, macedonia. biogeosciences, 13, 2151-2178. lindhorst k., gruen m., krastel s., schwenk t. (2012) hydroacoustic analysis of mass wasting deposits in lake ohrid (fyr macedonia/albania), in: submarine mass movements and their consequences, edited by: yamada y., kawamura k., ikehara k., ogawa y., urgeles r., mosher d., chaytor j., strasser m. springer, the netherlands, 245-253. lindhorst k., krastel s., reicherter k., stipp m., wagner b., schwenk t. (2015) sedimentary and tectonic evolution of lake ohrid (macedonia/albania). basin research, 27, 84-101. lindhorst k., krastel s., baumgarten h. (2016) mass wasting history within lake ohrid basin (macedonia/albania) over the last 600 ka, submarine mass movements and their consequences: 7th international symposium. g. lamarche, j. mountjoy, s. bull et al. cham, springer international publishing, 291-300. lisiecki l.e., raymo m.e. (2005) a pliocenepleistocene stack of 57 globally distributed benthic 4. conclusion lo is a unique continental site including at least the last 1.2 ma history of changes on the balkan peninsula, a key area of the mediterranean. the productive collaboration among the different components of the international palynological team provided effective implementation of the scopsco project being a long and continuous pollen record for the last 500 kyr produced in a short period of time for the standard time requested by palynological analyses. the achievement of this first step (step 1) as well as the ongoing collaboration aimed at the completion of the entire record by the end of 2016 (step 2) and to the implementation of high resolution studies in key intervals (step 3) are truly relevant, the full pollen record permitting to trace by the analysis over multiples glacial/interglacial cycles i. the climate variability since 1.2 ma when subtropical ecosystems disappeared from the central mediterranean area, ii. the history of taxa migration and extinctions under the effects of regional to global events iii. the role of refugia areas over time. the palynological evidence along with the geological, micropaleontological and stratigraphical data, now well documented by a large number of studies, provide indispensable elements of knowledge for the reconstruction of the late quaternary paleoclimatic changes in the eastern mediterranean area within a strong chronologic frame. such an integrated approach has paramount importance as it permits to trace a comprehensive paleoenvironmental history of lo which is needed to both its appropriate present management and in the context of predicting its future. acknowledgements the scopsco lake ohrid drilling campaign was funded by icdp, the german ministry of higher education and research, the german research foundation (dfg), the university of cologne, the british geological survey, the ingv and cnr of italy, and the governments of the republic of macedonia (fyrom) and albania. references aliaj s., baldassarre g., shkupi d. (2001) quaternary subsidence zones in albania: some case studies. b. eng. geol. environ., 59, 313-318. beug h.j. (2004) leitfaden der pollenbestimmung für mitteleuropa und angrenzende gebiete, verlag dr. friedrich pfeil, münchen, germany. brauer a., allen j.r. m., mingram j., dulski p., wulf s., huntley b. (2007) evidence for last interglacial chronology and environmental change from southern europe. p. natl. acad. sci. usa, 104, 450455. chester p.i., raine j.i. (2001) pollen and spore keys for quaternary deposits in the northern pindos mountains, greece. grana, 40, 299-387. fletcher w.j., müller u.c., koutsodendris a., christanis k., pross j. (2013) a centennial-scale record of vegetation and climate variability from 312 to 240 208 a. bertini et al. roucoux k.h., tzedakis p.c., lawson i.t., margari v. (2011) vegetation history of the penultimate glacial period (marine isotope stage 6) at ioannina, north-west greece, j. quaternary sci., 26, 616626. sadori l., koutsodendris a., panagiotopoulos k., masi a., bertini a., combourieu-nebout n., francke a., kouli k., joannin s., mercuri a.m., peyron o., torri p., wagner b., zanchetta g., sinopoli g., donders t.h. (2016) pollen-based paleoenvironmental and paleoclimatic change at lake ohrid (se europe) during the past 500 ka. biogeosciences, 13, 1423-1437. smit a. (1973) a scanning electron microscopical study of the pollen morphology in the genus quercus. acta bot. neerl., 22, 655-665. stankovic s. (1960) the balkan lake ohrid and its living world, monogr. biol. ix, uitgeverij dr. w. junk, den haag, the netherlands. stockmarr j. (1971) tablets with spores used in absolute pollen analysis. pollen spores, 13, 615-621. trajanovski s., albrecht c., schreiber k., schultheiß r., stadler,t., benke,m., wilke t. (2010) testing the spatial and temporal framework of speciation in an ancient lake species flock: the leech genus dina (hirudinea: erpobdellidae) in lake ohrid. biogeosciences, 7, 3387-3402. tzedakis p.c., roucoux k.h., de abreu l., shackleton n.j. (2004) the duration of forest stages in southern europe and interglacial climate variability. science, 306, 2231-2235. tzedakis p.c., hooghiemstra h., pälike h. (2006) the last 1.35 million years at tenaghi philippon: revised chronostratigraphy and long-term vegetation trends. quaternary science reviews, 25, 34163430. tzedakis p.c., emerson b.c., hewitt g.m. (2013) cryptic or mystic? glacial tree refugia in northern europe. trends ecol. evol., 28, 696-704. vogel h., wessels m., albrecht c., stich h.b., wagner, b. (2010) spatial variability of recent sedimentation in lake ohrid (albania/ macedonia). biogeosciences, 7, 3333-3342. wagner b., lotter a.f., nowaczyk n., reed j.m., schwalb a., sulpizio r.,valsecchi v., wessels m., zanchetta g. (2009) a 40,000-year record of environmental change from ancient lake ohrid (albania and macedonia). j. paleolimnol., 41, 407430. wagner b., vogel h., zanchetta g., sulpizio r. (2010) environmental change within the balkan region during the past ca. 50 ka recorded in the sediments from lakes prespa and ohrid. biogeosciences, 7, 3187-3198. wagner b., francke a., sulpizio r., zanchetta g., lindhorst k., krastel s., vogel h., rethemeyer j., daut g., grazhdani a., lushaj b., trajanovski s. (2012) possible earthquake trigger for 6th century mass wasting deposit at lake ohrid (macedonia/albania). clim. past, 8, 2069-2078. wagner b., wilke t., krastel s., zanchetta g., sulpizio r., reicherter k., leng m.j., grazhdani a., trajanovski s., francke a., lindhorst k., levkov δ18o records. paleoceanography, 20, pa1003. litt t., pickarski n., heumann g., stockhecke m., tzedakis p.c. (2014) a 600,000 year long continental pollen record from lake van, eastern anatolia (turkey). quaternary science reviews, 104, 30-41. matevski v., čarni a., avramovski o., juvan n., kostadinovski m., košir p., marinšek a., paušič a., šilc u. (2011) forest vegetation of the galičica mountain range in macedonia. založba zrc, ljubljana. matzinger a., spirkovski z., patceva s., wuest a. (2006) sensitivity of ancient lake ohrid to local anthropogenic impacts and global warming. j. great lakes res., 32, 158-179. médail f., diadema k. (2009) glacial refugia influence plant diversity patterns in the mediterranean basin. j. biogeogr., 36, 1333-1345. okuda m., yasuda y., setoguchi t. (2001) middle to late pleistocene vegetation history and climatic changes at lake kopais, southeast greece. boreas, 30, 73-82. panagiotopoulos k. (2013) late quaternary ecosystem and climate interactions in sw balkans inferred from lake prespa sediments. ph.d. thesis, universität zu köln, germany. panagiotopoulos k., böhm a., leng m., wagner b., schäbitz f. (2014) climate variability over the last 92 ka in sw balkans from analysis of sediments from lake prespa. clim. past, 10, 643-660. pross j., koutsodendris a., christanis k., fischer t., fletcher w.j., hardiman m., kalaitzidis s., knipping m., kotthoff u., milner a.m., müller u.c., schmiedl g., siavalas g., tzedakis p.c., wulf s. (2015) the 1.35 ma-long terrestrial climate archive of tenaghi philippon, northeastern greece: evolution, exploration and perspectives for future research. newsl. stratigr., 48, 253-276. reicherter k., hoffmann n., lindhorst k., krastel s., fernandez-steeger t., grützner c., wiatr t. (2011) active basins and neotectonics: morphotectonics of the lake ohrid basin (fyrom and albania). z. dtsch. ges. geowiss., 162, 217-234. reille m. (1992) pollen et spores d’europe et d’afrique du nord. laboratoire de botanique historique et palynology, marseille, france, 520 pp. reille m. (1995) pollen et spores d’europe et d’afrique du nord. supplement i. laboratoire de botanique historique et palynology, marseille, france, 327 pp. reille m. (1998) pollen et spores d’europe et d’afrique du nord. laboratoire de botanique historique et palynologie. supplement ii, marseille, france, 521 pp. ribolini a., isola i., zanchetta g., bini m., sulpizio r. (2011) glacial features on the galičica mountains, macedonia, preliminary report. geogr. fis. dinam. quat. 34, 247-255. roucoux k.h., tzedakis p.c., frogley m.r., lawson i.t., preece r.c. (2008) vegetation history of the marine isotope stage 7 interglacial complex at ioannina, nw greece. quaternary science reviews, 27, 1378-1395. 209 vegetation and climate changes during the last 500 kyr ............ z., cvetkoska a., reed j.m., zhang x., lacey j.h., wonik t., baumgarten h., vogel h. (2014) the scopsco drilling project recovers more than 1.2 million years of history from lake ohrid. sci. dril., 17, 19-29. watzin m.c., puka v., naumoski t.b. (eds.) (2002) lake ohrid and its watershed, state of the environment report, lake ohrid conservation project. tirana, albania and ohrid, macedonia, 134 pp. zanchetta g., regattieri e., giaccio b., wagner b., sulpizio r., francke a., vogel h., sadori l., masi a., sinopoli g., lacey j.h., leng m.j., leicher n. (2016) aligning and synchronization of mis 5 proxy records from lake ohrid (fyrom) with independently dated mediterranean archives: implications for deep core chronology. biogeosciences, 13, 2757-2768. 210 a. bertini et al. ms. received: july 15, 2016 final text received: september 18, 2016 << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /none /binding /left /calgrayprofile (dot gain 20%) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /error /compatibilitylevel 1.4 /compressobjects /tags /compresspages true /convertimagestoindexed true /passthroughjpegimages true /createjobticket false /defaultrenderingintent /default /detectblends true /detectcurves 0.0000 /colorconversionstrategy /cmyk /dothumbnails false /embedallfonts true /embedopentype false /parseiccprofilesincomments true /embedjoboptions true /dscreportinglevel 0 /emitdscwarnings false 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can be opened with acrobat and adobe reader 5.0 and later.) >> /namespace [ (adobe) (common) (1.0) ] /othernamespaces [ << /asreaderspreads false /cropimagestoframes true /errorcontrol /warnandcontinue /flattenerignorespreadoverrides false /includeguidesgrids false /includenonprinting false /includeslug false /namespace [ (adobe) (indesign) (4.0) ] /omitplacedbitmaps false /omitplacedeps false /omitplacedpdf false /simulateoverprint /legacy >> << /addbleedmarks false /addcolorbars false /addcropmarks false /addpageinfo false /addregmarks false /convertcolors /converttocmyk /destinationprofilename () /destinationprofileselector /documentcmyk /downsample16bitimages true /flattenerpreset << /presetselector /mediumresolution >> /formelements false /generatestructure false /includebookmarks false /includehyperlinks false /includeinteractive false /includelayers false /includeprofiles false /multimediahandling /useobjectsettings /namespace [ (adobe) (creativesuite) (2.0) ] /pdfxoutputintentprofileselector /documentcmyk /preserveediting true /untaggedcmykhandling /leaveuntagged /untaggedrgbhandling /usedocumentprofile /usedocumentbleed false >> ] >> setdistillerparams << /hwresolution [2400 2400] /pagesize [612.000 792.000] >> setpagedevice base growth process of a long-lived late pleistocene spit along the adriatic coast (brindisi, southern italy) francesco loiacono dipartimento di geologia e geofisica università degli studi “aldo moro”, bari corresponding author: f. loiacono <loiacono@geo.uniba.it> abstract: loiacono f., growth process of a long-lived late pleistocene spit along the adriatic coast (brindisi, southern italy). (it issn 0394-3356, 2010). the quaternary succession cropping out along the cliff at nw and se of brindisi town (adriatic coast, southern italy), is mainly composed of silty sands and is referred to lower-middle pleistocene by biostratigraphic integrated analyses. moreover the benthic assemblage of the cropping out sequence indicates a shallowing upward trend. a coarse grained calcarenite body (punta penne calcarenites), overlies unconformably the middle pleistocene fine-grained sediments cropping out along the coast for more than 9 km and for up to ten meters thick, thus making a good shelter for the brindisi port and town. the sedimentological analysis carried out through this well exposed sedimentary body allows to recognize its growth process and make some hypotheses on the control factors acting during its development. the sedimentary body is composed of bioclastic grainstones and rudstones arranged in well bedded succession made up of about 30° se dipping beds and bed sets in a cyclic alternation of coarse-grained planar units (facies a), smallto medium-scale trough cross-bedded units (facies b), and bichordites-bearing beds (facies c). facies analyses point out a storm-dominated, foreshore-to-upper shoreface environment, characterized by migrating bedforms such as ripples, megaripples and low-angle or quasi-parallel flat beds. in this scenario, the aforementioned units’ alternation is the result of the se-trending lateral accretion of a coastal spit, which developed accordingly to the dominant longshore currents, similar to the present day ones. the spit sedimentary body becomes thinner toward se; its upper boundary is sharp, being covered by recent soil; locally, holocene aeolian sands overlay the spit deposits, recording the last highstand. the alignment of this coastal spit results from two interactive factors: the abrupt change in the coastline profile and a long balance between material supply (uplift-erosion) and alongshore movement. the first control factor was a differential subsidence rate of the coast in this area that caused different wave refraction and high erosion of the bend point. the se-directed dominant longshore currents were also highly efficient in the transport and down-current deposition of the sediment load. the seward accretion of the coastal spit followed a long balancing of local subsidence, sediment production and lateral accumulation. in time the decreasing efficiency of the longshore transport and lateral accretion caused facies changes with increase in depth. finally in the se direction the stratigraphic record is regressive according to the regional trend. grain size local trends and measurements of foreset and festoon dips allow the distinguishing of frontal, seaand land sides of the spit, as well as the likely changes in the growth stages and its dying out. the duration of the spit construction could be limited to a few thousand years in a time interval corresponding to tirrenian maximux highstand (mis 5 e). riassunto: loiacono f., genesi e sviluppo di uno “spit” pleistocenico (litorale adriatico, brindisi). (it issn 0394-3356, 2010). la successione sedimentaria quaternaria affiorante in estesi tratti del litorale brindisino è costituita da una formazione sabbioso-siltosa attribuita al pleistocene inferiore-medio (coppa et al., 2001) in giacitura suborizzontale, ben visibile lungo le falesie che mostrano evidenti segni di arretramento. in alcuni tratti sono presenti, a livello del mare, affioramenti di calcareniti ben cementate, localmente discordanti sulle sabbie siltose, che costituiscono un corpo sedimentario e che contrastano l’azione demolitrice del mare, rappresentando tratti sporgenti di costa rocciosa. il corpo sedimentario più esteso e più spettacolare è dato dalle “calcareniti di punta penne” che affiorano in modo continuo per circa 9 km nel tratto compreso tra punta penne e capo di t. cavallo e costituiscono un’ottima protezione per il porto di brindisi. attraverso indagini stratigrafiche e analisi sedimentologiche sono stati ricostruiti: il contesto stratigrafico, i processi e gli ambienti deposizionali, nonché i fattori di controllo che hanno agito durante la sedimentazione. la geometria di questo corpo sedimentario litologicamente omogeneo (calcareniti medio-grossolane /calciruditi) appare cuneiforme con lo spessore maggiore nella sua estremità nord-occidentale e tendente a chiudersi verso se. lo spessore stratigrafico reale ,ricavato da alcuni sondaggi, è di circa 10 metri, mentre l’estensione in senso parallelo alla costa è di circa 9 km. il carattere principale è la stratificazione obliqua (n-120°) con inclinazione variabile da 15° ad oltre 30° che determina uno spessore apparente di oltre 1000 m. le strutture sedimentarie sono essenzialmente di tre tipi e hanno permesso di distinguere tre facies elementari organizzate in sequenze di facies: facies a: caratterizzata da unità centimetriche o decimetriche, planari, gradate e amalgamate con granulometria massima di 3-4 cm, media di 1-2 cm; facies b: caratterizzata da unità decimetriche a stratificazione e laminazione incrociata, localmente ondulata con basso grado di bioturbazione; facies c: caratterizzata da unità stratificate con alto grado di bioturbazione, spesse fino ad alcuni decimetri. le sequenze elementari di facies (es. a-b-c, di spessore variabile, inferiore al metro) sono da attribuire ad eventi di tempesta che indicano l’evoluzione a breve termine del livello del mare in senso “istantaneo”, da pochi secondi a numerosi anni: la facies a, con base erosiva, rappresenta l’acme della tempesta (massima energia), la facies b la fase di trasporto lungocosta (fase di “set up”), la facies c la fase di bassa energia. le sequenze di facies, che si osservano in modo praticamente continuo lungo la linea di costa tra punta penne e il porto di brindisi, indicano una evoluzione a lungo termine, da no verso se, da un ambiente intertidale (sequenze prevalentemente amalgamate a/a) ad un ambiente di spiaggia sommersa (“upper shoreface”) con graduale incremento delle facies c e riduzione delle sequenze ab. l’organizzazione a livello di sequenze a breve termine (ordine metrico) e a lungo termine (decine e centinaia di metri) suggerisce l’ipotesi di uno “spit”costiero caratterizzato da equilibrio tra erosione, trasporto e accumulo in direzione se, secondo i venti dominanti del quadrante nord-occidentale. l’azione del moto ondoso conseguente ai fenomeni di rifrazione, il trasporto lungocosta e la frequenza ed intensità delle tempeste, insieme al costante pendio del profilo costiero, hanno sviluppato una tipica geometria clinoforme a grande scala. il sistema era bilanciato da una subsidenza differenziata, trasversale alla costa, di minore entità nel tratto a n di punta penne, che avrebbe innescato i processi erosivi, ed assicurato lo spazio per l’accumulo maggiore verso se. il corpo sedimentario così formato può essere interpretato come un ciclo di 4° ordine controllato principalmente da fattori allociclici che possono spiegare la continuità laterale e l’efficienza del sistema costiero (rifornimento di sedimento, capacità del trasporto lungocosta, subsidenza). la durata approssimativa potrebbe essere stata attorno ad alcune migliaia di anni in corrispondenza dell’ alto eustatico coincidente con il tirreniano ( m.i.s. 5 e). la riduzione della subsidenza e dell’energia di trasporto delle correnti lungocosta, e la tendenza regressiva generale riconosciuta nella successione studiata sono le probabili cause della terminazione dello spit. key-words: facies analyses, coastal dynamic, palaeobeach reconstruction. parole chiave: analisi di facies, dinamica costiera, ricostruzione di paleospiaggia, pleistocene. 1 tyrrhenian marine deposits are not pointed out, probably due to uplift occurring in the apulian foreland since the middle pleistocene, in contrast with the central adriatic and ionian sea, where subsidence continued from pliocene and early pleistocene (doglioni et al., 1996,ferranti et al., 2006 cum biblio). 2 work financially supported by murst (40% and 60%). il quaternario italian journal of quaternary sciences 23(2), 2010 217-228 218 f. loiacono 1 introduction the coastal change is a topic of great interest for scientists, economists, politicians and land owners. they, in various ways and for different aims, study the rate of coastline shifting in terms of retreat or accumulation. the maps and charts used for coastal zone study have increasingly been improved with advanced technology. therefore we have a good evidence of coastal changes (king, 1972). the reconstructed steps of the coast evolution and trends, through maps, remote sensing and monitoring, point out the effects both of natural processes and of human activity. geomorphologic and sedimentological analyses together with aero-photographs are valuable tools for the reconstruction of ancient coastal environments, developing trends of coastline, erosional retreat rates in relation to wave action, sea level change and geological setting. indeed geometry, shape, sedimentary structures, coastal hydrodynamics, cyclic development of erosion or accretion, reconstruction of growth processes, are all important features both for the knowledge of the past coastline and for the change forecasts. the sea level fluctuations, which occurred in the quaternary times, allowed the building up or pulling down of sand beaches and dunes in different contexts of transgressive or regressive trend. the wave action and coastal currents (direction, intensity), morphodynamic condition (slope angle, exposition of nearshore), grain size, rate of cementation and resistance of cliffs according to geotechnical rock properties are the main control factors. the tectonic activity may be an allocyclic control on the erosion rate and longshore beach migration, particularly when lateral accretion balances tilting. this is the case of coastal spits whose accretion is related to the degree of wave exposure and refraction (evans, 1942; zenkovich, 1967; carter, 2002). the spits are good indicators of net shore drift, coastal erosion and sediment accumulation (taggart and schwartz, 1988); many authors describe these geomorphic structures and their growth mainly due to longshore drift (schwartz, 1984; bird, 1984). many spits are associated with river mouths or estuaries; they show different shapes and sizes (kunte and wagle, 1991). the main topic in the spit interpretation is the factors responsible for origin and growth. the aim of this paper is the description of the stratigraphic context and sedimentologic characteristics of a pleistocene coarse grained body, outcropping along the coast of brindisi town. the reconstruction of the coast dynamics, the growing process and the recognition of the main control factors are also the main objectives of this work. 2 geological setting the italian adriatic coast is a wave dominated microtidal system. the great availability of fluvial sediments, coming from the apennine drainage system, allows the growth of elongated sandy beaches fed by the main south-eastward littoral drift. the southern adriatic coast is poor in fluvial sediments, except for a narrow zone of the ofanto river in the shadow zone of the gargano promontory: the source rocks of sandy beaches are the mesozoic limestones and mostly the quaternary detrital carbonate rocks that cover with different thickness (order of ten meters) the mesozoic substratum. the sea level fluctuations, which happened in the quaternary times, allowed the building up or pulling down of sand beaches and dunes in different contexts of transgressive or regressive trend. the apulian coasts, up to 800 km long from the gargano to the taranto gulf, are differentiated mainly on the basis of tectonic segmentation of the mesozoic carbonate platform during tertiary and quaternary times in three blocks from north to south: gargano, murge and salento (ciaranfi et al., 1992). the structural elements separating the three blocks are normal faults, ne-so directed, that formed two graben-type depressions corresponding to the manfredonia gulf and ofanto valley to the north, and messapic depression elongated between brindisi and taranto to the south (fig.1). both depressions are filled by pliocene and pleistocene sedimentary rocks, composed of calcarenites, mudstones and regressive sands or bioclastic calcarenites, well exposed along the shore or cliff. the thickness and sedimentary features of these units were controlled by the nearness of the mesozoic substratum, its tectonic movements and sea level changes (bosi et al., 1996; hearthy and dai pra, 1992; mastronuzzi and sansò, 2003; ferranti et al., 2006). in the murgian block the plio-pleistocene succession, unconformable on the mesozoic limestones, shows a regional transgressive trend represented by the neritic calcarenites (gravina calcarenites), a sharp upper boundary (maximum flooding surface) and a thick mudstone unit (argille subappennine) interpreted as a shelf system. the overlying regressive sands, mainly dated to middle pleistocene, are overlain by more trasgressive-regressive cycles controlled by eustatic phases (ricchetti, 1972), locally by tectonic movements well recognizable in the marginal areas of the murgian block. the holocene sea level rise produced a drastic coastal erosion and cliff recession (mastronuzzi et al., 1989) mainly where the natural nourishment (fluvial supply) and protection (hard rocks) could not hinder the wave attack. moreover, the coast is increasingly retreated where the thickness of mudstones is great, i.e. in the tectonic depression. this is the case of the messapic trough in the brindisi area. 3 stratigraphy the stratigraphic succession outcropping along the coastal cliff is made up of a thick silty sand unit, lower-middle pleistocene in age (coppa et al., 2001). a calcarenite unit (punta penne calcarenite, ppc; loiacono, 1999; loiacono et al., 2002), not well dated, characterizes the coastal belt at n and s of brindisi. at the top of this unit, di geronimo (1979) recognized a residual upper holocene marine terrace. the calcarenite unit shows a typical clinoform pattern with a maximum dip of about 30° toward se, and a good outcropping continuity (up to three km long) in the northern part of the sedimentary body along the intertidal belt (figs 2, 3) as far as the inlet of brindisi port (fig. 1). beyond the harbour structures the recent marine erosion partially disrupted the sedimentary body and gave rise to minor exposures in islets and reefs (fig.1) for up to 6 km. 219growth process of a long-lived late pleistocene spit along ... fig. 1 a) schematic geological map of adriatic apulian margin in relation to “messapic depression”. 1b) location of the punta penne spit stretching out on the brindisi coast. the present coastal morphology reflects the geometry and the stratigraphic characteristics of the sedimentary body: the sharp boundary in the northern sector (punta penne point), the thinning south-eastward and the consequent erosional coastal retreat which preserved pedagne isles, torre cavallo point, contessa point. 1a) carta geologica schematica del settore adriatico pugliese relativo alla depressione messapica.1b) ubicazione dello spit di punta penne lungo la costa di brindisi. l’attuale morfologia della costa è stata fortemente condizionata dalla geometria e stratigrafia del corpo sedimentario: la terminazione netta a nord, l’assottigliamento verso se hanno determinato un tratto di costa protetto dall’erosione. fig. 2 air view of the northern point of punta penne place showing the even stratification southeastward dipping, the main fracture system according the major axis of the sedimentary body. note the erosional coastal retreat at nw where a normal fault is supposed as starting-point of the spit. – 2a) punta patedda section cropping out along the coast (at w of punta penne area ) in erosional retreat. foto aerea dell’area di punta penne, base della successione dello spit: visibile la stratificazione inclinata verso se secondo l’allungamento del corpo sedimentario. – 2a) sezione schematica dell’affioramento di punta patedda lungo la costa nord-occidentale in erosione. 220 the stratigraphic thickness is about ten meters in the northern edge (from some bore-holes); it thins southeastward where it is possible to observe the lower sharp boundary with the middle pleistocene silty sands (punta contessa section, fig.4). a shell lag, 10 cm thick, characterizes this contact. three km more southward (torre s. gennaro cliff) the recent coastal retreat allows us to observe, along the cliff, the regressive middle pleistocene silty sand unit (coppa et al., 2001). the whole reconstructed geometry corresponds to a nwse elongated body, grown southeastward due to lateral migration of not less than three km, which gave rise to an apparent thickness not less than 1500 m. at the northern boundary, the inclined beds of punta penna calcarenite (upcurrent end) are well exposed along the coastline; the body of the ppc unconformably lie in sharp contact, put in evidence by two still-stand rodolitic layers, with a sub-horizontal succession of middle pleistocene silty sands (punta patedda section, figs. 1b, 2a). fig. 3 typical view of stratification and clinoform pattern of the spit. tipico aspetto della stratificazione uniformemente inclinata a se nel senso dell’accrezione dello spit fig. 4 the contessa section shows the likely expression of the depositional sequence in the landward margin of the southern edging part. it is a condensed section composed of the lower erosional surface, the transgressive lag, the transgressive part of the sequence, the maximum flooding surface and the regressive part of the sequence with lagoonal facies and soil at the top. the regressive trend and the minor effect of the tilting may be the causes of the gradual but fast decrease of migration of the spit. in this sense the stratigraphic and sedimentologic observations carried out in the outcrops of the pedagne isles and in the contessa section may represent the only data useful for a speculative interpretation about the downcurrent-upward (time-space) evolution of the growth process of the spit. sezione di punta della contessa nel settore meridionale del corpo stratigrafico. dalla base: contatto erosivo con strato conchigliare, termine trasgressivo, superficie di massimo approfondimento corrispondente all’intervallo siltoso, termine regressivo con sabbie stratificate di spiaggia e laguna. i caratteri emersi da questa sezione e dagli affioramenti delle isole pedagne suggeriscono l’ipotesi di una terminazione a se dello spit ed un trend trasgressivoregressivo nel suo sviluppo complessivo. f. loiacono 221 4 sedimentology the main sedimentological feature is the stratification and its characteristics at different scales. the 1st order feature is the clinoform pattern (n120°,30°, figs. 2, 3, 5) and the coarse grain-size of the rocks, which are remarkably constant given time. the explanation of these features could be related to a balance between erosion rates, sediment transport and lateral accretion. the 2nd order characteristics of the stratification is the trough cross-bedding landward or seaward-directed, symmetrical and planar bedding, and hummocky cross-bedding in composite beds (figs. 6,7,8,9). it is related to migrating bedforms in the wave transformation zones according to storm or fair-weather conditions, wave energy transmission and response of the shoreline profile, reflective or dissipative, previous to each storm. the 3rd order feature of the stratification is linked to foresets, flat beds, imbrications and alignments of shells or pebbles. these, like 2nd order structures, are palaeoindicators of flows and palaeoenvironments. 4.1-elementary facies (ef) three ef are distinguished on the basis of textural features and sedimentary structures; each facies refers to a clear depositional mechanism in a short-term evolution. facies a: coarse or very coarse sands (0 to –1 phi mean size) with scattered pebbles or shells in fragment or whole, unsorted or well sorted for the mean size; negative skewed. the lower contact is always erosional, whereas the upper boundary moves quickly towards facies b or c. in composite beds the facies a is repeated in amalgamated graded beds (fig.5). this facies is interpreted as the product of a high energy event. facies b: medium to coarse fig. 5 – punta penne outcrop in the lower part of the succession. facies a: normal grading is well visible both in the single bed (elementary sequence) and in the bedset (long-term evolution). intervallo stratigrafico inferiore, affioramento di punta penne (sezione nw-se). gradazione evidente sia a scala di singoli strati (sequenze elementari, eventi di tempesta), sia a scala di strati amalgamati (evoluzione a lungo termine). fig. 6 – amalgamated sequences in the 1st stratigraphic interval. from the bottom: facies b in a thick bed (trough cross bedding, locally hummocky, foreset migrating landward, on the right) interpreted a rip channel or a large swale cut at the top by a flat erosional surface (middle part of the photo); facies a (very coarse sand, plane bedding), evolving to thin beds of facies b (low angle cross bedding, locally bioturbated) referred to a new elementary sequence. sequenze amalgamate nel 1° intervallo stratigrafico. dal basso: facies b, sabbia medio-grossolana a stratificazione concava con foreset migranti verso terra (a destra) interpretata come riempimento di un canale di risucchio connesso ad un evento di tempesta. la superficie piana erosiva sovrastante è riferibile ad un nuovo evento; facies a (sabbia molto grossolana a stratificazione piana passante verso l’alto a strati sottili della facies b (stratificazione incrociata a basso angolo). growth process of a long-lived late pleistocene spit along ... 222 sands, overlying facies a or a thin horizon of coarse sands, organized in planar or trough cross laminations, in gently seaward or landward dipping lamina-sets. the thickness of these beds is variable in relation to the wave energy dissipation of storm events and to morphology and slope of the beach . some sets show a migration of shallow runnels (fig. 6). others show high-angle cross-bedded units dipping toward land and are interpreted as locally preserved intertidal bars truncated upward by future storm events (fig. 8). locally at the top of facies a a smallcurrent ripple interval and some bioturbations sets are preserved under the next erosional surface. in this case (fig. 7) the facies c is drawn between brackets. facies c: coarse to fine grained bioturbated beds, up to 50 cm thick. the coarse sands and the sharp contacts of c beds with the tractive b beds suggest a fast process of colonization and reworking in the fig. 7 – sequence a-b(c)b in the 1st stratigraphic interval: in the middle part of the photo rapid evolution from facies a (very coarse sand in plane bedding) to facies b with coarse-middle sand in trough cross bedding; foreset inclined both landward and seaward. sequenza di facies a-b con sottili orizzonti bioturbati alternati alla facies b. nella parte centrale della foto è visibile il rapido passaggio dalla facies a (sabbia molto grossolana con ciottoli) alla facies b (sabbia media a stratificazione incrociata con locale bioturbazione). verso l'alto stratificazione a basso angolo con foreset inclinati sia verso terra (a destra) che verso mare (a sinistra). fig. 8 – amalgamated elementary storm sequences in the 1st stratigraphic interval, composed of a lower coarse interval (facies a, plane bedding) passing upward to thin cross beds (facies b). the thick bed with foreset inclined landward (to the right) is interpreted as an intertidal bar. in the upper part of the photo the erosive surface, inclined seaward (on the left) indicates a new storm sequence with well rounded subspherical pebbles or inclined toward sea. sequenze di tempesta elementari amalgamate con facies a (intervallo inferiore grossolano con stratificazione piana) passante a stratificazione obliqua (facies b). lo strato lenticolare con foreset inclinati a destra (verso terra) è interpretabile come barra intertidale, limitata, nella parte superiore della foto, da una superficie erosiva che indica un nuovo evento di tempesta. f. loiacono beach ridge (lower foreshore), probably already in the last phase of the storm action. the trace-fossils are bichordites-like indicating high shifting of sediment and normally shallow waters (a. d’alessandro, pers. communication). the bioturbated beds are well stratified (figs.10,11): the surfaces may be the results of storm events along the base of the slope in the transition foreshore-shoreface. inside these beds locally thin discontinuous laminated sets are preserved, giving evidence of tractive current (fig. 11). in this case the facies b is drawn between brackets. joined compositional analysis allows us to define grainstones (according to dunham classification, 1962) the well-sorted beds mainly composed of well rounded skeletal grains up to 1-2 mm in diameter (facies b), and rudstones the unsorted beds composed of heterometric grains and pebbles up to 5 cm in diameter, mainly carbonate extraclasts, only locally imbricated (facies a, fig.8). the bioclastic grains, dominant in all facies, are mainly fragments of bivalves, gastropods, echinoids, serpulids and crustaceans, red algal balls, bryozoans. a great number of benthic foraminifers are present in whole specimens. 4.2-facies sequences many sedimentologic logs are studied, observing facies sequences in terms of variations in textures, sedimentary structures and biogenic features, and relating them to nearshore sub-environments in terms of flow regime, expression of change in wave energy, seaward or landward accretion. the observations were made along the coast (fig.2) where the exposure of the beds allow us to obtain many data mostly on the progradation or frontal migration, partially on the seaor landward lateral variations. for this reason in the following sections the facies descriptions will be made following the dip direction (southeastward) and, if possible, the lateral variations seaward (ne) or landward (sw). in the lowermost stratigraphic interval (punta penne outcrop, figs. 1,2) trough cross bedded and bioturbated thin intervals are the distinctive features (fig. 9) of a lower tractive regime subenvironment, probably located landward (sw). the festoon axes are scattered in 85°-117° directions. the dip is 10° to se. in the eastern part (seaward) the typical vertical sequence, dipping 25-30° to se, is composed of a coarse-grained bed, 30-50 cm thick (facies a), overlying, with an erosional contact, a bioturbated interval (facies c) and passing upward to thick cross bedded interval (characterized by lamina-sets directed landward or seaward going from land to sea in the outcrop, figs.7,8,9). locally these beds are convex upward, hummocky type. 223 fig. 9 – punta penne outcrop (1st interval); ne-sw oriented section, land at right. facies b composed by megaripples migrating southeastward, locally bioturbated. affioramento di punta penne (1° intervallo); sezione ne-sw, lato verso terra a destra. facies b a megaripple migranti verso se, parzialmente bioturbati. fig. 10 – facies c in the 2nd stratigraphic interval (middle-upper part of the succession). the bioturbated beds are separated by thin laminated beds (planar or low angle) in which single trails bichordites-like are present. intervallo spesso della facies c nel 2° intervallo stratigrafico (punta serrone). i sottili strati laminati, piani o a basso angolo, sono localmente attraversati da tracce tipo bichordites. growth process of a long-lived late pleistocene spit along ... 4.3-short-time evolution a facies sequence may be the product of an accretion cycle storm-controlled in foreshore-shoreface subenvironment. the coarse bed is the product of the acme of the storm in the breaker zone (probably plunging type); in this set up phase the beach face was affected by high wave energy, transport of a great amount of coarse material according to the slope ( seaward or landward of the foreshore, fig. 6). during the normal sea level restoring the fast colonization of the benthic fauna may have reworked both the coarse sediment of the rip currents and the bedforms, specially the landward flank of the bar. each sequence of this type is referred to short time beach evolution, that is in an “instantaneous” sense, from a few seconds to several years. the sedimentary product is a facies sequence of different thickness, from a few centimetres up to one metre: grading, tractive structures and bioturbated intervals can record the complete evolution of a storm event. the amalgamated beds of facies a (fig. 5) record truncated sequences, where the full spectrum of variation is not present. these sequences may be referred to the frontal part of the accretional body. 4.4-long-term coastal development long-term changes in beach evolution are due to storm regime, sea level short fluctuations and shoreline morphological changes that produce different wave actions. in this sense thick or very thick sequences (several metres or more) may be interpreted. the sedimentologic features which are more sensitive to change, in the studied succession, are the thickness of facies a beds, the ratio between physical and organic structures: r= (a+b)/c. a weak decrease in the grain size and in the thickness of the beds couples with the increase in bioturbation. the lowermost stratigraphic interval (1st in fig.1), up to 1 km along shore, is characterized by r >1. a recognizable increasing in bioturbation is located after 1 km of the continuous succession (punta serrone): for 0,5 km the stratification is characterized by r =1 (2nd interval, fig. 1). along shore the bioturbated beds increase and the overlying succession (3rd interval) is composed of an alternance of packets (fig.10) with r=1 or r<1 (thickness of some tens of meters to some hundreds of meters). long term cyclicity suggests a decreasing sediment supply or a slowing-down beach migration, due to climate improvement and/or to a decrease in longshore current power (change in wave angle approach), or to a minor effect of tilting versus sea-level rise. 5 results stratigraphic remarks: • the punta penne calcarenite (ppc) is a coarse sedimentary body inclined and thinning toward se in pleistocene fine grained marine sediments; • the lower boundary, in the northern side, is an unconformity (figs. 2, 2a); • it is characterized (in the condensed contessa section, up to 4 m thick) by transgressive lag with pebbles and shells, a transgressive unit and an upper regressive unit. • the real thickness of the sedimentary body is about ten metres. the lateral accretion of the 3 km long body, about 30°dip, formed a succession about 1500 m thick (apparent or pseudo-stratification, figs. 2, 3). • it was generated by a lateral accretionary process controlled by a long balance between vigorous wave attack and longshore current southeastward, reworking of coarse bioclastic sand in beach environments (foreshore-upper shoreface). facies analyses: • the facies analysis suggests elementary sequences, 224 fig. 11 – stratigraphic evolution from 2nd to 3rd interval (outcrop near the airport, along the coast, see fig. 1). in the lower part of the photo facies b are dominant (trough cross bedding with scattered trails). in the upper part the bioturbated beds are continuous and contain thin laminated preserved horizons. it may suggest a deepening and rapid decrease of the migration rate. evoluzione delle sequenze di facies nella parte superiore della successione (affioramento aeroporto di brindisi, fig.1). in basso nella foto si osservano spessi strati della facies b (stratificazione incrociata concava) con tracce fossili isolate. verso l’alto è visibile un netto incremento della facies c in strati regolarmente continui caratterizzati internamente da sottili livelli laminati preservati. ciò può indicare una tendenza all’approfondimento e/o alla riduzione dell’accrezione dello spit. f. loiacono or compound beds, various thickness, characterized by: 1 graded, amalgamated (few cm to some dm thick) planar units with lower erosional surface (facies a); 2 cross-bedded units, some dm thick (facies b); 3 bioturbated units, few to 5 dm thick (facies c). facies sequences: • each sequence is referred to short-time beach evolution (storm event) developed into: acme phase during the risen sea (set-up, highest energy, main plunging breakers, facies a), longshore transport phase (facies b), low energy phase (facies c). • the stacking pattern of the facies sequences in the whole outcropping area (about 3 km from punta penne to brindisi harbour) indicates the long-time evolution of the beach under the main control factors: subsidence, power of the wave attack and reworking, minor sea level fluctuations. • some stratigraphic intervals are distinguished on the basis of facies ratio r=(a+b)/c (fig.1b). high r indicates a good balance between accumulation and lateral accretion, whereas the decrease in the ratio may suggest the decrease of sediment supply, the slowing down migration and relative deepening. the first interval (0-1,0 km along the coast, 500 m thick ) is characterized by r>1 (fig. 5). the second interval is composed by a thin interval (10-20 m ) characterized by r > or = 1 (fig. 7) followed by an interval, about 250 m thick, characterized by r>1. this is overlain by a third interval with r<1 (fig. 10), gradually passing to packets, variously thick, with r ≥1. in this part of the succession (3rd interval, fig. 1b) the gradual increasing of the facies b in the thick beds of facies c is very frequent. evolution down-current the southeastward part of the calcarenitic body outcrops discontinuously in many little isles and reefs in the brindisi harbour (4th interval, fig.1, 12). moreover the contessa section (fig. 4) may be interpreted as the southeastward expression of the punta penne depositional sequence in landward margin, as appeared after the drastic holocene coastal recession (5th interval, fig.1). downcurrent the accretion dies away and the sequence becomes sub-horizontal (contessa section, fig. 4); southeastward it intercalates in middle pleistocene regressive succession (campo di mare section, coppa et al., 2001). 225 fig. 12 facies characteristics of ppc in pedagne isles (4th stratigraphic interval, fig.1 for location): the main sedimentary structures are trough cross bedding, locally hummocky. the dip is variable toward wnw and ne, indicating a probable shrinkage of the spit, or a different development (?regressive trend) in the upper part of the succession. the lack of facies a and dominance of facies b suggest an upper shoreface environment. caratteri di facies nell’affioramento delle isole pedagne (intervallo stratigrafico 4 fig.1). e’ prevalente la stratificazione incrociata localmente ad “hummocky”. l’inclinazione dei foreset indica migrazione variabile da wnw a ne in piccoli tratti, probabilmente connessa ad un restringimento della parte frontale dello spit durante la fase finale del suo sviluppo (probabile fase regressiva in ambiente di spiaggia sommersa superiore). growth process of a long-lived late pleistocene spit along ... 6 conclusion the detailed study of the ppc succession outcropping along the brindisi coast allows for the reconstruction of the genetic and growth processes, the likely control factors: uplift in the northern side of the coast, erosion rate, subsidence in the nearshore, longshore transport and accumulation. possible influences on the ppc cycle. in the general regressive trend of the late pleistocene, the ppc cycle may be caused by a significative uplift in the northern area (punta patedda section) as well as by an amount of subsidence in the coastline southward. the increase in the erosion and sediment supply on the coastline were balanced by the accommodation space in the southern part (relative sinking). a detrital progradation developed a southeastward migrating spit. in the dynamic process of the coastal cell, the fluid power (wave refraction and longshore transport of coarse sediment) and the inclined surface along the shoreline developed a typical clinoform pattern. the dynamic equilibrium was controlled by the stratigraphic process variables: the relationships of the rate of sediment input (q) with fluid power (p), able to remove it, was important in the sedimentary body growth. over a short period of time every prograding sedimentary unit shifted seaward and formed the next inclined surface, dominated by the same hydraulic condition. over a long time the change of one or more geohistorical variables (swift and thorne, 1991) fixed a new equilibrium in the depositional regime. particularly the decrease in sediment input (erosion or longshore transport) reduced the progradation and caused an aggrading phase and increasing bioturbation (facies c). climate fluctuations seem to well explain sedimentary facies rate changes [(a+b)/c]. finally the ppc cycle may be interpreted as a 4th order cycle, mainly controlled by allocyclic processes on account of its lateral continuity. an approximate accumulation of the spit could be limited to a few thousand years, probably during late pleistocene. the origin of this cycle was most likely the eustoclimatic variation, as an efficient rule in coastal domain. the sequence boundary (fig.13) is interpreted as a differential uplifting, at a higher rate on the northern side – thus favouring a headland erosion decreasing towards the southern side, where the subsidence produced accommodation space for nearshore sedimentation. sediment supply, efficiency of longshore drift and subsidence all controlled the growth process and lateral migration of the spit. the close up of subsidence and the regional regression caused the spit death. the morphologic consequences on the recent coast evolution are: the coarse and well cemented rocks of ppc make up a natural shelter for the brindisi coast and its port (fig.1); the southeastern thinning reduces this natural shelter and produces the erosional retreat. acknowledgements the work was supported by a grant of “ricerca ateneo” bari university and carried out in collaboration with the technical staff of the 2nd scienze department m.f.n. – taranto (particularly cosimo magrì). two anonymous referees are greatly acknowledged for useful comments and suggestions. references bosi c., carobene l. & sposato a. (1996) il ruolo dell’eustatismo nella evoluzione geologica nell’area mediterranea. mem. soc. geol. it., 51, pp. 363382. 226 fig. 13 cross section of the punta penne spit system parallel to the main transport direction (fig. 1b). a hypothetical fault controlled the arisen sediment supply at nw and the subsidence at se where the accommodation space and the efficient transport of longshore currents favoured the growth and preservation of the sedimentary body. see map for locations. modello di sviluppo dello spit in una sezione parallela alla costa (fig.1b). una faglia ipotetica ubicata a nw (tra p.penne e punta patedda) avrebbe determinato a nord il sollevamento del tratto di costa creando una zona in erosione, e a sud una zona in subsidenza dove si sarebbe indirizzato il materiale eroso secondo il trasporto lungocosta. il sistema costiero, cella di tipo spit, sarebbe stato controllato, pertanto, da fattori allociclici (tettonica, clima meteomarino, minori variazioni del livello marino) e da fattori autociclici (sedimentazione di detrito grossolano, morfologia della costa e rifrazione del moto ondoso). f. loiacono carter r.w.g. (2002) coastal environments. pp. 617. academic press. london. ciaranfi n., pieri p. & ricchetti g. (1992) note alla carta geologica delle murge e del salento (puglia centro-meridionale). mem. soc. geol. it., 41 (1988), pp. 449-460. coppa m.g., de castro p., marino m., rosso a., sanfilippo r. (2001) the pleistocene with aequipecten opercularis (linneo) of “campo di mare” (brindisi, italy). boll. soc. paleont. ital., 40 (3); 405-429. di geronimo i. (1979) la malacofauna di punta penne (brindisi). boll. malacologico, 14 (3-4), pp. 41-45. doglioni c., mongelli f. & pieri p. (1994) the puglia uplift (se italy) : an anomaly in the foreland of the apenninic subduction due to buckling of thick continental litosfere. tectonics, 13(v), 1309-1321. dunham r.j. (1962) classification of carbonate rocks according to depositional texture in ham, w.e. (ed.), classification of carbonate rocks, a.a.p.g. memoir, 1, 108-121. evans o. f. (1942) the origin of spits, bars and related structures. in: m.l. schwartz (ed.), spits and bars. dowden, hutchinson & ross inc., pp. 52-72. ferranti l., antonioli f., mauz b., amorosi a., dai pra g., mastronuzzi g., monaco c., orru p., pappalardo m., radtke u., renda p., romano p., sansò p., & verrubbi v. (2006) markers of the last interglacial sea-level high stand along the coast of italy: tectonic implications. quaternary international 145-146 (2006) pp.30-54. hearthy p.j. & dai pra g. (1992) the age and stratigraphy of middle pleistocene and younger deposits along the gulf of taranto (southern italy). journal of coastal research, 8, pp.882-903. king c.a.m. (1972) beaches and coasts (2nd ed.). arnold, london. kunte p. d. and wagle b. g. (1991) spit evolution giornale di geologia, 53, 2, pp. 71-80. loiacono f. (1999) le calcareniti di punta penne. in: guide geologiche regionali – puglia e monte vulture, pp. 273-274. società geologica italiana. be-ma ed. loiacono f., magrì c. & monaco m.t. (2002) il litorale di brindisi: uno spettacolare parco di strutture di una spiaggia fossile . atti del convegno “conservazione e valorizzazione del patrimonio geologico”. geologia dell’ambiente, sigea. suppl. n.1/2003, pp.143-150. mastronuzzi g. & sansò p. (eds.) (2003) quaternary coastal morphology and sea level change. field guide, puglia 2003, final conference – project igcp 437 unesco – iugs, ricchetti g. (1972) osservazioni geologiche e morfologiche preliminari sui depositi quaternari affioranti nel f° 203 “brindisi”. boll. soc. naturalisti in napoli. schwartz m.l. (1984) spits and bars. dowden, hutchinson & ross inc. swift d.j.p. & thorne j.a. (1991) sedimentation on continental margins, i: a general model for shelf sedimentation. in: shelf sand and sandstone bodies: geometry, facies and sequence stratigraphy (ed. by d.j.p. swift, g.f. oertel, r.w. tillman and j.a. thorne), pp. 3-31. spec. publ. int. ass. sedim., 14. zenkovich v.p. (1967) in process of coastal development (steers j.a. eds), pp. 383-493. 227 ms. ricevuto il 18 novembre 2008 testo definitivo ricevuto il 12 agosto 2010 ms. received: november 18, 2008 final text received: august 12, 2010 growth process of a long-lived late pleistocene spit along ... biochronology of terrestrial mammals and quaternary subdivisions: a case study of large mammals from the italian peninsula maria rita palombo dipartimento scienze della terra università la sapienza, cnr, istituto di geologia ambientale e geoingegneria, p.le aldo moro, 5 00185 roma, italy. e-mail: mariarita.palombo@uniroma1.it abstract: palombo m.r., biochronology of terrestrial mammals and quaternary subdivisions: a case study of large mammals from the italian peninsula (it issn 0394-3356, 2009). defining and subdividing the quaternary on the basis of the mammalian fossil record from the continental realm is not a simple task due to the low degree of succession continuity and the scattered palaeontological evidence. moreover, even if the approaches to the quaternary are basically interdisciplinary and may combine many different chronological scales, establishing correlations between biochronology, biostratigraphy, chronostratigraphy, climatostratigraphy, and composite regional stratigraphy can often be very problematical. as far as biochronology is concerned, the marked geological, environmental and climatic diversity affecting different continental regions makes a correlation based on biological events difficult. indeed, “biochronological units” represent a time span during which faunas have a degree of taxonomic homogeneity and the corresponding “faunal complexes” have to be regarded as nonoverlapping and "ecologically adjusted groups of animals with specific geographic limits and chronological range" (te d f o r d, 1970). nevertheless, the stratigraphic lowest and highest occurrences of fossil remains (stratigraphic datum) within a given geographical area do not necessarily correspond to their actual first/last appearances (palaeobiological events) in time. this is due to diachroneity in palaeobiological events (i.e. local first and last appearances are strictly linked to dispersal, and the physical and biotic factors causing local evolution and extinctions) coupled with discontinuity in the continental sedimentary record, the rarity of deposits formed in a regime of virtually continuous sedimentation, the presence of important ecological barriers (that prevent some taxa from dispersing), environmental conditions (that affect the structure of palaeocommunities), and taphonomic and sampling biases. as a result, ongoing research, continuously yielding new data, make chronological frameworks thus far outlined, even if recent, open to significant improvements, and causing biochrons to be updated. this fact prevents any detailed biochronological framework from having widespread geographical significance. thus, only higher ranking biochronological units (land mammal ages, lmas) whose separation is based on palaeobiological events which have a wide territorial significance could be useful for chronological correlations. nonetheless, the transition between successive lmas does not always correspond to the boundaries separating marine series or stages. for instance, the villafranchian lma approximately began with the late pliocene (piacentian) and the transition from the early to the middle villafranchian lma happened around the pliocene/pleistocene (piacentian/gelasian) boundary, whereas the transition to the late villafranchian took place during the latest gelasian, and those from the villafranchian to galerian lma and from the galerian to aurelian lma respectively predated the beginning of the middle and late pleistocene. riassunto: palombo m.r., biocronologia dei mammiferi terrestri e suddivisioni del quaternario: l’esempio della faune a grandi mammiferi della penisola italiana. (it issn 0394-3356, 2009). definire e suddividere il quaternario sulla base del record fossile dei mammiferi continentali non è un compito facile ed anche se gli approcci al quaternario sono fondamentalmente interdisciplinari e tendono a combinare diverse scale cronologiche, stabilire correlazioni tra biocronologia, biostratigrafia, cronostratigrafia, climatostratigrafia, e stratigrafia regionale è spesso problematico. sebbene le unità basate su eventi biologici e climatici siano di largo uso nel quaternario continentale, il loro status non è stato formalmente definito e questo alimenta dubbi nell’approccio metodologico e confusione tra teoria (dato paleobiologico) ed operatività (dato stratigrafico). dal punto di vista teorico, le " unità biochronologiche" rappresentano un lasso di tempo durante il quale le faune locali hanno un certo grado di omogeneità tassonomica ed i "complessi faunistici” che caratterizzano le singole unità devono essere considerati “non-overlapping and ecologically adjusted groups of animals with specific geographic limits and chronological range" (tedford, 1970). tuttavia, l'’evidenza stratigrafica della prima e ultima presenza di un fossile nelle successioni affioranti in una determinata area geografica (dato stratigrafico) non corrisponde necessariamente all’effettiva prima e ultima comparsa di quel taxon nel tempo (evento paleobiologico). ciò si deve alla diacronicità degli eventi paleobiologici (ad esempio gli eventi locali di comparsa e scomparsa sono strettamente legati rispettivamente alla dispersione ed ai fattori fisici e biotici che regolano diffusione ed estinzione), alla discontinuità del record sedimentario continentale, alla rarità di depositi formati in regime di sedimentazione continua, alla presenza di barriere ecologiche (che limita o impedisce la dispersione di alcuni taxa in certuni territori), alle condizioni ambientali locali (che influenzano la struttura delle paleocomunita), a problemi tafonomici e di campionamento. questi limiti rendono instabili schemi biocronologici dettagliati basati su un record fossile regionale, in quanto essi sono fortemente dipendenti dal progredire delle conoscenze sul campo. fin dalla prima introduzione delle unità faunistiche (fus) (azzaroli 1977), sulle quale si fonda la biocronologia dei grandi mammiferi della penisola italiana, il progredire delle ricerche e la scoperta di nuove faune ha portato sia alla ridifinizione e/o eliminazionedi alcune fus sia alla creazione di nuove. ne consegue che, proprio in funzione della possibilità di discriminare singoli bioeventi, ogni schema biocronologico delle faune italiane risulta quanto più dettagliato tanto meno stabile nel tempo, nonché difficilmente confrontabile con gli schemi proposti per l’europa continentale. in realtà, l’utilizzo di unità biochronologiche di più alto rango (land mammal age, lma) la cui separazione è basata su eventi paleobiologici validi a grande scala e cambi di struttura dei complessi faunistici – meglio si presta a correlazioni su vasta scala. la transizione tra successive lma, tuttavia, non sempre corrisponde ai limiti che separano serie e stadi. per esempio, il villafranchiano inizia con il pliocene superiore (piacenziano), la transizione al villafranchiano medio potrebbe coincidere grosso modo con il limite pliocene/pleistocene (piacenziano / gelasiano), ma il passaggio al villafranchiano superiore avviene nel tardo gelasiano, e le transizioni villafranchiano/galeriano e galeriano/aureliano precedono, rispettivamente, l'inizio del pleistocene medio e superiore. key words: biochronology, biostratigraphy, plio-pleistocene, large mammals, itay. parole chiave: biocronologia, biostratigrafia, plio-pleistocene, grandi mammiferi, italia. il quaternario italian journal of quaternary sciences 22(2), 2009 291-306 292 m.r. palombo 1. introduction defining and subdividing the quaternary on the basis of the mammalian fossil record from the continental realm is not a simple task due to the low degree of succession continuity and the scattered palaeontological evidence. moreover, even if the approaches to the quaternary are basically interdisciplinary and can combine many different chronological scales, establishing correlations between biochronological, chronostratigraphical, climatostratigraphical frames and composite regional stratigraphy can be problematical (concerning italy, see e.g. de gi u l i et al., 1983; ra v a z z i, 2003; pa l o m b o, 2004a; pa l o m b o & sa r d e l l a, 2007 and references therein). with regard to terrestrial fauna, especially mammals, diachroneity in palaeobiological events coupled with discontinuity in the continental sedimentary record, the rarity of deposits formed in a regime of virtually continuous sedimentation, the presence of important ecological barriers (that prevent some taxa from dispersing), environmental conditions (that affect the structure of palaeocommunities), and taphonomical and sampling biases make the definition of isochronous boundaries, maybe of boundaries themselves, problematical. therefore, any biochronological framework is predisposed to change depending on new discoveries. during the latter half of the last century, study on the terrestrial mammals of the italian peninsula was developed mainly on the basis of large-sized mammalian taxa. the italian mammal biochronological framework builds on the pioneering work of azzaroli (azzaroli, 1977, 1982), who first introduced the “faunal units”(fu’s) as “biochrons”, defined on the basis of all the species from selected local faunal assemblages (lfa’s). like land mammal ages (lmas) which are the primary unit of north american vertebrate chronology (see teaford,1970; lindsay & tedford, 1990), fu’s represent and are defined by typical associations of mammalian taxa (biological entities), each living in non-overlapping slices of time. as suggested by lindsay (2003, pg. 222) for lma’s, fu’s could be defined as “a relatively short interval of geological time that can be recognized and distinguished from earlier and later such units (in a given region or province) by a characteristic assemblage of mammals”. although sometimes criticised (e.g. guerin, 1982, 1990), fu’s are general concepts, especially used by the italian scientific community. since the time of the fu’s introduction, italian palaeontologists have proposed new or revised some fu’s/lma’s (see e.g. de giuli, et al. 1983, torre, 1987; az z a r o l i et al., 1988; sa l a, et al., 1992; to r r e, et al. 1992; caloi & palombo, 1990, 1996; gliozzi et al., 1997, pe t r o n i o & sa r d e l l a, 1999; pa l o m b o et al., 2004; palombo, 2004a, 2007a; masini & sala, 2007; petronio et al ., .2007) (table 1). the introduction of new biochrons mainly depends on acquiring new data and discovering new fossiliferous assemblages, which makes possible, by means of ever more detailed biostratigraphical settings, increasingly accurate discrimination between bioevents. this paper’s aim is to outline the pricipal problems related to biostratigraphy/biochronology of large ita lian mammals, and to update the previous biochronological schemes according to the most recent discoveries (table 2.3). 2. about chronostratigraphy, biochronology, biostratigraphy and related items: a short sketch as stated by lindsay (2003) chronostratigraphy the dominant method applied in the oceanographicmarine realm and biochronology the dominant method for the terrestrial realm are the prime conceptual methods for relating biological events to the geological time scale. the chronostratigraphical concept was introduced by schenck & muller (1941), who proposed a new ‘‘chronostratigraphical ’’ hierarchy (system, series, and stage) for the stratigraphical representation of equivalent chronological intervals (period, epoch, and age). recently, lindsay (2003, pg. 227) defined chronostratigraphy as: “the sequential ordering of geologic events, using biostratigraphic, isotopic-radiometric, and paleomagnetic data”. the concept of biochronology dates back the beginning of the 20th century, when wi l l i a m s (1901) defined a “biochron” as the absolute time extent of a peculiar faunal or vegetal association. later, te i c h e r t ( 1 9 5 8 ) described biochronology as ‘‘the dating of geological events by biostratigraphical methods’’, but did not characterise biochronological terms, such as ‘‘biochronological unit’’, and concepts relative to the biostratigraphical ones. due to that loose definition and to its ambiguous application, biochronology has never been discussed in any stratigraphical code (li n d s a y, 2003). up to the present day, the operation of organisi n g geological time on the basis of evidence provided by continental mammal faunas has continued to be a field plagued by interpretative and semantic confusion. be r g g r e n & va n co u v e r i n g (1978, pag. 39) tried to avoid ambiguity defining biochronology as ‘‘the organization of geological time according to the irreversible process of evolution in the organic continuum’’. subsequently, li n d s a y (2003, pag. 227) def ined biochronology as the “sequential ordering of biologic (and geologic) events, using morphologic differences that result from organic evolution (when applied to earth history)”. on the other hand, it is widely known that the discipline of biostratigraphy establishes the stratigraphical ranges of the taxa remains within superimposed sections, and verifies the relative age of rocks using the fossil data. biostratigraphy is the element of stratigraphy which focuses on “the distribution of fossils in the stratigraphical record and the organization of strata into units on the basis of their contained fossils” (sa l v a d o r, 1994, pag.55). but as claimed by sa l v a d o r (1994, pag.55) biostratigraphical units, including biozones, “vary greatly in thickness and geographic extent. ......the time they represent may likewise vary widely”. to avoid this issue, wa l s h (1998) defined the biochronostratigraphical units as “the sets of rock formed during biochrons, without reference to any particular stratigraphic section”. as a result, a biochronological unit should be characterised and defined as a span of time defined by biological evidences (palaeobiological datum), while a biostratigraphical unit as a body of rock strata defined by its fossil content (stratigraphical datum) (sc h o c h, 1989; sa l v a d o r, 1994). 293biochronology of terrestrial mammals and quaternary subdivisions: ... 294 2.1. in search of a stable biochronological frame for the terrestrial large mammals: utopia or feasible undertaking? as defined above, “biochronological units” represent a time span during which faunas are assumed to be characterised by taxonomical homogeneity and should be regarded as nonoverlapping and an “ecologically adjusted group of animals within specific geographic limits and chronologic range” (tedford, 1970). first/last appearance bioevents (palaeobiological events on which biochronology is based) have been the principal bases for establishing the chronological setting of continental mammalian faunas. however, the marked geological, environmental and climatic diversity affecting different continental regions, as well as the discontinuity in the continental sedimentary record, the rarity of deposits formed in a regime of virtually continuous sedimentation, the diachroneity in palaeobiological events (i.e. local first and last appearances are strictly linked respectively to dispersal, and the physical and biotical factors causing extinctions), taphonomical and sampling biases are responsible for the fact that the stratigraphical order of the highest and lowest occurrences (stratigraphical datum) of fossil remains of some taxa within a given geographical area, does not necessarily reflect the temporal order of the actual first/last appearances (palaeobiological events) of each taxon in time. indeed, a stratigraphical discontinuity within a sedimentary succession (whether due to erosional phases or sedimentation lacking) corresponds to a time span during which palaeobiological events do not yield a stratigraphical record. moreover, fossil remains of taxa characterising a given biochronological unit do not necessarily appear in each section because they were absent from the depositional environment for ecological or taphonomical factors. therefore, the time range of a paleobiological entity (either in general or in a given geographical area) cannot be unquestionably established by its fossil evidence. the lowest and highest stratigraphical records of a taxon, respectively correspond to the time “ante” or “post quem” when it actually originated and became extinct (pa l o m b o 2004a). accordingly, it should be appropriate to discriminate taxon longevity from time slice of its fossil record, e.g. first/last historical appearance bioevents (fha/lha = first/last historical appearance) from “known data” of lowest and highest occurrences in a local stratigraphical section (llsdk/hlsdk = local lowest/highest known stratigraphical datum) (wa l s h, 1998; pa l o m b o & sa r d e l l a, 2007). on the other hand, mammalian biochronology is actually founded on fossil records available in the continental rocks, fha/lha bioevents can only be inferred from the lowest/highest occurrences of fossil remains in fossiliferous levels, maybe based on more than one continental stratigraphical section. hence, new discoveries may substantially change the chronological extent of already defined biochrons. indeed, the finding of a/some taxon/a (whose lha/lha were already regarded as markers of a biochrons) in significantly older/younger extends the theoretical time range of such a biochron, without changing its theoretical definition. as a result, ongoing research, continuously providing new data, makes chronological frameworks thus far outlined, even if recent, open to significant improvements. some biochrons, consequently, will require revisions and updated definitions. 3. faunal turnovers, biochrons and quaternary subdivisions during the pliocene and pleistocene a series of climatic cycles caused latitudinal displacements of vegetation and biomes in europe and exerted great influence on dispersal and dispersion of mammalian species. as a result, the composition of regional faunas changed because of origination/ extinction and dispersal bioevents. on the italian peninsula, climatic changes were a driving factor, at least as far as the two most important detectable faunal renewals are concerned: the early to middle vil lafranchian lma (piacentian to gelasian, ~2.7–2.5 ma) and early to middle galerian lma, transit ion ( latest early pleistocene, ~1.1–0.8 ma). faunas changed also at the end of the gelasian (middle to late villafranchian transit ion) and at the end of the middle pleistocene (galerian to aurelian transition), but to a lesser degree (palombo, 2007b and references therein). 3.1 the beginning of the villafranchian and the warning signs of the already called “glacial pliocene” the list of early villafranchian taxa have been established on a number of lfa’s from piedmont (several localities in the villafranca d’asti area) and central italy (e.g. lower and upper valdarno, arcille, spoleto). palaeomagnetic data at fornace r.d.b. (villafranca d’asti) (lindsay et al., 1980, 1995) as well paleomagnetic calibration of the long sedimentary sequence outcropping at santa barbara quarry (lignitic lacustrine silty clays and sands, meleto clays of castelnuovo dei sabbioni lower synthem of the upper valdarno basin) (torre et al., 1996; bertini & roion, 1997; napoleone et al., 2003; ghinassi et al., 2004) illustrate that, at about 3.2 ma, the faunal association regarded as typical of the early villafranchian was already present on the italian peninsula. the early villafranchian lma (triversa fu) retains subtropical affinities typical of ruscinian mammals, which lived during the early pliocene, the most recent interval with a climate definitively warmer than today. pachyderms, middle sized artiodactyla, and perrissodactyla, mainly browsers or mixed-feeders inhabiting dense or clear forest, were still present along with arboreal/scansorial viverrids and arboreal omnivores, such as mesopithecus monspessulanus, parailurus hungaricus and ursus minimus. on the other hand, the appearance of some taxa, such as leptobos s t e n o m e t o p o n and stephanorhinus jeanvireti (= stephanorhinus elatus) (table 3), perhaps more linked to wooded parkland environment, testified to a change in faunal structure which can be correlated with the climatic cooling, which occurred at about 3.2/3.1 (km2 isotopic stage) (table 2). 3.2 early to middle villafranchian and the piacentian to gelasian transition the following montopoli fu is based on rich fauna from a site near montopoli (lower valdarno, tuscany), m.r. palombo 295 table 2 integrated chronological scheme for the middle pliocene to late pleistocene large mammalian record of the italian peninsula. biochronology of terrestrial mammals and quaternary subdivisions: ... 296 found in a fossiliferous level at the top of a shallowwater marine sequence of late pliocene age (benvenuti et al., 1995), calibrated with the gauss/ matuyama transition (li n d s a y et al. , 1980). the montopoli fu should correspond to the mn16b zone and was traditionally included in the early villafranchian lma (table 1), but the marked faunal turnover characterising the transition from the triversa fu to the montopoli fu recommends regarding it as the basal unit of the middle villafranchian (caloi & palombo 1990, 1996). the faunal renewal from triversa to the montopoli fu can be regarded as a true turnover phase, due to the high percentage of last and new appearances, but also to the important structural changes in the faunal complexes, in both the herbivore and carnivore guilds. this is consistent with the significant global changes characterising the piacentian to gelasian transition (actually the beginning of the quaternary as proposed by several authors, see e.g. bowen & gibbard, 2007), with the permanent ice-sheet growth in the northern hemisphere, the first major influx of ice-rafted debris in the middle latitudes of the north atlantic, the onset of extensive loess deposition in china around the gauss/matuyama boundary (marine isotopic stage, mis, 104 to 100) (see inter alios ru d d i m a n et al., 1989; di n g et al., 1997; shackleton, 1997; partridge, 1997a, b; rio et al. 1998; bo w e n & gi b b a r d, 2007 and recently ratified by the international commission on stratigraphy, gi b b a r d & he a d, 2009), the profound changes in eurasian flora assemblages (see inter alios za g w i j n, 1974; gr i c h u k, 1997; su c et al., 1997). bioevents behind this faunal change (e.g. the so-called “elephant-e q u u s e v e n t ” , lindsay et al., 1980) likely occurred close to the piacentiangelasian boundary, driven by climatic cooling, as well as by the effects of changes in the earth climate system: 19-23 ka cycles were superseded progressively by a 41-ka rhythm (orbital obliquity periodicity) accompanied by moderately increased amplitude climatic oscillations. the resulting increase in aridity and more intense seasonality triggered vegetation to reconstruct (suc et al., 1995, and references in bertini, 2003) and caused the disappearance of most forestdwelling taxa, especially small carnivores and arborealscansorial taxa, whereas new large grazers (the horse equus livenzovensis) , mixed feeders (a pr imitive mammuthus meridionalis, the medium-size gazella borb o n i c a) or even browsers (the deer eucladoceros falconeri) appeared (table 3). the taxonomical composition of the montopoli fu resulted primarily from the dispersal, mostly from eastern europe, of large to medium-sized herbivores, while evolutionary substitutions within surviving phyletic lineages were rather negligible. the faunal change indicates that forests gradually gave way to more open environments (including a r t e m i s i a steppe), alternating with warm temperate deciduous forests (see bertini, 2003). indeed, from an ecological point of view, the triversa faunal complex, which had a relatively high frequency of frugivores, developed in environments rather similar to those of modern forests, whereas the structure of the montopoli faunal complex shows some affinit ies with those of modern bush-woodland (pa l o m b o & gi o v i n a z z o, 2006, pa l o m b o 2 0 0 7 b ) . moreover, this event can be considered as the beginning of a dispersal phase leading to a progressive increase in standing richness during the subsequent pliocene and up to the beginning of the early pleistocene. a temperate interlude occurred between 2.5 and 1.8 ma; during this phase the mediterranean climate was established permanently in southwestern europe. a progressive faunal renewal took place, and some dispersal/origination bioevents led to a moderate faunal structural reconstruction of late middle villafranchian fauna. two fu’s have been proposed as characterising this time slice, the “saint vallier” and the costa san giacomo fu (table 1), but the italian “saint vallier” fu is loosely defined as being based on sporadic finds of taxa that also occur in the lfa’s assigned to the costa san giacomo fu. accordingly, the author is inclined to consider the italian late middle villafranchian lfa’s as belonging to only one fu. the “costa san giacomo” name is here retained despite the priority of “s a i n t vallier”. this is because of the rich fossil record of the corresponding lfa (costa san giacomo, anagni, latium), as well to stress the significance of the appearance on the italian peninsula of a wolf-like canid closely related to canis etruscus (a primitive representative of this phyletic lineage might be already present in the early villafranchian vialette lfa, lacombat et al., 2008). as here redefined, the italian costa san giacomo fu should roughly correspond to the mn 17”zone”. the faunal composition is similar to that of the preceding unit as regards the presence of taxa such as “pseudodama” lyra, eucladoceros tegulensis, gazella borbonica, or long-surviving taxa such as the cheetah, acinonyx pardinensis, the hunting hyaena chasmaporthetes lunensis and the proboscidean a . a r v e r n e n s i s , but renewed because of the first appearance, among others, of the middle-sized horse e q u u s stenonis, the goat gallogoral meneghini, and the spiral horned antelope gazellospira torticornis, all parkland dwellers, as well the large-sized and slender legged boar sus strozzii. the presence in the costa san giacomo of canis aff. c etruscus bears witness that the so-called “wolfevent” (az z a r o l i 1983, 1995) was already in progress. the carnivore guild renewal was a gradual phenomenon (sardella & palombo 2007, palombo et al., 2008), which developed throughout the latest gelasian and the earliest calabrian and involved several large and middlesized carnivores, such as the powerful scavenger, pachycrocuta brevirostris, the jaguar-like p a n t h e r a gombaszoegensis (= panthera onca toscana according to hemmer et all., 2003), the cooperative foraging canid, lycaon (xenocyon) falconeri, as well the coyote-like (but see ol i v e, 2006) canis arnensis (pa l o m b o et al. , 2008 and references therein). 3.3 the late villafranchian and the gelasiancalabrian boundary the latest gelasian faunal renewal involved both carnivores and herbivores: most pliocene and early gelasian species disappeared, particularly among herbivores, and new carnivores and herbivores progressively appeared (table 3). the renewal from the middle to late villafranchian lma, should be regarded as a dispersal phase (more than an actual turnover), which developed before and after the gelasian-calabrian boundary, and came to an end during the earliest early m.r. palombo 297biochronology of terrestrial mammals and quaternary subdivisions: ... calabrian, (pa l o m b o, 2004b, 2007a, b). the dispersal phase primarily involved carnivores, since among new taxa none belong to species which evolved in loco, whereas new appearances among herbivores were principally linked to the emergence of new species within pre-existing phyletic lineages (e.g. m a m m u t h u s , equus, eucladoceros, “pseudodama” and large bovids of subgenus leptobos), and subordinately, to immigration of large ruminants, mainly mixed feeders (e.g. procamptoceras and praevibos). these faunal changes indicate that forests or woodlands gradually gave way to more open environments (including a r t e m i s i a steppe), but alternating with warm-temperate deciduous forests. the gradual faunal reconstruction from the latest gelasian to early calabrian took form within an interval of climatic transition, and was possibly driven both by climatic worsening (moderate average cooling mis 70 to58), and modification of internal competitive dynamics, the latter depending on the disappearances of some pre-existing key taxa and ensuing availability of ecological niches (palombo, 2007b). after az z a r o l i (1977) the late villafranchian, at this time considered as coincident with the early pleistocene (s e n s u ag u i r r e & pa s i n i, 1985), would include three fu’s: olivola, t and f (table 1). subsequently, a more recent, fourth fu, pirro was added, and the end of the late villafranchian was dropped before the jaramillo subchron (table 1). lfa’s assigned to the olivola and tasso fu’s are well-known from the upper valdarno basin, where fossil-bearing sediments of two stratigraphically superimposed units are exposed (de gi u l i & ma s i n i, 1 9 8 7 ; to r r e, 1987; az z a r o l i et al., 1988). magnetostratigraphy of these fossiliferous stratigraphical successions provides chronological constraints for olivola plus the tasso fu: in the upper valdarno area, lfa’s assigned to the tasso fu have been correlated to the top of the olduvai subchron (na p o l e o n e et al., 2003), which is around the gssp of the gelasian-calabrian boundary (la vrica section; ag u i r r e & pa s i n i, 1985), whereas lfa’s of the olivola fu (e.g. matassino and poggio rosso lfa’s) are “inferred as pre-olduvaian, not younger than 2.0 ma.” (na p o l e o n e et al. , 2003, pag. 308). the tructure of the faunal complexes of the olivola and tasso fu’s are not very dissimilar, the latter being different essentially for the appearance, among others, of lycaon (xenocyon) falconeri (already present in the latest pliocene spanish fauna of fonelas p-1, ga r r i d o, 2008), equus stehlini (= equus senezensis stehlini, according to alberdi et al., 1998) and the stout bovid leptobos vallisarni. praeovibos is also recorded in the casa frata lfa, whereas gallogoral, gazellospira a n d procamptoceras were not reported (table 3). the occurrence of hippopotamus antiquus in the tasso fu is doubtful, since hippopotamuses from valdarno (already ascribed to the tasso fu), was probably retrieved from fossiliferous layers younger than those of the montervarchi succession (na p o l e o n e et al., 2003). on the other hand, the occurrence in the same stratigraphical layer of h. antiquus and leptobos aff. furtivus at piano dei cavalieri (rieti basin, latium) (masini 1989, ge n t i l i & ma s i n i, 2005), needs to be confirmed (see se g r e na l d i n i & va l l i and references therein). accordingly, faunas assigned to ol i v o l a and ta s s o fu’s seem to be part of the same, progressive faunal renewal, and the hypothesis that they could represent a single fu cannot be ruled out. 3.4 the end of the villafranchian lma and the dawn of the galerian lma during the subsequent early pleistocene (farneta, pirro and colle curti fu’s) (table 2) an important renewal of faunas occurred: most of the typical villafranchian taxa disappeared or became rare while scattered bioevents led to the appearance of new species, either newcomers or ones evolved from preexisting taxa (table 3). the previously mentioned increase in diversity throughout the early late villafranchian (mainly via migrations and dispersal events) had possibly altered the palaeocommunity equilibria, and climate changes possibly removed keystone species causing new intraand inter-guild dynamics, leading mammalian communities to significantly reconstruct (palombo, 2007b). this is the reason why, despite the progressive appearance of new species (most of which will survive in the early middle pleistocene), last appearances prevailed, leading to a progressive reduction in diversity from farneta to colle curti fu’s (table 3). 3.4.1 farneta and pirro fu’s differences in taxonomical composition and structure between tasso and the following farneta fu are mainly related to changes in the herbivore guild and mirror the spread of open environments due to the decrease in average temperature, along with the increase in dryness (be r t i n i, 2003; su c & po p e s c u, 2005). for instance, rhinoceroses similar to stephanorhinus hundsheimensis were the possible ecological substitutes for stephanorhinus etruscus. t h e larger, mixed-feeder praemegaceros obscurus replaced the browser eucladoceros, and a more specialised form replaced the mixed-feeder “pseudodama” nesti. it is worth noting that br e d a & ma r c h e t t i (2007) doubtfully reported ?eucladoceros ex gr. ctenoides-dicranios and ?megaloceros obscurus from the main brown coal level (subunit 5) of the biogenetic unit of leffe formation (bergamo, northern italy), but the actual co-occurrence of these large deer needs to be fully substantiated. among carnivores, megantereon whitei, a saber-tooth cat of african origin, first appeared. the faunal renewal between the farneta and pirro fu (table 2) is marked by the appearance of some arriving african taxa, such as the large h i p p o p o t a m u s antiquus (magri et al., 2009), and (doubtfully) the cercopithecid t h e r o p i t h e c u s, a mixed-feeding genus whose extant species inhabits the high grasslands of ethiopia and eritrea (ro o k et al., 2004, but see pa t e l et al., 2007). this evidence of african immigration to southernmost europe stresses the importance of “out of africa” migratory waves, which occurred approximately around 1.6/1.3 ma (ma r t i n e zna v a r r o, 2004). other immigrants had an asian/european origin, as the ovibovine m e g a l o v i s and the rather stout bovine b i s o n (eobison) degiulii, the latter replacing the slender leptobovines. among perissodactyls, the middle-sized, slender limbed equus alt idens and the larger e q u u s s u e s s e n b o r n e n s i s were certainly present, whereas equus stehlini is no longer recorded (see al b e r d i & palombo, in press for a discussion). among carnivores the middle-sized bone crusher canis mosbachensis first appeared and lycaon (xenocyon) lycaonoides substituted the less advanced l. falconeri. the dispersal of 298 m.r. palombo homo in the italian peninsula is testified by the finding of lithic implements in the karstic network of pirro nord, the local eponym of the pirro fu (ar z a r e l l o et al. , 2007). all in all, forest-dwelling taxa dwindled, whereas species inhabiting prair ies, savanna or steppes increased in percentage. the prevalence of dry and open environments at the time of the pirro fu (and colle curti fu as well) is confirmed by the great structural compatibility of these faunas with those of present day savanna/bushland habitats (pa l o m b o, 2007b). nevertheless, forest areas were still rather abundant, and woodlands spread in the more temperate and humid climatic phases, as evidenced, for instance, by the presence of the browser moose cervalces carnutur u m in the subunit 7 of leffe formation (bergamo, northern italy) (breda & marchetti, 2005, 2007), which deposited shortly before the jaramillo subchron (muttoni et al., 2007). the occurrence at pietrafitta (umbria, central italy) of a vole close to microtus (allophaiomys) ex gr. m. ruffoi, and of microtus (allophaiomys) chalinei a n d mimomys pusillus in a large mammal fauna whose taxonomical composition and structure is consistent with that of the the farneta fu (ge n t i l i et al., 1996; ba r i s o n e et al. ,2006; pa l o m b o & gi o v i n a z z o, 2006), as well the presence at pirro nord of a more evolved m i c r o t u s ( a l l o p h a i o m y s ) ex gr. m. ruffoi, provide a correlation of the farneta and pirro fu with the earliest biharian (early biharian i, ma s i n i & sa l a, 2007). accordingly, and taking into account magnetostratigraphical dating of tuscan lfa’s assigned to olivola plus the tasso fu, the farneta and pirro fu’s developed during the pre-jaramillo early pleistocene, but the actual chronological extent of each fu is based only on biochronological estimates. 3.4.2 colle curti fu and the beginning of the mid pleistocene revolution (mpr) the transition from the early to middle pleistocene, mid-pleistocene revolution (mpr) (from about 1.2 to 0.6 ma) marks a fundamental change in the earth’s climate system (ma s l i n and ri d g w e l l, 2005) and represents a major episode in mammalian fauna reorganisation over the course of the cenozoic. orbital obliquity at 41-ka cycles was superseded progressively by a 100-125-ka rhythm, sustained by four-five precessional cycles, and accompanied by increased amplitude climatic oscillations (table 2). glacial phenomena intensified, temperature and moisture dropped notably, vegetational “exotic” essences, quite common in earlier floras, progressively disappeared and sustained climatic changes prevented these floral elements from becoming re-established (bertini, 2003). these changes spurred a shift in environments and constrained the geographical diffusion of a number of taxa, allowing dispersal waves that drove the reorganisation of large mammal communities. community rebuilding came to an end during the beginning of the middle pleistocene with the disappearance of the last surviving villafranchian species, such as pachycrocuta brevirostris and panthera gombazsoegensis (table 3). thus, at the time of mpr, fauna was characterised by the presence of long surviving villafranchian taxa and by a progressive increase in taxa, which also persisted into the middle pleistocene. such a framework of “mixed faunal elements” was regarded by authors either as a “transitional fauna” (bo n i f a y, 1978; az z a r o l i et al., 1988) or a distinct biochron (e.g. protogalerian sensu caloi & palombo, 1995, epivillafranchian sensu kahlke 2007 and previous papers; ‘latest villafranchian’ sensu koufos, 2001 or ‘final villafranchian’ spassov, 2003). on the other hand, if middle pleistocene faunas are clearly to be considered as ‘modern’ when compared to those from the villafranchian (pa l o m b o, 2004b), which criteria should be used to define the ‘theoretical’ boundary between the villafranchian and the following galerian lma? according to gl i o z z i et al. (1997) (table 1), the beginning of the galerian lma would be conventionally marked by the appearance, among others, of praemegaceros verticornis, which is first recorded in italy at the colle curti lfa (colle curti fu, late early pleistocene, jaramillo subchron, coltorti et al., 1998). this giant deer has been recently found in the spanish fuente nueva 3 and the barranco leon lfa, dated at about 1.3 ma (ag u s t í & ma d u r e l l, 2003), which retain several villafranchian taxa, as does the colle curti lfa. moreover, the pirro nord (latest villafranchian) and the colle curti lfa’s exhibit a relatively high coefficient of similarity (pa l o m b o & va l l i, 2005). consequently, the col le curti lfa stil l looks closer to the latest villafranchian lfa’s than to the ensuing typical galerian ones, despite the llsdk of praemegaceros verticornis, cervalces latifrons (breda & marchetti, 2005), and possibly of subgenus b i s o n , the significant reduction in biodiversity shown by carnivores, as well as the innovative characteristics of the arvicolids (sa l a & ma s i n i, 2007). all in all, the the pirro and colle curti fu’s correspond to a time slice during which the villafranchian were gradually but not completely displaced by some typical galerian large mammals foreshadowing the coming of a new age. this evidence encourages a redefinition of the galerian lma (cf. pa l o m b o, 2004a and references therein, kahlke, 2007). 3.5. the mpr accomplishment and the onset of typical galerian mammalian faunas as above mentioned, the faunal renewal leading to the typical galerian faunas finds its origin in two distinct trends: 1) the progressive reduction in richness characterising late early pleistocene faunas (from the farneta to the colle curti fu’s), 2) the subsequent dispersal and the progressive spread in italy of taxa from eastern and central europe, that triggered a rapid increase in diversity at the beginning of the middle pleistocene (slivia fu) (palombo 2007b and references therein). it is noteworthy that this faunal change involved both carnivore and herbivore guilds at various times. the most important change in the former had already taken place prior to the jaramillo subchron, at the pirro–colle curti fu’s transition, with the disappearance of some large taxa, either flesh-eaters or bone-breakers, such as large canids and felids (table 3) (palombo et al., 2008 and references therein). this is the starting point for a reversal in the proportion of carnivores versus herbivores: indeed, across the early to middle pleistocene (slivia fu), the faunal renewal was strongly biased in favour of large herbivores, while the carnivore guild changed at a slower pace. taxa dispersed from eastern and central europe reached the italian peninsula in succession, thus leading an important and relatively 299biochronology of terrestrial mammals and quaternary subdivisions: ... rapid increase in diversity at the beginning of the middle pleistocene. these changing faunas represent a major large mammal community reorganisation throughout the quaternary. this dispersion phase was probably triggered by notable climatic changes that correspond to the onset of the pronounced glacial–interglacial fluctuations as observed in the marine isotope record during the late early pleistocene (mis 25 to 22-20), while the progressive increase in diversity is seen as a consequence of the ensuing onset of wetter climatic conditions (see pa l o m b o & gi o v i n a z z o, 2006 and references therein). instead of replacing any one species, these taxa enriched the herbivore guild, as well as the large mammal community as a whole (palombo, 2007b and references therein). even if, on a larger temporal scale, the progressive modification in the structure of large mammal faunas of the italian peninsula began before the jaramillo subchron, it was shortly before the early to middle pleistocene boundary that the major renewal and important ecological reorganisation of faunal complexes took place (palombo, 2007b). throughout the course of time (table 3), the local appearances of several pachyderms (e l e p h a s (palaeoloxodon) antiquus, mammuthus trogontherii, stephanorhinus kirchbergensis, stephanorhinus hemit o e c h u s), large (megaloceros savini, praemegaceros solilhacus), and medium-sized deer (capreolus capreolus suessenbornensis, cervus elaphus acoronatus a n d possibly dama clactoniana), as well as large (hemibos galerianus, bos primigenius) and middle-sized bovids (ovis ammon antiqua, hemitragus bonali), together with caballine horses (equus mosbachensis), all mainly mixed feeders or grazers, inhabiting open landscapes, bushlands or wooded grasslands, brought about a major change in the herbivore guilds (palombo, 2007b). among carnivores, crocuta crocuta first appeared (ponte galeria 2 lfa, pg2 sequence, about 750-650ka, milli & palombo, 2005 and references there in), whereas some other large carnivores, active hunters that were both flesh-eaters and scavengers [such as ursus deningeri, panthera fossilis, isernia lfa, about 600 ka (coltorti et al., 2005); a hyaena, hyaena prisca, whose taxonomical identification is still matter of debate at the ponte galeria 3 lfa (see ca l o i & pa l o m b o, 1980; pa l o m b o et al., 2008; tu r n e r et al., 2008), pg3 about 650-550 ka ( mi l l i & pa l o m b o, 2005); panthera pardus, valdemino cave lfa, isernia fu (sa l a, 1992) and isernia lfa (sala, 2006) ], had their lowest stratigraphical occurrence even later. these species, together with s. hundsheimensis, equus altidens, e. suessenbornensis, p. verticornis and b. shoetensacki are eponymous of the “typical” galerian faunas. most authors recognise in the “middle” galerian (sensu gliozzi et al., 1997) two fu’s, slivia and isernia which are clearly differentiated by the small mammals: mymomys savini (slivia lfa) and arvicola mosbachensis (isernia lfa). the small mammal association found at the archaeological site isernia la pineta (molise), represents the oldest toringian fauna recorded in italy to date (sala & masini, 2007) and represents the main renewal of small mammals throughout the galerian lma. pe t r o n i o and sa r d e l l a (1999) proposed the introduction of the ponte galeria fu (table 1), by these authors regarded as intermediate in taxonomical composition, and in age as well, between the slivia and isernia fu’s. this, because of the persistence of pachycrocuta brevirostris and panthera gombaszoeg e n s i s in the slivia fu, the exclusive occurrence of hemibos galerianus in the “ponte galeria fu” and the appearance of bos primigenius in the isernia fu. nevertheless, slivia and ponte galeria 2 lfa’s would be assumed to be part of the same fu due to the uncertain identification of some herbivores from slivia lfa, and the assumption that carnivores absent from the ponte galeria cu have in fact been found in the slivia lfa. unfortunately, there are no stratigraphical constraints for the age of the slivia fu, even if it can be correlated with the late biharian, which roughly extends from 0.95 to 0,6 ma, due to the occurrence of m. savini associated with that of microtus (stenoc r a n i u s) and microtus (terricola). conversely, in the roman basin, the integrated mammal biostratigraphy and sequence stratigraphy approach represents a valid tool to identify and to correlate physical and biological events. the biochronological and sequence-stratigraphical scheme proposed for the ponte galeria area, highlights that the sequence stratigraphical framework can constrain the possible chronological interval in which a bioevent, even if local, occurred (see mi l l i & palombo, 2005). the transition from the middle to late galerian (fontana ranuccio fu) possibly occurred around 550–500 ka, due to the absolute age available for the lfa’s ascribed to isernia fu (notarchirico and isernia lfa’s, estimated age about 600 ka by le f é v r e & raynal, 1999; lefévre et al., 1999; and coltorti et al., 2005, respectively), and the fontana ranuccio fu (fontana ranuccio lfa, estimated age about 458 ka, biddittu et al., 1979). during the late middle galerian (fontana ranuccio fu), “villafranchian” taxa were not yet recorded and the number of very large herbivores diminished (table 3). the occurrence of “galerian” equids and megacerines is doubtful and the specialised and slightly larger h. antiquus was replaced by h i p p o p o t a m u s a m p h i b i u s and, among carnivores, ursus arctos appeared as well as felis silvestris (table 3). in the second half of the middle pleistocene, increasingly different habitats supported increasingly varied faunas (cf. tr i a n t i s et al., 2003), with new dynamic interspecific relationships. in fact, with the end of the galerian (fontana ranuccio fu) and the transition to the following aurelian lma, the most flexible species became the dominant group, the percentage of browsers increased and fauna progressively acquired modern characteristics (palombo 2007b and references therein). 3.6 the aurelian lma and the middle to late pleistocene boundary gliozzi et al. (1997) proposed the aurelian as a new lma, differing from the galerian lma because of the appearance of taxa that constitute the core of the modern mammalian fauna, whereas some “galerian”species (such as horses, megacerine deer, m e d i u m s i z e d , bovid ovis ammon antiqua and hemitragus bonali, and large bovide, bison shoetensacki) were no longer pre300 m.r. palombo sent. according to gl i o z z i et al. (1997), three distinct, main faunal complexes could be detected: early, middle and late aurelian, characterised by an increase in the percentage of modern taxa. the early and middle aurelian were subdivided on the basis of faunal differences between two already created fu’s, torre in pietra and vitinia (ca l o i and pa l o m b o 1990, 1996, but see below), while for the late aurelian (mis 5-2) no characteristic fu’s have correctly been designated due to the monotonous taxonomical composition of the last interglacial faunas, as well the only sporadic occurrence of the so called “cold taxa” during the last glacial (but see petronio et al, 2007). 3.6.1 the aurelian lma and the question of vitinia fu the torre in pietra and vitinia fu’s have been defined on the basis of palaentological and stratigraphical evidence collected in the roman basin (caloi et al., 1998; but cf. palombo et al., 2004 and references therein). along the latium coast, rich lfa’s (torre in pietra, la polledrara di cecanibbio, collina barbattini, castel di guido, malagrotta) have been recovered either from fossiliferous deposits of the aurelia formation (conato et al., 1980) or the pg6 sequence, both correlated with mis 9 (milli & palombo, 2005). in these lfa’s, assigned to the torre in pietra fu the llsdk of canis lupus, ursus spelaeus and megaloceros giganteus is reported. in the same area, lfa’s uncovered in fossiliferous levels of the vitinia formation (conato et al., 1980) or pg7 sequence (milli, 1997), correlated with mis 7 (e.g. torre in pietra upper levels, vitinia level e, cerveteri) (palombo et al., 2003 and references therein) were previously ascribed to the vitinia fu’s (ca l o i & pa l o m b o, 1995; caloi et al., 1998) essentially because of the abundance of a primitive fallow deer, dama dama tiberina ( l o c a l l y associated with the pre-existing larger dama dama clactoniana), as well the appearance, among others of cervus elaphus with features similar to those of modern red deer and of equus hydruntinus. nevertheless, the structure and the taxonomical composition of the torre in pietra and vitinia faunal complexes are similar (palombo & mussi, 2001; palombo 2004), thus the division into two fu’s seems to be based on weak palaentological data, moreover new stratigraphical evidences call for a revision of these biochrons. in the 1990’s, two lfa’s, sedia del diavolo and monte delle gioie (today, no longer exposed due to of the intense urbanization of rome after world war ii), were assigned to the vitinia fu due to the abundance of dama dama tiberina remains in the alluvial deposits overlaying the “tufo lionato” (a lithified pyroclastic flow deposit from albani volcanic complex, dated 355 ka by karner et al., 2001) where also equus hydruntinus was found (ca l o i & pa l o m b o, 1995). ca l o i et al., (1998) correlated these bone-bearing deposits with the vitinia formation (mis 7), but recently the overlain ash flow has been dated at 285 ± 1 ka (marra & rosa, 1995; karner et al., 2001). following this new chronological data, the deposition of the fluvio-lacustrine sediments overlaying the “tufo lionato” at sedia del diavolo, occurred approximately during the time span between 355 and 285 ka (palombo et al., 2004). accordingly, the llsdk dama dama tiberina in italy is documented in deposits correlated with the mis 9, thus the vitinia fu cannot be considered a valid biochron. the lfa’s previously ascribed the torre in pietra and the vitinia fu’s have to be included in a single fu (named torre in pietra fu for priority reason) (table 1). summarizing, several bioevents characterised the beginning of the torre in pietra fu, as well as the beginning of the aurelian lma (subdivided into early and late aurelian) as here redefined: for instance canis lupus first appeared as well as ursus spelaeus that subs t i t u t e d u. deningeri, megaloceros giganteus, dama dama “tiberina, and bubalus murrensis (palombo, 2007 and unpublished data), the “steppe horse e. hydruntinus dispersed along the italian peninsula. furthermore, some new medium-sized taxa appeared, when more severe, arid climatic oscillations favoured the spread of “mountain” bovids (capra ibex and rupicapra) towards the southernmost regions of the italian peninsula, whereas galerian megacerine deer and horses, o v i s ammon antiqua and bison shoetensacki are no longer recorded (table 3). all in all, with the end of the galerian (fontana ranuccio fu) and the transition to the aurelian (torre in pietra fu), the most flexible species became the dominant group, the percentage of browsers increased and fauna progressively acquired modern characteristics. this is consistent with a moderate woodland expansion under increasingly mild climatic conditions characterising the interglacial phases, as well as the increase in north to south and east to west climatic gradients leading to the fragmentation of italian habitats. the structure of aurelian mammalian faunas was fully attained long before the beginning of the beginning late pleistocene, thereby the transition from galerian to aurelian lma predated the middle to late pleistocene boundary. 3.6.2 the late pleistocene the last interglacial lfa’s did not substantially differ from those recorded during the late middle pleistocene. the rare species bubalus murrensis is no longer present, while modern fallow and red deer substitute the late middle pleistocene subspecies, but the core of the early aurelian faunas keeps roughly unchanged. although the last glacial phase caused a remarkable shift in the vegetational cover and in the distribution of mammals in europe, minor changes characterised the transition from the last interglacial to the last glacial faunal complexes on the italian peninsula (palombo, 2007b). during the last glacial, the faunal biodiversity increased with the arrival of some “cold” species, such as the typical, mammuthus primig e n i u s, the woolly rhinoceros coelodonda antiquitatis, the elk alces alces, inhabiting a “mammoth steppe”-like environment extending throughout the eastern po valley (gallini & sala, 2001). mammoth and woolly rhinoceros, as well the wolverine, gulo gulo, reached the tyrrhenian coast (latium) and were widespread in the south-eastern part of the italian peninsula, where alopex lagopus is also recorded, while rangifer tarand u s only reached the westernmost geographical boundary of the italian coast ( ca l o i & pa l o m b o, 1995; sa l a, 2005). the spread of “cold” species across the italian peninsula was profoundly conditioned by microclimate and physiography, and the taxonomical compo301biochronology of terrestrial mammals and quaternary subdivisions: ... sition and structure of lfa’s could vary greatly, depending on the geographical position of fossiliferous sites. that, coupled with the high percentage of extant species, prevent any fu to be fairly defined. moreover, the faunal assemblages were progressively depleted of some long-surviving galerian species. pachyderms were most affected by cl imatic deter ioration. h i p p o p o t a m u s survived only until the end of the mis 5a, whereas elephas antiquus occurred also during mis 4 and s t e p h a n o r h i n u s was still present during mis 3, while panthera spelaea survived till the beginning of the holocene (boschian et al., 1995). all in all, the mammal faunas on the italian mainland maintained “temperate-cool” characteristics even during the cold-arid peaks of the last glacial. broadleaved wooded release “refugial” areas always existed on the tyrrhenian side of the peninsula, while the climate on the adriatic side was probably drier. therefore, some “warm” species remained on the italian peninsula longer than elsewhere, and turnovers in successive communities were less dramatic than in northern europe. with the deglaciation phase at the beginning of the holocene, dramatic moisture and vegetation change led to marked changes in mammalian faunas, particularly in their abundance, leading to the megafauna extinction. 4. conclusion several evidences show that, at least as far as the italian peninsula is concerned, global climatic changes are a contributing factor, especially in the first appearances of large mammals. this permitted the dispersal of new taxa, because mammals frequently reacted to the plio-pleistocene climate changes, expanding their distribution area or migrating rather than by evolving and producing new species. climate change, via migrations and dispersal events, caused diversity bursts but altered palaeocommunity equilibria, leading to new intraand inter-guild dynamics. we can also hypothesize that cause-and-effect relationships between climatic oscillations and faunal changes may be the cumulative result of the responses of individual species and that climatic changes could have caused the removal of keystone species. accordingly, migratory responses to climate change and physical-environmental disturbances, together with biotical interactions mainly contributed to faunal evolution in successive phases by discrete bioevents, maybe diachronous even in a restricted geographical area such as the western europe. this fact prevents any detailed biochronological framework from having wide geographical significance and predisposes it to change in the light of new findings. this is, e.g., the case of weakly defined fu’s such as the italian “saint vallier” (gl i o z z i et al., 1997) and the vitinia (ca l o i & pa l o m b o, 1990) fu’s, which stratigraphical evidences forced its deletion. moreover, increasing palaeontological and stratigraphical data sometimes leads us to better discriminate bioevents, highlighting the gradual renewal between successive biochrons, but blurring their clear identification as in the case of the olivola and tasso fu’s. thus, only higher rank biochronological units (land mammal ages, lmas) whose separation is based on palaeobiological events which have a wide territorial significance could be useful for chronological correlations. nonetheless, the transition between successive lmas does not always correspond to the boundaries separating marine series or stages. for instance, the villafranchian lma approximately began with the late pliocene (piacentian) and the transition from the early to the middle villafranchian lma happened around the pliocene/pleistocene (piacentian/ gelasian) boundary, whereas the transition to the late villafranchian took place during the latest gelasian, and those from the villafranchian to galerian lma and from the galerian to aurelian lma respectively predated the beginning of the middle and late pleistocene. concerning the villafranchian to galerian lma transition, from what has been previously reported on the biochronological patterns of large mammals, it possibly occurred close to mis 25, where ci t a & ca s t r a d o r i (1995, but see ci t a et al. , 2006) previously proposed lowering the early to middle pleistocene boundary. acknowlegement thanks are due to the organising committee of the aiqua congress “il quaternario nella cartografia carg2 for the opportunity to present this paper and to the anonymous reviewers for their helpful comments on the manuscript. the english version was revised by steven t. haire work supported by the project miur università 2007 c26a07lpwj. references aguirre e. & pasini g. (1985) the pliocene-pleistocene boundary. episodes, 8 (2), pp. 116-120. ag u s t i, j. & ma d u r e l l, j. (2003) los arvicolidos (muroidea, rodentia, mammalia) del pleistoceno inferior de barranco leon y fuente nueva 3 (orce, granada). datos preliminares. in: toro, i., agusti, j. & ma r t i n e zna v a r r o , b. (e d s): el pleistoceno inferior de barranco leon y fuente nueva 3, orce ( g r a n a d a ). junta de andalusia. consejeria de cultura: 137-146, sevilla alberdi m.t. & palombo m.r. (in press) the equidae of the early pleistocene site of pirro (southern italy). palaeontographica alberdi m.t., ortiz jaureguiza, e. & prado j.l. (1998) a quantitative review of european stenonoid horses. journal of paleontology, 72, pp. 371-387. am b r o s e t t i p., az z a r o l i a., bo n a d o n n a f.p. & fo l l i e r i m. (1972) a scheme of pleistocene chronology for the tyrrhenian side of central italy. b o l l e t t i n o della. società geologica italiana, 91, pp. 169-184. arzarello m., marcolini f., pavia g., pavia m., petronio c., pe t r u c c i m., ro o k l. & sa r d e l l a r. (2007) first evidence of early homo occupation in europe: the site of pirro nord (southern italy). naturwissenschaften, 94, pp. 107112 azzaroli a. (1977) the villafranchian stage in italy and the plio-pleistocene boundary. giornale di geologia, 41, pp. 61-79. 302 m.r. palombo az z a r o l i a. (1982) remarques sur les subdivisions chronologiques du villafranchien. actes colloque “le villafranchien mediterranéen”, lille 9-10 décembre 1982, 1, pp. 7-14. azzaroli a. (1983) quaternary mammals and the “endvillafranchian” dispersal event a turning point in the history of eurasia . p a l a e o g e o g r a p h y , palaeoclimatology, palaeoecology, 4 4, pp. 117139. azzaroli a. (1995) the ‘elephant-equus’ and the ‘endvillafranchian’ events in eurasia. in: vr b a e. s., de n t o n g. h., pa r t r i d g e t. c. & bu r c k l e l. h. (eds): paleoclimate and evolution with emphasis on human origins. new haven and london (yale university press, pp. 311–318. azzaroli a., de giuli c., ficcarelli g. & torre d. (1988) late pliocene to early mid-pleistocene mammals in eurasia: faunal succession and dispersal e v e n t s. palaeogeography, palaeoclimatology, palaeoecology, 66, pp. 77-100. ba r i s o n e g., ar g e n t i p. & ko t s a k i s t. (2006) p l i o pleistocene evolution of the genus castoro(rodentia, mammalia) in europe: c. fiber p l i c i d e n s of pietrafitta (perugia, central italy). geobios, 39, pp. 757-770. bedetti c., palombo m.r. & sardella r. (2001) large mammals and birds last occurrences in the late pleistocene of italian peninsula. in: cavaretta g., gioia p., mussi m. & palombo m.r. (eds), the world of elephant, cnr, roma, pp. 701-703. be n v e n u t i m., do m i n i c i s. & ro o k l . (1995) inquadramento stratigraficodeposizionale delle faune a mammiferi villafranchiane (unita faunistiche triversa e monopoli) del valdarno inferiore nel la zona a sud del l’arno (toscana) . i l quaternario 8, 457–464. be r g g r e n w.a. & va n co u v e r i n g j.a. ( 1 9 7 8 ) . b i o c h r o n o l o g y . i n co h e e g.v., gl a e s s n e r m.f. & hedberg h.d. (eds): contribution to the geologic time scale. american association of petroleum geologists bulletin, 50, pp. 1487-1500. bertini a. (2003) early to middle pleistocene changes of the italian flora and vegetation in the light of a chronostratigraphic framework. il quaternario 16(1bis), pp. 19-36. bertini a. & roiron p. (1997) evolution de la végétation et du climat pendant le pliocène moyen en italie centrale: apport de la palynologie et des macroflores à l’étude du bassin du valdarno supérieur, (coupe de santa barbara). comptes rendus de l’académie des sciences de paris, sér. 2a, 324, pp. 763–771 biddittu i., cassoli p.f., radicati di brozolo, f., segre a.g., segre naldini, e. & villa, i. (1979) anagni, a k-ar dated lower and middle pleistocene site, central italy: preliminary report. quaternaria, 2 1, pp. 53-71. bo n i f a y m . f . (1978) faunes de transit ion du pléistocène moyen de france. bul letin du museum d’anthropologie et préhistoire de monaco, 22, pp. 5–15. bo s c h i a n g. ma l l e g n i f. & to z z i c. (1995) the epigravettian and mesolithic site of fredian shelter (in tuscany). quaternaria nova, 5, pp. 45-80. bowen d.q. & gibbard p. l. (2007) quaternary is here to stay. journal of quaternary science. 22 (1), pp. 3-8 br e d a m. & ma r c h e t t i m . (2005) systematical and biochronological review ofplio-pleistocene alceini (cervidae; mammalia) from eurasia. q u a t e r n a r y science rewies, 24, pp.775-805. breda m. & marchetti m. (2007) pleistocene mammal faunas from the leffe basin (bergamo, northern italy): revision and new data. courier forsch. inst. senckenberg 259, pp. 61-77. caloi & palombo, 1995, ca l o i l. & pa l o m b o m . r . (1990) osservazioni sugli equidi italiani del pleistocene medio inferiore. geologica romana, 26 (1987), pp. 187-221, caloi l., palombo m.r. (1995) le mammalofaune del pleistocene inferiore nell’italia centrale. studi geologici camerti, vol. spec. 1994 (b), pp. 487501 ca l o i l. & pa l o m b o m . r . (1996) latest early pleistocene mammal faunas of italy, biochronological problems. il quaternario, 8 (2), pp. 391-402 caloi l., palombo m.r. & zarlenga, f. (1998) late middle pleistocene mammals faunas of latium; stratigraphy and environmen . q u a t e r n a r y international, 47/48, pp. 77-86. ci t a m. b. & ca s t r a d o r i d . (1995) workshop on marine sections from the gulf of taranto (southern italy) usable as potential stratotypes for the gssp of the lower, middle and upper pleistocene. il quaternario, 7 (2), pp. 677–692. ci t a b.m., ca p r a r o l., ci a r a n f i n., di st e f a n o e . , marino m., rio d., sprovieri r. & vai g.b. (2006) calabrian and ionian: a proposal for the definition of mediterranean stages for the lower and middle pleistocene. episodes, 29(2), pp. 107-113. co l t o r t i m., al b i a n e l l i a., be r t i n i a., fi c c a r e l l i g . , laurenzi m.a., napoleone g. & torre, d. (1998) the colle curti mammal site in the colfiorito area (umbria-marchean apennine, italy): geomorphology, stratigraphy, paleomagnetism and palynology. quaternary international 47/48, pp. 107-116. co l t o r t i m., fe r a u d g., ma r z o l i a., pe r e t t o s., to nth a t c., vo i n c h e t t.p., ba h a i n j.-j., mi n e l l i a. & th u n ho h e n s t e i n u. (2005) new 40ar/39ar, stratigraphic and palaeoclimatic data on the isernia la pineta lower palaeolithic site, molise, italy. quaternary international, 131, pp. 11–22. conato v., esu d., malatesta a. & zarlenga f. (1980) new data on the pleistocene of rome . quaternaria, 22, pp. 131–176. de giuli c. & masini f. (1987) late villafranchian faunas in italy: the casa frata local fauna (upper valdarno, tuscany). palaeontographica italica 7 4: 1–9. de giuli c., ficcarelli g., mazza p. & torre d. (1983) confronto tra successioni marine e continentali del pliocene e pleistocene inferiore in italia e nell’area mediterranea. bollettino della società paleontologica italiana, 22, pp. 323-328. di n g z., ru t t e r n.w., & li u t . (1997) the onset of extensive loess deposition around the g/m boundary in china and its palaeoclimatic implications. quaternary international, 40, pp. 53-60. gallini v. & sala b. (2001) – settepolesini di bondeno (ferrara -eastern po valley): the first example of 303biochronology of terrestrial mammals and quaternary subdivisions: ... mammoth steppe in italy. in: cavarretta g., gioia p., mussi m., & palombo m.r. (eds), the world of elephants, cnr, rome, pp. 272-275. ga r r i d o g . (2008) el registro de vulpes alopecoides (forsith-major, 1877); canis etruscus f o r s i t h major, 1877 y c a n i s c f . falconeri f o r s i t h m a j o r , 1877(canidae, carnivora, mamalia) en fonelas p1 (cuenca de guadix, granada).in ar r i b a s he r r e r a a. (ed.) vertebrados del plioceno superior terminal en el suroeste de europa: fonelas p1 y el proyecto fonelas. publicaciones del instituto geologico de espana, cuadernos del museo geominero, 10, 159-186. gentili s, abbazzi l, masini f, ambrosetti p, argenti p. & to r r e d. (1996) voles from the early pleistocene of pietrafitta (central italy, perugia). acta zoologica cracoviensia, 39(1), pp. 185–199. ge n t i l i s. & ma s i n i f . (2005) an outline of italian leptobos and a first sight on leptobos aff. vallisarni from pietrafitta (early pleistocene, perugia). quaternarie, hors series 2, 81–89. gh i n a s s i m., ma g i m., sa g r i m. & si n g e r b . s . (2004) arid climate 2.5 ma in the pl io–pleistocene valdarno basin (northern apennines, italy) . palaeogeography, palaeoclimatology, palaeoecology 207, pp. 37–57. gi b b a r d p. & he a d m.j. (2009) the definition of the quaternary system/era and the pleistocene series/epoch. quaternarie 20 (2), 125-133. gliozzi e., abbazi l., ambrosetti p., argenti p., azzaroli a., ca l o i l., ca p a s s o ba r b a t o l., di st e f a n o g . , es u d., fi c c a r e l l i g., gi r o t t i o., ko t s a k i s t . , ma s i n i f., ma z z a p., me z z a b o t t a c., pa l o m b o m.r., petronio c., rook l., sala b., sardella r., zanalda e. & torre d. (1997) biochronology of selected mammals, molluscs, ostracods from the middle pliocene to the late pleistocene in italy. the state of the art. rivista italiana di paleontologia i stratigrafia, 103 (3), pp. 369-388. grichuk v.p. (1997) late cenozoic change in flora in extra-tropical eurasia in the light of palaeomagnetic stratigraphy. i n : va n co u v e r i n g e . (ed.), the pleistocene boundary and the beginning of the quaternary. cambridge university press, pp. 104113. guerin c. (1982) première biozonation du pléistocène européen: principal résultat biostratigraphique de l ’étude des rhinocerotidae (mammalia, perissodactyla) du miocène terminal au pléistocène supérieur d’europe occidentale. geobios, 15, pp. 593-598. guerin c. (1990) biozones or mammal units? methods and limits in biochronology. in: lindsay, e.h., fahlbusch, v. & mein, p. (eds): european neogene mammal chronology, pp. 119-130; plenum press, new york. he m m e r h., ka h l k e r.d., ke l l e r t. (2003) p a n t h e r a onca gombaszogensis (kretzoi, 1938) from the early middle pleistocene mosbach sands (wiesbaden, hessen, germany) a contribution to the knowledge of the variability and history of the dispersal of the jaguar. neues jahrbruch für geologie und paläontologie abhandlungen, 2 2 9, pp. 31–60. kahlke r.-d. (2007) late early pleistocene european large mammals and the concept of an epivillafranchian biochron. c o u r i e r f o r s c h u n g s i n s t i t u t senckenberg, 259, pp. 265-278. karner d.b., marra f. & renne p.r. (2001) the history of the monti sabatini and alban hills volcanoes: groundwork for assessing volcanic-tectonic hazards for rome. journal of volcanology and geothermal research 107, pp. 185–219. ko u f o s g . d . (2001) the villafranchian mammalian fauna and biochronology of greece. bollettino della societa` paleontologica italiana 4 0, pp. 217–223. lacombat et al., 2008 la c o m b a t f., ab b a z z i l., fe r r e t t i m.p., ma r t í n e znavarro b., moul p.-e., palombo m.r., rook l., turner a. & valli a.m.f. (2008) new data on the early villafranchian fauna from vialette (hauteloire, france). collection of the crozatier museum (le puy-en-velay, haute-loire, france). quaternary international. 179 (1), pp. 64-71 lefèvre, d. & raynal, j.p. (1999) etudes géologique à notarchirico et dans le bassin de venosa: premier bilan et perspectives. in: piperno, m. (ed.): notarchirico. un sito del pleistocene medio iniziale nel bacino di venosa: 253258. edizioni osanna, italia. le f è v r e, d., ra y n a l, j.p. & ve r n e t, g. (1999) enregistrements pléistocènes dans le bassin de venosa. in m. piperno (ed.): notarchirico. un sito del pleistocen medioiniziale nel bacino di venosa”: 139-174; edizioni osanna, italia. li n d s a y e. (2003) chronostratigraphy, biochronology, datum events, land mammal ages, stage of evolution, and appearance event ordination. bulletin of the american museum of natural history: no. 279, pp. 212–230. li n d s a y e.h., op d y k e n.d. & jo h n s o n n . m . (1980) pliocene dispersal of the horse equus and late cenozoic mammalian dispersal events. n a t u r e , 287, pp. 135–138. li n d s a y e.h., op d y k e n.d. & fe i j f a r o . (1995) correlations of selected late cenozoic mammal faunas with the magnetic polarity time scale. terra nostra, 2/95, pp. 164. li n d s a y h. & te d f o r d r . h . (1990) development and application of land mammal ages in north america and europa, and comparison. in: lindsay h., fa h l b u s c h w. & me i n p . (eds): european neogene mammal chronology. plenum press, new york, pp. 601-624. magri d., di rita f. & palombo m.r. (2009) an early pleistocene interglacial record from an intermontane basin of central italy (scoppito, l’aquila). quaternary international, doi: 10.1016/j.quaint. 2009.04.005. marra f. & rosa c. (1995) stratigrafia e assetto geologico dell’area romana. memorie descrittive della carta geologica d’italia, 50, pp. 49-118. masini f. & sala b. (2007) largeand small-mammal distribution patterns and chronostratigraphic boundaries from the late pliocene to the middle pleistocene of the italian peninsula. q u a t e r n a r y international, 160 (1), pp. 43-56. maslin m. a. & ridgwell a. j. (2005) mid-pleistocene revolution and the ‘eccentricity myth. in: head m. 304 m.r. palombo j. & gibbard p.l. (eds): early–middle pleistocene transition: the landocean evidence. geological society, london, special publications, 247: 19–34 mi l l i s. & pa l o m b o m.r. (2005) the high-resolution sequence stratigraphy and the mammal fossil record: a test in the middle–upper pleistocene deposits 251 of the roman basin (latium, italy). quaternary international, 126 –128, pp. 251-270. milli s. (1997) depositional setting and high-frequency sequence stratigraphy of the middle-upper pleistocene to holocene deposits of the roman basin. geologica romana, 33, pp. 99-136. muttoni g., ravazzi c., breda m., pini r., laj c., kissel c., ma z a u d a. & ga r z a n t i e . (2007) -m a g n e t ostratigraphic dating of an intensification of glacial activity in the southern italian alps during marine isotope stage 22. quaternary research, 6 7, pp. 161–173. na p o l e o n e g., al b i a n e l l i a., az z a r o l i a., be r t i n i a . , ma g i m. & ma z z i n i m. (2003) calibration of the upper valdarno basin to the plio–pleistocene for correlating the apennine continental sequences. il quaternario, 16, pp. 131–166. ol i v e f. (2006) evolution des grands carnivores au plio pléistocène en afrique et en europe occidentale. l’anthropologie, 110 (5), pp. 850–869. pa l o m b o m . r . (2004a) biochronology of the pliopleistocene mammalian faunas of italian peninsula: knowledge, problems and perspectives. i l quaternario, 17 (2/2), pp. 565-58. pa l o m b o m.r. (2004b) guild of large mammals from the pliocene to the late pleistocene in the italian p e n i n s u l a . in baquedano, e. & rubio, s. (eds). homenaje a emiliano aguirre. zona archeologica 4 (2 paleontologia), museo arqueológico regional, madrid: pp. 372 391. pa l o m b o m . r (2007a) which boundary for the quaternary period and pleistocene epoch? the contribution to the debate given by turnover patterns in large mammalian complexes from northwestern mediterranean region. quaternaire, 18(1), pp. 35-53. pa l o m b o m . r . (2007b) large mammal guilds on the italian peninsula from the pliocene to the late pleistocene: new methodological approaches. courier forschungsinstitut senckenberg, 259, pp. 13-46. palombo m.r., azanza b. & alberdi m.t. (2003) italian mammal biochronology from latest miocene to middle pleistocene: a multivariate approach. geologica romana, 36 (2000-2002), pp. 335-368. pa l o m b o m.r & m.p. fe r r e t t i (2005) elephant fossil record from italy: knowledge, problems, and perspectives. quaternary international, 126 –128, pp. 107-136. pa l o m b o m.r & gi o v i n a z z o c . (2006) what do cenograms tell us about mammalian palaeoecology? the example of plio-pleistocene italian f a u n a s. courier forschungsinstitut senckenberg, 256, pp. 215-235. palombo m.r., milli s & rosa c. (2004) remarks on the late middle pleistocene biochronology of the mammalian faunal complexes of the campagna romana. geologica romana, 37 (2003), pp. 13514. palombo m.r. & mussi m. (2001) human presence and faunal evolution in the middle pleistocene of italy. bollettino della società paleontologica italiana, 40 (2), pp. 257-267 palombo m.r., sardella r. (2007) biochronology versus biostratigraphy: a true dilemma or a false trouble? the example of the plio-pleistocene large mammalian faunas from the italian peninsula. quaternary international, 160, pp. 30-42. pa l o m b o m.r., sa r d e l l a r. & no v e l l i m . (2008) carnivora dispersal in western mediterranean during the quaternary. quaternary internationa, 1 7 9 (1), pp. 176-189. pa l o m b o m.r. & va l l i a.f.m. (2005) highlighting the early–middle pleistocene transition in italian and french large mammal faunas: similarities and faunal renewals. in he a d, m.j.& gi b b a r d, p.l. (eds): early–middle pleistocenetransit ions: the land–ocean evidence. geological society, london, special publications, 247, pp. 263-276. partridge t. c. (1997) reassessment of the position of the pliopleistocene boundary: is there a case for lowering it to the gauss-matuyama palaeomagnetic reversal? quaternary international, 4 0, pp. 5–10. pa t e l b.a., gi l b e r t c.g. & er i c s o n k . e . (2007) cercopithecoid cervical vertebral morphology and implications for the presence of theropithecus in early pleistocene europe. journal of human evolution, 52 (2), pp. 113-129. petronio c. & sardella r. (1999) biochronology of he pleistocene mammal fauna from ponte galeria (rome) and remarks on the middle galerian faunas. rivista italiana di paleontologia e stratigrafia, 105 (1), pp. 155-164. petronio c., di canzio e. & salari l. (2007) the late pleistocene and holocene mammals in italy: new biochronological and paleoenvironmental data. palaeontographica abteilung a, 2 7 9 (4-6) , pp. 147-157. ravazzi c. (2003) an overview of the quaternary continental stratigraphic units based on biological and climatic events in italy. il quaternario volume speciale inqua,16(1bis), pp. 11-18. ri o d., sp r o v i e r i r., ca s t r a d o r i d. & di st e f a n o e . (1998) the gelasian stage (upper pliocene): a new unitnof the global standard chronostratigraphic scale. episodes, 21 (1), pp. 82-87. rook, l., mart›nez-navarro, b. & howell, c. f. (2004) occurrence of theropithecus sp. in the late villafranchian of southern italy and implication for early pleistocene “out of africa” dispersals. journal of human evolution, 47, pp. 267–277. ruddiman, w f, raymo, m e, martinson, d g, clement, b m,& backman, j. (1989) pleistocene evolution: northern hemisphere ice sheets and north atlantic ocea. paleoceanography, 4, pp. 353–412. sabato l., bertini a., albianelli a., napoleone g. & pieri p. (2005) the lower and middle pleistocene geologic record of the san lorenzo lacustrine succession in the sant’arcangelo basin (southern apennines, italy). quaternary international, 1 3 1, pp. 59–69. sala b. (1992) i mammiferi del quaternario italiano. in: tugnoli, c. (ed.), i segni del tempo memoria 305biochronology of terrestrial mammals and quaternary subdivisions: ... delle origini ed icone del primordiale. atti del corso di aggiornamento per personale docente, trento, pp. 209–227. sa l a b . (2005) mammalian faunas and environment from the würmian glacial maximum of the italian peninsula (approx. 22±2 ka cal bp). a n n a l i dell’università degli studi di ferrara, museologia scientifica e naturalistica, spec. vol. 2005, pp. 125129. sa l a b. & ma s i n i f . (2007) the late pliocene and pleistocene small mammal chronology in the italian peninsula. quaternary international, 160 (1), pp. 4-16. sa l a b., ma s i n i f., fi c c a r e l l i g., ro o k l. & to r r e d . (1992) mammal dispersal events in the middle and late pleistocene of italy and water europe. courier forsch.-inst. seckenberg, 153, pp. 58-68 sa l a b., ma s i n i f., fi c c a r e l l i g., ro o k l. & to r r e d . (1992) mammal dispersal events in the middle and late pleistocene of italy and water europe. courier forschungs-instituts senckenberg, 1 5 3, pp. 58–68. salvador a. (1994) international stratigraphic guide. a guide to stratigraphic classification, terminology, and procedure, 214 pp., the geological society of america, boulder sardella r. & palombo m.r. (2007) what significance for the wolf event? quaternarie, 18 (1), pp. 65-71 schenck, h.g. & muller, s.w. (1941) stratigraphic terminology. geological society of america bulletin, 52, pp. 1419–1426. schoch r.m. (1989) stratigraphy: principles and methods. van nostrand reinhold, new york, 375 pp. sh a c k l e t o n n.j. (1997) the deep-sea sediment record and the pliocene-pleistocene boundary. quaternary international, 4, pp.33-36. sp a s s o v n . (2003) the plio–pleistocene vertebrate fauna in south-eastern europe and megafaunal migratory waves from the east of europe. revue de paléobiologie, 22 (1), pp. 197–229. su c j.-p. & po p e s c u s.m. (2005) pollen records and climatic cycles in the north mediterranean region since 2.7 ma. in head m j. & gibbard p.l. (eds): early-middle pleistocene transitions: the landocean evidence. geological society of london, special publication, 24, pp. 147–158. su c j.p., be r t i n i a., le r o y s.a.g., & su b a l l y o v a d . (1997) towards the lowering of the pliocene/pleistocene boundary to the gauss/ matuyama reversal. quaternary international, 40, pp. 37-42. tedford, r.h. (1970) principles and practices of mammalian geochronology in north america. american paleontology convenction chicago, lawrence, ks: allen pres, 1969, part. f, pp. 666-703. teichert, c. (1958) some biostratigraphical concepts. geological society of america bulletin, 69(1), pp. 9–120. torre d. (1987) pliocene and pleistocene marine-continental correlations. ann. inst. geol. publ. hung, 70, pp. 71-77 torre d., albianelli a., bertini a., ficcarelli g., masini f. & napoleone g. (1996) paleomagnetic calibration of plio–pleistocene mammal localities in central italy. acta zoologica cracoviensia, 39 (1), pp. 559–570. to r r e d., fi c c a r e l l i g., ma s i n i f., ro o k l.& sa l a b. (1992) mammal dispersal events in the early pleistocene of western europe . c o u r i e r forschungs-institut senckenberg, 153, pp. 51–58. tr i a n t i s k.a., my l o n a s m., li k a k. & va r d i n o y a n n i s k . (2003) a model for the species–area–habitat r e l a t i o n s h i p. journal of biogeography, 3 0, pp. 19–27. wa l s h s.l. (1998) fossil datum and paleobiological event terms, paleontostratigraphy, chronostratigr a p h y , and the definition of land mammal “age” b o u n d a r i e s. journal of vertebrate paleontology, 18 (1), pp. 150-179. williams, h.s. (1901) the discrimination of time values in geology. journal of geology, 9 (7), pp. 570–585. zagwijnw.h. (1974) the pliocene-pleistocene boundary in western and southern europe. boreas, 3, pp. 75-97. 306 ms. ricevuto il 25 novembre 2008 testo definitivo ricevuto il 22 aprile 2009 ms. received: november 25, 2008 final text received: april 22, 2009 m.r. palombo base multi-proxy reconstruction of late pleistocene to holocene paleoenvironmental changes in sw calabria (southern italy) from marine and continental records maria pia bernasconi1, francesco l. chiocci2, salvatore critelli1, mauro f. la russa1, stefania marozzo1, eleonora martorelli2, elena natali3, teresa pelle1, gaetano robustelli1, elda russo ermolli4, fabio scarciglia1 & vincenzo tinè3 1 dipartimento di scienze della terra, università della calabria, arcavacata di rende (cs) 2 dipartimento di scienze della terra, università “sapienza”, roma 3 soprintendenza speciale al museo nazionale preistorico etnografico “l. pigorini”, roma 4 dipartimento di arboricoltura, botanica e patologia vegetale, università di napoli “federico ii”, portici (na) corresponding author: f. scarciglia <scarciglia@unical.it> abstract: bernasconi m.p. et al., multi-proxy reconstruction of late pleistocene to holocene paleoenvironmental changes in sw calabria (southern italy) from marine and continental records. (it issn 0394-3356, 2010). in this work we reconstructed the major climatic changes occurred since the last postglacial transition to the holocene in sw calabria (southern italy). we applied a multidisciplinary approach based on both marine and continental paleoclimatic and paleoenvironmental proxies. in particular, we focused (i) on the effects of eustatic sea-level rise on the submerged continental shelf (interpreted through offshore seismic and core stratigraphy, along with paleoecological and palynological analyses), and (ii) on the geomorphic consequences on land of the main climatic changes and their interplay with late prehistoric to historic human activities (deforestation, cultivation, ploughing, etc.), recorded by soil features in archaeological contexts and pollens in marine cores. in particular, the transgressive and highstand systems tracts that overly the last glacial maximum unconformity surface were reconstructed in detail. they indicate an upward deepening of sedimentary environments followed by overall depth stability, also confirmed by mollusc paleobiocoenoses. geomorphic stability coupled with warm and humid climate characterized the middle holocene, promoting major soil development during neolithic times. important changes in soil features towards the late holocene point to a phase of climatic drying and land degradation (probably during the bronze age, ~4 ka bp), followed by restored prolonged moisture availability alternated with minor warm or dry events. different episodes of intense soil erosion and human impact occurred in this period, with increasing deforestation and cultivation during about the last 2 ka, as testified by soil features and pollen stratigraphy. the consequent marine response can be probably related to seaward progradation of the late holocene sedimentary units, also reflecting river systems adjustment to eustatic base-level rise and highstand. riassunto: bernasconi m.p. et al., ricostruzione multi-proxy delle variazioni paleoambientali dal tardo pleistocene all’olocene in calabria sud-occidentale (italia meridionale) attraverso record marini e continentali. (it issn 0394-3356, 2010). in questo lavoro sono state ricostruite le principali variazioni climatiche avvenute dall’ultima transizione postglaciale all’olocene in calabria sud-occidentale (italia meridionale). è stato applicato un approccio metodologico multidisciplinare basato su indicatori paleoclimatici e paleoambientali sia marini sia continentali. particolare attenzione è stata rivolta (i) agli effetti della risalita eustatica del livello del mare sulla piattaforma continentale sommersa (interpretati attraverso stratigrafia sismica e di carote di sondaggio a mare, unitamente ad analisi paleoecologiche e palinologiche), ed (ii) alla risposta a terra dei processi geomorfici ai principali cambiamenti climatici ed alla loro interazione con le attività antropiche tardo-preistoriche e storiche (deforestazione, coltivazione, aratura, ecc.), registrate nei caratteri pedogenetici dei suoli in contesti archeologici e nei pollini in carote marine. in particolare, sono stati ricostruiti in dettaglio i sistemi trasgressivi e di stazionamento alto sovrastanti la discordanza angolare dell’ultimo massimo glaciale. essi indicano un approfondimento verso l’alto degli ambienti sedimentari, seguito da una generale stabilità della profondità, anche confermati dalle paleobiocenosi a molluschi. condizioni di stabilità geomorfologica e clima caldo-umido hanno caratterizzato l’olocene medio, promuovendo un importante sviluppo del suolo durante il neolitico. rilevanti modificazioni nei caratteri pedogenetici verso l’olocene superiore indicano una fase di inaridimento climatico e di degradazione del suolo (probabilmente avvenuta durante l’età del bronzo, ~4000 anni fa), seguita da un ripristino di condizioni di prolungata umidità, alternata ad episodi minori caldi o aridi. in questo periodo avvengono diverse fasi di intensa erosione del suolo ed impatto antropico, con un incremento della deforestazione e delle coltivazioni grossomodo negli ultimi 2000 anni, come testimoniato dai caratteri dei suoli e dalla stratigrafia pollinica. la conseguente risposta in ambiente di piattaforma può probabilmente essere messa in relazione con la progradazione verso mare delle unità deposizionali tardo-oloceniche, che riflettono anche il riequilibrio dei sistemi fluviali in funzione della risalita eustatica e dello stazionamento alto del livello di base. keywords: seismic and core stratigraphy; paleoecological reconstruction; mollusc; pollen analysis; soil development; late pleistocene to holocene climatic changes; deforestation parole chiave: stratigrafia sismica e di sondaggio; ricostruzione paleoecologica; molluschi; pollini; sviluppo pedogenetico; variazioni climatiche del tardo pleistocene – olocene; deforestazione il quaternario italian journal of quaternary sciences 23(2), 2010 263-270 introduction this paper reports the results of a multidisciplinary study that integrates a wide variety of continental and marine geological and morphostratigraphic data along the tyrrhenian sea margin of calabria, in southern italy. most of the existing literature concerns methods and data that deal with onshore and offshore environments, separately. very little is known about correlations between continental and marine stratigraphic records in the light of morpho-evolutionary reconstructions, i.e. in terms of submerged sedimentary 264 p.m. bernasconi et al. environment responses to geomorphic processes in adjacent onshore catchments. only few papers make such an attempt in the calabria region, focusing on modern sediment composition and provenance, role of eustatic versus tectonic base-level changes on sedimentary/erosive phases during the quaternary, relationships among sea-floor morphologies, seismicity and mass wasting phenomena (le pera & critelli, 1997; le pera et al., 2000; robustelli et al., 2005; rebesco et al., 2009; martorelli et al., 2010). in particular, le pera & critelli (1997) evidence a strict relationship among modern petrofacies of the main river/stream drainage catchments, coastal beaches and marine environments along the northern-central sector of western calabria. they show that marine sediment composition mainly reflects feeding sources from metamorphic and plutono-metamorphic rocks of the coastal range, sila massif and monte poro inland relieves, which can be expected to have controlled also past depositional environments. also the role of river systems interacting with postglacial sea-level rise and marine seismic stratigraphy is explored by martorelli et al. (2010). moreover, robustelli et al. (2005) evidence the interplay between tectonically-induced trenching of alluvial fans debouching from the mountain front of the coastal range and paleovalleys dissected onto the emerged continental shelf during the last glacial sea-level lowering, as pathways for seaward sediment delivery. conversely, they indicate major phases of alluvial fan aggradation during interglacial sea-level rise, possibly coupled with tectonic subsidence, that created suited accommodation space. the role of quaternary climatic changes on sediment production and delivery was also highlighted. in this framework we applied an integrated multidisciplinary approach to characterize the main environmental changes occurred both on the continental shelf and inland during the late pleistocene postglacial transition and the holocene, using different proxies and methods (stratigraphy, palaeontology, palynology, geomorphology, geoarchaeology and pedology). we aimed at a multiproxy interpretation of climatically-driven changes in the main geomorphic processes, trying to correlate data from different morphostratigraphic contexts. moreover, we focused on an attempt to discriminate natural from anthropogenic-induced signals. data and discussion the main climatic and environmental changes since the last glacial maximum through the holocene were reconstructed on the basis of offshore boreholes and seismostratigraphic data in the continental shelf located offshore the paola-briatico sector (along the eastern edge of the coastal range and the s. eufemia plain), a borehole along the present coastline near briatico and onshore pedostratigraphic successions from an archaeological site in the surroundings of palmi (at the southern end of the gioia tauro plain) and from the monte poro plateau, which borders the same plain to the north (fig. 1a). this sector of calabria consists of alternating morphotectonic highs and tectonic depressions, bordered by ne-sw and wnw-ese-trending fault systems (e.g. catalano et al., 2008). the coastal zone preserves a typical sequence of stair-like marine terraces, which testify high uplift rates (miyauchi et al., 1994; balescu et al., 1997; tortorici et al., 2003). the main paleoenvironmental changes occurred in the continental shelf during the considered time span, were reconstructed using seismostratigraphic interpretation and core stratigraphy. the stratigraphic analysis was integrated with paleoecological data obtained from mollusc fossil assemblages and pollen analyses (the latter only performed on clayey deposits). marine deposits show variable characteristics, pattern of depocenter depths and thickness, which indicate significant changes in sedimentation rates, related to differential sedimentary input, accommodation space and tectonic behavior (as also evidenced along northern sectors of the tyrrhenian sea; chiocci et al., 1989; argnani & trincardi, 1993; carboni et al., 2005; martorelli et al., 2010). on the continental shelf, the seismostratigraphic architecture of the shallow subsurface is described by martorelli (2000) and martorelli et al. (2010). it is characterized by a well developed postglacial depositional sequence (pds), lying on a regional erosional unconformity, i.e. the last glacial maximum unconformity (lgm-u), with a maximum age of about 20,000 years bp. the lgm-u is outlined by a high-amplitude reflector which truncates the underlying plio-pleistocene prograding units (fig. 1b). the pds is an incomplete and still evolving depositional sequence made up of both the transgressive systems tract (tst) and the highstand systems tract (hst). the deposits of the pds occur on almost all the continental shelf reaching a notable thickness (up to 65 m) on the inner sector. the tst consists of up to 3 parasequences with a retrogradational stacking pattern, that are laterally confined by the irregularities of the lgm-u. tst deposits are characterized by a number of isolated depocentres. the hst is made up of two parasequences, arranged in a progradational and aggradational stacking pattern. these parasequences are probably of holocene age and are bounded by a non-depositional surface. the lower parasequence lies directly on the maximum flooding surface (mfs) and shows a constant low-amplitude acoustic facies throughout the area. it is generally prograding and the reflectors become concordant with respect to the mfs only on the outer shelf. the upper parasequence shows a variable acoustic facies, especially in its upper part, which varies from a completely transparent facies to a high continuity-high amplitude seismic facies. the distribution of the hst deposits is rather regular with an almost continuous wedge over the entire area. the thickness of hst deposits is maximum (50 ms t.w.t., around 40 m) offshore of the savuto river, the larger fluvial catchment in the study area dissecting the coastal range, north of the s. eufemia plain, and diminishes rapidly seaward. there, the relatively thick (~15 m) upper parasequence is characterized by discontinuous high-amplitude internal reflectors, which may indicate coarser lithologies linked to its river delta. slope breaks, in places revealing terraced surfaces and/or bioherms, that probably represent sea-level stillstands, can be identified at about 3-4 km from the present coastline across the lgm erosional surface. moreover, the latter is incised by deep paleovalleys, some of which developed during exposure of the shelf as a response to glacial sea-level lowering, and subsequently filled and sealed by the holocene sedimentary wedge. well developed transgressive deposits (up to tens of meters thick) made of nearshore sands and gravels, provided a detailed record of the last transgression and highstand (martorelli, 2000; martorelli et al., 2010). in order to correlate these data with those on the land sites, the closer cores collected offshore of briatico were analyzed (4a, 4arip, 6a, 6b, 6brip), ranging in length between 170 and 450 cm (fig. 1c), and compared with the top section of a nearby coastal one (bria 2). these cores clearly show part of the transgressive and highstand deposits. the age of the base of offshore cores ranges from 11326 to 9296 cal. years bp (radiocarbon dates on mollusc shells) in sand and silty sand transgressive deposits, respectively. sometimes, quite dissimilar core stratigraphy depths and/or sedimentary facies even at very short distance, suggest the occurrence of some depositional hiatuses. this feature is highlighted by some much younger radiocarbon dates (as the 2573 cal. years age in core 6a) recorded in the lower-intermediate portion of few cores, very close (~ 60 cm) to the depth of layers dated to about 10 ka. the closeness of these cores to river mouths, feeding important sedimentary input to the shelf environment, might explain the discontinuous sedimentary records. for instance, in core 6a this is also consistent with an opposite trend of sedimentological and paleobiotope data in depth (especially in the upper core section) with respect to those from the other offshore cores. this hypothesis is also supported by a prominent role of steep and high-sloping river catchments located close to the coast, which could have enhanced sediment transport and distribution onto the shelf. 265multi-proxy reconstruction of late pleistocene to ... in the offshore cores paleobiological and sedimentological evidence detect two depositional systems: from core bottom to top, it is noteworthy an upward deepening of the paleobiotope, followed by a phase characterized by a depth stability of the paleoenvironments (marozzo, 2004). molluscan assemblages are interpreted according to the meditrerranean benthic bionomy of pérès & picard (1964) and pèrès (1982). acronyms used to identify mediterranean biocoenoses are derived from their original french names and their english translation as reported in bernasconi & robba (1993). the increasing depth is marked by the replacement of infralittoral epifaunal species strictly related to the biocoenoses of posidonia seagrass (hp) and of photophilous algae (ap), such as bittium reticulatum, obtusella macilenta with those related to the circalittoral biocoenoses of coastal detritic bottoms (dc) and of terrigenous mud (vtc) (timoclea ovata, parvicardium minimum and turritella communis). the depth stability is reached when molluscan assemblages are characterized by high dominance values of kelliella abyssicola, a species strictly related to the biocoenosis of bathyal mud (vp). the transition represents the maximum flooding surface of the transgression, recorded slightly later (upward) than observed in seismostratigraphic data (fig. 1c). the onland core collected near briatico (bria 2) is 8 m in length and is still in study. in its midto upper section (0-5 m) shows, from bottom to top, marine grey clay deposits (~2.5 m thick) overlaid (up to the top) by two moderately-developed, organic-rich, dark brown soils (the lower also exhibiting some illuvial clay coatings within pores), intercalated by centimetreto decifig. 1 location map of the study sites and stratigraphic cores (a); seismic profile passing across core 4arip (b); schematic stratigraphy of selected cores (6a, 6b, 6brip, 4a, 4arip) and radiometric ages (c). see text for details. ubicazione dei siti di studio e dei sondaggi (a); profilo sismico passante dal sondaggio 4arip (b); stratigrafia schematica dei sondaggi selezionati (6a, 6b, 6brip, 4a, 4arip) ed età radiometriche (c). si veda il testo per i dettagli. 266 metre-thick, whitish caco3-concretioned layers, tentatively correlated with the soils described in the archaeological excavations, reported below. the pedostratigraphic succession excavated in the onshore site close to palmi, on a wide terrace at 500 m a.s.l., mainly consists of silt loam soils with some volcanic input and variable morphological features, which can be partly dated on the basis of in situ archaeological settlements and finds. they include well developed, dark yellowish-brown buried argillic (btb) horizons, overlaid by truncated and buried, often artificially reworked, dark brown organic-mineral (ab) horizons (fig. 2a). these layers can be ascribed to about 6500-5800 cal. years bp thanks to the occurrence of late neolithic ceramic artefacts (diana style facies) and typical incineration burials found in biconical vases. they are in turn overlaid and strongly superimposed by a widespread paleosurface related to late early bronze age colonization (about 4000-3700 cal. years bp), which shows similar features to the palma campania and capo graziano archaeological facies defined in other sites of southern italy (e.g. albore livadie, 1999). this surface is affected by many pole holes left by not preserved large wooden huts, ploughed furrows, excavated cisterns, ditches and trenches, often filled with organic-rich dark brown soil material, also filling some large pockets in argillic horizons. also hearths with charcoal remains, burials, vases and other diagnostic ceramic fragments occur. above the bronze age surface, the upper stratigraphic succession consists of brown anthropogenically disturbed organic-mineral (ap) horizons that appear cyclically ploughed during historical times (archaeologically not well dated because of their reworking for agricultural practices), in places disturbing with abrupt irregular boundaries the underlying horizons. the chronological constraints supplied by the archaeological stratigraphy are in agreement with the volcanic glass content identified at the microscopic scale in all soil horizons, using sem-eds analysis (fig. 2b). the dominant rhyolitic composition of volcanic pumices is quite similar to that analyzed in the analogous, widespread andisols (iuss working group wrb, 2006; soil survey staff, 2010) of monte poro upland and gioia tauro plain, which can be related to late pleistocene to holocene volcanic eruption/s from the aeolian islands (aramini et al., 2005; scarciglia et al., 2006). this chronological constraint is also supported by the late palaeolithic to late neolithic and late bronze age archaeological settlements and artefacts found in the volcanic soils of monte poro (pacciarelli, 2008). therefore major soil development probably occurred during most of the holocene (and maybe the late pleistocene). the above soil features, coupled with chemical, physical and mineralogical analyses, as well as micromorphological observations performed on thin sections from undisturbed soil samples (fitzpatrick, 1984), allowed us to propose the following reconstruction. a period of geomorphic stability under warm and humid climatic conditions (with high moisture availability and some seasonal contrast) characterized the latest phases of the neolithic and likely the following initial stages of the bronze age, with important soil development under a stable vegetation cover, that can be related to the upper part of the holocene climatic optimum (cf. scarciglia et al., 2009). this hypothesis is supported by the presence of clay coatings in bt horizons (quite enhanced in warm and humid climates) and by their relict significance (i.e. the present inactivity of illuvial processes) highlighted by micromorphological observations, showing that they often appear fragmented and with smooth-banded to grainy extinction patterns between crossed polars (fig. 2c) (fitzpatrick, 1984; catt, 1989). coherently, the latest phases of important clay i l luviation in temperate mid-latitude and mediterranean environments are well documented just during the holocene climatic optimum (e.g. catt, 1989; scarciglia et al., 2009). the above conditions are further supported by: (i) more abundant phyllosilicate clays detected by x-ray diffractometry in argillic horizons; (ii) overall lower amounts of short-range order minerals (srom) and less developed andic properties (sensu iuss working group wrb, 2006; soil survey staff, 2010), estimated on the basis of field morphological features, ft-ir spectroscopy and the oxalateextracted al and fe index (icomand, 1988). these climatic conditions are quite consistent with the climate amelioration characterized by progressive temperature and moisture increase, documented for the lateglacial and the early-middle holocene (russo ermolli & di pasquale, 2002; carboni et al., 2005; giraudi, 2005; di donato et al., 2008), and the concurrent sea-level rise (approaching the present-day level at about 6-7 ka bp; buccheri et al., 2002; lambeck et al, 2002), also recorded in the offshore cores. this period was followed by a severe land degradation during the bronze age at about 4000 cal. years bp, also identified in many places along the italian peninsula, where a drought phase (tentatively recorded by the carbonate-concretioned layers within the brown soils in the bria 2 coastal core) presumably contributed to the effects of deforestation (e.g. di rita & magri, 2009). this phase is testified by erosion and human impact extensively affecting surface a horizons. on the other hand, it cannot be excluded a relevant role of other dry episodes during the middle-late holocene, such as those at 5.4 and 3-2.3 ka bp, likely related to the global scale rcc events of mayewski (2004) and recently identified by di donato et al. (2008) in the salerno gulf (more than 200 km far to the north). these climatic phases might have prepared and enhanced, respectively, the above land degradation. although no detailed chronological data are available for the whole postglacial depositional sequence, the occurrence of two hst parasequences, their progradational and aggradational stacking pattern, coupled with their maximum thickness offshore of the savuto river, suggest that some relevant changes occurred inland during their emplacement in terms of erosion and sediment delivery within and from the main river catchments seaward. these modifications can be related to adjustment of river systems after mere glacio-eustatic sea-level rise and highstand, possible holocene tectonic uplift (cf. pirazzoli, 2005) though not evidenced by our data, as well as to the effects of human impact in their feeding areas. in particular, the above land degradation during and after the bronze age could be tentatively correlated to progradation of the upper parasequence forming the upper part of the highstand system tract, which very likely represents the p.m. bernasconi et al. 267 late holocene stratigraphic record. we cannot rule out a simultaneous coastline progradation, because no clear morphostratigraphical records are available. nevertheless, the possible coarse-grained delta facies identified in the thick hst upper parasequence offshore of the savuto river may be associated to a late holocene coastline progradation. in addition to anthropogenic impact on land, such fluvial and shelf deposition could be likely related to a transition towards higher moisture availability in soils (subsequent to the above drought phase), which also underwent repeated, undetermined phases of ploughing throughout the late holocene. in fact, andic properties appear more developed in a horizons, where abundant short-range order aluminosilicates are associated with minor phyllosilicates (as also supported by their dominant isotropic matrix in crossed polarized light), which suggests the occurrence of a regime with prolonged (and overall seasonally poorly-contrasted) moisture availability. this phase might be at least partly related to temperate cooling events during the last 3000 years, characterized by minor warm or dry episodes, as testified by higher lake levels or burial of soils by glacial/periglacial deposits in central italy and glacier expansions in the alps (giraudi, 2005, 2007). on the other hand, the effects of soil degradation, deforestation and agricultural practices are highlighted by truncation of late prehistoric fertile a horizons, once developed at surface under particularly suited climatic conditions (the above neolithic optimum) and vegetation cover, but nowadays not completely preserved in situ. the organic-rich filling of soil pockets in the argillic horizons and more extensively of ploughing furrows and artificial excavations, likely represents the eroded material. moreover, a horizons include some reddishyellow, subrounded pedorelicts exhibiting fragments of clay coatings, probably stripped away from the underlying bt horizons by erosion or ploughing activities. also the pollen analysis evidenced a drastic change in the vegetation cover, presumably caused by this anthropogenic land degradation, which probably went on even during more recent times. an extremely severe reduction of arboreal taxa typical of the mediterranean fig. 2 soil profile in the archaeological excavation close to palmi (a): the upper dashed line represents the late early bronze age paleosurface (~4000-3700 cal. years bp) affected by clear ploughing traces, also involving younger overlying disturbed ap horizons; all the underlying soil layers, i.e. buried organic-mineral (ab) horizons and argillic (bt) horizons, date to late neolithic (~6500-5800 cal. years bp); sem image of a volcanic micropumice and associated eds spectrum from the lower ap horizon of the profile (b); microphotograph showing fragmented and smooth-banded clay coatings from horizon 2btb2 in crossed polarized light (c). profilo pedologico nello scavo archeologico vicino a palmi (a): la linea tratteggiata superiore rappresenta la paleosuperficie del tardo bronzo antico (~4000-3700 anni fa) interessata da tracce di aratura ben evidenti, che coinvolgono anche i sovrastanti orizzonti ap; tutti i livelli pedologici inferiori, cioè gli orizzonti organico-minerali sepolti (ab) ed argillici (bt), sono databili al neolitico finale (~6500-5800 anni fa); immagine al sem e relativo spettro eds di una micropomice vulcanica dall’orizzonte ap inferiore del profilo (b); microfoto mostrante pellicole d’argilla frammentate ed a bande sfumate dall’orizzonte 2btb2 in luce polarizzata incrociata (c). multi-proxy reconstruction of late pleistocene to ... 268 mesophilous forest is observed in two cores located offshore of briatico, at the base and in the middle of the clayey portion from cores 6brip (~118 cm) and 4a (~147 cm), respectively. this deforestation is followed and partly accompanied by the onset of cultivations, which are clearly recorded in the upper part of these two cores, mainly in 6brip (fig. 3). the start of deforestation and of intensive olive cultivation was already pointed out in the salerno gulf and dated to the early middle ages (russo ermolli & di pasquale, 2002). here, the increase of brassicaceae at the core top should represent the cabbage cultivation, which was one of the most common orchard product during the roman age, as testified in the sediments of the ancient roman harbour of naples (1st century bc 5th century ad; allevato et al., 2009; amato et al., 2009). on this basis, despite the lack of definite chronological constraints for these cores, a late holocene time span can be supposed for the analyzed pollen record. it might be tentatively related to about 2000 yr bp in core 6brip (also consistent with the above discussed hypothesis of local sedimentary hiatuses) and possibly to some thousands before in core 4a, where a longer stratigraphic record is included and evidence of deforestation starts only in the mid clayey section. this interpretation is also supported by clear evidence of deforestation and cultivation during about the last 2 ka from another site in calabria, i.e. in the nearby sila massif upland (pelle et al., 2010 and references therein), and a further one in the basilicata region, still in southern italy (allen et al., 2002). in addition to these environmental changes, previous climatic fluctuations could have occurred during the early holocene (and/or the late pleistocene), as revealed by the main features of deeper soils underlying and predating the above archaeological layers (occasional grey glosses and blackish mottles of btg horizons caused by partially impeded drainage and transient reducing conditions, in turn overlying another andic-like a horizon). conclusions the integrated study of seismic profiles, stratigraphic cores and soil profiles located offshore and onshore of the tyrrhenian sea coast of calabria (southern italy) allowed the reconstruction of the main late pleistocene to holocene environmental changes. based on a number of proxies, we identified the major responses of geomorphic processes to changing climatic conditions and human activities. seismostratigraphic interpretation and core stratigraphy, coupled with paleoecological analyses, provided a detailed record of the holocene maximum flooding surface and highstand depositional units of the last marine transgression, which overly the last glacial maximum unconformity. the lateglacial to early holocene climatic amelioration that caused such a sea-level rise, culminated into the mid-holocene (neolithic) climatic optimum, characterized by warm and humid conditions and geomorphic stability, promoting important soil formation under a stable vegetation cover. the variability in depth of andic properties, phyllosilicate formation and illuvial pedofeatures in holocene soils suggests climate changes probably occurred at the transition from the climatic optimum to the cooler but still humid upper holocene, after one or more periods characterized by drought, land degradation, severe soil erosion and human impact during and after the bronze age. this phase was presumably coupled with deforestation and agricultural practices likely more intense during the last 2 ka, clearly highlighted by soil features and pollen analysis in marine cores. references albore livadie c., 1999 archeologia e storia del passato. il bronzo antico. in: fedele f. & petrone p.p. (eds.), un’eruzione vesuviana 4000 anni fa. fridericiana editrice universitaria, napoli, 33-42. fig. 3 pollen spectra from core 6brip. spettri pollinici della carota 6brip. p.m. bernasconi et al. allen j.r.m., watts w.a., mcgee e. & huntley b., 2002 holocene environmental variability – the record from lago grande di monticchio, italy. quaternary international 88, 69-80. allevato e., di pasquale g., russo ermolli e., 2009 a shipwreck from the neapolis harbour: timberwoodland relationship. in: amato v., marriner n., morhange c., romano p., russo ermolli e. (eds.), geoarcheology in italy. méditerranée 112, 33-42. amato l., carsana v., cinque a., di donato v., febbraro s., giampaola d., guastaferro c., irollo g., morhange c., romano p., ruello m.r., russo ermolli e., 2009 the natural evolution and the human settlements in the coastal landscape of naples (italy): from the post-glacial submersion to the greek-roman times and the middle ages. in: amato v., marriner n., morhange c., romano p., russo ermolli e. (eds.), geoarcheology in italy. méditerranée 112, 23-31. aramini g., colloca c., corea a.m., de rosa r., iamarino m., mileti a., paone r., scarciglia f., terribile f., vergata m., vingiani s., 2005 gli andosuoli della piana di gioia tauro e monte poro. in: colloca c., odierna p. (eds.), suoli e paesaggi fra le piane di gioia tauro e di lamezia terme. antichi insediamenti, attualità produttive e potenzialità di valorizzazione. vii ediz. incontri pedologici ital iani ( ipi), società ital iana di pedologia (sipe), calabria, 10-12 settembre 2005, 1-24. argnani a. & trincardi f., 1993 growth of a slope ridge and its control on sedimentation: paola slope basin (eastern tyrrhenian margin) . international association of sedimentologists, special publication 20, 467-480. balescu s., dumas b., guérémy p., lamothe m., lhénaff r., raffy j., 1997 thermoluminescence dating tests of pleistocene sediments from uplifted marine shorelines along the southwest coastline of the calabria peninsula (southern italy). palaeogeography, palaeoclimatology, palaeoecology 130, 25-41. bernasconi m.p. & robba e., 1993 molluscan palaeoecology and sedimentological features: an integrated approach from miocene meduna section, northern italy. palaeogegraphy, palaeoclimatology, palaeoecology 100, 267-290. buccheri g., capretto g., di donato v., esposito p., ferruzza g., pescatore t., russo ermolli e., senatore m.r., sprovieri m., bertoldom m., carella d., madonna g., 2002 a high resolution record of the last deglaciation in the southern tyrrhenian sea: environmental and climatic evolution. marine geology 186(3-4), 447-470. carboni m.g., bergamin l., di bella l., landini b., manfra. l., vesica p., 2005 late quaternary paleoclimatic and paleoenviromental changes in the tyrrhenian sea. quaternary science reviews 24(18-19), 2069-2082. catalano s., de guidi g., monaco c., tortorici g., tortorici l., 2008 active faulting and seismicity along the siculo–calabrian rift zone (southern italy). tectonophysics 453, 177-192. catt j.a., 1989 relict properties in soils of the central and north-west european temperate region. catena supplement 16, 41-58. chiocci f.l., d’angelo s., orlando l., pantaleone a., 1989 evolution of the holocene shelf sedimentation defined by high resolution seismic stratigraphy and sequence analysis (calabro-tyrrhenian continental shelf). memorie società geologica italiana 48, 359-380. di donato v., esposito p., russo ermolli e., cheddadi r., scarano a., 2008 coupled atmospheric and marine palaeoclimatic reconstruction for the last 35 kyr in the sele plain–gulf of salerno area (southern italy). quaternary international 190, 146157. di rita f. & magri d., 2009 holocene drought, deforestation and evergreen vegetation development in the central mediterranean: a 5500 year record from lago alimini piccolo, apulia, southeast italy. the holocene 19(2), 295-306. fitzpatrick e.a., 1984 micromorphology of soils. chapman and hall, london, 433 pp. giraudi c., 2005 middle to late holocene glacial variations, periglacial processes and alluvial sedimentation on the higher apennine massifs (italy). quaternary research 64, 176-184. giraudi c., 2007 le variazioni climatiche in italia centrale negli ultimi 10.000 anni. in: wezel f. (ed.), variabilità naturale del clima nell’olocene ed in tempi storici: un approccio geologico. quaderni della società geologica 1, 18-24. icomand, 1988 circular letter no. 10. international committee on the classification of andisols. new zealand soil bureau, lower hutt, new zealand. iuss working group wrb, 2006 world reference base for soil resources 2006 – a framework for international classification, correlation and communication. world soil resources report 103, fao, rome. 132 pp. lambeck k., yokoyama y. purcell t., 2002 into and out of the last glacial maximum: sea level change during oxygen isotope stages 3 and 2 . quaternary science reviews 21, 343-360. le pera e. & critelli s., 1997 sourceland controls on the composition of beach and fluvial sand of the northern tyrrhenian coast of calabria, italy: implications for actualistic petrofacies. sedimentary geology 110, 81-97. le pera e., mongelli g., morelli f., critelli s., 2000 petrographical and geochemical signature of provenance in modern sediments from the tyrrhenian continental shelf, calabria, italy. giornale di geologia 62, serie 3, 37-55. marozzo s., 2004 analisi paleoecologica dei depositi marini pleistocenici ed olocenici presenti sulla piattaforma continentale del margine tirrenico calabrese. phd thesis, university of calabria, cosenza, italy, 233 pp. martorelli e., 2000 evoluzione recente di due settori tettonicamente attivi del margine continentale tirrenico, ricostruita mediante analisi comparata di dati geofisici ad alta risoluzione e campionamenti mirati. phd thesis. university of rome “la sapienza”, rome, italy, 196 pp. martorelli e., chiocci f.l., orlando l., 2010 imaging continental shelf shallow stratigraphy by using different high-resolution seismic sources: an exam269multi-proxy reconstruction of late pleistocene to ... ple from the calabro-tyrrhenian margin (mediterranean sea). brazilian journal of oceanography 58 (special issue, igcp526), 55-66. mayewski p.a., rholing e.e., stager j.c., karlén w., maasch k.a., meeker l.d., meyerson e.a., gasse f., van kreveld s., holmgren k., lee-thorp j., rosqvist g., rack f., staubwasser m., schneider r.r., steig e.j., 2004 quaternary research 62, 243-255. miyauchi t., dai pra g., sylos labini s., 1994 geochronology of pleistocene marine terraces and regional tectonics in the tyrrhenian coast of south calabria, italy. il quaternario – italian journal of quaternary sciences 7(1/a), 17-34. pacciarelli m., 2008 il popolamento della calabria meridionale tirrenica nelle età dei metalli. in: sensi sestito g. (ed.), la calabria tirrenica nell'antichità. nuovi documenti e problematiche storiche, atti del convegno, rende 2000, soveria mannelli, italy, 77-94. pelle t., scarciglia f., robustelli g., allevato e., di pasquale g., mitro r., marino d., 2010 multidisciplinary study of holocene soils in the archaeological sites of cecita lake (sila massif, calabria, italy): paleoenvironmental reconstruction. atti del convegno “scienze naturali e archeologia il paesaggio antico: interazione uomo/ambiente ed eventi catastrofici”, napoli, 14-16 ottobre 2010, aracne, roma, 183-187. pérès j.m., 1982 major benthic assemblages. in: kinne o. (ed.), marine ecology, wiley, chichester, 373-522. pérès j.m. & picard j., 1964 nouveau manuel de bionomie benthique de la mer méditerranée. receuil des traveaux de la station marine d’endoume 31, 1-137. pirazzoli p.a., 2005 a review of possible eustatic,isostatic and tectonic contributions in eight lateholocene relative sea-level histories from the mediterranean area. quaternary science reviews 24(18-19), 1989-2001. robustelli g., muto f., scarciglia f., spina v., critelli s., 2005 eustatic and tectonic control on late quaternary alluvial fans along the tyrrhenian sea coast of calabria (south italy). quaternary science reviews 24(18-19), 2101-2119. rebesco m., neagu r.c., cuppari a., muto f., accettella d., dominici r., cova a., romano c., caburlotto a., 2009 morphobathymetric analysis and evidence of submarine mass movements in the western gulf of taranto (calabria margin, ionian sea) . international journal of earth sciences (geol. rundsch.) 98, 791-805. russo ermolli e. & di pasquale g., 2002 vegetation dynamics of southweastern italy in the last 28000 yr inferred from pollen analysis of a tyrrhenian sea core. vegetation history and archaeobotany 11(3), 211-220. scarciglia f., de rosa r., aramini g., colloca c., corea a.m., iamarino m., mileti a., paone r., terribile f., vergata m., vingiani s., 2006 provenienza e caratteri pedogenetici di suoli vulcanici lungo la costa tirrenica della calabria meridionale. abstract and poster, convegno aiqua – ingv: “tefrostratigrafia del quaternario recente tra vulcanologia e scienze del quaternario”, roma, 21-23 giugno 2006, 57-58. scarciglia f., robustelli g., tiné v., la russa m. f., abate m., pezzino a., 2009 the role of human impacts and holocene climate change in the santuario della madonna cave (calabria). in: amato v., marriner n., morhange c., romano p., russo ermolli e. (eds.), geoarcheology in italy. méditerranée 112, 137-143. soil survey staff, 2010 keys to soil taxonomy, 11th edit., usda-natural resources conservation service, washington dc, 338 pp. tortorici g., bianca m., de guidi g., monaco c., tortorici l., 2003 fault activity and marine terracing in the capo vaticano area (southern calabria) during the middle-late quaternary. quaternary international 101-102, 269-278. 270 ms. ricevuto il 23 giugno 2010 testo definitivo ricevuto il 21 novembre 2010 ms. received: june 23, 2010 final text received: november 21, 2010 p.m. bernasconi et al. available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 31 (2), 2018, i i quaternary and urban geology adele bertini, maria gabriella forno in the italian peninsula, cities and towns are very complex systems where both environmental and social dynamics interact. urban geology gains insight into earth surface processes by means of a variety of disciplines such as geomorphology, engineering geology, environmental geology, economic geology and hydrogeology. at the same time it proposes strategies for the sustainable use of subsurface resources in urban contexts. on december 15, 2017 at the dipartimento di scienze della terra of florence (italy) aiqua set up a meeting between specialists involved with the various issues of quaternary urban geology. the meeting day focused on the state of knowledge and on the prospects for development and implementation of urban sustainability policies, under non-emergency circumstances but rather for the purpose of prevention. the meeting, which was chaired by a. bertini, m. coli and g. forno, included three invited lectures and eight free oral communications. this volume of amq contains eight of the contributions presented at that meeting. together with the discussions and the final round table, these talks represent aiqua’s first integrated contribution on urban geology in italy. the papers focus on both metropolitan cities, such as rome and turin, and smaller towns; two analyses were directed to unique places such as matera (european capital of culture 2019) and perugia. key case studies address specific urban geology issues; these include in-depth geological and geomorphological analyses focused on different depositional (e.g. volcanic sediments, marine deposits, continental gravels) and morphological (flat, hilly or steep) contexts. the presence of a high number of historically and monumentally valuable archaeological sites in these studies shows how urgent is the need for the implementation of geoscientific teamwork aimed at developing integrated geoarchaeology. the final contribution in the volume is devoted to the use and management of renewable energies, especially geothermal energy. this paper stresses the importance of geosciences for sustainability calls, especially in cities overcrowded with people. all the papers of this volume show that the knowledge of the subsurface and awareness of geoscience issues are vital to the preservation of urban landscape. this expertise contributes to our resilience to natural hazards (e.g. flooding, ground instability, drought) as well as to the development of strategic land-use planning. in this perspective taking early actions to identify actual and potential problems, in urban context, is crucial to effectively face the challenges, which also have economic and social implications. the associated editors take the opportunity to thank all the contributors to this volume. we also thank the many colleagues who reviewed the volume as well as the editor-in-chief of aqm who assisted us with this special issue. the associated editors adele bertini and m. gabriella forno ii amq2018 31(2) 111-118 benvenuti et al available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 31 (2), 2018, 111 118 1. introduction geoarchaeology is based on a set of disciplines and methods of the earth sciences exploited for reconstructing how the environmental setting influenced and was modified by ancient human occupation of the territory and the physical processes that brought to the formation of an archaeological site (butzer, 1971). in this perspective geoarchaeology is often perceived as a discipline solely functional to the archaeological studies. nevertheless, the interaction between geosciences and archaeology opens to wider potential meaning and application, exploring the stratigraphical record to understand how ancient human communities adapted to and controlled the dynamic environment. the geoarchaeological evidence, thus, may provide arguments for a rational planning of present and future land occupation, particularly in highly urbanized areas sensitive to both growing human pressure and the wide range of geomorphic hazards. we summarize here two case studies discussed in detail in previous papers and dealing with the adaptation of urban communities settled between the 3rd century b.c. and the 5th century a.d. in central italy (pisa-san rossore site, benvenuti et al., 2006; mariotti-lippi et al., 2007) and on the southern coast of oman (sumhuram site, mariotti-lippi et al., 2011). the related urban centres were places of intense commercial activity connected to the trading network of the mediterranean basin, red sea and indian ocean as revealed by geoarchaeological (gorain & morhange, 2001; marriner & morhange, 2007; morhange et al., 2016) and archaeological (schiettecatte, 2012; seland, 2014) studies on the ancient harbours located along their coasts 2. the geoarchaeology of the two sites 2.1. the etruscan-roman pisa-san rossore ship site the exceptional and unexpected vestiges of an urban fluvial wharf were casually discovered in the late 1998 in the shallow subsoil of pisa (central italy) on the coastal plain of the arno and serchio rivers (fig. 1a; bruni, 2000; 2002). this lowland, shaped by the late holocene fluvial dynamics, bounds at the surface a clastic infill up to 100 meters thick accumulated during the https://doi.org/10.26382/amq.2018.07 the message from the urban sedimentary archives: examples from the roman pisa-san rossore (central italy) and pre-islamic sumhuram (southern oman) archaeological sites marco benvenuti 1, marta mariotti-lippi 2 , pasquino pallecchi 3 1 dipartimento di scienze della terra, università di firenze, italy 2 dipartimento di biologia, università di firenze, italy 3 soprintendenza archeologia, belle arti e paesaggio per la città metropolitana di firenze e le province di pistoia e prato, italy corresponding author: m. benvenuti <ma.benvenuti@unifi.it> abstract: in this paper we summarize and compare results of previous geoarchaeological studies on urban environments carried out by the authors in central italy (pisa-san rossore) and southern oman (sumhuram). the aim is exploring the strategy of human adaptation to coastal settings selected for founding still existing (pisa) or vanished (sumhuram) urban centres, during the climate warming of the roman age. under warm climatic conditions, despite their distant locations, these urban areas were both devoted to commercial exchanges. the pisa-san rossore was a suitable fluvial wharf based on a pre-existing channel and serving the roman pisa, whereas sumhuram was a pre-arabic strategic trading outpost founded on the rocky coast facing the gulf of aden by people coming from the southern yemen. the stratigraphic, sedimentologic and palynologic data collected in the two sites allowed the identification of the effects of a warm climate, expressed by hydrological events. at pisa-san rossore these were recurring catastrophic overbank floods generated by channel instability of the arno river adjacent to the wharf area. despite the high hydraulic hazard, the local people exploited the site up to its definitive siltation, a behaviour hinting to resilience and calculated risk with respect to the economic advantage. at sumhuram, an enhanced monsoon circulation, over southern oman, between the second century b.c. and the first century a.d., sustained a moisture higher than in preceding and following phases of town existence. this condition favoured the maximum commercial and cultural flourishment of the town. the two case studies indicate that geoarchaeology is a suitable tool for assessing the strategy of resilience and exploitation of the land surface by humans across rapid environmental changes as those occurring nowadays and expected in the near future. the value of the knowledge acquired through a geoarchaeological approach goes beyond the reconstruction of ancient human patterns; it provides contributions for establishing present and future sustainable relations between humanity and the earth learning from the past. keywords: rome (italy), urban geomorphology, urban landscape, tiber river, aqua mariana, nodicus river. keywords: geoarchaeology, community adaptation, roman age, central italy, southern oman 112 benvenuti m. et al. last glacial lowstand of sea level and the following transgression (aguzzi et al., 2005; 2007). an excavation on a surface of about 3000 m2 done for a new building of the italian railways company and located few hundred meters west from the leaning tower (fig. 1b), unexpectedly intercepted several shipwrecks (fig. 1c) and a huge amount of varied materials related to the ships’ cargoes. the excavation (fig. 2), deepened at about 5 meters below the topographic surface, revealed at its southern end the remain of a wood palisade and other materials radiometrically bracketed between the 9th and the 2nd century b.c. (belluomini et al., 2004; martinelli & pignatelli, 2008). together with the remains from the central and northern areas of the site, encompassing the whole roman age (from about the 1st century b.c. to 5th early 6th century a.d.; bruni, 2003; camilli, 2005), the archaeological record attests to the exploitation lasted for a millennium of an urban harbour evidently strategic for the economy of the ancient pisa but unknown until its casual discovery. several sections, made available for the recovery of the shipwrecks and related materials, allowed to define a stratigraphic architecture consisting of five sedimentary units (u0 to u4; fig. 2) encasing the archaeological remains and mostly made of sand with subordinated mudstone (benvenuti et al., 2006). u0, scarcely exposed in the southern-central areas of the site, represents a complex sand-rich body encasing late etruscanroman materials. u1-4, well exposed in the sections of the central-northern areas of the site, consist of crossstratified coarse-medium sands predominantly dipping to northwest (fig. 1d) and bearing entire ships oriented transversally to the dip direction of cross beds. the latter are in turn covered by thin blankets of laminated sandy silts and clays rich in vegetal debris (fig. 1e). each unit, therefore includes a thicker coarse-grained portion, bearing the large-size materials ranging from entire ships to amphorae, capped by a veneer of fine-grained sediments. this lithological alternation attests to a fluctuating regime of sediment transport and deposition, the latter referred to as many pulses of catastrophic floods sweeping away the ships from their berths and dispersing their cargos in the sandy sediment load. these floods resulted from the crevassing of an adjacent active river channel, actually the arno river still today located one-kilometer ca south of the site. the overbank floodwater funneled by crevasse channels spread into an abandoned channel, exploited as a wharf, where deposited sedimentary lobes frontally accreting toward nw. this relic of a pre-existing river course, beheaded by a channel avulsion, was evidently still connected to the sea located about three kilometers from the roman pisa (pranzini, 2001). such a slack-water way favored the suitable transit of a fleet of small ships transporting goods and people from and to the town. shallow cores drilled in the site and in the immediate surroundings, allowed to reconstruct the local environmental setting beyond the limits of what directly observable in the site. fig. 1 a) schematic geological map of the terminal plain of the arno and serchio rivers with location of the pisa-san rossore site; b) oblique aerial view of the pisa downtown: the archaeological site is adjacent to the famous piazza dei miracoli with its leaning tower (on the right in the photograph); c) a well-preserved ship unearthed for recovery; d) detail of cross-stratified sandstone of u1 bearing a fragmented amphora belonging to the ship’s cargo; e) the vegetal debris-rich mudstone draping the sandy cross strata of u1; 113 urban sedimentary archives of pisa and sumhuram the core stratigraphy (fig. 2) indicates that the established units are confined into a concave-plane lens encased in mudstones, confirming the channelized nature of the deposits. the basal mudstones are the infill of a lagoon which occupied the pisa plain during the early holocene as the consequence of a post-glacial rise of sea level and subsequent flooding of the coastal areas (benvenuti et al., 2006). the overlying mudstone represent post-roman-modern floodplain deposits. the channel was incised after about 6,000 years ago as indicated by the radiocarbon age of cerastoderma shell from the top of the underlying lagoonal mudstones (benvenuti et al., 2006). the core correlation suggests that the channel was deeper toward north suggesting a meandering geometry (fig. 2). pollen analyses performed on samples collected in the muddy deposits of the different units (mariotti-lippi et al., 2007 for details) showed: 1) significant percentages of abies and fagus in the pre-roman sediments of u0 pointing to the cold-temperate climate of the etruscan period; 2) the presence of mixed oak woodland taxa, in the muddy deposits capping u1-4 in agreement fig. 2 distribution of the ships and other archaeological material unearthed in the early 1999 and associated to u0-4 (benvenuti et al., 2006). the geologic section a-b is based on cores stratigraphy integrating the limited exposures created by the archaeological excavation. the cal c14 age in core 4 is relative to the dating of a cerastoderma shell. with the roman warm period. the occurrence of hygrophilous plants in pollen spectra dominated by herbs increasing from u1 to u4, accounts for soil waterlogging in the plains surrounding the site throughout the roman age. 2.2. the pre-islamic sumhuram citadel the sumhuram walled citadel, located on the southern coast of the sultanate of oman (dhofar region; fig 3a), was founded by people coming from the reign of hadramawt in southern yemen. the urban settlement on this coastal area, close to the founder’s homeland, was motivated by a strategic position for controlling the commercial exchanges between the mediterranean and india. a particularly important commodity for long-range trading controlled by sumhuram was the frankincense extracted by the tree boswelia sacra thriving in the interior of southern oman (raffaelli et al., 2011). the town’s development occurred into three distinct phases (avanzini & sedov, 2005). during phase 1 (third to first century b.c.) the town flourished under widespread commercial exchanges, as documented by a variety of mediterranean and indian handicrafts recovered from the related archaeological horizons. a short-lived abandonment with possible partial destruction of the town, occurred between the late first century b.c. and the early first century a.d. the following phase 2 (first to third century a.d.) and phase 3 (third to fifth century a.d.) were characterized by town development until its definitive abandonment with the onset of the islamic occupation. five constructional stages succeeded during the town lifetime as documented by a detailed analysis of the buildings (buffa & sedov, 2008). the citadel (fig. 3b), stands at about 25 m a.s.l. on the left bank of the wadi darbat-fed khor rori estuary (fig. 3c), presently barred at its mouth by a sand shoal. the location is on a flat erosional surface sculpted onto paleogene limestones which also form the ne-sw trending escarpment of the jabal al qara, a mountain range up to 2000 meters high separating the arid interiors from the dhofar coastal lowland (fig. 1a). this physiography accounts for a summer monsoonal moisture along the dhofar coast sheltered by the jabal al qara escarpment and favouring the development of permanent vegetation, a peculiarity in south arabia. in the late 2006 a specific section (a68; fig. 3d) was made available thanks to the archaeological excavations done in the frame of the activities carried out by the italian mission to oman (avanzini, 2008). the section, located in the nw part of the town at the end of a narrow street between the houses (fig. 4a), was described and sampled respectively for the deposits stratigraphy and sedimentology and for a high-resolution palynological analysis (mariotti lippi et al., 2011). the site stratigraphy is characterized by the alternation of two main types of deposits (fig. 4d) for a total thickness of about three meters. anthropogenic deposits (ad) consist of a chaotic mix of debris including angular clasts of limestone, brick fragments, charcoal and ash and organic remains mostly represented by terrestrial vertebrate and fish bones. waterlain deposits (wd) are made of centimeter thick beds of sandy loam grading upward into silt loam occasionally bearing granulae and small pebbles. in terms of accumulation processes, ad is referred to deliberate dumping of domestic garbage in the streets of the town, mixed with occasional rock fragments possibly resulting from wall wasting. wd accumulated by waning flow of water running along the streets that can be referred both to intentional discharge or to surface run-off from heavy rainfall. the alternation of ad and wd characterizes three distinct stratigraphic units (fig. 4b) with the basal and topmost units 1 and 3 dominated by ad and the intermediate unit 2 characterized by a prevalence of wd. the integration of radiocarbon chronology and archaeological evidence indicates that units 1-2 and unit 3 developed during phases 1-2 and 3 respectively. a charcoal in the wd-dominated unit 2 (fig. 4a) yielded a calibrated radiocarbon age of 210 b.c.±10 a.d. (2) corresponding to the late phase 1 when the town experienced a great commercial and economic flourishment. a fine sampling of ad and wd along the section allowed a detailed palynological analysis resulting in the recognition of different pollen groups attesting to variable distance of pollen transport (fig. 4c). the short distance group (0-5 km) represents the plants still growing today on the beach and the margins of the coastal plain as well as hygroand hydrophilous plants of the estuaries and wadis. the medium distance group (about 5-25 km) includes plants growing on the inner plain at along the jabal al qara escarpment. the long-distance group (>100 km) represents the plants growing in the oman desert areas, on the mountains of yemen up to those growing in africa and/or in the mediterranean area and beyond. the distribution of the pollen record in the three units shows a relative abundance of the longdistance group in the wd of unit 2, being indicative of a greater strength of the monsoonal circulation during the development of this unit than of units 1 and 3. 3. discussion and conclusions the geoarchaeological analysis of the two sites, selected for settling towns, provides arguments for assessing the adaptation strategies to different coastal settings under the influence of an overall warm climate. the pisa-san rossore site offers a picture of an alluvial environment adjacent to an urban center that concurrently favored and conditioned the human occupation and the related activities. in this perspective the site records the human interaction with active geomorphic processes, such as floods, competing with an urban development. the sedimentological and stratigraphic lines of evidence, joined to the palynological data collected in u1-4, point to the succession of four major stages of catastrophic alluvial events (fig. 5) occurred during the roman age which caused a marked channel instability of the terminal arno river reach. this instability resulted in the repeated channel crevassing and flood invasion of an adjacent abandoned channel exploited as a natural dockyard strategic for the commercial exchange from and to the roman pisa. these catastrophic events occurred under the influence of a warm climate following to and preceding the iron age and early middle age cold periods respectively (lamb, 1996). the climate 114 benvenuti m. et al. 115 fig. 3 a) physiography of the dhofar region of southern oman with annotated geology. the location of the sumhuram town is shown; b) panoramic view of sumhuram looking toward the outlet of the khor rhori estuary barred by a sand shoal; c) topography of the area including sumhuram; d) detail of the sumhuram structure with location of section a68 urban sedimentary archives of pisa and sumhuram regime was characterized by a monsoon-like mode of rainfall distribution determining high-magnitude and/or frequent floods in the river catchments of central italy (fig. 5; benvenuti et al., 2006). the sumhuram site provides a different scenario emerging form the geoarchaeological record. this tells about the ordinary life inside an urbanized trading outpost punctuated by non-anthropic physical processes leaving subtle traces in the record. the wd layers of unit 2 attest to street flooding episodes washing the garbage debris and leaving thin graded layers. the palynologic signature of the wd (fig. 4c), characterized by a relative abundance of pollen indicative of a wetenvironment vegetation together with long-distance pollens, support an hypothesis of occasional running water along the streets related to monsoon-driven heavy rainfall rather than to the intentional discharge of water by the inhabitants. finally, this sedimentary record is a proxy of a fluctuating monsoonal influence over the site during the three phases of urban development. the 116 fig. 4 a) view of section a68 logged for the stratigraphy and sampled for palynological analysis (mariotti lippi et al., 2011): two cal c14 dates obtained from charcoal within the succession are shown; b) the subdivision of the stratified deposits in the section in ad (anthropogenic deposits) and wd (waterlain deposits) layers in turn grouped in the three units; c) the pollen spectra reconstructed for the three units; d) details of ad and wd alternation in unit 2, the meter rod for scale. benvenuti m. et al. effect of the warm climate that characterized the period between the first century b.c. and the first century a.d. in this interval the urban wharf of pisa was affected by catastrophic floods which destroyed ships and dispersed their cargoes never recovered, as indicated by the archaeo-sedimentary record of u1. in the meantime, sumhuram experienced the end of its maximum flourishment during phase 1. given the record of a stronger monsoon circulation over southern oman between the second century b.c. and the first century a.d., the development of the settlement was supported by higher seasonal rainfall in turn causing also more continuous discharge of the wadi darbat. the latter allowed the khor rhori estuary to be opened to the sea, differently from the present clogging by a sand shoal, favouring the establishment of an harbour at the town footslope (avanzini, 2011). in conclusion, what was a threat for pisa, differently was an opportunity for sumhuram. the respective communities cohabited with the dynamic physical conditions until the sites abandonment. flood after flood, the pisa wharf underwent a complete silting being exploited for its economic suitability besides the recurrent destruction. the sumhuram people after the first century a.d. experienced a progressively drier climate that evidently interacted with political and economic events bringing to the fall and abandonment of the town. a reduced moisture over the area may have shrunk the availability of freshwater and as occurring today, determined the clogging of the estuary outlet, a condition that prevented the monsoon circulation was stronger during the development of unit 2 than during the formation of units 1 and 3 dominated by anthropogenic deposition (mariotti lippi et al., 2011). the two discussed sites, located about 5,000 km apart, witnessed a dense human occupation and intense activities mostly related to commercial exchanges across the mediterranean sea, the red sea and the indian ocean. the physical settings selected by the respective communities where significantly different besides both facing coastal areas. the pisa-san rossore was a functional place for the development of the roman pisa, a town settled on the terminal plain of the arno and serchio rivers. the latter, as today, were perennial streams fed by relatively large catchments and subjected to a seasonal variation of discharge typical of the hydro-climatic regime of the mediterranean region. sumhuram, was settled on a rocky coast adjacent to the khor rhori estuary under a climatic setting typical of the subarid tropics variably affected by the monsoon circulation. the pisa-san rossore was a site bearing a potential high hydraulic risk, evidently calculated in respect to the economic advantage given by transferring goods directly from and toward the contemporary pisa downtown. sumhuram was a safe place from geomorphic hazards being also located on a strategic position for the commercial and military control over the gulf of aden. the available chronology for the two sites allows to compare the respective community’s adaptation to the 117 fig. 5 the chronologic range of u1-4 (double arrows) defined in the pisa-san rossore site plotted against the record of the flood frequency of the tiber river at rome (camuffo & enzi, 1995) and historical hydro-climatic data for italy (lamb, 1996). the good correspondence between the catastrophic floods of the arno river and the regional proxy of hydro-climatic events across the roman age, extends the significance of the geoarchaeological record beyond the limits of the site (benvenuti et al., 2006 for details) urban sedimentary archives of pisa and sumhuram approach of commercial ships toward the town. the geoarchaeology of the two sites provides clues from the past for assessing the strategy of resilience and exploitation of the territory behind the potentially negative impact of its physical processes, that can help in building rational and sustainable relations between the present and future human communities and their environment. acknowledgements the authors are grateful to adriana moroni and laura sadori for the review of the paper and to adele bertini for the editorial assistance references aguzzi m., amorosi a., sarti g. (2005) stratigraphic architecture of late quaternary deposits in the lower arno plain (tuscany, italy). geologica romana, 38,1-10. aguzzi m., amorosi a., colalongo mc., et al. (2007) late quaternary climatic evolution of the arno coastal plain (western tuscany, italy) from subsurface data. sedimentary geology, 202, 211-229. avanzini a. (ed) (2008) a port in arabia between rome and the indian ocean (3rd c. bc 5th c. ad). khor rori report 2. arabia antica, 5, pp. 752, l'erma di bretschneider. avanzini a. (ed.) (2011) along the aroma and spice routes. the harbour of sumhuram, its territory and the trade between the mediterranean, arabia and india, mb vision bandecchi & vivaldi, pp.127. avanzini a., sedov av. (2005) the stratigraphy of sumhuram: new evidence. proceedings of the seminar for arabian studies, 35, 11-17. belluomini g., manfra l., tomassi av., vesica p. (2004) l’età dell’antico porto di pisa: datazioni con il radiocarbonio. sci. technol. cultur. heritage, 11, 7-12. benvenuti m., mariotti-lippi m., pallecchi p., sagri m. (2006) late-holocene catastrophic floods in the terminal arno river (pisa, central italy) from the story of a roman riverine harbor. the holocene, 16, 863-876. bruni s. (ed) (2000) the ancient ships of pisa: after a year of work. ed. polistampa, pp. 383. bruni s. (ed) (2002) pisa, la città delle navi. il porto urbano di pisa etrusca e romana dallo scavo al museo: prospettive e problemi. edizioni ets pisa, pp. 58. bruni s. (ed) (2003) il porto urbano di pisa: la fase etrusca il contesto e il relitto ellenistico. silvana editrice, milano, pp.221. buffa v., sedov a.v. (2008) the residential quarter: area a. in: avanzini a (ed.) a port in arabia between rome and the indian ocean (3rd c. bc 5th c. ad). khor rori report 2. roma, l’erma di bretschneider, 15-58. butzer k. w. (1971) environment and archeology: an ecological approach to prehistory. chicago, aldine, pp. 703. camilli a. (2005) il contesto delle navi antiche di pisa. un breve punto della situazione. fastionline, www.fastionline.org/docs/2005-31.pdf camuffo d., enzi s. (1995) the analysis of two bimillenary series: tiber and po river floods. in jones, p.d., bradley, r.s. & jouzel, j. (eds): climatic variations and forcing mechanism of the last 2000 years. springer-verlag, natoansi series, 1, global environmental change, springer, 41, 43350. goiran j.p., morhange c. (2001) geoarcheology of ancient mediterranean harbours: issues and case studies. topoï, 11, 647-669. lamb h.h. (1996) climate, history and the modern world. second edition. routledge, pp.432. mariotti lippi m., bellini c., trinci c., et al. (2007) pollen analysis of the ship site of pisa san rossore, tuscany, italy: the implications for catastrophic hydrological events and climatic change during the late holocene. vegetation history and archaeobotany, 16, 453-465. mariotti lippi m., bellini c., benvenuti m., fedi m. (2011) palaeoenvironmental signals in ancient urban settings: the heavy rainfall record in sumhuram, a pre-islamic archaeological site of dhofar (s oman). the holocene, 21, 951-965. marriner n., morhange c. (2007) geoscience of ancient mediterranean harbours. earth-science reviews, 80, 137-194 martinelli n., pignatelli o. (2008) datazione assoluta di alcuni relitti dal contesto delle navi di pisa. risultati preliminari delle indagini dendrocronologiche e radiometriche col 14c. gradus (online journal, h t t p : / / w w w . c a n t i e r e n a v i p i s a . i t / p u b blicazioni_gradus4.html), 3, 69-78. morhange c., marriner n., carayon n. (2016) the ecohistory of ancient mediterranean harbours. in: bekker-nielsen t. & gertwagen r. (eds): the inland seas towards an ecohistory of the mediterranean and the black sea, franz steiner verlag, 85-106. pranzini e. (2001) updrift river mouth migration on cuspate deltas: two examples from the coast of tuscany italy. geomorphology, 38, 125-32. raffaelli m., mosti s., bellini c., mariotti lippi m. (2011) dhofar the land of frankincense. in: avanzini a. (ed.): along the aroma and spice routes. the harbour of sumhuram, its territory and the trade between the mediterranean, arabia and india, mb vision bandecchi e vivaldi, 17-39 schiettecatte j. (2012) l’arabie du sud et la mer du iiième siècle av. au vième siècle apr. j.-c. topoïsuppl., 11, 237-273. seland e.h. (2014) archaeology of trade in the western indian ocean, 300 bc-ad 700. j. archaeol. res., 22, 367-402. 118 ms. received: april 21, 2018 final text received: august 7, 2018 benvenuti m. et al. microsoft word 00_indice_lm04.docx il quaternario it issn 039-3356 italian journal of quaternary sciences 24 (1), 2011 51-65 the latest continental filling of valle umbra (tiber basin, central italy) dated to one million years ago by magnetostratigraphy 1roberto bizzarri, 2andrea albianelli, 3patrizia argenti, 1angela baldanza, 1roberto colacicchi & 2giovanni napoleone 1dipartimento scienze della terra, università di perugia, perugia 2dipartimento scienze della terra, università di firenze, firenze 3lab. paleontologia dei vertebrati, dip. scienze geologiche, università di roma tre, roma corresponding author: r. bizzarri <roberto.bizzarri@libero.it> abstract: bizzarri r., albianelli a., argenti p., baldanza a., colacicchi r. & napoleone g., the latest continental filling of valle umbra (tiber basin, central italy) dated to one million years ago by magnetostratigraphy. paleogeography of central italy during pliocene and pleistocene is characterized by the on-setting of continental basins, oriented almost parallel to the uplifting apennine mountain chain and marked by the valleys of main rivers arno, chiana, tevere, together with minor intermountain basins (e.g.: colfiorito). the internal range, with its complex of intermountain basins, was bounded by coastal marine deposits of the tyrrhenian and adriatic seas. due to a decidedly established palaeoenvironmental and magnetostatigraphic scenery for valdarno, valtiberina and colfiorito basins, the short section at arquata in the valle umbra basin, here presented, may be constrained much more closely to the evolutionary pattern of the former ones by means of a similar magnetostratigraphic characterization. in particular, detailed magnetostratigraphy led to date the earliest deposits in the valdarno basin at 3.3 ma, whereas in valtiberina the oldest analyzed deposits, which don’t reach the substratum yet, postdate 2.8 ma. upward, the two above mentioned main sedimentary profiles reach 2.0 ma and 2.1 ma, respectively, and in the shorter section of colfiorito only the youngest dates are attained, until 0.78 ma. the same younger date was detected in the valdarno, where also the olduvai chron (1.95-1.77 ma) is recorded, followed by the jaramillo chron (1.05-0.97 ma) after a long sedimentary hiatus. the valle umbra profile exposed near bevagna is dated across the jaramillo chron, the duration of its deposition extending approximately 300 ky. both results are very close to the previously mentioned final fillings of valdarno and colfiorito. riassunto: bizzarri r., albianelli a., argenti p., baldanza a., colacicchi r. & napoleone g., il riempimento continentale più recente della valle umbra (bacino tiberino, italia centrale) datato a un milione di anni fa attraverso la magnetostratigrafia. la valle umbra, nel settore orientale del bacino tiberino in umbria, ha sinora offerto pochi dati per integrare la transizione paleogeografica, da ovest verso est, che ha interessato sia gli adiacenti bacini continentali più ampi (valdarno, val di chiana, valle tiberina), sia i bacini intermontani minori e più orientali (colfiorito), tutti con asse orientato circa nw-se, parallelo alla nascente catena appenninica. nel loro insieme, questi bacini intermontani, appartenenti alla zona centrale della catena appenninica, sono confinati tra fasce costiere peritirreniche e periadriatiche. il quadro paleoambientale e magnetostratigrafico, già individuato per i suddetti bacini, ha permesso ora di fissare anche quello della valle umbra. la successione sedimentaria della porzione sommitale, messa a giorno nella cava arquata a bevagna, permette di integrare il quadro conoscitivo dell’evoluzione paleoambientale più recente dell’italia centrale, poiché conclude quelle fasi del sollevamento appenninico iniziate alla data di 3.3 ma nel valdarno e quelle presumibilmente coeve della valtiberina, interrottesi rispettivamente a 2.0 ma e 2.1 ma. il nuovo ciclo deposizionale è cominciato subito dopo, datato solo nel valdarno, da 1.9 ma a 1.7 ma, mentre il ciclo finale, nel valdarno e a colfiorito, contiene il magnetocrono jaramillo (1.05-0.97 ma). nella successione di colfiorito, inoltre, viene raggiunta la data più recente, testimoniata dalla registrazione dell’inizio dell’ultimo magnetocrono, a 0.78 ma. i depositi studiati in valle umbra sono marcati molto nettamente dalla presenza del crono jaramillo e la deposizione della successione analizzata a bevagna, nei pressi di foligno, ha avuto una durata stimata di 300 ky. la parte finale del pleistocene inferiore e il passaggio pleistocene inferiore pleistocene medio sono calibrati alla data di jaramillo e all’inizio dell’ultimo magnetocrono (brunhes), rispettivamente. entrambi i segnali sono registrati nella sezione di colfiorito. si può ritenere che la deposizione conclusiva fluvio-lacustre della valle umbra sia ragionevolmente coeva con quella dell’altopiano di colfiorito. key words: valle umbra, magnetostratigraphic dating, jaramillo chron, apennine basins, early pleistocene, central italy. parole-chiave: valle umbra, datazione magnetostratigrafica, crono jaramillo, bacini appenninici, pleistocene inferiore, italia centrale. 1. introduction the northern apennine intermountain basins represent bench-marks of structural and stratigraphic significance for updating most of the present environmental studies on continental deposition occurring through the recent geological past. basin infills were firstly assigned pliocene and pleistocene ages according to the lithological subdivision of blue and dark-green clay underlying yellowish sand, with both the lithologies closely equivalent to marine analogous deposits ascribed to the end of pliocene and the beginning of quaternary (e.g., see napoleone et al., 2003; van couvering, 1997). such ages, though, have recently been calibrated to dates by means of magnetostratigraphy, which right in umbria provided the conceptual and more complete r. bizzarri et al. 52 tool for defining the numerical timing for marine sedimentary successions. the present example is aimed at testing a different approach to a short interval of continental deposits, devoid either of direct lithostratigraphic correlation with adjacent sections or of a significant fossiliferous record. actually, biochronologic ages used for classifying mammal fauna stages in the richest nonmarine deposits of italy (azzaroli, 1977; azzaroli et al., 1988) were made equivalent to the biostratigraphic ages once they were both calibrated to the same global scale of geomagnetic polarity reversals, currently used for geochronology (alvarez, 2009). the process was first verified in the nearby upper valdarno, where local lacustrine to deltaic successions had magnetostratigraphically been dated in million years (ma) and several classical villafranchian faunal units, from there established for biochronology, were labelled with an absolute reference (napoleone et al., 2003). the upper valdarno profile contained also the thickest continuous profile and earliest mammal fossil record, so to become the calibration frame for other apennine continental successions, beginning with valtiberina and colfiorito basins in umbria. these intermountain basins, therefore, have assumed the dates in million years of the geomagnetic polarity time scale. in particular, the valdarno sequence was calibrated since 3.3 ma to 1.7 ma, and with a resolution of few thousand years (ky) (albianelli et al., 1997) and even 1 ky (napoleone & azzaroli, 2002). with recently collected data (albianelli et al., 2002; napoleone et al., 2003), and following the calibration of the chronostratigraphic time scale to the geomagnetic polarity time scale (gpts), for the “pliopleistocene boundary and the beginning of the quaternary” it is possible to relate the ages of continental deposits to those of marine sequences, both calibrated to the gauss and matuyama chrons including olduvai. to the olduvai chron the pliocene/pleistocene boundary was fixed at 1.796 ma in the vrica stratotype (van couvering, 1997), albeit, recently, the pliocene/pleistocene boundary has been repositioned at 2.58 ma (gibbard et al., 2010). the magnetostratigraphic analysis of the valle umbra continental sediments has therefore been done for identifying particular intervals (magnetozones) co relatable to the chrons of the geomagnetic time scale, by which the biochronologic “stages” could be calibrated. the magnetostratigraphic survey has been carried out on the profile exposed in the arquata quarry, near bevagna (perugia), in order to attain the continuous dating for the ages expected in the about 65 m thick deposit, from prominent sedimentological and biochronologic evidences selected in the adjacent basins. for that section, sedimentological features, fossil content and magnetostratigraphic calibration are here considered, and firstly some time constrains for valle umbra deposits are proposed, allowing to insert also the eastern branch of tiber basin into a northern apennine basins comprehensive evolutionary scheme. 2. geological setting of valle umbra the paleogeographic evolution of central italy was marked since piacenzian by the setting and development of large continental basins along the inner apennine chain. basin complex was bordered by coastal ma rine deposits on both sides, from the tyrrhenian and adriatic seas, although direct correlations among continental and marine domains are not always clearly documentable. such basins, as the major ones of mugello and upper valdarno, valdichiana and valtiberina, were structurally aligned nw-se, almost parallel to the apennines mountain range, and occur together with the intermountain minor basins, as tavernelle-pietrafitta, gubbio, gualdo, colfiorito, norcia etc. (fig. 1). the structural assessment for all of them lies within tectonic depressions bordered by direct faults belonging to the extensional phase, which followed the compressional one acting since miocene on the whole area of tuscan-umbrian and latium regions. right because linked to the w-to-e migration of the apennine over-thrusting front, ages of the extensional basins and related infill become progressively younger with the same trend (fig. 1). the master-fault system, mainly dipping to sw and associated to the antithetic one, produced half-graben structures with displacements of several hundreds of meters (barchi et al., 1991; menichetti, 1997). pliocene and pleistocene continental deposits cover nearly one third of the umbrian territory (lotti, 1917, 1926) and mainly belong to the tiber basin and its split major valleys, valtiberina (from sansepolcro to terni) and valle umbra (from perugia to spoleto). they are respectively confined by the meso-cenozoic mountain belts of massicci perugini, mt. peglia and narnese-amerina chain, due west, and mt. catria-mt. nerone-mt. serano mountains, due east and separated by the martani mountain range (conti & girotti, 1977; ambrosetti et al., 1977, 1978, 1987, 1989, 1995a; basilici, 1992, 1995; martini & sagri, 1993). the whole basin underwent extensional deformation phases (due to faults reactivation), from gelasiancalabrian to late pleistocene (gregori & cattuto, 1986; barchi et al., 1991; bonini, 1998). contrary to the valtiberina where several exposures are available, valle umbra is fairly poor of outcrops, thus hampering an appropriate recognition of its most recent geologic history (fig. 1.2). in south valle umbra (spoleto area), coltorti & pieruccini (1997) identified two important depositional phases referable to pliocene and pleistocene, respectively, separated by a “tectono-sedimentary discontinuity”. the earlier deposits, unconformably laying on the pre-pliocene substratum, are made of fluvial-lacustrine and alluvial fan-delta sediments. the older are exposed in the spoleto area, in the lignite-bearing levels outcropping at morgnano. the mammal fauna there recovered was classified to belong to the triversa faunal unit, and assigned to the earliest stage of the early villafranchian mammal age in the biochronologic classification of azzaroli (1977). in the valdarno basin a comparable fauna was dated 3.1 ma in the kaena magnetochron (albianelli et al., 1997). most of these lower deposits from valle umbra are made of clays, containing lignite dark levels interbedded with thin sandy levels; in the upper part they mainly alternate with banks of coarser sand and finegrained conglomerates. the younger sedimentary phase, on the contrary, is represented by thick alluvial-fan conglomerates deposited in the southern valley by a number of streams draining the western flank of the seranobrunette ridge and the eastern flank of the martani mts. (coltorti & pieruccini, 1997). the latest continental filling of valle umbra (tiber basin, central italy) … 53 fig. 1 1) sketch of northern apennine extensional basins and geographic collocation of the study area (modified after napoleone et al., 2003). 2) schematic geological setting of valle umbra. 1) schema dei bacini estensionali dell’appennino settentrionale e ubicazione geografica dell’area studiata (da napoleone et al., 2003, modificato). 2) assetto geologico schematico della valle umbra. tectonics played an important role in modeling the present morphology of valle umbra since middle-late pleistocene, even until last interglacial stage (gregori & cattuto, 1986). two major fault systems were acting: one, in the eastern side uplifting the serano-brunette ridge along the border fault, while its piedmont accumulated in fan deposits; the other one, the antithetic eastdipping fault system was uplifting the conglomerates of the second sedimentary phase (presumably), originally laying at the plain level, up to the present montefalco hill, nearly 180 meters above the valley. immediately before this phase of uplift, small ponds were isolated, with local carbonate-siliceous deposition (colacicchi et al., 2007). 3. the arquata quarry stratigraphic section the whole available succession of the valle umbra sediments, representative of latest evolution of the basin, is here exposed across a nearly 65 m thick stratigraphic profile (figs. 2, 3). the examined deposits are mainly formed by clays and sands containing lignite levels, which dip to the sw by 10°-12°. a well visible extensional fault in the mid-profile, almost e-w striking and dipping southward, suggests a minor displacement of few metres (fig. 3). some minor surfaces may be locally recognized, either produced by tectonics or sin-depositional collapses, each less than 1 m in displacement. 3.1 sedimentological features the succession may be referred to a depositional lacustrine and fluvial-lacustrine frame, and two depositional environments are documented: a shallow-water lake and an alluvial plain with distal fluvial supplies (fig. 3). the facies associations are divided accordingly (colacicchi & bizzarri, 2005; colacicchi et al., 2007), as: facies association a (shallow lake environment) the association groups facies referable to a shallow water lacustrine environment. facies a1 is mainly represented by massive to thin-laminated, fossils bearing clay beds (fig. 4.1). thin fine sand lenses showing wave and current ripples locally occur. fossils are both scattered or grouped in thin (up to 5 cm thick) layers, and banks of vegetal matter also occur as thin lignite levels, but more commonly enhancing the lamination. facies a2 is represented by alternations of thin laminated clay and ripple laminated silt/fine sand, with the latter prevailing (figs. 4.2, 4.3). both facies a1 and a2 are referable to a shallow lake environment with stable and presumably faint wave motion. facies a3 is characterized by wave ripple laminated sand (fig. 4.4), locally with hardened top and bottoms and polygonal drying cracks (figs. 4.5, 4.6), documenting subaerial exposure such as of lake beach. wave ripple laminated sands locally contain clay chips, vegetal matter and root remains. facies a4 is represented by duneto ripple-laminated sand resulting from minor turbidites (fig. 4.7), due to distal fluvial flooding and/or sediments remobilization possibly after seismic shocks or strong wind action. some of these sandy bodies evolve to a clearer beach deposits, also showing drying polygons and root remains, as a proof of sedimentation in a not deep environment. facies association b (alluvial plain environment) facies b1 is prevalently composed of laminated silty clay, deposited in an alluvial-plain environment, whereas facies b2 is described as root-bearing massive to laminated clay and is interpreted as poorly drained paleor. bizzarri et al. 54 fig. 2 panoramic views of arquata quarry, along sw-ne (up) and w-e (down) profiles. panoramiche di cava arquata: vista sw-ne (in alto), vista w-e (in basso). soils (fig. 4.10). facies b3 shows decimeter-to-meter thick levels of massive to slightly laminated silty sand (figs. 4.8, 4.9), locally associated with facies b4, the latter described as current ripple and/or cross laminated sand (figs. 4.11, 4.12). the both latter two facies are interpreted as produced by distal fluvial influxes (river flooding). facies association c (palustrine or marsh-pond environment) facies c1 (fig. 4.13) is formed by less than 1 meter-thick lignite levels, usually bearing larger gastropods and unio sp. grey clayey palustrine paleosoils with rooted radical apparatuses, scattered vegetal material, fossils, remains of the original lamination and reddish surfaces are associated in facies c2, which can be indicated as root-bearing massive clay (fig. 4.13). the lignite levels and the massive clayey paleosoils (facies c1 and c2 respectively) are anyhow constantly associated, leading to a poorly oxygenated and strongly reducing environment, able to maintain organic matter almost un-altered. both associations represent swampy lake flanks as well as small ponds and marsh within the alluvial plain. facies architecture the lower two thirds of the succession (unit 1: fig. 3) are dominated by associations a of more frankly lacustrine environment, while alluvial plain deposits (associations b) prevail in the final portion (unit 2: fig. 3). the variable thicknesses of lignite and clays of palustrine deposition (associations c) may be present in both environments, often transitional from a to b (fig. 3). rhythmicity is a recurring characteristics in the a associations, both within a single association and vertically shifting from to one another. long-lasting and stable lacustrine conditions, still with minor variations due to seasonality, supply variations, etc., characterize the lower section, with the predominance of a1 and a2 facies (fig. 3) whereas the shift from lacustrine to alluvial plain conditions may be most probably linked to longer period of climatic fluctuation. post-depositional structures, such as convolute lamination (fig. 4.14) and micro-faulting (fig. 4.15) commonly occur throughout the entire section and are documented in all the described facies. particularly, structures due to subaqueous remobilization of partially lithified deposits (fig. 4.16) suggest a probable seismic origin which testifies of tectonic pulses coeval to sedimentation. 3.2 paleontological record macropalaeontological content is represented by rare vertebrate remains (fragments of carapace and long bones of turtle emys orbicularis and only one scapula fragment of amphibian) and abundant non-marine molluscs, associated to palaeocarpological remains. the malacological assemblage (colacicchi et al., 2005; caprai, 2010) collected in the lower portion (unit 1) is characterized by melanopsis (melanopsis) affinis, theodoxus (neritina) groyanus, viviparus (viviparus) belluccii, prososthenia cf. p. oblonga, neumayria priscillae, emmericia umbra, melanoides (melanoides) curvicosta, unio pillai, dreissena polymorpha, pisidium sp., hauffenia minuta, valvata interposita, v. piscinalis (fig. 5). the assemblages are almost comparable with the ones reported by petronio et al. (2000-2002). occurrence of terrestrial gastropods, as carychium (saraphia) tridentatum and vertigo (vertilla) angustior, although previously reported (simonetti, 1996) have not been here documented. assemblages contain only few species which occur from middle villafranchian (m. affi fig. 3 magnetostratigraphic and sedimentological section in the arquata quarry deposits. in addition to the calibration to gpts scale, recognized facies, fossil content and paleoenvironmental restoration are also provided. sezione magnetostratigrafica e sedimentologica nei depositi di cava arquata. oltre alla calibrazione con la scala gpts, sono riportati anche le facies riconosciute, il contenuto paleonotologico e l’interpretazione paleoambientale. the latest continental filling of valle umbra (tiber basin, central italy) … 55 r. bizzarri et al. 56 fig. 4 sedimentary facies in the arquata quarry deposits. 1) massive and thin laminated clay (facies a1). 2, 3) alternations of thin laminated clay and wave ripple-laminated sand/silt (facies a2). 4) wave ripple-laminated sand (facies a3). 5) particular of hardened top of wave ripples in the facies a3. 6) polygonal drying cracks in facies a3. 7) duneto ripple-laminated sand resulting from minor turbidites (facies a4). 8, 9) massive to slightly laminated silty sand (facies b3); picture 8 also shows channeled base surface. 10) laminated silty clay (facies b1) associated to root-bearing massive to laminated clay (facies b2). 11) top hardened surface of current ripple (facies b4). the latest continental filling of valle umbra (tiber basin, central italy) … 57 12) cross laminated sand, bearing clay chips (facies b4). 13) lignite level (facies c1), at the top of root-bearing massive to poorly laminate grey clay (palustrine paleosoils, facies c2). 14) convolute lamination in clay and silt of facies a2. 15) micro-fractures showing less than 5 cm of dislocation (“micro-faulting”) probably effect of sediment adjustments. 16) sin-sedimentary remobilization of partially lithified clay and silt, due to seismic shocks. facies sedimentarie descritte nei depositi di cava arquata. 1) alternanza di argille massive e sottilmente laminate (facies a1). 2, 3) alternanze di argille sottilmente laminate e sabbie o silt con ripple da onda (facies a2). 4) sabbie con ripple da onda (facies a3). 5) particolare della superficie indurita dei ripple da onda nella facies a3. 6) poligoni di disseccamento nella facies a3. 7) sabbie laminate, con dune nella parte inferiore passanti verso l’alto a ripple da onda, prodotte da correnti di torbida (facies a4). 8, 9) sabbie siltose, da massive a sottilmente laminate (facies b3); l’immagine 8 mostra anche la superficie erosiva canalizzata alla base del deposito. 10) argille siltose laminate (facies b1) associate ad argille da massive a laminate, contenenti resti di apparati radicali (facies b2). 11) superficie sommitale indurita nei ripple da corrente della facies b4. 12) sabbie a laminazione incrociata, con plasti di argilla (facies b4). 13) livello di lignite (facies c1), al tetto di argille grigie, massive o debolmente laminate, con apparati radicali (paleosuoli di palude, facies c2). 14) lamine convolute nelle argille e silt della facies a2. 15) microfratture con dislocazione inferiore a 5 cm (“micro-faulting”), probabilmente risultanti dall’assestamento del sedimento. 16) rielaborazione sinsedimentaria di argille e silt parzialmente litificati, dovuta a shock sismici (micro-sismite). fig. 5 fossil record in the arquata quarry deposits. 1) unio pillai. 2) pisidium sp. 3) dreissena polymorpha. 4) melanoides (melanoides) curvicosta. 5) viviparus (viviparus) belluccii. 6) valvata interposita. 7) melanopsis (melanopsis) affinis. 8) emmericia umbra. 9) prososthenia oblonga. 10) theodoxus (neritina) groyanus. 11) cyprideis torosa. 12) ilyocypris bradyi. 13) potamogeton sp. 14) itea europaea. 15) scirpus isolepioides. 16) ranunculus pseudoflammula (achene) 17) mallotus maii (seed). 18) rubus sp. 19) selaginella gr. pliocenica (macrospore). 20) thalictrum minimum. record paleontologico nei depositi di cava arquata. 1) unio pillai. 2) pisidium sp. 3) dreissena polymorpha. 4) melanoides (melanoides) curvicosta. 5) viviparus (viviparus) belluccii. 6) valvata interposita. 7) melanopsis (melanopsis) affinis. 8) emmericia umbra. 9) prososthenia oblonga. 10) theodoxus (neritina) groyanus. 11) cyprideis torosa. 12) ilyocypris bradyi. 13) potamogeton sp. 14) itea europaea. 15) scirpus isolepioides. 16) ranunculus pseudoflammula (achene). 17) mallotus maii (seme). 18) rubus sp. 19) selaginella gr. pliocenica (macrospora). 20) thalictrum minimum. r. bizzarri et al. 58 nis, t. groyanus, e. umbra and, dubitatively, u. pillai) or olivola f.u. (p. oblonga) to farneta f.u.; n. priscillae is reported only in the tasso f.u., whereas v. belluccii, m. curvicosta and v. interposita are still currently documented in the tasso and farneta faunal units (gliozzi et al., 1997). furthermore, the genera prososthenia and neumayria are considered extinct at the end of early pleistocene, as well as e. umbra and m. affinis, which do not survive beyond early pleistocene (ambrosetti et al., 1995b; gliozzi et al., 1997; petronio et al., 20002002; girotti et al., 2003). mollusc assemblages coming from the upper section (unit 2) only contain d. polymorpha, lacking stratigraphic relevance. the palaeocarpological analyses evidence two different types of assemblages referable to particular edaphic conditions: 1) hygrophilous plants scirpus isolepioides, ranunculus pseudoflammula, cf. itea europaea, living and accumulated in situ, and 2) mesophilous plants potamogeton sp., rubus sp., melissa elegans, ficus potentilloides, mallotus maii, thalictrum minimum of warmtemperate climate, living in the surrounding area and carried by rivers into the basin (fig. 5). these specimens are accompanied by common characee oogonia and other remains. among the latter, a much altered bract and a selaginella gr. pliocenica macrospore (fig. 5.19), a present-day species of humid and shady environment, tropical to sub-tropical (cavallo & martinetto, 2001), are included. microfossils are only represented by freshwater ostracods cyprideis torosa and ilyocypris bradyi (figs. 5.11, 5.12), known in central italy basins from early pleistocene (tasso f.u.) onward (ambrosetti et al., 1987, 1995b; gliozzi et al., 1997). both forms are very abundant in the taphocenosys, and probably well represent the biocenosys: absence of competition and food richness probably supported a well developed community. both species prefer clay or silty-clay bottoms and tolerates anomalous salinity, probably finding here ideal conditions to develop, also due to dissolved salts coming from surrounding exposed rocks. abundance of cyprideis torosa, together with dark-grey colour of deposits, is indicative of low oxygen level at the basin floor, with partial re-oxygenation due to wind and/or rain, which may have remixed the thin water column. biochronology malacological assemblages and the occurrence of cyprideis torosa suggest, for the lower section, a late villafranchian age not older than tasso f.u. some taxa, such as v. belluccii, m. curvicosta and v. interposita, indeed, have been considered as typical of tasso-farneta f.u. interval and never documented afterward (gliozzi et al., 1997). on the other hand, the upper section is characterized by rare fluvial and/or lacustrine specimens, mainly represented by d. polymorpha, occurring on the whole late villafranchian record from tasso f.u. onward, lacking biochronological meaning. 3.3 paleoenvironmental reconstruction facies analysis allows hypothesizing an alluvial plain environment, with contemporaneous occurrence of shallow lakes, with both palustrine margins and beaches, ponds, swamps and creeks, the latter draining from the nearby mountain flanks toward the basin (colacicchi & bizzarri, 2005; colacicchi et al., 2005; colacicchi et al., 2007). such an interpretation is congruent, indeed, with paleocarpologic data, which indicate riverine transport from surrounding areas. facies associations can be compared to the ones described in the western branch of tiber basin in the upper portion of fosso bianco and s.m. di ciciliano units (ambrosetti et al., 1995a, 1995b; basilici, 1997, 2000). particularly, the depositional context seems the same as in the partially coeval s.m. di ciciliano unit, except for the organized river channel deposits totally missing in the arquata section. a longlasting alluvial plain environment, probably endoreic and devoid of an organized drainage, can be proposed for the early pleistocene of valle umbra. some inferences on sedimentation rates can be proposed here. in fact, in the adjacent basins, sedimentation rates vary from 20-24 m/100 ky on lacustrine deposits, both in the tiber basin and in the valdarno, to 35 m/100 ky on fluvial sands in valdarno (napoleone et al., 2003). as the two thirds of arquata section are represented by lacustrine deposits, intermediate values of sedimentation rates between lacustrine and river deposits could be expected. most of the malacofauna has been collected into vegetal remains-rich beds, whereas the ostracods characterize only the purely lacustrine facies. as documented in similar contexts (e.g. fosso bianco lacustrine clay), absence of vertebrates, and particularly of micromammifers, seems mainly due to taphonomy and lack of preservation rather than to paleoecology. 4. the magnetostratigraphic profile 4.1 paleomagnetic sampling the succession of sediments across the lithostratigraphic profile appears quite regular, as remarked above, with noticeable repetitions of sedimentary structures as well as of facies. sampling for magnetic measurements has been carried out at an average spacing of one meter (fig. 3), preferably in the less sandy levels in order to avoid sediment formed under active motion where particle orientation would have been dispersed under a uniform inducing field. the choice helped to better enhance the paleomagnetic vector in sharpening its resolution power for definition of magnetozone boundaries, even in material very weakly magnetized. each sample was extracted from levels excavated across the few meter thick steps used in quarrying operations across the above mentioned profile, and their resulting location was thence accurately fixed in stratigraphic order and of fresh rock material. as remanent magnetizations were presumably weak and no metal protections around, in a nearly 0° declination field, samples were oriented by magnetic compass using manual simple operations. the average spacing of collected levels was chosen at one meter distance, as that used in the other intermountain basins previously investigated so far, considering a presumably recorded time span of some hundreds of ky, and having in accordance the accumulation rate of 30-40 m/ 100 ky been assumed. a second aim, indeed, led collecting unoriented samples at 15-20 cm distances to be measured for their magnetic content under the present field, the magnetic susceptibility, which depends on the amount of magnetic particles under magnetic induction from the present earth’s field. changes in susceptibility were measured in umbria and central italy for either continental or oceanic the latest continental filling of valle umbra (tiber basin, central italy) … 59 fig. 6 alternate-field (af, left) and thermal (th, right) demagnetization procedures applied to the same sample of reversed polarity (aq27), showing a straightforward magnetization path. the zijderveld polar diagram in the middle line shows the initial overprint of the present-day normal field, cleaned after the first demagnetization steps and releasing the primary remanence into the reversed characteristic vector. procedure di smagnetizzazione applicate allo stesso campione, a magnetopolarità inversa (arq 27): campo alternato (af, a sinistra) e termica (th, a destra). entrambe le procedure evidenziano l’esistenza dello stesso chiaro andamento della magnetizzazione. il diagramma polare di zijderveld, nella linea centrale, mostra l’iniziale sovrimpressione del campo magnetico attuale, che viene rimosso dopo i primi gradini di smagnetizzazione, e restituisce la magnetizzazione residua caratteristica del vettore inverso. rock types outcropping, and correlated with climate changes driven by changes in solar radiation due to the orbital forcing, as accounted by the milankovitch theory. the effects of all such parameters were tested (in eccentricity, obliquity and precession modes) either in the former sediments from valdarno and valtiberina (napoleone et al. 2004) or in the latter ones (napoleone & ripepe, 1989). in the present work such results are not reported. a sampling interruption occurred in the arquata profile at about its middle portion, where a marked fault is visible, and above which the vegetation cover did not allow sampling for nearly 10 m. the fault had been interpreted as relevant at the local scale, possibly cutting a slice of the sequence in the order of some meters. also the top profile was not sampled because covered by reworked material from the quarrying activities, as well as its bottom fully occupied by a pond (fig. 3). 4.2 laboratory measurements paleomagnetic measurements were carried out on cubic or prismatic specimens of nearly one-inch side cut from the oriented hand samples. all samples yielded more than two specimens, so that remanence of each level was measured using demagnetization procedures of both types (fig. 6), thermal and by alternative fields (af). the latter using the new built-in degausser of the eth magnetic laboratory at zurich where all the lacustrine sediments from central italy studied in last two decades had been measured. the laboratory procedures were the same as summarized for the upper valdarno basin, which represents the magnetostratigraphic reference for rock types of the analogous continental basins bordering the apennine mountain range (napoleone et al., 2003). stepwise thermal demagnetization was carried out on samples, of each level bed, at closely spaced temperature intervals, in order to detect even minor changes occurring in those weakly magnetized sediments that would have affected the original direction of the primary vector (fig. 6). a complete study on rock magnetism is beyond the aims of the paper; nevertheless, some consideration can be pointed out. no particular changes were noticed for the presence of sulphide minerals, which on the contrary did affect some significant intervals in the lignite-bearing levels of the valdarno with unstable magnetizations. in the final deposits of valle umbra, the paleoenvironmental conditions produced minor oxidation on their magnetic mineralogy. such a behaviour was mainly enhanced by the smooth trend of the af curves (fig. 6), which otherwise assumed in several other occasions for the apennine continental deposits completely inconsistent directions at any successive demagnetization step. this was particularly evident in the valdarno basin beds closer to the thick lignite-bearing level, due to the anoxic conditions there acting during deposition and presence of sulphides still pervading the overlying sediment for more than 50 m in thickness. therefore, the straightforward direction shown by both demagnetization treatments of the paleomagnetic vector to the characteristic primary magnetization is interpreted as the typical behaviour due to the presence of a single component in the magnetic signature; in fact, the characteristic remanent magnetization (chrm) was well isolated already at temperatures above 100-200 °c or at applied fields above 0.2-0.3 mt (fig. 6). on our skill, and according to former results on analogous deposits (albianelli et al., 2003; napoleone et al., 2003), analyses are reasonably consistent with the original paleomagnetic field and enhance magnetozones with different polarity. 4.3 results the total of 55 analyzed levels yielded three intervals of polarity directions, two reversed (r1 and r2) bracketing a normally magnetized zone (n1), within which the polarity change occurs in an evident continuity of the lithostratigraphic profile (fig. 3). the three magnetozones have to be correlated to the chrons of the gpts in order to become calibrated to their dates in million years. that is, they will represent the absolute dating at each limit of a polarity change and a steady time flow throughout the profile, having the gpts been the time expression, in continuous sequence, of the ocean floor magnetic anomaly stripes recorded for a steadily expanding oceanic r. bizzarri et al. 60 crust. at arquata is applied the same criterion as in valtiberina, where for the gauss and reunion chrons, through matuyama, the time resolution was obtained for the total time span 2.8-to-2.0 ma (pontini et al., 2002). here, it has to be taken into account that the olduvai chron lies in the valdarno closely above reunion (200 ky) and in a split mode as in the marine series in marche (central italy) and in calabria (southern italy) (nakagawa et al., 1997; albianelli et al., 2003). after it and until present, only two normal polarity intervals are contained in the gpts, and of them the only normal chron followed by one of reversed polarity is jaramillo. the dates bounding it last 1.05 to 0.97 ma, and it has therefore to be correlated to the n1 magnetozone, whereas for both magnetozones of reversed polarity, r1 and r2, time values ascending and descending outward maintain open limits (fig. 3). thickness and characters of the n1 magnetozone, together with sedimentological consideration about sedimentation rate pertinent to depositional context recognized, agree to its attribution to the jaramillo chron (bizzarri et al., 2009; colacicchi et al., 2009). 5. discussion 5.1 magnetochronology in northern apennine basins the role of magnetic stratigraphy is meant at providing a numerical date (or absolute dating) throughout a continuous succession of sediments whenever its magnetic signature enables to identify intervals of defined magnetic polarity (magnetozones) that can be related to magnetochrons of the geomagnetic polarity time scale (gpts). it seems therefore a quite viable digression here to re-appraise the meaning of the results achieved in the magnetostratigraphic surveys carried out over sedimentary sequences in the intramountain basins close to valle umbra and dated in great detail (ambrosetti et al., 1995a, 1995b; ficcarelli et al., 1997; albianelli et al., 1997, 2002, 2003; coltorti et al., 1998; napoleone & azzaroli, 2002; napoleone et al., 2003). basins surrounding valle umbra provide therefore the primary source to inferring an age for the pile of a presumably much thicker succession, according to the thicknesses visible or estimated in several such basins (fig. 7). but, unfortunately, the geologic and sedimentary history of valle umbra represents the less known portion of the continental deposition in the tiber basin. its south-western branch, in fact, is best known, as the oldest sediments, although not the lowermost ones, released a date of 2.8 ma (albianelli et al., 2002), whereas the north-eastern sector yields most deposits belonging to the final filling. the basal deposition may be inferred, thence, to have begun largely after miocene, considering that in the valdarno basin the exposed contact of the lacustrine facies on the prepliocene substratum was dated 3.3 ma by magnetostratigraphy, as early as in the mammoth chron (albianelli et al., 1997). the latest filling of valdarno, indeed, contains the last magnetochrons centered at nearly 1 ma, but a sedimentation gap lasting at least 0.7 million years (my) has been detected just before it. the mentioned lack of exposures in valle umbra does not enable to further hypothesize about earlier ages of its deposits. the closest comparison of its final filling may be done with the equivalent one in the nearby colfiorito basin (fig. 7), where the outcrops of the uppermost deposits, exposed in the small towns of colfiorito and cesi, released dates respectively ranging from the well confined jaramillo chron (1.05-0.97 ma) to the initial brunhes chron (across the limit of 0.78 ma) (ficcarelli et al., 1997; coltorti et al., 1998). it is worth recalling that the final early pleistocene and the beginning of middle pleistocene are respectively calibrated to these chrons. in the arquata profile, the less than 80 m exposure reduced by a slight dipping to about 65 stratigraphic meters represents a thin cover, whereas the oldest deposits visible in the morgnano lignite mine (spoleto in valle umbra) seem to equate the valdarno lignite-bearing levels mined at santa barbara and dated 3.1 ma (fig. 7). being the arquata quarry profile the final filling phase, the affinity with the adjacent basins leads to infer that a long-lasting slice of time is unexposed and it might relate to the whole late gauss-to-reunion interval (3.05-2.15 ma), part of which was calibrated at toppetti quarry in valtiberina, and in the valdarno through the matuyama chron including olduvai (1.95-1.77 ma). as valdarno and colfiorito basin covers reach a jaramillo and brunhes dating, such values seem perfectly fitting the magnetostratigraphy results in valle umbra. 5.2 geochronological and stratigraphic implications the magnetochronologic result, of the jaramillo date (figs. 3, 7), represents the basic point supporting all stratigraphical considerations to be referred to. firstly, once this 55 m sampled upper profile would be considered as deposited with constant sedimentation rate, the direct correlation between thickness and number of years of accumulation leads to assign 80 ky duration to the 14 m thick intermediate normal polarity level (fig. 3). from this assumption it descends a duration of roughly 60 ky for the upper 11 m of reversed polarity and nearly 170 ky for the lower one 32 m thick, which includes the nearly 7 m unsampled section (fig. 3). the overall duration would be nearly 300 ky, which leads to an accumulation rate close to 20 m/100 ky, excluding compaction rate, fairly low when compared to similar lithologies analyzed in valtiberina and valdarno basins. in these latter, in fact, the massive clay and/or of deeper lake deposition yielded a value of 24 m/100 ky, progressively reaching in the overlying levels, richer in silty sand, more that of 35 m/100 ky. more generally, the sedimentation rates calculated for the two basins (napoleone et al., 2004) range from a minimum of 20 m/100 ky to a maximum of 35 m/100 ky, with averages of about 22 m/100 ky (valtiberina) and 30 m/100 ky (valdarno). although the unknown variable of compaction rate, these values represent an agreeable datum point for the study section. in the lower levels of the arquata quarry, sediments range from silty clay to silt and sand in the lacustrine facies, and are not as finely clayey as in fosso bianco unit. on the other hand the alluvial plain sediments are lithologically analogous to the uppermost valdarno deposits. with such a rate, the overall thickness of the arquata profile would have been sensibly thicker, from 77 to 105 m, in contrast to the measured 65 m, which means that the inferred missing meters need an explanation. some hypotheses can be provided. 1) it may be a consequence of compaction rates, which may reasonably differ from a basin to another, due the latest continental filling of valle umbra (tiber basin, central italy) … 61 fig. 7 magnetostratigraphic dating of arquata quarry section and the valle umbra sedimentary sequences positioned within the apennine basins’ evolution (redrawn and modified after napoleone et al., 2003). calibration of local mammal faunas (lmf) and of main faunal units (f.u.) to gpts is also shown. datazione magnetostratigrafica della sezione di cava arquata, ed inserimento delle sequenze sedimentarie della valle umbra nel quadro evolutivo dei bacini appenninici (da napoleone et al., 2003, ridisegnato e modificato). è riportata anche la calibrazione delle faune locali a mammiferi (lmf) e delle principali unità faunistiche (f.u.) con la scala gpts. r. bizzarri et al. 62 to local variations concerning petrology, grain size and organic matter amount (einsele, 1992; van asselen et al., 2009, with refs.). 2) contrary to valdarno basin, which on-sets on a more erodible sandstone substratum (macigno s.l. auct.), tiber basin, particularly valle umbra, largely set up on a limestone substratum, and sandstones (marnoso-arenacea s.l. auct.) only locally crop out. thus, a primary difference in sediments supply must been considered too. 3) in the case of arquata, the above reported geostructural observations stressed the occurrence of the well visible fault cutting the profile, of minor interruptions due to the inclination (10°-12° sw) of the strata respect the steps of the quarry, as well as of fractures with a not significant dislocation in the upper profile. the latter have been sampled in detail on both sides for a better control. the sampled 55 m can be thence less than those actually deposited: although the disturbances seem at a direct view of minor size, two effects implicitly add to one another. on the one hand, the interval of normal polarity should be slightly thicker, leading to a larger accumulation rate and therefore closer to those measured in valdarno and valtiberina; on the other hand, duration in the adjacent intervals of reversed polarity is shortened and a certain amount of its thickness removed by this main fault, to become reduced significantly. it therefore appears quite likely an accumulation rate of 25-30 m/100 ky, which can become even higher in the final steps of filling more alluvial and palustrineas documented in the valdarno basin (napoleone et al., 2004). in the latter occasion, the control was made by the cyclostratigraphic distribution of the magnetic signature through a 0.5 my long sequence, enhancing at least five steps of increasing sedimentation rates. the consequence would be, for the present profile, a reduction of the erased pile of sediments to less than 25 m, which is significantly shorter than earlier implied but still much more than it appears to a direct view. 4) if we consider the lack of about 5 to 15 m of the succession as exclusively due to the fault occurring between lower and upper sections, an average sedimentation rate of about 25-30 m/100 ky is still appropriate. to support the hypothesis, one more consideration may help, changing accumulation rates in the range from 24 m to 30 m/100 ky, with extremes reaching as much as 19 m to 35 m/ 100 ky: the datum is consistent with paleoenvironmental reconstruction, as the jaramillo record occurs on both lacustrine clay and alluvial plain silty clay/ sand, that would remark a large shift in accumulation rates. at last, an average 25 m/100 ky sedimentation rate, as well as values comprised between 19 m/100 ky and 30 m/100 ky, are perfectly comparable to these of other basins (valdarno, valtiberina). it seems plausible to assume for the top reversed interval of 11 m a date shortly younger than the upper limit of jaramillo at 0.970 ma, e.g., in the range of 0.940-0.920 ma; for the lower reversed magnetozone a rate of 30 m/100 ky yields to a date ranging 1.050 ma (on top) to one not older than 1.130-1.140 ma (fig. 3). also assuming a lower average sedimentation rate (25 m/100 ky), the section bottom cannot be in any case considered older than 1.2 ma. these time constrains, as well as the occurrence of jaramillo, allow attributing the arquata section to the end of early pleistocene, to which the villafranchian-galerian boundary has been also calibrated (fig. 7). mollusc and ostracod assemblages agree with a late villafranchian age, perfectly consistent with the attribution of the long reversal interval (r1 and r2 magnetozones) to the matuyama chron. furthermore, the fossil assemblages in the lower section, which have been collected inside the r1 reversal interval, more than 10 m from the base of n1 interval, are considered as not older than tasso f.u. moreover, taxa such as v. belluccii, m. curvicosta and v. interposita, as well as the occurrence of c. torosa, restrain the time interval to the tasso and farneta faunal units (gliozzi et al., 1997). both tasso and the successive late villafranchian f.u. (farneta, pirro) are calibrated to the reversal magnetopolarity interval successive to olduvai, whereas to the latter are linked the transitional olivola-tasso faunas of matassino and poggio rosso (napoleone et al., 2003). the biochronological record, indeed, is still consistent with the date of nearly 1.140 ma at the base and 0.940-0.920 ma at the top, although clearly galerian faunas have not been documented. 5.3 cyclicities in the magnetic signal as produced by climate changes in valdarno and valtiberina a short recalling is needed for the reported results from valtiberina sediments also for their pollen content in cyclostratigraphic distribution, as well as a direct correlation with that in the valdarno by the continuous dating tied between them. palynological data from the valdarno basin have already shown when in its layer beds the vegetation changes marked the onset of a decidedly oscillating pattern from deciduous forest or still subtropical to an open field herbaceous cover of arid climate origin. dates of such an onset and durations of the steady cyclic patterns were constrained by a high resolution accuracy provided by detailed magnetostratigraphy to have occurred since pliocene throughout the beginning of pleistocene, and they tightly correspond to the ones enhanced by the magnetic signal, across a 1.5 ma record from kaena through olduvai chrons. each limit of the various magnetochrons there present provided tie points to which the cyclic oscillations are tuned, in order to control their rhythms and/or duration in the accumulation hiatuses. therefore, grouping in few classes the continuously varying cyclicities, major changes range from 21 m/100 ky in the lowermost lacustrine clay to 27 m/100 ky, 31 m/100 ky, up to 36 m/100 ky for the maximum influx of sand filling the deposit. when the signal processed in cycle length/meter is tuned to precisely timed tie points, the cycle length in years is expressed in intervals strikingly corresponding to the milankovitch cyclicities. the shorter one among precession, obliquity and short eccentricity, prevails in the lower pile of sediments; at the date of 2.86-2.84 ma a rather sudden increase of amplitude affects the obliquity cycle, while a marked eccentricity is already visible in the short profile of olduvai time beginning just before the gelasian-crotonian boundary. when climate gets prevailingly driven by the short eccentricity cycle at dates close to jaramillo, the shortness of time series in the latest continental filling of valle umbra (tiber basin, central italy) … 63 the arquata profile would barely allow to detect such a cycle, unless it was strongly recorded as it occurred in the olduvai profile for the valdarno. 6. conclusions two major conclusions may be stressed from the present study, both mainly descending from magnetostratigraphic dating. first, the fluvial-lacustrine deposition in valle umbra was over by nearly one million years ago. the inferred presence of sediments equivalent to the montefalco conglomerates (fig. 7), tectonically displaced in the nearby exposures, would imply a short duration for their deposition, which makes still rather long the missing time span until present, i.e. up to the historic and protostoric times. secondly, the time length recorded at arquata would not exceed 300 ky, which leads to roughly imply that only 10-15% of the possibly 3-to-1 ma of the tiber valley infilling is here exposed. from the purely geochronologic point of view one may recall another conclusion, i.e., all recorded proxies benefit a date to which their alleged ages are calibrated; having the direct chronologic reference, adjustments may be done for correlation with other exposed sequences. such is the case of the present biochronologic record, whose assessment in the calibrated frame of the apennine basins may be accomplished: the tasso f.u. established in the valdarno is calibrated to a date lasting 1.6-to-1.7 ma, right after the end of olduvai chron. the malacofauna recovered at arquata, therefore, is dated quite younger than the vertebrate tasso f.u., and confirms that biochronology by itself is a fairly weak tool for timing short intervals. a multidisciplinary approach, also involving magnetostratigraphy, if possible is therefore already preferable. another important result is that the arquata section revealed, in the present study, a number of similarities in its evolutionary trend with other basins of central italy, as well as a clearer assessment of the geological events through the tiber valley. its magnetostratigraphic dating provides a second constrain for valle umbra evolution (fig. 7), after the attribution of morgnano lignite to triversa f.u., dated to 3.3 ma in the valdarno basin. with such time limits, the two main sedimentary cycles here recognized by coltorti & pieruccini (1997) are still confined. the lower cycle can be linked to pliocene, whereas the top of the second one date to the end of early pleistocene (fig. 7). thus, this study in valle umbra adds a decisive element to define, until the date of 1 ma, the evolution of tiber basin in the paleogeographic setting of apennine basins. the intermediate cycle, well documented in the valdarno basin and commonly accepted although not dated also for valtiberina (napoleone et al., 2003), still has not been recognized here, being probably buried below exposed sediments. arquata date across the jaramillo chron helps enhancing how facies associations in the eastern branch may be related to those in the western branch, the valtiberina (fig. 7). here the earliest lacustrine deposition in the fosso bianco unit, dated as old as late gauss chron, constrains the overlying fluvial deposits of s.m. di ciciliano unit to be coeval with those of the valdarno basin final filling, but, while magnetostratigraphic data presently enable timing in detail the deposition of these two units of the tiber basin, it does not occur for the intermediate ones, for which it is desirable a direct time control. the immediate prospect is that several paleogeographic restorations can be quantitatively controlled by timing their evolutionary extent. it is also worth noting that the measured dates for the final filling of valle umbra basin, marked also in the surrounding intermountain basins, are recorded in the marine hemipelagic deposits of the eastern apennines belt of the umbrian-marchean realm, i.e. in the basins of the peri-adriatic platforms (albianelli et al., 2003). continental and marine sediments belonging to the same chrons, are then coeval in deposition. even in the marine conditions, the depositional features followed similar rhythms, with a long continuous phase in the earlier ages of pliocene since mammoth and kaena chrons followed by a shorter interval crossing the olduvai; more displaced are the youngest deposits, but all dates are strikingly corresponding on both sides of the apennine divide (fig. 7). on such prospects it would be important to pay careful attention on timing the intensive tectonics in the uplifting of peninsular italy. acknowledgements authors wish to thanks the property and the workers of the arquata quarry, and especially the responsible of the quarry, sig. pietro antano, for their courtesy and the help in the sampling. this work has also been possible thanks to the project: “invito al parco lungo i percorsi delle sue acque e della sua storia”, conceived and promoted by prof. m.r. trabalza. references albianelli a., azzaroli a., bertini a., ficcarelli g., napoleone g. & torre d. (1997) -paleomagnetic and palinologic investigations in the upper valdarno basin (central italy): calibration of an early villafranchian fauna. riv. it. paleont. strat., 103, pp. 111-118. albianelli a., magi m., mazzini m. & napoleone g. (2002) the plio-pleistocene boundary in the northern apennine continental deposits as defined by the faella magnetostratigraphic section in the upper valdarno. boll. soc. geol. ital., special volume, 1, pp. 473-479. albianelli a., cantalamessa g., didaskalou p., micarelli a., napoleone g. & potetti m. (2003) magneto-stratigraphic dating of the middle and late pliocene sequence in the marchean apennines, central italy. il quaternario, 16 (1), pp. 171183. alvarez w. (2009) the historical record in the scaglia limestone at gubbio: magnetic reversals and the cretaceous-tertiary mass extinction. sedimentology, 56 (1), pp. 137-148. ambrosetti p., basilici g., capasso-barbato l., carboni m.g., di stefano g., esu d., gliozzi e., petronio c., sardella r. & squazzini e. (1995a) il pleistocene inferiore nel ramo sud occidentale del bacino tiberino (umbria): aspetti litostratigrafici e biostratigrafici. il quaternario, 8 (1), pp. 19-36. r. bizzarri et al. 64 ambrosetti p., basilici g., ciangherotti a. d., codipietro g., corona e., esu d., girotti o., lo monaco a., meneghini m., paganelli a. & romagnoli m. (1995b) la foresta fossile di dunarobba (terni, umbria, italia centrale): contesto litostratigrafico, sedimentologico, palinologico, dendrocronologico e paleomalacologico. il quaternario, 8(2), pp. 465-508. ambrosetti p., conti m.a., parisi g., kotsakis t. & u. nicosia (1977) neotettonica e cicli sedimentari plio-pleistocenici nei dintorni di città della pieve (umbria). boll. soc. geol. ital., 96, pp. 605 635. ambrosetti p., carboni m.g., conti m.a., costantini a., esu d., gandin a., girotti o., lazzarotto a., mazzanti r., nicosia u., parisi g. & sandrelli f. (1978) evoluzione paleogeografica e tettonica nei bacini tosco umbro laziali nel pliocene e nel pleistocene inferiore. mem. soc. geol. ital., 19, pp. 573-580. ambrosetti p., carboni m.g., conti m.a., esu d., girotti o., la monica g.b., landini b. & parisi g. (1987) il pliocene ed il pleistocene inferiore del bacino del fiume tevere nell’umbria meridionale. geogr. fis. dinam. quat., 10, pp. 10-33. ambrosetti p., cattuto c. & gregori l. (1989) geomorfologia e neotettonica nel bacino di tavernelle/pietrafitta (umbria). il quaternario, 2, pp. 57-64. azzaroli a. (1977) the villafranchian stage in italy and plio-pleistocene boundary. giorn. geol., 41, pp. 61-79. azzaroli a., de giuli c., ficcarelli g. & torre d. (1988) late pliocene to early pleistocene mammals in eurasia: faunal succession and dispersal events. palaeogeogr. palaeoclimatol. palaeoecol., 66, pp. 77-100. barchi m., brozzetti f. & lavecchia g. (1991) analisi strutturale e geometrica dei bacini della media valle del tevere e della valle umbra. boll. soc. geol. it., 110, pp. 65-76. basilici g. (1992) il bacino continentale tiberino (pliopleistocene, umbria): analisi sedimentologica e stratigrafica. tesi di dottorato, università degli studi di bologna, 323 p. basilici g. (1995) sedimentologia della parte distale di un conoide alluvionale del pliocene superiore (bacino tiberino, umbria). il quaternario, 8, pp. 37-52. basilici g. (1997) sedimentary facies in an extensional and deep lacustrine depositional system: the pliocene tiberino basin, central italy. sedim. geol., 109, pp. 73-94. basilici g. (2000) pliocene lacustrine deposits of the tiberino basin (umbria, central italy). in e. h. gierlowski kordesch, and k. r. kelts, eds., lake basins through space and time, aapg studies in geology, 46, p. 505-514. bizzarri r., albianelli a., argenti p., baldanza a., colacicchi r. & napoleone g. (2009) primi dati magnetostratigrafici dalla valle umbra: la sezione di cava arquata (bevagna, umbria). atti del convegno “ricerca, applicazione e comunicazione delle scienze della terra” (preci, 27-28 marzo 2009). bonini m. (1998) chronology of deformation and analogue modelling of the plio-pleistocene “tiber basin” implications for the evolution of the northern apennines (italy). tectonophysics, 285, pp. 147-165. caprai v. (2010) il pleistocene continentale in valle umbra (umbria orientale): malacofaune ed ostracofaune dalla cava arquata variazioni paleoecologiche e paleoclimatiche. tesi di laurea, università di perugia, 132 p. cavallo p. & martinetto e. (2001) flore carpologiche del pliocene di castelletto cervo (biella). boll. mus. reg. sci. nat. torino, 18 (2), pp. 277-343. colacicchi r. & bizzarri r. (2005) late pliocene early pleistocene lacustrine facies assotiations in the arquata quarry (valle umbra, central italy). geoitalia epitome, 1, p. 224. colacicchi r., argenti p., baldanza a., bizzarri r. & pauselli o. (2005) geological, lithostratigraphical and paleontological analysis of plio-pleistocene deposits of the arquata quarry (bevagna, perugia, central italy). geoitalia epitome, 1, p. 77. colacicchi r., bizzarri r., argenti p., baldanza a. & pauselli o. (2007) studio geologico multidisciplinare della cava dell’arquata. in: trabalza m.r. & colacicchi r. (eds.) invito al parco lungo i percorsi delle sue acque e della sua storia. dell’arquata ed., foligno, 293 pp. colacicchi r., bizzarri r., napoleone g., albianelli a., argenti p. & baldanza a. (2009) magnetostratigraphic update of valle umbra continental deposits from the bevagna section (perugia, central italy). geoitalia epitome, 3, p. 397. coltorti m. & pieruccini p. (1997) the southeastern tiber basin (spoleto, central italy): geology and stratigraphy of plio-pleistocene sediments. il quaternario, 10, pp. 159-180. coltorti m., albianelli a., bertini a., ficcarelli g., napoleone g. & torre d. (1998) the colle curti mammal site in the colfiorito area (umbrianmarchean apennines): stratigraphy and palynological analysis. quat. intern., 47, pp. 107-116. conti m.a. & girotti o. (1977) il villafranchiano nel “lago tiberino”, ramo sud-occidentale; schema stratigrafico e tettonico. geol. rom., 16, pp. 67-80. einsele g. (1992) sedimentary basins. evolution, facies, and sediment budget. springer-verlag, berlin, 628 p. ficcarelli g., abbazzi l., albianelli a., bertini a., coltorti m., magnatti m., masini f., mazza p, mezzabotta c., napoleone g., rook l., rustioni m. & torre d. (1997) cesi, an early middle pleistocene site in the colfiorito basin (umbrianmarchean apennines), central italy. j. quat. sc., 12, pp. 507-518. gibbard p. l., head m. j., walker, m. j. c. & the subcommission on quaternary stratigraphy (2010) formal ratification of the quaternary system/period and the pleistocene series/epoch with a base at 2.58 ma. j. quaternary sci., 25, pp. 96-102. girotti o., capasso barbato l., esu d., gliozzi e., kotsakis t., martinetto e., petronio c., sardella r. & squazzini e. (2003) the section of torre picchio (terni, umbria, central italy): a villafranchian site rich in vertebrates, molluscs, ostracods and plants. riv. it. paleont. strat., 109 (1), pp. 77-99. gliozzi e., abbazzi l., argenti p., azzaroli a., caloi l., capasso-barbato l., di stefano g., ficcarelli g., kotsakis t., masini f., mazza p., mezthe latest continental filling of valle umbra (tiber basin, central italy) … 65 zabotta c., palombo m.r., petronio c., rook l., sala b., sardella r., torre d. & zanalda e. (1997) biochronology of selected mammals, molluscs and ostracods from the middle pliocene to the late pleistocene in italy. the state of the art. riv. it. paleont. strat., 103, pp. 368-388. gregori l. & cattuto c. (1986) elementi geomorfologici ed episodi di tettonica recente nei dintorni di spoleto (umbria). boll. soc. geol. ital., 105, pp. 173-184. lotti b. (1917) l’antico lago tiberino e le ligniti dell’umbria. miniera ital., 1, pp. 274-275. lotti b. (1926) descrizione geologica dell’umbria. mem descr. carta geol. d’it., 21. martini i. p. & sagri m. (1993) tectono-sedimentary characteristics of late miocene quaternary extensional basins of the north appennines, italy. earth sc. rev., 34, pp. 197-223. menichetti m. (1997) analisi geologico-strutturale dell’area di pietrafitta-tavernelle (umbria occidentale, italia centrale). il quaternario, 10, pp. 3-14. nakagawa h., niitsuma n., takayama t., matoba y., oda m., tokunaga s., kitazato h., sakai t. & koizumi i. (1997) the magnetostratigraphy of the vrica section, italy, and its correlation with the plio-pleistocene of the boso peninsula, japan. in: van couvering (ed.), the plio-pleistocene boundary and the beginning of the quaternary. world and regional geology series, 9, xi-xvii. cambridge university press, pp. 46-56. napoleone g. & azzaroli a. (2002) a collection of fossil vertebrates from the upper valdarno (central italy) calibrated in the end pliocene to span 220,000 years across the olduvai magnetochron. riv. it. paleont. strat., 108, pp. 479-492. napoleone g. & ripepe m. (1989) cyclic geomagnetic changes in mid-cretaceous rhytmites, italy. terra nova, 1 (5), pp. 437-442. napoleone g., albianelli a., azzaroli a., bertini a., magi m. & mazzini m. (2003) calibration of the upper valdarno basin to the plio-pleistocene for correlating the apennine continental sequences. il quaternario, 16 (1bis), pp. 131-166. napoleone g., albianelli a. & fischer a.g. (2004) magnetic susceptibility cycles in upper pliocene lacustrine deposits of the northern apennines, italy. in: cyclostratigraphy: approaches and case histories. sepm special publication, 81, pp. 263-274. petronio c., argenti p., caloi l., esu d., girotti o. & sardella r. (2000-2002) updating villafranchian molluscs and mammal faunas of umbria and latium (central italy). geol. rom., 16, pp. 369-387. pontini m.r., albianelli a., basilici g., bertini a. & napoleone g. (2002) palynology and magnetostratigraphy of the middle late pliocene lacustrine sequence in the tiberino basin (central italy). boll. soc. geol. it., vol. spec. 1 (2), pp. 467-472. simonetti i. (1996) analisi paleontologica dei molluschi continentali del pleistocene inferiore della cava di bevagna (perugia). tesi di laurea, università di roma “la sapienza”, 54 p. van asselen s., stouthamer e. & van aschet th.w.j. (2009) effects of peat compaction on delta evolution: a review on processes, responses, measuring and modeling. earth-science reviews, 92, pp. 35-51. van couvering j.a. (1997) preface. in: van couvering (ed.), the plio-pleistocene boundary and the beginning of the quaternary. world and regional geology series, 9, xi-xvii. cambridge university press. ms. ricevuto il 12/05/2010 testo definitivo ricevuto il 5/09/2010 ms. received: may 12, 2010 final text received: september 5, 2010 amq106 margaritora et al pc7 jpg.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 33 (1), 2020, 115-132 the lower and middle palaeolithic settlements in the baldo-lessini mountains. results from a gis investigation. davide margaritora1, alessandro dozio1, giorgio chelidonio1, maria chiara turrini1, marco peresani1, 2 1 università di ferrara, dipartimento di studi umanistici, sezione di scienze preistoriche e antropologiche, ferrara, italy. 2 istituto di geologia ambientale e geoingegneria, consiglio nazionale delle ricerche, milano, italy. corresponding author: marco peresani <marco.peresani@unife.it> abstract: on the monti lessini and the monte baldo, two mountain areas of the veneto pre-alps, studies grounded on human ecology, landscape use and site catchment analysis are still sparse or standing at a preliminary state. a factor of bias is the limitation of the archaeological record that was subject to many paleoenvironment processes, compromising its conservation, with substantial loss of information in the open-air sites. in order to shed light on the lower and middle palaeolithic settlements in these sectors we apply gis analysis of location features, as a support provided by the methodological innovation in archaeological research. the analysis is significant for the comprehension of territoriality and also provides tools available for the protection of archaeological and cultural heritage in these areas. site location preferences are the result of a complex decision-making process. using a methodology based on territorial and employment parameters, already successfully applied in other contributions, the results obtained are key issues in the understanding of subsistence strategies, territorial occupation and settlement patterns during the lower and middle palaeolithic. keywords: palaeolithic, settlement, landscape, gis, venetian prealps. � 1. introduction since the end of the 19th century, the monti lessini and the monte baldo, two mountain areas in the central southern pre-alps, are successfully surveyed for investigations on the lower and middle palaeolithic sites, supported by excavations and multidisciplinary projects. especially in the monti lessini, where the number of mousterian sites counts the highest in veneto, a great bulk of data was produced from deposits in caves, rock shelters and in open air sites; remarkable when compared to other mountain ranges in italy. therefore, the study of the settlement system is possible despite the increasing dearth of information as the evidence dates back in time to the oldest record of palaeolithic archaeology. aside the encouraging support provided by the methodological innovation in archaeological research, studies grounded on human ecology, landscape use and site catchment analysis are still sparse or standing at a preliminary state. a factor of bias is the limitation of the archaeological record to mountain or hilly sectors that were lapped only by alpine glaciers and non intensively or only partially affected by periglacial processes, or those fluvial terraces spared by destructive post-depositional processes. as the preservation degree varies, not all the finds share the same informative potentiality. as a consequence, many aspects of the settlement system inferred from site exploitation territory, site function and raw material circulation can only be studied on a limited range of evidence, the more detailed of which are provided by the stratified archives. the layout of these contexts allows exploring human behavior in relation to the environmental context. on the other hand, the open-air sites were strongly affected by post-depositional processes which caused the impoverishment of traces of past human activity with substantial loss of information. anyway, their location features are equally significant for territoriality and site catchment analyses under the focus of the following work. 2. brief presentation of the monti lessini and the monte baldo the monti lessini, also called "lessinia", is a prealpine mountain group located north of the town of verona belonging to the veneto pre-alps. morphologically identified as carbonate plateau, it bounds with val d’adige valley to the west and with valle di leogra valley to the east (fig. 1). the group is limited by the carega massif, which reaches up to 2260 meters of altitude, and by “valle dei ronchi” valley to the north, whereas on the south it gently dips towards the alluvial plain of the adige river and other tributary rivers. the plateau reaches 1860 meters of elevation and slightly bends southwards; it can be considered a monocline structure with a trapezoidal shape, where the shortest side is the northern one. it is radially dissected by several valleys developed along the tectonic lines of the whole area; some sections take the form of a canyon, locally termed vai. the top surface of the plateau could be interpreted as a late tertiary erosional surface, dissected by tectonic activity and eroded in correspondence of the nne fault systems https://doi.org/10.26382/amq.2020.13 116 margaritora d. et al. (zampieri, 2000). generally, the plateau top and the summits of the ridges were mainly affected by weathering, karst and slope processes which led to the development of terra rossa type paleosols (castiglioni et al., 1990). as for monte baldo, it is an alpine group in the sub -section of the gardesane pre-alps, in the section of the bresciane and gardesane pre-alps (marazzi, 2005). it bounds with the garda lake to the west, with the adige valley to the east, with the loppio valley to the north and to the south with garda gulf, caprino depression and the moraine amphitheater of rivoli veronese. it mainly consists in a mountain range, reaching up to 2219 meters, that develops in the north-east/south west direction, and in a series of ridges, small plateaux and terraces in the southern, eastern and northern sides. the group rises asymmetrically: the western side slope varies from 40% to 80% at the top, while the eastern side consists in plateaux and depressions hanging on the steep right slope of the adige valley. geologically, the mountain area is constituted by a stratigraphic succession of carbonate rocks formed in a marine environment, with high presence of chert outcrops (bosellini et al., 1967; carraro et al., 1969). depending on their composition, position and permeability, the various formations exert an influence on the hydrography hydrography the structural and lithological control on the hydrography is strong which is divided into a dense network of main valleys, to which other smaller valleys connect from the ridges (pasa, 1954). these result both by the mechanical erosion and by the chemical erosion caused by water along fault lines and tectonic fractures. both the mountain and hill areas have few superficial water flows, are mainly inactive or only temporarily active -, while they are sculptured by a dense karst hydrographic network. the springs are closely linked to rainfall and the flow rate is not constant over time. most of them are not perennial. the effects of karst processes are not only visible from the hydrographic network, but also from a series of different superficial and underground morphologies, developed because of the numerous faults and fractures that accelerate and facilitate the path of water through the rocks (sauro, 1973; mietto & sauro, 2000). therefore, these morphologies are expression of fluvialand tecto-karstic styles: that is well evident from the superficial forms, from the sinkholes, mostly present along fracture lines or along stratigraphic joints, especially between the maiolica and the underlying jurassic limestone. during the quaternary the area was partly covered by the adige glacier or by the local glaciers attested on the upper part of the monti lessini, the carega massif, the summit of the monte baldo chain (sauro, 1973; sauro & zampieri, 1999). periglacial conditions activated strong erosion of the paleosols, accumulations of slope deposits, especially in the central part of the plateau, loess sedimentation spread all over the relief from the middle pleistocene onward (magaldi & sauro, 1982; castiglioni et al., 1990). deposits in caves and rock shelters along the slopes provide data for estimate that the deepening of gorges and valleys occurred at least from the late middle pleistocene (castiglioni et al., 1990; cremaschi, 1990). anthropogenic erosion during the holocene strongly affected the main slopes especially starting from the neolithic. the lessini valleys are occupied by mainly gravelly, sandy and pelitic floods several meters thick, in addition to the frequent detrital deposits at the foot of the steepest slopes consisting of limestone and dolomitic formations. the lessini and baldo foreland include a large alluvial plain that mostly originated during the middle and late pleistocene from the main river, the adige and its tributaries from the central and eastern monti lessini (de zanche et al., 1977; ferraro, 2009). particularly the western sector, is an area situated where the adige spreads from its long and deeply incised valley which dissects the mountain range up to the alpine watershed. 3. historical context the lessinia region can be undoubtedly considered one of the most prominent areas for the development of prehistoric archaeology in italy (aspes, 1984; 2003; aspes et al., 2002). some first paleontological observations already began in the first half of the 18th century: for example, in 1739 the priest gregorio piccoli described the discovery of faunal bones in a cave locally called “la taneséla” in proximity of alfaedo (piccoli del faggiol, 1739; curi, 2001). consistent with biblical thinking, which permeated most of the researchers of the time, he interpreted those fossilized remains as "diluvial wild beasts" (sauro, 2017). few years later (fortis, 1786), several fossilized bones of elephas meridionalis cromeriensis (and other coeval large mammals, such as rhinos sp.) (bon et al., 1991), where discovered at serbaro di romagnano and, similarly, classified as “antidiluvian”. the first scientific approach to paleontological discoveries in the lessini mountains was published by the museum of natural history of vienna: the naturalist abramo massalongo, observed that carts full of pleistocene vertebrate bones (mainly of ursus spelaeus), extracted from the clayey layers of the karstic cave complex covoli di velo, were brought downstream and sold as fertilizers (massalongo, 1851). associated to lithic artefacts, these findings were brought to the attention of the academy of agriculture, arts and commerce of verona, the royal venetian institute of sciences, literature and arts and the “notiziario degli scavi” by, for the most part, stefano de stefani. however, the rate of discoveries of new pleistocene sites increased mostly in the first half of the 20th century, thanks to the untiring activity of raffaello battaglia, along with an intense scientific production (battaglia,1957; latella & sauro, 2007). his perseverance in publishing the results of his research had positive repercussions in the verona area, as did the reports from giorgio dal piaz and the excavations and recoveries at the quinzano quarries (cave di quinzano) executed from 1933 to the late ‘50s by battaglia himself, paolo graziosi and piero leonardi (see aspes, 1984, for a complete bibliography). during the second world war and especially in its aftermath the researches were consolidated under the coordination of angelo pasa, francesco zorzi and p. leonardi, leading the natural history museum of verona to become a fulcrum for the activities in the fields of pal 117 aeontology and paleoethnology, even beyond the confines of the lessinia region (zorzi & pasa, 1944-45; zorzi, 1959). the above-mentioned quinzano excavations were followed by findings of new artefacts from the surface, excavations in the ponte di veja caves, the discovery of grotta del mondo cave and the interventions at riparo mezzena rock shelter by f. zorzi, a. pasa and maria vittoria durante pasa and those at riparo zampieri by arturo palma di cesnola. the untimely demise of a. pasa in 1966 coincided with a quiescence of the scientific activity in the verona area, compensated by the institute of geology of the ferrara university with the start of decades-long excavations at riparo tagliente rock shelter and of new researches in the ponte di veja caves (broglio et al., 1963; bartolomei & broglio, 1975). this period of intense investigations was fundamental for the studies on the prehistory of the verona area in the following years (leonardi & broglio, 1962). extended surface researches were led also by the centro studi e ricerche (center for studies and researches), headed by giovanni solinas between 1950 and 1965, with numerous reports of sites and sporadic findings in the lessinia localities of ceredo, lughezzano, cà verde and more. the activity of the natural history museum since the ‘70s and its dense network of collaborators (g. chelidonio, f. spadoni, l. farello, a. castagna and others) lead to the detection of one of the highest densities of palaeolithic sites known on the alpine arc, not only on the monti lessini, but also on the monte baldo (pasotti, 1970; chelidonio, 1980; chelidonio & rosà, 2011; chelidonio et al., 2015). the traces distribute through a wide altitude range, between 80 and 1600 meters (battaglia, 1957; zorzi, 1959; leonardi & broglio, 1962; peretto, 1980; chelidonio, 2017; dalmeri & duches, 2008), reaching the valley bottoms and the karst surfaces on the plateau. cavities are much better represented, with grotta di fumane cave, riparo mezzena and riparo tagliente (for a complete bibliography on this last site until the beginning of the ‘80s see bartolomei et al., 1982). open air sites were reported in the higher vajo di squaranto and on the sub-structural terraces at lower altitudes on the ridges between the mezzane and illasi valleys. along with the activities on the field, the superintendence for archaeological heritage of veneto sustained with constancy projects of collaboration with local amateurs and projects for the revision of palaeolithic industries, often finalized to the fruition of this rich archaeologic corpus in the museums of the territory. fig. 1 map of monte baldo and lessini mountains showing the location of palaeolithic sites analyzed. technical notes: coordinate system: monte mario/italy zone 2 (fuso e) datum: roma 40 projection: gauss-boaga fuso: est epsg: 3004; digital elevation model (base topography veneto region dtm 5 m, http://www.regione.veneto.it/web/ambiente-e-territorio/geoportale), garda lake (http:// www.sinanet.isprambiente.it/it/sia-ispra/download-mais/). the lower and middle palaeolithic settlements in the baldo-lessini mountains. results from a gis investigation 4. archaeological context the hefty collection of sites and finds ascribable to the lower and middle palaeolithic or to a generic ancient palaeolithic on the monti lessini and the monte baldo is associated with variable context conditions (fig. 1). the lower palaeolithic finds are numerous but of extremely uncertain chronological positioning, due to the erosion and the deep post-depositional weathering to which these archaeological contexts have been subjected. their attribution was therefore assumed essentially on the tecno-typological characteristics of the lithic artefacts, or by the degree of patination of their surfaces. the oldest lithic assemblages are composed of mostly thick flakes, sometimes retouched and in association with some bifaces. assemblages from the quinzano quarries, monte gazzo and cà palui are more recent, characterized by the association of levallois artefacts and bifaces. the quinzano quarries remain still the most important site, also because of the association with faunal remains of deer, elephant, fallow deer and roe deer (zorzi & pasa 1944-45), and a human occipital. this important pedo-sedimentological sequence was firstly described and interpreted by zorzi & pasa (1944-45) and pasa (1956) and, few decades after, considered by m. cremaschi as a record of potential reference for the geomorphological evolution of the landscape at the foot of the lessini. the lower and middle palaeolithic levels are embedded in the lowermost macro-unit (unit 1, cremaschi, 1984), an alternance of palaeosols and slope waste deposits, separated by erosional surfaces with stone-lines. unit 1 is sealed by the fluvial sediments of unit 2. the richest sources of information are the contexts preserved in the atrial cavities and under rock shelters, along stratigraphic deposits at times complex and articulated. these are key archives with information about chronology, evolution of natural environments and various expressions of human behavior that have manifested during the last glacial cycle. among the deposits systematically explored, we mention riparo zampieri, riparo mezzena, the “cave a” of veja, riparo tagliente, grotta della ghiacciaia and grotta di fumane. currently the data of greater detail come from the excavations in progress at grotta di fumane and riparo tagliente, whose deposits provide useful elements for developing studies on food subsistence, the organization of living spaces, the exploitation of land resources and human mobility in the territorial belt of the lessini and the upper po plain. grotta di fumane, in addition, is a key site for the middle palaeolithic transition with the upper palaeolithic, with the oldest cultural attestations ascribable to the anatomically modern humans. grotta di fumane preserves a 12m thick sedimen 118 tary sequence composed of four macro-units, s, br, a and d covering a chronological range extended from mis 5 to mis 2 (bartolomei et al., 1992; martini et al., 2001) with a cultural record ascribed to the mousterian, uluzzian, aurignacian and gravettian cultures. assessments based on sedimentological, pedological and palaeontological analyses have been previously reported by cassoli & tagliacozzo (1994), cremaschi et al. (2005) and lópez-garcía et al. (2015). current investigations are focusing on the late mousterian levels with their dense scatters of lithic and faunal remains as in units a11, a10, a9 and a6 (peresani, 2012; peresani et al., 2011a; 2011b; 2017). mousterian industries at riparo tagliente are associated with amounts of faunal remains recovered all across the stratigraphy and especially in extensively explored uppermost levels (bartolomei et al., 1982; arzarello & peretto, 2005). grotta della ghiacciaia preserves a short sedimentary series composed of three macro-units that record environmental evolution in the first part of the late pleistocene with evidence of human presence in the two upper macro-units (bertola et al., 1999). riparo zampieri and “grotta a” di veia were settled approximately during the late pleistocene, despite dating programs are still lacking. a different issue concerns riparo mezzena. the mousterian assemblages recovered in this small shelter dates to the late middle palaeolithic (bartolomei et al., 1980), although serious uncertainties affect the consistency of the sedimentary sequence and particularly the chronological position of the presumed neanderthal remains (condemi et al., 2013), now directly dated to the late neolithic (talamo et al., 2016). sites poorer in archaeological data have been identified in open air at various points of the lessini, mainly in the central-western sector, where vitreous flint and chert deposits abound. the same conditions are also found in the last open-air sites discovered on the lessini at the highest altitudes (1400-1600 meters), in the high vajo di squaranto, and on sub-structural surfaces and terraces at lower altitudes along the ridges between the valleys of mezzane and d’illasi. similarly, the monte baldo chain has also returned some of these evidences, represented by levallois lithic industries on the surface, with extremely poor information on chronology, environmental context and significance of human presence. most of the sites located in the basiana valley vary between 1050 and 1068 meters a.s.l., an elevation range which was neither unreached by the erosional activity of the local glaciers nor covered by the lateral moraines of the adige glacier. basiana valley, along with tasso valley, are part of a group of plateaux connected to the monte baldo syncline (chelidonio, 2004). finally, in 2017 the vajo salsone site was discov----------->>>> tab. 1 archaeological sites (multilayered sites as singles cases) and their geographic area (geog), altitude (h a.s.l.), geological substrate (geol), context of find (cont), drainage basin (dr basin), topography position, slope value, slope range (sl range), cultural assessment (cult) and reference. note for geological substrate: eocene limestones (eoc l), oolitic limestones (ool l), maiolica (m), quaternary deposits (qu dep), scaglia rossa (sr), basalt (bas), rosso ammonitico veronese (ra), grigi limestones (grey l) and ialoclastite (ialo); for context of find: surface (surf), depression (dep), karst grike (kg), dolina (do), plowed field (pf), stratigraphic layer (layer); for position: alpine pass (ap), top of the ridge (top), medium slope (med sl), bottom valley (bot); for cultural assessment: mousterian (mou), archaic mousterian (arch mou), acheulean (acheu). margaritora d. et al. 119 the lower and middle palaeolithic settlements in the baldo-lessini mountains. results from a gis investigation ered on the right slope of the middle valpantena. it is represented by huge amount of levallois lithic artefacts and faunal bones contained in a karst pit developed in oolitic limestones and opened during a road cutting (peresani et al., 2018). being the entire archaeological record in secondary deposits and still undated, this makes the location of the original site uncertain. 5. materials and methods the territorial and spatial analysis of human occupation during lower and middle palaeolithic in monte baldo and monti lessini required a geo-localization of sites (caves, rock shelters and open-air sites). their cultural attribution was based on lithic industry: the acheulean was defined by the presence of bifacially flaked handaxes; the archaic mousterian by levallois or discoid technologically-based industries associated to bifaces; the mousterian by levallois and/or discoid industries, despite the presence or absence of retouched tools. 5.1. archaeological data set the analyses were carried out separately for the two distinct geographic areas: identifying 62 sites for the lessini mountains, for a total of 130 frequentations. of these, 73 frequentations, for a total of 55 sites, are open -air sites. in monte baldo area only 18 sites have been identified, none of which is multi-layered (tab. 1). for both areas, analyses were carried out on all sites, all sites count the multi-layered context a single case, all open-air sites and the open-air sites considering the multi-stratified sites a single case. the analyses were carried out separately for the two distinct geographic areas: identifying 62 sites for the lessini mountains, for a total of 130 frequentations. of these, 73 frequentations, for a total of 55 sites, are open -air sites. in monte baldo area only 18 sites have been identified, none of which is multi-layered. based on literature, 11 categories of discovery areas were established: "plowed field" "quarry"; "depressions", a landform sunken or mountain seasonal or permanent pools of unknown origin; "dolina"; "caves", excavated deposits in caves and rock shelters; "layer”, a stratified deposit exposed during construction works; "karst grike"; "surface", collecting during survey; "bottom valley"; "slope". in several cases, evidence was not enough clear to assign findings to any of these categories. 5.2. methodology in order to record the exact position of each site mention by literature two weeks survey were conducted. 38 sites were located using "garmin 60" gps model. when the precise finding area was no longer detectable coordinates were extracted by referring to the nearest 120 place name. in other cases, recent buildings and forest made the sites inaccessible. thus, it was necessary to use the "capture coordinates" function of qgis for recording their position and place them on the regional technical map of the veneto region, 1:10.000 raster format. then a database based on several attributes was developed. some of them were extrapolated by direct observation during the surveys, whereas others were inferred from terrain parameters generated by the original dtm, which was provided by the geoportal of veneto and trentino alto adige regions (1:10.000, cell size 5m series). attributes are listed below: i absolute altitude: the altitude of the site above modern sea level. for the examined area, the difference between modern and pleistocene sea levels is irrelevant, since all the sites are located far inland and are not subjected to pericoastal factors. furthermore, the potential magnitude of the still active tectonic dislocations cannot be overlooked in the interpretation of the absolute altitude. given the alpine uplifting, that could be estimated to be of one meter every 1000 years (sternai et al., 2019), the primary elevation of a 100 ky old site could differ by at least 100 meters from the present-day. however, given the isostatic rebound the alpine chain underwent since the last deglaciation, every attempt to reconstruct the exact dislocation resulting from the combination of tectonic, geomorphic and isostatic processes (mey et al., 2016) remains problematic. ii drainage basin: any area where precipitation collects and drains off into a common outlet. drainage basins converge into other ones at lower elevations in a hierarchical pattern, with smaller sub-drainage basins, which in turn drain into another common outlet. iii topography: the position of every site related to the valley floor. sites positioned at less than 10 m from the valley floor were included in the category "valley floor". sites positioned within 10 m from the top of a mountain ridge are rated to the "summit" category. "pass" has been assigned to sites located near relevant mountain passes. iv slope: the magnitude of steepness or the degree of inclination of a feature relative to the horizontal plane expressed in percentage. v aspect: the cardinal direction to which the cave mouth/rock shelter and open-air site faces. vi geological substrate: the nature of loose sediment or bedrock. vii insolation: the estimation in hours of the sunlightmean time received annually by each site. viii viewshed: the extension of landscape observable from each site, and the dominant direction of visibility, see paragraph 5.2.4. 5.2.1. hypsometry terrain characteristics are important factors for determining settlement location and habitability of an area. hypsometry specifically deals with categories of elevation that comprise catchments, or drainage basins, and related post-depositional factors in archaeological site assemblages. for each analysed area the dem was recalculated margaritora d. et al. based on altitudinal intervals of 100 m (fig. 2). for each interval both the surface <(km²) and its covered percentage in relation to the entire area was calculated. thank to this it was possible to observe whether the sites location related to specific altitudinal ranges are attributable to cultural choices or, more simply, influenced by the area morphology, in which a certain altitudinal range is dominant. 5.2.2. slope the surface topography influences several factors, such as habitability conditions and mobility and accessibility patterns. regarding open air sites it might be also an indicator of the potential of the conservation. in order to calculate the slope, it was necessary to develop a slope model through the dem. a classification into four categories of terrain slopes for the whole area was performed. the categories are divided into ranges between defined percentages (0-10%, 10-20%, 20-35% and 35100%). the slope value for each site was obtained by a query function. 5.2.3. insolation sunlight and sun heating are generally considered as important factors for a favourable habitability condition, especially during severe environmental conditions. in order to calculate the potential amount of sunlight hours received by each site, the insolation map was prepared using bartorelli's tables (1967), which define the annual sunlight hours based of data derived from, latitude, the angle of exposure of the slopes and the percentage of steepness (bartorelli, 1967). the exposure map was reclassified in order to obtain 72 classes (i.e., values from 1 to 72) corresponding to a 5° range each. a reclassification of the slope map was made, obtaining values from 1 to 4, corresponding to the following slope ranges 0-10%, 10-20%, 20-35%, >35%. subsequently, the parameters were recalculated based on a specific formula (slope values multiplied by 100, added to the exposure values) to obtain the values (from 101 to 472) to be reclassified with the rules of the bartorelli tables. 5.2.4. viewshed visibility is other important factor that might influence the choice of stationing sites and/or places to carry out specific activities. we proceeded by setting the observer's height to 1.75 m and an observation radius of 5 km was applied. the operation was carried out for all 75 sites present. for each site the returned area was divided by circular definition, into sixteen equal parts, each corresponding to an interval of 22.5°. in this way, it was possible to establish which cardinal direction corresponds to the portion of territory visible in relation to the observation point. 6. results the examination of the lower and middle palaeolithic sites based on specific parameters reveals some evidence useful to comprehend criteria that mostly influenced the human occupation in the analysed area. 6.1. monti lessini caves and rock shelters are the prevailing archaeological contexts (57 cases) in the monti lessini area (fig. 3a), whereas finds in plowed fields (16) and dolinas (10) are less represented. other discoveries took place on the soil exposed during construction works (7), in sediments within karst fissures (7) and in depressions (7), although the latter were not exhaustingly described in literature. five archaeological sites have been report 121 fig. 2 a, map of monte baldo area hypsometry based on altitudinal intervals of 100 m; b, map of monti lessini area hypsometry based on altitudinal intervals of 100 m. technical notes: coordinate system: monte mario/italy zone 2 (fuso e) datum: roma 40 projection: gauss-boaga fuso: est epsg: 3004; digital elevation model (base topography veneto region dtm 5 m, http:// www.regione.veneto.it/web/ambiente-e-territorio/geoportale), garda lake (http://www.sinanet.isprambiente.it/it/sia-ispra/download-mais/). the lower and middle palaeolithic settlements in the baldo-lessini mountains. results from a gis investigation ed on slopes. few findings occurred during quarrying activities (3), within streambeds of small tributary valleys (2) or on the soil surface (2). in 14 cases it was not possible to trace the context of discovery. considering the multi-stratified sites as single cases (fig. 3b), caves undergo a sharp downsizing (7) and match the number of dolinas. plough zone contexts are still well represented (12), followed by grikes in limestone bedrocks (5), depressions in the ground (5), findings occurred during construction excavations (5), findings along slopes (4), findings in streambeds (2), surface findings (2) and only one in quarry contexts. no context can be assigned for 12 sites. as regard altitude (fig. 4a), most of sites (112) lie under 800 m a.s.l., especially between 300-399 m (43) and 200-299 m (34), whereas finding between 800 and 1000 m are scarce (6). above 1000 m a.s.l., evidence of frequentations is absent, except for those into the ranges of 1400-1499 m (4) and 1300-1399 m (3). findings below 800 m a.s.l. prevail even counting each multi-stratified context as a single item (fig. 4b). sites between 800 and 1000m decrease to four. beyond 1000 m the 122 number of sites is four, all of them located between 1300 and 1500 m. in total, open-air findings confirm the most set below 800 m with a concentration between 200 and 299 m (12), followed by 500-599 m (11) and 300399 m (11) (fig. 4c). above 1000 m a.s.l. frequentation evidences are rare and never exceeding four sites per altitude range. open-air sites considered as a single element (fig. 4d) did not show significant variations compared to all open-air frequentation. according to the one-sample kolmogorov-svirnov test of the data of the single sites (multi-stratified sites counted as single cases) (fig. 5), this distribution seems to follow a normal distribution, and in consequence the concentration of the site between 200 and 700 m is not statistically significant, not even for the whole sample (z =1,089, p 0,200). regarding drainage basin attribution analysis, where the multi-stratified sites are counted as singles cases, many sites do not produce evidence (42). most of the useful sites are associated with second order basins (9), followed by those related to third order basins (8) and first order basins (3). the relationship between each single site (despite multi-occupational ones) and the geological substrate (fig. 6a) reveals eocene limestones as the most occupied (31), followed by oolitic limestones (11) and maiolica (9 sites). rosso ammonitico veronese (3), basalt (3), quaternary deposits (2), scaglia rossa (2), and hyaloclastite (1) are rare. open-air sites (multi-stratified sites counted as single cases) show a similar trend (fig. 6b). analysing sites according to their topography (fig. 7), a preference for medium slope (67) compared to the summit of the reliefs (39) and valley bottom (24) was detected. this range between medium slope and summit reduces (31 vs 27 respectively) considering multioccupation sites as single cases. sites placed at the fig. 3 archaeology discovery context of monti lessini: 3a, all sites; 3b, the multi-layered sites considered as single cases. fig. 4 graph of the altitude range of monti lessini, with interval of 100 m: 4a, all sites; 4b, the multi-layered sites considered as single cases; 4c, concerning all open-air sites; 4d, the multi-layered open-air sites considered as single cases. margaritora d. et al. bottom of the valley fall to three. open-air findings are mostly located at the summit of the reliefs (39), while sites at the medium slope decrease significantly (32). bottom valley sites are only two. multi-stratified open-air sites counted as single cases are both located on the medium slope and at the summit count 27 cases. only one site is positioned on the valley bottom a peculiar case of relation between elevation, geomorphology, sedimentary basin and tectonic uplifting is the mousterian context of cà verde. deposits are contained in a dolina-like depression developed inside a paleo-channel track with partially preserved related sediments of variable thickness, still preserved for over one km in length (brunetto & chelidonio, 1990). the site is located at 100 m of elevation above the adige pleistocene flooding plain. based on this evidence, carton & castaldini (1985) have argued that the cà verde track long pre-dates the adige gorge at ceraino. data relating to the slope exposures (fig. 8a), show that most sites occurred on places exposed to the south west (37), to west (25) and to south east (20). on the other hand, less than half of the previous ones are located near slopes facing north west (6), north east (5) and south (5). the less frequented slopes are those facing east (3), and north (2). numerous frequentations took place in flat areas with null slope exposure values (20). considering multi-stratified sites counted as single (fig. 8b), show that most sites are located on places exposed to the south east (12). on the other hand, less than half of the previous ones are located near slopes facing south west (6), west (6), south (5) and north west (5). the less frequented slopes are those facing east (3), north east (3) and north (2). numerous frequentations took place in flat places with null slope exposure values (26). for open-air sites (fig. 8c), many sites are exposed to the south east (17). the remaining sites are relatively exposed to the north west (6), west (6), north east (5) and south (5). the less frequented slopes are those facing south west (4), north (3) and east (1). the other sites are in flat places with null slope exposure values (26). open-air sites considered as a single element (fig. 8d) did not show significant variations compared to all open-air frequentation. the slope data refer to the total number of sites, with multi-stratified sites counted as single sites. most of them lie on 0-10% (20) and 10-20% (18) incline, in comparison to 20-35% (12) and above 35% (12). regarding the visibility, most sites show very favourable viewpoints to different directions. at a first glance we notice two groups: the most frequent have a wider range of view over the horizon, with several adjacent sectors; in 10 cases, however, the orientation of the visible is less wide, but opened on two distant cardinal directions, sometimes opposite one another. there are 26 sites with visibility oriented in three or more contiguous directions. the most striking result regards ceredo, whose potential viewpoint covers all the cardinal directions. finally, analyses have not been successful in 11 cases. the estimation of the amount of sunlight hours per year (fig. 9) shows that most of the findspots receive over 1500 hours (122 sites; 94%). only 8 cases (6%) 123 fig. 5 one-sample kolmogorov-svirnov test of the altitude data of the single sites (multi-stratified sites counted as single cases). technical notes: number of sites 62; average value 505,306; standard deviation 308,137; skewness 1,625; kurtosis 2,758; d max absolute 0,138; d max+0,138; d max-1,205, k-s z 1,089; p smaller than 0,200. cumulative distribution function (cdf); obs cdf =observed cdf; exp cdf =expected cdf for a lognormal distribution; z =z score. fig. 6 geological substrate (multi-layered sites considered as singles cases) of monti lessini: 6a, all sites; 6b, only open-air sites. fig. 7 topography positions of the sites in monti lessini, in red the quantity and percentage of all sites; in blue the quantity and percentage of only open-air sites. the lower and middle palaeolithic settlements in the baldo-lessini mountains. results from a gis investigation record lower amounts and only one site (1%) stands below 1000 h/yr. most recurrent values are 2547 (32; 25%) and 1725 (26; 20%) h/yr. the value of 1725 h/yr is assigned by default to sites located on a flat area with a maximum inclination of 10%. the highest peak stands at 2613 h/yr. for multi-occupation contexts, considered as single sites, we observed that only six (6%) cases receive less than 1500 hours per year, while only one (2%) less than 1000. 34 (55%) sites fall in the 1000 2000 sunlight h/yr with concentration around 1725 (20). values above 2000 were assigned to 27 (43%) sites. the open-air sites (multi-stratified sites counted as single cases) show the predominance of those with an amount of sunlight hours above 1500 h/y (49; 89%). the sites that fall in the 1000 2000 values are 32 (58%). values above 2000 were assigned to 22 (40%) sites. according to the one-sample kolmogorov-svirnov test of the data of the single sites (multi-stratified sites 124 counted as single cases) (fig. 10), these are not normally distributed, and consequently the concentration of the sites with 1725 (flat areas) of sunlight hours is statistically significant, referred for the whole sample (z =1,681, p 0,010). 6.2. monte baldo in monte baldo there are no multilayered sites, sites in caves or under shelter. among the archaeological contexts (fig. context baldo), findings on the soil surface prevail (5 cases). other discoveries took place in depressions (3), on slopes (2) and within streambeds of small tributary valleys (2). there are few fids in dolina (1), in sediments within karst fissures (1) and on the soil exposed during construction works (1). in 3 cases it was not possible to trace the context of discovery. considering elevation (fig. 11), we note that all cases (18) lie over 600 m. the number of sites varies from 3 to 1 in the various altitudinal ranges between 600 and 1900 m, except for the range 1200-1300 m and 1700 -1800 m which do not present any findings. beyond 1900 m no human presence was found for the chronological period in question. regarding drainage basin attribution analysis, many sites do not produce evidence (16). all useful sites are associated with second order basins (2). the relation between each single site (despite multioccupational ones) and the geological substrate reveals oolitic limestones as the most frequent (7), followed by quaternary deposits (3), eocene limestones (2), maiolica (2), scaglia rossa (2) and gray limestones (2). rosso ammonitico veronese, basalt and hyaloclastite are absent. analysing the site topography, sites locate mostly on the medium side (9) than at the summit of the reliefs margaritora d. et al. fig. 8 slope exposure data in monti lessini refer to the: 8a, all sites; 8b, all findings, the multi-layered sites considered as singles cases; 8c, all open-air sites; 8d, multi-layered open-air sites considered as single cases. fig. 9 values of the annual sunlight hours in monti lessini: in blue dots the values of multi-occupation contexts considered as single cases; in red dots the values of all open-air sites and the multi-layered sites considered as single cases. fig. 10 one-sample kolmogorov-svirnov test of the annual sunlight hours data of the single sites (multi-stratified sites considered as single cases). technical notes: number of sites 62; average value 1948,806; standard deviation 395,417; skewness -0,261; kurtosis -0,335; d max absolute 0,213; d max+0,2013; d max-0,133; k-s z 1,681; p smaller than 0,010. cumulative distribution function (cdf); obs cdf = observed cdf; exp cdf =expected cdf for a lognormal distribution; z =z score. (4), on passes (4) and valley bottom (1). data relating to the slope exposures, show that most sites occurred on places exposed to the north east (3) and east (3). the less frequented slopes are those facing north (2), west (1), south west (1), south east (1) and north west (1). no frequented sites are south facing. numerous frequentations took place in flat places with null slope exposure values (6). regarding the visibility, most sites show very favourable viewpoints to different directions with a wide range of view. in 3 cases, however, the orientation of the visible is less wide, but turned towards two far apart, sometimes opposite, directions. there are 7 sites with visibility oriented in three or more contiguous directions. finally, analyses have not been successful in 1 case. the estimation of the amount of sunlight hours per year shows that all findspots receive over 1200 hours. only 2 sites (1%) stands above 2000 h/yr. most recurrent values are 1725 (6; 33%) h/yr. the value of 1725 h/ yr is assigned by default to sites located on a flat area with a maximum inclination of 10%. the highest peak stands at 2391 h/yr. 7. discussion the gis data produced in this study reveal the existence of a common trend among all the sites, despite the circumstances of their discovery being not uniform. concerning the monti lessini area, although most of the human frequentations were investigated in primary position in stratified cave contexts, a portion of sites is positioned on morphological settings which are subjected to severe erosion; this reduced the optimal conservation of the archaeological record. however, the frequency of these discoveries marks out the importance of karst geomorphic processes for the conservation of the anthropogenic evidence despite its primary or secondary position in territories intensively subjected to erosive action. the development of this geomorphic process is closely related to the geological substrate and to its aptitude to karst morphogenesis, depending on the presence of faults and on the structural layout of the limestone formation. data show that finds are located within dolinas, depressions in the ground and grikes. most of these structures have developed into oolitic limestones where lithic artefacts, loess-like deposits, palaeosols and reworked sediments are preserved, where otherwise would have disappeared. a representative example is the site of contrada barozze, discovered after a road cutting exposed a karst structure filled of loamy-clayey stratified sediments and palaeosols (cremaschi et al., 1990) with lower, middle and late palaeolithic artefacts (chelidonio & solinas, 1983). most of the findings took place on eocene limestone formations, which leaves room for different interpretations and hypotheses. the greater frequency of discoveries recorded on these limestones can be related to a choice of the human groups targeted towards 125 fig. 11 graph of the altitude range of monte baldo, with interval of 100 m concerning all sites. the lower and middle palaeolithic settlements in the baldo-lessini mountains. results from a gis investigation places where this substrate emerges, alongside with other factors driving land use and distribution of resources. one variable that explains the reason that many sites are located on eocenic limestones is certainly the fact that these formations prevail in the foothills area. elevation could be considered as a driving factor, being the 400 m a.s.l. level largely below the lowermost position of the timber line during the late pleistocene. besides, water springs are distributed on eocene limestone bedrocks, sometimes in proximity of volcanic rocks. however, the intensive agricultural exploitation of the soils that developed on these bedrocks favours the surface findings, since ploughing enhances their visibility. it is therefore conceivable that the greater occurrence of findings on arable contexts and on substrates of eocene limestone in comparison to others is the result of bias rather than of a precise choice of settlement. with respect to the valley floor, the greater number of sites is located at medium elevation along the slope and on the top of the ridges. considering individual spots in valley bottom, their frequency increases, even though as a mere consequence of the multilayering at tagliente, mezzena and ghiacciaia rock shelters. given the sedimentary nature of the valley bottoms, it can be assumed that many frequentations located in valley floor areas, at the lowermost elevation, are now covered by thick alluvial sedimentary sheets and are thus no longer explorable. this is confirmed by the exposition of archaeological layers at quinzano and cà verde after intensive quarrying, and by geological data achieved from pits in the middle and lower valpantena at grezzana and san felice extra. no chronological data are currently available on these sedimentary sheets. in the lowermost clayey layer (from -148 to -129 m) of the “verona est” pit, positioned at 52 m a.s.l., pollen association reveals ecological conditions compatible with mis 5e or 5c (sorbini,1993). in contrast, the high occurrence of places at summits might reveal systematic settling of the landscape along possible routinely paths covered by the huntergatherers for reaching the highest elevations and ecotones. it must be considered, however, that locations on top ridges and medium slopes are more visible as a result of exposure caused by erosive processes, favouring survey and surface discoveries. the distribution of sites in relation to the drainage basin does not reveal specific occupational preference for one area but can be considered as a result biased by differences in survey intensity. our data do not output possible correlations or specific recurring trends for the proximity to a precise hydrographic order, although we cannot neglect that this was an important parameter for settling down in the landscape. relation between slope intervals and finding contexts does not reveal any trends, if we except surface collecting on ploughed fields, depressions and soils, which are the most frequent in the two lowermost intervals (0-10% and 10-20%). we note the recurrence of caves in the > 35% range referring slope where they are located. data relates to rough and steep slopes covered for reaching those favourable, stable positions. the distribution of single spots and multi-layered sites 126 (fumane and tagliente) on slopes reveals a prevalence of sw and w expositions, despite most of the findings are located on flat areas with undeterminable orientation. the lowermost value has been recorded for slopes oriented to the n and, slightly higher, to the s. it can be assumed that the great frequency of sites exposed from ne to se and sw-nw reflects the morphological characteristics of the ridges, aligned to directions converging to the north. therefore, this result should be interpreted as an expression of the hilly landscape morphologies, rather than an evidence of locational preferences. to reinforce this hypothesis, we explored the correlation between slope and solar exposure for all frequencies. although sites facing south get the highest exposure values, most of the frequentations occur between 50° n and 150° n, and between 200° n and 310° n, with lower insolation values in some cases with discrepancies of over 1500 hours. the numerosity of sites exposed to the se (112.5° n 157.5° n) is remarkable: absolute values are high, between 2194 and 2428 sunlight h/y and play in favour of occupational choices driven by both the landform and profitable solar exposure. therefore, insolation can be considered an important parameter in the settling of an area. the computation of the yearly amount of sunlight hours for each single site reveals a major occurrence between 1300 and 2200 hours, with peaks at 1742 and 2451 and that these frequencies correlate to the peculiar characteristic of the landscape. as before, places with insolation over 1500 hours were probably targeted for the implantation of the seasonal camps. moreover, several sites with values >2200 h/y testify the settling of specific areas with favourable characteristics in sun exposure, despite their poor representation among the totality of the investigated area. from the data above, the occupational preference for some areas over others could be conceivable. in all cases, the most represented altitudinal range are 200299 m and 300-399 m a.s.l., however it has be noted that the southern offshoots of the ridges were more surveyed than other morphological traits of the landscape (fig. 12). being placed at medium-low altitudes, ridges fig. 12 graph of percentage curves: in red the percentage of surface of altitude ranges, in relation to the entire area; in black the percentage of the sites located in each altitude range. the columns show the number of the sites contained in the altitude ranges. margaritora d. et al. might have led to over-representing some data. figure 13 shows the correlation between the altitude of sites (multi-layered sites taken as single cases) and the annual sunlight hours and does not in favour of hypothesizing the existence of a specific strategy of settlement and territorial occupation. criteria of settlement does not seem were influenced by the conditions of sun exposure, showing a wide variability at all altitudinal range. we infer that the exploitation of the landscape at high and low altitude does not was driven by significant differences in the sun light parameters for select a specific area. we have seen how low and high altitude sites do not differ in parameters related to sun exposure, likewise the visibility does not significantly vary in function of the elevation. the data show that most of the sites have views that cover several contiguous slices of land towards some of the cardinal directions, while in 10 cases visibility is limited to two distinct directions. when we plotted the sites with a single large visual covering several contiguous cardinal directions, and the respective elevations, we noticed that the variability of width of the visual field does not follow a specific criterion as the elevation increases (fig. 14). the sites below 1000 m range in the number of visibility slices from one to eight cardinal directions, with a variability that does not indicate a specific occupational strategy. for the two sites over 1000 m does not exceed two slices, it emerges that at higher elevations the occupational choice did not consider such parameter as a priority. both of spots set over 1000 meters falls within depressions with severe limitation in the visible slices of territory due to the geomorphological context. besides, a secondary position of the artefacts due to colluviation is conceivable in these sedimentary basins and, therefore, with bias in the divergence between the spots located at low and high altitudes. sites located in valley, like còal del bota in vaggimal and riparo tagliente, have both visible field and directionality oriented in concordance with the valley axis and morphological layout. even for these cases, the visibility parameter does not seem to have been considered in the occupational choice. 8. conclusions the survey and geolocation of the lower and middle palaeolithic sites and findspots on the monti lessini and monte baldo leads to the creation of an applicable database available for studies on settlement dynamics, for archaeological heritage archiving and for the developing of predictive thematic maps, archaeological risk evaluation and archaeological protection. this type of cartography would fill a gap between the tools available for the protection of archaeological and cultural heritage in such an important area for prehistory. using a methodology based on territorial and employment parameters, already successfully applied in various contributions (miller & barton, 2008; garcia, 2012; 2013; garcia et al., 2013), our results and considerations fulfil the proposed objectives. from our output data we notice how in several 127 the lower and middle palaeolithic settlements in the baldo-lessini mountains. results from a gis investigation fig. 13 kendal tau test for the correlation between the altitude of sites (multi-layered sites as single cases) and the annual sunlight hours. wessa, (2017), kendall tau rank correlation (v1.0.13) in free statistics software (v1.2.1), office for research development and education, url https:// www.wessa.net/rwasp_kendall.wasp/. fig. 14 kendal tau test for the correlation between the number of continuative visible directions of sites (multi-layered sites considered as singles cases) to their respective elevations. the graph does not include the sites located by place name and the sites that have returned two opposite portions of visible territory, to maintain compliance of the analysed data. wessa, (2017), kendall tau rank correlation (v1.0.13) in free statistics software (v1.2.1), office for research development and education, url https://www.wessa.net/rwasp_kendall.wasp/. cases the parameters here analysed have been considered in the settlement choice, at least in a certain part of the territory. in many others, however, it seems clear that some recurring values may not be the reflection of the precise search for an area that meets specific requirements. rather, they would be related to the morphological characteristics of that specific part of landscape. in addition, it has been noted that the greater representation of some values does not depend on a choice that takes into consideration well-defined employment parameters, rather it may reflect a research deficit which affected some areas more than others. the attributes related to the context of discovery show that, although most of the frequentations have been found in cave excavations, a great divergence arises from site to site. data inhomogeneity and difference in the location degree of the findings therefore affected the analysis, causing limitations in internal comparisons of our record. attributes inherent to the geological substrates are emblematic of this limit. the great representation of plough contexts on eocene limestone substrates should not be interpreted like an evidence of a precise occupational choice, rather than of a research bias in favour of the ploughed fields, which were ubiquitously present only till the ‘70s of 20th century, often on the southern offshoots of the lessini ridges. the same holds for positions on the top of the reliefs and on medium slope, where surveys were easier on ridges than in forested bottom valleys. being ridges subjected to erosion, possibilities of making surface-type recoveries are enhanced compared to the valley floors, which are urbanized and covered by thick slope waste deposits and alluvial sediments. nevertheless, in few but very meaningful sites such as cà palui, monte gazzo and passo di san valentino, lower and middle palaeolithic artefacts were found in concentrations very likely attributable to knapping activities in proximity of extended outcrops of chert. in the valley floors, the only discoveries occurred following cave research and building excavations, that allowed examining soils and sediments in depth. the same deficit could affect the possibility of proposing recurring trends in the relation of the sites to the river basins, being most of the finding points placed at the top of the reliefs and straddling multiple orders. taking into consideration the data relating to the slope, we can see that the greatest representation of discoveries in the 0-10% and 10-20% ranges is well attested, frequently in ploughed fields, dolinas and depressions in the ground. on the other hand, the presence of five caves on >35% slopes attest the effort of encompassing steeped slopes for reaching stable and favourable niches. the distribution of data on slope exposures does not reveal any occupational preference in relation to a specific cardinal direction, rather it reflects landscape features of the lessini area, with its ridges and slopes exposed from ne to se and sw to nw. the major representation of the sites exposed to se with insolation values between 2194 and 2428 hours per year leaves however the possibility that the choice of the settlements might also be driven by favourable conditions of annual hours of sunshine. our data, for ranges between 128 1300 and 2200 h/y, seem to indicate that camps were positioned basically in function of the landforms. on the contrary, the location criteria for settlements exposed to over 2200 h/y are mostly driven by the preference for areas with matching characteristics of sun exposure. when we plotted sun exposure data with elevation, we did not notice a correlation between the altitude and the search of high number of sunshine hours. from these data it is therefore possible to assume that this parameter did not play a major role in settling within this hilly and mountain landscape, at least in relation to the altitude of the site. the potential visibility related to each site indicates two general ranges. the most frequent are sites with multiple and continuous viewpoints, despite for only one slice of territory. in 13 cases, however, the orientation of the visible is less wide, but faces two markedly different directions, sometimes opposed one another. if we correlate sites with multiple continuous viewpoints to their elevation values, we do not reveal any divergence in land use between sites at low and high elevation. in conclusion, we argue that parameters like geological substrate, position in respect to valley floor and attribution to an order of the river basin are affected by the degree of intensity of research. this was so high in certain areas to generate overrepresentation of the most recurrent values. the great frequency of findings on flat zones does not seem to be affected by this deficit. slope exposure compared to solar exposure allows us arguing a direct dependence of frequentations from the landforms. however, the sites facing se and sites with sunlight values higher than 2200 h/y confirm that sun exposure should be excluded as main criteria adopted to settle that section of landscape. although sparse and fragmentary, current data on the lower and middle palaeolithic settlement system in the hilly and mountain landscape of verona reveal some aspects relatable with the paleogeographic, paleo -economic and cultural contexts of the sites. these could be an expression of the seasonal nomadism practiced by the pre-neanderthal and neanderthal groups based on the settlements in the valley bottom, the upper adige alluvial plain and the mountain range. traces from ephemeral to consistent are scattered at 13001400 m a.s.l., peaking at 1600 m. caves presumably had a main role thanks to their strategic position, being favourable for catchment in different ecological environments through short-range movements. the variety of hunted animal species confirms the possibility to diversify the exploitation of resources of animal origin. if we add the possibility human groups had to easily access the primary exposures and secondary deposits of chert, we can argue that the presence of lower and middle palaeolithic hominins in this mountain range was driven by a set of factors (bagolini & broglio, 1985). whether mountain sites were the edge of a large settlement system extended to the po alluvial plain or were organized in a subsystem articulated in residential sites and specialized camps, it is however still far from being assessed. margaritora d. et al. acknowledgments the authors are grateful to dr. pietro sternai (department of earth and environmental sciences university of milano-bicocca) for suggestions on neotectonic upliftings, to tobia fognani and lucia bartolozzi for revision of the english text and to francesco carrer and ugo sauro who contributed thorough revision of this work with considerable amelioration. authors contributions: m.p. designed research, a.d., g.c., d.m. and m.c.t. produced data, all the authors wrote and edited the manuscript. references arzarello m., peretto c. (2005) nouvelles données sur les caractéristiques et l’évolution technoéconomique de l’industrie moustérienne de riparo tagliente (verona, italie). in moncel m-h., monnier j-l. (eds.) données recents sur les modalités de peuplement et sur le cadre chronostratigraphique, 281(9). british archaeological reports, international series 1364. aspes a., (1984) storia delle ricerche, in aspes a. (ed.) il veneto nell’antichità, preistoria e protostoria, verona, 3-39. aspes a. (2003) (ed.) preistoria veronese. contributi e aggiornamenti. memorie del museo civico di storia naturale di verona, ii serie, sezione scienze dell’uomo, n. 5. aspes a., borghesani g., castagna a., longo l., nicolis f., salzani l., simeoni g., zorzin r. (2002) carta archeologico-preistorica del comune di verona. elenco dei siti preistorici sulla base delle collezioni del museo di storia naturale e delle ricerche del nucleo operativo della soprintendenza archeologica del veneto. bollettino museo civico storia naturale di verona. geologia paleontologia preistoria, 26. avesani b., chelidonio g., sauro u., zanini f. (1986) terre rosse in lessinia: appunti sui significati geologici, preistorici e sugli usi tradizionali. la lessinia ieri oggi e domani, 83-102. bagolini b., broglio a. (1985) il ruolo delle alpi nei tempi preistorici (dal paleolitico al calcolitico). in studi di paletnologia in onore di s.m. puglisi, roma, 663-705. bartolomei g., broglio a. (1975) risultati preliminari delle nuove ricerche nei depositi quaternari della grotta a di veja. bollettino museo civico storia naturale di verona, 2, 217-238. bartolomei g., broglio a., cattani l., cremaschi m., guerreschi a., mantovani e., peretto c., sala b. (1982) i depositi würmiani del riparo tagliente. annali università di ferrara (nuova serie), sez. xv. paleontologia umana e paletnologia, vol. iii, 4, 61105. bartolomei g., cattani l., cremaschi m., pasa a., peretto c., sartorelli a. (1980) il riparo mezzena (stratigrafia del deposito, sedimenti, pollini, faune, industrie). memorie museo civico storia naturale di verona, ii serie, sezione scienze dell’uomo, 2. bartolomei g., broglio a., cassoli p., castelletti l., cremaschi m., giacobini g., malerba g., maspero a., peresani m., sartorelli a., tagliacozzo a. (1992) la grotte-abri de fumane. un site aurignacien au sud des alps. preistoria alpina, 28, 131-179. bartorelli u. (1967) tavole numeriche dell’assolazione annua. annali accademia italiana di scienze forestali, 16, 61-95. battaglia r. (1957) i più antichi abitatori del veneto. memorie accademia patavina ss.ll.aa., 69, 1-58. bertola s., peresani m., peretto c., thun hohenstein u. (1999) le site palèolithique moyen de la grotta della ghiacciaia (prèalpes de vènètie, italie du nord). l’anthropologie, 103, 377-390. bon m. piccoli g., sala b, (1991) i giacimenti quaternari di vertebrati fossili nell’italia nord-orientale. memorie di scienze geologiche, vol. xliii, 185-231. bosellini a., carraro f., corsi m., de vecchi g. p., gatto g. o., malaroda r., saturani c., ungaro s., zanettin b. (1967) note illustrative della carta geologica d’italia alla scala 1:100000. foglio 49 verona, ministero dell’industria del commercio e dell’artigianato. direzione generale delle miniere. servizio geologico d’italia, nuova tecnica grafica, roma. broglio a. (2002) paleolitico e mesolitico, in aspes a. (ed.) preistoria veronese. contributi e aggiornamenti. memorie museo civico storia naturale di verona, ii serie, sezione scienze dell’uomo, 5. broglio a., laplace g., zorzi f. (1963) i depositi quaternari del ponte di veja. le industrie. memore museo civico storia naturale di verona, 11, 325-367. brunetto l., chelidonio g. (1988) la valpolicella, ambiente paleolitico e preistorico. la lessinia ieri oggi e domani, 85-100. brunetto l., chelidonio g. (1990) nuovi rinvenimenti ed annotazioni per la conoscenza del sito paleolitico di cà verde di sant’ambrogio. annuario storico della valpolicella, 5-20. bosio l., capuis l. leonardi g., pesavento mattioli s., rosada g. (1990) carta archeologica del veneto, vol. ii. carraro f., malaroda r., piccoli g., sturani c., venzo s. (1969) note illustrative della carta geologica d’italia alla scala 1:100000. foglio 48 peschiera del garda, ministero dell’industria del commercio e dell’artigianato. direzione generale delle miniere. servizio geologico d’italia, poligrafica e cartevalori, ercolano. carton a., castaldini d., (1985) approfondimenti di morfotettonica tra il lago di garda e il torrente alpone (provincia di verona). bollettino museo civico storia naturale di verona, 12, 461-491. cassoli p.f., tagliacozzo a. (1994) considerazioni paleontologiche, paleoeconomiche e archeozoologiche sui macromammiferi e gli uccelli dei livelli del pleistocene superiore del riparo di fumane (vr) (scavi 1988-91). bollettino museo civico storia naturale di verona, 18, 349-445. castiglioni g.b., cremaschi m., guerreschi a., meneghel m., sauro u., van vliet lanoë b. (1990) the loess deposits in the lessini plateau, in cremaschi m. (ed.), the loess in northern and central italy: a loess basin between the alps and the mediterranean region. quaderni di geodinamica alpina e quaternaria, 1, 41-59. chelidonio g. (1980) vajo del trotto. bollettino museo 129 the lower and middle palaeolithic settlements in the baldo-lessini mountains. results from a gis investigation civico di storia naturale di verona, 7, 691-702. chelidonio g. (1995) tracce di officine litiche preistoriche a sant’anna d'alfaedo (verona). annuario storico della valpolicella, 7-22. chelidonio g. (1999) appunti sulle tracce litotecniche tardo-preistoriche lungo la dorsale da forte preara a cerro veronese (verona). quaderni di archeologia del veneto”, xv, 60-63. chelidonio g. (2000) tracce di frequentazione preistorica lungo la dorsale tra le valli di mezzane e d’illasi. quaderni di archeologia del veneto, 16, 51-57. chelidonio g. (2001a) tracce di officine litiche storiche e preistoriche sul monte gardon (tregnago). la lessinia ieri oggi e domani, 58-62. chelidonio g. (2001b) manufatti attribuiti al paleolitico medio nella bassa valpantena. quaderni di archeologia del veneto, 17, 89-92. chelidonio g. (2003) nuove tracce di officine litiche riferibili al paleolitico inferiore/medio in località pezza di castagnè (mezzane, vr). quaderni di archeologia del veneto, 19, 123-129. chelidonio g. (2004) scenari geologici "in movimento": il monte baldo come "macchina del tempo", in "paesaggio fra memoria e futuro. dal guardare al comprendere per progettare", cd, progetto infea. agenzia regionale protezione ambientale del veneto. chelidonio g. (2017) manufatti bifacciali paleolitici: alla ricerca di tracce post-acheuleane nei monti lessini, in m. cupitò, m. vidale e a. angelini (eds.) “beyond limits. studi in onore di giovanni leonardi”. padova university press, 223-234. chelidonio g., costa g. (2013) tracciati preistorici tra l’alta valpolicella, la valpantena e la valdadige. annuario storico della valpolicella, 13-28. chelidonio g., farello l. (1980) vaio del trotto (rosaro di cerro veronese-verona). memorie museo civico storia naturale verona, vii, 691-702. chelidonio g., farello l. (1987) monte cucco: un esempio tipico della continuità preistoria storia nella media lessinia. nuovi ritrovamenti e problemi della ricerca, della conservazione e della valorizzazione. la valpantena. quaderno culturale, 2, 12048. chelidonio g., farello l. (1996) grezzana. rinvenimenti paleolitici da monte gazzo. quaderni di archeologia del veneto, 12, 65-73. chelidonio g., farello l. (1997) verona. rinvenimenti paleolitici a ca’ pauli. quaderni di archeologia del veneto, 13, 78-80. chelidonio g., partesotti r. (1995) ritrovamenti archeologici nel veronese. mezzane, località guàite. quaderni di archeologia del veneto, 11, 63-66. chelidonio g., rosà v. (2011) tracce neandertaliane e manufatti musteriani sul monte baldo. il baldo, 22, 43-71. chelidonio g., rosà v. (2012) nuove tracce preistoriche sul monte baldo trentino e sul monte gazza (vezzano/tn). giudicaria, 80, 27-40. chelidonio g., sauro u. (1996) la montagna spaccata che fuma. la lessinia ieri oggi e domani, 51-63. chelidonio g., solinas a. (1977) orsara (lugo di grezzana). bollettino museo civico storia naturale 130 di verona, 4, 627-629. chelidonio g., solinas a., (1978) passo delle fittanze. preistoria alpina, 14, 228-231. chelidonio g., solinas a. (1983) un deposito paleolitico presso la contrada delle barozze in lessinia. la lessinia ieri, oggi e domani, 111-120. chelidonio g., stocchiero l. (1991) monte precastio (tregnago), prime note sulla nuova segnalazione di un sito riferibile al paleolitico inferiore e medio nella lessinia orientale. quaderni di archeologia del veneto, 7, 123-135. chelidonio g., farello l., franchetti d., partesotti r. (1978) zona di montecchio. bollettino del museo civico di storia naturale di verona, 5, 609-613. chelidonio g., farello l., partesotti r. (1986) preistoria sulle "torricelle". nuove scoperte ed ipotesi per le più antiche frequentazioni della collina veronese. la valpantena, 1, 9-25. chelidonio g., sauro u., stocchiero l. (1990) il sito paleolitico di s. giorgio in alta lessinia. la lessinia ieri, oggi e domani, 61-74. chelidonio g., sauro u., stocchiero l. (1992) nuovi ritrovamenti preistorici nell’alto vajo di squaranto. la lessinia ieri, oggi, domani, 127-143. chelidonio g., dozio a., rosà v. (2015) i più antichi abitanti dell’alto garda. judicaria, 89, 22-40. condemi s., mounier a., giunti p., lari m., caramelli d., longo l. (2013) possible interbreeding in late italian neanderthals? new data from the mezzena jaw (monti lessini, verona, italy). plos one, 8, 19. cremaschi m. (1984) i paleosuoli ed i depositi atriali delle cavità carsiche e dei ripari. in: aspes a. (a cura di), il veneto nell’antichità. preistoria e protostoria. banca popolare di verona, 101-113. cremaschi m. (1990) depositional and psotdepositional processes in rock shelters of northern italy during the late pleistocene: their paleoclimatic and paleoenvironmental significance. quaternaire, 1, 51-64. cremaschi m., ferraro f., peresani m., tagliacozzo a. (2005) il sito: nuovi contributi sulla stratigrafia, la cronologia, le faune a macromammiferi e le industrie del paleolitico antico, in a. broglio, g. dalmeri (a cura di) pitture paleolitiche nelle prealpi venete: grotta di fumane e riparo dalmeri. atti del simposio. memorie museo civico storia naturale verona, ii serie, sezione scienze dell’uomo 9, preistoria alpina, nr. speciale, 12-22. cremaschi m., meneghel m., sauro u., van vliet lanoe v. (1990) a case study: geomorphology of the fosse plateaux and the barozze profile, in m. cremaschi (ed.) the löess in northern italy: a löess basin between the alps and the mediterranean region. quaderni di geodinamica alpina e quaternaria, inqua commission on löess and palaeogeography, 56-59. curi e. (2001) la colonna stratigrafica di don gregorio piccoli (1680-1755). annuario storico della valpolicella”, 181-190. dalmeri g., duches r., rosà v. (2008) nuovi ritrovamenti del paleolitico medio sul monte baldo settentrionale. preistoria alpina, 43, 5-11. margaritora d. et al. de zanche v., sorbini l., spagna v. (1977) geologia del territorio del comune di verona. memorie museo civico di storia naturale di verona (ii s.), sez. sc. terra, 1, 51. ferraro f. (2009) age, sedimentation and soil formation in the val sorda loess sequence, northern italy. quaternary international, 204, 54-64. fortis a. (1786) delle ossa d'elefanti e d'altre curiosità naturali de' monti di romagnano nel veronese. stamperia turra, vicenza. garcia a. (2012) gis-based methodology for paleolithic site location preferences analysis. a case study from late paleolithic cantabria (northern iberian peninsula). journal of archaeological science, 40, 217-226. garcia a. (2013) to see or to be seen. . . is that the question? an evaluation of paleolithic sites’ visual presence and their role in social organization. journal of anthropological archaeology, 32, 647-658. garcia a., fano m.a., garate d. (2013) integrating spatial analyses into foraging-societies land use strategies. a case study from the nalón river basin (asturias, north of spain). proceedings of the 40th conference in computer applications and quantitative methods in archaeology, southampton, united kingdom, 26-30 march 2012, 670-677. latella l., sauro u. (2007) aspects of the evolution of an important geo-ecosystem in the lessinan mountain (venetian prealps, italy). time in karst, postojna. acta carsologica, 36/1, 69-75. leonardi p., broglio a. (1962) le paléolithique de la vénétie. annali università ferrara, 6, 1-118. lópez-garcía j.m., dalla valle c., cremaschi m., peresani m. (2015) reconstruction of the neanderthal and modern human landscape and climate from the fumane cave sequence (verona, italy) using small-mammal assemblages. quaternary science reviews, 128, 1-13. magaldi d., sauro u. (1982) landforms and soil evolution in some karstic areas of the lessini mountains and monte baldo (verona, northern italy). geografia fisica dinamica quaternaria, 5, 82-101. marazzi s. (2005) atlante orografico delle alpi. soiusa. quaderno di cultura alpina numero 82-83. martini m., sibilia e., croci s., cremaschi m. (2001) thermoluminescence (tl) dating of burnt flints: problems, perspectives and some example of application. journal of cultural heritage, 2, 179-190. massalongo a. (1851) osteologia degli orsi fossili nel veronese, con un saggio sopra le principali caverne del distretto di tregnago. naturwissensaftliche abhandlungen, iv, 58. mey j., scherler d., wickert a.d., egholm d.l., tesauro m., schildgen t.f., strecker m.r. (2016) glacial isostatic uplift of the european alps. nature communication 7, 13382. mietto p., sauro u. (2000) le grotte del veneto: paesaggi carsici e grotte del veneto, regione veneto. la grafica editrice, verona, 480. miller a., barton m. (2008) exploring the land: a comparison of land-use patterns in the middle and upper paleolithic of the western mediterranean. journal of archaeological science, 35, 1427-1437. pasa a. (1954) carsismo e idrografia carsica nel gruppo del monte baldo e nei lessini veronesi. tip. mareggiani, bologna, 150. pasa a. (1956) nuovi indici paleoclimatici dal deposito di quinzano veronese. atti accademia agricoltura, scienze & lettere di verona, serie vi, vol. vi, 39-60. pasotti m. (1970) punta musteriana rinvenuta sul monte baldo (verona). sibrium, 10, 14-18. peresani m. (2012) fifty thousand years of flint knapping and tool shaping across the mousterian and uluzzian sequence of fumane cave. quaternary international, 247, 125-150. peresani m., dalmeri g. (2000) i reperti musteriani del monte baldo settentrionale. preistoria alpina, 31, 511. peresani m., chrzavzez j. danti a., de march m., duches r., gurioli r., muratori s., romandini m., trombini l., tagliacozzo a. (2011a) fireplaces, frequentations and the environmental setting of the final mousterian at grotta di fumane: a report from the 2006-2008 research. quartär. international yearbook for ice age and stone age research, vol. 58. peresani m., fiore i., gala m., romandini m., tagliacozzo a. (2011b) late neandertals and the intentional removal of feathers as evidenced from bird bone taphonomy at fumane cave 44ky bp, italy. proceedings national academy of science, 108, 3888-3893. peresani m., delpiano d., duches r., gennai j., marcazzan d., nannini n., romandini m., aleo a., cocilova a. (2017) il musteriano delle unità a10 e a11 a grotta di fumane (vr). risultati delle campagne di scavo 2014 e 2016. fastionline documents & research, 397, 1-13. peresani m., potì a., visentin d., thun hohenstein u. (2018) at the western end. a discussion on the significance of a mousterian assemblage with leaf points discovered in northern italy. session xvi-1, the variability of bifacial tools in the middle palaeolithic and their importance in the transition to the upper palaeolithic in western eurasia: raw material, techno-typology, chronology and interactions in their environmental and cultural context. xviii congresso uispp, parigi, p. 26. peretto c. (1980) il paleolitico inferiore e medio nel territorio veronese (revisione e cronologia delle industrie), in fasani l. (ed.) il territorio veronese dalle origini all'età romana: contributi ed aggiornamenti di ricerca preistorica, 19-27. piccoli del faggiol g. (1739) ragguaglio di una grotta, ove sono molte ossa di belve diluviane nei monti veronesi, e dei luoghi in quei contorni; e strati di pietra, tra i quali stanno i corni ammoni; e ove si ritrovano altre produzioni maritime impietrite, e come in dissegno si dimostra. con rifflessioni sopra queste materie, stamperia fratelli merlo, verona. sauro u. (1973) il paesaggio degli alti lessini: studio geomorfologico. mem. fuori, serie 6, museo di storia naturale di verona, 160. sauro u. (2017) highlights of some human adventures in a karst environment: the case of the monti lessini (venetian prealps, italy). acta carsologica, 46/2-3, 131 the lower and middle palaeolithic settlements in the baldo-lessini mountains. results from a gis investigation 329-338. sauro u., zampieri d. (1999) una montagna in evoluzione. in: turri e. (ed.) il monte baldo. cierre edizioni., verona, 56-104. sorbini l. (ed.) (1993) geologia, idrogeologia e qualità dei principali acquiferi veronesi. memorie del museo civico di storia naturale di verona, ii serie, sezione scienze della terra, 4. sternai p., sue c., husson l., serpelloni e., becker t.w., willet s.d., faccenna c., di giulio a., spada g., jolivet l., valla p., petit c., nocquet j-m., walpersdorf a., castelltort s. (2019) present-day uplift of the european alps: evaluating mechanisms and models of their relative contributions. earthscience reviews, 589-604. talamo s., hajdinjak m., mannino m.a., fasani l., welker f., martini f., romagnoli f., zorzin r., meyer m., hublin j.j. (2019) direct radiocarbon dating and genetic analyses on the purported neanderthal mandible from the monti lessini (italy). scientific reports, 6, 29144. zampieri d. (2000) segmentation and linkage of the lessini mountains normal faults, southern alps, italy. tectonophysics, 319, 19-34. 132 zorzi f. (1959) un’amigdala acheuleana scoperta a lughezzano di valpantena nel quadro del paleolitico inferiore e medio veronese. memorie museo civico storia naturale di verona, vii, 297-334. zorzi f. (1960) preistoria veronese: insediamenti e stirpi, in verona e il suo territorio. istituto per gli studi storici veronesi, 75-152. zorzi f., pasa a. (1944-1945) il deposito quaternario di villa di quinzano. bullettino di paletnologia italiana, viii (1), 1-52.� margaritora d. et al. ms. received: july 7, 2020 revised: november 1, 2020 accepted: november 2, 2020 available online: december 20, 2020 base evoluzione geomorfologica quaternaria della conca intermontana di carsoli (aq) maurizio d’orefice1, francesco dramis2, elena graciotti3, roberto graciotti1 & michele soligo2 1ispra – dipartimento difesa del suolo-servizio geologico d’italia, roma. 2dipartimento di scienze geologiche, università “roma tre”, roma. 3libera professionista, via della grande muraglia, 46 roma. corresponding author: m. d’orefice <maurizio.dorefice@isprambiente.it> riassunto: d’orefice m. et al., evoluzione geomorfologica quaternaria della conca intermontana di carsoli (aq). (it issn 0394-3356, 2010). nel presente lavoro vengono esposti i risultati di uno studio a carattere geologico e geomorfologico, condotto nella conca intermontana di carsoli (aq), ubicata nell’appennino centrale, al confine tra le regioni abruzzo e lazio. si tratta di un’ampia depressione di origine tettonica, collocata nel punto di contatto tra due differenti domini paleogeografici, separati da un tratto della linea tettonica “olévano-antrodoco”. la conca di carsoli è colmata da una successione di sedimenti continentali di rilevante spessore ed estensione, i quali sono stati distinti in diverse unità litostratigrafiche. i sedimenti continentali più antichi affioranti all’interno dell’area in studio sono di origine lacustre (limi, argille e sabbie del bosco di oricola). essi sono caratterizzati da uno spessore massimo di circa 200 m e sono diffusi in quasi il 50% della conca, affiorando con una certa continuità nei suoi settori nord-occidentale e centrale (bosco di oricola); affioramenti isolati, invece, sono ubicati lungo il margine orientale della depressione. i sedimenti lacustri, la cui deposizione è probabilmente avvenuta tra il pleistocene inferiore ed il pleistocene medio, sono limitati verso l’alto da una antica superficie di erosione sub-orizzontale, di cui attualmente rimangono solo alcuni lembi relitti. ai depositi lacustri fanno seguito, lungo il bordo nord-orientale della conca di carsoli, sedimenti fluviali grossolani sospesi sull’attuale piana, deposti anticamente da un paleo-turano (ghiaie della madonna delle grazie). nella parte centro-occidentale e meridionale dell’area in esame, inizia bruscamente a partire da un’articolata superficie erosiva modellata nei depositi lacustri e nel substrato carbonatico meso-cenozoico, una significativa sequenza di terreni vulcanici di origine locale, datati intorno ai 530-540.000 anni dal presente. al loro interno sono state distinte tre unità piroclastiche principali, corrispondenti ad altrettanti membri: 1) brecce d’apertura di oricola scalo; 2) tufi grigi di oricola scalo; 3) tufi rossi di s. giovanni. di queste tre unità solo le ultime due affiorano ampiamente nell’area di studio. le brecce di oricola scalo sono relative alla fase d’apertura del condotto. esse consistono in strati di breccia a struttura massiva connessi a meccanismi deposizionali da caduta (airfall) e/o da debris flow, separati da livelli di tufo legati a fenomeni di base surge. i tufi grigi di oricola scalo sono costituiti essenzialmente da tufi cineritici grigi a lapilli, con laminazione incrociata da surge, e da tufi grigi a lapilli con struttura massiva da pyroclastic flow. i soprastanti tufi rossi di s. giovanni presentano, invece, uno spessore ed un’estensione areale maggiore di quella dei tufi grigi sottostanti. l’unità è prevalentemente formata da tufi rossi a lapilli, con strutture dunari o a laminazione parallela da surge e caduta (airfall). dopo la sedimentazione lacustre e alla fine degli episodi vulcanici, il territorio esaminato è stato interessato da un’intensa dinamica fluviale. questa ha portato alla sedimentazione, nel settore centro-meridionale ed orientale della conca, di estesi depositi alluvionali riconducibili ad eventi deposizionali differenti. lo studio lito-morfo-stratigrafico di questi depositi fluviali, integrato con diverse datazioni radiometriche, ha consentito una loro distinzione in quattro unità (ghiaie, sabbie e limi dei prati, conglomerati del fosso fioio, ghiaie, sabbie e limi dell’immagine, ghiaie, sabbie e limi del fiume turano) incastrate progressivamente le une nelle altre e di età variabile tra il pleistocene medio finale e l’attuale. all’interno dell’unità alluvionale riferibile al pleistocene medio finale è incassato un deposito carbonatico di origine continentale. si tratta di un orizzonte calcareo (calcareous tufa), datato a circa 46.000 ± 6.000 anni bp, che origina, in corrispondenza del settore meridionale della conca (fonte bosco), un corpo sedimentario di poche centinaia di metri di lunghezza e di 1,5 m di spessore massimo. per quanto riguarda le fasi deposizionali più recenti, particolarmente significativi si sono rivelati gli studio stratigrafici condotti sul conoide del fosso luisa (camerata nuova) e la datazione radiometrica di un orizzonte colluviale situato all’interno della sua porzione superiore. tale datazione, fornendo un’età calibrata di 3.550-3.400 anni bp, ha permesso una scansione temporale di alcuni eventi sedimentari ed erosivi che hanno caratterizzato la parte alta del conoide nell’olocene finale. abstract: d’orefice m. et al., quaternary geomorphological evolution of carsoli intermontane basin (l’aquila, italy). (it issn 03943356, 2010). in the present work the results of a geological and geomorphological study are presented. the study has been carried out in the carsoli intermontane basin (aq), a wide depression of tectonic origin, located between abruzzo and lazio regions, at the boundary of two different palaeogeographic domains, separated by the “olevano-antrodoco” tectonic line. the carsoli basin is filled with a continental sedimentary succession of considerable thickness and extent, which has been classified into several lithostratigraphic units, mainly on the basis of their lithological, morphological and geochronological characteristics. the oldest continental sediments outcropping within the study area are of lacustrine origin (bosco di oricola silts, clays and sands). these sediments, whose deposition has probably occurred in the lower – middle pleistocene, are characterized by a maximum thickness of about 200 m. they are widespread in the north-western and central parts of the basin (bosco di oricola) and are locally present on the eastern edge of the basin. the lacustrine deposits are cut across by an ancient sub-horizontal erosion surface, and at present, only some remnants remain. the lacustrine sediments are covered, on the north-eastern edge of the basin, by coarse fluvial sediments suspended on the present plain, originally deposited by the paleo-turano river (madonna delle grazie gravels). in the central-western and southern part of the study area, a significant sequence of local volcanic deposits, dated around 530 – 540 kyears bp, outcrops. the volcanic sequence abruptly begins from an articulated erosive surface shaped in lacustrine deposits and meso-cenozoic carbonatic bedrock. three main pyroclastic units are distinguished in the following members: 1) oricola scalo opeil quaternario italian journal of quaternary sciences 23(1), 2010 55-74 56 m. d’orefice et al. 1. introduzione la conca intermontana di carsoli (aq) riveste un particolare interesse nell’ambito della geologia del quaternario e della geomorfologia, in quanto: i) è colmata da un’articolata successione di sedimenti continentali di rilevante spessore ed estensione; ii) è sede di un peculiare vulcanismo monogenico locale medio-pleistocenico. lo scopo del presente lavoro è quello di delineare le principali tappe morfoevolutive che hanno caratterizzato la conca di carsoli nel corso del quaternario mediante l’utilizzo di dati litostratigrafici, geomorfologici e geocronologici, acquisiti nell’ambito di diverse ricerche condotte a partire dalla fine degli anni ’90. i dati litostratigrafici e geomorfologici inerenti i depositi continentali sono stati in gran parte tratti dai rilevamenti alla scala 1:10.000, effettuati nell’ambito della realizzazione del foglio geomorfologico 367 “tagliacozzo” (apat servizio geologico d’italia, 2009; chiarini et alii, 2009). considerata la rarità e la discontinuità degli affioramenti dei depositi quaternari, i rilevamenti di campagna sono stati integrati con dati ricavati sia da sondaggi geognostici già esistenti, sia da nuovi sondaggi elettrici verticali (servizio geologico nazionale, 1998), sondaggi meccanici a carotaggio continuo (servizio geologico nazionale, 2000), trincee a mano e perforazioni realizzate mediante trivella manuale. le informazioni litostratigrafiche e tettoniche relative al substrato marino, invece, sono state desunte dal corrispondente foglio geologico “tagliacozzo” (servizio geologico d’italia, 2005; compagnoni et alii, 2005) e in parte integrate dai rilevamenti originali di alcuni autori del presente lavoro. il quadro litostratigrafico è stato arricchito con dati geocronologici desunti da diverse determinazioni isotopiche, riportate oltre che in bosi et alii (1991), in lavori precedenti svolti anche da alcuni autori di questa nota (barbieri et alii, 1998; d’orefice et alii, 2006; dramis et alii, 2008). 2. studi precedenti i primi lavori geomorfologici che hanno interessato l’area in studio sono quelli dell’elvetico bieler-chatelan (1928, 1929, 1930, 1931), il quale nelle sue numerose pubblicazioni sostiene che molte forme e depositi ivi presenti siano stati originati da un vasto ghiacciaio “polisintetico”, che scendendo lungo le cinque valli confluenti nella conca di carsoli, superava la stessa, per poi proseguire con due lingue nelle valli dell’aniene e del turano. tale ipotesi viene prontamente contestata da gortani (1930a, 1930b, 1931) e qualche anno dopo anche suter (1934, 1939) si convince della scarsa veridicità delle affermazioni dello studioso svizzero. con la pubblicazione del foglio 145 “avezzano” (regio ufficio geologico, 1934), privo tra l’altro di note illustrative, viene delineato un primo quadro geologico generale dell’area. in questo foglio vengono cartografate, su gran parte del fondo della conca, “alluvioni terrazzate del quaternario recente”, mentre lungo i bordi della depressione sono state rappresentate “conoidi abbandonate” e “detriti di falda”. solamente al centro della conca appaiono dei depositi vulcanici, descritti come “tufi più o meno cementati”. successivamente, in uno studio geomorfologico di carattere regionale, demangeot (1965) ipotizza l’origine della depressione per fenomeni carsici al di sotto della copertura “molassica”. egli, inoltre, in accordo con segre (1953), presuppone che lo svuotamento dell’antico lago di carsoli sia avvenuto progressivamente attraverso l’escavazione della forra del fosso bagnatore, indotta da una ripresa dell’attività tettonica nel settore compreso tra riofreddo ed arsoli. di filippo & toro (1979), nell’ambito d’indagini gravimetriche atte ad ottenere dati sull’andamento strutturale profondo dei m.ti simbruini, hanno evidenziato un minimo gravimetrico nella conca di carsoli, che imputano alla bassa densità degli “estesi e potenti” sedimenti lacustri ivi affioranti. raffy (1979) accentra la sua attenzione su un ning–vent breccias, 2) oricola scalo grey tuffs, 3) s. giovanni red tuffs. only the last two units widely outcrops in the study area. the oricola scalo opening-vent breccias are relative to the early opening phase of the conduit. they consist of a massive structure connected to the depositional mechanisms of airfall and/or debris flow, separated by tuff layers related to base surge phenomena. the oricola scalo grey tuffs unit mainly consists of grey ash-lapilli tuffs with surge cross-laminations, and grey lapilli tuffs with a massive structure of pyroclastic flow. the overlying s. giovanni red tuffs are characterized, instead, by a thickness and distribution greater than that of underlying grey tuffs. the unit is mainly composed of red lapilli tuffs, with dune structures or a parallel lamination of surge and airfall. after the lacustrine sedimentation and the volcanic episodes, the examined area underwent intense fluvial dynamics. this led to the sedimentation, in the central-southern and eastern part of the basin, of a sequence of alluvial deposits belonging to different depositional events. the morpho-litho-stratigraphic analysis of these fluvial deposits, in addition with radiometric ages, allowed for their classification into four units (prati gravels, sands and silts, fioio stream conglomerates, immagine gravels, sands and silts, turano river gravels, sands and silts) progressively embedded into each other and ranging in age between the late middle pleistocene and the present. entrenched in the late middle pleistocene alluvial unit, in the southern sector of the basin (fonte bosco), a few hundred meters long and 1.5 meters thick calcareous tufa layer, dated by u-series method at 46,000 ± 6,000 years bp outcrops. with regard to the most recent depositional phases, great relevance has to be ascribed to the stratigraphic study carried out on the fosso luisa fan (camerata nuova) and the radiometric dating of colluvial horizon, there present. this dating, providing a calibrated 14c age of 3,550-3,400 years bp, has allowed for a temporal definition of some sedimentary and erosive events that marked the upper part of the fan during the final part of holocene. parole chiave: geologia del quaternario, geomorfologia, bacini continentali intermontani, oricola-carsoli (l’aquila). keywords: quaternary geology, geomorphology, intermontane continental basins, oricola–carsoli (l’aquila). deposito fluviale molto grossolano, affiorante sulla collina calacorte (625 m s.l.m.), a sud di poggio cinolfo, e in base a considerazioni sull’energia del mezzo, correla questi depositi fluviali con quelli ubicati più a valle, a nord di turania, dove essi però superano gli 800 m di quota. la differenza altimetrica viene giustificata, dall’autrice, mediante la presenza, tra vivaro romano e poggio cinolfo, di faglie dirette a direzione appenninica ed antiappenninica, che ribassano i depositi fluviali di calacorte. ciò, unito ad altre considerazioni, induce la raffy ad ipotizzare un’origine tettonica della depressione, la quale a suo avviso è stata sede di un’unica sedimentazione lacustre, prodottasi in condizioni climatiche umide e conclusasi con un episodio vulcanico. l’abbondanza delle vulcaniti e le dimensioni dei minerali in esse contenuti, portano l’autrice ad escludere una loro origine lontana e a supporre una provenienza di questi prodotti da condotti vulcanici locali, analoghi a quelli di m. autore e della valle dell’aniene. in uno schema morfologico regionale raffy (1979, 1981/82) attribuisce i sedimenti lacustri, compresi i depositi vulcanici, al pleistocene medio. successivamente, informazioni a carattere generale vengono fornite dalla “carta delle litofacies del lazio-abruzzo” (accordi et alii, 1986), dove, data la scala 1:250.000, gli unici sedimenti continentali cartografati, nell’area in esame, sono costituiti da “depositi argillosi-sabbiosi contenenti molluschi lacustri stratigraficamente poco significativi (plio-pleistocene indifferenziato)”. detti (1988), nell’ambito di una tesi di laurea, ha eseguito un rilevamento alla scala 1:10.000 dell’intero bacino, finalizzato a delinearne l’evoluzione geologica plio-pleistocenica. la successione continentale affiorante viene suddivisa nelle seguenti formazioni progressivamente incassate le une nelle altre: “sabbie e limi di oricola”, “vulcaniti di civita”, “tufiti di s. giovanni”, “limi e sabbie vulcaniche dei prati”, “conglomerati di fontanelle brecciaro”, “ghiaie di pisciarello”, “ghiaie di calacorte”, “sabbie e ghiaie della piana”, “ghiaie del macerone”, “detriti di falda e coltri colluviali”. le “sabbie e limi di oricola” sono state attribuite al pleistocene inferiore finale – pleistocene medio, le “vulcaniti di civita” e i “tufi di s. giovanni” ipoteticamente a 600.000 anni dal presente, la successione compresa tra i “limi e sabbie vulcaniche dei prati” e le “ghiaie di calacorte” al pleistocene medio-superiore e i restanti depositi all’olocene. a partire dagli anni ’90, una certa attenzione viene riservata ai prodotti vulcanici affioranti in questa zona, nei cui riguardi prima bosi et alii (1991) e poi bosi & locardi (1991/2) ipotizzano un’origine locale, sulla scorta di argomentazioni geologiche e per la prima volta geochimiche. colica et alii (1995), nell’ambito di uno studio di geologia del quaternario esteso a buona parte della conca di carsoli, individuano cinque unità morfo-litopedo-stratigrafiche che rappresentano su una carta geologica schematica alla scala 1:42.000. tali unità, la cui attribuzione cronologica è stata effettuata dagli autori essenzialmente in base alle caratteristiche litologiche ed al grado di sviluppo pedogenetico dei suoli, sono costituite da “depositi lacustri del pleistocene inferiore-pleistocene medio”, da “vulcaniti e tufiti di oricola, del pleistocene medio” di origine locale e da 57evoluzione geomorfologica quaternaria ... tre corpi sedimentari (“unità q3”, “unità q2” e “unità q1”) formati da depositi alluvionali compresi tra un generico pleistocene e l’olocene. questi autori, infine, in base ad una correlazione tra lineazioni, unità morfolito-stratigrafiche e tipologia del reticolo idrografico, ipotizzano un’influenza neotettonica nell’evoluzione quaternaria della conca. una successiva pubblicazione (lorenzoni et alii, 1995) è dedicata alla “carta dei suoli della conca intramontana tra oricola e carsoli (provincia dell’aquila)”. tra la fine degli anni ’90 e i primi anni del secolo attuale, grazie ai nuovi dati provenienti dal rilevamento del foglio geologico e geomorfologico 367 “tagliacozzo” in scala 1:50.000 (servizio geologico d’italia, 2005; compagnoni et alii, 2005; apat servizio geologico d’italia, 2009; chiarini et alii, 2009), vengono realizzati nuovi studi a carattere geomorfologico, vulcanologico, petro-mineralogico e geochimico (barbieri et alii, 1997, 2000; d’orefice & graciotti, 2005; d’orefice et alii, 2006; dramis et alii, 2008). 3. inquadramento geografico e geologico la conca intermontana di carsoli è situata nel settore occidentale dell’appennino centrale, al confine tra le regioni abruzzo e lazio, ed è compresa interamente all’interno del bacino idrografico del fiume turano (fig. 1). si tratta di un’ampia depressione chiusa, sede di un antico e vasto bacino lacustre, in cui sono andati a confluire forti spessori di depositi continentali, costituiti essenzialmente da sedimenti lacustri ed in minor misura da depositi fluviali strictu sensu, di conoide alluvionale e di versante. sotto il profilo fisiografico la parte più depressa della conca di carsoli è contraddistinta da un ampia superficie di circa 40 km2 di estensione, sviluppata pressappoco tra la quota massima di 750 m s.l.m. (estremo settore meridionale) e la quota minima di 565 m s.l.m. (estremo settore settentrionale). tale superficie, caratterizzata da un perimetro sinuoso sul lato orientale e meridionale della conca e più regolare su quello occidentale e settentrionale, presenta in pianta una forma pressappoco ellittica, con asse maggiore, a direzione nno-sse, lungo circa 12 km ed asse minore, ortogonale al primo, di circa 6 km di lunghezza (fig. 1). la conca è profondamente incassata nei rilievi circostanti, i quali si affacciano sulla stessa con quote che raggiungono i 1.200 m circa s.l.m. in corrispondenza del sua porzione più meridionale. complessivamente il fondo della depressione può essere considerato sub-pianeggiante, ma ad un esame più accurato questo risulta abbastanza irregolare. esso, infatti, è caratterizzato da un microrilievo costituito da una serie di collinette che si ergono all’incirca dai 20 ai 40 metri al di sopra delle piane alluvionali attuali del f. turano e del reticolo idrografico ad esso affluente. in linea di massima possono essere distinte due principali zone collinari, separate da una stretta area pianeggiante, a forma di “z”, percorsa dai fossi fioio e cammarano e dal f. turano (fig. 1). il f. turano rappresenta l’asta principale, che percorre la parte più depressa della conca con un tracciato caratterizzato da repentini cambi di direzione. esso, infatti, in prossimità del centro abitato di carsoli devia sedimenti calcarei e calcareomarnosi miocenici (fig. 2). il lato nord-occidentale della depressione è delimitato da una serie di rilievi meno elevati e fittamente boscati, la cui continuità è interrotta verso oriente dalla valle del f. turano (f ig. 1). questi rilievi sono formati da torbiditi prevalentemente arenacee ed arenaceo-pelit iche deposte nell’avanfossa messiniana (fig. 2). i rilievi modellati sui sedimenti torbiditici messiniani proseguono verso ne, bordando il lato nord-orientale della conca. su di essi sono ubicati i paesi di collalto sabino (980 m s.l.m.), poggio cinolfo (713 m s.l.m.) e carsoli (650 m s.l.m.) (figg. 1 e 2). la conca è chiusa, sul suo lato sud-orientale, da una serie di dorsali dall’andamento prevalentemente appenninico. si tratta dei rilievi carbonatici di età cretacico-miocenica, appartenenti alle propaggini nord-occidentali dei monti simbruini, alla cui base è arroccato il paese di pereto (878 m s.l.m.) (figg. 1 e 2). sempre ai monti simbruini nord-occidentali appartiene il rilievo su cui sorge oricola (810 m s.l.m.), che, con andamento nno-sse, chiude il lato sud-occidentale della conca di carsoli (figg. 1 e 2). la parte più meridionale della depressione, si va ad incuneare all’interno dei rilievi simbruini, restringendosi, f ino a chiudersi, in corrispondenza di camerata nuova (810 m s.l.m.). dal punto di vista paleogeografico la conca di carsoli è situata in prossimità del contatto tra due differenti domini meso-cenozoici. ad est ed a sud-est le strutture dei rilievi calcarei dei monti simbruini sono, infatti, in facies di piattaforma interna laziale-abruzzese e risultano allineate prevalentemente in direzione nose, mentre ad ovest i litotipi appartenenti alle strutture calcaree e calcareo-marnose dei monti sabini sono in facies sabina di transizione tra la piattaforma carbonatica ed il bacino umbro-marchigiano ed hanno un andamento meridiano (fig. 2). questi due domini paleogeografici sono separati da un tratto della linea tettonica “olèvano-antrodoco” (damiani, 1984; cavinato et alii, 1986; cosentino & parotto, 1991; cipollari & cosentino, 1992), “ancona-anzio” auctt. (castellarin et alii, 1978), che con andamento circa n-s borda il piede dei monti sabini orientali, originando, a seguito dei fenomeni erosivi, una netta rottura di pendio (fig. 1). tra i due domini sono interposti tettonicamente i depositi silicoclastici, terrigeni, dell’avanfossa messiniana. le vicende tettoniche che hanno interessato l’area sono inquadrabili all’interno di un contesto più generale che ha riguardato l’appennino laziale-abruzzese. nel messiniano questo settore appenninico viene completamente implicato nelle fasi compressive dell’o58 bruscamente di circa 50° verso so per entrare nella conca omonima (figg. 1 e 2). dopo un altro rapido cambiamento di direzione di circa 70°, in corrispondenza della confluenza con il fosso cammarano, suo affluente di sinistra, il turano assume una direzione appenninica, che manterrà sino alla confluenza con il fosso carcarone, altro suo affluente di sinistra. da questo punto in poi il fiume devia di circa 40° verso nord ed esce dalla depressione. il reticolo ad esso affluente è contraddistinto da densità di drenaggio, grado di gerarchizzazione e pattern differenti da settore a settore della conca, in funzione dei litotipi affioranti. in particolare, nel settore centro-occidentale (bosco di oricola), il reticolo idrografico è ben organizzato secondo un pattern sub-dendritico, con direzione prevalente delle aste principali no-se e nne-sso e una densità di drenaggio elevata. nel settore settentrionale e nord-orientale del bacino in esame (tra poggio cinolfo e villa romana) il reticolo idrografico mostra un pattern dendritico, ben gerarchizzato, con direzione prevalente delle aste neso e in subordine e-o. i quadranti meridionali della depressione sono invece contraddistinti da un reticolo sub-parallelo, poco o nulla gerarchizzato e con bassa densità di drenaggio, ad andamento da ono-ese a nno-sse. il lato occidentale della conca è demarcato da un allineamento di monti a direzione n-s, su cui sorgono i paesi di vallinfreda e vivaro romano (fig. 1). tali rilievi, che raggiungono i 1.000 m di altezza, appartengono alle dorsali più orientali dei monti sabini, costituite da fig. 1 rilievo ombreggiato della conca di carsoli ricavato dal modello digitale del terreno con risoluzione di 20 m. nel riquadro, localizzazione dell’area in studio. shaded relief of the carsoli basin obtained from a 20 m resolution digital terrain model. the study area is enclosed in the box. m. d’orefice et al. 59 rogenesi appenninica, che hanno determinato piegamenti ed accavallamenti vergenti verso ne, come ad esempio il fronte dei simbruini. alla fase tettonica messiniana fa seguito, nel pliocene inferiore, una nuova fase, che determina la sovrapposizione, verso est, del dominio di transizione su quello di piattaforma lungo la citata linea “olevano antrodoco”. questa linea avrebbe, quindi, le caratteristiche di un elemento tettonico fuori sequenza rispetto alla generale successione temporale e spaziale con cui si sono sviluppati i principali fronti di sovrascorrimento della catena appenninica, in progressiva migrazione verso est (cipollari & cosentino, 1992). la catena appena strutturata è stata in seguito interessata da un’intensa fase tettonica distensiva plioquaternaria, che ha ribassato estesi settori della catena stessa, mediante la genesi di numerose faglie dirette e la riattivazione di rampe di thrust come faglie normali a basso angolo; è questo il caso dell’importante faglia del fosso fioio (damiani, 1990; compagnoni et alii, 1993) che, con un decorso pressoché parallelo alla valle omonima (fig. 2), separa le dolomie e i calcari del cretacico inferiore a ne, dai calcari del cretacico superiore – miocene a so, con un rigetto reale di circa 1.500 m. per quanto concerne l’evoluzione tettonica della conca di carsoli, scarsi sono gli elementi e le evidenze di campagna che possano consentire una ricostruzione abbastanza attendibile, come anche rare sono le pubblicazioni su tale argomento riguardanti quest’area e le zone ad essa limitrofe. tra queste può essere citato il lavoro di cavinato et alii (1986), che analizza le caratteristiche strutturali di un’ampia fascia (circa 30 km) a cavallo del settore centrale della l inea “olévano antrodoco”, e quello di ambrosetti et alii (1987), finalizzato alla realizzazione della “carta neotettonica d’italia”. nel lavoro di cavinato et alii (1986), in cui almeno 15 stazioni di misura per l’analisi strutturale ricadono lungo il perimetro della fig. 2 schema geologico dell’intera conca di carsoli (modificato da d’orefice & graciotti, 2005). legenda: 1) ghiaie sabbie e limi del fiume turano flt e depositi colluviali (tardoolocene – attuale); 2) ghiaie, sabbie e limi dell’immagine – fli (12,5-11,9 ÷ 4,1-3,9 ka cal bc; tardoglaciale – olocene iniziale); 3) conglomerati del fosso fioio cof (pleistocene superiore); 4) tufi calcarei di fonte bosco – cfb (46 ± 6 ka bp, metodo u/th; pleistocene superiore); 5) ghiaie, sabbie e limi dei prati – flp (pleistocene medio finale); 6) depositi piroclastici indifferenziati (531 ÷ 540 ka bp, metodo 40ar/39ar e rb/sr; pleistocene medio); 7) ghiaie della madonna delle grazie – flg (pleistocene medio iniziale); 8) limi, argille e sabbie del bosco di oricola – lao (pleistocene inferiore pleistocene medio iniziale); 9) sedimenti terrigeni: torbiditi silicoclastiche e marne a orbulina (miocene superiore); 10) sedimenti carbonatici in facies sabina di transizione (miocene inferiore – medio); 11) sedimenti carbonatici in facies laziale-abruzzese di piattaforma (cretacico inferiore – miocene medio); 12) sovrascorrimento (tratteggiato: non affiorante); 13) faglia diretta (tratteggiata: non affiorante); 14) datazioni radiometriche. geological scheme of the full carsoli basin (modified from d’orefice & graciotti, 2005). legend: 1) turano river silts, clays and sands – flt and colluvial deposits (late holocene – present); 2) immagine gravels, sands and silts – fli (12.5-11.9 ÷ 4.1-3.9 cal ka bc; late glacial – early holocene); 3) fioio stream conglomerates cof (upper pleistocene); 4) fonte bosco calcareous tufa – cfb (46 ± 6 ka bp, u/th method; upper pleistocene); 5) prati gravels, sands and silts – flp (late middle pleistocene); 6) undifferentiated pyroclastic deposits (531 ÷ 540 ka bp, 40ar/39ar and rb/sr methods; middle pleistocene); 7) madonna delle grazie gravels flg (early middle pleistocene); 8) bosco di oricola silts, clays and sands – lao (lower pleistocene – early middle pleistocene); 9) terrigenous sediments: siliciclastic turbidites and orbulina marls (upper miocene); 10) transitional «sabina» facies carbonatic sediments (lowermiddle miocene); 11) «laziale-abruzzese» platform facies carbonatic sediments (lower cretaceous – middle miocene); 12) overthrust (hatched: not outcropping); 13) normal fault (hatched: not outcropping); 14) radiometric dating. evoluzione geomorfologica quaternaria ... 60 conca, sono state individuate quattro fasi tettoniche, di cui tre compressive, avvenute tra i l tortonianomessiniano e il pliocene inferiore, ed una distensiva tra il pliocene medio e l’attuale. la prima fase compressiva è contraddistinta da sistemi coniugati di faglie inverse a direzione appenninica e localmente da sistemi trascorrenti. a questa fase segue un episodio distensivo, che ha generato sistemi di faglie dirette con direzione nose. la seconda fase compressiva ha causato la formazione di strutture plicative ad asse prevalente n-s e sistemi coniugati di faglie inverse n20°o, a cui sono associate faglie di trascinamento orientate mediamente n70°e. la terza fase compressiva, meno evidente e diffusa delle precedenti, ha originato sistemi coniugati inversi e pieghe con cerniere ne-so. la fase distensiva finale è rappresentata da sistemi coniugati di faglie dirette e faglie verticali n-s ed e-o, che dislocano chiaramente le strutture compressive preesistenti e, in particolare, la linea “olevano antrodoco”. nella “carta neotettonica d’italia” (ambrosetti et et alii, 1987), la conca di carsoli risulta caratterizzata, a partire dal pliocene inferiore e medio, prima da un sollevamento, poi nel pliocene medio e superiore da un abbassamento, seguito da una risalita; nel pleistocene inferiore si sarebbe nuovamente verificato un abbassamento, seguito a partire dal pleistocene medio da un sollevamento. prospezioni geofisiche, realizzate dal servizio geologico nazionale (1998) su tutta la depressione per ricostruire l’andamento nel sottosuolo del substrato carbonatico e torbiditico, hanno evidenziato la presenza di diverse linee di discontinuità che isolano il bedrock secondo blocchi. questi sono delimitati da linee di discontinuità principali che, con orientamento n-s e nno-sso, interessano l’intero sottosuolo della conca e da discontinuità di lunghezza minore allineate in direzione ono-ese, ne-so, no-se e e-o. la disposizione relativa dei vari blocchi dà luogo ad alti e bassi strutturali al di sotto della successione continentale che ricopre in discordanza il substrato. in corrispondenza del bosco di oricola è stata registrata la massima profondità del tetto del substrato carbonatico, con quote che scendono al di sotto del livello del mare, fino a raggiungere la profondità di oltre 650 m dal piano campagna. 4. litostratigrafia del substrato pre-quaternario le rocce più antiche della successione carbonatica di piattaforma, risalgono agli inizi del cretacico inferiore e si rinvengono esclusivamente lungo la valle del fosso fioio, dove affiorano, per diverse centinaia di metri di spessore, alternanze calcareo-dolomitiche passanti verso l’alto a dolomie (“dolomie del fosso fioio”). in continuità stratigrafica seguono i “calcari a requienidi” dell’aptiano-cenomaniano, formati da calcari, calcari dolomitici e dolomie, e i “calcari a radiolitidi” del cretacico superiore. nella parte più occidentale dei m.ti simbruini (tra arsoli, pereto e camerata nuova), la successione cretacica di piattaforma carbonatica si chiude con i “calcari saccaroidi ad orbitoidi” (?campaniano p.p. – maastrichtiano p.p.), formati da calcari di spessore modesto intensamente ricristallizzati. dopo la cosiddetta “lacuna paleogenica”, la sedimentazione carbonatica continua con la deposizione delle “calcareniti arancioni ad echinidi” del (?)burdigaliano langhiano p.p.. tale unità, in genere paraconcordante sui calcari del cretacico superiore, affiora con spessori esigui in corrispondenza dei rilievi simbruini che si affacciano sulla conca di carsoli. in successione stratigrafica sulle “calcareniti arancioni ad echinidi” si rinviene la formazione dei “calcari a briozoi e litotamni” (langhiano p.p. – serravalliano p.p.) costituita da calcareniti bioclastiche biancastre ben stratificate. questa formazione, con uno spessore di un centinaio di metri, occupa gran parte del settore sud-orientale, meridionale e sud-occidentale dell’area in esame e presenta dei caratteri parzialmente diversi nelle strutture laziali-abruzzesi e in quelle sabine. della successione sabina di transizione nell’area in studio affiora solo la “formazione di guadagnolo” (aquitaniano p.p. – langhiano (serravalliano p.p.)), costituita da marne, calcari marnosi e livelli calcarenitici, con lenti di selce ed abbondanti spicole di spugna. questa formazione, presente esclusivamente lungo il margine occidentale della conca di carsoli, passa gradualmente a quella sopraccitata dei “calcari a briozoi e litotamni”. al di sopra dei calcari miocenici si rinvengono termini terrigeni appartenenti alla formazione delle “marne a orbulina” del serravalliano p.p. – messiniano inferiore, che testimoniano l’iniziale impostazione del bacino di avanfossa del liri-tagliacozzo. questa formazione, costituita da calcareniti, calcari marnosi, marne e argille, affiora, in fasce strette ed allungate di modesto spessore, solo lungo il margine occidentale della conca. alle marne a orbulina seguono stratigraficamente torbiditi silicoclastiche che avrebbero colmato, nel messiniano inferiore, il bacino di avanfossa sopra riportato (“unità arenaceo-pelitica del liri-tagliacozzo”). nell’area in studio le torbiditi sono prevalentemente arenacee, in strati molto spessi, con rare intercalazioni di litofacies arenaceo-pelitiche e pelitico-arenacee in strati sottili e molto sottili. lungo il bordo nord-orientale della conca, tra poggio cinolfo e carsoli, le arenarie torbiditiche sono caratterizzate da intercalazioni di livelli conglomeratici poligenici e di calcareniti grossolane, nonché dalla presenza di olistoliti calcarei. le torbiditi affiorano essenzialmente lungo il margine settentrionale e nord-orientale della conca, nei dintorni di riofreddo e a nord di oricola (fig. 2). in corrispondenza del settore nord-orientale dei m.ti simbruini, al di fuori dell’area in studio, la sedimentazione terrigena ha dato invece luogo, nel tortoniano messiniano inferiore, alla formazione di spessi depositi poligenici, prevalentemente psefitici, d’origine marina, denominati “brecce della renga” (devoto 1967a; 1967b). 5. litostratigrafia delle successioni continentali dopo una generale emersione, i prodotti originati dallo smantellamento dei rilievi meso-cenozoici, per opera degli agenti esogeni, hanno dato luogo ad una serie di depositi continentali quaternari, che si sono andati ad accumulare all’interno della depressione di carsoli. lo spessore di questi depositi è elevato, come m. d’orefice et al. evidenziato dalle indagini gravimetriche effettuate da di filippo & toro (1979) nel settore sudorientale della conca stessa; più precisamente esso può abbondantemente superare i 200 m circa, sulla scorta dei dati ricavati dalle prospezioni geofisiche realizzate dal servizio geologico nazionale (1998). i depositi continentali quaternari individuati nell’area in esame sono stati distinti in diverse unità, essenzialmente sulla base delle loro caratteristiche litostratigrafiche e delle morfologie ad essi associate (fig. 3). in quest’ambito non si è fatto ricorso alle unità sintemiche, poiché il riconoscimento di superfici di discontinuità significative e dimostrabili si è rivelato molto difficoltoso a causa della rarità degli affioramenti. complessivamente, nell’ambito della successione continentale sono stati individuate le seguenti formazioni, elencate a partire dalle più antiche: • limi, argille e sabbie del bosco di oricola (lao). • ghiaie della madonna delle grazie (flg). • vulcaniti della conca di carsoli: membro delle brecce d’apertura di oricola scalo (bao). membro dei tufi grigi di oricola scalo (tgo). membro dei tufi rossi di s. giovanni (trg). • ghiaie, sabbie e limi dei prati (flp). • tufi calcarei di fonte bosco (cfb). • conglomerati del fosso fioio (cof). • ghiaie, sabbie e limi dell’immagine (fli). • ghiaie, sabbie e limi del fiume turano (flt). • colluvi e detriti di versante (cdv). 5.1. limi, argille e sabbie del bosco di oricola (lao) i limi, argille e sabbie del bosco di oricola costituiscono i depositi continentali più antichi presenti all’interno della conca (fig. 3). questi sedimenti, confinati unicamente nel bacino attuale, affiorano in circa il 50% dell’area in esame, rinvenendosi con una certa continuità in tutto il settore nordoccidentale e in parte centrale della stessa (bosco di oricola) (fig. 2). lembi isolati si rinvengono a col farolo e zone limitrofe, lungo il fosso rientro, a nord di colle s. vito e in corrispondenza del bordo orientale e nord-orientale della depressione (convento di s. francesco e dintorni). nel settore nord-occidentale della conca la quota massima di affioramento è di 637 m, mentre la quota minima è di 575 m s.l.m., invece a col farolo la formazione affiora tra 658 m e 595 m s.l.m. comunque, è lungo il margine orientale e nord-orientale che essa raggiunge le altezze più elevate, come ad esempio nell’area del convento di s. francesco. partendo da questa località e procedendo verso ne, le quote massime di affioramento variano, infatti, da 630 m a 730 m circa, mentre gli spessori massimi si mantengono costantemente intorno ai 20-30 m. i depositi in esame si presentano ben stratificati e contraddistinti da alternanze di strati argilloso-limosi di colore grigio-azzurro e sabbioso-limosi di colore giallognolo; quest’ultimi sono più frequenti nella parte più alta della formazione, evidenziando un trend di tipo coarsening-upward (cu). gli strati, di spessore variabile da qualche centimetro ad un metro, hanno una forma tabulare alla scala dell’affioramento e sono delimitati da superfici piane e parallele (fig. 4). internamente essi sono caratterizzati da una sottile laminazione prevalentemente di tipo piano-parallela. gli strati sabbioso-limosi sono interessati da diffuse screziature ocra legate a fenomeni di ossidazione dei minerali ferrosi. frequentemente il passaggio da strati sabbioso-limosi a sottostanti strati argilloso-limosi è contrassegnato da patine di alterazione limonitiche e da tasche e lobi da carico. queste strutture da carico fanno sì che il limite tra uno strato e l’altro a volte sia leggermente ondulato. 61 fig. 3 ricostruzione schematica dei rapporti morfo-litostratigrafici tra le varie unità sedimentarie continentali individuate all’interno della conca di carsoli (non in scala). lao = limi, argille e sabbie del bosco di oricola; flg = ghiaie della madonna delle grazie; bao = brecce d’apertura di oricola scalo; tgo = tufi grigi di oricola scalo; trg = tufi rossi di s. giovanni; flp = ghiaie, sabbie e limi dei prati; cfb = tufi calcarei di fonte bosco; cof = conglomerati del fosso fioio; fli = ghiaie, sabbie e limi dell’immagine; flt = ghiaie, sabbie e limi del fiume turano. schematic reconstruction of the morpho-lithostratigraphic relationships between the different continental sedimentary units recognized in the carsoli basin (not in scale). lao = bosco di oricola silts, clays and sands; flg = madonna delle grazie gravels; bao = oricola scalo opening-vent breccias; tgo = oricola scalo grey tuffs; trg = s. giovanni red tuffs; flp = prati gravels, sands and silts; cfb = fonte bosco calcareous tufa; cof = fioio stream conglomerates; fli = immagine gravels, sands and silts; flt = turano river gravels, sands and silts fig. 4 limi, argille e sabbie del bosco di oricola (lao). sezione artificiale ubicata in prossimità della pendici del versante settentrionale di col farolo. i sedimenti, di origine lacustre, si presentano ben stratificati e inclinati di circa 20° verso sse. bosco di oricola silts, clays and sands (lao). artificial section located near the base of the col farolo northern slope. the lacustrine sediments are well stratified and inclined by about 20° to sse. evoluzione geomorfologica quaternaria ... nei livelli più argillosi, a luoghi, si individuano valve giovanili e frammenti di ostracodi di acqua dolce, appartenenti al genere ilyocypris e candona (gliozzi, comunicazione personale); si tratta di un’ostracofauna tipicamente ipoalina, propria di un ambiente lacustre o palustre, che non fornisce alcuna indicazione di età. sempre negli strati più argillosi si rinvengono gusci, in alcuni casi ben conservati, di gasteropodi, appartenenti ai generi cernuella cfr. virgata, cepea sp., helix sp., vallonia cfr. pulchella e dubitativamente limnea. tale malacofauna è costituita da tutte forme terrestri, se si esclude la presenza, peraltro dubbia, di limnea, genere tipico di acque stagnanti. i gasteropodi riconosciuti fanno presumere l’esistenza di un ambiente aperto, tipo prato, con bassa vegetazione. le malacofaune rinvenute, comunque, essendo banali, non consentono nessuna determinazione di età relativa. per quanto riguarda il contenuto pollinico della parte più argillosa di questi sedimenti, su tre campioni analizzati solo due hanno restituito rarissimi palinomorfi appartenenti a due soli taxa erbacei: artemisia e liliiflorae (sadori, 2005). un orizzonte lignitifero di modesto spessore è stato intercettato, ad una profondità di circa 100 m dal p.c., in un sondaggio realizzato molti anni fa all’interno del polverificio ex stacchini sud, in località rostere (quota boccapozzo 615 m s.l.m.). la frazione più sabbiosa è caratterizzata da una gran quantità di granuli di natura silicoclastica, mentre sono del tutto assenti livelli di origine piroclastica. le analisi diffrattometriche effettuate su alcuni campioni, infatti, hanno rilevato una composizione mineralogica costituita dai seguenti minerali, elencati in ordine di abbondanza: quarzo, plagioclasio, mica, clorite, caolinite e k-feldspato. la composizione mineralogica evidenziata, rivela una provenienza di questi depositi prevalentemente dall’erosione dei litotipi terrigeni messiniani, in gran parte affioranti nel settore settentrionale della conca di carsoli e a nord di essa, lungo la medio-alta valle del turano. lo spessore di questi depositi, secondo i dati provenienti da alcune perforazioni realizzate soprattutto per scopi idrici, ed in base ad indagini geofisiche appositamente effettuate dal servizio geologico nazionale (1998), è variabile da pochi metri lungo i margini della piana, a più di 200 m nella zona depocentrale del bacino, situata in corrispondenza del bosco di oricola. il limite inferiore di questa unità è rappresentato da una superficie di discontinuità erosiva, attraverso la quale la formazione poggia in discordanza angolare sul substrato marino carbonatico e terrigeno. tale superficie, tracciabile lungo il bordo settentrionale, nord-orientale e orientale della conca di carsoli, aumenta sensibilmente e progressivamente di quota da col farolo verso le propaggini dei rilievi simbruini (da 650 a 675 m circa) e dal convento di s. francesco verso ne (da 600 a 700 m circa). alla sommità l’unità è delimitata da un’antica ed estesa superficie suborizzontale, coincidente con l’attuale piano topografico e discordante con la giacitura degli strati. tale superficie, di natura chiaramente erosiva, è inclinata di circa 1° verso nord-ovest. di questa superficie allo stato attuale rimangono solo alcuni lembi relitti tra le quote 620 m (bosco di oricola) e 658 m s.l.m. (col farolo), in conseguenza della sua incisione da parte di un reticolo idrografico subdendritico orientato prevalentemente in direzione no-se e nne-sso. nel complesso la stratificazione nel settore centrale della conca è suborizzontale, mentre lungo il margine centro-orientale e nord-orientale della stessa gli strati assumono inclinazioni di circa 10°-20° con immersioni variabili da sso a se (fig. 4). in alcuni affioramenti, ubicati in prossimità di col farolo, sono state osservate delle piccole dislocazioni tettoniche di carattere distensivo con rigetto di qualche metro. la presenza, lungo il bordo orientale e nord-orientale della conca, di strati più inclinati e di piccole faglie, unita a una quota più elevata delle superfici di discontinuità che delimitano questa formazione, inducono ad ipotizzare un sollevamento di questo settore. i caratteri tessiturali e granulometrici di questi depositi, le loro strutture sedimentarie, la continuità laterale degli strati, la geometria e la regolarità delle superfici di stratificazione, l’ostracofauna in essi presente, fanno pensare ad una sedimentazione in un mezzo a bassa energia. pertanto, sulla base di queste caratteristiche, peraltro uniformi in tutto il bacino sedimentario, e della distribuzione areale dei sedimenti, i depositi in questione possono essere attribuiti, in accordo con vari autori (segre, 1953; demangeot, 1965; raffy, 1979; accordi et alii, 1986; detti, 1988; colica et alii, 1995; compagnoni et alii, 2005; d’orefice & graciotti, 2005; chiarini et alii, 2009), ad un ambiente deposizionale lacustre. in un affioramento situato nel bosco di oricola è stato individuato un livello di modesto spessore costituito da sabbie gialle grossolane, sovrapposte, con contatto erosivo, a questa formazione. le sabbie, di natura silicoclastica e prive di minerali femici, sono caratterizzate da piccoli canali d’erosione e da una stratificazione incrociata ad alto angolo, che indica una paleocorrente diretta verso i quadranti settentrionali. alla sommità dei depositi lacustri, nelle aree suborizzontali preservate dall’azione degli attuali processi erosivi, colica et alii (1995) hanno individuato dei paleosuoli (alfisuoli a profilo a b c) con caratteristiche pedologiche di condizioni climatiche non attuali. questi paleosuoli, secondo il parere degli stessi autori, dal confronto con altri paleosuoli dell’italia centrale, potrebbero essere attribuiti al pleistocene superiore. in mancanza di precisi riferimenti crono-biostratigrafici, le età proposte per i depositi lacustri sono generiche e diverse. secondo raffy (1981/82) tali sedimenti sono attribuibili al pleistocene medio; accordi et alii (1986) e compagnoni et alii (2005) li indicano come (?)plio-pleistocenici, mentre secondo detti (1988), colica et alii (1995) e d’orefice & graciotti (2005) essi hanno un’età compresa tra il pleistocene inferiore ed il pleistocene medio. questi depositi, in ogni modo, sono più antichi dei sovrastanti prodotti vulcanici, datati intorno ai 530-540.000 anni dal presente (cfr par. 5.3.). 5.2. ghiaie della madonna delle grazie (flg) questa formazione affiora, tra 640 m e 580 m di quota s.l.m., lungo il bordo nord-orientale della conca di carsoli, e più precisamente tra il convento di s. francesco ed il margine settentrionale della conca stessa (località “cerretine”). piccoli affioramenti, non cartografabili, probabilmente correlabili con quelli prima citati, si rinvengono, tra 700 e 710 m di quota, sulle colline 62 m. d’orefice et al. immediatamente a nord-ovest di carsoli, ed in particolare sul versante destro della valle mura, che si immette in destra della valle del turano. nel complesso la formazione in esame è costituita prevalentemente da ghiaie eterometriche, da centimetriche a decimetriche ed in misura minore da blocchi, che in casi eccezionali superano il metro di diametro (fig. 5). a luoghi nel deposito grossolano s’intercalano piccole lenti limoso-argillose o livelli sabbiosi. in generale il deposito ghiaioso si presenta mal classato. le ghiaie e i blocchi sono in prevalenza costituiti da litotipi calcarei appartenenti alla serie locale di piattaforma carbonatica, da “brecce della renga” ed in minor misura da litotipi arenacei. nella maggior parte dei casi i blocchi sono arrotondati, di forma sferica e con un indice di sfericità e di arrotondamento medio-alto; le ghiaie sono, invece, caratterizzate da una forma da sferica a discoidale e da un indice di arrotondamento minore. sporadicamente s’individuano clasti contraddistinti da un’alterazione superficiale. la matrice è abbondante, essenzialmente sabbioso-limosa e di natura silicoclastica. al suo interno non sono stati rinvenuti minerali femici di origine piroclastica. nel complesso la tessitura è a supporto di clasti e solo raramente è a supporto di matrice. non è evidente una netta embricatura dei ciottoli, comunque, nei pochi casi in cui questa è osservabile, essa denota un andamento prevalente della paleocorrente verso i quadranti settentrionali. questa formazione raggiunge uno spessore massimo di circa 10 m tra il convento di s. francesco e la collina calacorte. le ghiaie della madonna dele grazie sono inferiormente a contatto diretto, tramite una irregolare superficie d’erosione, sia con le torbiditi arenacee alto-mioceniche, sia con i limi, argille e sabbie del bosco di oricola (fig. 3). il limite superiore dell’unità coincide, invece, con l’attuale superficie topografica. dal punto di vista morfostratigrafico questa formazione, allungata nella stessa direzione dell’attuale corso del f. turano e sospesa sulla sua odierna piana alluvionale, costituisce un terrazzo deposizionale i cui elementi morfologici principali (superficie sommitale e scarpata) sono stati fortemente rimodellati dagli agenti esogeni. in base alle caratteristiche granulometriche e tessiturali, al grado di arrotondamento dei clasti, alla presenza, in alcuni casi, di embricatura dei ciottoli, questi depositi possono essere ascritti a facies torrentizie. l’attribuzione di un’età a questi sedimenti appare problematica. infatti, anche se la loro posizione altimetrica è comparabile con quella dei depositi alluvionali affioranti nel settore meridionale della conca, attribuiti al pleistocene medio finale (cfr. par. 5.4.), l’assenza di minerali di natura piroclastica nella matrice induce ad ipotizzare una loro messa in posto precedente al vulcanismo monogenico di carsoli ed a quello dei grandi centri peri-tirrenici. 5.3. vulcaniti della conca di carsoli nella parte centro-occidentale e meridionale della conca intermontana di carsoli, inizia bruscamente, a partire da un’articolata superficie erosiva modellata nei depositi lacustri e nel substrato carbonatico mesocenozoico, una peculiare sequenza di terreni vulcanici. si tratta di prodotti piroclastici di genesi locale, connessi alla presenza in quest’area di un vulcanismo monogenico medio-pleistocenico (barbieri et alii, 1997, 2000; società geologica italiana, 2003; d’orefice & graciotti, 2005; d’orefice et alii, 2006). le vulcaniti sono state datate con il metodo 40ar/39ar a 0,531 ma da bosi et alii (1991) e con il metodo rb/sr a 0,540 ma da d’orefice et alii (2006). la maggior parte dei prodotti vulcanici, e presumibilmente dei centri d’emissione, è localizzato nel settore centro-occidentale della conca, poco a nord di oricola, e nel settore meridionale, tra colle s. vito e camerata nuova e lungo il fosso rientro. un edificio isolato si trova nei pressi di col farolo, tra oricola e carsoli (fig. 2). gli affioramenti ubicati in sinistra del fosso fioio, tra gli abitati di rocca di botte e camerata nuova, si allineano con direzione nno-sse in corrispondenza della probabile prosecuzione, al di sotto della coltre continentale, della faglia normale d’interesse regionale del fosso fioio, a cui alcuni autori (devoto, 1967a; damiani, 1990; naso et alii, 1991; compagnoni et alii 1993) attribuiscono un’evoluzione tettonica complessa. nelle sequenze vulcaniche, costituite in prevalenza da tufi subaerei, non sono stati trovati paleosuoli né superfici erosive generalizzate imputabili a lunghe stasi eruttive (barbieri et alii, 2000). l’inclinazione degli strati è in genere poco accentuata, mentre sono frequenti le laminazioni incrociate e le strutture dunari, anche a scala metrica, associabili a surge. le varie facies deposizionali si presentano spesso con rapporti laterali eteropici o canalizzati. sono state riscontrate anche evidenti discordanze angolari e piccole faglie con rigetto da pochi centimetri ad alcuni decimetri, evidenti negli affioramenti di collina rostere e di oricola scalo (d’orefice & graciotti, 2005). la stratigrafia di dettaglio, ricostruita sulla base dei vari affioramenti presenti nel bosco di oricola e nell’area limitrofa all’autostrada roma-l’aquila a24, ha 63 fig. 5 ghiaie della madonna delle grazie (flg) affioranti nei pressi della località cerretine: ghiaie da centimetriche a decimetriche e blocchi a cui s’intercalano piccole lenti sabbiose. la porzione granulometricamente più fine del deposito è caratterizzata dall’assenza di minerali femici di natura piroclastica. madonna delle grazie gravels (flg) outcropping near cerretine: centimetric to decimetric gravels and blocks with intercalated sandy lenses. the finer components are characterized by the absence of mafic pyroclactic elements. evoluzione geomorfologica quaternaria ... permesso di riconoscere tre principali unità piroclastiche, che corrispondono ad altrettante fasi eruttive. quindi, all’interno di questa formazione sono stati distinti i seguenti membri, elencati dal basso verso l’alto (fig. 3 e 6): 1) brecce d’apertura di oricola scalo (bao); 2) tufi grigi di oricola scalo (tgo); 3) tufi rossi di s. giovanni (trg). dalle analisi chimiche, mineralogiche e petrografiche, concentrate sul membro dei tufi grigi di oricola scalo (tgo), poiché meno alterato degli altri, è emerso che la frazione juvenile di questi tufi è composta da lapilli non vescicolari plasticamente deformati e saldati tra loro, da lapilli altamente vescicolari (pomici), da frammenti vetrosi e da frammenti cristallini di leucite, flogopite, diopside e k-feldspato, spesso immersi in una matrice micritica (<1µm) e compatta di calcite. tra i minerali accessori sono presenti lo spinello magnetitico, l’apatite, il granato e l’olivina. la calcite micritica estratta dai lapilli è chimicamente molto diversa da quelle delle rocce sedimentarie e la sua composizione isotopica fornisce valori simili a quelli delle altre fasi mineralogiche e della roccia totale. inoltre, questi valori differiscono in modo significativo da quelli ottenuti sui carbonati sedimentari dell’area di oricola e sui clasti carbonatici incorporati nelle brecce d’apertura di oricola scalo (bao). in base alla composizione mineralogica ed alla moda generale, questi litotipi possono essere classificati come fono-foiditi e foiditi. quando il contenuto della matrice carbonatica di origine ignea è superiore o prossimo al 50% del volume totale della roccia, tali litotipi possono considerarsi carbonatitici o carbonatiti s.s. per una descrizione dettagliata delle caratteristiche minero-petrografiche e geochimiche delle unità piroclastiche individuate si rimanda, comunque, ai lavori specifici di barbieri et alii (2000), d’orefice & graciotti (2005) e d’orefice et alii (2006). di queste tre unità principali affiorano ampiamente solo le ultime due, mentre la prima, essendo legata alle fasi precoci d’apertura del condotto, affiora raramente. essa è stata incontrata soprattutto in alcuni sondaggi a carotaggio continuo appositamente eseguiti nell’area (servizio geologico nazionale, 2000); alcune osservazioni sono, tuttavia, possibili in blocchi, non in sito, provenienti da un vicino sbancamento effettuato nei pressi della stazione ferroviaria di oricola-pereto. le sequenze vulcaniche sopra citate a volte terminano con epiclastiti, costituite da lenti di sabbie ricche in cristalli, originate dal rimaneggiamento esogeno dei depositi primari. 5.3.1. brecce d’apertura di oricola scalo (bao) le brecce d’apertura di oricola scalo sono costituite da strati di spessore pluridecimetrico a struttura massiva che comprendono clasti calcarei d’origine sedimentaria, a spigoli vivi e di dimensioni centimetriche, immersi in una matrice cineritica grossolana (fig. 7). all’interno della matrice, inoltre, si rinvengono piccoli lapilli mediamente vescicolati, tra cui spiccano cristalli centimetrici di mica. tra i cristalli sono presenti anche pirosseno, leucite, k-feldspato e magnetite. gli strati sono a volte separati da intercalazioni di tufo a laminazione incrociata, riferibile a strutture tipo ripples, forse da ricondurre a fenomeni di base surge. questo membro risulta coerente per l’esistenza di cementi carbonatici. una parte dei clasti carbonatici d’origine sedimentaria è costituita da litotipi non affioranti nelle immediate vicinanze della conca di carsoli, ma che verosimilmente, provengono dal basamento attraversato dal condotto eruttivo, dato che i clasti carbonatici presenti nei depositi continentali circostanti, ed in posizione interna alla conca, non hanno caratteristiche compatibili con quelle delle brecce suddette. all’interno di quest’unità sono, inoltre, presenti vuoti, eventualmente riempiti da cementi secondari, lasciati da macrofossili vegetali e porzioni di fusti riferibili a graminacee (giardini m., comunicazione personale) completamente sostituiti da calcite. i macroresti vegetali mostrano che il materiale è stato inglobato violente64 fig. 6 colonna stratigrafica ricostruita sulla base dei vari affioramenti individuati nel bosco di oricola. si tratta di una complessa sequenza di prodotti da flusso piroclastico, surge e caduta (airfall) (parzialmente modificata da barbieri et alii, 2000). stratigraphic section of the various volcanic outcrops identified in the bosco di oricola, showing a complex sequence of pyroclastic flow, surge and airfall products (partially modified after barbieri et alii, 2000). m. d’orefice et al. mente, frammentato ed isorientato durante la messa in posto di questa prima unità eruttiva. gli strati di breccia sono stati interpretati per lo più come depositi molto prossimali da caduta (airfall) e/o da debris flow, relativi alla fase di apertura del condotto (barbieri et alii, 2000; d’orefice et alii, 2006). 5.3.2. tufi grigi di oricola scalo (tgo) i tufi grigi di oricola scalo sono costituiti da un insieme di facies variabili da straterelli di cinerite a laminazione pianoparallela o incrociata fino a strati massivi di cinerite (barbieri et alii, 2000) (fig. 8). questi ultimi sono saldati e molto competenti con accenni di jointing da contrazione ed evidente frattura concoide. lo spessore di questo membro, affiorante estesamente nel bosco di oricola, è mediamente intorno ai 2 metri, ma può raggiungere i 10 m circa presso l’area di servizio della a24 “civita nord”. l’affioramento più significativo è quello corrispondente alla colata piroclastica che si allunga in direzione e-o tra la collina rostere (quota 630 m s.l.m.) e la s. s. tiburtina valeria (quota 605 m s.l.m.), secondo una stretta fascia di circa 1,9 km di lunghezza (fig. 2). dalle evidenze di campagna e soprattutto dai sondaggi geognostici realizzati trasversalmente all’asse della colata (fig. 9), essa corrisponde ad un corpo canalizzato all’interno di una preesistente vallecola incisa nei depositi lacustri (lao). in conseguenza dell’inversione del rilievo ad opera dell’erosione selettiva, la colata piroclastica si trova attualmente lungo un displuvio, dove origina uno stretto ripiano tabulare. all’interno di questo membro sono stati individuati calchi di frammenti di legno, rami e foglie aghiformi di conifere, attribuibili prevalentemente a gimnosperme della famiglia delle pinaceae (generi abies, pinus e picea) (giardini & follieri, 1992) ed in subordine ad angiosperme (generi alnus, carya e zelkova) (giardini & sadori, in sadori, 2005). alcuni taxa come alnus, ma soprattutto abies e carya, richiedono condizioni clima65 fig. 7 brecce d’apertura di oricola scalo (bao): clasti calcarei spigolosi di natura sedimentaria, immersi in una matrice cineritica grossolana, da cui spiccano cristalli centimetrici di mica. nella matrice sono, inoltre, presenti frammenti di fusti vegetali completamente sostituiti da calcite. the oricola scalo opening-vent breccias (bao): sharp edged limestone sedimentary clasts immersed in a coarse cineritic matrix including centimetric crystals of mica and vegetal fragments completely substituted by calcite. fig. 8 tufi grigi di oricola scalo (tgo) affioranti all’interno del bosco di oricola. i tufi sono stratigraficamente sovrapposti ai depositi lacustri (lao) attraverso una superficie di erosione. the oricola scalo grey tuffs (tgo) outcropping at bosco di oricola. the tuffs stratigraphically overlay the lacustrine deposits (lao) by means of an erosion surface. fig. 9 sezione geologica a-a’, ricostruita per mezzo dei sondaggi meccanici effettuati nei pressi di oricola scalo in direzione trasversale all’asse della colata. geological section a-a' near oricola scalo. the section has been reconstructed by coreholes drilled transversely to the pyroclastic flow axis. evoluzione geomorfologica quaternaria ... tiche di tipo spiccatamente oceanico, caratterizzate cioè da una considerevole umidità atmosferica. i dati paleobotanici acquisiti sono perfettamente compatibili con le età attribuite a questi prodotti da bosi et alii (1991) e d’orefice et alii (2006). barbieri et alii (2000) e d’orefice et alii (2006) attribuiscono a questi depositi vulcanici una messa in posto, connessa, in prevalenza, a meccanismi di pyroclastic flow e di surge. 5.3.2. tufi rossi di s. giovanni (trg) i tufi rossi di s. giovanni sono costituiti da una fitta alternanza di strati cineritici grossolani e fini, con lapilli pomicei generalmente rotti e brecciati e localmente con gusci cineritici accrezionari. essi sono essenzialmente sovrapposti sia ai sottostanti tufi grigi (tgo), sia ai depositi lacustri precedentemente descritti (lao) (fig. 3). i tufi rossi hanno uno spessore (fino a 15 m) ed un’estensione areale di gran lunga maggiore di quella delle unità eruttive sottostanti. la giacitura varia da orizzontale ad inclinata (da 5° a 20°), rispecchiando la morfologia del substrato. in questa unità si notano appoggi in netta discordanza angolare, canali sindeposizionali, forme ammantanti e strutture dunari anche di dimensioni metriche (fig. 10) (barbieri et alii, 2000). i tufi non si presentano compatti ed inoltre sono frequentemente interessati da orizzonti con patine limonitiche e da un’intensa pedogenizzazione negli strati superiori. in base alle strutture sedimentarie e alle caratteristiche strutturali, questa unità è stata interpretata da barbieri et alii, 2000 come un’alternanza di depositi da surge e da caduta (airfall). la porzione superiore delle collinette che caratterizzano la zona compresa tra il bosco di oricola ed i contrafforti carbonatici meridionali è in gran parte costituita da questi materiali, i quali danno luogo a collinette, rimodellate dagli agenti esogeni, dalla forma conica, ellittica o semicircolare (fig. 2). 5.4. ghiaie, sabbie e limi dei prati (flp) a nord e ad est della piccola struttura carbonatica di colle s. vito, affiora un esteso corpo sedimentario rilevato di circa 15 – 20 m sulla piana alluvionale sottostante. la maggior parte del litosoma è compresa tra il fosso fioio-secco ed il fosso s. mauro (fig. 2). il limite inferiore di questo corpo sedimentario terrazzato è rappresentato da una superficie d’erosione fluviale irregolare, che lo pone a diretto contatto sia con il substrato carbonatico (nell’estremo settore meridionale della conca) e sia con i depositi lacustri e vulcanici (nel settore centro-meridionale della medesima depressione) (fig. 3). la mancanza di sezioni naturali e artificiali significative e di dati geognostici non ha consentito di delineare l’architettura interna di questa unità deposizionale. tuttavia, sulla base dei dati di campagna relativi alla distribuzione ed alla granulometria dei depositi affioranti in superficie, è possibile distinguere zone con prevalenza di sedimenti grossolani, alternate a zone essenzialmente caratterizzate da sedimenti fini. le prime sono contraddistinte principalmente da ghiaie grossolane e blocchi (diametro massimo intorno ai 30 cm) con tessitura a supporto di clasti e matrice sabbioso-limosa ricca in minerali vulcanici; i singoli elementi presentano un elevato indice di arrotondamento e sono costituiti da litotipi carbonatici di piattaforma (fig. 11). le seconde, più frequenti alla sommità del corpo sedimentario, sono invece rappresentate da limi sabbioso-argillosi e argille limose con abbondanti minerali di origine vulcanica. il corpo sedimentario presenta marcate variabilità di spessore, passando, in breve distanza, da spessori nulli a spessori intorno ai 20 m. il litosoma è delimitato superiormente da un’estesa superficie, corrispondente con il piano topografico, che si sviluppa più o meno tra le quote 700 e 620 m circa; tale superficie, coincidente con l’originaria superficie deposizionale, mostra un’inclinazione di circa un grado verso no. i depositi in questione sono alterati al tetto da 66 fig. 10 tufi rossi di s. giovanni (trg) affioranti tra l’a24 e la stazione ferroviaria di oricola-pereto, in corrispondenza di uno sbancamento antropico. i tufi sono caratterizzati da una fitta alternanza di cineriti grossolane e fini e da strutture dunari. the s. giovanni red tuffs (trg) outcropping between the a24 highway and the oricola-pereto railway station, next to a manmade cut. they are characterized by a tight alternance of coarse and fine cinerites showing dune structures. fig. 11 località “prati”: ghiaie eterometriche appartenenti alla facies grossolana dell’unità dei prati (flp). le ghiaie, ben arrotondate, sono costituite da litotipi carbonatici di piattaforma, mentre la matrice sabbioso-limosa è ricca di minerali vulcanici. le ghiaie sono sovrapposte all’unità dei tufi rossi di s. giovanni (trg). prati: heterometric gravels belonging to the coarse facies of the prati unit (flp). the well-rounded gravels consist of carbonate platform lithotypes, whereas the sandy-silty matrix is rich in volcanic minerals. the gravels rest on the s. giovanni red tuffs unit (trg). m. d’orefice et al. mollisuoli e alfisuoli sui depositi ghiaiosi e da entisuoli sui sedimenti più fini (colica et alii, 1995). il corpo sedimentario è dissecato dai diversi corsi d’acqua di provenienza simbruina, che si immettono nel settore meridionale della conca di carsoli. lembi isolati di modeste dimensioni, appartenenti a questa formazione, si rinvengono anche alla base del versante meridionale di col farolo, tra quota 610 e 625 m s.l.m., nei pressi della stazione di servizio della a24 (civita nord), tra quota 610 e 630 m s.l.m., e nei dintorni della collina rostere, intorno alla quota 615 m. in considerazione degli aspetti geometrici, tessiturali, e morfologici è possibile interpretare il corpo sedimentario in questione come la porzione più distale di un antico conoide di deiezione, che progressivamente sfumava, verso no, ad un ambiente di piana alluvionale. la deposizione del litosoma posteriormente ai prodotti del vulcanismo monogenico di carsoli, la posizione altimetrica della superficie sommitale relitta, il suo grado di evoluzione nei riguardi dei processi erosivi, nonché le caratteristiche pedogenetiche dei suoli su di essa sviluppatisi, fanno propendere per un’età del corpo sedimentario riferibile alla parte finale del pleistocene medio. 5.5. tufi calcarei di fonte bosco (cfb) i tufi calcarei di fonte bosco affiorano circa un chilometro a nord di colle s. vito, intorno alla quota di 635 m. essi costituiscono un corpo, leggermente inclinato verso oso, i cui resti danno luogo ad una forma planimetrica pressappoco triangolare, estesa in lunghezza per circa 250 m e larga al massimo circa 100 m (fig. 2). il corpo sedimentario, di spessore variabile tra 0,5 e 1,5 m circa, inferiormente poggia su una superficie erosiva modellata a spese sia dei depositi lacustri del bosco di oricola (lao) e sia della litofacies più grossolana delle ghiaie, sabbie e limi dei prati (flp), ad essi soprastante (fig. 3). il litosoma è delimitato superiormente da un suolo scuro evoluto da terreni ricchi in materiali vulcanici rimaneggiati, su cui si è sviluppato un rigoglioso castagneto (dramis et alii, 2008) (fig. 12). di un certo interesse è la presenza, nei dintorni del corpo sedimentario in esame, di concrezioni carbonatiche diagenetiche e di frammenti di vulcaniti grigie litoidi. il deposito carbonatico (65% di caco3) nel complesso si presenta grossolanamente stratificato in livelli coerenti. ad un’osservazione macroscopica il litotipo appare compatto, di colore marrone-giallognolo (10yr 6/4) e formato da fanghi di natura calcarea. internamente sono visibili ad occhio nudo alcuni gasteropodi polmonati di acque basse (lymnaea truncatula) e terrestri (genere euconulus) (esu d., comunicazione personale). tra le strutture post deposizionali, frequenti sono le mineralizzazioni di manganese, anche in forma dendritica, i cristalli e le vene di calcite orientate in modo casuale e le patine di color marrone scuro, anch’esse prive di un’orientazione prevalente. l’esame al microscopio polarizzatore di alcune sezioni sottili e le analisi diffrattometriche, hanno consentito d’individuare la seguente composizione mineralogica: 1) calcite micritica in percentuale predominante; 2) quarzo di apporto terrigeno, fillosilicati e mica (paragonite) in tracce. in base al contenuto mineralogico rilevato, il litotipo può essere classificato come calcare micritico. secondo dramis et alii (2008), il deposito carbonatico potrebbe essere classificato come freshwater travertine o calcareous tufa (pedley, 1990). una datazione isotopica, realizzata con il metodo dei disequilibri nella serie dell’uranio, eseguita sul deposito carbonatico, ha fornito una età di 46 ± 6 ka bp (dramis et alii, 2008). nella datazione si è tenuto in debito conto della presenza d’impurità applicando un metodo di correzione (total sample dissolution), che consiste nell’analizzare differenti sub-campioni dello stesso affioramento. questa datazione colloca il deposito carbonatico all’interno dello stadio isotopico mis 3, definito anche interstadio pleniglaciale (follieri et alii, 1989), essendo una fase di relativo riscaldamento tra il mis 4 (i pleniglaciale) e il mis 2 (ii pleniglaciale). il rapporto d’incassamento del deposito carbonatico con le ghiaie, sabbie e limi dei prati (flp), conferma, per quest’ultima formazione, un’età molto più antica dello stadio isotopico 3. 5.6. conglomerati del fosso fioio (cof) nel tratto di fondovalle che va dallo sbocco del fosso fioio nella conca di carsoli (poco prima di camerata nuova) alla località il casale (comune di rocca di botte), affiora una stretta fascia di depositi conglomeratici (fig. 2) che termina, in parte sotto forma di ghiaie sciolte, poco prima di colle s. vito. complessivamente il deposito è clasto-sostenuto; la matrice è solitamente assente, nei rari casi in cui è presente essa è costituita prevalentemente da sabbie ricche in minerali femici di natura vulcanica (fig. 13). i clasti, di origine carbonatica, litologicamente appartengono alla serie locale di piattaforma interna lazialeabruzzese. essi sono eterometrici (alcuni raggiungono il metro di diametro), di forma generalmente sferica e con grado di arrotondamento variabile da subangoloso a subarrotondato (litofacies gm di miall, 1977, 1978, 1985). nell’insieme il sedimento si presenta mal classato, non si osservano embricature nei clasti e canali d’erosione. 67 fig. 12 piccolo rilievo, ubicato circa 1 km a nord di colle s. vito, la cui parte sommitale è formata dai tufi calcarei di fonte bosco (cfb). questo deposito è ricoperto da un suolo scuro ricco di minerali vulcanici, sul quale si è sviluppato un boschetto di castagni. a small hill located ca. 1 km north of colle s. vito topped by the fonte bosco calcareous tufa (cfb). this deposit is covered by a brown soil rich in volcanic elements over which a small chestnut grove has grown. evoluzione geomorfologica quaternaria ... all’interno del deposito non si notano particolari strutture sedimentarie, tuttavia nel tratto compreso tra camerata nuova e rocca di botte si evidenzia una stratificazione grossolana pressoché orizzontale, sottolineata da un’alternanza di livelli formati da clasti a differente grado di arrotondamento. il cemento è calcitico e in alcuni casi riempie tutti i vuoti intergranulari. un tentativo di datare il cemento con il metodo u/th non ha dato buon esito, poiché l’elevata componente detritica in esso contenuta, non ha consentito di ottenere dei complessi isotopici puri da analizzare allo spettrometro. i rapporti stratigrafici di quest’unità con le ghiaie, sabbie e limi dei prati (flp) non sono osservabili per la mancanza di affioramenti significativi. sulla base delle sole caratteristiche geometriche e morfologiche, quali la posizione allo sbocco della valle, la forma leggermente svasata nella parte terminale e le quote delle superfici relitte sommitali (coincidenti con l’originaria superficie deposizionale) lievemente decrescenti verso il centro della conca, è possibile interpretare il corpo sedimentario in esame come parte di un ben 68 fig. 13 conglomerati del fosso fioio (cof) affioranti nei pressi di fontanile brecciaro: conglomerati costituiti da clasti carbonatici eterometrici da subangolosi a subarrondati. la matrice è scarsa o assente, mentre il grado di cementazione varia da basso a medio. fioio stream conglomerates (cof) outcropping near fontanile brecciaro: conglomerates made of heterometric, sub-angular to sub-rounded, carbonatic clasts, with scarce or absent matrix and low to medium cementation level. fig. 14 ghiaie, sabbie e limi dell’immagine (fli), messi in luce dall’erosione laterale del fosso cammarano, nei pressi del centro commerciale “carsoli 2”: ghiaie grossolane eterometriche di riempimento di canale fluviale, sormontate, con contatto netto, da sedimenti più fini di tracimazione fluviale. immagine gravels, sands and silts (fli), exposed by the lateral erosion of fosso cammarano near the carsoli 2 commercial center: heterometric coarse channel-fill gravels, overlain with sharp contact by finer overbank sediments. più esteso conoide alluvionale. probabilmente la messa in posto di tale conoide può essere avvenuta nel pleistocene superiore, in concomitanza dell’ultima glaciazione. 5.7. ghiaie, sabbie e limi dell’immagine (fli) le aree pianeggianti della conca di carsoli, altimetricamente disposte pressappoco tra le quote di 690 m (estremo settore meridionale della conca) e 585 m s.l.m. (estremo settore settentrionale), sono occupate da depositi di piana alluvionale non più attivi e sospesi da alcuni metri fino a circa 10 m sull’attuale fondovalle del fiume turano e del fosso cammarano (fig. 2). i depositi in questione sono costituiti da ghiaie grossolane eterometriche (prevalentemente centimetriche), da sub-arrotondate ad arrotondate, generalmente in matrice sabbiosa, passanti lateralmente e verticalmente, con contatto netto, a sabbie limose e limi argilloso-sabbiosi scuri (fig. 14). minerali femici di origine vulcanica si rinvengono sia nella matrice delle ghiaie, sia nella frazione sabbiosa dei sedimenti fini. si sottolinea che i clasti facenti parte delle facies più grossolane hanno un grado di arrotondamento ed una dimensione massima (intorno ai 20-25 cm) inferiore a quella dei clasti appartenenti ai depositi fluviali più antichi della conca di carsoli (flg e flp). i depositi ghiaiosi danno luogo a corpi sedimentari a geometria prevalentemente nastriforme, larghi alcune centinaia di metri e spessi anche qualche decina di metri. essi incidono, con contatto netto ed erosivo, i depositi più fini adiacenti, dando origine a canali di piana alluvionale. il limite inferiore è costituito da una superficie erosiva, che pone questo corpo sedimentario a diretto contatto sia con il substrato carbonatico (settore meridionale della depressione) e sia con le più antiche unità stratigrafiche continentali (lao, flg, tgo, trg, flp e cof). il limite superiore è rappresentato da una vasta superficie d’accumulo sub-orizzontale, coincidente con m. d’orefice et al. il piano topografico su cui corre la viabilità principale della conca (s.s. 5 tiburtina valeria, s.p. 27 del cavaliere, s.p. 48/b camerata nuova, via spineta). in superficie questi depositi sono caratterizzati da suoli abbastanza evoluti, che vanno da entisuoli a mollisuoli sui depositi più grossolani e da entisuoli ad alfisuoli sui sedimenti più fini (colica et alii, 1995). su alcuni livelli organici presenti all’interno di quest’unità stratigrafica sono state effettuate due datazioni al radiocarbonio, le quali hanno fornito le seguenti età calibrate: i) 4.180 – 3.940 anni cal bc (campione cedad-ltl3919a, prelevato alla sommità della formazione, lungo la sponda destra del fosso fioio, presso fontanile brecciaro – fig. 15); ii) 12.450 – 11.900 anni cal bc (campione cedad-ltl3920a, prelevato alla base della sponda sinistra del fosso fioio, presso fontanile brecciaro fig. 16). la gran parte dei conoidi inattivi ubicati in corrispondenza dello sbocco nella conca delle principali valli fluviali possono essere correlati a questi depositi, in quanto fisicamente in continuità morfologica con essi. in base alle considerazioni sopra esposte, e soprattutto alle datazioni radiometriche, si può ipotizzare per i depositi alluvionali, come anche per i conoidi inattivi, un periodo di formazione compreso tra il tardoglaciale e l’olocene antico. 5.8. ghiaie, sabbie e limi del fiume turano (flt) i sedimenti appartenenti a questa unità si rinvengono lungo i fondovalle attuali della conca e corrono incassati principalmente all’interno della formazione delle ghiaie, sabbie e limi dell’immagine (fli), terrazzandola, a sud-ovest di col farolo, a sud del convento di s. francesco e in località macerone, in almeno due ordini. si tratta di sedimenti prevalentemente limososabbiosi, affioranti lungo i fondovalle percorsi dal fosso carcarone, compreso il reticolo ad esso affluente, e dal fosso rientro. alternanze di strati ghiaiosi con strati limoso-sabbiosi e sabbioso-limosi si rinvengono, invece, lungo gli alvei dei fossi fioio, secco, s. mauro, pachetto e cammarano. tali alternanze sono ben evidenti anche lungo le sponde del fiume turano (fig. 17) e nelle aree ad esso adiacenti; tuttavia, a breve distanza dall’asse fluviale, affiorano in superficie depositi granulometricamente più fini, come ad esempio in destra del fosso carcarone (località pezze della mola), dove si 69 fig. 15 parte superiore dell’unità delle ghiaie, sabbie e limi dell’immagine (fli), affiorante lungo la sponda destra del fosso fioio, presso fontanile brecciaro. in evidenza sedimenti fini ricchi in materia organica, intercalati nei depositi ghiaiosi. la datazione al radiocarbonio di un campione prelevato in tale livello ha fornito l’età calibrata di 4.180 – 3.940 anni bc. upper part of the immagine gravels, sands and silts (fli), outcropping along the right bank of the fioio stream, near fontanile brecciaro. note the fine sediments, rich in organic matter, that are interbedded in the gravelly deposits. radiocarbon dating of a sample taken from this level provided a calibrated age of 4,180 to 3,940 years bc. fig. 16 parte inferiore dell’unità delle ghiaie, sabbie e limi dell’immagine (fli), affiorante lungo la sponda sinistra del fosso fioio, presso fontanile brecciaro. si notano sedimenti fini ricchi in materia organica, intercalati nei depositi ghiaiosi. la datazione al radiocarbonio di un campione prelevato in tale livello ha fornito l’età calibrata di 12.450 – 11.900 anni bc. lower portion of the immagine gravels, sands and silts (fli), outcropping along the left bank of the fioio stream, at fontanile brecciaro. note the fine sediments, rich in organic matter, that are interbedded in the gravelly deposits. radiocarbon dating of a sample taken from this level provided a calibrated age of 12,450 to 11,900 years bc. fig. 17 ghiaie, sabbie e limi (flt) affioranti lungo la sponda destra del fiume turano: ghiaie grossolane di riempimento di canale fluviale passanti superiormente, con contatto netto ed erosivo, a limi sabbiosi di tracimazione, finemente stratificati e ricchi di sostanza organica. gravels, sands and silts (flt) outcropping on the right side of the turano river: coarse channel-fill gravels passing upwards, with a sharp erosional contact, to finely stratified, overbank sandy silt sediments, rich in organic matter. evoluzione geomorfologica quaternaria ... passa ad una piana alluvionale costituita da limi argillosi e argille limose di tracimazione fluviale. in questa piana la continuità laterale dei depositi fini è a volte interrotta da sottili fasce (non cartografabili) di sedimenti più grossolani (in genere sabbie e ghiaie) dall’andamento in pianta arcuato, riconducibili a meandri abbandonati del f. turano. sempre in corrispondenza dell’attuale piana alluvionale del f. turano (località prata grande), le indagini geoelettriche hanno messo in evidenza l’esistenza di un paleocanale, a direzione circa est-ovest, leggermente spostato più a sud-ovest rispetto al corso d’acqua odierno. nella parte centrale dell’alveo del f. turano si possono osservare, in più punti, barre longitudinali in formazione costituite da ghiaie, passanti sottocorrente a sabbie grossolane. i suoli che a volte si osservano alla sommità di questa formazione sono caratterizzati da uno scarso grado di evoluzione pedogenetica (entisuoli, secondo colica et alii, 1995). una datazione al radiocarbonio effettuata su un legno carbonizzato rinvenuto all’interno di sedimenti limosi appartenenti a questa formazione (fig. 18) ha fornito un’età calibrata di 330 – 200 anni cal bc (cedadltl3921a), corrispondente al iv–ii sec. a.c. (età repubblicana di roma antica). il campione è stato prelevato alla base della sponda destra del f. turano, nei pressi della località macerone. ai depositi fluviali in esame si possono correlare alcuni conoidi di modeste dimensioni. tra questi possono essere citati quello di seconda generazione ad ovest di camerata nuova e quello del fosso luisa, ad est di camerata nuova. il rinvenimento di depositi databili all’interno di quest’ultimo conoide da parte di barbieri et alii (1998), è sicuramente d’indubbio significato, anche in considerazione del fatto che nell’area in esame sono quasi del tutto assenti i riferimenti cronologici relativi ai depositi quaternari continentali. il conoide del fosso luisa è ubicato 300 m ad est di camerata nuova (m.ti simbruini nord-orientali), in corrispondenza del tratto terminale dell’angusta valle a “v” percorsa dal fosso omonimo, affluente di sinistra del fosso fioio (fig. 2). in pianta il conoide ha una forma stretta ed allungata, con circa 200 m di larghezza massima e 1.200 m di lunghezza; la sua pendenza media si aggira intorno al 10% e lo spessore è superiore ai 5 m. in un taglio antropico è stato possibile individuare una successione che mostra le caratteristiche stratigrafiche e sedimentologiche della parte superiore del conoide. tale successione è costituita da (fig. 19): 1) uno strato inferiore di ghiaie calcaree eterometriche a spigoli smussati, con tessitura a supporto di matrice e gradazione inversa; 2) uno strato intermedio formato da sedimenti argilloso-limosi debolmente sabbiosi di colore 5yr3/4 (bruno rossastro scuro), contenenti piccoli frammenti di ceramica fluitata e con tracce di pedogenesi; 3) uno strato superiore di ghiaie e blocchi calcarei eterometrici, a spigoli smussati, con tessitura a supporto di clasti e gradazione inversa. la datazione con il metodo del 14c delle sostanze organiche presenti nello strato intermedio, interpretato come un deposito d’origine colluviale (barbieri et alii, 1998), ha fornito un’età radiometrica convenzionale di 3.270 ± 50 anni bp e un’età calibrata variabile tra 3.550 3.400 anni bp. in generale le carat70 fig. 18 depositi fluviali (flt) affioranti lungo la sponda destra del fiume turano: strato limoso contenente del materiale ligneo carbonizzato. la datazione al radiocarbonio di tale reperto ha fornito l’età calibrata di 330 – 200 anni bc. fluvial deposits (flt) outcropping on the right bank of the turano river: si lty layer containing carbonised wood. radiocarbon dating provided a calibrated age of 330 to 200 years bc. fig. 19 sezione schematica stratigrafica della parte superiore del corpo del conoide del fosso luisa (camerata nuova) (parzialmente modificata da barbieri et alii, 1998). legenda: 1) strato inferiore di ghiaie calcaree eterometriche con tessitura a supporto di matrice e gradazione inversa; 2) deposito colluviale a granulometria fine; 3) strato superiore di ghiaie e blocchi calcarei eterometrici, con tessitura a supporto di clasti e gradazione inversa. schematic stratigraphic section of the upper part of the luisa stream alluvial fan (camerata nuova) (partially modified after barbieri et alii, 1998). legend: 1) lower layer of heterometric calcareous gravels with matrix-supported texture and reverse grading; 2) fine-grained colluvial deposit; 3) upper layer of heterometric calcareous gravels and blocks, with clast-supported texture and reverse grading. m. d’orefice et al. teristiche sedimentologiche di entrambi gli strati ghiaiosi (basso grado di selezionamento, assenza di embricatura, gradazione inversa e la presenza di grossi massi alla sommità dell’affioramento) consentono d’ipotizzare un meccanismo di sedimentazione di tipo debris flow. 5.9. colluvi e detriti di versante (cdv) i depositi di natura colluviale si rinvengono al piede di aree interessate da processi di dilavamento, nel luogo in cui le condizioni morfometriche del versante consentono la loro deposizione. generalmente si tratta di sedimenti fini limoso-argillosi di spessore modesto (fino a circa 3 m), a struttura massiva, contenenti frequentemente ciottoli sparsi e frammenti di laterizi, che consentono di riferire la loro formazione almeno in parte all’olocene. questi depositi, distribuiti prevalentemente alla base dei rilievi, sono diffusi nelle aree di affioramento dei litotipi terrigeni e lacustri, ma si riscontrano anche in corrispondenza dei versanti carbonatici. i detriti di versante si rinvengono addossati ai piedi dei rilievi calcarei e calcareo-marnosi che bordano la conca di carsoli, dove danno luogo a fasce strette ed allungate. in particolare essi sono presenti alla base dei monti sabini orientali e ai piedi delle dorsali carbonatiche appartenenti ai m.ti simbruini nord-orientali, che racchiudono il settore meridionale della conca. i detriti di versante sono costituiti da clasti carbonatici sciolti, eterometrici, a spigoli vivi ed hanno una matrice terrosa. lo spessore massimo di questi depositi è dell’ordine di alcuni metri. 6. evoluzione geomorfologica dell’area i dati geologici, geomorfologici e geocronologici consentono di delineare, anche se in maniera incompleta e per certi versi incerta, una serie di eventi sedimentari ed erosivi che hanno caratterizzato quest’area. pertanto, viene qui di seguito riportata, in forma sintetica, la ricostruzione delle principali tappe evolutive che hanno interessato la conca in esame. dal messiniano al pliocene inferiore avviene il corrugamento generale della serie marina meso-cenozoica ad opera di fasi tettoniche compressive (cavinato et alii, 1986) e la sua definitiva emersione. a partire dal pliocene medio l’area viene interessata da una fase tettonica estensionale, caratterizzata da faglie dirette, che ribassano le strutture compressive (cavinato et alii, 1986). nel corso di questo periodo e sino al pliocene superiore avviene, secondo ambrosetti et alii (1987), un abbassamento dell’area, seguito da una risalita. nel pleistocene inferiore, in conseguenza di un nuovo abbassamento (ambrosetti et alii, 1987), verosimilmente si va progressivamente delineando una depressione, contraddistinta da un drenaggio centripeto, in cui inizialmente, con molta probabilità, si vanno a depositare, in analogia con altre conche intermontane, sedimenti di natura fluviale. si ritiene, infatti, che agli inizi del pleistocene il richiamo del drenaggio verso la conca di carsoli abbia consentito l’ingresso e la deposizione al suo interno di antichi sedimenti fluviali, prevalentemente grossolani, provenienti da nord e trasportati da un paleo-turano con verso di scorrimento opposto a quello attuale (chiarini et alii, 2009). questi depositi, non affioranti all’interno della conca, costituiscono un potente corpo alluvionale che improvvisamente termina in corrispondenza di turania. in seguito, lo stabilirsi di vere e proprie condizioni di endoreicità consentono la deposizione di una successione prevalentemente lacustre (limi, argille e sabbie del bosco di oricola – lao), costituita da alternanze di strati argilloso-limosi e sabbioso-limosi, il cui spessore è stato stimato intorno ai 200 m. verso la fine del pleistocene inferiore, in conseguenza del rapido e generalizzato sollevamento di tutto l’appennino centrale, si registra un forte incremento dell’erosione lineare, che produce un generale e veloce approfondimento delle incisioni vallive (dramis, 1992; d’agostino et alii, 2001). molto probabilmente, per effetto di questi eventi, come è avvenuto per altre depressioni tettoniche dell’appennino centrale (centamore et alii, 2006), la conca di carsoli viene raggiunta dall’erosione regressiva che, dopo avere aperto una soglia nel suo settore settentrionale, ha causato lo svuotamento del lago e la conseguente interruzione della sedimentazione lacustre. l’apertura di tale soglia porta allo sviluppo di una rete idrografica drenante verso nord ed alla deposizione, al di sopra dei depositi lacustri, di modesti spessori di sabbie fluviali, caratterizzate da strutture trattive che indicano una paleocorrente diretta verso i quadranti settentrionali. successivamente s’instaura un’intensa fase di erosione, che porta alla parziale asportazione dei depositi di chiusura del bacino lacustre. si origina, in questo modo, una vasta superficie di erosione blandamente inclinata verso i quadranti settentrionali. in seguito, lungo il margine settentrionale della conca di carsoli, s’imposta un corso d’acqua con direzione simile a quello dell’attuale f. turano, che dà luogo ai deposti grossolani in facies torrentizia, affioranti tra il convento di s. francesco e la località cerretine (ghiaie della madonna delle grazie – flg). movimenti differenziali, legati sempre a tettonica estensionale, probabilmente causano, lungo il margine orientale e nord-orientale della conca, il progressivo basculamento dei depositi lacustri, la loro fagliazione e l’individuazione di lembi sollevati a differenti quote. nel pleistocene medio (530-540.000 anni bp), dopo una fase erosiva di tipo lineare, nel settore centrooccidentale e meridionale della conca, ha inizio un’attività vulcanica monogenica, con una serie di centri di emissione allineati lungo la probabile prosecuzione, al di sotto della coltre continentale, della faglia normale d’importanza regionale del fosso fioio. l’attività, prevalentemente subaerea, ha dato origine prima a brecce eterogenee legate alle fasi precoci d’apertura del condotto (brecce d’apertura di oricola scalo – bao), poi a depositi da surge e da colata piroclastica (tufi grigi di oricola scalo tgo) ed infine a depositi da surge e caduta (tufi rossi di s. giovanni trg). l’assenza di paleosuoli o di estese superfici erosive post-deposizionali nelle sequenze vulcaniche individuate, sta a indicare che tra un evento deposizionale e l’altro non si sono verificate lunghe stasi eruttive. la presenza all’interno dei tufi grigi di oricola scalo di calchi di macroresti vegetali, attribuibili prevalentemente a gimnosperme della famiglia delle pinacee ed 71evoluzione geomorfologica quaternaria ... in subordine ad angiosperme, conferma un’attività vulcanica avvenuta principalmente in ambiente deposizionale subaereo. inoltre, alcuni taxa arborei (alnus, abies e carya) sono indicativi di condizioni di spiccata oceanicità (giardini & sadori, in sadori, 2005) e pertanto di un contesto paleoclimatico diverso da quello attuale. successivamente alla messa in posto delle vulcaniti ed al loro rimodellamento da parte del processo fluvio-denudazionale, nel pleistocene medio finale si assiste alla deposizione di sedimenti verosimilmente di transizione tra facies di conoide e di piana alluvionale (ghiaie, sabbie e limi dei prati flp) che, nel settore meridionale della conca, vanno a costituire un esteso corpo sedimentario di spessore massimo decametrico. alla fase di aggradazione fluviale segue, nel pleistocene superiore, una fase erosiva di tipo lineare che ha portato alla dissezione del corpo alluvionale in precedenza formatosi. nel corso dell’ultima glaciazione si ha la costituzione, sui rilievi più elevati dei m.ti simbruini, di estesi apparati glaciali. essi interessano anche la testata del fosso fioio che si trova molto più a sud dell’area in esame. l’abbondanza di apporti solidi, trasportati a valle dalle acque di fusione glaciale, determina la formazione del conoide fluviale del fosso fioio (conglomerati del fosso fioio – cof), costituito da conglomerati clasto-sostenuti prevalentemente massivi. durante un periodo di riscaldamento tra due pleniglaciali (stadi isotopici 4 e 2), e più precisamente intorno ai 46.000 ± 6.000 anni bp (datazione u/th – dramis et alii, 2008), è avvenuta la deposizione dei tufi calcarei di fonte bosco (cfb), affioranti un chilometro a nord di colle s. vito. questa datazione colloca, quindi, il deposito studiato all’interno dello stadio isotopico mis 3, definito anche interstadio pleniglaciale. nel corso di tale stadio le condizioni climatiche sono caratterizzate da un parziale aumento della temperatura e dell’umidità, come testimoniato dalle serie polliniche studiate in aree vicine, in particolare quelle della sequenza della valle di castiglione (follieri et alii, 1989), distante dalla conca circa 30 km. nel corso dell’interstadio pleniglaciale, nella sequenza di valle castiglione non si registra una vera e propria fase a foresta, ma la presenza di querce e faggi testimoniano l’esistenza di una piccola espansione del bosco. la datazione isotopica di questo deposito carbonatico conferma l’età più antica (pleistocene medio finale) delle ghiaie, sabbie e limi dei prati (flp) in cui esso è incassato. alla fine del tardoglaciale, una fase erosiva di tipo lineare interessa il conoide fluviale del fosso fioio e tutti i sedimenti in precedenza deposti. nel corso di tale fase avviene anche il modellamento dei tufi calcarei di fonte bosco (cfb). tra la fine del tardoglaciale e l’olocene antico, nell’area dell’immagine, si registra la messa in posto di sedimenti di piana alluvionale (ghiaie, sabbie e limi dell’immagine – fli), costituiti da depositi grossolani di canale, a geometria nastriforme, che tagliano, con contatto netto ed erosivo, i depositi più fini adiacenti. una successiva fase erosiva ha inciso tali depositi, i quali attualmente sono sospesi sul fondovalle del fiume turano e del fosso cammarano, attraverso almeno due ordini di terrazzo. nel tardo-olocene avviene la deposizione della porzione superiore del conoide del fosso luisa (a est di camerata nuova), il cui studio (barbieri et alii, 1998) ha consentito di delineare i seguenti eventi sedimentari: 1) deposizione, secondo meccanismi gravitativi di tipo debris flow, di uno strato inferiore di ghiaie calcaree, in un momento più antico di 3.550 3.400 anni cal bp; 2 messa in posto di depositi colluviali in un momento successivo a 3.550 3.400 anni cal bp; 3) deposizione, tramite meccanismi di tipo debris flow, di uno strato superiore di ghiaie e blocchi calcarei, in un momento molto più recente di 3.550 3.400 anni cal bp. i due episodi di sedimentazione grossolana potrebbero essere attribuiti alla diminuzione della copertura boschiva, imputabile ad una tendenza, in un contesto climatico olocenico per lo più temperato umido, verso periodi più secchi o caratterizzati da precipitazioni irregolari di forte intensità (frezzotti & giraudi, 1989; 1992). l’episodio molto più recente di 3.550 3.400 anni dal presente potrebbe anche essere attribuito al disboscamento connesso all’attività antropica. sempre nel tardo-olocene, nei fondovalle dei fossi ritorto, carcarone e rientro sedimentano terreni prevalentemente fini, mentre lungo gli alvei dei fossi fioio, secco, s. mauro, pachetto e cammarano e del fiume turano, avviene la deposizione di alternanze di strati sabbioso-limosi e limoso-sabbiosi con strati ghiaiosi (ghiaie, sabbie e limi del fiume turano – flt). attualmente si assiste ad una fase di incisione dei depositi fluviali recenti, con conseguente approfondimento del reticolo idrografico. questa fase erosiva ha messo a giorno i sedimenti lacustri (lao) lungo gli alvei dei fossi secco, di fonte bosco e cammarano e in corrispondenza di quello del f. turano. ringraziamenti gli autori ringraziano i due revisori anonimi per i preziosi suggerimenti forniti e i dottori mauro roma e valerio vitale per l’elaborazione grafica delle figure. bibliografia accordi g., carbone f., civitelli g., corda l., de rita d., esu d., funiciello r., kotsakis t., mariotti g. & sposato a. (1986) lithofacies map of latiumabruzzi and neighbouring areas. c.n.r. quaderni della ricerca scientifica, 114 (5), pp. 223, roma. ambrosetti p., bosi c., carraro n., ciaranfi n., papani g., vezzani l. & zanferrari a. (1987) neotettonic map of italy. progetto finalizzato geodinamica. c.n.r., quaderni della ricerca scientifica, 4. apat – servizio geologico d’italia (2009) f. 367 “tagliacozzo” della carta geomorfologica d’italia alla scala 1:50.000. barbieri m., barbieri m., castorina f., d’orefice m., giardini g., graciotti r. & trudu c. (1997) le vulcaniti del bosco di oricola (l’aquila): caratteristiche geolitologiche, petrostrutturali ed isotopi72 m. d’orefice et al. che. min. petr. acta, 39, pp.125-133, bologna. barbieri m., d’orefice m. & graciotti r. (1998) datazione radiometrica di un deposito colluviale in un conoide situato nel settore meridionale della piana del cavaliere (appennino laziale-abruzzese). geogr. fis. dinam. quat., 21 (2), pp. 267-269, torino. barbieri m., barbieri m., d’orefice m., graciotti r. & stoppa f. (2000) il vulcanismo monogenico medio-pleistocenico della conca di carsoli (l’aquila). geologica romana, 36, pp. 13-31. bieler-chatelan t. (1928) gli antichi ghiacciai pleistocenici dei monti simbruini (appennino centrale). boll. soc. geol. d’it., 47 (1), pp. 33-45. bieler-chatelan t. (1929) nuove osservazioni sulle traccie glaciali dei monti simbruini (appennino centrale). boll. soc.geol. d’it., 48 (1), pp. 163175. bieler-chatelan t. (1930) le glacièr polysyntetique quaternaire des monti simbruini (appennin central): note i – les limites de son extension. c.r. acad. des sciences, 385-388; note ii – le causes de son extension. c.r. acad. des sciences, pp. 438-440. bieler-chatelan t. (1931) una presunta prova di trasporto glaciale nella valle di arsoli (lazio). boll. soc. geol. it., 50. bosi c., locardi e. & villa i. m. (1991) il distretto magmatico abruzzese. atti workshop simp, pisa 1213 giugno 1991, pp. 68-69. bosi c. & locardi e. (1991/2) vulcanismo meso-pleistocenico nell'appennino laziale-abruzzese. studi geol. camerti, vol. spec. (1991/2), crop 11, pp. 319-325. castellarin a., colacicchi r., praturlon a. & cantelli c. (1982) the jurassic-lower pliocene history of the ancona-anzio line (central italy). mem. soc. geol. it., 21, pp. 325-336. cavinato g.p., salvini f. & tozzi m. (1986) evoluzione strutturale del settore centrale della linea olevanoantrodoco. mem. soc. geol. it., 35 (1986), pp. 591-601. centamore e., crescenti u. & dramis f. (2006) note illustrative della carta geologica d’italia alla scala 1:50.000, foglio 369 “sulmona”. apat, regione abruzzo, 154 pp. chiarini e., d’orefice m., graciotti r., la posta e. & papasodaro f. (2009) note illustrative della carta geomorfologica d’italia alla scala 1:50.000. foglio 367 “tagliacozzo”. apat – servizio geologico d’italia, 200 pp. cipollari p. & cosentino d. (1992) la linea olevanoantrodoco: contributo della biostratigrafia alla sua caratterizzazione cinematica. studi geol. camerti, vol. spec. (1991/2) crop 11, pp. 143-149, camerino. colica a., lorenzoni p., magaldi d. & raglione m. (1995) geologia del quaternario e lineazioni nella conca tettonica tra oricola e carsoli in provincia dell'aquila. boll. serv. geol. d'it., 112, pp. 49-58, roma. compagnoni b., galluzzo f., giovagnoli m.c., lembo p., molinari v., pampaloni m.l., pichezzi r.m., rossi m., salvati l., santantonio m., raffi i. & chiocchini u. (2005) note illustrative del foglio 367 “tagliacozzo”. servizio geologico d’italia, pp. 83, roma. compagnoni, b., galluzzo f. & santantonio m. (1993) osservazioni sulla tettonica e dati sulla litostratigrafia dei rilievi carbonatici compresi nel foglio 367, “tagliacozzo” scala 1:50.000. boll. serv. geol. d’it., 109 (1990), pp. 73-90, roma. cosentino d. & parotto m. (1991) la struttura a falde della sabina (appennino centrale). studi geol. camerti, vol. spec. (1991/2) crop 11, pp. 381387, camerino. d’agostino n., dramis f., funiciello r. & jackson j.a. (2001) interactions between mantle upwelling, drainage evolution and active normal faulting: an example from the central apennines (italy). geophysical journal international, 147, pp. 475497. damiani a.v. (1984) considerazioni sulla evoluzione geodinamica della l inea tettonica “anticoli corrado-olevano romano” e delle zone ad esse adiacenti (lazio). boll. serv. geol. d’it., 103 (1982), pp. 177-240. damiani a.v. (1990) studi sulla piattaforma carbonatica laziale-abruzzese. nota i. considerazioni e problematiche sull’assetto tettonico e sulla paleogeologia dei monti simbruini. mem. descr. carta geol. it., 3, pp. 145-176. demangeot j. (1965) géomorphologie des abruzzes adriatiques . centre de recherches et documentation cartographiques et géografiques. mémoires et documents, numero hors série, 403 pp., paris. detti g. (1988) evoluzione geologica pliopleistocenica della piana del cavaliere (l'aquila). tesi di laurea inedita, università degli studi di roma “la sapienza”, relatore girotti o., correlatore sposato a., 158 pp. devoto g. (1967a) note geologiche sul settore centrale dei monti simbruini ed ernici (lazio nord-orientale). boll. soc. nat. in napoli, 76, pp. 1-112. devoto g. (1967b) le brecce calcaree mioceniche nell’alta valle roveto, tra castellafiume e canistro (frosinone, lazio meridionale). geol. romana, 6, pp. 75-86. di filippo m. & toro b. (1979) primi dati sul rilevamento gravimetrico dei monti simbruini. rend. soc. geol. it., 2, pp. 47-50. d’orefice m. & graciotti r. (2005) geological and geomorphological aspects of the central-western area of the carsoli basin (l’aquila, italy). geogr. fis. dinam. quat., 28, pp. 181-191. d’orefice m., graciotti r., capitanio f., stoppa f., rosatelli g. & barbieri m. (2006) il vulcanismo medio-pleistocenico dell’appennino lazialeabruzzese: dalle peculiarità scientifiche agli aspetti applicativi. mem. descr. carta geologica d’italia, 72, pp. 66, roma. dramis f. (1992) il ruolo dei sollevamenti tettonici a largo raggio nella genesi del rilievo appenninico. studi geol. camerti, vol. spec. (1991/2) crop 11, pp. 9-15, camerino. dramis f., soligo m., graciotti e., d’orefice m. & graciotti r. (2008) u/th dating of a tufa deposit from the carsoli intramontane basin (abruzzo, italy). geogr. fis. dinam. quat., 31, pp. 255-258. 73evoluzione geomorfologica quaternaria ... follieri m., magri d. & sadori c. (1989) pollen stratigraphical synthctsis from valle di castiglione (roma). quat. int., 3, pp. 81-84. frezzotti m. & giraudi c. (1989) evoluzione geologica tardo-pleistocenica ed olocenica del piano di aremogna (roccaraso, abruzzo): implicazioni climatiche e tettoniche. mem. soc. geol. it., 42, pp. 5-19. frezzotti m. & giraudi c. (1992) evoluzione geologica tardo-pleistocenica ed olocenica del conoide complesso di valle majelama (massicio del velino, abruzzo). il quaternario, 5 (1), pp. 33-50, verona. giardini m. & follieri m. (1992) dati preliminari su resti vegetali calcarizzati provenienti da carsoli (italia centrale). giornale botanico italiano, 126 (2), p. 416. gortani m. (1930a) sul limite pleistocenico delle nevi nell’italia centrale. rend. r. acc. sc. ist. bologna, pp. 3-8. gortani m. (1930b) sui ghiacciai quaternari dell’italia centrale. atti xi congr. geogr. it. (napoli), pp. 111. gortani m. (1931) sulla glaciazione quaternaria nell’appennino abruzzese. rend. r. acc. sc. ist. bologna, n.s., 35, pp. 34-39. lorenzoni p., magaldi d. & raglione m. (1995) carta dei suoli della conca intramontana tra oricola e carsoli (provincia dell’aquila). s.e.l.c.a. – firenze. miall a. d. (1977) a review of braided river depositional environment. earth sci. reviews, 13: pp. 1-62. miall a. d. (1978) lithofacies types and vertical models in braided river deposits: a summery. in: fluvial sedimentology (miall a.d. editor). mem. can. soc. petrol. geol., 5: 597-604. miall a. d. (1985) architectural-element analysis: a new method of facies analysis applied to fluvial deposits. earth sci. reviews, 22, pp. 261-308. naso g., pialli g. & tallini m. (1991) un transetto geologico nei monti simbruini (appennino centrale): implicazioni strutturali profonde. workshop crop 11 appennino centrale (civitavecchiavasto). roma, pp. 94-95 (abstract). pedley h.m. (1990) classification and environmental models of cool freshwater tufas. sedimentary geology, 68, 143–154. raffy j. (1979) le versant tyrrhénien de l’apennin central: étude géomorphologique. thése inédite, 705 pp. raffy j. (1981/82) orogenèse et dislocations quaternaires du versant tyrrhènien des abruzzes (italie centrale). revue de geologie dynamique et de gèographie physique, 23 (1), pp. 55-72, paris. regio ufficio geologico (1934) f° 145 “avezzano” della carta geologica d’italia alla scala 1:100.000. sadori l. (2005) studio paleobotanico dei depositi continentali plio-quaternari affioranti nell’area del foglio 367 “tagliacozzo” della carta geomorfologica d’italia in scala 1:50.000. rapporto inedito. segre a. g. (1953) aperçu morphologique et géologique de l’apennin entre rome et aquila. inqua, rome-pise, livret-guide excursion abruzzespouilles-salerne. servizio geologico nazionale (1998) indagini geofisiche nella piana del cavaliere. rapporto interno inedito. servizio geologico nazionale (1999) indagini geoelettriche nei piani palentini (aq) ed in altre aree del foglio geomorfologico “tagliacozzo”. rapporto interno inedito. servizio geologico nazionale (2000) indagine geognostica a scopo scientifico nell’ambito del foglio geomorfologico n° 367 “tagliacozzo”. rapporto interno inedito. servizio geologico d’italia (2005) carta geologica d’italia alla scala 1:50.000. f. 367 “tagliacozzo”. società geologica italiana (2003) itinerario n° 7 da carsòli alla valle del fiume salto. guide geologiche regionali – abruzzo, 10, pp. 1 337. be-ma ed. suter k. (1934) die eiszeitliche vergletscherung der apennine, 3, monti simbruini. zeitschr. für gletscherk, 21, pp. 342-353. suter k. (1939) die eiszeitliche vergletscherung der zentralapennins. beiblatt zur vierteljahrsschrift, 84 (31), 140 pp. 74 ms. ricevuto il 23 novembre 2009 testo definitivo ricevuto il 19 aprile 2010 ms. received: november 23, 2009 final text received: april 19, 2010 m. d’orefice et al. imp.gregori&melelli geotourism & geomorphosites: the g.i.s. solution lucilia gregori & laura melelli dipartimento di scienze della terra, università degli studi di perugia, piazza università 06123 perugia 1lucilia@unipg.it, 2lmelelli@unipg.it abstract: l. gregori & l. melelli, geotourism & geomorphosites: the g.i.s. solution. (it issn 0394-3356, 2005). geomorphologic research which has the geographical area of umbria and the neighbouring territories as a subject of study, sheds light on some features possessing a relevant cultural and scientific value, known in literature as “geomorphosites”. nowadays geotourism is an excellent opportunity to exploit the scientific knowledge researchers have of geomorphosites as a source of didactical and economical value. the idea is to enhance the tourist attention towards geomorphosites, through the use of more traditional and better known interests. having this aim in mind, a more careful research was made for each geomorphosite. different characteristics are reported as: oenogastronomic tours, historic-artistic values, and craftsmanship activities. g.i.s. are the best instruments to manage and analyze geomorphologic data. in particular geomorphosites, which are mapped and spatially georeferenced have a geographical characterization so that they can be best studied through the use of g.i.s. in g.i.s. different functions are available as querying maps, or building relations in relational database (one to one or many to one) in order to obtain detailed tourist itineraries. riassunto: l. gregori & l. melelli, geoturismo e geomorfositi: una soluzione in ambiente gis. (it issn 0394-3356, 2005). da alcuni anni, lo studio delle caratteristiche geomorfologiche del territorio, ha messo in evidenza in umbria e nelle aree limitrofe, (analogamente al lavoro svolto in italia e all’estero) la presenza di forme con alto valore scientifico e culturale, definite “geomorfositi”. un nuovo approccio alla conoscenza e alla promozione di questi siti è costituito dal loro inserimento in nuove nicchie turistiche. nasce così il “geoturismo” ovvero un turismo che privilegia, lungo i consueti circuiti, mete con alto valore scientifico, geologico e geomorfologico, consentendone il passaggio da un ambito strettamente accademico ad uno gestionale economico. nonostante il più alto livello culturale del turista medio, i geomorfositi rimangono ancora un campo poco o nulla esplorato dagli attuali flussi turistici. trovare nuovi modi per far avvicinare il turista ai geomorfositi, passando attraverso interessi più tradizionali e già testati, è lo scopo principale del presente lavoro. i sistemi informativi geografici (g.i.s.), intesi come nuovi strumenti per la gestione e l’analisi di dati geografici, rappresentano un utile mezzo per il management dei beni geomorfologici e per la loro diffusione in ambito turistico. gli aspetti più “tradizionali”, che costituiscono un valore aggiunto al bene geologico-ambientale, oltre a quelli di carattere strettamente scientifico, sono implementati nel database relazionale del progetto: gli elementi geologico-geomorfologici, le valenze storico/artistiche, culturali s.l., l’artigianato e le tradizioni popolari, il valore paesaggistico/ambientale, la progettazione di percorsi escursionistici ecc. il carattere territoriale dei geomorfositi (forme presenti nello spazio geografico, georeferenziabili e cartografabili), collegato ad un certo numero di attributi, li rende gli oggetti ideali per essere gestiti dai sistemi g.i.s. utilizzando le potenzialità di tali sistemi (connessioni tra tabelle con relazioni uno a uno e molti a uno e/o formulazione di query) è possibile interrogare il database per ottenere la selezione dei geomorfositi che rispondono alle specifiche esigenze turistiche. la proprietà geografica del dato (georeferenziazione) permette inoltre, una volta avvenuta la selezione, di creare percorsi di collegamento tra i siti, che ne tengano in considerazione ulteriori caratteristiche come la fruibilità o l’accessibilità keywords: geographical information system (g.i.s.), geomorphosite, geoturism. parole chiave: sistemi informativi geografici (g.i.s.), geomorfositi, geoturismo. il quaternario italian journal of quaternary sciences 18(1), 2005 volume speciale, 285-292 1. introduction new research perspectives in geological and geomorphologic disciplines have led to define and evaluate forms, known in literature as geomorphosites. they possess a relevant scientific, cultural and socio-economic value, (brancucci & burlando, 2000; panizza & piacente, 2002a; panizza & piacente, 2002b; panizza, 1992; poli, 1999). nowadays the research of specific methods to define these sites is one of the main aims in national and international literature (d’andrea & di legino, 2003; wimbledon, 1996). in addition the application of geographic information system (g.i.s.) has a not well-defined role yet. in many cases the g.i.s. systems can elaborate an interactive and real-timeupdatable cartography (carton et al., 2003). also some attempts have been carried on to use g.i.s. as an analytical way to fix up a methodology for weighing different attributes of the geomorphosites. at this purpose we can obtain a model to distinguish many forms on the territory (giusti & gonzalez-diez, 2000). still we can find some difficulties in transferring themes of geomorphosites from a strictly academic sphere to a one more accessible and useful for the community. particularly, these themes can integrate with anthropic tissue, which they belong to. therefore, to include geomorphosites in articulate and studied tourist-didactic routes seems to be a scientific and tourist relevant purpose (massoli-novelli, 2003). the use of g.i.s., more than every other traditional cartographical instrument, enables to manage different attributes of geomorphosites and gives back a real-time updatable, interactive and extremely flexible data. one of the main difficulties, linked to the diffusion 286 l. gregori & l. melelli of geomorphosites in tourist circuits, is their sectorial nature. until know, the interest in this subject was restricted only to geologists, naturalists, geographers, and not extended to common people. the implementation of databases inside gis projects takes into account the necessity of turning a bigger number of visitors towards geotourist routes. therefore, what can be done is to determine and study geomorphosites along well known tourist routes. the central core of db consists of a census and subsequent evaluation of existing additional values near a geomorphosite, like museums, naturalistic paths, historic centres with festivals and popular traditions. in the paragraph dedicated to db structure, these additional values will be described in detail. 2. geomorphosites in umbria several sites of relevant geological-geomorphologic aspects can be marked in umbria (fig. 1): in certain cases these had an influence onto the historic and cultural local evolution of the territory (like for assisi, trasimeno lake, “mesa” of orvieto, mounts sibillini area, marmore falls and others). nowadays they conjugate environmental realities and territorial intrinsic bents, potential and expressed for a synthetic vision of all possible scientific and cultural aspects, constituting an important resource and/or wealth of our territory. determination and census of geomorphosites in umbria and in neighbouring areas have led to the identification of nineteen sites, some of which have been exclusively selected for their geomorphologic characteristics. others have been chosen for the peculiarity of the related cultural and historical characteristics. the “intermountain basins” phenomenon are an interesting example of geomorphosites in central apennines and particularly in the umbrian one. they are wide depressed areas linked to extending plio-pleistocenic tectonics, characterizing western slopes of apennine structures. in “gubbio basin”, the depressed area of “gualdo tadino”, “colfiorito plains” and “pian grande” there are morphologic evidences of tectonic activity (triangular facets) and of karst morphogenesis (polije). these areas gain an important morphological role, because they are identified as tectonics depressions linked to apennines evolution. moreover they constitute a particularly charming landscape which can be considered different seasons as a tourist point of interest, also within a gastronomic, sports-tourist approach. umbrian apennine, in virtue of a massive calcareous formation, presents picturesque landscapes and characteristic phenomena of karst morphogenesis, both hypogean and epigean, and in macro and microforms. karst polijes show several animal species and endemic vegetable associations. even brachy-anticline of mount subasio with “mortari” (depressions with doline shape set along the top of the mountain) are particularly interesting for form and dimension and have an evident scenic value. climatic conditions inside mortari also allow the existence of phytosociologic associations. among hypogean karst morphotypes the complex of mount cucco caves represents the broadest system of central italy, while the hypogean cavities of mount maggiore abbey, developed on the inside limestone “horizons”, intercalated with a flysch sequence, fig. 1 location map. localizzazione dell’area di studio. involve less known but very interesting sites, from a genetic and evolutive point of view and scientifically attention worthy as well. in umbria morphogenetic fluvial agent is responsible for peculiar forms as rio freddo gorge and for the carving of gorghe (fig. 2), where lithoselection phenomena permit overhang of fault gravel creating something like a “range reversal”. these sites can be joined up in a speleological route as well as they allow an epigean hiking both along rio freddo “potholes” and gorghe “wall”, where the study of geomorphologic phenomena and sport activities combine extremely well. in both cases, scientific value, extraordinary scenic impact and interesting morphogenetic processes on one hand and tourist and technical-sport use on the other, propose a very good scientific and tourist offer. in southern umbria there is a magnificent lithogenetic process: marmore falls. the majestic waterfall, made by river velino waters flowing into river nera, rises artificially, thanks to a waters diversion projected and realized since roman age. falling processes of waters, saturated of calcium carbonate, have raised year by year a difference in level. this has happened probably already for structural reasons, increasing therefore leaving of massive travertine deposits and forming a series of karst and “pseudo karst” shapes, both of them present in travertine basin of the cliff and in the entire territory of marmore piano. fruition of beauties of falls, lithogenetic processes linked to travertine deposition, “speleological” routes inside cliff caves, rafting and torrentism activities along nera river give to this site considerable potentialities. the springs of clitunno river, at the base of the village of campello range structure, represent a peculiar site linked to interaction of fluvial processes, karts and/or tectonic, through a complex genesis and evolution of karst “essurgenze”. therefore, they represent a unique landscape, extolled also by artists and poets of any age, from plinio to carducci. other geomorphosites are included in this survey because their genesis is bound to important towns, characterized by a rich cultural and historic wealth. the uniqueness of the location of some towns is due to well identifiable structural elements and morphogenetic processes whose study permits to understand for example why a city had a particular monumental and town-planning-development. perugia historical centre, e.g., is situated on the top of the hill identified as river tevere paleodelta, that flowed into tiberino lake in plio-pleistocenic age. structural landforms (mesas) of orvieto and civita di bagnoregio (fig. 3) are the results of morphoselection phenomena which isolated ranges (volcanic tuffs) and carved the spectacular badlands near civita. the “dying village” of civita represents a symbolic case of contradictory interventions to safeguard naturalistic aspects of a geomorphosite (badlands-landscape) and of its contemporary drainage work, held out of a historic centre consolidation. orvieto represents a spectacular example of structural cliff “lived” all along its surface and its thickness (several hollows inside the cliff were used in past times as reservoirs and cellars). in the area included between alfina plateau and the cliff, moreover, an inte287geotourism and geomorphosites ... resting archaeological site has been discovered, which testifies an intense human presence starting from etruscan epoch and adds value to this site. cerbaiolo hermitage, located on the top of a cliff involved in an important lateral spread phenomenon, or vernazzano tower, near trasimeno lake, leaning further to a subsidence movement, represent attractive sites for their characterizing evolutive aspects and well suitable to be put in well known tourist routes. trasimeno lake has been included in geomorphosites list for its peculiar character of tectonic lake (the most ancient in italy) and also for its faunistic and floristic characteristics all along its shores. near ficulle/allerona are visible particularly spectacular badlands-morphotypes, not very well-known yet, but worthy of being included in a geotouristic route, also taking into account its special character of terroir, giving important “wine-making” value to this zone; in these territories, in fact, the famous “muffati” wines are made and their production is linked to the local pedoclimate. at last, in the most southern area of umbria there fig. 2 gorghe wall. la muraglia naturale delle gorghe. fig. 3 civita di bagnoregio: the “dyng village”. civita di bagnoregio: la “città che muore”. 288 is the site of dunarobba fossil forest, which is a geological and palaeontologist worldwide known site, with a high geotourist value. the presence of several taxodiacee tree trunks, still in their physiologic position, allows to individuate the existence of a fluvial-lacustrine pliocenic territory and a landscaping wreckage from the past. 3. the structure of a g.i.s. (geographic information system) g.i.s. is a computer-based system for acquisition, storage, retrieval, analysis and display of spatial (locationally-defined) data. we could define geomorphosites as geographical data and we could import and analyze them like spatial objects. every object constitutes a georeferenceable form, according to a coordinate system. in addition, their complete and detailed knowledge necessarily implies the collection of individual and characterizing attributes. the structure of any g.i.s. instruments is representable by the formula: n [g – a] where n represents the number of informative layers to be implemented in a project (layers); g is the space-geographical component used to georeference. it is referred to geometric and topologic components of the objects. it describes the shape (geometry), the location (latitude and longitude) and the spatial relantionships (topology). topological properties of the figures do not change under bicontinuous one-to-one transformations (called homeomorphisms). two figures that can be deformed one into the other are called homeomorphic, and are considered to be the same from the topological point of view. the quantity a corresponds to the attributes characterizing the object. it is referred to statistical and qualitative data aspects. it describes the meaning and the magnitude of the data. theoretically, the variable a includes an unlimited whole of information, differing in contents and sizes (number, string, boolean, date). the different structure indeed leaves out any correlation, and, in most cases, does not allow various layers to communicate between each other in order to effectuate spatial analysis operations. on the other hand it gives the possibility the use of traditional calculations to compare alphanumeric values. the quantity g, on the contrary, aside from the kind of object which it refers to, maintains the same construction (latitude and longitude) and it gives the possibility to exchange information between layers and the application of new spatial operators, as connection, adjacency or closeness. it is this part of a gis structure that allows spatial analysis calculations. the approach to the use of a g.i.s. system can be of three types: cartographic, database oriented and analytical. in the first one, g.i.s. is only an interactive container of maps which can give back and in real time updatable cartographies. a map-oriented gis is a display system where each input data set is a raster document and the output is always a new map. the second approach is a management system based on the amount of imported attributes (dbms, data base management system) which is considered to be the essential part of the project, and onto the operator’s types applicable to analysis between different statements. the third one is based on analysis and model operations between implemented data. from this point of view, g.i.s. is a science concerning spatial information and analysis and not only a simple technology. this approach allows to realize the best from gis potentialities. in this research we present geomorphosites management with a database and analytical oriented g.i.s. system, in order to take advantage of the potentialities of sites for tourist purposes. the quantity g is compiled with coordinates referred to each geomorphosite, located as vector-punctual datum. the term a is articulated into a sequence of tables, whose structure is the project main element (data base oriented). these tables are linked one to another by a primary key (id field). the analysis is the final step of the project to find the closest facility (referring to anything providing a service like a geomorphosite, closest to a given location like hotels, roads, museums or other service areas) or to find the best route (the best way to get from one location to another or the best way to visit several locations). 4. the project implementation every g.i.s. project is made up of three phases: data collection, analysis and management of obtained elaborations. 4.1 inventory application collection of the data is the first step to build up a project and therefore its correct evaluation is fundamental in order to obtain, at the end of the analysis processes, the desired results. the quality of a project is not directly proportional to the quantity of imported data or to the number of effectuated analysis operations. on the contrary, the choice of initial data has to be limited to the less possible number of cartographic bases and databases required for further elaborations, also taking into account the high expenses for data acquisition. after this stage, a pre-elaboration is carried on, including eventual formats conversion, cartographic bases georeference and possible connections to pre-existing databases. a digital elevation model with pixel resolution 90x90m (taramelli & stark; http://geomorph.ldeo. columbia.edu/italy_srtm/2003) has been acquired in the project, covering the entire umbrian regional territory, a topographic base, with scale 1:25.000 igm and a roadgraphs with the main regional highways. the core of the project is constituted by a total amount of eight tables, on which the following analysis operations have been carried on. every table is made up of nineteen records (each record corresponds to a registered geomorphosite) and of a varying number of columns. every record contains an id (primary key) column, reproducing a progressive number, which is unique for each site. thanks to this l. gregori & l. melelli 289 column, one can elaborate joint operations between statement data in subsequent operations. each column field has two possible formats: a string, when it contains descriptive information related to the same column (e.g. formation type in geology) and numerical, if the information has to be quantified in order to be compared with other fields. in this case the numeric value 1 corresponds to a minimum weight of the expressed datum; 2 has a medium value and 3 a maximum one with a single score criterion based on bibliography and acquired knowledge. for those data to be inserted we have referred to the italian national geologic service forms for the census of geomorphosites on national territory, introducing suitable changes considering this project aims. tables can be grouped in three main knots: 1) scientific and identificative 2) kind of tourist interest 3) use and vulnerability in the first group information related to localization of geomorphosites are collected, together with their soundness and scientific typology characteristics. it includes the following tables: a. location; with columns named: • toponym (string); • town council (string); • province (string); • region (string); • latitude (string); • longitude (string); • above sea-level quote expressed in meters (numerical); • area occupied by geomorphosites expressed in square meters (numerical); • igm table scale 1:25.000 (string); • link to eventual further additional cartographic bases (string); b. interest level, the interest level degree of each geomorphosite with columns named: • world-wide (numerical); • european (numerical); • national (numerical); • local (numerical); c. geology, with columns named: • prevailing geological formation (string); • prevailing lithotype (string); • prevailing formation chronostratigraphic age (string); • shape formation age (string); d. processes generating shape, with columns named: • tectonic (numerical); • gravitative (numerical); • fluvial (numerical); • volcanic (numerical); • karst (numerical); • glacial (numerical); • periglacial (numerical); • aeolian (numerical); • marine (numerical); • anthropic (numerical). fields have a numerical value from 1 to 3 according to the importance every process had when the form has been generated. e. processes modelling shape. fields pattern is like the one reproduced for processes generating shape. the second group is marked with a single table, but it seems to be the most important to finalize geomorphosites from a tourist point of view, because it contains information related to better known and usual tourist interests. numerical values, identifying for each field a minimum and a maximum value, are the results of a careful bibliographic research. the choice of column types has been conditioned by tourist features in umbria, but it is also possible to modify this number with different typologies for different territorial realities. a. other interest, with columns named: • didactic (numerical); • cultural and artistic (numerical); • historical (numerical); • museums related (numerical); • hiking (numerical); • sport (numerical); • oeno-gastronomic (numerical); • local craftsmanship (numerical); • festival and local traditions (numerical). the last group lists informations about the accessibility of each geomorphosite and about hosting facilities for tourists with different needs. moreover, one can quantify hazard conditions to which a geomorphosite can be exposed, taking into account a future preservation of the site. groups of data are made up of two statements: a. use, with columns named: • equipped area (numerical); • practicability (numerical); • vulnerability level (numerical). b. exploitation-preservation, with columns named: • preservation state (numerical); • risk of natural deterioration (numerical); • risk of anthropic deterioration (numerical); • protection need (numerical). 4.2 analysis application for this project we have used the software esri arc view 3.3. using the column of identification codes, which are the same for each statement, it is possible to realize joint operations and queries between tables (fig. 4 and fig. 5). tables structure has the purpose of creating new and temporary tables satisfying each tourist needs. relational db structure is absolutely the most suitable in this way, allowing the connection of different fields through the common id, on which one can effectuate specific queries. it is possible to question something like “select all geomorphosites having an at least national level of interest, providing with equipped areas of a medium level and having in the closeness interesting oeno-gastronomic routes”. this command is translated into simple algorithms, easy to build through specific tools of relative gis software. therefore it is possible to satisfy different tourist profiles. the temporary tables calculated from various queries reflects specific requirements. the tourist operators have the possibility to geotourism and geomorphosites ... 290 l. gregori & l. melelli fig. 4 example of table, reproducing different types of interests related to geomorphosites, with numerical score for each cell. esempio di selezione su tabella riportante i diversi interessi correlati ai geomorfositi con valori numerici in ogni cella. fig. 5 example of query to locate geomorphosites with value, related to the presence of excursion and partly eno-gastronomical routes. yellow pointed out records represent geomorphosites satisfying this query. esempio di interrogazione volta all’individuazione dei geomorfositi con medio -alto valore eno-gastronomico e alto valore escursionistico. i records contrassegnati in giallo rappresentano i geomorfositi in grado di soddisfare l’interrogazione. select only the fields linked to tourist request interests (fig. 5). it is possible, in this way, to create temporary tables referred only to some specific geomorphosites. these geomorphosites have their specific attributes regarding scientific value and location, but above all, they have specific characteristics that satisfy the tourist interests, like cltural-artistic or oeno-gastronomic targets. it is possible to induce a larger number of tourists to visit geomorphosites if they know that they can find in the same places, traditional tourists attractions. but operations of “selection”, “connection” and “query” on statements can be developed by any program of db management. the added value of a gis system is, in this specific case, the capacity of positioning the obtained results on georeferenced maps (selected geomorphosites). moreover, the importation of the project road-graphs, permits to build real routes to be inserted into tourism proposals, without forcing the visitor to follow pre-packaged and in some cases far away from his own interests trips. network analysis tools in different gis allow to find the best route and the closest facility to a service areas. by finding the best route it is possible to plan the visits to several locations and the related closest services. in figure 6 it is possible to observe the best routes between several geomorphosites (in blue) or the shortest road (in red). 4.3 management system in this phase generally thematic charts, cartograms, diagrams, graphics and statistics, and descriptive reports are produced to support decisional projects of future administrations. in the case of geomorphosites, final output aims to determine, on cartographic base (and therefore immediately receivable from tourists) sets of selected sites. cartographic base can show several itineraries linking different sites and containing a set of additional information. the legend enclosed in each map can be “widen” in several ways, showing information otherwise implicit on a simple paper support. 5. conclusion geotourism is taking its first steps both in italy and abroad. recently cultural standard of medium tourists is increasing and therefore new realities like geosites/geomorphosites can be the object of a new interest. routes conjugating morphologic characters and tourist interests give the opportunity to convey a wider tourist user to geomorphosites zones. particularly the new approach to geotourism starting from g.i.s. is founded on geographic nature of geomorphosites and contemporary on the supporting structure of g.i.s. systems, that permits to implement a project, oriented to the management of attributes of these sites. typical operations of geographic informative systems allow, in this way, to obtain personalized destinations and routes collecting tourists’ interests, and at the same time, more scientific information about the sites. considering the fact that g.i.s. systems are growing fast both in private and in administrative sector, that they can manage a theoretically endless number of information and can correlate new and traditional cartography, it is evident the utility of biasing the research towards this field. therefore, an increasing development of geotourism sector could boost the diffusion of knowledge within the limits of earth science and a planning in the distribution of tourist interest sites inside known routes and farther from traditional but still interesting tracks. references brancucci g. & burlando m. (2000) la salvaguardia del patrimonio geologico. scelta strategica per il territorio. l’esperienza della liguria franco angeli ed., 96 pp. carton a., coratza p & marchetti m. (2003) methodological proposal for mapping geomorphosites proc. workshop “geomorphological sites: assessment and mapping”, cagliari (italy), 1-5 october 2003, pp. 21-22. d’andrea m. & di legino f. (2003) progetto “conservazione del patrimonio geologico italiano”. i censimenti sui siti di interesse geologico in italia, aggiornato a dicembre 2002 geologia dell’ambiente, sigea, 1, pp. 154-161. giusti c. & gonzalez-diez a. (2000) a methodological approach for the evaluation of impact on sites of geomorphological interest (sgi), using gis techniques int. archives of photogrammetry and remote sensing, vol. xxxiii, (b7), pp. 47-53. massoli-novelli r. (2003) geositi, geoturismo e sviluppo sostenibile geologia dell’ambiente, sigea, 1, pp. 167-170. 291geotourism and geomorphosites ... fig. 6 example of a map with geomorphosites (blue targets). the geomorphosites marked with red targets are selected by a specific query (high value of hiking routes). the red line shows the best route (best accessibility) to visit all the selected geomorphosites. the blue line shows the shortest route that link the selected geomorphosites. esempio di cartografia riportante una serie di geomorfositi (contrassegnati da simboli in blu). i siti evidenziati in rosso sono quelli selezionati sulla base di un’interrogazione spaziale (quali sono i siti con maggior valore dell’aspetto escursionistico). la linea rossa mostra il percorso che collega i suddetti geomorfositi con strade facilmente percorribili. la linea blu, al contrario, mostra il percorso più breve tra i geomorfositi selezionati. panizza m. (1992) sulla valutazione dei beni ambientali mem. descr. carta geol. d’it., xlii, pp. 479-484. panizza m. & piacente s. (2002a) geositi nel paesaggio italiano. ricerca, valutazione e valorizzazione. un progetto di ricerca per una nuova cultura geologica geologia dell’ambiente, sigea, 2, pp. 3-4. panizza m. & piacente s. (2002b) the geomorphosites between scientific research, cultural integration and artistic suggestion workshop geomorphological sites: research, assessment and improvement, modena (italy) 19 -22 june. poli g. (1999) geositi testimoni del tempo. fondamenti per la conservazione del patrimonio geologico regione emilia-romagna, ed. pendragon, 258 pp wimbledon w.a.p. (1996) geological world heritage: a global comparative site inventory to enable prioritisation for conservation proceedings ii° int. sympos. progeo on conservation of our geological heritage, serv. geol. naz., 20-22 may, rome, pp. 45-60. 292 l. gregori & l. melelli base mammal fossil record, depositional setting, and sequence stratigraphy in the middle-upper pleistocene of roman basin maria rita palombo 1,2 & salvatore milli 1,2,3 1dipartimento scienze della terra, università sapienza, roma 2cnr, istituto di geologia ambientale e geoingegneria, roma 3 isipu, istituto italiano di paleontologia umana corresponding author: m.r. palombo <mariarita.palombo@uniroma1.it> abstract: palombo m.r. & milli s., mammal fossil record, depositional setting, and sequence stratigraphy in the middle-upper pleistocene of roman basin. (it issn 0394-3356, 2010) in the roman basin, and particularly in the ponte galeria area, quaternary vertebrate remains are preserved both in continental and marine sedimentary successions. the facies and sequence stratigraphical analyses carried out in the last twenty years on such deposits led to a detailed local chronostratigraphical framework which fixes some physical and temporal limits to the fist/last local appearances of some mammalian taxa. this contributes to a better definition of faunal complexe, characterizing the biochronological setting proposed for the quaternary large mammal faunas of the italian peninsula. riassunto: palombo m.r. & milli s., record fossile a mammiferi, assetto deposizionale e stratigrafia sequenziale della successione del pleistocene medio-superiore del bacino romano. (it issn 0394-3356, 2010) nel bacino romano, ed in particolare nell’area di ponte galeria, resti di vertebrati quaternari sono presenti in successioni sedimentarie sia continentali sia marine. l'analisi di facies e stratigraficosequenziale condotta su tali depositi nel corso degli ultimi venti anni ha portato ad un dettagliato inquadramento cronostratigrafico dei depositi e ha consentito di fissare limiti temporali per la prima comparsa di alcuni taxa, in particolare grandi mammiferi fra cui specie non ancora segnalate nel resto della penisola, contribuendo così ad una migliore caratterizzazione dello schema biochronologico proposto per le faune a grandi mammiferi del quaternario della penisola italiana. key words: large mammals, biochronology, sequence stratigraphy, pleistocene, roman basin. parole chiave: grandi mammiferi, biocronologia, stratigrafia sequenziale, pleistocene, bacino romano. il quaternario italian journal of quaternary sciences 23(2), 2010 257-262 1. introduction the sedimentary cyclicity characterizing the quaternary stratigraphical record represents an outstanding example on how climate and glacio-eustatic signals could affect the stratigraphical setting of sedimentary successions. the quaternary sedimentary record of the roman basin hightlights this climate-driven cyclicity by a continuous modification of landscape and of depositional environments. moreover, the peculiar environmental conditions and the paleogeographical setting of the latium area during the middle-late pleistocene (fig. 1) promoted the diffusion of a rich mammal fauna and their postmortem preservation in deposits of different sedimentary environments. the latters mainly range from transgressive fluvial and fluvio-palustrine deposits, filling incised valleys (tst), to highstand barrier island–lagoon deposits (hst) (milli et al., 2008). 2. geological and sequence-stratigraphical setting the investigated area is located along the latium tyrrhenian margin that has undergone extensional tectonic processes since the late miocene, in connection with the opening of the tyrrhenian basin, and intense volcanic activity that reached a climax in the middlelate pleistocene. during the pleistocene the geological and palaeogeographical evolution was controlled by the close interaction among three main processes: the glacioeustatic sea-level fluctuations related to quaternary climatic changes, the volcanic activity, and the tectonic uplift of the latium tyrrhenian margin. starting by the pioneering work by conato et al . (1980), the pleistocene succession mainly cropping out in the ponte galeria area was subdivided into informal lithostratigraphic units named, from the oldest to the youngest, monte mario formation (lower pleistocene, ‘calabrian’), and ponte galeria, s. cosimato, aurelia, and vitinia formations ranging in age from the latest early pleistocene to the late middle pleistocene (‘ionian’) (fig. 2). in the last years, the stratigraphic resolution of sedimentary successions has notably improved due to development of sequence stratigraphic concepts. thanks to this methodology, the spatial-temporal relationships between terrestrial and marine depositional systems in relation to sea-level changes have been better defined. basing on a detailed facies and physical stratigraphic analysis of the pleistocene/holocene sedimentary succession, milli (1992, 1994,1997, 2006) refined the stratigraphy of the 258 m.r. palombo & s. milli area defining several fourth-order sequences, stacking to form two composite third-order sequences named monte mario sequence (mms) and ponte galeria sequence (pgs) (fig. 1). most of the mammal remains are contained in the pgs. the pgs extends for about 30 km, in nw-se direction, along the latium coastline; in the area between roma and the coastline its thickness varies from 10-15 m to 100-110 m, depending on the intensity of the erosional phases connected with cyclic, recurrent lowerings of relative sea level. the pgs consists of ten 4th-order sequences with an approximate period of 100,000 years (fig. 1); the boundaries of these high-frequency sequences are expressed by sharp erosional surfaces, recording basinand downward shifts of facies, subaerial exposure and by paleosols in the interfluve areas, which put in contact sediments belonging to different depositional systems (milli et al., 2008 and references therein). the fourth-order depositional sequences are characterised by a seaward stack, which is opposite to the trend that the pgs would have had if controlled by glacio-eustasy alone. this trend is though to be the result of the close interaction between high frequency sealevel fluctuations related to glacio-eustasy and the tectonic uplift, which comprises also a local volcanicallyinduced component, particulartly strong during the late quaternary time, that affected the latiumtyrrhenian margin during the middle-late pleistocene. in particular the lower four 4th-order sequences (pg0 to pg3) stack to form the early lst, which developed during a period of relative sea-level fall producing a series of prograding and downstepping wedges-shaped high-frequency sequences. stratigraphical relationships between pg4 and the underlying sequences enable us to assign it to the late lst, whereas sequences from pg5 to part of pg8 can be ascribed to the tst, and the sequence pg9 entirely to the hst (fig. 1) (milli et al., 2008). 3. mammalian remains from the ponte galeria sequence: biochronological framework in the rome urban area, a molar tooth of mammuthus meridionalis has been found in the marine sands of the mms, attributed to the lower pleistocene (santernian), while in the in the area between rome and the latium coastline, most of the mammalian remains come from both continental and marine sediments of the pgs (fig. 1,3). particularly, in the ponte galeria area, the richest local faunal assemblages (lfas) come from the pg2, pg3 and pg4 4th-order sequences, developed during a period of long term (i.e. related to the 3rd order cyclicity) average sea-level fall and initial rise. fossil bones have been found in transgressive fluvial and fluvio-palustrine deposits filling incised valleys (tst) and in highstand barrier island-lagoon deposits (hst) of the 4th order sequences (see milli & palombo, 2005; milli et al., 2008). remains from pg2 to pg4 sequences represent the “classic italian galerian fauna” (see ambrosetti, 1967; ambrosetti et al., 1972) ascribed to the middle galerian land mammal age (lma) (gliozzi et al., 1997; palombo, 2009). few teeth of “cold” fig. 1 integrate chronostratigraphy and sequence stratigraphy of the pleistocene deposits of the roman basin and biochronological setting of italian mammal faunas. small mammals (prolagurus pannonicus and predicrostonyx sp., ponte galeria 1 lfa) have been retrieved from the lacustrine lagoonal deposits of pg1 sequence (fontignano, helicella clay), which recent paleomagnetic data have attributed to an inverse polarity (see kotsakis et al., 1992; marra et al., 1998). these data, together with stratigraphic and sedimentological data, (see, milli, 1997) indicate that these sediments were deposited during a cold climate phase (mis 20); they have been also attributed to the late lowstand systems tracts of the pg1 sequence (milli, 1997). in the beach sand and gravel deposits underlying the venerupis senescens clays (hst of sequence pg2, whose age roughly ranges from 0.72 to 0.68 ma) the first local appearance (fla) of crocuta crocuta, mammuthus trogontherii, megaloceros savini, and hemibos galerianus represents also the lowest occurrences of these taxa in the italian peninsula (fig. 3). among other taxa retrieved from these deposits, equus altidens f irst appeared in italy during the latest villafranchian, stephanorhinus hundsheimensis and praemegaceros verticornis are first recorded shortly before and at the beginning of the jaramillo subchrons, whilst palaeoloxodon antiquus, cervus elaphus acoronatus and bison schoetensacki appeared in the latest early pleistocene (palombo, 2009 and references therein). the appearance of spotted hyaena would suggest that this lfa (ponte galeria 3 lfa, palombo, 2004, 2009) would be younger than the slivia lfa (northeastern italy), where pachycrocuta brevirostris is 259mammal fossil record, depositional setting, and ... still present. but, is this enough to support the petronio and sardella’s hypothesis (petronio & sardella, 1999) according to which slivia lfa and ponte galeria 2 lfa belong to two distinct faunal units? taking into account the doubtful identification of some main herbivores of the slivia local fauna, as well as the scanty knowledge of small mammals belonging to ponte galeria 2 lfa, the possibility that slivia and ponte galeria lfas belong to the same fu cannot be ruled out (see palombo, 2004, 2009). moreover, much more data need to clarify the dynamics of c. crocuta/p. brevirostris replacement in the western mediterranean, where p. brevirostris and c. crocuta seem to have been both present across the early/middle pleistocene boundary. for instance, in the iberian peninsula p. brevirostris is recorded during the latest pleistocene at vallparadís (terrassa, catalonia) in deposits correlated with mis 21 (madurell-malapeira et al., 2010), while c. crocuta is present, just before the matuyama/bruhnes boundary transition, in the td6 level from gran dolina (atapuerca, north spain) (cuenca-bescos & garcia, 2007). the laf (ponte galeria 3) from the hst beach deposits and the lacustrine-palustrine deposits of pg3 sequence (about 600-550 ka) (fig.1,3), counts several vertebrates remains (birds, amphibians and reptiles, small and large mammals), among which the vole arvicola mosbachensis (milli & palombo, 2005; sardella et al., 2006) confidently confirms that the lfa can be ascribed, together with the almost coeval isernia la fig. 2 – high-resolution strathigraphical cross-section and depositional setting of the third-order ponte galeria sequence (pgs) between the town of rome and the latium coastline (modified after milli, 1997). 260 pineta lfa (central italy) (coltorti et al., 2005, and references therein) to the oldest toringian fauna recorded in italy to date (sala & masini, 2007) (fig. 1,3). the ponte galeria 3 lfa is fairly rich and diversified, including together with allocricetus bursae, a primate (macaca sylvanus), a few carnivores such as meles meles, lynx sp., a hyaena whose taxonomical identification is still matter of debate, (‘‘hyaena prisca’’ = pliohyaena perrieri according to turner et al. 2008), as well as large (stephanorhinus cf. s. hundsheimensis, equus altidens, equus suessenbornensis, hippopotamus ex gr. h. antiquus, bison cf. b. schoetensacki) and middle-sized herbivores (sus scrofa priscus, “pseudodama” sp., cervus elaphus acoronatus) (caloi & palombo, 1986; petronio & sardella, 2001; milli & palombo, 2005). in deposits of about 500 ka belonging to the hst of the pg4 sequence, some vertebrate remains (testudinata, some bones of a disarticulated skeleton of palaeoloxodon antiquus, hippopotamus sp., dama sp., and bos primigenius) have been found at the casal selce quarry (casal selce 2 lfa) (milli et al., 2005). these deposits are represented by fluvial braided sandy deposits at the base, passing upward to lagoonal mud and silty-sands and muds of palustrine-lacustrine environment (milli, 1997). the deposits are characterized by a high component of volcaniclastic material (ranging in age between 500 and 485 ka, see karner & renne, 1998; karner & marra, 1998), which was emplaced through fall events (milli et al., 2008). the lfa could be ascribed to the late galerian fontana ranuccio fu, as well as the sporadic remains of late galerian taxa that have been uncovered in sediments interbedded with the sabatini volcaniclastic deposits (tufo giallo della via tiberina or tufi stratificati varicolori di sacrofano) (e.g., cervus elaphus eostephanoceros, hippopptamus ex gr. h. amphibius). new studies carried out on the incomplete skull of ovis ammon antiqua reported by portis (1917) as hypothetically retrieved from deposits overlaying the “pozzolane grigie” in the magliana area, enable us to clarify that the argali skull is at least younger than the beginning of the volcanic activity in the study area and to hypothesize that it was possibly found in the tst/hst lacustrine-lagoonal deposits of the pg4 sequence (see rozzi et al., in press for a discussion). accordingly, the incomplete skull of ovis ammon antiqua should be referred to the fontana ranuccio fu and regarded as penecontemporaneous with or slight older than the argali from visogliano (northeaster italy), the only other specimen of such a rare species thus far recorded in italy (abbazzi et al., 2000; falgueres et al., 2008). lfas belonging to aurelia formation/pg6 and vitinia formation/pg7 (fig. 1) sequence are characterized by the association of palaeoloxodon antiquus with large bos primigenius, accompanied by cervids (dama clactoniana, dama dama tiberina, cervus elaphus, capreolus capreolus and megaloceros giganteus), while equus ferus may be present, at times in abundance, and equus hydruntinus sporadically occurs. rhinoceroses (stephanorhinus hemitoechus, s. hundsheimensis and s. kirchbergensis), hippopotamus, wild boar and middlesized carnivores (canis lupus, vulpes fig. 3 biochronology of selected large mammals found in the monte mario and ponte galeria third-order sequences (roman basin). m.r. palombo & s. milli 261 vulpes) are often present, while the large (ursus spelaeus, panthera spelaea, panthera pardus) and small (mustelidae) carnivores are poorly documented (palombo et al., 2003 and references therein; milli et al., 2008). these lfas can be referred to the early aurelian lma (torre in pietra fu) (see palombo et al., 2004; palombo, 2009 for a discussion). 4. remarks in the roman basin, the vertebrate remains collected from the high-frequency depositional sequences should be ascribed to faunal complexes with a temporal range comparable to the range of the high-frequency sequences. although the possibility of exhumation exists, the type of fossil remains, their mode of preservation, and the characters of the depositional environments suggest that faunal remains have the same age of the deposits within which they are contained. accordingly, the sequence-stratigraphic framework as well as the radiometric and palaeomagnetic data (see milli, 1997; karner et al., 2001; marra et al., 2008 and references therein) enable us to constrain the age of the lfas, to better calibrate bioevents both with the geochronology and oxygen isotope signals, and to improve our knowledge on local highest occurrences/last appearances of mammal taxa in the italian peninsula. acknowledgments the authors thank the anonymous reviewers for their comments to the manuscript. references abbazzi l., fanfani f., ferretti m. p., rook l., cattani l., masini f., mallegni f., negrino f., tozzi c. (2000) new human remains of archaic homo sapiens and lower palaeolithic industries from visogliano (duino aurisina, trieste, italy) – journal of archaeological science, 27, pp. 1173-1186. ambrosetti p. (1967) cromerian fauna of the rome area. quaternaria, 9, pp. 1–17. ambrosetti p., azzaroli a., bonadonna f.p. & follieri m. (1972) a scheme of pleistocene chronology for the tyrrhenian side of central italy. bollettino della società geologica italiana, 91, pp. 169-184. caloi l. & palombo m.r. (1986) resti di carnivori in livelli del pleistocene medio inferiore, affioranti al km 2 del g.r.a. (roma). bollettino del servizio geolologico d’ italia, 104 (1983-84), pp.141-15. coltorti m., feraud g., marzoli a., peretto s., tonthat c., voinchet t.p., bahain j.-j., minelli a. & thunhohenstein u. (2005) new 40ar/39ar, stratigraphic and palaeoclimatic data on the isernia la pineta lower palaeolithic site, molise, italy. quaternary international, 131, pp. 11–22. conato v., esu d., malatesta a. & zarlenga f. (1980) new data on the pleistocene of rome . quaternaria, 22, pp. 131–176. cuenca-bescos g. & garcia n. (2007) biostratigraphic succession of the early and middle pleistocene mammal faunas of the atapuerca cave sites (burgos, spain). courier forschungsinstitut senckenberg, 259, pp. 99-100. falguères ch., bahain j.-j., tozzi c., boschian g., dolo j. m., mercier n., valladas h., yokoyama y. (2008) esr/u-series chronology of the lower palaeolithic palaeo-anthropological site of visogliano, trieste, italy. quaternary geochronology, 4, pp. 390-398. gliozzi e., abbazzi l., ambrosetti p., argenti p., azzaroli a., caloi l., capasso barbato l., di stefano g., esu d., ficcarelli g., girotti o., kotsakis t., masini f., mazza p., mezzabotta c., palombo m.r., petronio c., rook l., sala b., sardella r., zanalda e. & torre d. (1997) biochronology of selected mammals, molluscs, ostracods from the middle pliocene to the late pleistocene in italy. the state of the art . rivista ital iana di paleontologia e stratigrafia, 103 (3), pp. 369-388. karner d.b. & marra f. (1998) correlation of fluvio deltaic aggradational sections with glacial climate history: a revision of the pleistocene stratigraphy of rome. bulletin geological society of america, 110, pp. 748-758. karner d.b. & renne p.r. (1998) 40ar/39ar geochronology of roman volcanic province tephra in the tiber river valley: age calibration of middle pleistocene sea-level changes. bulletin geological society of america, 110, pp. 740-747. karner d.b., marra f. & renne p.r. (2001) the history of the monti sabatini and alban hills volcanoes: groundwork for assessing volcanic-tectonic hazards for rome. journal of volcanology and geothermal research, 107, pp.185-219. kotsakis t., esu d. & girotti, o. (1992) a postvillafranchian cold event in central italy testified by continental molluscs and rodents. bollettino della società geologica ital iana, 111 , pp. 335–340. madurell-malapeira, j., minwer-barakat r., alba d.m., garcés m., gómez m., aurell-garrido j., rosmontoya s,, moyà-solà s. & berástegui x. (2010) -the vallparadís section (terrassa, iberian peninsula) and the latest villafranchian faunas of europe, quaternary science reviews (2010), doi:10.1016/j.quascirev.2010.09.020 marra f., florindo f. & karner d.b. (1998) paleomagnetism and geochronology of early middle pleistocene depositional sequences near rome: comparison with the deep-sea δ18o record. earth and planetary science letters, 159, pp. 147–164. marra f., florindo f. & boschi e. (2008) history of glacial terminations from the tiber river, rome: insights into glacial forcing mechanisms . paleoceanography, 23, pa2205, doi:10.1029/ 2007pa001543,2008. milli s. (1992) analisi di facies e ciclostratigrafia in depositi di piana costiera e marino marginali. un esempio nel pleistocene del bacino romano. unpublished ph.d. dissertation, università di roma ‘‘la sapienza’’, roma. milli s. (1994) high-frequency sequence stratigraphy of the middlelate pleistocene to holocene deposits of the roman basin (rome, italy): relationshimammal fossil record, depositional setting, and ... 262 ps among high-frequency eustatic cycles, tectonics and volcanism. in: posamentier h.w. & mutti e. (eds.), second high-resolution sequence stratigraphy conference, tremp, spain, 20–27 june 1994. milli s. (1997) depositional setting and high-frequency sequence stratigraphy of the middleupper pleistocene to holocene deposits of the roma basin. geologica romana, 33, pp. 99–136. milli s. (2006) the sequence stratgraphy of the quaternary successions: implication about the origin and filling of incised valleys and mammal fossil record. in: sabato l., spalluto l. & tropeano m. (eds.), workshop thirty years of sequence stratigraphy: application, limits and prospects. bari, 2 october 2006, pp 27-28. milli s., moscatelli m., palombo m.r., parlagreco l. & paciucci m. (2008) incised-valleys, their filling and mammal fossil record: an example in the middle-upper pleistocene deposits of the roman basin (latium, italy). geoacta, sp1, pp. 67-88 milli s., palombo m.r. (2005) the hight-resolution sequence stratigraphy and the mammal fossil record: a test in the middle-upper pleistocene deposits of the roman basin (latium, italy). quaternary international, 126-128, pp. 251-270. milli s., palombo m.r., patera a., moscatelli m., anzidei a.p. & cazzella g. (2005) new elephant remains in the early middle pleistocene of the roman basin (latium, italy): taphonomy, sedimentology, and gis methodology. in: agenbroad l.d. & symington r.l. (eds.): 2nd world of elephants congress: short papers and abstracts. mammoth site scientific papers, 4, pp. 114-119. palombo m.r. (2004) guild of large mammals from the pliocene to the late pleistocene in the italian peninsula. in: baquedano e. & rubio s. (eds.), homenaje a emiliano aguirre. zona argueologica 4 (2 paleontologia), museo arqueológico regional, madrid, pp. 372–391. palombo m.r. (2009) biochronology of terrestrial mammals and quaternary subdivisions: a case study of large mammals from the italian peninsula. il quaternario, 22(2), pp. 291-306. palombo m.r., azanza b. & alberd, m.t. (2003) italian mammal biochronology from latest miocene to middle pleistocene: a multivariate approach. geologica romana, 36 (200-2002), pp. 335–368. palombo m.r., milli s., & rosa c. (2004) remarks on the late middle pleistocene biochronology of the mammalian faunal complexes of the campagna romana. geologica romana, 37 (2003), pp. 13514. petronio c. & sardella r. (1999) biochronology of the pleistocene mammal fauna from ponte galeria (rome) and remarks on the middle galerian faunas. rivista italiana di paleontologia e stratigrafia, 105, pp.155-164. petronio c. & sardella r. (2001) mammal faunas from ponte galeria formation. guide book euromam 2001, galerian and aurelian fossiliferous localities in the rome area, pp. 22-24. portis a. (1917) il rinvenimento di ovis antiqua pommerol in territorio di roma – bollettino della società geologica italiana, 36, pp. 223-232. sala b. & masini f . (2007) the late pliocene and pleistocene small mammal chronology in the italian peninsula. quaternary international, 160 (1), pp. 4-16. sardella r., palombo m.r., petronio c., bedetti c. & pavia m., (2006) the early middle pleistocene large mammal faunas of italy: an overview . quaternary international, 149, pp. 104-109. shackleton n.j. (1995) new data on the evolution of pliocene climatic variability. in: vrba, e.s., denton, g.h., partridge, t.c. & burckle, l.h. (eds), paleoclimate and evolution, with emphasis on human origins. yale university press, new haven and london, pp. 242–248. rozzi r., palombo m.r. & barbieri m. (in press) the argali (ovis ammon antiqua) from the ponte galeria area (rome). il quaternario. turner a., anton m. & werdelin l. (2008) taxonomy and evolutionary patterns in the fossil hyaenidae of europe. geobios 41 (b), pp. 677–687. ms. ricevuto il 4 agosto 2010 testo definitivo ricevuto il 18 novembre 2010 ms. received: august 4, 2010 final text received: november 18, 2010 m.r. palombo & s. milli amq_27(2) 11 available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 27 (2), 2014, 105 118 an integrated research on the caprelle caves (central italy): genesis and palaeoenvironmental inferences from the upper pleistocene deposits. sandro galdenzi¹, mara loreti², anna maria mercuri2 ¹ viale verdi 10, jesi (italy) ² lab. palinologia e paleobotanica, dip. scienze della vita, università di modena e reggio emilia, italy corresponding author: m. loreti <heidi52it@yahoo.it> abstract: this paper reports on geomorphologic, geochronologic and hydrologic data, interrelated with pollen data from the sediments of the caprelle caves, located in the umbria-marche apennines. the paper is a contribution to the understanding of cave genesis. the caves open between 795 and 880 m of altitude in the steep slope at the northern margin of the piani di monte lago, and their present entrance is due to the headward erosion of a minor subsequent valley. the two caves belong to the same hydrogeologic system, even if they are not directly interconnected. the grotta piccola di caprelle (gpc) is a ~100 m long tube that feeds a permanent spring, while the grotta di caprelle (gc) is a mainly vertical cave (76 m deep), with some sub-horizontal passages at different levels in its lower part; excluding the permanent stream in the gpc, an intense flow of vadose water occurs only in the gc during the wet periods. the geomorphic setting suggests that the cave development begun before the deepening of the hydrographic surface. excluding abundant clastic autogenic deposits, the cave fills are mainly calcite speleothems, fine-grained floor deposits with a minor sand content, and thin muddy wall coating. morphological analysis shows that same processes with different intensity acted several times during the history of these caves. in particular, in gc the predominance of vertical water flows has produced an overlapping of forms and deposits, making difficult the stratigraphical analysis of continuous sequences. calcite and sediment samples were dated with the u/th method. they showed that the chemical deposition inside the caves had occurred since before 92.5 ka bp, when the carving and enlargement of the caves by water flow action had already allowed the formation of concretions. the genesis of the caprelle caves has to be placed at a moment preceding this date, when cave morphology was already similar to the present-day structure. an iron-manganese sediment sample dated to 37.6 ka bp, and the overlying thin crust of calcite on the wall gave an age of 28.4 ka bp. pollen analysis of the sediment contributed to the reconstruction of the environmental context and permitted some inferences on climate. pollen spectra suggest, in fact, that the sediment containing pollen, together with gravels and sand, might have episodically deposited during short dry/cold, and probably wet/cool climatic phases, as expressed by steppe, grassland and a poor woodland cover. keywords: quaternary, karst caves, geomorphology, geochronology, palynology, palaeoenvironment, late pleistocene, central apennines, italy. 1. introduction epigenic caves are common throughout the mountain chain of the umbria-marche apennines, in central italy (galdenzi, 1988, 1996; de waele et al., 2014). these caves are related to fast surface water flow circuits and are formed by the dissolution action of the co2, which is present in infiltrating meteoric water. two main types of caves are common in the area: vertical shafts that open on the mountain upper surface, and active or temporary active emergences at foot of the mountain, generally located few tens of meters above the local base level. the caves presented in this paper are located near the agolla village in the commune of sefro (macerata, marche; fig. 1). they represent an atypical situation in the region, as a mainly vertical cave, the grotta di caprelle (gc), is almost directly connected with a horizontal active emergence, the grotta piccola di caprelle (gpc), at high elevation in the mountainside. the general features of the caves and their relation with the geologic setting have been described elsewhere by galdenzi (1983) and galdenzi et al. (2008). this paper reports on new data on geomorphology, geochronology and hydrology of the caves, and presents pollen analyses carried out on sediments collected into the caves. although the complexity of their morphology makes it difficult to interpret unambiguously the stratigraphic situation, this study contributes to understanding cave development in the area and provides suggestions on which palaeoclimatic and palaeovegetational conditions existed in the region during the latest quaternary. 2. the study area 2.1. geographical and geological setting the studied caves are located in the inner ridge of the umbria-marche apennines, 60 km from the adriatic sea, between the valleys of the rivers chienti in the south and potenza in the north (fig. 1a). the mountain chain consists of northeast verging folds and thrust belt, involving the mainly carbonate rocks of the umbriamarche meso-cenozoic sequence (minetti et al., 1991, and references therein). specifically, in the cave area, there are two main overthrusting anticlines trending n-s and formed by jurassic and early cretaceous units; they are divided by an interposed synform structure with upper cretaceous and paleogene deposits, that comprises two main synclines (mt. lago and agolla) (fig. 1b). the eastern anticline (mt. torroncello-mt. di mistrano) overthrusts the miocene terrigenous sequence outcropping at the foothill (mt. primo mt. cavallo thrust) (calamita & pierantoni, 1993), while the inner one (mt. cimara anticline) has a minor throw on the carbonates of the interposed syncline. this syncline corresponds to a morphological depression and comprises some minor folds. the chain has been in part dissected by plio-quaternary normal faults. one of the most important geomorphic structure of the area, the piani di monte lago, formed by two close depressions, almost 2 km wide developed in the central syncline. this morphological structure represents a remnant of the erosion surface that evolved during the late pliocene and early pleistocene, when in the whole area large paleovalleys formed into a pre-existing "planation surface" (ciccacci et al., 1985). the regional uplift at the end of the early pleistocene enhanced the linear erosion in the river valleys that entrenched into the old surface producing the present deep valleys (ambrosetti et al., 1982; d’agostino et al., 2001; bartolini et al., 2003). the surface drainage is scarce in the limestone outcrops at the surface of the mountains, where a diffuse autogenic recharge feeds the karsic circulation of water, though typical surface landforms, as dolinas, are uncommon. in the syncline, the two close areas of piani di mon 106 galdenzi s. et al. fig. 1 study area: a) location map; b) the upper part of the valley, above the entrances of the two caves; c) the steep slope at the head of agolla valley, with the location of the caves. fig. 2 geologic map of the study area (after galdenzi et al., 2008, modified). 107 te lago are filled by thin sediments and drained by a ponor. these two poljes were joined through a deep artificial trench dug in 1458 to facilitate the drainage of the upper polje (falaschi, 1987). after rain periods and during the snow melting, a wide temporary lake is formed in the lower plain. at north, the valley of the river potenza incised transversally the mountain ridge, and the steep head of its southern tributaries reaches the margin of the piani di monte lago, in the area where the studied caves are located (fig. 1c). particularly, the caves developed in the central synform structure, formed in the thin-bedded cretaceous formations (maiolica, marne a fucoidi, scaglia bianca and scaglia rossa) (fig. 2). in detail, both the caves open in the vertical eastern limb of a minor anticline that divides two main synclines, and are wholly comprised in the upper member of the scaglia bianca formation (fig. 3). the scaglia bianca (upper albian-lower turonian) comprises two members: the upper one is 30 m thick, and is formed by white limestone with black chert beds; while the lower member consists of 30 m thick body of whitish marly limestone with chert beds. the underlying formation (marne a fucoidi, lower aptian-upper albian) is an alternation of polychrome marls, marly limestones and marly claystones, with a total thickness of 40 m. the overlying scaglia rossa (lower turonian-lutetian) is formed by reddish limestone, and comprises levels with different contents of chert or marl, and has a total estimated thickness of 250 m. scaglia bianca and scaglia rossa form a permeable hydrogeological complex, while the underlying marne a fucoidi represents an aquiclude interposed between the scaglia hydrogeological complex and the underlying maiolica (upper tithonian-lower aptian), which is another thick, permeable carbonate unit. the attitude of the low-permeable marlstone (marne a fucoidi) has an important influence on the groundwater drainage, dividing the scaglia aquifer in the core of the synclines from the underlying permeable limestone. for this reason, small springs are in the lower part of the scaglia complex at the head of the agolla valley (fig. 2). one, perennial, is located near the entrance of the gpc, at a high elevation above the local base level, and is fed directly by a stream flowing in the cave. 2.2. modern vegetation the marche region is part of the apenninebalcanic biogeographical province. the most characteristic vegetation series include the hop hornbeam series in the meso-temperate belt, and the low mountain mixed beech woods in the supra-temperate belts (biondi et al. 2010, p. 255). the area around the studied caves shows a typical vegetation of hill-mountain elevations (e.g. biondi et al., 2014). the mountain landscape, located at 800-900 m a.s.l., has a homogeneous and uniform morphology with a soft outline and gentle slopes, in some cases planted with cereals or fodder crops. in the steep side of the mountains facing to the north, at the cave entrances, the vegetation is characterized by a copse wood with predominance of hop hornbeam (ostrya carpinifolia scop.) and south european flowering ash (fraxinus ornus l.). also lindens (tilia platyphyllos scop., t. cordata mill.) and ivy (hedera helix l.) live near the entrance of the cave complex. in the southern side, there is the pubescent oak (quercus pubescens willd.), thermophilous broadleaved that prefers calcareous and marl slope soils and doesn’t tolerate hydro-stagnation. moreover, there are staphylea pinnata l., a rare small tree with vesicle fruits, and daphne laureola l., hepatica nobilis schreb., dactylorhiza maculata (l.) soó, campanula trachelium l. semi-mesophilous pastureland, formed by bromus erectus huds., is especially developed on the top of hillmountain while xeric pasturelands are spread on sunny and partially eroded slopes. on calcareous rocks exposed to the south, there is the holm oak (quercus ilex l.); inside the valley hygrophilous vegetation is present, composed by several species of willows, such as salix purpurea l. and salix alba l., both common along the banks of scarsito creek. 3. the caprelle caves a geological survey inside the cave and in the surroundings, together with the analysis of cave morphologies and deposits, was made to define the conditions of the cave development and history. the existing cave long section (galdenzi, 1983) was revisited and corrected after a detailed survey with a hydraulic digital level. this permitted to verify the absolute altitude of the different cave zones, and to re-drawn the cave map and long section. this revision was necessary to reconsider the old rough magnetic survey (galdenzi, 1983), made with a grade 4 bcra, where the bottom of gc resulted deeper than the permanent stream in gpc. the present hydrologic characteristics of groundwater drainage were monitored in the cave into a more general research on the groundwater hydrology of the whole area, thank to a logger for temperature, level and conductivity that was placed for one year in the perennial stream inside the gpc. an integrated research on the caprelle caves (central italy) ... fig. 3 geologic cross section at the cave entrance. legend: fuc: marne a fucoidi; sb: scaglia bianca; sr1: scaglia rossa, lower part; sr2: scaglia rossa, central part; sr3: scaglia rossa, upper part. 3.1. general characteristics (fig. 4) the caves have different morphologies. both the cave entrances open in the steep slope at the northern margin of the piani di monte lago, below the slope break that divides the upper part of a gentle valley from the actively eroded head of the minor tributaries of the river potenza. the headward erosion in this subsequent valley is the cause of the present opening of the caves to the surface. at 880 m a.s.l., a steep slope cuts the entrance shaft of gc, while at 795 m a.s.l. the gpc entrance opens in the deepest part of the small ravine formed by the stream. gc is ∼200 m long and reaches a depth of 76 m. an upper part consisting mainly of a sequence of shafts (maximum length 17 m) reaches a more complex zone with some sub-horizontal passages at different levels. steeply inclined passages are present throughout the cave. gpc is only a sub-horizontal passage with an average diameter of ~2 m, without lateral branches, and reaching a total length of ∼100 m, while rising ∼10 m higher than the cave entrance. the bottom of gc is close to the termination of the gpc, and the new measurement with a digital level shows that it stays above the stream in the gpc, which is different than in the old maps created with rougher surveys. the expeditious plan of the caves makes uncertain their real horizontal distance, and there are no useful elements to suppose the existence of a practicable direct connection. the general pattern of the cave is strongly influenced by the geological setting (galdenzi, 1983). both caves developed inside a few beds of the scaglia bianca (fig. 2), and the shafts and passages developed along the vertical beds of the limestone. gpc, in particular, strictly follows the core of a meso-anticline. gc, despite its short development, has a complex structure resulting from the combination and superimposition of different types of cave passages. the upper part has mainly vertical development (fig. 5). the entrance shaft and a parallel shaft join in the first cave room, leading to a further descending shaft (p17 in fig. 4). at the bottom of this last true shaft, a small inclined passage leads to the top of a large room where the cave structure changes, assuming a mainly subhorizontal development. some tubes (fig. 5b) are present at different levels; these horizontal passages have no present active hydrological role in the cave, and are intersected by steeply inclined passages or by vertical zones. inclined passages are in both the upper and lower parts of the cave, generally with active seasonal water flows. an ascending branch departs below the entrance shaft, small rising passages are below the p17, a steep descending zone connects the central rooms with the lowest zones, and an ascending passage is in the southern termination of the cave. the present cave morphology in many zones is influenced by breakdown and clast detachment, which can erase the original forms. old corrosion features are preserved in some tubes (fig. 5d) and in small areas of the cave walls and roofs, where they are often mixed 108 galdenzi s. et al. fig. 4 map of the caves, and localization of pollen samples (*). the cave section nne-ssw is projected on a vertical plane along the bedding strike, and the ene-wsw section along the bedding dip. survey: grotta di caprelle galdenzi, 1977-79; galdenzi and cotechini, 2009; grotta piccola di caprelle galdenzi et al., 2008. 109 with more recent physical deposits due to descending water. the running water locally produces active forms of corrosion, and flowstone deposition is actively occurring in the cave, even if the chemical deposits do not generally reach a large diffusion and thickness. gours are forming in the inclined active passages. gpc has a simple structure, consisting of a single sub-horizontal passage, while clast detachment from the roof is the main morphogenetic agent, and the floor is entirely formed by fallen small boulders and cobbles. in the cave, an active deposition of dripstone is scarce or absent due to the lack of seepage water. the detachment process has almost completely destroyed the pre-existing wall features, and only in a few points old erosional and depositional forms are preserved in the cave walls. the two caves have different hydrological behaviours. in gc, a strongly variable flow of vadose water occurs during the year. during the dry periods, a reduced amount of seepage water causes calcite deposition in a large part of the cave, while during the rainy period, and in particular during the snow melt, a diffuse flow of seepage water occurs in the cave. the descending water flows as a sheet on the floor of the inclined an integrated research on the caprelle caves (central italy) ... fig. 5 a) the cave entrance, a shaft in the steep slope cut by the surface erosion (photo by eugenio pistolesi); b) a cave tube in the deep zone of the grotta di caprelle; c) soft mud flowing in the wall due to seepage water, which has an encrusting action on the mud itself; d) old deposits in a pocket in the ceiling, and e) on the cave walls (one pollen sample was taken from this point). passages and creates small streams that partly intersect the main voids. during the wet periods, several temporary pools form mostly in the lower branches of the caves. gpc, on the contrary, is almost totally devoid of dripping water, while a permanent stream flows in the inner part of the cave and feeds the permanent spring that gushes out below the cave entrance. the water flow occurs mainly within the debris in the floor, and in only a few points the water runs directly in the passage. the water discharge is low, and in normal conditions does not exceed a few litre/second of volume flow rate. based on the geologic setting, a direct recharge from the ponors should be excluded, considering that they drain water inside the underlying maiolica in a different syncline. the water characteristics were monitored for one year (september 2006september 2007), thanks to a logger placed in the stream, and the water was sampled bimonthly for its chemistry. the water drainage in the cave was permanent. the measured changes in the water level did not exceed a few centimetres in the stream, but the presence of dry pools with muddy deposits suggests that in periods with more rain the water level can rise inside the bottom debris, reaching the cave floor at a few further points. the cave water has a relatively low 110 galdenzi s. et al. tab.1 pollen samples taken from the caprelle caves. fig. 6 top: conductivity, temperature and water level in the cave, related to precipitations during the monitoring period. bottom: hourly changes of the water conductivity in the cave stream, compared to the water level in the temporary lake of monte lago. 111 salinity (about 210 mg/l) and is mainly bicarbonate, with low sulphate and chloride contents. the water parameters have low seasonal fluctuations: the average temperature and conductivity were 9.6°c and 328 μs/cm (at 20°c) (fig. 6). the lowest conductivity value (312 μs/cm) was measured during a dry period, and the values increased up to 384 μs/cm during the period of high discharge. the water temperature varied with a similar trend between 9.5 and 9.8°c. the stable chemical and physical parameters of the cave water testify to the storage capacity of the aquifer that feeds the spring. the small increase in the water conductivity during the wet season is closely related to the meteoric precipitation (fig. 6). the hydrological data confirm that the water sunk in the mt. lago ponor has not an important role in the recharge of the cave stream, and it is likely fed through diffuse infiltration in the scaglia bianca and scaglia rossa on the karst surface. in fact, the increase in temperature and conductivity in the cave water cannot be due to the direct arrival of cold and low mineralized water from the sinking points. besides, the increase in the conductivity and water level in the stream occurred with a significant delay, compared to the changes that were recorded in the surface stream at the ponor and in the main known resurgence (galdenzi, unpublished data). in addition to widespread clastic materials, dominant in both caves due to the thin bedding and high plicative deformation of the bedrock, different types of physical and chemical deposits are present. they are more abundant in gc, where the depositional processes are still active. only small old deposits were found in the walls of gpc. 3.1.1. gc grotta di caprelle and gpc grotta piccola di caprelle dripstones, flowstones and gours are actively forming in a large part of the grotta di caprelle (gc), even if they only reach a large volume locally. this encrusting action due to seepage water is sometimes associated with a slow flow of a thin layer of soft sediment that covers the wall (fig. 5d). a thin old coating of black sediment, containing fe and mn oxides and hydroxides, locally covers the cave walls. a similar deposit is also present in grotta piccola di caprelle (gpc). sediment deposits containing thin levels of cherty sand are common in the cave, deposited by the descending water that flows inside. some of these deposits are sub-recent but most of them are attributable to ancient depositional events: the latter deposits remain as suspended deposits in the roofs or inside pockets in the walls (fig. 5e). in gpc, the floor is covered by clastic debris fallen down from walls and ceiling. this process is still active and thus unstable. partly detached rock pieces are common in the ceiling. only in a few points there are old deposits preserved in the cave walls, testifying to past moments of the cave evolution. the lack of any recent significant morphogenetic role of the seepage water simplifies their analysis. small amount of old calcite deposits are locally present as dripstones, flowstones and thin wall sheets. the most interesting depositional sequence is preserved in the eastern wall of the central part of the cave (analysed for pollen, see below). the wall shows clean eroded surfaces, without scallops, with notches in the wall and small holes developing along the ceiling fractures. the cave wall and calcite deposits are heavily fractured, with open fissures up to a few centimetres wide caused by the decompression processes responsible for the diffuse clast detachment in the cave. the limestone surface is in large part covered by a thin sheet of crystalline calcite forming small stalactites, deposited by seepage water coming from the surface, and by a thin coating of black sediment which is rich of mn and fe hydroxides. this black sediment underlies the calcite sheet. in gcp, in the lower part of the same wall, small stream deposits, consisting of intra-formational gravel with an abundant sediment matrix, stay on small wall notches. the pebbles are often coated by black sediment, as with the nearby wall. gravel deposition by the stream alternated with the encrusting action due to seepage water, so that the stream deposits are encrusted by calcite, but can also stay above the carbonate sheet in wall notches. this complex relationship is evidence that calcite deposition by the vadose water coeval with the gravel deposition due to the stream, prevailing the one or the other process depending on changes in the hydrological conditions. 3.1.2. chronology several samples were dated with the u/th at the igag-cnr laboratory, at montelibretti, roma (voltaggio, 2010): i) in gcp, a small stalagmite, found at the surface of the ground debris in the cave termination, has a radius of 2 cm and is 6 cm long; the age of core and surface are 92.5±3.4 ka and 48.5±1.3 ka, respectively; ii) in gc, a stalagmite coming from the central zone (point 3 in fig. 4) is asymmetrical and grows directly on a boulder with an interposed, thin and discontinuous layer of detrital material; its length reaches 14 cm and maximum radius of 6 cm, while there is no macroscopic evidence of internal discontinuities; the age in the core of the stalagmite resulted in 48.2±1.7 ka bp, while the surface has an age of 4.1±0.3 ka bp; iii) a thin crust of calcite on the wall of gcp has an age of 28.4±1.2 ka; iv) an iron-manganese black sediment gives an age of 37.6±0.6 ka in gcp (the latter two are described in par. 3.4.2). 4. pollen analysis 4.1. pollen samples nine sediment samples were collected for pollen analysis aiming to study the palaeoenvironmental characteristics during the cave formation. the sampling points were selected to avoid the risk of contamination by modern pollen (tab. 1). in gc, pollen samples were collected between 35 and 60 m from the cave entrance. sample 1 is the nearest to the entrance. samples 2, 3, 4, 5 come from the main sub-horizontal passage below the shafts, in an area containing many old deposits preserved on walls and the ceiling. in particular, sample 2 was collected an integrated research on the caprelle caves (central italy) ... from a notch in the wall and sample 5 in a wall pocket (fig. 5e). the samples 6 a,b,c were close, in a clinostratified deposit below a steep passage, not directly involved in the current flowpath of running vadose water. in gpc, sample 7 was taken at about 70 m from the entrance and was dated at ca. 37.6 ka bp (see above; fig. 4). the samples have been treated for pollen extraction using a concentration method (sieving, and floatation with heavy liquid; for a description see florenzano et al., 2012). the residues were partly mounted in glycerine jelly, and slides were directly observed or permanently sealed with paraffin. all the treated material was analysed. pollen analysis was done by light microscope at 400x, and at 1000x for critical identifications, with the help of atlases (e.g. reille, 1992) and the reference pollen collection. the pollen percentages were calculated on a sum which includes all pollen grains identified (spermatophytes = trees + shrubs + lianas + herbaceous; berglund & ralska-jasiewiczowa, 1986). 4.2. results of pollen analysis (tab. 2; fig. 7) in three samples (4, 6c, 7) a light presence of calcium carbonate resulting from the alkaline substratum did not allowed sufficient pollen preservation. therefore, only the row number of counted pollen grains (sum < 40) is reported in tab. 2. in the other six samples (1, 2, 3, 5, 6a, 6b) pollen preservation was good, but the amount of pollen was so low in each slides that the analyses were timeconsuming. a mean count of about 190 pollen grains per sample was attained. although the preservation of most pollen grains was good, it is probable that some loss of pollen occurred (berglund & ralskajasiewiczowa, 1986; horowitz, 1992). this is supported by the presence of high amount of cichorieae in all samples (sensu florenzano et al. 2014; 10% on average). the cichorieae pollen has very resistant exine that survives even when some selective corrosion destroyed the thin pollen grains (e.g. cupressaceae). the mean pollen concentration was about 450 pollen grains/g (p/g). although this value is very low, it may be considered relatively high compared with the low concentrations found in other cave deposits of central italy (e.g. 242 p/g were observed in grotta di valle delle vacche, abruzzo; loreti & mercuri, 2007). as a whole a list of 56 taxa (21 of woody plants, and 35 of herbaceous plants) was compiled. the sum of woody plant percentages resulted 20-40% in samples 1,2,3,5, and about 70% in samples 6a,6b. among conifers, pinus subgen. strobus, p. subgen. pinus (they correspond to haploxylon and diploxylon pine pollen types, respectively: fralish & franklin, 2002, p. 59) were found with abies, picea and cupressus. among broadleaved trees, there were alnus, betula, fraxinus ornus type, salix, tilia. also few deciduous quercus, castanea and erica were identified. in total, there are low values of oak wood (2% on average). asteraceae including artemisia (2%), ambrosia, aster, centaurea, crepis cf., cichorieae, asteroideae undifferentiated (17%) and poaceae (12%), with cyperaceae (3%), were predominant in the herb taxa. 4.3. pollen supply into the cave cave deposits are known to be generally poorly preservative for pollen because alkaline or oxidised substrata are common and may destroy exine, the external pollen wall (navarro camacho et al., 2000, 2001; mcgarry & caseldine, 2004). however recent research of terrestrial carbonates from central italy documented that the ph of the solutions from which travertine or tufa precipitate is not a limiting factor in causing corrosion and/or destruction of pollen grains (bertini et al., 2014). moreover, pollen sources (i.e., plants) grow outside the cave and therefore the amount of pollen in sediments largely depends on the cave morphology. pollen could enter the caves by: 1) air from the entrances; caves could have only one break with limited exposure to the air or, differently, many openings with air flow entrance. any supply of pollen circulating in the atmosphere is obviously poorer into the cave, particularly in deepest sectors and away from the entrance, than in open spaces; 2) water, by seepage or underground flow; 3) animals, by paws, fur, body or excrements (garofalo et al., 2009). pollen already included in sediments can enter the cave by water or animals transporting the sediments. in these study, the presence of pollen into the caves is a good evidence that some organic material arrived from outside into the caves. considering that gc has mainly a vertical structure, and pollen samples were collected deep inside the caves, the pollen was probably transported by water, the carrier that may have equally filled the underground sectors of these caves. pollen of oak and other elements typical of mixed oak woods have low values in the studied pollen spectra, and this may be due to different reasons: considering the known high productivity of oaks this may be a further evidence that wind-transport inside the caves was low, or/and that in the nearby of this cave a mixed oak woodland was absent at the time of deposit formations. 4.4. palaeoenvironmental inferences pollen spectra are prevalently characterized by a low percentage of trees/shrubs and by a prevalence of pollen produced by plants growing in grassland or steppe vegetation. as a general remark, woodlands seem to have always been at a certain distance from the water flooding pathways, or from the opening of the cave itself. another possibility is that mesophilous elements were quite rare as in other central italian regions (follieri et al., 1998; magri 1999; magri and sadori 1999; chiarini et al., 2007; giardini, 2007). pinus and artemisia, which are, during the latest quaternary, the main makers of glacial phases with cold climate and steppe vegetation, are ubiquitous in these spectra as well as poaceae and other asteraceae. however they are always accompanied by low values of deciduous quercus and other broadleaved trees suggesting that these spectra do not belong to full glacial phases or that the temperature was probably not too cold or that the humidity was enough even during glacial phases. actually, thermophilous and mesophilous plants are known to have survived in refugia also during the acme peak of the glacials in italy (follieri et al., 1988, 112 galdenzi s. et al. 113 1998; magri, 1989, 1999; allen & huntley, 2000; watts et al., 2000; follieri & magri, 2001; tzedakis et al., 2001; yll et al., 2006; bertini, 2010; facenna et al., 2008; pini et al. 2010; moreno et al., 2014). in samples 1, 2, 3, 5 pollen diversity ranges from 26 to 36 taxa per sample. the woodland cover is always < 40% and includes pinus subgen. pinus (almost one third of p. subgen. strobus), and several deciduous trees (quercus, betula, fraxinus cf. excelsior, tilia; tab. 2). conifer woods were probably distributed on mountains, sometimes mixed to deciduous trees as betula, tilia and castanea while mixed oak woods were probably more distributed on the hilly belts. hedera was part of the broadleaved woodlands while alnus and salix, the latter especially well represented, are evidence of the hygrophilous woodland that was distributed along river shores. spectra show evidence of wet grassland (poaceae, cyperaceae), and xerophilous associations with chenopodiaceae, cichorieae and artemisia; other asteroideae, brassicaceae, caryophyllaceae, helianthemum, rosaceae may be part of shrubby grassland vegetation. only samples 6a and 6b show a higher value of arboreal pollen sum (ca. 70% on average) mainly due to the predominance of pinus (here subgen. pinus is double than the subgen. strobus), and to relatively high amount of quercus types. it is noteworthy that in these two samples, there are the only evidences of quercus cf. cerris, cupressus and ulmus; picea has the highest values while abies, betula and tilia are absent. there are several signs of aridity: hygrophilous trees are low and represented only in sample no. 6b; among herbs, cyperaceae and nymphaea are absent. actually, these two samples show the lower pollen diversity (number of taxa = 15, 21) and describe a more forested, cold and dry environment with respect to the above-described samples. altogether, pollen spectra are concordant with the geochronological context of the caves (see above par. 3.1.2). they are in agreement with data from glacial phases within the interval 37-28 ka bp in italy, as studied at lagaccione (magri, 1999), valle di castiglione (follieri et al., 1988; magri, 1989; follieri & magri, 2001), vico (magri and sadori, 1999), stracciacappa (giardini, 2007), corvaro (chiarini et al., 2007), lago grande di monticchio (allen & huntley, 2000; watts et al., 2000) and lago di fimon (pini et al. 2010). interestingly, the samples may be attributed to a colder and drier phase (samples 6a, 6b) and to a relatively warmer and wetter phase (samples 1, 2, 3, 5). although the distribution of an integrated research on the caprelle caves (central italy) ... fig. 7 pollen grains from the mud samples of caprelle caves: 1) alnus (29 µm); 2) helianthemum (30 µm); 3) poaceae (40 µm); 4) plantago media type (23 µm); 5) deciduous quercus (29 µm); 6) fraxinus ornus type (24 µm); 7) artemisia (24 µm); 8) picea (110 µm); 9) ulmus (29 µm); 10) ostrya (26 µm); 11) tilia (43 µm); 12) pinus subgen pinus (75 µm) (photos by mara loreti). tab.2 pollen data from the caprelle caves; percentages are calculated on the total pollen grains that were found in each sample. the grey columns are semi-sterile samples (pollen counts are reported as row numer of grains found). 114 galdenzi s. et al. 115 samples could have also been partly responsible for the different relevance of some taxa in these spectra, we think that the hard conditions of deposition and the very low amount of pollen that has reached these underground deposits may give some confidence to this interpretation. the presence of different ‘degree of cold’ in samples that were deposited during a relatively short glacial interval is well compatible with the known phases of mis3 (van meerbeeck et al., 2009). 5. the cave development the caves history is long, as documented by the co-existence and superimposition of different morphologies. the geological structure and, in particular, the setting of the folds involving the underlying lowpermeable marne a fucoidi, influenced the drainage pattern throughout the cave history. the water recharge, based on the results of the hydrological monitoring and hydrogeological setting, can be attributed mainly to diffuse infiltration on the karst surface, while the contribution from sinking points in piani di monte lago, if existing, had a minor importance, in the past and in the present. in the caves, no direct evidence of the first speleogenetic phases is preserved. it can be hypothesized that the flow of water inside the limestone produced a progressive widening of the fissures, increasing the permeability and the possibility of the infiltration of water in the vadose zone. the flow of vadose water was influenced by the vertical dip of the limestone, which facilitated the descent towards the depth along the bedding planes. in the phreatic zone, the underlying marl formation maintained the drainage of the water parallel to the bedding, towards the emergence, creating the sub-horizontal passages existing in the lower parts of the caves. the high elevation of the cave passages in the mountain is not due to permeability changes inside the rock mass. instead, it is probable that these passages formed at the same elevation of the old local base level during the first phases of the cave evolution, before the valleys deepened to the present situation. the distribution of these cave passages on many levels, none of them well developed, could be related to a progressive lowering of the emergence point. the limestone dissolution also produced an increase in the permeability of the vadose zone, well testified by the present fast drainage of infiltration water. inside the cave, this flow caused the development of some shafts and inclined passages that are still in active evolution, alternating depositional and corrosion actions. at the surface, the increase in the permeability caused the total disappearance of water circulation. the permanent water flow in gpc and the stability of the chemical and physical parameters throughout the year testify to the storage capacity of the limestone. the great difference in elevation between the spring and the present local base level is probably related to a diminution of the permeability in the limestone. it implies that the karst solution has not yet acted significantly in the deep zones of the aquifer, maintaining the drainage setting which existed before the headward erosion in the agolla valley reached the cave area. the wide dimensions of the cave voids and the high elevation of the sub-horizontal passages above the present local base level suggest that the cave formation is likely to have begun before the rivers cut the present deep valleys inside the pre-existing erosion surface. as this event is generally referred to the end of the early pleistocene, it is likely that the first phases of cave development occurred during that period. despite pollen is an interesting presence in these caves, the chronology of the samples is fairly uncertain because the deposition of sediment is a long-time event, which continued until recent times. although the problem cannot be resolved for all the contexts, the depositional features of gpc and some characters of the pollen data can help us to infer the most probable chronology for the samples that were taken for pollen analyses. in fact, we observed that pollen preservation looks similar, and the list of taxa was fairly coherent in all the samples suggesting that the same original sediment entered many parts of the caves. if one/few rapid deposition event/s can be argued, some inferential reasoning may help to define the chronology of pollen samples: a) the deposition of black sediment took place in a relatively short time, and the studied deposits were substantially of the same age; b) the black sediment in gcp corresponding to sample no.7 was dated to 37.6 ka bp; c) here, as in other spots, the sediment was deposited under concretions dated to 28.4±1.2 ka. this means that most of the sediment was deposited into the caves between about 37.6 and 28.4 ka bp. pollen samples, therefore, are expected to belong to a period corresponding to the marine isotope stage 3 (mis 3), recorded between 60 and 27 ka ago, during the last glacial cycle that experienced several abrupt climatic oscillations (follieri et al., 1996; van meerbeek et al. 2009): warming phases known as dansgaard-oeschger events alternated to cold phases such as the so-called heinrich events (e.g. labeyrie et al., 2013 and references therein). in the late pleistocene, the cave had already reached shape and morphology similar to the present one, as testified by the age of calcite deposits in the cave passages, up to 92.5 ka bp. during the same period, the infiltrating water carried a significant amount of sediment, with a minor sandy content, which deposited in the cave zones not directly involved in the flow of water. this depositional phase, based on the geochronological and pollen data, should have occurred during the cold phases of the late pleistocene, most probably during the mis3 oscillations, when steppe and grassland prevailed at the surface and woodland cover was poor. at the end of this period, before the last glacial maximum, calcite deposition probably prevailed on the sediment deposition, as shown by the depositional relationship between the sediment and calcite on the walls in the gpc. the deposition of a similar calcite sheet is also common in other caves of the area, and in the pozzo di fonte fragola it was u/th dated to 31.3±1.5 ka (galdenzi, 1996). after this event, the caves evolved mainly from the erosion and corrosion actions of the infiltration water. the encrusting action of the water reduced, and a large an integrated research on the caprelle caves (central italy) ... part of the old calcite sheets were corroded and partly destroyed, as verified also in other caves in the same area. 6. conclusions the multidisciplinary research in the caprelle caves has permitted a more complete and detailed comprehension of the conditions and processes that influenced the history of the caves, providing, at the same time, interesting information on the environmental setting. the caves pattern is strongly influenced by the geologic setting in the limb of a minor anticline, where the vertical beds and the underlying marl deposits guided drainage both for the infiltration water in the vadose zone and the horizontal flow to the emergence. in the cave, the sub-horizontal passages located at different altitude testify to the progressive lowering of the drainage inside the limestone. the emergence, however, is ∼200 m higher than the presence local base level, probably due to a decrease of karstification degree in the deep zones of the aquifer. the cave deposits dated back to 92.5 ka and the pollen content in the cave sediments suggest that the caves had already reached the present setting and dimension in the upper pleistocene. for these reasons, it is probable that the cave enlargement began before the deepening of the hydrographic surface, an event that is in general referred to the end of early pleistocene. the pollen spectra from all samples were probably fairly coeval. grasslands and steppe, typical of glacial phases, characterized the palaeoenvironment. the chronological elements available for the caves suggest that the arid and probably cold period recorded between 37 and 28 ka bp was characterized by conifer woods with pine, fir and spruce, accompanied by significant broadleaved trees such as oaks, birch, ash, linden and chestnut. acknowledgements dating of speleothems and preliminary pollen analysis were done in the project "l'area carsica di monte lago e le grotte di caprelle", developed by gruppo grotte recanati, g.s. cai macerata c. r. s. “nottoloni” macerata, g.a.sp. civitanova marche g.s. al.va.p. pioraco cai camerino. this project, coordinated by alfredo campagnoli† and giulio cotechini was financed by regione marche in range of intervention for speleology (l. r. 12/2000). authors thanks: gruppo speleologico al.va.p. pioraco cai of camerino and, particularly, giulio cotechini, silvano piazzoli, roberto correnti and federica cotechini, about the contribution to sampling operations; giulio cotechini and geol. eugenio pistolesi, who took part to speleology cartography review; prof. pietro paolo pierantoni, università degli studi di camerino scuola di scienze e tecnologia, sezione geologia. prof. piero farabollini università degli studi di camerino scuola di scienze e tecnologia, sezione geografia fisica e geomorfologia; prof. carlo renieri, director of scuola di scienze ambientali dell’università degli studi di camerino. thanks to dott.ssa roberta tacchi, curatore dell’orto botanico “carmela cortini” about her availability to use the microscope for examination and taking pictures of pollen particles. we are indebted to the two referees who greatly improved the clarity of the paper with their comments. references allen j.r.m., huntley b. (2000) weichseilan palynological records from southern europe: correlation and chronology. quatern intern 73/74, 111125. ambrosetti p., carraro f., deiana g., dramis f. (1982) il sollevamento dell'italia centrale tra il pleistocene inferiore e il pleistocene medio. c.n.r., p.f. “geodinamica”, pubbl. 513, p ii, 219-223. bartolini c., d’agostino n., dramis f. (2003) topography, exhumation, and drainage network evolution of the apennines. episodes, 23 (3), 212-217. berglund b.e., ralska-jasiewiczowa m. (1986) pollen analysis and pollen diagrams. in, berglund b.e. (ed.) handbook of holocene paleoecology and palaeohydrology. chichester, 455-484. bertini a. (2010) pliocene-pleistocene palynoflora and vegetation in italy: state of the art. quatern int, 225, 5-24. bertini a., minissale a., ricci m. (2014) palynological approach in upper quaternary terrestrial carbonates of central italy: anything but a ‘mission impossible. sedimentology, 61, 200-220. biondi e., casavecchia s., pesaresi s. (2012) nitrophilous and ruderal species as indicators of climate change. case study from the italian adriatic coast, plant biosyst, 146, 134-142. biondi e., allegrezza m., casavecchia s., galdenzi d., gasparri r., pesaresi s., vagge i., blasi c. (2014) new and validated syntaxa for the checklist of italian vegetation, plant biosyst, 148, 318-332. calamita f., pierantoni p.p. (1993) il sovrascorrimento di m. cavallo-m. primo (appennino umbromarchigiano). boll. soc. geol. it., 112, 825-835. ciccacci s., d'alessandro l., dramis f., fredi p., pambianchi g. (1985) geomorphological and neotectonic evolution of the umbria-marche ridge, northern sector. studi geologici camerti 10, 7-15. chiarini e., giardini m., la posta e., papasodaro f., sadori l., (2007) sedimentology, palynology and new geochronological constraints on quaternary deposits of the corvaro intermontane basin (central italy). rev micropaléont 50, 309-314. d’agostino n., dramis f., funiciello r., jackson j.a. (2001) interactions between mantle upwelling, drainage evolution and active normal faulting: an example from the central apennines (italy). geophys j int 147, 475-497. de waele, j., galdenzi, s., madonia, g., menichetti, m., parise, m., piccini, l., et al. (2014). a review on hypogene caves in italy. special publication 18, selected papers and abstracts (february 2-7), 2014, san salvador island, bahamas, 28-30. facenna c., soligo m., billi a., filippis l., funiciello r., rossetti c., tuccimei p. (2008) late pleistocene depositional cycles of the lapis tiburtinus tra 116 galdenzi s. et al. 117 vertine (tivoli, central italy): possible influence of climate and fault activity. global planet change 63, 299-308. falaschi p.l. (1987) la signoria di giulio cesare da varano, in camilla battista da varano e il suo tempo. atti del convegno di studi sul v centenario del monastero delle clarisse di camerino (camerino 7-9 settembre 1984). camerino, 31. florenzano a., mercuri a.m., pederzoli a., torri p., bosi g., olmi l., rinaldi r., bandini mazzanti m. (2012) the significance of intestinal parasite remains in pollen samples from mediaeval pits in the piazza garibaldi of parma, emilia romagna, northern italy. geoarchaeology 27, 34-47. florenzano a., marignani m., rosati l., fascetti s., mercuri a.m. (2014) are cichorieae an indicator of open habitats and pastoralism in current and past vegetation studies? plant biosyst. 10.1080/11263504.2014.998311 follieri m., magri d. (2001) middle and upper pleistocene natural environment in the roman area: climate, vegetation and landscape. the world of elephants. international congress, rome. follieri m., magri d., sadori l. (1988) 250,000-year pollen record from valle di castiglione (roma). pollen spores 30, 329-356. fralish j.s., franklin s.b. (2002) taxonomy and ecology of woody plants in north american forests (excluding mexico and subtropical florida). john wiley & sons. galdenzi s. (1983) geomorfologia delle grotte di caprelle. in: atti xiv congresso nazionale di speleologia, bologna 1982. gr. it. xi, 443-452. galdenzi s. (1988) il carsismo nei calcari pelagici dell'appennino umbro marchigiano: il ruolo degli orizzonti impermeabili nella canalizzazione sotterranea in una catena a pieghe. in: actes xiv cong. nat. speleol. (nancy-metz, 1985). spelunca memories, 14, 143-146. galdenzi s. (1996) il carsismo profondo nell'appennino umbro marchigiano (italia). proceedings international congress "alpine caves: alpine karst systems and their environmental context", asiago, 11-14 june 1992, 229-242. galdenzi s., paggi s., pistolesi e., cotechini g. (2008) grotte e carsismo nel territorio di sefro. in: di martino v., pedrotti f. & valeriani p. (eds.). atti conv., “per l'istituzione del parco naturale regionale dell'area monte pennino, vallescurosa e monte lago”. sefro, 2006. garofalo p.s., matias b., fricker m., gunther d., forti p., mercuri a.m., loreti m., lauritzen s.e., constantin s., capaccioni b. (2009) climatic control on the growth of gigantic gypsum crystals within hypogenic caves (naica mine, mexico), epsl 289, 560-569. giardini m. (2007) late quaternary vegetation history at stracciacappa (rome, central italy). veg hist archaeobot 16, 301-316. horowitz a. (1992) palynology of arid lands. amsterdam, elsevier. labeyrie l., skinner l. c., cortijo, e. (2013) submilankovitch (do/heinrich) events. in: encyclopaedia of quaternary science. elsevier, amsterdam, 200-208 loreti m., mercuri a.m. (2007) la ricostruzione del paleoambiente attorno alla grotta delle vacche: parco naz. d’abruzzo, lazio e molise: un’ipotesi su base speleopalinologica. in: loreti m. e salerno p. (a cura di). “una cavità dalle mille sorprese: grotta delle vacche parco nazionale d’ abruzzo, lazio e molise”. arduino sacco editore, bella (pz), 43-67. magri d. (1989) interpreting long-term exponential growth of plant populations in a 250,000 year pollen record from valle di castiglione. new phytol, 112, 123-128. magri d. (1999) late quaternary vegetation history at lagaccione near lago di bolsena (central italy). rev palaeobot palynol, 106, 171-208. magri d., sadori l. (1999) late pleistocene and holocene pollen stratigraphy at lago di vico (central italy). veg hist archaeobot, 8, 247-260. mcgarry s.f., caseldine c. (2004) speleothem palynology: an undervalued tool in quaternary studies. quatern sci rev, 23 (23-24), 2389-2404. minetti a., nanni t., perilli f., polonara l., principi m. (eds.) (1991) l'ambiente fisico delle marche, regione marche, giunta regionale, s.el.ca, firenze. moreno a., svensson a., brooks s. j., connor s., engels s., fletcher w., genty d., heiri o., labuhn i., persoiu a., peyron o., sadori l., valero-garces b., wulf s., zanchetta g. and data contributors (2014) a compilation of western european terrestrial records 60-8 ka bp: towards an understanding of latitudinal climatic gradients. quatern sci rev, doi: 10.1016/j.quascirev.2014.06.030. navarro c., carrion j.s., navarro j., munuera m. (2000) an experimental approach to the palynology of cave deposits, j quatern sci, 15, 603-619. navarro c., carrion j.s., munuera m., prieto a.r. (2001) cave surface pollen and the palynological potential of karstic cave sediments in palaeoecology. rev palaeobot palyno, 117, 245-265. pini r., ravazzi c., reimer p.j. (2010) the vegetation and climate history of the last glacial cycle in a new pollen record from lake fimon (southern alpine foreland, n-italy). quatern sci rev, 29, 3115-3137. reille m. (1992) pollen et spores d’europe et d’afrique du nord. laboratoire de botanique historique et palynologie , cnrs, marseille, france. tzedakis p.c., andrieu j.v.l., de beaulieu h.j.b., birks d., crowhurste s., follieri m., hooghiemstra h., magri d., reille m., sadori l., shacklrton n. j., wijmstra t. a. (2001) establishing a terrestrial chronological framework as a basis for biostratigraphical comparisons. quatern sci rev, 20, 1583 -1592. voltaggio m. (2010) relazione riguardante i campioni esaminati per spettrometria di massa provenienti dalla località piani di monte lago. unpublished igag report to gruppo grotte recanati. watts w. a., allen j.r.m., huntley b. (2000) paleocology of three interstadial events during oxygen an integrated research on the caprelle caves (central italy) ... isotope stages 3 and 4: a lacustrine record from lago grande di monticchio, southern italy. palaeogeogr palaeoclimatol, 155, 83-93. yll r., carrion j.s., marra a.c., bonfiglio l. (2006) vegetation reconstruction on the basis of pollen in late pleistocene hyena coprolites from san teodoro cave (sicily, italy). palaeogeogr palaeoclimatol palaeoecol, 237, 32-39. van meerbeeck, renssen h., roche d.m. (2009) how did marine isotope stage 3 and last glacial maximum climates differ? perspectives from equilibrium simulations. clim. past, 5, 33-51. 118 galdenzi s. et al. ms. received: june 19, 2014 final text received: december 18, 2014 base geomorfologia strutturale e domini di frattura dei fondali marini pericostieri dell’isola di procida (campi flegrei insulari, italia meridionale) maria luisa putignano & marcello schiattarella dipartimento di scienze geologiche, università della basilicata, potenza corresponding author: m. schiattarella <marcello.schiattarella@unibas.it> riassunto: putignano m.l. & schiattarella m., geomorfologia strutturale e domini di frattura dei fondali marini pericostieri dell’isola di procida (campi flegrei insulari, italia meridionale). (it issn 0394-3356, 2010) i fondali marini che orlano l’isola di procida nel golfo di napoli sono stati oggetto di uno studio morfostrutturale basato sull’investigazione diretta, fino alla profondità di circa 30 m, e sulla interpretazione di profili sismici ed ecografici che hanno portato alla redazione di una carta geomorfologica. sono stati in tal modo cartografati depositi, superfici erosionali e morfolineamenti di origine tettonica che hanno contribuito a definire il quadro morfoevolutivo della fascia pericostiera procidana. la buona corrispondenza tra il sistema di frattura rilevato sull’isola e ai campi flegrei con il pattern dei morfolineamenti sottomarini induce a ritenere non dissimile la storia strutturale tardo-quaternaria di queste aree. in aggiunta a ciò, la definizione di diversi paleolivelli di base dell’erosione consente di dettagliare meglio l’interazione tra oscillazione eustatica e sollevamento o subsidenza indotti da vulcanesimo e tettonica. in particolare, l’attribuzione cronologica dei prodotti vulcanici recenti e le loro relazioni morfostratigrafiche con le superfici di abrasione sommerse hanno permesso di discriminare le tappe morfoevolutive dell’area di studio. abstract: putignano m.l. & schiattarella m., structural geomorphology and fracture system of the pericoastal sea floor of the procida island (insular phlegraean fields, southern italy). (it issn 0394-3356, 2010) sea floors surrounding procida island in the bay of naples have been studied from a morpho-structural point of view. such a study has been based on both direct survey of the submarine environment (up to the depth of 30 m) and seismic lines and echographic data interpretation, and allowed us to realize an accurate geomorphological map of the pericoastal areas. marine recent deposits, tectonic morpho-lineaments, submarine erosional terraces, submerged notches and other submerged sea level markers have been mapped, so contributing to define the holocene morpho-evolutionary picture of the phlegraean offshore. the good fit between the submarine fracture system and the inland fault and fracture pattern suggests that the investigated coastal marine areas underwent the same latequaternary structural history of the nearby continental region. in addition, the recognition of several base-palaeolevels of the erosion allows to better define the interplay among sea-level changes, tectonics, and volcanogenic vertical movements. archaeological data, ages of the volcanic products, their morpho-stratigraphic relationships with the submarine erosional terraces and other geomorphological constraints permit now a suitable chronological attribution to the different orders of land surfaces, making more reliable the calculation of the subsidence rates and helping the comprehension of the morpho-evolutionary trend of the study area. the planimetric geometry of the strain field has been achieved by both submarine survey and morphostructural analysis: it clearly shows en echelon style, consisting of three dimensionally similar fault-bounded sectors (canale di procida, isola di procida p.p. and promontorio di solchiaro isola di vivara canale di ischia). from a physiographic viewpoint, such sectors result separated by e-o to n120°-striking faults producing an apparent dextral offset. it is likely that they may represent transfer structures due to extensional deformation by nne-sso-striking master faults and, therefore, featured by a “passive” left-lateral slip. the fault set displacing the neapolitan yellow tuff in the capo posillipo area and absent in the procida island area is n50-60° oriented. such a trend also characterizes joint sets affecting submarine outcrops associated to hydrothermal phenomena. then, one can conclude that this trend represent very recent structures, cut only by erosional surfaces located at a depth of 14/-15 m and attributed to the middle bronze age. the subsidence rate calculated for five different orders of submarine erosional surfaces is apparently constant, showing always values around 4-5 mm/y and so suggesting a regular evolution trough the time of the studied pericoastal system, characterized by the submersion of portions of coastal sectors by continuous and invariable volcano-tectonic subsidence. yet, using the post-holocene sealevel rising curve to set the eustatic correction, it is possible to obtain a more articulated picture of the morpho-evolutive sequence, characterized by alternating periods of different subsidence rates. this scenario seems to be more realistic in an area of complex interplay between tectonics and sea-level changes such as the phlegraean fields. parole chiave: geomorfologia strutturale, geologia dell’olocene, domini di frattura, superfici di abrasione marina, campi flegrei insulari (italia). keywords: structural geomorphology, holocene geology, fracture system, submarine erosional terraces, insular phlegraean fields (italy). il quaternario italian journal of quaternary sciences 23(2bis), 2010 volume speciale 229-242 introduzione e inquadramento tettonico la diffusione crescente della pratica del rilievo geomorfologico subacqueo e della consapevolezza che le fasce di giunzione tra la terraferma ed i bacini marini rappresentano delle aree di particolare fragilità ambientale ma anche delle preziose fonti di dati poco valorizzati ha stimolato l’interesse scientifico di chi scrive verso lo studio morfostrutturale delle zone pericostiere che orlano le isole di procida e vivara e fronteggiano le coste dei promontori di monte di procida capo miseno e di capo posillipo nisida (fig. 1). si tratta di un’area complessivamente ben studiata per quanto attiene alle zone emerse ma scarsamente conosciuta nei suoi aspetti geologici e geomorfologici della fascia costiera sommersa. sacchi et al. (2009) hanno recentemente pubblicato diversi profili sismici interpretati riguardanti l’offshore napoletano, in parte utilizzati in 230 m.l. putignano & m. schiattarella questo lavoro per la verifica del posizionamento di alcune strutture (faglie e fratture) dedotte da rilievi diretti e analisi morfobatimetriche. per tale scopo sono stati inoltre utilizzati i profili sismici (acquisizione sparker monocanale ad alta risoluzione) resi disponibili durante i lavori del progetto carg campania (foglio 465 isola di procida). va ancora ricordato che il territorio flegreo costituisce un’area di particolare rischio geologico, poiché affetta da fenomeni sismici e vulcanici accompagnati da deformazione del suolo, che spesso stimolano fenomeni gravitativi pellicolari in ambiente continentale (beneduce et al., 1988), o più complessi, a sviluppo sia subaereo che sottomarino (chiocci & de alteriis, 2006). l’area dei campi flegrei e delle isole adiacenti (procida e ischia) è localizzata lungo il margine tirrenico tra la latitudine 40° e 41° n. tale margine è impostato su litosfera continentale assottigliata, che rappresenta la transizione verso l’area più propriamente oceanica, coincidente con la piana batiale del tirreno centrale (piane del marsilii e del vavilov), poste a più di 3000 m di profondità (de alteri is et al., 2006). i l mar tirreno è un bacino estensionale neogenico formatosi almeno parzialmente durante la strutturazione della catena appenninica, accompagnando la rotazione antioraria della penisola italiana (channel & tarling, 1975; malinverno & ryan, 1986; kastens & mascle, 1988; patacca et al., 1990; nicolosi et al ., 2006). le faglie normali orientate secondo gli andamenti n-s e nno-sse hanno caratterizzato le fasi estensionali iniziali dal tortoniano al pliocene, mentre quelle con direzione no-se, ne-so e e-o hanno interessato il margine tirrenico durante tempi plio-quaternari (bartole et al., 1984; trincardi & zitellini, 1987; doglioni, 1991). più autori riconoscono che le prime due famiglie sono prevalenti nella strutturazione dei bacini sedimentari peritirrenici, pur fornendo diverse interpretazioni cinematiche (fabbri et al., 1981; mariani & prato, 1988; ortolani et al., 1992; cinque et al., 1997; milia & torrente, 1999; acocella & funiciello, 1999; bruno et al., 2002). durante il quaternario il margine tirrenico campano viene strutturato da faglie dirette ad andamento no-se e ne-so, che hanno determinato settori in forte subsidenza. è il caso dell’ampia depressione della piana campana, delimitata a nordovest dall’alto morfostrutturale del monte massico e a sud-est dai monti lattari, che costituiscono l’ossatura della penisola sorrentina. all’interno della piana, e segnatamente lungo la fascia costiera, si individuano le morfostrutture vulcaniche del complesso del sommavesuvio e dei campi flegrei, un distretto policraterico articolato in un’area continentale ed in una insulare, corrispondente alle isole di ischia e di procida-vivara (fig. 1). il vulcanismo continentale e insulare dei campi flegrei risulta impostato su un alto strutturale (di girolamo et al., 1984; bruno et al, 2002), i cui bassi adiacenti sono rappresentati dal golfo di napoli e dalla piana del volturno. tale horst continua in terraferma con andamento antiappenninico fino alle aree più settentrionali della piana campana in territorio casertano (finetti & morelli, 1974; di girolamo et al., 1984). il golfo di napoli è attraversato dalla faglia campi flegrei ischia (de alteriis & toscano, 2003) e dalla fig. 1 ubicazione dell’area di studio nel quadro morfostrutturale del golfo di napoli e in quello geologico della piana campana. b.n.: banco di nisida, b.p.: banco di pentapalummo, b.m.: banco di miseno, b.g.: banco gaia, b.i.: banco di ischia, b.f.: banco di fuori. location map of the study area in the morpho-structural frame of the bay of naples. b.n.: nisida bank, b.p.: pentapalummo bank, b.m.: miseno bank, b.g.: gaia bank, b.i.: ischia bank, b.f.: fuori bank. faglia del dhorn (milia & torrente, 1999), ed è confinato a sud dalla faglia capri penisola sorrentina (sacchi et al., 1994). in corrispondenza di queste faglie si osservano significativi rigetti delle successioni meso-cenozoiche che rappresentano il basamento acustico. tra le sintesi a carattere geo-strutturale sull’evoluzione tettono-stratigrafica del golfo di napoli sono da ricordare gli scritti di mariani & prato (1988), sacchi et al. (1994), ferranti et al. (1996) e milia & torrente (1999; 2007). le strutture estensionali pleistoceniche che hanno interessato il golfo di napoli sono costituite da famiglie di faglie ad andamento appenninico, antiappenninico ed e-o, la cui cronologia relativa permette di delineare la seguente storia deformativa (milia & torrente, 1999; 2007): un primo evento tettonico, responsabile della formazione del golfo di napoli, si è esplicato durante il pleistocene inferiore con sistemi di faglie dirette ad andamento no-se; il secondo evento tettonico, di età compresa tra il pleistocene inferiore ed il pleistocene medio, ha prodotto strutture asimmetriche di tipo halfgraben con asse antiappenninico, che caratterizzano tutto il margine campano, in accordo con quanto già descritto da mariani & prato (1988) e da sacchi et al. (1994); faglie di nuova formazione, o che riprendono lineamenti precedenti, sono attive alla f ine del quaternario e mostrano ancora orientazioni no-se, ne-so ed e-o (post-ignimbrite campana auctt.). queste sono responsabili dell’attuale assetto strutturale del golfo di napoli ed interessano anche le vulcaniti flegree (beneduce & schiattarella, 1989-1990). i depositi sedimentari alluvionali, marini e transizionali quaternari della piana campana, con frequenti intercalazioni di prodotti vulcanici, hanno spessori notevoli (fino a oltre 3000 m; cfr. ippolito et al., 1973). il cuneo sedimentario prosegue a mare con uno spessore di almeno 2 km nel centro del golfo di napoli (fusi et al., 1991; aiello et al., 1997; milia, 1999; marsella et al., 2001). le piane alluvionali attuali si raccordano alla piattaforma continentale tramite i complessi di foce dei fiumi sarno e sebeto nel golfo di napoli e del volturno nel golfo di gaeta. 2. caratteri geologici e geomorfologici delle isole di procida e vivara le isole vulcaniche di vivara e procida sono state generate da più eruzioni che hanno originato un campo policraterico. i prodotti più antichi sono rappresentati dai tufi degli apparati vulcanici di vivara e di pozzo vecchio e terra murata (in procida), la cui età è ancora indeterminata. de astis et al. (2004) propongono un’età di circa 70 ka per l’inizio dell’attività vulcanica procidana, mentre al successivo vulcano di fiumicello viene attribuita un’età compresa tra 60 e 75 ka (fedele et al., 2010). l’ultimo evento eruttivo (vulcano di solchiaro) è datato a 19 ka (alessio et al., 1976) oppure a 17 ka (lirer et al., 1991). tutti questi apparati sono ascrivibili a tipologie morfologiche di tipo tuff cone. altri prodotti, legati ad eruzioni dei vulcani limitrofi dell’isola di ischia, del canale di ischia e della porzione continentale dei campi flegrei (di girolamo et al., 1984), drappeggiano le unità di raffreddamento messe in posto localmente. gli eventi eruttivi hanno generato collassi vulcano-tettonici nell’area, peraltro affetta da diverse famiglie 231geomorfologia strutturale e domini di frattura dei fondali ... di faglie e fratture, responsabili dello smembramento delle strutture originarie. tali fenomeni si sono innescati sin dall’inizio della costruzione dei primi apparati vulcanici (di girolamo & stanzione, 1973; aiello et al., 2007) e hanno portato più volte in ambiente marino settori prima emersi. a testimonianza di ciò, depositi marini e/o transizionali si ritrovano intercalati ai depositi vulcanici antichi lungo le falesie dell’isola di procida, associati talora a tracce di solchi di battigia (aiello et al., 2007). lungo le stesse falesie si ritrovano anche piccoli lembi relitti terrazzati, talvolta con caratteri di superfici di abrasione marina. le ricostruzioni degli eventi morfoevolutivi più recenti dei settori sommersi circostanti le isole (putignano et al., 2009) hanno consentito di ricostruire la storia evolutiva degli ultimi 4.000 anni, a partire dalle ben documentate frequentazioni dell’età del bronzo (marazzi, 1994). le isole di vivara e procida sono caratterizzate prevalentemente da coste alte, con falesie in gran parte attive. i versanti emersi interni ed esterni del cratere di vivara mostrano pendenze anche superiori ai 40° e, in genere, coincidono con le superfici di strato per buona parte della loro estensione. le loro porzioni inferiori individuano infatti le falesie ancora attive, le cui altezze sono comprese tra una decina di metri fino a circa 40 m. il piede delle falesie sommerse a vivara è posto ad una profondità variabile: generalmente si attesta intorno a -9/-10 m nei settori meridionali e a -10/-12 m in quelli occidentali. solo nell’area di punta mezzogiorno il piede della falesia sommersa raggiunge la profondità di -21 m. nel golfo di genito e a nord di punta capitello il piede della falesia sommersa è sepolto da depositi detritici e sabbiosi, mentre la parte esposta è alla profondità variabile compresa tra -2.5 e -5 m. l’interno del cratere (golfo di genito) è caratterizzato da una morfologia subacquea con debole pendenza che degrada dolcemente fino alla profondità di -20 m al largo di punta mezzogiorno (per la toponomastica usata qui ed in seguito cfr. fig. 2). le coste alte dell’isola di procida sono spesso caratterizzate da scarpate sub-verticali osservabili lungo i tratti di costa compresi tra punta della lingua e punta dei monaci, lungo i promontori di punta pizzaco e di santa margherita, nel tratto compreso tra capo bove e punta serra e in brevi segmenti della costa settentrionale a est di punta pioppeto. tratti di costa alta con pendenze di circa 30°-40°, spesso identificabili come versanti di strato, caratterizzano invece le coste della baia di solchiaro e la porzione settentrionale di costa a ridosso di punta pioppeto. il piede delle falesie è posto a profondità variabile tra -9 e -15 m, tranne che nella porzione del promontorio di punta serra, dove raggiunge le profondità di circa -18 m. nella porzione meridionale le falesie sommerse raggiungono profondità anche superiori a -30 m, fino ai circa -90 m di punta pizzaco e punta solchiaro. all’interno della baia di solchiaro, i versanti sommersi, il cui piede raggiunge profondità variabili tra -18 e -25 m, sono piuttosto articolati e spesso coperti da depositi detritici. i rimanenti tratti della costa procidana sono occupati da strette fasce litoranee sabbiose poco estese arealmente ed in profondità, con pendenze inferiori ad 1°, alle cui spalle si ritrovano talora falesie non più attive da un punto di vista della morfoevoluzione marino-costiera e che, tuttavia, generano occasionali crolli. 232 3. caratteristiche generali dei fondali marini pericostieri le aree di fondale marino antistanti la costa possono essere considerate la naturale prosecuzione geologica e morfologica della fascia costiera emersa. con tali settori presentano, infatti, analogie morfostrutturali e affinità litologiche. la sommersione di parti significative di coste italiane ha avuto del resto corso durante il post-glaciale, peraltro a luoghi per esempio nell’area campana con ripetute fasi di esposizione subaerea legate nell’area di studio a motivi tettonici e vulcanici. la ricostruzione dell’evoluzione dei settori sommersi costituisce, dunque, sia un importante anello di congiunzione con la storia delle aree della fascia costiera attualmente emerse, che un elemento di raccordo con i settori marini più profondi. ad una lettura comparata, un simile assemblaggio tripartito evidenzia efficacemente gli stadi più recenti relativi alle fasi di innalzamento del livello del mare nonché il ruolo della tettonica quaternaria. nell’area di studio sono presenti terreni sia vulcanici che sedimentari quaternari. più precisamente, il substrato altopleistocenico-olocenico è costituito essenzialmente da vulcaniti, mentre le coperture sedimentarie che in buona parte lo ricoprono sono interamente oloceniche. queste rappresentano l’espressione delle fasi finali (highstand system tract) della sequenza deposizionale tardo-quaternaria della fascia costiera sommersa campana. tale settore è attualmente soggetto a processi marini che vengono risentiti a partire dall’interfaccia terra-mare. in aree poco profonde, peraltro, anche l’interazione con le strutture di origine antropica influenza la distribuzione dei sedimenti attuali, come del resto ha influenzato quella dei depositi di epoca storica. i fondali marini pericostieri studiati presentano pertanto una complessa evoluzione geologicogeomorfologica. 4. elementi morfologico-strutturali 4.1 generalità l’area di studio ricade in un settore di piattaforma continentale caratterizzato da una morfologia articolata (figg. 1, 2 e 3), soprattutto per la presenza di relitti di edifici vulcanici sommersi, ma anche per gli elementi legati alle principali vie di trasporto dei sedimenti verso la scarpata continentale (canyon dohrn e magnaghi), posti immediatamente a sud della fascia rilevata. non mancano, inoltre, strutture della deformazione fragile fig. 2 carta morfostrutturale dei fondali delle isole di vivara e di procida e compresi tra queste ed il promontorio di monte di procida e capo miseno. morpho-structural map of the sea floors surrounding vivara and procida islands and of the pericoastal areas around monte di procida – cape miseno promontory. m.l. putignano & m. schiattarella 233 recente, talvolta responsabili della dislocazione degli elementi morfologici sopra menzionati. la porzione continentale dei campi flegrei che orla l’area sommersa qui investigata comprende parte del promontorio del monte di procida (fig. 2) e di quello di posillipo (fig. 3). tra questi due promontori è inclusa l’insenatura del golfo di pozzuoli, che comprende le isole di procida e vivara. queste rappresentano alti morfostrutturali di origine vulcanica che si elevano dalla piattaforma continentale, a costituire unitamente all’isola di ischia la porzione insulare dei campi flegrei. le isole di ischia, procida e vivara formano un’allineamento (fig. 1) che suddivide settori di piattaforma continentale tipologicamente differenti, separando quello antistante il litorale del basso lazio campania settentrionale, caratterizzato da processi deposizionali in atto, da quello a meridione dell’area napoletana, dominato dall’interazione accumulo-erosione (de alteriis & toscano, 2003). 4.2 i fondali pericostieri del settore insulare la fascia costiera sommersa che orla le isole di vivara e procida è delimitata a sud-ovest dal canale di ischia e a nord dal canale di procida (fig. 2). questi due bracci di mare sono caratterizzati da profondità relativamente basse: l’isobata dei -30 m collega infatti le isole di vivara e procida con quella di ischia, mentre l’isobata dei -20 m le collega con la porzione continentale dei campi flegrei, rappresentata dal monte di procida (fig. 2). nel complesso, l’area che comprende le isole flegree costituisce un alto morfologico in corrispondenza della soglia tra la piattaforma continentale del golfo di gaeta a nord e quella più profonda del golfo di napoli a sud. una simile soglia morfologica sembra marcare una zona di transizione con differenti caratteri crostali rispetto ai settori contigui (de alteriis & toscano, 2003). il canale di ischia e quello di procida rappresentano le uniche vie di transito di sedimenti dai settori di piattaforma adiacenti. i canali di procida e di ischia il canale di procida costituisce un’ampia area sub-pianeggiante che collega le isole di procida e vivara alla terraferma. l’area è caratterizzata da una serie di superfici sub-orizzontali, organizzate in più ripiani compresi tra i -6 m e i -15 m. questa quota rappresenta la profondità massima del canale (fig. 2). più precisamente, le aree terrazzate sono poste a -13/-15 m, -9/-11 m e -6/-8 m. lungo la scarpata che delimita il canale a ovest, si osserva inoltre un ripiano posto a circa -20 m, che tuttavia almeno in questa zona appare un elemento ribassato del paesaggio sommerso, forse correlabile con le superfici immediatamente superiori. ripiani posti a quote simili sono comunque largamente osservabili anche lungo la costa occidentale di procida e ad ovest di vivara. nella parte centrale del canale, una scarpata ad inviluppo basale rettilineo con direzione all’incirca n120°, interpretabile come una faglia, separa i ripiani più profondi dalle superfici che li delimitano. fa eccezione un piccolo lembo corrispondente ad una secca allungata, ricoperta da sedimenti sabbiosi di piattaforma e da biocostruzioni a fanerogame marine e bordata a sud-ovest dalla faglia sopra citata. il canale è orlato su entrambi i fianchi da scarpate controllate da faglie con direzione n20-30° ed è attraversato nella sua porzione più orientale da faglie orientate all’incirca n50-60° (fig. 4 e fig. 2). morfolineamenti in direzione e-o separano, infine, il canale dalla porzione settentrionale dell’isola di procida. famiglie di strutture fragili con orientazioni n2030° e n120° circa si trovano anche nel settore settentrionale del canale di ischia e in alcuni settori antistanti la costa occidentale di procida. la prima famiglia, in particolare, costituisce il motivo tettonico principale della morfostruttura positiva dell’isola e dei due adiacenti canali, seppur rappresentato da più linee di faglia segmentate in diversi tronconi. il canale di ischia, relativamente più profondo rispetto a quello di procida, presenta una morfologia asimmetrica, con fianchi più ripidi nel settore sud-orientale ed un’area centrale sub-pianeggiante che si estende fino ai settori antistanti l’isola di vivara. nel canale si rileva la presenza di superfici piane sommerse di significativa estensione, al pari di quanto osservato a nord di procida. questi elementi sono riconducibili ad ampi terrazzi posti alle profondità di -28/-30 m, -23/-26 m, -20/-21.5 e -18/-20 m. la morfologia sommersa suggerisce la presenza di diverse faglie e fratture con gli andamenti sopra ricordati (fig. 2 e fig. 5a). nella parte settentrionale del canale di ischia, all’interno dell’ampia area sub-pianeggiante, si elevano i relitti di edifici vulcanici le cui sommità costituiscono le secche delle formiche e dei ruommoli (fig. 2). più al fig. 3 carta morfostrutturale del tratto pericostiero antistante il promontorio di capo posillipo e l’isola di nisida. morpho-structural map of the pericoastal area around cape posillipo and nisida island. geomorfologia strutturale e domini di frattura dei fondali ... 234 largo, nel settore meridionale, ad una profondità compresa tra -50 e -70 m, altri due relitti vulcanici sono responsabili della presenza delle secche della catena e di pertuso (non comprese nell’area mostrata in fig. 2). la forte asimmetria del canale di ischia determina un’area con un accentuato idrodinamismo (de alteriis & toscano, 2003) e variabilità stagionale dei flussi di entrata e uscita delle masse d’acqua (düing, 1965). l’isola di vivara promontorio santa margherita l’isola di vivara è caratterizzata da una forma semicircolare, riconducibile alla sua genesi vulcanica, che prosegue nel promontorio di santa margherita (isola di procida). nell’area emersa è infatti possibile tracciare parte dell’orlo del cratere grazie allo smantellamento erosivo delle coperture piroclastiche più recenti. l’insenatura del golfo di genito rappresenta la parte centrale del cratere attualmente sommersa. il cratere, aperto a sud, è in realtà comunicante anche verso nord con l’area della baia di ciraccio. nella parte settentrionale del golfo di genito, vivara è infatti collegata al promontorio di santa margherita tramite un ponte, adagiato su fondali che raggiungono profondità molto basse (3 m ca.). l’attuale assetto della morfostruttura vulcanica di vivara è dovuto anche alla scomposizione dell’edificio ad opera di faglie con diverse orientazioni (n-s, n70°, n110°, n135°), come peraltro suggerito dall’andamento rettilineo di tratti della linea di costa (come tra punta d’alaca e punta mezzogiorno) e dalla batimetria che evidenzia in alcune aree scarpate rettilinee, più pronunciate nei settori meridionali, con una sostanziale asimmetria dei fianchi sommersi. di girolamo & stanzione (1973) attribuiscono l’assetto descritto ad un collasso vulcano-tettonico dovuto alla formazione di un successivo cratere, tentativamente ubicato allo sbocco del golfo di genito. all’altezza di punta d’alaca, l’intenso stato di fratturazione delle vulcaniti dell’unità di vivara e i fenomeni di scalzamento al piede ad opera del moto ondoso sono responsabili dei fenomeni di instabilità attualmente osservabili. gli andamenti degli elementi morfostrutturali riconosciuti sono in accordo con i sistemi di frattura rilevati nelle vulcaniti di vivara e della solfatara di pozzuoli (fig. 6). fig. 4 profilo sismico interpretato attraverso il canale di procida in direzione no-se, acquisito durante i lavori del progetto carg (regione campania, foglio isola di procida, scala 1:50.000; per l’interpretazione cfr. anche sacchi et al., 2009). acronimi delle unità, dalla più antica: pre-tgc = successioni piroclastiche precedenti il tufo grigio campano; tgc = successioni del tufo grigio campano (39 ka, de vivo et al., 2001); post-tgc = successioni piroclastiche e marine successive al tufo grigio campano; smo = sedimenti marini olocenici ed attuali. le faglie sono tracciate in bianco, mentre i limiti stratigrafici sono riportati in nero; discontinuità di ordine minore sono rappresentate da linee nere in tratteggio; la superficie di abrasione marina alla profondità di -14 m è indicata dalla linea tratteggiata e relativa batimetria. nw-se trending interpreted seismic profile across the procida channel (data from carg project, regione campania, sheet “isola di procida”, scale 1:50.000; see also sacchi et al., 2009, for an interpreted profile). legend: pre-tgc = pyroclastic units placed before the “tufo grigio campano” formation emplacement; tgc = “tufo grigio campano” fm. (39 ka, after de vivo et al., 2001); post-tgc = pyroclastic and marine successions younger than the “tufo grigio campano” fm.; smo = holocene and present marine sediments. faults traced in white, whereas stratigraphic boundaries are reported in black; minor unconformities are represented by dotted black lines; -14 m marine abrasion surface is indicated by a dotted line. fig. 5 rose diagrams relativi alle famiglie di discontinuità tettoniche dei fondali rilevati: a) faglie e fratture alla scala cartografica; b) diaclasi misurate alla scala dell’affioramento. rose diagrams of the joint sets from the surveyed sea floors: a) map-scale faults and fractures; b) outcrop-scale tectonic joints. m.l. putignano & m. schiattarella intorno all’alto morfostrutturale di vivara prevalentemente ad ovest e a sud-ovest dell’isola, in coincidenza con i fondali del canale di ischia sono presenti ampie superfici terrazzate sommerse. la maggior parte presentano la tipica forma e continuità di terrazzi marini di origine erosionale (putignano et al., 2009). oltre a quelli più profondi del canale di ischia, si osservano comunemente terrazzi a -18/-20 m, -15/-16 m e -13/-14 m. a minore profondità (-9/-10 m), superfici piane rappresentate da piccole piattaforme di abrasione intagliate prevalentemente nelle vulcaniti di vivara si ritrovano a punta d’alaca, mentre il terrazzo costituito da lembi con la maggiore continuità di espressione morfologica si osserva alla profondità di -5.5/-6 m. in particolare, quest’ultimo ordine è ben visibile nel tratto compreso tra punta mezzogiorno e punta d’alaca. tali superfici sono spesso butterate da forme costiere quali pozze e vasche di evorsione marina, particolarmente evidenti nel caso della superficie presente lungo costa a nordovest di punta mezzogiorno, dove è presente un campo di marmitte di erosione marina, anche di grosse dimensioni. all’interno del cratere di vivara, e dunque nella baia del golfo di genito, lungo le falesie sommerse sono spesso scolpiti piccoli lembi di una piattaforma marina a quota di circa -1 m, a cui sono talvolta associati solchi di battigia. ulteriori testimonianze di antichi livelli del mare sono fornite da simili indicatori geomorfologici al le profondità di -2.7 m e -3.5 m (putignano et al., 2009). l’isola di procida le numerose insenature semicircolari che orlano l’isola di procida le conferiscono una morfologia costiera piuttosto articolata. tali baie coincidono con i relitti degli edifici vulcanici, le cui forme proseguono in alcuni casi sotto il livello del mare, parzialmente o totalmente erose dal moto ondoso. la loro assenza in ambiente sottomarino è imputabile anche a motivi strutturali, come nel caso di vivara o di terra murata, dove le faglie con diversi andamenti hanno disarticolato i crateri, o all’infill sedimentario delle morfostrutture negative, come nel caso di solchiaro. ben conservati anche sotto il livello del mare risultano i crateri di pozzo vecchio, perfettamente preservato nel settore nord-ovest a ridosso della costa, e di fiumicello, osservabile più al largo, a nord di capo bove nel settore settentrionale dell’isola. al largo del tratto costiero della spiaggia della chiaiolella, a partire dalle profondità di -40 m fino alla profondità di -20 m, si rileva la presenza di ripide scarpate ad andamento semicircolare, riconducibili alla struttura del vulcano dei ruommoli, il cui orlo, interamente sommerso, è ancora in parte ben visibile seppur tagliato da più superfici erosionali. l’assetto generale dell’isola è certamente riconducibile ai numerosi collassi vulcano-tettonici, anche coevi alla formazione di altri edifici vulcanici. le faglie che bordano l’alto strutturale di procida (fig. 2 e fig. 5a), inoltre, dislocano ed elidono parte degli apparati. i principali lineamenti morfostrutturali evidenziati dall’andamento batimetrico dei fondali che circondano l’isola sono riconducibili a famiglie di faglie e fratture orientate parallelamente a tratti rettilinei di costa. in particolare, nel settore orientale sono individuabili lineamenti prevalentemente orientati secondo gli andamenti nne-sso e ne-so (fig. 2). quest’ultima famiglia è per esempio rappresentata dalla faglia antistante l’area di punta dei monaci, ben visibile a circa 25 m di profondità, caratterizzata da una scarpata di circa 4-5 m ricoperta da depositi sabbiosi di esiguo spessore. nella porzione settentrionale predominano lineamenti orientati intorno all’andamento n100-110°, segmentati da discontinuità disposte in senso meridiano (fig. 2). nel settore occidentale, al pari di quello orientale, è riconoscibile una famiglia di faglie orientate secondo la classe azimutale n20-30°. una modesta parete corrispondente ad una scarpata di faglia con tale andamento è stata osservata a circa 15 m di profondità (fig. 7a). un simile trend si riscontra anche per la costa a ridosso della spiaggia della chiaiolella, la più ampia dell’isola, che sembrerebbe pertanto di origine tettonica. a questa famiglia si associa un set di strutture, interpretabile come di secondo ordine rispetto all’andamento predominante, in direzione all’incirca n-s (fig. 2). durante i rilievi subacquei sono state misurate le diaclasi che interessano le unità vulcaniche (fig. 5b): le fratture alla mesoscala ricalcano in generale gli andamenti descritti per le discontinuità e i morfolineamenti maggiori (fig. 2 e fig. 5a), e le famiglie di frattura rilevate nelle aree emerse (fig. 6). analogamente con quanto osservato nel canale di ischia e nei dintorni di vivara, le faglie presentano scarpate più ripide nei settori orientali, evidenziando una generale asimmetria dell’alto morfostrutturale, con fondali che verso est digradano più rapidamente verso profondità maggiori. intorno all’alto strutturale di procida sono presenti 235 fig. 6 diagramma azimutale del sistema di fratturazione rilevato nella aree emerse, e segnatamente nelle piroclastiti basali dell’isola di vivara e in quelle del vulcano della solfatara di pozzuoli nella porzione continentale dei campi flegrei. rose diagram of the joint sets from the surveyed subaerial areas (vivara island and solfatara volcano in the continental portion of the phlegraean caldera). geomorfologia strutturale e domini di frattura dei fondali ... diversi ordini di superfici piane sommerse, interpretabili nella maggior parte dei casi come superfici terrazzate di origine marina legate a paleolivelli di base dell’erosione. come per l’isola di vivara, le superfici sub-orizzontali sono infatti prevalentemente erosionali e solo in subordine possono avere un’origine strutturale (putignano et al., 2009). le superfici presentano la tipica forma e continuità di terrazzi marini, soprattutto nel settore occidentale e nord-occidentale, e sono perfettamente correlabil i con quelle che circondano l’isola di vivara. particolarmente sviluppati sono i terrazzi posti alle profondità di -29 m, -24/25 m, -20/-21.5 m, -18/-19 m e -14/-16 m, tutti visibili a largo di ciraccio. un terrazzo di abrasione marina posto a -24/25 m taglia i tufi di solchiaro ad ovest della omonima punta. terrazzi a profondità minori si ritrovano a -13/-14 m, ben espressi nel canale di procida. a quest’ultimo ordine si associano elementi erosionali a scala minore, quali solchi di battigia (fig. 7b), osservabili in località fiumicello, e piccole piattaforme di abrasione marina, poco ampie, ma che presentano continuità areale in tutta la baia di solchiaro, talora ricoperte da depositi detritici. lembi di piattaforme di abrasione marina intagliate prevalentemente nelle unità vulcaniche si ritrovano a -9/-10 m nella baia di solchiaro, caratterizzate anche dalla presenza di bitte di probabile età romana (putignano et al., 2009). le piattaforme di abrasione arealmente più rappresentative, corredate di marmitte di abrasione e testimonianze archeologiche, si ritrovano a quota -5.5/-6 m nelle zone di fiumicello (a punta faro), nella baia di solchiaro (fig. 7c) e lungo il promontorio di santa margherita. altre evidenze geomorfologiche sono inoltre riferibili a lembi di piattaforme di abrasione marina a profondità di -3.5 m, come documentabile a punta faro (putignano et al., 2009). 4.3 i fondali pericostieri del settore continentale la morfologia dei fondali che bordano il settore continentale dell’area di studio è caratterizzata da 236 fig. 7 a) scarpata di faglia in parte smantellata dall’erosione, il cui piede è posto a circa 15 m di profondità a ridosso di capo bove (isola di procida): la linea tratteggiata bianca corrisponde all’orlo superiore della scarpata, la linea tratteggiata in blu corrisponde alla superficie erosionale di origine marina posta a quota -10 m; b) solco di battente presente in località fiumicello (isola di procida) a quota di circa -14 m; c) marmitte di abrasione presenti nell’area a so del promontorio di solchiaro (isola di procida), indicanti un paleolivello di base dell’erosione posto a quota circa -5/-6 m; d) forme alveolari legate all’azione erosiva del mare presenti su un terrazzo marino posto a quota circa -6 m presente nei fondali ad ovest della gaiola (capo posillipo). a) fault scarp, partly disrupted by erosion, whose foot is located at about 15 m of depth, near cape bove (procida island): dashed white and blue lines respectively mark the upper edge of the scarp and the -10 m erosional terraced top; b) -14 m notch at fiumicello (procida island); c) marine abrasion potholes located south-west of solchiaro promontory (procida island), indicating a base-palaeolevel of the erosion at -5/-6 m of depth; d) cell-like morphology due to marine erosion at the top of the -6 m terrace located west of gaiola (cape posillipo). m.l. putignano & m. schiattarella deboli pendenze con vasti tratti sabbiosi e dalla presenza di zone sia di accumulo che di trasporto di sedimenti, che si alternano a tratti di costa alta. l’area investigata comprende il settore più meridionale del promontorio di monte di procida, la cui costa ad ovest di capo miseno fronteggia il canale di procida (fig. 2) e chiude verso ovest il golfo di pozzuoli, ed il settore di capo posillipo, che oltre ad includere nisida, la più piccola delle isole minori costituisce l’alto morfostrutturale che delimita ad est l’ampia baia puteolana. i fondali pericostieri dei due promontori che confinano il golfo sono peraltro le aree che meglio si prestano allo studio morfostrutturale, a causa del diffuso affioramento di substrato vulcanico e delle strutture che lo caratterizzano. capo miseno monte di procida immediatamente ad ovest del promontorio di capo miseno si dipana il litorale sabbioso compreso tra l’isola di san martino e miliscola, poco al largo del quale affiorano estesamente i prodotti dell’ignimbrite campana auctt., a luoghi ricoperti dai sedimenti dei fondi mobili. il promontorio di capo miseno è diffusamente orlato da falesie sommerse che si spingono alla profondità massima di -18 m, nelle quali sono talora intagliati piccoli lembi di terrazzi di abrasione marina posti alla profondità di circa -5/6 m e -3 (fig. 2), quest’ultimo evidenziato anche da solchi di battigia. dei tre crateri ubicati in terraferma, riferibili all’attività recente dei campi flegrei, solo quello centrale (baia di porto miseno) appare ben preservato, chiuso verso mare dalla struttura di punta pennata punta del terono che continua in gran parte nella settore sommerso. l’assetto morfobatimetrico suggerisce la presenza di morfolineamenti con varie orientazioni (n140°, n170°, n10° e n120°) che circondano il promontorio di capo miseno. l’esistenza di alcuni di questi elementi strutturali, interpretabili come fratture, è corroborata dall’allineamento secondo gli stessi andamenti di punti di emissioni gassose. isola di nisida capo posillipo questa porzione dei fondali pericostieri continentali è modellata nelle piroclastiti relative al ciclo del tufo giallo napoletano (ca. 15 ka b.p., in deino et al., 2004) e caratterizzata da una morfologia piuttosto articolata. la porzione emersa dell’isolotto di nisida, costituito da prodotti più recenti (ca. 3.9 ka b.p., in fedele et al., a cura di, 2010), è rappresentata quasi per intero dall’orlo del cratere del vulcano omonimo, aperto solo in corrispondenza dell’ingresso di porto paone. nell’area prospiciente l’isola si rileva la presenza di una superficie con pendenza di circa 2-3°, forse interpretabile come un terrazzo di abrasione marina in roccia, a profondità comprese tra -27 m e -21 m. più probabilmente, questo elemento morfologico corrisponde a due superfici distinte, come del resto osservabile ad est di quest’area. a largo di porto paone si eleva, a partire dalla profondità di circa -24/-25 m, un alto morfostrutturale caratterizzato da affioramenti di tufi giallastri stratificati messi in posto prima dell’attività che ha dato origine al vulcano di nisida. tali tufi sarebbero connessi agli ultimi eventi deformativi che hanno interessato il golfo di pozzuoli (milia et al., 2000) e riferibili all’attività eruttiva che ha generato il cratere di capo miseno (5.1 ka in insinga et al., 2006). la genesi della superficie dei -24/25 m precede pertanto tale attività. altri lembi di superfici terrazzate si ritrovano alle profondità di -19/-20 m e -13/-16 m. quelli riferibili a quest’ultimo ordine individuano terrazzi in roccia che rasano la sommità dei rilievi sottomarini presenti a sud di porto paone e sul prolungamento a mare del promontorio della gaiola. a profondità minori si osservano superfici di abrasione marina intagliate nelle falesie sommerse all’altezza della gaiola a profondità di -12 m, -9/-10 m, -7/-8 m e -5/-6 m. questi ordini di terrazzi sono inoltre ben visibili lungo tutto il promontorio di capo posillipo ad est della gaiola (fig. 7d). l’assetto morfobatimetrico è condizionato dalla presenza di una famiglia predominante di strutture fragili, con direzione n50-60° (fig. 3), che nel loro insieme costituiscono una gradinata di faglie. ad ovest della gaiola si osserva una faglia orientata all’incirca n-s, responsabile del ribassamento del lembo occidentale, che sembra più giovane della famiglia rappresentata dalla classe azimutale n50-60°. le fratture alla mesoscala mostrano direzioni n50°, congruenti con le strutture maggiori, ed e-o (fig. 5b). 5. conclusioni la geometria planimetrica del campo deformativo ricavato dai rilievi diretti, dall’interpretazione di profili sismici (canali di procida e di ischia) e, soprattutto, dall’analisi morfobatimetrica dell’area mostra, per la porzione insulare, una configurazione “a scaglioni”, rappresentata da tre settori di dimensioni areali simili. questi sono, da nord: i) canale di procida; ii) isola di procida p.p.; iii) promontorio di solchiaro isola di vivara canale di ischia. i tre settori così identificati (fig. 8) sono orlati a est e ad ovest da faglie con direzione nei quadranti ne e so, e risultano fisiograficamente separati – con un apparente offset destro da linee orientate da e-o a n120°. è tuttavia probabile che queste ultime rappresentino strutture di trasferimento della deformazione estensionale che ha agito lungo le faglie maestre orientate nne-sso. in tal caso, pertanto, le strutture “trasversali” rispetto all’allungamento dell’intero alto morfostrutturale assumerebbero una cinematica indotta, caratterizzata da movimento orizzontale sinistro. ad ogni modo, un simile sistema di fratture doveva caratterizzare l’area anche prima dell’attività vulcanica più antica, nel corso del pleistocene superiore, ed è verosimile che abbia condizionato gran parte degli eventi eruttivi. il campo deformativo fragile è del tutto simile a quello dedotto dall’analisi mesostrutturale delle aree emerse (fig. 6), a sua volta comparabile con quello regionale. il quadro morfostrutturale dell’area pericostiera flegrea è complicato dai diversi ordini di superfici erosionali sommerse che testimoniano le variazioni del livello del mare olocenico. le superfici terrazzate poste alle profondità maggiori nel canale di ischia “rasano” i terreni vulcanici più antichi dell’intera area (> 70-75 ka b.p.) e parte delle faglie, mentre appaiono dislocate dalle faglie con andamento nne-sso. poiché tutte le superfici erosive orizzontali sommerse poste a profondità inferiori ai 20 m sono state attribuite, su base geoarcheologica, all’olocene e segnatamente al bronzo antico bronzo medio italiano (putignano et al., 2009), si può supporre che anche quelle più profonde (intorno 237geomorfologia strutturale e domini di frattura dei fondali ... ai -25/-30 m) siano state originate durante il post-glaciale e che siano dunque successive alle eruzioni del tufo giallo napoletano (ca. 15 ka b.p., in deino et al., 2004). lo stesso quadro è del resto osservabile sia per il canale di procida, dove le superfici erosionali tagliano terreni appartenenti all’ignimbrite campana auctt. (ca. 39 ka, 40ar/39ar; ricci, 2000; de vivo et al., 2001), che per il settore centrale (isola di procida), dove vengono terrazzati i tufi di solchiaro (ca. 18 ka b.p.) ad opera delle superfici poste a -24/-25 m. si noti che una di queste superfici, a largo di nisida, appare fossilizzata dai depositi tufacei che costituiscono un alto morfologico sommerso correlato all’attività di capo miseno (5.1 ka in insinga et al., 2006). la famiglia di faglie che disloca il tufo giallo napoletano nella zona di capo posillipo, non presente nell’area procidana, è 238 fig8 schema cinematico dell’area insulare procidana (nel riquadro, ubicazione dell’area di studio nello schema morfo-batimetrico del golfo di napoli). kinematic scheme of the procida island area (in the frame: location of the study area in the morpho-bathymetric sketch map of the bay of naples). profondità età tasso di subsidenza delle superfici della superficie relativa superficie a – 24 m 6000 y b.p. (1) 4.0 mm/a superficie a – 20 m 3900 y b.p. (2) 5.1 mm/a superficie a – 18 m 3650 y b.p. (3) 4.8 mm/a superficie a – 14 m 3500 y b.p. (4) 4.0 mm/a superficie a – 9 m 2000 y b.p. (5) 4.5 mm/a superficie a – 6 m 1000 y b.p. (6) 6.0 mm/a profondità correzione età tasso di delle superfici eustatica della superficie subsidenza superficie a – 24 m -6.2 m 6000 y b.p. 2.9 mm/a superficie a – 20 m -3.2 m 3900 y b.p. 4.3 mm/a superficie a – 18 m -3.0 m 3650 y b.p. 4.1 mm/a superficie a – 14 m -2.8 m 3500 y b.p. 3.2 mm/a superficie a – 9 m -1.3 m 2000 y b.p. 3.8 mm/a superficie a – 6 m -0.5 m 1000 y b.p. 5.5 mm/a tab. 1 – tassi di subsidenza relativa dei diversi ordini di superfici di erosione; 1) inizio risalita eustatica post-optimum climatico; 2) eruzione del vulcano di nisida; 3) passaggio bronzo antico – bronzo medio italiano (insediamento miceneo di punta mezzogiorno, vivara, e superfici a -18 m in putignano et al., 2009); 4) bronzo medio italiano (insediamento miceneo di punta d’alaca, vivara, e superfici a -14 in putignano et al., 2009); 5) epoca romana ii secolo a.c. (superfici a -10 m circa, baia, campi flegrei continentali, in pappalardo & russo, 2001); 6) epoca medioevale (superfici a -6 m circa, baia, campi flegrei continentali, in pappalardo & russo 2001). relative subsidence rates for different orders of erosional submarine land surfaces. 1) starting of post-climatic optimum eustatic rising; 2) nisida volcano eruption; 3) italian old bronze age middle bronze age transition (punta mezzogiorno mycenaean settlement, vivara island, and erosional surfaces at -18 m, after putignano et al., 2009); 4) italian middle bronze age (punta d’alaca mycenaean settlement, vivara island, and erosional surfaces at -14, after putignano et al., 2009); 5) roman period ii century b.c. (erosional surfaces at about -10 m, baia, continental phegraean fields, after pappalardo & russo, 2001); 6) middle ages (erosional surfaces at about -6 m, baia, continental phegraean fields, after pappalardo & russo, 2001). tab. 2 tassi di subsidenza con correzione eustatica calcolati per i diversi ordini di superfici di erosione. eustatically corrected subsidence rates for different orders of submarine erosional land surfaces. m.l. putignano & m. schiattarella invece orientata n50-60°. a tal proposito, è da notare che un simile andamento caratterizza anche le fratture rilevate direttamente in ambiente subacqueo e associate a manifestazioni idrotermali, oltre che da allineamenti di punti di emissione gassosa. appare dunque verosimile che questo trend rappresenti le strutture attive in tempi recenti, peraltro fossil izzate solo da superfici erosionali più giovani attribuibili all’età del bronzo medio (putignano et al., 2009), poste a -14/-15 m di profondità. infine, le superfici a profondità di -9/-10 m, attribuite al periodo romano nel settore continentale flegreo (baia e capo miseno) da pappalardo & russo (2001), intagliano i versanti sommersi dell’ isola di nisida, costituiti da prodotti vulcanici di età intorno a 3.9 ka b.p.: poiché tali piroclastiti poggiano sulla superficie di abrasione dei -20 m, attribuita al bronzo antico (putignano et al., 2009), il quadro cronologico e morfoevolutivo presentato appare piuttosto consistente. la costanza del tasso di subsidenza relativa calcolato per le superfici intorno ai -24 m, -20/-21 m, 18/-19 m, -14/-16 m e -9/-10 m, che risulta attestato intorno ai 4-5 mm/a (tab. 1), suggerirebbe un’evoluzione costante nel tempo del sistema sommerso studiato, scandita dal regolare modellamento e successiva sommersione delle superfici di abrasione marina in un contesto di costante subsidenza vulcano-tettonica. tuttavia, utilizzando le curve di risalita del livello del mare postglaciale (lambeck & bard, 2000; bard et al., 2002; lambeck et al., 2004a, 2004b, 2010) ai fini della correzione eustatica nel computo dei tassi, si ottiene un quadro maggiormente articolato (tab. 2), caratterizzato dall’alternanza di periodi a diversa velocità di subsidenza (fig. 9). questo andamento appare certamente più realistico, sia in virtù dell’instabilità dell’area flegrea – con particolare riferimento alla mobilità verticale degli elementi fisiografici costieri – e della sua natura, legata all’evoluzione di un sistema vulcanico complesso, che della uniformità della curva di risalita del livello del mare nell’intervallo di tempo considerato. ringraziamenti gli autori desiderano ringraziare il prof. paolo orrù ed un anonimo referee per l’accurata revisione del manoscritto e gli utili consigli. lavoro stampato con il contributo dei fondi di ateneo 2008 (università della basilicata, resp. prof. m. schiattarella). si ringrazia inoltre la dott.ssa l. monti (regione campania, responsabile del progetto carg aree marine costiere) per aver reso possibile l’utilizzo degli elaborati batimetrici e dei profili sismici prodotti nel progetto. bibliografia acocella v. & funiciello r. (1999) the interaction between regional and local tectonics during resurgent doming: the case of the island of ischia, italy. journ. volc. geotherm. res., 88, 109-123. aiello g., budillon f., de alteriis g., ferranti l., marsella e., pappone g. & sacchi m. (1997) late neogene tectonics and basin evolution of the southern italy tyrrhenian margin . abstract international cong. “ilp task force: origin of sedimentary basins”, 6-7, torre normanna (palermo, italy). aiello g., barra d., de pippo t., donadio c. & petrosino c. (2007) geomorphological evolution of phlegrean volcanic islands near naples, southern italy. z. geomorph. n.,f. 51, 165-190. alessio m., bella f., improta s., belluomini g., calderoni g., cortesi c. & turi b. (1976) university of rome carbon-14 dates xiv. radiocarbon, 18, 321-349. 239 fig. 9 comparazione dei marker geomorfologici delle variazioni del livello del mare e la curva glacio-eustatica di lambeck et al. (2010). in grigio, l’inviluppo entro cui ricadono le curve per i siti italiani selezionati nel lavoro; all’interno di questo, la linea tratteggiata in nero corrisponde alla curva relativa alle aree a nord della piana campana (sito 7), utilizzata per la calibrazione delle quote delle variazioni relative del livello del mare dedotte dai singoli indicatori. nel riquadro in basso: tasso di subsidenza calcolato sulla base degli stessi marker. comparison between geomorphological markers related to sea-level changes and the glacioeustatic predictions (after lambeck et al., 2010). grey area include the eustatic curves of the selected italian sites; the dotted black line represents the curve from the area to the north of campania plain (site 7), used to calibrate the sea-level variations related to the single geomorphic markers. in the frame to the bottom: subsidence rate calculated by using the same markers. geomorfologia strutturale e domini di frattura dei fondali ... bard e., antonioli f. & silenzi s. (2002) sea-level during the penultimate interglacial period based on submerged stalagmite from argentarola cave (italy). earth and planetary science letters, 196, 135–146. bartole r., savelli d., tramontana m. & wezel c.f. (1984) structural and sedimentary features in the tyrrhenian margin of campania, southern italy. mar. geol., 55, 168-180. beneduce p., d’elia g. & guida m. (1988) morfodinamica dei versanti dell’area flegrea (campania): erosione in massa ed erosione lineare. mem. soc. geol. it., 41, 949-961. beneduce p. & schiattarella m. (1989-1990) studio geomorfologico-strutturale del vulcano della solfatara (campi flegrei, napoli). boll. soc. natur. in napoli, 98-99, 137-154. bruno p.p., de alteriis g. & florio g. (2002) the western undersea section of the ischia volcanic complex (italy, tyrrhenian sea) inferred from marine geophysical data. geophysical research letters, 29, 57, 1-4. channel j.e.t. & tarling d.h. (1975) paleomagnetism and the rotation of italy. earth planet. sci. lett., 25, 177-188. chiocci f.l. & de alteriis g. (2006) the ischia debris avalanche: first clear submarine evidence in the mediterranean of a volcanic island prehistorical collapse. terra nova, 18, 202-209. cinque a., aucelli p.p.c., brancaccio l., mele r., milia a., robustelli g., romano p., russo f., santangelo n. & sgambati d. (1997) volcanism, tectonics and recent geomorphological change in the bay of napoli. suppl. geogr. fis. dinam. quat., iii, 123-141. de alteriis g., tonielli r., passaro s. & de lauro m. (2006) isole flegree (ischia e procida). liguori ed., napoli. de alteriis g. & toscano f. (2003) introduzione alla geologia dei mari circostanti le isole flegree (ischia, procida e vivara). in: gambi m.c., de lauro m., jannuzzi f. (a cura di), ambiente marino costiero e territorio delle isole flegree (ischia, procida, vivara) e golfo di napoli. risultati di uno studio multidisciplinare. mem. acc. sc. mat. fis. nat., 5, 3-25, liguori editore, napoli. de astis g., pappalardo l. & piochi m. (2004) procida volcanic history: new insights into the evolution of the phlegrean volcanic district (campanian region, italy). bull. volcanol., 66, 622-641. deino a.l., orsi g., de vita s. & piochi m. (2004) the age of the neapolitan yellow tuff caldera forming eruption (campi flegrei caldera – italy) assessed by 40ar/39ar dating method. j. volcanol. geotherm. res., 133, 157-170. de vivo b., rolandi g., gans p.b., calvert a., bohrson w.a., spera f.j. & belkin h.e. (2001) new constraints on the pyroclastic eruptive history of the campanian volcanic plain (italy). mineral. petrol., 73, 47-65. di girolamo p., ghiara m.r., lirer l., munno r., rolandi g. & stanzione d. (1984) vulcanologia e petrologia dei campi flegrei. boll. soc. geol. it., 103, 349-413. di girolamo p. & stanzione d. (1973) lineamenti geologici e petrologici dell’isola di procida. rend. soc. it. mineral. petrol., 29, 81-126. doglioni c. (1991) a proposal for the kinematic modelling of w-dipping subductions possible applications to the tyrrenian-apennines system. terra nova, 3, 423-434. fabbri a., gallignani p. & zitellini n. (1981) geological evolution of the peri-tyrrenian sedimentary basins. in: wezel. f.c. (ed.), sedimentary basins of mediterranean margins. tecnoprint, bologna, italy, 101-126. fedele l., morra v., perrotta a., scarpati c., putignano m.l., orrù p. & schiattarella m. [a cura di] (2010) note illustrative della carta geologica regionale alla scala 1:10.000. isole di procida e vivara. regione campania, settore difesa suolo. napoli, in stampa. ferranti l., oldow j.s. & sacchi m. (1996) prequaternary orogen-parallel extension in the southern apennine belt, italy. tectonophysics, 260, 325-347. finetti i & morelli c. (1974) esplorazione sismica a riflessione dei golfi di napoli e pozzuoli. boll. geof. teor. appl., 16, 175-222. fusi n., mirabile l., camerlenghi a. & ranieri g. (1991) marine geophysical survey of the gulf of naples (italy): relationship between submarine volcanic activity and sedimentation. mem. soc. geol. it., 47, 95-114. ippolito f., ortolani f. & russo m. (1973) struttura marginale tirrenica dell'appennino campano: reinterpretazione dei dati di antiche ricerche di idrocarburi. mem. soc. geol. it., 12, 227-250. kastens k. & mascle j. (1988) odp leg 107 in the tyrrhenian sea: insights into passive margin and back-arc basin evolution. geol. soc. am. bull., 100, 1140-1156. insinga d., calvert a.t., lanphere m., morra v., perrotta a., sacchi m., scarpati c., saburomaru j. & fedele l. (2006) the late-holocene evolution of the south-western sector of campi flegrei as inferred by stratigraphy, petrochemistry and 40ar/39ar dating. in: de vivo b. (ed): “volcanism in the campania plain: vesuvius, campi flegrei and ignimbrites”. elsevier, amsterdam, in the series developments in volcanology, 9, 97-125. lambeck k., antonioli f., anzidei m., ferranti l., leoni g., scicchitano g. & silenzi s. (2010) sea level change along the italian coast during the holocene and projections for the future. quaternary international, in stampa. lambeck k., antonioli f., purcell a. & silenzi s. (2004a) sea-level change along the italian coast for the past 10,000 yr. quaternary science reviews, 23, 1567–1598. lambeck k., anzidei m., antonioli f., benini a. & esposito a. (2004b) sea level in roman time in the central mediterranean and implications for recent change. earth and planetary science letters, 224, 563– 575. lambeck k. & bard e. (2000) sea-level change along the french mediterranean coast for the past 30000 years. earth and planetary science letters, 175, 203-222. lirer l., rolandi g. & rubin m. (1991) 14c age of the 240 m.l. putignano & m. schiattarella “museum breccia” (campi flegrei) and its relevance for the origin of the campanian ignimbrite. journ. volcanol. geotherm. res., 48, 223-227. malinverno a. & ryan b.f. (1986) extension in the tyrrhenian sea and shortening in the apennines as result of arc migration driven by sinking of the lithosphere. tectonics, 5, 227-245. marazzi m., (1994) vivara e le prime navigazioni egeomicenee in occidente. in: vivara. centro commerciale mediterraneo dell’età del bronzo, bagatto libri, vol ii, 17-54. mariani m. & prato r. (1988) i bacini neogenici costieri del margine tirrenico: approccio sismo-stratigrafico. mem. soc. geol. ital., 41, 519-531. marsella e., budillon f., de alteriis g., de lauro m., ferraro l., molisso f., monti l., pelosi n., toccaceli r., tonielli r. & violante c. (2001) indagini geologiche, geofisiche e sedimentologiche dei fondali della baia dei maronti (isola d’ischia). salvatore pironti editore, napoli, 77 pp. milia a. (1999) aggrading and prograding infill of a peri-tyrrhenian basin (naples bay italy). geo-mar. lett., 19, 237-244. milia a. & torrente m.m. (1999) tectonics and stratigraphic architecture of a peri-tyrrhenian half graben (bay of naples, italy). tectonophysics, 315, 301-318. milia a. & torrente m.m. (2007) the influence of paleogeographic setting and crustal subsidence on the architecture of ignimbrites in the bay of naples (italy). earth and planetary science letters, 263, 192-206. milia a., torrente m.m.& giordano f. (2000) active deformation and volcanism offshore campi flegrei, italy: new data from high-resolution seismic reflection profiles. marine geology, 171, 61-73. nicolosi i., speranza f. & chiappini m. (2006) ultrafast oceanic spreading of the marsili basin, southern tyrrhenian sea: evidence from magnetic anomaly analysis. geology, 34, 717–720. ortolani f., pagliuca s., pepe e., schiattarella m., toccaceli r.m. (1992) active tectonics in the southern apennines: relationships between cover geometries and basement structure. a hypothesis for a geodynamic model. igcp nº 276, newsletter, 5, 413-419. patacca e., sartori r. & scandone p. (1990) tyrrhenian basin and apenninic arcs: kinematic relation since late tortonian times. mem. soc. geol. ital., 45, 425-451. pappalardo u, russo f. (2001) il bradisismo dei campi flegrei (campania): dati geomorfologici ed evidenze archeologiche. in: gianfrotta p.a., maniscalco f. (a cura di), forma maris. forum internazionale di archeologia subacquea, pozzuoli (napoli), 22–24 settembre 1998, 107–129. massa editore, napoli. putignano m.l., cinque a., lozej a. & mocchegiani carpano c. (2009) late holocene ground movements in the phlegrean volcanic district (southern italy): new geoarchaeological evidence from the islands of vivara and procida. méditerranée, 112, 43-50. ricci g. (2000) il distretto vulcanico dei campi flegrei: petrologia e geochimica dei depositi di breccia e dei prodotti piroclastici associati. unpublished phd thesis, università di napoli, 95 pp. sacchi m., infuso s. & marsella e. (1994) late pliocene-early pleistocene compressional tectonics in offshore campania (eastern tyrrhenian sea). boll. geof. teor. appl., 36, 141-144. sacchi m., alessio g., aquino i., esposito e., molisso f., nappi r., porfido s. & violante c. (2009) risultati preliminari della campagna oceanografica cafe_07 – leg 3 nei golfi di napoli e pozzuoli, mar tirreno orientale. quad. geof., 64, 4-26. trincardi f. & zitellini n. (1987) the rifting of the tyrrhenian basin. geo-mar. lett., 7, 1-6. 241 ms. ricevuto il 16 giugno 2010 testo definitivo ricevuto il 4 novembre 2010 ms. received: june 4, 2010 final text received: november 4, 2010 geomorfologia strutturale e domini di frattura dei fondali ... amq29(2) 6 altamura 77-90.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 29 (1), 2016, 77 89 dietary behaviour of the pleistocene cretan dwarf deer: preliminary clues from mesowear analysis of candiacervus ex gr. candiacervus ropalophorus from bate cave sara altamura dipartimento di scienze della terra, università sapienza, rome, italy corresponding author: s. altamura <sara.altamura@gmail.com> abstract: during the middle and late pleistocene crete was inhabited by endemic dwarf deer. the smallest, candiacervus ex gr. candiacervus ropalophorus (sensu palombo et al., 2008) have been believed to have inhabited rocky environments characterised by typical mediterranean vegetation. this research aims to investigate dietary behaviour in the sample of the smallest deer found in the bate cave late middle early late pleistocene deposits (152,000±20% to 105,000±20% years). the molar teeth of candiacervus ex gr. c. ropalophorus from bate cave mainly show well-defined and high cusps, sometimes also perceptible in teeth in an advanced wear stage. therefore, it seems rational to suppose that deer had an eating behaviour approaching browsers. in order to substantiate this hypothesis, it was applied the mesowear method proposed by fortelius & solounias (2000) to infer the dietary behaviour of herbivores. the method was originally based on facet development on the occlusal surface of the second upper molar tooth, then extended to other molars, although results obtained show some inconsistencies. the number of m2 specimens of candiacervus ex gr. c. ropalophorus from bate cave is too low to be statistically valid. therefore, the analysis was extended to the last two lower and upper molars, divided in group according to their wear stage, with the double aim to check the consistence of results obtained by analysing upper and lower molars and verify to which extent wear may influence the cusp shape. the results obtained by extension of the method are encouraging, in fact all the teeth reveal the same trend suggesting a prevalent mixed-feeder habit for candiacervus ex gr. c. ropalophorus from bate cave although in some individuals a more marked browsing attitude is observed. a possible diet included leaves, shrubs and other tender and nutritious vegetation. key words: candiacervus ropalophorus, crete, mesowear, dietary behaviour, pleistocene. 1. introduction the study of feeding behaviour in herbivorous mammals (ungulates) is of particular interest to infer habitat preference and behaviour of fossil herbivores and provides some clues about the environment they inhabited. the food preference, indeed, reflects the vegetation cover and availability and partition of resources. according to their feeding behaviour, herbivores are generally classified into three main ecological groups: browser, grazer and mixed feeder. cervids are a highly heterogeneous group, most of species are ecologically flexible, some inhabit different environments, and some are opportunistic / mixed feeder, changing seasonality or occasionally their diet depending on resource availability and competition with other herbivores (see inter alios geist, 1999; palombo, 2005; yamada, 2012; de marinis & toso, 2015). the varied dietary habits of herbivores may be inferred by analysing the morphology of the tooth itself. in particular, the method of mesowear analysis, as originally proposed by fortelius & solounias (2000), provides information about the prevalent feeding behaviour of a species basing on the observation of occlusal facet of the second upper molar (m2). the development of this facet is related to the relative ratio of attrition (tooth-totooth contact) and abrasion (food-to-tooth contact) that occurs during mastication activities. according to fortelius & solounias (2000) the method provides stable trophic classification when at least 20 teeth are investigated. however, in the study of fossil species, sometimes the sample is not large enough to provide firm results. afterwards, the method has been extended to other teeth including the last two upper molars (twotooth model m2-m3) (franz-odendaal & kaiser; 2003; valli & palombo, 2008), all molars (m1÷m3, kaiser & croitor, 2004; m1÷m3 and m1÷m3 louys et al., 2011) or all the chewing teeth (four-tooth model p4÷m3; p4÷m3) (kaiser & solounias, 2003; kaiser, 2003; kaiser & fortelius, 2003). the method has been applied in several studies dealing with the dietary strategy in fossil and extant herbivores, such as equidae (kaiser & solounias, 2003; kaiser, 2003; kaiser & fortelius, 2003; mihlbachler et al., 2011; loffredo & desantis, 2014), cervidae (kaiser & croitor, 2004; palombo, 2005; valli & palombo 2008; yamada, 2012) and others (franz-odendaal & kaiser, 2003; kaiser & kahlke, 2005; clauss et al., 2007; rivals et al., 2011; louys et al., 2011; solounias et al., 2014). furthermore, in order to obtain data comparable with other possible variables (e.g. hypsodonty, %grass, habitat) (rivals & semprebon, 2006; kaiser et al., 2009; valli & palombo, 2008; loffredo & desantis, 2014) the fig. 1 skulls (a: female specimen 6; b: male specimen 3), jaws (c: sn1-sx; d: 8-dx) and mounted skeletons (e) of candiacervus ex gr. candiacervus ropalophorus from bate cave (paleontological museum of sapienza university, rome). 78 altamura s. mesowear qualitative variables (or and cusps shape) were combined to convert them into mesowear score: high relief and sharp cusps = ‘‘0’’, high relief and rounded cusp = ‘‘1’’, low relief and sharp cusp = ‘‘2’’, low relief and round cusp = ‘‘3’’, low relief and blunt cusp = ‘‘4’’. indeed, a score of 0 represents the most attritiondominated mesowear signals, while a score of 4 would represent the most abrasion-dominated signals. (rivals & semprebon, 2006; kaiser et al., 2009; mihlbachler et al., 2011). the research aims to infer the dietary behaviour of the cretan endemic deer, candiacervus ex gr. candiacervus ropalophorus (sensu palombo et al., 2008) (fig. 1), found in the bate cave (rethymnon) and dated between 150,000±20% and 105,000±20% years (aar method -reese et al., 1996). during the middle and late pleistocene, the crete island was inhabited by at least five endemic deer which originated from a radiative evolutionary process that led to a niche partition among deer species differing in size, habitat and feeding behaviour (de vos, 1996, 2000). the candiacervus ropalophorus group includes the smallest among the cretan endemic deer (candiacervus ropalophorus and candiacervus sp. ii in de vos, 1979, 1984, 1996), c. ex gr c. ropalophorus is believed to have inhabited rocky environments with a mediterranean vegetation and to have had a mixed diet mainly consisting of bushes, shrubs, leaves and grass, whose availability and quality were subject to seasonal variations (caloi & palombo, 1996; van der geer et al., 2006; van der geer et al., 2010; van der geer et al., 2014; mujica, 2014; palombo & zedda, 2015). to validate such a hypothesis, i applied the mesowear method to the last two upper and lower molars also with the aim of investigating whether results obtained by analysing these chewing teeth are consistent with each other and, therefore, may provide hints to infer dietary behaviour when the m2 sample is not statistically valid, and the wear variation is particularly high. 2. materials and methods the material object of this study is kept at the paleontological museum of the la sapienza university of rome and consists of 102 molars: 25 m2, 32 m3, 24 m2 and 21 m3. i chose to analyse the upper and lower penultimate and ultimate molars because results provided by the two-tooth model (m2-m3) are similar to those obtained by analysing only m2 (franz-odendaal & kaiser, 2003), while the analysis of upper and lower m1 and p4 has been demonstrated to be less reliable (as least as ruminants is concerned, conversely to horses) (kaiser & solounias, 2003; kaiser, 2003; kaiser & fortelius, 2003) because of the extent of the wear period (see louys et al., 2011). only permanent teeth showing different wear stages have been considered. the sample does not include teeth in very advanced stage of wear. the shape of cusps of molars of deer from bate cave ranges from high and sharp in unworn teeth to low and rounded/ sharp in the most worn one. therefore, prior to performing the mesowear analysis, c. ex gr. c. ropalophorus molars were grouped according to their degree of wear. the wear classes were evaluated according the idas system (individual dental age stages) based on tooth eruption and tooth wear (anders et al., 2011) and the progressive decrease of crown height have been used as a guideline to define three wear stages: slightly worn teeth (1° wear stage, w1) (idas 2, permanent dentition is fully erupted), average worn teeth (2° wear stage, w2) (idas 3, the second molar starts to lose the inner profile), strongly worn teeth (3° wear stage, w3) (idas 4, the second molar loses the inner profile) (anders et al., 2011). it is well known that in herbivore the height of the tooth crown provides clues as regard to dietary aptitudes, because reflects the resistance of tooth to the abrasive power of food responsible for tooth wear during the masticatory process (i.e. herbivores feeding on fibrous material have a hypsodont dentition) (see inter alios fortelius, 1985; janis, 1988; janis & fortelius, 1988; damuth & janis, 2011; kaiser et al., 2013). the quantitative measure of hypsodonty, (hypsodonty index, hi) can be calculated in different ways: on m2 by dividing the height of the crown by the occlusal total length of the tooth (valli & palombo, 2008), and on m3 by dividing the height of the crown by width of the tooth (janis, 1988; fortelius & solounias, 2000; kaiser et al., 2013). appling both methods the value of the hi measured on unworn teeth is < 1.5 in brachydont, ranges from 1.5 to 3.0 in mesodont, and from 3.0 to 4.5 in hypsodont, and is > 4.5 in highly hypsodont animal. the hi of c. ex gr. c. ropalophorus has been evaluated measuring m2 and m3 at different wear stage. as regards to the parameters related to mesowear method (fortelius & solounias, 2000), the cusp height (occlusal relief-or) was defined as the difference in height between cusp tips and inter cusp valley as seen in labial projection (m2, m3) or in lingual projection (m2, m3). the or values is “high” when the result is greater than 0.1, while “low” when it is less than 0.1. the shape of the cusps was qualitatively evaluated according to three typologies: sharp, rounded, and blunt (fig. 2). all mesowear results was converted into mesowear score (kaiser et al., 2009) and plotted versus hi in order to verify whether this rating may be regarded as a valid habitat proxy (kaiser et al., 2013). data obtained for c. ex gr. c. ropalophorus have been compared with those of 63 extant species (data from fortelius & solounias, 2000; mendoza & palmqvist, 2008; kaiser et al., 2009; kaiser et al., 2013) (tab. 1). to infer the grazer versus browser ability of c. ex gr. c. ropalophorus from bate cave, a cluster analysis has been performed comparing c. ex gr. c. ropalophorus with 52 extant artiodactyl species (cervids, bovids, giraffids and camelids, data from fortelius & solounias, 2000; franz-odendaal & kaiser, 2003; louys et al., 2011) (tab. 2). the species were assigned to dietary categories on the basis of personal observation and comparing results obtained by different authors (fortelius & solounias, 2000; gagnon & chew, 2000; louys et al., 2011). four extinct species having different trophic and ecological requirement have been added to the cluster analysis (tab. 2) selected because they show a dietary behaviour of candiacervus ex gr. c. ropalophorus from bate cave (crete) 79 mesowear patter similar to that of c. ex gr. c. ropalophorus (duboisia santeng, metacervoceros rhenanus and croizetoceros ramosus) and because inhabited on a mediterranean island environments similar to those of the cretan deer (praemegaceros cazioti). two pleistocene insular species, praemegaceros cazioti from dragonara cave (sardinia) and duboisia santeng from java, and two continental villafranchian cervids metacervoceros rhenanus and croizetoceros ramosus from saint-vallier (drôme, france). the dwarf megacerine preamegaceros cazioti from dragonara cave (sardinia) was a mixed feeder inhabiting territories characterized by hard and bumpy substrate (caloi & palombo, 1991; mujica, 2014) and a vegetation cover comparable to the mediterranean scrub (palombo, 2005). the dwarf bovid duboisia santeng from java, was a forest dweller, mostly feeding on leaves and only occasionally on harder vegetation (rozzi et al., 2013). the metacervoceros rhenanus and croizetoceros ramosus villafranchian deer from sainttab. 2 the extant and fossils species were compared in this study by cluster analysis with candiacervus ex gr. c. ropalophorus from bate cave. tab. 1 date used for the construction of bivariate plot: dietary classification (dc); mesowear score (ms); hypsodonty index (hi); habitat categories (hab), 1=open, 2=intermediate, 3=closed. (data from fortelius & solounias (2000), kaiser et al., 2009, kaiser et al. (2013) and references therein). <<----------------------------------------- 80 altamura s. vallier (drôme, france) were seasonal mixed feeder with a mainly browsing feeding behaviour (valli & palombo, 2008). hierarchical cluster analysis was performed by means of past 3.13 software (hammer et al., 2001) with euclidean distances and complete linkage, using as variables the percentage of or and shape cusp resulting from mesowear analysis. three clusters analyses have been performed on three samples. in the first, cluster-a, m2 and the twotooth model approach were used irrespectively of the wear stage of c. ex gr. c. ropalophorus teeth. in the second, cluster-b, the last upper and lower molars are individually examined taking into account their wear stage. in the third, cluster-c, the two-tooth model was used, taking into account wear stage of the teeth. fig. 2 candiacervus ex gr. c. ropalophorus from bate cave (crete) (bate 6), fragment of the left maxillary with p2 m3 (on the left). the mesowear variables as in fortelius and solounias (2000) (on the right). fig. 3 upper and lower molars of candiacervus ex gr. candiacervus ropalophorus from bate cave (crete) grouped according to their wear stages: wear stage 1: a) third upper molar (labial and occlusal views); b) second lower molar (lingual and occlusal views); wear stage 2: c) third upper molar (labial and occlusal views); d) second and third lower molar (lingual and occlusal views); wear stage 3: e) second and third upper molar (labial and occlusal views); f) second and third lower molar (lingual and occlusal views). dietary behaviour of candiacervus ex gr. c. ropalophorus from bate cave (crete) 81 second lower molars (fig. 4). in teeth at first wear stage, cusps are in upper molars only sharp, while in the lower molars rounded cusps reach the 30%. as the degree of wear augments the shape of cusps changes from sharp towards lesspointed, the percentage of rounded cusps increases and some blunt cusps may be occasionally present. it is worth noting, however, that cusps are still evident even in the worn teeth. moreover, with the increasing of the wear degree, the percentage of the high cusps slightly decreases, but they are still the most abundant (fig. 5, tab. 5). the hi and ms values of the cretan small deer are very low. as regards to the clues about dietary behaviour (fig. 6) and habitat (fig. 7) obtained by plotting hi versus ms, the c. ex gr. c. ropalophorus sample fall in the ecospace of browsers and species prevalently inhabiting close environments. the cluster analysis provides a quite good resolution in splitting extant artiodactyl species according to their dietary adaptation (figg. 8a, b, c). three main groups are generally detectable, the first includes a high percentage of browsers, in the second includes mixed feeders and few browsers and grazers, in the third grazers dominate. in the cluster-a (fig. 8a), c. ex gr c. ropalophorus (crb)’s m2 falls in the mixed feeder spectrum (b.2) together with gazella granti (gg), which is a mixed feeder 3. results 3.1. wear stage in the first wear stage teeth show thin streaks of dentin. the cusps, paracone and metacone, are well defined and the median groove shows a marked "v" shape (fig. 3.a, 3.b). at the second wear stage, in the masticatory table the dentine area is wider and shows rhomboidal geometry. the infundibula are evident though reduced with respect to the previous stage, and still connected in the upper molars. the median groove is evident, but the outline is "u-shape". the cusps are still well defined (fig. 3.c, 3.d). in molars with an advanced wear degree, infundibula are greatly reduced, the dentine is exposed over the whole occlusal surface and the enamel band is thinner than that of previous wear stages. the bottom of the median groove can reach the neck, or even the roots. the cusps are still identifiable, the profile is angled or undulate, though height and shape of cusps show a quite significant variation (fig. 3.e, 3.f). 3.2. hypsodonty the average hi of c. ex gr. c. ropalophorus m2 and m3 shows values roughly consistent with each other, though hi values of m3 are generally higher than those obtained for m2. the lower third molar is, indeed, the last tooth to erupt and in extant deer the eruption is completed about 6-12 months (roe deer and red deer respectively) later than that of m2 (de marinis & toso, 2015). the average hi value in teeth at the first wear stage is < 1.5 confirming that c. ex gr. c. ropalophorus from bate cave has a brachyodont dentition (tab. 3). as expected hi decreases as the wear augments. as expected, the hi reduction is proportional to the degree of wear. furthermore, the differences in hi between teeth at the first and the second stage of wear (hi) is slightly greater in m3 than in m2, while the differences are almost the same in m3 and m2 at the second and third stages of wear. 3.3. mesowear patterns and dietary behaviour results obtained by the mesowear analysis on m2, m3, m2 and m3 of c. ex gr. c. ropalophorus from bate cave indicate that cusps have generally high (86%) and sharp/rounded (49%/48%) profiles (tab. 4). the sharp shape prevails in the second upper molar, while, rounded shapes are more frequent in the tab. 3 hypsodonty index in the last lower (m3) and second upper molars (m2) of candiacervus ex gr. c. ropalophorus from bate cave (crete), grouped according to their wear stage. tab. 4 summary of the percentage of mesowear variables in the molars of candiacervus ex gr. c. ropalophorus from bate cave (crete), overall and grouped according to their wear stage. tab. 5 percentage of mesowear variables in second and third upper and lower molars of candiacervus ex gr. c. ropalophorus from bate cave (crete), grouped according to their wear stage. 82 altamura s. but having a predominant browser behaviour (b.2.2.1.2). when the average value obtained from m2 and m3 analysis is considered (two-upper-tooth model), cretan deer still falls in mixed feeder field (b.2.2.1.2), close to m2 average value, together with ovibos moschatus (om) which is an opportunistic specie. when the average value obtained from m2 and m3 analysis is considered (two-lower-tooth model), c. ex gr c. ropalophorus falls between the mixed feeders (b.2.2.1.1) but close to antidorcas marsupialis (ma), which is an intermediate seasonal browser. in the cluster-b (fig. 8b), where the wear stages of c. ex gr. c. ropalophorus (crb) have been taken into account, two main groups are identifiable. a small group (a) including browsers, and a large one (b) gathering both mixed feeders (b.1) and grazers (b.2), which, however form two separate sister groups. the c. ex gr. c. ropalophorus m2, m3 (a.2.2) and m3 (a.1.2), at the first wear stage (w1) fall among browsers (a). in particular, m2 and m3 are linked with alces alces (aa), and m3 with odocoileus hemionus (oh), both typical browsers. conversely, m2 teeth fall among the mixed feeders (b.1.2.1.1) possibly because, although the cusps with a sharp shape predominate, the percentage of rounded cusps is not negligible (37.5%). the percentage of rounded cusps considerably increases in m2 at the third stage of wear, which fall in the grazer range (b.2.1.1.2) although the percentage of high cusps is unusually high (80%) for grazers. most of the other c. ex gr. c. ropalophorus molars, showing various degrees of wear, fall in the large group of mixed feeders together with species (e.g. gazella granti (gg), g. thomsonii (gt), g. dorcas (gd), ourebia ourebi (oo), tragelaphus strepsiceros (tt), t. imberbis (ti), but also ammodorcas clarkei (ei)) that mainly eat leaves, fruit, or fresh grass, according to the season and the availability of vegetal resources. in the cluster-c (fig. 8c), where only the two-tooth model with lower and upper molars of c. ex gr. c. ropalophorus (crb) from the first to third stage of wear have been included, the distribution of extant species belonging to the three main trophic groups is similar to that of cluster-b. as regards to cretan deer, molars at the first stage of wear fall in browser group (a), with alces alces (aa) and odocoileus hemionus (oh), while those at the second and third stage mainly fall among the mixed feeders tree. the sister group of the upper molars at the second and third wear stage and the lower molars at the third wear stage (b.1.1) includes gazella soemmerringi (gs), which feeds on bush leaves, grasses and herbs and g. dorcas (gd), which eats leaves, pods, fruits and bulbs. the lower molars at the second wear stage has as sister group (b.1.2.2.1) ovis canadensis (oc), which consumes leaves, grasses, sedges and forbs, but it usually takes some browse during winter, and gazella granti (gg), its diet consist mainly of leaves and stems. fig. 6 bivariate plot of mesowear score (ms) and hypsodonty index (hi) of extant artiodactyls and candiacervus ex gr. c. ropalophorus from bate cave (crete). data of extant species from fortelius & solounias (2000), kaiser et al. (2009) and kaiser et al. (2013) (tab.3). fig. 7 bivariate plot of mesowear score (ms) and hypsodonty index (hi) with habitat as cofactor of extant artiodactyls and candiacervus ex gr. c. ropalophorus from bate cave (crete). data of extant species from fortelius & solounias (2000), mendoza & palmqvist (2008), kaiser et al. (2009) and kaiser et al. (2013) (tab.3). dietary behaviour of candiacervus ex gr. c. ropalophorus from bate cave (crete) 83 fig. 4 comparison among the percentage of mesowear variables in second (m2u) and third (m3u) upper and lower (m2lm3l) molars of candiacervus ex gr. c. ropalophorus from bate cave (crete). fig. 5 comparison among the percentage of mesowear variables in upper and lower molars of candiacervus ex gr. c. ropalophorus from bate cave (crete) grouped according to their wear stage. f ig . 8. a c lu st er -a : h ie ra rc hi ca l c lu st er d ia gr am c om pa rin g th e on eto ot h m od el u si ng u pp er s ec on d m ol ar s on ly a nd t he u pp er a nd lo w er t w oto ot h m od el u si ng s ec on d an d th ird m ol ar s of c an di ac er vu s ex g r. c . ro pa lo ph or us f ro m b at e c av e, b as ed o n a se t ex ta nt a nd f os si l s pe ci es ( da ta f ro m f or te liu s & s ol ou ni as , 20 00 ; f ra nz -o de nd aa l & k ai se r, 2 00 3; l ou ys e t al ., 20 11 ; p al om bo , 2 00 5; v al li & p al om bo , 2 00 8; r oz zi e t a l., 2 01 3) . t he m es ow ea r va ria bl es : p er ce nt h ig h oc cl us al r el ie f, pe rc en t s ha pe c us ps ( sh ar p, r ou nd ed a nd b lu nt ). b ro w se r= u p p e r c a s e a nd g re en ; g ra ze r= lo w er c as e an d br ow n; m ix ed f ee de r= m ix ed c as e an d ye llo w ; f os si l sp ec ie s= in ve rs e m ix ed c as e an d pi nk . cr b ( bl ue )= c . ex g r c . ro pa lo ph or us f ro m b at e c av e. “ d is ta nc e” = e uc lid ea n di st an ce . 84 altamura s. f ig . 8. b c lu st er -b : h ie ra rc hi ca l c lu st er d ia gr am c om pa rin g th e on eto ot h m od el u si ng u pp er a nd lo w er s ec on d m ol ar s an d up pe r an d lo w er t hi rd m ol ar s gr ou pe d ac co rd in g to t he ir w ea r st ag e of c an di ac er vu s ex g r. c . ro pa lo ph or us fr om b at e c av e, b as ed o n a se t e xt an t a nd fo ss il sp ec ie s (d at a fr om f or te liu s & s ol ou ni as , 2 00 0; f ra nz -o de nd aa l & k ai se r, 2 00 3; l ou ys e t al ., 20 11 ; p al om bo , 20 05 ; v al li & p al om bo , 20 08 ; r oz zi e t al ., 20 13 ). t he m es ow ea r va ria bl es : pe rc en t hi gh o cc lu sa l re lie f, pe rc en t sh ap e cu sp s (s ha rp , ro un de d an d bl un t) . b ro w se r= u p p e r c a s e a nd g re en ; g ra ze r= lo w er c as e an d br ow n; m ix ed f ee de r= m ix ed c as e an d ye llo w ; f os si l s pe ci es = in ve rs e m ix ed c as e an d pi nk . cr b ( bl ue )= c . ex g r c . ro pa lo ph or us fr om b at e c av e. “ d is ta nc e” = e uc lid ea n di st an ce . dietary behaviour of candiacervus ex gr. c. ropalophorus from bate cave (crete) 85 f ig . 8. c c lu st er -c : h ie ra rc hi ca l c lu st er d ia gr am c om pa rin g th e up pe r an d lo w er t w oto ot h m od el u si ng s ec on d an d th ird m ol ar s ac co rd in g to t he ir w ea r st ag e of c an di ac er vu s ex g r. c . ro pa lo ph or us fr om b at e c av e, b as ed o n a se t e xt an t a nd fo ss il sp ec ie s (d at a fr om f or te liu s & s ol ou ni as , 2 00 0; f ra nz -o de nd aa l & k ai se r, 2 00 3; l ou ys e t a l., 2 01 1; p al om bo , 2 00 5; v al li & p al om bo , 20 08 ; r oz zi e t al ., 20 13 ). t he m es ow ea r va ria bl es : pe rc en t hi gh o cc lu sa l re lie f, pe rc en t sh ap e cu sp s (s ha rp , ro un de d an d bl un t) . b ro w se r= u p p e r c a s e a nd g re en ; g ra ze r= lo w er c as e an d br ow n; m ix ed f ee de r= m ix ed c as e an d ye llo w ; f os si l s pe ci es = in ve rs e m ix ed c as e an d pi nk . cr b ( bl ue )= c . ex g r c . ro pa lo ph or us f ro m b at e c av e. “ d is ta nc e” = e uc lid ea n di st an ce . 86 altamura s. 4. discussion and conclusion results obtained by the mesowear analysis of molars of c. ex gr. c. ropalophorus from bate cave suggest a chewing activity mainly characterised by a friction action associated with a milder abrasive component. the latter becomes more relevant as the degree of wear increases, although, in the cusps are still well delineated (fig. 3.e, 3.f). therefore, it is rational to suppose that the chewing process of c. ex gr. c. ropalophorus may have taken place in two phases. in the first phase a sharing component prevails, while in the second the sharing is progressively lost and the grinding prevails (janis, 1979; valli et al., 2012). the abrasive component equals or prevails over the frictional one if the wear is advanced. however, even at the third wear stage sharp cusps are still present (25%), suggesting that c. ex gr c. ropalophorus likely had an intermediate-browser feeding behaviour. the variation of hi at different wear stage is not particularly high being the value of hi at the last stage 58% less than at the first. it is worth noting that the typology of food may greatly affect brachyodont teeth, resulting in premature loss of its functionality (anders et al., 2011). in deer, the extent of the wear stages is not characteristic of a species, conversely intraspecific variation has been observed according to the environmental characteristic and the resources availability. accordingly, the variation in hi shown by c. ex gr. c. ropalophorus molars may be regarded as coherent with a diet consisting in no-abrasive food. this conclusion is supported by cluster analysis. the results obtained indicate that the small deer from bate cave had an intermediate-browser feeding strategy (mixed-feeder versus browser) and the diet possibly included more leaves and buds than hard grasses. the inferred feeding behaviour is supported by the cranial and mandibular features related to masticatory processes (see caloi & palombo, 1996 for a discussion). in addition, it is interesting to note how mesowear pattern slightly differs in upper and lower molars having similar wear degree (fig.8b). the cusps of second lower molar, indeed, are generally less sharp then those of last molars (tab. 5), as indicate by the position of m2 (w1-w2-w3), which mainly fall among mixed-feeder, at the first and second stage of wear, and among grazers at the third stage. this result confirms for m2 what observed by kaiser & fortelius (2003) and franzodendaal & kaiser (2003) in some herbivores. differences in the mesowear pattern shown by upper and lower cheek teeth may depend on the fact that during the masticatory process food frequently is more in contact with the lower teeth than with the upper ones. the degree of functional anisodonty and differences in mesowear pattern seem to be more pronounced in mixed feeders then in specialized feeders, though such differences are less evident when a two-tooth model is applied (fig. 8c). all in all, the obtained results indicate that c. ex gr. c. ropalophorus from bate cave had an opportunistic eating habit with a prevalent browser behaviour. these small deer on one hand possibly had a remarkable ability to select the food and change their diet according to the nature and number of competitors, the environmental characteristics and their seasonal changes, on the other they likely did not inhabited environments with a low primary productivity. acknowledgements i thank the director and staff of the paleontological museum of sapienza university of rome for giving me access to deer collections and their assistance during my research. i’m grateful to a.m.f. valli and the anonymous reviewer for their useful comments, and to m.r. palombo for suggestions and valuable discussion. this research was funded by italian murst (sapienza university of rome 2014, project c26a14bnrm led by m.r. palombo). references anders u., von koenigswald w., ruf i., smith b.h. (2011) generalized individual dental age stages for fossil and extant placental mammals. paläontologische zeitschrift, 85, 3, 321-339. caloi l., palombo m.r. (1991) morfologia e funzione della mano e del piede del megacerino del pleistocene superiore di dragonara (sardegna, italia). atti acc.peloritana dei pericolanti classe ff. mm. nn., 57 (1989), suppl. 1, 319-341. caloi l., palombo m.r. (1996) functional aspects and ecological implications in hippopotami and cervids of crete. in: reese, d.s. (ed.), pleistocene and holocene fauna of crete and its first settlers. monographs in world archaeology, prehistory press of madison, 28,125-152. clauss m., franz-odendaal t.a., brasch j., castell j. c., kaiser t. (2007) tooth wear in captive giraffes (giraffa camelopardalis): mesowear analysis classifies free-ranging specimens as browsers but captive ones as grazers. j. zoo. wild. med., 38, 433-447. damuth j., janis c.m. (2011) on the relationship between hypsodonty and feeding ecology in ungulate mammals, and its utility in palaeoecology. biological reviews, 86, 3, 733-758. de marinis a.m., toso s. (2015) valutazione dell’età nei cervidi tramite esame della dentatura. manuali e linee guida n. 90/2013, ispra. de vos j. (1979) the endemic pleistocene deer of crete. proceedings of the koninklijke nederlandse aludemie van wetenschappen, amsterdatn, seies b, 82, 1, 59-90. de vos j. (1984) the endemic pleistocene deer of crete. verhandeling der koninklijke nederlandse akadernie van wetenschappen, afdeling natuurkunde, eerste reeks, deel 31, 100. northholland publishing company, amsterdam, oxford, new york. de vos j. (1996) taxonomy, ancestry and speciation of the endemic pleistocene deer of crete compared with the taxonomy, ancestry and speciation of darwin's finches. in: reese, d.s. (ed.), pleistocene and holocene fauna of crete and its first settlers. monographs in world archaeology, prehistory press of madison, 28, 111-119. dietary behaviour of candiacervus ex gr. c. ropalophorus from bate cave (crete) 87 de vos j. (2000) pleistocene deer fauna in crete: its adaptive radiation and extinction. tropics 10, 1, 125134 [special issue]. fortelius m. (1985) ungulate check teeth: developmental, functional, and evolutionary interrelations. acta zoologica fennica, 180, 1-76. fortelius m., solounias n. (2000) functional characterization of ungulate molars using the abrasionattrition wear gradient: a new method for reconstructing paleodiets. american museum novitates, 1 -36. franz-odendaal t.a., kaiser t.m. (2003) differential mesowear in the maxillary and mandibular cheek dentition of some ruminants (artiodactyla). in annales zoologici fennici, 40, 5, 395-410. gagnon m., chew a.e. (2000) dietary preferences in extant african bovidae. j. mammal., 81, 490-511. geist v. (1999) deer of the world: their evolution, behaviour and ecology. swan hill press. shrewsbury (uk), 421. van der geer a., dermitzakis m., de vos j. (2006) relative growth of the metapodals in a juvenile island deer: candiacervus (mammalia, cervidae) from the pleistocene of crete. hellenic j geosci, 41, 119-125. van der geer a., lyras g., de vos j., dermitzakis m. (2010) evolution of island mammals. adaptation and extinction of placental mammals on islands. wiley-blackwell, london. van der geer a., lyras g., macphee r.d.e., lomolino m.v., drinia h. (2014) mortality in a predator-free insular environment: the dwarf deer of crete, 3807. american museum novitiates. hammer ø., harper d.a.t., ryan p.d. (2001) past: paleontological statistics software package for education and data analysis. palaeontologia electronica, 4(1), 9pp. http://palaeo-electronica. org/2001_1/past/issue1_01.htm janis c.m. (1979) mastication in the hyrax and its relevance to ungulate dental evolution. paleobiology, 5, 1, 50-59. janis c.m. (1988) an estimation of tooth volume and hypsodonty indices in ungulate mammals, and the correlation of these factors with dietary preference. in teeth revisited: proceedings of the viith international symposium on dental morphology (vol. 53, pp. 367-387). mémoires du muséum national d'histoire naturelle paris (serie c). janis c.m., forteliu, m. (1988) the means whereby mammals achieve increased functional durability of their dentitions, with special reference to limiting factors. biol. rev., 63, 197-230. kaiser t. m. (2003) the dietary regimes of two contemporaneous populations of hippotherium primigenium (perissodactyla, equidae) from the vallesian (upper miocene) of southern germany. palaeogeography, palaeoclimatology, palaeoecology, 198, 3, 381-402. kaiser t.m., croitor r. (2004) ecological interpretations of early pleistocene deer (mammalia, cervidae) from ceyssaguet (haute-loire, france). geodiversitas, 26, 661-674. kaiser t.m., fortelius m. (2003) differential mesowear in occluding upper and lower molars: opening mesowear analysis for lower molars and premolars in hypsodont horses. journal of morphology, 258, 1, 67-83. kaiser t.m., kahlke r.d. (2005) the highly flexible feeding strategy of stephanorinus etruscus (falconer, 1859) (rhinocerotidae, mammalia) during the early middle pleistocene in central europe. berichte der institutes für erdwissenschaften karlfranzens-universität graz, 10, 50-53. kaiser t.m., solounias n. (2003) extending the tooth mesowear method to extinct and extant equids. geodiversitas, 25, 321-345. kaiser t.m., brasch j., castell j.c., schulz e., clauss m. (2009) tooth wear in captive wild ruminant species differs from that of free-ranging conspecifics. mammalian biology, 74, 425-437. kaiser t.m., müller d.w., fortelius m., schulz e., codron d., clauss, m. (2013). hypsodonty and tooth facet development in relation to diet and habitat in herbivorous ungulates: implications for understanding tooth wear. mammal review, 43, 1,34-46. loffredo l.f., desantis l.r. (2014) cautionary lessons from assessing dental mesowear observer variability and integrating paleoecological proxies of an extreme generalist cormohipparion emsliei. palaeogeography, palaeoclimatology, palaeoecology, 395, 42-52. louys j., meloro c., elton s., ditchfield p., bishop l.c. (2011) mesowear as a means of determining diets in african antelopes. journal of archaeological science, 38, 7, 1485-1495. mendoza m., palmqvist p. (2008) hypsodonty in ungulates: an adaptation for grass consumption or for foraging in open habitat? journal of zoology, 274, 134-142. mihlbachler m.c., rivals f., solounias n., semprebon g.m. (2011) dietary change and evolution of horses in north america. science, 331, 1178-1181. mujica f. (2014) dinamiche evolutive dei cervi endemici delle isole del mediterraneo: analisi ecomorfologiche. tesi specialistica in paleontologia, univ. roma “la sapienza”. palombo m.r. (2005) food habits of “praemegaceros” cazioti (depéret, 1897) from dragonara cave (nw sardinia, italy) inferred from cranial morphology and dental wear. in proceedings of the international symposium “insular vertebrate evolution: the palaeontological approach”. monografies de la societat d’història natural de les balears, 12, 233-244. palombo m.r., kohler m., sola s.m., giovinazzo c. (2008) brain versus body mass in endemic ruminant artiodactyls: a case studied of myotragus balearicus and smallest candiacervus species from mediterranean islands. quaternary international, 182, 1, 160-183. palombo m.r., zedda m. (2015) surviving in a predator-free environment: hints from a bone remodelling process in a dwarf pleistocene deer from crete. comptes rendus palevol, http://dx.doi.org/10.1016/ j.crpv.2015.03.003 reese d.s., belluomini g., ikeya m. (1996) absolute dates for the pleistocene fauna of crete. in: reese, 88 altamura s. d.s. (ed.), pleistocene and holocene fauna of crete and its first settlers. monography in world archaeology, 28, 47–51. rivals f., semprebon g.m. (2006) a comparison of the dietary habits of a large sample of the pleistocene pronghorn (stockoceros onusrosagris) from the papago springs cave in arizona to the modern antilocapra americana. journal of vertebrate paleontology, 26, 495-500. rivals f., solounias n., schaller, g.b. (2011) diet of mongolian gazelles and tibetan antelopes from steppe habitats using premaxillary shape, tooth mesowear and microwear analyses. mammalian biology-zeitschrift für säugetierkunde, 76(3), 358364. rozzi r., winkler d.e., de vos j., schulz e., palombo m. r. (2013) the enigmatic bovid duboisia santeng (dubois, 1891) from the early-middle pleistocene of java: a multiproxy approach to its paleoecology. palaeogeography, palaeoclimatology, palaeoecology, 377, 73-85. solounias n., tariq m., hou s., danowitz m., harrison m., (2014) a new method of tooth mesowear and a test of it on domestic goats. in annales zoologici fennici, 51, 111-118 valli a.m., palombo m.r. (2008) feeding behaviour of middle-size deer from the upper pliocene site of saint-vallier (france) inferred by morphological and micro/mesowear analysis. palaeogeography, palaeoclimatology, palaeoecology, 257, 1, 106-122. valli a.m., palombo m.r., alberdi m.t. (2012) how homogeneous are microwear patterns on a fossil horse tooth? preliminary test on a premolar of equus altidens from barranco leon 5 (spain). amqalpine and mediterranean quaternary, 25, 1, 25-33. yamada e. (2012) mesowear analysis of the japanese sika deer (cervus nippon) in different food habits: its limitations and applicability. mammal study, 37, 2, 93 -103. dietary behaviour of candiacervus ex gr. c. ropalophorus from bate cave (crete) 89 ms. received: june 28, 2016 final text received: september 18, 2016 90 << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /none /binding /left /calgrayprofile (dot gain 20%) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /error /compatibilitylevel 1.4 /compressobjects /tags /compresspages true /convertimagestoindexed true /passthroughjpegimages true /createjobticket false /defaultrenderingintent /default /detectblends true /detectcurves 0.0000 /colorconversionstrategy /cmyk /dothumbnails false /embedallfonts true /embedopentype false /parseiccprofilesincomments true /embedjoboptions true /dscreportinglevel 0 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can be opened with acrobat and adobe reader 5.0 and later.) >> /namespace [ (adobe) (common) (1.0) ] /othernamespaces [ << /asreaderspreads false /cropimagestoframes true /errorcontrol /warnandcontinue /flattenerignorespreadoverrides false /includeguidesgrids false /includenonprinting false /includeslug false /namespace [ (adobe) (indesign) (4.0) ] /omitplacedbitmaps false /omitplacedeps false /omitplacedpdf false /simulateoverprint /legacy >> << /addbleedmarks false /addcolorbars false /addcropmarks false /addpageinfo false /addregmarks false /convertcolors /converttocmyk /destinationprofilename () /destinationprofileselector /documentcmyk /downsample16bitimages true /flattenerpreset << /presetselector /mediumresolution >> /formelements false /generatestructure false /includebookmarks false /includehyperlinks false /includeinteractive false /includelayers false /includeprofiles false /multimediahandling /useobjectsettings /namespace [ (adobe) (creativesuite) (2.0) ] /pdfxoutputintentprofileselector /documentcmyk /preserveediting true /untaggedcmykhandling /leaveuntagged /untaggedrgbhandling /usedocumentprofile /usedocumentbleed false >> ] >> setdistillerparams << /hwresolution [2400 2400] /pagesize [612.000 792.000] >> setpagedevice imp.marra& the albano maar (alban hills volcanic district, italy): active or dormant volcano? fabrizio marra1 & daniel b. karner2 1istituto nazionale di geofisica e vulcanologia, sezione di sismologia e tettonofisica, via di vigna murata 605, 00143 roma, italia 2department of geology, sonoma state university, 1801 east cotati avenue, rohnert park, ca 94985, u.s.a. abstract: f. marra, d. b. karner, the albano maar (alban hills volcanic district, italy): active or dormant volcano? (it issn 03943356, 2005). we discuss the geochronological interpretation of several stratigraphic sections where either primary or reworked volcanic products of the most recent eruptive activity of the albano maar are exposed. a recently performed set of 112 singleand multiple-crystal 40ar/39ar age determinations, totalling 244 dated crystals from samples of the albano products, suggests that no magmatic activity occurred after 36 ka. therefore, based on the lack of evidence for eruptive activity in historical time, albano should be defined an inactive volcano. the time elapsed since the last eruption, however, does not overrun the average recurrence time (45 kyr) for the overall volcanic activity of the alban hills volcanic district through the last 600 kyr, indicating that albano should be regarded as a dormant volcano rather than extinct. differently from direct 40ar/39ar dating of the volcanic products, recent c14 age determination on two paleosoils have suggested that eruptive activity younger than 5,000 years occurred at the albano maar. this interpretation contrasts with the absence of any volcanic deposit in the sedimentary fill of the albano crater spanning the time interval 25 ka present, therefore we believe that the possibility that the dated organic material may have been affected by problems of contamination should be carefully considered. indeed, stratigraphic, paleomorphologic and paleoclimatic data that we present in this paper are as well compatible with an early emplacement around 39-36 ka for all of these volcaniclastic products, either primary or reworked. riassunto: f. marra, d. b. karner, il maar di albano (distretto vulcanico dei colli albani, italia): vulcano attivo o quiescente? (it issn 0394-3356, 2005). in questo articolo discutiamo l'interpretazione geocronologica di alcune sezioni stratigrafiche in cui affiorano i prodotti, sia primari che rimaneggiati, della fase più recente di attività del maar di albano. una serie di 81 datazioni effettuate recentemente col metodo 40ar/39ar su singoli e multipli cristalli, per un totale di 244 cristalli datati, suggerisce l'assenza di attività magmatica posteriore a 36 ka. ne segue che, in base all'assenza di evidenza certa di attività eruttiva in tempi storici, albano dovrebbe definirsi un vulcano inattivo. d'altra parte, il tempo trascorso dall'ultima eruzione datata (36 ka) è inferiore al tempo medio di ricorrenza (45 kyr) determinato per l'intera storia eruttiva dei colli albani negli ultimi 600 kyr, indicando che albano deve considerarsi un vulcano quiescente, ma non estinto. diversamente dalle indicazioni radiometriche sui prodotti vulcanici, alcune datazioni effettuate con il metodo c14 su paleosuoli hanno fatto ipotizzare l'esistenza di attività eruttiva del maar di albano posteriore a 5000 anni fa. questa interpretazione appare in contrasto con l'assenza di prodotti vulcanici all'interno dei depositi sedimentari che colmano il fondo del lago di albano e che coprono un intervallo temporale compreso tra circa 25.000 anni fa e il presente, facendoci sospettare che l'attendibilità delle datazioni effettuate col metodo c14 debba essere più attentamente riconsiderata. effettivamente, una serie di dati stratigrafici, paleomorfologici e paleoclimatici che vengono discussi in questo articolo sembrano compatibili con una messa in posto attorno a 39-36 ka per tutti questi prodotti volcanoclastici, sia primari che rimaneggiati, affioranti nelle sezioni descritte. keywords: alban hills, albano maar, geochronology, volcanism, hydromagmatic activity, peperino. parole chiave: colli albani, maar di albano , geocronologia, vulcanismo, attività idromagmatica, peperino. il quaternario italian journal of quaternary sciences 18(2), 2005 173-185 introduction recent studies (villa et al., 1999; karner al., 2001a; funiciello al., 2002; 2003; marra al., 2003; soligo al., 2003; freda al., 2005) have focused on evaluating the stratigraphy and the geochronology of the most recent phase of activity of the alban hills volcanic district and re-evaluating its significance in terms of possible volcanic hazards for rome. however, these works sometimes proposed different stratigraphic interpretations, as well as different time intervals, for this recent volcanic activity. in particular, there is no agreement on the age of the last eruption that occurred in the albano maar, where the youngest volcanic activity occurred. this is a fundamental issue in order to establish if we have to consider the albano maar to be an active or a dormant volcano. indeed, based on the strict definit ion proposed in the smithsonian institution's catalogue of active volcanoes, only volcanoes that have erupted in the last 10,000 years should be considered active. alternatively, it is considered that a volcano is dormant when the time elapsed since its last eruption does not exceed the average recurrence period of its past activity. establishing which was the actual last eruption that occurred at the albano maar is fundamental to evaluate the recurrence times and the time elapsed since the last eruptive event, therefore it has a relevant implication on the assessment of the potential hazard for the city of rome. recent work (marra al., 2003; 174 f. marra & d.b. karner marra al., 2004) has pointed out that, based on the average recurrence time of the major volcanic cycles that occurred in the last 600 kyr, the alban hills should be considered a dormant volcano. this is based on the observation that the last eruptive cycle documented by 40ar/39ar dating in the alban hills spanned the interval 39±1 ka to 36±1 ka in the albano maar, whereas the average recurrence time through the history of this volcanic district has been estimated to being approximately 45 kyr. here we propose a re-interpretation, based on 40ar/39ar ages of volcaniclastic deposits (freda al., 2005), of the geochronology for some of the most significant sections where the youngest products of the albano activity crop out. in particular we discuss the chronostratigraphy of two sections described in previous works (gra-appia antica and lucrezia romana sections, soligo al., 2003: funiciello al., 2002; 2003), where primary volcanic deposits and post-eruptive lahars and debris-flows were interpreted to be younger than 23±6.7 ka and, in part, younger than 5±0.1 ka. we suggest that the emplacement of the most portions (if not all) of these products more likely occurred in the time span 70 36 ka. we base our interpretation on the 40ar/39ar ages achieved for the primary products cropping out at these sections, while we rely on stratigraphic correlations and paleoclimatic inferences to estimate the ages of the reworked layers. the albano maar the albano multiple-maar center (fig. 1) hosted the most recent activity of the alban hills volcanic district (villa al., 1999; karner al., 2001a; marra al., 2003; soligo al., 2003; funiciello al., 2002; 2003, freda al., 2005). it was described (de rita al., 1995a; 1995b) as a multiple tuff ring, the activity of which consisted of five main explosive cycles. the fifth eruption cycle of albano maar was driven by phreatomagmatic fragmentation and emplaced a phreatomagmatic basic ignimbrite (giordano al., 2002a). this ignimbrite is the most famous deposit of albano, as it was quarried since the iv century b.c. by the ancient roman builders and extensively used under the name of lapis albanus. the dark-grey colour and the granular texture of this rock led to the local name of “peperino” (black pepper-like), and so this unit is known in the literature also as “peperino di marino” or “peperino albano”. the eruptive activity of albano maar was dominated by surge flows which deposits typically show sharp lateral facies variations over relatively short distances. subordinate fall beds are present throughout the succession. the surge deposits commonly show planarto crosslaminations in the proximal area, whereby they have massive, lithified facies in the distal sections, where they fill paleovalleys. the scarcity of outcrops due to the vegetation cover and the large development of agricultural soils prevent the straightforward correlation through different localities, therefore making difficult the stratigraphic correlation among the different units. the petrography and chemistry of the albano products is very homogeneous (trigila al., 1995; marra al., 2003; freda al., 2005), preventing the identification of any characteristic feature that may be distinctive of the different volcanic units. these facts limit the possibility to establish stratigraphic relationships for the different volcanic units, when they do not occur in the same outcrop. a powerful tool to overcome these difficulties is the 40ar/39ar dating of the volcanic products that, based on the high precision and reliability of the method, allows for a certain correlation of primary volcanic products containing juvenile phenocrysts (karner and renne, 1998; karner al., 2001a; marra al., 2003, freda al., 2005). here we discuss the implications on the geochronology of the most recent phase of activity of recently obtained 40ar/39ar data on 12 volcanic deposits of the albano maar (freda al., 2005). these data allow us to correlate two distal sections (gra-appia antica and casale ferranti), where the supposedly youngest products are found, to the best exposed and most complete (found so far) proximal stratigraphic section, located within the crater rim of the albano maar. the correlation of these outcrops is shown in fig. 2. albano lake proximal sections the best exposed section crops out within the northern crater rim (site 1 of fig. 1, reference section of fig. 2) and shows a succession of pyroclastic deposits about 80 m thick. this succession overlies a ~1.5 m-thick mature paleosol, developed on pre-albano hydromagmatic products dated 203±1 ka and attributed to the activity of the nearby ariccia maar (marra et al., 2003). four incipiently pedogenized ash levels indicate the occurrence of four main hiatuses in the albano maar activity, while small-scale unconformities (either erosional surfaces and thin pedogenized ash layers) record less significant hiatuses. the uppermost part of the albano succession does not crop out at the reference section, whereas it is exposed in several outcrops on the eastern and southern outer rims of the albano maar. the most complete of these outcrops is shown in fig. 2 (site 1' in fig. 1). a detailed description of the stratigraphy and of the petrologic features of the products that crop out at these sections is provided in freda et al. (2005). based on 40ar/39ar ages, two major eruptive cycles, separated by approximately 30 kyr of dormancy, are recognized at the albano lake sections (fig. 2). the first cycle occurred at 69±1 ka, while the second one was characterized by two distinct eruptive sub-cycles at 39±1 and 36±1 ka (see fig. 2 and fig. 3). the first cycle produced the lower, more than 60 m thick, suite of deposits at the reference section. one faintly pedogenized ash layer occurs in the middle of the lower portion of the succession, suggesting the presence of two separate eruptions with statistically indistinguishable ages of 69.4±0.6 ka and 68.6±1.1 ka, respectively. a thick deposit of ash partially altered into clay and capped by a pedogenized layer closes the stratigraphic succession of the first eruptive cycle. two other incipiently pedogenized ash layers divide the products of the second cycle of activity into at least three different eruptions. these three eruptions occurred at radioisotopically indistinguishable times: the products at the base of the second cycle yielded an age of 41.2±1.1 ka, whereas those at the top yielded an age of 175the albano maar ... fig. 1 geologic map of the alban hills, redrawn from freda et al., 2005. schema geologico dell'artea dei colli albani, ridisegnato da freda et al., 2005. 40.9±0.8 ka. the uppermost deposit that crops out along the eastern and southern crater rim (site 1'), and that is missing on top of the reference section, yielded an age of 35.9±0.6 ka. this is a radiometrically distinct age with respect to the previous ones, and enables us to consider it to be the youngest (dated so far) product of the albano activity and to correlate it to the peperino albano that crops out in valle delle petrare. 176 valle delle petrare sections the peperino albano deposit is more commonly known by its historical name, lapis albanus. one sample of this stone, collected from the walls of an ancient roman monument (the tullianum in the carcere mamertino) was dated by 40ar/39ar methods at 35.7±1.1 ka (karner et al., 2001b). freda et al. (2005) carried out a new dating on a sample of peperino albano deposit collected in the ancient roman quarries located in valle delle petrare. this sample yielded the age 36.1±0.3 ka, in perfect agreement with that previously determined. gra-appia antica distal section 40ar/39ar datings were carried out on three samples (ah18-c1, ah18-c3, ah18-c2, see fig. 2) collected in three different volcaniclastic deposits cropping out at the gra/appia antica section (freda et al., 2005). from the bottom to the top they yielded ages of: 1) sample ah18-c1, 68.9±0.2 ka. this is the age of the first (oldest) eruptive cycle of the albano maar, as previously determined (marra et al., 2003) on the equivalent unit cropping out within the albano fig. 2 stratigraphic scheme showing the relationship among the investigated sections, as inferred from petrographic correlation and 40ar/39ar ages of the collected samples (modified from freda et al., 2005).two major eruptive cycles occurred at albano maar: the first one at 69±1 ka, and the youngest one including two statistically distinct, sub-cycles at 39±1 ka and 36±1 ka. during the youngest eruptive cycle the peperino albano pyroclastic flow was emplaced. schema stratigrafico mostrante le relazioni stratigrafiche esistenti tra le diverse sezioni studiate, basato su correlazioni pertrografiche e sulle età 40ar/39ar dei campioni analizzati (modificato da freda et al., 2005). due principali cicli eruttivi sono riconosciuti per il maar di albano: uno più antico a 69±1 ka, ed uno più giovane, che comprende due sub-cicli con età statisticamente distinte di 39±1 ka e 36±1 ka. durante l'ultimo di questi sub-cicli avviene l'eruzione del peperino albano. crater, and confirmed by the age of another sample (ah3-c9) from the upper portion of the lower succession at the albano lake reference section (see fig. 2). according to funiciello et al. (2003) the product we dated shows the feature of a primary phreatomagmatic pyroclastic-flow deposit, therefore the age of the crystals that we separated from the juvenile portion of the deposit should be considered indicative of the emplacement time. 2) sample ah18-c3, 39.0±0.2 ka. this age falls into the time span encompassed by the second eruptive cycle of the albano maar (freda et al., 2005). according to funiciello et al. (2003) we also interpret this unit to be a primary phreatomagmatic deposit, therefore also in this case the age of the dated crystals is indicative of the emplacement time. 3) age of sample ah18-c2 was obtained by combining 8 age determinations from two samples (ah18-c2 and gra-c2bis, see fig. 3) collected in the same, uppermost volcaniclastic deposit that crops out at the gra/appia antica site. these crystals yielded a combined age of 36.0±0.1 ka. this age is indistinguishable from those obtained on several samples of f. marra & d.b. karner 177 peperino albano dated so far. this uppermost volcaniclastic horizon appears to be reworked, with sorting, massive facies, stratified base and subrounding of the components, indicating a mechanism of emplacement from a hyperconcentrated flood flow (funiciello et al., 2003). the three deposits described above correspond, from lowest to highest, to the volcanic layers to which funiciello et al. (2003) have attributed the following stratigraphic and geochronologic interprertations: 1) peperino albano phreatomagmatic ignimbrite (d layer in their figure 3); 2) phreatomagmatic surge deposit (f layer in their figure 3), “...to be considered the youngest and previously never described phreatomagmatic eruption from the albano maar...”; 3) hyperconcentrated flow sandy deposit (h layer in their figure 3). based on an u/th series age (soligo et al., 2003) on a carbonate layer underlying the volcaniclastic succession at the gra/appia antica site, funiciello et al. (2003) interpreted the entire section to be younger than 23±6.7 ka. moreover, based on a 14c age of 5100±100 years b.p. on an incipiently pedogenized ash layer underlying the youngest volcaniclastic deposit (layer h in their figure 3), they interpreted the uppermost deposit as a lahar deposit originated by the overspill of the albano maar lake in historical time. the geochronologic data and the stratigraphic interpretation by funiciello et al. (2002) and soligo et al. (2003) are in strong conflict with the direct 40ar/39ar datings of these deposits, as we discuss below. casale ferranti distal section this is another location where distal products of the albano maar activity crop out. the deposits fill an ancient paleovalley and they were previously recognized and investigated through a trench excavation (lucrezia romana site, funiciello et al., 2002). we have studied this paleovalley and its volcaniclastic filling in the casale ferranti site, by means of four borecores located in a construction yard adjacent to the lucrezia romana site. we dated and analyzed two samples from these borecores, corresponding to the uppermost and to the lowermost volcanic deposits that fill the paleovalley (fig. 2). the lowest sample (ah19c2) is a well-indurated, massive deposit that yielded a 40ar/39ar age of 38.8±0.2 ka. the age and petrographic features (freda et al., 2005) of this sample match well those of sample ah18-c3 in the gra/appia antica section, and sample ah3-c14 at the albano lake section (site 1 in fig. 1). thus, this is very likely a primary product erupted during the early phase of the second eruptive cycle. the uppermost sample (ah19-c1bis) is an aggregate of rounded scoria, leucite and femic crystals, and heterogeneous l ithic fragments. two younger crystals from this sample yielded a combined age of 38.2±0.3 ka. however, the abundance of contaminant crystals (four crystals out of six, see appendix) from the scoria cones activity that ended the vil la senni eruptive sequence (351±3 – 356±4 ka, karner et al ., 2001a), and from the monte delle faete phase of activity (308±4 – 250±1 ka, marra et al., 2003), suggest that this may be a thoroughly reworked product. funiciello et al. (2002) have correlated the stratigraphic section at lucrezia romana to the similar volcaniclastic succession that fills the paleovalley in the gra/appia antica location. the correlation of the two sections is based on a 14cage of 5150±70 yrs bp obtained on a soil underlying a 20 to 50 cm thick “hyperconcentrated flow deposit” that is at the top of a volcaniclastic succession that fills the paleovalley at lucrezia romana (see fig. 5 in funiciello et al., 2002). fig. 3 ideogram (age probability diagram) of the crystal ages from all the dated samples from the albano center, using 2σ analytical error distributions. three prominent peaks are noted: ages from each sample tend to concentrate into one peak of the ideogram, supporting the interpretation of three geochronologically distinct eruptive events. single crystal ages for the samples of the youngest two eruptive events are reported, showing that the crystals which group into the two modes at 36 ka and 39 ka belong to two distinct groups of samples that have always stratigraphic position that is consistent with their radiometric age. ideogramma (diagramma probabilistico delle età) relativo alle età dei cristalli di tutti i campioni di prodotti dell'attività di albano datati, con distribuzione analitica dell'errore a 2σ. si notano tre picchi principali: l'età di ognuno dei campioni si concentra all'interno di un singolo picco dell'ideogramma, indicando l'esistenza di tre eventi geocronologicamente distinti. sono inoltre riportate le età dei singoli cristalli dei campioni che originano i due picchi più recenti, evidenziando che i cristalli che originano le due mode che definiscono due eventi eruttivi a 36 e 39 ka appartengono a due gruppi di campioni che hanno sempre una posizione stratigrafica consistente con l'età radiometrica. the albano maar ... 178 discussion 1. geochronologic and stratigraphic remarks the correlation of the primary deposits units cropping out at the gra/appia antica section with those previously studied at the albano crater by de rita et al. (1988; 1995a; 1995b) and dated by marra et al. (2003) and freda et al. (2005) is straightforward. this correlation is based on the principle of stratigraphic succession (fig. 2), and based on the high quality of the dates performed (see fig. 3 and appendix). from this large set of dated volcanic deposits we obtained ages that have always been stratigraphically consistent and that define statistically distinct eruption ages at 69±1, 39±1, and 36±1 ka. figure 3 shows an ideogram of all the crystals (112 singleand multiple-crystal age determinations involving a total of 244 crystals, see appendix) that we have dated out of 12 different samples of products of the albano activity. the inset in figure 3 shows that the crystals that group into the two modes at 36 and 39 ka belong to two distinct groups of samples that have stratigraphic positions that are consistent with their radiometric ages. therefore, the interpretation of the basal horizon of the gra/appia antica section that led funiciello et al. (2003) to identify it as a deposit of the peperino albano is not supported. indeed, except for radiometric ages of the crystals of the juvenile fraction of the deposit, there is no other macroscopic feature (either in mineralogic composition or in the sedimentologic characteristics) that can distinguish it from other distal products of the several pyroclastic-flow deposits erupted by the albano maar. moreover, the interpretation by funiciello et al. (2003), that the entire succession cropping out at the gra/appia antica section is younger than 23±6.7 ka, is in conflict with the ages obtained on crystals from the juvenile fraction of the exposed deposits. therefore, excluding that the whole volcaniclastic succession is completely reworked, the u/th series age on the carbonate layer at the base of the gra/appia antica volcaniclastic succession (soligo et al., 2003; c layer in their figure 3) should be considered the result of post-depositional process (e.g., recrystallization, significantly later precipitation of carbonate). however, there are no evidences that the succession is entirely reworked. we conclude that the two primary pyroclastic deposits, that with their supply of synand post-eruptive debris-flow deposits represent more than 90% of the entire volcaniclastic succession cropping out at the gra/appia antica site, are distal products of the two main eruptive cycles that occurred at the albano maar 69±1 ka and 39±1 ka. regarding the uppermost deposit above the soil dated 5 ka, we believe that a more thorough geochronologic investigation should be conducted in order to evidence the reliability of this young age. the 14c age of 5100 years was performed on an immature soil that occurs at less than 1 meter below the ground surface (see figure 5 in funiciello et al., 2002): in these conditions the possibility of contamination of the dated material is always possible since the shallow burial does not guarantee sealing and preservation from younger contaminant material. unfortunately, no description of the sampling and dating procedure of the paleosoil is given in funiciello et al. (2003) and in funiciello et al. (2002). funiciello et al. (2002; 2003) have not clarified if they interpret the deposit above this paleosoil to be a primary volcanic layer or a reworked product. based on the homogeneous population of crystals yielding age of 36±1 ka (evidencing lack of xenocrystic contamination) and based on the chronostratigraphic consistent position and on the petrographic characteristics of this deposit, we believe that also the third, uppermost horizon may be regarded as a syn-eruptive deposit (i.e.a syn-eruptive lahar of the peperino albano ignimbrite). therefore, we believe that the possibility that the entire volcaniclastic succession at the gra-appia antica section was deposited in the time span 70-36 ka cannot be excluded. indeed, a later deposition for the uppermost horizon that we dated to 36.0±0.1 ka is questionable based on several lines of evidence. first, the strictly homogeneous population of crystals (see appendix) indicates reworking from a single deposit (i.e. the peperino albano); this may be suitable for pyroclastic flows as well as syn-eruptive lahars, which originate at the expense of a homogeneous source material (i.e. the material from a single eruption), whereby post-eruptive lahars should more commonly embed a large amount of xenocrysts, since they usually originate from slope failures or flood events that involve deposits from different eruptions. moreover, it seems unlikely that the thin (~10 cm) incipiently pedogenized ash layer that separates this upper volcaniclastic horizon from the underlying phreatomagmatic products that yielded the age of 39.0±0.3 ka may be representative of a ~34 kyr-long hiatus in the deposition of the sequence, as it would be if the former is younger than 5 ka. this is more unlikely when one realizes that interpretations by funiciello et al. (2003) require transportation and redeposition of this material without the incorporation of xenocrysts. based on the above mentioned possible unreliability of the 14c age determination and on the absence of crystals of the youngest albano eruptive event in the uppermost unit, we suggest that further geochronological constraints should be provided in order to prove also that any portion of the volcaniclastic succession that fills the paleovalley at lucrezia romana site may be of holocene age. standing on present data, we cannot exclude that the volcaniclastic succession of the lucrezia romana site correlates to the middle stratigraphic unit at the gra/appia antica section, where a primary unit of the ~39 ka eruptive cycle is followed by debris-flow and fluvial deposit that reworked this same unit along with older volcanic units (fig. 2). 2. paleomorphological and paleoclimatic implications we point out here that the assumption of the ciampino plain being the site of catastrophic inundations in recent times due to the repeated overspill of the albano maar lake, as suggested by funiciello et al. (2002; 2003), is not the only possible interpretation of the geomorphologic feature of this area. based on 40ar/39ar data, another explanation could be that he paleo-valleys of the ciampino area were the location of the emplacement of pyroclastic flows since 70 ka, and it is not possible to exclude that they were already completely filled by 36 ka. the less pronounced erosion that occurs throughout the ciampino plain, that f. marra & d.b. karner funiciello et al. (2002: 2003) have cited as the evidence of very recent overfilling of the hydrographic network, can be explained as well as the result of the earlier emplacement of the synand post-eruptive products of albano in the time span 39-36 ka. the eruption of the peperino albano occurred at a time (36 ka) when about 80% of the erosive phase that began since ~120 ka and culminated into the würmian low-stand (~18 ka) had already occurred (bard et al., 1990; bassinot et al., 1994). the ciampino plain is located on the pyroclastic plateau at the foot of the relief of the alban hills, in a position that is significantly influenced by the processes of erosion and aggradation that occur within the main tributary valleys of the tiber river. these tributary valleys synchronously responded to the erosional-depositional processes that occurred in the tiber river valley (ammerman, 2000; karner & marra, 1998). it is clear that the emplacement of a large amount of volcaniclastic material close to the time of maximum lowering of the sea level may interfere with regular sedimentary and erosive processes and, ultimately, this may be the cause of the ciampino plain being unaffected by erosion successively to the emplacement of the peperino albano phreatomagmatic deposits. a reconstruction of the evolution of the paleovalleys in the greater area of rome is shown in figure 4. a regional uplift of ~40 m that occurred in the last 200 ka (karner et al., 2001 c) was the concomitant cause of rejuvenation of the morphological features of the hydrographic network which, at each glacial maximum in the last two marine isotopic stages 7 and 5, was excavated deeper than during the previous ones. in particular, the river incisions were substantially filled as a consequence of the sea-level rise at the peak of stage 7 (a); then, during the regressive phase culminating in the glacial maximum of stage 6, the paleovalleys were re-incised as a consequence of sea-level fall (b); however, the concomitant regional uplift of approximately 20 m in this time span caused the new excavated valleys to be deeper than those originated during previous lowstand. the subsequent sea-level rise associated to high-stand of stage 5 accounted only for partial filling of these sharp paleomorphologies (c). this phenomenon occurred also during the following, last glacial cycle (d'-e'), when other ~20 m of uplift occurred in this area, resulting in the particular feature of the hydrographic network that is characterized by "canyoning" of the holocene alluvial valley, with prominent, steep banks that border the floodplain, as it is visible in the dem image of figure 5. this feature is absent in the ciampino plain, as observed by funiciello et al (2002), as well as in other, limited sectors of the rome area. figure 4 d" shows the situation of the paleovalleys in area of rome 40 kyr ago, just before the second cycle of activity of albano started. differently than in all the other valleys in the area of rome, the incisions in the ciampino area have been filled by the deposits of the albano activity in the time span 39-36 ka (fig. 4 c'''), thus after 80% of the regression associated to the last glacial maximum had occurred (fig. 4 d"). actually, regression started after 125 ka and culminated 19 ka, whereby the peperino albano was erupted 36 ka: thus only (36-19) 17 kyr of new erosion occurred, after that the marked erosive pattern excavated in (125-36) 89 ka was obliterated by emplacement of the pyroclastic flows. retrograde erosion during the remaining 20% of the last glacial maximum was probably not enough to re-establish the morphologic features of the hydrographic network, that were excavated during the previous several erosive phases (fig. 4 c''''). the holocene sea-level rise then caused this faint morphology to be almost completely obliterated, conferring to the ciampino plain its present character (fig. 4 e'). this becomes more apparent when one realizes that a very similar phenomenon occurred toward the southeast of the albano lake, where another flat sector, similar to that near ciampino is present (figure 5). here, the holocene hydrographic network of the rio torto stream near the locality of santa procula is partially filled and obliterated by the pyroclastic flows and lahars of the 39-36 ka activity (giordano et al., 2002b; marra et al., 2003; fig. 2). this similar feature near santa procula calls for a nearly syn-eruptive infilling of the hydrographic network due to directional emission of pyroclastic flows and the related emplacement of lahars, as illustrated in figure 6, rather than being interpreted as due to the overspill of the albano lake, suggesting that the very same thing may have occurred also in the ciampino plain. 3. evidence from the sediments of the albano lake the absence of any holocene eruptive activity at the albano crater can also be inferred after a careful analyses and discussion of the borecore data of the sediments filling albano lake and the nearby nemi lake, provided by the paliclas scientific project (guilizoni and oldfield eds. 1996). the analyses of these four borecores indicate the lack of any volcanic deposit of the albano maar in the time interval 25 ka present day. the albano lake has a maximum depth of 175 m and the morphology of its bottom suggests the existence of three main craters (see fig. 7b): two craters approximately 2 km in diameter which overlap each other along a nw-se direction, and a third crater with a diameter of 0.5 km at the center of the southeastern one. the smallest crater is evidently also the youngest crater, while the northwestern crater is the oldest. we suggest that these three craters correlate to the three main eruptive cycles at 36 ka, 39 ka and 69 ka, respectively. three borecores (re-labeled here 1, 2 and 3, fig. 7) drilled at different water depths on the bottom of the albano lake were analyzed in chondrogianni et al. (1996). in borecore 1, located at higher elevation (30 m water depth), continuous sedimentary deposits of age between 25.11 and 15.78 ka (age calculated based on two calibrated ages of 21.26 ka and 18.39 ka obtained on pollen grains (errors associated with this ages are not reported), chondrogianni et al., 1996) are present above a volcaniclastic substrate, a sample of which was dated by 40ar/39ar methods at 45±3 ka (villa et al., 1999). age of this sample is consistent with that of the products cropping out at the top of the albano reference section (fig. 2) and, more in general, it is consistent at two sigma with the group of ages that constitutes the youngest sub-cycle (39±1 ka) of the second eruptive cycle of the albano maar (freda et al., 2005). in borecore 2, a longer sedimentary record, spanning the interval ~30 ka present was found above the volcaniclastic substrate dated at 26±1 ka (villa et al., 1999). 179the albano maar ... 180 fig. 4 reconstruction of the alternate phases of erosion and deposition, and the effect of regional uplift that influenced the evolution of the hydrographic network in the area of rome in the last 200 kyr. inset on the right upper corner shows the isotopic curve (redrawn from bassinot et al., 1994) for the last three glacial cycles, and the position of the ages of the eruptive cycles of the albano maar with respect the timing of the glacio-eustatic oscillations. ricostruzione degli effetti combinati dell'alterenarsi delle fasi erosive e deposizionali e del sollevamento regionale che hanno influenzato l'evoluzione del retricolo idrografico nell'area romana negli ultimi 200.000 anni. nell'angolo in alto a destra è mostrata la posizione delle età dei cicli eruttivi del maar di albano sulla porzione della curva degli isotopi dell'ossigeno relativa agli ultimi tre cicli glaciali. f. marra & d.b. karner this latter age would be the youngest eruptive product ever dated by 40ar/39ar methods at the alban hills. however, the step-heating experiments as shown in villa et al. (1999) yielded release patterns that are unusual for alban hills leucites, as stated by the same authors, and ultimately did not produce plateaus that meet standard criteria of 50% concordant 39ar release in three contiguous steps (mcdougall and harrison, 1999). additionally, those experiments used small sampling of these pyroclastic layers (1-3 crystals). given the differences in experimental techniques and methodolo181 fig. 5 dem (digital elevation map) of the alban hills and eastern rome. a prominent hydrographic network in this region is the result of approximately 40 m of uplift during the last 250 kyr (karner et al., 2001c), which produced canyon-like valleys with prominent banks over the floodplains. in this framework, several small sectors appear as isolated plateaus: the most prominent of them is the ciampino plain that funiciello et al. (2003) suggested to be the result of catastrophic inundation in historical times, due to the repeated overspill of the albano lake. however, other similar sectors, like that near the santa procula locality, are probably the result of obliteration of the paleovalleys due to emplacement of pyroclastic flows from the albano maar around 39 ka and 36 ka, after most of the erosion linked with the last glacial maximum had already occurred. immagine dem (digital elevation map) dell'area albana e dell'area orientale di roma. i caratteri molto marcati del reticolo idrografico in questa regione sono il risultato del sollevamento di circa 40 metri avvenuto negli ultimi 250,000 anni (karner et al., 2001c), che ha originato delle valli molto incise, con sponde acclivi che bordano le attuali piane fluviali, in un panorama dal rilievo molto poco marcato. in questo contesto, vi sono alcuni piccoli settori che appaiono come dei plateau isolati: il più evidente di questi è la cosiddetta piana di ciampino che funiciello et al. (2003) hanno suggerito essere il risultato di un colmamento dovuto a catastrofiche inondazioni in tempi storici, originate dalla tracimazione del lago di albano. si nota tuttavia che altri settori del tutto simili, come quello qui evidenziato in prossimità della località di santa procula, sono più verosimilmente il risultato dell'obliterazione delle paleovalli ad opera della messa in posto dei flussi piroclastici originati dall'attività del maar di albano intorno a 39 ka e 36 ka, quando gran parte dell'attività erosiva legata all'incipiente massimo glaciale würmiano era già avvenuta. fig. 6 tentative reconstruction of the spatial distribution of the products of the three geochronologically distinct eruptive cycles of albano, based on field survey data and chronostratigraphic investigation. all the eruptions seem to show nw directionality, with the exception of the first subcycle at 39 ka, which according to freda et al. (2005) is the most energetic and emplaced the largest volume of products to the nw as well as to the sw of the albano center. ricostruzione ipotetica della distribuzione spaziale dei prodotti dei tre cicli eruttivi principali del maar di albano, basata su dati di terreno e indagini cronostratigrafiche. tutte le eruzioni sembrano avere direzionalità verso nw, ad eccezione del primo sub-ciclo eruttivo di 39 ka, il quale, in accordo con freda et al. (2005), appare essere il più energetico e ha determinato la messa in posto del maggiore volume di prodotti sia verso nw che in direzione sw rispetto al centro eruttivo di albano. the albano maar ... gies, the error associated to the age of 26 ka obtained by villa et al. (1999) should be considerably expanded when this age is compared to those obtained by freda et al. (2005). therefore, we consider the age of 26±1 ka on the pyroclastic material dated by villa et al. (1999) to be undistinguishable either from the 39±1 ka or 36±1 ka groups of ages obtained for the most recent activity of the albano maar by freda et al. (2005). an age of about 25.44 ka was tentatively calculated (chondrogianni et al., 1996) for the base of the sedimentary deposit recovered in borecore 2, based on the age of 17 ka for one tephra layer recovered in this borecore and correlated to the biancavilla eruption, and assuming a constant sedimentation rate. however, sedimentation rates within a lake can be variable; chondrogianni et al. (1996) estimate the start of the sedimentation of the albano sequences recovered in the analysed borecores to be ~30 ka. if we consider that the deeper portion of the sedimentary fill of the albano lake (at least 50 m, as evidenced by the inferred depth of the lake substrate from seismic reflection data in chondrogianni et al., 1996) was not recovered in the analysed borecores (see fig. 7), it is reasonable to assume that the start of sedimentation may be consistent with a crater formation age of about 36 ka. however, the sedimentary deposit in borecore 2 is not continuous. a hiatus of about 3,000 years is present in between a 14c dated sample at 7.11 ka and an overlying tephra horizon correlated by means of chemical analyses (calanchi et al., 1996) to the avellino eruption which occurred at the somma-vesuvius (santacroce, 1987) and has a calibrated 14c age (stuiver and reimer, 1993) of 4.1 ka. another tephra layer occurs at the middle of borecore 2 and it is correlated (calanchi eet al., 1996) 182 fig. 7 a) cross-section of the sediments of the albano lake, reconstructed using seismic reflection and borecore data (c) in chondrogianni et al. (1996). inset b shows the location of the borecores and of the cross-section. a tentative explanation of the lack of sediments younger than 15.8 ka in core 1 and of the ~3 kyr-long hyatus in core 2 is the lake-level fluctuation as reconstructed in the diagram (d) of this figure, using constrains on the minimum water depth given by the sedimentary record of the three borecores. the absence of any volcanic material within the sedimentary record in the three cores spanning the last 25 kyr that can be attributed to activity of the albano maar clearly suggests that no such volcanic activity occurred. a) sezione stratigrafica dei depositi sedimentari del lago di albano, ricostruita in base a dati di sismica a riflessione e carote di sondaggio (c) da chondrogianni et al. (1996). la pozizione dei sondaggi e della sezione è mostrata nel riquadro b. una possibile spiegazione della mancanza di sedimentazione più recente di 15.8 ka nel sondaggio 1, e della presenza di uno hyatus di circa 3 ky nel sondaggio 2 è verosimilmente costituita dalle oscillazioni del livello del lago, così come sono state ricostruite nel diagramma (d) mostrato in figura per mezzo dei vincoli sulla minima profondità dell'acqua forniti dal record sedimentario. l'assenza di qualsiasi prodotto vulcanico attribuibile all'attività albana all'interno dei sedimenti recuperati dai tre sondaggi, che coprono l'intervallo ~25 ka presente, è una chiara indicazione dell'assenza di tale attività. f. marra & d.b. karner to the y-1 tephra layer (keller et al., 1978) which corresponds to the biancavilla-montalto eruprion, whose calibrated 14c age (stuiver and reimer, 1993) is 17 ka. a continuous sedimentary succession is recovered in borecore 3 which spans the time interval 11.5 ka present and includes the tephra layer correlated to the avellino plinian eruption of 4.1 ka. a similar continuous sedimentary record spanning the time interval 10.78 ka present (chondrogianni et al., 1996) is found at the nearby (~3 km to the sw) nemi lake. in this borecore a tephra layer correlated to the avellino plinian eruption of 4.1 ka (calanchi et al., 1996) is also found interbedded within the sedimentary succession. the sedimentary hiatuses (~15 ka present, ~7 ka~4ka) observed within two of the four described borecores can readily be explained by oscillations of the water level within the albano lake (see figure 7). alternative explanations, as those provided in villa et al. (1999) that the hiatuses may be due to draining of the lake by the opening of new craters, seems implausible since no evidence of these hypothesized eruptive events are found in the borecores drilled at albano lake or nemi lake. the only tephra layers recovered from the sedimentary cores from these lakes during the interval 25 ka present, have chemical composition characterized by high sio2 content (>55% in one case, and >59% in the other three cases) and by low cao content (calanchi et al., 1996), which rules out an alban hills origin. all the volcanic products erupted by this volcanic district since 600 ka have sio2 content below 50% and very high cao content (trigila et al., 1995, marra et al., 2003, freda et al., 2005). it seems quite unlikely that any eruptive activity occurred at the albano maar in the time span 25 ka present, without leaving any trace of volcanic deposits within the sediments of the very same crater lake. conclusions detailed stratigraphic and geochronologic studies conducted recently have chronicled the eruptive history for the albano maar. reworked products of the volcanic activity may have been redeposited as lahars in the last 10,000 years, but it remains to be shown that any magmatic activity has occurred in this time span, based on the lack of any crystal younger than 31±3.6 ka in the entire suite of age analyses that we have determined to be primary volcanic material (244 crystals analyzed in 51 single-crystal and 61 multiple-crystal 40ar/39ar age analyses in freda et al., 2005). based on the geochronologic and stratigraphic data, comprising the lack of any volcanic deposit younger than at least 26 ka correlated to the activity of the albano maar in the sedimentary filling of the crater lake, and based on the analysis of the geomorphological and paleoclimatic context that we have discussed, it seems also reasonable to interpret all the sections that have been suggested to host primary and reworked products deposited in the last 23,000 years (funiciello et al., 2002; 2003), to be instead outcrops of distal, syn-eruptive or short-termed post-eruptive products of the activity that took place at the albano maar in the time span 70-36 ka. the only existing geochronologic constraint that allows to ipothesize an emplacement younger than 36 ka for any product (either primary or reworked) of the albano maar relies on two 14c age age determinations of ~5100 kyr on as many paleosoils. however, we point out that 14c dating of poorly developed, shallow seated soils is always susceptible to be affected by problems of contamination. ages of the crystals within the reworked products that rest above the dated soils, when considered within the larger chronostratigraphic framework that we have outlined, suggest that they may be as well, in one case (gra/appia antica) subcoeval with the peperino albano, and in another case (lucrezia romana-casale ferranti) older than the peperino albano. we conclude that more solid evidences should be provided, comprising both direct and indirect dating, in order to demonstrate that any reworked product among those studied at the graappia antica and lucrezia romana sites has an emplacement age younger than 36 ka. on the other hand, assuming that the 14c age on the two soils provided in funiciello et al. (2002) be reliable, it has to be ascertain if the overlying deposits are primary or reworked products. in the latter case, it would testify to the existence of thin (50 to 100 cm) layers of reworked volcaniclastic material locally accumulated within small fluvial incisions at the foot of the alban hills after the holocene climatic optimum, which would imply a simple sedimentary process, rather than catastrophic inundations. completely different would be the case of the identification of primary volcanic products resting above the soils dated by 14c method at 5 ka. in this case the assessment of the reliability of the 14c age becomes a crucial task to establish when (and where) their eruption occurred. however, we point out that, based on the average recurrence time of 45 kyr for the overall activity at the alban hills, an eruption at 5 ka following one at 36 ka would diminish the potential hazard rather than increase it. for the moment, if we rely on the strict definition that is adopted in the smithsonian institution's catalogue of active volcanoes, we believe that further, more detailed studies have to be conducted in order to demonstrate that the albano maar is an active volcano. for this reason we are presently involved in a dedicated research unit within the 2005-2007 gnv-dpc v3_1colli albani sub-project, aimed to clarify the issues discussed above. references ammerman a.j. , miller j., ramsay s. (2000) the midholocene environment of the velabrum in rome, società preistoria protostoria friuli-venezia giulia, trieste, quaderno 8, 9-20. bard e., hamelin b., fairbanks r. (1990) u-th ages obtained by mass spectrometry in corals from barbados: sea level during the past 130,000 years, nature, 346, 456-458. bassinot f.c., labeyrie l.d., vincent e., quidelleur x., shackleton n.j., lancelot y. (1994) the astronomical theory of climate and the age of the brunhes-matuyama magnetic reversal, earth planet. sci. lett., 126, 91-108. calanchi n., dinelli e., lucchini f., mordenti a. (1996) chemostratigraphy of late quaternary sediments 183the albano maar ... from lake albano and central adriatic sea cores (paliclas project), in palaeoenvironmental analysis of italian crater lake and adriatic sediments, p. guillizzoni and f. oldfield ed., mem. ist. ital. idrobiol., 55, 247-263. chondrogianni c., ariztegui d., niessen f., ohlendorf c., lister g.s. (1996) late pleistocene and holocene sedimentation in lake albano and lake nemi (central italy), in palaeoenvironmental analysis of italian crater lake and adriatic sediments, p. guillizzoni and f. oldfield ed., mem. ist. ital. idrobiol., 55, 23-28. de rita d., funiciello r., parotto m. (1988) carta geologica del complesso vulcanico dei colli albani, progetto finalizzato ‘geodinamica’, c.n.r., rome, italy de rita d., faccenna c., funiciello r., rosa c. (1995a) stratigraphy and volcano-tectonics. in: r. trigila (ed.) the volcano of the alban hills. università degli studi di roma "la sapienza", rome italy, pp 33-71. de rita d., giordano g., rosa c., sheridan m.f. (1995b) volcanic hazard at the alban hills and computer simulations. in: r. trigila (ed.) the volcano of the alban hills. università degli studi di roma "la sapienza", rome italy, pp 267-283. freda c., gaeta m., karner d.b., marra f., renne p.r., taddeucci j., scarlato p., christensen j., dallai l. (2005) eruptive history and petrologic evolution of the albano multiple maar (alban hills, central italy), bull. volc., in press. funiciello r., giordano g., de rita d., carapezza m.l., barberi f. (2002) l’attività recente del cratere del lago albano di castelgandolfo. rend. acc. dei lincei, 13, 113-143. funiciello r., giordano g., de rita d. (2003) the albano maar lake (colli albani volcano, italy): recent volcanic activity and evidence of preroman age catastrophic lahar events. j. volcanol. geotherm. res., 123, 43-61. giordano g., de rita d., cas r., rodani s. (2002a) valley pond and ignimbrite veneer deposits in the small-volume phreatomagmatic 'peperino albano' basic ignimbrite, lago albano maar, colli albani volcano, italy: influence of topography. j. volcanol. geotherm. res., 118, 131-144. giordano g., de rita d., fabbri m., rodani s. (2002b) facies associations of rain-generated versus crater lake-withdrawal lahar deposits from quaternary volcanoes, central italy, j. volcanol. geotherm. res., 118, 145-159. guillizzoni p., oldfield f. (ed.) (1996) palaeoenvironmental analysis of italian crater lake and adriatic sediments, mem. ist. ital. idrobiol., 55. karner d.b., renne p.r. (1998) 40ar/39ar geochronology of roman volcanic province tephra in the river tiber valley: age calibration of middle pleistocene sea-level changes. geol. soc. am. bull., 110, 740-747. karner d.b., marra f., renne p.r. (2001a) the history of the monti sabatini and alban hills volcanoes: groundwork for assessing volcanic-tectonic hazards for rome. j. volcanol. geotherm. res., 107, 185-219. karner d.b., lomabardi l., marra f., fortini p., renne p.r. (2001b) age of ancient monuments by means of building stone provenance: a case study of the tullianum, rome, italy. j. archaeol. sc., 28, 387-393. karner d.b., marra f., florindo f., boschi e. (2001c) pulsed uplift estimated from terrace elevations in the coast of rome: evidence for a new phase of volcanic activity? earth. planet. sci. lett., 188, 135-148. keller j., ryan w.b.f., ninkovich d., altherr r. (1978) explosive volcanic activity in the mediterreanean over the past 200,000 yr as recorded in deep-sea sediments. geol. soc. am. bull., 89, 591-604. mcdougall i. & harrison t.m. (1999) geochronology and thermochronology by the 40ar/39ar method, oxford university press, 269 pp. marra f., freda c., scarlato p., taddeucci j., karner d.b., renne p.r., gaeta m., palladino d.m., trigila r., cavarretta g. (2003) 40ar/39ar geochronology of the recent phase of activity of the alban hills volcanic district (rome, italy): implications for seismic and volcanic hazards. bull. volcanol., 65, 227-247. marra f., taddeucci j., freda c., marzocchi w., scarlato p. (2004) eruption recurrence interval of the alban hills and coupling with other volcanic districts of the tyrrhenian margin of italy: possible tectonic influence and implications for volcanic hazard. tectonics, doi 10.1029/2003tc001600. santacroce r. (ed.) (1987) somma-vesuvius. cnr quaderni ricerca scientifica 114 (9), 251. soligo m., tuccimei p., giordano g., funiciello r., de rita d. (2003) new u-series dating of a carbonate level underlying the peperino albano phreatomagmatic ignimbrite (coll i albani, italy). i l quaternario, 16, 115-120. siani g., paterne m., michel e., sulpizio r., sbrana a., arnold m., addad g. (2001) mediterreanean sea surface radiocarbon reservoir age changes since the last glacial maximum, science, 294, 1917-1920. stuiver m. & reimer p.j. (1993) extended 14c data base and revised calib 3.0 14c age calibration program, radiocarbon, 35, 215-230. trigila r., agosta e., currado c., de benedetti a.a., freda c., gaeta m., palladino d.m., rosa c. (1995) petrology. in: r. trigila (ed.) the volcano of the alban hills. università degli studi di roma "la sapienza" rome, 95-165. villa i.m., calanchi n., dinelli e., lucchini f. (1999) age and evolution of the albano crater lake (roman volcanic province). acta vulcanol., 11, 305-310. 184 ms. ricevuto il 17 maggio 2005 testo definitivo ricevuto il 20 settembre 2005 ms. received: may 17, 2005 final text received: september 20, 2005 f. marra & d.b. karner 185 appendix 40ar/39ar data. the third column indicates the number of crystals dated in each laser-fusion age determination. samples in italics were interpreted to contain xenocrysts and were eliminated to reduce the mswd (mean square weighted deviation) to below 1.5a reasonable statistic for a group of ages from an eruptive event (see freda et al., 2005 for details on the procedure). these italicized data were eliminated from the error-weighted mean calculations for each sample above, and were eliminated from the ideogram in fig. 3. dati radioisotopici 40ar/39ar. la terza colonna indica il numero di cristalli impiegati per ottenere le singole età dalla loro fusione laser. i dati in italico si riferiscono a cristalli o gruppi di cristalli interpretati come contaminanti ed eliminati dal calcolo dell'età al fine di ridurre la deviazione quadratica sotto il valore di 1.5, che si considera un valore statistico adeguato ad identificare un singolo evento eruttivo (si veda freda et al., 2005, per i dettagli di questa procedura). i dati in italico sono stati eliminati dal calcolo della media pesata per ogni età dei campioni e dall'ideogramma in figura 3. lab.no. sample id # of crystals age (ma) ± 1σd samples included in the youngest population 33135-01 ah-4fbis 1 0,0371 0,0013 33135-02 ah-4fbis 1 0,0358 0,0014 33135-03 ah-4fbis 1 0,0329 0,0011 33135-04 ah-4fbis 1 0,0333 0,0011 33135-05 ah-4fbis 1 0,0358 0,0012 33135-06 ah-4fbis 1 0,0355 0,0011 weighted mean (4) 0,0359 0,0006 11375-01 ah18-c2 2 0,0358 0,0002 11375-02 ah18-c2 2 0,0363 0,0003 11375-03 ah18-c2 2 0,0363 0,0003 11375-04 ah18-c2 2 0,0356 0,0004 11375-05 ah18-c2 2 0,0357 0,0003 11383-01 gra-c2bis 2 0,0375 0,0005 11383-02 gra-c2bis 2 0,0367 0,0005 11383-03 gra-c2bis 2 0,2226 0,0009 11383-04 gra-c2bis 2 0,0387 0,0013 11383-05 gra-c2bis 2 0,0398 0,0008 11383-06 gra-c2bis 2 0,0374 0,0004 11383-07 gra-c2bis 2 0,0448 0,0011 weighted mean (8) 0,0360 0,0001 11075-01 mam-01 8 0,0406 0,0040 11075-02 mam-01 8 0,0445 0,0037 11075-03 mam-01 8 0,0334 0,0024 11075-04 mam-01 8 0,0324 0,0025 11075-05 mam-01 8 0,0370 0,0044 11075-06 mam-01 8 0,0345 0,0037 11075-07 mam-01 8 0,0392 0,0031 11075-08 mam-01 8 0,0315 0,0039 weighted mean (8) 0,0357 0,0011 33805-01 ah17-c3 1 0,0463 0,0009 33805-02 ah17-c3 1 0,0372 0,0013 33805-03 ah17-c3 1 0,0325 0,0037 33805-04 ah17-c3 1 0,0354 0,0005 33805-05 ah17-c3 1 0,0390 0,0008 33805-06 ah17-c3 1 0,0376 0,0014 33805-07 ah17-c3 1 0,0352 0,0013 33805-08 ah17-c3 1 0,0380 0,0006 33805-09 ah17-c3 1 0,0372 0,0012 33805-10 ah17-c3 1 0,0384 0,0006 33805-11 ah17-c3 1 0,0348 0,0009 33805-12 ah17-c3 1 0,0483 0,0016 33805-13 ah17-c3 1 0,0362 0,0009 33805-14 ah17-c3 1 0,0410 0,0007 33805-15 ah17-c3 1 0,0343 0,0020 33805-16 ah17-c3 1 0,0512 0,0015 33805-17 ah17-c3 1 0,0373 0,0009 33805-18 ah17-c3 1 0,0398 0,0017 33805-19 ah17-c3 1 0,0368 0,0011 33805-20 ah17-c3 1 0,0420 0,0005 weighted mean (12) 0,0361 0,0003 11391-01 ah19-c1bis 1 0,2986 0,0009 11391-02 ah19-c1bis 1 0,3170 0,0008 11391-03 ah19-c1bis 1 0,3533 0,0011 11391-04 ah19-c1bis 1 0,0390 0,0006 lab.no. sample id # of crystals age (ma) ± 1σd 11391-05 ah19-c1bis 1 0,0381 0,0003 11391-07 ah19-c1bis 1 0,3594 0,0013 weighted mean (2) 0,0382 0,0003 11374-01 ah19-c2 2 0,0402 0,0004 11374-02 ah19-c2 2 0,0380 0,0003 11374-03 ah19-c2 2 0,0397 0,0005 11374-04 ah19-c2 2 0,0405 0,0007 11374-05 ah19-c2 2 0,0402 0,0006 11374-06 ah19-c2 3 0,0390 0,0003 weighted mean (5) 0,0388 0,0002 11376-01 ah18-c3 3 0,0389 0,0007 11376-02 ah18-c3 3 0,0381 0,0005 11376-03 ah18-c3 3 0,0441 0,0003 11376-04 ah18-c3 3 0,0383 0,0005 11376-05 ah18-c3 3 0,0399 0,0005 11376-06 ah18-c3 3 0,0395 0,0005 weighted mean (4) 0,0390 0,0003 33136-01 ah3-c14 1 0,0396 0,0017 33136-02 ah3-c14 2 0,0392 0,0030 33136-03 ah3-c14 5 0,0442 0,0021 33136-04 ah3-c14 3 0,0405 0,0012 33136-05 ah3-c14 4 0,0473 0,0023 33136-06 ah3-c14 3 0,0421 0,0020 weighted mean (5) 0,0409 0,0008 33132-01 ah3-c12l 1 0,0397 0,0040 33132-02 ah3-c12l 1 0,0431 0,0013 33132-03 ah3-c12l 1 0,3571 0,0023 33132-04 ah3-c12l 1 0,0398 0,0016 33132-05 ah3-c12l 1 0,0437 0,0018 33132-06 ah3-c12l 1 0,0498 0,0024 33132-07 ah3-c12l 1 0,0435 0,0010 33132-08 ah3-c12l 1 0,0568 0,0015 weighted mean (3) 0,0412 0,0011 33137-01 ah3-c9 2 0,0679 0,0021 33137-02 ah3-c9 3 0,0686 0,0020 33137-03 ah3-c9 4 0,0719 0,0020 33137-04 ah3-c9 3 0,0534 0,0124 33137-05 ah3-c9 5 0,0689 0,0072 33137-06 ah3-c9 4 0,0629 0,0035 weighted mean (6) 0,0686 0,0011 11385-01 ah18-c1 2 0,0697 0,0009 11385-02 ah18-c1 2 0,0707 0,0006 11385-03 ah18-c1 2 0,0698 0,0004 11385-04 ah18-c1 2 0,0682 0,0005 11385-05 ah18-c1 1 0,0688 0,0004 weighted mean (4) 0,0689 0,0002 11334-01 ah-3a 1 0,0702 0,0012 11334-02 ah-3a 1 0,0690 0,0012 11334-03 ah-3a 1 0,0676 0,0020 11334-04 ah-3a 1 0,0678 0,0017 11334-05 ah-3a 1 0,0721 0,0015 weighted mean (5) 0,0694 0,0006 the albano maar ... amq29(2) 7 villa 193-199nag.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 29 (2), 2016, 193 199 the long sedimentary succession of the valle giumentina basin (abruzzo, central italy): new evidence from stratigraphic studies and electrical resistivity tomography (ert) valentina villa1,2,3, clément virmoux1, christine chaussé4, jean-philippe degeai5, vincent robert6, catherine kuzucuoglu1, giovanni boschian3, silvano agostini7, daniele aureli8,9, marina pagli9, elisa nicoud10 1 umr 8591 cnrs/paris 1 lgp, meudon, france 2 école française de rome, roma, italy 3 dipartimento di biologia, universita degli studi di pisa, pisa, italy 4 inrap, paris, france 5 umr 5140 cnrs asm, lattes, france 6 ipgp ovsg, le hoüelmont, guadeloupe 7 soprintendenza archeologia dell’abruzzo, chieti, italy 8 dip. di scienze fisiche, della terra e dell’ambiente, università di siena, siena, italy 9 umr 7041 arscan, antet, nanterre, france 10 umr 7264 cnrs cepam, nice, france corresponding author: e. nicoud <elisa.nicoud@cepam.cnrs.fr> abstract: we carried out a multidisciplinary study on the sedimentary succession of valle giumentina, a small intermountain basin located in the central apennine. studied in the 1950s, this 70 m-thick succession, including nine palaeolithic occupation layers, was considered to be of rissian and würmian age. however, recent 40ar/39ar geochronological and tephrochronological investigations constrained the sedimentary history of the whole succession to the mis 15-mis 12 interval (villa et al. 2016). geophysical investigations (electrical resistivity tomography) allow detecting the contact between bedrock and quaternary infilling of the basin. no master fault was identified along the flank of the basin, suggesting that tectonics played a marginal role in the formation and evolution of the basin. indeed, the basin sedimentary processes appear to be mainly climate-driven, with the deposition of glacio-fluvial sediments during colder glacial periods of mis 14 and mis 12 and alluvial sedimentation and/or pedogenesis processes active during warmer interglacial (mis 15 and mis 13) and interstadial phases (during mis 12). based on the available chronological data, the capture of the basin by a tributary stream of the san bartolomeo canyon and its definitive extinction, occurred in mis 12 glacial; i.e., when the uplift of the apennine chain induced the reorganisation of the regional drainage system and the capture of almost all the lakes hosted in the intermountain basins. keywords: middle pleistocene; central apennine; intermountain basin; electrical resistivity tomography 1. introduction valle giumentina is a small hanging valley located at 740 m a.s.l on the adriatic side of the central apennine, on the north-western slope of the majella massif (fig. 1a and 1b). the valley spreads over 1 km2 with a ne-sw axis and it is bordered by two perpendicular gorges to the north and to the south, san bartolomeo and orfento, respectively (fig. 1c). during the quaternary this small karstic-alluvial basin was filled by a succession (70 m-thick) of alluvial and lacustrine/palustrine deposits, then deeply incised by a sw-ne tributary stream of the san bartolomeo, which exposed in its northern portion the uppermost 25 mthick section (fig. 1c). the 1953-54 archaeological excavations carried out by a.m. radmilli and j. demangeot revealed nine lower palaeolithic occupation layers attributed to clactonian, acheulian and levalloisian (demangeot & radmilli, 1953). on the basis of the typological characteristics of the lithic assemblages and of the stratigraphic study of the basin infilling, demangeot & radmilli (1953; 1966) suggested to attribute the archaeological layers to the period between the riss and würm glacials. since then, the site is considered a key reference for the definition of the italian lower palaeolithic cultural evolution. valle giumentina thus represents an exceptional archive documenting the middle pleistocene evolutionary history of both palaeoenvironment and palaeolithic human groups. archaeological excavations funded by the école française de rome started in 2012 (nicoud et al., 2016 and references therein). at the same time a multidisciplinary study of the basin infilling (sedimentology, geochemistry, biomarkers, geochronology) was carried out to reconstruct the palaeoenvironmental and climatic evolution of the site during the quaternary and to determine the chronology of the palaeolithic settlements (villa et al., 2016). in this paper we present the results of geophysics surveys we performed in the valley with the aim work presented during the aiqua scientific conferences "waiting for the nagoya inqua xix congress", held in florence, june 18 19, 2015 194 villa v. et al. of defining the global geological setting of the site, the geometry of the basin and of its infilling. we provide for the first time an electrical image of the deep structure of valle giumentina and describe the distribution and depositional architecture of the lithostratigraphic units in the subsurface. these results allow a better comprehension of the site formation for environmental reconstructions. 2. geological and geomorphological context the apennines are a nw-se neogene fold and thrust belt, characterised by mesozoic-cenozoic calcareous ridges alternating with valleys and/or wide intermountain basins (doglioni et al., 1994; patacca et al., 1990; patacca and scandone, 1989). the formation of these basins was led by normal faulting, which affected the chain since the upper pliocene, at the same time of its uplift (bosi et al., 2003; galadini & galli, 2000). during the quaternary, some of these basins hosted large lakes and were filled by long and complex sedimentary successions (e.g. amato et al., 2014; giaccio et al., 2015; russo ermolli, 1994). as a consequence of the regional uplift, during the late middle pleistocene, regressive fluvial incision, from the coast toward the axial zone of the apennines, determined the progressive capture of the basins. hence, the infilling of most of them was partially eroded by fluvial incisions, which in turn were partially filled by fluvial deposits, leading to a system of terraced deposits (bartolini et al., 2003; d’alessandro et al., 2003; miccadei et al., 1998). these well preserved stratigraphic successions thus represent precious records of the past environmental and climatic changes. 3. methods 3.1. field surveys and stratigraphic analyses field investigations were carried out in the northern sector of the valle giumentina basin, where the stream incision allows the direct observation of the uppermost ~25 m-thick interval of the sedimentary infilling. a 17 mlong stratigraphic profile named vv1 was established on the left side of the valley, in connection with the archaeological excavation area (fig. 1c and 1d). a borehole (vg1) was drilled 30 m north of the vv1 profile (fig. 1d). it reached the base of the quaternary infilling at a depth of 45 m. the vv1 profile and the vg1 core were sampled for sedimentological and geochemical analyses, biomarkers studies (pollen and molluscs) and geochronology (40ar/39ar dating) (villa et al., 2016). 3.2. geophysics geophysical investigations were realised to complete the stratigraphic analyses. the electrical resistivity tomography (ert) was used to image the contact between the limestone substratum and the basin infilling and characterize the sedimentary architecture of the latter. the pole-dipole protocol was used to allow an adequate depth of investigation while keeping a good resolution. a 64 electrodes terrameter abem ls system was used for field data acquisition with an interelectrode spacing of 5 meters. electrical resistivity measurements were realised along two ne-sw longitudinal profiles (p2 and p4) and two nw-se cross-section fig. 1 reference map and view of valle giumentina. (a): location of the abruzzo region (in black). (b) location of the valle giumentina basin. (c) aerial view of the basin and location of the stratigraphic records studied; the quaternary infilling of the basin is highlighted in yellow. (d) aerial view of the basin and location of the ert profiles, of the vv1 profile and of the vg1 core. 195 valle giumentina basin (abruzzo, central italy): stratigraphy and ert profiles (p1 and p3) (fig. 1d). profiles length range between 315 and 555 m. the acquired ert data were processed using the res2dinv software (loke & barker, 1996). 4. results 4.1. stratigraphy the stratigraphic study of both the vg1 and the vv1 profile allowed the identification of 5 main sedimentary units (su), named su1 to su5, which were further subdivided into 40 stratigraphic sub-units (fig.2). correlations between the vg1 and vv1 profiles were established thanks to the presence of some lithostratigraphic markers, such as coarse detrital layers (cgb2 and cgb1), palaeosols and tephra layers (fig. 2). the lower unit, su5, is formed by a thick fluvial gravel deposit, which overlies the miocene limestone bedrock. unit su4, consisting of lacustrine and palustrine calcareous sediments, attests the formation of a shallow lake. oxidation, bioturbation and pedogenic processes characterise these deposits, testifying repeated oscillations of the water table, subaerial exposure and alteration of the sediments. detrital input from the basin catchment is progressively weaker towards the top of the unit, where the sediments show almost no traces of alteration or desiccation. unit su3 is formed by clayey organic deposits, which attest the evolution from lacustrine to marshy environments. the upper part of the unit (layer ao2-ao1; fig. 2) shows an abrupt transition to coarser sediments, rich in caco3. three grey sandy layers of volcanoclastic material (named sg3, sg2 and sg1) are interbedded with the organic deposits of the su3 unit. unit en2 mainly consists of fine detrital calcareous deposits characterised by planar bed laminations. mottled carbonates are frequent at the base of the unit, but they are progressively replaced by calcareous silts and clay showing no traces of alteration and comprising some pyrite framboids and fragments of molluscs. three additional tephra layers (ln, lan2 and lan1; fig. 2) were identified in this unit. the transition to unit su1 is marked by an abrupt lithological change represented by coarse alluvial layer (cgb2). the overlying deposits are mainly formed of sandy/silty sediments, characterised by planar and/or crossed lamination. these fine detrital deposits are interbedded with four palaeosols. the succession ends fig. 2 vg1 core and vv1 profile successions and position of key layers (archaeological levels and tephra layers). the possible correlations with the palaeoclimatic marine record from lr04 stack (lisiecki and raimo, 2005) are also shown. note that the temporal scale between 400 ka and present is contracted. with one thick layer of heterometric limestone boulders (cgb1) and a red clayey-sandy colluvium deposit (ar; fig. 2). 4.2. geophysics the electrical resistivity tomography (ert) results were calibrated using the stratigraphic succession of the vg1 core, which reached the limestone bedrock at 43.68 m-depth. the 2d ert pseudosections show five main units (fig. 3 and 4). the first thin unit (a), observed in the p1, p2 and p3 profile, has resistivity values ranging between 15 and 40 ω ·m. its thickness is irregular, comprised between <1 and 2 meters. unit a corresponds to the topsoil and the colluvium layer ar, which were identified in both the vg1 core and the vv1 profile (fig. 2). it is visible along the whole left bank of valle giumentina, where it actually shows an abrupt wavy contact with the underlying layers. the second unit (b), in green, has resistivity values ranging between 50 and 200 ω ·m. it is visible in all the profiles (fig. 3 and 4). in p1 its thickness varies between 4 and 20 m, being thicker in the centre of the basin and progressively thinner toward its margin. in p2, it is disconnected from the northern limit of the basin and becomes progressively thinner southward. in p3, it appears to be disconnected from the western basin slopes and show an almost vertically cut at 70 m from the eastern margin of the basin, corresponding to the bed of a tributary stream of the san bartolomeo canyon. in p4 it is visible in the northern part of the profile, where it is 5 m-thick and gradually becomes thinner, stopping at ~80 m from the northern limit of the profile. this unit corresponds to the coarse detrital calcareous layers cgb1 and cgb2 (fig. 2). the ert does not distinguish considerable lithological differences in the deposits at depths between 4.5 and 8 m, but the stratigraphic succession of the vg1 core clearly shows three lithologically different segments at this location, with fine-grained deposits comprised between the two units cgb1 and cgb2 (fig. 2). furthermore, the whole thickness of these two coarse-grained layers appears to be overestimated (15 m instead of 10 m in the vg1 core location). this is probably due to a combination of factors, such as (i) the low resolution of the electrical resistivity measures, (ii) the compression of the deposits during the extraction of the core and (iii) the gradual transition between these coarse units and the overlying layer (ar), which is rich in detrital blocs and gravels. the third unit (c), in blue, is more conductive, with values of resistivity ranging from 1 to 20 ω ·m (fig. 3 and 4). it corresponds to the fine sediments forming the lower portion of the quaternary infilling of the basin (lithostratigraphic units en3 and en4; fig. 2). its thickness varies from a few meters in the external sector of fig. 3 electrical resistivity tomographies carried out across the valle giumentina basin, transverse profiles p1 and p3. locations in fig. 1b. 196 villa v. et al. f ig . 4 e le ct ric al r es is tiv ity to m og ra ph ie s ca rr ie d ou t a cr os s th e v al le g iu m en tin a ba si n, lo ng itu di na l p ro fil es p 2 an d p 4. l oc at io ns in f ig . 1 b. 197 valle giumentina basin (abruzzo, central italy): stratigraphy and ert the basin to >20 m in its centre, reaching maximum values, >40 m, in the depocentre of p3, located at 130 m from the western limit of the profile. the fourth unit (d), corresponding to the limestone bedrock, has resistivity values comprised between 2500 and >10000 ω ·m (fig. 3 and 4). in the cross-section profiles the bedrock rises to the surface in both the western and eastern area and is characterised by steep margins. the bottom of the basin appears to be slightly asymmetric in p3, where the depocentre is located in the western sector (fig. 3). the longitudinal profiles p2 and p4 show a flat bottom and the progressive gentle raising of the limestone both in the northern and southern sector. in p4, at ~320 m, an abrupt discontinuity of the bedrock is visible (fig. 4). it is filled by a less resistant unit (e), characterised by resistivity values ranging between 50 and 200 ω ·m (fig. 4). this could correspond to a fault dissecting the bedrock or to a karstic depression, i.e., a sinkhole, filled by coarse detrital deposits and surrounded by strongly fissured limestone. further investigations are needed to understand the geological mean of this abrupt discontinuity. on the whole, the ert pseudosections provide a good expression of the overall geometry of the basin and of its infilling, up to a depth of 80 m. the geophysical signature of the contact between the quaternary clastic sediments and the bedrock is marked by a shift of resistivity from 20 ω ·m to around 2500 ω ·m. the basin is 800 m long and between 330 m and 380 m large. the shape of the basin is slightly asymmetric and the maximum sediment thickness (~70 m) occurs along the north-western margin. the presence of extremely conductive horizons (units a and c) is related with finegrained sediments, whilst the high-resistivity zones can be associated to coarser deposits (unit b and e) and to the limestone bedrock (unit d). 5. conclusion the results of the integrated geological study performed on the valle giumentina sedimentary sequence allow to reconstruct the environmental evolution of the basin during the quaternary (see detail in villa et al., 2016). the sedimentary sequence covers a time span of about 150 ka, from 618 ±13 ka to 456 ±2 ka and includes two complete interglacial-glacial cycles, between mis 15 and mis 12. after the deposition of a thick fluvial conglomerate (su5) occurred between the end of the mis 16 and the beginning of mis 15 (after 618 ±13 ka and before 586 ±9 ka), the basin hosted a shallow lake (su4). then, during mis 15 the lacustrine sedimentation was replaced by the development of marshy environments, indicated by su3. this thick sedimentary unit, consisting of organic sediments, records the evolution towards a strong cooling, corresponding to the transition from mis 15 to mis 14. another ephemeral lacustrine phase is attested by su2, characterised by several phases of drying and concurrent development of pedogenic horizons. two 40ar/39ar dates (556 ±6 ka and 531 ±5 ka) correlate this phase to mis 14 and mis 13. the definitive transition to exclusively sub-aerial depositional environments is attested by the topmost unit su1, which correspond to mis 12. particularly relevant is the occurrence of a till deposit (cgb1), as it indicates a significant expansion of glaciers during the mis 12 glacial, possibly reaching the relatively low altitude of the site. the ert pseudosections show that this deposit (corresponding to the resistivity unit b) is present in the whole northern sector of the basin and its geometry suggests a deposition from the eastern slope. our results highlighted that the sedimentary dynamic in the valle giumentina basin was strongly conditioned by climatic changes. the valle giumentina succession records glaciofluvial-lacustrine sedimentation during glacial periods and alluvial sedimentation or pedogenic processes during interglacials. we excluded any major role of local tectonics in the evolution of the basin during the middle pleistocene. these conclusions are confirmed by the ert data. no master faults have been identified along the flanks of the basin and the quaternary infilling doesn’t show any dissection or perturbations which could suggest the existence of synsedimentary faults. one fault is possibly present in the southern part of the basin, but we suggest excluding any major role of local tectonics in the formation and evolution of the basin, which seems to be rather of karstic origin. however, tectonic processes were responsible for the basin capture resulting from the general regional uplift which affected the whole apennine chain since the second half of the middle pleistocene. indeed, the majority of the apennine intermountain basins record almost simultaneously a transition from lacustrine to fluvial environments and are definitively captured during mis 12 (e.g. giaccio et al., 2014; petrosino et al., 2014; robustelli et al., 2014; russo ermolli et al., 2010, 2015). based on the available data (villa et al., 2016), the valle giumentina basin was captured almost at the same time and thus, the till deposit of layer cgb1 could be correlated to the mis 12 glacial. after the capture of the basin, the tributary stream of the san bartolomeo canyon progressively migrated northward and deeply incised the quaternary deposits until the limestone bedrock. acknowledgments the phd project of valentina villa (paris 1 university and pisa university joint supervision) is granted by the école française de rome (french ministry of education and research) with a contribution of the université franco italienne. the pluridisciplinary research project at valle giumentina is carried on by the école française de rome and the soprintendenza archeologia dell’abruzzo. it is also supported by the parco nazionale della majella and the fondazione pescarabruzzo as well as the cities of abbateggio and caramanico terme (pescara). references amato v., aucelli p.p.c., cesarano m., jicha b., lebreton v., orain r., pappone g., petrosino p., russo ermolli e. (2014) quaternary evolution of the largest intermontane basin of the molise apennine (central-southern italy). rendiconti lincei, 25, 197-216. doi:10.1007/s12210-014-0324-y 198 villa v. et al. bartolini c., d’agostino n., dramis f. (2003) topography, exhumation, and drainage network evolution of the apennines. episodes, 26, 212–216. bosi c., galadini f., giaccio b., messina p., sposato a. (2003) plio-quaternary continental deposits in the latium-abruzzi apennines: the correlation of geological events across different intermontane basins. il quaternario, 16, 55-76. d’alessandro l., miccadei e., piacentini t. (2003) morphostructural elements of central-eastern abruzzi: contributions to the study of the role of tectonics on the morphogenesis of the apennine chain. quaternary international, 101, 115-124. demangeot j., radmilli a.m. (1953) le gisement quaternaire de la valle giumentina (abruzzes adriatiques), stratigraphie et palethnologie. contributi di scienze geologiche, suppl. a la ricerca scientifica, 3, 11-123. demangeot j., radmilli a.m. (1966) le gisement paléolithique de valle giumentina (appennin central) et ses problèmes. eiszeitalter und gegenwart, 17, 159-199. doglioni c., mongelli f., pieri p. (1994) the puglia uplift (se italy): an anomaly in the foreland of the apenninic subduction due to buckling of a thick continental litosphere. tectonics, 13, 1309-1321. galadini f., galli p. (2000) active tectonics in the central apennines (italy) input data for seismic hazard assessment. natural hazards, 22, 225-268. giaccio b., galli p., peronace e., arienzo i., nomade s., cavinato g.p., mancini m., messina p., sottili g. (2014) a 560-440 ka tephra record from the mercure basin, southern italy: volcanological and tephrostratigraphic implications. journal of quaternary science, 29, 232-248. doi:10.1002/jqs.2696 giaccio b., regattieri e., zanchetta g., wagner b., galli p., mannella g., niespolo e., peronace e., renne p.r., nomade s., cavinato g.p., messina p., sposato a., boschi c., florindo f., marra f., sadori l. (2015) a key continental archive for the last 2 ma of climatic history of the central mediterranean region: a pilot drilling in the fucino basin, central italy. scientific drilling, 20, 13-19. doi:10.5194/sd-20-13-2015 loke m.h., baker r.d. (1996) practical techniques for 3d resistivity surveys and data inversion. geophysical prospecting, 44, 499-523. miccadei e., barberi r., cavinato g.p. (1998) la geologia quaternaria della conca di sulmona (abruzzo, italia centrale). geologica romana, 34, 59-86. nicoud e., aureli d., pagli m., villa v., chaussé c., agostini s., bahain j.j., boschian g., degeai j.p., fusco f., others (2016) preliminary data from valle giumentina pleistocene site (abruzzo, central italy): a new approach to a clactonian and acheulian sequence. quaternary international, 409, part b, 182-194. patacca e., sartori r., scandone p. (1990) tyrrhenian basin and apenninic arcs: kinematic relations since late tortonian times. memorie della società geologica italiana, 45, 425-451. patacca e., scandone (1989) post-tortonian mountain building in the apennines, the role of the passive sinking of a relic lithosphere. in: boriani, a., bonafede, m., piccardo, g.b., vai, g.b. (eds.), the litosphere in italy, accademia nazionale dei lincei. presented at the advances in earth sciences research, rome, 157-176. petrosino p., jicha b.r., mazzeo f.c., russo ermolli e. (2014) a high resolution tephrochronological record of mis 14–12 in the southern apennines (acerno basin, italy). journal of volcanology and geothermal research, 274, 34-50. doi:10.1016/j.jvolgeores.2014.01.014 robustelli g., russo ermolli e., petrosino p., jicha b., sardella r., donato p. (2014) tectonic and climatic control on geomorphological and sedimentary evolution of the mercure basin, southern apennines, italy. geomorphology, 214, 423-435. doi:10.1016/j.geomorph.2014.02.026 russo ermolli e. (1994) analyse pollinique de la succession lacustre pléistocène du vallo di diano (campanie, italie). annales de la société géologique de belgique, 117, 333-354. russo ermolli e., aucelli p.p.c., di rollo a., mattei m., petrosino p., porreca m., rosskopf c.m. (2010) an integrated stratigraphical approach to the middle pleistocene succession of the sessano basin (molise, italy). quaternary international, palaeobotanical and palynological records from italy, 225, 114-127. doi:10.1016/j.quaint.2009. 04.008 russo ermolli e., di donato v., martín-fernández j.a., orain r., lebreton v., piovesan g. (2015) vegetation patterns in the southern apennines (italy) during mis 13: deciphering pollen variability along a nw-se transect. review of palaeobotany and palynology, 218, 167-183. doi:10.1016/j.revpalbo.2014.11.004 villa v., chaussé c., nicoud e., aureli d., pagli m. (2015) valle giumentina (abruzzes, italie). nouvelles observations de la stratigraphie. mélanges de l’école française de rome-antiquité, 127 (1). villa v., pereira a., chaussé c., nomade s., giaccio b., limondin-lozouet n., fusco f., regattieri e., degeai j.-p., robert v., kuzucuoglu c., boschian g., agostini s., aureli d., pagli m., bahain j.j., nicoud e. (2016) a mis 15-mis 12 record of environmental changes and lower palaeolithic occupation from valle giumentina, central italy. quaternary sciences reviews, 151, 160-184. doi:10.1016/j.quascirev.2016.09.006 ms. received: april 7, 2016 final text received: september 30, 2016 199 valle giumentina basin (abruzzo, central italy): stratigraphy and ert 200 << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /none /binding /left /calgrayprofile (dot gain 20%) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /error /compatibilitylevel 1.4 /compressobjects /tags /compresspages true /convertimagestoindexed true /passthroughjpegimages true /createjobticket false /defaultrenderingintent /default /detectblends true /detectcurves 0.0000 /colorconversionstrategy /cmyk /dothumbnails false /embedallfonts true /embedopentype false /parseiccprofilesincomments true 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/hrv (za stvaranje adobe pdf dokumenata najpogodnijih za visokokvalitetni ispis prije tiskanja koristite ove postavke. stvoreni pdf dokumenti mogu se otvoriti acrobat i adobe reader 5.0 i kasnijim verzijama.) /hun 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can be opened with acrobat and adobe reader 5.0 and later.) >> /namespace [ (adobe) (common) (1.0) ] /othernamespaces [ << /asreaderspreads false /cropimagestoframes true /errorcontrol /warnandcontinue /flattenerignorespreadoverrides false /includeguidesgrids false /includenonprinting false /includeslug false /namespace [ (adobe) (indesign) (4.0) ] /omitplacedbitmaps false /omitplacedeps false /omitplacedpdf false /simulateoverprint /legacy >> << /addbleedmarks false /addcolorbars false /addcropmarks false /addpageinfo false /addregmarks false /convertcolors /converttocmyk /destinationprofilename () /destinationprofileselector /documentcmyk /downsample16bitimages true /flattenerpreset << /presetselector /mediumresolution >> /formelements false /generatestructure false /includebookmarks false /includehyperlinks false /includeinteractive false /includelayers false /includeprofiles false /multimediahandling /useobjectsettings /namespace [ (adobe) (creativesuite) (2.0) ] /pdfxoutputintentprofileselector /documentcmyk /preserveediting true /untaggedcmykhandling /leaveuntagged /untaggedrgbhandling /usedocumentprofile /usedocumentbleed false >> ] >> setdistillerparams << /hwresolution [2400 2400] /pagesize [612.000 792.000] >> setpagedevice amq_27(2) def 14 b manca contr revisori available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 27 (2), 2014, 77 84 tephrostratigraphy of marine core ad91-17 (adriatic sea) revised greta marchini1, giovanni zanchetta1,2,3,4, roberto santacroce1, luigi vigliotti5, lucilla capotondi5, roberto sulpizio6, 7 1 dipartimento di scienze della terra, university of pisa, pisa, italy 2 istituto di geoscienze e georisorse cnr, pisa, italy 3 istituto nazionale di geofisica e vulcanologia sez. pisa, italy 4 istituto geologia ambientale e geoingegneria cnr montelibretti, rome, italy 5 istituto di scienze marine cnr, bologna, italy 6 dipartimento di scienze della terra e geoambientali, università di bari, bari, italy 7 istituto per la dinamica dei processi ambientali cnr, milan, italy corresponding author: g. zanchetta <zanchetta@dst.unipi.it> abstract: revision of the tephrostratigraphy previously proposed for the marine core ad91-17 (adriatic sea), supported by energydispersive-spectrometry (eds) chemical data, has allowed to challenge previous interpretation and proposed a core chronology on the basis of new tephrochronological data. four different tephra layers were identified and correlated with known eruption from southern italian volcanoes. the upper tephra layer was tentatively correlated with ad 1631eruption from somma-vesuvius, specifically using chemical composition of pyroxenes. the second one (actually represented by two distinct layers), due to pervasive alteration of glass shards, is difficult to be correlated even if is attributed to somma-vesuvius volcano. close to sapropel s1 interruption a rhyolitic layer was correlated to e1/gabellotto-fiumebianco eruption from lipari (aeolian islands). the lowermost tephra layers are correlated to the mercato eruption (somma-vesuivus). this seems to confirm the multiple occurrence of mercato distal deposits in distal areas, as testified by other findings in mediterranean cores. this suggests that this eruption is probably more complex than previously hypothesised, and characterised by at least two phases fed by the same phonolitic magma. keywords: tephrostratigraphy, adriatic core, holocene, vesuvius. 1. introduction tephrostratigraphy is a volcanology-quaternary science cross-field method that deals with the detailed study of volcanic successions and ash layers in quaternary archives and their correlation with parental eruptions or known distal tephra. the study of tephra layers in distal setting is an important source of information for the study of volcanic ash dispersion, for dating and correlating stratigraphic successions and events in paleoclimatology and archaeological researches (lowe, 2011). the mediterranean region with a remarkable explosive volcanic activity characterised by an unique wide chemical compositional variability (peccerillo, 2005), is an ideal area for tephrostratigraphic study (e.g. keller et al., 1978; paterne et al., 1988, 2008; narcisi & vezzoli, 1999; siani et al., 2004; sulpizio et al., 2010b; zanchetta et al., 2011; giaccio et al., 2012; insinga et al., 2014). the aim of this paper is to study the tephra layers found in ad91-17 core (fig. 1), proposing an accurate correlation to parental eruptions and improving the core chronology proposed by sangiorgi et al. (2003), partly based on stratigraphic position of the tephra layers in the core but not supported by tephra composition data. 2. study area and core description core ad91-17 was collected in the south adriatic sea (40°52.17 n, 18°38.15 e), during the ad91 cruise, performed by the r/v minerva from 5 to 21 march 1991, at a depth of 844 m below sea level. (fig. 1). the area is well suited to recognizing explosive activity because of its downwind position and proximity to the southern italian volcanoes (siani et al., 2004; caron et al., 2012). indeed, in the central mediterranean the dominant wind direction is w-e, and in some case wene (barberi et al., 1991; sulpizio et al., 2008). the core has a total length of 330 cm (fig. 2). it consists of olive-grey hemipelagic mud from the base to 200 cm, interbedded by two turbiditic layers (t1: 200-196 cm and t2: 318-307 cm). according to giunta et al. (2003) t1 coincides with a hiatus, which probably comprises part of the late glacial, including the younger dryas. instead, the sapropel s1 is recognized from 190 to 125 fig. 1 core location and position of other cores quoted in the text. 78 cm. it shows laminations and a grey colour. from 160 to 156 cm there is a massive lighter interval corresponding to the sapropel interruption and from 125 cm to the core top the lithology consists of olive-grey hemipelagic mud (giunta et al., 2003). multiproxy studies have been carried out on the ad91-17 core (jorissen, 1999; capotondi and morigi, 1996; capotondi et al., 1999; vigliotti et al., 2011). in the frame of this work it is useful to mention the palaeomagnetic study, which has included the magnetic susceptibility, natural remnant magnetisation (nrm) and the anhysteretic remanence (arm) measurement (vigliotti et al., 2011). chronology of the core has been based on five accelerator mass spectrometry (ams) 14c ages. further indirect chronological constraints for the basal part of the core ad91-17, were based on its correlation with globigerina bulloides δ18o record from core md90-917 (south adriatic sea) (sangiorgi et al., 2003; giunta et al., 2003), which was dated by means of a higher number of 14c ams dates (siani et al., 2001). the same climatic expression and similar δ18o were recognized in the two cores, which were collected very close to each other (giunta et al., 2003). in the study of sangiorgi et al. (2003) 3 tephra layers have been identified by visual inspection at a depth of 1, 170 and 195 cm. an additional tephra (a1 in giunta et al., 2003) was closely dated by radiocarbon but no correlation was proposed. based on their stratigraphic position and by comparison with other cores, the former three layers were attributed to known eruptions from the campanian area. considering the dispersal axis of the tephras and the 14c dating, they have been correlated to the agnano pomici principali eruption of campi flegrei (195 cm), to the mercato-ottaviano eruption from somma-vesuvius (170 cm) and to the ad 472 eruption of somma-vesuvio (1 cm). two magnetic susceptibility peaks were found at 39 and 73 cm and have been associated respectively to “avellino” eruption from somma-vesuvius (sulpizio et al., 2010a) tephra and “agnano monte spina” tephra from campi flegrei (e.g. di vito et al., 1999). however, none of these latter peaks were used as chronological tie points (sangiorgi et al., 2003). from figure 2 it is possible to observe that there is no an obvious correlation between tephra layers and the magnetic susceptibility peak and from a methodological point of view it is important to stress that the correlations were not based on any chemical analysis. 3. material and methods for this work we used seven samples, previously sieved at 63 μm for micropaleontological studies, at 1 cm, 41 cm, 45 cm, 171 cm, 191 cm, 196 cm and 321 cm of depth. the samples were selected under binocular microscope on the basis of the observed glass shards, scoriae and lithic abundances. then, the samples were embedded in epoxy resin, polished and screened for glass shards and micro-pumice fragments using scanning electron microscopy (sem) coupled with an energy-dispersive-spectrometry (eds). chemical analyses of glass shards and micro-pumice fragments were performed using an edax-dx micro-analyser mounted on a philips sem 515 at the dipartimento di scienze della terra, university of pisa employing a 20 kv acceleration voltage, 100 s live time counting, 21002400 shots per second, and zaf correction. the zaf correction procedure does not include natural or synthetic standards for reference, and requires the results to be normalized to a given value (which was chosen at 100%). in particular two standards with chemistry accurately obtained using xrf analyses are routinely analyzed in the pisa laboratory: a trachyte glass from campi flegrei (cr1) and an albite (marianelli & sbrana, 1998). to avoid alkali loss, especially na, a window spot usually with side ca 10 μm is used. owing to the different shape and size of glass shard a smaller size can be used and this can influence analytical data (hunt & hill, 2001). however, this is minimized by the selection of the bigger shards and having the possibility to analyses many different shards from the same sample. analytical precision is 0.5 % for abundances higher than 15 wt. %, 1 % for abundances around 5 wt. %, 5 % for abundances of 1 wt. %, and less than 20 % for abundances close to the detection limit (around 0.5 wt. %) (marianelli & sbrana, 1998). several trials for comparing the performance of pisa sem-eds with the wave dispersion spectroscopy (wds) have been extensively discussed by cioni et al. (1998), marianelli & sbrana (1998), vogel et al. (2010), sulpizio et al. (2010b) and caron et al. (2010), indicating comparable performances on major elements. as basis for chemical correlation the data set of santacroce et al. (2008), which is the collection of many years of analytical work on proximal deposits on somma-vesuvius, was used having the advantage to be produced in the pisa laboratory with the same analytical equipment. marchini g. et al. fig. 2 core lithology, magnetic susceptibility (k, 10-5 si units) and tephra position in ad91-17. 79 4. results and discussion 4.1 tephra correlation tephra 1 cm depth the topmost tephra layer does not contain any volcanic glass suitable for analyses. morphologically, volcanic fragments were observed as an aggregate of minerals (fig. 3a). therefore, we analysed only mineral phases found in the samples, with particular attention to pyroxene crystals. the pyroxene compositions in the wo-en-fe diagram is shown in fig. 4 (table 2). this compositional range is common to most of the pyroxenes from somma-vesuvius products. in particular, the geochemical data suggest a correlation to the field defined by the ad 1631 pyroxenes (santacroce, 1987; cioni et al., 1998; and unpublished data, fig. 4). for comparison in the figure 4 data from 1944 and 1906 eruptions from somma-vesuvius are shown along with the compositional field defined by ad 1631. tephra layers at 40-41 cm and 45-46 cm the sem observation for the two layers at 41 cm and 46 cm depth showed that glass phase was too altered (fig. 3b) and it was not possible to perform any analysis on volcanic glass with confidence. however, analyses allowed to identify the presence of sodalite. having no reliable glass compositions, a tentative correlation of this tephra layer, must be made making some consideration, such as the stratigraphic position of the layers and the aspect of the sediment seen with the optical microscope, albeit it is largely speculative. sodalite is frequent in the vesuvian products of the ad 472, avellino, and/or the ap products (santacroce et al., 2008; zanchetta et al., 2011). however, this felspatoid is also reported in some lavas of campi flegrei and different magmatic rock from ischia (melluso et al., 2012,2014), but not in pyroclastic deposits. observations using the optical microscope, showed altered pumice of a very dark colour in both layers. this would suggest to attribute this layer to the pollena ad 472 products rather than avellino ones. indeed, while the less evolved avellino deposits are also described as dark pumices, they are very glassy also in distal deposit (sulpizio et al., 2008, 2010a). on the contrary, the pollena ad 472 deposits contain very dark juvenile fragments with a crystal rich matrix also on distal reaches (sulpizio et al., 2010a; vogel et al., 2010). fig. 3 -tephra morphology by sem-eds. (a) layer 0-1 cm, (b) layer 40-41, (c) layer 170-171 cm and (d) layer 190/195 cm depth. tephrostratigraphy of marine core ad91-17 ... 80 on the other hand the age model of sangiorgi et al. (2003), indicates older ages suggesting the ap eruptions (andronico & cioni, 2002). therefore, at this stage we just tentatively propose a correlation with pollena ad 472 for the layer at 45-46 cm. due to their stratigraphic position, the second layer at 40-41 cm could be thus correlated with ad 512. however, the few data available make these correlations still speculative. tephra layer at 170 cm this layer is rich in volcanic glass shards and micropumices (fig. 3c) allowing a large number of analyses to be performed (table 1). in the tas diagram (total alkali silica) data plot in the rhyolite field (fig. 5a). specifically, comparing this layer composition with the data in literature (fig. 5c; caron et al., 2012) the correlation to e1/gabellotto-fiumebianco deposit is evident. e1 tephra layer is widespread in mediterranean (paterne et al., 1988; siani et al., 2004; sulpizio et al., 2014) and has been correlated with the activity of gabellottofiumebianco source on lipari island. the age of this tephra has been constrained by radiocarbon dating at 7770 ± 70 yr bp (8730-8400 cal yr bp) by siani et al. (2004) on a marine core and confirmed by subsequent studies (caron et al., 2012). tephra layers at 190-191 cm and 195-196 cm the layers found at 190-191 cm and 195-196 cm depth are similar and homogeneous in composition and thus were considered together. both have abundant vesicular micropumice fragments with thick septa (fig. 3d) on which several eds analyses were performed (table 1). on the tas diagram these analysis plot in the phonolitic field (fig. 5b), making it easy the correlation to the mercato eruption of somma-vesuvius table 1 major-elements composition of pyroxenes from layer at 1 cm. table 2 major-elements glass chemistry of tephras recognised in core ad91-17. marchini g. et al. 81 (santacroce et al., 2008; mele et al., 2011; fig. 6b), radiocarbon dated at 7770 ± 40 yr bp (8630-8430 cal yr bp; zanchetta et al., 2011). 4.2. summary and general implications based on the glass and mineral composition as well as on the stratigraphic order of the tephras in the ad91-17 core (fig. 2), we can propose the following correlations: i) 1 cm depth tephra, ad 1631 eruption of somma-vesuvius; ii) for the 41 cm and 45 cm depth tephra layers, no certain correlation can be proposed, but for the stratigraphic position and the presence of sodalite they could be related to the eruptions of ad 472 (pollena) and ad 512 of somma-vesuvius, respectively; iii) 171 cm depth tephra layer, e1/gabellottofiumebianco eruption of lipari island, dated at 87308400 cal yr bp (siani et al., 2004); iv) 191 cm and 195 cm depth tephra layers, mercato eruption of sommavesuvius dated at 8630-8430 cal yr bp (zanchetta et al., 2011). beside the correlation of the tephra layers to the parental eruptions, it is worth noting that e1 tephra layer is placed just below the interruption in-between sapropel s1 (fig. 2). this is consistent with the position of tephra e1 in md90-917 (siani et al., 2004) and md90-918 (caron et al., 2012). therefore, the present data confirms that e1 tephra layer could be regarded as a good marker for correlating tyrrhenian, ionian and adriatic sea achieves during the sapropel s1 interruption (zanchetta et al., 2011), which is correlated with the climatic deterioration recorded at ca. 8.2 ka (siani et al., 2001). the two layers sharing the composition of mercato pyroclasts support the suggestion of caron et al. (2012) fig. 4 -wo-en-fe ternary diagram of pyroxenes from layer at 1 cm. data for comparison of 1906, ad 1944 and ad 1631 are also shown. data from santacroce, 1987, santacroce et al., 1993, cioni et al., 1998 and marianelli et al., 1999. fig. 5 total alkalysio2 diagram (le bas et al., 1986) for the studied tephra layers (a); comparison with layers at 190-191 and 195-195 cm with mercato chemical data (caron, 2009; caron et al., 2012) (b); comparision with e1/gabellotto-fiumebianco tephra layers (caron et al., 2012). tephrostratigraphy of marine core ad91-17 ... 82 that in distal setting this eruption is represented by more than one layer. in core md90-918 they occur at the base of the second sapropel layer (s1b) just above e1 and within the basal part of sapropel (s1a). the lowermost layer occur just below the s1a (caron et al., 2012). in core ad91-17 one of the mercato layers is at base of the sapropel s1 and the other one just below the sapropel. both can correspond to two lower layers identified in caron et al. (2012). therefore, the core ad91-17 seems to confirm that at least two eruptive events with identical composition to the products from mercato eruption are widespread in the mediterranean archives. on the basis of the new tephrostratigraphic data, it is therefore questioned the previous correlation proposed by sangiorgi et al. (2003) of one of these layers to the agnano pomici principali eruption from campi flegrei. the agnano pomici principali tephra layer is a good marker of the younger dryas interval (lane et al., 2011), whereas mercato tephra layers are entirely within the holocene. figure 6 illustrates the difference in age model compared to sangiorgi et al. (2003). the age model proposed in this work contains the radiocarbon ages from sangiorgi et al. (2003) and the ages of tephra layers discussed in this work with the exception of tephras at 40 and 46 cm, for which a secure correlation cannot be supported. all the radiocarbon ages are calibrated using updated marine09 curve in calib 6 (reimer et al., 2009). differences can be appreciated for the top of the core and for the lower part of the records. the difference from the new age model and that of sangiorgi et al. (2003), at ca. 190 cm, where the age of mercato recently proposed by zanchetta et al. (2011) is imposed to the age model, produces an increase of sedimentation rate and a shorter duration of the lower part of the sapropel s1. in the sangiorgi’s age model the age of this point is directly controlled by a radiocarbon ages, which yielded an older age. we have, however, to note that reservoir effect could be different during different time (siani et al., 2001), and this can explain this difference. however, more data are necessary to clarify the succession and chronology of the event characterising the mercato eruption(s). these differences highlighted the importance of tephra layers in improving ages model when tephras are well identified and dated, but also the work needed to improve our knowledge on tephrochronology of the central mediterranean. 5. conclusions data collected in ad91-17 confirm some previous tephrostratigraphic studies in the area, and details the occurrence of some peculiar tephra layers like gabellotto-fiumebianco (e1) and mercato tephra layers. in particular, data of the present study are of particular relevance for the high-resolution mediterranean tephrostratigraphy, because they confirm that there are multiple eruptive events compositionally indistinguishable from mercato that occurred in different periods. this makes the chronological use of this tephra marker(s) more complex than suggested in the past and highlights the need to clarify the timing and stratigraphic succession of this eruption on proximal to distal reaches. the tephra layer e1 is confirmed as an important marker for sapropel interruption, as suggested by zanchetta et al. (2011) and caron et al. (2012). in the future, a new detailed stratigraphy for the sapropel s1 interval can emerge and chemical and stratigraphic data will permit a very powerful correlation of the different parts of the sapropel s1 in different sector of adriatic and ionian seas. finally, this tephrostratigraphic study has questioned some of the previous proposed correlation for tephra from the core ad91-17, that have appreciable impact on the core age-model. more in general, this work indicates and confirms that tephrostratigraphy is a fundamental tool for reefing the chronology of marine cores but that no correlation can be attempted without robust chemical data. acknowledgements we thank c. morigi for the friendly discussion on the core stratigraphy and sapropel stratigraphy. we thank the reviewers giaccio b. and insinga d. who made very useful comments for improving the final version of the manuscript. this is publication n. 1855 of ismar-cnr fig. 6 age model from sangiorgi et al., 2003 and this work. all the radiocarbon data were calibrated according to reimer et al., 2009. marchini g. et al. 83 references andronico d., cioni r. (2002) contrasting styles of andronico d., cioni r. (2002) contrasting styles of mount vesuvius activity in the period between the avellino and pompeii plinian eruptions, and some implications for assessment of future hazards. bulletin of volcanology, 64, 372-391. barberi f., macedonio g., pareschi m.t., santacroce r. (1991) mapping the tephra fallout risk: an example from vesuvius, italy. nature, 344, 6262, 142144. capotondi l., morigi c. (1996) the last deglaciation in the south adriatic sea: biostratigraphy and paleoceanography. il quaternario, italian journal of quaternary science, 9, 679-686. capotondi l., borsetti a.m., morigi c. (1999) foraminiferal ecozones, a high resolution proxy for the late quaternary biochronology in the central mediterranean sea. marine geology, 153, 253-274. caron b., siani g., sulpizio r., zanchetta g., paterne m., santacroce r., tema e., zanella e. (2012) late pleistocene to holocene tephrostratigraphic record from the northern ionian sea. marine geology, 311-314, 41-51. caron b., sulpizio r., zanchetta g., siani g., santacroce r. (2010) the late holocene to pleistocene tephrostratigraphic record of lake ohrid (albania). comptes rendus geoscience, 342 453-466. cioni r., marianelli p., santacroce r. (1998) thermal and compositional evolution of the shallow magma chambers of vesuvius: evidence from pyroxene phenocrysts and melt inclusions. journal of geophysical research, 18, 277-294. di vito m.a., isaia r., orsi g., southon j., de vita s., d'antonio m., pappalardo l., piochi m., (1999) volcanism and deformation since 12,000 years at the campi flegrei. journal of volcanology and geothermal research, 91, 221246. giaccio b., nomade n., wulf s., isaia r., sottili g., cavuoto g., galli p., messina p., sposato a., sulpizio r., zanchetta g. (2012) the late mis 5 mediterranean tephra markers: a reappraisal from peninsular italy terrestrial records. quaternary science reviews, 56, 31-45. giunta s., negri a., morigi c., capotondi l., combourieu-nebout n., emeis k.c., sangiorgi f., vigliotti l. (2003) coccolithophorid ecostratigraphy and multi-proxy paleoceanographic reconstruction in the southern adriatic sea during the last deglacial time (core ad91-17). paleogeography, paleoclimatology, paleoecology, 190, 39-59. hunt j.b., hill p.g. (2001) tephrological implication of beam size-sample-size effects in electron microprobe analysis of glass shards. journal of quaternary science, 16, 105-117. insinga d.d., tamburrino s., lirer f., vezzoli l., barra m., de lange g.l., tiepolo m., vallefuoco m., mazzola s., sprovieri m. (2014) tephrocronology of the astronomically-tuned kc01b deep-sea core, ionian sea insights into the explosive activity of the central mediterranean during the last 200 ka. quaternary science reviews, 85, 63-84. keller j, ryan w.b.f., ninkovich d., altherr r. (1978) explosive volcanic activity in the mediterranean over the past 200,000 yr as recorded in deep-sea sediments. geological society america bulletin, 89, 591-604. jorissen f.j. (1999) benthic foraminiferal successions across late quaternary mediterranean sapropels. marine geology, 153, 91-101. lane c.s., andri m., cullen v.l., blockley s. p.e. (2011) the occurrence of distal icelandic and italian tephra in the lateglacial of lake bled,slovenia. quaternary science reviews, 30,1013-1018. le bas m.j., le maitre r.w., streckeisen a., zanettin b. (1986) a chemical classification of volcanic rocks based on the total alkali-silica diagram. journal of petrology, 27, 745-750. lowe d.j. (2011) tephrochronology and its application: a review. quaternary geochronology, 6, 107153. marianelli p., metrich n., sbrana a. (1999) shallow and deep reservoirs involved in magma supply of the 1944 eruption of vesuvius. bulletin of volcanology, 61, 48-63. marianelli p., sbrana a., (1998) risultati sulle misure di standard di minerali e di vetri naturali in microanalisi a dispersione di energia. atti società toscana di scienze naturali memorie, serie a, 105, 5763. mele d., sulpizio r., dellino p., la volpe l. (2011) stratigraphy and eruptive dynamics of a longlasting plinian eruption of somma-vesuvius: the pomici di mercato (8900 years bp). bulletin of volcanology, 73, 257-278. melluso l., dè gennaro r., fedele l., franciosi l., morra v. (2012) evidence of crustallization in residual, cl-f rich, agpaitic, trachyphonolitic magmas and primitive mg-rich basal-trachyphonolite interaction in the lava domes of the phlegrean field (italy). geological magazine, 149, 532-550. melluso l., morra v., guarino v., dè gennaro r., franciosi l., grifa c. (2014) the crystallization of shoshonitic to peralkaline trachyphonolitic magmas in a h2o-cl-f-rich environment at ischia (italy), with implications for the feeder system of the campania plain volcanoes. lithos, doi: 10.1016/ j.lithos.2014.10.002. narcisi b., vezzoli l. (1999) quaternary stratigraphy of distal tephra layers in the mediterranean an overview. global and planetary change, 31-50. paterne m., guichard f., duplessy j.c., siani g., sulpizio r., labeyrie j. (2008) a 90,000-200,000 yrs marine tephra record of italian volcanic activity in the central mediterranean sea. journal of volcanology and geothermal research, 177, 187196. paterne m, guichard f and labeyrie j (1988) explosive activity of the south italian volcanoes during the past 80,000 years as determined by marine tephrochronology. journal of volcanology and geothermal research, 34, 153-172. peccerillo a. (2005) plio-quaternary volcanism in italy. springer verlag, berlin heidelberg. 365 pp. tephrostratigraphy of marine core ad91-17 ... 84 reimer pj, baillie mgl, bard e et al. (2009) intcal09 and marine09 radiocarbon age calibration curves 0-50,000 years cal bp. radiocarbon, 51, 1111-1150. sangiorgi f., capotondi l., combourieu nebout n., vigliotti l., brinkhauis h., giunta s., f. lotter a., morigi c., negri a. and reichart g.j. (2003) holocene seasonal sea-surface temperature variations in the southern adriatic sea inferred from multiproxy approach. journal of quaternary science, 18-8, 723-732. santacroce r. (1987) somma-vesuvius. consiglio nazionale delle ricerche, quaderni de “la ricerca scientifica”, cnr-roma, 251 pp. santacroce r., bertagnini a., civetta l., landi p., sbrana a. (1999) eruptive dynamics and petrogenetic processes in a very shallow magma reservoir: the 1906 eruption of vesuvius. journal of petrology, 34, 383-425. santacroce r., cioni r., marianelli p., sbrana a., sulpizio r., zanchetta g., donahue d.j., joron j.l., (2008) age and whole rock-glass compositions of proximal pyroclastics from the major explosive eruptions of somma-vesuvius: a review as a tool for distal tephrostratigraphy. journal of volcanology and geothermal research, 177, 1-18. siani g., paterne m., miche e., sulpizio r., sbrana a., arnold m., haddad g., (2001) mediterranean sea surface radiocarbon reservoir age changes since the last glacial maximum. science, 294, 19171920. siani g., sulpizio r., paterne m., sbrana a. (2004) tephrostratigraphy study for the last 18,000 14c years in a deep-sea sediment sequence for the south adriatic. quaternary science review, 23, 2485-2500. sulpizio r., bonasia r., dellino p., di vito m.a., la volpe l., mele d., zanchetta g., sadori l. (2008) discriminating the long distance dispersal of fine ash from sustained columns or near ground ash clouds: the example of the pomici di avellino eruption (somma-vesuvius, italy). journal of volcanology and geothermal research, 177, 263276. sulpizio r., cioni, r., di vito m.a., mele d., bonasia r., dellino p. (2010a) the pomici di avellino eruption of somma-vesuvius (3.9 ka bp) part i: stratigraphy, compositional variability and eruptive dynamics. bulletin of volcanology, 72, 539-558. sulpizio r., zanchetta g., d’orazio m., vogel h., wagner b. (2010b) tephrostratigraphy and tephrochronology of lakes ohrid and prespa, balkans. biogeosciences, 7, 3273-3288. sulpizio r., zanchetta g., caron b., dellino p., mele d., giaccio g., insinga d., paterne m., siani g., costa g., macedonio g., santacroce r. (2014) volcanic ash hazard in the central mediterranean assessed from geological data. bulletin of volcanology, doi 10.1007/s00445-014-0866-y vigliotti l., asioli a., bergami c., capotondi l., piva a., (2011) magnetic properties of the youngest sapropel s1 in the ionian and adriatic sea: inference fort he timing and mechanism of sapropel formation. italian journal of geoscience, 130, 106118. vogel h., zanchetta g., sulpizio r., wagner b., nowaczyk n. (2010) a tephrostratigraphic record for the last glacial-interglacial cycle from lake ohrid, albania and macedonia. journal of quaternary science, 25(3), 320-338. zanchetta g., sulpizio r., roberts n., cioni r., eastwood w. j., siani g., caron b., paterne m. and santacroce r. (2011) -tephrostratigraphy, chronology and climatic events of the mediterranean basin during the holocene: an overview. the holocene, 21(1), 33-52. ms. received: september 10, 2014 final text received: november 13, 2014 marchini g. et al. microsoft word 00_indice_06lm.docx il quaternario it issn 039-3356 italian journal of quaternary sciences 24 (2), 2011 193-198 considerations on an integrated biochronological scale of italian quaternary continental mammals federico masini1 & benedetto sala2 1 dipartimento di geologia e geodesia, università di palermo, palermo 2 dipartimento di biologia ed evoluzione, università di ferrara, ferrara corresponding author: benedetto sala <benedetto.sala@unife.it> abstract: abstract: masini f. & sala b., considerations on an integrated biochronological scale of italian quaternary continental mammals. the paper of masini and sala (2007) regarding an integrated approach on the stratigraphic distribution patterns of large and small mammals in the late pliocene and pleistocene of the italian peninsula is analysed, showing the weak and strong points. new data are presented on the mammal biochronology of the late pleistocene riassunto: masini f. & sala b., considerazioni su una scala biocronologica integrata dei mammiferi continentali quaternari in italia. viene analizzato il lavoro di masini e sala (2007) sull’approccio integrato della distribuzione dei grandi e piccoli mammiferi dell’italia continentale del tardo pliocene e del pleistocene, tenendo conto della nuova definizione del quaternario, mettendo in risalto i punti di forza e quelli deboli della scala proposta. vengono inoltre aggiunti nuovi dati sulla biocronologia a mammiferi del pleistocene superiore. keiwords: biochronology, mammals, quaternary, italian peninsula. parole chiave: biocronologia,mammiferi, quaternario, italia continentale. despite the marginal geographical position of the italian peninsula in the eurasian continent, italian quaternary deposits have yielded a good succession of well diversified fossil mammal assemblages. the effect of the quaternary climatic changes on faunal associations was moderate due to the gentle effect of the sea. however, there are important differences between the ligurian tyrrhenian coast and the adriatic coast, which interrelate with the significant latitudinal extension and complex geomorphological setting of the peninsula (sala 2002; sala and marchetti 2006). this diverse geographical situation allowed some species to use specially protected areas as refuges during very cold climatic phases. mammalian biochronology has a certain tradition in italy thanks to the pioneering works of azzaroli (1977). villafranchian and galerian large mammal ages, mainly defined on the italian succession of large mammal faunas, are of common use in italy as well as in some other european countries. however, the so called holarctic biochronological scale based on small mammal faunas, mostly arvicolids, is most widespread for the plio pleistocene of europe and the former soviet union. this contribution is a revision of an updated version of the biochronology proposed by masini and sala (2007), sala and masini (2007), in which large and small mammals scales are correlated (the references of the sites here cited are referred to the former paper). the adopted large mammal biochronology is that pioneered by azzaroli (1977), and further developed mainly by italian students; the small mammal scale is that of fejfar and heinrich (1990). correlation presents some difficulties, as only few deposits of the early pleistocene and part of the middle pleistocene have valid documentation of mammals of both classes of size. the complexity of the correlations is also influenced by many taphonomic factors and by different approaches to the study of the two groups of mammals (e.g. sala 1983; palombo 2004; masini and abbazzi 2004). the adopted chronostratigraphical frame is that of gibbard et al (20052007) according to gibbard and head (2009) and gibbard et al (2009) definitions. recently, palombo (2009) focuses on the differences between biochronology and biostratigraphy, and bases her chronological framework on large mammals, reporting advantages and deficiencies. the use of large mammals data does not allow, for example, to recognize the age of valdemino faunal assemblage (lower layers), which is included, for the small mammals, in the lower toringian for the occurrence of arvicola mosbachensis and the lack of mimomys savini, while it is incorrectly referred to the slivia fu by palombo 2009. this author does not accept the saint vallier fu because not well documented in italy and encloses the faunal remains of this unit in costa s. giacomo fu. the base of the quaternary period corresponds to the beginning of the middle villafranchian (montopoli faunal unit = fu) large mammal age, and roughly to the end of the early villanyian small mammal age. the deposit of montopoli (pisa), which occurs at the gaussmatuyama transition (lindsay et al. 1980), however, is not preceded by adequate documentation of the faunal transition from early villafranchian and only yielded large mammal remains. other sites of this fu (bocchimasini f. & sala b. 194 gnano, rieti; vinci, pisa; montecarlo, firenze; anagni, frosinone) contain scant assemblages. the second part of the middle villafranchian is documented by sporadic finds, possibly representing the st. vallier fu (e.g. castel viscardo, orvieto) and by the fauna of the costa san giacomo fu. the rich micro-teriofaunas of rivoli veronese (verona) and montagnola senese (siena) well document the occurrence of the late villanyian in italy and correlate with the latest part of the middle villafranchian, even though the lack of significant large mammal finds in these localities does not allow a direct correlation. the transition to the olivola fu (early late villafranchian) is quite gradual, as it is that to the next tasso fu. monte la mesa (verona) yielded a very rich small mammal fauna, referable to the early part of the early biharian, and likely correlated to the tasso fu. the scant remains of large mammals at monte la mesa, however, again highlight the correlation problems mentioned above. the magnetostratigraphic correlations of the faunas of this part of villafranchian are based almost exclusively on findings in the upper valdarno basin, where the sediments containing fauna of tasso (arezzo) refers to the top of the sub-magnetochrone olduvai and thus are placed at the base of the second part of early pleistocene (calabrian). the fu of farneta and pirro include early biharian micro-fauna (pietrafitta, cava pirro dell'erba, soave cava sud) found together with rich late villafranchian large mammal assemblages, thus giving a direct correlation between the two biochronological scales. a calibration for these two faunal units is lacking, but the evolutionary stages of some taxa (allophaiomys) allow to propose a dating around 1.5 and 1.3 ma respectively. the colle curti (macerata), castagnone (alessandria) and monte peglia (perugia) localities are attributed to the sub-magnetochron jaramillo. they contain large mammals of the beginning of the galerian age (colle curti fu) and small mammals of late early biharian. the following early galerian slivia fu yielded typical late biharian microfaunas, where microtus (allophaiomys) is absent and mimomys savini is associated to more advanced species of microtus. the small mammal fauna of rifreddo (potenza) belongs to the same fu and is correlated to the lower part of brunhes chron. documentation becomes richer during the middle galerian. the most important sites are isernia la pineta (isernia), valdemino cave (savona), visogliano (trieste), deeper layers, and venosa-notarchirico (taranto). the middle galerian coincides with the beginning of toringian, characterised by the substitution of mimomys savini by arvicola mosbachensis. this transition is linked to climate change, with the appearance of more arid environments, at least seasonally, determining greater differences between “cold” and “warm” faunas within the glacial-interglacial cycles. palaeomagnetic and radiometric dating are available at isernia and notarchirico. the climatic and faunal changes lead to the late galerian fauna, represented by the fontana ranuccio fu. the small mammal faunas, e.g. boscochiesanuova (verona), loara and commenda (vicenza) (bartolomei 1969, 1980) belong to the early toringian, while large mammal faunas are difficult to be placed chronologically, since they poorly differ from the previous ones. the increase in climatic differences between warm and cold periods, the beginning of a marked regionalism, the similarity of the faunas, especially during warm periods, and the lack of “absolute” dating introduce some uncertainties when assigning the chronology of the deposits. the spread of faunas with cold affinities (e.g. the occurrence of the modern wolf, the boreal lynx and the ibex) indicates the beginning of the aurelian mammal age (or post-galerian). we are approaching to the end of the middle pleistocene, and the increased documentation, the regional differences, the intensity of climatic oscillations require finer chronological detail. from this moment on, the utility of the faunal unit falls short, in favour of marine isotope stages (mis) which scan the chronology of the major climatic fluctuations very well. sites with transitional faunas and those referred to the beginning of the aurelian yielded mammals of warm environments. most important ones are in latium (riano, castel di guido, malagrotta, polledrara of cecanibbio), where the arrival of a bubalus of asian origin is reported, thus indicating one or more “hot" climatic oscillations. bubalus arrives twice in germany, during the steinheim interglacial (holstenian), and later during the eemian (koenigswald 1986). the faunal association from steinheim includes mammals such as bubalus murrensis, palaeoloxodon antiquus, bos primigenius, megaloceros giganteus, stephanorhinus kirchbergensis (czarnetzki 1983) that are also found in latium faunal assemblages; likely the latter faunas should be referred to mis 7. palombo et al. (2004), however, according to their interpretation of the sequence stratigraphy of the roman basin, suggest a correlation with mis 9 for torre in pietra 1, monte delle gioie, sedia del diavolo, polledrara of cecanibbio and castel di guido, and with mis 7 for vitinia, quartaccio and torre in pietra 2. the cold faunas are affected minor uncertainty. the sequences of poggio cave and of grotta grande sector c. of scario (salerno), the outer levels of paglicci cave (foggia) and san bernardino cave (vicenza) and the r and s layers of broion cave (vicenza) contain faunas dominated by first cold mountain goats arriving in the italian peninsula, capra ibex, and are referred to mis 6. the transition between early and late toringian is somewhat blurred in the italian peninsula due to the possible co-occurrence of two species of arvicola. recently, petronio et al. (2007) proposed two new faunal units for the late aurelian but, as reported above, especially for the regional differences during this period, we are unfavourable to the use of faunal units for assemblages younger than mis 7 and we do not accept this proposal. moreover, the use in biochronology of the occurrence of not easy recognizable subspecies, such as dama dama dama, and of mammals which are very rare in italy, such as coelodonta antiquitatis, to define a fu is not applicable. in masini and sala (2007) the late pleistocene was scantily reported and commented, so we provide here with new data. the last interglacial (eemian, mis 5e), which marks the beginning of the late pleistocene, is documented by the sediments of some coastal caves containing remains of large vertebrates and recently yielded the remains of small mammals, e.g. the deepest levels of cavallo cave (lecce). there are, however, some temperate faunas ascribed to a generic mis 5, e.g. san sidero 3 (lecce) and grotta grande of scario s.a. (salerno).   considerations on an integrated biochronological scale … 195 tab. 1: integrated stratigraphic scheme for the quaternary large and small mammalian record of the italian peninsula. schema stratigrafico integrato del quaternario per il record dei grandi e piccoli mammiferi della penisola italiana masini f. & sala b. 196 tab. 2: integrated stratigraphic scheme for the mis 6-1 large and small mammalian record of the italian peninsula. schema stratigrafico integrato del mis 6-1 per il record dei grandi e piccoli mammiferi della penisola italiana the iiird level of caverna delle fate (savona) is assigned by psathi (2003) to mis 5, but quilès (2003), using the p4 morphometric index of ursus spelaeus (rabeder 1999), infer an age of 90 ka, roughly corresponding to mis 5c or 5a. the faunal assemblage from madonna dell’arma and from the lower levels of grotta del principe (imperia), considered coeval, are referred to mis 5c or 5a (valensi 2009). in two papers on large (rubinato 2009) and small mammals (berto 2009) from caverna degli orsi (trieste) the stratigraphic units 14.1 of the sector a and 125-122 of the sector b are ascribed to the temperate oscillation of mis 5a. during the mis 5, in italy, and probably also in all the europe, palaeoloxodon antiquus and hippopotamus are still quoted, but not during mis 4, probably due to the first climatic rigours of the last glacial (wurmian). dama dama, abundant in mis 5e, becomes rarer in mis 5c-a but it is present also e.g. at caverna degli orsi, in the north-east, where the environment was less temperate then in other parts of the peninsula, in plane or at the foot of the mountains. the levels iiib of caverna delle fate, the upper levels of grotta del principe, the levels iv÷i of arma delle manie (savona) are assigned to mis 4 (valensi 2009). some other sequences of caves and shelters with mousterian industries and rich of faunas are ascribed to this stage, e.g. upper layers of ghiacciaia cave (verona) (sala 1990). many other sites bear long sequences with mousterian industries but dating are scarce. after 50 ka, the 14c radiometric dating are of assistance for the chronology and recently also tl dating and u/th-esr combined dating are used above all in prehistoric sites. an example is supplied by peresani et al. (2008), in which uluzzian levels of fumane cave and others sites in the eastern italian pre-alps, slovenia and croatia are quoted with those methodologies to mis 3 (layers i of broion cave, rio secco cave, layers b through e1 and ei/e2 of munjina pećina, level g3 of vidinja cave and others). other prehistoric localities are attributed to mis 3, e.g.mezzena shelter (verona) (giunti et al. 2008). later, with the appearance of the upper palaeolithic industries and their undoubted chronological value, the dated layers are very numerous. if the referral to isotopic stage is adopted, the sub-stage should be specified, because the minor climatic oscillations occurring within a stage are reflected in changes in faunal associations. the geographic location of the site must also be considered with the highest regard, because of the occurrence of regional faunal differences and since even small changes in altitude or topography of the area determined important differences in the assemblages of both micro-and macro-mammals. the sequence of the castelcivita cave records the mousterian late paleolithic transion; the rich faunal assemblages (masini & abbazzi, 1997) are well representative of the mammalian populations of the middle to late part of mis 3 (substages mis 3,12 to mis 3,01, sensu pisias et al. 1984; paterne et al. 1986) at the tyrrhenian side of the peninsula (napoleone et al. 1997). in the mis 3 some mammals are present for the last time, e.g. dama dama in the aurignacian levels of the cala cave (benini et al. 1997), mammuthus primigenius and megaloceros giganteus at settepolesini di bondeno (ferrara) (gallini and sala 2001). mis 2 is well documented in italian peninsula and some papers furnish information on faunal assemblages considerations on an integrated biochronological scale … 197 of the last glacial maximum (sala 2004 and references in it) or of the late glacial (sala 2007 and references in it) of numerous sites of the whole italian peninsula. among the carnivores, the occurrence of crocuta spelaea is noted for the last time in the ancient epigravettian layers of paglicci cave (boscato and palma di cesnola 2000). the mammal faunas of the ancient holocene also are well known and come from mesolithic and neolithic sites. in the holocene the reduction of biodiversity is only partially compensated by the arrive of martes foina, micromys minutus, mus domesticus and later of rattus rattus, rattus norvegicus; very recently apodemus agrarius, erinaceus concolor and canis aureus begin to spread in the north-eastern of italy. references azzaroli, a., 1977. the villafranchian stage in italy and the plio-pleistocene boundary. giornale di geologia, 41, pp. 61-79. bartolomei g. 1969 primi contributi alla conoscenza dei dolomys pleistocenici del veneto e del carso. mem. mus. civ.st. nat. verona, 17, pp. 79-139, 32 figg. bartolomei g., 1980 i micro mammiferi del plio-pleistocene. in: aa.vv. “i vertebrati fossili italiani, catalogo della mostra”. 1980, pp. 249-258, verona. benini a., boscato p., gambassini p.1997 grotta della cala (salerno): industrie litiche e faune uluzziane ed aurignaziane. rivista di scienze preistoriche, 48, pp. 37-95. berto c. 2009 la caverna degli orsi a san dorligo della valle dolina (trieste). una serquenza würmiana a micromammiferi. tesi di laurea specialistica in scienze preistoriche, univ. di ferrara. boscato p., palma di cesnola a. 2000 nuovi ritrovamenti di epigravettiano antico "iniziale" a grotta paglicci (rignano garganico, foggia). società preistoria protostoria friuli-venezia giulia, trieste, quaderno, 8, pp. 45-61. czarnetzki a.,1983. zur entwicklungdes menschen in südwestdeutschland. in: müller-beck (ed): “urgeschichte in baden württemberg”, pp. 217-240, stuttgart: theiss. fejfar o., heinrich w.d, 1990, muroid rodent biochronology of the neogene and quaternary of europe. in: e.h.lindsay, v. fahlbusch and p.mein (eds.) “european neogene mammal chronology”, pp. 91-116, plenum press, new york – london. gallini v., sala b. 2001 settepolesini di bondeno (ferrara eastern po valley): the first example of mammoth steppe in italy. in: cavarretta g., gioia p., mussi m., palombo m.r. (eds.) “the world of elephants”. proceedings of the ist internat. congress, rome (16-20 october 2001), pp. 272-275. gibbard, p.l., head, m.j., 2009. iugs ratification on the quaternary sistem/period and the pleistocene series/epoch with a base at 2.58ma. quaternaire, 20(4), pp.411-412. gibbard, p. l., head, m. j., walker, m. j. c. and the subcommission on quaternary stratigraphy 2009 formal ratification of the quaternary system/period and the pleistocene series/epoch with a base at 2.58 ma. journal of quaternary science, (published online in wiley interscience (www.inter science.wiley.com) doi: 10.1002/jqs.1338 gibbard p.l., boreham s., cohen, k.m., moscariello a., 2005/2007 global chronostratigraphgical correlation table for the last 2.7 million years, boreas, 34(1) unpaginated, modified/updated 2007. giunti p., caramelli d., condemi s., longo l. 2008 il sito musteriano i riparo mezzena presso avesa (veona, italia). aggiornamenti metodologici e nuovi dati paleoantropologici, paleogenetici e paleocomportamentali. bollettino del museo civico di storia naturale di verona, 32, pp. 39-53. koenigswald w. 1986 beziehungen des pleistozänen wasserbüffels (bubalus murrensis) aus europa zu den asiatischen wasserbüffel. sonderdruck aus z. f. säugetierkunde, 51, pp. 312-323, hamburg. lindsay, e.h., opdyke, n.o., johnson, n.m., 1980. pliocene dispersal of the horse equus and late cenozoic mammalian dispersal events. nature 287, pp.135-138. masini f., abbazzi l. 1997 l’associazione di mammiferi della grotta di castelcivita . in gambassini p. (a cura di) il paleolitico della grotta di castelcivita, cultura e ambiente. materiae, 5, pp. 33-57, ed. electa, napoli. masini f., abbazzi l. 2004 a preliminary quantitative taxonomic evaluation of the pliocene end pleistocene small mammal record in the italian peninsula. courier forschungs-institut senckenberg, 256, pp. 201-213, frankfurt am main. masini f., sala b. 2007 stratigraphic distribution patterns of large and small mammals in the late pliocene and pleistocene of the italian peninsula: an integrated approach. quaternary international, 160/1, pp. 43-56. napoleone g., fumanal m.d., masini f., abbazzi l. cassoli p.f., tagliacozzo a., castelletti l., maspero a. & p.gambassini 1997 sintesi delle conclusioni. in.: gambassini p. (a cura di), il paleolitico della grotta di castelcivita, cultura e ambiente. materiae, 5, pp. 147-151, ed. electa, napoli. palombo m.r., 2004 biochronology of the plio-pleistocene mammalian faunas of italian peninsula: knowledge, problems and perspectives. il quaternario 17 (2/2), pp. 565-568. palombo m.r., 2009 biochronology of terrestrial mammals and quaternary subdivisions: a case stydy of large mammals from the italian peninsula. il quaternario 22(2), pp.291-306. palombo m.r., milli s., rosa c., 2004 remarks on the late middle pleistocene biochronology on the mammalian faunal complexes of the campagna romana. geologica romana, 37(2003), pp. 135-143. paterne m., guichard f., labeyrie j., gillot p.y., fuplessy j.c., 1986 tyrrhenian sea tephrochronologyof the oxygen isotopic record for the past 60.000 years. marine geology 72, pp. 259-285. peresani m., cremaschi m., ferraro f., falgueres ch., bahain j.-j., gruppioni g., sibilia e., quarta g., calcagnile l., dolo j.-m. 2008 age of the final middle palaeolothic and uluzzian levels at fumane cave, northern italy, using 14c, esr, 234u/ masini f. & sala b. 198 230th and thermoluminescence methods. journal of archaeological sciences 35, pp. 2986-2996. petronio c., di canzio e., salari l. 2007 the late pleistocene and holocene mammals in italy : new biochronological and paleoenvironmental data. palaeontographica abt. a, 279 (4-6), pp.147-157. pisias n.g., martinson d.g., moore t.c. jr., shackletin n.j., pre3ll w., hays j.d. & boden g., 1984 high resolution stratigraphy correlation iof bentic oxigen isotopic record, spanning the last 300.000 years. marine geology, 56, pp. 110-136. psathi e. 2003 les sites moustériens de la caverna delle fate et de l’arma delle manie (ligurie, italie) etude palèontologique archéozoologiquedes faunes de grands mammifères. thèse de doctorat, muséum national d’histoire naturelle, paris 623 pp. quiles j. 2003 les ursidae du pléistocène moyen et supérieur en midi méditerranéen: apports paléontontologiques, biochronologiques et archéozoologiques. thèse de doctorat, musèum national d’histoire naturelle, paris tome i, 664 pp, tome ii, 643 pp. rabeder g. 1999 die evolution des höhlenbärengebisses. verlag der österreichischen akademiae der wissenschaften, wien, 102 pp. rubinato g. 2009 la caverna degli orsi di san dorligo della valle dolina. la macrofauna würmina dell’area b. tesi di laurea triennale in tecnologie per i beni culturali, università di ferrara. sala b. 1983 variations climatiques et sequences chronologiques sur la base des variations des associations fauniques a grands mammifères. rivista sc. preistoriche, 38(1-2), pp. 161-180, firenze. sala b. 1990 loess fauna in deposits of shelters and caves in the veneto region and examples in other region of italy. in: m. cremaschi editor: “the loess in northern and central italy”, quaderni di geodinamica alpina e quaternaria, 1, pp. 139-149, milano. sala b. 2002 le faune quaternarie. in: r. argano, c. chemini, s. la posta, a. minelli, s. ruffo (eds.) “la fauna in italia” . touring club italiano, pp. 382388, milano. sala b. 2004 large mammals of the lgm. in: f. antonioli and g:b: vai (editors) “climex maps italy explanatory notes”. 32nd internat. geological congress, florence – italy, pp. 47-48, bologna. sala b. 2007 mammalofaune tardoglaciali dell’italia continentale. in: martini f. (ed.) “l’italia tra 15.000 e 10.000 anni fa cosmopolitismo e regionalità nel tardoglaciale”. millenni, studi di archeologia preistorica 5, pp. 21-38, museo fiorentino di preistoria “paolo graziosi”, firenze. sala b., marchetti m. 2006 the po valley floodplain (northern italy): a transitional area between two zoogeographical areas during the late neogene and quaternary. cour. forsch.-inst. senckenberg, 256, pp. 321-328, frankfurt a.m. sala b, masini f. 2007 the late pliocene and pleistocene small mammal chronology in the italian peninsula. quaternary international, 160/1, pp. 4-16. valensi p. 2009 évolution des peuplements de grands mammifères en europe méditerranéenne occidentale durant le pléistocène moyen et superieur. un exemple régional: les alpes du sud françaises et italiennes. quaternaire, 20 (4), pp. 551-567. ms. ricevuto il 13 luglio 2010 testo definitivo ricevuto il 19 dicembre 2010 ms. received: july 13, 2010 final text received: december 31, 2010 review of ursus material from fontana ranuccio (middle pleistocene, central italy): new insights on the first occurrence of the brown bear in italy. jacopo conti1,2, luca bellucci3,4, dawid a. iurino2, flavia strani 2,4 , raffaele sardella 2,4 1 polo museale, sapienza università di roma, italy. 2 dipartimento di scienze della terra, paleofactory, sapienza università di roma, italy. 3 museo di geologia e paleontologia, sistema museale di ateneo, università degli studi di firenze, italy. 4 istituto italiano di paleontologia umana, roma, italy. corresponding author: j. conti <jacopo.conti@uniroma1.it> abstract: the middle pleistocene archaeo-palaeontological site of fontana ranuccio (anagni, central italy) yielded a rich faunal assemblage consisting of more than 20,000 fossil remains, including four human teeth and multiple bone and lithic tools. the ursus specimens from fontana ranuccio were historically ascribed to ursus deningeri and ursus arctos although a formal study has never been carried out. in this work, we have described for the first time all the ursus material from fontana ranuccio reassessing the taxonomical attributions and discuss the first occurrence of the brown bear in the italian peninsula. biometrical and morphological analyses confirm the presence of ursus deningeri but, due the scarcity of diagnostic features and/or their preservation, some isolated specimens have been ascribed to ursus sp. the results of this work allow to reconsider the earliest occurrence of u. arctos, attested in the italian peninsula to the late middle pleistocene site of bucine. keywords: ursus arctos, ursus deningeri, galerian, biochronology, systematics, evolution, carnivores. available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 34 (1), 2021, 55-68 1. introduction in the middle pleistocene locality of fontana ranuccio (0.4 ma; pereira et al., 2018), ursus fossils are represented by some isolated teeth and a third phalanx, found during the 1980s excavation campaigns led by researchers of the istituto italiano di paleontologia umana (hereinafter isipu). these remains were firstly assigned to ursus deningeri by biddittu et al. (1979) and cassoli & segre naldini (1993) which described only three specimens without providing a detailed comparison. few years later, azzaroli (1983) reported the presence of the brown bear ursus arctos in the “ranuccio local fauna” without providing any description of the fossil remains, thus opening the issue on the possible co-occurrence of two bear species in the fontana ranuccio site. successively, palombo et al. (2002 and references therein) reported in their faunal list only the presence of u. deningeri at fontana ranuccio, but without performing any direct study of the fossil material. in later publications, some authors reported the first occurrence (fo) of u. arctos at fontana ranuccio without supporting this statement with any comparison or analysis (capasso barbato et al., 1990; di stefano et al., 1994; sardella et al., 2006; petronio et al., 2011). finally, in a recent publication, petronio et al. (2019) considered the bear remains from fontana ranuccio as u. deningeri, moreover indicating for this site the last occurrence (lo) of the species. as in the previous works, the attribution was probably made on the basis of literature data, since there is a lack of direct descriptions and analyses of the materials. as a consequence of these ambiguous attributions, the taxonomy of ursus materials from fontana ranuccio has been doubtful. therefore, on the basis of the above-mentioned literature as well as from a biochronological point of view, the fo of the brown bear or the lo of the deninger bear in italy, or even both, could potentially be documented at fontana ranuccio. during the pleistocene several fossil bear species are recorded in the italian peninsula, such as the auvergne bear (ursus minimus, devèze de chabrol & bouillet, 1827), the etruscan bear (ursus etruscus, cuvier, 1823), the deninger bear (ursus deningeri, von reichenau, 1904), the cave bear (ursus spelaeus, rosenmüller, 1794) and the brown bear (ursus arctos, linnaeus, 1758) (conti, 1954; conti, 2019; borselli et al., 1980; bon et al., 1991; mazza & rustioni, 1994; palombo et al., 2002; petronio et al., 2007, 2020; petrucci & sardella, 2009). the first occurrence of u. deningeri in the italian peninsula is recorded in the late early pleistocene sites https://doi.org/10.26382/amq.2021.14 56 conti j. et al. fig. 1 geographical location of the middle pleistocene site of fontana ranuccio (modified by strani et al., 2018a). of slivia (ambrosetti et al., 1979; palombo et al., 2002 and reference therein; petronio et al., 2011, 2019). other localities of the early and middle pleistocene bearing u. deningeri remains are bristie i° (trentino alto adige; lugli & sala, 2000), ponte molle (lazio; petronio et al., 2011; mecozzi et al., 2021), selva vecchia (veneto; bon et al., 1991), isernia la pineta (molise; peretto & sala 2019), visogliano (friuli venezia giulia; palombo et al., 2002 and reference therein) and venosa (palombo et al., 2002 and reference therein). the oldest documented and figured specimen attributed to ursus arctos in the italian peninsula comes from the late middle pleistocene site of bucine (upper valdarno, tuscany) (masini et al., 1991; ferretti, 1997; gliozzi et al., 1997; palombo et al., 2002). the material consists in a fragmented cranium with the presence of the upper fourth premolar and the first and second upper molars, now stored at the “museo di geologia e paleontologia” at the università di firenze. the brown bear is also reported in sicily from two late middle pleistocene/late pleistocene localities, acquedolci and contrada camillà, both referred to the “elephas mnaidriensis faunal complex” (bonfiglio et al., 2001; pavia, 2001; marra, 2003). the material is abundant but fragmented, composed by three fragmentary hemimandibles, isolated teeth and fragmentary postcranial bones. other fragmented bone elements (one indetermined tooth and a phalanx) come from the layer 18 ripardo del poggio (salerno), dated approximately to mis 6 (boscato et al., 2009). in this study, we present the first detailed description and comparative analysis of the bear specimens from fontana ranuccio in order to: (1) define their taxonomic status; (2) verify the possible co-occurrence of u. arctos and u. deningeri at the site; (3) define the biochronological aspects as the possible fo of u. arctos or the lo of u. deningeri in the italian peninsula. 2. geographical and stratigraphical background the archaeo-palaeontological site of fontana ranuccio (fig. 1) is located in the anagni basin (biddittu et al., 1979; cassoli & segre naldini, 1993; florindo et al., 2021 and references therein), about 90 km southeast of rome, and it was discovered in 1976 during quarry activities for the exploitation of “pozzolana” (volcanic ash). since then, researchers of the isipu have carried out different field activities, in particular under the direction of a. segre (1978-2002), f. parenti (2004-2018) and s. grimaldi (2019 present). the fossiliferous layer has been recently dated to 0.4 ma (pereira et al., 2018). the vertebrate collection includes more than 20,000 specimens that are now stored in the isipu depository (anagni, frosinone). the large mammal assemblage have been attributed to 15 taxa (biddittu et al., 1979; cassoli & segre naldini, 1993; strani et al., 2018a; strani et al., 2018b; strani et al., 2019): palaeoloxodon antiquus, stephanorhinus sp., equus cf. mosbachensis, hippopotamus amphibius, dama clactoniana, cervus elaphus eostephanoceros, praemegaceros sp., bos primigenius, sus scrofa ferus, panthera sp., crocuta crocuta, canis mosbachensis, cf. vulpes sp., macaca sylvanus, ursus arctos, ursus deningeri and ursus sp. small mammal remains are scanty and have been recently ascribed by bona & strani (2021) to microtus (terricola) sp., talpa sp., elyomys sp., lepus sp., erinaceus sp., rodentia indet., cf. glis sp. finally, homo remains have been reviewed by rubini et al. (2014) and are associated to several (more than 800) lithic and bone tools (segre, 1984). since the pioneering work of azzaroli (1983) this faunal assemblage is a reference for the italian biochronological framework (gliozzi et al., 1997; petronio et al., 2011; petronio et al., 2019 and references therein). finally, grimaldi et al. (2020) carried out a techno-functional study of the entire lithic assemblage identifying five groups of retouched tools i.e., cutting tools, pointed tools, scrapers, notches and denticulates. 3. materials and methods ursus material from fontana ranuccio consists of 12 isolated remains (fig. 2) now stored at the isipu laboratory in anagni (frosinone). this fossil material was mainly found in the 1980s field activities, in particular in the 1982, 1984, 1985 and 1989 years. morphological analysis, descriptions and comparisons have been provided taking into account the from different researchers (ballesio, 1983; torres, 1988; capasso barbato et al., 1990; argant, 1991; mazza & rustioni, 1994; auguste, 1995; rabeder, 1999; quiles, 2003; meloro, 2007; wagner & sabol, 2007; wagner & čermák, 2012). morphological data have been compared with specimens of u. etruscus, u. deningeri, u. spelaeus and u. arctos 57 review of ursus material from fontana ranuccio (middle pleistocene, central italy) tab. 1 list of selected specimens used for morphological comparison. asterisks indicate the material directly studied by the authors. from selected european pleistocene and holocene localities (tab. 1). the ontogenetic stage was inferred according the scheme proposed by stiner (1998). the measurements of mesiodistal length and buccolingual width have been taken with digital caliper to the nearest 0.1 mm on each fossil specimen (tab. 2), with the exception of the teeth fr 85-1 s1, fr84-1 and the third phalanx (fr 84 inv 56576) due fragmentary preservation. dentognathic morphology and measurements follow the terminology proposed by rabeder (1999) and torres (1988). despite the high biometric variability of the teeth in the early and middle pleistocene bears, we performed standard bivariate plots of width vs. length of m1, p4, m2 and m3 in order to compare our samples with specimens from this time span in order to test possible biometrical patterns among the fontana ranuccio specimens and other pleistocene ursid taxa (torres, 1984; capasso barbato et al., 1990; marra, 2003; rabeder et al., 2010; wagner et al., 2017 and personal measurements; fig. 3). 4. systematic palaeontology class mammalia linnaeus, 1758 order carnivora bowdich, 1821 family ursidae fisher [de waldheim], 1817 genus ursus linnaeus, 1758 ursus sp. referred material: i2 right (fr sd-2), i3 right (fr 85-2 p3), i3 left (fr 82-2 res), c right (fr 85-1 s1), p4 right (fr 89-1), m1 left (fr 96-33), m2 left (fr 84-1), ph -3 (fr 84 inv 56576). incisors and fragmented material: the incisors, except fr sd-2, are well preserved and show the typical ursus morphology with a developed central cusp and the presence of two outlined lateral lobes; the distal one is less developed than the mesial one (fig. 2 f-g-h). the lower canine (fr 85-1 s1), the second lower molar (fr 84-1) and the first lower molar (fr 96-33) are fragmented; therefore, it is not possible to acquire any linear measurement or identify any distinctive character to define a specific attribution (fig. 2 i-l-m). however, it is possible to ascribe the specimen fr 96-33 to a prime adult individual (class vii). the third phalanx (fr 84 inv 56576, fig. 2 n) shows a rather elongated morphology, although it is particularly worn. the proximal portion, which is articulated with the trochlea of the second phalanx, is semicircular and the dorsal and plantar swelling that characterize this anatomical portion of the bone element are poorly developed. the ungual portion is thin with a gentle dorsal curvature until the most distal portion, where it sharply curves. due to high wear and the lack of any discriminant characters, we ascribe these remains to ursus sp. lower fourth premolar: the lower fourth premolar (fr 89-1) has a very simple morphology, with narrow and elongated external profile. the protoconid is well developed and undivided, unlike the metaconid and the paraconid which are small and poorly developed. the presence of a tubercled area in the occlusal surface is not observed except for one small accessory cusp on 58 conti j. et al. t a b . 2 l is t a n d m e a s u re s o f u rs u s m a te ri a l fr o m t h e f o n ta n a r a n u c c io d e p o s it ( m e a s u re s i n m m ). quiles, 2003; madurell-malapeira et al., 2009; rabeder et al., 2010; wagner & čermák, 2012; arsuaga et al., 2014; prat-vericat et al., 2020). this simpler morphology is related to the early pleistocene etruscan bear u. etruscus, characterized by the lack of accessory cusps or tubercled structures in the chewing surface of molariforms, and considered as ancestor of both lineages (wagner & sabol, 2007). the teeth of the late pleistocene cave bear (ursus ex gr. spelaeus) show instead a higher complexity of the chewing surface (fig. 4 k-l), contrary to what is observed in the late pleistocene and extant brown bears, which possess a simpler and secodont morphology of the occlusal surface through time (fig. 4 m-n-o-p). these differences are probably related with the dietary habits of the two bear lineages, one omnivorous (u. arctos) and the other mostly herbivorous (u. spelaeus) (terlato et al., 2018). biometric analyses did not allow any specific discrimination regarding the middle pleistocene specimens (fig. 3 b), while the dimensional range of u. the lingual portion of the protoconid slope. all these features occur in the arctoid tooth morphology and can be found also in the late pleistocene and recent ursus arctos (reynolds, 1906; torres, 1988; capasso barbato et al., 1990; mazza & rustioni, 1994; quiles, 2003; meloro, 2007; rabeder et al., 2010). u. deningeri can display a higher morphological complexity of the occlusal surface characterized by many tubercles and by a much more elliptic external profile (fig. 4 e-f-g-i), even if many remains such as the early middle pleistocene specimens from the site of hundsheim (austria, hh 305), c718 cave (czech republic, rv 20003) (fig. 4 d-h), and some other specimens recorded from sima de los huesos (spain, middle pleistocene, ca. 0.35 ma), caune de l’arago, (france, middle pleistocene, ca. 0.50 ma), cal guardiola (spain, latest early pleistocene, ca. 1.2-0.86 ma), display a p4 without any accessory cuspids and simpler morphology, remarking the high variability and the possible presence of ancestral characters displayed by u. deningeri (garcía et al., 1997, 2007; 59 review of ursus material from fontana ranuccio (middle pleistocene, central italy) fig. 2 ursus material from fontana ranuccio in occlusal and lateral views: a) m1 right (fr 06-411), b) fr m1 left (fr 56574), c) p4 right (fr 89-1), d) m2 left (fr sd-1), e) m3 right (fr 56575), f) i3 left (fr 82-2 res), g) i3 right (fr 85-2 p3), h) i2 right (fr sd-2), i) c right (fr 85-1 s1), l) m2 left (fr 84-1), m) m1 left (fr 96-33), n) iii phalanx right (fr 84 inv 56576). 60 conti j. et al. fig. 3 comparison of the length and width scatter plots of various early and middle pleistocene species of the genus ursus. a) m1; b) p4; c) m2; d) m3. deningeri and u. arctos strongly overlap (also due to the lack of sufficient data of the early/middle pleistocene ursus arctos). as mentioned above, a simple morphology, with the lack of accessory cusps in the lower p4 is a shared character between ursus arctos and ursus deningeri, specially during the late early-middle pleistocene (wagner et al., 2017). despite the presence of ursus deningeri in the deposit, the large variability of the morphology and biometric data do not allow a specific attribution of the isolated p4. to be more conservative we ascribe fr 98-1 to ursus sp. ursus deningeri von reichenau, 1904 referred material: m1 left (fr 56574), m1 right (fr 06-411), m2 left (fr sd-1), m3 right (fr 56575). upper first molars: the specimen fr 56574 (fig. 2 b) shows sub-quadrangular profile with a non-rectilinear protocone-hypocone line and the presence of some tubercled structures on the talon surface. the central constriction of the tooth is rather marked especially in the lingual portion and the main cusps are well developed. the biometric data show, as expected, an overlap between the deningeroid and arctoid specimens; despite this, we can observe that fr 56574 falls within the dimensional range mostly occupied by the early-middle pleistocene u. deningeri (fig. 3 a) and showing a rather large size of this tooth compared to the average dimension of u. arctos. the specimen fr 06-411 (fig. 2 a) has some different features from fr 56574. the metastyle and the parastyle are well developed, the metastyle more than the parastyle, and the talon shows a tubercled surface, more than fr 56574. on the other hand, the tooth has a quadrangular shape, the distal and proximal area show the same profile and the protocone-hypocone line appears quite straight. biometric analyses indicate that the specimen is placed at the limit of the average dimensional range of u. arctos, falling within the variability of u. deningeri (fig. 3 a). the occlusal surface of both teeth displays tubercles, a common speloid feature (capasso barbato et al., 1990; quiles, 2003). according to torres (1984) and capasso barbato et al. (1990) the straight protocone-hypocone line of fr 06-411 should be related to the arctoid lineage. the latter assumption stands up against the morphological comparison here proposed (fig. 5), in fact specimens of u. deningeri from hundsheim (fig. 5 e-f) show the same straight protoipoconid line, more than brown bear, which instead presents a consistent variability for this character. considered all these morphological and biometric features, we ascribe these specimens to u. deningeri. second lower molar: the specimen fr sd-1 (fig. 2 d) is characterized by a high complexity of the occlusal surface with the presence of numerous tubercled structures and accessory cusps, well representing the typical cave bear morphology (fig. 6) consisting of a metaconid d i v i d e d i n t o t h r e e metastylids, typical of u. deningeri and u. ex gr. spelaeus (capasso barbato et al., 1990; quiles, 2003; torres, 1988). the biometric analysis still indicates a straight dimensional overlap between u. deningeri and u. arctos, which does not allow to distinguish the two species based on size. the specimen fr sd-1 falls perfectly in this overlap range (fig. 3 c). concerning the morphological features of the m2 from fontana ranuccio we ascribe this specimen to u. deningeri. lower third molar: the specimen fr 56575 shows a quadrangular outline with a rounded talonid. the occlusal surface is highly tubercled, typical of the speloid lineage (capasso barbato et al., 1990; quiles, 2003; torres, 1988) (fig. 7). the tooth shows low worn structures and a well-developed entoconid and metaconid, the latter is composed by two distinct cusps. biometric data also suggest the affinity of the specimen with the speloid group, fitting within the dimensional range of u. deningeri (fig. 3 d). according to both morphological and biometric analyses, we ascribe this specimen to u. deningeri. 5. discussion and final remarks the presence of u. deningeri is confirmed at fontana ranuccio, as already proposed by biddittu et al., (1979) and cassoli & segre naldini, (1993). this species is widely distributed throughout europe and quite well represented in italy during the middle pleistocene (fig. 8). u. deningeri was a medium-large sized bear generally deemed as the ancestor of ursus spelaeus s.l. the transition between these two species occurred during the middle late pleistocene transition, so far these taxa are considered two chronospecies, phylogenetically closely related (sardella et al., 2006, valdiosera et al., 2007). from molecular studies a complex scenario emerges during the late pleistocene, with three different evolutionary lines: u. spelaeus, u. ingressus and u. deningeri kudarensis (knapp et al., 2009). late pleistocene cave bear in particular retained the same character of the middle pleistocene deninger bear, even if more marked, 61 review of ursus material from fontana ranuccio (middle pleistocene, central italy) fig. 4 comparison of the p4: a) ursus arctos (left), da-4b 18-36 (deutsch-altenburg, early pleistocene); b) ursus etruscus (right, mirrored in the table), igf 911 (valdarno, early pleistocene); c) ursus etruscus (left), igf 4605 (valdarno, early pleistocene); d) ursus deningeri (left), hh 305 (hundsheim, early middle pleistocene); e) ursus deningeri (left), hh 306 (hundsheim, early middle pleistocene); f) ursus deningeri (left), rv 20003 (koněprusy caves, early middle pleistocene); g) ursus deningeri (left), rv 20005 (koněprusy caves, early midde pleistocene); h) ursus deningeri (left), n.c. (isernia la pineta, early middle pleistocene); i) ursus deningeri (left), specimen h (sandalja, middle pleistocene); j) fr 89-1 (right, mirrored in the table) (fontana ranuccio, middle pleistocene); k) ursus savini nordostensis ssp. (left), iam f-2365 (ovrag, late pleistocene); l) ursus spelaeus (left), p3021 (caverna delle fate, late pleistocene); m) ursus arctos (left), zin 34595 (kudaro 3, late pleistocene); n) ursus arctos (left), v.1152 (vigna s. carlo, late pleistocene); o) ursus arctos (left), 3399 (alps, recent); p) ursus arctos (right, mirrored in the table), 3362 (alps, recent). abbreviations: med metaconid, prd protoconid, pad paraconid. as the broad, domed, steep forehead, that result in a ‘step’ in the midsagittal plane (santos et al., 2017). during the middle pleistocene, u. arctos has been reported in some italian localities: bucine (upper valdarno, tuscany; mazza, 1998), riparo del poggio (salerno; boscato et al., 2009), acquedolci and contrada camillà (sicily; bonfiglio et al., 2001; marra, 2003; pavia, 2001) (fig. 8). the brown bear record from riparo del poggio is composed only by two elements (one indeterminate tooth and a phalanx), the deposit consists in a shelter which was part of a complex underground karst system, which was partially dismantled by sea erosion. the ursus arctos material come from the lower level dated to the cold phase of mis 6 (boscato et al., 2009). the cranium from bucine comes from one of many small fossiliferous deposits as poggio amaro, le capannelle, pogi di bucine, capannole, migliorini, cava di bucine, cava le vigne, cava del rinoceronte, mostly situated along the ambra creek, a left-hand tributary of the arno river, and excavated since the 1940. no information is available on the exact locality where the cranium of u. arctos was recovered, but all the fossil remains are dated around the late middle pleistocene (referable to the saalian cycle, from 340 ky to 120 ky ago; mazza, 62 conti j. et al. fig. 5 comparison of the m1. a) fr 06-411 (right). b) fr 56574 (left, mirrored in the table). c) u. deningeri (left, mirrored in the table), hh/5/342 (hundsheim, middle pleistocene) d) u. deningeri (left, mirrored in the table), hh/5/398, (hundsheim, middle pleistocene). e) u. arctos (left, mirrored in the table), da4b/18 (deutsch-altenburg, early pleistocene). f) u. arctos (right), da4v/14 (deutsch-altenburg, early pleistocene). g) u. arctos priscus (right), w s.1 (winden, late pleistocene). h) u. arctos (left, mirrored in the table), c. 4 (banskà bystrica, recent). i) u. arctos (right), igf 10961 (bucine, late middle pleistocene). e-f-g-c) modified from rabeder et al. (2010). fig. 7 comparison of the m3. a) fr 56575 (right). b) u. arctos (left, mirrored in the table), c.4, (banská bystrica, recent). c) u. deningeri (left, mirrored in the table), mf/1346/45 (kozi grzbiet, middle pleistocene). d) u. deningeri (left, mirrored in the table), hund 382 (hundsheim, middle pleistocene). fig. 6 comparison of the m2. a) fr 84-1 (left). b) fr sd-1 (left). c) u. arctos (right, mirrored in the table), 3364 (alps, recent). d) u. deningeri (right, mirrored in the table), 1889/5/404 (hundsheim, middle pleistocene). e) u. deningeri (left), mf/1346/37 (kozi grzbied, middle pleistocene), modified from wagner et al. (2012). 1998). the bear remains from sicily have been excavated in the last forty years, and have been found associated with cervus elaphus siciliae and elephas mnaidriensis, dated to the late middle pleistocene/late pleistocene (e. mnaidriensis faunal complex, from early mis 6 to mis 4 stages; bonfiglio et al., 2001, 2003). the occurrence of the brown bear is also documented in some other sites of the north/eastern italian peninsula (see bon et al., 1991), however this material needs further chronological and systematic analyses. since the uncertain dating of these deposits, it is possible to hypothesize that the bucine specimen could be the f.o. of the brown bear in the italian peninsula. a recent paleoenvironmental reconstruction based on dietary adaptations of ungulates from fontana ranuccio suggests that a mosaic of both closed and open landscapes characterized this locality around 0.4 ma with a relative abundance of soft plant resources and probably affected by a marked seasonality (strani et al., 2018a; strani et al., 2019; strani, 2020; strani et al., 2021). a heterogeneous environment could have favored the coexistence of two different bear species in the area, which may have lived in sympatric conditions exploiting different trophic resources as largely documented in several late pleistocene localities of the italian peninsula (capasso barbato et al., 1990; minieri et al., 1995; palombo et al., 2002; mazza et al., 2005). although palaeoecological considerations allow the presence of the two species, paleontological data do not show with any reliable evidence of the presence of ursus arctos. the fossils from fontana ranuccio represent the lo of ursus deningeri in italy. new excavations are still ongoing carried on by isipu and new findings will better address many unsolved questions and shed new light on the distribution and evolution of bears in europe. acknowledgements we are very grateful to the italian institute of human paleontology for granting access to the material and for the continuous assistance during the analyses. we would like to express also gratitude to martin sabol (comenius university, bratislava), for advising and the inspiring discussion that made possible this work. we also thank the muse (museo delle scienze of trento), the parco nazionale d’abruzzo, lazio e molise, the department of geology and paleontology of comenious university (bratislava, slovakia), the slovak museum of nature protection and speleology (liptovský mikuláš, slovakia), the national history museum (wien, austria), the department of paleontology of wien university (wien, austria), for granting access to fossil and extant bear material used for morphological comparisons. we thank chiara delpino of soprintendenza archeologia belle arti e paesaggio per le province di frosinone, latina e rieti (ministero della cultura) and the italian institute of human paleontology for granting access to 63 review of ursus material from fontana ranuccio (middle pleistocene, central italy) fig. 8 distribution of the fossil bears during the middle pleistocene of the italian peninsula. 1) venosa (van heteren et al., 2019). 2) bristie i (lugli & sala, 2000). 3) cava rinaldi (petronio et al., 2019). 4) cretone (petronio et al., 2011). 5) fontana ranuccio (this work). 6) isernia la pineta (peretto & sala, 2019). 7) ponte molle (petronio et al., 2011). 8) slivia (bon et al., 1991; petronio et al., 2011). 9) valdemino (ghezzo et al., 2015). 10) visogliano (tozzi et al., 2000). 11) cava nord (soave) (rustioni & mazza, 1993). 12) cengelle 1 (soave) (rustioni & mazza, 1993). 13) castello (soave) (rustioni & mazza, 1993). 14) cerè (ghezzo et al., 2013; rossi & santi, 2011). 15) selva vecchia (van heteren et al., 2019). 16) sorbano di romagnano (bon et al., 1991). 17) fornace di cornedo (rustioni & mazza, 1993). 18) grotta di san bernardino (bon et al., 1991). 19) acquedolci (marra, 2003). 20) contrada camilla (marra, 2003). 21) bucine (mazza, 1997; petronio et al., 2019). 22) castel di guido (caloi et al., 1998). 23) prati fiscali (petronio et al., 2011). 24) fara sabina (petronio et al., 2011). 25) riparo del poggio (boscato et al., 2009). 64 conti j. et al. the palaeontological collections of fontana ranuccio.". we'd like to thank the two reviewers for providing useful comments that allowed us to improve our manuscript. jc acknowledges sapienza, university of rome for the funds provided by the call “bando per il finanziamento di progetti di ricerca congiunti per la mobilità all’estero di studenti di dottorato del xxxi e xxxii ciclo n. 2682/2017”, that allowed the acquisition of part of the data present in this work. references ambrosetti p., bartolomei g., de giuli c., ficcarelli g., torre d. (1979) la breccia ossifera di slivia (aurisina-sistiana) nel carso di trieste. bollettino della società paleontologica italiana, 18(2), 207220. argant a. (1991) carnivores quaternaires en bourgogne. doc. lab. géol. lyon, 115, pp. 301. arsuaga j.l., martínez i., arnold l.j., aranburu a., gracia-téllez a., sharp w.d., quam r.m., falguères c., pantoja-pérez a., bischoff j., poza-rey e., parés j.m., carretero m., demuro m., lorenzo c., sala n., martinón-torres m., garcía n., alcázar de velasco a., cuenca-bescós g., gómez-olivencia a., moreno d., pablos a., shen c., rodríguez l., ortega a.i., garcía r., bonmatí a., bermúdez de castro j.m., carbonell e. (2014) neandertal roots: cranial and chronological evidence from sima de los huesos. science, 344(6190), 1358-1363. auguste p. (1995) cadres biostratigraphiques et paléoécologiques du peuplement humain dans la france septentrionale durant le pléistocène: apports de l’étude paléontologique des grands mammifères du gisement de biache-saint-vaast (pasde-calais). doctoral dissertation, paris, muséum national d’histoire naturelle, pp. 1924. azzaroli a. (1983) quaternary mammals and the “endvillafranchian” dispersal event a turning point in the history of eurasia. palaeogeography, palaeoclimatology, palaeoecology, 44(1-2), 117-139. ballesio r. (1983) le gisement pléistocène supérieur de la grotte de jaurens à nespouls (corrèze) : les carnivores. nouvelles archives dumuséum d’histoire naturelle de lyon, 21, 9-43. baryshnikov g.f. (2010) late pleistocene brown bear (ursus arctos) from the caucasus. russian journal of theriology, 9(1), 9-17. biddittu i., cassoli p.f., radicati di brozolo f., segre a.g., segre naldini e., villa i. (1979) anagni a k/ ar dated lower middle pleistocene site, central italy: preliminary report. quaternaria, 21, 53-71. bon m., piccoli g., sala b. (1991) i giacimenti quaternari di vertebrati fossili nell’italia nord-orientale. mem. se. geol. padova, 43, 185-231. bona f., strani f. (2021) new data on the middle pleistocene small mammal fauna from the homo bearing site of fontana ranuccio (anagni basin, central italy). alpine and mediterranean quaternary, 34 (1), 69-74. bonfiglio l., mangano g., marra a.c., masini f. (2001) a new late pleistocene vertebrate faunal complex from sicily (s. teodoro cave, north-eastern sicily, italy). bollettino della società paleontologica italiana, 2, 149-158. bonfiglio l., di maggio c., marra a., masini f., petruso d. (2003) bio-chronology of pleistocene vertebrate faunas of sicily and correlation of vertebrate bearing deposits with marine deposits. il quaternario, 16(1), 107-114. borselli v., de giuli c., ficcarelli g., mazzini m. (1980) casa frata: una località fossilifera del villafranchiano superiore presso terranuova bracciolini (arezzo) nel valdarno superiore. bolletino della società paleontologica italiana, 19(2), 245-258. boscato p., boschian g., caramia f., gambassini p. (2009) il riparo del poggio a marina di camerota (salerno): culture ambiente. rivista di scienze preistoriche, 59(2009), 5-40. caloi l., palombo m.r., zarlenga f. (1998) latemiddle pleistocene mammal faunas of latium (central italy): stratigraphy and environment. quaternary international, 47, 77-86. capasso barbato l., minieri m.r., petronio c., vigna taglianti a. (1990) strutture dentarie di ursus arctos e di ursus spelaeus della grotta di monte cucco (sigillo, perugia, italia). bollettino della società paleontologica italiana, 29, 335-356. cassoli p.f., segre naldini e. (1993) le faune villafranchiane: costa san giacomo e fontana acetosa. dives anagnia. l’erma di bretscheider, roma, 31-33. conti j. (2019) evolution of cranio-dental features and distribution of brown bear (ursus arctos l., 1758) in europe. ph.d. thesis. sapienza university of rome, pp. 177. conti s. (1954) morfologia comparata craniale ed encefalica degli orsi pleistocenici della liguria. memorie del museo civico di storia naturale “g. doria” genova, pp. 86. cuvier g. (1823) recherches sur les ossemens fossililes de quadrupédes. paris, 5(1). devèze de chabrol j.s., bouillet j.b. (1827) essai géologique et minéralogique sur les environs d'issoire, département du puy-de-dôme, et principalement sur la montagne de boulad, avec la description et les figures lithographiées des ossemens fossiles qui y ont été recueillis. ursidae. thibaudlandriot, clermont-ferrand, pp. 140. di stefano g., petronio c., sardella r. (1994) il significato biocronologico e paleoecologico di alcuni taxa di mammiferi del plio-pleistocene dell’italia centrale. studi geologici camerti, volume speciale 1994 “biostratigrafia dell’italia centrale”. università degli studi di camerino, camerino, 459-467. ferretti m. (1997) mammuthus cf. primigenius (proboscidea, mammalia), a new faunal element from the late middle pleistocene of conca river (cattolica, romagna, italy). bollettino della società paleontologica italiana, 36(3), 391-398. florindo f., marra f., angelucci d.e., biddittu i., bruni l., florindo f., gaeta m., guillou h., jicha b., macrì p., morigi c., nomade s., parenti f., pereira a., grimaldi s. (2021) environmental evolution, faunal and human occupation since 2 65 review of ursus material from fontana ranuccio (middle pleistocene, central italy) ma in the anagni basin, central italy. scientific reports, 11(1), 7056. garcía n., arsuaga j.l., torres t.d. (1997) the carnivore remains from the sima de los huesos middle pleistocene site (sierra de atapuerca, spain). journal of human evolution, 33(2-3), 155-174. garcía n., santos e., arsuaga j.l., carretero j.m. (2007) endocranial morphology of the ursus deningeri von reichenau 1904 from the sima de los huesos (sierra de atapuerca) middle pleistocene site. journal of vertebrate paleontology, 27 (4), 1007-1017. ghezzo e., berté d., sala b. (2013) the revalutation of galerian canidae, felidae and mustelidae of the ceré cave (verona, northeastern italy). quaternary international, 339-340, 76-89. ghezzo e., boscaini a., madurell-malapeira j., rook l. (2015) lynx remains from the pleistocene of valdemino cave (savona, northwestern italy), and the oldest occurrence of lynx spelaeus (carnivora, felidae). rendiconti lincei, 26(2), 8795. gliozzi e., abbazzi l., argenti p., azzaroli a., caloi l., capasso barbato l., di stefano g., esu d., ficcarelli g., girotti o., kotsakis t., masini f., mazza p., mezzabotta c., palombo m.r., petronio c., rook l., sala b., sardella r., zanalda e. torre d. (1997) biochronology of selected mammals, molluscs and ostracods from the middle pliocene to the late pleistocene in italy. the state of the art. rivista italiana di paleontologia e stratigrafia, 103(3), 369-388. grimaldi s., santaniello f., angelucci d.e., bruni l., parenti f. (2020) a techno-functional interpretation of the lithic assemblage from fontana ranuccio (anagni, central italy): an insight into a mis 11 human behaviour. journal of paleolithic archaeology, 3, 944–966. knapp m., rohland n., weinstock j., baryshnikov g., sher a., nagel d., rabeder g., pinhasi r., schmidt h.a., hofreiter m. (2009) first dna sequences from asian cave bear fossils reveal deep divergences and complex phylogeographic patterns. molecular ecology, 18(6), 1225-1238. linnaeus c. (1758) systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. 1 (10th ed.). laurentius salvius, stockholm. pp. 824. lugli c., sala b. (2000) la teriofauna del pleistocene medio di bristie i°(carso triestino). atti del museo civico di storia naturale di trieste, 48, 35-58. madurell-malapeira j., alba d.m., moyà-solà s. (2009) carnivora from the late early pleistocene of cal guardiola (terrassa, vallès-penedès basin, catalonia, spain). journal of paleontology, 83(6), 969974. marra a.c. (2003) ursus arctos from selected pleistocene site of eastern sicily. bollettino della società paleontologica italiana, 42(1-2), 145-150. masini f., sala b., ambrosetti p., azzaroli a., ficcarelli g., kotsakis t., rook l., torre d. (1991) mammalian faunas of selected villafranchian and galerian localities. in: inqua seqs, subcommission for european quaternary stratigraphy, cromer symposium, norwich., uk, 3-7 september 1990. mazza p. (1998) taphonomic analysis of late middle pleistocene mammal remains from bucine. bollettino della società paleontologica italiana, 36, 381390. mazza p., rustioni m. (1994) on the phylogeny of eurasian bears. palaeontographica, 230, 1-38. mazza p. (1997) taphonomic analysis of late middle pleistocene mammal remains from bucine. bollettino della società paleontologica italiana, 36, 381390. mazza p., rustioni m., agostini s., rossi a. (2005) an unexpected late pleistocene macaque remain from grotta degli orsi volanti (rapino, chieti, central italy). geobios, 38(2), 211-217. mecozzi b., iannucci a., mancini m., sardella r. (2021) redefining ponte molle (rome, central italy): an important locality for middle pleistocene mammal assemblages of europe. alpine and mediterranean quaternary, 34(1), 131-154 doi: 10.26382/amq.2021.09 meloro c. (2007) la fauna quaternaria di grotta milano (petina, salerno). atti i convegno regionale di speleologia “campania speleologica” 1-3 giugno 2007 oliveto citra (sa), pp. 75-83. minieri m., petronio c., sardella r., scarano m. (1995) le faune a mammiferi del pleistocene superiore dell’italia peninsulare. quaderni padusa, 1, 75-87. palombo m.r., azanza b., alberdi m.t. (2002) italian mammal biochronology from latest miocene to middle pleistocene: a multivariate approach. geologica romana, 36, 335-368. pavia m. (2001) the middle pleistocene fossil avifauna from the “elephas mnaidriensis faunal complex” of sicily (italy): preliminary results. in 1° congresso internazionale: "la terra degli elefanti", roma 16-20 ottobre 2001, 497-501. peretto c., sala b. (2019) isernia la pineta (isernia). annali dell’università di ferrara. sezione: museologia scientifica e naturalistica, 15, 31-38. pereira a., nomade s., moncel m.h., voinchet p., bahain j.j., biddittu i., falguères c., giaccio b., manzi,g., parenti f., scardia g., scao v., sottili g., vietti a. (2018) integrated geochronology of acheulian sites from the southern latium (central italy): insights on human-environment interaction and the technological innovations during the mis 11-mis 10 period. quaternary science reviews, 187, 112-129. doi: 10.1016/j.quascirev.2018.03.021 petronio c., di canzio e., salari l. (2007) the late pleistocene and holocene mammals in italy: new biochronological and paleoenvironmental data. palaeontographica, abt. a, 279, 147-157. petronio c., bellucci,l., martinetto e., pandolfi l., salari l. (2011) biochronology and palaeoenvironmental changes from the middle pliocene to the late pleistocene in central italy. geodiversitas, 33(3), 485-517. petronio c., di stefano g., kotsakis t., salari l., marra f., jicha b.r. (2019) biochronological framework 66 conti j. et al. for the late galerian and early-middle aurelian mammal ages of peninsular italy. geobios, 53, 3550. petronio c., angelone c., atzori p., famiani f., kotsakis t., salari l. (2020) review and new data of the fossil remains from monte peglia (late early pleistocene, central italy). rivista italiana di paleontologia e stratigrafia, 126 (3), 791-819. petrucci m., sardella r. (2009) ursus etruscus cuvier, 1823 from the early pleistocene of monte argentario (southern tuscany, central italy). bollettino della società paleontologica italiana, 48(2), 89-94. prat-vericat m., rufí i., llenas m., madurell-malapeira j. (2020) middle pleistocene ursus deningeri from grotte de la carrière (réseau lachambre, têt valley, eastern pyrenees). journal of iberian geology, 46(2), 163-175. quiles j. (2003) les ursidae du pléistocène moyen et supérieur en midi méditerranéen: apports paléontologiques, biochronologiques et archéozoologiques. doctoral dissertation, paris, muséum national d’histoire naturelle, pp. 1307. rabeder g. (1999) die evolution des höhlenbärengebisses. verlag der österr. akad. der wiss., 11, 1102. rabeder g., pacher m., withalm g. (2010) early pleistocene bear remains from deutsch-altenburg (lower austria). mitteilungen der kommission für quartärforschung der österreichischen akademie der wissenschaften, 17, 1-135. von reichenau w. (1904) beiträge zur näheren kenntniss der carnivoren aus den sanden von mauer and mosbach. abhandlungen der grossherzolich hessischen geologischen landesanstalt zu darmstadt. 4(2), 14. reynolds s.h. (1906) monograph of british mammalia of the pleistocene period. the bears. london palaeontographical society, 2, 1-35. rosenmüller j. (1794) quaedam de ossibus fossilibus animalis cuiusdam, historiam eius et cognitionem accurationrem illustrantia. thesis, leipzig, pp. 34. rossi m., santi g. (2011). ursus deningeri-spelaeus group from cerè cave (veneto, north italy) in the new evolutionary frame of the cave bear. part one: skulls and mandibles. annalen des naturhistorischen museums in wien. serie a für mineralogie und petrographie, geologie und paläontologie, anthropologie und prähistorie. naturhistorischen museum, wien, 567-590. rubini m., cerroni v., festa g., sardella r., zaio p. (2014) a revision of hominin fossil teeth from fontana ranuccio (middle pleistocene, anagni, frosinone, italy). journal of human evolution, 77, 204-216. doi: 10.1016/j.jhevol.2014.09.002 rustioni m., mazza p. (1993) the tibetan-like bear from grotta di reale, porto azzurro (isle of elba, italy). il quaternario, 6(1), 35-38. santos e., gómez-olivencia a., arlegi m., arsuaga j.l. (2017) cranial morphological differences within u. deningeri u. spelaeus lineage: a double traditional and geometric morphometrics approach. quaternary international. 433, 347-362. sardella r., palombo m.r., petronio c., bedetti c., pavia m. (2006) the early middle pleistocene large mammal faunas of italy: an overview. quaternary international, 149(1), 104-109. segre a.g. (1984) considerazioni sulla cronostratigrafia del pleistocene laziale. atti della xxiv riunione scientifica dell’istituto italiano di preistoria e protostoria, istituto italiano di preistoria e protostoria, firenze, 149-154. sher a. v., weinstock j., baryshnikov g. f., davydov s. p., boeskorov g. g., zazhigin v. s., nikolskiy p. a. (2011). the first record of “spelaeoid” bears in arctic siberia. quaternary science reviews, 30(17 -18), 2238-2249. stiner m.c. (1998) mortality analysis of pleistocene bears and its paleoanthropological relevance. journal of human evolution, 34(3), 303-326. strani f. (2020) impact of early and middle pleistocene major climatic events on the palaeoecology of southern european ungulates. historical biology, in press. doi: 10.1080/08912963.2020.1782898 strani f., demiguel d., bona f., sardella r., biddittu i., bruni l., de castro a., guadagnoli f., bellucci l. (2018a) ungulate dietary adaptations and palaeoecology of the middle pleistocene site of fontana ranuccio (anagni, central italy). palaeogeography, palaeoclimatology, palaeoecology, 496, 238-247. doi: 10.1016/j.palaeo.2018.01.041 strani f., profico a., manzi g., pushkina d., raia p., sardella r., demiguel d. (2018b) microwear: a new r package for dental microwear analysis. ecology and evolution, 8, 7022-7030. strani f., pushkina d., bocherens h., bellucci l., sardella r., demiguel d. (2019) dietary adaptations of early and middle pleistocene equids from the anagni basin (frosinone, central italy). frontiers in ecology and evolution, 7, 176. strani f., bellucci l., iannucci a., iurino d.a., mecozzi b., sardella r. (2021) palaeoenvironments of the mis 15 site of cava di breccia casal selce 2 (central italian peninsula) and niche occupation of fossil ungulates during middle pleistocene interglacials. historical biology, in press. doi: 10.1080/08912963.2021.1935920 terlato g., bocherens h., romandini m., nannini n., hobson k.a., peresani m. (2018) chronological and isotopic data support a revision for the timing of cave bear extinction in mediterranean europe. historical biology, 31(4), 474-484. torres p. (1984) ursidos del pleistoceno-holoceno de la península ibérica. doctoral dissertation, e.t.s.i. minas (upm) pp. 653. torres p. (1988) osos (mammalia, carnivora, ursidae) del pleistoceno ibérico (u. deningeri von reichenau, u. spelaeus rosenmüller-heinroth, u. arctos linneo). boletín geológico y minero, 99, 4-940. tozzi c., falgueres c., mallegni f., masini f., negrino f. (2000) les industries du paléolithique inférieur de visogliano, trieste, italie, dans leur contexte stratigraphique, biostratigraphique et géochronolo wagner j., čermák s. (2012) revision of the early middle pleistocene bears (ursidae, mammalia) of central europe, with special respect to possible co -occurrence of spelaeoid and arctoid lineages. bulletin of geosciences, 87(3), 461-496. wagner j., jiangzuo q., lenardić j.m., liu j. (2017) taxonomic revision of bears from the locality šandalja i (croatia) and its biostratigraphic consequences. fossil imprint (formerly acta musei nationalis pragae, series b-historia naturalis), 73(34), 533-544. gique. les prémiers habitants de l'europe, tautavel 10-15 avril 2000, resumen de communications, pp. 104. valdiosera c.e., garcía n., anderung c., dalén l., crégut-bonnoure e., kahlke r.d., stiller m., brandström m., thomas m.g., arsuaga j.l., götherström a., barnes i. (2007) staying out in the cold, glacial refugia and mitochondrial dna phylogeography. molecular ecology, 16, 51405148. van heteren a.h., arlegi m., santos e., arsuaga j.l., gómez-olivencia a. (2019) cranial and mandibular morphology of middle pleistocene cave bears (ursus deningeri): implications for diet and evolution. historical biology, 31(4), 485-499. wagner j., sabol m. (2007) remarks on biharian bears (ursidae: ursus) from the territory of slovakia. scripta facultatis scientiarum naturalium universitatis masarykianae brunensis, 35, 159164. 67 review of ursus material from fontana ranuccio (middle pleistocene, central italy) ms. received: november 17, 2020 revised: march 23, 2021 accepted: june 3, 2021 available online: july 8, 2021 68 06bellottietal. insediamenti umani in un paesaggio in evoluzione: interazione uomo-ambiente nella piana di sibari (calabria ionica) piero bellotti1, claudio caputo1, pier luigi dall’aglio2, lina davoli1, kevin ferrari2 1dipartimento di scienze della terra – “sapienza” università di roma, e-mail: piero.bellotti@gmail.com 2dipartimento di archeologia – università di bologna riassunto: p. bellotti, et al., insediamenti umani in un paesaggio in evoluzione: interazione uomo-ambiente nella piana di sibari (calabria ionica). (it issn 0394-3356, 2009). la piana di sibari è ubicata sulla costa ionica della calabria in un’area dalla tettonica complessa e tuttora attiva. la sua recente evoluzione geologica è stata guidata dai tassi di subsidenza e di risalita eustatica del livello marino nonché da quelli degli apporti fluviali, in particolare dei fiumi crati e coscile. durante l’olocene l’area si è trasformata, attraverso ripetute fasi di progradazione, da un’articolata insenatura ad una piana costiero/deltizia con sviluppo di aree lagunari/palustri la cui persistenza è stata favorita dai forti tassi di subsidenza. l’area è oggi caratterizzata dal delta del f. crati, che mostra una conformazione bialare cuspidata, e da una serie di conoidi di deiezione che ne listano il margine interno. già nel neolitico inferiore, in località favella della corte, era presente un insediamento sulla sommità di un terrazzo le cui scarpate costituivano una ripa al cui piede si stendeva una spiaggia. il f. crati sfociava in mare circa 5-6 km più ad ovest dell’attuale linea di riva e circa 2 km più a sud dell’attuale corso. il villaggio di favella della corte, ampio circa 40000 m2, risulta frequentato nel neolitico antico e recente, ma non in quello medio quando iniziarono invece ad essere frequentate alcune grotte del circondario. con il passaggio all’eneolitico viene invece totalmente abbandonato e, fino all’età arcaica, mancano insediamenti in prossimità della costa. in epoca arcaica il paesaggio appare diverso. tra i corsi dei fiumi crati e coscile, su un cordone dunare ad andamento meridiano che bordava un’area lagunare, venne fondata la città di sybaris. il f. crati aveva spostato lentamente il suo corso verso nord di quasi 3 km sfociando temporaneamente anche nell’area lagunare di sybaris e, a causa anche di una variazione climatica in senso fresco-umido, esondò ripetutamente e consistentemente favorendo anche la progradazione della foce di almeno 2 km. il popolamento era in gran parte concentrato nella metropoli achea al riparo dalle piene per la sua posizione e per le imponenti opere di bonifica e regimazione dei fiumi. nel 510 a.c. una guerra con crotone portò alla distruzione della città e alla perdita del controllo idraulico dell’area e per i sessanta anni successivi manca ogni documentazione archeologica relativa alla frequentazione della piana. tra il 2400 e il 1400 bp il paesaggio muta ancora. il miglioramento climatico, che perdurò fino alla fase calda romana potrebbe aver diminuito gli eventi alluvionali ed essere concausa della riduzione dei tassi di progradazione della foce del f. crati e anche della ridotta distanza esistente tra i beach ridges attribuiti a questo periodo. nel 444÷3 a.c. viene fondata una nuova città (thurii) in parziale sovrapposizione con la distrutta sybaris. questo testimonia come la zona, nonostante la situazione climatica non fosse ancora tornata favorevole, fosse nuovamente in stato di sicurezza idraulica. il popolamento si distribuisce tra il centro abitato (chiamato copia dopo la conquista romana) e una serie di fattorie e ville. durante la conflittualità punica gli insediamenti della piana di sibari entrarono in sofferenza e l’area urbana si ridusse. intorno al 1800 bp il nuovo peggioramento climatico potrebbe aver incrementato gli eventi alluvionali favorendo il progressivo riempimento della laguna già in parte usata come porto. la città entra gradualmente in crisi e intorno al vi secolo d.c. (1400 bp) viene abbandonata. il popolamento si attesta in zone collinari, meglio difendibili, e cessa il controllo territoriale della pianura. nell’alto medioevo e soprattutto nel rinascimento la zona divenne paludosa e inospitale. le foci dei fiumi crati e coscile, confluirono e si separarono alternativamente testimoniando l’intenso disordine idrico che afflisse l’area per lungo tempo. a partire dall’alto medioevo la pianura non presenta più insediamenti di qualche rilievo e anche le frequentazioni agricole cessarono in coincidenza della little ice age. l’opera di sistemazione idraulica iniziò nel 1882 e si sviluppò dopo il 1930; oggi l’ala settentrionale presenta numerose strutture insediative mentre il litorale dell’ala meridionale è ancor’oggi poco antropizzato la storia della sibarite mostra come l’evoluzione geomorfologica e quella del popolamento nella piana di sibari, siano strettamente correlate. si evidenzia, dunque, che un ambiente molto dinamico risulta abitabile e controllabile dall’uomo in epoche di relativa stabilità dal punto di vista politico ed economico e quando è presente un potere centrale in grado di coordinare gli sforzi in vista della realizzazione e della successiva manutenzione di infrastrutture per la bonifica e il controllo idrico. abstract: p. bellotti, et al., human settlement in an evolving landscape. man-environment interaction in the sibari plain (ionian calabria). (it issn 0394-3356, 2009). the sybaris plain faces the ionian coast of calabria in an area characterised by a complex and active tectonics. the landscape evolution has been driven by the rates of glacio-eustatic sea level rise, by subsidence and bed-load fluvial discharge mainly of the crati and coscile rivers. during holocene – through several progradation phases – the area switched from a wide embayment into a coastal/delta plain with growth of lagoon/marsh areas, whose persistence due to by high subsidence rates caused by sediment compaction. the present delta plain of the crati river appears cuspate and double-winged. morphological evidences observed show that the southern wing was built mainly by repeated and notable floods of the crati river responsible for burial of beach ridges and filling of coastal ponds. conversely, the northern wing, bordered at its inner edge by the wide torrente raganello alluvial fan, grew mainly by the action of the coscile river filling large barrier-lagoon systems. already during the early neolithic (about 7000 bp) settlements at favella della corte a settlement was placed on the top of a terrace whose scarps formed a cliff, at its foot bordered by a beach. the crati river flowed into the sea at about 5-6 km more to the east of the present shoreline and about 2 km more to the south of the present course. the mouth area prograded more than the northern one fed by the coscile river characterised by a reduced solid discharge. the favella della corte village, about 40000 m2 large, was inhabited during the early and recent neolithic, with an abandonment period during middle neolithic when some caves of the surroundings started being used. entering the eneolithic, the village was completely abandoned. up to archaic times settlements close to the coast are lacking. the scenery changed considerably during the archaic age. between the crati and coscile rivers the town of sybaris was built on a ns trending beach ridge, which was bordering a lagoon area. the crati river slowly migrated northwards for nearly 3 km debouching temporarily into the sybaris lagoon. also because of changes towards cool-moist climatic conditions, the crati river flooded considerably and repeatedly. moreover, the strong fluvial activity allowed the progradation of the mouth for 2 km at least. peopling concentrail quaternario italian journal of quaternary sciences 22(1), 2009 61-72 62 p. bellotti et al. 1 introduzione la piana di sibari si colloca nella porzione più settentrionale del litorale ionico calabrese (fig. 1) e risulta alimentata principalmente dagli apporti del f.crati (il più importante della regione), del f.coscile e di corsi d’acqua minori tra cui il t. raganello ed il t. s. mauro. la piana è limitata verso l’interno da una chiostra di rilievi intagliati da una serie di superfici terrazzate; i terrazzi più bassi, quotati da cucci & cinti (1998) tra 15 e 65 m, risultano spesso obliterati da ampi conoidi di deiezione. dal punto di vista geologico, la piana di sibari è posta al margine ionico dell’arco calabro, tra il massiccio carbonatico del pollino e le propaggini settentrionali di quello metamorfico-igneo della sila immediatamente a sud della linea di sangineto. l’area risente di una complessa tettonica estensionale (che affligge anche il contiguo massiccio del pollino) caratterizzata da differenti sistemi di faglie (principalmente ad andamento nw-se e n-s) il cui movimento ha prodotto fenomeni di rotazione di singoli blocchi. una simile attività tettonica, che sembra essere iniziata già dal tortoniano superiore, ha dato origine a diversi bacini tra cui quello della valle del f. crati e quello di sibari-corigliano (turco et al., 1990; russo & schiattarella, 1992; schiattarella, 1996). in particolare la piana di sibari viene considerata un graben (cherubini et al., 1994), bordato da differenti sistemi di faglie di rilevanza regionale in parte ancora attive (cinti et al., 2002). essa è affetta da una significativa subsidenza le cui cause sono tuttavia da imputare più ad un effetto di compattazione del sedimento che non all’attività tettonica (guerricchio & ronconi, 1997; cherubini et al., 2000; 2005; pagliarulo, 2006). nell’intervallo pleistocene superiore-olocene i tassi della subsidenza tendono a ridursi nel tempo, essi sono valutati mediamente intorno a 1.6 mm/a, nel periodo storico, ma presentano locali variazioni a causa della notevole eterogeneità granulometrica del sottosuolo (pagliarulo, 2007). la subsidenza è stato un fattore di controllo della naturale evoluzione idrografica dell’area nel periodo qui preso in esame (neolitico-attuale). tale evoluzione è stata inoltre controllata sia dalla risalita eustatica del livello marino (lambeck, et al., 2004), in particolare tra 8000 e 6000 bp, sia dall’ormai nota variabilità climatica submillenaria, degli ultimi 5000 anni (lamb, 1982; shackleton, 1988; ortolani & pagliuca, 2007; marabini, 2007). la presenza di fauna litorale nei terreni immediatamente sottostanti le aree archeologiche di thuriicopia (guerricchio & melidoro, 1975) e la notevole variabilità tessiturale dei sedimenti presenti nei venti metri terminali dei sondaggi effettuati nell’area costiera della piana di sibari (dati in parte riportati in cherubini et al.,1994; pagliarulo, 2006, e in parte inediti), lasciano supporre che al termine dell’ultimo sollevamento glacioeustatico (circa 6000 bp) l’area fosse caratterizzata da un’insenatura piuttosto articolata per la presenza di più o meno importanti foci fluviali. la linea di riva decorreva, presumibilmente, prossima all’attuale isoipsa di 25 metri (guerricchio & ronconi, 1997). il parziale colmamento dell’insenatura, che ha portato alla situazione attuale, è avvenuto per lo sviluppo di conoidi prodotti da corsi d’acqua che dissecano la dorsale del gruppo del pollino, ma soprattutto per gli apporti del f. crati che hanno configurato l’attuale delta cuspidato (bellotti et al., 2003). tale processo è avvenuto con un continuo mutare dell’idrografia superficiale com’è tipico di zone poco stabili, dove gran parte dei corsi d’acqua sono di breve e acclive corso e con bacino impostato su terreni a bassa permeabilità. i dati che hanno consentito la stesura della carta morfologica (fig.1) provengono oltre che da un’attenta revisione della letteratura, dalla fotointerpretazione di differenti levate aerofotogrammetriche integrata da rilievi morfologici di terreno. alcune analisi sedimentologiche, condotte sui sedimenti affioranti nell’area archeoted mainly in the big achaean metropolis. from a hydraulic viewpoint, the crati plain became object of an impressive reorganisation work with land reclamation and river management. in 510 bc a war with krotonians caused the destruction of the town and the end of main villages. the following sixty years are lacking in archaeological evidences of peopling in the plain. from 2400 to 1400 bp the landscape changed again. a period of climatic improvement leading to the warm roman stage, might have reduced flood events caused a slow and small progradation of the crati river mouth, and originated new and closer-drawn beach ridges. in 444/443 bc a new town (thurii) was built, partly over the former sybaris. this shows how, even though the climatic situation wasn’t turned favourable yet, that area covered by recent floods, and the whole sybaris plain were safe again. peopling distributed in a centre and in a series of farms spread over the whole region, thanks to the romanization process, started during the 2nd century bc. this process also changed the town of thurii into the colony of copia. during the punic wars all settlements of the sybaris plain suffered a backslash and the urban area underwent a narrowing. about 1800 bp the new climatic deterioration might have increased flood events favouring a gradual filling up of the lagoon already partly used as a harbour. at the end of this period the town gradually entered in the middle of a crisis. government intervention decreased and about 1400 bp copia was abandoned. peopling consolidated on the easier-to-defend hills and terraced areas, and so the territorial control of the plain ceased. the climatic deterioration of the early middle ages and mainly of the renaissance brought the area to become marshy and inhabitable. the mouths of crati and coscile rivers underwent frequent changes, in turns dividing and joining again; this shows the high hydraulic disorder, which affected for a long while the region. starting from the early middle ages the plain didn’t had important centres; some evidence of few presence for agricultural purpose existed until the 12th century but, coinciding with the little ice age, this presence stopped. still in the 19th century the sybaris plain was described as a malarial land, marshy and subject to hydraulic disorder. the hydraulic land rehabilitation started in 1882 and developed after 1930. today the northern wing of the crati river shows several settlements, while these are very scarce along the southern one. the history of the sybaris plain shows how geomorphologic and peopling evolution are strictly correlated. therefore it turns out how a very dynamic environment becomes habitable and controlled by man during epochs of relative political and economic stability. this occurs also when a central authority exists, able to co-ordinate efforts in sight of the realisation and following maintenance of infrastructures for reclamation and hydraulic control. parole chiave: insediamenti antropici, progradazione della linea di costa, olocene, piana di sibari. keywords: human settlement, coastline progradation, holocene, sybaris plain. 63insediamenti umani in un paesaggio ... fig. 1 ubicazione dell’area e lineamenti morfologici della piana di sibari studied area location and geomorphic outlines of the sybaris plain. 64 logica e su quelli di alcuni sondaggi manuali effettuati nella piana, hanno consentito di meglio definirne i caratteri ambientali e dinamici. 2 evoluzione del paesaggio 2.1 il paesaggio neolitico (7000÷4800 bp fig. 2) il periodo si è sviluppato nell’ultima fase di risalita del livello marino e in quella d’avvio della quasi stabilità. l’inizio di questo periodo coincide pressappoco con la massima ingressione marina verificatasi in seguito alla risalita postglaciale del livello marino. il livello del mare era circa 20 metri più in basso dell’attuale (antonioli et al., 2004; pagliarulo, 2006) e la riva bordava il terrazzo di favella della corte su cui erano posti alcuni insediamenti. la scarpata del terrazzo rivolta verso mare, ben più pronunciata in altezza rispetto all’attuale, costituiva una ripa al piede della quale si stendeva una spiaggia. i resti dei cordoni litoranei limitrofi alla ripa possono essere ascrivibili a questo periodo o a un periodo immediatamente successivo (fig. 3). il f. crati scorreva a ridosso della scarpata settentrionale del terrazzo e sfociava probabilmente circa 2 km più ad est di favella della corte. in questa zona l’apporto del f. crati induceva una certa progradazione della linea di riva. diversamente, più a nord, il f.coscile, che sfociava nella zona più interna dell’insenatura, non apportava sufficiente sedimento per indurre lo stesso ritmo di progradazione e, conseguentemente, l’area era caratterizzata dalla presenza di ampie aree palustri. la zona più settentrionale del golfo era caratterizzata dall’ampio deposito di delta-conoide del t. raganello, i cui depositi ammantavano il terrazzo sottostante addolcendone la pendenza. in base all’età calibrate misurate nella piana di sibari (pagliarulo, 2006) i sedimenti di questo periodo giacciono oggi localmente anche oltre i 30 metri di profondità. 2.2 il paesaggio al tempo di sybaris (2.700÷2.500 bp fig. 2) nell’intervallo di tempo che separa questo periodo dal precedente, il livello del mare salì nell’area fino a circa -2/-3 m rispetto all’attuale e il paesaggio neolitico alla base dei terrazzi venne sepolto sotto vari metri di sedimento. lo stacco morfologico tra i terrazzi e l’ambiente sottostante si ridusse sensibilmente e il paesaggio mutò in modo evidente. la foce del f. crati migrò verso nord di circa 3 km e progradò oltre 2 km; ancora visibili da foto aeree sono le evidenze di tale avanzamento, testimoniato da tracce di paleoalvei fra torre del ferro e masseria capo crati (fig. 3). alcuni paleoalvei, cui si fa riferimento, coincidono con quelli riportati da guerricchio & ronconi, (1997), altri sono stati individuati attraverso la recente fotointerpretazione e il rilievo di terreno. al tempo di sybaris il tratto finale del f. crati scorreva in prossimità del bordo meridionale di un bacino costiero (già indicato in guerricchio & ronconi, 1997) più orientale rispetto alle aree palustri neolitiche ormai sepolte. occasionalmente il fiume sfociava (probabilmente con canali secondari ed effimeri) direttamente nella laguna (fig. 3). in questo periodo a clima fresco e soprattutto umido (lamb, 1982; shackleton, 1988), definito “piccola età glaciale arcaica” (ortolani & pagliuca, 2007), il f. crati doveva aver esondato ripetutamente e consistentemente soprattutto verso nord dove era presente l’area topograficamente più depressa probabilmente mantenuta tale dalla locale subsidenza. il paesaggio di questo periodo è attualmente sepolto ad alcuni metri di profondità tanto che i piani di calpestio di sybaris sono stati rinvenuti fino a circa 8 metri sotto l’attuale piano di campagna (guerricchio & melidoro, 1975; cotecchia et al., 1994; cherubini et al., 1994; pagliarulo, 2006). la calibrazione di una datazione riportata in guerricchio & melidoro (1975) consente di attribuire alla prima fase di questo periodo un frammento di carbone rinvenuto nello scavo di stombi a 1.35 m dall’attuale livello marino. 2.3 il paesaggio greco-romano (2.400÷1.400 bp fig. 2) tra il 2400 e il 1400 bp il paesaggio si evolve ulteriormente. il corso del crati si allontana dal bordo della laguna posizionandosi leggermente più a sud e la foce prograda lentamente fino ad avanzare di circa un chilometro. la maggiore aridità climatica del periodo caldoarido tardo romano (1800÷1600 bp caliro et al., 1997), costituì probabilmente una concausa nel rallentamento della progradazione. l’interpretazione fotogeologica e il rilievo di campagna mostra che i beach ridges, il cui accrescimento era favorito da processi di deposito eolico in particolare nelle fasi aride, si sviluppavano soprattutto a sud della foce e risultavano tra loro più ravvicinati rispetto a quelli sviluppatisi precedentemente ad indicare avanzamenti limitati tra le fasi di stazionamento della linea di riva. non mancarono tuttavia ripetute esondazioni alle quali può essere attribuito lo spessore di sedimento tra la strada di thurii e il pavimento mosaicato di copia nel parco del cavallo. in questo affioramento (fig. 4) la presenza di superfici erosive, la dimensione dei clasti, l’assenza di strutture lasciano intuire condizioni di regime di flusso superiore legati ad eventi intensi forse correlabili a processi di crevasse più che di tracimazione. sul finire del periodo (1600÷1400 bp) il clima si deteriorò rapidamente (lamb, 1982; ortolani & pagliuca, 2007) favorendo l’instabilità idrologica dell’area e il colmamento del bacino lagunare. i sedimenti di tale periodo giacciono pochi decimetri sopra e sotto il livello marino attuale (guerricchio & melidoro, 1975; pagliarulo, 2006). 2.4 il paesaggio dal medioevo ad oggi (fig. 2) la locale subsidenza unitamente al peggioramento climatico alto-medioevale (oscillazione in senso fresco-umido) e soprattutto quello legato alla piccola età glaciale favorirono il seppellimento del paesaggio tardo-romano. gran parte della città di copia venne parzialmente sommersa dalle acque. in questa sorta di acquitrino si accumularono limi più o meno sabbiosi, nerastri alla base ben visibili lungo la strada principale di copia. in questi sedimenti era nota la presenza di un contenuto faunistico scarso con presenza di bivalvi (in particolare cerastoderma) e gasteropodi (in particolare helix). le nuove analisi effettuate hanno mostrato inoltre la presenza di rari ostracodi (cyprideis torosa jones e herpetocypris chevreuxi sars), che identificano acque dulcicolo-salmastre, e frammenti di ossa di canidi. tali sedimenti contengono inoltre frammenti di ceramica e laterizi probabilmente trasportati negli eventi alluvionali. p. bellotti et al. 65 fi g. 2 r ic os tr uz io ne s ch em at ic a d ei p ae sa gg i s uc ce d ut is i d al n eo lit ic o s ch em at ic r ec on st ru ct io n of t he d iff er en t la nd sc ap es fo llo w ed s ta rt in g fr om t he n eo lit hi c. insediamenti umani in un paesaggio ... 66 questa situazione permase per parte del medioevo (la calibrazione dell’età di un cerastoderma lamarki, riportata in guerricchio & melidoro (1975), data i sedimenti ad un intervallo compreso circa tra il 950 e il 1150 bp). il nuovo rilievo di terreno ha permesso di osservare come i sedimenti passino verso l’alto a limi e limi sabbiosi giallastri sterili, talvolta con laminazione da ripple e locali, nonché dimensionalmente limitati, fenomeni di canalizzazione. tali sedimenti possono ascriversi ai ripetuti eventi alluvionali, con prevalenza dei fenomeni di tracimazione, che si verificarono nel tardo medioevo e durante la piccola età glaciale. nell’area di casabianca, ai depositi alluvionali, si intercalano diversi letti centimetrici di sabbie fini ben classate, di probabile origine eolica, (fig. 5). fenomeni di avulsione nei tratti terminali dei fiumi crati e coscile causarono ripetute confluenze e separazioni dei due fiumi testimoniando l’intenso disordine idrico che afflisse l’area per lungo tempo. piccoli ed effimeri stagni interdunari, testimoniati da alcuni livelli di peliti organiche reperiti in alcuni sondaggi manuali, si formarono in prossimità della riva man mano che questa progradava. l’opera di sistemazione idraulica iniziò nel 1882, ma è solo nel 1930 che si cominciò l’arginatura dei tratti terminali del crati e del coscile. nella bonifica dell’area si attuò un collettore di drenaggio (gli stombi) che ricalca il paleoalveo del coscile stesso e, recentemente in sinistra del crati, una piccola laguna è stata sistemata a piccolo porto turistico. 3 gli insediamenti umani le prime forme di popolamento stabile nei pressi della piana di sibari risalgono al neolitico antico. per quanto riguarda le epoche precedenti si possono trovare tracce di frequentazione nelle aree più interne, ad esempio nei pressi di castrovillari, ma le zone più fig. 3 stralcio di un’immagine del “volo italia 1989÷90” in cui sono indicate le posizioni di un beach ridge presumibilmente neolitico e di paleoalvei del f. crati del periodo greco-romano. part of an aerial photograph (“volo italia 1989-90”), on which positions of a probably neolithic beach ridge and the greek-roman paaleobeds of the crati river are indicated. fig. 4 sedimenti alluvionali che ricoprono i resti di una strada (probabilmente di thurii) sui quali è poggiato un pavimento con mosaico di una casa di copia. i tratti bianchi individuano superfici erosive che, unitamente alla taglia massima dei clasti e all’aspetto massivo del deposito, indicano una successione di eventi piuttosto intensi. alluvial sediment covering the remains of a street (probably thurii) and on which rests a floor with a mosaic belonging to a house of copia. dashes mark erosion surfaces, which – together with the clast size and the massive structure – evidence a series of rather heavy floods., p. bellotti et al. prossime alla piana del crati non hanno fornito testimonianze. con il passaggio al neolitico la situazione subisce un cambiamento significativo, testimoniato dalla comparsa di un sito di rilevante importanza individuato nei pressi della località “favella della corte” (tiné, 1992). si tratta di un villaggio di notevoli dimensioni, frequentato dal neolitico antico al neolitico recente, con una cesura nel neolitico medio caratterizzata da una fase di abbandono. e’ proprio in questo frangente che cominciano invece le frequentazioni in grotte poste nelle aree collinari più interne – pavollella (carancini & guerzoni, 1987) e s. angelo (tiné, 1987) mentre solo la grotta di san michele di saracena ha un’occupazione che inizia dalla fase finale del neolitico antico (tinè & natali, 2004) e questo spinge a ipotizzare che i due eventi siano da mettere in qualche modo in relazione reciproca. una possibile causa, anche se non ci sono ancora prove concrete a supporto di tale ipotesi, potrebbe essere un dissesto idrogeologico della piana con conseguenze sulle attività del villaggio ma senza interessare direttamente il sito, dove non è attestato alcun livello alluvionale tra le due fasi insediative. (tiné & traverso, 1996a; tiné & traverso, 1996b; tiné, tiné & traverso, 2003). a differenza del tavoliere delle puglie, con un insediamento basato su piccoli nuclei distribuiti nel territorio, nella piana di sibari sembra che il popolamento fosse concentrato nel villaggio, e questo spiegherebbe sia le sue dimensioni, sia l’assenza di altri siti nel comprensorio circostante. favella della corte si trovava su un terrazzo ai limiti dell’attuale pianura, posto nelle vicinanze di un vecchio alveo del crati e dell’antica linea di costa, al sicuro da rischi alluvionali ma abbastanza vicino da sfruttare dal punto di vista economico anche gli ambienti lagunari nelle vicinanze la posizione occupata aveva inoltre rilevanza strategica in quanto si trovava lungo le direttrici di traffico dell’ossidiana e dava al villaggio una importante funzione di snodo tra la zona apulo lucana e quella calabrese. dalla fine del neolitico fino all’arrivo dei coloni greci non sono più attestati insediamenti nelle aree prossime alla piana di foce del crati. il villaggio di favella viene abbandonato e le uniche testimonianze continuano a provenire dalle grotte, seppure con una connotazione cultuale piuttosto che abitativa. dal bronzo medio è nuovamente testimoniato per la sibaritide un popolamento ricco e dinamico, ma tutti i siti censiti in anni di ricognizione sono collocati nella fascia collinare o pedemontana, dunque a una relativa distanza dalla costa (peroni & trucco, 1994; vanzetti, 2000). difficile descrivere il rapporto esistente tra l’uomo e la pianura in questa fase, e in attesa di ulteriori studi e approfondimenti si possono formulare soltanto alcune ipotesi. il forte alluvionamento e il disordine idrico cui è stata soggetta la piana nel corso dei secoli rende praticamente impossibile il rinvenimento di evidenze archeologiche in queste aree, dato che il suolo antico si trova sepolto sotto diversi metri di strati alluvionali. nonostante ciò ci sono alcuni elementi che possono aiutare a formulare qualche ipotesi relativa alla distribuzione del popolamento. il confronto con altre aree calabresi ha mostrato come, anche in contesti geologicamente più favorevoli ad attività di ricognizione, si confermi un insediamento preferenziale in zone collinari rispetto a quelle pianeggianti (peroni, 1986). anche recenti campagne di survey condotte nei pressi di francavilla marittima, in prossimità del conoide del t. raganello, che include una fascia di transizione tra l’alta pianura e le fascia pedecollinare, hanno mostrato la presenza di materiale protostorico soltanto a quote elevate (attema & van leusen, 2003). questo quadro trova conferma in un passo di dionigi di alicarnasso (dionys i, 11, 2-4; 12, 1) che, descrivendo la popolazione stanziata nella sibaritide in questa fase storica (enotri), parla di una serie di villaggi o piccole città collocate presso i monti, senza fare cenno ad insediamenti distribuiti nelle aree pianeggianti. l’economia locale, inoltre, si basava su agricoltura a secco, arboricoltura e allevamento e grande importanza aveva anche la pastorizia, attività legata più ai territori dell’entroterra che alla piana umida e paludosa. sebbene le nostre conoscenze possano essere state condizionate da ricerche focalizzate soprattutto sull’area collinare e possano dunque essere soggette in futuro a revisione in seguito ad ulteriori approfondimenti (attema & van leusen, 2003), il quadro che ne emerge è di una popolazione poco interessata alle risorse offerte dalla piana, mancando le condizioni per controllarne il disordine idrico e per sfruttarne i terreni dal punto di vista agricolo. nonostante ciò la disposizione dei siti sui terrazzi limitrofi garantiva un 67 fig 5 sedimenti alluvionali che ricoprono i resti romani nel sito di casa bianca. le sabbie intercalate ai limi presentano frequentemente un ottimo classamento e un’asimmetria positiva e possono essere attribuite al trasporto eolico dalla vicina spiaggia. alluvial sediment covering the roman remains at casa bianca. sands interbedded to silt often show very good sorting and a positive skewness, and may be ascribed to aeolian action on the sands belonging to the neighbouring beach. insediamenti umani in un paesaggio ... controllo dalla distanza della pianura e della costa. il fiume e le lagune presenti potevano invece svolgere un ruolo importante come approdo per i navigatori micenei e successivamente greci, lasciando memoria di un luogo molto appetibile dal punto di vista agricolo, strategico e commerciale per la colonizzazione successiva. anche se queste scelte insediative possono essere condizionate dalla difficoltà di occupare e sfruttare stabilmente la pianura a causa delle complesse condizioni ambientali, resta comunque forte l’impressione che la scelta delle nuove unità geomorfologiche (terrazzi di dimensione variabile ma mai eccessive, ben difendibili e delimitati da corsi d’acqua) sia dettata dalle caratteristiche etniche, economiche e strategiche degli enotri. verso la fine dell’viii secolo a.c. (circa 2700 bp) si assiste ad una svolta radicale che determina una cesura rispetto alla situazione precedente. l’arrivo di coloni achei e la fondazione di una città nel cuore della pianura segna l’avvio di una nuova fase dal punto di vista storico e culturale e più in particolare nella gestione del territorio. per la prima volta la zona pianeggiante viene vista come una risorsa e diventa oggetto di una serie di attenzioni e lavori tesi a permetterne lo sfruttamento produttivo. la città di sybaris fu fondata nel 720 a.c. lungo il litorale tra i fiumi crati e coscile (allora noto come sybaris), nei pressi di una laguna che poteva avere funzione portuale. gli scavi archeologici hanno consentito di conoscere qualcosa della città arcaica e ci mostrano un centro dalla forma allungata che si disponeva parallelamente alla linea di costa e occupava una antica duna costiera. in questo modo si trovava su un alto morfologico che garantiva alla polis, insieme a tutta una serie di opere di arginamento e bonifica realizzate nel resto della pianura, una condizione di relativa sicurezza da eventuali rischi di carattere idrico. la posizione risultava fondamentale dal punto di vista strategico e commerciale, in quanto poneva la metropoli achea al centro del sistema politico da lei creato, e al tempo stesso la metteva in contatto con il mare e con le aree dell’interno grazie alla vicinanza dei due fiumi crati e coscile, le cui valli sono sempre state le principali direttrici di comunicazione verso l’entroterra calabrese. pochissimi sono i rinvenimenti archeologici che consentono di conoscere qualcosa sul popolamento in età arcaica e sulle modalità di sfruttamento del territorio. per quanto riguarda le aree collinari è documentata la presenza di almeno due villaggi e di diverse aree di culto, mentre per la pianura non ci sono tracce né di insediamenti né degli interventi diretti sul territorio di cui si è parlato precedentemente, ma che hanno echi nella tradizione letteraria (ath. xii, 519 f). possiamo ipotizzare dunque un popolamento concentrato nell’area urbana e nei villaggi, mentre le aree sacre svolgevano un ruolo di delimitazione territoriale, di punto di riferimento per i cittadini delle aree periferiche e di mediazione tra mondo greco e indigeno. il sistema politico e territoriale appena delineato giunse a termine con la fine del vi secolo a.c. (circa 2500 bp). nel 510 a.c. una guerra contro crotone vide sibari perdente e, secondo gli storici antichi, i crotoniati deviarono sulla città il corso del fiume crati distruggendola definitivamente (strab. vi, 1, 13). dal punto di vista storico è molto probabile che il conflitto abbia creato dei danni seri, anche intenzionali, al sistema di controllo delle acque organizzato dai sibariti favorendo successive divagazioni fluviali. la crisi del popolamento seguita al collasso del sistema politico sibarita, avvenuta in un momento in cui sarebbero stati necessari maggiori sforzi per controllare i corsi d’acqua a causa del peggioramento delle condizioni climatiche, favorì indubbiamente un periodo di disordine idrico nella piana. tutta la prima metà del v secolo è caratterizzata infatti da un popolamento instabile e da un controllo antropico sulle infrastrutture reso carente da una condizione di conflittualità permanente data da vari tentativi fallimentari di rifondare sibari cui facevano seguito reazioni militari di crotone (guzzo, 1976; osanna, 1992). tutta questa situazione favorì divagazioni del crati verso la zona più depressa posta a nord arrivando dunque a ricoprire il sito di sibari (una prova ne è lo strato alluvionale che copre i livelli arcaici) ormai abbandonato e generando la tradizione di una deviazione da parte dei crotoniati (her. v, 45 parla di un ramo secco del crati: non si sa la datazione ma, a livello di ipotesi, potrebbe trattarsi o del corso del fiume precedente alle esondazioni appena citate, o di un alveo lasciato da una di queste esondazioni prima che il fiume si stabilizzasse nuovamente più a sud). la seconda metà del v secolo testimonia un’altra svolta nella storia della piana del crati. gli esuli sibariti chiedono aiuto ad atene per edificare nuovamente la loro città e, nel 444÷3 a.c., viene fondata la colonia panellenica di thurii. la nuova polis si trovava sempre tra coscile e crati, che scorreva ancora a sud della posizione attuale, e l’area urbana era in parziale sovrapposizione alla precedente sybaris (guzzo, 1992; osanna, 1992). che il centro precedente fosse ancora noto è testimoniato sia dalla parziale continuità topografica del sito sia dal riutilizzo di materiale arcaico nelle costruzioni successive, ma il fatto che l’impianto urbanistico sorga ex novo senza apparenti condizionamenti, è una prova che l’area doveva risultare libera. lo strato alluvionale che ricopre i livelli arcaici indica che nel periodo compreso tra la fine del vi e la metà del v secolo a.c. l’area fu soggetta a fenomeni di esondazione fluviale. il fatto che il sito sia stato ugualmente scelto per edificare la nuova città indica che la zona era di nuovo ritenuta idonea per ospitare un importante centro senza rischi di ulteriori danni da parte dei due corsi d’acqua adiacenti. la piccola età glaciale arcaica era ancora in atto e questo poteva comportare altri fenomeni alluvionali di rilievo. nonostante ciò l’intervento ateniese, essendo organizzato e supportato da una grande potenza politica, rese possibili nuovi interventi di bonifica e arginamento dei fiumi tali per cui la posizione anticamente occupata da sybaris potesse essere considerata sicura. la fondazione della nuova città insieme ai lavori infrastrutturali che questo comportava favorì una nuova distribuzione delle terre e la comparsa di una forma di popolamento basata su piccole fattorie sparse sul territorio, documentate ampiamente a partire dalla fine del v inizi iv a.c. nelle aree collinari, ma questa volta testimoniate archeologicamente anche per l’area pianeggiante (cantiere settentrionale, detto stombi greco, 2003). la tensione crescente con le popolazioni italiche nel corso del iv÷iii secolo a.c. creò problemi ai nuovi coloni soprattutto nelle aree di frontiera, ma fu la seconda guerra punica che lasciò un segno indelebile nella vita della sibaritide, così come di tutto il sud italia. 68 p. bellotti et al. presto roma intervenne per contrastare le difficoltà della regione e per estendere il proprio controllo politico. tra le attività intraprese si deve annoverare la deduzione di una colonia di diritto latino tra il 194 e il 192 a.c. a thurii, che prese ora il nome di copia (guzzo, 1992). per l’occasione furono inviati 3300 coloni (liv. xxxv, 9), numero ritenuto esiguo rispetto alle necessità (strab. vi,, 1, 13; liv. xxxv, 9) dell’area e alla quantità di terre disponibili che ammontavano a un totale di 270 km2. queste considerazioni sono un segnale delle difficoltà in cui versava la piana di sibari all’inizio del ii secolo a.c., e una conferma si trova anche nell’analisi del centro cittadino. l’estensione della nuova colonia infatti vide la sua superficie ridotta di oltre la metà rispetto alla metropoli ellenistica. l’intervento romano dovette permettere alla città di riprendersi in parte dalle difficoltà: nelle aree collinari abbondano tracce di ville e aree fittili e in città furono intrapresi notevoli interventi di carattere architettonico, che trasformarono le aree pubbliche con l’edificazione di una piazza, di terme, di un teatro, delle mura (guzzo, 1992; paoletti, 1994). tutte queste operazioni sono limitate però alla fine del i a.c. e all’inizio del secolo successivo, e già dal ii d.c. cessano grandi interventi e un’area prima a destinazione pubblica come l’area basolata antistante la porta marina viene devoluta a necropoli già alla fine del i d.c. dione crisostomo (d. chr., primo tarsico, 25) parla delle città del sud come centri in decadenza, e anche se la prosperità delle ville nel territorio circostante proseguirà fino alla fine del ii d.c., la situazione del centro urbano e forse anche della pianura limitrofa versava già in una condizione più difficile. con il iii secolo d.c. (circa 1700 bp) il sistema della villa subisce una forte ristrutturazione e pochissimi centri sopravvivono alla crisi generale che colpisce il mondo romano (guzzo, 1986; accardo, 2000; sangineto 2001). anche la città andava perdendo gradualmente importanza. nel v secolo d.c. ad esempio alcuni quartieri risultano già abbandonati, anche se l’area delle terme venne riutilizzata ancora successivamente per ricavarne luoghi di culto cristiani. altro elemento di declino può essere individuato nello spostamento del porto nei pressi di rossano, dove è attestato nel vi secolo d.c. (procop. vii, 27). questo fatto, conseguente alla crisi dell’abitato, è anche causato dal graduale riempimento cui era soggetta la laguna, dovuto sia ai continui apporti di sedimenti fluviali sia all’incapacità degli abitanti di far fronte al graduale deterioramento ambientale e idraulico della piana. l’ultima testimonianza diretta di thurii-copia ci viene da procopio che nomina la città nei racconti sulle vicende della guerra gotica. in seguito della città si perdono completamente le tracce. ormai il popolamento era concentrato nelle zone dell’interno presso luoghi naturalmente fortificati o ville di potenti signori che garantivano una certa protezione, tornando a insediare quelle unità geomorfologiche tipiche dell’età protostorica e preferite dalle popolazioni italiche di iv÷iii a.c. dopo la metà del vi secolo, quando il nuovo peggioramento delle condizioni climatiche con l’aumento delle precipitazioni rendeva necessario un impiego maggiore di risorse per controllare i corsi d’acqua, il centro cittadino venne abbandonato con gradualità. in seguito a questo evento anche la piana, con le opere idrauliche necessarie al suo sfruttamento e al controllo fluviale, fu completamente trascurata (noyé, 2001). fino almeno al xii secolo ci furono comunque frequentazioni a carattere agricolo (anche se probabilmente senza forme di popolamento stabile), ma successivamente l’impaludamento divenne inevitabile e ancora nel xix secolo la piana di sibari è ricordata come terra malarica e soggetta a un totale disordine idrico. soltanto negli anni ’30 del xx secolo ricomincerà un’opera di bonifica che porterà nei 20 anni successivi al recupero totale della pianura per scopi abitativi e produttivi. 4 considerazioni finali l’area prossima alla foce del f. crati, in particolare l’ala settentrionale del delta, è stata caratterizzata nell’olocene da una intensa dinamica morfologica ed ha rappresentato, fin dal neolitico, una regione di forte attrazione per gli insediamenti umani. il forte richiamo derivava in gran parte dall’essere ubicata in posizione strategica per i commerci via mare con il mediterraneo orientale. l’area risultava favorevole anche ai traffici con il mediterraneo occidentale raggiungibile, via terra, attraverso le valli dei fiumi crati e coscile, e le corrispondenti valli tirreniche dei fiumi savuto e lao evitando, così, la circumnavigazione della calabria e il passaggio nel difficile stretto di messina. la presenza di deboli alture pianeggianti, costeggiate dai fiumi e prossime al mare, favorì fin dal neolitico i tentativi di insediamento nell’area. questa, peraltro, caratterizzata da un’articolata insenatura, con la presenza di foci fluviali e di bacini paralici, risultava in passato particolarmente favorevole all’approdo. la nascita di sibari nel favorevole contesto paesaggistico del i millennio a.c. fu quasi un evento inevitabile, considerate le opportunità di ricchezza e sviluppo offerte dalla posizione limitrofa alla foce dei fiumi crati e coscile. la città, sorta su un cordone dunare e protetta da una serie di opere idrauliche, si sviluppò rapidamente, ma c’erano in agguato l’avidità dei vicini e l’instabilità del territorio. il controllo dell’idrografia richiedeva impegno e attenzione costanti, cosa non facile in caso di conflittualità. la guerra con crotone ebbe ripercussioni inevitabili sul controllo dell’instabilità idrografica dell’area tanto che i successivi tentativi di reinsediamento, organizzati dai sibariti, fallirono. in un contesto climatico sfavorevole (piccola età glaciale arcaica), solo un intervento organizzato, come quello ateniese, permise la fondazione di thurii con un nuovo insediamento stabile. la stabilizzazione di thurii, e successivamente lo sviluppo della colonia romana di copia, avvenne in un periodo climaticamente favorevole (caldo romano protrattosi fino al ii secolo d.c.). la crisi del mondo romano del iii secolo d.c. si verificò durante la transizione alla piccola età glaciale altomedievale. così, proprio quando diveniva necessaria una cura maggiore del territorio, vennero meno l’autorità e le risorse umane ed economiche necessarie ad organizzarla. gli insediamenti deperirono e, tra la fine del potere romano e l’acme della piccola età glaciale altomedievale la città venne abbandonata. nel periodo caldo medievale non si ripristinarono insediamenti stabili ma solo attività agricole. successivamente, nell’area già afflitta da una significativa subsidenza, gli eventi sedimentari relativi al periodo fresco-umido della piccola età glaciale seppellìrono definitivamente i resti 69insediamenti umani in un paesaggio ... della città greco-romana trasformando l’area in un invivibile acquitrino. la rinascita dell’area si verifica negli ultimi cento anni solo in concomitanza con lo straordinario sviluppo tecnico che ha reso l’uomo un vero e proprio agente morfogenetico, in grado esso stesso di modificare il paesaggio in qualunque contesto climatico. un ambiente molto dinamico come questa piana costiera, dove subsidenza e differenti fasi climatiche hanno concorso nel periodo storico alla mutevolezza del paesaggio, risulta abitabile e controllabile dall’uomo in epoche di relativa stabilità dal punto di vista politico ed economico e quando è presente un potere centrale in grado di coordinare gli sforzi in vista della realizzazione e della successiva manutenzione di infrastrutture idrauliche. ogni volta che le condizioni ambientali diventano difficili, deve corrispondere uno sforzo maggiore da parte delle popolazioni locali per mantenere il controllo del territorio o ripristinarlo dopo un evento particolarmente violento. questo riuscì la prima volta grazie all’intervento ateniese, ma non riuscì invece nel periodo tardoantico, condannando la piana del crati a un inevitabile declino. dalla storia della sibaritide appare, dunque, evidente come lo sviluppo degli insediamenti umani sia stato in passato tanto legato alla stabilità della struttura sociale, quanto a quella ambientale. lavoro svolto con il contributo fondi ateneo “sapienza” università di roma 2004 responsabile piero bellotti bibliografia accardo s. (2000) villae romanae nell’ager bruttius, roma. attema p.a.j. & van leusen p.m. (2003) regional archaeological patterns in the sibaritide: preliminary results of the rpc field survey campaign 2000, palaeohistoria 43/44 (2001/2002), pp. 397416. antonioli f., lambek k., amorosi a., belluomini g., correggiari a., devoti s., depuro s., monaco c., marocco r., pagliarulo s., orru p. & silenzi s. (2004) sea level at 8 and 22 ka cal. bp along the italian coastline. in antonioli f. & vai g.b. (eds), “climax maps italy explanatory notes”, bologna, pp. 11-14 bellotti p., caputo c., davoli l., evangelista s.& pugliese f. (2003) sedimentological and morphological evolution of the crati river delta (calabria italy). suppl. geogr. fis. e din. quarter., 6, pp. 25-32. caliro s., francese g., galatei c., galatei g., imperato m., milia a., monetti v., nardi g., ortolani f., pagliuca s., stanzione d. & toccaceli r.m. (1997) geologia delle grandi aree urbane: relazioni sul lavoro svolto ed i primi risultati ottenuti dalle unità operative.l’area urbana di napoli: principali caratteristiche geologiche stratigrafiche ed ambientali. cnr-regione emilia. carancini g.l. & guerzoni r.p. (1987) gl i scavi nella grotta pavolella presso cassano allo jonio atti iipp, 26, pp. 183-792. cherubini c., cotecchia v. & pagliarulo r. (1994) geological and geotechnical problems connected with the disappearance of the ancient city of sybaris, science and technology for cultural heritage, 3, pp. 95-112. cherubini c., cotecchia v. & pagliarulo r. (2000) subsidence in the sybaris plain (italy), in land subsidence. proceedings of the sixth international symposium on land subsidence (ravenna, italy), 1, pp. 3-15. cherubini c., cotecchia v. & pagliarulo r. (2005) review on land subsidence in the archaeological site of sybaris (southern italy). giornale di geologia applicata, 1, pp. 13 –21. cinti f.r., moro m., pantosti d., cucci l. & d’addezio g. (2002) new constraints on the seismic history of the castrovil lari fault in the poll ino gap (calabria, southern italy). journal of seismology, 6, pp.199–217. cotecchia v., cherubini c. & pagliarulo r. (1994) geotechnical characteristic of outcropping deposits in the sibari plain. proceendings xiii international conference of soil mechanics and foundation engineering, 1, new delhi, pp. 245250. cucci l. & cinti f. r. (1998) regional uplift and local tectonic deformation recerded by the quaternary marine terraces on the ionian coast of northern calabria (southern italy). tectonophysics, 292, pp. 67-83. greco e. (2003) tra sibari, thurii e copiae. qualche ipotesi di lavoro, in archeologia del mediterraneo. studi in onore di ernesto de miro, a cura di g. fiorentini, e. de miro, m. caccamo caltabiano, a. calderone, roma, pp. 369-374. guerricchio a. & melidoro g. (1975) ricerche di geologia applicata all’archeologia della città di sibari sepolta. geologia applicata e idrogeologia, 10, pp. 107-127. guerricchio a. & ronconi m.l. (1997) osservazioni geomorfologiche nella piana di sibari e variazioni delle linee di costa storiche nella zona degli scavi archeologici. i quaderni irfea, 12, pp. 1-31. guzzo p. g. (1976) tra sibari e thurii, "klearchos", 18, pp. 27-64 guzzo p. g. (1986) il territorio dei bruttii dopo il ii sec. d.c., in calabria bizantina. istituzioni civili e topografia storica, roma, pp. 109-120. guzzo p. g. (1992) sibari, materiali per un bilancio archeologico, in sibari e la sibaritide, atti xxxii convegno studi sulla magna grecia, taranto, pp. 51-82. lamb h. h. (1982) climate history and modern world. london methuen, 19, pp. 387. lambeck k., antonioli f., purcell a. & silenzi s. (2004) sea-level change along the italian coast for the past 10,000 yr. quaternary science reviews, 23, pp. 567–598. marabini f. (2007) variazioni climatiche ed evoluzione costiera. in: clima e cambiamenti climatici. le attività di ricerca del cnr, pp. 165-168. noyé g. (2001) economia e società nella calabria bizantina (iv-xi secolo), in storia della calabria medievale, a cura di a. placanica, roma, pp. 577656. osanna m. (1992) chorai coloniali da taranto a locri, 70 p. bellotti et al. roma. ortolani f. & pagliuca s. (2007) evidenze geologiche di variazioni climatico-ambientali storiche nell’area mediterranea. quaderni della sgi, 1, pp. 13-18. pagliarulo r. (2006) coastal change and the environmental evolution of the archeological site of sybaris (southern italy). geog. fis. din. quat., 26, pp. 51-59. pagliarulo r. (2007) le variazioni eustatiche e le influenze climatiche sull’evoluzione della piana di sibari. in: clima e cambiamenti climatici. le attività di ricerca del cnr, pp. 165-168. paoletti m. (1994) occupazione romana e storia delle città. in: storia della calabria antica, 2, a cura di s. settis, reggio calabria, pp. 467-538. peroni r. & di gennaro f. (1986) aspetti regionali dello sviluppo dell’insediamento protostorico nell’italia centro-meridionale alla luce dei dati archeologici e ambientali, "dda", 4, pp. 193-200. peroni r. & trucco f. (1994) enotri e micenei nella sibaritide, taranto. russo, f. & schiattarella, m. (1992) osservazioni preliminari sull’evoluzione morfostrutturale del bacino di castrovillari (calabria settentrionale). studi geologici camerti, vol. spec. 1992/1, pp. 271278. sangineto a. b. (2001) trasformazioni o crisi nei bruttii fra il ii a.c. ed il vii d.c.. in: modalità insediative e strutture agrarie nell’italia meridionale in età romana, a cura di e. lo cascio, a. storchi marino, bari, pp. 203-246. schiattarella m. (1996) tettonica della catena del pollino (confine calabro-lucano). mem. soc. geol. it., 51, 543-566. shackleton n.j. (1988) oxigen isotopes, ice volume and sea level. quat. sci. rev., 6, pp. 183-190 tiné s. (1987) il neolitico, in storia della calabria antica, 1, a cura di s. settis, reggio calabria, pp. 39-63. tiné s. (1992) il villaggio di favella della corte e la neolitizzazione della sibaritide. in: sibari e la sibaritide, atti xxxii convegno studi sulla magna grecia, taranto, pp. 85-102. tiné v. & traveso a. (1996a) sibaritide: insediamento, in forme e tempi della neolitizzazione in italia meridionale e in sicilia, a cura di v. tiné, soveria mannelli, pp. 182-184. tiné v. & traverso a. (1996b) favella: paesaggio, in forme e tempi della neolitizzazione in italia meridionale e in sicilia, a cura di v. tiné, soveria mannelli, pp. 569-571. tiné s., tiné v. & traverso a. (2003) la piana del crati nelle preistoria: ambiente, risorse, insediamento, in variazioni climatico-ambientali e impatto sull'uomo nell'area circum-mediterranea durante l'olocene, a cura di c. a. livadie e f. ortolani, bari, pp. 407-418. tiné v. & natali e. (2004) la grotta di san michele in saracena (cs): una sequenza stratigrafica dal neolitico antico al bronzo medio, atti della 37 riun. scient. iipp, 2004, pp. 694-702. turco e., maresca r. & cappadona p. (1992) la tettonica plio-pleistocenica del confine calabro-lucano: modello cinematico. mem. soc. geol. it., 45, pp. 519-529. vanzetti a. (2000) costruzione e problemi dei "paesaggi di potere" nella sibaritide (calabria) dall’età del bronzo alla prima età del ferro, in paesaggi di potere, problemi, prospettive, a cura di g. camassa, a. de guio, f. veronese, roma, pp. 153-183. 71 ms. ricevuto il 29 febbraio 2008 testo definitivo ricevuto il 27 gennaio 2009 ms. received: february 29, 2008 final text received: january 27, 2009 insediamenti umani in un paesaggio ... << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /none /binding /left /calgrayprofile (dot gain 20%) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /error /compatibilitylevel 1.4 /compressobjects /tags /compresspages true /convertimagestoindexed true /passthroughjpegimages true /createjdffile false /createjobticket false /defaultrenderingintent /default /detectblends true /colorconversionstrategy /leavecolorunchanged 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(quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 217 219 volcano geology and mapping guido giordano dipartimento di scienze, sezione di geologia, università degli studi roma tre, rome, italy corresponding author: g. giordano <guido.giordano@uniroma3.it> abstract: recent development in mapping of italian volcanic areas, both ancient and active, within the framework of the carg project (italian geological map 1:50000 scale) has allowed to define a stratigraphic approach that allows to correctly show the basic lithostratigraphy and the main internal organization of the volcanic succession including the essential periods of quiescence. such innovative approach proves to be very effective for hazard studies, land-planning, management of the geo-cultural heritage. keywords: volcano stratigraphy, mapping, active volcanoes 1. introduction the complex internal architecture of volcanic successions, both at individual volcano scale and at volcanic province scale, is controlled by the interplay between the evolution over time of the volcanic activity, essentially related to the evolution and structure of the magmatic plumbing system, and both climatic and tectonic factors. volcanic edifices may be simple (monogenetic or associated with fixed and short-lived point sources) or very complex (e.g. stratovolcanoes or caldera complexes), where polygenetic activity spans over long time periods and feeding systems are both timeand space-variable. volcano-tectonic and gravitational collapses may not only substantially and instantaneously change the topography of volcanoes but also affect the feeding system by changing the lithostatic load. erosion and remobilization of volcanic material during inter-eruptive periods and longer quiescent periods build large volcaniclastic aprons that grade into other continental and marine sedimentary environments. fig. 1 example of correlation of unconformity bounded stratigraphic units (ubsu) and lithosomes in the context of the national cartography project (carg; sheets 374 roma, 387 albano laziale, 375 tivoli, 388 velletri). mailto:guido.giordano@uniroma3.it 2. methods in order to represent such complexity, within the framework of the italian geological map at the 1:50000 scale (carg project, ispra), the common lithostratigraphic approach to mapping of volcanic areas has been sided by other stratigraphic tools able to organize the stratigraphic successions based on the hierarchy of unconformities and on the morphology of the volcanic structures. formal units that can be used to this purpose are the unconformity bounded stratigraphic units (ubsu) and lithosomes. ubsu are able to represent objectively the extent and physical expression of unconformities, implicitly related to the extent and duration of the associated geological processes, e.g. an unconformity related to the change of global climate affecting the sea level versus a regional tectonic uplift versus a local caldera collapse (fig. 1). lithosomes represent individual edifices at various scales allowing to associate parts of the volcanic successions to specific sources and eruption styles. 4. results and discussion the experience of the last twenty years of mapping in volcanic areas of the italian volcanological community has established a sound approach for the representation of volcanic successions, which greatly enhances the role of geological maps as ground reference work for civil protection purposes in active areas and resource assessment in recent or extinct areas. at the same time, geological mapping of active volcanic areas is fundamental for hazard assessment. this is especially true at long-dormant volcano like vesuvius, ischia, campi flegrei, lipari, vulcano, pantelleria, colli albani, where most if not all of the objective data available rely on the rock-record. this makes it essential that geological mapping is made as quantitative as possible and that the relative data are stored in open-source databases. for example, outcrop and sample data on thickness, grain size, lithofacies, chemistry, mineralogy etc. would be of great use for extracting information necessary for modeling of several processes such as lava invasion and pyroclast dispersals in the atmosphere. in addition, 3d data should be made available, both as raw zdata and as thematic maps (fig. 2). in essence, while field-based studies are becoming less and less fashionable, the digital revolution opens up a significant opportunity where the quantitative reappraisal of fundamental mapping of volcanic units can and should become an essential tool for hazard studies. 218 giordano g. fig. 2 3d shaded relief, perspective reconstruction of the albano maar succession from surface and bore-hole data (from diano et al., 2010). the view is perspective and southeastward. green colours are the shaded relief (vertical exaggeration 3x, comprised between 100 m a.s.l. and 900 m a.s.l.). the brown-orange and red colours inside the continuous (certain) to dotted (extrapolated) line are thicknesses of the albano maar succession retrieved from outcrop and bore hole stratigraphies (vertical blue to pale blue lines). colli albani caldera albano maar extension of albano maar deposits colli albani ignimbrite plateau 219 acknowledgements this contribution briefly summarizes the work of and the discussion with many colleagues under the framework of the carg project. references branca s., coltelli m., groppelli g., lentini f. (2011) geological map of etna volcano, 1: 50,000 scale. italian journal of geosciences, 130(3), 265-291. de rita d., fabbri m., giordano g., rodani s., trigari a. (2000) l'utilizzo delle unità stratigrafiche a limiti inconformi in ambiente vulcanico e vulcanoclastico; proposta di una metodologia di terreno e di organizzazione informatica dei dati. bollettino della società geologica italiana, 119(3), 749-760. diano g., bonamico a. giordano g. (2010) threedimensional reconstruction of the main unconformities of the colli albani stratigraphy and deposit volume calculations. in: funiciello r. and giordano g. (eds) the colli albani volcano. special publication of iavcei, 3. the geological society, london, giordano g., mattei m., funiciello r. (2010) geological map of the colli albani volcano. insert of geol soc london, iavcei series 3. lucchi f. (2013) stratigraphic methodology for the geological mapping of volcanic areas: insights from the aeolian archipelago (southern italy). geological society, london, memoirs, 37(1), 37-53. salvador a. (ed.). (1994) international stratigraphic guide a guide to stratigraphic classification, terminology, and procedure, second edition. boulder, colorado, the international union of geological sciences and the geological society of america, p. 214. volcano geology and mapping ms. received: may 9, 2018 final text received: may 23, 2018 220 imp.06magaldi microstrutture della crosta calcarea laminare (orizzonte petrocalcico) di due paleosuoli pleistocenici nell’agro di cerignola (foggia) donatello magaldi1 & maria giammatteo2 1dipartimento di scienza del suolo e nutrizione della pianta, università di firenze, piazzale delle cascine, 50 144 firenze, donatello.magaldi@unifi.it 2centro di microscopia elettronica dell’università di l’aquila, monteluco di roio, 67040 l’aquila riassunto: d. magaldi & g. giammatteo, microstrutture della crosta calcarea laminare (orizzonte petrocalcico) di due paleosuoli pleistocenici nell’agro di cerignola (foggia). (it issn 0394-3356, 2008). l’orizzonte petrocalcico (crosta calcarea, caliche, calcrete )è un orizzonte calcico indurito di origine pedogenetica, particolarmente diffuso nelle zone aride e semiaride. questa ricerca si è indirizzata alla descrizione dei livelli micro-laminari di crosta calcarea (laminar crust) osservati al microscopio elettronico a scansione (sem), provenienti da due suoli dell’agro di cerignola, in provincia di foggia e al loro significato paleoambientale. sono stati prelevati 8 frammenti della crosta calcarea laminare appartenente all’orizzonte petrocalcico di due paleo -suoli su depositi marini sabbiosi terrazzati del pleistocene inferiore. i due suoli appartengono a superfici poste a diversa altezza , rispettivamente a 100 m e a 80 m s.l.m. le osservazioni al sem evidenziano l’esistenza di due differenti microstrutture ( alfa e beta secondo wright) che indicano un processo di formazione dell’orizzonte petrocalcico in ambiente rispettivamente, “ inorganico” e “organico”. la prima prevale nel suolo situato a quota più elevata (qs), la seconda in quello situato più in basso (vm). queste strutture sono in ottimo accordo con un ambiente di clima mediterraneo e un parent material calcareo . i risultati, confrontati con la numerosa documentazione proveniente dalla letteratura internazionale, portano a concludere che il suolo a quota maggiore ha una crosta sub-superficiale prevalentemente di origine inorganica, dovuta a forte evapotraspirazione e alla circolazione di acque vadose in condizioni climatiche da aride a semiaride , mentre in quello a quota minore (vm), la crosta, sub-superficiale, appare più decisamente di origine biologica ( vegetazione presente sul suolo e microrganismi ), in condizioni climatiche variabili da semiaride a sub umide. queste condizioni diverse da quelle attuali, testimoniano che i due profili sono geneticamente differenti e forse di diversa età e sviluppo e al tempo stesso confermano ancora una volta il significato e l’importanza della crosta calcarea nelle ricostruzioni paleo climatiche del quaternario. abstract: d.magaldi & m. giammatteo, laminar crust microstructures of 2 pleistocene palaeosols with petrocalcic horizons from cerignola (foggia province, southern italy). (it issn 0394-3356, 2008). the petrocalcic horizon (caliche, calcareous crust) is a cemented or indurated calcic horizon largely occurring in arid, semiarid and mediterranean zones worldwide. palaeosols with petrocalcic horizons which formed on the early pleistocene marine sediments are common in the capitanata plain of the foggia province, southern italy. this paper reports results of sem –edx observation carried out on the laminar crust or platy horizon collected from two petrocalcic calcixerepts ( qs and vm) which formed on terraced sandy sediments in the countryside near cerignola ( capitanata plain ) at 100 and 80 m a.s.l. respectively. the soils differentiate for texture and profile development : being coarse and well developed qs, moderately fine and less developed, vm. results revealed in all samples the occurrence of features related to calcite micro features (the α and β fabric after wright) which are differently spread in the samples of each crust. qs crust posses features mainly related to a fabric ( inorganic origin) which is characterised by common crystallisation of large scalenohedral and rhombohedral calcite individuals, being scarce calcite features of biologic origin. on the contrary features as needle –shaped crystals, rice-grains crystals, tubules and rhizolites which are attributed to β fabric (biologic origin) are dominant in vm samples together with some silica substitution for calcium carbonate in organic structures. formation of these crust appears to be controlled by palaeoenvironmental factors. according to information coming from international references, it was assumed that inorganic process as evapotranspiration and vadose water movement mainly acted on the qs crust formation so producing the randomly arranged large crystals and the ca and mg enrichment during some arid or semiarid climatic conditions. instead the vm crust shows more expressed biologic features which are commonly related to be acquired in semi-arid to sub-humid climatic conditions by the action of both soil vegetation and micro-organisms. moreover, the occurrence of silica mobilisation and precipitation let us to assume that a strong soil ph variation during past time has happened. the two profiles were considered genetically different on the basis of microscopic features of the laminar crust .this fact also suggests that qs profile is older than vm and nearly confirms the significance of laminar crust in the quaternary palaeoclimatic reconstruction. parole chiave: crosta calcarea, orizzonte petrocalcico laminare ,microscopia elettronica a scansione, paleosuoli , pleistocene, significato paleoclimatico. key words: calcrete, laminar petrocalcic horizon, scanning electron microscopy, palaeosols pleistocene, palaeoclimatic significance. il quaternario italian journal of quaternary sciences 21(2), 2008 423-432 introduzione i suoli con orizzonte calcico e petrocalcico sono largamente diffusi nelle regioni a clima semiarido e mediterraneo;si stima che questi suoli coprano circa il 13% delle terre emerse (yaalon, 1988) l’orizzonte petrocalcico viene comunemente indicato con i termini generici di crosta calcarea, caliche, calcrete ecc. che indicano, non solo un orizzonte calcico indurito di origine pedogenetica ma anche accumuli carbonatici di origine sedimentaria,idrogeologica e diagenetica, che si localizzano tuttavia a profondità superiori a quelle della crosta pedogenetica e sono generalmente abbastanza distinguibili da quest’ultima. i petrocalcici sono di norma relativamente antichi e secondo la soil taxonomy (soil survey staff,1999 e 2006 ) gli orizzonti maggiormente induriti e più spessi non sarebbero posteriori al pleistocene superiore: orizzonti petrocalcici sono stati tuttavia individuati inoltre in sequenze sedimentarie molto antiche, a partire dal precambrico (chown & cady, 1983 citato da wright & tucker, 1991). da un punto di vista tecnico la crosta ha un comportamento antitetico.infatti se da una parte limita la 424 d. magaldi & m. giammatteo profondità di radicazione, la circolazione e a volte lo smaltimento delle acque vadose ed infine la lavorabilità meccanizzata del suolo, dall’altra può costituire una materia prima economica di facile reperibilità per piccole costruzioni e strade rurali, specialmente nei paesi in via di sviluppo (dincer et al., 2007; ifg, 2006). in puglia i suoli con crosta sono relativamente comuni specie nella capitanata e sui rilievi immediatamente circostanti dove, accanto a suoli di antica pedogenesi, si trovano suoli con crosta in formazione, processo favorito dalle attuali condizioni di piovosità pari a 500-600 mm annui compatibili con l’instaurarsi di questo processo (goudie, 1983; birkeland, 1984). alcune relazioni tra caratteristiche dei suoli con orizzonte calcico e petrocalcico dell’italia mediterranea e aspetti del paesaggio sono stati oggetto di una nota di alcuni anni fa (carnicelli et al.,1989). questo studio intende portare un contributo alla conoscenza delle microstruttura osservata al microscopio elettronico a scansione (sem) su livelli micro-laminari di crosta calcarea (laminar crust, platy horizon, croute zonaire (fr)) provenienti da due paleosuoli dell’agro di cerignola, in provincia di foggia e al suo significato paleoambientale (fig.1). materiali e metodi sono stati prelevati 8 frammenti della crosta calcarea laminare ( laminar crust) appartenente all’orizzonte petrocalcico di due petric calcisol (fao, 2006) o petrocalcic calcixerept (usda, 2006) sui depositi marini del pleistocene inferiore (sabbie straterellate giallastre pulverulente con intercalazioni argillose, ciottolose e concrezioni calcaree con molluschi litorali, foglio 175,cerignola), situati a nord di cerignola alle seguenti coordinate geografiche: profilo “tenuta il quarto” (qs ), lat. n 41°17’, long. e 15°55’, quota di circa 100 m; profilo “via del mare “ ( vm), lat. n 41°18’, long. e 15° 54’, quota di circa 80 m, fig. 2. il parent material dei due suoli è costituito da sabbie con intercalazioni limo-argillose, oggetto in passato di uno studio sedimentologico e paleoecologico da parte di caldara et al., 1979. all’interno dei sedimenti e dei suoli si trovano casualmente granuli di silicati di origine vulcanica (clinopirosseni, principalmente) aventi le dimensioni fig. 1localizzazione della zona di campionamento (immediatamente a nne di cerignola, indicata con asterisco). location of sampling area near cerignola, foggia province, apulia. fig. 2 profili schematici dei suoli campionati. i numeri hanno il significato seguente: 1, crosta laminare; 2, orizzonte pedogenetico; 3,crosta nodulare; 4, concrezioni a sviluppo verticale; 5, sabbie e argille del substrato. outlines of sampled soil profiles. numbers relate to following meanings: 1, laminar crust; 2, soil horizon; 3, nodular crust; 4, vertical carbonate concretions; 5, sands and clays of the parent material. della sabbia fine, presumibilmente facenti parte di materiali piroclastici emessi dal non lontano vulture, secondo quanto osservato da uno di noi (dm) nel corso di un rilevamento pedologico non pubblicato. i due profili fanno parte dell’unità tassonomica spa 1/sp2 secondo la cartografia pedologica ufficiale della regione puglia, che si estende quasi interamente sulla formazione geologica qm2 ed è costituita principalmente da calcisols, con vari gradi d’espressione dell’orizzonte calcico. il profilo qs è stato descritto alla sommità di una scarpata artificiale nei pressi della tenuta il quarto. presenta, al di sotto di un orizzonte a scuro (10 yr 3/3) di circa 15 20 cm, un orizzonte petrocalcico costituito da una crosta laminare ondulata di qualche decimetro, al di sotto della quale il suolo è incrostato, prima da accumuli nodulari di carbonato di calcio e più in profondità, da concrezioni a sviluppo verticale, poco cementate, che arrivano fino al contatto con le sabbie del substrato. il profilo vm è sostanzialmente simile, anche se la crosta laminare compare entro l’orizzonte di accumulo dei carbonati a circa 50 cm di profondità e il profilo pedologico è meno sviluppato. (fig. 2). in entrambi i suoli, la reazione è sempre alcalina e l’orizzonte superficiale appare ben umificato ed è in genere lavorato fino al limite superiore del petrocalcico, mentre la tessitura è franco-grossolana nel suolo qs e franco-fine nel suolo vm. l’indagine micromorfologica ( microscopia ottica ) e la microscopia elettronica sono state da moltissimo tempo applicate allo studio delle croste carbonatiche da parte sia di pedologi (da bal., 1975 a ould mohamed & bruand, 1994 ) che di geologi e petrografi del sedimentario ( da james, 1972 a wright, 1990 a alonso zarza, 2002 e a shankar n., achyuthan h., 2007 ). la crosta calcarea presente in puglia è stata studiata da magaldi, 1983; da carnicelli et al., 1989, e più di recente, da climaco et al., 1992, che hanno eseguito uno studio sulla morfologia e sulla distribuzione del calcrete nella capitanata tra i fiumi fortore e ofanto. in precedenza magaldi (1983 ) aveva eseguito una serie di osservazioni in sezione sottile su questi e altri profili della puglia, riscontrando che la crosta laminare a livello microscopico si presenta, sia in forma nodulare che in forma fogliettata, la prima costituita da calcite micritica con zone a lublinite (stoops, 1976),la seconda da calcite micro-sparitica in lamine compatte e ondulate. questo studio si è quindi avvalso delle sole tecniche di microscopia elettronica a scansione (sem) condotte, sia su frammenti di crosta nodulare, che fogliettata. i frammenti, opportunamente trattati, sono stati esaminati al microscopio elettronico a scansione, presso il centro di microscopia elettronica dell’università di l’aquila. ad integrazione delle osservazioni sem, sono state eseguite analisi “ elementali “ per mezzo dei raggi x prodotti con la stessa strumentazione (sem-edx). risultati un’approfondita analisi al sem, ha permesso di riconoscere in tutti campioni esaminati (4 campioni in più repliche per ciascuno dei due profili) la contemporanea presenza, anche se con differente intensità, delle due microstrutture proposte alcuni anni fa da wright (1990 ): la fabric α o fabric inorganica, che corrisponde alla struttura macroscopica k di gile 1961 e di gile et 425microstrutture della crosta ... al., 1966 ed è caratterizzata da una massa di fondo microsparitica o sparitica, con grandi cristalli scalenoedrici e romboedrici di calcite e noduli carbonatici, ecc., e la fabric β o fabric organica, microstruttura dominata da forme di origine biologica come la calcite aciculare,i rizoliti ed altre. le forme della calcite secondaria riscontrate al sem sono qui di seguito descritte e interpretate, sulla base della letteratura internazionale e della esperienza diretta in campagna, distinte sulla base del profilo dove sono più frequenti o addirittura esclusive. si è preferito usare la terminologia inglese, seguita dalla traduzione italiana, per facilitare il riferimento con la letteratura scientifica internazionale più recente. crosta del profilo vm. presenta il maggior numero di morfologie, proprie della fabric β e in minor grado quelle della fabric α. rhombohedral crystals (cristalli romboedrici) rappresentano la forma più comune della calcite presente nel petrocalcico. sono cristalli con poche facce romboedriche in genere allungate ma anche equidimensionali con dimensioni comprese tra 2-3 e 10 µm. secondo courty et al., (1989) la neoformazione di grandi cristalli di questa forma è determinata da soluzioni contenenti solo bicarbonato, che precipita in assenza d’ostacoli all’accrescimento cristallino. chadwick et al., 1989 citati da wright & tucker, 1991, ritengono che questi cristalli siano più comuni in suoli con elevato contenuto salino, scarsa quantità di sostanza organica e breve durata dei periodi umidi. in accordo con l’interpretazione di wright (1990) questi cristalli sono tipici della fabric α. kapur et al., (1993) suggeriscono che cristalli di questa morfologia si siano formati, in un paleosuolo del quaternario della turchia, in seguito alla deposizione da soluzioni concentrate, durante uno stadio “interpluviale di disseccamento” (fig. 3 a). needdle shaped crystals (cristalli aciculari) corrispondono alla lublinite; ( stoops, 1976).sono cristalli aghiformi lunghi circa 10 µm in media, a volte con forme cilindriche molto strette (microrods?) .secondo james (1972) e folk, (1976) sarebbero il risultato di una cristallizzazione rapida da soluzioni sovrassature ricche in mg, che inibirebbe la crescita di grossi cristalli. si ritiene che questa calcite sia dovuta al metabolismo di alghe e funghi (krumbein, 1968; wright & tucker, 1991; wright, 1990 e 1991). altri autori attribuiscono la formazione di questi cristalli ad una azione congiunta delle ife fungine e di batteri viventi su di esse (esteban,1973; callot 1985; ould mohamed & bruand, 1994). diversa l’opinione di knox (1977), e stoops (1990), che interpretano questi cristalli come una fase primitiva della cristallizzazione della calcite. da questi cristalli secondo ducloux et al., (1984) si formerebbero in seguito cristalli scalenoedrici e successivamente, romboedrici. l’ipotesi d’altra parte non è in contrasto con un’origine biologica (prodotta dal metabolismo dei funghi) di questa morfologia come sembra ormai internazionalmente accettato (alonso zarza, 2002). questa forma, costituita da calcite a basso contenuto in mg, è presente in tutti i campioni. (fig.3 b e c ). rice-grains crystals (cristalli a forma di grani di riso) lunghi una decina di micron e larghi la metà, sono cristalli affusolati con facce romboedriche allungate e tracce di dissoluzione.sono stati descritti da wright, 1990 come appartenenti alla fabric α (facies inorganica) ma non ne viene fornita l’interpretazione (fig. 3 d). tubules (tubicini) tubicini a sezione cilindrica, superficie rugosa,spesso biforcati e lunghi fino a 100 µ ;sembrano radici calcificate e potrebbero rappresentare una varietà a maggiori dimensioni dei neddle shaped crystals secondo quanto si deduce dalla figura 2 di ould mohamed & bruand (1994) (fig. 3 e). rhizolites (radici calcificate) tubi contorti e irregolari che rappresentano intrecci radicali calcificati e sono tipici delle fabric di tipo β (wrigth,1990). compaiono solo in un campione del profilo vm (fig. 3 f). 426 fig. 3 a cristalli romboedrici di calcite (vm e vs). rhombohedral crystals of calcite (vm e vs). fig. 3 b intreccio di cristalli aciculari di calcite (vm). network of needle-shaped calcite crystals (vm). fig. 3 c cristalli aciculari di due generazioni (vm). two generations of needle shaped calcite crystals (vm). fig. 3 d aggregato di cristalli a forma di “grani di riso” (vm). rice-grain crystals aggregate. fig. 3 e intreccio di tubicini calcitici (vm). calcite tubules network (vm). fig. 3 f aggregato di radici calcificate (vm). rhizolites aggregate(vm) fig.3 microfotografie sem di vari frammenti di crosta laminare carbonatica con indicazione del profilo di provenienza. sem micrographs of some laminar crust fragments obtained from indicated soil profile d. magaldi & m. giammatteo oltre alle precedenti morfologie della calcite, sono state osservate in un solo campione particolari morfologie di accumulo della silice amorfa, non riscontrate in letteratura, secondo quanto segue. sponges (spugne) accumuli spugnosi di silice con micro-forme di corrosione regolari successive, forse d’origine animale e /o radicale (fig. 4 a e fig. 4 b). i forellini potrebbero essere stati causati dall’uscita di 427 fig. 4 a accumulo spugnoso di silice colloidale con vacuoli dovuti a perdita di fluidi (vm). spongy heap of colloidal silica with small holes determined by fluids expulsion. fig. 4 c accumulo sferoidale di silice probabilmente in sostituzione di strutture organiche (vm). spherical silica heap perhaps as replacement of some organic structure (vm). fig. 4 d particolare della precedente (vm). particular of the previous one (vm). fig. 4 e cristalli scalenoedrici di calcite in distribuzione disordinata (qs). random arrangement of calcite scalenohedral crystals (qs). fig. 4 f distribuzione a nido d’ape dei cristalli di calcite(qs). honeycomb fabric of calcite crystals (qs). fig. 4 b come la precedente. si notino i solchi “vermiformi” di origine sconosciuta (vm). as the previous one. note the worms –like furrows whose origin is unknown. fig. 4 microfotografie sem di frammenti di crosta a composizione silicea e carbonatica con indicazione del profilo d’appartenenza. sem micrographs of siliceous and carbonate laminar crust fragments with indication of related soil profile. microstrutture della crosta ... fluidi, analogamente a quanto riferito da smart e tovey, 1981, pag.106, foto 11.23. spheroids (sferoidi)accumuli sferoidali schiacciati di silice in sostituzione di strutture organiche (spore?) (fig. 4 c e fig. 4 d). la silice colloidale sostituisce il carbonato di calcio probabilmente in conseguenza di variazioni di ph. secondo courty et al., 1989,la silice di neoformazione nel suolo proviene di norma dall’alterazione dei silicati e il processo responsabile del suo arricchimento nell’orizzonte sarebbe proprio di ambiente aridi a ph elevato. concentrazioni di silice colloidale sia in forma laminare che sferoidale, sono ricordate peraltro da boettinger & southhard (1990) in un typic durorthid del mojave desert della california. anche la soil taxonomy (1999) riferisce che alla cementazione dell’orizzonte petrocalcico contribuisce una certa percentuale di silice. crosta del profilo qs. vi si osserva una minore varietà di forme, la maggior parte delle quali appartengono alla fabric β, sia pure con frequenza minore rispetto al precedente crosta : rhombohedral crystals, needdle – shaped crystals e, molto raramente i tubules. sono sempre assenti i rizolithes. la forma che invece sembra essere esclusiva del profilo,appartenente alla fabric di tipo α e presente in tutti i campioni esaminati, è qui di seguito descritta. scalenohedral crystals (cristalli scalenoedrici). cristalli allungati fino a circa 10 -20 µm, con bordi sia regolari che irregolari (fig. 4 e). forse corrispondono agli spindle calcite crystals di ould mohamed & bruand (1994). come ricordato in precedenza (ducloux et al., 1984) rappresenterebbero una forma cristallina intermedia tra i cristalli aciculari e la calcite romboedrica. kostov & kostov (1999) nel loro fondamentale trattato sulla forma dei minerali in rapporto al microambiente di formazione, riferiscono una morfosequenza della calcite, dove i cristalli scalenoedrici e romboedrici acuti sarebbero propri di un ambiente ossidante con bassa disponibilità di co2 e di ioni oh. la maggior parte dei campioni è caratterizzata da una distribuzione disordinata dei cristalli di calcite con poche cavità che tuttavia, a volte si dispongono a formare una struttura a nido d’ape (fig. 4 f). composizione chimica.si noti la scarsità del magnesio nelle 2 croste e la presenza del cloro e dello zolfo nei campioni provenienti dalla crosta situata a quota minore (vm), dovuta forse alla circolazione di acque contaminate da sali marini all’interno del profilo pedologico oppure alla originaria composizione del parent material che come ricordato in precedenza, è un sedimento di ambiente marino. insieme al fosforo,questi elementi potrebbero inoltre indicare la presenza di sostanza organica entro la crosta. sempre nella vm, si osserva un valore piuttosto elevato di silicio che dovrebbe corrispondere ad un 5% di silice. la crosta qs appare invece sensibilmente impoverita di silicio e arricchita in calcio e magnesio, mentre si trovano al disotto delle possibilità di misura il potassio, il cloro e il fosforo. si noti il valore del calcio superiore di 6,8 unità a quello stechiometrico del carbonato puro (40%) dovuto all’errore della metodologia. discussione dei risultati le osservazioni al sem evidenziano l’esistenza delle due microstrutture α e β in tutti i campioni con la prevalenza di quella α nei campioni del petrocalcico qs dove la laminar crust appare quasi in superficie, e di quella β nel petrocalcico con laminar crust più profonda (vm). ancora una volta viene riscontrato che gli orizzonti petrocalcici non possiedono esclusivamente un solo tipo di fabric ma quasi sempre una combinazione delle due secondo, quanto già osservato in precedenti ricerche (wright, 1990; achyuthan, 2003; shankar & achyuthan, 2007). queste strutture sono in ottimo accordo con un ambiente di clima mediterraneo semiarido e una sufficiente disponibilità di carbonato di calcio nel parent material (wright (1990) anche se in altre località della terra si è rivelato predominante l’apporto eolico (gile et al., 1966). a conclusioni simili giungono anche climaco et al.,1992, che parlano di clima “arido-semiarido tendente al pre-desertico”, proprio per i suoli della capitanata. la diversa frequenza delle morfologie della calcite suggerisce tuttavia ulteriori considerazioni sul microambiente di formazione dei 2 orizzonti petrocalcici. la crosta qs sembra caratterizzata da una più intensa evapotraspirazione con una lenta ma continua deposizione di carbonato di calcio, in condizioni tali da dare origine a cristalli euedrali romboedrici e scalenoedrici, quest’ultimi assenti nella fabric β ; l’azione biologica è trascurabile e la composizione chimica rivela bassi contenuti in silice e un certo arricchimento in calcio e magnesio, che testimonierebbero condizioni di formazione in ambiente arido o semiarido a ph elevato e con scarso drenaggio, forse paragonabili a quelle degli attuali aridisols della classificazione usda (calciorthids o paleorthids). secondo quanto risulta dallo studio di alcuni orizzonti petrocalcici della parte meridionale dell’india (shankar & achyuthan, 2007), gli orizzonti petrocalcici laminari si sarebbero formati in un ambiente morfologicamente stabile, moderatamente vicino alla superficie del suolo,in condizioni climatiche semi-aride, in seguito a processi pedogenetici e in parte idrogeologici. al contrario la crosta del profilo vm appare più fortemente modellata dalla azione radicale e da quella dei microrganismi e infine da oscillazioni di ph e presumibilmente di umidità,che tendono a mobilizzare la silice 428 tab.1 composizione “elementale” media (11 campioni in totale) delle due croste calcaree; tr = trascurabile. considerando che la tecnica di misura analizza frammenti piccolissimi e irregolari e l’errore (intorno al 15 % ) che questa comporta, si è preferito lasciare i valori espressi come percentuale del singolo elemento sul totale anziché presentarli come ossidi. si al mg ca k s cl p altri vm 2,36 0,44 0,18 34,43 0,48 0,67 0,68 0,04 60,72 qs 0,76 0,35 0,33 46,80 tr 0,29 tr tr 51,47 d. magaldi & m. giammatteo dai minerali primari (silicati delle sabbie e delle ceneri vulcaniche) e a determinarne la deposizione sui granuli calcitici ed entro strutture organiche (quali probabilmente gli sponge e gli sferoid ) in un ambiente climatico da semi-arido a sub-umido con vegetazione prevalentemente arbustiva e erbacea (alonso zarza, 2003), non molto diverso da quello attuale, dove l’orizzonte di accumulo dei carbonati, secondo i risultati di rilevamenti pedologici non pubblicati di uno degli autori (dm), sembra formarsi anche attualmente, specialmente nei suoli su substrati a tessitura sabbiosa medio-fine ed anche in alcune tipologie dei vertisols dei dintorni di foggia. conclusioni è ormai comunemente accettato che le microstrutture della crosta calcarea e in particolare la morfologia dei cristalli di calcite può essere messa in relazione con fattori climatici, biologici e morfologici. la laminar crust, che corrisponde alla croute zonaire degli aa. francesi (vogt,1984; verrecchia, 1994) può formarsi secondo quanto risulta dalla letteratura scientifica in seguito a due differenti,anche se non antitetiche, modalità : in un caso si attribuisce la formazione del petrocalcico all’azione congiunta di processi prevalentemente abiologici superficiali dovuti al ristagno e/o al lento scorrimento di una falda idrica su una superficie poco permeabile (“stage” 4 dell’evoluzione della crosta calcarea secondo wright & tucker,1991), che danno origine alla precipitazione/ cristallizzazione della calcite all’interfaccia crosta – atmosfera, in condizioni di clima arido e semiarido (wieder et al., 1994; durand et al., 2006); nell’altro caso il processo sarebbe principalmente determinato a maggiore profondità,dalla attività biologica di numerosi organismi vegetali quali funghi,i batteri, i licheni, le alghe e le radici di alcune piante (freatofite), quest’ultime attraverso la costruzione di un intreccio a tappeto (wright et al., 1988; wright & alonsozarza,1992; alonso-zarza,1999). è logico quindi aspettarsi che la fabric alfa sia più frequente nella laminar crust abiologica che in quello biologica. in realtà, come è apparso anche in questo studio, le 2 fabric coesistono, anche se tendono ad essere predominanti in un gruppo di campioni rispetto all’altro. si può allora concludere che il profilo qs, situato a quota più elevata, possiede una crosta laminare superficiale prevalentemente di origine inorganica, dovuta alla forte evapotraspirazione e alla circolazione di acque vadose, in condizioni climatiche aride o semiaride, mentre la crosta laminare entro il profilo vm, posto a quota più bassa, appare più decisamente di origine biologica in condizioni climatiche tali da favorire l’instaurarsi di una vegetazione stabile e quindi variabili tra semiaride e sub umide. secondo la carta ecopedologica d’italia in scala 1:250.000 (european communities, 2003), la zona di provenienza dei campioni, caratterizzata da terrazzi sabbioso-conglomeratici inclinati verso il mare, ha un clima da mediterraneo oceanico a mediterraneo suboceanico,in definitiva più umido di quanto risulti dallo studio delle 2 laminar crust. alla luce di quanto si evince dalla abbondante letteratura al riguardo (ruellan, 1971; fedoroff et al., 1990, kaemmerer et al., 1991; wieder et al.; 1994; tandon & kumar,1999; achyuthan, 2003; alonso-zarza, 2003; shankar & achyuthan, 2007) la crosta laminare può essere presa in considerazione come un discreto indicatore delle condizioni climatiche del passato ne segue che le 2 laminar crust sono testimonianza di 2 differenti momenti climatici del pleistocene, più aridi rispetto al clima attuale. al contrario,anche se la loro formazione in puglia ha richiesto probabilmente tempi relativamente lunghi, non vi sono attualmente indicazioni che ne suggeriscano l’età, salvo i criteri geomorfo-stratigrafici.si può tuttavia ipotizzare che i due suoli, leggermente differenti come evoluzione pedogenetica, siano anche differenti non solo per ambiente di formazione, ma anche cronologicamente : qs, posto a quota più elevata e maggiormente evoluto, potrebbe quindi essere più vecchio di vm. ringraziamenti l’interpretazione delle morfologie mostrate nelle figure 4 a, 4 b, 4 c e 4 d, forse segnalate per la prima volta, si basa su ipotesi e suggerimenti gentilmente forniti alcuni anni fa dai seguenti colleghi stranieri: mc hardy di abeerden, scotland; p.smart di glasgow, scotland; d. yaalon di jerusalem, israel; l. wilding di college station, texas, che qui vogliamo sentitamente ringraziare insieme ai colleghi s. carnicelli e g.ferrari dell’università di firenze riguardo alle utili informazioni fornite sul sito di campionamento e a d. ranalli dell’università dell’aquila per l’elaborazione grafica. bibliografia achyuthan h., 2003 petrologic analysis and geochemistry of the late neogene-early quaternary hardpan calcretes of western rajasthan, india . quaternary international 106-107, pp. 3-10. alonso-zarza a.m.,1999 initial stages of laminar calcrete formation by roots: examples from neogene of central spain. sedimentary geology 126, pp. 177-191. alonso-zarza a.m. 2003 paleoenvironmetal significance of palustrine carbonates and calcretes in the geological record. earth science reviews 60, pp.261-298. bal l., 1975 carbonate in soil: a theoretical consideration on, and proposal for its fabric analysis,i and ii. neth.j.agric.sci.,23; pp.18-35; pp. 163-176. birkeland p.w., 1984 soils and geomorphology. oxford university press, new york, 372 pp. boettinger j., l. & southard m.,1990 micromorphology and mineralogy of a calcareous duripan formed on granite residuum, mojave desert, california, usa. in l.a. douglas (ed.): soil micromorphology : a basic and applied science. developments in soil science, 19, 409-416, elsevier. caldara m., colella a.., & d’alessandro a., 1979 studio sedimentologico e paleoecologico di alcune sezioni pleistoceniche affioranti presso cerignola (fg). riv. ital. paleont. 85 (1), pp.173-242. callot g., guyon, a. & mousain, d.,1985 interrelations entre aiguilles de calcite et hyphes myceliens. agronomie 5,pp.209-216. 429microstrutture della crosta ... climaco a., daniele m.c.,di nocera s. & zamparelli v., 1992 studio preliminare delle croste calcaree (caliche) della capitanata (puglia).soc. naz. di sc.,let. e art. in napoli; rend. acc. sc. mat. fis., pp.165-183. carnicelli s., ferrari g.a. & magaldi d., avec la collaboration de billwiller g., di nocera s., palmentola g., pennetta g.& zamparelli v., 1989 les accumulations carbonatées du type “calcrete” dans les sols et formations superficielles d’italie méridionale. mediterranée, 23, 51-59. courty m.a., goldberg p., & macphail r., 1989 soils and micromorphology in archaeology. cambridge university press. dinçer. i, altay a. & magaldi d., 2007 relationship between micromorphological characteristics and engineering parameters of caliche (calcrete). il quaternario, 20 (2), pp.137-150. ducloux j., butel p. & dupuis t., 1984 microsequence mineralogique des carbonates de calcium dans une accumulation carbonate sous galets calcaires, dans l’ouest de la france. pedologie 34, pp.161177. durand n., gunnell y., curmi p.& ahmad s.m., 2006 pathways of calcrete development on weathered silicate rocks in tamil nadu, india: mineralogy, chemistry and paleoenvironmental implications. sedimentary geology,192, pp.1-18. esteban m. & klappa c.f.,1983 subaerial exposure environments. in: scholle p.a., bebout d.g., moore c.h.(eds): carbonate depositional environnements. am.assoc.petr.geol.mem., 33, pp. 1-96. european communities, 2003 carta ecopedologica d’italia in scala 1 :250.000. relazione divulgativa a cura di e. rusco, n. filippi, m. marchetti, l. montanarella. es, eur 20774 it. fedoroff n., courty m.a. & thompson m.l., 1990 micromorphological evidence of palaeoenvironmental change in pleistocene and holocene paleosols. in l.a. douglas (ed.): soil micromorphology: a basic and applied science. developments in soil science, 19, pp. 653-665. fao, 2006 world reference base for soil resources: a framework for international classification, correlation and communication. world soil resources reports 103, rome. folk r.l.,1974 the natural history of crystalline calcium carbonate :effect of magnesium content and salinity. j.sedim.petrol., 44, pp. 40-53. gile l.h.,1961 a classification of ca horizons in soils a desert region, dona ana country, new mexico. soil sci.soc.am.proc., 25, pp.52-61. gile l.h., peterson f.f. & grossman r.b.,1965 the k horizon: a master horizon of carbonate accumulation. soil.sci., 97, pp.7482. gile l.h., peterson f.f. & grossman r.b., 1966 morphological and genetic sequences of carbonate accumulation in desert soils. soil science 101, pp. 347-360. goudie a.s., 1983 calcrete. in: goudie a.s.& pye f.(eds.), chemical sediments and geomorphology., academic press, london, pp. 93 -131. i.f.g.international focus group on rural road engineering, 2006 calcrete. technical information. http://www.ifgworld.org. james n.p., 1972 holocene and pleistocene calcareous crust (caliche) profiles :criteria for sub aerial exposure. jour.sed.petr. 42 (4 ) pp. 817-836. kaemmerer m., revel j.c., berrier j., bruand a., lefevre d., 1991 dissolution et précipitation des carbonates dans des sols (calcretes) en zone aride, bassin de ksabi, moyenne moulouya, maroc: conséquence sur la désertification. arid soil research and rehabilitation, 5, pp.105-126. kapur s.,yaman s., gokçen & yetis c.,1993 soil stratigraphy and quaternary caliche in the misis area of the adana basin, southern turkey. catena, 20, pp.431-445. knox g.j., 1977 caliche profile formation, saldanha bay (south africa). sedimentology, 24, pp. 657674. kostow i.& kostow r.i, 1999 crystal habits of minerals. pensoft, 415 pp. krumbein,1968 geo-microbiology and geochemistry of the " nari-lime-crust " (israel). in g. muller & g.m. friedman (eds.) recent developments in carbonate sedimentology in central europe. springer –verlag, berlin, pp. 138-147. magaldi d., 1983 calcareous crust (caliche) genesis in some mollisols and alfisols from southern italy :a micromorphological approach. in p.bullock & c.p.murphy (eds.): soil micromorphology, vol. 2.a b academic press, uk, pp. 623-636. ould mohamed s., bruand a., 1994 morphology and origin of secondary calcite in soils from beauce, france. in a.j. ringose-voase and g.s. humphreys (eds.): soil micromorphology: studies in management and genesis. developments in soil science 22, elsevier,amsterdam, pp. 27-36. ruellan, 1971 contribution à la connaissance des sols des régions méditerranéennes: les sols à profile calcaire différencié des plaines de la basse moulouya (maroc oriental). mémoire orstom, 54, paris. shankar n. & achyuthan h., 2007 genesis of calcic and petrocalcic horizons from coimbatore, tamil nadu: micromorphology and geochemical studies. quaternary international, 175, pp. 140-154. soil survey staff,1999 soil taxonomy. usda, agricolture handbook 436, usda-natural resources conservation service, washington, dc. soil survey staff, 2006 keys to soil taxonomy. 10th ed. usda-natural resources conservation service, washington, dc. stoops g.,1976 on the nature of “lublinite” form hollanta (turkey). american mineralogist, pp. 61172. stoops g. & delvigne j., 1990 morphology of mineral weathering and neoformation. ii neoformations. in l.a.douglas (ed.): soil micromorphology:a basic and applied science. developments in soil science 19, 483-492. tandon s.k. & kumar s., 1999 semiarid/arid zone calcretes: a review. in: a.k.singhvi & e. derbyshire (eds.): paleoenvironmental reconstruction in arid lands. balkema; 109-152. verrecchia e., 1994 l’origine biologique et superficielle des croutes zonaires. bull.soc geol.fr., 165; 583-592. wieder m., sharabani m. & singer a.,1994 phases of d. magaldi & m. giammatteo calcrete (nari) development as indicated by micromorphology. in a.j. ringose-voase & g.s. humphreys (eds.): soil micromorphology: studies in management and genesis. developments in soil science 22, elsevier,amsterdam,pp. 27-36. wright v.p.,1990 a micromorphological classification of fossil and recent calcic and petrocalcic microstructures. in l.a.douglas (ed.): soil micromorphology: a basic and applied science. developments in soil science, elsevier, amsterdam, pp. 401-407. wright v.p., 1991 calcretes: an introduction. in : v.p. wright & m.e.tucker (eds.), calcretes .ias reprint series, 2, blackwell, oxford, pp.1-22. wright v.p., platt n.h. & wimbledon, w., 1988 biogenic laminar calcretes: evidences of calcified root mat in paleosols. sedimentology, 35, pp. 603-620. wrigth v.p. & alonso-zarza a.m.,1992 significado de la composition isotopica (δ13c y δ 18o) en paleosuelos carbonatados, mioceno de la cuenca de madrid. geogaceta, 11, 61-13. wright v.p & tucker m.e (eds.), 1991 calcretes. ias reprint series, 2, blackwell, oxford, pp.1-22. yaalon d.h.,1988 calcic horizon and calcrete in aridic soils and paleosols: progress in the last twenty years. soil sci.ame.agron. abstracts 431 ms. ricevuto il 2 marzo 2008 testo definitivo ricevuto il 19 giugno 2008 ms. received: march 2, 2008 final text received: june 19, 2008 microstrutture della crosta ... << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /none /binding /left /calgrayprofile (dot gain 20%) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /error /compatibilitylevel 1.4 /compressobjects /tags /compresspages true /convertimagestoindexed true /passthroughjpegimages true /createjdffile false /createjobticket false /defaultrenderingintent /default /detectblends true /colorconversionstrategy /leavecolorunchanged /dothumbnails false /embedallfonts true /embedjoboptions true /dscreportinglevel 0 /emitdscwarnings false /endpage -1 /imagememory 1048576 /lockdistillerparams false /maxsubsetpct 100 /optimize true /opm 1 /parsedsccomments true /parsedsccommentsfordocinfo true /preservecopypage true /preserveepsinfo 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malatesta geologist and palaeontologist francesco zarlenga enea cr.casaccia (utrinn), roma corresponding author: <francesco.zarlenga@enea.it> alberto malatesta, former professor at the rome university sapienza in the master course of geological sciences, geologist and palaeontologist, passed away when he was 92 years old on 9th october, 2007. a. malatesta was born in livorno the 15th of july 1915; there he attended classic studies at the secondary jesuit school “niccolini-guerrazzi” and obtained his degree on 1933. he graduated in natural science at the pisa university, tutored by prof. alberto carlo blanc. immediately after the degree he started to teach science at the secondary school of piombino; there he met miss gianna torricelli, who became his wife some years later. they had three children: giuseppe, gabriella and giovanna. during 1939, a. malatesta abandoned teaching and left for east africa (ethiopia) as a geologist of the reale corpo delle miniere. in this period he mainly studied the geology of the awash valley (unfortunately only in very recent times important fossil remains were discovered there). at the beginning of the second world war he was in ethiopia as second lieutenant of the italian army. after a romantic adventure spent flying between ethiopia and eritrea, he was captured and kept prisoner by the english troops. a very serious form of malaria stopped his run and he was transferred first to the asmara harbour and then to the english war prisoner camp at peshawar (pakistan). notwithstanding his prisoner status, after the 8th september 1943 he was able to carry out some scientific missions on the himalayan range and in very interesting paleontological areas. the observations made during these field surveys were published some years later on the scientific journals atti della società toscana di scienze naturali (1948) and bollettino del servizio geologico d’italia (1951). during 1948, he came back in italy and, starting from 1950, he was employed by the italian “servizio geologico nazionale”. there he worked as a field geologist and carried out the geologic survey of several 1:100.000 geological sheets in central and southern italy, sardinia and sicily. this activity gave him a huge knowledge of the italian quaternary geology and the possibility to gather a very large collection of fossil remains that he studied during the following years. f. zarlenga 6 a. malatesta attained the “libera docenza” in palaeontology in 1959 and he became associate professor of palaeontology in 1981. he taught “palaeontology” at the messina university (1960-1962) and at the sapienza università di roma (1962-1973). at the sapienza università di roma he gave also the courses “quaternary geology and palaeontology” (1973-1975 and 1981-1985) and “vertebrate palaeontology” (19751981). during this period he headed several paleontological expeditions in crete, sicily and sardinia caves. he retired on november 1985 when he was 70 years old, but he did not stop his research activity as testified by several scientific publications dated up to 1994. a. malatesta has been author or co-author of 104 scientific papers dealing with pliocene and quaternary geology and geomorphology, invertebrate (molluscs) and vertebrate (insular quaternary mammals) palaeontology and palaeoethnology. in his book on quaternary geology and palaeontology, he synthesized the general scientific approach to the study of quaternary problems on the base of his own field experiences and his huge global geo-paleontological culture. among the most important results deriving form the scientific activity of a. malatesta it is possible to mention his synthesis of the quaternary geology of the roma surroundings (1978, 1980) and his many contributes to the knowledge of the italian plio-quaternary paleontology. born first as a geologist, his biological and paleontological preparation, gained at the pisa university when he was a student, lead him to solve some problems met during the geological surveys with the aid of taxonomical and palaeoenvironmental studies on mollusc and vertebrate remains. he studied fossil molluscs collected in the quaternary of sicily, in the pliocene of umbria and in the paleocene of mozambique, writing important monographies (among which the “malacofauna di grammichele”, 1960, 1963 and the “malacofauna pliocenica umbra”, 1974). such monographies are benchmarks for the italian, and in some cases, for the worldwide mollusc palaeontology. studying molluscs he erected 1 new genus, 1 new subgenus, 22 new species and 3 new subspecies. at the same time, the recovery of dwarf cervids during his geological surveys in sardinia aroused his interest on the phenomena of “nanism” and “gigantism” of insular mammalian taxa and induced him to organize several paleontological expeditions in sardinia, sicily and crete. these experiences lead him to propose a new model for the mammal population of insular districts and the consequent endemism (1980). he erected 1 new genus, 1 new subgenus and 3 new species of mammals. under his guide, a roman school on vertebrate palaeontology was born and several researchers at the sapienza università di roma and at roma tre university still carry on his heritage today. list of publications malatesta a. (1939) sul rinvenimento di alcuni nuovi esemplari fossili di arbacia. boll. soc. geol. it., 58, pp. 1-5. bacci a., malatesta a., tongiorgi e. (1939) di una formazione glaciale rissiana riscontrata a livorno nei sedimenti della fase costruttiva del ciclo tirreniano. atti soc. tosc. sci. nat. proc. verb., 48, pp. 74-85. malatesta a. (1940) ricerche di preistoria nella provincia di livorno. boll. stor. liv., 4, pp. 1-15. malatesta a. (1940) l’industria musteriana di livorno. atti 28ma riun. soc. it. sci. nat., 4, pp. 367-370. cecioni g. & malatesta a. (1940) le valli del torrente chioma e del rio popogna nei monti livornesi. natura, 31, pp. 62-69. malatesta a. (1942) le formazioni pleistoceniche del livornese. atti soc. tosc. sci. nat., mem., 51, pp. 145-206. malatesta a. (1948) formazioni eoceniche del distretto di kangra (punjab-india). atti soc. tosc. sc. nat., mem., 51, pp. 145-206. malatesta a. (1950) sulla grotta reale a porto azzurro (elba). riv. sc. preist., 5, pp. 90-94. malatesta a. (1951) considerazioni sugli ochtonidae fossili e viventi. boll. serv. geol. d’it., 71, pp. 121146. malatesta a. (1951) ricerche preistoriche nella valle della lima (lucca). riv. sc. preist., 6, pp. 79-83. malatesta a. (1951) osservazioni sull’estensione dei ghiacciai quaternari nella valle di kangra (himalaya esterna). boll. serv. geol. d’it., 73, pp. 63-75. malatesta a. (1952) il calabriano fra castiglioncello e rosignano. boll. serv. geol. d’it., 73, pp. 171-184. malatesta a. & martelli g. (1953) sull’origine e sull’età della porfirite di calbona (alghero). boll. serv. geol. d’it., 74, pp. 445-456. malatesta a. (1953) alcuni risultati della campagna geologica (1953). boll. serv. geol. d’it., 75, pp. 724-729. malatesta a. (1953) note di stratigrafia quaternaria. in: risultati del rilev. f° 192, alghero, sardegna. boll. serv. geol. d’it., 75, pp. 371-395. malatesta a. & torrente a. (1953) pliocene e pleistocene a caltagirone. boll. serv. geol. d’it., 75, pp. 399-411. malatesta a. (1954) fossili delle spiagge tirreniane. in: risultati del rilev. f° 192, alghero, sardegna. boll. serv. geol. d’it., 76, pp. 9-17. malatesta a. (1954) il cosiddetto campanile della necropoli nuragica di s.andrea priu (bonorva). riv. sci. preist., 9, pp. 105-113. malatesta a. (1954) primo dente di elefante fossile rinvenuto in sardegna. quaternaria, 1, pp. 97-103. malatesta a. & settepassi f. (1954) fossili delle formazioni continentali quaternarie. boll. serv. geol. d’it., 76, pp. 33-39. lipparini t., malatesta a.,nicosia m.l. & valdinucci a. (1955) pliocene e quaternario del capo milazzo in sicilia. boll. serv. geol. d’it., 77, pp. 1-26. malatesta a. & segre a.g. (1955) note illustrative della carta geologica d’italia. f.111, livorno, scala 1:100.000. min. dell’industria e del comm. servizio geologico. malatesta a. (1955) faune a cyprina islandica tra piazza armerina e mazzarino. boll. serv. geol. d’it., 77, pp. 447-454. malatesta a. (1955) contributi alla conoscenza delle faune neogeniche e quaternarie della siclia. iv: “dentilucina doderleini” d.st. nel pliocene inferiore della sicilia. boll. serv. geol. d’it., 77, pp. 455-460. alberto malatesta geologist and palaeontologist 7 malatesta a. (1955) risultati preliminari del rilevamento in sicilia e nelle isole egadi. boll. serv. geol. d’it., 76, pp. 517-521. malatesta a. & nicosia m.l. (1955) i fossili del pliocene e del pleistocene di agrigento della collezione lomi. boll. serv. geol. d’it., 77, pp. 173-180. malatesta a. (1956) conchiglie. il mediterraneo, 1 (3), p. 2. malatesta a. & motta s. (1956) notizie preliminari di geologia messinese. boll. serv. geol. d’it., 78, pp. 463-466. malatesta a. & segre a.g. (1956) considerazioni paleontologiche e sistematiche sulla turris (fusiturris) undatiruga biv. atti soc. tosc. sci. nat., 63, pp. 12-32. jacobacci a., malatesta a. & martelli (1956) – prime notizie sul nuovo rilevamento geologico dei monti peloritani. boll. serv. geol. d’it., 78, pp. 447-454. malatesta a. (1957) terreni, faune ed industrie quaternarie nell’arcipelago delle egadi. quaternaria, 4, pp. 165-190. malatesta a. (1957) on thais (polytropa) lapillus (linnè) in the pleistocene of sicily. journ. palaeont. soc. india, dn wadia jub. numb., 2, pp. 113118. malatesta a & pannuti s. (1957) giacimento preistorico di superficie presso acilia. bull. paletn. ital., n.s., 66, pp. 269-275. malatesta a. (1958) cenni sui risultati delle campagne geologiche effettuate durante l’anno 1956. (sicilia: pattiappennino meridionale: benevento). boll. serv. geol. d’it., 79, pp. 475-477. malatesta a. (1958) osservazioni sul pliocene ed il pleistocene della costa settentrionale della sicilia tra gualtieri sicaminò e gioiosa marea. boll. serv. geol. d’it., 79, pp. 291-326. malatesta a. (1959) notizie preliminari su una fauna del pleistocene siciliano. boll. serv. geol. d’it., 80, pp. 77-81. malatesta a. (1959) note di geologia e morfologia sulla valle caudina e sulla valle del f. calore. boll. serv. geol. d’it., 80, pp. 255-260. malatesta a. (1959) di un livello fossilifero attraversato dalla galleria di bomba nella valle del sangro. boll. serv. geol. d’it., 80, pp. 261-273. malatesta a. (1960) malacofauna pleistocenica di grammichele (sicilia). mem.per servire alla descrizione della carta geologica d’italia, 12, pp. 1196 malatesta a. & motta s. (1961) i terreni del pleistocene. in: “piano di studio sullo stretto di messina per il collegamento della sicilia con la calabria”. regione siciliana, 1, pp. 1-66. jacobacci a., malatesta a. & motta s. (1961) piano di studi nello stretto di messina per il collegamento della sicilia con la calabria. i. ricerche geologiche. pp. 1-66. malatesta a. (1962) mediterranean polyplacophora cenozic and recent. geol. rom., 1, pp. 145-171. malatesta a. (1962) il cane selvaggio del pleistocene della sardegna. geol. rom., 1, pp. 173-189. malatesta a. (1963) malacofauna pleistocenica di grammichele (sicilia). pt. ii, scaphopoda e bivalvia. mem.per servire alla descrizione della carta geologica d’italia, 12, pp. 197-392. malatesta a. (1964) trias fossilifero a marettimo nelle isole egadi. atti soc. tosc.sc.nat., 71, 1-15. malatesta a. (1964) fossili eocenici del territorio di briga e tenda nelle alpi marittime. geol. rom., 3, pp. 65-92. malatesta a. (1964) über einige pleistozane susswassermollusken aus mittel-italien. l. arch. moll., 93, pp. 151-162. jacobacci a., malatesta a., martelli g., stampanoni g. (1967) note illustrative della. carta geologica d’italia alla scala 1:100.000. f° 163 «lucera». min. dell’industria, del comm. e dell’artigianato servizio geologico d’italia. malatesta a., perno u. & stampanoni g. (1967) note illustrative della carta geologica d’italia. alla scala 1:100.000. f°175. cerignola. min. dell’industria e del comm. e dell’artigianato servizio geologico d’italia. dragone f., maino a., malatesta a. & segre a.g. (1967) note illustrative della c.g.i. alla scala 1:100.000. foglio 149 (cerveteri). min. dell’industria e del comm. e dell’artigianato servizio geologico d’italia. conato v., malatesta a. & valletta m. (1967) calabriano ad arctica islandica sulla costa meridionale d’abruzzo. quaternaria, 9, pp. 261-266. compagnoni b., conato v., follieri m. & malatesta a. (1968) il calabriano di scalea. quaternaria, 10, pp. 95-123. jacobacci, a. malatesta a. and martelli g. (1969) note illustrative della carta geologica d’italia. alla scala 1:100.000. foglio 121 “montepulciano”, min. dell’industria e del comm. e dell’artigianato servizio geologico d’italia. malatesta a. (1969) conchiglie di mare che si raccolgono in terra. la conchiglia, 1 (3), p.5. malatesta a. (1969) un gruppo scomparso di bivalvi: le rudiste. la conchiglia, 1 (3), p.5. malatesta a. (1970) cynotherium sardous studiati, an extinct canid from the pleistocene of sardinia. mem. ist. pal. um., 1, pp. 1-72. malatesta a. (1970) nascita della nomenclatura binomia e della classificazione. la conchiglia, 2 (9), p.5. jacobaccii a., bergomi c., centamore e., malatesta a., malferrari n., martelli g., pannuzzi l. & zattini n. (1970) note illustrative della carta geologica d’italia. alla scala 1:100.000. fogli 115 città di castello, 122 perugia, 130 orvieto. min. dell’industria e del comm. e dell’artigianato servizio geologico d’italia. malatesta a. & suriano f. (1971) avifauna pleistocenica di alghero (sardegna). boll. serv. geol. d’it., 91, pp. 149-158. malatesta a. (1971) appunti di paleontologia generale. pp. 1-106 (cicl. in prop). malatesta a. (1974) malacofauna pliocenica umbra. mem. per servire alla descrizione della carta geologica d’italia, 13, pp. 1-498. caloi l. & malatesta a. (1974) il cervo pleistocenico di sardegna. mem. ist. it. pal. um., 2, pp. 163247. ambrosetti p., arias c., bigazzi g., bonadonna f.p., de giuli c., girotti o., kukla g., iaccarino s., malatesta a., mazzanti r., radicati di brozolo f. zarlenga 8 f. & trevisan l. (1975) guide book. meeting of the inqua. pisa perugia tarquinia. march april 1975, pp. 1-35. malatesta a. (1977) the skeleton of nesolutra ichnusae sp.n., a quaternary otter discovered in sardinia. geol. rom., 16, pp. 173-209. malatesta a. (1978) on the genus cyrnaonix helbing, 1935 (mustelidae, lutrinae) and its type species. quaternaria, 20, pp. 109-116. malatesta a. ed. (1978) torre in pietra-roma. quaternaria, 20, pp. 203-577. malatesta a. (1978) la serie di torre in pietra nel quadro del pleistocene romano. quaternaria, 20, pp. 537-577. angelelli f., caloi l., malatesta a. & palombo m.r. (1978) fauna quaternaria di venosa. cenni preliminari. atti della xx riunione scientifica dell’ist.it. di preistoria e protostoria in basilicata. 16-20 ottobre 1976, pp. 133-140. malatesta a. (1980) dwarf deer and other late pleistocene fauna of the simonelli cave in crete. accademia, nazionale dei lincei, quaderno 249, pp. 1-128. conato v., esu d., malatesta a. & zarlenga f. (1980) new data on the pleistocene of rome. quaternaria, 22, pp. 131-176. gliozzi e. & malatesta a. (1980) the quaternary goat of capo figari (northeastern sardinia). geol. rom., 19, pp. 295-347. malatesta a. (1981) appunti di paleontologia dei vertebrati. pp. 1-86 (cicl. in prop.). angelelli f., gliozzi e. & malatesta a. (1982) l’encefalo di nesogoral melonii (dehaut), nemoredino quaternario della sardegna. boll. serv. geol. d’it., 103, pp. 35-52. gliozzi e. & malatesta a. (1982) a megacerine in the pleistocene of sicily. geol. rom., 21, pp. 311-395. malatesta a. & zarlenga f. (1982) nuovo giacimento con fauna ad arctica nei dintorni di roma. quad. paleont. strat. ed evol., 2, pp. 127-128. gliozzi e. & malatesta a. (1983) i molluschi del paleocene di baixa chinauanine nel bacino del rio massintonto (maputo-mozambico). geol. rom., 22, pp. 85-145. gliozzi e., malatesta a. & palombo m.r. (1984) upper pleistocene small mammals associations from is oreris area (inglesiente) sw sardinia. geol. rom., 23, pp. 121-131. malatesta a. (1985) cause e meccanismi delle variazioni di taglia e delle modificazioni strutturali nei mammiferi quaternari delle isole mediterranee. boll. soc. paleont. it., 24, pp. 195-199. malatesta a. (1985) geologia e paleobiologia dell’era glaciale. pp. 1-282 nis ed., roma. belluomini g., malatesta a., branca m. & spano (1985) aminoacid recemization dating of sardinian raised marine deposits. boll. soc. geol. it., 104, pp. 223-229. malatesta a. & zarlenga f. (1985) il quaternario di pomezia (roma) e la sua fauna marina. boll. soc. geol. it., 104, pp. 503-514. gliozzi e., malatesta a. & zarlenga f. (1985) il quaternario della pianura pontina. in: “progetto laghi costieri”. università degli studi di roma amm. prov. di latina. belluomini g., branca m., delitala l., malatesta a. & zarlenga f. (1986) isoleucine epimerization ages of some pleistocene sites near roma. human evol., 1, pp. 1-5. malatesta a. & zarlenga f. (1986) evoluzione paleogeografico-strutturale plio-pleistocenica del basso bacino romano a nord e a sud del tevere. (sintesi preliminare). atti del 73° congresso della soc. geol. it., pp. 47-50. gliozzi e., malatesta a., ventura g. & zarlenga f. (1986) ambienti e comunità in malacofaune marine del pleistocene inferiore della bassa campagna romana. atti del 73° congresso della soc. geol. it., pp. 43-46. cassoli a., corda l., lodoli c., malatesta a., molaroni m.v. & ruggeri a. (1986) il glacialismo quaternario del gruppo ocre-velino-sirente. atti del 73° congresso della soc. geol. it. pp. 335338. cassoli a., corda l., lodoli c., malatesta a., molaroni m.v. & ruggeri a. (1986) il glacialismo quaternario del gruppo ocre-velino-sirente. mem. soc. geol. it., 35, pp. 855-867. malatesta a. & zarlenga f. (1986) evoluzione paleogeografico-strutturale plio-pleistocenica del basso bacino romano a nord e a sud del tevere. mem. soc. geol. it., 35, pp. 75-85. gliozzi e., malatesta a., ventura g. & zarlenga f. (1986) ambienti e comunità in malacofaune marine del pleistocene inferiore della bassa campagna romana. mem. soc. geol. it., pp. 35, 87-97. caloi l., gliozzi e., kotsakis t., malatesta a. & palombo m.r. (1986) osservazioni sulla paleobiogeografia dei mammiferi del pleistocene italiano. hystrix, 1: pp. 7-23, roma. gliozzi e., malatesta a., palombo m.r., (1986) upper pleistocene small mammal associations in the is oreris area (iglesiente, sw sardinia). geol. rom., 23 (1984), pp. 121-129. malatesta a. & zarlenga f. (1986) cicli trasgressivi medio pleistocenici sulle coste liguri e tirreniche. geol. rom., 25, pp. 1-8. malatesta a. & zarlenga f. (1986) northern guest in the pleistocene mediterranean sea. geol. rom., 25, pp. 91-154. willemsen g.f. & malatesta a. (1987) megalenhydris barbaricina sp.nov., a new otter from sardinia. proceedings of the koninklijke nederlandse akademie van wetenschappen., 90, pp. 83-92. carboni m.g., malatesta a. & zarlenga f. (1988) il quaternario fra praja a mare e scalea (calabria settentrionale). atti 74° congr. soc. geol. it., settembre 1988, sorrento, pp. b 80-85. carboni m.g., malatesta a. & zarlenga f. (1988) il quaternario fra praja a mare e scalea (calabria settentrionale). mem. soc. geol. it., 41, pp. 645652. compagnoni b., jacobacci a., malatesta a. & valletta m. (1988) carta geologica d’italia alla scala 1:50.000. f. 373-cerveteri. serv. geol. d’it. malatesta a. & zarlenga f. (1988) evidence of middle pleistocene marine transgression along the mediterranean coast. palaeogeogr., palaeoclim., palaeoecol., 68, pp. 311-315. malatesta a. & willemsen g.f. (1988) algarolutra g.n., estabilshed for a fossil otter of the sardinia alberto malatesta geologist and palaeontologist 9 island. geol. rom., 25, pp. 285-286. caloi l., malatesta a. & palombo m.r. (1989) biogeografia della calabria meridionale durante il quaternario. atti acc. peloritana dei pericolanti, 67, pp. 261-278. gliozzi e., malatesta a., (1993) il quaternario marino e continentale del lazio. guida geologica regionale del lazio s.g.i., 5, pp. 74-77, ed be-ma, milano. gliozzi e., malatesta a., scalone e., (1993) revision of cervus elaphus siciliae pohlig, 1893, late pleistocene endemic deer of the siculomaltese district. geol. rom., 29, pp. 307-353. bono p., malatesta a. & zarlenga f. (1994) percorso 14. da velletri a san felice circeo. guida geologica regionale del lazio s.g.i., 5, pp. 322-343. malatesta a. & zarlenga f. (1994) nota aggiuntiva alla malacofauna pleistocenica della cava tacconi, nei pressi di pomezia (roma). il quaternario, 7, pp. 65-68. ms. ricevuto il 14/05/2010 testo definitivo ricevuto il 07/09/2010 ms. received: may 14, 2010 final text received: september 7, 2010 amq32(2) 131-150 bracchi et al.pub a resilient deep-water rhodolith bed off the egadi archipelago (mediterranean sea) and its actuopaleontological significance   valentina alice bracchi1 , lorenzo angeletti2, fabio marchese1, marco taviani2,3,4, frine cardone5, irka hajdas6, valentina grande2, mariacristina prampolini2, annalisa caragnano7, cesare corselli1, daniela basso1 1 department of environmental and earth sciences disat; conisma local research unit, university of milano-bicocca, italy. 2 institute of marine sciences, national research council (ismar-cnr), bologna, italy 3 stazione zoologica anton dohrn, napoli, italy. 4 biology department, woods hole oceanographic institution, ma 02543, usa. 5 department of biology, university of bari, italy. 6 laboratory of ion beam physics in zurich, eth zurich, switzerland. 7 department of life and environmental sciences disva, polytechnic university of marche, ancona, italy. corresponding author: v.a. bracchi <valentina.bracchi@unimib.it> abstract: rhodolith beds are priority marine benthic habitats for the european community, because of their relevance as biodiversity hotspots and their role in the carbonate budget. the high-mg calcite calcified thalli promote their preservation through time, resulting in their common occurrence in the fossil record, thus making rhodoliths a significant archive of past environmental and climate changes. the present temperate mediterranean sea is home to rhodolith-rich up to rhodolith-dominated habitats which have been targeted over the years for ecological research and management actions. furthermore, the mediterranean basin hosts an important fossil legacy of rhodolith beds that formed under contrasting climatic scenarios since the neogene. most examples of mediterranean rhodolith beds lay within the depth range (30-75 m), while far less is known about deeper occurrences. an outstanding rhodolith bed has been recently identified off the egadi archipelago (70-95 m, central mediterranean sea) in the frame of the italian marine strategy framework directive project. the rhodolith bed carpets an area >7 km2 between marettimo and favignana islands (egadi archipelago), with a cover of live rhodoliths up to 95%. the dominant rhodolith morphotype is pralines, ellipsoidal to discoidal in shape (average size 11 mm, maximum size 31 mm) associated with biogenic gravelly-sand. they present both seafloor bedforms (megaripples and ripples) and frequent bioturbations by epifaunal and semi-infaunal sea urchins. old algal nodules, biogenic sand/mud, or, less frequently, terrigenous particles serve as nucleus of individual rhodoliths. living calcareous algae are lithothamnion valens, l. cf. minervae, phymatolithon lenormandii, and lithothamnion spp. the latter characterize also the dead algal association close to the nucleus, with the subordinate presence of lithophyllum sp. benthic fauna corresponds to the circalittoral environment, with exclusive species of the coastal detritic biocoenosis or related to coarse sediments. moreover, the general textural aspects and bedforms are in line with moderate water energy at the seafloor. radiocarbon ages reveal that the cores of rhodoliths date back to 2334, 2159 and 1997 bp, which correspond to the roman warm period. calculated growth rate provides a very low figure (0.004 mm/yr). the inception of such rhodolith bed occurred under warmer climate conditions, but its development is continuing at present because of the persistence of adequate light conditions and bottom hydrological regime, with a very slow growth-rate. therefore, the egadi case history certifies a rare example of a deep-water resilient rhodolith bed, which should be taken into consideration for the potential recognition of fossil analogs in the mediterranean basin. keywords: rhodoliths, radiocarbon age, roman warm period, mediterranean sea, holocene.   available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 32 (2), 2019, 131 150 1. introduction calcareous coralline algae, slow-growing and longlived organisms, form rhodoliths that occur from the intertidal zone down to 270 m in the tropics (littler & littler, 1984), occurring commonly at tropical, temperate and polar latitudes on modern carbonate shelves worldwide from the intertidal zone down to 270 m (bosence, 1983a; littler & littler, 1984; nelson, 2009; teichert et al., 2012 foster et al., 2013). they display considerably resilience to varying environmental disturbances (bosence, 1983a, b; steller et al., 2003). rhodoliths boast an excellent fossil record and extant-type situations are well documented from the oligocene onwards (e.g., foster, 2001). rhodoliths often form aggregations named as rhodolith beds (rbs). since the 1990s, growing attention has been given to evaluate the rbs’ response to anthropogenic threats, such as physical damage due to fishing activities, aquaculture, or degradation of water quality (massutti et al., 1996; borg et al., 1999; bordehore et al., 2000, 2003; relini & giaccone, 2009; sanzlázaro et al., 2011; teichert, 2014; ordines et al., 2017). the identification of rbs, their areal distribution and vitality, their main features bioengineers, are all fundamental topics for a sustainable management of https://doi.org/10.26382/amq.2019.09 132 bracchi v.a. et al. marine environment. mediterranean rbs are considered as marine benthic habitat of high conservation interest, and two of the main species structuring this habitat, phymatolithon calcareum (pallas) areschoug (1852) and lithothamnion corallioides (p.crouan & h.crouan) p.crouan & h.crouan 1867, are included in the european community habitat and species directive 92/43/eec annex v. they are subjected to a special plan for the protection within the framework of the united nations program’s mediterranean action plan (unep map rac/ spa, 2008) and one of the marine habitat included in the monitoring program in the marine strategy framework directive 2008/56/ec of european community. in the mediterranean sea, live rbs are scattered in infralittoral environments but mostly occur in circalittoral detritic bottoms (basso et al., 2017 with references therein). they may occur between 9 and 150 m (balearic sea, aguilar et al., 2009), typically within a depth range of 30-75 m (basso et al., 2017). they are presently located around islands and capes, on top of submarine plateaux, seamounts, marine terraces, channels and banks (basso et al., 2017 with references therein). because of their complexity, architecture, and three-dimensional structure hosting abundant flora and fauna rbs represent a hotspot of biodiversity (basso et al., 2016; riosmena-rodríguez, 2017). due to the carbonate composition of their cell walls (mg-calcite), calcareous algae and consequently rbs play a key-role in the carbonate budget cycle, epitomizing a nonrenewable resource because of the slow growth rate and related carbonate deposition (<1 mm/yr, canals & ballesteros, 1997; martin & gattuso, 2009; basso, 2012). as for most top calcifiers, there is some concern about the fate of calcareous algae with respect to the on-going and future climate changes, and especially ocean acidification (andersson et al., 2008; nelson, 2009; martin & gattuso, 2009; gao & zheng, 2010; teichert et al., 2012; mccoy & regazzola, 2014; williamson et al., 2014; nash et al., 2015). rhodoliths can develop without any type of nucleus, or around skeletal or non-skeletal nuclei, usually producing a more or less concentric arrangement of the algal thalli. calcareous algae show a wide variety of growth form, from foliose to fruticose to lumpy (bosence, 1983b), depending from many factors that regulate their growth and distribution (main ones: water depth, light, hydrodynamics and sedimentation regime) (wilson et al., 2004; basso et al., 2009; teichert et al., 2012; sañé et al., 2016). the same is true for rhodolith shape, that can range among ellipsoidal, discoidal, and spheroidal (bosence, 1983b; basso, 1998). commonly, rhodolith survival depends on overturning and consequently on tab. 1 a summary of available literature facing with the relation between rhodolith outer/inner structure and water energy/water depth. 133 deep resilient rhodolith bed of egadi archipelago the possibility to be continuing their accretion by avoiding overgrowing by other organisms and smothering. moreover, rhodoliths are sensitive to burial (bordehore et al., 2002, 2003; biomaerl team 2003; riul et al., 2008; bahia et al., 2010) and increasing nutrient and organic carbon are determined to their development (sanz-lázaro et al., 2011). therefore, water motion is needed to maintain the rhodoliths unburied and in meso -oligotrophic conditions (marrack, 1999; steller et al., 2003), and actually, rhodoliths are often associated with sedimentary structures related to water motion such as ripplemarks and dunes (barberá et al., 2012; micallef et al., 2012; sañé et al., 2016). based upon tank experiments, basso and tomaselli (1994) calculated the relationship linking rhodolith shape and density with the current velocity needed to displace them, and provided evidence that storms may occasionally move rhodoliths down to >50 m depth. on the contrary, marrack (1999), suggested that the bioturbation is fundamentally responsible for the overturning of rhodoliths and their survival in deep environment. the relation between rhodolith outer/inner structure and water energy/water depth is debated in literature (tab. 1) and no straightforward interpretation can be drawn from them. nevertheless, this relation has been considered as a reliable tool for paleoenvironmental interpretation (bosence & pedley, 1982; braga & martin, 1988; aguirre et al., 1993; bassi, 1995, 2005; bassi & nebelsick, 2010). since the neogene, rbs are recurrent components of mediterranean carbonate shelves and frequent in shallow-water mixed siliciclastic deposits (halfar & mutti, 2005; braga et al., 2010). they present an uneven stratigraphic distribution through time, with a maximum positive peak at the middle miocene climate optimum (halfar & mutti, 2005), and a decrease since the pliocene (braga, 2017; coletti et al., 2017 with references therein). this assumption should be considered with caution since potentially reflecting a relative paucity of suitable carbonate outcrops of plio-pleistocene age. due to carbonate structure, worldwide distribution, and occurrence in the fossil record, rbs represent a highly significant archive of past and present climate changes. prager (1987) highlighted that taxonomic changes form the nucleus to the outer surface of a rhodolith might due to physical or biotic changes through time, but they cannot be related to ecological succession (basso et al., 2009). basso & tomaselli (1994) and basso et al. (1998) suggested that the analysis of changes in the growth forms of calcareous algae, as well as in the taxonomic composition from the nucleus to the surface of a rhodolith, could provide valuable information of paleoenvironmental shifts, a hypothesis later supported by aguirre et al. (2017). this paper discusses a new deep-water mediterranean rhodolith bed (rb) discovered off marettimo island (egadi archipelago, mediterranean sea). the main characteristics of this live rb are discussed in term of morphology, ecology, taxonomy and temporal evolution from the late holocene to present. the final goal of this study is to provide a suitable modern analog of a peculiar mesophotic habitat to assist the paleontological reconstruction in the mediterranean neogene record. 2. material and methods a seabed sector between marettimo and favignana islands (egadi archipelago, mediterranean sea) (fig. 1), has been investigated in the framework of italian marine strategy framework directive (directive 2008/56/ec, 2008) project, during the strategia marina ligure-tirreno oceanographic cruise (25 july 5 august 2016) on board the r/v minerva uno. 2.1 study area marettimo island belongs to the egadi archipelago (southern italy) (fig. 1a, b), placed in the westernmost sector of the sicilian-maghrebian chain (catalano et al., 1996). marettimo island is isolated from the rest of the egadi islands by a channel. this channel is a long submarine valley (24 km), nnw-sse oriented, with a depth ranging from 180 m up to 370 m and a width from 2 km up to 14 km (polizzi et al., 2011). it has an important role in the water exchanges between the sicily channel and the southern tyrrhenian sea (miller, 1972; manzella et al., 1988). its morphology reveals the occurrence of strong bottom currents probably related to the severe interchange of water masses between the tyrrhenian sea and the sicily channel (polizzi et al., 2011). the western sicily continental shelf is small, with an average area of 200 km2 and a maximum width of 40 km (agate et al., 1999). due to the reduced sedimentary supply from coastal erosion and river input, the holocene sedimentary prism is very thin or absent around the marettimo inner shelf compared to the usual values observed on the sicilian shelf (colantoni et al., 1993; agate et al., 1998). sediments are constituted by heterogeneous mixtures of pebbles and gravels with medium to coarse sands in the inner shelf, turning to mud mixed with lithoclastic grains that overlies coarser sediments on the outer shelf (lo iacono, 2004). during the late holocene highstand phase, the isolation from mainland sedimentary inputs and the reworking of sediments favored the limited preservation of fine sediment and the dominance of pebbles, gravels, and coarse sands on the shelf (colantoni et al., 1993; hermand et al., 1999). seafloor presents sedimentary structures formed by bottom currents. lo iacono & guillén (2008) described an extensive field of submarine dunes (ashley, 1990) and sorted bedforms along the marettimo inner shelf (10-50 m), forming on gravelly and pebbly sediments and related to strong storm events. in the se sector of the marettimo outer shelf, colantoni et al. (1993) and lo iacono (2004) recognized two-dimensional dunes at depths between 60 and 90 m with a wavelength variable between 15 and 50 m, and three-dimensional dunes at a depth of 80 m characterized by a wavelength of 30 m and a lateral extent of 50 m. 2.2 remote data remote data have been collected using a multibeam echosounder (reson seabat 7160) (fig. 1c). bathymetric dataset has been processed using dedicated software (pds2000 and caris hips&sips) to produce a 5 m resolution digital terrain model (dtm) and a 5 m resolution backscatter mosaic of the seafloor. 2.3 rov dive and lander station seafloor bathymetry data have been groundtruthed by remote operated vehicle (rov pollux iii of stella maris s.r.l.) (fig. 1c). rov is equipped with lowresolution ccd video camera for navigation and general description, and high-resolution (2034x1296 pixels) video camera (sony hdr-hc7) for detailed description. three laser beams at distance of 20 cm each other, provided the scale bar on the videos. positioning is guaranteed by an acoustic position system, which provided the exact geographical and depth position every second. dive ms16-197 is ca. 1 km long, about e-w oriented (fig. 1c), between 74.4 and 86.8 m water depth. rov has been used to detect the occurrence of rhodoliths, the major geomorphological and sedimentological features, bioturbations, and associated megafauna. on the video, all the organisms larger than 2 cm have been identified at the lowest possible taxonomic level. taxonomic identification follows the world register of marine species (worms editorial board, 2019). video has been analyzed with adelie video and adelie gis based on arcmap® geographic information system (distributed by esri). the minifilms tool has been used to extract high-resolution images from rov footage every 10 seconds: 540 photographs have been obtained with each image covering ca. 6 m2. a total length of 1005.4 m, and for more than 6.000 m2 of seafloor (buffer area 6 m large), has been surveyed during the dive. frames have been used to describe dominant rhodolith morphotypes and live cover. a rb is an area of soft substrate with a cover of more than 10% of living rhodoliths (steller et al., 2003; basso et al., 2015). moreover, the rbs may be mosaicking with other types of bottoms. two adjacent rbs are considered separate if, 134 fig. 1 geographical framework of the study area. a) bathymetric map of the mediterranean sea, red star indicates the location of the egadi archipelago. b) geographical setting of the egadi archipelago. c) location of the surveyed area: grey polygon localizes the multibeam coverage. red cross and black dots indicate respectively the position of the lander deployment and the grab samples. violet line specifies the rov navigation track. bathymetry and isobaths from emodnet bathymetric consortium (2018). bracchi v.a. et al. at any point along their limits, a minimum distance of 200 m separates them (peña and barbara, 2008; basso et al., 2016). rb extension (i.e. cartography) results from the integration of direct and indirect observations. a benthic lander station for the measuring of temperature, salinity and currents on the rb has been deployed in the site ms16-199 (37°57’3” 1 n, 12°7’13” e, 86.8 m) for almost 5 hours of continuos recording (fig. 1c). 2.4 seabed sampling where rov images showed the highest rhodoliths cover, the ms16-200/201/202 (three replicas at the same station, 37°57’0 n, 12°7’13” e, 86.5 m) (fig. 1c) have been collected using a modified van veen grab (volume =60 l) following basso et al. (2016). immediately after collection, three sub-samples of 200 g have been recovered for grain-size analysis. live rhodoliths have been picked up and photographed onboard. according to steneck (1986), the nodule is classified as rhodolith when more than 50% of their total volume is made of calcareous algae; otherwise, it is indicated as a coated grain. however, for monitoring, it has been suggested to consider as rhodoliths all those nodules showing a complete algal coating, with no need to cut them for checking the thickness of the algal coating in respect of the rhodolith nucleus (basso et al., 2016). rhodoliths have been classified based on their morphology (bw=boxwork, pr= praline or br= branches) according to basso (1998; 2012) plotting the results in a ternary diagram. rhodolith shape has been described following bosence (1983b) by measuring the long (a), intermediate (b) and short (c) axes of all rhodoliths (n = 250), and applying the maximum projection sphericity formula the results have been plotted in sneed and folk’s (1958) pebble shape diagram using origin software. size of all rhodoliths was measured using the volume of an ellipsoid as indicated in bosence (1976), and the results are reported in a box plot. algal growth-form follows woelkerling et al. (1993). selected sub-sample of live encrusting calcareous algae have been manually detached from the surface of live rhodoliths and treated for species identification, using the scanning electron microscope (sem), and petrological thin sections. moreover, twenty rhodoliths have been sliced to investigate 1) nucleus type, 2) potential changes in algal association close at the nucleus. the identification of non-geniculate red algae follows the biological systematics framed by woelkerling (1988), as revised by several subsequent contributions (irvine & chamberlain, 1994; bressan & babbini, 2003), and adapted to paleontology (basso, 1994, 1995; braga, 2003; bressan et al., 2003; hrabovský et al., 2015). algal taxonomy follows algaebase (guiry & guiry, 2019). 135 following basso & corselli (2007), mollusk shells have been picked from the gravel fraction and analyzed in order to describe the associated thanatocoenosis, interpreted in the framework of the marine bionomy (pérès & picard, 1964; pérès, 1982; bellan-santini et al., 1994). finally, three rhodoliths have been dated using the ams radiocarbon technique dating at the laboratory of ion beam physics in the eth of zurich (ch). each rhodolith has been firstly broken, and then 14c dating has been conducted on both the outer part of each rhodolith, and closest part to the nucleus, selecting the first calcareous algae carbonate layers directly encrusted on the nucleus and then its outermost layer. the resulting time interval between the two dates has been divided per the algal thickness to obtain the growth rate of the rhodolith. radiocarbon ages of the carbonate fraction of the three rhodoliths were calibrated with either oxcal 4.3.2 (ramsey, 2009) and marine calibration curve (marine intcal13, raimer et al., 2013) or data set of hammer & levin (2017) using calibomb after the 14c age was corrected for the mean reservoir age of the ocean (400 14c yrs), which is an approximation of the values in the region (siani et al., 2000). 3. results 3.1 remote survey, rov and lander station the investigated area covered 22.7 km2, from 55 to 350 m, a portion of the marettimo shelf and upper slope on the western side of the channel between marettimo and favignana islands (egadi archipelago) (figs. 1c, 2a, b). the shelf is a ne-oriented gentle slope with an average gradient of 0.5°, and a maximum of 2.5° in the central part, at depths ranging between 65 and 85 m (fig. 2a). an isolated rocky structure characterizes the ne sector on the outer shelf (fig. 2a). backscatter response associated with rb is a composite texture of bands of high and low backscatter signal (fig. 2b-c), and this is consistent with the main features observed in the video record where living rhodoliths are mosaicked with mobile biogenic sediments, mainly sand and gravel (fig. 3a) possibly corresponding to the observed bedforms. the live algal cover is not homogeneous across the bed. highest backscatter corresponds to an area where live rhodoliths are present, and the live cover is up to 95% (figs. 2b-c, 3a-b). low backscatter corresponds to seafloor where live rhodolith coverage is limited, less than 10% and corresponding to the patches of sediments observable on rov (fig. 2b-c). based upon these observations, we contoured an area of 7.18 km2 (fig. 2d), se of marettimo island and extended toward favignana island covered by live rhodoliths. the thickness of the live rhodolith layer corresponds to the dimension of a single rhodolith, therefore not exceeding 3.4 cm (fig. 3b), that is to say that live rhodoliths occur as a single layer. rov images documented features characterized by large wavelength and thickness < 10 cm, interpretable as megaripples, complemented by smaller ripple-like features among on rhodolith (fig. 3c). such bedforms deep resilient rhodolith bed of egadi archipelago are consistent with vigorous bottom currents, whose measured intensity was 0.09 m/s and 306°n at the time of our survey (angeletti et al., 2017). intense sediment reworking by echinoderms is macroscopically obvious (fig. 3e-f) as trails ascribable to foraging (ichnologically fodinichnia) and walking activity (ichnologically repichnia) by the semi-infaunal spatangus purpureus (fig. 3f). regarding physical attributes of the water column near the seabottom, we measured a temperature of 15.07° and a salinity of 38.18‰ (angeletti et al., 2017). although irradiance has not been measured instrumentally, its natural decline at the seafloor was appreciated by the rov (fig. 3g-h). 3.1.1 megafauna megafauna identified through rov video analysis comprehends 15 species belonging to five phyla (cnidaria, mollusca, echinodermata, arthropoda and chordata (tab. 2). in the rhodolith/mixed sediment, we spotted the presence of two pennatulaceans pennatula rubra and ptereoides spinosum (fig. 4a-b), more often associated with muddy seabottom (e.g., chimienti et al., 2018a, b). one individual of the anemone peachia cylindrica (fig. 4c) and one colony of the alcyonacean nidalia studeri (fig. 4a) were also detected. identified mollusks include a cluster of the oyster neopycnodonte cochlear (fig. 4d), the filter-feeder scallop cf. aequipecten opercularis (fig. 4c) and the cnidarianectoparasitic gastropod acirsa subdecussata at the base of the p. spinosum (fig. 4b). in terms of abundance, echinoids predominate (figs. 3a, e-f; 4a, c, e-f) with the dominance of stylocidaris affinis (663 individuals) and s. purpureus (55 individuals). aggregations of the grazing echinoid s. affinis (figs. 3a, 4e), were imaged atop rhodoliths whilst presumably feeding upon the algae. noticeably, the decapod inachus dorsettensis settled over a s. purpureus, possibly taking advantage of the digested sediment (fig. 4f). observed fishes were a juvenile serranus cabrilla and chelidonichthys cf. lastoviza. 3.2 seabed samples the study area is characterized by rhodoliths (gravel to pebble fraction) laying on, or mosaicking with biogenic gravelly sand (fig. 3a-d-g). main morphotype is pr (fig. 5) with medium size of long axis of 1.1 cm and max 3.4 cm (fig. 5f-g). sneed and folk’s (1958) pebble shape diagram showed a majority of ellipsoidal to discoidal shapes (fig. 5e). the size range is between 0.3 and 1.8 cm (fig. 5f-g). rhodoliths are multispecific, with an encrusting-warty concentric and regular development around the nucleus and no protuberance on the surface 136 <<< ---- fig. 2 acoustics dataset resulting from multibeam data processing: a) bathymetric map of the surveyed area. b) backscatter photomosaic of the surveyed area with c) magnification that shows the composite texture of high and low signal bands associated with rb. d) red polygon on the backscatter model indicates the mapping of rb distribution in the area. bracchi v.a. et al. 137 fig. 3 some of the main features of the studied rb. a) area with high coverage of living rb with stylocidaris affinis (s). b) a detail of living rhodoliths with the indication of a =arca tetragona; b =bivalve entirely covered by calcareous algae; e =juvenile dead specimen of s. affinis. c) ripples (white arrows) identified on biogenic gravelly sand mosaicking live rhodoliths. d) the complex pattern of seabed forms and bioturbation traces by spatangus purpureus. e) motion traces of s. purpureus. f) s. purpureus partially digging into sediments. g-h) direct irradiance measurement during the ms16-197 rov dive (02/08/2016, 9:30 am): the light have been turn on (g) and off (h) in the same area to test the natural lighting on the seafloor. deep resilient rhodolith bed of egadi archipelago 138 fig. 4 megafauna observed during the rov ms16-197 dive on the studied rb. a) pennatula rubra inhabiting coarse biogenic sediment, white arrow marks the alcyonacean nidalia studeri, note the echinoderms spatangus purpureus and stylocidaris affinis in the background.. b) a specimen of the relatively abundant ptereoides spinosum here parasitized by the cnidarian-ectoparasite arcisa subdecussata (arrow). c) medium-coarse biogenic sediment characterized by the s. affinis in the foreground, the sea anemone peachia cylindrica (white arrow) and the scallop cf. aequipecten opercularis (black arrow). d) cluster of the oyster neopycnodonte cochlear. e) aggregation of st. affinis feeding on living red algae. f) the decapod inachus dorsettensis (white arrow) settled over the common echinoderm s. purpureus possibly feeding digested sediment (black arrow). tab. 2 list of the megafauna associated with the studied rb. bracchi v.a. et al. (fig.5a-d). the nucleus of 20 rhodoliths was formed by old calcareous nodules (n =11) (fig. 5d), biogenic sandmud (n =7) (fig. 5c), and terrigenous fragments (n =2). the inner structure resulted very compact (figs. 5c-d, 6a-b), with dominance of encrusting calcareous algae, very few voids or obvious evidence of bio-erosion, with the exception of one sample showing also encrusting bryozoans. the calcareous nodules at the nucleus are easily distinctive because of their porous structure, a poor conservation status with bio-erosion traces, and a yellowish to dark gray color (fig. 5d). sem confirms that the inners structure is highly compact (fig. 6a, b). identified calcareous algae species of the external live cover are, in order of abundance, lithothamnion spp. (fig. 6ce), neogoniolithon brassica-florida (harvey) setchell & l.r.mason 1943 (fig. 6f), lithothamnion cf. minervae basso 1995 (fig. 6d), lithothamnion valens foslie (1909) and phymatolithon lenormandii (areschoug) w.h.adey 1966. the algal association close to the nuclei contains once again lithothamnion spp., and very rare lithophyllum sp. 3.2.1 mollusk thanatocoenosis a total of 74 species among bivalves and gastropods have been identified at the species level (fig. 3). conservative index (tab. 3) corresponds often to 3 or 4, therefore the thanatocoenosis can be considered as autochthons. the mollusk thanatocoenosis is by large enriched (n =20) in shells indicative of species inhabiting coarse mobile bottoms (pss, gravel, shelly bottom, stone) (tab. 3). numerous taxa (n =11) are typically distributed in the 139 fig. 5 detail on collected rhodoliths and graphic analyses of their morphology, shape and size. a) collected rhodoliths from sample ms16 -201. b) a detail of live rhodoliths collected from sample ms16-201; c-d) rhodoliths with nucleus of c) biogenic sand/mud or d) old algal nodule. red dotted contours indicate the nucleus. stars indicate the point of picking of material for the ams dating: black for inner samples, light blue for outer samples. e) ternary plot of the main morphotypes. yellow star = ms16-200, green star = ms16-201, red star = ms16-202. bw=boxwork, pr=pralines, br=branches. f) ternary plot of the shape based on measurements of long (a), intermediate (b) and short (c) axes as described in sneed and folk (1958). black crosses indicates all the measured rhodoliths. g) box plot showing size range of rhodoliths based on measurements using the volume of an ellipsoid as described in bosence (1976). deep resilient rhodolith bed of egadi archipelago 140 bracchi v.a. et al. circalittoral zone, mostly linked to coastal detritic (dc), coralligenous (c), muddy coastal detritic (dl), and deep mud (vp) biocoenoses (pérès & picard, 1964; pérès, 1982). among them: exclusive dc turritella triplicata, melanella polita; preferential dc: arca tetragona; preferential c muricopsis cristata; c: marshallora adversa, cerithiopsis turbercularis; exclusive dl astarte sulcata; exclusive vp: limatula subauriculata(tab. 3). rare occurrences reports of species linked to strictly infralittoral biocoenoses are recorded (ap: pusia savignyi; ap/hp: calliostoma cf. laugieri) with respectively only one and three specimens. bittium reticulatum, reported as indicative of ap/hp, although abundant, has to be considered a species with a large ecological distribution, so less significative. 3.4 ams 14c dating three selected rhodoliths gave six reliable data (tab. 4). ages of the inner part range between 2334 bp (ms16-201-17i) and 1997 bp (ms16-201-15i). ages at the surface of rhodoliths (outer) range between 101 bp (ms16-201-17o) and modern (ms16-201-15o). the thickness of algal thalli from the nucleus to the outer surface is at least 1 cm (fig. 5 c-d) therefore, calculated growth-rate corresponds to 0.004 mm/yr. 4. discussion the present study focused upon an area of ca. 7 km2 (fig. 2d), in the egadi archipelago, around the southeastern part of marettimo island. live rhodoliths spread on such area achieving a live cover up to 95% in a bathymetric interval between 70-95 m (circalittoral zone) (figs. 3, 5). following steller et al. (2003), this habitat can be conveniently referred to as ‘rb’. high cover of live rhodoliths alternates with patches of biogenic gravelly sand characterized by sparse live rhodoliths (<10%) (fig. 3c). these patches display a lateral continuity <200 m, therefore this habitat is as a whole and single rb (peña & barbara, 2008) (fig. 2d). the marettimo rb compares well with analog situations in other sites of the mediterranean sea, although it is deeper than the usual bathymetric range of 30-75 m (basso et al., 2017). within the coastal detritic biocoenosis (pérès & picard, 1964; pérès, 1982), the pralines facies has been described as developing on a mixed substrate of biogenic sand and gravel hosting an invertebrate association characteristic of several other circalittoral biocoenoses. our data corresponds to the pralines facies of pérès and picard (1964), although the external morphology of our rhodoliths is encrusting and not protuberant (fig. 5a), contrarily to those originally described by the authors, and later confirmed by others (among others: basso, 1998; toscano et al., 2006; sciberras et al., 2009; sañé et al., 2016). 4.1 bottom currents and sedimentary structures associated to marettimo rb the backscatter signal appeared distinctly high at the occurrence of rhodoliths (fig. 2b-c). it is consistently associated with continuous live beds (bracchi et al., 2011; micallef et al., 2012; savini et al., 2012; sañé et al., 2016). moreover, identified backscatter texture (alternated bands of high and low backscatter) (fig. 2c) corresponds to the occurrence of megaripples on the seafloor, as observed on rov video suggesting the occurrence of under bottom currents. in the mediterranean sea, offshore sandy-gravelly dunes have been observed in deeper areas (150-300 m) of the aegean sea and in the messina strait (sicily) (lykousis, 2001; santoro et al., 2002). such dunes have been related to strong current flows caused by water mass circulation or local tides (lykousis, 2001; santoro et al., 2002). lo iacono & guillén (2008) have described coarse (gravelly and pebbly) dunes and sorted bedforms on the inner continental shelf of marettimo island. these last have been reported se of marettimo island, in an area characterized by the same backscatter texture (high and low bands), but shallower, between 10 and 50 m of water deep, on a shelf with slope value of 2.5° degree. they interpreted them as the result of the effect of along-shelf current as described in other sites (murray & thieler, 2004; coco et al., 2007). current velocity required for the entrainment of coarse sediments as the ones collected in the studied area, se of marettimo island, corresponds to a nearbottom mean-current of ca. 0.8 m/s on the nw, as calculated for mediterranean continental shelf during strong storms (palanques et al., 2002; guillén et al., 2006). according to the bedform-existence diagram (d50 vs mean current velocity) defined by southard and boguchwal (1990) and applied by lo iacono and guillén (2008) on the marettimo shelf sediments, a current of at least 0.4 m/s is required for the entrainment of sand-gravel, a grain fraction that corresponds to the sediments associated with live rhodoliths. moreover, we have to consider the occurrence also of rhodoliths (pebble-sized): consequently, the needed velocity ranges between 0.4 and 1 m/s. unfortunately, we collected measures of the bottom currents (0.09 m/s), only for few hours, and this value does not justify the occurrence of megaripples that we have observed by rov analysis. further measurements will detail better the hydrodynamic regime of the area and explain the occurrence of such bedforms. 141 <<<<< fig. 6 sem images of the inner structure of rhodolith and some examples of the diagnostic characters for the identified calcareous algae species: a-b) the inner compact structure of rhodoliths, with superimposed layers of algal thalli, and no evident signs of bioerosion; c) tetrasporangial conceptacles, lithothamnion sp.; d) epithallial flared cells in longitudinal section, lithothamnion cf minervae; e) epithallial flared cells in surface view, lithothamnion sp.; f) epithallial cells in surficial view: rosette cells with the opening of the porocanal of a multiporate conceptacle, lithothamnion valens; g) uniporate conceptacle, neogoniolithon brassica-florida. deep resilient rhodolith bed of egadi archipelago 142 bracchi v.a. et al. 4.2 bottom currents and rhodolith morphotypes bottom currents are considered as one of the most important variables governing rhodolith occurrence and development (tab. 1). moderate energy has been identified as the best condition (ryan et al., 2007) although there is no consensus. the marettimo bed contains very small pralines, ellipsoidal to discoidal, without protuberances, and with a very high live cover of the seafloor. the inner structure revealed that encrusting calcareous algae dominated the framework, and they developed encrusting-warty, concentric, very compact structure, with few voids. therefore, we can assess that moderate current energy is present, although the main rhodolith features do not fit the models reported in table 1. the modern maerl bed of the maltese archipelago (sciberras et al., 2003), especially in terms of rhodolith morphotype, represents a similar setting although pralines are never dominant and occur at shallower depths. in term of size, the studied rhodoliths are very small as expected following some authors (tab. 1). 4.3 rhodolith growth-rate and the inception of marettimo rb since calcareous algae growth-rate is typically very low (up to 1 mm/yr; sartoretto et al., 1996; canals & ballesteros, 1997; martin & gattuso, 2009; basso, 2012), the formation of rbs may imply a long time. steller et al. (2009) estimated that a rhodolith 3-8 cm in diameter in the gulf of california would remain on the seabed from years to decades. our live rhodoliths represent only the surficial veneer of present-day seafloor, with a thickness of maximum 3.4 cm. ams dating demonstrated that they started to develop between 2334 bp and 1997 bp (tab. 4). therefore, depth and sedimentary regime at the inception stage of rb formation is assumed to have been the same as the present. we may hypothesize that the generally warmer condition under the roman climate optimum somehow favored the development of calcareous algae. in this respect, warmer periods correspond to calcareous algae spread since the neogene (halfar & mutti, 2005). the growth-rate of 0.004 mm/yr is a mean value obtained by combining ams dating and the rhodolith thickness. this rate is consistent with data reported in the pertinent literature (sartoretto et al., 1996; canals & ballesteros, 1997; martin & gattuso, 2009; basso, 2012). interestingly, it corresponds to less than one layer of cells per year. considering that a one-cell layer is the minimum discrete unit of thickening, the implication is that the growth of encrusting algae is not continuous during time. despite this low value, the inner structure is very dense and macroscopically voidless, with superimposed layers of calcareous algae. sediment associated with rhodoliths is only gravelly sand. all these features are consistent and suggest that the marettimo bed developed under bottom current responsible for their periodical overturning and maintenance in life by preserving from burial and fouling by encrusting organisms as bryozoans. moreover, the water transparency and the absence of turbidity may favor calcareous algae that resist under such oligophotic conditions, with respect to other common organisms in such deep environment (i.e. bryozoans). the combined evidence concurs in the interpretation of the marettimo case study as an example of a resilient habitat at the millennial temporal scale. 4.4 the inner structure of marettimo rhodoliths the inner core of the rhodoliths is prevalently bioclastic, with a predominance of old algal nodules as nuclei. other nuclei, such as terrigenous particles, are far less common. similar reports, with more than one generation of algal framework, have been found in the rhodoliths of 1) the peregrino oil field in the campos basin (brazil) at approximately 100 m water deep (tâmega et al., 2014), 2) the pliocene of cabo de rocha (sw spain) (aguirre et al., 1993; aguirre & braga, 143 <<<<< tab. 3 list of identified mollusks in the studied samples. a is for abundance, c for conservation status sensu basso and corselli (2007). ecology: infra = infralittoral zone, circa = circalittoral zone, exl = exclusive, pref = preferential, ap = photophylous algae biocoenosis; hp = posidonia meadow biocoenosis, c = coralligenous biocoenosis; dc = costal detritic biocoenosis, dl = muddy costal detritic biocoenosis, vp = deep mud biocoenosis, pss = small solid substrate, lre = large ecological distribution ; sspr = without a specific ecological indication; misto = mistophylous. tab. 4 results of ams radiocarbon dating. sample code describes the position of sampling: i (inside) or o (outside) indicates the sampling point respectively from the surface or close to the nucleus. the correction for reservoir age is 400 14c years. deep resilient rhodolith bed of egadi archipelago 2012), and 3) the miocene of southern apennines (checconi et al., 2010). further investigations will focus on this polyphasic aspect. in the studied rhodoliths, the form of old algal nodules drove the resulting shape. in other cases, nucleus is formed by biogenic sand and mud entrapped by encrusting calcareous algae. we can imagine that encrusting laminar thalli started developing, and, overturned by currents/benthic fauna, developed in various directions, up to entrapping material. therefore, the developing of the calcareous algae themselves built the nucleus. we did not identify a change in the bioengineers, with lithothamnion spp. dominating both the external and the internal framework. lithothamnion heydrich, 1897, is commonly recognized as a typical deep-water genus (adey & adey, 1973; henriques et al., 2012; aguirre et al., 2017), and its dominance in the rb under scrutiny is consistent with the bathymetric interval. 4.5 marettimo rhodolith and associated megafauna rb situations are known to foster high biodiversity levels (e.g., cabioch, 1969; freiwald & henrich, 1994; teichert, 2014; riosmena-rodríguez, 2017) and to be habitat to a variety of epifaunal and infaunal organisms, many of which skeletonized and, therefore, capable to contribute durable particles to sediments. our reports confirm the high biodiversity associated to the occurrence of a rb. moreover, echinoids (s. affinis and s. purpureus) are really abundant (tab. 2) and they are responsible of intensive reworking of sediments and rhodoliths (fig. 3 d-e-f), thus confirming that bioturbation is fundamental for the overturning of rhodoliths and their survival in deep environment (marrack, 1999). among skeletonized organisms, mollusks are one component commonly associated with these rhodalgal situations (e.g., freiwald & henrich, 1994; basso & brusoni, 2004; jackson et al., 2004; castriota et al., 2005; sciberras et al., 2009), and, in fact, the prevalently biogenic sediment type at the study site contains a substantial mollusk skeletal fraction. because of their abundance, relative geological durability and ecological value (cf. pérès & picard, 1964; pérès, 1982), we examined the taxonomic composition of the sediment and results are reported in table 3. the thanatocoenosis contains taxa reflecting the ecological heterogeneity of the seabottom. in fact, the fauna appears by large enriched in species (e.g., emarginula rosea, jujubinus montagui, homalopoma sanguineum, t. triplicata, a. tetragona, gonilia calliglypta) consistent with circalittoral coarse sediment and detritic bottoms (including rbs) which predominate at the site, plus many others likely derived from coralligenous (e.g., m. cristata, murexsul aradasii), and muddy/mixed situations. 4.6 marettimo rb and irradiance penetration of sunlight (irradiance) and its attenuation is a major forcer governing photosynthesis and the consequent macroalgal growth (saulquin et al., 2013). calcareous algae are able to develop in dim-light conditions (ballesteros, 2006). although not quantified at this stage, the persistence of a sufficient sunlight illumination on the bottom at the study site has been qualitatively ascertained by the rov. given the taxonomic uniformity observable on the rb, such light conditions prevailed at the site throughout the holocene time span recorded by the rhodoliths. the prime value of the habitat recognized at the egadi archipelago stays with its peculiarity to be a rare example of deep-water rb formed under a very low irradiance extending down to the edge of the mesophotic zone. it responds to a peculiar ecological situation on the seabed, likely to be met in areas characterized by a lack of or extremely reduced turbidity that would affect the penetration of sunlight deep in the water column. this may imply the existence of oligotrophic conditions in the water column and minimal terrigenous input. such paleo-conditions may favor the development of calcareous algae and consequently rhodoliths that makes this recent case study a potential clue to better interpret past situations in the geological record from the miocene onwards. with respect to the fossil legacy, several outcrops enriched in calcareous algae are, in fact, known since the neogene, some of which interpretable as rbs. most published data reveal, however, differences with the deep-water rb here presented in terms of general context and rhodolith morphologies. for instance, coletti et al. (2016) found small pralines dominated by lithothamnion spp., but the hosting context excludes that they represent a deep-water situation. yet, many plio-pleistocene assemblages enriched in rhodoliths might indeed have been formed under deep-water conditions, but have been insufficiently studied thus far.the egadi archipelago case history may therefore serve as a diagnostic model because of its distinctive characteristics. 5. conclusion a deep-water rb has been mapped between 70 and 95 m se of marettimo island (egadi archipelago, mediterranean sea). live rhodoliths cover the seafloor, mosaicking with sand-gravel biogenic-dominate sediments and sculpturing megaripples. rhodoliths are very small pralines (up to 3.4 cm), ellipsoidal to discoidal, lithothamnion spp. dominate the assemblage, with very compact structure and partially polyphasic. the rb is bionomically compatible with the circalittoral zone, although the detailed study of rhodoliths reveal distinctive and unexpected elements (shape, dimension, growthrate), which makes this rb an exception with respect to rhodolith descriptive models available in literature. moderate energy at the seafloor, oligophotic condition and enough irradiance maintains in life such rb, and calcareous algae overall other organisms, since the roman climate optimum, dated as the age of its inception. the marettimo rb might serve as a modern model to assist the identification of similar facies of the mediterranean neogene deposits. acknowledgements this is a scientific contribution of project miur dipartimenti di eccellenza 2018-2022 and ismarbologna scientific contribution n. 1991 and is part of convenzione mattm-cnr per i programmi di monitoraggio per la direttiva sulla strategia marina (msfd, art. 144 bracchi v.a. et al. 11, dir. 2008/56/ce). captain, crew and scientific staff of rv minerva uno cruise strategia marina ligure-tirreno are acknowledged for their efficient and skillful cooperation at sea. v.a.b. and f.m. are funded by a post-doc fellowship in earth sciences of the milano -bicocca university. references adey w.h., adey p.j. (1973) studies on the biosystematics and ecology of the epilithic crustose corallinaceae of the british isles. european journal of phycology, 8, 343-407. adey w.h., macintyre i.g. (1973) crustose coralline algae: a re-evaluation in the geological sciences. geological society of american bulletin, 84, 883904. agate m., d’argenio a., di maio d., lo iacono c., lucido m., mancuso m., scannavino m. (1998) la dinamica sedimentaria dell’offshore della sicilia nord-occidentale durante il tardo quaternario. atti del 79 congresso nazionale della società geologica italiana, palermo, italia, guida alle escursioni, 1, 157-167. agate m., borruso a., d’argenio a., lo iacono c., mancus, m., scannavino m., hermand j.p., michelozzi e., stefanon a. (1999) using high resolution seismic and coring data for environmental coastal studies. the case of marettimo island, italy. in: science-technology synergy for research in marine environment: challenges for the xxi century, international school of geophysics, erice, sicily. aguilar r., pastor x., torriente a., garcia s. (2009) deep-sea coralligenous beds observed with rov on four seamounts in the western mediterranean. in: pergent-martini c., brichet m. (eds), proceedings of the 1st symposium on the coralligenous and other calcareous bio-concretions of the mediterranean sea, car/asp publ, tabarka, 41-46. aguirre j., braga j.c. (2012) upper pliocene multistory rhodoliths from cádiz (atlantic spain). in: aguirre j., rösler a., braga j.c. (eds) iv international rhodolith workshop, abstract volume and field trip guide, granada, 5. aguirre j., braga j.c., martin j.m. (1993) algal nodules in the upper pliocene deposits at the coast of cádiz (s spain). in: barattolo f., de castro p, parente m. (eds), studies on fossil benthic algae. bollettino della società paleontologica italiana, volume speciale 1, 1-7. aguirre j., braga j.c., bassi d. (2017) rhodoliths and rhodolith bed in the rock record. in: riosmenarodríguez r., wendy nelson w., aguirre j. (eds), rhodolith/maërl beds: a global perspective, coastal research library 15, springer, 105-138. amado-filho g.m., maneveldt g., manson r.c.c., marina rosa b.v., pacheco m.r., guimarães s.m.p.d. (2007) structure of rhodolith beds from 4 to 55 meters deep along the southern coast of espírito santo state, brazil. ciencas marinas, 33, 371-391. andersson a.j., mackenzie f.t., bates n.r. (2008) life on the margin: implications of ocean acidification on mg-calcite, high latitude and cold-water marine calcifiers. marine ecology progress series, 373, 265-273. angeletti l., basso d., bracchi v.a., caragnano a., caronni s., d’onghia g., grande v., marchese f. (2017) report sottoprogramma 2.4. monitoraggio dell’estensione dei fondi a maerl/rodoliti. giugno 2017, pp 46. ashley g. (1990) classification of large scale subaqueous bedforms: a new look at an old problem. journal of sedimentary petrology, 60, 160-172. bahia r.g., abrantes d.p., braisleiro p.s., pereira-fihlo g.h., amado fihlo g.m. (2010) rhodolith bed structure along a depth gradient on the northern coast of bahia state, brazil. brazilian journal of oceanography, 58, 323-337. ballesteros e. (2006) mediterranean coralligenous assemblages: a synthesis of present knowledge. oceanography and marine biology: annual review, 44, 123-195. barberá c., moranta j., ordines f., ramón m., de mesa a., díaz-valdés m., grau a.m., massutí e. (2012) biodiversity and habitat mapping of menorca channel (western mediterranean): implications for conservation. biodiversity and conservation, 21, 701-728. bassi d. (1995) crustose coralline algal pavement from late eocene colli berici of northern italy. rivista italiana di paleontologia e stratigrafia, 101, 81-92. bassi d. (2005) larger foraminiferal and coralline algal facies in an upper eocene storm influenced, shallow water carbonate platform (colli berici, northeastern italy). palaeogeography palaeoclimatology palaeoecology, 226, 17-35. bassi d., nebelsick j.h. (2010) components, facies and ramps: redefining upper oligocene shallow water carbonates using coralline red algae and larger foraminifera (venetian area, northeast italy). palaeogeography, palaeoclimatology, palaeoecology, 295 (1-2), 258-280. basso d. (1994) study of living calcareous algae by a paleontological approach: the non-geniculate corallinaceae (rhodophyta) of the soft bottoms of the tyrrhenian sea (western mediterranean). the genera phymatolithon foslie and mesophyllum lemoine. rivista italiana di paleontologia e stratigrafia, 100(4), 575-595. basso d. (1995) living calcareous algae by a paleontological approach: the genus lithothamnion heydrich nom. cons. from the soft bottoms of the tyrrhenian sea (mediterranean). rivista italiana di paleontologia e stratigrafia, 101(3), 349-366. basso d. (1998) deep rhodolith distribution in the pontian islands, italy: a model for the paleoecology of a temperate sea. palaeogeography palaeoclimatology palaeoecology, 137, 173-187. basso d. (2012) carbonate production by calcareous red algae and global change. geodiversitas, 34, 13-33. 145 deep resilient rhodolith bed of egadi archipelago basso d., brusoni f. (2004) the molluscan assemblage of a transitional environment: the mediterranean maërl from off the elba island (tuscan archipelago, tyrrhenian sea). bollettino malacologico, 40(1-4), 37-45. basso d., corselli c. (2007) molluscan paleoecology in the reconstruction of coastal changes. in: yanko -hombach v., gilbert a.s., panin n., dolukhanov p.m. (eds), the black sea flood question: changes in coastline, climate, and human settlement. nato science series iv, earth and environmental science, kluwer academic press, dordrecht, 2346. basso d., tomaselli v. (1994) paleoecological potentiality of rhodoliths: a mediterranean case history. bollettino della società paleontologica italiana, spec. vol. 2, atti del v simposio di ecologia e paleoecologia delle comunità bentoniche, roma 28-30/9/1992, 17-27. basso d., fravega p., piazza m., vannucci g. (1998) biostratigraphic, paleobiogeographic and paleoecological implications in the taxonomic review of corallinaceae. rendiconti accademia dei lincei, 9, 201-211. basso d., nalin r., nelson c.s. (2009). shallow water sporolithon rhodoliths from north island (new zealand). palaios, 24, 92-103. basso d., babbini l., kaleb s., bracchi v., falace a. (2016) monitoring deep mediterranean rhodolith beds. aquatic conservation: marine and freshwater ecosystems, 26, 549-561. basso d., babbini l., ramos-esplá a.a., salomidi m. (2017) mediterranean rhodolith beds. in: riosmena-rodríguez r., nelson w., aguirre j. (eds), rhodolith/maërl beds: a global perspective, coastal research library 15, springer, 281-298. bellan-santini d., lacaze j.c., poizat c. (1994) les biocénoses marines et littorales de méditerranée, synthèse, menaces et perspectives. collection patrimoines naturels. secrétariat de la faune et de la flore/m.n.h.n. 19, pp. 246. biomaerl team (2003) conservation and management of northeast atlantic and mediterranean maërl beds. aquatic conservation: marine and freshwater ecosystems, 13, s65-s76. bordehore c., borg j. a., lanfranco e., ramos-esplá a., a rizzo m., schembri p.j. (2000) trawling as a major threat to mediterranean maerl beds, presented at the first mediterranean symposium on marine vegetation, regional activity centre for specially protected areas [unep mediterranean action plan], ajaccio, corsica, france 2-3 october 2000. bordehore c., borg j.a., lanfranco e., ramos-esplá a.a., rizzo f., schembri p.j. (2002) trawling as a major threat to mediterranean maërl beds. proceedings of the first mediterranean symposium on marine vegetation, ajaccio. mednature, 1, 105109. bordehore c., ramos-esplá a., riosmena-rodriguez r. (2003) comparative study of two maerl beds with different otter trawling history, southeast iberian peninsula. aquatic conservation: marine and freshwater ecosystems, 13, s43-s54. borg j.a., lanfranco e., mifsud j.r., rizzo m., schembri p.j. (1999) does fishing have an impact on maltese maerl grounds? in: moore p.o. (ed.) biomaerl team. final report, biomaerl project. 133ec contract mas3-ct95-0020, 100133. bosence d. w. j. (1976) ecological studies on two unattached coralline algae from western ireland. paleontology, 19, 365-395. bosence d.w.j. (1983a) the occurrence and ecology of recent rhodoliths a review. in: peryt t.m. (ed), coated grains. springer, berlin, heidelberg, 225242. bosence d.w.j. (1983b) description and classification of rhodoliths (rhodoids, rhodoliths). in: peryt t.m. (ed), coated grains. springer, berlin, heidelberg, 217-224. bosence d.w.j, pedley h.m. (1982) sedimentology and paleoecology of a miocene coralline algal biostrome from the maltese island. palaeogeography palaeoclimatology palaeoecology, 38, 9-43. bosellini a, ginsburg r.n. (1971) form and internal structure of recent algal nodules (rhodoliths), bermuda. journal of geology, 79, 669-682. bracchi v.a., savini a., basso d. (2011) study of maërl facies from southern italy and relevant acoustic signal from chirp and side scan sonar. bulletin of the geological society of finland, 83, special issue 1, the geohab conference abstract volume, 17. braga j.c. (2003) application of botanical taxonomy to fossil coralline algae (corallinales, rhodophyta). acta micropaleontologica sinica, 20, 47-56. braga j.c. (2017) neogene rhodoliths in the mediterranean basins. in: riosmena-rodríguez r., wendy nelson w., aguirre j. (eds.), rhodolith/maërl beds: a global perspective. coastal research library 15, springer, 169-193. braga j.c., martin m. (1988) neogene coralline algal growth-forms and their paleoenvironments in the almanzanora river valley (almeria, spain). palaeogeography palaeoclimatology palaeoecology, 67, 285-303. braga j.c., martin j.m., aguirre j., baird c.d., grunnaleite i., bo jensen n., puga-bernabéu a., sælen g., talbor m.r. (2010) middle miocene (serravallian) temperate carbonates in a seaway connecting the atlantic ocean and the mediterranean sea (north betic strait, s spain). sedimentary geology, 225, 19-33. bressan g., babbini l. (2003) corallinales del mar mediterraneo: guida alla determinazione. biologia marina mediterranea, 10 (2), pp. 237. bressan g., babbini l., ghirardelli l., basso d. (2003) bio-costruzione e bio-distruzione di corallinales nel mar mediterraneo. biologia marina mediterranea, 8(1), 131-174. cabioch, j. (1969) les fonds de maerl de la baie de morlaix et leur peuplement vegetal. cahiers de biologie marine, 10, 139161. 146 bracchi v.a. et al. canals m., ballesteros e. (1997) production of carbonate particles by phytobenthic communities on the mallorca-menorca shelf, northwestern mediterranean sea. deep sea research part ii: topical studies in oceanography, 44(3-4), 611-629. castriota l., agamennone f., sunseri g. (2005) the mollusc community associated with maerl beds of ustica island (tyrrhenian sea). cahiers de biologie marine, 46, 289-287. catalano r., di stefano p., sulli a., vitale f. (1996) paleogeography and structure of the central mediterranean. sicily and its offshore. tectonophysics, 260, 291-323. checconi a., bassi d., monaco p., carannante g. (2010) re-deposited rhodoliths in the middle miocene hemipelagic deposits of vitulano (southern apennines, italy): coralline assemblages characterization and related trace fossil. sedimentary geology, 225, 50-66. chimienti g., angeletti l., mastrototaro f. (2018a) withdrawal behaviour of the red sea pen pennatula rubra (cnidaria: pennatulacea). the european zoological journal, 85, 64-70. chimienti g., angeletti l., rizzo l., tursi a., mastrototaro f. (2018b) rov vs trawling approaches in the study of benthic communities: the case of pennatula rubra (cnidaria: pennatulacea). journal of the marine biological association of the united kingdom, 98, 1859-1869. coco g., murray a.b., green m.o., hume t., thieler r. (2007) sorted bedforms as self-organizing patterns. part 2: complex forcing scenarios. journal of geophysical research, 112, f03016. colantoni p., ligi m., morsiani m.p., penitenti d., (1993) morphology and recent sedimentary evolution of the western sicilian continental shelf. geological development of the sicilian-tunisian platform. unesco reports in marine science, 58, 93-98. coletti g., vezzoli g., di capua a., basso d. (2016) reconstruction of a lost carbonate factory based on its biogenic detritus (ternate-travedona formation and gonfolite lombarda group northern italy). rivista italiana di paleontologia e stratigrafia, 122(3), 1-22. coletti g., bracchi v.a., marchese f., basso d., savini a., vertino a., corselli c. (2017) quaternary build-ups and rhodalgal carbonates along the adriatic and ionian coasts of the italian peninsula: a review. rivista italiana di paleontologia e stratigrafia, 124(2), 387-406. directive 2008/56/ec (2008) directive of the european parliament and of the council of 17 june 2008 establishing a framework for community action in the field of marine environmental policy (marine strategy framework directive). official journal of the european union, l 164/19. emodnet bathymetry consortium (2018) emodnet digital bathymetry (dtm 2018). emodnet bathymetry consortium. doi: 10.12770/18ff0d48-b203-4a65-94a95fd8b0ec35f6 foster m.s. (2001) rhodoliths: between rocks and soft places. journal of phycology, 87, 659-667. foster m.s., riosmena-rodriguez r., steller d.s., woelkerling w.j. (1997) living rhodolith beds in the gulf of california and their implication in paleoenvironmental interpretation. in: johnson m.e., ledesma-vazquez j. (eds), pliocene carbonates and related facies flaking the gulf of california, baja california. geological society of america, special paper, 318, 27-139. foster m.s., amado filho g.m., kamenos n.a., riosmena-rodríguez r., steller d.l. (2013) rhodoliths and rhodoliths beds. smithsonian contributions to the marine sciences, 39, 143-155. freiwald a., henrich r. (1994) reefal coralline algal build-ups within the arctic circle: morphology and sedimentary dynamics under extreme environmental seasonality. sedimentology, 41, 963-984. gagnon p., matheson k., stapleton m. (2012) variation in rhodolith morphology and biogenic potential of newly discovered rhodolith bed in newfoundland and §labrador (canada). botanica marina, 55, 8599. gao k., zheng y. (2010) combined effects of ocean acidification and solar uv radiation on photosynthesis, growth, pigmentation and calcification of the coralline alga corallina sessilis (rhodophyta). global change biology, 16, 2388-2398. guillén j., bourrin f., palanques a., durrieu de madron x., puig p., buscail r. (2006) sediment dynamics during wet and dry storm events on the têt inner shelf (sw gulf of lions). marine geology 234, 129 -142. guiry m.d., guiry g.m. (2019) algaebase. world-wide electronic publication, national university of ireland, galway. http://www.algaebase.org; searched on 15 february 2019. halfar j., mutti m. (2005) global dominance of coralline red-algal facies: a response to miocene oceanographic events. geology, 33(6), 481-484. hammer s., levin i. (2017) monthly mean atmospheric 14co2 at jungfraujoch and schauinsland from 1986 to 2016. tellus b, 65, 20092. henriques m.c., villas-boas a., riosmena rodríguez r., figueiredo m.a.o. (2012) new records of rhodolith-forming species (corallinales, rhodophyta) from deep water in espírito santo state, brazil. helgoland marine research, 66, 219-231. hermand j.p., stefanon a., michelozzi e., agate m., borruso a., d’argenio a., di maio d., lo iacono c., mancuso m., scannavino m. (1999) the acoustic inversion method applied to the study of the continental shelf. marettimo island, italy. in: caiti a., hermand j.-p., porter m.b., jesus s. (eds), experimental acoustic inversion methods for exploration of the shallow water environment. modern approaches in geophysics, kluwer academic publishers, dordrecht, pp. 293. hrabovský j., basso d., doláková n. (2015) diagnostic characters in fossil coralline algae (corallinophycidae: rhodophyta) from the miocene of southern moravia (carpathian foredeep, czech 147 deep resilient rhodolith bed of egadi archipelago republic). journal of systematic paleontology, 14 (6), 499-535. irvine l.m., chamberlain y.m. (1994) seaweeds of the british isles, vol. 1. rhodophyta, part 2b corallinales, hildenbrandiales. london: her majesty's stationery office, pp. 276. jackson c.m., kamenos n.a., moore p.g., young m. (2004) meiofaunal bivalves in maerl and other substrata; their diversity and community structure. ophelia, 58(1), 49-60. littler m.m., littler d.s. (1984) models of tropical reef biogenesis: the contribution of algae. in: round f.e., chapman v.j. (eds), progress in phycological research, 3, biopress, london, 323-364. littler m.m., littler d.s., hanisak m.d. (1991) deepwater rhodolith distribution, productivity and growth history at sites of formation and subsequent degradation. journal of marine biology and ecology, 150, 163-182. lo iacono c. (2004) geomorphologic, sedimentological and ecological aspects of egadi islands offshore (nw tyrrhenian sea), università di napoli ‘‘federico ii’’, naples, italy. ph.d. thesis . lo iacono c., guillén j. (2008) environmental conditions for gravelly and pebbly dunes and sorted bedforms on a moderate-energy inner shelf (marettimo island, italy, western mediterranean). continental shelf research, 28, 245-256. lund m., davies p.j., braga j.c. (2000) coralline algal nodules off fraser island, eastern australia. facies, 42, 25-34. lykousis v. (2001) subaqueous bedforms on the cyclades plateau (ne mediterranean) evidence of cretan deep water formation? continental shelf research, 21, 495-507. manzella g.m.r., gasparini g.p., astraldi m. (1988) water exchange between the eastern and western mediterranean through the strait of sicily. deepsea research, 35, 1035-1121. marrack e.c. (1999) the relationship between water motion and living rhodolith beds in the southwestern gulf of california, mexico. palaios, 14, 159171. martin s., gattuso j. (2009) response of mediterranean coralline algae to ocean acidification and elevated temperature. global change biology, 15, 2089-2100. massutti e., reñones o., carbonell a., oliver p. (1996) demersal fish communities exploited on the continental shelf and slope off majorca (balearic islands, nw mediterranean). vie et milieu, 46(1), 45 -55. mccoy s.j., ragazzola f. (2014) skeletal trade-offs in coralline algae in response to ocean acidification. nature climate change, 4, 719-723. micallef a., le bas t., huvenne v.a.i., blondel p., huhnerbach v., deidun a. (2012) a multi-method approach for benthic habitat mapping of shallow coastal areas with high-resolution multibeam data. continental shelf research, 39, 14-26. miller a.r. (1972) speculation concerning bottom circulation in the mediterranean sea. in: stanley, d.j. (ed), the mediterranean sea: a natural sedimentation laboratory. hutchinson & ross inc., dowden, 37-42. murray a.b., thieler e.r. (2004) a new hypothesis and exploratory model for the formation of large-scale inner-shelf sediment sorting and “rippled scour depressions”. continental shelf research, 24, 295 -315. nash m.c., uthicke s., negri a.p., cantin, n.e. (2015) ocean acidification does not affect magnesium composition or dolomite formation in living crustose coralline algae, porolithon onkodes in an experimental system. biogeosciences, 12, 52475260. nelson w. (2009) calcified macroalgae critical to coastal ecosystems and vulnerable to change a review. marine freshwater research, 60, 787-801. ordines f., ramón m., rivera j., rodríguez-prieto c., teresa farriols m., guijarro b., pasqual c., massuti e. (2017) why long term trawled red algae beds off balearic islands (western mediterranean) still persist? regional studies in marine science, 15, 39-49. palanques a., puig. p., guillén j., jiménez j., gracia v., garcìa m., salat j., sànchez arcilla a., stive m.j.f., madsen o. (2002) nearbottom suspended sediment fluxes on a river-influenced, tideless fetch limited shelf (the ebro delta, northwestern mediterranean). continental shelf research, 22 (2), 285-303. peña v., bárbara i. (2008) biological importance of atlantic maërl bed off benencia island (northwestern iberian peninsula). botanica marina, 51, 493-505. pérès j.m. (1982) major benthic assemblages. in: kinne o. (ed), marine ecology a comprehensive, integrated treatise on life in oceans and coastal waters, 5(1), london, john-wiley publication, 373522. pérès j.m., picard j. (1964) nouveau manuel de bionomie benthique de la mer méditerranée. récent travaux de la station marine d’endoume, marseille, 31(47), 5-138. polizzi s., lo iacono c, agate m., sulli a. (2011) sedimentary dynamics of the marettimo continental shelf and marettimo channel (egadi islands western mediterranean): analysis of depositional and erosional features. viii fist geoitalia 2011, torino, italy, proceedings, p. 256. prager e.j. (1987) the growth and structure of calcareous nodules (for algaliths) on florida’s outer shelf. thesis, univ. miami. pp. 65. ramsey c. (2009) bayesian analysis of radiocarbon dates. radiocarbon, 51(1), 337-360. relini g., giaccone g. (2009). gli habitat prioritari del protocollo spa/bio (convenzione di barcellona) presenti in italia. schede descrittive per l'identificazione. biologia marina mediterranea, 16(1), pp. 372. riosmena-rodríguez, r. (2017) natural history of rhodolith/maërl beds: their role in near-shore biodiversity and management. in: r. riosmena 148 bracchi v.a. et al. rodríguez et al. (eds), rhodolith/maërl beds: a global perspective, coastal research library 15, springer international publishing switzerland, 326. riul p, targino c.h., farias j.d.n., visscher p.t., horta p.a. (2008) decrease of lithothamnion sp. (rhodophyta) primary production due to the deposition of a thin sediment layer. journal of marine biological association uk, 88, 17-19. riul p., lacouth p., pagliosa p.r., christoffersen m.l., horta p. (2009) rhodolith beds at the eastermost extreme of south america: community structure on an endangered environment. aquatic botany, 90, 315-320. ryan d.a., brooke b.p., collins l.b., kendrick g.a., baxter k.j., bickers n.a., siwabessy p.j.w., pattiaratchi c.b. (2007) the influence of geomorphology and sedimentary processes on shallow water benthic habitat distribution: esperance bay, western australia. estuarine, coastal and shelf science, 72 (1-2), 379-386 sañé e., chiocci f.l., basso d., martorelli e. (2016) environmental factors controlling the distribution of rhodoliths: an integrated study based on seafloor sampling, rov and side scan sonar data, offshore the w-pontine archipelago. continental shelf research, 29, 10-22. sanz-lázaro c., belando m.d., marín-guirao l., navarrete-mier f., marín a. (2011) relationship between sedimentation rates and benthic impact on maërl beds derived from fish farming in the mediterranean. marine environmental research, 71(1), 22-30. santoro v.c., amore e., cavallaro l., cozzo g., foti e. (2002) sand waves in the messina strait, italy. journal of coastal research, special issue, 36, 640-653. sartoretto s., verlaque m., laborel j. (1996) age of settlement and accumulation rate of submarine “coralligène” (-10 to -60 m) of the northwestern mediterranean sea, relation to holocene rise in sea level. marine geology, 130, 317-331. saulquin b., hamdi a., gohin f., populus j., mangin a., fanton o. (2013) estimation of the diffuse attenuation coefficient kdpar using meris and application to seabed habitat mapping. remote sensing of environment, 128, 224-233. savini a., basso d., bracchi v.a., corselli c., pennetta m. (2012) maerl-bed mapping and carbonate quantification on submerged terraces offshore the cilento peninsula (tyrrhenian sea, italy). geodiversitas, 34(1), 77-98. sciberras m., rizzo m., mifsud j.r., camilleri k., borg j.a., lanfranco e., schembri p.j. (2009) habitat structure and biological characteristics of a maërl bed off the northeastern coast of the maltese islands (central mediterranean). marine biodiversity, 39, 251-264. siani g., paterne m., arnold m., bard e., metivier b., tisnerat n., bassinot f. (2000) radiocarbon reservoir ages in the mediterranean sea and black sea. radiocarbon 42: 271-280. sneed e.d., folk r.l. (1958) pebbles in the lower colorado river, texas: a study in particle morphogenesis. journal of geology, 66, 114-150. southard j.b., boguchwal l.a. (1990) bed configurations in steady unidirectional water flow. part 2. synthesis of flume data. journal of sedimentary petrology, 60, 658-679. steller d.l., foster m.s. (1995) environmental factors influencing distribution and morphology of rhodoliths of bahía concepción, b.c.s. mexico. journal of experimental marine biology and ecology, 194, 201-212. steller d.l., riosmena-rodriguez r., foster m.s., roberts c.s. (2003) rhodolith bed diversity in the gulf of california: the importance of rhodolith structure and consequence of disturbance. aquatic conservation: marine and freshwater ecosystems, 13, s5-s20. steller d.l., foster m.s., riosmena-rodriguez r. (2009) living rhodolith bed ecosystems in the gulf of california: in: johnson m.e., ledesma-vazquez j. (eds), atlas of coastal ecosystems in the gulf of california: past and present. university of arizona press, tucson, 72-82. steneck r.s. (1986) the ecology of coralline algal crusts: convergent patterns and adaptive strategies. annual review of ecological systems, 17, 273-303. tâmega f., bassi d., figueiredo m., cherkinsky a. (2014) deep-water rhodolith bed from central brazilian continental shelf, campos basin: coralline algal and faunal taxonomic composition. journal of coral reef studies, 16 (1), 21-31. teichert s. (2014) hollow rhodoliths increase svalbard’s shelf biodiversity. scientific reports, 4, 6972. teichert s., woelkerling w., rüggeberg a., wisshak m., piepenburg d., meyerhöfer m., form a., büdenbender j., freiwald a. (2012) rhodolith beds (corallinales, rhodophyta) and their physical and biological environment at 80°31�n in nordkappbukta (nordaustlandet, svalbard archipelago, norway). phycologia, 51, 371-390. toscano f., vigliotti m., simone l. (2006) variety of coralline algal deposits (rhodalgal facies) from the bays of naples and pozzuoli (northern tyrrhenian sea, italy). in pedley h.m., carannante g. (eds), cool-water carbonates: depositional systems and palaeoenvironmental controls: geological society, london, special publications, 255, 85-94. unep-map-rac/spa (2008) action plan for the conservation of the coralligenous and other calcareous bio-concretions in the mediterranean sea. ed. rac/spa tunis, 21. williamson c.j., najorka j., perkins r., yallop m.l, brodie j. (2014) skeletal mineralogy of geniculate corallines: providing context for climate change and ocean acidification research. marine ecology progress series, 513, 71-84. wilson s., blake c., berges j.a., maggs c.a. (2004) environmental tolerances of free-living coralline algae (maërl): implications for european marine 149 deep resilient rhodolith bed of egadi archipelago conservation. biological conservation, 120, 283293. woelkerling w.j, irvine l.m., harvey a.s. (1993) growth-forms in non-geniculate algae (corallinales, rhodophyta). australian systematic botany, 6, 277-293. woelkerling w.j. (1988) the coralline red algae: an analysis of the genera and subfamilies of non geniculate corallinaceae. british museum natural history press, pp. 268. worms editorial board (2019) world register of mar ine species. avai lable from http:/ / www.marinespecies.org at vliz. accessed 201902-15. 150 bracchi v.a. et al. ms. received: february 15, 2019 final text received: june 14, 2019 base cambiamenti dell’uso del suolo e aumento dell’attività franosa nel territorio di rocchetta sant’antonio (appennino dauno) caterina lamanna1, domenico casarano1 & janusz wasowski1 1cnr-irpi (bari), e-mail: cate.lama@tiscali.it riassunto: lamanna c. et al., cambiamenti dell’uso del suolo e aumento dell’attività franosa nel territorio di rocchetta sant’antonio (appennino dauno). (it issn 0394-3356, 2009). sono state studiate le variazioni dell’attività franosa nell’intero territorio comunale di rocchetta sant’antonio (appennino dauno), nel periodo 1976-2006. la mappatura dei fenomeni franosi è stata condotta facendo principalmente uso di foto aeree e di immagini satellitari ad alta risoluzione (ikonos). le fotografie aeree sono state analizzate in modalità stereoscopica, mentre l’immagine ikonos, dopo il pan-sharpening e l’ortorettificazione, è stata sovrapposta al dtm e visualizzata in tre dimensioni. dallo studio è emerso che la frequenza spaziale delle frane attive nel 2006 è del 160% più alta che all’inizio del periodo di studio, sebbene i dati pluviometrici assumano valori confrontabili nelle due date. dopo il 1976, anno in cui la cee stabilì di concedere incentivi per ogni ettaro di terreno coltivato a grano duro, si è peraltro verificato un incremento di circa il 46% nell’estensione areale del seminativo, soprattutto per le coltivazioni cerealicole. pertanto la più alta suscettibilità alle frane può essere legata al cambio di uso del suolo; infatti i massimi valori assoluti di densità delle frane attive si sono osservati sui terreni divenuti agricoli dopo il 1976 (“nuovo seminativo”), e sui seminativi si è osservato un incremento della franosità nettamente maggiore rispetto alle aree mai coltivate. i terreni divenuti coltivati dopo il 1976 erano già a quella data più franosi dei terreni già seminati. inoltre l’aumento della franosità sul nuovo seminativo è dovuto all’estensione delle colture cerealicole e foraggere su terreni con pendenza mediamente superiore a quella dei terreni già coltivati: il vecchio seminativo era per il 25% su pendenze superiori ai 10° e quasi mai oltre i 15°, mentre il nuovo seminativo è per il 45% su pendenze oltre i 10° e per quasi il 10% oltre i 15°. le coltivazioni su pendenze elevate, marginali nel 1976, hanno finito per riguardare porzioni significative del territorio. quindi, l’incremento delle frane attive è da attribuirsi, almeno in parte, all’estensione delle coltivazioni su terreni più ripidi e già intrinsecamente meno stabili prima di essere coltivati. d’altra parte, le precipitazioni superiori alla media negli inverni tra il 2003 e il 2006, con l’occorrenza di eventi intensi, sono il principale fattore causativo/innescante dei più recenti movimenti franosi. i risultati di questo studio suggeriscono che per pendii profondamente modificati dall’uomo negli ultimi decenni, si deve considerare l’effetto combinato delle variazioni climatiche e dell’uso del suolo per evitare il rischio di sovrastimare l’impatto sulla franosità del solo aspetto climatico. abstract: lamanna c. et al., land use change and increase in landslide activity in the rocchetta s. antonio area (daunia apennines). (it issn 0394-3356, 2009) we examine temporal variations in landslide activity in the context of land use changes and precipitation characteristics in the northwestern part of the apulia region (southern italy). the period considered is from 1976 to 2006. the main study area (72 km2) includes the municipal territory of rocchetta s. antonio (fg), assumed to be a representative portion of the daunia apennines. despite the moderate elevation (from 250 to about 1000 m), the daunia mountains are known for their susceptibility to landsliding, with rainfall events and unwise man activity being the main triggering/causative factors. only the steepest, highest elevation areas include a significant percentage of arboreous land. elsewhere, especially where clay-rich units predominate, the vegetation cover is represented mainly by cultivated land (cereals) and locally by grass land. the rocchetta s. antonio territory is distant only few tens of km from the adriatic coast, and, as the entire daunia region, is characterised by a mediterranean semiarid (sub-apennine) climate with total annual rainfall that typically varies from 600 to 750 mm. the clay-rich flysch formations are widespread in daunia and that makes slopes susceptible to landsliding. the presence of intensely deformed geological units is another factor predisposing to instability. to investigate the differences between historical (1976) and recent (2006) landsliding we first compiled two landslide activity maps. the 1976 landslide inventory was obtained through a systematic interpretation of 1:25000 scale aerial photographs and the 2006 inventory was based on the interpretation of high resolution (1 m pixel) ikonos satellite imagery. for simplicity a distinction was made only between active and inactive landslides. we followed the geomorphic criteria typically adopted for the recognition of landslides and their state of activity from air-borne imagery. to facilitate the interpretation the satellite imagery was first orthorectified and pan-sharpened. then natural colour imagery was draped over a detailed dtm (with 5 m grid size) generated from recent topographic maps at 1:5000 scale. for comparative analysis the information on landslides was presented by quantifying area frequency of landslides (percentage of the total study area occupied by landslides) and their density (number of landslides per km2). in particular, the comparison of the 1976 and 2006 landslide inventories shows large increase in number of active landslides (from 5.7/km2 to 34.4/km2 in terms of density), which corresponds to 160 % increase in aerial frequency. to assess land use change occurred in the same 30 year period we used again 1976 aerial photos and produced a map of historical land use. a map of recent land use was prepared using aster satellite imagery. this imagery was preferred over ikonos data, because the acquisition period of the aster imagery (summer, after harvest) resulted more suitable for land use classification based on automatic supervised procedure. the following three major groups or classes were distinguished: i) agricultural land (sown fields with mainly cereal cultivation ploughing), which represents by far the predominant group ii) arboreous land, including dense shrub and iii) other (including uncultivated and bare land, grass land, pasture, and man-made). the selection of these three groups was driven by the presence of few predominant classes of land cover and land use, as well as by their potential impact on shallow landsliding. to quantify the temporal variations in land use from 1976 to 2000 the map data were expressed as percentage of areal frequency. the results show that about 52% of the land has been used as sown fields in the seventies and that by the year 2000 the percentage increased to 75%. the influence of the land use change on mass movement activity is evident when considering the distributions of active landslides on sown fields. in particular, the results demonstrate that the recent (2006) very high density (7.6%) of active landslides in the areas that have become sown after 1976 (new sown) can be linked to the originally high susceptibility of those areas to landsliding (2.9%), exceeil quaternario italian journal of quaternary sciences 22(2), 2009 139-156 140 c. lamanna et al. 1. introduzione è noto che i cambiamenti di uso del suolo possono influenzare l’instabilità dei pendii su scala locale e regionale, ma si riconosce anche che i loro effetti sono spesso scarsamente compresi e difficili da quantificare (ad es. gostelow & wasowski, 2004). nelle regioni montuose popolate, le frane superficiali spesso sono prodotte dall’interazione tra l’ambiente e l’azione antropica e molti studi hanno mostrato un’evidente relazione tra l’uso del suolo e la stabilità dei versanti (ad es. degraff & canuti, 1988; begueria, 2006). in particolare, il disboscamento, gli incendi e le coltivazioni sulle colline sono considerati i più significativi fattori predisponenti (sidle et al., 1985; cannon, 2000). le aree con vegetazione fitta sono meno suscettibili ai movimenti di versante rispetto a quelle con vegetazione sparsa (gokceoglu & aksoy, 1996). secondo selby (1993), gli alberi che ricoprono le colline aumentano la resistenza al taglio dei suoli per circa il 60%. mehrotra et al. (1996) hanno mostrato che l’attività delle frane aumenta di circa il 15% dove la copertura della vegetazione originale è stata eliminata o alterata. in questo lavoro sono studiate le relazioni tra i fattori ambientali dinamici (cambiamenti di uso del suolo e precipitazioni) e l’attività franosa nei monti dauni. a dispetto del moderato rilievo e della piovosità annuale relativamente bassa, i monti dauni sono noti per la loro suscettibilità al dissesto franoso (ad es. cotecchia, 1963). la regione ha subito una considerevole deforestazione negli ultimi secoli e questo può avere predisposto condizioni di diffusa franosità nelle aree rurali (ad es. parise & wasowski, 2000). in particolare, sono state studiate le variazioni storiche dell’attività franosa occorse dal 1976 al 2006, nel territorio comunale di rocchetta sant’antonio, nell’appennino dauno (fig. 1). il 1976 è una data chiave, in quanto la cee in quell’anno stabilì di concedere un aiuto per ogni ettaro di terreno coltivato a grano duro (regolamento (cee) n. 1143/76). il regolamento ha favorito l’aumento della superficie destinata alla cerealicoltura e la puglia è diventata la principale produttrice di grano duro in italia (conforti, 2002). importanti sono anche le trasformazioni che hanno subito le tecniche di lavorazione dei terreni acclivi con la diffusione delle macchine agricole, in seguito agli incentivi della cee. con i mezzi meccanici moderni, si raggiungono profondità di aratura di 55-60 cm, si forma la “soletta di lavorazione” (pellicola a bassa permeabillità sotto lo strato lavorato) e di conseguenza si ha un rallentamento della percolazione dell’acqua e un ristagno a livello della soletta di lavorazione che favorisce lo slittamento dello strato sovrastante smosso dall’aratura (gisotti e zarlenga, 2004). il territorio di rocchetta, prevalentemente rurale, è noto per i ricorrenti problemi di frane e può pertanto essere considerato come porzione rappresentativa dei monti dauni. vi è evidenza di un incremento della franosità negli ultimi anni e, sebbene manchino studi dettagliati, è opinione comune tra la popolazione locale che una parte di responsabilità sia da attribuire ai cambiamenti climatici. è noto che la suscettibilità al dissesto non è semplice da mappare e modellizzare, anche quando i fattori fisici che la controllano sono conosciuti relativamente bene. pertanto, per dimostrare l’influenza delle precipitazioni e dell’uso (e copertura) del suolo sulla franosità, si sono ottenute le mappe delle frane e di uso del suolo per due date diverse (1976 e 2006). la variazione nell’attivita franosa documentata nei 30 anni considerati è stata analizzata anche tenendo conto dell’andamento delle precipitazioni negli ultimi decenni. l’analisi dei cambiamenti di uso del suolo nell’area di studio è essenziale per un‘esatta comprensione del motivo per cui, nel periodo esaminato, il problema della stabilità dei versanti si sia aggravato. particolare attenzione è stata prestata alle attività antropiche, specialmente alle pratiche agricole, e alle precipitazioni, non solo perchè anche in tempi brevi queste possono subire variazioni significative nello spazio e nel tempo, ma anche perché è stato riconosciuto che i cambiamenti di uso del suolo rappresentano un fattore importante che influenza lo sviluppo di frane indotte dalle precipitazioni (glade, 2003). oltre ai fattori dinamici (uso del suolo e piovosità), si sono considerati alcuni fattori geologici e geomorfologici che, anche se praticamente costanti nell’arco di tempo esaminato, possono dare ulteriori informazioni circa la comprensione dei processi che regolano la stabilità dei pendii nell’area di studio. ding even the area frequency of failures in the fields already sown in 1976 (old sown, 1.8%). in fact, new cultivated land, which is on steeper slopes than older fields, had a landslide density 55% higher than did the older fields in 2006. furthermore, the increase in the frequency of active landsliding observed on both old and new sown fields has been greater than elsewhere (remaining areas). all this demonstrates that land use changes occurred between 1976 and 2006, and in particular the increases in the areal extent of sown fields, have negative influence on the stability of slopes in the study area. clearly, the frequency of slope failures in time results from an interaction of many variables, and it is well known that the most significant temporal controls are often those related to rainfall-induced processes. although relations between climatic events and landslide occurrence can be very complex, our field observations indicated that in daunia highest landslide activity typically occurs in late winter time. indeed, the majority of shallow slope failures registered in 2006 were triggered by late february and march rainfalls that followed a wet winter period. a comparison of the precipitation characteristics in 1976 and 2006 did not show major differences. in particular, by taking into account potential evapotranspiration in the months preceeding the two landslide inventorying periods we demonstrate that potential water input to the soil differed by about 20%. in summary, the results of this work demonstrate clear relations between the land-use changes in the period 1976-2006 and the recent high landslide activity. we thus stress that for hillslope areas profoundly altered by man in the recent decades, the effects of changes in both land use and rainfall patterns have to be considered to avoid a risk of overestimating (or underestimating) the relative impact of climate change or variability on landslide activity. parole chiave: frane attive, uso del suolo, appennino dauno, ikonos. keywords: active landslides, land use, daunia apennines, ikonos. 2. inquadramento geografico, geologia e franosità 2.1 inquadramento geologico e geomorfologico generale l’area presa in esame presenta quote variabili tra 170 e 770 metri s.l.m. e comprende il territorio comunale di rocchetta sant’antonio, paese di modeste dimensioni, posto sulla sommità di un piccolo ri l ievo dell’appennino dauno. l’appennino dauno appartiene all’area di transizione tra la parte più orientale della catena appenninica, ricadente nella provincia di foggia, e la parte più occidentale dell’avanfossa (tavoliere della puglia) (crostella & vezzani, 1964; mostardini & merlini, 1986; dazzaro et al, 1988; ciarcia et al., 2003). le unità della catena, che interessano prevalentemente l’area di studio, sono rappresentate da formazioni essenzialmente torbiditiche: “flysch rosso” (cretaceo superioreoligocene) e flysch numidico (miocene inferiore) attribuite in gran parte al bacino lagonegrese, e flysch di faeto (miocene medio-superiore) appartenente alle unità irpine (di nocera & torre, 1987). litologicamente il “flysch rosso” è costituito da argille grigie o variamente colorate, in strati sottili ed alternati a marne, calcari pulverulenti ed argilliti fogliet141cambiamenti dell’uso del suolo e aumento dell’attività franosa ... tate, calcilutiti tipo scaglia, calcareniti con liste di selce e brecciole (di nocera & torre, 1987). su questi terreni giace il flysch numidico. quest’ultimo è costituito essenzialmente da quarzoareniti e quarzosiltiti di colore grigio, rossastro per alterazione, con sottili intercalazioni di marne argillose varicolori nella parte bassa della successione. a luoghi si osservano arenarie grossolane mal classate, che passano in alto ad arenarie fini e quindi a quarzosiltiti; i livelli di argilla marnosa, per lo più scagliosa, non mostrano una frequenza ritmica (di nocera & torre, 1987). il flysch di faeto è costituito da un’alternanza di calcareniti, calcari marnosi, brecciole con interstrati di marne e argille. la composizione prevalentemente calcarea è dovuta principalmente ad apporti derivanti da una piattaforma carbonatica identificabile con quella apula (dazzaro & rapisardi, 1987). il flysch di faeto poggia con contatto stratigrafico sui livelli sommitali, marnoso-argillosi del “flysch rosso”; quasi sempre però il rapporto tra le due unità risulta disarticolato dagli eventi tettonici pliopleistocenici (di nocera & torre, 1987). infine nella parte nord della zona di studio è presente l’unità di ariano caratterizzata da una notevole variabilità delle litofacies: conglomerati, arenarie, calcafig. 1 immagine da satellite ad alta risoluzione del territorio comunale di rocchetta sant’antonio. si nota l’uso del suolo prevalentemente agricolo (il riquadro mostra l’ubicazione dell’area di studio in italia meridionale). high resolution satellite image of rocchetta s. antonio. note predominantly agricultural land use (inset shows location in southern italy). 142 reniti, sabbie, argille e argille marnose (di nocera & torre, 1987). la presenza di terreni fortemente deformati e tettonizzati, per gli intensi movimenti tettonici a cui sono stati soggetti e che ne hanno modificato profondamente il loro assetto originario, e l’elevata percentuale di componente argillosa contribuiscono a rendere il territorio suscettibile a franare (fig. 2). a ciò si aggiunge l’azione erosiva di alcuni corsi d’acqua, molti dei quali a deflusso stagionale, che solcando le valli rendono ancora più soggetta ai dissesti l’area di studio. per lo scopo di questo studio, le unità geologiche sono state raggruppate in 9 categorie (fig. 3); il criterio usato per la suddivisione è quello della similarità litologica che presuppone il comparabile comportamento geotecnico. la maggior parte dell’area (circa 75%) è ricoperta da terreni ad alto contenuto argilloso. in particolare, le unità del flysch rosso (prevalentemente argil le e argil l i t i ) , corrispondenti al complesso indifferenziato (malatesta et al., 1967), affiorano su oltre il 50% dell’area di studio. anche se tali terreni danno origine a rilievi collinari con moderate pendenze, essi comprendono la maggior parte delle frane censite nella zona. i due gruppi che includono il flysch del miocene, uno composto da calcari marnosi, arenarie e argille, e l’altro composto principalmente da arenarie con intercalazioni di argille marnose, occupano, rispettivamente circa il 23 e il 10% dell’area di studio. i restanti gruppi litologici (sabbie, argille, argille marnose e conglomerati del pliocene; depositi al luvionali terrazzati del pleistocene-olocene; detriti di falda recenti ed attuali dell’olocene; alluvioni recenti ed attuali), rappresentano, ognuno, meno del 10% dell’area. le categorie dove prevale il contenuto litoide sono meno soggette all’instabilità. tuttavia, crolli si manifestano talora nelle rocce arenacee o calcaree. tali rocce in corrispondenza di limitati affioramenti di calcari, brecce e arenarie sovrastanti i terreni argillosi rendono la sommità di alcune alture aspra e scoscesa. 2.2 frane i movimenti di massa sono comuni nell’intera regione dauna (ad es. zezza et al., 1994), tuttavia sono relativamente pochi gli studi pubblicati sulle frane nei monti dauni (ad es. iovine et al., 1996; parise & wasowski, 2000; wasowski et al., 2007). ci sono oltre 20 centri abitati sulle sommità delle colline daune, molti dei quali hanno risentito in passato di problemi di instabilità dei pendii. sebbene la documentazione specifica riguardante l’esatta datazione dei singoli eventi franosi sia disponibile solo raramente, dalle informazioni acquisite presso gli enti locali e dalle dichiarazioni degli abitanti, risulta che negli ultimi anni vi sia stato un aumento dei movimenti di massa in diverse aree urbane e periurbane. è probabile che la stabilità dei pendii ai confini dei centri urbani posti sulle sommità sia gradualmente peggiorata a causa dello sviluppo residenziale e della crescita delle infrastrutture negli ultimi decenni. questo potrebbe aver portato in alcuni casi alla riattivazione di vecchie frane preesistenti. inoltre, l’espansione urbana verso pendii con stabilità marginale ha probabilmente prodotto come risultato l’incremento di nuovi dissesti. negli ultimi anni, inoltre, numerosi e talora estesi movimenti di massa hanno anche determinato perdite delle colture, soprattutto cerealicole, danni alle case rurali e reso impraticabili alcune strade. per esempio, il 7 marzo 2005 una grande frana, provocata dalle abbondanti piogge, determinò danni al tratto dell’autostrada a16 tra candela e lacedonia con conseguente chiusura al traffico e deviazione. tali eventi hanno ravvivato l’attenzione sulla stabilità dei versanti in questa zona tra le autorità locali e nazionali, nonchè tra i ricercatori. mossa et al. (2005) hanno presentato un censimento delle frane, realizzato in ambiente gis, riguardante l’area confinante a nord-ovest con il territorio comunale di rocchetta sant’antonio. la frequenza areale delle frane superiore al 20% (sia attive che vecchie) ottenuta sull’intera area di 132 km 2 dimostra l’elevata suscettibilità dei pendii. i risultati inoltre hanno mostrato che l’incidenza delle frane è più alta nella classe di pendenze comprese tra 10 e 15° seguita da quelle 5-10° e 15-20°. questo indica una resistenza molto bassa (residuale) dei materiali del pendio e suggerisce che una porzione significativa dei dissesti può risultare dalla riattivazione di frane preesistenti. in quefig. 2 “flysch rosso” con blocchi calcarei nel territorio comunale di rocchetta sant’antonio. si notano chiari segni di instabilità. “flysch rosso” with calcareous blocks in the area of rocchetta s. antonio. note clear signs of slope instability. c. lamanna et al. 143 sto senso, frequenti visite su campo condotte negli ultimi anni nell’appennino dauno confermano che le rimobilitazioni stagionali (perlopiù in inverno e primavera) di frane preesistenti sono comuni. nondimeno, anche una franosità superficiale di prima attivazione è diffusa. in molti casi il fattore scatenante sembra collegato alle precipitazioni. per quanto riguarda l’influenza della litologia sulla franosità nell’area di studio, essa ovviamente ha un impatto sulla distribuzione spaziale delle frane (in particolare a scala locale) ma non sulla variazione temporale dell’attività franosa nei trent’anni considerati. infatti, in questo periodo di tempo le analisi delle relazioni tra franosità e litologia hanno mostrato che ci sono comparabili aumenti della franosità attiva in tutte le classi litologiche considerate (lamanna, 2008). quindi il fattore litologia può essere assunto costante coerentemente con gli scopi di questo lavoro. 3. frane e cambio di uso del suolo 3.1 generalità per tracciare un quadro completo dei fenomeni di dissesto nel territorio è stato necessario acquisire dati per mezzo del rilevamento effettuato in campagna e con l’ausilio dell’interpretazione delle foto aeree e delle immagini da satellite. in tal modo sono state prodotte carte inventario dei movimenti di massa e carte tematiche relative ad alcuni fattori correlati all’attività franosa come l’uso del suolo. il rilevamento di campagna, effettuato nel 2005, su un’area più ampia di oltre 300 km 2 ha registrato una densità di 3.2 frane/km 2 , la maggior parte delle quali attive, ed una frequenza areale pari al 5.4%. e’ emerso che tra i cinque territori comunali esaminati, quello di rocchetta sant’antonio, oltre a presentare la più alta densità di frane, 6.2 per km 2 , e la più alta frequenza fig. 3 mappa geo-litologica dell’area di studio – territorio comunale di rocchetta sant’antonio; geologia modificata da malatesta et al. (1967) e jacobacci & martelli (1967). legenda: 1) alluvioni recenti ed attuali; 2) detriti di falda recenti ed attuali (olocene); 3) depositi di frane; 4) depositi alluvionali terrazzati (sabbie, ghiaie e argille) (pleistocene-olocene); 5) sabbie, argille, argille marnose e conglomerati (pliocene); 6) arenarie includenti intercalazioni di argille scistose marnose (miocene); 7) calcari marnosi, arenarie e argille scistose (miocene); 8) complesso indifferenziato (brecce calcaree, calcareniti) (paleogene); 9) complesso indifferenziato (principalmente argille scistose e argille scistose marnose, e secondariamente calcari, calcareniti, brecce, arenarie) (cretaceo superiore-paleogene); 10) faglie; 11) faglie supposte. geo-lithological map of the study area municipal territory of rocchetta s. antonio; geology modified after malatesta et al. (1967) and jacobacci & martelli (1967). legend: 1) recent alluvium; 2) slope debris (holocene); 3) landslide deposit; 4) alluvial terrace deposit (sand, gravel and clay) (pleistocene-holocene); 5) sand, clay, marly clay and conglomerate (pliocene); 6) sandstone including marly clay-shale intercalations (miocene); 7) marly limestone, sandstone and clay-shale (miocene); 8) undifferentiated complex (limestone breccia, calcarenite) (paleogene); 9) undifferentiated complex (primarily clay-shale and marly clay-shale, and secondarily limestone, calcarenite, breccia, sandstone) (late cretaceouspaleogene); 10) fault; 11) fault-inferred. cambiamenti dell’uso del suolo e aumento dell’attività franosa ... 144 areale (11.1%), comprende anche notevoli danni alle infrastrutture, in particolare alle vie di comunicazione (fig. 4). si è quindi ritenuto di focalizzare lo studio sul territorio comunale di rocchetta (72 km 2 ) (fig. 1). in quest’area, solo le sommità più ripide ed elevate includono una percentuale signif icativa di suolo arboreo. altrove, specie dove predominano unità prevalentemente argillose, la copertura vegetale è rappresentata soprattutto da coltivazioni cerealicole e localmente da pascolo nelle zone con vegetazione erbacea intercalate da radi cespugli. le aree incolte sono molto limitate e corrispondono ad affioramenti di litotipi più rocciosi. la densità relativa di insediamenti urbani e rurali, strade ed altre infrastrutture è molto bassa. il territorio di rocchetta è caratterizzato da clima mediterraneo (subappenninico) con piovosità annua tipicamente compresa tra 600 e 750 mm. gli inverni sono umidi e miti, con precipitazioni nevose molto limitate. le estati sono tipicamente calde e asciutte. 3.2 materiali e metodi qualsiasi approccio metodologico, finalizzato alla realizzazione di uno studio sulla variazione della franosità nel tempo e sulle sue cause, prevede un accurato catalogo e un’analisi dei movimenti di massa in atto nell’area. il metodo più comune per l’acquisizione dei dati terrestri e la realizzazione di carte inventario dei fenomeni franosi è quello di mettere insieme mappe derivanti da documenti di varia origine, da rilevamenti sul campo e dall’interpretazione ed elaborazione di dati telerilevati (foto aeree ed immagini da satellite). mantovani et al. (1996) considerarono che mentre le tecniche di fotointerpretazione erano ben note, l’utilizzo delle immagini satellitari era meno diffuso. in particolare, gli autori constatarono che solo un numero limitato di ricercatori sfruttava completamente immagini multispettrali. oggi le immagini da satellite possono costituire una valida alternativa alle foto aeree, e trovare un impiego sempre maggiore per lo studio dei movimenti franosi, grazie alla disponibilità crescente di dati con una risoluzione molto alta (nichol et al., 2006). 3.2.1 dati utilizzati le informazioni ed i data set principali sfruttati nel presente lavoro sono qui elencati: base topografica alle scale 1:5000, 1:2000 e 1:500, del 2002; modello digitale del terreno (dtm) generato dalle mappe in scala 1:5000 citate; fotografie aeree cartacee in b/n, in scala 1:25000, di fig. 4 in alto: muro di sostegno travolto da una frana; si osservano frane superficiali in terreni essenzialmente argillosi del “flysch rosso” (valle capo diavolo, rocchetta sant’antonio). in basso: sede stradale (sp99bis rocchetta-rocchetta scalo) danneggiata da un movimento franoso. upper: photo showing retaining wall sheared by a deep slope movement (foreground) and shallow landslides in clay-rich “flysch rosso”materials in valle capo diavolo, rocchetta s. antonio (background). lover: sp99bis rocchetta-rocchetta scalo road damaged by a landslide. c. lamanna et al. luglio 1976; immagine multispettrale del satellite aster (usando le bande nel visibile e quella nel vicino infrarosso a 15 m di risoluzione), di luglio 2000; immagine multispettrale del satellite ikonos con risoluzione di 1 m in modalità pancromatica, di aprile 2006; dati termometrici mensili e pluviometrici giornalieri. l’interpretazione delle immagini telerilevate si è avvalsa inoltre delle conoscenze locali della geologia e franosità nella zona di studio acquisite durante i numerosi rilievi su campo svolti in situ negli anni 2005-2007. l’analisi, riguardante l’intero territorio comunale di rocchetta sant’antonio, è stata eseguita usando le tecniche gis (geographic information system), in quanto queste ultime oltre a facilitare la preparazione delle carte stesse con maggiore efficienza ed accuratezza rispetto al passato, hanno facilitato l’esame delle relazioni spaziali e temporali tra frane e uso del suolo permettendo di integrare dati di diversa origine, scala, formato e sistema di riferimento cartografico. 3.2.2 metodologia di realizzazione delle carte della franosità per ottenere un catalogo storico delle frane si è effettuata una interpretazione stereoscopica delle foto aeree del 1976. per realizzare le carte delle frane, le fotografie aeree del 1976 sono state sottoposte a scansione, ortorettificate e infine mosaicate in modo da ottenere un’unica immagine dell’area. dopo aver identificato sui fotogrammi i movimenti franosi questi sono stati importati in ambiente gis. nei rilevamenti di campagna si sono osservate frane di varie dimensioni, anche della lunghezza delle decine di metri o inferiore. per poter effettuare la mappatura di movimenti franosi anche di piccole dimensioni, e ottenere un catalogo recente completo delle frane si sono adoperate immagini ikonos ad alta risoluzione, acquisite all’inizio della primavera del 2006. utilizzando una singola immagine ikonos e non la molto costosa coppia stereo, si sono riconosciute essenzialmente le frane attive s.l. e la successiva analisi comparativa con i dati del 1976 si è basata solo su questa categoria di movimenti franosi. invece la mancanza dell’osservazione stereoscopica non ha permesso l’individuazione di diverse frane inattive s.l. riconosciute in sito. anche se non ci sono ancora molti esempi in letteratura di applicazioni dell’immagine ikonos per l’individuazione delle frane, alcuni autori (nichol et al. 2006; van westen et al. 2008) hanno dimostrato chiaramente l’utilità di questo tipo di dati ottici. la mappatura delle frane è stata facilitata dalla visualizzazione tridimensionale dell’immagine sovrapposta al dtm dettagliato. inizialmente, sono state ortorettificate le singole bande (bande 1 4 e pancromatica). successivamente, le immagini sono state elaborate per mezzo della procedura pan-sharpening che ha permesso di osservare le immagini ikonos in colori naturali compositi con 1 metro di risoluzione. l’immagine ikonos, pan–sharpened ed ortorettificata, visualizzata in tre dimensioni in colori naturali, rende chiaramente osservabile la posizione delle frane sui versanti, in particolare di quelle attive (fig. 5). tutte le frane osservate sono state riprodotte sulle carte digitalizzandole sull’immagine ikonos ortorettificata. 3.2.3 metodologia di realizzazione delle carte dell’uso del suolo per mappare l’uso del suolo nel 1976 si sono utilizzate le stesse foto aeree adoperate per realizzare la carta delle frane dello stesso anno. poiché i tentativi di utilizzare procedure automatiche di classificazione hanno fornito risultati inaffidabili, le classi di uso del suolo sono state estratte tramite fotointerpretazione. si sono distinte tre classi principali: “terreno agricolo” (seminativo con coltivazioni, soprattutto cerealicole, comportanti aratura) che rappresenta di gran lunga il gruppo prevalente (fig. 1); “terreno alberato”, includente le formazioni vegetali che presentano copertura sufficientemente densa ed estesa da attenuare l’impeto dell’acqua che scorre in superficie (boschi, macchia, frutteti, alberature adiacenti alle strade e ai corsi d’acqua); 145 fig. 5 particolare dell’immagine ikonos ortorettificata pan-sharpened sovrapposta al dtm (le altezze sono state esagerate di 3 volte): si osservano in dettaglio le frane attive. zoom of pan-sharpened and orthorectified ikonos image overlapped on dtm (3x vertical exaggeration): active landslides are clearly visible. cambiamenti dell’uso del suolo e aumento dell’attività franosa ... “altro” (comprendente incolto, suolo nudo, pascolo e infrastrutture). la scelta dei tre gruppi è stata dettata dai principali tipi di copertura del suolo e di uso del suolo presenti nell’area di studio, come anche dal loro potenziale impatto sulle frane superficiali. inizialmente, la realizzazione della mappa dell’uso del suolo recente è stata tentata utilizzando l’immagine ikonos. tuttavia, poichè si è utilizzata la classificazione automatica (con procedura supervisionata), l’immagine ikonos non ha fornito risultati affidabili (l’acquisizione è avvenuta quando le colture cerealicole e foraggiere erano ancora verdi, con piante di bassa altezza e quindi facilmente confondibili con le aree incolte ed i pascoli). pertanto si è preferito usare l’immagine aster dell’estate 2000, che ha consentito una classificazione automatica dell’uso del suolo (i campi a cereali presentavano una risposta spettrale nettamente diversa dalle zone incolte). un esame qualitativo delle immagini ha suggerito che tra tra il 2000 ed il 2006 vi sono stati cambi di uso del suolo di modesta entità. infatti non risulta che l’area negli ultimi anni sia stata interessata da eventi catastrofici (es. incendi) o da cambiamenti importanti nelle politiche di uso del suolo. pertanto la carta dell’uso del suolo derivata da aster è stata assunta valida anche per il 2006. la classificazione con procedura supervisionata dell’immagine aster è stata eseguita usando tre bande (due nel visibile e una nel vicino infrarosso, vnir). 3.3 distribuzione delle frane al fine di studiare la differenza tra la distribuzione delle frane del 1976 e quelle del 2006 si sono realizzate due serie di mappe dell’attività franosa (cf. soeters & van westen, 1996), derivate da foto aeree ed interpretazione di immagini satellitari. si è seguito il criterio geomorfico tipicamente adottato nella ricognizione delle frane e del loro stato di attività da immagini aeree (ad es. wieczorek, 1984). tenendo conto dello scopo di questo studio si è distinto esclusivamente tra frane attive s.l. ed inattive s.l. la terminologia adottata è ispirata alle indicazioni del wp/wli (1993), leggermente modificate. in particolare, per il fenomeno attivo s.l. intendiamo una frana che si è mossa l’ultima volta entro l’ultimo ciclo stagionale o al massimo nel corso del penultimo. non pretendiamo di distinguere dalle immagini telerilevate le frane attive s.s. (cioè quelle che erano in movimento al momento dell’acquisizione delle foto aeree o immagini satellitari) e i fenomeni sospesi, i.e. quelli che si sono mossi durante gli ultimi due cicli stagionali. per 146 fig. 6 carta delle frane del 1976 e reticolo idrografico sovrapposti al dtm nel territorio di rocchetta. legenda: 1) frane attive nel 1976; 2) frane inattive nel 1976; 3) reticolo idrografico. map of 1976 landslides and hydrographic network draped over dtm (rocchetta s. antonio territory). legend: 1) active landslides in 1976; 2) inactive landslides in 1976; 3) drainage network. c. lamanna et al. frane inattive s.l., in questo lavoro, si intendono quelle che si sono mosse l’ultima volta prima degli ultimi due cicli stagionali; la conoscenza pluriennale della zona di studio suggerisce che una buona parte di queste frane potrebbe essere classificata come fenomeni quiescenti. una caratteristica degli inventari delle frane inattive è che l’evidenza sul terreno dell’esistenza di molte frane più piccole viene persa a causa di modifiche successive come processi erosivi, crescita della vegetazione, influenza antropica inclusi i lavori di aratura. pertanto, con il passare del tempo, i limiti delle frane in genere si distinguono sempre più difficilmente anche dalle fotografie aeree e l’inventario delle frane inattive è più soggetto ad errori ed è meno completo. pertanto, le stime riguardanti la variazione dell’attività franosa nel periodo di 30 anni considerato in questo studio si basano esclusivamente sui dati relativi ai fenomeni attivi. e’ noto che molti fattori influenzano l’affidabilità, la completezza e la risoluzione di una carta inventario, tra cui: la freschezza delle frane e l’età, la qualità e la scala delle immagini telerilevate, la complessità morfologica e geologica dell’area di studio, i tipi di uso del suolo e le sue alterazioni e il grado di esperienza del geomorfologo coinvolto. in particolare, il riconoscimento delle caratteristiche delle frane dalle fotografie aeree in visione stereoscopica è una tecnica soggettiva, empirica e che richiede molta esperienza, pratica, metodologia e criteri di interpretazione ben definiti (malamud et al., 2004). chiaramente, i criteri basati sull’espressione superficiale di forme geomorfiche sono soggettivi; nondimeno, questo lavoro riguarda le variazioni dell’attività franosa considerate come variazione nel tempo della frequenza areale dei movimenti di massa attivi, che pertanto non devono necessariamente indicare un valore assoluto di franosità. 3.3.1 confronto tra la franosità del 1976 e del 2006 i cataloghi delle frane del 1976 (fig. 6) e del 2006 (fig. 7) sono relativi all’intero territorio comunale di rocchetta sant’antonio. in figura 8 sono sintetizzate le differenze di attività franosa. i risultati sono presentati in termini di numero di frane per km 2 e frequenza areale delle frane (percentuale dell’area occupata dalle frane sul totale dell’area) per facilitarne il confronto con altre aree franose. nel valutare le distribuzioni delle frane osservate nelle due date, si sono tenuti presenti i possibili effetti derivanti dalla differente risoluzione e modalità di elaborazione delle foto aeree e dell’immagine satellitare. l’immagine ikonos esaminata, per esempio, permette un’ottima risoluzione delle superfici di distac147 fig. 7 carta delle frane del 2006 e reticolo idrografico sovrapposti al dtm nel territorio di rocchetta. legenda: 1) frane attive nel 2006; 2) frane inattive nel 2006; 3) frane incerte nel 2006; 4) reticolo idrografico. map of 2006 landslides and hydrographic network draped over dtm (rocchetta s. antonio territory). legend: 1) active landslides in 2006; 2) inactive landslides in 2006; 3) uncertain landslides in 2006; 4) drainage network. cambiamenti dell’uso del suolo e aumento dell’attività franosa ... co e dà la possibilità di identificare in dettaglio numerose frane coalescenti laddove sulle fotografie si identifica un’unica frana. invece, alcune grandi frane inattive, identificate sulle foto aeree del 1976, non sono state riconosciute sulle immagini ikonos del 2006, non stereoscopiche. infatti, il catalogo del 2006 include una classe di frane incerte, alcune delle quali si sovrappongono alle aree con frane inattive nel catalogo relativo al 1976 (fig. 6 e fig. 7). nondimeno, le differenze nelle distribuzioni delle frane attive classificate con certezza sono pronunciate, e se ne può dedurre una variazione evidente nell’estensione areale. in particolare, il confronto tra i dati del 1976 e del 2006 mostra un incremento del 160% nella frequenza areale delle frane attive (fig. 8). una tendenza opposta si nota per le frane inattive, passando dal 7.1 all’1.6%, ed alcune delle frane inattive del 1976 risultano attive nel 2006 (fig. 6 e fig. 7). per stimare gli effetti delle due differenti metodologie di osservazione sulla stima del numero e delle aree interessate dalle frane attive, queste sono state suddivise per classi di dimensione. si nota come la distribuzione nelle classi a partire da 2000 m2 sia simile negli inventari relativi alle due date (fig. 9). al contrario si osserva come nel catalogo del 1976 sia molto ridotta la quantità di frane con estensione inferiore a 2000 m2. in particolare nel 1976 l’area interessata da frane superiori a 2000 m2 costituisce l’85% dell’area in frana complessiva, mentre scende al 65% nel catalogo del 2006 (fig. 9). ciò è coerente con la minore risoluzione e con la diversa tecnica di osservazione delle foto aeree, che rende non riconoscibili le frane di estensione minima, e individua come frana unica un insieme di piccole frane coalescenti. trascurando quest’ultimo aspetto, e assumendo quindi che la citata differenza tra le distribuzioni sia dovuta esclusivamente alla mancata osservazione di frane di piccole dimensioni nelle foto aeree del 1976, se ne ricava una sottostima del 25% dell’area in frana complessiva a quella data. tale assunzione è tuttavia assolutamente cautelativa, in quanto considera come “non osservata” l’area interessata da movimenti coalescenti di piccole estensioni che invece possono essere individuati come singolo movimento di estensione maggiore. una stima più ragionevole parte dalla constatazione della grande difficoltà, sulle foto aeree del 1976, del censimento di frane attive singole con dimensioni inferiori a 1000 m2. frane di queste dimensioni occupano complessivamente circa il 18% dell’intera area in frana nel catalogo del 2006 e solo il 3.4 % nel catalogo del 1976 148 fig. 8 statistica della franosità per il 1976 e il 2006; in alto: frequenza areale in %; in basso: numero per km2. la percentuale è riferita all’intera area di studio (72 km2); le frane incerte sono principalmente dovute alla mancanza di stereoscopia nell’immagine del 2006. landslide statistics for 1976 and 2006; upper: area frequency in %; lower: number per km2. the percentage is referred to the entire study area (72 km2); uncertain landslides are mainly due to the lack of stereoscopy in 2006 imagery. fig. 9 aree (km2) interessate dalle frane attive nel 1976 e nel 2006 suddivise per classi di estensione (m2) delle stesse. areas (km2) affected by active landsliding in 1976 and 2006 according to different size classes (m2) of landslides. c. lamanna et al. (fig. 9): ne consegue una discrepanza, dovuta alla differente metodologia di osservazione, inferiore al 15%. questo valore, non altera significativamente l’evidenza dell’aumento dell’attività franosa. infatti, assumendo per il 1976 una sottostima dell’area in frana pari al 15%, l’incremento della franosità tra il 1976 e il 2006 risulta comunque superiore al 120%. 3.3.2 distribuzione delle frane e reticolo idrografico mossa et al. (2005) studiando la franosità dell’area a nord-ovest del territorio di rocchetta sant’antonio hanno osservato che la distribuzione delle frane è strettamente connessa ai sistemi locali di drenaggio. l’interpretazione delle foto aeree del 1976 e delle immagini da satellite ikonos del 2006 forniscono le stesse indicazioni per la zona in esame in questo lavoro. infatti, considerando il modello del locale drenaggio dell’intera area di studio, estratto dalla ctr al 5000, sovrapposto alle carte inventario delle frane del 1976 e del 2006 (fig. 6, fig. 7), si osserva che le frane e il reticolo drenante sono intimamente legati sia perché spesso le frane raggiungono i corsi d’acqua (e sono erose al piede), sia perchè si attivano entro le vallecole fluviali. per fornire informazioni più oggettive sulle relazioni tra la distribuzione delle frane e i corsi d’acqua sono state condotte alcune analisi quantitative. si sono considerate quattro zone di rispetto di ampiezza crescente intorno ai corsi d’acqua: la prima tra 0 e 20 m, la seconda tra 20 e 40 m, la terza tra 40 e 80 m e l’ultima tra 80 e 160 m. quindi si sono effettuate le intersezioni delle superfici così delimitate con le frane attive e i dati sono stati espressi in termini di frequenze areali (fig. 10). si osserva che la frequenza areale delle frane attive del 1976 e del 2006 decresce con la distanza dal corso d’acqua e intorno al reticolo idrografico vi è una più alta concentrazione di movimenti franosi rispetto al valore medio sull’intero territorio comunale di rocchetta. inoltre si osserva un aumento pressocchè uniforme della frequenza areale delle frane attive dal 1976 al 2006, su tutta l’area considerata, quindi l’influenza del corso d’acqua sulle variazioni della franosità non è cambiata in maniera significativa nei trent’anni considerati. 3.4 franosità attiva e variazioni nell’uso del suolo dopo avere ricavato le mappe dell’uso del suolo relative al 1976 (fig. 11a) ed al 2006 (fig. 11b) per indicare le variazioni dell’uso del suolo nel periodo considerato, i dati mappati sono stati espressi come percentuale dell’area totale. i risultati mostrano che circa il 52% dell’area era usata come seminativo negli anni ’70 e che fino all’anno 2000 tale percentuale era cresciuta fino al 75%. un cambiamento così pronunciato dell’uso del suolo in un’area montuoso-collinare può aver avuto un impatto sulla stabilità dei pendii. i terreni alberati e l’altro, invece, sono diminuiti in estensione: per l’“altro”, vi è stato un aumento delle aree antropizzate e una diminuzione delle aree incolte. l’influenza dei cambiamenti di uso del suolo sui movimenti franosi può essere evidenziata considerando la distribuzione delle frane attive sui campi coltivati (fig. 11a e fig. 11b). un confronto visuale delle mappe del 1976 e del 2006 indica che i terreni divenuti agricoli dopo il 1976 (“nuovo seminativo”) sono caratterizzati da una maggiore densità di frane attive. per evidenziare le correlazioni tra i cambiamenti dell’estensione areale del seminativo e le variazioni delle frane attive, si sono considerati separatamente i terreni a seminativo già nel 1976 (vecchio seminativo) e quelli divenuti tali solo dopo quella data (nuovo seminativo) (fig. 12). sul vecchio e sul nuovo seminativo le frane attive si sono quasi triplicate (rispettivamente +181% e +161%); tuttavia il nuovo seminativo era più franoso già prima di essere coltivato. nel 1976 infatti, la frequenza areale delle frane in queste aree era del 2.9%, superiore anche a quella che si riscontrava sui terreni già adibiti a seminativo (1.8%). si nota anche che nello stesso periodo la frequenza di frane attive nelle restanti aree (non seminate nel 1976 e neppure oggi) è aumentata molto meno (+98%). questo suggerisce che le coltivazioni e le relative arature rendono i pendii più suscettibili alla instabilità. per comprendere meglio la più alta franosità delle aree del nuovo seminativo, l’estensione areale dei seminativi del 1976 e del 2006 è stata suddivisa per classi di pendenza (tab. 1). 149 fig. 10 frequenza areale delle frane attive del 1976 e del 2006 intorno ai corsi d’acqua e nell’intero territorio comunale di rocchetta sant’antonio. area frequency of active landsliding of 1976 and 2006 in different buffers near drainage network and in the entire municipal territory of rocchetta s. antonio. cambiamenti dell’uso del suolo e aumento dell’attività franosa ... pendenza (gradi) 0-5 5-10 10-15 15-20 20-25 > 25 area dei seminativi 1976 (km2) 4.51 22.44 9.66 0.54 0.04 0.02 area dei seminativi 2006 (km2) 6.60 29.34 15.56 2.05 0.42 0.21 tab. 1 distribuzione dei campi coltivati nel 1976 e nel 2006 in funzione della pendenza dei versanti. distribution of sown fields in 1976 and 2006 versus slope angle. 150 fig. 11 carte di uso del suolo e distribuzione delle frane attive nel territorio di rocchetta sant’antonio: a) carta del 1976 ottenuta dall’osservazione stereoscopica delle foto aeree; b) carta del 2006 ottenuta con l’utilizzo delle immagini ikonos e aster. legenda: 1) rocchetta sant’antonio; 2) terreno agricolo; 3) terreno alberato; 4) altro; 5) frane attive. land use and distribution of active landslides in the rocchetta s. antonio territory: a) 1976 map obtained through a stereoscopic interpretation of aerial photos; b) 2006 map derived from ikonos and aster imagery. legend: 1) rocchetta s. antonio; 2) sown field; 3) trees; 4) other; 5) active landslides c. lamanna et al. dalla tabella 1 si evince che la maggior parte dei campi coltivati nel 1976 e nel 2006 ricade nell’intervallo 5-10°. inoltre si osserva che i seminativi su pendenze comprese tra 5 e 10° sono aumentati del 31%, nella classe di pendenza tra 10 e 15° del 61% e oltre i 15° del 342%. appare quindi chiaro che le coltivazioni su pendenze elevate, dapprima marginali, hanno finito per riguardare porzioni significative del territorio. per approfondire ulteriormente le ragioni alla base della più alta franosità delle aree seminate dopo il 1976, si è confrontata la loro distribuzione di pendenze con quella delle aree già coltivate nel 1976 (tab. 2). i risultati mostrano che i terreni di recente coltivazione sono caratterizzati da pendenze significativamente più elevate, mentre i campi già coltivati nel 1976 mostravano pendenze più dolci. questo suggerisce che l’incremento delle frane attive sia risultato, almeno in parte, dall’estensione delle coltivazioni su terreni più ripidi e presumibilmente meno stabili. considerando la frequenza areale delle frane attive nel 1976 e nel 2006 in ciascuna classe di pendenza (tab. 3), si osserva che dal 1976 al 2006 c’è stato un aumento percentuale delle aree in frana in tutte le classi di pendenza. infine, considerando le frequenze areali delle frane attive del 1976 e del 2006 sul nuovo seminativo (tab. 4), nelle diverse classi di pendenza, si osserva un incremento generale della franosità dal 1976 al 2006. l’aumento è più alto nella classe 1015° (oltre il 180%); inoltre la più alta frequenza di frane attive (oltre il 10%) si è osservata nelle classi 10-15° e 15-20°, che includono circa la metà di tutte le aree coltivate a cereali dopo i l 1976; questi versanti già nel 1976, ovvero prima di essere coltivati, erano più instabili. questo conferma il legame tra l’estensione delle coltivazioni sui versanti più ripidi e l’aumento delle frane nel 2006. 4. analisi dei dati pluviometrici dall’analisi dei dati sulla franosità e sull’uso del suolo è quindi evidente il maggiore incremento di franosità registrato sui terreni coltivati, ed in particolare l’elevata inci151 fig. 12 variazioni temporali nella frequenza areale delle frane attive (in %) per i campi coltivati e per le restanti aree. il vecchio seminativo rappresenta le aree già coltivate nel 1976, il nuovo seminativo le aree coltivate dopo il 1976, le restanti aree includono i terreni alberati e l’altro. temporal variation in area frequency of active landsliding (in %) for sown fields and remaining areas. the old sown represents areas already sown in 1976, the new sown corresponds to areas sown after 1976, and the remaining areas include arboreous land and other. cambiamenti dell’uso del suolo e aumento dell’attività franosa ... tab. 2 distribuzione delle pendenze dei terreni già coltivati nel 1976 (vecchio seminativo) e di quelle dei terreni coltivati dopo il 1976 (nuovo seminativo). area frequency statistics of slope angles for fields already sown in 1976 (old sown) and those sown after 1976 (new sown). tab. 3 frequenze areali delle frane attive nel 1976 e nel 2006 in ciascuna classe di pendenza. area frequency of active landsliding in 1976 and in 2006 for slope classes. pendenza (gradi) 0-5 5-10 10-15 15-20 20-25 > 25 distribuzione delle pendenze del 12.10 60.30 25.97 1.46 0.12 0.05vecchio seminativo (%) distribuzione delle pendenze del 12.83 42.10 34.30 7.91 1.92 0.94nuovo seminativo (%) pendenza (gradi) 0-5 5-10 10-15 15-20 20-25 25-30 30-35 35-40 >40 frequenza areale frane attive 1976 (%) 0.45 1.65 3.03 3.46 1.76 0.74 0.49 0.36 2.31 frequenza areale frane attive 2006 (%) 1.33 4.13 8.46 7.36 3.90 3.50 3.11 4.60 7.78 tab. 4 frequenza areale delle frane attive nel 1976 e nel 2006 sui campi divenuti agricoli dopo il 1976 (nuovo seminativo) nelle diverse classi di pendenza. area frequency of active landsliding in 1976 and in 2006 for slope classes of fields sown after 1976 (new sown). pendenza (gradi) 0-5 5-10 10-15 15-20 frequenza areale frane attive 1976 su nuovo seminativo (%) 0.72 2.06 4.03 5.85 frequenza areale frane attive 2006 su nuovo seminativo (%) 1.81 5.09 11.29 13.37 denza di frane sul nuovo seminativo. l’analisi delle relazioni tra franosità e uso del suolo non può tuttavia prescindere dallo studio delle precipitazioni che rappresentano nell’area di studio il principale fattore d’innesco delle frane. i dati di pioggia giornalieri disponibili per l’area di studio provengono dalla stazione pluviometrica di rocchetta sant’antonio (servizio idrografico nazionale, 1955-2006) e coprono il periodo 1955 2006. la piovosità media annua è intorno ai 670 mm (con intervallo di variabilità tra 449 e 1037 mm nei 52 anni considerati). inverno ed autunno sono le stagioni più piovose con piovosità media di, rispettivamente, 204 mm (intervallo 75-470 mm) e 195 mm (intervallo 64-360 mm), mentre l’estate è la stagione meno piovosa, con una media di 104 mm (intervallo 24-266). il mese di massima piovosità è novembre con precipitazioni medie di 79 mm, seguito da dicembre con una media di 77 mm; tuttavia, le maggiori precipitazioni mensili, nei 52 anni esaminati, si sono verificate nel mese di gennaio 2003 con 218 mm. i mesi estivi di giugno, luglio e agosto sono tipicamente molto secchi e il mese di luglio è caratterizzato dal più basso tasso di precipitazioni, in media 31 mm (fig. 13). dall’analisi dei dati è emerso che le stagioni invernali tra la fine del 2002 ed il 2006 hanno contribuito ad una fase piovosa, seguita peraltro ad un periodo di grave siccità, e nel contesto di una tendenza al calo pluviometrico sul lungo periodo (polemio & casarano, 2008). ad esempio, il trimestre invernale dicembre 2002-febbraio 2003 è stato il più piovoso in assoluto nei 52 anni considerati (360 mm). inoltre l’inverno 2005-2006, ovvero il periodo immediatamente precedente all’acquisizione dell’immagine ikonos utilizzata per il più recente inventario delle frane, è stato caratterizzato da precipitazioni ben al di sopra della media (299 mm). al contrario il periodo invernale 2001-2002 era stato tra i meno piovosi, 123 mm. altro dato importante è che il 1976 e la sua estate hanno segnato valori record di piovosità (rispettivamente 1037 e 266 mm). per di più, la maggior parte delle precipitazioni dell’estate del 1976 si sono verificate nei mesi di giugno e luglio, ovvero immediatamente prima dell’acquisizione delle foto aeree utilizzate per l’inventario delle frane del 1976. pertanto, sebbene le immagini utilizzate per i due inventari delle frane siano state acquisite in stagioni generalmente segnate da andamenti delle precipitazioni molto diversi, sia le foto aeree del 1976 sia l’immagine del 2006 sono state acquisite poco dopo periodi piovosi durati alcuni mesi, con condizioni favorevoli al dissesto (in particolare per movimenti superficiali). poichè nelle immagini analizzate si sono riconosciuti come attivi i movimenti franosi avvenuti principalmente nell’ultima stagione piovosa, sono state esaminate le quantità di precipitazioni cadute nei mesi 152 c. lamanna et al. fig. 13 a) andamento delle precipitazioni annue registrate dalla stazione di rocchetta sant’antonio dal 1955 al 2006. b) andamento delle precipitazioni medie mensili ottenute a partire dai dati giornalieri registrati dalla stazione di rocchetta sant’antonio dal 1955 al 2006. a) variation in average yearly precipitation registered in rocchetta s. antonio from 1955 to 2006. b) average monthly precipitation obtained from daily data registered in rocchetta s. antonio from 1955 to 2006. precedenti l’acquisizione delle foto aeree (luglio 1976) e delle immagini ikonos (aprile 2006). considerando il periodo (che include la stagione più piovosa) da ottobre dell’anno precedente alla data dell’acquisizione, i dati registrati sono, per il 1976 e il 2006, rispettivamente di 775 e 580 mm. considerando invece il semestre precedente all’acquisizione, si registrano ripettivamente valori di 421 e 520 mm. e’ stato inoltre effettuato, nei periodi considerati, un confronto tra i principali eventi piovosi, al fine di individuare eventuali particolarità che possano spiegare il considerevole aumento della franosità attiva individuato nelle immagini del 2006. trattandosi di frane essenzialmente superficiali, queste possono essere infatti innescate da precipitazioni di relativamente breve durata. i risultati riportati nella tabella 5 mostrano che nella stagione 1975-76 ci sono stati 5 eventi tra i 40 ed i 60 mm e 2 eventi superiori, con un massimo di 90.8 mm; nella stagione 2005-2006 ci sono stati invece 2 eventi tra i 40 e i 60 mm e 3 eventi superiori, con un massimo di 98.6 mm. la piovosità nei semestri ottobre-marzo precedenti ai cataloghi delle frane è stata valutata anche tenendo conto dell’evapotraspirazione per stimare la quantità di acqua disponibile per il deflusso e per la ricarica idrica del suolo. si è considerato il periodo ottobre-marzo perchè coincide con la stagione della ricarica in cui cioè l’evapotraspirazione potenziale è minore della piovosità media e l’evapotraspirazione potenziale coincide con quella reale. per calcolare l’evapotraspirazione potenziale media giornaliera è stata usata la formula di hargreaves samani (hargreaves & samani, 1982; 1985): ra ep = 0.0023 ––– √ –– td (t + 17.8) λ dove ep = evapotraspirazione potenziale; td = temperatura giornaliera massima meno temperatura giornaliera minima; t = temperatura giornaliera media; ra = radiazione solare extraterrestre, ovvero l’energia che incide giornalmente sulla superficie di un m2 posta orizzontalmente al di fuori dell’atmosfera, (l’effetto della copertura nuvolosa, che riduce la radiazione al suolo, è stimato attraverso l’escursione termica giornaliera); λ = calore latente di evaporazione dell’acqua. se ra è espresso in mj/m2, per ottenere l’evaporazione in mm, λ deve essere espresso in mj/kg (1 kg/m2 = 1 mm di acqua evaporata). si è quindi calcolata la piovosità utile data dalla piovosità meno l’evapotraspirazione potenziale per i semestri ottobre-marzo dei seguenti anni: 19741975, 1975-1976, 2001-2002, 20022003, 2004-2005 e 2005-2006 (fig. 14). si osserva che la piovosità utile nel 1975-1976 e nel 2005-2006 è, rispettivamente, di circa 300 mm e 360 mm. a fronte di una quantità d’acqua disponibile per il deflusso e per la ricarica idrica del suolo di circa il 20% superiore nella stagione 2005-2006 rispetto al 1975-1976, la franosità nel 2006 risulta quasi triplicata. a tale risultato contribuisce presumibilmente anche la differente distribuzione temporale della piovosità complessiva, con un maggior numero di periodi piovosi nel 1976, ma con il 2006 caratterizzato da eventi di intensità superiore. il ruolo scatenante delle precipitazioni è confermato, in misura comunque legata alla differente azione dei fattori predisponenti, tra i quali in particolare l’uso del suolo. 5. discussione e conclusioni questo lavoro ha integrato, sfruttando le potenzialità dell’ambiente gis, dati di diverso tipo e origine. in particolare, la raccolta dei dati necessari per le carte inventario dei fenomeni franosi e per la mappatura dell’uso del suolo in diversi periodi, ha comportato sia l’indispensabile rilievo in sito, sia l’analisi di foto aeree ed immagini satellitari di diverso tipo e con differenti metodologie di trattamento. prima ancora di trarre delle conclusioni riguardanti caratteristiche e cause dell’instabilità dei versanti nell’area di studio, il lavoro suggerisce alcune valutazioni sulle tecniche e metodologie impiegate. in particolare, le immagini satellitari ad alta risoluzione, come quelle del satellite ikonos, si possono considerare una valida alternativa alle foto aeree per la realizzazione di carte 153cambiamenti dell’uso del suolo e aumento dell’attività franosa ... tab. 5 principali eventi piovosi registrati a rocchetta sant’antonio nel periodo antecedente all’acquisizione delle foto aeree del 1976 e all’acquisizione dell’immagine ikonos del 2006. main rainfall events registered in rocchetta s. antonio in the periods preceding the acquisition of 1976 airphotos and 2006 ikonos imagery. 1975-1976 12-21 ott 15-19 nov 11-13 dic 28 gen 9-11 apr 5-8 giu 29 giu-3 lug quantità (mm) 90.8 54.8 84.4 50.2 41.4 40.0 50.8 2005-2006 7-10 ott 9-13 dic 23-28 feb 10-12 mar 22-24 mar quantità (mm) 64.8 77.6 98.6 42.2 43.4 fig. 14 piovosità utile su base mensile (differenza tra piovosità ed evapotraspirazione potenziale) per i periodi ottobre-marzo precedenti l’acquisizione delle immagini usate per produrre le carte inventario delle frane. net monthly rainfall, i.e., the difference between rainfall and potential evapotranspiration for the october-march periods preceding the acquisition of the imagery used to produce landslide inventories. inventario delle frane attive ad una scala di dettaglio, permettendo di cartografare e posizionare con precisione dissesti anche di piccola estensione. fra i vantaggi dell’uso di immagini da satellite, si ha che una singola immagine ricopre grandi aree eliminando quindi la necessità di elaborare fotografie aeree multiple con i problemi collegati, come la necessità di creare mosaici di foto adiacenti a volte acquisite anche a settimane o mesi di distanza. inoltre l’uso di una singola immagine, comprendente una vasta area, riduce significativamente il volume di dati da elaborare per effettuarne l’ortorettificazione. infine, le immagini satellitari possono essere acquisite con tempi di rivisitazione inferiori a quelli necessari a ripetere una campagna aerofotogrammetrica. tuttavia, le immagini satellitari stereoscopiche ad alta risoluzione sono ancora costose rispetto alle immagini aeree e non sono state utilizzate nel presente lavoro. per consentire una visualizzazione tridimensionale le immagini satellitari si sono sovrapposte al dtm; la limitazione nell’interpretazione degli elementi distintivi morfologici dei movimenti di versante inattivi, derivante dalla mancata applicazione della modalità stereoscopica, non è stata eccessivamente penalizzante in questo studio, focalizzato sulle frane attive; tuttavia, la stereoscopia avrebbe verosimilmente permesso un riconoscimento e una mappatura più rapida dei fenomeni franosi, a parità di dettaglio. confrontando le carte inventario delle frane del 1976, del 2005 (risultante da rilievi sul campo) e del 2006 (immagine ikonos) si osserva che in molti casi i movimenti franosi tendono ad avvenire nella stessa area. ciò è in parte dovuto alla presenza di vecchi movimenti che riducono la resistenza al taglio dei materiali coinvolti lungo le superfici di rottura e sviluppano fessure nel terreno che facilitano l’infiltrazione delle acque meteoriche e la saturazione del suolo. tuttavia, il confronto tra i dati del 1976 e del 2006 mostra un deciso incremento dell’attività franosa, con un aumento del 160% della frequenza areale delle frane attive (dal 2% al 5.2%). la tendenza opposta registrata per le frane inattive (che passano dal 7.1% all’1.6%) può essere solo in parte spiegata dalle limitazioni nell’osservazione delle frane inattive dovute alla mancanza del dato stereoscopico nell’immagine ikonos; la percentuale di frane inattive nel 2006 risulta inferiore anche a causa della riattivazione di alcune frane inattive nel 1976. dai rilevamenti effettuati nell’area di studio si può affermare che l’innesco della maggior parte dei fenomeni di dissesto attivi negli ultimi anni ha seguito una serie di inverni piovosi (in particolare le stagioni 20022003 e 2005-2006). e’ quindi possibile individuare nelle precipitazioni un ruolo scatenante sull’instabilità dei pendii gia intrinsecamente “indeboliti” da altre cause. i risultati di questo lavoro mostrano che i cambiamenti dell’uso del suolo nei 30 anni considerati sono ben correlati con l’incremento della frequenza areale delle frane attive nella daunia. nel territorio di rocchetta dal 1976 al 2006 vi è stato un incremento del 46% dei seminativi (dal 52% al 75% dell’area complessiva). le zone alberate sono passate dal 9% nel 1976 al 5% nel 2006; l’allargamento delle aree adibite a seminativo è andato soprattutto a scapito dell’estensione delle aree incolte. l’impatto del cambiamento dell’uso del suolo sulla stabilità dei pendii è facilmente dimostrabile. i terreni divenuti agricoli dopo il 1976 («nuovo seminativo»), registrano un aumento della franosità del 161%, mentre quelli seminati già nel 1976 hanno registrato un incremento della franosità del 181%. tuttavia si osserva come le zone non ancora coltivate nel 1976, e invece adibite in seguito a seminativo, mostrassero già inizialmente una maggiore franosità, e che questa sia cresciuta in proporzione in conseguenza di periodi piovosi come l’inverno 2005-2006. sulle «restanti aree» (non seminate nel 1976 e neppure oggi) l’aumento della franosità dal 1976 al 2006 è stato invece del 98%, nettamente minore rispetto a quello verificatosi sui seminativi. inoltre, si è verificato che l’estensione dei seminativi è avvenuta su terreni con pendenza mediamente superiore a quella dei suoli già coltivati. se nel “vecchio seminativo” (1976) poco più del 25% si trovava su pendenze oltre i 10°, e quasi mai superiori ai 15°, il nuovo seminativo è per il 45% su pendenze oltre i 10°, e per quasi il 10% oltre i 15°. appare quindi chiaro che coltivazioni su pendenze elevate, dapprima marginali, attualmente riguardano porzioni significative del territorio. tutto ciò indica che l’incremento complessivo delle frane attive è stato favorito dall’estensione delle coltivazioni su terreni più ripidi e presumibilmente meno stabili; il «nuovo seminativo» ha occupato aree più franose già prima di essere coltivate (2.9% di area in frana contro 1.8% dei vecchi seminativi come osservato nel 1976). l’aver esteso le coltivazioni ad aree con pendenze più elevate ha ulteriormente aggravato la situazione di pendii già originariamente più instabili. in conclusione, i diffusi fenomeni di dissesto che hanno interessato l’area di studio negli ultimi anni sono stati innescati da precipitazioni superiori alla media. comunque stabilire l’impatto delle variazioni climatiche sulle frane può essere complesso se si considerano pendii modificati dall’uomo, poiché tali modifiche possono sia migliorare che peggiorare la stabilità dei pendii con una rapidità maggiore di quella dei recenti cambiamenti climatici o geomorfologici. sembra inoltre che, nell’analisi preditiva dell’impatto dei cambiamenti climatici sulla franosità, molta attenzione debba essere prestata al periodo immediatamente successivo ad ogni modificazione importante dell’assetto del pendio, sia di origine antropica (es. agricoltura intensiva) che di origine naturale (es. eventi piovosi estremi o terremoti di alta magnitudo). ci sono indicazioni che a seguito di tali modificazioni le soglie di suscettibilità al dissesto possano essere alterate significativamente rispetto a quelle basate sui precedenti dati storici di piovosità e dei dissesti associati alla piovosità stessa (ad es. wasowski, 1998; parise & wasowski, 1999). nella maggior parte dell’area di studio il numero e l’estensione dei fenomeni di dissesto sono da ricondursi a concause determinate dall’intervento antropico. la deforestazione può essere storicamente considerata come uno dei principali fattori che hanno contribuito alla franosità della daunia, così come di altre parti dell’italia meridionale (ad es. parise & wasowski, 2000). inoltre, insieme all’estensione del seminativo su pendenze elevate, seguita alle politiche europee di sostegno alla coltivazione del grano duro attuate dagli anni ’70, vanno considerate le tecniche di aratura e le modificazioni introdotte dalla pratica agricola nella gestione 154 c. lamanna et al. del reticolo idrografico lungo i versanti. le arature con i mezzi meccanici più moderni, in particolare quelli capaci di arature profonde, hanno segnato un ulteriore cambio delle caratteristiche geotecniche, ed un calo della resistenza del suolo. pertanto l’aratura sui pendii più ripidi ed in particolare le nuove arature (che hanno rimosso la vegetazione naturale esistente) che hanno come obiettivo i pendii più ripidi ancora disponibili per l’agricoltura, hanno avuto come risultato una aumentata erosione e franosità superficiale. la stabilità del territorio è stata compromessa anche dall’abbandono di opere di presidio contro l’erosione, create e faticosamente mantenute in passato da generazioni di agricoltori. la frequenza areale delle frane attive ha raggiunto, sulle aree del “nuovo seminativo” con pendenza superiore ai 10°, valori superiori all’11%. la crescita della percentuale di area in frana all’aumentare della pendenza del versante coltivato è molto rapida quando si supera la soglia dei 10°. questo suggerisce un’attenta valutazione dell’opportunità e delle eventuali modalità della pratica cerealicola su tali versanti. oltre che dal rispetto delle norme, tale valutazione non può prescindere dai costi che ricadono sulla collettività, per la messa in sicurezza e il ripristino di dissesti derivanti da un’inadeguata gestione del territorio. ringraziamenti si ringrazia l’amministrazione comunale di rocchetta sant’antonio ed in particolare il dott. a. magnotta, l’ing. g. amoruso e l’ing. g. tedeschi della regione puglia, e il dott. g. rampino per aver fornito alcuni dati usati in questo studio. inoltre si ringraziano il prof. franco loiacono e il dott. paolo giannandrea per le proficue discussioni sulla geologia locale dell’area di studio. infine siamo grati ai due referee anonimi per gli utili suggerimenti fornitici. bibliografia begueria s. (2006) changes in land cover and shallow landslide activity: a case study in the spanish pyrenees. geomorphology, 74, 196– 206. cannon s.h. (2000) debris flow response of southern california watersheds burned by wildfire. in: wieczorek, g.f., naeser, n.d. (eds.), debris flow hazards mitigation: mechanics, prediction and assessment. balkema, rotterdam, pp. 45– 52. ciarcia s., di nocera s., matano f. & torre m. (2003) evoluzione tettono-sedimentaria e paleogeografica dei depocentri “wedge-top” nell’ambito del “foreland basin system” pliocenico dell’appennino meridionale (settore irpino-dauno) boll. soc. geol. it., 122, 117-137. conforti p. (2002) working paper n.14 un’analisi dell’ipotesi di riduzione del sostegno al grano duro nell’unione europea e dei suoi effetti in italia. istituto nazionale di economia agrariaosservatorio sulle politiche agricole dell’unione europea. cotecchia v. (1963) i dissesti franosi del subappenino dauno con riguardo alle strade provinciali la capitanata, 1 (5-6), foggia. crostella a. & vezzani l. (1964) la geologia dell’appennino foggiano boll. soc. geol. it., 83, 121-142. degraff j.v. & canuti p. (1988) using isopleth mapping to evaluate landslide activity in relation to agricultural practices – bulletin of engineering geology and the environment, 38, n.ro 1, 61-71. di nocera s. & torre m. (1987) geologia dell’area compresa tra deliceto e scampitella (appenino foggiano) boll. soc. geol. it., vol. 106, fasc. 2, 351-364. dazzaro l. & rapisardi l. (1987) osservazioni geologiche sull’appennino dauno mem. soc. geol. it., 38, 241-246. dazzaro l., di nocera s., pescatore t., rapisardi l., romeo m., russo b., senatore m.r. & torre m. (1988) geologia del margine della catena appenninica tra il f. fortore ed il t. calaggio (monti della daunia – appennino meridionale) mem. soc. geol. it. 41: 411-422. gisotti e zarlenga (2004) geologia ambientale, principi e metodi. dario flaccovio editore, palermo. glade t. (2003) landslide occurrence as a response to land use change: a review of evidence from new zealand. catena 51, 297– 314. gokceoglu c. & aksoy h. (1996) landslide susceptibility mapping of the slopes in the residual soils of the mengen region (turkey) by deterministic stabil ity analyses and image processing techniques. engineering geology, 44, 147–161. gostelow p. & wasowski j. (2004) ground surface changes detectable by earth observation and their impact on the stability of slopes polish geol. inst. sp. papers 15: 43–52. hargreaves g.h. & samani z.a. (1982) estimating potential evapotranspiration journal of irrigation and drainage engineering, asce, 108 (ir3):223230. hargreaves g.h. & samani z.a. (1985) reference crop evapotranspiration from temperature transaction of asae 1(2):96-99. iovine g., parise m. & crescenzi e. (1996) analisi della franosità nel settore centrale dell’appennino dauno mem. soc. geol. it. 51: 633-641. jacobacci a. & martelli g. (1967) note illustrative del foglio 174, ariano irpino. servizio geologico d’italia, roma. lamanna c. (2008) uso del suolo e franosità nell’appennino dauno tesi di dottorato di ricerca in scienze ambientali, università di bari. malamud b. d., turcotte d. l., guzzetti f. & reichenbach p. (2004) landslide inventories and their statistical properties earth surface processes and landforms 29, 687–711. malatesta a., perno u. & stampanoni g. (1967) note illustrative del foglio 175, cerignola. servizio geologico d’italia, roma. mantovani f., soeters r. & van westen c.j. (1996) remote sensing techniques for landslide studies and hazard zonation in europe. geomorphology 15, 213-225. mehrotra g., kanungo d. & mahadeviah k. (1996) landslide hazard assessment a need for environ155cambiamenti dell’uso del suolo e aumento dell’attività franosa ... mental management. proc. 7th international symposium on landslides, trondheim, norway, pp. 315– 320. mossa s., capolongo d., pennetta l. & wasowski j. (2005) a gis-based assessment of landsliding in the daunia apennines, southern italy proc. intern. conf. “mass movement hazard in various environments” 20-21 october 2005, cracovia, polonia. mostardini f. & merlini s. (1986) appennino centromeridionale. sezioni geologiche e proposta di modello strutturale mem. soc. geol. it., 35, 177202. nichol j. e., shaker a. & wong m. s. (2006) application of high-resolution stereo satellite images to detailed landslide hazard assessment geomorphology 76, 68– 75. parise m. & wasowski j. (1999) use of landslide acivity maps for the evaluation of landslide hazard: three case studies from southern italy natural hazards 20: 159-183. parise m. & wasowski j. (2000) fenomeni di dissesto nell’appennino dauno, ed implicazioni per il patrimonio archeologico e storico-culturale atti convegno geo-ben, torino. polemio m. & casarano d. (2008) climate change, drought and groundwater availability in southern italy geological society, london, special publications 2008; v. 288; p. 39-51. selby m. (1993) hillslope materials and processes. oxford univ. press, oxford. servizio idrografico nazionale (1955-2006) annali idrologici dei bacini con foce al litorale adriatico e ionico dal candelaro al lato sez. idrogr. di bari, fasc. viii, ist. poligr. dello stato, roma. sidle r.c., pearce a.j. & o’loughlin c.l. (1985) hillslope stability and land use. water 608 resources monograph, vol. 11. american geophysical union, washington, dc, 140 pp. soeters r. & van westen c.j. (1996) slope instability recognition, analysis and zonation in a.k. turner & r.l. schuster (eds), landslide investigation and mitigation, nrc, transportation research board special report 247, washington, 129-177. van westen c.j., castellanos e. & kuriakose s.l. (2008) spatial data for landslide susceptibility, hazard, and vulnerability assessment: an overwiev – engineering geology 102: 112-131. wasowski j. (1998) understanding landslide-rainfall relationships in man-modified environments: a case history from caramanico terme (italy) environmental geology 35: 197-209. wasowski j., casarano d. & lamanna c. (2007) is the current landslide activity in the daunia region (italy) controlled by climate or land use change? proceedings of the international conference on landslides and climate change, ventor, isle of wight, uk, 21-24 may 2007, 41-49. wieczorek g.f. (1984) preparing a detailed landslideinventory map for hazard evaluation and reduction bull. int. ass. geol. 3: 337-342. wp/wli (1993) international geotechnical societies’ unesco working party on world landslide inventory. a suggested method for description the activity of a landslide. iaeg bull., 47: 53-57. zezza f., merenda l., bruno g., crescenzi e. & iovine g. (1994) condizioni di instabilità e rischio da frana nei comuni dell’appennino dauno pugliese geologia applicata e idrogeologia, 29: 77-141. 156 c. lamanna et al. ms. ricevuto il 10 novembre 2008 testo definitivo ricevuto il 21 aprile 2009 ms. received: november 10. 2008 final text received: april 21, 2009 amq sn 1 falcucci pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 27 (1), 2014, iii viii report on the 2014 aiqua summer school “la geologia del quaternario applicata allo studio delle faglie attive: dai terremoti alla microzonazione sismica” emanuela falcucci, stefano gori, and the 2014 aiqua summer school participants * istituto nazionale di geofisica e vulcanologia, l’aquila corresponding author: e. falcucci <emanuela.falcucci@ingv.it > abstract: we here summarise the activities carried out during the 2014 aiqua summer school, held from the 29th of september to the 3rd of october at istituto nazionale di geofisica e vulcanologia (ingv) of l’aquila, and supported by ingv-progetto abruzzo. the school aimed at highlighting the major contribution of quaternary geological investigation to the analysis of active and capable faults: this approach involves seismotectonic analysis and surface faulting hazard assessment on faults and deep seated gravitational slope deformations. the participants attended two days of classes, related to those topics, held by experts, and actively and largely joined the discussions raised during the lessons; furthermore, they took part to a three-day fieldtrip in the 2009 l’aquila earthquake area and surroundings. concepts and methods learned during the lessons were applied to selected case studies: these included the 2009 l’aquila earthquake causative fault and other major active normal faults affecting the gran sasso range and the middle aterno river valley. moreover, participants actively took part in still ongoing paleoseismological investigations that aimed at the reconstruction of the recent kinematic behaviour and slip history of the assergi fault, a major active normal fault of the central apennines. keywords: quaternary geology, active and capable faulting, deep seated gravitational slope deformation, paleoseismology, surface faulting hazard, seismic microzonation. active and capable faults and large scale gravitational slope deformations represent geological criticalities that, as elements of surface fragility, can interfere with human development; they must therefore be taken into consideration for seismotectonic analysis and, consequently, for a proper land use planning. these topics were discussed during the 2014 aiqua summer school concerning, in particular, investigation methodologies and hazard assessment. the school took place in the abruzzi region, at the istituto nazionale di geofisica e vulcanologia in l’aquila, from the 29th of september to the 3rd of october. an appreciable number of “students” attended the event: undergraduates and ph.d. students, postdoctoral fellows, researchers and freelance geologists, from central and southern italy, and one coming from great britain. during the first two days, lessons were held by experts in active tectonics, quaternary geology, paleoseismology, neotectonics, earthquake geology, seismic microzonation. they lectured with laudable enthusiasm (and without remuneration!). they held high-value classes and stimulated discussion among the participants on the different topics mentioned above, some of which are presently a matter of debate in the scientific community, especially with regard to surface faulting hazard assessment. the speakers thoroughly emphasised the importance of “old-school” geological survey, which lays the foundation for a multi-methodological approach in active and capable faulting analyses. we warmly thank all the lecturers for their irreplaceable contribution to the success of the school! monday, september 29 the first day of the school was opened by dr. andrea sposato who, as a senior member of aiqua, spoke on behalf of aiqua itself, thanking all of the participants and lecturers for taking part to the summer school; he emphasised the importance of such events in increasing the awareness of the fundamental role of quaternary geology in active tectonics analysis, especially as for young scientists and students. then, the ingv-progetto abruzzo was presented by its scientific coordinator dr. gianluca valensise who, together with ingv-l’aquila branch manager, dr. fabrizio galadini, supported the aiqua event. after these introductive talks, a series of scientific classes began with dr. paolo messina, who illustrated general aspects of quaternary geological investigations and their contribution to the reconstruction of tectonic and paleoenvironmental history of the central apennines. dr. fabrizio galadini gave a lecture on the role of quaternary geological investigations on active and capable faulting studies; his lesson was also dedicated to the definition of time intervals to assess the notion of “active and capable faults” for engineering practices in * domenico berti, fabrizio brutto, tamara carducci, antonio cefalì, edi chiarini, silvia crosetto, fabrizio cultrera, paolo di marcantonio, federica durante, pasquale evangelista, giandomenico fubelli, biagio giaccio, michele lancia, francesca liberi, lorenzo lo sardo, serena madonna, gianmarco mondati, marco moro, giuseppe napoli, francesco pavano, michele saroli, stefania silvestri, andrea sposato, fabrizio tinelli, domenico trotta italy. dr. daniela pantosti focused on general and methodological aspects of paleoseismological analysis, showing several case studies all over the world, and highlighting the effectiveness of such investigations for seismic hazard assessment. dr. gianluca valensise illustrated the italian database of individual seismogenic sources (diss); he also showed some examples of peculiar geological features that mimic active faulting, and other cases where the relation between active faults at surface and seismogenic structures at depth can be complicated by the inheritance of older tectonic structures. ing. maria basi explained the role and task of the abruzzi region local government in the seismic microzonation studies of the whole region (fig. 1a). dr. paolo boncio gave a lecture on the criteria to define zones of surface fault-rupture hazard; he illustrated the new guidelines – currently underway – for surface fault rupture zonation in italy that are still a matter of interest and debate within the italian scientific community and the italian governmental institutions. dr. paolo galli illustrated the state of the art of paleoseismological investigations in italy, showing some recent examples of such analyses along italian major active normal faults. dr. alberto pizzi showed the most recent outcomes of ongoing seismic microzonation studies of the town of facucci e. & gori s. iv fig. 1 lessons held during the first two days of the summer school; a) ing. maria basi illustrates microzonation studies presently ongoing in the abruzzi region, b) dr. marco moro shows the re-activation of large scale gravitational slope deformation during the 1997 colfiorito earthquake. fig. 2 fieldtrip – visit to the paleoseismological trenches dug across the assergi fault. v report on the 2014 aiqua summer school fig. 3 fieldtrip – moments of the lunch at campo imperatore, waiting for “arrosticini” to be cooked. fig. 4 fieldtrip – the group discusses on the campo imperatore active fault strands. mt. brancastello in background, through the clouds. sulmona, in the abruzzi region: he outlined the geological factors that influence local seismic response and the issue of active and capable faulting affecting the sulmona territory. tuesday, september 30 the second day of lessons began with dr. marco tallini, who illustrated the results of seismic microzonation studies carried out in l’aquila after april, 2009, in the difficult post-earthquake framework; he examined all of the geological complexities needed to be understood and unraveled. dr. nicola tullo showed the role of freelance geologists in the ongoing seismic microzonation studies in the abruzzi region. dr. marco moro gave two lectures: the former about general aspects of deep seated gravitational slope movements and their relation with active tectonics; the latter focused on the use of satellite radar interferometry and paleoseismological techniques to investigate the kinematic behaviour and mechanics of large scale gravitational mass movements. he showed different case studies of large scale mass wasting that had been reactivated during large magnitude seismic events occurred in italy during the past decades (among which the 2009 l’aquila earthquake) (fig. 1b). dr. stefano gori illustrated, through case studies selected over the central apennines, the role of quaternary geological field analysis in demonstrating the inactivity of tectonic structures despite the presence of misleading morphological hints suggesting activity. the last talks introduced the fieldtrips: dr. biagio giaccio reported a comprehensive picture of the quaternary geological evolution of the paganica village area where, the activation of the normal fault causative of the 2009 earthquake caused surface fault rupture. dr. emanuela falcucci illustrated the quaternary geological evolution of the middle aterno river valley and of the subequana valley, and their relation with the long term kinematic evolution of the active normal faults that affect the eastern borders of these intermontane depressions. dr. stefano gori and dr. marco moro illustrated the present knowledge about the activity of the assergicampo imperatore fault system, where paleoseismological trenches, shown during the first day of the fieldtrips, have been dug. they also showed the structural and tectonic complexities that characterise the southwestern flank of the gran sasso range, resulting from the interference between active extensional faults and inactive thrust faults inherited by the presently inactive compressive regime. wednesday, october 1 on the first day, the fieldtrip was spent along the assergi active normal fault. two paleoseismological trenches dug across the central part of the fault – made ad-hoc for the summer school – were visited. the walls of the excavations were observed, analysing evidence of the recent fault movements and searching for elements that give information about its slip history (fig. 2). we moved, then, to the fossa di paganica tectonic depression, located along the southern portion of the assergi fault. here, geomorphological evidence of the recent activity of the tectonic structures was analysed in the light of the results coming from paleoseismological investigations, which were recently performed along this part of the fault (moro et al., in prep.). after a wonderful and pleasant lunch, where the participants experienced and made practice in the art of cooking “arrosticini” (accompanied by more than one glass of red wine!!) (fig. 3), the fieldtrip continued in campo imperatore highland, specifically focusing on glacial and peri-glacial deposits exposed along the plain and on the active normal faults pattern that affects the area (fig. 4). during the last part of the afternoon, some of the closed tectonic depressions that characterise the southwestern flank of the gran sasso range were visited, with a particular focus on the bounding fault scarps; the evidence of recent activity of these structures was discussed, together with their tectonic “significance” in the complex structural framework of the mountain front. furthermore, geomorphic evidence of the occurrence of large scale gravitational slope deformation along the gran sasso southwestern flank was shown. thursday, october 2 the first half of the fieldtrip on the second day was led along the paganica fault, whose activation determined the april 6, 2009 seismic event. in particular, the vi fig. 5 fieldtrip – dr. biagio giaccio describes middle pleistocene tephra layers contained in alluvial sediments displaced by the paganica fault. facucci e. & gori s. site of the water main that had been damaged by the fault activation was visited, analysing the quaternary (and late pleistocene-holocene) deposits displaced by some secondary fault planes exposed along the main fault scarp, in the area of paganica. evidence of activation of the paganica fault during seismic events preceding the 2009 one was examined. alluvial fan and fluvial deposits containing middle pleistocene tephra layers and displaced along the fault were analysed in detail (fig. 5). during the afternoon, a fault plane exposed at the southern termination of the paganica fault, in poggio picenze, was observed, described and analysed; the structure brings into contact lacustrine and alluvial deposits. then, evidence for the late quaternary activity of one of the northernmost segments of the middle aterno valley fault was illustrated near corbellino: fluvial-lacustrine deposits are affected by a complex shear zone, synthetic to the main fault scarp; as a consequence of the fault movement, they were placed in contact with slope deposits. the day ended with beers, teas, juices, snacks and laughters in san demetrio ne’ vestini. friday, october 3 the last fieldtrip focused on the middle aterno valley-subequana valley fault system. the participants enjoyed a wonderful panoramic view of the scarp of the roccapreturo fault segment from the village of goriano valli (fig. 6). the roccapreturo fault scarp is one of the most impressive fault scarplets of the central apennines. evidence for the quaternary and late pleistoceneholocene activity of the roccapreturo segment was illustrated and described in more detail in the village of roccapreturo: there, the tectonic structure brought in to contact the carbonate bedrock, cropping out on the footwall, with late pleistocene-holocene deposits, exposed at the base of the fault scarp. the stop was followed by the description of the quaternary morpho-stratigraphic and tectonic evolution of the subequana valley. in particular, some fault planes related to the subequana valley fault were shown in the vii report on the 2014 aiqua summer school fig. 6 fieldtrip – dr. emanuela falcucci describes the middle aterno valley fault system. fig. 7 fieldtrip – dr. giandomenico fubelli describes one of the active fault plane that crosses castelvecchio subequo. area of castelvecchio subequo (fig. 7). evidence of the displacement of middle pleistocene fluvial deposits and of late pleistocene slope sediments along these faults were analysed in detail. the organisers emanuela falcucci and stefano gori warmly thank all the participants for the days spent together and for the more than pleasant company! everyone was extremely friendly, active and interested, and the mood was always overjoyed and superb!! the organisers consider the summer school experience as extremely positive, a cultural and human growth, and they hope this will not be the last “stop” but the first of many other similar initiatives !! viii facucci e. & gori s. ms. received: october 26, 2014 final text received: november 16, 2014 ix amq34(2) 213-235 terlato et al def immrid.pdf available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 34 (2), 2021, 213-235 late neanderthal subsistence at san bernardino cave (berici hills northeastern italy) inferred from zooarchaeological data. gabriele terlato1,2, valentina lubrano2, matteo romandini2,3, ana b. marín-arroyo1,4, stefano benazzi3,5, marco peresani2,6,7 1 grupo de i+d+i evoadapta, dpto. ciencias históricas. universidad de cantabria, spain. 2 dipartimento degli studi umanistici, sezione di scienze preistoriche e antropologiche, università degli studi di ferrara, italy. 3 dipartimento di beni culturali, università di bologna, italy 4 department of archaeology, university of cambridge, uk 5 department of human evolution, max planck institute for evolutionary anthropology, germany. 6 istituto di geologia ambientale e geoingegneria, cnr, italy. 7 accademia olimpica, vicenza, italy. corresponding author: m. peresani <marco.peresani@unife.it> abstract: north-eastern italy is a key region for the study of neanderthal way of life over a wide timeframe, as attested by over 20 middle palaeolithic multi-layered sites in caves, rock shelters and at open-air sites. here we contribute to increase our understanding of neanderthal subsistence strategies through the study of the faunal assemblage of unit ii dated to the first half of marine isotopic stage 3 (mis3), from san bernardino cave. the site is located in the berici hills, at low altitude near the edge of a karstic plateau dissected by valleys and delimited by the alluvial lowland. zooarchaeological and taphonomic analyses suggest that neanderthal groups were the primary agent for the accumulation of mammal remains, and that hunting mainly focused on ungulates, such as cervus elaphus and capreolus capreolus. forested environment sustained by mild climatic conditions is also inferred by micromammals evidence. our data suggest a selective transport of the prey even for the roe deer which might have implied a long distance transportation from the site. also, it might have been related to the age of the prey or to multiple preys hunted in a single episode. the bayesian method applied to the analysis of skeletal profiles shows a high level of attrition at the site and a greater degree of processing appendicular skeleton. neanderthals used san bernardino cave as a place where carcasses processing was finalized, after an initial process at the kill-site, and then prepared for consumption. also, discarded bones were used for lithic manufacturing. the san bernardino evidence can be compared with productive systems for exploiting available ungulate game from other regional-scale mis 3 middle palaeolithic sites. keywords: neanderthal subsistence, middle paleolithic, mis 3, northeastern italy, zooarchaeology. 1. introduction one of the main issues to fully understand how neanderthals were able to survive for more than 250,000 years across eurasia is the reconstruction of their diet and subsistence strategies. studying the fauna remains helps to determine anthropogenic behaviour and to accurately understand the subsistence and adaptation patterns used to exploit different ecological niches (stiner, 1994; bocherens, 2009; ready, 2010; gaudzinski-windheuser & roebroeks, 2011; morin et al., 2016; jaouen et al., 2019). however, subsistence behaviour presents specific differences and adaptations between geographical areas and sites, highlighting the importance of the availability and richness of nearby biotopes as much as the functionality of the settlements. zooarchaeological evidence attests, for example, the exploitation of small game, birds, and aquatic resources (brown et al., 2011; cortés-sánchez et al., 2011; blasco & fernández peris, 2012; cochard et al., 2012; blasco et al., 2013; fiore et al., 2016; gómez-olivencia et al., 2018; nabais, 2018; morin et al., 2019; marín el al., 2019; zilhão et al., 2020; guillaud et al., 2021 among others), alongside with the predation and consumption of bears (romandini et al., 2018a). despite this broad diet spectrum, the neanderthals’ main animal protein sources were medium and large-sized herbivores. in general, in late middle paleolithic contexts, undisputable records had proven how neanderthals targeted, butchered and consumed a wide variety of ungulates (patoumathis, 2000; fiore et al., 2004; costamagno et al., 2006; rendu, 2010; rosell et al., 2012; ready, 2013; salazar-garcía et al., 2013; yravedra & cobo-sánchez, 2015; sanz et al., 2019). such scenario does not exclude continental and peninsular italy, where, in recent years, new information about late neanderthal groups’ subsistence behaviour and mobility has been acquired (boscato et al., 2011; peresani, 2011; romandini et al., 2014, 2018a, 2018b, 2020a; fiore et al., 2016; boscato, 2017; holt et al., https://doi.org/10.26382/amq.2021.10 214 terlato g. et al. 2019; moroni et al., 2019; terlato et al., 2019; spagnolo et al., 2020; peretto et al., 2020), thus providing more data on these issues. notably, in the north of italy archaeologists uncovered a considerable number of rock shelters and caves yielding evidence of human occupation during middle and late pleistocene (peresani, 2011; margaritora et al., 2020). these sites are settled within the ecological corridor bounded by the apennine, alpine and dalmatian mountain ranges and the adriatic sea. such a peculiar geographic location is crucial for the understanding of regional differences in mammals’ acquisition and exploitation by neanderthals. despite the abundance of archaeological sites, only few of them yielded animal bones. moreover, not all of them have been analysed with a consistent zooarchaeological approach to assess everywhere the taphonomy, mortality patterns, skeletal profiles, carcass transport, carnivore activities, and so on (fiore et al., 2004; miracle, 2005; thun-hohenstein, 2006; romandini et al., 2014, 2018a, b, 2020a; thun-hohenstein et al., 2018; terlato et al., 2019). this lack of data limits analytical comparisons of neanderthal strategies at a regional and at a larger scale. thus, within such a discontinued and fragmented framework, new zooarchaeological studies are crucial to provide new data on neanderthal groups’ subsistence. to further contribute to the diet and subsistence patterns achieved by neanderthals in southern alps foreland during late mis3, we present the analysis of the faunal assemblage of unit ii of san bernardino cave. this cave was excavated during 1960 and 1986-95 and displayed a cultural sequence rich in lithic implements and faunal remains. we have focused on taxonomical representation, prey selection, skeletal part representations and carcass processing in order to define the site functionality and to compare it with other sites from the regional context. 2. san bernardino cave in the mis 3 landscape 2.1. the subalpine area of the southeastern alps: physical and ecological setting san bernardino cave lies in the foreland of the eastern italian alps. this mountain range represents a physical and environmental threshold where ice fields and alpine glaciers developed during cold stages of the middle and late pleistocene, and where temperate vegetation restored during warm phases. the alpine foreland is a vast alluvial plain originated since the middle pleistocene from the po and adige rivers, other minor waterways, and the ones of the friulian-venetian plain (fontana et al., 2014). concerning this latter, the area also includes hills of different geological origins, like the berici hills and the cone-shaped volcanic reliefs of the euganean hills, which were separated by the spreading outwash of the plain. the berici hills are a karstic plateau with a maximum altitude of 440 m a.s.l., a honeycomb of sinkholes and depressions shaping an extremely uneven topography, scattered by rock peaks and blocks affected by surface dissolution. the plateau is dissected by depressed systems (e.g., the fimon, liona, and calto valleys) characterised by pocketvalleys where ephemeral streams produced swampy environments and fed historic mills. the slopes are steep all around. to the east, a steep slope with rock cliffs connects the plateau to the alluvial lowlands that were occupied by marshes and swamps during the pleistocene and most of the holocene (monegato et al., 2011). to the west, the plateau gradually connects to the plain. ecological conditions during the first half of mis3 recorded the presence of open birch-conifer forests, xerophytic scrubs and steppe. episodes of conifer forests contraction and steppe communities expansion were documented, in alternation with mixed conifer (pinus and picea) betula forests (pini et al., 2009, 2010) and with reduced warm-temperate component (tilia) which however persisted up to ca. 40 ka (pini et al., 2010; badino et al., 2020). rainfall and humid conditions in the southeastern alpine foreland favored by the glaciated alps have also been confirmed by micromammal assemblages in the berici hills at broion cave and san bernardino cave and in the monti lessini area at fumane cave (lópez-garcía et al., 2015, 2017, 2019). 2.2. san bernardino cave san bernardino cave is situated on the eastern slope of the berici at 135 m above sea-level, facing the alluvial plain of bacchiglione river and the western side of the euganean hills (fig. 1). besides san bernardino, other middle palaeolithic caves and shelters open in the same area: broion cave and broion rockshelter (peresani et al., 2019; romandini et al., 2020b), de nadale cave (jéquier et al., 2015; livraghi et al., 2021), paina cave (bartolomei et al., 1987-88). san bernardino cave is 41 m long, 7 m wide and 9 m high and originated from the widening of deep, se-nw oriented fractures produced by thermoclastic processes and chemical dissolution. the natural morphology of san bernardino has been modified along time. the cave was used as a hermitage since medieval times and settled by members of the franciscan order. during the late middle ages or even afterwards prehistoric deposits were partly dismantled by the construction of a wall sealing the entrance of the cave, as also attested by a modern human tooth dated to 1420-1480 cal ad (benazzi et al., 2014a). all along the modern age, the inner cavity was almost totally emptied from the quarrying of the infill. after the discovery of pleistocene bones (fabiani, 1902-03), the first phase of archaeological investigations was coordinated by p. leonardi in the sixties in the medieval wall facing area. the excavations uncovered a pleistocene sequence with faunal remains and lithic industries (leonardi, 1958-1959; leonardi & broglio, 1960-1961). a second phase in the excavation was coordinated by a. broglio and m. peresani between 1986 and 1995, allowing to re-examine the stratigraphic series from the inner and the outer zones (peresani, 1995-1996). the deposit is a complex sedimentary body shaped like an elongated prism, extending from inside to partly outside the cave. it is a remnant of the lower part of the sediments that originally filled the cave. at present, the sedimentary sequence is 4.5 m thick and includes eight stratigraphic units with sub-horizontal bedding, which gradually bend outside the cave (fig. 2). these record the succession of three main paleoclimatic 215 late neanderthal subsistence from zooarchaeology at san bernardino cave cycles shifting from temperate to dry/cold conditions: cycle 1 (mis 7c/b mis 6, units viii to vii); cycle 2 (mis 5d and b mis 4, units v to iv) and cycle 3 (mis 3 mis 2? units iii to i) (cassoli & tagliacozzo, 1994; lópez-garcía et al., 2017). u/th and esr dates range from the middle/late pleistocene (units viii-vii, ca. 214 and 154 ka; gruppioni, 2003; picin et al., 2013) to the late pleistocene for unit ii: 52±5 ka bp, 38±5 ka bp and 33±5 ka bp (peresani, 2001). in addition to a first radiocarbon date at >40ka bp produced in the nineties (peresani, 2001), two new dated bones, one of a bos/ bison (sb42) and another one of a large cervidae (alces/megaloceros) (sb918), both with anthropogenic marks from unit ii, yielded >48.6 ka bp (oxa-40121) and 45.9±2900 ka bp (oxa-40203) (tab. 1). thus, they confirmed that the archaeological content is not younger than the first half of mis 3. a osl dating program is ongoing to support the chronological layout of the sedimentary sequence from unit viii up to unit iv. unit ii, the focus of this paper, is situated at the entrance of the cave and was totally excavated over an area of 20 sqm extending below the medieval wall as well. unit ii (fig. 2) thickens up to 40 cm, it includes different sublayers named 1, 2, 3, 4a, 4b and 4c, and it records an increase in the density of anthropogenic evidence faunal remains, lithic artefacts, and hearths in comparison with the underlying units iii, iv and v. a previous taxonomic study of the macromammal association (cassoli & tagliacozzo, 1994) showed the presence of a broad variety of mammal species such as roe deer, red deer, moose, wild boar and bovines (terlato et al., 2019), while cave bear was the most abundant carnivore. taphonomic analysis of a restricted sample of large ungulate bones, revealed traces of disarticulation, defleshing and the use of bone fragments as retouchers (malerba & giacobini, 1998). lithic industry in unit ii is featured by intensive exploitation of local and exogenous chert, responsible for reduction in size of cores, flakes and retouched tools. flake-manufacture was based on the exclusive application of recurrent unidirectional and centripete levallois modalities (peresani, 1996; porraz & peresani, 2006). moreover, although many tools were shaped at the cave, a significant number of them had been introduced at different stages of reduction. it has been hypothesized that such exploitation might be linked to long-term fig. 1 geographical location of san bernardino cave in north-eastern italy. tab. 1 new radiocarbon dates from unit ii of san bernardino cave. pm: percussion marks; cm: cut marks. ber of individuals) (klein & cruz-uribe, 1984; grayson, 1984; lyman, 1994) and mau (minimum animal units) (binford, 1984). %mau was calculated by dividing each mau by the highest mau value of the assemblage. a 100% representation of all body parts would infer the presence of complete animal bodies. the assemblage diversity was then examined through the inverse of simpson’s index. this index measures both the richness (n-types) and evenness (proportionality) of the kind of prey characterizing the diet (simpson, 1949). the lower the resultant value, the more the assemblage involved is dominated by a single taxon and a narrow diet (magurran, 1988). for regional comparison of hunting preferences, correspondence analysis was employed. to evaluate the prey transport strategies and the intensity of the subsequent attrition, bivariate correlations between %mau and different indices (binford, 1978; metcalfe & jones, 1988; marín-arroyo, 2009a; morin & ready, 2013) were applied: %mau and mgui (modified general utility index binford, 1978), fui (food utility index metcalfe & jones, 1988), cfui (corrected food utility index morin & ready 2013) to define strategies employed in the use or transport of animal carcass; %mau and maximum bone density (lam et al., 1999) to assess the influence of destructive processes in the faunal assemblage. in order to determine if the bone breakage patterns were the result of marrow extraction, correlations between %mau and the marrow index (binford, 1978) were calculated. in addition, %mau of the high survival elements was correlated with the unsaturated marrow index (umi) proposed by morin (2007). spearman’s coefficient of correlation was used to test the quantitative validity of these correlations and to determine the level of statistical significance (p) thereof. furthermore, to overcome the limitations of previous indices to evaluate the skeletal profiles and attrition at the site, a bayesian approach was applied (marín-arroyo & ocio, 2017). this method considers two parameters, alpha (α) and beta (β), that are active during the formation of the assemblage. the former, transport preference (α), can take any value between -1 (>axial contribution) and 1 (>appendicular contribution) based on butchering efficiency in skeletal elements. the latter, degree of attrition (β), which follows the definition established by rogers (2000 a, b), and relates the survivorship of bone element to their maximum bone density. this method aims specifically to overcome the problem of equifinality in skeletal profile interpretations, analysing two factors simultaneously. animals’ age at death was estimated on the basis of the time of eruption, the replacement of teeth, and the degree of dental wear, as well as the stage of the bone epiphyseal fusion. habermehl (1961), aitken (1974), mariezkurrena (1983), azorit et al (2002), d’errico & vanhaeren (2002) and tomé and vigne (2003) were used for calculating the age of cervus elaphus and capreolus capreolus. once the age at death was determined, individuals were grouped into five age groups: i (infant animals with deciduous teeth), j (juvenile lightly worn deciduous teeth and erupted m1); subad (sub-adult animals with moderately worn deciduous teeth and erupted m2); ad (adult all erupted permahuman occupations (peresani, 1995-1996). most of these artefacts were made of finely textured chert collected in the surroundings (1-5 km), together with chert of similar quality supplied from farther sources (15-20 km) in the euganean hills up to the central-western monti lessini (80 km) (peresani, 1996). levallois end and by-products were shaped in a wide range variety of retouched tools, like simple, double and convergent scrapers, while transverse scrapers were made from cortical, centripetal levallois flakes and other flakes (peresani, 1995-1996). denticulates and points sorted in different forms and sizes (peresani, 1995-1996; picin et al., 2010, 2013), in contrast, are rare. the attribution of levallois technology and/or mousterian tools to late neanderthals exploiting this region during mis 3 is proven by the association with human remains from fumane cave (benazzi et al., 2014b), broion rockshelter (romandini et al., 2020b) and tagliente rockshelter (arnaud et al., 2016). 3. materials and methods our analysis concerned the bone assemblage from unit ii. the remains were recovered during fieldwork carried on in 1959-1964 (bartolomei, 1960) and 19861995 (broglio & peresani, 1992), using a main grid of one square meter divided in nine smaller squares. sediments were wet sieved through superimposed mesh from 5 to 0.5 mm. the faunal remains were systematically recovered in situ during the excavation process and after wet-sieving the sediments. following cassoli & tagliacozzo’s taxonomical study (1994) and a preliminar taphonomical observation (malerba & giacobini, 1998), a zooarchaeological re-examination of bovids remains and a first analysis of small mammal bones were performed by terlato et al. (2019) and romandini et al. (2018b) respectively. each of these works used the same methodological approaches for taphonomy studies to evaluate the whole assemblage. overall, 9,429 faunal remains were scrutinized for this analysis. the complete alpine fauna reference collection of the section of prehistoric and anthropological science at university of ferrara and barone’s (1976) reference were used for taxonomic identification and for anatomical nomenclature, respectively. in order to include in the study bones that could not be identified taxonomically by any diagnostic landmark, all the remains have been grouped into four weight sizes classes, based on the modification of the criteria proposed by bunn (1986): (1) small-sized mammals weighing <20 kg (lagomorphs, rodents and small carnivores); (2) medium-sized animals weighing between 20 and 100 kg (i.e. caprids, capreolus capreolus, sus scrofa, canis lupus); (3) medium-large sized animals weighing between 100 and 300 kg (i.e. cervus elaphus, ursidae; panthera pardus); (4) large animals weighing >300 kg (i.e. alces alces, megaloceros giganteus, large bovids). the identified elements were quantified using the following measures: nr (number of remains); nisp (number of identified specimens) (grayson, 1984); mne (minimum number of elements) has been counted considering side, body size and ontogeny (klein & cruz-uribe, 1984; binford, 1984); mni (minimum num 216 terlato g. et al. guished by those made by carnivores (coil et al., 2020) according to diagnostic characteristics: ventral face with point of detachments and bulb; greater breadth than length; absence or reducing of cortical surface. burnt damages were recorded in terms of presence/absence (naked eye) and into three colour stages (stiner et al., 1995): mainly brown (lightly burnt), black (carbonized), grey to white (calcinated). carnivore marks were classified as follows: pits, scores, punctures, furrowing, gnawing and corrosion of gastric acid (fisher, 1995; domínguez-rodrigo & piqueras, 2003; domínguezrodrigo & barba, 2006). finally, the study of bone retouchers was carried out following mallye et al., (2012) and mozota holgueras (2012). 4. results 4.1. bone assemblage the analyzed assemblage consists of 9,421 remains of mammals, three of fish and five of birds, which correspond to 52 different individuals and 22 taxonomic groups (tab. 2). among them, 15.9% were identified nent teeth with any or moderate wear); s (old adult or senile very advanced wear on most of the crown). the type of cortical tissue (compact in adults or more porous in young animals) was also used on the isolated diaphysis fragments. to determine the effects of biostratinomical (both hominins and carnivores) and postdepositional processes, breakage type and surface modification were treated at both macroscopic and microscopic level. when necessary, microscopic analyses of bone surfaces were carried out using a leica s6d greenough stereomicroscope with 0.75-70x magnification range, also employed for capturing images. for each faunal remain, we systematically recorded the different taphonomic alterations, including those made by rodents, carnivores or hominins, as well as climatic and edaphic modifications (water abrasion, concretion, root marking, trampling, chemical corrosion and manganese oxide coating. for the purpose of identifying these main taphonomical modifications we used the criteria established by behrensmeyer (1978), binford (1981), lyman (1994), blumenschine et al., (1996), fernández-jalvo & andrews (2003, 2016) (among others). trampling marks were distinguished from butchering marks using the works of blasco et al. (2008) and domínguez-rodrigo et al. (2009). evidence of anthropogenic modification observed on the faunal remains includes cut-marks, intentional bone breakage and burning. cut-marks have been recognised and grouped into incisions and scraping marks (binford, 1981; potts & shipman, 1981; shipman, 1981; shipman & rose, 1984; lyman, 2008; galán et al., 2009; vettese, 2014). the analysis of cut-marks took into account the number of striations, their location and distribution (isolated, clustered, crossed) and orientation (longitudinal, transverse and oblique) on the bone. by using these cut-marks criteria, it was possible to interpret the specific butchering activities (binford, 1981; fisher, 1995; nilssen, 2000). the causes of fractures were investigated analysing the type and the angle of fracturing (fresh-green or old-dry) (villa & mahieu, 1991) together with structural and surface damage, such as percussion notches, pits, impact flakes and adhering flakes (blumenschine & selvaggio, 1988; capaldo & blumenschine, 1994; pickering & egeland, 2006; galán et al., 2009; pickering et al., 2013; vettese et al., 2017, 2020). impact flakes have been defined and distin 217 late neanderthal subsistence from zooarchaeology at san bernardino cave fig. 2 above: today’s entrance of the cave after the restoration. below: stratigraphic section. unit ii visible on the section is a remnant of the layer extended over the cave entrance and completely excavated during the 1959-1964 and 1985-1993 fieldworks. 218 terlato g. et al. tab. 2 total number of skeletal remains (nr), number of identified specimens (nisp) and minimum number of individual (mni) found in san bernardino ii. anatomically and taxonomically. 84.1% were determined as generic mammals and sorted into weight size classes (tab. 2). a considerable amount of remains (nr=5,030, 53.3%) results to be indeterminate anatomically, taxonomically and by weight size class. five mammal orders including perissodactyla, artiodactyla, carnivora, lagomorpha, rodentia have been identified. ungulates (80.5% of nisp) are the most numerous one, represented by stephanorinus sp., megaloceros giganteus, alces alces, cervus elaphus, capreolus capreolus, bos primigenius, capra ibex, rupicapra rupicapra and sus scrofa. carnivores remains (nisp=235, 15.6%) correspond to ursus arctos, ursus spelaeus, canis lupus, vulpes vulpes, panthera pardus, lynx lynx, felis silvestris, mustela putorius, martes sp. lagomorphs and rodents (nisp=50, 3.3%) are represented by lepus sp., marmota marmota and castor fiber (tab. 2). these data confirm previous results obtained by cassoli & tagliacozzo (1994). due to the high fragmentation and the massive presence of diaphysis, it was challenging to precisely distinguish amongst the genera bos and bison and the species alces alces and megaloceros giganteus. for this reason, most of the remains were generically assigned to the category bos/ bison sp. and in a broad group of medium/large cervidae, which is also the case for many other contemporaneous sites. according to the nisp and mni data, the faunal assemblage is clearly dominated by cervids with capreolus capreolus and cervus elaphus as the most representative. since the roe deer represents most of the identified remains (nisp=253), it is not surprising that non identifiable bone remains assigned to medium sized animals are also the most abundant (nr=1,937, 20.5%) (tab. 2). the estimation of the age at death of 219 late neanderthal subsistence from zooarchaeology at san bernardino cave tab. 3 number of mammals remains showing butchering marks, thermal-alterations and carnivore marks. cm: cut-marks; pm: percussion marks; cm+pm: cut-marks + percussion marks; % bm: % butchering marks; ret.: retouchers; b: burned-black/brown bones; c: calcined-grey/white bones; car.: carnivore marks. the ungulates indicates a predominance of adult individuals (mni=19, 63.3%), followed by juveniles (mni=5, 16.6%) and old individuals (mni=4, 13.3%) (tab. 2). based on the analysis of dental eruption and replacement sequences, it was possible to estimate the season of death of young individuals; no foetal remains were preserved. this involves two roe deer and one wild boar. for capreolus capreolus one germen of m2 (erupt around 6-8 months habermehl, 1961) allows us to define the season of death during the end of autumn. on the other hand, two decidual premolar (one dp3 and one dp2) with marked wear attest that one individual died in spring. in the same way, seasonality indicates that the wild boar died in autumn. we identified a variety of species among the carnivore remains (tab. 2). ursids are the most abundant, while ursus spelaeus (nisp=101) is better represented than ursus arctos (nisp=3). for a total of 100 remains (ursus sp.), mostly fragments of isolated teeth and extremities of limb bones, it was not possible to precisely ascribe their taxonomy to either ursus arctos or ursus spelaeus. cave bear is represented with at least one individual for each age range, from infant to senile (tab. 2). data concerning the sex identification of animal remains are scarce, due to the high fragmentation that limited the presence of sexual diagnostic elements and the acquisition of characteristic biometric data. despite a general lack of diagnostic skeletal part, a few observations can be made. the presence of two antler fragments of roe deer suggests at least that one male is present in the assemblage. we applied the criteria proposed by d’errico & vanhaeren (2002) to three upper canines of cervus elaphus to distinguish the age and sex. however, due to the high fragmentation of remains it was not possible to determine the sex. finally, the presence of a bear’s baculum shows that one male individual is present. 4.2. general taphonomic observations assemblage from san bernardino cave is highly fragmented (98.1%). complete elements are extremely rare (1.9% of the whole assemblage is complete) and they mostly correspond to isolated teeth (16.8%) and small fat bearing bones (70.6%) such as carpals, tarsals, sesamoids and phalanges. low-density bone por 220 terlato g. et al. fig. 3 position and details of anthropogenic traces: (a) right ulna of castor fiber with skinning marks; (b) right mandible of megaloceros giganteus with cut-marks on the medial side; (c) metatarsal of alces alces with scraping marks; (d and e) femur diaphysis of cervids with scraping marks and close-up of the area used as a retoucher; (f) isolated flakes produced by percussion activity. genic breakage (tab. 3). these are mainly percussion notches and impact flakes, whereas percussion pits are rare and peeling was not recorded. we identified only one adhering flake on a giant deer bone. the damaged elements are mainly the long bones of generic ungulates and red deer. within the indeterminate bone assemblage, percussion marked remains are mostly observed on largeand mediumsized animals. the distribution, orientation and types of cut-marks (cm) provide evidence of different butchering activities. the most common types of cut-marks were incisions indicating skinning, disarticulation, defleshing and periosteum removal. in addition, scraping marks related to periosteum removal were also identified. the taxonomic groups showing cut-marks are beaver, bears and all the main ungulate species, accounting for 4.1% (nr=62) of the total nisp. three bones of castor fiber bear cut-marks (fig. 3a); romandini et al., 2018b). one right ulna shows three longitudinal incisions suggesting possible skinning (fig. 3a). clustered, short, and oblique incisions on iii and v metatarsals could be related to the removal of tendons of the hindlimb and the recovering of the hide. amongst carnivores, only ursus spelaeus and ursus sp. present remains with anthropogenic modifications. butchering traces have been observed on two portions of fibula and one portion of femur and could be related to defleshing and disarticulation. all the main ungulate species have been processed (tab. tions (ribs, sternum, vertebra fragments, scapula) and teeth are scarce (4.7% and 4.8%) and related to long-shaft fragments, which play a significant role altogether (38.5%). epiphyses are underrepresented (1.3%), and spongy bone fragments (<1%) are also scarce. ungulates remains are complete in only 7% of cases. crania, mandibles and long bones are always fragmented. the fractures analysis shows that long bones of over 3 cm mostly were broken when green, and especially by oblique, curved and smooth fractures. 28.9% of carnivore remains are complete. all the complete elements, namely teeth, metacarpals, metatarsals, and phalanges belong to bears, red fox and lynx. lagomorpha and rodentia remains are complete in 36% of cases, mostly represented by metatarsals and phalanges of beaver and marmot. overall, we observed an excellent preservation of the bone surface. among the biostratinomic modifications, we identified trampling abrasion (14.9%), root marks (9.7%), and micro-fissures from weathering and/or weathering cracks (1.9% of the total). 83% of the bones displays diagenetic alterations and manganese dendrites, while some remains show concretion (2.9%) and rare chemical corrosion (0.2%). rodents gnawing marks were detected only on 0.2% of the bones. carnivore modifications are extremely scarce and only affect 0.6% (nr=58) of the specimens (tab. 3). pits, scores and gnawing tooth marks on the diaphysis of large-sized animals are the main alterations. no corrosion attacks made by carnivore digestion were detected. only one cave bear bone shows furrowing traces that could be related to canids activity in terms of taxa, bear bones recorded the highest rate of tooth marks (22.4%), followed by chamois (8.6%). the frequency of remains with carnivore marks by weight class shows that medium-large and large sized animals were the most affected (17.2%; 10.3%). carnivore marks were observed only on few medium animals’ remains (nr=3). 4.3. anthropogenic modifications anthropogenic modifications observed in the sample include several butchering traces, bone breakage, cut-marks (1.7% of nr) and burn damage (57.7% of nr) (tab. 3). 83 remains (50.6% of nr with human traces) present percussion marks (pm) from intentional anthropo 221 late neanderthal subsistence from zooarchaeology at san bernardino cave fig. 4 frequency of skeletal elements of cervus elaphus and capreolus capreolus and distribution of anthropogenic modifications. 222 terlato g. et al. 3; fig. 3) and provide the best record for inferring human subsistence at san bernardino unit ii. anthropogenic traces were found mostly on cervids, but also on large bovids (terlato et al., 2019), caprids and wild boar remains. cut-marks are preserved on three bones of megaloceros giganteus. one hemi-mandible fragment bears longitudinal and oblique incisions. these are located on the medial side, under the second and third molars, and could be associated with the dismembering or removal of the tongue (fig. 3b). incisions aiming to meat procurement, together with percussion notches and adhering flake were recognized on one tibia. finally, one radius/ulna shows long and longitudinal incisions which might be related to defleshing. evidence of alces alces skinning is suggested by one metatarsal fragment, which also present scraping marks for periosteum removal and percussion notch for marrow extraction (fig. 3c). rupicapra rupicapra remains include one metatarsal fragment with skinning marks and one tibia shaft fragment with short, repeated, and oblique incisions that might hint at defleshing. only one first phalanx of sus scrofa yields cut-marks. cervus elaphus and capreolus capreolus are the taxa bearing most of the neanderthal induced modifications. despite the non-homogeneous presence of their skeletal parts, the exploitation of these animals is attested for all the anatomical elements in the assemblage (fig. 4). traces of human activities ascribed to dietary and non-nutritional purposes can be observed over all the anatomical parts. for cervus elaphus, 17 remains are characterized by butchering traces (tab. 3, fig. 4). each long bone of the limbs shows cut-marks, with the forelimbs (humerus, radius and metacarpal) being more intensely subjected to these human modifications, whereas only the first and the second phalanges of the extremities of the limbs present traces of this kind of alterations. cut-marks suggest defleshing (long, sparse, oblique and longitudinal incisions and scrapings, fig. 5a, c) and the cutting off of insertions of muscles and tendon (short, repeated, transfig. 5 position and details of anthropogenic modifications on some skeletal elements of cervus elaphus: (a) left radius/ulna with incisions marks and pits produced during knapping on diaphysis; (b) right femur with close-up of different cut-marks; (c) left metapodial with scraping marks. 223 late neanderthal subsistence from zooarchaeology at san bernardino cave verse and/or slightly oblique incisions, fig. 5b). both these actions mostly affected the diaphysis of the long bones. skinning (longitudinal, oblique, isolated and/or clustered) is equally well documented on the phalanges (first and second). often, different anthropogenic modifications can be observed on the same bone. for instance, one radius/ulna of cervus elaphus shows cutmarks related to defleshing and scraping aimed to the removal of the periosteum, before the bone was used for retouching (fig. 5a). concerning capreolus capreolus remains, cutmarks have been recorded on 8 bones (tab. 3, figs. 4 and 6) and they are gathered mainly on the extremities of the hindlimb: 4 metatarsal, 2 phalanges and 1 tibia. cut-marks on the metatarsal and phalanges are associated with skinning (fig. 6). the latter is also suggested by oblique cut-marks on buccal surface of one mandible. one tibia fragment bears short and transverse incision ascribed to filleting. for both species intentional bone breakage is attested by a series of percussion marks, including notch marks and percussion pits. following the analysis of percussion marks, we can observe that marrow access activity is more intense in red deer limbs. however, it is noteworthy that not only long bones were broken but even phalanges (both first and second) were exploited to get access to the marrow. deliberate fragmentation has been inferred on five phalanges of cervus elaphus and on three of capreolus capreolus. in most of them, we observed longitudinal breakage pattern as well. modifications caused by fire concerned more than half of the total specimens (57.7%): 50.6% were affected by moderate combustion (brown/black), while 7.1% were calcinated (grey/white) (tab. 3). the burnt specimens account for 21.5% of nisp and include elements from all anatomical regions and ungulate categories. roe deer is the most affected taxon by burn damage (35.1% of roe deer nisp), followed by red deer (24.4% of red deer nisp). in both cases, burnt autopodium elements outnumber other anatomical elements (fig. 4). finally, within the whole assemblage, twelve bone shafts were used as hammers for retouching flint artifacts. the retouchers were manufactured from metapodials, radius, femurs and tibia. most of them show traces of cut-marks and they belonged to large-sized herbivores, likely medium/large cervids (figs. 3d, 3e, 4 and 5a; terlato et al., 2019). 4.4. skeletal part representation of cervus elaphus and capreolus capreolus carcass transport strategy was only inferred for cervus elaphus and capreolus capreolus, as they yielded the most abundant data (tab. 4, fig. 7). %mau shows a clear predominance of the limbs over the axial skeleton elements (tab. 4). the anatomical distribution is characterized by a significant presence of phalanges and sesamoids followed by frontal and hind limbs bones (humerus, radius/ulna, metacarpals, femur, tibia and metatarsals). cranium is mainly represented by isolated teeth and fragmented parts of the mandible, maxilla and antler. the axial skeleton is almost absent, with only one portion of red deer’s rib. the two species do not present any considerable difference between forelimbs and hindlimbs representation. conversely, some dissimilarities can be detected in terms of nisp between the limb bones, among which metacarpals and metatarsals are fig. 6 position and details of anthropogenic modifications on some skeletal elements of capreolus capreolus: a-b) metatarsal with longitudinal cut-marks; (c) left second phalange with close-up of skinning incision. 224 terlato g. et al. tab. 4 nisp (number of identified specimens), mne (minimum number of elements), mau and %mau (minimum animal unit) of cervus elaphus and capreolus capreolus. 225 late neanderthal subsistence from zooarchaeology at san bernardino cave fig. 7 percentage of minimum anatomical units of cervus elaphus and capreolus capreolus tab. 5 correlation between %mau and mgui (modified general utility index), fui (food utility index), cfui (corrected food utility index), umi (unsaturated marrow index), grease, meat, marrow and bone density indices of cervus elaphus and capreolus capreolus. 226 terlato g. et al. always the most represented elements (tab. 4). the results of the differential transport strategies adopted by neanderthal groups for cervus elaphus and capreolus capreolus are presented in tab. 5. considering red deer, the bivariate correlations between %mau with mgui, fui and cfui are negative (ρ=-0.03, ρ=0.15, ρ=-0.06) and not significant (p=0.88, p=0.54, p=0.81). with regard to roe deer, the correlation between %mau with mgui is negative (ρ=-0.29) and not significant (p=0.17); with the food utility indexes (both fui and cfui) the correlations are positive (ρ=0.11 and ρ=0.15) and not significant (p=0.65 and p=0.54). %mau and meat index is negative for both cervids (ρ=-0.23 and ρ=-0.53), however it is not-significant for red deer (p=0.29) and significant for roe deer (p=0.01). for both species, %mau with grease, marrow and umi indexes are positively (ρ=0.47, ρ=0.67, ρ=0.81 ρ=0.41, ρ=0.61, ρ=0.31 respectively) and significantly correlated (p<0.05), except for roe deer’s umi that is not significantly correlated (p>0.05). %mau with bone density is positively and significantly correlated for both species (ρ=0.55, ρ=0.45 and p=<0.05). finally, no significant correlations were found between the bone density and utility indexes for both species. transport decision privileged anatomical parts rich in grease and marrow (mainly long bones, including metacarpals and metatarsals) to exploit them at the site (fig. 8). the results of the bayesian model for the evaluation of the prey transport strategies (α) are 0.33 and 0.35 for cervus elaphus and for capreolus capreolus, and the attrition at the assemblage (β) (fig. 9, tab. 6) are 6.43 and 6.34, respectively. these data indicate carrying prey strategy for both taxa of the appendicular skeleton (α median values) and very high attrition at the level (β median values). the β median index with values of 6, implies that more than 95% of the original record would have disappeared (tab. 6). the high attrition would explain the imperceptible representation of low dense elements. the results of correspondence analysis, in addition to a significant level of attrition, attest a greater degree of appendicular skeleton processing for both species. fig. 8 correlation between % mau and marrow index of cervus elaphus and capreolus capreolus. tab. 6 alpha parameter (skeletal transport) and beta parameter (attrition) of cervus elaphus and capreolus capreouls, and interpretation of the bayesian model. and the few remains of fishes and birds (ducks and geese) (cassoli & tagliacozzo, 1994; fiore et al., 2004) suggest humid environments and watercourses in the proximity of the site. finally, the importance of castor fiber remains is given by the peculiar environmental conditions it lives in, always associated with flowing water. these data are consistent with a recent study of the micromammal associations, which highlights the 5. discussion the zooarchaeological data acquired through our analysis allow the reconstruction of neanderthal subsistence economy and ecological exploitation during the first half of mis 3 at san bernardino cave. the taxonomic consistency of the faunal remains, dominated by the ungulates, especially cervids, as well as the taphonomic bone modifications and its association with lithic tools (peresani, 1996), support the anthropic origin of the assemblage, occasionally disturbed by biological agents other than humans. 5.1. palaeoenvironmental implications from macromammals the faunal spectrum shows the presence of a broad variety of species, mostly represented by ungulates such as large bovids, large and medium-sized cervids, caprids, and wild boar, but also some carnivores, leporids and rodentia, associated with scant remains of fish and birds. regarding the ecological context, the faunal assemblage from san bernardino ii is representative of diverse past environments inhabited by humans. in fact, the site surroundings consisted of close and open forests with transitive and discontinuous alpine grasslands or sparse vegetation on carbonate rocks, completed by a humid environment and watercourses. the dominance of red deer and roe deer over other taxa may reflect that forests were commonly the neanderthals’ most exploited hunting environment. however, caution is needed in declaring this assumption given the ecological plasticity of these kind of deers, which can live in different ecosystems. the roe deer primary habitat is forest clearings, hedges, and woodland edge (danilkin, 1996). furthermore, red deer can inhabit variable environments, from open steppe to close temperate forest (geist, 1999). besides, the wild boar remains reveal the existence of woodlands close to san bernadino cave. moreover, the exploitation of large bovids is representative of ecological conditions diversity, spanning from dense forests with wetlands and small streams ecologically, more attractive to bos primigenius, to hilly grasslands and plains populated by bison (terlato et al., 2019). still, rhinoceros, moose, beaver 227 late neanderthal subsistence from zooarchaeology at san bernardino cave fig. 9 α and β parameters from cervus elaphus and capreolus capreolus 228 terlato g. et al. presence of microtus agrestis and apodemus gr. sylvaticus-flavicollis as the most abundant species in unit ii, thus demonstrating mild and humid conditions in a landscape dominated by woodland formations (lópezgarcìa et al., 2017). 5.2. subsistence economy it must be mentioned that, despite the varied environmental range that existed around the cave, which were the habitat of the prey species, the inhabitants of the site may not had spent equal time foraging in these different patches. taxonomic data demonstrate that the majority of mammals remains carried to the site belonged to prey typical of woodlands, valley bottoms and lowlands. the paucity of large prey types within the assemblage, might be explained with a lower encounter rates than red deer and roe deer’s one, or, perhaps, they were disregarded when the hunters’ success rate were lower than the ones for smaller prey species (bird et al., 2009). on the other hand, while small/medium ungulates, like chamois and ibex, might have a higher rate of capture due to their marked attitude for living in herds compared to wild boar or roe deer’s ones for instance-, they were less frequently encountered than red deer and roe deer (marín-arroyo, 2009b; romandini et al., 2014). it is also possible that ungulates typical of rocky landscapes or highlands were in part excluded from the diet but used as an alternative food source when the higher-ranked game was less abundant. furthermore, it seems that mountain habitat areas were not widespread nearby the cave. san bernardino is not a unique example of neanderthal subsistence, as other late middle palaeolithic settlements in the fringe of sub-alpine area show similarities with it. this is the case of tagliente rockshelter (thun-hohenstein & peretto, 2005; thun-hohenstein, 2006) and fumane cave (cassoli & tagliacozzo, 1991; fiore et al., 2004; romandini et al., 2014, 2020a; peresani et al., 2017). qualitative and quantitative data reveal that the types of hunted ungulates at each site are compliant with their respective environmental and climatic conditions. at tagliente, layers 35-37, the most common species to have been brought into the site are roe deer and red deer, while ibex and chamois are less common. at fumane, units a5-a6 and a9, hunting targeted different species, primarily red deer, roe deer and large cervids of all age classes, with a lesser incidence of chamois, ibex, large bovids (peresani et al., 2011; romandini et al., 2014) and to birds (fiore et al., 2016; romandini et al., 2016). to further analyse the diet breadth in terms of diversity, we measured the inverse of simpson's index, which takes into account both richness and evenness, as shown in tab. 7. san bernardino, fumane unit a9 and tagliente share a similar pattern for hunted species. the nisp values are quite lower in relation to animal. on the other hand, mni index is higher and it identifies the diversification of species consumption. hence, this framework confirms that selective hunting was undertaken by humans in order to target game availability in the surroundings of the site. 5.3. hunting strategies and site functionality at san bernardino cave, humans were the principal agents of the faunal assemblage. occasionally, other predators scavenged neanderthals’ leftovers, as attested by the low percentage of carnivore gnawing marks found on bone surfaces. this situation suggests a secondary access to the remains for carnivores, which therefore did not significantly contribute to bone accumulation after or before human activities. hunting practices targeted different species. in particular, clear traces of anthropogenic intervention have been documented on three remains of castor fiber’s bones, related to fur recovering (romandini et al., 2018b). nevertheless, cave bear is the only carnivore species presenting few remains with anthropogenic modifications. infant or very young and senile cave bears show a differentiated occupation of the cave by humans and bears, as also recorded in late middle paleolithic sites in northern italy, such as fumane cave, rio secco cave among others (romandini et al., 2018a). as a matter of fact, ungulates were the most exploited animals. cervids, mostly deer and roe deer adult specimens, were the most hunted animals. yet, the presence of two young, one sub-adult, four adult and two senile individuals of c. capreolus reflects the age structure of natural populations, thus confirming the hypothesis for the exploitation of whole herds. seasonality information inferred by roe deer hunting season, allowed to esteem that the site occupation likely occurred during summer and autumn. on the other hand, the absence of fetal and neonatal individuals suggests that the site was not frequented in spring. nevertheless, seasonality studies are still lacking a more complete documentation. for this reason, the acquisition of more detailed data based on isotopes, microwear analysis and cemento chronology is needed to provide further information. the neanderthals used san bernardino as a place where, after an initial preparation at the kill-site, carcasses processing and consumption activities were carried out; still, discarded bones were used for lithic manufacturing. this is revealed by the skeletal profile analyses achieved with the correlation indices and the bayesian method for cervus elaphus and capreolus capreolus. as a matter of fact, it seems that neanderthal groups carried to the site appendicular body parts, by selecting the anatomical parts with higher nutritional content (both marrow and meat) and economic values, even for roe deer with a smaller body size than red deer. hence, the high significant statistical correlations between %mau and grease, marrow and umi likely identifies a preference for bones transportation related to their grease and marrow content, except for roe deer, for which no statistab. 7 san bernardino, fumane and tagliente ungulates diversity results based on the inverse of simpson’s index (1/d) according to nisp values. adata from romandini et al., 2014; bdata from thun-hohenstein 2006. 229 late neanderthal subsistence from zooarchaeology at san bernardino cave tical correlation with unsaturated marrow index (umi) was detected. cut-marks, scraping, burning, percussion marks and fresh fractures are present, without any significant difference in both animals. moreover, the correlation between the fracture degree and the marrow index has confirmed the intense exploitation of within-bone nutrients, even in the case of phalanges. in fact, phalanges exploitation for marrow extraction is due to its taste and soft texture. the marrow present in the phalanges is known for its better taste because of its high content of unsaturated fatty acids, compared to other long bones (morin, 2007). we demonstrated that the extremely high attrition of the bones in this cave could be related to the selective transport of the prey and to the intensive human activity. the latter consisted in the abovementioned process and the employ of butchering refuse, rich in fats, used as fuel for fires or living floor maintenance (costamagno et al., 2009, 2010; morin, 2010). the absence of vertebrae and ribs, together with other low-survival elements could also be due to such reasons (marín et al., 2017). considering the differential carcass transport, even though a considerable attrition within the assemblage affected less dense skeletal elements, it might be inferred that neanderthal groups maximized the caloric input of the hunted prey brought to the cave. such decisions might depend on several factors, including the weight of both red deer and roe deer carcass portions, the distance between the kill/prime butchering site and the camp base, the daytime of the hunting episode, the number of hunters involved, and so on (mnahan, 1998; marín-arroyo, 2009a; schoville & otárola-castillo, 2014). moreover, the number of hunted animals and the competition with other carnivores in the environment, must not be excluded either. san bernardino cave’s topographic location low altitude, close to the edge of a karstic plateau dissected by deep valleys and delimited by the alluvial lowlands supported the exploitation of the prey recognized. at the same time, its position required significative efforts to cover distance in the landscape. likely, carrying patterns of red deer and roe deer did not exceed 5-7 km from the site, underpinning an intentional focus on local resources. additionally, knappable raw materials for stone tools were available in the surroundings. nevertheless, large bovids’ remains and the presence of exogenous raw materials also suggest that longerdistance movements did occur (peresani, 1996). 6. conclusion zooarchaeology and taphonomic analyses, thanks to their capability of characterising human economic behaviour and its relationship between human-animal and environmental exploitation, is currently one of the most widely used approaches to understand human strategies. macrofaunal data from san bernardino cave provide new insights regarding animal exploitation and butchering practices during the late middle palaeolithic in continental italy. the faunal spectrum reveals that site occupation generally occurred with temperate conditions, suggesting a forest landscape interspersed with clearings and wetlands. still, our results have shown that, despite the high attrition of the assemblage, neanderthal subsistence strategies at san bernardino cave were mostly based on ungulates exploitation, especially red deer and roe deer, whereas the procurement of large ungulate and small chamois was sporadic. neanderthal groups adopted a notable degree of energetic efficiency in carcasses processing, with a quite selective transport of red deer and roe deer. all this evidence highlights additional aspects of neanderthal landscape use, hunting strategies and mobility in north-eastern italy, where eastern italian alps’ ecosystems and forelands offered a wide range of opportunities in terms of animal resources, to sustain neanderthal populations approaching the edge of their demise. acknowledgements excavations and studies at san bernardino cave are coordinated by the university of ferrara (m.p.) and supported by the ministry of cultural affairs and tourism and veneto archaeological superintendency (sabapverona, vicenza and rovigo), public institutions (veneto region department for cultural heritage, province of vicenza, municipality of mossano). author contributions: m.p. conceived research; v.l., g.t. and m.r. analysed data; a.b.m.a. supported new radiocarbon dating; s.b. and m.r. are supported by the erc-cog horizon 2020 project success (ref 724046 website: http://www.erc -success.eu/); g.t. and m.p. wrote the paper with inputs from a.b.m.a., m.r. and s.b. the authors want to acknowledge lucía agudo pérez for graphic support. radiocarbon dating has been funded by the erc-cog horizon 2020 project subsilience (ref 818299 website: https://www.subsilience.eu/) led by a. b. marínarroyo. references aitken r.j. (1974) delayed implantation in roe deer (capreolus capreolus). journal of reproduction and fertility, 39, 225-233. arnaud j., peretto c., panetta d., tripodi m., fontana f., arzarello m., thun hohenstein u., berto c., sala b., oxilia g., salvadori p.a., benazzi s. (2016) a reexamination of the middle paleolithic human remains from riparo tagliente, italy. quaternary international, 425, 437-444. azorit c., analla m., carasco r., calvo j.a., muñozcobo j. (2002) teeth eruption pattern in red deer (cervus elaphus hispanicus) in southern spain. anales de biologia, 24, 107-114. badino f., pini r., ravazzi c., margaritora d., arrighi s., bortolini e., figus c., giaccio b., lugli f., marciani g., mongato g., moroni a., negrino f., oxilia g., peresani m., romandini m., ronchitelli a., spinapolice e., benazzi s. (2020) an overview of alpine and mediterranean palaeogeography, terrestrial ecosystems and climate history during mis 3 with focus on the middle to upper palaeolithic transition. quaternary international, 551, 7-28. barone r. (1976) anatomie comparée des mammifères domestiques. tome 1: ostéologie. vigot, 230 terlato g. et al. paris. italian edition, pp. 690. bartolomei g. (1960) nota preliminare sulla fauna della grotta maggiore di san bernardino nei colli berici (vicenza). annali università ferrara, iii (7), 119-125. bartolomei g., broglio a., cattani l., cremaschi m., lanzinger m., leonardi p. (1987-88) nuove ricerche nel deposito pleistocenico della grotta di paina sui colli berici (vicenza). atti dell’istituto veneto di scienze, lettere e arti, cxlvi, 112-160. benazzi s., peresani m., talamo s., fu q., mannino m.a., richards m.p., hublin j.j. (2014a) a reassessment of the presumed neandertal human remains from san bernardino cave, italy. journal of human evolution, 66, 9-94. benazzi s., bailey s.e., peresani m., mannino m.a., romandini m., richards m.p., hublin j.j. (2014b) middle paleolithic and uluzzian human remains from fumane cave, italy. journal of human evolution, 70, 61-68. behrensmeyer a.k. (1978) taphonomic and ecologic information from bone weathering. paleobiology, 4 (2), 150-162. binford l.r. (1978) nunamiut etnoarchaeology. academic press, new york, pp. 530. binford l.r. (1981) bones, ancient men and modern myths. academic press, new york, pp. 320. binford l.r. (1984) faunal remains from klasies river mouth. academic press, new york, pp. 305. bird d.w., bliege bird r., codding b.f. (2009) in pursuit of mobile prey: martu hunting strategies and archaeofaunal interpretation. american antiquity, 74, 3-29. blasco r., rosell j., fernández peris j., cáceres i., vergès j.m. (2008) a new element of trampling: an experimental application on the level xii faunal record of bolomor cave (valencia, spain). journal of archaeological science, 35(6), 1605-1618. blasco r., fernández peris j. (2012) a uniquely broad spectrum diet during the middle pleistocene at bolomor cave (valencia, spain). quaternary international, 252, 16-31. blasco r., rosell j., fernández peris j., arsuaga j.l., bermúdez de castro j.m., carbonell e. (2013) environmental availability, behavioural diversity and diet: a zooarchaeological approach from the td10-1 sublevel of gran dolina (sierra de atapuerca, burgos, spain) and bolomor cave (valencia, spain). quaternary science reviews, 70, 124-144. blumenschine r.j., selvaggio m.m. (1988) percussion marks on bone surfaces as a new diagnostic of hominid behavior. nature, 333, 763-765. blumenschine r.j., marean c.w., capaldo s.d. (1996) blind tests of interanalyst correspondence and accuracy in the identification of cut marks, percussion marks, and carnivore tooth marks on bone surfaces. journal of archaeological science, 23, 493-507. bocherens h. (2009) neanderthal dietary habits: review of the isotopic evidence. in: the evolution of hominid diets: integrating approaches to the study of palaeolithic subsistence (ed. by hublin j.j., richards m.). springer, new york, 241-250. boscato p. (2017) ambienti ed economia nel paleolitico medio della puglia: lo studio delle faune. in: preistoria e protostoria della puglia (ed. by radina f.). studi di preistoria e protostoria 4, 119-124. boscato p., gambassini p., ranaldo f., ronchitelli a. (2011) management of paleoenvironmental resources and raw materials exploitation at the middle paleolithic site of oscurusciuto (ginosa, southern italy): units 1 and 4. in: neanderthal lifeways, subsistence and technology one hundred fifty years of neanderthal study (ed. by conard n.j., richter j.). vertebrate paleobiology and paleoanthropology series, springer, new york, 87-98. broglio a., peresani m. (1992) grotta di san bernardino (comune di mossano, vicenza). rivista di scienze preistoriche xliv, 234-235. brown k., fa d.a., finlayson g., finlayson c. (2011) small game and marine resource exploitation by neanderthals: the evidence from gibraltar. in: trekking the shore. interdisciplinary contributions to archaeology (ed. by. bicho n., haws j., davis l.). springer, new york, 247-272. bunn h.t. (1986) patterns of skeletal representation and hominid subsistence activities at olduvai gorge, tanzania, and koobi fora, kenya. journal of human evolution, 15, 673-690. capaldo s.d., blumenschine r.j. (1994) a quantitative diagnosis of notches made by hammerstone percussion and carnivore gnawing on bovid long bones. american antiquity, 59, 724-748. cassoli p.f., tagliacozzo a. (1991) considerazioni paleontologiche, paleoeconomiche e archeozoologiche sui macromammiferi e gli uccelli dei livelli del pleistocene superiore del riparo di fumane (vr) (scavi 1988-91). bollettino museo civico storia naturale verona, 18, 349-445. cassoli p.f., tagliacozzo a. (1994) i resti ossei di macromammiferi, uccelli e pesci della grotta maggiore di san bernardino sui colli berici (vi): considerazioni paleoeconomiche, paleoecologiche e cronologiche. bullettino di paletnologia, 85, 1-71. cochard d., brugal j.p., morin e., meignen l. (2012) evidence of small fast game exploitation in the middle paleolithic of les canalettes aveyron, france. quaternary international, 264, 32-51. coil r., yezzi-woodley k., tappen m. (2020) comparisons of impact flakes derived from hyena and hammerstone long bone breakage. journal of archaeological science, 120, 105167. cortés-sánchez m., morales-muñiz a., simón-vallejo m.d., lonzano-francisco m.c., vera-peláez j.l., finlayson c., rodríguez-vidal j., delgado-huertas a., jiménez-espejo, f.j., martínez-ruiz f., martínez-aguirre m.a., pascual-granged a.j., bergadà-zapata m.m., gibaja-bao j., riquelmecantal j., lópez-sáez j.a., rodrigo-gámiz m., sakai s., sugisaki s., finlayson g., fa d.a., bicho n.f. (2011) earliest known use of marine resources by neanderthals. plos one, 8 (12), e81476. costamagno s., meignen l., cédric b., bernard v., bruno m. (2006) les pradelles (marillac-le-franc, 231 late neanderthal subsistence from zooarchaeology at san bernardino cave france): a mousterian reindeer hunting camp? journal of anthropological and archaeology, 25, 466-484. costamagno i., théry-parisot i., castel j.c., brugal j.p. (2009) combustible ou non? analyse multifactorielle et modèles explicatifs sur des ossements brûlés paléolithiques. in: gestion des combustibles au paléolithique et au mésolithique: nouveaux outils, nouvelles interprétations (proceedings of workshop 21, xv congress iuspp, lisbonne, 2006) (ed. by théry-parisot i., costamagno s., henry a.). bar international series 1914, archaeopress, oxford, 65-84. costamagno s., théry-parisot i., kuntz d., bon f., mensan r. (2010) impact taphonomique d’une combustion prolongée sur des ossements utilisés comme combustible. in: taphonomie des résidus organiques brûlés et des structures de combustion en milieu archéologique (ed. by théry-parisot i., chabal l., costamagno s.). palethnologie, 2, 173187. d’errico f., vanhaeren m. (2002) criteria for identifying red deer (cervus elaphus) age and sex from their canines. application to the study of upper palaeolithic and mesolithic ornaments. journal of archaeological science, 29, 211-232. danilkin a. (1996) behavioural ecology of siberian and european roe deer. chapman & hall, london, pp. 300. domínguez-rodrigo m., piqueras a. (2003) the use of tooth pits to identify carnivore taxa in tooth-marked archeofaunas and their relevance to reconstruct hominid carcass processing behaviours. journal of archaeological science, 30, 1385-1391. domínguez-rodrigo m., barba r. (2006) new estimates of tooth mark and percussion mark frequencies at the flk zinj site: the carnivore-hominidcarnivore hypothesis failed. journal of human evolution, 50, 170-194. domínguez-rodrigo m., de juana s., galán a.b., rodríguez m. (2009) a new protocol to differentiate trampling marks from butchery cut marks. journal of archaeological science, 36, 2643-2654. fabiani r. (1902-03) la fauna fossile della grotta di san bernardino nei colli berici. atti istituto veneto ss.ll.aa., lxii, 657-671. fernández-jalvo y., andrews p. (2003) experimental effects of water abrasion on bone fragments. journal of taphonomy, 1, 147-163. fernández-jalvo y., andrews p. (2016) atlas of taphonomic identifications. vertebrate paleobiology and paleoanthropology. springer, dordrecht, pp. 372. fiore i., gala m., tagliacozzo a. (2004) ecology and subsistence strategies in the eastern italian alps during the middle palaeolithic. international journal of osteoarchaeology, 14, 273-286. fiore i., gala m., romandini m., cocca e., tagliacozzo a., peresani m. (2016) from feathers to food: reconstructing the complete exploitation of avifaunal resources by neanderthals at fumane cave, unit a9. quaternary international, 421, 134-153. fisher w.j. (1995) bone surface modifications in zooarchaeology. journal of archaeological method and theory, 2, 7-68. fontana a., mozzi p., marchetti m. (2014) alluvial fans and megafans along the southern side of the alps. sedimentary geology, 301, 150-171. galán b., rodríguez m., de juana s., domínguezrodrigo m. (2009) a new experimental study on percussion marks and notches and their bearing on the interpretation of hammerstone-broken faunal assemblages. journal of archaeologial science, 36, 776-784. gaudzinski-windheuser s., roebroeks w. (2011) on neanderthal subsistence in last interglacial forested environments in northern europe. in: neanderthal lifeways, subsistence and technology one hundred fifty years of neanderthal study (ed. by conard n.j., richter j.). vertebrate paleobiology and paleoanthropology series, springer, new york, 61-71. geist v. (1999) deer of the world. swan hill press, shrewsbury, england, pp. 432. gómez-olivencia a., sala n., núñez-lahuerta c., sanchis a., arlegi m., rois-garaizar j. (2018) first data of neandertal bird and carnivore exploitation in the cantabrian region (axlor; barandiaran excavations; dima, biscay, northern iberian peninsula). scientific reports, 8, 10551. grayson d.k. (1984) quantitative zooarchaeology: topics in the analysis of archaeological faunas. academic press, orlando, pp. 202. gruppioni g. (2003) datation par les méthodes uranium-thorium (u/th) et resonance paramagnetique electronique (rpe) de deux gisements du paléolithique moyen et supérieur de vénetie: la grotta de fumane (monts lessini verone) et la grotte majeure de san bernardino (monts berici vicence). ph.d. dissertation, university of ferrara. guillaud e., béarez p., daujeard c., defleur a.r., desclaux e., roselló-izquierdo e., morales-muñiz a., moncel m.h. (2021) neanderthal foraging in freshwater ecosystems: a reappraisal of the middle paleolithic archaeological fish record from continental western europe. quaternary science reviews, 252, 106731. habermehl k. h. (1961) die altersbestimmung bei haustieren, pelztieren und beim jagdbaren wild. paul parey verlag, berlin, 223 pp. holt b., negrino f., riel-salvatore j., formicola v., arellano a., arobba d., boschian g., churchill s.e., cristiani e., di canzio e., vicino g. (2019) the middle-upper paleolithic transition in northwest italy: new evidence from riparo bombrini (balzi rossi, liguria, italy). quaternary international, 508, 142-152. jaouen k., richards m.p., le cabec a., welker f., rendu w., hublin j.j., soressi m., talamo s. (2019) exceptionally high δ15n values in collagen single amino acids confirm neandertals as hightrophic level carnivores. pnas, 11, 4928-4933. jéquier c., peresani m., romandini m., delpiano d., joannes-boyau r., lembo g., livragi a., lópezgarcía j.m., obradovic m., nicosia c. (2015) the de nadale cave, a single layered quina mousteri 232 terlato g. et al. an site in the north italy. quartär, 62, 7-21. klein r.g., cruz-uribe k. (1984) the analysis of animal bones from archaeological sites. university of chicago press, chicago, pp. 304. lam y.m., chen x., pearson o.m. (1999) intertaxonomic variability in patterns of bone density and the differential representation of bovid, cervid, and equid elements in the archaeological record. american antiquity, 64(2), 343-362. leonardi p. (1958-1959) risultati della prima campagna di scavo della stazione musteriana di s. bernardino nei colli berici (vi). atti istituto veneto ss.ll.aa., 117, 387-402. leonardi p., broglio a. (1960-1961) le paléolithique de la vénetie. annali università di ferrara, 15(1), 1-118. livraghi a., fanfarillo g., dal colle m., romandini m., peresani m. (2021) neanderthal ecology and exploitation of cervids at the onset of mis4: a study on de nadale cave, italy. quaternary international, 586, 24-41. lópez-garcía j.m., dalla valle c., cremaschi m., peresani m. (2015) reconstruction of the neanderthal and modern human landscape and climate from the fumane cave sequence (verona, italy) using small-mammal assemblages. quaternary science reviews, 128, 1-13. lópez-garcía j.m., luzi e., peresani m. (2017) middle to late pleistocene environment and climatic reconstruction of human occurrence at grotta maggiore di san bernardino (vicenza, italy) through the small-mammal assemblage. quaternary science reviews, 168, 42-54. lópez-garcía j.m., berto c., peresani m. (2019) environmental and climatic context of the hominin occurrence in northeastern italy from the late middle to late pleistocene inferred from small-mammal assemblages. quaternary science reviews, 216, 18-33. lyman r.l. (1994) vertebrate taphonomy. cambridge university press, cambridge, pp. 552. lyman r.l. (2008) quantitative paleozoology. cambridge university press, cambridge, pp. 348. magurran a.e. (1988) ecological diversity and its measurement. princeton university press, princeton, pp. 192. malerba g., giacobini g. (1998) les restes fauniques du paléolithique moyen de la grotte de san bernardino (vicenza, italie nord-orientale): analyse micromorphologique des surfaces osseuses. proceedings xiii international congress of prehistoric and protohistoric sciences, 203-208. mallye j.b., thiébaut c., mourre v., costamagno s., claud é., weisbecker p. (2012) the mousterian bone retouchers of noisetier cave: experimentation and identification of marks. journal of archaeological science, 39(4), 1131-1142. margaritora d., dozio a., chelidonio g., turrini m.c., peresani m. (2020) the lower and middle palaeolithic settlements in the baldo-lessini mountains. results from a gis investigation. alpine and mediterranean quaternary, 33(1), 115-132. mariezkurrena k. (1983) contribution al conocimiento del desarrollo de la denticion y el esqueleto postcraneal de cervus elaphus. munibe, 35, 149-202. marín j., saladié p., rodríguez-hidalgo a., carbonell e. (2017) ungulate carcass transport strategies at the middle palaeolithic site of abric romaní (capellades, spain). comptes rendus palevol, 16, 103-121. marín j., rodríguez-hidalgo a., vallverdú j., gómez de soler b., rivals f., rabuñal j.r., pineda a., chacón m.g., carbonell e., saladié p. (2019) neanderthal logistic mobility during mis3: zooarchaeological perspective of abric romaní level p (spain). quaternary science reviews, 225, 106033. marín-arroyo a.b. (2009a) exploitation of the montane zone of cantabrian spain during the late glacial: faunal evidence from el mirón cave. journal of anthropological research, 65, 69-102. marín-arroyo a.b. (2009b) the use of optimal foraging theory to estimate late glacial site catchment areas from a central place: the case of eastern cantabria, spain. journal of anthropological archaeology, 28, 27-36. marín-arroyo a.b., ocio d. (2017) disentangling faunal skeletal profiles. a new probabilistic framework. historical biology, 30(6), 720-729. metcalfe d., jones k.t. (1988) a reconsideration of animal body part utility indices. american antiquity, 53, 486-504. miracle p. (2005) late mousterian subsistence and cave use in dalmatia: the zooarchaeology of mujina pećina, croatia. international journal of osteoarcheology, 15, 84-105. monahan c.m. (1998) the hadza carcass transport debate revisited and its archaeological implications. journal of archaeological science, 25, 405424. monegato g., pini r., ravazzi c., reimer p., wick l. (2011) correlating alpine glaciation with adriatic sea-level changes through lake and alluvial stratigraphy. journal of quaternary science 26, 791804. morin e. (2007) fat composition and nunamiut decision-making: a new look at the marrow and bone grease indices. journal of archaeological science, 34, 69-82. morin e. (2010) taphonomic implications of the use of bone as fuel. in: the taphonomy of burned organic residues and combustion features in archaeological contexts (ed. by théry-parisot i., chabal l., costamagno s.). palethnologie, 2, 215223. morin e., ready e. (2013) foraging goals and transport decisions in western europe during the paleolithic and early holocene. in: zooarchaeology and modern human origins: human hunting behavior during the later pleistocene (ed. by clark j.l., speth j.d.). springer, dordrecht, 227-269. morin e., speth j.d., lee-thorp j. (2016) middle palaeolithic diets: a critical examination of the evidence. in: the oxford handbook of the archaeology of diet (ed. by lee-thorp j., katzemberg m.a.). oxford university press, oxford, 1-37. 233 late neanderthal subsistence from zooarchaeology at san bernardino cave morin e., meier j., el guennouni k., moigne a.m. (2019) new evidence of broader diet for archaic homo populations in the northwestern mediterranean. science advances, 5 (3), eaav9106. moroni a., boschian g., crezzini j., montanari-canini g., marciani g., capecchi g., arrighi s., aureli d., berto c., freguglia m., araujo a., scaramucci s., hublin j.j., lauer t., benazzi s., parenti f., bonato m., ricci s., talamo s., segre a.g., boschin f., spagnolo v. (2019) late neandertals in central italy. high-resolution chronicles from grotta dei santi (monte argentario tuscany). quaternary science reviews, 217, 130-151. mozota holgueras m. (2012) el utillaje óseo del final del musteriense en el sector central del norte de la península ibérica. ph.d. dissertation, university of cantabria. nabais m. (2018) neanderthal subsistence in portugal: what evidence? archaeology international, 21 (1), 95-100. nilssen p.j. (2000) an actualistic butchery study in south africa and its implications for reconstructing hominid strategies of carcass acquisition and butchery in the upper pleistocene and pliopleistocene. ph.d. dissertation, university of cape town. patou-mathis m. (2000) neanderthal subsistence behaviours in europe. international journal of osteoarchaeology, 10, 379-395. peresani m. (1995-1996) sistemi tecnici di produzione litica nel musteriano d'italia. studio tecnologico degli insiemi litici delle unità vi e ii della grotta di san bernardino (colli berici, veneto). rivista scienze preistoriche, 47, 79-167. peresani m. (1996) the levallois reduction strategy at the cave of san bernardino (northern italy). in: reduction processes (châines opératoires) in the european mousterian (ed. by bietti, a., grimaldi, s.). quaternaria nova vi, rome, 205-236. peresani m. (2001) an overview of the middle palaeolithic settlement system in north-eastern italy. in: settlement dynamics of the middle palaeolithic and middle stone age (ed. by conard n.j.). kerns verlag, tübingen, 485-506. peresani m. (2011) the end of the middle palaeolithic in the italian alps. an overview on neandertal land -use, subsistence and technology. in: neanderthal lifeways, subsistence and technology one hundred fifty years of neanderthal study (ed. by conard n.j., richter j.). vertebrate paleobiology and paleoanthropology series, springer, new york, 249-259. peresani m., chrzavzez j., danti a., de march m., duches r., gurioli f., muratori s., romandini m., tagliacozzo a., trombino l. (2011) fire-places, frequentations and the environmental setting of the final mousterian at grotta di fumane: a report from the 2006-2008 research. quartär, 58, 131151. peresani m., delpiano d., duches r., gennai j., marcazzan d., nannini n., romandini m., aleo a., cocilova a. (2017) il musteriano delle unità a10 e a11 a grotta di fumane (vr). risultati delle campagne di scavo 2014 e 2016. fastionline documents & research, 397. peresani m., bertola s., delpiano d., benazzi s., romandini m. (2019) the uluzzian in the north of italy: insights around the new evidence at riparo broion. archaeological and anthropological science, 11, 3503-3536. peretto c., arzarello m., coltorti m., bertolini m., cui q-y., de curtis o., lebreton v., lembo g., marquer l., pieruccini p., ravani s., rufo e., sala b., talamo s., thun hohenstein u. (2020) grotta reali, the first multilayered mousterian evidences in the upper volturno basin (rocchetta a volturno, molise, italy). archaeological and anthropological science, 12 (3), 67. picin a., peresani m., vaquero m. (2010) application of a new typological approach to classifying denticulate and notched tools: the study of two mousterian lithic assemblages. journal of archaeological science, 38, 711-722. picin a., peresani m., falguères c., gruppioni g., bahain j.j. (2013) san bernardino cave (italy) and the appearance of levallois technology in europe: results of a radiometric and technological reassessment. plos one, 8(10), e76182. pickering t.r., egeland c.p. (2006) experimental patterns of hammerstone percussion damage on bones: implications for inferences of carcass processing by humans. journal archaeological science, 33, 459-469. pickering t.r., domínguez-rodrigo m., heaton j.l., yravedra j., barba r., bunn h.t., musiba c., basquedano e., diez-martín f., mabulla a., brain c.k. (2013) taphonomy of ungulate ribs and the consumption of meat and bone by 1.2-million-yearold hominins at olduvai gorge, tanzania. journal of archaeological science, 40(2), 1295-1309. pini r., ravazzi c., donegana m. (2009) pollen stratigraphy, vegetation and climate history of the last 215 ka in the azzano decimo core (plain of friuli, north-eastern italy). quaternary science reviews, 28, 1268-1290. pini r., ravazzi c., reimer p.j. (2010) the vegetation and climate history of the last glacial cycle in a new pollen record from lake fimon (southern alpine foreland, n-italy). quaternary science reviews, 29, 3115-3137. porraz g., peresani m. (2006) occupations du territoire et exploitation des matières premières: présentation et discussion sur la mobilité des groupes humains au paléolithique moyen dans le nord-est de l’italie. in: notions de territoire et de mobilité. exemples de l’europe et des premières nations en amérique du nord avant le contact européen (ed. by bressy c., burke a., chalard p., lacombe s., martin h.). èraul, 116, 11-21. potts r., shipman p. (1981) cutmarks made by stone tools on bones from olduvai gorge, tanzania. nature, 291, 577-580. ready e. (2010) neandertal man the hunter: a history of neandertal subsistence. explorations in anthropology, 10(1), 58-80. ready e. (2013) neanderthal foraging during the late 234 terlato g. et al. mousterian in the pyrenees: new insights based on faunal remains from gatzarria cave. journal of archaeological science, 40, 1568-1578. rendu w. (2010) hunting behavior and neanderthal adaptability in the late pleistocene site of pech-de -l’aze´ i. journal of archaeological science, 37, 1798-1810. rogers a.r. (2000a) analysis of bone counts of maximum likelihood. journal of archaeological science, 27, 111-125. rogers a.r. (2000b) on the values of soft bones in faunal analysis. journal of archaeological science, 27, 635-639. romandini m., nannini n., tagliacozzo a., peresani m. (2014) the ungulate assemblage from layer a9 at grotta di fumane, italy: a zooarchaeological contribution to the reconstruction of neanderthal ecology. quaternary international, 337, 11-27. romandini m., fiore i., gala m., cestari m., tagliacozzo a., guida g., peresani m. (2016) neanderthal scraping and manual handling of vulture wing bones: evidence from fumane cave. quaternary international, 421, 154-172. romandini m., terlato g., nannini n., tagliacozzo a., benazzi s., peresani m. (2018a) humans and bears a neanderthal tale. reconstructing uncommon behaviors from zooarchaeological evidence in southern europe. journal of archaeological science, 90, 71-91. romandini m., thun hohenstein u., fiore i.,tagliacozzo a., perez a., lubrano v., terlato g., peresani m. (2018b) late neandertals and the exploitation of small mammals in northern italy: fortuity, necessity or hunting variability? quaternaire, 29(1), 61-67. romandini m., crezzini j., bortolini e., boscato p., boschin b., carrera l., nannini n., tagliacozzo a., terlato g., arrighi s., badino f., figus c., lugli f., marciani g., oxilia g., moroni a., negrino f., peresani m., benazzi s. (2020a) macromammal and bird assemblages across the late middle to upper palaeolithic transition in italy: an extended zooarchaeological review. quaternary international, 551, 188-223. romandini m., oxilia g., bortolini e., peyrégne s., delpiano d., nava a., panetta d., di domenico g., marini p., arrighi s., badino f., figus c., lugli f., marciani g., silvestrini s., menghi sartorio j.c., terlato g., hublin j.j., benazzi s. (2020b) a late neanderthal tooth from northeastern italy. journal of human evolution, 147, 102867. rosell j., cáceres i., blasco r., bennàsar m., pilar b., gerard c., montserrat e.n., fernández-laso m.c., gabucio j.m., huguet r., ibáñez n., martín p., rivals f., rodríguez-hidalgo a., saldié p. (2012) a zooarchaeological contribution to establish occupational patterns at level j of abric romaní (barcelona, spain). quaternary international, 247, 69-84. salazar-garcía d., power r.c., sanchis serra a., villaverde v., walker m.j., henry a.g. (2013) neanderthal diets in central and southeastern mediterranean iberia. quaternary international, 318, 3-18. sanz m., rivals f., garcía d., zilhão j. (2019) hunting strategy and seasonality in the last interglacial occupation of cueva antón (murcia, spain). archaeological and anthropological science, 11, 3577-3594. schoville b.j., otárola-castillo e. (2014) a model of hunter-gatherer skeletal element transport: the effect of prey body size, carrier, and distance. journal of human evolution, 73, 1-14. shipman p. (1981) life history a fossil. an introduction to taphonomy and paleoecology. harvard university press, harvard, 232 pp. shipman p., rose j. (1984) cutmark mimics on modern fossil bovid bones. current anthropology, 25, 116-177. simpson e.h. (1949) measurement of diversity. nature, 163, 688. spagnolo v., marciani g., aureli d., martini i., boscato p., boschin f., ronchitelli a. (2020) climbing the time to see neanderthal behaviour’s continuity and discontinuity. su 11 of the oscurusciuto rockshelter (ginosa southern italy). archaeological and anthropological science, 12, 54. stiner m.c. (1994) honor among thieves. a zooarchaeology study of neandertal ecology. princeton university press, princeton, new jersey, pp. 448. stiner m.c., kuhn s.l., weiner s., bar-yosef o. (1995) differential burning, recrystallization and fragmentation of archaeological bone. journal of archaeological science, 22, 223-237. terlato g., livraghi a., romandini m., peresani m. (2019) large bovids on the neanderthal menu: exploitation of bison priscus and bos primigenius in northern italy. journal of archaeological science: reports, 25, 129-143. thun-hohenstein u., peretto c. (2005) the exploitation of the faunal remains in the mousterian levels at riparo tagliente (verona, italy). in: les premiers peuplements en europe: données récents sur les modalités de peuplement et sur le cadre chronostratigraphique. géologique et paléogéographique des industries du paléolithique inferieur et moyen en europe (ed. by molines n., moncel m.h., monnier j.l.). bar international series 1364, archaeopress, oxford, 261-268. thun hohenstein u. (2006) strategie di sussistenza adottate dai neandertaliani nel sito di riparo tagliente (prealpi venete). in: sala, b., tecchiati, u. (eds), studi di archeozoologia in onore del prof. alfredo riedel. soprintendenza archeologica del trentino alto adige, bolzano, 31-38. thun hohenstein u., bertolini m., channarayapatna s., modolo m., peretto c. (2018) bone retouchers from two north italian middle palaeolithic sites: riparo tagliente and grotta della ghiacciaia, verona. in: the origins of bone tool technologies (ed. by hutson j.m, garcia-moreno a., noack e.s., turner e., villaluenga a., gaudzinski-windheuser s.). monrepos, neuwied, 235-250. tomé c., vigne j.d. (2003) roe deer (capreolus capreolus) age at death estimates: new methods and modern reference data for tooth eruption and wear, and for epiphyseal fusion. archaeofauna, 12, 235 late neanderthal subsistence from zooarchaeology at san bernardino cave 157-173. vettese d. (2014) le traitement des carcasses d’ongulés chez les néanderthaliens de l’abri du maras (ardèche, mis4)/individualisme ou poids des traditions? master thesis erasmus mundus: quaternaire et préhistoire. muséum national d’histoire naturelle, paris, p. 106. vettese d., daujeard c., blasco r., boreal a., caceres i., moncel m.h. (2017) neandertal long bone breakage process: standardized or random patterns? the example of abri du maras (southeastern france, mis 3). journal of archaeological science: reports, 13, 151-163. vettese d., blasco r., cáceres i., gaudzinskiwindheuser s., moncel m.h., thun hohenstein u., daujeard c. (2020) towards an understanding of hominin marrow extraction strategies: a proposal for a percussion mark terminology. archaeological and anthropological science, 12, 48. villa p., mahieu è. (1991) breakage patterns of human long bones. journal of human evolution, 21, 2748. yravedra j., cobo-sánchez l. (2015) neanderthal exploitation of ibex and chamois in southwestern europe. journal of human evolution, 78, 12-32. zilhão j., angelucci d.e., igreja m.a., arnold l. j., badal e., callapez p., cardoso j.l., d’errico f., daura j., demuro m., dechamps m., dupont c., gabriel s., hoffmann d.l., legoinha p., matias h., monge soares a.m., nabais m., portela p., queffelec a., rodrigues f., souto p. (2020) last interglacial iberian neandertals as fisher-hunter-gatherers. science, 367(6485), eaaz7943. ms. received: march 2, 2021 revised: april 30, 2021 accepted: may 5, 2021 avaiable online: june 29, 2021 236 base genesi e significato del riempimento della depressione carsica di piano locce sul gran sasso d’italia (abruzzo) donatello magaldi1a/1b, alessandro lorè 2, paolo lorenzoni 3, roberto sulpizio 4, giovanni zanchetta 5, giuseppina benedetti 6 & fabiola ferrante 6 1adisat, facoltà d’ingegneria dell’università di l’aquila 1bdssnp, facoltà di agraria, università di firenze, e-mail: donatello.magaldi@unifi.it 2libero professionista, collaboratore di ricerca al disat, l’aquila 3cra-apc, unità di ricerca per i sistemi agro-pastorali dell’appennino centrale, rieti 4cirisivu, facoltà di scienze matematiche, fisiche, naturali dell’università di bari 5dst, facoltà di scienze matematiche, fisiche, naturali dell’università di pisa 6diccm, facoltà d’ingegneria dell’università di l’aquila riassunto: magaldi d. et al., genesi e significato del riempimento della depressione carsica di piano locce sul gran sasso d‘italia (abruzzo). (it issn 0394-3356, 2009). in una depressione carsica della catena del gran sasso (piano locce), nei pressi di s. stefano di sessanio in provincia di l’aquila, è stato effettuato un sondaggio profondo fino a 90 m circa, che ha permesso di campionare una alternanza di materiali finemente stratificati propri d’ambiente palustre e pedogenetico, costituiti questi ultimi quasi esclusivamente da piroclastiti a granulometria variabile tra media e moderatamente fine che riempiono questa ed altre valli carsiche dei dintorni. sui campioni sono state eseguite analisi chimico-fisiche di routine, micromorfologiche al microscopio da petrografia, microchimiche tramite spettrometria sem-eds e infine analisi chimiche totali per spettrometria ad emissione di raggi x. sulla base dei risultati analitici,si è suddiviso il riempimento in tre gruppi (α, β‚ γ). il gruppo αα rappresenta materiali sedimentari non pedogenizzati di ambiente palustre; il gruppo ββ materiali variamente pedogenizzati identificabili forse con gli udifluvents della soil taxonomy (soil survey staff, usda 1999), mentre il gruppo γγ‚ rappresenterebbe, sia sedimenti palustri, che tufiti pedogenizzate con suoli decisamente idromorfi, quali gli hydraquents suoli. in questi ultimi due gruppi, l’azione pedogenetica prendeva il sopravvento sulla sedimentazione, dando origine a microstrutture otticamente anisotrope e ad una certa orientazione dei domini argillosi. le analisi al microscopio elettronico condotte sui campioni più ricchi di minerali vulcanici, hanno evidenziato come il vetro vulcanico della stragrande maggioranza dei livelli sia completamente alterato e quindi inutilizzabile per la classificazione chimico-petrografica dei livelli stessi. due soli campioni provenienti dalla base (78-80 m) e dal tetto (5 m) della carota si presentavano meno alterati degli altri e sono stati classificati come una latite-trachite e una foidite, rispettivamente. il campione con composizione latitico-trachitica potrebbe essere tentativamente attribuita alle eruzioni pleistoceniche del vulcano di vico, caratterizzate da attività esplosiva di composizione trachitico-fonolitica (peccerillo, 2005), datate intorno a 170.000 anni fa. il campione di composizione foiditica, anche basandosi sull'associazione delle fasi mineralogiche dominate da leucite e clinopirosseno (assente il plagioclasio), può essere correlata con l'attività del vulcano dei colli albani, e più precisamente con l'eruzione dei peperini, le cui ultime fasi sono datate a circa 36.000 anni (freda et al., 2005). gli altri campioni analizzati sono risultati troppo alterati per essere utilizzabili, ma i dati sulle associazioni mineralogiche e di microanalisi delle fasi minerali indicano per la maggioranza di essi una stretta affinità con la composizione delle eruzioni dei vulcani campani (peccerillo, 2005). due soli campioni, sulla base della microanalisi dei pirosseni e dei plagioclasi e della paragenesi mineralogica, possono essere invece correlati con l’attività dei vulcani laziali (peccerillo, 2005). successivamente è stato preso in considerazione il rapporto limo/argilla in funzione della profondità, peraltro con andamento approssimativamente inverso a quello della percentuale di sostanza organica, come un possibile indice paleo-climatico, dove i valori più bassi indicherebbero periodi più favorevoli alla pedogenesi e alla diffusione della vegetazione (e quindi più caldi e più umidi), al contrario dei valori più alti che potrebbero testimoniare periodi più freddi e probabilmente più aridi. tutti i risultati testimoniano chiaramente che la valle carsica di piano locce (una vera e propria polje) è stata interessata in vari momenti del quaternario antico da una sequenza di eventi sedimentari (palustri-lacustri ) e pedogenetici, che si sono impostati su materiali piroclastici provenienti dalle eruzioni della provincia comagmatica romana e continuate fino ai giorni nostri a partire da tempi più antichi di 200 mila anni circa. le caratteristiche pedogenetiche osservate in sezione sottile insieme all’andamento del rapporto limo/argilla suggeriscono variazioni climatiche a diverso regime di umidità in ambiente di alta montagna. quando le condizioni climatico-vegetazionali consentirono l’instaurarsi di processi pedogenetici, si formarono suoli poco evoluti, fortemente condizionati da idromorfia. apporti colluviali e/o eolici da suoli maggiormente evoluti e di ambiente climatico molto differente (“terre rosse” tipo xeralfs o ustalfs) presenti sui rilievi carbonatici circostanti hanno contribuito, sia pure in minima parte, al riempimento della depressione. abstract: magaldi d. et al., the filling of karstic depression of piano locce (gran sasso range, abruzzi, italy) genesis and significance. (it issn 0394-3356, 2009). a deep test hole down to 90 m was carried out on the clastic filling of a karstic valley (polje) of the gran sasso (piano locce) range near s.stefano di sessanio (l’aquila province, italy ). this allowed us to sample alternated lacustrine and pedogenetic materials almost exclusively formed on medium-fine textured pyroclastic deposits. on almost one hundred samples some routine chemical-physical, optical micro morphologic, sem –eds microchemical determination and spectrometric by x ray emission analysis were performed. after the results elaboration, the collected samples were grouped (α, β‚ γ) as follows: α group was related to not pedogenetic sedimentary material (lake and or marsh); β group was identified as soil or soil derived material perhaps to be classified as udifluvent according to usda soil taxonomy; γ group was considered a mixture of the previous groups, except soils, which were classified as hydraquents. the pedogenetic process was prevailing on the ripening, so originating anisotropic microstructures with some orientation of clay domains in thin sections of undisturbed samples. the sem analysis indicated that most of volcanic glass was completely weathered: only the less weathered sample of the core bottom (78-80 m) was classified as related to latite-trachyte rock. il quaternario italian journal of quaternary sciences 22(2), 2009 171-188 172 d. magaldi et al. 1. introduzione alcuni anni fa (magaldi et al., 2006), furono eseguiti nei depositi di riempimento di due depressioni carsiche della catena del gran sasso d’italia due sondaggi profondi, in località piano locce e piano lucchiano, in comune di s. stefano di sessanio (l’aquila), rispettivamente 80 e 50 metri (fig.1). il piano locce ed il piano lucchiano sono depressioni tettono-carsiche che si aprono sul versante meridionale del massiccio del gran sasso d’italia. la loro origine è da ricondursi a fasi tettoniche, in regime distensivo e transtensivo, succedutesi a partire dal pleistocene inferiore, che hanno resecato una superficie a bassa energia di rilievo probabilmente pliocenica (superficie di anzano) secondo bertini et al., (1989), conferendo all’area una situazione strutturale del tipo horst e graben. il substrato è formato in prevalenza da unità carbonatiche mesozoiche, in facies di margine di piattaforma carbonatica e di transizione piattaforma-bacino (gradino ribassato, rampa carbonatica, scarpata), costituite essenzialmente da calcari bioclastici, calcareniti e calciruditi, in strati da medi a spessi, a luoghi con intercalazioni micritiche (apat, 2006). a queste seguono, in discordanza angolare, calcareniti e calciruditi cenozoiche in facies di rampa – piattaforma aperta. i depositi di riempimento delle depressioni sono costituiti da sedimenti di ambiente limno-palustre, con limitati apporti fluvio-torrentizi dai vicini e ripidi versanti; diffuse sono le coltri detritiche, a granulometria variabile, da grossolana (falde di detrito) a fine (coltri colluviali). i risultati di una prima serie di indagini condotta sulle due sequenze è stata descritta in una nota preliminare divulgativa alla quale si rimanda (magaldi et al., 2006). in questa sede basterà ricordare che le osservazioni di campagna e alcune analisi fisiche (granulometria e colore) e chimiche (% di sostanza organica sul setacciato a 2 mm e % di “ferro libero”), su una decina di campioni interpretati in campagna come tufiti pedogenizzate, sedimenti lacustri e/o sedimenti di suolo (tab.1 e tab.2), indicano che i due riempimenti sono costituiti da clasti di grandezza medio-fine, con caratteristiche a volte tipicamente lacustri, a volte tufitiche, queste ultime spesso intensamente pedogenizzate, e che esiste una relazione abbastanza evidente tra l’andamento del rapporto limo/argilla e il contenuto in sostanza organica (indicativo di processi pedogenetici avvenuti o in atto). il rapporto fe ossalato / fe ditionito (che scaturisce dall’analisi del “ferro libero”) è alto per quasi tutti i campioni, ad indicare che i processi pedogenetici sono stati poco evoluti. la nota ricordata suggeriva che alla genesi dei due riempimenti, avvenuta prevalentemente in ambiente riducente palustre, vista la frequenza di vivianite autisuch a composition could be related with the vico pleistocene eruption, which is constituted by trachite-phonolitic lavas ((peccerillo, 2005). consequently, this sample could be correlated to the pyroclastic deposit of the adriatic sea collected from a core 170,000 years before the present date (calanchi et al., 2008). taking into consideration the low contents of na2o and clo , a correction (3 – 4 %) was made for the sum of alkaline oxides in order to classify the glass as a tephritic-phonolite and phonolite lavas which are assumed to be erupted by the campania volcanism (peccerillo, 2005). based on the composition of both pyroxene and plagioclase minerals and the paragenesis, 2 samples were attributed to the latium volcanism. it was also considered that the silt/clay ratio vs. the core depth, which demonstrated an inverse trend with the percentage of organic matter, could be assumed as a paleo-climatic index. low values of the index could indicate more favourable conditions for pedogenesis unlike higher values which could indicate colder and perhaps more arid periods. in conclusion, all results likely indicate that the piano locce depression during quaternary age was subjected to various sedimentary and pedogenetic phases which occurred on pyroclastic deposits coming from the co-magmatic roman province, starting from the present age to more than 200,000 years ago. climatic variations in a high mountain environment are suggested by trends of both organic matter and silt/ clay ratio as well as micromorphological features, which in very few cases show periglacial aspects. some scarcely developed hydromorphic soils only formed when the favourable climatic conditions occurred. a very limited colluvial and/ or eolian material from more developed soils of different climatic environments (red soils such as xeralfs or ustalfs) together with some occasional deposition of creeks from surrounding carbonate slopes contributed filling the piano locce and nearby karst valleys. parole chiave: paesaggio carsico, provincia comagmatica romana, micromorfologia del suolo. keywords: karst landscape; co-magmatic roman province; soil micromorphology. fig. 1 localizzazione della zona dove è stato effettuato il sondaggio. location of study area where borehole was carried out. 173genesi e significato del riempimento della depressione carsica ... gena (fosfato di ferro idrato) avessero partecipato, sia materiali provenienti dall’erosione dei versanti, sia piroclastiti dai vulcani esterni all’area abruzzese e forse interni, a causa della comune presenza di sanidino e augite, a volte visibili anche ad occhio nudo. per di più, dall’analisi degli andamenti della % di sostanza organica, risultava che i due riempimenti sono tra di loro confrontabili, pur essendo sfasati stratigraficamente di una decina di metri. pertanto la nuova ricerca è stata focalizzata sul riempimento più potente di piano locce, litologicamente simile a quello di piano lucchiano, distante poco più di quattro chilometri in linea d’aria, sempre in comune di s.stefano di sessanio. 2. inquadramento geologico-geomorfologico di piano locce il piano locce, situato a una quota compresa tra 1225 e 1240 m s.l.m., ha una forma grossolanamente pentagonale con diametro medio di circa 1,1 chilometri. il settore centro-meridionale appare sostanzialmente pianeggiante, mentre il settore nord-orientale è occupato da un’ampia conoide di deiezione afferente ad un primitivo reticolo di valli, almeno in parte di origine fluviale, attualmente inattivo (fig. 2). la depressione è endoreica; lo smaltimento delle acque superficiali è assicurato da un inghiottitoio ubicato lungo il margine occidentale, in corrispondenza di una faglia distensiva che ha come espressione una ben evidente scarpata morfologica. la depressione è attualmente occupata da un laghetto, probabile residuo di una forma a maggior sviluppo nel passato, modificata successivamente dagli interventi antropici degli ultimi secoli. l’attuale profondità sabbia limo argilla tessitura (m) (%) (%) (%) 0,0 29,6 49,6 20,8 f 2,8 21,7 57,7 20,6 fl 3,1 16,2 55,5 28,3 fla 4,5 59,4 34,1 6,5 fs 6,2 49,8 28,4 21,8 fsa 8,4 59,6 32,8 7,6 fs 9,0 27,0 68,3 4,7 fl 9,4 20,2 50,7 29,1 fla 9,7 32,1 50,5 17,4 fl 10,9 54,2 41,8 4,0 fs 11,7 21,7 57,3 21,0 fl 13,0 27,9 55,0 17,1 fl 13,8 56,8 28,0 15,1 fs 14,0 26,4 33,6 40,0 fa 14,6 16,7 60,4 22,9 fl 16,0 23,3 53,6 23,1 fl 16,7 16,1 62,3 21,6 fl 18,4 8,1 85,2 6,7 l 21,4 41,3 45,3 13,4 f 22,0 45,1 37,8 17,1 f 23,0 26,5 50,1 23,5 fl 23,5 21,7 69,1 9,1 fl 24,0 11,8 68,7 19,5 fl 25,5 5,3 55,2 39,4 fla 26,4 7,9 59,6 32,4 fla 27,0 53,8 35,7 10,5 fs 27,4 14,5 58,7 26,8 fla 28,6 8,9 41,1 50,1 al 30,0 46,0 47,3 6,7 fs 30,6 23,5 69,3 7,1 fl 21,2 31,3 36,4 32,3 fa 31,8 59,8 29,4 10,8 fs 32,2 33,5 59,2 7,3 fl 33,0 34,5 57,9 7,6 fl 33,9 25,2 70,1 4,7 fl 35,1 57,8 31,5 10,7 fs 36,0 12,8 80,9 6,3 l 36,4 32,9 59,3 7,8 fl 37,3 29,4 62,9 7,7 fl 38,7 40,2 53,5 6,2 fl 40,0 18,1 59,9 22,0 fl 40,4 4,8 68,5 26,7 fla 42,1 4,3 87,0 8,7 l 42,7 42,4 53,3 4,3 fl 43,3 50,8 47,3 1,9 fs 44,0 61,0 37,4 1,6 fs 44,5 69,0 29,6 1,5 fs 46,0 23,1 69,3 7,6 fl 46,5 54,0 43,8 2,2 fs 49,6 64,8 33,0 2,2 fs 52,2 63,4 32,7 3,9 fs 54,0 42,7 52,0 5,3 fl 56,8 16,5 76,7 6,8 fl 57,4 49,9 44,7 5,4 fs 58,0 25,1 56,4 18,5 fl 58,7 16,7 75,7 7,6 fl 60,3 12,5 52,4 35,1 fla 61,0 23,6 47,1 29,3 fa 65,1 13,8 58,9 27,3 fl 65,2 17,4 67,1 15,5 fl 67,5 13,9 77,2 8,9 fl 71,0 23,7 70,4 5,8 fl 72,0 35,7 53,5 10,8 fl 73,0 31,7 57,0 11,3 fl 74,4 57,8 36,8 5,4 fs 75,3 36,8 55,6 7,6 fl 76,1 26,5 64,7 8,8 fl 78,0 14,2 75,8 10,0 fl 90,0 37,8 57,8 4,4 fl tab. 1 analisi tessiturali dei livelli campionati entro il riempimento della conca di piano locce. textural analysis of samples. tab. 2 rapporto fe ossalato/ fe ditionito e contenuto in fe libero in alcuni campioni con caratteristiche pedologiche visibili ad occhio. fe oss/ fe dit ratio and free (extractable) iron content for some samples of piano locce and piano lucchiano, that by field observation, were assumed to be soils or soil sediments. piano locce campione profondità fedi feos feos/fedi fe libero (m) (%) (%) (%) pl10 12,0 0,11 2,91 26,5 3,02 pl11 13,0 0,11 2,30 20,9 2,41 pl13 14,0 0,18 2,88 16,0 3,06 pl14 14,6 0,17 0,62 3,6 0,79 pl15 16,0 0,11 1,61 14,6 1,72 pl19 21,4 0,17 0,98 5,8 1,15 pl47 30,0 0,17 0,63 3,7 0,80 pl48 31,0 0,16 0,78 4,9 0,94 pl78 60,3 0,19 0,65 3,4 0,84 piano lucchiano campione profondità fedi feos feos/fed fe libero (m) (%) (%) (%) lu05 46,6 0,20 1,56 7,8 1,76 lu14 36,3 0,01 2,94 294,0 2,95 lu25 16,7 0,02 0,86 43,0 0,88 lu30 11,5 0,02 1,63 81,5 1,65 lu31 10,5 0,04 2,54 63,5 2,58 lu32 9,3 0,03 1,66 55,3 1,69 lu34 5,1 0,04 2,83 70,8 2,87 lu35 4,5 0,04 2,25 56,3 2,29 174 copertura pedologica consiste in un suolo franco sabbioso argilloso, di colore umido bruno molto scuro (10 yr2/2) che sostiene una vegetazione prativa spontanea, a luoghi coperto da ciottoli calcarei di diametro compreso tra 2 e 10 cm, passante dopo circa 2-3 m di profondità ad un livello ghiaioso di origine alluvionale, con matrice di colore umido bruno giallastro scuro (10 yr3/4). questo suolo a profilo a/c si è formato prevalentemente su materiali colluviali provenienti dai versanti circostanti, contiene pochi minerali vulcanici (sanidino, clino-pirosseno verde leggermente pleocroico e apatite) non arrotondati, ed è classificabile come hydraquent, a causa delle sue condizioni aquic (risultanti principalmente dal colore umido) per la maggior parte degli anni (usda soil survey staff, 1999). 3. caratteristiche generali del riempimento di piano locce e metodi d’indagine come è già stato detto, il riempimento è costituito da una alternanza di materiali finemente stratificati propri d’ambiente lacustre e di piroclastiti a granulometria (sul setacciato a 2 mm) variabile tra media e fine. alcuni livelli più superficiali sono formati da clasti calcarei grossolani poco smussati e appiattiti, mentre altri sono stati classificati in campagna come suoli e sedimenti di suolo con caratteri di idromorfia. sulla base del colore munsell opportunamente codificato (vedi didascalia fig. 3) sono stati distinti in via preliminare due gruppi di sedimenti, il primo tra 0 e 30 m, il secondo da 30 fino alla massima profondità raggiunta (80 m). ad eccezione dei livelli situati rispettivamente a 4,5 e 9 m di profondità, la parte superiore è rappresentata da materiali misti d’ambiente generalmente ossidante (colori umidi principalmente con hue compreso tra 10yr e 2.5y, codificati con i numeri 10 e 20) mentre quella inferiore da matefig. 2 schema geologico-morfologico del piano locce in provincia di l’aquila. 1 unità calcaree mesozoiche, 2 brecce calcaree in matrice rossastra (formazione di fonte vedice auct., sintema di aielli-pescina), 3 detriti di falda, coltri colluviali (sintema di valle majelama), 4 sedimenti fluvio-lacustri, 5 scarpata di faglia, 6 . orlo di polje, 7 conoide di deiezione inattiva, 8 – inghiottitoio, 9 stagno (parzialmente modificato per azione antropica), 10 ubicazione sondaggio. geological and geomorphologic draft of the piano locce area (l’aquila province). 1 mesozoic calcareous units, 2 calcareous breccia with red matrix (formazione di fonte vedice auct., sintema di aielli-pescina), 3 scree slope and colluvial deposit (sintema di valle maielama), 4 river –palustrine sediments, 5 fault scarp, 6 polje edge, 7 inactive alluvial fan, 8 swallow hole, 9 marsh partly modified by human action, 10 borehole location. d. magaldi et al. 175 riali depositati in ambienti quasi esclusivamente riducenti (colori con hue compreso tra 2.5 y e 5y, codificati con i numeri 20 e 40). nel primo gruppo il rapporto limo/argilla tende ad essere mediamente più basso che nel secondo, mentre il contrario accade per la sostanza organica che tende a diminuire con la profondità. per il resto, i due gruppi sono pressoché simili. e’ stato quindi necessario sottoporre i campioni ad una serie di analisi più specialistiche e dettagliate, quali l’analisi micromorfologica in sezione sottile (bullock et al., 1985; stoops, 2003) e quella chimica totale tramite xrf presso la facoltà di ingegneria della università di l’aquila. la prima consiste nell’osservazione al microscopio ottico a luce polarizzata di sezioni sottili petrografiche, ottenute da campioni indisturbati di sedimento opportunamente indurito con resine sintetiche, mentre la seconda utilizza “pasticche” di sedimento compresso e quindi analizzato con uno spettrometro ad emissione di raggi x, mod. spectroxepos. sui livelli più ricchi in vetro e minerali vulcanici sono state eseguite microanalisi tramite spettrometria sem-eds presso il dipartimento di scienze della terra dell’università di pisa. 4. risultati delle analisi micromorfologiche e chimiche 4.1. analisi micromorfologiche lo studio al microscopio polarizzatore è stato eseguito sulla base di considerazioni derivanti dalla petrografia sedimentaria applicata (bertrand, 1969; selby, 1993; tickel, 1965) e di micromorfologia del suolo e del regolite (brewer, 1964; bullock et al., 1985; stoops, 2003). sono state perciò descritte, per ciascun campione e nell’ordine, le seguenti caratteristiche: • tipologia della microstruttura (stoops, 2003); • relazioni tra matrice (pasta di fondo, cemento) e costituenti grossolani > di 20 microns; • natura dei costituenti minerali e organici (coarse mineral grains and rock fragments; organic components; elements figurés), distinti in clastici e di neoformazione in situ; • figure (features) di origine pedogenetica, sia formate in situ che trasportate dall’esterno; • tipologia della matrice (fine groundmass type and bfabric). tutti i campioni sono risultati “fango sostenuti” (matrix supported) o porfiroschelic secondo la dizione micromorfologica e pertanto questo carattere non è stato preso in considerazione al fine della loro differenziazione. al contrario si sono notate evidenze di alcune microstrutture presumibilmente di origine pedogenetica, in diversi campioni, la maggior parte dei quali, tuttavia, è caratterizzata da una microstruttura massiva (matrix microstructure, secondo grabowskaolszewaska et al., 1984, in selby, 1993) o più di rado, finemente laminata, di origine prettamente sedimentaria. la pasta di fondo è quasi esclusivamente costituita da vetro vulcanico variamente alterato, spesso con formazione di idrossidi di ferro e minerali argillosi sia amorfi che cristallini. il campione che ne contiene di più (oltre il 90%) è pl 82 a 67-68 m di profondità, dove il vetro appare quasi completamente isotropo. si possono distinguere al microscopio due tipi di vetro: uno marrone-giallastro con bolle e indice di rifrazione superiore alla resina del vetrino (1,54) e un altro grigio e grigio scuro con indice inferiore alla resina e, a volte, con inclusi microliti di feldspato. i costituenti grossolani (coarse) sono stati distinti in due gruppi: gli inorganici (rocce e minerali ) e gli organici. quest’ultimi, abbastanza rari, sono riconoscibili come frammenti carbonizzati, frustoli legnosi e residui vegetali non identificati. tra i litorelitti prevalgono i frammenti di vulcaniti, sia basiche che acide e, molto subordinatamente, le selci e le arenarie quarzitiche. i costituenti minerali grossolani sono stati a loro volta distinti sulla base della presunta provenienza: vi sono infatti minerali quali muscovite, epidoto, clinozoisite, clorite, calcite, quarzo, tormalina, cloritoide, zircone, granato (incolore), anatasio e glauconite, che derivano probabilmente dal residuo insolubile dei litotipi calcarei e dolomitici della zona e/o da suoli e sedimenti vari formatisi a carico delle formazioni flyschioidi situate nel versante adriatico (ad esempio, arenaria della laga). questi costituenti sono in quantità nettamente trascurabile rispetto al gruppo di minerali di chiara provenienza vulcanoclastica: sanidino, biotite, clinopirosseni, plagioclasi, anortoclasio, e più raramente, magnetite, granato (gialloscuro), orneblenda bruna, palagonite, titanite, leucite ed haüyna,quasi tutti abbastanza freschi ma, a volte, con orlo di riassorbimento magmatico. vi sono due tipi principali di clinopirosseno: il primo è incolore, biassico positivo, con c: γ = 35°-40°, il secondo, sempre biassico positivo, è leggermente verde e pleocroico con c: γ = 40°-45°. in prima approssimazione si ritiene che il primo possa essere un termine diopsidico, mentre il secondo un termine augitico, forse titanifero. l’anortoclasio è stato riconosciuto solo in alcuni campioni sulla base della caratteristica geminazione a tratteggio incrociato (cross–hatch) e dal 2v nettamente superiore a quello del sanifig. 3 relazioni tra il colore munsell e il rapporto limo/argilla dei vari campioni. il colore è codificato secondo lo schema seguente: 7.5yr=7,5; 10yr=10; 2.5y=20; 5y=40. munsell soil color vs. silt/ clay ratio for all samples. the colour code is the following: 7.5yr=7,5; 10yr=10; 2.5y=20; 5y=40. genesi e significato del riempimento della depressione carsica ... 176 dino, minerale presente e frequente in tutti i campioni. rari i feldspatoidi (leucite) e sempre molto alterati. minerali di neoformazione (pedogenetica e/o diagenetica) nel sedimento sono la vivianite (fosfato di fe idrato ), la siderite (carbonato di fe) e la calcite spatica. molto rara, e riconosciuta solo in due campioni, la gibbsite (idrossido di al). la vivianite, tipica di sedimenti e suoli di ambienti riducenti, si presenta sotto forma di aggregati nodulari e raggiati anche millimetrici e centimetrici, con il tipico colore bianco che diviene poi celeste chiaro per ossidazione, ben visibile anche ad occhio nudo. secondo retallack (2001) potrebbe formarsi anche per sostituzione del carapace degli artropodi. west (1968) elenca la vivianite fra i minerali riscontrati nei depositi pleistocenici. altri (www.mindat.org) affermano che la vivianite sostituisce materiali organici, torba, ferro delle paludi ecc. o quanto meno è strettamente associata con questi materiali nei depositi alluvionali recenti. la siderite si presenta in varie forme. compaiono, infatti, i festoni e le forme nodulari a raggiera (sferosiderite) che sono generalmente associate alla vivianite, indicando così ambienti di formazione moderatamente riducenti. la gibbsite è stata riscontrata come alone intorno a un granulo di clorite e la sua presenza potrebbe essere legata alla trasformazione di materiali allofanici derivati dalla alterazione del vetro vulcanico (buol et al., 1980; bullock et al.,1985). numerose come tipologia sono le figure (features) di origine pedogenetica, per la maggior parte provenienti per erosione dai suoli circostanti l’ambiente di sedimentazione del deposito, e solo in parte più limitata, derivanti da processi pedogenetici agenti sul deposito in condizioni di idromorfia, presumibilmente tipo “surface water gley” (driessen & dudal, 1991). qui di seguito sono descritte le varie figure. noduli. sono costituiti per la maggior parte da singoli individui rotondeggianti e da aggregati a forma irregolare, di idrossidi di ferro/manganese, sia formatisi in situ (orthic nodules) sia trasportati dall’esterno (anorthic nodules). abbondanti sono anche gli aggregati di materiale pedogenizzato (matrix anorthic nodules) che testimoniano la provenienza da suoli presenti probabilmente sui fianchi del bacino. secondo la classificazione micromorfologica più recente sarebbero comprese tra i noduli anche le papule (brewer, 1964), più modernamente classificate come clay nodules. sono frammenti di argilla finemente cristallina iso-orientata che testimoniano la presenza di suoli ad orizzonte illuviale, probabilmente le “terre rosse” da calcare, osservabili ancora nella conca aquilana (magaldi & tallini, 2000). nella descrizione delle sezioni si è tuttavia preferito separarle dagli altri noduli in considerazione del loro importante significato genetico. infilling. traducibili in italiano come “riempimenti”, sono cavità riempite da materiale pedogenetico vario, per cause prevalentemente biologiche. in questo deposito sono stati classificati come tali alcuni corpi a contorno netto , costituiti da accumulo regolare di argille iso-orientate entro cavità rotondeggianti. clay coatings. in tre campioni (pl20, pl21, pl46) sono stati riconosciuti rivestimenti di argilla di colore (a nicols //) giallo-bruno, a volte a tessitura limoso-fine, che si sono sicuramente formati in situ, in seguito a processi pedogenetici di mobilizzazione e trasloco di argilla di neogenesi o ereditata, tipici degli alfisols e degli ultisols (soil taxonomy, usda, 1999). fabric of micromass. in accordo con stoops (2003), la fabric della micro-massa del suolo o b-fabric (parte fine della groundmass che costituisce il materiale di base del suolo ad esclusione delle figure pedologiche) riflette i processi pedogenetici attuali e del passato che hanno agito sul suolo e, per di più, le caratteristiche litologiche e di alterazione del parent material. la maggior parte si presenta con una undifferentiated fabric (indifferenziata) e unistrial (laminare), tipologie che testimoniano condizioni tipicamente sedimentarie piuttosto che pedogenetiche. al contrario i depositi che sono stati soggetti a condizioni ossidanti, anche temporanee e periodiche, si presentano spesso con domini argillosi orientati e anisotropi, in genere disposti lungo le pareti delle fessure e intorno ai granuli, a causa della contrazione e del rigonfiamento dei materiali argillosi (stress cutans, secondo brewer, 1964) che originano una striated fabric. sono state riconosciute le seguenti cinque b-fabric: undifferentiated – potrebbe corrispondere in sedimentologia alla struttura massiva e isotropa. crystallitic – caratterizzata dalla precipitazione tra i granuli più grossolani di un cemento, in questo caso calcitico, dovuto probabilmente a momenti di maggiore aridità del clima. speckled domini argillosi anisotropi piccoli e orientati casualmente: in questo caso rappresenta un inizio di argillificazione del deposito. striated – domini argillosi anisotropi in strisce o zone allungate, costituiti da argille orientate: in questo caso si tratta di un orientamento dovuto a contrazione e rigonfiamento periodico delle argille. strial – e’ costituita da una (unistrial) o due (bistrial) orientazioni delle argille secondo micro-lamine tra loro parallele, generalmente di origine sedimentaria. i risultati delle indagini sulle sezioni sottili sono espressi nella tab. 3 insieme ai valori della sostanza organica e del rapporto limo/argilla. le caratteristiche micromorfologiche sono codificate secondo quanto si evince dalla legenda della tab. 4, mentre le numerose foto ottenute con macchina fotografica canon power shot s50 digitale montata su microscopio polarizzatore nikon optiphot2-pol con oculare 10 x e obiettivi di 4, 10 e 20 x, sono presentate a colori, secondo un raggruppamento ragionato, nell’allegato cd e organizzate come segue: • composizione mineralogica e litologica originaria delle piroclastiti: frammenti di rocce sedimentarie e vulcaniche, minerali vulcanici e sedimentari: dalla foto 8 alla foto 16 • figure pedogenetiche formatesi in situ o di apporto esterno: dalla foto 17 alla foto 34 • minerali di neoformazione (pedogenetici e/o diagenetici): : dalla foto 35 alla foto 49 • residui vegetali: dalla foto 50 alla foto 55 • microstrutture sedimentarie, periglaciali e resti fossilizzati: dalla foto 56 alla foto 61. dall’esame comparato delle caratteristiche riscontrate nei vari livelli attraversati dal sondaggio emergono alcuni fatti, oltre la già ricordata relazione inversa tra contenuto in sostanza organica e il rapporto limo/argild. magaldi et al. 177 tab. 3 risultati dell’analisi micromorfologica in sezione sottile di 59 campioni rappresentativi del riempimento. qualitative micromorphological analysis of thin sections of 59 undisturbed samples. deepness color silt/ % clastic min. volcan.min. neoform. pedofeatures micromass environment in m codex clay organic & & rocks minerals (ambiente di matter sed. rocks formazione) pl 00 0 10 2,4 32 q,e, h,d,b no,pa, un,uns gruppo gamma pl 01 2,80 7,5 2,8 12 c,s,q b,h nfe,nca,nar msp gruppo gamma pl 02 3,10 20 2,0 13 s h,d, no,pa, nca mos gruppo beta pl 03 4,50 40 5,3 6 c,s,l n,h,p,b,f ca nca,nfe,inf uns,cry gruppo alfa pl 04 6,20 10 1,3 8 s,r, v, h,p, vi pa, pas gruppo gamma pl 05 8,40 10 4,3 4 c,l v,d,h,b,p vi,si,le,gi pa,nar,no msp gruppo gamma pl 06 9,00 40 14,5 11 l v,b,d,h,p, nar un gruppo alfa pl 07 9,40 7,5 1,7 13 c,l,q d,h,y,b,f, vi,si nfe,pa, msp gruppo gamma pl 08 9,70 20 2,9 10 s,q,e, c,b v,d,h,p,n no, nca mos gruppo beta pl 09 10,90 20 10,5 4 c, v,h,d,n, nar,pa,no un gruppo beta pl11 13,00 10 3,2 5 v,p,d,n,h no,inf, mos gruppo gamma pl13 14,00 10 0,8 10 s, v,f,h,n,b vi nfe,pa,inf mos,gr gruppo gamma pl14 14,60 10 2,6 12 s,c,q,r h,v,d, no uns,gs gruppo gamma pl15 16,00 10 2,3 24 s,m g,b,h,d,t si,vi, gi no uns,gs gruppo gamma pl16 16,70 10 2,9 16 c,l d,h,b, vi,si nar,pa cro gruppo gamma pl17 18,40 20 12,7 7 s,m,e v,d,h,b, vi,si, no,pa,nfe,nar un gruppo beta pl18 18,40 10 12,7 17 s v,h,d,b vi, si, no,nar uns gruppo gamma pl19 21,40 10 7,7 21 c,r d,h,o,b vi ccu, nar,nfe mos,msp gruppo gamma pl20 22,00 20 2,2 26 m d,h,t, vi,si, nfe,nor, scu mos gruppo beta pl40 23,00 10 7,6 16 s,m,l v,d,b,h vi, pa, nca,nfe un gruppo gamma pl41 23,50 10 3,5 18 s g,d,b,j,f,y,a collofane ? nfe, un gruppo gamma pl42 24,00 20 1,4 17 s,m, d si un gruppo beta pl43 25, 30 20 3,0 14 v,s,q,w g,d,h,b,f,p si nar,nfe,pa un gruppo beta pl21 25,70 20 3,0 13 s,l g,h,d,k,b vi nar,ccu mos gruppo beta pl 46 29,0 20 4,0 12 s,r,o, d,p,o,b,t,h,a vi nar,ccu,no,inf,pa cro gruppo beta pl47 30,00 10 5,2 11 w g, p,h,b,w,f nfe un gruppo gamma pl 48 31,00 10 9,7 10 s d,h,b,g nar,no,nfe ss gruppo gamma pl49 30,60 20 1,1 10 s v,d,h,f,p,b,o,g si nar,no ss gruppo beta pl51 31,80 20 8,1 7 s,r p,d,n,b,t no,nar,pa un gruppo beta pl52 32,20 40 7,6 8 s,e,m,z v,d,n,h,p,t, ca, nfe,pa,no,scu un gruppo alfa pl54 32,95 20 15 9 a,r d,b,h,g,v nfe,pa,nar un gruppo beta pl55 33,90 20 3 7 s d,b,h,p,f,g,v nfe,pa,nar un gruppo beta pl57 36,00 20 7,6 7 z,o v,h,p,n,d,f,b si nfe un gruppo beta pl58 36,40 20 8,1 9 v,d,b,p,h,f nfe,pa ss gruppo beta pl59 37,30 20 8,6 24 s d,b,h,f,g,v si,go nar,pa,nor?,nfe ss,un gruppo beta pl60 38,70 20 8,6 12 s d,h,b,g nfe, fe-mottles bs,gs,pas gruppo beta pl62 40,00 20 2,6 4 m b,p,d pa,nfe mos gruppo beta pl63 40,40 20 10,1 4 s,l,m, v,d, ca nfe cry,un gruppo beta pl64 42,10 40 12,3 6 o v,n,h,d,x,b,p nca,nfe,pa un gruppo alfa pl65 42,70 40 25,4 8 d,h,b ca? pa,nca cry,un gruppo alfa pl66 43,30 40 24 8 s,l,z j,p,n,h,w,b, ca nca, pa un-cry gruppo alfa pl67 44,00 40 20,3 8 d,h,v ca nca cry gruppo alfa pl68 44,50 20 9,1 7 c,s,q,m,l,e v,d,b,h,n ca pa,nar,nfe un gruppo beta pl71 49,60 20 8,4 15 s,r,q d,h,b pa,nfe,nar ss gruppo beta pl72 52,15 10 8,9 15 s v,g,d,h,b,s,f,t,w si nar,pa,nfe un gruppo gamma pl74 56,80 10 9,8 10 s,l,e,m v,k,h,d,f,b,p, si, nfe, un (fe) gruppo gamma pl76 58,00 10 10 10 c d,h,g un gruppo gamma pl77 58,70 20 1,5 12 e v,h,p,d un gruppo beta pl78 60,30 20 1,6 15 s,r,q,u d,b, vi pa,no,inf uns,gs gruppo beta pl79 61,00 20 2,1 14 m,e,l,r b,p,d,h,k, vi,si nar,inf,nfe,pa,scu uns-pas gruppo beta pl80 65,10 20 4,3 13 s,e,m,q, v,h,d,f si nfe, pa un gruppo beta pl81 65,20 40 8,7 8 s,e,m,q, v, h,d, nfe,nor, un gruppo alfa pl82 67,50 40 12,1 4 l v =90%,b,d,h nfe,nar un gruppo alfa pl84 71,00 20 5,0 7 q,s,r v,h,d,p vi inf,nfe,nor un gruppo beta pl85 72,00 20 5,0 7 q p,d,h, inf,nfe,nor un gruppo beta pl86 73,00 40 6,8 8 l,s x,h,d,b,n,f, nar,pa un gruppo alfa pl88 75,30 10 7,3 7 s,l v,g,s,h,x,b, nfe,pa,nar,inf, msp gruppo gamma pl89 76,10 40 7,6 5 a,q v,d,p,n,h,b,t,x,i nfe un-cry gruppo alfa pl90 78,00-80,00 40 13,2 4 v,d,p,n,h,b,x nfe un-cry gruppo alfa genesi e significato del riempimento della depressione carsica ... la. si nota (fig. 3) che questo rapporto tende a crescere con la crescita del valore convenzionale (v. didascalia della fig. 3) del codice munsell (da un hue “rossastro” ad un hue più grigio-azzurro) assumendo tuttavia valori più dispersi, con la progressiva scomparsa dei colori “ossidati” e la crescita di quelli “ridotti“, suggerendo così la maggior frequenza del l imo lacustre nei depositi di ambiente sedimentario, e una minor frequenza rispetto all’argilla in quelli presumibilmente pedogenizzati. insieme al rapporto limo/argilla e applicando l’analisi statistica multivariata (codice statistica) alle figure pedologiche e al colore secondo i codici convenzionali riferiti nella fig 3., si ottiene la distribuzione dei (59) campioni in 3 cluster (α, β‚ γ) espressa nella fig. 4, a livello di distanza euclidea da 7 a 12. questi gruppi sono distinti a l ivello più alto dal colore munsell e, immediatamente dopo, dal rapporto limo/argilla. analizzando in dettaglio i tre gruppi sulla base delle restanti caratteristiche e della composizione mineralogica, si ottengono le informazioni che seguono. gruppo αα. caratterizzato dal colore 5y (codice 40), dall’assenza di b-fabric tipicamente pedogenetiche, da valori di sostanza organica mediamente eguali al 7%, dalla neoformazione abbastanza diffusa di caco3 sotto forma di noduli, di cristalli intercalari e di matrice carbonatica (crystallitic groundmass), rappresenta probabilmente un ambiente palustre a granulometria sensibilmente limosa, in condizioni di ph neutro o subalcalino che in qualche caso andava anche soggetto a momenti di disseccamento e/o di aridità tali da favorire la precipitazione del carbonato. l’analisi pollinica (presenza di conifere quali, abies, picea, pinus mugus ecc.) di un campione prelevato a 67-68 m indica un clima più freddo di quello attuale. il gruppo tende a prevalere oltre i 30 m di profondità. gruppo ββ. questo gruppo eterogeneo, caratterizzato dal colore 2.5y (codice 20), è costituito sia da sedimenti sia da suoli, 178 tab.4 codici utilizzati per le descrizioni micromorfologiche riferite nella tab.3. meaning of codes used for micromorphological description. codificazione dei caratteri micromorfologici minerali clastici e rocce sedimentarie: minerali di neoformazione: clastic minerals neoformed minerals and sedimentary rocks a others ca carbonate c carbonate gi gibbsite e epidote le lepidocrocite i chloritoide si siderite l chlorite vi vivianite m muscovite o garnet figure pedologiche: micromorphologic features q quartz ccu clay-cutans r sandstone inf infilling s chert nar soil-relicts u tourmaline nca ca-nodules w clinozoisite nfe fe-nodules z zircon nor org-aggregates pa papules scu stress-cutans minerali e rocce vulcanici: volcanic minerals and rocks a others fabric microstrutturale: ground-mass fabric b biotite d sanidine rating f magnetite bs bistrial 1 g magm.rock cro cross-striated 5 h clino-pyroxene cry crystallitic 2 j feldspathoids gs grano-striated 4 k apatite mos mono-striated 4 n anortoclase msp mosaic speckled 3 o garnet pos parallel striated 5 p plagioclase pas poro-striated 4 t titanite ss stipple speckled 2 v glass un undifferentiated 0 x hornblende uns unistrial 1 y spinel fig. 4 raggruppamenti (cluster) ottenuti attraverso l’analisi discriminante (codice statistica) considerando come variabili le caratteristiche micromorfologiche. si evidenziano chiaramente a livello 7 -12 tre gruppi principali di campioni. clusters derived from discriminating analysis (statistica software) using some micromorphological features. there are at 7-12 level 3 main samples groups. d. magaldi et al. 179 fig. 5 stratigrafia semplificata del deposito di riempimento della conca. simplified stratigraphy of deposit. tutti formatisi in condizioni comunemente riducenti, testimoniate dalla frequenza della vivianite e della siderite, minerali che compaiono soli o associati. sono sempre ricchi di sostanza organica (in media 11%) e evidenziano apporti, oltre che da piroclastiti, anche da suoli relativamente più evoluti (“terre rosse“ ?) delle immediate vicinanze. nei campioni pl 21 (25,70 m ) e pl 46 (29 m ) si osservano invece resti di pellicole di argilla illuviata (clay coatings) che testimoniano la formazione in situ di suoli maggiormente evoluti (aqualfs oppure boralfs?) , associati a micro-strutture presumibilmente crioturbate (involutions) (vedi cd) che suggerirebbero un clima sensibilmente più freddo dell’attuale. l’interpretazione di queste figure è basata sulla stretta somiglianza che queste presentano con quelle macroscopiche osservabili nei suoli di ambiente periglaciale come i cryorthents e diverse da quelle ricordate per sismiti in depositi pliocenici lacustri da brustur & jipa (2007).anche l’analisi pollinica , sfortunatamente ancora in corso, ha evidenziato nella successione del riempimento momenti più freddi a 3 m e a 44-45 m di profondità. gruppo γγ. caratterizzato da colori più giallo-rossastri, sia della matrice, sia delle screziature (rispettivamente 10yr e 7.5yr, codice 10), da contenuti molto alti (media 13 %) in sostanza organica, ma non uniformemente distribuiti nella sequenza, da b-fabric anisotropiche comunemente attribuite alla pedogenesi, ma in condizioni prevalentemente riducenti, come dimostrato dalla presenza di vivianite e siderite. si tratta presumibilmente di suoli idromorfi torbosi poco evoluti (come rivelato dal rapporto fe-ossalato/fe-ditionito su alcuni campioni presi a caso, tab. 2). la colonna stratigrafica, ipotizzata sulla base delle precedenti considerazioni, è mostrata in fig. 5. le analisi petrografiche e micromorfologiche confermano gran parte delle osservazioni fatte in campagna all’atto del sondaggio e mettono in evidenza che il riempimento della valle carsica è costituito sia da sedimenti ricchi di materiali vulcanici in un ambiente prevalentemente palustre-lacustre riducente (abbondanza di sostanza organica e probabile neoformazione di vivianite e siderite) entro il quale si depositavano anche sedimenti di suoli relativamente più evoluti e forse materiali eolici dalla regione adriatica (arenarie della laga, e forse addirittura dal nord africa secondo quanto ipotizzato da yaalon, 1987), sia da veri e propri suoli tipicamente idromorfi, a diverso grado di evoluzione, di cui si conservano indiscutibili tracce. sulla base delle precedenti osservazioni è possibile ricostruire, sia pure approssimativamente, le condizioni ambientali dei 3 gruppi. il gruppo αα rappresenterebbe condizioni prevalentemente sedimentarie, il gruppo γγ suoli identificabili forse con gli udifluvents della classificazione usda sulla base della distribuzione e dell’abbondanza della sostanza organica, delle figure di idromorfia, di una certa laminazione e della scarsa evoluzione testimoniata dal colore e dalla tipologia della fabric. in alcuni casi potrebbero essere anche aquic udifluvents e vitrandic udifluvents,questi ultimi caratterizzati dall’abbondanza di materiali vetrosi), mentre il gruppoββ‚ rappresenterebbe sia sedimenti palustri che suoli decisamente idromorfi, quali gli hydraquents sulla base delle condizioni riducenti quasi permanenti, con alcune eccezioni già genesi e significato del riempimento della depressione carsica ... ricordate (alfisuoli idromorfi ?). in tutti questi suoli l’azione pedogenetica prendeva il sopravvento attraverso un progressivo ripening (maturazione del sedimento in condizioni idromorfe),dando origine a microstrutture otticamente anisotrope e ad una certa orientazione dei domini argillosi, in parte dovuta tuttavia al periodico disseccamento. 4.2. analisi chimiche e chimico-mineralogiche dei depositi la composizione chimica totale, tramite fluorescenza x ed espressa secondo gli ossidi più significativi di 24 campioni scelti a caso ma rappresentativi dell’intera serie (tab. 5), appare completamente diversa da quella di suoli e sedimenti fluviali (wakatsuki et al., 1977) ma risulta compatibile con quella di prodotti vulcanici medio-basici e in particolare con quelli appartenenti alla provincia comagmatica romana (d’amico et al., 1989) secondo la classificazione riferita da d’argenio et al., 1994, pag 53, basata sulla percentuale di cao e di allumina e le informazioni sulle caratteristiche chimico-mineralogiche (alto tenore in al2o3, presenza di bario) illustrate da conticelli et al. (2004) e da boari & conticelli (2007), anche se il contenuto in silice e metalli alcalini rivela una forte alterazione del materiale. ne segue che l’intero riempimento, costituito da materiali molto simili tra loro, deve interpretarsi come una sequenza di piroclastiti fortemente alterate e variamente mescolate con apporti dai rilievi circostanti e dal residuo insolubile dei calcari, che si sono sedimentate in ambienti prevalentemente riducenti di tipo lacustrepalustre ma soggetti a periodiche emersioni che ne determinavano una pedogenesi generalmente modesta. il contributo dei calcari è stato tuttavia scarso a causa del loro basso contenuto in residuo insolubile: infatti una analisi calcimetrica di una trentina di litotipi della catena del gran sasso ha fornito valori di caco3 mediamente superiori all’80 % . per di più, la larga diffusione di depositi piroclastici di varia provenienza nella regione abruzzese è stata da tempo segnalata e studiata (bosi & bertini, 1970; ferrari & malesani, 1973; bosi & locardi , 1991; colica et al., 1993; marcolini et al., 2003; narcisi, 1995; stoppa & rosatelli, 2003; tallini et al., 2002; d’orefice et al., 2006), sebbene vi siano ancora ipotesi differenti circa la loro origine e diffusione. alcuni autori propendono infatti per una origine locale dei materiali mentre altri ritengono che per la maggior parte le piroclastiti siano di provenienza esterna all’abruzzo. al fine di riconoscere caratteristiche comuni utilizzabili per una sommaria classificazione litologica delle piroclastiti, si è applicata una analisi discriminante (codice statistica) a tutti i campioni così da individuare 4 gruppi principali (gr1 = 2 campioni; gr2 = 3 campioni; gr3 =11 campioni; gr4 = 8 campioni (v. fig. 6). gli ultimi 2 gruppi sono sostanzialmente eguali se si eccettua il più alto contenuto in ca del gruppo 3 dovuto probabilmente ad apporti esterni successivi alla messa in posto del deposito. i 4 gruppi sono stati confrontati (tab. 6) con la composizione delle tufiti e dei tefra affioranti entro un raggio di poco più di un centinaio di chilometri dal piano locce, quali stiffe e oricola (tallini et al., 2002 ), pietrasecca (bertolani et al., 2005) e case picconetto in provincia di pescara (marcolini et al.,2003). un’ulteriore indagine è stata eseguita riportando i punti rappresentativi nella fig. 7, dove la % in ossidi di titanio è stata espressa in funzione della % di silice 180 tab. 5 risultati delle analisi chimiche totali eseguite su 24 campioni rappresentativi del riempimento della conca di piano locce. results of chemical total analysis carried out on 24 representative samples. campione mgo al2o3 sio2 p2o5 so3 k2o cao tio2 mno fe2o3 bao pl1 1,620 15,690 42,000 1,000 0,080 2,050 6,310 0,790 0,160 9,810 0,050 pl2 1,800 15,750 43,370 0,640 0,100 2,190 6,200 0,810 0,090 7,560 0,070 pl3 2,150 16,260 42,860 0,650 0,140 2,710 8,740 0,760 0,110 7,780 0,090 pl8 1,220 13,800 36,030 0,440 0,040 1,950 13,440 0,660 0,070 6,450 0,060 pl10 1,500 16,570 43,810 0,570 0,060 2,280 5,350 0,820 0,100 8,910 0,070 pl11 1,480 17,460 44,820 0,650 0,180 2,510 4,170 0,750 0,140 7,100 0,070 pl12 1,390 17,440 43,280 0,700 0,090 2,190 5,610 0,820 0,100 8,030 0,090 pl13 1,410 19,280 45,000 0,690 0,080 2,250 1,120 0,860 0,070 8,920 0,100 pl14 1,520 19,100 45,300 0,760 0,100 2,260 1,960 0,860 0,120 7,990 0,090 pl15 1,450 17,510 42,740 0,690 0,100 2,300 3,070 0,830 0,120 7,820 0,090 pl17 1,320 17,930 50,290 0,490 0,320 5,240 3,430 0,610 0,140 5,910 0,080 pl40 1,550 18,690 41,300 1,820 0,200 1,940 3,290 0,820 0,330 8,570 0,120 pl45 1,290 20,050 41,030 0,650 0,120 2,230 1,520 0,820 0,220 9,710 0,130 pl47 1,390 22,590 46,210 0,960 0,630 2,510 1,750 0,840 0,040 5,020 0,150 pl49 0,830 22,520 46,700 0,460 0,150 2,340 1,300 0,640 0,050 6,020 0,120 pl59 1,500 21,270 43,800 1,050 0,130 2,520 2,500 0,820 0,110 7,330 0,150 pl64 1,860 17,680 45,210 0,690 0,360 2,790 7,480 0,660 0,090 6,820 0,130 pl68 1,660 16,840 43,630 0,670 0,140 3,250 6,590 0,640 0,140 6,900 0,130 pl69 1,070 16,140 50,930 0,350 0,080 6,190 5,820 0,410 0,140 5,100 0,170 pl76 1,250 19,500 45,460 1,120 0,070 2,190 1,370 0,760 0,060 7,460 0,130 pl81 1,690 21,270 43,690 1,300 0,340 2,610 1,880 0,740 0,050 5,980 0,230 pl82 2,630 15,330 37,450 0,620 0,550 5,630 9,440 0,520 0,170 7,330 0,360 pl84 1,460 20,620 43,720 0,560 0,090 2,570 1,200 0,710 0,360 8,150 0,190 pl90 0,860 19,170 51,600 0,310 0,080 4,530 2,830 0,500 5,580 5,580 0,140 d. magaldi et al. secondo una rappresentazione a diagramma usata nello studio delle rocce effusive. in definitiva tabelle e grafico suggeriscono che esiste una discreta somiglianza tra la composizione media di pietrasecca e case picconetto con quella media del gruppo 3-4 di locce e tra quella media di stiffe (e forse oricola) e il gruppo 2; al contrario il gruppo 1, peraltro rappresentato solo da 2 campioni, risulterebbe differente da tutti gli altri. questi risultati tuttavia sono affetti da un elevato margine di incertezza in quanto l’alterazione subita ha senza dubbio provocato la perdita degli elementi più mobili, in conseguenza dei processi di pedogenesi e/o di diagenesi. allo scopo di accertare la provenienza dei materiali vulcanici è stato quindi necessario procedere ad una serie di determinazioni microanalitiche sul vetro, sui plagioclasi e sui pirosseni, utilizzando 16 campioni prelevati ad oltre 30 m di profondità, più freschi di quelli stratigraficamente sovrapposti e contenenti più abbondante materiale vulcanico (vetro, cristalli, e più di rado, frammenti litici di rocce effusive). i livelli vulcanici di piano locce comprendono ceneri fini e grossolane spesso ben selezionate (sorted). alcuni dei livelli apparivano più rimaneggiati, sia per la presenza di cristalli di quarzo eolico che di clasti carbonatici provenienti dai vicini versanti calcarei. le analisi al microscopio elettronico hanno evidenziato come il vetro della stragrande maggioranza dei livelli sia completamente alterato e quindi inutilizzabile per la classificazione chimica dei livelli stessi. solo il campione pl90 proveniente dalla base (78-80 m) della carota, ha dato risultati soddisfacenti. durante la elaborazione di questa ricerca, una indagine successiva condotta a maggiore dettaglio e finalizzata all’acquisizione nello stesso sito del contenuto pollinico della parte più superficiale della carota, ha incontrato un livello centimetrico di ceneri relativamente fresche a 5 m di profondità (livello denominato pl top). pertanto anche questo campione è stato preso in considerazione per la classificazione del vetro . in conformità di queste analisi (tab. 7), il livello pl90 può essere classificato come una latite-trachite. un attento esame dei dati analitici della tabella mostra tuttavia che, pur essendo le analisi nel loro insieme accettabili, presentano valori anormalmente bassi in 181 fig. 6 raggruppamenti (cluster) ottenuti tramite l’analisi discriminante (codice statistica) considerando come variabili il contenuto totale in ossidi. si evidenziano chiaramente 4 gruppi a livello 5 – 10. clusters derived from discriminating analysis (statistica software) using main oxides total content for the samples. there are at 5-10 level 4 main clusters. tab. 6 confronto dei cluster risultanti dalla analisi statistica (codice statistica) con la composizione chimica di alcune piroclastiti dei dintorni di l’aquila. comparison between clusters resulting by statistical analysis (statistica software) and chemical composition of some pyroclastic sediments from l’aquila neighbourhoods. locce pietrasecca oricola stiffe picconetto ossidi (%) gr1 gr2 gr3 gr4 media media media media sio2 36,74 50,94 43,62 44,13 42,37 50,03 48,58 45,46 tio2 0,59 0,51 0,75 0,80 0,81 0,95 1,10 0,95 al2o3 14,57 17,75 16,71 20,11 19,09 12,59 18,99 17,16 fe2o3 2,07 1,66 3,61 2,31 2,26 1,88 2,29 2,63 feo 4,82 3,87 4,07 5,39 5,27 4,40 5,36 6,14 mno 0,12 1,96 0,12 0,15 0,17 n.d. n.d. 0,20 mgo 1,92 1,08 1,68 1,36 3,05 1,74 1,80 3,95 cao 11,44 4,03 6,31 1,91 9,72 4,63 3,06 9,51 na2o n.d. n.d. n.d. n.d. 0,81 1,43 0,43 3,06 k2o 3,79 5,32 2,50 2,31 3,10 4,57 2,06 10,34 p2o5 0,53 0,38 0,70 0,87 0,42 n.d. n.d. 0,57 somma 76,58 87,50 80,07 79,34 87,08 82,21 83,69 100,00 genesi e significato del riempimento della depressione carsica ... sodio (na2o) e cloro (clo). valori così bassi sono indicativi di incipiente alterazione del vetro che, all’inizio dei processi tende a perdere elementi a largo raggio ionico quali il sodio e il cloro. ne deriva che la somma degli alcali usata nel diagramma di classificazione tas (fig. 8) risulta essere meno attendibile e sicuramente sottostimata rispetto ai valori originari. una correzione della somma degli alcali pari al 3÷4%, sposterebbe infatti la classificazione del vetro nel campo delle tefri-fonoliti e fonoliti (fig. 8). una composizione di questo tipo potrebbe tentativamente essere correlata con le eruzioni pleistoceniche del vulcano di vico, caratterizzate da attività esplosiva di 182 fig. 7 percentuale in ossidi di titanio in funzione della percentuale di silice. percentage of titanium oxide vs. silica percentage. tab.7 analisi del vetro vulcanico prelevato a 5 m di profondità (pl top) e di quello del livello pl90 a 78-80 m di profondità (bottom del sondaggio). a titolo di confronto sono riferite le analisi totali del campione rf95-7 prelevato in adriatico a 450 cm di profondità e quelle della media dei campioni appartenenti, secondo l’elaborazione statistica, al gruppo 2 (v.testo). composition of volcanic glass of pltop (5 m of depth) and of pl 90 sample (78-79 m of depth). as a comparison, total analysis of the sample rf95-7 from the 450 cm depth of adriatic sea and the average composition of the group 2 samples are referred. campioni : 1 2 3 4 5 6 7 8 9 10 media dev. st. rf 95-7 450 cm gruppo 2 sio2 56,11 57,59 58,06 59,17 58,68 58,15 59,81 58,77 57,93 61,11 58,54 1,344 58,27 50,94 tio2 1,31 0,79 0,64 0,57 0,58 0,60 0,28 0,72 0,67 0,21 0,64 0,299 0,44 0,51 al2o3 23,06 19,66 21,06 20,56 21,93 22,22 22,20 20,64 20,31 22,41 21,41 1,106 19,23 17,75 feotot 2,72 4,79 3,48 3,65 3,04 2,64 1,64 3,63 3,80 1,04 3,04 1,094 3,70 2,48 mgo 0,89 1,08 0,75 0,40 0,43 0,67 0,24 0,60 0,86 0,14 0,61 0,302 0,10 1,08 mno 0,10 0,14 0,06 0,18 0,08 0,00 0,00 0,17 0,10 0,00 0,08 0,068 0,65 1,96 cao 7,36 5,59 3,96 3,19 5,57 6,11 4,25 5,42 4,47 4,09 5,00 1,233 3,71 4,03 na2o 2,57 2,97 2,73 4,74 3,54 3,10 3,22 3,81 3,26 4,90 3,48 0,791 4,34 n.d. k2o 5,88 7,35 9,17 7,45 6,04 6,51 8,34 6,17 8,53 5,95 7,14 1,210 9,24 5,32 clo 0,00 0,04 0,10 0,10 0,11 0,00 0,00 0,06 0,07 0,15 0,06 0,053 0,32 n.d. somma 100 100 100,01 100,01 100 100 99,99 99,99 100 100 100 100 84,07 total alkali 8,45 10,32 11,90 12,19 9,58 9,61 11,56 9,98 11,79 10,85 10,62 13,58 alkali ratio 2,29 2,47 3,36 1,57 1,71 2,10 2,59 1,62 2,62 1,21 2,05 2,13 campioni : 1 2 3 4 5 6 7 8 media dev. st. sio2 45,38 46,63 46,5 45,12 44,64 47,62 46,08 45,9 45,98 0,887 tio2 0,92 0,88 0,68 0,96 0,89 0,64 0,85 0,81 0,83 0,106 al2o3 19,88 19,19 20,71 19,11 20,53 20,78 19,72 19,73 19,96 0,612 feotot 8,06 8 7,32 9,05 8,45 7,16 8 7,82 7,98 0,560 mno 0,33 0,46 0,07 0,26 0,37 0,25 0,3 0,14 0,27 0,116 mgo 1,26 1,3 1,29 1,56 1,25 0,78 1,49 1,36 1,28 0,218 cao 11,62 10,79 11,33 12,88 11,87 7,73 11,72 11,62 11,20 1,420 na2o 5,64 6,25 5,38 5,43 6,39 7,22 5,5 5,54 5,92 0,607 k2o 6,72 6,29 6,49 5,47 5,37 7,65 6,14 6,88 6,38 0,699 p2o5 0 0 0 0 0 0 0 0,08 0,01 0,026 clo 0,18 0,2 0,22 0,16 0,26 0,18 0,19 0,13 0,19 0,036 somma 99,99 99,99 99,99 100 100,02 100,01 99,99 100,01 100,00 total alkali 12,36 12,54 11,87 10,9 11,76 14,87 11,64 12,42 alkali ratio 1,191489 1,0064 1,20632 1,007366 0,840376 1,0595571,116364 1,241877 analisi vetro del campione pl 90 ( circa 80 metri) e del campione pl top (5 m ) pl 90 pl top d. magaldi et al. composizione trachitico-fonolitica (peccerillo, 2005). di conseguenza il campione pl90 potrebbe essere tentativamente correlato con le piroclastiti riconosciute in una carota marina dell’adriatico (livello rf95-7, 450 cm; fig. 8), datate intorno a 170.000 anni fa (calanchi et al., 2008). inoltre, la composizione media dei vetri del livello pl90 sembra abbastanza simile a quella (media) dei 3 campioni appartenenti al gruppo 2 (pl17, pl69 e pl90, tab. 7). il campione pl top è stato classificato come foiditico (fig. 8). sulla base della composizione del vetro, della paragenesi mineralogica (dominata da leucite e clinopirosseno, in assenza di plagioclasio; fig. 9) e delle analisi sem-eds sulle fasi minerali (tab. 7) può essere correlato con l’attività finale del vulcano dei colli albani, e più precisamente con l’eruzione dei peperini, datati a circa 36.000 anni fa (freda et al., 2005). gli altri livelli vulcanici appaiono troppo alterati per essere classificabili sulla base della chimica dei vetri, ma su alcuni di essi è stata effettuata una microanalisi delle fasi minerali (plagioclasi e pirosseni) riferita nelle tabelle 8 e 9, rispettivamente per i sialici e per i femici. la composizione dei minerali dei cinque campioni esaminati (pl48; pl55; pl60; pl64; pl69) indica una stretta affinità con le composizioni delle eruzioni dei vulcani campani (campi flegrei, ischia, procida e somma-vesuvio (peccerillo, 2005), con sanidino dominante nelle fasi sialiche e clinopirosseno in quelle femiche. forse potrebbero essere rappresentativi del gruppo 3-4 anche se il pl69 appartiene statisticamente al gruppo 2. due soli campioni (pl82 e pl74), uno dei quali rientra nel gruppo 1, sulla base della paragenesi mineralogica che contiene abbondante biotite, possono in prima approssimazione essere correlati con l’attività dei vulcani laziali (peccerillo, 2005). dei restanti sei livelli infine non è possibile ipotizzare la sorgente. la tab. 10 riassume le informazioni circa la descrizione e la provenienza dei 16 livelli vulcanoclastici considerati per l’analisi chimico-mineralogica più dettagliata. 5. discussione dei risultati i dati in precedenza esposti sembrano attestare in modo abbastanza chiaro, sia l’origine prevalentemente piroclastica dell’intero riempimento forse fino a notevole profondità, così come sembra avvenuto per il fucino dove un livello di cineriti, con uno spessore di circa 100 m, avrebbe una età di circa 500 mila anni (narcisi, 1995), sia l’età del livello più profondo raggiunto dal sondaggio (circa e forse più di 170.000 anni bp). nell’ipotesi che tutto il materiale piroclastico sia venuto dalla provincia comagmatica romana (apparati vulcanici del lazio e della campania) i depositi più recenti dovrebbero avere meno di 36.000 mila anni e addirittura alcune cineriti potrebbero essere di età proto-storica (sulpizio et al., 2008). anche sul significato paleo-climatico e ambientale da attribuire al deposito possono essere fatte solo considerazioni preliminari. lo studio integrato e multidisciplinare del quaternario ha da qualche tempo evidenziato le strette relazioni che intercorrono tra tipologia dei suoli e condizioni climatiche e biologiche esistenti durante le varie fasi più fredde e più calde dell’attuale (west, 1968; bowen, 1981; birkeland, 1984; mcfadden et al., 1986; birkeland, 1990). in europa settentrionale west (1968) propose la seguente relazione tra clima e suoli in un periodo di tempo compreso tra due “glaciali” successivi: suoli poco evoluti (cataglaciale) – terre brune (interglaciale) podzols sotto foresta (anaglaciale). si può quindi concludere che alcune caratteristiche del suolo riscontrabili a differente scala, da quella di campo a quella microscopica, possano suggerire eventuali cambiamenti nel clima del passato, purché 183 fig. 8 diagramma tas per i campioni pltop e pl90 .a titolo di confronto è mostrata anche la composizione del livello della carota adriatica. the tas classification diagram for some samples: pl top , pl90 and a pyroclastic sediment from the bottom of adriatic sea (450 cm of depth). fig. 9 – analisi al sem-eds su sezione sottile di un livello di tefra a 5 m di profondità (pltop): lc= leucite; cpx= clinopirosseno. sem –eds picture of thin section of sample pl top (5m depth); lc= leucite; cpx= clino-pyroxene. genesi e significato del riempimento della depressione carsica ... 184 ta b . 8 c om p os iz io ne c hi m ic a d ei fe ld sp at i d i a lc un i c am p io ni c on m ag gi or c on te nu to in m in er al i v ul ca ni ci t ra 3 0 e 80 m d i p ro fo nd ità . fe ld sp ar s ch em ic al c om p os iti on o f s am p le s co lle ct ed 3 0 to 8 0 m o f d ep th . a na lis i c hi m ic he d ei f el d sp at i o ss id i ( % ) p l 48 p l 55 p l 60 p l 64 p l 69 s io 2 47 ,9 51 ,1 53 ,7 52 ,2 50 ,9 63 ,8 63 ,7 64 ,6 46 ,5 65 ,0 64 ,6 64 ,6 64 ,7 65 ,2 63 ,1 45 ,9 49 ,4 63 ,7 64 ,2 65 ,1 66 ,8 66 ,2 a l 2 o 3 32 ,4 30 ,6 28 ,1 29 ,1 30 ,4 19 ,3 19 ,7 19 ,8 33 ,0 19 ,7 19 ,7 19 ,6 19 ,4 20 ,3 19 ,7 32 ,5 31 ,7 19 ,6 20 ,2 20 ,1 19 ,9 19 ,9 fe o to t 0, 6 0, 4 0, 5 0, 9 1, 0 0, 2 0, 4 0, 5 0, 7 0, 3 0, 3 0, 3 0, 3 0, 2 0, 5 0, 8 0, 7 0, 4 0, 3 0, 3 0, 4 0, 3 c ao 16 ,5 13 ,3 11 ,5 12 ,3 13 ,3 0, 5 1, 1 1, 1 16 ,7 0, 5 0, 9 0, 6 0, 5 0, 8 1, 2 16 ,9 14 ,7 1, 1 0, 4 0, 4 0, 0 0, 1 n a 2 o 2, 0 3, 6 4, 5 3, 9 3, 0 2, 0 3, 7 4, 0 1, 7 4, 7 4, 9 4, 6 5, 3 6, 9 3, 6 1, 6 2, 7 3, 7 7, 2 7, 3 6, 9 6, 8 k 2o 0, 2 0, 6 0, 9 0, 9 0, 7 13 ,5 10 ,6 9, 9 1, 3 9, 9 9, 6 10 ,3 9, 7 6, 4 10 ,6 1, 2 0, 6 11 ,3 7, 1 6, 6 6, 1 6, 6 to ta le 99 ,6 99 ,6 99 ,2 99 ,3 99 ,2 99 ,2 99 ,2 99 ,9 99 ,9 10 0, 0 10 0, 0 99 ,8 99 ,9 99 ,9 98 ,7 98 ,9 99 ,7 99 ,7 99 ,4 99 ,9 10 0, 0 10 0, 0 ta b . 9 c om p os iz io ne c hi m ic a d ei p iro ss en i d i a lc un i c am p io ni c on m ag gi or c on te nu to in m in er al i v ul ca ni ci t ra 3 0 e 80 m d i p ro fo nd ità . p yr ox en es c he m ic al c om p os iti on o f s am p le s co lle ct ed 3 0 to 8 0 m o f d ep th .. a na lis i c hi m ic he d ei p ir o ss en i o ss id i ( % ) p l 48 p l 55 p l 60 p l 64 p l 69 s io 2 48 ,7 47 ,6 49 ,0 50 ,5 50 ,7 52 ,7 50 ,5 51 ,2 49 ,9 50 ,8 50 ,2 51 ,2 52 ,5 51 ,3 53 ,1 51 ,5 51 ,5 51 ,6 5, 6 50 ,4 48 ,1 47 ,8 ti o 2 1, 4 1, 7 1, 2 1, 0 1, 3 0, 4 0, 8 0, 7 0, 7 1, 0 1, 1 0, 6 1, 4 1, 0 0, 3 0, 7 0, 6 0, 8 0, 7 0, 7 1, 4 1, 7 a l 2 o 3 5, 2 7, 3 6, 4 3, 1 4, 2 2, 1 2, 9 2, 0 3, 2 1, 3 2, 2 1, 5 0, 5 1, 3 2, 5 3, 6 3, 5 3, 4 2, 4 2, 6 5, 7 6, 2 fe o to t 8, 4 8, 1 7, 1 7, 2 7, 8 3, 7 9, 3 9, 2 7, 8 10 ,0 10 ,1 8, 7 23 ,4 9, 9 3, 7 4, 9 4, 8 7, 2 7, 8 7, 8 7, 6 7, 7 m no 0, 2 0, 1 0, 0 0, 1 0, 1 0, 1 0, 7 0, 9 0, 2 1, 4 1, 2 1, 1 1, 9 1, 5 0, 2 0, 1 0, 1 0, 2 0, 6 0, 4 0, 2 0, 1 m go 13 ,2 12 ,5 13 ,1 15 ,2 13 ,6 16 ,7 12 ,6 13 ,1 13 ,2 12 ,6 12 ,4 13 ,8 2, 4 12 ,5 16 ,5 15 ,6 16 ,4 14 ,3 15 ,1 15 ,1 14 ,2 14 ,0 c ao 22 ,4 22 ,4 22 ,8 22 ,3 22 ,0 23 ,7 22 ,3 22 ,0 23 ,8 20 ,3 21 ,5 22 ,0 8, 6 20 ,5 23 ,5 23 ,1 22 ,3 22 ,1 22 ,2 22 ,4 22 ,6 22 ,2 n a 2 o 0, 3 0, 2 0, 3 0, 3 2, 0 0. 1 0, 8 0, 7 0, 4 1, 6 1, 2 1, 0 8, 8 1, 6 0, 1 0, 1 0, 2 0, 3 0, 7 0, 6 0, 3 0, 3 to ta le 99 ,8 99 ,9 99 ,9 99 ,7 99 ,9 99 ,4 99 ,8 99 ,7 99 ,1 99 ,1 99 ,9 99 ,8 99 ,5 99 ,5 10 0, 0 99 ,7 99 ,4 99 ,9 10 0, 0 10 0, 0 10 0, 0 10 0, 0 d. magaldi et al. 185 tab. 10 descrizione riassuntiva e ipotesi di provenienza dei materiali vulcanici sulla base delle analisi chimico-mineralogiche eseguite su 17 campioni tra 5 e 80 m di profondità. short description of examined volcanic glass and provenance hypothesis for 17 samples 5 to 80 m of depth. campione profondità colore descrizione sorgente pl top 5,0 m n3 ceneri grossolane di colore grigio scuro-nero. l'analisi al binoculare mostra colli albani dark gray che le particelle sono poco vescicolate e porfiriche. ci sono cristalli sialici e (eruzione dei femici sciolti. l'analisi al microscopio elettronico mostra che il vetro peperini) è di composizione foiditica, con massa di fondo cristallina. la paragenesi 36 ka bp è dominata dalla leucite+clinopirosseno, con raro sanidino. pl 48 30-28,6 m 5yr 5/2 ceneri fini e grossolane di colore marroncino, compatte. l’analisi al binoculare la composizione pale brown mostra vetro, piccoli litici carbonatici e cristalli sialici e femici. l’analisi dei minerali al microscopio elettronico mostra che il vetro è completamente alterato. sembra indicare le composizioni delle fasi minerali indicano che la paragenesi dominante è una sorgente plagioclasio e clinopirosseno campana pl 49 31,2-30,6 m 10yr 8/2 ceneri fini di colore giallastro. l’analisi al binoculare mostra che il vetro è sconosciuta very pale scarso e molto alterato. presenza di cristalli sialici e femici. orange pl 51 32,2-31,8 m 5y 7/2 ceneri grossolane di colore grigio con abbondanti inclusi carbonatici. sconosciuta yellowish l’analisi al binoculare mostra che il vetro è scarso e molto alterato. deposito gray abbondanti cristalli femici e minori sialici. rimaneggiato in ambiente subaereo pl 55 35-33,9 m 5y 7/2 ceneri fini e grossolane mediamente compatte di colore grigio. la composizione yellowish l’analisi al binoculare mostra presenza di vetro e cristalli sialici e femici. dei minerali gray l’analisi al microscopio elettronico mostra che il vetro è completamente sembra indicare alterato. le composizioni delle fasi minerali indicano che la paragenesi una sorgente dominante è sanidino e clinopirosseno con minore plagioclasio. campana pl 60 39,4-36,4 m 10yr 6/2 ceneri grossolane sciolte di colore marroncino con piccoli inclusi carbonatici. la composizione pale l’analisi al binoculare mostra presenza di vetro e cristalli sialici e femici. dei minerali yellowish l’analisi al microscopio elettronico mostra che il vetro è completamente alterato. sembra indicare brown le composizioni delle fasi minerali indicano che la paragenesi dominante una sorgente è sanidino e clinopirosseno. campana pl 64 42,7-42,1 m 5y 7/2 cenere fine e grossolana compatta ma non cementata di colore grigio. la composizione yellowish l’analisi al binoculare mostra vetro mal conservato e cristalli sia sialici che femici. dei minerali gray l’analisi al microscopio elettronico delle fasi minerali mostra la presenza sembra indicare di sanidino, clinopirosseno e minore plagioclasio. una sorgente campana pl 66 44-43,3 m 5y 5/2 ceneri grossolane di colore grigio scuro. sconosciuta light olive l’analisi al binoculare mostra particelle molto arrotondate e presenza di deposito grey cristalli di quarzo di colore biancastro. rimaneggiato in ambiente subaereo pl 68 46-44,5 m 5y 7/2 ceneri fini e grossolane simili alle precedenti, di cui costituiscono la parte stessa eruzione light olive finale e probabilmente più rimaneggiata, come testimoniato dagli abbondanti del pl 69 gray clasti carbonatici del substrato inglobati dalle ceneri. pl 69 46,5-46 m 2.5y 7/2 ceneri fini e grossolane di colore grigio. ci sono clasti carbonatici del la composizione light gray substrato inglobati nelle ceneri. l’analisi al binoculare mostra vetro, dei minerali litici lavici e abbondanti cristalli sia sialici che femici. l’analisi al microscopio sembra indicare elettronico mostra che il vetro è completamente alterato. le composizioni una sorgente delle fasi minerali indicano che la paragenesi dominante è sanidino e clinopirosseno. campana. pl 72 54-52,15 m 10yr 6/4 ceneri fini ben selezionate di colore marroncino. il materiale è simile a quello sconosciuta light del livello precedente. il vetro è completamente alterato yellowish brown pl 73 56-54 m 10yr 5/6 ceneri molto fini e ben selezionate di colore marroncino. al binoculare si sconosciuta yellowish notano vetro e cristalli sialici e femici non abbondanti. l’analisi al microscopio brown elettronico mostra che il vetro è completamente alterato. pl 74 56,8-56,1 m 10yr 7/2 cenere fine e grossolana di colore grigio, con screziature di colore marrone. la paragenesi light gray l’analisi al binoculare mostra vetro, abbondanti cristalli di biotite, mineralogica cristalli sialici (sanidino) e femici (clinopirosseno). l’analisi al microscopio suggerisce una elettronico mostra che il vetro è completamente alterato. sorgente nei vulcani laziali pl 82 69,5-67,5 m 2.5y 6/1 ceneri grossolane di colore grigio. l’analisi al binoculare evidenzia la presenza la paragenesi gray di vetro e di molti cristalli di biotite, insieme ad altri cristalli femici mineralogica (clinopirosseni) e sialici incolori (sanidini) o lattiginosi. l’analisi al microscopio suggerisce una elettronico mostra che il vetro è completamente alterato. sorgente nei vulcani laziali pl 85 73-72 m 10yr 6/2 ceneri grossolane di colore marrone chiaro. al binoculare si distingue vetro sconosciuta pale lattiginoso, litici lavici e cristalli sialici e femici. alcuni cristalli sembrano deposito yellowish abrasi e rimaneggiati. presenza di alcuni clasti dal substrato carbonatico. rimaneggiato brown l’analisi al microscopio elettronico indica che il vetro è completamente alterato in ambiente e la composizione originaria non è ipotizzabile. subaereo pl 89 78-76,10 m 10yr 8/1 ceneri fini ben selezionate di colore chiaro. al binoculare si distingue vetro lattiginoso, sconosciuta white e piccoli cristalli sialici e femici. l’analisi al microscopio elettronico indica che il vetro è completamente alterato e la composizione originaria non è ipotizzabile. pl 90 79-80 m 5y 7/1 ceneri fini e grossolane di colore grigio chiaro. il deposito è addensato ma non attività del light gray cementato. presenza di lapilli accrezionali. al binoculare appare formato da vetro, vulcano di vico cristalli sialici ialini e femici. l’analisi al microscopio elettronico indica che il vetro ha più vecchia composizione trachitico-latitica a causa di un impoverimento in alcali dovuto ad di 170 ka bp alterazione incipiente. i cristalli sono prevalentemente sanidino e clinopirosseno genesi e significato del riempimento della depressione carsica ... capaci di una sufficiente persistenza durante le mutevoli condizioni ambientali (yaalon, 1971; birkeland, 1990). alcuni livelli, infatti, a circa 30 m di profondità mostrano alcune forme contorte (involutions). e’ quindi probabile che queste forme siano state determinate da processi periglaciali, che hanno agito su un suolo con qualche clay skin sul quale tuttavia non sono ancora state eseguiti analisi polliniche. al contrario alcune analisi polliniche, condotte puramente a titolo esplorativo da c.a. accorsi su alcuni campioni più ricchi di materia organica, rivelano momenti più freddi dell’attuale tra 45 e 67 m di profondità. in molti casi il diverso contenuto in argilla pedogenetica può indicare periodi con diversa umidità del clima (reheis, 1987 in birkeland, 1990 ). anche dalla sedimentologia risultano informazioni che vanno a corroborare i dati ottenuti dalla pedologia. secondo ortolani & pagliuca (in crescenti, 2005) i depositi alluvionali, che nel cilento seppelliscono reperti archeologici romani e medievali, sono indicatori di periodi freddo-umidi, al contrario delle sabbie di duna costiera che rappresenterebbero invece periodi più aridi. partendo da queste considerazioni si è voluto comprendere il significato delle variazioni del contenuto di argilla e di sostanza organica in rapporto alla profondità. come è noto da tempo, l’alterazione dei materiali piroclastici fini è generalmente molto veloce e può dare origine a minerali argillosi amorfi e cristallini quali allofane, imogolite, halloysite ed altri. l’argilla granulometrica dovrebbe quindi rappresentare, almeno in parte, minerali argillosi di neoformazione e la sua frequenza in relazione alla profondità, potrebbe indicare un diverso grado di alterazione del materiale primario, alterazione la cui entità è strettamente legata alla disponibilità di acqua e di silice e infine alla temperatura dell’ambiente circostante. può darsi quindi che il diagramma del rapporto limo/argilla in funzione della profondità, peraltro con andamento approssimativamente inverso a quello della % di sostanza organica (fig. 10) e quasi del tutto analogo a quello del vicino riempimento di piano lucchiano (magaldi et al., 2006) , possa interpretarsi come un indice paleo-climatico, dove i valori più bassi indicherebbero periodi più favorevoli alla pedogenesi e alla diffusione della vegetazione (e quindi più caldi e più umidi), al contrario dei valori più alti che potrebbero testimoniare periodi più freddi e probabilmente più aridi. l’aridità sarebbe provata dalla neoformazione di noduli e concrezioni di carbonato di calcio, presenti nei depositi situati tra i 30 e i 50 m di profondità. 6. conclusioni durante i l quaternario gran parte dell’italia centromeridionale fu investita da materiali cineritici di origine vulcanica provenienti per via eolica prevalentemente dai centri di emissione della provincia comagmatica romana (peccerillo, 2005), caratterizzata dall’elevato contenuto in potassio. le principali catene carbonatiche dell’appennino disposte all’incirca parallelamente alla costa tirrenica furono così ricoperte da coltri vulcanoclastiche in spessori variabilissimi, più spessi nelle zone vallive e nelle depressioni di origine carsica (m. simbruini, m. lepini, m. aurunci), dove il colluvionamento iniziato subito dopo la deposizione e proseguito intensamente in seguito determinò un notevole accumulo di materiali. ad esempio nella zona di capestrano (santa pelagia) un sondaggio privato sul riempimento di una conca carsica, ha raggiunto la roccia carbonatica dopo circa 150 m, attraversando una successione di depositi fluvio-lacustri e vulcanoclastici, a volte pedogenizzati. questo processo è stato particolarmente intenso sulla catena del gran sasso e sulle vallate immediatamente adiacenti sia a est che ad ovest del rilievo principale, dove la diffusa morfologia carsica ha agito come trappola e zona di conservazione dei depositi, rallentando così la normale azione erosiva agente sui versanti più acclivi. tutti i risultati ottenuti testimoniano chiaramente che la zona di piano locce è stata interessata in vari momenti del quaternario antico da una sequenza di eventi sedimentari (palustri e piroclastici) e pedogenetici, sicuramente iniziati prima degli ultimi 200mila anni, associati a variazioni climatiche in un ambiente di alta montagna, variazioni che sono evidenziate in particolare dall’andamento del contenuto in sostanza organica con la profondità e dalla sua relazione con il rapporto limo/argilla e infine dalle figure micromorfologiche, che in alcuni livelli sono sicuramente attribuibili a fenomenologie periglaciali. quando le condizioni climatico–vegetazionali consentirono l’instaurarsi di processi pedogenetici, si formarono suoli poco evoluti, fortemente condizionati da idromorfia quasi permanente. solo in pochi casi, verso il centro della successione, si sono osservate caratteristiche micromorfologiche sicuramente attribuibili a suoli più sviluppati, riferibili a intervalli di tempo di stasi più lunghi, forse con orizzonte argil l ico (aqualfs? boralfs?). al riempimento della depressione, 186 fig. 10 percentuale di sostanza organica dei campioni e andamento del rapporto limo/argilla in funzione della profondità di campionamento. organic matter and silt/clay ratio for the whole stratigraphyc column d. magaldi et al. insieme a quelli di limitati e temporanei corsi d’acqua torrentizi, hanno contribuito, sia pure in minima parte apporti colluviali e/o eolici da suoli maggiormente evoluti e di ambiente climatico differente (“terre rosse” tipo xeralfs o ustalfs ), ancora presenti come “suoli residuali ” nelle vallate vicine (magaldi & tallini , 2000). ringraziamenti il coordinatore-responsabile del progetto, finanziato con gli ultimi fondi del cluster c11 b del miur (ambiente terrestre) esprime la sua gratitudine alla direzione dell’ente parco nazionale del gran sasso e dei monti della laga per aver concesso l’esecuzione dei sondaggi e alla fondazione della cassa di risparmio di l’aquila per il notevole contributo corrisposto alcuni anni fa e destinato all’acquisto di un modernissimo microscopio da petrografia, strumento indispensabile per lo svolgimento della presente ricerca. un ringraziamento particolare alla dr.ssa francesca tescari per il contributo dato alla revisione della parte relativa alla micromorfologia del suolo e all’ing. danilo ranalli per la preparazione del cd fotografico. si ringraziano infine l’ing. bruno taddei e il per. ind. algerio giangiuliani, rispettivamente, per l’assistenza prestata alla esecuzione dei due carotaggi e al loro campionamento. bibliografia apat (2006) carta geologica d’italia alla scala 1:50.000: l’aquila. s.el.ca., firenze. bertini t., bosi c. & galadini f. (1989) la conca di fossa – s. demetrio nei vestini. in: società geologica italiana: elementi di tettonica pliocenico-quaternaria ed indizi di sismicità olocenica nell’appennino laziale-abruzzese. guida all’escursione. bertolani m., lugli s. & rossi a. (2005) studio petrografico delle grotte di attraversamento di pietrasecca ( l’aquila ). memorie dell’istituto italiano di speleologia, 5, 71-83. bertrand j.p. (1969) cours de pétrographie appliquée a l’étude des problèmes pétroliers. société des editions technip, paris. birkeland p.w. (1984) soil and geomorphology. oxford university press, n.y., 372 pp. birkeland p.w. (1990) soil-geomorphic research – a selective overview. geomorphology, 3, 207 -224. boari e. & conticelli s. (2007) mineralogy and petrology of associated mg-rich ultrapotassic shoshonitic and calc-alkaline rocks: the middle latin valley monogenetic volcanos, roman magmatic province, southern italy. the canadian mineralogist, 45, 1443-1469. bosi c. & bertini t. (1970) la geologia della media valle dell’aterno. mem. soc. geol. it., 9, 719-777. bosi c. & locardi e. (1991) vulcanismo meso-pleistocenico nell’appennino laziale-abruzzese. studi geologici camerti. vol .speciale, 2, crop 11, 319-325. bowen d.q. (1981) quaternary geology. a stratigraphic framework for multidisciplinary work. pergamon press, 237 pp. brewer r. (1964) fabric and mineral analysis of soils. j.wiley & sons, new york, 470 pp. brustur t. & jipa d.c. (2007) first record of the seismites in pliocene deposits from prahova valley. geo-eco-marina, 13, 139-142. bullock p., fedoroff n., jongerius a., stoops g., tursina t. & babel u. (1985) handbook for soil thin section description. waine research pub., uk, 152 pp. buol s.w., hole f.d. & mccracken r.j. (1980) soil genesis and classification. iowa university press, 406 pp. calanchi n. & dinelli e. (2008) tephrostratigraphy of the last 170 ka in sedimentary successions from the adriatic sea. j. volcanol. geotherm. res., 177, 81-95. colica a., lorenzoni p., magaldi d. & raglione m. (1993) geologia del quaternario e lineazioni nella conca tettonica tra oricola e carsoli. boll. serv. geolog. it., 102, 49-58. conticelli s., melluso l., perini g., avanzinelli r. & boari e. (2004) petrologic, geochemical and isotopic characteristics of potassic and ultrapotassic magmatism in central –southern italy: inferences on its genesis and on the nature of mantle sources. periodico di mineralogia, 73, 135-164. crescenti u. (2005) il contributo delle scienze geologiche per la valutazione dei cambiamenti climatici. xci congresso nazionale della società italiana di fisica (catania 26-9-2005, 1-10-2005). d’amico c., innocenti f. & sassi f.p. (1989) magmatismo e metamorfismo. utet, torino, 536 pp. d’argenio b., innocenti f. & sassi f.p. (1994) introduzione allo studio delle rocce. utet, torino, 162 pp. d’orefice m., graciotti r., capitanio f., stoppa f., rosatelli g. & barbieri m. (2006) il vulcanismo medio-pleistocenico dell’appennino laziale abruzzese: dalle peculiarità scientifiche agli aspetti applicativi. mem. descr. carta geol. d’it.,72 ; 767 driessen p.m. & dudal r. (1991) (eds.). the major soils of the world. agricultural university wageningen & katholieke universiteit leuven, 310 pp. ferrari g. & malesani p. (1973) micromorphology and mineralogy of the acid brown soils (umbrepts) in the meadows of the central calcareous apennine (abruzzo, italy). atti soc.tosc.sci.nat., mem., a, 80, 59-67. freda c., gaeta m., karner d.b., marra·f., renne p.r., taddeucci j., scarlato p., christensen j.n. & dallai l. (2005) eruptive history and petrologic evolution of the albano multiple maar (alban hills, central italy). bull. volcanol., 68 , doi 10.1007/s00445-005-0033-6 le bas m.j., le maitre r.w., streckeisen a. & zanettin p. (1986) a chemical classification of volcanic rocks based on the total alkali-silica diagram. journal of petrology, 27, 745-750. magaldi d. & tallini m. (2002) le unità di gestione del massiccio del gran sasso. report del consorzio di ricerca “gran sasso”, selca, firenze. magaldi d., benedetti g., lorè a. & lorenzoni p. (2006) due sondaggi profondi nei campi carsici del 187genesi e significato del riempimento della depressione carsica ... gran sasso: primi risultati e prospettive future. pubblicazione disat, 1, 2006, 9 pp. magaldi d. & tallini m. (2000) a micromorphological index of soil development for the quaternary geology research. catena, 41, 261-276. marcolini f., bigazzi g., bonadonna f.p., centamore e., cioni r. & zanchetta g. (2003) tephrochronology and tephrostratigraphy of two pleistocene continental fossiliferous succession from central italy. j.quaternary sci., 18 (6), 545-556. marianelli p. & sbrana a. (1998) risultati di misure di standard di minerali e di vetri naturali in microanalisi a dispersione di energia. atti soc. toscana sci. nat. resid. pisa, mem. serie a 105, 57–63. mcfadden l.d., wells s.g. & dohrenwend j.c. (1986) influences of quaternary climatic changes on processes of soil development on desert loess deposits of the cima volcanic field, california. catena, 13, 361-389. narcisi b. (1995) caratteristiche sedimentologiche, mineralogiche e geochimiche di un livello tufitico del pleistocene medio nei sedimenti della piana del fucino, italia centrale. il quaternario, 8 (1), 235-238. peccerillo a. (2005) plio-quaternary volcanism in italy. springer-verlag, 365 pp. retallack g.j. (2001) soils of the past. an introduction to paleopedology. blackwell science, oxford, 404 pp. selby m.j. (1993) hillslope materials and processes. oxford university press, 451 pp. stoops g. (2003) guidelines for analysis and description of soil and regolith thin sections. sssa, madison , usa, 184 pp. stoppa f. & rosatelli g. (2003) affioramenti vulcanici. in u. crescenti, e. miccadei , a. praturlon (eds.): guide geologiche regionali: abruzzo. a cura della società geologica italiana, be-ma, editrice milano, 338 pp. sulpizio r., bonasia r., dellino p., di vito m.a., la volpe l., mele d., zanchetta g. & sadori l. (2008) discriminating the-long distance dispersal of fine ash from sustained columns or near ground ash clouds: the example of the pomici di avellino eruption (somma-vesuvius, italy). j. volcanol. geotherm. res., 177, 263-276. tallini m., magaldi d., lorè a., reale e. & scozzafava m. (2002) geologia del quaternario e pianificazione territoriale della piana intramontana l’aquila –scoppito. geam , 1025, 55-67. tickel,f.g. (1965) the techniques of sedimentary mineralogy. elsevier, amsterdam, 220 pp. usda soil survey staff (1999) soil taxonomy. a basic system of soil classification for making and interpreting soil surveys. agricultural handbook no 436, washington dc. wakatsuki t., furukawa h. & kyuma k. (1977) geochemical study of the redistribution of elements in soil. in: evaluation of degree of weathering of transported soil materials by distribution of major elements among particle size fractions and soil extract. geochimica et cosmochimica acta, 41, 891-902. west r.g. (1968) pleistocene geology and biology. longmans, london and harlow yaalon d.h. (1971) soil forming processes in time and space. in d.h. yaalon (ed.): paleopedology .israel univ.press,jerusalem, 350 pp. yaalon d.h. (1987) saharan dust and desert loess: effect on surrounding soils. j.afr.earth sci., 6, 569-571. 188 ms. ricevuto l’11 maggio 2009 testo definitivo ricevuto il 5 agosto 2009 ms. received: may 11, 2009 final text received: august 5, 2009 d. magaldi et al. available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 31 (2), 2018, 195 205 the stratified growth of chieti from roman times to tomorrow: a new, geology-based conscience in city planning and renewal silvano agostini soprintendenza archeologica belle arti e paesaggio dell'abruzzo, l’aquila, italy corresponding author: s. agostini <silvano.agostini@beniculturali.it> abstract: human settlement grew around and at the foot of the hill of chieti partly conditioned by the local geological and geomorphological characteristics, and partly transforming them. the hill is vulnerable, due to its geological structure and geomorphological evolution. following the stratification of human activities and the intense construction activity on the hill, particularly after the second world war, monuments and both ancient and recent buildings suffered several stability issues. three of the city’s most important archaeological monuments are taken as emblematic of the interplay between local geology and human impact. the analysis shows that sound knowledge of how quaternary geological processes operated in time and space needs to become a permanent part of urban planning policy and urban renewal. in fact, the latter have to be strongly sensitive to the equilibrium between the impact of human activities and environmental geology, and able to predict how existing infrastructures respond to the effects of climate change (e.g. new rainfall regime). geological culture is the basis for redesigning the city with less, or no, use of concrete and more widespread use of bioengineering. . keywords: urban geoarchaeology, southern italy, abruzzi periadriatic region, plio-pleistocene marine deposits 1. introduction the geological and geomorphological characteristics of the town of chieti (teate marrucinorum in preroman and roman times) have conditioned and have been partly transformed by the impact and spread of human settlement around and at the foot of the hill. “super omnia, quae umquam audita sunt, erit prodigium in nostro aevo neronis principis ruina factum in agro marrucino, vetti marcelli e primis equestris ordinis oliveto universo viam publicam transgresso arvisque inde e contrario in locum oliveti profectis”, plinius secundus c., naturalis historia liber xvii 245. "a portent that will eclipse all those ever heard of occurred in our own day in the territory of the marruccini, at the fall of the emperor nero: an olive grove belonging to a leading member of the equestrian order named vettius marcellus bodily crossed the public highway, and the crops growing on the other side passed over in the opposite direction” (rackhaman, 1961). these words clearly show that the hill of chieti was known to be highly vulnerable and unstable already twenty centuries ago; for its characteristics it was the object of wonder, chronicles and a memory to be passed on. the vulnerability of the hill on which chieti stands is determined by its natural geological structure and geomorphological evolution. the geological context is not exclusive to the town; in fact, it characterises the entire mid-adriatic coastal hill belt (centamore & nisio, 2003; centamore et al., 2003). owing to its vulnerability, the hill of chieti always reacted directly or indirectly to the stratification of human activities with instability phenomena which affected the built fabric at any time and no matter what construction technique was used. we must first observe that hydrogeological instability turns into a major problem when urban space is developed, following a plan, or not, without any background knowledge of geology. in other words, repeated out burts of instability have always occurred not only due to the mistaken belief that the hill’s geological processes are static, rather than dynamic, but also adopting wrong strategies to contrast the unbalances caused by human impact which induced further acceleration of the processes. this error could also be perpetuated in the future. it is worth emphasising that the absence of geological culture does not imply lack of technology and technical solutions (land defences, reclamation) aimed at preventing and limiting the risks inherent in the management of chieti’s subsurface instability; rather, there has been prolonged absence of material and cultural responsibility in land management. today, special attention is devoted worldwide to the quality of life, not only in urban areas. this implies tackling hydrogeological issues, as well as the risks posed to property, and to life itself. we also need to plan and implement more appropriate, effective and allencompassing prevention measures and broad interventions. administrators and citizens need to recover a neglected geological culture, but this is no longer enough. much more must be done. https://doi.org/10.26382/amq.2018.13 196 2. the geological and geomorphological context the hill of chieti is located in southern abruzzi, in the peri-adriatic region of central italy. this area is characterised by a thick sequence of upper pliocene-middle pleistocene marine deposits, which cover the deep tectonic units of the northeast verging apennine fold and thrust belt (fig. 1). the plio-quaternary facies and morphostructural setting resulted from the complex interplay of tectonic faulting, uplifting and tilting, eustatic sea-level excursions, and climatic changes. particularly significant landforming processes were the lateral diversions of river courses, the topographic settings, as well as the formation of different orders of alluvial terraces, which are scattered at various elevations. quaternary regional uplift and surface deformation led some authors (pizzi, 2003; racano et al., 2016; racano et al., 2018) to consider the thrust system beneath the area still active like most peri-adriatic plateaus, the hill of chieti has a flat summit and flanks that slope down progressively more gently as we move to the underlying valleys. this physiography was created by modelling processes that acted over the last million years on the rocks of the local stratigraphic succession. the resulting stratigraphic setting controls both the groundwater circulation, with interstitial waters that spill over (or spring) at mid-slope elevation, and the incessant erosion and denudation processes. at first, the city developed following the hill's original morphology; later on, the hill was drastically transformed. the lithostratigraphic succession consists of four principal units (u1-u4) organized in two main groups (1 and 2). the first and second units (1 in fig. 2 and u1 and u2 in fig. 3) can be ascribed to the mutignano formation, (fmta, fmtc and fmtd according to carg subdivision in barberi et al., 2018a; barberi et al., agostini s. fig. 1 geological map of the abruzzi periadriatic belt (modified from racano et al., 2018) 197 fig. 2 simplified geo-lithological map: 1 sand with lenses of conglomerate (u2 and u2 cgl in fig. 3), gravel and lacustrine clays (u3 in fig. 3), colluvial and anthropic sediments (u1 cl and u1 r in fig. 3); 2 clays (u1 in fig. 3); tt roman theatre area, tp roman temples area, bc roman baths and cisterns area. a-b-c, d-b: trace of geological cross-section (fig. 3). the stratified growth of chieti from roman times to tomorrow: ... 2018b). part of the third unit (2 in fig. 2 and u3 in fig. 3) can be attributed to the mutignano formation and another part to the ripa teatina formation (fmtd and rpt according to carg subdivision in barberi et al., 2018a, barberi et al., 2018b). the fourth unit includes the colluvial cover, soils, fluvial deposits, as well as landslide (u4 cl in fig. 3) and antrophic deposits (u4 r in fig. 3). the base of the hill is completely encircled by lower pleistocene grey clays of submerged platform (bathyal to neritic environments), which form a hydrogeologically impermeable complex (u1 in fig. 3). the clays are followed, upwards, by a thin, vertically continuous and concordant layer of alternating sands and clays, and then by overlaying littoral sands, also dating to the early pleistocene (u2 and bottom of u3 in fig. 3). the u2 unit contains the main aquifer, which consists of a hydrogeological complex with medium to high permeability. the aquifer is fed by rainwater and today also by fluids leaking from water and sewage mains, old cisterns, modern water storage facilities and tanks, sometimes containing highly toxic liquids. differential erosional processes created very steep, almost vertical scarps in the hillslope profile (fig. 4), at the level of wellcemented sands at the top of the sandy unit (transition from u2 to u3 in fig. 3). many other artificial scarps, sometimes quite extended along the sides of the hill, were dug to create the foundations for buildings; this activity became more intense and aggressive in the post -war time (fig. 5). a unit of continental conglomerates, silts and sands fills discontinuities in the uppermost parts of the hill and crops out at the edge of the scarps. it rests on an unconformable surface that results from a former gentle uplift and modelling which occurred after the surfacing and eastward migration of the coastline at the end of the early pleistocene, about one million years ago. on top of the hill, the fourth unit is covered by remnants of red palaeosol with a truncated profile (fig. 6), which can be likely referable to lower middle pleistocene alfisols (barberi et al., 2018a). knowledge of the stratigraphy of the surface cover is very important for city planning and urban geology. the deposit consists of colluvium and accumulations from ancient landslides (u4 cl in fig. 4), as well as of material associated with human activities from various periods and recent landslides (u4 r in fig. 4). the mechanical and hydrogeological behaviour of this stratigraphically heterogeneous unit, which often includes both permeable and impermeable bodies of variable thickness, may be very different. although this unit represents the first substratum of the city, it has often been investigated with approaches that are inadequate in quaternary geology. this led to erroneous interpretations of the deposits, which have sometimes been ascribed to the second or even to the third unit. in particular, the colluvial cover contains each minor superimposed aquifers in which the water that derives from leaks of the town's water mains is canalized along lines of flow following the subsurface palaeo-drainage. these recent covering layers also contain human-made cavities (cisterns, tunnels, etc.), in which water accumulates causing damages to the road network, to the retaining walls as well as triggering landslides. this brief introduction on the geological and geomorphological setting of chieti is followed by a description of three cases, emblematic of the inter-relationship 198 fig. 3 geological cross sections. u4 r recent anthropogenic and colluvial sediments, u4 cl ancient colluvial and landslide deposits, u3 pebbles and lacustrine clays, u2 sands and lenses of conglomerate (cgl), u1 clays. >>>>> fig. 4 unstable areas map: 1 escarpment edge with structural control, 2 escarpment edge, 3 gully erosion, 4 rill erosion, 5 earth flow, 6 surficial deformation, 7 sliding landslide, 8 colluvial and anthropogenic sediments with thickness less than 2 m, 9 colluvial and anthropogenic sediments with thickness larger than 2 m, 10 incipient earthflow, 11 terraced alluvial deposits, 12 bedrock, 13 historic center and suburbs, tt the roman theatre area, tp roman temples area, bc roman baths and cisterns area. agostini s. https://dictionary.cambridge.org/it/dizionario/inglese-italiano/geological 199 the stratified growth of chieti from roman times to tomorrow: ... 200 fig. 5 urban modern buildings above and below the escarpment edge of the western hillslope. agostini s. fig. 6 red palaeosol (alfisols) on the erosion surface topping unit u3. 2. 1. the roman theatre area the roman theatre was built on top of the hill of chieti, on the edge of, and in part against, the western central slope (figs. 2, 3, 4). the slope was partly excavated in a fashion also observed elsewhere in italy and in the roman provinces (bieber, 1961; sartorio pisani & ciancio rossetto, 1994; martella & menozzi, 2008; vermeulen, 2018). this structure was located above the between the geology of the hill-city system and human impact. these areas have been studied in detail, because they are three of the town’s most important archaeological monuments. all three the sites were affected, already in ancient times, by extensive public works of urban transformation for the creation of teate marrucinorum. 201 fig. 8 retaining walls and drainage tunnels of the roman age on the edge of the western hill slope. fig. 7 the roman theater in the upper edge of the western hill slope. the left part of the ring corridor, the scaenae frons, the pulpitum and the orchestra are missing due to a landslide-associated collapse. the stratified growth of chieti from roman times to tomorrow: ... natural scarp produced by the differential erosion between unit u2 and part of unit u3 and underlying unit u1 (figs. 2, 3, 4). the geological instability of the area is demonstrated not only by the collapse of most of the ancient structures (fig. 7), but also by the general morphological irregularity which today characterises the upper margin of slope. the mass movements directly affect the soils (here considered in the geotechnical sense) at mid-hillside elevation above the clayey unit u1. the plastic deformations, subsidence and traction processes, which are still active today in the unit u1 deposits, led to the recession of the hill. the associated deformations and the widespread landslides (fig. 4) have created a precarious hydrological equilibrium on this intensely urbanised slope; they also affected the arrangement of strategic infrastructures, such as the town's principal water main. in fact, past and recent buildings were erected disregarding the active morphological evolution of the hillside and its natural process of auto-stabilisation through the dynamics of erosion, recession, transport and accumulation at the base of the slope. 2.2. the roman temples area the substrate of the area of the roman temples (agostini & romano, 2000) is characterized by material of variable thickness laying directly on the conglomerate sands of unit u2 (fig. 3). here the original land shape can be reconstructed based both on the archaeological structure, which originally lay underground, known as the roman tunnel, and on historical photos. the watershed line descended from the hilltop, passing slightly west of the site occupied by the roman temples. the temples were built against the slope of the hill, with the façades facing today's corso marrucino, which remained the town's main axis throughout the centuries. the current façade of the temples was originally the edifice’s rear side. today, in this area, the groundwater table is over 30 m below the ground level and therefore much lower than its level in the classical period, as confirmed by the depth of the temples' sacred well. in this area the characteristics of the unit u2 (sands and cemented conglomerated sands) favoured the excavation and construction of clad with bricks hypogeal environments and also of extensive underground quarries with broad and high chambers and pillars cut into the natural substratum. the access to the quarries was in particular at the foot of the western slope. archive studies show that the aforementioned chambers were used until about two centuries ago, when the artificial hypogea were still located at the edge of the city. today they lay below the 1950 to 1960 urban fabric and below the road network. in this area of the town, alongside the underground quarries, there are numerous tunnels, icehouses and wells; these structures were often discovered accidentally, exposed by instability phenomena. extensive hypogea have been identified under important public buildings following oral tradition, but most of all based on documents in historical archives and on the results of recent surveys. loss of historical memory, but also water and sewage leaking from defective pipes (modern ones, both known and unknown 16th and17th century 202 agostini s. fig. 9 retaining walls on the escarpment edge of the eastern hill slope. ones, as well as archaeological structures of the roman period), has caused repeated collapses and settlement of road surfaces, seepage in buildings and damage throughout the entire hillside. ironically, the way in which the romans designed and constructed the substructures on the slopes can still be seen in the area of the roman temples (fig. 8). uphill and downhill from the walls there was an organized drainage network designed to avoid overpressure of the saturated terrain on the buildings and generally capable to regulate the waters at the margin and along the side of the hill. 2.3. the roman baths and cisterns area the archaeological area of the roman baths and cisterns (agostini, 1987; agostini & campanelli, 1994; agostini et al., 1994; scichilone et al., 1987; ) is located about halfway up the eastern side of the hill of chieti. following the location of natural springs, the buildings were constructed in a natural thalweg, the head of which once reached today's piazza trento e trieste (figs. 2, 3, 4). like today, in the classical period the groundwater that discharged from perennial springs drained into the sediments of units u2 and u3, and flowed over the impermeable unit u1 located at about the same level as the base of cisterns. along the slope, the thalweg is filled with u4 cl unit deposits and the u4 r unit deposits. in fact, the jagged borders of the surface capping the hill were sculpted by the torrents that carved their way through the slopes. upstream, the heads of the torrents were wider than today. the thalweg was incised at the end of the late pleistocene and by the early holocene it was filled with fluvial deposits often over 20 m thick. the latter were subsequently covered by human-dumped debris, which sometimes reaches considerable thicknesses. further north of the archaeological area of the roman baths and cisterns, there are also thick prisms of palaeo and recent landslide accumulations. the colluvial unit often covers the typical scarps formed in the u2 and u3 sands. this side of the hill regularly retreated due to a succession of slope failures (fig. 9). the middle and lower part of the slope, which rests on the u3 clays, is affected by slow deformation that occasionally triggered landslide falls in the overlying unit. modern buildings largely load upon these sediments (fig. 10). on the right side of the thalweg, where the roman baths and associated cisterns are located, roman and late renaissance canalisations, including sections that had been restored in the 1960s and 1970s, are now crushed and deformed. the roman canalisations, which served the baths and which were fed by the water reserves in the underground cisterns, were subsequently used as extra-urban water sources to irrigate gardens and crops. similarly, the 18th and 19th century sewers, which had truncated numerous rooms of the roman baths, damaging and sometimes destroying them completely, have only recently been conveyed into a new pipeline. more generally, the poor state of the water network on the hillside above the archaeological site of the roman baths and cisterns imposed the implementation of specific remediation measures which saved the monument from accelerated and alarming deterioration. emblematic and impossible to resolve is that the surface of the vaults of 203 fig. 10 roman baths and cisterns area. the right portion of the roman bath collapsed following a sliding landslide (probably in the18th century) and recently reconstructed in the 1950s. the 19th century buildings and the road have been build over the cisterns while the urban modern buildings lie over the steep eastern hillslope and the escarpment edge. the stratified growth of chieti from roman times to tomorrow: ... 204 agostini s. the underground cisterns serve as the viaduct of the provincial road above. the walls of the cisterns built against the hillside act as a retaining wall on which there has been an alarming urbanization after the second world war (fig. 10). 3. conclusions the three cases briefly described, each from a different context (hilltop-roman theatre; hilltop margin upper part of the slopes-temples; mid-lower slopesbaths), are textbook examples of the interactions between natural sediments and anthropogenic cover types (buildings and spaces for human activity), of the ancient roman-preroman hilly town and successive urban development (bini et al., 2018; mozzi et al., 2018; vermeulen et al., 2018). a number of focused studies, either accomplished or underway, seized the opportunity of the presence of archaeological monuments to identify the most appropriate solutions to safeguard them. these researches accessed and processed large amounts of archival documents and reviewed information from over 300 wells. thanks to the wider perspective provided by these studies, we now have a historical memory, which can be used to decipher the relationships between environmental and urban geology, including its cultural aspects. the interpretation of the data shows that the geological context has received scarce, if any, attention in the past. also no care has been paid to the impact that the aggressive urban development could have on the vulnerable hydrogeomorphological system of the hill of chieti; the matter was rather conveniently dismissed as "the hydrogeological instability of the hill of chieti". no need to say that all the processes and events are considered to be a preexisting legacy, and not, as is in fact the case, the consequence of a lack of planning, or of recurrent planning issues. the interpretation of fresh information reveals also problems in the remediation techniques that have been employed. therefore the way in which the town is planned and renewed needs to be thoroughly revised; this cannot be postponed any longer. it cannot neglect genuine geological culture, especially aware of how quaternary geological processes operated in time and space and sensitive to the equilibrium between the impact of human disturbance and environmental geology. city planning and renewal projects must be able to predict to what extent existing infrastructure are capable to respond to the effects of climate change (e.g. new rainfall regime). this new conscience will be the basis for redesigning the town with less, or no, concrete and more attention to bioengineering. acknowledgments the author expresses his appreciation to the contribution provided by the two reviewers. references agostini s. (1987) acquedotti romani sotterranei in area mesoadriatica: tema in una ricerca archeologica integrata. atti 2° convegno nazionale di speleologia urbana “le cavità artificiali: aspetti storico -morfologici e loro utilizzo”, napoli, ed. cai, 139145. agostini s., campanelli a. (1994) la rete infrastrutturale di chieti romana. nuovi dati sull'urbanistica antica di teate marruccinorum.bollettino di archeologia subacquea, 2, 209-217. agostini s., romano j. (2000) prime indagini archeometriche su campioni di terrecotte architettoniche dai santuari dell’antica teate (chieti abruzzo). atti iv giornata di archeometria della ceramica, cnr irtec, 11-16. agostini s., carlino c., rossetti e. (1994) cisterne e terme romane di chieti monitoraggio ed interventi di restauro. atti viii congresso nazionale ordine nazionale dei geologi, 1-17. barberi r., biondi r., boncio p., calamita f., crescenti u., d’alessandro l., miccadei e., raffi i, rusi s., sciarra n. (2018a) carg foglio 361 chieti, note illustrative della carta geologica d'italia alla scala 1:50.000, pp.101. barberi r., berti c., biondi r., boncio p., brozzetti f., d’alessandro l., di matteo p., calamita f., crescenti u., d’alessandro l., miccadei e., pizzi a., raffi i., rusciadelli g., scisciani v. (2018b) carg foglio 361 chieti, carta geologica d'italia alla scala 1:50.000. bieber m. (1961) the history of the greek and roman theatre, princeton university press, usa, pp 1357. bini m., fabiani f., pappalardo m., schuldenrein j. (2018) special issue of geoarchaeology: urban geoarchaeology in the mediterranean basin. geoarchaeology,33, 3-12. doi: 10.1002/gea.21674 centamore e., nisio s. (2003) effects of uplift and tilting in the central-northern apennines (italy). quaternary international 101-102, 93-101. centamore e., dramis f., fubelli g., molin p., nisio f. (2003) elements to correlate marine and continental sedimentary successions in the context of neotectonic evolution of the central apennines. il quaternario/italian journal of quaternary sciences 16(1bis), 77-87. martella g., menozzi o. (2008) lo scavo del teatro romano di hatria picena e le fasi urbanistiche del quartiere. bar international series 1739, 521-526. mozzi p., ferrarese f., zangrando d., gamba m., vigoni a., sainati c., fontana a., ninfo a., piovan s., rossato s., veronese f. (2018) the modeling of archaeological and geomorphic surfaces in a multistratified urban site in padua, italy. geoarchaeology, 33, 67-84. doi: 10.1002/gea.21641 plinii naturalis historia plinio storia naturale libri ixxxvii, (1984), giardini editore, pisa, it, pp. 1338. pizzi a. (2003) plio-quaternary uplift rates in the outer zone of the central apennines fold and thrust belt, italy. quaternary international,101-102, 229-237. racano s., fubelli g., centamore e., bonasera m., dramis f. (2016) geomorphic signature of active tectonics in the southern abruzzi periadriatic hilly belt (central italy). egu general assembly 2016. https://onlinelibrary.wiley.com/action/dosearch?contribauthorstored=bini%2c+monica https://onlinelibrary.wiley.com/action/dosearch?contribauthorstored=fabiani%2c+fabio https://onlinelibrary.wiley.com/action/dosearch?contribauthorstored=pappalardo%2c+marta https://onlinelibrary.wiley.com/action/dosearch?contribauthorstored=schuldenrein%2c+joseph https://onlinelibrary.wiley.com/action/dosearch?contribauthorstored=mozzi%2c+paolo https://onlinelibrary.wiley.com/action/dosearch?contribauthorstored=ferrarese%2c+francesco https://onlinelibrary.wiley.com/action/dosearch?contribauthorstored=zangrando%2c+dorelia https://onlinelibrary.wiley.com/action/dosearch?contribauthorstored=gamba%2c+mariolina https://onlinelibrary.wiley.com/action/dosearch?contribauthorstored=vigoni%2c+alberto https://onlinelibrary.wiley.com/action/dosearch?contribauthorstored=vigoni%2c+alberto https://onlinelibrary.wiley.com/action/dosearch?contribauthorstored=sainati%2c+camilla https://onlinelibrary.wiley.com/action/dosearch?contribauthorstored=fontana%2c+alessandro https://onlinelibrary.wiley.com/action/dosearch?contribauthorstored=ninfo%2c+andrea https://onlinelibrary.wiley.com/action/dosearch?contribauthorstored=piovan%2c+silvia https://onlinelibrary.wiley.com/action/dosearch?contribauthorstored=rossato%2c+sandro https://onlinelibrary.wiley.com/action/dosearch?contribauthorstored=veronese%2c+francesca https://onlinelibrary.wiley.com/action/dosearch?contribauthorstored=rossato%2c+sandro geophysical research abstracts, 18, egu20164075. racano s., fubelli g., centamore e., bonasera m., dramis f. (2018) morphostructural evidences of active tectonics in the southern abruzzi periadriatic region. egu general assembly 2018. poster doi: 10.13140/rg.2.2.14467.40488. rackhaman h. (1961) pliny natural history with an english translation in ten volumes. volume v libri xvii-xix, cambridge, massachusetts, harvard university press, london uk, pp 1-568. sartorio pisani g., ciancio rossetto p. (1994) teatri greci e romani. alle origini del linguaggio rappresentato: censimento analitico. seat divisione stet, torino, it, i pp 1-502, ii pp 1-610, iii, pp 1-599. scichilone g., agostini s., rossi a., campanelli a., finarelli c. (1987) chieti: terme romane. memorabilia: il futuro della memoria, 3. laterza, it, 301307. vermeulen f., pincé p., weekers l., de dapper m. (2018) geoarchaeological study of abandoned roman urban and suburban contexts from central adriatic italy. geoarchaeology, 33, 85-99. doi: 10.1002/gea.21642. ms. received: marz 12, 2018 final text received: november 28, 2018 205 the stratified growth of chieti from roman times to tomorrow: ... https://onlinelibrary.wiley.com/action/dosearch?contribauthorstored=pinc%c3%a9%2c+possum https://onlinelibrary.wiley.com/action/dosearch?contribauthorstored=weekers%2c+lara https://onlinelibrary.wiley.com/action/dosearch?contribauthorstored=dapper%2c+morgan 206 base ambiente e clima della sicilia durante gli ultimi 20 mila anni alessandro incarbona1, mauro agate1, giuseppe arisco1, sergio bonomo2, giuseppe buccheri1, carolina di patti1, enrico di stefano1, antonino greco1, giuliana madonia1, federico masini1, daria petruso1, luca sineo3, rodolfo sprovieri1, giovanni surdi1, giuseppe zarcone1 1dipartimento di geologia e geodesia, università di palermo 2cnr, iamc, mazara del vallo (tp) 3 dipartimento di biologia animale, università di palermo corresponding author: a. incarbona <alessinc@unipa.it> riassunto: incarbona a. et al., ambiente e clima della sicilia durante gli ultimi 20 mila anni. (it issn 0394-3356, 2010). una serie di studi recenti ha fatto luce su alcuni punti della evoluzione del clima e dell’ambiente nel mediterraneo centrale, ed in particolare in sicilia, a partire dall’ultimo massimo glaciale (circa 20 mila anni fa). in questo articolo esaminiamo i dati dei lavori più significativi ed offriamo una loro visione d’insieme, con lo scopo di decifrare i cambiamenti ambientali che sono avvenuti nel passato, principalmente nei termini di temperatura, pattern atmosferico, entità delle precipitazioni, vegetazione e associazioni faunistiche. il clima dell’ultimo massimo glaciale fu caratterizzato da temperature particolarmente rigide e dalla frequente penetrazione di venti freddi di origine settentrionale, avvenuta persino durante la stagione estiva. bassi valori delle precipitazioni determinarono un pattern della vegetazione dominato da erbe ed arbusti, di tipo steppico o semi-steppico. a differenza di quanto è generalmente assunto, una serie di episodi di anomalia climatica, caratterizzati da temperature medie leggermente più basse ed una più intensa attività dei venti, potrebbero essersi ripetuti durante l’olocene, come testimoniato da studi micropaleontologici e geochimici condotti sui sedimenti del basso tirreno e del canale di sicilia. testimonianze nei record continentali di queste ricorrenti anomalie sono state trovate nella composizione isotopica degli speleotemi di una grotta nei pressi di palermo, datati a circa 8200 anni fa, e durante prolungati episodi di siccità registrati in tempi storici, durante la piccola età glaciale, presso erice (tp). molto complesso è il pattern della vegetazione, la cui struttura cambia in base a fattori locali, come ad esempio l’altezza sul livello del mare. tutti i dati sembrano comunque in accordo nell’indicare lo sviluppo di macchia mediterranea nelle zone costiere e di foreste decidue nelle zone interne e montane, già a partire dall’olocene più antico. l’impatto antropico sembra essere stato il fattore principale nel modellamento dell’attuale distribuzione della vegetazione in sicilia, attraverso l’uso intensivo del territorio per coltivazioni e pastorizia cominciato probabilmente 2700 anni fa, all’arrivo dei primi insediamenti coloniali dei greci. l’attività umana ha comunque agito sovrapponendosi ad un trend naturale di diminuzioni delle precipitazioni e di aridificazione, la cui spiegazione non è ancora completamente conosciuta. abstract: incarbona a. et al., environment and climate in sicily over the last 20, 000 years. (it issn 0394-3356, 2010). a series of recent studies shed light on the central mediterranean, and sicily, climate and environment, starting from the last glacial maximum (about 20 ka cal bp). in the present paper, we examine most of these works, in order to unravel environmental changes of the past, mainly in terms of temperature, atmospheric pattern, precipitation, vegetation and faunal associations. the climate of the last glacial maximum was characterised by very low temperature and by repeated northerlies penetration, even during summer. low precipitation values led to a steppeor semisteppe-like vegetation pattern, dominated by herbs and shrubs. episodes of climatic anomaly, characterised by lower temperature and strengthened wind activity, could have occurred during the holocene, as testified by micropaleontological and geochemical investigations carried out on the southern tyrrhenian sea and in the northern sicily channel. in the terrestrial record, there is evidence of drought at 8.2 ka cal bp, from the isotopic composition of a stalagmite recovered near palermo, and of prolonged drought intervals during the little ice age in the erice village (trapani). the vegetation pattern shows the development of mediterranean maquis in coastal sites and deciduous forests in sub-montane and montane regions, approximately from the holocene base. the human impact is the main factor that forced the present vegetation pattern, as a consequence of intensive land-use, which started about 2.7 ka cal bp, when greek colonies were first established. human activity is however superimposed on a natural trend towards aridity, with climatic forces still not fully understood. parole chiave: paleoecologia, paleoclimatologia, ultimo massimo glaciale, olocene, sicilia keywords: palaeoecology, palaeoclimatology, last glacial maximum, holocene, sicily il quaternario italian journal of quaternary sciences 23(1), 2010 21-36 1 introduzione negli ultimi anni, la preoccupazione per gli effetti catastrofici che potrebbero essere provocati dal riscaldamento globale si è diffusa nei media e nell’opinione pubblica. diversi studi hanno proposto previsioni sugli scenari futuri possibili e sull’impatto che l’aumento di temperatura avrebbe sull’ambiente. la conoscenza dell’impatto climatico sull’ambiente e l’affidabilità delle simulazioni al computer sono in gran parte basate su dati acquisiti nel corso di studi di paleoecologia e paleoclimatologia. nuove tecniche sono state sviluppate, mentre è cresciuto il numero di studi ad alta risoluzione, in grado di raccogliere e di descrivere i segnali biologici, chimici e fisici a scala secolare o addirittura decennale, in record marini e terrestri. in questo contesto, grande importanza hanno assunto gli studi sull’area mediterranea, particolarmente significativi poiché, in virtù della favorevole posizione geografica, permettono speculazioni sulle connessioni tra i sistemi climatici delle basse ed alte latitudini. diversi studi di rilevanza internazionale sono stati con22 a. incarbona et al. dotti sul settore centrale dell’area mediterranea o nella stessa sicilia. sono stati raccolti dati, per esempio, sugli isotopi stabili di sedimenti lacustri e di speleotemi, sui granuli di polline fossile e pure dati micropaleontologici e geochimici su sedimenti prelevati nei mari che circondano l’isola (fig. 1). la corretta interpretazione di questi dati ha permesso di ottenere una grande quantità di informazioni che in qualche modo riguardano anche l’ambiente della sicilia nel passato. scopo della presente nota è quello di fornire una visione d’insieme di questi dati e di offrire una traccia sull’evoluzione degli ambienti in sicilia, durante gli ultimi 20 mila anni (ka cal bp), a partire dall’ultimo massimo glaciale (last glacial maximum nella terminologia inglese). fig. 1 mappe che riportano le località dei record discussi nel testo. in alto, mappa batimetrica del mar mediterraneo. “a” rappresenta la località di lago grande di monticchio. in basso, mappa della sicilia che rappresenta uno zoom del riquadro riportato nella mappa soprastante. “1” rappresenta la località presso cui si trovano i laghi costieri della riserva naturale dei gorghi tondi”; “2” sito 963 dell’ocean drilling program; “3” grotta di carburangeli; “4” carota marina bs 79-38; “5” lago costiero biviere di gela; “6” lago di pergusa; “7” grotta di s. teodoro; “8” stretto di messina. maps of records discussed in the text. above, bathymetric map of the mediterranean sea. “a” is the location of lago grande di monticchio. below, map of sicily. “1” is the location of gorghi tondi coastal lakes; “2” ocean drilling program site 963; “3” carburangeli cave; “4” bs 79-38 marine core; “5” biviere di gela coastal lake; “6” pergusa lake; “7” s. teodoro cave; “8” messina strait. 2 l’ultimo massimo glaciale le condizioni ambientali e l’aspetto della sicilia 20 ka cal bp, durante l’ultimo massimo glaciale, dovevano essere radicalmente diverse rispetto a quelle odierne. il livello del mare era posto circa 110 metri al di sotto di quello attuale, con ovvie ripercussioni sull’aspetto fisiografico dell’isola. l’estensione totale doveva essere maggiore di circa 17000 km2 (circa 43100 km2 contro i 25883 km2 odierni) mentre l’estremità nordorientale dell’isola era connessa all’italia peninsulare, permettendo il libero transito delle faune continentali ed all’isola di malta (fig. 2a). è radicata nell’immaginario comune una condizione di estremo freddo durante l’ultimo periodo glaciale. tutte le informazioni in nostro possesso confermano che condizioni climatiche ostili siano esistite anche in sicilia, anche se solo raramente è stato possibile ottenere una stima quantitativa sulla temperatura dell’aria. per esempio, dati di temperatura dell’aria in altre stazioni mediterranee suggeriscono che in sicilia la temperatura media annua dovesse essere più bassa di 7-8°c (kuhlemann et al., 2008). un’idea forse più precisa di quanto l’ambiente potesse essere più freddo è deducibile da studi di geochimica organica condotti sui sedimenti del tirreno meridionale, recuperati ad alcune decine di chilometri dalla costa settentrionale siciliana (fig. 1). la ricostruzione della temperatura delle acque, riportata secondo una media annuale, ha previsto valori di 12-13°c per la parte terminale dell’ultimo periodo glaciale (sbaffi et al., 2001, 2004). questo dato impressiona, alla luce dei valori medi della temperatura delle acque del tirreno meridionale odierni, stimabili come poco inferiori a 20°c, anche se è sovrastimato (differenza di 8-9°c) rispetto ad uno studio che si basa su dati micropaleontologici (hayes et al., 2005). l’indicazione di una differenza di temperatura meno significativa proviene dalle masse d’acqua del canale di sicilia. le associazioni a foraminiferi planctonici, organismi unicellulari molto sensibili alle condizioni delle masse d’acqua in cui vivono, suggeriscono infatti che le acque superficiali fossero più fredde di 4-6°c durante il periodo glaciale (sprovieri et al., 2003, 2006; hayes et al., 2005) (fig. 3). sempre nel canale di sicilia, i dati di abbondanza delle alghe unicellulari chiamate coccolitoforidi mostrano come durante l’ultimo periodo glaciale non vi fosse traccia di un profondo e stabile termoclino stagionale (di stefano & incarbona, 2004; incarbona et al., 2008a, b). il termoclino si forma durante il periodo tardo primaverile-estivo quando, in mancanza di significativi fenomeni di perturbazione atmosferica, l’atmosfera cede calore agli strati superficiali delle acque marine. questi, riscaldandosi, diventano più leggeri e tendono a galleggiare sugli strati sottostanti. man mano che la stagione estiva avanza, il riscaldamento coinvolge uno spessore sempre maggiore di acque e raggiunge di solito una profondità di alcune decine di metri. la mancanza di un profondo termoclino stagionale implica sia un minore contrasto di temperatura tra atmosfera e superficie del mare (che, in particolare per il periodo glaciale, significa temperatura dell’aria più fredda in estate) sia la presenza di fenomeni di perturbazione atmosferica (cioè forti venti ed episodi di tempesta), significativi persino nella stagione estiva. la circolazione atmosferica nel bacino 23ambiente e clima della sicilia ... mediterraneo, ed in particolare nel settore centro-occidentale, presenta un controllo stagionale. quest’area è sotto l’influenza dei venti occidentali carichi di pioggia durante il periodo invernale. in estate, a causa dello stabilirsi dell’anticiclone delle azzorre, i venti occidentali soffiano più a settentrione e questo provoca un regime di alta pressione e di generale siccità. la situazione generale della circolazione atmosferica nell’emisfero settentrionale durante il periodo glaciale è registrata nelle carote di ghiaccio della groenlandia (dansgaard et al., 1993; mayewski et al., 1997; ngrip members, 2004). alti valori degli ioni na+ nelle carote di ghiaccio sono stati osservati durante periodi in cui il ciclone dell’islanda ha valori di pressione particolarmente bassi e quindi la circolazione atmosferica invernale nel nord atlantico permette il trasporto del na+ contenuto nel sale marino verso la parte centrale della groenlandia. alti valori dello ione k+ sono invece dovuti a periodi in cui l’anticiclone siberiano è particolarmente intenso. alti valori di entrambi gli ioni sembrano in buona correlazione tra loro, indicando momenti in cui la circolazione atmosferica nell’emisfero settentrionale era rafforzata (meeker & mayewski, 2002) e periodi di espansione del vortice polare (o’brien et al., 1995; mayewski et al., 1997). durante il periodo glaciale, visti i valori molto più alti di questi due ioni nelle carote di ghiaccio (fig. 3), è possibile ipotizzare che la circolazione atmosferica fosse molto più intensa di quella attuale. in particolare è probabile l’azione più intensa e prolungata dei venti occidentali che oggi costituiscono il più comune fenomeno di perturbazione atmosferica nel settore centrale del mediterraneo. è probabile altresì che l’arrivo delle fredde masse d’aria dell’anticiclone siberiano, che oggi raggiungono quest’area oltrepassando i balcani, avvenisse molto più di frequente. un’ulteriore conferma della maggiore attività dei venti che spiravano sul bacino mediterraneo arriva sia da studi sull’altezza della linea di equilibrio dei ghiacciai (kuhlemann et al., 2008) che da quelli sulla circolazione oceanografica del mar mediterraneo. il sistema di circolazione delle acque di questo mare si sviluppa su tre livelli ed è legata alla produzione di acque di fondo che avviene nel bordo settentrionale del bacino, principalmente nel golfo del leone e nel mare adriatico. l’acqua di fondo si forma durante brevi episodi in cui venti di provenienza settentrionale soffiano con grande forza (poem group, 1992; millot, 1999). tutti i dati in nostro possesso sono concordi nell’indicare come durante l’ultimo periodo glaciale la circolazione delle acque nel mediterraneo fosse notevolmente rafforzata, il che implica una maggiore produzione di acque di fondo innescata da una più intensa e prolungata azione dei venti nella porzione settentrionale del bacino (rohling et al., 1998; cacho et al., 2000; moreno et al., 2004; sierro et al., 2005; frigola et et al., 2008). lo studio dei sedimenti e dei pollini fossili del lago di pergusa offre un’istantanea di quella che doveva essere la vegetazione ed il regime delle precipitazioni in sicilia 20 ka cal bp. la vegetazione sembra essere stata caratterizzata dalla scarsa presenza di alberi mentre erano estremamente comuni piante erbacee ed arbustive relativamente basse come l’artemisia o quelle della famiglia delle chenopodiaceae, indicative di un ambiente aperto di steppa o semi-steppa (sadori et al., 2008). l’ambiente di steppa, sebbene con piccole 24 fig. 2 mappe della sicilia che rappresentano uno zoom del riquadro riportato nella mappa di figura 1. fig. 2a, f isiografia della sicil ia quando il livello del mare era più basso di 118 m, durante l’ultimo massimo glaciale; fig. 2b, fisiografia della sicil ia quando i l livello del mare era più basso di 90 m, durante la transizione tra ultimo periodo glaciale e olocene. fig. 2c, fisiografia della sicilia quando il livello del mare era più basso di 13 m, nel periodo medio olocenico. maps of sicily. fig. 2a, physiography of sicily during the last glacial maximum, when the sea level was at -118m; fig. 2b, physiography of sicily during the t r a n s i t i o n between the last glacial and the holocene, when the sea level was at -90m; physiography of sicily during the middle holocene, when the sea level was at -13m. a. incarbona et al. 25 fi g. 3 c ur ve d ii nd ic at or ic lim at ic o/ am b ie nt al ir el at iv e ag li ul tim i2 0 ka ca lb p ci rc a, og nu na p ro ie tt at a su lp ro p rio m od el lo d ie tà (k a ca lb p ). d a si ni st ra ,r ec or d d el δ18 o d el le ca ro te d ig hi ac ci o gr oe nl an d es in g r ip ,i nd ic at or id el la te m p er at ur a d el l’a ria in q ue lla re gi on e (n g r ip m em b er s, 20 04 ); c ur ve p al eo cl im at ic he a na nn of os si li ca lc ar ei e a fo ra m in ife ri p la nc to ni ci d el s ito o d p 96 3, p er fo ra to ne lc an al e d is ic ili a (s p r o v ie r i et al ., 20 03 ;d i s te fa n o e i n c a r b o n a ,2 00 4) ;v ar ia zi on id ia b b on d an za d eg li io ni k + e n a+ ne lle ca ro te d ig hi ac ci o d el la g ro en la nd ia g is p 2 (o ’b r ie n et al ., 19 95 ;m a y e w s k i et al ., 19 97 ); v ar ia zi on id el le p er ce nt ua li d ig ra nu li d ip ol lin e ar b or eo ne is ed im en ti d il ag o g ra nd e d im on tic ch io (a ll e n et al ., 19 99 ). la co lo nn a a si ni st ra in d ic a il im iti tr a l’u lti m o p er io d o gl ac ia le ,i lb øl lin ga lle rø d ,l o y ou ng er d ry as e l’o lo ce ne . c lim at ic /e nv iro nm en ta lp ro xy cu rv es ov er th e la st 20 ky r b p . fr om th e le ft , δ18 o of g re en la nd ic e co re s (n g r ip m em b er s, 20 04 ); p al ae oc lim at ic cu rv es b as ed on ca lc ar eo us na nn of os si ls an d p la nk to ni c fo ra m in ife ra fr om o d p s ite 96 3, s ic ily c ha nn el (s p r o v ie r i et al ., 20 03 ;d i s te fa n o an d i n c a r b o n a ,2 00 4) ;a b un d an ce va ria tio ns of k + an d n a+ in g is p 2 g re en la nd ic e co re s (o ’b r ie n et al ., 19 95 ;m a y e w s k i et al ., 19 97 ); p er ce nt ag e va ria tio ns of ar b or ea lp ol le n gr ai ns fr om la go g ra nd e d im on tic ch io (a ll e n et al ., 19 99 ). th e co lu m n on th e le ft sh ow s b ou nd ar ie s am on g la st gl ac ia lp er io d ,b øl lin ga lle rø d ,y ou ng er d ry as an d h ol oc en e. ambiente e clima della sicilia ... 26 variazioni dovute a fattori locali, sembra essere stato un elemento comune dell’europa meridionale, essendo stato riconosciuto per esempio nella penisola iberica, in italia meridionale ed in grecia (allen et al., 1999; sanchez goñi et al., 1999; tzedakis et al., 2003; roucoux et al., 2005). è interessante però notare come alcune specie vegetali mesofile e termofile di alberi delle angiosperme, sebbene in quantità molto limitate, siano sopravvissute in questo ambiente così ostile. la sicilia sembra quindi avere agito come una sorta di area di “rifugio” per questi alberi, favorendo la rapida ricolonizzazione del mediterraneo centrale, non appena le condizioni climatiche migliorarono (sadori et al., 2008). l’ambiente di steppa, oggi tipico per esempio della siberia sudoccidentale o del canada meridionale, non implica solo temperature rigide ma anche e soprattutto valori delle precipitazioni estremamente scarsi. valori fortemente ridotti delle precipitazioni sono stati dedotti dai risultati di analisi geochimiche che hanno preso in considerazione il rapporto degli isotopi dell’ossigeno nei sedimenti del lago di pergusa (zanchetta et al., 2006; sadori et al., 2008). ulteriori conferme della valenza arida del clima provengono dai dati della fauna continentale a mammiferi e da evidenze paleoantropologiche. tra i l pleniglaciale superiore ed il tardoglaciale (tra circa 25 e 15 ka cal bp) si verifica un elevato turn over tassonomico come dimostrano i dati relativi alle estinzioni e comparse per dispersione dei due complessi faunistici (cf) riferibili a questo intervallo di tempo, il cf grotta di san teodoro – pianetti ed il successivo cf di castello (d’amore et al., 2009; petruso et al., in stampa). la fase di acme glaciale costituisce probabilmente un evento particolarmente favorevole per gli scambi faunistici tra la sicilia e la terraferma permettendo l’arrivo dal sud della penisola di nuove popolazioni di cervo rosso, di uro, e forse del cavallo equus ferus e portando all’estinzione tutti i taxa endemici. nella suddetta transizione si estinguono l’elefante di taglia media paleoloxodon mnaidriensis, le forme endemiche di taglia moderatamente ridotta di cervo rosso e di uro e i carnivori come la iena maculata delle caverne e l’orso bruno. e’ già scomparso, probabilmente anche l’unico taxon ad affinità decisamente boreale presente sull’isola, il bisonte di steppa siciliano (bison priscus siciliae). gli elementi sopravvissuti testimoniano che il clima presentava ancora caratteri di aridità come attestato dall’asino delle steppe europeo (equus hydruntinus) e dal roditore terricola del savi [microtus (terricola) ex gr. savii] ma non ci sono indicatori di climi freddi. la costante presenza del cervo rosso e del cinghiale indicano tuttavia la locale diffusione di copertura arborea in aree di rifugio (agnesi et al., 1997; bonfiglio et al., 2000). la fauna a mammiferi tardoglaciale, inoltre, mostra notevoli affinità con le faune coeve del sud della penisola italiana ed, in particolar modo, con quelle del versante tirrenico (masini et al., 2008; petruso et al., in stampa). l’elevato turn over riscontrato e l’affinità con le faune coeve peninsulari sono il risultato dello scambio faunistico con la penisola calabra, facilitato da un ponte emerso. le condizioni descritte sopra, basate sui dati raccolti in record terrestri e marini, sono perfettamente compatibili con i risultati che provengono da modellizzazioni (general circulation model), volte alla descrizione del clima e dell’ambiente in europa durante l’ultimo periodo glaciale. sebbene i risultati di queste simulazioni debbano essere interpretati con cautela e valutati criticamente, dato che dipendono fortemente dal numero delle variabili e dei valori che vengono inseriti nel sistema, esse hanno il vantaggio di offrire una stima quantitativa dei diversi parametri climatico-ambientali che vengono presi in considerazione. il quadro ottenuto dipinge l’europa meridionale (al di sotto di 45°n di latitudine) come estremamente fredda ed arida, con temperature più basse di 2-7°c (valutate durante la stagione estiva e durante quella invernale) e precipitazioni ridotte di 1,5-5 mm/giorno, rispetto ad oggi. la simulazione in questione, mostra anche una forte attività dei venti provenienti dai quadranti occidentali ed un pattern della vegetazione quasi esclusivamente costituito da erbe ed arbusti (barron & pollard, 2002). 3 la transizione tra l’ultimo periodo glaciale e l’olocene: il periodo della deglaciazione il riscaldamento prodotto durante il periodo di transizione tra l’ultimo glaciale e l’olocene, durato circa 3 mila anni (tra 14,7 e 11,6 mila anni fa), è il risultato dell’aumento dei valori dell’insolazione, in risposta alle variazioni dell’orbita della terra attorno al sole. questo intervallo è stato un momento di riorganizzazione del sistema climatico che ha coinvolto variazioni nel volume delle calotte di ghiaccio, nella circolazione oceanica, della quantità di gas serra nell’atmosfera ed ovviamente della temperatura media globale del pianeta (broecker, 1998; petit et al., 1999; martin et al., 2002; skinner et al., 2003; skinner & shackleton, 2005). la transizione tra ultimo periodo glaciale e olocene non è avvenuta con un riscaldamento graduale, ma attraverso due brusche fluttuazioni climatiche non controllate dalle variazioni dell’orbita terrestre, chiamate bølling-allerød (fluttuazione calda) e younger dryas (fluttuazione fredda) (fig. 3). bølling-allerød e younger dryas sono le ultime di una serie di oscillazioni climatiche ad alta frequenza che si sono ripetute ogni 1.5 mila anni durante l’ult imo periodo glaciale nell’emisfero nord (rohling et al., 2003; ngrip members, 2004). non è chiaro quali siano i meccanismi climatici che hanno innescato le oscillazioni ad alta frequenza nell’emisfero nord. l’ipotesi più accreditata prevede il ciclico arresto o il brusco rallentamento della circolazione delle acque dell’oceano atlantico, provocato da variazioni nel contenuto salino delle acque delle alte latitudini, il cui effetto avrebbe comportato variazioni nella quantità di calore trasportato dalle basse alle alte latitudini (broecker et al., 1990). una serie di studi recenti ha dimostrato che è possibile riconoscere la presenza delle fluttuazioni climatiche di scala suborbitale anche nel mediterraneo. questi episodi sembrano essere simultanei a quelli precedentemente riconosciuti nei record delle carote di ghiaccio della groenlandia e dei record marini atlantici, probabilmente per fenomeni di teleconnessione, cioè per il rapido trasferimento di calore attraverso fenomeni di tipo atmosferico (rohling et al., 1998; cacho et al., 1999, 2000; sbaffi et al., 2001, 2004; buccheri et al., 2002; comborieu nebout et al., 2002; moreno et al., a. incarbona et al. 2002; rohling et al., 2002; pérez-folgado et al., 2003; sierro et al., 2005; frigola et al., 2008). in particolare, nel canale di sicilia, nei pressi della costa meridionale dell’isola, è stato possibile riconoscere l’intera sequenza di fluttuazioni stadiali (condizioni di clima più freddo e arido) ed interstadiali (condizioni di clima più caldo e umido), succedutesi durante gli ultimi 115 ka cal, sulla base di analisi micropaleontologiche e geochimiche (sprovieri et al., 2003, 2006; sprovieri et al., 2007). il riscaldamento iniziale delle acque superficiali avvenuto alla base del bølling-allerød può essere valutato in circa 5°c nel mar tirreno meridionale, sulla base dei dati degli alchenoni (sbaffi et al., 2001) e di circa 3-4°c nel canale di sicilia, sulla base delle associazioni a foraminiferi planctonici (sprovieri et al., 2003, 2006). poco più di 1000 anni dopo, in coincidenza dello younger dryas, le temperature di questi mari sarebbero di nuovo crollate fino a valori pienamente glaciali (fig. 3) (sbaffi et al., 2001; sprovieri et al., 2003). come per le fluttuazioni climatiche suborbitali precedenti, è possibile associare condizioni relativamente più umide per la pulsazione calda del bølling-allerød e di estrema aridità per quella fredda dello younger dryas (sprovieri et al., 2003, 2006; di stefano & incarbona, 2004; sprovieri et al., 2007). la cronologia dei sedimenti recuperati presso il lago di pergusa mostra uno scarso controllo cronologico che impedisce di affermare con certezza che l’intervallo della deglaciazione sia stato registrato (sadori & narcisi, 2001). non è quindi possibile avere una testimonianza diretta di come la vegetazione in sicilia si sia evoluta e di quali siano stati i valori delle precipitazioni. tuttavia una cronologia sicura è stata stabilita per gli ultimi 12,8 mila anni e sottolinea la transizione verso un ambiente molto meno arido e lo sviluppo progressivo di boschi e foreste al passaggio tra lo younger dryas e l’olocene (zanchetta et al., 2006; sadori et al., 2008). dati con risoluzione sufficiente per cogliere i cambiamenti della vegetazione avvenuti alla base dell’intervallo di deglaciazione nell’area mediterranea esistono in diverse carote marine. generalmente essi riportano il passaggio da un ambiente aperto di tipo semi-desertico, registrato durante l’ultimo glaciale ad uno in cui la vegetazione arborea divenne molto più abbondante, attribuibile alle prime fasi del bølling-allerød (e.g. zonneveld, 1996; combourieu-nebout et al., 1998; magri & parra, 2002; tzedakis et al., 2003). un record pollinico di eccezionale valore, riguardante gli ultimi 130 ka cal bp, è stato recuperato in basil icata (ital ia meridionale) a lago grande di monticchio (fig. 1) (allen et al., 1999; brauer et al., 2007; allen & huntley, 2009). uno dei caratteri più sorprendenti riguarda i rapidissimi cambiamenti della vegetazione, avvenuti talvolta in meno di 200 anni. in questi sedimenti lacustri sono state registrate le variazioni nella composizione della vegetazione durante il periodo della deglaciazione (fig. 3). la parte terminale dell’ultimo periodo glaciale è caratterizzato da una vegetazione tipica di un ambiente freddo di steppa, simile a quello già discusso per la carota pg 1 del lago di pergusa. a partire dalla base del bølling-allerød può essere osservato il graduale aumento di granuli di polline arboreo e la trasformazione verso un ambiente misto di steppa e boschi (wooded steppe). l’ambiente al culmine di questo intervallo, è quello tipico di una foresta temperata. il ritorno verso il clima freddo ed arido dello younger dryas è segnato da un pattern della vegetazione con condizioni miste di steppa e bosco (allen et al., 1999). il tipo di vegetazione cambia in risposta a fattori locali come per esempio altitudine, precipitazione e presenza di microclimi. è quindi assolutamente non plausibile che l’associazione pollinica di lago grande di monticchio sia rappresentativa delle condizioni della vegetazione in sicilia. tuttavia, in virtù della vicinanza geografica e dell’appartenenza allo stesso pattern climatico-atmosferico, è ragionevole immaginare che la vegetazione in sicilia possa avere avuto una risposta simile a quella dell’italia meridionale. è quindi possibile che ci sia stato un aumento della vegetazione arborea e la presenza di aree con foreste durante il bøllingallerød, ed una nuova fase di regressione verso un ambiente aperto di tipo steppico o semi-steppico durante lo younger dryas. solo nuovi dati ad alta risoluzione, relativi ai resti di pollini depositati in sedimenti continentali della sicilia o in sedimenti dei mari che la circondano, potranno chiarire l’evoluzione della vegetazione in questo intervallo temporale. all’inizio del periodo di deglaciazione, tra circa 14 e 15 ka cal bp, il livello del mare (l.m.) era posto a circa 90 m al di sotto della quota odierna (lea et al., 2002). la sicilia aveva ancora un’estensione maggiore rispetto a quella odierna, stimabile in circa 33 mila km2, ma rispetto all’ultimo periodo glaciale, gran parte della connessione all’isola di malta doveva risultare sommersa (fig. 2b). una importante considerazione sulle variazioni del l.m. in questo intervallo di tempo riguarda i modi ed i tempi dell’apertura di un braccio di mare attraverso lo stretto di messina. i dati batimetrici dello stretto di messina mostrano la presenza di un possibile corridoio di bassa profondità, oggi posto a circa 72 m al di sotto del l.m., tra le località di punta pezzo e ganzirri. diversi studi hanno fornito stime dei tassi di sollevamento nella zona dell’arco calabro-peloritano, generalmente comprese tra 0,5 e 2,5 mm/a (e.g. montenat & barrier, 1987; di stefano & branca, 2002; de guidi et al., 2003; antonioli et al., 2006a). dati più recenti riportano dei valori di 1,07 mm/a e ≤ 0,95 mm/a (antonioli et al., 2006b) rispettivamente per i tassi di sollevamento regionale della sicilia nord-orientale (s. alessio) e della calabria meridionale (scilla). all’entità di questo sollevamento regionale potrebbe essersi aggiunto un importante contributo “co-sismico”, dovuto all’azione di faglie. in particolare, nell’area dello stretto di messina, l’azione tardo-olocenica della faglia di scilla avrebbe aumentato il tasso di sollevamento fino a 2,1 mm/anno (ferranti et al., 2007, 2008). un sottile braccio di mare tra la sicilia e l’italia potrebbe dunque essersi iniziato a formare tra 15,9 e 11,6 ka cal bp (fig. 4), quando il livello del mare si attestò tra -89 e -50 m rispetto alla quota attuale (lea et al., 2002), anche se è difficile fare ipotesi su come e quando questa separazione possa avere realmente costituito un ostacolo per le migrazioni della fauna. sebbene sia possibile che sporadiche testimonianze dell’uomo in sicilia, come indicato dai reperti di riparo di fontana nuova (ragusa), possano essere riferite alla cultura aurignaziana delle fasi iniziali del paleolitico superiore (tra 32 e 29 ka cal bp, con misure 27ambiente e clima della sicilia ... di radiocarbonio convenzionale) (chilardi et al., 1996), è durante questo intervallo temporale, che in termini di cultura materiale umana viene chiamato epigravettiano, che vi sono le prime certe evidenze fossili umane e che si assiste al primo boom demografico in sicilia (piperno, 1997; vigliardi, 1997). in particolare, il ritrovamento di sette inumati nella grotta di s. teodoro (acquedolci, messina) può essere considerato come la prima evidenza consistente della presenza dell’uomo in sicilia. recentemente, un’analisi ams di radiocarbonio effettuata sul più rappresentativo di questi scheletri (l’individuo st1, esposto presso il museo geologico “g. g. gemmellaro” del dipartimento di geologia e geodesia dell’università di palermo), ha dato un’età di 14,75 ka cal bp (età calibrata) (incarbona et al., in preparazione), confermando precedenti ipotesi archeologiche e stratigrafiche (graziosi, 1947; vigliardi, 1968; segre & vigliardi, 1983; sineo et al., 2002). la reale importanza del sito e della sua gente nel panorama delle popolazioni antiche siciliane e il ruolo di questi individui nella composizione di un back-ground genetico ancestrale sono ancora non valutabili. l’ipotesi corrente è che il primo consistente popolamento umano dell’epigravettiano abbia portato ad una prima dispersione presumibilmente sulle direttrici costiere settentrionali dell’isola, verso le falesie occidentali. ipotizzando una dispersione sporadica di piccoli gruppi in contatto saltuario possiamo immaginare un primo popolamento coerente da un punto di vista popolazionistico (e genetico) che avrebbe lasciato alcune testimonianze litiche sulla costa settentrionale, presso il riparo del castello, nelle falesie del promontorio di s. vito lo capo ed altre, il cui inquadramento cronologico e la cui relazione temporale con i precedenti è però ancora da definire, tra cui probabilmente i siti rupestri dell’addaura (palermo) e delle isole egadi. un’attenta valutazione e nuovi studi con metodologie di morfometria geometrica di crani, di paleogenetica (dna antico) ed isotopiche potranno contribuire alla definizione dei rapporti tra le popolazioni antiche (siciliane e continentali), nonché tra quelli intercorsi tra gli individui epigravettani ed i cacciatori mesolitici che hanno popolato intensamente, migliaia di anni dopo, le coste settentrionali e occidentali dell’isola (d’amore et al., 2009; luca sineo, dati non pubblicati). per quanto riguarda le faune a mammiferi, durante la transizione tardoglaciale – olocene antico, si disperdono nuovamente sull’isola popolazioni di lupo e volpe, che sostituiscono le forme residenti dal pleistocene medio, e arrivano alcuni mammiferi mai 28 fig. 4 grafico con le variazioni eustatiche del livello del mare, espresse in metri, registrate durante gli ultimi 200 ka cal (lea et al., 2002) in ascissa, ed il tempo (ka cal bp) in ordinata. gli intervalli di tempo riguardanti le ultime due terminazioni glaciali (t i e t ii) sono approssimativamente indicati. la linea spessa tratteggiata indica le variazioni che il corridoio, posto oggi a -72 m di profondità nello stretto di messina, potrebbe avere subito durante gli ultimi 20 ka cal assumendo un tasso di sollevamento tettonico regionale di 2mm/anno (vedi paragrafo 3). la linea sottile punteggiata è invece relativa all’ipotesi della totale stabilità di questo corridoio. l’area racchiusa tra la linea tratteggiata e la curva eustatica presuppone la presenza di un braccio di mare tra sicilia ed italia peninsulare. plot of eustatic sea level variations, in metres, recorded over the last about 200 kyr (lea et al., 2002), versus time (kyr bp). the time interval of the last two terminations (ti and tii) is indicated. the thick dashed line shows variations in the corridor, today located at 72 m depth in the messina strait, assuming a uplift rate of 2 mm/yr (see paragraph 3). the thin dotted line shows variations in the corridor in case of tectonic stability of the area. the area between the thick dashed line and the thin dotted line implies the presence of a submerged sector between sicily and italian peninsula. a. incarbona et al. documentati prima sull’isola, come la lontra, il coniglio, il ghiro comune e l’arvicola d’acqua (sarà, 1998; petruso et al., in stampa). questi dati suggeriscono fortemente che il clima, più umido e caldo, avrebbe favorito la riforestazione dell’isola. la diffusione del cervo rosso e del cinghiale mostrano la tendenza del clima al miglioramento con la diffusione della copertura arborea (agnesi et al., 1997). inoltre, l’arrivo della lontra, dell’arvicola d’acqua e del gliride, attestano che il clima aveva assunto un carattere temperato-umido e che nel paesaggio si era diffusa una copertura arborea. la riforestazione e la risalita del livello del mare che potrebbe avere determinato una riduzione delle pianure costiere, habitat preferito dei grandi ungulati, portando alla definitiva estinzione dell’equide idruntino. 4 l’olocene dal punto di vista fisiografico, l’aspetto della sicilia doveva essere già molto simile a quello attuale a partire da circa 7,4 ka cal bp (fig. 2c), quando il l.m. era risalito fino a -13m (lea et al., 2002). i l cl ima dell’attuale periodo interglaciale, l’olocene, cominciato circa 11700 anni fa (walker et al., 2008), ha probabilmente impresso un importante accelerazione all’evoluzione sociale e culturale umana. il clima più mite rispetto al precedente periodo glaciale ha permesso alle popolazioni dell’europa centrale e del bacino mediterraneo di occupare territori precedentemente interessati dai ghiacciai della calotta euroasiatica. la migrazione di queste popolazioni è uno degli elementi chiave per la rapida diffusione di informazioni, tra le quali quelle relative alle prime attività agricole (cavalli-sforza & cavalli-sforza, 1993). si è creduto a lungo che il clima olocenico fosse stato fortemente stabile, con un unico episodio di raffreddamento avvenuto 8,2 ka cal bp. questa considerazione era principalmente dovuta alla stabilità degli indicatori climatici delle carote di ghiaccio della groenlandia, uno tra i registri migliori e più accurati di cui si dispone. l’unico episodio di raffreddamento atmosferico, stimato in circa 6°c, fu dedotto dalle variazioni del δ18o (fig. 3) (alley et al., 1997). in realtà già negli anni ’70 era stata sottolineata una possibile forte instabilità del clima dell’olocene, dato il rapido susseguirsi di fasi di avanzamento e ritiro dei ghiacciai perenni europei (denton & karlèn, 1973). l’esistenza di una variabilità climatica ad alta frequenza all’interno dell’olocene è stata recentemente dimostrata attraverso il ritrovamento di livelli di “ice rafted detritus” (ird) depositatisi dopo lo scioglimento di iceberg nel nord atlantico subpolare (fig. 5) (bond et al., 1997, 2001). la quantità di granuli di ird, sebbene molto meno abbondante rispetto agli episodi dell’ultimo glaciale (bond et al., 1992) è risultata comunque significativa dal punto di vista statistico. successivamente la presenza di anomalie climatiche oloceniche è stata riconosciuta in un gran numero di registri sedimentari marini e continentali di entrambi gli emisferi (fig. 5) (mayewski et al., 2004). studi recenti sui sedimenti prelevati nei mari che circondano la sicilia confermano che i fenomeni di instabilità climatica dell’olocene hanno interessato anche quest’area del mediterraneo. variazioni della temperatura nelle acque superficiali del tirreno meridionale (sbaffi et al., 2001) e variazioni del 10-15% della specie di nannofossile calcareo florisphaera profunda nella parte settentrionale del canale di sicil ia (incarbona et al., 2008a), sebbene basate su cronologie indipendenti, delineano un quadro di episodi di anomalie climatiche che ben si accorda con il record delle variazioni di ird nel nord atlantico (fig. 5), utilizzato come riferimento a livello globale. gli episodi di raffreddamento registrati nelle acque superficiali del tirreno meridionale sono sincroni ad episodi registrati nel mare di alboran, sebbene più freddi di 1.5-2°c per l’azione di venti più intensi provenienti dai quadranti settentrionali (cacho et al., 2001, 2002). anche le diminuzioni di abbondanza di f. profunda possono essere spiegate attraverso fenomeni di circolazione atmosferica più intensa, che avrebbero provocato la presenza di una stratificazione meno profonda e più debole nelle acque estive (di stefano & incarbona, 2004; incarbona et al., 2008a, b, c). poiché in sicilia non esistono barriere fisiografiche significative, i fenomeni atmosferici avvenuti nel tirreno meridionale potrebbero essere stati avvertiti immediatamente nel canale di sicilia. ciò spiega la buona correlazione tra gli episodi di anomalia climatica della carota bs79-38 e quelli del sito 963 e implica che gli stessi fenomeni atmosferici debbano avere avuto un impatto anche sull’ambiente continentale dell’isola. gli episodi di anomalia climatica dell’olocene si sono ripetuti ogni 1500 anni, in modo simile a quanto osservato durante l’ultimo periodo glaciale, anche se diversi dubbi persistono circa l’azione di un’unica forzante climatica. l’ultimo degli episodi di anomalia climatica olocenica è conosciuto come piccola età glaciale (little ice age) ed è stato registrato approssimativamente tra il 1550 ed il 1800. due sono le evidenze scientifiche dell’impatto della piccola età glaciale in sicilia, o meglio di quella che è conosciuta come la sua fase principale (xvi-xix secolo) (holzhauser, 2005; bradley, 2008; wanner et al., 2008). nel primo lavoro, silenzi et al. (2004) riportano l’abbassamento di circa 2°c della temperatura delle acque superficiali nel mar tirreno meridionale tra la fine del 1500 e l’inizio del 1800 ad, basandosi sulle analisi geochimiche delle scogliere a vermetidi di capo gallo (palermo). molto originale è l’articolo di piervitali & colacino (2001), i quali documentano periodi di prolungata siccità tra la fine del 1500 e l’inizio del 1900, attraverso il numero di processioni religiose ‘ad petendam pluviam’, cioè perché piovesse, presso erice (trapani). questi studi dimostrano come l’abbassamento delle temperature e la diminuzione delle precipitazioni durante la piccola età glaciale furono fenomeni che riguardarono anche la sicilia. la storia della vegetazione olocenica in sicilia sta cominciando ad essere delineata in dettaglio, grazie allo studio dei sedimenti lacustri presentati molto recentemente, che costituiscono contributi scientifici di grande valore. come accennato nel paragrafo precedente, il pattern della vegetazione in sicilia ha subito profonde modificazioni a partire dall’inizio dell’olocene, in risposta all’aumento dei valori dell’insolazione, della temperatura e delle precipitazioni. nelle regioni più interne e sub-montane, rappresentate dal record sedimentario del lago di pergusa, posto a 667 m sul livello del mare (m s.l.m.), una coper29ambiente e clima della sicilia ... tura forestale si sviluppò gradualmente e raggiunse il suo culmine a circa 10 ka cal bp. queste foreste erano caratterizzate da una forte prevalenza di querce decidue e da meno frequenti alberi sempreverdi, come il leccio (sadori & narcisi, 2001; sadori & giardini, 2007; sadori et al., 2008). ancora più in alto, per esempio nelle regioni montane delle madonie e dei nebrodi (al di sopra di 1200 m s.l.m.), la vegetazione era probabilmente costituita da foreste a faggio, mescolati con il cerro, il rovere e l’abete (tinner et al., 2009). da questo momento in poi, la vegetazione andò sempre più diradandosi, seguendo un generale trend di aridificazione. nelle regioni costiere della sicilia meridionale invece, rappresentate dai record di biviere di gela e di gorgo basso (fig. 1), il cambiamento più significativo che avvenne a 10 ka cal bp, riguardò l’iniziale espansione di arbusti e cespugli tipici della macchia mediterranea, soprattutto rappresentati da lentisco, ma anche da tamarice, palma nana, ginepro, erica, efedra, cisto e fillirea (noti et al., 2009; tinner et al., 2009). solo a partire 30 fig. 5 curve di indicatori climatico/ambientali relative agli ultimi 12 ka cal bp circa, ognuna proiettata sul proprio modello di età (ka cal bp). da sinistra, variazione del numero di granuli litici nell’oceano nord atlantico settentrionale (bond et al., 1997; 2001). la linea intera mostra le piccole variazioni oloceniche su una scala espansa. le sigle b1-b8 indicano i cosiddetti cicli di bond che sono assunti come riferimento globale per le variazioni climatiche oloceniche; variazioni percentuali della specie di nannofossile calcareo f. profunda nel sito odp 963, perforato nel canale di sicilia (incarbona et al., 2008a); variazioni della temperatura delle acque superficiali nella carota bs 79-38, prelevata nel tirreno meridionale, basate sull’analisi degli alchenoni (sbaffi et al., 2001), le sigle c1-c5 indicano gli episodi di raffreddamento più intensi. in grigio, gli intervalli di anomalie climatiche oloceniche registrate in numerosi record sedimentari marini e continentali (mayewski et al., 2004). climatic/environmental proxy curves of the last 12 kyr bp. from the left, variations in the number of lithics (ice rafted detritus) in the northern north atlantic ocean (bond et al., 1997; 2001). the black line shows holocene variations on an expanded scale. b1-b8 indicate the so-called bond cycles, often used as a global reference for holocene climate changes; percentage variations of calcareous nannofossil species f. profunda at odp site 963, sicily channel (incarbona et al., 2008a); sea surface temperature changes recorded in marine core bs 79-38, southern tyrrhenian sea, based on alkenone analysis (sbaffi et al., 2001). c1-c5 indicate cooling episodes. grey bands shows intervals of holocene climatic anomalies recorded in marine and terrestrial records (mayewski et al., 2004). a. incarbona et al. da 7 ka cal bp, una vera foresta di alberi sempreverdi si espanse nelle regioni costiere, principalmente attraverso la fioritura di alberi di leccio e olivo (noti et al., 2009; tinner et al., 2009). queste foreste resistettero fino a 2,7 ka cal bp, quando avvenne la definitiva trasformazione del pattern della vegetazione in un ambiente molto più aperto di macchia e di prateria. diversi record continentali, che includono dati di pollini fossili, di geochimica dei sedimenti lacustri e di speleotemi, indicano una brusca diminuzione delle precipitazioni, a partire dal periodo medio-tardo olocenico (sadori & narcisi, 2001; sauro et al., 2005; frisia et al., 2006; zanchetta et al., 2006; sadori et al., 2008). dato lo scarso controllo cronologico dei record considerati è difficile ipotizzare quale fenomeno climatico possa avere portato alla riduzione delle precipitazioni. è comunque possibile che un ruolo di primo piano lo abbia avuto lo spostamento della zona di convergenza intertropicale (itcz) verso sud e la diminuzione dell’attività dei monsoni, avvenuto dopo circa 5.5 ka cal bp, che provocò la desertificazione e fenomeni di estrema aridità in africa settentrionale (de menocal et al., 2000; gasse, 2000). sebbene non sia ancora chiaro il legame tra l’attività dei monsoni dell’africa occidentale, la circolazione meridiana della cella di hadley e l’attività degli anticicloni sulla regione mediterranea (gaetani et al., 2007), non è da escludere che questo fenomeno abbia avuto ricadute sul mediterraneo centrale e sull’entità delle precipitazioni in sicilia. il trend di progressiva riduzione delle precipitazioni ha avuto un ovvio impatto sull’aspetto della vegetazione, a cui si è sovraimposto il forte impatto antropico dovuto all’uso del territorio a fini agricoli e di allevamento. lo studio di minuscoli granuli di carbone (indicativi della frequenza degli incendi naturali e di quelli prodotti dall’uomo, su scala locale e regionale) suggerisce che l’attività umana possa essere iniziata nell’olocene medio (sadori et al., 2008; tinner et al., 2009), ma essa fu certamente un elemento centrale nel modellamento del paesaggio e della vegetazione a partire dalle colonizzazioni dei greci (2.7 ka cal bp), quando le attività agricole e di pastorizia divennero intensive (noti et al., 2009; tinner et al., 2009). è evidente che senza l’uso intensivo del territorio da parte dell’uomo, l’aspetto della vegetazione nell’isola sarebbe molto diverso ed ancora sostanzialmente caratterizzato da foreste e boschi di alberi decidui e sempreverdi sia nella parte interna che nelle zone costiere (noti et al., 2009; tinner et al., 2009). i dati paleoambientali deducibili dalle faune a mammiferi continentali poco aggiungono al quadro climatico delineato. il grande turnover riconosciuto alla transizione olocene antico recente (tra 11,5 e 5,7 ka cal bp) evidenzia un aumento di diversità che non è imputabile a particolari effetti climatico-ambientali ma che è verosimilmente dovuto agli effetti diretti o indiretti dell’attività umana che ha arricchito la teriofauna di specie antropocore (sarà, 1998; petruso et al., in stampa). l’uomo del meso-neolitico oltre ad aver portato direttamente all’estinzione alcuni taxa come l’uro per attività venatoria ha contribuito all’estinzione indiretta di altri a causa dell’introduzione di nuovi competitori e predatori, dell’addomesticazione e, come discusso in precedenza, apportando modifiche agli habitat con deforestazioni ed introduzione di specie vegetali aliene (petruso et al., in stampa). 5 conclusioni prendendo spunto da una serie di lavori recenti, abbiamo presentato una sintesi dei cambiamenti ambientali che sono avvenuti in siclia durante gli ultimi 20 mila anni. condizioni climatiche estremamente ostili caratterizzarono la sicilia durante l’ultimo massimo glaciale, con temperature dell’aria che in media dovevano essere più basse di circa 10°c. la circolazione atmosferica era notevolmente più intensa, con prolungati fenomeni di perturbazione che si protraevano persino nella stagione estiva. principalmente a causa delle ridotte precipitazioni, erano estremamente comuni piante erbacee ed arbustive relativamente basse come l’artemisia o quelle della famiglia delle chenopodiaceae, indicative di un ambiente aperto di steppa o semi-steppa. tuttavia, alcune specie vegetali mesofile e termofile di alberi della sottodivisione angiosperme, sebbene in quantità molto limitate, sembrano essere sopravvissute in questo ambiente così ostile. la presenza di piccole aree forestali, probabilmente localizzate ad alta quota, è testimoniato anche dal ritrovamento di resti di cervidi nell’associazione faunistica castello. non ci sono evidenze che il passaggio tra ultimo periodo glaciale e olocene sia avvenuto attraverso due brusche fluttuazioni climatiche chiamate bølling-allerød (fluttuazione calda) e younger dryas (fluttuazione fredda). poiché però queste variazioni sono chiaramente registrate nei sedimenti marini recuperati nei pressi della costa siciliana, è possibile che questo difetto sia dovuto solamente a problemi del record sedimentario continentale. ulteriori studi sono necessari per chiarire l’evoluzione dell’ambiente durante il periodo della deglaciazione. fenomeni di instabil ità climatica durante l’olocene hanno interessato anche quest’area del mediterraneo e sarebbero caratterizzati da temperature più basse delle acque superficiali e dall’azione prolungata e più intensa dei venti provenienti dai quadranti settentrionali. anche in questo caso non è però chiaro quale sia stato l’impatto di queste variazioni climatiche ad alta frequenza sull’ambiente continentale. per quanto riguarda la vegetazione, una copertura forestale si sviluppò gradualmente e raggiunse il suo culmine a circa 10 ka cal bp nelle regioni interne e montane dell’isola. queste foreste andarono sempre più diradandosi seguendo il generale trend di aridificazione e diminuzione delle precipitazioni. indicazioni contrastanti arrivano però dalle regioni costiere, dove dopo l’iniziale espansione di arbusti e cespugli tipici della macchia mediterranea, una vera foresta di alberi sempreverdi si espanse a partire da 7 ka cal bp. i dati della vegetazione tra regioni interne e costiere sono invece concordi nell’indicare il forte impatto antropico dovuto all’uso del territorio a fini agricoli e di allevamento, avvenuto a partire da 2,7 ka cal bp, al tempo dell’insedimento delle prime colonie greche. senza l’intervento dell’uomo, l’aspetto della vegetazione nell’isola sarebbe molto diverso ed ancora sostanzialmente caratterizzato dalla presenza di boschi e foreste. la nostra considerazione finale è che ancora molto rimane da chiarire circa l’interazione tra clima ed ambiente in sicilia. malgrado alcuni studi condotti sul record continentale siano caratterizzati da continuità deposizionale e adeguata risoluzione stratigrafica, una 31ambiente e clima della sicilia ... serie di interessanti informazioni restano ancora confinate nei sedimenti marini che circondano l’isola. in questo senso, è auspicabile che le ricerche che verranno intraprese abbiano un carattere fortemente multidisciplinare, prendendo in considerazione al contempo aspetti dell’ambiente marino e dell’ambiente continentale. ringraziamenti ringraziamo due anonimi revisori per gli utili commenti e suggerimenti. si ringraziano inoltre i colleghi che hanno messo a disposizione i propri risultati, direttamente o attraverso banche dati sul web. questo studio è stato finanziato attraverso fondi ateneo ex 60%, e. di stefano, p. di stefano e a. greco. riferimenti bibliografici agnesi v., macaluso t. & masini f. (1997) l’ambiente e il clima della sicilia nell’ultimo milione di anni. in: prima sicilia alle origini della società siciliana. ed. s. tusa, ediprint, 111-133. allen j.r.m. & huntley b. (2009) last interglacial palaeovegetation, palaeoenvironments and chronology : a new record from lago grande di monticchio, southern italy. quaternary science reviews 28, 1521-1538. allen j.r.m., brandt u., brauer a., hubberten h.-w., huntley b., keller j., kraml m., mackensen a., mingram j., negendank j.f.w., nowaczyk n.r., oberhänsli h., watts w.a., wulf s. & zolitschka b. (1999) rapid environmental changes in southern europe during the last glacial period. nature 400, 740-743. alley r.b., mayewski p.a., sowers t., stuiver m., taylor k.c. & clark, p.u. (1997) holocene climatic instability: a prominent widespread event 8200 years ago. geology 25, 483-486. antonioli f., ferranti l., lambeck k., kershaw s., verrubbi v. & dai pra g. (2006b) late pleistocene to holocene record of changing uplift rates in southern calabria and eastern sicily (southern italy, central mediterranean sea). tectonophysics 422, 23-40. antonioli f., kershaw s., renda p., rust d., belluomini g., cerasoli m., radtke u. & silenzi s. (2006a) elevation of the last interglacial highstand in sicily (italy): a benchmark of coastal tectonics . quaternary international 145-146, 3-18. barron, e. & pollard, d. (2002) high-resolution climate simulations of oxygen isotope stage 3 in europe. quaternary research 58, 296-309. bond g., heinrich h., broecker w.s., labeyrie l., mcmanus j., andrews j., huon s., jantschik r., clasen s., simet c., tedesco k., klas m., bonani g. & ivy s. (1992) evidence for massive discharges of icebergs into the north atlantic during the last glacial period. nature 360, 245-249. bond g., kromer b., beer j., muscheler r., evans m., showers w., hoffmann s., lotti-bond r., hajdas i. & bonani g. (2001) persistent solar influence on north atlantic climate during the holocene. science 294, 2130-2136. bond g., showers w., cheseby m., lotti r., almasi p., demenocal p., priore p., cullen h., hajdas i. & bonani g. (1997) a pervasive millennial-scale cycle in north atlantic holocene and glacial climates. science 278, 1257-1266. bonfiglio l., marra a.c. & masini f. (2000) the contribution of quaternary vertebrates to the paleoenvironmental and paleoclimatological reconstructions in sicily. in hart, m.b. (ed.) climates: past and present. geological society of london, special publications 181, 171-184. bradley r.s. (2008) holocene perspectives on future climate change. in battarbee, r.w. and binney, h.a. (eds.) natural climate variability and global warming: a holocene perspective. john wiley and sons, ltd., publication, 254-268. brauer a., allen j.r.m., mingram j., dulski p., wulf s. & huntley b. (2007) evidence for last interglacial chronology and environmental change from southern europe. proceedings of the national academy of sciences of the united states of america 104, 450-455. broecker w.s. (1998) paleocean circulation during the last deglaciation: a bipolar seesaw?. paleoceanography 13, 119-121. broecker w., bond g., klas m., bonani g. & wolfli g. (1990) a salt oscillator in the glacial atlantic? 1. the concept. paleoceanography 5, 469-477. buccheri g., capretto g., di donato v., esposito p., ferruzza g., pescatore t., russo ermolli e., senatore m.r., sprovieri m., bertoldo m., carella d. & madonia g. (2002) a high resolution record of the last deglaciation in the southern tyrrhenian sea: environmental and climatic evolution. marine geology 186, 447–470. cacho i., grimalt j.o. & canals m. (2002) response of the western mediterranean sea to rapid climatic variability during the last 50,000 years: a molecular biomarker approach. journal of marine systems 33, 253-272. cacho i., grimalt j.o., canals m., sbaffi l., shackleton n.j., schönfeld j. & zahn r. (2001) variability of the western mediterranean sea surface temperatures during the last 25,000 years and its connection with the northern hemisphere climatic changes. paleoceanography 16, 40-52. cacho i., grimalt j.o., pelejero c., canals m., sierro f.j., flores j.a. & shackleton n. (1999) dansgaard-oeschger and heinrich event imprints in alboran sea paleotemperatures. paleoceanography 14, 698-705. cacho i., grimalt j.o., sierro f.j., shackleton n. & canals m. (2000) evidence for enhanced mediterranean thermohaline circulation during rapid climatic coolings. earth and planetary science letters 183, 417-429. cavalli-sforza l. & cavalli-sforza f. (1993) chi siamo. la storia della diversità umana. mondadori editore, milano, 1-405. chilardi s., frayer d.w., gioia p., macchiarelli r. & mussi m. (1996) fontana nuova di ragusa (sicily, italy): sothernmost aurignacian site in europe. antiquity 70, 553-563. combourieu-nebout n., paterne m., turon j.-l. & siani 32 a. incarbona et al. g. (1998) a high-resolution record of the last deglaciation in the central mediterranean sea: palaeovegetation and palaeohydrological evolution. quaternary science reviews 17, 303-317. combourieu nebout n., turon j.l., zahn r., capotondi l., londeix l. & pahnke k. (2002) enhanced aridity and atmospheric high-pressure stability over the western mediterranean during the north atlantic cold events of the past 50 k.y. geology 30, 863-866. d’amore g., di marco s., tartarelli g., bigazzi r. & sineo l. (2009) late pleistocene human evolution in sicily: comparative morphometric analysis of grotta di san teodoro craniofacial remains. journal of human evolution, doi:10.1016/j.jhevol.2009.02.002. dansgaard, w., johnsen, s.j., clausen, h.b., dahljensen, d., gundestrup, n.s., hammer, c.u., hvidberg, c.s., steffensen, j.p., sveinbjörnsdottir, a.e., jouzel, j. & bond, g. (1993) evidence for general instability of past climate from a 250-ka cal ice-core record. nature 364, 218-220. de guidi g., catalano s., monaco c. & tortorici l. (2003) morphological evidence of holocene coseismic deformation in the taormina region (ne sicily). journal of geodynamics 36, 193-211. denton g.h. & karlén w. (1973) holocene climatic variations: their pattern and possibile cause. quaternary research 3, 155-205. di stefano a. & branca s. (2002) long-term uplift rate of the etna volcano basement (southern italy) based on biochronological data from pleistocene sediments. terra nova 14, 61-68. di stefano e. & incarbona a. (2004) high resolution paleoenvironmental reconstruction of the odp963d hole (sicily channel) during the last deglaciation, based on calcareous nannofossils. marine micropaleontology 52, 241-254. ferranti l., monaco c., antonioli f., maschio l., kershaw s. & verrubbi v. (2007) the contribution of regional uplift and coseismic slip to the vertical crustal motion in the messina straits, southern italy: evidence from raised late holocene shorelines. journal of geophysical research 112, bo6401, doi:10.1029/2006jb004473. ferranti l., monaco c., morelli, d., antonioli f. & maschio l. (2008) holocene activity of the scilla fault, southern calabria: insights from coastal morpho-structural investigations. tectonophysics 453, 74-93. frigola j., moreno a., cacho i., canals m., sierro f.j., flores j.a. & grimalt, j.o. (2008) evidence of abrupt changes in western mediterranean deep water circulation during the last 50 ka cal: a highresolution marine record from the balearic sea. quaternary international 181, 88-104. frisia s., borsato a., mangini a., spötl c., madonia g. & sauro u. (2006) holocene climate variability in sicily from a discontinuous stalagmite record and the mesolithic to neolithic transition. quaternary international 66, 388-400. gaetani m., baldi m., dalu g.a. & maracchi g. (2007) connessioni tra il clima della regione mediterranean e l’africa occidentale attraverso la circolazione meridiana di hadley. in: carli, b., cavarretta, g., colacino, m., fuzzi, s., (eds.), clima e cambiamenti climatici: le attività di ricerca del cnr, 23-26. gasse f. (2000) hydrological changes in the african tropics since the last glacial maximum. quaternary science reviews 19, 189-211. graziosi p. (1947) gli uomini paleolitici della grotta di s. teodoro. rivista di scienze preistoriche 3, 123223. hayes a., kucera, m., kallel n., sbaffi l. & rohling e.j., (2005) glacial mediterranean sea surface temperatures based on planktonic foraminiferal assemblages. quaternary science reviews 24, 999-1016. holzhauser h., magny m. & zumbuhl h.j. (2005) glacier and lake-level variations in west-central europe over the last 3500 years. the holocene 15, 789–801. incarbona a., bonomo s., di stefano e., zgozi s., essarbout n., talha m., tranchida g., bonanno a., patti b., placenti f., buscaino g., cuttitta a., basilone g., bahri t., massa f., censi p. & mazzola s. (2008c) calcareous nannofossil surface sediment assemblages from the sicily channel (central mediterranean sea): palaeoceanographic implications. marine micropaleontology 67, 297-309. incarbona a., di stefano e., patti b., pelosi n., bonomo s., mazzola s., sprovieri r., tranchida g., zgozi s. & bonanno a. (2008a) holocene millennialscale productivity variations in the sicily channel (mediterranean sea). paleoceanography 23, pa3204, doi:10.1029/2007pa001581, 1-18. incarbona a., di stefano e., sprovieri r., bonomo s., censi p., dinarès-turell j. & spoto s. (2008b) vertical structure variability of the water column and paleoproductivity reconstruction in the central-western mediterranean during the late pleistocene. marine micropaleontology 69, 26-41. kuhlemann j., rohling e.j., krumrei i., kubik, p., ivyochs s. & kucera m. (2008) regional synthesis of mediterranean atmospheric circulation during the last glacial maximum. science 321, 13381340. lea d.w., martin p.a., pak d.k. & spero h.j. (2002) reconstructing a 350 ky history of sea level using planktonic mg/ca and oxygen isotope records from a cocos ridge core. quaternary science reviews 21, 283-293. magri d. & parra i. (2002) late quaternary western mediterranean pollen records and african winds. earth and planetary science letters 200, 401408. martin p.a., lea d.w., rosenthal y., shackleton n.j., sarnthein m. & papenfuss t. (2002) quaternary deep sea temperature histories derived from benthic foraminiferal mg/ca. earth and planetary science letters 198, 193-209. masini f., petruso d., bonfiglio l. & mangano g. (2008) origination and extinction patterns of mammals in three central western mediterranean islands from the late miocene to quaternary. quaternary international 182, 63-79. mayewski p.a., meeker l.d., twickler m.s., whitlow s., 33ambiente e clima della sicilia ... yang q., lyons w.b. & prentice m. (1997) major features and forcing of high-latitude northern hemisphere atmospheric circulation using a 110,000-year long glaciochemical series. journal of geophysical research 102, 26345-26366. mayewski p.a., rohling e.j., stager j.c., karlén w., maasch k.a., meeker l.d., meyerson e.a., gasse f., van kreveld s., holmgren k., lee-thorp j., rosqvist g., rack f., straubwasser m., schneider r.r. & steig, e.j. (2004) holocene climate variability. quaternary research 62, 243-255. meeker l.d. & mayewski p.a. (2002) a 1400-year highresolution record of atmospheric circulation over the north atlantic and asia. holocene 12, 257266. de menocal p., ortiz j., guilderson t., adkins j., sarnthein m., baker l. & yarusinsky m. (2000) abrupt onset and termination of the african humid period: rapid climate responses to gradual insolation forcing. quaternary science reviews 19, 347361. millot c. (1999) circulation in the western mediterranean sea. journal of marine systems 20, 423-442. montenat c. & barrier p. (1987) approche quantitative des mouvements verticaux quaternaires dans le détroit de messine. doc. et trav. igal 11, 185190. moreno a., cacho i., canals m., grimalt j.o. (2004) millennial-scale variability in the productivity signal from the alboran sea record. palaeogeography palaeoclimatology palaeoecology 211, 205-219. moreno a., cacho i., canals m., prins m.a., sánchezgoñi m.-f. grimalt, j.o. & weltje g.j. (2002) saharan dust transport and high-latitude glacial climatic variability: the alboran sea record. quaternary research 58, 318-328. north greenland ice core project members (2004) high-resolution record of northern hemisphere climate extending into the last interglacial period. nature 431, 148-151. noti r., van leeuwen j.f.n., colombaroli d., vescovi e., pasta s., la mantia t. & tinner w. (2009) midand late-holocene vegetation and fire history at biviere di gela, a coastal lake in southern sicily, italy. vegetation history and archaeobotany, springer, heidelberg, germany. o’brien s.r., mayewski p.a., meeker l.d., meese d.a., twickler m.s. & whitlow s.i. (1995) complexity of holocene climate as reconstructed from a greenland ice core. science 270, 1962-1964. pérez-folgado m., sierro f.j., flores j.-a., cacho i., grimalt j.o. & zahn r. (2003) western mediterranean planktonic foraminifera events and climatic variability during the last 70 ka cal. marine micropaleontology 48, 49-70. petit j.r., jouzel j., raynaud d., barkov n.i., barnola j.-m., basile i., bender m., chappellaz j., davis m., delaygue g., delmotte m., kotlyakov v.m., legrand m., lipenkov v.y., lorius c., pepin l., ritz c., saltzman e. & stievenard m. (1999) climate and atmospheric history of the past 420,000 years from the vostok ice core, antarctica. nature 399, 429-436. petruso d., sarà m., surdi g. & masini f. (in stampa) le faune a mammiferi della sicil ia tra i l tardoglaciale e l’olocene. biogeographia. piervitali e. & colacino m. (2001) evidence of drought in western sicily during the period 1565-1915 from liturgical offices. climatic change 49, 225238. piperno m. (1997) il popolamento della sicilia il paleolitico inferiore. in: prima sicilia alle origini della società siciliana, ediprint, palermo, 83-92. poem group (1992) general circulation of the eastern mediterranean. earth-science reviews 32, 285309. rohling e.j., hayes a., de rijk s., kroon d., zachariasse w.j. & eisma d. (1998) abrupt cold spells in the northwest mediterranean. paleoceanography 13, 316-322. rohling e.j., mayewsky, p.a., abu-zied r.h., casford j.s.l. & hayes a. (2002) holocene atmosphereocean interaction: records from greenland and the aegean sea. climate dynamics 18, 587-593. rohling e.j., mayewsky p.a. & challenor p. (2003) on the timing and mechanism of millennial-scale climate variability during the last glacial cycle. climate dynamics 20, 257-267. roucoux k.h., de abreu l., shackleton n.j. & tzedakis p.c. (2005) the response of nw iberian vegetation to north atlantic climate oscillations during the last 65 ka cal. quaternary science reviews 24, 1637-1653. sadori l. & giardini m. (2007) charcoal analysis, a method to study vegetation and climate of the holocene: the case of lago pergusa (sicily, italy). geobios 40, 173-180. sadori l. & narcisi b. (2001) the post-glacial record of environmental history from lago di pergusa (sicily). the holocene 11, 655-671. sadori l., zanchetta g. & giardini m. (2008) last glacial to holocene palaeoenvironmental evolution at lago di pergusa (sicily), as inferred from pollen, microcharcoal, and stable isotopes. quaternary international 181, 4-14. sanchez goñi, m.f., eynaud, f., turon, j.l., shackleton, n.j. (1999) high resolution palynological record off the iberian margin: direct landsea correlation for the last interglacial complex. earth and planetary science letters 171, 123137. sarà m. (1998) i mammiferi delle isole del mediterraneo. l'epos, palermo, 1-146. sauro u., borsato a., frisia s., madonia g., piccini l., tuccimei p., camuffo d., cucchi f., forti p., macaluso t., miorandi r., panadini m., salzano r., shopov y., spötl c., stoykova d. & zini l. (2005) variabilità climatica nel tardiglaciale e nell’olocene da dati di speleotemi lungo una traversa n-s in italia. studi trentini di scienze naturali, acta geologica 80, 175-184. sbaffi l., wezel f.c., curzi g. & zoppi u. (2004) millennialto centennial-scale palaeoclimatic variations during termination i and the holocene in the central mediterranean sea. global and planetary change 40, 201-217. sbaffi l., wezel f.c., kallel n., paterne m., cacho i., ziveri p. & shackleton n. (2001) response of the pelagic environment to palaeoclimatic chan34 a. incarbona et al. ges in the central mediterranean sea during the late quaternary. marine geology 178, 39-62. segre a. & vigliardi a. (1983) l’epigravettien évolué et final en sicile. rivista di scienze preistoriche 37, 351-369. sierro f.j., hodell d.a., curtis j.h., flores j.-a., reguera i., colmenero-hidalgo e., bárcena m.a., grimalt j.o., cacho i., frigola j. & canals m. (2005) impact of iceberg melting on mediterranean thermohaline circulation during heinrich events . paleoceanography 20 , doi:10.1029/2004pa001051. silenzi s., antonioli f. & chemello r. (2004) a new marker for sea surface temperature trend during the last centuries in temperate areas: vermetid reef. global and planetary change 40, 105-114. sineo l., bigazzi r., d'amore g., tartarelli g., di patti c., berzero a., caramella & crespi v. (2002) i resti umani della grotta di s. teodoro (messina): datazione assoluta con il metodo della spettrometria gamma diretta (u/pa). antropo 2, 9-16. skinner l.c. & shackleton n.j. (2005) an atlantic lead over pacific deep-water change across termination i: implications for the application of the marine isotope stage stratigraphy. quaternary science reviews 24, 571-580. skinner l.c., shackleton n.j. & elderfield h. (2003) millennial-scale variability of deep-water temperature and δ18odw indicating deep-water source variations in the northeast atlantic, 0-34 ka bp. geochemistry, geophysics, geosystems 4, 1-17. sprovieri m., pelosi n., sprovieri r., incarbona a. & ribera d’alcalà m. (2007) l’evoluzione del clima nell’area mediterranea durante l’intervallo 20.00070.000 anni. in: carli, b., cavarretta, g., colacino, m., fuzzi, s., (eds.), clima e cambiamenti climatici: le attività di ricerca del cnr, 177-180. sprovieri r., di stefano e., incarbona a. & gargano m.e. (2003) a high-resolution record of the last deglaciation in the sicily channel based on foraminifera and calcareous nannofossil quantitative distribution. palaeogeography palaeoclimatology palaeoecology 202, 119-142. sprovieri r., di stefano e., incarbona a. & oppo, d.w. (2006) suborbital climate variability during marine isotopic stage 5 in the central mediterranean basin: evidence from calcareous plankton. quaternary science reviews 25, 23322342. tinner w., van leeuwen j.f.n., colombaroli d., vescovi e., van der knaap w.o., henne p.d., pasta s., d’angelo s. & la mantia t. (2009) holocene environmental and climatic changes at gorgo basso, a coastal lake in southern sicily, italy. quaternary science reviews 28, 1498-1510. tzedakis p.c., mcmanus j.f., hooghiemstra h., oppo d.w. & wijmstra t.a. (2003) comparison of changes in vegetation in northeast greece with records of climate variability on orbital and suborbital frequencies over the last 450 000 years. earth and planetary science letters 212, 197212. vigliardi a. (1968) l’industria litica della grotta di s. teodoro, in provincia di messina. rivista di scienze preistoriche 23, 33-144. vigliardi a. (1997) l’arte rupestre e mobiliare dal paleolitico all’eneolitico. in: prima sicilia alle origini della società siciliana, ediprint, palermo, 83-92. walker m., johnsen s. rasmussen s.o., steffensen j.p., popp t., gibbard p., hoek w.z., lowe j., andrews j., björck s., cwynar l., hughen k., kershaw p., kromer b., litt t., lowe d.j., nakagawa t., newnham r. & schwander j. (2008) the global stratotype section and point (gssp) for the base of the holocene series/epoch (quaternary system/period) in the ngrip ice core. episodes 31, 264-267. wanner, h., beer, j., bütikofer, j., crowley, t.j., cubasch, u., flückiger, j., goosse, h., grosjean, m., joos, f., kaplan, j.o., küttel, m., müller, s.a., prentice, i.c., solomina, o., stocker, t.f., tarasov, p., wagner, m., widmann, m. (2008) midto late holocene climate change: an overview. quaternary science reviews 27, 1791-1828. zanchetta g., borghini a., fallick a.e., bonadonna f.p. & leone g. (2006) late quaternary palaeohydrology of lake pergusa (sicily, southern italy) as inferred by stable isotopes of lacustrine carbonates. journal of paleolimnology, doi:10.1007/ s10933-006-9070-1. zonneveld k.a.f. (1996) palaeoclimatic and palaeoecologic changes in the eastern mediterranean and arabian sea regions during the last deglaciation: a palynological approach to land–sea correlation. lpp contribution series 3, ponsen and looijen, wageningen, 1-200. 35 ms. ricevuto il 27 maggio 2009 testo definitivo ricevuto il 29 settembre 2009 ms. received: may 27, 2009 final text received: september 29, 2009 ambiente e clima della sicilia ... amq 31(1) 49-57 riga et al proofcopy available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 31 (1), 2018, 49 57 at the upper palaeolithic mesolithic boundary: revision of the human remains from riparo fredian (molazzana, lucca, italy) alessandro riga1,2, irene dori1,3, stéphanie vierin1, giovanni boschian4, carlo tozzi5, john c. willman6,7, jacopo moggi-cecchi1-8 1 department of biology, university of florence, firenze, italy 2 laboratory of archaeoanthropology, sabap-fi, scandicci (fi), italy 3 univ. bordeaux, cnrs, mc, pacea, pessac, france 4 department of biology, university of pisa, pisa, italy 5 department of civilisations and forms of knowledge, university of pisa, pisa, italy 6 institut català de paleoecologia humana i evolució social (iphes), tarragona, spain 7 àrea de prehistòria, universitat rovira i virgili (urv), tarragona, spain 8 centre for anthropological research, university of johannesburg, auckland park, johannesburg, south africa corresponding author: j. moggi-cecchi <iacopo.moggicecchi@unifi.it> abstract: pleistocene and early holocene human fossils in tuscany are very few and poorly described. any new information is thus an important contribution to our knowledge of the peopling of this region. here we present a revision of the human fossil remains from the riparo fredian, a site located in garfagnana and first published by boschian et al., (1995). the authors described the human remains of the site pointing out the presence of 39 isolated human teeth (19 maxillary and 20 mandibular) and “fragments of one adult humerus, of a child's femur and of a youngster’s ulna”, considered as belonging to six individuals at least. a reanalysis of the human remains indicated that several specimens were incorrectly identified. it was thus deemed important to revise the identification of each fossil and their interpretation. the revision of human remains from riparo fredian has led to several changes in their anatomical identification with respect to the original publications. of the 39 teeth previously described, the analysis revealed that two of them belonged to non-human animals, and 18 were mistakenly identified. a new, correct identification is provided for each of them. also, two human teeth not described in the original papers have been identified. the anatomical identification of the post-cranial remains has been confirmed for two out of the three specimens. the minimum number of individuals, based on the dental remains, is confirmed as at least 5, but most probably 6, although with a different allocation of teeth to individual specimens. the age at death of the six individuals has also been reassessed, indicating the presence of two infants, two young adults and two mature adults. keywords: riparo fredian, epipalaeolithic, late upper palaeolithic 1. introduction in central italy, the human fossil record from pleistocene sites in tuscany is very scanty, and it is limited to a few remains from three sites: buca del tasso, vado all’arancio and riparo fredian (alciati et al., 2005). thus, any new information on the fossils deriving from these sites is an important contribution to our knowledge of the peopling of this region. here we present a revision of the human fossil remains from the riparo fredian site, first published by boschian et al. (1995). riparo fredian (molazzana, lucca, italy) is a site located in garfagnana, a geographic region in northern tuscany delimited by the apuan alps on the west and the appenines on the east. the serchio is the main river of the valley and among its right tributaries is the turrite secca creek, which rises on the apuan alps. riparo fredian is a rock shelter on the turrite secca (fig. 1). among the numerous late upper palaeolithic (lup) and mesolithic sites of the valley, it is the only one with human remains. it is considered a low-altitude camp of the palaeolithic and mesolithic hunter-gatherers who occupied the turrite secca valley when the climatic condition allowed for it (see below). in a paper dedicated to the site, boschian et al. (1995), alongside the geology, stratigraphy and lithic industries, described the human remains of the site pointing out the presence of 39 isolated human teeth (19 maxillary and 20 mandibular teeth) and “fragments of one adult humerus, of a child's femur and of a youngster’s ulna” (p.66), which were described as belonging to six individuals at least. an initial reanalysis of the human remains (vierin, 2013), indicated that several specimens were incorrectly identified; also, a recent paper (oxilia et al., 2017) described the evidence for dental treatment in one of the specimens (individual 5) from the site. on this background, it was deemed important to revise the identification of each fossil and their interpretation, also in the light of the limited number of human fossils recovered from this time frame in tuscany. the results of this https://doi.org/10.26382/amq.2018.04 50 riga a. et al. revision are presented below, together with illustrations of each specimen, not present in the original publications. 1.1 the peopling of the serchio and turrite secca valleys the upper and middle serchio and the turrite secca valleys have been subject of intense archaeological surveys since from the 1970s, which have led to the discovery of numerous prehistoric settlements, attributed mainly to late upper palaeolithic (lup), mesolithic and metal ages (notini, 1973; castelletti & cremaschi, 1975; tozzi, 1980; biagi et al., 1981; notini, 1983; guidi & rossi, 1984; guidi et al., 1985; boschian et al., 1995). the first evidence of human presence in this area are a few surface findings of levallois tools suggesting a sporadic occupation during the middle palaeolithic, and a single tool doubtfully assigned to an early phase of upper palaeolithic (notini, 1973). during the last pleniglacial, climatic conditions prevented human presence in the area, due to the expansion of the glaciers on the apuan alps and apennines, which reached very low altitudes down the valleys (castelletti et al., 1994; boschian et al., 1995). in the turrite secca valley, the glacier of mount altissimo had his frontal moraine at campagrina, a few kilometres from riparo fredian (masini, 1949; boschian et al., 1995); long ice tongues descended in the valley from mount corchia, pania della croce and pania secca, reaching 600-700 m a.s.l., less than 2 km far from riparo fredian (braschi et al., 1986). as the glaciers receded and the climate became warmer, the human frequentation of the upper and middle serchio and the turrite secca valleys becomes regular. starting from allerod/dryas iii transition, the first sites attributable to the final epigravettian (lup) appeared, with a majority of them located at low altitudes, and a few sites mostly temporary camps at higher altitudes (castelletti et al., 1994). this trend continued with the mesolithic cultures of sauveterrian and castelnovian expanding their presence to higher altitudes (castelletti et al., 1994). during the neolithic, the human population in the valleys drastically drops to rise again in the copper age and bronze age, when this area becomes permanently occupied and new settlements appeared (castelletti et al., 1994). 1.2. riparo fredian riparo fredian is a rock shelter on the right bank of the turrite secca, situated on a terrace 2-3 m above the river, at 360 m a.s.l.. excavations were carried out from 1987 to 1990, and their results were published in a detailed paper (boschian et al., 1995). here, we summarize the most significant information on the stratigraphic and archaeological context, focusing on the anthropological findings. the sequence of the deposit (about 1.60 m) is subdivided into 8 lithologic units (fig. 2). units from 8 to 5b do not document any anthropic activity; units 5a, 4 and 3 document human presence in the lup and the mesolithic; at the end of the sequence, unit 2 and unit 1 are composed of several thin layers with pottery remains (boschian et al., 1995). the archaeological record suggests that the site was intensively frequented during the deposition of layer 5: its assemblage, attributed to final epigravettian, is the richest of the site, with 90 cores, more than 900 tools, about 3000 lithic artefacts without retouch, and more than 8000 fragments and debris. in addition, this layer returned seven perforated shells (columbella sp.), 144 pieces of ochre, four artefacts partially dyed with ochre, and three bone artefacts. conversely, human presence at the site during the following phases (deposition of layers 4 and 3) is sporadic: lithic assemblages are far less rich and there are no bone artefacts. the scarcity of remains in layers 4 and 3 compared to layer 5 makes it more difficult to assign a typological attribution to the lithic assemblage. nevertheless, the layer 5 assemblage can be reasonably attributed to the sauveterrian facies of the mesolithic industry (boschian et al., 1995). faunal remains indicate a more intense human presence during the final epigravettian. they are most abundant in layer 5, strongly diminish in layer 4 and are rare in layer 3. mostly they are represented by ibex (capra ibex) and red deer (cervus elaphus), but wild fig. 1 a) position of the riparo fredian site in northern tuscany (italy). b) position of riparo fredian relative to the apuan alps and the appenines. 51 human remains from riparo fredian boar (sus scrofa), auroch (bos primigenius), and roe deer (capreolus capreolus) are present as well. carnivores remains attributable to the families of ursidae (ursus arctos), canidae, mustelidae and felidae are present (boschian et al., 1995; cilli et al., 1998). ams radiocarbon dates from charcoal samples confirm this attribution. layer 4 (sample aa10951) dates to 9,458±91 bp (11,106-10,500 cal bp for ±2σ calibrated range), and layer 5 (sample aa10952) to 10,870± 119 bp (13,040-12,600 cal bp for ±2σ calibrated range) (boschian et al., 1995). the limit between layer 5 (late epigravettian) and 4 (sauveterrian) is partially marked by a stone pavement of large rounded cobbles, whose origin is certainly anthropic (boschian et al., 1995). this pavement extended in the inner part of the shelter, on an area of about 2 m2, and on its external margin there is the residue of a fire. numerous human teeth and the remains of badly preserved human post-cranial bones have been found among the interstices of the pavement. the meaning of the cobble pavement is not fully understood: it is possible that it represented a raised platform to drain water, but the presence of numerous human remains above and below the pavement suggests that other explanations possibly linked to particular human behaviours or symbolic intentions are plausible. some of the human remains come from the lower part of layer 4, whereas others come from the top of the layer 5. boschian et al. (1995) suggested that teeth found in layer 5 might be infiltrated between the large pebbles from layer 4, whereas oxilia et al. (2017) suggested a different process to explain the stratigraphic position of the remains. according to this hypothesis, layer 4 largely derives from erosion and redeposition of layer 5 and most probably the teeth found in layer 4 were originally embedded in layer 5 (oxilia et al., 2017). a recent direct ams radiocarbon dating on the upper right canine of fredian 5 (tooth label 133) confirmed the epigravettian origin of teeth embedded in layer 5, suggesting a 14c age of 11,000±40 bp, with a ±2σ calibrated range between 13,000-12,740 cal bp (oxilia et al., 2017). fig. 2 map (a) and sections (b and c) of riparo fredian (from boschian et al., 1995). 2. first anthropological analysis the human remains found at riparo fredian were initially described by boschian et al. (1995); another description of these findings, based on the previous paper, is reported in mallegni (2005). in these works, the authors reported and analysed the skeletal remains found between the upper part of layer 5 and the lower part of layer 4. the human teeth represent the most abundant part of these findings, whereas only a few post-cranial bones have been found. 2.1. dental remains boschian et al. (1995) recognized 39 isolated teeth, 19 maxillary and 20 mandibular. based on the characteristics of the dental type, dental class, and wear stage, boschian et al. (1995) suggested the occurrence of at least 5-6 individuals (most likely 6) of different age classes. both deciduous and permanent teeth are present at riparo fredian and the authors identified two children (one of 12-18 months and one of 18-24 months), one adolescent (about 15 years old), and three adults (one of them described as mature adult). the original analysis also included observations on the occurrence of dental enamel hypoplasia: two of six individuals (33% of the sample) presented the defect, although of moderate grade of expression (boschian et al., 1995; mallegni, 2005). for one individual (n. 6), the authors calculated the age of the occurrence of the defects, between 3 and 6 (boschian et al., 1995, p. 73). 2.2. post-cranial remains the post-cranial remains are represented by the diaphysis (the distal third) of an adult left humerus, an incomplete left infant femur, and a fragment of a right ulna attributed to an adolescent. the authors posited that the few post-cranial elements belong to the individuals identified by the dental analysis (boschian et al., 1995). on the surfaces of the humerus and ulna, the authors described the presence of marks (respectively chipping and indentations) covered by sediments interpreted as proving their antiquity, obtained probably on fresh bones and the result of as intentional human manipulation (boschian et al., 1995; mallegni, 2005). boschian et al. (1995) concluded that the skeletal remains found at riparo fredian were not in anatomical connection; were probably not associated with burials and were deriving from a site with limited extension. on the base of these considerations, they proposed that the occurrence of the remains was the result of some kind of cultural tradition where only selected parts of a skeleton were preserved. 3. revision of the anthropological remains on the occasion of a recent revision (vierin, 2013), all the anthropological remains have been reanalysed in order to check the specific attribution, the correct identification and the measurements. no significant differences were found in the metrical data (dental dimensions), whereas several discrepancies in the identification of dental remains and post-cranial bones have been revealed. these are described below. 3.1. dental remains the results of the revision of dental remains are listed in table 1. of the 39 teeth described in boschian et al. (1995) two of them (labels 10 and 205) turned out to be nonhuman fauna; however, the total number of human teeth is still 39, because two teeth (labelled 19 and 20) that were not considered in the previous study have now been recognised and included here. below a list of the teeth whose identification has been revised is presented, together with the features indicative of the new identification. tooth n. 21 uli2. originally identified as a lp(?). this tooth is very worn and the crown is completely absent. the section of the root is relatively rounded and small in size when compared to canines (133 and 161) and central incisors (31 and 134) of the same individual (fredian 5); comparison of root lengths with the teeth mentioned above indicates that this is an upper incisor. siding is based on wear association between adjacent teeth (see also oxilia et al., 2017). tooth n. 31 uri1. originally identified as a lp(?). it is a very worn central incisor with no crown preserved. it is identifiable by the stout and obovate section of the root; siding is based on wear association between adjacent teeth (see also oxilia et al., 2017). tooth n. 4 lrm3. originally identified as lrm2. the absence of the distal contact facet suggests this is an m3; also, its occlusal morphology matches with tooth n. 13, an urm3. tooth n. 42 lldi2. originally identified as lrdi2 but the mesial margin, higher than the distal one, indicates it is a left. tooth n. 5 uri2. originally identified as a lp(?). the same line of reasoning as for tooth n. 21, suggests the new identification as a uri2 (see also oxilia et al., 2017). tooth n. 7 lrp2. originally identified as a llp2; the mesial marginal ridge, higher than the distal marginal ridge, helps siding it as a right premolar. tooth n. 8 urdm1. originally identified as an uldm1; the presence of a pronounced tubercle on the buccal surface of the mesio-buccal cusp clearly sides the tooth as right. tooth n. 9 urp2. originally identified as an ulp1; the absence of the developmental groove and the mesially placed lingual cusp suggests it is a urp2. tooth n. 121 llp2. originally identified as a lrp2; the mesial marginal ridge, higher than the distal marginal ridge, helps siding it as a left premolar. tooth n. 133 urc. originally identified as a lrp2(?). root length and morphology suggest it is an upper canine (see also oxilia et al., 2017). tooth n. 134 uli1. originally identified as lp or li (?). the same line of reasoning as for tooth n. 31, suggests the new identification as a uli1 (see also oxilia et al., 2017). tooth n. 16 llm3. originally identified as a lrm3. the expression of protostylid as a groove on the buccal 52 riga a. et al. 53 tab. 1 new identification and individual attribution of the dental remains from riparo fredian. * found in the reddish soil between the cobbles. (1) wear stage calculated on the basis of smith (1984). human remains from riparo fredian surface of cusp 1 clearly indicates it is a left molar. tooth n. 161 ulc. originally identified as a llp2. root length and morphology suggest it is an upper canine (see also oxilia et al., 2017). tooth n. 162 ulp2. originally identified as an urp1; the absence of the developmental groove on the mesial side, and the mesially placed apex of the lingual cusp suggest it is an ulp2. tooth n. 17 lli2. originally identified as a lri2. the relative position of the mesial and distal contact facets suggests it is a left incisor. tooth n. 201 urm1. originally identified as an ulm2; all the four cusps are well defined, thus the tooth is most probably an m1. also, the position of the cusps and the occlusal wear indicate it is right. tooth n. 202 lrc. originally identified as an uli2; the general morphology and the dental wear are typical of a lower canine. tooth n. 206 lri2. originally identified as a lli2; the apex of the root is mesially tilted, as in a right incisor. 3.2. post-cranial remains the fragments of post-cranial bones (fig. 3) were originally identified as the distal diaphysis of an adult left humerus, a fragment of a right ulna attributed to an adolescent, and an incomplete left infant femur (boschian et al., 1995). the identification of the humerus (fig. 3 a, b) and the ulna (fig. 3 c) is confirmed whereas the fragment referred to as a femur (fig 3 d) is probably a fragment of the diaphysis of the posterior limb of a small ruminant; the reduced dimensions of the fragment prevent a more precise identification. as far as the interpretation of the markings on the bones is concerned, it is reasonable to consider them of an ancient origin, but there are no firm clues possibly linking them to some kind of intentional manipulation rather than to taphonomic damages. 3.3. individuals and ageing following the revision of the dental remains, the minimum number of individuals was also reconsidered, on the basis of wear, developmental and dimensional similarities of the teeth (tab. 1). as pointed out in the original paper (boschian et al., 1995), dental remains can be referred to 5 or 6 individuals at least (figs. 4-6). however, due to similarities in wear and morphology, most of the teeth originally assigned to individual 3 have been assigned to individual 6. the only exception is the lower left lateral incisor (tooth label n. 3), which is not compatible with individual 6; therefore it represents the only tooth assigned to individual 3. the two teeth not described in boschian et al. (1995), labelled 19 and 20, 54 fig. 3 post-cranial remains from riparo fredian. a) and b) fragments of a distal humerus; c) fragment of a diaphysis of an ulna; d) fragment of a posterior limb of a small ruminant, previously considered to be a sub-adult human femur. riga a. et al. 55 fig. 4 dental remains assigned to individual 1 (a), to individual 2 (b), and to individual 3 (c). fig. 5 a) dental remains assigned to individual 4; b) dental remains assigned to individual 5. modified after oxilia et al. (2017). human remains from riparo fredian have been assigned to individual 6. individual 4 and 5 are considered separate individuals, but it is reasonable to assume that they are from the same individual on the basis of dental wear since anterior tooth wear is generally far more advanced than molar wear in huntergatherers (willman, 2016). nonetheless, we cannot securely attribute these remains to the same individual due to the high level of fragmentation. the age of the six individuals was also revised on the base of tooth mineralization (alqahtani et al., 2010). both individual 1 and 2 have the apex of udi2 almost complete, and the differences between them are not significant. therefore, both individuals have been assigned an age of 18-24 months, whereas previous age estimate for individual 1 was between 12 and 18 months. as for the other individuals, wear stage is moderate on the lli2 (tooth label 3) of individual 3, suggesting a young adult. conversely, individual 4 and individual 5 heavily worn teeth suggest they belonged to mature adults. individual 6, with the root of the lower m3 half complete, and a moderate wear stage on anterior teeth and m1 is probably a young adult. 4. conclusions the revision of human remains from riparo fredian has led to several changes in their anatomical identification with respect to the original publications (boschian et al., 1995; mallegni, 2005). of the 39 teeth previously described, the analysis revealed that two of them belonged to animals, and 18 were mistakenly identified. a new, correct identification has been provided for each of them. also, two human teeth not described in the original papers have been identified. the anatomical identification of the post-cranial remains has been confirmed, except for the supposed sub-adult femur, which is actually a fragment of the posterior limb of a small ruminant. the minimum number of individuals, based on the dental remains, is confirmed as 5 or 6, although some teeth from individual 3 have been re-attributed to individual 6. the new identifications and the revised attribution of the teeth to the individuals led also to a reassessment of the age at death of the six individuals: the sample now is considered to represent two infants of 18-24 months (individual 1 and individual 2), two young adults (individual 3 and individual 6) and two mature adults (individual 4 and individual 5). the revision of the human fossils from riparo fredian is the first step in a more detailed analysis currently in progress, to reconstruct elements of the palaeobiology of this human group and to compare it with other contemporary italian populations. acknowledgements we would like to thank alfredo coppa for his useful comments on the manuscript. for this research irene dori has received financial support from the european union’s horizon 2020 research and innovation program under the marie skłodowska-curie grant agreement no 752626 (id). 56 fig. 6 dental remains assigned to individual 6. riga a. et al. references alciati g., pesce delfino v., vacca e. (eds.) (2005) catalogue of italian fossil human remains from the palaeolithic to the mesolithic. journal of anthropological sciences, 84 (supplement). alqahtani s.j., hector m.p., liversidge h.m. (2010) the london atlas of human tooth development and eruption. american journal of physical anthropology, 142, 481-490. biagi p., castelletti l., cremaschi m., sala b., tozzi c. (1981) popolazione e territorio nell’appennino tosco-emiliano e nel tratto centrale della pianura del po tra il ix e il v millennio. emilia preromana, 8, 13-36. boschian g., mallegni f., tozzi c. (1995) the epigravettian and mesolithic site of fredian shelter (in tuscany). quaternaria nova, v, 45-80. braschi s., del freo p., trevisan l. (1986) ricostruzione degli antichi ghiacciai sulle alpi apuane. atti della società toscana di scienze naturali, memorie serie a, 93, 203-219. castelletti l., cremaschi m. (1975) deposito mesolitico al passo della comunella (re). preistoria alpina, 11, 133-154. castelletti l., maspero a., tozzi c. (1994) il popolamento della valle del serchio (toscana settentrionale) durante il tardiglaciale würmiano e l’olocene antico. in: biagi p. & nandris j. (eds.), highland zone exploitation in southern europe, brescia, 28 april 1 may 1993. monografie di natura bresciana, 20, 189-204. cilli c., malerba g., tozzi c. (1998) analyse archeozoologique et modifications de surface des restes faunique de deux sites du paleolithique superieur de toscane (italie). in: facchini f., palma di cesnola a., piperno m., peretto c.. proceedings of the xiii international congress of prehistoric and protohistoric sciences, forlì, italia, 8-14 september 1996, volume 2. a.b.a.c.o. s.r.l., forlì, italy, 675-680. guidi o., pioli m., rossi g. (1985) il mesolitico della garfagnana. gruppo archeologico della garfagnana, barga, italy, pp. 229. guidi o., rossi g. (1984) ricerche archeologiche in garfagnana. gruppo archeologico della garfagnana, barga, italy, pp. 143. mallegni f. (2005) fredian. in: alciati g., pesce delfino v., vacca e. (eds.). catalogue of italian fossil human remains from the palaeolithic to the mesolithic. journal of anthropological sciences, 84 (supplement), 64-65. masini r. (1949) lembi di morene glaciali nella valle scesta (lima) e nella turrite di gallicano. atti della società toscana di scienze naturali – memorie serie a, 37, 55-89. notini p. (1973) stazioni preistoriche all’aperto in garfagnana (lucca). atti della società toscana di scienze naturali, memorie serie a, 80, 249-265. notini p. (1983) ritrovamenti preistorici sull’appennino tosco-emiliano, dal passo di pradarena al passo delle forbici. atti della società toscana di scienze naturali, memorie serie a, 90, 283-308. oxilia g., fiorillo f., boschin f., boaretto e., apicella s.a., matteucci c., panetta d., pistocchi r., guerrini f., margherita c., andretta m., sorrentino r., boschian g., arrighi s., dori i., mancuso g., crezzini j., riga a., serrangeli m.c., vazzana a., salvadori p.a., vandini m., tozzi c., moroni a., feeney r.n.m., willman j.c., moggi-cecchi j., benazzi s. (2017) the dawn of dentistry in the late upper paleolithic: an early case of pathological intervention at riparo fredian. american journal of physical anthropology, 163 (3), 446-461. smith b.h. (1984) patterns of molar wear in huntergatherers and agriculturalists. american journal of physical anthropology, 63, 39-56. vierin s. (2013) revisione dei reperti umani provenienti dal sito epigravettiano e mesolitico ‘riparo fredian’, molazzana, (lu). tesi di laurea, università di firenze. willman jc. (2016) the non-masticatory use of the anterior teeth among late pleistocene humans. ph.d. thesis, washington university in saint louis. 57 ms. received: april 26, 2018 final text received: september 30, 2018 human remains from riparo fredian 58 microsoft word 00_indice_lm04.docx il quaternario it issn 039-3356 italian journal of quaternary sciences 24 (1), 2011 11-39 alberto malatesta: 20 years of activity at the geological survey of italy francesco angelelli, maria letizia pampaloni, rita maria pichezzi & giulia ventura ispra istituto superiore per la protezione e la ricerca ambientale, roma corresponding author: g. ventura <giulia.ventura@isprambiente.it> abstract: angelelli f., pampaloni m. l., pichezzi r. m. & ventura g., alberto malatesta: 20 years of activity at the italian geological survey. this work illustrates the activity of the professor alberto malatesta as geologist and palaeontologist during his over 20 years-long career at the geological survey of italy and his important scientific contribution to the growth of the survey itself. primarily, his activity concerned: ٠ the geological survey to bring to fruition the geological map of italy at 1:100.000 scale; ٠ the recovery and identification of a large number of fossil specimens, collected during his geological surveys; over the years, they became part of relevant fossil collections hosted in the paleontological museum of the geological survey of italy, headed by a. malatesta himself. among the many tasks charges entrusted to a. malatesta, the following are worth to be remembered: ٠ applied geology consultant; ٠ member of the editorial board of the bollettino del servizio geologico d’italia since 1968; ٠ member of the italian committee of stratigraphy since 1970. ٠ acting director of the geological survey of italy. his scientific publications dealt with the various fields of geology. among them it is worth to remember the two paleontological monographs published on the memorie per servire alla descrizione della carta geologica d’italia about the italian plio-pleistocene mollusc faunas. riassunto: angelelli f., pampaloni m. l., pichezzi r. m. & ventura g., alberto malatesta: 20 anni di attività presso il servizio geologico d’italia. nel presente lavoro viene illustrata l’attività svolta dal prof. alberto malatesta nel corso della sua lunghissima carriera di geologo e paleontologo negli oltre 20 anni trascorsi presso il servizio geologico d’italia contribuendo con grande impegno scientifico alla crescita del servizio geologico stesso. la sua attività ha riguardato prevalentemente: ٠ il rilevamento geologico per la realizzazione della carta geologica d’italia alla scala 1:100.000; ٠ la raccolta e la catalogazione di numerosissimi reperti fossili, frutto delle campagne di rilevamento, che nel tempo hanno costituito vere e proprie raccolte conservate presso il museo di paleontologia del servizio geologico d’italia del quale a. malatesta fu il responsabile scientifico. tra i molteplici incarichi ricoperti dal prof. a. malatesta vanno ricordati quello di: ٠ consulente nel campo geologico-applicativo; ٠ membro del comitato di redazione del bollettino del servizio geologico dal 1968; ٠ membro della commissione italiana di stratigrafia dal 1970. direttore vicario del servizio geologico d’italia. numerose sono state anche le sue pubblicazioni che hanno spaziato nei vari campi delle scienze della terra. tra esse vale la pena ricordare le due monografie paleontologiche pubblicate sulle memorie per servire alla descrizione della carta geologica d’italia riguardanti le malacofaune plio-pleistoceniche italiane. key words: a. malatesta, geological survey of italy, geological maps, paleontological collections, pubblications. parole-chiave: a. malatesta, servizio geologico d’italia, carte geologiche, collezioni paleontologiche, pubblicazioni. 1. introduction a. malatesta developed the most part of his activity from 1950 to 1973, in the historical palace of the italian geological survey at largo di s. susanna in rome. at the third floor of the building, next to the exposition rooms of the paleontological museum, the entrance to his office was close to a bronze bust of quintino sella1, as if to en dear to himself the patronage of that great 1 quintino sella, italian politician and eminent scientist (1827-1884). for several times minister of the department of internal revenue (1862; 1864-65; 1869-73); in 1867 he founded the geological committee of italy, in 1868 he created in florence the executive committee of the geological map of italy, whose director was engineer i. cocchi; in 1881 he promoted together with capellini the foundation of the italian geological society. f. angelelli et al. 12 political and science man. a. malatesta started to work at the italian geological survey on the 1st of september 1950. he was the head of the scientific laboratory of the ministry for italian africa, and his task was the geological survey for the compilation of the official 1.100.000 geological map of italy, during which he also contributed to the collection and identification of numerous fossil remains (fig. 1). it is worth to remember, that the history of the italian official geological map started in 1861 when quintino sella, at that time minister of finance, sent a report to the ministry of agriculture, industry and commerce “sul modo di fare la carta geologica del regno d’italia” [about how to make the geological map of the italian kingdom]. the royal decree n°4113 issued on december 15th, 1867 founded the geological committee that was charged with (art. 2) “…la compilazione e pubblicazione della grande carta geologica del regno d’italia, e di dirigere i lavori, raccogliere e conservare i materiali e i documenti relativi” […the compilation and publication of the great geological map of italian kingdom, the direction of the works, and the collection and conservation of the relative materials and documents]. it was with the royal decree n°1421 (ser. 2°) of june 15th, 1873, that the guide-lines for the compilation and publication of the geological map of italy were pub lished, entrusted to a section of the royal corps of the mines under the high scientific supervision of the royal geological committee. in the same decree (art. 7) it was “…istituito l’ufficio geologico al quale è annesso uno speciale gabinetto nel quale verranno disposti e classificati i minerali, i fossili e le rocce raccolte nei lavori di campagna. nello stesso gabinetto saranno riuniti i libri, le carte e gl’istrumenti esistenti in firenze presso il comitato geologico” […established the geological office to which a special cabinet is annexed where minerals, fossils and rocks collected during the field surveys will be stored. in the same cabinet also all books, maps and instruments now located at the geological committee in florence, will took place] (sperandio & zanfrà, 1995). so, the first nucleus of the litho-mineralogical and paleontological collections and the library of the forthcoming italian geological survey was born. at the same time, the publication of the “bollettino del regio comitato geologico d’italia” [bulletin of the royal italian geological committee] and of the “memorie per servire alla descrizione della carta geologica d’italia” [memoirs for the description of the geological map of italy] was started to gather the field researches for the compilation of the geological map. the two journals had the aim to disseminate the geological researches developed in italy and funded by the italian government. during over one century from its foundation, the denomination of the royal geological office has changed several times, together with its location, up to the present denomination geological survey of italy-ispra (servizio geologico d’italia ispra) located in via curtatone 3, roma. one of the leading figure in the history of the geological survey of italy is certainly a. malatesta. during his over 20 years of permanence in the geological survey, he developed an incessant activity carried out with constant passion, commitment and professional competence. he was moved by the pleasure for the research and study more than by sense of duty, thus strongly contributing to the scientific growth of the geological survey itself. his activity mainly followed two tightly connected topics: the geologic survey for the realization of the geological map of italy at 1:100.000 scale and the collection and identification of fossil remains derived by his sampling and excavations during field surveys. his fossil collection represents the beginning of the paleontological collections of the geological survey of italy mantained at the palaeontological museum of which a. malatesta was the first scientific coordinator. although the authors of the present note are employees of the geological survey of italy, it has not been easy to reconstruct the career of a. malatesta during the years he spent working in the same institution. in fact, alberto malatesta: 20 years of activity at the geological survey of italy 13 scarce information has been found in the staff historical archive of the geological survey, since a lot of documents have gone lost due to the various movings of the survey during the last twenty years. nevertheless, thanks to the annual activity reports of the survey published in the appendix of the bollettino del servizio geologico d’italia, it was possible to find precious indications about charges and activities he carried out. 2. geological survey activity after the end of the 2nd world war, noticeable research founds were assigned to the geological survey of italy. in 1960 the law 3-1-1960 n. 15 (“sullo” law) was promulgated by the italian governement to edit, update and publish the geological map of italy at scale 1:100.000 and the related illustrative notes. all italian universities, public and private organizations and autonomous regions took part to such activity, under the qualified supervision of the geological committee, headed by ardito desio. malatesta became part of the staff of the during such a period of intense activity in almost every scientific research sector both in the field and in the laboratories. during his work at the geological survey of italy, a. malatesta contributed to the elaboration of many geological sheets, carrying out both the geological survey of the plio-pleisticene units and the palaeontological analyses on the fossil remains he had collected. in particular, he worked at the realization of the following geological sheets: n° 111 “livorno”, n° 272 “gela”, n° 192 “alghero”, n° 193 “bonorva”, n° 163 “lucera”, n° 175 “cerignola”, n° 197 “amalfi”, n° 149 “cerveteri”, n° 121 “montepulciano”, n° 122 “perugia”, n° 127 “piombino”, n° 148 “vasto”, n° 115 “città di castello”, n° 173 “benevento”, n° 167168 “isola rossa la maddalena”, n° 169 “caprera”, n° 256 “egadi islands” (unpublished) (fig. 2). in fig. 3 the original headings of the geological sheets at 1:100.000 scale, to the realization of which a. malatesta collaborated, are reported. not all the above mentioned sheets were featuring the illustrative notes (tab. 1). a. malatesta, although not mentioned among the authors, provided scientific contributions about plio-pleistocene macrofauna and field data for some of them. it is worth to note that, for different reasons (lack of topographical bases, insufficient funds, reduced staff, etc.), not all the geological field surveys ended with a printed geological sheet. anyway, even these unpublished activities are documented in the archive of the geological survey of italy. in the archive, for example, it is recorded the geological field survey of the sheet n° 256 “isole egadi”. figs. 4, 5, 6 and 7 illustrate the original handmade geological maps of the favignana and marettimo islands and the relative legends with autograph annotations. f. angelelli et al. 14 alberto malatesta: 20 years of activity at the geological survey of italy 15 f. angelelli et al. 16 numero foglio nome foglio anno di stampa autori malatesta 111 livorno 1954 a. malatesta note complete 163 lucera 1967 a. jacobacci, a. malatesta, g. martelli, g. stampanoni cap. iv, parag. b e cap. vi 175 cerignola 1967 a. malatesta, u. perno, g. stampanoni introduzione, cenni storici, stratigrafia (la serie pliopleistocenica), morfologia, geologia applicata 149 cerveteri 1967 f. dragone, a. maino, a. malatesta, a.g. segre stratigrafia da q a fi 121 montepulciano 1969 a. jacobacci, a. malatesta, g. martelli i sedimenti neogenici e quaternari 115 122 130 città di castello perugia orvieto (non rilevato da malatesta) 1970 a. jacobacci, c. bergomi, e. centamore, a. malatesta, n. malferrari, g. martelli, l. pannunzi, n. zattini cap. iv: stratigrafia tab. 1 list of the illustrative notes to which a. malatesta contributed. elenco delle note illustrative alla cui stesura ha partecipato a. malatesta. fig. 4 original geological map of the favignana island handmade by a. malatesta during october 1954. (housed in the collection of the department for librarian activities, documentary and for information of ispra -geological survey of italy). tavoletta originale dell’isola di favignana disegnata manualmente da a. malatesta nell’ottobre 1954, conservata presso la cartoteca del dipartimento per le attività bibliotecarie, documentali e per l’informazione di ispra (servizio geologico d’italia). alberto malatesta: 20 years of activity at the geological survey of italy 17 fig. 5 original geological map of the marettimo island handmade by a. malatesta in october 1954 (housed in the collection of the department for librarian activities, documentary and for information of ispra geological survey of italy). tavoletta originale dell’isola di marettimo disegnata manualmente da a. malatesta nell’ottobre 1954 e conservata presso la cartoteca del dipartimento per le attività bibliotecarie, documentali e per l’informazione di ispra (servizio geologico d’italia). 3. paleontological collections as already mentioned, together with the geological survey activity, a. malatesta studied, catalogued and organized the numerous fossil remains currently housed in the ispra museum of palaeontology. as curator of the “paleontological collections”, since his arrival to the geological survey of italy (1950), he carried on an intense research activity in paleontology, studying both the already housed remains and his quaternary fossil collection, acquired during his geological field surveys. through the study of the fossil invertebrate and vertebrate remains he collected, he was able to propose palaeogeographic, palaeoecologic and biostratigraphic reconstructions of several geographical areas. 3.1 historical notes to better understand the role of a. malatesta as curator of the paleontological collection of the geological survey of italy, it is useful to briefly illustrate the history of the collection from the origin to the present. the first reference to the mineralogical and geological collections of the geological survey is in the “rule for the execution of the royal decree n. 4113 of december 15th 1867” (signed by king vittorio emanuele ii in the foundation act of the royal geological committee), approved on august 30th 1868 by the office of agriculture, industry and commerce. the art. 16 reports “…le raccolte mineralogiche e geologiche le quali si andranno riunendo a misura del progredire dei lavori, e quelle di cui parla la linea c) dell’art. 24, saranno conservate come documenti autentici a corredo della carta stessa. nello scopo di conservarle e di renderle utili allo studio, il comitato formulerà una proposta sulla base di trarre profitto possibilmente da uno stabilimento già esistente, onde evitare le spese di un nuovo museo speciale”. likewise, the point c of the art. 24 above mentioned precises that “tutte le carte presentate all’accettazione del comitato dovranno essere corredate di un numero sufficiente di campioni geologici…..vi saranno uniti i campioni di rocce di buon formato, di minerali e fossili occorrenti alla perfetta intelligenza del lavoro, nonché una esatta descrizione del medesimo. questi oggetti, come pure i documenti presentati ed accettati, saranno conservati dal comitato e ne sarà disposto a tenore dell’art.16 (bollettino del regio comitato geologico d’italia, 1870, vol. i, pp. 11, 13). in the subsequent royal decree n. 1421, series 2 dated june 15th 1873, the art. 7 specifies that “all’ufficio geologico sarà annesso uno speciale gabinetto nel quale verranno disposti e classificati i minerali, i fossili e le rocce raccolte nei lavori di campagna...” (bollettino del regio comitato geologico d’italia, vol. 4, 1873, pp. 393394). on january 1st, 1874 the geological office moved to rome near the office of agriculture, industry and commerce. in 1875, a new location geological office f. angelelli et al. 18 was chosen at largo santa susanna, where the architect canevari planned and built a new building. to provisionally host the agrarian geological museum, the courtyard and part of the choir of the adjacent convent of holy maria vittoria was expropriated, with the justification of public benefit “….nelle poche camere avute in prestito nella scuola degli ingegneri di roma a s. pietro in vincoli, appena sufficienti per tenervi alcuni disegnatori; onde le collezioni già esistenti devono per ora tenersi quasi per intero incassate in magazzino” (giordano f., 18812). the new building was conceived to host the scientific material previously housed at different institutions: the royal school of application in turin, the museum of natural history in florence, the museum of natural history in pisa, the mining district of caltanissetta, the royal university in rome). on may 3rd, 1885, king umberto i officially opened the geological agrarian museum (fig. 8). two years after the museum opening, the collections already consist of over 10.000 remains (as it is recorded at p. 8 in the report cenno intorno ai lavori del comitato geologico nel 1877: “…le collezioni finora formate di rocce e fossili raggiungono il numero di 12 a 13,000 esemplari… e tuttodì si vanno accrescendo e classificando” (zezi p.3., 1878). since then, the collections substantially increased, thanks to the numerous fossils collected by the geologists during their field surveys for the compilation of the geological map of italy, and to donations, purchases, and exchanges with other national and foreign scientific institutions. at present, the palaeontological collection counts over 100.000 pieces. the fossil repository was placed at the third floor of the largo santa susanna building, together with four annexed offices. the first of those communicated with the exposition room and, initially, it was used for the fossils study and consultation. the fourth room, at the end of the corridor where the bust of quintino sella was placed (fig. 9), was assigned to a. malatesta who worked there throughout his permanence at the geological survey of italy. there he spent long time to rearrange the fossils, devoting himself to the painstaking work of cleaning, indexing and classification. he compiled tens and tens of labels by his own hand, each label placed almost always on the bottom of cardboard pillboxes in which the fossils were preserved, with the name of the species, the number of the samples and the place of origin. 2 felice giordano, chief inspector of the royal corp of mines in rome (since 1859) was a member of the royal geological committee from 1891, assuming its leadership for many years. 3 engineer of royal corp of mines, was editorial secretary and collaborator of royal geological committee of italy from 1870 to 1908. alberto malatesta: 20 years of activity at the geological survey of italy 19 fig. 7 -original legend of the geological sheet of the egadi islands with autograph annotations by a. malatesta (housed by the collection of the department for librarian activities, documentary and for information of ispra geological survey of italy). legenda originale delle isole egadi con annotazioni autografe del prof. a. malatesta conservata presso la cartoteca del dipartimento per le attività bibliotecarie, documentali e per l’informazione di ispra (servizio geologico d’italia). fig. 8 opening of the geological agrarian museum by king umberto i on may 3rd 1885 at the new office of largo s. susanna, 13. inaugurazione del museo geologico agrario in largo santa susanna 13, da parte del re umberto i il 3 maggio 1885. 3.2. present setting as already mentioned in the previous paragraph, currently the paleontological collections consist of a considerable number of remains (around 100.000), divided in several sections, a lot of which have a great importance for their scientific value and, not less important, for their historical and exhibition relevance. animals (marine and terrestrial) and plants, distributed along a time interval that spans from palaeozoic (cambrian) to quaternary (pleistocene and holocene) constitute the housed fossil collections. present day specimens for comparison are also present in the collection. the collections were originally divided in two large sections: a general one, taxonomically ordered, and a second, which included geographically confined collections, ordered following the different nature of sediments. furthermore, a remarkable number of fossil remains belonging to personal collections must be added. since the last century, these fossils were studied by many scientists that published the results of their researches as monographs or scientific works in prestigious italian and foreign scientific journals. in the years 1996-98 the museum was involved, for the first time from its constitution, in a cataloguing and inventory project. a rather structured data-base for the management of the collections themselves was realised (angelelli, 1992). in such circumstances the various collections of fossils were grouped in four sections: general collection (about 76.000 specimens) contains invertebrate remains collected during the geologif. angelelli et al. 20 cal surveys for the realization of the geological map of italy, and the research activities in the ex-italian african colonies. also fossils obtained by exchanges, purchases, and donations must be added. within the general collection some sub-collections such as didactics, great samples of isolated fossils, foreign sites, and ichnofossils are also included. historical collection (about 20.000 specimens) (angelelli, 2008), contains important collections including several taxonomic groups collected and studied, since the last century, by renowned scientists. the fossils are catalogued both taxonomically (graptolites, ammonites, rudists, ittiofauna) and by the name of the researcher who collected or studied them. among the main ones: g. bonarelli, m. canavari, g. di stefano, g. checchia rispoli, c. crema, g. curioni, t. lipparini, a. malatesta, g. meneghini. c.f. parona, r. rasetti, p. and vinassa de regny. these collections are of extremely scientific importance because they include many type-specimens (holotypes, lectotypes, plesiotypes, etc.). vertebrate collection (about 3.000 specimens) contains fossils belonging to the plio-pleistocene mammal faunas recovered from sedimentary deposits of latium, tuscany, sicily and of other italian regions. plant collection (about 600 specimens) includes both isolated remains mainly of palaeozoic pteridophytae and spermatophytae from germany and material from different italian localities, among which the mt. jano flora of the carboniferous of tuscany. 3.3 alberto malatesta collection this collection includes about 10.000 remains (divided in two sections: vertebrates and invertebrates) coming from the marittime alps, emilia romagna, umbria, latium, calabria, sicily, egadi islands and sardinia. it mainly includes plio-pleistocene fossils deriving both from the geological survey field campaigns carried out by malatesta and from sub-collections originally created by other scientists who preceded him such as crema, aragona, canavari, coppi, de stefani, lawley, loss, and nicosia. 3.3.1 invertebrate section among the many plio-pleistocene mollusc remains collected by malatesta, it is worth to mention in primis those coming from the deposits of grammichele (sicily) and in secundis the collection coming from the umbria intrapenninic basin. the studies on the fossils sampled in sicily and in umbria produced two important monographs, both published on the memorie per servire alla descrizione della carta geologica d’italia. the first one is entitled “malacofauna pleistocenica di grammichele (sicilia)”, published in 1960 (i part) 1963 (ii part) vols. xii; the second one is entitled “malacofauna pliocenica umbra”, published in 1974, vol. xiii. those collections and the two monographs represent still today two masterpieces for the studies of the plio-pleistocene marine molluscs of italy. the grammichele pleistocene fauna was collected during the geological field surveys in 1954, 1955 and 1958. the specimens mainly come from the deposits near catallarga and include 225 species and subspecies (123 gastropods, 4 scaphopods, 98 pelecypods), 3 of which acmaea (collisella) johannae, cantharus (pollia) fig. 9 bust of quintino sella, currently housed in the collection of the department for librarian activities, documentary and for information of ispra geological survey of italy. busto di quintino sella, attualmente conservato presso le collezioni del dipartimento per le attività bibliotecarie, documentali e per l’informazione di ispra (servizio geologico d’italia). advena and thericium (thericium) lividulum antiquum are new taxa (figs. 10, 11). the first two being holotypes have been illustrated in the catalogue of the types hosted in the paleontological collections of ispra (angelelli & rossi, 2004). moreover, at grammichele, thais (polytropa) lapillus represents the first recovery of this species in the mediterranean sea. this fauna counts over 550 samples of gastropods and about 730 among scaphopods and bivalves. it’s about a sublitoral fauna, a few deep sea”..”……poche decine di metri, con scogli e massi di rocce vulcaniche, coperti di laminarie e litotamni, fra i quali viveva una ricca epifauna di prosobranchi, mitili, ostriche e pettini. gusci di trochi e delle altre forme della popolazione intercotidale provenivano dalla sovrastante costa rocciosa. infine l’azione delle correnti ha permesso gli accumuli di resti di endofauna proveniente da banchi di sabbione tufaceo. mancano specie caratteristiche di fondi melmosi e di ambiente salmastro ad indicare una costa ripida, di fronte al mare aperto e lontana dallo sfocio di corsi d’acqua.”, as specified by the author (malatesta, 1960, p. 22). the pliocene molluscan faunas of umbria is much richer than the previous one both in quantity of picked material and in number of species, and it is the result of alberto malatesta: 20 years of activity at the geological survey of italy 21 fig. 10 plate x from angelelli & rossi (2004) illustrating the holotypes of acmaea (collisella) johannae malatesta (figs. 1a, b, c) and cantharus (pollia) advena malatesta (figs. 2a, b) from grammichele (sicily). plate x da angelelli & rossi (2004), nella quale sono illustrati gli olotipi di acmaea (collisella) johannae malatesta (figs. 1a, b, c) e di cantharus (pollia) advena malatesta (figs. 2a,b) provenienti da grammichele (sicilia). over one decade of researches, being collected during the geologic surveys on 1960-1965. around 9000 mollusc specimens have been picked, about 3000 of which are gastropods (2293) (fig. 12) and more than 6000 are bivalves (fig. 13). all those remains have been referred to 356 species or subspecies coming mainly from the umbria deposits located in the chianti, paglia and tevere valleys, and subordinately from tuscany (case nanni and poggio rotondo). the umbria collection is at present stored in special wooden chest of drawers in the historical hall of the paleontological museum (fig. 14). among the large collections of the geological survey of italy rearranged by a. malatesta, it is worth to remember the mollusc and echinid faunas from the eocene of briga and tenda (marittime alps). such fauna, collected by the engineer franchi during the survey of the geological sheet 91 “boves”, was studied by malatesta (1964) who strongly remarked its clear african affinity. 3.3.2 vertebrate section the studies published by a. malatesta on the vertebrate faunas of the plio-pleistocene italian basins and on the endemic fossils of sardinia and sicily gave a substantial contribution to the development of the knowledge on the fossil mammal faunas of italy. during the geological field surveys carried out by malatesta in the area of alghero (sardinia), abundant paleontological remains were collected in the marine and continental pleistocene deposits. one of the most important results was the discovery of a post-tyrrhenian ossiferous breccia filling a cave opened in the cretaceous limestones cliff of porto conte bay. there, the remains of a wild dog were recovered; they consist of skulls, limb bones and vertebrae. their study and the comparison with living and fossils species of cuoninae brought to their attribution to cuon sardous studiati, a fig 11 illustration of the type specimen of thericium (thericium) lividulum antiquum malatesta from plate iv of the monograph “malacofauna pleistocenica di grammichele (sicilia)” (malatesta, 1960). illustrazione dell’olotipo della nuova sottospecie thericium (thericium) lividulum antiquum malatesta tratta dalla tavola iv della monografia “malacofauna pleistocenica di grammichele (sicilia)” (malatesta, 1960). species erected more that one century before (malatesta, 1962). further recoveries and studies (malatesta, 1970) allowed to refer this species to the subgenus cynotherium, a fossil taxon recognized also from the villafranchian of china. the abundant and well preserved remains of the sardinian wild dog allowed the laboratory of the paleontology institute of “la sapienza” university to reconstruct an almost complete individual of cynotherium. currently, the fossil skeleton is preserved in its original wood and glass box (fig. 15) in the ispra headquarter of via curtatone 3. recently, within the institutional activities of ispra paleontological section, it has been accurately restored under the supervision of f. angelelli. in the alghero area, a further important recovery carried out by a. malatesta was the finding of a complete skeleton of an otter inside the neptune cave, near capo caccia (fig. 16). the examination of the skull, initially picked up by the speleologists of alghero and brought to a. malatesta, led him to guide personally a survey to recover all the remains. in fact, the skull showed a peculiar form, different from any living species. in the subsequent study, malatesta (1978) made a revision of all the fossil remains of the tertiary and quaternary lutrinae of eurasia and northern africa, in order to recognize possible affinities of the sardinian form. at the end, malatesta arose a new genus (nesolutra) and the morphological study of the whole skeleton evidenced the adaptation of the new species nesolutra ichnusae to the marine environment. this adaptation was also confirmed by the study of the encephalon (angelelli, 1995). moreover, a. malatesta re-examined several mammal collections stored in the paleontological museum, in particular those recovered by a.c. blanc from cava redicicoli (bufalotta, rome) and referred to the villafranchian mammal age. the abundant fossil remains were taxonomically revised and ascribed to mammuthus (arkidiscodon) meridionalis, equus altidens, stephanorhinus undsheimensis, hippopotamus ex antiquus, pseudodama sp., bison schoetensacki. on the whole, a. malatesta referred this fauna to the galerian mammal age. f. angelelli et al. 22 fig.12tav. xxx from the monograph “malacofauna pliocenica umbra” (malatesta, 1974) tav. xxx tratta dalla monografia “malacofauna pliocenica umbra” (malatesta,1974). fig.13 tav. viii from the monograph “malacofauna pliocenica umbra” (malatesta, 1974) tav. viii tratta dalla monografia “malacofauna pliocenica umbra” (malatesta,1974). alberto malatesta: 20 years of activity at the geological survey of italy 23 fig 14 historical hall of the “paleontological collections” hosting the chest of drawers containing the “malatesta collection” situated at the third floor of the geological survey at largo santa susanna, 13 rome sala storica delle “ collezioni paleontologiche” con le cassettiere in legno che ospitano la collezione malatesta, situata al terzo piano della sede del servizio geologico di largo di santa susanna, 13 roma. 4. publications as already mentioned, the scientific activity of a. malatesta, always driven by great passion, curiosity and constancy, showed his indisputed knowledges in both the geological sensu lato and paleontological fields. in fact, of the 54 publications carried out within over twenty years of employment at the geological survey of italy, about 24 are closely connected to palaeontology (7 concerning remains of vertebrates, 6 of which on mammals and 1 on bird, 13 concerning molluscs, 1 on echinoids and 1 on microfaunas), and 2 on more general topics such as general palaeontology and the application of binomial nomenclature, whereas 25 are more related to geological investigations, and 5 to archaeological researches. actually, such a classification of his publications is somehow forced, because in all his papers it is always evident his multidisciplinary approach that led him to face each single problem in the frame of a general context. this characteristic, revealed not only in the variety of the treated topics but also in each paper, made a. malatesta an “allaccomplished” researcher, who somehow went against the idea “of specialization” diffused in the academy. thanks to his non sectorial knowledge, a. malatesta could face a wide range of questions concerning palaeogeography, biochronostratigraphy, palaeoecology etc. analyzing his papers in a chronostratigraphic perspective, we notice that his scientific interests were primarily devoted to the problems related to the pliopleistocene and, more in general, to quaternary, although few researches were related to most ancient times, such as the “egadi islands fossiliferous trias” (malatesta, 1964a) and “eocene fossils of the territory of briga and tenda in the maritime alps” (malatesta, 1964b) related to the geological survey activities for the realization of the geological map of italy at 1:100.000 scale. even if most of his papers were published on italian journals (the half of which on the bollettino del servizio geologico d’italia), his vocational training and scientific authoritativeness were undisputed and appreciated also out of italy. among the works published during his twenty years at the geological survey that contributed in the most incisive way to the growth of the paleontological and geological knowledges and those that still today result f. angelelli et al. 24 unsurpassed (except for the updating of the systematic part) are certainly the two paleontological monographs written at a distance of about 10 years, both published on the memorie per servire alla descrizione della carta geologica d’italia: the first, dated 1960 (i part) and 1963 (ii part), entitled “malacofauna pleistocenica of grammichele”; the second, dated 1974, entitled “malacofauna pliocenica umbra”. they are precious tools not only for the malacologists, but also for all those researchers on stratigraphy. even if the two monographs are already been treated in chapter 3, we would like here to mention their contents. hereinafter, the 54 papers by malatesta are listed and for each a brief summary is given; sometimes the original summary is reported (given in italic and between inverted commas). the papers n. 14, 40, 41, 42, 44, 45, and 48 are related to the illustrative notes of the geological maps 1:100.000 and to the geological survey activity already mentioned in chapter 2; the works n. 32, 33, 34, 49, and 54 are also treated in the paragraph 3 paleontological collections. the works n. 3, 20, 33 have not been reviewed. 1. 1950 malatesta a., “sulla grotta reale di porto azzurro (elba)”. “investigations in the grotta di reale led to the discovery of fan intact portion of the pleistocene layer with ursus mediterraneus maj. from these deposits, last century excavations yield a rich mammalian fauna” 2. 1951 malatesta a., “considerazioni sugli ochotonidae fossili e viventi”. after the examination of the known data related to the most ancient forms of known duplicidentata, the author starts to analyse the fossil and living ochotonidae drawing a map of their palaeogeographic distribution and attempting a phylogenetic and palaeogeographic synthesis of the genus ochotona. 3. 1951 malatesta a., “ricerche preistoriche nella valle della lima (lucca)”. 4. 1951 malatesta a., “osservazioni sull’estensione dei ghiacciai quaternari nella valle di kangra (himalaya esterna)”. “l’estremo abbassamento del fronte dei ghiacciai quaternari sulle pendici meridionali del dhaola dhar (punjab, india), sostenuto dal theobald (1874-1880) è stato alternativamente accettato o messo in dubbio dai geologi indiani. l’autore espone una serie di osservazioni, compiute durante alcuni anni di permanenza nella regione, e ne trae la conclusione che in corrispondenza della iii espansione glaciale le fronti dei ghiacciai dovettero ivi discendere fino a quote intorno ai 1000 m s.l.m.” 5. 1952 malatesta a., “il calabriano tra castiglioncello e rosignano (livorno)”. “viene segnalata e descritta una serie di strati che unisce in continuità stratigrafica argille a cyprina, già segnalate, con panchine di quota elevata. vengono descritte e analizzate alcune faune che permettono l’attribuzione della serie al calabriano”. 6. 1953 malatesta a. & martelli g., “sull’origine ed età della porfirite di calabona (alghero)”. “dopo alcune osservazioni petrografiche su campioni del vecchio e di un nuovo affioramento di porfirite si espongono considerazioni geologiche sull’età e sulla messa in posto della roccia; procedendo ad un’analisi dei dati e delle ipotesi precedenti, si giunge ad attribuire l’età del dicco porfirico alla fine del cretaceo”. 7. 1954 malatesta a. & torrente a., “pliocene e pleistocene a caltagirone (sicilia)”. “è stata descritta la serie di un affioramento preva lentemente argilloso presso caltagirone f.273, sicilia -, esteso dal livello dei trubi fino al pleistocene. la distribuzione delle specie dei foraminiferi e dei molluschi mette in evidenza che il pliocene ha una potenza ridotta e che la transizione fra pliocene e calabriano è rappresentata da una facies salmastra; al calabriano propriamente detto è sovrapposto, con lieve discordanza, un livello più recente, definito genericamente “post-calabriano”. 8. 1954 malatesta a., “risultati del rilevamento del foglio 192 alghero, sardegna. note di stratigrafia quaternaria”. after a detailed exposition of the stratigraphical data concerning the pleistocene deposits of the alghero coast, the author concludes that at least two aeolian alberto malatesta: 20 years of activity at the geological survey of italy 25 formations of different ages are recognizable, as well as traces of two ancient shorelines at 5 and 30 meters s.l.m., presumably related to two different tyrrhenian transgressions. 9. 1954 malatesta a., “aluni risultati della campagna geologica (1953)”. in this paper some results related to the field surveys of sheets n°18 “sondrio”, n°192 “alghero”, and n°273 “caltagirone” are reported. more in particular, the stratigraphic and geomorphologic data on the quaternary deposits of the high val brembana (sheet “sondrio”) are discussed; observations related to the jurassic-cretaceous sediments of the i and iv quadrant of the “alghero” sheet are reported; the plio-pliestocene successions of the tablets iv° nw and sw of the “caltagirone” sheet are analyzed in a stratigraphic and tectonic perspective. 10. 1954 malatesta a., “risultati del rilevamento del f° 192 alghero, sardegna. fossili delle spiagge tirreniane”. “le spiagge fossili tirreniane di quota +5 del litorale di alghero contengono una ricca fauna di molluschi marini. l’autore fornisce un elenco di oltre 140 forme raccolte in quei depositi ed afferma trattarsi di uno dei più ricchi complessi tipicamente tirreniani noti nel mediterraneo settentrionale. seguono brevi considerazioni su alcune specie elencate e viene descritta la nuova forma purpura (stramonita) haemastoma linnaeus f. johannae n.” 11. 1954 malatesta a. & settepassi f., “risultati del rilevamento del f°192 alghero, sardegna. fossili delle formazioni continentali quaternarie”. 21 species of terrestrial and fresh water molluscs, 15 of birds and 5 of mammals coming from the breccias, aeolian sandstones and post-tyrrhenian travertines in the alghero area are listed. most of them are reported for the first time in the quaternary of sardinia, and some are not present in the present day fauna of the island. moreover, a new form of the terrestrial gastropod retinella incerta draparnaud n.f. oblivia is described (note n. 3). 12. 1954 malatesta a., “primo dente di elefante fossile rinvenuto in sardegna”. in this paper it is described the upper right m1 recovered in a post-tyrrhenian breccia near alghero, referred to e. lamarmorae (species next to e. meridionalis). for some characters, this tooth is comparable with the upper molars of the sicilian species e. melitensis. 13. 1954 malatesta a., “il cosidetto campanile della necropoli nuragica di s. andrea priu (bonorva)”. the author describes and illustrates a prehistoric monument of the nuragic necropolis of s. andrea priu in sardinia, which can be interpreted as a grave. its shape recalls a not identifiable zoomorphic figure (the anterior part of the head is missing), possibly a taurine image, very common in sardinia and often connected to buildings of burial and cult. 14. 1955 malatesta a. & segre a.g., “f° 111 livorno. note illustrative della carta geologica d’italia”. it is worth to underline that a. malatesta alone carried out the layout of this note, as well as the whole sheet survey, wherehas a.g. segre developed the continental and marine hydrography. this is also documented by the words of beneo, at that moment director of the geological survey of italy, when, in the 1951 activity annual report textually wrote “… si è realizzato in pochi mesi, ad opera del dott. malatesta il completamento del rilievo ex novo del foglio 111 (livorno), ora praticamente pronto per la stampa della 2° edizione.” (beneo, 1951). since leghorn was the native town of malatesta, it is perhaps easier to understood how much the enthusiasm and the knowledges already previously acquired by a. malatesta could have contributed to give those definitive results in such a brief time. particularly interesting are the considerations on the genesis of the conglomerate of calafuria, aged oligocene-miocene, in which the presence of a marine bivalve fauna suggested its deposition in a marine coastal environment. 15. 1955 malatesta a., “risultati preliminari del rilevamento in sicilia e nelle isole egadi”. here, the sediments cropping out in the grammichele area (trubi fm., tufa and sandstones) and the recent deposits of the egadi island are shortly described. at favignana the calabrian-tyrrhenian deposits are covered by reddish sands while at levanzo and marettimo only the tyrrhenian deposits are present, followed by aeolian dunes at levanzo and by breccias at marettimo. 16. 1955 malatesta a. & nicosia m.l., “i fossili del pliocene e pleistocene di agrigento della collezione lomi”. the list of 183 piacenzian and calabrian species is reported. particularly, the calabrian fauna is composed by 9 echinodermata, 4 bryozoa, 70 bivalvia, 72 gastropoda and 8 scaphopoda, while the piacenzian one, less diversified, consists of 7 bivalves, 12 gastropods and 1 scaphod. it is to be remarked that 88 calabrian species were not yet reported at that time. 17. 1955 malatesta a., “faune a cyprina islandica l. tra piazza armerina e mazzarino (sicilia centromeridionale)”. “una nuova località fossilifera individuata presso s. cono (piazza armerina) ha fornito una piccola fauna nella quale appare assai di frequente cyprina islandica l.; questa specie è stata raccolta anche recentemente nel nuovo giacimento di m. navone. le faune delle due località non sono sufficienti a definire se si tratti di pliocene superiore o di calabriano sebbene nei molluschi vi sia una certa tendenza verso il più recente, l’associazione dei f. angelelli et al. 26 foraminiferi indicherebbe piuttosto il pliocene (astiano). poiché gli orizzonti fossiliferi sono in continuità stratigrafica con formazioni sicuramente plioceniche, se ne deduce la possibilità che queste faune coincidono con una precoce introduzione di cyprina islandica.” 18. 1955 malatesta a., “denticulina doderleini d. st. nel pliocene inferiore della sicilia”. “sono indicate due nuove località fossilifere nel pliocene inferiore della sicilia. la fauna contiene, insieme a poche altre specie, molti esemplari di denticulina doderleinii d. st., specie generalmente ritenuta come caratteristica nel miocene siciliano. la posizione stratigrafica di uno dei giacimenti e lo studio dei foraminiferi eseguiti dal professor lipparini garantiscono in questo caso l’età pliocenica. frammenti della roccia marnosa ancora aderente ad esemplari di denticulina doderleini d. st. nella classica località di centuripe, ritenuti di età miocenica, hanno permesso di riconoscere una fauna di foraminiferi simile alla precedente e perciò pliocenica.” 19. 1955 lipparini t., malatesta a., nicosia m.l. & valdinucci a., “pliocene e quaternario di capo milazzo in sicilia”. the conglomerate deposits that crop out on the terrace surface of cape milazzo are described allowing the following observations: 1) the conglomerates and the yellow marl represent only a part of a sedimentary cycle, whose upper levels have been removed by the successive erosion cycles; 2) they correspond to the basal layers of the piacenzian of barcelona surroundings; 3) they contain a fauna made of foraminifers, corals, echinoderms, brachiopods, molluscs and fishes, which allow to establish their pliocene age with certainty. besides, it was pointed out the existence of two different marine terraces previously not recognized: a) an high terrace uplifted from 25 to 60 m a.s.l. bearing rich mytilus and trochidae fauna (ex milazzian in age); b) a low terrace uplifted from the present sea level up to 3 m, bearing a scarce and not significative fauna. no tectonic movement has altered the relative position of the terraces. the problem of their age will be solved only through the palaeontological analyses, but at the moment it is not correct to ascribe them neither to the sicilian nor to the tyrrhenian ages. 20. 1956 malatesta a., “conchiglie”. 21. 1956 malatesta a. & motta s., “notizie preliminari di geologia messinese”. in this paper the observations derived from the geological survey of the three tablets iv so “messina”, iv ne “ganzirri”, and iv no “castanea” (of the sheet n°254 “messina”) are reported. starting above the crystalline basement, the analyzed deposits are made of sandstones, sands, tripoli, limestones and puddingstones marls that must be referred to the miocene-calabrian interval. 22. 1956 jacobacci a., malatesta a & martelli g., “prime notizie sul nuovo rilevamento geologico dei monti peloritani”. the lithological-stratigraphical series of the peloritani mts. is preliminarily reconstructed following the geological survey of the tablets i sw “milazzo”, ii nw “castroreale”, iii-ne “furnari”, and iii-nw “patti”, of the sheet n°253 “castroreale”. above the metamorphic complex basement, the following sedimentary formations have been recognized (from the base to the top): a) clastic basal deposits; b) variegated clays, schist clays associated with heterogeneous lithoid pebbles; c) arenaceous puddingstones complex (lower and middle miocene in age); d) tortonian sediments; e) solfiferous complex; f) middleupper pliocene deposits; g) calabrian deposits bearing cyprina islandica and buccinum undatum; h) terraced conglomerates; i) quaternary marine deposits (aged milazzian and tyrrhenian). 23. 1956 malatesta a. & segre a., “considerazioni paleontologiche e sistematiche su turris (fusiturris) undatiruga biv”. “la rarità di questa specie vivente, e fossile (gignoux 1913, non la cita) ha suggerito una revisione sistematica. si confrontano le diagnosi degli aa. a cominciare dal bivona p., e si riportano le località ove è stata rinvenuta fossile (siciliano e tirreniano) e vivente:dall’equatore al 38° lat. nord. nel mediterraneo manca sulle coste di spagna, francia e italia peninsulare ed è assente dall’intero bacino orientale. vive piuttosto in profondità nei fondali a corallinacee oltre i 50 m: è specie senegalese e mediterraneo-africana a tendenza relativamente “calda”. chiarite le differenze tra i gen. turris e surcula si riconosce che pleurotoma similis biv., pl.balteata beck, pl.corrugata kiener, pl.tenue gray, pl. becki wkauf. non sono che forme viventi della pl. undatiruga biv. tutte limitate nell’ambito della variabilità della specie. nella letteratura estremamente sparsa esistono incertezze e confusione. si nota tutt’al più una forma maggiormente elongata con 10-12 anfratti, ed una più tozza, corta, con circa 9 anfratti l’ornamentazione mostra differenze minime. questa specie è sempre rara, sia fossile, sia vivente, onde va accolta con prudenza l’apparenza più massiccia e robusta degli esemplari fossili più antichi.” 24. 1957 malatesta a., “terreni, faune e industrie quaternarie nell’arcipelago delle egadi”. the deposits outcropping at favignana, levanzo and marettimo are here described on the basis of the data collected during the geological survey of the sheet n°256. at favignana, above the prequaternary successions, the calabrian sandstones and tyrrhenian beaches crop out. the last one are referable to: tyrrhenian i deposits (cropping out at alberto malatesta: 20 years of activity at the geological survey of italy 27 30 m a.s.l.); tyrrhenian ii beaches bearing strombus (at 5 m a.s.l.), as well as post-tyrrhenian sands bearing terrestrial molluscs. at levanzo a well evident strombus beach rests on the mesozoic limestones; it is followed by sands bearing pulmonates and breccias overlayed or intercalated to aeolian sands. at marettimo, the well represented tyrrhenian beach at 5 m a.s.l. unconformably overlies the triassic limestones, and the jurassic and paleogene deposits. although this beach does not bear strombus, remains of spondylus, purpura and large patella are enough to confirm its tyrrhenian age. 25. 1957 malatesta a., “on thais (polytropa) lapillus lapillus (linne’) in the pleistocene of sicily”. for the first time in the mediterranean sea, the presence of thais (polytropa) lapillus lapillus (linnè) is pointed out, collected at the sicilian pleistocene site of grammichele. this species have never been signaled neither as fossil nor in the living state. on the base of the present and past distribution of the subgenus polytropa, the author proposes that the origin of its diffusion is from the low boreo-arctic bioprovince. 26. 1957 malatesta a. & pannuti s., “giacimento preistorico di superficie presso acilia”. the presence of a prehistoric human settlement is reported to the ne of acilia, from a quite superficial level immediately below the agrarian soil. the analysis of over 150 siliceous tools (among which nucleuses, splinters and blades) led the authors to refer them to the “pontinian” lithic facies of the latium musterian. 27. 1958 malatesta a., “osservazioni sul pliocene e il pleistocene della costa settentrionale della sicilia tra gualtieri-sicaminò e gioiosa marea”. “tra gualtieri sicaminò e gioiosa marea, lungo la costa settentrionale della sicilia, sono estesamente sviluppati terreni pliocenici e quaternari sinora stratigraficamente e paleontologicamente poco noti. gli affioramenti del pliocene sono i più limitati perché in parte smantellati dall’erosione, in parte coperti dai terreni pleistocenici. la base del pliocene rappresentata dai “ trubi “ è qui spesso discordante rispetto ai terreni precedenti. vengono indicate alcune località dove è visibile un conglomerato di base. mentre nel bacino di castroreale la serie si continua con argille di facies piacenziana, nel bacino di patti si sviluppa una facies arenacea, simile a quella delle masse, presso messina. il calabriano è rappresentato da una serie arenaceo calcarea discordante sulle formazioni precedenti. in questa serie sono state individuate alcune località fossilifere delle quali viene elencata la malacofauna, che comprende pecten maximus, chlamys septemradiata e cyprina islandica. le dislocazioni presenti indicano che la posizione di questi terreni risulterebbe nel complesso abbassata rispetto alla dorsale cristallina dei peloritani. si hanno invece prove di una trasgressione postcalabriana (siciliano di gignoux?): conglomerati di base sul calabriano a +50, puddinghe sospese sul cristallino a +70, grotte e fasce di fori di litodomi fino a circa +90. questi antichi livelli della linea di riva si raccordano probabilmente con i depositi del cosi detto “milaziano” di capo milazzo. i conglomerati marini passano superiormente a grandi depositi alluvionali, che formano una fascia costiera pianeggiante a partire da 135 s.l.m. queste alluvioni si sarebbero deposte in fase eustatica regressiva e sarebbero legate alle condizioni paleoclimatiche di queste zone in corrispondenza della fase anaglaciale. 28. 1958 malatesta a., “cenni sui risultati delle campagne geologiche effettuate durante l’anno 1956”. the paper includes further observations on the molluscan fauna collected in the tortonian clays at patti (sicily) that appears a mixed assemblage with typical marine tortonian and brackish pontian facies. moreover, it is shortly described the pliocene mollusc fauna of casteloto (benevento). 29. 1959 malatesta a.,”notizie preliminari su una fauna del pleistocene siciliano”. the author mentions the main characters of the grammichele molluscan fauna, concluding that typically cold pleistocene species such as neptunea, buccinum, cyprina and thais lapillus occurred together with temperate-warm species such as patella ferruginea, polynices lacteus, pisania reticolata and turris undatiruga. particularly, the presence of the last three species would prove “che la penetrazione nel mediterraneo di forme di tipo senegalese non fu esclusiva prerogativa dell’ultimo interglaciale e che alcune di tali forme poterono occasionalmente vivere in contemporaneità con le faune a carattere boreale”. 30. 1959 malatesta a., “note di geologia e geomorfologia della valle caudina e sulla valle del fiume calore”. the geologic setting of two valleys of the beneventano area is described. particularly in the caudina valley, resting above the cretaceous limestones, arenaceous sediments attributable to the miocene, followed by pliocene sediments with clays of the “piacenzian” facies overlayed by sands and sandstones have been recognized. grey tuffs of posttyrrhenian age crop out at the top of the succession. the geologic setting of the cadore valley is more complex. concerning the cadore river “il cui profilo longitudinale è legato all’altezza di sbocco nel fiume volturno, le fasi di alluvionamento debbono corrispondere nel complesso a periodi glaciali e le fasi di incisione a periodi interglaciali”. several terraces, the lowest of which was referred to the würm glacial stage (confirmed by a lacustrine molluscs fauna) and the highest to the penultimate glaciation, have been also recognized. 31. 1959 malatesta a., “di un livello fossilifero attraversato dalla galleria di bomba nella valle del sangro”. eleven species of molluscs collected in calcareous breccias within supposed cretaceous clays are described in the present paper. paleontological analysis allowed to refer this outcrop to an age not more f. angelelli et al. 28 fig.17 premise and geological map of the calabrian deposits cropping out in the grammichele area at the fossiliferous site of catallarga (malatesta, 1960). premessa e carta geologica relativa al calabriano nel territorio di grammichele e la zona fossilifera di catallarga (malatesta, 1960). ancient than pliocene, due to the presence of pecten planomedius and chlamys pesfelis. 32. 1960 malatesta a., “malacofauna pleistocenica di grammichele (sicilia). parte i”. (fig. 17). this monograph represents “the first outstanding research” that a. malatesta left to the paleontological community. this study is of particular importance since it includes the richest calabrian fauna known till then in sicily. this first part is divided in 4 chapters. in the first the composition of the fauna with the list of the collected species, notes on their ecology, considerations on those species “survived” or derived from the neogene mediterranean fauna of indo-pacific origin (about 12%), and information on the new guests of extra-mediterranean origin are described. the second chapter devotes different pages to the problems of the immigration of the atlantic species in the mediterranean, that occurred during the glacial phases. in the third chapter, the problem of the classification is discussed, particularly the difficulties to compare the examined fauna with the species and the sub-species types. finally, in the fourth chapter devoted to the taxonomy of gastropods, for each species the taxonomic position (including synonymy), dimensions, and number of the collected specimens are provided. furthermore, for each species stratigraphical, ecological and palaeogeographic information are given. 33. 1961 jacobacci a., malatesta a. & motta s., “piano di studi nello stretto di messina per il collegamento della sicilia con la calabria. i ricerche geologiche”. 34. 1962 malatesta a., “mediterranean polyplacophora, cenozoic and recent”. a study about the origin and the diffusion of the present mediterranean polyplacophoras is discussed. for each of the 13 species represented in the mediterranean sea, the author gives the description of the morphological characteristics of the plates accompanied by schematic sketches and maps with their distribution from the neogene to present, in order to better clarify their origin and diffusion from cenozoic to present. lepidopleurus (lepidopleurus) cajetanus, lepidopleurus (lepidopleurus) cancellatus, hanleya hanleyi, lepidochitona alberto malatesta: 20 years of activity at the geological survey of italy 29 (lepidochitona) cinereus, ischnochiton (ischnochiton) rissoi, chiton (chiton) olivaceus, chiton (chiton) corallinus, acanthochitona communis, middendorffia caprearum are endemic mediterranean species widespread since the mio-pliocene; lepidopleurus (lepidopleurus) asellus, lepidopleurus (lepidopleurus) algerinensis, callochiton (callochiton) achatinus, acanthochitona (acanthochitona) fascicularis immigrated from the atlantic into the mediterranean in the middle-early pleistocene; for callochiton (callochiton) achaticus a mediterranean origin in rather recent times is very probable. 35. 1962 malatesta a., “il cane selvaggio del pleistocene di sardegna”. in this paper, the bone remains (skulls, jaws, vertebrae, and limb bones) collected near alghero within an ossiferous breccias post-tyrrhenian in age are described. they have been referred to cuon (cynotherium) sardous (studiati). this species is characterised by a rather narrow and lengthened head and short limbs, intermediary between the jackal and the lycaon. the morphology of the teeth revealed an exclusively carnivorous attitude, since they were not adapted to the bone trituration. remains of deer bones connected to the recovery of cuon suggested that the deer was its usual prey. since the preys were larger-sized than the predators, it is possible to suppose that c. (c.) sardous probably chased in group. 36. 1963 malatesta a., “malacofauna pleistocenica di grammichele (sicilia). parte ii”. the second part of the grammichele monography was published with a remarkable delay in comparison with the first one, due to lack of funds. it contains the completion of the iv chapter on taxonomy, dealing with scaphopoda and bivalvia classes, and by a v chapter devoted to the geographic and stratigraphic distribution of the mollusc species, with analytical indexes and bibliography. 37. 1964 malatesta a., “fossili eocenici del territorio di briga e tenda”. “l’ing. franchi s., cui si deve una parte del rilevamento del foglio boves (n.91 della carta geologica d’italia), raccolse una serie di campioni fossiliferi in terreni eocenici dei monti di briga e tenda nelle alpi marittime. questo materiale, conservato nelle collezioni del servizio geologico d’italia, era rimasto sino ad oggi inedito. l’autore pubblica qui il risultato dello studio dei resti dei molluschi ed echinidi. si tratta di 17 bivalvi dei quali è stato possibile riconoscere la specie e di uno indicato solo genericamente, di 14 di gasteropodi e di un echinide. la distribuzione stratigrafica delle forme segnalate indica un’ètà compresa tra l’eocene medio e l’eocene superiore (luteziano-priaboniano). notevole è la presenza di forme a carattere meridionale, africano.” 38. 1964 malatesta a., “trias fossilifero a marettimo nelle isole egadi”. the fossiliferous levels bearing mollusc faunas in the marettimo island are here reported. the recognized species modiolus paronai, modiolus gracilis, pleuromya cf. musculoides, lexonema obsoletum, climbed undularia?, and omphaloptlcha turris suggest an age near to middle-upper triassic with “suggestione preponderante verso il carnico-retico. nella faunula compaiono forme sia della facies germanica che di quella alpina” [preponderant suggestion toward the carnico retico. in the faunula appear forms both of the german and of the alpine facies.] . the small sizes, according to the author due to dwarfism as already pointed out in other triassic faunas, are also underlined. 39. 1964 malatesta a., “uber einige pleistozane susswassermollusken aus mittel-italien”. for the first time, the continental molluscan faunas collected from the pleistocene deposits of tuscany and umbria are broadly described and discussed; in this occasion a new subspecies viviparus bergeroni etruscus is arised. the other examined forms are: unio pillae, margaritifera (pseudunio) auricularia, and corbicula fluminalis. 40. 1967 dragone f., maino a., malatesta a. & segre a.g., “f° 149 cerveteri. note ill”. within the geological survey for the sheet “cerveteri” a. malatesta worked in the northern part on the quaternary stratigraphy (from q to f1 terrains), describing the marine clays/sands and the fluvial lake/deltaic sequences, both from a sedimentologic and paleontological point of view (from microfaunas to vertebrates). geological profiles and stratigraphic logs are also provided to better clarify some geometric relations such as the escarp near the torre in pietra castle or the regular slope of the vallone of pratolungo between pagliaccetto and torre in pietra localities. 41. 1967 jacobacci a., malatesta a., martelli g. & stampanoni g., “f°163 lucera. note ill”. together with g. stampanoni, a. malatesta carried out the stratigraphical study of the pliocene-calabrian and quaternary sediments of the sheet “lucera”. he studied also the collected molluscan faunas. 42. 1967 malatesta a., perno u. & stampanoni g., “f.° 175 cerignola. note ill”. in this note, a. malatesta contributed to write several chapters (introduction, historical signs about geological knowledge of the region, morphology, applied geology). together with g. stampanoni, he described the plio-pleistocene successions, and he put in evidence that the clayey-sandy complex, characterized at the base and the top by conglomerated episodes, represented a whole sedimentary cycle, although the upper terms may have included secondary episodes of sea oscillations and flooding. 43. 1967 conato v., malatesta a. & valletta m., “calabriano ad acrtica islandica sulla costa meridionale d’abruzzo”. during the geological survey of the “vasto” sheet, some fossiliferous levels were found along a clayey escarpment near km 520 of the “adriatic” highway (locality salce sheet 148 at 1:100.000 scale igm tab. ii ne casalbordino). they bore arctica islandica and a characteristic calabrian microfauna including f. angelelli et al. 30 astrononion citai, bolivina catanensis and leptocythere multipunctata, allowing “... di definire l’età dei sedimenti della costa meridionale dell’abruzzo, e di aggiungere un nuovo dato circa la diffusione di quel bivalve nel mediterraneo pleistocenico “ [to define the sediments age of the abruzzo southern coast and to add a new datum about the diffusion of that bivalve in the mediterranean pleistocene]. 44. 1969 compagnoni b., conato v., follieri m. & malatesta a., “il calabriano di scalea”. along the calabrian coast, during the survey of the tablet ii no “scalea” of the sheet n° 220 “verbicaro”, sandy-clayey sediments were sampled and provided a microfauna with globigerina dubia, g. pachyderma, hyalinea balthica, globorotalia inflata, loxostoma pseudodigital, and 105 species of molluscs with the 10% of extinct forms. this percentage was higher than those displayed by the classical sicilian faunas and a little bit lower than that of the grammichele calabrian layers. these data suggested for the sediments of scalea a lower calabrian age. the recovered vegetable remains attributed to fagus silvatica, pinus and abies suggested relatively cold climatic conditions. the sedimentary succession, interrupted at the top by an erosional surface, continued upwards with conglomerates and sands referable to the sicilian age. terraced sediments, with pebbles, referable to the tyrrhenian i or to the milazzian stages close the succession. 45. 1969 jacobacci a., malatesta a., martelli g., “ f° 121 montepulciano. note ill”. as specified in the introduction “a. malatesta ha rilevato i sedimenti plio-pleistocenici della parte centroorientale del foglio (val di chiana)………. ha diretto e coordinato gli studi nei sedimenti più recenti……lo studio delle macrofaune plio-pleistoceniche è stato condotto da a. malatesta e m.l. nicosia”. in particular, on the basis of geologic-stratigraphical sections, a. malatesta described the p1-m3 deposits, underlining the progressive predominance of conglomerates in the upper part of the succession. he referred the pebble deposits to the pliocene series and clarified the geometric relations between the fluvial-lacustrine and marine pliocene deposits. 46. 1969 malatesta a., “conchiglie di mare che si raccolgono in terra”. this short note includes a brief description of the fossilization processes of mollusc shells, followed by the description of 8 species of living molluscs: 4 species of murex e 4 of voluta. 47. 1969 malatesta a., “conchiglie di mare che raccolgono a terra un gruppo scomparso di bivalvi: le rudiste”. this one-page short article illustrates, with simplicity but at the same time with scientific rigor, the rudist fossil group. 48. 1970 jacobacci a., bergomi c., centamore e., malatesta a., malferrari n., martelli g., pannuzzi l. & zattini n., “f°115 città di castello, f° 122 perugia, f° 130 orvieto. note ill”. the contribution of a. malatesta to this note is related to the stratigraphy of “città di castello” and “perugia” geologic sheets of which he was the survey director and the plio-pleistocene macrofauna analyst. he underlined that” i sedimenti marini, o prevalentemente tali, di età pliocenica affiorano nelle serie occidentali dei fogli “perugia “ ed “orvieto” e sono in evidente trasgressione su tutti i sedimenti più antichi: si tratta di litofacies esclusivamente clastiche, con elementi da finissimi a grossolani. i depositi plio-pleistocenici di facies continentale appartengono a più cicli di deposizione ed anch’essi presentano facies prevalentemente clastiche”. 49. 1970 malatesta a., “cynotherium sardous studiati an extinct canid from the pleistocene of sardinia”. “the first remains of a fossil dog found in sardinia were formerly regarded by studiati as rapresentant of a new genus and species, cynotherium sardous. the rich material recentely come to light in a cave, from a layer correlated to the wurm glacial stage, allows to get a complete description of the skeleton of that species. in the general form of its dog is more similar to species of the genus canis than to any representant of the cuoninae. even the mandible differs from the cuonine pattern and shows rather a fox-like profile, being elongated, straight and slender, with condyloid process placed low in comparison with the alveolar border. there are in the skull, some peculiar characters, such as lyrate sagittal area, small bullae, long frontals with small postorbital processes, narrow palatine. high and swollen maxillary, that distinguish it form the skull of whichever known living or fossil dog. the dental formula is: i 3.3, c 1.1 , p 4.4 , m 2.2 . 3.3 1.1 3-(4) . 3-(4) 3.3 most probabily cynotherium diet consisted mainly of small mammals, birds and other small animals includes prolagus”. 50. 1970 malatesta a., “nascita della nomenclatura binomia e della classificazione”. this paper represents a short historical excursus on the birth of taxonomy. with the use of the binomial nomenclature and the latin language, the linguistic barriers are overcome, allowing the scientists of the whole world to understand each other using the same taxonomical language. 51. 1971 malatesta a., “appunti di paleontologia generale”. this text-book was written for the students of the course of paleontology at “la sapienza” university of roma. several palaeontological topics are treated in a clear and exhaustive way: fossilization, evolution, concept of genus, geographical distribution, mechanisms of speciation, environment, actualism, and elements of statistics, as well as a complete exposition of the invertebrate taxonomy, and some information about fossil vertebrates and plants. 52. 1971 malatesta a., suriano f., “avifauna pleistocenica di alghero (sardegna)” in this paper, the fossil remains of about 20 species alberto malatesta: 20 years of activity at the geological survey of italy 31 of birds collected in a pleistocene layer cropping out at the “cala della calcina” inlet near porto conte (alghero) are described. besides the morphological description of the bony remains, the frequencies of each recognized taxonomic group are mentioned: the mostly represented are columbiformes, falconiformes and passeriformes. the occurrence of some anatidis (colymbus, anser, and branta and of pyrrhocoras pyrrhocoras), currently absent in the sardinian fauna, points out relatively cold and damp climatic conditions referable to the würm glacial. 53. 1974 caloi l. & malatesta a., “il cervo pleistocenico in sardegna”. this paper describes and discusses the very abundant bone remains belonging to the cervid megaceros (nesoleipoceros) cazioti (deperet), recovered in the dragonara cave, near alghero and referable to the würm age. the fossil material was collected during 15 years of repeated excavation campaigns. the main morphological characteristics of the species can be synthetized as following: notably high teeth, and antlers with notable affinities with those of megaceros verticornis but differing for the absence of the beam right angle. concerning the proportion of the limb bones, a shortening of the proximal segments is noticed, with an elongation of the distal ones. the proportions between anterior and posterior limbs is similar to those of cervus elaphus, while the percentage ratio between the vertebral column and limbs length is comparable to that showed by rusa unicolor. the proportions of the limb bones, the presence of strong hoofs and the tilted pastoral point out strong adaptation to run and to move in rocky environment. “circa la penetrazione degli antenati di m.cazioti nelle isole diverse considerazioni indicano che la migrazione verso queste regioni non potè iniziarsi prima del siciliano” inoltre “… la povertà delle mammalofaune quaternarie ed attuali di sardegna e corsica mostra che durante il viaggio attraverso quei ponti continentali si dovette esercitare una drastica azione filtrante tra le specie emigranti” “i resti di m.cazioti provengono generalmente da depositi wurmiani ma anche quelli raccolti in depositi più antichi (capo figari) non presentano caratteri diversi da quelli tipici della specie. poiché neppure sul continente si riscontrano forme fossili che possano rappresentare fasi di transizione tra m.cazioti ed il suo presunto antenato (m. vertcornis), si suppone che il processo di differenziazione si sia svolto in una zona oggi sommersa dall’antico ponte continentale.” 54. 1974 malatesta a., “malacofauna pliocenica umbra”. (fig.18) fig. 18 title page and introduction to the “malacofauna pliocenica umbra” (malatesta 1974). frontespizio e introduzione della “malacofauna pliocenica umbra”(malatesta,1974). f. angelelli et al. 32 published in 1974, this monograph is the result of over one decade of researches. it concerns 356 species and/or subspecies of molluscs coming from the pliocene deposits of umbria and, partially, of tuscany. it is a complete monographic work in which for every species the following items are provided: taxonomy, synonymy, description and discussion of the distinctive characters (with information about the number of collected specimens, their dimensions and indication of the layers of origin), chronological and geographical distribution, ecology, and, finally, some general considerations. for some species, considered more meaningful, the variation of their geographical distribution is reported for the different periods of cenozoic era, sometimes up to the present day. those variations are shown through geographical maps (24 in total), with the intent to evidence the dispersion areas of the different species through different times. moreover, a scheme with the distribution of the forms described in the european basins (north sea, european atlantic and mediterranean) and northern africa (african atlantic) from the cenozoic to the present is also provided. the value of this monograph is completed by the presence of 32 photographic black and white tables. 5. other tasks 5.1 applied geology consultancy beyond the compilation of the geological map of italy scale 1:100.000, one of the main task of the geological survey of italy was to provide geological support to public administrations and the public and private corporate bodies to solve problems related to the stability of the inhabited areas, road constructions, etc. the assistance of the geological survey was asked not only by the ministero dei lavori pubblici, but also by the cassa del mezzogiorno, province administrations, the genio civile etc. it must be underlined that, along the years, the request for the investigations on landslides became more and more frequent, as soon as the public interest moved towards areas not previously urbanized (urbanistic and road expansion, construction of aqueducts, etc.). from this perspective it is easy to understand why, although a. malatesta was not assigned to the applied geology sector, he was requested to give also applied geology consultancies. examining the registers currently in the archive of the department of land defence service of applied geology and hydrogeology, we have drawn several documents from which it results that a. malatesta gave the following consultancies in the years 1950-1965: 1955 on demand of the ministero dei lavori pubblici: study on the landslides in the naso area (messina). demand n°1126 of the 01-03-1955 (fig. 19). 1958 on demand of the catanzaro province: study on the consolidation of the build-up area of the scaglio and canali neighbourhoods (cz). demand n°2812 of the 2312-1958 (fig. 20). 1960 on demand of the genio civile office of avellino: study for the consolidation of the build-up areas of montecalvo and bisaccia (avellino). proposal of perimetrical extension. demand n°8396/10098 of the 24-05-1960 n°440 (figs. 21-24) . 1961 on demand of the genio civile office of sassari: consolidation of the build-up area of esporlato (sassari). demand n°5793 of the 24-04-1961 n°503 (fig. 25). 1961. on demand of the genio civile office of reggio calabria: study on the consolidation of the build-up areas of plaesano feroleto della chiesa (reggio calabria). demand n°2107 of the 20-6-1961 n° 518 (fig. 26). 1961 on demand of the provveditorato opere publiche of cagliari: study of the landslides near esterzilli (cagliari). demand n°8173 of the 12-07-1961 n° 537 (fig. 27). 1961 on demand of the ministero del lavori pubblici: study for the application n°5972 of the 28-08-1961 consolidation of the build-up area of aggius (sassari) n° 543. 1962 on demand of the genio civile office of reggio calabria: study for the consolidation of the build-up areas of campoli and agromastelli near caulonia (reggio calabria). demand n°826 of the 26-2-1962 n° (fig. 28). 5.2 technical-administrative tasks among the many activities carried out by a. malatesta within the geological survey of italy, the following are worth to be mentioned: a) member of the editorial board of the bollettino del servizio geologico d’italia from 1968 (fig. 29); b) member of the italian stratigraphy committee from 1969 (fig. 30); c) following the voluntary resignation of the general manager of the geological survey of italy attilio moretti and before the nomination of alfredo jacobacci, at the end of his career in the geological survey a. malatesta was deputy general manager of the geological survey of italy for a brief period. acknowedgments we wish to thank our friend and colleague gabriella pesci for her support and expertise in the english translation of this paper. references angelelli f. (1992) guida tecnica per la realizzazione di un centro di documentazione geologica del territorio nazionale progetto geodoc le collezioni paleontologiche, 1-20. inedito, servizio geologico nazionale, may 1992, roma. angelelli f. (1995) peculiar sensorimotor characters inferred from an endocranial cast of nesolutra ichnusae malatesta, an endemic pleistocene otter from sardinia. geol. romana, 31, pp.15-20. angelelli f. (2006) il museo virtuale delle collezioni geologiche e storiche di apat: le collezioni paleontologichegiornate di paleontologia 2006 società paleontologica italiana trieste, 8-11/06/ 2006, abstracts, p. 34. alberto malatesta: 20 years of activity at the geological survey of italy 33 fig. 19 a page of the register of applied geology consultancies provided by the servizio geologico d’italia during 1955. in evidence the consultancies carried out by a. malatesta. una pagina del registro delle consulenze di geologia applicata prestate dal servizio geologico d’italia a vari committenti nell’anno 1955. in evidenza quelle prestate da a. malatesta. fig. 20 a page of the register of applied geology consultancies provided by the servizio geologico d’italia during 1958. in evidence the consultancies carried out by a. malatesta. una pagina del registro delle consulenze di geologia applicata prestate dal servizio geologico d’italia a vari committenti nell’anno 1958. in evidenza quelle prestate da a. malatesta. f. angelelli et al. 34 fig.21 a page of the register of applied geology consultancies provided by the servizio geologico d’italia during 1960. in evidence the consultancies carried out by a. malatesta. una pagina del registro delle consulenze di geologia applicata prestate dal servizio geologico d’italia a vari committenti nell’anno 1960. in evidenza quelle prestate da a. malatesta. fig. 22 the telegram sent to the genio civile of avellino by the general manager of the geological survey that communicates the arrival at avellino of a. malatesta. telegramma da parte del direttore del servizio geologico al genio civile di avellino nel quale si comunica data ed ora di arrivo di a. malatesta. fig. 23 folder containing the final geological report on the perimetrical extension of the urbanized area of montecalvo and bisaccia (avellino), written by a. malatesta. cartellina contenente la relazione geologica originale riguardante l’ampliamento perimetrale delle zone urbanizzate di montecalvo e bisaccia (avellino). alberto malatesta: 20 years of activity at the geological survey of italy 35 fig. 24 reimbursment receipt for the avellino trip made by a. malatesta ricevuta del rimborso spese relative alla missione di a. malatesta ad avellino per conto del genio civile. f. angelelli et al. 36 fig. 25 a page of the register of applied geology consultancies provided by the servizio geologico d’italia during 1961. in evidence the consultancies carried out by a. malatesta. una pagina del registro delle consulenze di geologia applicata prestate dal servizio geologico d’italia a vari committenti nell’anno 1961. in evidenza quelle prestate da a. malatesta. fig. 26 a page of the register of applied geology consultancies provided by the servizio geologico d’italia during 1961. in evidence the consultancies carried out by a. malatesta. una pagina del registro delle consulenze di geologia applicata prestate dal servizio geologico d’italia a vari committenti nell’anno 1961. in evidenza quelle prestate da a. malatesta. alberto malatesta: 20 years of activity at the geological survey of italy 37 fig. 27 a page of the register of applied geology consultancies provided by the servizio geologico d’italia during 1961. in evidence the consultancies carried out by a. malatesta. una pagina del registro delle consulenze di geologia applicata prestate dal servizio geologico d’italia a vari committenti nell’anno 1961. in evidenza quelle prestate da a. malatesta. fig. 28 a page of the register of applied geology consultancies provided by the servizio geologico d’italia during 1962. in evidence the consultancy carried out by a. malatesta. una pagina del registro delle consulenze di geologia applicata prestate dal servizio geologico d’italia a vari committenti nell’ anno 1961. in evidenza quella prestata da a. malatesta. f. angelelli et al. 38 angelelli f. (2008) le raccolte storiche di paleontologia conservate all’apat di roma (già del servizio geologico d’italia). programmi di studio e valorizzazione. 14° congresso anms il patrimonio della scienza. le collezioni d’interesse storicotorino 1012/11/2004. museologia scientifica memorie. 2, pp. 77-82. angelelli f. & faramondi s. (2001) il sistema di gestione informatizzata delle collezioni paleontologiche e litomineralogiche del dipartimento per i servizi tecnici. in: angelelli f. (ed.), catalogazione e inventariazione informatizzata dei beni geologici ed ambientali. geoarcheologia, 2, pp. 11-62. angelelli f. & rossi r. (2004) in, angelelli f. (ed.), catalogue of types preserved in “paleontological collections” of apat rome. mem. descr. carta geol. d’it., 65, pp. 1-164. beneo e. (1951) relazione sull’attività annuale del personale del s.g.i. boll. serv. geol. d’it, 73, pp. 399-408. caloi l. & malatesta a. (1974) il cervo pleistocenico in sardegna. mem. ist. it. paleont. um., 2, pp.163-247. compagnoni b., conato v., follieri m. & malatesta a. (1969) il calabriano di scalea. quaternaria, 10, pp. 95-123. conato v., malatesta a. & valletta m. (1967) calabriano ad acrtica islandica sulla costa meridionale d’abruzzo. quaternaria, 9, pp. 261-266. dragone f., maino a., malatesta a. & segre a. g. (1967) note illustrative della carta geologica d’italia f° 149 “cerveteri” alla scala 1:100.000. serv. geol. d’it., pp. 1-93, roma. giordano f. (1881) relazione dell’ispettore capo al comitato geologico. boll. r. com. geol. d’it., 12, pp. 11-24 jacobacci a., bergomi c., centamore e., malatesta a., malferrari n., martelli g., pannunzi l. & zattini n. (1969) note illustrative della carta geologica d’italia f° 115 “ città di castello”, 122 “ perugia”, 130 “ orvieto” alla scala 1:100.000. serv. geol. d’it., pp. 1-151, roma. jacobacci a., malatesta a. & martelli g. (1956) prime notizie sul nuovo rilevamento geologico dei monti peloritani. boll. serv. geol. d’it., 78, pp. 447454. jacobacci a., malatesta a. & motta s. (1961) piano di studi nello stretto di messina per il collegamento della sicilia con la calabria. ricerche geologiche i, pp.166. jacobacci a., malatesta a., martelli g. & stampanoni g. (1967) note illustrative della carta geologica d’italia f° 163 “lucera” alla scala 1:100.000. serv. geol. d’it., pp. 1-48, roma. jacobacci a., malatesta a. & martelli g. (1969) note illustrative della carta geologica d’italia f° 121 “montepulciano” alla scala 1:100.000. serv. geol. d’it., pp. 1-73, roma. lipparini t., malatesta a., nicosia m.l. & valdinucci a. (1955) pliocene e quaternario di capo milazzo in sicilia. boll. serv. geol. d’it., 77, pp. 579-604. malatesta a. (1950) sulla grotta reale di porto azzurro (elba). riv. sc. preist, 5, pp.90-94. malatesta a. (1951) considerazioni sugli ochotonidae fossili e viventi. boll. serv. geol. d’it., 71 (1947-49), pp. 121-146. malatesta a. (1951) osservazioni sull’estensione dei ghiacciai quaternari nella valle di kangra (himalaya esterna). boll. serv. geol. d’it., 73, pp.63-75. malatesta a. (1951) ricerche preistoriche nella valle della lima (lucca). riv. sc. preist., 6, pp. 79 -83. malatesta a. (1952) il calabriano tra castiglioncello e rosignano (livorno). boll. serv. geol. d’it., 73 (1951), pp. 171-184. malatesta a. (1954) alcuni risultati della campagna geologica (1953). boll. serv. geol. d’it., 75 (1953), pp. 724-729. malatesta a. (1954) il cosidetto campanile della nealberto malatesta: 20 years of activity at the geological survey of italy 39 cropoli nuragica di s. andrea priu (bonorva). riv. sci. preist., 9, pp. 105-113. malatesta a. (1954) risultati del rilevamento del f° 192 alghero, sardegna. fossili delle spiagge tirreniane. boll. serv. geol. d’ital, 76, pp. 9-17. malatesta a. (1954) risultati del rilevamento del foglio 192 alghero, sardegna. note di stratigrafia quaternaria, boll. serv. geol. d’it., 75, pp. 371395. malatesta a. (1954) primo dente di elefante fossile rinvenuto in sardegna. quaternaria, 1, pp. 97-105. malatesta a. (1955) faune a cyprina islandica l. tra piazza armerina e mazzarino (sicilia centro-meridionale). boll. serv. geol. d’it., 77, pp. 447-454. malatesta a. (1955) risultati preliminari del rilevamento in sicilia e nelle isole egadi. boll. serv. geol. d’it., 76 (1954), pp. 517-521. malatesta a. (1955) denticulina doderleini d. st. nel pliocene inferiore della sicilia. boll. serv. geol. d’it. 77, pp. 455-460. malatesta a. (1956) conchiglie. il mediterraneo, 1 (3), pp. 1-2. malatesta a. (1957) terreni, faune e industrie quaternarie nell’arcipelago delle egadi. quaternaria, 4, pp. 165190. malatesta a. (1957) on thais (polytropa) lapillus lapillus (linne’) in the pleistocene of sicily. j. palaeont. soc. india, 2, pp. 113-118. malatesta a. (1958) cenni sui risultati delle campagne geologiche effettuate durante l’anno 1956. boll. serv. geol. d’it., 79 (1957), pp. 475-477. malatesta a. (1958) osservazioni sul pliocene e il pleistocene della costa settentrionale della sicilia tra gualtierisicaminò e gioiosa marea. boll. serv. geol. d’it. 79 (1957), pp. 291-326. malatesta a. (1959) notizie preliminari su una fauna del pleistocene siciliano. boll. serv. geol. d’it., 80 (1) (1958), pp. 77-81. malatesta a. (1959) note di geologia e geomorfologia della valle caudina e sulla valle del fiume calore. boll. serv. geol. d’it., 80 (1958), pp. 255-260. malatesta a. (1959) di un livello fossilifero attraversato dalla galleria di bomba nella valle del sangro. boll. serv. geol.d’it., 80 (1958), pp. 261-273. malatesta a. (1960) malacofauna pleistocenica di grammichele (sicilia). parte i. memorie per servire alla descrizione della carta geologica d’italia, 12 (1),1-196. malatesta a. (1962) mediterranean polyplacophora, cenozoic and recent. geologica romana, 1, pp.145-171. malatesta a. (1963) malacofauna pleistocenica di grammichele (sicilia). parte ii. memorie per servire alla descrizione della carta geologica d’italia, 12 (2), pp.199-392. malatesta a. (1964) fossili eocenici del territorio di briga e tenda nelle alpi marittime geologica romana, 3, pp. 65-92. malatesta a. (1964) trias fossilifero a marettimo nelle isole egadi. atti soc. tosc. sci., nat., mem., ser. a, 71, pp. 186-199. malatesta a. (1964) uber einige pleistozane susswassermollusken aus mittel-italien. i. arch. mollusk., 93, pp. 151-162. malatesta a. (1969) conchiglie di mare che si raccolgono in terra. la conchiglia, 1 (1), p. 7, 1 (7), p. 3. malatesta a. (1969) conchiglie di mare che raccolgono a terra un gruppo scomparso di bivalvi: le rudiste. la conchiglia, 1 (3), p. 5. malatesta a. (1970) cynotherium sardous studiati an extinct canid from the pleistocene of sardinia. mem. ist. it. paleont. um., 1, pp. 1-72. malatesta a. (1970) nascita della nomenclatura binomia e della classificazione. la conchiglia, 2 (9), p. 5. malatesta a. (1971) appunti di paleontologia generale. 106 pp. ciclostilate, roma. malatesta a. (1974) malacofauna pliocenica umbra. mem. descr. carta geol. d’it., 13, pp. 1-498. malatesta a. (1977) the skeleton of nesolutra ichnusae sp. n., a quaternary otter discovered in sardinia. geol. romana, 16, pp. 173-209. f. angelelli et al. 40 malatesta a. & martelli g. (1953) sull’origine ed età della porfirite di calabona (alghero). boll. serv. geol. d’it., 74 (1952), pp. 447-456. malatesta a. & motta s. (1956) notizie preliminari di geologia messinese. boll. serv. geol. d’it., 78, pp. 463-466. malatesta a. & nicosia m.l. (1955) i fossili del pliocene e pleistocene di agrigento della collezione lomi. boll. serv. geol. d’it., 77, pp.173-180. malatesta a. & pannuti s. (1957) giacimento preistorico di superficie presso acilia. bull. paletn. ital., n.s., 66, pp. 269-275. malatesta a. & segre a. g. (1955) note illustrative della carta geologica d’italia f° 111 “livorno” alla scala 1:100.000. serv. geol. d’it., pp. 1-30, firenze malatesta a. & segre a. (1956) considerazioni paleontologiche e sistematiche su turris (fusiturris) undatiruga biv. atti soc. tosc. sci. nat., mem., ser. a, 63, pp. 12-32. malatesta a. & settepassi f. (1954) risultati del rilevamento del f° 192 alghero, sardegna. fossili delle formazioni continentali quaternarie. boll. serv. geol. d’it., 76, pp. 33-42. malatesta a., suriano f. (1971) avifauna pleistocenica di alghero (sardegna) boll. serv. geol. d’it. 91 (1970), pp.149-158. malatesta a. & torrente a. (1954) pliocene e pleistocene a caltagirone (sicilia). boll. serv. geol. d’it., 75 (1953), pp. 399-411. malatesta a., perno u. & stampanoni g. (1967) note illustrative della carta geologica d’italia f° 175 “cerignola” alla scala 1:100.000. serv. geol. d’it., pp. 1-38. roma. servizio geologico d’italia (1954) carta geologica d’italia alla scala 100.000 f° 111 “livorno”, roma. servizio geologico d’italia (1955) carta geologica d’italia alla scala 100.000 f° 272 “gela”, roma. servizio geologico d’italia (1959) carta geologica d’italia alla scala 100.000 f° 192” alghero”, roma. servizio geologico d’italia (1959) carta geologica d’italia alla scala 100.000 f° 193” bonorva”, roma. servizio geologico d’italia (1963) carta geologica d’italia alla scala 100.000 f° 163” lucera”, roma. servizio geologico d’italia (1963) carta geologica d’italia alla scala 100.000 f° 175” cerignola”, roma. servizio geologico d’italia (1965) carta geologica d’italia alla scala 100.000 f° 197” amalfi”, roma. servizio geologico d’italia (1967) carta geologica d’italia alla scala 100.000 f° 149” cerveteri”, roma. servizio geologico d’italia (1968) carta geologica d’italia alla scala 100.000 f° 121” montepulciano”, roma. servizio geologico d’italia (1968) carta geologica d’italia alla scala 100.000 f° 122” perugia”, roma servizio geologico d’italia (1968) carta geologica d’italia alla scala 100.000 f° 127” piombino”, roma. servizio geologico d’italia (1968) carta geologica d’italia alla scala 100.000 f° 148”vasto”, roma servizio geologico d’italia (1969) carta geologica d’italia alla scala 100.000 f° 115 “città di castello”, roma. servizio geologico d’italia (1969) carta geologica d’italia alla scala 100.000 f° 173”benevento”, roma. servizio geologico d’italia (1974) carta geologica d’italia alla scala 100.000 f° 167-168 “ isola rossala maddalena”, roma. servizio geologico d’italia (1974) carta geologica d’italia alla scala 100.000 f° 169 “ caprera”, roma. sperandio s. & zanfrà s. (1997) primi programmi per la cartografia geologica d’italia: verbali delle adunanze del regio comitato geologico d’italia negli anni 1868-1877. boll. serv. geol d’it., suppl., 114 (1995), pp. 15. zezi p. (1878) cenno intorno ai lavori del comitato geologico nel 1877. boll. r. com. geol. d’it., 9 (1878), pp. 3-9. ms. ricevuto il 10/07/2010 testo definitivo ricevuto il 18/01/2011 ms. received: july 10, 2010 final text received: january 18, 2011 base late prehistory and environmental changes along the débé river in the lower sourou valley (burkina faso, west africa) alessandro fontana1, paolo mozzi1, aldino bondesan1, armando de guio2, lassinà koté3 1 dipartimento di geografia, università degli studi di padova, padova (italy) 2 dipartimento di archeologia, università degli studi di padova, padova (italy) 3 laboratoire d'archeologié, université de ouagadougou, ouagadougou (burkina faso) corresponding author: a. fontana <alessandro.fontana@unipd.it> abstract: fontana a. et al., late prehistory and environmental changes along the débé river in the lower sourou valley (burkina faso, west africa). (it issn 0394-3356, 2010). about twenty prehistoric sites have been found on the banks of the débé river, a tributary of the souoru river in nw burkina faso, near the boundary with mali. these sites consist of surface scatters of hundreds of flint artefacts and polished stone tools (mainly little adzes), associated with abundant, roughly worked discarded materials, which suggest in situ production. the most investigated area is the site of kourani 5, in which 6 explorative pits were opened; some hand boreholes were realized along the débé and sourou to understand the relationships existing between alluvial evolution and ancient population. the artefacts could be dated to a time range within the ii millennium bc (within a “neolithic”, or “ceramic late stone age”, or “later stone age” phase, according to different authors). a preliminary classification is proposed here on the basis of a number of key reference sequences and known cultural facies from burkina faso and the wider sub-saharan west africa. the débé riverbed is at present occupied by stagnant ponds, seasonally fed by rain water. the sedimentary facies of the channel deposits indicate that it was formerly interested by flowing water inside its 12 m high scarps. this probably happened in the relatively wet, middle holocene climatic setting, before the shift to drier climatic conditions which have affected the whole west africa since the 2nd – 1st millennium bc. during the prehistoric occupation, the flint-bearing layers of the bedrock were outcropping along the river scarps and could be easily quarried. the other raw materials worked in the area, such as quartz and green stones, are not present along the lower stretch of débé and were thus imported. the débé channel was later filled in by silty-clay sediments of colluvial origin, in a semi-arid environment similar to the present one, characterized by increasingly enhanced erosion due to modern anthropic activities. the presence of accessible flint outcrops and the use of exotic raw material support the hypothesis that the sourou valley could have developed an organized territorial system and become part of a medium to long-range exchange network. riassunto: fontana a. et al., preistoria recente e cambiamenti ambientali lungo il fiume débé nella bassa valle del sourou (burkina faso, africa occidentale). (it issn 0394-3356, 2010). durante due missioni geoarcheologiche condotte nel 2007 nel burkina faso nord occidentale, nella pianura del fiume sourou sono stati scoperti circa 20 siti preistorici. le aree archeologiche si trovano lungo il débé, affluente del sourou, tra 15 e 50 km a monte della loro confluenza. i siti corrispondono a concentrazioni di strumenti in pietra scheggiata e levigata (soprattutto accettine e ascette) affioranti lungo le sponde del fiume, sulla superficie della piana. nei siti di maggiori dimensioni, che raggiungono un’estensione di quasi 10 ettari, sono presenti anche migliaia di schegge di sbozzatura e lavorazione. l’area archeologica meglio indagata è quella di kourani 5 (kou5), dove sono state aperte 6 trincee esplorative; per comprendere i rapporti tra depositi alluvionali e dinamica insediativa antica sono stati effettuati alcuni carotaggi stratigrafici fino a 7 m di profondità sia presso questo sito, sia lungo il corso del débé e del sourou. la piatta valle del sourou, che si estende tra il delta interno del fiume niger e la grande ansa del mou-houn (volta nero), è bordata ai lati dal plateau mossi e da quello di bandiagara e corrisponde ad un corridoio ecologico lungo cui avviene la transizione tra la zona sud-saheliana e quella sudanese, con passaggio da condizioni predesertiche ad ambienti di savana arborata. la zona studiata è quindi un settore particolarmente sensibile ai cambiamenti ambientali recenti e passati ed è stata interessata da importanti movimenti di popolazione durante l’olocene recente, probabilmente indotti dalla siccità. nei nuovi siti individuati la presenza di numerose asce e accette in pietra verde, e la loro associazione con microliti semilunati, permette di attribuire genericamente tali complessi litici ad un intervallo temporale compreso nel ii millennio a.c (in una fase del “neolitico”, o “ceramic late stone age”, o “later stone age”, secondo i diversi autori e le diverse terminologie di riferimento). questa corrisponde alla fase olocenica in cui in africa occidentale si diffusero gli strumenti in pietra levigata ed è grossomodo compresa tra 3000 e 800 a.c. viene qui avanzato un primo inquadramento sulla base di sequenze-chiave e facies culturali note del burkina faso e del più vasto contesto dell’africa occidentale sub-sahariana. le informazioni stratigrafiche e geomorfologiche indicano che, durante la frequentazione preistorica, il fiume débé era caratterizzato da portate tali da mantenere l’alveo libero dal sedimento e incassato di circa 2 m rispetto alla pianura circostante. tale assetto consentiva l’affioramento del substrato roccioso lungo le sue sponde, rendendo visibili formazioni marnoso-calcaree contenenti noduli e liste di selce. questa materia prima veniva cavata e lavorata nel sito di kourani 5, dove venivano realizzati anche strumenti in pietra levigata da rocce grezze importate da almeno alcune decine di chilometri di distanza. l’esistenza di numerosi siti di diverse dimensioni, la loro probabile appartenenza alla medesima fase cronologica, la specializzazioni di alcuni di essi nella produzione di strumenti litici induce a ipotizzare l’esistenza di un complesso sistema territoriale che poteva essere parte di circuiti di scambio socio economici di medio ed ampio raggio. la notevole differenza di portate e regime idrologico del débé è probabilmente riconducibile all’inaridimento che ha caratterizzato tutta l’area a sud del sahara a partire dal i millennio a.c. tuttora in corso. questo inaridimento ha causato il riempimento dell’alveo del fiume da parte di colluvi limosi; l’alimentazione di tali depositi è ricollegabile all’erosione areale avvenuta negli ultimi 3 millenni lungo le sponde del fiume per effetto della minor copertura forestale e delle pratiche agro-pastorali. key words: west africa, burkina faso, holocene, prehistory, paleohydrography parole chiave: africa occidentale, burkina faso, olocene, preistoria, paleoidrografia il quaternario italian journal of quaternary sciences 23(2), 2010 199-216 amq abs capraro et al saccom 173-175.pub available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 173 175 the 10be record as a proxy of paleomagnetic reversals and excursions: a mediterranean perspective luca capraro 1, patrizia ferretti 2, patrizia macrì 3, daniele scarponi 4, eliana fornaciari 1, feng xian 5, weijian zhou 5, xianghui kong 5, vanessa boschi 6 1 dipartimento di geoscienze, university of padova, padova, italy 2 cnr-idpa, mestre (venezia), italy 3 istituto nazionale di geofisica e vulcanologia, roma, italy 4 dipartimento di scienze biologiche, geologiche e ambientali, university of bologna, bologna, italy 5 state key laboratory of loess and quaternary geology, institute of earth environment, xi’an, china corresponding author: l. capraro <luca.capraro@unipd.it> abstract: the 10be/9be ratio is acknowledged as an effective tool for establishing the stratigraphic position of paleomagnetic excursions. still, our data suggest that, in particular depositional settings, the interplay between climate, sedimentation and oceanography may jeopardize a realistic depiction of the natural 10be/9be record. keywords: lower/middle pleistocene, central mediterranean, stratigraphy, paleomagnetism, 10be/9be 1. introduction the concentration of 10be atoms adsorbed on sediment particles is measured for tracking major geomagnetic reversals and events, whenever magnetic properties are poor and/or conventional palaeomagnetic analyses yield ambiguous results. this approach relies on both the assumptions that 1) the production rate of 10be in the atmosphere mainly depends on the strength of the earth’s magnetic field, and 2) the 10be generated in the atmosphere is rapidly conveyed to the earth’s surface and locked into sediments. however, the study of marine successions demonstrates that 10be record and palaeomagnetic events are mostly asynchronous (valet et al., 2014). in addition, the period of low intensity of the earth magnetic field associated to geomagnetic reversals, during which an overproduction of cosmogenic 10be is believed to occur, lasts significantly longer than the polarity switch itself (raisbeck et al., 2006). accordingly, there is no independent verification that a given 10be peak marks the exact stratigraphic position of the associated polarity switch, as it may have been generated at any time during the period of intensity low. to our knowledge, the only record reporting on a perfect synchronicity between the 10be and palaeomagnetic signals at the m–b reversal is that of valet et al. (2014), reconstructed in the equatorial indian ocean from a deep–sea sediment core virtually void of terrigenous influxes. in contrast, stratigraphic successions affected by a significant terrigenous input show that the 10be peak lags significantly behind the m–b boundary (e.g., suganuma et al., 2010). according to the interpretation given by suganuma et al. (2010), the 10be peak would point to the correct stratigraphic position (and age) of the reversal, while the geomagnetic signal would be “frozen” at a lower stratigraphic position, well below the sediment surface, in response to lock–in processes. mechanisms that control the flow of cosmogenic 10be particles to the earth surface and, more significantly, their transfer to the seafloor are still ambiguous. we may reasonably assume that the deposition of cosmogenic 10be in ice caps and loess deposits results from the instantaneous “freezing” of the atmospheric signal, although 10be deposition is known to respond to numerous environmental and climatic factors, such as the regional precipitation rates and regimes (e.g., mchargue & damon, 1991; raisbeck et al., 2006). when dealing with marine terrigenous successions, further levels of uncertainty should be added in order to account for the much more complex arrangement of the marine sedimentary system (e.g., brown et al., 1987, 1988; yiou et al., 1988; simon et al., 2017). 2. material and methods we reconstructed a continuous 10be/9be record straddling the m-b reversal for the valle di manche (vdm) section (calabria, southern italy) via the analysis of 68 sedimentary samples collected with an average resolution of ca. 9 cm, which results in a ca. 0.35 kyr resolution according to our age model (capraro et al., 2017). samples were prepared at the university of xi’an, china, according to the procedures reported by zhou et al. (2007), with minor modifications accounting for the difference between loess and marine sediments. beo measurements were performed using the 3-mv accelerator mass spectrometer (ams) at the xi’an ams center, ieecas. test chemistry blank ratios are very small, in the order of 1 ×10-14. https://doi.org/10.26382/aiqua.2018.aiquaconference 3. results our results compare very well with the high– resolution record of 10be and 9be reconstructed for the coeval montalbano jonico (mj) section (basilicata, southern italy; simon et al., 2016), where a conventional palaeomagnetic record of the m-b reversal cannot be achieved (sagnotti et al., 2010). the 9be and 10be concentrations measured at vdm are ca. four times those found at mj. the excess of 9be probably depends on the different primary sources of the terrigenous fraction, these being crystalline rocks from the sila massif at vdm and young sediments from the uplifting apennines at mj. in addition, the estimated sediment accumulation rates are significantly higher at mj, suggesting that, at vdm, the influx of 9be-free material was smaller. probably, the lower sedimentation rates at vdm also account for the higher background concentrations of 10be. at vdm, a prominent 9be spike is centered in correspondence to the “pitagora ash” (capraro et al., 2017), similarly to what documented at mj for the v3 and v4 tephra (simon et al., 2016). most likely, emplacement of the “pitagora ash” provided a massive injection into the water column of highly soluble 9be, which is very abundant in mantle sources (e.g., baroni et al., 2011). 4. discussion and conclusions our record does not provide a complete documentation across the mis 19–mis 18 transition, where 10be concentration attains a relevant peak that correlates almost perfectly to that recognized at mj at ca. 775 ka, which simon et al. (2016) interpret as the geochemical signature of the m-b reversal. this interpretation is at odds with that accomplished at vdm, where the palaeomagnetic record provides unquestionable evidence that the m-b reversal occurs in the midst of full mis 19 (ca. 787 ka according to our age model; macrì et al., 2018). at vdm, 10be concentrations peak ca. 3.5 m above the m-b reversal, i.e. ca. 12 kyr later than the geomagnetic event. this delay is grossly in agreement with that calculated by for many open-ocean records straddling the m–b reversal, where the effects of lock–in processes are invoked (suganuma et al., 2010). however, the high sediment accumulation rates at vdm made the impact of lock-in processes virtually negligible, if any. instead, our results suggest that, in particular settings prone to clastic sedimentation, the m-b reversal may actually predate the deposition of the 10be peak by ca. 10 kyr, possibly in response to the complex dynamics of both climate, ocean circulation and sedimentary system. acknowledgements this research was funded by the university of padova (progetto di ateneo 2010 and dor/ex-60% to l. capraro). references baroni m., bard e., petit j.r., magnan o., bourlès d.l. (2011) volcanic and solar activity, and atmospheric circulation influences on cosmogenic 10be fallout at vostok and concordia (antarctica) over the last 60 years. geochimica et cosmochimica acta, 75, 7132-7145. brown l. (1987) 10be as a tracer of erosion and sediment transport. chemical geology, 65, 189-196. brown l., pavich m.j., hickman r.e., klein j., middleton r. (1988) erosion of the eastern united states observed with 10be. earth surface processes and landforms, 13, 441-457. capraro l., macrì p., scarponi d., rio d. (2015) the lower to middle pleistocene valle di manche section (calabria, southern italy): state of the art and current advances. quaternary international, 383, 36-46. capraro l., ferretti p., macrì p., scarponi d., tateo f., fornaciari e., bellini g., dalan g. (2017) the valle di manche section (calabria, southern italy): a high resolution record of the early-middle pleistocene transition (mis 21-mis 19) in the central mediterranean. quaternary science reviews, 165, 31-48. macrì p., capraro l., ferretti p., scarponi d. (2018) a high-resolution record of the matuyama-brunhes transition from the mediterranean region: the valle di manche section (calabria, southern italy). physics of the earth and planetary interiors, 278, 1-15. mchargue l.r., damon p.e. (1991) the global beryllium 10 cycle. review of geophysics, 29, 141-158. raisbeck g.m., yiou f., cattani o., jouzel j. (2006) 10be evidence for the matuyama–brunhes geomagnetic reversal in the epica dome c ice core. nature, 444, 82-84. sagnotti l., cascella a., ciaranfi n., macrì p., maiorano p., marino m., taddeucci j. (2010) rock magnetism and palaeomagnetism of the montalbano jonico section (italy): evidence for late diagenetic growth of greigite and implications for magnetostratigraphy. geophysics journal international, 180, 1049-1066. simon q., bourlès d.l., bassinot f., nomade s., marino m., ciaranfi n., girone a., maiorano p., thouveny n., choy s., dewilde f., scao v., isguder g., blamart d. (2016) authigenic 10be/9be ratio signature of the matuyama-brunhes boundary in the montalbano jonico marine succession. earth and planetary science letters, 460, 255-267. simon q., thouveny n., bourlès d., nuttin l., hillairemarcel c. (2017) authigenic 10be/9be ratios and 10be-fluxes (230thxs-normalized) in central baffin bay sediments during the last glacial cycle: paleoenvironmental implications. quaternary science reviews, 2016, 140, 142-162. suganuma y., yokoyama y., yamazaki t., kawamura k., chorng-shern h., matsuzaki h. (2010) 10be evidence for delayed acquisition of remanent magnetization in marine sediments: implication for a new age for the matuyama-brunhes boundary. earth and planetary science letters, 296, 443450. valet j.p., bassinot f., bouilloux a., bourlès d., nomade s., guillou v., lopes f., thouveny n., 174 capraro l. et al. dewilde f. (2014) geomagnetic, cosmogenic and climatic changes across the last geomagnetic reversal from equatorial indian ocean sediments. earth and planetary science letters, 397, 67-79. you c.f., lee t., brown l., shen j.j., chen j.c. (1988) 10be study of rapid erosion in taiwan. geochimica et cosmochimica acta, 52, 2687-2691. zhou w.j., lu x.f., wu z.k., zhao w.n., huang c.h., li l.l., cheng p. (2007) new results on xi'anams and sample preparation systems at xi'anams center. nuclear instruments and methods in physics research b, 262, 135-42. 175 the 10be record as a proxy of paleomagnetic reversals and excursions: …. ms. received: may 7, 2018 final text received: may 74, 2018 176 base optical bleaching and dose-response behaviour of al and ti centers in quartz agnese rita zuccarello1, anna maria gueli1, carmelo monaco2, angelo occhipinti1, gloria maria ristuccia1, 2 giuseppe stella1 & sebastiano olindo troja1 1 laboratorio di datazione tramite luminescenza e di metodologie fisiche applicate ai beni culturali del dipartimento di fisica e astronomia, università di catania & infn catania, italy 2 dipartimento di scienze geologiche, università di catania, italy corresponding author: a.r. zuccarello <agnese.zuccarello@ct.infn.it> abstract: zuccarello a. r. et al., optical bleaching and dose-response behaviour of al and ti centers in quartz. (it issn 0394-3356, 2011). electron spin resonance (esr) is one of the most suitable methods for the dating of sedimentary events during the quaternary. however, in some cases, related to the specific samples under examination, esr signals need to be previously analysed for the correct application of the methodology. in this paper, a methodological study for esr dating of geological sediments, by means of aluminium (al) and titanium (ti) centers in quartz, was carried out. in this case, it is necessary to verify the optical bleaching process of esr centers and to study the behaviour of the corresponding signal intensity vs absorbed dose. the maximal bleaching percentage of these centers was evaluated exposing samples to the light from a solar simulator for different times. the results showed, on the one hand, that ti center is totally bleachable, while the al center is characterized by a hard to bleach component, whose evaluation is necessary to correct the esr equivalent dose. on the other hand, in the case of ti-center, the growth curve of esr signal intensity vs dose showed a trend that, for high values, presented strong deviations from that of sse (single saturation exponential), normally used for equivalent dose determination. riassunto: zuccarello a. r. et al., optical bleaching and dose-response behaviour of al and ti centers in quartz. (it issn 03943356, 2011). la risonanza di spin elettronico (esr) è uno dei metodi più adatti per la datazione di eventi sedimentari del quaternario. tuttavia, a seconda della tipologia di campione in esame, è necessaria un’attenta analisi dei segnali esr per la corretta applicazione della metodologia. il lavoro presentato in questa occasione riguarda uno studio metodologico per la datazione di sedimenti geologici da segnali esr dei centri alluminio (al) e titanio (ti) dei cristalli di quarzo. in questo ambito, è necessario verificare l’avvenuto processo di bleaching ottico dei suddetti centri e analizzare l’andamento dell’intensità dei relativi segnali in funzione della dose assorbita. la percentuale massima di bleaching ottico è stata valutata esponendo i campioni alla luce proveniente da un simulatore solare per tempi differenti. i risultati ottenuti hanno mostrato, da un parte, che il centro ti si svuota totalmente e in tempi relativamente veloci, a differenza del centro al caratterizzato da una componente hard to bleach, la cui valutazione si rende indispensabile per la correzione della dose equivalente esr. d’altra parte, nel caso del centro ti, la curva di crescita del segnale esr in funzione della dose ha evidenziato un andamento che, ad alte dosi, si discosta da quello descritto matematicamente dalla funzione sse (single saturation exponential), normalmente utilizzata per la determinazione della dose equivalente. keywords: sediments, dating, esr parole chiave: sedimenti, datazione, esr il quaternario italian journal of quaternary sciences 23(2), 2010 251-256 1 introduction since the first successful experiment performed by zavoisky (1945), electron spin resonance (esr) has been applied to many fields of chemistry, physics, biology and geology. the interest in archaeological and geological esr dating began after the pioneering work of ikeya (1975) on a stalactite from akiyoshi cave in japan. since then, it has been applied to many materials and further studies have been made to improve the method. the most important dating applications concern minerals which are precipitated or biogenically secreted, such as carbonates in speleothems, mollusc shells, corals, …, or hydroxyapatite in tooth enamel, as well as materials which were heated in the past, such as volcanic minerals, and optically bleached (signal resetting by light exposure) (ikeya, 1993). in this last field, esr dating has been widely used to date sediments using signals from quartz inclusions as it contains several paramagnetic centers (yokoyama et al., 1985; tanaka et al., 1997; voinchet et al., 2003; 2004; tissoux et al., 2007; 2008; rink et al., 2007). in this case, quartz is used as a dosimeter accumulating dose as a result of ionising radiation in the environment or inside the crystal. the assumption is that radiation-induced signals in quartz crystals are reduced or zeroed by daylight exposure during transportation and sedimentation, and then regrow during the burial of quartz in sediments due to exposure to natural radiation. the total absorbed dose (the equivalent dose de) is obtained by the additive dose method and converted to an esr age by assessing the annual dose rate (ikeya, 1993). esr shares with osl (optically stimulated luminescence), the most common dating method for sediments, both the object of the measurements, quartz crystals, and the mechanism for zeroing of the centers connected to sunlight exposure. nevertheless, esr dating has a larger time range with respect to osl (not more than some hundreds of thousands of years). rink et al. (2007) showed, in fact, that esr yields agreement with independent age control up to about 2.5 ma, extending the range dating of optically exposed quartz in sediments by a factor of about 5: this places it among the most suitable methods for the quaternary period. 252 a.r. zuccarello et al. however, for the optimal application of the technique, it is important to know the optical bleaching behaviour of the esr dating signals. the aluminium (al) and titanium (ti) related impurity defects are usually used to date quartz grains by esr method. they are measured at cryogenic temperatures (77 k), differing from other paramagnetic centers typical of materials cited above. bleaching experiments showed that al-center has two components, one bleachable and the other non-bleachable (yokoyama et al., 1985; laurent et al., 1998; voinchet et al., 2003; 2004; 2007). thus, the presence of this last component must be taken into account in order to determine the real total dose absorbed by samples since their burial after the bleaching process. similar experiments on ti-center have shown that it can be fully zeroed (tanaka et al., 1997; toyoda et al., 2000; rink et al., 2007; tissoux et al., 2007; gao et al., 2009). in the present work we used the ti-li center because the two other types of ti signals (ti-h and ti-na) were not detected above the background in samples under examination. in this report we tested the effect of the al nonbleachable component and, following the additive dose protocol, artificial gamma irradiations were made in order to verify the degree of the eventual correction and to analyse the trend of al and ti-li signals vs dose. 2 experimental 2.1 sample preparation and irradiation sedimentary quartz samples from marine terraces of the south of italy were used for the study. the samples preparation was carried out under controlled lighting with our laboratory standard protocol (adapted from wintle, 1997 and cited references; aitken, 1998) to provide a 100-200 µm quartz fraction. each sample was treated with 10% hcl for 1h to remove carbonates, 35% h2o2 for at least one day to remove organic material, followed by washing with distilled water and drying. sodium polytungstate was used to separate the quartz from the feldspars and other silicate minerals. then, samples were etched by 40% hf for 45 min to remove the outer part of the quartz grains that was affected by alpha irradiation and fluorides were eliminated using 10% hcl for 10 min. finally, quartz grains were rinsed with distilled water and dried. artificial irradiation was performed using a 60co calibrated source at the ente per le nuove tecnologie, l'energia e l'ambiente (casaccia, rome). additional doses up to 25000 gy were given. 2.2 bleaching experiments optical bleaching experiments were performed to evaluate the behaviour of the esr intensity under sunlight exposure. the quartz samples were divided into seven aliquots of about 100 mg. each aliquot was then put in a stainless steel dish, where grains were spread out as a thin layer on a surface of 2.5 cm in diameter. the dishes were placed on a copper plate with a water cooling system. quartz grains were bleached using a 150 w ozone free xenon lamp (66002 oriel solar simulator) for different exposure times. the air mass filters a.m.0+a.m.1 were used to simulate solar spectrum at ground level when the sun is directly overhead. the illuminance was about 105 lux and the samples were continuously exposed from 0 to 400 h. 2.3 esr measurements and de calculation esr measurements were carried out on a jeol fa-100 x-band spectrometer in a finger dewar cooled to 77 k by liquid nitrogen, using microwave power of 5 mw and modulation amplitude 0.16 mt. the al-center intensity (see 1 in fig. 1) was measured from the top of the first peak to the bottom of the last peak of the part of the main hyperfine structure (yokoyama et al., 1985), while the ti-li intensity (see 2 in fig. 1) was evaluated from the bottom of the peak at g = 1.913 to the baseline (toyoda et al., 2000). esr intensities were normalized by the aliquots weights. a single saturating exponential (sse) function was fitted to the experimental data points in order to get de value (apers et al., 1981): i(d) = is (1 e (d+de) / ds ) where i(d) is the measured esr signal intensity, d the laboratory added dose, is the esr saturation level and ds the characteristic saturating dose. de value was calculated by extrapolating the sse function to the zero ordinate, considering only the first steps of irradiation. for the al-center, this value is comprehensive of the residual dose dr due to a non-bleachable component, evaluable from the bleaching response to the solar simulator light. therefore, the corrected equivalent dose de is determined by subtracting dr from the total dose. for the ti-center the de value was obtained directly by additive dose method, assuming that complete optical bleaching of the associated esr signal has occurred in the sedimentation phase. 3 results and discussion all the samples analysed exhibit esr signals of al and ti-li centers, as shown in figure 1 where a typical spectrum of a natural sample is reported. figure 1 esr signals of al and ti-li centers observed at 77 k for natural quartz grains extracted from marine terrace sediments. segnali esr dei centri al e ti-li di quarzo estratto da terrazzi marini osservati a 77 k. bleaching experiments showed that esr intensity decreased with illumination time, even if with a different decay-rate for the two al and ti-li centers. an example of experimental ti-li intensity decay of natural samples is plotted in figure 2a. it can be observed that, in a time less than 200h, it is totally erased. for this reason, the equivalent dose de was calculated directly by the additive dose method applied to ti-li signal, without any subtraction of residual dose (fig. 2b). for the al-center, the intensity reduced and then reached a plateau representing the residual intensity linked to the non-bleachable component by sunlight exposure. in this case, the data were fitted (fig. 3 on the left) using the exponential function, proposed by walther and zilles (1994): y = ae(-bx) i0 , in which x is the exposure time to the sunlight, y is the measured esr intensity, a and b are the parameters of the fit and i0 the residual intensity. from this last value and from natural esr signal intensity inat, it is possible to calculate the maximal bleaching percentage that, using the formula inat i0 bl(%) = ––––––– x 100, was between 20% and 30% for inat samples analysed. for this reason, the equivalent dose evaluated from al center was corrected for the presence of the residual level equal to that obtained in the laboratory bleaching, following the procedure described in voinchet et al. (2004). in this way, only the bleachable component of the al-center was taken into account (fig. 3). from the point of view of optical bleaching experiments, it can be observed that the use of ti-li center could be more practical, above all when it and ti-h and ti-na signals (when observed) give concordant de values, as reported in toyoda et al. (2000). however, it is important to consider also the expected equivalent dose of samples under examination and assuring that the esr center used for its determination is not saturated. with this aim, we irradiated the samples up to 25000 gy and the results from esr measurements are reported in figure 4. in the case of the al center (fig. 4a), we observed a rising in the dose-response curve, suggesting the possibility to determine higher de than those here reported, as also suggested by rink et al. (2007). the different approach for ti-li center (fig. 4b) that already saturated for doses of some thousands of 253optical bleaching and dose-response ... figure 2 – example of optical response of the ti-li center to the solar simulator light exposure (a) and growth curve of the same signal vs dose (b). esempio di curva di decadimento del centro ti-li in funzione del tempo di esposizione alla luce proveniente dal simulatore solare (a) e curva di crescita dello stesso segnale in funzione della dose (b). figure 3 – example of optical response of the al-center to the solar simulator light exposure (on the left) and of growth curve of al intensity vs dose (on the right), together with the procedure described in voinchet et al. (2004) for the determination of the corrected de, calculated only from the bleachable component. esempio di andamento del segnale del centro al in funzione del tempo di esposizione alla luce proveniente dal simulatore solare (a sinistra) e di curva di crescita dello stesso in funzione della dose (a destra), nonché della procedura descritta in voinchet et al. (2004) per la determinazione della de corretta, calcolata solo dalla componente otticamente svuotabile. 2a) 2b) 254 gy, as also observed in tissoux et al. (2007). at this state, the trend of the experimental data allows the use of the lower first steps of irradiation as sse function does not fit them for the presence of a knee region not followed by saturation. 4 conclusions for the dating of sediments, it is very important to evaluate the optical bleaching behaviour of the signal being used for dating. the al and ti-li signals of samples from marine terrace sediments were observed and their response to sunlight exposure was investigated. this confirmed the need for using only the bleachable portion of al-center while no correction was necessary in the case of ti-li signal. on the other hand, the methodological study at doses up to 25000 gy led to some observations. in particular, al signal dose response-curve presented a trend well described by sse function, while for ti-li center further measurements and phenomenological models are necessary to better understand the behaviour of the experimental data. in fact, anomalous behaviours of the esr signals may influence the age determinations. acknowledgements we wish to thank nunzio giudice, nunzio guardone, mario mazzeo, antonio rapicavoli and vito sparti for technical assistance. references aitken m.j. (1998) an introduction to optical dating – oxford university press, oxford. apers d.j., debuyst r., de canniere p., dejehet f. & lombard e. (1981) a criticism of dating by electron paramagnetic resonance (esr) of the stalagmitic floors of the caune de l’arago at tautavel proc. absolute dating isotope anal. prehistory meth. limits, 553-550. gao l., yin g.m., liu c.r., bahain j.j., lin m. & li j.p. (2009) natural sunlight bleaching of the esr titanium center in quartz – radiat. meas., 44, 501504. ikeya m. (1975) dating a stalactite by electron paramagnetic resonance – nature, 255, 48-50. ikeya m. (1993) new applications of electron spin resonance: dating, dosimetry and microscopy – world scientific, singapore. laurent m., falguères c., bahain j.j., rousseau l. & van vliet lanoé b. (1998) esr dating of quartz extracted from quaternary and neogene sediments: method, potential and actual limits – quat. geochronol., 17, 1057-1062. rink w.j., bartoll j., schwarcz h.p., shane p. & baryosef o. (2007) testing the reliability of esr dating of optically exposed buried quartz – radiat. meas., 42, 1618-1626. tanaka t., hataya r., spooner n.a., questiaux d.g., saito y. & hashimoto t. (1997) dating of marine terrace sediments by esr, tl and osl methods and their applicabilities – quat. sci. rev., 16, 257264. tissoux h., falguères c., voinchet p., toyoda s., bahain j.j. & despriée j. (2007) potential use of ti center in esr dating of fluvial sediments – quat. geochronol., 2, 367-372. tissoux h., toyoda s., falguères c., voinchet p., takada m., bahain j.j. & despriée j. (2008) esr dating of sedimentary quartz from two pleistocene deposits using al and ti-centers – geochronometria, 30, 23-31. toyoda s., voinchet p., falguères c., dolo j.m. & laurent m. (2000) bleaching of esr signals by the sunlight: a laboratory experiment for establishing the esr dating of sediments – appl. radiat. isot., 52, 1357-1362. yokoyama y., falguères c. & quaegebeur j.p. (1985) esr dating of quartz from quaternary sediments: first attempt – nucl. tracks, 10, 921-928. figure 4 example of growth curve of esr intensity of al (a) and ti-li (b) signals for γ irradiated aliquots up to 25000 gy. esempio di curva di crescita dell’intensità dei segnali al (a) e ti-li (b) su aliquote irraggiate tramite sorgente gamma con valori di dose fino a 25000 gy. a.r. zuccarello et al. 4a) 4b) 255 voinchet p., falguères c., laurent m., toyoda s., bahain j.j. & dolo j.m. (2003) artificial optical bleaching of the aluminium center in quartz implications to esr dating of sediments – quat. sci. rev., 22, 1335-1338. voinchet p., bahain j.j., falguères c., laurent m., dolo j.m., despriée j., gageonnet r. & chaussé c. (2004) esr dating of quartz extracted from quaternary sediments: application to fluvial terraces systems of northern france – quaternaire, 15, 135-141. voinchet p., falguères c., tissoux h., bahain j.j., despriée j. & pirouelle f. (2007) esr dating of fluvial quartz: estimate of the minimal distance transport required for getting a mawimum optical bleaching – quat. geochronol., 2, 363-366. walther r. & zilles d. (1994) esr studies on bleached sedimentary quartz – quat. geochronol., 13, 611-614. wintle a.g. (1997) luminescence dating: laboratory procedures and protocols radiat. meas., 27, 769-817. zavoisky e. (1945) spin-magnetic resonance in paramagnetics – j. phys., 9, 245-249. ms. ricevuto il 22 giugno 2010 testo definitivo ricevuto il 29 ottobre 2010 ms. received: june 22, 2010 final text received: october 29, 2010 optical bleaching and dose-response ... evoluzione morfotettonica quaternaria del bacino intermontano di sanza (appennino meridionale) paola di leo1, salvatore ivo giano2, dario gioia2, massimo mattei3, eva pescatore4 & marcello schiattarella2 1cnr-imaa, tito scalo (pz) 2dipartimento di scienze geologiche, università della basilicata, potenza (ivo.giano@unibas.it) 3dipartimento di scienze geologiche, università di roma tre 4dipartimento di scienze della terra, università di napoli “federico ii riassunto: di leo p., et al., evoluzione morfotettonica quaternaria del bacino intermontano di sanza (appennino meridionale). (it issn 0394-3356, 2009) la conca intermontana drenata dall’alto corso del fiume bussento (“bacino di sanza” auctt.), allungata in direzione e-o, è delimitata a nord dai carbonati mesozoici del monte cervati e a sud dalle successioni silicoclastiche e marnoso-calcaree cretacico-terziarie del monte centaurino e dai calcari cretacici del monte forcella. il corridoio morfologico del bacino di sanza rappresenta fisiograficamente un braccio del contiguo vallo di diano, di cui tuttavia non è tributario, colmato da una successione continentale conglomeratico-argillosa interessata da diverse famiglie di faglie e fratture. lo studio morfostratigrafico e l’analisi delle associazioni di facies del riempimento clastico hanno permesso di differenziare i diversi ambienti deposizionali continentali e di correlare i depositi di sanza con quelli del riempimento quaternario del vallo di diano, entro cui sono stati peraltro riconosciuti e datati due livelli vulcanoclastici. il bacino fluvio-lacustre pleistocenico si estingue per erosione della soglia meridionale e successiva reincisione ad opera della rete idrografica. la diffrattometria, la spettroscopia ir e la termogravimetria hanno mostrato per i depositi pelitici di sanza una composizione mineralogica costituita, in ordine di abbondanza, da illite e strati misti illite/smectite, caolinite/halloysite, vermiculite/clorite, quarzo, goethite/ematite e, in alcuni campioni, feldspati (sino al 5% in peso). il riconoscimento di halloysite 7å con habitus sferoidale, soprattutto nella frazione ultrafine (< 0,2 µm), e di cristalli di k-feldspato suggerisce la presenza di una componente vulcanoclastica. l’halloysite formatasi per alterazione del vetro vulcanico e pomice assume infatti una forma sferoidale o talvolta tubolare di piccole dimensioni, a differenza di quella originatasi dall’alterazione di feldspati in rocce granitiche, che assume una tipica forma tubolare. anche il diagramma zr/tio2 vs (v+ni+cr)/al2o3 mostra un i n p u t vulcanoclastico significativo, attribuibile all'attività vulcanica del roccamonfina. i marker morfotettonici (superfici di spianamento, versanti di faglia e di linea di faglia, ecc.) e l’assetto delle principali morfostrutture positive e negative dell’area sono alcuni degli elementi utilizzati per lo studio dell'evoluzione a lungo termine del rilievo locale. le indagini morfostrutturali e l’analisi del sistema di fratture e delle famiglie di faglie alla mesoscala nei carbonati mesozoici ai bordi del bacino e nei depositi continentali quaternari hanno permesso di riconoscere le direttrici tettoniche responsabili della formazione della depressione, mentre l'analisi dell'anisotropia della suscettività magnetica (ams) condotta su brecce di versante antiche e silt lacustri ha permesso di determinare le direzioni degli assi dell'ellissoide di suscettività magnetica, che indicano una variazione del campo di stress locale nel corso del pleistocene inferiore e medio compatibile con quella documentata a scala regionale. i dati ottenuti con le diverse metodologie hanno consentito di definire la cinematica di apertura del bacino e di ricavare un quadro esaustivo circa l’età, il contesto tettono-sedimentario, geomorfologico e paleoclimatico entro cui è stata generata e si è evoluta la depressione morfostrutturale di sanza, anche in relazione alla complessa storia morfoevolutiva del vicino vallo di diano. abstract: di leo p., et al., quaternary morphotectonic evolution of the sanza intermontane basin (southern apennines, italy. (it issn 0394-3356, 2009). opening kinematics and morphotectonic evolution of the sanza catchment, a quaternary basin of the southern apennines axial zone, have been studied. besides geomorphological classical analyses, an interdisciplinary approach has been used here joining structural analysis of brittle deformation, mineralogical and chemical analyses of paleosoils and sediments, anisotropy of magnetic susceptibility (ams), and tephra radiometric dating. several pleistocene morpho-sequences have been outlined, also comparing them with a wider scenario on a regional scale. the sanza basin is hosted in an e-w trending narrow lacustrine trough. this morpho-structural low is a lateral branch of the wider vallo di diano basin, characterized by a multi-stage morphotectonic evolution. red clays and associated palaeosols from the sanza basin have been studied from a geomorphological viewpoint and mineralogical and chemical characteristics have been analyzed to set the palaeoclimate and palaeoenvironmental conditions during middle to late pleistocene time-span. the pleistocene morpho-sequence of the study area has been outlined, also comparing the stratigraphic succession of the sanza basin with those from the adjacent vallo di diano basin, mainly on the grounds of tephra radiometric dating. survey and mapping of remnants of land surfaces, organized in six altimetric classes, permitted us to reconstruct the pleistocene geomorphological evolution of the relief. using the surface at the top of the sanza deposits as a reference marker with regard to the other orders of terraced surfaces, it has been possible to include the genesis and evolution of the basin in a larger time-span and to relate its structural history with regional and local tectonic episodes. in particular, the e-w trending trough was generated in a tectonically-controlled narrow transversal strip due to the activity of a transfer zone of the chain. the changing tectonic regime was responsible for the endorheic conditions reached by the depression during mid-pleistocene times. in such a basin, lacustrine red clays and fan conglomerates were deposited. to the top, weathered horizons and palaeosols with interbedded tephra have been recognized and analysed. the mineralogy and geochemistry of 14 pelitic sediments allowed us to delineate the climate condition which characterized the sedimentation in this basin. the clay minerals association observed in the analyzed sediments, mainly constituted by illite/smectite chlorite/smectite mixed layers, vermiculite, kaolinite+halloysite and goethite+hematite, coupled to high values of cia (chemical index of alteration; values > 85), are compatible with an high degree of weathering. the increase of mineral phases such as kaolinite, goethite and hematite and decrease of clay minerals abundances such as vermiculite and illite/smectite chlorite/smectite mixed layers in the younger sediments (late pleistocene) with respect to the older ones (middle pleistocene) are indicative of a palaeoclimate scenario characterized by temperate conditions with dry-wet periods which evolves toward warm and humid conditions. the presence of 7å halloysite exhibiting mainly a spheroidal habitus and a large amount (up to 5%) of feldspars are indicative of the presence of a volcanoclastic input in the sanza basin. major/trace element ratio relationships and multivariate statistical analysis (principal component analysis method) of geochemical variables strongly support the presence of the volcanoclastic input. il quaternario italian journal of quaternary sciences 22(2), 2009 189-206 190 p. di leo et al. 1. introduzione i bacini intermontani di origine tettonica presenti nella fascia assiale della catena sud-appenninica rappresentano una preziosa fonte di dati per la comprensione dell’evoluzione quaternaria dell’appennino meridionale. la letteratura sul regime tettonico responsabile della loro nascita, sugli aspetti stratigrafico-deposizionali delle successioni clastiche continentali, sull’evoluzione geomorfologica e, sulla successiva estinzione della maggior parte di essi è ormai vasta (santangelo, 1991, sc h i a t t a r e l l a et al., 2003, gi a n o & ma r t i n o, 2003, martino & schiattarella, 2006, per il bacino del melandro; di niro et al., 1992, di niro & giano, 1995, giano et al., 1997, giano et al., 2000, schiattarella et a l., 2003, bo e n z i et al., 2004, per l’alta val d’agri; sa n t a n g e l o, 1991, as c i o n e et al., 1992, ka r n e r et al. , 1999, per il vallo di diano; sc h i a t t a r e l l a et al., 1994, sc h i a t t a r e l l a, 1996, ma r r a, 1998, gi o i a & sc h i a t t ar e l l a, 2006, per il bacino del mercure e il valico di prestieri; la rocca & santangelo, 1991, per la valle del noce). in anni più recenti la ricerca morfotettonica ha riguardato soprattutto la quantificazione dei processi e la contestualizzazione regionale, sia in chiave geodinamica che paleoclimatica. in tale quadro è stato condotto lo studio del bacino intermontano compreso tra i rilievi silentini del monte cervati e del monte centaurino (“bacino di sanza“ di li p p m a n n pr o v a n s a l, 1987), che ospita l’alto corso del fiume bussento. si tratta di una depressione tettonica orientata in direzione e-o e che pertanto forma un angolo di circa 70° rispetto all’andamento appenninico del contiguo vallo di diano. il bacino è colmato da una successione continentale conglomeratico-argillosa pleistocenica, i cui caratteri di facies e composizionali sono stati indagati in dettaglio solo recentemente (di leo et al., 2008). le numerose indagini condotte nella depressione che ospita il bacino di sanza hanno riguardato vari aspetti tematici, da quelli più tipicamente legati alla geologia di campo, morfostrutturali, mesostrutturali e stratigrafici, a quelli più “specialistici” come le analisi chimico-mineralogiche di sedimenti, orizzonti di alterazione e paleosuoli, la determinazione dei caratteri dell’anisotropia della suscettività magnetica (ams) dei depositi e dell’età radiometrica di alcuni m a r k e r s t r a t igrafici riconosciuti nei depositi fluvio-lacustri del vallo di diano. l’integrazione dei dati ha consentito di definire la cinematica di apertura del bacino, di ottenere vincoli cronologici riguardo alla sua età e di chiarire il contesto tettono-sedimentario, geomorfologico e paleoclimatico entro cui è stato generato e si è sviluppato il bacino di sanza. i dati ottenuti sono stati confrontati e discussi sia con quelli relativi alla storia evolutiva del vicino vallo di diano e sia con quelli riguardanti il contesto geologico regionale. 2. breve inquadramento geografico e geologico il bacino intermontano di sanza è ubicato nella zona assiale della catena sud-appenninica, ospitato in uno stretto corridoio morfologico che termina, verso e, all’apice meridionale del vallo di diano. è confinato a nord dalle assise carbonatiche mesozoiche del monte cervati e a sud dalle dorsali del monte forcella e del monte centaurino, costituite rispettivamente da calcari cretacici e da successioni silicoclastiche e marnosocalcaree cretacico-terziarie. la conca è drenata dall’alto corso del fiume bussento che sfocia nel mar tirreno, mentre un esile spartiacque la separa dal bacino idrografico del vallo di diano drenato dal fiume tanagro. le principali unità tettoniche dell’appennino meridionale affioranti nell’area di studio (fig. 1) – e più in generale nella regione silentina – sono riconducibili alle successioni pelagiche di provenienza interna (unità nord-calabrese, s e n s u bo n a r d i et al., 1988; unità silentina di base, ma u r o & sc h i a t t a r e l l a, 1988; unità di castelnuovo cilento, ca m m a r o s a n o et al., 2000, 2004; unità sicilide, og n i b e n, 1969), sormontate in discordanza dai depositi del gruppo del cilento (amore et al., 1988), e alle unità della piattaforma campanolucana (d’argenio et al., 1973). i carbonati di mare basso – che costituiscono il substrato geologico di gran parte dell’area di studio – sono rappresentati in cilento prevalentemente dall’unità alburno-cervati-pollino, costituita da una potente successione mesozoica compresa tra il triassico superiore ed il cretaceo superiore, su cui giace in concordanza, marcando un’ampia lacuna stratigraf ica, la formazione di trentinara del paleocene–eocene, alla quale segue verso l’alto, con l’interposizione di sacche e lenti di argille residuali, la formazione di cerchiara del miocene inferiore. su questa poggiano in discontinuità stratigrafica la formazione del bifurto del miocene inferiore-medio e le calciruditi ed arenarie di piaggine del miocene superiore. il fondovalle del bacino di sanza è colmato da una successione clastica continentale, incisa e terrazmineralogical and geochemical comparison of the samples with altered middle pleistocene volcanic products from the first cooling unit of the roccamonfina volcanic complex (630-385 ka, roccamonfina supersynthem), used as an indirect dating, allowed us to temporally confine the fluvial-lacustrine sanza succession. moreover, 40ar/39ar radiometric dating of sanidine crystals from tephra layers interbedded into the nearby vallo di diano lacustrine succession correlated to the fluvio-lacustrine sanza succession allows us to chronologically constrain the top and the bottom of the sanza succession (706.3±8.1 ka e 106.7±1.6 ka). the sanza basin can be assimilated to a morphostructural trough coinciding with a long-term transfer zone of the chain, in which a severe change in stress field, uplift rate, climate conditions, and relief production occurred during pleistocene times. in particular, it can be stated that the study area underwent a climate shift from temperate to warm/humid conditions. furthermore, the fluvio-lacustrine sanza succession age is univocally set to the middle-late pleistocene. parole chiave: geomorfologia tettonica, geologia del quaternario, bacini intermontani fluvio-lacustri, appennino meridionale (italia). keywords: tectonic geomorphology, quaternary geology, fluvio-lacustrine basin, southern apennines (italy). zata dal fiume bussento e dai suoi affluenti. le associazioni di facies sono relative a depositi fluvio-lacustri, che presentano spessori di alcune decine di metri. 3. depositi quaternari: implicazioni cronostratigrafiche e vincoli geocronologici 3.1. precedenti conoscenze una prima descrizione dei caratteri litostratigrafici dei depositi continentali del bacino di sanza si deve a li p p m a n npr o v a n s a l (1987), che riconosce alla base della successione brecce di versante antiche a cui seguono verso l’alto terreni in facies di conoide alluvionale che formano ampi glaçis d’erosione di età wurmiana, incisi e terrazzati dalla rete idrografica. l’autore colloca cronologicamente, in base a considerazioni geomorfologiche, l’evoluzione del bacino tra il pleistocene inferiore ed il würm. secondo sa n t a n g e l o (1991) la soglia morfologica che separa il bacino di sanza dal vallo di diano, e la deviazione del torrente peglio (che drena verso la depressione del vallo di diano) sarebbero state generate da un evento tettonico collocato nella parte medio-alta del pleistocene inferiore. l’autore ritiene, associando l’evoluzione geomorfologica e sedimentaria del bacino di sanza a quella del vicino vallo di diano, che i depositi delle due depressioni siano coevi; 191evoluzione morfotettonica quaternaria del bacino intermontano ... in particolare, i depositi di sanza vengono correlati a quelli del i ciclo lacustre del vallo di diano affioranti tra buonabitacolo e montesano sulla marcellana, che nella parte alta, hanno fornito un’età radiometrica compresa tra 0.6±0.2 ma e 0.7±0.2 ma. secondo l’autore nel vallo di diano, poco dopo l’inizio del pleistocene medio (a circa 0.6 ma), una fase tettonica disloca le argille del i ciclo e innesca l’incisione verticale della rete drenante all’apice meridionale del vallo, mentre nella porzione centrale del bacino inizia la sedimentazione dei depositi del ii ciclo lacustre, in discordanza su quelli del i ciclo. 3.2. stratigrafia dei depositi e correlazioni morfostratigrafiche il rilevamento delle successioni continentali quaternarie ha permesso di riconoscere l’esistenza, in alcune zone del fondovalle e a letto del riempimento clastico del bacino, di un deposito conglomeratico massivo a composizione prevalentemente arenacea attribuibile alla formazione dei conglomerati di centola (gu i d a e t al., 1979). nella fascia pedemontana del bacino affiorano due generazioni di brecce di versante in assetto stratoide formate da clasti carbonatici immersi in matrice sabbiosa di colore rosso o marrone. nei valloni caccialupi e inferno le brecce sono dislocate e ruotate contromonte di circa 30° dalla faglia del bordo settentrionale del bacino, orientata e-o (linea di sanza, secondo di le o et al., 2008), come già osservato da lippmann pr o v a n s a l (1987) che assegna le brecce ad un generico pleistocene inferiore. un deposito detritico più recente, non deformato e litologicamente simile al precedente, ricopre in alcune aree quello più antico. i conglomerati della formazione di centola e il deposito detritico appaiono entrambi ricoperti in contatto erosivo dai depositi del riempimento clastico del bacino di sanza (di leo et al., 2008). la successione di spessore variabile da pochi metri a poco oltre 30 m, è formata dal basso verso l’alto da conglomerati calcarei eterometrici, a supporto clastico o con rara matrice sabbiosa (conglomerati basali in fig. 2), di spessore variabile fino a circa 15 m che, con un contatto erosivo, talora marcato da paleosuoli rossi, passano a conglomerati in assetto stratoide formati da clasti carbonatici subarrotondati ed eterometrici, a supporto di matrice argillosa e sabbiosa rossastra (c o n g l o m erati sommitali in fig. 2) che non superano gli 8 m di spessore. entrambi i depositi sono riconducibili ad ambienti di conoide alluvionale. i conglomerati a matrice rossa passano in eteropia latero-verticale a un deposifig. 1 – schema geologico dell’area di studio. legenda: 1) unità interne (eocene medio – miocene superiore); 2) unità alburno-cervati-pollino: successioni di piattaforma carbonatica (triassico – eocene); 3) unità alburno-cervati-pollino: depositi silicoclastici (miocene mediosuperiore); 4) unità dei monti della maddalena (triassico superiore – miocene superiore); 5) unità lagonegresi (triassico inferiore-medio – paleogene); 6) depositi plio-quaternari; 7) contatto tettonico; 8) limite stratigrafico. geological sketch map of the study area. legend: 1) middle eocene to upper miocene “internal” units; 2) triassic to eocene shallow-water carbonates of the alburno-cervati-pollino unit; 3) middle to upper miocene syntectonic deposits of the alburno-cervati-pollino unit; 4) upper triassic to upper miocene shallow-water carbonates of the monti della maddalena unit; 5) early-middle triassic to paleogene deep-sea sediments of the lagonegro units; 6) pliocene to quaternary clastics; 7) tectonic contact; 8) stratigraphic boundary. 192 to siltoso e argilloso di colore rosso o, a luoghi, giallo ocra, sedimentato in un ambiente a bassa energia di tipo lacustre (argille di sanza in fig. 2) che arriva fino a circa 10 m di spessore. in prossimità dei rilievi carbonatici la base delle peliti lacustri presenta lenti o livelli centimetrici discontinui di silt argilloso nero, di ambiente palustre, o poggia direttamente sui calcari mesozoici colmando cavità da dissoluzione carsica ben sviluppate. la successione studiata è parzialmente correlabile ai depositi del sintema del bussento riportato nella carta geologica regionale in scala 1:25.000, sanza 504 se (aa.vv., 2008). il riempimento continentale della conca intermontana di sanza, che raggiunge complessivamente poco più di 30 m di spessore, è stato prodotto in un ambiente deposizionale fluvio-lacustre (fig. 3). la sequenza verticale di tipo log-normale (fu) termina a tetto con sedimenti pelitici; nel vallone caccialupi il top deposizionale della successione è morfologicamente incastrato nelle brecce antiche infrapleistoceniche, sospese di alcune decine di metri e quindi in termini (morfo)stratigrafici i conglomerati e le argille di sanza sono più recenti delle brecce (cfr. fig. 2). sulla successione fluvio-lacustre poggiano in contatto erosivo silt e sabbie giallo-oro con elementi vulcanoclastici che riempiono canali profondi fino a 2 metri, incisi nelle peliti rosse lacustri (argille di sanza) . un livello vulcanoclastico talora alterato, di colore giallo-marrone, con spessori variabili da 50 cm ad 1 m, affiora in diversi punti del bacino sia sul silt giallo-oro che sulle peliti lacustri rosso-ocracee, ed è talora ricoperto da colluvioni generate dal rimaneggiamento di originarie terre rosse. d ’ el i a et al. ( 1 9 8 7 ) segnalano nell’area di sanza un livello tufitico rimaneggiato e intercalato ad un paleosuolo in argille rosse residuali, attribuendone l’alterazione ad un regime climatico di tipo lateritico vigente nel pleistocene medio, più caldo e umido rispetto a quello attuale. un orizzonte di alterazione, che conferisce al deposito più superficiale una colorazione virata verso tonalità rosso mattone, si sviluppa per uno spessore di circa 3 metri dalla superficie topografica del fondovalle del bacino (alterite di s a n z a). a tetto dell’alterite si osserva localmente un suolo rel itto argi lloso-sabbioso di colore rosso-marrone spesso fino a 2 m. l’età relativa della successione fluvio-lacustre s . s . ospitata dalla depressione di sanza è stata ottenuta grazie alla correlazione geomorfologica e stratigrafica con i depositi lacustri del vallo di diano, di età nota. questi ultimi sono compresi, infatti, in un ampio intervallo temporale che va dal pleistocene inferiore e medio p.p. con le argille grigie del i ciclo lacustre, fino ad arrivare al pleistocene medio p.p. e olocene con i depositi fluvio-lacustri del ii ciclo (da santangelo, 1991). l’area di fondovalle del vallo di diano compresa tra buonabitacolo, montesano e bosco cerreta, è attualmente incisa e terrazzata per oltre 100 metri dall’alto corso del fiume tanagro e dai suoi affluenti. all’apice meridionale del bacino i depositi lacustri terrazzati della piana (i ciclo lacustre) passano in eteropia latero-verticale a conglomerati in facies di conoide alluvionale nella fascia pedemontana. un livello vulcanoclastico intercalato alle argille lacustri del i ciclo è stato campionato (campione cat 7) a circa 3 metri dalla sommità della superficie terrazzata (cfr. fig. 4) tra buonabitacolo e bosco cerreta. il tephra, spesso alcuni centimetri è formato da pomici poco alterate e abbondanti cristalli di k-feldspato (sanidino) ed è immerso in fig. 2 schema dei rapporti stratigrafici dei depositi continentali del bacino fluvio-lacustre di sanza. stratigraphic scheme of the fluvio-lacustrine deposits of the sanza basin. fig. 3 particolare del rapporto di eteropia latero-verticale tra i conglomerati sommitali e le argille siltose rosse del bacino con un orizzonte di alterazione a tetto, in contatto erosivo. geometric relationship between top-conglomerate and red silty clay of the fluvio-lacustrine succession. note also the erosional surface (white dashed line) separating the fluvio-lacustrine succession from the reddish weathered horizon. p. di leo et al. 193 una pasta di fondo rossastra.la corrispondenza planoaltimetrica tra i terrazzi deposizionali in conglomerati e quelli modellati nelle argille lacustri del i ciclo suggerisce, in accordo con santangelo (1991), che la sommità sub-pianeggiante di questi ultimi sia stata poco erosa prima dell’incisione verticale e corrisponda con buona approssimazione al top deposizionale del i ciclo di riempimento vallo di diano. le superfici terrazzate modellate nelle argille del i ciclo lacustre e distribuite nei pressi di bosco cerreta si raccordano, verso ovest, ai terrazzi erosionali di monticello m.te rotondo di sanza morfoscolpiti, a quote comprese tra circa 500 e 620 m s.l.m, in depositi silicoclastici pre-quaternari (t1 in fig. 5) e possono essere dunque associati allo stesso livello di base. questi ultimi rappresentano il relitto morfologico, inciso verticalmente dalla rete drenante, di un glaçis d’erosione e attualmente costituiscono parte della soglia morfologica tra la depressione di sanza e quella del vallo di diano (t1 in fig. 5). ad ovest della collina di sanza, a quote comprese all’incirca tra 550 e 430 m s.l.m., si rinvengono i terrazzi fluviali prodotti dall’incisione verticale del fiume bussento e dei suoi affluenti nel riempimento clastico del bacino (t2 in fig. 5). il rapporto di incastro morfologico tra i terrazzi dell’area di soglia (t1 in fig. 5) e quelli incisi dal fiume bussento (t2 in fig. 5) induce a ritenere i terrazzi fluviali dell’area di sanza più recenti. la sommità terrazzata dei depositi lacustri antichi del vallo (i ciclo di santangelo, fig. 5 profilo morfostratigrafico che indica i rapporti di incastro morfologico tra le superfici terrazzate del top deposizionale della successione fluvio-lacustre del bacino di sanza (t2) e quelle erosionali su substrato pre-quaternario del settore meridionale del vallo di diano (t1). morpho-stratigraphical relationship between the depositional top of the fluvio-lacustrine succession of the sanza basin (t2) and the quaternary terraced surface cutting the bedrock of the southern sector of the vallo di diano (t1). fig. 4 correlazioni tra i diversi log stratigrafici del bacino di sanza e del vallo di diano. stratigraphic correlations among different logs from sanza basin and vallo di diano. evoluzione morfotettonica quaternaria del bacino intermontano ... 194 1991) è dunque correlabile, in termini morfoe cronostratigrafici, alla superficie di erosione basale dei depositi fluvio-lacustri del bacino di sanza (fig. 4) e ne vincola l’età di inizio della sedimentazione al pleistocene inferiore-medio. sempre esternamente al bacino di sanza, nella porzione centrale del vallo di diano, a sud-est dell’abitato di sala consilina, al raccordo del fronte montuoso con l’area pedemontana, le operazioni di estrazione di inerti in una cava, nei pressi di grotta s. angelo, hanno messo in luce una successione clastica di oltre 30 metri di spessore, costituita da conglomerati prevalentemente carbonatici in facies di conoide alluvionale che poggiano in contatto erosivo basale su brecce di versante a clasti calcarei. la sommità del corpo deposizionale del conoide, di tipo erosivo e fortemente carsificata, è ammantata da un deposito argilloso-limoso rubefatto, fortemente alterato e pedogenizzato (alterite di s. a n g e l o). l’orizzonte di alterazione, che si sviluppa per circa 4 metri di spessore, è a sua volta ricoperto localmente da un suolo marrone-bruno che non raggiunge il metro di spessore (fig. 4). a poco meno di un metro di profondità, è stata campionata una lente vulcanoclastica (campione vd 22) formata da silt argilloso da marrone chiaro a giallo spessa poco più di 50 cm, intercalata nel deposito argilloso-limoso rossastro. il tephra risulta formato da pomici giallastre alterate e subarrotondate, mica scura, abbondanti cristalli di k-feldspato (sanidino) fresco e alterato, pirosseni e scorie. la posizione stratigrafica, gli aspetti litologici, il grado di alterazione del deposito e i caratteri morfoscopici della superficie di erosione carsificata hanno consentito di correlare con buona probabilità l’alterite di s. angelo a quella della successione fluvio-lacustre di sanza (alterite di sanza). poiché i depositi del ii ciclo lacustre del vallo di diano (sa n t a n g e l o, 1991) sono incastrati morfologicamente nei conglomerati del conoide di grotta s. angelo, sospesi e terrazzati rispetto al fondovalle attuale, è possibile attribuire questi ult imi genericamente al pleistocene medio. tale considerazione, unitamente alla presenza di una superficie erosiva che separa i conglomerati dall’alterite di s. angelo, permette di assegnare in via preliminare questa ultima al pleistocene superiore. in termini cronostratigrafici le due successioni continentali del vallo di diano sopra discusse e cioè le argille grigie infrapleistoceniche del i ciclo lacustre di buonabitacolo e le alteriti di grotta s. angelo del pleistocene superiore si collocano rispettivamente alla base e al tetto del riempimento fluvio-lacustre s . s. del bacino di sanza e consentono di datare quest’ultimo al pleistocene medio (fig. 4). 3.3. datazioni radiometriche informazioni geocronologiche sono state fornite dai due tephra campionati al top delle argille grigie del i ciclo lacustre (campione cat 7, cfr. fig. 4) e nell’alterite di grotta s. angelo (campione vd 22, cfr. fig. 4). le analisi sono state effettuate presso il laboratorio di geocronologia 4 0a r /3 9a r dell’istituto di geoscienze e georisorse del cnr di pisa (laurenzi, 2008, rapp. int.). per il calcolo del fattore di irraggiamento j è stato utilizzato come standard di flusso il sanidino fish canyon tuff, con un’età di 28.02 ma (re n n e et al., 1998), e a tale valore di età sono pertanto da riferire i dati cronologici ottenuti sui tephra campionati. il fattore j è stato calcolato dalla media delle due aliquote di standard dei campioni poiché non vi erano variazioni verticali apprezzabili di flusso neutronico in un caso (campione cat 7) e, mediante interpolazione esponenziale degli standard nell’altro (campione vd 22). le età sono state calcolate utilizzando le costanti di decadimento di st e i g e r & jäger (1977). nel campione cat 7 i cristalli sufficientemente grandi da permettere una misura su cristallo singolo sono solo tre, le altre misure sono effettuate su popolazioni di due (5 misure), tre (6 misure), e 4 cristalli (2 misure), per un totale di sedici analisi. non si osservano variazioni evidenti di età al variare del numero di cristalli utilizzati per le fusioni ed è possibile affermare che la popolazione è unica. l’età raccomandata per questo campione è l’età di isocrona: 706.3±8.1 ka (± 95 % conf.), 4 0 a r / 3 6 a r(iniz) =297.4±5.4, mswd=1.5, 16 punti analisi (tab. 1). nel campione vd 22 le dimensioni dei cristalli hanno permesso una sola misura su cristallo singolo, tutte le altre derivano dalla fusione di un numero variabile da 4 a 10 cristalli. l’età raccomandata per questo campione è l’età di isocrona: 106.7±1.6 ka (± 95 % conf.), 4 0a r /3 6a r(iniz) =298.4±6.3, mswd=1.03, 10 punti analisi (tab. 1). le datazioni radiometriche con il metodo 40ar/ 39 ar realizzate sui due livelli vulcanoclastici intercalati nella successione pleistocenica del vallo di diano (tab. 1), unitamente alle considerazioni di carattere litoe morfostratigrafico sui depositi fluvio-lacustri studiati e sui loro rapporti con quelli argilloso-siltosi del vallo di diano permettono di attribuire la successione fluvio-lacustre del bacino di sanza al pleistocene medio-superiore, e precisamente ad un intervallo cronologico compreso tra 706.3±8.1 ka e 106.7±1.6 ka (fig. 4). 4. mineralogia e geochimica dei depositi del bacino di sanza 4.1. metodi di indagine i campioni prelevati esclusivamente nella parte alta della successione pelitica del bacino di sanza e cioè nelle argille di sanza del pleistocene medio e nei depositi discordanti a tetto (silt e sabbie gialle, orizzonte vulcanoclastico e alterite di sanza) di età pleistocene superiore (fig. 2) ed analizzati nel presente lavoro sono costituiti da silt, silt sabbioso, e silt argilloso come suggerito dal diagramma di fo l k (1980) mostrato in tab. 1 – datazioni radiometriche di tefra intercalati nei depositi quaternari del vallo di diano. radiometric ages of the tephra sampled in the vallo di diano quaternary deposits. p. di leo et al. figura 6. l’analisi granulometrica è stata condotta con l’ausilio di un granulometro laser modello mastersizer e ver 1.2, della malvern instruments ltd., malvern, uk. l’individuazione delle fasi mineralogiche presenti nei 14 campioni selezionati è avvenuta mediante diffrattometria di raggi x. e’ stato utilizzato un diffrattometro per polveri della rigaku, modello miniflex, che utilizza una radiazione cukα, con fenditura variabile e s a m p l e s p i n n e r. il campione è stato polverizzato in mortaio di agata, quindi posto all’interno di un portacampione in modo da garantire un’orientazione casuale dei granuli. la distribuzione semi-quantitativa dei soli minerali argillosi è stata effettuata sulla frazione <2 µm, previa separazione mediante sedimentazione frazionata e trattamenti con glicol etilenico, riscaldanti e saturazione con mg. per l’individuazione della fasi mineralogiche è stato utilizzato il software macdiff 4.2, che utilizza un database mineralogico con schede indentificative dei minerali jcpds. le fasi mineralogiche sono costituite prevalentemente dai minerali argillosi, tra cui rientrano, in ordine di abbondanza, l’illite (ill), gli strati misti tipo illite/smentite (i/s) e tipo clorite/vermiculite (c/v), la caolinite (kaol) e l’halloysite (hall), e, in minor quantità, la clorite (chl) e la vermiculite (vm). nei campioni sono presenti anche quarzo (qtz) ed elevate percentuali (cfr. scheda-campione sn7) di feldspati (kfs). la presenza dell’halloysite è stata confermata anche dalla spettroscopia ad infrarosso (ftir) e dall’analisi termo-gravimetrica (tg-dta). gli spetti ftir ed le curve dta relativi alla frazione ultrafine (< 0,2 µm), in cui questa fase mineralogica è più abbondante, sono riportati nella figura 7. per queste indagini è stato utilizzato uno spettrofotometro ad infrarosso in trasformata di fourier (nicolet 5 pc) su pasticche di kbr, registrando lo spettro nel r a n g e di lunghezze d’onda di 4004000 cm1, ed un apparato termico simultaneo della seiko instrument inc. (uk), alle seguenti condizioni operative: peso del campione 20 mg, s t a n d a r d a l203, intervallo di temperatura 15-1050 °c, velocità di riscaldamento 20 °c/min, sensitività dta 105 µv, sensitività tg 10 7 µg, flusso di azoto. la micromorfologia dell’halloysite e la sua composizione chimica sono state indagate mediante microscopia elettronica a scansione con un microscopio elettronico modello fei-philips esem-feg quanta 200f, equipaggiato con una microsonda edax genesis 4000. le osservazioni sono state effettuare su campioni metallizzati sia con carbonio che con oro. la composizione chimica dei depositi pelitici del bacino di sanza è stata dedotta mediante l’uso congiunto della fluorescenza di raggi x (xrf, x r a y f l u o r e s c e n c e) per gli elementi maggiori e dell’icp-ms (inducticve coupled plasma mass spectroscopy) per gli elementi in traccia. i campioni sono stati omogeneizzati in mortaio di agata. un’aliquota è stata prelevata per le analisi in xrf (3 grammi) ed un’altra (5 grammi) è stata sottoposta a fusione con litio metaborato/tetraborato per le analisi icp-ms. la loi è stata determinata gravimetricamente previo riscaldamento a 950 °c per l’intera notte. le analisi chimiche sono state condotte presso i laboratori dell’actlabs, ontario, canada. i risultati dell’analisi chimica sono riportati in tab.2. 4.2. weathering e implicazioni paleoclimatiche nei sedimenti del bacino di sanza è stata riconosciuta un’associazione mineralogica costituita prevalen195 fig. 6 classificazione granulometrica (folk, 1980, modif.) delle peliti campionate nel bacino di sanza. folk’s ternary textural diagram of the pelitic sediments from the sanza basin. fig. 7 1) curva dta della frazione < 0.2 µm del campione sn4 (a) e dello standard di caolinite ben cristallizzata (b); 2) spettro ftir della frazione < 0.2 µm del campione sn4 (a) e dello standard di caolinite ben cristallizzata (b). 1) dta curve of the < 0.2 µm fraction of the sn4 sample (a) and the standard of the well-crystallized kaolinite (b); 2) ftir spectrum of the < 0.2 µm fraction of the sn4 sample (a) and the standard of the well-crystallized kaolinite (b). temente da strati misti tipo i/s e c/v, illite, vermiculite+clorite, caolinite+halloysite, feldspati ed ematite+ goethite. questa associazione è compatibile con un elevato grado di alterazione delle peliti, come dimostraevoluzione morfotettonica quaternaria del bacino intermontano ... to anche dall’analisi del chemical index of alteration (cia, nesbit & young, 1982), espresso come: cia = [al2o3/(al2o3 + cao* + na2o + k2o)] dove cao* rappresenta il cao associato con la sola frazione silicatica del campione, e dal diagramma ternario a-cn-k (fig. 8; nesbit & young, 1989). la diminuzione, in termini di abbondanza, degli strati misti di tipo i/s e c/v e della vermiculite, associata ad un aumento della caolinite registrata a partire dai sedimenti più antichi (argille di sanza del pleistocene medio) a quel li più recenti (alterite di sanza del pleistocene superiore) è compatibile con uno scenario paleoclimatico che da un clima temperato freddo, con alternanza di periodi secchi e piovosi (presenza di vermiculite e strati misti i/s e c/v), evolve verso un clima caldo-umido (abbondanza di caolinite). la presenza di una fase disidratata di halloysite (7 å) con h a b i t u s prevalentemente sferoidale, come indicato dall’analisi micromorfologica condotta al microscopio elettronico a scansione (fig. 9) è fortemente indicativa di una componente vulcanoclastica diversamente dispersa, in termini di abbondanza, nei sedimenti analizzati. è ben noto, infatti, che tale fase mineralogica si origina oltre che dall’alterazione di feldspati e biotite anche dal w e a t h e r i n g di vetro vulcanico (di x o n, 1989; singh & gilkes, 1992). quest’ultima tipologia di halloysite mostra, nella maggior parte dei casi, una tipica morfologia sferoidale, a differenza di quella originatasi per alterazione di minerali cristallini (feldspati e miche), che invece presenta prevalentemente h a b i t u s t u b o l a r e (tazaki, 1978). grosse quantità di halloysite con habitus prevalentemente sferoidale sono state rinvenute nei depositi piroclastici alterati di ailano (complesso vulcanico del roccamonfina), e la formazione di questa fase mineralogica è stata attribuita ad un meccanismo di dissoluzione/precipitazione a seguito di alterazione in condizioni di elevata idratazione in ambiente molto ristretto e ben confinato (scala dei micropori; adamo et al., 2001). l’esistenza nei sedimenti lacustri del bacino di sanza di prevalente halloysite 7 å suggerisce l’alternanza di cicli climatici umidi e secchi, con una stagione secca piuttosto prolungata tale da favorire la rapida formazione, e preservazione, di questa fase (ziegler et al., 2003). la presenza di una componente vulcanoclastica è anche supportata dall’analisi delle distribuzioni dell’allu196 tab. 2 concentrazione degli elementi maggiori (espressi in percentuale in peso) e degli elementi in traccia (espressi in ppm) dei depositi del bacino di sanza. major and trace elements in the sediments of the sanza basin. fig. 8 chemical index of alteration (cia, nesbitt & young, 1982) e diagramma ternario a-cn-k (nesbitt & young, 1989), dove il vertice a è rappresentato dalla concentrazione (espressa in percentuale in peso) di al2o3, quello cn da (cao*+na2o), ed il vertice k dalla concentrazione di k2o. chemical index of alteration (cia, nesbitt & young, 1982) and ternary diagram a-cn-k (nesbitt & young, 1989), where a is the al2o3 concentration (weight percentage), cn is the (cao*+na2o) concentration and k is the k2o concentration. p. di leo et al. minio (al2o3), degli elementi di transizione definiti geochimicamente “mobili” (v, ni, cr), e di quelli “immobili” (zr e ti, espresso come tio2). nel diagramma di discriminazione tra sedimenti vulcanoclastici alterati e sedimenti clastici (andreozzi et al., 1996) è evidente come in tutti i 14 campioni analizzati sia presente una componente vulcanoclastica (fig. 10a). la discriminazione tra sedimenti clastici e vulcanoclastici è, infatti, particolarmente efficace se si contrappongono gli elementi di transizione quali v, fe, ni, zn e cr estremamente mobili durante le trasformazioni diagenetiche poichè particolarmente sensibili alle variazioni delle condizioni redox, con una particolare affinità per la sostanza organica, e facilmente adsorbiti sui minerali argillosi (pearce & jarvis, 1995; hower et al., 1976) a quegli elementi definiti “immobili” come il ti e lo zr. il confronto geochimico mediante analisi statistica multivariata condotto con il metodo della pca (principal component analisys, fig. 10b) tra i sedimenti analizzati e i depositi piroclastici del complesso vulcanico del roccamonfina (pa o n e, 2004; ad a m o et al., 2001) e del monte vulture (sc h i a t t a r e l l a et al., 2005) ha inoltre suggerito, per la componente vulcanoclastica, un’analogia con i prodotti alterati del pleistocene medio (adamo et al., 2001; de gennaro et al., 1973) appartenenti al primo ciclo eruttivo (630-385 ka, supersintema di roccamonfina; de ri t a et al., 1998) del complesso vulcanico del roccamonfina. tale peculiarità, seppure indirettamente, fornisce un ulteriore dato circa l’età mediopleistocenica dei sedimenti fluvio-lacustri del bacino di sanza. 5. caratteri morfostrutturali ed evoluzione morfotettonica la conca intermontana che ospita il bacino di sanza si dipana in direzione trasversale rispetto all’andamento dell’asse della catena e di molti bacini quaternari, allungandosi in direzione e-o, con sviluppo rettilineo per circa 10 km (fig. 11). la planimetria della valle è in realtà più complessa, sia per la presenza di numerosi elementi tettonici che interessano il tratto rettilineo, sia perché alle terminazioni di questo si saldano due flessi orientati in direzione ne-so, corrispondenti ai segmenti vallivi che, tramite deboli soglie morfologiche, 197 fig. 9 esempio di spettro edxra dell’halloysite sferoidale. il rapporto molare sio2/ a l2o3 medio di 2,35 è stato ricavato sulla base di 23 analisi puntuali. edxra spectral example of the spheroidal halloysite. the mean molar ratio (2,35) of sio2/al2o3 has been obtained by 23 analyses. fig. 10 a) diagramma di discriminazione tra sedimenti vulcanoclastici alterati e sedimenti clastici (andreozzi et al., 1996); b) pca condotta sui campioni del bacino di sanza (questo lavoro), sulle tefriti (paone, 2004) e sui depositi piroclastici alterati (ad a m o et al., 2001) del complesso vulcanico del roccamonfina, sulle ignimbriti di ventotene (pa o n e, 2004) e sulle vulcaniti del monte vulture (sc h i a t t a r e l l a et al., 2005) utilizzando una matrice di input composta dalle variabili chimiche rappresentate dalle concentrazioni, espresse in percentuali in peso, degli ossidi degli elementi maggiori. a) discrimination diagram of weathered volcanoclastic deposits and clastic sediments (an d r e o z z i et al., 1996); b) pca relative to major elements in the pelitic deposits sampled in the sanza basin, in the tephrites (pa o n e, 2004) and in the weathered pyroclastic deposits of the roccamonfina volcano (ad a m o et al., 2001), in the ignimbrite of ventotene island (pa o n e, 2004), and in the volcanics of monte vulture (sc h i a t t a r e l l a et al., 2005). evoluzione morfotettonica quaternaria del bacino intermontano ... raccordano la depressione al vallo di diano, verso est, e all ’a lto corso del fiume mingardo, verso ovest. va infine rilevato che il bacino, nella parte centrale del corridoio morfologico, si dirama verso sud-est, a lambire il versante occidentale di monte l’alta (dorsale del monte forcella), fino a chiudersi al vertice meridionale di una depressione triangolare, dove peraltro il fiume bussento devia bruscamente verso sud-ovest con un angolo di circa 90°. questa porzione del bacino è pertanto parallela al vallo di diano, rispetto al quale la stretta di sanza nel suo complesso forma invece un angolo di circa 70° (fig. 11 e 12). il relitto morfologico del versante di linea di faglia che forma il bordo settentrionale del bacino presenta un rigetto topografico di oltre 800 metri, separa il fondovalle sub-pianeggiante dai rilievi carbonatici del gruppo montuoso del monte cervati, ed è inciso trasversalmente da corsi d’acqua, il cui approfondimento verticale ha prodotto facce trapezoidali più o meno conservate (fig. 12). il tracciato del fiume bussento è in evidente discordanza oro-idrografica (più a sud peraltro si inforra nei calcari di serra piana, in prossimità dell’abitato di caselle in pittari) ed è controllato da strutture tettoniche con andamento e-o ed appenninico nel primo tratto e nne-sso in quello successivo, oltre il gomito fluviale. anche la rete idrografica di basso rango gerarchico è condizionata da famiglie di faglie e fratture, come messo in luce da tratti rettilinei in valli a v o inforrati, 198 fig. 11 morfostrutture positive e negative, e principali linee tettoniche dell’area di studio. positive and negative morpho-structures, and main tectonic features of the study area. fig. 12 schema geomorfologico dell’area di studio. geomorphological sketch map of the study area. p. di leo et al. deviazioni fluviali ad angolo retto, confluenze anomale con angolo uguale o maggiore di 90° (fig. 12). nella parte centrale del bacino si erge dal fondovalle per oltre un centinaio di metri il rilievo collinare su cui sorge il centro abitato di sanza, formato da calcari cretacici dell’unità alburno-cervati-pollino. questi divide il fondovalle in un settore occidentale, a pianta triangolare, e uno orientale, allungato in direzione est-ovest, in comunicazione tra loro attraverso due stretti passaggi vallivi. ad est, l’area del rilievo del monticello costituisce l’attuale soglia morfologica del bacino rispetto alla più ampia depressione morfostrutturale del vallo di diano. il basso morfostrutturale che ospita la successione clastica quaternaria del bacino è impostato lungo la linea di sanza (fig. 11), espressa da una serie di strutture tra le quali predomina la faglia in direzione e-o del bordo meridionale del massiccio del cervati, caratterizzata da cinematica polifasica. la prosecuzione della linea di sanza è ben evidente verso ovest, nell’area silentina, dove disloca con senso di tagl io sinistro la struttura del monte centaurino rispetto a quella di monte sacro. verso est, la linea attraversa il vallo di diano con le faglie che hanno dislocato i depositi del i ciclo lacustre, per proseguire nei monti della maddalena, ribassando l’area delle conche tettono-carsiche di magorno, spigno, piani perillo. ancora più ad oriente, il lineamento tettonico confina a sud il bacino dell’alta val d’agri e ne controlla la media valle fin oltre la stretta di pietra del pertusillo. l’o f f s e t sinistro tra la valle del torrente armento in sinistra orografica del fiume agri e quella del torrente racanello in destra rappresenta qui l’espressione morfologica dell’attività tettonica recente della linea. in quest’area è notevole il rilascio di energia sismica lungo una struttura profonda che interrompe la continuità di quelle appenniniche (burrato & valensise, 2008). pertanto, la linea di sanza è parte di un più ampio lineamento di importanza regionale, che viene qui denominato linea alto bussento – pietra del pertusillo, che attraversa l’appennino campano-lucano per oltre 70 km con chiara espressione morfostrutturale, controllando ad ovest il bacino di sanza, determinando nella sua porzione centrale il rigetto morfologico della dorsale dei monti della maddalena, e condizionando ad est l’andamento della media valle del fiume agri (fig. 13). la linea di sanza pone a contatto l’imponente morfostruttura carbonatica del monte cervati a nord con quella calcarea del monte forcella e quella terrigena del monte centaurino a sud. le successioni rocciose di questi rilievi sono accostate tettonicamente lungo la linea del bussento (fig. 11), mentre le due morfostrutture positive sono separate fisiograficamente dalla parte meridionale del bacino di sanza. similmente, la morfostruttura del monte cervati è divisa in due blocchi minori il blocco della raja del pedale monte cervati e il blocco del monte cariusi serra del corneto – separati dalla linea di piaggine, una faglia transpressiva che si interrompe contro la linea di sanza (fig. 11). il blocco di raja del pedale monte cervati è separato dalla sinclinale di monte sacro dalla linea di monte caravello, una faglia ad alto angolo orientata ono-ese, e dalla linea di rofrano, un sovrascorrimento orientato all’incirca nno-sse responsabile della sovrapposizione delle unità tettoniche di origine interna su quelle mioceniche dell’unità alburno-cervati-pollino. a nord, la linea di t.pa rotonda, costituita da segmenti con età e cinematiche diverse, orla la morfostruttura del monte cervati, separandola dalla depressione di villa littorio monte s. giacomo, un basso morfostrutturale con orientazione ono-ese, impostato nelle unità interne, che confluisce nel vallo di diano. ancora più a settentrione, i carbonati dell’unità alburno-cervati-pollino riemergono nella complessa morfostruttura del monte motola. l’attività tettonica plio-quaternaria e le tappe del processo di esumazione ed evoluzione morfologica della struttura sono state recentemente illustrate da pu t i g n a n o & schiattarella (2008), che considerano l’area una zona di concentrazione della deformazione tardopliocenica-quaternaria. gli autori riconoscono, inoltre, che il sollevamento tettonico dell’area non è stato costante, come testimoniato dall’interruzione dell’attività tettonica lungo le superfici di faglia nella parte alta del santerniano compensata in termini di crescita del rilievo da un upl ift regionale che determina il modellamento di superf ici d i spianamento di diverso ordine. la linea del vallo di diano è rappresentata da un fascio di faglie con cinematica diretta, or ientato in senso appenninico, che ribassa a gradinata la struttura dei monti della maddalena al di 199 fig. 13 schema tettonico dell’appennino meridionale. la linea a tratti indica la zona di trasferimento denominata “linea del bussento – pietra del pertusillo”. tectonic scheme of the southern apennines. the dark dashed line indicates the transfer zone here named “bussento river – pietra del pertusillo line”. evoluzione morfotettonica quaternaria del bacino intermontano ... sotto del riempimento quaternario del bacino omonimo (fig. 11). l’analisi morfologica ha messo in luce anche la presenza di varie generazioni di superfici di spianamento relitte, a carattere poligenico, modellate nel corso del plio-quaternario in un contesto di morfogenesi carsica più o meno evoluta, o in ambiente periglaciale e fluviale, come testimoniato dai depositi detritici antichi e da linee di impluvio fossili. sulla sommità del massiccio del cervati si osservano, ad esempio, sia la conca endoreica dei monti di vallivona (fig. 12) che reticoli fluviali sospesi. forme analoghe sono morfoscolpite anche nella parte meridionale del bacino, nella morfostruttura calcarea del monte forcella e, almeno per quanto attiene ai reticoli fossili, nelle unità terrigene del monte centaurino. il modellamento delle paleosuperfici del monte cervati (ascione & cinque, 1995) viene attribuito ad almeno due episodi erosionali pre-lacustri, separati da un evento tettonico collocato tra la fine del pliocene superiore e l’ inizio del pleistocene inferiore (santangelo, 1991). le superfici di erosione modellate sui rilievi che circondano il bacino di sanza sono distribuite in lembi relitti posti ad altezze comprese tra 1900 e 700 m s.l.m. questi sono stati raggruppati in classi altimetriche omogenee per ogni singola morfostruttura, come proposto da basili et al. (1999). la loro distribuzione è stata riportata lungo un transetto n-s, ortogonale alla direzione di allungamento del bacino e alla linea di sanza (fig. 14). la morfostruttura del monte cervati (a nel diagramma di fig. 14) presenta almeno sei classi altimetriche di superfici che digradano in parte anche verso e fino al bordo occidentale del vallo di diano. la morfostruttura del monte forcella (c nel diagramma di fig. 14) presenta quattro classi altimetriche, mentre quella del monte centaurino (b nel diagramma di fig. 14) soltanto due. la bassa frequenza delle superfici di spianamento relitte nell’ultima morfostruttura è dovuta alla maggiore erodibilità dei terreni che la costituiscono rispetto a quelle carbonatiche. la superficie terrazzata del fondovalle del bacino di sanza, compresa nell’intervallo di quota 550430 m, è stata inserita nel diagramma di figura 14 come superficie di riferimento comune ai tre transetti. la distribuzione asimmetrica delle classi di superfici sui due bordi opposti del bacino e la mancata corrispondenza altimetrica tra le sequenze di superfici spianate (fig. 14) indicano che l’evoluzione del paesaggio nelle singole morfostrutture è stata fortemente condizionata dall’attività tettonica delle faglie associate alla linea di sanza. le quattro classi di superfici poste a quote più elevate (a in fig. 14) suggeriscono che l’esumazione della morfostruttura del monte cervati è avvenuta con un ritmo di sollevamento costante che ha permesso l’asportazione delle coltri terrigene di provenienza interna come già riconosciuto da as c i o n e & ci n q u e (1999) nell’area tirrenica e da putignano & schiattarella (2008) nella dorsale del monte motola. i versanti che delimitano verso valle le superfici spianate comprese nella classe altimetrica di 1000-1300 m attribuite a un generico pliocene superiore da ascione & cinque (1999) e all’intervallo pliocene superiore pleistocene inferiore da pu t i g n a n o & sc h i a t t a r e l l a (2008), relativamente all’area del monte motola – presentano un rigetto morfologico di circa 500 m rispetto al fondovalle terrazzato, di gran lunga superiore a quello dei versanti che bordano le altre classi di superfici (fig. 14). tale differenza può essere giustificata solo accoppiando al processo di esumazione, indotto dal sollevamento regionale, l’attività tettonica della linea di sanza nel corso del pleistocene inferiore. la mancanza di simili rigetti morfologici tra classi di superfici contigue nella morfostruttura del monte forcella può essere legata alla scomposizione tettonica delle stesse paleosuperfici, in modo da simulare l’effetto di una sequenza continua. 6. analisi mesostrutturale e paleomagnetismo l’analisi della deformazione fragile alla mesoscala ha permesso di riconoscere le principali famiglie di faglie e fratture nei carbonati mesozoici dei rilievi del monte cervati e del monte forcella, rispettivamente a nord e a sud della depressione tettonica di sanza, e nei depositi continentali quaternari del bacino. il diagramma azimutale dei sistemi di frattura misurati nei carbonati del bordo settentrionale del bacino (fig. 15a) mostra un t r e n d appenninico dominante (n150°-160°) e due addensamenti significativi in corrispondenza delle classi n90°-100° e n120°-130°, oltre ad un andamento antiappenninico (n50°-60°) meno rappresentato. i dati della fratturazione del settore meridionale (fig. 15b) evidenziano un massimo di frequenza espresso dalla classe percentuale n110°-120° e andamenti secondari in coincidenza delle classi orientate n30°-40° e n160°170°. il diagramma relativo al sistema di frattura rilevato nelle peliti rosse e nel silt sabbioso giallo di sanza (fig. 15c) mostra un t r e n d d o m i n a n t e antiappenninico (n60°-70°) e andamenti di minor peso statistico e di pari rango percentuale relativi alle classi n0°-10°, n110°-140° e n160°-170°. i dati giaciturali e cinematici relativi alle faglie rilevate lungo i bordi del bacino sono riportate nel diagramma di densità di fig. 16, che mostra la presenza di due s e t di faglie sub-verticali con direzione n115° e circa n-s. un piano di faglia con giacitura 165°/60°, 200 fig. 14 distribuzione in classi altimetriche delle superfici di spianamento reli tte del monte cervati (a), del monte centaurino (b) e del monte forcella (c), lungo un transetto meridiano. altitudinal arrangement of the relict erosional surfaces along a ns oriented transect, recognized in the monte cervati (a), monte centaurino (b), and monte forcella (c) morpho-structures. p. di leo et al. rilevato poco a est di sanza, disloca i depositi fluviolacustri e mette a contatto i conglomerati basali del letto della faglia con la successione conglomeraticoargillosa più recente del tetto. in località verivertola il substrato calcareo e le peliti mediopleistoceniche sono dislocati da un piano di faglia con giacitura 160°/70°, che rappresenta la prosecuzione della struttura sopra descritta. la geometria complessiva della faglia suggerisce un movimento obliquo legato a cinematica trastensiva destra, compatibile con la direzione di estensione in direzione ne-so dedotta dallo stereogramma relativo all’analisi dell’intera popolazione di faglie (fig. 17). poiché le faglie che dislocano la successione fluvio-lacustre quaternaria sono da considerarsi le più giovani dell’area di studio, ne consegue che il regime tettonico estensionale ad asse antiappenninico è stato certamente attivo durante la storia deformativa più recente del bacino. tale attività è stata però preceduta da un diverso regime tettonico, come evidenziato dalla geometria della linea di sanza, lungo la quale si registra una rilevante dislocazione orizzontale, stimabile sulla base dei punti di cut-off identificati nella proiezione della terminazione occidentale della struttura monoclinale del monte forcel la sulla l inea (val lone dell’inferno) e nel vertice sud-occidentale del rilievo di raia del pedale. in ogni caso, una parte significativa del rigetto è stata guadagnata in tempi infrapleistocenici (entità dell’o f f s e t orizzontale dei depositi clastici del bacino di sant’arcangelo affioranti lungo la valle dell’agri). sotto tali condizioni cinematiche, lungo i flessi della linea di sanza si realizzano locali ma vistosi fenomeni di traspressione, come l’espulsione delle dolomie triassiche dell’unità alburno-cervati-pollino (che non affiorano in un’area di oltre 1200 km2), in coincidenza del flesso orientale della linea, a ridosso del vallo di diano. le informazioni cinematiche dedotte dai dati mesoe morfostrutturali sono state corroborate dalle analisi dell’anisotropia della suscettività magnetica (ams) condotte sui depositi quaternari del bacino e segnatamente su campioni di brecce di versante antiche (vd01 in fig. 18) e silt argillosi rossi (vd03 in fig. 18). l’orientazione spaziale degli assi della suscettività magnetica kmax, kint e kmin rappresentata in proiezione equiareale (fig. 18) evidenzia per entrambi i campioni un ellissoide oblato che indica un fabric di tipo misto, sedimentario e tettonico. nel campione vd01 (brecce antiche) la direzione degli assi di suscettività consente di ricavare una lineazione magnetica compatibile con una direzione di massima compressione orientata ne-so. le brecce di versante appaiono quindi deformate da un evento tettonico di tipo compressivo, in accordo con il trasporto tettonico regionale delle unità del substrato e dei bacini-satellite mio-pliocenici, a sua volta compatibile con la direzione di massimo raccorciamento calcolata per il campo deformativo prodotto dal fagliamento trascorrente plio-pleistocenico lungo le direttrici n120° diffuse alla scala della catena (schiattarella, 1998). il campione vd03 (peliti rosse) mostra una direzione di lineazione magnetica che indica una direzione di massima estensione in senso antiappenninico. nell’intervallo cronologico relativo ai due campioni si assiste pertanto ad una inversione degli assi del campo deformativo. durante la fase estensionale, evidentemente di età mediopleistocenica, la zona di taglio trascorrente e-o – 201 fig. 15 diagrammi di frequenza azimutali delle famiglie di frattura ricavati nell’area di studio. in (a) e (b) i dati sono riferiti, rispettivamente, ai carbonati del massiccio del monte cervati e del monte forcella, che delimitano rispettivamente a nord e a sud il bacino di sanza; in (c) i dati sono relativi ai depositi fluvio-lacustri del bacino. rose diagrams of the fracture systems of the study area, related to the monte cervati (a) and monte forcella (b) carbonates (i.e. northern and southern sides of the sanza basin, respectively), and to the sanza fluvio-lacustrine deposits (c). fig. 16 diagramma di densità dei poli delle faglie misurate nei calcari del monte cervati e del monte forcella (reticolo di schmidt, emisfero inferiore, n = 41). stereoplot of the faults collected in the monte cervati and monte forcella carbonates (schmidt net, lower emisphere, n = 41). evoluzione morfotettonica quaternaria del bacino intermontano ... che per i suoi caratteri geometrici e la sua orientazione rispetto alle direttrici tettoniche regionali può essere interpretata come una transfer zone – viene riattivata in trastensione destra: ciò permette la creazione dell’a ccomodation space per i sedimenti fluvio-lacustri e determina le condizioni di endoreicità del bacino. il campo di stress responsabile di tali eventi è in accordo con la deformazione dei sedimenti del i ciclo lacustre del vallo di diano (fig. 19). la forma triangolare in planimetria della porzione meridionale del bacino di sanza suggerisce che la genesi di una preesistente paleo-depressione nell’area dell’alto bussento, in cui sedimentavano i depositi cla202 fig. 17 stereogramma delle faglie con indicatori cinematici rilevate nei calcari mesozoici affioranti ai bordi del bacino e nei depositi quaternari del riempimento fluvio-lacustre (a) e relativo campo tensoriale (b). stereonet of the faults collected both in the mesozoic carbonates (a) and in the pleistocene fluvio-lacustrine deposits of the study area, and relative stress field (b). fig. 18 ellissoide di distribuzione in proiezione equiareale degli assi di suscettività magnetica km a x, ki n t e km i n m i s u r a t i nei campioni provenienti dalle brecce antiche (vd01) e dal silt argilloso rosso (vd03). km a x, ki n t e km i n magnetic susceptibility axes (schimdt net, lower emisphere) measured in the ancient breccia (vd01) and in the red silty clay (vd02) sampled in the study area. p. di leo et al. stici pre-lacustri (formazione di centola, o suoi elementi rimaneggiati), sia stata prodotta da una rotazione antioraria del blocco cinematico del monte forcella in seno alla trascorrenza sinistra suprapliocenica – infrapleistocenica (fig. 19). 7. discussione dei dati e conclusioni l’approccio multidisciplinare nello studio dell’area della stretta di sanza, attualmente occupata dai sedimenti pleistocenici dell’omonimo bacino fluvio-lacustre, ha permesso di ricostruire la loro successione stratigrafica, la scansione temporale dei processi deformativi responsabili della cinematica di apertura del bacino e dell’evoluzione morfotettonica della depressione, nonché di delineare il contesto paleoclimatico nel quale tali accadimenti hanno avuto luogo. la datazione radiometrica con il metodo 40ar/39ar realizzata su cristalli di sanidino presenti in due tephra intercalati nei depositi continentali del vallo di diano e l’analisi chimico-mineralogica degli elementi vulcanoclastici presenti nelle argille rosse di sanza hanno tra l’altro consentito di vincolare cronologicamente la base e il tetto della successione fluvio-lacustre. il bacino di sanza è collocato all’interno di una fascia di deformazione ampia da 1 a 2 km, per una lunghezza di oltre 10 km (fig. 11). i suoi sedimenti sono solo in piccola parte insediati nella stretta morfologica, mentre si espandono verso sud nella parte centrale della depressione. la fascia e-o rappresenta una porzione di una linea di trasferimento di importanza regionale (linea alto bussento – pietra del pertusillo), di cui la linea di sanza rappresenta solo il tratto dell’estremità occidentale (fig. 13). questa struttura ha dislocato le unità strutturali della catena durante il neogene, ponendo a contatto lungo piani ad alto angolo le successioni mesozoiche di mare basso con i terreni pelagici delle unità interne, ed ha continuato a funzionare in tempi quaternari, quando peraltro diventa sede di drenaggio del deflusso idrico superficiale. due stadi di deformazione fragile sono responsabili della genesi e dell’evoluzione del bacino: il primo, che determina la creazione dello spazio sedimentario in una paleo-depressione di forma triangolare, è caratterizzato da movimenti orizzontali con senso di taglio sinistro lungo la linea di sanza e rotazione antioraria del blocco del monte forcella; il successivo, legato alla distensione regionale ad asse ne-so, produce le condizioni di endoreicità che determinano l’accumulo della successione fluvio-lacustre del bacino di sanza s . s., sotto condizioni di estensione obliqua (fig. 19). i tratti vallivi ad est e ovest del bacino sedimentario intramontano rappresentano in entrambe le fasi zone di bypass di sedimenti fluviali. l’attività trascorrente sinistra della linea di sanza durante la fase di strutturazione precoce del bacino produce piccoli bassi morfostrutturali di tipo sag pond (keller & pinter, 1996) che ospitano la sedimentazione sintettonica delle brecce di versante antiche. gli eventi tettonici responsabili dello smembramento delle superfici spianate relitte dell’area di studio, modellate sui carbonati mesozoici e sui depositi terrigeni delle unità interne a partire dal miocene superiore e fino al pleistocene inferiore (am a t o & ci n q u e, 1999; putignano & schiattarella, 2008), costituiscono il limite cronologico ante quem da tenere in considerazione ai fini della collocazione temporale della genesi del basso morfostrutturale. la tettonica trascorrente del pliocene superiore – pleistocene inferiore, ampiamente documentata in appennino meridionale (turco et al., 1990; ci n q u e et al., 1993; sc h i a t t a r e l l a, 1996, 1998, tra gli altri) e nella vicina dorsale carbonatica del m.te motola (pu t i g n a n o & sc h i a t t a r e l l a, 2008), rappresenta infatti l’evento deformativo responsabile della primitiva disarticolazione delle superfici di spianamento nell’area di studio. un campo deformativo con direzione di massimo raccorciamento ne-so è registrato anche dalla disposizione dell’asse di allungamento dei minerali ferromagnetici presenti nella matrice nelle brecce di versante antiche attribuite al pleistocene inferiore. le misure dell’anisotropia della suscettività magnetica (ams) effettuate per campioni provenienti dalle peliti rosse mediopleistoceniche (comprese in un range cronologico di 706.3±8.1 ka e 106.7±1.6 ka) indicano invece una direzione di estensione ne-so (fig. 18). la tettonica distensiva del pleistocene medio è responsabile della produzione del fascio di faglie della linea del vallo 203 fig. 19 schema dell’evoluzione cinematica dell’area del bacino di sanza (per spiegazioni vedi testo). kinematic evolution of the area including the sanza basin (see text for details). evoluzione morfotettonica quaternaria del bacino intermontano ... di diano e della riattivazione della linea di sanza come faglia trastensiva destra. vengono così tettonicamente dislocate e reincise ad opera della rete drenante le argille lacustri del i ciclo deposizionale del vallo, la cui porzione superiore già assegnata ad un’età compresa tra circa 0.6±0.2 e 0.7±0.2 ma da santangelo (1991) in affioramento e a 0.596±0.006 ma in sondaggio da karner et al. (1999) – è stata qui datata con il metodo 4 0a r /3 9ar a 706.3±8.1 ka. al contempo, viene creato lo spazio fisico che inizia ad ospitare la sedimentazione fluvio-lacustre di sanza. l’analisi cinematica della popolazione di mesofaglie rilevate lungo i bordi del bacino mostra un asse tensile in accordo con un simile quadro e con i dati di ams. l’estensione in direzione ne-so ed il sollevamento che ne consegue hanno controllato anche l’evoluzione e la successiva estinzione del bacino. la sequenza verticale del riempimento clastico della depressione tettonica di sanza è di tipo log-normale (fu), come testimoniato dai conglomerati basali che evolvono verso l’alto a facies più francamente fluvio-lacustri con depositi siltoso-argillosi nelle aree distali e conglomerati in quelle prossimali, troncate a tetto da sedimenti sottili (silt e sabbie gialle in fig. 2) che presentano gli stessi caratteri microscopici di quelli descritti da lippmann-provansal (1987) lungo il litorale del cilento, legati sia a flussi idrici incanalati che a trasporto eolico e alteriti che indicano una cessazione delle sedimentazione avvenuta nel pleistocene superiore (intorno a 106.7±1.6 ka) a causa dello svuotamento del bacino per erosione della soglia nel settore meridionale. il riconoscimento nei sedimenti lacustri siltosoargillosi del bacino di un’associazione mineralogica costituita prevalentemente da strati misti tipo i/s e c/v, illite, vermiculite+clorite, caolinite+halloysite, feldspati ed ematite+goethite unita ad alti valori del cia (80-90) suggerisce che tali depositi abbiano raggiunto un grado di alterazione elevato. la diminuzione, in termini di abbondanza, degli strati misti di tipo i/s e c/v e della vermiculite, associata ad un aumento della caolinite registrata a parti re dai sedimenti più antichi (pleistocene medio) a quelli più recenti (pleistocene superiore) è compatibile con uno scenario paleoclimatico che da un clima temperato freddo, con alternanza di periodi secchi e piovosi (presenza di vermiculite e strati misti i/s e c/v), evolve verso un clima caldo-umido (abbondanza di caolinite). nei sedimenti del bacino di sanza è presente una componente vulcanoclastica, i cui caratteri mineralogici (presenza di halloysite 7å prevalentemente sferoidale) e chimici evidenziano una forte analogia con i depositi vulcanoclastici alterati di età mediopleistocenica (de gennaro et al, 1973; adamo et al., 2001) appartenenti al primo ciclo eruttivo (630-385 ka, supersintema di roccamonfina, de rita et al., 1998) del complesso vulcanico del roccamonfina. il tipo di halloysite rinvenuta è strettamente connesso all’alternanza di cicli climatici umidi e secchi, con una stagione secca piuttosto prolungata tale da favorire la rapida formazione, e preservazione, di questa fase. il bacino di sanza si configura come una depressione tettonica complessa che si è formata, a differenza dei più estesi bacini intermontani del vallo di diano e dell’alta val d’agri, lungo una importante zona di trasferimento della deformazione orientata in senso e-o ed attiva anche prima della sua nascita, qui denominata linea alto bussento – pietra del pertusillo, e di cui la linea di sanza rappresenta l’espressione morfostrutturale occidentale. i caratteri esclusivi di un simile bacino non sono ascrivibili a tipologie contemplate nelle varie classificazioni note in letteratura, e permettono di codificare per la prima volta questo tipo di bacini come “di zona di trasferimento”. ringraziamenti gli autori desiderano ringraziare il prof. n. ciaranfi e un anonimo r e f e r e e per la accurata revisione del manoscritto. lavoro pubblicato con fondi di ateneo 2007 (resp. s.i. giano, m. schiattarella). bibliografia a a . v v . (2008) carta geologica regionale 1:25.000 sanza 504 se. systemcart, roma. ad a m o p., vi o l a n t e p. & wi l s o n m . j . (2001) t u b u l a r and spheroidal halloysite in pyroclastic deposits in the area of the roccamonfina volcano (southern italy). geoderma, 99, 295-316. an d r e o z z i m., di n e l l i e. & ta t e o f . (1996) geochemical and mineralogical criteria for identification of ash layers in the stratigraphic framework of a foredeep; the early miocene mt. cervarola sandstone, northern italy. chem. geol., 117, 2-17. amato a. & cinque a. (1999) erosional landsurfaces of the campanolucano apennines (s. italy): genesis, evolution, and tectonic implication . tectonophysics, 315, 251-267. am o r e f.o., bo n a r d i g., ci a m p o g., de ca p o a p . , pe r r o n e v. & sg r o s s o i . (1988) relazioni tra i “flysch interni” e domini appenninici: reinterpretazione delle formazioni di pollica, san mauro ed albidona e il problema dell’evoluzione inframiocenica delle zone esterne appenniniche. mem. soc. geol. it., 41, 285-297. as c i o n e a. & ci n q u e a . (1995) l’età della tettonica trascorrente nell’appennino campano: il contributo dell’analisi geomorfologia. studi geol. cam., vol. spec., 1995/2, 41-52. ascione a. & cinque a. (1999) tectonics and erosion in the long term relief history of the southern apennines (italy). z. geomorphol., n.f. suppl. bd. 118, 1-16. ascione a., cinque a., santangelo n. & tozzi m. (1992) il bacino del vallo di diano e la tettonica trascorrente plio-quaternaria: nuovi vincoli cronologici e cinematici. studi geol. cam., vol. spec., 1 9 9 2 / 1, 201-208. basili r., galadini f. & messina p. (1999) the application of palaeolandsurfaces analysis to the study of recent tectonics in central italy. in: smith b.j., whalley w.b., warke p.a. (ed) “uplift, erosion and stability: perspectives on long term landscape development”, geol. soc. london, vol. spec., 162, 109-117. boenzi f., capolongo d., cecaro g., d’andrea e., giano s.i., la z z a r i m. & sc h i a t t a r e l l a m . (2004) 204 p. di leo et al. evoluzione geomorfologica polifasica e tassi di sollevamento del bordo sud-occidentale dell’alta val d’agri (appennino meridionale). boll. soc. geol. it., 123, 357-372. bo n a r d i g., am o r e f.o., ci a m p o g., de ca p o a p . , mi c o n n e t p. & pe r r o n e v . (1988) il complesso liguride auct.: stato delle conoscenze e problemi aperti sulla sua evoluzione pre-appenninica ed i suoi rapporti con l’arco calabro. mem. soc. geol. it., 41, 17-35. bu r r a t o p. & va l e n s i s e g . (2008) rise and fall of a hypothesized seismic gap: source complexity in the mw 7:0 16 december 1857 southern italy earthquake. bull. seismol. soc. am., 98, 139–148. cammarosano a., cavuoto g., danna m., de capoa p., de rienzo f., di staso a., giardino s., martelli l., nardi g., sgrosso a., toccaceli r.m. & valente a. (2004) nuovi dati sui flysch del cilento (appennino meridionale, italia). boll. soc. geol. it., 123, 253-273. cammarosano a., danna m., de rienzo f., martelli l., mi e l e f. & na r d i g . (2000) il substrato del gruppo del cilento tra il m. vesalo e il m. sacro (cilento, appennino meridionale). boll. soc. geol. it., 119, 395-405. cinque a., patacca e., scandone p. & tozzi m. (1993) quaternary kinematics evolution of the southern apennines. relationship between surface geological features and deep lithospheric structures. ann. geof., 36, 249-260. d ’ ar g e n i o b., pe s c a t o r e t. & sc a n d o n e p . (1973) schema geologico dell’appennino meridionale (campania e lucania). atti accad. naz. lincei, 183, 49-72. d’elia g., di girolamo p. & guida m. (1987) geological and petrological characters of some quaternary calcalkaline tuffites of cilento (southern italy). boll. soc. geol. it., 106, 699-716. de ge n n a r o m., fr a n c o e. & st a n z i o n e d . (1973) l’halloysite come prodotto di alterazione nelle vulcaniti campane e laziali. atti acc. sc. fis. e mat., napoli, 8, 13-35. de ri t a d., gi o r d a n o g. & mi l l i s . (1998) forestepping-backstepping stacking pattern of volcaniclastic successions: roccamonfina volcano, italy. j. volcan. geotherm. res., 80, 155-178. di le o p., gi a n o s.i., gi o i a d., ma t t e i m., pa p p a l a r d o, perri e., pescatore e. & schiattarella m. (2008) – primi dati sull’evoluzione geomorfologica, paleoclimatica e tettonica del bacino di sanza in appennino campano durante il quaternario. in: “studi di base sull’interazione tra clima, tettonica e morfoevoluzione in italia meridionale durante il quaternario”, a cura di f. boenzi, d. capolongo, s.i. giano e m. schiattarella. dibuono edizioni. villa d’agri (pz), 62-83. di niro a. & giano s.i. (1995) evoluzione geomorfologica del bordo orientale dell’alta val d’agri ( b a s i l i c a t a ). studi geol. cam., vol. spec. 1 9 9 5 / 2, 207-218. di ni r o a., gi a n o s.i. & sa n t a n g e l o n . ( 1 9 9 2 ) p r i m i dati sull’evoluzione geomorfologica e sedimentaria del bacino dell’alta val d’agri (basilicata). s t u d i geol. cam., vol. spec. 1992/1, 257-263. dixon, j.b. (1989) kaolin and serpentine group minerals. in: dixon, j.b., weed, s.b. (ed), “minerals in soil environments”, s.s.s.a., madison, wi, 467525. fo l k r . l . (1980) petrology of sedimentary rocks. hemphill, austin, texas, 1-182. giano s.i., lapenna v., piscitelli s. & schiattarella m. (1997) nuovi dati geologici e geofisici sull’assetto strutturale dei depositi continentali quaternari dell’alta val d’agri (basilicata). il quaternario, 1 0, 589-594. giano s.i. & martino c. (2003) assetto morfotettonico e morfostratigrafico di alcuni depositi continentali pleistocenici del bacino del pergola-melandro (appennino lucano). il quaternario, 16, 289-297. giano s.i., maschio l., alessio m., ferranti l., improta s. & schiattarella m. (2000) radiocarbon dating of active faulting in the agri high valley, southern italy. j. geodyn., 29, 371-386. gioia d. & schiattarella m. (2006) caratteri morfotettonici dell’area del valico di prestieri e dei monti di lauria (appennino meridionale). il quaternario, 19, 129-146. guida d., guida m., iaccarino g., metcalf g., vallario a., ve c c h i o v. & zi c a r i g . (1979) il bacino del mingardo (cilento): evoluzione geomorfologia, fenomeni franosi e rischio a franare. geol. appl. idrog., 14, 119-198. ho w e r j., es l i n g e r e.v., ho w e r m.e. & pe r r y e . a . (1976) mechanism of burial metamorphism of argillaceous sediment: 1. mineralogical and chemical evidence. geol. soc. am. bull., 87, 725-737. ka r n e r d.b., ju v i g n é e., br a n c a c c i o l., ci n q u e a . , russo ermolli e., santangelo n., bernasconi s. & li r e r l . (1999) a potential early middle pleistocene tephrostratotype for the mediterranean basin: the vallo di diano, campania, italy. global plan. change, 21, 1-15. ke l l e r e.a. & pi n t e r n . (1996) active tectonics. prentice hall, 1-338. la rocca s. & santangelo n. (1991) nuovi dati sulla stratigrafia e sull’evoluzione geomorfologica del bacino lacustre pleistocenico del fiume noce (basilicata). geogr. fis. din. quat., 14, 229-242. laurenzi m.a. (2008) relazione finale. rapporto interno, servizio di datazione campioni di roccia, c.n.r. istituto di geoscienze e georisorse, pisa, 12 pp. li p p m a n n pr o v a n s a l m. (1987) l’apennin meridional (italie): etude geomorphologique. these de doctorat d’etat en geographye physique, université d’aix-marseille, 1-730. marra f. (1998) evidenze di tettonica trascorrente alto pleistocenica al confine calabro-lucano: analisi morfostratigrafica e strutturale del bacino del mercure. il quaternario, 11, 201-215. martino c. & schiattarella m. (2006) aspetti morfotettonici dell’evoluzione geomorfologica della valle del melandro (appennino campano-lucano). il quaternario, 19, 119-128. mauro a. & schiattarella m. (1988) l’unità silentina di base: assetto strutturale, metamorfismo e significato tettonico nel quadro geologico dell’appennino meridionale. mem. soc. geol. it. , 4 1, 1201-1213. nesbit h.w. & young g.m. (1982) early proterozoic cli205evoluzione morfotettonica quaternaria del bacino intermontano ... mates and plate motion inferred from major element chemistry of lutites. nature, 299, 715-717. nesbit h.w. & young g.m. (1989) formation and diagenesis of weathering profiles. journ. geol., 9 7, 129-147. og n i b e n l . (1969) schema introduttivo alla geologia del confine calabro-lucano. mem. soc. geol. it., 8, 453-763. pa o n e a . (2004) evidence of crustal contamination, sediment, and fluid components in the campanian volcanic rocks. j.volcan. geoth. res., 138, 1-26. pe a r c e t.j. & ja r v i s i . (1995) h i g h r e s o l u t i o n chemostratigraphy of quaternary distal turbidites: a case study of new methods for the analysis and correlation of barren sequence. in: closs h., roeder d. & schmidt k. (eds) “alps, apennines, hellenides”, schweizerbart, stuttgart, 261-267. pu t i g n a n o m.l. & sc h i a t t a r e l l a m . (2008) s t r u t t u r a , esumazione ed evoluzione morfologica del nucleo mesozoico del monte motola (cilento, italia meridionale). boll. soc. geol. it., 127, 477-493. re n n e p.r., sw i s h e r c.c., de i n o a.l., ka r n e r d . b . , owens t. & depaolo d.j. (1998) intercalibration of standards, absolute ages and uncertainties in 40ar/39ar dating. chem. geol., 145, 117-152. sa n t a n g e l o n . (1991) evoluzione stratigrafica, geomorfologica e neotettonica di alcuni bacini lacustri del confine campano-lucano (italia meridionale). tesi di dottorato in geologia del sedimentario, università di napoli “federico ii”. 1-109. sc h i a t t a r e l l a m. (1996) tettonica della catena del pollino (confine calabro-lucano). mem. soc. geol. it., 51, 543-566. sc h i a t t a r e l l a m . (1998) quaternary tectonics of the pollino ridge, calabria-lucania boundary, southern italy. in: holdsworth r.e., strachan r.a. & dewey j.f. (ed), “continental transpressional and transtensional tectonics”. geol. soc., london, vol. spec., 135, 341-354. sc h i a t t a r e l l a m., be n e d u c e p., di le o p., gi a n o s . i . , gi a n n a n d r e a p. & pr i n c i p e c . (2005) a s s e t t o strutturale ed evoluzione morfotettonica quaternaria del vulcano del monte vulture (appennino lucano). boll. soc. geol. it., 124, 543-562. sc h i a t t a r e l l a m., di le o p., be n e d u c e p. & gi a n o s . i . (2003) quaternary uplift vs tectonic loading: a case-study from the lucanian apennine, southern italy. quaternary international, 101-102, 239-251. sc h i a t t a r e l l a m., to r r e n t e m.m. & ru s s o f . (1994) analisi strutturale ed osservazioni morfostratigrafiche nel bacino del mercure (confine calabrolucano). il quaternario, 7, 613-626. si n g h b. & gi l k e s r . j . (1992) an electron optical investigation of the alteration of kaolinite to halloysite. clays clay miner., 40, 212-229. st e i g e r r.h. & jä g e r e . (1977) subcommission on geochronology: convention on the use of decay constants in geoand cosmochronology. earth planet. sci. lett., 36, 359-362. tazaki k. (1978) micromorphology of halloysite produced by weathering of plagioclase in volcanic ash. in: mortland, v.c., veniale, v.c. (eds), 6 th int. clay conf., oxford, 415-424. turco e., maresca r. & cappadona p. (1990) la tettonica plio-pleistocenica del confine calabrolucano: modello cinematica. mem. soc. geol. it., 45, 519-529 zi e g l e r k, hs i e h j.c.c, ch a d w i c k o.a., ke l l y e . f . , hendricks d.m. & savin s.m. (2003) halloysite as a kinetically controlled end product of arid-zone basalt weathering. chem. geol., 202, 461-478. 206 14 maggio 200920 ottobre 2002 testo definitivo ricevuto il 23 settembre 2009 ms. received: may 14, 2009 final text received: september 23, 2009 p. di leo et al. available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 13 16 first results on the coastal changes related to local sea level variations along the puteoli sector (campi flegrei, italy) during the historical times pietro p.c. aucelli 1 , aldo cinque 2 , gaia mattei 1 , gerardo pappone 1 , michele stefanile 3 1 dipartimento di scienze e tecnologie, università degli studi di napoli parthenope, napoli, italy 2 dipartimento di scienze della terra, dell’ambiente e delle risorse, università di napoli federico ii, napoli, italy 3 dipartimento asia africa e mediterraneo, università l’orientale di napoli, napoli, italy corresponding author: g. mattei <gaia.mattei@uniparhtenope.it> abstract: puteoli coastal sector is located in the campi flegrei volcanic area, along the mediterranean coasts. this sector is rich in archaeological remains here used as sea-level markers useful to reconstruct the vertical ground movements affecting the cf area. marine surveys by means of an unmanned surface vessel equipped with geophysical instruments were carried out along the coastal sector to reconstruct the seabed morphology and to detect the submerged remains. by analysing geomorphological stratigraphic and archaeological data, the natural and anthropogenic landscape evolution of puteoli since the greek-roman period was evaluated. keywords: campi flegrei volcanic area; vertical ground movements; sea level markers; coastal changes 1. introduction the puteoli coast is located in the central part of campi flegrei caldera, an active volcanic system whose activity spans the last 50,000 years (de vivo et al., 2010 and reference therein). the caldera formation is mainly related to the campanian ignimbrite (ci, 37 ky) and the neapolitan yellow tuff (nyt; 15 ky) eruptions. this area is well known for bradyseism crisis characterized by alternating phases of intense uplift and subsidence of different duration. these vertical ground movements (hereinafter vgm) have produced strong modification in the coastal landscape since the early holocene. la starza marine terrace is the oldest silent witness of this volcanic behaviour. in fact, this marine terrace uplifted 30-40 m a.s.l. about 5 ky bp (di vito et al., 1999 and reference therein). instead, the more recent historical coastal modifications are mainly testified by the submerged structures of portus julius and by the lythophaga perforations on the marble columns of the macellum, the roman food market so-called serapis temple (morhange et al., 2006 and reference therein). despite the repeated modifications of the coastal landscape, this sector was extensively inhabited since the greek time, as testified by the town of dicearchia (531 bc) and by the neighbouring greek colony of kyme (the oldest in the western mediterranean, according to the ancient authors). however, it reached its maximum expansion during the roman period with the settlement of the roman colony of puteoli (194 bc), in the same site of the samian dicearchia, where a portorium was created during the second punic war. during this period, several human adaptations to bradyseismic crisis that affected the campi flegrei area were necessary (aucelli et al, 2017a, b and c). the studies have demonstrated that these vgms are not distributed uniformly all over the coast and new data can improve the knowledge on the phenomenon. in this short communication, we present the first result of a geoarchaeological study of the area located off the puteoli coast at the footslope of la starza marine terrace that still preserves several traces of coastal changes affecting campi flegrei area during the greekroman period due to vgms. 2. methods the greek-roman sea level changes and its effects on the coasts were deduced by interpreting depositional, erosional, biological and archaeological markers (vacchi et al., 2016 and references therein). in the first instance, the coastal sector was investigated by means of an unmanned surface vessel (usv) equipped with geophysical systems and underwater cameras as well as by direct underwater surveys. the usv was engineered by our research group to carry out integrated surveys with acoustical and optical methods at the same time in very shallow waters sectors (giordano et al., 2015; 2016). the analysis of the morpho-acoustic data allowed reconstructing the seabed morphology and the submersion of all submerged archaeological structures (mattei and giordano 2014; aucelli et al., 2016), as the pilae well distributed in the study area and probably dated by historical sources at augustan period (31 bc 14 ad). by https://doi.org/10.26382/aiqua.2018.aiquaconference mailto:gaia.mattei@uniparhtenope.it correcting the present submersion with respect to the indicative meaning (the elevation where the marker was built with respect to the palaeo-sea level, vacchi et al., 2016 and references therein), a new palaeo-sea level was deduced. three palaeo sea-level dated at greek-roman period were identified by reinterpreting a stratigraphic record close to the macellum (bellucci et al., 2006), taking into account the archaeological constrains provided by the restorations in this complex and by the portus julius construction. the main evolutive steps of the coastal sector in the same period were deduced by analysing highresolution morphologic (lidar, single beam and multibeam bathymetry) and geological data as well as by interpreting all submerged archaeological remains located in the study area. 3. results puteoli coastal sector has suffered short-lived subsidence phases in the historical times which greatly amplified the effects of the eustatic sea level rise (lambeck et al., 2011), producing the submersion of wide areas. the sea level deduced by studying the 74 submerged pilae, probably built not before the augustan age and well distributed off the southern puteoli coastal sector are an important evidence of a coastal retreat. as the more preserved pila has the top surface at -1 m bsl and considering an indicative range not higher than 2 m, the 1st century ad sea level was no lower than -3 m. a previous sea level at -6 m was deduced by the present submersion of the portus julius entry channel (passaro et al., 2013). in fact, this military port was hastily built in 37 bc, as a new resource for the war against the pirates, and abandoned in a few years for the rapid submersion of port facilities (todesco et al., 2014). we can deduce a subsidence about of 3 m that also explains the construction of the pilae as a coastal defence during the augustan age. two other relative sea level between the 1st century bc and 1st century ad were deduced by reinterpreting a stratigraphic record close to the famous macellum probably built in the i century ad, in a place where also a 1st mosaic floor was discovered, probably dated at mid-ii century bc by several authors (i.e. dvorak & mastolorenz, 1991; todesco et al., 2014). a sea level dated at the time of the construction of the first structures in this site was evaluated not higher than 8 m by bellucci et al. (2006), thanks to the anthropogenic deposits (with pottery fragments) on which the first floor lies. consequently, we have calculated a subsidence phase between ca. 150 bc and 37 bc about of 2 m. the 1st floor was totally buried by 2 m of coarse sands that can be interpreted as an antrophic intervention aimed at the construction of the 2nd marble floor. the last relative sea level at -2 m b.s.l. was deduced from the position of the second marble floor (probably dated at flavian age), the second in the sequence of the site, at 0.086 m a.s.l. (by supposing 2 m of indicative meaning). 4. discussion and conclusion this study has provided new data related to greekroman vertical ground movements affecting the campi flegrei, by means of a precise detection of four local palaeo-sea level indicators. in the first instance, a new palaeo-sea level probably dated not before the augustan period (camodeca, 1994) was evaluated by sensing the underwater archaeological landscape of this sector by using a usv with geophysical instruments. the corresponding coastline position at that time was reconstructed by integrating the geophysical, geomorphological and archaeological interpretations (figure 1). thanks to these interpretations, a subsidence occurred between 37 bc and the 1st century ad was evaluated for the first time, by overlaying the sea level data deriving from the submersion of the defence structures (pilae) here studied with that of portus julius (passaro et al., 2013) built several years before the pilae. in the second instance, the reinterpretation of the stratigraphic record described by bellucci et al. (2006) allowed us to evaluate the two other palaeo-sea level as well as the corresponding coastline positions (figure 1). two subsidence phases deriving from these interpretations were obtained: one between ca. 150 bc and 37 bc, and another during the of 1st century ad. taking into account that the eustatic sea level during this time lapse was constantly at -1.1 m b.s.l. (aucelli et al., 2017; lambeck et al., 2011), the subsidence of about 3 m can be ascribed to a volcano tectonic ground movement. the vertical ground movements of metric entity here tentatively proposed between 2nd century bc and 1st century ad, can be totally ascribed to a volcanotectonic origin, taking into account that the eustatic sea level rise during this time lapse ranged between -1.38 m and 1.06 m (aucelli et al., 2017; lambeck et al., 2011). taking into account that the eustatic sea level rise during this time lapse ranged between -1.38 m and 1.06 m (aucelli et al., 2017; lambeck et al., 2011), these vertical ground movements of metric entity can be totally ascribed to a volcano-tectonic origin. at that time, this study provides a first evaluation of the subsidence effects on the campi flegrei coastal landscape and coastal settlements during the historical times, thanks to the reconstruction of the local sea level variations between the 2nd century bc and the 1st century ad (figure 1). in conclusion, the historical coastal evolution of the central part of campi flegrei caldera has been characterized by a coastal retreating about of 150 m. the coastline positions here reconstructed between 200 bc and 14 ad have enabled us to assess this trend. this study has demonstrated as the puteoli coastal landscape was strongly modified by volcano-tectonic movements inducing fast sea level variations. these coastal changes were reconstructed by overlaying geomorphological archaeological and stratigraphic interpretations in order to describe the interaction between landforms evolution and human adaptations. moreover, the ongoing acquisition of new archaeological data could slightly vary some geochronological constraints related to the macellum construction phases. 14 aucelli p.p.c. et al. 15 fig. 1 a) relative sea level curve since the greek-roman times; b) 3d landscape with the roman structures nowadays submerged and the coastline positions between the 2nd century bc and 1st century ad. historical evolution and sea level changes of puteoli coastal sector references aucelli p.p.c., cinque a., mattei g., pappone g., stefanile m. (2017) coastal landscape evolution of naples (southern italy) since the roman period from archaeological and geomorphological data at palazzo degli spiriti site. quaternary international, in press. doi: 10.1016/j.quaint.2017.12.040 aucelli p.p.c., cinque a., mattei g., pappone g. (2017) late holocene landscape evolution of the gulf of naples (italy) inferred from geoarchaeological data. journal of maps, 13 (2), 300-310. aucelli p.p.c., cinque a., mattei g., pappone g., rizzo a. (2017) studying relative sea level change and correlative adaptation of coastal structures on submerged roman time ruins nearby naples (southern italy). quaternary international, doi: 10.1016/j.quaint.2017.10.011 aucelli p.p.c., cinque a., mattei g., pappone g. (2016) historical sea level changes and effects on the coasts of sorrento peninsula (gulf of naples): new constrains from recent geoarchaeological investigations. palaeogeography, palaeoclimatology, palaeoecology, 463, 112-125. aucelli p.p.c., cinque a., giordano f., mattei g. (2016) a geoarchaeological survey of the marine extension of the roman archaeological site villa del pezzolo, vico equense, on the sorrento peninsula, italy. geoarchaeology, 31 (3), 244-252. bellucci f., woo j., kilburn c. r., rolandi g. (2006) ground deformation at campi flegrei, italy: implications for hazard assessment. geological society, london, special publications, 269(1), 141157. camodeca g. (1994) puteoli porto annonario e il commercio del grano in età imperiale. publications de l'école française de rome, 196(1), 103-128. de vivo b., petrosino p., lima a., rolandi g., belkin h. e. (2010) research progress in volcanology in the neapolitan area, southern italy: a review and some alternative views. mineralogy and petrology, 99(1-2), 1-28. di vito m., isaia r., orsi g., southon j., de vita s., d’ antonio m., pappalardo l., piochi m. (1999) volcanism and deformation since 12,000 years at the campi flegrei caldera (italy). journal of volcanology and geothermal research, 91(2), 221-246. dvorak j.j., mastrolorenzo g. (1991) the mechanisms of recent vertical crustal movements in campi flegrei caldera, southern italy. geological society of america, 263, 1-47. giordano f., mattei g., parente c., peluso f., santamaria r. (2015) microvega (micro vessel for geodetics application): a marine drone for the acquisition of bathymetric data for gis applications. the international archives of photogrammetry. remote sens. spatial inf. sci., 40 (5), 123-130. giordano f., mattei g., parente c., peluso f., santamaria r. (2016) integrating sensors into a marine drone for bathymetric 3d surveys in shallow waters. sensors, 16 (1), 41. lambeck k., antonioli f., anzidei m., ferranti,l., leoni g., scicchitano g., silenzi s. (2011) sea level change along the italian coast during the holocene and projections for the future. quaternary international, 232(1-2), 250-257. mattei g., giordano f. (2015) integrated geophysical research of bourbonic shipwrecks sunk in the gulf of naples in 1799. j. archaeol. sci. rep. 1, 64-72. morhange c., marriner n., laborel j., todesco m., oberlin c. (2006). rapid sea-level movements and non eruptive crustal deformations in the phlegrean fields caldera, italy. geology, 34, 93-96. passaro s., barra m., saggiomo r., di giacomo s., leotta a., uhlen h., mazzola s. (2013) multiresolution morpho-bathymetric survey results at the pozzuoli-baia underwater archaeological site (naples, italy). journal of archaeological science, 40(2), 1268-1278. todesco m., costa a., comastri a., colleoni f., spada g., quareni f. (2014) vertical ground displacement at campi flegrei (italy) in the fifth century: rapid subsidence driven by pore pressure drop. geophysical research letters, 41(5), 1471-1478. vacchi m., marriner n., morhange c., spada g., fontana a., rovere a. (2016) multiproxy assessment of holocene relative sea-level changes in the western mediterranean: sea-level variability and improvements in the definition of the isostatic signal. earth science reviews, 155, 172-197. 16 aucelli p.p.c. et al. ms. received: may 8, 2018 final text received: june 3, 2018 available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 34 (1), 2021, 75-88 preliminary data on the middle pleistocene site of lunel-viel i (hérault, france). jean-philip brugal 1 , carla giuliani 1 , philippe fosse 1 , jean-baptiste fourvel 1 , pierre magniez 1 , maxime pelletier2, antigone uzunidis1 1 aix marseille université, cnrs, minist. culture, umr 7269 lampea, aix-en-provence, france. 2 archeology, history, culture and communication studies, faculty of humanities, university of oulu, oulu, finland. corresponding author: jean-philip brugal <brugal@mmsh.univ-aix.fr> abstract: the archeo-paleontological site of mas des caves at lunel-viel (hérault), in southeastern france, is an important site, well-known for its diversified vertebrate remains dated to the second half of the middle pleistocene. following a brief presentation of the historical context, preliminary data, collected through new research, are discussed, focusing on the general fossil distribution and new analyses of leporids, carnivores, rhinocerotids and cervids to better define their taxonomy, paleoecology and biochronology. keywords: southeastern france, lunel-viel, middle pleistocene, mammals, paleontology, ecometry, biochronology. 1. introduction the caves of mas des caves in lunel-viel, between montpellier and nîmes, in languedoc (south-east france) opens in a miocene carbonate limestone, unlike many of the cavities in the south of france that developed in secondary jurassic and cretaceous limestones. located in the plains of bas-languedoc, subject to the mediterranean climate, the landscape consists of slopes and small hills rounded off at their summit and covered with alluvium (quartz and limestone pebbles paleorhône) (fig. 1). the site is at low altitude (ca. 50 m a.s.l.) and ca. 9 km from the mediterranean coast, bordered by brackish or salt ponds. in recent years, a new research program has aimed to carry out both new fieldwork and new studies on the fossil material recovered during previous excavations (led by bonifay e., from the 1960s to the early 1980s), using modern approaches and methods in order to redefine the paleoecology, taphonomy, climate and paleoenvironment, as well as to improve the chronology of the deposits. this paper presents the preliminary data on the composition and distribution of the material as well as information on the studies recently performed on the leporid, carnivore, rhinocerotid and cervid taxa. 2. geological and historical background in the 19th century, during the exploitation of a quarry of miocene carbonate limestone (mollasse in french), a small opening was discovered revealing the first cave (named lv i). this is a relatively straight gallery, 150 m long, 10-12 m wide and nearly 6 m high (variable according to the different sectors of the cavity) oriented ne-sw. other narrower galleries (lv ii and iii) run parallel to lv i. this discovery at the beginning of the 19th century was the focus of the first fieldwork from 1824 to 1827 by marcel de serres, professor at the university of montpellier work which was subsequently published in monographs (serres et al., 1828, 1839). the site fell into oblivion until 1962, when eugène bonifay (french national scientific research centre; cnrs) conducted new research in the gallery during almost 20 years, until the beginning of the 1980s. this led him in 1971 to discover the sinkhole (doline) and cave n° 4 (lv iv). the latter is a gallery (approx. 90 m long), an extension of lv i, rich in speleothems, unlike lv i. lv iv was not excavated (but fossils were collected on the surface) and was closed in 1974. it remains to date inaccessible and intact. it is one single karstic network and the collapsed vault (sinkhole: 50m long by 20m wide) is the original entrance to lv i and iv (bonifay, 1968, 176a; bonifay & bonifay, 1965; bonifay & combier, 1984). the filling is constituted of a base of finely varved red clays at the base of the sequence (approx. 6 m thick) on which deposits of pebble, gravel coated in a matrix of sands and clayey silts, develop. they come from the superficial formations overhanging the site, rhodanian alluviums (quartz, quartzite, flint, metamorphic, limestone), that leach into the cavity. their thickness varies from 2 m downstream to nearly 5 m towards the sinkhole (with a particle size gradient). fourteen layers have been distinhttps://doi.org/10.26382/amq.2021.08 76 brugal j.p. et al. minea, lutra sp., meles thorali spelaeus and pinnipeds. herbivores are represented by eight taxa: bos primigenius trochoceros, cervus elaphus, euctenoceros mediterraneus, capreolus cf. sussenbornensis, sus scrofa, dicerorhinus etruscus (= stephanorhinus etruscus: see below), equus mosbachensis palustris and equus hydruntinus minor. several taxa (evolutive stage expressed at ssp. level) were identified for the first time in this deposit and are important for the biochronological framework of western europe large mammal associations. wolf and hyena, with great abundance of coprolites (album graecum), equines, bovines and deer are the most frequent taxa. these taxa are indicative of a rather temperate paleoenvironment (interglacial type) and link the entire deposit to the second half of the middle pleistocene (“mindel-riss”, bonifay, 1968, 1976a, 1989). mesoand micro-vertebrates are relatively abundant: guished. 3. short overview of the 20th century studies several studies were carried out in the fossiliferous deposits of lunel-viel i. they contain rich archeological material associated with very abundant paleontological remains (fauna, flora). large mammals are well represented, often with complete skulls with mandibles, frequent long bones, often complete, and scarce short bones and appendicular elements (bonifay, 1971, 1973, 1980, 1991; brugal, 1985; eisenmann et al., 1985; noury, 1997). nearly 14 species of carnivores are present: cuon priscus, canis lupus lunellensis, vulpes vulpes, lynx cf. pardina and lynx spelaea (see discussion below), panthera (leo) spelaea, panthera pardus, crocuta spelaea intermedia, hyaena prisca, ursus deningeri, mustela palerfig. 1 geographical location of the caves of mas des caves (courtesy l. bruxelles). calcaires crétacés: cretaceous limestone; colluvions anciennes: old colluviums; alluvions rhodaniennes: rhodanian alluviums (quartz, quartzite, flint, metamorphic, limestone); calcaires blanc burdigaliens: white burdigalian limestone; conglomérat eocène: eocene conglomerate. 77 insectivores (talpa, sorex), leporids (oryctolagus cuniculus lunellensis, donard, 1982), chiropters, rodents [microtus brecciensis, apodemus sylvaticus, eliomys quercinus, pliomys lenki, pitymys duodecimcostatus, microtus agrestis (jeannet, 1976)], birds (33 taxa, mourerchauvire, 1975), reptiles (terrestrial tortoise: testudo sp., ophidia indet.), amphibians (rana), fish and gastropods. the flora is known through the remains of hackberry seeds celtis australis and charcoals cercis siliquastrum, quercus sp. (det. j.l. vernet). the study of several bone splinters, found with other faunal remains has suggested the possible use of these bones by hominins (bonifay, 1976b, 1986), but also suggests that these caves were occupied by carnivores that used them as dens or lairs, especially the cave hyena (diez, 1986; fosse, 1992, 1994, 1996). the fossil population of crocuta has served to establish a chart of age classes based on dental replacement and wear of the mandibular series (brugal et al., 1997). lithic artifacts (flint, quartzite or quartz) and the possible existence of structures, in particular hearths, attest to the presence of humans (bonifay, 1981, 1989; le grand, 1987, 1994). the tools are characterized by heavy artefacts (such as chopping tools), but also by blades and scrapers, and levallois debitage has also been observed. this industry was attributed to the acheulean mediterranean facies (bonifay, 1968, 1976a, 1989). 4. short overview of the 20th century studies in the 21st century, there have been several research projects which have included both fieldwork (excavations since 2019, dir. j.p. brugal) and intensive studies of the old collections (stored at the musée national de préhistoire/ mnp, les eyzies-de-tayac), some partly in the form of doctoral theses. these studies have revisited certain taxonomic points, and in fine clarified other taphonomical and geochronological issues. two new genera have been identified, notably among the lunel-viel material, one cervid haploidoceros (replacing euctenoceros, croitor et al., 2008) and one tortoise described as eurotestudo (lapparent de broin et al., 2006). the new excavations follow all the procedures now in place for modern fieldwork, adapted to a cave environment that appears as a simple elongated gallery, ‘tube’-type, using numerical and 3d support (photogrammetry, lasergrammetry, tacheometry) (fig. 2). efforts are made to include the new data in those collected during the ancient excavations. 4.1. nature and distribution of remains (e. bonifay collection) the information recorded in the field-books during the excavations of e. bonifay, such as the square, level, coordinates and the initial identification of the remains (bone with anatomical and taxonomical data, lithic with raw material), has been analyzed. the checking of the identifications is currently in progress. all items are recorded in a database. the frequency, (number of identified specimens nisp; i.e., splinters and shaft fragments excluded), has also been reported as it reflects the faunal assemblages. among the herbivores, cervids dominate, followed by equids and bovids (fig. 3). hyenids are over-represented among the carnivorans and include two species (see below). two new species have been recently recorded and added to the faunal list: one large-sized cervid megaloceros (fig. 4) and an indeterminate proboscid; the latter had already been identified by de serres et al. (1839) but was absent from the bonifay excavation records. the high frequency of reptile remains (essentially chelonid) is also preliminary data on the middle pleistocene site of lunel-viel i (hérault, france) fig. 2 3d view of sector 5 of lv i, the sector nearest to the naturally clogged entrance (at the bottom of the photo). note the presence of pillars used to support the vault (in this case, only the base) © l. pascal. noteworthy. furthermore, there are more than 750 coprolite remains with typical hyena morphology; their presence is an important criterion confirming the use of the cavity by this group of carnivorans. the database combines different information and the distribution of the whole sequence is given here by categories (fig. 5): identifiable bone, coprolites and lithic objects represent a total of 7,015 items. faunal remains are the most abundant (ca. 83%) and most of this material (70%) predominantly comes from the median levels of the sequence, especially level 9 followed by levels 5-7. faunal and coprolite remains occur in every part of the cave, whereas the lithics are mainly distributed on the nw side of the gallery and are closer to the entrance. there is a clear difference in the distribution of bones versus coprolites. in the future, such spatial zonation needs to be further studied, in particular in relation to the origins of bone assemblages interpreted as the main result of a hyena den accumulation (fosse, 1994, 1996) and to better understand the role of human groups in the cave. 78 brugal j.p. et al. 4.2. the leporid material a total of 364 remains are attributed specifically to the european rabbit (oryctolagus cuniculus) and correspond to at least 44 individuals. this species is the only one of its genus to have occupied western europe from the middle pleistocene. the european rabbit has been found in 700-600 ky old deposits in southwestern spain, the cúllar de baza (andalusia) and benisants (valencia) deposits (lópez-martínez, 1989; pelletier, 2018), and in southeastern france at balaruc 1 (hérault) and the cave of l'escale (bouches-du-rhône) (pelletier, 2018). in more recent periods the number of fossil occurrences increases significantly in southeastern france (e.g., caune de l’arago, terra amata, lunel-viel i, igue des rameaux, orgnac 3, baume baunne, aubais, lazaret and les cèdres). during the middle pleistocene, three subspecies of oryctolagus cuniculus have been identified: o. c. lunellensis (donard, 1982), defined precisely through the lunelviel i material, o. c. grenalensis (donard, 1982) and o. c. baumensis (crégut-bonnourre, 1995), described respectively from southwestern and southeastern french populations. osteometric analysis of the lunel-viel i population has revealed obvious differences with other populations in the region during the middle pleistocene (pelletier, 2018). indeed, the rabbits of lunel-viel i are characterized by a very small body size compared to those of terra amata (mis 10), orgnac 3 (mis 9), igue des rameaux-amont and -aval (mis 9), baume bonne (mis 7), aubais (mis 6), lazaret (mis 6) and les cèdres caves (mis 6). although the data are relatively dispersed in time and space, the body size of populations in southeastern france has significantly varied over time. this can be explained by the fact that in western europe, there is a strong correlation between the body size of rabbits and geographical location and local environmental conditions (sharples et al., 1996; callou, 2003; davis, 2019; pelletier, 2019). populations are distributed according to several known factors, including latitude and temperature (which are often directly related). the small body size of lunel-viel i individuals would then indicate relatively favorable climatic conditions. the third lower premolar (p3) analysis, a tooth commonly used to distinguish leporid species, is characterized by a subtriangular occlusal surface. the entoconid and the paraflexid are relatively marked and the protoflexid shows an angle of approximately 90°. the lingual and vestibular anteroconids are similar in size and shape, separated by a relatively deep anteroflexid. the 2d geometric morphometrics study of this tooth in lunel-viel i rabbits revealed greater morphological similarities with the orgnac 3 and igue des rameaux populations (mis 9) than with those of terra amata (mis 10) or baume bonne, vaufrey, aubais, lazaret and les cèdres cave (mis 7 and 6) (pelletier, 2018). the rabbits of lunel-viel i were initially identified as a new subspecies, o. cuniculus lunellensis, in particular due to their very small stature and large dental dimensions (donard, 1982). however, the reduction or increase in the size of dental and postcranial elements is not a reliable criterion for specific (or subspecific) identification but rather is to be linked to local conditions. in this case, this reflects very mild climatic conditions (i.e., interglacial), close to those currently observed in the region. in addition, the fig. 3 pie-chart (% nisp) of the main mammal groups identified in lunel-viel i (ursids, microfaunas and coprolites excludfig. 4 megaceros maxillary from lunel-viel i (9#23124), first identified by s. madelaine (mnp) photo j.p.b. preliminary data on the middle pleistocene site of lunel-viel i (hérault, france) 79 overall morphology of the p3 shows strong phenotypic similarities with other rabbit populations from mis 9, and this may be an important point when detailing the chronology of the deposit. 4.3. the carnivoran material the carnivorans of lunel-viel i are a muchdiversified guild (fig. 6). the hyenids and the canids, represented by crocuta spelaea intermedia, hyaena prisca, and c. lupus lunellensis (bonifay, 1971), dominate the medium-to-large-sized predators. when hyaena remains are less common, crocuta is dominant. the medium-sized wolf sample is composed of about 213 crania, mandible and postcranial remains representing at least 18 individuals and corresponding to an evolutionary stage in the wolf lineage, characteristic of middle pleistocene times (boudadi-maligne, 2010). the remains of the canid genus cuon underwent biometrical analysis to improve the definition of this lineage in order to refine its biochronology (brugal & boudadi-maligne, 2011). in the proposed phyletic scheme, the dhole material from lunel-viel is identified as c. priscus fossilis. among the hyenids, hyaena prisca has been considered so far as an ancestral form of the extant striped hyena hyaena hyaena (kurten, 1968; werdelin & solounias, 1991; turner, 1990; turner et al., 2008), although recent research suggests a potential phyletic relationship with the extant brown species parahyaena brunnea (arribas & garrido, 2008; brugal et al., 2012). hyaena prisca is present in some pleistocene sites especially in southern europe and seems more characteristic of the middle pleistocene (kurten, 1968; brugal et al., 2020). this species is never abundant in the sites, except in the early late pleistocene site of furninha in portugal where this taxon persists (cardoso, 1996; brugal et al., 2012). it was first institued by de serres, (1828) based on the lunel-viel material (figs. 6-7). its main dental morphological features are (figs. 6-7): a vestigial m1, less thicker premolars than in crocuta while the m1 has a stronger talonid and a shorter trigonid (paraconid + protoconid) flanked posteriorly by a prominent metaconid, behind the protoconid (de serres et al., 1938; kurten, 1956; bonifay, 1971). the relative size of the premolars and the talonid are more developed than in crocuta, as seen in the extant scavenging specialized brown and striped hyenas. h. prisca was probably a scavenging hyena well equipped for bone-cracking activities. felids are usually rarely found in quaternary sites, probably due to their social (solitary) and dietary behaviors. however, the fossil cave lynx from lunel-viel is represented by 38 remains from 5 individuals which, along a few other pleistocene series (escale, campefiel, observatoire), are quantitatively important. fosse et al. (2020, 2021) redefined its taxonomical status through biometrical and morphological reanalyzes, suggesting that the cave lynx could be an ancestral (pleistocene) sub-specific form of the extant iberian lynx, lynx pardinus spelaeus. accordingly, almost all the pleistocene lynxes from the mediterranean area should now be considered as belonging to this (sub-)species, while lynx lynx only appears at the end of the last glacial (fosse et al., in prep; mecozzi et al., 2021). finally, this new assessment of the collection confirms the presence of a marine mammal, cf. phoca sp.?, through three teeth (one canine, one upper incisive and one pm/m). the presence of seal remains within a continental paleontological sample in a carnivoran den suggests the exploitation of marine environments and the fig. 5 density map and global distribution of faunal remains (left), coprolites (middle) and lithic material (right) at lunel-viel i. the top on the image is close to the original entrance of the cavity (sinkhole). 80 brugal j.p. et al. fig. 6 carnivore remains from 2019 and 2020 excavations at lunel-viel i (except holotype h. prisca of m. de serres, top right). scale: 1cm. photos p.f. and mandible h. prisca lv1-20 s21-a23 by jpb. seashore by predators such as hyenas. these predatorprey interactions between seals and hyenas are wellknown from an extant context in southern africa, particularly brown hyenas which live along the namib seashore (for more details on ecology and taphonomy see wiesel, 2006; kuhn, 2011; fourvel, 2012). 4.4. the rhinocerotid material the rhinoceros remains of lunel-viel were first attributed to rhinoceros minutus by de serres et al. (1838) due to misidentification of the dental remains. rhinoceros minutus cuvier, 1822 is a small oligocene rhinoceros and many small specimens have been attributed to this species during the 19th and the beginning of the 20th centuries (viret, 1961). the lunel-viel rhinoceros’ teeth were finally ascribed to a juvenile individual; the same authors in fact reassigned this taxon to r. africanus blumenbach, 1799 (gervais et de serres in edwards et al., 1846), synonymous with diceros bicornis, thus arguing that the specimens from lunel-viel were not distinguishable from the black rhino of the cape (southern africa). in 1849, gervais proposed the creation of a new species, rhinoceros lunellensis (de la rive et al., 1849), related to r. etruscus (gervais, 1867). in 1854, duvernoy associated the lunelviel rhinoceros with rhinoceros protichorhinus. this species can be considered synonymous to stephanorhinus kirchbergensis (depéret, 1923). however, this idea was not accepted and new studies were carried out. in 1867, dawkins proposed the attribution of these remains to rhinoceros leptorhinus according to an idea already mentioned by de blainville (gervais, 1867). the definition of this taxon posed many problems at the time since it actually corresponded to two distinct taxa described by cuvier (1822) and owen (1846). in the same year, lartet (1867) associated the rhinoceros of lunel-viel with rhinoceros merckii. finally, falconer, after establishing in 1860 the new taxon dicerorhinus hemitoechus, noticed the great resemblance between the rhinoceros of gower caves and the one from lunel-viel (falconer & murchison, 1868). following the excavations of the 1960s, new studies on the rhinoceros were carried out by bonifay (1973) who attributed this taxon to dicerorhinus etruscus. later, guérin (1973; 1980), followed by lacombat (2003), classified these specimens as dicerorhinus hemitoechus without justifying this change, classification possibly made on the basis of the plates published by de serres (1838) and falconer (1868). the lunel-viel rhino material was recently reexamined (uzunidis-boutillier, 2017). it is represented by a total of 66 bone and dental remains: 56 from lv i, nine from lv iv. all skeletal parts are represented, although the smallest bones (carpals, tarsals and sesamoids) are rare. two distinct morphologies could be observed on the talus which is the most abundant post-cranial element (fig. 8). they concern the specimens from lv i (levelnumber: 9#2554; 9#2740; 3#3117; 2#4023; 9#9028; #10089) and lv iv (#14079). specimen 10089: in this specimen the pulley is wide showing asymmetrical lips due to the steep slope of the inner lip, while on the other six, the pulley is narrower but asymmetrical and deep. the pulley is limited downwards by an overhang followed by a depression. on the medial face, the distal tuber is well separated, and is located in the middle of the face, above the distal edge. on the distal face, the anterior edge of the joint is concavo-convex. the facet for the cuboid is very elongated and its anterior edge protudes. additionally, the median height of the talus helps discriminate between different stephanorhinus species (lacombat, 2003). in this specimen the talus is very high, such as in the s. kirchbergensis specimens from taubach or ehringsdorf (kahlke, 1975; 1977) (fig. 8). specimens 2554, 2740, 3117, 4023, 9028, 14079: on the medial face, the transition between the tuber, placed more posteriorly, and the body is more progressive. on the distal face, the anterior edge of the joint is fairly straight. the facet for the cuboid is offset but is as long as that of the navicular. in height, these tali are more developed than the ones from s. etruscus or s. hundsheimensis and similar to the arago talus of s. hemitoechus (lacombat, 2003) (fig. 8). given these two distinct morphologies (fig. 9), it is possible there are two species of rhinoceros in lunel-viel. specimen #10089 could correspond to stephanorhinus preliminary data on the middle pleistocene site of lunel-viel i (hérault, france) 81 fig. 7 upper and lower dental features of h. prisca from lunelviel. photos j.b. fourvel. fig. 8 biplot comparing the medial height and the maximum transverse diameter of the talus from several cohorts of stephanorhinus. references in table 1. kirchbergensis, whereas the others are closer to stephanorhinus hemitoechus, in accordance to the already known morphological descriptions for these taxa (guérin, 1973; 1980; 2010; antoine, 2002). the metric features also confirm these attributions (tab. 1; fig. 8). 4.5. the cervid material cervids are mainly represented by two species: cervus elaphus and haploidoceros mediterraneus, which dominate the osteological series (mni of 158, fosse, 1996) and are associated with a few roe and giant deer remains. the latter’s fossil material has been recently established as a new genus (croitor et al., 2008), replacing the previous identification of euctenoceros (bonifay, 1967). a study on all the mandibular material from the lv i deposits gives a first glimpse of the age structure and mortality curve for these two species. the age estimation methods follow published studies and the dental wear chart proposed for modern red and fallow deer, based on both tooth replacement and the use-wear of the occlusal surface (e.g., chapman & chapman, 1970; riglet, 1977; brown & chapman, 1991a, b, c; magniez, 2010; bowen et al., 2016). six age-categories have been distinguished: j1 for first year individuals, j2 for second year individuals, a1 for individuals aged between ca. 30 and 60 months, a2 for those aged between ca. 60 to 80 months, aa for the older 82 brugal j.p. et al. tab. 1 measurements of the talus of s. kirchbergensis and s. hemitoechus from lunel-viel compare to several cohorts of stephanorhinus. 1: maximum transverse diameter of the bone (guérin, 1980); 2: medial height (mazza, 1988); 3: distal anterior-posterior articular diameter (guérin, op. cit.); 4: distal articular transverse diameter (guérin, op. cit.); 5: transverse diameter between the edges (guérin, op. cit.); 6: maximum distal transverse diameter (guérin, op. cit.); 7: lateral height (mazza, op. cit.); 8: maximum distal antero-posterior diameter (mazza, op. cit.); 9: height of the medial trochlea (mazza, op. cit.); 10: medial anterior-posterior diameter (guérin, op. cit.); 11: height of lateral trochlea (fortelius et al., 1993); 12: maximum height of the bone (guérin, op. cit.); 13: anterior-posterior lateral diameter. (1): uzunidis-boutillier, 2017; (2): lacombat, 2003; (3): guérin, 1973; (4): alférez & inigo, 1990; (5): kahlke, 1977; (6): kahlke, 1977. individuals, between 80 and 120 months, then ata for the very old adults (over 120 months old). from the bonifay e. excavations, 55 mandibular series of c. elaphus, more or less complete, were analyzed for a minimum number of individuals (mni) of 41 and 100 mandibular series for h. mediterraneus for a mni of 62. most of the fossil material comes from level 9. moreover, the observation of the mandibles of the young and prime adults suggests seasonality factors, especially for the red deer remains where such material is more frequent. the mortality profiles are relatively similar for the two taxa, prime-adults and adults dominate (fig. 10). all age categories are represented, and such a pattern would indicate a predatory curve as observed for large carnivores and human groups (e.g., stiner, 1990, 2012). according to the context of the cave, the bone assemblages recovered and its interpretation as a hyena den (fosse, 1994, 1996), such cervid accumulation could be the result of hunting or scavenging behaviors as those observed in modern hyenas (kruuk, 1972). according to eruption and tooth-wear patterns, red deer deaths would occur in summer and fall, whereas the mediterranean deer data are indicative of acquisition during the winter period. the mortality profiles are relatively similar for the two taxa, prime-adults and adults dominate (fig. 10). all age categories are represented, and such a pattern would indicate a predatory curve as observed for large carnivores and human groups (e.g., stiner, 1990, 2012). according to the context of the cave, the bone assemblages recovered and its interpretation as a hyena den (fosse, 1994, 1996), such cervid accumulation could be the result of hunting or scavenging behaviours as those observed in modern hyenas (kruuk, 1972). according to eruption and tooth-wear patterns, red deer deaths would occur in summer and fall, whereas the mediterranean deer data are indicative of acquisition during the winter period. a complementary approach, microwear analysis, was applied to the cervid teeth material of the two species (n=36 teeth for c. elaphus and n=86 for h. mediterraneus) and of giant deer megaloceros (n=1). the material concerns the lunel-viel i assemblage and was separated into upper (lv i sup) and lower (lv i inf) units of deposit. some teeth come from lv iv. the micro-wear analysis followed the method described by solounias & semprebon (2002) and semprebon et al. (2004). observations were made on a standard surface of 0.16 mm² from the paracone of the upper teeth and the protoconid of the lower teeth of adult individuals. there is a clear difference between the species (fig. 11) but there is a homogeneity for the three sets of cervus teeth observed in terms of the mean number of scratches and pits. the mean number of scratches (ns= 16.67 to 17.25) indicates a mixed-feeder diet of both monocotyledonous and dicotyledonous grasses. megaloceros (ns=18.5) appears closer to the grazers but is still within the range of the red deer samples. haploidoceros is very distinct and the ns mean of its three samples is lower, corresponding to a browser adaptive diet. this mediterranean cervid was probably flexible and use-wear analysis on the specimens from the spanish site of cova del rinoceronte indicates a more mixed-feeder diet behavior (rivals et al., 2016). the two dominant cervid species present at lunel-viel do not occupy the same ecological niche and, consequently, the accumulation of their remains in the cave seems to be seasonal. further use-wear analysis on the equids and bovids from lunelviel was also performed (uzunidis, 2020), indicating respectively grazer and browser diets. thus, the hypothesis proposed by bonifay, (1980) that this form of equus inhabited a wetland biotope, justifying the subspecies name palustris, can be dismissed. the paleobiodiversity present in the lunel-viel associations suggests a relative high competition for vegetal resources among herbivores, which would push a medium-size cervid as haploidoceros towards a more vegetated landscape and turn it into more of a browser (dicot plants). 5. conclusive remarks the caves of mas des caves at lunel-viel (hérault) in southern france are exceptional middle pleistocene sites. they have yielded an important rich and wellpreserved fossil record, which has become the foundation for a new systematic framework helping to redefine evolutionary forms. the renewed interest in these caves has mobilized a large interdisciplinary team of specialists in geology, sedimentology (including archaeomagnetism), geochronology (osl, esr/u/th, be/al, racemization), animal and vegetal palaeontology, paleoecology, ecometry, taphonomy, archaeology, traceology, biochemistry (isotopes), framed within systematized photographic or lasergrammetric supports. this preliminary work already presents several results. first, thanks to the rich fossil series of wolf and leporids, it has been possible to better establish their morphological stage and their evolutionary dynamics. second, the taxonomic status of lynxes and rhinocerotids has been redefined. third, new species have been identified or confirmed: megacerine deer, proboscidean, pinniped. fourth, the analysis of dental mesoand micro-wear provided new data on the paleodiet of ungulates and on middle pleistocene environments in the region. finally, complementary taphonomic studies, which included the old collections, were also performed and helped explain the structure s.l. and condition of the biological and anthropic assemblages. the future prospects and research for this important pleistocene site in western europe are still many. further studies are needed, especially to understand the role and actions of humans. currently, it appears that the bone accumulation was mainly the consequence of non-human predator activity. notwithstanding, human activities cannot preliminary data on the middle pleistocene site of lunel-viel i (hérault, france) 83 fig. 9 rhinoceros talus from lunel-viel (mnp). photos a. uzfig. 10 age mortality profile for the two most represented cervid species, cervus and haploidoceros, at lunel-viel i. be completely dismissed as demonstrated by the presence of various lithic industries and possible anthropic structures (hearths). these can be attributed to an early phase of the middle paleolithic. from a biochronological and paleoenvironmental point of view, the faunal assemblage is clearly temperate and the deposit could be ascribed to mis 9 (e.330-300 kya) or to mis 7 (e.240-186 kya). acknowledgements the authors wish to warmly express their gratitude to drac occitanie, lampea, appam, irn 0871 cnrsinee, institut arkaia (amidex/amu), and musée national de préhistoire (mnp, eyzies-de-tayac) for their support and to all their collaborators and colleagues for their help and involvement in the lunel-viel research program “people and environments in the middle pleistocene” (pi j.-ph.b., pgm p2 –drac-sra occitanie). mp received funding through an a*midex grant (no. anr-11-idex0001-02) from the french government program ‘investissements d’avenir’. finally, thanks to r. sardella and the editors/reviewers of amq for their invitation to present the preliminary results from the lunel-viel i cave. references alférez f., inigo c. (1990) los restos de dicerorhinus hemitoechus (perissodactyla; mammalia) del pleisto 84 brugal j.p. et al. . ceno medio de pinilla del valle (madrid). actas de paleontologia, 22-45. antoine p.o. (2002) phylogénie et évolution des elasmotheriina (mammalia, rhinocerotidae). mém. du muséum national d’histoire naturelle, paris, pp. 359. arribas a., garrido g. (2008) hiénidos (pachycrocuta brevirostris (aymard, 1864) y hyaena brunnea thunberg, 1820) del yacimiento de fonelas p-1 (cuenca de guadix, granada). in arribas a. (ed.) vertebrados del plioceno superior terminal en el suroeste de europa: fonelas p-1 y el proyecto fonelas. inst. geol. y min. de españa, cuad. mus. geomin., 10, 201-230. bonifay e. (1968) stratigraphie et industries lithiques de la grotte n°1 du mas des caves à lunel-viel (hérault). in la préhistoire, problèmes et tendances, cnrs éd., 37-46. bonifay e. (1976a) les grottes du mas des caves (lunel -viel, hérault). livret-guide de l’excursion c2 (provence et languedoc méditerranéen), ix° congrès uispp, 197-204. bonifay e. (1976b) outils sur os et os utilisés dans le paléolithique ancien du mas des caves à lunel-viel (hérault). note préliminaire. premier colloque international sur l’industrie de l’os dans la préhistoire. ed. université de provence, 157-167. bonifay e. (1981) les plus anciens habitats sous grotte découverts à lunel-viel (hérault). archéologia, 150, fig. 11 biplot diagram comparing the mean number of scratches and pits in the cervid teeth from lunel-viel. the error bars correspond to the standard deviation (±1 sd). the ellipses correspond to the gaussian confidence ellipses (p= .95) of the centroids for current grazers and grazers published by solounias & semprebon (2002). 30-42. bonifay e. (1989) paléolithique inférieur et moyen : premiers témoignages humains. in archéologie de la france, 30 ans de découvertes. minist. de la culture. ed. réunion des musées nationaux, paris, 32-34. bonifay e., bonifay m.f. (1965) age du gisement de mammifères fossiles de lunel-viel (hérault). c.r.acad.sc., 260, 3441-4. bonifay e., combier j. (1984) le quaternaire: peuplements humains. in synthèse géologique du sud-est de la france, vol. i: stratigraphie et paléogéographie. mém. brgm, 125, 553-556. bonifay m.f. (1967) principales formes caractéristiques du quaternaire moyen du sud-est de la france (grands mammifères). bull. mus. anthr. préh. monaco, 14, 49-62. bonifay m.f. (1971) carnivores quaternaires du sud-est de la france. mém. m.n.h.n., série c, xxi, 49-337. bonifay m.f. (1973) dicerorhinus etruscus falc. du pleistocène moyen des grottes de lunel-viel (hérault). annales de paléontologie, 59, 79-112. bonifay m.f. (1980) le cheval du pléistocène moyen des grottes de lunel-viel (hérault): equus mosbachensis palustris n.ssp. gallia-préhistoire, 23, 233281. bonifay m.f. (1986) le matériel osseux déterminable au paléolithique ancien: mise en évidence, catégories, histogrammes. artefacts, 3, «outillage peu élaboré en os et en bois de cervidés», 11-14. bonifay m.f. (1991) equus hydruntinus reg. minor n.ssp. from the caves of lunel-viel (hérault). in meadow r.h., uermann h.p. (eds), equids in the ancient world ii, wiesbaden (de): reichert, reihe a., naturwissenschaften, n. 19/2, 178-216. boudadi-maligne m. (2010) les canis pléistocènes du sud de la france: approche biosystématique, évolutive et biochronologique. doctorat univ. bordeaux 1. bowen f., carden r.f., daujat j., grouard s., miller h., perdikaris s., sykes n. (2016) dama dentition: a new tooth eruption and wear method for assessing the age of fallow deer (dama dama). international journal of osteoarchaeology, 26, 1089-1098. brown w.a., chapman n.g. (1991a) age assessment of fallow deer (dama dama): from a scoring scheme based on radiographs of developing permanent molariform teeth. journal of zoology, london, 224, 367379. brown w.a., chapman n.g. (1991b) the dentition of red deer (cervus elaphus): a scoring scheme to asses age from wear of the permanent molariform teeth. journal of zoology, london, 224, 519-536. brown w.a., chapman n.g. (1991c) age assessment of red deer (cervus elaphus): from a scoring scheme based on radiographs of developing permanent molariform teeth. journal of zoology, london, 225, 8797. brugal j.p. (1985) le bos primigenius boj., 1827 du pléistocène moyen des grottes de lunel-viel (hérault). bull. mus. anthrop. préhist. de monaco, 28, 7-62. brugal j.p., argant a., boudadi-maligne m., crégutbonnoure e., croitor, r., fernandez p., fourvel j.b., fosse p., guadelli j.l., labe b., magniez p., uzunidis a. (2020) pleistocene herbivores and carnivores from france: an updated overview of the literature, sites and taxonomy. annales de paléontologie, 106, 102384. brugal j.p., fosse p., guadelli j.l. (1997) comparative study of bones assemblages made by recent and plio-pleistocene hyaenids (hyaena, crocuta). proceed. of the 1993 bone modification conference (hot springs, south dakota), l.a.hannus, r.p.winham (dir.), archeology lab., augustana college, occ.publ., 1, 158-187. brugal j.p., boudadi-maligne m. (2011) small and/to large canids in south-western europe: taxonomic status and biochronological contribution. quaternary international, 243 (1), 171-182. brugal j.p., argant j., crispim j.a., figueiredo s., martin serra a., palmqvist p. (2012) the complex carnivore-rich assemblages from furninha (peniche, portugal): a multidisciplinary approach. journal of taphonomy, 10 (3-4), 417-438. callou c. (2003) de la garenne au clapier: étude archéozoologique du lapin en europe occidentale. mém. du muséum national d’histoire naturelle, pp. 189. cardoso j.l. (1996) les grands mammifères du pléistocène supérieur du portugal. essai de synthèse. geobios 29(2), 235-250. chapman n.g., chapman d. (1970) fallow deer: their history, distribution and biology. terence dalton: lavenham. crégut-bonnoure é. (1995) les lagomorphes. in defleur a., crégut-bonnoure é. (eds.), le gisement paléolithique moyen de la grotte des cèdres (le pland’aups, var), documents d’archéologie française. maison des sciences de l’homme (ed.), paris, 143147. croitor r., bonifay m.f., brugal j.p. (2008) systematic revision of the endemic deer haploidoceros n. gen. mediterraneus (bonifay, 1967) (mammalia, cervidae) from the middle pleistocene of southern france. paläontologische zeitschrift, 82(3), 325-346. croitor r., sanz m., daura j. (2018) the endemic deer haploidoceros mediterraneus (bonifay) (cervidae, mammalia) from the late pleistocene of cova del rinoceront (iberian peninsula): origin, ecomorphology, and paleobiology. historical biology, 32, 409427. cuvier g. (1822) recherches sur les ossemens fossiles où l’on rétablit les caractères de plusieurs animaux dont les révolutions du globe ont détruit les espèces. vol. 2. g. dufour et e. d’ocagne, paris, pp. 292. davis s.j.m. (2019) rabbits and bergmann’s rule: how cold was portugal during the last glaciation? biological journal of the linnean society, 128, 526-549. dawkins w.b. (1867) on the dentition of rhinoceros leptorhinus, owen. quarterly journal of the geological society, 23, 213-227. depéret c.j.j. (1923) sur la découverte d’un squelette de rhinocéros mercki kaup à palairac (aude). bull. de la société d’études scientifiques de l’aude, 108117. diez c. (1986) la fragmentation des os d’equidés et de preliminary data on the middle pleistocene site of lunel-viel i (hérault, france) 85 bovidés à lunel-viel (hérault). artefacts, 2, 23-42. donard e. (1982) recherches sur les léporinés quaternaires (pléistocène moyen et supérieur, holocène). unpublished phd thesis, university of bordeaux, talence. duvernoy g.l. (1854) nouvelles études sur les rhinocéros fossiles. archives du museum national d’histoire naturelle, 7, 1-144. eisenmann v., crégut-bonnoure e., moigne a.m. (1985) equus mosbachensis et les grands chevaux de la caune de l'arago et de lunel-viel. craniologie comparée. bull. mus.nat.hist.nat., paris, 7 (iv, 2), 157173. falconer h. (1860) on the ossiferous caves of the peninsula of gower, in glamorganshire, south wales: with an appendix, on a raised beach in mewslade bay, and the occurrence of the boulder-clay on cefn -y-bryn. quarterly journal of the geological society 16, 487-491. falconer h., murchison c. (1868) palaeontological memoirs and notes of h. falconer, with a biographical sketch of the author. spottiswoode and co, london, pp. 675. fortelius m., mazza p.p.a., sala b. (1993) stephanorhinus (mammalia: rhinocerotidae) of the western european pleistocene, with a revision of s. etruscus (falconer, 1868). palaeontographia italica, 80, 63115. fosse p. (1992) la hyène des cavernes comme agent d’accumulation des ossements à lunel-viel (hérault, france): observations préliminaires. artefacts, 9, «outillage peu élaboré en os et en bois de cervidés» iv, paris, 1991. treignes (belgique), cedrac, artefacts 9, 91-96. fosse p. (1994) taphonomie paléolithique: les grands mammifères de soleilhac (haute-loire) et de lunelviel 1 (hérault). unpublished phd univ. provence aix-marseille. fosse p. (1996) la grotte n° 1 de lunel-viel (hérault, france): repaire d'hyènes du pléistocène moyen. etude taphonomique du matériel osseux, paléo, 8, 47-80. fosse p., fourvel j.b., madelaine s. (2020) le lynx lynx pardinus spelaeus boule, 1910 du pléistocène moyen de la grotte de l'escale (bouches-du-rhône, france): données paléontologiques et taphonomiques. paléo, 30(2), 108-137. fosse p., brugal j.p., crégut-bonnoure e., fourvel j.b., madelaine s. (2021) the lynxes (lynx pardinus/ spelaeus, lynx lynx) from the middle pleistocene to the holocene in southern france: a paleontological and taphonomical overview. jornades d'arqueozoologia, valencia, museu de prehistòria. fourvel j.b. (2012) hyénidés modernes et fossiles d'europe et d'afrique: taphonomie comparée de leurs assemblages osseux. unpublished phd université toulouse le mirail toulouse ii, pp. 612. gervais p. (1867) zoologie et paléontologie générales: nouvelles recherches sur les animaux vertébrés vivants et fossiles. arthus bertrand, paris, pp. 478. gervais p., serres m. de (1846) sur les mammifères dont on a trouvé les restes fossiles dans la caverne 86 brugal j.p. et al. de lunel-viel et dans les sables de montpellier. in edwards m., brongniart a., decaisne j. (eds.), annales des sciences naturelles comprenant la zoologie, la botanique, l’anatomie et la physiologie comparée des deux règnes, et l’histoire des corps organisés fossiles. paris, v. masson (éd.) 3eme ser., 266-272. guérin c. (1973) les trois espèces de rhinocéros (mammalia, perissodactyla) du gisement pléistocène moyen des abîmes de la fage à nouailles (corrèze). nouvelles archives du muséum d‘histoire naturelle de lyon, 11, 55-84. guérin c. (1980) les rhinocéros (mammalia, perissodactyla) du miocène terminal au pleistocène supérieur en europe occidentale. comparaison avec les espèces actuelles. univ. claude-bernard, département des sciences de la terre, lyon. guérin c. (2010) coelodonta antiquitatis praecursor (rhinocerotidae) du pléistocène moyen final de l’aven de romain-la-roche (doubs, france). revue de paleobiologie, 29, 697-746. kahlke h.d. (1975) die rhinocerotiden-reste aus den travertinen von weimar-ehringsdorf. paläontologische abhandlungen 337-398. kahlke h.d. (1977) die rhinocerotidenreste aus den travertinen von taubach. quartärpaläontologie 2, 305-359. kuhn b.f. (2011) hyaenids: taphonomy and implications for the palaeoenvironment. cambridge scholars publishing, pp. 215. kurten b. (1956) the status and affinities of hyaena sinensis owen and hyaena ultima matsumoto. american museum novitates, 1764, 1-48. kurten b. (1968) pleistocene mammals of europe. aldin, chicago, pp. 320. lacombat f. (2003) étude des rhinocéros du pléistocène de l’europe méditerranéenne et du massif central paléontologie, phylogénie et biostratigraphie. phd museum national d’histoire naturelle, paris. lapparent de broin f., bour r., parham j.f., perälä j. (2006) eurotestudo, a new genus for the species testudo hermanni gmelin, 1789 (chelonii, testudinidae). c.r.palevol, 5, 803-811. lartet e. (1867) note sur deux têtes de carnassiers fossiles (ursus et felis), et sur quelques débris de rhinocéros, provenant des découvertes faites par m. bourguignat dans les cavernes du midi de la france. annales de sciences naturelles, 8, 157-194. le grand y. (1987) aménagement de l’habitat au paléolithique inférieur et moyen: exemple du midi méditerranéen. mém. d.e.a., univ.de provence aixmarseille 1. le grand y. (1994) approche méthodologique et technologique d'un site d'habitat du pléistocène moyen: la grotte n° 1 du mas des caves (lunel-viel, hérault). unpublished phd univ. provence, aix-marseille 1. jeannet m. (1976) lunel-viel. nouvelles archives du museum d'histoire naturelle de lyon, 14, suppl., 4546. lópez-martínez n. (1989) revisión sistemática y bioestratigráfica de los lagomorfos (mammalia) del terciario y cuaternario de españa. memorias del mu seo paleontológico de la universidad de zaragoza, pp. 3. magniez p. (2010) etude paléontologique des artiodactyles de la grotte tournal. etude taphonomique, archéozoologique et paléoécologique des grands mammifères dans leur cadre biostratigraphique et paléoenvironnemental. unpublished phd université de perpignan via domitia. mazza p. (1988) the tuscan early pleistocene rhinoceros dicerorhinus etruscus. palaeontographia italica, 75, 1-87. mecozzi b., sardella r., boscaini a., cherin m., costeur l., madurell-malapeira j., pavia m., profico a., iurino d.a. (2021) the tale of a short-tailed cat: new outstanding late pleistocene fossils of lynx pardinus from southern italy. quaternary science review, in press. mourer-chauvire c. (1975) faunes d’oiseaux du pléistocène de france: systématique, évolution et adaptations, interprétation paléoclimatique. géobios, 8(5), 332-352. noury f. (1997) analyse et distinction des cervidés du pléistocène moyen de la grotte i du mas des caves (lunel-viel, hérault, france). mém. d.e.a. université bordeaux 1. owen r. (1846) a history of british fossil mammals, and birds. john van voorst, pp. 626. pelletier m. (2018) évolution morphométrique et biogéographie des léporidés dans les environnements méditerranéens au pléistocène. implications socioéconomiques pour les sociétés humaines. unpublished phd thesis, aix-marseille university, aix-enprovence. pelletier m. (2019) morphological diversity of wild rabbit populations: implications for archaeology and palaeontology. biological journal of the linnean society, 128, 211-224. riglet p.h. (1977) contribution à l’étude de l’âge du cerf élaphe (cervus elaphus l.). unpublished thesis ecole nationale vétérinaire de maison-alfort, pp.75. rivals f., sanz m., daura j. (2016) first reconstruction of the dietary traits of the mediterranean deer (haploidoceros mediterraneus) from the cova del rinoceront (ne iberian peninsula). palaeogeography, palaeoclimatology, palaeoecology, 449, 101 -107. sharples c.m., fa j.e., bell d.j. (1996) geographical variation in size in the european rabbit oryctolagus cuniculus (lagomorpha: leporidae) in western europe and north africa. zoological journal of the linnean society, 117, 141-158. semprebon g., godfrey l.r., solounias n., sutherland m.r., jungers w.l. (2004) can low-magnification stereomicroscopy reveal diet? journal of human evolution, 115-144. serres m. de, dubreuil j.m., jeanjean a. (1828) recherches sur les ossements fossiles des cavernes de lunel-vieil (hérault). mém. du muséum d’hist. nat., xvii, 380-463. serres m. de, dubreuil j.m., jeanjean a. (1839) recherches sur les ossements humatiles des cavernes de lunel-viel. montpellier: boehm et cie (éds), pp. 256. solounias n., semprebon g. (2002) advances in the reconstruction of ungulate ecomorphology with application to early fossil equids. american museum novitates, 3366, pp. 49. stiner m.c. (1990) the use of mortality patterns in archaeological studies of hominid predatory adaptations, journal of anthropological archaeology, 9(4), 305-351. stiner m.c. (2012) competition theory and the case for pleistocene hominin-carnivore co-evolution, journal of taphonomy, 10(3), 129-145. turner a. (1990) the evolution of the guild of large terrestrial carnivores during the plio pleistocene. geobios, 23, 349-368. turner a., anton m., werdelin l. (2008) taxonomy and evolutionary patterns in the fossil hyaenidae of europe. geobios, 41, 677-687. uzunidis-boutillier a. (2017) grands herbivores de la fin du pléistocène moyen au début du pléistocène supérieur dans le sud de la france. implications anthropologiques pour la lignée néandertalienne. unpublished phd thesis, aix-marseille université. uzunidis-boutillier a. (2020) dental wear analyses of middle pleistocene site of lunel-viel (hérault, france): did equus and bos live in a wetland? quaternary international, 557, 39-46. viret j. (1961) catalogue critique de la faune des mammifères miocènes de la grive-saint-alban. 2e partie (suite du fascicule iii, 1951). publications du musée des confluences, 6, 53-81. werdelin l., solounias n. (1991) the hyaenidae: taxonomy, systematics and evolution. fossils and strata, 30, 1-104. wiesel i. (2006) predatory and foraging behaviour of brown hyenas (parahyaena brunnea (thunberg, 1820)) and cape fur seal (arctocephalus pusillus pusillus schreber, 1776) colonies. p 219. bio-centre grindel and zoological museum university of hamburg, germany, hamburg. preliminary data on the middle pleistocene site of lunel-viel i (hérault, france) 87 ms. received: january 20, 2021 revised: february 2, 2021 accepted: may 7, 2021 avaiable online: june 10, 2021 88 amq abs mannella et al palcom 141-145.pub available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 137 141 fucino palaeo-lake: towards the palaeoenvironmental history of the last 430 ka giorgio mannella 1, biagio giaccio 2, giovanni zanchetta 1, eleonora regattieri 1, niklas leicher 3, stephanie scheidt 3, thomas grelle 4, carlos lehne 4, christian rolf 4, thomas wonik 4, sebastien nomade 5, alison pereira 5,6, elizabeth niespolo 7,8, paul renne 7,8, melanie leng 9,10, jonathan dean 9,10, camille thomas 11, daniel ariztegui 11, mario gaeta 12, fabio florindo 13, gian paolo cavinato 2, antonello provenzale 14, bernd wagner 3 1 dipartimento di scienze della terra, university of pisa, pisa, italy 2 institute of environmental geology and applied geoengeneering (igag cnr), roma, italy 3 institute of geology and mineralogy, university of cologne, cologne, germany 4 leibniz-institute for applied geophysics, rock physics & borehole geophysics, hannover, germany 5 laboratoire des sciences du climat et de l’environnement (cea-cnrs-uvsq), gif-sur-yvette, france 6 ecole française de rome, roma, italy 7 department of earth and planetary science, university of california, berkeley, usa 8 berkeley geochronology center, berkeley, usa 9 centre for environmental geochemistry, school of geography, university of nottingham, nottingham, uk 10 nerc isotope geosciences facilities, british geological survey, keyworth, nottingham, uk 11 section département des sciences de la terre et de l'environnement, université de genève, genève, switzerland 12 dipartimento di scienze della terra, university of roma “sapienza”, roma, italy 13 istituto nazionale di geofisica e vulcanologia, roma, italy 14 institute of geosciences and georesources (igg cnr), pisa, italy corresponding author: g. mannella <giorgio.mannella@dst.unipi.it> abstract: the sedimentary succession deposited in fucino palaeo-lake potentially records the environmental history of the central mediterranean region continuously since the early pleistocene and up to recent historical times. fucino palaeo-lake sediments are interbedded with numerous volcanic ash layers which allow the reconstruction a robust and independent chronological framework of past environment changes. this framework is a fundamental tool to synchronise different archives at a regional and extra-regional scale and to better understand the spatio-temporal climate variability in the quaternary at the orbital and millennial-scales. here we present new preliminary data for the last five glacial to interglacial cycles. keywords: fucino palaeo-lake, drilling, core catcher, quaternary, volcanic ash 1. introduction in june 2015 drilling operations in fucino basin resulted in the recovery of a 82 m long pilot core (cores f1-f3 in fig. 1) documenting the interval from early marine isotope stage (mis) 6 to late holocene. investigations on cores f1-f3 (giaccio et al., 2015a; 2017) documented the potential for this natural archive to produce a regionally representative and independently dated record of climatic variability. from a chronological point of view, the site is particularly relevant because of its proximity to quaternary peri-tyrrhenian volcanic centres. (fig. 2). these volcanic centres had an intense explosive activity which resulted in the deposition of a number of tephra in the basin. these tephra layers can be used today as important chronological and stratigraphic marker beds (e.g. giaccio et al., 2012, 2015b; regattieri et al., 2017). this is a crucial requirement for comparing intraand inter-regional palaeoclimatic records based on different dating methods. in particular, the rich tephrostratigraphic content poses the basis for a better understanding of the temporal relationship between them and with respect to the main climatic forcing (e.g. orbital). furthermore it allows to evaluate differences in magnitude and expression of quaternary palaeoclimatic change across regions. with the purpose to extend back in time the record, a new drilling campaign (cores f4-f5) was set in fucino basin in june 2017. the preliminary analyses so far performed on the lacustrine marls and the chronological assistance provided by the tephro-stratigraphic framework, indicate that the recovered succession continuously spans the last five glacial to interglacial cycles, i.e. from mis 12/mis 11 up to the holocene. 2. geological setting the fucino basin, located in the central apennine chain, abruzzo (fig. 1a), is the largest intermountain basin in the central apennines. this basin is an active tectonic basin and its evolution was controlled by two antithetic fault systems (ne-sw and nw-se; galadini & galli, 2000). the opening of the basin, possibly concurrent with the onset of lacustrine sedimentation, commenced in the early pleistocene in response to an extensional phase along the apennine chain (e.g. d’agostino et al., 2001). unlike other basins in this region, fucino lake has continuously existed since the early pleistocene and till 1875 ad, when the lake was artificially drained. https://doi.org/10.26382/aiqua.2018.aiquaconference 142 fig.1 r eference m ap of the fucino b asin (a) location of fucino b asin w ith respect to the m ain eruptive centers active during the last 1.8 m a. (b) s haded relief of the fucino p lain show ing the location of the g eolazio (g l), telespazio (ts ), s trada p rovinciale 20 (s p ), fucino 1 and 3 (g iaccio et al., 2015; 2017) and 4 and 5 (this study) boreholes. d ashed blue lines are the isochrones (in m s) of the p lio-q uaternary infilling w ith respect to the q uaternary m aster faults (bold red lines= responsible for the asym m etrical (half-graben) basin geom etry. d otted green lines are the traces of the available seism ic lines. (c) s eism ic line 3 (see trace in panel b) show ing the internal architecture of the p lio-q uaternary continental deposits of the fucino b asin along a w -e oriented profile. the projected location of the g l, s p , f1-f3 and f4-f5 boreholes is also show n. a , b , c : m ain unconform ities; s eq. 2 m essinian foredeep sedim ents; s eq. 3: p liocene fluvial and alluvial deposites; s eq. 4: q uaternary lacustrine and fluvial deposits. figure m odified after g iaccio et al. (2015a). mannella g. et al. 143 3. material and methods 3.1 drilling operations the drilling site (fig 1 b, c) was selected by evaluating the sedimentation rate obtained from the combined interpretation of tephro-chronological information collected from pre-existing cores (see fig. 1 caption) and the general sedimentary-tectonic architecture of the basin (fig. 1 b, c). compared to the previous drilling site (f1-f3), the f4-f5 site provided us the opportunity of recovering a less expanded sedimentary succession. at the selected site (42.00 °n, 13.54 °e), two parallel holes down to ca. 86 m below ground level (b.g.l.). cores were recovered with identical 1.5 m long coring devices operating with an offset of 75 cm to ensure overlap between the f4 and f5 series. core catchers were subsampled directly in the field, whereas cores were carefully packed and stored for further analyses. the f4 hole was logged immediately after drilling and down to a depth of 80 m b.g.l. the logging equipment consisted of a multi-sensor (gamma ray, resistivity and magnetic susceptibility) probe operating in accord to the internal protocols of the leibniz institute for applied geophysics (liag). 3.2. preliminary core analysis core opening and core description was carried out at the university of cologne, germany. macroscopic tephra layers were directly sampled for further analyses in specialised laboratories, while for suspect cryptotephra smearslides were taken for optical-microscope analysis. cores underwent non-destructive analysis, (i.e. x-ray fluorescence scanning and magnetic susceptibility). further analyses were conducted at the palaeomagnetic laboratory in grubenhagen (einbeck, germany) of the liag. here the stable components of natural remanent magnetization (nrm) where characterised. after preliminary studies, a raw core composite was elaborated by taking into account drilling depths and clear stratigraphic markers, such as tephra layers, to match the f4 and f5 cores. this preliminary composite profile served the purposes of core sub-sampling for further analyses. subsampling was carried at a variable resolution (from 1 cm every 2nd cm to every 8th cm) and resulted in a set of more 2000 samples which are currently being processed. 3.3 geochemical analyses on core catcher material total carbon (tc), total inorganic carbon (tic), total nitrogen (tn), total sulfur (ts), and stable oxygen isotope compositions were measured on discrete samples from the top of each core catcher. samples were dried in an oven at 50 °c. after disaggregation and sieving, the fraction below 100 μm was powdered and homogenised for geochemical analyses. tn and ts were determined with a vario micro cube combustion cns elemental analyser (elementar, germany) after combustion at 1150 °c, whilst tc and tic were measured with a dimatoc 200 (dimatec, germany) at the university of cologne, germany. toc was calculated by subtracting tic from tc. 3.4. preliminary tephra analyses major and minor oxide element compositions were determined on micro-pumice fragments and/or glass shards, from some selected tephra from cores f4-f5. the analyses were carried out at the igag-cnr in rome, italy, using a cameca sx50 electron microprobe equipped with a five-wavelength dispersive spectrometer analytical. 4. results and discussion the analyses run in the core samples so far allowed us to recognise more than 130 macroscopic tephra layers. preliminary tephrostratigraphic surveys evidenced the presence of 16 tephra in common with the f1-f3 drilling site in the first 35 m. this confirmed that the uppermost 35 m in f4-f5 replicate the f1-f3 record (i.e. the last ca. 190 ka). preliminary analyses on some of the major tephra layers from the lower part of the recovered succession (i.e. below 35 m) allowed us to identify the correlatives of other important regional tephrostratigraphic markers. among these, the most relevant are listed in the table below: the vico α tephra, together with a sharp and clear change in the lithological properties of the sediment, constrains the lowermost part of our succession to the mis 11-12 boundary. results from biogeochemical analyses on the core catcher material show that the different proxies are involved in a significant variability, with major trends consistent between the different proxies (fig. 2). changes in tic are assumed to be mainly related to authigenic (i.e. biomediated) precipitation of calcite, according to the results from f1-f4 core (giaccio et al., 2015). this process could be favoured by enhanced lake primary productivity as well as by increased ca input from the catchment (e.g. gierlowsky-kordesh, 2010; vogel et al., 2010). as for toc, similarly to tic, its variation is generally controlled by the rate of organic matter production in the lake and in catchment vegetation (leng et al., 2013) and by the preservation of om. therefore higher values of both tic and toc could be linked to warmer and wetter periods (i.e. interglacials/interstadials), where ions and nutrient are flushed from the well-developed soils into the lake. the toc/tn ratio is usually related to the source of om (aquatic/terrestrial), with higher (lower) values indicating prevailing terrestrial (lacustrine) input (meyers & ishiwatari, 1995). the general variability expressed by the proxy series depicts changes of the palaeoenvironmental context, which can be interpreted in the frame of the climate fucino palaeo-lake: towards the last 430 ka variability of the last 5 glacial-interglacial cycles. this is demonstrated by the good correlation potential of the tic and toc curves from fucino lake with the lr04 benthic stack (fig. 2). during the mis 10, 8, 6 and 4-2 glacial intervals, reduced lake productivity and contraction of terrestrial vegetation with respect to the lacustrine one determined, respectively, lower tic and toc as well as lower toc/tn ratio. interestingly, despite the relatively low time resolution obtained from the core catcher material, our record shows some of the main features of the middle-late pleistocene climate variability. this is characterised by relatively abrupt glacial terminations and the progressive enhancement of the 100ka power (e.g. tzedakis et al., 2017). 5. conclusions ongoing and future investigations, including detailed petrographic and geochemical analyses and radiometric dating of tephra layers, together with highresolution biogeochemical, stable isotope and palaeomagnetic analyses, will make it possible to fully explore the potential of the fucino lacustrine succession as a long climatic archive. we are currently preparing a composite profile anchored to the sedimentary succession by borehole logging data. this represents a fundamental step to establish a reliable age-depth model. the rich tephrostratigraphic documentation appears very promising thanks to several macroscopic tephra layers and numerous cryptotephra. most of these tephra originate from the nearby peri-tyrrhenian volcanic centres, which were characterised by a peculiar eruptive history. this makes fucino tephra layers particularly suitable for both indirect (geochemical fingerprinting) and direct (40ar/39ar) dating. this will make it possible to elaborate a robust and completely independent chronology for the observed variations in biogeochemical and magnetic parameters over the interval between termination v and the holocene. such a multi-proxy and high resolution approach will allow to address in detail climatically driven environmental changes at both orbital and millen 144 fig. 2 preliminary data from fucino f4-f5 drilling plotted against drilling depths compared to the lr04 benthic stack (lisiecki & raymo, 2005). yellow and blue shadings indicate odd and even numbered marine isotope stages, respectively. mannella g. et al. nial scales and to evaluate their duration and magnitude on a broad geographic scale. references d’agostino n., jackson j. a., dramis f., funiciello r. (2001) interactions between mantle upwelling, drainage evolution and active normal faulting: an example from the central apennines (italy). geophysical journal international, 147, 475-497. galadini f., galli p. (2000) active tectonics in the central apennines (italy) input data for seismic hazard assessment. natural hazards, 22, 225–270. giaccio b., nomade s., wulf s., isaia r., sottili g., cavuoto g., galli p., messina p., sposato a., sulpizio r., zanchetta g. (2012) the late mis 5 mediterranean tephra markers: a reappraisal from peninsular italy terrestrial records. quaternary science reviews, 56, 31-45. giaccio b., regattieri e., zanchetta g., wagner b., galli p., mannella g., niespolo e., peronace e., renne p., nomade s., cavinato g.p., messina p., sposato a., boschi c., florindo f., marra f., sadori l. (2015a) a key continental archive for the last 2 ma of climatic history in central mediterranean area: a preliminary report on the fucino deep -drilling project, central italy. scientific drilling, 3, 17. giaccio b., regattieri e., zanchetta g., nomade s., renne p.r., sprain c.j., drysdale r.n., tzedakis p.c., messina p., scardia g., sposato a., bassinot f. (2015b) duration and dynamics of the best orbital analogue to the present interglacial. geology, 43, 603-606. giaccio b., niespolo e., pereira a., nomade s., renne p.r., albert p.g., arienzo i., regattieri e., wagner b., zanchetta g., gaeta m., galli p., mannella g., peronace e., sottili g., florindo f., leicher n., marra f., tomlinson e.l., (2017) first integrated tephrochronological record for the last ~190 kyr from the fucino quaternary lacustrine succession, central italy. quaternary science reviews, 158, 211-234. gierlowsky-kordesch e. h. (2010) lacustrine carbonates, in: developments in sedimentology, 61, 2-50. leng m.j., wagner b., boehm a., panagiotopoulos k., vane c.h., snelling a., haidon c., woodley e., voegel h., zanchetta g., baneschi i. (2013) understanding past climatic and hydrological variability in the mediterranean from lake prespa sediment isotope and geochemical record over the last glacial cycle. quaternary science reviews, 66, 123-136. lisiecki l.e., raymo m. e. (2005) a pliocenepleistocene stack of 57 globally distributed benthic δ18o records. paleoceanography, 20, pa1003. meyers p.a., ishiwatari r. (1995) organic matter accumulation records in lake sediments, in: physics and chemistry of lakes. (ed.) lerman a., imboden d., gat j., springer, berlin, 279-328. regattieri e., giaccio b., nomade s., francke a., vogel h., drysdale r.n., perchiazzi n., wagner b., gemelli m., boschi c., mazzini i., galli p., peronace e. (2017) a last interglacial record of environmental changes from the sulmona basin (central italy). palaeogeography, palaeoclimatology, palaeoecology, 472, 51-66. tzedakis p.c., crucifix m., mitsui t., wolff e.w. (2017) a simple rule to determine which insolation cycles lead to interglacials. nature, 542(7642), 427-432. vogel h., wagner b., zanchetta g., sulpizio r., rosén p. (2010) a paleoclimate record with tephrochronological age control for the last glacial-interglacial cycle from lake ohrid, albania and macedonia. journal of paleolimnology, 44, 295-310. 145 ms. received: may 7, 2018 final text received: may 23, 2018 fucino palaeo-lake: towards the last 430 ka 146 amq 27 sn 2 mazza pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 27 (1), 2014, xi xvii paleontology spring field school report on the excavation of castel cellesi (bagnoregio, viterbo, central italy) paul mazza department of earth sciences, university of florence, florence, italy corresponding author: p. mazza <paul.mazza@unifi.it> abstract: fossil remains of palaeoloxodon antiquus were found in 2013 at "campo della spina", near the small village of castel cellesi (bagnoregio, viterbo, central italy). a paleontology spring field school was planned, under the patronage of aiqua and the italian paleontological society, to raise funds for the excavation. sixteen students attended the lectures delivered by eight eminent teachers, most of which members of aiqua. the excavation unearthed many bones of the highly disarticulated skeleton of palaeoloxodon. following an agreement reached with the regional board of the ministry of cultural heritage and environmental conservation of southern etruria the specimens were left in situ. they will be housed in an eco-structure that will be built over them and that will represent a cutting-edge museum with no such equivalent in italy. keywords: palaeoloxodon antiquus, paleontological excavation, spring field school, middle pleistocene, central italy. preamble in july 2013, the discovery of fossil remains of a large-size, senile palaeoloxodon antiquus at "campo della spina", a few kilometers southwest of the hamlet of castel cellesi (bagnoregio, viterbo, central italy, fig. 1), was reported to the department of earth sciences of the university of florence (fig. 2). an exploratory excavation was conducted at the end of august. on that occasion, a grid layout of 1 m2 georeferenced squares, oriented nw-se, was established over the area to be excavated. the squares were identified with letters and numbers, starting from a1, at nw, to d7 at se. three squares were explored, namely, a4, b5 and c6, where bones were exposed. a growing concentration of bones a left humerus and numerous ribs was found from a4 to c6 (fig. 3). part of the specimens were immersed, whereas others lied over, a greyish silty sedimentary body containing small volcanic breccias. a systematic excavation was therefore planned late in spring 2014. to raise the funds for the excavation a paleontology spring field school was also planned at castel cellesi. sixteen students and eight teachers from many italian colleges participated in the field school (fig. 4). by the first half of june, geoelectrical and georadar investigations were conducted to explore the resistivity of the fossil-bearing deposits, as well as to locate possible concentrations of bones. these surveys intended to reduce the excavation activities to a minimum, and save time and money. the geoelectrical exploration showed a lens of less resistive sediments dipping northwards. in contrast, the georadar survey gave chaotic and unreliable results. the excavation (figure 5) excavations began on the 16th of june, 2014. the operations started from the squares b6, a5, c7 and d6 that were adjacent a4, b5 and c6 that had been explored in spring. this was decided following the bones that lied exposed from the walls of the three previously dug squares. the excavation was conducted using a methodology of "exfoliation" of the layers. stratigraphy (figure 6) within the excavated area, under the topmost 5-8 cm of trampled sediment, lie 50-60 cms of massive, ochercoloured silty-clay (us2), consisting of reworked tuffaceous material with lithoclasts of different composition, but mostly of pumice, and with plant remains of various size, rhizoliths, small, white, thin-shelled gastropods. bioturbations are also visible. this layer lies over a similar one (us3), some 90 cm thick, separated by a very hard lateritic duricrust, which forms an irregular horizon fig. 1 location map of the castel cellesi excavation. sandwiched in between the two layers. the duricrust coats 16 to 90 cm-wide channels. us3 contains a large sedimentary lens, 30 to 50 cms thick, made of a gravel of poorly-rounded and poorly-sorted lithic elements floating in a greyish silty matrix (us4). the upper surface of the lens is irregular. it often intrudes upwards in us3 forming diapir-like pillars or flame-like structures. the lens is the fossil-bearing sedimentary body of the succession. the bones lie within and upon the grey gravelly-silty lens. all the layers are directed n-s and dip mazza p. xii fig. 2 lower molars of palaeoloxodon antiquus. the specimens were the first evidence of the presence of the fossiliferous site. xiii paleontology spring field school, castel cellesi excavation fig. 3 result of the exploratory excavation at the site. fig. 4 some of the participants of the castel cellesi’s paleontology spring field school during the excavations. 10° n. the fossil-bearing lens dips markedly towards square d3. more in general, the stratigraphic succession, consists of the following units, from the bottom upwards: 1) about 20 cm of rhythmic grey clay laminae, each approximately 1 cm thick, interbedded with fine-grained sands made of quartz and volcanic minerals (us7: the base of this unit is not exposed: fig. 6 a, b); 2) 5 cm of light-yellow to whitish clayey marl with intercalations of lenticular grey clay and fine-grained sand made of quartz and volcanic minerals. this level contains plant remains rhizoliths and ripple-marks (us6: fig. 6 a, b); 3) 30 cm of fine-grained sand and laminated clay, at times lenticular, with frequent plant remains (us 5: fig. 6 a, b); 4) about 60 cm of light-grey, massive clayey silt, containing reworked tuffaceous material, various kinds of lithoclasts, numerous plant remains of different size, rhizoliths, small, thin-shelled, whitish gastropods and bioturbations (us3: fig. 6 c-f); 5) lateritic duricrust (fig. 6 c, d); 6) about 150 cm of solid, ocher-colored clayey silt, similar to the underlying ones of us3 (us2: fig. 6 c -d, f, g-h). in the upper part, at the transition to the overlying us1, the unit is markedly reddened by soil processes (fig. 6 f-h); 7) about 60 cm of whitish lacustrine diatomitic deposits. this level contains numerous plant remains, rhizoliths and shells of small freshwater mollusks. at the base there are several channels, some 100-120 cm wide (us1: fig. 6 f-h). the succession likely belongs in the tuffs of the "paleo-vulsini" complex. it is therefore tentatively dated to around 600 ka. nonetheless, this age attribution is still provisional and needs to be verified. the specimens given the limited time granted for the excavation and after an agreement reached with the regional board of the ministry of cultural heritage and environmental conservation of southern etruria to leave the specimens in situ and not to recover them, the excavations were extended to the following squares: a3, b3, b4, b6, b7, c3, c4, c5, c7, d3, d4, d5, d6 and d7. the bones sum up to a total of 130. they belong almost entirely to paleoloxodon antiquus, except a small fragmental rib likely of a cervid (cervus elaphus?), found at the boundary between squares c5 and c6. the skeletal elements are all disarticulated, with the only exception of three thorachic vertebrae. the bones were nonetheless found accumulated in a relatively small area. many bones seem having a bimodal orientation nw-se and ne-sw, but this needs careful taphonomic verification (fig. 5). hypothetical reconstruction of the site's formation the fossiliferous lens (us4), consisting of poorly rounded and poorly sorted gravel elements floating within a silty matrix has the characteristics of a fairly fluid debris-flow. these highly concentrated slurries of sediment and water are triggered by high relief, abundant xiv fig. 5 plan view of the excavation. mazza p. xv paleontology spring field school, castel cellesi excavation fig. 6 a-b. basal part of the castel cellesi stratigraphic succession. c-e. details of the stratigraphic units met at the excavation. loose sediment trapped in steep catchments and a sharp peak in surface hydrological activity, during prolonged rain. the flame-like structures that deform the upper surface of the fossil-bearing sedimentary body, as well as the roughly bimodal arrangement of the bones, indicate that the debris-flow was probably quite fluid. based on the degree of wear of its teeth and on its particularly large size, the castel cellesi elephant was an old male. the characters of the stratigraphic succession indicate sedimentation in a shallow water basin, likely a swamp or a small lake. the sedimentary succession suggests that the water body alternatively deepened evolving into a lake or shallowed drying up and being replaced by a network of channels interspersed with vegetated plains. the elephant probably died along the banks of the water body, where us7-5 had already deposited, possibly bogged in the muddy sediments. nonetheless, this cannot be verified until the animal’s extremities are found. alternatively, the elephant might have died from dehydration during a drought event. the degree of disarticulation of the skeleton, as well as the lack of evidence of weathering and carnivore ravaging on the bone surfaces indicate that the carcass probably decayed submerged in the water body. once decomposition had reached an advanced phase, the debris flow (us4) ran into, entrained and buried, the already disar xvi mazza p. fig. 7 draft of the project for the structure that shall house the castel cellesi paleontological site. ticulated elephant carcass, scattering the bones. the water body still maintained for a while and its normal pattern of sedimentation was restored (us3). then it dried up, at least locally, and the area was subjected to soil formation and carved by a set of small channels. alternating wet and dry conditions favored the formation of the lateritic duricrust. the area subsequently drowned again and the swamp/lacustrine sedimentation was again resumed (us2). after that it emerged once more, new soil was formed and then it definitively drowned evolving in a lake. during this final phase the area was enriched with silica of volcanic origin, which favored the blooming of diatom colonies (us1). future prospects the fate of the castel cellesi elephant is unique in italy. contrary to usual practice, the fossil skeleton will not be retrieved from its natural grave. the regional board of the ministry of cultural heritage and environmental conservation of southern etruria made the decision to leave it where nature preserved it. the skeleton, together with the stratigraphic succession next to it, will be housed in an eco-structure, built in glass and wood, which will also include a mounted copy of a skeleton of palaeoloxodon antiquus, a classroom for lessons in situ and a laboratory (fig. 7). the building will be powered by photovoltaic panels and will use rainwater, which will be recicled using plant water purifiers. if the project will be realized in full respect the plan, the structure has no such equivalent in italy. being located in almost incontaminated surroundings, it would be a natural science laboratory for students from the schools of every order and degree, as well as for researchers of the widest range of natural history fields. it can even be used by archeologists, because the site is very close to etruscan and roman finds. the project is indeed ambitious. but ambitions are made to achieve. acknowledgements i wish to thank deeply aiqua and its president prof. adele bertini for the patronage of castel cellesi’s paleontology spring field school. i extend my gratitude to profs. maria rita palombo, anna gandin, mauro coltorti, giorgio manzi, and pierluigi pieruccini and to phd dr. andrea savorelli who contributed to the success of the school. i am particularly indebted to the 16 students who participated in this enterprise: without their help and financial support the excavation and the castel cellesi’s paleontology spring field school would have been a mere daydream. i am also most grateful to the italian paleontological society (spi) for the patronage and helpful support. many thanks also to dr. maria letizia arancio, of the regional board of the ministry of cultural heritage and environmental conservation of southern etruria, for her most helpful assistance and advice. xvii paleontology spring field school, castel cellesi excavation ms. received: october 30, 2014 final text received: november 14, 2014 amq abs fontana et al tepro 209-212.pub available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 209 212 lidar-derived dems for geoarchaeological investigations in alluvial and coastal plains alessandro fontana, livio ronchi, sandro rossato, paolo mozzi dipartimento di geoscienze, università degli studi di padova, padova, italy corresponding author: a. fontana <alessandro.fontana@unipd.it> abstract: here we present some digital elevation models (dems) produced from airborne laser altimetry in the distal sector of the venetian-friulian plain. the research considered some areas where the high detail of the surface landforms allows to evidence the occurrence of some ancient anthropogenic features that normally are not detectable in the present landscape or have been eroded by recent human activity. case studies are selected from ne italy, but this work shows the potential of the use of lidar data for geoarchaeological and geological mapping in alluvial environments. keywords: holocene, geomorphology, geological mapping, ne italy 1. introduction the introduction of lidar technology (light detection and ranging) significantly changed the resolution and the scale of topographic surveys, with the possibility to analyse the landscape in a detailed tridimensional perspective and over large areas. in the lowland environments laser altimetry has became a fundamental tool for territorial planning and assessment of natural hazards (e.g. antonioli et al., 2017). the use of lidar data for geoarchaeological reconstructions is especially efficient in hilly environments because the possibility of filtering the vegetation cover (e.g. bernardini et al., 2018), but the use in alluvial plain and urban context is still largely unexploited, even if results are very promising (ninfo et al., 2011; 2016; mozzi et al., 2018). with this work we want to highlight the capability of laser altimetry to detect traces, which are almost completely invisible in the field or with the use of other technics for remote sensing. 2. material and methods the areas indicated as a) and b) in fig. 1 belongs to the alluvial plain of friuli venezia giulia region, where the lidar-derived dems are characterised by 1 m2 cell size and a vertical accuracy of ±0.15 m. the data were produced in 2006-2007 by the protezione civile of regione autonoma friuli venezia giulia, but dems can be freely download only since 2015 (www.irdat.fvg.it). the zones c) and d) are part of the veneto region and the laser altimetry was obtained by the lidar survey acquired by the italian ministry of the environment in the framework of the extraordinary plan of environmental remote sensing (pst-a) and its extension (pst-a extension 2008), with 1 m2 cell size and vertical accuracy of ±0.10 m. in both of the regions the tile covered by a single file has an extent of 2x2 km and, thus, several tiles were mosaicked together for covering the areas to investigate. the elaboration of dems was carried out through software arcmap and was rather simple: it consisted in the production of several dems with different elevation palette and color stretching, aiming at highlighting archaeological traces and morphological features. the topographic derivatives of dem, as hillshading, slope and aspect, were used to evidence topographic variations and anomalies, as boundaries among landforms and depositional units. 3. results here we present some areas where high-detail dem may improve the interpretation of the past landscape and, in particular, to support the detection of traces of past human activity. in the area west of aquileia, fig. 2a clearly evidences the existence of a fluvial ridge that, according to its direction, was built by the torre river and was directly draining into the grado lagoon. near ca’ baredi, a major settlement was built on top of the fluvial ridge during the mid-late bronze age (fontana et al., 2017). the new dem allows to highlight that the innermost part of the site was bounded to the south by the relict channel of the ancient ridge and, probably, an artificial canal was dug on the northern side of the village for isolating it. the trace of the depression related to the abandoned channel is well visible in the middle of the ridge and could be followed almost to the lagoon. these traces of the ancient landscape documented in ca’ baredi may be useful in interpreting other sites of the bronze age which have been discovered along the north -western adriatic coast but where relict surface morphology has been strongly reworked by modern anthropohttps://doi.org/10.26382/aiqua.2018.aiquaconference genic activities. the area depicted in fig. 2b is part of the bosco baredi of muzzana del turgnano, which is the largest semi-natural wood existing in the alluvial plain of northern italy and it is an important site for wildlife preservation. the wood has not been ploughed since late antiquity and this conservative setting allowed the extraordinary preservation of relict landforms. in particular, the dem highlights the convex topography of the natural levees (#1 in fig. 2) of the fluvial ridge dated to the final part of the lgm (20.4 ka bp, hippe et al., 2018), which are 1.5 m higher than the related floodplain and palaeochannel. throughout the alluvial plain, several other lgm ridges are present, but they have been severely levelled in the last centuries for agricultural practice (fontana, 2006). the main features recognised through the detailed elaboration of the dem is the complex and dense pattern of pathways used by people for moving through the wood. the main directions correspond exactly to the top of the lgm natural levees. this setting could be considered a fossil landscape as, according to archaeological investigations, before the roman period the main “roads” connecting the lagoon fringe with the mainland used this higher portion of the lgm ridges to avoid swamps and marshes. the original landform is so evident that the main trackway is traditionally called "sentiero arzarin" (i.e. pathway of the little dyke), even if it is a natural feature. in the area south of concordia sagittaria (fig. 2c), several pre-roman sites have been discovered in the last 20 years and the new lidar-derived dem highlights that almost all of them were settled along the scarps limiting an incised landform. this depressed morphology corresponds to a fluvial incision created by the tagliamento river between lateglacial and early holocene and that was after occupied by lagoon environment since about 7 ka bp (fontana, 2006). the scarps originally had a height of almost 10 m, but have been progressively lowered by the infill of lagoon and fluvial deposits and currently they are almost invisible in the landscape. the lidar clearly shows the continuity of the scarps and allows to plan detailed field survey to look for traces of ancient settlements. at the ne corner of the venice lagoon, where the ancient city of altinum was present, remote sensing of visible and near-infrared images and geophysical investigations evidenced the exceptional preservation of most part of the urban and productive structures dated at the roman period, which were mainly built between the 1st century bc and the 2nd century ad (ninfo et al., 2009; mozzi et al., 2016). the previous investigations highlighted also the traces related to the roman harbour and some canals artificially dug in to the lgm deposits. our dem analysis evidences the topographic signature of these structures, in particular the depression coinciding with the most inner portion of the harbour (i.e. the “darsena”). this was a basin with a “l” shape, consisting of two segments. these had both a length of 170 m and a width of 25 m and 44 m, respectively. the topographic signature of the ancient harbour structures is rather surprising because the area was reclaimed at the beginning of the 20th century and has been prone to several levelling interventions in the last decades. 4. discussion and conclusion the examples shown in fig. 2 show that in the areas where archaeological traces are present or probable, the analyses of topography through lidar data could be a powerful tool for detecting some faint evidence of past human activity. moreover, the use of very high detailed dems strongly supports the recognition of the morphological factors, which constrained the ancient settlement strategies. even if large parts of the alluvial and coastal plains of italy are already covered by lidar 210 fig. 1 simplified scheme of the alluvial and coastal plain of ne italy (modified after fontana et al., 2017) with indication of the studied sites discussed in the text: a) ca’ baredi near aquileia; b) bosco baredi near muzzana of turgnano; c) area south of concordia sagittaria; d) ancient city of altinum, near the airport of venice. fontana a. et al. 211 fig. 2 digital elevation models (dems) of the studied sites. a) ca’ baredi near aquileia; b) bosco baredi of muzzana; c) area south of concordia sagittaria; d) area of the roman harbour of altinum. lidar dems for geoarchaeology in alluvial and coastal plains surveys, unfortunately access to these data is sometimes still not free or difficult to obtain. notwithstanding, it is likely that in the near future, lidar surveys will be easily available and the increasing computational capability will make their processing and analysis fast and more detailed. references antonioli f., anzidei m., amorosi a., lo presti v., mastronuzzi g., deiana g., de falco g., fontana a., fontolan g., lisco s., marsico a., moretti m., orrù p.e., sannino g.m., serpelloni e., vecchio a. (2017) sea-level rise and potential drowning of the italian coastal plains: flooding risk scenarios for 2100. quaternary science reviews, 158, 2943. bernardini f., sgambati a., montagnari m., zaccaria c., micheli r., fragiacomo a., tiussi c., dreossi d., tuniz c., de min a. (2013) airborne lidar application to karstic areas: the example of trieste province (north-eastern italy) from prehistoric sites to roman forts. journal of archaeological sciences, 40, 2152-2160. fontana a., vinci g., tasca g., mozzi p., vacchi m., bivi g., salvador s., rossato s., antonioli f., asioli a., bresolin m., di mario f., hajdas i. (2017) lagoon settlements and relative sea level during bronze age in northern adriatic: geoarchaeological evidence and paleogeographic constraints. quaternary international, 439, 17-36. fontana a. (2006) evoluzione geomorfologica della bassa pianura friulana. monografie museo friulano storia naturale, udine, pp. 288. hippe k., fontana a., hajdas i., ivy-ochs s. (2018) a high-resolution 14c chronology tracks pulses of aggradation of glaciofluvial sediment on the cormor megafan between 45 and 20 ka bp. radiocarbon, 1-22. doi: org/10.1017/rdc.2018.21. mozzi p., fontana a., ferrarese f., ninfo a., campana s., francese r. (2016) the roman city of altinum, venice lagoon, from remote sensing and geophysical prospection. archaeological prospection, 23, 27-44. mozzi p., ferrarese f., zangrando d., gamba v., sainati c., fontana a., ninfo a., piovan s., rossato s., veronese f. (2018) the modeling of archaeological and geomorphic surfaces in a multistratified urban site in padua, italy. geoarchaeology, 33(1), 67-84. ninfo a., fontana a., mozzi p., ferrarese f. (2009) the map of altinum, ancestor of venice. science, 325, 577. ninfo a, ferrarese f, mozzi p, fontana a. (2011) high resolution dems for the analysis of fluvial and ancient anthropogenic landforms in the alluvial plain of padua (italy). geografia fisica e dinamica quaternaria, 94, 95-104. ninfo, a., mozzi, p., abbà, t. (2016) integration of lidar and cropmarks remote sensing for the study of fluvial and anthropogenic landforms in the brenta-bacchiglione alluvial plain (ne italy). geomorphology, 260, 64-78. 212 fontana a. et al. ms. received: may 14, 2018 final text received: may 24, 2018 base archeologia e ambiente: dominio delle acque e dominio sulle acque in antiche citta’ del territorio padano jacopo ortalli dipartimento di scienze storiche, via paradiso 12, ferrara, otj@unife.it riassunto: ortalli j., archeologia e ambiente: dominio delle acque e dominio sulle acque in antiche città del territorio padano. (it issn 0394-3356) tra gli elementi che nell’antichità caratterizzarono lo sviluppo dell’insediamento umano nei suoi rapporti con l’ambiente naturale le acque rivestirono un’importanza decisamente fondamentale; come utile esempio di riferimento per un quadro più generale, la documentazione archeologica dell’emilia romagna consente di mettere a fuoco quella che fu l’evoluzione di tale legame tra il ii millennio a.c. e la tarda antichità. se i primi significativi interventi di sfruttamento delle acque di superficie si riconoscono nei villaggi fortificati dell’età del bronzo, solo con l’affermazione della civiltà etrusca, tra il ix e il v secolo a.c., si osserva una razionale e articolata gestione delle componenti idrauliche tanto nelle città quanto nel loro retroterra agricolo. dopo il regresso tecnico e culturale che accompagnò la dominazione celtica della regione, a partire dal iii – ii secolo a.c. la conquista e la colonizzazione romana, con la fondazione di nuove città e la centuriazione dell’agro, portarono alla creazione di una efficiente rete infrastrutturale che consentì di regolamentare le acque urbane, governare i corsi fluviali, bonificare vasti settori della pianura e creare importanti idrovie. grazie alla solidità dell’organizzazione politica e amministrativa e alle capacità tecnologiche dei romani, tra il popolamento umano e l’habitat si istituì allora un rapporto di grande equilibrio, che entrò in crisi solo nella tarda antichità, con la decadenza dell’impero, finché nell’alto medioevo gli elementi naturali, e con essi le acque, per molti aspetti ripresero il sopravvento sull’uomo. abstract: ortalli j., archeologia e ambiente: dominio delle acque e dominio sulle acque in antiche città del territorio padano. (it issn 0394-3356) since antiquity the management of waters was extremely important for the planning and development of human settlements in accordance with the local environmental conditions. archaeological data from emilia romanga, italy, well illustrate the changes that occurred in cycles between the late antiquity and the ii millennia ac. the first recorded significant manipulation/use of surficial waters has been recorded in fortified village of the bronze age. it is however from the ix to v centuries bc that the etruscans established well planned, extensive hydraulic works within their cities and in the surrounding territories. that was followed by a dark period during the celtic occupation of the regions, during which the various hydraulic works, such as irrigation canals were not maintained and much became obsolete. the subsequent conquest and colonization by romans led to the revival of older settlements, funding of new towns, major aqueducts, and, among others, training of streams, construction of irrigation systems, draining of marshlands, d development of harbours. roman sought a most beneficial natural resources taming but trying to avoid irreparable deterioration of the environment. a sort of equilibrium between human settlements and the landscape was established that lasted for several centuries until the late stages of the roman imperial period when maintenance of the water works decreased. a new major decadence followed during early medieval times with the disinterest in properly maintaining the anthropic environment. parole chiave: emilia romagna, archeologia, urbanistica, infrastrutture, acque, etruschi, romani. keywords: emilia romagna, archaeology, urbanization, water works, etruscan, romans. il quaternario italian journal of quaternary sciences 23(2bis), 2010 volume speciale 335-354 1. introduzione da alcuni decenni l‘archeologia classica in italia ha finalmente aperto i suoi interessi a prospettive di ricerca attente alla piena contestualizzazione della documentazione, anche in relazione al paesaggio naturale, alle componenti geomorfologiche e stratigrafiche e ai vari processi deposizionali che condizionarono gli stanziamenti urbani di età storica. in questo quadro, che coinvolge tanto gli aspetti ambientali quanto lo sviluppo culturale, un’importanza fondamentale va indubbiamente attribuita al rapporto tra l’uomo e le acque, rapporto assai mutevole nei tempi e nei modi con cui si manifestò e caratterizzato da una forte asimmetria: mentre l’influenza delle acque sull’uomo era infatti regolata da fattori predeterminati e da fenomeni tendenzialmente ripetitivi, l’influenza dell’uomo sulle acque dipendeva da evenienze contingenti e da scelte comportamentali di per sé estremamente diversificate, per molti versi imprevedibili e non codificabili. per affrontare correttamente la questione è allora necessario muoversi in termini storicistici, partendo dai dati disponibili ed analizzandoli in una prospettiva diacronica che permetta di ricostruire le forme e le dinamiche di condizionamento, dipendenza oppure controllo che si svilupparono tra i diversi coefficienti naturali ed antropici. tenendo conto di tali presupposti qui ci proponiamo di valutare alcune testimonianze che offrono interessanti spunti di riflessione; per non essere troppo generici e per utilizzare riferimenti puntuali la trattazione sarà incentrata su un arco cronologico circoscritto, esteso sui due millenni che corrono dalla matura età protostorica al primo altomedioevo, e su un settore ben definito dell’ ital ia settentrionale, vale a dire la cispadana, sia perché nell’antichità l’area presentava una gamma di ecosistemi e di assetti demografici assai rappresentativi come campionatura di valore generale, sia per la conoscenza diretta che chi scrive vi ha maturato attraverso le indagini condotte su numerosi contesti archeologici. 336 j. ortalli 2. l’assetto geomorfologico e lo sviluppo storico della regione 2.1. i caratteri ambientali la cispadana (figg. 1-2) corrispondeva approssimativamente all’attuale emilia romagna, regione delimitata dal crinale degli appennini a sud, dal mare adriatico a est e dal corso del fiume po a nord (chevallier, 1988). per quanto riguarda gli ambiti preferenziali di interferenza con il popolamento umano occorre ricordare in special modo la fascia collinare, il versante costiero e soprattutto il vasto comprensorio di pianura, composto da terreni potenzialmente molto fertili, originariamente caratterizzati da una folta copertura vegetazionale e da corsi fluviali a prevalente regime torrentizio; a partire dal loro sbocco al piede appenninico questi furono frequentemente oggetto di esondazioni, divagazioni e mutamenti di corso, tanto da provocare ripetute e significative modificazioni degli assetti idrografici locali. sebbene aree umide e propriamente palustri fossero tendenzialmente circoscritte ad alcuni ambiti paralitoranei, numerosi settori territoriali interni, soprattutto tra media e bassa pianura, erano caratterizzati da suoli depressi o malamente drenati, risultando soggetti al ristagno di acque di superficie o alla periodica sommersione provocata dalla tracimazioni di fiumi e torrenti (aa.vv., 1980; chevallier, 1988; cremaschi, 1997). un’ulteriore differenza del paesaggio geografico nella protostoria e nell’antichità classica rispetto all’attuale è rappresentata dalle variazioni subite del litorale adriatico, dal momento che nel corso dei secoli in più punti la linea di costa è avanzata sensibilmente soprattutto per l’apporto di sedimenti fluviali, in primo luogo del po (fabbri, 1990; cremonini, 1994; cremonini, 1995; balista et al., 2007; cremonini, 2007). ad esempio l’abitato di spina, tra ferrara e comacchio, in età etrusca era situato entro l’apparato di foce deltizia del po a poco più di 3 km dal mare, mentre oggi ne dista una decina; per l’età romana si richiama invece il centro urbano di ravenna, un tempo affacciato sul litorale e ora a circa 7 km nell’entroterra, e la città portuale di rimini, che è a più di 1 km dal battente marino. 2.2. l’evoluzione dell’insediamento antico l’archeologia dimostra che l’ambiente della cispadana risultava comunque assai favorevole allo stanziamento umano (mansuelli, 1962; berselli, 1975; chevallier, 1983; malnati & manfredi, 1991; marini calvani, 2000; ortalli, 2009). dopo una consistente presenza antropica durante la preistoria, per l’età del bronzo medio e recente, nei secoli centrali del ii millennio a.c., si segnala in particolare lo sviluppo della cultura definita delle terramare, dal nome tradizionalmente attribuito al tipo di villaggio cintato, le cui genti dedite all’agricoltura si stanziarono soprattutto nel settore mediopadano che comprendeva l’emilia centrale. se nel tardo ii millennio per cause ignote si verificò una crisi del sistema insediativo regionale, con un sensibile decremento demografico e la scomparsa della maggior parte degli stanziamenti precedenti, nella prima età del ferro, dal ix secolo a.c., si registra l’affermazione della civiltà etrusca padana (fig. 1) (malnati & manfredi, 1991; cremaschi, 1997). sotto molti aspetti essa si distingueva da quella dell’etruria propria, centroitalica, anche per i condizionamenti e le opportunità derivate dal locale ambiente planiziale che ispirava differenti forme insediative ed un migliore sfruttamento del suolo. durante la fase iniziale del villanoviano i, nei più favorevoli comprensori agricoli si assiste allora alla creazione e alla rapida crescita sociale ed economica di fig. 1 carta della cispadana in età etrusca. (rielaborato da malnati & manfredi, 1991). map of cispadana during the etruscan age (modified after malnati & manfredi, 1991). numerosi villaggi. fin dall’viii secolo a.c. felsina, odierna bologna, assunse la fisionomia del capoluogo, mentre nel resto della regione una vera cultura urbana si affermò tra la fine del vi e il v secolo a.c.: periodo di apogeo dell’etruria padana in cui il forte sviluppo della comunità si accompagnò alla costituzione della città di marzabotto, nell’alta valle del reno, della già ricordata spina, alla foce del po, e di diversi altri abitati. nei primi decenni del iv secolo i vecchi domini etruschi furono invasi da celti transalpini, tra cui numerose tribù di galli boi: genti bellicose, di cultura più arretrata, che si stanziarono in gran parte della cispadana ad eccezione di alcuni settori dell’appennino e della costa adriatica abitati dai liguri e dagli umbri. il quadro geopolitico della regione mutò nuovamente tra il iii e il ii secolo a.c., quando roma la conquistò sottomettendo le popolazioni celtiche e italiche che vi risiedevano e colonizzandola. i romani crearono allora un nuovo sistema insediativo (fig. 2), accuratamente pianificato e basato sulla costituzione di nuove città e di grandi infrastrutture territoriali, destinato a perdurare, tra alterne vicende, fino ai tempi della caduta dell’impero nel 476 d.c.. 3. l’intervento umano sull’ambiente e sulle acque. 3.1. età del bronzo per quanto riguarda le forme di insediamento, durante la preistoria il popolamento locale dovette essenzialmente adattarsi all’habitat che lo circondava, in una condizione di subordinazione alla quale corrispondeva con strategie di selezione degli ambiti più favorevoli e di sfruttamento delle potenzialità di sosten337archeologia e ambiente: dominio delle acque e dominio ... tamento alimentare: circostanze che non di rado implicarono localizzazioni abitative di prossimità a corsi d’acqua. diversa, invece, fu la situazione che cominciò a delinearsi nell’età del bronzo, quando, ad una significativa scala territoriale, si ebbero i primi interventi di governo idraulico a fini insediativi, in concomitanza con lo sviluppo della civiltà delle terramare. come testimoniano vari scavi condotti tra il parmense e il modenese, raffrontabili ad altri siti della bassa pianura in sinistra po, nei secoli centrali del ii millennio a.c. i villaggi costituiti in modo stabile ed estesi su superfici di svariati ettari erano perimetrati da terrapieni rinforzati da palizzate e circondati da ampi fossati anulari alimentati da corsi d’acqua in parte canalizzata e derivata artificialmente (bernabò brea & cremaschi, 1997; cremaschi, 1997; cardarelli, 2009) (fig.3); data la collocazione perifluviale, al fine di neutralizzare gli effetti delle frequenti esondazioni, per programmatica cautela le capanne erano generalmente edificate a struttura aerea, secondo il principio della palafitta con impalcato ligneo su terra. la documentazione archeologica indica pure la possibile riescavazione di paleoalvei per addurre acque e di fossi esterni di impianto agricolo disposti concentricamente rispetto agli abitati . oltre a presupporre l’avvenuta acquisizione di una certa abilità tecnico-cognitiva nello sfruttamento dei flussi idrici naturali, un tal genere di stanziamento implicava buone attitudini progettuali da parte della comunità, evidentemente contraddistinta da un assetto sociale abbastanza articolato e capace di elaborare scelte finalizzate ad un uso utilitaristico delle acque, uso che sarà da ritenere ispirato non solo alla difesa ma anche ad interessi economici, in relazione al controllo del territorio e ad attività commerciali extracircondariali che potevano trovare i fig. 2 carta della cispadana in età romana. (rielaborato da marini calvani, 2000). map of cispadana during the roman age (modified after marini calvani, 2000). 338 loro assi di scorrimento privilegiato nei percorsi fluviali. dopo l’abbandono dei villaggi terramaricoli ed il calo di attestazioni archeologiche riscontrato nel bronzo finale, per registrare l’affermazione di una nuova evoluta cultura insediativa e di ulteriori significative intraprese volte ad un razionale confronto con l’ambiente acquatico occorre attendere gli inizi del i millennio a.c., quando, nella prima età del ferro, si registrò una considerevole ripresa demografica e lo sviluppo di numerosi stanziamenti. 3.2. gli etruschi nel ix secolo a.c. il settore emiliano incentrato su felsina (fig. 1) accolse quel popolamento etrusco che per cinque secoli avrebbe detenuto il potere su gran parte della regione. iniziano allora a registrarsi alcuni interventi che non rivestono più un carattere localistico, circoscritto a singoli areali, esprimendosi piuttosto in un’ottica di più ampia e pianificata gestione del comprensorio tanto a livello urbanistico quanto nel riordinamento del sistema territoriale. i progressi che in tal senso si raggiunsero non dipesero solo dall’affinamento delle capacità tecniche e delle conoscenze tecnologiche ma anche da generali motivazioni di t ipo sociale ed economico: la ricerca di migliori qualità abitative, tradotte nella costituzione di complessi insediativi sempre più articolati che spesso attribuivano una precisa funzione al rapporto di prossimità e interdipendenza con le acque fluviali o marine e alle loro potenzialità difensive o idroviarie; la crescita esponenziale dei traffici commerciali ad ampio raggio, protesi anche verso mercati mediterranei; lo sviluppo di pratiche agrarie volte ad incrementare la redditività delle coltivazioni cerealicole e quindi vitivinicole attraverso un efficiente apprestamento del suolo. come presupposto di contesto, per comprendere questi fenomeni evolutivi si deve considerare l’importanza determinante che presso le più avanzate civiltà mediterranee assunsero la speculazione razionale e l’elaborazione di norme e modelli teorici nei quali potevano fondersi i più vari principi dottrinali: dalla politica alla filosofia e alla religione, dalla scienza alla matematica. tale avanzamento delle conoscenze, che iniziò a delinearsi nell’viii secolo a.c., fu progressivamente affinato dai greci, dagli etruschi e quindi dai romani, per cui sarà sufficiente ricordare le esperienze di ippodamo di mileto, dell'etrusca disciplina, della trattatistica scientifica ellenistica e alessandrina, di vitruvio e dei gromatici veteres (coppa, 1968; dilke, 1979; sereni, 1982; gros & torelli, 1988; ). per tutta l’età classica, dunque, questi saperi fornirono un basilare quadro di riferimento per innumerevoli applicazioni pratiche nei campi dell’urbanistica, dell’infrastrutturazione territoriale, dell’ingegneria, dell’idraulica e dell’agronomia. 3.2.1. felsina durante il periodo villanoviano ed orientalizzante, tra il ix e gli inizi del vi sec. a.c., nei comparti rurali del bolognese si registra la realizzazione di vari impianti di risanamento del suolo e di regolamentazione idrica mediante l’attivazione di reti di fossati più o meno regolari, comuni anche nelle aree di villaggio, destinati al drenaggio delle acque di superficie (forte & von eles, 1994; ortalli, 1995) (fig. 4); contemporaneamente si assiste alla costituzione di felsina come capoluogo strutturato in senso protourbano a seguito di una scelta insediativa che per l’epoca appare di considerevole portata politico-amministrativa. nella selezione del sito dello stanziamento felsineo, che attorno alla metà dell’viii sec. a.c. condusse all’unificazione di diversi villaggi circostanti con un atto di vera e propria fondazione, sicuramente furono deterfig. 3 pianta della terramara del montale (mo). (rielaborato da bernabò brea & cremaschi, 1997). vicino al sito (fuori pianta) lo scavo ha restituito tracce di un paleoalveo che doveva alimentare il fossato. plan of terramara del montale (mo) (modified after bernabò brea & cremaschi 1997). close to the site (out of the plan) the excavation showed remnants of an ancient riverbed that should feed the ditch. j. ortalli 339 minanti le valutazioni di ordine geomorfologico e ambientale: l’area prescelta, estesa su quasi 200 ettari, era infatti situata in zona pedecollinare, sul conoide del torrente aposa, dove il suolo risultava stabile, ben drenato e pienamente integrato al fertile agro di alta pianura (fig. 5). se per un verso la comunità villanoviana si adattò alle condizioni idrografiche che già sussistevano, serrando l’agglomerato abitativo tra i corsi del torrente aposa a est e del primitivo alveo del vallescura (?) a ovest, per altro verso integrò tale configurazione idraulica con alcune opere infrastrutturali di rilevante entità (ortalli, 2008a). nella costruzione dell’imponente fortificazione a terrapieno e palizzate con cui venne cintato l’abitato (fig. 6), il settore settentrionale, non difeso da corsi naturali, accolse dunque una triplice linea di profondi fossati, probabilmente alimentati da una derivazione del torrente ravone che fluiva circa mezzo chilometro a ponente (fig. 5). l’arco limitaneo di scorrimento idrico così predisposto servì tra l’altro come collettore di raccolta per alcuni canali di buona ampiezza, scavati attraverso l’abitato per garantire l’ottimale deflusso e lo scarico delle acque di superficie (ortalli & pini, 2002) (fig. 5): circostanza che dimostra come le opere idrauliche allora messe in atto non avessero solo finalità difensive ma anche di efficace gestione del suolo urbanizzato e, probabilmente, di sfruttamento dei flussi correnti per attività civili di tipo domestico e lavorativo. 3.2.2. la situazione all’apogeo dell’insediamento etrusco-padano dopo queste prime significative esperienze, le note capacità di ingegneria idraulica degli etruschi si manifestarono in termini ancor più sistematici a partire dal tardo vi e per tutto il v secolo a.c. (ortalli, 1995); ciò avvenne a seguito di pianificate scelte politiche, economiche ed insediative che si concretizzarono nella costituzione dei centri urbani e degli stanziamenti minori con i quali fu ridisegnato l’ intero assetto insediativo dell’etruria padana (malnati & manfredi, 1991; ortalli, 2002). in tale occasione ancora una volta il controllo, la gestione e lo sfruttamento delle acque rappresentarono dei fattori di primaria importanza nella progettazione dei nuovi organismi residenziali. data la scarsità della documentazione archeologica relativa al periodo, per la felsina di piena fase etrusca possiamo segnalare solo la diversione a monte del fig. 4 pianta del villaggio villanoviano di casteldebole (bo). (rielaborato da forte & von eles, 1994). sono evidenziati i resti di canalizzazioni etrusche (a tratteggio obliquo) e romane di prima (a puntinato) e di seconda fase (a tratto nero pieno). plan of the villanovian village of casteldebole (bo) (modified after orte & von eles, 1994). the image shows remnants of etruscan canalizations (oblique hatching) and roman canalizations, either first (dotted hatching) and second phase (thick hatching). archeologia e ambiente: dominio delle acque e dominio ... 340 fig. 5 pianta di fase villanoviana-orientalizzante di felsina. (da ortalli, 2008a). al centro, con retino chiaro, è l’area di abitato, all’esterno, con retino più scuro, sono le necropoli. 1: corso originario del rio di vallescura; 2-6: canali artificiali e paleoalvei regolarizzati; 5: fossati e tratto di cinta difensiva di piazza azzarita. map of felsina during the villanovian-orientalized phase (from ortalli, 2008a). the built-up areas are located in the center of the map (light hatching); the necropolis are represented by dark hatching around the built-up areas. 1: original course of vallescura creek; 2-6: artificial channels and normalized ancient riverbeds; 5: ditches and part of the defensive wall of azzarita square. fig. 6 pianta e sezione stratigrafica dello scavo (1995-96) di piazza azzarita, a bologna, sui resti del sistema difensivo villanoviano di felsina. (da ortalli 2008a). dal settore interno abitativo, a meridione, si susseguono i resti di un terrapieno, alcune serie di palizzate di cui quelle principali, settentrionali, destinate a reggere lo spalto ad impalcato con galleria, tre fossati difensivi. plan and stratigraphic section of excavation of azzarita square (1995-96) in bologna, on the remnants of felsina villanovian defensive system (from ortalli 2008a). to the south, remnants of a rampart, few series of fences, and three defensive ditches are present in the inner inhabited sector. the main fences, the northern ones, were built to support the planking glacis with the arcade. j. ortalli rio di vallescura (ortalli & pini, 2002) (fig. 5), probabilmente realizzata per conferire una nuova funzione territoriale a quello che era stato il vecchio confine dell’abitato villanoviano, e le fitte sequenze di fossetti e scoline poste in luce nel suburbio della città (ortalli, 2003) (fig. 7), da interpretare anche come impianti di irrigazione a chiuse per colture specializzate. il centro di marzabotto, invece, è ampiamente noto per il suo accurato ordinamento urbanistico a maglia ortogonale, di ispirazione ellenica, nel quale risalta il rigoroso apparato di perimetrazione delle insulae abitative formato da canalette per la raccolta e lo scolo delle acque reflue e meteoriche (bentz & reusser, 2008) (fig. 8). per quanto riguarda i centri minori, oltre a vari siti della pianura bolognese e modenese delimitati da fossati (malnati & sassatelli, 2008), si possono richiamare alcune testimonianze archeologiche di grande interesse. l’isolato posto a controllo del guado allo sbocco di valle del fiume reno, presso casalecchio (ortalli, 1997a; ortalli, 1997c; ortalli, 2002), era servito da ampie strade inghiaiate fiancheggiate da fossi laterali di scolo regolarmente manutenuti (fig. 9), e formato da un’ordinata schiera di case marginate dall’alveo di un torrente, regolarizzato ed arginato, e da un reticolo di canali e fossi destinati tanto all’approvvigionamento domestico e ad attività artigianali quanto all’adduzione e allo smaltimento idrico dei vicini terreni agricoli (figg. 10-11). nel coevo caposaldo itinerario recentemente scoperto in via andrea costa (ortalli, c. s.), nei sobborghi occidentali di felsina, il piccolo complesso insediativo era addirittura racchiuso da un circuito quadrato di fossati, pure impiegati a scopo civile e lavorativo, raccordato a scoline colturali e a canali che si immettevano in un grande collettore di bonifica (figg. 1213). l’esempio più rappresentativo di questa volontà di integrazione urbanistica e di convivenza funzionale dei centri abitati con le acque è comunque rappresentato da spina (fig. 14). l’emporio creato dagli etruschi sull’antico ramo deltizio del po spinete, nei pressi dell’odierna comacchio, era infatti localizzato in un ambiente umido, tra acquitrini, diramazioni fluviali, cordoni e dune litoranee, parzialmente rimodellato attraverso l’escavazione di canali, la realizzazione di argini e opere spondali in terra e legno, la creazione di numerosi punti di approdo, così che l’intera città risultava contornata e attraversata da acque (uggeri, 1997; balista et al., 341 fig. 7 bologna, scavi (1998-99) di piazza viii agosto: suolo con tracce di sistema agricolo-colturale di età etrusca costituito da scoline parallele. bologna, excavations in viii agosto square (1998-99): a soil with signs of etruscan farming system costituted by parallel sluices. fig. 8 marzabotto, città etrusca: isolato abitativo con canaletta perimetrale di scolo delle acque. marzabotto, etruscan village: inhabited block with perimetric water drain. archeologia e ambiente: dominio delle acque e dominio ... 342 fig. 9 area degli scavi (1989-2000) di casalecchio di reno (bo). (da ortalli 1995). evoluzione del sistema idrico: nella fase iii di età etrusca è riconoscibile la regolare rete di canali che affiancava l’abitato; nella fase iv di età romana si nota l’assenza del torrente riassorbito dalla sistemazione centuriale. excavation areas (1989-2000) of casalecchio di reno (bo) (from ortalli, 1995). water system evolution: the regular channel network near the built-up area is recognizable during the iii phase etruscan in age; the creek is absent during the iv phase roman in age because it was absorbed became part of the centurial arrangement. j. ortalli 2007), attraverso le quali potevano tra l’altro circolare le imbarcazioni che all’epoca battevano le più trafficate rotte commerciali mediterranee. 3.3. i celti la sistematica attenzione che ai tempi della dominazione etrusca era stata riservata all’equilibrio tra le acque e i centri abitati fu bruscamente interrotta nei primi decenni del iv secolo a.c. dalla conquista della regione attuata dai celti (malnati & manfredi, 1991). in proposito occorre notare che le tribù dei galli boi che si installarono sui vecchi possedimenti felsinei, rioccupando metodicamente le strutture preesistenti, erano portatrici di capacità tecniche poco raffinate, se non nel campo della metallurgia, e soprattutto di canoni insediativi differenti rispetto a quelli italici, tali da comportare forme di organizzazione comprensoriale assai meno articolate, sostanzialmente ancora di tradizione protostorica. i resti archeologici riferibili agli stanziamenti di queste genti transalpine evidenziano l’assoluta mancanza di una dottrina urbanistica o anche solo di una cultura e di stili di vita propriamente cittadini (ortalli, 2008c); esse, inoltre, erano prive di un’autorità centrale che non fosse militare, circostanza che impediva una efficace programmazione di tipo amministrativo e di governo territoriale; infine, la base di sostentamento economico non era più rappresentata dall’agricoltura, che destinavano prevalentemente all’autoconsumo, bensì dall’allevamento e da attività artigianali che non richiedevano particolari cure nella gestione dell’ambiente. questi presupposti implicarono dunque uno scarso interesse per il controllo e la manutenzione degli impianti precedentemente ideati dagli etruschi, impianti che furono spesso riutilizzati in maniera passiva e degradata, comprese quelle elaborate sistemazioni idrauliche presenti negli abitati e nell’agro di cui gli scavi archeologici hanno evidenziato la progressiva defunzionalizzazione fino al completo abbandono (ortalli, 2008c; ortalli, c. s.) (fig. 15). dal momento che le esigenze della comunità celtica potevano essere soddisfatte da un ambiente sostanzialmente rinaturalizzato, nell’arco di poco più di un secolo venne quasi del tutto obliterato l’organico sistema geoantropico che fino al v secolo aveva caratterizzato l’insediamento regionale. 343 fig. 10 casalecchio di reno. (da ortalli, 2002). abitazione etrusca fiancheggiata da un canale artificiale (evidenziato a retino). casalecchio di reno (from ortalli, 2002). etruscan house flanked by an artificial channel (cross hatching). fig. 11 casalecchio di reno: foto di un canale etrusco sezionato dallo scavo. sotto l’arativo moderno e uno strato agricolo di età romana si riconosce il cavo con depositi e riempimenti detritici. casalecchio di reno: picture of an etruscan channel sectioned by the excavation. the hollow filled with deposits and debris is recognizable beneath the modern arable plain and a farmed layer roman in age. archeologia e ambiente: dominio delle acque e dominio ... fig. 12 pianta di scavo (1999-2000) del l ’ insediamento etrusco felsineo di via a. costa e delle acque circostanti (evidenziate in retino). (da ortalli, c. s.). l’edificio abitativo e altre strutture lavorative sono situate all’interno di fossati artificiali che delimitano un’area quadrangolare; all’esterno si trovano un torrente, a ovest, e un canale artificiale, a nord. excavation plan (1999-2000) of the a. costa street etruscan-felsinean settlement and of the surrounding water (cross hatching) (from ortalli, c. s.). the inhabited building and other working structures are located within artificial ditches that bound a quadrangular area; on the outside, there are a creek to the west and an artificial channel to the north. 344 fig. 13 bologna, via a. costa: canale di perimetrazione dello stanziamento abitativo etrusco. i depositi inferiori, da scorrimento idrico, sono sovrastati dai riempimenti detritici che in età celtica portarono alla progressiva occlusione del cavo. bologna, a. costa street: etruscan settlement perimetric channel. the lower deposits, formed by water flow, are overlied by debris fills that led to progressive hollow occlusion during the celtic age. j. ortalli 345 fig. 14 localizzazione della città etrusca di spina, di altri siti archeologici minori, e del sistema deltizio-costiero con la serie di cordoni litoranei costituitisi nel progressivo avanzamento della linea di costa. (rielaborato da balista et al., 2007). location of the etruscan village of spina, other less important archaeological sites, and the deltaic-coastal system characterized by a series of beach ridges formed during the progressive coastline progradation (modified after balista et al., 2007). 3.4. l’età romana un deciso cambiamento della situazione, ancora una volta determinato dal mutamento del quadro storico, si verificò tra il iii e il ii secolo a.c., quando la conquista romana della cispadana portò all’istituzione di solide forme di governo politico e alla progressiva affermazione di sperimentati modelli culturali e gestionali, concretizzatisi attraverso il capillare processo di colonizzazione che rinnovò il panorama poleografico e territoriale locale. in sostanza, per direttiva e secondo indirizzi accuratamente preordinati dal senato di roma e dai funzionari locali, venne allora attuata una considerevole serie di interventi finalizzati alla stabilizzazione sociale dei cittadini, al miglioramento delle qualità di vita e allo sfruttamento delle risorse naturali del posto, con durevoli ricadute sull’intera regione, anche nel fig. 15 – casalecchio di reno: scavo di un fosso di scolo etrusco con depositi inferiori da scorrimento idrico, corrispondenti al periodo d’uso, e riempimenti detritici superiori riferibili alla fase di defunzionalizzazione di età celtica. casalecchio di reno: excavation of an etruscan drain ditch characterized by lower water flow deposits, corresponding to its working period, and by higher debris fills related to the deactivation phase celtic in age. archeologia e ambiente: dominio delle acque e dominio ... senso del controllo e della valorizzazione delle acque. 3.4.1. la centuriazione delle campagne emblematica, da questo punto di vista, fu la centuriazione di tutto l’agro di alta e media pianura attuata per predisporre i lotti di terreno coltivabile da assegnare ai coloni immigrati secondo quella che era la prassi dell’agrimensura romana (dilke, 1979; sereni, 1982; settis, 1983). si trattò di una colossale operazione di apprestamento fondiario condotta estensivamente ma in progressione, per blocchi raccordati tra di loro fino a configurare un unitario sistema infrastrutturale sviluppato su una lunghezza di 250 km da rimini a piacenza (chevallier, 1983; dall’aglio, 1989; bottazzi, 1991; guandalini, 2001) (fig. 16). i limiti confinari delle quadre centuriali di circa 700 m di lato, che si incrociavano ortogonalmente, oltre che con strade vennero fatti di norma coincidere con fossi (fig 17): si creò così una capillare struttura di drenaggio e deflusso che scolava secondo natura verso nord-est, integrata da grandi canali anche di scolmamento fluviale (dall’aglio, 1997), grazie alla quale furono bonificati diversi terreni acquitrinosi o comunque soggetti al periodico ristagno delle acque. tale sistemazione risultò indubbiamente efficace anche per il buon governo e la stabilizzazione idraulica dei circondari urbani; lo stretto nesso tra tale parcellazione rurale e i centri abitati era del resto evidenziato dai tracciati dei decumani e soprattutto dei cardini, spesso innestati od originati dalle principali strade delle varie città che si disponevano lungo la via emilia (tozzi, 1989) (fig. 18). talora, poi, gli assi cardinali non si materializzarono in semplici fossati; diversi sono i casi in cui su di essi vennero inalveati lunghi segmenti di fiumi e torrenti anche di considerevole portata, ad esempio nei circondari di modena (mutina), bologna (bononia) e claterna o in romagna (cremonini, 1990; cremonini, 1991a; cremonini, 1991b; calzolari et al., 2003); oppure imbrigliati piccoli corsi divaganti, così da diluirne il flusso fino ad obliterarli completamente come nel caso documentato presso casalecchio di reno (ortalli, 1997a; ortalli, 1997c) (fig. 9). altrove, invece, in coincidenza dei cardini furono tracciati grandi invasi artificiali, tra i quali forse il canale navigabile ricordato dalle fonti letterarie che nel tardo ii secolo a.c. emilio scauro avrebbe addotto da parma fino al po (strab., v, 1, 11). grazie a questo genere di operazioni, durante i secoli della romanità l’ambiente planiziale della cispadana dovette assumere una fisionomia ampiamente antropizzata anche nel senso dell’ordine conferito al paesaggio idrico. 3.4.2. le città e le acque come componente urbanistica come suggeriscono alcune recenti ricerche, un’analoga diligenza per la cura delle acque si ebbe nella pianificazione delle città, sia nel caso della fondazione di nuove colonie sia della ristrutturazione di centri preesistenti (guarnieri, 1987; ortalli, 1997b; ortalli, 2005). com’è noto la cultura romana era tradizionalmente incline all’elaborazione di schemi teorici da applicare con metodicità in contesti tra di loro assimilabili; assecondando tale attitudine pare accertato che i magistrati, gli architetti e gli agrimensori che delinearono il nuovo assetto poleografico della cispadana spesso attuassero un modello urbanistico che tendeva ad isti346 fig. 16 veduta di un tratto dell’agro centuriato nel territorio di bagnarola di budrio (bo). (foto di maurizio molinari). view of a sector of bagnarola di budrio (bo) centurial countryside (photograph by maurizio molinari). fig. 17 – sezionamento e scavo di una strada romana glareata corrispondente a un cardine della centuriazione bolognese. il piano rotabile inghiaiato dal profilo arcuato consentiva il deflusso delle acque meteoriche nei due fossi di scolo che fiancheggiavano la massicciata. section and excavation of a roman street corresponding to a hinge of the bolognese century. the arched-profiled carriage plain filled with gravel enabled water run-off towards two drain ditches that flanked the ballast. j. ortalli tuire un preciso legame tra il centro abitato e le acque fluviali che lo circondavano: grazie a tale correlazione topografica le stesse acque poterono dunque divenire un fattore determinante nella caratterizzazione della forma urbis e degli assetti spaziali e funzionali interni. gli esiti di questo tipo di procedura non furono peraltro univoci. solo in poche località, quali parma e rimini (ariminum), si registra l’affiancamento della città ad un fiume di consistente portata: scelta evidentemente sconsigliata dalla consapevolezza che i regimi torrentizi tipici della regione rappresentavano un fattore di instabilità e pericolo per gli stanziamenti. con una frequenza decisamente maggiore sembra invece ricorrere la soluzione che prevedeva una contiguità tra l’abitato ed alcuni alvei di media o piccola entità; spesso questi erano allora irreggimentati, deviati o integrati da derivazioni e canalizzazioni artificiali, così da creare un sistema di acque periurbane e secanti, tra di loro raccordate, che avvolgevano e attraversavano la città a scopi sia difensivi che di utilità civile, per prelievi, scarico, forza motrice e circolazione idroviaria. una situazione simile si riscontra ad esempio nel primo suburbio e nel centro di piacenza (placentia), reggio emilia (regium lepidi), modena, forlì (forum livi) e rimini (ortalli, 1997b; marini calvani, 2000; ortalli, 2005). tra i casi meglio studiati si segnala poi bologna (fig. 19), circondata su due lati dal rio di vallescura e dal torrente aposa, il quale dovette pure alimentare un ramo forzatamente addotto all’interno dell’abitato; sui lati restanti furono invece scavati dei fossati, così da completare il circuito acquatico che marginava la colonia repubblicana (ortalli, 1993) (fig. 20). probabilmente non dissimile fu l’assetto anticamente conferito a imola (forum corneli) (vai, 1994; ortalli, 2005) (fig. 18), dove un giro perimetrale di acque naturali e artificiali lambiva il municipio, raccordandosi ad un’ansa senescente del fiume santerno verosimilmente sfruttata come approdo fluviale. a proposito di queste soluzioni urbanistiche val la pena di rammentarne anche l’evoluzione che se ne ebbe per il mutare degli assetti civici attorno all’età augustea, quando al venir meno delle esigenze difensive corrispose una consistente crescita della popolazione e delle attività edilizie; per agevolare le espansioni urbane in certi casi i vecchi fossati furono allora colmati e sovrastati da nuove strade (ortalli, 1993). 3.4.3. ravenna se già questi esempi documentano la sistematicità con cui le acque interne vennero governate e utilizzate a favore degli organismi urbani, il caso più eclatante della regione è comunque rappresentato da ravenna (fabbri, 1990; manzelli, 2000) (fig. 21). la nascita della città lagunare e del suo scalo adriatico è anteriore all’arrivo dei romani; sicuramente, però, furono essi a razionalizzarne l’impianto facendone un centro completamente integrato alle acque. l’abitato era allora bagnato a levante dal mare e circondato da fiumi e da 347 fig. 18 – pianta di imola in età romana. (da ortalli, 2005). a retino è indicato il centro abitato; con retino più chiaro l’originario corso del santerno e, più scura, l’ansa che si insinuava al margine della città dove poteva situarsi un approdo fluviale. a linea continua e tratteggiata i tracciati stradali accertati o ipotizzati, tra cui due cardini centuriali; a linea puntinata la ricostruzione dei corsi d’acqua e dei canali artificiali di età romana. plan of imola during the roman age (from ortalli, 2005). the built-up area is crosshatched; the original course of santerno river is highlighted by a lighter cross hatching, whereas the bright beside the village edge, where a landingplace might be located, is highlighted by a darker cross hatching. assessed and assumed roadways, among which two centurial hinges, are represented by continuous and dashed lines respectively; watercourses and roman artificial channels are represented by dotted lines. archeologia e ambiente: dominio delle acque e dominio ... acquitrini, il sottosuolo era impregnato dalle abbondanti risalite di falda da subsidenza, il centro era attraversato dall’alveo del padenna e da svariati canali tra cui la fossa lamises e il flumisellum padennae, lambito dalla grande fossa augusta per la navigazione paralitoranea indirizzata al po e contornato dal bacino portuale interno realizzato nel primo entroterra, a ponente, tra aree umide: tutte opere artificiali o di regolamentazione idraulica alle quali, al momento dello stanziamento della flotta imperiale da parte di augusto, poco più a meridione si aggiunsero i porti militari apprestati a classe (mauro 2005). lo stretto legame che a ravenna sussisteva tra la componente antropica e quella idrica ebbe innumerevoli riflessi sulla vita civile, pubblica come privata; si rammentano i problemi che la falda superficiale provocava all’edilizia abitativa, contrastati mediante drenaggi e consolidamenti del suolo con banchi di anfore o palificazioni, la necessità di sopraelevare le vie suburbane per garantirne l’agibilità, la difficoltà di approvvigionarsi di acque potabili, che venivano captate da profondi pozzi o addotte con lunghi acquedotti (manzelli, 2000). la vitalità e l’importanza per secoli rivestita dalla metropoli ravennate, che fu anche capitale dell’impero d’occidente e del regno dei goti, ci appare dunque come la migliore testimonianza dell’equilibrio che il sapere tecnico ed operativo dei romani riuscì a raggiungere nel rapporto tra l’insediamento di terraferma e le acque. 3.4.4. acquedotti e fogne nella prassi urbanistica romana, quale poté espri348 fig. 19 – pianta di bologna in età romana. (da ortalli, 1993). sullo sfondo del centro storico è evidenziato il reticolo stradale della città antica, delimitata da corsi d’acqua naturali in parte regolarizzati (torrente aposa e rio di vallescura) e da fossati artificiali (a tratteggio i tratti ipotizzati). plan of bologna during the roman age (from ortalli, 1993). the old city road network is highlighted in the old town centre; the old city was bounded by natural watercourses not completely modified (aposa and vallescura creeks) and by artificial ditches (assumed tracts are represented by dashed lines). j. ortalli mersi al meglio nella colonizzazione della cispadana, si coglie dunque la tendenza al dominio sull’ambiente e sulle acque attraverso quelle forme di programmatico controllo, modificazione e sfruttamento di cui si sono citati diversi esempi, che evidentemente richiesero considerevoli capacità amministrative e ingegneristiche. le stesse qualità, del resto, emergono considerando tante altre infrastrutture idrauliche di interesse locale, realizzate fin dal primo stanziamento delle città e sviluppatesi con speciale intensità tra il principato augusteo e quello di traiano, quando il livello della civiltà urbana raggiunse il suo culmine. a tale riguardo ricordiamo come ogni centro abbia restituito tracce archeologiche di efficienti impianti fognari che collegavano scarichi, collettori e cloache in una rete di smaltimento capillare e ben accudita. oppure opere di captazione e distribuzione di acque potabili, del genere dei vari acquedotti che dopo una lunga percorrenza alimentavano fontane ed edifici pubblici o privati: i tracciati potevano essere in galleria profonda, come a bologna (aa.vv., 1985) (fig. 22), su strutture ad arcate, come nel ravennate (prati, 1988), o in condutture sotterranee fittili, lapidee o con speco in muratura, come a rimini, nel reggiano e nell’imolese (borlenghi, 2000; ravara montebelli, 2002). 3.5. la tarda antichità nella tarda età imperiale, a partire dalla metà del iii secolo d.c., il positivo ciclo di sviluppo politico e sociale dell’impero romano incominciò a risentire di una generale crisi che ebbe pesanti riflessi anche a livello insediativo regionale (ortalli, 1999; ortalli, 2008b). tra i fattori più problematici, al riguardo, si segnalano l’instabilità del governo centrale e più ancora l’indebolimento delle amministrazioni municipali e dell’autorità gestionale locale; le considerevoli difficoltà economiche accentuate dalla pressione fiscale, che limitavano persino i finanziamenti per le spese ordinarie; lo scadimento, se non il regresso, delle competenze tecniche e delle strutture produttive e operative; il declino della cultura civica e delle qualità di vita urbana; il calo demografico e l’abbandono di alcuni ambiti residenziali nelle città, cui si accompagnò il parziale spopolamento di vari settori agricoli. tale congiuntura incise negativamente anche sulla capacità di preservare un efficace e funzionale rapporto tra l’uomo e l’ambiente, tanto da generare una concatenata serie di fenomeni involutivi, degenerativi e infine disgregativi che nel tempo si risolsero nello scardinamento dell’organico assetto poleografico e insediativo creato dai romani, scardinamento al quale neppure teodorico, con la sua mirata azione di restaurazione urbanistica, fu in grado di porre rimedio. 3.5.1. la crisi delle città in proposito, per ciò che qui interessa, nei contesti abitativi di età tarda si segnala il tendenziale, progressivo dissesto degli apparati infrastrutturali. accanto 349 fig. 20 – bologna, piazza azzarita: sezione di un canale scavato sul lato settentrionale della città romana. nella porzione mediana della parete terrosa si notano i depositi scuri di riempimento del grande cavo artificiale a fondo piano. bologna, azzarita square: section of a channel excavated in the roman city northern side. dark deposits, which filled the big artificial plane-bottomed hollow, are evident on the earthy wall middle portion. archeologia e ambiente: dominio delle acque e dominio ... alla probabile riduzione di portata degli acquedotti, provocata dalla scadente cura prestata agli impianti di captazione e di distribuzione, sarà da rimarcare soprattutto il deterioramento degli ormai vetusti sistemi di smaltimento idrico: scarichi, fogne e collettori che le comunità non erano più capaci di mantenere adeguatamente, otturati, colmati, tagliati, fino ad una completa rovina (brogiolo & gelichi, 1998; ortalli, 1999) (fig. 23). i guasti che da tale incuria derivarono alle città furono considerevoli e permanenti, in quanto sui piani di calpestio iniziarono a depositarsi accumuli detritici la cui consistenza si accentuò sempre più: a generarli, del resto, non erano solo gli apporti meteorici, ma anche i residui dispersi dal disfacimento di molti edifici abbandonati, spesso realizzati con argilla e strutture lignee, dalla mancata rimozione dei rifiuti domestici e lavorativi, che il potere pubblico non riusciva a controllare, dalla costituzione di piccoli spazi coltivabili in molte aree urbane un tempo abitate ma ormai dismesse. l’esito di questo processo deposizionale, che arrivò a cancellare non solo metaforicamente le vecchie città romane, è rappresentato dagli spessi strati di cosiddette “terre nere” (brogiolo et al., 1988; brogiolo & gelichi, 1998): stratificazioni archeologiche di soffice terreno ricco di componenti organogene che nei centri della regione emiliana, come di tante altre, segnano la fase di transizione tra la tarda antichità e l’altomedioevo. 3.5.2. la crisi del territorio ad accrescere il degrado dei contesti urbani contribuirono infine altri fattori, pure legati alla sfera gestionale ma ad una scala più vasta. la mancanza di volontà o di capacità nella cura dell’ambiente coinvolse infatti anche i comprensori esterni, provocando gravi alterazioni dell’equilibrio territoriale e svariati fenomeni di dissesto idrogeologico, probabilmente accentuati dai concomitanti effetti di un ciclo climatico particolarmente negativo (veggiani, 1990). nell’agro centuriato la defunzionalizzazione di una 350 fig. 21 – pianta dell’area di ravenna e di classe in età romana. (rielaborato da manzelli, 2000). a retino le acque dell’adriatico (a est), dei bacini portuali interni e dei corsi d’acqua naturali e artificiali. a linea continua le infrastrutture abitative e stradali. plan of the ravenna and classe areas during the roman age (modified after manzelli, 2000). the adriatic sea (to the east), inner harbor docks, and natural and artificial watercourses are cross-hatched. inhabited and road structures are represented by continuous lines. parte dei sistemi scolanti poté dunque causare impaludamenti e divagazioni di piccoli alvei, restituendo all’acqua terreni che un tempo le erano stati sottratti (bottazzi, 1991; calzolari, 1991; ortalli, 1995; ortalli, 1997a; j. ortalli ortalli, 1997c) (fig. 9); ancor più devastante dovette essere il mancato controllo dei fiumi, che si tentò di regimare con improvvisate opere di imbrigliamento e difesa spondale del genere riconosciuto a villa s. maurizio, nel reggiano, e a bologna, con il cosiddetto “muro del reno” (veggiani, 1990; cremonini, 1991a; cremonini, 1991b; ortalli, 2008b). considerando questi presupposti si spiegano i poderosi alluvionamenti che tra la tarda antichità e il primo medioevo, con i loro depositi, sommersero per metri il centro di modena (cremaschi & gasperi, 1988); l’abbandono del municipio appenninico di veleia, progressivamente sepolto dagli smottamenti dovuti al collasso degli impianti di drenaggio dei pendii sovrastanti (catarsi dall’aglio & dall’aglio, 1991-92); l’occlusione dei bacini portuali di classe e ravenna, privati delle necessarie opere di dragaggio dei sedimenti rilasciati dalle vicine foci fluviali (fabbri, 1990; manzelli, 2000): tutti esempi indicativi del crollo del pianificato sistema di conduzione territoriale che per secoli aveva permesso ai romani di dominare gli elementi naturali. 4. discussione dopo le prime interessanti esperienze dei fossati anulari attorno ai villaggi dell’età del bronzo, come si è notato è a partire dall’età del ferro che nella convivenza tra le comunità umane della cispadana e l’habitat naturale divennero sempre più importanti le iniziative connesse al confronto con le acque interne; le interferenze tra la componente antropica e quella ambientale si risolsero allora in una variegata gamma di soluzioni che oscillavano dalla supremazia dell’uomo sulle acque a quella delle acque sull’uomo. in questo mutevole rapporto è evidente che l’influenza antropica sull’elemento naturale era strettamente correlata ad una serie di fattori che determinavano la qualità e la quantità delle forme di controllo attuate dalla comunità, fattori che potevano interagire secondo diverse modalità ed intensità, in senso positivo oppure negativo. tra di essi si potranno rammentare: l’esistenza e le capacità di un’autorità centrale interessata alla pianificazione degli stanziamenti urbani e comprensoriali; l’efficienza delle strutture tecniche ed amministrative locali incaricate delle attività di gestione e vigilanza; le esigenze del sistema economico e produttivo in relazione alle dotazioni infrastrutturali; la conoscenza di tecniche idonee alla realizzazione di opere finalizzate alla conduzione del suolo; la disponibilità di risorse finanziarie adeguate alla cura dei servizi pubblici; il livello ideologico e sociale della collettività e le sue aspettative circa la qualità di vita e la rappresentatività che dovevano connotare le città. le tante genti che nel corso dei secoli si sono alternate nella regione hanno evidenziato attitudini e comportamenti molto differenti rispetto a tutti questi fattori, sia a causa delle contingenze storiche delle varie epoche sia con riferimento alle conoscenze scientifiche e ai modelli e alle tradizioni culturali che erano proprie ad ogni comunità. così se già gli etruschi dimostrarono interesse ed abilità nella ricerca di un equilibrato rapporto con le acque, solo il solido ordinamento politico ed amministrativo dello stato romano fu in grado di operare in modo programmatico e generalizzato sulle città e sull’agro, riuscendo a costituire un sistema di ampia scala, stabile e funzionale. al contrario, il relativo disinteresse dei celti nei confronti degli organismi urbani e dei comparti agricoli e le loro scarse competenze nella conduzione delle infrastrutture di servizio provocarono un sensibile regresso rispetto alla precedente fase etrusca. al sostanziale collasso dell’assetto insediativo basato sulla funzionale convivenza tra stanziamento umano e ambiente, delle acque ma non solo, si giunse nella tarda antichità, quando la concomitanza di più circostanze negative restituì una posizione dominante ai fenomeni naturali creando quelle condizioni che, alle soglie del medioevo, sono state definite di ruralizzazione delle città. per concludere segnaliamo il fatto che la medesima situazione osservata in cispadana, con le sue iniziative di bonifica, regimazione e sfruttamento delle acque per usi difensivi e civili, abitualmente si riscontra anche altrove nel territorio italico, in particolare sotto quelle dominazioni, quale l’etrusca e la romana, che con le loro capacità tecniche e politico-amministrative a lungo gestirono territori assai ampi. pur nel riconoscimento di queste tendenze generali occorre tuttavia precisare che le modalità di attuazione della maggior parte degli 351 fig. 22 speco dell’acquedotto romano in galleria che correndo lungo la valle del reno raggiungeva bologna. tunnelled roman aqueduct that reached bologna along the reno river walley. archeologia e ambiente: dominio delle acque e dominio ... interventi idraulici di cui si è parlato erano strettamente collegate e condizionate dalla specifica natura geomorfologica dei diversi ambienti, ragion per cui i confronti più stretti con il quadro emiliano-romagnolo si colgono in contesti insediativi assimilabili, quali quelli che gravitavano sulla valle del po. 5. conclusioni tra i dati salienti della panoramica regionale che si è proposta emerge in primo luogo il fatto che il progresso delle antiche comunità umane si accompagnò ad una crescente consapevolezza della fondamentale importanza da attribuire al controllo e allo sfruttamento delle acque, ritenute essenziali per esigenze tanto strutturali, legate alla funzionalità abitativa e all’economia, quanto ideologiche, in relazione alle qualità di vita. a tale scopo nei secoli l’uomo ha affinato sempre più le proprie abilità tecniche e competenze tecnologiche in campo idraulico; si trattò tuttavia di un processo discontinuo, in quanto la sua efficacia fu direttamente proporzionata al livello di organizzazione politica e di capacità amministrativa raggiunto dalle varie civiltà: solo le società più evolute furono infatti in grado di intraprendere iniziative di gestione delle acque di grande complessità ed estensione, ad una scala di sistema territoriale. di queste realizzazioni sono rimaste numerose tracce archeologiche sul terreno, a partire dall’età del bronzo e soprattutto da quella del ferro, con gli etruschi, fino a raggiungere il culmine sotto il dominio di roma, quando nelle città e nelle campagne si istituì un rapporto ottimale, di sostanziale equilibrio tra l’uomo e le acque, che durò per secoli entrando in crisi solo alle soglie del medioevo. 6. bibliografia aa.vv. (1980) l'evoluzione della pianura emiliana durante l'età del bronzo, l'età romana e l'alto medio evo: geomorfologia ed insediamenti – padusa, 16, 53-158. aa.vv. (1985) acquedotto 2000. bologna, l’acqua del duemila ha duemila anni (catalogo della mostra). grafis edizioni, casalecchio di reno. balista c., bonfatti l. & cremaschi m. (2007) il paesaggio naturale e antropico delle valli tra spina e comacchio e le sue trasformazioni dall’età etrusca all’alto medioevo. in: berti f., bollini m. gelichi 352 fig. 23 bologna: condotto fognario romano colmato da detriti nella tarda antichità. bologna: sewer duct filled by debris during the late ancient times. j. ortalli s. & ortalli j. (edd.), genti nel delta da spina a comacchio. uomini, territorio e culto dall'antichità all'alto medioevo (catalogo della mostra). corbo, ferrara, 19-31. bentz m. & reusser c. (2008) marzabotto. planstadt der etrusker. verlag philipp von zabern, mainz am rhein. bernabò brea m. & cremaschi m. (1997) le terramare: “palafitte a secco” o “villaggi arginati”?. in: bernabò brea m., cardarelli a. & cremaschi m. (edd.), le terramare. la più antica civiltà padana (catalogo della mostra). electa, milano, 187-195. berselli a. (ed.) (1975) storia della emilia romagna. university press bologna, imola. borlenghi a. (2000) edilizia pubblica: gli acquedotti. in: marini calvani m. (ed.), aemilia, la cultura romana in emilia romagna dal iii secolo a.c. all'età costantiniana (catalogo della mostra). marsilio, venezia, 145-149. bottazzi g. (1991) programmazione ed organizzazione territoriale nella pianura bolognese in età romana ed alcuni esiti alto-medievali. in: cremonini s. (ed.), romanità della pianura. comune di s. pietro in casale, bologna, 43-113. brogiolo g.p., cremaschi m. & gelichi s. (1988) processi di stratificazione in centri urbani – archeologia stratigrafica dell’italia settentrionale, 1, 23-30. brogiolo g.p. & gelichi s. (1998) la città nell’alto medioevo italiano. archeologia e storia. laterza, roma – bari. calzolari m. (1991) modello, realtà e connotazioni degli insediamenti romani nella bassa pianura padana. in: cremonini s. (ed.), romanità della pianura. comune di s. pietro in casale, bologna, 321-335. calzolari m., corti c., gianferrari a. & giordani n. (2003) l’età romana nella pianura modenese. in: cardarelli a. & malnati l. (edd.), atlante dei beni archeologici della provincia di modena, i. pianura. all’insegna del giglio, firenze, 39-51. cardarelli a. (ed.) (2009) guida al parco archeologico e museo all'aperto della terramara di montale. nuova grafica, carpi. catarsi dall’aglio m. & dall’aglio p.l. (1991-92) le città dell'emilia occidentale fra tardoantico e altomedioevo – studi e documenti di archeologia, 7, 9-29. chevallier r. (1983) la romanisation de la celique du pô. essai d'histoire provinciale. bibliothèque des écoles françaises d'athènes et de rome, 249, 643 pp. chevallier r. (1988) geografia archeologia e storia della gallia cisalpina. 1. il quadro geografico. antropologia alpina, torino, 1988. coppa m. (1968) storia dell’urbanistica dalle origini all’ellenismo. giulio einaudi editore, torino. cremaschi m. (1997) terramare e paesaggio padano. in: bernabò brea m., cardarelli a. & cremaschi m. (edd.), le terramare. la più antica civiltà padana (catalogo della mostra). electa, milano ,107-125. cremaschi m. & gasperi g. (1988) il sottosuolo della città di modena. caratteri sedimentologici, geopedologici, stratigrafici e significato paleoambientale. in: aa.vv., modena dalle origini all'anno mille. studi di archeologia e storia, i, panini, modena, 285-303. cremonini s. (1990) inquadramento geologicoambientale della pianura bolognese in età romana. in: aa.vv., civiltà padana, archeologia e storia del territorio – iii. aedes muratoriana, modena, 93-128. cremonini s. (1991a) il torrente savena oltre i limiti dell'analisi storica. un esempio di “archeologia fluviale" – atti e memorie della deputazione di storia patria per le province di romagna, 42, 159-205. cremonini s. (1991b) una 'finestra geomorfica' d'età classica nella pianura bolognese. in: cremonini s. (ed.), romanità della pianura. comune di s. pietro in casale, bologna, 243-310. cremonini s. (1994) dati sul livello del mare in età antica dal litorale adriatico emiliano-romagnolo e settentrionale – atti e memorie della deputazione di storia patria per le province di romagna, 45, 3103. cremonini s. (1995) per un profilo delle problematiche geostoriche riminesi. in: calbi a. & susini g. (edd.), pro poplo arimenese. fratelli lega editori, faenza, 253-328. cremonini s. (2007) questioni di geomorfologia costiera del delta del po anteriormente al 1604. evidenze dalla cartografia storica – annali di ricerche e studi di geografia, 63, 3/4, 53-67. dall’aglio p.l. (1989) la centuriazione in emilia romagna e nelle marche. in: adani g. (ed.), insediamenti rurali in emilia romagna marche. amilcare pizzi ed., cinisello balsamo, 47-50. dall’aglio p.l.. (1997) considerazioni sull’intervento di marco emilio scauro nella pianura padana. in: quilici l. & quilici gigli s. (edd.), uomo acqua e paesaggio (atlante tematico di topografia antica, suppl. 2). “l’erma” di bretschneider, roma, 8693. dilke o.a.w. (1979) gli agrimensori di roma antica. edagricole, bologna. fabbri p. (1990) il paesaggio ravennate dell'evo antico. in: susini g. (ed.), storia di ravenna. i. l’evo antico. marsilio, venezia, 7-30. forte m. & von eles p. (edd.) (1994) la pianura bolognese nel villanoviano. insediamenti della prima età del ferro (catalogo della mostra). all’insegna del giglio, firenze. gros p. & torelli m. (1988) storia dell’urbanistica. il mondo romano. editori laterza, roma-bari. guarnieri c. (1987) centri urbani ed idrografia nella cisalpina. in: basso p., bertoldo g. & riera i. (edd.), la ricostruzione dell'ambiente antico attraverso lo studio e l'analisi del terreno e dei manufatti, v. padova, 73-91. guandalini f. (2001) le centuriazioni in emilia romagna. in: quilici l. & quilici gigli s. (edd.), urbanizzazione delle campagne nell’italia antica (atlante tematico di topografia antica, 10). “l’erma” di bretschneider, roma, 70-77. malnati l. & manfredi v. (1991) gli etruschi in val padana. il saggiatore, milano. malnati l. & sassatelli g. (2008) la città e i suoi limiti in etruria padana. in: camporeale g. (ed.), la città murata in etruria (atti xxv convegno di studi 353archeologia e ambiente: dominio delle acque e dominio ... etruschi ed italici). fabrizio serra editore, pisa – roma, 429-469. mansuelli g.a. (1962) i cisalpini (iii sec. a.c. – iii d.c.). sansoni, firenze. manzelli v. (2000) ravenna (città romane, 2 atlante tematico di topografia antica, suppl. 8). “l’erma” di bretschneider, roma. marini calvani m. (ed.) (2000) aemilia, la cultura romana in emilia romagna dal iii secolo a.c. all'età costantiniana (catalogo della mostra). marsilio, venezia. mauro m. (ed.) (2005) i porti antichi di ravenna, i, il porto romano e le flotte. adriapress, ravenna. ortalli j. (1993) mestieri, merci, mercati: luoghi e memorie per l'economia di bologna romana. in: scannavini r. (ed.), piazze e mercati nel centro antico di bologna. storia e urbanistica dall'età romana al medioevo al rinascimento ai giorni nostri. grafis edizioni, bologna, 251-281. ortalli j. (1995) bonifiche e regolamentazioni idriche nella pianura emiliana tra l'età del ferro e la tarda antichità. in: quilici l. & quilici gigli s. (edd.), interventi di bonifica agraria nell'italia romana (atlante tematico di topografia antica, 4). “l’erma” di bretschneider, roma, 59-86. ortalli j. (1997a) archeologia topografica: la ricostruzione dell'ambiente e dell'insediamento antico nell'esperienza di casalecchio di reno – corsi di cultura sull'arte ravennate e bizantina, 43, 565606. ortalli j. (1997b) assetto topografico e caratteri funzionali dei "suburbia" cispadani. in: studi in onore di nereo alfieri. accademia delle scienze, ferrara, 103-124. ortalli j. (1997c) evoluzione idrografica e insediamento antico dagli scavi di casalecchio di reno. in: quilici l. & quilicii gigli s. (edd.), uomo acqua e paesaggio (atlante tematico di topografia antica, suppl. 2). “l’erma” di bretschneider, roma, 351-354. ortalli j. (1999) l'insediamento residenziale urbano nella cispadana. in: ortalli j. & heinzelmann m. (edd.), abitare in città, la cisalpina tra impero e medioevo (atti del convegno – roma). dr. ludwig reichert verlag, wiesbaden, 95-119. ortalli j. (2002) la "rivoluzione" felsinea: nuove prospettive dagli scavi di casalecchio di reno – padusa, 38, 57-90. ortalli j. (2003) gli scavi di s. cristina della fondazza: note "marginali" sull'archeologia e sulla topografia di bologna per l'età antica. in: foschi p. & ortalli j. (edd.), il monastero di s. cristina della fondazza (atti del convegno – bologna). deputazione di storia patria, bologna, 61-74. ortalli j. (2005) "urbanistica" delle acque interne: problemi generali e casi particolari (la cispadana e forum corneli). in: sapelli ragni m. (ed.), studi di archeologia in memoria di liliana mercando. allemandi, torino, 175-185. ortalli j. (2008a) la prima felsina e la sua cinta. in: camporeale g. (ed.), la città murata in etruria (atti xxv convegno di studi etruschi ed italici). fabrizio serra editore, pisa – roma, 493-506. ortalli j. (2008b) l’assetto pubblico degli insediamenti cispadani nel tardo impero: la fine di un sistema. in: bocchi f. & varanini g.m., l'eredità culturale di gina fasoli (atti convegno -bolognabassano del grappa). istituto storico italiano per il medioevo, roma, 149-169. ortalli j. (2008c) l'insediamento celtico di casalecchio di reno (bologna). in: vitali d. & verger s. (edd.), tra mondo celtico e mondo italico. la necropoli di monte bibele (atti convegno roma). dipartimento di archeologia, bologna, 299-322. ortalli j. (2009) emilia archeologica. tempi e forme della romanizzazione. in: aa.vv., via emilia e dintorni. percorsi archeologici lungo l’antica consolare romana. silvana editoriale, cinisello balsamo, 71-95. ortalli j. (c. s.) case dell’agro di felsina: un modello edilizio per il governo del territorio. in: bentz m. & reusser c. (edd.), etruskisch-italische und römisch-republikanische wohnhäuser la casa etrusco-italica e la casa romana-repubblicana (atti del convegno – bonn). in corso di stampa. ortalli j. & pini l. (edd.) (2002) lo scavo archeologico di via foscolo-frassinago a bologna: aspetti insediativi e cultura materiale. all’insegna del giglio, firenze. prati l. (ed.) (1988) flumen aquaeductus. nuove scoperte archeologiche dagli scavi per l’acquedotto della romagna (catalogo della mostra). nuova alfa editoriale, bologna. ravara montebelli c. (ed.) (2002) aqua ariminensis. approvvigionamento, conduzione e utilizzo nella città romana. amir spa, rimini. sereni e. (1982) storia del paesaggio agrario italiano. laterza, roma-bari. settis s. (ed.) (1983) misurare la terra: centuriazione e coloni nel mondo romano (catalogo della mostra). panini, milano. tozzi p. (1989) la via emilia in età romana. in: aa.vv., evoluzione di un territorio. aemilia, una via, una regione. step, parma, 17-45. uggeri g. (1997) i canali navigabili nell’antico delta padano. in: quilici l. & quilici guilici s. (edd.), uomo acqua e paesaggio (atlante tematico di topografia antica, suppl. 2). “l’erma” di bretschneider, roma, 55-60. vai g.b. (1994) evoluzione del santerno attraverso la cartografia storica. in: baruzzi w. (ed.), imola e il fiume. university press bologna, imola, 86-96. veggiani a. (1990) fluttuazioni climatiche e trasformazioni ambientali nel territorio imolese dall'alto medioevo all'età moderna. in: mancini f., giberti f. & veggiani a. (edd.), imola nel medioevo, i. galeati, imola, 39-102. 354 ms. ricevuto il 21 luglio 2010 testo definitivo ricevuto il 18 ottobre 2010 ms. received: july 21, 2010 final text received: october 18, 2010 j. ortalli amq28(2)99-110 ingrassia rivisto 12_2015.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 28 (2), 2015, 99 110 influence of fluid emissions on shallow-water benthic habitats of the pontine archipelago (tyrrhenian sea, italy) michela ingrassia1,2, letizia di bella1, francesco latino chiocci1,2, eleonora martorelli2 1 department of earth science, university of rome sapienza, rome, italy 2 cnr-igag (istituto di geologia ambientale e geoingegneria), uos roma, rome, italy corresponding author: m. ingrassia <michela.ingrassia@uniroma1.it> abstract: an active fluid emission area located off the eastern coast of zannone island (western pontine archipelago) has been studied in order to investigate benthic assemblages related to vent-activity. the fluid escape feature is a giant depression (about 0.5 km2) located on the outer shelf, between 110 and130 m water depth. evidences of active emissions were detected by rov observations and sediment sampling, whereas integration of high-resolution multibeam bathymetry, backscatter and ground-truth data allowed us to characterize and identify different seafloor types (e.g., lithified seafloor and sandy sediment). moreover, the analysis of rov videos and grab samples allowed the definition of the benthic assemblages (micro and megafauna) living within the vent-areas and in the nearby seafloor. this study shows results from the first integrated analysis of the morpho-acoustic, sedimentological and biological characteristics of the northern sector of the zannone giant depression, highlighting great differences between vent and non-vent seafloor areas. in vent areas, the seafloor is characterized by high morphological complexity and peculiar benthic habitats strongly controlled by dissolution processes, indicating “extreme” conditions due to active fluid emissions. keywords: active venting; benthic assemblages; foraminifera; shallow-vents; tyrrhenian sea 1. introduction extreme marine environments (emes), as hydrothermal vents and cold seeps, have been found over a wide depth range from coastal to the abyssal zones (hovland & judd, 1988; dando et al., 1999; tarasov et al., 2005; judd & hovland 2007). the most common technology in discovering active marine fluid emission sites is the record of backscatter values in water column, even if often underestimate small-scale venting features (nakamura et al., 2013). recent progress in high-resolution swath mapping techniques and near bottom geophysical surveys (deep-tow manned submersible, remotely-operated vehicle-rov, autonomous underwater vehicle-auv) have permitted to image seafloor morphology in great detail, increasing our knowledge on fluid related features (e.g. tivey & dyment, 2010). during the last decade attention has been mainly devoted to the biological aspects related to the emes, mainly because the occurrence of specific biological communities can be used as indirect proxy to determine the chemical composition of the fluid emitted from the seafloor (sibuet & olu, 1998; sahling et al., 2002; levin & mendoza, 2007; foucher et al., 2009). besides, these particular settings may offer unique opportunities to the discovery of new marine species (takai et al., 2006; danovaro et al., 2010). moreover, micro communities inhabiting these extreme environments assume an important role both in creation and degradation of organic matter and energy, therefore they could be considered a key factor to quantify the amount of greenhouse gases affecting the oceanic chemistry (dimitrov, 2002). seafloor areas affected by hydrothermal activity are mainly found in shallow marine environment (dando et al., 1999; melwani & kim, 2008), but few complete studies about distribution of benthic assemblages have been published, e.g. in the tyrrhenian sea (panieri et al., 2003, 2005; panieri, 2006), aegean sea (dando et al., 1995a,b), south pacific ocean (kamenev et al., 1993; pichler et al., 1999; tarasov et al., 1999), north atlantic ocean (botz et al., 1999), gulf of mexico (melwani & kim, 2008) and in the shallow sub-polar region of the mid atlantic ridge (fricke et al., 1989). more studies are available for cold seep environments (sibuet & olu 1998; levin, 2005). several physical parameters, such as temperature, substrate type, number of emissions, age, concentration of gases (h2s, ch4 and h2) and precipitation of heavy metals, can affect the diversity and spatial distribution of the benthic communities (childress & fisher, 1992; dando et al., 1995b; sibuet & olu, 1998; tarasov, 1999). at shallow water sites the primary production is based both on chemosynthetic and photosynthesis processes (sorokin et al., 1998; namsaraev et al., 1994; tarasov et al., 2005) leading to the scarce occurrence of vent-obligate taxon, respect to those found in deeper sites (dando, 2010). in this paper the first integrated analysis of the morpho-acoustic, sedimentological and biological characteristics of the northern sector of the zannone giant pockmark (described by ingrassia et al., 2015a), located 3 km away from the eastern coast of zannone island (western pontine archipelago), is presented. this result together with direct observations through video-imaging and foraminiferal analysis on recovered samples allowed us to describe the influence of venting activity on sediment characteristics and on micro and mega benthic assemblages. 2. study area the study area is located about 35 km from the latium coastline in the central tyrrhenian sea (italy), on the seafloor surrounding the western pontine archipelago (fig. 1). the western pontine archipelago has a volcanic origin and is located on a structural high where meso-cenozoic basement is overlain by volcanic units of pliocene and pleistocene age (zitellini et al., 1984). the archipelago was affected by extensional tectonics due to the spreading of the tyrrhenian back arc basin (kastens & mascle, 1990), that favored volcanic activity and formation of a very steep, nw-se trending continental slope and a ne-sw oriented structural high (conti et al., 2013). two main stages of volcanism have been recognized in the history of this group of islands. the first stage occurred between 4.2-2.9 ma (cadoux et al., 2005) with the emplacement of rhyolites followed by intrusion of na-rich rhyolitic dikes in marine environment (barberi et al., 1967; savelli, 1983) with hydrothermal activity recorded at ponza island (altaner et al., 2003). subsequently, the volcanic activity was characterized by the production of rhyolites and trachytes between 1.60.9 ma (bellucci et al., 1997; cadoux et al., 2005). a narrow and steep insular shelf, with an average slope of 1°, characterizes the seafloor surrounding the western pontine archipelago. the insular shelf present a complex morphology due to the occurrence of several volcanic, biogenic buildups (martorelli et al. 2003, chiocci & martorelli, in press) and several fluid escape features (ingrassia et al., 2015a). sedimentation on the insular shelf is mainly represented by carbonate sediment composed of foraminifera, coralline algae, bryozoans, ostracods, sponge spicules etc (martorelli et al., 2011). the most important known marine biocenosis are represented by the posidonia oceanica meadows, coarse sands and fine gravels under the influence of bottom currents, coastal detritic bottom, coralligenous (martorelli et al., 2011) and presence of antipatharian corals (ingrassia et al., 2015b). the shelf break is found at a water depth ranging between 90-160 m and it is characterized by a complex trend in the southern sector, where erosive features (channels and canyons) carved the steep continental slope (chiocci et al., 2003). the continental slope is mainly characterized by the occurrence of muddy sediment and sparse volcanic outcrops (conti et al., 2013). finally two tectonicallycontrolled basins (palmarola and ventotene), characterized by high plioquaternary sedimentation rates (zitellini et al., 1984), are located at a water depth ranging between 500-800 m. 2.1. background as reported by ingrassia et al. (2015a) an active fluid emission area, named zannone giant pockmark (zgp), was discovered in 2009 (fig. 2 a and b). the zgp lies in water depth ranging between 110-130 m and it is formed by the coalescence of at least three major craters. within the zgp seafloor three main morphological sectors characterized by hummocky, irregular and regular seafloor have been defined. moreover, about 50 small pockmarks and 28 positive features (mound and cones) were found. across the northern sector of the zgp, bubble streams and acoustic plumes indicate the presence of an ongoing fluid emission activity from the seafloor. water sampling by niskin bottles highlighted the presence of co2, ch4 and c2h6 in fluid emissions. moreover, seismic profiles showed the occurrence of intense deformation of late-quaternary lowstand deposits and holocene highstand deposits, linked to the fluid emissions. 3. material and methods 3.1. acoustic data bathymetry and backscatter data were acquired by the multibeam echosounder system (kongsberg em 3002d 300 khz), during a research cruise “magic igag 10/09” carried out on november 2009 on board of the r/v maria grazia (by cnr-igag). navigation data was d-gps positioned and sound velocity parameters were collected via multiple conductivity, temperature and depth (ctd) casts. 100 fig.1 bathymetry (by gebco digital atlas) of the southern latium continental margin. red box indicate location of the study area. pa=palmarola; po=ponza; za=zannone; ve= ventotene. ingrassia m. et al. 101 fig. 2 a) shaded relief image (grid size of 5 m) of the seafloor surrounding the eastern part of zannone island, with the location of grab samples and track of video observations; b) detail of the backscatter mosaics (both sss and multibeam) obtained for the northern sector of the zgp (zannone giant pockmark); c) detail of the multibeam backscatter mosaic for the non-vent seafloor areas located on the outer insular shelf. vent-activity affecting the marine environment at zannone island (central italy) backscatter data were acquired by the eg&g 260 side scan sonar (sss) during a research cruise (magic igag 2012) carried out on february 2012 on board r/v urania (by cnr-igag). bathymetric data were post-processed using the software caris hips & sips 8.1.7. sensor data were merged and corrected for the effect of tide, attitude sensors (roll, pitch and heave) and sound velocity variation. acquisition and processing of multibeam data are detailed described in casalbore et al. (2014). for this work, digital terrain models (dtms) were produced at a resolution varying from 1 to 5 m (fig. 2a). visualization of dtms was obtained using the software global mapper 15. backscatter data were processed through the geocoder tool using the software caris hips & sips 8.1.7. this processing allowed to obtain different multibeam backscatter mosaics (pixel resolution varying from 1-0.5 m; fig. 2b and c) and an ultra-high resolution sss mosaic (0.2 pixel; fig. 2b). backscatter signatures were classified according to their textures via a qualitative description. 3.2. ground-truth data (sediment and biological evidence) sediment, biological and video data (fig. 2) were acquired during two research cruises the “s.g.n. 2001”, carried out on july 2001, and the “bolle 2014” carried out on june 2014 aboard to the r/v urania. in 2001, 68 video observations were acquired by the hyball2 rov system and in 2014 13 dives were performed using the pollux iii (gei) rov system. this rov was equipped with an underwater acoustic tracking positioning system (ultra-short baseline, usbl) that provided detailed records of the seafloor tracks. four sediment samples (tab. 1 and fig. 2) were collected with a van veen grab during the research cruise “bolle 2014”. sample locations were identified during the video transect acquisition, in order to obtain representative biological and sedimentological information in both vent and non-vent seafloor areas. on board all the samples were visually described, photographed and preserved by freezing. 3.2.1. foraminiferal faunal analysis for each of the four collected grab samples (fig. 2) a significant undistributed surface sample (0-1 cm thick) was considered for preliminary environmental characterization of the studied area by mean of living and dead benthic foraminiferal assemblages. in this respect, the sediment samples were stained and preserved in a solution of 2 g/l of rose bengal of ethanol as described by lutze & altenbach (1991) and schönfeld et al. (2012). after 15 days, the samples were wet-sieved through a 63 �m sieve and then dried at 60°c. in each sample rose bengal stained foraminifers with well-preserved tests were counted, hand-picked and identified using a binocular microscope. the classification of the species has been made on the base of recent mediterranean and extramediterranean foraminiferal literature data (jorissen, 1987, 1988; cimerman & langer, 1991; sgarrella & moncharmont-zei, 1993; sen gupta et al., 2009; frezza et al., 2010; milker et al., 2012). the species diversity was quantified using the áfisher index (fisher et al., 1943) calculated using the past (palaeontological statistics) version 1.38 data analysis package (hammer et al., 2001). 4. results integration of high-resolution bathymetry and backscatter data allowed to recognize the main characteristics of the seafloor around the sampled stations (grabs) and of the nearby seafloor areas (fig. 3). moreover, the ground-truth data (biological and sedimentological evidence) allowed us to determine the main differences between vent and non-vent areas. 4.1. vent seafloor areas herein a geophysical and sedimentological/ biological description of the two grab samples (st2bnr1 and st4bnr1, fig. 2b), located in the vent area, is given. st2bnr1 was recovered at 137 m water depth, within an elongated depression located in the northern sector of the zgp (fig. 2b and fig. 3a). this depression is 217 m long, 65 m wide and has an average slope of 10°. moderate to high intensity values and several acoustic shadows (fig. 2b and fig. 3a) characterize the seafloor surrounding the sampled station, as evidenced by the backscatter data. this grab recovered sandy sediment and pieces of hard-lithified sediment (fig. 3a) with a strong sulfur smell. rov2 shows different types of seafloor both in correspondence and around the sampled station (fig. 2a and b). to the south, the seabed is floored by sandy sediment, sometimes covered by bacterial mats, characterized by the occurrence of several small pockmarks with centimetric size (fig. 4a). one specimen of sea urchin, belonging to the family cidaridae (fig. 4b), represents the benthic megafauna. the second type of seafloor is characterized by the presence of larger depressions (fig. 4c), with occurrence of small positive cones. only few specimens of fishes, jumping on the seafloor, were observed. in the north-eastern sector the seafloor is characterized by occurrence of coarse sediment (fig. 4d). no direct evidences of fluid emissions were detected via video observations (e.g. bubble streams) on the seafloor surrounding the st2bnr1 station. however water column backscatter data show the occurrence of a 40-70 m high, well defined acoustic flare (ingrassia et al., 2015a). x-ray diffraction revealed as in this station the inorganic fraction is mainly constituted of quartz, glass, rare feldspars, native sulfur and barite. no living microfauna 102 tab. 1 list of the grab samples considered in this study (geographic coordinates). ingrassia m. et al. were observed at this station. st4bnr1 was recovered at 133 m water depth, within a complex pockmark (fig. 2a, b) composed of two small depressions characterized by a total length of 78 m, width of 65 m and average slope of 5°. within the complex pockmark the backscattered signal is homogeneous and varies between low and moderate intensities (fig. 3b); in contrast the seafloor around the rim of the pockmark is characterized by very high backscattering strength (fig. 3b). the grab recovered well sorted sandy sediment with traces of oxidation (fig. 3b). rov6 shows different types of seafloor both in correspondence and around the sampled station (fig. 2a and b). along the north-eastern flank of the complex pockmark (close to the grab station) at least six active emissions, associated to bubbles streams or cloud of fluids (fig. 4e), were observed. no continuous fluid emissions are observed on the pockmark floor that is composed of oxidized sandy sediment, characterized by centimetric (5-10 cm) circular depressions and small cones, with occurrence of widespread bacterial mats (fig. 4f). no megafauna was observed both nearby to the active emissions points and on the pockmark floor. lithified sediments, forming domal structures (fig. 4 g, h and i), were observed in correspondence of the rim of the pockmark. in some cases, these structures are characterized by presence of flange-like features, where filamentous bacteria (fig. 4h) and hydroids (fig. 4 i) are present. moreover, fish schools of anthias anthias were observed swimming in the proximity of the domal 103 fig. 3 summary of the acoustic facies (bathymetry and backscatter) and sediment characteristics for each sampled stations. vent-activity affecting the marine environment at zannone island (central italy) 104 ingrassia m. et al. structures (fig. 4 l). x-ray diffraction revealed as in this station the inorganic fraction is dominant. it is mainly constituted of quartz, glass and rare feldspars. instead, only siliceous spicules and very rare living agglutinated foraminifers represent the organic fraction. the dominant morphotypes are trochoid and elongated species mainly attributed to species pertaining to trochammina, reophax and lagenammina genera. the specimens show very small sizes with shell diameters <30 ìm, exclusively constituted of quartz particles. no porcellanaceous and hyaline tests were recorded and the dead assemblage was completely absent, as a result, faunal density and species diversity are extremely low. 4.2. non-vent seafloor areas two grab samples were collected in non-vents seafloor areas (fig. 2a and c). these samples were analyzed in order to obtain a comprehensive background of the type of habitats present in the study area. st5bnr1 and st6bnr1 samples were recovered on the outer shelf of zannone island, at about 2.5 km from the zgp, in a water depth of about 126 m (fig. 2a and c). the sampled stations are placed on a flat seafloor (fig. 2a and fig. 3c, d) characterized by average slope value of 0.7°. backscatter intensity is rather homogeneous with intermediate values (fig. 3c and d). both the samples recovered sediment composed of sandy sediment with traces of oxidization and bivalve shells (fig. 3c and d). no video observations are available in the correspondence of st5bnr1 and st6bnr1 stations. in both samples inorganic fraction is scarce and mainly constituted of quartz, calcite, and volcanic clasts. the organic fraction is very abundant; it is represented by sponge spicules, ostracods, pteropodes, briozoa, mollusk fragments and foraminifers. among these components, benthic foraminifers dominate the sediment residue. foraminiferal tests are generally well-preserved although the dead assemblage is more abundant than the living one. a total of 59 species were recognized. the species diversity performed on the total assemblage is high with á-fisher index value of 21.02. the total assemblage is characterized by asterigerinata planorbis, cassidulina spp., elphidium spp., lobatula lobatula, rosalina spp., uvigerina spp. and frequent miliolids (miliolinela spp. biloculinella spp., pseudotriloculina spp.). in detail, the living assemblage is characterized by miliolinella subrotunda, biloculinella labiata, biloculinella depressa, quinqueloculina spp., nubecularia lucifera, uvigerina mediterranea, hoeglundina elegans, cassidulina spp., spiroloculina excavata. rov dives r43, rov2 and rov8, showing the main characteristics of the non-venting areas, were acquired on the seafloor located close to the northern escarpment and along the north-western rim of the zgp (fig. 2a and b), in a water depth ranging between 84– 120 m. r43 displays occurrence of widespread biodetritic sandy sediment with a significant amount of coralline algae, e.g. pralines (fig. 5a and b), whereas no mud sediment was observed. the benthic megafauna is represented by sea urchins belonging to the families cidaridae and echinidae (fig. 5a and b). rov2 shows the occurrence of several rocky outcrops interspersed with sandy sediment along the north escarpment of the zgp (fig. 5c) with holothurians, sea stars (fig. 5d), sea urchins (cidaridae) and school of a. anthias. moreover, the video images reveal traces of anthropogenic impacts as fishing activities (fig. 5e) and presence of a lost cable (fig. 5f). finally, rov 8, located 200 m nw from the zgp (fig. 2a and b), shows occurrence of sandy sediment with a large number of sea urchins belonging to the family cidaridae. 5. discussions 5.1. non-vent vs vent seafloor areas the analysis of morphological and backscatter data as well as sedimentological and biological information derived by ground-truth data highlight significant differences between vent and non-vent areas. non-vent areas are characterized by a smooth seafloor, with low backscatter intensity due to sandy sediment without occurrence of fluid escape features. this is the normal seafloor environment for the outer shelf of the pontine seafloor, where lowstand deposits are present, as described in martorelli et al. (2011) and chiocci & martorelli (in press). this environment hosts different benthic fauna (sea urchins -cidaridae and echinidae-, holothurians, coralline algae, etc.) and school of a. anthias. here, the foraminiferal assemblages (dead and living) appear strongly diversified with high faunal density, suggesting a stable environment. on the base of the ecological characteristics of species, the assemblages can be related to mesothrophic-oligothrophic and well oxygenated bottom conditions. this is confirmed by the dominance of epifaunal (miliolids, a. mamilla, l. lobatula) and shallow infaunal species (cassidulina spp., uvigerina spp.) that usually live in environments with supply of fresh organic matter continually provide by currents (langer, 1993; hayward et al., 2013; nardelli et al., 2010; de rijk et al., 2000). similar assemblages are common and widespread on the seafloor of the whole western pontine archipelago, as shown by frezza et al. (2010). on the contrary within the vent-areas, the seafloor is characterized by a complex morphology, encompass 105 __________________________ fig. 4 selected rov-images taken in correspondence of the sampled vent-seafloor areas. a) bacterial mat on sandy sediment with occurrence of several small depressions; b) sea urchin (cidaridae) on sandy sediment; c) sandy sediment with presence of large depression; d) coarse sediment; e) cloud-fluid emission from the sandy seafloor; f) oxidized sandy sediment with occurrence of widespread bacterial mats, several centimetric circular depressions and small cones; g) domal structure with visible flange like feature; h) domal structure with filamentous bacteria; i) specimens of hydroids observed on the domal structure; l) school of a. anthias swimming in the proximity of the domal structure. vent-activity affecting the marine environment at zannone island (central italy) ing pockmarks of various size, dome and cones structures, and different types of substrata (lithified sediment, crusts, sandy sediment, etc.). the detection of lithified sediment inside the zgp and not on the nearby seafloor (non-vent areas) strengthens the interpretation of these features as vent-related crusts. according to tarasov et al. (2005), canet et al. (2006) and griffith & paytan (2012), presence of barite and native sulfur, white bacte 106 fig. 5 selected seafloor rov-images taken in correspondence of the sampled non-vent seafloor areas. a) coralline algae and sea urchin (cidaridae) on biodetritic sediment; b) biodetritic sediment with occurrence of a specimen of sea urchin belonging to the family echinida (white narrow); c) rocky outcrops interspersed with sandy sediment d) specimen of sea star on hard sediment; e) lost long-line gear on rocky outcrop; f) lost cable on biodetritic sediment. ingrassia m. et al. rial mats and several centimetric small pockmarks, provides further evidence of relevant continuous fluid emissions in this area. moreover, as indicated in section 4.1, some of these structures appear characterized by the development of flange-like features, similar in aspect to those commonly observed along the lateral side of vertical and large sulphide chimneys (kerr, 1997), formed by hydrothermal circulation in deep water settings (tivey, 2007). as no flange-like features have been reported in shallow water environment, their finding within the zgp (at about -130 m) updates the knowledge on environment condition leading the formation of these peculiar structures. as a whole, the occurrence of different seafloor types seem reflect a high complexity and variability of both seafloor morphology and sediment characteristics, that in many cases change at metric scale (e.g. transition from dome structures to pockmarking sandy sediment). the main benthic assemblages found in the ventareas are represented by widespread bacterial mats, sea urchins belonging to the family cidaridae, hydroids and presence of schools of a. anthias (fig. 4g, h, i and l). the broad presence of bacterial mats observed only within the floor of the zgp, close or directly above vent emissions, indicate that occurrence of fluid emissions in shallow-water environment plays a direct control on bacterial mats distribution; this evidence is consistent with observations obtained by levin et al. (2000) and tarasov et al. (2005). no obligate megafaunal assemblages were observed close to the vent emissions and in their proximity, actually megafauna is completely absent on vent emissions. after all, one of the common factor limiting the colonization of benthic megafauna is represented by the concentration of hydrogen sulphide (vismann, 1991). the appreciable sulfur smell detected in the st2bnr1 grab sample suggests the occurrence of fluids moderately enriched in h2s, which could be toxic for the organisms. in more distal areas from venting zones, the distribution of the megafauna appears rather similar to that observed on the non-vent seafloor; this result is in agreement with other reference studies (i.e. dando et al 1995b; thiermann et al., 1997; morri et al., 1999; tarasov et al., 1999). a different situation arise from the analyses of foraminifera that indicate major differences between vent and non-vent areas. in fact, the typical microfaunal assemblage of vent-areas is represented by oligotypic foraminifera constituted exclusively of agglutinant species. this assemblage is very different, for structure and composition, from the associations recorded at the same depth (around 126 m) in areas located outside the zgp, which are not influenced by fluid emissions. in the vent areas the abrupt decrease of faunal density and species diversity associated to the decrease in shell size of the living specimens, indicates a stressed environment unfavorable to benthic life. the exclusive presence of agglutinant species, in fact, suggests chemical and physical conditions not suitable for carbonate shell formation and/or preservation, both hyaline and porcelanaceous tests. as the fluids emitted from the seafloor, located in the northern sector of the zgp, are characterized by enrichment in co2 (ingrassia et al., 2015a), acidification of water might explain the lack of carbonate tests in the foraminiferal assemblages (uthicke et al., 2013). moreover acidification might be enhanced by local enrichment in co2 produced by bacterial activity through anaerobic methane oxidation reaction (sen gupta et al., 2009; dando, 2010; wankel et al., 2012). the lack of dead foraminiferal assemblages (both benthic and planktonic) suggests the occurrence of strong dissolution processes, confirmed by the sediment composition (only quartz) from which the organisms take and agglutinate their tests by mean of organic cement (cimerman & langer, 1991). agglutinant species, above all trochammina spp. that are the most abundant, seem to be the most resistant to the zgp stressed environment showing an opportunistic behavior. this hypothesis is supported by the record of similar assemblages found in other vent-seafloor areas located in the tyrrhenian sea (aeolian arc), although they appear more abundant and diversified (panieri et al., 2003, 2005; panieri, 2006) than those analyzed in this study. 6. conclusions in the present study the morpho-acoustic, sedimentological and biological characteristics of the northern sector of the zgp have been analyzed. results from this study highlight great differences among the morphology, sedimentology and microfauna characters between vent and non-vent seafloor areas. on the contrary, the distribution of the megafaunal assemblages highlights a different situation. in fact, the benthic megafauna observed in vent-seafloor areas seems to represent a subgroup of the typical environment condition, while megafaunal assemblages are completely absent in areas affected by active venting. in vent-areas, the benthic foraminiferal assemblages highlight the complete lack of both hyaline and porcelanaceous tests suggesting the presence of strong dissolution processes. for all these aspects the shallow water fluid emissions site (zgp) could be considered as an extreme environment and a natural laboratory for studying the effects of co2 enriched fluids on benthic communities, with particular interest for the organisms that produce calcareous skeletons. acknowledgements this research was performed in the framework of the flagship project ritmare (sp4-wp2-a1). crews of r/v urania and maria grazia are gratefully acknowledged for their precious work. we would also thank the reviewers, daniele casalbore and romana melis, and the editor andrea sposato for their valuable comments and suggestions that greatly improved the quality of the manuscript. references altaner s.p., ylagan r.f., savin s.m., aronson j.l., belkin h.e., pozzuoli a. (2003) geothermometry, geochronology, and mass transfer associated with hydrothermal alteration of a rhyolitic hyaloclastite from ponza island, italy. geochimica et cosmochimica acta, 67(2), 275-288. 107 vent-activity affecting the marine environment at zannone island (central italy) barberi s., borsi s., ferrara g., innocenti f. (1967) contributo alla conoscenza vulcanologica e magmatologica delle isole dell'arcipelago pontino. mem. soc. geol. it., 6, 581-606. bellucci. f., grimaldi m., lirer l., rapolla a. (1997) structure and geological evolution of the island of ponza, italy: inferences from geological and gravimetric data. journal of volcanology and geothermal research, 79, 87-96. botz r., winckler g., bayer r., schmitt m., schmidt m., garbe-schoenberg d., stoffers p., kristjansson j.k. (1999) origin of trace gases in submarine hydrothermal vents of the kolbeinsey ridge, north iceland. earth and planetary science letters, 171, 83-93. cadoux a., pinti d.l., aznar c., chiesa s., gillot p.y. (2005) new chronological and geochemical constraints on the genesis and geological evolution of ponza and palmarola volcanic islands (tyrrhenian sea, italy). lithos, 81, 121-151. canet c., prol-ledesma r.m., escobar-briones e., mortera-gutiérrez c., lozano-santa cruz r., linares c., cienfuegos e., morales-puente p. (2006) mineralogical and geochemical characterization of hydrocarbon seep sediments from the gulf of mexico. marine and petroleum geology, 23, 605-619. casalbore d., bosman a., martorelli e., sposato a., chiocci f.l. (2014) mass wasting features on the submarine flanks of ventotene volcanic edifice (tyrrhenian sea, italy) in: submarine mass movements and their consequences, (eds krastel et al) 6th international symposium, advances in natural and technological hazards research, 37, 285-293. doi 101007/978-3-319-00972-8 25 childress j.j., fisher, c.r. (1992) the biology of hydrothermal vent animals: physiology, biochemistry and autotrophic symbioses. oceanography and marine biology an annual review, 30, 337441. chiocci f.l., martorelli e., bosman a. (2003) cannibalization of a continental margin by regional scale mass wasting: an example from the central tyrrhenian sea. submarine mass movements and their consequences. advances in natural and technological hazards research, 19, 409416. chiocci f.l., martorelli e. (in press) note illustrative e carta geologica in scala 1:50.000 delle aree marine del foglio 413 borgo grappa. ispra. carta geologica d’italia. cimerman f., langer m.r. (1991) mediterranean foraminifera. academia scientiarum et artium slovenica, ljubljana, 30, 1-118. conti m.a., girasoli d.e., frezza v., conte a.m., martorelli e., matteucci r., chiocci f.l. (2013) repeated events of hardground formation and colonisation by endo-epilithozoans on the sedimentstarved pontine continental slope (tyrrhenian sea, italy). marine geology, 336, 184-197. dando p.r., hughes j.a., leahy y., niven s.j., taylor l.j., smith c. (1995a) gas venting rates from submarine hydrothermal areas around the island of milos, hellenic volcanic arc. continental shelf research, 15, 913-929. dando p.r., hughes j.a., thiermann f. (1995b) preliminary observations on biological communities at shallow hydrothermal vents in the aegean sea. in: parson, l.m., walker, c.l., dixon, d.r. (eds.), hydrothermal vents and processes, geological society special publication, 303-317. dando p.r., stüben d., varnavas s.p. (1999) hydrothermalism in the mediterranean sea. progress in oceanography, 44(1), 333-367. dando p.r. (2010) biological communities at marine shallow water vent and seep sites. in s. kiel, ed. springer, the netherlands. the vent and seep biota: topics in geobiology. vol. 33, 333-378. danovaro r., company j.b., corinaldesi c., d'onghia g., galil b., gambi c., gooday a.j., lampadariou n., luna g.m., luna m.g., morigi c., olu k., polymenakou p., ramirez-liodra e.r., sabbatini a., sardà f., sibuet m., tselepides, a. (2010) deepsea biodiversity in the mediterranean sea: the known, the unknown, and the unknowable. plos one, 5(8), 1-25. de rijk s., jorissen f.j., rohling e.j., troelstra s.r. (2000) organic flux control on bathymetric zonation of mediterranean benthic foraminifera. marine micropaleontology, 40, 151-166. dimitrov l.i. (2002) mud volcanoes-the most important pathway for degassing deeply buried sediments. earth-science reviews, 59(1), 49-76. fisher r.a., corbet a.s., williams c.b. (1943) the relation between the number of species and the number of individuals in a random sample of an animal population. journal of animal ecology, 12 (1), 42-58. foucher j.p., westbrook g., boetius a., ceramicola s., dupré s., mascle j., mienert j., pfannkuche o., pierre c., praeg, d. (2009) structure and drivers of cold seep ecosystems. oceanography, 22(1), 92-109. frezza v., pignatti j.s., matteucci r. (2010) benthic foraminiferal biofacies in temperate carbonate sediment in the western pontine archipelago (tyrrhenian sea, italy). journal of foraminiferal research, 40 (4), 313-326. fricke h., giere o., stetter k., alfredsson g.a., kristjansson j.k., stoffers p., svavarsson j. (1989) hydrothermal vent communities at the shallow subpolar mid-atlantic ridge. marine biology, 102, 425-429. griffith e.m., paytan a. (2012) barite in the oceanoccurrence, geochemistry and palaeoceanographic applications. sedimentology, 59(6), 1817 -1835. hammer ø., harper d.a.t., ryan p.d. (2001) past: paleontological statis-tics software package for education and data analysis. palaeontol electron, 4, 1-9. hayward b.w., sabaa a.t., grenfell h.r., neil h., bostock h. (2013) ecological distribution of recent deep-water foraminifera around new zealand. journal of foraminiferal research, 43 (4), 415-442. 108 ingrassia m. et al. hovland m., judd a.g. (1988) seabed pockmarks and seepages: impact on geology, biology and the marine environment. londonm graham & trottman ltd, pp. 293. ingrassia m., martorelli e., bosman a., macelloni l., sposato a., chiocci f.l. (2015a) the zannone giant pockmark: first evidence of a giant complex seeping structure in shallow-water, central mediterranean sea, italy. marine geology, 363, 28-51. ingrassia m., macelloni l., bosman a., chiocci f.l., cerrano c., martorelli e. (2015b) black coral (anthozoa, antipatharia) forest near the western pontine islands (tyrrhenian sea). marine biodiversity. published online 24 feb, 2015. doi: 10.1007/s12526-015-0315-y. jorissen f.j. (1987) the distribution of benthic foraminifera in the adriatic sea. marine micropaleontology, 12, 21-48. jorissen f.j. (1988) benthic foraminifera from the adriatic sea: principles of phenotypic variation. utrecht micropaleonto­logical bulletin, 37, 1-174. judd a.g., hovland m., (2007) seabed fluid flow: impact on geology, biology and the marine environment. cambridge university press, cambridge, uk, pp. 475. kamenev g.m., fedeev v.i., selin n.i., tarasov v.g., malakhov v.v. (1993) composition and distribution of macroand meiobenthos around sublittoral hydrothermal vents in the bay of plenty, new zealand. new zealand journal of marine and freshwater research, 27, 407-418. kastens k.a., mascle j. (1990) the geological evolution of the tyrrhenian sea: an introduction to the scientific results of odp leg 107. in proceedings of the ocean drilling program, scientific results (vol. 107, 3-26). college station, tx (ocean drilling program). kerr r.c. (1997) heat transfer and hydrothermal fluid flow at flanges on large seafloor sulphide structures. earth and planetary science letters, 152(1), 93-99. langer m. (1993) epiphytic foraminifera. marine micropaleontology, 20, 235-265. levin l.a., james d.w., martin c.m., rathburn a.e., harris l.h., michener r.h. (2000) do methane seeps support distinct macrofaunal assemblages? observations on community structure and nutrition from the northern california slope and shelf. marine ecology progress series, 208, 21-39. levin l.a. (2005) ecology of cold seep sediments: interactions of fauna with flow, chemistry, and microbes. oceanography and marine biology annual review, 43, 1-46. levin l.a., mendoza g.f. (2007) community structure and nutrition of deep methane-seep macrobenthos from the north pacific (aleutian) margin and the gulf of mexico (florida escarpment). marine ecology, 28(1), 131-151. lutze g., altenbach a. (1991) technik and signifikanz der lebendfärbung benthischer foraminiferen mit bengalrot. geologisches jahrbuch a128, 251265. martorelli e., chiocci f.l., conte a.m., bellino m., bosman a., (2003) affioramenti vulcanici sottomarini dell’arcipelago pontino occidentale: caratteri petrologici e morfoacustici. atti del 4° forum italiano di scienze della terra fist geoitalia 2003 bellaria, 16-18/9/2003. martorelli e., d’angelo s., fiorentino a., chiocci f.l. (2011) non-tropical carbonate shelf sedimentation. the archipelago pontino (central italy) case history, in: p.t. harris, e.d. baker (eds.). seafloor geomorphology as benthic habitats, elsevier, amsterdam (chapter 31), 449-454. melwani a.r., kim s.l. (2008) benthic infaunal distributions in shallow hydrothermal vent sediments. acta oecologica, 33(2), 162-175. milker y., & schmiedl g. (2012) a taxonomic guide to modern benthic shelf foraminifera of the western mediterranean sea. palaeontologia electronica,15 (2), 1-134. morri c., bianchi c.n., cocito s., peirano a., de biasi a.m., aliani s., pansini m., boyer m., ferdeghini f., pestarino m., dando p. (1999) biodiversity of marine sessile epifauna at an aegean island subject to hydrothermal activity: milos, eastern mediterranean sea. marine biology, 135, 729-739. nakamura k., toki t., mochizuki n., asada m., ishibashi j.i., nogi y., yoshikawa s., miyazaki j.i., okino, k. (2013) discovery of a new hydrothermal vent based on an underwater, high-resolution geophysical survey. deep sea research part i: oceanographic research papers, 74, 1-10. namsaraev b.b., bonch-osmolovskaya e.a., kachalkin v.i., miller yu.m., propp l.n., tarasov v.g. (1994) microbiological processes of circulation of carbon in shallow-water vents of the southwest pacific. microbiology, 63, 100-111. nardelli m.p., jorissen f.j., pusceddu a., morigi c., dell’anno a., danovaro r., de stigter h.c., negri a. (2010) living benthic foraminiferal assemblages along a latitudinal transect at 1000m depth off the portuguese margin. micropaleontology, 56 (3-4), 323-344. panieri g., gamberi f., marani m., barbieri r. (2005) benthic foraminifera from a recent, shallow-water hydrothermal environment in the aeolian arc (tyrrhenian sea). marine geology 218, 207-229. panieri g., barbieri r., gamberi f., marani m. (2003) hydrothermal vents in the aeolian arc: effects on benthic foraminifera. in egs-agu-eug joint assembly 6-11 april, nice (france). panieri g. (2006) the effect of shallow marine hydrothermal vent activity on benthic foraminifera (aeolian arc, tyrrhenian sea). the journal of foraminiferal research, 36(1), 3-14. pichler t., veizer j., hall g. e. (1999) the chemical composition of shallow-water hydrothermal fluids in tutum bay, ambitle island, papua new guinea and their effect on ambient seawater. marine chemistry, 64(3), 229-252. sahling h., rickert d., lee r.w., linke p., suess e. (2002) macrofaunal community structure and sulfide flux at gas hydrate deposits from the cascadia convergent margin, ne pacific. marine ecology progress series, 231, 121-138. 109 vent-activity affecting the marine environment at zannone island (central italy) savelli c. (1983) età k/ar delle principali manifestazioni riolitiche dell'isola di ponza. rendiconti della società geologica italiana, 6, 39-42. schönfeld j., alve e., geslin e., jorissen f., korsun s., spezzaferri s. and members of the fobimo group (2012) the fobimo (foraminiferal biomonitoring) initiative towards a standardised protocol for soft-bottom benthic foraminiferal monitoring studies. marine micropaleontology, 94-95, 1 -13. sen gupta b.k., lobegeier m.k. and smith l.e. (2009) foraminiferal communities of bathyal hydrocarbon seeps, northern gulf of mexico: a taxonomic, ecologic, and geologic study. louisiana state university coastal marine institute louisiana, pp. 178. sgarrella f., moncharmont-zei m. (1993) benthic foraminifera of the gulf of naples (italy): systematics and autoecology. bollettino della società paleontologica italiana, 32(2), 145-264. sibuet m., olu k. (1998) biogeography, biodiversity and fluid dependence of deep-sea cold-seep communities at active and passive margins. deep sea research part ii: topical studies in oceanography, 45(1), 517-567. sorokin yu.i., sorokin p.yu., zakuskina o.yu. (1998) microplankton and its functional activity in zones of shallow hydrotherms in the western pacific. j. plankton research, 20, 1015-1031. takai k., nakagawa s., reysenbach a.l., hoek j. (2006) microbial ecology of midocean ridges and back-arc basins. in: christie, d.m., fisher, c.r., lee, s.-m., givens, s. (eds.), back-arc spreading systems-geological, biological, chemical, and physical interactions. geophysical monograph series, 166. american geophysical union, washington, dc, 185-213 tarasov v.g., gebruk a.v., shulkin v.m., kamenev g.m., fadeev v.i., kosmynin v.n., malakhov v.v., starynin d.a., obzhirov a.i. (1999) effect of shallow-water hydrothermal venting on the biota of matupi harbour (rabaul caldera, new britain island, papua new guinea). continental shelf research, 19, 79-116. tarasov v.g., gebruk a.v., mironov a.n., moskalev l. i. (2005) deep-sea and shallow-water hydrothermal vent communities: two different phenomena? chemical geology, 224(1), 5-39. thiermann f., akoumianaki i., hughes j.a., giere o. (1997) benthic fauna of a shallow-water gaseohydrothermal vent area in the aegean sea (greece). marine biology, 128, 149-159. tivey m.k. (2007) generation of seafloor hydrothermal vent fluids and associated mineral deposits. oceanography, 20(1), 50-65. tivey m.a., dyment j., (2010) the magnetic signature of hydrothermal systems in slow-spreading environments. in: rona, p.a., devey, c.w., dyment, j., murton, b.j. (eds.), diversity of hydrothermal systems on slow spreading ridges. geophysical monograph series 188. american geophysical union, washington, dc, 43-66. uthicke s., momigliano p., fabricius k.e. (2013) high risk of extinction of benthic foraminifera in this century due to ocean acidification. scientific reports, 3, 1-5. doi: 10.1038/srep01769. vismann b. (1991) sulfide tolerance: physiological mechanisms and ecological implications. ophelia, 34(1), 1-27. wankel s.d., adams m.m., johnston d.t., hansel c.m., joye s.b., girguis p.r. (2012) anaerobic methane oxidation in metalliferous hydrothermal sediments: influence on carbon flux and decoupling from sulfate reduction. environmental microbiology, 14(10), 2726-2740. zitellini n., marani m., borsetti a. (1984) post-orogenic tectonic evolution of palmarola and ventotene basins (pontine archipelago). memorie della società geologica italiana, 27, 121-131. ms. received: may 18, 2015 final text received: june 10, 2015 110 ingrassia m. et al. i travertini delle terme di s.giovanni (rapolano terme, appennino settentrionale) e loro implicazione neotettonica andrea brogi1*, enrico capezzuoli1, anna gandin1 1dipartimento di scienze della terra, università di siena, via laterina, 8. 53100 siena; *corresponding author: e-mail: brogiandrea@unisi.it: tel. 0577233972; fax: 0577233938 riassunto: a. brogi, e. capezzuoli & a. gandin, i travertini delle terme di s.giovanni (rapolano terme, appennino settentrionale) e loro implicazione neotettonica (it issn 0394-3356, 2007). lo studio dei travertini affioranti nell’area di s.giovanni (rapolano terme) e dell’assetto geologico dell’area ha permesso di riconoscere un importante controllo tettonico, durante il quaternario, nella deposizione di queste rocce calcaree. esse sono state depositate intorno a sorgenti termali attive in periodi diversi, a partire da 24±3 ka. attualmente la deposizione del travertino è molto scarsa ed è collegata a sorgenti di modesta portata a causa della captazione delle acque nello stabilimento termale. il deposito di travertino raggiunge il suo massimo spessore (25 metri) nell’area archeologica di campo muri, dove anche oggi è attiva una cava per il reperimento di travertino per uso ornamentale. la deposizione dei travertini più antichi sembra derivare da una o più sorgenti, in coincidenza della mofeta del bossoleto, una dolina a pianta circolare dal diametro di circa 80m dalla quale oggi fuoriesce solo abbondante co2 unitamente ad altri gas venefici. tale sorgente era collocata sulla superficie di un terrazzo fluviale collegato con l’evoluzione idrografica del fiume ombrone. l’attività sorgiva ha permesso la deposizione di calcare che ha ricoperto, in parte, i depositi fluviali e quelli che costituivano il loro substrato, rappresentato dai sedimenti marini limoso-argillosi del pliocene medio. i depositi pliocenici e quelli alluvionali quaternari, così come i travertini che li ricoprono, sono dislocati, per una decina di metri al massimo, da una faglia diretta orientata in direzione ono-ese. una serie di piccole sorgenti allineate lungo un tratto della faglia ha dato origine ad un elemento morfo-tettonico (fissure-ridge), lungo circa 250 metri, a seguito della deposizione di travertino. la faglia, sicuramente più recente di 24±3 ka, età più antica dei travertini dislocati, può essere ritenuta potenzialmente attiva anche oggi per due motivi: a) vi è una evidente attività idrotermale che indica la presenza di fratture beanti non ancora ostruite da minerali di neoformazione; b) i travertini depositati nel marzo 2003 sono stati localmente fessurati e dislocati di qualche millimetro. queste evidenze non solo hanno importanti implicazioni di carattere neotettonico per l’area di rapolano terme e per il margine orientale del bacino di siena, ma sono indicative anche dell’esistenza di probabili faglie attive e dunque potenzialmente sismogenetiche. abstract: a. brogi, e. capezzuoli & a. gandin, travertines at terme san giovanni (rapolano terme, northern apennines) and their neotectonic implications. (it issn 0394-3356, 2007). the travertines cropping out in the s.giovanni terme area (rapolano terme) were deposited from thermal springs with different ages, active from 24±3 ka. presently, the travertine deposition scarcely occurs. it is related to thermal springs with scarce flow due to the hot water pumped by the thermal resort. the travertines are better exposed in the campo muri archaeological area where they are exposed up to 25m in thickness. here a quarry is presently active. the most ancient travertines were deposited from thermal springs, presently inactive, and coinciding with the bossoleto mofet. this is a circular doline with diameter of about 80m, from which the co2 and other poisonous gas rise up. this thermal spring was located on a fluvial terrace developed together with the hydrological evolution of the ombrone river. the travertine deposited from these thermal springs overlies on the alluvial deposits and bedrock here represented by the middle pliocene marine clays. these sediments and the alluvial deposits, as well as the travertines, were dissected by a normal fault, wnw-ese striking, characterised by about 10 meters of displacement. along the trace of this fault a travertine fissure-ridge, about 250 meters long, developed. the fault, younger than 24±3 ka, could be considered as presently active for the reason that: a) a widespread hydrothermal activity is concentrated along the trace of the fault, suggesting open fractures within the damage zone; b) the travertines deposited in march 2003 were fissured and displaced of some millimetres. a parallel normal fault has been recognised north of the travertine fissure-ridge. its kinematics has been inferred in jurassic rocks affected by the fault. fault activity controlled hydrothermal circulation, as attested by three main thermal springs presently inactive, aligned along the fault trace, and related travertine deposits. faults produced upwelling of hydrothermal fluids which show peculiar geochemical features with respect to all the fluids flowing from all the thermal springs occurring in the rapolano area and surroundings. this is indicative for a different fluid pathway which can be explained considering the structural setting and the deeply occurrence of a structural high formed by carbonate rocks coinciding with an overturned and detached anticline. this structural high represents a reservoir supplied by fluids migrating along the detachment surface of the fold and thus with a different provenance. all these evidences, symptomatic of active faulting, indicate neotectonics in the rapolano terme area and the eastern side of the siena basin. parole chiave: neotettonica, dorsale di travertino, circolazione di fluidi, sorgenti termali, appennino settentrionale. keywords: neotectonics, travertine fissure-ridge, fluid flow, hot-springs, northern apennines. il quaternario italian journal of quaternary sciences 20(2), 2007 107-124 1. introduzione negli ultimi decenni lo studio dei depositi continentali carbonatici ed in particolare dei travertini ha subito un importante incremento, grazie allo sviluppo di nuove tecnologie d’indagine ed all’acquisizione di nuove metodologie di studio. la geochimica isotopica, per esempio, applicata ai depositi di travertino può fornire informazioni sul paleoclima, sulla origine e provenienza delle acque termominerali da cui hanno avuto origine, sul loro percorso di risalita e sui processi di interazione del fluido con le rocce attraversate (livnat & 108 a. brogi, e. capezzuoli & a. gandin kronfeld, 1985; janssen et al., 1999; kharaka et al., 2000; minissale et al. 2000, 2002a, 2002b, martìnalgarra et al., 2003; du et al., 2005). da pochi anni a questa parte, tuttavia, i travertini collegati alle sorgenti termominerali sono considerati anche ottimi elementi per studi di natura tettonica, principalmente riguardanti l’attività di faglie distensive o trascorrenti (hancock et al., 1999; altunel, 2005). infatti, proprio per la loro natura, i travertini si depositano in prossimità di sorgenti termali strettamente collegate con la presenza di fratture nel substrato, attraverso le quali i fluidi idrotermali possono risalire verso la superficie (curewitz & karson, 1997; hancock et al., 1999 cum bibl). tali fratture, infatti, sviluppate in risposta a sollecitazioni tettoniche, danno luogo ad una permeabilità secondaria che può permettere la circolazione di fluidi in aree caratterizzate da un gradiente geotermico anomalo e quindi favorire la loro emergenza in superficie. tuttavia, l’alto potere incrostante delle acque termominerali in circolazione, se sovrassature, può causare, in breve tempo, il riempimento e l’occlusione delle fratture mediante la deposizione di minerali di neoformazione (self-sealing) (bruhn et al., 1990). ne consegue che la circolazione idrotermale può manifestarsi durante periodi relativamente brevi, la cui durata è funzione della salinità dei fluidi. inoltre, anche l’attività tettonica gioca un ruolo fondamentale per la durata dei sistemi idrotermali. le continue sollecitazioni dovute all’attività prolungata nel tempo delle faglie, così come la sismicità ad esse collegate, possono garantire la continuità di ampliamento di fratture beanti, favorendo la circolazione idrotermale anche per lunghi periodi. per questo motivo idrotermalismo ed attività tettonica costituiscono un binomio inscindibile (altunel & hancock, 1993a; curewitz & karson, 1997; hancock et al., 1999; altunel, 2005). ne consegue che i travertini collegati alle sorgenti termali costituiscono ottimi indicatori tettonici e la loro età di deposizione diviene indicativa per quella dell’attività tettonica (hancock et al., 1999; altunel, 2005). l’analisi morfologica dei travertini, così come la loro collocazione, possono insieme fornire importanti informazioni anche sulla geometria e cinematica delle faglie. numerosi studi (altunel & hancock, 1993a, 1993b; cakir, 1999; hancock et al., 1999; atabey 2002) condotti in varie parti del mondo, infatti, hanno messo in evidenza come le sorgenti idrotermali siano collocate lungo tratti ben precisi di faglie o fratture ad esse associate, e come la loro collocazione rispetto alle strutture possa fornire importanti informazioni sulla cinematica delle faglie (fig. 1). le travertine fissure-ridge (hancock et al., 1999), in particolare, sono elementi morfo-strutturali collegati alla deposizione del travertino che possono fornire molteplici informazioni di carattere strutturale. esse, infatti, sono collegate a sorgenti idrotermali allineate lungo una frattura, che consentono la deposizione di travertino con geometria centrifuga rispetto alla zona di emergenza. la progressiva deposizione di travertino porta alla formazione di un rilievo (ridge), generalmente simmetrico, che può raggiungere la lunghezza di svariate centinaia di metri, la larghezza di qualche decina di metri e l’altezza di 1020 metri. sulla sommità di tale rilievo è presente una fessura più o meno larga (fino a qualche metro), che coincide precisamente con la frattura del substrato lungo la quale risalgono le acque termali. in varie parti del mondo (turchia, usa, kenya ecc…) sono descritte travertine fissure-ridge fossili, cioè strutture in corrispondenza delle quali non avviene più circolazione e quindi deposizione di travertino. tali strutture testimoniano una attività idrotermale avvenuta in passato ed il loro studio può contribuire alla ricostruzione dell’assetto tettonico ed idrogeologico da cui hanno avuto origine. esempi di fissure-ridge attive, invece, sono molto rari e di notevole importanza perché la loro presenza può indicare l’attività di faglie e quindi l’esistenza di strutture potenzialmente attive. in questo lavoro vengono descritte le facies deposizionali e le implicazioni tettoniche dei travertini presenti nell’area termale di s.giovanni, presso rapolano terme (fig. 2), ed in particolare un esempio di dorsale (travertine fissure-ridge) attiva. tale struttura, descritta da vari autori dal punto di vista sedimentologico e geochimico (cipriani et al., 1972; guo & riding, 1992, 1994; 1998; andrews & riding, 2001; fouke, 2001; minissale et al., 2002a), ha un importante significato strutturale ed implicazioni neotettoniche che permettono di riconsiderare il quadro strutturale del margine orientale del bacino di siena, dove tale struttura si colloca, e di porre l’attenzione su un’area che dal punto di vista della pericolosità geologica e del rischio sismico dovrebbe essere presa maggiormente in considerazione. fig. 1 rapporti tra la geometria e cinematica delle faglie e la collocazione di sorgenti termali la cui presenza è dovuta a circolazione idrotermale lungo zone permeabili di faglia. in grigio i depositi di travertino. 1) le sorgenti termali si collocano in corrispondenza della terminazione della faglia (fault tip), siano esse trascorrenti o dirette; 2) le sorgenti si collocano in corrispondenza di zone di raccordo tra faglie trascorrenti; 3) le sorgenti termali si collocano in corrispondenza dell’incontro di tre faglie trascorrenti; 4) le sorgenti termali si collocano all’intersezione tra faglie di età diversa; 5) le sorgenti termali si collocano in corrispondenza di alcuni tratti lungo la traccia di una faglia diretta (da curewitz & karson, 1997 con modifiche). relationships between geometry, kinematics and location of the thermal springs due to the hydrothermal circulation along the fault zones. the grey colour indicated the travertine masses; 1) the thermal springs are located in correspondence of the tip points of both normal and strike slip faults; 2) the thermal springs are located in the relay zones of strike-slip faults; 3) the thermal springs are located at the strike-slip faults intersection; 4) the thermal springs are located where normal faults have been dissected by a new generation of faults; 5) the thermal springs are located along the trace of a normal fault (after curewitz & karson, 1997 modified). 2. geologia dell’area di rapolano terme l’area di rapolano terme (fig. 2) si colloca in un tratto del margine orientale del bacino neogenico-quaternario di siena, depressione strutturale (graben di siena; in costantini et al., 1982) collegata all’attività tettonica distensiva miocenico-pliocenica (martini & sagri, 1993). tale depressione strutturale è stata interpretata da alcuni autori anche come thrust-top basin collegato allo sviluppo di thrust crostali attivi fino al pleistocene (finetti et al., 2001; bonini & sani, 2002). tuttavia la maggior parte degli autori sono concordi nel ritenere che il bacino di siena, così come la sua prosecuzione meridionale (bacino di radicofani) siano collegati con l’attività tettonica distensiva miocenico-quaternaria (costantini et al., 1982; bertini et al., 1991; baldi et al., 1994; liotta, 1994, 1996, liotta & salvatorini, 1994; mantovani et al., 1995, 1997; dallmeyer & liotta, 1998; acocella et al., 2002; brogi et al., 2005b; pascucci et al., 2005; collettini et al., 2006; brogi & liotta, 2006; viti et al., 2006) come dettagliatamente discusso in brogi et al., (2005a,b), brogi (2006) e brogi & liotta (2006). il margine orientale di tale bacino è rappresentato da un importante elemento morfo-strutturale, che nell’area di rapolano è noto in letteratura come dorsale rapolano-trequanda (losacco, 1952; losacco & del giudice, 1958; lazzarotto, 1973; brogi et al., 2002). tale dorsale, a sua volta, costituisce il tratto di una continua struttura positiva, orientata in direzione media nnw-sse, nota come dorsale monti del chianti – monte cetona (bertini et al., 1991) (fig. 2a). essa è costituita principalmente dalle formazioni appartenenti alla successione toscana non metamorfica che, nell’area di rapolano terme, è rappresentata da rocce di età 109i travertini delle terme di s. giovanni ... compresa tra il triassico superiore ed il miocene inferiore (calcari a rhaetavicula contorta – macigno) (losacco & del giudice, 1958; lazzarotto, 1973; costantini et al., 1982; brogi et al., 1999; 2002) (fig. 3). le rocce appartenenti alla successione toscana sono state intensamente deformate durante la tettogenesi dell’appennino settentrionale, ed hanno così registrato le deformazioni collegate con l’intera evoluzione tettonica. le rocce affioranti nella dorsale rapolanotrequanda sono separate dai depositi di riempimento del bacino di siena, principalmente costituiti da argille, sabbie, arenarie, ghiaie e conglomerati di ambiente marino, da una importante faglia diretta immergente verso ovest, orientata circa parallelamente alla dorsale stessa (costantini et al., 1982; barazzuoli et al., 1991; brogi et al., 1999). tale faglia, nota in letteratura come faglia di rapolano, è stata attiva fino al pliocene medio (brogi, 2002; brogi et al., 2005c) e risulta, quindi, a tratti sepolta dai depositi più recenti. ne consegue che la sua traccia in superficie è di difficile localizzazione, sebbene l’allineamento di sorgenti di acque termali e gas ne permettano l’individuazione (brogi et al., 1999) (fig. 4). i depositi continentali di età pleistocenica ed olocenica sono rappresentati da ghiaie, sabbie e limi lacustri e fluvio-lacustri a cui sono associate placche di travertino con le quali mostrano rapporti eteropici. nel loro insieme, i depositi continentali quaternari ricoprono sia i depositi neogenici marini sia le rocce della successione toscana. 2.1 i travertini dell’area di rapolano i travertini presenti nell’area di rapolano terme costituiscono estesi affioramenti che ricoprono un’area fig. 2 a) collocazione dell’area di studio; il rettangolo indica l’area ingrandita in b; b) schema geologico dell’area di rapolano e della dorsale di rapolano-trequanda. il rettangolo illustra l’area riportata in figura 4. a) location of the study area; the black rectangle indicates the enlarged area in b; b) geological sketch map of the rapolano area and rapolano-trequanda ridge. the black rectangle indicates the enlarged area given in figure 4. 110 di circa 14 km2 sotto forma di placche isolate, collocate principalmente lungo la traccia della faglia di rapolano (brogi et al., 1999) (fig. 4). in altri casi, affioramenti ridotti di travertino sono localizzati in prossimità di faglie minori. le placche più estese e spesse compaiono nell’area di serre di rapolano e sono ancora oggi interessate da una intensa attività estrattiva finalizzata principalmente al reperimento di travertino come pietra ornamentale. l’attività estrattiva del travertino nell’area in esame è attestata almeno dal periodo etrusco. il processo di estrazione, notevolmente intensificato negli ultimi decenni e realizzato mediante tagli effettuati con il filo elicoidale e diamantato, ha permesso l’esposizione di ampi fronti di cava che mettono in evidenza la sovrapposizione di diverse generazioni di episodi deposizionali di travertino che formano corpi complessi, caratterizzati da discordanze talvolta angolari e spesso separati da paleosuoli e/o colluvi fino a qualche metro di spessore (fig. 5). i diversi eventi deposizionali, caratterizzati da facies che denotano ambienti di sedimentazione differenti, suggeriscono la presenza di numerose sorgenti associate a bacini palustri isolati, da esse alimentate. le litofacies che costituiscono questi corpi sedimentari, assai variabili da luogo a luogo, sono state descritte nei lavori di cipriani et al. (1972), guo & riding (1992), (1994), (1998), (1999) ai quali si rimanda per un maggior approfondimento. tuttavia, sui travertini di rapolano manca ancora uno studio stratigrafico paleombientale/paleogeografico e dati cronostratigrafici completi. recenti lavori di geocronologia effettuati su alcuni intervalli relativi ai depositi affioranti nella cava attiva, collocata nell’area archeologica di campo muri (nord dell’area termale di s.giovanni), hanno permesso di riferire al pleistocene superiore-olocene (24±3 ka – attuale, carrara et al., 1998). tuttavia l’età dell’insieme dei depositi rimane incerta. più generalmente tutti i travertini presenti nell’area di rapolano sono stati r iferit i al pleistocene-olocene sulla base di studi macropaleontologici basati su conchiglie di gasteropodi polmonati, ossa di mammiferi e soprattutto filliti, rinvenute in modo sporadico in cave differenti. l’età quaternaria dei travertini, comunque, è indicativa di tettonica recente che avrebbe caratterizzato l’area di rapolano e quindi il margine orientale del bacino di siena (brogi et al., 2005a). le relazioni tra le strutture distensive ed i depositi di travertino nell’area di rapolano sono state descritte in recenti lavori (brogi, 2002; 2004) che sottolineano come i depositi di travertino siano principalmente collocati all’intersezione di faglie con prevalente movimento verticale, attive durante il quaternario, con la faglia di rapolano, più vecchia ed orientata circa ortogonalmente rispetto alle prime (fig. 4). 3. i travertini di campo muri e dell’area termale di s.giovanni campo muri è una importante località archeologica collocata qualche centinaio di metri a nord dello stabilimento termale di s.giovanni (fig. 6). presso campo muri l’attività estrattiva del travertino ha riportato alla luce un insediamento di epoca etrusco-romana (lecchini & mazzini, 1986) (iii sec. a.c – iv sec. d.c.) sviluppatosi attorno ad emergenze termali, rappresentate per lo più da una sorgente (buca delle fate) oggi non più attiva (a in figura 6), venerata ed utilizzata per scopi ludici e terapeutici. la cava di campo muri offre una buona opportunità per lo studio dei rapporti geometrici e cronologici dei corpi travertinosi presenti in quest’area. l’attività estrattiva interessa un deposito di travertino spesso fino a circa 25 metri che costituisce il riempimento di una valle orientata in direzione no-se (carrara et al., 1998), coincidente circa con l’attuale corso del fosso nibbiaia (fig. 6). le sorgenti termali che hanno permesso la deposizione dei travertini più antichi osservabili in cava sembra fossero collocate in corrispondenza degli attuali stabilimenti termali di s.giovanni terme. in partifig. 3 rapporti tettono-stratigrafici tra i depositi neogenicoquaternari e la successione toscana. sigle: dq – depositi continentali quaternari; tr – travertini; ps-pc – sabbie e conglomerati marini del pliocene inferiore-medio; pa – argille e argille sabbiose del pliocene inferiore-medio; mac – macigno; sca – scaglia toscana; mai – maiolica; apt – calcari ad aptici; rad – diaspri; pod – marne a posidonomya; sel – calcare selcifero; rsa – calcare rosso ammonitico; mas – calcare massiccio; cre – calcare a rhaetavicula contorta. relationships between the neogene-quaternary deposits and the tuscan nappe. symbols: dq – quaternary continental deposits; tr – travertines; ps-pc – early-middle pliocene marine sands and conglomerates; pa – early-middle pliocene clays and sandy clays; mac – macigno fm; sca – scaglia toscana fm; mai – maiolica fm; apt – calcari ad aptici fm; rad – diaspri fm; pod – marne a posidonomya fm; sel – calcare selcifero fm; rsa – calcare rosso ammonitico fm; mas – calcare massiccio; cre – calcare a rhatavicula contorta. a. brogi, e. capezzuoli & a. gandin 111 colare, è possibile ipotizzare, con buona approssimazione, che la sorgente più importante coincidesse con l’attuale mofeta del bossoleto, situata in una dolina dal diametro di circa 80m e profonda 10m, dalla quale fuoriesce abbondante co2 (99%) unitamente ad altri gas venefici (1%) (h2s e so2) (van gardingen et al., 1997). la mofeta del bossoleto, infatti, si trova nella parte morfologicamente più elevata dell’area suggerendo che quella doveva essere l’area sorgente delle acque termali. questa ipotesi è confermata anche dalla giacitura degli strati di travertino che sono inclinati con disposizione centrifuga rispetto alla mofeta ed in particolar modo immergono verso le aree morfologicamente depresse di campo muri (verso nord), dove scorre il fosso nibbiaia, ed il borro di canatoppa (verso sud) (fig. 6). la mofeta del bossoleto è collocata su di un terrazzo fluviale sviluppato a seguito dell’evoluzione idrografica del fiume ombrone che scorre pochi chilometri ad ovest di questa area (fig. 6). tale terrazzo costituisce una superficie morfologicamente piatta, collocata alla quota media di 280 metri sul livello del mare. essa è costituita da depositi fluviali principalmente limoso-sabbiosi a cui s’intercalano livelli di calcari incrostanti (fig. 7) che, nell’area delle terme di s.giovanni raggiungono lo spessore di 15-20 metri. tali depositi poggiano direttamente sulle argille marine del pliocene medio del bacino di siena. le manifestazioni termali collegate con l’antica sorgente del bossoleto hanno permesso la deposizione di travertino che ha ricoperto parzialmente la superficie terrazzata (fig. 6). allo stesso tempo, la presenza delle due valli orientate in direzione no-se, attualmente fig. 4 schema geologico dell’area di rapolano; i principali depositi di travertino e le attuali sorgenti termali si collocano lungo la traccia della faglia di rapolano laddove questa è stata dislocata da faglie circa ortogonali, di età quaternaria (da brogi, 2004). geological sketch map of the rapolano area; the travertine deposits and the present thermal springs are located along the rapolano fault where this latter has been dissected by quaternary, near orthogonal faults (from brogi, 2004). i travertini delle terme di s. giovanni ... 112 coincidenti con quella del fosso di nibbiaia e del fosso di canatoppa, hanno influito notevolmente sul deflusso delle acque e sulla conseguente deposizione del travertino. questo ultimo, infatti, ha riempito quasi totalmente la paleovalle del fosso di nibbiaia ed in parte quella del borro di canatoppa. l’evoluzione paleogeografica e paleoambientale dei travertini presenti nell’area delle terme di s.giovanni è stata dettagliatamente ricostruita da carrara et al. (1998) sulla base di osservazioni effettuate nei fronti della cava di campo muri. la sezione studiata da carrara et al. (1988), ben esposta nel margine occidentale della cava (fig. 8), è collocata nel punto più spesso del deposito di travertino ed ha permesso, così, l’analisi di tutti gli eventi deposizionali qui presenti. la successione carbonatica risulta discontinua, poichè nei fronti di cava si riconoscono diversi livelli calcarei separati da paleosuoli e colluvi indicativi di periodi di stasi dell’attività deposizionale dei travertini. lo studio geocronologico basato su datazioni 230th/234u e sugli isotopi del carbonio ha permesso di attribuire un’età di 24±3 ka ai depositi di travertino più antichi affioranti. tali travertini, tuttavia, costituiscono il punto più basso esposto nella cava, ma non costituiscono la base del giacimento che si trova a pochi metri sotto al piano di cava. le datazioni effettuate da carrara et al. (1998), infatti, hanno messo in evidenza un intervallo di tempo piuttosto lungo (24±3 9±1.7 ka) caratterizzato da una sedimentazione sub-aerea, sostanzialmente continua, che avrebbe permesso la deposizione della massa più importante di travertino (tr.d.a1 in figura 8). a questo episodio sarebbe seguito un evento erosivo, perdurato qualche migliaia di anni, testimoniato da una intensa brecciatura dei livelli di travertino più superficiali. ad esso è seguito nuovamente la deposizione di travertino (tr.d.a2 in figura 8) in un periodo di tempo, compreso tra 6.7±1.4 e 3.24±0.55 ka, caratterizzato da un evento alluvionale molto importante che ha causato la deposizione, nella parte alta, di uno spessore di qualche fig. 5 le pareti tagliate a filo elicoidale delle numerose cave presenti nell’area di rapolano permettono di riconoscere l’architettura dei depositi di travertino. si riconoscono diversi episodi deposizionali separati da discordanze angolari e da depositi colluviali e paleosuoli. the quarry fresh-cuts occurring in the rapolano area allow to recognise the internal architecture of the travertine deposits. we can recognise different depositional episodes separated by angular unconformities, colluvial deposits and paleosols. fig. 6 schema geomorfologico dell’area delle terme di s.giovanni. il significato di a, b e c è riportato nel testo. geomorphologic sketch of the terme s.giovanni area. a, b and c points are discussed in the text. metro di sedimenti alluvionali. la deposizione di travertino è continuata, poi, ininterrottamente fino al iii sec. a.c. – iv sec. d.c., periodo al quale vengono riferiti i reperti di un insediamento etrusco-romano presente a. brogi, e. capezzuoli & a. gandin nell’area (lecchini & mazzini, 1986). in questa fase il flusso delle acque era regimentato per uso termale e la deposizione del travertino fu quindi interrotta. tali reperti, tuttavia, furono in parte ricoperti da travertino a seguito dell’abbandono del sito, a testimonianza di una attività termale prolungata nel tempo (fig. 9a). durante il periodo dell’insediamento etrusco-romano, abbiamo testimonianze dell’attività di una sorgente collocata in prossimità del sito (buca della fate, a in figura 6), la quale potrebbe aver contribuito alla deposizione dell’ultimo livello di travertino riconoscibile in cava che, per altro, ha una giacitura orizzontale. naturalmente non abbiamo la possibilità di escludere la concomitante attività della sorgente collocata in corrispondenza dell’attuale mofeta del bossoleto. collegata con la sorgente della buca delle fate vi è una complessa rete di canali di travertino autocostruiti (self-built channel, violante et al., 1994) conseguenti al deflusso delle acque sorgive verso i l fiume ombrone. tali canali raggiungono l’altezza massima di 6 metri e sono riconoscibili per una lunghezza di 150 metri (figs 9b e 9c). lungo alcuni tratti del canale più importante, laddove esso raggiunge la maggiore larghezza ed altezza, sono stati effettuati, probabilmente durante il periodo dell’insediamento di campo muri, alcuni tagli per il reperimento di materiale da costruzione. l’antichità di questa attività estrattiva è confermata dall’alterazione delle pareti tagliate, nonché dalla metodologia con cui sono stati realizzati gli scavi stessi, sostanzialmente effettuati mediante percussione come dimostrano le tracce lasciate in alcuni tratti delle pareti. sulla base dell’età più antica dei travertini di campo muri si può ritenere che l’inizio dell’attività sorgiva della sorgente del bossoleto risalga a 24±3 ka. ne consegue che questa età possa coincidere con quella più antica dei travertini presenti nelle aree circostanti alla sorgente e che corrisponderebbe a quella dei depositi calcarei collocati sul terrazzo fluviale sul quale 113 fig. 7 i depositi alluvionali riconoscibili nella scarpata del terrazzo fluviale sul quale è collocato lo stabilimento termale di s.giovanni sono caratterizzati da alternanze di livelli sabbiosi con ghiaie e strati di calcari incrostanti. a) alternanza di calcari incrostanti e livelli sabbiosi; la freccia indica l’area da cui proviene il dettaglio mostrato in b. b) dettaglio di a. the alluvial deposits exposed in the scarp of the fluvial terrace on which the s.giovanni thermal resorts are located, are characterised by sands and gravels with interbedded encrusting carbonates. a) alternation of encrusting carbonates and sandy layers; the arrow indicates the enlarged area illustrated in detail in b. b) detail of a. fig. 8 fronte occidentale della cava di travertino di campo muri con evidenziate le discordanze angolari e con le età di ciascun episodio deposizionale come ricavato dalle analisi radiometriche 230th/234u realizzate da carrara et al. (1998). western fresh-cut of the campo muri travertine quarry. the angular unconformities and the 230th/234u radiometric ages of the depositional systems (from carrara et al., 1998) are given. i travertini delle terme di s. giovanni ... sono presenti gli attuali stabilimenti termali. tuttavia il loro spessore risulterebbe molto ridotto sugli alti morfologici poiché più vicini all’area sorgiva. lo spessore del travertino che ricopre il terrazzo fluviale, infatti, è stato ricostruito mediante una perforazione recentemente effettuata per la captazione di acque termali (fig. 6), realizzata in prossimità della mofeta. il sondaggio ha attraversato circa 24 metri di travertino chiaro, stratificato, sovrastante una alternanza di livelli travertinososabbiosi di colore grigio e grigio scuro caratterizzati da una importante componente detritica costituita da granuli di quarzo e miche bianche. tale successione è stata perforata fino a 37 metri; al di sotto di questa quota sono state incontrate le argille marine del pliocene medio. 3.1 la dorsale di travertino (travertine fissure-ridge) questo elemento morfo-strutturale (fig. 10) si colloca circa 100 metri a sud dalla mofeta del bossoleto (fig. 6) e si estende per circa 250 metri in direzione ono-ese. la sua edificazione appare essenzialmente legata all’esistenza di sorgenti allineate, caratterizzate da attività intermittente che hanno dato luogo alla deposizione di travertino in una dorsale allungata (fig. 10) che raggiunge localmente la larghezza di circa 40 metri ed un’altezza massima di 10 metri. la fuoriuscita delle acque termali dalla frattura sommitale e dai conetti associati, e lo scorrimento lungo i fianchi della dorsale, ne ha determinato la crescita e lo sviluppo (fig. 11). il suo profilo è asimmetrico: la parte meridionale è più alta, mentre quella settentrionale non supera i 5 metri. essa, infatti, si è sviluppata in corrispondenza di un gradino morfologico che raccorda due superfici orizzontali il cui dislivello è di circa 8 metri (fig. 10). tale gradino morfologico è riconoscibile anche agli estremi della fissure-ridge ed è particolarmente evidente, nelle foto aeree, per circa 300 metri verso la sua prosecuzione orientale. questo gradino morfologico è riferibile alla scarpata di una faglia che avrebbe dislocato il terrazzo fluviale di quota 280 metri e che, in corrispondenza della zona ribassata dalla faglia, raggiunge la quota media di 270 metri. 3.1.1 facies deposizionali lo studio delle facies deposizionali dei travertini delle terme di s.giovanni è stato condotto da diversi autori che hanno concentrato le loro attenzioni soprattutto sulla definizione litologica e geochimica delle facies in formazione e della distribuzione di quelle più antiche presenti nel complesso calcareo di origine termale (guo & riding, 1992, 1994; folk et al., 1985; fouke et al., 2000). nell’insieme, la fissure-ridge è caratterizzata da tre principali morfologie deposizionali: liscia (fig. 11f), microterrazzata (fig. 11g) e macroterrazzata (fig. 11h), corrispondenti a strutture deposizionali riconosciute da guo & riding (1998). i fianchi lisci sono formati dalla sovrapposizione di croste cristalline da bianche a grigie composte da larghi cristalli di calcite che crescono perpendicolari alla superficie deposizionale. i fianchi microterrazzati si caratterizzano per la presenza di piccoli terrazzi disposti fittamente con un piccolo bordo liscio rialzato di alcuni millimetri e che creano micropiscine (rimstone pool, warwick, 1952) larghe alcuni centimetri quadrati. identica strutturazione è presente nei macroterrazzi; la differenza risiede nelle maggiori dimensioni. le porzioni della dorsale dove la deposizione è attiva o inattiva, possono essere riconosciute dalla colorazione dei travertini e dalla colonizzazione delle piante. le aree con recentissima deposizione sono di colore chiaro, talvolta bianco, e caratterizzate dalla totale assenza di piante. questo “deserto bianco” contrasta totalmente con le superfici attive, caratterizzate da colorazioni grigie scure e presenza talvolta massiccia di giunchi ed altre macrofite. la colorazione scura è data dalla presenza di colonie batteriche. cespugli di macrofite, talora associate a muschi ed alghe, riescono ad insediarsi in questo ambiente ostile quando le condizioni chimico-fisiche iniziali (temperatura, gas disciolti, ph…) vengono mitigate dalla diluizione di acque “fredde” o di origine meteorica/fluviale. l’assetto interno della fissure-ridge è osservabile in piccoli saggi di cava presenti nel profilo trasversale 114 fig. 9 a) canale di epoca etrusco-romana (iii sec. a.c. – iv sec. d.c.) riempito da travertino a seguito dell’abbandono dello stabilimento termale e conseguente mancanza di regimazione del flusso delle acque delle sorgenti; b) e c) particolare di canali autocostruiti dovuti al deflusso delle acque emergenti dalla sorgente “buca delle fate” (a in figura 6) che alimentava lo stabilimento termale di epoca etrusco-romana presso campo muri. a) anthropic channel (iii sec. a.c. – iv sec. d.c.) filled by travertine due to the abandon of the thermal resort; b) and c) self built channels developed from the thermal waters running toward the ombrone river from the “buca delle fate” thermal spring (point a in figure 6). this thermal spring fed the campo muri thermal resort during the etruscan-roman period. a. brogi, e. capezzuoli & a. gandin (fig. 11a). esso risulta formato principalmente dalla sovrapposizione di croste cristalline (crystalline crust) parallele alla superficie deposizionale, che formano set di lamine composte da cristalli di calcite disposti a ventagli (ray crystals in chafetz & folk, 1984; folk et al., 1985) o a piuma (feather calcite crystals in guo & riding, 1992). queste lamine si alternano con: livelli formati da strutture a “cespugli” (shrub) composti principalmente da calcite macrocristallina (needle crystal shrub: guo & riding 1994, 1998) talora associati a porzioni micritiche (micrite/spar-rhomb shrub; guo & riding 1994, 1998). l’origine di questa struttura, tipica di ambienti con scarsa energia, viene interpretata sia come organica (chafetz & folk 1984) sia come inorganica (pentecost, 1990). livelli formati dalla sovrapposizione di lamine millimetriche cristalline (paper-thin rafts) che si depositano all’interfaccia acqua/aria di piccole pozze con scarsa energia. quando l’energia è maggiore, le lamine si rompono depositandosi in accumuli sul fondo delle pozze. accumuli lenticolari di pisoidi (pisoids) di differenti misure, densamente impacchettati ed intercalati a livelli micritici. guo & riding (1998) ne riconoscono tre tipi basandosi sulle microstrutture: i) laminati concentricamente e di origine inorganica, anche se con parziali componenti organiche, formati in ambienti turbolenti di alta energia; ii) radial shrub, con delicata struttura dendritica ed associati batteri, cianobatteri e 115 fig. 10 la fissure-ridge di travertino presente presso lo stabilimento termale di s.giovanni. tale struttura è orientata circa ono-ese e mostra un profilo asimmetrico. lungo la sommità è presente una frattura la cui larghezza varia da 17cm a qualche millimetro. the travertine fissure-ridge located close to the s.giovanni thermal resort. this structure, ese striking, shows an asymmetrical profile. on the top of the fissure-ridge, a fissure ranging from 0,1 to 17 cm , is located. i travertini delle terme di s. giovanni ... 116 fig. 11 particolari del travertino che costituisce la fissure-ridge delle terme di s.giovanni; a1) lungo la sommità della dorsale sono presenti alcune cavette che mettono in evidenza la struttura interna della dorsale; a2) particolare di a1; b) la fessura che attraversa tutta la dorsale è massima in corrispondenza della sua zona mediana, dove raggiunge 17 cm; c) in corrispondenza degli estremi, invece, la fessura è larga al massimo qualche millimetro; d1) agli estremi sono presenti coni dai quali fuoriesce acqua ad intervalli oppure dove gorgoglia anidride carbonica; d2) alcune volte i coni sono fessurati e (d3) la fessura li divide a metà per tutta la lunghezza della dorsale (d4); e) in corrispondenza dell’estremità occidentale della dorsale la fessura che attraversa la sommità dell’intera struttura ha dislocato un manufatto collocato sulla dorsale a circa metà degli anni 50, testimoniando una recentissima fessurazione del travertino. f) in alcuni tratti il travertino che costituisce la dorsale è liscio (f), mentre altre volte è microterrazzato (g1 e g2) o macroterrazzato (h1, h2); i terrazzi di ordine maggiore possono raggiungere il metro di diametro e dar luogo a piccole vasche sospese, riempite d’acqua (h3). travertine features of the s.giovanni fissure-ridge: a1) small quarries located along the fissure-ridge highlight the internal architecture of the ridge.; a2) particular of a1; b) the width of the fissure at the top of the ridge is maximum (17 cm) in the middle part of the fissureridge; c) the fissure located at the top of the fissure-ridge is about 1-2 mm wide at the extremities of the fissure-ridge; d1) at the extremities of the fissure-ridge cones from which thermal water and carbon dioxide rise up, are located; d2) cones can be fissured and (d3) the fissure divides into two halves the cones along the fissure-ridge (d4); e) in the western extremity of the fissure-ridge, a man-made feature located at the top of the ridge during 50s has been widely fissured; f) the travertine of the fissure-ridge can be smooth (f), microterraced (g1 e g2) o macroterraced (h1, h2); the macroterraces can reach one metre and can give rise to pools containing thermal water (h3). a. brogi, e. capezzuoli & a. gandin diatomiti, formati in pools saltuariamente agitate; iii) mammellonati, stromatolitici con concrescimenti irregolari, spesso coperti da filamenti cianobatteriali di ambienti a bassa energia. livelli con cavità sferiche o circolari, di varia misura, aperte o chiuse corrispondenti a bolle di gas ricoperte da calcite (coated bubble) secondo un meccanismo illustrato da chafetz et al., 1991. il gas probabilmente deriva principalmente da attività microbica dei sedimenti sottostanti (guo & riding, 1998) o per locale turbolenza delle acque. strutture isolate (mounds) costituite da rilievi formati dalla concentrazione di steli incrostati (manicotti calcarei cristallini di giunchi (reed) in posizione di vita. si formano principalmente in ambienti palustri (pozze o laghetti distali) dove le acque termali raffreddate o diluite da altre acque di origine fluvio-meteorica permettono la colonizzazione delle piante superiori. l’elevata presenza di queste piante costituisce una barriera al fluire dell’acqua e determina variazioni morfologiche del sistema. accumuli lenticolari di granuli carbonati (lithoclast travertine) derivanti dalla rielaborazione penecontemporanea delle altre macrofacies calcaree. possono contenere anche frammenti di vegetali incrostati e localmente gasteropodi, ostracodi (skeletal grains), ossa di vertebrati e materiale extrabacinale apportato dal vento, da corsi d’acqua ecc. livelli continui, talvolta ben sviluppati, di silt argillosi ocra scuri o rossi (paleosols). questi si formano in corrispondenza di superfici in erosione durante periodi di prolungata inattività del sistema deposizionale/ sorgivo. 4. il controllo strutturale della circolazione idrotermale i depositi di travertino e le sorgenti termali di s.giovanni terme mostrano alcune caratteristiche peculiari che li differenziano dagli altri depositi di travertino e dalle sorgenti presenti nell’area di rapolano terme. infatti, mentre la circolazione idrotermale che caratterizza l’area di rapolano è più o meno concentrata lungo la faglia di rapolano, dove quest’ultima è stata dislocata dalle faglie più recenti, le emergenze termali di s.giovanni si collocano a circa 2 km dalla suddetta struttura. inoltre, le caratteristiche chimiche delle acque che oggi fuoriescono nell’area di s.giovanni suggeriscono un loro percorso di circolazione e risalita diverso da quello delle acque che emergono in corrispondenza delle altre sorgenti termali (minissale et al., 2002b). in particolare, i rapporti isotopici dell’elio (3he/4he), così come quelli del carbonio (13c/12c) indicano a s. giovanni la presenza di gas provenienti da zone profonde della crosta, probabilmente originati da processi metamorfici e/o magmatici, che si sono mescolati con fluidi e gas provenienti da livelli strutturali più superficiali (minissale et al. 2002b cum bibl.). lo studio geologico condotto nell’area ha permesso di individuare l’esistenza di alcune faglie dirette che hanno giocato un ruolo fondamentale per la circolazione idrotermale negli ultimi 25 ka e per la loro risalita verso la superficie. per quanto l’attività di queste faglie sia molto recente, esse sono di difficile individuazione a causa di due principali fattori: a) le loro tracce in superficie sono state largamente ricoperte dal travertino che si è depositato dalle sorgenti; b) l’attività antropica ha modellato il paesaggio soprattutto a causa delle intense coltivazioni. tuttavia la loro presenza è convalidata da alcuni indizi, quali l’allineamento di sorgenti attive e non, la dislocazione di corpi geologici più antichi dei travertini ed infine l’esposizione di alcune strutture minori (faglie e fratture) associate alla faglia principale. l’analisi integrata di tali elementi ha permesso di ricostruire la geometria e la cinematica delle faglie che costituiscono il sistema principale delle strutture responsabili del termalismo e della deposizione del travertino nell’area di s. giovanni terme. poche centinaia di metri a nord-ovest dell’area di campo muri è presente un deposito di travertino che costituisce un elemento morfologico positivo a sezione circolare, di circa 150 metri di diametro, che si eleva circa 25 metri rispetto alle aree circostanti (punto b in figura 6). il travertino che costituisce tale rilievo è ben stratificato ed è disposto con simmetria centrifuga rispetto alla parte sommitale, suggerendo che esso è stato depositato da acque che defluivano da una sorgente posta nella zona apicale del rilievo verso le aree morfologicamente più depresse. questa sorgente e quella della buca delle fate (punto a in figura 6) sono allineate parallelamente alla fissure-ridge di travertino presente presso lo stabilimento termale di s.giovanni. verso est, i punti (a) e (b) si allineano con un’altra sorgente, anch’essa non più attiva, che è stata responsabile dello sviluppo di un deposito di travertino poco esteso arealmente, spesso fino a 10 metri (punto c in figura 6). tale deposito di travertino è adiacente alla traccia della faglia di rapolano che in questo tratto è sepolta da una spessa coltre di detrito. queste evidenze indicano, con buona probabilità, l’esistenza di una faglia di età pleistocenica, orientata in direzione onoese, la cui attività ha permesso una importante circolazione idrotermale lungo alcuni suoi tratti e all’intersezione con la faglia di rapolano, come documentato anche per altre faglie collocate più a sud presso serre di rapolano (brogi, 2004). l’esistenza di questa faglia è inoltre dimostrata dalla evidente dislocazione della superficie di contatto tra i depositi limoso-argillosi di ambiente pelagico e le sovrastanti sabbie costiere del pliocene medio. tale contatto, infatti, la cui giacitura è pressoché sempre orizzontale, affiora alla quota di 275 metri s.l.m. nel blocco ribassato dalla faglia (punto 1 in figura 12), mentre nell’altro blocco affiora alla quota di 325 metri s.l.m (punto 2 in figura 12). questo permette di ipotizzare che il blocco ribassato coincida con la parte settentrionale dell’area di campo muri. allo stesso modo è possibile stimare il rigetto verticale minimo di tale struttura che, sulla base delle differenze di quota del contatto tra argille e sabbie plioceniche, risulta essere di circa 50 metri. informazioni più precise sulla cinematica di questa faglia sono state ricavate laddove questa struttura interseca la faglia di rapolano ed interessa la successione giurassica della falda toscana (punto a in figura 12). qui essa è costituita da una zona di deformazione piuttosto ampia, definita da numerose faglie dirette a rigetto metrico alle quali sono collegate numerose fratture ed evidenti fenomeni di idrotermalizzazione. in figura 13 sono riportati alcuni particolari delle faglie minori studiate e la loro analisi cinematica: 117i travertini delle terme di s. giovanni ... 118 f ig . 1 2 c a rt a g eo lo g ic a d el l’a re a d e lle t e rm e d i s . g io va nn i. il p u n to a i n d ic a l’a re a ov e è st at a re al iz za ta l ’a na lis i ci n em at ic a n el le fa g li e m in o ri a s s o c ia te a l si st em a d i fa g lie d ire tt e ch e at tr ave rs an o l ’a re a d i st ud io . i p un ti 1 e 2 s o n o d is c u ss i ne l t es to . g e o lo g ic al m ap o f th e t e rm e s .g io va n n i ar ea . t h e p o in t a , in d ic at es t he a re a w h e re t h e k in e m at ic s an al ys is o f th e m in o r fa u lt s a n d fr a c tu re s re la te d to th e s .g io va n n i fa u lt sy st e m s h a s b ee n p er fo rm ed . p o in ts 1 a n d 2 ar e d is cu ss ed i n th e te xt . a. brogi, e. capezzuoli & a. gandin sono riportati i diagrammi stereografici delle faglie e delle fratture e sono messi in evidenza quelle fratture lungo le quali vi è stata circolazione dei fluidi idrotermali collegati con la deposizione del travertino. tali fratture, infatti, sono caratterizzate da vistosi fenomeni di ossido-riduzione del ferro. i processi chimico-fisici che favoriscono questo processo sono legati alla circolazione di fluidi contenenti composti chimici extra-formazionali quali, per esempio, idrocarburi, acidi organici, metano ed idrogeno solforato. di questi, l’ultimo è quello che caratterizza tutte le acque termali dell’area di rapolano (minissale et al., 2002b). i l diverso chimismo delle acque termali di s.giovanni terme ed il conseguente percorso di circolazione e risalita, può trovare una spiegazione nell’assetto tettonico dell’area, come già descritto da costantini et al. (1982) e da brogi et al. (2002). e’ noto infatti che l’importante piega rovesciata che ha deformato la falda toscana e che affiora lungo la dorsale monti del chianti-monte cetona dalla zona di montalceto (a sud di serre di rapolano) fino al monte cetona (passerini, 1964; lazzarotto, 1973) risulta dislocata dalla faglia di rapolano immediatamente a sud di serre di rapolano (brogi et al, 2002). nell’area di s.giovanni, quindi, tale struttura rimane sepolta al di sotto dei depositi neogenico-quaternari del bacino di siena. tale piega risulta sradicata al livello della successione evaporitica del trias (formazione anidritica di burano) ed è sovrascorsa sui termini più recenti (macigno) della falda toscana, costituente il blocco di muro. questo assetto strutturale, già ipotizzato da costantini et al. (1982), ha trovato conferma negli studi di brogi et al. (2002) e negli ultimi rilevamenti geologici realizzati a sud di serre di rapolano nell’ambito della nuova cartografia geologica della regione toscana alla scala 1:10000 (f. 309010). tale assetto risulta di estrema importanza alla luce del fatto che l’anticlinale in parola potrebbe trovarsi proprio sepolta sotto l’area di s.giovanni, come illustrato nella figura 14. tale elemento costituirebbe una struttura positiva caratterizzata da carbonati fratturati ed evaporiti che vanno a costituire un serbatoio alimentato, almeno in parte, da fluidi di origine profonda. la loro circolazione risente fortemente del controllo strutturale conseguente alla presenza di un livello cataclastico che coincide con la zona di detachment della piega. tali fluidi, quindi, avrebbero una provenienza diversa rispetto a quelli che risalgono lungo la faglia di rapolano e che, al contrario, circolano in livelli strutturali più superficiali. naturalmente per le acque che risalgono nell’area di s.giovanni non possono essere esclusi fenomeni di mixing con le acque meteoriche e con quelle che circolano al contatto con la copertura impermeabile rappresentata dalla argille del pliocene (fig. 14), come confermato dai dati geochimici di minissale et al. (2002a). fig. 13 analisi strutturale del sistema di faglie dirette minori associate alla faglia lungo la quale si collocano tre sorgenti termali non più attive, tra cui quella della buca delle fate che alimentava lo stabilimento termale di epoca etrusco-romana presso campo muri. le rocce dislocate sono le radiolariti giurassiche della formazione dei diaspri. lungo le zone di faglia sono presenti numerosissime fratture sub-verticali o molto inclinate che hanno costituito i condotti di risalita dei fluidi idrotermali, come testimoniato dalla mineralizzazione presente lungo le zone fratturate. i diagrammi stereografici (diagramma di schmidt, emisfero inferiore) indicano: 1) ciclografiche, poli e pitch delle strie riconosciute lungo i piani di faglia; 2) contouring dei dati riportati in 1; 3) fratture presenti nel tetto delle faglie con traccia di mineralizzazione; 4) contouring di 3. structural analysis of the minor normal faults related to the main fault along which the three inactive thermal springs are aligned. the dissected rocks consist of the jurassic radiolarites belonging to the diaspri fm. the fault zone is characterised by numerous sub-vertical fractures along which idrothermal fluids circulated, as attested by the mineralization occurring along some fractures. the stereographic diagrams (schmidt diagram, lower hemisphere) indicate: 1) cyclographic traces, poles and pitch of the mechanical striae along the fault planes; 2) contouring of data given in 1; 3) cyclographic traces of the mineralised fractures occurring in the hangingwall of the normal faults; 4) contouring of the data given in 3. i travertini delle terme di s. giovanni ... 119 120 fig. 14 sezione geologica schematica, non in scala, orientata circa ovest-est che mostra la relazione tra l’assetto tettonico dell’area delle terme di s. giovanni e la circolazione dei fluidi idrotermali. mentre i fluidi che risalgono lungo la zona di danneggiamento della faglia di rapolano hanno un percorso di circolazione piuttosto superficiale, quelli che risalgono alle terme di s.giovanni sono guidati da elementi strutturali diversi. dal serbatoio costituito essenzialmente dal nucleo dell’anticlinale rovesciata del monte cetona (dislocata dalla faglia di rapolano in questo settore) i fluidi raggiungono la superficie attraverso le fratture collegate con la zona di danneggiamento del sistema di faglie a cui appartiene quella lungo la quale si è sviluppata la fissure-ridge. tali faglie sono circa parallele alla sezione geologica e quindi non riportate nello schema. si veda il testo per la discussione. schematic, not to scale, geological cross-section, w-e oriented, showing the relationships between the tectonic setting of the terme s.giovanni area and the hydrothermal fluid circulation. the fluids arising along the damaged zone of the rapolano fault follow a shallow pathway; in contrast, the hydrothermal fluids flowing from the terme s.giovanni thermal springs circulate at deepest levels. they are stocked within the nucleus of the mt. cetona anticline (dissected by the rapolano fault in this zone) which give rise to a reservoir due to the highly fractured carbonate rocks. the fluids can escape toward the surface through vertical fractures related to the damaged zone of a fault system to which the normal fault giving rise to the travertine fissure-ridge belongs. all these faults are about parallel to the geological section and thus they cannot be reported. see the text for discussion. fig. 15 schema che mostra come la fissure-ridge delle terme di s.giovanni si sia sviluppata lungo la traccia di una faglia di età molto recente, probabilmente ancora attiva, che ha dislocato i depositi di un terrazzo fluviale collegato con l’evoluzione idrografica del fiume ombrone. cartoon showing the relationships between the travertine fissure-ridge and the normal fault, probably active, dissecting the alluvial deposits of a fluvial terrace developed together with the hydrographic evolution of the ombrone river. a. brogi, e. capezzuoli & a. gandin 4. discussione e conclusioni l’evoluzione deposizionale del travertino nell’area delle terme di s.giovanni testimonia un’attività idrotermale prolungata nel tempo, iniziata circa 24±3 ka e caratterizzata da periodi di attività alternati a momenti di stasi. per il significato tettonico che le manifestazioni idrotermali rivestono, è quindi possibile ritenere che l’area in studio sia stata caratterizzata da una attività tettonica intermittente dal pleistocene superiore all’olocene. in particolare, sulla base delle caratteristiche morfo-strutturali e dell’attività idrotermale collegata alla travertine fissure-ridge è possibile ipotizzare l’esistenza di attività tettonica probabilmente tuttora in atto. la fissure-ridge, infatti, si è sviluppata lungo la traccia di una faglia presumibilmente con cinematica normale che ha dislocato un terrazzo fluviale di età pleistocenica, nonché i depositi di travertino collegati con l’attività della sorgente del bossoleto, la cui età più antica è riferibile con buona probabilità a 24±3 ka (fig. 15). la faglia lungo la quale si è sviluppata la fissure-ridge ha una età necessariamente più recente di 24±3 ka, poiché disloca i travertini collegati con l’attività della sorgente del bossoleto. la circolazione di fluidi, ancora attiva in corrispondenza di tale struttura, conferma che la zona di fratturazione collegata al movimento della faglia è ancora permeabile, implicando l’esistenza di fratture beanti a sostegno dell’attività molto recente della struttura considerando anche l’elevato potere incrostante di queste acque molto saline (minissale et al., 2002b). l’attività molto recente della faglia troverebbe inoltre conferma nella dislocazione dei travertini che si sono depositati nel marzo 2003 in corrispondenza del margine orientale della fissure-ridge ed interessati da una fessurazione che fino a novembre 2005 ha raggiunto localmente i 2 mm (fig. 16). sulla base di questi dati è possibile determinare il tasso di dilatazione degli ultimi 2,5 anni che risulta pari a circa 0,16 mm/anno. tuttavia analoghe valutazioni possono essere fatte prendendo in considerazione un manufatto che è stato collocato circa nella metà del secolo scorso sulla sommità della fissureridge. tale manufatto coincide con il bocca-pozzo di un sondaggio poco profondo dal quale veniva captata acqua termale, che oggi risulta vistosamente dislocato (fig. 11e). la dilatazione massima è di 1,1 cm implicando un tasso medio di dislocazione orizzontale pari a circa 0,02 mm/anno, considerando un movimento costante nel tempo. la dislocazione orizzontale della fessura che attraversa interamente la sommità della fissure-ridge, è apparentemente in contraddizione con la natura di faglia diretta della struttura dalla quale la fissure-ridge ha avuto origine. essa, infatti, sulla base della differente quota del terrazzo dislocato, ha prodotto un rigetto verticale di circa 8 metri in almeno 24 ka, considerando l’età più antica dei travertini dislocati dalla faglia. sulla base di questa considerazione è possibile ricavare il tasso, sia pure indicativo, di rigetto verticale della faglia, che risulterebbe pari a 0,33 mm/anno. questo dato, tuttavia, è da considerarsi il valore minimo della faglia, per il fatto che per il calcolo è stata utilizzata l’età più antica dei travertini dislocati 121 fig. 16 il travertino che si è depositato nel marzo del 2003 in corrispondenza delle due estremità della dorsale è stato interessato da fratturazione lungo la direzione della fessura principale che attraversa per intero tutta la struttura. i numeri 1, 2, 3 e 4 indicano gli stessi coni fotografati nel marzo 2003 (a sinistra) e nel novembre del 2005 (a destra) mostrando come il travertino depositato nel 2003 sia già stato attraversato da una fessura larga qualche millimetro. the travertine deposited in march 2003 at the extremities of the travertine fissure-ridge has been broadly fissured. the numbers 1, 2, 3 and 4 indicate the same cones photographed at different times (march 2003, to the left and november 2005, to the right), highlighting how the new travertine has been fissured for some millimetres in 2.5 years. i travertini delle terme di s. giovanni ... dalla faglia. d’altra parte il movimento dilatante lungo la traccia della faglia, testimoniato con certezza almeno per gli ultimi 50 anni, inducono ad ipotizzare che nell’ultimo periodo la faglia potrebbe essere stata sottoposta ad un accumulo di tensioni che hanno prodotto soltanto una dilatazione orizzontale, ma che potrebbero preannunciare l’imminente riattivazione della faglia. naturalmente la faglia potrebbe essere caratterizzata da un comportamento asismico che tuttavia, ad oggi, non siamo in grado di dimostrare. nell’insieme, comunque, le relazioni esistenti tra l’attività idrotermale e la deposizione di travertino costituiscono un buon esempio di correlazione tra travertini ed elementi strutturali che rappresentano l’espressione superficiale di tensioni accumulatisi nella crosta superiore a seguito di sollecitazioni tettoniche. ne deriva un quadro geologico piuttosto chiaro con importanti implicazioni di carattere neotettonico, che mette in evidenza strutture attive e potenzialmente sismogenetiche. per questo motivo, è nostro parere la necessità di un monitoraggio finalizzato al controllo dei movimenti lungo la faglia delle terme di s.giovanni mediante l’applicazione di sensori che possano analizzare il progressivo movimento nel tempo attraverso la fissure-ridge, ottimo indicatore tettonico. ringraziamenti gli autori ringraziano a. costantini e a. lazzarotto per gli innumerevoli scambi di opinione in merito allo sviluppo della fissure-ridge ed alla deposizione dei travertini nell’area di s. giovanni; gli autori ringraziano, inoltre, c. carrara per la discussione scientifica sui travertini di campo muri. si ringraziano inoltre due revisori anonimi per i consigli ed i suggerimenti utili a migliorare la versione originale del manoscritto. questo lavoro è stato eseguito con i finanziamenti dell’università di siena (par 2005, coordinatore scientifico a. lazzarotto) e della regione toscana – servizio geologico regionale (progetto cartografia geologica della regione toscana, scala 1:10.000). lavori citati acocella v., pascucci v. & dominici g. (2002) basin deformation due to laccolith emplacement at radicofani (southern tuscany, italy). boll. soc. geol. it., volume speciale, 1, pp. 749-756. altunel e. (2005) travertines: neotectonic indicators. in: ozkul, m., yagiz, s. and jones, b. (eds.): proceedings of 1st international symposium on travertine, september 21-25, 2005, denizliturkey, pp. 105-106, kozan ofset, ankara. altunel e. & hancock p.l. (1993a) morphology and structural setting of quaternary travertines at pamukkale, turkey. geological journal, 28. pp. 335-346. altunel e. & hancock p.l. (1993b) active fissuring and faulting in quaternary travertines at pamukkale, western turkey. z.geomorph.n.f., 94, pp. 285302. andrews j. & riding r. (2001) depositional facies and acqueous-solid geochemestry of travertine-depositing hot spring (angel terrace, mammoth hot springs, yellowstone national park, u.s.a.): discussion. journal of sedimentary research, 71, 496-497. atabey e. (2002) the formation of fissure ridge type laminated travertine-tufa deposits microscopical characteristics and diagenesis, kirşehir, central anatolia. bullettin of the mineral research and exploration, 123-124, pp. 59-65. baldi p., bertini g., cameli g.m., decandia f.a., dini i., lazzarotto a. & liotta d. (1994) tettonica distensiva post-collisionale nell'area geotermica di larderello (toscana meridionale). studi geologici camerti. vol. spec. 1, pp. 183-193. barazzuoli p., izzo s., menicori p., micheluccini m. & salleolini m. (1991) un esempio di acquifero superficiale al imentato da acqua termale (rapolano terme, siena). boll. soc. geol. it., 110, pp. 3-14. bertini g., cameli g.m., costantini a., decandia f.a., di filippo m., dini i., elter f.m., lazzarotto a., liotta d., pandeli e., sandrelli f. & toro b. (1991) struttura geologica fra i monti di campiglia e rapolano terme (toscana meridionale): stato attuale delle conoscenze e problematiche. studi geologici camerti, vol. spec.1 (1991), pp. 155178. bonini m. & sani f. (2002) extension and compression in the northern apennines (italy) hinterland: evidence from the late miocene-pliocene sienaradicofani basin and relations with basement structures. tectonics, 21(3), pp. 135. brogi a. (2002) relazione tra strutture distensive neogenico-quaternarie ed i depositi di travertino nell’area di rapolano terme (appennino settentrionale). atti tic. sc. terra, 43, pp. 41-54. brogi a. (2004) faults linkage, damage rocks and hydrothermal fluid circulation: tectonic interpretation of the rapolano terme travertines (southern tuscany, italy) in the context of northern apennines neogene-quaternary extension. eclogae geologicae helvetiae, 97, pp. 307-320. brogi a. (2006) neogene extension in the northern apennines (italy): insights from the southern part of the mt. amiata geothermal area. geodinamica acta, 19, pp. 33-50. brogi a., capezzuoli e., costantini a., gandin a. & lazzarotto a. (2005a) tectonics and travertine relationships in the rapolano terme area (northern apennines, italy). proceedings of 1st international symposium on travertine. september 21-25, 2005, denizli turkey, pp. 142-148, kozan offset, ankara. brogi a., costantini a. & lazzarotto a. (1999) carta geologica dell’area di rapolano terme. s.el.ca firenze. brogi a., costantini a. & lazzarotto a. (2002) structural setting of the rapolano-trequanda ridge (southern tuscany, italy). boll. soc. geol. it., vol. spec. 1, pp. 757-767. brogi a., ghinassi m., aldinucci m., bambini a.m., foresi l.m. (2005c) new constraints for age determination of the pliocene normal faults affecting the rapolano-trequanda ridge (southern tuscany). 122 a. brogi, e. capezzuoli & a. gandin rend. soc. geol. it., 1, 34-36. brogi a., lazzarotto a., liotta d. & crop-18 working group (2005b) structural features of southern tuscany and geological interpretation of the crop 18 seismic reflection survey (italy). boll. soc. geol. it., 3, pp. 213-236. brogi a. & liotta d. (2006) understanding the crustal structures of southern tuscany: the contribution of the crop18 project. bollettino di geofisica teorica e applicata, 47, pp. 401-424. bruhn r.l., yonkee w.a. & parry w.t. (1990) structural and fluid-chemical properties of seismogenic normal faults: tectonophysics, 175, pp. 139–157. çakir z. (1999) along-strike discontinuity of active normal faults and its influence on quaternary travertine deposition: examples from western turkey. turkish journal of earth sciences, 8, pp. 67-80. carrara c., ciuffarella l. & paganin g. (1998) inquadramento geomorfologico e climaticoambientale dei travertini di rapolano terme (si). il quaternario, 11, pp. 319-329. chafetz h.s. & folk r.l. (1984) travertines: depositional morphology and the bacterially constructed constituents. j. sedim. petrol., 54, pp. 289-316. chafetz, h.s., rush, p.f. & utech, n.m. (1991) microenvironmental controls on mineralogy and habit of caco3 precipitates: an example from an active travertine system: sedimentology, 38, pp. 107-126. cipriani n., ercoli a., malesani p. & vannucci s. (1972) i travertini di rapolano terme (siena). mem. soc. geol. it., 11, pp. 31-46. collettini c., de paola n., holdsworth r.e. & barchi m. (2006) the development and behaviour of low-angle normal faults during cenozoic asymmetric extension in the northern apennines, italy. journal of structural geology, 28, pp. 333-352. costantini a., lazzarotto a. & sandrelli f. (1982) conoscenze geologico strutturali. in: il graben di siena. cnr-pfe-rf 9, pp. 11-32. curewitz d. & karson j.a. (1997) structural settings of hydrothermal outflow: fracture permeability maintained by fault propagation and interaction. journ. volcan. and geother. res., 79, pp. 149-168. dallmeyer r.d. & liotta d. (1998) extension, uplift of rocks and cooling ages in thinned crustal provinces: the larderello geothermal area ( inner northern apennines, italy). geol. mag., 135, pp. 193-202. du j., liu c., fu b., ninomiya y., zhang y., wang c., wang h. & sun z. (2005) variations of geothermometry and chemical-isotopic compositions of hot spring fluids in the rehai geothermal field, southwestern china. journal of volcanology and geothermal research, 142, pp.243– 261. finetti i.r., boccaletti m., bonini m., del ben a., geletti r., pipan m. & sani f. (2001) crustal section based on crop seismic data across the north tyrrhenian–northern apennines–adriatic sea. tectonophysics, 343, pp. 135-163. folk r., chafetz h.s. & tiezzi p.a. (1985) bizarre forms of depositional and diagenetic calcite in hot-spring travertines, central italy. in schneidermann n. & harris p. (eds): the biology of bluegreen algae. oxford, blackwell scientif ic publication, pp. 434-472. fouke b.w., farmer j.d., des marais d.j., pratt l., sturchio n.c., burns p.c. & discipulo m.k. (2000) depositional facies and acqueous-solid geochemestry of travertine-depositing hot spring (angel terrace, mammoth hot spring, yellostone national park, u.s.a.). journal of sedimentary research, 70(3), pp. 565-585. fouke b.w. (2001) reply depositional facies and acqueou-solid gechemestry of travertine-depositing hot spring (angel terrace, mammoth hot springs, yellowstone national park, u.s.a.). journal of sedimentary research, 71, 496-497. guo l. & riding r. (1992) micritic aragonite laminae in hot water travertine crust, rapolano terme. sedimentology, 39, pp. 1067-1079. guo l. & riding r. (1994) origin and diagenesis of quaternary travertine shrub facies, rapolano terme, central italy. sedimentology, 41, pp. 499520. guo l. & riding r. (1998) hot-spring travertine facies and sequences, late pleistocene, rapolano terme, italy. sedimentology, 45, pp. 163-180. guo l. & riding r. (1999) rapid facies change in holocene fissure ridge hot spring travertines, rapolano terme, italy. sedimentology, 46, pp. 1145-1158. hancock p.l., chalmers r.m.l., altunel e. & çakir z. (1999) travitonics: using travertines in active fault studies. journ. struct. geol., 21, pp. 903916. janssen a., swennen r., podoor n. & keppens e. (1999) biological and diagenetic influence in recent and fossil tufa deposits from belgium. sedimentary geology, 126, pp. 75–95. kharaka y.k., sorey m.l. & thordsen j.j. (2000) large-scale hydrothermal fluid discharges in the norris–mammoth corridor, yellowstone national park, usa. journal of geochemical exploration, 69–70, pp. 201–205. lazzarotto a. (1973) caratteri strutturali dei nuclei mesozoici di montalceto, trequanda e piazza di siena (prov. di siena). atti soc. tosc. sc. nat., mem., serie a, 79, pp. 251-266. lecchini f. & mazzini d. (1986) rapolano ed il suo territorio, vol. 2, al.sa.ba. 1986, pp. 236. liotta d. (1994) structural features of the radicofani basin along the piancastagnaio (mt. amiata) – s.casciano dei bagni (mt. cetona) cross section mem. soc. geol. it., 48, pp. 401-408. liotta d. (1996) analisi del settore centro-meridionale del bacino pliocenico di radicofani (toscana meridionale) boll. soc. geol. it., 115, pp. 115143. liotta d. & salvatorini g. (1994) evoluzione sedimentaria e tettonica della parte centro-meridionale del bacino pliocenico di radicofani studi geologici cemerti, vol. spec. 1994/1, pp. 65-77. livnat a. & kronfeld j. (1985) paleoclimatic implications of u-series dates for lake sediments and travertines in the arava rift valley, israel quaternary research, 24, pp. 164-172. 123i travertini delle terme di s. giovanni ... losacco u. (1952) la struttura del territorio di rapolano e lucignano (siena e arezzo) boll. soc. geol. it., 70(2), pp. 402-434. losacco u. & del giudice d. (1958) stratigrafia e tettonica degli affioramenti mesozoici posti fra le colline di rapolano ed il monte cetona (siena) boll. soc. geol. it., 77, pp. 1-32. mantovani e., albarello d., tamburelli c. & babbucci d. (1995) evolution of the tyrrhenian basin and surrounding regions as a result of the africaeurasia convergence journal geodinamics, 21, pp. 35-72. mantovani e., albarello d., tamburelli c. & babbucci d. (1997) recent/present tectonic processe in the italian region and their relation with seismic and volcanic activity. ann. tect., xi, 27-57. martìn-algarra a., martìn-martìna m., andreoc b., julià r. & gonzàlez-gòmez c. (2003) sedimentary patterns in perched spring travertines near granada (spain) as indicators of the paleohydrological and paleoclimatological evolution of a karst massif sedimentary geology, 161, pp. 217–228. martini i.p. & sagri m. (1993) tectono-sedimentary characteristics of late miocene-quaternary extensional basins of the northern apennines earth sciences rewiews, 34, pp. 197-233. minissale a., kerrick d.m., magro g., murrell m.t., paladini m., rihs s., sturchio n.c., tassi f. & vaselli o. (2002b) geochemistry of quaternary travertines in the region north of rome (italy): structural, hydrologic and paleoclimatic implications earth and planetary science letters, 203, pp. 709-728. minissale a., magro g., martinelli g., vaselli o. & tassi g.f. (2000) fluid geochemical transect in the northern apennines (central-northern italy): fluid genesis and migration and tectonic implications tectonophysics, 319, pp. 199–222. minissale a., vaselli o., tassi f., magro g. & grechi g.p. (2002a) fluid mixing in carbonate aquifers near rapolano (central italy): chemical and isotopic constraints applied geochemistry, 17, pp. 1329–1342. pascucci v., costantini a., martini ip. & dringoli r. (2005) tectono-sedimentary analysis of a complex, extensional, neogene basin formed on thrust-faulted, northern apennines hinterland: radicofani basin, italy. sed. geol., 183, 71-97. passerini p. (1964) il monte cetona (provincia di siena) boll. soc. geol. it., 83, pp. 219-238. pentecost a. (1990) the formation of travertine shrubs: mammoth hot springs, wyoming geological magazine, 127(2), pp. 159-168. van gardingen p.r., grace j., jeffree c.e., byari s.h., miglietta f., raschi a. & bettarini i. (1997) longterm effects of enhanced co2 concentrations of leaf gas exchange: research opportunities using co2 springs in raschi a., miglietta f., tognetti r., van gardingen p.r. (eds), plant responses to elevated co2 evidence from natural springs. cambridge university press. 272 pp. violante c., ferreri v., d’argenio b. & golubic s. (1994) quaternary travertines at rocchetta a volturno (isernia, central italy). facies analysis and sedimentary model of an organogenic carbonate system i.a.s. 15th reg. meet., april, 1994, ischia, guide book to the field trip, pp. 3-23. viti m., mantovani e., babbucci d. & tamburelli c (2006) quaternary geodynamics and deformation pattern in the southern apennines: implications for seismic activity boll. soc. geol. it., 125, pp. 273291. warwick g.t. (1952) rimstone pools and associated phenomena trans. cave. res. group. gb., 2, pp. 153-165. 124 ms. ricevuto il 5 giugno 2007 testo definitivo ricevuto il 24 luglio 2007 ms. received: june 5, 2007 final text received: july 24, 2007 a. brogi, e. capezzuoli & a. gandin large mammals from the middle pleistocene (mis 11) site of fontignano 2 (rome, central italy), with an overview of “san cosimato” assemblages. alessio iannucci 1, beniamino mecozzi 1, raffaele sardella 1 1 dipartimento di scienze della terra, paleofactory, sapienza università di roma, roma, italy corresponding author: b. mecozzi <beniamino.mecozzi@uniroma1.it> abstract: here we describe fossil mammal remains recovered from the late middle pleistocene (mis 11) of fontignano 2 (rome, central italy). two species are recognized: the aurochs bos primigenius and the red deer cervus elaphus. the presence of b. primigenius represents one of the earliest diagnostic evidence of the species. conversely, remains of c. elaphus are not fully diagnostic at a subspecies level, despite being long considered among the reference occurrences of c. e. eostephanoceros in italy. this reconsideration, concurrent with the revised chronology of several localities of the area of rome, questions the validity of the chronosubspecific and evolutionary repartition of the red deer as often envisioned in the literature, i.e., c. e. acoronatus, c. e. eostephanoceros, c. e. rianensis, c. e. elaphus. remains of fontignano 2 are part of those recovered within the san cosimato formation, also including via di brava (mis 13 or mis 11), with palaeoloxodon antiquus, and san cosimato (mis 11), with stephanorhinus sp., b. primigenius, castor fiber, and emys orbicularis. keywords: fossil vertebrate, biochronology, galerian, quaternary, italian peninsula. available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 34 (1), 2021, 155-164 1. introduction the area of ponte galeria (rome, fig. 1), along the tyrrhenian coast in central italy, has yielded an exceptional amount of fossil remains recovered from geochronologically calibrated deposits, providing a unique source of knowledge on middle pleistocene terrestrial ecosystems of europe. indeed, the progressive uplift of the area led to continental depositional conditions since about 0.8 ma, in coincidence with the start of the activity of the roman magmatic province (conticelli & peccerillo, 1992; de rita et al., 1993; karner et al., 2001). as a result, volcanic products are intercalated within the fluvial and lacustrine sedimentary successions deposited from this point onwards, providing radiometric age constraints for the correlation of the several fossiliferous localities that are here represented (ambrosetti, 1965; ambrosetti & bonadonna, 1967; ambrosetti et al., 1972; caloi & palombo, 1978, 1979b, 1986; kotsakis et al., 1992; di stefano et al., 1998; petronio & sardella, 1999; milli et al., 2008; palombo & milli, 2011; sardella & petrucci, 2012; marra et al., 2014; sardella et al., 2015). the seminal work of conato et al. (1980) recognized five informal lithostratigraphic units in the area, extending from the late early pleistocene to the late middle pleistocene: monte mario, ponte galeria, s. cosimato, aurelia, and vitinia formations. subsequent studies have improved this scheme and further developed its calibration with the marine isotopic scale (mis), in turn resulting in a refined chronological placement of several fossiliferous localities (palombo & milli, 2011; sardella & petrucci, 2012; marra et al., 2014). the name “san cosimato” has often been employed as a composite local fauna, including sporadic fossil findings recovered within the san cosimato formation (sensu conato et al., 1980; e.g., palombo, 2004). however, since deposits of the san cosimato formation are now known to represent two distinct sedimentary cycles correlated to valle giulia (mis 13) and san paolo (mis 11) formations (marra & rosa, 1995; funiciello & giordano, 2008), there are some ambiguities in referring to these assemblages (fig. 1). kotsakis et al. (1992) reported the presence of the two arvicolid rodents prolagurus pannonicus and ?predicrostonyx sp. from the “blue-grey helicella clays” (ponte galeria formation) at fontignano. these species are considered indicators of cold climate and are associated with an oligotypic assemblage of molluscs that also support this paleoclimatic inference. the local fauna constituted by prolagurus pannonicus and ?predicrostonyx sp. is the oldest in the area of ponte galeria and we refer to it as fontignano 1, to distinguish it from remains recovered from the upper levels (previously considered as san cosimato formation) of the same site, which represent fontignano 2. here we provide description and taxonomic attribution of the large mammal fossil remains of fontignano 2, which, although mentioned in several works (e.g., di https://doi.org/10.26382/amq.2021.07 156 iannucci a. et al. stefano & petronio, 1993; marra et al., 2014) have never been described so far. moreover, we discuss biochronological implications for the species recognized and we summarize the knowledge on san cosimato fossil assemblages. 2. materials and methods the fossil remains described in this work were recovered in the 1990s, during geological surveys carried out in the area of ponte galeria (salami, 1992), and they are housed in the paleofactory laboratory, department of earth sciences, sapienza university of rome (pf). the morphological analysis is based on the comparison with other fossil remains as well as recent osteological material stored in the same institution and in the university museum of earth science, department of earth sciences, sapienza, university of rome (must). measurements were taken with sliding calipers nearest to 0.1 mm, mainly following von den driesch (1976). we also measured the maximum anteroposterior depth of the distal epiphysis of the humerus (dapd). uncertain values are preceded by “c.” throughout the text. we considered: greatest length (gl); greatest length from caput (glc); smallest breadth of diaphysis (sd); anteroposterior distal diameter (dapd). other abbreviations employed in this work are as follows: faunal unit (fu); formation (fm); local fauna (lfa) 3. systematic palaeontology order artiodactyla owen, 1848 family bovidae gray, 1821 subfamily bovinae gray, 1821 genus bos linnaeus, 1758 species bos primigenius bojanus, 1827 material: right humerus (pf-font2-1; fig. 2a1-a2); left horn core (pf-font2-2; fig. 2b1-b2). description and comparison: the left horn core (pf -font2-2) also preserves part of the postero-lateral region of the cranium. it is in a better condition than that of the other specimen, although its posterior portion is damaged near the base of the horn. the cornual process is separated from the frontal bone by a marked neck; from this point it extends first laterally, and then anteriorly and upwards. the cross section of the horn is oval in the proximal preserved part, more elongated antero-posteriorly than dorso-ventrally. the right humerus (pf-font2-1) is almost complete but severely fractured, and its epiphyses are damaged at the level of the lateral tuberosity (proximally) and of the medial epicondyle (distally). the bone surface is partially encrusted by a grayish patina, with sporadic presence of small pebbles (1 5 cm in size). in the proximal epiphysis, the floor of the bicipital groove is swelling in anterior view. laterally, the lateral tuberosity possesses two shallow grooves. the diaphysis possesses a well -developed midshaft lateral imprint of the deltoid tuberfig. 1 location and geochronological setting of the studied area. the geological formations formerly included in the san cosimato formation are highlighted. data from: ambrosetti (1965); ambrosetti & bonadonna (1967); ambrosetti et al. (1972); caloi & palombo (1978, 1979b, 1986); kotsakis et al. (1978, 1992); conato et al. (1980); marra & rosa (1995); di stefano et al. (1998); petronio & sardella (1999); palombo (2004); milli et al. (2008); palombo & milli (2011); sardella & petrucci (2012); marra et al. (2014); sardella et al. (2015); pereira et al. (2018); boschian et al. (2019); mecozzi et al. (2021a). 157 large mammals from fontignano 2 osity in anterior view. in the distal epiphysis the lateral condyle is complete and appears laterally projected. laterally, the ridge connecting the main shaft with the lateral condyle curves at the level of the junction with the main shaft. the margin of the lateral epicondyle is short and curve, and originates below the lateral epicondylar crest. there are objective difficulties in the attribution of postcranial remains of bovidae to bison or bos (e.g., masini et al., 2013). nevertheless, pf-font2-1 is large, measuring c. 460.0 mm in gl, 391.7 mm in glc, and 78.8 mm in sd; and stout in appearance, especially at the level of the deltoid tuberosity. morphologically, most of the traits observed in pf-font2-1 fall in the variability of b. primigenius, whereas are different than those of bison (sala, 1986; balkwill & cumbaa, 1992). the morphological features, and the large size and robustness support an attribution to b. primigenius. pf-font2-2 can be confidently assigned to the same species. indeed, in bison the horns are inserted in the cranium in a more anterior position, and they have a different development, protruding outward and backward; in hemibos the horns are directed posteriorly, with a subtriangular cross section (petronio & sardella, 1998; martínez-navarro & palombo, 2004; masini et al., 2013). family cervidae goldfuss, 1820 subfamily cervinae goldfuss, 1820 genus cervus linnaeus, 1758 species cervus elaphus linnaeus, 1758 material: right antler (pf-font2-3; fig. 2e); left distal humerus (pf-font2-4; fig. 2c1-c4); right distal humerus (pf-font2-5; fig. 2d1-d2). description and comparison: the right antler pffont2-3 preserves only the basal part of the beam, with the insertion of the brown tine and the bez tine, but these two tines are broken. the beam shows pearls and knots typical of the red deer. the beam has an elliptical outline, with the major axis anteroposteriorly oriented. at the level of the insertion, the brow and bez tines have an elliptical outline, flattened mediolaterally. the lack of the tines prevents to estimate the angle that these form with the beam. the bez tine is near to the brow tine, disfig. 2 mammal remains from fontignano 2: bos primigenius right humerus pf-font2-1 in caudal (a1) and cranial (a2) views, left horn core pf-font2-2 in dorsal (b1) and frontal (b2) views; cervus elaphus left humerus pf-font2-4 in cranial (c1), caudal (c2), lateral (c3), and medial (c4) views, right distal humerus pf-font2-5 in caudal (d1) and cranial (d2) views, right antler pf-font2-3 in external view (e1). tanced 42.5 mm from the beam. above the bez tine, the beam is long 236.9 mm, and there is no trace of the trez tine. other measurements of the antler are: the anteroposterior breadth of the burr 64.9 mm; the mediolateral breadth of the burr 52.7 mm; the anteroposterior breadth of the beam between the brow and the bez tines 72.2 mm; the depth of the brow tine at the base 52.1 mm; the breadth of the brow tine at the base 30.4 mm; the depth of the bez tine at the base 34.4 mm; the breadth of the bez tine at the base 36.5 mm. the main differences between c. e. acoronatus and c. e. eostephanoceros is the terminal part of the antler, or crown (fig. 3). the acoronate red deer lacks a real crown, possessing a terminal fork with only two points (di stefano & petronio, 1992, 1993). on the contrary, the eostephanoceros red deer shows a real crown formed by at least 5 tines (di stefano & petronio, 1992, 1993). the most reliable features in the identification of red deer subspecies are missing in the antler from fontignano, which suggests caution in the taxonomical attribution. the left humerus (pf-font2-4) preserves part of the diaphysis and the distal epiphysis, but the medial condyle is fragmented. in anterior view, the radial pit is slightly larger than the coronoid pit; the epicondylar crest is damaged but appears robust; the capitulum is not preserved; the crest of the lateral condyle is more marked than that of medial condyle. posteriorly, the medial condyle is more pronounced than the lateral condyle; the olecranon fossa is wide distally, whereas is narrower, but deeper, proximally. pf-font-5 is a fragmented humerus diaphysis, lacking epiphyses. the morphology and size of the shaft resemble those of pffont2-4. the morphology of the humerus in fallow and red deer is quite similar, especially in the early middle pleistocene taxa. nevertheless, the relative development of the radial and coronoid pit is one of the diagnostic characters to differentiate the modern fallow deer and red deer (di stefano, 1995; lister, 1996). following this, pffont2-4 can be attributed to c. elaphus. considering the biometry, di stefano (1995) noticed that the angle described by the orientation of the trochlea is usually more acute in dama (<18°) than in cervus (>20°). in pffont2-4 this angle spans 20° and the dapd measures 53.8 mm, values that support an attribution to c. elaphus. 4. discussion 4.1. biochronological implications bos primigenius according to masini et al. (2013) b. primigenius is first documented in isernia fu, even though not from the type locality, but as a component of other lfas of the venosa basin in basilicata, namely notarchirico (cassoli et al., 1999) and loreto (caloi & palombo, 1979a). however, remains from these localities are scanty and mainly limited to postcranial material, elements not fully diagnostic in bovidae (moncel et al., 2020). indeed, masini et al. (2013, p. 54), discussing the morphological differences between b. priscus and b. primigenius, remarked that: “although a number of authors try to tell the difference between the postcranial elements, the objective difficulty of firmly identify either no diagnostic or imperfectly preserved remains of the large bovids, makes it difficult to ascertain the actual extent in time, space and number of findings of the steppe bison fossil record in italy”. moreover, the possibility that some remains of the enigmatic hemibos galerianus (petronio & sardella, 1998) may have been misidentified cannot be ruled out, since up to now the dental and postcranial morphology of this middle pleistocene bovid are still unknown. for instance, caloi & palombo (1979a) underlined the slenderness of postcranial remains of b. primigenius from loreto, but for reconciliate this evidence with the species attribution they argued that the sample likely consists mainly of female individuals. it is worth highlighting that the presence of h. galerianus in italy is documented only by two fragmentary horn cores collected from the lower level of cava di breccia di casal selce (petronio & sardella, 1998; martínez-navarro & palombo, 2004) and ponte molle (= ponte milvio) (martínez-navarro & palombo, 2007). martínez-navarro et al. (2010) stressed the importance of the coincidence between the dispersal of bos and the acheulean culture in eurasia. however, at notarchirico remains attributed to b. primigenius are only reported from the upper levels of the stratigraphic succession (cassoli et al., 1999), whereas the occurrence of the species cannot be confirmed in lower levels that document the earliest evidence of an acheulean settlement in italy (moncel et al., 2020; mecozzi et al. 2021b). a fragment of a frontal bone and a fragmentary proximal femur referred to b. primigenius were also found at monte oliveto (berzi, 1972), but a revision of 158 iannucci a. et al. tab. 1 middle pleistocene cervus taxa from europe considered in the text as established by authors. part there is a bifurcate fork (fig. 3a-b) (di stefano & petronio, 1992). the term acoronatus was chosen to indicate an antler where the terminal crown lacks, as opposite to the crown that instead characterizes the modern c. elaphus. the second taxon is c. e. eostephanoceros, recognizable for a first crown-like antler, even if different from that of the modern red deer (fig. 3c-e) (di stefano & petronio, 1993). as exemplified by the description above, the identification of red deer subspecies rests exclusively on antler morphology, which complicate the reconstruction of the evolutionary history of c. elaphus. indeed, antler remains are not ubiquitously represented in the fossil record, and underestimation of ontogenetically related morphological changes (e.g., presence/absence and number of tines, development of the crown) may led to misidentifications (heintz, 1970; lister, 1987). in italy, antler remains were collected from fontana ranuccio (di stefano & petronio, 1993), cava nera molinario (type locality of c. e. eostephanoceros) (di stefano & petronio, 1993), ponte molle (mecozzi et al., 2021a), via flaminia 8.2 km (kotsakis et al., 1978), riano (leonardi & petronio, 1974), torre del pagliaccetto (caloi et al., 1978), and castel di guido (sala & barbi, 1996). in europe, c. e. acoronatus was identified from the middle pleistocene sites of süssenborn and mosbach (type locality) (kahlke, 1960, 1969; lister, 1990; di stefano & petronio, 1992). two other putative red deer species were established on the sample of mosbach: “cervus” elaphoides kahlke, 1960 and this material is needed to confirm its classification. b. primigenius was also reported by valdemino (tozzi, 1969; nocchi & sala, 1997), but the material was never described or figured. finally, a nearly complete hemimandible from cava rinaldi was referred to b. primigenius by ambrosetti (1965), but later reassigned to bison sp. (sala, 1986; petronio & sardella, 1998). unequivocal fossil remains of b. primigenius are only known since fontana ranuccio fu, as exemplified by remains from fontana ranuccio (cassoli & segre naldini, 1993; strani et al., 2018), ponte molle (mecozzi et al., 2021a), and the horn core from fontignano 2 described in this work. in this scenario, an early dispersal of b. primigenius (older than fontana ranuccio fu) in the italian peninsula cannot be confirmed. in younger deposits, b. primigenius became soon a common element, as testified for example by the late middle pleistocene sites of malagrotta (caloi & palombo, 1979b) and castel di guido (sala & barbi, 1996). cervus elaphus the red deer, c. elaphus is a typical middle pleistocene species but is first documented from a few late early pleistocene sites (atapuerca-td4-6, van der made et al., 2017; bermúdez de castro et al., 1999; dorn dürkheim, franzen et al., 2000; happisburgh hsb3, parfitt et al., 2010). many chronological and/or geographical subspecies of c. elaphus were named (tab. 1), with a general agreement in recognizing the simpler antler morphology of earlier forms, but several alternative opinions on the validity and relationships of subsequent taxa (e.g., heintz, 1970; di stefano & petronio, 2002; van der made et al., 2014; croitor, 2018). in italy, largely relying on remains recovered from the area of rome, the red deer lineage is often considered to be represented by four different chronosubspecies: c. e. acoronatus (beninde, 1937), c. e. eostephanoceros di stefano & petronio, 1993, c. e. rianensis leonardi & petronio, 1974, c. e. elaphus (leonardi & petronio, 1974; di stefano & petronio, 1992, 1993, 2002), notwithstanding the occurrence of endemic island forms and of c. e. aretinus azzaroli, 1961 from tuscany (azzaroli, 1948, 1961; di stefano & petronio, 2002; croitor, 2018). the antler of the acoronatus red deer possesses five points, with two basal tines and a third tines in the high position on the beam, all directed anteriorly; while in the upper 159 large mammals from fontignano 2 fig. 3 antler morphology of cervus elaphus from localities of the area of rome: a ponte molle, b via flaminia km 8.2, c cava nera molinario, d ponte molle, e fontana ranuccio, f fontignano 2, g riano, h torre del pagliaccetto, i-l castel di guido; a-b c. e. acoronatus, c-e c. e. eostephanoceros, f c. elaphus ssp., g-l c. e. elaphus. figures not in scale. “cervus” reichenaui kahlke, 1995. however, lister (1990) recognized that specimens of “c.” elaphoides represented young individuals of c. e. acoronatus; and pfeiffer (1997) reassigned to dama (pseudodama) reichenaui the other taxon. other evidences of c. e. acoronatus were reported by di stefano & petronio (1992), but these were then reconsidered as dama (e.g., caune de l’arago, saint prest; lister, 1990) or the lack of antlers limits the attribution at the species level (e.g., atapuerca, azanza & sanchez, 1990). from the middle pleistocene locality of mauer was instead reported the subspecies c. e. priscus (kaup, 1839), a form considered different from c. e. acoronatus in having an incipient crown, with six points (instead of the maximum of 5 points in c. e. acoronatus). c. e. eostephanoceros was only reported from hundsheim (di stefano & petronio, 1993). subsequent recovery and description of new material confirm the occurrence of c. e. acoronatus at caune de l’arago, and also of c. e. priscus (or c. e. eostephanoceros), providing evidence of a turnover of two forms between mis 13 and mis 12 (magniez et al., 2013). the authors, however, referred the younger form to c. e. priscus (or c. e. eostephanoceros), reflecting the close morphological affinity and uncertain relationship between these two taxa. of considerable interest for red deer evolution is the sample recovered at steinheim, which was referred to c. e. angulatus beninde, 1937. eleven complete or nearly complete antlers were illustrated by beninde (1937), showing a huge morphological variability. another taxon was proposed, based on the sample from the middle pleistocene site of riano, c. e. rianensis (leonardi & petronio, 1974). as reported by the authors, the four antlers recovered from this site show a large variability in number of points (five or six) and development of the crown. although there are slight differences between the antler from riano and those of the modern red deer, no subspecies separation would seem supported (fig. 3g-l). in this respect, the antler found in the via flaminia km 8.2 deposit, initially referred to c. e. rianensis (kotsakis et al., 1978) is particularly relevant (fig. 3b). in fact, the chronostratigraphic revision of this deposit was carried out by marra et al. (2018), who referred the fossil level to mis 13. the authors, in addition, noticed that the antler is closer to c. e. acoronatus rather than to c. e. rianensis. considering that the type material of c. e. eostephanoceros from cava nera moli 160 iannucci a. et al. fig. 4 mammal remains from via di brava: palaeloxodon antiquus molar pf-brava-1 in occlusal view (a); and san cosimato: bos primigenius right upper first molar mpur sn019/lj in occlusal view (b), stephanorhinus sp. left lower third or fourth premolar mpur sn023/lj in buccal view (c), castor fiber left lower fourth premolar mpur sn021/lj in occlusal view (d). nario is also correlated to mis 13 but placed in a lower stratigraphic position (marra et al., 2014, 2018), this suggests a chronological overlap between the two forms. 4.2. san cosimato assemblages apart from b. primigenius and c. elaphus from fontignano 2, there are several other remains recovered from the san cosimato fm of conato et al. (1980) (fig. 4). palombo (2004) provided a faunal list, even though without further details on the provenance or description of the material: stephanorhinus sp., ?dama sp., cervus cf. c. e. eostephanoceros, b. primigenius, and castor fiber. however, the fossils reported by conato et al. (1980) (emys orbicularis, beavers, and rhinoceros) and other associated remains are housed in must and catalogued as from “via della pisana san cosimato”, suggesting that they were recovered from the outcrops of the san cosimato fm at via della pisana, now referred to the mis 11 sedimentary cycle (san paolo fm; marra et al., 2014). salami (1992) also mentioned the recovery of a fragmentary molar of palaeoloxodon antiquus from an outcrop of the san cosimato fm at via di brava (fig. 4a). this specimen is housed in pf, but it is not accompanied by more precise stratigraphic information that would allow a correlation with updated fms, and therefore it could be either mis 13 or mis 11 in age (valle giulia or san paolo fms). finally, palombo & ferretti (2005) reported undescribed remains of mammuthus trogontherii from fontignano (rome) housed in the geological museum “giovanni capellini” of bologna. however, this is a mistake resulting from a case of homonymy. in fact, according to verri (1886) the material stored in bologna was recovered from fontignano in umbria (near perugia). 5. conclusion three distinctive lfas can be recognized under the name san cosimato: fontignano 2 (mis 11), with b. primigenius and c. elaphus; via di brava (mis 13 or mis 11), with p. antiquus; and san cosimato (mis 11), with stephanorhinus sp., b. primigenius, c. fiber, and e. orbicularis. according to palombo (2004), to this list can be added ?dama sp. we argue that the name san cosimato should be restricted to the lfa. indeed, for bichronological correlations and paleoecological inferences it would be more desirable to refer to updated fms (e.g., funiciello & giordano, 2008), or to geochronologically constrained localities withing them (milli et al., 2008; marra et al., 2014; sardella et al., 2015). the study of the fossils collected from fontignano 2 reveals the presence of b. primigenius and c. elaphus. an overview of the bovid sample of the middle pleistocene sites of the italian peninsula suggests a first dispersal of b. prigeminius in fontana ranuccio fu, with no clear evidence of an earlier diffusion (isernia fu). the geological revision of many fossiliferous sites of the city of rome and its surroundings allowed to update their chronology. in this new scenario, the two red deer subspecies, c. e. acoronatus and c. e. eostephanoceros, seem to overlap in time during mis 13, as testified by the lower stratigraphic position of the type material of c. e. eostephanoceros from cava nera molinario than that of c. e. acoranatus from via flaminia km 8.2. the coexistence of two red deer subspecies within a so restricted geographical area is hardly conceivable and may reflects the shortcomings of a dichotomic separation in the absence of a clear understanding of population variability. in this respect it is worth to remark that the replacement between acoronated and coronated forms occurring at caune de l’arago during the mis 13 mis 12 transition is not abrupt (magniez et al., 2013), and the presence of more advanced morphologies within the samples of mosbach and mauer was also noted (lister, 1987; di stefano & petronio, 1993). more in general, complete antler remains of c. elaphus from the pleistocene of europe are scanty, and other morphological and biometric analyses are needed to complement our knowledge on the evolution of the species (lister et al., 2010; magniez et al., 2013; van der made et al., 2014; iannucci et al., 2020). the description of the fossil remains from fontignano 2 highlights the importance of adding faunal element with a clear chronological context for the reconstruction of the quaternary terrestrial ecosystem of the euro-mediterranean area. acknowledgements we thank the soprintendenza speciale di roma, archeologia, belle arti e paesaggio for the agreement of the field activities on the area of rome. we are grateful to linda riti and michele macri for the help and support during the study of the fossil collection of must. we wish to thank ilaria mazzini, luca bellucci, dawid adam iurino, flavia strani and jacopo conti for their useful suggestions and support. we also thank gbola salami for having carried out the geological and stratigraphical reconstruction of selected sedimentary successions of the ponte galeria area and for collecting fossil remains from these deposits. we are thankful for helpful comments and suggestions provided by two anonymous reviewers. references ambrosetti p. (1965) segnalazione di una fauna con elephas antiquus nella zona di ponte galeria (roma). bollettino della società geologica italiana, 84(1), 15-28. ambrosetti p., bonadonna f.p. (1967) revisione dei dati sul plio-pleistocene di roma. atti accademia gioenia di scienze naturali in catania, 18, 33-70. ambrosetti p., azzaroli a., bonadonna f.p., follieri m. (1972) a scheme of pleistocene chronology for the tyrrhenian side of central italy. bollettino della società geologica italiana, 91, 169-184. azanza b., sanchéz b. (1990) les cervidés du pléistocène moyen d’atapuerca (burgos, espagne). quaternaire, 3-4, 197-212. azzaroli a. (1948) i cervi fossili della toscana con particolare riguardo alle specie villafranchiane. paleontographia italica, 43, 45-81. azzaroli a. (1961) il nanismo dei cervi insulari. palaeontographia italica, 56, 1-32. 161 large mammals from fontignano 2 balkwill d., cumbaa s.l. (1992) guide to the identification of postcranial bones of bos taurus and bison bison. canadian museum of nature. beninde j. (1937) über die edelhirschformen von mosbach, mauer und steinheim a. d. murr. paläontologische zeitschrift, 19(1), 79-116. berzi a. (1972) an early middle pleistocene fauna at monte oliveto (s. giaminiano, siena, italy). palaeontographia italica, 68, 28-33. bermúdez de castro j.m., arsuaga j.l., carbonell e., rosas a., martínez i., mosquera m. (1997) a hominid from the lower pleistocene of atapuerca, spain: possible ancestor to neandertals and modern humans. science, 276, 1392-1395. boschian g., caramella d., saccà d., barkai r. (2019) are there marrow cavities in pleistocene elephant limb bones, and was marrow available to early humans? new ct scan results from the site of castel di guido (italy). quaternary science reviews, 215, 86-97. caloi l., palombo m.r. (1978) anfibi, rettili e mammiferi di torre del pagliaccetto (torre in pietra, roma). quaternaria, 20, 315-428. caloi l., palombo m.r. (1979a) la fauna quaternaria di venosa: bovidi. bollettino del servizio geologico italiano, 100, 101-140. caloi l., palombo m.r. (1979b) resti di mammiferi del pleistocene medio di malagrotta (roma). bollettino del servizio geologico italiano, 100, 141-188. caloi l., palombo m.r. (1986) le mammalofaune pliopleistocene dell’area laziale: problemi biostratigrafici ed implicazioni paleoclimatiche. memorie del servizio geologico italiano, 35, 99-126. cassoli f., di stefano g., tagliacozzo a. (1999) i vertebrati dei livelli superiori (alfa ed a) della serie stratigrafica di notarchirico. in: notarchirico: un sito del pleistocene medio iniziale nel bacino di venosa (ed. by piperno m.). edizioni osanna, venosa, italia, 361-438. cassoli f., segre naldini e. (1993) le faune. in: dives anagnia. archeologia della valle del sacco (ed. by gatti s.). l’erma di bretschneider, 30-38. conato v., esu d., malatesta a., zarlenga f. (1980) new data on the pleistocene of rome. quaternaria, 22, 131-176. conticelli s., peccerillo a. (1992) petrology and geochemistry of potassic and ultrapotassic volcanism in central italy: petrogenesis and inferences on the evolution of the mantle source. lithos, 28, 221240. croitor r. (2018) plio-pleistocene deer of western palearctic: taxonomy, systematics, phylogeny. institute of zoology of the academy of sciences of moldova, chişină u, pp. 140. de rita d., funiciello r., corda l., sposato a., rossi u. (1993) volcanic units. in: sabatini volcanic complex (ed. by di filippo m.), consiglio nazionale del le ricerche, progetto final izzato “geodinamica” monografie finali, 11, 33-79. di stefano g. (1995) identification of fallow deer remains on the basis of its skeletal features: taxonomical considerations. bollettino della società paleontologica italiana, 34(3), 323-331. di stefano g., petronio c. (1992) nuove osservazioni su cervus elaphus acoronatus beninde del pleistocene europeo. bollettino della società paleontologica italiana, 31(3), 295-315. di stefano g., petronio c. (1993) a new cervus elaphus subspecies of middle pleistocene age. neues jahrbuch für geologie und paläontologie, 190(1), 1-18. di stefano g., petronio c. (2002) systematics and evolution of the eurasian plio-pleistocene tribe cervini (artiodactyla, mammalia). geologica romana, 36, 311-334. di stefano g., petronio c., sardella r. (1998) biochronology of pleistocene mammal faunas from rome urban area. il quaternario, 11, 191-199. driesch von den a. (1976) a guide to the measurement of animal bones from archaeological sites. peabody museum bull., 1, 1-136. franzen j.l., gliozzi e., jellinek t., scholger r., weidenfeller m. (2000) die spätaltpleistoäne fossillagerstätte dorn-dürkheim 3 und ihre bedeutung für die rekonstruktion der entwicklung des rheinischen flußsystems. senckenbergiana lethaea, 80(1), 305-353. funiciello r., giordano g. (2008) note illustrative della carta geologica d’italia alla scala 1:50.000, foglio 374 roma. apat, dipartimento difesa del suolo, servizio geologico d’italia, pages 158. heintz e. (1970) les cervidés villafranchiens de france et d'espagne. mémoires du muséum national d’histoire naturelle. série c, sciences de la terre, 22, 1-303. iannucci a., sardella r., strani f., mecozzi b. (2020) size shifts in late middle pleistocene to early holocene sus scrofa (suidae, mammalia) from apulia (southern italy): ecomorphological adaptations? hystrix, 31(1), 10-20. karner d.b., marra f., renne p.r. (2001) the history of the monti sabatini and alban hills volcanoes: groundwork for assessing volcani-tectonic hazards for rome. journal of volcanology and geothermal research, 107, 185-219. kahlke h.-d. (1960) die cervidenreste aus den altpleistozänen sanden von mosbach (biedrich wiesbaden). abhandlungen der deutschen akademie der wissenschaften zu berlin, 7, 1-75. kahlke h.-d. (1969) die cerviden-reste aus den kiesen von süssenborn bei weimar. paläontologische abhandlungen, a 3(3/4), 547-609. kahlke h.-d. (1995) der “kleine hirsch” aus dem unteren mittelpleistozän von mosbach (wiesbadenbieberich). beiträge zur geologie von thüringen. neue folge, 2, 97-100. kaup j.j. (1839) eine zweite fossile art der hirschgattung aus dem rheine, cervus priscus. neues jahrbuch für mineralogie, geognosie. geologie und petrefakten-kunde, 297-300. kotsakis t., palombo m.r., petronio c. (1978) mammuthus chosaricus e cervus elaphus del pleistocene superiore di via flaminia (roma). geologica romana, 17, 411-445. kotsakis t., esu d., girotti o. (1992) a postvillafranchian cold event in central italy testified by 162 iannucci a. et al. continental molluscs and rodents. bollettino della società geologica italiana, 111, 335-340. leonardi g., petronio c. (1974) i cervi pleistocenici del bacino diatomitico di riano (roma). memorie dell’accademia nazionale dei lincei, 12, 103-208. lister a.m. (1987) diversity and evolution of antler form in quaternary deer. in: biology and managment of the cervidae (ed. by wemmer c.m.). washington smithsonian institution, washington, 81-98. lister a.m. (1990) critical reappraisal of the middle pleistocene deer species ‘‘cervus’’ elaphoides kahlke. quaternaire, 3-4, 175-192. lister a.m. (1996) the morphological distinction between bones and teeth of fallow deer (dama dama) and red deer (cervus elaphus). international journal of osteoarchaeology, 6, 119-143. lister a.m., parfitt s.a., owen f.j., collinge s.e., breda m. (2010) metric analysis of ungulate mammals from the early middle pleistocene of britain, in relation to taxonomy and biostratigraphy. ii: cervidae, equidae and suidae. quaternary international, 228, 157-179. magniez p., moigne a.-m., testu a., de lumley h. (2013) biochronologie des mammifères quaternaires. apport des cervidae du site pléistocène moyen de la caune de l’arago (tautavel, pyrénées-orientales, france). quaternaire, 24(4), 477502. marra f., rosa c. (1995) stratigrafia e assetto geologico dell’area romana. memorie descrittive della carta geologica d’italia, 50, 49-118. marra f., pandolfi l., petronio c., di stefano g., gaeta m., salari. l. (2014) reassessing the sedimentary deposits and vertebrate assemblages from ponte galeria area (rome, central italy): an archive for the middle pleistocene faunas of europe. earth-science reviews, 139, 104-122. marra f., nomade s., pereira a., petronio c., salari l., sottili g., bahain j.j., boschian g., di stefano g., falguerès c., florindo f., gaeta m., giaccio b., masotta m. (2018) a review of the geologic sections and the faunal assemblages of aurelian mammal age of latium (italy) in the light of a new chronostratigraphic framework. quaternary sciences reviews, 181, 173-199. martínez-navarro b., palombo m.r. (2004) occurrence of the indian genus hemibos (bovini, bovidae, mammalia) at the early-middle pleistocene transition in italy. quaternary research, 61, 314317. martínez-navarro b., palombo m.r. (2007) the horncore of hemibos galerianus from ponte milvio, rome (italy). rivista italiana di paleontologia e stratigrafia, 113, 531-534. martínez-navarro b., rook l., papini m., lisbekal y. (2010) a new species of bull from the early pleistocene paleoanthropological site of buia (eritrea): parallelism on the dispersal of the genus bos and the acheulian culture. quaternary international, 212, 169-175. masini f., palombo m.r., rozzi r. (2013) a reappraisal of the early to middle pleistocene italian bovidae. quaternary international, 288, 45-62. mecozzi b., iurino d.a., profico a., rosa c., sardella r. (2020) the wolf from the middle pleistocene site of ostiense (rome): the last occurrence of canis mosbachensis (canidae, mammalia) in italy, historical biology, pp. 1-12. doi: 10.1080/08912963.2020.1769090 mecozzi b., iannucci a., mancini m., sardella r. (2021a) redefining ponte molle (rome, central italy): an important locality for middle pleistocene mammal assemblages of europe. alpine and mediterranean quaternary, 34(1), 131-154 mecozzi b., iannucci a., sardella r., curci a., daujeard c., moncel m-h. (2021b) macaca ulna from new excavations at the notarchirico acheulean site (middle pleistocene, venosa, southern italy). journal of human evolution, 153, 102946. milli s., moscatelli m., palombo m.r., parlagreco l., paciucci m. (2008) incised-valleys, their filling and mammal fossil record: a case study from middle-upper pleistocene deposits of the roman basin (latium, italy). geoacta, special publication, 1, 67-88. moncel m.h., santagata c., pereira a., nomade s., voinchet p., bahain j.j., daujeard c., curci a., lemorini c., hardy b., eramo g., berto c., raynal j.p., arzarello m., mecozzi b., iannucci a., sardella r., allegretta i., delluniversità e., terzano r., dugas p., jouanic g., queffelec a., d’andrea a., valentini r., minucci e., carpentiero l., piperno m. (2020) the origin of early acheulean expansion in europe 700 ka ago: new findings at notarchirico (italy). scientific reports, 10(1), 1-16. nocchi g., sala b. (1997) the fossil rabbit from valdemino cave (borgio verezzi, savona) in the context of western europe oryctolagini of quaternary. palaeovertebrata, 26(1), 167-187. palombo m.r. (2004) le mammalofaune della campagna romana: biocronologia, paleoambienti. ii congresso geosed, escursione precongresso, roma, 1-29. palombo m.r., ferretti m.p. (2005) elephant fossil record from italy: knowledge, problems, and perspectives. quaternary international, 126, 07-136. palombo m.r., milli s. (2011) mammalian fossil record, depositional setting, and sequence stratigraphy in the middle-upper pleistocene of roman basin. il quaternario, 23(2), 243-248. parfitt s., ashton n., lewis s., abel r., coope g.r., field m., gale r., hoare p., larkin n., lewis m., karloukovski v., maher b., peglar s., preece r., whittaker j., stringer c. (2010) early pleistocene human occupation at the edge of the boreal zone in northwest europe. nature, 466, 229-233. pereira a., nomade s., moncel m., voinchet p., bahain j., biddittu i., falguères c., giaccio b., manzi g., parenti f., scardia g., scao v., sottili g., vietti a. (2018) integrated geochronology of acheulian sites from the southern latium (central italy): insights on human-environment interaction and the technological innovations during the mis 11-mis 10 period. quaternary science reviews, 187, 112129. 163 large mammals from fontignano 2 petronio c., sardella r. (1998) bos galerianus n. sp. (bovidae, mammalia) from the ponte galeria formation (rome, italy). neues jahrbuch für geologie und paläontologie-monatshefte, 269-284. petronio c., sardella r. (1999) biochronology of the pleistocene mammal fauna from ponte galeria (rome) and remarks on the middle galerian faunas. rivista italiana di paleontologia e stratigrafia, 105(1), 155-164. pfeiffer t. (1997) dama (pseudodama) reichenaui (kahlke 1996) (artiodactyla: cervidae, cervini) aus den mosbach-sanden (wiesbaden-biebich). mainzer naturwissenschaftliches archiv, 35, 3159. sala b. (1986) bison schoetensacki freud. from isernia la pineta (early mid-pleistocene, italy) and revision of the european species of bison. palaeontographia italica, 74, 113-170. sala b., barbi g. (1996) descrizione della fauna. in: gli scavi a castel di guido, il più antico giacimento di cacciatori del paleolitico inferiore nell’agro romano (ed. by radmilli a.m., boschian g.). istituto italiano di preistoria e protostoria, firenze, 55-90. salami g.i. (1992) rilevamento geologico-strutturale del settore magliana-ponte galeria. master thesis, università degli studi di roma “la sapienza”, roma, pp. 97. sardella r., petrucci m. (2012) the earliest middle pleistocene crocuta crocuta (erxleben, 1777) at casal selce (rome, italy). quaternary international, 267, 103-110. sardella r., bedetti c., iurino d.a., pavia m., bellucci l. (2015) comment on “reassessing the sedimentary deposits and vertebrate assemblages from ponte galeria area (rome, central italy): an archive for the middle pleistocene faunas of europe” by f. marra, l. pandolfi, c. petronio, g. di stefano, m. gaeta, l. salari [earth-science reviews 139 (2014), 104-122]. earth-science reviews, 147, 201-203. strani f., demiguel d., bona f., sardella r., biddittu i., bruni l., de castro a., guadagnoli f., bellucci l. (2018) ungulate dietary adaptations and palaeoecology of the middle pleistocene site of fontana ranuccio (anagni, central italy). palaeogeography, palaeoclimatology, palaeoecology, 496, 238247. tozzi c. (1969) segnalazione di una grotta con fauna fossile a borgio (savona). atti della società toscana di scienze naturali, memorie a, 76(1), 195-208. van der made j., stefaniak k., marciszak a. (2014) the polish fossil record of the wolf canis and the deer alces, capreolus, megaloceros, dama and cervus in an evolutionary perspective. quaternary international, 326, 406-430. van der made j., rosell j., blasco r. (2017) faunas from atapuerca at the early-middle pleistocene limit: the ungulates from level td8 in the context of climatic change. quaternary international, 433, 296-346. verri a. (1886) azione delle forze nell’assetto delle valli con appendice sulla distribuzione dei fossili nella valdichiana e nell’umbria interna settentrionale. bollettino della società geologica italiana, 5, 416451. 164 iannucci a. et al. ms. received: january 15, 2021 revised: march 1, 2021 accepted: march 16. 2021 avaiable online: april 14, 2021 amq 185-197 valente et al.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 32 (2), 2019, 185 197 late quaternary geomorphological evolution and evidence of post-campania ignimbrite (40 ka) fault activity in the inner sector of the sarno plain (southern apennines, italy) ettore valente1*, alessandra ascione1, nicoletta santangelo1, antonio santo2 1 distar, dipartimento di scienze della terra, dell’ambiente e delle risorse, università degli studi di napoli federico ii, naples, italy. 2 dicea, dipartimento d’ingegneria civile, edile e ambientale, università degli studi di napoli federico ii, naples, italy. corresponding authors: e. valente <ettore.valente@unina.it> abstract: the sarno plain corresponds to the southernmost sector of the campana plain peri-tyrrhenian graben, and it is limited towards the northwest by the somma-vesuvius volcanic edifice. the sarno plain corresponds to the depocenter of a quaternary sedimentary basin which is more than 2000 m thick and is bounded by high angle faults with ne-sw, e-w and nw-se trends. our study focussed on the less investigated, inner part of the sarno plain, and aimed at reconstructing the recent (late pleistocene holocene) geomorphological and tectonic evolution of the area. the study was based on detailed geomorphological investigation combined with subsurface stratigraphic analyses of around 80 borehole logs. the geomorphological-stratigraphical approach has allowed the identification of the main geomorphological features of the alluvial plain and adjacent piedmont areas, and the reconstruction of the shallow subsurface setting of the inner sarno plain. the results indicate post-late pleistocene subsidence of the investigated area and the presence of an articulated fault system at the northeastern boundary of the investigated area. surface morphological features and the characteristics of the drainage network are consistent with the subsurface stratigraphy in pointing to the activity of e-w and nw-se trending fault strands during the late quaternary. overall evidence suggests the occurrence of vertical displacements postdating the emplacement of the campania ignimbrite regional chronostratigraphical marker, which implies fault activity continuing in the last 40 ka in the inner part of the densely populated sarno plain. keywords: active faults, campania ignimbrite, southern apennines, italy.   1. introduction unravelling recent displacements along the faults at the boundaries of the campania plain quaternary coastal graben, in the southern apennines, is a challenging task. difficulty arises mainly from intense urbanization and high-rate sediment accumulation during late quaternary times. in fact, in the circum-volcanic region of the campania plain, several explosive eruptions supplied pyroclastic sediments with repeated and abundant inputs which favoured filling of the basin and forced coastal progradation (brancaccio et al., 1991; 1995; santangelo et al., 2017). in the piedmont belts, abundant pyroclastic deposition, possibly in excess of fault slip, eventually masked the near-fault surface evidence of recent displacements along the faults at the boundaries of the plain (ascione & cinque, 2003). in such a scenario, the topographic expression of recent fault offsets is expected to be subdued and the identification of recent fault offsets fundamentally rests on the coupling of detail scale geomorphological analysis with careful interpretation of subsurface stratigraphy data. we have investigated the sarno plain, which is part of the major campania plain coastal graben, with the aim of reconstructing the late quaternary activity of the fault strands at the boundary of the sedimentary basin and constraining the age and the amount of their recent displacements. in the campania plain basin, the interaction between vertical motions and sea-level fluctuations controlled the accumulation of thousands-of-meters thick successions of marine, transitional and continental deposits during the quaternary (e.g., santangelo et al., 2017, and reference therein). the marine to continental sediments are interlayered with products emitted, through effusive and explosive eruptions, by several volcanic centres (santangelo et al., 2017, and reference therein). major ne-sw to e-w trending and nw-se trending high angle extensional faults separate different sub-basins within the campania plain (e.g., caiazzo et al., 2006; cella et al., 2007; milia &torrente, 2015), with the sarno plain corresponding to the south-easternmost one. associated with the normal fault systems are features like mineral springs, travertine/tufa deposits and sinkholes. by regional scale evidence from the central and southern apennines (santo et al., 2011; ascione et al., 2014), which indicates that such features cluster along active faults that dissect the topographic surface, https://doi.org/10.26382/amq.2019.13 186 valente e. et al. recent activity of the faults at the boundaries of the campania plain may be inferred. indeed, holocene displacement along the western segment of the normal fault system that bounds the sarno plain towards the se has been inferred from subsurface stratigraphy (irollo et al., 2005). on the other hand, late pleistoceneholocene activity of the faults at the boundaries of the less investigated inner part of the sarno plain, has not been assessed to date (e.g., cinque et al., 2000). our study focuses on the north-eastern part of the sarno plain and is based on a detailed geomorphological investigation combined with the analyses of subsurface stratigraphy data from both deep (depth >30 m) and shallow (depth <30 m) boreholes. 2. geological setting the sarno plain is located in the tyrrhenian flank of the southern apennines fold-and-thrust belt (mazzoli &helman, 1994; cello &mazzoli, 1999; turco et al., 2012). since the late miocene, thrust tectonics along the north-eastern side of the chain was accompanied by extensional tectonics along the southwestern flank, where the tyrrhenian extensional basin was formed (malinverno & ryan, 1986; patacca et al., 1990; cinque et al., 1993; doglioni et al., 2004). since the early quaternary (calabrian), crustal stretching driven by nw-se oriented extension caused the lowering, for thousands of meters, of the chain units and the formation of large peri-tyrrhenian grabens named, from the n to the s, the garigliano plain, the campania plain, the sele plain and the policastro gulf (e.g., sartori, 1990, 2003; caiazzo et al., 2006; aucelli et al., 2012; santangelo et al., 2017 and reference therein; fig. 1). during the middle pleistocene, thrust tectonics ceased and extensional tectonics affected the axial portion of the chain causing the formation of large intermontane basins (russo ermolli et al., 2010; amato et al., 2014, 2017; ascione et al., 2018), whereas the outer flank of the chain experienced surface uplift (cinque et al., 1993) accompanied by ne shifting of the apennine divide (buscher et al., 2017). in the campania plain graben, extensional faulting was accompanied by volcanism. during the quaternary, several volcanic centres located both inland and offshore were active and, since the late part of the middle pleistocene, volcanism was active in the phlegrean fields area and somma-vesuvius volcano (e.g., rolandi et al., 2003; de alteriis et al., 2006; milia et al., 2013; santangelo et al., 2017; misuraca et al., 2018). volcanism climaxed with the catastrophic campania ignimbrite eruption, recently dated at 39.85 ±0.14 ka (giaccio et al., 2017), which caused emplacement of several tens of m thick deposits in a large area spanning over the campania region (de vivo et al., 2001; rolandi et al., 2003), that morphologically corresponds to a widespread plateau. based on geophysical data, three main depocenters have been distinguished within the campania plain graben (e.g., cella et al., 2007; milia &torrente, 2015), with the south-eastern one corresponding with the sarno plain. the southern boundary of the sarno plain is defined by a fault system composed of mainly ne-sw and e-w trending segments, located at the toe of the lattari mts. slopes (cinque, 1991; irollo et al., 2005), while to the northeast the plain is bounded by a nw-se trending fig. 1 simplified geological map of the southern apennines (modified from santo et al., 2019). black box indicates location of the study area. earthquakes epicentres are derived from rovida et al., (2016). 187 the sarno plain recent evolution and post-40 ka faulting fault running at the base of the monti di sarno mts. (cinque et al., 1987; cinque, 1991; fig. 1). the hillslopes of the lattari mts. and monti di sarno mts. consist of a carbonate succession of jurassic to cretaceous age (sheet 448-ercolano, ispra, 2014a; sheet 466-sorrento, ispra, 2014b). between these major ridges, a downfaulted belt consisting of the upper part of the carbonate succession (cretaceous; sheet 448ercolano; ispra, 2014a) is present. towards nw, the sarno plain is limited by the somma-vesuvius volcanic edifice. thickness of the quaternary filling of the sarno plain is constrained by the trecase 1 well (bernasconi et al., 1981; balducci et al., 1983; brocchini et al., 2001), which is located in the western sector of the plain, at the base of the somma-vesuvius volcano. the well is 2072 m deep and the carbonate bedrock has been found at depth of 1882 m. 40ar/39ar and biostratigraphy of the trecase 1 core suggest a middle pleistocene age for the upper ~1000 m part of the basin fill (brocchini et al., 2001). the 275-290 m-deep fallout deposit of the trecase 1 well is correlated with the 25 ka codola eruption (alessio et al., 1974), which testifies to the onset of the somma volcanic activity. the recent (late part of upper pleistocene to holocene) evolution of the western part of the sarno plain, and its relationship with relative sea-level fluctuations, fig. 2 geological map of the inner corner of the sarno plain. black boxes indicate main localities listed in the text. white contour lines indicate the top surface of the campania ignimbrite (in meters a.s.l.). has been reconstructed in detail in several works (cinque & russo, 1986; cinque et al., 1987; barra et al., 1989; albore livadie et al., 1990; cinque, 1991; cinque & irollo, 2004). these studies identified the late stages of coastal progradation that followed the maximum holocene ingression, which reached ~8 km inland of the present-day coastline (cinque, 1991). in addition, basing on age constraints on the sediments buried at shallow depths, holocene subsidence-postdating the maximum holocene ingression-of the southwestern part of the sarno plain has been inferred (e.g., albore livadie et al., 1990). less constrained is the subsurface stratigraphical setting and recent evolution of the inner (eastern) part of the sarno plain. in the subsurface of that area, marine and transitional deposits have been drilled down to depths >200 m (nicotera & civita, 1969) and the presence of several tens of m of buried thick deposits of the campania ignimbrite chronostratigraphic marker has been reported (nicotera & civita, 1969; cinque, 1991; aprile & toccaceli, 2002). the recent late pleistocene holocene activity of the western part of the fault system bounding the sarno plain towards the south has been inferred from subsurface stratigraphy (irollo et al., 2005) and current extensional deformation has been identified from faults affecting the somma-vesuvius volcanic edifice (tramparulo et al., 2018). however, besides low-energy earthquakes related with the vesuvius volcano area (http:// www.ov.ingv.it/ov/), the sarno plain lacks significant historical seismicity, while low to moderate magnitude earthquakes have affected the surroundings of the plain. the strongest events are represented by the mw =5.56, 1499 earthquake and the mw =5.56, 1561 earthquake, whose epicentres are located ~15 km to the nw and se of the sarno plain respectively (rovida et al., 2016; fig. 1). 3. methods the work has been based on the combination of field survey, geomorphological analysis of large-scale topographic maps and reinterpretation of stratigraphical data from a total of 80 boreholes, both published and unpublished. the geomorphological investigation has been based on the analysis of technical maps of the campania region at scale 1:5000 and a high-resolution digital terrain model (lidar dtm, 1x1 m horizontal resolution, which cover the entire study area). the combination of both datasets allowed the identification of the main features of the topographic and hydrographic networks of the investigated area. borehole data include 8 boreholes from guarino & nisio (2009), 12 boreholes from nicotera & civita (1969), 35 boreholes from the ispra database (http:// sgi2.isprambiente.it/mapviewer/), 25 boreholes from the 188 fig. 3 a) geomorphological map of the inner sector of the sarno plain. svt = striano san valentino torio topographic high. b) historical topographic map of the inner sector of the sarno plain with 10 m spaced contour lines (from morano, 1882). valente e. et al. piano urbanistico comunale of the sarno municipality, and one deep borehole from cinque et al. (1987). depths of the boreholes range from 15 m to 252 m. borehole data have been imported in a gis software (arcgis 10.7 ©), converted in a point shapefile and a database has been associated to this shapefile. the latter include information about the absolute elevation of the main stratigraphic units that have been distinguished. these data have been then plotted on a hillshade map of the north-eastern corner of the sarno plain, that has been derived from the 1x1 m lidar dtm. elevation data from the lidar data were used for the construction of two cross-sections representative of the subsurface setting of the sarno plain. 4. results 4.1. geomorphological features of the inner sarno plain the sarno plain is an ~50 km2 large and substantially flat alluvial plain. it is crossed by the sarno river, which originates from the merging of three streams (namely the acqua di palazzo, acqua di san marino and acqua della foce streams; fig. 2) fed by springs located along the monti di sarno mountain front. some man-made interventions have partially modified the hydrography of the sarno plain, with the construction of the acqua della foce artificial, rectilinear canal and the bending of the solofrana river towards the north, in order to make it flow into a roughly e-w trending stream fed by the spring located at the base of mt. torricchio (morano, 1882; fig. 3b). along the sarno plain, alluvial terraces are lacking, and the elevation increases to maximum values around 30 m along the adjacent piedmont areas. the analysed area of the sarno plain spans between the straight, roughly e-w trending mountain front of the lattari mts., in the south, and the slopes of the monti di sarno ridge, in the northeast (fig. 2), where the springs originating the sarno river are located. in the lowered belt located between the steep scarps of the lattari and monti di sarno mts., the smooth and low hills of the mt. torricchio ridge (maximum elevation around 600 m) form the eastern limit of the sarno plain (fig. 2). the lattari mts. mountain front (fig. 3a) is characterised by planar slopes and triangular facets formed in the mesozoic carbonate rocks. the monti di sarno ridge has maximum elevation of 1125 m a.s.l. in correspondence of the pizzo d’alvano mt., and an articulated perimeter characterised by two large embayment (namely, the episcopio and lavorate embayment; fig. 2; fig. 3a), with an overall nw-se trend. in the piedmont belt of the lattari mts. and in the embayment located at the toe of the monti di sarno mts., two generation of coalescent alluvial fans may be distinguished, locally interrupted by debris slopes. alluvial fans from the lattari mts. ridge surround the downfaulted carbonate hill of pagani (fig. 2). alluvial fans of the 1st generation are dissected and are steeper than those of the 2nd generation. the latter ones are wider and gently graded to the adjacent alluvial plain. deposits of the alluvial fans of the 2nd generation that form the piedmont of the monti di sarno 189 mts. are well exposed in the lavorate embayment, along the ~ 25 m high walls of a ~ 200 m wide cover collapse sinkhole (fossa san vito sinkhole; santo et al., 2019; fig. 2; fig. 3a). they consist of gravels composed of carbonate clasts alternated with pyroclastic layers, that overlie the campania ignimbrite (hereinafter, ci), a regional chronostratigraphic marker layer ~40 ka old (fig. 4). in the outcrops along the walls of the fossa san vito sinkhole, the ci is visible for about 7 metres as a greyish tuff, while in the piedmont area of sarno mts. it is possible to observe its basal pumices layer (fig. 4). in the lavorate area, the boundary between the alluvial fan surfaces and the alluvial plain to the sw is marked by a ~5 m high, nw-se trending and sw facing scarp that is strikingly rectilinear (fig. 3a). topography of the analysed sector of the sarno alluvial plain is smooth and low-lying. it rises rather gradually from the sw to the ne, to maximum values around 25-30 m a.s.l. around the striano and s. valentino torio sector (hereinafter, svt; fig. 3a). this sector is identified as a nw-se trending, smooth topographic high rising of about 5-10 m above the alluvial plain, which is incised transversally by the sarno river (fig. 3a). the svt high limits a relatively nw-se oriented low-lying area, around 2 km in width and 10 km in length (hereinafter named the sarno depocenter; fig. 3a), towards the sw. the eastern boundary of the sarno depocenter is represented by the nw-se trending and sw facing rectilinear scarp at the toe of the alluvial fans in the lavorate area (fig. 3a). the drainage network upstream of the svt is characterised by several anomalies, which suggest that the high-and-low topographic setting of the svt and sarno depocenter affects the surface water flow. for instance, irrespective of the general ne-sw topographic gradient of the alluvial plain, all the tributaries of the sarno river that flow from the mountain front merge into the sarno river upstream of the svt. particularly anomalous is the path of the acqua di san marino streambed. the acqua di san marino streambed is initially characterised by a wandering course while, in the lower part, it bends and gains a nw-se oriented, straight path that is aligned for about 2 km along the northeastern margin of the svt high (fig. 3a and b). 4.2. shallow subsurface setting of the inner sarno plain borehole data from the monti di sarno and lattari mts. piedmont indicate that the deposits of the alluvial fan of the 1st generation consist of poorly cemented to cemented calcareous gravels with abundant pyroclastic matrix, interbedded with sandy layers, cineritic layers and thin palaeosoils. the thickness of these deposits varies along the mountain fronts being ~100 m in the episcopio embayment (borehole b22), ~45 m in the lavorate embayment (borehole b19), ~70 m near pagani (borehole b7) and ~150 m near angri (borehole b32; see fig. 2 for borehole locations), respectively. consistent with evidence from outcrops in the lavorate embayment, deposits of the alluvial fans of the 2nd generation overlie a well-defined 20-30 m thick unit that consists of pyroclastic deposits/tuff, yellowish or the sarno plain recent evolution and post-40 ka faulting greyish in colour, that in some instances pass downwards to a pumice layer. based on its features, such a unit can be correlated with the campania ignimbrite regional chronostratigraphic marker. towards the alluvial plain, the alluvial fan deposits associated with the southern and eastern piedmont areas pass laterally to a succession of deposits composed of alluvial plain to marine sediments alternated with pyroclastic deposits. the upper part of the alluvial plain fill consists of a group of deposits that are composed of poorly cemented sands and gravelly layers and includes an abundant pyroclastic component. information from several boreholes shows that the abovedescribed group of deposits (hereinafter labelled post-ci deposits) postdates deposition of the campania ignimbrite. data from the area spanning from episcopio and lavorate, to the ne, to the svt high, to the sw, indicate that the post-ci deposits in the svt essentially consist of pyroclastic deposits, while the adjacent sarno depocenter is the only sector where the post-ci deposits include fine-grained-lacustrine facies-sediments and peat layers, in the investigated area (fig. 5). in the sarno depocenter the post-ci deposits have a maximum thickness of ~20 m around the municipality of sarno, and also include travertine layers. the spatial distributions of post-ci travertine, peat and lacustrine deposits in the sarno depocenter are shown in the sketches a to f of fig. 5. borehole data have been used for the reconstruction of the top surface of the campania ignimbrite, which is shown in fig. 2. although, due to the uneven spatial distribution of data, a variable degree of uncertainty affects the surface that has been reconstructed, as a general feature the map of fig. 2 shows that the ci top surface declines from the inner margin towards the central part of the sarno plain. such a shape of the ci top surface is substantially consistent with the current morphology of the sarno plain also in the northeastern part of it, where both a localised low in the subsurface of the sarno depocenter, and a slight steepening aligned with the sw-facing scarp located at the ne boundary of that topographic low occur (fig. 2). the top surface of the buried ci plateau is also characterised by elongated lows that can be interpreted as paleovalleys, one of which originates in correspondence of the acqua del palazzo springs and roughly parallels the current path of that stream. another one, with e-w trend, lies below the solofrana river course (fig. 2). 190 fig. 4 late quaternary deposits outcropping along the walls of the fossa san vito sinkhole (a and b) and in the monti di sarno mts. piedmont (c). in diagrams a and b, white lines mark the stratigraphical contact, between the campania ignimbrite (below) and the alluvial and pyroclastics deposits collectively labelled post-c.i. deposits (above). photograph in c shows an outcrop of the campania ignimbrite, with its basal pumice level. valente e. et al. around 20-30 m up to values exceeding 150 m (borehole b69, fig. 2 for location). information from borehole data has been synthesised in two cross-sections (fig. 6), which have been constructed through the alluvial plain and adjoining piedmont areas to the south and ne of the investigated area, respectively, using the deeper available boreholes. the cross-sections highlight either significant lateral variation of thickness of single stratigraphic units, or/and vertical separation between correlative stratigraphic horizons, with both features suggesting vertical displacements along faults. cross section a-a’ strikes from the piedmont area around pagani to the se to the sarno plain to the nw (location in fig. 2). the main quaternary units in this part of the plain include, from the surface: deposits of the alluvial fans of the 2nd generation, which pass laterally into alluvial plain and post-ci pyroclastic deposits; the ci layer; pre-ci deposits with thickness exceeding 70 m; fossiliferous marine-transitional deposits (drilled for at least 40 m towards the end of section a-a’, borehole b11, fig. 6). the lateral distribution of the drilled units suggests that, at depth, the continental environment preci deposits pass towards the nw into transitionalmarine deposits. cross section a-a’ shows the abrupt the deeper boreholes provide information on the lower part of the basin fill. they show that the ci passes downwards to a group of deposits composed of alternated pyroclastic and sandy-gravelly layers, collectively labelled pre-campania ignimbrite (hereinafter pre-ci) deposits, whose maximum thickness locally exceeds 70 m (borehole b3, fig. 2 for location). based on their lithological features, an alluvial plain environment can be hypothesised for the pre-ci sediments. below the pre-ci deposits, an alternation of sand, gravel and silt layers with abundant macrofossils (mostly bivalves), related to marine and transitional environment, occurs. more detailed data from borehole b82 (which corresponds to borehole labelled pozzo sarno in cinque et al., 1987) show that a layer of fluvial-marshy deposits is interposed in the marine deposits at depths from about 45 to 50 m b.s.l. in the piedmont belts, the transitional-marine deposits have been drilled, above the carbonate bedrock, in the subsurface of the lavorate area, whereas the presence of fossiliferous deposits is not reported in borehole logs from the subsurface of the areas around pagani and angri. in the northeastern sector of the investigated area, thickness of the marine-transitional deposits increases abruptly from the lavorate area towards the subsurface of the sarno alluvial plain from 191 fig. 5 schematic maps showing spatial distributions of areas with stratigraphical evidences of lacustrine/marshy environment postdating the campania ignimbrite deposition. a) dashed orange line limits boreholes with travertine layers at 2-5 m of depth (orange dots). b) dashed black line limits boreholes with peat layers at 5-10 m of depth (black dots). c) dashed brown line limits boreholes with travertine layers at 10-12 m of depth (brown dots). d) dashed grey line limits boreholes with peat layers at 15-18 m of depth (grey dots). e) dashed blue line limits boreholes with lacustrine layers at 18-20 m of depth (blue dots). f) superposition of areas sketched in diagrams a to e. yellow dots in each panel indicate boreholes with no either travertine, or peat or lacustrine layers. borehole labels are reported in fig. 2. the sarno plain recent evolution and post-40 ka faulting 192 fig. 6 geological cross-sections within the study area. locations of the cross-section traces are reported in fig. 2. dashed box in crosssection b-b’ indicates the magnification of the fault zone showed to the right of the cross-section. valente e. et al. deepening of the carbonate bedrock towards nw that occurs at two main steps (fig. 6). we associate the carbonate rocks drilled by borehole b7 with the lowered carbonate block that includes the pagani hill (fig. 2), and the first step of the carbonate bedrock with the fault (labelled f1 in cross section a-a’ and fig. 2) that separates the lattari mts. mountain front from the pagani carbonate hill. to the north of fault f1 trace, the base of the pre-ci deposits is lowered down to ~25 m b.s.l. the second step is located to the north of the pagani hill, where the carbonate bedrock deepens down to more than 100 m b.s.l. associated with steps of the carbonate bedrock, are lateral variations of depths of the overlaying, correlative stratigraphic horizons, which suggest displacement along faults. in particular, as the ci layer maintains a substantially constant thickness along the trace of cross section aa’, the vertical separation of both bottom and top of that layer suggests displacement along the inferred fault f2 more than erosion of the ci surface. cross-section b-b’ (fig. 6; location in fig. 2) strikes from the embayment of lavorate to the ne to the sarno plain to the sw. section b-b’ shows that thicknesses of the sedimentary units that lay both below and over the ci increase abruptly substantially in correspondence of the sw-facing scarp located at the northeastern boundary of the sarno depocenter, that we interpret as the surface expression of an extensional fault. in particular, from the subsurface of the piedmont area near lavorate to the subsurface of the sarno depocenter, the section shows: (1) deepening of the carbonate bedrock (from ~50 m to >250 m b.s.l.), (2) an increase of marine deposits thickness (from 25-30 m to at least 175 m) and (3) vertical separation of the pre-ci horizon and of both the base and top of the ci. a rise of both the marine and pre-ci units top surfaces occurs in the subsurface of the svt high, where a slight rise of the ci top also occurs. 5. discussion the low-gradient topography of the entire sarno plain, onto which only the smooth svt high rises, corresponds to the undissected surface of an alluvial plain graded to the present-day coastline. the stratigraphical framework of the shallow subsurface of the inner part of the sarno plain, which is inferred from inspection and correlation of the borehole logs that we have collected, indicates that the environmental conditions have changed from marine to continental through time. furthermore, throughout its recent evolution, the investigated area has been affected by repeated pyroclastic inputs, which represent an important component of all the alluvial units buried in the plain and are interlayered with deposits of the alluvial fans that form the piedmont belts of the monti di sarno and lattari mts. mountain fronts. crucial to the reconstruction of a chronostratigraphical framework for the investigated area is the distinct marker layer that is represented by the c. 40 ka old campania ignimbrite. in the piedmont belts, the presence of the ci underneath coarse grained deposits associated with alluvial fans of the 2nd generation, suggests that the growth of the latter alluvial fans, which can be related to abundant detrital production promoted by frost action, may be correlated, at least in part, with the last glacial period (in agreement with attribution of those alluvial fans to the upper-middle wurm by cinque et al., 1987). as surfaces of the 2nd generation alluvial fans grade to the alluvial plain, we suggest that their deposition continued during the holocene, coeval with aggradation in the alluvial plain (see below). based on relative chronology criteria, an older, middle-upper pleistocene age may be inferred for the growth of the thick alluvial fans of the 1st generation. thicknesses of the latter ones, as inferred from available boreholes, indicate that they deepen in the subsurface down to several tens of metres below the sea level. the lowest quaternary unit drilled by the deeper boreholes from the entire investigated area consists of fossiliferous marine-transitional deposits, which have been recovered down to a depth >250 m b.s.l. these deposits testify to a marine/coastal environment that, during periods of positive sea-level fluctuations, occupied the entire sarno plain to reach its innermost margin, represented by the monti di sarno mountain front. based on information from the trecase 1 well (brocchini et al., 2001), the buried marine-transitional deposits cover the upper part of the middle pleistocene. although age of the top part of the marine unit (that reaches a minimum depth of ~25 m b.s.l.) is not constrained, it can be hypothetically correlated with the last interglacial high sea level. such a correlation is in substantial agreement with attribution to the eutyrrhenian by cinque (1991) and albore-livadie et al. (1990) of marine deposits recovered in the 30 to 40 m b.s.l. depth interval in the subsurface of the sarno plain to the sw of our study area, below a further marine succession (located from ~ 10 to 20 m b.s.l.) constrained to the holocene sea-level rise by geochronological and geoarcheological data. in the entire investigated area, the marinetransitional deposits are covered by alluvial sediments, which are interlayered with pyroclastic deposits. based on chronostratigraphical correlation, within the alluvial deposits, we have distinguished a >40 ka pre-ci unit, and a post-ci unit. between these units, the ci forms a ~ 20 to 30 m thick, distinctive layer. deposition of the ci occurred at a time when the sea level was ~80 m lower than at present (e.g. siddall et al., 2005), and the sarno plain was entirely located above the sea level (milia, 1998; 2000). cinque & irollo (2004) related the incision by the sarno river, in the ci layer, of a valley down to -30 m a.s.l. in the soutwestern part of the sarno plain (pompei area) to the further lowering of the sea level down to -120 m in the last glacial maximum (e.g. siddall et al., 2005). we correlate to the same lgm incision phase the formation of the valleys that we have identified in the inner part of the sarno plain, where they reach depths >5 m b.s.l. (fig. 2). more in general, we hypothesise that in response to the instantaneous deposition of a 20-30 m thick layer combined with sea level lowering, fluvial dynamics in the study area in the 40-20 ka time span was dominated by fluvial downcutting. within such a scenario, alluvial deposition was essentially limited to the piedmont belts and coeval aggradation in the quasi-flat plain mostly related to pyroclastic 193 the sarno plain recent evolution and post-40 ka faulting inputs by the somma-vesuvius and, to a minor extent, phlegrean fields. most probably, alluvial aggradation in the study area mostly occurred during the late part of the holocene, when the sea level rise led to a transgression in the southwestern part of the sarno plain up to a distance of ~8 km from the present-day coastline (e.g., albore livadie et al., 1990; cinque, 1991). overall, detailed chronostratigraphical and geochronological information from the central-coastal area of the sarno plain, which highlights the occurrence of the buried holocene coastal wedge at few tens of metres below the sea level, points to quaternary subsidence continuing during the holocene (e.g., cinque et al., 1987; barra et al., 1989; albore livadie et al., 1990). on the other hand, holocene coastal progradation and alluvial plain aggradation point to sediment accumulation outpacing coeval subsidence. based on stratigraphical data, such an unbalance may be explained as the response to the emplacement of abundant pyroclastic products, which has taken place mostly since the late pleistocene. the geomorphological and stratigraphical analyses that we have carried out provides new information on the possible locations of some of the faults which controlled the recent vertical motions of the sarno plain, particularly at the southern and northern boundaries of the inner part of the plain. in particular, the geomorphological analysis combined with the subsurface data analysis has allowed identification of features that are consistent with vertical, fault-related, displacement affecting both the topographic surface and underlying buried bodies. combined evidence has allowed constraining location of the major fault, which bounds the lattari mts. mountain front (fault f1 in cross-section aa’, which separates carbonates of the lattari mts. ridge from those of the pagani hill block) and suggests possible displacement along a further fault (fault f2) located to the north of it. worthy to note, late quaternary subsidence of the sector to the north of the lattari mts. mountain front located to the east of the area investigated with our study, i.e. the region which corresponds to the solofrana river valley and includes the carbonate elevations that rise above the plain, has been inferred by brancaccio et al. (1994) from subsurface data. the presence of a fault (fault f3 in fig. 2 and cross section b-b’) at the southwestern border of the monti di sarno mts. ridge is inferred from the presence in the lavorate area of a ~5 m high, sw-facing scarp, which substantially follows a step in the buried ci top surface. the vertical separation among buried, correlative horizons shown in cross-section b-b’ is consistent with interpretation of the nw-se trending lavorate scarp as a fault scarp representing the surface expression of fault f3. for both f2 and f3, information from the cross sections in fig. 6 is consistent with displacement of the preci deposits and underlying marine-transitional deposits, as well as the campania ignimbrite layer. the increase of vertical separation from the upper to lower boundaries of the pre-ci unit suggests syn-sedimentary fault activity. the geomorphological analysis has allowed the identification, to the southwest of the f3 fault scarp, of the sarno depocenter topographic low, which is limited towards the sw by svt high. towards the ne, the svt is bounded by a straight scarp that can be interpreted as a fault scarp associated with the inferred fault f4, in agreement with cinque et al. (2000). consistent with features of topography, the vertical separation that characterises both the ci and underlying quaternary units across the traces of the inferred faults f3 and f4 is compatible with fault activity causing lowering of the sarno depocenter. in the sarno depocenter, holocene ponding is inferred from the accumulation of travertine, peat and fine-grained deposits in a marshy/lacustrine environment (fig. 5) that postdates deep incision (related with the lgm sea-level lowering) of the ci. such a ponding may be related to either tilting or/and lowering of the sarno depocenter surface during the latest pleistoceneholocene. the analysis of the hydrographic network, which is very sensitive to differential motions of the topographic surface (schumm et al., 2002; ascione et al., 2007) provides evidence for vertical motions of the svt based on inconsistency of drainage orientations (e.g. acqua di san marino stream) with respect to the largescale gradient. in addition, merging of streams originating from the monti di sarno mountain front upstream of the svt high suggests that minor streams, with relatively low discharge and stream power, have been substantially incapable of dissecting the morphological high itself. overall evidence suggests antecedence of the stream network relative to the svt. a very recent rise of the svt may also explain the anomalous bending, and straight (nw-se oriented) path of the acqua di san marino stream, which is compatible with displacements along the inferred fault f4 affecting the topographic surface and the sensitive fluvial system. the geomorphological and geometrical settings that we have reconstructed may be justified by faults slipping at a relatively low rate. in particular, by correlation with the mis5 of the uppermost marine deposits, a mean vertical motion rate in the last ~125 ka of less than 0.3 mm/yr may be inferred for faults f2, f3 and f4 from the vertical separation of the marine unit top, while a decrease to less than 0.2 mm/yr and even less than 0.1 mm/yr in the last 40 ka for faults f3 and f4, respectively, may be inferred if the campania ignimbrite marker is taken as a reference. geomorphic and stratigraphic evidence from the boundaries of the sarno depocenter suggests that slip along faults f3 and f4 has continued during the holocene, while the lack of offset landforms associated with fault f2 at the base of the lattari mts. may suggest either substantial quiescence of this fault since the late holocene, or faulting at a rate slower than that of accumulation of the sediments in the piedmont of the lattari mts. the around 30 m b.s.l. depth of the top of the late quaternary marine deposits in the footwall block of fault f3 indicates that the lavorate embayment, as well as the plain in front of it, have been subject to subsidence during the final part of the late quaternary. such evidence implies that a more articulated fault system along the north-eastern boundary of the sarno plain has controlled the late quaternary subsidence of the southeasternmost sector of the campania plain as well as the 194 valente e. et al. 195 contiguous sector, which includes the solofrana river valley and adjacent carbonate hills. lowering of the f3 footwall block could be related to some fault strand possibly represented by the inferred fault with orientation around e-w, located along the northern boundary of the lavorate area (fig. 3a), the recent activity of which could not be constrained by our data sets. 6. concluding remarks the combination of detailed geomorphological analysis and reinterpretation of stratigraphical data from 80 boreholes has allowed to constrain the geomorphological and geological evolution of the inner part of the sarno plain, contributing to the reconstruction of the late quaternary evolution of the southern part of the campania plain quaternary coastal graben. our results are consistent with former findings by e.g., albore livadie et al. (1990) and cinque (1991) in the outer, southwestern part of the sarno plain, and by brancaccio et al. (1994) in the solofrana river valley and adjacent elevations. collectively, such data point to quaternary subsidence of the southern part of the campania plain continuing after the late pleistocene. within such a scenario, the ultimate evolution from marine to continental environment recorded in the inner part of the sarno plain following the last interglacial has been essentially controlled by high sedimentation rate, which received a substantial contribution by the emplacement of abundant pyroclastic inputs by both the phlegrean fields and somma-vesuvius. although the perimeter of the subsiding region could not be entirely constrained by our data sets, the evidence that we have provided for recent displacements at the north-eastern boundary of the sarno plain supports the hypothesis of active fault strands along the monti di sarno mts. mountain front, inferred by santo et al. (2011) and ascione et al. (2014) from the presence of features such as mineral springs, sinkholes and tufa/ travertine deposits, which are indicators of leakage of fluids along active fault. the post-40 ka vertical motion along faults with nw-se and e-w trends that we have identified at the boundaries of the inner sector of sarno plain are consistent with findings by irollo et al. (2005) of holocene vertical displacements along the western strands of the fault system at the southern boundary of the sarno plain. overall information suggests that the inferred fault strands f2, f3 and f4 may be considered as active faults. in addition, the values of mean vertical displacement that we have inferred for faults f2, f3 and f4 are comparable with slip rate values of faults that, in the southern apennines region, show evidence of activity since the upper pleistocene (e.g., cinque et al., 2000, and references therein). taking into consideration the important implications of our findings on the geological hazard of the densely populated sarno plain area, the area that we have investigated appears worthy of further in-depth investigations aimed at constraining the geometry and late activity of the identified faults. acknowledgements we wish to thank editor paolo mozzi and the two reviewers, domenico capolongo and biagio giaccio, for thoughtful and constructive criticism, which helped us improving our work. references albore-livadie c., barra d., bonaduce g., brancaccio l., cinque a., ortolani f., pagliuca s., russo f. (1990) evoluzione geomorfologica, neotettonica e vulcanica della piana costiera del fiume sarno (campania) in relazione agli insediamenti anteriori all'eruzione del 79 d.c. in: volcanologie et archeologie (albore livadie c. & widemann f. eds.), pact, consiglio d’europa, 25, 237-256. alessio m., bella f., improta s., belluomini g., calderoni g., cortesi c., turi b. (1974) university of rome carbon-14 dates xii. radiocarbon, 16(3), 358-367 amato v., aucelli p.p.c., cesarano m., jicha b., lebreton v., orain r., pappone g., petrosino p., russo-ermolli e. (2014) quaternary evolution of the largest intermontane basin of the molise apennine (central-southern italy). rendiconti fisici dell’accademia dei lincei, 25, 197-216. amato v., aucelli p.p.c., bellucci sessa e., cesarano m., incontri p., pappone g., valente e., vilardo g. (2017) multidisciplinary approach for fault detection: integration of ps-insar, geomorphological, stratigraphic and structural data in the venafro intermontane basin (central-southern apennines, italy). geomorphology, 283, 80-101. aprile f., toccaceli r.m. (2002) new knowledge about stratigraphy and the distribution of quaternary ignimbrite deposits in the subsurface of the sarno plain (salerno-campania, southern italy). il quaternario, 15(2), 169-174. ascione a., cinque a. (2003) le variazioni geomorfologiche indotte dalla tettonica recente in appennino meridionale. il quaternario, 16(1), 139-146. ascione a., caiazzo c., cinque a. (2008) recent faulting in southern apennines (italy): geomorphic evidence, spatial distribution and implications for rates of activity. bollettino della società geologica italiana, 126(2), 293-305. ascione a., iannace a., imbriale p., santangelo n., santo a. (2014) tufa and travertines of southern italy: deep-seated, fault related co2 as the key control in precipitation. terra nova, 26, 1-13. ascione a., ciotoli g., bigi s., buscher j., mazzoli s., ruggiero l., sciarra a., tartarello m., valente e. (2018) assessing mantle versus crustal sources for non-volcanic degassing along fault zones in the actively extending southern apennines mountain belt (italy). geological society of america bulletin, 130(9-10), 1697-1722. aucelli p.p.c., amato v., budillon f., senatore m.r., amodio s., d’amico c., da prato s., ferraro l., pappone g., russo ermolli e. (2012) evolution of the sele river coastal plain (southern italy) during the late quaternary by inland and offshore stratigraphical data. rendiconti fisici dell’accademia the sarno plain recent evolution and post-40 ka faulting 196 dei lincei, 23, 81-102. balducci s., vaselli g., verdiani g. (1983) exploration well in the ottaviano permit, italy, trecase 1. european geothermal update, 3rd international seminary, munich, germany, 407-418. barra d., bonaduce g., brancaccio l., cinque a., ortolani f., pagliuca s., russo f. (1989) holocene geological evolution of sarno river coastal plain (campania). memorie della società geologica italiana, 42, 255-267. bernasconi a., bruni p., gorla l., principe c., sbrana a. (1981) preliminary results of deep geothermal exploration in the somma-vesuvius volcanic area. rendiconti della società geologica italiana, 4, 237 -240. brancaccio l., cinque a., romano p., rosskopf c., russo f., santangelo n., santo a. (1991) geomorphology and neotectonic evolution of a sector of the tyrrhenian flank of the southern apennines (region of naples, italy). zeitschrift für geomorphologie, suppl. 82, 47-58. brancaccio, l., fiume, g., grimaldi, m., rapolla, a., romano, p. (1994) analisi gravimetriche nella bassa valle del torrente solofrana (sa) e considerazioni sulla sua evoluzione quaternaria. geografia fisica e dinamica quaternaria 17, 131-137. brancaccio l., cinque a., romano p., rosskopf c., russo f., santangelo n. (1995) the evolution of campania coastal plains: geomorpholy and neotectonics. memorie della società geografica italiana, 53, 313-337. brocchini d., principe c., castradori d., laurenzi m.a., gorla l. (2001) quaternary evolution of the southern sector of the campania plain and early somma-vesuvius activity: insights from the trecase 1 well. mineralogy and petrology, 73, 67-91. buscher j., ascione a., valente e. (2017) decoding the role of tectonics, incision and lithology on drainage divide migration in the mt. alpi region, southern apennines, italy. geomorphology, 276, 37-50. caiazzo c., ascione a., cinque a. (2006) late tertiary -quaternary tectonics of the southern apennines (italy): new evidences from the tyrrhenian slope. tectonophysics 421, 23-51. cella f, fedi m., florio g., grimaldi m., rapolla a. (2007) shallow structure of the somma-vesuvius volcano from 3d inversion of gravity data. journal of volcanology and geothermal research, 161, 303-317. cello g., mazzoli s. (1999) apennine tectonics in southern italy: a review. journal of geodynamics, 27, 191-211. cinque a. (1991) la trasgressione versiliana nella piana del sarno (campania). geografia fisica e dinamica quaternaria, 14, 63-71. cinque a., russo f. (1986) la linea di costa del 79 d.c. fra oplonti e stabiae nel quadro dell’evoluzione olocenica della piana del sarno (campania). bollettino della società geologica italiana, 105, 111-121. cinque a., hossen h., laureti l., russo f. (1987) osservazioni preliminari sull’evoluzione geomorfologica della piana del sarno (campania, appennino meridionale). geografia fisica e dinamica quaternaria, 10, 161-174. cinque a., patacca e., scandone p., tozzi m. (1993) quaternary kinematic evolution of the southern apennines. relationships between surface geological features and deep lithospheric structures. annals of geophysics. 36(2), 249-259. cinque a., ascione a., caiazzo c. (2000) distribuzione spazio-temporale e caratterizzazione della fagliazione quaternaria in appennino meridionale. in: galadini f. (ed.), le ricerche del gndt nel campo della pericolosita` sismica, 203-218, cnr-gndt, rome. cinque a., irollo g. (2004) il “vulcano di pompei”: nuovi dati geomorfologici e stratigrafici, il quaternario. 17(1), 101-116. de alteriis g., fedi m., passaro s., siniscalchi a. (2006) magneto-seismic interpretation of subsurface volcanism in the gaeta gulf (italy, tyrrhenian sea). annals of geophysics, 49, 929-943. de vivo b., rolandi g., gans p.b., calvert a., bohrson w.a., spera f.j., belkin h.e. (2001) new constraints on the pyroclastic eruptive history of the campanian volcanic plain (italy). mineralogy and petrology,73(1-3), 47-65. doglioni c., innocenti f., morellato c., procaccianti d., scrocca d. (2004) on the tyrrhenian sea opening. memorie descrittive della carta geologica d’italia, 64, 147-164. giaccio b., hajdas i., isaia r., deino a., nomade s. (2017) high-precision 14c and 40ar/39ar dating of the campanian ignimbrite (y-5) reconciles the time-scales of climatic-cultural processes at 40 ka. scientific reports, 7, 45940. guarino p.m., nisio s. (2009) i sinkholes del settore nord-orientale della piana del f. sarno: ulteriori dati relativi all’assetto litostratigrafico del sottosuolo. atti 2° workshop internazionale “i sinkholes. gli sprofondamenti catastrofici nell’ambiente naturale ed in quello antropizzato”, rome, italy, ispraservizio geologico d’italia, 541-551. irollo g., ascione a., cinque a. (2005) holocene tectonic activity along two fault zones in the gulf of napoli. in: slejko d. e rebez a. (eds.), gruppo nazionale di geofisica della terra solida, 24° convegno nazionale, riassunti estesi delle comunicazioni, roma, 17-21. ispra (2014a) sheet 448-ercolano at scale 1:50000, carg project (http://www.isprambiente.gov.it/ media/carg/448_ercolano/foglio.html) ispra (2014b) -sheet 466-sorrento at scale 1:50000, carg project (http://www.isprambiente.gov.it/ media/carg/466_485_sorrento_termini/ foglio.html) malinverno a., ryan w.b. (1986) extension in the tyrrhenian sea and shortening in the apennines as result of arc migration driven by sinking of the lithosphere. tectonics, 5(2), 227-245. mazzoli s., helman m. (1994) neogene patterns of relative plate motion for africa-europe: some impli valente e. et al. 197 cations for recent central mediterranean tectonics. geologische rundschau, 83, 464-468. milia a. (1998) late quaternary pyroclastic units in the gulf of naples. geografia fisica e dinamica quaternaria, 21, 147-153. milia a. (2000) the dohrn canyon formation: a response to the eustatic fall and tectonic uplift of the outer shelf (eastern tyrrhenian sea margin, italy). geo-marine letters, 20, 101-108. milia a., torrente m.m., massa b., iannace p. (2013) progressive changes in rifting directions in the campania margin (italy): new constrains for the tyrrhenian sea opening. global and planetary change, 109, 3-17. milia a., torrente m.m. (2015) tectono-stratigraphic signature of a rapid multistage subsiding rift basin in the tyrrhenian-apennine hinge zone (italy): a possible interaction of upper plate with subducting slab. journal of geodynamics, 86, 42-60. misuraca m., budillon f., tonielli r., di martino g., innangi s., ferraro l. (2018) coastal evolution, hydrothermal migration pathways and soft deformation along the campania continental shelf (southern tyrrhenian sea): insights from highresolution seismic profiles. geosciences, 8(4), 121. morano d. (1882) intorno alla dinamica delle acqua della foce ed al canale di sarno. stabilimento tipografico di v. morano, napoli, pp. 203. nicotera p., civita m. (1969) indagini idrogeologiche per la captazione delle sorgenti s. maria di lavorate (sarno). memorie e note dell’istituto di geologia applicata dell’università di napoli, 11, 1-50. patacca e., sartori r., scandone p. (1990) tyrrhenian basin and apenninic arcs kinematic relations since late tortonian times. memorie della società geologica italiana, 45, 425-451. rolandi g., bellucci f., heizler m., belkin h.e., de vivo b. (2003) tectonic controls on the genesis of the ignimbrites from campania volcanic zone, southern italy. mineralogy and petrology, 79, 3-31. rovida a., locati m., camassi r., lolli b. gasperini p. (2016) cpti15, the 2015 version of the parametric catalogue of italian earthquakes. istituto nazionale di geofisica e vulcanologia. doi: 10.6092/ingv.it-cpti15. russo ermolli e., aucelli p.p.c., di rollo a., mattei m., petrosino p., porreca m., rosskopf c.m. (2010) an integrated stratigraphical approach to the late middle pleistocene succession of the sessano lacustrine basin (molise, italy). quaternary international, 225, 114-127. santangelo n, romano, p., ascione, a., russo ermolli, e. (2017) quaternary evolution of the southern apennines coastal plains: a review. geologica carpathica, 68(1), 43-56. santo a., ascione a., del prete s., di crescenzo g., santangelo n. (2011) collapse sinkholes distribution in the carbonate massifs of central and southern apennines. acta carsologica, 40, 95112. santo a., santangelo n., de falco m., forte g., valente e. (2019) sinkholes in alluvial plain: the prehistoric case study of “fossa san vito” (sarno-southern italy). geomorphology, 345, 106838. sartori r. (1990) the main results of odp leg 107 in the frame of neogene to recent geology of the perityrrhenian areas. in: kastens a. & mascle k.j. et al. (eds.), proceedings of odp, scientific results 107, college station, tx (ocean drilling program), 715-730. sartori r. (2003) the tyrrhenian backarc basin and subduction of the ionian lithosphere. episodes, 26, 217-221. schumm s.a., dumont j.f., holbrook j.m. (2002) active tectonics and alluvial rivers. cambridge university press. siddall m., rohling e.j., almogi-labin a., hemleben c., melschner d., schmelzer i., smeed d.a. (2003) sea-level fluctuations during the last glacial cycle. nature, 423, 853-858. tramparulo f.d.a., vitale s., isaia r., tadini a., bisson m., prinzi e.p. (2018) relation between alternating open/closed-conduit conditions and deformation patterns: an example from the sommavesuvius volcano (southern italy). journal of structural geology, 112, 138-153. the sarno plain recent evolution and post-40 ka faulting ms. received: may 7, 2019 final text received: november 3, 2019 198 amq_27(2) def 16 b available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 27 (2), 2014, 85 104 glacial and proglacial deposits of the resia valley (ne italy): new insights on the onset and decay of the last alpine glacial maximum in the julian alps. renato r. colucci1, giovanni monegato2, manja žebre1,3 1 c.n.r. institute of marine sciences, trieste, italy 2 c.n.r. institute of geosciences and earth resources, torino, italy 3 department of geography, faculty of arts, university of ljubljana, ljubljana, slovenia corresponding author: g. monegato <g.monegato@csg.to.cnr.it> abstract: the resia valley is located in the south-eastern sector of the alps, where small glacial remnants are still preserved despite the average low-elevation of the reliefs. the abundance of glacigenic deposits related to the last glacial maximum allowed to discuss and reconstruct the onset and decay of the glaciation. the initial glacier expansion from the canin-toudule and the barman cirques led to the infilling of the former valley with fluvioglacial and glaciolacustrine successions. then, the spread of the resia glacier during the lgm climax covered and over-consolidated these units. on the valley flanks, the interaction of the base of the trunk glacier with the sharp preglacial topography caused the formation of subglacial deposits containing large-size sub-angular boulders and glaciolacustrine fines. during the lgm the resia glacier reached the maximum thickness of about 550 m, and was tributary of the fella glacier at resiutta. during the late glacial, two main stadial phases are characterised by frontal moraines and ice-dammed deposits. in the first, glacier streams flowed down only from the resartico and barman valleys, damming the trunk valley; this caused the formation of lakes and the aggradation of the outwash deposits related to the glaciers located in the upper valley. in the second stadial phase, glaciers were confined in highelevation accumulation areas. nevertheless, the barman and canin-toudule ice streams reached the base of the slope, due to the peculiar climatological setting. in fact, the accumulation area is in one of the highest precipitation rate sector of the alps (present map > 3000 mm). these climatological characteristics allow the preservation of very small glaciers, glacierets and firn-patches at about 2300 m a.s.l. even under the present, warmer climate. keywords: glacial deposits, paleoglaciology, geomorphology, lidar dem, last glacial maximum, se alps. 1. introduction the south-eastern sector of the alps (namely carnic and julian alps) was characterised by a considerable extensive glaciation during the last glacial maximum (van husen, 1987; ehlers & gibbard, 2004; vai & cantelli, 2004; monegato et al., 2007; carton et al., 2009; bavec & verbi�, 2011) and even today some small glaciers and glacierets are still present at the lowest altitude (between 1830 and 2340 m a.s.l.) of the entire mountain chain (serandrei barbero et al., 1989; carturan et al., 2013; colucci & guglielmin, 2014). in the southern part, at the boundary between the julian prealps and the northern dinarides, several small cirque glaciers related to the last glaciation were recognised (monegato, 2012; žebre et al., 2014); they indicated a very low equilibrium line altitude (ela) during the last glacial maximum pointing to a very humid condition and, hence, enhanced the precipitation rates as marked also by pollen records (pini et al., 2010). the preservation of a large end-moraine system at the outlet of the tagliamento valley (fig. 1) led to the recognition of distinct advance pulses and glacier stabilisation phases during the last glaciation (monegato et al., 2007; fontana et al., 2014). however, the sedimentary evidence of the onset and decay of the lgm is very scarce in the mountain basins (venturini, 2003; bavec et al., 2004), even though the presence of glacial deposits is widespread and has been mostly related to the climax and decay of the last glaciation. the resia valley (julian alps and prealps), a major tributary in the fella catchment, contains thick remnants of glacigenic deposits; some of these were already ascribed to pre-würmian glacial advances (desio, 1926), but mostly related to the last glaciation and its decay (zanferrari et al., 2013). the present paper is aimed at depicting glacigenic deposits of the resia valley and its geomorphological evolution from the onset of the lgm to the present day. sedimentological and stratigraphic analyses coupled with lidar data examinations cast a new light on the glacier development and decay in this sector of the alps. in addition, considerations about the past and future development of accumulation areas in this boundary sector of the alps are provided. 2. geological and geomorphological setting the resia river basin (fig. 1) is 105 km2 wide and is located at the boundary between the julian alps and prealps, in the south-eastern sector of the alpine chain close to the boundary with the northern dinarides. the julian alps are characterised by carbonate massifs, reaching the highest elevations in the mount triglav (2864 m a.s.l.) in the slovenian side, and the mount montasio (2754 m a.s.l.) in the italian side. the water divide between the adriatic sea and the black sea crosses the range of the mount canin (2587 m a.s.l.). its western side represents the headwall of the resia valley (fig. 1). the bedrock is made up of upper triassic carbonate succession, mainly dolostones (dolomia principale) and limestones (dachstein limestone), with carnian red clay and gypsum (travenanzes fm.) cropping out along the valley (carulli, 2006; zanferrari et al., fig. 1 location of the resia valley in the eastern southern alps. the dashed line represents the border between italy to the left and slovenia to the right. 2013). jurassic to cretaceous limestones, marly limestones and flysch crop out in the barman valley, a left tributary of resia located in the julian prealps (fig. 2). here, the general northward dip-slope of the strata of about 55° is marked by the presence of well-exposed bed plains along the northern side of the mount musi. the resia valley is crossed by several faults related to the idrija strike-slip system showing a wnw-ese direction. these faults split the carbonate succession in slices and produce a sector of thick cataclastic deposits, that are partly inherited from the dinaric phase of the alpine orogenesis (zanferrari et al., 2013 and refs. therein). the geological and structural framework influenced the morphology of the resia valley, about 20 km long, whose direction follows that of the resiutta fault of the idrija system (zanferrari et al., 2013). also the main ridge of the mount musi and plauris-lavara (julian prealps), as well as the northwestern ridge of the mount canin have a direction inherited from this setting. however, the deep canyons of barman and nero creeks have a n-s direction. the northwestern ridge of the mount canin is flat and includes the mount posar (948 m a.s.l.) and the mount plagna (853 m a.s.l.); it separates the resia valley from the lower raccolana and the fella valleys (fig. 1). the upper valley is characterised by the steep western wall of the mount canin, even if the true head has lower elevation ending at ~1640 m a.s.l. the latter also represents the water divide with the so�a/isonzo catchment, reaching even lower altitudes at carnizza saddle (1086 m a.s.l.) in the upper barman valley. the quaternary successions are widespread along the valley, and have been reported since the late 19th century (taramelli, 1875; brückner, 1891; tellini, 1891). a more detailed description was provided by desio (1926), who recognised the presence of prewürmian successions at gniva, oseacco and coritis. 86 colucci r. r. et al. 87 fig. 2 contour dem of the resia valley with the distribution of the major sedimentary bodies. in black frames the area investigated in detail: fig. 4: upper resia valley; fig.6: barman/resia junction and terraces; fig. 7: outlet of the valley at resiutta. glacial and proglacial deposits of the resia valley (ne italy): new insights of the alpine lgm the same author gave a description of the glacial deposits related to the würmian and to the following icedecay. he highlighted the presence of “exotic” boulders from the carnic alps in the upper resia valley. he related these findings to glacial transfluence from the fella catchment, but this would implied anomalous flow of the glacier streams. a synthesis was reported in the official geological map of italy at the scale 1:100.000 (gortani & desio, 1925) that evidenced the abundance of deposits along the valley floor, but very scarce patches of glacial deposits on the flat northern divide. later investigations documented the presence of deformation in the lacustrine deposits at oseacco and coritis (vaia & zorzin, 1981; cavallin & martinis, 1985) tentatively ascribed to neotectonics, as well as the presence of older valley outlets at different elevations, evidenced in recent studies (battello & vaia, 1999; zanferrari et al., 2013). 3. climatological settings the area of the julian prealps is known for being a region of heavy precipitation in the alps where particularly large annual mean values are observed (isotta et al., 2014). the 1981-2010 mean annual precipitation (map) shows a peak of 3335 mm on the canin massif at 2200 m a.s.l., (colucci & guglielmin, 2014), representing one of the highest mean values for the alps and europe (gregorcic et al., 2001; norbiato et al., 2007). in the valley bottom the 1961-2000 map of resia (380 m a.s.l.) and oseacco (490 m a.s.l.) is equal to 2458 mm and 2620 mm respectively, while in the village of musi (635 m a.s.l.), slightly southern of mt. musi (1866 m), is equal to 3035 mm (open access data osmer-arpa fvg). snow is also very abundant in the area, especially over the canin massif with a mean winter snow accumulation of 7.0 m at 1830 m a.s.l.. available data for coritis (641 m a.s.l.) shows a 2001-2013 mean annual air temperature (maat) of 9.8±0.6°c (open access data osmer-arpa fvg). the 1981-2010 maat for the mt. canin (at 2200 m a.s.l.) has been recently estimated in 1.1±0.6°c (colucci & guglielmin, 2014). these peculiar climatological characteristics still allow the existence of some very small glaciers (sensu kuhn, 1995), glacierets and ice patches at very low altitudes on the northern side of mt. canin, developing between 1830 and 2340 m a.s.l.. also on the sunny-southern slopes in the resia valley, at highest elevation, some snow patches persist till the end of the ablation season in some years giving indications about how the onset of a glaciation might develop in the resia valley. this is particularly evident in the toudule cirque (fig. 3). the avalanche activity plays of course an important role, mainly owing to the topography of the northwestern slopes in the orographic left of this cirque. the widespread avalanche activity is aided by the presence of several gullies able to drive and canalize avalanches practically during and after any snow event. this leads to the accumulation of large snow masses at the base of the rockwalls often able to counteract the summer heat. this is also facilitated by the higher shading thanks to the north-westerly aspect. since the end of the little ice age (lia) both maat and mean summer air temperature in the canin area, reconstructed at 2200 m a.s.l., have risen of about 1.5°c showing an accelerated trend in the last 2 decades. during the 1970s and 1980s there is evidence of a higher frequency of snow-ice fields remnants, supported by private photographic material and personal communications given by the local population and the park authorities. these fact lead to conclude that during the lia some permanent ice field or even very small avalanche-fed glacier or glacieret could have been existed, in a time when the canin glaciers were covering an area of about 1.2 km2 instead of the current 0.2 km2 (colucci & guglielmin, 2014). other potential areas for the formation of glaciers are identifiable in the north-facing slopes of the resartico and barman valleys, below the mount musi and mount plauris (fig. 2), where widespread snow fields recently survived at the 2009 and 2014 summer heats. 4. methods the stratigraphy of the sedimentary units is established using the allostratigraphic approach (nascn, 1983); outcrop description was performed and synthe 88 fig. 3 the toudule cirque in september 2006 (ortophoto, left) and in august 2014 (oblique view, right), respectively after an “average” and “above average” precipitation winter season. colucci r. r. et al. 89 sised using fluvial (miall, 1996) and glacial (eyles et al., 1983) facies codes. the geomorphological map was obtained not only from fieldwork mapping, but also from geological maps (geological sheet 049 “gemona del friuli” at the scale 1:50.000; zanferrari et al., 2013) and geographic information system (gis) analysis of orthophoto and lidar data. the resia valley area was surveyed by airborne laser scanning between 2009 and 2010 by the civil defense of fvg using a lidar system optech altm 3033 having laser frequency of 33 khz and a laser wavelength of 1047 nm. the minimum point density is 4 point m-2, and the relative horizontal and vertical accuracies are better than 1 m and 0.3 m, respectively. the acquisition mode picked up simultaneously the first and the last pulse and the intensity, particularly important in forested areas. each survey has been performed in late summer and early autumn, when no fresh snow was present on the ground, with exception of some very small patches at the highest altitudes (fig. 3). this is clearly visible also from high resolution (0.15 m px-1) aerial photographs acquired during the flights, and even used for the identification of geomorphological features. a digital elevation model (dem) having posting of 1 m px-1 has been obtained, and an extensive use of shaded reliefs derived from the dems (hillshade) for helping the identification of the past glacial features has been made. the equilibrium-line altitude (ela) was determined by applying the accumulation-area ratio (aar) method. the aar method requires a contoured map of the former glacier surface and the ratio of the glacier’s accumulation area to the sum of its accumulation and ablation areas (benn & lehmkuhl, 2000; porter, 2001). well preserved frontal moraines and evident accumulation area allow the accurate reconstruction of the glacier surface and thus the calculation of the ela only for the barman glacier. although the average aar for the glaciers in the european alps was found to be 0.67 (gross et al., 1976), in this study lower aars were used for the ela calculation due to the assumed debris cover and avalanching effect. 5. geomorphology of the resia valley the upper resia valley is characterised by the presence of a cirque complex (fig. 4), having a role of accumulation area in the past. the majority of cirques are not well-developed and are characterised by a widespread system of gullies and incisions. their present morphology is prone to avalanche activity, being especially high on the south exposures, where very steep slopes, exceeding even 60 degrees, are common. on the north-westernmost part a widely extended plateau between the sart (2324 m a.s.l) and grubia (2238 m a.s.l.) peaks, reaching the lowest altitudes at ~1500 m, separates the laschi cirque from that of ronc (fig. 4). in both cirques no clear evidence of moraine deposits can be recognized probably owing to steep slopes and high avalanche reworking. the laschi cirque is completely and deeply dissected by gullies, meanwhile the ronc cirque is the largest and most welldeveloped cirque in the upper resia valley (fig. 4) the latter is also the highest cirque, reaching the top of the headwall in the peak of canin (2587 m a.s.l.). here, avalanches can start from an elevation up to 2400 m, following the path of the ronc creek and reaching even fig. 4 geomorphological map and 3d lidar image of the upper valley. the yellow arrow indicates the narrow gorge of the resia river downstream the terraces; 1: hudaraven moraine; 2: coritis moraine. glacial and proglacial deposits of the resia valley (ne italy): new insights of the alpine lgm the valley bottom at ~600-700 m a.s.l. at the outlet of the ronc valley, on the orographic left, a 130 m long and ~25 m high moraine ridge (fig. 4), interpreted as the lateral moraine of the ronc glacier, is present on the fluvial terrace at 625 m a.s.l.. glacial deposits on the orographic right are scattered along the slope between 610 and 830 m a.s.l. here, only one moraine ridge between 755 and 830 m a.s.l. can be distinguished. south of the ronc cirque the 0.3 km wide and 1.5 km long secco cirque-like feature is present, extending between 1350 and 2570 m a.s.l. it ends with two lateral moraines ~320 m long. below the secco cirque, more than 200 m high cliff leads to the secco valley, that reaches the confluence with the resia river at 565 m a.s.l. (fig. 4). two evident ridges are present on both left and right fluvial terraces, extending up to 65 m above the present resia riverbed. neither one of those two ridges is interpreted as belonging to the glacier coming from the secco cirque due to its small accumulation area (fig. 4). the moraine ridge to the right, at hudaraven (1 in fig. 4; fig. 5b) probably belongs to the glacier coming from the ronc valley (as already discussed), meanwhile the moraine of coritis (2 in fig. 4), located between 650 and 690 m a.s.l., is interpreted as a right lateral moraine of a trunk glacier coming from innermost sector of the valley. further to the south-east another narrow, but relatively well-developed and nesw elongated cirque, named the toudule cirque, is present between the canin (2587 m a.s.l.) and cerni vogu (2415 m a.s.l.) peaks. on the orographic left, at the base of its north-west and west slopes, there is evidence of the only semi-permanent snow patches in the resia valley at about 1900 m a.s.l., still existing with the present climatological conditions (fig. 3) and related to avalanche feeding. this phenomenon is of great importance, since we can assume that during the glacial phases this glacier cirque was among the most active in the area. moraine deposits coming from the toudule cirque are preserved up to 80 m above the present toudule valley bottom, where avalanche activity is absent. they appear in the form of both, right and left (fig. 4) lateral moraines, extending between 820 and 1000 m a.s.l. between the mt. lasca plagna (2448 m a.s.l.) and mt. baba grande (2160 m a.s.l.), another former glacial accumulation area is present, although missing the typical cirque morphology. like the majority of the cirques in the study area, also this one is characterised by a high 90 fig. 5 a) the upper cirque at malga coot with moraines related to the late glacial. b) the hudaraven moraine at the outlet of the ronc colucci r. r. et al. 91 avalanche activity. evident lateral moraines occur below the cirque at 1300 m a.s.l. the right one is at least at two sides breached by avalanche tracks coming from the steep south-facing slopes below the mt. lasca plagna. the left lateral moraine is dissected by small streams, thus its morphology is preserved only in the upperand lower-most part. both orographic left and right lateral moraines end at ~900 m a.s.l. the lowest cirque in the upper resia valley is located in the south-easternmost part of the valley, actually representing the only one with a series of well-preserved terminal moraine ridges. this cirque is longitudinally divided by the bila creek, and around the malga coot (fig. 5a), in the virtually southern portion, well-preserved glacial deposits are present. the three most evident ridges develop between 1270 and 1485 m a.s.l. (fig. 4). two more ridges at 1170 and 1205 m a.s.l. are preserved down valley, also interpreted as belonging to the malga coot glacier, since all the ridges are present on the orographic left of the bila creek. the entire north-facing slopes, between the creek flowing from the passo pradolina saddle (1351 m a.s.l.) towards north and the malga coot cirque, are covered by glacial deposits, mainly reworked by avalanche activity. the majority of the ridges in this sector are the result of avalanche paths, with ridges in between. only few of them are of glacial origin. the water divide between the resia and fella valleys has a ese-wnw trend from the mt. canin. at pusti gost (fig. 2) a wide plateau is present. it is covered by erratic boulders of dachstein limestone, while the moraines show a weathered top with reddish, partially colluviated soil (7.5yr munsell). no exotic boulders from the fella catchment are present. the middle-lower part of the resia valley is mainly characterised by the sequence of terraces (fig. 6). they extend between the settlements of stolvizza and san giorgio. the stolvizza alluvial terrace is positioned between the resia river to the south and the potoch creek to the north. it is the highest among the series of terraces with the top between 540 and 570 m a.s.l. it is rising approximately 100 m above the present resia riverbed, while only 50 m above the potoch creek. downstream, on the left bank of the resia river at the oseacco settlement, a staircase of terraces is present. two evident terraces can be recognized: the upper one with the top at 500 m a.s.l. and the other one 60 m below. their tops are completely made up of alluvial deposits. other smaller terraces are located next to the river bed between 415 and 420 m a.s.l. further downstream, another terrace at 465 m a.s.l. with the gniva settlement on the top (fig. 6) is positioned on the left bank of the resia river. about 50 m of incision formed by the stream flowing from the valley to the south, separates the gniva terrace from the oseacco terrace. the top of the eastern part of the gniva terrace is covered by alluvial deposits, meanwhile the western one is characterized by glacial deposits containing large boulders. moreover, two small ridges up to 15 m high and 200 m long, extending in the n-s direction, can be recognized on the top of the terrace. another flat surface to the west, separated from the fig. 6 geomorphological map and 3d lidar image of the middle resia valley at the junction with the barman valley. the yellow dashed line is the trace of the longitudinal profile of figure 8. purple dashed line indicates the rim of the barman moraine; the yellow arrow indicates the right wing of the nero fan. os: oseacco; pr: prato resia. glacial and proglacial deposits of the resia valley (ne italy): new insights of the alpine lgm gniva terrace by the 70 m incised barman river, extends between 475 and 530 m a.s.l. also this terrace has large boulders scattered on the surface and one ridge with the n-s orientation. going from the terrace upstream to the barman valley, glacial deposits are covered by deposits made up of boulders, as visible also from the undulate morphology they form (fig. 6). these deposits cover the area of 0,19 km2 and can be ascribed either to a landslide fallen on the barman glacier or to a postglacial landslide coming from the slopes of the monte colc (759 m a.s.l.) at the orographic left of the barman valley. north of the confluence between the resia and barman rivers a large terrace at 450 m a.s.l. is present at the right side of the valley. it extends between the san giorgio and prato di resia settlements. up to 10 m large boulders are scattered only along the edge of the terrace, while the other, northern part of the terrace surface is flat. the boulders are present also in the resia river bed below the terrace. these large boulders can be traced upwards to the terraces at the outlet of the barman river and, together with the ridges there situated, have been interpreted as belonging to a frontal moraine system from the barman valley. in the latter, some inner moraines are preserved in the wide flat area at the foot of the mt. musi northern slope. the last evident terrace is present west of the san giorgio settlement. the top of the terrace is between 410 and 420 m a.s.l. its surface is made up of coarse alluvial deposits (fig. 6). down valley, at the confluence between the resia river and nero creek, a large outwash fan was formed by the latter. its remnants can be recognized in the orographic right of the nero valley outlet, between 400 and 500 m a.s.l., where they cover glacial deposits. the last among the southern tributaries of the resia river is the resartico creek (fig. 7). at the orographic right of the resartico outlet the ridge between 380 and 435 m a.s.l. is a lateral moraine, extending up to 30 m above the present valley floor, ascribed to the resartico glacier. along the left slopes of the resia valley between the resartico and nero creeks, large debris-flow fans were formed (figs. 2 and 7) due to steep slopes and thick cataclastic deposits along the resiutta fault (fig. 2). some other glacigenic deposits scattered along the resia valley do not form clear geomorphological features and are therefore described only from a sedimentological and stratigraphic point of view in the following chapter. 6. sedimentology and stratigraphy the glacigenic deposits are distributed along both sides of the resia valley and have a discontinuous thickness depending on bedrock shape and presence of junction with tributaries (fig. 2). the morainic ridges recognized in lidar images were checked on the field and the description of the deposits is generally reported. the main sections are described in detail, namely going downstream: coritis, stolvizza, oseacco-zamlin, san giorgio-gniva and resiutta; here the superposition of different units provided the key relationships for unravel 92 fig. 7 geomorphological map and 3d lidar image of the outlet of the valley at resiutta. the yellow dashed line is the trace of the cross section of figure 13, the two palaeo-outlet are highlighted (yellow arrows). rs: resiutta colucci r. r. et al. 93 ling the evolutionary steps. these sections are correlated with the other scattered outcrops along a longitudinal profile (fig. 8) that better shows their distribution. 6.1. coritis the coritis section crops out in the upper resia valley (fig. 4), about 0.5 km northwest from the coritis settlement. it is located on the right side of the secco creek, near the confluence with the resia river. the outcrop is about 60 m wide and around 45 m high. the section consists of six main stratigraphic units. they are described from the bottom to the top as follows (fig. 9). crt-a: this unit is ~20 m thick and is composed of horizontally bedded deposits. the lower boundary is not visible since it is covered by talus debris. this unit consists of horizontally-bedded gravels (gh) clastsupported and heavily consolidated. clasts are subangular to sub-rounded, with average size from 1 to 2 cm, but the largest clasts range from 20 to 50 cm. the majority of the clasts are of local origin, although many exotic clasts can be found within the unit; these are sub-rounded and show oxidation cortex. also some fine-grained lenses of laminated to massive silty sand (sm-sl) are scattered within the gravels. the facies association can be interpreted as a proximal fluvial deposit. the lower boundary, defined also by the lateral outcropping bedrock, suggest the presence of a fluvial incision at least 300 m wide, substantially wider than the present 30 m of the modern incision. crt-b: this unit consists of laminated silt (fl) of hazel colour (2.5y munsell colour), in which many subangular to sub-rounded dropstones (grain to boulder size) are present. the deposit is characterized by folding and is heavily consolidated. the lower boundary is undulated. the thickness varies from 1 to 2.5 m, reaching ~5 m in the north-eastwards sector of the section. the unit can be related to glaciolacustrine environment, filling an undulate topography (fig. 10a). crt-c: this unit is about 8 m thick. it is characterized by matrix-supported massive diamicton (dmm) with grey silty matrix (5/10y munsell colour). clasts are predominantly sub-rounded to sub-angular, containing boulders up to 100 cm in size (fig. 10a). many clasts are polished, striated and faceted. the deposit is heavily consolidated and shows some irregular horizontal planes likely related to shear stress. it is ascribable to a lodgement till in subglacial environment. crt-d: the unit is ~3 m thick and is made up of matrixsupported, bedded coarse diamicton with sandy matrix (dms), boulders are concentrated in the lower part. fig. 8 longitudinal profile of the resia valley in which the sedimentary bodies and the moraines are plotted. detail on the reach from zamlin to the junction with the nero creek where the green dashed line represents the top of the late glacial aggradation driven by the damming of the barman glacier and the development of the nero creek fan. glacial and proglacial deposits of the resia valley (ne italy): new insights of the alpine lgm clasts are angular to sub-angular (fig. 10b). the deposit is consolidated and can be related to a supraglacial till with evidence of subsequent reworking. crt-e: the thickness of the unit is ~4 m. deposits are laminated silts and sands (fl-sh) of hazel colour (2.5y munsell colour). deposits are not folded and only few dropstones are present within the layer. this body can be ascribed to lacustrine bottomset and the presence of dropstones suggests a proglacial environment. crt-f: the upper-most unit is made of 6 m thick, clinostratified graded gravels, in which the dip angle descreases toward the top (fig. 10b). this unit consists of clast-supported coarse gravels. clasts are predominantly sub-rounded and of local origin. matrix is coarse sand. the deposit is unconsolidated and reaches up to the top of the slope. the deposit can be ascribed to the foreset beds passing to the topset of a 94 fig. 9 panoramic view and line-draw of the southern slope of the hudaraven terrace cut by secco creek (see fig. 4 for location). colucci r. r. et al. 95 delta fed by a nearby outwash stream. on the hudaraven terrace a moraine is present close to the terrace. the related diamicton is rich in carbonate boulders. this moraine was likely deposited by a glacier tongue coming from the ronc cirque (fig. 4), damming the resia valley and forming a lake whose deposits are represented by units crt-e and f. 6.2. stolvizza the section crops out along the potoch creek 300 m upstream of the village in correspondence to a waterfall, where the outcrop is 15 m high. a small earth pyramid is preserved downstream the waterfall. the section consists of four different units, whose description follows the line-draw of figure 11. fig. 10 a) transition between over-consolidated glacio-lacustrine deposits (crt-b) and the massive lodgement till (crt-c) in the coritis section. b) close-up to the diamicton with angular pebbles (crt-d) and the overlain glaciolacustrine (crt-e) and deltaic (crt-f) units under the hudaraven terrace surface. c) over-consolidated laminated fines with dropstones interbedded to massive diamicton (sto-b) in the stolvizza section. d) over-consolidated laminated lacustrine deposits with dropstones showing glaciotectonic deformations (resia riverbed close to oseacco). e) boulders along the resia river close to the junction with the barman. f) lateral moraine close to oseacco in which the till shows a rough inclined bedding. glacial and proglacial deposits of the resia valley (ne italy): new insights of the alpine lgm sto-a: this unit crops out in the lowermost part close to the bedrock, it is made of matrixto clast-supported massive diamicton (dmm-dcm), which includes small boulders (fig. 11a) of limestone and dolostone, while exotic pebbles are scattered. clasts are sub-angular to sub-rounded and many of them are polished and striated; matrix is silty sand. the deposit is heavily consolidated and the visible thickness is of about 1.5 m. the deposit can be generally interpreted as a subglacial till. sto-b: the boundary with the previous unit is irregular, this deposit is heterogeneous and consists of matrix to clast-supported diamicton, crudely clinostratified (dms-dcs) in metric beds, containing sub-angular to sub-rounded limestone and dolostone boulders 1 to 2 m large (fig. 11b). sub-rounded clasts of exotic lithologies are scattered. these look slightly weathered. the deposit is heavily consolidated. three distinct layers of laminated silt (fl), from 10 to 50 cm thick, are interbedded (fig. 10c). the presence of subrounded to sub-angular clasts, striated and polished, deeply disturb the planar lamination and they are interpreted as dropstones. these layers are heavily deformed in folds and are also heavily consolidated. on 96 fig. 11 panoramic view of the section along the potoch creek close to stolvizza, the glaciolacustrine layers are marked in red contours. a) e-w side and lateral boundary with the bedrock (hammer scale in yellow circle 40 cm long); b) n-s side to the left of the previous picture colucci r. r. et al. 97 the whole, the thickness is about 12 m. the presence of lacustrine lenses with many dropstones within the diamicton complex can be related to the presence of small ponds in subglacial marginal environment.the clinoforms in the dcs facies suggest the flowing of debris from the side of the glacier, while the deformation and the over-consolidation are related to the subsequent load of the glacier. sto-c: this unit is confined between the previous one and the bedrock cliff close to the waterfall (fig. 11a). the lateral relationship is hidden by talus deposits. the deposit is made up of clast supported gravel and sand (gcs-sl) showing a clinoforms (35°) towards the west, beds are normally graded and the clasts are sub-rounded to sub-angular, reaching the maximum size around 25 cm. the deposit is heavily consolidated. close to the bedrock the dip increases to 60°. the thickness reaches 10 m close to the cliff. considering the possible relationships with the other units, this deposit can be related to a small fan-delta confined between the bedrock and the ice in marginal or sub-glacial position. the increase of the dip angle close to the bedrock could be ascribed to the load of ice and sediments of unit sto-c on these deposits. 6.3. zamlin and oseacco the zamlin section (fig. 12) is located along the resia river upstream to the junction with the potoch fig. 12 panoramic view of the zamlin terrace from the resia riverbed, where the carnian bedrock crops out, and zoom on the main es glacial and proglacial deposits of the resia valley (ne italy): new insights of the alpine lgm creek. the basal boundary of the quaternary succession on the carnian bedrock (dolostone, gypsum and red clays of the travenanzes fm.; zanferrari et al., 2013) is irregular, as visible in the cross section of figure 8. the basal unit (zai-a) is made up of well bedded gravel, clast-supported and normally graded (gl). the bedding shows a gentle dip towards the w. the clasts are sub-rounded, mostly made up of carbonate fragments, exotic clasts are scarce. clast-size reaches 25 cm. the deposit is heavily consolidated and has a preserved thickness of 15 m. a 40 cm thick sandy layer slit the unit in two separate bodies showing the same sedimentological characteristics except for the progradation of the bedding, whose dip changes from w to wnw. it can be related to a progradation of a fan delta subsequently loaded by the advancing glacier. the upper surface is sharp and erosive. the unit at the top (zai-b) is made up of a gravelly diamicton, clast-supported and crudely bedded with many boulders (dcs). the visible thickness is about 7 m. the deposit can be ascribed to high energy regime in fluvioglacial environment. because of the absence of outcrops in the upper portion of the terrace, from 490 to 537 m, it is not possible to determinate the effectiveness of the presence of a lodgement till related to the resia glacier, as the overconsolidation of the basal unit seems to suggest. the topmost flat surface, is characterised by loose coarse gravels, clast-supported and crudely bedded, with sandy matrix. downstream of zamlin, on the left bank of the resia, a fine grained laminated silt (fl), containing many sub-rounded to sub-angular clasts, some of them striated, lays on the carnian bedrock. the visible thickness is about 4 m. the deposit is heavily consolidated and very deformed by folds and faults (fig. 10d). matrix -supported massive diamicton (dmm), showing shear planes and containing many striated pebbles, is associated. for the whole stack a subglacial deposition of till and glaciolacustrine fines can be raised. the left slope of the valley is characterised by matrix-supported massive to roughly bedded diamicton (dmm-dms) with boulders, from the bottom till about 670 m a.s.l. the top of the terrace from stolvizza to zamlin can be continuously traced along the oseacco terrace (figs. 6 and 8). along the cut of the creek close to oseacco, a section provides the architecture of the latter. at the bottom of the slope a fine grained laminated silt and sand deposit crops out (fl), containing many sub-rounded to sub-angular clasts, some of them striated, interpreted as dropstones. the deposit is heavily consolidated and deformed by folds and small faults; the visible thickness is about 6 m. it intertongues with graded gravels, clats-supported and heavily consolidated (gl-gh). clasts are sub-rounded and mostly made of carbonates, exotic clasts are lacking. the thickness is about 8 m. a sharp surface on the top cut this body and above a massive diamicton, matrix supported (dmm) crops out. it is made of big boulders of carbonates in a sandy-silty matrix (2.5y munsell colour). the deposits is consolidated and has a visible thickness of about 15 m, it is interpreted as a subglacial till. 6.4. san giorgio and gniva at gniva, on the left bank of the resia valley, a long section crops out at the junction between the resia and the barman. along the road fine grained laminated silt and sands crop out (fl), containing many subrounded to sub-angular clasts, some of them striated, lay on the carnian bedrock. the visible thickness is about 2 m. the deposit is heavily consolidated and very deformed, with folds and faults. they gradually pass to clinostratified graded gravels, clats-supported, locally cemented and heavily consolidated (gl-gh). clasts are sub-rounded and mostly made of carbonates pointing to the barman catchment while exotic clasts are lacking. the thickness is about 15 m. also here a sharp surface on the top cut the gravel body; above a massive diamicton, matrix-supported (dmm) crops out, made of subangular to sub-rounded boulders of carbonates in a sandy-silty matrix (2.5y munsell colour). the deposit is consolidated and has a visible thickness of about 15 m, and is interpreted as a subglacial till. the clinostratified unit has been interpreted as a pre-würmian deltaic deposit (desio, 1926) buried by würmian glacial units. considering the overconsolidation and the cementation of the lowermost deposits, their relationship with the glaciolacustrine fines, they are interpreted as the infill of the valley during the widespread of the glacier at the onset of the lgm, whose sedimentary evidence is the upper diamicton. the morainic ridges at the outlet of the barman valley cover the succession. these are made of matrixsupported massive diamicton (dmm), with big boulders of carbonates; the silty-sandy matrix shows a pale yellow colour (2.5y munsell). the right bank of the resia river at san giorgio is characterised by a basal fine grained laminated silt and sands (fl), containing many sub-rounded to sub-angular clasts, visible for 2 m. it is overlain by graded gravels, clast-supported, locally cemented and heavily consolidated (gl-gh); the thickness is undetermined for the presence of cover debris. at the top of the terrace big boulders (up to 10 m large) are scattered on the surface close to the rim, while to the north the terrace surface is flat. the boulders show a petrographic signature from the barman catchment and can be considered as erratics. the same boulders fill the resia reach 700 m long (fig. 10e). 6.5. resiutta at the outlet of the resia valley, near resiutta, there are two successions filling concave base morphologies in the dolostone bedrock (fig. 13). the first is about 100 m large, with the base at 470 m a.s.l. and filled by 40-m thick succession, starting with laminated sand and silt (sl-fl), unweathered (2.5y munsell colour), passing to a weakly cemented gravel, clast-supported and crudely bedded (gh), clasts are sub-rounded and of carbonate petrography. towards the top the bedding is better organized (gp). the total thickness of this unit (res-a) is about 30 m. the deposit is covered by 10 m thick unit (res-b) made up of matrix-supported massive diamicton (dmm); matrix is silty (10yr munsell colour), clasts are sub-angular to sub-rounded, striated and polished; the petrography points to the fella basin for the 98 colucci r. r. et al. 99 presence of many lithologies from the paleocarnic chain. the unit res-a can be ascribed to a filling from the resia valley caused by downstream damming by the fella glacier, which subsequently deposited the subglacial till (res-b) above. the second succession crops out 500 m westwards. it is a 300 m large and characterised by two sedimentary units. unit res-c is made up of matrixsupported massive diamicton (dmm) with many boulders and striated sub-angular to sub-rounded clasts,. the polygenic petrography indicates the provenance from the fella catchment. the visible thickness reaches 90 m. the unit laterally lays on the bedrock in the eastern part of the section. a second unit (res-d) has a lateral boundary with the previous; it is made of horizontally to planar cross-bedded gravels (gh-gp), weakly cemented; clasts are sub-rounded to rounded and made of carbonate lithologies belonging to the resia valley. the basal boundary on the dolostone bedrock is at 330 m a.s.l. for a preserved thickness of about 60 m. also these two units represent a damming phase of the resia valley from the fella glacier, whose the elevation is about 150 m lower than the previous. 6.6. other alluvial deposits these deposits are scattered along the valley, from the outlet at resiutta to stolvizza (figs. 2 and 8). they are made up of sandy gravels, horizontally crudely bedded (gh), clast-supported; lenses of massive to trough cross-bedded sand (sm-st) or silty sand are scattered. clasts are sub-rounded. the deposits are in general normally consolidated. they are interpreted as the result of outwash streams during the withdrawal of the glaciers in the late glacial and the deposition of tributary creeks as the barman and nero. 6.7. other glacial deposits along the valley many patches of chaotic diamicton, matrix-supported (dmm) and normallyto overconsolidated are scattered. rough inclined bedding can be present. these deposits are characterised by angular to sub-rounded clasts, faceted, polished and striated. meter-size boulders are common. matrix is a sandy silt (5/10y to 10yr munsell color). in the over-consolidated diamicton the silty matrix is very abundant, while the normally-consolidated is richer in sand. the first can be assumed as lodgement till, and its position is always close to the bottom of the succession. the second is widespread on the valley slopes, from the bottom to the highest elevation of these remnants, and can be related to supraglacial till related to lateral moraines (fig. 10f). as shown by the longitudinal profile, the glacial deposits cover a belt from 350 to 800 m a.s.l. along the valley, while in the uppermost portion (the former accumulation area) they are present at higher altitude. the petrographic composition reflects the bedrock outcropping along the valley, and those related to the barman tributary glacier are very rich in jurassic-cretaceous limestones. however, several sub-rounded pebbles and boulders of volcanites, quartz-conglomerates and green to red sandstones coming from the palaeocarnic chain (venturini et al., 2002) can be recognised in the upper resia valley. it is remarkable that most of them show slight weathering or oxidation on the surface. 7. the evolution of the resia valley since the onset of the lgm the abundance of glacigenic deposits in the resia valley is peculiar in the tagliamento catchment, where the trunk valleys are filled with late glacial to holocene fluvial and lacustrine successions (venturini, 2003; venfig. 13 cross section of the outlet of the valley at resiutta (see fig. 7 for location). glacial and proglacial deposits of the resia valley (ne italy): new insights of the alpine lgm turini et al., 2004; monegato & stefani, 2011). the presence of wide outcrops with overlapping sedimentary units provided new insights on the evolution of the valley at the onset of a glaciation and in the decay as well, as shown in the present study through geomorphological and sedimentological analyses, despite the lack of new datings. the stratigraphic reconstruction along the tagliamento valley (zanferrari et al., 2013) provided good correlations with the lgm units of the tagliamento end moraine system (monegato et al., 2007). 7.1. pre-lgm topography the topography of the valley at the onset of the last glaciation can be inferred (fig. 14a) from the short reaches filled by deposits that crop out at coritis, along the stolvizza-zamlin area and at the outlet near resiutta. the valley section at coritis is presently about 40 m large, flowing in a 5-m narrow gorge just downstream of the resia river ronch creek junction (fig. 4). the difference is related to the change in bedrock unit, from red clay and gypsum formation to dolostones. the former reach was about 200 m large, as evidenced by the alluvial filling of unit crt-a. it is remarkable that the basal surface of this paleotopography, at 575 m a.s.l., is lower than the flat top of the bedrock ridge at the gorge, located ~300 m downstream. hence, a wide reach was present in the “soft” rocks sector also in the pre-lgm time, but it has to be assumed that the modern narrow gorge was already there at that time and survived to glacial quarrying and subglacial erosion. further investigations are necessary for establishing possible neotectonics reasons. downstream, from stolvizza to zamlin, the modern resia riverbed shifts westwards and cuts the bedrock in several right-angle reaches some hundreds of meters long (fig. 4). at zamlin, the filling succession clearly deepens towards the north, suggesting that the path of the river was located some hundreds of meters northwards (fig. 14a). the basal surface at stolvizza of the unit sto-a could represent a small remnant of the pre-lgm topography. at gniva the fan delta deposits have basal surface at 380 m a.s.l. these have been considered prewürmian “interglacial” in age (desio, 1926; cucchi & finocchiaro, 2009), because of the cementation and deformation. however, their relationship with glaciolacustrine sediments at the resia/barman junction suggests a deposition during the onset of the last glaciations and implies a damming downstream. at resiutta (fig. 13), two section at different elevation show a similar setting of fluvial deposits (res-a and res-d) belonging to the resia valley, whose aggradation was triggered by damming from the fella glacier, as testified by the glacial units (res-b and res-c) with basal surfaces at 470 and 330 m a.s.l. the modern resia outlet is located 300 m westwards and has an elevation of 317 m a.s.l. the higher alluvial deposit can be related to a spillway during the lgm, then covered by the ice stream. however, it cannot be excluded that this path acted as valley outlet during the middle pleistocene. the second section is wider and filled by glacial deposits that made low elevated moraines at resiutta (battello & vaia, 1999). these can be ascribed to a recessional stage of the fella trunk glacier damming the valley. the basal surface at 330 m a.s.l. was likely the outlet before the lgm, with an elevation of about 10 m above the modern outlet of the river 7.2. lgm the extent of the maximum development of the glaciers in the tagliamento catchment and in its tributary from resia valley has been debated since taramelli’s (1875) pioneering work,. the thickness of the tagliamento glacier at the fella/tagliamento junction has been interpreted to be up to 1000 m (penck & brückner, 1909; castiglioni, 1940; gortani, 1959; van husen, 1987; venturini, 2003), while interpretation of thinner ice streams was lately speculated (vai & cantelli, 2004) and recently a ~650 m thick glacier was inferred (zanferrari et al., 2013). the reconstruction of the resia glacier provided by the distribution of glacial deposits yield a ~550 m thick ice stream (figs. 8 and 14b), which covered most of the catchment and joined the fella glacier in the lower valley. however, it did not reach the pusti gost plateau at 1200 m a.s.l. the abundance of heavily consolidated glacial but also glaciolacustrine and fluvioglacial deposits along the valley, from coritis to resiutta, yield information on the onset of the glaciation. the development of ice streams took place in an articulated longitudinal valley, with narrow reaches spaced by larger segment and with transverse junctions with northexposed tributaries enhancing the development of many lakes created by glacier damming. their preservation in some reaches of the valley is similar to the configuration of the onset of the last glaciation that was recently evidenced in the austrian alps in tributary catchments of the inn valley (reitner, 2005; reitner et al., 2010); here the development of glaciolacustrine and deltaic environments was related to the advance of the glaciers. along the inn valley, despite the subsequent flow of the inn glacier, one of the largest of the alps, succession related and dated to the late mis3 are preserved (starnberger et al., 2013a,b; spötl et al., 2013). the climax of the glaciation in the southeastern alpine range lasted from ~26 to 19 ka bp as constrained by the oscillation of the piedmont lobe of the tagliamento glacier (fontana et al., 2014). during this time span the resia valley was covered by flowing ice streams (fig. 14b). the interaction of the base of the glacier with the sharp pre-glacial topography caused the presence of sub-glacial till containing big sub-angular boulders, as in the stolvizza succession (fig. 11). the connection with the fella glacier took place in the resiutta area. the major glaciers were the barman and the ronch, whose accumulation areas are below the western wall of the mt. canin. the ela for the julian prealps (mt. chiampon area, fig. 1) during the lgm was estimated at about 1150 m (monegato, 2012). the calculation for the resia glacier is unreliable. however, the ela for the barman glacier during the late glacial (see chapter 7.3) indicates a considerably lower elevation. the reconstructed configuration of the glaciers during the lgm makes the presence of exotic clasts in the upper valley through transfluences of the fella glacier unconvincing, as already pointed by desio (1926), who had to force an oversized fella glacier into the resia 100 colucci r. r. et al. 101 valley during the “würmian glaciation”. most of the exotic clasts show oxidation or weathering and their presence in the deposits (crt-a and sto-b), related to the onset of the glaciation, make probable their primary deposition before the lgm during a middle pleistocene glacial expansion, and their reworking during the lgm. the absence of exotic boulders in the pusti gost plateau is consistent with a lack of transfluence to the upper resia valley. in fact, the plateau remained outside the lgm deposition, as inferred by the weathering of the deposits of the pusti gost. 7.3. late glacial the successions of the resia valley have been mostly considered as related to the late glacial since desio (1926). for this reason a correlation with the classic alpine stadials (e.g., penck & brückner, 1909; ivyochs et al., 2008) has been attempted so far (desio, 1926; venturini, 2003; tintor & andri�, 2014). several advance pulses were recognised also in other sectors of the tagliamento catchment and related to five definite stadial phases (from bühl to egesen) stratigraphically grouped in the “alte valli subsynthem” (venturini et al., 2009). however, a clear attribution to the alpine stadials becomes speculative without chronological constrains. in the resia valley at least two clearly distinct stadial advances were recognised (fig. 14c and 14d), but a specific attribution to the alpine stadials is unreliable. the first stadial unit (fig. 14c) was characterised by the spread of the southern tributaries that dammed the valley with the glacier (barman and resartico) or with the spread of outwash fan (rio nero). the barman is the largest system and its advance formed a small frontal system at san giorgio/gniva sector. according to desio this damming created a lake, whose lacustrine fines were recognized at prato resia (figure 24 in desio, 1926), while the valley upstream was filled by the outwash deposits of different ice streams flowing from the mt. canin and the wide accumulation area around malga coot. the presence of terraces downstream of the barman moraines, as evidenced by the correlation of the tread of the terraces (fig. 8), points to a damming by the outwash fan of the nero creek, whose east wing has a similar elevation. finally, the elevation of the resartico moraine in correspondence to the present resia valley floor suggests that also the resartico glacier dammed the lower reach of the valley. in the second stadial phase (fig. 14d) the glaciers were in general confined to the head of the valleys. however, in the upper resia six single glaciers flowed till ~750 m a.s.l., while in the barman valley the glaciers probably even merged. at this time the terraces from coritis to san giorgio were already shaped by the incision of the drainage network. the ela of the barman glacier in the first stadial phase would be as low as 834 m a.s.l., considering the fig. 14 reconstruction of the glaciers in the resia valley from the onset of the lgm to the late glacial. the blue line in the pre-lgm indicates the possible path of resia river, the blue arrows show the glacier initiation areas. the elas of the barman glacier in the late glacial 1 are marked with red lines. glacial and proglacial deposits of the resia valley (ne italy): new insights of the alpine lgm typical aar (0.67) for the glaciers in the european alps (gross et al., 1976). assuming a great amount of snow accumulation from avalanches, which is supported by the avalanche path distribution map, the aars in the barman valley were likely lower. we should also consider the influence of debris covering on the increment of the size of the ablation area, related to landslide activity in the terminal part of the valley and a general topographic setting with prevailing steep slopes. using the aar 0.3, the ela would be at 1345 m a.s.l. this value is comparable to that calculated in the nearby mt. chiampon range in the julian prealps (~1370-1450 m) (monegato, 2012). even 1188 m a.s.l. (aar 0.4) would be a reasonable value for the ela of the barman glacier since in high mountain areas, the aars could highly vary between glaciers even within small regions (benn & lehmkuhl, 2000). moreover, the ela of the barman glacier was probably the lowest one among the glaciers in the resia valley owing to a great topographic effect. due to a lack of geomorphological evidence for calculating the ela for the second stadial phase, we can only assume that the ela was up to 100 m higher in comparison with the first stadial, as was found for the mt. chiampon range (monegato, 2012). 8. climatological considerations on the onset of the glaciers in the resia valley observations of the present evolution of some semi-permanent snow/firn patches, mainly formed by avalanches activity, allow to make some assumptions on the past (and future) onset of the glaciation of the resia valley. the glaciers probably start to form at the toudule cirque, probably able to give birth to a fast growing tongue, and from the north facing slopes of mount musi and plauris. shaded aspect, high precipitation and avalanche activity are thus capable in supporting the growing of the glaciers in the higher and northerly aspects of the resia valley and in the malga coot cirque. meanwhile the subsequent lowering of temperature conditions is able to cause a gradual increase of snow cover, especially in the orographic left, leading to a thickening and widening of the existing glaciers, therefore accelerating the flow and lowering the glacier tongues. once all the smaller ice bodies tend to converge and form the main resia glacier, the system can be considered virtually completed with all the smaller fed glacial bodies acting as a unique system, flowing from east to west. at this stage the persistence of this glacial system lives a delicate equilibrium where small changes in maat or map can lead to large variations in massbalance, particularly evident in area with high precipitation. also during present time, even if globally glacier mass balance has been shown to be closely related to summer temperatures (ohmura et al., 1992, hughes & braithwaite, 2008), it was observed that the accumulation-type glaciers are mainly controlled by the winter balance (nesje et al., 1995; 2000). more recently colucci & guglielmin (2014) found that the present small glaciers of the julian alps are mainly influenced by winter precipitation, instead of mean summer temperatures, owing to the peculiar climatological characteristics of the area. 9. conclusions the resia valley represents a key area for depicting the sedimentary evolution during the last glaciation in the eastern southern alps. the thick glacigenic successions allowed the reconstruction of the dynamics of the onset of the glaciation, which was characterised by the initial spread of the glaciers of the canin-toudule and the barman with the infilling of the former valley with fluvioglacial deposits (i.e., crt-a), and glaciolacustrine successions (i.e., zai-a and the downstream laminated lacustrine fines). the spread of the resia glacier covered these units, causing their over-consolidation. laterally, the interaction of the base of the glacier with the sharp pre-glacial topography caused the formation of peculiar subglacial deposits, with big sub-angular boulders and glaciolacustrine fines (stolvizza section). the resia glacier during the lgm reached the maximum thickness of ca. 550 m, joining the fella glacier at resiutta. during the late glacial, at least two main stadials were recognised through the presence of frontal moraines and ice-dammed deposits. in the first, glacier streams flowed down the resartico and barman valleys, damming the trunk valley and causing the formation of lakes and the aggradation of the fluvioglacial deposits fed by the outwash streams from the glaciers of the upper valley. in the second stadial phase glaciers were confined in the upper accumulation areas, and only the barman and canin-toudule ice streams reached the base of the slope, thanks to the climatological setting. the ela calculation at 1188 m a.s.l. (aar 0.4) for the barman glacier during the first late glacial phase is similar to the lgm ela for the julian prealps. this low elevation points to the effect of debris cover and avalanching in decreasing the size of the accumulation area. in fact, the accumulation areas of the resia catchment are located in one of the highest precipitation rate sector of the alps (present map > 3000 mm). these climatological characteristics still allow the preservation of very small glaciers, glacierets and firn-patches even under the present, warmer climate, suggesting the locations and conditions that may have triggered (and will trigger) the onset and growing of new glacial areas. acknowledgments this work is part of a co-operation agreement between the university of ljubljana, faculty of arts, department of geography, and the national research council (cnr), institute of geosciences and earth resources torino (igg) and institute of marine sciences trieste (ismar). the surveys and data analyses have been carried out thanks to a phd fellowship of the slovene human resources development and scholarship fund, within the co-operation agreements 0000325 13/01/2014 between igg and ismar. we thank the civil defense of friuli venezia giulia for the lidar images of resia valley area. we thank the direzione centrale risorse agricole naturali e forestali for providing us with the map of avalanche tracks. we also deeply thank the parco naturale regionale delle prealpi giulie for the great logistic support during the fieldworks and 102 colucci r. r. et al. 103 marco di leonardo for the picture of the boulders in the resia river. the reviews provided by f. gianotti and j. reitner greatly improved the work. references battello e., vaia f. (1999) un paleoalveo in val resia. gortania atti museo friulano storia naturale, 21, 33-38. bavec m., tulaczyk s.m., mahan s.a., stock g.m. (2004) late quaternary glaciation of the upper so�a river region (southern julian alps, nw slovenia). sedimentary geology, 165, 165-183. bavec m., verbi� t. (2011) glacial history of slovenia. development in quaternary science, 15, 385-392. benn d.i., lehmkuhl f. (2000) mass balance and equilibrium-line altitudes of glaciers in high-mountain environments. quaternary international, 65-66, 15 -29. brückner e. (1891) eizeit-studien in den südöstlichen alpen. 1. die postglacialen gletscher der julischen alpen. x. jahresbericht der geogr. ges. bern. 1891, 157-162. carton a., bondesan a., fontana a., meneghel m., miola a., mozzi p., primon s., surian n. (2009) geomorphological evolution and sediment transfer in the piave river watershed (north-eastern italy) since the lgm. géomorphologie: relief, processus, environment, 3, 37-58. carturan l., baldassi g.a., bondesan a., calligaro s., carton a., cazorzi f., dalla fontana g., francese r., guarnieri a., milan n., moro d., tarolli p. (2013) current behaviour and dynamics of the lowermost italian glacier (montasio occidentale, julian alps). geografiska annaler, a 95, 79-96. carulli g.b. (2006) carta geologica del friuli venezia giulia (scala 1:150.000, con note ill.). regione a. friuli venezia giulia, direz. ambiente ll.pp., se.l.ca, firenze. castiglioni b. (1940) l’italia nell’età quaternaria. carta alla scala 1:200000. atlante fisico-economico d’italia, tci, milano. cavallin a., martinis b. (1985) le sismiti nelle alpi friulane. in alto, 68, 104-113. colucci r.r., guglielmin m. (2014) precipitationtemperature changes and evolution of a small glacier in the southeastern european alps during the last 90 years. international journal of climatology. doi: 10.1002/joc.4172 cucchi f., finocchiaro f. (2009) conglomerati affioranti presso il ponte sul torrente resia. in: cucchi f., finocchiaro f., muscio g. (eds.): geositi del friuli venezia giulia. regione autonoma friuli venezia giulia. tipografia arti grafiche friulane / imoco spa, 148. desio a. (1926) l'evoluzione morfologica del bacino del fella. atti società italiana scienze naturali, 65, 205-461. ehlers j., gibbard p.l. (2004) quaternary glaciationsextent and chronology-part i: europe, elsevier, amsterdam, holland. eyles n., eyles c.h., miall a.d. (1983) lithofacies types and vertical pro�le models; an alternative approach to the description and environmental interpretation of glacial diamict and diamictite sequences. sedimentology, 30, 393-410. fontana a., monegato g., devoto s., zavagno e., burla i., cucchi f. (2014) evolution of an alpine fluvioglacial system at the lgm decay: the cormor megafan (ne italy). geomorphology, 204, 136153. gortani m. (1959) carta della glaciazione würmiana in friuli. rendiconti atti accademia scienze istituto di bologna, 6, 1-11. gortani m., desio a. (1925) carta geologica delle tre venezie. foglio 14-pontebba. uff. idrogr. r. magistrato acque venezia, 86 pp., padova. gregorcic g., kastelec d., rakovec j., vrhovec t. (2001) evaluation of surface precipitation radar data during some map iops in western slovenia, university of ljubljiana, slovenia. map newsletter no.15, june 2001. gross g., kerschner h., patzelt g. (1976) methodische untersuchungen über die schneegrenze in alpinen gletschergebieten. zeitschrift für gletscherkunde und glazialgeologie, 12, 223-251. hughes p.d., braithwaite r.j. (2008) application of a degree-day model to reconstruct pleistocene glacial climates. quaternary. research, 69(1), 110-116. kuhn m. (1995) the mass balance of very small glaciers. zeitschrift für gletscherkunde und glazialgeologie, 31(1-2), 171-179. isotta f.a., frei c., weilguni v., per�ec tadi� m., lassègues p., rudolf b., pavan v., cacciamani c., antolini g., ratto s.m., munari m., micheletti s., bonati s., lussana c., ronchi c., panettirei e., marigo g., verta�nik g. (2014) the climate of daily precipitation in the alps: development and analysis of a high-resolution grid dataset from panalpine rain-gauge data. international journal of climatology, 34(5), 1657-1675, doi: 10.1002/ joc.3794 ivy-ochs s., kerschner h., reuther a., preusser f., heine k., maisch m., kubik p.w. & schlüchter c. (2008) chronology of the last glacial cycle in the european alps. journal of quaternary science, 23, 559-573. miall a.d. (1996) the geology of �uvial deposits: sedimentary facies. basin analysis and petroleum geology. springer-verlag, berlin, 582 pp. monegato g. (2012) local glaciers in the julian prealps (ne italy) during the last glacial maximum. alpine and mediterranean quaternary, 25, 5 -14. monegato g., ravazzi c., donegana m., pini r., calderoni g., wick l. (2007) evidence of a two-fold glacial advance during the last glacial maximum in the tagliamento end moraine system (eastern alps). quaternary research, 68(2), 284-302. monegato g., stefani c. (2011) preservation of a longlived �uvial systemin a mountain chain: the tagliamento valley (southeastern italian alps). in: davidson s.k., leleu s., north c.p. (eds.): from glacial and proglacial deposits of the resia valley (ne italy): new insights of the alpine lgm river to rock record: the preservation of �uvial sediments and their subsequent interpretation: sepm spec. publ., 97, 359-374. nacsn north american commission on stratigraphic nomenclature (1983) north american stratigraphic code. bullettin american association petroleum geologists, 67, 841-875. nesje a., johannessen t., birks h.j.b. (1995) briksdalsbreen, western norway: climatic effects on the terminal response of a temperate glacier between 1901 and 1994. holocene, 5, 343-347. nesje a., lie ø., dahl s.o. (2000) is the north atlantic oscillation reflected in scandinavian glacier mass balance records? journal of quaternary science, 15, 587-601. norbiato d., borga m., sangati m., zanon f. (2007) regional frequency analysis of extreme precipitation in the eastern italian alps and the august 29, 2003 flash flood. journal of hydrology, 345, 149 166. ohmura a., kasser p., funk m. (1992) climate at the equilibrium line of glaciers. journal of glaciology, 38, 397-411. penck a., brückner e. (1909) die alpen im eiszeitalter. bd. i-iii. leipzig: tauchnitz. pini r., ravazzi c., reimer p.j. (2010) the vegetation and climate history of the last glacial cycle in a new pollen record from fimon lake (southern alpine foreland, n-italy). quaternary science reviews, 29, 3115-3137. porter s.c. (2001) snowline depression in the tropics during the last glaciation. quaternary science reviews, 20, 1067-1091. reitner j.m. (2005) quartärgeologie und landschaftsentwicklungim raum kitzbühel st. johann i.t. hopfgarten (nordtirol) vom riss bis in das würmspätglazial (mis 6-2). phd-thesis, 190 p., university of vienna. reitner j.m., gruber w., römer a., morawetz r. (2010) alpine overdeepenings and paleo-ice �ow changes: an integrated geophysicalsedimentological case study from tyrol (austria). swiss journal of geoscience, 103, 385-405. serandrei barbero r., rabagliati r., zecchetto s. (1989) analisi delle misure alle fronti dei ghiacciai delle alpi giulie e correlazioni con i dati climatici. geografia fisica e dinamica quaternaria, 12, 139-149. spötl c., starnberger r., reimer r.w. (2013) a new radiocarbon chronology of baumkirchen, stratotype for the onset of the upper würmian in the alps. journal of quaternary science, 28, 552-558. starnberger r., drescher-schneider r., reitner j.m., rodnight h., reimer p.j., spötl c. (2013a) late pleistocene climate change and landscape dynamics in the eastern alps: the inner-alpine unterangerberg record (austria). quaternary science reviews, 68, 17-42. starnberger r., rodnight h., spötl c. (2013b) luminescence dating of fine-grain lacustrine sediments from the late pleistocene unterangerberg site (tyrol, austria). austrian journal of earth sciences, 106/1, 4-15. taramelli t. (1875) dei terreni morenici e alluvionali del friuli. annali regio istituto tecnoco di udine, 8, 1-91. tellini a. (1981) da tercento a resia. note geologiche. in alto, 2, 6-13. tintor w., andri� m. (2014) lateglacial studies in the western valleys of the italian julian alps and in the koritnica valley. acta geographica slovenica, 54-1. doi: 103986/ags54101 vai g.b., cantelli l. (2004) litho-palaeoenvironmental maps of italy during the last two climatic extremes. l.a.c., firenze. vaia f., zorzin r. (1981) fenomeni di tettonica recente in val resia (prealpi giulie). gortania atti museo friulano storia naturale, 3, 5-20. van husen d. (1987) die ostalpen und ihr vorland in der letzten eiszeit (würm). geologische bundesanstalt, vienna. venturini c. (2003) il friuli nel quaternario: l’evoluzione del territorio. in: muscio g. (ed.), glacies. comune di udine museo friulano storia naturale, udine, 23-106. venturini c., pondrelli m., fontana c., delzotto s., discenza k. (2002) carta geologica delle alpi carniche geological map of the carnic alps, scala 1:25.000 (foglio orientale m. tersadia-ugovizza). s.el.ca, firenze. venturini c., discenza k., garuti d. (2004) the drafting project of a composite geosite: the sutrio palaeolake (carnic alps). in: pasquarè g., venturini c., groppelli g. (eds.): mapping geology in italy, mapping geology in italy, apat-servizio geologico d’italia, igc firenze 2004, 311-320, selca (firenze). venturini c., spalletta c., vai g.b., pondrelli m., fontana c., delzotto s., longo salvador g., carulli g.b. (2009) note illustrative al f°. 031 ampezzo (carta geologica d’italia alla scala 1:50.000). ispra dipartimento difesa dei suoli servizio geologico nazionale. zanferrari a., masetti d., monegato g., poli m.e. (2013) note illustrative della carta geologica d’italia alla scala 1:50.000; foglio 049 “gemona del friuli”. ispra-servizio geologico d’italia regione autonoma friuli-venezia giulia. žebre m., stepišnik u., kodelja b. (2014) traces of pleistocene glaciation on trnovski gozd. dela, 39, 157-170. 104 ms. received: september 25, 2014 final text received: december 10, 2014 colucci r. r. et al. base rock glacier relitti e antica distribuzione del permafrost nel gruppo adamello presanella (alpi centrali) roberto seppi1, alberto carton2 & carlo baroni3 1dipartimento di scienze della terra, università di pavia 2dipartimento di geografia “g. morandini”, università di padova. 3dipartimento di scienze della terra, università di pisa. corresponding author: r. seppi <roberto.seppi@unipv.it> riassunto: seppi r. et al., rock glacier relitti e antica distribuzione del permafrost nel gruppo adamello presanella (alpi centrali). (it issn 0394-3356, 2010). l’antica e l’attuale quota del limite inferiore del permafrost nel gruppo adamello presanella (alpi centrali) sono state definite utilizzando un catasto dei rock glacier. il catasto, basato sull’esame di fotografie aeree e su rilievi di terreno, documenta la presenza di un totale di 216 rock glacier, 128 dei quali sono stati classificati come relitti. le forme relitte hanno un corpo appiattito, una scarpata frontale poco ripida e sono caratterizzate dalla presenza di numerose cavità. nella maggior parte dei casi la superficie è coperta da una densa vegetazione e la loro fronte raggiunge l’attuale limite superiore degli alberi. la distribuzione delle forme attive/inattive consente di stimare un limite inferiore del permafrost attualmente collocato a circa 2500 m s.l.m., una quota 430 m più elevata di quella suggerita dalle forme relitte. nell’area studiata non esistono stime dell’età delle forme relitte basate su datazioni cronologiche, tuttavia è stato possibile confrontare la distribuzione dei rock glacier relitti con l’estensione dei ghiacciai durante il tardoglaciale, utilizzando una cartografia ottenuta dalla distribuzione delle morene. il confronto consente di stimare un’età posteriore allo stadio di gschnitz per la maggior parte dei rock glacier relitti (87 su 128). poiché, a scala regionale, il limite inferiore del permafrost discontinuo è collocato ad una quota che corrisponde con l’isotema media annua dell’aria di –1/–2°c, la differenza di temperatura media annua che corrisponde alla differenza di quota della fronte tra rock glacier attivi/inattivi e relitti può essere stimata utilizzando il gradiente medio di temperatura dell’aria calcolato per questo gruppo montuoso, pari a 0,59°c/100 m. la differenza di quota delle fronti dei rock glacier coincide con una differenza di temperatura media annua di circa 2,5°c e varia da circa 2,4°c sui versanti esposti a n a circa 2,7°c su quelli esposti a sud. questi dati forniscono una stima della differenza di temperatura media annua dell’aria intercorsa tra il tardoglaciale (quando i rock glacier attualmente relitti erano attivi) e il presente. abstract: seppi r. et al., relict rock glaciers and past permafrost distribution in the adamello presanella group (central alps). (it issn 0394-3356, 2010). the current and the past lower limit of permafrost has been estimated in the adamello presanella group (central alps, italy) using a rock glacier inventory. the inventory was based on aerial photographs analyses and field surveys. in the inventory, a total of 216 rock glaciers have been reported and described, and 128 of these are regarded as relict landforms. these rock glaciers have a flat morphology, a gently sloping frontal scarp and a surface characterized by several cavities. in most cases their surface is covered by dense vegetation, and often their front reach the present tree line. the distribution of active/inactive landforms allows to estimate a lower limit of discontinuous permafrost presently located at about 2500 m a.s.l., an altitude 430 m higher than that suggested by the relict landforms. no chronological data exist in this region about the age of the relict rock glaciers. nevertheless, a visual comparison with the late glacial extent of glaciers, as provided by a map obtained from the moraines geometry, allows to estimate an age no older than the late glacial gschnitz stage for the most of them (87 on 128). since the lower boundary of discontinuous permafrost is located at an altitude corresponding with the maat (mean annual air temperature) of -1/-2°c, the difference in maat that coincides with the difference in elevation between the fronts of active/inactive and relict rock glaciers can be estimated using the vertical temperature lapse rate calculated for this mountain group (0.59°c/100 m). the altitudinal difference between the fronts of active/inactive and relict rock glaciers coincides with a difference of about 2.5°c in the maat. this difference reduces to about 2.4°c on northern slopes and increases to about 2.7°c on southern slopes. this data gave us an estimate of the maat difference between the late glacial (when the presently relict rock glaciers were active) and the present day. parole chiave: permafrost, rock glacier relitti, tardoglaciale, alpi italiane. keywords: permafrost, relict rock glaciers, late glacial, italian alps. il quaternario italian journal of quaternary sciences 23(1), 2010 137-144 1. introduzione i rock glacier sono tra le più diffuse forme degli ambienti periglaciali alpini e rappresentano evidenti manifestazioni della presenza di permafrost discontinuo. si originano a seguito della lenta deformazione di materiale detritico perennemente congelato e sono caratterizzati da particolari strutture superficiali quali rughe, solchi, cavità e contropendenze. il dibattito scientifico sull’origine di queste forme è ancora attuale e le diverse interpretazioni nascono da una duplice spiegazione dell’origine del ghiaccio contenuto nei corpi detritici: se esso sia ghiaccio formatosi in situ per processi di aggradazione del permafrost o se invece sia essenzialmente ghiaccio di origine glaciale e quindi il rock glacier sia sostanzialmente un ghiacciaio coperto di detrito. i principali dati a supporto dell’origine glaciale di queste forme riguardano il rinvenimento in numerosi di essi di corpi di ghiaccio massivo i quali, secondo molti autori americani (si veda ad esempio potter et al., 1998), non possono essere spiegati con processi di tipo periglaciale, ma sono il prodotto di un processo di metamorfismo della neve analogo a quello che si verifica sui ghiacciai. numerose indagini hanno 138 r. seppi, a. carton & c. baroni riguardato il rock glacier di galena creek negli stati uniti (potter et al., 1998; steig et al., 1998), ma anche nelle alpi italiane recenti osservazioni hanno dimostrato che in alcune forme riconducibili a rock glacier è presente ghiaccio di origine glaciale (krainer & mostler, 2000; guglielmin et al., 2004; ribolini et al., 2007). un tentativo di sintesi delle diverse interpretazioni sull’origine dei rock glacier è stato proposto da haeberli (2000), secondo il quale, senza tenere conto dell’origine del ghiaccio contenuto nei depositi detritici, è comunque necessario che vi siano permanenti temperature negative nel suolo (permafrost) affinché si possano conservare per millenni masse di ghiaccio nei rock glacier. l’autore afferma anche che molti degli equivoci sono nati da un’errata definizione di ghiacciaio e che spesso quelli che alla testata di molti rock glacier sono stati definiti ghiacciai (e che in seguito possono essere inglobati nel corpo del rock glacier), altro non sono che nevai semipermanenti o glacio-nevati, non costituiti da ghiaccio di origine sedimentaria e privi di una precisa condizione dinamica (trasferimento di massa da una zona di alimentazione a una di ablazione). secondo la classificazione di barsch (1996) possono essere distinti active rock glacier (contenenti ghiaccio e dotati di movimento), inactive rock glacier (contenenti ghiaccio ma non dotati di movimento) e relict rock glacier (privi di ghiaccio e completamente stabilizzati). i primi due, che hanno morfologie molto simili e sono spesso difficilmente distinguibili se non si dispone di misure che documentino l’effettivo movimento del deposito, sono stati raggruppati dallo stesso autore nella categoria degli intact rock glacier (barsch, 1996). tale categoria era stata in precedenza proposta da haeberli (1985) ed è oggi largamente utilizzata. nel presente lavoro è stata adottata la classificazione proposta da barsch (1996), distinguendo i rock glacier in due categorie: a. rock glacier attivi/inattivi; b. rock glacier relitti. sono state utilizzate due sole categorie di forme, allo scopo di differenziare quelle che attualmente contengono permafrost (attive/inattive) da quelle che ne sono prive (relitte), indipendentemente dalle loro condizioni dinamiche. la quota minima raggiunta dai rock glacier viene spesso utilizzata per stimare la quota del limite inferiore del permafrost discontinuo di una regione (barsch, 1996). la presenza di rock glacier relitti mette quindi in evidenza condizioni climatiche diverse da quelle attuali, durante le quali il limite inferiore del permafrost discontinuo si collocava a quote meno elevate rispetto al presente. basandosi su questo concetto, una stima della quota dell’antico limite inferiore del permafrost può essere ottenuta da quella delle fronti delle forme relitte. l’applicazione di questo metodo, tuttavia, deve tener conto di alcuni limiti. i rock glacier, infatti, conservano il pemafrost in modo preferenziale, a causa del particolare regime termico che caratterizza il loro strato più superficiale, costituito da massi privi di matrice (tessitura di tipo openwork). tali substrati, infatti, possono determinare un abbassamento della temperatura media annua della superficiale del suolo fino a 1÷4°c rispetto alle aree coperte da materiale sciolto ricco in matrice fine (harris & pedersen, 1998; juliussen & humlum, 2008). il ghiaccio contenuto in questi depositi può quindi essere localmente trasportato verso valle fino a 300 m più in basso rispetto alla quota media del limite inferiore del permafrost definita a scala regionale e rispetto alle condizioni ambientali che ne consentono l’esistenza (harris & pedersen 1998). è emerso, ad esempio, che nel gruppo adamello presanella, i rock glacier attivi/inattivi, pur contenendo ghiaccio, potrebbero non essere più in equilibrio con l’attuale ambiente morfoclimatico (baroni et al., 2004). l’utilizzo dei rock glacier, tuttavia, consente di ottenere con una buona approssimazione una stima della diffusione spaziale del permafrost di una regione, anche se può indurre a sovrastimarne la presenza (imhof et al., 2000). il gruppo adamello presanella è situato nel settore meridionale delle alpi centrali (45° 54’–46° 19’ n; 10° 21’–10° 53’ e) e si estende su una superficie superiore a 1100 km2 (fig. 1). confina a n con il gruppo ortles cevedale, a e con il gruppo delle dolomiti di brenta e a w con le alpi orobie. le cime più elevate del gruppo superano i 3500 m di quota. dal punto di vista climatico, l’area si trova in una fascia di transizione fra le alpi meridionali, caratterizzate da precipitazioni elevate (f ino a 1800÷2500 mm/anno), concentrate nelle stagione primaverile e autunnale, e la zona interna, caratterizzata da un clima più continentale con precipitazioni concentrate nei mesi invernali e, generalmente, non superiori a 1000÷1200 mm/anno (schwarb et al., 2001). le precipitazioni medie annue per l’area studiata sono comprese tra un minimo di circa 800 mm nel settore settentrionale (stazione meteorologica di ponte di legno, 1200 m s.l.m.) a poco più di 1500 mm nel settore meridionale (stazione meteorologica di bagolino, 800 m s.l.m.) (ceriani & carelli, 2000). la temperatura media annua va da circa 8°c, poco sopra i 1200 m di quota, a circa 0°c ad una quota di poco superiore a 2500 m. il gradiente termico verticale medio per il gruppo montuoso è pari a 0,59°c/100 m (baroni et al., 2004). in questo lavoro vengono presentati i risultati del censimento dei rock glacier relitti del gruppo adamello presanella e sono discusse le relazioni tra la loro distribuzione spaziale e l’antica presenza di permafrost. 2. metodi il censimento dei rock glacier dell’area in esame è stato effettuato mediante l’analisi di fotografie aeree e l’uso di ortofoto digitali. le forme individuate, classificate come attive/inattive o relitte sulla base di numerose caratteristiche morfologiche diagnostiche, sono state digitalizzate in ambiente gis, delimitandole con elementi geometrici di tipo poligonale. la descrizione e la definizione dei principali parametri morfometrici e delle caratteristiche geomorfologiche delle forme censite è stata effettuata tramite fotointerpretazione e interrogazione del gis. le informazioni ottenute sono state perfezionate con verifiche sul terreno. sono state classificate come relitte le forme caratterizzate da: a) morfologia complessivamente attenuata, con corpo appiattito e talvolta con strutture superficiali quali cavità chiuse e depressioni; b) fronte poco ripida; c) ingente copertura vegetale, spesso costituita da arbusti e alberi sparsi (fig. 2); d) suoli evoluti in corrispondenza dell’affioramento di materiale fine. i massi sono caratterizzati da un elevato grado di alterazione, con spigoli arrotondati e superficie scabra per micro139rock glacier relitti e antica distribuzione ... fig. 1 inquadramento geografico del gruppo adamello presanella e ubicazione dei rock glacier relitti. i numeri si riferiscono al catasto dei rock glacier del gruppo adamello presanella (baroni et al., 2004). geographical setting of the adamello presanella group and location of the relict rock glaciers. numbers refer to the rock glacier inventory of the adamello presanella group (baroni et al., 2004). morfoselezione. non sembra costituire una caratteristica diagnostica valida per la distinzione dei rock glacier relitti il grado di colonizzazione dei massi da parte dei licheni crostosi, che può essere molto cospicua anche sui depositi attivi. un’ingente copertura lichenica, ad esempio, è stata osservata su due rock glacier attivi sottoposti a ripetuti monitoraggi topografici che hanno mostrato tassi di spostamento orizzontale fino ad alcuni decimetri all’anno (seppi et al., 2006). un tipico rock glacier relitto esistente nell’area studiata è presentato in figura 3. il settore centrale è caratterizzato da una topografia accidentata e concava, che mostra chiaramente la perdita di volume a seguito della fusione del ghiaccio interno. la superficie è inoltre caratterizzata dalla presenza di numerose cavità chiuse dovute al collasso della massa detritica per fenomeni riconducibili al termocarsismo. 3. risultati e discussione nel gruppo adamello presanella sono stati censiti in totale 216 rock glacier, 128 dei quali (59%) sono stati classificati come relitti (baroni et al., 2004; seppi, 2006). la percentuale di forme relitte è maggiore rispetto a quanto rilevato nelle alpi svizzere occidentali (regione bagnes-hérémence), dove 109 forme su un campione totale di 239 (pari al 46%), sono relitte (lambiel & reynard, 2001). in tutte le alpi svizzere, su un campione di 741 rock glacier, 285 (pari al 38%) sono relitti (frauen140 felder & kääb, 2000). nelle alpi austriache orientali, al contrario, un campione di 1451 rock glacier è costituito da 1169 forme relitte, pari all’81% del totale (krainer & mostler, 2000). per un confronto con l’intero versante alpino italiano ci si deve riferire al catasto dei rock glacier delle alpi italiane (guglielmin & smiraglia, 1997). dei 1594 rock glacier conteggiati in tale catasto, il 59% è stato classificato come inattivo e il 19% come attivo. i rimanenti sono stati considerati ad attività incerta (18%) o complessi (4%). in questo catasto sono stati adottati differenti criteri di classificazione delle forme, che sono state distinte in attive, inattive, ad attività incerta e complesse. confrontando le caratteristiche diagnostiche utilizzate per classificare le forme inattive nel catasto di tutte le alpi (copertura vegetale continua costituita da formazioni erbacee, arbustive e arboree, profilo longitudinale concavo, presenza di cavità chiuse, scarpata frontale poco ripida) con quelle adottate nel catasto del gruppo adamello presanella, è possibile far corrispondere le forme inattive del primo con quelle classificate come relitte nel presente lavoro. la superficie media dei rock glacier relitti del gruppo adamello presanella è pari a 4,1 ha, la lunghezza media è di poco superiore a 290 m e la larghezza media è di circa 180 m. si tratta prevalentemente di forme di tipo tongue shaped (89% del totale) e sono ubicati per lo più su versante (71% del totale). molte forme relitte hanno la fronte più in basso del limite superiore della vegetazione arborea (fig. 2), diversamente dai rock glacier attivi/inattivi, che sono ubicati in prevalenza nella fascia altimetrica della prateria alpina. le forme relitte non mostrano relazioni con ghiacciai, glacio-nevati, nevai semipermanenti, ma alcune di esse sono in relazione con depositi glaciali presenti più a monte. i 128 rock glacier relitti si collocano ad una quota media di poco superiore a 2100 m, con un intervallo di variazione compreso tra 1830 e 2560 m (fig. 4). il rock glacier relitto situato a più bassa quota ha la fronte a circa 1700 m s.l.m. i rock glacier attivi/inattivi sono collocati ad una quota media di circa 2550 m e sono compresi tra una quota minima di 2170 m e una massima di poco superiore ai 2900 m. le forme relitte sono maggiormente rappresentate tra 2100 e 2200 m di quota (n = 34), ma risultano numerose anche tra 1900 e 2100 m e tra 2200 e 2300 m. sono progressivamente meno rappresentate nelle fasce altimetriche superiori a 2300 m s.l.m. le forme attive/inattive sono rappresentate prevalentemente nella fascia altimetrica compresa tra 2500 e 2600 m di quota, ma un considerevole numero di forme è presente anche nelle fasce altimetriche immediatamente superiori e inferiori. la fascia di sovrapfig. 2 esempi di due rock glacier relitti presenti nell’area studiata (a: n 20 di fig. 1; b: n 31 di fig. 1). la fronte supera l’attuale limite degli alberi. examples of two relict rock glaciers in the study area (a: n 20 in fig. 1; b: n 31 in fig. 1). their front is located below the local tree line. fig. 3 topografia superficiale di un tipico rock glacier relitto dell’area di studio (n 146 di fig. 1). la forma mostra numerose cavità dovute a processi di tipo termocarsico. (elaborazione basata su un modello digitale del terreno fornito dalla provincia autonoma di trento). surface topography of a typical relict rock glacier of the study area (n 146 in fig. 1). the landform shows numerous thermokarst-like hollows. r. seppi, a. carton & c. baroni 141 posizione tra forme attive/inattive e forme relitte è compresa tra 2100 e 2600 m di quota (fig. 5). in tabella 1 sono mostrate le quote minime raggiunte dai rock glacier attivi/inattivi e relitti in rapporto all’esposizione del versante. considerando globalmente le forme censite, la quota minima di quelle relitte si colloca circa 430 m più basso di quelle attive/inattive, con rilevanti differenze a seconda dell’esposizione del versante (tab. 1). la differenza di quota è di poco più di 470 m per le forme collocate sui versanti meridionali (s, se e sw) e di circa 450 m per quelle situate sui versanti settentrionali (n, ne e nw). il grafico di distribuzione dei rock glacier in funzione della quota della fronte e dell’esposizione mostra come la maggior parte di essi (sia attivi/inattivi che relitti) sia collocato su versanti esposti a nw, ne, e e w, mentre sono relativamente scarse le forme esposte a n e a s (fig. 6). questa distribuzione riflette principalmente l’orientamento dei maggiori assi vallivi del gruppo montuoso studiato, disposti in direzione nord-sud. numerose indagini effettuate nelle alpi hanno messo in evidenza che i rock glacier attivi/ inattivi hanno al massimo un’età di alcune migliaia di anni e si sarebbero formati nelle fasi più fredde e secche dell’olocene. datazioni 14c di forme attive effettuate nelle alpi ital iane hanno fornito età massime di circa 5000 anni bp (dramis et al., 2003). i rock glacier relitti, invece, risalirebbero ai principali stadi del tardoglaciale. in particolare, numerosi autori hanno attribuito alle più antiche forme relitte di molte aree alpine un’età corrispondente alle fasi tardoglaciali di older dryas (daun auct., van husen 1997), mentre le forme relitte più recenti sono state attribuite alla fase del younger dryas (egesen auct., van husen, 1997) (kerschner, 1980; kerschner, 1985; sailer & kerschner, 1999; frauenfelder & kääb, 2000; frauenfelder et al., 2001; lambiel & reynard, 2001). confrontando la distribuzione dei rock glacier rel itt i del gruppo adamello presanella con i limiti raggiunti dai ghiacciai nei principali stadi tardoglaciali forniti da castiglioni (1961), si può osservare che la maggior parte di essi (87 su 128) si trova nelle aree occupate dai ghiacciai nello stadio di gschnitz e quindi si sarebbero sviluppati successivamente a questa fase del tardoglaciale. soltanto 10 rock glacier sono situati nelle aree occupate dai ghiacciai fig. 4 intervallo di quota dei rock glacier attivi/inattivi e relitti. altitudinal range of active/inactive and relict rock glaciers. fig. 5 numero di rock glacier attivi/inattivi e relitti suddivisi per fasce altimetriche. number of active/inactive and relict rock glacier in the different altitudinal belts. tab. 1 differenza di quota media della fronte dei rock glacier attivi/inattivi e relitti in funzione dell’esposizione. difference in average elevation of the front of active/inactive and relict rock glaciers in relation to the exposure. rock glacier relitti e antica distribuzione ... 142 nello stadio di daun e quindi si sarebbero sviluppati in una fase più recente dei precedenti. dallo stesso confronto, inoltre, emerge come 31 rock glacier sono collocati esternamente ai limiti raggiunti dai ghiacciai nello stadio di gschnitz e non è quindi possibile, per essi, definire una approssimativa età minima a partire dalla quale si sono sviluppati. per i rock glacier relitti dell’area studiata non si dispone, allo stato attuale, di datazioni assolute che possano definirne in modo preciso l’età. secondo il modello della criosfera alpina proposto da haeberli (1985), che si basa su dati raccolti nelle alpi centrali e prende in considerazione la temperatura media annua dell’aria e la quantità di precipitazioni medie annue, il limite inferiore del permafrost discontinuo dovrebbe coincidere, a scala regionale, con la quota dell’isoterma media annua di -1/-2°c. questo modello può consentire di effettuare una stima di massima della diffusione del permafrost in una regione alpina, ma va utilizzato con le dovute precauzioni, in quanto è noto che, a scala locale, altri fattori oltre la temperatura media annua e le precipitazioni determinano la presenza e la conservazione del permafrost. fra questi, i più importanti sono la radiazione solare diretta, l’ammontare delle precipitazioni nevose, la distribuzione della neve al suolo e la sua durata nel corso dell’anno. come già evidenziato in precedenza, nel caso dei depositi detritici ha un ruolo fondamentale la granulometria del materiale di copertura. tali fattori possono determinare temperature medie annue del suolo sensibilmente inferiori a quelle dell’aria (humlum, 1997; harris & pedersen, 1998). sulla base della distribuzione dei rock glacier attivi/inattivi, ipotizzando che essi siano ancora in equilibrio con l’attuale ambiente morfoclimatico, nel gruppo adamello presanella il permafrost dovrebbe attualmente essere presente ad una quota superiore a 2500 m s.l.m. e raggiungerebbe quote sensibilmente inferiori sui versanti esposti a nw (2420 m s.l.m.) e a ne (2430 m s.l.m.). la scarsità di forme attive/inattive rivolte a n non consente di ottenere una stima significativa della quota del limite inferiore del permafrost sui versanti con questa esposizione. la distribuzione delle forme relitte indica un antico limite inferiore del permafrost collocato circa 430 m più in basso rispetto al l imite attuale. escludendo i versanti esposti a n, dove il numero di rock glacier presenti è scarso, la differenza di quota del limite inferiore del permafrost definito dalla distribuzione delle forme attive/inattive e relitte varia tra 400 m circa per i versanti settentrionali (considerando solo le forme esposte a nw e ne) e 460 m circa per i versanti meridionali (considerando le forme esposte a s, se e sw). di tale entità sarebbe stata quindi la risalita del limite inferiore del permafrost discontinuo, assumendo, analogamente a quanto verificato in altri settori delle alpi, che la fase di inattivazione dei rock glacier attualmente relitti si sia verificata tra il tardoglaciale e l’inizio dell’olocene. utilizzando il gradiente termico calcolato per il gruppo adamello presanella, pari a 0,59°c/100 m (baroni et al., 2004), è possibile stimare la variazione di temperatura media annua che corrisponde alla differenza riscontrata fra la quota media della fronte delle forme attive/inattive e quelle relitte. applicando il gradiente e assumendo che esso non sia cambiato nel tempo, la differenza di quota corrisponderebbe a una differenza di temperatura media annua pari a circa 2,5°c. tale differenza scende a 2,4°c sui versanti esposti a settentrione e sale a 2,7°c su quelli esposti a meridione. questi dati consentono di avere una stima approssimativa della variazione di temperatura media annua fra il tardoglaciale (durante il quale i rock glacier attualmente relitti erano probabilmente attivi) ed il presente. la variazione di temperatura ottenuta dalla differenza di quota delle fronti dei rock glacier concorda con l’attribuzione cronologica delle forme relitte alle ultime fig. 6 distribuzione dei rock glacier attivi/inattivi e relitti in funzione dell’esposizione e della quota della fronte. distribution of active/inactive and relict rock glaciers relative to the exposure and the altitude of the front. r. seppi, a. carton & c. baroni fasi tardoglaciali. maisch (1982) indica infatti una diminuzione di circa 2°c ± 0,3°c tra la piccola età glaciale (peg) e le minime temperature delle fasi stadiali di daun ed egesen che, associate ad una variazione di 0,7°c (stimata tra la peg ed oggi per un innalzamento del limite delle nevi di circa 120 m) porta ad un valore di temperatura di 2,7°c. la variazione di temperatura riscontrata nel gruppo adamello presanella è paragonabile a quella di altre aree alpine. nelle alpi austriache occidentali, ad esempio, la quota della fronte dei rock glacier era più bassa di circa 400 m rispetto all’attuale nelle ultime fasi del younger dryas (egesen iii), suggerendo una temperatura media annua più bassa di circa 3°c rispetto al presente (sailer & kerschner, 1999). nelle alpi svizzere, sulla base della distribuzione dei rock glacier relitti, è stato stimato un abbassamento della quota minima del permafrost di 500÷600 m durante il younger dryas, corrispondente a una temperatura media annua inferiore di almeno 3°c rispetto all’attuale (frauenfelder et al., 2001). in belloni et al. (1993), viene messo in evidenza come nelle alpi italiane la differenza fra la quota media della fronte dei rock glacier attivi e quelli inattivi (che per i diversi criteri di classificazione possono essere raffrontati con i rock glacier relitti del presente lavoro) sia di 395 m, corrispondente ad una differenza di temperatura media annua di circa 2,4°c (gradiente adottato: 0,6°c/100 m). i dati ottenuti da belloni et al. (1993) sono quindi in accordo con quelli del presente studio, pur tenendo in considerazione i differenti criteri di classificazione delle forme e i diversi metodi applicati per trattare i dati climatici. 4. conclusioni l’uso dei rock glacier come indicatori della presenza di permafrost negli ambienti alpini può fornire una prima stima della sua distribuzione, sia attuale (forme attive/inattive) che antica (forme relitte). la compilazione di un inventario completo dei rock glacier del gruppo adamello presanella ha consentito di stimare una quota del limite inferiore del permafrost discontinuo che attualmente si colloca a circa 2500 m s.l.m. le forme relitte suggeriscono un antico limite collocato circa 430 m più in basso, ad indicare condizioni climatico-ambientali considerevolmente diverse rispetto alle attuali. è possibile infatti stimare una differenza di temperatura media annua di 2,4/2,7°c tra il presente e il periodo nel quale i rock glacier attualmente relitti sarebbero entrati nella fase di inattivazione. tale periodo è di difficile definizione in assenza di datazioni assolute delle forme relitte, ma dovrebbe coincidere con gli ultimi stadi del tardoglaciale, in analogia con quanto osservato in altre aree delle alpi. questo dato è supportato anche dal confronto tra la distribuzione delle forme relitte e le superfici dei ghiacciai durante gli stadi di gschnitz e daun, dedotte dalla geometria dei depositi glaciali e riportate in castiglioni (1961). ringraziamenti lavoro eseguito con fondi di ateneo dell’università di padova (ex 60% 2008 e 2009, ricerca dal titolo “l'ambiente glaciale e periglaciale delle alpi orientali”) e prin 2008 (ricerca dal titolo “la degradazione della criosfera nelle alpi centro orientali”) responsabile a. carton. lavoro parzialmente realizzato nell’ambito del progetto europeo alpine space “permanet” (permafrost long term monitoring network). bibliografia baroni c., carton a. & seppi r. (2004) distribution and behaviour of rock glaciers in the adamellopresanella massif (italian alps) – permafrost and periglacial processes, 15, pp. 243-259. barsch d. (1996) rockglaciers: indicators for the present and former geoecology in high mountain environments – springer, berlin, 331 pp. belloni s., carton a., dramis f. & smiraglia c. (1993) distribution of permafrost, glaciers and rock glaciers in the italian mountains and correlations with climate: an attempt to synthesize – in: proceedings of the 6th international conference on permafrost, beijing, china, vol. 1, pp. 36-41. castiglioni g.b. (1961) i depositi morenici del gruppo adamello-presanella con particolare riguardo agli stadi glaciali postwürmiani – memorie degli istituti di geologia e mineralogia dell’università di padova, 23, 129 pp. ceriani m. & carelli m. (2000) carta delle precipitazioni medie, massime e minime annue del territorio alpino della regione lombardia – direzione generale territorio e urbanistica regione lombardia. dramis f., giraudi c. & guglielmin m. (2003) rock glacier distribution and paleoclimate in italy – in: proceedings of the 8th international conference on permafrost, zürich, switzerland, vol. 1, pp. 199-294. frauenfelder r. & kääb a. (2000) towards a palaeoclimatic model of rock-glacier formation in the swiss alp – annals of glaciology, 31, pp. 281-286. frauenfelder r., haeberli w., hoelzle m. & maisch m. (2001) using relict rockglaciers in gis-based modelling to reconstruct younger dryas permafrost distribution patterns in the err-julier area, swiss alps – norsk geografisk tidsskrift-norwegian journal of geography, 55, pp. 195-202. guglielmin m. & smiraglia c. (eds). (1997) catasto dei rock glaciers delle alpi italiane – archivio del comitato glaciologico italiano, 3, 103 pp. guglielmin m., camusso m., polesello s. & valsecchi s. (2004) an old relict glacier body preserved in permafrost environment: the foscagno rock glacier ice core (upper valtellina, italian central alps) – arctic, antarctic, and alpine research, 36, pp. 108-116. haeberli w. (1985) creep of mountain permafrost: internal structure and flow of alpine rock glaciers – mitteilung der vaw/eth, 77, 119 pp. haeberli w. (2000) modern research perspective relating to permafrost creep and rock glaciers: a discussion – permafrost and periglacial processes, 11, pp. 290-293. harris s.a. & pedersen d.e. (1998) thermal regimes beneath coarse blocky materials – permafrost and 143rock glacier relitti e antica distribuzione ... periglacial processes, 9, 107-120. humlum o. (1997) active layer thermal regime at three rock glaciers in greenland – permafrost and periglacial processes, 11, pp. 189-206. imhof m., pierrehumbert g., haeberli w. & kienholz h. (2000) permafrost investigation in the schilthorn massif, bernese alps, switzerland – permafrost and periglacial processes, 11, pp. 189-206. juliussen h. & humlum o. (2008) thermal regime of openwork block fields on the mountains elgåhogna and sølen, central-eastern norway – permafrost and periglacial processes, 19, pp. 1-18. kerschner h. (1980) outline of the climate during the egesen advance (younger dryas, 11000-10000 bp) in the central alps of the western tyrol, austria – zeitschrift für gletscherkunde und glazialgeologie, 16, pp. 229-240. kerschner h. (1985) quantitative palaeoclimatic inferences from lateglacial snowline, timberline and rock glaciers data, tyrolean alps, austria – zeitschrift für gletscherkunde und glazialgeologie, 21, pp. 363-369. krainer k. & mostler w. (2000) reichenkar rock glacier: a glacier derived debris-ice system in the western stubai alps, austria – permafrost and periglacial processes, 11, pp. 267-275. lambiel c. & reynard e. (2001) regional modelling of present, past and future potential distribution of discontinuous permafrost based on a rock glacier inventory in the bagnes-hérémence area (western swiss alps) – norsk geografisk tidsskrift-norwegian journal of geography, 55, pp. 219-223. maisch m. (1982) zur gletscher und klimageschichte des alpinen spätglazials – geographica helvetica, 2, pp. 93-104. potter n. jr, steig e.j., clark d.h., speece m.a., clark g.m. & updike a.b. (1998) galena creek rock glacier revisited-new observations on an old controversy – geografiska annaler, 80a, pp. 251-265. ribolini a., chelli a., guglielmin m. & pappalardo m. (2007) relationships between glacier and rock glacier in the maritime alps, schiantala valley, italy – quaternary research, 68, pp. 353-363. sailer r. & kerschner h. (1999) equilibrium-line altitudes and rock glaciers during the younger dryas cooling event, ferwall group, western tyrol, austria – annals of glaciology, 28, pp. 141-145. schwarb m., daly c., frei c. & schär c. (2001) mean annual precipitation throughout the european alps 1971-1990 – in: hydrological atlas of switzerland. landeshydrologie, bundesamt für wasser und geologie, bern, tavola 2.6. seppi r. (2006) i rock glaciers delle alpi centrali come indicatori ambientali (gruppo adamello-presanella e settore orientale del gruppo ortles-cevedale) – tesi di dottorato, università di pavia, 199 pp. seppi r., baroni c., carton a & bassi l. (2006) – caratteristiche morfodinamiche di due rock glaciers attivi nel gruppo adamello-presanella – studi trentini di scienze naturali acta geologica, 81, pp. 75-85. steig e.j., fitzpatrick j.j., potter n. & clark d.h. (1998) the geochemical record in rock glaciers – geografiska annaler, 80a, pp. 277-286. van husen d. (1997) lgm and late glacial fluctuations in the eastern alps – quaternary international, 38/39, pp. 109-118. 144 ms. ricevuto il 17 giugno 2009 testo definitivo ricevuto il 31 luglio 2009 ms. received: june 17, 2009 final text received: july 31, 2009 r. seppi, a. carton & c. baroni amq_27(2) 21 post edi available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 27 (2), 2014, vii xi report 0n the field-workshop on lower-middle plestocene transition in italy (workshop in bari, october 11th, 2014; field-trip october 12th-13th, 2014) neri ciaranfi dipartimento di scienze della terra e geoambientali, università degli studi “aldo moro”, bari, italy corresponding author: neri ciaranfi <neri.ciaranfi@yahoo.it> abstract: the report which presents the results of the workshop field-trip on “lower-middle pleistocene transition in italy” was organized by aiqua and by ics subcommission on quaternary stratigraphy and sponsored by the earth and environmental sciences department of university “a. moro” of bari. the workshop focuses on the presentation and discussion of the main results obtained from multidisciplinary scientific studies carried out on two italian stratigraphic marine sections candidate to represent the gssp of lower-middle pleistocene transition (montalbano jonico in basilicata and valle di manche in calabria). a short presentation of a third gssp candidate (chiba section in japan) was also planned. therefore two significant lower-middle pleistocene lacustrine intrapenninic successions (s.lorenzo in sant’arcangelo basin in south italy and sulmona paleolake basin in central italy) have been illustrated. the field-trip was organized in a two-day excursion in order to visit the above-mentioned sections. keywords: marine sections, lower-middle pleistocene transition 1. introducing the aiqua-inqua workshop the organization of this scientific event was suggested by the inqua international commission on stratigraphy subcommission on quaternary stratigraphy to the aim of having a complete picture on the multidisciplinary studies carried out on the two gssp italian sections candidate to represent the early-middle pleistocene transition. the organization of the field-workshop was made possible through the precious help of maria marino, angela girone, patrizia maiorano, adele bertini and salvatore gallicchio and, for the valle di manche section, of luca capraro. additional help in preparing field-trip was offered by the mayor of montalbano jonico and his staff. 2. workshop program the workshop was held in bari on october 10th, 2014: its main purpose was to present the state of the art of the two italian gssp sections candidate to represent the earlymiddle pleistocene transition; during the workshop the presentation of the studies on the third gssp candidate (chiba section in japan) was also planned together with the illustration of the main features of the two early-middle pleistocene sequences in the continental environment of san lorenzo paleolake (basilicata) and sulmona paleolake (abruzzes). all the presentations took place at the department of earth and environmental sciences of “aldo moro ”university in bari. more than 30 scientists, mostly quaternary stratigraphers and paleontologists attended the meeting. 2.1 the workshop was opened by two introducing presentations whose main purpose was defining the fig. 1 location of the two italian candidate early-middle pleistocene gssp sections in basilicata (montalbano jonico) and in calabria (valle di manche) and the lacustrine coeval succession in sant’arcangelo basin. primary requirements of middle pleistocene gssp and summarizing the early-middle pleistocene transition features during the marine isotope stage 19. they are: 1 head m.j. defining the lower-middle pleistocene gssp: procedures, practicalities, and pitfalls; 2head m.j., gibbard p.l. the early-middle pleistocene transition: latest developments and emphasis on marine isotope stage 19. 2.2 a second group of presentations, concerning the results of the more recent studies on the montalbano jonico section, includes: 3 ciaranfi n., aiello g., barra d., bertini a., gallicchio s., girone a., lirer f., maiorano p., marino m., petrosino p., toti f. the montalbano jonico section in the south apennines foredeep (italy): a reference for the early-middle pleistocene transition; 4 petrosino p., jicha b.r., mazzeo f.c., ciaranfi n., girone a., maiorano p., marino m. the montalbano jonico marine succession: an archive for distal tephra layers at the early-middle pleistocene boundary in southern italy; 5 bertini a., toti f., ciaranfi n., girone a., maiorano p., marino m. climate stratigraphy across the early-middle pleistocene boundary from palynological data of the montalbano jonico section (south italy); 6 toti f., bertini a. vegetation and climate changes throughout the montalbano jonico section to mis 18 up to mis 16: new insights and preliminary results. on the whole the presentations revealed a complete picture of the present-day knowledge about various interdisciplinary investigations especially carried out on mis 18-21 time interval, with particular regard to paleoclimatic evolution of mis 19 which includes the m/b paleomagnetic reversal. 2.3 a third group of presentations, concerning the results of the more recent studies on the valle di manche section, includes: 7 capraro l., macrì p, scarponi d., ferretti p., bellini g., dalan g. the valle di manche section (calabria, southern italy): state of the art, recent advances and future perspectives; 8 scarponi d., capraro l., huntley j.w., macrì p., raffi s. stratigraphic variation of molluscan assemblages across the lower to middle pleistocene transition in the valle di manche section (calabria, southern italy). the presentations mainly concerned new reconstructions of the highresolution δ18o record and the pinning down of the b/m boundary in the section, in addition to the water depth variations between mis 23 and mis 19 put in evidence by changes in the composition of macrobenthic assemblages. 2.4 the last group of presentations includes: 9 suganuma y., kumai h. and other -the chiba section in japan: a reference for early-middle pleistocene transition ; 10 sabato l. the san lorenzo lacustrine succession in the sant’arcangelo basin (south italy): a wonderful record of the early to middle pleistocene in a continental environment; 11 giaccio b., nomade s., sagnotti l., zanchetta g., renne p., scardia g., drysdale r.n., tzedakis p.c., sottili g., sprain c., sposato a., scao v., bassinot f., messina p. the low to middle pleistocene contribution for high resolution record of the sulmona paleolake (abruzzes, italy). 3. field trip program the field-trip was developed in a two-day excurfig. 2 the field-trip participants viii ciaranfi n. sion: the first day, which was totally spent in basilicata, was devoted to the visit of the montalbano jonico section that is well exposed along the internal border of the southern apennines foredeep (fig 2), with particular attention to the “ideale section”, and to a short visit to the continental succession in the s. arcangelo basin. the second day excursion was devoted to the visit to the valle di manche section, near the village of san mauro marchesato in calabria. 3.1october 12th the montalbano jonico village is surrounded by a breathtaking badland landscape of both great panoramic and scientific value. along the western steep slope of montalbano jonico a lower-middle pleistocene composite section has been reconstructed, for a thickness of about 450 m; it extends from mis 37 to mis 16 (from 1240 ka to 645 ka) and consists in muds and muddy silts, from upper slope to shelf environment, which nine volcaniclastic layers (v1-v9) are interbedded to. one of the partial sections (ideale section) contains the transition between early and middle pleistocene (fig. 3). in its upper part δ18o and climaticalpalynological data indicate the location of the mis 19 isotopic stage and 19.1-19.2-19.3 substages, which approximate the brunhes/matuyama boundary, just above v4 layer very close to mis 19.2. this partial section represents a suitable interval for the definition of the gssp (global boundary stratotype section and point) for the ionian stage (middle pleistocene). not far from montalbano jonico the lacustrine succession of s.lorenzo is well exposed in the eastern part of s. arcangelo basin, showing an early-middle pleistocene transition in a continental environment. 3.2 october 13th along the badland just below the cemetery of san mauro marchesato the valle di manche stratigraphic section (fig. 4) is exposed for a thickness of about 50 m. it contains the transition between early and middle pleistocene, which, according to new marine isotope stratigraphy, is marked by the m/b boundary located just before the peak of mis 19. from a lithologic and environmental point of view the sediments around mis 21 and 19 consist in outer-shelf muds, alternated with the shallowing-up silts and sandy silts. a tephra layer, called pitagora ash, outcrops in correspondence with mis 19: this tephra cannot be considered equivalent to v4. the present state of the studies and some differences among the stratigraphic features of the two mafig. 3 the participants at the base of the“ideale section” in montalbano jonico area: the white labels indicate the stratigraphic positions of v3 and v4 tephra layers and those of maximum flooding surface near the m/b boundary. ix lower-middle pleistocene in italy rine sections of montalbano jonico and valle di manche do not allow to establish a robust correlation among these candidate sections. 4. concluding remarks after the end of this event some conclusive remarks have been summarized by the chair of subcommission on quaternary stratigraphy of inqua, about the state of the studies on the two italian gssp candidate sections. in particular the ideale section in montalbano jonico shows detailed foraminiferal and nannofossil biostratigraphy, robust pollen and ostracods paleoclimatic data, δ18o isotope stratigraphy with mis 19 and its substages (19.1/19.3) well identified, astronomical calibration, nine tephra layers (v1-v9) all geochemically well defined and two of them (v3-v4) 39ar/40ar dated. the good preservation of the section and its easy access are guaranteed by the insertion of the section into a “special natural reserve of montalbano jonico badlands” instituted with the law 3/11 by the basilicata region. furthermore the lower part of the montalbano jonico section together with the vrica section in calabria could represent a unit stratotype for the calabrian stage. the valle di manche section shows the matuyama -brunhes reversal just before mis 19, detailed foraminifer and nannofossil biostratigraphy, pollen assemblages, paleoclimatic data, δ18o stratigraphy, good chronology around m/b boundary and a good exposure. references capraro l., asioli a., backman j., bertoldi r., channell j. e. t., & massari f. et al. (2005) climatic patterns revealed by pollen and oxygen isotope records across brunhes-matuyama boundary in the central mediterranean (southern italy). in m. j. head & p. l. gibbard (eds.) early middle pleistocene transitions: the land-ocean evidence. london geological society, special publication 247, 159-182. capraro l., vai g.b., backman j., channel j.e.t., massari f., rio d., scarponi d., sgavetti m., tateo f. (2014) the valle di manche section (calabria, southern italy): a candidate section for the gssp of the ionian stage (middle pleistocene subseries). strati 2013, 915-917, springer geology. ciaranfi n., d’alessandro a., girone a., maiorano p., marino m., soldani d., stefanelli s. (2001) pleistocene sections in the montabano jonico area and the potential gssp for early-middle pleistocene in the lucania basin (southern italy). mem. sc. geol. dell’ univ. di padova, 53, 67-83. ciaranfi n., lirer f., lirer l., lourens l.j., maiorano p., marino m., petrosino p., sprovieri m., stefanelli s., brilli m., girone a., joannin s., pelosi n., vallefuoco m. (2009) integrated stratigraphy and astronomical tuning of the lower-middle pleistocene montalbano jonico section (southern italy). quaternary inter., 219, 109-120. ciaranfi n., aiello g., barra d., bertini a., girone a., maiorano p., marino m., petrosino p. (2014) the montalbano jonico section (southern italy): a candidate for the gssp of the ionian stage (lower -middle pleistocene boundary). strati 2013, 239242, springer geology. maiorano p., capotondi l., ciaranfi n., girone a., lirer f., marino m., pelosi n., piscitelli a. (2010) vricafig. 2 the valle di manche section. the red line indicate the transition between early and middle pleistocene x ciaranfi n. crotone and montalbano jonico sections: a potential unit-stratotype for the calabrian stage. episodes, 33, 218-233. massari, f., capraro, l., rio, d. (2007) climatic modulation of timing of systems-tract development with respect to sea level changes (middle pleistocene of crotone, calabria, southern italy). journal of sedimentary research, 77, 461-468. sagnotti l., cascella a., ciaranfi n., macrì p., maiorano p., marino m., taddeucci j. (2010) rock magnetism and palaeomagnetism of the montalbano jonico section (italy): evidence for late diagenetic growth of greigite and implications for magnetostratigraphy. geophys. jour. int., 180, 1049-1066. xi lower-middle pleistocene in italy ms. received: december 28, 2014 final text received: december 31, 2014 amq abs valente et al tepro 243-246.pub available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 243 246 karst sinkholes formation and spatial distribution: clues from the southern apennines (italy) ettore valente 1, alessandra ascione 1, nicoletta santangelo 1, antonio santo 2 1 dip. di scienze della terra, dell’ambiente e delle risorse (distar), università degli studi di napoli federico ii, napoli, italy 2 dip. di ingegneria civile, edile ed ambientale (dicea), università degli studi di napoli federico ii, napoli, italy corresponding author: e. valente <ettore.valente@unina.it> abstract: sinkholes that affect both carbonate rocks and alluvial plain deposits are widely distributed in the southern apennines. karst sinkholes, in particular, are generally clustered within high sinkhole concentration area (hsca). a geological and geomorphological study of some, selected hsca, has been carried out, aimed at constraining hypotheses on both factors that control sinkhole spatial distribution and causative mechanisms of karst collapses. based on independent evidence on the active tectonic framework and deep fluid rising in the hsca, karst sinkhole phenomena appear related the hypogenic karst controlled by the rise of acidic fluids along active faults. keywords: sinkholes, karst sinkholes, active faults, southern apennines 1. introduction the term sinkhole broadly indicates any mediumsized, sub-circular depression without considering its origin (beck, 1984). the same term is adopted for both karst related and anthropogenic collapses (santo et al., 2011; scotto di santolo et al., 2018). regarding karst sinkholes, a genetic classification has been recently proposed by gutierrez et al. (2008). karst sinkholes occur in the entire southern apennines, however they are densely distributed in specific areas labelled high sinkhole concentration area hsca, sensu santo et al. (2011). recent studies highlight the occurrence of some peculiar geological and geomorphological features in the hsca, such as the occurrence of active faults that are inferred as acting as pathways for the rise of deep fluids (santo et al., 2011, 2017). karst collapse sinkholes are also often associated with gas vents and mineral springs. we have carried out a study aimed at the characterisation of the main geological and geomorphological features of some of the hsca. selected areas are (from the nw to the se) the pratella area, the telese solopaca area and the contursi area (fig. 1). the investigated areas are characterised by the occurrence of mineral and/or thermal springs. furthermore, in all of the investigated areas deep fluid inputs are either testified by gas vents, or inferred from mineralogy and geochemistry of precipitated minerals (ascione et al., 2018; santo et al., unpublished data). we have combined geological and geomorphological investigations aimed at reconstructing local geological setting and at detecting evidence for active faulting in the study areas. the aim of our study is to constrain hypotheses on causative mechanisms of karst sinkhole formation and factors that control karst sinkhole spatial distribution. 2. material and methods the study areas are located in the axial portion of the southern apennines and include the telese solopaca and the contursi area already identified by santo et al. (2011). in addition, the pratella area has been investigated on the basis of the recent paper of ascione et al. (2018). detailed geological and geomorphological investigations have been carried out. the geological analysis was based on the combination of field surveys with stratigraphical data of both published and unpublished boreholes. the latter ones, in particular, provided useful constraints on the spatial distribution and features of both outcropping and buried quaternary deposits. the geomorphological investigation has been based on the analysis of detailed topographic maps (1:5000 scale technical map of the regione campania) and has been addressed to the recognition and mapping of fault controlled features such as fault scarps, triangular facets, river bends, wind gaps, water gaps, beheaded valleys, besides sinkholes. the latter have been classified as either karst collapse sinkholes or alluvial plain sinkholes. mineral, sulphurous and hot springs have been also mapped. mineralogical and geochemical data within study areas have been derived from the literature. all of such information has been plotted on a simplified geological map of the southern apennines, in which information on active and capable faults (derived from detailed, local scale, and the ithaca database, http:// sgi.isprambiente.it/geoportal/catalog/content/project/ ithaca.page) and epicentres of moderate to strong earthhttps://doi.org/10.26382/aiqua.2018.aiquaconference quakes has been included. locations of epicentres has been extracted from the parametric catalogue of italian earthquakes (rovida et al., 2016), with the exception of the 280 b.c., 346, 847, 1349, 1456 and 1805 earthquakes, whose locations are from galli & naso (2009). 3. results 3.1 pratella area the pratella area (box a in fig. 1) is located to the southwest of the matese ridge. the pratella area is characterised by carbonate hills, whose elevations range between 300 and 500 m a.s.l., which are dissected by the lete river valley. in the pratella area, the lete mineral spring is located. the carbonate hills of the pratella area are interposed between quaternary lacustrine deposits that crop out in the ciorlano area, to the north, and ailano area, to the south. quaternary lacustrine deposits in the areas of ailano and ciorlano form terraces that are dissected and eroded at variable degrees, whose elevation ranges between 230 and 280 m a.s.l. geological, geomorphological and stratigraphical data allowed the recognition of several extensional fault strands with evidence of activity in the late quaternary, with prevailing e-w and n-s orientations that affect both the carbonates and the alluvial deposits (ascione et al., 2018). karst sinkholes in the pratella area are clustered along the carbonate hills. they are mainly distributed along an e-w direction, and are aligned with some active fault strand. the lacustrine basins of ciorlano and ailano are characterised by several gas vents and diffuse gas emission. the spatial distribution of the gas vents and gas emissions shows alignments that are consistent with orientation of active faults (ascione et al., 2018). geochemical data point to strong co2 emission, which is among the highest gas emissions in non-volcanic 244 fig. 1 spatial distribution of sinkholes in the southern apennines plotted on a simplified geological map (modified from santo et al., 2011 and ascione et al., 2013). white boxes indicate hsca investigated in this study. a: pratella area; b: telese solopaca area; c: contursi area. valente e. et al. 245 areas in the world (ascione et al., 2018). isotopic analyses of c in the co2 suggest a crustal origin of the emitted gas, probably due to thermo-metamorphism of buried apulian carbonates triggered by buried magmatic bodies (ascione et al., 2018). 3.2. telese solopaca area the telese solopaca area (box b in fig. 1) is located to the north of the mt. camposauro massif. the latter consists of carbonate rocks and is bounded to the north by a wide piedmont area made up of slope and alluvial fan deposits interbedded with tephra layers. the calore river valley limits the camposauro northern slope and its piedmont to the north (amato et al., 2018). the solopaca village falls in this area, whereas the telese village is located at the base of mt. pugliano, an isolated carbonate hill located to the northeast of solopaca. amato et al. (2018) point to the occurrence of several normal faults with evidence of activity in the late quaternary. active fault strands affect the entire camposauro piedmont and the telese area, and are mainly e-w and ne-sw trending. sinkholes occur in the surrounding of both the solopaca and telese villages. sinkholes in the solopaca area affect the alluvial fan conglomerates. they are nesw aligned and placed close to some of the ne-sw trending active faults, while sinkholes in the telese area affect the top surface of mt. pugliano, and are also aligned with fault strands. here, thermal spring of telese and large travertine bodies also occur, with �13c isotopic values of the carbonates indicating a crustal contribution (santo et al., 2011; ascione et al., 2014). mineralogical and geochemical analyses of gypsum rich cursts/patina precipitated close to telese hot springs and inside the sinkholes have been carried out by santo et al. (2018). isotopic analyses of �34s and �18o indicate a deep origin of sulphate leading the authors to hypothesize the presence of a deep-seated sulphur source. 3.3. contursi area the contursi area (box c in fig. 1) is dominated by the ~1600 m high mt. marzano carbonate massif which is bounded, to the south, by san gregorio magno and buccino intramontane basins, filled by late quaternary fluvio-lacustrine deposits. several evidences of recent faulting have been identified in these area, resulting in few km long fault strands affecting both the mt. marzano and the adjoining intramontane basins (ascione et al., 2013). sinkholes have been identified along the carbonate southern slope of mt. marzano and related alluvial fans. in addition, sinkholes affect the top surface of mt. pruno close to contursi village. here, a thermal hot spring is also present. their distribution is consistent with some of the active fault strands recognized by ascione et al. (2013) and santo et al. (2011). santo et al. (unpublished data) carried out a detailed mineralogical investigation of limestones and related precipitates close to sinkhole and mineral spring. the author found isotopic composition of s and o compatible with a deep source. 4. discussion and conclusions karst sinkholes are widespread in the southern apennines, and in several instances are found close to active faults. in some cases, such as the pianelle sinkhole along the southern slope of mt. marzano, their formation is linked to seismic shaking related to high magnitude earthquakes (santo et al., 2011; unpublished data). independent mineralogical and geochemical evidence from the investigated hsca highlights the occurrence, in the surroundings of the karst sinkholes, of both co2 emissions and strongly weathered carbonate rocks associated with diffuse precipitation of sulphure-rich minerals (ascione et al., 2018; santo et al., unpublished data). gas vents are also found within or close to the hsca (ascione et al., 2018), even if their distribution is strongly controlled by the rock-type, being clustered where clayey rocks crop out. isotopic composition of both gas emission and precipitates point to a crustal origin of rising fluids, triggered by the presence of buried magmatic bodies (ascione et al., 2018; santo et al., unpublished data). overall scenario from the investigated hsca suggests that enhanced dissolution that originates karst sinkholes is triggered by the presence of acidic (co2 and/or h2s rich) fluids. clustering of karst sinkhole phenomena appears related with localised hypogene karst controlled by the rise of acidic fluids conveyed towards the surface by active faults. references amato v., aucelli p.p.c., cesarano m., filocamo f., leone n., petrosino p., rosskopf c.m., valente e., casciello e., giralt s., jicha b. (2018) geomorphic response to late quaternary tectonics in the axial portion of the southern apennines (italy): a case study from the calore river valley. earth surface processes and landforms. doi: 10.1002/esp.4390. ascione a., mazzoli s., petrosino p., valente e. (2013) a decoupled kinematic model for active normal faults: insights from the 1980, ms = 6.9 irpinia earthquake, southern italy. geological society of america bulletin, 125 (7-8), 1239-1259. ascione a., iannace a., imbriale p., santangelo n., santo a. (2014) tufa and travertines of southern italy: deep seated, fault related co2 as the key control in precipitation. terra nova, 26 (1), 1-13. ascione a., ciotoli g., bigi s., buscher j., mazzoli s., ruggiero l., sciarra a., tartarello m.c., valente e. (2018) assessing mantle versus crustal sources for non-volcanic degassing along fault zones in the actively extending southern apennines mountain belt (italy). geological society of america bulletin. doi:10.1130/b30814.1, in press. beck b.f. (1984) sinkholes, their geology, engineering and environmental impact. proceedings of the first multidisciplinary conference on sinkholes, orlando, fl. a.a. balkema publisher, rotterdam, netherlands, pp. 429. galli p., naso g.a. (2009) unmasking the 1349 earthquake source (southern italy): paleoseismological and archaeoseismological indications from the karst sinkholes formation and spatial distribution aquae iuliae fault. journal of structural geology. 31, 128-149. gutiérrez f., guerrero j., lucha p. (2008) a genetic classification of sinkholes illustrated from evaporite paleokarst exposure in spain. environmental geology, 53, 993-1006. rovida a., locati m., camassi r., lolli b., gasperini p. (2016) cpti15, the 2015 version of the parametric catalogue of italian earthquakes. istituto nazionale di geofisica e vulcanologia. doi: 10.6092/ingv.it-cpti15. santo a., ascione a., del prete s., di crescenzo g., santangelo n. (2011) collapse sinkholes distribution in the carbonate massifs of central and southern apennines. acta carsologica, 40, 95-112. santo a., budetta p., forte g., marino, e., pignalosa a. (2017) karst collapse susceptibility assessment: a case study on the amalfi coast (southern italy). geomorphology, 285, 247-259. santo a., santangelo n., balassone g., strauss h. (unpublished data) hypogene karst as the key agent of high sinkhole concentration areas (southern apennines, italy): mineralogical and geochemical constraints. earth surface processes and landforms, (submitted). scotto di santolo a., forte g., santo a. (2018) analysis of sinkhole triggering mechanisms in the hinterland of naples (southern italy). engineering geology, 237, 42-52. 246 valente e. et al. ms. received: april 28, 2018 final text received: may 16, 2018 amq32(2) 167-184 amezcuabuendía et al.pub beyond, a new tool for sapropel s1 studies in the mediterranean sea rubén amezcua-buendía 1, claudia diamantini 2, domenico potena 2, alessandra negri 1 1 department of life and environmental sciences. polytechnic university of marche, ancona, italy. 2 department of information engineering. polytechnic university of marche, ancona, italy. corresponding authors: r. amezcua-buendía <r.amezcua@pm.univpm.it> and d. potena <d.potena@univpm.it> abstract: science advances and, with it, the storage of large amounts of data. the need to use this data efficiently, quickly and safely is possible thanks to the big data analytics (bda) that allows us to store and relate data in order to obtain new knowledge. in this paper we present and explain how we constructed the new database, “beyond”, that provides a wide variety of organized and standardized paleoproxies relative to the past 20.000 years of mediterranean sea history. beyond makes available to all researchers the possibility to extract and analyze data. we focused on a specific interval of time corresponding to the deposition of the most recent sapropel (s1) and the potential uses offered by the tool. beyond contains 126 sediment cores data from 79 scientific papers and a total of 1.678 different proxy related data that have been categorized in: geochemistry, isotopes, pollen, sediment grain size, coccolithophore, dinoflagellate and foraminifera. our work highlights the development of a new methodology to correlate data, including the cases where data regarding the precise age control for each core was missing. it highlights as well the potential of using data analytics to extract hidden patterns and new knowledge also in the field of paleoceanography. keywords: big data analytics, database, mediterranean sea, sapropel, s1.  available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 32 (2), 2019, 167 184 1. introduction the science of earth and environment has matured through two major phases and it is entering a third one. in the first phase, which ended two decades ago, science was oriented and focused on developing knowledge in geology, atmospheric chemistry, oceanography, ecosystems, and other fields of the earth system. in the 1980s, the scientific community began to investigate these disciplines as interacting elements of a single system. in this second phase, we started to understand complex phenomena such as climate change, which links concepts from atmospheric and oceanic science, biology, and human behavior. in the emerging third phase, knowledge developed primarily for the purpose of scientific understanding, is being completed with the new knowledge created through data science and applications that allow us to acquire, manage, and make available data that helps us to take action and practical decisions (dozier & gail, 2009). nowadays, one of the most challenging tasks in earth science is the possibility to use the vast amount of literature data by means of the new technology often referred to as the simple word big data. big data analytics (bda) allows to explore huge volumes of data, coming from heterogeneous data sources, in order to extract novel, useful and human understandable knowledge. to this end, bda refers to methodologies coming from several research areas, like machine learning, data mining, statistics, artificial intelligence and database (gandomi & haider, 2015). the amount of data available nowadays is really huge and as by ibm, 90% of the data have been added in the last 2 years (ibm marketing cloud, 2017). most scientific disciplines could be described as small data, or even data poor. therefore, in these fields most of the experiments or studies are based on few data points. many disciplines in geological sciences like palaeoceanography, paleoclimatology fall among them. however, although each single study is based on relatively few data, the whole set of studies potentially offers a considerable amount of data, provided that we are able to collect and correlate them. bda technologies can provide us the toolsets to integrate these different data sources, organize them in a database, that supports data analysis. in the last years many data have been stored and made accessible in several fields of research, including natural hazards (e.g., em-dat https://www.emdat.be/), c h e m i s t r y ( e . g . , c h e m s p i d e r h t t p : / / www.chemspider.com/), biology (e.g., genbank https:// www.ncbi.nlm.nih.gov/genbank/); as for the paleo studies domain, several databases are under construction and implementation and among them, the best known are pangaea (https://www.pangaea.de/), noaa ( h t t p s : / / w w w . n c d c . n o a a . g o v / d a t a a c c e s s / paleoclimatology-data/datasets), iodp (http://www https://doi.org/10.26382/amq.2019.11 168 amezcua-buendía r. et al. odp.tamu.edu/database/) and neotoma (https:// www.neotomadb.org/). the pangaea database contains data (geochemistry, isotopes, pollen, sedimentology, stratigraphy, microfossils) georeferenced in time and space regarding all the fields that comprise environmental sciences. the janus database (iodp) stores and retrieves data collected on the drill ship joides resolution, while national centers for environmental information (ncei), that it’s the world’s largest provider of weather and climate data, provides the data to noaa. finally, neotoma database is focused on the paleo data from the pliocene to the quaternary. this variety of databases potentially gives many benefits to researchers but implies the presence of some obstacles too. the availability of a wide variety and quantity of data provides researchers with new possibilities to compare and correlate their data, potentially without the need to perform new measurements. in addition, more accuracy is provided because of the possibility to choose, among many data, those that appear to be more meaningful for a given type of research. nevertheless, there are several difficulties related to the heterogeneity of data sources (e.g., structured and related data in a database or unstructured data provided in the form of publication), the model of the data representation (e.g., xml, json, relational tables…), the forms of access (e.g., apis, search forms, cvs downloads…), and the structure of the data (e.g., it is frequent that studies dealing with the same proxy, express the results in different units). this hinders the ability to correlate data and, therefore, the comparison of results. looking towards the future it is hence critical that the scientific community becomes aware of the necessity to create standards that ensure a universal data format (mckay & emile-geay, 2016) that would increase the quality of the results and decrease the time of reworking them. according to bell (2009) we are at a stage of development that is analogous to when the printing press was invented, and the jim gray’s fourth paradigm, data intensive computing, is in an initial phase but cannot be neglected. data analysis covers a whole range of activities throughout the workflow pipeline, including the use of databases (versus a collection of flat files that a database can access), analysis and modelling, and then data visualization. jim gray’s recipe for designing a database for a given discipline is that it must be able to answer the 20 key questions that the scientist wants to ask. gray called this new paradigm “escience” and characterized it as "it meets scientists". whether you're a scientist or a technologist, this new data-intensive science is fascinating stuff (mcfedries, 2011). the most important problem when using a bda approach in disciplines that use not only areal data, but sediment core data, is the need to uniform data and to refer it to events in time. this additional data type consists in the result of accumulation during time and therefore represents a record of processes occurring through time. project 418 is an esso-managed pilot project which addresses some of earthcube's core activities envisioned for the earthcube cyberinfrastructure (lingerfelt et al., 2018). these activities include resource registration, data discovery, and data access. project 418 will serve as a pilot for the beginning point for these tasks, provide a foundation for future initiatives, as well as become a core component linking data facilities of earthcube funded projects. earthcube supported linkedearth (khider et al., 2018) project. it is a further development helping manifest a better future by creating an online platform that (1) enables the curation of a publicly-accessible database by paleoclimate experts themselves, and (2) fosters the development of community data standards, including an ontology. in turn, these developments enable cuttingedge data-analytic tools to be built and applied to a wider array of datasets than ever possible before, supporting more rigorous assessments of the magnitude and rates of pre-industrial climate change. more information at the linkedearth’s site http://linked.earth show that there is a growing community sharing a key objective: the development of a community standard for paleoclimate data and metadata. the linkedearth cyberinfrastructure also supported the development of the past global changes past 2,000 years project (pages2k). in this contest, emile-geay et al. (2017) used a community-sourced database (pages2k temperature database) including a wide variety of proxies, like marine sediments, lake sediments, glacier ice or trees with the goal to reconstruct the global temperature of the common era. finally, alberico et al. (2017), created the wdbpaleo database that contains paleoclimatic proxies data of marine sediment core with the objective of studying the past climatic and environmental conditions of mediterranean sea. the aim of the present paper is to describe the database beyond (big paleo ocean data), that we have ideated and implemented using paleodata record of the last 20.000 years. method: in order to design the database, we first defined our research questions as: 1. is it possible to correlate data at the minimum level of granularity (namely at sub-sample level), provided that sample range is heterogeneous in different studies? 2. is it possible to correlate proxies at different aggregation levels (e.g., cores from different areas, cores at different depths, proxies of the same core from different papers)? 3. is it possible to support an exploratory data analysis for sapropel s1? as a second step, we analyzed different sources, namely research papers and existing databases, to identify available data, their structure and format. on the basis of collected requirements, beyond has been built following state-of-the-art design methodology, starting from a conceptual design. finally, the database has been populated by extracting, transforming and loading subsets of data from existing databases and, when needed, manually inserting those data published in research papers only. the databases will be described in section 2.1. to manage the different data that derive from dif 169 beyond, a new tool for sapropel s1 studies in the mediterranean sea ferent sources and standards, we used data analytics (da). ridge (2014) defines da as any activity that involves applying analytical processes to data by using computer systems for the purpose of deriving insight from that data. da allows us to explore huge amounts of data with the purpose of extracting new patterns or information that is comprehensible for further study. the objective of this work is to provide researchers, with beyond, a database which integrates heterogeneous paleodata from several sources and allows researchers to extract, correlate and aggregate data through the standard database query language sql. 2. database design     the database design is the data organization according to a database model, which determines its logical structure, that is, the manner in which data can be stored, organized and manipulated. to design our database, it was fundamental to know the data characteristics to be inserted and the goal to achieve with it. yet, how databases are designed is another fundamental information. beyond mainly provides data of the mediterranean sea past 20.000 years history, but our study is focused on a specific interval of time corresponding to the deposition of the most recent sapropel (s1). sapropels were defined by kidd et al. (1978) as sharply-defined, dark-colored sedimentary layers with a corg content >2 wt.% and a thickness >1 cm. the sapropel origin is still matter of discussion, centered on the (1) close relationships between sapropels and fluctuations of the earth’s orbital parameters (hilgen, 1991; lourens et al., 1996; ziegler et al., 2010) and (2) the hydrographic (rohling, 1991, 1994; myers et al., 1998), biogeochemical and ecological changes (sarmiento et al., 1988; kemp et al., 1999; sachs & repeta, 1999; negri & giunta, 2001; principato et al., 2003; gallego-torres et al., 2011) which led to sapropel deposition. over the last decade numerous studies (incarbona et al., 2011; bout-roumazeilles et al., 2013; triantaphyllou, 2014; hennekam et al., 2014; azrieli-tal et al., 2014; mojtahid et al., 2015; tesi et al., 2017) provided more knowledge about sapropel deposition but the debate about its origin is still open. in fact, the scientific struggle between those invoking simple anoxia of the mediterranean sea (olausson, 1961; ryan, 1972; cita et al., 1977; thunell et al., 1977; thunell, 1979; rossignol-strick, 1983, 1985) and those invoking increased export productivity causing anoxia (calvert & price, 1983; pedersen & calvert, 1990) is still unsolved, even if some papers point to a combination of effects (myers et al., 1998; martinez-ruiz et al., 2000; stratford et al., 2000; rohling et al., 2015). 2.1 data sources the starting point for the design of beyond is the study of other already existing databases, and of the literature. the databases used are: pangaea: it is one of the biggest digital data libraries for the earth system science and it has provided us with a large amount of data. all the data derive from marine sediment cores that are georeferenced in space (with latitude, longitude and depth below sea) and in time (geological age). pangaea provides a web interface for initial data search and different formats for data download. noaa (national oceanic and atmospheric administration): it contains current and historical data focused on the conditions of the oceans and atmosphere. the access of the data can be through traditional access methods as web-based or ftp (file transfer protocol) and they mainly provide the data in “.txt” or “.xls” format. janus database: odp (ocean drilling program) and iodp (international ocean discovery program) data are stored in the same database, janus. this database is based on a relational data model and contains marine geoscience data collected onboard the drillship joides resolution. data can be visualized through the janus web site and downloaded in “.txt” format. global pollen database (gpd): it contains data of fossil and modern pollen records from natural archives where data are hosted by noaa. databases such as north american pollen databases (napd) or european pollen database (epd) have been the precursors of this database. neotoma paleoecology database: it is a multiproxy paleoecological database that covers the pliocenequaternary, including modern microfossil samples, and that works like a centralized database with virtual constituent databases (napd, epd, faunmap) and which is implemented through microsoft sql server. data is accessible from neotoma explorer, an interactive web application for searching and downloading data in “.txt” format. of the above databases, we focused our analysis on the portion of data describing marine sediment cores. fig. 1 percentage of cores in beyond, associated with the different proxies in the mediterranean sea. as for the literature analysis, we started searching digital libraries for the following keywords: “sapropel”, “anoxia”, “holocene”, “mediterranean sea” and “productivity”. 2.2 categories of data beyond has been organized around cores, which are geolocated and numbered in order to be identifiable. cores are divided into samples (portion of the core between two discrete depth values) where several proxy measurements have been made in each sample. the proxies inserted in the database are considered as a function of the category (e.g., geochemistry, sedimentology, isotopes…), but also of the method of analysis and measurement unit of the proxy itself. in this regard, the first step has been the categorization of data in geochemistry, isotopes, sedimentology (sediment grain size and composition), palynology and micropaleontology (coccolithophore, dinoflagellate and foraminifera). fig. 1 shows the distribution of proxies in 170 fig. 2 (a) core associated with geochemistry data. (b) diagram showing the geochemistry proxies classification used for the database beyond. fig. 3 (a) core associated with stable isotopes data. (b) diagram showing the stable isotope proxies classification used for the database beyond. amezcua-buendía r. et al. the different cores that have been taken into account. some proxies, especially in geochemistry, show a issues related to the analytical method: in fact different methods can be used for the analysis (e.g., barium has been obtained by inductively coupled plasma atomic emission spectroscopy (icp-aes), inductively coupled plasma mass spectrometry (icp-ms) or x-ray fluorescence (xrf). another problem is the measurement unit of some proxies: in fact, even when the methodology is the same, results can be expressed in different 171 units (e.g., aluminum can be expressed in mg/kg or as a percentage of total weight). geochemistry: in general, the geochemical proxies are very useful in the study of palaeoceanography and paleoclimate. in fact, the chemical composition of the marine sediment provides information about past climates, ocean circulation, sea-floor conditions and changes in the sediment over time (calvert & pedersen, 2007). trace elements fig. 4 (a) core associated with sedimentology data. (b) diagram showing the sedimentology classification used for the database beyond. fig. 5 (a) core associated with palynology data. (b) diagram showing the palynology proxies classification used for the database beyond. beyond, a new tool for sapropel s1 studies in the mediterranean sea provide clues about the aeolian or river input to marine sediments (jimenez-espejo et al., 2007; frigola et al., 2008) while other elements such as barium, aluminum and phosphorus allow to reconstruct marine paleoproductivity (möbius et al., 2010; martinez-ruiz et al., 2015). redox-sensitive elements are used to recognize bottom water conditions (martinez-ruiz et al., 2000; tribovillard et al., 2006; tachikawa et al., 2015; tesi et al., 2017). fig. 2.a shows the position of cores providing geochemical data. a total of 41 cores are located in deep environment of the mediterranean sea. fig. 2.b shows how we categorized the geochemical data according mainly to the measurement methods (icp-aes, icp-ms, aas, xrf, aas-xrf and chn analyzer) and the unit (mg/kg and percentage) in which the proxy data have been expressed. isotopes: stable oxygen and carbon isotope records of benthic and planktonic foraminifera are a powerful tool for 172 fig. 6 (a) core associated with coccolithophore data. (b) diagram showing the coccolithophore proxies classification used for the database beyond. fig. 7 (a) core associated with dinoflagellate data. (b) diagram showing the dinoflagellate proxies classification used for the database beyond. amezcua-buendía r. et al. providing isotopes data and fig. 3.b the categorization of the data that have been measured by a single method (mass spectrometer) and expressed in two different units (‰ pdb and ‰vpdb). sediment grain size and composition: sedimentology helps to comprehend the systems that control paleoclimatic and palaeohydrological changes. the clay mineral study contributes to understanding processes related to oceanic circulation, wind directions, palaeoceanography and paleoclimate studies. the δ18o signal shows fluctuations of global ice volume (grazzini & pierre, 1991; jimenez-espejo et al., 2008), changes in sea salinity (fontugne et al., 1989) and the freshwater input (dubois-dauphin et al., 2017). the δ13c signal provides information about deep water properties and its circulation, organic matter fluxes and carbon cycling of the oceans (woodruff & savin, 1985; zahn et al., 1986; sarnthein et al., 1994; mackensen et al., 2001; kuhnt et al., 2008). fig. 3.a describes the position of the 75 cores 173 fig. 8 (a) core associated with foraminifera data. (b) diagram showing the foraminifera proxies classification used for the database beyond. fig. 9 e-r schema of beyond. beyond, a new tool for sapropel s1 studies in the mediterranean sea precipitations just like the dynamics river inputs (ehrmann et al., 2007, 2016). in addition, the grain size distribution, which is conditioned by physical processes, helps to know the transport processes and source areas (bout-roumazeilles et al., 2013; ehrmann et al., 2007). fig. 4.a shows the positions of the 18 cores associated with the grain size and composition of the sediments, while in fig. 4.b the methods utilized for these cores (laser diffraction, cls, xrf and xrd) and the measurement units (µm and percentage) are reported. palynology: pollen records in marine sediments provide accurate information on paleovegetation, palaeohydrology and paleoclimate on a local and global level. pollen is studied in order to reconstruct changes in temperature and precipitation occurred in the past (kotthoff et al., 2008; langgut et al., 2011) but is also used to investigate processes such as productivity (hennekam et al., 2015). as is evident from fig. 5.a, however very few data (only 6 cores) are available for the investigated interval. fig. 5.b shows the only methodology used for palynology, that correspond to quantitative analysis (counts of pollen grains) (parker & arnold, 1999), and the unit of measurement (pollen grain). coccolithophores: coccolithophores are planktonic microalgae living in almost all oceanic areas. according to the specialists, changes in coccolith abundances permits to assess primary productivity fluctuations and, based on these, water column modifications (negri & giunta, 2001; principato et al., 2003). furthermore, a relation between reworked specimens eroded from continental sediment brought to the ocean by the river runoff is hypothesized by negri et al., 1999 which evidence increased river discharge during sapropel deposition. finally, the presence or absence of selected species allows the recognition of oligotrophic or eutrophic environments (crudeli et al., 2006). fig. 6.a shows the location of the cores (19) reporting coccolithophore data. fig. 6.b shows the methodology of analysis used in coccolithophore studies, that is quantitative on smear slide (bown & young, 1998), whose values are expressed in number of coccolithophore counted or percentage. dinoflagellate: dinoflagellates are a group of unicellular protists that can be identified using the light microscope, and are (usually) recognized by their golden-brown plastids, assimilative cell with indented waist, distinctive swimming patterns, and relatively large nucleus that contains visible chromosomes (carty & parrow, 2015). resting cyst association is closely related with parameters such as temperature, salinity and nutrient concentration (meier et al., 2002, 2004). also, they can give information about oxidation fronts, productivity and bottom oxygen conditions, and through this, on bottom water circulation (zonneveld et al., 2001). dinoflagellate data are scarce as shown fig. 7.a (7 cores). fig. 7.b displays the only method (quantitative analysis) and unit of measurement (cyst) inserted in database. 174 foraminifera: foraminifera are single-celled amoeboid protist comprising the order foraminiferida (or foraminifera of supergroup rhizaria), characterized by reticulating pseudopods and typically a shell. they may be planktonic or benthic, are mainly marine and are found in all marine environments. the study of foraminifera contributes to knowledge of several processes in palaeoceanography, paleoclimate, paleoproductivity and palaeohydrology. the abundance, assemblage and size of planktonic foraminifera are the result of increased or decreased productivity due to hydrological conditions (e.g., water column stratification, turbidity, salinity), climate (e.g., river input, temperature) (principato et al., 2003; triantaphyllou et al., 2010; mojtahid et al., 2015; tesi et al., 2017). benthic foraminifera are indicators of the deep water conditions as oxygen content in the interstitial and bottom water as well as the food supply and availability (schmiedl et al., 1998; kuhnt et al., 2007; abu-zied et al., 2008; gupta et al., 2008). the locations of the 51 cores that have studied the foraminifera data are presented in fig. 8.a. in addition, fig. 8.b shows the two subclasses (planktonic or benthonic). in both subclasses foraminifera are measured by “quantitative analysis” and expressed in three different measurement units (number of foraminifers, percentage or number of foraminifers/gr). 2.3 design methodology the conceptual modelling is a very important phase in designing a quality database (elmasri & navathe, 2010). it provides an abstract representation of the application domain, focusing on the description of the major concepts involved and of their relationships, without being misled by database implementation details. in particular, fig. 9 shows the conceptual schema of the beyond database expressed in the entityrelationship (e-r) model. in the e-r graphical notation, rectangles represent entities, while diamonds represent relationships between entities. entities are conceptual abstractions of a class of real world objects, which in turn are named instances (or occurrences) of the entity (e.g., the entity “core” has the real cores as instances). the description of all entities is reported in appendix a. instances of relationship are n-ples of entity instances that are someway related to each other (e.g., an instance of “core measurement” is a triple whose components are a particular measure or proxy, the particular core where the proxy has been taken, and the particular paper where the measurement has been published). circles associated to entities or relationships represent attributes, e.g., relevant characteristics we want to record about them (e.g., a core is described by its name, latitude and longitude, the date of sampling, etc.). finally, the black circle in each entity represents the identifier, e.g., an attribute whose value uniquely characterizes each entity occurrence (e.g., the coreid). in general, an identifier can be defined through a set of attributes. in some cases, an identifier can not be built using only attributes of the entity, but has to include identifiers of other entities that are linked through relationships. this amezcua-buendía r. et al. latter is the case of the entity “measurement”, which represents the value of a given proxy measured between two depth values of a given core, as reported in a specific research paper. hence, the identifier of “measurement” is formed by two internal attributes representing the start and the end depth of the sample (depthstart and depthend respectively) and the identifiers of “paper”, “proxy” and “core” entities respectively. in turn, an instance of “core” is characterized by both the investigation “project” in which the core has been collected, and the geographical “region” it belongs to. each region is part of an “area”, namely a given sea and zone (e.g., the ionian sea in the eastern mediterranean area). it is worth noting that the concept of “measurement” is central in the beyond schema, since it represents the finest measurement we can store in the database. using relationships, we have defined between “measurement” and other entities, we are able to extract information which is not explicitly stored in the database. for instance, we are able to derive proxies values for a virtual core, namely the aggregation of all cores in a given region or area. furthermore, proxies values can be aggregated on the basis of the core on which they were measured, the category of proxy, and so on. moreover, we can also compare and correlate measurements related to the same sample but reported in different papers, and to the same sapropel but in different cores. examples of application of analysis enabled by beyond are described in section 3. we like to note that the conceptual methodology adopted allows to obtain a compact, normalized, nonredundant schema that still maintains the same expressive capacity and information richness of existing databases. as an example, the problem of the variable "age": pre-existing databases can only correlate data where the age variable has been calculated, while in beyond we can insert data with and without the age variable because we use a different method to correlate them (see section 3). 2.4 implementation beyond has been implemented using the relational model. the adopted database management system is mysql. the schema reported in fig. 10 has been obtained from the e-r schema of fig. 9 by following the rules for e-r to relational schema translation. the database beyond is publicly available at http://beyond.dii.univpm.it/. it is focused on paleoclimatology and palaeoceanography studies where all data have been obtained from marine sediment cores. whenever possible, we extracted and transformed data coming from other existing databases (see section 2.1) and loaded them in beyond. other data have been manually inserted starting from published papers, sometimes directly asking the authors to provide excel files. currently, we have inserted data from: 79 papers; 126 cores (see fig. 11); 1.678 different proxy related data that correspond to all 175 fig. 10 the relational schema of beyond. the key symbols are a primary key, while attributes with a red symbol are foreign keys. beyond, a new tool for sapropel s1 studies in the mediterranean sea the different ways found in literature used to express the same proxy. see tab. 1 that clarifies this concept: e.g., the aluminum element is classified into 10 different ways because authors calculated and expressed the proxy with different methods and units); 283.135 proxy measurements. the reasons for the creation of a new database are: (1) most of the data are available in repositories, like pangaea or noaa, where data can be downloaded as tab-delimited texts but no functionality is provided to query the repository nor to combine data coming from different sources; (2) in literature, all databases are organized according to core-age where all the data are expressed in function to age. in beyond, age is represented as any other proxy, through the concept of “measurement” (see section 2.3), allowing us a greater flexibility. indeed, we are able to store proxies’ values of a (sample of a) core even if the age is not provided. 3. applications to demonstrate the impact of beyond, in this section we show a set of possible applications to the reconstruction of a combined stack relative to a proxy in the s1 interval, supported by advanced analyses based on a rich set of integrated data. in fact, to explain processes across a certain area during a certain interval of time we cannot focus on a single field of research (e.g., geochemistry) but we must relate different studies in order to complement and strengthen different discoveries. for this reason, it is of basic importance that every researcher can access and use the data, but also contribute populating the database with his/her data. furthermore, the creation of the database, allows us to use data analytics, to access and analyze data with the purpose of gaining and discovering useful patterns and trends in large data sets (lussier & hendon, 2016). we have managed to correlate cores located at different depths, presenting different thicknesses, that is to say, different sedimentation rates across the mediterranean sea. these correlations have been carried out by sql queries. we have standardized the depth values of the cores on the basis of the depth values of the sapropel lithology using the following formulas: where depthstart is the top part of the sample (usually of centimetric thickness) analyzed measured starting from the top of the core. analogously, depthend is the base of the sample analyzed. tops1 is the top of the sapropel, while bottoms1 is its base. tab. 2 shows the new depths (standardized start and standardized end) obtained with the use of these formulas. then, the proxy values were averaged in the same standardized depth range. let c1 and c2 be two different cores, let bottom1s1 and top1s1 be the bottom and the top depths measured for s1 of the core ci; let v1(x,y) and v2(x,y) be two functions returning the values of the same proxy measured between depths “x” and “y” on c1 and c2 respectively; let d1 and d2 be the sets of samples depths of c1 and c2 respectively, and let “m” and “p” be the cardinality of d1 and d2 respectively; 176 fig. 11 map of the mediterranean sea with the locations and depths of cores used in beyond. amezcua-buendía r. et al. 177 beyond, a new tool for sapropel s1 studies in the mediterranean sea tab 1. example of the different ways to express the aluminum proxy in beyond. tab 2. example of averaging depth data: coreid is the number identifying the core (1; 2; 3). depthstart and depthend are the beginning and the end of the measured sample starting from the core-top. proxy value is the value obtained in the measured sample for a particular proxy (e. g. toc). top s1 and bottom s1 are the sapropel interval top and base depth respectively. standardized start and standardized end are the new depths obtained with the formulas reported in text. 178 amezcua-buendía r. et al. the function v’(x,y) represents the average values of the proxy measured at normalized depths. as for c1 and c2, we can see v’(x,y) as the function returning values of the considered proxy in the interval [x,y] of a “virtual core” computed as average of c1 and c2 (see fig. 12). here, the value 1 identifies the beginning of sapropel and the value 0 corresponds to the top of it (as indicated by the different authors and therefore it is based on different methods such as color, micropaleontology, geochemistry, etc.). it is noteworthy that this way the ages of the base and the top of the sapropel are not important, because the query provides a stack, combining all the different sapropel thicknesses found in the database. this allows to compare the trend recorded in the different proxies regardless of age as illustrated in the following examples. to demonstrate the effectiveness of different cores correlation for the sapropel interval, we carried out some analysis with beyond. firstly, we evaluated the correspondence between age and standardized depth. fig. 13 considers 37586 age values, of which 22916 in the standardized interval [0,1], from 20 cores. it is evident that the sapropel (s1) interval show a linear trend where r=0.92. hence, a direct correlation between age and standardized depth is observed. then we evaluated the correspondence between toc, age and standardized depth. fig. 14 shows the perfect trend overlay between toc vs age and toc vs standardized depth in the sapropel interval, thus supporting the effectiveness of our correlation method. as for data visualization fig 15. shows the toc (total organic carbon) trend in 24 cores across the eastern mediterranean sea. as it is obvious the difference between inside and outside the sapropel interval is evident. moreover, it must be underlined that these values are the result of the averages calculated among all the cores of the eastern mediterranean sea. for this reason, the plot shows high standard deviations indicating that the data points are spread out over a wide range of values. despite all this, a toc drop around “0,5 fig. 12 standardization of 3 exemplified cores. the intervals s1 are at different depths and the sedimentation rate is different in every core. the green, blue and red dots are the points measured in the cores. start s1 and end s1 correspond to the sapropel base and top respectively. 179 beyond, a new tool for sapropel s1 studies in the mediterranean sea standardized depth” corresponding to the sapropel interruption (rohling et al., 1997; de rijk et al., 1999; myers & rohling, 2000; casford et al., 2003; abu-zied et al., 2008; hennekam et al., 2014) is evident. instead not all the studies cores show this interruption clearly. another example of output is the toc trend, based on the core depth of the cores in the eastern mediterranean sea (fig. 16). cores are shown in four depth interval: 1) 0-1000 m, 2) 1000-2000 m, 3) 2000-3000 m and 4) deeper than 3000 m. fig. 16 evidences the clear toc % characterizing each depth range. obviously, this great variation is reflected in the high standard deviation shown in fig. 15. the toc plotted for different mediterranean sea areas is shown in fig. 17. in this case, the three regions: adriatic (adriatic sea), levantine (levantine sea) and ionian-libyan (ionian and libyan sea) clearly show different toc behaviors. a clear bipartition is recorded in the adriatic sea, on the contrary, this is less clear in the levantine and absent in the ionian-libyan sea. what we obtained is new when compared to previous works (alberico et al., 2017; emile-geay et al., 2017). in fact, these databases only use records where the “age” is known, rejecting the records missing this variable. instead, our database permit to manage core correlation in different region, at different depth and showing different sedimentation rates, using depth befig. 13 age vs standardized depth. (a) blue dots correspond to eastern mediterranean sea cores different ages obtained for the sapropel interval. (b) the red line shows the average age for these cores. vertical dashed black lines represent sapropel interval (s1) where the beginning of sapropel is 1 and the top is 0 standardized depth. fig. 14 toc trend in the eastern mediterranean sea. (a) blue dots show toc vs age. (b) red line shows toc vs standardized depth. vertical dashed black lines represent sapropel interval (s1) where the beginning of sapropel is 1 and the top is 0 standardized depth. fig. 15 toc trend across the eastern mediterranean sea. the blue line shows the toc value. the blue-shadow indicate the standard deviation of toc. vertical dashed black lines represent sapropel interval (s1) where the beginning of sapropel is 1 and the top is 0 standardized depth. fig. 16 toc trend across the eastern mediterranean sea based on the core depth. the cores are grouped as: 0-1000 m (light blue), 1000-2000 m (blue), 2000-3000m (dark blue) and >3000 m (black). vertical dashed black lines represent sapropel interval (s1) where the beginning of sapropel is 1 and the top is 0 standardized depth. 180 low sea floor (dbsf) and depths in the sapropel interval. furthermore, our methodology does not suffer of unknown variable (age) limiting the correlation of the cores. however, some issues still need to be addressed. in fact, as the aggregate results yield a mean value in the interval studied, then some events like the bottom ventilation or the burn-down interval evidenced by short lived spikes may result smoothed and the original lithological extension of the sapropel as indicated in löwermark et al., (2006) may be less clear. on the other hand, the advantage to obtain a stack aggregating all the data across the mediterranean allows a wider view and permit to appreciate large scale trends. 4. conclusive remarks and future work paleoceanographic studies are always based on selected sites where researchers perform analyses rarely muti-proxies based, more frequently based on selected a one (e.g., micropaleontology or geochemistry). bda potentially allow to reverse the approach exploiting already published data to be considered and combined all together. beyond, based on a collection of data from existing databases (pangaea, noaa, neotoma…) and on data compiled from the literature, the database: provides a wide variety of organized and standardized paleoproxies relative to the past 20.000 years. this organization allows to correlate data, to extract hidden patterns and new knowledge. enables the analysis of the results in different ways, that is, geographic area or basin depth, allowing to visualize the different proxies trends as a whole. provides a great flexibility in the introduction of new proxies as beyond is organized around the “measurement” entity. allows the possibility to bypass the age variable (not always considered when data are published) and the possibility to correlate cores even when the age is not known. this is the most innovative feature proposed in this paper. our work highlights the advantages and difficulties in the use of new technologies (database, data analytics...) to exploit (paleo) environmental data to reconstruct the dynamics behind the past climate and oceanography related changes. with our results, we show the high potential of using data analytics. yet, the new technology tools such as machine learning, data mining, artificial intelligence will increase their importance for future “paleo” studies. however, before this will happen, we strengthen the need for data standardization as it is the main issue when working with a huge data volumes. we therefore encourage the scientific community to take this challenge in order to improve the exchange and usability of this methodology. beyond is open accessible to all researchers to extract data. as a long term objective, it will be implemented in order to add new data in a way that favors the exchange of knowledge as other databases do (e.g., pangaea or noaa). furthermore, an important achievement will be friendly database where advanced analyses do not need informatic skills. in this regard, we have already developed user-friendly graphical interfaces and services to perform the above described operations (also reported in the appendix b, in the form of sql queries). new functionalities of exploratory analysis will be created in the next future. the output of this will be significantly increment in the data volume thanks to the whole contribution of the scientific community contribution. the rich set of integrated data then will be further exploited by the adopting of data mining techniques, which in the future will allow through automatic or semiautomatic methods the extraction of useful information from large amounts of data, and its scientific use. acknowledgements we would like to acknowledge one anonymous reviewer, caterina morigi, gianluca marino and editor andrea sposato for their constructive comments that were helpful to revise and improve our paper. data pres e n t e d i n t h i s s t u d y a r e a v a i l a b l e at beyond.dii.univpm.it/. references abu-zied r.h., rohling e.j., jorissen f.j., fontanier c., casford j.s.l., cooke, s. (2008) benthic foraminiferal response to changes in bottom-water oxygenation and organic carbon flux in the eastern mediterranean during lgm to recent times. mafig. 17 toc trend across the eastern mediterranean sea based on the area from where the cores have been sampled. the cores are grouped in three regions: adriatic sea (red), levantine sea (green), ionian and libyan seas (blue). vertical dashed black lines represent sapropel interval (s1) where the beginning of sapropel is 1 and the top is 0 standardized depth. amezcua-buendía r. et al. 181 beyond, a new tool for sapropel s1 studies in the mediterranean sea rine micropaleontology, 67(1-2), 46-68. doi:10.1016/j.marmicro.2007.08.006 alberico i., giliberti i., insinga d.d., petrosino p., vallefuoco m., lirer f., ferraro l. (2017) marine sediment cores database for the mediterranean basin: a tool for past climatic and environmental studies. open geosciences, 9(1), 221-239. doi:10.1515/geo-2017-0019 azrieli-tal i., matthews a., bar-matthews m., almogilabin a., vance d., archer c., teutsch n. (2014) evidence from molybdenum and iron isotopes and molybdenum-uranium covariation for sulphidic bottom waters during eastern mediterranean sapropel s1 formation. earth and planetary science letters, 393, 231-242. doi:10.1016/j.epsl.2014.02.054 bell g. (2009) foreword. the fourth paradigm: dataintensive scientific discovery, xi-xv. bout-roumazeilles v., combourieu-nebout n., desprat s., siani g., turon j.l., essallami l. (2013) tracking atmospheric and riverine terrigenous supplies variability during the last glacial and the holocene in central mediterranean. climate of the past, 9(3), 1065-1087. doi:10.5194/cp-9-1065-2013. bown p.r. young j.r. (1998) techniques. in: bown, p.r., ed., calcareous nannofossil biostratigraphy (british micropalaeontological society publications series), chapman and kluwer academic, london, 16-28. calvert s.e., price n.b. (1983) geochemistry of namibian shelf sediments. in coastal upwelling its sediment record. springer, 1, 337-375. doi:10.1007/978-1-4615-6651-9_17 calvert s.e., pedersen t.f. (2007) chapter fourteen elemental proxies for palaeoclimatic and palaeoceanographic variability in marine sediments: interpretation and application. developments in marine geology, 1(07), 567-644. doi:10.1016/s1572-5480(07)01019-6 carty s., parrow m.w. (2015). dinoflagellates. freshwater algae of north america, pp. 773-807. doi:10.1016/b978-0-12-385876-4.00017-7 casford j.s. l., rohling e.j., abu-zied r.h., fontanier c., jorissen f.j., leng m.j., thomson j. (2003) a dynamic concept for eastern mediterranean circulation and oxygenation during sapropel formation. in palaeogeography, palaeoclimatology, palaeoecology, 8, 103-119. doi:10.1016/s0031-0182(02)00601-6 cita m.b., vergnaud-grazzini c., robert c., chamley h., ciaranfi n., d’onofrio s. (1977) paleoclimatic record of a long deep sea core from the eastern mediterranean. quaternary research, 8(2), 205235. doi:10.1016/0033-5894(77)90046-1 crudeli d., young j.r., erba e., geisen m., ziveri p., de lange g.j., slomp c.p. (2006) fossil record of holococcoliths and selected heteroholococcolith associations from the mediterranean (holocene-late pleistocene): evaluation of carbonate diagenesis and palaeoecologicalpalaeocenographic implications. palaeogeography, palaeoclimatology, palaeoecology, 237(2-4), 191-212. doi:10.1016/j.palaeo.2005.11.022 de rijk s., hayes a., rohling e.j. (1999) eastern mediterranean sapropel s1 interruption: an expression of the onset of climatic deterioration around 7 ka bp. marine geology, 153(1-4), 337-343. doi:10.1016/s0025-3227(98)00075-9 dozier j., gail w.b. (2009) the emerging science of enviroment applications. the fourth paradigm: data-intensive scientific discovery, 13. dubois-dauphin q., montagna p., siani g., douville e., wienberg c., hebbeln d., colin c. (2017) hydrological variations of the intermediate water masses of the western mediterranean sea during the past 20 ka inferred from neodymium isotopic composition in foraminifera and cold-water corals. climate of the past, 13(1), 17-37. doi:10.5194/cp-13-17-2017 ehrmann w., schmiedl g., hamann y., kuhnt t., hemleben c., siebel w. (2007) clay minerals in late glacial and holocene sediments of the northern and southern aegean sea. palaeogeography, palaeoclimatology, palaeoecology, 249(1-2), 3657. doi:10.1016/j.palaeo.2007.01.004 ehrmann w., schmiedl g., seidel m., krüger s., schulz h. (2016) a distal 140kyr sediment record of nile discharge and east african monsoon variability. climate of the past, 12(3), 713-727. doi:10.5194/cp-12-713-2016 elmasri r., navathe s.b. (2010) fundamentals of database systems (6th ed.). addison-wesley publishing company, usa, pp. 199. emile-geay j., mckay n.p., kaufman d.s., von gunten l., wang j., anchukaitis k.j., zinke j. (2017) a global multiproxy database for temperature reconstructions of the common era. scientific data, 4, 170088. doi:10.1038/sdata.2017.88 fontugne m.r., paterne m., calvert s.e., murat a., guichard f., arnold m. (1989) adriatic deep water formation during the holocene: implication for the reoxygenation of the deep eastern mediterranean sea. paleoceanography, 4(2), 199-206. doi:10.1029/pa004i002p00199 frigola j., moreno a., cacho i., canals m., sierro f.j., flores j.a., grimalt j.o. (2008) evidence of abrupt changes in western mediterranean deep water circulation during the last 50 kyr: a highresolution marine record from the balearic sea. quaternary international, 181(1), 88-104. doi:10.1016/j.quaint.2007.06.016 gallego-torres d., martinez-ruiz f., meyers p.a., paytan a., jimenez-espejo f. j., ortega-huertas m. (2011) productivity patterns and n-fixation associated with pliocene-holocene sapropels: paleoceanographic and paleoecological significance. biogeosciences, 8(2), 415-431. doi:10.5194/bg-8-415-2011 gandomi a., haider m. (2015) beyond the hype: big data concepts, methods, and analytics. international journal of information management, 35(2), 137-144. doi:10.1016/j.ijinfomgt.2014.10.007 grazzini c.v., pierre c. (1991) high fertility in the alboran sea since the last glacial maximum. paleoceanography, 6(4), 519-536. doi:10.1029/91pa00501 gupta a.k., das m., clemens s.c., mukherjee b. (2008) benthic foraminiferal faunal and isotopic changes as recorded in holocene sediments of the northwest indian ocean. paleoceanography, 23(2). doi:10.1029/2007pa001546 hennekam r., jilbert t., schnetger b., de lange g. j. (2014) solar forcing of nile discharge and sapropel s1 formation in the early to middle holocene eastern mediterranean. paleoceanography, 29(5), 343-356. doi:10.1002/2013pa002553 hennekam r., donders t.h., zwiep k., de lange g.j. (2015) integral view of holocene precipitation and vegetation changes in the nile catchment area as inferred from its delta sediments. quaternary science reviews, 130, 189-199. doi:10.1016/j.quascirev.2015.05.031 hilgen f.j. (1991) astronomical calibration of gauss to matuyama sapropels in the mediterranean and implication for the geomagnetic polarity time scale. earth and planetary science letters, 104(2 -4), 226-244. doi:10.1016/0012-821x(91)90206-w ibm marketing cloud (2017) 10 key marketing trends for 2017 and ideas for exceeding customer expectations. https://www-01.ibm.com/common/ssi/cgibin/ ssialias?htmlfid=wrl12345usen incarbona a., ziveri p., sabatino n., manta d.s., sprovieri m. (2011) conflicting coccolithophore and geochemical evidence for productivity levels in the eastern mediterranean sapropel s1. marine micropaleontology, 81(3-4), 131-143. doi:10.1016/j.marmicro.2011.09.003 jimenez-espejo f.j., martinez-ruiz f., sakamoto t., iijima k., gallego-torres d., harada n. (2007) paleoenvironmental changes in the western mediterranean since the last glacial maximum: high resolution multiproxy record from the algerobalearic basin. palaeogeography, palaeoclimatology, palaeoecology, 246(2-4), 292-306. doi:10.1016/j.palaeo.2006.10.005 jimenez-espejo f.j., martinez-ruiz f., rogerson m., gonzález-donoso j.m., romero o.e., linares d., claros j.a.p. (2008) detrital input, productivity fluctuations, and water mass circulation in the westernmost mediterranean sea since the last glacial maximum. geochemistry, geophysics, geosystems, 9(11). doi:10.1029/2008gc002096 kemp a.e.s., pearce r.b., koizumi i., pike j., rance s.j. (1999) the role of mat-forming diatoms in the formation of mediterranean sapropels. nature, 398(6722), 57. doi:10.1038/18001 khider d., zhu f., hu j., emile-geay j. (2018) linkedearth/pyleoclim util: pyleoclim release v0.4.0. doi:10.5281/zenodo.1205662. kidd r.b., cita m.b., ryan w.b.f. (1978) stratigraphy of eastern mediterranean sapropel sequences recovered during dsdp leg 42a and their paleoenvironmental significance. initial reports of the deep sea drilling project, 42a, 421-433. doi:10.2973/dsdp.proc.42-1.113-1.1978 kotthoff u., pross j., müller u.c., peyron o., schmiedl g., schulz h., bordon a. (2008) climate dynamics in the borderlands of the aegean sea during formation of sapropel s1 deduced from a marine pollen record. quaternary science reviews, 27(78), 832-845. doi:10.1016/j.quascirev.2007.12.001 kuhnt t., schmiedl g., ehrmann w., hamann y., hemleben c. (2007) deep-sea ecosystem variability of the aegean sea during the past 22 kyr as revealed by benthic foraminifera. marine micropaleontology, 64(3-4), 141-162. doi:10.1016/j.marmicro.2007.04.003 kuhnt t., schmiedl g., ehrmann w., hamann y., andersen n. (2008) stable isotopic composition of holocene benthic foraminifers from the eastern mediterranean sea: past changes in productivity and deep water oxygenation. palaeogeography, palaeoclimatology, palaeoecology, 268(1-2), 106115. doi:10.1016/j.palaeo.2008.07.010 langgut d., almogi-labin a., bar-matthews m., weinstein-evron m. (2011) vegetation and climate changes in the south eastern mediterranean during the last glacial-interglacial cycle (86 ka): new marine pollen record. quaternary science reviews, 30(27-28), 3960-3972. doi:10.1016/j.quascirev.2011.10.016 lingerfelt,e., fils,d., shepherd,a. (2018) project 418: a funded project of the earthcube science support office. in agu fall meeting abstracts. in31b22. lourens l.j., antonarakou a., hilgen f.j., van hoof a. a.m., vergnaud-grazzini c., zachariasse w.j. (1996) evaluation of the plio-pleistocene astronomical timescale. paleoceanography, 11(4), 391413. doi:10.1029/96pa01125 löwemark l., lin y., chen h.f., yang t.n., beier c., werner f., lee c.y., song s.r., kao s.j. (2006) sapropel burn-down and ichnological response to late quaternary sapropel formation in two ∼ 400 ky records from the eastern mediterranean sea, palaeogeography, palaeoclimatology, palaeoecology, 239(3-4), 406-425. lussier r.n., hendon j.r. (2016) fundamentals of human resource management: functions, applications, skill development, (1st ed.). sage publications, los angeles. mackensen a., rudolph m., kuhn g. (2001) late pleistocene deep-water circulation in the subantarctic 182 amezcua-buendía r. et al. eastern atlantic. global and planetary change, 30(3-4), 197-229. doi:10.1016/s0921-8181(01)00102-3 martinez-ruiz f., kastner m., paytan a., ortegahuertas m., bernasconi s.m. (2000) geochemical evidence for enhanced productivity during s1 sapropel deposition in the eastern mediterranean. paleoceanography, 15(2), 200-209. doi:10.1029/1999pa000419 martinez-ruiz f., kastner m., gallego-torres d., rodrigo-gámiz m., nieto-moreno v., ortegahuertas m. (2015) paleoclimate and paleoceanography over the past 20,000yr in the mediterranean sea basins as indicated by sediment elemental proxies. quaternary science reviews, 107, 25-46. doi:10.1016/j.quascirev.2014.09.018. mcfedries p. (2011) the coming data deluge, ieee spectrum, 48(2), 19-19. doi:10.1109/mspec.2011.5693066 mckay n.p., emile-geay j. (2016) technical note: the linked paleo data framework a common tongue for paleoclimatology. climate of the past, 12(4), 1093-1100. doi:10.5194/cp-12-1093-2016 meier k.j.s., janofske d., willems h. (2002) new calcareous dinoflagellates (calciodinelloideae) from the mediterranean sea. journal of phycology, 38(3), 602-615. doi:10.1046/j.1529-8817.2002.t01-1-01191.x meier k. j.s., zonneveld k.a.f., kasten s., willems h. (2004) different nutrient sources forcing increased productivity during eastern mediterranean s1 sapropel formation as reflected by calcareous dinoflagellate cysts. paleoceanography, 19 (1), 1-12. doi:10.1029/2003pa000895 möbius j., lahajnar n., emeis k.c. (2010) diagenetic control of nitrogen isotope ratios in holocene sapropels and recent sediments from the eastern mediterranean sea. biogeosciences, 7(11), 39013914. doi:10.5194/bg-7-3901-2010. mojtahid m., manceau r., schiebel r., hennekam r., de lange g.j. (2015) thirteen thousand years of southeastern mediterranean climate variability inferred from an integrative planktic foraminiferalbased approach. paleoceanography, 30(4), 402422. doi:10.1002/2014pa002705. myers p.g., haines k., rohling e.j. (1998) modeling the paleocirculation of the mediterranean: the last glacial maximum and the holocene with emphasis on the formation of sapropel s1. paleoceanography, 13(6), 586-606. doi:10.1029/98pa02736. myers p.g., rohling e.j. (2000) modeling a 200-yr interruption of the holocene sapropel s1. quaternary research, 53(1), 98-104. doi:10.1006/qres.1999.2100 negri a., giunta s. (2001) calcareous nannofossil paleoecology in the sapropel s1 of the eastern ionian sea: paleoceanographic implications. palaeogeography, palaeoclimatology, palaeoecology, 169(1-2), 101-112. doi:10.1016/s0031-0182(01)00219-x olausson e. (1961) studies of deep-sea cores. rep. swed. deep sea exped. 1947-1948, 8, 353-391. parker w.c., arnold a.j. (1999) quantitative methods of data analysis in foraminiferal ecology.modern foraminifera, 5, 71-89. doi:10.1007/0-306-48104-9_5 pedersen t.f., calvert s.e. (1990) anoxia vs. productivity: what controls the formation of organiccarbon-rich sediments and sedimentary rocks? american association of petroleum geologists bulletin, 74(4), 454-466. doi:10.1306/0c9b232b-1710-11d7-864500010-2 -c1865d principato m.s., giunta s., corselli c., negri a. (2003) late pleistocene-holocene planktonic assemblages in three box-cores from the mediterranean ridge area (west-southwest of crete): palaeoecological and palaeoceanographic reconstruction of sapropel s1 interval. palaeogeography, palaeoclimatology, palaeoecology, 190, 61-77. doi:10.1016/s0031-0182(02)00599-0. ridge e. (2014) guerrilla analytics: a practical approach to working with data. guerrilla analytics: a practical approach to working with data. morgan kaufmann. doi:10.1016/c2013-0-14458-3 rohling e.j. (1991) shoaling of the eastern mediterranean pycnocline due to reduction of excess evaporation: implications for sapropel formation. paleoceanography, 6(6), 747-753. doi:10.1029/91pa02455 rohling e.j. (1994) review and new aspects concerning the formation of eastern mediterranean sapropels. marine geology, 122(1-2), 1-28. doi:10.1016/0025-3227(94)90202-x rohling e.j., jorissen f.j., de stigter h.c. (1997) 200 year interruption of holocene sapropel formation in the adriatic sea. journal of micropalaeontology, 16(2), 97-108. doi:10.1144/jm.16.2.97 rohling e.j., marino g., grant k.m. (2015) mediterranean climate and oceanography, and the periodic development of anoxic events (sapropels). earthscience reviews, 143, 62-97. doi:10.1016/j.earscirev.2015.01.008 rossignol-strick m. (1983) african monsoons, an immediate climate response to orbital insolation. nature, 304(5921), 46. doi:10.1038/304046a0. rossignol-strick m. (1985) mediterranean quaternary sapropels, an immediate response of the african monsoon to variation of insolation. palaeogeography, palaeoclimatology, palaeoecology, 49(3-4), 237-263. doi:10.1016/0031-0182(85)90056-2 ryan w.b.f. (1972) stratigraphy of late quaternary sediments in the eastern mediterranean. in: stanley, d.j., ed., the mediterranean sea: a 183 beyond, a new tool for sapropel s1 studies in the mediterranean sea natural sedimentation laboratory: 149-169, stroudsburg, pa.: dowden, hutchinson & ross. sachs j.p., repeta d.j. (1999) oligotrophy and nitrogen fixation during eastern mediterranean sapropel events. science, 286(5449), 2485-2488. doi:10.1126/science.286.5449.2485 sarmiento j.l., herbert t., toggweiler j.r. (1988) mediterranean nutrient balance and episodes of anoxia. global biogeochemical cycles, 2(4), 427444. doi:10.1029/gb002i004p00427 sarnthein m., winn k., jung s.j.a., duplessy j.c, labeyrie l., erlenkeuser h., ganssen g. (1994) changes in east atlantic deepwater circulation over the last 30,000 years: eight time slice reconstructions. paleoceanography, 9(2), 209-267. doi:10.1029/93pa03301 schmiedl g., hemleben c., keller j., segl m. (1998) impact of climatic changes on the benthic foraminiferal fauna in the ionian sea during the last 330,000 years. paleoceanography, 13(5), 447458. doi:10.1029/98pa01864 stratford k., williams r.g., myers p.g. (2000) impact of the circulation on sapropel formation in the eastern mediterranean. global biogeochemical cycles, 14(2), 683-695. doi:10.1029/1999gb001157 tachikawa k., vidal l., cornuault m., garcia m., pothin a., sonzogni c., revel m. (2015) eastern mediterranean sea circulation inferred from the conditions of s1 sapropel deposition. climate of the past, 11(6), 855-867. doi:10.5194/cp-11-855-2015 tesi t., asioli a., minisini d., maselli v., dalla valle g., gamberi f., trincardi f. (2017) large-scale response of the eastern mediterranean thermohaline circulation to african monsoon intensification during sapropel s1 formation. quaternary science reviews, 159, 139-154. doi:10.1016/j.quascirev.2017.01.020 thunell r.c., williams d.f., kennett j.p. (1977) late quaternary paleoclimatology, stratigraphy and sapropel history in eastern mediterranean deepsea sediments. marine micropaleontology, 2, 371388. doi:10.1016/0377-8398(77)90018-4 thunell r.c. (1979) pliocene-pleistocene paleotemperature and paleosalinity history of the mediterranean sea: results from dsdp sites 125 and 132. marine micropaleontology, 4, 173-187. doi:10.1016/0377-8398(79)90013-6. triantaphyllou m. v. (2014) coccolithophore assemblages during the holocene climatic optimum in the ne mediterranean (aegean and northern levantine seas, greece): paleoceanographic and paleoclimatic implications. quaternary international, 345, 56-67. doi:10.1016/j.quaint.2014.01.033 triantaphyllou m.v., antonarakou a., dimiza m., anagnostou c. (2010) calcareous nannofossil and planktonic foraminiferal distributional patterns during deposition of sapropels s6, s5 and s1 in the libyan sea (eastern mediterranean). geomarine letters, 30(1), 1-13. doi:10.1007/s00367-009-0145-7 tribovillard n., algeo t.j., lyons t., riboulleau a. (2006) trace metals as paleoredox and paleoproductivity proxies: an update. chemical geology, 232(1-2), 12-32. doi:10.1016/j.chemgeo.2006.02.012 woodruff f., savin s.m. (1985) δ13c values of miocene pacific benthic foraminifera: correlations with sea level and biological productivity. geology, 13 (2): 119-122. doi:10.1130/0091-7613(1985)13<119:cvompb> 2.0.co;2. zahn r., winn k., sarnthein m. (1986) benthic foraminiferal δ13c and accumulation rates of organic carbon: uvigerina peregrina group and cibicidoides wuellerstorfi. paleoceanography, 1(1), 27-42. doi:10.1029/pa001i001p00027. ziegler m., tuenter e., lourens l.j. (2010) the precession phase of the boreal summer monsoon as viewed from the eastern mediterranean (odp site 968). quaternary science reviews, 29(11-12), 1481-1490. doi:10.1016/j.quascirev.2010.03.011 zonneveld k.a.f., versteegh g.j.m., de lange g.j. (2001) palaeoproductivity and post-depositional aerobic organic matter decay reflected by dinoflagellate cyst assemblages of the eastern mediterranean s1 sapropel. marine geology, 172(3-4), 181-195. doi:10.1016/s0025-3227(00)00134-1 184 amezcua-buendía r. et al. ms. received: march 15, 2019 final text received: july 19, 2019 amq_27(2) 11 available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 27 (2), 2014, iii vi report on the courses " fundamentals of soil science" and "the study of paleosols and their use in geology practice” developed by ispra in collaboration with ogl letizia vita, valeria ricci istituto superiore per la protezione e la ricerca ambientale (ispra), rome, italy corresponding author: l. vita <letizia.vita@isprambiente.it> abstract: a short report on two training courses on soil science and paleosols is here presented. they were designed by iitalian institute for environmental protection and research (spra) in collaboration with the order of geologists of latium (ogl). the courses were developed through a blended learning program. a one-day field training in the roman countryside comprised the analysis of two soil profiles specially excavated. keywords: soils, paleosols, training courses, ispra according to one of the most accepted definitions, paleosols are soils that have evolved in environments different from the current one (see ferrari & magaldi, 1983, among others:). the systematic study of these geological layers offers a great potential in paleoclimatic, paleoenvironmental and stratigraphic reconstructions of the quaternary continental record. even the north american stratigraphic code (nacsn, 1983) recognised their undoubted value by introducing specific formal stratigraphic units named pedostratigraphic units or geosols. in addition, the common use of unconformity -bounded stratigraphic units (ubsu, salvador, 1994) for the stratigraphic classification of the quaternary continental and volcanic deposits, also adopted in the geological map of italy at 1: 50,000 scale (cnr, 1992), has often led to use both relict and buried paleosols (fig. 1) as a guide to recognise and track the unconformity surfaces (e.g. coltorti & pieruccini, 2006; giannandrea et al. 2006). as a result, the paleopedological analysis has become a rewarding interpretive tool in the practice of the field geologists and scientists dealing with the study of past environments. however, these studies need a multidisciplinar approach integrating geologicstratigraphic and soil sciences, the latters usually treated in agricultural or agronomic context. this integrated approach is only sporadically available in the training programs of the italian university. therefore the italian institute for environmental protection and research (ispra) has developed two training courses ("fundamentals of soil science" and "the study of paleosols and their use in geology practice ") in collaboration with the order of geologists of latium (ogl) and with the support of aiqua, the italian geological society (sgi), the italian association of physical geography and geomorphology (aigeo) and the italian association of pedologists (aip). the educational activities were held from september 18th to october 31th through a blended learning program including: i) digital self-training courses on the ispra web platform, ii) two days of face-to-face lessons at ispra headquarters in rome and iii) a one-day field training course in the roman countryside (agro romano) which comprised the analysis of two soil profiles specially excavated. the two courses have been designed as an integrated approach, starting from the common basic concepts of pedogenesis and soil classification, then deepening in specific topics relating to soils and paleosols respectively. the general part was organized by ispra geologists m. di leginio and f. fumanti, with the help of the other ispra experts for specific subjects covered by the institute. authors of this note took care of the course on paleosols. visiting professors, some of the leading experts for the subject, have been involved: the lectures on paleosols were given by l. trombino (professor of geopedology at the state university of milan) and f. scarciglia (professor of geopedology at the university of calabria). m. paolanti (self-employed agronomist), and r. napoli [researcher at the council for research and experimentation in agriculture (cra)] provided the lessons on soils. the field activity (fig. 2a) made use of the experience of f. terribile (professor of soil sciences at the university of naples "federico ii"), flanked by r. napoli and m. paolanti. the general part, which was common to both courses, provided participants with an overview of soil properties and functions, classifications and surveying and analysis techniques. applications on soil databases and mapping, including gis techniques, were also outlined. in addition the main factors of land degradation and related monitoring activities were treated, with mentions to soil remediation, restoration and recovery methods. a part of the lessons was devoted to the discussion of the current european, national and regional legislation and to the possible future developments in the italian parliament. the specialized part on present soils are dealt with matters relating to land evaluation and land use planning; notions of hydrology, chemistry and ecology of soils were also provided. as regard to paleosols, basic elements for their definition, recognition, characterization and analysis were illustrated, as well as their use as pedostratigraphic units in geological and paleoenvironmental studies. the significance of the time factor, chronosequences and chronofunctions was widely discussed. several examples of applications of paleopedology to the stratigraphic, paleoenvironmental, paleoclimatic and archaeological reconstruction, in different climatic and geological environments, were presented. the dating methods and their reliability were also mentioned. finally, the micromorphological analysis of soils and the wealth of information that can be drawn were discussed in detail. the field activity took place at casale della perna, near tenuta di decima (rome). at first m. fabbri (vicepresident of the order of geologists of latium) outlined the geological-stratigraphic framework of the area. the practical lesson was then focused on the observation of two soil profiles sited in different geomorphological context: one on the summit plateau and one in the valley area. a geopedological surveying form was given out to participants, then filled in with the help of the experts according to specific guidelines (costantini, 2007). finally participants, on the basis of data detected (fig. 2b), were guided to the classification and interpretation of soils cropping out in the two profiles and to the recognition of an important paleosol, which represent a relevant stratigraphic marker for the roman area. the two courses have received a good acceptance among a number of about 60 researchers and technologists, self-employed, public and private officials, academics, having a cultural background mainly related to earth sciences and in minor part, to environmental, agricultural and biological sciences. references c.n.r. commissione per la cartografia geologica e geomorfologica (1992) carta geologica d'italia alla scala 1:50.000: guida al rilevamento. quaderni del servizio geologico nazionale. ser. 3, n. 1, pp. 203. roma. fig. 1 in the volcanic area of the vulture (italy) the paleosol m18 was used as a marker that divides two supersynthems: it marks the base of the valle dei grigi fosso del corbo synthem, fossilising a transpressive “flower" structure in the underlying barile synthem. (from schiattarella et al., 2005). iv vita l., ricci v. fig. 2 field trip in agro romano (rome, italy): a) fabio terribile and rosario napoli explain how to study a soil profile to course participants; b) participants practice the soil description. a b v ispra soils and paleosols courses coltorti m., pieruccini p. (2006) the last interglacial pedocomplexes in the lithoand morphostratigraphical framework of the central-northern apennines (central italy). quaternary international, 156-157, 118-132. costantini e. a. c. (2007) linee guida dei metodi di rilevamento ed informatizzazione dei dati pedologici. cra-abp, pp. 280. firenze. ferrari g.a., magaldi d. (1983) significato ed applicazioni della padeopedologia nella stratigrafia del quaternario. boll. mus. civ. st. nat. verona, x, 315-340. giannandrea p., la volpe l., principe c., schiattarella m. (2006). unità stratigrafiche a limiti inconformi e storia evolutiva del vulcano medio-pleistocenico di monte vulture (appennino meridionale, italia). boll. soc. geol. it., 125, 67-92. north american commission on stratigraphic nomenclature (nacsn) (1983). north american stratigraphic code: american assoc. petrol. geol. bull., v. 67, p. 841-875. salvador a. (1994) international stratigraphic guide. a guide to stratigraphic classifcation, terminology, and procedure. the international union of geological sciences and the geological society of america (eds.), pp.214. schiattarella m., benaduce p., di leo p., giano s.i., giannandrea p., principe c. (2005) assetto strutturale ed evoluzione morfotettonica quaternaria del vulcano del monte vulture (appennino lucano). boll. soc. geol. it., 124, 543-562. ms. received: november 18, 2014 final text received: december 4, 2014 vi vita l., ricci v. untitled il terremoto aquilano del 6 aprile 2009: rilievo macrosismico, effetti di superficie ed implicazioni sismotettoniche paolo galli1, romano camassi2, raffaele azzaro3, filippo bernardini2, sergio castenetto1, diego molin1, edoardo peronace1, antonio rossi4, maurizio vecchi4 & andrea tertulliani4 1dpc, dipartimento protezione civile nazionale, roma (email: paolo.galli@protezionecivile.it) 2ingv istituto nazionale di geofisica e vulcanolgia, bologna 3ingv istituto nazionale di geofisica e vulcanolgia, catania 4ingv istituto nazionale di geofisica e vulcanolgia, roma al rilievo macrosismico hanno contribuito, in modi e tempi diversi: arcoraci l., berardi m., buffarini g., carlino s., castellano c., cavaliere a., d’amico s., del mese s., ercolani e., gallipoli r., graziani l., leschiutta i., lucantoni a., maramai a., marturano a., massucci a., mucciarelli m., naso g., paolini s., platania r., salimbeni s., tripone d., vannucci g., verrubi v., zuccarello l riassunto: galli p. et al., il terremoto aquilano del 6 aprile 2009: rilievo macrosismico, effetti di superficie ed implicazioni sismotettoniche. (it issn 0394-3356, 2009). viene dato ragguaglio sulle operazioni di rilievo macrosismico relative al terremoto aquilano del 6 aprile 2009 (mw=6.3; io=ix mcs) condotte dal quest e del risultato conseguito in termini di distribuzione delle intensità per 316 località visitate (vedi piano quotato ufficiale allegato). il terremoto, che ha provocato la distruzione di numerosi centri abitati della conca aquilana ed oltre 300 vittime, mostra un’area mesosimica allungata in direzione nw-se, con una coda di forti risentimenti verso se nella conca subèquana. questo è in accordo con la geometria, cinematica e dinamica della rottura della struttura sismogenetica, individuata anche grazie alle evidenze di fagliazione di superficie seguite per circa 20 km lungo il versante nordorientale della valle dell’aterno, tra collebrincioni e san demetrio ne’ vestini (sistema di faglie di paganica-san demetrio). tale struttura viene anche indicata responsabile del terremoto “gemello” del 1461, oltre che di eventi di più elevata energia, come analisi paleosismologiche e rilievi geologici in corso hanno confermato. abstract: galli p. et al., april 6, 2009 l’aquila earthquake: macroseismic survey, surficial effects and seismotectonic implications. (it issn 0394-3356, 2009). in the night of april 6, 2009, a frightful earthquake (mw=6.3) struck the l’aquila region (central apennines, italy), awaking also million of citizens in the 100-km-far city of rome. in the epicentral region the death toll reached 308, most in the town of l’aquila. in only 90 minutes, the first experts of the quick earthquake survey team (quest) started the macroseismic survey, providing data on 40 localities within the first 16 hours, 70 on april 7, 130 on april 9, up to 316 at the end of the in situ survey (july; tabs.1-2. galli & camassi, 2009). the maximum intensity was given to onna and castelnuovo (9-10 mcs, mercalli-cancani-sieberg scale), which were almost totally razed to the ground, while others four villages reached 9 mcs and three 8-9 mcs, amongst which l’aquila (i.e., old town sector intramoenia). most of the damage and collapses affect rubble-stone and/or masonry buildings, especially those which have been overloaded with not-collaborative r.c. roofs (figs.1-3). the r.c. buildings generally experienced few structural damage, and only a dozen were involved in partial collapses (e.g., soft-first story; fig.3a). the mesoseismic area (7-8 mcs) is strongly nw-se elongated, from the hypocentre zone (l’aquila southwestern outskirts) toward the aterno valley (se; fig.4). this fact reflects the geometry, kinematics and rupture dynamics of the seismogenic fault, which has been recognized to be a n135° normal fault (dip at depth 55°), the surficial expression of which fits with the so-called paganica-san demetrio fault system (psdfs in fig.5). in facts, we followed surficial breaks along ~19 km of this structure, from the village of collebrincioni to the nw toward the one of san demetrio ne’ vestini to the se. in some places, we measured a maximum 15 cm offset across the fault, both on bedrock (carbonate and conglomerate) fault scarps, and in unconsolidated talus deposits (fig.6). the macroseismic effects distribution fits quite well with the few intensity datapoints of the 1461 event, that could be thus considered a historical “twin” of the 2009 earthquake. however, preliminary paleoseismological data show a more complex history of the paganica faults, with coseismic offsets consistent with events much stronger than the 1461 and 2009 events. therefore, we hypothesise that the psdfs might generate both earthquakes with magnitude similar to the one of 1461 and 2009 (mw~6.3), but also stronger events, rupturing together with adjacent structures, such as the middle aterno fault system (mafs in fig.5). in this case, the length of the entire fault system (~35 km) would suggest the occurrence of mw~6.9 earthquake, which is the magnitude class of many other apennines events, like the 1915 (fucino) and 1980 (irpinia) ones. parole chiave: l’aquila, macrosismica, media valle dell’aterno, sismotettonica, fagliazione di superficie keywords: l’aquila earthquake, macroseismics, middle aterno valley, seismotectonics, surface faulting. il quaternario italian journal of quaternary sciences 22(2), 2009 235-246 1. introduzione la notte tra domenica e lunedì 6 aprile 2009, alle 3.32 locali, un terremoto di mw=6.3 (ml=5.8) ha devastato il centro storico della città di l’aquila (figg.1-2) e decine di paesi lungo la valle del fiume aterno. l’area mesosismica (i.e., is>vii-viii mcs), allungata per circa 20 km in direzione nw-se, comprende 16 località con i s�viii mcs, delle quali 6 hanno subito effetti di ix grado o superiori, tra cui castelnuovo ed onna (ix-x), che sono risultati i paesi maggiormente danneggiati. il terremoto ha provocato 308 vittime, la maggior parte 236 p. galli et al. delle quali nel centro storico dell’aquila (circa 200), ad onna (41) ed a villa sant’angelo (17). la rottura della fagl ia responsabile del mainshock si è enucleata ad una profondità di circa 9 km (ingv, 2009) su una struttura normale orientata n135°/55° (usgs, 2009 1 ), lungo l’emergenza della quale sono stati riconosciuti numerosi sistemi di fratturazione di superficie (surficial break), assimilabili nel complesso a fagliazione superficiale (faglie collebrincioni-san demetrio in messina et al., 2009; falcucci et al., 2009). il terremoto è stato preceduto da una lunga sequenza sismica (ml<4.0) iniziata nella seconda metà di dicembre nella zona a sudovest di l’aquila (bacino di roio) e culminata con un evento di ml=4.1 il 30 marzo 2009. due scosse avvenute a cavallo della mezzanotte del 5 aprile (ml=3.9 e ml=3.5), fortemente avvertite dal la popolazione aqui lana, hanno indotto molte persone a passare la notte nelle automobili od a spostarsi in luoghi ritenuti più sicuri, così che l’evento devastante delle 3.32 ha causato forse meno vittime di quante la gravità dei danni ne avrebbe provocato. certamente più alto sarebbe stato poi il numero di abitanti coinvolti in crolli se il terremoto fosse avvenuto di giorno, atteso il numero e l’importanza di alcuni edifici pubblici fortemente danneggiati o crollati (p.e., la prefettura di l’aquila – fig.2 e diverse scuole in tutta la provincia). a tutto luglio, al m a i n s h o c k sono seguite quasi 2000 scosse con ml>2, delle quali 195 con ml>3, 20 con ml>4, oltre a due eventi con mw=5.4 e mw=5.6 che hanno provocato un aggravamento, seppur modesto, del quadro del danneggiamento. al momento della stesura di questa nota, la sequenza è ancora in atto, con eventi localizzati sia nell’area mesosismica, che a nw di l’aquila (zona amatrice-montereale, i.e., faglia dei monti della laga: galadini & galli, 2000). nel seguito si dà ragguaglio sulle operazioni di rilievo macrosismico, fornendo il piano quotato “ufficiale” del terremoto (tab.1; ga l l i & ca m a s s i, 2009). si discute, inoltre, sugli effetti di fagliazione superficiale osservati e sulle implicazioni di hazard sismico che questa nuova attesa lezione di geologia del terremoto ha comportato sulle conoscenze sismotettoniche della regione. fig. 1 l’aquila, centro storico (via roma). edifici in muratura mista a pietra semicrollati (foto p.g.) view of the partial collapse of masonry buildings (mixed stones and bricks) in the old town of l’aquila (roma street). fig. 2 l’aquila, edificio della prefettura in crollo semitotale (foto p.g.) view of the prefect’s building, which collapsed in l’aquila old town. 1i valori di strike e dip variano a seconda del metodo usato. da 113° a 147° di strike e da 43° a 60° di dip. gli ipocentri si allungano comunque lungo un piano pendente 55° in profondità. 237il terremoto aquiliano del 6 aprile 2009: rilievo macrosismico ... tab. 1 piano quotato in scala mcs del terremoto del 6 aprile 2009 (solo località direttamente rilevate dagli operatori quest) mcs intensity surveyed by the quest for the april 6, 2009 l’aquila earthquake. 238 2. sismicita’ dell’area l’area dell’alta e media valle dell’aterno è stata colpita con frequenza da terremoti di elevata energia, alcuni dei quali di origine locale. la storia sismica di questa regione rievoca, naturalmente, quella di l’aquila che, dalla sua fondazione avvenuta nel tardo xiii secolo ha subito per ben 6 volte effetti superiori al vii mcs, con punte di ix grado in occasione dei terremoti del 9 settembre 1349, 27 novembre 1461 e 2 febbraio 1703. a parte un forte evento del 1315 (noto solo attraverso poche fonti ed attualmente parametrizzato con mw=5.6 in gr u p p o di la v o r o cpti, 2008; da ora cpti08), il primo terremoto ad arrecare gravissimi danni a l’aquila ed effetti non bene quantificabili in alcuni paesi del reatino e della conca peligna fu appunto quello del 1349 (mw=6.5 in gruppo di lavoro cpti, 2004 – da ora cpti04; ma vedi in cpti08, dove con gli stessi dati di base è stato parametrizzato con mw=5.9). questo terremoto ha avuto in realtà diverse aree epicentrali, la più importante delle quali presso venafro (mw=6.7, ga l l i & na s o, 2009); quella aquilana, molto complessa, con danni tra sulmona, l’aquila e la valle del salto resta di dubbia comprensione, specie per quanto attiene alla sorgente sismogenetica. il successivo evento del 1461 (vedi anche in rossi et al., 2005) colpì duramente gli stessi paesi distrutti dal terremoto del 2009, ed in particolare onna, castelnuovo, poggio picenze e sant’eusanio forconese (x mcs), l’aquila (ix), sino al lontano castelvecchio subéquo2 (viii). similmente al terremoto del 2009, quello del 1461 fu caratterizzato da una lunga sequenza sismica, protrattasi da novembre al marzo successivo, con diversi mainshocks. nuovamente l’area aquilana fu devastata dal terremoto del 2 febbraio 1703 (mw=6.7), probabilmente l’evento storico più gravoso per l’appennino umbroabruzzese insieme alla scossa del 14 gennaio dello stesso anno, localizzata in area nursina (mw=6.7). in quell’occasione a l’aquila l’intensità è stata stimata del ix grado mcs, mentre molti dei paesi più duramente colpiti dal terremoto del 2009 ebbero effetti valutabili con intensità tra l’viii ed il ix mcs (p.e., poggio picenze, san gregorio, sant’eusanio forconese, paganica, bazzano, onna, santa rufina e tempera), ivi compreso castelnuovo che raggiunse il x grado mcs. un ultimo terremoto distruttivo in due località fortemente danneggiate nell’aprile 2009 avvenne il 6 ottobre del 1762 (castelnuovo ix-x mcs e poggio picenze ix), anche se l’elevata intensità in queste due località mal si comprende osservando i bassi valori dei paesi vicini o la scarsezza o assenza di notizie per tutti gli altri limitrofi. infine, un altro evento sismico con origine locale – a parte i due accaduti nel 1786 e nel 1791 (con possibili effetti a l’aquila di vii e vii-viii) – occorse il 24 giugno del 1958 con mw~5 (ro s s i et al.. , 2005). il terremoto ebbe effetti di vii grado in alcuni degli stessi paesi ora gravemente danneggiati (onna e bazzano), oltre che a san demetrio ne’ vestini e la sua area di risentimento, seppur scalata di diversi gradi, ricalca quella dell’evento del 2009. 3. il rilievo macrosismico in occasione di terremoti al di sopra della soglia del danno, un gruppo di “pronto intervento macrosismico” (quest: quick earthquake survey team) composto da operatori afferenti a diverse istituzioni si attiva al fine di realizzare il rilievo speditivo del danneggiamento in termini di scala mcs (si e b e r g, 1930). tale rilievo serve in primo luogo da supporto decisionale alle operazioni di protezione civile e, a posteriori, come strumento per implementare il database macrosismico nazionale. la prima e più urgente finalità viene ottemperata sia nell’immediatezza dell’evento (p.e., tramite l’indirizzo dei primi soccorsi ed il dispiegamento mirato dei mezzi di supporto alla gestione dell’emergenza nelle varie località), sia in seguito, per l’individuazione dei comuni danneggiati da inserire eventualmente nei decreti legge contenenti misure in favore delle popolazioni 3 . proprio in quest’ottica, e cioè al fine di dare una visione oggettiva ed istantanea del danneggiamento al dipartimento della protezione civile nazionale, viene adottata la scala mcs, applicata secondo le specifiche proposte da molin (2003), che prevedono esplicitamente la definizione di percentuali dei diversi livelli di danno presenti. successivamente, il rilievo viene ripetuto – in alcune località anche in termini di scala ems ed esteso regionalmente al fine di poter parametrizzare il terremoto dal punto di vista macrosismico e renderlo confrontabile ai terremoti storici contenuti nei repertori macrosismici nazionali (p.e., dbmi04, st u c c h i et al., 2007). nella notte del 6 aprile, l’attivazione degli operatori quest è avvenuta in maniera “forzata”, non fosse altro perché quelli residenti a roma sono stati svegliati insieme al resto della popolazione della capitale dalle scosse del terremoto. questo ha fatto si che la prima squadra iniziasse il rilievo alle prime luci dell’alba, seguita da una seconda nel pomeriggio e da altre nei giorni successivi, fino ad oltre 5 squadre che hanno agito a rotazione per diversi giorni. in breve, la sera del 6 aprile erano state rilevate 40 località, divenute 70 il giorno dopo, 130 il 9 aprile, 185 il 15 aprile, 281 il 26 maggio e 316 il 1° luglio (tab.1). molte di queste località sono state visitate da squadre diverse e molte sono state riviste in tempi successivi al fine di rendere omogenea la valutazione del grado e di verificare eventuali aggravamenti del danneggiamento. 3.1 tipologie edilizie e condizioni di manutenzione occorre sottolineare che nell’area aquilana (e nello stesso capoluogo) sono presenti tipologie e condizioni edilizie molto diverse. insieme a nuclei di edilizia 2nei repertori sismologici correnti è erroneamente riportato castelvecchio calvisio, ma il toponimo castroveterum attestato nella fonte sincrona è da riferirsi a c. subéquo (p. galli, dati inediti). 3per i terremoti con una vasta ed importante area di danneggiamento p. galli et al. 239 storica in pietra, solitamente non squadrata (spesso ciottoli alluvionali), di pezzatura molto irregolare e con sporadiche presenze di muratura a sacco (rilevanti in alcuni casi in cui gli effetti di danno sono risultati gravissimi, in particolare per l’edilizia monumentale), convivono nuclei di edifici in cemento armato, recenti o meno recenti (fig. 3). all’interno dei centri storici di numerose località, fra gli edifici in pietra sono presenti gruppi di edifici in completo abbandono da decenni e parzialmente diroccati già prima del terremoto. allo stesso tempo convivono nel medesimo insediamento edifici in muratura utilizzati abitualmente e in normali condizioni di manutenzione, edifici in pietra, mattoni o blocchetti di cemento, con solai e coperture in laterocemento, insieme a ville o condomini molto recenti in cemento armato. in qualche caso si osservano edifici in muratura in cui sono visibili interventi relativamente recenti, con la sovrapposizione di una cordolatura e una copertura in cemento armato. come osservato anche in occasione del terremoto del 1997 in umbria marche, questi interventi, senza un contestuale rinforzo delle strutture verticali, hanno solitamente determinato effetti negativi – ed a volte catastrofici – sulle murature (fig.3b). la distribuzione spaziale di queste tipologie edilizie, nei diversi centri, è risultata molto variabile: in qualche caso gli edifici più recenti rappresentano la semplice espansione centrifuga del vecchio centro abitato, in qualche altro caso ne sono una diramazione, in perfetta continuità, in una data direzione, oppure sono dislocati in un’area adiacente, ma significativamente diversa. nel complesso si è osservato che gli edifici in c.a. hanno riportato percentualmente pochi danni strutturali. solo in pochi casi si è verificato il collasso della struttura o di almeno un piano, come per una dozzina di edifici in l’aquila, un edificio di pianola (vedi fig.3a), due tra pettino e cansatessa ed uno a san gregorio. la maggior parte dei danni più gravi e dei crolli sono stati a carico degli edifici in pietra, in muratura e misti, soprattutto per quanto riguarda le parti più elevate dei manufatti (tetti, cornicioni, spigoli ecc…). in molti altri casi si è osservato il crollo totale dei solai all’interno di murature all’apparenza intatte. 3.2 stima degli effetti questa variabilità di situazioni ha reso molto complessa la stima dell’intensità macrosismica, ponendo un serio problema per quanto concerne la comparazione dell’intensità mcs con quella assegnata per i terremoti di epoca medievale e moderna, evidentemente espressione di effetti relativi ad un patrimonio edilizio corrispondente a quello tuttora esistente nei soli centri storici. dal momento che molti di questi ultimi, come accennato, sono urbanisticamente separati dagli agglomerati più recenti, si è ipotizzato di poter assegnare stime di intensità distinte 4 . nel far questo è emerso che per alcune località l’intensità macrosismica assegnata al solo nucleo storico era maggiore anche di 2 gradi mcs di quella assegnata alla località per intero. infatti, laddofig. 3 esempi di danneggiamento subito da diverse tipologie di edifici. a, pianola, edificio in c.a. con schiacciamento totale del primo piano; notare l’estrusione dei pilastri. b, poggio di roio, crollo totale di edificio in pietra al di sotto del tetto spingente in c.a.; c, crollo totale di edificio in pietra (chiesa di san biagio a tempera). l’orologio del piccolo campanile a vela segna l’ora del disastro (foto p.g.). damage affecting different building typologies in villages of the mesoseismic area. a, pianola, crushing of the first storey of a r.c. building (note the out-folded pillars). b, poggio di roio, total collapse of a stone-masonry building under its heavy r.c. roof. c, total collapse of a stone-masonry church (san biagio in tempera; note the clock of the bell-tower, marking the time of the earthquake). 4dato non riportato in tab.1, poiché non sistematicamente raccolto. il terremoto aquiliano del 6 aprile 2009: rilievo macrosismico ... 240 ve l’abitato è rimasto contenuto nel centro storico, il grado mcs non differisce da quello assegnato all’intero abitato (p.e., sant’eusanio forconese, onna, villa sant’angelo, casentino), mentre per altri la differenza oscilla tra 1/2 e 2 gradi. un caso significativo è quello di poggio di roio dove l’intensità nel nucleo storico sarebbe x-xi, mentre nella porzione nuova solo vii. questo problema è stato affrontato con particolare attenzione per l’area urbana di l’aquila, che è stata esplorata con molta attenzione anche per consentirne una valutazione in termini di scala ems. la stima di intensità che si formula per l’aquila è sostanzialmente riferita all’area del centro storico, mentre il danneggiamento delle aree periferiche è sostanzialmente inferiore, di oltre un grado della scala mcs, rispetto all’area del centro storico. 4. distribuzione delle intensità e parametri del terremoto come sempre accade per i terremoti legati all’attivazione di strutture di dimensioni chilometriche (p.e., in appennino centrale: terremoto del fucino del 1915: molin et al., 1999; terremoto di colfiorito, 1997: ga l l i & ga l a d i n i, 1999; me s s i n a et al. , 2002), la distribuzione degli effetti in occasione dell’evento dell’aprile 2009 è stata guidata dalla geometria e orientazione della faglia attivatasi e dal verso di propagazione della rottura. la figura 4 mostra bene questa situazione, con l’area mesosismica (is�v i i viii) concentrata nell’h a ngingwall del sistema di faglie di paganica-san demetrio (psdfs) e con un’importante “coda” di elevate intensità (vii) in direzione se, lungo la media valle dell’aterno, sin verso la conca subéquana. qui in particolare, castelvecchio subéquo e goriano sicoli hanno subito gravi danni (vii mcs), nonostante siano ubicati a circa 40 km dall’epicentro strumentale. in area mesosismica, come accennato, l’intensità massima è stata assegnata a castelnuovo e ad onna (is=ix-x mcs), dove circa la metà degli edifici sono crollati e comunque gran parte sono andati distrutti, con la morte di oltre un decimo della popolazione residente quella notte (circa 350 persone). estese distruzioni e crolli (ix mcs) hanno subito anche altre frazioni ubicate in prossimità dell’emergenza in superficie della faglia, come tempera (8 vittime), san gregorio (8 vittime), san demetrio (3 vittime) e villa sant’angelo (17 vittime), mentre distruzioni e crolli più localizzati (viii mcs) hanno interessato altre località prossime alla faglia, quali paganica (5 vittime), bazzano (1 vittima), casentino e tussillo. nella zona più prossima all’epicentro strumentale, a parte le gravi distruzioni ed i numerosi crolli parziali fig. 04 distribuzione delle intensità macrosismiche rilevate dal quest in occasione del terremoto del 6 aprile 2009 (galli & camassi, 2009). la stella vuota è l’epicentro macrosismico calcolato mediante l’algoritmo boxer (gasperini, 2004). quella piena è l’ipocentro strumentale (rilocalizzazione ingv, 2009). le linee in grigio rappresentano il sistema di faglie di paganica-san demetrio, responsabile del terremoto (faglia normale immergente a sw, caratterizzata per tutta la sua lunghezza da surficial breaks e/o rigetti massimi di 10-15 cm). notare come l’area mesosismica sia quasi interamente sviluppata nell’hangingwall della faglia ed anche il marcato effetto di direttività della rottura, evidenziata dall’estensione verso se delle intensità più elevate, dall’ipocentro nella conca aquilana sino a quella subéquana (castelvecchio subéquo-goriano sicoli). intensity datapoint distribution surveyed by the quest. the empty star is the macroseismic epicentre, while the black one is the instrumental hypocenter. gray lines represent the sw-dipping paganica-san demetrio fault system, which was the structure responsible for the earthquake and where surface faulting effects were observed along its entire length (max. offset 10-15 cm). it is worth noting that the mesoseismic area is almost entirely extended in the hangingwall of the fault, with a se-directivity effect, from the hypocenter zone toward the subèquana valley (castelvecchio subéquo-goriano sicoli). p. galli et al. del centro storico di l’aquila (viii-ix mcs, circa 200 vittime), vi è da segnalare nel bacino di roio la distruzione pressoché totale del centro storico di poggio di roio (di fatto un x-xi mcs) ed i gravissimi danni ad altre tre località limitrofe (colle di roio, santa rufina e roio piano, viii mcs). in questo grave quadro di danneggiamento emergono alcune anomalie di intensità verso il basso che, a parità di tipologia costruttiva e vulnerabilità degli edifici, appaiono spiegabili appieno solo con effetti di deamplificazione del moto del suolo; queste riguardano il paese di monticchio, nel quale a meno di isolate eccezioni nella periferia dell’abitato – sono state osservate solo lesioni lievi in poche decine di edifici (vi mcs) e la frazione di cerro (fossa), ove non vi sono stati praticamente danni (v mcs). e’ da sottolineare come queste località siano prossime (1-2 km) ad onna, il primo, ed a fossa (vii-viii, 4 vittime) il secondo. altre anomalie, questa volta spiccatamente verso l’alto, sono rappresentate dal nucleo storico di poggio picenze (vii i-ix mcs, 5 vitt ime) ed il già citato castelnuovo (ix-x mcs, 5 vittime), entrambi ubicati nel footwall della faglia e circondati da località con is comprese tra il v-vi ed il vi-vii. in particolare castelnuovo appare come il più evidente effetto di amplificazione locale dell’intero terremoto, ubicato come è in cima ad una collinetta di limi bianchi del pleistocene inferiore. anche in questo caso, di fatto, l’acropoli fortificata è stata rasa praticamente al suolo (x-xi mcs) come già accaduto nel 1461. sebbene anche l’area di vi grado appaia allungata in direzione nw-se per oltre 70 km, essa presenta diverse riprese ed “isole” nei quadranti nordorientali (aree del teramano e pescarese), dove numerose località hanno subito un lieve danneggiamento diffuso (aree a nord della catena del gran sasso e ad est di quella dei monti morrone-cappucciata-san vito). nonostante queste ultime siano tutte distribuite nel f o o t w a l l d e l l a faglia, esse sono in genere ubicate sulle successioni silicoclastiche esterne alla catena mesocenozoica carbonatica e quindi potenzialmente affette da fenomeni sia di amplificazione locale (dovuti alla presenza di terreni con scadenti proprietà meccaniche) che di dissesto (di fatto, in molte di queste località le zone maggiormente danneggiate insistono su pendii in frana). per quanto concerne infine la parametrizzazione macrosismica del terremoto, è possibile assegnare all’evento del 6 aprile un’intensità epicentrale (io) pari al ix grado mcs (imax=ix-x; vedi tab. 2). l’epicentro macrosismico calcolato tramite l’algoritmo boxer 3.3 (ga s p e r i n i, 2004) cade poco a sud di san gregorio, circa 10 km a se di quello strumentale, rilocalizzato ad ovest di l’aquila (ingv, 2009). la magnitudo equivalente calcolata con il medesimo algoritmo è mw=6.0, inferiore a quella valutata strumentalmente. questa differenza è facilmente spiegabile dal fatto che boxer è stato compilato utilizzando le intensità “storiche”, quelle assegnate, in altre parole, valutando gli effetti su un patrimonio edilizio decisamente più vulnerabile di quello attuale. utilizzando per il calcolo della mw le intensità stimate per i soli centri storici di ciascuna località rilevata (in genere, tutte maggiori, come summenzionato), il valore ottenuto tramite boxer è mw=6.3, ovvero lo stesso di quello strumentale. 5. quadro sismotettonico dell’area interessata dal terremoto la sismotettonica dell’area aquilana è dominata dai processi estensionali che caratterizzano la deformazione della crosta appenninica ed in particolare quelli relativi alla distensione ne-sw di questo settore di catena. tale estensione (valutata nell’ordine dei 3 mm/yr tramite misurazioni gps; mantenuto et al., 2007) è accomodata da faglie normali ad andamento nw-se ed immersione tirrenica, alle quali va ascritta tutta la maggiore sismicità dell’appennino centrale (ga l a d i n i & galli, 2000). nell’aquilano tali faglie sono ben note e molte di esse sono state investigate in dettaglio anche attraverso analisi paleosismologiche che ne hanno consentito la parametrizzazione in termini sismogenetici (ga l l i e t a l ., 2008 e relativa bibliografia. vedi fig. 5). ad esse sono stati anche associati i forti terremoti storici della regione, alcuni con l’utilizzo dei dati derivanti dalle analisi paleosismologiche, altri dall’associazione della distribuzione delle massime intensità rispetto all’andamento di ogni singola struttura. in particolare, ga l a d i n i & ga l l i (2000) hanno descritto due principali set di faglie attive nell’area di interesse; l’uno, nel settore più esterno della catena, caratterizzato da faglie e sistemi di faglia normali “silenti”, ovvero con evidenze geologiche e geomorfologiche di attività tardo pleistocene superiore-olocene, ma senza che ad esse sia possibile attribuire terremoti da catalogo (sistemi di faglie della laga, di campo imperatore e del monte morrone, rispettivamente lmfs, cifs e mmfs in fig.5). l’altro, nel settore più interno, al quale sono stati associati gli eventi più distruttivi presenti nei repertori sismologici (sistemi di faglie dell’alta valle dell’aterno, di campo feliceovindoli e del fucino, rispettivamente uafs, cfcfsopfs e ffs in fig.5). la figura 5 mostra schematicamente i due set di faglie ed i terremoti con mw�6.3 associati al sistema occidentale. il terremoto del 1703 (2 febbraio, mw=6.7; cpti04) è stato causato dall’attivazione del sistema di faglie dell’alta valle dell’aterno (uafs; faglie del m. marine e del m. pettino), quello del 1349 (m a i n s h o c k settentrionale, mw=6.5; per quello più meridionale vedi galli & naso, 2009) molto dubitativamente dal sistema di faglie intorno a campo felice (opfs-cfcfs, faglie di ovindoli-pezza, campo felice e colle cerasitto) e 241 tab. 2 parametri epicentrali calcolati a partire dal piano quotato di tabella 1 utilizzando l’algoritmo boxer 3.3 (ga s p e r i n i, 2004) per il calcolo delle coordinate epicentrali e della mw. il valore di quest’ultima calcolato utilizzando i dati rilevati nei soli centri storici è identico a quella calcolata strumentalmente. epicentral parameters evaluated through the boxer 3.3 algorithm (ga s p e r i n i, 2004) on the basis of the data contained in tab. 1. it is worth noting that the instrumental value (mw=6.3) is the same of that obtained by considering the intensities estimated ad hoc for the old-town areas. il terremoto aquiliano del 6 aprile 2009: rilievo macrosismico ... quello catastrofico del 1915 (mw=7) dal sistema di faglie del fucino (ffs). per quanto concerne il terremoto del 1461 (mw=6.5 in cpti04), ga l a d i n i & ga l l i (2000) non forniscono indicazioni se non porre in maniera interrogativa la possibilità che esso sia stato generato dalla fagl ia di assergi (i.e., una delle strutture incluse nel sistema di campo imperatore, fig.5), oppure ad una delle faglie minori nella valle dell’aterno (nel caso specifico e col senno di poi, al sistema di faglie di paganica-san demetrio; psdfs in fig. 5). sempre in zona aquilana, la fig. 5 mostra anche il sistema di faglie della media valle dell’aterno, composto da diversi segmenti caratterizzati da spettacolari nastri di faglia scolpiti nelle successioni carbonatiche, nel cui hangingwall ga l a d i n i & ga l l i (2000) hanno riconosciuto depositi di versante del tardo pleistocene superiore trascinati e fagliati, ma al cui insieme non è possibile collegare alcun terremoto storico. 5.1 il sistema di faglie di paganica-san demetrio (psdfs) diversamente – per esempio dalla faglia del monte marzano (responsabile del terremoto irpino del 1980, mw=6.9), citata spesso come faglia di neoformazione, ma ben riconoscibile in fotografia aerea per tutta la sua estensione anche prima del terremoto 5 , le evidenze di questo sistema di faglie sono frammentarie e limitate principalmente al solo segmento di paganica e di san demetrio (rispettivamente c ed e in fig. 5). anche per questo, la sua 242 5p.e., nel volo base nato dei primi anni ’50, almeno tra san gregorio magno e il m.te valva e lungo tutto il versante a nw di caposele fig. 05 schema delle faglie attive primarie dell’appennino aquilano (le faglie sono tutte a cinematica prevalente normale ed immergono a ~sw). lmfs, sistema di faglie dei monti della laga; cifs, sistema di faglie del monte san franco (ad occidente) e di campo imperatore (ad oriente); uafs, sistema di faglie dell’alta valle dell’aterno (i.e., faglie del monte marine e del monte pettino); in grassetto: psdfs, sistema di faglie di paganica-san demetrio (a, segmento collebrincioni-colle praticciolo; b, colle enzano; c, paganica; d, san gregorio; e, san demetrio): l’intero sistema ha mostrato segni di riattivazione superficiale in occasione del terremoto del 6 aprile; mafs, sistema di faglie della media valle dell’aterno; mmfs, sistema di faglie bordiero della piana di sulmona (faglie del monte morrone); cfcfs, sistema di faglie di campo felice-colle cerasitto; opfs, faglie di ovindoli-piano di pezza; ffs, sistema di faglie del bacino del fucino. le grandi frecce divergenti indicano la direzione di estensione da dati gps (mantenuto et al., 2007). la stella nera indica l’ipocentro del terremoto del 2009 (rilocalizzazione ingv, 2009). in evidenza le date dei terremoti distruttivi associati alle relative strutture tettoniche note. il simbolo dello scavatore indica le faglie investigate e parametrizzate tramite analisi paleosismologiche (vedi in ga l l iet al., 2008 gli studi relativi; i siti 5 e 6 sono stati studiati da alcuni degli scriventi a seguito del terremoto ed i risultati sono in corso di elaborazione; il sito 10 è in corso di elaborazione da falcucci et al.). il meccanismo focale è stato mutuato da usgs (2009). primary active faults in the l’aquila apennine (mainly normal faults, sw-dipping). lmfs, laga mts. fault system; cifs, mt. san franco (west) and campo imperatore (east) fault system; uafs, upper aterno fault system (i.e., mt. marine and mt. pettino faults); bold, paganica-san demetrio fault system (a, collebrincioni-colle praticciolo segment; b, colle enzano; c, paganica; d, san gregorio; e, san demetrio): the whole system showed surficial faulting traces during the april 6 earthquake; mafs, middle aterno fault system; mmfs, sulmona basin fault system (mt. morrone faults); cfcfs, campo felice-colle cerasitto fault system; opfs, ovindoli-piano di pezza fault system; ffs, fucino basin fault system. the big arrows show the extension direction evaluated from gps data (mantenuto et al., 2007). the black star is the hypocenter of the 2009 earthquake (re-located by ingv, 2009). years refer to historical earthquakes possibly caused by the related fault systems. the bulldozer indicates the faults investigated by means of paleoseismological analyses (see in galli et al., 2008; sites 5-6 have been studied by galli et al., 2009; site 10 has been recently studied by falcucci et al.). focal mechanism is from usgs (2009). p. galli et al. geometria, estensione ed attività erano fino ad oggi note in maniera parziale e non conclusiva. secondo bagnaia et al. (1992) il settore di paganica è caratterizzato da un’attività non successiva agli ultimi 18ka b.p., mentre secondo bo n c i o et al. (2004) la faglia di paganica s.s. si raccorda a quella del monte pettino (aquilano s.l.). per quanto concerne il segmento di san demetrio (incluso nel mafs in ga l a d i n i & ga l l i, 2000. vedi già in bosi & bertini, 1970), bertini & bosi (1993) ne evidenziano un’attività posteriore al pleistocene medio e, presumibilmente, di controllo all’attuale assetto geomorfologico della valle dell’aterno. tuttavia, in occasione del presente terremoto, sia alcuni degli scriventi 6 che molti altri geologi di diversi enti ed istituzioni hanno seguito e riconosciuto sul campo tracce incontrovertibili di fagliazione di superficie (p.e., em e r g e o wo r k i n g gr o u p, 2009; fa l c u c c i e t al., 2009; lavecchia et al., 2009; messina et al., 2009a) lungo un insieme di segmenti di faglia qui raggruppati e denominati “sistema di faglie di paganica-san demetrio” (psdfs in fig. 5, n135°). le tracce sono costituite da un insieme di fratture beanti (in genere da pochi millimetri a 3-4 cm, ma fino a 10 cm in alcuni casi), generalmente orientate n110°-140° secondo una geometria e n é c h e l o n con s t e p destro, sia alla mesoscala che alla macroscala. tali fratture hanno interessato indistintamente terreni più o meno coesivi e manufatti antropici, ivi comprese strutture in cemento armato, strade, pavimentazioni varie, muri (in pietra, laterizio e cemento; fig.6). la rottura di superficie, oltre a tagliare e danneggiare quanto sopra nominato, ha anche provocato la rottura per trazione nei giunti di importanti tubature di servizio a paganica, tra cui l’acquedotto del gran sasso e la tubatura a media pressione del gas (rete enelgas). in genere, sono stati osservati almeno due set di fratture parallele, una sviluppata in corrispondenza del piano di faglia (o del nastro in roccia, ove presente in affioramento) ed una (o più) nell’hangingwall, a distanze variabili tra i pochi metri e qualche decametro. in alcuni casi, la beanza delle fratture in corrispondenza della faglia è stata accompagnata da rigetto verticale, cresciuto nell’arco dei successivi 50 giorni dal mainshock e quindi stabilizzatosi. il rigetto ha interessato sia terreni sciolti (con un massimo misurato sulla faglia a paganica non superiore a ~15 cm), che le labbra della faglia in b e d r o c k (i.e., nastro in carbonati o conglomerati v s t a l u s) , con un massimo misurato tra tempera e collebrincioni di 9 cm, cumulati nell’arco di circa 100 giorni (su un cosismico misurato l’8 di aprile di 6 cm; faglia di colle enzano). fatto salvo che la concentrazione e massima espressione (sia in termini di beanza che di rigetto) del campo di fratturazione sono state osservate tra gli abitati di collebrincioni e san gregorio (segmenti b-c-d del psdfs in fig. 5; vedi fa l c u c c i et al. , 2009), un s e t d i fratture – più discontinue e di entità minore, ma dalle stesse caratteristiche geometriche e cinematiche è stata riconosciuta dagl i scr iventi a nord di collebrincioni, sia lungo il nastro in carbonati dissecan243 te colle praticciolo che, soprattutto, nei campi arati sottostanti (segmento a in fig. 5). analogamente, importanti e persistenti fratture n130° sono state seguite nei campi nell’h a n g i n g w a l l della faglia di san demetrio (segmento e in fig. 5) ed in corrispondenza del piano di faglia stesso, ove interessano anche strade e manufatti in pietra e cemento armato all’interno dell’abitato di san demetrio ne’ vestini. dal complesso delle nostre osservazioni, ne discende che la fagliazione si è manifestata per circa 19 km in superficie,“mobilizzando diversi segmenti di faglie precedentemente più o meno noti e/o visibi li . riassumendo, nel suo settore nordoccidentale la faglia si è manifestata lungo il segmento di colle enzano (e relative prosecuzioni a nw verso collebrincioni ed a se al di sotto del viadotto vigne dell’autostrada a24); in quello centrale lungo la faglia s.s. di paganica e la sua prosecuzione a se (san gregorio); in quello sudorientale lungo la faglia di san demetrio. la lunghezza della fagliazione di superficie qui documentata è in buon accordo con i modelli di faglia ottenuti dall’inversione dei dati sar e gps (at z o r i e t al., 2009), che prevedono una lunghezza di faglia di ~20 km, con l’estensione della distribuzione degli a f t e rs h o c k s (ingv, 2009), oltre che con i valori ottenibili usando leggi empiriche di regressione lunghezza fagliamagnitudo (p.e., mw=6.3, l=20 km per le faglie italiane; in galli et al., 2008). tale valore è anche in buon accordo con quello proveniente dall’inversione dei dati gps nel modello a dislocazione variabile (ch e l o n i et al. , 2009). tenuto conto della distribuzione degli a f t e rshocks in profondità lungo una sezione ne-sw e della distanza tra l’ipocentro fornito da ingv (2009) e la faglia in superficie, la pendenza media della faglia in profondità è di ~60°, circa la stessa di quella misurata sui piani di faglia in roccia rimobilizzati (65°±5°). per quanto riguarda l’attività tardo quaternaria di questo sistema di faglie, si sottolinea che studi in corso oltre ad evidenziare la forte impronta sull’evoluzione tettono-sedimentaria e morfologica dell’area (si veda anche me s s i n a et al. , 2009a e 2009b e bibliografia ivi contenuta) suggeriscono uno s l i p r a t e minimo a lungo termine di 0.5 mm/yr, distribuito su almeno tre s p l a y paralleli del segmento di paganica (c in fig.5), dislocanti paleosuperfici e depositi databili a ~0.35-0.56 ma (messina et al., 2009b). d’altra parte, una serie di trincee paleosismologiche aperte in urgenza e per motivi legati all’agibilità 7 degli edifici fondati lungo il segmento di paganica – hanno mostrato rigetti cosismici dei depositi del tardo pleistocene superiore e dell’olocene ben più consistenti di quelli verificatisi in occasione del terremoto del 2009 e, probabilmente, del 1461 (6 in fig.5; galli et al., 2009). in particolare, dalle analisi preliminari – confortate da numerose datazioni assolute l’ultimo evento caratterizzato da rigetto pluridecimetrico dei livelli dislocati è avvenuto sicuramente dopo la fine del primo millennio ad e probabilmente in occasione del terremoto del 2 febbraio 1703 (mw=6.7). 6p. galli, g. naso ed e. peronace. 7molti edifici temporaneamente dichiarati “inagibili” sono ubicati al di sopra od in prossimità della faglia. il terremoto aquiliano del 6 aprile 2009: rilievo macrosismico ... 244 fig. 6 diverse espressioni superficiali del sistema di faglie di paganica-san demetrio. a, fagliazione lungo il nastro scolpito nelle successioni carbonatiche bordiere del bacino di colle enzano (segmento b in fig.5). il rigetto, misurato l’8 aprile a 6 cm e cresciuto a 9 nei due mesi successivi, è qui evidenziato dalla presenza di una guaina di caucciù sol idale all’hangingwall. b, fagliazione nei depositi di versante a ridosso della faglia di paganica s.s. (segmento c in fig.5). il rigetto misurato il 9 aprile era di 11 cm, salito a 13 alla fine dello stesso mese. c, effetti di fratturazione cosismica in un edificio posto in corrispondenza del segmento di paganica. d, esempio di surficial break nei terreni sciolti attraversati dalla frattura cosismica (segmento e in fig.5). e, faglia tra le ghiaie del paleoconoide medio-pleistocenico del torrente raiale (a destra) e depositi colluviali di versante di epoca storica (i tre rettangoli sono campioni per i quali sono stati ottenuti datazioni ams tra 2.5ka e 900 ad; galli et al., 2009). log effettuato sulla parete della “trincea” aperta la notte del 6 aprile dal getto d’acqua a pressione (35 atm.) fuoriuscito a causa della rottura a trazione del giunto dell’acquedotto del gran sasso tra paganica e tempera in corrispondenza della zona di faglia (reticolo 0.5 m). different surficial expression of the paganica-san demetrio fault system. a, faulting along the “nastro” carved in carbonate rocks in the colle enzano intermontane basin (segment b in fig. 5). the offset measured on april 8 was 6 cm, increased up to 9 cm during the following two months (the precise measuring has been obtained thanks to the rubber sheath visible in the picture). b, faulting of the slope deposits close to the paganica fault s.s. (segment c in fig. 5). the offset measured on april 9 was 11 cm, increased to 13 cm at the end of the same month. c, surficial breaks affecting a building crossed by the paganica fault strand. d, surficial breaks in loose deposits (segment e in fig. 5). e, fault between the middle pleistocene gravel of the raiale paleofan (right) and colluvial deposits of historical age (the three rectangles are samples ams-dated between 2.5 ka and 900 ad; galli et al., 2009). log performed on part of the trench opened by the gran sasso 35-atm. pipeline (broken in the night of the earthquake); net 0.5 m. p. galli et al. 6. conclusioni ed implicazioni sismotettoniche all’alba del 6 aprile 2009 le prime squadre quest di rilevamento macrosismico sono giunte in area epicentrale ad appena 90 minuti dall’accadimento del sisma, fornendo già in serata stime di intensità per 40 località, divenute oltre 180 nei primi dieci giorni. nel corso delle prime ore i risultati del rilevamento sono stati di primaria importanza ai fini della gestione dell’emergenza (indirizzo di soccorsi e mezzi), divenendo quindi uno strumento imprescindibile per la valutazione e perimetrazione delle aree di danneggiamento sia per fini di protezione civile prima che come strumento legislativo poi. il risultato finale del rilevamento consta di 316 località con is�v mcs, tutte visitate una o più volte dalle squadre (tab.1). l’intensità epicentrale attribuita è del ix grado mcs, con epicentro macrosismico spostato di circa 10 km a se di quello strumentale. le due località più duramente colpite sono risultate quel le di onna e castelnuovo (entrambe ix-x mcs), mentre il numero in assoluto più alto di edifici danneggiati e di vittime si è verificato nel centro storico di l’aquila (viii-ix mcs, oltre 200 vittime). la magnitudo equivalente stimata utilizzando le intensità calcolate per i soli centri storici delle località nell’area mesosismica – generalmente affetti da danni più severi – restituisce un valore simile a quello valutato strumentalmente (mw=6.3). la distribuzione degli effetti è nettamente allungata in direzione nw-se, con un marcato effetto di direttività verso se. questo fatto è congruente con la direzione della struttura sismogenetica responsabile del terremoto, la cui geometria e cinematica – oltre che dai dati strumentali – si è resa palese a seguito del fenomeno di fagliazione di superficie riconosciuto consensualmente da decine di geologi di diverse istituzioni lungo il c.d. sistema di faglie di paganica-san demetrio. in particolare, secondo gli scriventi, la fagliazione ha avuto luogo per circa 19 km, tra i paesi di collebrincioni a nw e san demetrio ne’ vestini a se. considerando l’analogia tra la distribuzione degli effetti di questo terremoto e quelli relativi all’evento di simile magnitudo occorso nel 1461, è possibile ipotizzare per questa struttura sismogenetica un tempo di ritorno di ~0.5ka per eventi di questa classe di energia. tuttavia, sia i risultati preliminari del rilevamento dei depositi e delle forme tardo quaternari dell’area che quelli provenienti da alcune trincee paleosismologiche scavate attraverso il segmento di paganica, permettono di ipotizzare un comportamento complesso di questa struttura, capace di generare terremoti di magnitudo pari a quella degli eventi del 1461 e del 2009, ma anche eventi assai più energetici, caratterizzati da dislocazioni superficiali molto più consistenti di quelle centimetriche osservate in occasione dell’ultimo evento (per esempio quello del 2 febbraio 1703, mw = 6.7). e’ ragionevole pensare che in occasione di eventi con elevata magnitudo il sistema di faglie di paganicasan demetrio si rompa contemporaneamente ad altre strutture contermini separate da barriere; tra queste, i candidati più probabili sembrano essere sia i sistemi di faglie della alta che della media valle dell’aterno, il secondo silente storicamente, ma sicuramente attivo nel corso della parte alta del pleistocene superiore (galadini & galli, 2000). in questa ipotesi, la lunghezza complessiva della struttura che si potrebbe attivare è di circa 30-35 km, cui corrisponde un valore stimabile di mw~6.7-6.9 (ga l l i et al . , 2008), del tutto compatibile con i rigetti istantanei osservati nelle trincee summenzionate e con l’energia messa in gioco in occasione dei più forti eventi dell’appennino centro-meridionale (p.e., l’aquila 1703, fucino 1915 ed irpinia 1980). da tutto quanto esposto appare che il terremoto aquilano del 6 aprile ben si inserisce nel quadro sismotettonico già precedentemente descritto da diversi autori nella regione, con l’attivazione in profondità di una faglia normale appenninica ad alto angolo (60°), corrispondente in superficie a una serie e n e c h e l o n d i faglie più o meno note e in parte già inserite, seppur con criteri di segmentazione differenti, in lavori di h a z a r d sismico (ga l a d i n i & ga l l i, 2000; bo n c i o et al. , 2004). come dimostrano i precedenti studi di geologia del quaternario (vedi bibliografia in me s s i n a et al. , 2009a) e quelli in corso (vedi citazioni precedenti), anche questa faglia, come molte altre dell’appennino centrale, controlla ampiamente l’assetto topografico, morfologico e sedimentario del suo bacino, potendosi considerare alla stregua delle contermini strutture dell’alta valle dell’aterno (faglie del m.te marine-m.te pettino) e della media valle dell’aterno (faglie di riparoccapreturo-acciano) una faglia primaria sismogenetica di questo tratto di catena. bibliografia at z o r i s., hu n s t a d i., ch i n i m., sa l v i s., to l o m e i c . , bi g n a m i c., st r a m o n d o s., tr a s a t t i e., an t o n i o l i a. & bo s c h i e. (2009) finite fault inversion of dinsar coseismic displacement of the 2009 l’aquila earthquake (central italy) geoph. res. lett., doi: 10.1029/2009gl039293. ba g n a i a r., d’ep i f a n i o a. & sy l o s la b i n i s . (1992) aquila and subaequan basins: an example of quaternary evolution in central apennines, italy quaternaria nova, ii, 187-209 (preprint spec. number 1, 1-23 1989). bertini, t. & bosi, c. (1993) la tettonica quaternaria della conca di fossa (l’aquila), i l quaternario 6, 293–314. bo n c i o p., la v e c c h i a g. & pa c e b . (2004) defining a model of 3d seismogenic sources for seismic hazard assessment applications: the case of central apennines (italy) journal of seismology, 8/3, 407-425. bosi c. & bertini t. (1970) geologia della media valle dell’aterno mem. soc. geol. it. 9, 719 777. cheloni d., d’agostino n., d’anastasio e, mantenuto s, giuliani r., calcaterra s., gambino p. & mattone m. (2009) coseismic and initial postseismic slip of the 2009 mw 6.3 l’aquila earthquake geophysical international journal, fast abstracts, in stampa. em e r g e o wo r k i n g gr o u p (2009) rilievi geologici nell’area epicentrale della sequenza sismica dell’aquilano del 6 aprile 2009 – quaderni di geofisica, n 70, http://portale.ingv.it/produziones c i e n t i f i c a / q u a d e r n i d i g e o f i s i c a / q u a d e r n i d i geofisica-2009/2009-06-23.3943171797. 245il terremoto aquiliano del 6 aprile 2009: rilievo macrosismico ... falcucci e., gori s., peronace e., fubelli g., moro m., sa r o l i m., gi a c c i o b., me s s i n a p., na s o g . , sc a r d i a g., sp o s a t o a., vo l t a g g i o m., ga l l i p . , galadini f. & pantosti d. (2009) surface faulting due to the l’aquila earthquake of april 6th 2009 seismological researh letters, 80, 940-950. ga l a d i n i f. & ga l l i p . (2000) active tectonics in the central apennines (italy) input data for seismic hazard assessment nat. haz. 22, 225–270. galli p. & camassi r. (eds.), (2009): rapporto sugli effetti del terremoto aquilano del 6 aprile 2009, rapporto congiunto dpc-ingv, 12 pp. http://port a l e . i n g v . i t / r e a l t i m e m o n i t o r i n g / q u e s t / macrodef_sito.pdf ga l l i p. & ga l a d i n i f . (1999) seismotectonic framework of the 1997-98 umbria-marche (central italy) e a r t h q u a k e s seismological res. letters, 7 0, 4, 404-414. galli p., galadini f. & pantosti d. (2008) twenty years of paleoseismology in italy earth science review, 88, 89-117. galli p. & naso g. (2009) unmasking the 1349 earthquake source (southern italy). paleoseismological and archaeoseismological indications from the aquae iuliae fault j. structural geology, 31, 128149. ga l l i p., gi a c c i o b., me s s i n a p., pe r o n a c e e. (2009) paleoseismological news from l’aquila faults, riassunti del 28° convegno nazionale gngts, trieste 16-19 novembre 2009, 34-37. ga s p e r i n i p . (2004) boxer program programma disponibile in internet al sito: h t t p : / / i b o g f s . d f . u n i b o . i t / u s e r 2 / p a o l o / w w w / b o x e r / b oxer.html gr u p p o d i la v o r o cpti (2004) catalogo parametrico dei terremoti italiani, versione 2004 (cpti04), ingv, bologna. http://emidius.mi.ingv.it/cpti04/ gr u p p o d i la v o r o cpti (2008) catalogo parametrico dei terremoti italiani, versione 2008 (cpti08), ingv, bologna. http://emidius.mi.ingv.it/cpti08/ ingv (2009) la sequenza sismica dell’aquilano, aprile 2009. attività in corso e primi risultati http://port a l e . i n g v . i t / p r i m o p i a n o / a r c h i v i o p r i m o p i a n o / n o t iz i e 2 0 0 9 / t e r r e m o t o 6 a p r i l e / c o p y _ o f _ l a s e q u e nza-sismica-dell-aquilano-aprile-2009/ lavecchia g., boncio p., brozzetti f., de nardis r., di na c c i o d., fe r r a r i n i f., pi z z i a. & po m p o s o g . (2009) the april 2009 aquila (central italy) seismic sequence (mw6.3): a preliminary seismotectonic picture in: p. guarnieri (ed.), recent progress on earthquake geology, nova publisher, in stampa. mantenuto s., bonci l., calcaterra s., d’agostino n., gi u l i a n i r., ma t t o n e m. & me r l i k . (2007) analys is of active extension in the central apennines (abruzzo,italy) using gps measurem e n t s geophysical research abstracts 9 , 04341. egu2007-a-04341 messina p., galadini f., galli p., & sposato a. (2002) quaternary basin evolution and present tectonic regime in the area of the 1997-1998 umbriamarche seismic sequence (central italy) , geomorphology, 42, 97-116. messina p., galli p., falcucci e., galadini f., giaccio b., go r i s., pe r o n a c e e. & sp o s a t o a . (2009a) evoluzione geologica e tettonica quaternaria dell’area interessata dal terremoto aquilano del 2009 geoitalia 2009, 28, pp 24-29, doi: 10.1474/ geoitalia-28-06. messina p., galli p., giaccio b., peronace e. (2009b) evoluzione tettonica tardo quaternaria dell’area interessata dalla faglia di paganica (aq), riassunti del 28° convegno nazionale gngts, trieste 1619 novembre 2009, 47-50. mo l i n d., ga l a d i n i f., ga l l i p., mu c c i l. & ro s s i a . (1999) terremoto del fucino del 13 gennaio 1915 studio macrosismico, in s. castenetto, f. galadini (a cura di): “13 gennaio del 1915. il terremoto nella marsica”. monografia del servizio sismico nazionale, 321-340. molin d. (2003) considerazioni sull’eventuale adozione in italia della scala macrosismica europea (ems1998) – atti del 22° convegno nazionale gngts, isbn/issn:88-900385-9-4, 06.21, 11 pp. ro s s i a., te r t u l l i a n i a. & ve c c h i m . (2005) s t u d i o macrosismico del terremoto dell’aquilano del 24 giugno 1958 il quaternario, 2/18. si e b e r g a (1930) die erdbeben, handbuch der geophysik 4, tab.102, berlin, pp. 527–686. stucchi et alii (2007) dbmi04, il database delle osservazioni macrosismiche dei terremoti italiani utilizzate per la compilazione del catalogo parametrico c p t i 0 4 http://emidius.mi.ingv.it/dbmi04/, quaderni di geofisica, vol 49, pp.38. u s g s (2009) focal mechanism of 01:32 (utc time) 06/04/09 earthquake (italy) internet page: h t t p : / / e a r t h q u a k e . u s g s . g o v / e q c e n t e r / e q i n t h enews/2009/us2009fcaf/#scitech 246 ms. ricevuto il 14 agosto 2009 testo definitivo ricevuto il 14 settembre 2009 ms. received: august 14, 2009 final text received: september 14, 2009 p. galli et al. base the water in the development of florence (central italy) between the roman and the renaissance ages: the resource and the hazard pasquino pallecchi1, marco benvenuti2 & g. carlotta cianferoni1 1soprintendenza ai beni archeologici della toscana, firenze, italy 2dipartimento di scienze della terra, università di firenze, italy corresponding author: m. benvenuti <marcob@geo.unifi.it> abstract: pallecchi p. et al., the water in the development of florence (central italy) between the roman and the renaissance ages: the resource and the hazard. (it issn 0394-3356, 2010) the early geomorphological events occurring in the mid valley of the arno river have determined a suitable setting for the foundation of florence. fluvial processes shaped the future area where bronze age people settled down possibly on a seasonal base, followed by the etruscans and the romans that selected the same location as a suitable place for the early florence town. a network of short tributaries north of the arno river represented transverse physiographic barriers and sources of additional water for a stable settlement. since those times the florentine people experienced the advantages and risks of such a riverine setting. as for other ancient urban centres, the rises and falls of florence have been largely driven by the changing political and socio-economic scenarios. the late middle age and the renaissance re-flourishing of the town, following the late roman age-early middle age depopulation, led to increase in land demand for urban expansion and a growing need of hydropower for the industry. this expansion progressively impacted on the cross-section of the arno river narrowing it and thus increasing the flooding risk. two tributaries, mugnone and s. gervasio creeks, were diverted several times as moats along the city walls as they were rebuilt around the expanding town. a comparison of the frequency of floods in the arno and tiber rives and the global temperature variation for the period spanning the late middle age–renaissance, indicates that anthropic impact on the arno river at florence during the 12th–16th centuries contributed to some catastrophic floods such as the 1333 one that lead to great damage in town and crop failure in the territories. in other periods such as during the cold, humid little ice age between the 16th and 19th centuries, human activities and climatic conditions worked synergistically in determining flooding hazards. riassunto: p. pallecchi et al., l'acqua nello sviluppo di firenze (italia centrale) tra l'epoca romana e il rinascimento: le risorse e i rischi. (it issn 0394-3356, 2010) la città di firenze fu fondata dai romani nel i sec. a.c in una area pianeggiante sulle sponde dell’arno. i processi morfo-genetici e sedimentari tipici del contesto alluvionale intermontano, avevano, durante il quaternario e particolarmente nella sua parte più recente, determinato condizioni favorevoli per un insediamento umano stabile e sempre più strutturato. in epoca romana la città cominciò ad ampliarsi riducendo la sezione idraulica dell’arno, naturalmente già stretta nella zona urbana. questa situazione portò progressivamente l’originaria favorevole ubicazione morfologica ed idraulica della città verso una condizione di crescente rischio alluvionale. dopo il declino urbano e demografico tardo romano-primo medio evo, firenze tornò di nuovo ad espandersi culminando nel rinascimento in un importantissimo centro industriale, commerciale e culturale. il fiume riveste in questo nuovo splendore della città, un ruolo fondamentale; esso infatti rappresentò per il florido artigianato della lana una fonte di energia capace di muovere le macchine che consentivano una produzione su scala industriale. la crescente importanza dell’artigianato della lana spinse i fiorentini ad occupare sempre più il già stretto corso dell’arno urbano aumentando il rischio di piena nella città. il confronto con i dati idro-climatici dell’arno, del tevere e dell’emisfero settentrionale indica che il periodo compreso tra il xii ed il xvi secolo, nonostante sia stato caratterizzato da una bassa frequenza di alluvioni dell’arno e tevere, vide a firenze eventi alluvionali particolarmente catastrofici come quello del 1333. in questo caso sembra che l’impatto umano sul sistema fluviale che attraversava firenze sia stato determinante rispetto al contesto idro-climatico, nel generare un alto rischio idraulico. il successivo periodo compreso tra il xvi ed il xviii secolo, coincidente con la piccola età glaciale caratterizzata nell’emisfero settentrionale da un clima freddo-umido, vede una maggiore frequenza di piene dell’arno e del tevere. in questo caso condizioni idro-climatiche generali ed il contesto urbano di firenze sembrano avere agito sinergicamente sul rischio idraulico per la città. keywords: alluvial geomorphology, urban setting, hydraulic risk, florence, roman age-renaissance. parole chiave: geomorfologia alluvionale, contesto urbano, rischio idraulico, firenze, epoca romana-rinascimento. il quaternario italian journal of quaternary sciences 23(2bis), 2010 volume speciale 323-334 1. introduction since antiquity, urban settlements founded on active alluvial plains have experienced two contrasting conditions. from one side, the geomorphic and depositional dynamics of these physical environments offered optimal conditions for stable settlements due to the availability of water, soil fertility and low-relief surfaces. from the other side, the hydraulic risk connected with the natural behaviour of fluvial systems, primarily controlled by climate variability, may have represented a critical threat for the development of expanding urban centres. moreover, urban planning and construction may have represented feedback agents determining mitigation and/or worsening of flood risk. in other term, as human communities evolved, the anthropic impact is emerged as a significant factor interfering with the natural ones such as climate, tectonics and eustacy, in the development of alluvial plains. in this paper we present the data on the water management at florence, italy, with special reference to the middle age, as a case of human adaptation to, and progressive modifi324 p. pallecchi et al. cation of the arno river plain. these data derive from original geomorphologic and stratigraphic observation, and archaeological and historical records concerning the town evolution from the roman age up to the renaissance. 2. general setting the town of florence is located on the alluvial plain the arno river and its tributaries built in the florence-prato-pistoia (fpp) basin (capecchi et al., 1975; conedera & ercoli, 1973). the basin is a typical, tectonically-controlled, intermontane depression oriented parallel to the axial portion of the northern apennines (fig. 1a). specifically, the fpp basin (fig.1b) is a nw-se trending depression about 38 km long and 12 km wide, bounded by the monte morello–monti della calvana ridge to the ne and by the monte albano–monti del chianti to sw, and crossed by the arno river. the basin shoulders are mostly composed of arenaceous, pelitic, calcareous and, subordinately, magmatic (ophiolites) rocks. these are stacked in a tectonic pile which resulted from the folding and thrusting of oceanic and continental crusts, pertaining respectively to the so-called ligurian and tuscan palaeogeographic domains (vai, 2001). such a crustal deformation started in the early cenozoic during the continental coll ision of the european and african crustal plates. since the late pliocene the axial portion of the resulting orogen, the northern apennines, was affected by differential tectonic movements leading to the formation of several basins whose origin is debated between contrasting extensional and compressive hypotheses (martini et al., 2001; sani et al., 2009). some of the most internal basins were occupied during the quaternary (sensu gibbard et al., 2010) by alluvial and shallow lacustrine environments that are recorded in the various basins by up to 1000 m thick continental clastic successions. in the depocentral zones of the fpp basin, about 500 meters fluvio-lacustrine deposits have been drilled (capecchi et al., 1975). nevertheless, the buried geometry of the fpp basin is presently still poorly known in detail. cores, for example, drilled in the florence plain, at the sw end of the fpp basin, record a maximum thickness of the filling deposit not exceeding two hundred metres (briganti et al., 2003), contrasting with the 500 meters drilled in the central portion of the basin. these differences have been related to a tectonic partition of the basin due to fault systems transversal to basin axis, which determined variable subsidence in the different sectors of the basin (capecchi et al., 1975; briganti et al., 2003). 3. florence plain: morphology and stratigraphy of the shallow subsoil for the purpose of this study we focus on the geomorphic features of the florence plain extracted by digital high-resolution (scale 1:10,000 and 1:2,000) topographic maps (fig. 2). elevation data indicate that this lowland is articulated in distinct surfaces separated by few meters escarpments whose continuity has been interrupted by anthropogenic modifications occurred over about two millennia of land occupation and exploitation. the preserved and inferred morphology of these fig. 1 (a) schematic map of the northern apennines showing the main quaternary intermontane basins. codes for the basins: vm: val di magra; lu: lunigiana; mtc: montecarlo; fpp: florence-prato-pistoia; mu: mugello; va: upper valdarno; ca: casentino: ch: val di chiana; tib: tiberino. (b) simplified map of the fpp basin, palaeo-hydrography (after conedera & ercoli, 1973). (a) carta schematica dell’appennino settentrionale con l’indicazione dei principali bacini intermontani. sigle per i bacini: vm: val di magra; lu: lunigiana; mtc: montecarlo; fpp: firenze-prato-pistoia; mu: mugello; va: valdarno superiore; ca: casentino: ch: val di chiana; tib: tiberino. (b) carta geo-morfologica semplificata del bacino fpp, con paleo-idrografia (da conedera & ercoli, 1973). different surfaces, suggest that the alluvial plain has been built by a progressive down current migration of small alluvial fans primarily fed by the arno river entering the plain from a narrow valley upstream, and by its tributaries mostly located on the hydrographic right, such as the affrico and mugnone creeks. flow expansion determined optimal condition for the development 325the water in the development of florence ... of these fans. in general terms, alluvial fans fed by rivers in aggradational settings such as actively subsiding sedimentary basins given enough sediment supply, are common geomorphic elements of the alluvial plains (distributive fluvial system, hartley et al., 2010). we suggest that in the specific case of the arno river, the downcurrent progradation of successive depositiofig. 2 geomorphological map of the florence plain: black arrows point to possible palaeovalleys outlined by the trend of the 50 metres contour line. points and numbers refer to shallow cores correlated in fig. 3. carta geomorfologica della pianura di firenze: le frecce nere indicano l’ubicazione delle possibili paleovalli evidenziate dal trend delle curve di livello dei 50 m. punti e numeri sono riferiti ai sondaggi superficiali correlati in fig. 3. 326 nal lobes (fig. 2) was accompanied by fan entrenchment. the relief generated by each fan may have perturbed the river profile inducing feeder channel incision which progressively led to the present arno channel. the trend of the 50 meters contour line outlines at the se periphery of florence, north of the modern arno river channel, two not partially filled paleovalleys, relevant for this paper, which are possibly reflecting the ancient confluence of the arno and affrico–s.gervasio courses (fig. 2). another not completely filled paleovalley, that of the mugnone creek, occurs ne of the florence. finally, an area enclosed by the 50 m contour line in the centre of florence, which includes the ancient roman town, is a remnant of an older and relatively higher plain originally connected with the alluvial fan surfaces to the north. utilizing available cores (http://sit.comune.fi.it/sottosuolo/), a stratigraphic fence has been constructed for a portion of the subsoil under the roman downtown up to the eastern boundary of the renaissance town of florence (fig. 3). the fence highlights the following points. (a the pre-alluvial bedrock, made of upper cretaceous limestone and claystone, occurs 15–25 meters below the surfaces. (b) a compound high-relief erosive surface separates the bedrock from the overlying sediment cover, suggesting polycyclic scouring by fluvial processes. (c) the stratigraphically oldest deposit tentatively referred to the middle-late pleistocene, unit 1, consists of muddy sand occurring in cores 591 and 592. (d) sandy gravels occur in every core and are subdivided in two main units, units 2 and 3, possibly separated by an erosive surface attesting to multiple valley incisions. notice that the maximum thickness of the gravels is recorded in cores 447 and 585 where these deposits are ascribed to the younger unit 3; (e) mud occurs on top of the coarse-grained deposits of the two units. its maximum thickness is recorded toward the modern arno river between core 995 and core 447; (f) anthropogenic debris, ranging in thickness from 0 to 7 meters, covers these deposits as the result of continued building up of the florence downtown over about two millennia. surface and subsoil geology indicate that the evolution of this portion of the florence plain occurred possibly during the late quaternary. unit 1 may represent the distal deposition of the alluvial fans fed by the arno river whereas unit 2 represents the channel fill of fig. 3 fence diagram correlating the cores located on fig. 2. the stratigraphic units 1–3 are discussed in the text. pannello di correlazione tra i sondaggi ubicati in fig. 2. le unità stratigrafiche 1–3 sono discusse nel testo. p. pallecchi et al. 327 an arno course located north of the present one. unit 3 testifies to the shifting of the arno in its present position. to notice that the thick gravelly deposits found in the core 585 may represent the fill of a channel crosscutting the older arno course recorded by unit 2, flowing into the unit 3 arno river. the observed trend of the 50 m contour line supports the hypothesis of an ancient confluence between the affrico and arno channels until the latter river shifted southward. the implication for the florence development of all this is that the city was founded on a terrace bounded by the 50 m contour line boundes by channels of the arno river, the abandoned one to the north and the active one to the south. archaeological and historical evidence related to the foundation and development of florence during the roman age (fig. 4a), indicate that such an active channel was that filled by unit 3 gravel and sand. this setting constituted optimal hydraulic and strategic conditions for the early settlement of an area, which took the form of the protoflorence during the roman age. 4. florence development and the water 4.1 the roman period the roman florentia (fig. 4a) was founded in the 1st century bc exploiting the remnant of the relatively higher surface delimited by the 50 m countour line, centred on piazza della repubblica. the square plan of florentia, typical of the roman colonies, is oriented according to the cardinal points (“secondum coelum”) with its southern limit located in the present piazza della signoria and running in a e–w direction, almost parallel to the arno river. to the west the roman town was bounded by the mugnone creek possibly rerouted from an earlier eastern location whose traces have been found in correspondence of the present via del proconsolo thanks to recent archaeological excavations (pallecchi, 2010). such an early, eastern course of the mugnone, also supported by the morphological evidence described in the above section (fig. 2), was adjacent to a poorly drained floodplain today occupied by the s. croce neighbourhood (maetzke, 1941). the roman occupation was accompanied by a wider management of the territory. the reclamation of the surrounding plains for agriculture was done subdividing the land into plots and constructing a network of ditches (centuriazione, castagnoli, 1948). this induced a major transformation to the original alluvial setting. florentia was settled close to the natural narrow channel that favoured the building of the first wood bridge almost in the present location of ponte vecchio (fig. 4a). this channel, shifted from a northernmost location, was then filled with unit 3 gravel and sand. the roman florentine people were well aware of the danger of flooding related to a mismanagement of the water courses. for example, in 15 yr bc florentia asked for and obtained from the roman senate that the drainage channel of the chiana wetland would not be deviated into the arno river, 60 km ne florence, as originally planned by politicians in rome (tacito ann. i, 79). this modification could have increased the arno discharge greatly, augmenting the possibility of flooding. in any case, the flooding risk was increased in florence because of progressive expansion toward the arno river (fig. 4a) and the reclamation of wetlands upstream to construct the amphitheatre and other buildings (maetzke, 1941; de marinis et al., 2006). the reclamation of wetlands impeded upstream expansion of the flood waters increasing risk of flooding of the city. however, the water was not only a potential threat for the roman florence but also a productive opportunity as documented by the remains of laboratories for wool handicraft (fulling mills) found close to the arno river and tributaries (montecchi & pagni, 2005; bigagli et al., 2005; pallecchi, 2006). in late roman time and particularly during its fall in the 5th century when there was a marked increase in precipitation, wetlands expanded again around florentia and the city experienced a drastic reduction in population (bellincioni, 1941; maetzke, 1941; franchovic et al., 2007). 4.2. the middle age and the renaissance at the end of the first millennium ad florence was characterized by renewed growth of the population and of the commercial activities (davidsohn, 1962, franchovic et al., 2007). the need of new land for the expanding urban centre brought a new modification of the drainage system existing around the town (fig. 4b). later on the mugnone creek was shifted west of the expanding perimeter walls and the earlier channel, cut off from the active creek, was enclosed in the town as a ditch known as the fosso dello scheraggio (fig. 4c). the arno river became increasingly important for commercial transport and as a source of hydraulic energy for fulling mills (locally called gualchiere) (fig. 5). several industrial complexes for wool products flourished close to the river, powered by water flows diverted through small feeding canals (gore). similar complexes were also built on low sandy gravelly islands along the river bed. an important such locality was the ognisanti island, near the town centre, where, in the 13th century, the frescobaldi and tornaquinci families built large fulling mills making this island one of the most important centres for wool production (ester, 2005; salvestrini, 2005). the urban reach of the arno river became a strategic location to be occupied as attested to by some castles built by noble florentine families on the river banks, such as the disrupted altafronte castle (fig. 4b) built on the right bank of the river around the modern castellani palace. the residential and industrial pressure on the river (fig. 6) led to further narrowing of its cross section particularly increasing the flooding risk. florence between 1250 and 1300 suffered five severe floods reported with details of casualties and destruction by giovanni villani in his cronica (porta, 1991), and by marchionne stefani in his istoria fiorentina (rodolico, 1903-1955). in the 14th century the town expansion reached its maximum perimeter outlined by the last belt of defensive walls (fig. 4d) (fanelli, 2002). the arno river was confined to its narrowest course, approximately as it is today, by many private and public buildings and industrial plants . a recent archaeological excavation below palazzo bardi located near the right bank of the arno channel (fig. 7a), documents the growing pressure on the water in the development of florence ... 328 fig. 4 plan development of the ancient florence annotated on the topographic map, scale 1:25,000, consequent reduction of the cross section of the arno river and modification of the hydrography. continuous and dotted thin lines indicate active and inactive channel of tributaries, respectively. circled numbers in (a) refer to sites cited in the text; 1: piazza della repubblica; 2: piazza signoria; 3: via del proconsolo: 4: ponte vecchio; 5: s.croce neighbourhood; 6: palazzo castellani; 7: palazzo bardi; 8: ponte alle grazie; 9: corso dei tintori. (a) the roman plan, thick dotted line refers to the early southern boundary of the town, later shifted few hundred meters to the south. the main course of the mugnone creek was located on the eastern boundary of the town. (b) the 11th century plan: the town is expanding to the river. the altafronte castle (star) was built on the right bank of the river. the eastern channel of the mugnone creek was less important than a westernmost channel at the northern boundary of the town. (c) the 12th century plan: the mugnone creek was further deviated delimiting the western side of the town. the former mugnone channel was encased in the town being the fosso dello scheraggio. (d) the 14th century plan: the maximum expansion of the city walls imposed a further deviation of the mugnone to the west. historical chronicles report the occurrence of a small channel, fosso di s.gervasio, bounding the eastern side of the town since the 12th century (pallecchi, 2006). p. pallecchi et al. 329 sviluppo della pianta dell’antica firenze evidenziato in una carta topografica, alla scala1:25,000, con conseguente riduzione della sezione trasversale del fiume arno e con modificazione della idrografia. le linee continue e tratteggiate indicano rispettivamente canali tributari attivi o inattivi. i numeri cerchiati in (a) sono riferiti ai siti citati nel testo; 1: piazza della repubblica; 2: piazza signoria; 3: via del proconsolo: 4: ponte vecchio; 5: quartiere di s.croce; 6: palazzo castellani; 7: palazzo bardi; 8: ponte alle grazie; 9: corso dei tintori. (a) la pianta della città in età romana, le linee tratteggiate in grassetto indicano l’iniziale limite sud della città, più tardi spostato nella stessa direzione di poche centinaia di metri. il corso principale del torrente mugnone era ubicato al confine orientale della città. (b) la pianta della città intorno all’11° secolo: la città si espande verso il fiume. il castello di altafronte (stella) fu costruito sulla riva sinistra del fiume. il canale orientale del torrente mugnone era meno importante rispetto a quello occidentale situato al confine nord della città. (c) la pianta della città intorno al 12° secolo: il torrente mugnone fu ulteriormente deviato delimitando il lato ovest della città. l’antico canale del mugnone fu costretto nella città diventando il fosso dello scheraggio. (d) la pianta della città intorno al 14° secolo: la massima espansione delle mura della città impose un’ulteriore deviazione del mugnone verso ovest. cronache storiche riportano la presenza di un piccolo canale, fosso di s.gervasio, che delimitava il lato orientale della città dal 12°secolo (pallecchi, 2006). the water in the development of florence ... 330 fig. 5 pictorial view of the western side of florence from south (detail of the 15th century carta della catena). in the foreground the arno river with a wide gravelly bar, channel modification (pescaia) and the various human activities. the mugnone creek is delimiting the western defensive wall of the town (cf fig. 4d). raffigurazione grafica del lato ovest di firenze visto da sud (dettaglio della carta della catena) del 15° secolo. in primo piano il fiume arno dove sono visibili una estesa barra ghiaiosa, una modificazione del canale (pescaia) e lo svolgimento di numerose attività umane. il torrente mugnone è delimitato a ovest dalle mura difensive della città (cf fig. 4d). fig. 6 modern view of the arno river upstream of florence. former gualchiere are today converted into residential buildings. these buildings protruded into the channel, significantly narrowing the hydraulic section. visione attuale del fiume arno a monte di firenze. le gualchiere sono state oggi convertite in palazzi residenziali. questi palazzi sporgono sul fiume riducendone in modo significativo la sezione idraulica. p. pallecchi et al. the river. the stratigraphy (fig. 7b), shows that this site, very close to the right arno river bank, before the 14th century was unexploited and characterized by floodflow expansion. since the 14th century it was used for industrial and residential purposes reducing the arno overbank flood area. furthermore, in the middle age the longitudinal profile of the urban reach of the arno river was perturbed by the building of transverse shallow barriers originally made of wood, the so called pescaie (fig. 5), having the main function of diverting water to the gualchiere. as a consequence the boating in the urban arno channel was interrupted forcing the shift of the urban harbour from its original location near the present ponte alle grazie dating back to the roman time (fig. 4a), to a downstream location in correspondence of the mouth of the mugnone creek (maetzke, 1941). since the 11th century (fig. 4b), the mugnone was progressively shifted to the west at the external side of the enlarging city walls. on the whole the modifications of the urban reach of the arno river greatly increased the risk of flooding and historical sources report a detailed record of the floods which affected florence since the 12th century (morozzi, 1762; caporali et al., 2005). between the 1300 and 1400 four severe floods occurred and the event of the 4th november 1333 was particularly destructive for the town bridges with the exception of the rubaconte bridge, the present ponte alle grazie, though severely damaged. also the altafronte castle was destroyed by this flood and never rebuilt. the report of this event by giovanni villani (porta, 1991), tells about a dynamic of flooding, characterized by overflow invading the streets from walled right bank of the river (lungarni) such as corso dei tintori. the same dynamic has also characterized more recent floods such as the event of the 6th november 1966 when the florence downtown was invaded by muddy floodwater funnelled by the streets facing the lungarni (fig. 8). 5. discussion and concluding remarks the geomorphological processes active during the quaternary and particularly in the late holocene determined a suitable setting for the foundation of florence. the dynamic of the arno river entering the florence plain changed from building of multiple alluvial fans to incising the structures and experiencing channel. during this later stage, reasonably referable to the late quaternary, fluvial processes shaped the florentine area. the arno river shifted from a northern location to approximately the present position cutting a channel in the bedrock. a planar surface standing around 50 m a.s.l and located between the abandoned and the new active river channel, provided to the romans with a suitable place to construct the early florence town. a network of short tributaries north of the arno river represented transverse physiographic barriers and sources of additional water for a stable settlement. since then the florentine people experienced the opportunities and the risks of such a riverine setting. the geomorphic location offered an early defensive advantage but the vicinity of the narrowing arno river led to repeating floods. there are few records attesting 331 fig. 7 (a) google earth oblique 3d view of florence from east. the location of palazzo bardi is indicated by the white arrow. (b) archaeological stratigraphy of a section excavated at the foundation of palazzo bardi and oriented transversally to the nearby arno channel: an early middle age (?) walked ground (big short arrows indicate the main walked levels) is buried by sand and mud deposited from overflow of the arno. dotted lines show internal erosional surfaces reflecting multiple events. an industrial site was built in the 14th century over this original river bank possibly used as a landfill site. the metric rod is 2 meters long. (a) veduta obliqua 3d di firenze vista da est attraverso un’immagine di google earth. l’ubicazione di palazzo bardi è indicata dalla freccia bianca. (b) stratigrafia archeologica di una sezione scavata presso le fondazioni di palazzo bardi e orientata trasversalmente al vicino canale del fiume arno: un piano di calpestio alto medioevale (?) (le frecce spesse e corte indicano i principali livelli di calpestio) è coperto da sabbia e fango depositatesi da una piena dell’arno. le linee tratteggiate mostrano più superfici erosionali indicative di eventi multipli. un sito industriale fu costruito nel 14° secolo sopra questo originaria sponda del fiume e probabilmente utilizzata come discarica. la scala metrica è lunga 2 metri. the water in the development of florence ... to catastrophic floods in florence itself during roman times, but the relatively recent geoarchaeological finding of the pisa-s. rossore fluvial harbour, downsteam in pisa (benvenuti et al., 2006), indicates the recurrence of catastrophic floods in the arno drainge basin during the roman age. the subsequent history of the ancient florence has been largely driven by the political and socio-economic factors. depopulation and town decadence affected florence from the 4th to 10th centuries ad. between the 11th and the 14th centuries florence experienced a renewed urban expansion and industrial activity. the demand of land and hydraulic power increased. the urban reach of the arno river became narrower and partially obstructed by lows barriers (the pescaie) leading to increased risk of flooding. new town walls were built around the enlarging town and the two tributaries, the mugnone and s. gervasio creeks, were diverted several times and used as the west and east moats, respectively, of the new walls. for the last 2000 years, the frequency of the arno river floods (fig. 9a; caporali et al., 2005) which may have had negative consequences for the town development, is compared with the flood frequency distribution of the tiber river at rome (camuffo & enzi, 1995; fig. 9b) and with the temperature variation in the northern hemisphere derived by non-tree ring palaeoclimatic proxies (loehle & mc culloch, 2008; fig. 9c). the comparison between available data for the tiber and arno rivers shows comparable flood frequency between the 16th and the 18th centuries. the preceding period between the 12th and the 16th centuries, was marked in both catchments by lower flood frequency though few high-magnitude events, such as the florentine 1333 flood, occurred. available information indicate that significant temperature variations occurred between the 12th–16th centuries, which correspond to a thermal transition between the middle age warm 332 fig. 8 the flood of november 6, 1966: flood-waters trespassed the lungarni walls, on the right of the arno river, invading the adjacent streets which funnelled the muddy water to the inner downtown. l’alluvione del 6 novembre 1966: il flusso delle acque oltrepassò le spallette dei lungarni, poste alla destra del fiume arno, inondando le vie adiacenti che incalanarono acqua e fango all’interno del centro della città. fig. 9 hydro-climatic data compared. (a) the frequency of historical flood events of the arno river recorded at florence. (from caporali et al., 2005). (b) the flood frequency distribution for the tiber river in the last 2000 years. (from camuffo & enzi, 1995). (c) temperature anomaly in the northern hemisphere during the last 2000 years. (from loehle & mc culloch, 2008). mwp: middle age warm period; lia: little ice age. comparazione tra dati idro-climatici. (a) frequenza degli eventi storici di piena del fiume arno registrati a firenze. (da caporali et al., 2005). (b) distribuzione della frequenza degli eventi di piena del fiume tevere negli ultimi 2000 anni. (da camuffo & enzi 1995). (c) anomalia nelle temperature temperature nell’emisfero nord durante gli ultimi 2000 anni. (da loehle & mc culloch, 2008). mwp: periodo caldo medioevale; lia: piccola età glaciale. period (mwp) and the little ice age (lia), and the 16th–18th centuries period falls fully into the lia. these relations suggest that the arno river floods at florence were enhanced during the late middle age and the renaissance both by the anthropic narrowing of the urban river channel and by natural causes. the colder, moister climatic conditions of the little ice age fostered an increased rate and intensity of floods. similar natural conditions were experienced during the same period by several italian, such as the po and the tiber, and european rivers (brazdil et al., 1999). p. pallecchi et al. 6. references bellincioni g. (1941) il mistero della firenze romana atti della società colombaria fiorentina, firenze, 553–557. benvenuti m., mariotti-lippi m., pallecchi p. & sagri m. (2006) late-holocene catastrophic floods in the terminal arno river (pisa, central italy) from the story of a roman riverine harbor the holocene, 16, 863–876. bigagli c., d’aquino v. & palchetti a. (2005) firenze. ex canonica di s. giovanni notiziario della soprintendenza per i beni archeologici della toscana, 1, 98–100 brazdil r., glaser r., pfister c., dobrovolny p., antoine j-m., barriendos m., camuffo d., deutsch m., enzi, s. guidoboni, e. kotyza, o. & rodrigo, f.s. (1999) flood events of selected european rivers in the sixteenth century – climatic change, 43, 239–285. briganti r., ciufegni s., coli m., polimeni s. & pranzini g. (2003) underground florence: plio-quaternary geological evolution in the florence area bollettino della società geologica italiana, 122, 435–445. camuffo d. & enzi s. (1995) the analysis of two bimillenary series: tiber & po river floods. in: climatic variations and forcing mechanism of the last 2000 years springer-verlag, nato – ansi series, 41, 433–452. capecchi f., guazzone g. & pranzini g. (1975) il bacino lacustre di firenze-prato-pistoia. geologia del sottosuolo e ricostruzione evolutiva bollettino della società geologica italiana, 94, 637–660. caporali e., rinaldi m. & casagli n. (2005) the arno river floods giornale di geologia applicata, 1, 177–192. castagnoli f. (1948) la centuriazione di florentia. l’universo, 28, 361–368. conedera c., ercoli a. (1973) elementi geo-morfologici della piana di firenze dedotti dalla foto interpretazione l'universo, 53, 255–262. davidshon r. (1962) storia di firenze, i primordi della civiltà fiorentina, impulsi interni, influssi esterni e cultura politica, vol. iv, parte i sansoni, firenze, (prima ed. 1922). de marinis g., bianchi s. lelli p., pallecchi p. & salvini m. (2006) discussione storico altimetrica. in: rocchi coopmans de yoldi g. (a cura di), s.maria del fiore e l'architettura fiorentina del duecento e trecento. alinea editore, firenze, 77–87. ester d. (2005) struttura architettonica e patrimonio immobiliare cittadino tra xiii e xviii secolo. il contributo di s. maria nuova alla formazione della città. in: ester d, ghidetti e. (a cura di) la bellezza come terapia. arte e assistenza nell’ospedale di santa maria nuova a firenze atti del convegno, 45–100. fanelli g. (2002) firenze laterza editrice, roma, 308 pp. francovich r., cantini f., scampoli e. & bruttini j. (2007) la storia di firenze tra tarda antichità e medioevo. nuovi dati dallo scavo di via de’ castellani annali di storia di firenze, 2, 9–48. gibbard p. head m.j., walker m.j.c. & the subcommission on quaternary stratigraphy (2010) formal ratification of the quaternary system/period and the pleistocene series/epoch with a base at 2.58 ma journal of quaternary science, 25, 96–102. hartley a.j., weissmann g.s., nichols g. j. & warwick g.l (2010) large distributive fluvial systems: characteristics, distribution, and controls on development. journal of sedimentary research, 80, 167-183 loehle c. & mcculloch j. h. (2008) correction to: a 2000-year global temperature reconstruction based on non-tree ring proxies energy and environment, 19, 93–100. martini i.p., sagri m., colella a. (2001) neogenequaternary basins of the inner apennines and calabria arc. in: vai g.b & martini i.p (eds) anatomy of an orogen: northern apennines and adjacent mediterranean basins. kluwer academic publ., dordrecht, 375-400. metzke g. (1941) florentia (firenze) regio vii etruria, italia romana: municipi e colonie, i, 5, roma. montevecchi n. & pagni m. (2005) firenze. palazzo dell'arte dei giudici e notai notiziario della soprintendenza per i beni archeologici della toscana, 1, 96–97. morozzi f. (1762) dello stato antico e moderno dell'arno e delle cause e de' rimedi delle sue inondazioni. ragionamento istorico-matematico stecchi, firenze. pallecchi p. (2006) la città archeologica: aspetti geomorfologici dell’area fiorentina. in: rocchi coopmans de yoldi g. (a cura di), s. maria del fiore. teorie e storie dell’archeologia e del restauro nella città delle fabbriche arnolfiane. alinea editore, firenze, 5–6. pallecchi p. (2010) le motivazioni di un insediamento umano. morfologia e conformazione del territorio fiorentino. in: pagni m. (a cura di), atlante archeologico di firenze. polistampa, firenze, 16–28. porta g. (a cura di, 1991) giovanni villani, nuova cronica. ugo guanda editore, parma, 1641 pp. rodolico n. (a cura di, 1903-1955) cronaca fiorentina di marchionne di coppo stefani, rerurum italicarum scriptores, 30, i, bologna salvestrini f. (2005) libera città sul fiume regale. firenze e l’arno dall’antichità al quattrocento nardini editore, firenze, 155 pp. sani f., bonini m., piccardi l., vannucci g., delle donne d., benvenuti m., moratti g., corti g., montanari d., sedda l., tanini c. (2009) late pliocenequaternary evolution of outermost hinterland basins of the northern apennines (italy), and their relevance to active tectonics. tectonophysics, 476, 336-356. vai g.b. (2001) structure and stratigraphy: an overview. in: vai g.b & martini i.p (eds) anatomy of an orogen: northern apennines and adjacent mediterranean basins. kluwer academic publ., dordrecht, 15–32. 333the water in the development of florence ... ms. ricevuto il 31 luglio 2010 testo definitivo ricevuto il 19 novembre 2010 ms. received: july 31, 2010 final text received: november 19, 2010 07galadini defining the causes of ancient building collapse (structural decaying vs. seismic shaking) in archaeological deposits of central italy f. galadini istituto nazionale di geofisica e vulcanologia, milano, italy, e-mail: galadini@mi.ingv.it. abstract: f. galadini, defining the causes of ancient building collapse (structural decaying vs. seismic shaking) in archaeological deposits of central italy. (it issn 0394-3356, 2009). deposits that result from the collapse of buildings are usual in geoarchaeological records. deposition can result from natural processes or can be induced by human actions. the investigations at archaeological sites (in particular of the roman imperial age) in central italy indicate that the analysis of the sedimentological-stratigraphic characteristics of collapse layers allows hypotheses as to the origin of a deposit. in the case of layers formed by building decay or seismic destruction, the stratigraphic analysis defines substantial differences that are indicative of different origins. indeed, the stratigraphy of collapse deposits due to building decay is made up of fine-to-coarse grained layers, due to the slow accumulation of materials, which are capped by huge fragments of buildings following the final collapse of the structure. for seismic destruction, large fragments of walls or entire pillars and columns, plus the coarse-grained ruins, usually lie over floors and pavements without interposed layers of abandonment. the characterisation of a collapse deposit has implications in archaeoseismological research, i.e. the identification of traces of past earthquakes during archaeological excavations or through the analysis of the archaeological monumental heritage. riassunto: f. galadini, cause del crollo di edifici dell’antichità (decadimento strutturale vs. scuotimento sismico) dall’analisi di depositi archeologici in italia centrale. (it issn 0394-3356, 2009). depositi che testimoniano il crollo di edifici sono piuttosto comuni nelle stratigrafie geoarcheologiche. la deposizione può derivare da processi naturali o essere causata da azioni umane. indagini condotte in alcuni siti dell’italia centrale (in particolare in riferimento a stratigrafie di età romana imperiale) evidenziano che l’analisi sedimentologico-stratigrafica delle unità di crollo permette la formulazione di ipotesi sull’origine delle stesse. crolli dovuti a vetustà e decadenza degli edifici o a scuotimento sismico si caratterizzano stratigraficamente in maniera diversa. nel primo caso, l’unità di crollo è costituita da sedimenti a granulometria fine alla base e più grossolana verso l’alto. i depositi nella parte basale, al di sopra dei piani di calpestio originari, testimoniano dell’abbandono dell’area in cui la struttura si colloca e del conseguente lento disfacimento della stessa. l’aumento della granulometria verso l’alto indica il coinvolgimento in crollo di parti di edifici sempre più consistenti, fino al collasso di enormi frammenti (in genere delle parti più alte delle strutture, spesso soffitti o porzioni sommitali di pilastri, ecc ...). le porzioni a granulometria maggiore definiscono in genere la fine della sedimentazione, probabilmente a testimonianza di crolli che investono gran parte dell’edificio coinvolto. in caso di distruzione dovuta a scuotimento sismico, l’unità di crollo è costituita da grandi frammenti di pareti o interi pilastri e colonne, nonché da resti delle coperture, individuabili direttamente al di sopra dei piani di calpestio, senza interposti strati di abbandono. la caratterizzazione di un deposito di crollo ha evidenti implicazioni nella ricerca archeosismologica, vale a dire ai fini dell’identificazione delle tracce di terremoti del passato, rinvenute nel corso di scavi archeologici o mediante l’analisi di emergenze archeologiche facenti parte del patrimonio monumentale di una regione. keywords: archaeoseismology, geoarchaeology, collapse deposit, building decay, central italy. parole chiave: archeosismologia, geoarcheologia, unità di crollo, decadimento strutturale, italia centrale. il quaternario italian journal of quaternary sciences 22(1), 2009 73-82 1 introduction deposits derived from the collapse of buildings can be present in archaeological stratigraphies. their origins can be due to a number of reasons, which are basically related to natural events and human actions. earthquakes, volcanic eruptions, landslides and floods have been frequently mentioned in the archaeological literature as being among the natural destructive agents, while wars, urban evolution and land-use are the most frequent among the human destructive interventions (fig. 1). understanding the origin of a collapse deposit is important for two reasons. on the one hand, it casts light on the site history, and in case of a natural origin, it contributes to the improvement of our knowledge on the responses of societies to extreme natural occurrences. on the other hand, the study of naturally induced collapse units has fundamental implications for research aimed at providing a defence against natural catastrophes (e.g. see guidoboni and santoro bianchi, 1995; galadini et al., 2006, for collapse units and archaeoseismology). indeed, finding synchronous evidence of natural destruction at several archaeological sites (e.g. synchronous collapse deposits) can allow the definition of the extent of damage associated with a natural catastrophe. in the case of an earthquake, in particular, this is fundamental for the definition of the parameters that depict the associated energy through analyses of the extent of the damage (gasperini and ferrari, 1997; bakun and wentworth 1997 and 1999; sirovich et al., 2001 and 2002). the main diagnostic problem is that collapse units with different origins will appear similar at a superficial 74 f. galadini level. however, in many cases, the sedimentological-stratigraphic features of a deposit can provide diagnostic evidence. this means that the geoarchaeological practice at an archaeological site can cast light on the origins of a collapse layer. this study provides a geoarchaeological analysis of collapse units that originated – among the possible different causes of destruction – from building decay and seismic shaking. the data have been gathered over about 15 years of field activity in central italy, in archaeological excavations that are mainly related to buildings from antiquity (particularly of the roman imperial age; 1st century ad-5th century ad). after a brief introduction on the seismicity of the investigated region and a short section dedicated to the necessary definitions and nomenclature, some cases will be illustrated to define the types of standard stratigraphies that can directly or partially define the origin of a deposit. although these considerations cannot be thought as exhaustive within this complex issue, the author considers it as a short contribution that should be useful for field practices of geoarchaeologists interested in better understanding complicated mixed human-natural archaeological site histories. 2 seismicity of central italy the investigated region is seismically active and has been struck by numerous destructive earthquakes with magnitude up to 7, as indicated in the cpti seismic catalogue (working group cpti, 2004). the historical large magnitude events have originated along the apennine chain (e.g., jun. 5, 1688; jan. 14, 1703; feb. 2, 1703; nov. 3, 1706; jul. 26, 1805; jan. 13, 1915; respectively with magnitude mw 6.7, 6.8, 6.6, 6.6, 6.6 and 7.0, as indicated in working group cpti, 2004). the largest event has been actually a seismic sequence, occurred in 1456. the number of events composing the sequence is presently matter of debate. it is reported on cpti04 (working group cpti, 2004) as being composed by two major events, both occurred on december 5 in the southern apennines and characterised by magnitude 6.9 and 6.7. all these large magnitude events have been caused by seismogenic sources mainly characterised by normal motion, related to the general extension of the inner apennine domain. the damage to towns and villages of the mountainous areas has been generally very high and estimated with intensity mcs up to 11 (e.g. in the case of the 1915 earthquake; see stucchi et al., 2007). the major events were also responsible for damage to rome (this occurred in the case of the 801 ad, 1349, jan. 14 1703, feb. 2 1703 and 1915 earthquakes; stucchi et al., 2007). paleoseismological and archaeoseismological investigations have also indicated that the earthquake which damaged the colosseum in rome, close to 484 or 508 ad, was originated by the same seismogenic source responsible for the 1915 earthquake (i.e. the fucino fault; galadini and galli, 2001; galadini, 2007). other strong earthquakes struck the investigated region during the antiquity. the possible damage distribution related to the 2nd century ad earthquake in the sulmona area has been recently defined by means of archaeoseismological investigations (ceccaroni et al., 2009). damage in the studied region was also caused by numerous moderate magnitude historical earthquakes (m 5.5-6.0) (working group cpti, 2004). 3 definitions to better understand the content for discussion, the introduction of some definitions is necessary. a collapse deposit contains archaeological remains (chaotically dispersed or arranged) for which the deposition and attitude are derived from the destruction of the buildings. such a deposit will contain portions of walls, tiles and bricks, columns and piers, capitals, epigraphs, among other materials. the collapsed materials may represent particular archaeological deposits. indeed, they may be made of remains of human origin (whatefigure 1 the natural events and human actions that can be responsible for the collapse of structures and the formation of collapse deposits. eventi naturali e azioni umane potenzialmente responsabili del crollo di strutture e della formazione delle unità di crollo. ver the size of the remains), without any naturally formed particles within the matrix (carandini, 2000). in some cases, however, the collapse deposits also contain particles of natural origin, the presence of which is fundamental to the diagnostic aspects (especially for landslide destruction, although not discussed here). i also intend that the materials have not experienced further transport after a collapse, i.e. no processes (cultural or natural) have occurred that have changed the post-collapse attitude. from among the different causative events summarised in figure 1, information on the origins of a collapse deposit can be derived from (mainly sedimentological and stratigraphical) features of the deposit itself, as in the cases of destruction illustrated in the next sections. as mentioned in the introduction, the definition of the origins of collapse deposits has significant implications for the detection of the impact of past natural catastrophes. one of the most widespread applications is the reconstruction of ancient earthquake effects. this is the typical goal of archaeoseismology (e.g. galadini et al., 2006, and references therein), i.e. the analysis of the traces of past earthquakes at archaeological sites or on ancient monuments, through multidisciplinary approaches. 4 the investigated sites 4.1 rome, foro della pace (site 1 in fig. 2; fig. 3a) the recent (since 2000) excavations made at the foro della pace, in the area close to the basilica of massentius and the church of santi cosma e damiano, uncovered remains of the southernmost sector of the forum (fogagnolo, 2006). the remains (particularly impressive are the marble floors and parts of huge columns in granite) were covered by a thick succession of debris (fig. 3a). the attitude of the layers suggests that the materials were originated by the progressive weathering of the adjacent upper portions of the basil ica of massentius. from the sedimentological point of view, a coarsening upward of the debris is evident. the lowermost layers are made of sand and coarse sand, while the upper layers are made of gravel. the deposition of the fine materials probably defines the abandonment of the area and the consequent lack of cleaning in this sector of the forum. the coarse-grained layers and their attitude can be more directly related to the progressive destruction of the basilica of 75defining the causes of... massentius, representing the long-term effect of the lack of maintenance. 4.2 larino, amphitheatre (site 2 in fig. 2; fig. 3b) the amphitheatre, described in tria (1744), was built in the 1st-2nd century ad (coarelli and la regina, 1993). it was probably abandoned at the end of the 3rd century ad and re-used for burials during the 6th-7th century ad (di niro, 1991; iasiello, 2008). the preserved remains of the amphitheatre indicate that in a moment of its long history the building experienced some collapse. indeed, the attitude of huge parts of the structure suggests the occurrence of sudden collapse. however, the collapsed parts are not lying directly over the floor. in most cases these portions of walls or of the vaults are overlying layers of debris. as in the previously described case, the most evident sedimentological characteristics of these layers is the coarsening upward of the grain size (fig. 3b). indeed, the lower layers are mainly made of sand while the uppermost are made of gravel. this succession is generally closed by huge blocks as in figure 3b. in the whole, this suggests an abandonment of the area and the consequent lack of cleaning and accumulation of rubbish (lower layers). figure 2 location map of the sites investigated in central italy. sites: 1) rome, foro della pace; 2) larino, amphitheatre; 3) rome, foro della pace; 4) avezzano, villa rustica of macerine; 5) teano, theatre; 6) urbisaglia, structures of the roman town; 7) san benedetto dei marsi, amphitheatre; 8) plestia, domus; 9) castel di ieri, rooms behind the temple; 10) avezzano, structures of vigne nuove. ubicazione dei siti indagati in italia centrale. siti: 1) roma, foro della pace; 2) larino, anfiteatro; 3) roma, foro della pace; 4) avezzano, villa rustica in località macerine; 5) teano, teatro; 6) urbisaglia, strutture della città romana; 7) san benedetto dei marsi, anfiteatro; 8) plestia, domus; 9) castel di ieri, ambienti adiacenti al tempio; 10) avezzano, resti di strutture in località vigne nuove. 76 figure 3 collapse and building decay. a) accumulation of debris at the base of the structures related to the basilica of massentius, in the foro della pace in rome (site 1 in fig. 2); note the dipping of the layers towards the right of the observer and the upward coarsening of the grain size; b) layers of abandonment and collapse at larino (site 2 in fig. 2); note the upward coarsening of the grain size and the huge block of concrete that seals the stratigraphic succession; c) stratigraphic scheme of an archaeological deposit consistent with the collapse of structures due to building abandonment and decay. crollo e decadimento strutturale. a) accumulo di detriti alla base dei resti della basilica di massenzio, nel foro della pace, roma (sito 1 in fig. 2); si noti la pendenza degli strati verso la destra dell’osservatore e l’aumento della granulometria verso l’alto; b) strati di abbandono e crollo a larino (sito 2 in fig. 2); si noti l’aumento della granulometria verso l’alto e l’enorme resto murario in opera cementizia che sigilla la successione stratigrafica; c) schema stratigrafico relativo a un deposito archeologico compatibile con il crollo di strutture dovuto all’abbandono e al progressivo decadimento strutturale. f. galadini 77 the lack of maintenance resulted in the structural decay which evolved in the final collapse. 4.3 rome, foro della pace (site 3 in fig. 2; fig. 4) another part of the foro della pace, north of that described at section 4.1, was excavated in 1998-2000 (la rocca et al., 2001). here, columns were uncovered lying over a thick unit of debris and reworked materials (fig. 4). this unit accumulated over the floor of this important area of the ancient rome. the accumulation evidently indicates the lost of importance of the area and probably its abandonment, during the late antiquity or the high middle ages. 4.4 avezzano, villa rustica at macerine (site 4 in fig. 2; fig. 5a) since 2004, the archeological excavations have uncovered the remains of buildings related to a settlement of the villa rustica type. the traces of a violent fire were evident throughout the entire archaeological site. remains of large fragments of wooden beams, burnt during the fire, were found everywhere. these fragments were included in the thick collapse layers (fig. 5a) lying over the floors of the destroyed buildings, without an interposed layer of abandonment (borghesi et al., 2007). the fact that the destruction occurred when the building was still in use is also corroborated by the numerous remains related to the daily life uncovered within the collapse layer (borghesi et al., 2007). 4.5 teano, theatre (site 5 in fig. 2; fig. 5b) hypotheses about a late-antique coseismic destruction of the theatre (fig. 5a) were produced by gasperetti (1999) and galadini and galli (2004). part of the architectural decoration and statues have been found in the position of collapse. architectural parts of the scaena were ejected towards the cavea (fig. 5b). walls and pillars showed evidence of differential rotation around the vertical axis, along the largest bricks (bipedalis) (galadini and galli, 2004). further reworked material sealed the collapse. 4.6 urbisaglia, porticus (site 6 in fig. 2; fig. 5c) the remains of the ancient town of urbs salvia in the marche region are presently well preserved and visible within the museum area. the evidence of collapse involving huge parts of the structures is diffused throughout the entire site were the remains are visible. the collapsed structure reported in figure 5c is one of the most impressive cases. the image reports the remains of the cryptoporticus of the temple of the salus in urbs salvia (see http://www.archeomarche.it/scai.htm, for further information and photographs). the collapse occurred suddenly, as indicated by the preservation of the geometry of the entire structure after the collapse. it also occurred when the building was still in use, as indicated by the fact that the ruins are lying over the floor without interposed layers of abandonment. this fact, plus the widespread evidence of destruction throughout the entire town, suggests that the collapse is related to a seismic event. no information is available which may define the age of the destruction. 4.7 san benedetto dei marsi, amphitheatre (site 7 in fig. 2; fig. 5d) the excavations made during 2004 have uncovered the remains of the northern sector of this building. the evidence of damage due to seismic shaking consists in the rotation of parts of the piers at the northern entry of the amphitheatre and a corner expulsion in a major room. moreover, the huge rectangular stones bordering the cavea were found within the collapse unit over the floor, without interposed layer of abandonment, and with a “domino” attitude, defining a sudden collapse (fig. 5d). the collapse has been tentatively attributed to the 484-508 ad earthquake by galadini (2007). this event is reported in the available seismic catalogues (e.g. boschi et al., 1995) and paleoseismologically associated to the faults adjacent to san benedetto dei marsi by galadini and galli (1999). 4.8 plestia, domus (site 8 in fig. 2; fig. 5e) during 1998 the remains of a domus, partially excavated during preceding campaigns, were uncovered in the area struck by the 1997 seismic sequence in central italy (with events characterised by m up to 6.0; figure 4 columns collapsed over a layer of abandonment in the area of the foro della pace in rome (site 3 in fig. 2). colonne in giacitura di crollo al di sopra di uno strato di abbandono nell’area del foro della pace, roma (sito 3 in fig. 2). defining the causes of... figure 5 sudden collapse consistent with the occurrence of seismic shaking. a) materials of the roof and the highest parts of a building collapsed over the floor (layer of abandonment is lacking) at avezzano-macerine (site 4 in fig. 2). the arrows indicate the remnants of a burnt wooden beam; b) evidence for launching of capitals and parts of columns towards the cavea of the teano theatre (site 5 in fig. 2); c) synchronous and oriented collapse of pillars of a porticus in the old town of urbisaglia (site 6 in fig. 2); d) sudden collapse of the slabs bounding the cavea of the amphitheatre at marruvium-san benedetto dei marsi (site 7 in fig. 2), with no layer of abandonment interposed between the collapse unit and the floor; e) collapse of the plaster on the mosaic floor at plestia (domus) (site 8 in fig. 2), with no layer of abandonment i n t e r p o s e d between the collapse unit and the floor; f) toppled wall and collapse of a decorative element in the rooms behind the temple at castel di ieri (site 9 in fig. 2); g) stratigraphic scheme of an archaeological deposit consistent with the sudden collapse of structures that did not experience abandonment, due to seismic shaking. crollo improvviso compatibile con gli effetti dello scuotimento sismico. a) resti del tetto e delle parti alte di un edificio crollato sopra al piano di calpestio, nel sito di avezzano-macerine (sito 4 in fig. 2); si noti l’assenza dello strato di abbandono tra unità di crollo e piano pavimentale; le frecce indicano i resti combusti della travatura in legno; b) unità di crollo comprendente capitelli e parti di colonne “lanciate” verso la cavea del teatro di teano (sito 5 in fig. 2); c) crollo improvviso, sincrono e isorientato di pilastri di un portico nella città di urbisaglia (sito 6 in fig. 2); d) crollo improvviso delle lastre del balteo nell’anfiteatro di marruvium-san benedetto dei marsi (sito 7 in fig. 2); l’unità di crollo si trova al di sopra del piano di calpestio, senza che tra le due unità sia interposto uno strato di abbandono; e) crollo di intonaco sul pavimento musivo di una domus a plestia (sito 8 in fig. 2); lo strato di abbandono è assente tra piano pavimentale e unità di crollo; f) ribaltamento della parete di un edificio e collasso sull’asse verticale di un elemento decorativo negli ambienti rinvenuti davanti al tempio di castel di ieri (sito 9 in fig. 2); g) schema stratigrafico relativo a un deposito archeologico compatibile col crollo cosismico di edifici che non avevano subito in precedenza abbandono. 78 f. galadini e.g. amato et al., 1998). the domus was built during the 1st century bc, (see for information the website of the superintendence: http://www.archeopg.arti.beniculturali.it/geco2fe/default.aspx) the beautiful mosaic visible in figure 5e was sealed by a well preserved layer of plaster. this material originally covered walls made of clay or silt (a typical building technique of the antiquity; see also the case of castel di ieri, below). the distribution of a homogeneous layer of plaster over a large portion of the mosaic suggests that the collapse occurred suddenly. the absence of a layer of abandonment between the mosaic and the collapsed material suggests that the destruction affected a building which was still in use at the time of the catastrophe. this renders the hypothesis of a aging-induced destruction less reliable than that of the collapse due to external causes. 4.9 castel di ieri, rooms behind the temple (site 9 in fig. 2; fig. 5f) well preserved and restored remains of a temple’s podium can be observed at this site as a result of excavations made during the 80s. new excavations made in 2006 uncovered three rooms located in front of the temple, representing parts of a sacred edifice built before the main temple. evidence of sudden collapse is, in this case, impressive (fig. 5f). in particular the toppling of a large portion of wall together with the vertical collapse of a decorative element was detected. the remains were lying over the frequented floor (falcucci et al., 2008). the collapse cannot be conclusively constrained from the chronological point of view. ceccaroni et al. (2009) hypothesise that the destructive event may be identified in the 2nd century ad earthquake, reported in the seismic catalogues (e.g. working group cpti, 2004). 4.10 avezzano, villa rustica at vigne nuove (site 10 in fig. 2; fig. 6) the villa rustica at vigne nuove was excavated during 2005. it is part of the ancient system of farms and settlements surrounding the fucino plain and related to the ancient town of alba fucens, 4 km north of avezzano (e.g. borghesi, 2007). the remains of the different buildings composing this settlement were completely modified by interventions during the antiquity which hinder a conclusive interpretation of the available stratigraphy and of the remains in terms of geometry, function and history of the settlement. it seems probable that the site suffered the effects of a destructive event. after this event, the construction of new floors by using the ruins of previous buildings (fig. 6) can be considered among the interventions following the destruction. 79 figure 6 re-organisation of collapsed materials at avezzano-vigne nuove (site 10 in fig. 2). a) the original ruins are stratigraphically located between the lacustrine sandy substratum (grey arrow) and reworked material made of coarse sand particles demonstrating widespread burning (white arrow). the asterisk indicates the new floor/pavement obtained by manipulation of the ruins; b) panoramic view of the post-destruction floor/pavement. riorganizzazione dei materiali di crollo nel sito di avezzano-vigne nuove (sito 10 in fig. 2). a) i resti originari sono stratigraficamente collocati tra il substrato lacustre sabbioso (freccia grigia) e materiali di riporto costituiti da sedimenti a granulometria sabbiosa grossolana, con evidenti tracce di combustione (freccia bianca). l’asterisco indica il nuovo piano di calpestio ottenuto dalla riorganizzazione dei resti del crollo; b) panoramica del piano di calpestio ricostituito dopo la distruzione. defining the causes of... 3 characteristics of the collapse units and their formation the cases described in the previous section help in defining some stratigraphic aspects which may be diagnostic as for the origin of the archaeological deposit. the next sub-sections will be dedicated to find the general sedimentological and geomorphological features which may represent the link between the effects (the type of collapse unit) and the causes (the origin of the collapses). 3.1 collapse and building decay the progressive deterioration of buildings derive from physical and chemical processes, and as rapp and hill (1998) indicated, these can include: chemical dissolution, mechanical actions due to water temperature changes (especially in joints and pores), abrasion due to wind-transported particles, and exfoliation due to rapid thermal changes. humans can also contribute with bad restoration or, in contrast, with spoliation. the cases analysed in the previous section (subsections 4.1 to 4.3) converge to a sort of stratigraphic model that records the main event responsible for the decay, i.e. building or site abandonment, and its consequence (fig. 3c). in the cases investigated, abandonment is testified by small-sized detrital particles and sands with sparse pebbles (i.e. fragments of pottery, tiles, stones from walls) due to the inception of the decay of the structure. sporadic frequentation may occur during the abandonment phase, and this can be testified, for example, by remains of fireplaces recurring within the stratigraphy. the abandoned site may also become a place for the accumulation of reworked materials that are transported from elsewhere, or a massive dumping site. in this case, the deposition of fine materials may be interrupted by the accumulation of grossly stratified coarser debris, which will generally include fragments of tiles, bricks, pottery and stones, but also rubbish resulting from human practices (see also goldberg and macphail, 2006). the main phase of structural decay begins with the deposition of coarser building elements, usually represented by parts of the roof, i.e. fragmented wooden beams and tiles (figs 3a and 3b). stones from the walls or coarser portions of walls made of cemented stones and bricks overlie the layers related to the beginning of the collapse. the stratigraphic succession ends with huge portions of the building which presumably indicate the final collapse (figs. 3b and 4). this collapse may represent the last act of the degradation history, conditioned by gravitational forces. alternatively, it may be caused by external dynamic forces, such as seismic shaking. but in this case there are few chances to discriminate the origin of the collapse from the stratigraphic point of view, since the convergence of forms is total. however, if the coseismic collapse has been ascertained by means of other information, the presence of a layer of abandonment has some important implications in quantifying the characteristics of the earthquake. for example, if the similarly oriented columns of figure 4 collapsed synchronously for a seismic action (as generally admitted, though debated, in the international literature for suddenly collapsed and similarly oriented columns) the presence of a layer of abandonment below them indicates that maintenance of the collapsed structure was lacking during the years preceding the destruction (fig. 4). this means that the structure probably suffered from aging. the entire picture can define a quite high vulnerability of the collapsed structure, where this high vulnerability implies an overestimation of the energy associated with the destructive event. when the cases investigated are considered in connection with the above description, this clarifies the main rule within an archaeological deposit that arises from decay and collapse of a structure: the upward coarsening of the grain size (fig. 3c). this results from the fact that the process of decay is continuous and progressive, and involves ever larger portions of the structure. 3.2 sudden collapse of non-abandoned structures due to seismic shaking among the natural processes that can produce the sudden collapse of buildings still in use (fig. 1), seismic events can rarely be identified by the presence of natural sediments that suggest the occurrence of an earthquake (e.g. sands re-deposited after liquefaction). in contrast, other natural processes can be more easily identified by the association of the collapse units with landslide accumulations, or volcanic or alluvial deposits. generally, the association with natural deposits is the main diagnostic aspect in deciphering the origins of the natural destruction. in the case of seismic destruction, the stratigraphic succession which may be derived from the discussed cases is quite simple (fig. 5g). a layer of abandonment is not detected over a pavement or a floor. the first evidence of the collapse is seen as a chaotic accumulation of materials that have derived from the highest portions of the building, i.e. tiles and fragments of wooden beams. this results from the “opening” of the structure, from the motion of the walls in different directions during shaking and the related lack of support for the roof. in many cases, the wooden fragments are evidently burnt (fig. 5a), with traces of burning also being seen on ti les and stones. widespread burning was, indeed, a quite usual consequence of seismic shaking in antiquity, and it was probably related to the wide “indoor” use of fire. the grain size of the deposit is usually coarse (tiles and beam fragments) with a sparse matrix. particles of natural origin are absent in this type of collapse deposit. the fragments are in contact with each other, and no layering can be seen. in some cases, the presence of lintels or capitals far from their original position suggests the “launching” of the structure and its decorative elements as a result of severe shaking (fig. 5b). the first layer indicating destruction of the highest part of a structure (abundance of tiles and wooden beams) is overlain by huge portions of walls, pillars and columns, which sometimes lie with a preferred orientation, in response to the polarity of the causal seismic event (fig. 5c, d). this description of the collapsed layers can be considered to be reliable when materials still have their primary attitude following the collapse. indeed, the collapsed materials have often experienced subsequent 80 f. galadini manipulation and transport (fig. 6; site 10 in fig. 2). in such cases, the collapse stratigraphy is not preserved and inferences are not possible. sometimes, manipulated ruins have been detected as overlying the original collapse deposit. these layers of materials in secondary attitude represent the effects of the chaotic filling with reworked deposits, or attempts to give an organisation to the collapse deposit in order to produce a new floor/pavement in the destroyed area (fig. 6). these discussed features can also result from other destructive actions. burning within a house that is not triggered by an earthquake can result in destruction of a building. however, evidence of synchronous collapse at different sites over a large area allows the certainty of the co-seismic origin, since a strong earthquake forms synchronous destruction layers (such as those previously described) throughout a region to a greater extent than other natural or human events. this is the so-called “territorial” approach to the detection of archaeoseismic traces (for case histories and methodology see guidoboni et al., 2000; galadini and galli, 2004; ceccaroni et al., 2009). also, human actions related to wars can have destructive effects on buildings, although in such cases, the investigated sites should show evidence of such a struggle. numerous cases of destruction by invaders are reported for the aegean area and the eastern mediterranean (nur and cline, 2000, and references therein); an italian case can be seen in the recently excavated medieval site of san genesio di vico uualari in tuscany, central italy (cantini, 2005). in all of the cases, the destruction levels are rich in remnants that demonstrate the conflagration (for example, abundance of arrow-heads). 4 conclusive remarks the cases described give a partial view of the possible types of collapse deposits, both in terms of stratigraphic features and in terms of possible origins. however, the above descriptions indicate that the sedimentological-stratigraphic characteristics of collapse deposits can represent one of the key indicators for the definition of the origin of the destruction. within the archaeoseismological perspective, which is definitely one of the main reasons for the analysis of collapse deposits, the described cases clearly indicate that the ability to distinguish between structural decay due to abandonment and that due to sudden effects of seismic shaking is, in theory, possible. however, the stratigraphic evidence related to seismic shaking and discussed above should only be considered as “consistent” with the dynamic causal event, rather than conclusively related to it. this is a quite important point if one considers that the occurrence of an earthquake has probably been the most invoked cause of destruction at archaeological sites in the archaeological literature (debated since the pioneering study by karcz and kafri, 1978). the conclusive evidence relating to seismic shaking has to be obtained by supplementary investigations, such as geomorphological analyses to exclude the occurrence of natural events other than earthquakes and the search for synchronous destruction at other sites, and also a geophysical-engineering approach to evaluate the local seismic response (see galadini et al., 2006, on this topic). on the whole, the cases discussed here and the related stratigraphic models confirm that geoarchaeological investigations of collapse deposits represent one of the fundamental ingredients for the solving of archaeoseismological issues. references amato a., azzara r., chiarabba c., cimini g.b., cocco m., di bona m., margheriti l., mazza s., mele f., selvaggi g., basili a., boschi e., courboulex f., deschamps a., gaffet s., bittarelli g., chiaraluce l., piccinini d., ripepe m. 1998 the 1997 umbria–marche, italy, earthquake sequence: a first look at the main shocks and aftershocks. geophysical research letters 25, 2861–2864. bakun w.h., wentworth c.m., 1997 estimating earthquake location and magnitude from seismic intensity data. bull. of the seismol. soc. am., 87, 15021521. bakun w.h., wentworth c.m., 1999 erratum to estimating earthquake location and magnitude from seismic intensity data. bull. of the seismol. soc. am., 89, 557. borghesi h., 2007 la centuriation. in: a. campanelli (ed.), la petite rome des abruzzes, 50 années de recherches belgo-italiennes à alba fucens. catalogue of the exhibition at the musées royaux d’art et d’histoire de bruxelles, sulmona, 89-92. borghesi h., ceccaroni e., d’antuono n., galadini f., villa d., 2007 la vi l la rustica au l ieu-dit macerine. in: a. campanelli (ed.), la petite rome des abruzzes, 50 années de recherches belgoitaliennes à alba fucens. catalogue of the exhibition at the musées royaux d’art et d’histoire de bruxelles, sulmona, 93-97. boschi e., ferrari g., gasperini p., guidoboni e., smriglio g., valensise g., 1995 catalogo dei forti terremoti in italia dal 461 a.c. al 1980. istituto nazionale di geofisica, sga storia geofisica ambiente, bologna, 973 pp. cantini f., 2005 il medioevo in toscana. san genesio di vico uualari. archeologia viva, 113, 66-68 (in italian). carandini a., 2000 storie dalla terra. torino: einaudi editore, 307 pp. (in italian). ceccaroni e., ameri g., gómez capera a.a., galadini f., (2009) the 2nd century ad earthquake in central italy: archaeeoseismological data and seismotectonic implications. natural hazards. coarelli f., la regina a., 1993 abruzzo, molise. roma-bari, 346 pp. di niro a., 1991 larinum. in: s. capini & a. di niro (eds.), samnium, archeologia del molise, roma, 263-267. falcucci e., agostini s., galadini f., 2007 inquadramento geologico della zona di castel di ieri. in: a. campanelli (ed.), il tempio di castel di ieri, sulmona, 23-30. fogagnolo s., 2006 lo scavo del templum pacis: concordanze e novità rispetto alla forma urbis. in: r. meneghini & r. santangeli valenzani (eds.), forma urbis romae, nuovi frammenti di piante 81defining the causes of... marmoree dallo scavo dei fori imperiali. bullettino della commissione archeologica comunale di roma, supplementi, 15, 55-60. galadini f., 2007 les manifestations du tremblement de terre de l’antiquité tardive. in: a. campanelli (ed.), la petite rome des abruzzes, 50 années de recherches belgo-italiennes à alba fucens. catalogue of the exhibition at the musées royaux d’art et d’histoire de bruxelles, sulmona, 75-81. galadini f., galli p., 1999 the holocene paleoearthquakes on the 1915 avezzano earthquake faults (central italy): implications for active tectonics in the central apennines. tectonophysics, 308, 143170. galadini f., galli p., 2001 archaeoseismology in italy: case studies and implications on long-term seismicity. journal of earthquake engineering, 5, 3568. galadini f., galli p., 2004 the 346 a.d. earthquake (central-southern italy): an archaeoseismological approach. annals of geophysics, 47, 885-905. galadini f., hinzen k.-g., stiros, s., 2006 archaeoseismology: methodological issues and procedure. journal of seismology, 10, 395-414. gasperetti g., 1999 il teatro di teano. archeo, 15 (4), 18. gasperini p., ferrari g., 1997 stima dei parametri sintetici: nuove elaborazioni. in: e. boschi, e. guidoboni, g. ferrari, g. valensise & p. gasperini (eds.), catalogo dei forti terremoti in italia dal 461 a.c. al 1990, 2 (pp. 56-64). bologna: ing-sga (in italian). goldberg p., macphail r.i., 2006 practical and theoretical geoarchaeology. malden, oxford, carlton: blackwell publishing, 455 pp. guidoboni e., santoro bianchi s., 1995 collapses and seismic collapses in archaeology: proposal for a thematic atlas. annali di geofisica, 38, 1013-1017. guidoboni e., muggia a., valensise g., 2000 aims and methods in territorial archaeology: possible clues to a strong fourth-century ad earthquake in the straits of messina (southern italy). in w.j. mcguire, d.r. griffith, p.l. hancock & i.s. stewart (eds.), the archaeology of geological catastrophe (pp. 45-70). london: geological society spec. publ. no. 171. iasiello i.m., 2008 samnium. assetti e trasformazioni di una provincia dell’italia tardoantica. bari, 380 pp. karcz i., kafri u., 1978 evaluation of supposed archaeoseismic damage in israel. journal of archaeological science, 5, 237-253. la rocca e., rizzo s., meneghini r., santangeli valenzani r., 2001 fori imperiali. relazione preliminare degli scavi eseguiti in occasione del giubileo del duemila. römische mittelungen, 108, 171-283. nur a., cline e.h., 2000 poseidon’s horses: plate tectonics and earthquake storms in the late bronze age aegean and eastern mediterranean. journal of archaeological science, 27, 43-63. rapp jr. g., hill c.l., 1998 geoarchaeology. new haven, london: yale university press, 274 pp. sirovich l., pettenati f., 2001 test of sourceparameter inversion of the intensities of a 54,000death shock of the seventeeth century in southeast sicily. bull. seismol. soc. am., 91, 792811. sirovich l., pettenati f., cavallini f., bobbio m., 2002 natural-neighbor isoseismals. bull. seismol. soc. am., 92, 1933-1940. stucchi m., camassi r., rovida a., locati m., ercolani e., meletti c., migliavacca p., bernardini f., azzaro r., albini p., castelli v., d’amico s., gasperini c., gulia l., leschiutta i., meroni f., mirto c., moroni a., tuvè t., 2007 dbmi04, il database delle osservazioni macrosismiche dei terremoti italiani utilizzate per la compilazione del catalogo parametrico cpti04. http://emidius.mi.ingv.it/dbmi04/. quaderni di geofisica, 49, 38 pp. tria g.a., 1744 memorie storiche, civili ed ecclesiastiche della città e diocesi di larino. roma. reprint of 1989, isernia, 813 pp. working group cpti, 2004 catalogo parametrico dei terremoti italiani, versione 2004 (cpti04). ingv, bologna, italy. http://emidius.mi.ingv.it/cpti/ (last check of the availability: december 2, 2008). 82 ms. ricevuto il 22 aprile 2008 testo definitivo ricevuto il 13 marzo 2009 ms. received: april 22, 2008 final text received: march 13, 2009 f. galadini << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /none /binding /left /calgrayprofile (dot gain 20%) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /error /compatibilitylevel 1.4 /compressobjects /tags /compresspages true /convertimagestoindexed true /passthroughjpegimages true /createjdffile false /createjobticket false /defaultrenderingintent 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future aiqua conference, florence, 13-14/06/2018), 11 12 mediterranean sea: many models and few new observational data for the coast, only using the computer will be difficult to improve the projections of the future sea level fabrizio antonioli enea, casaccia, roma, italy corresponding author: f. antonioli <fabrizio.antonioli@enea.it> abstract: over the last few years many papers on sea level change was published without provide observational data in the field, only using large data base and computer, this involves frequent errors in the field data interpretation. keywords: sea level change, model, observational data 1. introduction over the last few years, many papers on sea level change, projection for the future, observational data reviews, isostatic models based on ice melting, have been published, but statistically the reviews or modelling papers are much more frequent than new observational data papers. on the contrary, the mediterranean coasts still reserve many discoveries (geoswim project, furlani et al., 2017a, b) and, less and less are the young researchers that observe in the field, study, date, using geomorphological, archaeological, biological markers strictly related with sea level. 2. data pedoja et al. (2011; 2014), published a review for the last interglacial highstand all over the world, taking in account 890 and 926 sites. but to treat them with analytical and statistical uniformity, authors apply some forcing, for example establish zero-meter as the eustatic sea level during the mis 5.5. the result is written in the title of the first paper: “relative sea-level fall since the last interglacial stage: are coasts uplifting worldwide?” using the paper by antonioli et al. (2006), authors wrote, for example: “… two highstands during mis 5e have been deduced, either from morphological analysis or deposits, in tunisia (jedoui et al., 2003), italy (antonioli et al., 2006)" while in antonioli et al. (2006), authors reported a tidal notch and a smoothed notch due to isostasy contribution, therefore due to only one highstand. evelpidu et al. (2012), returns to measure the same fishtanks (punta della vipera, lambeck et al., 2004) measured by pirazzoli (1976), again without the archaeologists (ignoring classical authors, included plinius the elder, columella and varro) measuring the wrong marker, a sea level of 2 ka bp at -50 cm, datum is confirmed by the predictive model ice 5g/selen. using the same model three years before (antonioli et al., 2009) the same author on the same site, predicted a sea level of -128 cm. this obviously creates a lot of confusion. roy and peltier 2018, published a new model for the mediterranean sea (ice 7g) but, as example, comparing the observational data for northern sardinia (grotta verde, -11 metres at 7300 yrs bp, by palombo et al., 2017) with prediction, the "stable" northern sardinia seems to be in subsidence. in addition, also here authors (from canada) established the sea level during roman age at -48 cm, without ever having seen a fishtank in the field. 3. remarks a model before being validated must be tested on the field in the stable areas, and possibly changed if in disagreement with observational data (see fig 1). references antonioli, f., ferranti, l., kershaw, s. (2006) a glacial isostatic adjustment origin for double mis 5.5 and holocene marine notches in the coastline of italy. quaternary international quaternary sea-level changes: contributions from the 32nd igc, 145146, 19-29. antonioli, f., ferranti, l., fontana, a., amorosi, a., bondesan, a., braitenberg, c., dutton, a., fontolan, g., furlani, s., lambeck, k., mastronuzzi, g., monaco, c., spada, g., stocchi, p. (2009) holocene relative sea-level changes and vertical movements along the italian coastline. quat. int., 221, 37 -51. evelpidou, n., pirazzoli, p., vassilopoulos, a., spada, g., ruggieri, g., tomasin, a., (2012) late holocene sea level reconstructions based on observations of roman fish tanks, tyrrhenian coast of italy. geoarchaeology 27 (3), 259-277. furlani s., antonioli f., gambin t., gauci r., ninfo a., zavagno e., micallef a., cucchi f. (2017a) marine https://doi.org/10.26382/aiqua.2018.aiquaconference notches on the maltese islands (central mediterranean sea). quaternary international, 439, 158168. furlani s., antonioli f., cavallaro d., chirco p., caldareri f., foresta martin f., gasparo morticelli m., monaco c., sulli a., quarta g., biolchi s., sannino g., de vita s., calcagnile l., agate m. (2017b) -coastal landforms and late quaternary relative sea level changes at ustica (sicily, southern italy). geomorphology, 299, 94-106. lambeck k., anzidei m., antonioli f., benini a, esposito e. (2014) -sea level in roman time in the central mediterranean and implications for modern sea level rise. earth planet. sci. lett., 224, 563-575. palombo m.r, antonioli f., lo presti v., mannino m., melis r., orru p., stocchi p., talamo s., quarta g., calcagnile l., deiana g., altamura s. (2017) the late pleistocene to holocene palaeogeographic evolution of the porto conte area: clues for a better understanding of human colonization of sardinia and faunal dynamics during the last 30 ka. quaternary international, 439, 117-140. doi: 10.1016/j.quaint.2016.06.014 pedoja, k., husson, l., regard, v., cobbold, p.r., ostanciaux, e., johnson, m.e., weill, p. (2011) relative sea-level fall since the last interglacial stage: are coasts uplifting worldwide?. earth sci. rev. 108, 1-15. pedoja, k., husson, l., johnson, m.e., melnick, d.,witt, c., pochat, s., nexer, m., delcaillau,b., pinegina, t., poprawski, y., authemayou, c., elliot,m., regard, v., garestier, f. (2014) coastal staircase sequences reflecting sea-level oscillations and tectonic uplift during the quaternary and neogene. earth sci. rev. 132, 13-38. pirazzoli, p. (1976) -sea level variations in the northwest mediterranean during roman times. science 194, 519-521. roy k., peltier w.r. (2018) relative sea level in the western mediterranean basin: a regional test of the ice-7g_na (vm7) model and a constraint on late holocene antarctic deglaciation quaternary science reviews, 183, 76-87. 12 antonioli f. fig 1 kurt lambeck seminar at ingv on may 2018. ms. received: may 15, 2018 final text received: may 22, 2018 amq 31(1) 05-19 mecozzi proof copy available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 31 (1), 2018, 5 19 late pleistocene mammal faunal assemblage from cava spagnulo (grottaglie, apulia, se italy) beniamino mecozzi 1-2, amel chakroun 3-4, henry baills 5-6, dawid adam iurino 1-2, raffaele sardella 1-2, donato coppola 7 1 dipartimento di scienze della terra, sapienza, università di roma, roma, italy 2 paleofactory, sapienza, università di roma, roma, italy 3 département de géologie, faculté des sciences de tunis, universitaire tunis el manar, tunis, tunisie 4 centre européen de recherches préhistoriques, umr 6569 du cnrs, tautavel, france 5 umr 7194 du muséum national d’histoire naturelle, paris, france 6 université perpignan, perpignan, france 7 dipartimento di scienze dell’antichità e del tardoantico, università degli studi di bari aldo moro, bari, italy corresponding author: b. mecozzi <beniamino.mecozzi@uniroma1.it> abstract: the quaternary sedimentary succession exposed at cava spagnulo, nearby the town of grottaglie (apulia, southern italy), is described for the first time. a preliminary list of the mammal remains from the upper part of the succession, has been compared with other pleistocene apulian sites. the identified taxa are represented by cranial and postcranial fragments and isolated teeth of bovids, cervids, equids, canids and lagomorph. in the same deposit also few mousterian stone tools have been found. the study of the mammal assemblage and the lithic tools suggest that the upper part of the succession exposed at cava spagnulo could be referred to the second part of the marine isotopic stage 3. keywords: fossil vertebrate, mediterranean, mousterian, mis 3 1. introduction the italian territory occupies a strategic position in the mediterranean area, which represents a crossroads between north western europe, central europe, eastern europe and north africa. the tectonic and volcanic activity during the quaternary produced a heterogeneous physiography, with the presence of several natural physical barriers, such the alps and apennines chains. the mountain ranges represent the main ecological barriers, respectively towards continental europe and along the peninsula, affecting the distributions of mammal fauna. furthermore, the latitudinal extension of italian territory causes a strong climatic gradient and produces regional differences in the climatic conditions, especially during the late glacial stages (gliozzi et al., 1997; bedetti et al., 2001; sala et al., 1992, sala & masini, 2007). during the late quaternary, the faunal assemblages were characterised by a strong regionalism, related to the presence of different dispersal paths and local environmental conditions (masini et al., 1990; sala et al., 1992, gliozzi et al., 1997; bedetti et al., 2001; sala & masini, 2007). the apulian region is located in the southern part of the italian peninsula, extending mainly along the latitudinal axis (130 km), and only 30 km along the longitudinal axis. on the basis of its peripheral position and physiography, some authors considered the occurrence in the apulian peninsula of a refugium area during the late pleistocene, due to supposed archaic nature of the vertebrate fauna (di stefano et al., 1994). on the contrary, other authors suggested that these mammal faunal associations could be chronologically referred to the late middle pleistocene (masini et al., 1990; sala et al., 1992). several vertebrate assemblages from the middle and late pleistocene deposits of apulia have been reported in previous research; these sites are mainly represented by caves and karst filling deposits (fig. 1). in the murge area, the middle part of apulia, previous studies were made in the following localities: contrada monticelli (mazza & varola, 1999; mecozzi et al., 2017), tana delle iene (conti et al., 2010; 2012), grotta della jena (guiscardi, 1873; anelli, 1956, 1960; cantelli, 1983), grotta sant’angelo (cassoli & tagliacozzo, 2001; casavola, 2005), grotta della masseria del monte (anelli, 1959), santa maria d’agnano (coppola, 2012), grotta laceduzza (coppola, 2012). several sites have been investigated in other area of apulia, in particular, in the salento peninsula, south of murge, coastal caves (e.g., grotta romaneli, grotta delle tre porte) or karst filling deposits (locally known as “ventarole”) near cursi and melpignano villages (de giuli, 1983; bologna et al., 1994; rustioni et al., 1994; sardella et al., 2005, among https://doi.org/10.26382/amq.2018.01 6 mecozzi b. et al. others), studied ossiferous breccias and terre rosse (red soils) constitutes the lower part of most of these deposits, followed by terre brune (brown soils) generally constitute the upper complexes of these deposits. due to the fragmentary stratigraphic and geomorphological evidence, these deposits are mainly dated biochronologically based on the large vertebrate faunal assemblages they contain (di stefano et al., 1992; bologna et al., 1994). the scattered outcrops of ossiferous breccias are characterized by the occurrence of large mammals, such as palaeoloxodon antiquus, stephanorhinus hemitoechus and hippopotamus amphibius, with a welldocumented presence of dama dama, which have been referred to the early late pleistocene (mis 5c-5a) (mis = marine oxygen stage) (di stefano et al., 1992). the goal of the present study is to offer the first description of the site, the list of fossil mammal remains and the artefacts collected in the late pleistocene deposits of cava spagnulo, located close to the town of grottaglie, in the murge area (apulia, se italy). a preliminary chronological framework for the upper part of the deposit (see the asterisik in fig. 1 for the location of the site within the apulian region) is also proposed on the basis of the artefacts and fossil mammal remains. 2. cava spagnulo in 1974 speleologists of the “gruppo speleologico salentino” discovered the site of cava spagnulo (fig. 1), previously known as cava del piano. the site is characterised by the presence of large mammal fossil bones associated with lithic industry of the middle palaeolithic (tramonti, 1974). tramonti (1974) claimed the presence of several mammal taxa, including proboscidean, which he referred to elephas sp. no figures of the fossils or of the lithic tools were provided. the site is located north-west of pizzuto hill, in an abandoned quarry on the “strada provinciale 73”, about 1,5 km from the town of grottaglie (taranto, apulia). the pleistocene deposit of cava spagnulo are at 190 m a.s.l. the outcrop, 20 m long and about 6 m thick, is exposed on a cliff of an old quarry opened in the cretaceous limestone that constitutes the local geological bedrock. the sedimentary succession includes either marine and continental fossiliferous facies, that suggest relative sea-level changes during sedimentation. the succession starts with a conglomerate layer, 40 cm thick (unit a), made up of calcareous cobbles (average size: 15 cm). this conglomerate grades into a chaotic boulder deposit, whose thickness ranges befig. 1 location of apulia (gray area) along the italian peninsula. the gargano, murge and salento area are indicated. the asterisk indicates the position of the studied site (cava spagnulo), while bold point indicate other localities previously studied in late pleistocene deposits: ingarano (ing.), grotta paglicci (g.p.), grotta della masseria del monte (g.m.m.), grotta della jena (g.j.), grotta delle mura (g.m.), tana delle iene (t.i.), grotta sant’angelo (g.s.a.); avetrana (avet.), cardamone (card.), sternatia (ster.), grotta del cavallo (g.c.), fondo cattiè (f.c.), san sidero (s.s.) and melpignano (mel.). grotta del sarcofago (g.s.r.), grotta delle striare (g.s.t.), grotta romanelli (g.r.) and grotta delle tre porte (g.t.p.). 7 mammal fauna from cava spagnulo tween 100 and 250 cm (unit b), made up of calcareous boulders (average size of clasts: 20 cm to 30 cm). this part of the succession is covered by a discontinuous marine layer, 0-50 cm thick (unit c), lenticular and patchy, that contains a set of marine fauna belonging to echinoidea, gastropoda, bivalvia (pectinidae), haexanauplia (balanidae), anthozoa, foraminifera, and is marked by the presence of numerous specimens of cladocora caespitosa. the marine deposits are covered locally by crosslaminated sands (unit d), from 20 to 25 cm thick. a thin calcitic crust (unit e), from 5 to 30 cm thick, overlies unit d. the subsequent part of the exposed succession is made up of reddish continental deposits, represented, from the base upwards, by: clast-supported breccia (from 150 to 250 cm thick) (unit f) matrix-supported breccia with vertebrate remains and lithic industry (from 70 to 120 cm thick) (unit g) reddish clay (from 80 to 100 cm thick) (unit h). 3. materials and methods the fossil remains described in this paper were discovered during two different field surveys, in 1974 and 1996, in the quarries of grottaglie area. the first collection was recovered by a. tramonti, and nowadays the fossil materials are housed in the technical institute commercial galilei-costa (lecce), with the progressive catalogue number cdp76-n. the second field survey was realised by a research team of the department of earth science and geoenvironmental, univerisity of bari, and the fossil remains were stored in the museum of preclassical culture of the southern murge (ostuni, brindisi), catalogued with the progressive number cdp96-n. according to original information about previous field activities, all the fossil materials were collected in deposits corresponding to the unit g of the succession described in this paper. according to von den driesch (1976), the measurements of the studied specimens have been taken with digital callipers to the nearest 0.01 mm. in order to evaluate the body-size variability of equus ferus, we analysed e. ferus teeth sample from cava spagnulo and from several late pleistocene sites from apulian peninsula by means of log-ratio diagrams (simpson, 1941; simpson et al., 1960). the dental variables considered are l (length) and w (width) for the upper teeth p4, p2 and p4-m3. we chose e. ferus coming from the apulian peninsula sites that are chronologically referred to mis 3 (tana delle iene, conti et al., 2010; fondo cattìe, corridi, 1987; level f of grotta del cavallo, sarti et al., 1998; grotta laceduzza) as reference species and, in addition to e. ferus from cava spagnulo, we plotted the late pleistocene wild horse fig. 2 mammal remains from layer f of cava spagnulo: bos primigenius: a1-a3: right hemimandible (cdp96-75); b1-b3: right lower third molar (cdp96-77); c1-c3: left upper second molar (cdp96-79); cervus elaphus: e1-e3: right first lower molar (cdp96-78); canis lupus: d1d3: right hemimandible (cdp96-96). buccal (-1), lingual (-2) and occlusal (-3) views. scale bar 3 cm. data from apulian peninsula sites distinguished by age: mis 5 (grotta delle 3 porte, san sidero, melpignano, level h-i of grotta del cavallo, sarti et al., 2002); mis 4 (grotta dei giganti); mis 2 (santa maria d’agnano riparo esterno, grotta paglicci, boscato, 1994); mis 1 (grotta delle mura, bon & boscato, 1993). the faunal assemblage was compared with other late pleistocene sites of the apulian peninsula (fig. 1), such as ingarano based on literature data (petronio et al., 1996; petronio & sardella, 1998; iurino, 2014), grotta paglicci (boscato, 1994), grotta della masseria del monte (anelli, 1959), grotta delle mura (bon & boscato, 1993), grotta della jena (anelli, 1956), tana delle iene (conti et al., 2012), grotta sant’angelo (cassoli & tagliacozzo, 2001; casavola, 2005); avetrana (petronio et al., 2008; mecozzi & bartolini lucenti, 2018), cardamone (rustioni et al., 2003), sternatia (rustioni et al., 1994), grotta del cavallo (sarti et al., 1998; sarti et al., 2002, boscato & crezzini, 2012; zanchetta et al., 2018), fondo cattiè (corridi, 1987), melpignano (bologna et al., 1994), san sidero (de giuli, 1983; iurino et al., 2013), grotta del sarcofago (di stefano et al., 1992), grotta delle striare (malviglia, 1955; di stefano et al., 1992), grotta romanelli (blanc, 1920; 1928; sardella et al., 2014; 2018) and grotta delle tre porte (cardini, 1958). we also considered morphological and morphometric data of the mammal remains stored in the following institutions: “paleofactory laboratory, department of earth sciences, sapienza, university of rome” (melpignano, san sidero and ingarano); “italian institute of human paleontology (isipu) of anagni laboratory (frosinone, latium) (san sidero, grotta dei giganti, grotta delle tre porte); “paleontology museum of the department of the earth science of turin university” (turin, piedmont) (san sidero); “technical institute commercial galilei-costa (lecce, apulia) (cardamone); “museum of preclassical civilization of the southern murge (ostuni, brindisi), (grotta laceduzza, santa maria d’agnano riparo esterno). in order to avoid the confusion that arise in the comparison of the literature data, the "unit g", interested by the presence of studied fossils and artefacts, will be called "level g" in the following chapthers. 3.1. measurements abbreviations upper and lower dentition: l, length; w, width. long bones: bp: breadth of proximal end; dp: depth of proximal end; sd: smallest breadth of diaphysis; wsd; smallest width of diaphysis, bd, breadth of distal end; dd: depth of distal end, dsfo, depth above the olecranic fossa; bpc, breadth across the coronoid process; bfar, breadth of radius articular surface; sdo, smallest depth of the olecranon. scapula: bg, breadth of glenoid cavity; lg, length of glenoid cavity; glp, greatest length of the articularis process; slc, smallest length of the collum scapulae. calcaneous: l, length; w, width; h, height. metapodial and phalange: tl: total length; bp: breadth of proximal end; dp: depth of proximal end; sd: smallest breadth of diaphysis; wsd; smallest width of diaphysis; bd, breadth of distal end; dd: depth of distal end. 4. systematic palaeontology order artiodactyla, owen 1848 family bovidae, (gray, 1821) subfamily bovinae, (gray, 1821) genus bos, linnaeus, 1758 species bos primigenius, bojanus, 1827 material examined: two right hemimandible fragments (cdp96-75, cdp96-76) (fig. 2), one left hemimandible fragment (cdp76-1), one right m3 (cdp96-77) (fig. 2), one left m2 (cdp96-79) (fig. 2), one third phalanx (cdp96-112), one scaphoid (cdp96-113), one atlas (cdp96-122) and a sacrum (cdp96-123) (see measurements in table 1). remarks: the permanent teeth show a slight wear of the cusps and therefore were referred to adult specimens. despite the absence of well-preserved horn remains, the morphology of the dental and postcranial elements point to bos primigenius. all the fossils have large dimensions and their size is comparable with other aurochs specimens from the late pleistocene of the apulian peninsula, such as grotta paglicci (boscato, 1994), grotta delle mura (bon & boscato, 1993), avetrana (pandolfi et al., 2013), fondo cattiè (corridi, 1987), ingarano, san sidero and melpignano. family cervidae goldfuss, 1820 subfamily cervinae, goldfuss, 1820 genus cervus, linnaeus, 1758 species cervus elaphus, linnaeus, 1758 material examined: one left maxillary fragment (cdp76-2), one right m1 (cdp76-4), one left m2 (cdp765), one right (cdp96-11, cdp76-3) and one left (cdp766) hemimandible fragments, one right m1 (cdp96-78) (fig. 2), one humerus fragment (cdp96-99), one right radius (cdp96102), one right tibia fragment (cdp96101), one left calcaneus (cdp96-103) and one right first phalanx (cdp96-104) (see measurements in table 2). remarks: the length of the cdp96-78 is within the range of the other late pleistocene samples of the apulian peninsula. additional measures of the most complete postcranial elements can be found in table 2, and their size are similar to other specimens coming from the late pleistocene of the apulia peninsula, as grotta del cavallo (sarti et al., 2002), fondo cattiè (corridi, 1987), ingarano, san sidero and melpignano. no antlers were found. 8 tab. 1 measurements of upper and lower dentition of bos primigenius from cava spagnulo. specimen n° tooh length width cdp96-75 m1 32.0 19.8 cdp96-75 m2 26.3 16.2 cdp96-77 m3 41.1 13.3 cdp96-79 m2 28.3 21.1 mecozzi b. et al. order perissodactyla, owen 1848 family equidae gray, 1821 subfamily equinae, steinmann & döderlein, 1890 genus equus, linnaeus, 1758 species equus ferus, pallas, 1775 material examined: a left maxillary fragment (cdp76-7), two isolated incisor roots (cdp96-80, cdp96 -81), one left i3 (cdp96-83), one right m2 (cdp96-86), one right i2 (cdp96-82), one right i2 (cdp96-84), one right i3 (cdp96-98), one left i3 (cdp96-97), one right p2 (cdp96-92), one left p2 (cdp96-90), one left p4 (cdp9694), one left m1 (cdp96-91, cdp96-95), one right m2 (cdp96-87, cdp96-88), one right m3 (cdp96-85), one left m3 (cdp96-93) and one right hemimandible fragment with m1 and m2 (cdp96-89) (see measurements in table 3) (fig. 3). remarks: this species is the relatively better represented mammal in the assemblage. the sample is constituted especially by both isolated lower and upper teeth. the only post-cranial bone attributed to this taxon is a fragmented proximal epiphysis of metapodial (cdp96-100). our metrical analysis of dentition shows that the dimensions of the cava spagnulo teeth (tab. 3) are closer to other e. ferus specimens from the late pleistocene sites of apulia peninsula chronologically referred to mis 4 (e.g., grotta dei giganti) and mis 2 (e.g., grotta paglicci). the medium-sized and the morphological features allow to ascribe this material to equus ferus. 9 tab. 2 measurements of lower dentition, humerus, tibia, radius, calcaneus and phalanx of cervus elaphus from cava spagnulo. specimen n anatomical portion length width cdp76-4 m1 27.3 16.1 cdp76-5 m2 23.7 17.2 cdp96-78 m1 24.6 14 cdp76-7 m2 22.3 9.2 bd dd sd wsd cdp96-99 humerus 40.8 35.2 18.7 22.4 bd dd sd wsd cdp96-101 tibia 40.9 32.3 28 23.2 bp dp sd wsd cdp96-102 radius 17 26.6 12.3 20.7 l w h cdp96-103 calcaneus 84.9 30.1 29.6 tl bp dp sd wsd bd dd cdp96-104 i phalanx 42 14.7 18.5 11.7 13.6 13.5 12.2 specimen n tooth length width cdp96-82 i2 14.2 11.2 cdp96-84 i2 13.5 11.4 cdp96-83 i3 13.7 12.1 cdp96-90 p2 32.6 16.3 cdp96-92 p2 32.6 16.5 cdp96-94 p4 30.4 29 cdp96-91 m1 27.2 17.7 cdp96-95 m1 26.9 16.6 cdp96-89 m1 26.9 14.9 cdp96-89 m2 27.4 17.6 cdp96-87 m2 29.8 18.5 cdp96-88 m2 29.9 18.6 cdp96-85 m3 34 14.8 cdp96-93 m3 30.2 15.2 cdp96-86 m2 30 27.5 tab. 3 measurements of upper and lower dentition of equus ferus from cava spagnulo. mammal fauna from cava spagnulo order carnivora, bowditch, 1821 family canidae, fischer von waldheim, 1817 subfamily caninae, fischer von waldheim, 1817 genus canis, linnaeus, 1758 species canis lupus, linnaeus, 1758 material examined: a right hemimandible fragment (cdp96-96) (fig. 2), isolated left p4 (cdp96-276) and some postcranial elements such as proximal epiphysis of scapula (cdp96-111), right second metacarpal (cdp96-110), left second metatarsal (cdp96-109), distal epiphysis of metapodial (cdp96-108) and first phalanx (cdp96-107), (see measurements in table 4). remarks: cdp96-96 preserved the p4, with a protocone, a distal accessory cusp and well-marked labial cingulum; the m1 displays the protoconid higher than paraconid, and posteriorly elongated talonid forming a continuous flatter surface with the m2; the second molar is bean-squared. taking into account the wear of the cusps and the fusion degree of the epiphyses, the bio 10 fig. 3 equus ferus from layer f of cava spagnulo: a1-c1: right lower third molars (cdp96-85); a2-c2: right upper second molar (cdp9686); a3-c3: right lower second molars (cdp96-87); a4-c4: cdp96-88 right lower second molars; a5-c5: lower left first molar (cdp96-91); a6c6: right hemi-mandible (cdp96-89). buccal (a), lingual (b) and occlusal (c) views. scale bar 3 cm. mecozzi b. et al. material examined: one distal epiphysis of right tibia (cdp96-131). remarks: only the fragmented tibia has been attributed to the wild rabbit. the size and the features of this specimen, such as thickness of distal epiphysis and shallow medial malleolar sulcus, are typical of the wild rabbit. the biometric measurements (bp 8,4; dp 5,4) show that the specimen from cava spagnulo falls in the size variability of both extant and late pleistocene rabbits. 5. archaeological data in 1996, during a field survey in cava spagnulo, several artefacts were discovered from the level g (fig. 4). the scarce industry is mostly on flinty limestone, raw material very common in the deposits of the murge region, such as donna lucrezia (ceglie messapica), monte la morte (ostuni), grotta laceduzza (ostuni) and tana delle iene (ceglie messapica) (coppola, 2012). in addition to retouched tools, several flacking debris were found, indicating that the stone knapping was performed locally. among the recovered tools, there are two scrapers and one point. the first one shows a double straight side on lamellar flake (fig. 4 a1-a5). the second is a straight transverse scraper on large flake (fig. 4 b1-b5). the last tool is a point platform remnant, with an asymmetric data of dental and postcranial materials the canid sample was attributed to a large adult specimen. the teeth from cava spagnulo are similar in size and morphology to large wolves possibly referable to glacial stage documented in the apulian peninsula (e.g, cardamone, avetrana, mecozzi & bartolini lucenti, 2018). genus vulpes, linnaeus, 1758 species vulpes vulpes, linnaeus, 1758 material examined: right and left fragment (cdp96114, cdp96-115) of ulna and right and left (cdp96-116, cdp96-130) distal epiphysis of tibia (see measurements in table 5). remarks: the red fox is represented only by few postcranial remains referred to an adult specimen. the measurements taken on these postcranial elements and their morphological features fall into the body-size variability of both extant and late pleistocene apulian foxes (e.g., ingarano, tana delle iene). order lagomorpha, brandt, 1855 family leporidae, gray, 1821 subfamily leporinae, trouessart, 1880 genus oryctolagus, lilljeborg, 1873 species oryctolagus cuniculus, linnaeus, 1758 11 specimen n anatomical portion length width                cdp96-96 p4 15.1 7.4 cdp96-96 m1 27.4 10.6 cdp96-96 m2 11.5 7.9 cdp96276 p4 15.4 7.2 bg lg glp slc cdp96-111 scapula 22.6 26.8 37.5 30.2 tl bp dp sd wsd bd dd cdp96-108 metapodial 10.6 11.3 cdp96-109 ii metarcapal 72.6 13.3 12.4 7.7 7.3 11.2 10.8 cdp96-110 ii metatarsal 9.1 15.7 cdp96-107 i phalanx 31.5 10.3 9.7 6.5 6.4 8.6 6.5 tab. 4 measurements of lower dentition, scapula, metapodial and phalanx of canis lupus from cava spagnulo. specimen n anatomical portion bpc dsfo bfar sdo cdp96-114 ulna 7.5 9.6 9.1 cdp96-115 ulna 7.5 10.6 6.7 5.1 bd dd cdp96-116 tibia 13.4 9.3 cdp96-130 tibia 14.2 9.9 tab. 5 measurements of ulna and tibia of vulpes vulpes from cava spagnulo. mammal fauna from cava spagnulo metrical point on crested flake (fig. 4 c1-c5). the typological analysis of the artefacts clearly provides an attribution to mousterian faces. 6. results the studied materials are in poor state of preservation. most of them are partially enveloped by a reddish thin limestone crust and in some specimens with evidence of surface abrasions. the bones, which are represented only by adult specimens, were found fragmented and disarticulated. the two collections include 300 fossil remains; 52 of them have been identified and attributed to 6 different mammalian species; 248 are fragmented and not diagnostic, most of them are long bone shaft fragments. bite marks, rodent gnaw marks and clear evidence of human butchering and exploiting activity have not been recognized on the osteological materials. 7. discussion the faunal assemblage of cava spagnulo coming from the breccia level g includes the following species: bos primigenius, cervus elaphus, equus ferus, canis lupus, vulpes vulpes and oryctolagus cuniculus. tramonti (1974) claimed the occurrence of elephants and hares, but no evidence of these taxa has been found in the palaeontological collections stored at technical institute commercial galilei-costa (lecce). in the faunal assemblage of cava spagnulo, the carnivores are represented only by canids, wolves and red foxes. these species are characterised by a wide geographical distribution and ecological tolerance, which allow them to occupy several different habitats (ungar, 2010). in the last decades, a number of studies focused on the dispersal trends and body-size variation of canis lupus in relation to global climatic changes during the middle-late pleistocene have been published (argant, 12 fig. 4 artefacts coming from the layer g of cava spagnulo. a1-a5 and b1-b5: flinty limestone scrapers. c1-c5: flinty limestone point. scale bar 3 cm. mecozzi b. et al. 2009; brugal & boudadi-maligne, 2011; bertè & pandolfi, 2014; sardella et al., 2014; sansalone et al., 2015; mecozzi & bartolini lucenti, 2018). a general consensus has not been reached among the specialists; therefore some of them suggested that c. lupus went through an increase of body size, culminating to very large wolves present during the last glacial stage (sansalone et al., 2015; mecozzi & bartolini lucenti, 2018). nowadays, the presence of a large-sized wolf in apulian peninsula is reported only in deposits chronologically referred to the end of mis 3 or mis 2, such as grotta paglicci (boscato, 1994), avetrana (mecozzi & bartolini lucenti, 2018), cardamone (mecozzi & bartolini lucenti, 2018), grotta della masseria del monte (anelli, 1959) and grotta della jena (guiscardi, 1873). the set-up of an implemented database with a more detailed chronological framework of the apulian fossiliferous sites is needed to verify the different evolutionary scenarios of c. lupus. the studied faunal assemblage is mostly represented by the wild horse (e. ferus), whose presence suggests open forested steppes and relatively cold climatic conditions (rustioni et al., 2003). the occurrence of a large horse characterises the salentine faunal assemblages (conti et al., 2010), in some cases together with the smaller equus hydruntinus (grotta delle mura, bon & boscato, 1993; grotta paglicci, boscato, 1994, melpignano, bologna et al., 1994; sternatia, rustioni et al., 1994; tana delle iene, conti et al., 2012). a number of studies focused on the size variability of the wild horse from the middle-late pleistocene (de giuli, 1983; corridi, 1987; boscato,1994, 2004; conti et al., 2010), leading to consider a trend from the largesized specimens of the middle-late pleistocene sites from the italian peninsula (e.g., malagrotta, torre in pietra, melpignano) to the small-sized specimens from the late glacial (mis 2) and earliest holocene (mis 1) from italian peninsula sites. in particular, corridi (1987) suggested that body-size of the wild horse remains from fondo cattìe (mis 3) was smaller than that of the fossil sample coming from san sidero (mis 5) and grotta paglicci (mis 2). except for m1, the teeth size of wild horses chronologically referred to mis 5 are larger than those of apulian specimens from mis 4 to mis 1 (fig. 5). the specimens from cava spagunlo are similar in size to those referred to mis 4 and mis 2. according to many authors (de giuli, 1983; boscato,1994; 2004; conti et al., 2010), the horse remains from the earliest holocene (mis 1) are smaller in size than those from the late pleistocene (fig. 5). the studied materials included also the european rabbit (o. cuniculus) and aurochs (b. primigenius), which had a preference for temperate conditions, but they have been reported from the palaeontological sites of the apulian peninsula referred to the late pleistocene glacial stages, with dry and cold open environment such as avetrana (bed8, petronio et al., 2008), grotta della masseria del monte (anelli, 1959), sternatia (rustioni et al., 1994), grotta paglicci (boscato, 1994) and cardamone (rustioni et al., 2003). at cava spagnulo, also the red deer (c. elaphus) is poorly represented. this cervid inhabits open deciduous woodland, coniferous woodland and mediterranean scrub. the red deer is a very common element in the faunal association from the late pleistocene sites of the apulian peninsula, and it has been reported in both glacial and periglacial stage associations (grotta paglicci, boscato, 1994; ingarano, petronio et al., 1996; petronio & sardella, 1998; grotta della masseria del monte, anelli, 1959; grotta della jena, anelli, 1956, 1960; grotta sant’angelo, cassoli & tagliacozzo, 2001; casavola, 2005; avetrana, petronio et al., 2008; fondo cattiè; corridi, 1987; grotta del cavallo, sarti et al.,1998; 2002; melpignano, bologna et al., 1994; san sidero, de giuli, 1983; tana delle iene, conti et al., 2012; cardamone, rustioni et al., 2003; grotta delle tre porte, cardini, 1958). furthermore, other species typical of temperate woodland were widely diffused in the apulia peninsula during the late pleistocene (minieri et al., 1993), such as the wild boar (sus scrofa), the roe deer (capreolus capreolus), the european wildcat (felis sylvestris) and the eurasian badger (meles meles). these species were not found at cava spagnulo. the composition of the mammal association from the level g of cava spagnulo differs from those reported by the ossiferous breccia from the apulian peninsula, especially along the southern adriatic coastline (blanc, 1958; di stefano et al., 1992). these deposits are characterized by the occurrence of large mammal fauna that included hippopotamus amphibius, stephanorhinus hemitoechus, palaeoloxodon antiquus and middle-size cervid dama dama (tab. 6). these taxa have been considered as typical elements of warm-temperate environment of the early late pleistocene faunal assemblages (mis 5c 5a) of the apulian sites, such as grotta del sarcofago, grotta delle striare, grotta romanelli and grotta delle tre porte (blanc, 1958; di stefano et al., 1992). the chronological attribution of these ossiferous breccias has been strongly debated among different authors (masini et al., 1991; sala et al., 1992), suggesting that these fossil remains of mammals could be referred to late middle pleistocene. the major issue was about the specific attribution of small-sized canid remains, which have been referred for a long time to early -middle pleistocene mosbach the wolf c. mosbachensis (masini et al., 1991; sala et al., 1992). despite its reduced body-size and its peculiar morphologic characters, the wolf from grotta romanelli has been recently referred to canis lupus (sardella et al., 2014). however, the mammal fauna, indicating warm-temperate climate, became less frequent from the italian peninsula palaeontological record when cold and less humid climatic conditions established (petronio et al., 2007), and it disappeared at the climax of the last glacial stage (mis 2) (rustioni et al., 2003). in particular, the last occurrences of fallow deer and narrow-nosed rhinoceros in southern italy are documented in the ingarano site, referred to the mis 3 (about 40 ka bp) (petronio et al., 1996; petronio & sardella, 1998). albeit the small fossil sample recovered in the level g from cava spagnulo led us to consider the chronological attribution with caution, the faunal assemblage would appear to be characterised by the occurrence of large-sized wolf and a medium-sized wild horse. the remains of these species show different size and mor 13 mammal fauna from cava spagnulo phology than the specimens found in several early late pleistocene sites of apulia (e.g., grotta romanelli, san sidero, melpignano). therefore, a depositional time span referred to the early late pleistocene (mis 5c-5a) can be excluded (tab. 6). in addition, the hippo (hippopotamus amphibius), the narrow-nosed rhinoceros (stephanorhinus hemitoechus) and the fallow deer (dama dama) were not found at cava spagnulo. many vertebrate assemblages from the late pleistocene deposits of apulia area have been described in literature, but only some of them assume a significant role to reconstruct the biochronological framework of the apulian peninsula during the late pleistocene (tab. 6). the long and well-preserved grotta paglicci stratigraphic sequence included 26 archaeological levels referred to the middle-upper palaeolithic (late pleistocene) (palma di cesnola, 1991, boscato, 1994). in particular, artefacts discovered in the levels 24-22 have been attributed to the aurignacian-gravettian facies and, in the same levels, the mammal fauna is dominated by equids (e. ferus and e. hydruntinus) (boscato, 1994). the grotta del cavallo succession is divided in 12 levels laying on a marine terrace referred to tyrrhenian (mis 5) (level n). the mammal assemblage recovered in the levels h-i is dominated by e. ferus followed by cervids (c. elaphus and d. dama) (sarti et al., 2002). most of the fossil sample discovered from the level f has been attributed to b. primigenius and cervids (c. elaphus and d. dama) (sarti et al., 1998). finally, the mammal fauna reported from the level e was dominated by b. primigenius, and followed by e. ferus and c. elaphus (boscato & crezzini, 2012). the faunal assemblage reported from the cardamone site indicates cold climatic conditions, including typical elements of the mammuthus-coelodonta faunal complex (mammuthus primigenius, coelodonta antiquitatis, equus ferus and crocuta crocuta). other taxa were discovered at cardamone site, which have been referred to a more temperate autochthonous fauna (b. primigenius, c. elaphus, l. europaeus and oryctolagus cuniculus) (rustioni et al., 2003). few fossiliferous deposits were described from the murge area. the late palaeolithic and neolithic grotta sant’angelo deposit was discovered in 1930 (casavola, 2005). the stratigraphic succession consisted of red soil, in the lower part, and brown soil, in the upper part. in the faunal assemblage of the lower levels, the cervids were well represented while few specimens were attributed to equids (cassoli & tagliacozzo, 2001; casavola, 2005). a fossiliferous deposit of grotta della jena included 14 fig. 5 log-ratio diagram based on selected dental variables in the studied sample of equus ferus from cava spagnulo (cs), as well as in other late pleistocene specimens from apulian peninsula sites (mis 5, grotta delle tre porte, san sidero, melpignano, level h-i of grotta del cavallo; mis 4, grotta dei giganti, grotta laceduzza; mis 2, santa maria d’agnano riparo esterno, grotta paglicci; mis 1; grotta delle mura) as compared to equus ferus materials from apulian peninsula sites referred to mis 3 (tana delle iene, fondo cattìe, level f of grotta del cavallo). mecozzi b. et al. 15 tab. 6 late pleistocene mammal taxa from selected localities of the apulian peninsula: 1) ingarano (ing.), 2) grotta paglicci (g.p.), 3) grotta della masseria del monte (g.m.m.), 4) grotta della jena (g.j), 5) grotta sant'angelo (g.s.a.), 6) tana delle iene (t.i.), 7) cava spagnulo (c.s.), 8) cardamone (card.), 9) grotta del cavallo (g.c.), 10) grotta del sarcofago (g.s.r.), 11) grotta delle striare (g.s.t.), 12) grotta romanelli (g.r.) and 13) grotta delle tre porte (gtp). mammal fauna from cava spagnulo two levels separated by a thick stalagmite crust (anelli, 1960; cantelli, 1983). most of the fossil sample of the mammals recovered from the red soil (lower level) has been referred to cervids (anelli, 1960). the site of the grotta della masseria del monte site was discovered in 1942 (anelli, 1959). the deposit included red soil in the lower part and brown soil in the upper part (anelli, 1959). the mammal faunal discovered by lower level was dominated by cervids. the stratigraphic succession of tana delle iene includes 9 levels, three of which are tephra (us9, us4 and us 1) (giaccio & coppola, 2000). the ash levels (us9 and us4) were correlated to pyroclastic products of the campi flegrei, respectively dated <60000 bp and >37000 bp (giaccio & coppola, 2000). the upper level (us1) was correlated to codola plinian eruption (giaccio et al., 2008). the faunal assemblage recovered from us8 of tana delle iene was dominated by d. dama, followed by b. primigenius (conti et al., 2012). despite the lack of the main representatives of the last glacial stage assemblage (m. primigenius, c. antiquitatis), the structure of the studied association is closer to that reported from several sites of the apulian peninsula chronologically referred to the latest interglacial and earliest last glacial stage, such as cardamone (rustioni et al., 2003), grotta paglicci (boscato 1994, 2004), grotta della jena (anelli, 1956; 1960) and grotta della masseria del monte (anelli, 1959). finally, the typological analysis of the tools recovered from level g enable to attribute the lithic industry to the mousterian facies. in addition, associated to the faunal assemblage, tramonti (1974) reported the presence of lithic artefacts referable to middle palaeolithic. the small number of the artefacts prevents to make the technological characterization of the lithic complex. however, the typology of the studied tools is closer to those reported from several sites of the murge, such as tana delle iene (giaccio & coppola, 2000) and grotta laceduzza (coppola, 2012). in particular, the lithic complex from the grotta laceduzza was recently described (coppola, 2012). these artefacts show close affinities to those found in the level f of the grotta del cavallo (mis 3) (coppola, 2012). the raw material is represented by flinty limestone, typical of murge, like the material observed in donna lucrezia (ceglie messapica, brindisi), grotta laceduzza (san michele salentino, brindisi), monte la morte (ostuni, brindisi) and tana delle iene (ceglie messapica, brindisi) (coppola, 2012). due to the closer affinity to grotta laceduzza and tana delle iene sites and their geographic position (murge), it would be possible to hypothesize that the level g of the cava spagnulo could be referred to the latest interglacial part of mis 3. 8. conclusion the description of the pleistocene deposit exposed at cava spagnulo is here reported for the first time. in particular, only the upper part of the local quaternary succession was sampled, yielding numerous fragmented fossil remains and some artefacts typologically referable to a mousterian facies. the typology and the raw material of the studied lithic complex are closer to those reported from several sites of the murge date chronologically to mis 3, such as tana delle iene (giaccio & coppola, 2000) and grotta laceduzza (coppola, 2012). the scantiness of the fossil record suggests that such a framework needs to be verified after new field work with a more detailed stratigraphic analysis of the site. at present, the studied faunal assemblage includes bos primigenius, cervus elaphus, medium-sized equus ferus, relatively large-sized canis lupus, vulpes vulpes and oryctolagus cuniculus. tramonti (1974) claimed the occurrence of proboscideans (elephas sp.) from cava spagnulo, but no fossil material has been found in the studied paleontological collections, to confirm this presence. the occurrence of palaeoloxodon or mammuthus could be of great biochronological value, being related to different paleoenvironmental scenarios and chronology (see braun & palombo, 2012 for the discussion). only general taphonomical considerations can be carried on the faunal remains which show no evidence of human activity nor bite marks of carnivores or rodents. in addition, the remains show no evidence of surface alterations due to weathering. the small number of fossil sample prevents to reconstruct the palaeoenvironmental conditions of the level g of the cava spagnulo. however, the pollen analysis of hyena coprolites coming from the tana delle iene suggested open lowlands, dominated by steppe and grassland, with sporadic mesophilous and thermophilous trees for the murge during the mis 3 (petrucci et al., 2005; gatta et al., 2016). the open and dry environment with scarce forest is typical of the second part of the late pleistocene (mis 3-2) in southern italy (petrucci et al., 2005; renault-miskovsky et al., 2011; 2015; gatta et al., 2016, berto et al., 2017). finally, it would be possible to hypothesize that the level g of the cava spagnulo could be chronologically referred to the latest interglacial stage (mis 3). acknowledgements we wish to thank to the soprintendenza archeologia, belle arti e paesaggio delle province di brindisi, lecce e taranto. the authors are indebted to the dott. mariella michele, own of the quarry known as cava spagnulo and to the ostuni municipal authorities for their support of this research. we wish to thank a. sposato and the two referees, p. mazza and m. tropeano, for the critical revision of the manuscript that greatly improved the research work. the authors wish to thank i. mazzini, l. bellucci, f. strani and j. conti for their useful suggestions and support. we wish to thank m. pavia (“museo di paleontologia del dipartimento di scienze della terra dell’univeristà di torino), a. mazzotta, c. viva (i.t.c. “galileo-costa”), l. bruni, s. grimaldi, s. pianese longo 16 mecozzi b. et al. (isipu) for granting access to fossil mammal collections from late pleistocene apulian sites and the opportunity to study they. we also acknowledge v. stasolla, r. marchese, v. calderone, g. lippolis and f. palazzo for their valuable help in during laboratory activities. the study has been supported by sapienza research grant (ricerche universitarie 2015, resp. r. sardella) and grandi scavi 2016 (sapienza università di roma, resp. r. sardella). references anelli f. (1956) un raro reperto di stambecco nella grotta della jena presso castellana (bari). atti del 7 congresso nazionale di speleologia, 105-107. anelli f. (1959) prime ricerche paleontologiche della grotta della masseria del monte conversano murge in bari. le grotte d’italia, 3, 1-34. anelli f. (1960) eccezionale bottino di caccia nella grotta della jena. l’olmo, 5(1), 3-6. argant a. (2009) biochronologie et grands mammifères au pléistocène moyen et supérieur en europe occidentale: l’apport des canidés, des ursidés et des carnivores en général. quaternaire. revue de l'association française pour l'étude du quaternaire, 20(4), 467-480. bedetti c., palombo m.r., sardella r. (2001) last occurrences of large mammals and birds in the late quaternary of the italian peninsula. the world of elephant international congress, rome, 701703. berté d.f., pandolfi l. (2014) canis lupus (mammalia, canidae) from the late pleistocene deposit of avetrana (taranto, southern italy). rivista italiana di paleontologia, 120(3), 367-379. berto c., boscato p., boschin f., luzi e., ronchitelli a. (2017) paleoenvironmental and paleoclimatic context during the upper palaeolithic (late upper pleistocene) in the italian peninsula. the small mammal record from grotta paglicci (rignano garganico, foggia, southern italy). quaternary science reviews, 168, 30-41. blanc g.a. (1920) grotta romanelli i. stratigrafia dei depositi e natura e origine di essi. archivio per l'antropologia e la etnologia, 50, 1-39. blanc g.a. (1928) grotta romanelli ii. dati ecologici e paletnologici. archivio per l'antropologia e la etnologia, 58, 1-49. blanc a.c. (1958) industria musteriana su calcare e su valve di meretrix chione associata con fossili di elefante e rinoceronte, in nuovi giacimenti costieri del capo di leuca. quaternaria, 5, 308-313. bojanus l.h. (1827) de uro nostrate eiusque sceleto commentatio scripsit et bovis primigenii sceleto auxit. nova acta physico-medica academiae caesareae leopoldino-carolinae naturae curiosorum, 13(2), 411-478. bologna p., di stefano g., manzi g., petronio c., sardella r., squazzini e. (1994) late pleistocene mammals from the melpignano (le) “ventarole”: preliminary analysis and correlations. bollettino della società paleontologica italiana, 33(2), 265-274. bon m., boscato p. (1993) analisi paleontologica e paleoecologica di macro e micromammiferi dei livelli romanelliani e mesolitici della grotta delle mura (monopoli, bari). quaternaria nova, 3, 53104. boscato p. (1994) grotta paglicci: la fauna a grandi mammiferi degli strati 22-24 (gravettiano anticoaurignaziano). rivista di scienze preistoriche, 46, 145-176. boscato p. (2004) i macromammiferi dell’aurignaziano e del gravettiano antico di grotta paglicci. paglicci l’aurignaziano e il gravettiano antico. claudio grenzi ed., foggia, 49-62. boscato p., crezzini j. (2012) middle-upper palaeolithic transition in southern italy: uluzzian macromammals from grotta del cavallo (apulia). quaternary international, 252, 90-98. bowdich t.e. (1821) an analysis of the natural classication of mammalia for the use of students and travellers. j. smith, paris, pp. 115. brandt j.f. (1855) beiträge zur nahern kenntniss der säugethiere russlands. mem. acad. imp. st. petersbourg ser, 69, 1-375. braun i.m., palombo m.r. (2012) mammuthus primigenius in the cave and portable art: an overview with a short account on the elephant fossil record in southern europe during the last glacial. quaternary international, 276, 61-76. brugal j.p., boudadi-maligne m. (2011) quaternary small to large canids in europe: taxonomic status and biochronological contribution. quaternary international, 243(1), 171-182. cantelli c. (1983) la grotta della jena (bari): un esempio di trappola paleontologica. le grotte d’italia, 11, 165-171. cardini l. (1958) prime determinazioni delle faune dei nuovi giacimenti costieri musteriani del capo di leuca. quaternaria, 5, 314-315. casavola e. (2005) nota preliminare sui reperti faunistici provenientei dalla grotta preisotrica di s. angelo (ostuni, brindisi) saggi stratigrafici 1953. atti spelaion, martina franca, 139-147. cassoli p.f., tagliacozzo a. (2001) la fauna della grotta s. angelo di ostuni. atti della società per la preistoria e protostoria della regione friulivenezia giulia, 12, 87-92. conti n., petronio c., salari l. (2010) the late pleistocene equids from “tana delle iene” (ceglie messapica, brindisi, southern italy). bollettino della società paleontologica italiana, 49(2), 227-236. conti n., coppola d., petronio c., petrucci m., sardella r., salari l. (2012) la fauna del pleistocene superiore di tana delle iene (ceglie messapica, brindisi, italia meridionale). bollettino del museo civico di storia naturale di verona, 36, 63-76. coppola d. (2012) il riparo di agnano nel paleolitico superiore: la sepoltura di ostuni 1 ed i suoi simboli. terra. università di roma tor vergata, roma, pp. 368. corridi c. (1987) faune pleistoceniche del salento 2. 17 mammal fauna from cava spagnulo la fauna di fondo cattiè, maglie, lecce. i quaderni del museo comunale di paleontologia di maglie, 3, 5-65. de giuli c. (1983) le faune pleistoceniche del salento 1. la fauna di san sidero 3. i quaderni del museo comunale di paleontologia di maglie, 1, 45-79. di stefano g., petronio c., sardella r., savelloni v., squazzini e. (1992) nuove segnalazioni di brecce ossifere nella costa fra castro marina e otranto (lecce). il quaternario, 5(1), 3-10. di stefano g., petronio c., sardella r. (1994) il significato biocronologico e paleoecologico di alcuni taxa di mammiferi del plio-pleistocene dell’italia centrale. studi geologici camerti, 459-467. driesch von den a. (1976) a guide to the measurement of animal bones from archaeological sites: as developed by the institut für palaeoanatomie, domestikationsforschung und geschichte der tiermedizin of the university of munich. peabody museum bullettin, 1, 1-137. fischer von waldheim g. (1817) adversaria zoologica. mémoires de la société impériale des naturalistes moscou, 5, 357-472. gatta m., sinopoli g., giardini m., giaccio b., hajdas i., pandolfi l., bailey g., spikins p.,rolfo m., sadori l. (2016) pollen from late pleistocene hyena (crocuta crocuta spelaea) coprolites: an interdisciplinary approach from two italian sites. review of palaeobotany and palynology, 233, 56-66. giaccio b., coppola d. (2000) note preliminari sul contesto stratigrafico e paleoecologico del sito “tana delle iene” (ceglie messapica, brindisi, se italia). il quaternario, 13(1/2), 5-20. giaccio b., isaia r., fedele f.g., di canzio e., hoffecker j., ronchitelli a., sinitsyn a., anikovich m., lisitsyn s.n., popov v.v. (2008) the campanian ignimbrite and codola tephra layers: two temporal/stratigraphic markers for the early upper palaeolithic in southern italy and eastern europe. journal of volcanology and geothermal research, 177(1), 208-226. gliozzi e., abbazzi l., argenti a., azzaroli a., caloi l., capasso barbato l., di stefano g., esu d., ficcarelli g., girotti o., kotsakis t., masini f., mazza p., mezzabotta c., palombo m.r., petronio c., rook l., sala b., sardella r., zanalda e., torre d. (1997) biochronology of selected mammals. molluscs and ostracodes from the middle pliocene to the late pleistocene in italy. the state of the art. rivisita italiana di paleontologia e stratigrafia, 103(3), 369-388. gray j.e. (1821) on the natural arrangement on vertebrose animal. london medical repository record, 15, 296-310. guiscardi c. (1873) di una grotta con ossami nella provincial di bari. atti della regia accademia delle scienze fisiche e matematiche, napoli, 8, 1-13. goldfuss a. (1820) handbuch der zoologie. johann leonard schrag, nürnberg, pp. 510. iurino d.a., fico r., petrucci m., sardella r. (2013) a pathological late pleistocene canid from san sidero (italy): implications for social and feeding behaviour. naturwissenschaften, 100(3), 235-243. iurino d.a. (2014) body size reduction and tooth agenesis in late pleistocene meles meles (carnivora, mammalia) from ingarano (southern italy). rivista italiana di paleontologia e stratigrafia (research in paleontology and stratigraphy), 120(1), 109-118. linnaeus c. (1758) systema naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. tomus i. laurentius salvius, stockholm. lilljeborg w. (1873) sveriges och norges ryggradsdjur (vol. 2). w. schultz, 551-1088. malviglia c. (1955) ossami fossili trovati nel grotta delle striare (otranto). natura, 46(2), 92-95. masini f., sala b., ambrosetti p., azzaroli a., ficcarelli g., kotsakis t., rook l., torre d. (1991) mammalian faunas of selected villafranchian and galerian localities. in inqua seqs, subcomission for european quaternary stratigraphy, cromer symposium. mazza p., varola a. (1999) revision of the middle pleistocene rhinoceros remains from contrada monticelli (castellana, bari, southern italy). il quaternario, 12(1), 99-104. mecozzi b., iurino d.a., berte d.f., sardella r. (2017) canis mosbachensis (canidae, mammalia) from the middle pleistocene of contrada monticelli (putignano, apulia, southern italy). bollettino della società paleontologica italiana, 56(1), 71-78. mecozzi b., bartolini lucenti s. (2018) the late pleistocene canis lupus (canidae, mammalia) from avetrana (apulia, italy): reappraisal and new insights on the european glacial wolves. italian journal of geosciences, 137, 138-150. minieri f., petronio c., sardella r., scarano m.r. (1993) le faune a mammiferi del pleistocene superiore dell’italia peninsulare. 1° convegno di archeozoologia, rovigo, 75-87. owen r. (1848) description of teeth and portions of jaws of two extinct anthracotherioid quadrupeds (hyopotamus vectianus and hyop. bovinus) discovered by the marchioness of hastings in the eocene deposits on the nw coast of the isle of wight: with an attempt to develope cuvier's idea of the classification of pachyderms by the number of their toes. quarterly journal of the geological society of london, 4, 103-141. pallas p.s. (1775) spicilegia zoologica: quibus novae imprimis et obscurae animalium species iconibus, descriptionibus atque commentariis illustrantur. gottlieb august lange, berolini, 1(1), 1-44. palma di cesnola a. (1991) la campagna 1991 a grotta paglicci. atti del xiii convegno nazionale di preistoria, protostoria e storia della daunia. san severo, 22-24 novembre 1991. pandolfi l., petronio c., salari l. (2013) catastrophic death assemblages from the late pleistocene of italy: the case of avetrana karst filling (taranto, southern italy). rivista italiana di paleontologia e stratigrafia (research in paleontology and stratigraphy), 119(1), 109-124. 18 mecozzi b. et al. petronio c., sardella r. (1998) remarks on the stratigraphy and biochronology of the late pleistocene deposit of ingarano (apulia, southern italy). rivista italiana di paleontologia e stratigrafia, 104(2), 287-294. petronio c., billia e., capasso barbato l., di stefano g., mussi m., parry s. j., sardella r, voltaggio m. (1996) the late pleistocene fauna from ingarano (gargano, italy): biochronological, palaeoecological, paleoethnological and geochronological implications. bollettino della società paleontologica italiana, 34, 333-340. petronio c., di canzio d.e., salari l. (2007) the late pleistocene and holocene mammals in italy: new biochronological and paleoenvironmental data. palaeontographica abteilung a, 279, 147-157. petronio c., bellardini f., arzarello m., bedetti c., bellucci l., cipullo a., di stefano g., pandolfi l., pavia m., petrucci m., sardella r., salari l. (2008) the deposit of the late pleistocene from avetrana (taranto, southern italy): biochronology and palaeoecology. il quaternario, 21(2), 409-422. petrucci m., giardini m., sadori l. (2005) analisi pollinica di coproliti di iena macchiata (crocuta crocuta erxleben) dell'ultimo glaciale della puglia. informatore botanico italiano, 37(1), 932-933. renault-miskovsky j., baills h., marquer l., coppola d. (2011) environnement vegetal et paléoclimatologies des pouilles au paléolithique supérieur. palynologie du gravettian et de l’épigravettien de la grotte de santa maria d’agnano (ostuni, brindisi, italie). bullettin du musée d’anthropologie préhistorique de monaco, 51, 75-86. renault-miskovsky j., baills h., marquer l., coppola d. (2015) santa maria di agnano (ostuni, brindisi, italie). préhistoire et palynologie, paléoclimatologie et paléoenvironnement. rivista di scienze preistoriche, 65, 5-28. rustioni m., mazza p., abbazzi l., delfino m., rook l., petrucci s., vianello f. (1994) the würmian fauna from sternatia (lecce, apulia, italy). bollettino della società paleontologica italiana, 33(2), 279288. rustioni m., ferretti m. p., mazza p., pavia m., varola a. (2003) the vertebrate fauna from cardamone (apulia, southern italy): an example of mediterranean mammoth fauna. deinsea, 9(1), 395-404. sala b., masini f., ficcarelli g., rook l., torre d. (1992) mammal dispersal events in the middle and late pleistocene of italy and western europe. courier forschungsinstitut senckenberg, 153, 59-68. sala b., masini f. (2007) late pliocene and pleistocene small mammal chronology in the italian peninsula. quaternary international, 160, 4-16. sansalone g., bertè d.f., maiorino l., pandolfi l. (2015) evolutionary trends and stasis in carnassial teeth of european pleistocene wolf canis lupus (mammalia, canidae). quaternary science reviews, 110, 36-48. sardella r., bedetti c., bellucci l., conti n., coppola d., di canzio e., pavia m., petronio c., petrucci m., salari l. (2005) the late pleistocene vertebrate fauna from avetrana (taranto, apulia, southern italy): preliminary report. geo. alp, 2, 25-29. sardella r., bertè d., iurino d.a., cherin m., tagliacozzo a. (2014) the wolf from grotta romanelli (apulia, italy) and its implications in the evolutionary history of canis lupus in the late pleistocene of southern italy. quaternary international, 328, 179-195. sardella r., mazzini i., giustini f., mecozzi b., brilli m., iurino d. a., lembo g., massussi m., muttillo b., sigari d., tucci s., voltaggio m. (2018) grotta romanelli (southern italy, apulia): legacies and issues in excavating a key site for the pleistocene of the mediterranean. rivista italiana di paleontologia e stratigrafia (research in paleontology and stratigraphy), 124(2), 247-264. sarti l., boscato p., lo monaco m. (1998) il musteriano finale di grotta del cavallo nel salento: studio preliminare. origini, 22, 45-109. sarti l., boscato p., martini f., spagnoletti a.p. (2002). il musteriano di grotta del cavallo-strati h e i: studio preliminare. rivista di scienze preistoriche, 52(21), 45-109. simpon g.g. (1941) large pleistocene felines of north america. american museum novitates, 1136, 127. simpon g.g., roe a., lwontin r.c. (1960) quantitative zoology. harcourt brace, new york, pp. 440. steinmann g., döderlein l. (1890) elemente der paläontologie. engelmann, pp. 850. tramonti a. (1974) grottaglie, cava del piano deposito preistorico (f 202, i se, grottaglie 4032’58 n, 459’22’’ e). notiziario topografico salentino, 2, 134-136. trouessart e.l. (1880) on a new very small shrew from mayotte, crocidura (pachyura) coquerelii, pollen and van dam, ms. notes from the leyden museum, 2(2), 85-89. ungar p.s. (2010) mammal teeth: origin, evolution, and diversity. johns hopkins university press, baltimore, pp. 303. zanchetta g., giaccio b., bini m., sarti, l. (2018) tephrostratigraphy of grotta del cavallo, southern italy: insights on the chronology of middle to upper palaeolithic transition in the mediterranean. quaternary science reviews, 182, 65-77. 19 ms. received: february 1, 2018 final text received: may 14, 2018 mammal fauna from cava spagnulo 20 untitled il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 late holocene relative sea level change in malta sara biolchi1,2, timothy gambin3, ritienne abela4, fabrizio antonioli5, stefano furlani6,1, marco anzidei7 & stefano devoto2 1 dipartimento di geoscienze, università degli studi di trieste, italy 2 dipartimento di scienze della terra, università degli studi di modena e reggio emilia, modena, italy 3 university of malta/aurora trust, malta 4 university of malta, malta 5 enea, casaccia, roma, italy 6 dipartimento di geografia “g. morandini”, università degli studi di padova, italy 7 ingv, roma, italy corresponding author: s. furlani <sfurlani73@gmail.com> abstract: biolchi s. et al., late-holocene relative sea level ch’ange in malta. (it issn 0349-3356, 2011) a multidisciplinary approach has been used to evaluate the late-holocene relative sea-level change in malta. published data, together with new coastal underwater observations of archaeological sites have been compared with predicted sea level curves, to evaluate the relative sea level change. riassunto: biolchi s. et al ., variazioni tardo-oloceniche del livello marino a malta. (it issn 0349-3356, 2011) le variazioni tardo-oloceniche di livello marino sull’isola di malta sono state studiate attraverso un approccio multidisciplinare. la comparazione tra una serie di nuove misure sulle quota di alcune strutture archeologiche costiere sommerse, l’utilizzo di dati pubblicati e le curve ottenute dai modelli hanno permesso di delineare una prima indicazione sulle variazioni di livello marino dell’isola. key words: sea level change, late-holocene, geoarchaeology, malta parole chiave: variazioni di livello marino, tardo-olocene, geoarcheologia, malta late-holocene relative sea level changes have been well-detailed along the mediterranean coasts. until now, few archaeological or geomorphological data have been considered to evaluate sea level changes along the maltese coast, although both the geomorphological evolution and the development of coastal settlements could provide useful information on the active tectonics (uplift or downlift, seismicity, etc). we aim at providing new data on coastal archaeological remains collected along the western and southern coast of malta and to discuss the relative late holocene tectonic rates. 1. study area malta lies in the sicily channel, about 200 km south of the convergent segment of the europeafrica plate boundary. the sicily channel has been affected, during neogene–quaternary (finetti, 1984; dart et al., 1993), by continental rifting which produced extensive structures, such as the pantelleria, malta and linosa tectonic depressions, controlled by nw-directed subvertical normal faults (fig. 1). the most active period of extension on both fault trends occurred during the plio-quaternary (jongsma et al. 1985). the maltese graben system is characterized by two intersecting fault trends. to the sw of malta, the 100 km wide nw-se-trending pantelleria rift occur (reuther & eisbacher 1985). it is dissected by the two important ene-wsw trending graben: the north gozo and north malta graben. the graben transects mesozoic to tertiary shallow marine and pelagic limestones. it has also been responsible for the major tectonic and geomorphological development of the maltese islands (illies, 1981). the stratigraphic succession, characterized by shallow marine deposits, spanning in time from upper oligocene to upper miocene (various authors, 1993). the studied sites are located on globigerina limestone. 2. data we studied two archaeological structures, the first at st. george’s bay, at birzebbugia and the latter next to manoel island, at the valletta harbour (fig. 1). 1) the birzebbugia archaeological site provides remains of activities related to the coastal zone, during the bronze age (zammit, 1928; abela, 1999). it provides two types of archaeological remains. the first type are bronze age pits (35002900 bp, fig. 2), located close to the shoreline on 20 22 21 the globigerina limestone platform, which are partially submerged. they were dated using pottery discovered in an archaeological site close to the coast. they were probably used as heats, as a red coat has been surveyed at the edge of the structures. the altitude of the lowest pit is -0.9 m and it represents the upper limit of sea level in the studied period, considering that they had to stay surely always above the sea. the second type are prehistoric cart tracks, completely submerged (abela, 1999). 2) at manoel island, submerged tanks, maybe roman in age, with an altitude ranging between 1.20 m at the bottom and -0.7 m at the top of the walls. they could be used to produce garum or purpura. 3. discussion on the island, archeological structures directly carved on rocky outcrops are very common, because of their high rock erodibility. the soft globigerina limestones outcrops along the southern and eastern sector of the island. archeological remains have been surveyed just along these coasts. anyway, observations carried out along the maltese coast recorded the presence of a number of nineteenth-century (victorian-age) swimming pools, usually architecturally welldefined. their position and their relative bad conservation can easily cause misunderstandings, insomuch as they can be confused with coastal archaeological remains. considering the submerged roman age tanks, despite their complex attribution, concerning both the age and the function, they seem to suggest that sea level was some tens of centimeters lower than the structure. on the contrary, the altitude of the lowest bronze age pit represents the upper limit of sea level in the studied period, considering that they had to stay surely always above the sea. no presence of mis 5.5 deposits have been surveyed, due (1) to the exposition of the island, that prevents the conservation of rocks and deposits, or (2) to the kind of bedrock easy to dismantle slightly submerged position of the tyrrenian deposits which deleted them. even if, at the moment, few data are available and better interpretations are required, the comparison of surveyed data and lambeck & purcell (2005) predicted curve, no late-holocene vertical displacement seem to be occurred. fig. 1 geodynamical setting of the maltese islands (modified after galea, 2007) and location of the two archaeological sites. inquadramento geodinamico dell’arcipelago maltese (modificato da galea, 2007) e ubicazione dei siti archeologici studiati. late-holocene relative sea level ch’ange in malta ... 22 ms. received: testo ricevuto il references abela r. (1999) – relative sea level change: a coastal vulnerability assessment of malta. unpublished thesis, university of malta, 217. dart c.j., bosence w.j. & mcclay k.r. (1993) stratigraphy and structure of the maltese graben system. j. geol. soc. lond. 150, 1153–1166. finetti i.r., (1984) geophysical study of the sicily channel rift zone. boll. geofis. teor. appl. 26, 3–28. galea p. (2007) seismic history of the maltese islands and considerations on seismic risk, annals of geophysics, 50 (6), 725-740. illies j.h. (1981) graben formation: the maltese islands – a case study, tectonophysics, 73, 151-168. jongsma d., woodside j.m., king g.c.p. & van hinte j.e. (1987) the medina wrench: a key to the kinematics of the central and eastern mediterranean over the past 5 ma, earth planet. sci. lett., 82, 87-106. lambeck k. & purcell a. (2005) – sea-level change in the mediterranean sea since the lgm: model predictions for tectonically stable areas. quaternary science reviews, 24, 1969-1988. reuther c.d. & eisbacher g.h. (1985) pantelleria rift crustal extension in a convergent intraplate setting, int. j. earth sci., 74 (3), 585-597. various authors (1993) geological map of the maltese islands. sheet 1 – malta – scale 1:25000, oil exploration directorate, office of the prime minister, malta. zammit t. (1928) prehistoric cart-tracks in malta, antiquity, 2 (5), 18-25. fig. 2, the pits at st. george’s bay, birzebbugia, s malta. le strutture archeologiche presso st. george’s bay, a birzebbugia, nella parte meridionale di malta.  s. biolchi et al. january 15, 2011 15 gennaio 2011 amq32(2) 151-165 trotta et al.pub climate variability through mis 20-mis 19 in core kc01b, ionian basin (central mediterranean sea) samanta trotta, maria marino, patrizia maiorano, angela girone dipartimento di scienze della terra e geoambientali, università degli studi di bari aldo moro, bari, italy. corresponding author: s. trotta <samantatrotta.93@gmail.com> abstract: high resolution quantitative analyses have been carried out on coccolithophore assemblages at the ionian sea core kc01b in the time interval crossing the deglaciation between marine isotope stages 20 and 19 (termination ix, in lower-middle pleistocene). principal component analysis emphasizes the temperature as the first environmental parameter affecting coccolithophore assemblages that reach a higher number of coccoliths per gram of sediment during the interglacial. patterns of key taxa indicate the occurrence of a terminal stadial phase in the late mis 20 when the presence of cold, turbid and low salinity surface waters in the ionian sea are highlighted by prominent peaks of coccolithus pelagicus ssp. pelagicus, gephyrocapsa muellerae >3 m, and increased abundances of syracosphaera spp., helicosphaera carteri, rhabdosphaera spp. enhanced reworked coccoliths and lithic elements are recorded in the samples during this phase, and they represent an useful tool to monitoring the amount of detrital input supply during low sea-level and major erosion process on land. short-term warm and cool events through tix are evidenced by the fluctuations of all these proxies anticipating the interglacial onset. the latter is marked by distinct surface water conditions suggesting the occurrence of an interval correlated to a sapropelic layer, and specifically to i-cycle 74. the comparison of these short-lived events with the climate pattern recently observed in the nearby montalbano jonico succession points to a shared ionian sea climatic and oceanographic pattern through tix and allows to sustain a similar climate evolution recorded during the last deglaciation. keywords: coccolithophores; termination ix; sapropel i-cycle 74; lower-middle pleistocene.   available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 32 (2), 2019, 151 165 1. introduction marine isotope stage (mis) 19 (lower-middle pleistocene) has been recently studied in high temporal resolution through different proxies since it represents the best analogous of holocene and the finest past interglacial to forecast future climate trend (e.g. tzedakis et al., 2012; ferretti et al., 2015; giaccio et al., 2015; sánchez-goñi et al., 2016; nomade et al., 2019; regattieri et al., 2019). minor attention has been devoted to deglaciation mis 20-mis 19 (termination ix, tix) except for some studies (emanuele et al., 2015; marino et al., 2015; maiorano et al., 2016a; nomade et al., 2019). in particular, maiorano et al. (2016a), based on multiproxy analyses carried out in the montalbano jonico section (south italy), recognized a high frequency climate variability that has been associated to the similar climate pattern during last deglaciation (termination i, ti). these authors indicated the occurrence of surface water features connected to heinrich-like (h-like) phase during late mis 20 followed by warm bølling-allerød-like (b/alike) and cool younger dryas-like (y/dlike) events before the sapropelic layer (red sapropel, i-cycle 74, 784 ka) (langereis et al., 1997; lourens, 2004) and the onset of mis 19. aim of this study is to provide additional information on mis 20-19 transition in ionian basin utilizing as proxy, the phytoplanktonic group of the coccolithophores. coccolithophores, are calcareous algae (chromista), dominant marine calcifying phytoplankton and sediment component, able to record changes in the sea surface water properties, such as temperature, turbidity, nutrients, and salinity (e.g. mcintyre & bè, 1967; flores et al., 2000; baumann et al., 2004; thierstein & young, 2004; ziveri et al., 2004; giraudeau & beaufort, 2007). the studied sediments are from the core kc01b, recovered in the ionian sea and it has been already considered as a reference record for the last 1.1 ma (castradori, 1993; sanvoisin et al., 1993; langereis et al., 1997; rossignol-strick et al., 1998; lourens, 2004; konijnendijk et al., 2014). this record has been also used for mediterranean sapropel stratigraphy and astronomical time scale (lourens, 2004). in this study, high https://doi.org/10.26382/amq.2019.10 152 trotta s. et al. resolution quantitative analyses (0.4-0.7 ka) on coccolithophore assemblages and principal component analysis (pca) have been performed in order to recognize orbital-suborbital and millennial scale paleoenvironmental variations. a comparison with climate records from montalbano jonico and north atlantic ocean has been also performed to give insight on the knowledge of climate pattern in the ionian basin across tix and its relationship with north hemisphere ice-sheet dynamics during lower-middle pleistocene. 2. oceanographic setting the mediterranean is a semi-enclosed marginal sea that is characterized by an anti-estuarine circulation system with the atlantic ocean through the strait of gibraltar (bormans et al., 1986; rohling et al., 1998; rohling & de rijk, 1999). the atlantic water (aw) enters the mediterranean sea and travels eastward as modified atlantic water (maw) which is restricted to a surface layer about 200 m thick (fig. 1a). as it spreads eastward throughout the basin, it becomes saltier due to continued evaporation (wüst, 1961; malanotte-rizzoli & hecht, 1988). maw influences the eastern basin with the atlantic-ionian stream jet-like current (ais) (malanotte-rizzoli et al., 1997) and mid-ionian jet (mij) through the ionian sea and levantine basin, respectively (fig. 1b). the ais, after having crossed the strait of sicily, forms a meander that continues to the north, towards the ionian, which is influenced by its most superficial part of the maw; then the ais branches off and a part goes southward, creating an anticyclonic area (ionian anticyclone-ia), the other branch extends to the north and returns to the south, passing through the ionian sea (fig. 1b) (malanotte-rizzoli et al., 1997). recently, the upper-layer circulation in the ionian sea has been associated with the deep thermohaline circulation through the bimodal oscillating system: the ionian upper-layer circulation reverses from cyclonic to anticyclonic and vice versa on decadal time scale affecting the biological productivity in the northern ionian and southern adriatic sea (civitarese et al., 2010; gačić et al., 2010). mediterranean sea is characterized by oligotrophic conditions (béthoux, 1979; sarmiento et al., 1988). during winter there are mesotrophic conditions because of vertical mixing or coastal upwelling which bring the nutrients to the photic zone, instead, during the summer, there are oligotrophic conditions due to the thermal stratification and deepening of summer thermocline (krom et al., 1992, 1993; crispi et al., 1999; allen et al., 2002; siokou-frangou et al., 2010). 3. material and methods 3.1. the studied core the piston core kc01b has been recovered in the eastern mediterranean, in the ionian sea, on the calabrian ridge (pisano plateau, 36°15,25' n, 17°44,34' e) at a depth of 3643 meters below sea level (fig. 1a and b). core kc01b was recovered during cruise md69 of the french r/n marion dufresne (june-july 1991), within the european union scientific program mast (marflux and palaeoflux), with the aim to reconstruct biogeochemical cycles in the mediterranean and eastern north atlantic. kc01b is one of the longest piston cores ever recovered in the eastern mediterranean, as it extends for a length of 37.04 meters. the recovery of the sediment is characterized by continuous sedimentation and good preservation, except for the uppermost part of the core (321 cm), which has been damaged due to the coring operations (sanvoisin et al., 1993). the lithology consists of hemipelagic marls (carbonate content of about 30-50 %), with intercalation of sapropels and the presence of several thin tephra layers and few thin turbidite levels (castradori, 1993; sanvoisin et al., 1993; langereis et al., 1997; rossignol-strick et al., 1998; lourens, 2004). in the studied interval (from 28.86 m to 29.52 m), an oxidized sapropel (“ghost sapropel”, emeis et al., 2000) has been firstly recognized in the hemipelagic marl at the depth of 29 m by langereis et al. fig. 1 a) location of the studied core kc01b in the ionian sea and other sites in mediterranean area (mj: montalbano jonico) and atlantic ocean (odp 980, iodp u1385) discussed in the text. b) detail of surface water circulation in the ionian sea in agreement with malanotte-rizzoli et al. (1997). aw= atlantic water; maw=modified atlantic water; ais= atlantic ionian stream; ia= ionian anticyclone; mij= mid ionian jet. 153 climate variability through mis 20-19 in core kc01b, ionian basin (central mediterranean sea) (1997) based on its rock-magnetic and geochemical properties and referred as i-cycle 74 (785 ka, langereis et al., 1997). then, a revised meter depth of the core has indicated the sapropelic level occurrence at 28.87 m (784 ka, lourens, 2004; 785 ka, konijnendijk et al., 2014). in kc01b, sixty-seven samples, with a spacing of 1 cm, were analysed in the hemipelagic marls of section 8, between 13 and 81 cm (from 28.86 m to 29.53 m), crossing the late mis 20-early mis 19 interval, in agreement with the isotope stratigraphy of rossignol-strick et al. (1998) and lourens (2004). 3.2. coccolithophore analysis slides for coccolithophore analysis have been prepared according to flores & sierro (1997). this technique provides to obtain slides with coccoliths distributed homogeneously and to estimate coccolith abundance per gram of sediment (n) according to the formula of flores & sierro (1997): n = n * r2 * v *r2 * g-1* v-1 where n is the number of coccoliths per gram of dry sediment, n is the number of coccoliths counted in a random scanned area, r the radius of the petri disk, v the volume of water added to the dry sediment in the vials, r the radius of the visual field used in the counting, g the dry sediment weigh, v the volume of mixture withdrawn with the micropipette. quantitative analyses have been performed using a polarized light microscope at 1000× magnification and abundances have been determined by counting about 500 coccoliths. this method allows to have 99% probability that a taxon is detected if its real abundance in the assemblage is at least 1% (crow et al., 1960). during this count, the reworked taxa (cretaceous to neogene in age) have been counted separately together with the lithic or mineral elements >10 m to estimate the amount of inorganic input in each sample. because most of the assemblage consists of coccoliths of the genus gephyrocapsa, the less abundant taxa, but of important ecological and paleoenvironmental significance, are not detectable in a significant percentage during the first counting. for this reason, an additional count of the less abundant species has been extended on total 30 fields of view. the quantitative abundances of coccolithophores have been expressed both as percentages and number of coccoliths per gram of sediment (n). coccolithophore taxonomy follows jordan et al. (2004) and young et al. (2003) for living coccolithophores, and maiorano et al. (2013) for the gephyrocapsid group. discosphaera tubifera, calciosolenia sp., oolithotus fragilis, oolithotus antillarum, umbilicosphaera sibogae and umbilicosphaera foliosa have been grouped as warm water taxa (wwt) because they are known as indicative of warm and oligotrophic waters being abundant in tropical-subtropical waters (winter et al., 1994; young, 1994; ziveri et al., 1995; 2004; andruleit et al., 2003; baumann et al., 2004; boeckel & baumann, 2004; saavedra-pellitero et al., 2010). helicosphaera pavimentum and calcidiscus small (<5 m) have been also included in the wwt. helicosphaera pavimentum is described as a warm taxon found in tropical and sub-tropical areas of the pacific ocean and atlantic ocean (okada & mcintyre, 1977; steinmetz, 1991) and included in the wwt by marino et al. (2018) in the middle pleistocene record of mediterranean sea. calcidiscus small, although rare in the study site, has been found in equatorial atlantic waters of the southern hemisphere, suggesting a preference for warmer waters (boeckel & baumann, 2008). in order to estimate the preservation of the assemblages, the dissolution index (di) has been calculated accordingly to dittert et al. (1999) modified by amore et al. (2012) as: small gephyrocapsa/(small gephyrocapsa + calcidiscus leptoporus).this index, which compares breakable (small gephyrocapsa) versus dissolution resistant placoliths (calcidiscus), includes gephyrocapsids smaller than 3 m and with open central area, thus excluding the more calcified coccoliths of small g. caribbeanica. finally, pca has been performed on the percentage abundance of the assemblages using the software past (paleontology statistic) (hammer et al., 2001) with the aim to clarify the relationship between coccolithophore distribution and paleoenvironmental variables. the component with maximum variance (pc1) has been discussed and interpreted in terms of paleoclimate changes through the investigated interval. 4. results 4.1. updated chronological frame the astronomically tuned age model proposed by langereis et al. (1997) at the core kc01b was slightly revised by rossignol-strick et al. (1998) (fig. 2) who presented the first oxygen isotope record tuned to the ice volume model of imbrie & imbrie (1980). later, lourens (2004) improved the chronological frame of planktonic oxygen isotope record of rossignol-strick et al. (1998) based on sapropel stratigraphy using the highresolution color reflectance correlation with the ocean drilling project (odp) site 964. recently, a highresolution benthic isotope stratigraphy (nomade et al., 2019) has been provided in the interval from late mis 20 to mis 18 inception at the montalbano jonico on land section (ionian basin) located not far from the kc01b core (fig. 1a). the isotope curve of nomade et al. (2019), together with the low resolution benthic 18o (ciaranfi et al., 2010) and in agreement with the pattern of the lr04 (lisiecki & raymo, 2005), highlights a younger age of mis 20-mis 19 transition (tix) with respect to that described by the lourens’s 18o chronology at the core kc01b (fig. 2). we thus propose an updated chronology of the isotope record in the studied interval based on a visual comparison of the 18o pattern with the lr04 stacked record. we did not rely on the high resolution 18o by nomade et al. (2019) at the montalbano jonico section since the latter covers a shorter time interval. four tie-points have been selected from the lr04 record (see colored arrows in fig. 2): the beginning of mis 20 at 812 ka, the onset of mis 20-19 deglaciation at 794 ka, the lightest value of 18o in mis 19c at 780 ka, and the mis 18 inception at 756 ka. these tie-points are critical times in the substage delineation of railsback et al. (2015, and references therein) representing respectively mis 20d, 20a, full 19c, and 18e inception (fig. 2). these events are also recognizable in the higher resolution 18o of the montalbano jonico section (fig. 2). the sedimentation rate at the studied core varies from 1.4 cm/ky to 2.4 cm/ky, while the temporal resolution of analysis varies from 0.7 ka to 0.4 ka accordingly to the updated age model. 4.2 coccolithophore assemblages the coccolithophore assemblages show good preservation. thirty-five taxa, at the level of genus, species and subspecies have been recognized and selected taxa are shown in plate 1. the di, shown in fig. 3, records values higher than 0.9 indicating low dissolution. lower values have been recorded in late mis 20. the n of the total assemblage ranges from a minimum of 24x108 coccoliths per gram of sediment (n°/gr) to a maximum of 410x108 n°/gr (fig. 3). the lowest number of coccoliths has been recorded during glacial stage, while it increases during interglacial phase (fig. 3). the figure 3 shows the taxonomic composition of the assemblage. the genus gephyrocapsa represents the main component (over than 80%) (fig. 3). small gephyrocapsa spp. (from 17% to 58%) includes gephyrocapsids <3 μm with open central area. gephyrocapsa spp. >3 m with values from 19% to 55%, includes gephyrocapsa margereli 154 fig. 2 tuning of kc01b 18o record with the benthic stacked lr04 (lisiecki & raymo, 2005). colored arrows and ages on lr04 are the tie-points used for the new age model at the core kc01b and they are also shown on the high resolution montalbano jonico 18o records of cassidulina carinata and melonis barleeanum (nomade et al., 2019). the low resolution of benthic 18o c. carinata at montalbano jonico section is also drawn (ciaranfi et al., 2010). on the right the mean summer insolation (jas, 65°n w/m², laskar et al., 2004). mis: marine isotope stage; 18e-21a: substages according to railsback et al. (2015); i-cycle: insolation cycle (lourens, 2004). the shaded area represents the studied interval . trotta s. et al. 155 plate 1 selected coccolithophore photographs captured by the polarizing optical microscope. np: parallel nicol, xn crossed nicol. scale bar represents 5 m. 1-2: rhabdosphaera clavigera. kc01b, 28.86 m. 1: xn-2: np; 3-4: coccolithus pelagicus subsp. pelagicus. kc01b, 29.52 m. 3: xn-4: np; 5: gephyrocapsa margereli-g. muellerae. kc01b, 29.21 m. 5: xn. 6: gephyrocapsa caribbeanica. kc01b, 29.21 m. 6: xn; 7-8: helicosphaera carteri. kc01b, 29.52 m. 7: xn-8: np; 9-10: oolithotus antillarum. kc01b, 29.51 m. 9: xn-10: np; 11-12: calcidiscus leptoporus subsp. leptoporus. kc01b, 29.52 m. 11: xn-12: np; 13: syracosphaera pulchra. kc01b, 29.21 m. 13: xn; 14: florisphaera profunda. kc01b, 29.21 m. 14: xn; 15-16: umbilicosphaera sibogae. kc01b, 29.51 m. 15: xn-16: np. climate variability through mis 20-19 in core kc01b, ionian basin (central mediterranean sea) -g. muellerae, and very rare and scattered g. oceanica, g. omega and g. muellerae. g. caribbeanica >3 m reaches a percentage of 32% with a minimum of 1.6%, while g. caribbeanica <3 m has values between 1.5% and 30%. taxa with lower abundances include: helicosphaera spp. (h. carteri, h. hyalina, h. wallichii), with a maximum of 3%; syracosphaera spp. (s. pulchra, s. histrica) with values up to 3.2%; rhabdosphaera spp. (r. clavigera var. styilifera, r. clavigera) with percentages lower than 2.4%; coccolithus spp. (c. pelagicus ssp. pelagicus, c. pelagicus ssp. braarudii, c. pelagicus ssp. azorinus) that not reaches percentage higher than 1.3 %; florisphaera profunda that ranges between 0.5 % and 8.5%. calcidiscus spp. (c. leptoporus 5-8 μm, c. quadriperforatus 8-10 m) and pseudoemiliania lacunosa have percentage generally lower than 1%, rarely up to 3% (fig. 3). the wwt group has low abundance with a maximum of 2.6%. “other taxa”, having percentage from 0.2% to 5.6%, include taxa with rare and scattered occurrences: ceratolithus spp., reticulofenestra sp. >3 m, coronosphaera sp., pontosphaera sp., scyphosphaera sp., u. hulburtiana, holococcoliths. 5. discussion 5.1. statistical analysis the pca indicates that the first and the second components have percentage variance of 33% and 13%, respectively. only the first component (pc1) was considered since it has a higher value and then a greater control of coccolithophore assemblage. the most 156 tab. 1 loadings of coccolithophore taxa on the first component (pc1) at core kc01b. the most relevant component loadings are indicated in red bold (positive loading) and black bold (negative loading). percentage of variance is 33%. fig. 3 from left to right, plotted versus age: δ18o record at the study core kc01b (rossignol-strick et al., 1998); δ18o record related to the studied interval at the study core kc01b (rossignol-strick et al., 1998), with updated age model (this study); coccolithophore dissolution index (di); total coccolithophore abundance expressed as number of coccoliths per gram of sediment (n*10⁸); factor 1 (pc1); cumulative abundance of taxa percentages. trotta s. et al. relevant negative loadings in coccolithophore assemblage are for the species indicative of warm sea surface waters such as taxa included in wwt group and g. caribbeanica (> and <3 μm), a typical taxon of warm and oligotrophic surface waters (bollmann, 1997) (tab. 1). pc1 mainly loads with positive score the subarctic species c. pelagicus ssp. pelagicus, a traditional cold-water indicator (baumann et al., 2000), g. margereli-g. muellerae and g. muellerae >3 m, syracosphaera spp., r. clavigera, r. clavigera var. stylifera and h. carteri. g. margereli-g. muellerae is considered an indicator of cool/cold surface water condition; in particular, g. muellerae has been found in colder surface waters (weaver & pujol, 1988; samtleben & bickert, 1990; samtleben et al., 1995; bollman, 1997; okada & wells, 1997; giraudeau et al., 2010; amore et al., 2012) and g. margereli in transitional assemblages of oceanic area (bollman, 1997). the positive loadings of syracosphaera spp., r. clavigera, r. clavigera var. stylifera and h. carteri may be associated to fresher and turbid surface water condition as recorded in mediterranean sea during pleistocene colder phases (colmenero-hidalgo et al., 2004; maiorano et al. 2013, 2016b; bazzicalupo et al., 2018; marino et al., 2018). pca results make possible to interpret the pc1 as sea surface water temperature with associated condition of oligotrophy during interglacial phase or low salinity and turbidity during colder episodes. the changes in coccolithophore assemblages observed at the study core, combined with the pattern of the pc1 (fig. 4), show that environmental modifications occurred at the glacial-interglacial and millennial scale, making it possible to highlight the climate variability starting from late mis 20 to early mis 19c. 5.2. mis 20 and terminal stadial event during the glacial phase mis 20, cold seasurface conditions prevailed in the ionian sea, as shown by the increase of cold c. pelagicus ssp. pelagicus and cool-cold g. margereli-g. muellerae, and by the low abundance of wwt (fig. 4g-f-e), in agreement with their ecological preferences respectively for lower and higher surface water temperatures. the high values of pc1, interpreted as temperature, during this time, may support cold conditions (fig. 4, tab. 1). the concomitant abundance of h. carteri, syracosphaera spp., rhabdosphaera spp. (fig. 4h-i-j), although fluctuating, may be an indication of variable condition of low salinity and 157 fig. 4 comparison of the δ18o record at the core kc01b in ionian basin (a), versus time, with the mean summer insolation (jas, 65°n w/m²) (b), factor 1 (pc1) (c), coccolithophore taxa (d-k; n), reworked calcareous nannofossils (l), lithic elements > 10 m (m). mis: marine isotope stage. full area in plotted taxa: percentage abundance; grey line: number of coccoliths per gram of sediment (n*10⁸). the transition between mis 20 and mis 19 is represented with soften colours on the left. climate variability through mis 20-19 in core kc01b, ionian basin (central mediterranean sea) turbid sea surface waters (maiorano et al., 2016a, b) in the ionian basin, possibly as a result of intermittent run off from land. this is supported by the concurrent high abundances of reworked coccoliths and lithic elements >10 m (fig. 4l-m) suggesting increased erosion as it may be expected during the glacial low sea level, as already highlighted by maiorano et al. (2016a, b). during the late mis 20, between 797.6 ka and 794.1 ka, a colder climate episode may be inferred due to the significant increase of c. pelagicus ssp. pelagicus and g. muellerae >3 m (fig. 4g-k), and the maximum value in the pc1 (lower temperature). the prominent increase of the percentage abundances of h. carteri, syracosphaera spp., and rhabdosphaera spp. (fig. 4h-i-j), is a signal of enhanced turbidity and low salinity in stratified surface waters. the major values in the lithic elements >10 m during this phase (fig. 4m) point to enhanced low 158 sea level that promoted on land erosional process and higher detrital input toward the basin. local influence of low salinity waters from surrounding apennines mountain ice melting through strengthened fluvial payload may have played a significant role, as already conceived by maiorano et al. (2016a, and references therein). however, such environmental frame may be associated to a terminal stadial phase of glacial mis 20 (hodell et al., 2015) characterized by the arrival of north atlantic meltwater at the ionian sea. such interpretation finds agreement with the similar oceanographic outline already hypothesized in the montalbano jonico section (fig. 1) during late mis 20 based on multi-proxy data (maiorano et al., 2016a) (fig. 5c), and it can be correlated to the occurrence of ice rafted detritus (ird) in the north atlantic odp sites 980 (wright & flower, 2002) (fig. 5a) and 983 (kleiven et al., 2011) as a signal of fig. 5 time comparison between climate phases plotted on the δ18o at the core kc01b in ionian basin (f) and percentage of ird at odp -980 site in north atlantic (a), alkenone derived sea surface temperature (sst) at site u1385 located in north atlantic (b), oxygen and carbon isotopic curves (c, d, nomade et al., 2019) and climate phases (colored bands in c, maiorano et al., 2016a) at montalbano jonico section, and mean summer insolation curve (jas, 65°n w/m², laskar et al., 2004) (e). mis: marine isotope stage. h-like: heinrich-like event; ba-like: bølling-allerød-like event; yd-like: younger-dryas-like event; s: sapropel. the transition between mis 20 and mis 19 at the studied core kc01b is represented with soften colours. trotta s. et al. north hemisphere ice-sheet collapse. maiorano et al. (2016a) proposed a “h-like” (heinrich-like) event for the colder phase of late mis 20. cold meltwaters of north atlantic origin have been also inferred in mediterranean basin during pleistocene glacial periods based on different proxies, including peaks of c. pelagicus ssp. pelagicus and neogloboquadrina pachyderma left coiling (colmenero-hidalgo et al., 2004; sierro et al., 2005; girone et al., 2013; capotondi et al., 2016; marino et al., 2018). therefore, the peak in abundance of c. pelagicus ssp. pelagicus at the core kc01b in the late mis 20 may be an additional evidence that the ionian sea recorded the north atlantic climate via oceanographic connection. 5.3. short-term climate phases toward mis 19 onset above the terminal stadial of mis 20, a warm climate episode is recorded from 794.1 ka to 791.3 ka, marked by the reduction in the abundance of g. margereli-g. muellerae, c. pelagicus spp. pelagicus, as well as by a slight but distinct increase of g. caribbeanica and wwt (fig. 4f-g, d-e). all these taxa record an opposite pattern in the following phase, between 791.3 ka and 789.3 ka, suggesting a restored short-term cool spell, in agreement with the pattern of pc1 (fig. 4c). helicosphaera carteri, syracosphaera spp., rhabdosphaera spp., reworked taxa and lithic elements >10 m (fig. 4i-j-k-l-m) also mimic decrease and increase during these two climate episodes, respectively, highlighting variation in the surface water features, specifically related to turbidity and salinity in addition to temperature. the warm event was therefore characterized by slightly higher temperature and less turbid surface water possibly linked to the first climate amelioration that followed the terminal stadial of mis 20 toward the interglacial onset. pc1 has in fact lower values (higher temperature) in this phase (fig. 4c). this warming phase may have favoured melting of local mountain ices promoting detrital input supply to the basin and the following cooling of surface waters that in turn allowed cold species (c. pelagicus ssp. pelagicus, g. margerelig. muellerae) to thrive together with taxa able to proliferate in turbid waters (syracosphaera spp., rhabdosphaera spp.). the occurrence of these two short events appears in agreement with the climate pattern known during last deglaciation (ti) which displayed the warm bølling-allerød and cold youngerdryas events (mangerud et al., 1974) and correspond to the greenland interstadial (gi)-1 and greenland stadial (gs)-1 (björck et al., 1988) just before the holocene inception. these data support the suggestions of maiorano et al. (2016a) who referred the short-term warm and cool events following h-like in the montalbano jonico section to “b/a-like” and “y/d-like” (fig. 5c); moreover, they sustain the high climate variability recognized during glacial terminations in previous quaternary studies (martrat et al., 2007; siddal et al., 2010; barker et al., 2011). 5.4. sapropel-like during interglacial mis 19 the beginning of the interglacial mis 19c is marked by the decrease of cold taxa and increasing trend of g. caribbeanica and wwt (fig. 4d-e). the pc1 records lower values that remain quite stable for the following studied interval, except for few small fluctuations (fig. 4c). the establishment of temperate surface waters at the base of mis 19c (between 789.3 ka and 786.8 ka) is accompanied by surface water stratification. this is supported by the peak in abundance of f. profunda (centred at 789.1 ka and at 29.19 m) (fig. 4n), that is an indicator of deep nutricline and low surface water productivity (molfino & mcintyre, 1990a, b). its abundance is accompanied by increase of syracosphaera spp. (fig. 4i) as a signal of variations in salinity and nutrient content (flores et al., 1997), quickly followed by the highest n of h. carteri (centred at 787.7 ka and 29.17 m) (fig. 4h), suggesting turbid and less salty waters (ziveri et al., 1995; negri et al., 1999; negri & giunta, 2001; colmenero-hidalgo et al., 2004; maiorano et al., 2016a). these patterns might be interpreted as linked to oceanographic condition typical of sapropel formation when increased humid condition over the mediterranean area, linked to strengthened north africa monsoon, promoted huge fresh water influx that caused surface water stratification and higher amount of suspended detritus. it is interesting to note that the “red interval” indicated at the studied core by langereis et al. (1997) and tuned to “i-cycle 74” was not identified at 29.17 m, like in this study, but at 29 m where instead we did not find any signal of oceanographic conditions related to sapropel formation based on coccolithophore assemblage. accordingly, our interpretation is further supported by good correlations with analogous oceanographic conditions recorded in the near montalbano jonico section at the beginning of mis 19c based on both biological proxies (including peak of f. profunda and turbid water tolerant taxa) (maiorano et al., 2016a) and a prominent minimum in the benthic 13c (nomade et al., 2019) at 783.31 ka (fig. 5d). all these parameters suggest the occurrence of stratification of the water column and preservation of organic matter in conditions of low oxygenation at the sea bottom, that in turn correspond to the red interval i-cycle 74. 5.5. correlation of ionian sites with north atlantic cores and paleoceanographic implications the paleoclimatic and paleoceanographic frame reconstructed at the core kc01b through mis 20-mis 19 deglaciation seems to be comparable to that described at montalbano jonico, in fact, similar climatic events during tix occur in both sites with the identical progression and rather similar duration (fig. 5c-f). therefore, the same terminology proposed in maiorano et al. (2016a), that is h-like, b/a-like, y/d-like, has been utilized. the different ages of these events in core kc01b with respect to those recorded in montalbano jonico section are in a chronological uncertainty of about 3 ka. the age model at the studied core would thus require a further refinement that cannot be provided without a higher resolution oxygen isotope data-set, which in turn may benefit from the sapropel event as a valuable chronological tie-point at 784 ka (lourens, 2004), and in agreement with the age assignment of 159 climate variability through mis 20-19 in core kc01b, ionian basin (central mediterranean sea) nomade et al. (2019). waiting for a more robust updated chronology, that is not a matter of this study, we would emphasize that the montalbano jonico and kc01b results document a shared pattern of climate variability just before mis 19 inception, that is well comparable to ti climate event occurrence (asioli et al., 2001; di stefano & incarbona, 2004; geraga et al., 2010; siani et al., 2010, 2013; maiorano et al., 2016a). an oceanographic connection between north atlantic and ionian basin during h-like event seems possible based on coccolithophore assemblages (increase of subarctic taxa), even if the atmospheric influence from northern latitudes via variable north westerly winds on the warming/cooling, stratification/mixing of central mediterranean waters may not be excluded (poulos et al., 1997; rohling et al., 1998, 2002; casford et al., 2001; melki et al., 2009). oceanic circulation and atmospheric processes related to ice-sheet dynamics in north atlantic have been in fact invoked by nomade et al. (2019) as a possible engine of millennial scale climate variation at montalbano jonico section during mis 19b-a, and by regattieri et al. (2019) to explain the high frequency climate changes displayed in the sulmona lacustrine sediments during mis 19. in this frame, h-like event in the ionian basin would correspond to an interval of atlantic meridional overturning circulation (amoc) slowdown/shutdown (mcmanus et al., 1999), when iceberg discharge released ird in north atlantic (site 980, fig. 5a) producing cold-low salinity surface meltwater in the mid latitude of iberian margin as well (site u1385, fig. 5b). following, enhanced atlantic cold-water influx through gibraltar strait (sierro et al., 2005) could have reached the mediterranean sea where the arcticsubarctic coccolithophore key taxa (c. pelagicus ssp. pelagicus, g. muellerae >3 m) did proliferate. this is in agreement with the arrival of atlantic meltwaters at central mediterranean already documented by sprovieri et al. (2012) based on lightening signature in planktonic  18o during heinrich events of the last 70 ka. during this phase, cold and arid atmospheric conditions linked to reduced evaporation and moisture-rich air mass advection towards the mediterranean region (tzedakis et al., 2004; sierro et al., 2005; margari et al., 2009; sinopoli et al., 2018), may have enhanced lower surface water temperature and favoured cold taxa. in support of this climate reconstruction, dry condition on land during the termination ix h-like event has been documented at montalbano jonico section (bertini et al., 2015; marino et al., 2015; maiorano et al., 2016a) and correlated to a prominent ird peak at the odp 980 and a significant increase of aeolian dust in the eastern mediterranean (larrasoaña et al., 2003). accordingly, semi-desert vegetation establishment has been indicated in the u1385 core, west of iberian margin (sánchez-goñi et al., 2016). such combined climate signals seem to indicate that oceanic-atmospheric connection may be inferred between central mediterranean and northern atlantic climate, linked to oceanographic circulation and icesheet dynamics. 6. concluding remarks the high-resolution analysis on coccolithophore assemblages carried out on the core kc01b has provided the recognition of climate changes at orbital and millennial scale through late mis 20 and early mis 19. the pca has indicated the temperature as the first environmental parameter that influences the distribution of taxa and the abundance of coccolithophores. the pattern of factor 1 highlights glacial-interglacial phases and millennial scale climate events associated to a heinrich-like event in late mis 20, followed by b/a-like, and y/d-like events before the beginning of major interglacial warming. the colder surface water conditions during h-like phase have been evidenced by prominent abundance of c. pelagicus ssp. pelagicus and g. margereli-g. muellerae >3 m. lower salinity and higher turbidity accompanied this phase due to increase of syracosphaera spp., h. carteri, rhabdosphaera spp., reworked coccoliths and lithic elements >10 m, suggesting enhanced erosion process on surrounding land during prominent low sea level. the quantitative pattern of lithic elements revealed to be a useful tool in monitoring the inorganic input amount toward the location of the studied core. a change has been recorded just above the event, based on the same key coccolithophore taxa and detrital input proxies, pointing to a 2.8 ka warming event characterized by less turbid and normal saline waters, followed by a cool spell event (duration 2 ka) with a re-establishment of turbidity and low salinity conditions. the h-like phase in both the studied core and the montalbano jonico section (maiorano et al., 2016a) and its correlation with north atlantic sst at the u1385 and ird at odp-980 cores seem to document the arrival of north atlantic cold meltwaters at the ionian sea based on coccolithophore assemblages. however, north westerly winds and atmospheric process related to north hemisphere ice-sheet dynamics during more arid climate as documented in the italian peninsula (e.g. bertini et al., 2015) and at wider scale (sánchez-goñi et al., 2016) may have affected surface water features. in the earlier phase of interglacial mis 19 an oceanographic surface water condition typical of sapropelic deposition has been inferred based on the abundance peak of f. profunda and h. carteri that sustain the occurrence of turbid, less salty and stratified surface waters in relation to increased north africa monsoon, close to insolation maximum i-cycle 74. the correlation of our data with those provided in the close montalbano jonico site underlines a good correspondence of the events recorded from late mis 20 to mis 19 onset, in term of progression and duration. the older ages of the climate events and sapropel at the studied site with respect to the chronology of the same events at montalbano jonico, highlight the need of a slight updating of the age model at the core kc01b. the overall data suggest that the ionian sea records a strong signature of high frequency climate variability across tix like that occurred during last deglaciation, that could be relevant in future climate prospecting. 160 trotta s. et al. acknowledgments the authors thank miriam cobianchi (university of pavia), barbara balestra (university of santa cruz, california) and an anonymous reviewer for their helpful revisions which improved the first version of the manuscript. the editors adele bertini and andrea sposato are acknowledged for their useful suggestions, and gert de lange (university of utrecht) for providing samples of core kc01b. this research was funded by fondi di ateneo 2018 university of bari assigned to patrizia maiorano. references allen j.i., somerfield p.j., siddorn j. (2002) primary and bacterial production in the mediterranean sea: a modelling study. journal of geophysical research, 33-34, 473-495. amore f.o., flores j.a., voelker a.h.l., lebreiro s.m., palumbo e., sierro f.j. (2012) a middle pleistocene northeast atlantic coccolithophore record: paleoclimatology and paleoproductivity aspects. marine micropaleontology, 90-91, 44-59. andruleit h., stäger, s., rogalla u., cepek p. (2003) living coccolithophores in the northern arabian sea: ecological tolerances and environmental control. marine micropaleontology, 49, 157-181. asioli a., trincardi f., lowe j.j., ariztegui d., langone l., oldfield f. (2001) submillennial scale climatic oscillations in the central adriatic during the late glacial: palaeoceanographic implications. quaternary science review, 20, 1201-1221. barker s., knorr g., edwards r.l., rarrenin f., putnam a.e., skinner l.c, wolff e., ziegler m. (2011) 800,000 years of abroupt climate variability. science, 334, 347-351. baumann k.-h., andruleit h., samtleben c. (2000) coccolithophores in the nordic seas: comparison of living communities with surface sediment assemblages. deep sea research ii, 47, 17431772. baumann k.h., freitag t. (2004) pleistocene fluctuations in the northern benguela current system as revealed by coccolith assemblages. marine micropaleontology, 52, 195-215. bazzicalupo p., maiorano p., girone a., marino m., nebout n.c., incarbona a. (2018) highfrequency climate fluctuations over the last deglaciation in the alboran sea, western mediterranean: evidence from calcareous plankton assemblages. palaeogeography, palaeoclimatology, palaeoecology, 506, 226-241. bertini a., toti f., marino m., ciaranfi n. (2015) vegetation and climate across the early-middle pleistocene transition at the montalbano jonico section (southern italy): quaternary international, 383, 7488. doi: 10.1016/j.quaint.2015.01.003. béthoux j.p. (1979) budgets of the mediterranean sea. their dependence on the local climate and on the characteristics of the atlantic waters. oceanologica acta, 2 (2), 157-163. björck s., walker m.j.c., cwynar l.c., johnsen s., knudsen k.l., lowe j.j., wohlfarth b., members, i.n.t.i.m.a.t.e. (1998) an event stratigraphy for the last termination in the north atlantic region based on the greenland ice-core record: a proposal by the intimate group. journal of quaternary. science, 13, 283-292. boeckel b., baumann k.h. (2004) distribution of coccoliths in surface sediments of the southeastern south atlantic ocean: ecology, preservation and carbonate contribution. marine micropaleontology, 51, 301-320. boeckel b., baumann k.-h. (2008) vertical and lateral variations in coccolithophore community structure across the subtropical frontal zone in the south atlantic ocean. marine micropaleontology, 67, 255 -273. bollmann j. (1997) morphology and biogeography of the genus gephyrocapsa coccoliths in holocene sediments. marine micropaleontology, 29, 319350. bormans m., garret c., thompson k.r. (1986) seasonal variability of the surface inflow through the strait of gibraltar. oceanologica acta, 9 (4), 403414. capotondi l., girone a., lirer f., bergami c., verducci m., vallefuoco m., afferri a., ferraro l., pelosi n., de lange g.j. (2016) central mediterranean mid -pleistocene paleoclimatic variability and its association with global climate. palaeogeography, palaeoclimatology, palaeoecology, 442, 72-83. casford j.s.l., abu-zied r., rohling e.j., cooke s., boessenkool k.p., brinkhuis h., de vries c., wefe g., geraga m., papatheodorou g., croudace i., thomson i., lykousis v. (2001) mediterranean climate variability during the holocene. mediterranean marine science, 2/1, 45-55. castradori d. (1993) calcareous nannofossils and the origin of eastern mediterranean sapropel. paleoceanography, 8 (4), 459-471. ciaranfi n., lirer f., lirer l., lourens l.j., maiorano p., marino m., petrosino p., sprovieri m., stefanelli s., brilli m., girone a., joannin s., pelosi n., vallefuoco m. (2010) integrated stratigraphy and astronomical tuning of the lower-middle pleistocene montalbano jonico land section (southern italy). quaternary international, 210, 109-120. civitarese g., gačić m., lipizer m., eusebi borzelli g.l. (2010) on the impact of the bimodal oscillating system (bios) on the biogeochemistry and biology of the adriatic and ionian seas (eastern mediterranean). biogeosciences, 7, 3987-3997. colmenero-hidalgo e., flores j.a., sierro j., barcena m.a., lowemark l., schonfeld j., grimalt j.o. (2004) ocean surface water response to shortterm climate changes revealed by coccolithophores from the gulf of cadiz (ne atlantic) and alboran sea (w mediterranean). palaeogeography, palaeoclimatology, palaeoecology, 205, 317336. crispi g., crise a., mauri e. (1999) seasonal threedimensional study of the nitrogen cycle in the med 161 climate variability through mis 20-19 in core kc01b, ionian basin (central mediterranean sea) iterranean sea part ii verification of the energy constrained trophic model. journal of marine systems, 20, 357-380. crow e.l., davis f.a., maxfield m.w. (1960) statistics manual. dover, new york. 320 pp. di stefano e., incarbona a. (2004) high resolution paleoenvironmental reconstruction of the odp963d hole (sicily channel) during the last deglaciation, based on calcareous nannofossils. marine micropaleontology, 52, 241-254. dittert n., baumann k.h., bickert r., henrich r., huber r., kinkel h., meggers h. (1999) carbonate dissolution in the deep-sea: methods, quantification and paleoceanographic application. in: fischer g., wefer g. (eds.), use of proxies in paleoceanography: examples from the south atlantic. springer, berlin, 255-284. emanuele d., ferretti p., palumbo e., amore f.o. (2015) sea-surface dynamics and palaeoenvironmental changes in the north atlantic ocean (iodp site u1313) during marine isotope stage 19 inferred from coccolithophore assemblages. palaeogeography, palaeoclimatology, palaeoecology, 430, 104-117. emeis k., sakamoto t., wehausen r., brumsack h.j. (2000) the sapropel record of the eastern mediterranean sea results of ocean drilling program leg 160. palaeogeography, palaeoclimatology, palaeoecology, 158, 371-395. ferretti p., crowhurst s.j., naafs b.d.a., barbante c. (2015) the marine isotope stage 19 in the midlatitude north atlantic ocean: astronomical signature and intra-interglacial variability. quaternary science reviews, 108, 95-110. flores j.a., sierro f.j. (1997) revised technique for calculation of calcareous nannofossil accumulation rates. micropaleontology, 43, 321-324. flores j.-a., bárcena m.a., sierro f.j. (2000) oceansurface and wind dynamics in the atlantic ocean off northwest africa during the last 140,000 years. palaeogeography, palaeoclimatology, palaeoecology, 161, 459-478. gačić m., borzelli g.l.e., civitarese g., cardin v., yari s. (2010) can internal processes sustain reversals of the ocean upper circulation? the ionian sea examples. geophysical research letters, 37 (9), 1-5. geraga m., ioakim c., lykousis v., tsaila monopolis s., mylona g. (2010) the high resolution palaeoclimatic and palaeoceanographic history of the last 24,000 years in the central aegean sea, greece. palaeogeography, palaeoclimatolgy, palaeoecolgy, 287, 101-115. giaccio b., regattieri e., zanchetta g., nomade s., renne p.r., sprain c.j., drysdale r.n., tzedakis p.c., messina p., scardia g., sposato a., bassinot f. (2015) duration and dynamics of the best orbital analogue to the present interglacial. geology, 43 (7), 603-606. giraudeau j., beaufort l. (2007) coccolithophores from extant population to fossil assemblages, in: developments in marine geology, proxies in late cenozoic paleoceanography edited by: hillairemarcel c., de vernal a., elsevier, amsterdam, 409 -439. giraudeau j., grelaud m., solignac s., andrews j.t., moros m., jansen e. (2010) millennial-scale variability in atlantic water advection to the nordic seas derived from holocene coccolith concentration records. quaternary science reviews, 29, 1276-1287. girone a., capotondi l., ciaranfi n., di leo p., lirer f., maiorano p., marino m., pelosi n., pulice i. (2013) paleoenvironmental change at the lower pleistocene montalbano jonico section (southern italy): global versus regional signals. palaeogeography, palaeoclimatology, palaeoecology, 371, 62-79. hammer ø., harper d.a.t., ryan p.d. (2001) past: paleontological statistics software package for education and data analysis. palaeontology electron, 4 (1), 9. hodell d., lourens l., crowhurst s., konijnendijk t., tjallingii r., jimenez-espejo f., skinner l., tzedakis p.c., shackleton site project members. (2015) a reference time scale for site u1385 (shackleton site) on the sw iberian margin. global and planetary change, 133, 48-64. imbrie j., imbrie j.z. (1980) modelling the climatic response to orbital variations. science, 207, 943953. jordan r.w., cros l., young j.r. (2004) a revised classification scheme for living haptophytes. micropaleontology, 50 (supplement 1), 55-79. kleiven h., hall i.r., mccave i.n., knorr g., jansen e. (2011) north atlantic coupled deep-water flow and climate variability in the middle pleistocene: geology, 39 (4), 343-346. konijnendijk t.y.m., ziegler m., lourens l.j. (2014) chronological constraints on pleistocene sapropel depositions from high-resolution geochemical records of odp sites 967 and 968: newsletters on stratigraphy, 47 (3), 263-282. krom m.d., kress m.d. n., neori a., gordon l. i. (1992) nutrient dynamics and new production in a warmcore eddy from the e mediterranean. deep sea research part a. oceanographic research papers, 39, 467-480. krom m.d., brenner s., kress n., neori a., gordon l. i. (1993) nutrient distributions during an annual cycle across a warm core eddy from the eastern mediterranean sea. deep sea research part i: oceanographic research papers, 40, 4, 805-825. langereis c.g., dekkers m.j., de lange g.j., paterne m., van santvoort p.j.m. (1997) magnetostratigraphy and astronomical calibration of the last 1.1 myr from an eastern mediterranean piston core and dating of short events in the brunhes. geophysical journal international, 129, 75-94. larrasoaña j., roberts a. p., rohling e. j., winklhofer m., wehausen r. (2003) three million years of monsoon variability over the northern sahara. climate dynamics, 21, 689-698. laskar j., robutel p., joutel f., gastineau m., correia a.c.m., levrard b. (2004) a long term numerical 162 trotta s. et al. solution for the insolation quantities of the earth. astronomy & astrophysics, 428, 261-285. doi: 10.1051/0004-6361:20041335. lisiecki l. e., raymo m.e. (2005) a pliocenepleistocene stack of 57 globally distributed benthic  18o records. paleoceanography, 20, pa1003. lourens l. j. (2004) revised tuning of ocean drilling program site 964 and kc01b (medi-terranean) and implications for the 18o, tephra, calcareous nannofossil, and geomagnetic reversal chronologies of the past 1.1 myr. paleoceanography, 19, pa3010. maiorano p., marino m., tarantino f., de lange g.j. (2013) paleoenvironmental conditions at kc01b (ionian sea) through mis 13 and 9: evidence from calcareous nannofossil assemblagesquaternary international, 28, 97-111. maiorano p., bertini a., capolongo d., eramo g., gallicchio s., girone a., pinto d., toti f., ventruti g., marino m. (2016a) climate signatures through the marine isotope stage 19 in the montalbano jonico section (southern italy): a land-sea perspective. palaeogeography, palaeoclimatology, palaeoecology, 461, 341-361. maiorano p., girone a., marino m., kucera m., pelosi n. (2016b) calcareous plankton response to midbrunhes climate variability in the western mediterranean (odp site 975). palaeogeography, palaeoclimatology, palaeoecology, 459, 229-248. malanotte-rizzoli p., manca b.b., ribera d’alcalà m., theocharis a. (1997) a synthesis of the ionian sea hydrography circulation and water mass pathways during poem-phase i. progress in oceanography, 39, 153-204. malanotte-rizzoli p., hecht a. (1988) large-scale properties of the eastern mediterranean: a review. oceanologica acta, 11 (4), 323-335. mangerud j., andersen s.t., berglund b.e., donner j.j. (1974) quaternary stratigraphy of norden, a proposal for terminology and classification. boreas, 4, 109-128. margari v., gibbard p.l., bryant c.l., tzedakis p.c. (2009) character of vegetational and environmental changes in southern europe during the last glacial period; evidence from lesvos island, greece. quaternary science reviews, 28 (13-14), 1317-1339. marino m., bertini a., ciaranfi n., aiello g., barra d., gallicchio s., girone a., la perna r., lirer f., maiorano p., petrosino p., toti f. (2015) paleoenvironmental and climatostratigraphic insights for marine isotope stage 19 (pleistocene) at the montalbano jonico section, south italy: quaternary international, 383, 104-115. doi: 10.1016/j.quaint.2015.01.043. marino m., girone a., maiorano p., di renzo r., piscitelli a., flores j.a. (2018) calcareous plankton and the mid-brunhes climate variability in the alboran sea (odp site 977). palaeogeography, palaeoclimatology, palaeoecology, 508, 91-106. martrat b., grimalt j.o., shackleton n.j., de abreu l., hutterli m.a., stocker t.f. (2007) four climate cycles of recurring deep and surface water destabilizations on the iberian margin. science, 317 (5837), 502-507. mcintyre a., bé a.h.w. (1967) modern coccolithophores of the atlantic ocean i. placolith and cyrtoliths. deep sea research, 14, 561-597. mcmanus j.f., oppo d.w., cullen j.l. (1999) a 0.5million-year record of millennial scale climate variability in the north atlantic. science, 283 (5404), 971-975. melki t., kallel n., jorissen f.j., guichard f., dennielou b., berné s., labeyrie l., fontugne m. (2009) abrupt climate change, sea surface salinity and paleoproductivity in the western mediterranean sea (gulf of lion) during the last 28 kyr. palaeogeography, palaeoclimatology, palaeoecology, 279, 96-11. molfino b., mcintyre a. (1990a) processional forcing of nutricline dynamics in the equatorial atlantic. science, 249, 766-769. molfino b., mcintyre a. (1990b) nutricline variation in the equatorial atlantic coincident with the younger dryas. paleoceanography, 5, 997-1008. negri a., capotondi l., keller j. (1999) calcareous nannofossils, planktonic foraminifera and oxygen isotopes in the late quaternary sapropels of the ionian sea. marine geology, 157, 89-103. negri a., giunta s. (2001) calcareous nannofossil paleoecology in the sapropel s1 of the eastern of ionian sea: paleoceanographic implication. palaeogeography, palaeoclimatology, palaeoecology, 169, 101-112. nomade s., bassinot f., marino m., simon q., dewilde f., maiorano p., esguder g., blamart d., girone a., scao v., pereira a., toti f., bertini a., combourieu-nebout n., peral m., bourles d., petrosino p., gallicchio s., ciaranfi n. (2019) highresolution foraminifer stable isotope record of mis 19 at montalbano jonico, southern italy: a window into mediterranean climatic variability during a loweccentricity interglacial. quaternary science reviews, 205, 106-125. okada h., mcintyre a. (1977) modern coccolithophores of the pacific and north atlantic oceans. micropaleontology, 23 (1), 1-56. okada h., wells p. (1997) late quaternary nannofossil indicators of climate change in two deep-sea cores associated with the leeuwin current off western australia. palaeogeography, palaeoclimatology, palaeoecology, 131, 413-432. poulos s.e., drakopoulos p.g., collins m.b. (1997) seasonal variability in sea surface oceanographic conditions in the aegean sea (eastern mediterranean): an overview. journal of marine systems, 13, 225-244. railsback l.c., gibbard p.l., heas m.j., voarintsoa n.r.g., tucanne s. (2015) an optimized scheme of lettered marine isotope substages for the last 1.0 million years, and the climatostratigraphic nature of isotope stages and substages. quaternary science review, 111, 94-106. regattieri e., giaccio b., mannella g., zanchetta g., 163 climate variability through mis 20-19 in core kc01b, ionian basin (central mediterranean sea) nomade s., tognarelli a., perchiazzi n., vogel hendrik boschi c., drysdale r. n., wagner b., gemelli m., tzedakis p. (2019) frequency and dynamics of millennial-scale variability during marine isotope stage 19: insights from the sulmona basin (central italy). quaternary science reviews, 214, 28-43. rohling e. j., hayes a., de rijk s., kroon d., zachariasse w. j., eisma d. (1998) abrupt cold spells in the northwest mediterranean. paleoceanography, 13, 316-322. rohling e. j., de rijk s. (1999) the holocene climate optimum and last glacial maximum in the mediterranean: the marine oxygen isotope record, marine geology, 153, 57-75. rohling e.j., cane t.r., cooke s., sprovieri m., bouloubassi i., emeis k.c., schiebel r., kroon d., jorissen f.j., lorre a., kemp a.e.s. (2002) african monsoon variability during the previous interglacial maximum. earth and planetary science letters, 202, 61-75. rossignol-strick m., paterne m., bassinot f. c., emeis k.c., de lange g. j. (1998) an unusual midpleistocene monsoon period over africa and asia. nature, 392, 269-272. saavedra-pellitero m., flores j.a., baumann k.h., sierro f.j. (2010) coccolith distribution patterns in surface sediments of equatorial and southeastern pacific ocean geobios, 43, 131-149. samtleben c., bickert t. (1990) coccoliths in sediment traps from the norwegian sea. marine micropaleontology, 16, 39-64. samtleben c., schäfer p., andruleit h., baumann a., baumann k.h., kohly a., matthiessen j., schröder -ritzrau a. (1995) plankton in the norwegiangreenland sea: from living communities to sediment assemblages an actualistic approach. geologische rundschau, 84, 108-136. sánchez-goñi m.f., rodrigues t., hodell d.a., polanco -martínez j.m., alonso-garcía m., hernándezalmeida i., desprat s., ferretti p. (2016) tropically-driven climate shifts in southwestern europe during mis 19, a low eccentricity interglacial. earth and planetary science letters, 448, 81-93. sanvoisin r., d’onofrio s., lucchi r., violanti d., castrodori d. (1993) 1ma paleoclimatic record from the eastern mediterranean-marflux project: first results of a micropaleontological and sedimentological investigation of a long piston core from the calabrian ridge. il quaternario, 6 (2), 169-188. sarmiento j.l., herbert t., toggweiler j.r. (1988) mediterranean nutrient balance and episodes of anoxia. global biogeochemical cycles, 2, 427444. siani g., paterne m., colin c. (2010) late glacial to holocene planktic foraminifera bioevents and climatic record in the south adriatic sea. journal of quaternary science, 25, 808-821. siani g., magny m., paterne m., debret m., fontugne m. (2013) paleohydrology reconstruction and holocene climate variability in the south adriatic sea: climate of the past, 9, 499-515. doi: 10.5194/cp-9-499-2013. siddal m., rohling e.g., blunier t., spahni r. (2010) patterns of millennial variability over the last 500 ka. climate of the past discussions, 6, 1934. sierro f.j., hodell d.a., curtis j.h., flores j.a., reguera i., colmenero-hidalgo e., bárcena m.a., grimalt j.o., cacho i., frigola j., canals m. (2005) impact of iceberg melting on mediterranean thermohaline circulation during heinrich events. paleoceanography, 20, pa2019. sinopoli g., masi a., regattieri e., wagner b., francke a., peyron o., sadori l. (2018) palynology of the last interglacial complex at lake ohrid: palaeoenvironmental and palaeoclimatic inferences. quaternary science review, 180, 177-192. siokou-frangou i., christaki u., mazzocchi m.g., montresor m., ribera d’alcalà m., vaqué d., zingone a. (2010) plankton in the open mediterranean sea: a review. biogeosciences, 7, 15431586. sprovieri m., di stefano e., incarbona a., salvagio manta d., pelosi n., ribera d'alcalà m., sprovieri r. (2012) centennialto millennial-scale climate oscillations in the central-eastern mediterranean sea between 20,000 and 70,000 years ago: evidence from a high-resolution geochemical and micropaleontological record. quaternary science reviews, 46, 126-135. steinmetz j.c. (1991) calcareous nannoplankton biocoenosis: sediment trap studies in the equatorial atlantic, central pacific, and panama basin. in: honjo s., (ed.), ocean biocoenosis series, vol. 1. woods hole oceanographic institution, 1-85. thierstein h., young j.r. (2004) coccolithophores from molecular process to global impact. eds. amsterdam, springer. tzedakis p.c., frogley m.r., lawson i.t., preece r.c., cacho i., de abreu l. (2004) ecological thresholds and patterns of millennial-scale climate variability: the response of vegetation in greece during the last glacial period. geology, 32, 109-112. tzedakis, p.c., channell j.e.t., hodell d.a., kleiven h.f., skinner l.c. (2012) determining the natural length of the current interglacial. nature geoscience, 5, 138-141. weaver p.p.e., pujol c. (1988) history of the last deglaciation in the alboran sea (western mediterranean) and adjacent north atlantic as revealed by coccolith floras. palaeogeography, palaeoclimatology, palaeoecology, 64, 35-42. winter a., siesser w. (1994) coccolithophores. cambridge university press, new edition 242. cambridge university press london. wright a.k., flower b.p. (2002) surface and deep ocean circulation in subpolar north atlantic during the mid-pleistocene revolution. paleoceanography, 17. doi: 1029/2002pa000782. wüst g. (1961) on the vertical circulation of the mediterranean sea, journal of geophysical research, 66, 3261-3271. 164 trotta s. et al. young r. j. (1994) the function of coccoliths. in winter a., siesser w.g. (eds.), coccolithophores. cambridge university press, london 63-82. young j.r., geisen m., cros l., kleijne a., probert i., ostergaard j.b. (2003) a guide to extant coccolithophore taxonomy. journal of nannoplankton research, special issue 1, 1-132. ziveri p., thunell r.c., rio d. (1995) export production of coccolithophores in an upwelling region: results from san pedro basin, southern california borderlands. marine micropaleontology, 24, 335358. ziveri p., baumann k.h., boeckel b., bollmann j., young j. (2004) biogeography of selected holocene coccoliths in the atlantic ocean. in: thierstein h.r., young j. r. (eds), coccolithophores: from molecular processes to global impact. springer, berlin 403-428. 165 ms. received: june 18, 2019 final text received: july 9, 2019 climate variability through mis 20-19 in core kc01b, ionian basin (central mediterranean sea) 166 amq abs bartolinilucenti rook saccom 169-172.pub available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 169 172 the fossil record of the genus canis (canidae, carnivora, mammalia) from the upper valdarno: a critical revision in the frame of the early and middle pleistocene canids of eurasia saverio bartolini lucenti1,2, lorenzo rook2 1 dottorato di ricerca in scienze della terra, università di pisa, pisa, italy 2 dipartimento di scienze della terra, università degli studi di firenze, firenze, italy corresponding author: s. bartolini lucenti <saverio.bartolini@dst.unipi.it> abstract: the outstanding fossil record of the upper valdarno basin is renown since the xv century. its early pleistocene sample of canids, characterized by the large sized lycaon falconeri and the medium-sized canis arnensis and canis etruscus, has laid the basis for the study of the evolution of the genus canis in western eurasia. in recent years, several discoveries tend to modify our conception on this subject, e.g. the lineage that leads to modern wolves or the inter/intraspecific variability of fossil species, but the record of uv basin remains one of the most extensive and important of its age. keywords: upper valdarno, pleistocene, canidae, taxonomy, evolution 1. introduction in the international panorama of continental quaternary sites, the upper valdarno basin is historically renowned from the renaissance for its outstanding record of large mammals (rook et al., 2013), and since the 18th century naturalists and early palaeontologists, above all g. cuvier (cuvier, 1812; 1821-1824), have studied the mammals recovered from this basin (cioppi & dominici, 2010). for the scholars who study the family canidae, the significance of this basin emerged by the end of the 19th and the beginning of the 20th century (forsyth major, 1877; del campana, 1913) with the description of the medium-sized canis arnensis del campana, 1913 and the large lycaon falconeri (forsyth major, 1877). these two species, together with canis etruscus forsyth major, 1877 also recovered from the other tuscan locality of olivola, represented the earliest species of the genus to be described in western eurasia. the faunal assemblage of these localities suggested a correlation to the beginning of the calabrian (i.e., at that time, the plio-pleistocene boundary) (azzaroli, 1977), as confirmed by some magnetostratigraphic calibrations (e.g. napoleone et al., 2003). the appearance of canis etruscus came to be known as the “wolf event” (azzaroli, 1983; azzaroli et al., 1988; rook & torre, 1996). other findings, e.g. those of coste san giacomo (2.1 ma, bellucci et al., 2012) and vialette (disputed 3 ma, lacombat et al., 2008), have shown the diachronic state of the arrival of canis taxa in europe (sotnikova & rook, 2010 for further discussion). nevertheless, the record of canis the upper valdarno still has to be regarded with great interest by international researchers for the implication its fossil have. for instance, c. etruscus is generally considered as the ancestor of the lineage that leads to the modern wolf (sotnikova, 2001; brugal & boudadi-maligne, 2011). moreover, several sites across eurasia indicate the occurrence of c. etruscus-like canids (see cherin et al., 2014 and reference therein). on the contrary, c. arnensis seems limited to sites of “tasso fu” faunal components (torre et al., 1992). interestingly, the former argued that this species could be the european representative of a holoarctic coyote-like population, with canis lepophagus as american correspondent. during the early pleistocene the diversity of species of canis is not limited to these two as canis senezensis martin, 1973 was described from senèze (massif central, france; ca. 2 ma) whereas in spain, canis accitanus garrido & arribas, 2008 is reported from fonelas p-1 (guadix basin, granada ca. 1.9-1.7 ma). around 1.5-1.4 the first representatives of canis mosbachensis soergel, 1925 appears in spain and in italy. lastly, from the site of apollonia comes the disputed canis apollonensis koufos & kostopoulos, 1997. this variability of species decreases around the epivillafranchian (ca 1 ma) as only c. mosbachensis remained in western europe (sotnikova & rook, 2010). in asia, the pattern of decrease in diversity is similar. during the early pleistocene several medium to large-sized species were present [canis chihliensis zdansky, 1924 and canis palmidens (teilhard de chardin & piveteau, 1930) from nihewan basin; canis teilhardi qiu et al., 2004, canis longdanensis qiu et al., 2004 and canis brevicephalus qiu et al., 2004 from longdan] but in the middle pleistocene the mediumsized and mesocarnivorous niche of canids was occupied by c. mosbachensis variabilis pei, 1934 (jiangzuo et al., 2018). this short review aims to resume past knowledge in the light of recent discoveries with unpublished material that has significant implications for the phylogeny of this group of carnivora. https://doi.org/10.26382/aiqua.2018.aiquaconference 2. material and methods the material considered for the present research is housed at the museum of natural history of the university of florence. comparative fossil and extant sample studied comes from various european sites (fig. 1) and it is held in different european and north american institution as the montevarchi paleontological museum; la specola zoology section of the museum of natural history of the university of florence; the american museum of natural history (new york); the georgian national museum (tbilisi); the aristotle university of thessaloniki; the hungarian museum of natural history and the geological society of hungary (budapest); earth science department of the université claude bernard lyon-1. furthermore all the relevant literature on fossil canis has been reviewed. the morphometric analyses used in this study include log ratio diagrams (simpson, 1941), box plots, and biplots. those analyses were performed with past ver. 3.14 (hammer, 2016). the measurements where taken to nearest of 0.1 mm following driesch (1976). 3. results the morphometric and morphological comparison of the tuscan material of c. etruscus and that of c. etruscus from dmanisi showed important difference both in dental proportions and, more importantly, in cranial features e.g., the elongation of the skull in rostrocaudal sense; the length of the nasal (fig. 2); the height of the skull; the anteroposterior divergence of the medial wall of the tympanic bullae. the morphology of these characteristics in c. “etruscus” from dmanisi are more similar to the other early pleistocene canid c. mosbachensis as well as to extant and more derived species e.g. c. lupus rather to the coeval c. etruscus or c. arnensis. similar characteristics have been recognized in the sample of gerakarou (greece). although the size is intermediate between c. arnensis and c. etruscus, the greek specimens show the same morphologies that characterize the material of canis sp. from dmanisi. the analyses on several samples taxa from early and middle pleistocene sites across europe such as venta micena, pirro nord, apollonia, petralona, vértesszȍlȍs ii (fig. 1) have revealed a wide range of variability in size but a general morphology shared by all these samples, all referable to c. mosbachensis-like canids. 4. discussion and conclusions the fossils of c. arnensis and c. etruscus of the olivola and tasso fu represent one of the most extensive record of the genus canis of the early quaternary and among the earliest record in western europe. these samples remain pivotal basis for comparison in the attempt to resolve the intricate scenario of early pleistocene canids across eurasia. the morphometric and morphological characteristics found in the georgian canis “etruscus” greatly contrast with the peculiarities of c. etruscus. moreover, the canis from dmanisi presents several cranial affinities to eurasian c. mosbachensis and to other modern wolf-related species, for instance the antero-posteriorly divergent medial walls of the tympanic bullae, as also noticed by sotnikova & rook (2010). relevance of this feature stands in the fact that 170 bartolini lucenti s., rook l. fig. 1 geographic localization of the sites considered in this study. 1, venta micena, spain; 2, cueva victoria, spain; 3, vallparadís estació-cal guardiola, spain; 4, olivola, italy; 5, upper valdarno, italy; 6, pirro nord, italy; 7, gerakarou, apollonia-1, petralona, greece; 8, dmanisi, georgia; 9, vértesszȍlȍs ii, hungary. only some extant species but no fossil taxa present it, with the exception of c. mosbachensis (bartolini lucenti et al., 2017; jianzuo et al., 2018). altogether this evidence leads us to consider this taxon as canis sp. nov. the new information on the dmanisi canis sp. has strong implications on the evolutionary history of the late villafranchian canids, because it changes the widely accepted c. etruscus-c. mosbachensis-c. lupus lineage. although the status of c. mosbachensis is questioned by some authors (for an updated resume see mecozzi et al., 2017), the slight morphological differences found in samples of early to middle pleistocene sites attributed to c. mosbachensis-like canids should definitely be regarded as results of the intraspecific variability. surely, such little variations are not sufficient to erect new species. likewise, it would be misleading to interpret this diversity as part of the variability of the modern c. lupus. in this sense, the ascription of the chinese taxon c. variabilis as a subspecies of c. mosbachensis in jiangzou et al. (2018) offers an interesting solution to the issue. acknowledgements the authors are thankful to all the curator of the institutions visited for granting us access to the collection in order to study the variability of early-middle pleistocene: cioppi e.(igf), rustioni m. (mpm), agnelli p. (mzuf), galkin j., meng j. (amnh), lordkipanidze d., bukhsianidze m. (gnm), koufos g. (aut), gasparik m. (hmnh), robert e. (ucbl), berthet d. (mdc). references azzaroli a. (1977) the villafranchian stage in italy and the plio-pleistocene boundary. giornale di geologia, 41, 61-79. azzaroli a. (1983) quaternary mammals and the endvillafranchian dispersal event a turning point in the history of eurasia. palaeogeography, palaeoecology, palaeoclimatology, 44, 117-139. azzaroli a., de giuli c., ficcarelli g., torre d. (1988) late pliocene to early mid-pleistocene mammals in eurasia: faunal succession and dispersal events. palaeogeography, palaeoecology, palaeoclimatology, 66, 77-100. bartolini lucenti s., alba d.m., rook l., moyà-solà s., madurell-malapeira j. (2017) latest early pleistocene wolf-like canids from the iberian peninsula. quaternary science review, 162, 12-25. bellucci l., mazzini i., scardia g., bruni l., parenti f., segre a.g., naldini e.s., sardella r. (2012) the site of coste san giacomo (early pleistocene, central italy): palaeoenvironmental analysis and biochronological overview. quaternary international, 267, 30-39. doi: 10.1016/j.quaint.2011.04.006 brugal j.p., boudadi-maligne m. (2011) quaternary small to large canids in europe: taxonomic status and biochronological contribution. quaternary international, 243, 171-182. doi: 10.1016/j.quaint.2011.01.046 cherin m., bertè d.f., rook l., sardella r. (2014) redefining canis etruscus (canidae, mammalia): a 171 canis of the upper valdarno: revision in the eurasian framework fig. 2 boxplot resuming the variability of the ratio gnl/tl (greatest nasal length/total length of the cranium) in early pleistocene taxa (as c. etruscus, c. arnensis, c. mosbanchesis, and canis sp. from dmanisi) and in extant species of the genus canis. new look into the evolutionary history of early pleistocene dogs resulting from the outstanding fossil record from pantalla (italy). journal mammalian evolution, 21, 95-110. cioppi e., dominici s. (2010) origin and development of the geological and palaeontological collections. in: monechi s. & rook l. (eds.), il museo di storia naturale dell’università di firenze. le collezioni geologiche e paleontologiche, 3, 19-55. cuvier g. (1812) recherches sur les ossemens fossiles, où l’on rétablit les caractères de plusieurs animaux dont les révolutions du globe ont détruit les espèces. atlas 1-2. deterville, paris. cuvier g. (1821-1824) recherches sur les ossemens fossiles, ou l’on rétablit les caractères de plusieurs animaux dont les revolutions du globe ont détruit les espèces. five volumes. dufour et d’ocagne, paris. del campana d. (1913) i cani pliocenici di toscana. tipografia successori fratelli nistri. driesch von den a. (1976) a guide to the measurement of animal bones from archaeological sites. peabody mus. bullettin 1, 1-137. forsyth major c.i. (1877) considerazioni sulla fauna dei mammiferi pliocenici e postpliocenici della toscana. memorie della società toscana di scienze naturali, 3, 202-227. garrido g., arribas a. (2008) canis accitanus nov. sp., a new small dog (canidae, carnivora, mammalia) from the fonelas p-1 plioepleistocene site (guadix basin, granada, spain). géobios, 41, 751 -761. hammer ø. (2016) past. paleontologial statistics. version 3.14. reference manual. natural history museum, university of oslo. http://folk.uio.no/ ohammer/past/past3manual.pdf. jiangzuo q., liu j., wagner j., dong w., chen j. (2018) taxonomical revision of fossil canis in middle pleistocene sites of zhoukoudian, beijing, china and a review of fossil records of canis mosbachensis variabilis in china. quaternary international. koufos g.d., kostopoulos d. (1997) new carnivore material from the plio-pleistocene of macedonia (greece) with a description of a new canid. münchner geowissenschaftliche abhandlungen, 34, 33-63. lacombat f., abbazzi l., ferretti m.p., martíneznavarro b., moulle p.e., palombo m.r., rook l., turner a., valli a.m.f. (2008) new data on the early villafranchian fauna from vialette (hauteloire, france) based on the collection of the crozatier museum (le puy-en-velay, haute-loire, france). quaternary international, 179, 64-71. linnaeus c. (1758) systema naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis. in: synonymis, locis, editio decima, tomus i. laurentius salvius, stockholm. reformata. martin r. (1973) trois nouvelles espèces de caninae (canidae, carnivora) des gisements pliovillafranchiens d'europe. documents du laboratoire de géologie de la faculté des sciences de lyon, 57, 87-96. mecozzi b., iurino d. a., berte d. f., sardella r. (2017) canis mosbachensis (canidae, mammalia) from the middle pleistocene of contrada monticelli (putignano, apulia, southern italy). bollettino della società paleontologica italiana, 56 (1), 72. napoleone g., albianelli a., azzaroli a., bertini a., magi m., mazzini m. (2003) calibration of the upper valdarno basin to the plio-pleistocene for correlating the apennine continental sequences. il quaternario, 16, 131-166. pei w.c. (1934) a preliminary report on the latepalæolithic cave of choukoutien. acta geologica sinica (english ed.), 13 (1), 327-358. qiu z.b., deng t., wang x. (2004) early pleistocene mammalian fauna from longdan, dongxiang, gansu, china. palaeontologia sinica, new series c, 27, 1-198. rook l., torre d. (1996) the wolf-event in western europe and the beginning of the late villafranchian. with 2 figures in the text. neues jahrbuch für geologie und paläontologie, 8, 495-501. rook l., croitor r., delfino m., ferretti m.p., gallai g., pavia m. (2013) the upper valdarno pliopleistocene vertebrate record: an historical overview, with notes on palaeobiology and stratigraphic significance of some of important taxa. italian journal of geosciences, 132, 104-125. doi: 10.3301/ijg.2012.16. sotnikova m.v. (2001) remains of canidae from the lower pleistocene site of untermassfeld. in: kahlke, r.d. (ed.), das pleistozän von untermassfeld bei meiningen (thüringen), teil. 2. habelt verlag, bonn, 607-632. sotnikova m.v., rook l. (2010) dispersal of the canini (mammalia, canidae: caninae) across eurasia during the late miocene to early pleistocene. quaternary international, 212, 86-97. simpson g.g. (1941) large pleistocene felines of north america. american museum novitates, 1136, 1-27. teilhard de chardin p., piveteau j. (1930) les mammiféres fossiles de nihewan (chine). annales de paleontologie, 19, 1-134. torre d. (1967) i cani villafranchiani della toscana. paleontographia italica, lxiii, 113-138. torre d., ficcarelli g., masini f., rook l., sala b. (1992) mammal dispersal events in the early pleistocene of western europe. courier forschungsinstitut senckenberg, 153, 51-58. zdansky o. (1924) jungtertiare carnivoren chinas. palaeontologia sinica, new series c, geological survey of china. pp. 223. 172 bartolini lucenti s., rook l. ms. received: may 6, 2018 final text received: may 26, 2018 available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 49 53 birds from the late pleistocene: environmental and climatic scenarios between the alps and the great adriatic plain (north-eastern italy) lisa carrera università degli studi di ferrara, dipartimento di studi umanistici, sezione di preistoria e antropologia, ferrara, italy corresponding author: l. carrera <lisa.carrera@student.unife.it> abstract: in this work we show the potential of bird remains as environmental and climatic proxies, reconstructing the environmental scenarios of the piedmont area of north-eastern italy across the mis3/mis2 boundary, on the basis of the fossil avifauna that we found in rio secco cave (pn) and buso doppio del broion cave (vi) in the berici hills. the results indicate the presence of a mosaic of environments, with open and forested areas and water and rocky habitats in a context of cold climatic conditions as indicated by the finding of the cold-adapted species bubo scandiacus and lagopus muta. keywords: birds, palaeoenvironment, late pleistocene, north-eastern italy, rio secco cave, buso doppio del broion cave 1. introduction western palearctic avifauna consists of more than 500 breeding species, each of which has very specific ecological needs and a strong link with his habitat, particularly with the type of vegetation: this aspect makes fossil avifauna a coherent palaeoenvironmental and palaeoclimatic proxy for the whole pleistocene, as most of extant bird species are reported in the western palearctic since the early pleistocene (tyrberg, 1998, 2008). resident species are more useful than migratory ones for this purpose, as they live in the same habitat during the whole year. fossil birds are also useful to infer past climatic conditions. the pleistocene climatic oscillations have shaped, over the course of time, the range of many species, which followed the shift of their ecological niche. for instance, during cold phases, mediterranean europe represented a “refuge area” for arctic, subarctic and boreal species (e.g. the snowy owl, bubo scandiacus) (holm & svennning, 2014; sanchez marco, 2004). the presence of these species in the fossil record of western palearctic mid-latitudes represents a proxy of a climate colder than present. the fossil record of other bird species, like the rock ptarmigan (lagopus muta), indicates that they were more widespread and lived at lower heights than today during the cold phases, as they followed the descent of the vegetational zones. the finding of these species at low heights in the mid-latitudes, can be used with caution as a climate proxy. we point out that only evidence concerning strong latitudinal or altitudinal changes in the geographic distribution of a bird species should be considered as a climate proxy (bedetti & pavia, 2001; carrera et al., 2018; tyrberg, 2010). we can also infer past climate changes on the basis of the changes in the bird species associations across the layers of a single deposit. this approach can be based, in detail, on the presence of a climate marker in a layer, on changes in the relative abundance of a species, or on variations in the proportion of taxa from different habitats (open, rocky, water, forest) (bedetti & pavia, 2007; tomek et al., 2012). to obtain a representative result, this analysis should be applied to deposits with a high number of bird remains and a long stratigraphic sequence. in this work, we carried out a systematic analysis of the avifaunal remains from the deposits of two palaeolithic sites in north-eastern italy: buso doppio del broion cave (vi) and rio secco cave (pn). in detail, we analysed the avifaunal assemblages coming from the layers referable, from both sites, to the mis3/mis2 boundary, in order to infer past climate and environmental characteristics of this geographic area in a context of increasingly harsher climate (clark et al., 2009; monegato et al., 2017). both sites are located along the connection area between the so-called “great adriatic plain”, the large plain which emerged in the northern adriatic area during the cold phases of the late pleistocene (antonioli, 2012), and the piedmont fringe (fig. 1). the rio secco cave is located on the pradis plateau (eastern carnic pre-alps), at an elevation of 580 m a.s.l. the plateau faces the friulian plain to the south. the late pleistocene sediments cover a time span from 50 to 30 ka, with evidence of short-term gravettian and mousterian occupations. the layer 6, an anthropic layer contained in the macrounit br1, yielded an age of 33,480–30,020 yr cal bp, assessing its placement in the early gravettian period (peresani et al., 2014; talamo et al., 2014). the buso doppio del broion cave is a cavity formed by a system of galleries which opens at 150 m a.s.l. in the eastern slope of the berici hills (an uplifted karst plateau isolated in the https://doi.org/10.26382/aiqua.2018.aiquaconference alluvial plain). the deposits of buso doppio del broion cave, below the upper reworked sediment, contain scanty gravettian lithic implements. the sequence probably covers a time span including the onset of the lgm (layer 1) and the preceding millennia, on the basis of the similarity of the lithic material to a radiocarbon dated palaeolithic site located in the proximity of the cave (gurioli et al., 2006; romandini et al., 2015). the archaeological excavation in these two caves is ongoing, carried out by the university of ferrara. 2. materials and methods the systematic analysis of the avifaunal remains involved 194 avian remains from the macro-units br1 and br2 of rio secco cave, and 775 bird remains from layers 1, 2, 3, 4, 5, 6, 7 of buso doppio del broion cave. the sediments were excavated in 50 × 50 cm or 33 × 33 cm squares and then wet sieved. for the systematic analysis we used two modern bird skeletal comparative collections: the “marco pavia ornithological collection” (mpoc), stored at the dipartimento di scienze della terra of the torino university, and the one held at sezione di scienze preistoriche e antropologiche of the dipartimento di studi umanistici of the university of ferrara. the fossil material is stored in the sezione di scienze preistoriche e antropologiche of the dipartimento di studi umanistici of the university of ferrara. bird taxonomy follows del hoyo et al. (2014, 2016). 3. results we identified a great variety of bird species from the two deposits (tab. 1). the bird taxa recognized in this work all belong to the extant western palearctic avifauna. in the rio secco cave bird assemblage, in detail, we identified 166 remains (85.6 %) which have been assigned to 31 bird taxa (18 species) (carrera et al., 2018). 28 remains are left as indeterminate aves. in the buso doppio del broion bird assemblage, we identified 634 remains (81.8 %) which have been assigned to 69 bird taxa (44 species), while 141 remains are left as indeterminate aves (carrera et al., in press). among the identified remains, for both assemblages, several remains have been attributed to species-level taxa and others to supraspecific taxa, because of their fragmentation or because of the lack of diagnostic features. 4. discussion and conclusion the bird species identified allowed palaeoenvironmental and palaeoclimatic reconstructions. among the bird taxa found at rio secco cave, l. muta and p. collaris suggest the presence of open areas with low vegetation and rocky exposures close to the cave, while p. perdix and c. coturnix indicates the presence of open grasslands/shrublands. l. tetrix, t. urogallus, p. canus, n. caryocatactes, p. pyrrhula and l. curvirostra indicate the presence of conifer or mixed forests, while f. atra suggests the presence of slow-flowing water bodies (cramp, 1998). l. muta is absent today from the area of the site, as it currently lives at higher heights, above the tree line. its presence during the end of mis 3 at about 580 m a.s.l. indicates that mountain open environments had to be located at lower heights, and thus it can be considered an indicator of a climate colder than the current one (carrera et al., 2018). the deposit of buso doppio del broion cave provided a wide range of bird species useful for palaeoenvironmental reconstructions. the presence of open habitats like grasslands, shrublands and steppe is sug 50 fig. 1 map of northern italy with the geographic position of buso doppio del broion cave (a) and rio secco cave (b). the light grey area indicates the extension of the great adriatic plain during the time span investigated. carrera l. 51 tab. 1 bird taxa from the macro-units br1 and br2 of rio secco cave (carrera et al., 2018) and from the layers 1, 2, 3, 4, 5, 6, 7 of buso doppio del broion cave (carrera et al., in press). nr indicates the number of remains for each taxon. fossil birds as a proxy for palaeoenvironmental and palaeoclimatic reconstructions gested by the presence of c. coturnix, p. perdix, g. grus, t. tetrax, a. noctua, b. scandiacus, f. tinnunculus, e. alpestris and cf. p. petronia. other species indicate the presence of rocky cliffs and exposures, such as a. pallidus/apus, a. chrysaetos, p. graculus, p. pyrrhocorax, c. corax, p. rupestris, t. muraria and p. collaris. t. urogallus, l. tetrix, s. ulula, a. funereus, a. gentilis, p. viridis, n. caryocatactes, t. troglodytes, p. pyrrhula and l. curvirostra indicate the presence of conifer or mixed forests. finally, a variety of water bird species such as a. ferina, a. fuligula, s. querquedula, a. platyrhynchos, a. crecca, g. chloropus and g. gallinago, suggests the presence of slow-flowing water bodies, wetlands or marshes near the site (cramp, 1998). the finding of two cold-adapted boreal species, b. scandiacus and s. ulula, both currently absent from the italian avifauna (brichetti & fracasso, 2015), indicates a climate colder than present during the time span investigated. other indications of a climate colder than present is the finding, at low heights of l. tetrix, t. urogallus, p. graculus, p. pyrrhocorax and p. collaris, which currently live, in the alps, in high mountain environments only (carrera et al., in press). the avifaunal assemblages from both the sites provided a coherent environmental framework for the geographic area of connection between the piedmont area and the great adriatic plain, constituted by a mosaic of different habitats. this frame is further supported by the results of the analysis of the pollen records from the fimon lake deposits and the azzano decimo core, in the friulian plain (about 40 km south of rio secco cave) (pini et al., 2009, 2010). during the lgm, the landscape of the piedmont area was constituted by an extensive belt of boreal trees, while the nearby plain was characterized by large steppe habitats, dominated by artemisia and juniper (monegato et al., 2015). despite the richness of the italian palaeornithological record, contributions which deal with avian fossil remains are few with respect to those concerning mammal fossil remains, maybe because of the scarcity of bird skeletal comparative collections. we hope that this field will grow in the near future, as it could provide important advances concerning the palaeobiogeography and palaeoecology of bird species and the evolution of environmental scenarios subjected to the pleistocene climatic oscillations, with the contribution of innovative approaches such as the species distribution modeling (svenning et al., 2011) and phylogenetics. acknowledgements research at the rio secco cave and buso doppio broion cave is coordinated by marco peresani and matteo romandini respectively in the framework of projects supported by the ministry of culture and local institutions and promoters.we are grateful to prof. benedetto sala for his help and precious suggestions, and to ulf johansson (naturhistoriska riksmuseet, stockholm, sweden) for the loan of some crucial recent skeletons. references antonioli f. (2012) sea level change in westerncentral mediterranean since 300 kyr: comparing global sea level curves with observed data. alpine and mediterranean quaternary, 25, 15-23. bedetti c., pavia m. (2001) climate and environmental changes and faunal turnover: the avifauna case history. international conference on paleobiogeography and paleoecology, abstract book, piacenza, 34-35. bedetti c., pavia m. (2007) reinterpretation of the late pleistocene ingarano cave deposit based on the fossil bird association (apulia, south-eastern italy). rivista italiana di paleontologia e stratigrafia, 113(3), 487-507. brichetti p., fracasso g. (2015) check-list degli uccelli italiani aggiornata al 2014. rivista italiana di ornitologia, 85, 31-50. carrera l., pavia m., romandini m., peresani m. (2018) avian fossil assemblages at the onset of the lgm in the eastern alps: a palaecological contribution from the rio secco cave (italy). comptes rendus palevol, 17, 166-177. carrera l., pavia m., peresani m., romandini m. (in press) late pleistocene fossil birds from buso doppio del broion cave (north-eastern italy): implications for palaeoecology, palaeoenvironment and palaeoclimate. bollettino della società paleontologica italiana. clark p.u., dyke a.s., shakun j.d., carlson a.e., clark j., wohlfarth b., mitrovica j.x., hostetler s.w., mccabe a.m. (2009) the last glacial maximum. science, 325, 710-714. cramp s. (1998) the complete birds of the western palearctic on cd-rom. optimedia. oxford university press. del hoyo j., collar n.j., christie d.a., elliot a., fishpool l.d.c. (2014) illustrated checklist of the birds of the world. vol. 1: non-passerines. lynx éditions, barcelona. del hoyo j., collar n.j., christie d.a., elliott a., fishpool l.d.c., boesman p., kirwan g.m. (2016) illustrated checklist of the birds of the world. vol. 2: passerines. lynx éditions, barcelona. gurioli f., cappato n., de stefani m., tagliacozzo a. (2006) considerazioni paleontologiche, paleoecologiche e archeozoologiche dei livelli del paleolitico superiore del riparo del broion (colli berici, vicenza). in atti del convegno nazionale di archeozoologia, rovereto, 5, 47-56. holm s.r., svenning j.c. (2014) 180,000 years of climate change in europe: avifaunal responses and vegetation implications. plos one, 9(4), e94021. monegato g., ravazzi c., culiberg m., pini r., bavec m., calderoni g., jež j., perego r. (2015) sedimentary evolution and persistence of open forests between the south-eastern alpine fringe and the northern dinarides during the last glacial maximum. palaeogeography, palaeoclimatology, palaeoecology, 436, 23-40. monegato g., scardia g., hajdas i., rizzini f., piccin a. (2017) the alpine lgm in the boreal ice-sheets game. scientific reports, 7(1), 2078. peresani m., romandini m., duches r., jéquier c., nannini n., pastoors a., picin a., schmidt i., va 52 carrera l. quero m., weniger g.c. (2014) new evidence for the mousterian and gravettian at rio secco cave, italy. journal of field archaeology, 39, 401-416. pini r., ravazzi c., donegana m. (2009) pollen stratigraphy, vegetation and climate history of the last 215ka in the azzano decimo core (plain of friuli, north-eastern italy). quaternary science reviews, 28(13), 1268-1290. pini r., ravazzi c., reimer p.j. (2010) the vegetation and climate history of the last glacial cycle in a new pollen record from lake fimon (southern alpine foreland, n-italy). quaternary science reviews, 29 (23), 3115-3137. romandini m., bertola s., nannini n. (2015) nuovi dati sul paleolitico dei colli berici: risultati preliminari dello studio archeozoologico e delle materie prime litiche della grotta del buso doppio del broion (lumignano, longare, vicenza). atti della xlviii riunione scientifica dell’iipp, 53-59. sanchez marco a. (2004) avian zoogeographical patterns during the quaternary in the mediterranean region and paleoclimatic interpretation. ardeola, 51 (1), 91-132. svenning j.c., fløjgaard c., marske k.a., nóguesbravo d., normand s. (2011) applications of species distribution modeling to paleobiology. quaternary science reviews, 30(21-22), 2930-2947. talamo s., peresani m., romandini m., duches r., jéquier c., nannini n., pastoors a., picin a., vaquero m., weniger g.c., hublin j.j. (2014) detecting human presence at the border of the northeastern italian pre-alps.14c dating at rio secco cave as expression of the first gravettian and the late mousterian in the northern adriatic region. plos one, 9 (4), e95376. tomek t., bocheński z.m. socha p., stefaniak k. (2012) continuous 300,000-year fossil record: changes in the ornithofauna of biśnik cave, poland. palaeontologia electronica, 15(1), 1-20. tyrberg t. (1998) pleistocene birds of the palearctic: a catalogue. publications of the nuttall ornithological club no. 27, cambridge. tyrberg t. (2008) pleistocene birds of the palaearctic. http://web.telia.com/~u11502098/pleistocene.pdf (accessed on the 1st of november 2017, last updated in 2008). tyrberg t. (2010) avifaunal responses to warm climate: the message from last interglacial faunas. records of the australian museum, 62(1), 193205. 53 fossil birds as a proxy for palaeoenvironmental and palaeoclimatic reconstructions ms. received: april 29, 2018 final text received: may 19, 2018 54 microsoft word 10_rovere_lm05.doc available online http:/amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 25 (2), 2012, iii-v medflood project: mediterranean sea-level change and projection for future flooding alessio rovere1, stefano furlani2, jonathan benjamin3,4, alessandro fontana5, fabrizio antonioli6 1 lamont doherty earth observatory, columbia university, ny 2 university of trieste, it 3 university of edinburgh, uk 4 wessex archaeology coastal & marine uk 5 university of padova, it 6 enea, rome, it corresponding author: a. rovere <rovere@ldeo.columbia.edu> abstract: medflood is a four-year interdisciplinary project recently launched by a team of scientists working in fields concerned with mediterranean sea-level change. the project has the timely and ambitious aim to build a spatially explicit database of relative sea levels for the mediterranean and to use this resource to model risk and help project future flooding in and around the mediterranean basin. keywords: relative sea-level change, mediterranean flooding, sea-level index points, past and future sea levels. 1. introduction it is widely recognized that reconstruction of holocene relative sea levels (rsls) is of fundamental importance for understanding glacio-isostatic adjustment (gia) (and fine-tuning gia models) as well as to assess coastal vulnerability to sea-level rise (cf. antonioli et al., 2009). moreover, holocene rsl data provide information on vertical land movements, even at the local scale, caused by tectonic and/or volcanic structures. in addition to the ‘eustatic’ values provided by the ipcc (lambeck et al., 2011), these are important components of future sea-level projections. the mediterranean sea, with its small tidal ranges and relatively low-energy storms (which favour the preservation of sea-level markers along coastlines) has been the theatre of several studies related to fieldmeasures of past sea levels using rsl markers for over four decades (cf. kershaw and guo, 2001; pirazzoli, 2005). antonioli et al. (2009) reviewed sea-level markers along the italian and istrian (western slovenian and northwest croatian) coastlines, and counted 127 studies containing different rsl markers. other areas where a significant focus on the topic has resulted in a number of studies related to holocene rsl markers carried out include greece, spain and france. the southern part of the basin is characterized by coastal zones where data are lacking or published locally, and are therefore not widely available. in the mediterranean, different types of source data have been used to reconstruct rsls including biological markers (cf. laborel and laborel-deguen, 1994), sedimentological (cf. dubar and anthony, 1995), geomorphological (pirazzoli, 1996) and archaeological (cf. auriemma and solinas, 2009; see also galili and rosen, 2011 for early holocene data from the eastern mediterranean). much greater amounts of published data exists and such literature, still rapidly growing, has led to the obvious consequence of fragmented information. as such, data are only occasionally reviewed with reference to specific location, but not as a whole, since there has never been a concerted effort to compile this into an organic, yet central database which could then be analysed on a truly ‘mediterranean scale’. 2. aims and objectives the main aim of the medflood project, sponsored by inqua for 2012 and of anticipated duration of four years (2012-2015), is to create a comprehensive, coherent, spatially explicit and updatable database containing holocene and mis 5.5 rsl data available in literature for the mediterranean basin. the database, coupled with considerations on vertical land movements due to tectonics, volcanic and isostatic effects, will create an enhanced platform for evidence-supported projections of future sea level which can in turn be used to supplement coastal-flooding models and maps. the database will be freely accessible and downloadable. three subordinate objectives have been identified: 1. conduct a review of observational rsl evidence across the mediterranean for mis 5.5 (132-116 ka) and post-lgm (18 ka) and compare known field data with model predictions (lambeck et al., 2011) coupling them with the evaluation of tectonic and volcanic contributions to the displacement of mis 5.5 markers. 2. produce a web-gis containing mis 5.5 and holocene shorelines, freely accessible by users and fed by input data provided by registered users. rovere a. et al. iv f ig . 1 p os tlg m ( fr om th e ad di tio na l m at er ia l i n la m be ck e t a l., 2 01 1) a nd l as t i nt er gl ac ia l ( m is 5 .5 ) (f ro m th e ad di tio na l m at er ia l i n p ed oj a et a l., 2 01 1 an d f er ra nt i e t a l., 2 00 6) r s l da ta pu bl is he d in r ev ie w p ap er s fo r th e m ed ite rr an ea n. m e d f lo o d a im s to o rg an iz e un de r a si ng le s tr uc tu re a nd e xp an d th es e da ta se ts . t op og ra ph y fr om s r t m d at a (h ttp :// w w w 2. jp l.n as a. go v/ sr tm /m is si on .h tm ). medflood   v 3. obtain future sea-level projections and create model flood maps based on the available digital terrain models and on ipcc sea-level scenarios, taking into account isostatic and tectonic effects. 3. actions medflood was originally designed with the participation of 15 international scientists, experts in different regions of the mediterranean, or in different fields of study concerned with rsl, including gia modelling, archaeology, geology or geomorphology, sedimentology and gis mapping. four project leaders, who will follow the advancement of the project through its duration, lead this group. to achieve its goals, actions will be initiated by medflood, which can be divided into the following categories. networking and dissemination tools this action is focused at establishing a network of scientists (“the medflood team”), coordinated by the four project leaders, who will submit data and cooperate towards the achievement of the project objectives. the team will be updated on the project advancement with a mailing list, and via the website of the project, www.med flood.org. each year, a workshop will be organised, open to scientists working in a relevant field and willing to participate. here, ideas and new approaches to the issues of rsl mapping and future sea-level rise projection will be discussed, with particular emphasis on practical solutions to be implemented for medflood’s success. crowdsourcing and web-gis construction the core idea of medflood is that the most efficient solution to build large databases is represented by ‘crowdsourcing’ (a word introduced in 2006 by j. howe in wired magazine, [whitla, 2009] to describe the process of outsourcing an activity to an undefined (and generally large) network of people in the form of an open call. with this idea, a common structure for submitting rsl data will be established. this will include, but will not be limited to: the type of marker, its elevation and its significance in indicating past sea-level position, and other information relevant for the correct interpretation of the marker (such as tectonic activity in the area). the medflood team (and scientists requesting access) will be asked to fill a web form with this information, in order to obtain a standardized database. the results will be checked for completeness and to avoid duplicate records, and will then be updated into a web gis. from here, a user will be able to query and download the data and to see their spatial representation. future flooding scenarios this action is aimed at defining future flooding scenarios, combining corrections for gia effects across the mediterranean, tectonic uplift/subsidence estimates from the rsl database, and sea-level rise scenarios from ipcc. digital elevation models will be sourced and purchased in the second year of project from national cartographic institutes across the mediterranean, and flooding risk maps will be produced using geospatial statistical analyses. flooding maps will be obtained using the methodology described in lambeck et al. (2011), based on the combined observational-computational solutions. 4. anticipated scientific results the various experts within the medflood team will interact and share field observations for geology and archaeology and modellers of past glacial changes. this will allow us to provide constraints on past sea levels and, where possible, on estimated future sea-level rise. the key achievements of the projects will be: ٠ improved knowledge of mis 5.5 and holocene shorelines along the coasts of the mediterranean; ٠ updated glacial-isostatic modelling for the mediterranean; ٠ enhanced understanding of vertical land movements in the mediterranean; ٠ the creation of a freely accessible web-gis with mis 5.5 and holocene shoreline data; ٠ the creation of regional sea-level rise projections for 2100 using the available dtms; ٠ collaboration with ipcc for the mediterranean sea; ٠ publication of results in international, peer-reviewed scientific journals and online; ٠ dissemination of results to policy makers and managers for planning, land use and hazards related to future sea-level rise. references antonioli f., ferranti l., fontana a., amorosi a., bondesan a., braitenberg c., dutton a., fontolan g., furlani s., lambeck k., mastronuzzi g., monaco c., spada g., stocchi, p. (2009) holocene relative sea-level changes and vertical movements along the italian and istrian coastlines. quaternary international, 206, 102-133. auriemma r., solinas e. (2009) archaeological remains as sea level change markers: a review. quaternary international, 206, 134-146. dubar m., anthony e.j. (1995) holocene environmental change and river-mouth sedimentation in the baie des anges, french riviera. quaternary research, 43, 329-343. ferranti, l., antonioli, f., mauz, b., amorosi, a., dai pra, g., mastronuzzi, g., monaco, c., orrù, p., pappalardo, m., radtke, u., renda, p., romano, p., sansò, p., verrubbi, v., 2006. markers of the last interglacial sea-level high stand along the coast of italy: tectonic implications. quaternary international 145-146, 30-54.galili e, rosen b. (2011) submerged neolithic settlements off the carmel coast, israel: cultural and environmental insights. in: benjamin j., bonsall c., pickard c., fischer a. (eds), submerged prehistory. oxbow, oxford, pp. 272-286. kershaw s., guo l. (2001) marine notches in coastal cliffs: indicators of relative sea-level change, perachora peninsula, central greece. marine geology, 179, 213-228. rovere a. et al. vi laborel j., laborel-deguen f. (1994) biological indicators of relative sea-level variations and of co seismic displacements in the mediterranean region. journal of coastal research, 10, 395-415. lambeck k., antonioli f., anzidei m., ferranti l., leoni g., scicchitano g., silenzi s. (2011) sea level change along the italian coast during the holocene and projections for the future. quaternary international, 232, 250-257. pedoja, k., husson, l., regard, v., cobbold, p.r., ostanciaux, e., johnson, m.e., kershaw, s., saillard, m., martinod, j., furgerot, l., weill, p., delcaillau, b., 2011. relative sea-level fall since the last interglacial stage: are coasts uplifting worldwide? earth-science reviews 108, 1-15. pirazzoli p.a. (1996) sea-level changes: the last 20,000 years. wiley & sons, new york, us. pirazzoli p.a. (2005) a review of possible eustatic, isostatic and tectonic contributions in eight lateholocene relative sea-level histories from the mediterranean area. quaternary science reviews, 24, 1989-2001. whitla p. (2009) crowdsourcing and its application in marketing activities. contemporary management research, 5, 15-28. ms. received: may 2, 2012 final text received: jun 10, 2012 << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /all /binding /left /calgrayprofile (gray gamma 2.2) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /warning /compatibilitylevel 1.4 /compressobjects /tags /compresspages true /convertimagestoindexed true /passthroughjpegimages true /createjobticket false /defaultrenderingintent /default /detectblends true /detectcurves 0.1000 /colorconversionstrategy /leavecolorunchanged /dothumbnails false /embedallfonts true /embedopentype false /parseiccprofilesincomments true /embedjoboptions true /dscreportinglevel 0 /emitdscwarnings true /endpage -1 /imagememory 1048576 /lockdistillerparams false /maxsubsetpct 100 /optimize true /opm 1 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documenti pdf creati possono essere aperti con acrobat e adobe reader 5.0 e versioni successive.) /enu (use these settings to create adobe pdf documents suitable for reliable viewing and printing of business documents. created pdf documents can be opened with acrobat and adobe reader 5.0 and later.) >> >> setdistillerparams << /hwresolution [1200 1200] /pagesize [396.850 566.929] >> setpagedevice amq short notes 26_2 zerboni divito monegato available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 25 (2), 2012, xi xv report on the inqua-aeomed field-trip workshop ‘reconsidering loess in northern italy’ (po plain, 1-3 july 2013) rivka amit 1, andrea zerboni 2 1 geological survey of israel, jerusalem, israel. 2 dipartimento di scienze della terra “a. desio”, università degli studi di milano, italy. corresponding author: a. zerboni <andrea.zerboni@unimi.it> abstract: this report presents the results of the field-trip workshop entitled ‘reconsidering loess in northern italy’ (po plain, 1-3 july 2013), organized in the framework of the aeomed project of the inqua terpro commission. the workshop focuses on presenting and discussing the sources and formation processes of the loess in the po plain area. the sedimentological, palaeopedological, palaeoclimatic and palaeoseismic aspects of five main loess sequences in the po plain (val sorda, gajum, monte netto, ghiardo, boschi di carrega) were presented and discussed in the field. the discussions carried out during three field days aim to map knowledge gaps and to define the next scientific goals in the field of loess research in the po plain in particular and in italy in general . keywords: aeomed; loess; po plain loess basin; upper pleistocene palaeoclimate. introducing the aeomed project the second workshop of the aeomed project, 1-3 july 2013, (loess and aeolian additions to current surface soils and paleosols in mediterranean climate) was aimed to visit and discuss some of the most representative loess sequences along the northern and southern fringe of the po plain loess basin (pplb), northern italy. the main long-term aims of the aeomed project (https:// ppsg2011.uni-hohenheim.de/94176), which is part of the terpro commission of inqua, are: (i) to assess the spatial pattern of loess deposits across the mediterranean: (ii) to analyze loess successions in similar geomorphic units of various mediterranean environments; (iii) to estimate the potential of dust emission and deposition in the various mediterranean environments, based on the underfig. 1 map illustrating the distribution of loess in the po plain (modified from cremaschi, 1990); the sites visited during the workshop are also indicated. 1) pre-quaternary bedrock; 2) alluvial plain; 3) present-day sea extent; 4) moraine systems; 5) loess on fluvial terraces and moraine ridges; 6) loess on karst plateaus; 7) loess in rock shelters; 8) loess on erosional surfaces; 9) direction of dominant winds during loess sedimentation; 10) possible sw boundary of the loess basin. amit r., zerboni a. xii standing of the mechanisms of dust and loess generation, transportation and deposition. short term aims of aeomed project for the following two years (2013-2015) are: (i) to reconsider the loess in northern italy, mainly the po plain loess; (ii) to study loess sites with non glacial aeolian loess deposits, specifically loess and dust derived from the sahara desert in sites at the central and southern italy; (iii) to map the loess in italy along a north-south climatic transect. this project will contribute to identify sources of recent and palaeo-dust/loess around the mediterranean sea and to evaluate rates of loess/dust deposition in the context of palaeoclimate reconstructions, and soil formation processes. the workshop held in italy on july 2013 entitled ‘reconsidering loess in northern italy’ was aimed to bring together loess experts from italy and elsewhere to discuss the loess topic in italy in the context of the loess issue in europe and around the mediterranean basin in several key sites at the pplb. basic questions were discussed such as variety of loess types, sources of the different loess types, climatic deriving forces for loess transportation and deposition, loess accumulation processes, the formation of loessial soils in glacial and non-glacial environments and its paleoclimatic implications. the workshop was organized by r. amit, a. zerboni, e. costantini, s. carnicelli, m. cremaschi, f. livio, and a.m. michetti as part of inqua terpro activities. wide board of expertise attended at the meeting (30 scientists) including geomorphologists, palaeopedologists, sedimentologists, quaternary geologists, geoarchaeologists and palaeoseismologists. in addition 9 grants were available for young researchers from italy, israel and mexico. additional support, derived from the università degli studi di milano, università degli studi dell’insubria, università degli studi di fig. 2 the participants to the workshop visiting the val sorda sequence. fig. 3 a detail of the loess/paleosols sequences deformed by a gravity graben at monte netto; note the thick red paleosol buried by loess. reconsidering loess in northern italy workshop firenze and cra-abp, allowed opening new trenches and soil pits at each study site. reconsidering loess in northern italy: an example of the extensive po plain loess in the framework of european terrestrial palaeorecords, the loess in italy in general, and the loess in the po plain in particular, represents an extraordinary sedimentary record for palaeoenvironmental reconstructions (fig. 1). despite of many systematic studies carried out in the last decades on loess sequences located at northern, eastern and southern margin of the po plain, loess in italy is somewhat overlooked in comparison to the classical sequences described in central and north europe. as a result, crucial data are excluded from the analyses and interpretations of the loess in europe. the term loess refers herein to silty sediments, which have been transported and accumulated by aeolian activity (cremaschi, 1987a). however, because the loess deposit in northern italy are generally thin and can be affected by synand post-depositional weathering, soil formation and colluviation, sometimes their characteristics do not fully meet the standard requirements generally accepted for classical loess. thus the identification of loess in all studied sites was based on geomorphological criteria, textural and mineralogical characteristics and geoarchaeological evidence (cremaschi, 1987a; 1990). two of the visited sites are located in the eastern part of the garda lake area (fig 2). the val sorda sequence is a 5 m-thick, very well preserved upper pleistocene stratigraphic section consisting of the succession of a till, capped with a rubified eemian paleosol, which is overlain by a colluvial layer and a thick loess unit, which includes three chernozem paleosols (cremaschi, 1987b; ferraro, 2009). the loess sequence is capped, compacted and preserved by glacial deposits dated to mis 2. the texture of the loess is sandy silty with no much clay. the well sorted silt and fine sand composed mainly by muscovite and quartz with subangular quartz grains. the age of the upper chernozem -like soil derived from humic acids is c. 28 ka bp (cremaschi, 1987b); osl and irsl dating yield an age for the aeolian deposition between c. 63 and 19 ka bp (cremaschi, 1987b; ferraro, 2009). the importance of val sorda loess sequence is its high degree of preservation. the fact that the original features of the loess and loessial soils are well preserved is the result of the burial by the uppermost thick moraine deposits that isolate the loess sequence from later and recent pedogenic processes. the loess sequence at gajum site (cremaschi, 1987b) is similar to the loess sequence at val sorda, with local colluvial material present at the bottom and aeolian loess at the top. differently from the loess section in val sorda, the loess in gajum site was accumulated in a depression at the top of a karst plateau and was not buried by any glacial or fluvial deposit. thus it was subject to continuous weathering and pedogenic processes, resulting in more weathered loess deposit; radiocarbon ages indicate that loess deposition occurred up to c. 42 ka bp (cremaschi, 1987). monte netto site (capriano del colle, bs) is an isolated hill in the middle of the northern po plain (fig. 3), whose growing is due to the amplification of a buried thrustrelated anticline since the middle pleistocene (livio et al., 2009). a highly rubified, polycyclic paleosol covered by few tens of centimeters of loess characterize the top of the anticline. at the distal part of the exposure the thickest loess sequence of the whole pplb is found. the continuous growing of the anticline during the late quaternary allowed such an exceptional thick accumulation of loess. the upper part of the section corresponds to at least three events of aeolian sedimentation, two of which are osl dated to the upper pleistocene, while a later aeolian actifig. 4 loess sequences at the southern fringe of the pplb: (a) the participants discussing the significance of loess and paleosols at the ghiardo site; (b) the loess sequence at the boschi di carrega site. note in (b) a deep and dark horizon with high concentration of mn concretions. xiii amit r., zerboni a. xiv vity has been radiocarbon dated to the end of the lgm. loess sedimentation at monte netto started after an intensive phase of pedogenesis of fluvial sediments, likely occurred under interglacial conditions. this produced a highly rubified paleosol rich in illuvial clay. subsequent weathering phases gave rise to the formation of paleosols progressively less rubified and rich in clay toward the top of the sequence, which may correspond to several upper pleistocene interstadials. palaeopedological indeces also confirm a progressive reduction of the intensity of pedogenesis rate during the upper pleistocene. textural changes between fresh and weathered loess is underlined by the occurrence of horizons showing a high concentration of manganese concretions. the sequence also preserves evidence of strong palaeoearthquakes, which contributed to the displacement of the loess strata and the pedological horizons (livio et al., 2009). the last two sequences are located at the foot of the apennines (fig. 4), and are represented by thick loess strata covering deeply weathered pleistocene fluvial sediments. the aeolian loess went through intense to moderate pedogenesis, which result in different loessial soil profiles in each site. in the soils we generally identify processes of accumulation of illuvial clay, decalcification, and acidification, which were followed by release, translocation, reduction/oxidation and precipitation of mn and fe through hydromorphism (cremaschi, 1987b). ghiardo site (cavriago, re) is a complex loess sequence, deposited on pleistocene alluvial terraces (cremaschi, 1987b). this sequence records an upper pleistocene aeolian sedimentary phases of loess accumulation (c. 63 to 36 ka bp), which underwent intense weathering processes. moreover, the surface buried by loess and its initial phase of deposition are contemporaneous with the dwelling of mousterian hunters, while the top part of the soil bears traces of chalcolithic land management, which appears to have influenced the soil forming processes. the high terrace of boschi di carrega (collecchio, pr), is covered by loess accumulated during the late pleistocene. this loess sequence correlates with the loess sequence of the ghiardo terrace. soil data collected since the 60s (ferrari and magaldi, 1968), show deep horizons developed in loess, forming complex soils with most of them acidified at the top. to sumarize, although the loess deposits and loessial soils in each site were slightly different, the main sedimentological and pedological characteristics are similar mainly in their stratigraphic appearance, particle size distribution, and mineralogy. in places where the loess was not buried by fluvial or fluvio-glacial sediments and was subject to continuous pedogenic processes the loess is more weathered and more clayey. this arise the possibility that the loess in the po plain is derived from the same local sources, which might be the po flood plains and the po influents, which were exposed during glacial time for long periods and were subject to intense winds at that time. possibly, the combination of increased wind strength with availability of sediments allowed the formation and/or transportation and deposition of loess over a large area, from fig. 5 group photo of part of the participants to the aeomed workshop. reconsidering loess in northern italy workshop the adriatic coast to the inner part of the po plain, at the foot of western alps (cremaschi, 1990). the fact that most of these loess areas were not covered by ice during glacial times, arise the possibility that the source for the loess can be primary silt size fractions or local proximal sands, which were subject to aeolian abrasion to form silt size grains. these preliminary assumptions should be supported by more data and more studies, which will be conducted in the near future. concluding remarks and future work the results of this workshop will be the basis for planning the next steps of the aeomed project working group, which will aim to study the non-glacial loess of italy (e.g., costantini et al., 2009). the data from the non-glacial loess will be later compared to the glacial loess type in the pplb and around the mediterranean to better understand the process of loess formation, transportation, accumulation, distribution and its association with soil formation and climate. in a wider perspective, as italy represents a natural bridge between the north africa/sahara and europe, it would be important to understand any contribution of saharan dust to italian loess, to compare it to the extant dust flux and to infer any possible modifications triggered by recent global changes. during the conclusive discussion, we decided to integrate all information regarding the loess in the pplb to draw a map showing the distribution and properties of the loess sediment and soils. the map of pplb will be published in a collaborative paper, which will present and interpret all published and new data regarding the loess in northern italy. the newly opened loess-soil pits will be dated by osl, and results integrated with published and unpublished ages for loess formation to get a better time constrain on the loessial periods in the po plain. references costantini e.a.c., priori s., urban b., hilgers a., sauer d. protano g., trombino l. (2009) multidisciplinary characterization of the middle holocene eolian deposits of the elsa river basin (central italy). quaternary international, 209, 107-130. cremaschi m. (1987a) loess deposits of the plain of the po and of the adjoining adriatic basin (northern italy). in: pecsi m., french h.m. (eds.), loess and periglacial phenomena. akademiai kiado, budapest, 125140. cremaschi m. (1987b) paleosols and vetusols in the central po plain (northern italy). a study in quaternary geology and soil development. edizioni unicopoli, milano, pp. 306. cremaschi m. (1990) the loess in northern and central italy: a loess basin between the alps and the mediterranean sea. c.n.r., centro di studio per la stratigrafia e petrografia delle alpi centrale, milano, italy, pp. 187. ferrari g., magaldi d. (1968) i paleosuoli di collecchio ed il loro significato. ateneo parmense-acta naturalia, 4, 57-92. ferraro f. (2009) age, sedimentation, and soil formation in the val sorda loess sequence, northern italy. quaternary international, 204, 54-64. livio f.a., berlusconi a., michetti a.m., sileo g., zerboni a., trombino l., cremaschi m., mueller k., vittori e., carcano c., rogledi s. (2009) active fault-related folding in the epicentral area of the december 25, 1222 (io = ix mcs) brescia earthquake (northern italy): seismotectonic implications. tectonophysics, 476, 320-335. ms. received: october 15, 2013 final text received: october 15, 2013 xv ojs301 visentin et al def.pdf available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 35 (1), 2022, 47-68 1. introduction our knowledge of the intra-site spatial organisation of mesolithic settlements in italy is still relatively limited. one of the reasons for this is that most sites were explored on limited surfaces and in past decades, when there was little attention to such aspects. nowadays, it is widely recognised that only the data generated by extensive excavations and analysed with a multidisciplinary approach can allow to catch the details of settlement dynamics and the complexity of the functional organisation of spaces. a confirmation of the high potential of this approach is represented by the numerous open-air contexts that were extensively excavated in the central-northern sectors of europe. in these sites, it was possible to obtain important information on the settlement organisation and identify different features (coutard et al., 2010; kind, 2013; mordant et al., 2013; séara & roncin, 2013; among others). such contexts are rarer in the southern part of the continent, especially those excavated on relatively large surfaces. therefore, their contribution is crucial to broaden our knowledge of the complexity of the organisation of mesolithic spaces and open new perspectives on the functional roles of different locations and sites (cf. amiel & lelouvier, 2003; martinez-moreno & mora torcal, 2011; boric et al., 2014; bonsall & boroneant, 2018). regarding the italian territory, hundreds of mesolithic sites have been discovered during the past decades, particularly in the alpine region (broglio, 1992; cusinato et al., 2003; fontana et al., 2011; 2016). these discoveries allowed a fairly consistent perception of the evolution of technical systems, settlement choices and subsistence strategies of mesolithic groups (cristiani, https://doi.org/10.26382/amq.2022.03 a new early holocene settlement in central italy: the mesolithic site of contrada pace (marche region). davide visentin1,2, alessandro potì2, michele bassetti3, stefano bertola2, marialetizia carra4, gloria cattabriga2, arianna cocilova2,5, emanuela cristiani4, alessandra d’ulizia6, noemi dipino7, nicolò fasser2, alex fontana7, marco palmieri8, federica fontana2, marco peresani2,9, paola mazzieri10, stefano finocchi10 1 archaeology of social dynamics group, institución milá y fontanals, csic, barcelona, spain. 2 dipartimento di studi umanistici, università degli studi di ferrara, ferrara, italy. 3 cora società archeologica s.r.l., trento, italy. 4 dante diet and ancient technology laboratory, sapienza università di roma, roma, italy. 5 dipartimento di storia, archeologia, geografia, arte, spettacolo, università degli studi di firenze, firenze, italy. 6 società cooperativa archeolab, macerata, italy. 7 muse museo delle scienze, trento, italy. 8 phoenix archeologia s.r.l., bologna, italy. 9 istituto di geologia ambientale e geoingegneria, cnr, milano, italy. 10 soprintendenza archeologia, belle arti e paesaggio delle marche, ancona, italy. corresponding author: davide visentin <davide.visentin@imf.csic.es> abstract: early holocene hunter-gatherer settlements are spread throughout italy and testify to the exploitation of very different landscapes. nonetheless, their preservation state is not always exceptional. this is not the case for contrada pace, an archaeological site recently discovered on a terrace of the chienti river in central-eastern italy. this paper reports on the geomorphological, pedo-stratigraphic, and archaeological record of one of the most complete and well-preserved early mesolithic open-air sites in italy and southern europe. micro-stratigraphic excavations extended over more than 500 square meters have exposed a buried paleosol with anthropogenic features, which contained thousand lithic artefacts and organic remains framed in the context of a primary forest. these findings appear clustered in different functional areas that yielded multiple structured features. the field evidence integrated by radiocarbon dating and archaeobotanical, archaeomalacological and zooarchaeological data allowed to propose a first interpretation of the general structure of the site and the most significant features. keywords: early holocene; mesolithic; open-air sites; river terraces; escargotières. 48 visentin d. et al. 2009; fontana & guerreschi, 2009; wierer et al., 2016; visentin, 2018; gazzoni et al., 2021). nevertheless, only few of them were excavated over surfaces large enough to allow the identification of specific features and were the object of spatial analyses enabling the reconstruction of their internal organisation. in most cases, such evidence attests to isolated and small size habitation units/specialised areas, usually characterised by single hearths either open air or under rock shelters/rock boulders (bagolini & dalmeri, 1987; baroni & biagi, 1997; fontana & vullo, 2000; kompatscher et al., 2016; visentin & fontana, 2016; among others). a few of these sites also show paved areas made with local stones (broglio, 1972; fontana & vullo, 2000). in central-southern italy, our knowledge of the mesolithic is more limited as the number of investigated sites decreases drastically, both along the adriatic and tyrrhenian sides, as well as in the most internal apennines regions (lo vetro & martini, 2016). moreover, almost all this evidence concerns cave and rock-shelter sites which were excavated over limited surfaces. therefore only very few of these sites have allowed to identify some evidence of spatial organisation of inhabited spaces as it will be further discussed (tagliacozzo & piperno, 1993; bevilacqua, 1994; mussi et al., 1995; lubell et al., 1999; girod, 2011). for this reason, the recent discovery and extensive excavation of a new early mesolithic site in the marche region, in the locality known as contrada pace (tolentino, macerata), represents a unique opportunity to investigate in detail intra-site settlement dynamics in an open-air context with an exceptional preservation state and richness of the deposit. for the mid-adriatic region, this site represents the only evidence so far discovered dated to the early mesolithic although the poor preservation of the lithic assemblage from pieve torina, another site located in the marche region, does not allow us to exclude an occupation also including an early mesolithic (sauveterrian) phase before the one referred to the late mesolithic (castelnovian) (martini, 2006). this paper presents the first overview of the stratigraphic, zooarchaeological, malacological, archaeobotanical and archaeological evidence discovered at contrada pace. although the study stands still at a preliminary stage, data collected during the excavation and the first laboratory analyses already provided support for understanding the spatial structure of the site and some taphonomic and anthropogenic features. 2. geomorphological setting the chienti river is one of the major rivers of the adriatic side of central italy and, similarly to the other rivers in the marche region (lipparini, 1939; villa, 1942; coltorti et al., 1991), it forms a system of fluvial terraces along most of its course. in the distal mid-segment, the chienti valley is asymmetrical, with the southern side presenting a stepped profile and the northern side characterised by a sequence of pleistocene terraces at progressive elevations, originating from the interference of tectonic uplift with major cold climatic phases (coltorti et al., 1991). the late pleistocene deposits are thick. the massive central gravelly bodies originated under a braided fluvial pattern during the last glacial maximum when all the marche rivers were tributaries of the po river in the great adriatic po region (calderoni et al., 1991; peresani et al., 2021). the terrace of contrada pace was attributed to the late pleistocene based on characteristics shared with other marche rivers. it is a thick sedimentary body made of horizontal and massive gravels, sometimes interfingered with sands and silts, related to a broad, aggrading braid-plain extended towards the continental platform of the north adriatic sea. comparably to other terraces, luvisols evolved on the top of the depositional surface (cilla et al., 1994, 1996). the evolution of this river during the holocene was likely characterised by the modelling of unpaired terraces generated during the progressive downcutting of the valley (cilla et al., 1996). the oldest phase was characterised by prolonged aggradation of the fluvial plain up to the early-middle holocene when a substantial decrease of the solid load induced the incision and the evolution of the braid-plain to a meander pattern of clear water rivers. during the following phase, meander terraces evolved with the incision increase, even affecting the bedrock in the piedmont area. a few kilometres to the north, radiometric dating of the potenza river deposits suggests that the evolution of this system occurred from ca. 8000 up to 4000 cal bp. this development of the early-mid holocene terraces is also indicated in other valleys, like the tronto valley, by the presence of neolithic settlements (coltorti & farabollini, 2008). 3. materials and methods preventive archaeological research uncovered significant early mesolithic evidence in a wide area east of tolentino (macerata, marche region, central italy) along the chienti valley (fig. 1a). a total surface of almost 40,000 m2 was explored by digging 2 m wide trenches. this allowed to delimit the area of interest to a surface of around 5250 m2. the first excavated plot was the one denominated contrada pace 1 (cp1; fig. 1c). here, the top of a buried paleosol (cf. section 4) was reached under a 1-1.5 meter thick fine alluvial sedimentary cover on a surface of around 920 m2; subsequently, an extensive excavation took place over a surface of 499 m2. the excavation was carried out manually. all artefacts and ecofacts larger than 1 cm were individually positioned using a total station (13,478 points). sediment was removed according to a 50x50 cm grid following the stratigraphic approach, with units defined on a lithological base. for the areas with the highest density, all the sediment referable to the mesolithic surface was collected in plastic bags and stocked at the university of ferrara. totally, 1304 plastic bags were filled, corresponding to roughly 19 tons of sediment. the material is currently being processed in the laboratories of the university through floatation and water screening (meshes of 400 μm and 1 mm, respectively) to recover small items and anthracological, carpological, and malacological remains. an extensive sampling strategy led to the collection of numerous undisturbed soil samples for micromorphological analyses and loose soil samples for pollen, phytoliths, and other sedimentological analyses. malacological remains were collected using the refer 49 a new early holocene site in central italy: contrada pace ence grid and stocked in plastic boxes. faunal remains were characterised by a poor preservation state and were thus consolidated in the field using acril 33 (acrylic resin in aqueous dispersion). around 300 meters to the east of cp1, a second terrain plot (contrada pace 2 cp2) was investigated and allowed to confirm the presence of early mesolithic evidence over a vast stretch of land parallel to the chienti river. considering that construction activities would not have affected the archaeological layer, it was decided not to investigate the site extensively. archaeological activities were aimed at documenting the stratigraphic sequence and mapping the extension of the site. a small excavation (10 m2) was carried out in one of the trenches with the highest density. overall, the evidence brought to light at cp2 by trenches, test pits, and the 10 m2 excavation indicates the presence of numerous lithic scatters and other significant features such as two escargotières (fig. 1c). the stratigraphic and chronological (on technotypological grounds) evidence of the two sites is comparable. soil horizons have been described according to the fao guidelines (2006). the symbology for the soil classification and the definition of the horizons follows the criteria of soil taxonomy (soil survey staff, 2010). fig. 1 geographical (a) and geological (b) setting of the site and map showing the excavation areas and trenches (in red) that yielded mesolithic evidence (c). map layers downloaded from geoportale nazionale (http://www.pcn.minambiente.it/). soil classification follows the "world reference base for soil resources" (iuss working group wrb, 2015). colours have been determined in the wet state and codified with the munsell® soil colour charts (2000). preliminarily, three thin sections have been analysed: mm9 (f3), mm15 (enclosed space), and mm17 (escargotière). thin sections were prepared by the "laboratorio servizi per la geologia" (piombino, livorno) according to the method proposed by murphy (1986). their analysis has been carried out with a prior scientific mp3500a microscope with polarised light at 20, 40, 100, and 400 magnifications. the description follows the criteria adopted by stoops (2021) while for the interpretation the references are stoops et al. (2018), nicosia & stoops (2017). radiocarbon dating was performed on three samples of corylus avellana (su10, su11, and su15) that were sent for ams radiocarbon dating to the oxford radiocarbon accelerator unit (orau) of the university of oxford. the calibration of 14c dates was performed using oxcal v4.4.4 (bronk ramsey, 2021) and the intcal20 calibration curve (reimer et al., 2020). regarding carpological analysis, 37 soil samples from stratigraphic unit (su) 10 underwent manual floatation in water to recover all the plant macro-remains. the samples volume is not even, depending on the thickness of the layer at a specific location (the entire sediment of the su was collected). overall, more than one litre of residue is derived from more than 600 litres of soil floatation. the dried residue was screened under the stereomicroscope (axio zoom v16 with magnifications ranging from 10x to 100x) to extract malacofauna, microfauna, and plant macro remains (appendix a). during this phase, anthracological remains larger than 3 mm were also sorted out for future analyses. the determination of the carpological remains was based on the comparison with specific atlases (mainly cappers et al., 2012; www.actaplantarum.org) and a collection of modern seeds and fruits stored at the dante laboratory (sapienza university of rome); pignatti (2017) is the reference text for botanical nomenclature. the determination and taxonomic attribution of malacological remains was carried out following the works of fiorentino et al. (2016), kerney & cameron (1999), and welterschultes (2012). the minimum number of individuals (mni) for each species was calculated by separately counting all unique morphological features (i.e., protoconch, lips, opercula) and then considering the one with the highest value. the taxonomic and anatomical determination of animal bone fragments was performed by comparing the archaeological material to the reference osteological collection of current and paleontological/archaeological fauna of the muse science museum of trento. the following indices were used to estimate the abundance of the species: nrdt, the number of remains determined anatomically and taxonomically (grayson, 1984); mni, 50 visentin d. et al. fig. 2 contrada pace 1 (cp1), left: monolith mm30; right: stratigraphic sequence (su: stratigraphic unit). in red within the rectangle: lithic industry. lol et al., 2017). most likely, these represent the result of primary deposition events and can be preliminarily interpreted as knapping spots (fig. 4). the scatters are composed of artefacts made from different lithologies. in some cases, hammerstones were identified next to them. in the northern sector, bone remains are rare. the minimum number of individuals (lyman, 1994); nisp, the number of identified specimens (lyman, 1994). the estimation of the age of death was based only on the analysis of teeth eruption and degree of wear. for roe deer (capreolus capreolus, l. 1758), the evaluation of the eruption time was done using the ranges proposed by mustoni (2002), while for the degree of wear, the tables by tomé & vigne (2003) were used. for wild boar (sus scrofa, l. 1758), the eruption time was evaluated through the comparison with the tables proposed by habermehl (1961) and the teeth wear with those by grant (1982). 4. the sedimentary sequence the sedimentary sequence of the contrada pace cp1 site was described on the eastern section of the excavation in correspondence with monolith mm30 (tab. 1; fig. 2). here, four fluviatile aggradation cycles (overbanks) were recognised. the buried soil on which the mesolithic occupation took place (ssuu9-5) is characterised by silty-clay loam texture (profile 4abcb-4bwb-4bwcb -4cc) and is classifiable as an inceptisol (iuss working group wrb, 2015). the main observed processes in the buried soil are the accumulation of organic matter (including charcoal and microcharcoal), decarbonation, and weak shrinking and swelling phenomena due to the action of clay feeded by changes in the humidity rate. the cyclic repetition of this process in the upper portion of the sequence (su9) resulted in an angular, prismatic structure with vertical and subhorizontal cracks. the mesolithic stratigraphy is sealed by a thin alluvial cover (su3) on which a 3abcb horizon with characteristics similar to su9 developed. the prosecution of the alluvial aggradation (su2) attests to the development of two inceptisols bcg-2ccg1-2ccg2 (soil survey staff, 2010) marked by weak traces of water stagnation and carbonate illuviation. consequently, secondary caco3 concretions and coatings are frequent all along the sequence. subactual agricultural activities truncate the upper portion of the sequence. 5. main archaeological features the excavation of the cp1 site yielded numerous anthropogenic structures and natural features distributed all over the investigated area (fig. 3). the northern sector is characterised by multiple overlapping lithic scatters distributed around a simple open hearth (f1; sensu mal 51 a new early holocene site in central italy: contrada pace tab. 1 archaeo-pedologic description of the stratigraphic sequence of monolith mm30. 52 visentin d. et al. the central area is characterised by a large and rich scatter of lithic artefacts and bone remains surrounding a wide escargotière (cf. 5.2) composed of tens of hundreds of shells (su10). noteworthy is the presence of a small and irregular pit (su14) at the centre of the midden, with numerous thermally altered centimetric pebbles in its filling. overall, this area may be interpreted as a toss zone dedicated to the disposal of stone tools and wastes. a charcoal-rich layer partially covering a structured fig. 3 map of the central area of the excavation with the indication of the main features discovered. the dashed line delimits the trench that led to the site's discovery. hearth (f3) was identified to the south. this structure will be described in detail in sub-section 5.3. this area presents a much lower density of artefacts than the other excavation sectors. to the east of this latter, another extremely rich area was identified. also, in this case, lithic artefacts, bone remains, and burnt clay chips seem to be connected to maintenance activities and the use of this sector as a dumping zone. next to it, another structured hearth was found (f4). this latter presents very large dimensions (more than 1 m in diameter) and covers a smaller escargotière. the area south of the dirt road is characterised by the presence of small lithic scatters and a simple open hearth (f5). in all of the sectors, numerous natural features are attested. these are represented by the traces left by tree roots (tree holes). in some cases, they result from the decomposition of the plant in a living position (fig. 5a). in others, it is possible to interpret them as treethrown, i.e., the result of the uprooting of the tree by either natural or human agents (fig. 5b-c). excavation data allowed to propose a relative chronology for the decomposition or tilting of the trees. this event mostly preceded the human occupation of the area. more rarely, it occurred contextually to the deposition of the stratigraphic unit covering the archaeological layer (su2). it is also interesting to note that some of the tree stumps were burned, although it is not yet possible to assess whether this was the result of human activity or not. generally, these natural features seem to have played an attractive role in the spatial distribution of some of the evidence uncovered at the site. 5.1. combustion structures three out of five combustion features identified during the excavation are simple open hearths with a diameter of a maximum of 50 cm (f1, f2, and f5). they derive from fires lit directly on the clayish soil and consist of sub-circular burned (oxidised) spots of sediment of orange colour (fig. 6a). as a rule, the active surfaces are horizontal, while the thermal alteration of the sediment reaches a depth between 3 and 7 cm and is lensshaped, being the thickest at the centre. the sediment surrounding the combustion features is characterised by chert artefacts, fragments of animal bones, charcoal, and dispersed concentrations of small aggregates of burned clay. such clay chips may indicate the clear-out of the hearths or disaggregation phenomena due to erosion. the remaining two combustion features (f3 and f4) were identified at the centre of the sheltered area and on the northeast side of the dumping zone, respectively (fig. 6b-c). these features consist of a 4-to-6 cm 53 a new early holocene site in central italy: contrada pace fig. 4 a scatter of lithic artefacts on chert from the scaglia rossa formation and a hammerstone. fig. 5 a) the tree-hole left by a plant that decomposed in a standing position; b) a typical tree-thrown that led to the verticalisation of the stratigraphic sequence. the two depressions are filled by the yellowish sediment of stratigraphic unit 2, indicating that the uprooting preceded the deposition of the alluvial cover that buried the paleosol; c) a tree-thrown in which part of the dark soil sediment is floating in the yellowish matrix. in this case, the uprooting happened after the deposition of stratigraphic layer 2. 54 visentin d. et al. thick plate of clayish-silty sediment deliberately laid on the grass to form a relieved surface. this contained combustion feature can be classified as a prepared burning surface (mallol et al., 2017). while the structured hearth f3 measures ca. 50 cm in diameter, the one located near the dumping zone (f4) measures over one meter, representing the largest combustion structure discovered at the site. the clayey-silty layers present a maximum thickness of 4 cm for feature f3 and 6 cm for feature f4. in structure f3, below the burnt layer of clay and silt, it was possible to recognise the remains of the original organic soil burnt in an anoxic environment (fig. 6d). this structure was radiocarbon dated to 10,203-9913 cal bp (cf. appendix b). conversely, the hearth of the dumping zone was built on top of an escargotière. also, in this case, the presence of patches of dark sediment indicates the development of the soil's organic level and its partial preservation under the burnt clayey-silty plate. thin section mm9 refers to the "prepared burning surface" named f3 (fig. 7). the lower part of the structure is characterised by a ca. 2 cm thick blackish combustion substrate (cs1; fig. 7a). this substrate was formed in a reducing environment due to pyrolysis phenomena of the fine organic matter of the occupational surface su9. the formation of partially accommodated fine angular blocky peds with planar voids and blackened heated granular aggregates is attributable to the effects of combustion on poorly vegetated soils (courty et al., 2012; mallol et al., 2013; friesem et al., 2014; fig. 7b). similarly, isolated microaggregates can also be found embedded in the groundmass of su3, which covers the mesolithic surface. the rubified heated aggregates represent the residues of the original burning surface (combustion substrate cs2 = su15; fig. 7a). the features of the rubified aggregates' groundmass (cf. limit, coarse components, micromass) are similar to those of su9. following recent experiments performed under controlled conditions (aldeias et al., 2016), rubefaction on similar substrates is obtained at temperatures above 240 °c, with the transition from goethite to hematite. burnt residues such as coal and ash are poorly preserved. pseudomorphs of plant tissues are detectable within the micromass. modifications produced by the impact of soil macrofauna on soil formation are indicated by the presence of a large burrow infilling (fig. 7a). overall, the combustion feature f3 has been partially reworked by post-depositional phenomena of biological origin. the development of the post-abandonment incipient soil su3 gave the combustion feature a polyhedral aggregation formed by fine angular blocky peds with unaccommodated planes wholly filled with a silty-clayey matrix. finally, the profile is affected by the process of fig. 6 some of the primary combustion features discovered at the site. a) simple open hearth testified by an oxidised spot of sediment; b) top view on the contained combustion feature named f3; c) oblique view on the contained combustion feature named f4, the largest of the site; d) a stratigraphic section of feature f3 in which the oxidised layer of sediment laid to prepare the burning surface is well visible on top of the burnt organic substrate. in transversal cut (fig. 9e) and one fishbone present the typical denticulated edge (fig. 9d). under polarized light, the bones show a light yellow-to-grey colour, while with crossed polarizers, interference colours vary from weakto-moderate grey to white. these optical characteristics indicate that fishbones were heated at around 300°c (villagran et al., 2017). the possible presence of herbaceous plants shall be further investigated. the escargotière is covered by a thin alluvial cover (su3) composed of a silty-clay loam matrix. the subsequent pedogenetic phase resulted in a well-developed subangular to angular blocky microstructure. the biologic activity brought about the partial dislocation of some faunal remains within su3. 5.3. an enclosed space close to the most extensive escargotière (su10), a charcoal-rich layer named stratigraphic unit 11 was found (fig. 10). this was characterised by well-defined limits (in particular westward) and a half-moon shape. the layer was radiocarbon dated to 10,160-9779 cal bp (cf. appendix c). it presents a loam-clayey matrix rich in millimetric and centimetric charcoal fragments and has an average thickness of a few centimetres (up to 5 cm). at its centre is located the combustion structure named f3. the burnt clay layer of this latter (su15) is partially covered by su11. in the surroundings, three tree holes were found. the first one (c8) corresponds to a partially burnt tree hole and is directly connected to the charcoal layer as the latter ends in correspondence with the former. the two others are probably tree-throws. one of the two (c10) results from an event that preceded the carbonate illuviation in the form of complex microsparitic carbonate infillings in a non-carbonatic groundmass (fig. 7c). 5.2. escargotières the largest of the two escargotières identified (su10), located a few meters nw of the charcoal-rich area (su11), covers a surface of over 6 square meters (fig. 8a). it is composed of hundreds of land-snail shells of the species helix cf. pomatella (cf. section 6.3) along with lithic artefacts, osseous fragments, burnt clay chips, and small centimetric limestone pebbles (1-3 cm) embedded in a silty-clayey loam (fig. 8b). charcoal occurs abundantly throughout the unit. radiometric dating of this unit indicated an age of 11,06810,581 cal bp (cf. appendix b). the thickness of the layer ranges from 4-5 cm in the peripheral belt up to 10-12 cm in the central area, where an irregular pit including thermally altered pebbles (often characterised by blackish coatings) was identified (su14). as a whole, this escargotière has known various phases of accumulation. it seems to be formed by numerous lenticular layers with limited lateral extension. data collected lead to interpret it as an anthropogenic accumulation formed by the disposal of processing materials and meal wastes. particularly relevant among the latter are bone remains that present a better degree of preservation than the other excavation sectors. this is probably connected to the shells' presence, which tempered the action of degradation of the soil. among the bone remains, it is worth noting numerous teeth and jaws. the second shell-rich layer (su17) was identified below the large combustion feature f4 (fig. 8c). it has an extension of 1.5 square meters and a thickness of ca. 5 cm. although being more limited, this unit retains the same characteristics as su10, being formed by shells of helix cf. pomatella, lithic artefacts, bone remains, burnt clayey chips, charcoal, and small centimetric limestone pebbles. the escargotière is connected to a small pit (su20) that shows traces of thermal alteration, although being a natural depression and not an intentionally dug feature like in the case of su14 (fig. 8d). a perforated columbella rustica shell was also identified within the filling of this latter feature. the lower part of the thin section mm17 shows the shell-rich layer su10 (fig. 9a). the dominant fine groundmass comprises microfaunal faecal pellets organised in porous spheroidal crumbs. shells are mainly intact, planarly arranged, and loosely packed, testifying to the absence of trampling (fig. 9b-c). the comparison with experimental data on molluscs subjected to various temperatures (canti, 2017) shows that the birefringence degree is compatible with a 30 minute exposure to a 200° heating source. within the matrix of su3, fish bones were also identified. in particular, two vertebrae 55 a new early holocene site in central italy: contrada pace fig. 7 a) macrograph of thin section mm9 (combustion feature f3) and interpretation. su9: mesolithic buried soil. cs 1: combustion substrate at the top of su9. the sediment is dark in colour due to the presence of fine organic matter that became charred in place; orange: isolated rubified aggregates of the combustion substrate (cs2) su15; su3: post-occupation buried soil; ch: channel; co: carbonate concretion. rectangles indicate micrographs b and c. b) micrograph with isolated rubified granular aggregate (ppl, plane-polarised light); c) micrograph of carbonate concretion with a "ghost" of plant remains (xpl, cross-polarised light). for a detailed description, see appendix c. 56 visentin d. et al. occupation of the area as the filling was pedogenised. the distribution of the archaeological findings inside the depression suggests that it was already almost levelled. the second feature (c9) results from the falling of a large tree whose roots left a 4 metres large hole on the ground. the distribution of the tilted sediments and the orientation of the depression indicate that the tree fell north-eastward, in the direction of the first-mentioned tree-hole and the combustion structure. archaeological findings were identified inside the backward depression formed by the tree thrown, indicating that the falling preceded the occupation of the area. nonetheless, in this latter case, it had not started to fill, and it is thus supposed to be much more recent than the other. in thin section mm15 (fig. 11a), the charcoal-rich layer named su11 is visible above the silty-clay loam that composes su9. su11 has an average thickness of around 1-to-1.5 cm and is characterised by a high presence of charcoal fragments (fig. 11b), as large as 18 mm. large pieces of charcoal and burnt vegetable fibres aligned and fragmented in situ, particularly abundant in the top portion of the soil, may indicate the use of fire for clearing the area. vesicular porosity of su9 can be related to trampling in over-saturated conditions due to the presence of water. charcoal fragments show a welldeveloped in situ disaggregation. the holes produced by the fragmentation of charcoal pieces were later filled in by illuvial clay. clay accumulation is favoured by an alkaline and potassium-rich environment derived from the presence of abundant ash. this latter was not preserved in the sediment because of the rapid chemical dissolution in sub-aerial or acid conditions (huismann et al., 2012). rare mollusc shells (fig. 11c) are attested within su11 and su3. 6. the main escargotière (su10): carpological, malacological and zooarchaeological analyses 6.1. carpological remains overall, 189 carpological remains were found within the sediment of su10 (tab. 2). most of the macroremains are in a carbonised state (c); carbonisation results from contact with a heat source. some finds are found in a mineralised state (m); the mineralisation is instead due to the transformation of the organic substance into calcium phosphate. no carpological remains were identified in four squares: e21, g20, i21, and i22. in the northern area of the stratigraphic unit, finds are more concentrated. 13% of the finds (28 macroremains, fig. 12, 13) include small fragments of hazelnut stones. after the end of the great glacial impulses, hazel spread into deciduous and coniferous forests and wooded margin areas. it is a plant that grows from the plain to the mountain and subalpine belt, is a pioneer of the forest, fig. 8 the two escargotières uncovered at cp1. a) the largest one named su10; b) detail of su10 showing the density of archaeological findings; c) the second escargotière named su17, which was partially covered by combustion feature f4; d) after the removal of su17 another oxidised surface appeared in correspondence of combustion feature f4. and is easy to propagate (pignatti, 2017). hazel is one of the spontaneous plants that continued to be used even in post-domestication phases, thus tracing a continuity through a period of relevant changes in the subsistence economy (rottoli, 2002). the blackthorn (cf. prunus sp. l.) and the chinese lantern (physalis alkekengi l.) are the other two edible fruits found in the studied samples. only four stone fragments almost certainly referred to blackthorn were found in square g24. blackthorn is also well represented in other european mesolithic contexts, such as in greece (kotzamani & livarda, 2018), czech republic (divišováa & šídaa, 2015), serbia (marinova et al., 2013), and southeastern france (henry et al., 2011), often documented both by stone fragments and anthracological remains. a single fragment of chinese lantern seed has been identified in square i20, although other finds have also been recognised in other stratigraphic units not included in this work. based on archaeological data, the consumption of this fruit is first attested in the mesolithic and continued throughout the neolithic in italy and southern europe (marinova et al., 2013; carra, 2014). 17% of the finds (36 fragments distributed in 8 squares) concerns macroremains attributable to fragments of the pulp of fleshy fruits, in which part of the peel (epicarp) is still visible. although it is impossible to identify the type of plant, these fragments are probably related to peduncles and cicatrix, which attest to the elements connecting the fruit to the plant. the presence of other fruits, even if not determinable, confirms the picking of edible plant elements by the groups who settled at contrada pace. eleven remains were determined as sclerotia and were mainly found in the eastern squares (j19-22 and j24). sclerotia are hibernating mycelial bodies, i.e., aggregates of fungal hyphae that form a coating called pseudo parenchyma. this protective shell allows them to persist for a long time in the soil. sclerotia often fossilise and can be found in archaeological sediments. sclerotia can form as pathogens in the ears of cereals, of which claviceps purpurea is probably the best known. it causes ergot disease but is also used for healing purposes. its stride shape does not correspond to the finds from contrada pace, which are instead spherical in shape and smaller in size. our macroremains are related to different types of hypogeal ectomycorrhizal fungi (symbiotic fungi of the root system of other vascular plants), which form associations with various types of tree plants (musmarra, 1996). a more significant presence of sclerotia in the northern sector of the squares examined could reveal the proximity to roots not identified during the excavation phase. the uses of these types of sclerotia are not known. also, some fragments of seeds and fruits of herbaceous plants have been found: carex sp. (h19), cf. carex sp. (d22), cf. paris quadrifolia (g24), cf. chaenorhinum sp. (d22, g24), cf. rumex sp. (i18). these species were widespread in the ancient environment. some of them may have also been used: the sedge stem (carex) for intertwining (e.g., basketry and cordage), the dock (rumex) as plant food, and paris quadrifolia as a medicinal narcotic and poisonous plant (guarino et al., 2008). the small number of finds does not allow us to support these hypotheses further. the identification of two achenes (one carbonised and one mineralised) was only possible to the botanical 57 a new early holocene site in central italy: contrada pace fig. 9 a) macrograph of thin section mm17 and interpretation. su10: escargotière; su3: post-occupation buried soil; green dotted line: top of escargotière (su10); s: mollusc shell. rectangles indicate micrographs b, c, d, and e. b) planarly arranged and loosely packed shells (ppl, plane-polarised light). c) gastropod shell (ppl, planepolarised light). d) a fish scale with the typical denticulated edge (xpl, cross-polarised light). e) transversal cut of a fish vertebra (ppl, plane-polarised light). for a detailed family, lamiaceae (g24) and asteraceae (d22); three fragments are attributable to wild poaceae caryopsis (f20, g21, g23). the lack of specific determination does not allow us to hypothesise other uses for these macroremains; their distribution in the excavation squares appears completely random. finally, 91 remains (43%) are fragmentary and indeterminable. the absence of ornamentation and the small size do not allow further identification. the indeterminate fragments are numerous and homogeneously distributed in almost all the examined squares, but they do not add information to the carpological complex. 6.2. faunal remains a total of 306 bone fragments were recovered in su10. the frequency of determinable elements is relatively low as only 16.3% (50) of them were determined taxonomically and anatomically, while indeterminate findings represent the remaining 83.7% (256). the fauna from this unit is composed of three main species: two ungulates, roe deer (capreolus capreolus) and wild boar (sus scrofa), and one carnivore, fox (vulpes vulpes)(fig. 14). the roe deer is the most represented mammal (nr 44), followed by the wild boar (nr 5) and the fox (nr 1) (tab. 3). 58 visentin d. et al. fig. 10 planimetric map showing the relationship between the charcoal-rich layer called su11 and the surrounding features. of roe deer remains (tab. 4), teeth are the most attested anatomical portion (nr 27); there are also a few cranial fragments, three vertebrae, some fragments of appendicular skeleton consisting of fragments of phalanx, carpus-tarsus, metapodials and a single fragment of limb (distal portion of a tibia). wild boar is represented by five elements (tab. 4): three teeth (an upper female canine, an upper left premolar and a fragment of a tooth crown), a fragment of the proximal diaphysis of the humerus and a maxilla of a young male individual. regarding the fox, this species is represented by a single remain: a first lower molar. from the analysis of dental eruption, it was possible to identify the minimum number of individuals present in su10: roe deer, once again, is the most represented animal with six individuals; for wild boar, three individuals have been identified and only one individual for fox. from the study of the teeth, it was possible to obtain information about the likely age of death of the animals. this evaluation was carried out only for roe deer and wild boar; the molar of the fox had no diagnostic features regarding age. thanks to the comparison with the tables of tomè & vigne (1999) and mustoni et al. (2002), five different adult age groups were recognised for roe deer (tab. 5). no remains of very young individuals were identified, and all the analysed remains belong to individuals who had erupted the third molar at the time of death. with the use of the tables proposed by grant (1982), it was possible to identify the age of death of two boar individuals. both the upper left premolar and the maxilla of the male boar belong to young individuals. regarding the taphonomic analysis, it was impossible to observe anthropogenic or natural traces other than those connected to weathering. all the materials were strongly compromised by the combined action of temperature and humidity that caused deep cracks in the bone matrix and extensive exfoliation of the cortical surfaces preventing any other observation and further analyses. 6.3. malacological remains malacological remains recovered within stratigraphic unit 10 are particularly abundant. during sediment processing, 6741 specimens were individually collected (tab. 6). other microscopic specimens recovered with floatation residue are still under study and are not included in this work. the assemblage comprises 18 different species and is partly the result of a natural thanatocoenosis, partly the collection and discard of mollusc shells by the mesolithic hunter-gatherers that inhabited the site. the anthropogenic collection was aimed at a single species (helix cf. pomatella) and probably took place in the site surroundings. for this species, a mni of 3754 specimens was calculated. among these, 1500 shells are complete and could be analysed from a dimensional and traceological viewpoint. shell diameter is between 21 and 29 mm (average value: 24.03 mm) and height between 20 and 29 (average value: 25.28 mm). they all belong to adult or almost adult individuals (fig. 15). this indicates that collected specimens were carefully selected according to their dimensions. it is also interesting to note that other edible species were attested in the area and the archaeological record (e.g., cepaea nemoralis) but were not the object of dedicated collection. the absence of macroscopically visible thermal alterations suggests that the gastropods were cooked without direct contact with the heating source (mussi et al., 2004; bisegna et al., 2011), as also testified by thin section analysis (cf. §5.2). furthermore, shells do not present any evidence referable to their perforation or fracture connected to the extraction of the mollusc. all the other species attested within su10 belong to local coenosis and thus offer useful information on palaeoenvironment. the assemblage is dominated by pomatia elegans, a gastropod typical of mesophilic environments. additionally, numerous nemoral molluscs and micromolluscs occur: clausilia cruciata, macrogastra attenuata, discus rotundatus, sphyradium doliolum, vitrea diaphana, and punctum pygmaeum. on the other hand, xerophilous and meso-xerophilous species are 59 a new early holocene site in central italy: contrada pace fig. 11 a) macrograph of thin section mm15 and interpretation. su9: mesolithic buried soil; su11: fragmented charcoal in the surface horizon of enclosed space; su3: postoccupation buried soil; c: charcoal; s: mollusc shell (su3); v: vesicular porosity; co: carbonate concretion. rectangles indicate micrographs b and c. b) large charcoal fragment (ppl, plane-polarised light); c) mollusc shell (ppl, plane-polarised light). for a detailed description, see appendix c. 60 visentin d. et al. t ab . 2 t he d et er m in at io n of c ar po lo gi ca l r em ai ns o f s u 10 . s am pl es c or re sp on d to th e en tir e s u 10 s ed im en t o f e ac h sq ua re . represented by a marginal number of specimens. among them, the most numerous is rumina decollata, an omnivorous species. since it is a predator of other molluscs, it was likely drawn to the site by the abundance of trophic resources connected to the presence of food wastes. 7. discussion and conclusions the excavation at contrada pace undoubtedly yielded one of the richest and best-preserved open-air early mesolithic sites in italy and, more generally, in southern europe. although postexcavation analyses are still in an initial state, the first data and results allowed to obtain insight into the lifeways of the hunter-gatherers who occupied the area. the large terrace formed by the chienti river during the final pleistocene was perceived as a landmark within the territory. it was repeatedly occupied during the early holocene, as testified by the first radiocarbon dates and the vast surface (stretching at least 500 m) that yielded similar early mesolithic evidence. in addition to the archaeological evidence, the radiocarbon dataset of contrada pace furtherly confirms that the aggradation of the alluvial plain ended after the very beginning of the holocene. it thus predates the incision of the braid-plain and the correlated formation of this and possibly other terraces short after 9800 cal bp, i.e., earlier than previously thought for other rivers of the marche region (cilla et al., 1996). unfortunately, the absence of contemporary evidence in the region does not allow us to comprehend the role of contrada pace on a territorial scale. based on comparisons with northern areas (fontana & visentin, 2016), the working hypothesis is that the site could represent an intermediate seasonal settlement area located between the adriatic shore and the central apennines uplands. in the main site (cp1), multiple scatters of lithic artefacts resulting from both primary (e.g., knapping and domestic activities) and secondary (e.g., dumping) actions were brought to light. the microlithic elements with geometric (triangles, crescents) and needle-like shapes 61 a new early holocene site in central italy: contrada pace fig. 13 carpological remains found in the various squares of su10: fruit fragment (a); corylus avellana (b); carex sp. (c); cf. chaenorhinum sp. (d); cf. paris quadrifolia (e); peduncle/cicatrix (f); fragment of poaceae grain (g); fragment of cf. prunus sp. stone (h). fig. 12 total statistical incidence of carpological remains. found, the barrier-effect influencing the distribution of charcoal remains suggests the existence of a wall or fence made of perishable material. possibly, it represented a sort of hut made by exploiting the trunk of the surrounding trees. this is a working hypothesis based on field-collected data that will have to be confirmed with the prosecution of spatial and micromorphological analyses. other examples concerning the exploitation of felled trees were recently brought to light in other late palaeolithic and mesolithic sites discovered in the alpine area (mottes et al., 2018). of the five combustion features identified, the simplest type is represented by open hearths lighted directly (double-backed points, cf. sauveterre) typical of the early phase of the mesolithic (i.e., sauveterrian; visentin, 2018) are frequent. nevertheless, radiometric evidence already pointed out that not all anthropogenic features are coeval: the samples from the sheltered area (su11 and su15) provided very similar ages, confirming the stratigraphic relationship between the two units. conversely, the sample from the shell-rich layer su10 returned a 500 years older radiocarbon age, documenting a previous occupational phase of the site. a systematic dating plan is required to sort the entire evidence by chronology, a task that will be carried out shortly. one of the most interesting aspects of the site is the relationship between archaeological evidence and tree stumps, as these latter seem to represent hotspots for human activities up to the point that tree throws were used to build both sheltered and enclosed spaces. stratigraphic unit 11 and related features represent the best example of this behaviour. their overall distribution suggests that this area had been arranged and that mesolithic huntergatherers exploited the particular conformation of trees and tilted tree stumps for their needs. although no post-hole was 62 visentin d. et al. tab. 3 quantification of species according to the number of remains (nisp) and the minimum number of individuals (mni). fig. 14 some faunal remains from su10 of contrada pace. a. right lower third molar of capreolus capreolus; b. distal portion of left tibia of capreolus capreolus; c. left lower first molar of vulpes vulpes; d. upper canine of a female sus scrofa. on the soil surface. in other cases, a relieved burning surface was created by laying a layer of clayey sediment on the grass. with the first uses of the fire, such accumulation hardens and becomes an efficient surface for burning and cooking. variations in the form and type of the hearths over the investigated area seem to reflect changes in the functional destination of the combustion features or changes in the kind of occupation. as for the combustion features with a prepared burning surface, few comparisons can be found in other mesolithic sites. at duvensee wp11 in germany, a clay plate was found within an early mesolithic layer (lage, 2011), although its interpretation is still discussed. the closest reference is probably represented by the uzzo cave in sicily (tagliacozzo & piperno, 1993), where a 50 cm wide and 2-3 cm thick clay plate was found in association with an early mesolithic palaeosurface characterised by abundant combustion traces and several lithic artefacts, faunal and malacological remains (both marine and terrestrial). additionally, two negative features, both connected to the escargotières, are considered combustion features possibly related to cooking activities, as suggested by the presence of heated pebbles. one thing that particularly stands out in the contrada pace site is the large escargotière named su10, totalling a large number of edible specimens (over 3700). mollusc shells are associated with a very high quantity of archaeological materials, allowing us to interpret them as the result of an anthropogenic accumulation. this is also supported by microscopic alterations of the shell structure, indicating that the molluscs were cooked at low temperatures for a short time and not roasted. direct contact with fire or burning charcoal would have led to a much more severe alteration of the surfaces and internal structures. finally, helix cf. pomatella is not a gregarious species, so the possibility of natural accumulations can be undoubtedly excluded. numerous examples of escargotières dated between the late pleistocene and the holocene are known from various archaeological contexts of the circummediterranean area, in particular from sites of north africa, the iberian peninsula, the pyrenees, and the near east (a synthesis in lubell, 2004). despite this, similar evidence is by no means common in italy, where the importance of terrestrial molluscs as a food resource needs to be better defined and understood (girod, 2011). examples of land snails accumulations are documented in the mesolithic levels at the inland sites of grotta di pozzo (mussi et al., 1995; lubell et al., 1999) and grotta continenza (bevilacqua, 1994) in the fucino basin and a few cave contexts in the trieste karst area (cannarella & cremonesi, 1967; cremonesi, 1967). some other evidence is known from late pleistocene/ early holocene sites on the tyrrhenian coast and south italy, where shell-rich deposits containing marine and terrestrial molluscs have been reported (girod, 2011; mussi et al., 1995 and reference therein). nonetheless, the character of such finds and their role in the human diet remains to be better defined. the clayey sediment of su10 also favoured the preservation of carpological findings. a rich assemblage of organic remains was recovered during floatation. the identified carpological finds, among which hazelnuts, blackthorns and chinese lanterns, are well framed within the southern european mesolithic (costantini, 1981; lubell et al., 1999; leoni et al., 2002; holst, 2010; regnell, 2012; bishop et al., 2014; divišováa & šídaa, 2015; mariotti lippi et al., 2016), although in other cases, like for example at franchthi cave (asouti et al., 2018), the selection of plant foods seems more oriented towards spontaneous pulses and grasses. indeed, the research progress, including ongoing analyses of the archaeological materials from the other stratigraphic units, will bring about new data on the exploitation of plants at contrada pace. another important goal will be to establish the role of plant resources in the site economy, which will only be possible at the end of the analysis of the entire archaeological deposit. regarding the faunal remains, the soil chemistry did not allow for optimal preservation of the assemblage. 63 a new early holocene site in central italy: contrada pace tab. 4 summary table of taxa divided by anatomical elements. tab. 5 age groups recognised for roe deer. only three species are attested among the determined specimens in su10: two ungulates (wild boar and roe deer) and a carnivore (fox). however, the ongoing study of the faunal remains from the other stratigraphic units has highlighted the presence of other species, such as red deer. these are all animals typical of forested environments, such as those that characterised the italian peninsula in the early holocene. the discovery of hundreds of bone fragments belonging to different mammal species confirms the importance of hunting for the subsistence of the mesolithic groups of contrada pace and the harvesting of terrestrial molluscs and wild vegetables and fruits. by continuing to process the sediment collected during the excavation and proceeding with laboratory analysis of the archaeological findings and samples, it will be possible to deepen the study of the site and better understand its spatial organisation and function and reconstruct its formation processes. the evidence collected at contrada pace will undoubtedly represent a significant reference for studying the lifeways of the last european hunter-gatherer groups in this part of the southern regions of the continent. author contributions conceptualisation: d. visentin, a. potì, f. fontana, m. peresani; original draft: a. potì, d. visentin, m. bassetti, s. bertola, m. carra, e. cristiani, n. dipino, a. fontana, m. palmieri, m. peresani; archaeological excavation: a. d'ulizia, a. potì, d. visentin, g. cattabriga, a. cocilova, n. fasser, direction of archaeological excavation: s. finocchi; p. mazzieri; archaeo-pedologic description and micromorphological analysis: m. bassetti; carpological analysis: m. carra; study of faunal assemblages: n. dipino, a. fontana; malacological analysis: m. palmieri; review and editing: all authors. acknowledgements the archaeological excavation of the site was carried out by archeolab (macerata, italy) in the framework of construction activities promoted by the province of macerata and the municipality of tolentino. dv has received funding from the european union's horizon 2020 research and innovation programme (grant agreement number: 886476 limph h2020-msca-if2019). the archaeobotanical study and 14c dates were funded by the european research council (erc) as part of the research and innovation program of the european community horizon 2020 (hidden foods no.639286 to ec). the authors wish to thank giordano pierucci for his constant support and enthusiasm. we are also grateful to the two anonymous reviewers and the editor, whose useful comments allowed improving the manuscript. references aldeias v., dibble h.l., sandgathe d., goldberg p., mcpherron s.j.p. (2016) how heat alters underlying deposits and implications for archaeological fire features: a controlled experiment. journal of archaeological science, 67, 64-79. doi: 10.1016/j.jas.2016.01.016 amiel c., lelouvier l.-a. (2003) gisements postglaciaires en bas-quercy. aep/centre d’anthropologie et inrap, toulouse, pp. 205. asouti e., ntinou m., kabukcu c. (2018) the impact of environmental change on palaeolithic and mesolithic plant use and the transition to agriculture at franchthi cave, greece. plosone, 13(11), e0207805. doi: 10.1371/journal.pone.0207805 bagolini b., dalmeri g. (1987) i siti mesolitici del colbricon (trentino). analisi spaziale e fruizione del territorio. preistoria alpina, 23, 7-188. baroni c., biagi p. (1997) excavations at high altitude 64 visentin d. et al. fig. 15 archaeological specimens of helix cf. pomatella belonging to su10. tab. 6 malacological remains identified within su10. mesolithic site of laghetti del crestoso (bovegno, brescia northern italy). ateneo di brescia. accademia di scienze lettere ed arti, pp. 109. bevilacqua r. (1994) la grotta continenza di trasacco. i livelli mesolitici ed epigravettiani. rivista di scienze preistoriche, xlvi, 3-39. bishop r.r., church m.j., rowley-conwy p.a. (2014) seeds, fruits and nuts in the scottish mesolithic. proceedings of the society of antiquaries of scotland, 143, 9-72. bisegna a., d’angelo e., gioia p., mussi m. (2011) raccolta e cottura delle lumache in abruzzo: preistoria e attualità. in: lugli f., stoppiello a.a., biagetti s. (eds.), atti del 4° convegno nazionale di etnoarcheologia (roma 17-19 maggio 2006). archaeopress, oxford, 95-101. bonsall c., boroneant a. (2018) the iron gates mesolithic a brief review of recent developments. l’anthropologie, 122, 2, 264-280. boric d., french c.a.i., stefanovic s., dimitrijevic v., cristiani e., gurova m., antonovic d., allué e., filipovic d. (2014) late mesolithic lifeways and deathways at vlasac (serbia). journal of field archaeology, 39, 1, 4-31. broglio a. (1972) i più antichi abitatori della valle dell’adige, preistoria alpina, 8, 157-176. broglio a. (1992) mountain sites in the context of north -east italian upper palaeolithic and mesolithic, preistoria alpina, 28, 1, 293-310. bronk ramsey c. (2021) oxcal 4.4. available at: http://c14.arch.ox.ac.uk/oxcal. calderoni g., coltorti m., dramis f., magnatti m., cilla g. (1991) sedimentazione fluviale e variazioni climatiche nell’alto bacino del fiume esino durante il pleistocene superiore. in: fenomeni di erosione e alluvionamento degli alvei fluviali (ed. by tazioli s.). dipartimento di scienze dei materiali e della terra, università di ancona, ancona, 171-190. cannarella d., cremonesi g. (1967) gli scavi nella grotta azzurra di samatorza nel carso triestino, “rivista di scienze preistoriche”, xxii, 281-330. canti m.g. (2017) burnt carbonates. in: archaeological soil and sediments micromorphology (ed. by nicosia c., stoops g.). john wiley & sons, chicester, 181-188. cappers r.t.j., bekker r.m., jans j.e.a. (2012) digital seed atlas of the netherlands. barkhuis ed., netherlands, pp. 502. carra m. (2014) i macroresti vegetali dal sito di ponte ghiara (pr): considerazioni paleo-ecologiche e paleo-economiche. atti del convegno “il pieno sviluppo del neolitico in italia”, finale ligure, 8-10 giugno 2009, rivista di studi liguri, lxxvii-lxxix (2011-2013), 71-78. cilla g., coltorti m., dramis f. (1994) holocene fluvial dynamics in the mountain areas: the case of the esino river (umbro-marchean apennine). geografia fisica dinamica quaternaria, 17, 163-174. cilla g., coltorti m., farabollini p., dramis f., gentili b., pambianchi g. (1996) fluvial sedimentation in the early holocene in the marchean valley (central italy). il quaternario, 9(2), 459-464. coltorti m., consoli m., dramis f., gentili b., pambianchi g. (1991) evoluzione geomorfologica delle piane alluvionali delle marche centromeridionali. geografia fisica dinamica quaternaria, 14(1), 87-100. coltorti m., farabollini p. (2008) late pleistocene and holocene fluvial-coastal evolution of an uplifting area: the tronto river (central eastern italy). quaternary international, 189, 39-55. costantini l. (1981) semi e carboni del mesolitico e neolitico della grotta dell’uzzo, trapani. quaternaria, 23, 233-247. courty m.a., carbonell e., vallverdú-poch j., banerjea r. (2012) microstratigraphic and multi-analytical evidence for advanced neanderthal pyrotechnology at abric romani (capellades, spain). quaternary international, 247, 294-312. coutard s., ducrocq t., limondin-lozouet n., bridault a., leroyer c., allenet g., pastre j.-f. (2010) contexte géomorphologique, chronostratigraphique et paléoenvironnemental des sites mésolithiques et paléolithiques de warluis dans la vallée du thérain (oise, france). quaternaire, 21(4), 357 -384. doi: 10.4000/quaternaire.5702 cremonesi g. (1967) gli scavi nella grotta della tartaruga presso borgo grotta nel carso triestino, relazione preliminare. atti della società toscana di scienze naturali, 74, 430-443. cristiani e. (2009) osseous artefacts from the mesolithic levels of pradestel rock-shelter, (northeastern italy): a morphological and technofunctional analysis. preistoria alpina, 44, 181-205. cusinato a., dalmeri g., fontana f., guerreschi a., peresani m. (2003) il versante meridionale delle alpi durante il tardiglaciale e l’olocene antico: mobilità, sfruttamento delle risorse e modalità insediative degli ultimi cacciatori-raccoglitori, preistoria alpina, 39, 129-42. divišováa m., šídaa p. (2015) plant use in the mesolithic period. archaeobotanical data from the czech republic in a european context a review. interdisciplinaria archaeologica, natural sciences in archaeology, vi, 1, 95-106. fao (2006) guidelines for soil description, fourth ed. fao, food and agriculture organization of the united nations, rome. fiorentino v., manganelli g., giusti f., ketmaier v. (2016) recent expansion and relic survival: phylogeography of the land snail genus helix (mollusca, gastropoda) from south to north europe. molecular phylogenetics and evolution, 98, 358-372. fontana f., guerreschi a. (2009) variability of lithic resource exploitation systems in northern italy during the early holocene: the case-studies of mondeval de sora (belluno) and i.n.f.s. (bologna). in: mesolithic horizons, vol. 2 (ed. by mccartan s.b., schulting r., warren g., woodman p.). oxbow books, oxford, 802-810. fontana f., visentin d. (2016) between the venetian alps and the emilian apennines (northern italy): highland vs. lowland occupation in the early mesolithic. quaternary international, 423, 266-278. 65 a new early holocene site in central italy: contrada pace doi:10.1016/j.quaint.2015.12.014. fontana f., vullo n. (2000) organisation et fonction d’un camp de base saisonnier au cœur des dolomites: le gisement mésolithique de mondeval de sora (belluno, italie). in: les derniers chasseurscueilleurs d’europe occidentale (ed. by richard a., cupillard c., richard h., thévenin a.). annales littéraires, 699, environnement, sociétés et archéologie, 1, 197-208. fontana f., guerreschi a., peresani m. (2011) the visible landscape. inferring mesolithic settlement dynamics from multifaceted evidence in the southeastern alps. in: hidden landscapes of mediterranean europe, proceeding of the international conference, siena, 2007 (ed. by van leusen m., pizziolo g., sarti l.). bar international series 2320, bar publishing, oxford, 71-81. fontana f., visentin d., wierer u. (2016) mesolife. a mesolithic perspective on alpine and neighbouring territories. quaternary international, 423, 1-4. doi: 10.1016/j.quaint.2016.06.016 friesem d.e., zaidner y., shahack gross r. (2014) formation processes and combustion features at the lower layers of the middle palaeolithic open air site of nesher ramla, israel. quaternary international, 331, 128-138. gazzoni v., goude g., dalmeri g., guerreschi a., mottes e., nicolis f., antonioli f., fontana f. (2021) investigating the diet of mesolithic groups in the southern alps: an attempt using stable carbon and nitrogen isotope analyses. bulletins et mémoires de la société d’anthropologie de paris, 33, 1. doi: 10.4000/bmsap.7518 girod a. (2011) land snails from late glacial and early holocene italian sites. quaternary international, 244, 105-116. grant a. (1982) the use of tooth wear as a guide to the age of domestic ungulates. in: ageing and sexing animal bones from archaeological sites (ed. by wilson b., grigson c., payne s.). bar british series 109, bar publishing, oxford, 91108. grayson d.k. (1984) quantitative zooarchaeology. topics in the analysis of archaeological faunas. academic press, new york, pp. 202. guarino c., de simone l., santoro s. (2008) ethnobotanical study of the sannio area, campania, southern italy. ethnobotany research & applications, 6, 255-317. habermehl k.h. (1961) die altersbestimmung bei haustieren, pelztieren und beim jagdbaren wild. paul parey verlag, berlin. henry a., bouby l., valdeyron n. (2011) environment and plant economy during the mesolithic in the haut-quercy (lot, france): anthracological and carpological data. sagvntvm, 5th international meeting of charcoal analysis, valencia, spain, september 5th-9th 2011, 79-80. holst d. (2010) hazelnut economy of early holocene hunter-gatherers: a case study from mesolithic duvensee, northern germany. journal of archaeological science, 37, 2871-2880. huismann d.j., braadbaart f., van wijk i.m. (2012) ashes to ashes, charcoal to dust: micromorphological evidence for ash induced disintegration of charcoal in early neolithic (lbk) soil features in elsloo (the netherlands). journal of archaeological science, 39, 994-1004. iuss working group wrb (2015) world reference base for soil resources 2014, update 2015. international soil classification system for naming soils and creating legends for soil maps. world soil resources reports, 106, fao, rome. kerney m.p., cameron r.a.d. (1999) guide des escargots et limaces d’europe. delachaux et niestlé. lausanne, pp. 372. kind c.j. (2013) tiny stones in the mud. the mesolithic sites of siebenlinden (rottenburg, badenwürttemberg, south west germany). in: mesolithic palethnography. research on open-air sites between loire and neckar. proceedings from the international round-table meeting, paris, november 26-27, 2010 (séances de la société préhistorique française 2-2) (ed. by valentin b., souffi b., ducrocq t., fagnart j.-p., séara f., verjux c.). société préhistorique française, 251-266. kompatscher k., hrozny kompatscher n., bassetti m., castiglioni e., rottoli m., wierer u. (2016) mesolithic settlement and mobility patterns at high altitudes. the site of staller sattel sts 4a (south tyrol, italy). quaternary international, 423, 23-48. doi: 10.1016/j.quaint.2015.12.090. kotzamani g., livarda a. (2018) people and plant entanglements at the dawn of agricultural practice in greece. an analysis of the mesolithic and early neolithic archaeobotanical remains. quaternary international, 496, 80-101. doi: 10.1016/j.quaint.2018.04.044. lage w. (2011) experimental archaeological exploration of mesolithic techniques for hazelnut roasting. schriften des naturwissenschaftlichen vereins für schleswig-holstein, 73, 12-22. leoni l., castelletti l., castiglioni e. (2002) i carboni epigravettiani e mesolitici e la dinamica della copertura forestale a isola santa. rivista di scienze preistoriche, 52, 183-195. lipparini t. (1939) i terrazzi fluviali delle marche. giornale di geologia, 13, 5-22. lo vetro d., martini f. (2016) mesolithic in centralsouthern italy: overview of lithic productions. quaternary international, 423, 279-302. lyman r.l. (1994) quantitative units and terminology in zooarchaeology. american antiquity, 59, 36-71. lubell d., mussi m., musacchio a., agostini s., coubray s., giraudi c. (1999) exploitation of seasonal resources in the mountains of abruzzo (central italy): epigravettian to neolithic. in: l’europe des derniers chas-seurs. epipaléolithique et mésolithique (ed. by thévenin a.). 5° congrès uispp, paris 1998, 465-472. lubell d. (2004) prehistoric edible land snails in the circum-mediterranean: the archaeological evidence. in: petits animaux et sociétés humaines. du complément alimentaire aux resources utilitaires (ed. by brugal j.j., desse j.). éditions 66 visentin d. et al. apdca, antibes, 41-62. mallol c., hernandez c., cabanes d. (2013) the black layer of middle palaeolithic combustion structures. interpretation and archaeostratigraphic implications. journal of archaeological science, 40, 2515 -2537. mallol c., mentzer s.m., miller c.e. (2017) combustion features. in: archaeological soil and sediments micromorphology (ed. by nicosia c., stoops g.). john wiley & sons, chicester, 299-330. marinova e.m., filipović d., obradović d., allué e. (2013) wild plant resources and land use in mesolithic and early neolithic south-east europe. archaeobotanical evidence from the danube catchment of bulgaria and serbia. offa, 69, 467478. mariotti lippi m., bandini mazzanti m., bosi g., buonincontri m., castiglioni e., di pasquale g., giardini m., marchesini m., miola a., montanari c., rottoli m., sadori l., mercuri a.m. (2016) archeobotanica. in: la storia delle piante fossili in italia (ed. by kustatscher e., roghi g., bertini a., miola a.). pubblicazione del museo di scienze naturali dell’alto adige, 9, 346-391. martínez-moreno j., mora torcal r. (2011) spatial organisation at font del ros, a mesolithic settlement in the south-eastern pyrenees. in: siteinternal spatial organization of hunter-gatherer societies: case studies from the european palaeolithic and mesolithic (ed. by gaudzinskiwindheuser s., sensburg m., street m., turner e.). verlag des römisch-germanischen zentralmuseums, mainz, 213-231. martini f. (2006) il mesolitico di pieve torina. in: preistoria e protostoria delle marche. atti della xxxviii riunione scientifica. portonovo, 1-5 ottobre 2003, vol. 1. istituto italiano di preistoria e protostoria, firenze, 173-188. mordant, d., valentin, b., vigne j.-d. (2013) noyensur-seine, twenty-five years on. in: mesolithic palethnography. research on open-air sites between loire and neckar. proceedings from the international round-table meeting, paris, november 26-27, 2010 (séances de la société préhistorique française 2-2) (ed. by valentin b., souffi b., ducrocq t., fagnart j.-p., séara f., verjux c.). société préhistorique française, paris, 37-49. mottes e., bassetti m., avanzini m., boschin f., cremona m.g., cottini m., dalmeri g., festi d., fontana f., oeggl k., rottoli m. (2018) tra la foresta e il lago. il sito all'aperto dell’epigravettiano recente di arco via serafini (trento, italia settentrionale). annali dell’università degli studi di ferrara, museologia scientifica e naturalistica 13, 2023. doi: 10.15160/1824-2707/1561 murphy c.p. (1986) thin section preparation of soils and sediments. ab academic publishers, berkhamsted, pp.149. musmarra a. (1996) dizionario di botanica. edagricole, bologna, pp.1182. mussi m., d’angelo e., fiore i. (2004) escargots et autres «petites» ressources alimentaires: le cas de la grotta di pozzo (abruzzes, italie centrale). in: petits animaux et sociétés humaines. du complément alimentaire aux resources utilitaires (actes des xxiv rencontres internationales d'archéologie et d’histoire d’antibes) (ed. by brugal j.p., desse j.). apdca, antibes, 99-109. mussi m., lubell d., arnoldus-huyzendveld a., agostini s., coubray s. (1995) holocene land snail exploitation in the highlands of central italy and eastern algeria: a comparison. préhistoire européenne, 7, 169-189. mustoni a., pedrotti l., zanon e., tosi g. (2002) ungulati delle alpi. biologia, riconoscimento, gestione. nitida immagine editrice, cles, pp.539. nicosia c., stoops g. (2017) archaeological soil and sediment micromorphology, wiley blackwell, chichester. peresani m., monegato g., ravazzi c., bertola s., margaritora d., breda m., fontana a., fontana f., janković i., karavanić i., komšo d., mozzi p., pini r., furlanetto g., de amicis m.g., perhoč z., posth c., ronchi l., rossato s., vukosavljević, n., zerboni a. (2021) hunter-gatherers across the great adriatic-po region during the last glacial maximum: environmental and cultural dynamics. quaternary international, 581-582, 128-163. doi: 10.1016/j.quaint.2020.10.007 pignatti s. (2017) flora d’italia. 4 vol. edagricole, bologna, pp. 4584. regnell m. (2012) plant subsistence and environment at the mesolithic site tågerup, southern sweden: new insights on the "nut age". vegetation history and archaeobotany, 21(1), 1-16. reimer p.j., austin w.e.n., bard e., bayliss a., blackwell p.g., bronk ramsey c., butzin m., cheng h., edwards r.l., friedrich m., grootes p.m., guilderson t.p., hajdas i., heaton t.j., hogg a.g., hughen k.a., kromer b., manning s.w., muscheler r., palmer j.g., pearson c., van der plicht j., reimer r.w., richards d.a., scott e.m., southon j.r., turney c.s.m., wacker l., adolphi f., büntgen u., capano m., fahrni s.m., fogtmann-schulz a., friedrich r., köhler p., kudsk s., miyake f., olsen j., reinig f., sakamoto m., sookdeo a., talamo s. (2020) the intcal20 northern hemisphere radiocarbon age calibration curve (0-55 cal kbp). radiocarbon, 62, 725-757. doi: 10.1017/rdc.2020.41 rottoli m. (2002) italia settentrionale. mesolitico. neolitico. in: storia dell’agricoltura italiana 1. l’età antica. preistoria (ed. by forni g., marcone a.). edizioni polistampa, firenze, 235-240. séara f., roncin o. (2013) mesolithic valley flor occupations: the case of dammartin-marpain in the jura. in: mesolithic palethnography. research on open-air sites between loire and neckar. proceedings from the international round-table meeting, paris, november 26-27, 2010 (séances de la société préhistorique française 2-2) (ed. by valentin b., souffi b., ducrocq t., fagnart j.-p., séara f., verjux c.). société préhistorique française, paris, 93-115. soil survey staff (2010) keys to soil taxonomy, 11th 67 a new early holocene site in central italy: contrada pace ed. usda-ncrs, washington dc, pp.346. stoops g. (2021) guidelines for analysis and description of soil and regolith thin sections. asa, cssa, sssa books and wiley & sons, inc. stoops g., marcelino v., mees f. (2018), interpretation of micromorphological features of soils and regoliths, 2nd edition. elsevier, amsterdam. tagliacozzo a., piperno m. (1993) una struttura di combustione associata ad una porzione di suolo di abitato mesolitico nella grotta delľuzzo (tp). in: atti della xxx riunione scientifica delľistituto italiano di preistoria e protostoria. paleosuperfici del pleistocene e del primo olocene in italia. processi di formazione e interpretazione. istituto italiano di preistoria e protostoria, firenze, 261-276. tomé c., vigne j.d. (2003) roe deer (capreolus capreolus) age at death estimates: new methods and modern reference data for tooth eruption and wear, and for epiphyseal fusion. archaeofauna, 12, 157-173. villa g.m. (1942) nuove ricerche sui terrazzi fluviali delle marche. giornale di geologia, 16, 5-75. villagran x.s., huisman d.j., mentzer s.m. (2017) bone and other skeletal tissue. in: archaeological soil and sediments micromorphology (ed. by nicosia c., stoops g.). john wiley & sons, chichester, 11-38. visentin d. (2018) the early mesolithic in northern italy and southern france. an investigation into sauveterrian lithic technical systems. archaeopress, oxford, pp. 356. visentin d., fontana f. (2016) an intra-site perspective on the sauveterrian lowland occupation of the emilian po plain (northern italy). quaternary international, 423, 58-72. doi: 10.1016/j.quaint.2015.11.104 welter-schultes f. (2012) european non-marine molluscs, a guide for species identification. planet poster editions, gottingen, pp. 679. wierer u., betti l., gala m., tagliacozzo a., boscato p. (2016) seasonality data from the mesolithic rockshelter of galgenbühel/dos de la forca (south tyrol, italy). quaternary international, 423, 102122. doi: 10.1016/j.quaint.2015.12.009 68 visentin d. et al. ms. received: november 15, 2021 revised: april 22, 2022 accepted: june 1, 2022 available online: june 28, 2022 redefining ponte molle (rome, central italy): an important locality for middle pleistocene mammal assemblages of europe. beniamino mecozzi1,2, alessio iannucci1,2, marco mancini3, raffaele sardella1,2 1 dipartimento di scienze della terra, sapienza università di roma, italy 2 paleofactory, sapienza università di roma, italy 3 istituto di geologia ambientale e geoingegneria, cnr, italy. corresponding author: b. mecozzi <beniamino.mecozzi@uniroma1.it> abstract: in this work, the middle pleistocene mammal assemblage from ponte molle, a historical locality of the urban area of rome, has been revised together with a review of the stratigraphical succession of the deposit. this allows us to reconstruct the provenance of the fossil material and to provide chronological constrains trough the correlation with the lithostatigraphic and synthemic units of the national geological cartography and the geochronologically-constrained aggradational units of the paleo-tiber reported in literature. the paleontological study together with the geological and stratigraphical review allow us to redefine the ponte molle deposit and its middle pleistocene faunal assemblage. in its new look, the age of the faunal assemblage from ponte molle could be referred to a time span ranging from 550 ka to 450 ka. keywords: fossil vertebrates, biochronology, galerian, palaeoecology. available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 34 (1), 2021, 131-154 1. the urban area of rome the city of rome lays in one of the most important sedimentary basins of italy for the paleontological research, considering the very high number of fossiliferous findings. the city is crossed by the tiber river, whose evolution is the result of complex geological processes including tectonic, volcanism and glacio-eustatic fluctuations (conato et al., 1980; milli; 1997; karner et al., 2001; giordano et al., 2003; funiciello & giordano, 2008a, b). the tiber river fluvio-deltaic evolution (the “paleo-tiber” system), which commenced during the latest early-earliest middle pleistocene (1.1-0.7 ma; milli et al., 2016), mainly includes sedimentation linked to sea-level rises during the pleistocene glacial terminations (pandolfi & marra, 2015). what follows is a discontinuous stratigraphic record constituted by twelve low rank and high frequency (80-100 ka spaced) depositional sequences, complexly stacked within the basin and deposited by the start of mis 32-31 (marine isotopic stage) (late early pleistocene). in fact, forced by the eustatic and relative falls of the sea level, the tiber river cyclically excavated the fluvial valleys and coastal plain incisions into the bedrock, later filled during the following transgressive and highstand phases with deposits often including pyroclastic products. these were sourced from the alban hills and sabatini mounts volcanic districts, with main activity spanning the 600-250 ka time interval (de rita et al., 1993; marra et al., 2009, 2014; funiciello & giordano, 2010). the presence of volcanic material, among which pumice and tephra interbedded with alluvial-deltaic sediments, is of considerable interest to obtain 40ar/39ar radiometric age dates and therefore to provide reliable geo-chronological constraints for the sediments (marra & florindo, 2014 and references therein). what makes this territory important for paleontological research is the exceptional number of remains recovered over the last 150 years from the alluvial deposits of the paleo-tiber river and its tributaries (e.g., di stefano et al., 1998; petronio & sardella, 1998, 1999; milli et al., 2004). the first findings took place in the 1800s, when the fluvial deposits were investigated by eminent scientists of the time, such as giuseppe ponzi and alessandro portis (funiciello & rosa, 1995; funicello & giordano, 2008b; romano et al., 2021). the majority of the fossil remains was collected from deposits outcropping in the urban area of rome and its periphery, due to the intense urbanization and quarry activities (e.g., portis, 1893, 1896,1900). many works focused on the description of these fossiliferous localities and their remains (e.g., di stefano et al., 1998; petronio & sardella, 1999), even if often most of them lacks exact stratigraphic constrains and is not always associated to a precise sedimentary level (gravel, sand, clay) (pandolfi & marra, 2015). most of the historical collections from the area of rome is stored at the “museo universitario di scienze della terra (must)” (earth science university museum, sapienza university of rome) (including the former museo di paleontologia di roma, mpur). unfortunately, the paleontological collections endured a series of misadventures, as for instance the overflow of the tiber river in 1870 (portis, 1893) or the bombardment that struck the department of earth sciences of sapienza university (rome) carried out by the american army https://doi.org/10.26382/amq.2021.09 132 mecozzi b. et al. fig. 1 geological sketch map of the ponte molle-tor di quinto area (from funiciello & giordano, 2008a; modified), with trace of the geological cross section (fig. 2), the location of the cava d’alessandri and boreholes used for stratigraphic analysis (figs 4, 5). toponyms refer to the historical geological maps by tellini (1893) and verri (1915); see also figure 3. 133 ponte molle: a middle pleistocene mammal assemblage during the world war ii (fabiani & maxia, 1953; mecozzi et al., 2020). these episodes caused the loss and damage of many fossil specimens or of their associated labels. nonetheless, the fossil remains recovered from the urban area of rome and its surroundings, also known as campagna romana (roman campaign), represent the most abundant middle pleistocene fossil samples founded in italy, and thus the area assumes a key-role in the study of vertebrate assemblage evolutionary trends and palaeoenvironmental reconstructions. the importance of this territory is reflected in the large land mammal biochronological scale, where two roman localities are chosen as faunal units: ponte galeria and torre in pietra (gliozzi et al., 1997). in this work, we analyze the fossil sample from ponte molle (also known as ponte milvio) (pm), a historical locality of the urban area of rome described by portis (1893). the revision of the stratigraphical succession of the deposit allows us to reconstruct the provenance of the fossil material and to provide chronological constrains trough the correlation with the lithostatigraphic and synthemic units of the national geological cartography (carg project; funiciello & giordano, 2008a, b) and the geochronologically-constrained aggradational units of the paleo-tiber reported in literature (marra et al., 2014). 2. ponte molle and its troubled history the presence of the fossil remains in the tiber alluvial deposit in the tor di quinto area was already reported in the second half of the 19th century, when ponzi (1867) recognized the occurrence of several species from the quarries opened at pm, from the same gravels quarried for building material (tab. 1). the stratigraphical succession exposed in the quarry called cava d’alessandri was firstly described by portis (1893). in this work, he illustrated several sedimentary deposits occurred in the city of rome, with a special focus on the northern-western area, where in addition to cava d’alessandri, the successions exposed at tor di quinto (=torretta di quinto) and acquatraversa (all located in the tor di quinto district) were also described (fig. 1). the author pointed out the presence of fossil remains referable to the “classical” fauna of pm (implying that findings of similar assemblages were already common) only from the lowermost level of the stratigraphic succession (tab. 1). this level, consisting of tuffaceous gravels and sands (i.e. with tuffaceous clasts and minerals of volcanic origin), and including a diversified faunal assemblage, was the first properly described outcrop of the “cosiddette ghiaie diluviali di ponte molle” [so-called diluvial gravel of ponte molle]. later, portis (1902) described an isolated upper molar belonging to a juvenile specimen classified as elephas antiquus (=palaeoloxodon antiquus) (tab. 1). portis (1907) analyzed the sample of bovidae from several deposits of the urban area of rome and its surroundings, attributing several cranial remains from pm to bos primigenius (tab. 1). portis (1909) studied the canid fossil remains from the urban area of rome, among which two fragments of hemimandible and one isolated lower carnassial from the “cosiddette ghiaie di ponte molle presso cava d’alessandri” were referred to a small-sized form of canis lupus (tab. 1). in addition, he noticed that in the fossil collection of ponzi two replica, a fragment of maxillary and a fragment of hemimandible, respectively, were present, but the original remains were missing. these two fossils were also referred to c. lupus. portis (1909) also attributed a complete femur to meles meles (=meles taxus) and an upper canine to the genus lynx, both collected from the basal level of cava d’alessandri (tab. 1). later, portis (1920) listed the cervidae taxa identified in the city of rome and its surroundings, reporting the presence of cervus (praealces) latifrons from pm (tab. 1). however, due to the intense urbanization of the area, the quarries and the other aforementioned outcrops were destroyed or buried below anthropogenic deposits. following this, subsequent studies were conducted exclusively on the historical fossil collections recovered during the end of 1800s and the first decades of 1900. during the 1960s, ambrosetti & bonadonna (1967) resumed the paleontological research on this locality and correlated the pm fauna with the ponte galeria formation (sensu conato et al., 1980) exclusively on the basis of the occurrence of some galerian taxa, even if no description of the materials was performed. after decades, caloi & palombo (1986) carried out the revision of the fossiliferous localities of the area of rome and listed the following species from the lower level of ponte milvio (=ponte molle): cervus (cervus) acoronatus, cervus (dama) sp. (=cervus [dama] quirinus), megaceros cf. solilhacus (=cervus [praealces] latifrons) and hippopotamus incognitus (tab. 1). even in this case, neither descriptions nor figures of the fossil sample were included. di stefano & petronio (1992) firstly described the mammal assemblage from pm, identifying two distinct faunal assemblages, as they regarded some mammals as galerian forms (e.g. c. elaphus acoronatus) and others as more typical elements of late middle to late pleistocene assemblages (e.g. dama clactoniana) (tab. 1). capasso barbato et al. (1998) realized a preliminary revision of the deposit, recognizing at least three different assemblages of middle pleistocene age and also referring a few specimens to the holocene (tab. 1). shortly after, di stefano et al. (1998) further detailed the “twoassemblages” hypothesis, attributing the first to isernia faunal unit (early middle pleistocene) and the second to vitinia faunal unit (late middle pleistocene), mainly on the ground of the presence of different fallow deer subspecies, respectively dama clactoniana and dama dama tiberina. more recently, an isolated horn-core stored at the monastery of santa scolastica in subiaco (rome), previously referred to bubalus murrensis by cassoli & segre (2004), was ascribed to hemibos galerianus by martínez-navarro & palombo (2007) (tab. 1). palombo (2004) figured a partial cranium with nearly complete antler classified as c. elaphus acoronatus and a partial cranium and complete antler ascribed to d. dama tiberina (=dama quirinus). billia & petronio (2009) revised the rhinocerotidae sample, recognizing only the presence of stephanorhinus kirchbergensis, whereas pandolfi (2013) and pandolfi & marra (2015) identified three different taxa: s. 134 t a b . 1 m a m m a l ta x a f ro m p o n te m o lle r e p o rt e d i n p re v io u s w o rk s . mecozzi b. et al. ly described outcrop (portis, 1893). despite several specimens from this site have been object of study (e.g., capasso barbato et al., 1998; di stefano et al., 1998), an in-depth analysis is still needed to redefine the faunal assemblage. 3. geological setting the study area of pm and tor di quinto is located on the right bank of the tiber river and corresponds to a well preserved fluvial terrace, with 50-60 m a.s.l. mean elevation, laying eastward of the n-s directed monte mario-monti della farnesina ridge, up to 140 m high (fig. 1). the terrace is bounded to the east and south by the alluvial plain of the meandering tiber river, at 16 m a.s.l., and to the north by the narrow valley of fosso dell’acquatraversa. the original terrace relief, as deduced by the observation of historical geological and topographic maps (tellini, 1893; verri, 1915; igm, 1936), was characterized by a gentle undulating topography interrupted, internally, by small n-s oriented valleys and at the northern and eastern edges by steep scarps, where natural outcrops were exposed and examined by the authors (portis, 1893; de stefani, 1904). nowadays the natural landform is strongly modified after a re-shaping from the intense urban transformations of the last 120 years, and almost no exposures are preserved. on the local stratigraphy, the bedrock corresponds to the marine clay, silt and sands of the monte vaticano and monte mario formations, attributed respectively to the zanclean-gelasian and to the late santernian (calabrian) (funiciello & giordano, 2008a, 2008b). the bedrock crops out along the monte mario-monti della farnesina ridge, is found in the subsoil of the fluvial terrace (fig. 2), and is crossed by nw-se trending normal faults down-throwing the north-eastern blocks kirchbergensis, stephanorhinus hemitoechus and stephanorhinus hundsheimensis, as well as several remains undeterminable at specific level (stephanorhinus sp.) (tab. 1). pandolfi & marra (2015) also proposed a reinterpretation of the age of the deposit. they noticed that part of the specimens labels report that fossils were collected from “gravels and sands” and others from “tuffaceous conglomerates”, and supposed this as indicative of the presence of two levels of different age: the lower one, a gravel and sand level where s. hundsheimensis occurred; and the upper one, a tuffaceous conglomerate level which included s. kirchbergensis and s. hemitoechus. this upper level was correlated with a tephra detected at 1.5 km along via flaminia nuova, dated at 465±7 ka, whereas the lower level was correlated to the base of the paleo-tiber 2 cycle at 810-790 ka (pandolfi & marra, 2015). however, from an historical perspective, this label-based repartition of the assemblage is not supported. in fact, even not accepting early researchers’ interpretations, they explicitly regarded the fauna of pm as coming from a single level (ponzi, 1867; portis, 1893). consequently, they would not have reported on the labels a separation that they had not observed in the field. moreover, even though some labels do report “gravels and sands” and others “tuffaceous conglomerates”, others again indicate “gravels, sands, and tuffaceous conglomerates”, or even “so-called gravels of ponte molle” or variable combinations of these forms, which clearly were all different ways to refer to the same thing: a fluvial formation with gravel and sand, rich in fossils and volcanic material. the so-called fauna of pm was the typical assemblage recovered from the gravel quarries and other sporadic findings occurred during construction works in the district of tor di quinto, in the northern-western area of rome (ponzi, 1867). several specimens were recovered from cava d’alessandri, which was also the first proper 135 ponte molle: a middle pleistocene mammal assemblage fig. 2 geological cross section of the ponte molle area. the trace of the section is represented on figure 1. 136 mecozzi b. et al. (funiciello & giordano, 2008a; cosentino et al., 2009). the terrace is composed of an approximately 50 m thick succession of fluvial deposits with interbedded pyroclastic units, which covers with angular unconformity the bedrock; it is interpreted as an alluvial fill terrace (merrits, 2007; pazzaglia, 2013). at the base are present alternated gravel, sand and silt of the fosso della crescenza and santa cecilia formations of the latest early pleistocene-early middle pleistocene. they record the oldest fluvial sedimentation in the area, up to the mis 16-15, and are covered by the via tiberina unit (tufo giallo della via tiberina auct) an approximately 550 ka old and few meters thick ignimbrite (karner et al., 2001), sourced by the sabatini mts district and cropping out close to the torretta site. most of the fill terrace is represented by the fluvial valle giulia formation (mis 14-13), up to 30 m thick and composed of basal channel gravels grading upward into cross bedded sands, travertine, tufas and floodplain muds. this formation has a relatively high-relief basal unconformity carved into the bedrock and older fluvial deposits and defines an approximately n-s directed paleo-valley infill (giordano et al., 2003; funiciello & giordano, 2008a; marra & florindo, 2014; giustini et al., 2018). the formation is rich in volcanoclastic material, re-sedimented in the fluvial environment, and crystals of volcanic origin found in the sandy matrix of the gravels. north of the acquatraversa stream the “tufi stratificati varicolori di sacrofano” crop out, composed of alternated ash and lapilli sized fallout beds (510-460 ka old) that, along with the valle giulia formation, define the villa glori synthem. on the top of the terrace there are locally present the “tufo rosso a scorie nere sabatino”, a red massive ignimbrite with back scoria (about 449 ka old; karner et al., 2001) and the overlaying vitinia formation (late middle pleistocene, approximately 285-270 ka old; karner et al., 2001; giordano et al., 2003) composed of few meters thick pebbly sand and mud, rich in volcanic minerals. the vitinia formation corresponds in this area to the “formazione fluvio-lacustre” by ventriglia (1971, 2002). finally, the tiber river plain and acquatraversa valley are composed of basal gravels and overlaying channel sands and floodplain mud with interbedded peat layers of the tiber river synthem (or tiber depositional sequence sensu milli et al., 2016), which records the last cycle of fluvial incision and sedimentation of late pleistocene-holocene (mis 5d-1). anthropogenic deposits, up to 15 m thick, cover the natural substratum in most of the study area. 4. materials and methods the osteological analyses of the large mammal fauna from the middle pleistocene site of pm were carried out, considering remains collected from the end of 1800 to early decades of 1900. the fossil remains are stored at must. taxonomic and skeletal element identifications made in this study are based on the reference collection of the paleofactory laboratory, department of earth sciences, sapienza, university of rome (pf). in order to evaluate species abundance, the count of the number of remains (nisp) (grayson, 1984) and the estimate of the minimum number of individuals (mni) (bökönyi, 1970) have been performed (tab. 2). in addition, the age at death was also determined. we carried out biometric comparisons for a selection of taxa relevant for their biochronological and paleoenvironmental significance: bos primigenius, mediumsized deer (dama spp. and dama-like), sus scrofa, and hippopotamus. for b. primigenius and medium-sized deer, we measured the maximum meso-distal length above the root-crown junction of the lower third molar (m3l). for s. scrofa, measurements of the lower third molar were taken following von den driesch (1976). for hippopotamus ssp. measurements of the lower third molar were taken following mazza (1995): ol: outer length; ab: anterior breadth. measurements were taken with a digital caliper to the nearest 0.1 mm. for bos primigenius we considered specimens stored in the following institutions: contrada cozze, casa minniti (national archeological museum of melfi); as well as literature data: punta lucero (gomez-oliveira et al., 2015); malagrotta (caloi & palombo, 1979); igue des rameauxamont, lunel-viel, pech de l’azé ii (uzunidis-boutillier, 2017); fara sabina (angelelli, 1981); ilford (wright, 2013). subfossil samples of bos taurus from elvas-kreuzwiese (boschin, 2018) and silves-lix (davis et al., 2008) were also included. we selected the m3 since it is the best documented tooth in the studied sample. in addition, this tooth is easily distinguishable from the other lower molars, which makes more reliable the literature data used for comparison. morphometric data of medium-sized deer from pirro nord and extant italian specimens of dama dama dama stored at pf have been considered. literature data of several medium-sized deer taxa have been included: pseudodama group: kalamotó (dama sp., tsoukala & chatzopoulou, 2005); saint-prest (dama sp., guérin et al., 2003), erpfinger höhle (dama nestii, lehmann, 1957), le vallonnet (dama vallonnetensis, de lumley et al., 1988), cueva victoria (pseudodama vallonnetensis, van der made, 2012), atapuerca td8 (dama vallonnetensis, van der made et al., 2017a); dama roberti: pakefield, westbury, west runton (breda & lister, 2013), contrada monticelli (dama cf. roberti; stefanelli et al., 2021), valdemino (breda, 2015); dama clactoniana: fontana ranuccio, grays thurrock, jarwick, visogliano (di stefano, 1994), notarchirico (cassoli et al., 1999), atapuerca td11 (azanza & sanchez, 1990), caune de l’arago (dama cf. clactoniana, magniez et al., 2013). we selected the lower third molar (m3 ) since it is the best documented tooth in our dama sample. in addition, this tooth can be easily recognized from the other lower molars, and therefore a misleading interpretation can be excluded from the data taken from the paleontological literature. for sus scrofa we considered specimens studied in the following institutions: bristie 1 (civic museum of natural history, trieste), melpignano (pf), and literature data for west runton, trimingham, grays thurrock, oreston, hutton (lister et al., 2010); petralona (tsoukala & guérin, 2016); kyparíssia (atanassiou et al., 2018); gajtan, lunel-viel (fistani, 1996); cerè (fabiani, 1919); torre del pagliaccetto (caloi & palombo, 1978), and extant italian wild boar (iannucci et al., 2020b); considering that a relationship between size shifts in s. scrofa and environmental fluctuations has been recently recognized in late middle pleistoceneearly holocene apulia (southern italy), we also included several late pleistocene apulian localities in the comparison, grouped in “glacial” (mis 4 a n d 2 ) a n d “interglacial” (mis 5 and 3) samples (iannucci et al., 2020b). we selected m3 as it is widely available in our sample and in the literature, as well as being easily identifiable and common focus of studies on wild boar morphometry. we also considered morphometric literature data of genus hippopotamus from plio-pleistocene sites of europe as well as extant hippopotamus amphibius (mazza, 1995). we selected m3 because it is the most numerous tooth in our sample. for investigating chronological and/or geographical biometric variability and possible size variations in the selected taxa we used boxplots of m3 length, for b. primigenius, medium-sized deer, and s. scrofa; and plot of length vs breadth of m3 for hippopotamus. 4.1. cartography and stratigraphic analysis historical and modern geological and topographic maps have been analyzed and compared among each other (tellini, 1893; verri, 1915; igm, 1936; ventriglia, 1971, 2002; funiciello & giordano, 2008a), coupled with a bibliographic review of scientific articles and historical chronicles (ponzi, 1867; portis, 1893; de stefani, 1904; ranzato, 2019), in order: 1) to locate as precisely as possible the cava d’alessandri, other old toponyms and fossil sites of pm, and the described stratigraphic sections no longer observable; 2) to infer the position and areal extension of other old quarries active between the last decades of the 19th and first half of the 20th century (fig. 1). in particular, the synoptic observation of old maps, from the oldest to the youngest, has allowed to individualize changes in the shape of topographic contour lines (i.e. from a convex to a concave one) resulting in halfcircular morphologies in plain view, here interpreted as ancient quarry fronts and floors (see also ciotoli et al., 2015, for the method). in situ observations and 3d views from the software google earth image©2019terrametrics has permitted, in some cases, to recognize steep scarps and differences in heights within the urbanized area, strengthening the hypothesis of old quarry fronts. the stratigraphic section of cava d’alessandri has been drawn basing on the description by portis (1893), who reported the precise position of the unique vertebrate-bearing level of the quarry. to reconstruct the stratigraphic architecture of the pm-tor di quinto infill terrace, two correlation panels among the cava d’alessandri section and 15 borehole logs have been realized. the latter deriving from literature and unpublished data (ventriglia, 2002) and stored in the cnr igag database of subsoil data of rome (cavarretta et al., 2005). correlation was based on the application of standard methods of physical stratigraphy on core data (bridge, 2003; collinson et al., 2006) with particular emphasis on the identification of key bounding surfaces and architectural elements: main unconformities, channel bodies, floodplain deposits. this has allowed to put the vertebrate-bearing level of cava d’alessandri into the correct physical and chrono-stratigraphic frame. 5. results 5.1. geography and stratigraphy from the compared analysis of cartographic and literature data (portis, 1893; tellini, 1893; de stefani, 1904; verri, 1915) it appears that cava d’alessandri was likely sited on the northern flank of via flaminia about 150 m north of the osteria di melafumo (tavern), with this tavern located just after pm (fig. 1). figure 1 shows the localities mentioned by the authors and ancient toponyms, in some cases no longer in use, plotted on a sketch of the modern geological map of rome (funiciello & giordano, 2008a). on the tellini’s (1893) geological map a small n-s trending topographic depression can be noticed, which cuts transversally the southern slope of the pm-tor di 137 ponte molle: a middle pleistocene mammal assemblage fig. 3 sketches of the historical geological maps by tellini (1893) on the left, and verri (1915) on the right, showing the area of ponte molle and its transformations between the late xix and the early xx century. in the tellini’s (1893) map there are featured a small n-s oriented topographic depression, just north-east of the osteria (di melafumo) toponym, in the same area described by portis (1893), and a fossil site (red asterisk; see also figure 1). in the verri’s (1915) map it is reported the c. d’alessandri toponym just north of the osteria, and the topographic depression (the former quarry) is replaced by a newly built area (v. trezza toponym). quinto terraced relief. this place roughly corresponds to the c. d’alessandri toponym, as reported on the later verri’s (1915) geological map (fig. 3). the topographic depression of the tellini’s (1893) map is interpreted as the ancient cava d’alessandri (fig. 1), being it substituted by a re-covered area with small buildings above it in the verri’s (1915) map. this testifies the very rapid changes of the growing city in the pm area. another fossiliferous site was shown by tellini (1893) further north along the via flaminia, and is reported on figure 1, as other old quarries and the outcrops described by portis (1893): torretta and acquatraversa. the stratigraphy of cava d’alessandri described by portis (1893) is represented on figure 4. the vertebrate-bearing level was located in the lower cross bedded fluvial gravels, 8.5 m thick, that are replaced above by calcareous sand and silt (1.5 m thick) and by a finingupward succession (16 m thick) of sandy pebbles, grey sand and silt with concretions, plant fragments and freshwater and terrestrial mollusks (corbicula fluminalis, helicidae). from the modern geological map, cava d’alessandri belongs to the valle giulia formation (fig. 1), ascribed to the intermediate portion of middle pleistocene and correlated with mis 14-13 (funiciello & giordano, 2008b). the stratigraphic-sedimentological log of cava d’alessandri is correlated with nearby borehole logs (see also figures 1 and 2 for their location), which allows to define the stratigraphic architecture of the pm-tor di quinto infill terrace. the two produced correlation panels are presented on figure 5. the first panel (fig. 5a), in which the cava d’alessandri log is plotted, is nw-se oriented with an across-valley direction; the other (fig. 5b) is almost perpendicular in the along-valley direction (ne-sw). the panels detail the stratigraphic setting already shown in the cross section of figure 2, with the marine bedrock of the monte vaticano and monte mario formations, the overlaying middle pleistocene formations composing the aggradational terrace (fosso della crescenza and santa cecilia formations, via tiberina unit, valle giulia formation, “tufo rosso a scorie nere sabatino”, vitinia formation), the late pleistoceneholocene tiber river synthem in the plain, the anthropogenic deposits. the main unconformity separating the bedrock from the overlaying infill terrace of pm-tor di quinto results from the enveloping of the singular basal unconformities of the fluvial fosso della crescenza, santa cecilia and valle giulia formations, all incised by the ancient tiber into the bedrock in response of recurrent sea level falls and lowstands. the infill terrace is thus the result of the complex vertical and lateral stack of several middle pleistocene units, with a discontinuous stratigraphic-sedimentologic record occurred throughout the approximate 0.80-0.27 ma time interval. the oldest fluvial and pyroclastic units (fosso della crescenza, santa cecilia formations and via tiberina unit) are rarely crossed by the well cores in the eastern portion of the terrace. the fluvial sediments are represented by prevailing beige sand and silt, with intercalated pebbles and with a reddish-brown paleosol on the top (p2313 borehole; fig 5b). conversely, the panels show for the valle giulia formation the classical pattern of infill of the quaternary fluvial incised valleys in the rome area, i.e. that related both to the tiber river and tributaries (milli, 1997; milli et al., 2008, 2016; mancini et al., 2018), with a high relief unconformity, basal gravels and overlaying alternated sand and fine deposits. the basal unconformity of valle giulia formation is well incised into the marine bedrock and the older fosso della crescenza-santa cecilia formations and via tiberina unit (550 ka old); it records the sea level fall occurred between the mis 15 and mis 14, and the mis 14 lowstand of sea level (glacial phase). 138 mecozzi b. et al. fig. 4 stratigraphic-sedimentologic log of the cava d’alessandri; see figure 1 for the location of the log (red triangle). 139 ponte molle: a middle pleistocene mammal assemblage fig. 5 correlation panels among borehole logs and the cava d’alessandri log detailing the stratigraphic architecture of the ponte molletor di quinto terrace: a) across-valley panel; b) down valley panel; c) legend. the location of boreholes is on figure 1. 140 mecozzi b. et al. tab. 2 mammal fossil remains from ponte molle stored at must. 141 ponte molle: a middle pleistocene mammal assemblage the lower portion of the incised-valley fill corresponds to amalgamated sandy gravels, 10-15 m thick, with cross bedded bars and bedforms of the braided river environment. the fossiliferous gravels correspond to the “cosiddette ghiaie diluviali di ponte molle” by portis (1893) and form a laterally and downstream continuous body with tabular shape. they are related to the onset of the sea level rise occurred between mis 14 and mis 13 (latest lowstand and early transgressive phases of filling), at the end of the glacial phase. above the gravels, fluvial pebbly-silty sands alternate with floodplain fine deposits and with travertines and freshwater tufas. all these deposits recorded the fluvial sedimentation in response to the late rise and highstand of sea level during the mis 13 (transgressive and highstand phases) and under interglacial climate conditions. the sands define at least three vertically stacked channel bodies (sensu gibling, 2006), each 10 m thick, lens shaped and with fining upward arrangement of facies, from pebbly to silty sand (fig. 5a). the channel sands, likely attributed to a meandering-style fluvial system (as compared to other analogues in the rome area; milli et al., 2016), are laterally confined by planar bedded floodplain silt and muds, and by travertines and tufas of fluvial and spring environments. travertines and tufas, cropping out at tor di quinto, define a downstream almost continuous tabular body in the intermediate portion of the incised valley fill, at 20-30 m a.s.l. elevations (fig. 5b). these continental carbonates record a well-known phase of increasing caco3 deposition by spring waters, related to a renewal of the local tectonic activity during the mis 13 (funiciello & giordano, 2008b). on the top, the valle giulia formation is constrained by the 449 ka old “tufo rosso a scorie nero sabatino”, which deposited on a morphologically very articulated surface recording the main fluvial incision at the mis 13-12 transition. a following phase of fluvial sedimentation is represented by the via tiberina unit, that deposited at the end of mis 9 and mis 8.5 (giordano et al., 2003). 5.2. faunal assemblage from ponte molle the fossil sample from pm includes 741 taxonomically identified elements recovered from the lower part of the deposit, chronologically referred to the middle pleistocene (tab. 2) (fig. 6). the faunal assemblage is largely dominated by bos primigenius (50.5%), which is mainly represented by isolated upper and lower teeth (tab. fig. 6 mammal fossils from ponte molle: a 415, right hemimandible of bos primigenius in labial view; b 426, right hemimandible of bos primigenius in labial view; c -1857, right maxillary of palaeoloxodon antiquus in occlusal view; d 46, left hemimandible of hippopotamus ex gr. antiquus in lingual view; e 166, left lower third molar of sus scrofa in lingual view; f 718, right hemimandible of capreolus capreolus in labial view; g 1175, right lower third premolar of crocuta crocuta in labial view; h 128, right hemimandible of castor fiber in lingual view. scale bar 3 cm. 142 mecozzi b. et al. 2). the cervids (cervus elaphus eostephanoceros and dama clactoniana) (14.5%), a large equid (equus mosbachensis) (8.1%), the straight tusked elephant (palaeoloxodon antiquus) (7%), rhinos (stephanorhinus hemitoechus, stephanorhinus kirchbergensis, stephanorhinus sp.) (7.6%) and hippopotamus ex gr. antiquus (=hippopotamus tiberinus) (6.7%) are well represented, whereas sus scrofa, equus hydruntinus and capreolus capreolus are quite scarce (tab. 2). a single antler testifies the presence of cervus elaphus acoronatus (fig. 7). the middleto small-sized mammals are represented by a lower number of fossils (2.7%), among these, there are 14 remains ascribed to a single lynx individual. a restricted part of the sample is referred to juvenile individuals (9.8%), nearly exclusively represented by isolated teeth: h. ex gr. antiquus (2 specimens), s. hemitoechus (2 specimens), stephanorhinus sp. (3 specimens), b. primigenius (37 specimens), c. elaphus eostephanoceros (1 specimen), e. mosbachensis (13 specimens) and e. hydruntinus (1 specimen). an exception is represented by the remains of lynx sp., where 14 juvenile postcranial specimens belonging to the same skeleton. the fossils are in a good state of preservation, although often enwrapped by a thin crust of sand with abundant volcanic material that range from reddish to greyish. a few specimens, especially the remains referable to large herbivores, are partially embedded in pebbles whose dimension vary from a few millimeters to more than ten centimetres. in the fossil material there is no sign of bite marks or rodent gnaw marks, or human butchering and exploiting activity. therefore, it is possible to suggest that carnivorans or humans did not play any key role in the accumulation of the fossil remains. unfortunately, the stratigraphic information written on specimen’s labels is quite limited, preventing further taphonomic analyses. finally, likely deriving from the upper part of the deposit, clearly chronologically referable to the holocene due to their preservation, several species were identified: b. primigenius (11 specimens), bubalus sp. (1 specimen), c. elaphus (1 specimen), equus ferus (6 specimens), e. hydruntinus (5 specimens) and m. meles (14 specimens; mecozzi, 2021). 5.3. taxonomic revision the fossil sample from pm was never systematically studied, with only a preliminary faunal list reported by di stefano & petronio (1992) and capasso barbato et al. (1998) (tab. 1). here, we revised the fossil material stored at must. the cervid sample is referred to four taxa: c. elaphus acoronatus, c. elaphus eostephanoceros, d. clactoniana and c. capreolus. the subspecies c. elaphus acoronatus is represented by a partial cranium and a nearly complete antler (fig. 7), whereas the rest of the red deer sample is classified as c. elaphus eostephanoceros (fig. 7). these two red deer subspecies differ in the terminal part of the antler: a simple bifurcation in c. elaphus acoronatus and a real crown with at least 5 tines in c. elaphus eostephanoceros. these two taxa were reported by di stefano & petronio (1992, 1993) and their presence in the faunal assemblage from pm is confirmed. considering the medium-sized deer, no remain can be attributed to euraxis eurygonos (=axis eurygonos). the only fallow deer recognized from pm is d. clactoniana (fig. 8). di stefano & petronio (1997) proposed a new fallow deer subspecies based on the sample of pm, d. dama tiberina. the main diagnostic features of this taxon are related to the morphology of the antlers, which should be different from d. clactoniana in: a posterior direction of the spellers on the palm; a more basally located brow tine; brow tine and the trez tine less developed; flatter palm and terminal tines. nevertheless, the morphology of the antler from pm is extremely close to that of d. clactoniana from fontana ranuccio, riano and swanscombe (fig. 8). considering that the taxonomy of the plio-pleistocene cervid is mainly based on antler (e.g., di stefano & petronio, 1993; breda & lister, 2013), the morphological affinity of the antler from pm to that of d. clactoniana suggests it belongs to the same species, thus invalidating the validity of the subspecies d. dama tiberina. the differences proposed by di stefano & petronio (1997) are not enough to separate d. fig. 7 antlers of cervus elaphus from ponte molle: a, ce 4 cervus elaphus acoronatus in frontal (1) and medial (2) views; b, sn151/fs, cervus elaphus eostephanoceros in lateral (1) and medial (2) views. scale bar 3 cm. 143 ponte molle: a middle pleistocene mammal assemblage third molar (see sala, 1986 for discussion). in postcranial elements, clear diagnostic features are less numerous but however significative, as the distally divergence of the medial and lateral intercondylar crests in metapodials (see sala, 1986, for the description of other diagnostic features). the overall morphology of the sample from pm is close to that of b. primigenius. equids are the other well represented group in the faunal assemblage from pm, with two forms welldifferent in size. the taxonomic status of the middle pleistocene equus is still a controversial topic, and no consensus is reached (van asperen, 2012; boulbes & van asperen, 2019). the open issues concern how to interpret the biometric variations, if related to intraspecific variability or ecomorphotypes (e.g., van asperen, 2012; boulbes & van asperen, 2019). as such, several authors referred the middle pleistocene fossils to e. mosbachensis, taxon only characterized for its large size and a few features of the postcranial elements (e.g., presence of the tendon insertion of the anterior brachialis muscle on the inner edge of the diaphysis of the radius, strong supra-articular tuberosities on metapodials) (e.g., uzunidis-boutillier, 2017; boulbes & van asperen, 2019). conversely, van asperen (2013) considered the european middle pleistocene sample as a single species, e. ferus ssp. the dental remains from pm are large-sized, whereas the postcranial elements provided no element for a taxonomical allocation. considering the dimensions, the specimens are referred to the european middle pleistocene e. mosbachensis. a few teeth of equid from pm can be instead referred to a small-sized form. dental diagnostic features of e. hydruntinus have been summarized by boulbes (2009): angular parastyle, rounded and narrow normally mesostyle, a deep postprotoconal valley, pli caballin simplified and short protocone in the upper teeth; metastylid longer than metaconid, with a less deep linclactoniana and d. dama tiberina, but rather fall within the intraspecific morphological variability of the former. by contrast, the overall antler morphology of d. clactoniana largely differs from that of d. dama (see leonardi & petronio, 1976 for discussion). a small-sized deer is also documented at pm, attested by a nearly complete hemimandible. its morphology cannot be distinct from that of the extant specimens of capreolus capreolus. another cervid taxon was reported at pm, classified as megaceros cf. solilhacus (=cervus [praealces] latifrons) (tab. 1). despite this, no remains of the must collection can be referred to a megacerine deer, but we cannot exclude that specimens of this taxon are stored in other repositories, as in the case of the horn core of hemibos galerianus. the taxonomical identification of middle pleistocene bovids faced considerable difficulties, especially for isolated and/or fragment fossils. nevertheless, the sample from pm includes 374 remains, including diagnostic elements (tab. 2). portis (1907) also described several cranial fragments. we were able to recognize only a few of these specimens in must. there are, however, a few crania and cranial fragments in the old collection of must without information on their provenance and in need of restoration, some of which could have been recovered from pm. several features can be detected in the pm sample: horn cores inserted in the cranium in a more latero-posterior position, with an outward and backward direction in the proximal part, and upward and slightly forward in the terminal part (e.g., portis, 1907, plate xiii, fig. 3); well-developed entostyle and a more columnar and hypsodont appearance (swelling absent) of the upper molars; v-shaped enamel around the central cavity of both the upper and lower molars; the two main lobes more mesiodistally developed in the lower molars; presence of a small accessory stylid between hypoconid and hypoconulid in the lower fig. 8 antlers of fallow deer: a, mpur 605 from ponte molle; b, riano 6 from riano (leonardi & petronio, 1976); c, 16349 from swanscombe (leonardi & petronio, 1976); d, fr56539 from fontana ranuccio (cassoli & segre naldini, 1993); e, no catalogue number of extant italian specimen of d. dama dama (di stefano & petronio, 1993). colours: yellow -dama clactoniana; green extant dama dama dama. the images are not in scale. gual groove, a deep ectoflexid (on molars) and a few marked or absent pli caballin in the lower teeth. these features have been observed in the sample from pm, and therefore the presence of e. hydruntinus can be confirmed. the hippo remains are very common in the european pliopleistocene record, but even in this case there are conflicting opinions on their systematics and evolution (see van der made et al., 2017b for discussion). three forms are generally recognized: hippopotamus antiquus, hippopotamus ex gr. antiquus (= h. tiberinus) and hippopotamus amphibius. whereas the last shows clearly diagnostic morphological characters, well different than the other two taxa, h. antiquus and h. ex gr. antiquus differ mainly for their size (mazza, 1995; mazza & bertini, 2013). following the taxonomical diagnosis proposed by mazza (1995), the morphology of the specimens from pm falls in the variability of h. antiquus. based on the medium size of the remains, the sample from pm is ascribed to h. ex gr. antiquus. the elephant sample from pm includes fragmentary tusks, partial maxillaries and hemimandibles, isolated upper and lower teeth and several postcranial elements (tab. 2). tusks are incomplete and no useful taxonomical characters can be observed. dental remains are hypsodont and generally possess a high number of laminae, a high lamellar frequency, reduced enamel thickness and less developed cementum. these features are considered typical of p. antiquus (palombo, 1986, 1995; palombo et al., 2003). one of the groups better investigated from pm is the rhinocerotidae. the sample was taxonomically identified for the first time by capasso barbato et al. (1998), who recognized the presence of s. kirchbergensis and s. hemitoechus. six isolated teeth of s. kirchbergensis were carefully described by billia & petronio (2009) (tab. 3). pandolfi (2013) revised these specimens and studied other rhino remains from pm (tab. 3). the author classified as s. hundsheimensis four teeth previously attributed by billia & petronio (2009) to s. kirchbergensis, and referred other three teeth to s. kirchbergensis and four to s. hemitoechus. we need to take into account that pandolfi (2013) recognized two distinct faunal assemblages, referred to ponte galeria and vitinia fus respectively. following this chronological repartition, the author attributed a few fossils from this hypothetical “lower level” to s. hundsheimensis. the revision of the material from pm supports the classification of billia & petronio (2009) for mpur 1412/8, mpur 1417/115, mpur 1421/107, mpur 1445/27, mpur 1454/117 and mpur 1454/118 as s. kirchbergensis. the revision of mpur 1420/97 led doubt on the presence of s. hundsheimensis. in fact, its morphology differs from the p4 of s. hundsheimensis from isernia la pineta (ballatore & breda, 2013) in the profile of the 144 mecozzi b. et al. tab. 3 stephanorhinus remains identified in previous works reported the presence of lynx, canis lupus and meles meles (tab. 1). according to the author, the lynx sample included a partial hemimandible, currently lost. other fossils belong to the same skeleton probably found in anatomic connection. a recent study focuses on evolutionary history of european fossil lynxes, which reveals as l. pardinus (=lynx spelaeus/lynx pardinus spelaeus) is the only lynx recognized during the middle pleistocene (mecozzi et al., 2021a). in the pm sample, only skeleton remains are documented, which have small dimensions. nevertheless, postcranial diagnostic characters in fossil lynxes are quite unmapped. considering this, we attributed these specimens to lynx sp., avoiding the taxonomical attribution based on chronological grounds. canid sample consists of a lower canine and two replica of left maxillary and right hemimandible respectively. portis (1909) noted the lacking of the original specimens, writing (pag. 220):“dove si trovano conservati gli originali di questi due modelli?” (where are the original specimens of these two replica stored?). in addition, three specimens, two partial hemimandibles and a lower first molar described by portis (1909), are not present in the must sample. the available material shows a reduced size and the protocone of the upper fourth premolar is aligned with the mesial margin of the teeth. a small -sized canis, currently lost, was also reported by portis (1909). thus, we suggest a possible attribution to canis cf. mosbachensis. portis (1909) also described the right complete humerus of the european badger. the revision of this fossil confirms its attribution to m. meles. postfossette and the medisinus. in this scenario, we confirm the presence of s. kirchbergensis and s. hemitoechus, whereas that of s. hundsheimensis cannot be supported. sus scrofa is the only suid species documented in the european middle pleistocene, it differs from the early pleistocene sus strozzii in several anatomical features, the most notable on wild boar remains from pm are the presence of a “scrofic” cross-section of male lower canines and the proportionally narrower teeth (iannucci et al., 2020a). the chronosubspecific repartition in a large-sized sus scrofa priscus eventually giving rise to a small-sized s. scrofa scrofa (e.g., fistani, 1996) seems a too simple interpretation of a more complex pattern, with several dimensional shifts occurred during the pleistocene (lister et al., 2010; iannucci et al., 2020b). two taxa are here identified for the first time: castor fiber and lepus sp. the european beaver is documented only by a partial hemimandible, which possesses features falling in the variability of the extant specimens of c. fiber (komosa et al., 2007; nowicki et al., 2019). in addition, the specimen is similar to those reported from cuenca-bescos et al. (2017) from several spain pleistocene deposits, with a lower first molar squared in shape in occlusal view, both mesial and posterior sides planar, less brachyodont chewing teeth and lacking fossettids (isolated enamel islands on the occlusal surface). few fragmentary postcranial elements can be attributed to hare. lack of clear diagnostic features prevents a specific attribution. carnivorans at pm are quite scarce. portis (1909) 145 ponte molle: a middle pleistocene mammal assemblage fig. 9 m3 length (mm) of bos primigenius from middle pleistocene sites of europe and subfossil specimens of bos taurus. colors: orange early middle pleistocene: pl, punta lucero; cmi, casa minniti; cc, contrada cozze; ma, malagrotta; red pm, ponte molle; light blue late middle pleistocene: idr, igue des rameaux-amont; pa, payre; lv, lunel-viel; fs, fara sabina; il, ilford; pda, pech de l’azé ii; green subfossil specimens of bos taurus; ek, elvas-kreuzwiese; sl, silves-lix. number of specimens indicated in the brackets. 146 mecozzi b. et al. the last carnivoran species, reported only by capasso barbato et al. (1998) (tab. 1), is crocuta crocuta. an upper third premolar and a replica of coprolite can be assigned to the spotted hyaena. the p3 is squared in shape in occlusal view, its labial margin is quite straight and the lingual cingulum is absent; distal accessory cusp is connected to the paracone with a weak crest. these features resemble those of c. crocuta, and differ from those of hyaena prisca (=pliocrocuta perrieri). two additional carnivorans, an ursid and a large felid, were reported by previous works (tab. 1). nevertheless, no fossils of the must sample can be attributed to these taxa, thus their presence at pm cannot be confirmed. similarly, to large-sized deer, we cannot exclude that additional fossils could be stored in other repository, as the scientific cabinet of high schools of rome or the monastery of santa scolastica in subiaco (rome). finally, considering the misadventures suffered by the paleontological collection of must during the 1900 century, we cannot exclude that part of the sample from pm has been destroyed. 5.4. biometry of selected taxa the biometric comparison of the m3 of b. primigenius from middle pleistocene european sites highlights no chronological or geographical trend (fig. 9). in particular, the rich sample from pm (21 specimens) shows a large variability, which encompasses that of the fossil specimens from middle pleistocene sites of europe. subfossil samples of b. taurus include specimens with shorter m3. the length of m3 of the fossil samples belonging to the fallow deer lineage shows a large variability (fig. 10). the sample from pirro nord displays the smallest size among the considered samples, well different from the other contemporaneous materials (late early pleistocene). no great difference can be detected among the fossil taxa, which generally possess a longer m3 than the extant italian specimens of d. dama dama. it is noteworthy that the two smallest samples in figure 10 are from pirro nord and contrada monticelli sites, both geographically located in the apulian peninsula (southern italy), which represent the southern margin of their geographical range. the biometric comparison of s. scrofa m3 length also shows a large variability, with no clear chronological or geographical trend identifiable (fig. 11). middle pleistocene specimens are on average larger than the extant fig. 10 m3 length (mm) of medium-sized deer from late early pleistocene to late middle pleistocene sites of europe and extant specimens. colors: orange pseudodama group: pr, pirro nord; ka, kalamotó; sp, saint-prest; eh, erpfinger höhle; va, le vallonnet; cv, cueva victoria; at8, atapuerca td8; light blue dama roberti: pa, pakefield; we, westbury; wr, west runton; cm, contrada monticelli (dama cf. roberti); vl, valdemino; red pm, ponte molle; purple: dama clactoniana; ca, caune de l’arago (dama cf. clactoniana); fr, fontana ranuccio; vi, visogliano; no, notarchirico; gt, grays thurrock; ja, jarwick; at11, atapuerca td11; green ex, extant specimens of dama dama dama. number of specimens indicated in the brackets. 147 ponte molle: a middle pleistocene mammal assemblage italian populations, and the sample of late pleistocene mis 4 and mis 2 apulian sites is the only one markedly smaller. remains from pm are among the largest of the european middle pleistocene. the plot of the m3 of fossil and extant hippos reveals differences between the groups: h. antiquus which generally has longer teeth. h. ex gr. antiquus, fossil and extant h. amphibius are characterized by reduced dimensions (fig. 12). 6. discussion 6.1. the age of the deposit from the stratigraphic analysis, the fauna from cava d’alessandri can be attributed to the lower gravelly level of the valle giulia formation. this formation is chronologically constrained by two radiometrically well dated ignimbrites, i.e. at the base by the 550 ka old via tiberina unit and on the top by the 449 ka “tufo rosso a scorie nere sabatino”. on the basis of the detailed sedimentological reconstruction of the internal architecture of the pm-tor di quinto fill terrace (sensu pazzaglia, 2013), it is excluded that the basal gravels of pm (“cosiddette ghiaie diluviali di ponte molle”) could be attributed to other fluvial formations older than the valle giulia formation. in fact, the fosso della crescenza and santa cecilia formations in the study area are very different from the basal gravels, being represented by prevailing sand and silt. this suggests, for this restricted area, the occurrence of different facies for the different formations (or portions of them) to be correlated to diverse depositional environments: gravelly-dominated braided river environment for the basal valle giulia formation; sanddominated meandering-style river environment for the fosso della crescenza-santa cecilia formations (fig. 5). 6.2. biochronological implications the revision of the geological and stratigraphic data indicates a time deposition between 540 and 460 ka for the mammal faunal assemblage from pm, which confirms a middle pleistocene age for the deposit. among mammals identified in the must sample, several species provide further biochronological insights. the first group considered is rhinocerotidae, with two species recorded: stephanorhinus kirchbergensis and s. hemitoechus. stephanorhinus kirchbergensis is poorly documented in italy, but in addition to pm this species was recorded from the middle pleistocene sites of visogliano (mis 13-10) (pandolfi, 2013) and tor di quinto (mis 13) (pandolfi & marra, 2015). stephanorhinus hemitoechus can be considered an important marker as its earliest occurrence in europe is from an undefined site of campagna romana, approximately dated at about 0.5 ma (age estimated from the correlation of the encrusted pumice after texture and the geochemical analyses; pandolfi et al., 2013), and from the caune de fig. 11 m3 length (mm) of sus scrofa from middle pleistocene sites of europe and extant specimens. colors: light blue sus scrofa: wr, west runton; tr, trimingham; ky, kyparissia; ga, gajtan; br, bristie 1; ce, cerè; lv, lunel-viel; gt, grays thurrock; or, oreston; hu, hutton; me, melpignano; tp, torre del pagliaccetto; pe, petralona; ai, apulia interglacial (mis 5 and mis 3 apulian sites); ag, apulia glacial (mis 4 and mis 2 apulian sites); red pm, ponte molle; green ex, extant specimens of sus scrofa. number of specimens indicated in brackets. 148 mecozzi b. et al. l’arago, from levels chronologically referred to mis 14 (moigne et al., 2006). the second group with strong chronological implications is cervidae. the presence of d. clactoniana and c. elaphus eostephanoceros clearly indicates a middle pleistocene age. the clacton fallow deer (d. clactoniana) appears in several european localities during mis 11 (breda et al., 2013) but it is possible that its dispersal predates this age. indeed, in central italy an earlier occurrence may be that from the levels alfa and a of notarchirico (cassoli et al., 1999), whose interbedded reworked volcanic minerals have been recently dated between 658±9 ka and 612±5 ka (moncel et al., 2020; mecozzi et al., 2021b). the other cervid group, the red deer, is represented by two different subspecies: c. elaphus acoronatus and c. elaphus eostephanoceros. the first subspecies is represented by an isolated partial cranium and complete antler (fig. 7). in italy, the crownless red deer (c. elaphus acoronatus) is recorded from slivia to isernia fus (ca 850-550 ka) (e.g., palombo et al., 2001; petronio et al., 2011). its presence at pm is quite surprising, since it is the only taxon that would suggest an early middle pleistocene age. despite this, we need to consider that these fossils were collected during the end of 1800s and early decades of 1900s, during quarrying activity. moreover, this is one of those remains that are not accompanied by a historical label, and the possibility that it may have been recovered from an older deposit outcropping in the surrounding area should be taken into account. the other red deer, most common in the studied sample, is the eostephanoceros red deer (c. elaphus eostephanoceros) (fig. 7). this taxon was instituted by di stefano & petronio (1993) mainly considering the antler discovered at cava nera molinario (rome, central italy) and fontana ranuccio, localities chronologically ranging between about 500 400 ka (marra et al., 2018; strani et al., 2018). however, considering the chronostratigraphic revision carried out by marra et al. (2014, 2018), it seems that both subspecies are documented from deposits of the area of rome referred to mis 13, namely c. elaphus acoronatus from via flaminia km 8.2, and c. elaphus eostephanoceros from cava nera molinario) (see iannucci et al., 2021 for discussion). among the equids, of considerable interest is the presence of e. hydruntinus, whose evolutionary history was recently redefined by boulbes & van asperen (2019). the authors suggested a clear presence of this taxon in the european record since the late middle pleistocene (mis 11), with a possible first dispersal during mis 15. in italy, this taxon was considered as a marker of the aurelian large mammal faunal assemblage (late middle pleistocene, gliozzi et al., 1997). however, new findings from vallparadís section (level 11, evt3, dated later than 600 ka) (aurell-garrido et al., 2010; martínez et al., 2014) and quarry carpentier d’abbeville (dated and correlated with mis 15) (antoine et al., 2016) suggest an earlier dispersal of the regalìa ass (e. hydruntinus) in europe. the wild boar, s. scrofa, is scarcely represented during early middle pleistocene glacial stages, and the relatively large size of the remains recovered from pm is close to that of other findings referred to mis 13, mis 11 or mis 9 interglacials (fig. 11; iannucci et al., 2020b). other mammal taxa identified in the pm faunal assemblage indicate a middle pleistocene age, but with no clear chronological definition, among which h. ex gr. antiquus, e. mosbachensis, and c. cf. mosbachensis. finally, several species from pm provide no constraints, since they are characterized by a long chronological distribution (middle to late pleistocene or holocene), as p. antiquus, b. primigenius, s. scrofa, c. capreolus, c. fiber, c. crocuta, lynx sp. and m. meles. in this scenario, the faunal assemblage of pm could be referred to mis 13. 6.3. paleoenvironmental implications redefining the pm faunal assemblage provides important paleoenvironmental and paleoecological clues. indeed, the species represented constitute a faufig. 12 plot of outer length (ol) vs. anterior breadth (ab) of m3 of fossil and extant hippos. 149 ponte molle: a middle pleistocene mammal assemblage nal assemblage typical of middle pleistocene interglacials of italy (strani et al., 2018). the presence and relative abundance of p. antiquus, h. ex gr. antiquus, c. elaphus eostephanoceros, d. clactoniana, s. scrofa and b. primigenius indicate warm and humid climatic conditions. this could be also true for hemibos galerianus, ancestral to the bubalus lineage (petronio & sardella, 1998; martinez navarro et al., 2011), considering the occurrences and plausible ecological preferences of the extinct buffalo (koenigswald et al., 2019). nonetheless, the mix of taxa adapted to different environments suggests the presence of a mosaic of open spaces (e.g. rhinos and equids) and woodlands (e.g. cervids and s. scrofa). other ecological and paleoenvironmental information can be inferred from the biometric comparisons of s. scrofa and d. clactoniana. in fact, even though these species are greatly chronologically and geographically variable (lister et al., 2010; van der made et al., 2014; di stefano et al., 2015; iannucci et al., 2020a; stefanelli & mecozzi, 2020), shifts in size can be influenced by ecological factors (geist, 1971, 1987; lindstedt & boyce, 1985; weinstock, 1997). focusing on a temporal and chronologically wellconstrained sample, iannucci et al. (2020b) recognized several size shifts experienced by s. scrofa during the late middle pleistocene to early holocene of apulia in southern italy, with smaller population occurring during glacial stages. they suggest an indirect triggering role of climate, in reducing the availability of trophic resources. even though more data are needed to substantiate this hypothesis and elucidate its geographical constraints, s. scrofa remains from the middle pleistocene of the area of rome are scanty but usually largesized (fig. 11), and thus fit well with what expected for interglacial stages in the mediterranean area. the very small size of the fallow deer of pm is also interesting though puzzling to interpret. indeed, according to weinstock (1997) the more severe winters of glacial stages should cause a strong decrease of the food supply and lead to a higher mortality rate. this leads to a decrease of the intraspecific competition during the following growth season (guthrie, 1984), which implies a higher quality and quantity of food resources (weinstock, 1997). therefore, glacial and interglacial size fluctuations in cervids should be observed. nevertheless, the dimensions of the late early to middle pleistocene european samples do not support this separation (fig. 10). it is possible that this reflects a different ecological adaptation in the species, which would be worth to be investigated in future research. 7. conclusions the large mammal faunal assemblage from ponte molle is dominated by bos primigenius, with palaeoloxodon antiquus, hippopotamus ex gr. antiquus, cervus elaphus eostephanoceros and equus mosbachensis well represented (tab. 1). the carnivorans are documented by a few taxa, all represented by a limited sample. aside from a few spurious holocene specimens, most of the faunal elements are consistent with an attribution to a single assemblage, which best fits within the fontana ranuccio fu. the historical background and geological constraints also support the view that the recovery of fossil remains from the area of pm was concentrated in the valle giulia formation, which is dated between 540 ka and 460 ka. even though we cannot exclude that a few specimens may have been misreported or mixed from different layers, an age older than 550 ky seems highly unlikely, as no formation of such an old age is documented in the area. moreover, the presence or relative abundance of species usually widespread during warm periods, such as b. primigenius, p. antiquus, h. ex gr. antiquus, c. elaphus eostephanoceros and d. clactoniana, is also suggestive of an interglacial environment. the reassessment of the classical fauna from pm, and the re-description of the sections of cava d’alessandri, torretta di quinto, and acquatraversa will serve as a basis for reinterpreting other historical and recent collections of the area of rome, as well as providing new data for our understanding of middle pleistocene mammal assemblages of europe. acknowledgements the study has been supported by sapienza research grants, “fondi grandi scavi” 2020 (sa120172b2c05e68) (project leader: prof. r. sardella) and by the cnr dta.ad003.316. project “sistemi terrazzati e valli incise: ricostruzioni stratigrafiche e loro implicazioni per la valutazione dei geohazard” (project leader: dr m. mancini). we wish to thank to l. riti and m. macri for the access to the fossil collection of the “museo universitario di scienze della terra” (must), department of earth sciences, sapienza, university of rome, and support during its study. we are also grateful to all curators and staff members of the other institutions visited during this research, d. arbulla (civic museum of natural history, trieste), r. rocca (responsible of the project for the study of the archeological and paleontological material from cimitero di atella deposit, potenza) (national archeological museum of melfi). the authors wish to thank l. bellucci, f. bona, j. conti, d.a. iurino, i. mazzini and f. strani for their useful suggestions and support. finally, we wish to thank the editor, marco peresani, and two anonymous referees for comments and suggestions that greatly improved the manuscript. references ambrosetti p., bonadonna f.p. (1967) revisione dei dati sul plio-pleistocene di roma. atti accademia gioenia di scienze naturali in catania, 18, 33-70. angellelli f. (1981) cenni preliminari sulla fauna quaternaria di fara sabina (rieti) conservata nel museo del servizio geologico d’italia. bollettino del servizio geologico d'italia, 102, 3-12. antoine p., moncel m.h., limondin-lozouet n., locht j.l., bahain j.j., moreno d., voinchet p., auguste p., stoetzel e., dabrowski j., bello s.m., parfitt s.a., trombret o., hardy b. (2016) palaeoenvironment and dating of the early acheulean localities from the somme river basin (northern 150 mecozzi b. et al. france): new discoveries from the high terrace at abbeville-carriere carpentier. quaternary science reviews, 149, 338-371. doi: 10.1016/j.quascirev.2016.07.035 athanassiou a., michailidis d., vlachos e., tourloukis v., thompson n., harvati k. (2018) pleistocene vertebrates from the kyparíssia lignite mine, megalopolis basin, s. greece: testudines, aves, suiformes. quaternary international, 497, 178-197. aurell-garrido j., madurell-malapeira j., alba d.m., moyà-solà s. (2010) the stenonian and caballoid equids from the pleistocene section of vallparadís (terrassa, catalonia, spain). cidaris, 30, 61-66. azanza b., sanchez b. (1990) les cervidés du pléistocene moyen d'atapuerca (burgos, espagne). quaternaire, 1(3-4), 197-212. ballatore m., breda m. (2013) stephanorhinus hundsheimensis (rhinocerontidae, mammalia) teeth from the early middle pleistocene of isernia la pineta (molise, italy) and comparison with coeval british material. quaternary international, 302, 169 -183. billia e.m., petronio c. (2009) selected records of stephanorhinus kirchbergensis (jäger, 1839) (mammalia, rhinocerotidae) in italy. bollettino della società paleontologica italiana, 48(1), 21-32. bökönyi s. (1970) a new method for determination of the number of individuals in animal bone material. american journal of archaeology, 74, 291-292. boschin f. (2018) animal remains from the multilayered site of elvas-kreuzwiese pf 574 (south tyrol, italy). annalen des naturhistorischen museums in wien. serie a für mineralogie und petrographie, geologie und paläontologie, anthropologie und prähistorie, 120, 195-210. boulbes n., van asperen e.n. (2019) biostratigraphy and palaeoecology of european equus. front. ecol. evol., 7, 301. doi: 10.3389/fevo.2019.00301 breda m. (2015) the early middle pleistocene fallow deer dama roberti new insight on species. geological journal, 50, 257-270. breda m., lister a. (2013) dama roberti, a new species of deer from the early middle pleistocene of europe, and the origins of modern. quaternary science reviews, 69, 155-167. bridge j.s. (2003) rivers and floodplains. forms, processes, and sedimentary record. blackwell publishing, oxford, pp. 491. caloi l., palombo m.r. (1978) anfibi, rettili e mammiferi di torre del pagliaccetto (torre in pietra, roma). quaternaria, 20, 315-428. caloi l., palombo m.r. (1979) resti di mammiferi del pleistocene medio di malagrotta (roma). bollettino del servizio geologico italiano, 100, 141-188. caloi l., palombo m.r. (1986) le mammalofaune pliopleistocene dell’area laziale: problemi biostratigrafici ed implicazioni paleoclimatiche. memorie del servizio geologico italiano, 35, 99-126. capasso barbato l., di stefano g., petronio c.,sardella r. (1998) pleistocene mammal faunas from ponte molle (rome). quaternary international, 47/48, 73-75. cassoli p.f., segre a.g. (2004) bubalus murrensis berk. nel pleistocene romano. quaternaria nova, 7, 129-138. cassoli f., di stefano g., tagliacozzo a. (1999) i vertebrati dei livelli superiori (alfa ed a) della serie stratigrafica di notarchirico. in: notarchirico: un sito del pleistocene medio iniziale nel bacino di venosa (ed. by piperno m.). edizioni osanna, venosa, italia, 361-438. cavarretta g., cavinato g.p., mancini m., moscatelli m., patera a., raspa g., stigliano f., vallone r., folle d., garbin f., milli s., storoni ridolfi s. (2005) i terreni di roma sotto l’aspetto della geologia tecnica. in: la iv dimensione. lo spazio sotterraneo di roma. (ed. by gisotti g., pazzagli g., garbin f.). geologia dell’ambiente, suppl. 4/2005, 33-46. ciotoli g., stigliano f., mancini m., marconi f., moscatelli m., cavinato g.p. (2015) geostatistical interpolators for the estimation of the geometry of anthropogenic deposits in rome (italy) and related physical-mechanical characterization with implications on geohazard assessment. environmental earth sciences, 74, 2635-2658. collinson j., mountney n., thompson d. (2006) sedimentary structures. third edition. terra publishing, edinburgh, pp. 292. conato v., esu d., malatesta a., zarlenga f. (1980) new data on the pleistocene of rome. quaternaria, 22, 131-176. cosentino d., cipollari p., di bella l., esposito a., faranda c., giordano g., gliozzi e., mattei m., mazzini i., porreca m., funiciello r. (2009) tectonics, sea-level changes and palaeoenvironments in the early pleistocene of rome (italy). quaternary research, 72(1), 143-155. davis s. j., gonçalves m.j., gabriel s. (2008) animal remains from a moslem period (12th/13th century ad) lixeira (garbage dump) in silves, algarve, portugal. revista portuguesa de arqueologia, 11 (1), 183-258. de lumley h., kahlke h.-d., moigne a.m., moulle p.e. (1988) les faunes des grands mammiferes de la grotte du vallonnet, roquebrune-cap-martin, alpes -maritimes. l’anthropologie, 92(2), 465-496. de rita d., funiciello r., corda l., sposato a., rossi u. (1993) volcanic units. in: sabatini volcanic complex (ed. by di filippo m.), consiglio nazionale del le ricerche, proget to final izzato “geodinamica” monografie finali, 11, 33-79. de stefani c. (1904) gli strati subterrestri della cava mazzanti al ponte molle. atti della reale accademia dei lincei, rendiconti classe di scienze fisiche, matematiche e naturali geologia, 13, 319325. di stefano g. (1994) il daino pleistocenico dell’eurasia. phd thesis, sapienza, university of rome, pp. 270. di stefano g., petronio c. (1992) nuove osservazioni su cervus elaphus acoronatus beninde del pleistocene europeo. bollettino della società paleontologica italiana, 31(3), 295-315. di stefano g., petronio c. (1997) origin and evolution 151 ponte molle: a middle pleistocene mammal assemblage of the european fallow deer (dama, pleistocene). neues jahrbuch für geologie und paläontologie, 203, 57-75. di stefano g., petronio c., sardella r. (1998) biochronology of pleistocene mammal faunas from rome urban area. il quaternario, 11, 191-199. di stefano g., pandolfi l., petronio c., salari l. (2015) considerations on the morphometry and the occurrence of cervus elaphus (mammalia, cervidae) from the late pleistocene of the italian peninsula. rivista italiana di paleontologia e stratigrafia, 121, 1-18. driesch von den a. (1976) a guide to the measurement of animal bones from archaeological sites. peabody museum bulletin 1, 1-136. fabiani r. (1919) i mammiferi quaternari della regione veneta. memorie dell’istituto geologico universitario di padova, 5, 1-174. fabiani r., maxia e.c. (1953) l’istituto e i musei di geologia e palentologia. pubblicazione istituto di geologia e paleontologia di roma, 9, 1-31. fistani a.b. (1996) sus scrofa priscus (goldfuss, de serres)(mammalia, artiodactyla, suidae) from the middle pleistocene layers of gajtan 1 site, southeast of shkodër (north albania). annales de paléontologie, 82, 177-229. funiciello r., giordano g. (2008a) carta geologica d’italia alla scala 1:50.000, foglio 374 roma. apat, dipartimento difesa del suolo, servizio geologico d’italia. funiciello r., giordano g. (2008b) note illustrative della carta geologica d’italia alla scala 1:50.000, foglio 374 roma. apat, dipartimento difesa del suolo, servizio geologico d’italia, pp. 158. funiciello r., giordano g. (2010) the colli albani volcano. iavcei special publication, n. 3, pp. 400. funiciello r., rosa c. (1995) l’area romana e lo sviluppo delle ricerche geologiche. in: funiciello r. (ed.) la geologia di roma. il centro storico. memorie descrittive della carta geologica d’italia, 50, 23-29. geist v. (1971) mountain sheep: a study in behavior and evolution. university of chicago press, chicago, pp. 383. geist v. (1987) bergmann’s rule is invalid. canadian journal of zoology, 65, 1035-1038. gibling m.r. (2006) width and thickness of fluvial channel bodies and valley fills in the geological record: a literature compilation and classification. journal of sedimentary research, 76, 731-770. giordano g., esposito a., de rita d., fabbri m., mazzini i., trigari a., rosa c., funiciello r. (2003) the sedimentation along the roman coast between middle and upper pleistocene: the interplay of eustatism, tectonics and volcanism. new data and review. il quaternario, 16(1bis), 121-129. giustini f., brilli m., mancini m. (2018) geochemical study of travertines along middle-lower tiber valley (central italy): genesis, palaeo-environmental and tectonic implications. international journal of earth sciences, 107, 1321-1342. gliozzi e., abbazzi l., argenti a., azzaroli a., caloi l., capasso barbato l., di stefano g., esu d., ficcarelli g., girotti o., kotsakis t., masini f., mazza p., mezzabotta c., palombo m.r., petronio c., rook l., sala b., sardella r., zanalda e., torre d. (1997) biochronology of selected mammals. molluscs and ostracodes from the middle pliocene to the late pleistocene in italy. the state of the art. rivisita italiana di paleontologia e stratigrafia, 103 (3), 369-388 gómez-olivencia a., sala n., arceredillo d., garcía n., martínez-pillado v., rios-garaizar j., garate d., solar g., libano, i. (2015) the punta lucero quarry site (zierbena, bizkaia): a window into the middle pleistocene in the northern iberian peninsula. quaternary science reviews, 121, 52-74. grayson d.k. (1984) quantitative zooarchaeology: topics in the analysis of archaeological faunas. academic press, orlando, pp. 202. guérin c. (1980) les rhinocéros (mammalia, perissodactyla) du miocène terminal au pléistocène supérieur en europe occidentale. comparaison avec les espèces actuelles. documents du laboratoire de géologie de lyon, 79, 1-1185. guérin c., dewolf y., lautridou j.p. (2003) révision d'un site paléontologique célèbre: saint-prest (chartres, france). geobios, 36(1), 55-82. guthrie r.d. (1984) mosaics, allelochemics, and nutrients: an ecological theory of late pleistocene megafaunal extinctions. in quaternary extinctions, a prehistoric revolution (ed. by martin p.s., klein r.g.). 259-298. iannucci a., gasparik m., sardella r. (2020b) first report of sus strozzii (suidae, mammalia) from the early pleistocene of hungary (dunaalmás) and species distinction based on deciduous teeth. the science of nature, 107, 5. iannucci a., sardella r., strani f., mecozzi b. (2020a) size shifts in late middle pleistocene to early holocene sus scrofa (suidae, mammalia) from apulia (southern italy): ecomorphological adaptations? hystrix, the italian journal of mammalogy, 31(1), 10-20. iannucci a., mecozzi b., sardella r. (2021) large mammals from the middle pleistocene (mis 11) site of fontignano 2 (rome, central italy), with an overview of “san cosimato” assemblages. alpine and mediterranean quaternary, 34(1), 155-164. igm (1936) castel giubbileo, f° 150 della carta d’italia a scala 1:25000, tavoletta iv no. istituto geografico militare, firenze. karner d.b., marra f., renne p.r. (2001) the history of the monti sabatini and alban hills volcanoes: groundwork for assessing volcani-tectonic hazards for rome. journal of volcanology and geothermal research, 107, 185-219 koenigswald w.v., schwermann a.h., keiter m., menger f. (2019) first evidence of pleistocene bubalus murrensis in france and the stratigraphic occurrences of bubalus in europe. quaternary international, 522, 85-93. komosa m., frąckowiak h., godynicki s. (2007) skulls of neolithic eurasian beavers (castor fiber l.) in comparison with skulls of contemporary beavers from natural biotopes of wielkopolska region 152 mecozzi b. et al. (polska). pol j environ stud, 16(5), 697-705. lehmann u. (1957) weitere fossilfunde aus dem ältesten pleistozän der erpfinger höhle (schwäbische alb). mitteilungen aus dem geologischen staatsinstitut in hamburg, 26, 60-99. leonardi g., petronio c. (1976) the fallow deer of european pleistocene. geologica romana, 15, 167. lindstedt s.l., boyce m.s. (1985) seasonality, fasting endurance, and body size in mammals. american nature, 125, 873-878. lister a.m., parfitt s.a., owen f.j., collinge s.e., breda m. (2010) metric analysis of ungulate mammals from the early middle pleistocene of britain, in relation to taxonomy and biostratigraphy. ii: cervidae, equidae and suidae. quaternary international, 228, 157-179. mancini m., marini m., moscatelli m., stigliano f., cavinato g.p., di salvo c., simionato m. (2018) stratigraphy of the palatine hill (rome, italy): a record of repeated middle pleistocene-holocene paleovalley incision and infill. alpine and mediterranean quaternary, 31(2), 171-194. manzi g., magri d., palombo m.r. (2011) early-middle pleistocene environmental changes and human evolution in the italian peninsula. quaternary science reviews, 30(11-12), 1420-1438. marra f., florindo f. (2014) the subsurface geology of rome: sedimentary processes, sea-level changes and astronomical forcing. earth-sciences reviews, 136, 1-20. marra f., karner d.b., freda c., gaeta m., renne p.r. (2009) large mafic eruptions at the alban hills volcanic district (central italy): chronostratigraphy, petrography and eruptive behaviour. journal of volcanology and geothermal research, 179, 217-232. doi: 10.1016/j.jvolgeores.2008.11.009. marra f., sottili g., gaeta m., giaccio b., jicha b., masotta m., palladino d.m., deocampo d. (2014) major explosive activity in the sabatini volcanic district (central italy) over the 800-390 ka interval: geochronological-geochemical overview and tephrostratigraphic implications. quaternary science reviews, 94, 74-101. doi: 10.1016/j.quascirev.2014.04.010. marra f., nomade s., pereira a., petronio c., salari l., sottili g., bahain j.j., boschian g., di stefano g., falguerès c., florindo f., gaeta m., giaccio b., masotta m. (2018) a review of the geologic sections and the faunal assemblages of aurelian mammal age of latium (italy) in the light of a new chronostratigraphic framework. quaternary science reviews, 181, 173-199. doi: 10.1016/j.quascirev.2017.12.007. martínez k., garcia j., burjachs f., yll r., carbonell e. (2014) early human occupation of iberia: the chronological and palaeoclimatic inferences from vallparadís (barcelona, spain). quaternary science reviews, 85, 136-146. doi: 10.1016/j.quascirev.2013.12.002 martínez-navarro b., palombo m.r. (2007) the horncore of hemibos galerianus from ponte silvio, rome (italy). rivista italiana di paleontologia e stratigrafia, 113, 531-534. martínez-navarro b., ros-montoya s., espigares m.p., palmqvist p. (2011) presence of the asian origin bovini, hemibos sp. aff. hemibos gracilis and bison sp., at the early pleistocene site of venta micena (orce, spain). quaternary international, 243 (1), 54-60. mazza p. (1995) new evidence on the pleistocene hippopotamuses of western europe. geologica romana, 31, 61-241. mazza p., bertini a. (2013) were pleistocene hippopotamuses exposed to climate-driven body size changes? boreas, 42, 194-209. mecozzi b. (2021) meles meles from middle pleistocene to early holocene of the italian peninsula within the evolution of european badgers in the quaternary of eurasia. palaeontographica, abt. a.: palaeozoology stratigraphy. doi: 10.1127/pala/2021/0100 mecozzi b., iurino d.a., profico a., rosa c., sardella r. (2020) the wolf from the middle pleistocene site of ostiense (rome): the last occurrence of canis mosbachensis (canidae, mammalia) in italy, historical biology. doi: 10.1080/08912963.2020.1769090 mecozzi b., sardella r., boscaini a., cherin m., costeur l., madurell-malapeira j., pavia m., profico a., iurino d.a. (2021a) the tale of a short-tailed cat: new outstanding late pleistocene fossils of lynx pardinus from southern italy. quaternary science reviews, 106840. doi: 10.1016/j.quascirev.2021.106840 mecozzi b., iannucci a., sardella r., curci a., daujeard c., moncel m.-h. (2021b) macaca ulna from new excavations at the notarchirico acheulean site (middle pleistocene, venosa, southern italy). journal of human evolution, 153. doi: 10.1016/j.jhevol.2020.102946 merrits d.j. (2007) terrace sequences. in: encyclopedia of quaternary sciences (vol. i) (ed. by elias s.a.). elsevier, netherlands, 694-704. milli s. (1997) depositional setting and high-frequency sequence stratigraphy of the middle-upper pleistocene to holocene deposits of the roman basin. geologica romana, 33, 99-136. milli s., palombo m.r., petronio c., sardella r. (2004) ‐ the middle pleistocene deposits of the roman basin (latium, italy): an integrated approach of mammal biochrology and sequence stratigraphy. rivista italiana di paleontologia e stratigrafia, 110, 557-567. milli s., moscatelli m., palombo m.r., parlagreco l., paciucci m. (2008) incised-valleys, their filling and mammal fossil record: a case study from middle-upper pleistocene deposits of the roman basin (latium, italy). geoacta, special publication, 1, 67-88. milli s., mancini m., moscatelli m., stigliano f., marini m., cavinato g.p. (2016) from fluvial to shelf, anatomy of a high-frequency depositional sequence: the late pleistocene-holocene tiber depositional sequence. sedimentology, 63, 1886 153 ponte molle: a middle pleistocene mammal assemblage 1928. moigne a.m., palombo m.r., belda v., heriech-briki d., kacimi s., lacombat f., de lumley m.a., moutoussamy j., rivals f., quilès j., testu a. (2006) les faunes de grands mammifères de la caune de l'arago (tautavel) dans le cadre biochronologique des faunes du pléistocène moyen italien. l'anthropologie, 110(5), 788-831. moncel m.h., santagata c., pereira a., nomade s., voinchet p., bahain j.j., daujeard c., curci a., lemorini c., hardy b., eramo g., berto c., raynal j.p., arzarello m., mecozzi b., iannucci a., sardella r., allegretta i., delluniversità e., terzano r., dugas p., jouanic g., queffelec a., d’andrea a., valentini r., minucci e., carpentiero l., piperno m. (2020) the origin of early acheulean expansion in europe 700 ka ago: new findings at notarchirico (italy). scientific reports, 10(1), 1-16. nowicki w., brudnicki w., kirkiłło-stacewicz k., skoczylas b., wach j. (2019) craniometric features of the population of european beaver (castor fiber l., 1758). slovenian veterinary research, 56(2), 43-52. palombo m.r. (1986) observations sur elephas antiquus falconer et cautley du pleistocène moyen d’italie: essai d’évaluation des caractères dentaires. geologica romana, 23 (1984), 99-110 palombo m.r. (1995) gli elefanti del pliocene superiore e del pleistocene dell’italia centrale peninsulare; alcune considerazioni. studi geologici camerti, vol. spec. 1994 (b), 447-458 palombo m.r. (2004) le mammalofaune della campagna romana: biocronologia, paleoambienti. ii congresso geosed, escursione precongresso, roma, 1-29. palombo m.r., azanza b., alberdi m.t. (2001) italian mammal bichronology from the latest miocene to the middle pleistocene: a multivariate approach. geologica romana, 36, 355-368. palombo m.r., anzidei a.p, arnoldus-huyzendveld a. (2003) la polledrara di cecanibbio: one of the richest elephas (palaeoloxodon) antiquus sites of the late middle pleistocene in italy. in: advances in mammoth research (proceedings of the second international mammoth conference, rotterdam, may 16-20 1999) (ed. by reumer j.w.f., de vos j., mol d.). deinsea, 9, 317-330. pandolfi l. (2013) rhinocerotidae (mammalia, perissodactyla) from the middle pleistocene site of ponte milvio, central italy. bollettino della società paleontologica italiana, 52(3), 219-229. pandolfi l., marra f. (2015) rhinocerotidae (mammalia, perissodactyla) from the chronostratigraphically constrained pleistocene deposits of the urban area of rome (central italy). geobios, 48(2), 147-167. pandolfi l., gaeta m., petronio c. (2013) the skull of stephanorhinus hemitoechus (mammalia, rhinocerotidae) from the middle pleistocene of campagna romana (rome, central italy): biochronological and paleobiogeographic implications. bulletin of geosciences, 88(1), 51-62. pazzaglia f.j. (2013) fluvial terraces. in: treatise on geomorphology 9 (ed. by wohl e.). academic press, san diego, california, 379-412. pereira a., nomade s., moncel m., voinchet p., bahain j., biddittu i., falguères c., giaccio b., manzi g., parenti f., scardia g., scao v., sottil g., vietti a. (2018) integrated geochronology of acheulean sites from the southern latium (central italy): insights on human-environment interaction and the technological innovations during the mis 11-mis 10 period. quaternary science reviews, 187, 112129. doi: 10.1016/j.quascirev.2018.03.021 petronio c., sardella r. (1998) bos galerianus n. sp. (bovidae, mammalia) from ponte galeria formation (rome, italy). neues jahrbuch für geologie und paläontologie, 5, 289-300. petronio c., sardella r. (1999) biochronology of the pleistocene mammal fauna from ponte galeria (rome) and remarks on the middle galerian faunas. rivista italiana di paleontologia e stratigrafia stratigrafia, 105(1), 155-164. petronio c., bellucci l., martiinetto e., pandolfi l., salari l. (2011) biochronology and palaeoenvironmental changes from the middle pliocene to the late pleistocene in central italy. geodiversitas, 33(3), 485-517. ponzi g. (1867) storia fisica del bacino di roma. atti accademia pontificia nuovi lincei, 20, 1-20. portis a. (1893) contributi alla storia fisica del bacino di roma e studii sopra l’estensione da darsi al pliocene superiore. volume 1. roux e c., torino/ roma, pp. 294. portis a. (1896) contributi alla storia fisica del bacino di roma e studii sopra l’estensione da darsi al pliocene superiore. volume 2. roux e c., torino/ roma, pp. 514. portis a. (1900) di una formazione stagnale presso la basilica di ostiense di roma e degli avanzi di fossili vertebrati in essa rinvenuti. bollettino della società geologica italiana, 19, 179-240. portis a. (1902) di un dente anomalo di elefante fossile e della presenza dell’elephas primigenius in italia. bollettino della società geologica italiana, 21, 93-114. portis a. (1907) di alcuni avanzi fossili di grandi ruminanti principalmente della provincia di roma. palaeontolographia italica, 13, 141-198. portis a. (1909) avanzi di canidi fossili dai terreni sedimento-tufacei di roma. bollettino della società geologica italiana, 28, 203-247. portis a. (1920) elenco delle specie cervicorni fossili in roma e attorno a roma. bollettino della società geologica italiana, 36, 130-139. ranzato g. (2019) la liberazione di roma. alleati e resistenza. editori laterza, bari, pp. 651. romano m., mecozzi b., sardella r. (2021) the middle pleistocene paleontological research in the campagna romana (central italy) at the 19th-20th century transition: an historical overview. alpine and mediterranean quaternary, 34(1), 109-129. stefanelli d., mecozzi b. (2020) body-mass estimation from middle pleistocene fallow deer of europe. 154 mecozzi b. et al. fossilia, volume 2020, 47-51. doi: 10.32774/fosreppal.2020.0613 stefanelli d., mecozzi b., francescangeli r., girone a., marino m., montenegro v., sardella r., breda m. (2021) the fallow deer from contrada monticelli (bari, southern italy): the southernmost occurrence of a large dama of the early middle pleistocene. bollettino società paleontologica italiana, 60,1. doi: 10.4435/bspi.2021.02 strani f., demiguel d., bona f., sardella r., biddittu i., bruni l., de castro a., guadagnoli f., bellucci l. (2018) ungulate dietary adaptations and palaeoecology of the middle pleistocene site of fontana ranuccio (anagni, central italy). palaeogeography, palaeoclimatology, palaeoecology, 496, 238-247. tellini a. (1893) carta geologica dei dintorni di roma. regione alla destra del tevere. cromolit. danesi, roma (scale 1:50.000). tsoukala e., chatzopoulou k. (2005) a new early pleistocene (latest villafranchian) site with mammals in kalamotó (mygdonia basin, macedonia, greece). preliminary report. mitt. komm. quartärforsch. österr. akad. wiss., 14, 213-233. tsoukala e., guérin c. (2016) the rhinocerotidae and suidae of the middle pleistocene from petralona cave (macedonia, greece). acta zoologica bulgarica, 68, 243-264. uzunidis-boutillier a. (2017) grands herbivores de la fin du pléistocène moyen au début du pléistocène supérieur dans le sud de la france. implications anthropologiques pour la lignée néandertalienne. phd thesis, aix-marseille university, pp. 797. van asperen e.n. (2012) late middle pleistocene horse fossils from northwestern europe as biostratigraphic indicators. journal of archaeological science, 39, 1974-1983 van asperen e.n. (2013) implications of age variation and sexual dimorphism in modern equids for middle pleistocene equid taxonomy. int. j. osteoarchaeol., 23, 1-12. doi: 10.1002/oa.1231 van der made j., stefaniak k., marciszak a. (2014) the polish fossil record of the wolf canis and the deer alces, capreolus, megaloceros, dama and cervus in an evolutionary perspective. quaternary international, 326, 406-430. van der made j., rosell j., blasco r. (2017a) faunas from atapuerca at the early-middle pleistocene limit: the ungulates from level td8 in the context of climatic change. quaternary international, 433, 296-346. van der made j., sahnouni m., boulaghraief k. (2017b) hippopotamus gorgops from el kherba (algeria) and the context of its biogeography. in: proceedings of the ii meeting of african prehistory: burgos 15-16 april 2015, 135-169. ventriglia u. (1971) la geologia della città di roma. amministrazione provinciale di roma, roma. ventriglia u. (2002) geologia del territorio del comune di roma. amministrazione provinciale di roma, roma. verri a. (1915) carta geologica di roma. regio ufficio geologico (scale 1:15.000). weinstock j. (1997) the relationship between body size and environment the case of late pleistocene reindeer (rangifer tarandus). archeofauna, 6, 123135. wright e. (2013) the history of the european aurochs (bos primigenius) from the middle pleistocene to its extinction: an archaeological investigation of its evolution, morphological variability and response to human exploitation. phd thesis, university of sheffield, pp. 324. ms. received: november 24, 2020 revised: january 25, 2021 accepted: may 16. 2021 avaiable online: april 14, 2021 https://doi.org/10.32774/fosreppal.2020.0613 il terremoto del 1905 in calabria: revisione della distribuzione degli effetti e delle ipotesi sismogenetiche paolo galli1,2 & diego molin1 1dipartimento della protezione civile nazionale, roma (paolo.galli@protezionecivile.it) 2cnr istituto di geologia ambientale e geoingegneria, roma riassunto: galli p. & molin d., il terremoto del 1905 in calabria: revisione della distribuzione degli effetti e delle ipotesi sismogenetiche. (it issn 0394-3356, 2009). il terremoto dell’8 settembre del 1905 è sempre stato un evento un po’ negletto dalla storiografia sismologica italiana, oscurato dagli effetti del catastrofico evento del 1908; eppure è il terremoto per il quale è stato calcolato il più alto valore strumentale della magnitudo in italia (tra ml=7.9 e ms=7.47). per questo lavoro sono state recuperate tutte le fonti già citate nei precedenti studi, oltre a molte altre sconosciute, tra cui una relazione ministeriale molto voluminosa, che nel complesso hanno permesso di ricostruire la distribuzione degli effetti per 895 località dell’italia meridionale in termini di scala mcs. il quadro che ne deriva è percettivamente diverso da quelli precedentemente delineati e permette di avanzare ipotesi in parte inedite sugli scenari sismogenetici della calabria. in particolare, 1) la grande estensione dell’area di danneggiamento, 2) l’apertura verso il tirreno del piano quotato, 3) l’insorgenza di un debole maremoto e la sua natura bipolare, 4) l’assenza del purché minimo indizio di fagliazione di superficie a terra, 5) e il confronto con la distribuzione degli effetti di altri terremoti profondi del basso tirreno ci conducono ad ipotizzare la presenza di una sorgente subcrostale nell’offshore del monte poro. abstract: galli p. & molin d., the 1905 earthquake in calabria: a review of effects distribution and of the seismogenetic hypotheses. (it issn 0394-3356, 2009). in the first hours of the night of september 8th, 1905, the villages of mt. poro (southern calabria) and many others along the tyrrhenian edge of calabria, were struck by the most powerful earthquake even occurred in italy (at least in terms of recorded magnitude: ml=7.9, dunbar et al., 1992; ms=7.47; margottini et al., 1993; gruppo di lavoro cpti, 1999), that caused around 600 casualties. in this paper, thanks to hundreds original sources collected in archives and library all over italy, but particularly to a huge, unpublished contemporary government report, we reevaluated the macroseismic intensity distribution (mcs scale) for 895 localities in southern italy (fig. 7; see details in galli and molin, 2007). the resulting framework of effects differs perceptively from those presented by previous authors, allowing to hypothesize an unedited hypothesis as far as the calabrian seismogenetic scenarios are concerned. firstly, the earthquake had a very large damage area, typical of deep event, the 7th mcs degree extending well beside 170 km in a nesw direction (fig. 8), that is more than the neighbour epochal earthquake of february 5, 1783. the maximum intensity reached 10-11 mcs in the mt. poro villages (fig. 1), but differently from the others strong apenninic earthquakes, in the mesoseismic area the highest intensities (10-11 mcs) alternated to very low effects (6-7 mcs). the macroseismic framework is also complicated by the presence of environmental effects (landslides and liquefaction, surficial breaks; figg. 10-12) affecting 25% of the damaged municipalities (85% of villages with is?10 mcs). on the other hand, microtremors analyses performed in the most damaged localities showed a scarce relationship between disruption level and frequency peaks falling in the range of engineering interest (i.e., suggesting low site amplification effects; fig. 13). from the seismogenetic point of view, no surficial trace of coseismic faulting have been observed in the mesoseismic area, notwithstanding the magnitude value would imply a source dimension (~50 km length) and a coseismic slip (> 1m) well detectable for a inland crustal structure (e.g. along the faults quoted in previous papers; see tortorici et al., 1995; galli and bosi, 2002; cucci and tertulliani, 2006). moreover, the intensity distribution is clearly opened toward the tyrrhenian sea, where along the coasts a weak tsunamis was also observed after the earthquake (figg. 8-9). therefore, 1) the very large damage extension, 2) the opening of isoseismal lines toward the sea, 3) the occurrence of a bipolar tsunamis, 4) the lack of inland surface faulting and 5) the comparable shape and effects distribution of others studied deep-tyrrhenian earthquakes (fig. 4) allow us to hypothesize the presence of a sub-crustal source in the mt. poro offshore, responsible for the 1905 event. in facts, it is well known that the calabrian arc is subducted by an active, ionian lithospheric slab that, in the offshore of the tyrrhenian coast dips ~70° toward nw. most of the slab seismicity (figg. 5-6) is due to down-dip compression mechanisms (events m>7 at depth > 150 km), but it is possible that also the hinge of the slab, due to flexural-extension processes, might release high values of magnitude, such the one recorded for the 1905 earthquake (fig. 14). parole chiave: terremoto, macrosismica, calabria, subduzione litosferica. keywords: earthquake, macroseismics, calabria, plate subduction. il quaternario italian journal of quaternary sciences 22(2), 2009 207-234 1. introduzione il terremoto della notte tra il 7 e l’8 settembre del 1905 interessò gran parte dell’italia meridionale, danneggiando quasi tutta la calabria e parte del messinese. la scossa principale fu accompagnata da un debole maremoto lungo le coste tirreniche calabresi e fu seguita da un periodo sismico composto da varie centinaia di eventi. questo terremoto è un evento “anomalo” nel contesto sismotettonico non solo della calabria, ma dell’intera catena appenninica, sia per la grande energia liberata e per la distribuzione irregolare degli effetti macrosismici, sia anche per la sua posizione rispetto alla principale fascia sismogenetica dell’arco appenninico-calabro. innanzitutto, la sua magnitudo è la più grande mai registrata strumentalmente in italia (ml=7.9, dunbar et al., 1992; ms=7.47, margottini et al., 1993; cpti99), maggiore di quella calcolata per il catastrofico evento di messina del 1908 (ms=7.32, margottini et al., 1993; cpti99). ebbe, poi, una vastissima distribuzione del danno, con intensità massime di x e x-xi grado mcs 1 (fig. 1); la sua estensione è con208 p. galli & d. molin frontabile solo con quella del terremoto del 1908, sebbene quest’ultimo colpì un patrimonio edilizio già fortemente compromesso dai danni prodotti, e in parte solo provvisoriamente riattati, dallo stesso evento del 1905 e da altri precedenti, tra cui quello del 16 novembre 1894 (io=viii-ix; vedi anche in baratta, 1909). nel terremoto del 1905 alla vastità del danneggiamento si sovrappone la complessa distribuzione degli effetti, in particolare nell’area mesosismica del monte poro. infatti, diversamente da terremoti caratterizzati da energia anche minore (p.e., 27 marzo 1638 e 5 febbraio 1783, entrambi con mw=6.9), nella supposta area epicentrale non si ebbe uniformità di danno, ma a paesi distrutti si alternarono altri con danni modesti (p.e., zungri, x mcs a soli 4 km da mesiano, vi-vii mcs). infine, a fronte dell’elevatissima energia associabile all’evento, non si segnalarono effetti di fagliazione di superficie, tantomeno nella presunta area epicentrale del monte poro. nel presente lavoro, a partire dal quadro sismogenetico regionale ed analizzando la distribuzione degli effetti di scuotimento (comprensivi dei possibuli effetti geologici di amplificazione) si cercherà di definire meglio i parametri del terremoto. a questo proposito, lo studio macrosismico dell’evento è stato sviluppato utilizzando nuove fonti, prevalentemente inedite, recuperate presso l’archivio centrale dello stato di roma e anche presso vari archivi della calabria 2 . dalle indagini svolte, emerge un quadro complessivo del terremoto percettibilmente differente da quello noto sino ad oggi, tanto da consentire di formulare un’ipotesi inedita relativamente alla sua possibile sorgente. 2. quadro sismotettonico della calabria 2.1 il contesto geodinamico secondo la vasta letteratura disponibile, nell’arco calabro sono contemporaneamente in atto processi di subduzione tra due placche litosferiche, di arretramento flessurale della cerniera di quella in subduzione, di sollevamento regionale, di estensione crostale nel settore tirrenico e compressione in quello ionico, di vulcanismo o f f s h o r e, oltre ad un altissimo livello di sismicità. strutturalmente, l’arco calabro è la terminazione meridionale della catena a pieghe e sovrascorrimenti appenninica e possiede, complessivamente, un’età eocenico-tortoniana (am o d i o mo r e l l i, et al., 1976). la sua messa in posto è stata condizionata dalla complessa interazione tra la placca africana e quella europea, a partire da quando una porzione del margine alpino (il futuro arco calabro-peloritano) è collisa sovrascorrendo sul margine africano (am o d i o mo r e l l i et al., 1976; van dijk & okkes, 1991; catalano et al.; 1993), venendone poi insieme subdotta da un paleo oceano ionico, le cui porzioni superstiti affiorano nello ionio centrale, tra i fronti delle ellenidi ed il prisma d’accrezione calabro (ca t a l a n o et al., 2000 e bibliografia citata). la migrazione verso se dell’arco calabro sopra la catena appenninica è avvenuta tramite elementi di svincolo caratterizzati da estese fasce di taglio a nord (linea di sangineto; amodio morelli et al., 1976. fascia nw-se del pollino; schiattarella, 1998) ed a sud (linea salinalipari-vulcano, tindari-letojanni e scarpata di malta, con cinematica trascorrente destra; tortorici, 1982). il processo di collisione tra le placche ha comportato la consunzione della litosfera oceanica ionica al di sotto dell’arco calabro in migrazione verso se, come testimoniato ancor oggi dalla presenza di uno slab in subduzione verso nw, ben delineato dal piano di benjoff associato (pe t e r s c h m i t t, 1956; am a t o et al., 1993). la geometria dello s l a b è comunque molto complessa, così come tra poco descritto. a occidente dello slab, in risposta al continuo arretramento flessurale verso se della cerniera della placca in subduzione, si è progres1le edizioni cpti99 (gruppo di la v o r o cpti, 1999; cpti04 e cpti08 le edizioni successive) e cpti04 forniscono un’intensità epicentrale io=xi mcs (imax=x-xi), mentre in cpti08 io=x mcs (imax=x mcs). tutte le indicazioni parametriche su terremoti contenute in questo lavoro si riferiscono alle diverse edizioni del cpti se non diversamente indicato. 2le schede sulle singole località, comprensive della descrizione degli effetti (per oltre un migliaio di pagine) sono consultabili su richiesta presso gli autori. fig. 1 a sinistra, la vecchia piazza di zammarò, frazione di san gregorio d’ippona, nei pressi di vibo valentia. la distruzione in questo paese è stata valutata pari al x-xi grado nella scala mcs, rappresentando la imax osservata per il terremoto. la vicina frazione di mezzocasale e san gregorio d’ippona stesso ebbero effetti valutabili all’viii mcs (foto e. navone). a destra, veduta delle rovine di piscopio, uno dei paesi maggiormenti danneggiati dal terremoto (is=x mcs). left panel; the old square of zammarò (san gregorio d’ippona, near vibo valentia). we assigned the maximum local intensity at this village (is=10-11 mcs). it is worth noting that the nearby villages of mezzocasale and san gregorio d’ippona had effects matching with 8 mcs. right panel; ruins of piscopio (is=10 mcs), near vibo valentia. sivamente aperto un bacino di retro-arco, il cui fondo oceanico palesa età via via più recenti verso se (bacini di vavilov e marsili del tirreno meridionale, rispettivamente ~3.5 ma e ~1.8 ma; be c c a l u v a et al., 1990). contestualmente all’estensione tirrenica (da taluni considerata un vero e proprio processo di rifting: monaco e to r t o r i c i, 1995), a partire dal miocene superiore (moretti e guerra, 1997) il complesso sistema di sovrascorrimenti imbricati dell’arco calabro è stato anch’esso sottoposto a distensione crostale, manifestatasi principalmente con grandi faglie normali che, specialmente dalla fine del pleistocene inferiore, hanno guidato l’apertura di bacini n-s e ne-sw (gh i s e t t i, 1981; to r t o r i c i et al., 1995; ga l l i e bo s i, 2002 e 2003), sia lungo il settore interno dell’arco (bacini del crati, del mesima, di gioia tauro e dello stretto di messina), che nel settore ionico (bacino di crotone). a partire almeno dal pleistocene medio, la calabria è andata soggetta ad un rapido processo di sollevamento, con ratei medi di 0.6 mm/a a nord, sino a 1.3 mm/a a sud (dumas e raffy, 2004), come testimoniato dall’impressionante scalinata di terrazzi marini che orlano gran parte delle coste calabre (mi y a u a c h i et al., 1994; ca r o b e n e, 2003; du m a s et al. , 2005) e di superfici sommitali relitte che rasano le cime dei massicci della calabria meridionale. 2.2 sismicità dell’arco calabro la sismicità della calabria è di livello molto elevato, non solo nel contesto della catena appenninica, ma anche dell’intero mediterraneo. a partire dall’evento che secondo strabone distrusse gran parte di reggio nel 91 a.c., ben altri venti terremoti con m>6.0 hanno colpito la regione. tuttavia, dall’analisi dei cataloghi sismici emerge che la quasi totalità di questi terremoti è, in realtà, limitata agli ultimi quattro secoli, con soli quattro eventi prima dell’anno mille e quindici tra il mille ed il milleseicento, mentre dei ventuno terremoti con mw>6.0, ben 16 sono concentrati in meno di 300 anni, tra il 1626 ed il 1908. in termini di energia liberata, tutto ciò equivale a dire che ben il 90% dell’energia liberata dalle sorgenti sismogenetiche calabresi negli ultimi ventuno secoli è apparentemente concentrata in meno di tre. di fatto, quello che accadde in calabria tra il 1638 ed il 1908 è stata una sequenza sismica senza paragoni, almeno nell’ultimo millennio. ricerche effettuate in diversi archivi calabresi, nell’archivio di stato di napoli, in quello segreto vaticano e tra le fonti “giornalistiche” dell’epoca hanno confermato questa ipotesi (camassi e castelli, 2004; scionti e galli, 2005); di fatto, a parte notizie riguardanti un evento sconosciuto di elevata energia (m=6.2), avvenuto nel 1744 nel crotonese (scionti et al., 2006), non è emerso null’altro di paragonabile a ciò che accadde dopo il ‘600. resta, ovviamente, il ragionevole dubbio su ciò che potrebbe essere accaduto nei primissimi secoli del secondo millennio e nel corso dell’intero primo millennio, entrambi oggettivamente avari o mancanti del tutto di fonti. quello che sappiamo in più rispetto alle tradizionali fonti storiche riguardo alla sismicità pregressa proviene, invece, da analisi di carattere paleosismologico ed archeosismologico che hanno permesso di individuare una serie di grandi terremoti (mw≥6.5) generati dalle faglie investigate e “gemelli”, in alcuni casi, di terremoti devastanti avvenuti in epoca moderna. tra questi, quelli che precedettero l’evento del 9 giugno 1638 209il terremoto del 1905 in calabria: revisione della distribuzione ... in sila all’alba del ii e del i millennio a.c., ripetutosi nuovamente in epoca bizantina (vii secolo; ga l l i e bo s i, 2003; ga l l i et al., 2007); o quello del iv secolo d.c. avvenuto sulla stessa faglia che generò la catastrofe del 5 febbraio 1783, identificabile con un evento mal definito in catalogo (poco prima del 374 d.c.; ga l l i e bo s i, 2002): od altri nella zona del monte pollino, attualmente considerata pressoché asismica, ma soggetta nel iv millennio a.c. e nell’alto medioevo (600-900 d.c.) a due forti terremoti (michetti et al., 1997; cinti et al., 2002); o, infine, quello che distrusse l’antico insediamento romano di capo colonna (crotone) nella metà del iii secolo d.c. (galli et al., 2006a). quello che è possibile evincere allo stato delle attuali conoscenze (fig. 2) è che gran parte della sismicità della calabria si concentra lungo il versante tirrenico della penisola. nella stretta di sibari ed a nord della stessa, a meno degli eventi paleosismici legati alla faglia del monte pollino, la sismicità è pressoché assente (stretta e versante ionico) o di basso livello (fascia castrovillari-lagonegro; ga l l i et al., 2001). i primi grandi terremoti si incontrano lungo la fascia pedemontana della sila settentrionale, nella zona di rossano con gli eventi del 951 e, soprattutto, del 1836 (mw=6.2; io=x mcs; galli et al., 2009). la media valle del crati è, invece, sede “storica” di una lunga sequenza che, a partire da fine settecento, nell’arco di un secolo, ha colpito duramente i paesi di entrambi i versanti da nord verso sud (1767, 1835, 1854, 1870, tutti con x≥i o≥viii-ix mcs). questa sequenza, caratterizzata da eventi con magnitudo prossima a 6, ha avuto un catastrofico prodromo il 27 marzo del 1638, quando un terremoto di mw=6.8 (io=xi mcs) devastò i bacini dell’alto crati e del savuto. esiste poi un forte evento datato al 1184, attualmente posto in valle del crati, ma con un’area di danneggiamento mai appieno definita, a causa della scarsità delle fonti medievali. un’altra fascia fortemente sismica si estende in direzione nw-se dall’interno del massiccio silano alla zona di crotone. ai forti terremoti storici del 9 giugno 1638 (mw=6.8; io=ix-x mcs; ga l l i e bo s i, 2003), del 1744 (mw=6.2; io=ix mcs; sc i o n t i et al., 2006) e del 1832 (mw=6.6; io=ix-x mcs, ga l l i et al., 2009), si aggiungono altri eventi derivati da analisi paleo/archeosismiche, sia relativi alla struttura del 1638 (faglia dei laghi; galli et al., 2007), che alla zona di capo colonna (galli et al., 2006a). la stretta di catanzaro è sede di una sismicità devastante, culminata con gli eventi del 28 marzo 1638 (mw=6.6; io=xi mcs; ga l l i e bo s i, 2003) e del 28 marzo del 1783 (mw=6.9; io=x mcs). il primo concorse alla distruzione totale dei paesi sul versante sudoccidentale della sila (lametino), mentre il secondo atterrò tutti i paesi del versante nordorientale delle serre. furono preceduti da altri eventi con m>5.5 tra fine ‘500 e primi del ‘600 (1599, 1609, 1626; scionti et al., 2006), che dettero inizio, in un certo qual modo, alla grande sequenza sismica conclusasi nel 1908. la calabria meridionale è caratterizzata da un’elevatissima sismicità sia lungo tutto il versante tirrenico delle serre – con i terremoti del 1659 (mw=6.5; io=x mcs), 1743 (mw=5.9; io=viii mcs; scionti et al., 2006) e 1783 (7 febbraio mw=6.6, io=x-xi), tutti a nord e sud di soriano calabro sia lungo quello dell’aspromonte 210 con l’evento epocale del 5 febbraio 1783 (mw=6.9; io xi mcs), i suoi “gemelli” paleosismici (p.e., ~372 d.c.; ga l l i e bo s i, 2002) ed i terremoti del 1894 (mw=6.0; io=viii-ix) e del 1928 (mw=5.9; io=vii-viii). per quanto riguarda il terremoto di reggio del 91 a.c., citato da strabone, nulla si può dire riguardo la sua reale localizzazione epicentrale e la distribuzione degli effetti, sebbene compaia in cpti04 con io=ix-x e maw=6.3 (e con le coordinate epicentrali di reggio calabria). e’ tuttavia importante notare che nell’area mesosismica del 1905, a vibo valentia, è stata di recente rinvenuta una lapide che attesta restauri alle mura romane della città nel corso del i secolo a.c. (sangineto, 1989). e’ possibile che tali restauri si riferiscano agli effetti di qualche evento sismico piuttosto che a riparazioni per vetustà (la deduzione della colonia romana a vibo e la costruzione delle mura urbiche era avvenuta solo il secolo precedente), configurando il terremoto del 91 a.c. come uno dei possibili candidati. infine, sempre in calabria meridionale, ma con incerta posizione epicentrale, hanno avuto origine i due più forti terremoti mai occorsi in italia peninsulare, nel 1905 e nel 1908 (mw=7.3; io=xi mcs). entrambi questi eventi generarono un maremoto, quello del 1908 dagli effetti devastanti lungo le coste settentrionali della sicilia orientale e della calabria a sud dello stretto (platania, 1909). gli effetti di quello del 1905, di entità molto minore, saranno invece descritti più avanti. quello che si nota, inoltre, dalla fig. 2 è che il monte poro-capo vaticano, ovvero l’area più danneggiata dal terremoto del 1905, non contiene al suo interno né terremoti ad esso paragonabili, né altri eventi degni di nota, ad eccezione di quello del 1928 (fig. 3), tra poco descritto. le località del monte poro non hanno inoltre mai subito estese distruzioni, neppure ad opera di terremoti con origine esterna all’area. si pensi a tropea, una della città con una storia documentaria più ricca e continua di tutta la calabria negli ultimi mille anni, che oltre ai risentimenti dovuti ai forti eventi già descritti del 1638, 1783 e 1908, ha subito moderati danni solo nel 1687 a causa di un terremoto di presunta origine locale, (io=is=vii mcs). vibo valentia stessa, seppur molto prossima alle strutture sismogenetiche dei terremoti devastanti del 1783 e 1659 (per i quali non ebbe a soffrire più di un viii mcs), ha subito solo lievi danni in occasione di terremoti di possibile origine locale, come quelli del 1869 e 1735 (vi-vii mcs). il terremoto del 1928 (ms=5.85, fig. 3), che danneggiò seriamente sia sant’onofrio (viii mcs), che gioia tauro, mileto, seminara e soriano (vii-viii mcs), fu caratterizzato da un’area di risentimento vastissima (il vii mcs si estese, seppur in modo assai discontinuo, per oltre 70 km, tra lo ionio ed il tirreno. dati inediti degli scriventi). cavasino (1935), valutando la distribuzione della massime intensità aperta verso il tirreno, ne pone l’epicentro tra stromboli e capo vaticano. di certo, vista la distribuzione degli effetti e la loro vastità ed intensità, il terremoto ebbe un’origine profonda (p.e., 40 km; po s t p i s c h l, 1985; 100 km in pe t t e r s c h m i t, 1956), analogamente a quanto potrebbe essere accaduto nel 1905. si riporta, infine, il caso del terremoto del 13 aprile 1938, molto profondo (~290 km), ma che a causa della grande energia liberata (mb=7.1) fu ugualmente risentito in una vasta area della calabria e della sicilia (vedi fig. 2 distribuzione degli epicentri dei terremoti con mw>5 modificati da cpti04 e relative date. con una diversa campitura sono rappresentati gli eventi provenienti da ricerche archeosismiche ed analisi paleosismologiche (vedi testo). il terremoto del 1905 è riportato nella posizione ipotizzata in questo lavoro. le linee corrispondono a strutture sismogenetiche primarie (a tratto più spesso quelle investigate tramite tecniche paleosismologiche ed alle quali sono state sicuramente attribuiti i principali terremoti storici, oltre ad altri preistorici). 1, faglia del m. pollino; 2, faglie del crati; 3, faglia di rossano; 4, faglia del cecita; 5, faglia dei laghi; 6, faglia di piano lago-decollatura; 7, faglie di feroleto-sant’eufemia; 8, faglia delle serre; 9, faglia di cittanova; 10, faglie di armo-reggio calabria (mod. da galli e scionti, 2006). earthquakes distribution in calabria (mod. from cpti, 2004. mw>5.0; grey circle are paleoseismic events; see galli et al., 2008) and primary seismogenetic faults (bold certain, i.e. inves tigated by paleoseismological analyses). 1, mt. pollino fault; 2, w-crati fault system; 3, corigliano-calopezzati fault; 4, cecita fault; 5, lakes fault; 6, piano lago-decollatura fault; 7, catanzaro straits faults. 8, serre fault system; 9, cittanova fault; 10, reggio calabria fault system. agamennone, 1938; caloi e giorgi, 1951). la fig. 4 ne mostra la distribuzione degli effetti che, rispetto all’epicentro strumentale calcolato da caloi e giorgi (1951) e an d e r s o n e ja c k s o n (1987) è molto sbilanciata verso sudest ed allungata in direzione ~ne-sw (dati inediti degli scriventi). lo scuotimento indotto da questo evento, originatosi ovviamente nella litosfera ionica in subduzione, sembra essere stato guidato e condizionato dalla geometria dello slab in profondità, così come discusso nei prossimi capitoli. p. galli & d. molin 211 2.2.1 sismicità da dati strumentali il quadro fornito dalle registrazioni strumentali negli ultimi 20 anni circa (catalogo della sismicità italiana 1981-2002, in seguito csi; ca s t e l l o et al. , 2 0 0 6 ) appare sostanzialmente differente da quello desumibile dalle ricerche storiche e dai dati paleosismologici. paradossalmente, osservando la distribuzione degli epicentri ripresi dal csi, è il massiccio silano, storicamente “silente” per eccellenza (e per mancanza di centri abitati!), a mostrare la maggiore densità di eventi nella regione (fig. 5a). in realtà, per un così breve periodo di osservazione, la distribuzione degli epicentri insegue sostanzialmente le diverse sequenze sismiche verificatesi nel frattempo, caratterizzate da moltissimi fores h o c k s ed a f t e r s h o c k s di bassa magnitudo legati agli eventi principali, anch’essi di bassa energia. e’ ben evidente, per esempio, la sequenza del settembre 1998 al confine calabro-lucano (mw=5.6; io=vii mcs), mentre più confusamente si individuano le sequenze della sila greca dell’aprile 1996 (mw=4.8; io=vi-vii) o altre nel cosentino, vibonese e reggino. ciò che mettono chiaramente in evidenza i sei pannelli della fig. 5 è l’esistenza di una sismicità molto profonda e geometricamente organizzata nel basso tirreno, prerogativa quasi esclusiva di questo tratto della catena appenninica. tale sismicità dipinge in profondità l’immagine della litosferica ionica in subduzione verso nw, come nel seguito descritto. 2.3 sismicità dello slab del basso tirreno la geometria dipinta dagli eventi profondi in sezione (fig. 6) restituisce l’immagine di un corpo che si immerge con un’elevata pendenza (circa 70°) proprio al di sotto della calabria e che già al di sotto dell’offshore di capo vaticano ha raggiunto i 200 km di profondità. lateralmente, il piano di benioff s.s. è limitato a non più di 200 km ed appare, nel settore settentrionale, interrotto tra i 100 ed i 200 km di profondità (fig. 6; vedi anche in chiarabba et al., 2005). la geometria in profondità dello slab è complessivamente ben delineata nello spazio dalla distribuzione regionale delle anomalie delle onde p (pi r o m a l l o e morelli, 2003): lo slab appare molto stretto (circa 170 km) al di sotto della calabria meridionale, a sud della stretta di catanzaro, allargandosi in profondità, al di sotto di 200-250 km, sotto l’appennino meridionale. qui i meccanismi focali disponibili in letteratura (anderson e jackson, 1978; frepoli et al., 1996) mostrano compressione d o w n d i p, significando che lo s l a b non sta più giocando un ruolo attivo di trazione della placca verso il basso, come potrebbe succedere invece ancora a sud, dove alcuni meccanismi mostrano distensione d o w n fig. 3 distribuzione degli effetti del terremoto del 1928 (is>v mcs; dati inediti degli scriventi). e’ importante notare la vastità del risentimento di questo evento, il cui epicentro è posto da ca v a s i n o (1935) nel tirreno meridionale, mentre secondo cpti04 ricade presso nicotera, che non ebbe, peraltro, danni di rilievo. intensity datapoint distribution for the 1928 earthquake (is>5 mcs; unpublished data). it is worth to note the vastity of the 56t h mcs degree extension. according to cavasino (1935) the epicentre falls in the southern tyrrhenian sea, whereas cpti04 locates it close to the village of nicotera (which was not affected by damage; see inset in fig. 7 for location). fig. 4 distribuzione degli effetti (is>iii mcs; dati inediti degli scriventi) dovuti al terremoto profondo (~290 km) del basso tirreno nel 1938 (mb=7.1). e’ interessante notare come lo scuotimento più elevato sia confinato in una fascia ne-sw, ben più a sudest dell’epicentro strumentale e sulla proiezione in superficie dello s l a b in subduzione verso nw (si vedano i capitoli successivi). intensity datapoint distribution for the 1938 earthquake (is>3 mcs; unpublished data). the event (mb=7.1) had a very deep focus (~290 km), within the subducting ionian slab. it is worth noting that the strongest surficial shaking is confined in a nesw belt located southwest from the instrumental hypocenter, i.e. toward the upward dip of the subducting slab. il terremoto del 1905 in calabria: revisione della distribuzione ... 212 dip, almeno al di sopra dei 150 km di profondità (ia n n a c o n e e t al., 1985; lo slab affonda sotto il proprio stesso peso?). più a nordest, infine, lo s l a b tende a “sdraiarsi” al di sotto di 500-600 km di profondità, conferendo alla litosfera ionica subdotta nel tirreno una forma complessivamente concava. in sezione, ciò è stato reso evidente nelle immagini tomografiche relative alle anomalie delle onde p; le tre sezioni di fig. 6 mostrano, chiaramente, un corpo con anomalie positive immergente verso nw (sinistra), caratterizzato da una buona continuità al di sotto del la calabria meridionale (fig. 6c), ma con una discontinuità al di sopra dei 250 km in calabria centrale (fig. 6b) e, soprattutto, in calabria settentrionale (fig. 6a). questa immagine dello slab è il retaggio della sua lunghissima migrazione verso se (300400 km) avvenuta negli ultimi 10 milioni di anni, che ha comportato, come già menzionato, la progressiva apertura del bacino tirrenico (ma l i n v e r n o e ry a n, 1986; pa t a c c a et al ., 1990; gueguen et al., 1997). diversamente dai terremoti generati nelle zone di subduzione dell’oceano pacifico ed indiano, in genere caratterizzate da ratei di convergenza altissimi se confrontati con quelli in atto nell ’arco calabro (svariati cm/anno, contro gl i 0.4-0.5 cm/anno), la sismicità associata allo slab calabro è, in genere, di bassa o moderata magnitudo (figg. 5-6). tuttavia, nel secolo scorso (1910, 1938 e 1956), nel basso tirreno sono stati registrati eventi per i quali è stata calcolata una mw≥6.2. questi terremoti, a causa della loro profondità (200-300 km), non hanno però dato che modesti risentimenti in superficie, come il citato evento del 1938, i cui effetti sembrano guidati verso la superficie dalla geometria nwimmergente dello s l a b e, forse, limitati nei quadranti nordorientali (fig. 4) dalla discontinuità laterale dello slab. 2.4 strutture sismogenetiche note dell’arco calabro le strutture responsabili fig. 5 distribuzione della sismicità degli ultimi 20 anni in calabria e zone limitrofe (da castello et al., 2006 e da dati inediti della rete enel-ismes di gioia tauro). i sei pannelli riportano gli eventi suddivisi per profondità crescente (in a, in grigio, da 0 a 33 km), a partire da m>2. e’ evidente una “deriva” verso nw degli ipocentri con la profondità, a testimonianza dell’approfondimento dello slab litosferico ionico. seismicity distribution of the past 20 years in calabria and neighbouring areas (from castello et al., 2006 and unpublished data of the enel-ismes seimic network of gioia tauro). each of the six panels shows m>2 earthquakes as a function of depth (grey circles in panel a are 0-33 km events). note the deepening of foci going toward nw which depicts the subducting ionian slab. p. galli & d. molin dei più grandi terremoti calabresi degli ultimi quattro secoli e, presumibilmente di quelli precedenti e futuri, sono quasi tutte riconducibili a faglie crostali distensive od oblique diversamente orientate ed affioranti lungo tutta la penisola, dal monte pollino a nord allo stretto di messina a sud. come anticipato, queste strutture sono state, in taluni casi, ben identificate ed investigate tramite studi paleosismologici, i quali hanno permesso di attribuire loro terremoti sconosciuti e non, occorsi nelle ultime migliaia di anni (ga l l i et al. , 2008; fig. 2). la cinematica prevalentemente normale di quasi tutte queste faglie, oltre che dai dati geologici di campagna, è altresì testimoniata dai numerosi meccanismi focali calcolati nel corso degli ult imi decenni (va n n u c c i e gasparini, 2004; neri et al., 2004, per la calabria meridionale). restano una serie di terremoti “orfani” della propria struttura sismogenetica, tra cui alcuni dei più grandi in termini energetici. oltre ai dubbi relativi agli eventi del marzo 1638 e marzo 1783, nulla di definitivo si conosce infatti sul terremoto catastrofico del 1908 (causato da una faglia posta da tutti gli autori a mare, ma con svariate ipotesi) e quello del 1905, appunto. 2.4.1 la sorgente del 1905 negli studi precedenti per il terremoto del 1905 sono noti in letteratura due diversi meccanismi focali: il primo, elaborato da ri u s c e t t i e sc h i c k (1975), presenta un piano verticale n20°, mentre il secondo, calcolato da martini e scarpa (1983) mostra una coppia di piani trascorrenti, ma ruotati rispetto al primo (i.e., nw-se e ne-sw). dal punto di vista geologico, galli e bosi (2002), seppur in assenza di indizi di attività recente, hanno ipoteticamente indicato nell’intero sistema di faglie che disseca il monte poro l’espressione superficiale complessa della sorgente del 1905. tortorici et al. (2002), lasciano invece intendere che tale struttura possa essere una faglia normale ne-sw al largo di tropea, individuata in un lavoro precedente da fa b b r i et al. ( 1 9 8 0 ) . cu c c i e te r t u l l i a n i (2006) optano, tra le faglie del monte poro, per quelle che bordano a sud l’intero promontorio (c.d. faglie di nicotera e coccorino), la cui prosecuzione a mare potrebbe essere stata la causa del maremoto. diversi autori si sono, poi, cimentati nello studio dei terrazzi marini del monte poro, con l’intenzione, non secondaria, di ricavarne informazioni sulla possibile tettonica in atto e, quindi, sulla sismogenesi. l’intero promontorio è, infatti, caratterizzato da una scalinata di superfici terrazzate, interpretabili come antiche spianate di abrasione marina, sviluppatesi durante i periodi di alto stazionamento del livello mare (i.e., durante un picco eustatico interglaciale) e quindi sollevate centinaia di metri insieme a tutto l’arco calabro nel corso dell’intero pleistocene. ma se da un lato tutti gli autori sono concordi nel riconoscere un sollevamento differenziale delle antiche linee di costa tra le varie parti del promontorio (maggiore procedendo da ne a sw), non vi è assolutamente accordo sul numero, estensione ed età delle successioni terrazzate né, conseguentemente, sui ratei e cronologia delle faglie che, secondo alcuni autori, le disarticolano. secondo miyauchi et al. (1994), le superfici marine sono dodici, databili da oltre un milione di anni a circa 80000 anni fa; le diverse quote alle quali esse si rinvengono testimonierebbero un sollevamento a duomo, cui si sovrimpone, a partire dal tardo pleistocene medio, un sollevamento regionale con tassi di 0.9-1.1 mm/anno. sul monte poro il sollevamento differenziale è poi evidenziato dalla quota del terrazzo eutirreniano (i.e., stadio 5e, ~125000 anni), che si riconosce a 50 m s.l.m. a vibo marina ed a 120 m a capo vaticano. per questi autori, infine, le faglie normali che interessano il pro213 fig. 6 sezioni tomografiche al di sotto dell’arco calabro. le tre immagini mostrano, in termini di variazioni percentuali, le anomalie di velocità delle onde p. la sezione a mostra un corpo con anomalie positive (quindi più veloce e rigido; i.e., lo slab litosferico ionico in subduzione), ma interrotto al di sopra dei 200 km. nelle sezioni b e c, invece, entrambe ubicate a sud della stretta di catanzaro, lo slab sembra sostanzialmente continuo sino a grandi profondità. sulle sezioni sono stati proiettati i terremoti rilocalizzati da chiarabba et al. (2005; ogni sezione contiene gli eventi in una fascia di 30+30 km); è possibile notare l’interruzione della sismicità profonda nella sezione a tra i 100 e 200 km di profondità, che ribatte l’assenza del corpo con anomalie positive e la sostanziale continuità nelle sezioni b e, specialmente c (da tomografie cortesemente elaborate da c. piromallo). tomographic sections beneath the calabrian arc (see index map on the left). the three panels show, in terms of percentual differences, the p-waves velocity anomalies, together with the recent seismicity (from chiarabba et al., 2005; seismicity projected from a belt of 30+30 km across each profile). section a (crossing inland the sila massif in calabria) shows positive anomalies (i.e., a cold and stiff body, as the lithospheric slab), which are interrupted over 200 km of depth. in sections b and c, both passing south to the catanzaro straits (crossing inland the serre and aspromonte ridge in calabria), the slab looks substantially continuous at depth. note the seismicity gap in section a between ~100-200 km of depth, fitting with the lack of positive anomalies (detatched slab?); conversely, seismicity is continuous in sections b-c, testifying active processes within the entire subducting slab. il terremoto del 1905 in calabria: revisione della distribuzione ... montorio vaticano non sono più attive posteriormente al pleistocene medio. cu c c i e te r t u l l i a n i (2006) riconoscono invece undici terrazzi, tra 700000 e 80000 anni fa. pur stimando un tasso di sollevamento regionale simile a miyauchi et al. (1994) durante il pleistocene superiore (~1 mm/anno), età ed attribuzione altimetrica di molti terrazzi sono in disaccordo con questi autori; inoltre, la faglia di coccorino risulterebbe attiva durante la formazione dei terrazzi, con ratei di movimento di ~0.15 mm/anno. per questo motivo, unitamente ad altre considerazioni generali sulla distribuzione delle intensità e sulla generazione dello t s u n a m i, cu c c i e te r t u l l i a n i (2006) tendono ad identificare questa faglia come quella responsabile del terremoto del 1905. secondo to r t o r i c i et al. (2003), infine, i terrazzi del promontorio vaticano sono solo sette, databili tra i 330 ka e 60 ka fa, e la loro attribuzione crono-altimetrica, stimata anche sulla base di datazioni assolute inedite, è in totale disaccordo con i precedenti autori. la loro quota attuale sarebbe la sommatoria del sollevamento regionale e, soprattutto, di quello dovuto alle faglie normali che bordano il promontorio sui lati nw, se e sw, innalzandone il blocco centrale e basculandolo a ne. il terrazzo tirreniano 5e è portato, ad esempio, sino a 300 m s.l.m. nel f o o t w a l l della faglia di coccorino (contro i 160 m massimi di mi y a u c h i et al. , 1994), alla quale si attribuiscono ratei di movimento sino a 2.5 mm/anno, mentre i ratei complessivi di sollevamento (tettonico più regionale) raggiungono talora i 4 mm/anno. data l’attività che questi autori conferiscono alle faglie del monte poro, come già anticipato, il terremoto del 1905 sarebbe legato a questo sistema di faglie ed in particolare a strutture ne-sw al largo di tropea. in conclusione, è però importante sottolineare che tutte queste ipotesi non sono suffragate né da dati geologici sull’attività tardo pleistocenica-olocenica di queste faglie, né dalla distribuzione del piano quotato in relazione alla geometria delle faglie indicate (e sicuramente relativamente a quelle di coccolino, nicotera e delle supposte strutture al largo di tropea), né, infine, dall’osservazione di alcun indizio di fagliazione di superficie in occasione del terremoto, fenomeno questo che, tenuto conto della magnitudo, avrebbe dovuto essere di grande entità (>1 m) e, quindi, di immediata visibilità nelle faglie a terra. resta l’indubbio sollevamento differenziale (tilting) dell’intero promontorio, avvenuto almeno sino a tutta la parte alta del pleistocene superiore, ma di cui poco si può dire per il pleistocene superiore-olocene. a nostro avviso, esso è comunque difficilmente imputabile al solo u p l i f t operato dalle faglie che bordano a sw il monte poro, che ne potrebbero essere, anzi, la conseguenza (i.e., tettonica gravitativa). considerando la lunghezza d’onda del fenomeno, ovvero che il tilting delle superfici si esplica lungo almeno 40 km in direzione nesw, è forse possibile pensare ad una causa più profonda, quantomeno a livello litosferico. infine, pi a t a n e s i e ti n t i (2002) forniscono una modellazione del maremoto del 1905 a partire da tre diverse ipotesi sismogenetiche tratte dalla letteratura (faglie di lamezia-catanzaro, di capo vaticano e di vibo valentia) che tuttavia non soddisfano completamente le osservazioni dell’epoca. 3. studio macrosismico 3.1. fonti informative lo studio macrosismico del terremoto è stato condotto incrementando la base informativa risultante nei lavori più recenti (bo s c h i et al., 2000; gu e r r a e savaglio, 2006). in bibliografia sono riportate solo le opere citate nel testo, mentre quelle che hanno fornito informazioni utili nelle valutazioni delle intensità – e che sono state inserite nel database delle informazioni macrosismiche – e i riferimenti a documenti d’archivio citati, sono consultabili in galli e molin (2007). 3.1.1 la relazione governativa “scomparsa” la relazione che dovrebbe rappresentare dal punto di vista macrosismico, microsismico e geologicotettonico lo studio principale sul terremoto e sul relativo periodo sismico non è stata al momento ancora reperita. e’ citata da mo n t i (1907), da ri z z o (1907) e da ta r a m e l l i (1909). e’ possibile che i lavori di tale commissione non si siano mai conclusi a causa del sopraggiungere del grande terremoto della calabria e della sicilia del 28 dicembre 1908 che, interessando fortemente le città di messina e reggio di calabria, produsse una quantità di rovine e soprattutto di vittime enormemente superiore a quelle prodotte dal terremoto del 1905 e che quindi richiese il contributo anche di tutti gli studiosi dell’epoca. 3.1.2 studi a carattere sismologico il terremoto del 1905 è presente in tutti i cataloghi sismici nazionali (p.e., ca v a s i n o, 1931; 1935; po s tp i s c h l, 1985; ca m a s s i e st u c c h i, 1997; cpti99 e cpti04) e regionali della calabria (p.e., mercalli, 1910; ca r r o z z o et al., 1975). in generale, le pubblicazioni a carattere scientifico prodotte all’epoca del terremoto non sono numerose; tra queste: • la monografia di rizzo (1907), che può essere considerata il lavoro base per lo studio macrosismico del terremoto; riporta informazioni sul risentimento di 608 località relative, soprattutto, alle allora tre province della calabria (cosenza, catanzaro e reggio di calabria) e, con meno dettaglio, alle province delle altre regioni meridionali, del molise e del lazio meridionale; • i lavori di baratta (1906, 1906a e 1907) riguardanti, il primo, osservazioni sui danni prodotti dal terremoto nei centri abitati della zona di vibo valentia, il secondo, considerazioni sulla distribuzione topografica dei danni nell’ambito dell’intera regione calabrese ed, il terzo, l’analisi dei comportamenti edilizi finalizzata alla ricostruzione delle località più fortemente danneggiate; • la relazione di me r c a l l i (1906) letta all’accademia pontaniana il 25 novembre 1906; costituisce una breve sintesi dei risultati di carattere sismologico derivanti dalle indagini effettuate da mercalli stesso nell’ambito della commissione scientifica nominata dal ministero della pubblica istruzione; • lo studio di pl a t a n i a (1907) sul maremoto e più in generale sui fenomeni di mare prodotti dal terremoto. poche anche le pubblicazioni successive, quali: • la scheda riassuntiva delle principali caratteristiche del terremoto prodotta da cavasino (1935), utilizzan214 p. galli & d. molin do il lavoro di rizzo (1907) ed i materiali fornitigli dal prof. giovanni agamennone; da notare che la scheda contiene anche un elenco dei comuni interessati (n. 518) con i relativi valori d’intensità secondo la scala me r c a l l i (1902); non vengono invece considerati i comuni in cui si ha notizia che il terremoto non è stato avvertito; • le schede sintetiche sul terremoto riportate nelle tre edizioni del catalogo dei forti terremoti in italia (bo s c h i et al. 1995, 1997 e 2000) accompagnate da un elenco località/intensità relativo a 822 centri abitati. all’atto della stesura del presente lavoro, tali schede costituiscono lo studio macrosismico più recente e completo; • il volume commemorativo del terremoto curato da guerra e savaglio (2006), costituito da numerosi articoli riguardanti vari aspetti dell’evento, da quelli tecnico-scientifici, a quelli storici, agli interventi di soccorso, ecc.; alcuni di questi articoli contengono informazioni utilizzabili nello studio macrosismico. 3.1.3 fonti “ufficiali” riguardano essenzialmente le risposte istituzionali ed amministrative dello stato. nei primi mesi dopo il terremoto il governo emise vari decreti-legge con provvedimenti a favore dei comuni della calabria danneggiati dal terremoto. successivamente, tenendo conto di tali decreti, fu emanata la “legge 25 giugno 1906, n. 255, relativa ai provvedimenti a favore della calabria”, che contiene gli elenchi dei comuni “danneggiati”, ai quali andavano applicate le disposizioni della legge stessa. da notare che il primo elenco dei comuni “danneggiati” fu pubblicato con il decreto del 22 settembre 1905 (gu, 1906) e che successivamente vi furono vari disegni di legge e altri decreti (cd, 1906a, 1906b, 1906c, 1906d, 1906e, 1907) finalizzati ad aggiornare tale elenco, generalmente aggiungendo altri comuni; gli aggiornamenti riguardarono non solo comuni della calabria, ma anche della provincia di messina (gu, 1906b). di rilievo il lavoro di pullini et al. (1906), pubblicato nel giornale del genio civile (ministero dei lavori pubblici), che riporta informazioni a carattere generale di vario genere e fornisce una carta della calabria con i comuni interessati dal terremoto suddivisi in “comuni parzialmente distrutti, o che subirono danni gravissimi”, “comuni che subirono danni gravi” e “comuni che subirono danni meno gravi”. in generale queste fonti non hanno portato contributi direttamente utilizzabili nella valutazione delle intensità; hanno tuttavia fornito elenchi di comuni danneggiati, ai quali furono applicate le varie disposizioni per i soccorsi, ed un elenco di comuni per i quali erano necessari interventi per il consolidamento di frane minaccianti centri abitati (gu, 1906a). altre fonti informative che si possono definire “ufficiali” sono costituite dalle pubblicazioni dell’ufficio centrale di statistica (istat, 1902 e 1985), che forniscono i dati sul la popolazione raccolti con i l censimento del 1901, suddivisi per comune e frazioni di comune. tali dati risultano molto utili per definire il contesto su cui agì il terremoto. 3.1.4 documentazione d’archivio i documenti inediti utilizzati provengono per lo più dall’archivio centrale dello stato di roma, di vibo valentia ed in minor misura da quelli di cosenza, catanzaro e reggio di calabria, dal l’archivio arcivescovile di santa severina, dall’archivio storico diocesano di mileto e dagli archivi comunale e vescovile di crotone. nel complesso i documenti d’archivio hanno portato un contributo di informazioni decisamente importante per qualità e quantità, superiore o almeno paragonabile a quello fornito dal complesso delle altre fonti 3 . in sintesi, la documentazione inedita utilizzata nella valutazione delle intensità può essere, in ordine all’importanza delle informazioni riportate, così suddivisa: a) relazione della commissione nominata con decreto di s.e. il presidente del consigl io ministro dell’interno in data 26 gennaio 1906 (acs 1, 1906); molto voluminosa, costituisce la più importante fonte informativa disponibile e riporta la situazione al 31 gennaio 1906 degli interventi effettuati sugli edifici danneggiati; da segnalare che tra i vari allegati di cui è composta figura: • l’elenco generale dei comuni calabresi danneggiati dal terremoto suddivisi in tre categorie: “comuni danneggiatissimi ed in parte distrutti”, “comuni molto danneggiati” e “comuni danneggiati”; • il “quadro riassuntivo dei lavori di costruzione di baracche e riparazioni di case nei comuni danneggiati e delle relative spese impegnate e da impegnare”; in questo importantissimo allegato per ogni comune viene indicato, specificando se da parte del genio civile o del genio militare, il numero di case “riparate” o “in corso” di riparazione o “da riparare”; inoltre, si forniscono i numeri di case “puntellate” o “demolite in parte”; • il “quadro riassuntivo delle spese fatte ed impegnate nei singoli comuni per riparazioni di edifici pubblici” suddivisi in: chiese, scuole, tribunali e preture, municipi, uffici poste e telegrafi, uffici di finanza, caserme dei r. carabinieri, cimiteri, ospizi di beneficenze, fontane, strade e baracche ferroviarie; b) relazione sull’erogazione delle somme raccolte dalla pubblica e privata beneficenza e di quelle iscritte nel bilancio del ministero dell’interno a sollievo dei danneggiati dal terremoto del 1905 – lavori di demolizione, puntellamento e riparazione degli edifici dannegg i a t i (acs 3, 1907); riguarda separatamente le tre province di reggio di calabria, catanzaro e cosenza e riporta le informazioni suddivise per comune e per “edifici di proprietà privata” ed “edifici pubblici”; come si può notare dal titolo, fornisce informazioni simili a quelle del documento precedente, ma aggiornate al 30 giugno 1907; c) “prime notizie” (acs 4-43, 1905), in genere composte da telegrammi delle prefetture diretti al ministero dell’interno; in generale contengono informazioni sugli effetti del terremoto nei centri abitati (danni, vittime, feriti), domande di soccorso urgente, provvedimenti immediati presi dai prefetti, ecc.; in generale riportano informazioni molto utili, anche se spesso parziali; 215 3da ricordare che per il terremoto del 1905 non sono disponibili le “cartoline sismiche” pervenute all’ufficio centrale di meteorologia e geodinamica di roma (ucmg), solitamente conservate presso l’archivio dell’istituto nazionale di geofisica e vulcanologia. il terremoto del 1905 in calabria: revisione della distribuzione ... d) documenti inediti dell’archivio centrale dello stato (acs 74-84, 1905-1909) generalmente riguardanti richieste di sussidi per riparazione di chiese ed altri edifici di culto; e) documenti inediti dell’archivio centrale dello stato (acs 44-73, 1905-1911), dell’archivio di stato di catanzaro (asca 1-4, 1905-1909), dell’archivio di stato di cosenza (asco 1-2, 1905-1906), dell’archivio di stato di reggio di calabria (asrc 1, 1906) e dell’archivio storico diocesano di mileto (asdm 1, 1905), ripresi da bo s c h i et al. (1997); si tratta di documenti riguardanti richieste da parte dei comuni per essere inclusi nell’elenco dei paesi danneggiati, o descrizioni di effetti relativi a singoli comuni ed anche a singoli edifici, quasi sempre a chiese; f) documenti inediti dell’archivio di stato di vibo valentia (asvv 1-27, 1905-1908); si tratta dei documenti resi disponibili dall’archivio stesso in occasione della mostra organizzata in occasione del centenario del terremoto; sono stati utilizzati ed inclusi in bibliografia solo quelli utili per le valutazioni d’intensità; si tratta di scritti di vario genere (lettere, suppliche, verbali comunali, delibere, ecc.), quasi sempre riferiti a singoli comuni o località, che informano sugli effetti prodotti dal terremoto; g) documenti inediti dell’archivio arcivescovile di santa severina (aass 1-25, 1905-1911); riguardano interventi alle chiese della diocesi, quali perizie di danni, lavori da effettuare per le riparazioni, distribuzione di sussidi, verbali di riunioni, ecc.; h) documenti inediti dell’archivio comunale di crotone (ackr 1-5, 1905-1906) e dall’archivio vescovile di crotone (avkr 1-3, 1906) riguardanti interventi per riparare danni prodotti dal terremoto ad edifici di crotone; tale documentazione è raccolta nella relazione di galli et al. (2005); i) relazione della commissione d’inchiesta pel terremoto delle calabrie (acs 2, 1907) al presidente del consiglio e ministro dell’interno; contiene informazioni di vario genere riguardanti la provenienza dei fondi, la distribuzione dei sussidi, i compiti assegnati al genio civile e militare, l’azione dei comitati di soccorso, accuse e lagnanze contro l’opera governativa, ecc.; riporta inoltre quadri riassuntivi delle spese e degli interventi e saltuariamente descrizioni di danneggiamenti in singoli comuni. da quanto sopra appare evidente l’importanza delle relazioni di cui ai punti a) e b), relazioni che rappresentano in assoluto le due più importanti fonti sul terremoto, sia per la quantità che per la qualità delle informazioni riportate. 3.1.5 giornali le informazioni macrosismiche derivanti dalle notizie giornalistiche sono abbondanti solo nella settimana successiva all’evento, per lasciar poi posto ad altre tipologie, come quelle sugli interventi di soccorso e sulle raccolte di fondi, con lunghi elenchi di enti e di persone che hanno contribuito. considerando che molto spesso le notizie sui giornali sono ripetitive, sono state consultate in modo sistematico le due o tre settimane dopo il terremoto del giornale di sicilia di palermo, il mattino di napoli, la nazione di firenze, corriere della sera di milano, il giornale d’italia e la tribuna di roma. per gli stessi motivi, altre testate (la discussione di napoli, l’ora di palermo, il gazzettino di venezia, l’avanti, ecc.) sono invece state consultate solo parzialmente. riguardo ai giornali locali, sono stati compulsati alcuni numeri de la rivista vibonese, della cronaca di calabria e del corriere calabrese. molto importante, inoltre, il numero speciale del giornale “monteleone”, pubblicato l’8 settembre 2005 per commemorare il terremoto; vi si descrivono gli effetti nei centri abitati del vibonese, le vittime, i primi soccorsi, gli enti e le persone che più si adoperarono per le riparazioni e la ricostruzione. di interesse per le numerose immagini sui danni prodotti dal terremoto sono anche alcune corrispondenze dei settimanali la domenica del corriere e l’illustrazione italiana, entrambi stampati a milano. nel complesso, le notizie derivanti dai giornali, essendo generalmente originali, sono risultate molto utili, sia per la quantità di informazioni, sia per la possibilità di effettuare confronti con altri tipi di fonti. tuttavia, bisogna precisare che a volte le notizie pubblicate nei giorni immediatamente successivi all’evento non sono risultate affidabili quanto le corrispondenze degli inviati speciali che visitarono i luoghi maggiormente colpiti dal terremoto nei giorni immediatamente successivi all’8 settembre. le testimonianze di alcuni di questi inviati sono state successivamente raccolte in volumi, come ad esempio quelle importantissime di malagodi (1905), jaricci (1905) e cotroneo (1906), dalle quali si evince che gli stessi viaggiavano a volte in treno, più frequentemente in automobile o in carrozza, spesso aggregati alle colonne dei soccorsi o alle visite di importanti personaggi pubblici (il re, vari ministri e parlamentari, vescovi, ecc.). 3.1.6 storie locali ed altre opere si tratta di cronache locali, raccolte di immagini, commemorazioni del terremoto, ecc., per le quali non è stata svolta alcuna ricerca sistematica e quindi risultano nel complesso poco numerose. d’altra parte, le informazioni che si ricavano sono spesso limitate e non originali, in quanto generalmente riprese da altre opere. da ricordare, per la quantità di documenti fotografici, pu g l i e s e (1996) ed immagini dal terremoto 1 9 0 5 2 0 0 5 (2005), quindi, per descrizioni degli effetti in singole località, anelli (2005) per castrolibero, de medici (1989) per martirano, kostner (2002) per aiello, re (2006) per san martino di finita, tripodi (1945) per sant’eufemia in aspromonte, ma y d a (1918) e co v e l l i (1918) per crotone, anche se le descrizioni sono, in genere, minime. da ricordare, infine, le varie relazioni sull’opera dei comitati di soccorso (p.e., bi a n c o n c i n i, 1906; cere, 1906; nava, 1907), che si erano costituiti in alcune grandi città italiane. un resoconto complessivo sull’opera dei comitati di soccorso è riportata in acs 2 (1907). in queste opere, oltre alle descrizioni sugli interventi effettuati e ai rendiconti delle spese, occasionalmente si riportano informazioni sui danni prodottisi relativamente a località o a singole costruzioni, informazioni risultate utili nel ricostruire il quadro degli effetti in singoli centri abitati. 3.2 quadro generale degli effetti prodotti dal terremoto il terremoto fu risentito con effetti più o meno gravi in un’area molto vasta, che comprende la sicilia nord-orientale, la calabria, la basilicata, la campania, la 216 p. galli & d. molin puglia, il molise occidentale ed in piccola parte il lazio meridionale (fig. 7) 4 . la scossa principale, verificatasi l’8 settembre alle ore 1.43.11 (gmt), fu seguita da numerosissime repliche, alcune delle quali incrementarono i danni, anche se generalmente in modo non molto sensibile. secondo ca v a s i n o (1935): “… a l l ’ u f f i c i o centrale di meteorologia e geodinamica si ebbe notizia di 219 repliche fino a tutto dicembre 1905, di altre 95 verificatesi durante l’anno 1906, ed 82 nel 1907. di tali repliche alcune furono comuni a tutta l’area disastrosa della grande scossa; altre, invece, furono avvertite solamente nel monteleonese [area di vibo valentia], ovvero solamente nel cosentino. …”. in mo n t i (1906) e martinelli (1909; 1910) sono riportati solo i tempi in cui sono avvenute queste repliche, ma non le informazioni sul risentimento nei centri abitati. riguardo al numero delle vittime, in galli e molin (2007, appendice a) sono riportati i dati raccolti suddivisi per comune e, quando possibile, per frazione di comune ed in tab. 1 i dati complessivi e, quando possibile, per provincia. da precisare che non sono considerate le informazioni fornite dai giornali, in quanto spesso appaiono esagerate, anche quando si rimanda a fonti governative o ufficiali. si può facilmente notare che non sono disponibili dati precisi ed inoltre che in quasi nessuna opera vengono indicate chiaramente le fonti informative. fa eccezione solo il lavoro di savaglio (2006), i cui dati derivano da una recente ed approfondita indagine nei registri dello stato civile e negli atti parrocchiali delle località più fortemente interessate dal terremoto. i dati forniti da acs 3 (1907), come probabilmente quelli di varie altre opere, dovrebbero derivare da fonti governative o enti locali, quali prefetture, carabinieri, comuni, province, ecc. secondo savaglio (2006), le percentuali più elevate di vittime si verificarono nei comuni di piscopio (25.7%; attualmente frazione di vibo valentia; fig. 1), san gregorio d’ippona (10.7%) e stefanaconi (9.50%), anche se, riferendosi al censimento del 1901 (istat, 1902), le percentuali che si ottengono sono decisamente meno elevate (rispettivamente, 4.6%, 4.8% e 3.6% per stefanaconi). le donne rappresentarono il 65% delle vittime, in considerazione del fatto che molti uomini erano emigrati o dormivano all’aperto in campagna per sorvegliare i raccolti o erano imbarcati su pescherecci. nel complesso, il numero delle vittime appare limitato rapportato alla grande diffusione di crolli e distruzioni; ciò potrebbe essere legato all’allarme prodotto dai f o r e s h o c k s (p.e., il 6 settembre a briatico le persone ne furono destate; ba r a t t a, 1906), avvenuti sino all’ora antecedente al m a i n s h o c k (ba r a t t a, 1906; mercalli, 1906; cavasino, 1935). l’entità e la diffusione dei danni agli edifici furono particolarmente forti, con diffusi crolli e distruzioni, nell’area di monte poro e lungo il litorale tirrenico del golfo di sant’eufemia, mentre i danni moderati e leggeri interessarono quasi tutta la calabria, il settore nord-orientale della provincia di messina, le isole eolie e varie località situate per lo più nei settori meridionali delle province di potenza ed in minor misura di salerno. la principale caratteristica del danneggiamento è rappresentata da una distribuzione molto irregolare, con centri abitati pressoché distrutti situati vicino ad altri con danni moderati o leggeri (me r c a l l i, 1906; ba r a t t a, 1906a; rizzo, 1907; acs 2, 1907 5 ). un quadro complessivo del danneggiamento e delle vittime è riassunto nelle tabelle 2 (acs 3, 1907) e 3 (acs 1, 1906) che rispecchiano abbastanza bene i dati raccolti nell’ambito del presente lavoro. gli interventi descritti riguardano la riparazione, il puntellamento e la demolizione, parziale o totale, di case generalmente adibite ad uso abitazione. da ricordare, inoltre, che in nessuna di queste importanti relazioni, né in pullini et al. (1906), in cui si riportano dati simili a quelli di tab. 2, e neppure in altre opere vengono forniti in modo sistematico dati sugli edifici crollati. 217 cotroneo mercalli lucifero pullini acs 3 rizzo baratta taramelli mercalli cavas. savaglio provincia 1906 1906 1906 1906 1907 1907 1907 1909 1910 1935 2006 cosenza 46 30 47 47 catanzaro 491 480 480 485 reggio di c. 1 1 2 1 totale 538 557 511 600 529 533 557 557 557 557 509 tab. 1 numero delle vittime causate dal terremoto dell’8 settembre 1905 secondo i dati disponibili. 5 “… i danni arrecati dal terremoto alle case furono di importanza diversa, non solo nelle tre provincie calabresi, non solo nei vari paesi di ogni provincia, ma persino nelle contrade di uno stesso paese. così, ad esempio, in provincia di catanzaro si ebbero comuni o frazioni quasi completamente distrutti, … di fronte a comuni rimasti quasi illesi …; e così un quartiere di monteleone rimase seriamente danneggiato, mentre le altre parti della città poco o nulla ebbero a risentire delle scosse. la maggior intensità del disastro si manifestò nella penisola di capo vaticano, nel circondario di monteleone, ma anche in altre regioni si fece sentire in modo assai energico, come nella contrada tra aiello e martirano al confine delle provincie di cosenza e catanzaro, fra palmi e melicuccà, in provincia di reggio, e presso maida ed olivadi, in provincia di catanzaro. …” 4si veda già in rizzo (1907), la carta delle “linee isosismiche” secondo la scala mercalli (1902) a 10 gradi, allora in uso. dalla stessa carta si può anche osservare che le intensità più elevate (x grado) hanno interessato località situate a nord e a sud del golfo di sant’eufemia e le intensità un po’ meno elevate (ix grado) varie altre località dell’area a sud di cosenza, della stretta di catanzaro e dell’area del monte poro. notevoli estensioni mostrano poi le aree di viii, vii e vi grado, tanto da interessare quasi tutta la calabria e la parte nord-orientale del messinese). il terremoto del 1905 in calabria: revisione della distribuzione ... nelle tabelle 2-3 appaiono chiaramente i maggiori danni sofferti dalla provincia di catanzaro rispetto a quella di cosenza e in molto maggior misura rispetto a quelli della provincia di reggio di calabria. molto indicativo a questo proposito risulta il numero delle vittime (tab. 2), dieci volte superiore nel la provincia di catanzaro rispetto a quello della provincia di cosenza, mentre risulta estremamente limitato in provincia di reggio di calabria. 3.3 stima delle intensità allo scopo di meglio utilizzare le informazioni macrosismiche contenute nelle numerose opere consultate, presso gli scriventi è stato costruito un apposito database, nel quale per ogni comune vengono riportati: i quadri sintetici degli effetti sull’uomo, sui fabbricati, sul terreno e sulle acque, compilati in base alle informazioni disponibili ed utilizzati nelle stime delle intensità; le stime di intensità effettuate in questo lavoro ed in quelli precedenti; dati di carattere amministrativo attuali e all’epoca del terremoto; in particolare, vi figura per ogni centro abitato (capoluogo e frazioni di comune) il numero di abitanti, secondo il censimento della popolazione del 1911 (istat, 1902 e 1985); le informazioni macrosismiche disponibili stralciate integralmente dalle opere originali; le descrizioni disponibili sul maremoto, anch’esse stralciate integralmente dalle opere originali. dal database sono stati estratti i dati riportati nelle appendici a, b e c (consultabili in galli e molin, 2007) 6 . i dati sul maremoto, nel complesso non abbondanti, sono invece riportati nel relativo paragrafo. la stima delle intensità (is) nei centri abitati interessati dal terremoto è stata effettuata utilizzando la scala macrosismica mercalli-cancani-sieberg (mcs, 1 9 3 0 ) 7 . è da ricordare, tuttavia, che all’epoca praticamente tutte le costruzioni erano in muratura e che osservazioni effettuate da vari autori (me r c a l l i, 1906; baratta, 1906, 1906b e 1907; rizzo, 1907; pullini et al., 1906; vulcano e mazza, 2006) indicano per i paesi più danneggiati, un diffuso cattivo stato di conservazione degli edifici, un frequente utilizzo di materiali molto scadenti ed una non buona esecuzione d’opera. queste considerazioni e l’osservazione di fotografie di case distrutte o danneggiate (pu g l i e s e, 1996; immagini dal terremoto 1905-2005, 2005), fanno ritenere che in grande maggioranza le costruzioni debbano essere state caratterizzate da vulnerabilità molto elevata. per quanto riguarda l’applicazione della scala mcs (1930) è da precisare che si è tenuto conto dei cinque livelli di danno e delle percentuali di edifici danneggiati, che si deducono dalle specifiche dei gradi riportate nelle tabelle della scala stessa. si precisa inoltre che, come da tempo è pratica comune in italia, si è assegnato il vi grado in presenza di danni di livello 1 diffusi a circa metà degli edifici ed il v-vi grado nei casi di danni di livello 1 poco diffusi. le difficoltà incontrate nelle valutazioni d’intensità sono dovute alla presenza di informazioni incomplete, 218 tab. 2 quadro riassuntivo del danneggiamento secondo acs 3 (1907); situazione al 30 giugno 1907. il totale in lire d’epoca dei danni potrebbe corrispondere a circa 200 milioni di euro. popolazione danni ammontare provincia di comuni abitati dei alle persone approssimativo danneggiati danneggiati comuni dei danni danneggiati morti feriti alle proprietà cosenza 107 287 374.374 47 222 20.500.000 catanzaro 135 279 453.778 480 1598 21.000.000 reggio di calabria 86 187 363.617 2 57 7.000.000 totali 328 753 1.191.769 529 1877 48.500.000 tab. 3 quadro riassuntivo degli interventi post-terremoto effettuati sulle abitazioni dal genio civile e dal genio militare nelle province di catanzaro, cosenza e reggio di calabria, secondo acs 1 (1906); situazione al 31 gennaio 1906. provincia di numero delle case riparate o in corso da riparare demolite puntellate cosenza 4.706 9.485 2.293 1.782 catanzaro 9.528 7.736 3.360 4.301 reggio di calabria 3.560 4.093 1.042 1.267 totali 17.794 21.314 6.695 7.350 6tali dati riguardano la mortalità osservata per comune e, se possibile, per frazione di comune (appendice a), gli effetti cosismici sul terreno e nelle acque superficiali e sotterranee (b), l’elenco dei comuni e frazioni di comune interessati dal terremoto con relativo valore di intensità (c; “piano quotato”). 7l’impiego della recente scala macrosismica europea (ems, 1998) non risulta praticabile, in quanto non sono quasi mai disponibili informazioni adeguate sulle tipologie edilizie presenti nelle varie località, sullo stato di conservazione degli edifici e quindi sulla vulnerabilità degli edifici. p. galli & d. molin sintetiche o, talvolta, contrastanti. in particolare, per questo terremoto la maggior parte delle informazioni dettagliate sui danni alle abitazioni e agli edifici pubblici derivano dalle relazioni in acs 1 (1906) e acs 3 (1907). in entrambe si specificano i numeri di case “riparate” o “in corso” di riparazione o “da riparare”; di case “puntellate” e di case “demolite” in tutto o in parte, ossia i numeri di case sulle quali si era intervenuti o si doveva intervenire con riparazioni e restauri; non si specificano, come già osservato, i numeri di case “crollate” per le quali non erano previsti interventi, se non lo sgombero delle macerie che intralciavano i lavori, o la viabilità. con questo tipo di informazioni a disposizione si è così operato: • le case “riparate” o “in corso” di riparazione o “da riparare” sono state considerate affette da danni di livello 2 (danni moderati); • le case “puntellate” sono state considerate come affette da danni di livello 3 (danni gravi, ma gli edifici risultano recuperabili); • la case “demolite” in tutto o in parte sono state considerate come affette da danni di livello 4 (danni così gravi che gli edifici non sono più recuperabili); • le quantità di crolli (danni di livello 5), non segnalate in acs 1 (1906) e acs 3 (1907), sono state riprese o stimate considerando le informazioni riportate in altre fonti. nei casi in cui si dispone solo di valori d’intensità secondo la scala me r c a l l i (1902) non accompagnati dalla relativa descrizione degli effetti, casi tutti provenienti dal lavoro di rizzo (1907), si è così operato: • i valori caratterizzati da is≤v grado mercalli sono stati considerati pari ad analoghi valori secondo la scala mcs; • i valori caratterizzati da is = vi o al vii grado mercalli sono stati considerati pari rispettivamente al v-vi e vi-vii grado mcs, in quanto si è osservato che rizzo (1907) assegna il vi grado mercalli anche in assenza di danni ed il vii mercalli con danni moderati poco diffusi. da notare che generalmente i valori caratterizzati da is>vii mcs sono sempre accompagnati da descrizioni degli effetti, anche se a volte molto brevi. inoltre, ai pochi comuni per i quali è disponibile, come unica informazione, la richiesta di inclusione nell’elenco dei comuni danneggiati per godere dei benefici della legge 25 giugno 1906, n. 255 (cd, 1906a, 1906b, 1907), è stato assegnato un incerto v-vi grado mcs per analogia con altri comuni per i quali, oltre alla richiesta di inclusione, sono disponibili anche descrizioni degli effetti. il quadro dei dati d’intensità disponibili è riportato nell’appendice c di galli e molin (2007). nel complesso vi figurano 895 centri abitati, appartenenti a 840 comuni. da tab. 4, nella quale è sintetizzata la composizione del “piano quotato” secondo classi d’intensità, si può osservare la presenza di numeri relativamente elevati di centri abitati per le classi d’intensità comprese tra il v e l’viii grado; ciò appare collegabile al fatto che per le località della calabria, dove il terremoto ha prodotto quasi sempre danni agli edifici più o meno gravi, si posseggono informazioni per quasi tutti i comuni e parte delle frazioni, mentre per le altre regioni, dove gli effetti sono stati meno importanti, le informazioni sono molto più parziali e poco diffuse. il numero delle località è molto aumentato rispetto alle 608 segnalate da rizzo (1907), alle 518 di cavasino (1935; che considera solo i capoluoghi comunali e non segnala i risentimenti negativi nf), alle 822 di boschi et al. (2000). il confronto tra le stime delle intensità risulta possibile solo con bo s c h i e t a l. (2000), in quanto espressi secondo la stessa scala. su 819 casi in cui sono disponibili dati in entrambi i dataset, in 389 casi (47%) sono stati assegnati gli stessi valori d’intensità (265 casi per is � v grado, 105 tra il v-vi e l’viii grado e 19 tra l’viii-ix ed il x-xi grado); in 352 casi (43%), sono stati assegnati valori più bassi, con differenze fino a due gradi; in 55 casi (7%) sono stati assegnati valori più elevati, con differenze fino a due gradi e mezzo; in 22 casi (3%) non è stato assegnato alcun valore, ma solo le indicazioni di danni singoli o non specificati (d) e di risentimento generico (f); tali indicazioni sono presenti in un solo caso in boschi et al. (2000). nei 429 casi in cui le stime d’intensità sono variate in più o in meno, la maggior parte (88%) riguardano is comprese tra il v-vi e l’viii grado, mentre solo in 24 casi is comprese tra l’viii-ix ed il x-xi grado. 3.4 campo macrosismico in fig. 7 è rappresentato il campo macrosismico derivante dal piano quotato riportato integralmente in galli e molin (2007, appendice c), da cui si evince che il terremoto ha prodotto danni gravi o gravissimi (is compresa tra vii-viii e x-xi grado mcs) in numerosi centri abitati dell’intera fascia tirrenica calabra; molti altri punti, generalmente di vii-viii ed viii grado, sono presenti anche all’esterno di questa fascia, lungo i versanti della valle del crati e nella piana di gioia tauro, ma isolati tra più numerosi punti d’intensità inferiore. all’interno della fascia sono invece presenti anche pochi punti di intensità più modeste, comprese tra vivii e vii mcs. nel resto della calabria, nella parte nordorientale della provincia di messina, nelle isole eolie e, in casi sporadici, nelle parti meridionali delle province di potenza e salerno, il terremoto ha causato danni moderati o leggeri (intensità comprese tra v-vi e vii mcs). in puglia, campania e basilicata fu per lo più solo avvertito da parte delle persone, così come in buona parte della sicilia centro-orientale e del molise occidentale ed in qualche località del lazio meridionale. nonostante la citata irregolarità della distribuzione delle intensità, l’andamento generale del campo macrosismico (aree a mare a parte) è dunque caratterizzato da una propagazione nne-ssw. l’area mesosismica 219 tab. 4distribuzione del numero di centri abitati per classi d’intensità (is) secondo i dati raccolti (nf e f, non avvertito e avvertito). classi d’intensità (mcsx10) nf f 20 25 30 35 40 45 50 d 55 60 65 70 75 80 85 90 95 100 105 num. centri abitati 88 5 20 2 50 2 32 2 104 34 80 98 82 131 56 60 14 17 7 8 2 il terremoto del 1905 in calabria: revisione della distribuzione ... (is ≥ viii mcs) si estende per 60-70 km e contiene sei dei dieci punti con is ≥ x mcs e vari altri attorno al ix grado, concentrati nell’area compresa tra parghelia e vibo valentia (comuni di cessaniti e briatico; vedi riquadro in fig. 7). anche l’area contenente la grandissima parte dei punti con is ≥ vii mcs si sviluppa maggiormente in direzione nne-ssw, lungo il tratto compreso tra lo stretto di messina ed il confine tirrenico settentrionale della calabria, per una lunghezza di circa 180 km (fig. 8); la direzione ortogonale, comprendendo grosso modo la stretta di catanzaro quasi per intero ad est e l’isola di stromboli ad ovest, si sviluppa per 110 220 fig. 7 dtm dell’area di risentimento del terremoto del 1905 e relativa distribuzione delle intensità. nel riquadro, particolare dell’area del monte poro (dalle basi al 1:25.000 igmi). il piano quotato completo del terremoto è pubblicato in galli e molin (2007). dtm of the region affected by the 1905 earthquake, and mcs intensity datapoint distribution according to the data reported in galli and molin (2007). the inset shows the detail of the most damaged area (mt. poro; from 1:25.000 scale maps). p. galli & d. molin km circa. all’interno di quest’area – ma esternamente a quella mesosismica s.s. sono presenti due centri abitati (martirano e limpidi ) con is = x mcs, uno (melicuccà fr. di dinami) con is = ix-x grado e due altri (castrolibero e olivadi) con is = ix mcs: le elevate intensità delle prime tre località sono dovute alla presenza di fenomeni franosi all’interno dei centri abitati, mentre non si hanno informazioni per le ultime due. una vasta area contenente quasi tutti i punti con is ≥ vi mcs (figg. 7-8) sembra svilupparsi maggiormente in direzione nne-ssw, tra il litorale ionico siciliano di forza d’agrò e la parte meridionale della provincia di potenza (maratea, san severino lucano), per una lunghezza di circa 280 km. la distanza lungo la direzione ortogonale non risulta invece stimabile, in quanto gli estremi ricadono nel mar ionio ad est e nel tirreno ad ovest; al suo interno si notano relativamente pochi punti con is > vi mcs, tra i quali uno solo (simbario) di viii grado e meno di una decina ≥ vii grado. le dieci località con intensità più elevate ricadono in aree dove a brevi distanze sono presenti altre località interessate da effetti molto meno gravi, corrispondenti al vii o all’viii grado mcs. ne deriva che per questi centri abitati è ipotizzabile l’intervento di fenomeni franosi e/o di effetti amplificazione locale (vedi più avanti punto 3.7), oppure la presenza di un patrimonio edilizio estremamente vulnerabile e/o sensibile alla frequenza dominante del terremoto. 3.5 il maremoto come più volte detto, il terremoto del 1905 innescò anche un maremoto che colpì prevalentemente le coste tirreniche, come dettagliatamente descritto da pl a t a n i a (1907), in quello che forse può essere considerato uno dei primi lavori scientifici descrittivi di un maremoto. le località per le quali furono riportate osservazioni sono, tuttavia, molto poche a causa del fatto che il fenomeno avvenne in piena notte e fu di entità relativamente modesta. esso fu segnalato da testimoni solo a briatico, milazzo, pizzo, scalea, tropea, bivona, porto santa venere (vibo marina) e a marina di catanzaro. fu poi registrato analiticamente dai mareografi di messina, ischia, napoli (arsenale e mandracchio) e civitavecchia, che segnalarono anche l’ora di arrivo della prima onda (p.e., alle 3.20 a ischia e alle 3.45 a civitavecchia) e l’ampiezza massima (tra 7 e 18 cm), come dettagliatamente discusso in platania (1907). dall’insieme delle notizie reperite il fenomeno fu complessivamente poco invasivo lungo le coste, provocando minimi danni a piccole imbarcazioni e capanne, nessuna vittima e nessun ferito. molte barche e navi in 221 fig. 8 immagine digitale del terreno dell’area colpita dai maggiori effetti nel corso del terremoto del 1905 e relativa distribuzione delle intensità. la linea a tratteggio delimita l’area all’interno della quale si sarebbero verificati effetti riconducibili al vii grado mcs e superiori; tale area è estesa per circa 180 km in senso nne-ssw (n.b., ad ovest la distribuzione è ancorata ai soli punti delle isole eolie ed è quindi approssimativa). in posizione baricentrica ad essa, ed al centro della sorgente ipotizzata entro e parallelamente allo slab (box a tratteggio), è posizionato il possibile epicentro del terremoto. l’ellisse a tratteggio è l’area all’interno della quale michelini et al. (2006) hanno calcolato l’epicentro strumentale (la stella rappresenta il massimo della probabilità); nella nostra ipotesi potrebbe corrispondere alla zona di enucleazione della rottura, che si sarebbe propagata poi verso ne. il simbolo “+” lungo le coste indica le località ove fu osservata l’onda di maremoto con primo impulso positivo (“+“ dove fu preceduta dal ritiro delle acque, i.e., a scalea). dtm of the mesoseismic area of the 1905 event, and mcs intensity datapoint distribution (see analytic data in galli and molin, 2007). the dashed isoseismal line labelled vii mcs envelops the area affected by i≥7 mcs, being nne-ssw extended for ~180 km (to the west the intensity distribution is anchored only to the eolie islands only). the dashed box in the middle of the 7th mcs area suggests the possible seismogenic source location for the 1905 earthquake. the dashed ellipse represents the possible area of the 1905 epicenter according to michelini et al. (2006). the black star is their maximum probability point, which could be the enucleation point for the large rupture depicted by our the dashed box. symbol + along the calabrian coast indicates positive first-impulse tsunamis wave (+ indicates the scalea shore, where the sea firstly retreated). il terremoto del 1905 in calabria: revisione della distribuzione ... navigazione od all’ancora nei porti del tirreno meridionale ebbero la percezione di un urto sullo scafo (dovuto all’arrivo delle onde di compressione) e di movimenti insoliti del mare, mentre fu riportata la notizia che in diverse località molti pesci furono spiaggiati. nell’ora del terremoto, a briatico alcuni pescatori prossimi a riva furono portati sulla loro barchetta 8 metri entro la spiaggia (platania, 1907). a milazzo, invece, la banchina del porto fu invasa dal mare (pl a t a n i a, 1907). tra pizzo e tropea, in concomitanza dell’evento sismico, sulle spiaggie si verificò una “crescente marea di diversi metri” (platania, 1907), a luoghi profonda sino a 5 metri (il giornale d’italia, 11/09/1905). sempre a tropea, alcune baracche situate sulla spiaggia furono portate in mare da una marea alta almeno due metri e poi allontanate da riva di 3-4 miglia (platania, 1907). l’effetto apparentemente più invasivo, seppur privo di danni, avvenne lungo la spiaggia di scalea, dove si narra che il mare ingredì “t r a n q u i l l i s s i m o” per oltre 30 metri. secondo la delegazione di porto di scalea, all’ora del terremoto “si avvertì un improvviso abbassamento del livello del mare, che pochi momenti dopo si rialzò, spingendosi agitato sul lido, dove pose pericolo ad alcune barche pescherecce tirate a secco” (il giornale d’italia, 10/09/1905; platania, 1907). altre fonti riportano un’ingressione “f u r i o s a” del mare per oltre 20 metri, “trasportando e capovolgendo alcune b a r c h e” (giornale di sicilia, 10/09/1905) oppure “p o rtando seco in alto un battello che era tirato sul lido, e mettendo in pericolo molte altre barche più grandi poste anche esse in secco” (il mattino, 10/09/1905). l’altezza dell’onda di run-up, localmente, sembra aver raggiunto i 6 metri sopra la scogliera (ri z z o, 1907), imputabili, probabilmente, all’altezza raggiunta dall’onda di frangente. infine, nella zona di vibo marina (fig. 9), oltre alle segnalazioni di pesci e tonni gettati sulla spiaggia a bivona (la tribuna, 19/09/1905), il mare avanzò sul lido di porto s. venere di circa 6 metri, spiaggiando varie barche (ba r a t t a, 1906). secondo la relazione di giuseppe marcello (direttore del l’osservatorio meteorologico di pizzo; in rizzo, 1907), “i pescatori … cessata la scossa, furono atterriti da un altro fenomeno: le acque del mare, che prima era calmissimo, si addentrarono sulla spiaggia di bivona, per una lunghezza di trenta e più metri, spingendo fin là una barca peschereccia tirata a secco a pochi passi dal lido, quindi le onde si ritrassero.”. sullo ionio, l’unico fenomeno è segnalato alla marina di catanzaro, dove la spiaggia fu invasa dalle acque che strapparono una boa d’ancoraggio (ri z z o, 1907; il mattino, 10/09/1907). oltre a ciò ed alle oscillazioni del livello del mare che interessarono ciclicamente molte località del tirreno per tutta la giornata, platania (1907) riporta dettagliatamente la rottura del cavo telegrafico milazzolipari, avvenuta contemporaneamente al terremoto circa 12 km ad e dell’estremità s di vulcano. il quadro che si ottiene, come già anticipato, è quello di un maremoto nemmeno lontanamente confrontabile con quello catastrofico del 1908. gli effetti più rilevanti furono osservati a scalea, ma forse solo perché da poco era terminata una festa che aveva tenuti svegl i gl i abitanti ( i l giornale di sici lia , 10/09/1905). in ogni caso, la percezione dell’avvenimento da parte dei testimoni indica un innalzamento rapido del livello del mare di ~1-2 metri (preceduto solo a scalea da un breve ritiro), con ingressione nella spiaggia di 5-30 m, a seconda della configurazione altimetrica della stessa. tra le località del vibonese 222 fig. 9 veduta di porto santa venere con il vapore dei soccorsi di genova ormeggiato. in primo piano, alle spalle della duna costiera, è visibile un’area di ristagno formatasi, probabilmente, in seguito all’ingressione dell’onda di maremoto. view of porto santa venere, with the genoa rescue ship moored. in foreground, behing the coastal dune with the provisional tents, note the stagnant water remained after the tsunamis-wave ingression. p. galli & d. molin (tropea, briatico, bivona e pizzo) e scalea, lungo costa non sono note altre segnalazioni, così come tra le stesse e milazzo. negative, inoltre, sono le segnalazioni dalle eolie (notizie dell’ufficio di porto di lipari, in platania, 1907). sullo ionio, poi, si è a conoscenza della sola notizia sul lido di catanzaro marina. ipotizzando per quest’ultimo caso un’origine locale, dovuta forse ad una frana sottomarina innescata nel golfo di squillace dallo scuotimento (analogamente a quanto ipotizzabile per la rottura del cavo telegrafico sottomarino a vulcano) e considerando gli effetti sulle coste si ha l’impressione che la deformazione del fondo marino non fu di grande entità, specialmente confrontandola con quella connessa alle grandi dimensioni che dovette avere la sorgente sismogenetica. questo fatto, come discusso in seguito, potrebbe rappresentare una delle numerose evidenze indirette della profondità della sorgente stessa. 3.6 effetti cosismici sul terreno e nelle acque sotterranee e superficiali gli effetti cosismici (vedi appendice b in ga l l i e molin, 2007), rappresentati soprattutto da fenomeni franosi, rotture del terreno, variazioni al regime idrico delle acque sotterranee, intorbidamenti e liquefazioni di depositi granulari, furono diffusissimi: nel complesso si ha notizia che interessarono ben 110 comuni, ovvero il 25% di tutti i comuni che subirono danni agli edifici, anche se molto lievi (is ≥ v-vi grado mcs). con l’aumentare della gravità dei danni aumenta anche la percentuale dei comuni interessati da effetti cosismici; ad esempio, per i comuni caratterizzati almeno da danni moderati (is ≥ vii mcs) la percentuale sale al 37%, per i comuni interessati da distruzioni (is ≥ viii-ix mcs) al 58% e per i comuni con effetti disastrosi (is ≥ x mcs) all’86%. gli effetti cosismici, particolarmente se rappresentati da fenomeni franosi, nei numerosi casi in cui hanno interessato direttamente i centri abitati, hanno ovviamente aumentato il danneggiamento e quindi influito sulle valutazioni delle intensità. contestualmente al terremoto, furono segnalati molti fenomeni verosimilmente riconducibili agli effetti che le sovrappressioni interstiziali generate dallo scuotimento ciclico indussero nei terreni granulari saturi confinati, ovvero liquefazioni. i casi in cui sono state descritte aperture nel terreno, con fuoriuscita d’acqua – spesso zampillante – associata a sabbia, ghiaia e limo, sono riferibili a 21 località (appendice b in ga l l i e mo l i n, 2007; fig. 11), tutte situate all’interno dell’area di vii grado mcs, mentre solo pochissime ricadono in area propriamente mesosismica. gran parte dei casi associabili a liquefazioni era già riportata in be r a r d i et al. (1991) e ga l l i (2000). tra i casi inediti, meritano di essere ricordati quelli avvenuti nella zona tra rosarno e melicucco e segnalati in una corrispondenza da reggio calabria del giornale d’italia del 18 settembre 1905, nella quale melicucco è erroneamente trascritto in melicuccà; il fenomeno viene così descritto: “… a melicuccà [melicucco] … lateralmente alla via nazionale che conduce a rosarno si osservano degli zampilli d’acqua. in contrada “annegato” un lungo tratto di terreno, estendendosi per circa 2000 metri quadrati, è coperto da una specie di fango cinereo; i crepacci sono frequentissimi e taluni hanno la forma di crateri romboidali, da cui sgorgano acqua e fango in grande abbondanza. questi crateri, ad una profondità di circa 50 centimetri, invece di seguire la perpendicolare, prendono risolutamente un’altra direzione, che pare debba essere parallela alla superficie del terreno. … in certi punti riscontransi sorgive filiformi e una quantità straordinaria di buche della forma di quelle che costruiscono le formiche. in contrada “scafapesca” sono delle fenditure lunghe 250 metri. nell’altra di “survareto” i crepacci hanno una larghezza di circa tre metri. in contrada “barcotto”, poi le acque di un fosso sono scomparse ricomparendo negli agrumeti vicini. alle “granatare” una sorgiva, pure scomparsa, è riapparsa nientemeno che ad una altezza di oltre 15 metri. …”. da notare la vastità degli effetti osservati in contrada annegato, dove il sottosuolo per un’ampia zona è andato evidentemente soggetto ad un fenomeno areale di liquefazione, risultandone coperto da acqua e depositi fuoriusciti da numerosi “crateri” non dissimili, nella descrizione, da quelli che si formarono 223 fig. 10 distribuzione dei fenomeni di probabile liquefazione e delle variazioni del regime idrico delle acque sotterranee. distribution of earthquake-induced liquefactions and others effects on the hydrological rate. il terremoto del 1905 in calabria: revisione della distribuzione ... nella stessa zona in occasione del terremoto del 5 febbraio 1783 (sarconi, 1784). molto diffusi furono gli effetti prodotti dal terremoto sul regime idrico delle acque sotterranee (fig. 10), effetti per lo più costituiti da variazioni di portata e in qualche caso di temperatura in numerose sorgenti, da comparsa o scomparsa di altre, da intorbidamenti delle acque notati soprattutto negli acquedotti, nelle fontane pubbliche ed anche nei corsi d’acqua. come si può osservare in figura, questi effetti si verificarono anche in aree interessate da intensità piuttosto modeste (vi grado mcs circa). numerose sono, poi, le descrizioni di rotture e fenditure nel terreno, alcune esplicitamente riconducibili a fenomenologie franose, altre associate a liquefazioni di sabbie e altre ancora di genesi incerta. a questo proposito è importante sottolineare che nessuna delle rotture di superficie prodotte dal terremoto, per geometria, lunghezza e rigetto è compatibile con fenomeni di fagliazione di superficie. l’assenza di tali fenomeni viene chiaramente indicata anche da me r c a l l i ( 1 9 0 6 ) , secondo il quale “pare che il terremoto calabrese non sia stato accompagnato da nessuna dislocazione permanente del suolo in senso orizzontale o verticale.”. da ricordare, tuttavia, un fenomeno particolare che si verificò lontanissimo dall’area epicentrale, lungo la costa ionica di cirò, dove si aperse una fenditura larga pochi centimetri, ma lunga circa un chilometro. la stessa si è riaperta numerose altre volte nel tempo, anche in assenza di qualsivoglia evidente causa esterna innescante, sino al luglio 2004, quando ha interessato, danneggiandolo, il centro abitato di cirò marina (galli et al., 2006b). nel complesso, l’effetto cosismico più frequente è rappresentato dai movimenti franosi, osservati in quasi un centinaio di località. in generale, tuttavia, si tratta quasi sempre di movimenti piuttosto limitati, distribuiti in tutta la calabria (fig. 11), con una maggiore incidenza nei versanti occidentali ed orientali della catena costiera, nei margini sud-occidentali della sila e nell’area del monte poro; abbastanza frequenti anche attorno ai massicci del le serre e dell’aspromonte. la scarsa presenza di estesi movimenti franosi ed in particolare di frane di scivolamento è forse da collegare al fatto che il terremoto avvenne a fine estate, al termine di un periodo secco. le frane più importanti furono tuttavia quelle che interessarono i centri abitati d i aiel lo calabro, di martirano e di triparni, in quanto concorsero in modo significativo al danneggiamento degli edifici e alla morte o al ferimento di numerose persone. ad aiello calabro (fig. 12) si verificò il distacco di grandi massi dallo sperone roccioso, alto circa trecento metri, soprastante al paese e su cui sorgeva il castello; i massi investirono varie case, distruggendole e provocando la morte di varie persone. da un sopralluogo effettuato da due tenenti dell’esercito (corriere della sera del 27 settembre 1905) risultò che lo sperone era anche interessato da una notevole spaccatura, con grave pericolo per il paese e per tutta la vallata sottostante. secondo testimonianze di contemporanei (de me d i c i, 1989), l’abitato di martirano fu interessato da più frane, tra le quali una enorme fece precipitare in basso parte della collina su cui sorgeva “il quartiere popolare chiamato verdesca”, che andò completamente distrutto (16 delle 17 vittime del comune martirano, infatti, erano abitanti di quel quartiere). secondo il quotidiano la tribuna del 19 settembre 1905 e de me d i c i (1989), il 18 settembre una forte replica si produsse un’altra grande frana, probabilmente nella stessa aree su cui sorgeva il rione verdesca. nelle campagne di triparni, secondo rizzo (1907), si produssero grandi fenditure nel terreno, una delle quali probabilmente interessò anche il centro abitato, dato che “la piazza del paese fu come inghiottita e si formò un precipizio”. tale precipizio era ben visibile anche nei giorni successivi, quando venne visitato dal ministro ferrarsi (giornale di sicilia dell’11-12 settembre 1905). altre frane avvennero in alcuni paesi dell’area mesosismica, contribuendo ad aumentarne il grado di distruzione; tra questi sono da ricordare mantineo, 224 fig. 11 distribuzione areale delle fratture nel terreno e delle frane in occasione del terremoto del 1905. location of landslides and surficial breaks occorre during the 1905 earthquake. p. galli & d. molin costruito lungo uno sperone roccioso, e fitili, san leo (vecchio) e zungri, costruiti, pro parte, sul ciglio di un antico terrazzo marino. 3.7 i possibili casi di amplificazione locale a prescindere dai danni conseguenti all’innesco di fenomeni gravitativi (frane), gli effetti di amplificazione locale del moto sismico possono divenire predominanti su quelli indotti dal solo scuotimento atteso su substrato rigido. un metodo speditivo, ancorché approssimativo, per stabilire se un luogo possa essere caratterizzato da frequenze predominanti è quello di registrare i microtremori indotti dalle oscillazioni della terra e di processarli secondo la tecnica di na k a m u r a ( 1 9 8 9 ; mu c c i a r e l l i et al., 1996; ga l l i e na s o, 2008). in taluni casi, conoscendo (o assumendo) la velocità delle onde di superficie (vs) dei terreni superficiali è possibile, mediante la cosidetta legge del quarto dell’onda ( v s =ν*4h) ricavare anche informazioni sullo spessore (h) di questi terreni, ovvero sulla profondità del cosiddetto bedrock sismico. e’ stato dunque condotto un rilievo speditivo in alcuni dei paesi colpiti dal terremoto, al fine di verificare se sussistessero indizi di amplificazione locale dovute alle condizioni di sito. sono stati investigati sia abitati con elevato risentimento macrosismico, sia altri generalmente limitrofi con i primi, ma con un basso grado mcs, per un totale di 16 paesi. in alcuni di questi sono state condotte più misure, ubicate in diverse zone degli stessi. la maggior parte dei paesi del vibonese è costruita sulla superficie dei terrazzi marini del monte poro. solo alcuni sono ubicati su cr inal i, come mantineo e triparni o martirano nel lontano reventino. in genere, i terrazzi sono scolpiti direttamente sul substrato granitico e/o sulle coperture trasgressive mioplioceniche (generalmente in giacitura piano-parallela), mostrando esigui o nulli spessori di depositi marini e coltri metriche alluvio-colluviali, anche sulle superfici sommitali. i risultati ottenuti sono stati, nei limiti della validità del metodo e dell’esiguo numero di misure effettuate, abbastanza sorprendenti. a parte alcune conferme sulla mancanza di frequenze predominanti di abitati costruiti direttamente su roccia, come tropea che non mostra alcun picco in nessun campo di frequenze e che non ebbe, di fatto, distruzioni (né nel 1905, né, in genere, nei terremoti precedenti. fig. 13a) molti luoghi, per i quali era lecito attendersi un effetto di sito, non hanno mostrato picchi significativi nel campo delle frequenze di interesse ingegneristico. zammarò, per esempio, dove si registrò uno dei più alti livelli di distruzione (x-xi mcs), e piscopio (ix-x) mostrano entrambi un picco molto chiaro e stabile nelle diverse misure intorno a 0.9 hz (fig. 13b), corrispondente, com’è facile immaginare, ad edifici dotati di un lungo periodo di oscillazione (~1 sec.), ben diversi dalle basse casette che andarono distrutte allora (fig. 2). in questo caso, il picco potrebbe corrispondere ad una discontinuità abbastanza profonda, quale quella realmente esistente a circa 100 m al di sotto del terrazzo ove sorge zammarò, tra i calcari miocenici sottostanti e la successione argilloso-sabbiosa pliocenica (vs~400 m/sec) su cui il terrazzo stesso è scolpito. triparni (x-xi mcs), edificato lungo un crinale calcareo-arenaceo, mostra un picco ricorrente tra le frequenze di 1.8-2.5 hz, corrispondente ad edifici troppo alti (15-25 m) rispetto a quelli esistenti all’epoca, rendendo quindi poco verosimile la correlazione tra picco d’amplificazione e distruzioni. stesse considerazioni possono essere fatte per favelloni, il cui picco è stabile intorno a 2.2 hz. sul ciglio di un terrazzo di fronte alle rovine di briatico vecchio (abbandonato in seguito al terremoto del 1783), sorgeva san leo vecchio, anch’esso raso al suolo (x mcs) ed abbandonato a seguito del terremoto del 1905. le misure effettuate mostrano tutte una funzione addirittura piatta (fig. 13c), a significare l’assenza di amplificazione in tutto lo spettro, così come nella vicina e scomparsa villa lapa (x mcs), che seguì pari destino. in entrambe le situazioni, il terrazzo è direttamente scolpito sul substrato argilloso-sabbioso. d’altra parte parghelia (ix-x mcs), a soli due chilometri da tropea, mostra, in quattro diversi punti dell’abitato, un picco ben evidente tra le frequenze di 5.8 e 8.4 hz (fig. 13d). tali frequenze, in campo ingegneristico, sono compatibili con edifici ad uno o due piani e potrebbero spiegare l’elevato l ivel lo di distruzione proprio delle casette più basse rispetto agli edifici più alti e al campanile della chiesa, tuttora in piedi. così anche per zaccanopoli (ix-x mcs), che ha mostrato un analogo picco tra 7-8 hz. in questi casi, può avere 225 figura 12 ajello calabro: frana per distacco di grossi massi (al centro della foto) dalla rupe (sullo sfondo) che sovrasta il centro abitato. mega-rock avalanche inside the houses of ajello calabro (central calabria). note the enormous boulders fallen from the cliff visible in the background. il terremoto del 1905 in calabria: revisione della distribuzione ... avuto un ruolo decisivo il forte contrasto di impedenza tra il bedrock granitico e la copertura sabbioso-conglomeratica del terrazzo (vs~200-300 m/sec), che, nel caso di parghelia, è resa più potente (~10 m) dalla presenza del piccolo conoide su cui il paese è in parte costruito. anche zungri (x mcs), mostra un picco intorno a 6 hz, corrispondente ad edifici di 1-2 piani, come la maggior parte di quelli effettivamente crollati. mesiano, invece, posto a quattro chilometri da zungri e che non ebbe quasi danni (vi mcs), mostra uno spettro abbastanza piatto. di fatto esso sorge, a meno di una sottile copertura continentale, direttamente su granito. a san giovanni (ix-x mcs), situato tra zungri e la costa tirrenica, gli unici edifici antichi superstiti sono piccole case ad un piano costruite con mattoni di fango essiccato. le misure condotte hanno evidenziato un picco netto a 3.5 hz, che corrisponde ad edifici di almeno due-tre piani, paragonabili a quelli effettivamente crollati. il paese sorge su un terrazzo scolpito su sabbie mioceniche, spesse localmente 30-40 m, al di sopra del b e d r o c k granitico. anche in questo caso, il forte contrasto di impedenza tra graniti e sabbie (vs~400500 m/sec) può avere giocato un ruolo dominante nella definizione del picco. per riassumere, le misure effettuate hanno mostrato una discreta correlazione tra il contenuto in frequenza e livello di danno solo in qualce paese del settore occidentale del monte poro, mentre per la zona nordorientale l’elevatissimo grado di danneggiamento sembra essere dovuto al reale scuotimento indotto dal terremoto, pur in assenza di particolari effetti di sito 8 . 3.9 parametrizzazione del terremoto del 1905 epicentro. sulla base del piano quotato elaborato in questo lavoro e delle considerazioni di carattere sismotettonico, il terremoto ha avuto probabilmente origine nel tirreno, poco ad ovest del golfo di sant’eufemia e a nord del litorale di briatico. i dati strumentali dell’epoca non sono, ad oggi, utilizzabili al fine di effettuare stime precise delle coordinate epicentrali; tuttavia, il baricentro dell’area di vii-viii mcs (fig. 8) indica, grossomodo, un punto con coordinate 38.8 n e 15.7 e. tale localizzazione è poco a ne di quella sperimentalmente calcolata da michelini et al. (2006; 38.6 n e 15.4 e) che, tenuto conto della grande estensione della sorgente, potrebbe rappresentare l’enucleazione della rottura sul piano di faglia. magnitudo.si è già detto che la magnitudo è la più elevata mai calcolata per un evento strumentale in italia. duda (1965) fornisce la stima più alta tra quelle pubblicate in letteratura (ml=7.9), includendo l’evento in una lista dei più forti terremoti mai avvenuti tra il 1897 ed il 1964. karnik (1969), sulla base di due registrazioni, calcola ml=7.3 (ml=7.6 sulle onde di volume ph e sh, che considera, tuttavia, sovrastimata), mentre riuscetti e shick (1975) pubblicano un valore di m=7.0. una suc226 8resta inteso che solamente incrociando le funzioni di amplificazione ottenute tramite un’estesa campagna di registrazione di microtremori con i dati geologico-tecnici di sottosuolo di ciascun paese sarebbe possibile addivenire a risultati più certi e definitivi. fig. 13 a, funzione di amplificazione ottenuta col metodo dei microtremori in vicinanza del duomo normanno di tropea. la città è fondata direttamente su un terrazzo marino scolpito su calcareniti e lo spettro non mostra particolari picchi di amplificazione in nessun campo di frequenze. b, funzione di amplificazione ottenuta a zammarò (x-xi mcs). il picco evidente intorno a 0.9 non ha valenza ingegneristica e non può aver contribuito alla distruzione dell’abitato. un picco analogo è stato rilevato a piscopio (ix-x mcs). c, funzioni di amplificazione ottenute a san leo vecchio. come per tropea anche questo sito non mostra frequenze predominanti; nonostante ciò il paese fu raso al suolo e quindi abbandonato. d, funzioni di amplificazione ottenute a parghelia. i diversi picchi tra le frequenze 5.8-8.4 potrebbero giustificare l’elevata distruzione di casette a 1-2 piani della vecchia parghelia. a, amplification function obtained by meand of microtremors analyses near the norman cathedral of tropea (is=7-8), very close to the possible source. the town is founded on a marine terrace directly carved on calacarenites, as shown by the absence of any frequency peak. b, amplification function obtained for zammarò (is=10-11 mcs). the peak at 0.9 hz has not any engineering meaning (it would match with very high building) as far the level of disruption reached by this village is concerned. c, amplification function in san leo vecchio (is=10 mcs); similarly to tropea this site shows no amplification in any frequency range, but conversely, this village was destroyed and abandoned. d, amplification function at parghelia (is=9-10 mcs). the different peaks between 5.8-8.4 hz could account for the high level of disruption of 1-2 store buildings in the old settlement of this village. p. galli & d. molin cessiva rivalutazione è in margottini et al. (1993), i quali, sempre sulla base di due registrazioni, calcolano una ms=7.47. tale valore è stato mutuato da ca m a s s i e stucchi (1997) e da cpti99, mentre in cpti04 esso è stato parametrizzato assumendo il valore ibrido di “ma” di cpti99 (maw=7.06). a titolo di confronto, abbiamo tentato di stimare il valore della magnitudo anche sulla durata della più vicina registrazione (ischia, a ~230 km con durata di ~1h25’). pur nella consapevolezza dei limiti insiti in questo metodo relativamente al caso in oggetto (a causa dell’eccessiva distanza e dell’alto valore di magnitudo), tramite la formula di lee et al. (1972: md= -0.87+2logtsec+0.0035dkm), abbiamo calcolato md=7.46, un valore di fatto coincidente con quello di margottini et al. (1993). infine, la magnitudo stimata a partire dalla distribuzione ed intensità degli effetti macrosismici è stata valutata me=6.88 in cpti99. tale valore è salito a mw=6.73 in cpti08, ed a mwm=7.26 utilizzando un diverso algori tmo di inversione macrosismica. comunque, data la netta apertura verso mare del piano quotato, la verosimile localizzazione dell’epicentro stesso a mare e la probabile notevole profondità ipocentrale, non abbiamo creduto applicabile l’utilizzo di alcun algoritmo (p.e., bakun e wentworth, 1997) alla distribuzione delle intensità da noi ottenuta. i n t e n s i t à . similmente, l’intensità epicentrale (io) non è secondo noi definibile, in quanto l’epicentro ricade in mare e la distribuzione delle intensità nel settore a terra più fortemente colpito (area di briatico-cessanitivibo valentia; is≥x grado in sei casi) risulta molto irregolare con presenza di vari punti con is ~ix grado e, in qualche caso, inferiore all’viii mcs 9 . profondità. a parte rizzo (1906a) che, sulla base delle velocità di propagazione delle onde sismiche, fornisce un valore della profondità ipocentrale di circa 50 km, non esistono stime strumentali attendibili sulla profondità dell’evento. in mancanza di altri dati, è interessante notare che me r c a l l i (1906), sintetizzando i racconti dei testimoni in zona mesosismica, descrive chiaramente che il terremoto fu avvertito in tre fasi ben distinte. la prima con una spiccata componente verticale, la seconda ondulatoria e la terza, responsabile delle distruzioni, vorticosa. stante la diversa velocità di propagazione delle onde p e s, assumendo che la fenomenologia delle prime due fasi descritte corrisponda, rispettivamente, agli impulsi delle onde di volume e di taglio (il terzo, distruttivo, alle onde di superficie), l’intervallo tra i due arrivi potrebbe dare informazioni sulla distanza tra l’ipocentro e la zona di osservazione (i.e., i paesi del monte poro). purtroppo, me r c a l l i ( 1 9 0 6 ) riporta la durata totale dello scuotimento (circa 40’’; vedi anche rizzo, 1907; baratta, 1906) e l’intervallo tra le prime due fasi (1’’-2’’; vedi anche baratta, 1906), ma non la durata della prima fase. stimando per difetto in qualche secondo (3’’-5’’) la durata di quest’ultima (percepita dagli abitanti di monteleone come un triplice sussulto; ba r a t t a, 1906) e sommando l’intervallo occorso per l’arrivo della seconda fase, si ottiene un ritardo corrispondente ad una distanza minima di 50 km tra la sorgente e i paesi del monte poro (i ritardi p-s valgono, grossolanamente 7-8 km/sec.). se il monte poro fosse realmente l’epicentro del terremoto, questa distanza corrisponderebbe alla profondità del terremoto; ma assumendo che il vero epicentro sia stato poco al largo della costa, il valore minimo ottenuto deve essere decurtato di qualche chilometro (i.e., la distanza orizzontale). in sintesi, volendo dare credito a questa ricostruzione (ed a ri z z o, 1906a), il terremoto ebbe comunque un origine profonda, se rapportato ai normali terremoti crostali dell’appennino (10-20 km). 4. ipotesi sismogenetiche e conclusioni si è detto che sulla sorgente sismogenetica del terremoto del 1905 non esiste un’ipotesi convincente o basata su osservazioni certe. né esistono dati geologici sull’attività tardo pleistocenica-olocenica delle faglie del monte poro né, tantomeno, dati paleosismologici. neppure può essere ritenuta attendibile la localizzazione della sorgente riportata in diss wo r k i n g gr o u p (2006), basata sull’inversione del piano quotato contenuto in boschi et al. (2000) e centrata, di conseguenza, sul monte poro stesso. sicuramente, considerando i valori calcolati per la magnitudo (7.9�m�7.3), la sorgen te deve avere avuto dimensioni ragguardevoli, non meno di 50 km di lunghezza, il doppio dell’intero promontorio vaticano. di conseguenza, considerate sia le notizie (negative) raccolte relativamente agli effetti di superficie, che la mancanza di indizi sull’attività recente delle faglie normali del monte poro, è possibile escludere che il terremoto sia stato originato da qualcuna di queste. inoltre, in caso di terremoto crostale legato a faglie dirette, una così elevata energia, oltre ad estesi fenomeni di fagliazione di superficie (non verficatisi, come detto), avrebbe generato un livello di distruzione in area epicentrale (in genere nell’h a n g i n g w a l l d e l l a faglia) molto più vasto ed omogeneo di quello osservato, senza continue cadute e risalite del grado di intensità. e’ più probabile, quindi, che la sorgente sia stata sufficientemente profonda da non provocare né fagliazione di superficie né distruzione omogenea in area epicentrale. d’altra parte, la presenza di blande onde di maremoto è forte indizio di deformazione cosismica del fondo marino. tuttavia, gli effetti descritti (estensione ed altezza del run-up; platania, 1907), non sono certo compatibili con una fagliazione sottomarina lunga decine di chilometri e, presumibilmente, con rigetti maggiori di un metro, come quelli associabili ad una faglia crostale normale di m>7 10 . in sostanza, mentre è ragionevole pensare che la sorgente sia effettivamente ubicata a mare 1 1 e sia capace, quindi, di indurre deformazioni permanenti istantanee del fondo, è di nuovo necessario ritenere che sia stata sufficientemente profonda da non generare fagliazione estesa dello stesso. alla luce di quanto sopra esposto, è possibile ora 227 9per eventuali esigenze di calcolo della pericolosità sismica regionale, a nostro avviso il valore a cui fare riferimento potrebbe essere io=xi mcs. il terremoto del 1905 in calabria: revisione della distribuzione ... 10basti pensare all’altezza devastante raggiunta dal maremoto del 1908, con run-up sino a 9 m (platania, 1909). 11a questo proposito è interessante notare che, a parte le localizzazioni epicentrali nel golfo di sant’eufemia (ri u s c e t t i e schick, 1975; postpisch, 1985), un riesame dei dati strumentali riprocessati con specifiche tecniche (michelini et al., 2006) ha collocato al largo di capo vaticano l’epicentro, o meglio, l’enucleazione della rottura lungo la struttura del terremoto. avanzare un’ipotesi inedita, secondo la quale la sorgente del terremoto del 1905 potrebbe essere ubicata nella parte superiore dello slab litosferico ionico in subduzione verso nw. va ricordato che raramente i terremoti intraslab sono presi in considerazione nella valutazione della pericolosità sismica. tuttavia, quelli che avvengono entro poche decine di chilometri di profondità, contrariamente a quelli molto profondi 12 , possono mantenere un potere distruttivo anche a grandi distanze dall’ipocentro. per esempio, in america latina i terremoti intraslab hanno provocato nello scorso secolo molti più danni e vittime dei terremoti interplacca 13 . nel 1905, la rottura potrebbe avere interessato la parte superiore dello s l a b in un’area compresa tra il golfo di sant’eufemia e l’o f f s h o r e di capo vaticano, probabilmente nella zona di massima flessura dello slab stesso e ad una profondità indicativa di 40-50 km (figg. 8, 14). tuttavia, possiamo solo immaginare quale sia stata l’origine della rottura all’interno della litosfera in subduzione. e’ possibile, innanzitutto, escludere un sovrascorrimento connesso a zone di forte accoppiamento tra la placca a tetto e a letto (per esempio sul piano basale di scollamento interno alla transizione fragile-duttile del prisma di accrescimento), da immaginarsi, nel caso, sempre sul versante ionico della calabria. procedendo per esclusione, si potrebbe pensare ad altri diversi meccanismi, tra cui: • una zona di taglio trasversale nello slab, collegata alla profonda discontinuità che la tomografia sismica e la distribuzione dei terremoti evidenziano a nord e sud della stretta di catanzaro (p.e., una tear fault profonda); • la distensione d o w n d i p dovuta allo s l a b p u l l n e l l a porzione superiore della subduzione a sud della stretta di catanzaro; • nel caso tale forza non sussistesse più, compressione down-dip a cui lo slab sarebbe allora interamente sottoposto nella sua discesa “forzata” nel mantello, forse accentuata dalla spinta orizzontale che que228 st’ultimo esercita nel suo movimento relativo verso est (doglioni et al., 1999); • la distensione a cui la parte superiore della placca è sottoposta nella zona di flessura anzidetta (p.e., a causa dei meccanismi di flexural extension descritti in bradley e kidd, 1991; seno e yamanaka, 1998). di fatto, anche se generalmente i grandi terremoti distruttivi legati ai processi di subduzione sono quelli che avvengono tra placche in forte convergenza tra loro, forti eventi connessi al semplice bending dello slab sono altrettanto noti nel mondo (ka n a m o r i, 1971; lynnes e lay, 1988; seno e yamanaka, 1998). tra l’altro, seppur possano essere cessati i processi di convergenza che sono stati alla base della subduzione ionica, lo slab del basso tirreno è sicuramente uno di quelli che presenta la maggior curvatura e pendenza (~70°), oltre che un impressionante arretramento flessurale dell’asse della flessura. inoltre, per quanto forti eventi associati a t s u n a m i s siano avvenuti sia per eventi di d o w n d i p compression (e down-dip extension) che di taglio intras l a b 1 4 , considerando l’elongazione ne-sw dell’area di massimo danneggiamento, è più ragionevole pensare ad una sorgente similmente orientata piuttosto che ad una struttura subverticale trascorrente quale, appunto, un’ipotetica tear fault nel golfo di sant’eufemia. e tra queste, per motivi geometrici, una legata al b e n d i n g dello slab è forse quella che meglio giustifica il coinvolgimento anche della crosta sovrastante la piastra litosferica e, quindi, la deformazione del fondo marino. a questo proposito, volendo dar credito alla soluzione del meccanismo focale del terremoto del 1905 fornita da riuscetti e schick (1975; se ne veda la proiezione nella sezione perpendicolare allo s l a b in fig. 14), si può osservare che gli assi t sono contenuti nello slab, allineandosi alla direzione della sua immersione (estensione down-dip), con un possibile piano di taglio subverticale ribassante ad ovest. tale cinematica è, inoltre, coerente alle polarità del maremoto (innalzamento del livello marino nel footwall e ritiro nell’hangingwall). concludendo, dunque, qualunque ne sia stato il meccanismo i n t r a s l a b, la concomitanza della grande estensione della sorgente e la sua profondità, unite all’elevato contenuto di energia nelle alte frequenze potrebbero avere: • causato le distruzioni nei paesi più prossimi alla sorgente (area del monte poro) ed in particolare delle abitazioni più basse e nei luoghi caratterizzati da coperture sottili soffici su substrato roccioso (entrambi più sensibili alle alte frequenze; i.e., 3-8 hz); • generato una vasta area di danneggiamento regionale, orientata ne-sw e parallela alla sorgente ed all’estensione laterale dello slab (con isolate riprese dell’intensità dovute all’innesco di fenomeni franosi, come ad ajello, martirano ed altri luoghi); • indotto un’estesa, blanda deformazione bipolare del fondo marino, responsabile del debole maremoto registrato sulle coste tirrenica della calabria, con primi impulsi positivi nel lato rialzato (costa del vibonese) e negativo in quello ribassato (zona di scalea). 1 2per esempio, il citato evento nel basso tirreno del 1938, avvenuto a 290 km di profondità. 13sempre in america latina, nel 1931 un terremoto intraslab di m=7.8 ubicato a 40 km di profondità, causò gravissime distruzioni nello stato di oaxaca, in messico (singh et al., 2000). e così anche in occasione dei terremoti di orizaba del 1974 (m=7.3 a 82 km di profondità), di huajuapan de leon del 1980 (m=7.1, a 65 km) e di tehuacan del 1999 (m=7.4 a 40 km), tutti caratterizzati da cinematica normale intraslab. in giappone, nel 2003, un terremoto i n t r a s l a b a 70 km di profondità (mw=7.0) ha prodotto un risentimento in un area vastissima ed un valore di pga superiore ad 1g in cinque stazioni accelerometriche poste a 100 km dall’epicentro (as s i m a k i e st e i d l, 2007). infatti, a parità di magnitudo calcolata, questi terremoti hanno un livello di energia nel campo delle alte frequenze sistematicamente più alto, giustificando così i maggiori effetti macrosismici che essi possono comportare rispetto agli altri terremoti (si n g h et al., 2000; ki r b y, 2001; ch o y et al., 2002; iglesias et al., 2002). questa “anomalia” nel contenuto in alte frequenze sembra essere legata al maggior valore dello stressdrop alla sorgente, che i terremoti intraslab possiedono rispetto agli altri (atkinson e hanks, 1995). tuttavia, le sorgenti di questi eventi rimangono un’incognita per i “geologi del terremoto”, in quanto difficilmente rompono in superficie e, ancor meno, sembrano riconducibili ad una singola faglia, ma piuttosto alla deformazione di più strutture (kirby e wang, 2002). 1 4per quest’u ltimo caso, si rammenta il terremoto del 30/11/1987 in alaska (ms=7.4), con probabile rottura di una tear fault nella placca pacifica in subduzione (quintanar et al., 1995) e generazione di uno tsunami lungo le coste nordamericane con ampiezza massima di circa 0.5 m. p. galli & d. molin 229 fig. 14 immagine schematica dello slab litosferico ionico in subduzione al di sotto del bacino tirrenico attraverso la calabria meridionale (~38.5° n). la sismicità (proiettata in una fascia di 50 km a cavallo della sezione) è desunta da postpischl (1985; intervallo sino al 1980), dalla rete temporanea istallata negli anni ’90 dall’ismes nella piana di gioia tauro, dal catalogo csi (ca s t e l l o et al., 2006) e ingv (2003-2004). nel settore ionico è stato assunto uno spessore litosferico di ~90 km (~30 km in quello tirrenico), con una crosta di 20-25 km (contro i 10-15 km nel settore tirrenico), in accordo con pontevivo e panza (2006). sono evidenziati i terremoti di elevata energia del 1910, 1956 e 1938; inoltre, a titolo esemplificativo, oltre a quello del 1938 (da anderson e jackson, 1987), sono riportati i meccanismi focali (cmt) ridotti sul piano della sezione degli eventi profondi del 5 maggio 2005 e 26 ottobre 2006 (entrambi distintamente risentiti in superficie). questi eventi, come molti altri ad analoga profondità, mostrano compressione d o w n d i p. il meccanismo del 1905 è, invece, mutuato da ri u s c e t t i e sc h i c k (1975). la distribuzione della sismicità e dello stress in atto in questo limitato settore dello s l a b a sud della stretta di catanzaro potrebbero indicare ancora trazione attiva nella parte sommitale (slab pull) o, quantomeno, flessurazione ed arretramento della cerniera e compressione certa più in profondità (down-dip compression). nella zona di cerniera dello slab è possibile che, a causa della pronunciata flessura (b e n d i n g), accentuata forse dal movimento relativo del mantello verso ~e (vedi do g l i o n i et al., 1999), predominino meccanismi di f l e x u r a l e x t e nsion, associati a grandi rilasci di energia. forse il terremoto del 1928 ed anche quello del 1905 sono originati in questa zona, mentre la crosta sovrastante è interessata da distensione nw-se, guidata dalle grandi faglie normali che bordano i massicci delle serre e dell’aspromonte, responsabili dei terremoti del febbraio 1783. sketch of the subducting ionian lithosphere beneath the calabrian arc and the tyrrhenian basin (see bootom-right index map for profile location). seismicity (projected in a 50-km wide belt across the section) is from postpischl (1985; up to 1980), from enel-ismes gioia tauro network (period of the 90s), from csi (ca s t e l l o et al., 2006) and ingv (2003-2004). according to po n t e v i v o and pa n z a (2006), in the ionian sector (right) we absumed a ~90 km-thick lithosphere (30 km in the tyrrhenian area), with a crust 20-25 km-thick (vs 10-15 km in the tyrrhenian area). note the m>6.2 deep earthquakes of 1910, 1956 and 1938. besides the 1938 focal mechanism (an d e r s o n and ja c k s o n, 1987), the may 5, 2005 and october 26, 2006 cmt solutions are also shown (all mechanisms are viewed on the section plane); both these events were strongly felt at surface in sicily and calabria. the 1905 focal mechanism is from riuscetti and schik (1975). the seismicity and stress distribution in this sector of the slab (i.e., south of the catanzaro straits) may indicate active slab-pull in the upper portion, whereas down-dip compression is, instead, certain at larger depth. in the hinge zone of the slab (just in the tyrrhenian offshore of calabria), which should be subjected to a fast se-retreating, due to the strong bending of the upper sector of the slab, flexural-extension mechanisms should dominate, being associated to large energy releases. perhaps, the 1928 earthquake, and maybe the 1905 too originated in this region due to flexural-extension processes. conversley, the overlaying crust is here subjected to nw-se extension, driven by the primary normal faults which bounds the serre and aspromonte range, and which were responsible for the catastrophic earthquakes of february 5 and 7, 1783 (see in galli et al., 2007). il terremoto del 1905 in calabria: revisione della distribuzione ... ringraziamenti si ringraziano carlo doglioni e paolo scandone per aver condiviso con noi le loro idee sulla subduzione tirrenica e per averci incoraggiato in merito alla nostra ipotesi sismogenetica. grazie al tetsuzo seno per le informazioni sui meccanismi di b e n d i n g dello s l a b. grazie a veronica scionti e ad antonio tripodi, per averci facilitato le ricerche nell’archivio di vibo valentia. grazie anche a mirella sebastiano, per averci messo al corrente delle sue ricerche in archivio centrale di stato, a felice muscaglione per le notizie sul vibonese e ad annarita peperoni per le ricerche storiche sui terremoti profondi. grazie a gaetano de luca, che ci ha aiutato a calcolare la magnitudo sulla durata del sismogramma. grazie infine al personale della biblioteca della camera dei deputati, per l’efficienza e la disponibilità con la quale ci hanno assisitito. claudia piromallo (ingv) ha generosamente elaborato le sezioni tomografiche presentate. due anonimi e benevoli revisori hanno, infine, fornito utili e costruttivi suggerimenti nonché numerose correzioni, non solo di forma. tyrrhenian sea. in: k.a. kastens j. mascle et al. (eds.): proceedings of the ocean drilling program, scientific results, 107, 75-92. berardi r., margottini c., molin d. and parisi a. (1991) soil l iquefaction: case histor ies in italy. tectonophysics, 193, 141-164. bianconcini p. (1906) relazione del comitato di soccorso emiliano-romagnolo per il terremoto in calabria delli 8 settembre 1905. pp. 141. bologna. bo s c h i e., fe r r a r i g., ga s p e r i n i p., gu i d o b o n i m . , sm i r i g l i o g. e va l e n s i s e g . (a cura di) (1995) catalogo dei forti terremoti in italia dal 461 a.c. al 1980. istituto nazionale di geofisica sga storia geofisica ambiente, pp. 973. ozzano emilia. bo s c h i e., gu i d o b o n i m., fe r r a r i g., ma r i o t t i d . , va l e n s i s e g. e ga s p e r i n i p . (a cura di) (2000) catalogne of strong italian earthquakes from 461 b.c. to 1997. annali di geofisica, 4 3(4), august 2000, cd-rom. bo s c h i e., gu i d o b o n i m., fe r r a r i g., va l e n s i s e g. e gasperini p. (a cura di) (1997) catalogo dei forti terremoti in italia dal 461 a.c. al 1990. istituto nazionale di geofisica sga storia geofisica ambiente, pp. 644. ozzano emilia. bradley d.c., kidd w.s.f. (1991) flexural extension of the upper continental crust in collisional foredeeps. geol. soc. of am., 103, 1416-1438. caloi p. e giorgi m. (1951) studio del terremoto delle isole lipari del 13 aprile 1938. annali di geofisica, 4, 9-26. ca m a s s i r. e st u c c h i m. (a cura di) (1997) nt4.1 un catalogo parametrico di terremoti di area italiana al di sopra della soglia del danno. versione nt4.1.1 luglio 1997, pp. 66. milano. camassi, r. v. castelli (2004) looking for new earthquake data in the 17th-18th cent. european newssellers network. j. of earthquake eng., 7, 1-25. carobene l. (2003) genesi, età, sollevamento ed erosione dei terrazzo marini di crosia-calopezzati (costa ionica della calabria-italia). il quaternario, 16, 43-90. carrozzo m.t., cosentino m., ferlito a., giorgetti f., pa t a n è g. a n d ri u s c e t t i m. (1975) e a r t h q u a k e s catalogne of calabria and sicily (1783-1973). cnr, quaderni de “la ricerca scientifica”, 9 3, pp. 216. castello b., selvaggi g., chiarabba c., amato a. (2006) csi catalogo della sismicità italiana 1981-2002, versione 1.1. ingv-cnt, roma, http://www.ingv.it/csi/ catalano r., doglioni c. and merlini s. (2000) on the mesozoic ionian basin. geophys. j. int., 1 4 3, 1-24. catalano r., monaco c., & tansi c. (1993) pleistocene strike-slip tectonics in the lucanian apennine (southern italy). tectonics, 12, 656–665. ca v a s i n o a. (1931) note sul catalogo dei terremoti distruttivi dal 1501 al 1929 nel bacino del med i t e r r a n e o. pubblicazioni della commissione italiana per lo studio delle grandi calamità, 2, 25-60. ca v a s i n o a. (1935) i terremoti d’italia nel trentacinquennio 1899-1933. mem. r. uff, centr. meteor. e geof., 4, s. 3, appendice, pp. 266. cd (1906a) camera dei deputati. legislatura xxii, sessione 1904-909, raccolta degli atti stampati per ordine della camera, vol. 14, n. 387, disegno 230 p. galli & d. molin il piano quotato completo del terremoto – edito da ga l l i e mo l i n (2007), ma non riproducibile in questa sede per evidenti motivi di spazio – comprensivo dell’intensità mcs e delle coordinate per 875 località, oltre ad altri dati analitici sul danneggiamento, sulla mortalità e sugli effetti ambientali, è disponibile al sito internet: http://ilmiolibro.kataweb.it/libro.asp?id=14201 5. bibliografia citata agamennone g. (1938) studio macrosismico del terremoto calabro siculo del 13 aprile 1938. boll. soc. sism. ital., 36, 83-98. am a t o a., al e s s a n d r i n i b., ci m i n i g.b, fr e p o l i a. a n d selvaggi g. (1993) active and remnant subducted slabs beneath italy: evidence from seismic tomography and seismicity. annali di geofisica, 36, 201-214. amodio morelli l., bonardi g., colonna v., dietrich d., gi u n t a g., ip p o l i t o f., li g u o r i v., lo r e n z o n i s . , pa g l i o n i c o a., pe r r o n e v., pi c c a r r e t a g., ru s s o m., sc a n d o n e p., za n e t t i n lo r e n z o n i e. , & zu p p e t t a a. (1976) l’arco calabro-peloritano nell’orogene appenninico maghrebide. mem. soc. geol. it., 17, 1-60. anderson h., jackson j. (1987) the deep seismicity of the tyrrhenian sea. geophys. j. r. astron. soc., 91, 613-637. anelli a. (2005) a ricordo del centenario 1905-2005 – il catastrofico terremoto dell’8 settembre 1905. in “ricordo del catastrofico terremoto dell’8 settembre 1905, amm. comunale di castrolibero, pp. 16. assimaki d. e steidl j. (2007) inverse analysis of weak and strong motion downhole array data from the mw7.0 sanriku-minami earthquake. soil dynamics and earthquake engineering, 27, 73-92. atkinson g.m. e hanks t.c. (1995) a high-frequency magnitudo scale. bull. seism. soc. am. 8 5, 825–833. ba k u n w.h. e we n t w o r t h c.m. (1997) e s t i m a t i n g earthquake location and magnitude from seismic i n t e n s i t y d a t a. bull. seism. soc. am. 8 7, 15021521. ba r a t t a m. (1906) il grande terremoto calabro dell’8 settembre 1905. osservazioni fatte nei dintorni di monteleone. atti della società toscana di scienze naturali in pisa, memorie, 22 (1906), 57-80. baratta m. (1906a) il grande terremoto calabro dell’8 settembre 1905. alcune considerazioni sulla distribuzione topografica dei danni. pisa. estratto da atti soc. tosc. sc. nat., 16( 1906-1907), pp. 8. ba r a t t a m. (1906b) i terremoti di calabria. b o l l e t t i n o della società geografica italiana, a. 40, s. iv, 7(1906), 432-459. baratta m. (1910) la catastrofe sismica calabro-messinese (28 dicembre 1908). 2 voll. roma. ba r a t t a m. (1907) le nuove costruzioni in calabria dopo il disastroso terremoto dell’8 settembre 1905. boll. soc. sism. it., 12, 249-337. be c c a l u v a l., bo n a t t i e., du p u y c., fe r r a r a g . , in n o c e n t i f., lu c c h i n i f., ma c e r a p., pe t r i n i r . , rossi p.l., serri g., seyler m., e siena f. (1990) geochemistry and mineralogy of volcanic rocks from odp sites 650, 651, 655, and 654 in the di legge calandra-luzzati: conversione in legge dei regi decreti 11, 15 e 22 febbraio 1906, nn. 69, 70 e 71, concernenti la sospensione della riscossione della 1a rata delle due imposte fondiarie nei comuni della calabria danneggiati dal terremoto [del settembre 1905] e la inclusione di nuovi comuni nell’elenco dei danneggiati. seduta del 21 marzo 1906. roma 1909. cd (1906b) camera dei deputati legislatura xxii, sessione 1904-909, raccolta degli atti stampati per ordine della camera, vol. 15, n. 518, proposta di legge d’iniziativa del deputato larizza, aggiunta all’elenco dei comuni danneggiati annesso alla legge a favore della calabria. seduta del 6 luglio 1906. roma, 1909. cd (1906c) camera dei deputati. legislatura xxii, sessione 1904-909, raccolta degli atti stampati per ordine della camera, vol. 15, n. 518-a, proposta di legge d’iniziativa del deputato larizza, aggiunta all’elenco dei comuni danneggiati annesso alla legge a favore della calabria. seduta del 6 luglio 1906. roma, 1909. cd (1906d) camera dei deputati. legislatura xxii, sessione 1904-906, doc. vii i quinquies, documenti – disegni di legge e relazioni, regio decreto col quale si dispone che sia sospesa la riscossione della prima rata 1906 delle imposte e sovrimposte sui terreni e sui fabbricati in comuni danneggiati dal terremoto. dato a roma, addì 22 febbraio 1906. roma 1909. cd, 1906e) camera dei deputati. legislatura xxii, sessione 1904-906, doc. vii i quinquies, documenti – disegni di legge e relazioni, regio decreto che autorizza la sospensione della riscossione della 1a rata 1906 delle imposte e sovrimposte sui terreni e sui fabbricati in comuni danneggiati dal terremoto. dato a roma, addì 15 febbraio 1906. roma 1909. cd (1907) camera dei deputati. legislatura xxii, sessione 1904-909, raccolta degli atti stampati per ordine della camera, vol. 15, n. 518-a, relazione della commissione composta dai deputati: morando, turco, campagna, ventura, caputi, valentino, scaglione, dagosto e larizza, sulla proposta di legge d’iniziativa del deputato larizza. aggiunta all’elenco dei comuni danneggiati [dal terremoto del settembre 1905] annesso alla legge a favore della calabria. seduta del 27 febbraio 1907. roma 1909. cere (1906) resoconto finanziario del comitato esecutivo di reggio-emilia a favore delle vittime del terremoto in calabria nell’anniversario della sciagura. pp. 14., reggio-emilia. chiarabba c., covane l., di stefano r. (2005) a new view of italian seismicity using 20 years of instrumental recordings. tectonophysics, 3 9 5, 251– 268. ch o y g.l., bo a t w r i g h t j.h. e ki r b y s.h. (2002) t h e radiated seismic energy and apparent stress of interplate and intraslab earthquakes at subduction-zone environments: implications for seismic hazard estimation. in: kirby s., wang k. e dunlop s. (a cura di), the cascadia subduction zone and related subduction systems seismic structure, intraslab earthquakes and processes, and earthquake hazards, u.s. geological survey open-file report 02–328. 320p. cinti f.r., moro m., pantosti d., cucci l. & d’addezio g. (2002) new constraints on the seismic history of the castrovil lari fault in the poll ino gap (calabria, southern italy). j. seismol., 6, 199-217. cotroneo r. (1906) in calabria. in giro su le rovine del terremoto. pp. 88. napoli. covelli g. (1918) la madonna di crotone. crotone. cucci l. e tertulliani a. (2006) i terrazzi marini nell’area di capo vaticano (arco calabro): solo un record di sollevamento regionale o anche di deformazione cosismica? il quaternario, 19, 89-101. de medici m. (a cura di) (1989) martirano lombardo – storia di una città nuova. pp. 159. roma. diss working group (2006) database of individual seismogenic sources (diss), version 3.0.2: a compilation of potential sources for earthquakes larger than m 5.5 in italy and surrounding areas. http://www.ingv.it/diss/. do g l i o n i c., ha r a b a g l i a p., me r l i n i s., mo n e l l i f . , peccerillo a., piromallo c. (1999) orogens and slab vs. their direction of subduction. earthscience reviews, 45, 167-208. du d a s.j. (1965) secular seismic energy release in the circum-pacific belt. tectonophysics, 2, 409452. dumas b. & raffy j. (2004) late pleistocene tectonic activity deduced from uplifted marine terraces in calabria, facing the strait of messina. quaternaria nova, 8, 79-100. dumas b., gueremy p. e raffy j. (2005) evidence for sea-level oscillations by the ‘‘characteristic thickness’’ of marine deposits from raised terraces of southern calabria (italy). quat. sci. rev., 2 4, 2120–2136. du n b a r p.k., lo c k r i d g e p.a. e wh i t e w i d e l.s. (1992) catalog of significant earthquakes 2150 b.c. to the present. ngdc report se-49. ems (1998) european macroseismic scale 1998. editor g. grünthal, cahiers du centre eorpéen de géodynamique et de séismologie, vol. 15. luxembourg. fabbri a., ghisetti f., vezzani l. (1980) the peloritancalabria range and the gioia basin in the calabrian arc (southern italy): relationship between land and marine data. geologica romana, 1 9, 131-150. frepoli a., selvaggi g., chiarabba c. & amato a. (1996) state of stress in the southern tyrrhenian subduction zone from fault-plane solutions. geophys. j. int., 125, 879-891. ga l l i p. (2000) new empirical relationships between magnitude and distance for l iquefaction . tectonophysics, 324, 169-187. ga l l i p. e bo s i v. (2002) paleoseismology along the cittanova fault. implications for seismotectonics and earthquake recurrence in calabria (southern i t a l y ). j. of geophys. res., 1 0 7, b3, 10.1029/ 2001jb000234. galli p. e bosi v. (2003) the catastrophic 1638 earthquakes in calabria (southern italy). new insight from paleoseismological investigation. j. of geophys. res., 108, b1 10.1029/2002jb01713. galli p. e molin d. (2007) il terremoto del 1905 della 231il terremoto del 1905 in calabria: revisione della distribuzione ... calabria meridionale. studio analitico degli effetti ed ipotesi sismogenetiche. gruppo editoriale l’espresso, http://ilmiolibro.kataweb.it/libro. asp?id=14201, 106 pp. galli p. e naso g. (2008) the “taranta” effect of the 1743 earthquake in salento (apulia, southern italy). boll. geof. teor. appl., 49, 177-204. galli p. e scionti v. (2006) two unknown m>6 historical earthquakes revealed by paleoseismological and archival researches in eastern calabria (southern italy). seismotectonic implication. terra nova, 1 8(1), 44-49, 10.1111/j.1365-3121.2005. 00658.x. ga l l i p., mo l i n d., ca m a s s i r., ca s t e l l i v. (2001) i l terremoto del 9 settembre 1998 nel quadro della sismicita’ storica del confine calabro-lucano. possibi li impl icazioni sismotettoniche. i l quaternario, italian j. of quaternary sciences, 14, 31-40. ga l l i p., to l o n e a. e sc i o n t i v. (2005) tre secoli di eventi sismici a crotone. i danni agli edifici nelle fonti storiche dal 1605 al 1905. progetto urban2 crotone. dip. della protezione civile – u. servizio sismico nazionale, pp. 93. roma. ga l l i p., ru g a a., sc i o n t i v., sp a d e a r. (2006a) archaeoseismic evidence for a late roman earthquake in the crotone area (ionian calabria, southern italy): seismotectonic implication. j. of seismology, 10, 443-458. ga l l i p., pi s c i t e l l i s., il a r d o i., sa l u s t r i ga l l i c . , sc i o n t i v., sp i n a v. (2006b) individuazione e caratterizzazione con metodi geoelettrici e paleosismologici della dislocazione attiva nel comune di ciro’ marina. prima campagna. d p c u f f i c i o servizio sismico nazionale, pp. 51. roma. galli p., spina v., ilardo i., naso (2009) evidence of active tectonics in southern italy: the rossano fault (northern calabria). in p. guarnieri (ed.): recent progress on earthquake geology, nova publisher, in press. galli p., scionti v., spina v. (2007) new paleoseismic data from the lakes and serre faults (calabria, southern italy). seismotectonic implication, boll. soc. geol. it., 126, 347-364. galli p., galadini f., pantosti d. (2008) twenty years of paleoseismology in italy . e a r t h s c i e n c e reviews. 88, 89-117. gh i s e t t i f. (1981) evoluzione neotettonica dei principali sistemi di faglie della calabria centrale. boll. soc. geol. it., 99, 387-430. gr u p p o d i la v o r o cpti (1999) catalogo parametrico dei terremoti italiani. ing, gndt, sga, ssn, pp. 99. bologna. gr u p p o d i la v o r o cpti (2004) catalogo parametrico dei terremoti italiani versione 2004. ingv. bologna. http://emidius.mi.ingv.it/cpti/. gr u p p o d i la v o r o cpti (2008) catalogo parametrico dei terremoti italiani versione 2008 (1901-2006). ingv. bologna. http://emidius.mi.ingv.it/cpti08/. gu (1906) elenco dei comuni danneggiati dai terremoti del settembre 1905, ai quali si sono applicate le disposizioni del regio decreto 22 settembre 1905, n. 506. legge 25 giugno 1906, n. 255, relativa ai provvedimenti in favore della calabria. gazzetta ufficiale del regno d’italia, 1 4 9, del 27 giugno 1906, allegati n. 2, n. 4 e n. 5. gu (1906a) consolidamento di frane minaccianti abitat i legge 25 giugno 1906, n) 255, relativa ai provvedimenti a favore della calabria, gazzetta ufficiale del regno d’italia, 1 4 9, del 27 giugno 1906, allegato n) 6 tab) g. gu (1906b) regio decreto che estende ad alcuni comuni della provincia di messina i provvedimenti presi a favore della calabria. gazzetta ufficiale del regno d’italia, n. 185 del 28 agosto 1906. gu e g u e n e., do g l i o n i c., fe r n a n d e z m. (1997) lithospheric boudinage in the western mediterranean back-arc basins. terra nova, 9, 184187. guerra i. e savaglio a. (a cura di) (2006) 8 settembre 1905 – terremoto in calabria. regione calabria – ass. alla cultura, università della calabria – dip. di fisica, deputazione di storia patria per la calabria, pp. 337. castrovillari. ia n n a c o n e g., sc a r c e l l a g. e sc a r p a r. (1985) terremoti intermedi e profondi del mar tirreno. rilocalizzazione con il metodo jhd e meccanismi focali. atti del 4° convegno gngts, 145-157. iglesias a., singh s.k., pacheco j.f. e ordaz m. (2002) a source and wave propagation study of the copalillo, mexico, earthquake of 21 july 2000 (mw 5.9). implications for seismic hazard in mexico city from inslab earthquakes. bull. of the seism. soc. of am., 92, 1061-1072. immagini dal terremoto 1905-2005 (2005) nota introduttiva di giuseppe luongo, pp. 56. castrovillari. ingv (2003-2004) terremoti recenti in italia negli anni 2003 e 2004. www.ingv.it. istat (1902) censimento della popolazione del regno d’italia al 10 febbraio 1901. ministero di agricoltura, industria e commercio, direzione generale della statistica, vol. 1, pp. 455. roma. istat (1985) popolazione residente e presente dei comuni – censimenti dal 1861 al 1981. i s t i t u t o centrale di statistica. roma. ja r i c c i l. (1905) tra rovine e desolazioni. episodi completi del terremoto di calabria 1905. napoli. ka n a m o r i h. (1971) seismological evidence for a li thospheric normal fault ing. the sanriku earthquake of 1933. phys. earth planet interiors, 4, 289-300. kàrnìk v. (1969) seismicity of the european area. part. 1, pp. 364. dordrecht. ki r b y s. (2001) earthquake hazards appraisal for inslab earthquakes in cascadia and latin america: challenges and prospects. seism. res. lett. 7 2, 237. ki r b y s.h e wa n g k. (2002) introduction to a global systems approach to cascadia slab processes and associated earthquake hazards. in: kirby s., wang k. and dunlop s. (eds.), the cascadia subduction zone and related subduction systems. seismic structure, intraslab earthquakes and processes, and earthquake hazards. u.s. geological survey open-file report 02–328, geological survey of canada open file 4350, 182 pp. ko s t n e r f. (2002) la tragedia di aiello. pp. 133. castrovillari. lu c i f e r o a: (1906) del terremoto di calabria degli 8 232 p. galli & d. molin settembre 1905 e dei terremoti in generale, narrazioni e considerazioni. pp. 106. crotone. ly n n e s c.s. e la y t. (1988) source process of the great 1977 sumba earthquake. j. geophys. res., 93, 13407-13420. malagodi o. (1905) calabria desolata. cosenza (2005. malinverno a. e ryan w.b.f. (1986) extension in the tyrrhenian sea and shortening in the apennines as results of arc migration driver by sinking of the lithoshere. tectonics, 5, 227-245. ma r g o t t i n i c., am b r a s e y s n.n. e sc r e p a n t i a. (1993) la magnitudo dei terremoti italiani del xx secolo. enea, pp. 57. roma. martinelli g. (1909) notizie sui terremoti osservati in italia durante l’anno 1906. r. uff. centr. meteor. e geod., suppl. al boll. soc. sism. it., 13. martinelli g. (1910) notizie sui terremoti osservati in italia durante l’anno 1907. r. uff. centr. meteor. e geod. di roma, suppl. al boll. soc. sism. it., 14. martini m. e scarpa r. (1983) earthquakes in italy in the last century. in earthquakes: observation, theory and interpretation, h. kanamori and e. boschi (edts.), scuola italiana di fisica “e. fermi”, 85t h course, pp. 479-492, bologna. mayda b. (1918) splendore della misericordia di maria ss. di capocolonna ossia i miracoli. valle di pompei. mcs (1930) scala macrosismica mercalli-cancanis i e b e r g. in sieberg (1930), geologie der erdbeben, handboch der geophysik, 2, 4, 552554 (tabb. 102 e 103). me r c a l l i g. (1902) sulle modificazioni proposte alla scala sismica de rossi-forel. boll. soc. sism. it., 8, 184-191. mercalli g. (1906) alcuni risultati ottenuti dallo studio del terremoto calabrese dell’8 settembre 1905. atti acc. pontaniana, 36 (1906), 1-9. napoli. mercalli g. (1910) i danni prodotti dai terremoti nella basilicata e nelle calabrie. estratto dalla relazione della sotto giunta parlamentare d’inchiesta sulle condizioni dei contadini nelle provincie meridionali e nella sicilia, 5(3), basilicata e calabria, pp. 17. roma. michelini a., lomax a., nardi a. e rossi a. (2006) la localizzazione del terremoto della calabria dell’8 settembre 1905 da dati strumentali. in guerra e savaglio (2006), 225-240 mi c h e t t i a., fe r r e l i l., se r v a l. & vi t t o r i e. (19 9 7 . geological evidence for strong historical earthquake in an aseismic region: the pollino case (southern italy). j. geodynamics, 24, 67-86. mi y a u c h i t., da i pr a g. e sy l o s la b i n i s. (1994) geochronology of pleistocene marine terraces and regional tectonics in the tyrrhenian coast of south calabria, italy. il quaternario, 7, 17-34. monachesi, g. and stucchi m. (a cura di) (1997) dom 4.1 an intensity database of damaging earthquakes in the italian area. http://emidius.itim.mi.cnr.it/dom/home.html. monaco c. e tortorici l. (1995) tettonica estensionale quaternaria nell’arco calabro e in sicilia orientale. studi geol. camerti (vol. spec.), 2, 351-362. monti v. (1907) notizie sui terremoti osservati in italia durante l’anno 1905. r. uff. centr. meteor. e geod. di roma, pp. 658, supplemento al boll. soc: sism. it., 12, pp. 471. moretti a. e guerra i. (1997) tettonica dal messiniano ad oggi in calabria: implicazioni sulla geodinamica del sistema tirreno-arco calabro. boll. soc. geol. it., 116, 125-142. mu c c i a r e l l i m., be t t i n a l i f., za n i n e t t i a., va n i n i m . , me n d e z a. a n d ga l l i p. (1996) r e f i n i n g nakamura’s technique: processing techniques and innovative instrumentation. seismology in europe, proceedings of the xxv general assembly of the european seismological commission (esc), reykjavik 9-14 september 1996: 411-416. nakamura y. (1989) a method for dynamic characteristic estimation of subsurface using micreotremor on the round surface. qr of rtri, 30, 25-33. nava c. (1907) come risorsero i paesi della calabria. la lettura, a. 7, n. 12 (1907), 992-998. ne r i g., ba r b e r i g., ol i v a g., or e c c h i o b. (2004) tectonic stress and seismogenic faulting in the area of the 1908 messina earthquake, south italy. geophysical research letters, 3 1 , doi:10.1029/2004gl019742. pa t a c c a e., sa r t o r i r. & sc a n d o n e p. (1990) tyrrhenian basin and apenninic arcs: kinematic relations since late tortonian times. m e m o r i e della società geologica italiana, 45, 425–451. pe t e r s c h m i t t e. (1956) quelques donnees nouvelles sur les seismes profonds de la mer tyrrhenienne. annali di geofisica, 9, 305-334. pi a t a n e s i a. e ti n t i s. (2002) numerical modelling of the september 8, 1905 calabrian (southern italy) tsunami. geophys. j. int., 150, 271–284. piromallo c. e morelli a. (2003) p wave tomography of the mantle under the alpine-mediterranean a r e a. j. geophys. res., 1 0 8, b2, 2065, doi: 10.1029/2002jb001757. platania g. (1907) i fenomeni in mare durante il terremoto di calabria del 1905. boll. soc. sism. it., 12 (1907), 43-81. pl a t a n i a g. (1908a) il maremoto dello stretto di messina del 28 dicembre 1908. boll. soc. sism. it., 13, 369-458. platania g. (1908b) il terremoto calabrese dell’8 settembre 1905 a stromboli. mem. cl. sc. r. acc. zelanti, 5 (1905-1906), s. 2a, 79-87. po n t e v i v o a. e pa n z a g. (2006) the lithosphereasthenosphere system in the calabrian arc and surrounding seas southern italy. pure appl. geophys., 163, 1617-1659. postpischl d. (1985) (ed.), atlas of isoseismal maps of italian earthquakes. quaderni de “la ricerca scientifica”, 114, 2a, 164 pp. pugliese f. (1996) il terremoto dell’8 settembre 1905 in calabria – immagini e cronache della stampa dell’epoca. presentazioni di saverio di bella e wladimiro settimelli, pp. 223. firenze. pu l l i n i a., ra v à r. e si m o n e l l i r. (1906) il terremoto nelle calabrie del 1905. giornale del genio civile, a. 44, ottobre 1906, n. 44, 521-546. roma. quintanar l., madariaga r., deschamps a. (1995) the earthquake sequenze of november 1987 and march 1988 in the gulf of alaska: a new insight. geophys. res. lett., 22, 1028-1032. re d. (2006) s. martino di finita tra scosse e frane … un paese da spostare. in guerra e savaglio 233il terremoto del 1905 in calabria: revisione della distribuzione ... (2006), 141-154. ri u s c e t t i m. e sh i c k r. (1975) earthquakes and tectonics in southern italy. boll. geof. teor. appl., 17, 59-78. ri z z o g.b. (1906a) sopra il calcolo della profondità degli ipocentri nei movimenti sismici. atti regia accademia delle scienze di torino, 6, 1061-1066. rizzo g.b. (1907) contributo allo studio del terremoto della calabria del giorno 8 settembre 1905. atti r. acc. peloritana, 22, 3-86. rsc (1905. in calabria, in giro su le rovine del terremoto. rivista storica calabrese, 13 (1905, s. 4a, parte 4a.. reggio calabria. sa n g i n e t o a.b. (1989) scavi nell’abitato romano di vibo valentia. ann. sc. norm. sup. pisa, s.iii, xix, 2, 833-843. sa r c o n i, m. (1784) istoria de’ fenomeni del tremoto avvenuto nelle calabrie, e nel valdemone nell’anno 1783 posta in luce dalla reale accademia delle scienze, e delle belle lettere di napoli. napoli. savaglio a. (2006) la gestione della prima emergenza e le vittime della catastrofe. in guerra e savaglio (2006), 57-82. sc h i a t t a r e l l a m. (1998) quaternary tectonics of the pol lino ridge, calabria-lucania boundary, southern italy. spec. publ., geological society, london 135, 341-354. sc i o n t i v., ga l l i p. (2005) nuovi dati sulla sismicità della calabria nei secoli del viceregno. rogerius boll. ist. bibl. cal., 8(2), 65-84. sc i o n t i, v., ga l l i, p. a n d ch i o d o, g. (2006) t h e calabrian seismicity during the viceroyalty of naples: sources silence or silent sources? the case of the strong 1744 earthquake. boll. geof. teor. e appl., 47, 53-72. se n o t., ya m a n a k a y. (1998) double seismic zones, deep compressional trench—outer rise events and s u p e r p l u m e s. in: bebout, g.e., scholl, d.w., kirby, s.h., platt, j.p. (eds.). subduction top to bottom, vol. 96. agu, washington, dc, geophys. monogr., 347–355. si n g h s.k., or d a z m., al c a n t a r a l., sh a p i r o n . m . , ko s t o g l o d o v v., pa c h e c o j.f., al c o c e r s . , gu t i e r r e z c., qu a a s r., mi k u m o t., ov a n d o e . (2000) the oaxaca earthquake of 30 september 1999 (mw=7.5) a normal faulting event in the subducted cocos plate. seism. res. lett., 71, 67-78. taramelli t. (1909) dei terremoti di calabria e sicilia. pavia. estratto da riv. di fis. mat. e sc. nat., 10(n. 109). tortorici g., bianca m., monaco m., tortorici l., tansi c., de guidi g. e catalano s. (2002) quaternary normal faulting and marine terracing in the area of capo vaticano and s. eufemia plain (southern calabria, italy). studi geologici camerti, 2, 1-16. tortorici l. (1982) lineamenti geologico strutturali dell’arco calabro-peloritano. soc. it. min. petr., 38, 927-940. tortorici l., monaco c., tansi c. e cocina o. (1995) recent and active tectonics in the calabrian arc (southern italy). tectonophysics, 243, 37-55. tr i p o d i v. (1945) breve monografia su s. eufemia d’aspromonte. sant’eufemia d’aspromonte. van dijk, j. & okkes m. (1991) neogene tectonostratigraphy and kinematics of calabrian basins; implications for the geodynamics of the central mediterranean. tectonophysics 196, 23-60. vannucci g. e gasperini p. (2004) the new release of the database of earthquake mechanisms of the mediterranean area (emma version 2). ann. geophys., suppl. vol. 47 (1), 307-334. vulcano a. e mazza f. (2006) tecniche costruttive in uso agli inizi del ‘900 in calabria e loro influenza sugli effetti del terremoto. in guerra e savaglio (2006), 241-253. 234 ms. ricevuto il 24 febbraio 2009 testo definitivo ricevuto il 10 luglio 2009 ms. received: february 24, 2009 final text received: july 10, 2009 p. galli & d. molin 08fornoetal contributo presentato al convegno aiqua-apat: il quaternario nella cartografia carg, roma, 21-22 febbraio 2008. la rappresentazione cartografica della successione continentale pliocenico-quaternaria delle aree collinari piemontesi nel progetto carg maria gabriella forno1, gianfranco fioraso2 & paola boano3 1dipartimento di scienze della terra, università di torino, e-mail gabriella.forno@unito.it 2c.n.r. istituto di geoscienze e georisorse, unità operativa di torino 3libero professionista, via asti 13, tonco (at) riassunto: forno m. g., fioraso g. & boano p., la rappresentazione cartografica della successione continentale pliocenico-quaternaria delle aree collinari piemontesi nel progetto carg. (it issn 0394-3356, 2009). precedentemente all'avvio del progetto carg, la rappresentazione dei sedimenti continentali plio-quaternari nelle aree collinari piemontesi è stata per lo più trascurata in relazione alle difficoltà insite nell'individuazione e nell’interpretazione dei depositi, che risultano conservati per lo più in lembi relitti discontinui e di esiguo spessore. a ostacolare ulteriormente la cartografia e l’interpretazione delle successioni si aggiungono la scarsità di affioramenti significativi, l’espressione morfologica dei sedimenti, spesso di difficile lettura, e la diffusione delle discontinuità erosionali, che hanno suggerito il ricorso alle unità a limiti inconformi (unconformity bounded stratigraphic units; ubsu). notevoli difficoltà di rappresentazione sono infine causate dalla diffusione dei prodotti colluviali derivanti dalla rielaborazione dei diversi termini della successione, dall’estensione degli accumuli di frana e dalla convergenza di facies che mostrano alcuni termini quaternari sia rispetto ai sottostanti sedimenti marini, sia nei confronti dei sovrastanti prodotti colluviali. in occasione della realizzazione dei fogli "trino" e "torino est" del progetto carg, per la cartografia della successione continentale quaternaria sono state utilizzate le unità a limiti inconformi: la presenza di diversi corpi sedimentari sovrapposti, separati da evidenti discontinuità erosionali, e la necessità di distinguere i depositi provenienti dai rispettivi bacini di alimentazione hanno imposto l'introduzione di legende piuttosto articolate, a scapito di una più immediata lettura dei documenti cartografici. particolarmente complessa è risultata la rappresentazione cartografica nelle aree in cui sono presenti diverse unità sedimentarie affioranti in uno spazio ristretto, separate da importanti discontinuità erosionali. nonostante le difficoltà interpretative, va tuttavia segnalata l’importanza che i depositi continentali rivestono nella ricostruzione della storia geologica recente: la sensibile deformazione dei rilievi è infatti suggerita dall'anomala distribuzione altimetrica di questi sedimenti, indotta dall’evoluzione pliocenico-quaternaria di importanti strutture tettoniche preesistenti o di neoformazione e dal sollevamento differenziale che ha interessato le differenti aree collinari. un aspetto spesso non risolto è invece quello legato alla difficoltà nell’individuazione di elementi cronologici di riferimento, che nelle aree collinari piemontesi è in genere basata esclusivamente su criteri pedostratigrafici: l’unica eccezione è costituita dai sedimenti deltizi "villafranchiani", riccamente fossiliferi, per i quali si è potuta proporre una più precisa attribuzione cronologica. abstract: forno m. g., fioraso g. & boano p., cartography of the plio-quaternary continental succession of piedmont hilly area in the carg project. (it issn 0394-3356, 2009). before the carg project, the plio-quaternary continental succession of piedmont hilly area was prevalently omitted by a geological map. the continental deposits are, in fact, difficult to identify and to interpret because of their preservation in discontinuous relicts which are slightly thick. in detail, the scarcity of significant outcrops, the ambiguous morphological expression and the numerous erosional discontinuities further handicap the cartography and the interpretation of successions. the diffusion of discontinuities implies the use of unconformity boundary stratigraphic units. the widespread colluvium, connected with the reworking of different terms of succession, and the frequent landslides create further remarkable problems of mapping. the convergence of some quaternary terms with the later marine units or with the recent colluvium, further complicates the cartography. during the mapping of the “trino” and “torino est” sheets of the carg project the unconformity bounded stratigraphic units (ubsu) are used for mapping the quaternary continental succession. the presence of some superimposed sedimentary bodies, separated by evident erosional discontinuities, and the necessary differentiation of various alimentation basins impose to introduce an articulate legend, to the detriment of un immediate understanding of maps. the fluvial succession connected with an ancient trend of the po river (paleopo) is described in the southern slope of the torino hill. the fluvial terraced succession connected to ancient alpine watercourses (paleodora riparia, paleostura di lanzo, paleoorco and paleodora baltea) is instead mapped on the western and northern slopes. both the successions are strongly uplifted. the sediments connected with ancient tributary watercourses are also represented, in both the areas, and distinguished from the current fluvial sediments. the cartography of succession in areas of distribution of different sedimentary units outcropping in a small sector, separated by erosional discontinuities, was particularly complex. a part from the interpretative difficulties, the importance of continental deposits is pointed out in order to reconstruct the recent geological history: the anomalous altimetrical distribution suggests a remarkable deformation of the hilly area, connected with the evolution of important pre-existent or new tectonic structures and with the differential uplift of the different areas. the difficulty in the individuation of chronological elements in the sediments, often only of pedostratigraphic nature, represents an unresolved aspect. the only exception is the fossiliferous villafranchian succession that allows a detailed chronological reference. parole chiave: cartografia geologica, rilievi collinari piemontesi, successione continentale pliocenica-pleistocenica. key words: geological map, piedmont hilly area, plio-quaternary continental succession. il quaternario italian journal of quaternary sciences 22(1), 2009 83-94 84 m.g. forno, g. fioraso & p, boano 1. introduzione nelle aree collinari piemontesi, corrispondenti ai rilievi delle langhe, del monferrato e della collina di torino, precedentemente all'avvio del progetto carg sono stati presi in esame con notevole dettaglio esclusivamente i termini marini che costituiscono il cosiddetto bacino terziario piemontese (btp) (fig. 1); l'analisi e la rappresentazione cartografica dei sedimenti continentali pliocenico-quaternari affioranti negli stessi settori è stata invece per lo più trascurata. lo scarso interesse suscitato dalla successione continentale è da ricercarsi da un lato nella più consolidata tradizione riguardante lo studio delle successioni marine (in parte dovuta anche all'unicità dei termini stratigrafici marini affioranti nell'ambito del btp, alcuni dei quali ben noti anche nella letteratura internazionale), dall'altro a un insieme di difficoltà oggettive insite nell’individuazione e nell’ interpretazione delle unità depostesi in ambienti continentali: queste ultime sono infatti spesso conservate come lembi discontinui per effetto dell'intensa attività di incisione e di rimodellamento avvenuta in ambito collinare. problematici per la correlazione dei corpi geologici e la ricostruzione del quadro stratigrafico pliocenico-quaternario sono inoltre l’esiguo spessore dei depositi, in genere non superiore alla decina di metri, e la ridotta estensione degli affioramenti: l’assenza di sezioni geologiche naturali sufficientemente estese, tali da consentire l’osservazione diretta dei rapporti tra i diversi corpi sedimentari, rappresenta l’inconveniente maggiore, in quanto lascia ampio spazio a diverse possibili interpretazioni e non pone, di conseguenza, precisi vincoli alla ricostruzione stratigrafica. a differenza di quanto in genere osservabile per le successioni marine, quelle di origine continentale sono contraddistinte al loro interno da numerose discontinuità erosionali di diverso significato genetico e rango gerarchico le quali, se non correttamente individuate, interpretate e cartografate, possono condurre a una ricostruzione stratigrafica errata: l’esempio più significativo per l’area collinare piemontese riguarda il cosiddetto “villafranchiano” auct., costituito da due distinti complessi sedimentari tra loro sovrapposti (cfr. § 2) (carraro ed., 1996) ma, ancora di recente, erroneamente indicato in letteratura come corrispondente a un’unica unità a valenza cronostratigrafica. inoltre, con la sola esclusione di alcune litofacies particolarmente significative quali il loess eolico, i sedimenti continentali derivano spesso dalla rielaborazione dei sottostanti termini marini, rispetto ai quali possono pertanto mostrare una spiccata "convergenza di facies". particolarmente complesso, e spesso non risolvibile, appare infine il problema relativo alla datazione dei depositi continentali, per i quali, in assenza di un adeguato contenuto fossilifero o di altri marker significativi, solo raramente è possibile definire un preciso inquadramento cronologico. a favorire una corretta analisi e interpretazione dei diversi termini pliocenico-quaternari può intervenire l'espressione morfologica, che in genere caratterizza i sedimenti continentali: sebbene variamente rimodellata, l'espressione superficiale spesso presenta elementi del tutto caratteristici dell'ambiente di sedimentazione, facilitando pertanto la ricostruzione e la rappresentazione delle originarie geometrie deposizionali. nel prosieguo della presente nota vengono evidenziate le ragioni che hanno privilegiato l'uso delle unità a limiti inconformi ("unconformity bounded stratigraphic units"; ubsu) nella rappresentazione delle successioni continentali quaternarie piemontesi. sono inoltre illustrati alcuni esempi cartografici relativi all’area collinare compresa nei fogli 156 “torino est” e 157 fig. 1 schema geologico del bacino terziario piemontese. al: catena alpina. ap: catena appenninica. fl: falde liguri. bacini sedimentari paleogenico-neogenici su substrato alpino: ct = collina di torino; lg = langhe. bacini sedimentari paleogenico-neogenici su substrato appenninico: mn = monferrato. m: successione messiniana. pq: successione pliocenico-quaternaria. li: linea insubrica. i riquadri rappresentano le aree dei fogli 156 "torino est" e 157 "trino" della carta geologica d'italia alla scala 1:50.000. geological sketch of the tertiary piedmont basin. al: alpine thrust belt. ap: apennines thrust belt. fl: ligurian nappes. alps-related paleogenic to neogenic sedimentary basins: ct = torino hill; lg = langhe. apennines-related paleogenic to neogenic sedimentary basins: mn = monferrato. m: messinian succession. pq: pliocenic to quaternary sediments. li: insubric line. squares correspond to 156 "torino est" and 157 "trino" sheets of the geologic map of italy at 1:50.000 scale. “trino” della carta geologica d'italia alla scala 1:50.000 (dela pierre et al., 2003; festa et al., in stampa): vengono in particolare evidenziate le caratteristiche delle unità affioranti (fig. 2), le problematiche incontrate nel corso dei rilievi di terreno e le soluzioni adottate per la stesura dei documenti cartografici. 2. la successione "villafranchiana" i l più antico termine di natura continentale affiorante nell'ambito dei rilievi collinari piemontesi corrisponde alla successione "villafranchiana", ampiamente descritta e analizzata da numerosi autori in relazione soprattutto al ricco contenuto fossilifero (cuvier, 1806a, b; borson, 1830a, b; sismonda, 1849, 1852; gastaldi, 1860, 1861; de mortillet, 1864; pareto, 1865; sacco, 1895). nel corso degli ultimi anni, accurati rilievi geologici hanno condotto alla completa revisione di questa potente successione, costituita da sedimenti deltizi e fluviali, consentendo fra l'altro di riconoscere al suo interno la presenza di un’importante discontinuità erosionale estesa su scala regionale e indicata come superficie di cascina viarengo (carraro ed., 1996; boano & forno, 1996, 1999; boano et al., 1997) (fig. 3): essa corrisponde a una discordanza angolare che separa due corpi sedimentari sovrapposti, i l complesso inferiore e i l complesso superiore, contraddistinti da diversi caratteri sedimentari e da un differente grado di deformazione tettonica. il reale signif icato di questa discontinuità, difficilmente individuabile e interpretabile alla scala del singolo affioramento, è emerso essenzialmente grazie al rilievo geologico effettuato sull’intera area-tipo e a un'accurata rappresentazione cartografica, che hanno consentito di evidenziare come essa separi due corpi geologici con giacitura leggermente differente. il complesso inferiore è rappresentato alla base dalle sabbie di ferrere (fig. 4), caratterizzate da una stratificazione incrociata concava, con immersioni in senso opposto, contenenti localmente frammenti di 85la rappresentazione cartografica della ... fig. 2 schema geologico dell'area di indagine. 1: successione pre-pliocenica. 2: successione pliocenica. 3: sedimenti fluviali terrazzati (pleistocene medio-superiore). 4: sedimenti fluviali recenti e attuali (pleistocene superiore attuale). 5: principali strutture anticlinali. 6: thrust frontale padano. 7: scarpata di erosione. zdrf: zona di deformazione di rio freddo. geological sketch of the studied area. 1: pre-pliocene succession. 2: pliocene succession. 3: terraced fluvial sediments (middle-upper pleistocene). 4: fluvial sediments (late upper pleistocene-present). 5: main anticline structures. 6: padanian thrust front. 7: erosional scarp. zdrf: rio freddo deformation zone. fig. 3 discontinuità erosionale di cascina viarengo, corrispondente ad una discordanza angolare che separa i due complessi costituenti la successione "villafranchiana" (cascina san martino, villafranca d’asti, fronte di cava con altezza di 13 m). cascina viarengo erosional surface, corresponding to an angular unconformity between the upper and lower "villafranchian" complexes (cascina san martino, villafranca d’asti, quarry front 13 m high). molluschi marini, di macroresti vegetali e di vertebrati continentali. la natura sabbiosa, le strutture sedimentarie e la mescolanza di fossili marini e continentali sono indicativi di una facies di fronte deltizio. sovrapposti alle sabbie di ferrere si sviluppano i silt di san martino costituiti da alternanze di sedimenti siltosi e sabbiosi: i primi, ricchi di macroresti vegetali, costituiscono il colmamento dei settori di intercanale di una pianura deltizia (fig. 5); i sedimenti sabbiosi rappresentano invece il riempimento dei canali distributori della pianura deltizia, entro i quali sono state rinvenute numerose carcasse, talvolta complete, di vertebrati fluitati (fig. 6). il complesso inferiore, riferibile ad un ambiente deltizio, poggia in continuità di sedimentazione sulle sabbie di asti, deposte invece in ambiente litorale. i sedimenti che lo compongono sono riccamente fossiliferi, contenendo resti di vertebrati tra cui si ricordano mastodon arvernensis, stephanorhinus jeanvireti, mesopithecus monspessolanus, leptobos stenometopon e tapirus arvernensis, che consentono un riferimento al pliocene medio (campanino et al., 1994). questi rinvenimenti, associati ad un ricco contenuto micropaleontologico, consentono un'attribuzione del complesso inferiore al pliocene medio. il complesso è inoltre caratterizzato da una apprezzabile deformazione tettonica, responsabile dell’inclinazione dei sedimenti di circa 10° verso ovest. relativamente differenti sono invece le caratteristiche del complesso superiore: esso è costituito alla base dal sintema di morialdo, formato da sabbie e ghiaie minute riferibili ad un ambiente fluviale ad elevata energia; al tetto si sviluppa invece il sintema di buttigliera, formato in netta prevalenza da silt argillosi connessi allo sviluppo di un'ampia pianura di esondazione fluviale. i l complesso superiore mostra un contenuto fossilifero scarso e poco significativo che ne ha consentito una attribuzione, per quanto dubitativa, al pleistocene inferiore ed è interessato da una modestissima deformazione, evidenziata dalla giacitura suborizzontale dei sedimenti. proprio il differente significato paleoambientale e cronologico attribuito ai due complessi sedimentari, nonché la presenza di un diverso assetto giaciturale dei sedimenti deltizi e fluviali, suggeriscono l’interposizione di una significativa lacuna stratigrafica che materializza uno iatus temporale esteso a coprire parte del pliocene 86 fig. 4 stratificazione incrociata concava delle sabbie di ferrere, riferibili ad un ambiente di fronte deltizio (castelnuovo don bosco, fronte di cava con altezza di circa 15 m). well-developed trough cross-bedding in the ferrere sands, referred to a deltaic front environment (castelnuovo don bosco, quarry front about 15 m high). fig. 5 macroresti vegetali nei silt di san martino, riferibili ad un ambiente di pianura deltizia (cascina san martino, villafranca d’asti). plant remains in the san martino silts, referred to a deltaic plain environment (cascina san martino, villafranca d’asti). m.g. forno, g. fioraso & p, boano medio, il pliocene superiore e parte del pleistocene inferiore: lo sviluppo di questa discordanza è imputabile alla deformazione tardo-pliocenica subita dall'edificio collinare in risposta alla strutturazione del thrust frontale padano (carraro ed., 1996; boano & forno, 1996, 1999; boano et al., 1997; mosca, 2006). per la rappresentazione della successione "villafranchiana" affiorante nei fogli "torino est" e "trino", le di faglia di castelnuovo don bosco e dalla zona di faglia di cascina fagliaverde, entrambe corrispondenti a strutture en échelon a sviluppo subverticale e con direzione media n120°. sono anche state individuate alcune discontinuità con andamento circa n-s indicate come faglia di serra, faglia di capriglio e faglia di agagliate. in stretta relazione alle strutture regionali si osservano strutture minori, corrispondenti a soft sediments deformations, che interessano i sedimenti “villafranchiani” del complesso inferiore: in questi casi spesso si rinvengono, associati, diversi tipi di deformazioni quali slumpings, lamine destrutturate, fratture a varia scala, strutture da carico e filoni sedimentari (fig. 8) (boano et al., 1997). localmente sono stati evidenziati anche corpi sedimentari di ridotta estensione ma che, per le loro caratteristiche intrinseche, particolari caratteristiche stratigrafiche del complesso inferiore (graduale passaggio ai sottostanti termini marini) e di quello superiore (presenza di discontinuità significative a tetto e a letto del corpo sedimentario) hanno inevitabilmente imposto l'utilizzo di un criterio di classificazione stratigrafica ibrido, in accordo con quanto suggerito dalle linee guida del progetto carg (pasquaré et al., 1992; germani et al., 2003): per le sabbie di ferrere e i silt di san martino si è fatto ricorso a criteri prettamente litostratigrafici; per i sovrastanti sintemi di morialdo e di buttigliera si sono utilizzate le unità a limiti inconformi. il notevole dettaglio introdotto nel corso del rilevamento ha inoltre consentito di evidenziare la presenza di alcune importanti discontinuità strutturali, in genere non percepibili alla scala dell'affioramento, che dislocano le sabbie di asti e la sovrastante successione “villafranchiana”, con rigetti complessivi valutabili in alcune decine di metri (fig. 7) (boano & forno, 1999; festa et al., in stampa). le principali discontinuità tettoniche evidenziate sono rappresentate dalla zona 87 fig. 6 sabbie costituenti il riempimento di un canale fluviale entro i silt di san martino, contenenti un frammento di stephanorhinus jeanvireti (cascina melona, roatto). sands filling a fluvial channel in the san martino silts, with stephanorhinus jeanvireti rests (cascina melona, roatto). fig. 7 la zona di faglia di castelnuovo don bosco che disloca la successione "villafranchiana".1: sabbie di asti. 2: silt di san martino (“villafranchiano” auct.). 3: sabbie di ferrere (“villafranchiano” auct.). 4: sintema di morialdo. 5: sintema di buttigliera. 6: sintema di san giovanni. 7: sintema di palazzolo. 8: depositi di frana. castelnuovo don bosco fault zone responsible of the dislocation of the "villafranchian" succession.1: asti sands. 2: san martino silts (“villafranchiano” auct.). 3: ferrere sands (“villafranchiano” auct.). 4: morialdo synthem. 5: buttigliera synthem. 6: san giovanni synthem. 7: palazzolo synthem. 8: landslide deposits. la rappresentazione cartografica della ... 88 rivestono un importante significato geologico. l’esempio più significativo è rappresentato dalle facies “villafranchiane” rielaborate da fenomeni gravitativi sinsedimentari: la scelta di cartografare questi corpi, difficilmente rappresentabili in una cartografia a piccola scala come quella adottata nel progetto carg, è motivata dal fatto che essi attestano la presenza, nell'originario contesto deposizionale, di scarpate di faglia in grado di interagire attivamente con la sedimentazione deltizia (boano et al., 1997) (fig. 7). in tal senso, è da sottolineare come l’ambiente di pianura deltizia, caratterizzato da gradienti estremamente modesti e quindi generalmente non soggetto a fenomeni gravitativi, si presti in modo particolarmente efficace per evidenziare la presenza di fenomeni tettonici sinsedimentari. allo stesso modo, per l’importante significato che essi rivestono nell’evoluzione geologica, sono stati rappresentati alcuni lembi di suoli molto evoluti sviluppati al tetto delle sabbie di asti, indicativi di aree relativamente stabili scarsamente interessate dall’erosione (boano et al., 1999). 3. la successione fluviale pleistocenica l’avvio del progetto carg ha rappresentato un’occasione unica per lo studio e l'analisi del quaternario continentale delle aree collinari piemontesi, offrendo la possibilità di effettuare una nuova cartografia di dettaglio delle formazioni superficiali, prevalentemente non raffigurate nella cartografia precedente con la sola eccezione della copertura eolica (bortolami et al., 1969). il progetto ha inoltre consentito di definire la successione stratigrafica relativa a grandi aree e, pertanto, di riconoscere gli areali di distribuzione dei sedimenti pertinenti ai singoli bacini idrografici. questi due elementi hanno permesso di tracciare un quadro evolutivo estremamente particolareggiato, anche in presenza di una significativa mobilità tettonica differenziale come quella che ha caratterizzato i rilievi collinari piemontesi. le recenti indagini riguardanti la successione pleistocenica di queste aree hanno permesso di individuare la presenza di antichi sedimenti fluviali distribuiti su entrambi i versanti della coll ina di torino e del monferrato e in corrispondenza all’altopiano di poirino. sul versante meridionale dei rilievi i sedimenti fluviali, prevalentemente siltosi e solo localmente ghiaiosi, sono riconducibili ad un antico tracciato del f. po che nel corso del pleistocene medio e superiore defluiva a sud dell’edificio collinare (paleocollettore meridionale) e ad alcuni suoi affluenti alpini: la successione è interessata da una significativa deformazione a carattere differenziale, progressivamente maggiore procedendo verso lo spartiacque collinare, dove i sedimenti risultano sospesi con un dislivello fino a circa 300 m rispetto al reticolato idrografico dell'attuale pianura (forno, 1980, 1982; compagnoni & forno, 1992). sui versanti occidentale e nordoccidentale dei rilievi della collina di torino e del monferrato i sedimenti fluviali, anch'essi prevalentemente siltosi con subordinate intercalazioni ghiaiose, pur essendo prospicienti all’attuale alveo del f. po sono stati interpretati come il prodotto del deflusso di corsi d’acqua alpini (paleocollettore settentrionale), in un intervallo di tempo (pleistocene medio e superiore) che precede l’impostazione del f. po nella sua attuale configurazione: l'attribuzione di queste unità a corsi d’acqua di pertinenza alpina è avvalorata dall'analisi mineralogica dei sedimenti (vezzoli et al., 2005). la successione fluviale di questo settore appare sensibilmente terrazzata con lembi di depositi sospesi, con un dislivello fino a circa 400 m, rispetto al reticolato idrografico di pianura: i rapporti di terrazzamento esistenti tra i diversi corpi sedimentari, indicativi di una spiccata attività erosiva dei corsi d’acqua, testimoniano una deformazione quaternaria particolarmente marcata del settore settentrionale dell’area collinare, riconducibile all'evoluzione del thrust frontale padano (forno et al., 2002; boano et al., 2004; forno & lucchesi, 2005; barbero et al., 2007). le tracce del modellamento fluviale pleistocenico riconosciute nelle diverse aree collinari non sono pertanto riferibili all’attuale reticolato idrografico, ma sono da ricondurre al paleoreticolato idrografico regionale. l’impostazione del f. po lungo il margine settentrionale del rilievo e l’assetto dell’attuale idrografia collinare risultano invece estremamente recenti (carraro, 1976; carraro et al., 2005): i sedimenti connessi con il nuovo andamento, oltre ad avere una diversa composizione petrografica dei clasti rispetto ai depositi del paleoretim.g. forno, g. fioraso & p, boano fig. 8 soft sediment deformations, con altezza di circa 15 cm, rinvenute entro i sedimenti "villafranchiani" in prossimità delle discontinuità strutturali individuate (cimitero di valle sauglio, trofarello). about 15 cm high soft sediment deformations in the "villafranchian" succession near the reported structural discontinuities (cimitero di valle sauglio, trofarello). colato, hanno una distribuzione localizzata esclusivamente in prossimità dell’incisione attuale, sviluppata al margine settentrionale del rilievo collinare, e sono riferibili esclusivamente alla parte alta del pleistocene superiore e all’olocene. l'analisi e la rappresentazione cartografica della successione di sedimenti fluviali distribuiti sui versanti collinari ha tuttavia presentato una serie di difficoltà oggettive fra le quali il sensibile grado di antropizzazione di alcune aree, responsabile in taluni casi di radicali modificazioni dell'originario assetto morfologico, e in secondo luogo le difficoltà di accesso alle proprietà, in genere rappresentate da edifici di pregio architettonico compresi in aree residenziali. in merito al primo aspetto, particolare attenzione è stata posta alla valutazione del reale significato degli elementi del paesaggio attuale presenti nelle aree collinari, con specifico riferimento ai lembi di superfici terrazzate su cui molto spesso sorgono edifici antichi. la correlabilità altimetrica e pedostratigrafica tra i diversi lembi e il frequente rinvenimento di depositi ha consentito di verificare la genesi fluviale della maggior parte delle superfici, solo talvolta interessate da modesti ampliamenti. si è invece omessa la rappresentazione dei lembi profondamente modificati dall'intervento antropico come nel caso dell'ampia superficie terrazzata di villa sambuy, localizzata in prossimità del margine settentrionale della collina di torino (san mauro) (festa et al., in stampa). solo in alcune situazioni la presenza di strutture antropiche ha determinato condizioni favorevoli all’osservazione e allo studio dei sedimenti. un esempio in tal senso è fornito dal lembo di terrazzo che ospita villa gualino (forno et al., 2002), localizzato sul versante settentrionale della collina di torino: la realizzazione di una serie di indagini di sottosuolo (sondaggi a carotaggio continuo) ha consentito di rinvenire, al di sotto della coltre antropica e colluviale, un esteso corpo fluviale altrimenti difficilmente individuabile (fig. 9). il corpo, costituito da una successione di sedimenti sabbiosi e siltosi, ha un'estensione laterale di alcune centinaia di metri e uno spessore massimo di circa 5 m: la forma lenticolare del deposito fluviale e la sua chiusura laterale fanno sì che esso non affiori mai, neppure lungo le scarpate che delimitano la superficie terrazzata. in generale, le dimensioni molto ridotte dei lembi quaternari e il modesto spessore dei sedimenti creano notevoli difficoltà sia nel corso dei rilievi di terreno, che devono necessariamente procedere con estremo dettaglio, sia durante la successiva fase interpretativa e di stesura cartografica. la rappresentazione dei sedimenti quaternari, la cui presenza è riconoscibile grazie a pochi ma significativi aff ioramenti, deve pertanto essere integrata anche dall'analisi dei subaffioramenti e dei prodotti colluviali connessi con la rielaborazione dei sedimenti fluviali, che permettono di apprezzare la reale estensione dei diversi corpi geologici. anche per la successione fluviale pleistocenica la rappresentazione cartografica è avvenuta mediante l’utilizzo delle unità a limiti inconformi. tuttavia, le profonde modificazioni subite nel tempo dal reticolato idrografico collinare e la presenza di successioni estremamente frammentate dai fenomeni erosivi, quali quelle presenti nei rilievi collinari piemontesi, hanno portato a introdurre generici "paleocollettori", corrispondenti a raggruppamenti di bacini idrografici alpini tra loro confluenti, completamente svincolati rispetto al reticolato idrografico attuale. nel caso del foglio "torino est", accanto ai bacini del f. po e dei principali affluenti alpini (sangone, dora riparia, stura di lanzo, orco e dora baltea), sono stati introdotti il “paleocollettore meridionale”, a cui sono riferibili lembi di depositi conservati sul versante meridionale della collina di torino, e il “paleocollettore settentrionale”, i cui relitti sono conservati sul versante settentrionale del rilievo (dela pierre et al., 2003; festa et al., in stampa). la maggior parte delle unità fluviali riconosciute in ambito collinare sono state attribuite a questi due corsi d’acqua, i cui sedimenti si differenziano nettamente da quelli legati all’andamento attuale del f. po. al "paleocollettore meridionale" sono stati attribuiti, in particolare, quattro sintemi: i due sintemi più antichi, riferibili al pleistocene inferiore, comprendono il complesso superiore della successione "villafranchiana", di età pleistocenica inferiore, e affiorano solo sporadicamente lungo il margine meridionale della collina di torino e del monferrato; per contro i due sintemi più recenti, riferibili al pleistocene medio e superiore, hanno una distribuzione molto ampia rappresentando i termini quaternari arealmente più diffusi in ambito collinare: costituiscono ampie depressioni relitte con andamento arcuato in pianta attribuibili al modellamento di un grande corso d’acqua a meandri con deflusso verso est 89la rappresentazione cartografica della ... fig. 9 profilo geologico realizzato in corrispondenza del lembo di superficie terrazzata di villa gualino (torino), con l’indicazione del corpo fluviale rinvenuto tramite i sondaggi (da forno et al., 2002). geological cross section along the villa gualino terraced surface, with the fluvial body recognized by boreholes (da forno et al., 2002). modo meno accentuato dal reticolato idrografico. dal punto di vista cartografico, la locale presenza di una estesa copertura di loess, riferibile al pleistocene superiore, e di sabbie eoliche oloceniche ha spesso ostacolato, non solo il riconoscimento dei sottostanti termini fluviali, ma anche la loro rappresentazione cartografica: quest'ultima è risultata particolarmente com(forno, 1980; 1982; carraro et al., 2005). particolarmente evidente è l’espressione morfologica complessiva dei due termini più recenti, corrispondente ai relitti di una estesa pianura alluvionale connessa con un antico andamento del f. po, impostato a sud della collina di torino, e dei relativi affluenti di provenienza alpina. i relitti morfologici dell’originaria pianura alluvionale, che si può ipotizzare avesse una blanda inclinazione verso est, e i sedimenti fluviali che la costituiscono appaiono attualmente variamente deformati. i sedimenti più antichi, compresi nel sintema di zanco riferibile al pleistocene medio (dela pierre et al., 2003; festa et al., in stampa), poggiano su evidenti superfici di erosione modellate nei diversi termini della successione marina terziaria (fig. 10) e sono distribuiti lungo una fascia altimetrica compresa tra 270 e 550 m di quota. essi corrispondono a lembi profondamente incisi dal reticolato idrografico sovraimposto, risultando infatti conservati unicamente sulla sommità delle dorsali collinari: i sedimenti hanno perso l’originaria giacitura suborizzontale e attualmente appaiono caratterizzati da valori medi di inclinazione di circa 7-8° verso sud (fig. 11). il sintema di zanco è costituito in netta prevalenza da sedimenti fluviali siltosi caratterizzati da una notevole alterazione; solo localmente sono presenti corpi lenticolari ghiaiosi (fig 10). la litologia dei clasti che caratterizza questa unità indica inequivocabilmente il contributo di un importante corso d’acqua proveniente dal settore alpino modellato nel massiccio ultrabasico di lanzo (compagnoni & forno, 1992). i sedimenti più recenti, rappresentati dal sintema di san giovanni (di età pleistocenica superiore) (festa et al., in stampa), poggiano su una superficie erosionale modellata nei diversi termini della successione "villafranchiana" e sono conservati con continuità in corrispondenza al settore settentrionale dell’altopiano di poirino. corrispondono a un corpo sedimentario relativamente continuo caratterizzato da un’inclinazione modesta (0,3 %) verso ssw: rispetto al sintema di zanco, i l sintema di san giovanni risulta solo blandamente deformato ed inciso in 90 fig. 10 depositi fluviali ghiaiosi connessi al “paleocollettore meridionale” (sintema di zanco), poggianti su una superficie di erosione modellata nei sedimenti "villafranchiani" (fronte di cava con altezza di circa 6 m). gravelly fluvial deposits connected with the “southern palaeocollector” (zanco synthem), resting above erosional surface modelled in the" villafranchian" sediments (quarry front about 6 m high). fig. 11 espressione morfologica dell’estesa pianura modellata dal “paleocollettore meridionale” (sintema di zanco) nei dintorni di chieri, sul versante meridionale della collina di torino: la linea tratteggiata rappresenta il margine superiore della pianura. morphological evidence of the widespread plan modelled by the “southern palaeocollector” (zanco synthem) near chieri, along the southern slope of the torino hill: the broken line is the edge of the plain. m.g. forno, g. fioraso & p, boano plessa nelle aree in cui sono presenti diverse unità sedimentarie affioranti in uno spazio ristretto (fig 12). sono stati inoltre distinti dal sintema di zanco i depositi fluviali connessi con l’antico reticolato affluente, costituenti lembi di terrazzi fluviali sensibilmente incastrati dentro le valli: questi sedimenti, indicati nei fogli "torino est" e "trino" come sintema di palazzolo, corrispondono a depositi fluviali sabbioso-ghiaiosi e sono riferibili al pleistocene superiore. il legame di questi sedimenti con antichi percorsi del reticolato affluente del paleopo, e non con il reticolato idrografico attuale, è suggerito dall’andamento prevalentemente verso sse dei corsi d’acqua, che contrasta con l’andamento dell'idrografia attuale, drenante invece verso s o ssw. e’ da sottolineare come nel tempo il reticolato affluente sia migrato in risposta alla contemporanea deformazione dell’edif icio coll inare (fig. 13) (forno & boano, 2006). contemporaneamente al modellamento dell’antico percorso del f. po sul versante meridionale della collina di torino e del monferrato, su quello settentrionale si sviluppavano antichi andamenti di altri corsi d’acqua alpini, corrispondenti al f. dora riparia, al t. stura di lanzo, al t. orco e al f. dora baltea. in queste aree i sedimenti fluviali formano una successione visibilmente terrazzata (fig. 14), costituente lembi di terrazzo sospesi di alcune centinaia di metri rispetto all’attuale pianura padana. la differenza di quota tra i diversi termini è notevole: i sedimenti più antichi sono riconoscibili in prossimità alla cresta spartiacque a circa 600 m di quota; i sedimenti più recenti sono invece sospesi di alcune decine di metri sull’alveo attuale del f. po (220 m). i diversi lembi terrazzati sono stati raggruppati in tre sintemi, caratterizzati da suoli differenti e da un diverso grado di rimodellamento. anche nel caso di questi sintemi si è operata una scelta non basata sulla dimensione dei corpi geologici, conservati in lembi estremamente ridotti difficilmente cartografabili, bensì in base al loro significato geologico. i depositi fluviali conservati sul versante settentrionale della collina di torino e del monferrato rappresentano infatti i relitti dei settori distali dei conoidi alpini che si appoggiavano ai rilievi, coinvolti nella sensibile deformazione sinsedimentaria (fig. 15) (forno & lucchesi, 91 fig. 12 dettaglio del foglio “torino est” con l’indicazione dei sedimenti fluviali legati al “paleocollettore meridionale” (sintema di zanco) e del sovrastante loess eolico. 1: formazione di baldissero. 2: marne di s. agata fossili. 3: sintema di zanco. 4: sintema di palazzolo. 5: loess. 6: depositi di frana. detail of the “torino est” sheet with the indication of fluvial sediments connected to the “southern palaeocollector” (zanco synthem) and of the aeolian loess. 1: baldissero formation. 2: s. agata fossili marls. 3: zanco synthem. 4: palazzolo synthem. 5: loess. 6: landslide deposits. fig. 13 variazioni negli andamenti in pianta del rio ambuschetto (chieri) (a1, a2, a3, a4 e a5) progressivamente più prossimi alle direttrici attuali (a6). 1) sedimenti fluviali del sintema di san giovanni; 2) sedimenti fluviali del sintema di palazzolo; 3) depositi alluvionali attuali (da forno & boano, 2006). trend variations of ambuschetto stream (a1, a2, a3, a4 and a5) as they progressively reach the present trend (a6). 1) fluvial sediments of the san giovanni synthem; 2) fluvial sediments of the palazzolo synthem; 3) actual fluvial sediments (da forno & boano, 2006). la rappresentazione cartografica della ... 2005): quest'ultima è legata all'evoluzione pliocenico-pleistocenica del thrust frontale padano localizzato alla base del versante settentrionale del rilievo collinare (pieri & groppi, 1981; mosca, 2006). nella cartografia carg si è deciso infine di distinguere le successioni dell’area di pianura da quelli collinari: nell’area di pianura, più prossima all’area alpina, le successioni dei diversi bacini idrografici affiorano in aree ben distinte mentre nell’area collinare, più distale, le successioni sono invece legate agli apporti di più bacini. 4. i depositi gravitativi e colluviali l'analisi delle unità di modellamento fluviale non può prescindere da una corretta individuazione e rappresentazione degli accumuli gravitativi 92 fig. 14 successione di superfici terrazzate (indicate dalle frecce), sensibilmente sospese rispetto alla pianura, connesse con il “paleocollettore settentrionale”. succession of fluvial terraced surfaces connected to the “northern palaeocollector” (arrows), suspended above the actual po plain. fig. 15 i settori distali dei conoidi connessi con i corsi d’acqua alpini appaiono coinvolti nel sollevamento quaternario della collina di torino. cs: conoide del t. sangone. cd: conoide del f. dora riparia. cl: conoide del t. stura di lanzo. amra: anfiteatro morenico di rivoli-avigliana. immagine tratta da ambiente italia 3d portale cartografico nazionale. the distal sectors of the alpine alluvial fans are involved by the quaternary uplift of the collina di torino. cs: sangone alluvial fan. co: dora riparia alluvial fan. cl: stura di lanzo alluvial fan. amra: rivoli-avigliana morainic amphiteatre. image from ambiente italia 3d portale cartografico nazionale. m.g. forno, g. fioraso & p, boano che, per quanto di dimensioni ridotte, risultano estremamente diffusi nelle aree coll inari piemontesi. l'estensione areale dei singoli fenomeni è in genere inferiore a 0,3 km2; il loro spessore è compreso tra pochi metri ed alcune decine di metri e rispecchia il carattere pellicolare della maggior parte dei fenomeni gravitativi di questa regione, che il più delle volte coinvolgono unicamente le coltri colluviali, la successione quaternaria o la parte corticale e più alterata del substrato. i fenomeni, tuttavia, possono raggiungere concentrazioni piuttosto elevate, soprattutto nelle aree in cui il substrato è caratterizzato da una maggiore componente siltoso-argillosa (dela pierre et al., 2003): ad un aumento della frazione siltosa (ad esempio formazione di antognola e marne di monte piano) e argillosa (ad esempio complesso caotico della valle versa e complesso caotico di la pietra) corrisponde infatti un maggior grado di plasticità delle rocce, una minore permeabilità e una maggiore propensione allo sviluppo dei fenomeni di instabilità. nella maggior parte dei casi gli accumuli di frana sono connessi a fenomeni gravitativi sviluppati con cinematismi di tipo roto-traslazionale e di colata, in grado di coinvolgere i termini della successione fluviale quaternaria, rimobilizzandoli verso valle oppure seppellendoli. a queste tipologie di movimento si affiancano altri fenomeni di colata rapida (soil slip) legate alla saturazione e repentina fluidificazione dei sedimenti superficiali e delle coltri di alterazione del substrato: per le loro caratteristiche (dimensioni piuttosto contenute e spessore di materiale coinvolto in genere inferiore al metro) risultano difficilmente rilevabili se non nell'immediatezza dell'episodio di mobilizzazione. questi fenomeni hanno una notevole ripetitività e ubiquitarietà: si segnala, a titolo di esempio, che nel corso dell'evento alluvionale del novembre 1994 in alcuni settori del btp sono stati censiti ben 95 soil slip ogni km2 (susella, 1999). questi fenomeni rappresentano i principali responsabili del progressivo smantellamento dei versanti e dei sedimenti fluviali pleistocenici, che vengono ridistribuiti verso valle a formare coltri più o meno continue e potenti di prodotti colluviali: quest'ultimi, rivestendo in modo pressoché uniforme i versanti collinari, ostacolano l'osservazione dei corpi sedimentari quaternari e dei loro rapporti reciproci. i prodotti colluviali risultano facilmente riconoscibili grazie alla presenza di continui ed estesi affioramenti e subaffioramenti, localizzati soprattutto in corrispondenza di campi arati dove appaiono evidenziati dalla presenza di “chiazze” di colore bruno: l’estrema diffusione di questi depositi e il loro esiguo spessore, generalmente non superiore al metro, ha sconsigliato una loro rappresentazione cartografica, a favore di una più chiara ed esplicita delimitazione dei termini più antichi della successione quaternaria e pre-quaternaria. 5. conclusioni il progetto carg ha rappresentato un'occasione irripetibile per la ridefinizione del quadro stratigrafico di dettaglio, esteso su scala regionale, delle successioni pliocenico-quaternarie depostesi in ambito continentale, soprattutto per quelle aree trascurate nelle precedenti rappresentazioni cartografiche. l'abbandono dei classici criteri stratigrafici utilizzati fino agli anni '80 del secolo scorso, primi fra tutti quelli litostratigrafici e cronostratigrafici, ha imposto l'utilizzo di un nuovo approccio all’analisi stratigrafica, più oggettivo, basato sul riconoscimento delle superfici erosionali: l’individuazione di queste discontinuità rappresenta pertanto il nuovo principale obiettivo della cartografia geologica. nell'ambito dei rilievi collinari piemontesi il riconoscimento dei record stratigrafici (superfici di discontinuità e depositi) è stato tuttavia fortemente ostacolato dall'esiguità e dalla frammentarietà dei lembi di sedimenti conservati, dalla frequenza dei fenomeni franosi responsabili dello smantellamento dei rilievi e dall'ubiquitarietà della coltre colluviale. la scarsità degli elementi di datazione disponibili ha imposto la realizzazione di indagini di terreno estremamente dettagliate, anche per effetto dell'elevato tasso di antropizzazione delle aree collinari più prossime all'area metropolitana torinese: tali indagini, per quanto onerose, hanno consentito di individuare un significativo numero di sezioni geologiche naturali grazie alle quali è stato possibile svelare, almeno in parte, la reale complessità dell'assetto stratigrafico. la finalità squisitamente geologica della cartografia realizzata nell'ambito del progetto carg ha invece imposto di trascurare buona parte delle informazioni a carattere prettamente morfologico, ad esempio i lembi estremamente rimodellati, privi degli originari depositi fluviali e conservati unicamente come espressione morfologica della superficie di appoggio dei sedimenti; le osservazioni morfologiche hanno tuttavia agevolato la ricostruzione dell'assetto stratigrafico nei settori da più lungo tempo esposti al rimodellamento superficiale. bibliografia barbero d., boano p., colla m. t. & forno m. g. (2007) pleistocene terraced fluvial succession, northern slope of the torino hill. quaternary international, 171-172, 64-71. boano p. & forno m. g. (1996) carta geologica dell’area-tipo del villafranchiano. scala 1:20.000. in: carraro f. ed. (1996), revisione del vil lafranchiano nell'area-tipo di villafranca d'asti. il quaternario, it. journ. quat. sc., 9(1). boano p., forno m. g. & giardino m. (1997) deformazioni sinsedimentarie nella successione villafranchiana presso castelnuovo don bosco (asti). il quaternario, it. journ. quat. sc., 10(2), 355-358. boano p. & forno m. g. (1999) la successione “villafranchiana” nell’area di castelnuovo don bosco (asti). il quaternario, it. journ. quat. sc., 12(2), 161-194. boano p., boero v., forno m. g. & mottura a. (1999) significato di concentrazioni di resti fossili associati a un suolo e a prodotti colluviali entro la successione-tipo villafranchiana. geoitalia, 2° forum fist, 1999, 1, 203-206. boano p., forno m. g. & lucchesi s. (2004) pleistocene deformation of the collina di torino inferred from the modelling of their fluvial succession. il quaternario, it. journ. quat. sc., 17(2/1), 145-150. boni a., boni p., braga g. p., bruno g., casnedi r., corsi m., dal piaz g. b., gatto g. o., gatto p., motta e., perotto g., rampoldi r. & mosna s. (1970) foglio 69 "asti" della carta geologica 93la rappresentazione cartografica della ... d’italia alla scala 1:100.000. iiª ed., serv. geol. it., roma. bortolami g., crema g. c., malaroda r., petrucci f., sacchi r., sturani c., tagliavini s. & venzo s. (1969) foglio 56 "torino" della carta geologica d’italia alla scala 1:100.000. iiª ed., serv. geol. it., roma. borson e. (1830a) mémoire su quelques ossements fossiles trouvés en piémont. lu à la séance du 6 juin, torino, 33-46. borson e. (1830b) catalogue raisonné du musée d’histoire naturelle de l’académie de turin. torino, 740 pp. campanino f., forno m. g., mottura a., ormezzano d. & sala b. (1994) stephanorhinus jeanvireti (guérin, 1972) (rinocerotidae, mammalia) from roatto near villafranca d'asti, nw italy revision of the specimen from dusino. boll. museo reg. sc. nat. torino, 12, 439-499. carraro f. (1976) diversione pleistocenica nel deflusso del bacino piemontese meridionale: un'ipotesi di lavoro. gruppo di studio del quaternario padano, 3, 89-100. carraro f., forno m. g., giardino m. & paro l. (2005) field trip guide. 14th meeting of the association of european geological societies, september 23th 2005, torino hill. il quaternario, it. journ. quat. sc., 18(2), 3-55. carraro f. ed. (1996) revisione del villafranchiano nell’area-tipo di villafranca d’asti. il quaternario, it. journ. quat. sc., 9(1), 5-120. compagnoni r. & forno m. g. (1992) significato geologico di depositi fluviali ghiaiosi pleistocenici medi nella collina di torino. il quaternario, it. journ. quat. sc., 5(1), 105-122. consiglio nazionale delle ricerche (1990) structural model of italy, scale 1:500.000, sheet 1. progetto finalizzato geodinamica. s.e.l.c.a., firenze. cuvier g. (1806a) sur les éléphans vivans et fossiles. ann. mus. hist. nat. turin, 8, 1-13. cuvier g. (1806b) sur differentes dents du genre des mastodontes. ann. mus. hist. nat. paris, 8, 401-414. dela pierre f., piana f., boano p., fioraso g., forno m. g., polino r. & clari p. (2003) carta geologica d'italia. foglio 157 "trino" alla scala 1:50.000. apat, agenzia per la protezione dell'ambiente e per i servizi tecnici dipartimento difesa del suolo, roma. de mortillet (1864) l’epoque quaternaire dans la vallé du pô. bull. soc. géol. fr., sér. 2, 2, 138-151. festa a., boano p., irace a., lucchesi s., forno m. g., dela pierre f., fioraso g. & piana f. (in stampa) carta geologica d'italia alla scala 1:50.000. foglio 156 “torino est”. ispra dipartimento difesa del suolo, roma. forno m. g. (1980) evidenza di un drenaggio abbandonato nel settore settentrionale dell'altopiano di poirino (torino). geogr. fis. dinam. quat., 3, 61-65. forno m. g. (1982) studio geologico dell'altopiano di poirino (torino). geogr. fis. dinam. quat., 5, 129-162. forno m. g., ben g., boano p., bocca p., boero v. & compagnoni r. (2002) lembi di depositi fluviali provenienti dai bacini alpini nordoccidentali sulla collina di torino presso villa gualino (nw italy). il quaternario, it. journ. quat. sc., 15(2), 175-185. forno m. g. & boano p. (2006) riorganizzazione del reticolato idrografico nella collina di torino in relazione alla deformazione quaternaria . i l quaternario, it. journ. quat. sc., 19(2), 215-222. forno m. g. & lucchesi s. (2005) la successione fluviale terrazzata pleistocenica dei versanti occidentale e nordoccidentale della collina di torino. il quaternario, it. journ. quat. sc., 18(2), 123-134. gastaldi b. (1860) su alcune ossa di mammiferi fossili del piemonte. atti soc. it. sc. nat., 2, 213-216. gastaldi b. (1861) cenni sui vertebrati fossili del piemonte. mem. r. acc. sc. torino, ser. 2, 19, 19-89. germani d., angiolini l. & cita m. b. (2003) guida italiana alla classificazione e alla terminologia stratigrafica. apat. agenzia per la protezione dell'ambiente e per i servizi tecnici. quaderni, ser. 3, 9, 155 pp. mosca p. (2006) neogene basin evolution in the western po plain (nw italy). insights from seismic interpretation, subsidence analysis and low temperature (u-th)/he thermochronology. ph.d. thesis. vri je universiteit, amsterdam, the netherlands, 190 pp. pareto m. (1865) note sur la subdivision que l’on pourrait établir dans les terrains de l’appenin septentrional. bull. soc. géol. fr., sér. 2, 22, 210-277. pasquaré g., abbate e., bosi c., castiglioni g. b., merenda l., mutti e., orombelli g., ortolani f., parotto m., pignone r., polino r., premoli silva i. & sassi f. p. (1992) carta geologica d’italia 1:50.000. guida al rilevamento. ist. poligr. di stato, roma, 203 pp. pieri m. & groppi g. (1981) subsurface geological structure of the po plain, italy. quad. cnr, prog. fin. geodinamica, roma, pubbl. 414, 1-13. sacco f. (1895) le rhinocéros de dusino (rhinoceros etruscus falc. var. astensis sacc.). arch. mus. hist. nat. lyon, 6, 1-31. sismonda e. (1849) lettera a michelin del 23 ottobre 1849 (con annuncio del ritrovamento di scheletro di mastodonte negli scavi della ferrovia). bull. soc. géol. france, 2(7), p. 49. sismonda e. (1852) osteografia di un mastodonte angustidente. mem. r. acc. sc. torino, ser. 2, 12, 175-239. susella g. (1999) eventi alluvionali in piemonte: 2-6 novembre 1994, 8 luglio 1996, 7-10 ottobre 1996. regione piemonte, 415 pp. vezzoli g., forno m.g., lombardo b., cadoppi p., tronchero v. & rossello e. (2005) comparison between modern and pleistocene dense mineral suites: a key to unravelling the sedimentary evolution of the torino hill (western alps, italy). in: carraro f. (ed.) natural hazards related to recent geological processes and regional evolution. 14th meeting of the association of european geological societies (torino, 19-23 september 2005). abstracts. centro stampa arpa piemonte, torino, p. 58. 94 ms. ricevuto il 4 novembre 2008 testo definitivo ricevuto il 3 aprile 2009 ms. received: november 4, 2008 final text received: april 3, 2009 m.g. forno, g. fioraso & p, boano << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /none /binding /left /calgrayprofile (dot gain 20%) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /error /compatibilitylevel 1.4 /compressobjects /tags /compresspages true /convertimagestoindexed true /passthroughjpegimages true /createjdffile false /createjobticket false /defaultrenderingintent /default /detectblends true /colorconversionstrategy /leavecolorunchanged /dothumbnails false 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pleistocene and holocene bats of latium (central italy) leonardo salari1 & tassos kotsakis2 1 dipartimento di scienze della terra, università di roma sapienza, roma 2 dipartimento di scienze geologiche and centro di ecologia evolutiva, università di roma tre, roma correspondent author: t. kotsakis <kotsakis@uniroma3.it> abstract: salari l. & kotsakis t., late pleistocene and holocene bats of latium (central italy). in this paper the late pleistocene and holocene fossil and subfossil bats collected in latium have been examined. seventeen taxa belonging to eight genera and to four families were reported in the list of fossil species (the presence of three additional species in the fossil assemblages is dubious). fifteen of them are reported as living today in the region. exceptions are the boreal species myotis dasycneme and eptesicus nilssonii. on the other hand the presence in latium of myotis mystacinus and barbastella barbastellus after 1980 is dubious. the majority of the fossil remains of bats collected in the sites of latium (especially in terms of number of specimens) belong to troglophilous species, forming reproductive and/or hibernating colonies in caves (rhinolophidae, myotis myotis, m. blythii, m. capaccinii and miniopterus schreibersii). bats roosting in trees or rock fissures (nyctalus noctula and tadarida teniotis) or visiting the caves only during colder winters (myotis bechsteinii and members of the genera pipistrellus and hypsugo) are quite rare. during the colder stages of the late pleistocene, the coastal regions of latium must have played the role of refugia for animals and plants, as testified by several thermophilous mediterranean sensu stricto species of bats, e.g. rhinolophus euryale, m. capaccinii, pipistrellus kuhlii, m. schreibersii and t. teniotis. riassunto: salari l. & kotsakis t., chirotteri del pleistocene superiore e dell’olocene del lazio (italia centrale). in questo lavoro vengono esaminate le associazioni fossili e subfossili a chirotteri del pleistocene superiore e dell’olocene della regione lazio. sono state individuate diciassette specie appartenenti a otto generi e quattro famiglie (la presenza di ulteriori tre specie è dubbia). quindici di queste specie vivono attualmente nella regione. sono assenti le specie boreali myotis dasycneme e eptesicus nilsonii. d’altra parte la presenza nel territorio della regione lazio di myotis mystacinus e barbastella barbastellus dopo il 1980, è dubbia. la maggioranza dei chirotteri raccolti nei siti fossiliferi laziali (in particolar modo se si considera il numero degli individui classificati con certezza) appartiene a specie troglofile che formano colonie riproduttive e/o ibernanti in grotte (rhinolophidae, myotis myotis, m. blythii, m. capaccinii e miniopterus schreibersii). specie viventi sugli alberi o in fessure (nyctalus noctula e tadarida teniotis) oppure che visitino le grotte solamente durante gli inverni particolarmente freddi (myotis bechsteinii e i membri dei generi pipistrellus e hypsugo) sono piuttosto rare. durante gli stadi freddi del pleistocene superiore almeno due specie boreali hanno fatto la loro comparsa nel lazio ma, d’altra parte, le regioni costiere del lazio devono aver svolto il ruolo di area rifugio come testimonia la presenza di molte specie termofile, mediterranee sensu stricto, nei vari siti fossiliferi (rhinolophus euryale, m. capaccinii, pipistrellus kuhlii, m. schreibersii e t. teniotis). key words: bats, late pleistocene, holocene, central italy. parole-chiave: chirotteri, pleistocene superiore, olocene, italia centrale. 1. introduction bats are very useful for paleoecological reconstructions: they are flying insectivorous animals, and they rapidly react to climatic and environmental changes. they are also good indicators for reconstruction of hypogean microclimates. their abundance in the cave sediments testifies the absence or sporadic presence of prehistoric humans in these sites during the same timespan. instead, they have low value as biochronologic indicators and probably for this reason few people is interested to their systematic study. our aims are to point out palaeobiogeographical, palaeoecological, microclimate, human activity and, if possible, biochronological indications for the late pleistocene and holocene bat assemblages of latium. 2. materials and methods the paper discusses the fossil and subfossil records of the late pleistocene and early holocene bats of latium (fig. 1). it is a first attempt at a regional synthesis and it shows several uses in palaeontology of bat remains. the data were based on fossil assemblages directly investigated by the authors (grotta breuil, grotta barbara, grotta del fossellone, riparo salvini, grotta di cittareale, and grotta mora cavorso) or on material reported in the literature (grotta di sant’agostino and grotta polesini). the bats were collected from fossiliferous sites spanning from 55 ky bp (grotta sant’agostino) to less than 7 ky bp (grotta mora cavorso). data about the first (warm) stage of the late pleistocene (mis 5) are lack l. salari & t. kotsakis 122 fig. 1 location of the sites. ubicazione dei siti. ing. the fossil assemblages were assigned to four distinct time periods (from the oldest to the most recent one): 1) grotta di sant’agostino (tozzi, 1970) to the last stage of the first pleniglacial (last stage of mis 4 and beginning of mis 3); 2) grotta breuil (kotsakis, 1991; alhaique et al., 1996; salari & di canzio, 2009), grotta barbara (salari & di canzio, 2009 and unpublished data) and grotta del fossellone (unpublished data) to the last part of the interpleniglacial (final stages of mis 3 and beginning of mis 2); 3) grotta mora cavorso (salari et al., 2010, this volume), riparo salvini (zhuowei & kotsakis, 2008), grotta di cittareale (argenti et al., 2008) and grotta polesini (radmilli, 1974) to the late glacial (final stages of mis 2); 4) grotta mora cavorso to the early holocene (rolfo et al., 2009). in three caves, the fossil bats were associated with different lithic industries and/or cultural horizons: grotta barbara (mousterian and aurignacian), grotta del fossellone (mousterian, aurignacian and advanced upper paleolithic), grotta mora cavorso (final epigravettian and neolithic) (tabs. 1 and 2). for the numerical data of micro and macro faunas and the detailed stratigraphies of the various sites, see the literature cited. 3. systematic observations the fossil remains from the investigated sites of latium do not show major morphological and/or morphometric differences from living species. however, paleontologists are confronted with some issues raised by recent applications of modern bioacoustic and molecular biology techniques (combined with conventional ones based on morphological and morphometric criteria), which identified and/or erected new species. in particular, some subspecies or geographic varieties of species belonging to the genera myotis, pipistrellus and plecotus were elevated to the rank of good species, but the lack of sound morphometric data for their taxonomic determination did not permit to adequately assess them. the fossil remains potentially falling into the above taxa (e.g. pipistrellus pygmaeus, leach, 1825) and supposedly having the same variability as the one of pipistrellus pipistrellus (schreber, 1774), or those of the cryptic species of myotis mystacinus (kuhl, 1817) were attributed to the traditionally more known species, followed by sensu lato (s.l.) in accordance with “linee guida per il monitoraggio dei chirotteri” (agnelli et al. 2004) for reports of these taxa prior to 1999-2000. this is the case of m. mystacinus s.l. of grotta breuil and p. pipistrellus s.l. of grotta barbara. also the distinction between hypsugo savii and species of larger size of the genus pipistrellus is problematic. the morphology and size of the distal epiphysis of the humerus are identical (see felten et al., 1973) and the variability of the size of the lower tooth row largely overlaps. on the other hand the morphology and position of the upper incisors suggests a clear discrimination between the cranial remains of pipistrellus kuhlii (kuhl, 1817), those of pipistrellus nathusii (keyserling & blasius, 1839) and those of h. savii (see miller, 1912; lanza & agnelli, 2002) but as is known incisors are rarely recovered from fossil remains. in these cases (e.g. at riparo salvini), the fossil remains were attributed to hypsugo vel pipistrellus (zhuowei & kotsakis, 2008). conversely, at grotta barbara, two mandibular branches were ascribed to p. kuhlii (salari & di canzio, 2009), because the size of the lower tooth row (c-m3 alveolar length = 5.4 mm) lay close to the upper limit of the size range of p. kuhlii (miller, 1912; benda et al., 2003) and was not included in the overlap range between the above three species. the attribution of some remains of a “middle size” rhinolophus collected in grotta breuil is uncertain, because the morphology of the fragmentary specimens not allow to assign the fossils to specific level, and the dimensions are inside the range of both rhinolophus euryale blasius, 1853 and rhinolophus mehelyi matschie, 1901. 4. biochronological indications pleistocene bats appear to have a low value as biostratigraphic indicators. only two extinct species, both from the early and middle pleistocene, were discovered in italy (tata & kotsakis, 2005). the species known in the late pleistocene are all extant and, except for myotis dasycneme (boie, 1825), they are all currently distributed in italy (agnelli et al., 2004). m. dasycneme is reported from a few late pleistocene sites of north and central italy, always in “cold” assemblages, but is not reported in any of the few known holocene sites. hence, based on the occurrence of m. dasycneme at grotta di cittareale, the chiropteran assemblage was ascribed to one of the last cold stages of the late pleistocene, probably the younger dryas (argenti et al., 2008). late pleistocene and holocene bats of latium (central italy) 123 fig. 2 grotta breuil: a) nyctalus noctula, distal epiphysis of left humerus; grotta barbara: b) rhinolopus ferrumequinum, distal epiphysis of right humerus; c) pipistrellus kuhlii, fragment of right mandibular ramus, labial view; d) pipistrellus pipistrellus s.l., fragment of right mandibular ramus, labial view; grotta del fossellone: e) rhinolophus euryale, distal epiphysis of left humerus; f) myotis blythii, distal epiphysis of left humerus; g) myotis capaccinii, distal epiphysis of right humerus; h) eptesicus nilssonii, distal epiphysis of left humerus (h1 external, h2 internal, h3 dorsal views); i) miniopterus schreibersii, distal epiphysis of right humerus; riparo salvini: l) hypsugo vel pipistrellus, distal epiphysis of left humerus; m) tadarida teniotis, distal epiphysis of right humerus, processus styloideus broken; grotta di cittareale: n) myotis dasycneme, distal epiphysis of left humerus; o) myotis bechsteinii, distal epiphysis of right humerus; grotta mora cavorso: p) myotis bechsteinii, fragment of left mandibular ramus, labial view; q) rhinolophus hipposideros, skull, dorsal view. all the humeri are illustrated in external view. scale bar = 2 mm. grotta breuil: a) nyctalus noctula, omero sinistro, epifisi distale; grotta barbara: b) rhinolopus ferrumequinum, omero destro, epifisi distale; c) pipistrellus kuhlii, frammento di ramo mandibolare destro, norma labiale; d) pipistrellus pipistrellus s.l., frammento di ramo mandibolare destro, norma labiale; grotta del fossellone: e) rhinolophus euryale, omero sinistro, epifisi distale; f) myotis blythii, omero sinistro, epifisi distale; g) myotis capaccinii, omero destro, epifisi distale; h) eptesicus nilssonii, omero sinistro, epifisi distale (h1 norma esterna, h2 norma interna, h3 norma dorsale); i) miniopterus schreibersii, omero destro, epifisi distale; riparo salvini: l) hypsugo vel pipistrellus, omero sinistro, epifisi distale; m) tadarida teniotis, omero destro, epifisi distale (processo stiloide rotto); grotta di cittareale: n) myotis dasycneme, omero sinistro, epifisi distale; o) myotis bechsteinii, omero destro, epifisi distale; grotta mora cavorso: p) myotis bechsteinii, frammento di ramo mandibolare sinistro, norma labiale; q) rhinolophus hipposideros, cranio, norma dorsale. tutti gli omeri sono illustrati in norma esterna. scala della barra = 2 mm. l. salari & t. kotsakis 124 tab. 1 schematic synthesis of stratigraphy and chronology of the sites. schema stratigrafico e cronologico dei siti considerati. 5. palaeobiogeographical indications from the end of the pleistocene to the present, various animal species changed their home ranges. the majority of the bat species identified in the pleistocene horizons are still present in latium, except for m. dasycneme, m. mystacinus s.l., eptesicus nilssonii (keyserling & blasius, 1839), barbastella barbastellus (schreber, 1774) and possibly r. mehelyi (tabs. 2 and 3). today, m. dasycneme has its southernmost limit of distribution in north-eastern croatia and is regarded as an “accidental species” in italy: the only reported specimen likely erratic was captured in trento in 1881 (lanza & agnelli, 2002; agnelli et al., 2004). m. dasycneme fossils are known since the early pleistocene (gelasian = late villányian = middle villafranchian) in central-eastern europe (horàček & hanák, 1989) and signalled in some middle and late pleistocene and holocene sites of asia and central-eastern europe (horàček & hanák, 1989 with references; piksa & wołoszyn, 2001; ochman, 2003; ochman & wołoszyn, 2003; postawa, 2004; rossina, 2006). in italy, it is known in the late middle and late pleistocene of grotta del broion (veneto, pasa, 1953), riparo mezzena (veneto, bartolomei & pasa, 1980), grotta del vento (marche, esu et al., 1990), and (as we have seen in the previous paragraph) in the grotta di cittareale (latium, argenti et al., 2008). this locality is the southernmost limit of this species, even considering its distribution in the pleistocene. grotta del fossellone 3 (advanced upper palaeolithic) was attended by e. nilssonii, a northern species and the only one among all the bats in the world which reproduces even beyond the arctic circle (as far as 70° 25’ n) (rydell et al., 1994). its current range of distribution includes central and northern europe, extending from the northern balkans through the palearctic asia to sahalin, korea and japan (agnelli et al., 2004). currently, its southernmost limit of distribution in europe is the south-eastern alpine arch and the northern balkans, with isolated colonies in the rila mountains in bulgaria (hanák & horàček, 1986; agnelli et al., 2004). e. nilssonii fossils are known since the early middle pleistocene in poland (wołoszyn, 1987). during the late pleistocene and early holocene, this species settled in various sites of central europe and of the former soviet union (crimea, siberia, russian far east) (rydell, 1993 with references; horáček, 1995; popov, 2000; piksa & wołoszyn , 2001; ochman, 2003; ochman & wołoszyn, 2003; rossina, 2006) and only at grotta del broion (veneto) in italy (pasa, 1953). grotta del fossellone represents the southernmost limit of this species in europe, even considering its distribution in the pleistocene. boreal species, e.g. m. dasycneme and e. nilssonii presumably deserted the region and the peninsula owing to climate warming in the holocene. conversely, the absence of nemoral species, such as m. mystacinus and b. barbastellus, both distributed in most part of italy, is relatively recent (after 1980); this absence (if con late pleistocene and holocene bats of latium (central italy) 125 firmed) is likely to be due to progressive deforestation and intense urbanisation of the region in the last century. another interesting paleogeographic issue is the recent settlement of animal and plant species in central-northern europe. during the coldest periods of the late pleistocene and, namely, the last glacial maximum (lgm), the iberian and italian peninsulas and the balkans played the role of main glacial refugia for many “temperate” or “warm” animal and plant species, which then repopulated the rest of europe (stewart & lister, 2001; sommer & nadachowski, 2006; tříska, 2009). this phenomenon certainly involved the majority of european bats. considering only the stratigraphic successions supported by estimated radiometric dates, fahlke (2009) reported that: i) bats deserted the area north of the alps in the lgm; and ii) it was only in the first stages of the late glacial, during the bølling-allerød temperate oscillations, that eptesicus serotinus (schreber, 1774) timidly returned to the area, followed by plecotus auritus (linnaeus, 1758) and b. barbastellus. in effect, few other species, including myotis bechsteinii (kuhl, 1817), myotis nattereri (kuhl, 1817), myotis brandtii (eversmann, 1845), myotis daubentonii (kuhl, 1817), e. nilssonii and p. nathusii, are reported in the late glacial successions (horáček, 1995; ochman, 2003), while the other species now present in central-northern europe must have returned there only in the holocene (horáček, 1995; blant et al., 2008; ruedi et al., 2008; fahlke, 2009). even in some regions south of the alps (e.g. canton ticino), repopulation took place in the holocene (blant et al., 2008). in the late pleistocene, latium, and generally central-southern italy, hosted many species which are now largely distributed in central-northern europe, including rhinolophus hipposideros (bechstein, 1800), myotis myotis (borkhausen, 1797), m. bechsteinii, m. dasycneme, m. mystacinus, nyctalus noctula (schreber, 1774), e. nilssonii and b. barbastellus. additionally, especially in the coastal sites of latium, various species of mediterranean s.s. thermophilous bats, e.g. p. kuhlii, r. euryale, myotis capaccinii (bonaparte, 1837), miniopterus schreibersii (kuhl, 1817) and tadarida teniotis (rafinesque, 1814), cohabited with “cold” species, e.g. marmot, hamster, wolverine, ermine and steinbock, even in the relatively colder stages of the late pleistocene. grotta barbara 1 (mousterian) was inhabited by p. kuhlii, a thermophilous species which is very anthropophilous today (lanza & agnelli, 2002; agnelli et al., 2004). fossils of p. kuhlii are rare, with a few records in the late middle and late pleistocene and holocene in germany, russia and turkey (salari & di canzio, 2009 with references). p. kuhlii of grotta barbara is the first and, for the time being, the only occurrence in italy. 6. palaeoecological indications the favourite foraging environments of the identified species shed more light on the environment surrounding the investigated sites (tab. 3). moreover, settlements of species usually hibernating in hollow trees or rock fissures (n. noctula, e. nilssonii e t. teniotis) or, rarely, in caves (m. bechsteinii and members of the genera pipistrellus and hypsugo) may indicate periods of more adverse climate or particularly harsh winters. these climatic and environmental indications are usually consistent with those provided by the other identified taxa, especially ungulates and rodents, and may complement and/or extend the data provided by the other animal and/or plant taxa. for instance, in the most ancient strata (cuts 2416) of riparo salvini, myotis blythii (tomes, 1857) is dominant and followed by m. capaccinii and m. schreibersii. this infers that the surrounding environment was fairly open, with prairies alternating with sparse woods and wetlands. in the other cuts 15-7, m. blythii is still dominant and followed by rhinolophus ferrumequinum (schreber, 1774), hypsugo vel pipistrellus and n. noctula, suggesting similar but less humid environments and climatic transition from conditions similar to present ones to colder conditions. the paleoenvironmental clues given by bats match those provided by rodents. the latter passed from an assemblage with dominant microtus (terricola) savii (de selys-longchamps, 1838), followed by apodemus sylvaticus (linnaeus, 1758), arvitaxon / sites g ro tt a di s . a go st in o g ro tt a br eu il g ro tt a ba rb ar a 1 g ro tt a de l f os se llo ne 1 g ro tt a ba rb ar a 2 g ro tt a de l f os se llo ne 2 g ro tt a de l f os se llo ne 3 g ro tt a m or a ca vo rs o 1 ri pa ro s al vi ni g ro tt a di c it ta re al e g ro tt a po le si ni g ro tt a m or a ca vo rs o 2 rhinolophus ferrumequinum x x x x x x x x x rhinolophus hipposideros x x x rhinolophus euryale x x x rhinolophus euryale/mehelyi x myotis myotis x x myotis blythii x x x x x x x x x myotis myotis/ blythii x x myotis capaccinii x x x myotis dasycneme x myotis bechsteinii x x myotis emarginatus x x myotis mystacinus s.l. x myotis sp. x pipistrellus pipistrellus s.l. x pipistrellus kuhlii x hypsugo vel pipistrellus x eptesicus nilssonii x nyctalus noctula x x barbastella barbastellus x miniopterus schreibersii x x x x tadarida teniotis x x x total taxa 2 12 5 1 2 1 6 2 7 5 5 4 tab. 2 late pleistocene and early holocene bats of latium. (for the spelling of the species names see simmons, 2005). quadro riepilogativo dei taxa del pleistocene superiore e olocene antico del lazio. (per l’ortografia dei nomi delle specie cf. simmons, 2005). l. salari & t. kotsakis 126 taxon latium fossil latium today hibernacula temperatures of hibernation foraging environment zoogeographical patterns rhinolophus ferrumequinum x x caves 7 12 °c mixed mediterranean s.l. rhinolophus euryale x x caves 10 12 °c woods mediterranean s.s. rhinolophus mehelyi ? caves 11 13 °c woods mediterranean s.s. rhinolophus hipposideros x x caves 4 12 °c mixed mediterranean s.l. myotis myotis x x caves 2 12 °c woods mediterranean s.l. myotis blythii x x caves 4 14 °c open mediterranean s.l. myotis capaccinii x x caves 4 15 °c woods mediterranean s.s. myotis dasycneme x caves, hollow trees 0 7 °c forests boreal myotis daubentonii x caves 0 10 °c forests boreal myotis bechsteinii x x hollow trees, caves 1 10 °c woods nemoral myotis emarginatus x x caves 5 9 °c miscellaneous mediterranean s.l. myotis mystacinus s.l. x ? caves 2 8 °c miscellaneous nemoral myots nattereri x caves 2 8 °c woods nemoral pipistrellus kuhlii x x buildings, rock fissures ? miscellaneous, anthropophilous mediterranean s.s. pipistrellus nathusii ? x rock fissures, buildings ? woods nemoral pipistrellus pipistrellus s.l. x x buildings, hollow trees 0 6 °c woods, anthropophilous mediterranean s.l. pipistrellus pygmaeus ? x hollow trees, buildings ? miscellaneous, anthropophilous nemoral ? hypsugo savii ? x buildings, caves ? miscellaneous, anthropophilous mediterranean s.s. eptesicus nilssonii x rock fissures, buildings -6 7 °c forests boreal eptesicus serotinus x buildings, caves 2 4 °c miscellaneous mediterranean s.l. nyctalus lasiopterus ? hollow trees -6 6 °c forests nemoral nyctalus leisleri x hollow trees ? woods nemoral nyctalus noctula x x hollow trees > -7 °c forests nemoral barbastella barbastellus x ? caves 0 8 °c forests nemoral plecotus auritus x hollow trees, caves 2 5 °c forests boreal plecotus austricus x caves, hollow trees 2 12 °c woods mediterranean s.l. miniopterus schreibersii x x caves 4 12 °c miscellaneous mediterranean s.s. tadarida teniotis x x rock fissures 0 10 °c rocky mediterranean s.s. tab. 3 late pleistocene and early holocene chiropteran taxa, extant bat fauna of latium and key ecological features (data from horáček et al., 2000; lanza & agnelli, 2002; agnelli et al., 2004; amori et al., 2009). (for the spelling of the species names see simmons, 2005). confronto tra i taxa del pleistocene superiore e olocene antico con l’attuale chirotterofauna del lazio, e schema sintetico di alcune caratteristiche ecologiche (dati da horáček et al., 2000; lanza & agnelli, 2002; agnelli et al., 2004; amori et al., 2009). (per l’ortografia dei nomi delle specie cf. simmons, 2005). cola amphibius (linnaeus, 1758) and eliomys quercinus (linnaeus, 1766), to an assemblage with dominant m. (t.) savii and microtus (microtus) arvalis (pallas, 1778), followed by a. sylvaticus, e. quercinus and a. amphibius together with chionomys nivalis (martins, 1842) (zhuowei & kotsakis, 2008). the species haunting woods and forests are always associated with cervids and/or glirids. t. teniotis (rupiculous species) is associated with the steinbock at grotta breuil, grotta barbara and riparo salvini. it is worth noting that: i) in the late glacial succession of grotta polesini (radmilli, 1974), in spite of difficulties in correlating the various trenches (alhaique & bietti, 2007), r. ferrumequinum and m. schreibersii disappears and b. barbastellus gradually increases upon the appearance of the marmot and of the wolverine; or ii) at grotta s. agostino (tozzi, 1970), upon the appearance of the rhinoceros (stratum a2), only m. blythii remains, accompanied by r. ferrumequinum in the underlying strata. in other instances, the paleoenvironmental indications given by bats are the only ones (e.g. at grotta di cittareale) or improve the understanding of available data, e.g. at grotta barbara and grotta mora cavorso. at grotta barbara 1 (mousterian), the percentage ratios between the identified cervids (red deer, fallow deer, roe deer) point to two different possible scenarios in the pontina plain: a relatively open environment with scarce or localised forest cover or diffuse mediterranean “macchia” (caloi & palombo, 1989). the dominance of m. blythii validates the former assumption. at grotta mora cavorso 2 (neolithic), ungulates include the red deer and domestic ruminants; only m. blythii shows that the upper aniene river valley and the simbruini mountains, too, were in part covered by prairies. late pleistocene and holocene bats of latium (central italy) 127 considering that only the lesser mouse-eared bat is indicative of open spaces and that various species populate miscellaneous or mixed environments, the only inconsistency concerns the most recent part of the mousterian succession of grotta breuil. among the ungulates of stratum 3, the steinbock prevails over the red deer, implying drier and colder conditions than in the underlying strata where the red deer prevails over the steinbock (alhaique & bietti, 2007). among bats, r. euryale is dominant, testifying a good forest cover and a temperate climate, more or less as in the underlying strata. this inconsistency may be redressed by: i) assuming that the fossil remains are not coeval (bats must have colonised the cave only after the mousterians deserted it, see later on); or ii) recalling the previous points made about the role of the coastal sites of latium as glacial refugia for various species of thermophilous bats. 7. microclimatic indications the microclimate of caves has a paramount importance in the selection of diurnal roosts or reproductive and hibernating environments. each species has its own tolerability to narrow ranges of temperature and humidity (generally low temperature and high humidity). nonetheless, the temperature and humidity of a cave may vary depending on its size and morphology, as well as on the number and orientation of its openings. large-sized caves may have a variety of microclimates (more or less constant temperatures but variable humidity, owing above all to draughts of air) and each species selects the sites which best suit its preferences. usually, bats have not been hunted by prehistoric humans for food or other purposes, but may be occasional preys of nocturnal raptors (strigiforms): in the pellets regurgitated by these raptors, bats account for as little as 1% of the preys, including rodents, small birds and insectivores (kowalski, 1990, 1995; sevilla garcía, 1998). hence, most of the fossil remains in the investigated sites are naturally accumulated bones of bats which died in their caves. the lack of juvenile remnants (suggestive of attendance in the spring or summer reproductive period), except for an immature specimen found at grotta breuil, suggests that the bats are died for poor subcutaneous fat reserve or other causes during hibernation. this is why the investigated thanatocoenoses can give further insight into the winter microclimate, at least around the excavated area. for instance, it may be assumed that: at grotta breuil (strata 6-3), the winter microclimate remained fairly constant (on average around 10-12° c) and with high humidity; the winter temperature fluctuated around 5-6° c at grotta barbara 1 (mousterian), around 7°c at grotta di cittareale and rose slightly at grotta mora cavorso (from roughly 7-10°c to 7-12° c) between the final stages of the late pleistocene and holocene (neolithic). 8. human activity indications today some species of bats, particularly of the genera pipistrellus and hypsugo are anthropophilous, living in the urban areas and roosting in the buildings (miller, 1912; lanza & agnelli 2002; agnelli et al., 2004). however the troglophilous bats are wild and are not commensal to humans and, usually, the occurrence of bat remains in the sediments of caves evidences the absence or sporadic presence of prehistoric humans in the time interval during which the sediments were deposited (rossina, 2006; salari & di canzio, 2009; salari, 2010). noise, light and heat from human attendance change hypogean environments. a particular source of disturbance to bats is the smoke from human fires, which may also alter the microclimate of caves. the disturbance is higher in winter or during the reproductive period and may cause the bats to desert the caves in search of more suitable ones (marsico, 2003; agnelli et al., 2004). it is perhaps not by chance that the percentage of bats at grotta breuil is almost specular to the percentages of traces of human activity left on the bones of large mammals (alhaique & bietti, 2007; alhaique, in litteris): peak of human activity corresponds to low bat attendance (stratum 7); a sharp drop in human activity is associated with a strong increase in bat attendance (stratum 6); scarce remains of bats and equally scarce human activity characterise strata 5 and 4; minimum of human activity in stratum 3 is indicative of peak of bat attendance (tab. 4). in stratum 3 can not be excluded that bats may have settled in the cave only after the mousterians abandoned it. tab. 4 percentages of the number of identified remains of large mammals, number of large mammals with traces of human activity and number of identified bat remains at grotta breuil (data from alhaique & bietti, 2007; salari & di canzio, 2009; alhaique in litteris). confronto tra il numero dei resti determinati dei grandi mammiferi, il numero di tracce di attività umana sui resti di grandi mammiferi ed il numero dei resti determinati di chirotteri di grotta breuil (in percentuale)(dati da alhaique & bietti, 2007; salari & di canzio, 2009; alhaique in litteris). the alternating attendance of caves by bats and humans may have been multi-year cyclical or seasonal (late spring-early autumn for humans, late autumn-early spring for bats). based on available data on seasonal human attendance of grotta s. agostino, grotta breuil, grotta del fossellone 2 (aurignacian), riparo salvini and grotta polesini (alhaique & bietti, 2007) multi-year cycles seem more likely. acknowledgements we are grateful to gianni amori and federico masini for the useful suggestions. we thank also the late amilcare bietti, francesca alhaique, emanuele di canzio, margherita mussi, mario f. rolfo and the “gruppo grotte pipistrelli cai terni” for their support and who have allowed the access to the bat remains. l. salari & t. kotsakis 128 references agnelli p., martinoli a., patriarca e., russo d., scaravelli d. & genovesi p. (2004 ) linee guida per il monitoraggio dei chirotteri: indicazioni metodologiche per lo studio e la conservazione dei pipistrelli in italia. quad. conserv. natura, 19, min. ambiente ist. naz. fauna selvatica, 216 pp. alessio m., alhaique f., allegri l., bietti a., branca m., d’arpino a., improta s., kuhn s., palmieri a.m. & preite martinez m. (1993) new results on the upper paleolithic site of riparo salvini (terracina, italy). quat. nova, 3, pp. 105-150. alhaique f. & bietti a. (2007) strategie di insediamento e di sussistenza nel lazio centro-meridionale fra paleolitico medio e mesolitico. atti ist. ital. preist. protost., xl riun. scient., pp. 55-78. alhaique f., bietti a., capasso barbato l., grimaldi s., kotsakis t., kuhn s., lemorini c., manzi g., recchi a. & stiner m. (1996) nuovi risultati sul musteriano finale di grotta breuil (s. felice circeo, latina). in: c. peretto & s. milliken (eds), l’adattamento umano all’ambiente, passato e presente. atti xi congr. antropol. ital., pp. 177-188. alhaique f. & tagliacozzo a. (2000) l’interpretazione dei dati faunistici nella ricostruzione delle strategie di sussistenza nel paleolitico medio: l’esempio del lazio. in: atti 2° conv. naz. archeozoologia, abaco, forlì, pp. 111-124. amori g., battisti c. & de felici s. (2009) i mammiferi della provincia di roma. dallo stato delle conoscenze alla gestione e conservazione delle specie. prov.roma, stilgrafica, roma, 350 pp. argenti p., kotsakis t. & sabatini f. (2008) myotis dasycneme in a latest pleistocene bat assemblage of cittareale cave (rieti, latium, central italy). geol. romana, 41, pp. 117-123. bartolomei g. & pasa a. (1980) analisi della fauna. in: g. bartolomei, l. cattani, m. cremaschi, a. pasa, c. peretto & a. sartorelli (eds), il riparo mezzena (stratigrafia del deposito, sedimenti,, pollini, faune, industrie). mem. mus. civ. st. nat. verona, ii, sez. sci. uomo, 2, pp. 13-16. benda p., ivanova t., horáček i., hanák v., červený j., gaisler j., gueorguieva a., petrov a. & vohralík v. (2003) bats (mammalia: chiroptera) of the eastern mediterranean. part 3. review of bat distribution in bulgaria. acta soc. zool. bohem., 67, pp. 245-357. blant m., moretti m. & tinner w. (2008) fréquence de quelques chiroptères durant l’holocène. geogr. helv., 63 (3), pp. 188-192. caloi l. & palombo m.r. (1989) la mammalofauna würmiana di grotta barbara (monte circeo): implicazioni paleoeconomiche e paleoambientali. hystrix, n. ser., 1, pp. 85-94. esu d., galdenzi s. & kotsakis t. (1990) molluschi e microvertebrati nel deposito pleistocenico della grotta del vento (gola della rossa ancona). nota preliminare. mem. soc. ital. speleol., ser. ii, 4, pp. 193-198. fahlke j.m. (2009) der austausch der terrestrischen säugetierfauna an der pleistozän/holozän-grenze in mitteleuropa. phd thesis, universität rheinischen friedrich-wilhelms, bonn. hanák v. & horàček i. (1986) zur südgrenze des areals von eptesicus nilssoni (chiroptera: vespertilionidae). ann. naturhist. mus. wien, 88/89, pp. 377-388. horáček i. (1995). k formování středoevropské netopýří fauny. netopiere, 1, pp. 93-98, bratislava. horàček i. & hanák v. (1989) distributional status of myotis dasycneme. in: hanák v., horàček i. & gaisler j. (eds.), european bat research 1987, charles university press, praha, pp. 565-590. horáček i., hanák v. & gaisler j. (2000) bats of the palearctic region: a taxonomic and biogeographic review. in: wołoszyn b.w. (ed.) proceedings of theviiith ebrs, 1, kraków, pp. 11-157. kotsakis t. (1991) late pleistocene fossil microvertebrates of grotta breuil (monte circeo, central italy). quat. nova, 1, pp. 325-332. kowalski k. (1990) some problems of the taphonomy of small mammals. in: fejfar o. & heinrich h.d. (eds.), internat. symp. evol., phylog. . biostratigr. arvicolids (rodentia, mammalia), geological survey, praha, pp. 285-296. kowalski k. (1995) taphonomy of bats (chiroptera). geobios, mém. spéc., 18, pp. 251-256. lanza b. & agnelli p. (2002) chirotteri, chiroptera blumenbach, 1779. in: spagnesi m. & de marinis a.m. (eds.), mammiferi d’italia. quad. conserv. natura, 14, min. ambiente ist. naz. fauna selvatica, pp. 44-142. marsico a. (2003) il disturbo arrecato alle comunità di chirotteri dalla fruizione delle grotte. thalassia salentina, 26 (suppl), pp. 277-284. miller g.s. (1912) catalogue of the mammals of western europe (europe exclusive of russia). british museum (nat. hist.), london, 1019 pp. mussi m., gioia p. & negrino f. (2006) ten small sites: the diversity of the italian aurignacian in: o. bar-yosef & j. zilhão (eds.), towards a definition of the aurignacian. trabalhos de arqueologia, 45, pp. 189-209. ochman k. (2003) late pleistocene and holocene bats (chiroptera) from the komarowa cave (cracowczestochowa upland, poland), preliminary results. acta zool. cracov., 46, pp. 73-84. ochman k. & wołoszyn b.w. (2003) bats (chiroptera). in: valde-nowak p., nadachowski a. & madeyska t. (eds.), obłazowa cave. human activity, stratigraphy and palaeoenvironment, inst. archaeol. ethnol. polish acad. sci., kraków, pp. 118-125. pasa a. (1953) primi risultati dell’indagine paleontologica sui materiali scavati nelle grotte di s. cassiano (colli berici vicenza). ann. univ. ferrara, sc. geol. pal., 1, pp. 169-183. piksa k. & wołoszyn b. w. (2001) postglacial bat remains from the polish tatra caves. lynx (praha), n. ser., 32, pp. 301-311. popov v.v. (2000) the small mammals (mammalia: insectivora, chiroptera, lagomorpha, rodentia) from cave 16 (north bulgaria) and the paleoenvironmental changes during the late pleistocene. in: b. ginter, j.k.kozłowski & l. laville (eds.), temnata cave. excavation in karlukovo karst area, bulgaria, jagellonian university press, kraców, pp. 159-240. postawa t. (2004) changes in bat fauna during the middle and late holocene as exemplified by thalate pleistocene and holocene bats of latium (central italy) 129 natocoenoses dated with 14c ams from krakówczęstochova upland caves, poland. acta chiropt., 6, pp. 269-292. radmilli a.m. (1974) gli scavi nella grotta polesini a ponte lucano di tivoli e la più antica arte nel lazio. sansoni, firenze, 131 pp. rolfo m.f., salari l. & zarattini a. (2009) nota preliminare sulle indagini archeologiche presso la grotta “mora di cavorso” (jenne, roma). in: g. ghini (ed.), lazio e sabina, scoperte scavi e ricerche, 5. atti quinto incontro studi lazio sabina, l’erma di bretschneider, roma, pp. 15-22. rolfo m.f., mancini d., salari l. & zarattini a. (2010) la grotta di “mora cavorso” (jenne, roma): nuove ricerche. in: g. ghini (ed.), lazio e sabina, 6. atti sesto incontro studi lazio sabina, quasar, roma, pp. 11-17. rossina v.v. (2006) bats as an indicator of human activity in the paleolithic, using the example of denisova cave, northwestern altai. paleont. j., 40, suppl. 4, pp. 5494-5500. ruedi m., walter s., fischer m.c., scaravelli d., excoffier l. & heckel g. (2008) italy as a major ice age refuge area for the bat myotis myotis (chiroptera: vespertilionidae) in europe. molecular ecol., 17, pp. 1801-1814. rydell j. (1993) eptesicus nilssonii (keyserling and blasius, 1939). mammalian species, 430, pp. 1-7. rydell j., strann k.b. & speakman j.r. (1994) first record of breeding bats above the arctic circle: northern bats at 68-70 °n in norway. j. zool. (london), 233, pp. 335-339. salari, l. (2010) lateglacial bats from the “m” layers of the arene candide cave (liguria, italy). riv. ital. paleont. strat., 116, pp. 119-138. salari l. & di canzio e. (2009) i chirotteri del pleistocene superiore e olocene antico di alcune grotte dell’italia centro-meridionale. boll. mus. civ. st. nat. verona, geol.-paleont.-preist., 33, pp. 3-25. salari l., passacantando d. & rolfo m.f. (2010) first data on the latest pleistocene mammals from mora cavorso cave (jenne, latium, central italy). il quaternario, this volume. schwarcz h.p., buhay w., grün r., stiner m., kuhn s. & miller g.h. (1991) absolute dating of sites in coastal lazio. quat. nova, 1, pp. 51-67. sevilla garcía p. (1988) estudio paleontologico de los quirópteros del cuaternario español. paleont. i evol., 22, pp. 113-233. simmons n.b. (2005) order chiroptera. in: wilson d.e. & reeder d.a.m. (eds.), mammal species of the world, 3rd ed., the john hopkins university press, vol. 1, pp. 312-529. sommer, r. & nadachowski, a. (2006) glacial refugia of mammals in europe: evidence from fossil records. mamm. rev., 36, pp. 251-266. stewart j.r. & lister a.m. (2001) cryptic northern refugia and the origins of the modern biota. trends ecol. evol., 16, pp. 608-613. tata c. & kotsakis t. (2005) italian fossil chiropteran assemblages: a preliminary report. geo.alp, 2, pp. 53-60. tozzi c. (1970) la grotta di s. agostino (gaeta). riv. sci. preist., 25, pp. 3-87. tříska p. (2009) mammalian glacial refugia in europe. bachelor thesis, masaryk university, brno. wołoszyn b.w. (1987) pliocene and pleistocene bats of poland. acta palaeont. pol., 32, pp. 207-325. zhuowei t. & kotsakis t. (2008) tardiglacial micromammals of riparo salvini (latium, central italy). geol. romana, 41, pp. 125-132. ms. ricevuto il 13/10/2010 testo definitivo ricevuto il18/01/2011 ms. received: october 13, 2010 final text received: january 18, 2011 sess 1_160211.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 sea level changes and vertical movements of the land in the mediterranean region from integrated data marco anzidei1, 2, fabrizio antonioli3, kurt lambeck4, dorit sivan5, mohamed soussi6, enrico serpelloni7, silvia pondrelli7, gianfranco vannucci7, paolo baldi8, rita auriemma9, alessandra benini10 & emanuela solinas11 (1) istituto nazionale di geofisica e vulcanologia, rome, italy (2)università della calabria, dipartimento di fisica, cosenza, italy (3) enea, casaccia, rome, italy (4) research school of earth sciences, the australian national university, canberra 0200, australia (5) university of el manar, faculty of sciences of tunis, department of geology, tunisia (6) university of el manar, faculty of sciences of tunis, department of geology, tunisia (7) istituto nazionale di geofisica e vulcanologia,bologna, italy (8) università di bologna, dipartimento di fisica, bologna, italy (9) dipartimento beni culturali, universita` degli studi di lecce, lecce, italy (10) università della calabria, dipartimento di archeologia e storia delle arti, cosenza, italy (11) civico museo archeologico sa domu nosta, cagliari, italy corresponding author: m. anzidei <marco.anzidei@ingv.it> abstract: anzidei m. et al., sea level changes and vertical movements of the land in the mediterranean region from integrated data. (it issn 0394-3356, 2011) riassunto: anzidei m. et al., variazioni del livello marino e movimenti verticali della terra nell’area mediterranea da dati integrati. (it issn 0394-3356, 2011) key words: mediterranean, sea level, archeology, geodesy, geophysics parole chiave: mediterraneo, livello del mare, archeologia, geodesia, geofisica coastal settlements and maritime installations built in antiquity provide important insights into sea-level changes during past millennia, and reconstructions of historical sea-level change using archaeological coastal sites are particularly effective in the mediterranean sea, whose coastlines still preserve remnants of human activity since the last glacial maximum. the first pioneering results on sea level changes from archaeological indicators in the mediterranean were published during the ‘70s (flemming, 1969; caputo & pieri, 1976; schmiedt, 1974; pirazzoli, 1976; flemming & webb, 1986), but new and more detailed results arise for the mediterranean during the last decade (antonioli et al., 2007; lambeck et al., 2010a & references therein; lambeck et al., 2010b; anzidei et al., 2010a; anzidei et al., 2010b;). unfortunately, despite the large number of archaeological remains in the mediterranean, only a part of them can be used to obtain reliable information on their former relationship to sea level (auriemma & solinas, 2009). limitations arise as a result of their uncertain use, poor preservation, or because they were built in geologically unstable areas which produce local disturbances. although the oldest known archaeological site useful to constraints the sea-level change in the mediterranean (lambeck & purcell, 2005) starts with the 22 ka flooded paintings of cosquer cave (southern france) today 37 m below sea level (clottes et al., 1997), particularly valuable are the roman age coastal sites. fish tanks, piers and harbors constructions, generally dated between the 1st century bc and the 1st century ad, are very precise indicators (lambeck et al., 2004b). quarries carved along the coastlines and located nearby fish tanks and harbors or villas of similar age, can provide additional data on past water level, as well as information on their elevation above sea level, although these alone are less precise indicators. we provide a data base of coastal archaeological sites with valid records dated back to 1.6-2.5 ka bp, using direct observations as well as archaeological, geophysical and geological literature. particular attention was given to the elevation of the significant architectural features related with the sea level. these include the system of channels of the fish tanks, bollard and piers for harbors, lower cuttings for quarries, bottom end of slipways. in addition to those artifacts which provide precise data, other features can be classified as to whether they must have been dry (house pavements, roads, tombs), 14 16 15 partially in the water (piers, quays, moles, slipways, fish tanks), or completely submerged (floor of channels for water exchange in the fish tanks, floor of fish tanks, channels at the entrance of harbors, floor of harbors). when different class of structures exist at a single site, as for example at ventotene island (italy), we can obtain a very accurate estimation of the relative sea level change as well as understand the relationships between their elevations with respect to the mean sea level at the time of their construction. moreover, structures from different ages can provide a relative sea level curve for that specific site. to obtain precise measurements of the relative sea level change at the archaeological sites, we defined the “functional elevation” as the elevation of specific architectural parts of an archaeological structure with respect to the local mean sea level at that location and at the time of its construction. it depends on the type of structure, its use and the local tide amplitudes. the minimum elevation of particular structures above the local highest tides can also be defined. field data from more than 150 sites of valid archaeological markers were used in our study. field measurements were performed by invar rod, optical or electronic methods, during calm sea with null wave action. elevations are related to the sealevel position at that moment. data accuracy with their uncertainties for age and elevation at each site, are estimated on the basis of the type of indicator used and of the historical literature, based on the artifacts or on the architectural features. observations of geomorphological indicators, such as beachrocks and solution notches, are used to integrate and reinforce the archaeological interpretations as in antonioli et al. (2007). the use of these structures, their age and conservation, the accuracy of the survey and the estimation of the functional heights were all used in considering the observational uncertainties at each site. accuracy of the elevations of the data set is within 0.5-0.2 m, although some limitations occurs, as for quarries or slipways, which are less precise indicators in comparison with fish tanks (lambeck et al., 2004b). the analysis was performed during four different steps: 1) the elevation of the valid sites were measured (average value of multiple measurements of the best preserved parts of the investigated structures) with respect to the sea level at the time of surveys; 2) measurements were reduced to mean sea level of the site itself, applying tidal corrections at the surveyed sites, using the data of the nearby tide gauges (www.idromare.it; www.psmsl.ac.uk). in the cases of the unavailability of tide gauge data were we used the predicted tide estimation, corrected for local pressure values. we estimate errors for the elevations and ages of the archaeological markers and evaluate their functional elevations on the basis of archaeological interpretations. since the investigated archaeological structures were originally used year round, we assume that the defining levels correspond to the annual mean conditions at the time of construction. age errors are estimated from the architectural features and historical documents, while elevation errors derive from the measurements of the functional heights (for example, the lower limiting values for the quarries and slipways); 4) finally, we examined the predicted and observed sea levels, by comparing the current elevations of the markers (i.e. the relative sea-level change at each location) with the sea-level elevation predicted by the proposed glacio-hydro-isostatic model for each location. we hypothesize tectonic stability at the sites where the elevations of the markers are in agreement with the predicted sea-level curve. conversely, we hypothesize that the area has experienced tectonic or volcanic subsidence or uplift when the elevations of the markers are below or above that of the predicted sea-level curve, respectively. the archaeological evidences is providing a new picture of the spatial distribution of the sea level changes in mediterranean since the last ~2.3 ka. despite the limitations and resolution of the available data with respect to the known tectonic complexity of the study region, an integrated use of historical data, geological observations of the elevation of mis 5.5, instrumental data of tide gauges and vertical gps can provide, together with an accurate modelling of the glacio-hydroisostatic contribution for vertical land movements and amount of water in the basin, to a more comprehensive description of the causes that are driving the sea level change since ~2.5 ka and their current rates at different locations, as reported in ferranti et al., 2010. we use the calibrated model results to separate out the tectonic contribution, widely diffused in the mediterranean, from the vertical movements related to the glacio–hydro-isostatic changes. our analysis are consistent with model predictions as well as trends inferred from seismic strain analysis of earthquakes occurred during the last 30-40 years and tide gauge data for the last ~100 yr. this indicates that besides the glacio–hydro-isostatic effect, also the tectonic contribution can affects the relative sea level changes along the coastlines of the mediterranean, since the last ~2.5 ka. sea level changes and vertical movements of the land ... 16 ms. received: testo ricevuto il references antonioli f., anzidei, m. auriemma, r., gaddi d., furlani s., lambeck k., orrù p., solinas e., gaspari a., karinja s.,kovačić v. & surace l. (2007) sea level change during holocene from sardinia and northeastern adriatic (central mediterranean sea) from archaeological and geomorphological data. quat. sc. rev., 26, 2463 –2486. anzidei m., antonioli f., benini a., lambeck k., sivan d., serpelloni e. & stocchi p. (2010) sea level change and vertical land movements since the last two millennia along the coasts of southwestern turkey and israel. quat. int., 10.1016/j.quaint.2010.05.005 anzidei m., antonioli f., lambeck k., benini a., soussi m. & lakhdar r. (2010) new insights on the relative sea level change during holocene along the coasts of tunisia and western libya from archaeological and geomorphological markers. doi:10.1016/j.quaint.2010.03.018. auriemma r. & solinas e. (2009) archaeological remains as sea level change markers: a review. quat. int. 206, 134-146. caputo m. & pieri l.(1976) eustatic variation in the last 2000 years in the mediterranean. j. geophys.res. 81, 5787– 5790. clottes j., courtin j., collina-girard j., arnold m. & valladas h. (1997) news from cosquer cave: climatic studies recording, sampling, dates. antiquity 71, 321-326. ferranti l., fabrizio a., anzidei m., monaco c. & stocchi p. (2010) the timescale and spatial extent of vertical tectonic motions in italy: insights from relative sea-level changes studies. http:// virtualexplorer.com.au/article/2009/255/verticaltectonic-motions-in-italy flemming n.c. (1969) archaeological evidence for eustatic changes of sea level and earth movements in the western mediterranean in the last 2000 years. geol. soc. am., sp. paper 109. flemming n.c. & webb c.o.(1986) tectonic and eustatic coastal changes during the last 10,000 years derived from archaeological data. z. geomorphol. n.f., 62, 1 –29. lambeck k., anzidei m., antonioli f., benini a. & esposito e. (2004b) sea level in roman time in the central mediterranean and implications for modern sea level rise. earth planet. sc. lett., 224, 563-575. lambeck k. & purcell a. (2005) sea-level change in the mediterranean sea since the lgm: model predictions for tectonically stable areas. quat. sc. rev. 24, 1969–1988. lambeck k., woodroffe c.d., anzidei m., antonioli f., gehrels w.r., van de plassche o. & wright a.j. (2010) palaeoenvironmental records, geophysical model l ing and reconstruction of sea-level trends and variability on centennial and longer time scales. in church j.a., woodworth p.l., aarup t., wilson w.s. eds. “understanding sea-level rise and variability”. blackwell publishing, london. lambeck k., antonioli f., anzidei m., ferranti l., leoni g., scicchitano g. & silenzi s. (2010). sea level change along the italian coast during the holocene and projections for the future. quat. int. doi:10.1016/j.quaint.2010.04.026 pirazzoli p.a. (1976) sea level variations in the northwest mediterranean during roman times. science 194, 519– 521. schmiedt g. (1974) il livello antico del mar tirreno. testimonianze da resti archeologici. e. olschki eds., firenze, 323 pp. m. anzidei et al. january 14, 2011 14 gennaio 2011 base early pleistocene distal pyroclastic-fallout material in continental and marine deposits of western umbria (italy): chemical composition, provenance and correlation potential roberto bizzarri, angela baldanza, maurizio petrelli, federico famiani & angelo peccerillo dipartimento di scienze della terra, università di perugia corresponding author: r. bizzarri, <roberto.bizzarri@libero.it> abstract: bizzarri r. et al., early pleistocene distal pyroclastic-fallout material in continental and marine deposits of western umbria (italy): chemical composition, provenance and correlation potential. (it issn 0394-3356, 2010). distal pyroclastic fallout material has been recently documented in the orvieto area (umbria, central italy), within early pleistocene continental and marine deposits. due to the age constrains, the association with middle pleistocene “paleobolsena” volcanic events can be excluded. in order to individuate a possible provenance, the laser ablation – inductively coupled plasma – mass spectrometry (la-icp-ms) analytical procedure has been carried out. the procedure has been tested on pumice lapilli (2-5 mm) and glass inclusions contained in idiomorphic clinopyroxene crystals, both coming from the early pleistocene conglomerate of the il caio section. the study is still in progress: some preliminary results are here proposed. data on melt inclusions seem to be more reliable than data on pumice fragments for the purpose of recognising pristine magmatic compositions of pyroclastic material and to achieve information on the provenance of volcanic clasts. nevertheless, both data suggest the affinity with the roman comagmatic provence. since crystal fragments with melt inclusions are common in many distal fallout deposits, the la-icp-ms protocol presented here can be of general application to tephrochronology and volcanological studies. together with the biostratigraphic record, indeed, the procedure looks promising as a tool for stratigraphic correlations and geodynamic reconstructions. riassunto: bizzarri r. et al., depositi piroclastici da caduta nei depositi marini e continentali del pleistocene inferiore in umbria occidentale (italia): composizione chimica, provenienza e potenzialità di correlazione. (it issn 0394-3356, 2010). depositi piroclastici da caduta sono stati recentemente segnalati nell’area orvietana (umbria, italia centrale), in depositi sia marini che continentali datati al pleistocene inferiore. su base biostratigrafica sembra da escludere la correlazione con gli eventi esplosivi del pleistocene medio riferibili al “paleobolsena”. per individuarne la provenienza, è stata impostata la procedura analitica la-icp-ms, testata in via preliminare sia su lapilli pomicei che su inclusioni vetrose, contenute all’interno di cristalli idiomorfi di clinopirosseno, provenienti dai conglomerati del pleistocene inferiore della sezione de il caio. lo studio è ancora in corso; proponiamo qui alcuni risultati preliminari. i dati delle inclusioni vetrose sembrano più attendibili rispetto alle pomici ai fini della ricostruzione della composizione primaria del magma e della provenienza dei clasti vulcanici. nonostante ciò, entrambi i dati suggeriscono un’affinità dei materiali analizzati con le rocce della provincia comagmatica romana. poiché cristalli con inclusioni vetrose sono comuni in molti depositi da caduta, l’analisi la-icp-ms può essere di applicazione generale negli studi tefrocronologici e vulcanologici. associata all’analisi biostratigrafica, la procedura appare uno strumento promettente per le correlazioni stratigrafiche e le ricostruzioni geodinamiche. keywords: pyroclastic deposits, la-icp-ms, melt inclusions, tephrochronology, early pleistocene, central italy. parole chiave: depositi piroclastici, la-icp-ms, inclusioni fluide, tefrocronologia, pleistocene inferiore, italia centrale. il quaternario italian journal of quaternary sciences 23(2), 2010 245-250 1. aims and methods rapid, precise and reliable major and trace element composition of distal pyroclastic material is critical in tephrochronological and volcanological studies. investigation on ashes and pumice fragments is generally used for these purposes. distal pyroclastic fallout material has been recently documented in the orvieto area (umbria, central italy: (fig. 1a)), in both continental and marine deposits, biostratigraphically referred to the early pleistocene (bizzarri et al., 2003; bizzarri, 2006; famiani, 2010). these deposits bearing distal pyroclastic fallout material crop out on a 10-20 km wide area around the orvieto town. particularly, five sections are here considered: il caio section, camorena section, padella section, sugano well and the small outcrop of f.so aiuole. most of the volcanic material is represented by leucite-bearing pumice clasts and idiomorphic pyroxene crystals (fig. 1b); although volcanic materials are included in sedimentary deposits, they lack clear reworking evidences. the idiomorphic pyroxene crystals range among 0.5 and 10 mm, show a preserved habitus, and can be related to a local source, probably represented by a small, still unknown volcanic vent in 10 to 20 km radium, whose activity, presumably intermittent, covered a time span of at least 300 ky (mnn 19 b-d nannofossil zones). the age constrains permit us to exclude a correlation to middle pleistocene “paleobolsena” volcanic events. in order to determine magma composition (major and trace elements) of distal pyroclastic material, and to individuate its possible provenance, the laser ablation – inductively coupled plasma – mass spectrometry (la-icp-ms) analytical protocol has been carried out, by coupled 246 r bizzarri et al. investigation of pumice clasts and glass inclusions trapped in minerals. the procedure has been tested on pumice lapilli (2-5 mm in diameter) and microscopic glass inclusions contained in single idiomorphic clinopyroxene crystals (2-10 mm), both coming from the il caio section (figs. 1b, 2). la-icp-ms analysis on pumice clasts has been carried out on glass beads obtained by the melting of small amounts of rock powder. a few mg of pumice is sufficient for a complete major and trace element analysis, which allows us to study extremely small samples, typical of distal fallout deposits. la-icp-ms analysis of glass inclusions is carried out in situ; an inclusion of at least 50 µm is sufficient to determine a complete set of major and trace elements. the capability of the la-icp-ms instrumentation to perform spatially resolved and whole rock trace element analysis is largely assessed in the literature (e.g. longerich et al., 1996; günther et al., 1997, 1999; norman et al. 1998; durrant 1999; eggins, 2003; petrelli et al., 2007, 2008). 2. geological setting and biostratigraphic constrains the five study sections (figs. 1a, 1c) belong to the paglia valley, a nw-se oriented half-graben, which accommodated a coastal marine environment from early pliocene to early pleistocene (ambrosetti et al., 1987; bizzarri et al., 2003; mancini et al., 2004; bizzarri, 2006). the camorena and sugano well sections document a clayey, marine offshore sedimentation, whereas the aiuole and padella sections mainly represent a sandy lower shoreface marine environment (figs. 1a, 1c). nannofossil assemblages allow to recognize four biostratigraphic events (bmg, tcm, blg, tlg, sensu raffi, 2002: fig. 1c) and to assign to deposits a time range comprised between ~1.9 and ~1.1 ma (mnn 19a to e nannofossil subzones). three horizons, enriched in volcanoclastic materials (mainly pumice fragments and idiomorphic pyroxene crystals), have been documented (fig. 1c). on the other hand, the il caio section (fig. 1c) figure 1 a) schematic sketch of the area and location of studied sections: 1=il caio, 2=padella, 3=aiuole, 4=camorena, 5=sugano well. extension of main volcanic districts products (vulsini, cimini, vico and sabatini mountains) is also reported. b) remote fallout analyzed materials: melt inclusions-bearing pyroxenes and leucite-rich pumices. c) biostratigraphic correlation of studied sections and volcanic events: bmg=medium gephyrocapsa fo, tcm= c. macintyrei lo, blg large gephyrocapsa fo, tlg= large gephyrocapsa lo. a) schema semplificato dell’area e ubicazione delle sezioni studiate: 1=il caio, 2=padella, 3=aiuole, 4=camorena, 5=sugano well. viene riportata anche l’estensione dei prodotti correlati ai principali distretti vulcanici (vulsini, cimini, vico e sabatini) presenti nell’area. b) aspetto dei depositi piroclastici analizzati (pirosseni con inclusioni vetrose e pomici a leucite). c) correlazione biostratigrafica delle sezioni studiate e degli eventi vulcanici: bmg=medium gephyrocapsa fo, tcm= c. macintyrei lo, blg large gephyrocapsa fo, tlg= large gephyrocapsa lo. consists in a lower portion (~23m) of shallow marine deposits and an upper part (~6m) characterized by continental alluvial fan deposits (bizzarri et al., 2003). the alluvial-fan deposits contain, dispersed within sedimentary clasts, small fragments of pyroclastic materials including pumices and clinopyroxenes. nevertheless, an idiomorphic pyroxenes-rich horizon has also been documented inside the marine deposits (fig. 1c). calcareous nannoplankton assemblages with gephyrocapsa oceanica s.l. (3.5-4 µm), calcidiscus macintyrei, helicosphaera sellii, coccolithus pelagicus, referable to early pleistocene (mnn 19a and 19b sub247early pleistocene distal pyroclastic-fallout ... zones: raffi, 2002) fix the lower limit of the section to ~1.90 ma, and the top of marine deposits to ~1.62 ma. the bmg event (sensu raffi, 2002), dating ~1.75 ma has also been documented. in addition, late villafranchian freshwater mollusc assemblage (bizzarri et al., 2003), collected in alluvial-fan deposits, point to an age not higher than 1.4 ma for the section’s top. as a consequence, the age of v2 and v1 horizons (fig. 1c) is comprised between 1.4 ma and 1.62 ma, and between 1.75 and 1.62 ma, respectively. analogous age constrains characterize the other four outcrops (fig. 1c). distal fallout deposits, documented in the five figure 2 variation diagrams of representative major and trace elements against mgo for melt inclusions hosted in pyroxene phases and pumice samples prepared as fusion beads. diagrammi di variazione dei più rappresentativi elementi maggiori e in tracce vs mgo, per le inclusioni fluide nei pirosseni e i campioni di pomici (perle di fusione). 248 sections, cover a time span of about 300 ky, from ~1.75 to ~1.4 ma (mnn 19 b-d nannofossil zones), and biostratigraphic constrains confirm the occurrence of three successive steps in volcanic activity (v1, v2, v3 volcanoclastic horizons: fig. 1c). the v1 horizon is documented in marine deposits on the il caio and padella sections and occurs in the mnn 19b zone (~1.75 to 1.62 ma). the main volcanoclastic horizon (v2) is recognizable in the il caio, padella and camorena sections, in the sugano well, and dates to 1.62-1.5 ma (mnn 19c zone). the v3 horizon (camorena section, f.so aiuole outcrop) is biostratigraphically constrained at ~1.50 ma (mnn 19d zone). 3. analyses on il caio volcanoclastic deposits the volcanic fragments coming from alluvial-fan deposits in the uppermost part of the il caio section has been selected as a reference to test the described analytic protocol, due to their abundance and the grade of preservation, in spite of the high-energy sedimentary environment, as well as for their major dimensions in respect to fragments collected in the other sites. on the other hand, this section has been formerly described both on its sedimentary, stratigraphic and geochemicalpetrologic features (bizzarri et al., 2003). data obtained on melt inclusions, glass beads of pumices are shown as variation diagrams of major and trace elements against mgo (fig. 2), as spider diagrams (fig. 3), and as incompatible trace element ratios (fig. 4). analyses of pumice samples are shifted to higher cao and sio2 than data on melt inclusions (fig. 2) and there is an overall higher concentration of k2o, rb, pb, u, in the melt inclusions than in the pumice samples (fig. 2). na2o is much higher and more scattered in the pumice samples than in the melt inclusions. differences for sio2 and cao between pumice samples and melt inclusions are likely related to the presence of cpx phenocryst in the pumice clasts. cpx compositions reported on the harker diagrams show, in fact, continuity with compositions of pumice samples, suggesting some effect of mineral composition on pumice major elements (see arrows in fig. 2). it must be reminded that pumice clasts have a small size and also a single cpx phenocryst may have strong effects on major element chemistry, shifting pumice compositions toward those of the mineral phase. this can also be responsible for narrower ranges of incompatible elements in pumice samples, since the presence of volumetrically significant cpx may passively decrease abundances of elements that are not hosted by cpx. low concentrations of k2o and rb in pumices, along with the large scattering and high concentrations of na2o likely reflect secondary alteration processes. in particular leucite is completely transformed into analcite. lower pb and u contents of pumices than glass inclusions are also likely due to secondary alteration processes of the groundmass, since these two elements are mobile during deuteric processes. note that those elements that are poorly mobile during secondary processes (e.g., ree, nb, ta, zr, th etc.; fig. 3) show similar ranges of abundances and ratios (fig. 4 a) in both pumices figure 3 (a, b) ree patterns of melt inclusions hosted in pyroxene phases (a) and pumice samples (b); (c, d) incompatible element patterns normalized to primordial mantle composition for melt inclusions and cpx (c) and pumice samples (d). (a, b) diagrammi ree delle inclusioni fluide all’interno dei pirosseni (a) e delle pomici (b); (c, d) andamento degli elementi incompatibili normalizzati alla composizione del mantello primordiale per le inclusioni fluide (c) e le pomici (d). r bizzarri et al. 249 and melt inclusions. overall, the data suggest a strong role of secondary processes in modifying pumice compositions. in contrast, melt inclusions do not appear to be affected by secondary processes. elements that are immobile during secondary processes (e.g. ree, nb, ta, zr, th, etc.) show similar range of compositions and element ratios in pumice and melt inclusions (figs. 3, 4). the ultrapotassic affinity of the investigated pumice samples and melt inclusion is obvious. their affinity with magmas of the roman province is suggested by both the petrography of the pumice clasts and by major and trace element geochemistry of pumice and melt inclusions (peccerillo, 2005). all samples are silica undersatured, ree patterns for both melt inclusions and pumice are fractionated with lree progressively enriched with respect to hree (figs. 3a, 3b). most samples display a small negative eu anomaly. ree patterns do not evidence any difference between pumice samples and melt inclusion supporting the idea that ree were relatively immobile during alteration processes. similar ree patterns are observed in the ultrapotassic rocks of central italy (peccerillo, 2005). however, small negative ce anomalies are common in the pumice samples, but not in the melt inclusions and the roman magmas. data on pumice samples reveal high concentrations of incompatible elements, especially some large ion lithophile elements (lile: ba, th, u, lree, pb), and relatively low concentrations of high field strength elements (hfse: ta, nb, hf, zr, ti) resembling ultrapotassic rocks (i.e. tephrite to phonolite) from the roman volcanoes. however, some elements such as rb, pb and k are depleted in pumice samples whereas others (e.g. na2o) are enriched, likely due to secondary processes (figs. 3c, 3d). data on melt inclusions entrapped in clinopyroxene crystals reveal a narrower range of compositions than pumice samples for several major and trace elements. trace element distribution reveals high enrichments for all lile, including k, rb and pb, and low hfse, matching more closely roman ultrapotassic magmas. ratios of immobile trace elements (e.g. nb/zr, th/ta, etc.) are similar in pumice clasts and the glass inclusions, and both fall in the field of roman volcanic rocks (fig. 4a). other ratios involving mobile elements (e.g. ce/sr, pb/ta, ce/pb, th/u, k/na) are very different in the pumice samples with respect to melt inclusions, the latter falling within the field of roman volcanics (figs. 4b, 4c). 4. concluding remarks the study is still in progress. since crystal fragments with melt inclusions are common in many distal fallout deposits, the proposed la-icp-ms protocol on melt inclusions can be of general application to tephrochronology and volcanological studies. the application to the fall out material included in the il caio early pleistocene section clearly shows that pumice fragments are affected by secondary processes but not melt inclusions. therefore data on melt inclusions seem to be more reliable than data on pumices for the purpose of recognising pristine magmatic compositions of pyroclastic material and to achieve information on the provenance of volcanic clasts. elements that are immobile during secondary processes (e.g. ree, nb, ta, zr, th etc.) show a similar range of compositions and element ratios in pumices and melt inclusions. all geochemical data, such as the ultrapotassic character, the silica undersatured signature, the progressive enrichment of lree with respect to hree, the high lile enrichments and high lile/hfse patterns, clearly define a strict affinity of il caio pyroclastic materials with magmas of the roman magmatic province (peccerillo, 2005). the next step will be to apply this procedure to figure 4 variation of trace element ratios in the plioquaternary rocks (mgo>4 wt.%) from the central italy area (from peccerillo, 2005) compared with caio melt-inclusions and pumice samples: (a) nb/zr vs th/ta; (b) ce/sr vs th/ta; (c) nb/zr vs pb/ta. see text for details. variazione degli elementi in tracce nelle rocce plio-quaternarie (mgo>4 wt.%) del centro italia comparata con le inclusioni fluide e le pomici del caio (da peccerillo, 2005): (a) nb/zr vs th/ta (b) ce/sr vs th/ta; (c) nb/zr vs pb/ta. ulteriori dettagli nel testo. early pleistocene distal pyroclastic-fallout ... 250 idiomorphic clinopyroxene crystals and/or pumice clasts collected in other sites, to test the real roman affinity for the camorena, sugano well, padella and f.so aiuole fallout deposits, in order to confirm their inferred biostratigraphic correlation. this first application of melt inclusion geochemical data in the study of pyroclastic fall out materials deposited in a sedimentary basin opens new perspectives in several fields: it could be useful to (a) better constrain the age (sedimentary section are generally well time constrained), (b) define the areal distribution of eruptions and, more in general, (c) reconstruct the evolution of the volcanism within the mediterranean area. together with the biostratigraphic record, indeed, the procedure looks promising as a tool for stratigraphic correlation and geodynamic reconstructions. references ambrosetti p., carboni m.g., conti m.a., esu d., girotti o., la monica g.b., landini b. & parisi g. (1987) il pliocene ed il pleistocene inferiore del bacino del fiume tevere nell'umbria meridionale. geogr. fis. dinam. quat., 10, pp. 10-33. bizzarri r. (2006) depositi plio-pleistocenici tra la val di chiana e il lago di corbara: caratterizzazione sedimentologica e ricostruzione paleoambientale. tesi di dottorato, università di perugia, aa 2005/2006, 408 pp. bizzarri r., ambrosetti p., argenti p., gatta g.d. & baldanza a. (2003) l’affioramento del caio (lago di corbara, orvieto, italia centrale) nell’ambito dell’evoluzione paleogeografica plio – pleistocenica della valle del tevere: evidenze sedimentologiche e stratigrafiche. il quaternario, 16 (2), pp. 241255. durrant s.f. (1999) laser ablation inductively coupled plasma-mass spectrometry: achievements, problems, prospects. journal of analytical atomic spectrometry, 14, pp. 1385-1403. egging s.m. (2003) laser ablation icp-ms analysis of geological materials prepared as lithium borate glasses. geostandards newsletter, 27, pp. 147162. famiani f. (2010) il quaternario marino del versante occidentale del monte peglia (umbria sud-occidentale): caratterizzazione sedimentologica e paleoecologica. tesi di laurea inedita, università di perugia, 154 p. günther d., frischknecht r., heinrich c.a. & kahlert h.j. (1997) capabilities of a 193 nm arf excimer laser for la-icp-ms micro analysis of geological materials . journal of analytical atomic spectrometry, 12, pp. 939-944. günther d., jackson s.e. and longerich h.p. (1999) laser ablation and ark/spark solid sample introduction into inductively coupled plasma mass spectrometers. spectrochimica acta, 54b, pp. 381-409. longerich h.p., jackson s.e. & günther d. (1996) laser ablation-inductively coupled plasma mass spectrometric transient signal data acquisition and analyte concentration calculation. journal of analytical atomic spectrometry, 11, pp. 899-904 mancini m., girotti o. & cavinato g.p. (2004) il pliocene ed il quaternario della media valle del tevere (appennino centrale). geol. romana, 37, pp. 175-236. norman m.d., griffin w.l., pearson n.j., garcia m.o. & o’reilly s.y. (1998) quantitative analysis of trace elements abundances in glasses and minerals: a comparison of laser ablation inductively coupled plasma mass spectrometry, solution inductively coupled plasma mass spectrometry, proton microprobe and electron microprobe data. journal of analytical atomic spectrometry, 13, pp. 477-482. peccerillo a. (2005) plio-quaternary volcanism in italy. petrology, geochemistry, geodynamics. springer, heidelberg, 365 pp. petrelli m., perugini d., alagna e., poli g. & peccerillo a. (2008) spatially resolved and bulk trace element analysis by laser ablation inductively coupled plasma mass spectrometry (la-icpms). accepted for publication on periodico di mineralogia. petrelli m., poli g., perugini d. & peccerillo a. (2007) graphite electrode lithium tetraborate fusion for trace element determination in bulk geological samples by laser ablation icp-ms. microchimica acta, doi 10.1007/s00604-006-0731-6. raffi i. (2002) revision of the early middle pleistocene calcareous nannofossil biochronology (1.75-0.85 ma). marine micropaleontology, 45, pp. 25-55. ms. ricevuto il 16 giugno 2010 testo definitivo ricevuto il 4 novembre 2010 ms. received: june 16, 2010 final text received: november 4, 2010 r bizzarri et al. plio-pleistocene deltaic deposits in the città della pieve area (western umbria, central italy): facies analysis and inferred relations with the south chiana valley fluvial deposits roberto bizzarri & angela baldanza dipartimento di scienze della terra, università degli studi di perugia, perugia (italy) e-mail: roberto.bizzarri@libero.it abstract: bizzarri r. & baldanza a., plio-pleistocene deltaic deposits in the città della pieve area (western umbria, central italy): facies analysis and inferred relations with the south chiana valley fluvial deposits. (it issn 0394-3356, 2009). the plio-pleistocene coastal marine deposits in the città della pieve area (western umbria, central italy) can be considered as a borderline among the paglia valley marine basin southward, and the south chiana valley and tavernelle-pietrafitta continental basins, northand eastward respectively. deposits, particularly on the città della pieve hill, have been traditionally referred to a deltaic environment and put in relation with river systems (paleo-tiber, paleo-nestore) draining the tavernelle-pietrafitta basin. moreover, previous authors considered the città della pieve lithostratigraphic succession as a reference scheme to reconstruct the evolution of western umbria marine environments during pliocene and pleistocene. new data allow a revaluation of the città della pieve stratigraphic succession, whereas sedimentological and stratigraphic analyses lead to both a detailed description and a deltaic depositional context attribution. at the same time, studies on coeval south chiana valley continental deposits suggest a depositional continuity with coastal marine deposits and, in spite of previous authors’ interpretations, a main northern (chiana valley) alimentation for the città della pieve deltaic system. riassunto: bizzarri r. & baldanza a., depositi deltizi plio-pleistocenici nell’area di città della pieve (umbria occidentale, italia centrale): analisi di facies e ricostruzione dei rapporti con i depositi fluviali della val di chiana. (it issn 0394-3356, 2009). i depositi marino costieri plio-pleistocenici, affioranti nell'area di città della pieve (umbria occidentale, italia centrale), fanno idealmente da confine tra il bacino marino della valle del paglia, a sud, e i bacini continentali della val di chiana meridionale e di tavernellepietrafitta, rispettivamente a nord e a est. tali depositi, in particolare nella collina di città della pieve, sono stati tradizionalmente riferiti a un ambiente deltizio e messi in relazione con i sistemi fluviali (paleo-tevere, paleo-nestore) che drenavano il bacino di tavernellepietrafitta. inoltre, gli autori precedenti hanno considerato la successione litostratigrafica di città della pieve come uno schema di riferimento per la ricostruzione dell’evoluzione paleoambientale dell’umbria occidentale durante il pliocene e il pleistocene. i nuovi dati stratigrafici hanno permesso una riconsiderazione della successione pievese. inoltre, l'analisi sedimentologica e stratigrafica ne ha consentito sia una descrizione dettagliata che l'attribuzione a un contesto deposizionale deltizio. gli studi parallelamente condotti su coevi depositi continentali della val di chiana meridionale hanno permesso di verificare la contiguità di ambienti deposizionali con l'area pievese e di suggerire, contrariamente a quanto proposto in letteratura, una prevalente alimentazione dalla val di chiana per l'apparato deltizio di città della pieve. keywords: river deposits; deltaic deposits; pliocene; pleistocene; umbria; tuscany. parole chiave: depositi fluviali; depositi deltizi; pliocene; pleistocene; umbria; toscana. il quaternario italian journal of quaternary sciences 22(2), 2009 127-138 1. introduction the main features of the plio-pleistocene c i t t à della pieve deltaic deposits and south c h i a n a v a l l e y gravel braided river deposits are here illustrated. the aim is to mark their sedimentological and petrographic affinity and the paleodepositional contiguity, as well as to propose a reliable depositional model. some resulting considerations on origin and provenance of the gravel are also proposed. since the end of 19t h century, the città della pieve area (western u m b r i a, central italy) has been considered as a key-zone to understanding plio-pleistocene paleoenvironmental evolution across the south c h i a n a valley (fig. 1a), particularly in the t r a s i m e n o lake area, and p a g l i a valley. deposits cropping out on the c i t t à della pieve hill have been traditionally referred to a deltaic environment and linked to the paleo-tiber (ve r r i, 1877; 1885; 1889; 1892; 1918; lo t t i, 1926; me r l a, 1944) or to the paleo-n e s t o r e river systems (am b r o s e t t i et al., 1977; 1987; 1989; ca t t u t o et al., 1983; 1992) draining the t a v e r n e l l e p i e t r a f i t t a basin (fig. 1). eastern alimentation, therefore, has been classically considered as prevailing, although some authors also hypothesized a subordinate northern provenance (ca t t u t o et al., 1992). north of città della pieve, the south chiana valley basin evolved as a river environment from middle-late pliocene to early pleistocene (ba r b e r i et al., 1994; ar u t a et al., 2004; 2006; bi z z a r r i, 2006; ba r c h i et al. , 2007; bizzarri et al., 2008), becoming a fluvial-lacustrine environment, with the early development of “paleot r a s i m e n o”, from middle pleistocene onward. on the other hand, ambrosetti et al. (1977; 1987; 1989) discussed the implications of the città della pieve lithostratigraphic succession and proposed a reference scheme for western umbria marine deposits (fig. 2), underlining the occurrence of two main depositional cycles: an early-middle pliocene cycle, made up of three superimposed units (“argille di fabro”, “sabbie a flabellip e c t e n” and “conglomerati di città della pieve”), cha128 r. bizzarri & a. baldanza racterized by an average north-east inclination of deposits, and an early pleistocene cycle, coinciding with the “argille e sabbie del chiani-tevere” unit, whose deposits are prevailing sub-horizontal. on the basis of geomorphologic data (orientation of main valleys, asymmetry on valley profiles, different altitude of river terraces), chiefly documented east and north-east of città della pieve, a strong structural and tectonic control on landscape evolution has been inferred (am b r o s e t t i et al. , 1989; ca t t u t o et al., 1983; 1992). according to stratigraphic data, previous authors individuate a main tectonic event corresponding to “acquatraversa” phase (late pliocene-early pleistocene: am b r o s e t t i et al., 1977; 1987; 1989; cattuto et al., 1983; 1992). most of the data collected during the last few years (bi z z a r r i, 2006; bi z z a r r i & ba l d a n z a, 2007) can hardly be included into the former scenario; thus, a revaluation of supply origin, as well as of paleodepositional and stratigraphic implications for the città della pieve succession, seems to be appropriate. figure 1 a) geographic location of study area and main geological and depositional domains. b) simplified geological map for study area (detail). a) alluvial deposits (holocene); b) "paleotrasimeno" fluvial and lacustrine deposits (middle-late pleistocene); c) ancient chiana valley piedmont deposits (early pleistocene); d ) t a v e r n e l l e p i e t r a f i t t a basin piedmont and fluvial-lacustrine deposits (early pleistocene); e ) c h i a n a valley sandy braided river deposits (early pleistocene); f ) c h i a n a valley gravel braided river deposits (late pliocene-early pleistocene); g) città della pieve deltaic deposits (late pliocene-early pleistocene); h ) brackish-transitional deposits (late pliocene-early pleistocene); i ) macigno s.l. (oligocene-miocene); l) scaglia toscana s.l. (cretaceous-eocene); m ) l i g u r i d s (cretaceous-palaeocene); n) main extension faults; o) faults (presumed); p) main thrusts; q) main rivers; r) geological profile tract; s) sub-horizontal strata; t) 5° to 10° dipping strata; u) main outcrops: 1) frazzi brickyard, 2) cdp1, 3) cdp2, 4) cdp3, 5) cdp4, 6) cdp5, 7) cdp6, 8) cdp7, 9) cdp8, 10) p.gio al piano, 11) s. biagio, 12) casaltoldo, 13) p.gio vaccaio, 14) le coste, 15) la trincea. a) collocazione geografica dell’area di studio e principali domini geologici e deposizionali. b) carta geologica semplificata (ingrandimento). a) depositi fluviali recenti (olocene); b) depositi fluvio-lacustri del "paleotrasimeno" (pleistocene medio-superiore); c) depositi pedemontani antichi della val di chiana (pleistocene inferiore); d) depositi pedemontani e fluvio-lacustri del bacino di tavernellepietrafitta (pleistocene inferiore); e) depositi di fiumi a canali intrecciati sabbiosi della val di chiana (pleistocene inferiore); f) depositi di fiumi a canali intrecciati ghiaiosi della val di chiana (pliocene superiore-pleistocene inferiore); g) depositi deltizi di città della pieve (pliocene superiore-pleistocene inferiore); h) depositi di ambiente salmastro-transizionale (pliocene superiore-pleistocene inferiore); i) macigno s.l. (oligocene-miocene); l) scaglia toscana (cretaceo-eocene); m) liguridi (cretaceo-paleocene); n) faglie dirette; o) faglie presunte; p) sovrascorrimenti; q) fiumi principali; r) traccia di sezione geologica; s) strati a giacitura suborizzontale; t) strati con inclinazione tra 5° e 10°; u) affioramenti principali: 1) fornace frazzi, 2) cdp1, 3) cdp2, 4) cdp3, 5) cdp4, 6) cdp5, 7) cdp6, 8) cdp7, 9) cdp8, 10) p.gio al piano, 11) s. biagio, 12) casaltoldo, 13) p.gio vaccaio, 14) le coste, 15) la trincea. 2. geological setting the study area (fig. 1a) is located in central italy, across the umbria-tuscany boundary; it covers a branch of the south chiana valley basin, a nw-se oriented extensional basin bounded to the east by the mt. peglia range, the paciano-panicale lineage and the trasimeno lake and to the west by the r a p o l a n o c e t o n a r a n g e . on western areas, the pre-pliocene substratum is referable to the scaglia toscana auct. and ligurids a u c t. units. whereas on the eastern ones it is ascribable to the macigno s.l. auct. unit, with a subordinate occurrence of scaglia toscana and ligurids, mainly south of 129plio-pleistocene deltaic deposits in the città della pieve area ... città della pieve (fig. 1a). east of città della pieve, on both the paciano-panicale lineage and the northern termination of mt. p e g l i a range the substratum is represented by prevailing oligocene to miocene “turbiditic” sandstone units (macigno s.l. auct.); limestone occurrence is very scarce in the area. ligurids locally crop out west of trasimeno lake (near castiglione del lago, s a n f a t u c c h i o and p a c i a n o), whereas they are more widely documented on the eastern side of r a p o l a n o cetona range, respectively north and west of città della p i e v e. the south c h i a n a valley basin developed as a marine environment from late miocene?-early pliocene to middle pliocene (pa s s e r i n i, 1965; ja c o b a c c i et al. , 1967; 1969; barberi et al., 1994; co s t a n t i n i & dr i n g o l i, 2002; ar u t a et al. , 2004; 2006); between middle pliocene and early pleistocene, a continental and coastal marine sedimentation took place. coastal marine deposits crop out in the c i t t à della pieve and c h i u s i a r e a s (deltaic deposits), as well as in the eastern side of the r a p ol a n o c e t o n a range (beach to offshore deposits). previous authors attributed the same early-middle pliocene age to deposits on both sides of the valley (fig. 2), with local occurrence of lower ple istocene deposits both north and south of città della pieve ( pa s s e r i n i, 1965; ja c o b a c c i et al., 1967; 1969; am b r o s e t t i et al., 1977; 1987). particularly, am b r o s e t t i et al. (1977; 1987) individuate two main depositional cycles in western umbria marine deposits, early-middle pliocene and early pleistocene in age, respectively, separated by a hiatus coincident with “a c q u atraversa” erosion phase (fig. 2). costantini & dringoli (2002) still confirm the early-middle pliocene age attr ibution for the western c e t o n a coastal marine deposits, whereas a late pliocene-early pleistocene age has been recently inferred for the città della pieve d e l t a i c deposits (fig. 2: bi z z a r r i, 2006; bizzarri & baldanza, 2007). as a result of the average ne dip of both deltaic and coastal marine sediments (fig. 1), older deposits crop out on the western side of the chiana valley basin, at least across the cetona–città della pieve transect. lower pleistocene continental deposits cover a wide area north of città della pieve, west of t r a s i m e n o lake, at least from tresa valley figure 2 summarized stratigraphic scheme for plio-pleistocene deposits between città della pieve (bizzarri, 2006; bizzarri & baldanza, 2007) and trasimeno lake areas (carg project “f. 310 passignano sul trasimeno”). a comparison with units proposed by am b r o s e t t i et al. (1977; 1987) for the città della pieve area is also provided. ccp=”conglomerato di città della pieve”; asct=”argille e sabbie del chiani-tevere”. schema stratigrafico riassuntivo per i depositi plio-pleistocenici dell’area tra città della pieve ( bi z z a r r i, 2006; bi z z a r r i & ba l d a n z a, 2007) e il lago trasimeno (progetto carg “f. 310 passignano sul trasimeno”). viene proposto il confronto con le unità proposte per l’area pievese da am b r o s e t t i et al. (1977; 1987). ccp=”conglomerato di città della pieve”; asct=”argille e sabbie del chiani-tevere”. 130 to farneta village; upper pliocene continental deposits are documented only in south-western areas, south from vaiano-villastrada alignment (fig. 1b). the development of trasimeno basin (figs. 1a, 2), from middle pleistocene onward, reflects the definitive emersion of western umbria and the sea retreat from t r a s i m e n o hills to orvieto area (girotti & mancini, 2003; mancini et a l., 2004; bi z z a r r i, 2006; ba r c h i et al., 2007). sedimentological analysis, as well as geological mapping for the carg “f. 310-passignano sul trasimeno” project (bi z z a r r i, 2006; ba r c h i et al., 2007; pa z z a g l i a, 2007; bi z z a r r i et al., 2008), allow us to describe four main unconformity-bounded stratigraphic units (ubsu), in the area amongst città della pieve, the t r a s i m e n o lake and the t a v e r n e l l e p i e t r a f i t t a b a s i n , with a t ime span from late pliocene to early pleistocene (figs. 1b, 2): i) città della pieve d e l t a i c deposits; ii) south chiana valley gravel braided river, sandy braided river and piedmont deposits; i i i) tavernelle-pietrafitta piedmont and lacustrine deposits; iv) tavernelle-pietrafitta lacustrine, swamp and alluvial plain deposits. this paper deals with f a c i e s a s s o c i ations, depositional setting and stratigraphic implications of città della pieve deltaic deposits and south chiana valley gravel braided river deposits (figs. 1b, 2), hence designated simply as unit a and unit b, respectively. 3. facies analysis some outcrops (fig. 1, tab. 1), roughly aligned along a sw-ne transect, have been chosen as representative of the facies variation documented in the area (bizzarri, 2006; 2007). furthermore, they allow both the collection of paleontological and stratigraphic samples and statistic sedimentological analyses. facies associations are described (fig. 3): a1 facies association – mixed marine and brackish deposits – it is made up of heterogeneous deposits represented by alternations of three prevailing facies: i) 10÷20 cm thick alternations of silty sand, silt and clay, with occurrence of wave ripple and clay chips on coarser horizons. ii) ripple-laminated, moderately well sorted fine to medium sand, with <2 cm thick clay horizons. iii) 0,5 to 1 m thick, weakly cemented lenticular-shaped conglomerate, made up of sub-rounded to rounded, plate to equi-dimensional cobbles (φmax12-15 cm, mps-mean particle size, s e n s u ne m e c & st e e l, 1984, ranging from 4 to 8 cm). parallel orientation of flattened clasts is common, as well as surface oxidation and borings. samples collected on fine-grained deposits reveal a brackish mollusc assemblage, associated to rare benthic foraminifera and late pliocene-early pleistocene nannofossil assemblages (tab. 2). a2 facies association proximal delta front d e p o s i t s – association is represented by about 2 m thick, wedge-shaped, roughly cross-stratified gravel, laterally grading to sand, alternated to up to 5 m thick, duneto ripple-laminated sand (figs. 3a-c). gravel bodies locally show a channelled basal surface, chiefly on e-w oriented cuts, and are mainly represented by rounded to well rounded, diffusely bored, limestone medium pebbles to coarse cobbles (fig. 5a). gravel lithology implications will be discussed further (see § 3.3, 5). sandy bodies, made of well sorted, medium to fine sand, show an upward transition of sedimentary structures from 2d-dunes to wave ripples (fig. 3c). some less than 5 cm thick, leaf-bearing silty horizons locally occur (fig. 3b). an oligotypic association with oysters and pectinids, as well as late pliocene-early pleistocene nannofossil assemblages, have been documented on sandy horizons (tab. 2). a3 facies association outer delta front deposits a3a sand bars – they are organized in sets of about 4 m thick, parallel cross-laminated sand bodies, made up of medium to fine, locally cemented and diffusely bioturbated, well sorted sand (fig. 3d). each body shows a similar organization, with a mollusc horizon (mainly flabellipecten sp.) at the base, a tangential and concave-upward cross-lamination and a diffuse thalassinoides isp. and ophiomorpha isp. bioturbation. scattered pectinids, oysters and rare gastropods are also present, whereas only scarce late pliocene-early pleistocene benthic foraminifera and nannofossil assemblages have been documented (tab. 2). a3 b interdistributary bay deposits – the sub association is represented by up to 2 m thick, locally ripple-laminated, fining-upward moderately sorted medium to very fine sand, alternated to 10 cm thick pebbly sand (fig. 3e). erosion surfaces and bioclastic lags are common, as well as large pectinid horizons. irregular cementation also occurs. some levels also grade upward to parallel-laminated silty clay. scarce late pliocene-early pleistocene benthic foraminifera and nannofossil assemblages (tab. 2) have been collected. a4 facies association prodelta deposits – association a4 is represented by massive to thinly laminated silty clay (fig. 4), passing upward to sandy silt and very fine sand; cemented horizons also occur. marine macrofossils, vegetal remains, rich foraminifer table 1 geographic data (latitude, longitude, elevation a.s.l.) of sampled sites and sedimentological logs. dati geografici (latitudine, longitudine, quota s.l.m.) dei siti campionati e dei log sedimentologici. 3.1 unit a città della pieve deltaic deposits the unit is characterized by about 250 m thick superposition of coastal marine deposits, related to a deltaic environment, with an average 5°÷8° ne dip. five r. bizzarri & a. baldanza 131 and early pleistocene nannofossil assemblages have been documented (tab. 2). 3.1.1 depositional architecture a transition from distal to proximal environments can be documented in the sw-ne distribution of facies associations (figs. 4, 6). concerning the attribution of facies associations to sub-environments (fig. 4), mixed marine and brackish deposits of the a1 facies association represent the distributary channel zone, at the transition between the external delta plain and the delta front. in turn, the latter seems to be articulated, both alongand across-shore (nw-se, ne-sw respectively), with documentation of proximal and distal mouth bars (a2a3 a), as well as of interdistributary bays among channel mouths (a3 b). on proximal zones, mouth bars show alternations of cross-stratified prograding beachface gravel and duneto ripple-laminated shoreface sand (a2). outer delta front is represented by tangential cross-laminated sandy dunes (a3a), related to high flow velocity and shallow water conditions. finally, silty clay deposits correspond to the prodelta (a4). facies associations suggest a broad and long-lasting river-fed coastal environment. both river and marine sedimentation table 2 paleontological assemblages collected on main sampled sites. associazioni paleontologiche documentate nei principali siti campionati. plio-pleistocene deltaic deposits in the città della pieve area ... 132 processes are well represented (fig. 5c), with important effects on deposit organization. this leads to a hypothesise of shallow water, wave dominated delta, in which river supply and wave reworking alternated (fig. 6). the large amount of gravel implies high-competence river flows, at least during build-up phases, and suggests alimentation from one or more gravel braided rivers. due to a total 250-300 m thickness of the città della pieve deltaic deposits, a long-lasting river system may be supposed, although a discontinuous supply, related to the complex interplay of climatic, tectonic and eustatic changes, may be expected. 3.2 unit b – south chiana valley coarse-grained river deposits the unit is constituted of at least 200 m thick continental deposits, showing a common 5÷10° ne inclination. two main f a c i e s associations have been documented: b1 facies association channelled gravel deposits it is represented by about 1-2 m thick and 10 m wide lenticularshaped bodies, with a bi-parted gravel and sand fill. the lowermost part is filled with 0,5-1,5 m thick clast-supported gravel (fig. 3f); clasts are variable in shape but always from subrounded to well rounded, and range from coarse cobbles to fine pebbles, with mps~10-15 cm. limestone lithology dominates (fig. 5b). the a and b axes tend to dispose horizontally or with a ( t ) b ( i ) current imbrications (co l l i n s o n & th o m p s o n, 1982). a subordinated poorly to moderately sorted, very coarse sand/granules matrix also occurs. a weak cementation has been locally documented, as well as occurrence of surface oxidation, due to subaerial exposition. the uppermost part of channel fill consists of trough cross-laminated, well-sorted medium to very coarse sand; locally cross-lamination is not clearly recognizable. b2 facies association roughly organized overbank d e p o s i t s association b2 i s mainly represented by finer deposits, compared to association b1, with prevalence of sand and only a local sensible amount of clay and silt (fig. 4). sandy deposits are represented by tabular to lenticular bodies, 2÷5 m thick and up to 20 m long, made up of through cross-laminated, moderately sorted to well sorted, fining-upward coarse to fine sand. clay/silt deposits are subordinate and represented by alternations of weakly cemented, massive sandy silt, massive clay bearing freshwater molluscs, mainly gyraulus albus figure 3 described facies associations. a) gravel-sand alternations of a2 facies association (ne-sw cut). b) channelled gravel of a2 f a c i e s association (e-w cut); sy=leaf-bearing silty horizons. c) particular of dunes and ripple in the sand from a2 facies association. d) crosslaminated and bioturbated sand of a3a facies association. e) ripple-laminated sand and siltclay draping of a3b facies association f) gravel-sand alternations of unit b. g, h) thin section features of calcarenite clasts from a2 gravel. associazioni di facies descritte. a ) alternanze ghiaie-sabbie dell’associazione di facies a2 (taglio ne-sw). b) ghiaie a geometria canalizzata dell’associazione di facies a2 (taglio e-w); sy=livelli siltosi con materia vegetale (foglie). c) particolare dell’organizzazione a dune e ripple dell’associazione di facies a2. d) sabbie a laminazione incrociata, bioturbate, dell’associazione di facies a3a. e) sabbie con ripple e drappeggio di silt-argilla dell’associazione di facies a3b. f) alternanze ghiaie-sabbie dell’unità b. g, h) sezione sottile di clasti di calcarenite appartenenti ai ciottoli dell’associazione a2. r. bizzarri & a. baldanza (muller) and bithynia leachi (sheppard), and laminated silty clay with root traces and vegetal remains (paleosoils). 3.2.1 depositional architecture deposits of unit b (figs. 4, 6) can be referred to a braided river environment. the roughly-organized overbank, with only local occurrence of paleosoils, suggests a high lateral mobility of interbedded channels in the river system. concentration of channelled bodies in well defined portions of the succession, with interbedding to overbank sands, leads to the hypothesis of an intermittent river activity, with alternation of high transport and long-lasting low activity phases, the latter recorded as erosion surfaces and paleosoils, with interpositions of overbank sands. gravel imbrications, as well as through cross-lamination of the sands, testify the existence of a channelled river current and refer b1 facies association to channel fill. although the scarce gravel organization could be partially explained with a mass movement component, inside river channel, and large clast movement itself requires high current velocity, a(t)b(i) imbrications are related to sub-critic flow conditions (froude number fr<1: co l l i n s o n & th o m p s o n, 1982; ei n s e l e, 1992). sand is in vertical continuity with gravel, and appears to be part of the same channel fill; through cross-lamination which is indicative of both high current velocity, still in condition of sub-critic flow, and reduced channel depth. the channel bi-partition, with a lower gravel and an upper sandy fill, partially resembles the donjek type river model (mi a l l, 1985); it can be interpreted in terms of different sedimentation phases, with alternation of gravel and sand transport and deposition by bed load streams inside channels. most of the sedimentation took place shallow water channels during floods, with large emersion of deposits during low water phases. channels of b1 facies association repeat for some tenth of metres, and irregularly alternate to b2 f a c i e s association deposits; the latter represent an unchannelled flow/sheetflood dominated environment, only temporarily involved by very fine sedimentation and soil development, referable to the floodplain. 3.3 preliminary statistic analyses on gravel on gravels of f a c i e s association a2 and b1, two distinct statistic analyses have been carried out, in 133 figure 4 top: geological profile across units a and b; bottom: selected sedimentological logs crossed by the geological profile. c.n.z.=calcareous nannofossil zones. see figure 1b for tract localization and table 1 for geographical data (latitude, longitude, elevation a.s.l.) of sedimentological logs. in alto: sezione geologica attraverso le unità a e b; in basso: log sedimentologici attraversati dalla sezione. c.n.z.= zone a nannofossili calcarei. la traccia di sezione è riportata in figura 1b, mentre i dati geografici (latitudine, longitudine, quota s.l.m.) dei log sono riportati in tabella 1. plio-pleistocene deltaic deposits in the città della pieve area ... order to reconstruct paleocurrent patterns and gravel lithology, and to verify the hypothesis of a common source. despite their very preliminary value, the collected data support the hypothesis of relations between the città della pieve deltaic deposits and the south chiana valley gravel river deposits. gravel lithology from four outcrops referable to a2 f a c i e s association and from four outcrops referable to b1 f a c i e s association has been considered (figs. 5a, 5b). for each outcrop, a 1 m high and 0,5 m long transect was considered, with determination of lithology of every clast inside. two lithologies prevail: i) cretaceous-palaeogene tuscan and ligurid calcarenite and micrite, ii) macigno s.l. sandstones. the percentages of other lithologies, particularly pliocene calcarenite, are negligible. limestone prevails on sandstone, with calcarenite dominance (figs. 5a, 5b); the bioclastic component of the calcarenites document a supply of various benthic and planktonic microfossils, cretaceous to oligocene in age (figs. 3g-h). the micropaleontological assemblages (d i s c o c y c l i n a spp., n u m m u l i t e s spp., a l v e o l i n a s p p . , g l o b o t r u n c a n a spp., globigerinoids, globorotalids, bryozoans, crinoids, echinoids, red algae), characterized by marked reworking phenomena, show affinities with the “calcareniti di dudda” a u c t. (tuscan succession) and “monte morello” auct. (ligurids) units. on the whole of coastal marine deposits, paleocurrents concentrate along two main directions, sw-ne and nwse, respectively orthogonal and parallel to the paleocoast. within the first group, sw directed currents prevail on ne ones, while nw and se directed currents have equivalent distribution (fig. 5c, left). the paleocurrent pattern can be related both to a sw coastal system progradation, linked to river supply, and to a redistribution of deposits alongshore. on the other hand, paleocurrents measured on a single outcrop referable to unit b (la trincea: fig. 5c, right), although documenting only local flow directions, seem to be consistent with a w-nw provenance of river deposits. 3.4 depositional model the two described units delineate a depositional and paleoenvironmental contiguity, during late pliocene and the beginning of early pleistocene, between the south c h i a n a valley continental basin and the città della pieve delta. the collected data lead to the reconstruction of a gently seaward incl ined delta profi le, with subenvironment articulation both alongand across-shore (fig. 6). mouth bar deposits, seaward decreasing in grainsize, were redistributed alongshore as gravel beaches and organized as prograding gravel and sand dunes acrossshore, with interposition of shoreface-like deeper interdistributary bays. on a profile parallel to paleocoast, shallower and deeper zone alternate, referable to channel mouths and bays respectively (fig. 6b). the c i t t à della pieve delta was fed by one or more braided rivers (figs. 6a, c). leaf-bearing silt horizons interposition to gravel (fig. 3b), as well as occurrence of mixed marine and brackish deposits, document the transitional zone between the two environments (fig. 6). 4. paleontological and stratigraphic data mollusc and foraminifera assemblages of unit a are scarce and oligotypic on gravelly and sandy deposits (a1 to a3 f a c i e s associations), whereas prodelta deposits (a4 f a c i e s association) are characterized by richer and more diversified assemblages (tab. 2); in any case, they lack biostratigraphic significance. on the other hand, nannofossils provide better stratigraphic data, and two main assemblages have been documented. samples collected on sands (s. biagio, cdp1, cdp4 outcrops: figs. 1b, 4; tab 1) are characterized by the occurrence of small gephyrocapsa spp. and can be referred to late pliocene-early ple istocene (mnn18–19a nannofossil zones). early pleistocene richer assemblages come from p.gio al piano and f.ce frazzi quarry outcrops (tab. 2): the former is characterized by small g e p h y r o c a p s a spp. and c a l c y d i s c u s 134 figure 5 statistic analyses on gravel. lithology of a2 (a) and b1 (b) facies associations gravels on eight selected outcrops (see figure 1b and table 1 for outcrop sites, text for details). c) paleocurrent patterns (flow directions) derived from a2 gravel on città della pieve area (left) and from b1 gravel on la trincea outcrop (right). analisi statistiche sui ciottoli. litologia dei ciottoli provenienti da otto affioramenti selezionati e riferibili alle associazioni di facies a2 (a) e b1 (b) (si veda figura 1b e tabella 1 per l’ubicazione degli affioramenti ed il testo per maggiori dettagli). c) distribuzione delle paleocorrenti (direzione dei flussi) dedotta dai ciottoli dell’associazione di facies a2 nell’area pievese (a sinistra) e da quelli dell’associazione di facies b1 nell’affioramento de la trincea (a destra). r. bizzarri & a. baldanza macyntirei (bukry & bramlette) loeblich & tappan and can be referred to mnn19b zone, whereas the latter, for the presence of medium gephyrocapsa spp. (sensu raffi, 2002), can be referred to mnn19b-c zones. both marine and brackish early pleistocene mollusc and foraminifer assemblages (g. inflata gl. cariacoensis zones), reported south and north of città della pieve (ambrosetti et al., 1987), agree with the collected data. a late pliocene-early pleistocene age for the città della p i e v e deltaic deposits can be presumed (figs. 2, 4). differently to previous authors (ambrosetti et al., 1977, 1987), early to middle pliocene foraminifera assemblages, with occurrence of globorotalia puncticulata (deshayes) and g. gr. crassaformis galloway & wissler, as well as the nannofossil assemblages dominated by discoaster spp. (ambrosetti et al., 1977), have not been documented. unit b continental deposits are very scarce in paleontological content; mollusc assemblages (tab. 2) col lected during the carg-p a s s i g n a n o p r o j e c t (bizzarri, 2006; bizzarri et al., 2008), and the remains of anancus arvernensis ( cr o i z e t & jo b e r t) reported from gravel bodies in the vaiano area (argenti, 2004), allow the attribution of unit b to late villafranchian (figs. 2, 4). 5. discussion in order to allow a reliable inference of the new data here proposed, some considerations about depositional and stratigraphic implications of the città della p i e v e deltaic deposits are needed. the occurrence of two main depositional cycles (fig. 2) proposed by ambrosetti et al. (1977; 1987) based upon two assumptions: i) deposits have a noteworthy difference in age and ii) they are divided by a main angular unconformity. these statements also lead authors to propose simple superposition contacts among units of lower cycle, and to mark the occurrence of a large non depositional and/or erosive gap, covering a time span from late pliocene to early pleistocene (“acquatraversa”: ambrosetti et al., 1977; 1987). the gravel and sand alternation (a2 facies association), in fact, develops with stable features along about the 2/3 of città della pieve hill thickness and not only on its top, as it was stated by previous authors, showing lateral continuity to sand of a3 f a c i e s associations (fig. 4). furthermore, nannofossil assemblages at the top of f.ce frazzi deposits (a4 f a c i e s association) and on sandy deposits (cdp1, cdp4 outcrops: a3 facies associations) can be referred to early pleistocene and to late pliocene-early 135 figure 6 depositional model. a) paleoenvironments distribution in plan. b) across-shore section. c) along-shore section. 1-1’, 22’=section tracts. modello deposizionale. a) articolazione in pianta dei paleoambienti. b) profilo ortogonale alla paleocosta. c) profilo parallelo alla paleocosta. 1-1’, 2-2’=tracce di sezione. plio-pleistocene deltaic deposits in the città della pieve area ... pleistocene, respectively (tab. 2). this little difference in age suggests f a c i e s eteropy between clays and sands, or a partial superposition of clays top to sands (fig. 4), but it is in contrast to the hypothesized vertical continuity between “argille di fabro” clay unit and “sabbie a flabellipecten” sandy unit proposed by previous authors (ambrosetti et al., 1977; 1987). analogous relations of lateral continuity/partial superposition occur between a2 and a1 facies association (figs. 4, 6, tab. 2). as a consequence, hypothetic time lines cross facies associations of unit a (figs. 4, 6, tab. 2) rather than corresponding to lithological variations, as previously inferred by am b r o s e t t i et al. (1977; 1987). the hypothesis of vertical unit superposition, indeed, is not confirmed. all these deposits are referable to a deltaic environment, with a time span from late pliocene to early pleistocene: a single stratigraphic unit, grouping the whole città della pieve deposits and including also mixed marine and brackish deposits of a1 facies association, seems to be more reliable. on the other hand, all the città della pieve deposits show a common, less than 10° north-eastern dip, and main unconformities, referable to 3r d order cycle boundaries, which have not been documented on outcrop. both deltaic and mixed deposits (a1 to a4 f a c i e s associations), documented in the città della pieve area, belong to a unique stratigraphic unit, late pliocene to early pleistocene in age, partially referable to the second depositional cycle of the succession proposed by am b r o s e t t i et al. (1977; 1987) for western umbria (“argille e sabbie del chiani-tevere” unit). a better connection can be found with the late pliocene – early pleistocene depositional cycle (“c h i a n i t e v e r e” unit) recently proposed for tiber valley south of orvieto (gi r o t t i & ma n c i n i, 2003; ma n c i n i et al., 2004). the other topic to debate regards the source and provenance of sediments that build up the città della p i e v e delta. taking into account deposit thicknesses, gravel-sand alternations of a2 facies association (figs. 3a-b) repeat 12 to 15 times in the core of città della pieve hill, for a total of 100-150 m, as can be observed on deep ravines west of the town. comparable values characterize sandy bodies of a3 a f a c i e s a s s o c i a t i o n (fig. 3d), whereas a4 deposits crop out only for ~20 m and show no variations on sedimentary structures. the whole thickness of unit a reaches 250-300 m. these values suggest a wide and long-lasting river alimentation for the delta system to accommodate the entire successions, although characterized by a discontinuous supply, with alternation of high river discharge and prevailing wave reworking phases. the repetition of the facies associations suggests a cyclic organization in depositional sequences, as the result of interaction among tectonic subsidence, sea-level variations, sediment supply and compaction. an account of the cyclicity is beyond the aims of this work, and study is still in progress. in summary, the facies associations of unit a can be referred to a wave-dominated delta built in correspondence to one or more stable and long-lasting river mouth. this kind of fluvial system, with steady characters along a time span of at least 500 ka, inferred by biostratigraphic data, necessarily implies the hypothesis of a stable, long-lasting and wide catchment area. the present day geological setting underlines the occurrence of two past continental domains (figs. 1a, 1b), coeval with the città della pieve delta, which can supposedly represent source areas for deltaic sediments: the south chiana valley basin to the north, and the tavernelle-pietrafitta basin to the east. deposits of unit b indicate the occurrence on the south-western part of trasimeno hills (figs. 1a, 1b) of a roughly organized braided river environment, characterized by a distinctive bi-parted gravel/sand fill. fluvial environment had a discontinuous activity, with the highest gravel transport consequent to main river activity phases. overbank is represented by prevailing sheetflood deposits, alternated with alluvial plain fine sediments and paleosoils. stratigraphic data (fig. 2) point out the stability of these environmental conditions for at least 500 ka, between late pliocene and early pleistocene. besides stratigraphic data, depositional architecture of that river environment matches with the alternation of river supply and marine reworking described for c i t t à della pieve deposits. moreover, the >200 m thickness estimated for unit b deposits (bi z z a r r i et al., 2008) is comparable to values proposed for unit a. f a c i e s analysis and paleontological determinations mark the occurrence, ne and n of città della pieve, of mixed marine and brackish deposits (fig 1b, tab. 2), easily referable to delta plain environment and transitional to braided river environment of unit b. paleocurrent pattern reconstructed for unit a agree with a nw-se proximal-distal facies transition. measures indicate two main orthogonal directions (fig. 5c); nw-se values aligned on along-shore direction, show a symmetrical distribution and are here related to longshore currents. across-shore, sw-ne oriented values confirm the dispersion of channel axis about a n-s direction, marking also a clear asymmetry, with a prevalence of sw-directed flows (fig. 5c), referable to a mean mouth bar progradation in the same direction. the subordinate ne-directed set also testify for across-shore wave reworking. the la trincea paleocurrent pattern, although indicative of only local flow conditions, still denotes a coherent trend compared to città della pieve ( f i g . 5c), and underlines a local western or north-western provenance of flows. gravel lithology analyses on both unit a and unit b sampled outcrops (figs. 3, 5a, 5b) reveal a prevalence, or a significant amount, of limestone coming from tuscan and ligurid lithostratigraphic units, although percentages vary with outcrops. abundance of cretaceous to palaeogene bio-calcarenites is a feature of tuscan and ligurid lithostratigraphic units, whereas they lack on umbria-marche western successions. sandstone gravels become important only close to the cropping out macigno s.l. f o r m a t i o n (figs. 1b, 5a, 5b); on the other hand, western outcrops show an absolute dominance of limestone (figs. 1b, 5 a, 5b). the scarce sandstone occurrence can be ascribed to its low preservation potential and its rapid disaggregation during river transport; in fact, both marine and continental sands contain a large amount of quartz presumably derived from sandstone erosion. gravel lithology agrees with a prevailing northern and western sediment supply, from sectors in which tuscan and ligurid lithostratigraphic units are more represented, whereas an eastern supply, due to prevailing sandstone substratum lithology east of città della pieve, seems negligible (figs. 1a, 1b). indeed, both gravel lithology and paleocurrent pattern are consistent with a northern alimentation for the città della pieve delta. basing on 136 r. bizzarri & a. baldanza depositional environment, age, f a c i e s transition and analogous sediment supply, this feeder system can be found on south c h i a n a valley braided rivers (unit b) . nevertheless, the northern hypothesis has been essentially neglected by previous authors (verri, 1877; 1885; 1889; 1892; 1918; lotti, 1899; 1900; merla, 1944; cattuto et al., 1983; 1992; ambrosetti et al., 1987; 1989), and an eastern alimentation, throughout the tavernellepietrafitta basin, as well as subordinated relations with tiber basin, was chosen. the lack of lithologies referable to the umbria-marche stratigraphic units both among unit a and b gravel, which should be documented on deposits of a large river, with a hydrographical basin of several hundred square kilometres, sharply contrasts with the hypothesis of a paleo-tiber delta ( ve r r i, 1877; 1885; 1889; 1892; 1918; lo t t i, 1899; 1900; merla, 1944). a local eastern supply hypothesis (paleo-nestore: cattuto et al., 1983; 1992; ambrosetti et al., 1987; 1989) denotes some incongruence with the previously explained data. first of all, pre-pliocene substratum all around the tavernelle-pietrafitta basin, both on the paciano-panicale lineage and the northern termination of m. peglia range, is today represented by oligo-miocene turbiditic sandstones (macigno s.l. auct.), whereas limestone units are not widely diffused and mainly confined on a far, south-western portion (fig. 1a). this lithological homogeneity reflects on gravel, almost exclusively arenitic and with less than 10% of limestone, on all the outcrops of the basin (pazzaglia, 2007). the depositional context appears even more in contrast: the tavernelle-pietrafitta basin was characterized, during late villafranchian, by a lacustrineswampy rather than by a fluvial environment, and was widely bounded, also toward città della pieve, by a large thickness of piedmont deposits (figs. 1b, 2). the tavernelle-pietrafitta basin shows, indeed, a centripetal and prevailing eastward river drainage at least during early pleistocene, not consistent with the alimentation of the città della pieve delta. thus, the hypotheses involving eastern supply and temporary communication with the paleo-sea between late pliocene and early pleistocene, still not rejectable, are not satisfactory for a comprehensive interpretation of the collected data. another possibility to evaluate is an origin from deposits far (both in time and space) from their final sedimentation area. from this point of view, the reworking of previous deposits, a sort of “cannibalization”, related to a different environment and/or a previous basin must been considered. the hypothesis of reworked gravel, with the città della pieve delta representing only the last depositional environment, still leads to a northern or north-western supply. the limestone-dominated deposits can result from substratum erosion at the miocene-pliocene boundary or during early pliocene; that substratum, tectonically-dislocated and buried under about 400 m thick plio-pleistocene deposits, is now only inferred from seismic sections under t r a s i m e n o lake (ba r c h i et al., 2007; bi z z a r r i et al. , 2008). in fact, the small substratum occurrences in the wide trasimeno hill area (fig. 1a) are characterized by ligurids a u c t . (c. del lago, sanfatucchio, paciano) , scaglia toscana s.l. (isola minore) and macigno s.l. (isola maggiore, isola polvese), and only partially reflect the composition of substratum on the eastern side of present-day trasimeno lake. on the other hand, material origin can be somehow put in relation with thick gravel deposits, with prevai ling bio-calcarenit ic tuscan/ligurid clasts, deposited during early-middle pliocene on r a p o l a n o c e t o n a range western side (conglomerati de la foce: passerini, 1965; jacobacci et a l., 1967; 1969; co s t a n t i n i & dr i n g o l i, 2002), interpreted as northern river fan delta deposits into the r a d i c o f a n i basin (co s t a n t i n i & dr i n g o l i, 2002). at the emersion of r a d i c o f a n i basin area, from middle-late pliocene onward (ba r b e r i et al., 1994), the hypothesis of reworking, due to south chiana valley rivers must be considered: the southward shift of river systems led to deposition on the città della pieve area between late pliocene and early pleistocene. 6. conclusions sedimentological and stratigraphic data here proposed, still supporting the deltaic origin for città della pieve coastal marine deposits, which shed new light on both age of deposits and river supply source. depositional and paleoenvironmental contiguity, gravel lithology and stratigraphic position mark a clear lateral sw continuity between these deposits and the south chiana valley gravel river systems; indeed, they represent the transition to open marine environment. from this point of view, the plio-pleistocene città della pieve deltaic deposits belong to the south chiana valley basin and can be related to a 3rd order late plioceneearly pleistocene depositional cycle, only partially corresponding to “argille e sabbie del chiani-tevere” cycle of ambrosetti et al. (1977; 1987) and comparable to the chiani-tevere unit described in the orvieto area (girotti & mancini 2003; mancini et al., 2004). acknowledgments we wish to thank dr. patrizia argenti for paleontological expertise, as well as dr. massimiliano bilotta and prof. leonsevero passeri for their precious suggestions. references ambrosetti p., carboni m.g., conti m.a., esu d., girotti o., la monica g.b., landini b. & parisi g. (1987) il pliocene ed il pleistocene inferiore del bacino del fiume tevere nell'umbria meridionale geogr. fis. dinam. quat., 10, pp. 10-33. am b r o s e t t i p., ca t t u t o c. & gr e g o r i l. (1989) g e omorfologia e neotettonica nel bacino di tavernelle/pietrafitta (umbria) il quaternario, 2 (1), pp. 57-64. ambrosetti p., conti m.a., parisi g., kotsakis t. & nicos i a u. (1977) neotettonica e cicli sedimentari plio-pleistocenici nei dintorni di città della pieve (umbria) boll. soc. geol. ital., 96, pp. 605-635. ar g e n t i p. (2004) plio-quaternary mammal fossiliferous sites of umbria (central italy) geol. romana, 37, pp. 67-78. aruta g., borgia a., bruni p., cecchi g., cipriani n. & tr e d i c i y. (2004) pliocene and pleistocene 137plio-pleistocene deltaic deposits in the città della pieve area ... unconformity bounded stratigraphic units (ubsu) in val di chiana in: morini d & bruni p. (eds.), the “regione toscana” project of geological mapping. firenze, pp. 133-136. aruta g., bruni p. & cecchi g. (2006) il quadro stratigrafico della successione plio-pleistocenica della val di chiana atti del convegno “il sollevamento quaternario nella penisola italiana e nelle aree limitrofe”, roma, 6-8 febbraio 2006, pp. 17-18. barberi f., buonasorte g., cioni r., fiordelisi a., foresi l., iaccarino s., laurenzi m.a., sb r a n a a., ve r n i a l. & villa i.m. (1994) plio-pleistocene geological evolution of the geothermal area of tuscany and latium mem. descr. carta geol. it., 49, pp. 77134. barchi m.r., bortoluzzi g., gasperini l., ligi m. & pauselli c. (2007) tectono-sedimentary evolution of the lake trasimeno: a seismic reflection study rend. soc. geol. it., nuova serie, 5, pp. 54-56. bizzarri r. (2006) depositi plio-pleistocenici tra la val di chiana e il lago di corbara: caratterizzazione sedimentologica e ricostruzione paleoambientale phd thesis, perugia university, 408 pp. bizzarri r. (2007) late pliocene-early pleistocene fluvial paleocoasts in western umbria (central italy): facies analysis and sedimentation models geoitalia epitome, 2, pp. 393-394. bi z z a r r i r. & ba l d a n z a a. (2007) late pliocene and early pleistocene of the orvieto area (central italy): a stratigraphic review geoitalia epitome, 2, p. 399. bi z z a r r i r., pa z z a g l i a f., ba r c h i m.r., pa s s e r i l. & argenti p. (2008) inquadramento stratigrafico dei deposit i continentali quaternari nel f. 310 “passignano sul trasimeno” ed evoluzione dei bacini plio-pleistocenici del confine tosco-umbro atti del convegno “il quaternario nella cartografia carg” (roma, 21-22 febbraio 2008), p. 10. ca t t u t o c., ce n c e t t i c. & gr e g o r i l. (1992) il pliopleistocene nell’area medio-alta del bacino del f. tevere: possibile modello morfotettonico studi geol. camerti, vol. spec. 1, pp. 103-108. cattuto c., gregori l. & parisi g. (1983) indizi di tettonica pleistocenica nel bacino del t. tresa (lago trasimeno) geogr. fis. dinam. quat., 6 (1), pp. 16-20. colalongo m.l. & sartoni e. (1979) schema biostratigrafico per il pliocene ed il pleistocene in italia contr. prelim. carta neotett. d’it., 2 5 1, pp. 645654. co l l i n s o n j.d. & th o m p s o n d.b. (1982) s e d i m e n t a r y s t r u c t u r e s george allen & unwin, london, 194 pp. co s t a n t i n i a. & dringoli r. (2002) geologia dell’area fra chianciano bagni e sarteano (provincia di s i e n a ) carta geologica, università di siena. s.e.l.c.a., firenze, 2002. ei n s e l e g. (1992) sedimentary basins. evolution, facies, and sediment budget springer-verlag, berlin, 628 pp. girotti o. & mancini m. (2003) plio pleistocene stratigraphy and relations between marine and non marine successions in the middle valley of tiber river (latium, umbria) il quaternario, 16, pp. 89106. jacobacci a., malatesta a. & martelli g. (1969) note illustrative della carta geologica d'italia alla scala 1:100000; foglio 121 "montepulciano" serv. geol. d'italia. jacobacci a., martelli g. & nappi g. (1967) note illustrative della carta geologica d'italia alla scala 1:100000; foglio 129 "santa fiora" serv. geol. d'italia. lotti b. (1899) rilevamento geologico nei dintorni del lago trasimeno, di perugia e di umbertide boll. r. com. geol. d'it., 30, pp. 207-218. lo t t i b. (1900) rilevamento geologico eseguito nel 1899 nei dintorni del trasimeno e nella regione immediatamente a sud fino ad orvieto boll. r. com. geol. d'it., 31, pp. 159-174. lo t t i b. (1926) descrizione geologica dell'umbria mem. descr. carta geol. d’it., 21, 320 pp. ma n c i n i m., gi r o t t i o. & ca v i n a t o g.p. (2004) i l pliocene ed il quaternario della medie valle del tevere (appennino centrale) geol. romana, 37, pp. 175-236. merla g. (1944) il tevere. geologia e permeabilità dei terreni del bacino mon. idr. n° 22 serv. idrol. min. ll. pp., roma, 130 pp. mi a l l a.d. (1985) architectural-element analysis: a new method of facies analysis applied to fluvial deposits earth sc. rev., 22, pp. 261-308. nemec w. & steel r.j. (1984) alluvial and coastal conglomerates: their significant features and some comments on gravelly mass flow deposit in: koster e.h. & steel r.j. eds., sedimentology of gravels and conglomerates. cspg memoir, 1 0, pp. 1-31. passerini f. (1965) il monte cetona (provincia di siena) boll. soc. geol. it., 83 (4), pp. 219-338. pazzaglia f. (2007) evoluzione tettonico –sedimentaria dei bacini quaternari minori tra la val di chiana e il bacino tiberino phd thesis, perugia university, 193 pp. ra f f i i . (2002) revision of the early – middle pleistocene calcareous nannofossil biochronology (1.75-0.85 ma) marine micropal., 45, pp. 25-55. rio d., raffi i. & villa g. (1990) pliocene-pleistocene calcareous nannofossil distribution patterns in the western mediterranean in: kastens k. & mascle j. (eds.), proc. odp science results, 1 0 7, pp. 513-533. verri a. (1877) alcune linee sulla val di chiana e luoghi adiacenti nella storia della terra bizzoni, pavia, 100 pp. verri a. (1885) la val di chiana nel periodo pliocenico boll. soc. geol. it., 4, pp. 1-13. ve r r i a. (1889) note a scritti sul pliocene umbro sabino e sul vulcanismo tirreno tipografia dei lincei, roma, pp. 5-16. verri a. (1892) note sul territorio di città della pieve estratto dal giornale l'umbria agricola del 30/12/1892, 12, pp. 32-36. verri a. (1918) l'altopiano di città della pieve boll. soc. geol. it., 37, pp. 53-92. 138 ms. ricevuto il 5 novembre 2008 testo definitivo ricevuto il 16 aprile 2009 ms. received: november 5, 2008 final text received: april 16, 2009 r. bizzarri & a. baldanza amq34(2) 201-211 lopezgarcia et al def.pdf available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 34 (2), 2021, 201-211 using small mammals to reconstruct the climatic context of the late pleistocene lagar velho rockshelter (leiria, portugal). juan manuel lópez-garcía 1,2, carlos pimenta 3, ana cristina araújo 3,4,5, ana maria costa 3,4,6, montserrat sanz 5,7, joan daura5,7 1 institut català de paleoecologia humana i evolució social (iphes-cerca), campus sescelades urv, tarragona, spain. 2 universitat rovira i virgili, departament d’història i història de l’art, tarragona, spain. 3 laboratório de arqueociências (larc)-dgpc, lisboa, portugal. 4 inbio, and cibio, university of porto, portugal. 5 uniarq-centro de arqueologia da universidade de lisboa, universidade de lisboa, lisboa, portugal. 6 idl, instituto dom luiz, universidade de lisboa, lisboa, portugal. 7 grup de recerca del quaternari, grq-serp, department of history and archaeology, university of barcelona, barcelona, spain. corresponding author: juan manuel lópez-garcía <jmlopez@iphes.cat> abstract: to reconstruct the climatic conditions of the lagar velho rockshelter during the late pleistocene, we applied the bioclimatic model to the rodent assemblages, mainly composed of the vole species arvicola sapidus, microtus arvalis, microtus agrestis, microtus (terricola) lusitanicus and microtus (iberomys) cabrerae and the field mouse apodemus sylvaticus. based on the distribution of these species by layers and percentages, considering different climate-types, and applying a series of functions, it was possible to estimate the mean annual temperature (mat), the mean temperature of the coldest month (mtc), the mean temperature of the warmest month (mtw) and the mean annual precipitation (map). for comparative purposes, the resulting parameters were compared with climate data obtained for the last 30 years from nearby meteorological stations in order to attain averages and observe climatic fluctuations. the climatic parameters were then compared with the köppen-geiger classification in order to contrast our data with the current climate-types. finally, we combined the results with chronological and environmental information to produce a climate framework within marine isotope stage 2 (mis 2). keywords: bioclimatic model, köppen-geiger classification, marine isotope stage 2, heinrich events, last glacial maximum, iberian peninsula. 1. introduction marine isotope stage 2 (mis 2; ca. 29 to 14.9 kyr b.p.) corresponds to the last portion of the most recent glaciation (ishiwa et al., 2019). in the iberian peninsula, the pollen spectra for mis 2 suggest in general an open landscape dominated by semi-arid vegetation (fletcher & sanchez-goñi, 2008). this stage includes the last glacial maximum (lgm, ca. 27-17 kyr b.p.), when the ice sheets reached their greatest volume (hein et al., 2010; ishiwa et al., 2019, among others). it also includes the most recent heinrich events, which produced the ird (ice-rafted debris) layers observed in marine sediment cores from the north atlantic, notably heinrich event 3 (h3; ca. 31-29 kyr b.p.), which caused the collapse of the northern hemisphere ice shelves and the consequent release of a prodigious volume of icebergs (bond & lotti, 1995; hemming, 2004, among others). pollen studies have shown that lgm was characterized by humid conditions in southwestern europe, allowing the development of arboreal vegetation, a factor that further distinguishes it from the mis 2 heinrich events, during which there was a notable predominance of semiarid vegetation (fletcher & sánchez–goñi, 2008; kageyama et al., 2005; peyron et al., 1998). likewise, faunal assemblages (small and large mammals) shows for the lgm in the iberian peninsula the presence of numerous temperate taxa, such as cervus elaphus, capreolus capreolus or vulpes vulpes (sommer & nadachowski, 2006). indicating that iberia acts as glacial refugia for the temperate species. in the light of this brief environmental characterization, the present study applies a bioclimatic model (following hernández-fernández, 2001a, 2001b) to the analysis of the rodent assemblages of the lagar velho rockshelter, located in the lapedo valley (leiria, portugal). the aim is to infer various climatic parameters, which will be further compared with the present climatic data, taking into account the available studies of the lgm and h3 small-vertebrate assemblages. https://doi.org/10.26382/amq.2021.04 202 lópez-garcía j.m. et al. fig. 1 1 and 2: location of the main sites mentioned in the iberian peninsula, including the lagar velho rockshelter (2). 3: plan of the lagar velho rockshelter showing the location of lv1 burial. 4 and 5: the hanging remnant (tp) with the position of tp06 and tp09 (courtesy of joão zilhão). 203 2. the lagar velho site and the lapedo child the lagar velho rockshelter (abrigo do lagar velho-alv; 30°45’25”n; 8°43’58”w) is located in the lapedo valley in the municipality of leiria, about 135 km north of lisbon (fig. 1.1,1.2), on the left bank of the caranguejeira stream. it was first discovered and excavated in late 1998, soon after the identification of the lv1 infant burial (duarte et al., 1999). the top two/three metres of sediment overlying the burial had previously been removed by the shelter-owner by mechanical means; all that survived was a profile trapped inside a recess in the back wall of the shelter and labelled “hanging remnant” (testemunho pendurado / tp in portuguese; henceforth tp; fig. 1). on the one hand, levels tp09 and tp06 (see fig. 1), which contain the small-mammal remains analysed in the present study, are included in the upper slope deposits (us), defined during the 1998 and 1999 investigations (angelucci, 2002 in zilhão & trinkaus, 2002). the us sedimentary complex preserves traces derived from archaeological occupations that took place at alv between the terminal gravettian (level tp06) and the middle solutrean (level tp09) (zilhão & almeida, 2002). these units are in general characterized by a coarse sedimentary component of angular limestone slabs originating from the shelter wall, and by a finer component of sandy silts and clayey silts rich in anthropogenic remains (angelucci, 2002). registered in the lower part of the us complex, level tp06 (fig. 1.4) is characterized by sandy, dark browngrey sediment with limestone clasts, with a maximum thickness of ca. 30 cm. it contains a much higher amount of archaeological remains than the overlying level tp09. radiocarbon dating suggests that it was deposited between 25976-24955 cal yr b.p. (using the most consistent 14c date of 21180±240 b.p.; pettitt et al., 2002; tab. 7-4). level tp09 (fig. 1.5) is chaotically arranged in terms of its inclination and orientation. it comprises numerous limestone blocks and platelets of various dimensions, detached from the shelter wall by mechanical or cryogenic action. it has a maximum thickness of approx. 18 cm. the finer component consists of thin sands of a light cream colour, sometimes whitish, especially at the top in contact with the limestone, indicating some later carbonation of this deposit. charcoal appears in large amounts and is ubiquitously distributed; faunal remains, also very numerous, show a relatively poor state of conservation. this unit is 14c dated to 20200±180 (pettitt et al., 2002, table 7-4), i.e. 2490623877 cal yr b.p., 95% confidence (tab. 1; fig. s1). on the other hand, the upper fine gravel and sand complex (gs) analysed in the framework of the present study was identified immediately under the artificial surface created after the bulldozer terracing and corresponds to the sedimentary layer where the infant was buried (fig. 1.3). the burial was a single episode involving a complex and careful ritual (duarte, 2002; zilhão, 2005). the small mammal recovered in this sedimentary unit was not directly related to the burial, but to the sediments that accumulated in the level where the grave was opened. radiocarbon dating of the burial has provided four 14c dates from remains accompanying the burial, giving a range between 27637-29407 cal yr b.p. (pettitt et al., 2002; zilhão & almeida, 2002) (tab. 1; fig. s1). another 14c sample from the bs/tc complex interface, i.e. around 1m below the sepulchre, gives a range between 31278-30191 cal yr b.p. (tab. 1; fig. s1). therefore, the small mammals date to between the burial event (ca. 29.4-27.6 kyr b.p.) and the age obtained for the underlying layer (ca. 31 kyr b.p.). 3. material and methods 3.1. small-mammal sorting, palaeontological and taphonomic studies and palaeoenvironmental reconstruction the small-mammal fossil remains used in this study come from layers tp06, tp09 and from the sediments where the lv1 child was buried, in the upper gs complex. the assemblage consists of disarticulated bone fragments collected in a very small volume of sediments (ca. 1 m3), although this is extremely rich in faunal remains. sediments from the tp layers were water-sieved through a 2.5 mm mesh in the field (moreno-garcía & pimenta, 2002), whereas the sediments from the child burial were water-sieved through a 1.5mm mesh in the laboratory (moreno-garcía, 2002). a preliminary smallmammal list was published by moreno-garcía & pimenta (2002), and a revision was recently undertaken in january 2020 at the laboratório de arqueociências (larc) in lisbon, during a short stay by the corresponding author. the assemblage under study is small and includes a total of 135 identified remains, corresponding to a minimum number of 75 individuals belonging to 11 different taxa (tab. 2; fig. 2). the fragments were identified at larc following the general criteria of systematic palaeontology (appendix s1). specific identification was based principally on the best diagnostic elements, such as mandible and maxilla for shrews and hedgehogs; first lower molars for the subfamily arvicolinae; and mandibles and maxilla for the subfamily murinae. specimens were grouped using the minimum number of individuals (mni) method, determined by counting the most diagnostic element of each species by layers. following andrews (1990) and fernández-jalvo et al. (2016), alterations caused by digestion in the first lower molars of the arvicoline rodent species were observed, but a probable bias in the methodology of collecting the samples small mammals from lagar velho rockshelter tab. 1 radiocarbon results for tp06, tp09 and child’s burial sediments modified from pettitt at al. (2002) and calibrated using oxcal 4.2.4 software (bronk ramsey, 2009) and the intcal’13 curve (reimer et al. 2013). 204 lópez-garcía j.m. et al. fig. 2 some small-mammal material identified from the studied levels of lagar velho. a. left mandible sorex sp. (buccal view); b. left mandible crocidura cf. suaveolens (buccal view); c. left m2 talpa cf. occidentalis (buccal view); d. right m1 arvicola sapidus (occlusal view); e and f. left and right m1 microtus agrestis (occlusal view); g and h. two left m1 microtus arvalis (occlusal view); i and j. right and left m1 microtus (iberomys) cabrerae (occlusal view): k and l. right and left m1 microtus (terricola) lusitanicus (occlusal view); m and n. left m1 and m1 apodemus sylvaticus (occlusal view). scales 1 mm. small mammals from lagar velho rockshelter 205 precluded a quantitative taphonomic interpretation. this is because the screen meshes both of 2.5 mm used for the tp layers and of 1.5 mm used for the child burial were too large to recover certain small microvertebrate elements considered relevant to this research. this comes to light through the absence of isolated teeth belonging to small taxa such as a. sylvaticus or s. cf. granarius (appendix s1). finally, the application of quantitative palaeoenvironmental methods such as habitat weightings (see evans et al., 1981; andrews, 2006) was also ruled out by the methodological bias of the sample collecting. however, we took into account the current habitat preferences of the identified species for our interpretation and discussion, using the published works of palomo et al. (2007) and bencatel et al. (2017). 3.2. palaeoclimatic reconstruction considering the bias recovering the small-mammal and the low number of small mammals remains recovered, quantitative methods have been avoided. then we used a method for the obtention of climatic parameters based on the faunal list. after that, to reconstruct the climatic conditions at alv during the above-mentioned human occupations we used the bioclimatic model (hernández-fernández, 2001a and b). this method is based on the hypothesis that a significant correlation exists between climate and mammal communities. the rodent assemblage from the three analysed layers at alv corresponds to four of the ten climatic types described by hernández-fernández (2001a and b), hernández-fernández & pelaez-campomanes (2005) and hernández-fernández et al. (2007): iv, subtropical with winter rains and summer droughts; vi, typical temperate; vii, arid temperate; and viii, cold temperate (boreal). the assemblages were analysed using the climatic restriction index (crii= 1/n, where “n” is the number of climatic zones where the species are represented and “i” is the climatic zone where the species appears) (table 3). the bioclimatic component (bc; representation, by level, of each of the four represented climates) was then calculated using the following formula: bci=(∑ crii) x 100/s, where s is the number of species per unit of each site (tab. 3). from bc, a mathematical model was elaborated using a multiple linear regression (hernández-fernández & peláezcampomanes, 2005). by means of a series of functions, this yielded estimates for the mean annual temperature (mat), the mean temperature of the coldest month (mtc), the mean temperature of the warmest month (mtw) and the mean annual precipitation (map) (table s1). a comparison was drawn with 30-year climatic data (from climate-data.org) from the meteorological station of leiria (leiria, portugal), located at 36 m above sea level (a.s.l.), with mat=15.9°c, mtw=21.1°c, mtc=10.8°c and map=790 mm. to place our data in a global context, we used the köppen-geiger climatic classification (köppen & geiger, 1936), with updates according to peel et al. (2007) and beck et al. (2018). this classification is based on mean annual and monthly temperatures and precipitation, using the native vegetation to determine the climate types. tab. 2 representation of the small-mammal material identified from the lagar velho rockshelter. nisp is the number of identified specimens; mni is the minimum number of individuals; and % is the percentage of mni. tab. 3 distribution of the rodent species identified from the different analysed sites according to their climate preferences, in accordance with hernández-fernández (2001b) and hernández-fernández et al. (2007). iv subtropical with winter rains and summer droughts; vi typical temperate; vii arid-temperate; viii cold-temperate (boreal). cri: climatic restriction index; bc: bioclimatic component. 206 lópez-garcía j.m. et al. tab. 4 relation of temperatures and precipitation for the different studied layers; mat, mean annual temperature; mtw, mean temperature of warmest month; mtc, mean temperature of coldest month; map, mean annual precipitation; present-day values from the leiria meteorological station; δ : di erence between the values obtained by analysing rodents from the different sites and the present-day mean. fig. 3 chronological position of the studied levels of lagar velho (x axis) in relation to the benthic 18o (y axis) isotope curve (modified from lisiecki & raymo, 2005). 4. results and discussion 4.1. the small-mammal composition of the lagar velho rockshelter and some palaeoenvironmental remarks the small-mammal remains recovered from the different layers of the lagar velho site are scarce, but the number of identified species is relatively high, with at least ten taxa. from the point of view of the presence / absence of species, the small-mammal composition is very constant, with the three studied layers showing few differences (tab. 2). erinaceus sp. is present in the upper part of the gs complex where the child was buried, whereas talpa occidentalis and sorex sp. are absent. in level tp06 erinaceus sp., microtus arvalis and also sorex sp. are absent, whereas in tp09 the only absent species is erinaceus sp. (tab. 2). from a quantitative point of view (although this should be taken with caution due to the scarcity of remains), the sediment excavated in the upper gs complex possesses the greatest representation of the small-mammal assemblage (tab. 2), with arvicola sapidus, microtus (terricola) lusitanicus and apodemus sylvaticus being identified. these three species are widely distributed nowadays in portugal, and their relative abundance indicates an open forest and relatively humid conditions with stable water courses surrounding the site (paupério et al., 2017). arvicola sapidus, microtus (terricola) lusitanicus, microtus agrestis and apodemus sylvaticus, identified in layer tp06, represent almost 85% of the small-mammal assemblage (tab. 2). of these four species, microtus agrestis occurs almost exclusively in the north and centre-north of portugal (paupério et al., 2017), but it is also widely distributed in the northern part of the iberian peninsula from galicia to the pyrenees (palomo et al., 2007). their relative abundance in tp06 indicates open forest with relatively humid conditions and stable water courses in the vicinity of the site. the dominant species in tp09 are the same as in tp06, representing almost 80% of the smallmammal assemblage, although unlike in the previous layer microtus arvalis is represented (tab. 2). microtus arvalis is currently found in the extreme northeast of portugal (paupério et al., 2017) and may indicate drier conditions during the accumulation of layer tp09. other proxy studies conducted on the archaeological remains, e.g. studies of the archaeobotanical and other vertebrate taxa, indicate the following: 1) that the charcoal documented in the child burial shows a lower degree of preservation, but there are specimens belong to pinus sylvestris s.l. (queiroz, 2002); 2) that analysis of the pollen recovered from the excavation pit under the child burial does not provide a basis for palaeovegetation and palaeoenvironmental reconstruction (queiroz et al., 2002); and 3) that oryctolagus cuniculus represents more than 85% of the faunal assemblage identified in the burial (moreno-garcía, 2002). for layers tp06 and tp09, however, the presence/absence of certain types of charcoal reflects both the local vegetation and the choices of the human groups. no major differences were detected between layers and samples. the species pinus sylvestris, erica arborea, cytisus scoparius and ulex sp. represent at least 80% of the total assemblage. the scots pine is the dominant arboreal taxon, indicating an open, forested landscape without evidence of mediterranean-type vegetation (queiroz et al., 2002). this pattern partially coincides with our small-mammal data, where open forest is well represented in both tp layers by apodemus sylvaticus and microtus (terricola) lusitanicus. in addition, the largemammal assemblage identified in tp06 shows a predominance of horse (equus sp.), followed by red deer (cervus elaphus) and hare (lepus sp.), indicating the occurrence of more open spaces of a grassland type. the abundance of the above-mentioned species in tp09 is accompanied by an increase in wild boar, the occurrence of roe deer and lynx, and a decline in hare relative to tp06. these data suggest an increase in forest cover compared to the fauna recovered from the sediments underlying the burial grave (moreno-garcía & pimenta, 2002). the large-mammal data for the tp units coincide with a slight increase in the representation of small-mammal species associated with forest requirements, such as apodemus sylvaticus, from layer tp06 (where this species represents 11.5% of the small -mammal assemblage) to layer tp09 (where it represents 14.7% of the small-mammal assemblage). statistically, application of the chi-square test to the smallmammal taxa represented in both units and the mni shows there to be no significant differences in the smallmammal composition between tp09 and tp06, yielding the same probability p (same)= 0.7998. 4.2. palaeoclimatic reconstruction the 14c results obtained for the two tp units and the child burial (zilhão & almeida, 2002) suggest that the burial may have occurred between heinrich event 3 (he 3) and interstadial 4 (is 4), and tp06 and tp09 during the last glacial maximum (lgm) (fig. 3). using the rodent assemblage to compare the lagar velho data with current climatic data (tab. 4), the bioclimatic model points to conditions that were cooler (∆mat between -2.58°c and -2.56°c) and dryer (∆map between -488 mm and -126 mm) for all studied layers. the thermal gradient between summer and winter was higher than at present (∆mtw between +1.58°c and +2.65°c; ∆mtc between -7.87°c and -6.12°c), providing a more continental-temperate climate (warm summers, very cold winters and low rainfall) than presentday conditions, which are characterised as mediterranean oceanic (mild summers and mild, rainy winters). indeed, in terms of the köppen-geiger climatic classification (modified from peel et al., 2007 and beck et al., 2018), the current climate at leiria is considered csb (mediterranean oceanic), with mtw values not exceeding 22°c and mtc above 0°c , whereas the climate projected from the alv rodent assemblage shows a dfa climate (continental temperate), with mtw values above 22°c and mtc below 0°c . these data may explain the coexistence of species with different ecological requirements that do not have an analogous distribution nowadays, according to sans-fuentes & ventura (2000) and lópez-garcía et al. (2010a). species with mid-european requirements such as microtus arvalis and m. agrestis appear together with species of strictly mediterranean requirements such as m. (iberomys) cabrerae. although the anthracological studies of layers tp06 and tp09 (queiroz et al., 2002) have shown no evidence of mediterranean species among the charcoal samples, the small-mammal assemblage points to the presence of mediterranean species such as the taxon m. (iberomys) cabrerae (tab. 2), albeit in low numbers. 4.3. lagar velho in the context of the iberian mis 2 the discovery at the time of an upper palaeolithic (late pleistocene) burial, highlighted the importance of the lagar velho rockshelter, which represented the evidence of the presence of modern humans in southern iberia during the mis 2 (duarte et al., 1999). chronologically similar, there are other mis 2 sites in the iberian peninsula where h3 and lgm have been detected on the basis of small-vertebrate studies. for h3 we found the galls carboners site located at montral (tarragona, northeastern iberia) (lópez-garcía et al., 2014), whereas for lgm we found various sites: layers c and b of l’arbreda cave in serinyà (girona, northeastern iberia) (lópez-garcía et al., 2015); maltravieso-chimeneas cave in cáceres (extremadura, western iberia) (bañuls-cardona et al., 2012); layer p1 of el portalón cave at sierra de atapuerca (burgos, northern iberia) (lópez-garcía et al., 2010b) and the lower unit of valdavara-1 cave in becerreá (lugo, northwestern iberia) (lópez-garcía et al., 2011). as expounded above, the scarcity of small-mammal remains may make climatic interpretations and correlations difficult. nonetheless, the qualitative climatic data obtained from the rodent association indicate that the underlying burial may have happened during a cool period, as is indicated by a lower mat (-2.58°c ) than at present. however, the conditions are a little milder than those detected for h3 in the galls carboners site, where the mat was 3.72°c lower than nowadays (fig. 4) (lópez-garcía et al., 2014). the interpretation of layers tp06 and tp09, situated chronologically within lgm (fig. 3), and their comparison with other sites of similar chronology seem more plausible. in general, all sites with smallvertebrate studies attributed to lgm are associated with cold climatic fluctuations characterized by mat lower than at present (fig. 4). however, those sites located in central-north and northwestern iberia with a greater oceanic and continental influence, such as el portalón small mammals from lagar velho rockshelter 207 p1 and valdavara-1-lu, have an mat that is more similar to present-day values in the area in comparison with other sites which also fall within lgm, such as our studied layers, maltravieso-chimeneas and l’arbreda cave layers c and b (fig. 4). we also found differences among these sites. whereas in maltravieso-chimeneas and lagar velho tp06 and tp09, the mat is very similar, in l’arbreda cave it is substantially lower (fig. 4). these differences can be explained by the smallmammal associations. according to sans-fuentes & ventura (2000) and lópez-garcía et al. (2010a), the small-mammal associations of the lgm layers of l’arbreda cave are dominated by species with mideuropean requirements such as microtus arvalis and microtus agrestis, along with an abundant representation of microtus oeconomus and a lower representation of apodemus sylvaticus (lópez-garcía et al., 2015). by contrast, the small-mammal association of maltraviesochimeneas is very similar to levels tp06 and tp09 of lagar velho, represented by a combined association of species with mid-european requirements, such as microtus arvalis and microtus agrestis, with others with mediterranean requirements, such as microtus 208 lópez-garcía j.m. et al. (iberomys) cabrerae, together with a relative abundance of apodemus sylvaticus (bañuls-cardona et al., 2012). 5. conclusions our review of the small-mammal material from the lagar velho rockshelter leads to the following conclusions: the species microtus (terricola) lusitanicus was identified during the present study, thus refining the previous identification placed within the duodecimcostatus-lusitanicus group. likewise, microtus arvalis and microtus agrestis were recognized both species being present in the reviewed layers. finally, microtus (iberomys) cabrerae, which had not previously been identified, is added to the taxonomic list. from a taphonomic point of view, although certain degrees of digestion were observed, especially in arvicoline molars, a probable methodological bias in the recovery of the samples, which saw the sediments from the tp layers water-sieved through a 2.5 mm mesh in the field and the sediments underlying the child burial water-sieved through a 1.5 mm mesh in the laboratory, fig. 4 comparison of the benthic 18o isotope curve (modified from lisiecki & raymo, 2005) from 32 to 16 ka with the absolute dating range of the analysed sites and the difference (δ ) with respect to the present-day mean annual temperature (mat) obtained on the basis of the rodent assemblages of various sites. gc: galls carboners; arb: l’arbreda cave; mtv-ch: maltravieso-chimeneas; p1: el portalón; vlu: valdavara-1 lower unit; and chb, tp06 and tp09: the levels of lagar velho studied in the present manuscript. precludes a taphonomic interpretation of the association. this bias could be also affected the representation in the studied small mammals community. the same can be argued regarding the application of quantitative methods to an environmental reconstruction. the small-mammal assemblage suggests the presence of an open forest in the vicinity of the rockshelter, which is consistent with the data previously published based on charcoal and large mammals. although it has been taken with caution, the application of the qualitative method of the bioclimatic model to the rodent assemblage shows the different layers analysed at the lagar velho rockshelter to have a cooler and relatively drier climate than nowadays, marked by more rigorous winter temperatures and slightly milder summer temperatures. in the light of the chronological position of the lagar velho rockshelter (considering the small-mammal association of the studied layers), it can be seen that layers tp06 and tp09 present similar micromammal compositions to all the other sites with small-vertebrate studies that fall within lgm, reflecting cold climatic fluctuations and mean annual temperatures lower than at present. acknowledgements we want to thank prof. joão zilhão for his help and for the revision of the firsts drafts of the manuscript. we also want to thank rupert glasgow for reviewing the english language of the manuscript. in addition, we want to thank dr. e. luzi and an anonymous reviewer for their suggestions that improved the final version of the manuscript. this manuscript is part of a josé castillejo project (cas18/00095) of the spanish ministry of science, innovation and universities. j.m.l.-g and j.d. were supported by a ramón y cajal contract (ryc2016-19386 and ryc-2015-17667, respectively), and m. sanz by a juan de la cierva contract (ijci-201733908) with financial sponsorship from the spanish ministry of science, innovation and universities. references andrews p. (1990) owls, caves and fossils. predation, preservation and accumulation of small mammal bones in caves, with an analysis of the pleistocene cave faunas from westbury-submendip, somerset, uk. the university chicago press, london, pp. 239. andrews, p. (2006) taphonomic effects of faunal impoverishment and faunal mixing. palaeogeogr. palaeoclimatol. palaeoecol., 241, 572-589. angelucci d. (2002) the geochronological context. in: zilhão j., trinkaus e. (eds.), portrait of the artist as a child. the gravettian h man skeleton from the abrigo do lagar velho and its archeological context. ipa (trabalhos de arqueologia, 22), lisbon, 58-91. bañuls-cardona s., lópez-garcía j.m., blain h.-a., canals a. (2012) climate and landscape during the last glacial maximum in southwestern iberia: the small vertebrate association from the sala de las chimeneas, maltravieso, extremadura. c.r. palevol 11, 31-40. beck h. e., zimmermman n.e. mcvicar t.r., vegopolan n., berg a., wood e.f. (2018) present and future köppen-geigerm climate classification maps at 1-km resolution. sci. data., 5, 180214. bencatel j., álvares f., moura a. e. barbosa a.m. (eds.). (2017) atlas de mamíferos de portugal. universidade de évora, portugal, pp. 271. bond g.c., lotti r. (1995) iceberg discharges into the north atlantic on millennial time scales during the last glaciation. science, 267,1005-1010. bronk ramsey c. (2009) bayesian analysis of radiocarbon dates. radiocarbon, 51, 337-360. duarte c. (2002) the burial taphonomy and ritual. in: zilhão j., trinkaus e. (eds.), portrait of the artist as a child. the gravettian human skeleton from the abrigo do lagar velho and its archeological context. ipa (trabalhos de arqueologia, 22), lisbon, 187-201. duarte c., maurício j., pettitt p.b., souto p., trinkaus e., van der plicht h., zilhão j. (1999) the upper early paleolithic human skeleton from the abrigo do lagar velho (portugal) and modern human emergence in iberia. proc. natl. acad. sci. usa 96, 7604-7609. evans e.m.n., van couvering j.a.h., andrews p. (1981) palaeoecology of miocene sites in western kenya. j. hum. evol., 10, 99-116. fernàndez-jalvo y., andrews p., denys c., sesé c., stoetzel e., martín-monfort d., pesquero d. (2016) taphonomy for taxonomists: implications of predation in small mammal studies. quat. sci. rev., 139, 138-157. fletcher w., sánchez-goñi m.a. (2008) orbital and sub-orbital scale climate impacts on vegetation of the western mediterranean basin over the last 48 000 years. quat. res., 70, 451-464. hein a.s, hulton n. r.j., dunai t.j., sugden d.e., kaplan m.r., xu s. (2010) the chronology of the last glacial maximum and deglacial events in central argentine patagonia. quat. sci. rev., 29, 1212-1220. hemming s.r. (2004) heinrich events: massive late pleistocene detritus layers of the north atlantic and their global climate imprint. rev. geophys., 42, rg1005, pp 43. hernández-fernández m., (2001a) bioclimatic discriminant capacity of terrestrial mammal faunas. glob. ecol. biogeogr., 10, 189-204. hernández-fernández m. (2001b) análisis paleoecológico y paleoclimático de las sucesiones de mamíferos del plio-pleistoceno ibérico. phd thesis. universidad complutense de madrid, madrid, 379. hernández-fernández m., peláez-campomanes p. (2005) quantitative palaeoclimatic inference based on mammal faunas. glob. ecol. biogeogr., 14, 39-56. hernández-fernández m., álvarez-sierra m.a., peláezcampomanes p. (2007) bioclimatic analysis of rodent palaeofaunas reveals severe climatic chan small mammals from lagar velho rockshelter 209 ges in southwestern europe during the pliopleistocene. palaeogeogr. palaeoclimatol. palaeoecol., 251, 500-526. ishiwa t., yokoyama y., okuno j., obrochta s., uehara k., ikehara m., miyairi y. (2019) a sea-level plateu preceding the marine isotope stage 2 minima revealed by australian sediments. sci. rep., 9, 6449. kageyama m., combourieu nebout n., sepulchre p., peyron o., krinner g., ramstein g., cazet j.-p. (2005) the last glacial maximum and heinrich event 1 in terms of climate and vegetation around the alboran sea: a preliminary model-data comparison. c.r. geoscience, 337, 983-992. köppen w., geiger r. (1936) handbuch der klimatologie. hansebok, berlin, 588. lisiecki l.e., raymo m.e. (2005) a pliocenepleistocene tack of 57 globally distributed benthic �18o records. paleo 20, pa1003, 1-17. lópez-garcía j.m., blain h.a., allúe e., bañuls s., bargalló a., martín p., morales j.i., pedro m., rodríguez a., solé a., oms f.x. (2010a) first fossil evidence of an “interglacial refugium” in the pyrenean region. naturwissenschaften, 97, 753-761. lópez-garcía j.m., dorado-valiño m., blain h.-a., cuenca-bescós g., ruizzapata m.b., valdeolmillos a., gil-garcía m.j., arsuaga j.l., carretero j.m., de castro j.m.b., carbonell e., ortega a.i. (2010b) palaeoenvironmental and palaeoclimatic reconstruction of the latest pleistocene of el portalon site, sierra de atapuerca, northwestern spain. palaeogeogr. palaeoclimatol. palaeoecol., 292, 453-464 lópez-garcía j.m., blain h.a., cuenca-bescós g., alonso s., vaquero m., alonso, c. (2011) small vertebrates (amphibia, squamata, mammalia) from the late pleistocene-holocene of the valdavara-1 cave (galicia, northwestern spain). geobios, 44, 253-269. lópez-garcía j.m., blain h.a., bennàsar m., alcover j.a., bañuls-cardona s., fernández-garcía m., fontanals m., martín p., morales j.i., muñoz l., pedro m., vergés j.m. (2014) climate and landscape during the heinrich event 3 in southwestern europe: the small-vertebrate association from galls carboners cave (mont-ral, tarragona, north-eastern iberia). j. quat. sci., 29, 130-140. lópez-garcía j.m., soler n., maroto j., soler j., alcalde g., galobart à., bennàsar m., burjachs f. (2015) palaeoenvironmental and palaeoclimatic reconstruction of the latest pleistocene of l’arbreda cave (serinyà, girona, northeastern iberia) inferred from the small-mammal (insectivore and rodent) assemblages. palaeogeogr. palaeoclimatol. palaeoecol., 435, 244-253. moreno-garcía m. (2002) the faunal element in the burial, in: zilhão j., trinkaus e. (eds.), portrait of the artist as a child. the gravettian human skeleton from the abrigo do lagar velho and its archeological context. ipa (trabalhos de arqueologia, 22), lisbon, 139-151. moreno-garcía m., pimenta c.m. (2002) the paleo 210 lópez-garcía j.m. et al. faunal context, in: zilhão j., trinkaus e. (eds.), portrait of the artist as a child. the gr vettian human skeleton from the abrigo d lagar velho and its archeological context. ipa (trabalhos de arqueologia, 22), lisbon, 112-131. palomo j.l., gisbert j., rey j.c. (2007) atlas de los mamíferos terrestres de españa. dirección general para la biodiversidad-secem-secemu, madrid, 586. paupério j., vale-gonçalves h. m., cabral j. a., mira a., bencatel j. (2017) roedores (rodentia), in: bencatel, j., álvares, f., moura, a. e., barbosa, a. m. (eds.), atlas de mamíferos de portugal. universidade de évora, portugal, 39-59. peel m.c., finlayson b.l., mcmahon t.a. (2007) updated world map of the koppen-geiger climate classification. hydrol. earth syst. sci., 11, 16331644. pettitt p.b., van der plicht h., bronk ramsey c., monge soares a.m., zilhão j. (2002) the radiocarbon chronolgy, in zilhão j., trinkaus e. (eds.), portrait of the artist as a child. the gravettian human skeleton from the abrigo do lagar velho and its archeological context. ipa (trabalhos de arqueologia, 22), lisbon, 132138. peyron o., guiot j., cheddadi r., tarasov p., reille m., de beaulieu j.-l., bottema s., andrieu v. (1998) climatic reconstruction in europe for 18,000 yr b.p. from pollen data. quat. res., 49, 183-196. queiroz p.f. (2002) the anthracology of burial, in: zilhão j., trinkaus e. (eds.), portrait of the artist as a child. the gravettian human skeleton from the abrigo do lagar velho and its archeological context. ipa (trabalhos de arqueologia, 22), lisbon, 152153. queiroz p,f., mateus j.e., van leeuwaarden w. (2002) the paleovegetational context, in: zilhão j., trinkaus e. (eds.), portrait of the artist as a child. the gravettian human skeleton from the abrigo do lagar velho and its archeological context. ipa (trabalhos de arqueologia, 22), lisbon, 92-111. reimer p.j., bard e., bayliss a., beck j.w., blackwell p.g., bronk ramsey c., buck c.e., cheng h., edwards r.l., friedrich m., grootes p.m., guilderson t.p., haflidason h., hajdas i., hatté c., heaton t.j., hoffmann d.l., hogg a.g., hughen k.a., kaiser k.f., kromer b., manning s.w., niu m., reimer r.w., richards d.a., scott e.m., southon j.r., staff r.a., turney c.s.m., van der plicht j. (2013) intcal13 and marine13 radiocarbon age calibration curves 0-50,000 years cal bp. radiocarbon, 55, 1869-1887. sans-fuentes m.a., ventura j. (2000) distribution patterns of the small mammals (insectivora and rodentia) in a transitional zone between the eurosiberian and the mediterranean regions. j. biogeogr., 27, 755-764. sommer r.s., nadachowski a. (2006) glacial refugia of mammals in europe: evidence from fossil record. mammal rev. 36, 251-265. zilhão j., almeida f. (2002) the archeological framework. in: zilhão, as a child. the gravettian hu man skeleton from the abrigo do lagar velho and its archeological context. ipa (trabalhos de arqueologia, 22), lisbon, 29-57. zilhão j., trinkaus e. (eds.) (2002) portrait of the artist as a child. the gravettian human skeleton from the abrigo do lagar velho and its archeological context. ipa (trabalhos de arqueologia, 22), lisbon, pp. 609. zilhão j. (2005) burial evidence for social differentiation of age classes in the early upper paleolithic, in: vialou, j., renault-miskowsky, j., patou mathis, m. (dir.), comportements des hommes du paléolithique moyen et supérieur en europe: territoires et milieux. eraul, liège, 231-241. ms. received: december 16, 2020 revised: february 8, 2021 accepted: february 28, 2021 avaiable online: march 15, 2021 small mammals from lagar velho rockshelter 211 212 amq short notes 26_2 zerboni divito monegato available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 25 (2), 2012, vii ix report on the aiqua 2013 summer school "the impact of volcanic eruptions on landscape, environment and human settlements (multidisciplinary perspectives: geological, archaeological and biological)” mauro a. di vito1, giovanni zanchetta2, sandro de vita1, paola romano3, pierfrancesco talamo4 1 istituto nazionale di geofisica e vulcanologia, sezione di napoli osservatorio vesuviano, naples, italy 2 dipartimento di scienze della terra, università degli studi di pisa, italy 3 dipartimento di scienze della terra, università degli studi federico ii di napoli, italy 4 soprintendenza speciale per i beni archeologici di napoli e pompei, naples, italy corresponding author: m.a. di vito <mauro.divito@ov.ingv.it> abstract: a brief summary of the activities carried out during the aiqua 2013 summer school held from the 27th to 31st may 2013 at the vesuvius observatory. the course provided an opportunity for students and researchers from different academic backgrounds to present and discuss topics of great scientific and human interest concerning the impact of volcanic eruptions on people and the landscape, starting from actual examples in the vicinity of naples. keywords: volcanology, archaeology, climate, botany, palaeontology, pedology. the aiqua 2013 summer school, held at the vesuvius observatory (naples headquarters of the ingv) from 27th to 31st march 2013, received an encouraging level of participation in terms of both subscribers and speakers. notwithstanding the economic difficulties that affect young people in particular, twenty-seven enrolled: young researchers, phd students and undergraduates from the length of italy, and one from switzerland. the speakers, all research workers of international standing who took part with enthusiasm and without remuneration, provided classes of high educational and scientific calibre. the texts of these lessons, in the form of short scientific articles, were published in a journal entitled miscellanea (di vito et al., 2013) and distributed beforehand to teachers and students; they may be found online at www.ingv.it. this collection, thanks to keen participation from all the speakers and fig. 1 field trip – avella stop. mauro di vito is discussing the impact of past eruptions on the landscape. the professionalism of the ingv editorial staff, was made available online prior to the start of the course and has also been printed, with financial support from the vesuvius observatory. the lessons all shared a common denominator, an emphasis upon how an integrated multidisciplinary approach can enable the reconstruction of the human and territorial impact of extreme events such as volcanic eruptions and related phenomena, and an understanding of how the many peoples who have inhabited the naples region – of different cultures and modes of social organization – have reacted to these events. despite the results obtained by much specialist research in this area, there are still few multidisciplinary studies in which diverse disciplines have worked in close and continuous collaboration. the field excursions (figs. 1 and 2) involved concrete examples of recently-studied cases, demonstrating how the concepts explained during the lectures have been applied to resolve problems which posed difficulties for individual specialists – for whom familiarity with the routine application of their own procedures leads to the risk of missing information essential for the comprehension of the lecturer title mauro a. di vito a geological perspective on the study of human responses to volcanic activity: examples in campania mauro a. di vito somma vesuvius: history of eruptions and their territorial impact roberto isaia tephrostratigraphy of phlegraean fields volcanism during the last 15 ka sandro de vita structural geology and volcanological evolution of the isle of ischia monica piochi, angela mormone petrology and isotopic geochemistry in tephrostratigraphical correlations: examples from neapolitan volcanoes daniela giampaola, giuliana boenzi effects on human life of volcanic activity: archaeological evidence from central naples adele bertini role of volcanic activity in quaternary climate change vincenzo amato holocene climatic variations: examples of morpho-sedimentary change inferred from the archaeotephro-stratigraphic record of campania (41°n, south italy) biagio giaccio chronology and ecological factors regarding the middle palaeolithic – upper palaeolithic transition in europe in the light of the campanian ignimbrite eruption (39 ka) giovanni zanchetta syneruptive and intereruptive debris-flow on the campanian apennines: a geological perspective fabio terribile genesis, evolution and properties of volcanic soils in the campanian countryside gaetano di pasquale transformations of wooded and grass-covered landscapes in campania: information from the study of wood and charcoal in natural and anthropic contexts filippo terrasi the importance of 14c dating in chronostratigraphy and palaeoenvironmental work giovanni zanchetta continental isotope-based palaeoclimatology and the climatic evolution of the mediterranean christophe morhange holocene relative sea level changes: an insight from volcanological and archaeological data aldo cinque geomorphological evolution of the sorrento peninsula valleys after the vesuvian eruption of ad 79 aldo marturano pompeii and the insula of the chaste lovers: natural phenomena, transformations of the terrain and interactions with the manmade environment elda russo ermolli pollen analysis: an important tool for reconstructing palaeolandscapes and palaeoclimates pierfrancesco talamo campanian cultural sequence and volcanic events from the neolithic until the end of the bronze age paola romano reconstructing ancient coastlines in naples from geological and geomorphological evidence elena laforgia impact of volcanic eruptions in the area north of naples: new data from recent excavations costanza gialanella effects on human life of volcanic activity: the archaeological evidence from the isle of ischia valentino di donato palaeontology’s contribution to the understanding of archaeological contexts: methods and campanian case-studies laura sadori using plant micro-remains for reconstructing palaeoenvironments and evaluating the effects of human activity: the lakes of lazio marco pacciarelli exceptional development of settlements from neolithic to iron age on soils of volcanic origin in tyrrhenian calabria table 1. topics covered during the aiqua 2013 summer school field leaders field trip mauro a. di vito, gianni zanchetta, pierfrancesco talamo, giuseppe vecchio, nicola castaldo monteforte (distal sequences in the apennines); avella (alluvial fans at the apennine-campania plain junction); s. paolo belsito (reconstruction of huts of the nola early bronze age village); cimitile (early christian churches and the ad 472 debris-flow) mauro a. di vito, sandro de vita, pierfrancesco talamo, aldo marturano, paola romano, aldo cinque, costanza gialanella, maria paola guidobaldi, paola miniero, grete stefani pompeii (house of the chaste lovers); herculaneum (the pre-ad 79 coastline); phlegraean fields (baia castle, lake averno and monte nuovo); pozzuoli (roman marketplace) table 2. field trips held during the aiqua 2013 summer school di vito a. et al. viii phenomena observed and their effects on humans and the environment. the fundamental purpose of the course was to stimulate debate and cooperation between the diverse branches of knowledge involved and initiate the formation of professionals able to meet the new challenges that the humanistic and natural sciences must face in order to make real progress in the understanding of past phenomena and guide an informed and sustainable use of the land. in tables 1 and 2 the topics covered and relevant speakers are listed – all of whom are warmly thanked for their contribution to the success of this initiativeand the field trips, held during the course. references di vito m.a., de vita s. (eds) 2013. compendio delle lezioni, scuola estiva aiqua 2013, l’impatto delle eruzioni vulcaniche sul paesaggio, sull’ambiente e sugli insediamenti umani – approcci multidisciplinari di tipo geologico, archeologico e biologico. napoli 27 – 31 maggio 2013, miscellanea ingv, 18:1-136. fig. 2. field trip – the excursion ended at the baia castle in the western campi flegrei. ms. received: september 6, 2013 final text received: september 6, 2013 aiqua 2013 summer school ix x base corso porta reno, ferrara (northern italy): a study in the formation processes of urban deposits mauro cremaschi1 & cristiano nicosia1 1 dipartimento di scienze della terra “a. desio”, università degli studi di milano, via mangiagalli 34, 20133, milano, italy. (mauro.cremaschi@unimi.it; cristiano.nicosia@unimi.it) corresponding author: m. cremaschi <mauro.cremaschi@unimi.it> abstract: cremaschi m. & nicosia c., corso porta reno, ferrara (northern italy): a study in the formation processes of urban deposits. (it issn 0394-3356, 2010) the city of ferrara (emilia romagna, northern italy) is located on the left bank of the branch of the medieval channel of the po river, the “po of ferrara”. this paper presents the results of the geoarchaeological study of the stratigraphic sequence exposed during excavations in corso porta reno, located at an intermediate position between the palaeo-po alluvial ridge and the adjacent floodplain. the area, also referred to as the “san romano complex”, was excavated between 1981 and 1984, revealing an exceptionally well-preserved sequence, comprising occupation deposits and structural remains dated between the 8th and the late 13th century ad. geoarchaeological observations in the field and the micromorphological study of soil thin sections allowed the reconstruction of the natural and anthropic processes involved in the formation of the site stratigraphic sequence. this is characterised by an alternating succession of anthropogenic units (trampled domestic deposits, layers deriving from construction, destruction and/or refurbishing of buildings, materials from decantation within anthropic structures) and of natural alluvial deposits (light-coloured sandy layers often showing cross laminations, linked to a crevasse-splay context active during the human dwelling). the waterlogged nature of the site, the rapid rate of sedimentary accretion, and the sealing of the sequence due to the construction of a brick house in the 13th century avoided the well-stratified deposit to be heavily homogenized by bioturbation or reworked by later human activities. the model envisaged at corso porta reno could partly explain the strong vertical accretion of urban deposits during the middle age and provide a possible mode of formation for thick “dark earth” sequences in medieval cities in active alluvial settings. riassunto: cremaschi m. & nicosia c., corso porta reno, ferrara (italia settentrionale): studio dei processi di formazione di depositi urbani. (it issn 0394-3356, 2010) l’articolo presenta i risultati dello studio geoarcheologico della sequenza stratigrafica esposta durante gli scavi archeologici in corso porta reno a ferrara, in un’area posta tra il dosso del paleo-po e la piana alluvionale adiacente. il sito, conosciuto anche come “complesso di san romano”, fu scavato tra il 1981 e il 1984 e restituì depositi d’abitato ed elementi strutturali datati tra l’viii ed il xiii secolo d. c., in eccezionali condizioni di conservazione. lo studio geoarcheologico sul campo, integrato da quello di sezioni sottili, ha permesso di ricostruire i processi naturali e le attività antropiche responsabili per la formazione della sequenza stratigrafica del sito. essa è caratterizzata dall’alternanza di unità antropogeniche (depositi di origine domestica soggetti a calpestio, unità derivanti dalla costruzione e/o dalla distruzione di edifici, sedimenti decantati all’interno di strutture negative) e di depositi alluvionali naturali (strati sabbiosi di colore chiaro, spesso con laminazioni incrociate, legati ad un ambiente di lobo di rotta attivo durante la frequentazione antropica del sito). le condizioni di saturazione idrica, il rapido accrescimento sedimentario e la costruzione di un edificio in mattoni nel xiii secolo hanno evitato che la stratificazione originaria del sito venisse omogeneizzata dalla bioturbazione o sconvolta da attività antropiche nei secoli successivi. il modello delineato in corso porta reno potrebbe in parte spiegare la forte crescita verticale delle stratificazioni urbane durane il medioevo e fornire un modello per la formazione di spesse “terre nere” in città poste in ambienti alluvionali attivi. keywords: ferrara; po river; urban archaeology; “dark earths”. parole chiave: ferrara; fiume po; archeologia urbana; “terre nere”. il quaternario italian journal of quaternary sciences 23(2bis), 2010 volume speciale 373-386 1. introduction this paper reports the geoarchaeological study of a stratigraphic sequence exposed in corso porta reno in ferrara (emilia-romagna region, northern italy) – (fig. 1). at this site, also referred to as the “san romano complex”, archaeological excavations were carried out between 1981 and 1984 (gadd & ward-perkins, 1991; visser travagli, 1992; visser travagli & ward-perkins, 1981). unlike many major italian towns, ferrara is not a city of roman origin, but was settled as byzantine castrum in the 7th century ad (visser travagli & wardperkins, 1981) on the left bank of the branch of the po river active during the early medieval period (the “po of ferrara”; bondesan et al., 1995). due to its position, the city acted as an important trade centre connecting the po plain and northern italy to the adriatic sea and consequently flourished since the middle ages becoming a main centre in the renaissance (visser travagli & ward-perkins, 1981). ferrara is located at the apex of the delta plain of the po river (castiglioni & pellegrini, 2001), where the distributary channels are highly unstable and likely to switch frequently their course. a major avulsion, known as the “rotta di ficarolo” (mid-11th century – end of the 12th century ad), caused the main channel of the po river to migrate to the north, reaching the present position, c. 5 km north of the modern town of ferrara (veggiani, 1985; bondesan et al., 1995). after the “rotta di ficarolo”, the po of ferrara and its two eastward branches (po of volano and po of primaro) stayed active and able to generate floods, also due to the input from the apennine streams, until the beginning of the 16th 374 m. cremaschi & c. nicosia fig. 1 geomorphological setting of the city of ferrara: (1) alluvial ridge; (2) uncertain trace of alluvial ridge; (3) palaeo-river channel, level of the surrounding plain; (4) crevasse splay; (5) ancient crevasse channel; (6) canals; (7) present-day river levee (after bondesan et al., 1995). inquadramento geomorfologico della città di ferrara: (1) dosso fluviale; (2) tracce incerte di dosso fluviale; (3) paleo-alveo al livello della pianura circostante; (4) lobo di rotta; (5) antico canale di rotta; (6) canali; (7) argine fluviale attuale (da bondesan et al., 1995). century ad. at this time, the po of ferrara was cut off from the active hydrographic network of the area by human intervention (bondesan et al., 1995). the position of the po river channel crossing ferrara during the medieval period is still evident in the modern topography of the town (stefani, this volume). the river flowed, similarly to most of the water courses in this part of the po plain, on top of a sandy alluvial ridge delimited by natural levees (bridge, 2003), about 4–5 m above the surrounding floodplain (fig. 1). the latter consists of highly organic clays and peats, as observed by cremaschi (1992) in the archaeological excavations at piazzetta castello, an area inhabited only after the 13th century ad north of the po (fig. 1). crevasse splays originating from the left side of the river channel were common and can be detected from the elevation models published by bondesan et al. (1995). the site of the archaeological excavation at corso porta reno is located at the lower fringe of the po river ridge, in an intermediate position between the latter and the floodplain, possibly at the outer margin of a crevasse-splay fan. the peculiar position of the site allowed an excellent preservation of the archaeological deposits. wood remains, pertaining to a series of superimposed structural phases were exposed during excavations. these phases were dated by means of the associated material culture between the 8th and the late 13th century. based on gadd & ward-perkins (1991) and visser travagli & ward-perkins (1981), the earliest structures exposed at corso porta reno have been interpreted as open-sided temporary sheds, followed by huts with a raised living space above an open-sided ground floor used for storage. a later phase was characterised by timber-framed houses, possibly with an upper storey for domestic activities, with evidence of repeated destruction and reconstruction. lastly, in the late 13th century, the last timber-framed house was replaced by a brick building. all of the above-mentioned structural phases are characterised, according to the excavators, by an alternating sequence of: “floors [...] of blue-grey silt and [...] accumulated tread layers interleaved with patches of clean silt reflooring” (gadd & ward-perkins, 1991, p. 108); or of “a series of very pure silt deposits separated by charcoal-rich tread layers” (visser travagli & ward-perkins, 1979/80, p. 59); or again it was stated that “these [...] houses underwent refurbishment, indicated by [...] the gradual build-up of tread and reflooring layers” (gadd & ward-perkins, 1991, p. 112). making use of soil micromorphology and field observations, the present study is focused on deciphering the sedimentary processes that established the stratigraphic sequence, characteristic of a peri-fluvial urban environment. in particular, this investigation is aimed at identifying the formation processes of both the light-coloured layers, previously interpreted as man-made floors, as well as of the dark anthropogenic layers. 2. materials and methods samples were collected from the stratigraphic profile (sect. 2) exposed during the 1982 excavation and subsequently integrated by further observations in 1983 (figs. 2, 3). sampling has been aimed especially at interpreting the sequence from the stratigraphic and 375corso porta reno, ferrara (northern italy): a study ... sedimentary standpoint, avoiding anthropic structures. thin sections were manufactured from air-dried, undisturbed and oriented blocks according to standard methods (murphy, 1986). for thin section description the terminology of stoops (2003) was employed, together with the concept of “soil microfabric type1” (hereafter smt) (macphail & cruise, 2001; goldberg & macphail, 2006) 3. results 3.1 the stratigraphic section the studied stratigraphic section is delimited at both sides by brick walls (figs. 2, 3, 4). the stratigraphic units observed in the field are hereafter briefly described: 3.1.1 lower layers they consist of two sub-units: (a) planar organic loamy sand layers, massive or discontinuously laminated with mottles (5y 4/1dark gray) (samples 9, 3 – fig. 3); (b) laminated organic-rich loam layers (5y 2.5/1, black – 10yr 3/1, very dark gray) rich in charcoal, wood fragments, vegetal residues; they also include large brick fragments and discontinuous lenses of subrounded lithorelictcs with sandy texture. intercalated to these layers there are lenses of sediments rubefied and hardened due to exposure to fire (samples 1, 4 – fig. 3). 3.1.2 ditch, cesspit and associated deposits in the stratigraphic profile of fig. 3, the lower layers are cut by a cesspit related to the timber-framed house. the basal deposit of the ditch consists of peat (sample 10), rich in wood fragments, sealed by a sandy layer (sample 8). the cesspit is filled by charcoal and organic rich layers in the lower portion, then by alternating sand and organic-rich sub-units, described below. these alternations are associated with the timber-framed house deposits. 3.1.3 timber-framed house related deposits moving upward in the profile in fig. 3, we observe a series of planar lenticular layers, concave at the base, as they seal the depression inherited from the underlying ditch. these layers include the structures, the horizontal beams, and the posts pertaining to the timber-framed houses. two sub-units of contrasting lithology were observed: (a) medium to fine grained loamy sands, (2.5 yr 5/2 greyish brown); planar laminations, cross laminations and small ripples are often put in evidence by diagenetically oxidised laminae (sample 5). these sub-units do not display evidence of pedological alteration and are devoid of any archaeological material. (b) loam to loamy silts (from 2.5 y 3/2, very dark greyish brown, to 5 y 4/3, olive), massive or displaying discontinuous planar lamination (samples 2 and 6). they include charcoal, wood fragments and archaeological materials (mammal bones and brick 1 each smt corresponds to a set of observed micromorphological characteristics which can occur within different thin sections and are labelled with progressive numbers. variations within the same smt are indicated by a small letter (for example smt 3, 3a). 376 fig. 2 left: location of the corso porta reno excavation in the city of ferrara. right: excavation plan with position of the studied profile; (a) modern (19th century) structures (walls, cistern, well), (b) late-13th century brick-house walls; (c) limits of excavated area. a sinistra: posizione del sito di corso porta reno nella città di ferrara. a destra: pianta di scavo con posizionamento del profilo esaminato; (a) strutture moderne (xix secolo): muri, cisterna, pozzo; (b) muri in mattone della case della fine del xiii secolo; (c) limiti dell’area scavata. fig. 3 the studied stratigraphic profile: (a) top soil; (b) alternating lenses of sand (dotted) and loamy organic layers (light grey); (c) peat deposits and wood; (d) wood posts, lenses reddened by burning and brick fragments. numbers on the profile indicate location of thin sections: 1, 9, 3, 4: lower layers; 10, 8: ditch, cesspit and associated deposits; 2, 5, 6: timber-framed house related deposits; 7: top soil. il profilo stratigrafico esaminato: (a) top soil; (b) lenti di sabbia (puntinato) alternate a strati organici a tessitura franca (grigio chiaro); (c) depositi torbosi e legni; (d) pali lignei, lenti rubefatte per scottatura e frammenti di mattone. i numeri sul profilo indicano la posizione delle sezioni sottili: 1, 9, 3, 4: strati inferiori; 10, 8: fossato, latrina e relativi depositi; 2, 5, 6: depositi relativi alle strutture abitative in legno; 7: top soil. m. cremaschi & c. nicosia 377 fragments). sediments rubefied and hardened by exposure to fire are common, particularly on top of these lenses. in the top part, the stratification dips slightly towards the east and the loamy sandy layers (sub-unit a) increase in number and markedly in thickness. 3.1.4 topsoil the topsoil is separated from the underlying unit by an erosional discontinuity. the topsoil consists of silty-clay with common brick and tile fragments; it has mottles (2.5 y 4/2, dark greyish brown; 7.5 yr 4/4 brown/dark brown), and a weakly separated angular blocky structure with common voids (sample 7 fig. 3). 3.2 thin section analysis tables 1, 2, 3 and 4 provide a brief definition of the observed fabrics and of microstructures, followed by the description of the organic and anthropogenic components, of the groundmass and of the pedofeatures for each smt occurring in a thin section2. an outline of the main characteristics of each soil microfabric type (smt) identified during thin section analysis is provided below. smt 1 : sands and silts, often showing sedimentary structures (graded fabric, laminations), almost completely devoid of archaeological materials. it is interpreted as the characterizing microfabric of po flood deposits, not perturbed by anthropogenic intervention. it has been observed in thin sections 1, 3 (lower units) and 5 (timber-framed house-related deposits). thin section 9 (lower units) is characterised by smt 1a, consisting of alluvial sandysilts reworked by biological activity. smt 2: composed almost exclusively of anthropogenic materials (charcoal, mammal and fish bones, excrements, ash, vitrified phytoliths, pottery) with coarser inclusions showing strong horizontal orientation. this microfabric derived from the trampling of deposits produced by domestic activit ies (hearths, food preparation, dumping of waste etc). the presence of intercalated thin fine-grained lenses and discontinuous laminations testifies the periodic reworking by waters of the exposed dwelling surfaces, probably during floods. smt 2 has been observed in thin sections 1 (lower units) and 6 (timber-framed house-related deposits). smt 3: characterised by the admixture of reworked aggregates deriving from both alluvial layers and from occupation deposits, with components distributed chaotically. interpreted as the result of the reworking of underlying stratigraphic units during phases of building construction, destruction and/or refurbishing. excrements and secondary phosphates deriving from cesspit reworking are common. smt 3 has been fig. 4 the studied stratigraphic profile during excavation, with the alternate sequence of lightand darkcoloured layers. to the left the brick wall of the late 13th century ad house can be seen along with wooden structural elements. il profilo esaminato durante le fasi di scavo archeologico. si noti l’alternanza di strati a colorazione chiara e scura. sulla sinistra sono visibili il muro in mattoni della casa della fine del xiii secolo e degli elementi strutturali lignei. 2 abundance of fabric units in tables 1, 2, 3 and 4 is expressed according to stoops (2003) as follows: very few (<5%), few (5-15%), common (15-30%), frequent (30-50%), dominant (50-70%). corso porta reno, ferrara (northern italy): a study ... 378 observed in samples 4 (lower units), 2 and 6 (timber-framed house-related deposits), 7 (topsoil). smt 3a has been assigned in thin section 6 to a sub-unit showing traces of trampling and compaction. smt 3b derived from the weathering and bioturbation of smt 3 and was observed in thin section 7 (topsoil). smt 4: silty-clay textured material with common plant remains showing strongly-expressed parallel horizontal orientation. intercalated lenses that can be siltyclayey or made up by phosphates or ash. frequent archaeological components (charcoal, bones and fishbones, excrements). interpreted as the outcome of stagnation within the ditch accompanied by the occasional dumping of waste. it has been observed in thin sections 8 and 10 (ditch, cesspit and associated deposits). 3.2.1 lower layers (thin sections 1, 9, 3, 4 – table 1) thin section 1 is an example of the sequence interpreted by gadd & ward-perkins (1991) and visser travagli & ward-perkins (1979/80) as the alternation of dark “thread” layers and yellowish “reflooring”. under the microscope (fig. 5a), the sample is made up of 215mm thick levels of well sorted laminated sandy silts and silty clays, sometimes showing graded fabric (smt 1), intercalated to 2-5mm-thick trampled occupation layers (smt 2). the presence of sedimentary structures (fig. 5c) allows us to interpret the material labelled as smt 1 as a series of thin alluvial levels, natural in origin, rather than as man-made reflooring layers. only one of these layers appears devoid of sedimentary structures (thin section 1), possibly due to table 1 lower layers: description of thin sections 1, 3, 4, 9 and associated soil microfabric types (smt). unità inferiori: descrizione delle sezioni sottili 1, 3, 4, 9 e relativi soil microfabric types (smt). m. cremaschi & c. nicosia 379 table 2 ditch, cesspit and associated deposits: description of thin sections 8 and 10 and associated soil microfabric types (smt). fossato, latrina e relativi depositi: descrizione delle sezioni sottili 8 e 10 e relativi soil microfabric types (smt). fig. 5 lower layers, thin section 1. the scanned thin section (a) shows the alternating sequence of laminated alluvial sands and silty clays characterised smt 1 (c, 20x) and of occupation deposits characterised by smt 2 (b, 20x). in the latter, the strong parallel horizontal orientation of coarser constituents and the massive microstructure are linked to trampling and compaction. unità inferiori, sezione sottile 1. la sezione sottile scannerizzata (a) evidenza l’alternanza di sabbie/ argille limose alluvionali caratterizzate da smt 1 (c, 20x) e di depositi di frequentazione caratterizzati da smt 2 (b, 20x). in questi ultimi l’iso-orientamento delle componenti grossolane e la microstruttura massiva sono legate al calpestio e alla compressione. corso porta reno, ferrara (northern italy): a study ... 380 table 3 timber-framed house related deposits: description of thin sections 2, 5, 6 and associated soil microfabric types (smt). depositi associati alle strutture abitative in legno: descrizione delle sezioni sottili 2, 5, 6 e relativi soil microfabric types (smt). m. cremaschi & c. nicosia lowish (plane polarized light ppl) aggregates, optically isotropic under crossed nichols, containing phytoliths and occasional small fragments of bone, are interpreted as carnivore/omnivore excrements (macphail 2000), possibly of human origin (fig. 6a). orange-yellowish (ppl) optically isotropic orthic and disorthic nodules, often associated with vivianite crystal intergrowths, are also present in thin sections 4 and 2, and can be interpreted as fe-phosphatic nodules (fig. 6b). these nodules, the crystal intergrowths and the excrements derive most likely from the destruction or rebuilding of cesspits and latrines. several phases of cesspit construction and refurbishing have indeed been recorded during archaeological excavations (gadd & ward-perkins, 1991). 3.2.2 ditch, cesspit and associated deposits (thin sections 8, 10 – table 2) thin sections 8 and 10 are mainly composed of elongated plant fragments, among which leaves are frequently recognisable (figs. 7a, 7b smt 4 microfabric). these vegetal residues show a horizontal parallel orientation, locally resulting in a platy microstructure. discontinuities within plant residue levels are marked by ash-rich or phosphatic 1-2mm thick discontinuous layers (especially in thin section 8), or by continuous, laminated or graded thin silty-clay lenses (thin section 10 – fig. 7c). the lenses most likely correspond to finegrained mineral layers, intercalated to the organic materials through deposition in a low-energy environment. we interpret this portion as the deposition in standing waters inside the ditch cut from the base of the timberframed house-related deposits (fig. 3). along the sides of the ditch dumping of ashes, cess material and construction rubble (observed in thin section 8) took place. 3.2.3 timber-framed house-related deposits (thin sections 2, 5, 6 – table 3) micromorphology shows that the deposits associated to the timber-framed house consist of alternation of materials deriving from trampled occupation layers and from building destruction and refurbishing. these 381 table 4 top soil: description of thin section 7 and associated soil microfabric type (smt). top soil: descrizione della sezione sottile 7 e relativo soil microfabric type (smt). trampling disturbance (fig. 5a). the occupation layers with smt 2 microfabric are rich in plant residues and in anthropogenic components. these consist of large quantities of charcoal of all sizes, burned bone, ash aggregates and vitrified phytoliths (deriving from the melting of biogenic opal courty et al. 1989), symptomatic of materials from the functioning and maintenance of domestic hearths. fishbones are widespread in all thin sections from occupation deposits, suggesting the exploitation of the nearby river po for subsistence, even though detailed studies on the faunal remains are not yet available. the massive microstructure and the horizontal orientation of coarser constituents (charcoal, elongated plant material, bones) indicate that these levels were subject to trampling and compaction (fig. 5b). evidence of flood reworking on the exposed dwelling surfaces were also observed, such as rare finegrained lenses and the sorting of charcoal fragments toward the top of each layer. thin sections 3 and 9 are from sandy-silt layers almost devoid of anthropogenic inclusions. thin section 3 is interpreted as a natural alluvial deposit (smt 1), confirming the occurrence of floods during this phase. the origin of the sandy silts in thin section 9 is more diff icult to establish, since the sample is strongly reworked by biological activity, as shown by the channel microstructure and the widespread passage features (smt 1a). anthropogenic components such as charcoal, burned bone and excrement fragments are however very rare in this thin section. thin section 4 is characterised by smt 3 microfabric, consisting of an admixture of different materials, with a chaotic organisation of the components and no trace of trampling or compaction (fig. 6). this microfabric type encompasses reworked aggregates of the occupation layers described above (smt 2 microfabric), together with frequent subrounded aggregates of alluvial sediments (smt 1 – fig. 6a). this material can thus be interpreted as the outcome of the destruction by digging and the reworking of underlying deposits. this process resulted in a chaotic mixture of aggregates and fragments from different stratigraphic units. orange-yelcorso porta reno, ferrara (northern italy): a study ... 382 fig. 6 lower layers, thin section 4. smt 3 derives from the reworking of underlying deposits with inclusions of cesspit materials. in the scanned thin section (a) arrows point at the reworked aggregates from underlying alluvial layers (smt 1 material). the occurrence of carnivore/omnivore excrement fragments (b, 40x ppl) and of fe-phosphatic nodules (c, 20x ppl) testifies to the input of materials from cesspits. unità inferiori, sezione sottile 4. smt 3 deriva dal rimaneggiamento dei depositi sottostanti, con immissione di materiale derivante da latrine. nella sezione sottile scannerizzata (a) le frecce indicano aggregati rimaneggiati provenienti dalle unità alluvionali sottostanti (materiale con smt 1). frammenti di escrementi di carnivori/onnivori (b, 40x ppl) e noduli ferro-fosfatici (c, 20x ppl) testimoniano la presenza di materiali derivanti da latrine. fig. 7 ditch, cesspit and associated deposits, thin section 10. in the scanned thin section (a) it is possible to observe the layering that characterises the filling of the ditch. (b): layered plant remains and charcoal, characteristic of smt 4 (20x ppl). (c): detail of one of the fine sediment lenses intercalated to the organic layers in smt 4 (40x ppl). fossato, latrina e depositi associati, sezione sottile 10. nella sezione sottile scannerizzata (a) è possibile osservate la stratificazione che caratterizza il riempimento del fossato. (b): residui vegetali e carboni stratificati, tipici di smt 4 (20x, ppl). (c): dettaglio di una delle lenti di sedimento fine intercalate agli strati a componenti organiche in smt 4 (40x ppl). m. cremaschi & c. nicosia deposits bear traces of reworking by flood water flows. thin section 2 provides another example of a layer deriving from digging and reworking of underlying deposits during building destruction or refurbishing. the layer shows the chaotic disposition of coarse organic and anthropogenic constituents (smt 3) and the frequent occurrence of reworked sandy-silty aggregates of alluvium (smt 1 material). destruction and refurbishing of buildings followed by occupation was observed also in thin section 6. here, the admixture of reworked materials from underlying units shows traces of trampling and compaction, such as the parallel horizontal orientation of coarser constituents and a massive microstructure (smt 3a). in the same thin section, there are traces of further deposition of smt 3 material and then again of the formation of a trampled occupation layer. thin section 5 pertains to silty-sands interpreted as a natural alluvial deposit, as shown by the presence of internal laminations and graded fabric. the field observation of planar laminations, small ripple forms and cross-laminations fits with the microscopic evidences. 3.2.4 topsoil (thin section 7 – table 4) this layer predates the construction of the brick house at the end of the 13th century and contains abundant coarse construction debris, such as brick and tiles. thin section 7 is a chaotic admixture of materials, deriving from the destruction and refurbishing of buildings, and has a weakly developed channel microstructure. the latter suggests that biological reworking by earthworms took place during a phase of topsoil formation, during which the surface was dry and stable (smt 3b). 4. discussion the site of corso porta reno in ferrara offered an important opportunity to investigate the modes of formation and accretion of an urban stratigraphic sequence in a medieval town. in cities throughout europe, archaeological excavations have often exposed deposits referred to as “dark earths” (see carver, 1987; brogiolo et al., 1988; yule, 1990; macphail et al, 2003; galinié, 2004). dark earth is a term used to designate thick, seemingly homogeneous and dark-coloured deposits rich in archaeological material, generally ascribed to the post-roman period. since the early 1980s (macphail 1981, 1983), geoarchaeological and especially soil micromorphological analyses have demonstrated that in many cases dark earth represents an oncecomplex deposit that has been heavily homogenised by pedological processes, especially bioturbation and weathering (macphail, 1994; macphail & goldberg, 1995). geoarchaeological analyses revealed that many diverse, superimposed activities and processes are responsible for the formation of urban dark earths. these correspond, for example, to the repeated dumping of waste (cammas, 2004), cultivation (cremaschi, 1992), human dwelling, stabling of animals and decay of insubstantial buildings (macphail & goldberg, 1995), among others. due to human reworking, to the action of rodents, earthworms, enchytraeds, plant roots, and weathering of organic and earth-based construction materials, any macroscopic original sedimentary structure and stratification has been obliterated. at corso porta reno the persisting waterlogged conditions and the rapidly aggrading sedimentary environment prevented the deposit from being disturbed and homogenized by soil fauna or by roots. in a later phase, the presence of the topsoil (sample 7) witnesses the interruption of sedimentary processes, replaced by weathering. the whole sequence was then sealed in the 13th century ad by the construction of a brick house that remained in place until its destruction in the last war (gadd & wardperkins, 1991). all these factors enabled the original stratification of the deposit to be preserved. macroand micro-morphological investigation indicates that the anthropic accretion at the site is mostly the outcome of: (a) trampling of domestic deposits (smt 2), generated by the activity of fireplaces as also shown by the occurrence of surfaces reddened by burning. flood reworking occasionally took place (see below); (b) construction, destruction or refurbishing of buildings (smt 3) marked by digging of underlying deposits (post-holes, pits, cesspits); (c) sediment settling inside negative structures (ditch, cesspits) producing organic levels with intercalated fine-grained sediment lenses (smt 4). within such structures occasional dumping of construction rubble, ash and cesspit material could take place, as well as the filling by fluvial sediments. the natural alluvial deposits are intercalated to anthropogenic ones mainly in the phase of the timberframed house, their thickness increasing markedly towards the top of the sequence. alluvial deposits can be classified into two types: (a) layers of well sorted medium-fine sand or silty-sand with cross-laminated structures, deposited in crevasse splays, due to floods breaching from the po river channel (smt 1); (b) organic-rich silt and fine sand, including charcoal, wood fragments deriving from decantation and redistribution of materials in a waterlogged environment (fine-grained lenses in smt 2). these deposits are often intercalated to anthropogenic surfaces related to trampling, recording water content fluctuation, possibly on a seasonal base. in the study area, floods are mainly expected during the autumn and early spring. these stratigraphic information fit well with the observations made during the archaeological excavation, which indicate that before the brick house of the late 13th century, buildings were mostly two-storey timber houses, with an open ground floor. fireplaces at the ground floor were frequent and often rebuilt and moved. the houses underwent several phases of rebuilding, refurbishing and even destruction by fire (gadd & ward-perkins, 1991; visser travagli & wardperkins, 1979/80). not all of the “clean” silty and sandysilty layers appear to be man-made reflooring layers (see § 1). based on field and microscopic evidence, these layers could rather be interpreted as natural alluvial deposits intercalated to occupation or “thread” layers. the presence of flood beds intercalated to occupation deposits has important bearings for the understanding of the urban stratigraphy. it shows that in cities located close to active rivers (e.g. on top of active alluvial ridges or in floodplains) part of the accretion can be linked to the episodic input of alluvium or to deposition and redistribution in standing waters. 383corso porta reno, ferrara (northern italy): a study ... alluvium and occupation deposits will normally be subject to weathering, homogenisation by synand post-depositional bioturbation and human reworking (e.g. cultivation, digging, construction of buildings), unless these processes are hampered. while in need of further research, this model could partly account for the strong vertical accretion and for the formation of homogeneous “dark earths” in medieval cities within active fluvial environments. 5. conclusions the geoarchaeological investigation of the stratigraphic sequence of the corso porta reno site, in ferrara, has proven useful for both archaeologicalhistorical and geomorphologic purposes. it elucidated the natural and anthropic processes leading to the formation of thick urban stratigraphic sequences. in doing so, it revealed that accretion derives from the superimposition of trampled domestic occupation deposits and activity surfaces, of chaotic layers deriving from building construction activities, of organic-rich facies formed within negative structures with standing waters, and of flood deposits from the po of ferrara. given the proximity to the alluvial ridge, the alluvial deposits, with their generally sandy texture and cross-laminated sedimentary structures, can be explained in a crevasse splay context, which has been observed in all the units of the stratigraphic sequence, except for unit “topsoil” (unit a in fig. 3, see § 3.1.4). the waterlogged nature and the strongly aggrading environment of the site avoided the effects of bioturbation, allowing this exceptional sequence to be very well preserved and readable. it therefore seems clear that at the site the vertical growth of the urban deposit resulted from the interplay between alluvial sedimentation close to the po ridge and repeated episodes of human occupation, possibly with a seasonal character. the model of formation envisaged in corso porta reno should be investigated for urban sites with dark earthlike deposits located in an active alluvial setting. the results of the study of the corso porta reno stratigraphic profile, integrated with data from archaeological excavations, showed that, in the early medieval period structure types, construction techniques and modes of occupation were adapted to a peri-fluvial environment. the change in the style of the sedimentation towards the top of the sequence, highlighted by the bioturbated and well-drained character of the topsoil (fig. 3), seems to be correlated with an important change in the sedimentary environment of the urban area. this corresponds to the shift from a setting subject to seasonal floods to one in which sedimentary processes appear to be somewhat under control. this latter process might have an anthropic origin, like the increased control of levees, but might also be related to the major change in the hydrography of the po floodplain associated with the “rotta di ficarolo” avulsion (mid-11th century – end of the 12th century ad veggiani, 1985; bondesan et al., 1995). this avulsion led in fact to the progressive abandonment of the channel of the po of ferrara, which flowed through the city until that moment. 6. acknowledgements for the involvement in the corso porta reno excavation mauro cremaschi wishes to express his gratitude to dr. a. m. visser travagli. 7. references bondesan m., ferri r., stefani m. 1995 rapporti fra lo sviluppo urbano di ferrara e l’evoluzione idrografica, sedimentaria e geomorfologica del territorio. in: visser travagli a. m. (ed.), ferrara nel medioevo. topografia storica e archeologia urbana, grafis edizioni, casalecchio di reno, 27-42. bridge j. s. 2003 rivers and floodplains: forms, processes and sedimentary record. wiley-blackwell, malden, ma, u.s.a. brogiolo g.p., cremaschi m., gelichi s. 1988 processi di stratificazione in centri urbani (dalla stratificazione “naturale” alla stratificazione “archeologica”). archeologia stratigrafica dell’italia settentrionale, 1. edizioni new press, como, 219-226. carver m.o.h. 1987 the nature of urban deposits. in: schofield j., lynch r. (eds.) urban archaeology in britain, cba research report 61, london, 926. castiglioni g. b., pellegrini m. (eds.) 2001 note illustrative della carta geomorfologica della pianura padana. suppl. geografia fisica e dinamica quaternaria, iv, 1-204. courty, m. a., goldberg p., macphail r.i. 1989 soil micromorphology in archaeology. cambridge manuals in archaeology, cambridge university press, cambridge. cremaschi m. 1992 caratteristiche geoarcheologiche della successione stratigrafica posta in luce nello scavo archeologico di piazzetta castello. in: gelichi s. (ed.), ferrara prima e dopo il castello. testimonianze archeologiche per la storia della città, spazio libri editori, ferrara, 58–65. gadd d., ward perkins b. 1991 the development of urban domestic housing in north italy. the evidence of excavations on the san romano site, ferrara . the accordia research papers, 2, 105–127. galinie h. 2004 l’expression “terres noires”, un concept d’attente. in: verslype l., brulet r. (eds.), terres noires dark earth. actes de la table-ronde internationale tenue à louvain-la-neuve les 09 et 10 novembre 2001, universitè catholique de louvain, louvain-la-neuve. goldberg p., macphail r. i. 2006 practical and theoretical geoarchaeology. blackwell publishing, new york. macphail r.i. 1981 soil and botanical studies of the “dark earth”. in: jones m. & dimbleby g.w. (eds.), the environment of man: the iron age to the anglo-saxon period. british series, 87. british archaeological reports, oxford, 309–331. macphail r.i. 1983 the micromorphology of dark earth from gloucester, london and norwich: an analysis of urban anthropogenic deposits from late roman to early medieval periods in england. in: bullock p., murphy c.p. (eds.), soil micromor384 m. cremaschi & c. nicosia phology. ab academic publishers, berkhamsted. macphail r.i. 1994 the reworking of urban stratigraphy by human and natural processes. in: hall a.r. & kenward h.k. (eds.), urban-rural connexions: perspectives from environmental archaeology. oxbow monographs, 47, oxford, 13–43. macphail r. i. 2000 soils and microstratigraphy: a soil micromorphological and microchemical approach. in: lawson a.j. (ed.), potterne 1982-5: animal husbandry in later prehistoric wiltshire, wessex archaeology report, 17, salisbury, 47–71. macphail r. i., goldberg p. 1995 recent advances in micromorphological interpretations of soils and sediments from archaeological sites. in: barham a. j., macphail r. i. (eds.), archaeological sediments and soils: analysis, interpretation and management, institute of archaeology, london, 1–24. macphail r. i., cruise j. 2001 the soil micromorphologist as a team player – a multyanalytical approach to the study of european microstratigraphy. in: goldberg p., holliday v. t., reid ferring c. (eds.), earth sciences in archaeology, kluwer academic/plenum publishers, 241–267. macphail r.i. galinié h., verhaeghe f. 2003 a future for dark earth?. antiquity, 77 (296), 349–358. murphy c.p. 1986 thin section preparation of soils and sediments. ab academic, berkhamsted. veggiani a. 1985 il delta del po e l'evoluzione della rete idrografica padana in epoca storica. in: atti della tavola rotonda: il delta del po, sezione geologica. accademia delle scienze dell'istituto di bologna, 39–68. visser travagli a. m., ward perkins b. 1979/80 archeologia urbana a ferrara: scavi nel comparto di s. romano, 1981. bollettino annuale dei musei ferraresi, 9/10, 55–58. visser travagli a. m. 1992 lo scavo nel comparto di s.romano: analisi di un’ esperienza archeologica. in: gelichi s. (ed.), ferrara prima e dopo il castello. testimonianze archeologiche per la storia della città. spazio libri editori, ferrara, 248–259. stoops g. 2003 guidelines for analysis and description of soil and regolith thin sections. soil science society of america, madison, wi. yule b. 1990 the “dark earth” and late roman london. antiquity, 64, 620–628. 385 ms. ricevuto il 2 agosto 2010 testo definitivo ricevuto il 16 ottobre 2010 ms. received: august 2, 2010 final text received: october 16, 2010 corso porta reno, ferrara (northern italy): a study ... palaeoenvironmental considerations on the latest pleistocene and holocene micromammals from the grotta dei pipistrelli (hyblaean mountains, sicily, italy). maria teresa spena 1 , paolo agnelli 2 , jessica di maita 1 , rosario grasso 1 , leonardo salari 3 1 dipartimento di scienze biologiche, geologiche ed ambientali, università degli studi di catania, italy. 2 museo di storia naturale dell’università degli studi di firenze, italy. 3 dipartimento di scienze della terra, “sapienza” università di roma (collaboratore esterno), italy. corresponding author: l. salari <leonardosalari@virgilio.it> abstract: the eulipotyphla and rodentia remains from the grotta dei pipistrelli in sicily (italy), a key region for the historical reconstruction of the quaternary climates and environments of the central mediterranean basin, are described and discussed. three 14c radiometric dating display that the fossil remains were accumulated during the last glacial maximum (lgm) and in the middle holocene. taphonomic observations show that the small mammal remains probably come from asio otus pellets. both the micromammal assemblages are oligotypical and similar to each other. however, the relative abundance of apodemus sylvaticus suggest temperate-warm and humid climatic conditions, in both lgm and middle holocene. the frequency variations in the recognized taxa indicate that the palaeoenvironment was slightly more wooded in the lgm than during the middle holocene. these results complement previous studies and allow the outline of a composite landscape with wooded areas interrupted by open spaces (grassland, steppe), shrubland and rocky areas, where the water supply provided by anapo river and its tributaries was enough to support a rich vegetation cover, particularly in the lgm. keywords: quaternary, small mammals, central mediterranean, pantalica nature reserve, palaeoenvironment. available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 34 (2), 2021, 187-200 1. introduction sicily is located in a key geographic position for understanding quaternary climate and environmental changes in the central mediterranean basin (fig. 1a). recent studies on the quaternary vertebrate assemblages of sicily allowed the identification of up to 7 faunal complexes (=fcs) (e.g., bonfiglio et al., 2003; masini et al., 2008; petruso et al., 2008; marra, 2013). faunal changes reflected by fcs are primarily related to the alternation of isolation and land-connections of sicily with the italian peninsula. the fcs are connected to dispersal events, followed by isolation phases, which induced processes of endemism (e.g., the middle pleistocene dwarf elephants and giant dormices; bonfiglio et al., 2003; masini et al., 2008; petruso et al., 2008; marra, 2013). the latest pleistocene assemblages are represented by the castello fc and include a scarcely diversified mammal fauna, without archaic endemites, similar to southern italy one, and with homo sapiens (see bonfiglio et al., 2003; masini et al., 2008; petruso et al., 2011a; marra, 2013). although the castello fc was correlated with the last pleniglacial lateglacial period (masini et al., 2008; petruso et al., 2008, 2011a), there is actually no faunal assemblages known from the last pleniglacial, except for a few remains of equus hydruntinus regalia, 1907 from grotta san teodoro, dated 23-21 ka cal. bp (catalano et al., 2020). in sicily, palaeoclimate and palaeoenvironment of the last pleniglacial, around the last glacial maximum (=lgm; 20±2 ka cal. bp, see antonioli & vai, 2004; masini et al., 2008), are known by the sediments, pollen and microcharcoal of pergusa lake (zanchetta et al., 2007; sadori et al., 2008). from the holocene of sicily, the large mammals are well known (e.g., tagliacozzo, 1993; villari, 1995; burgio et al., 2005), but only few studies exist on small mammals (e.g., surdi, 2008; lópez-garcía et al., 2013). the holocene environmental and climatic changes are known based mainly on several pollen and charcoal studies (bertolani marchetti et al., 1984; sadori et al., 2008, 2013; noti et al., 2009; tinner et al., 2009; calò et al., 2012; forgia et al., 2013). the micromammal assemblages from grotta dei pipistrelli (literally, cave of the bats), near sortino (syracuse, sicily, italy), offer the possibility to fill these gaps, at least partly. between 2014 and 2018, numerous micromammal remains have been collected in the talus https://doi.org/10.26382/amq.2021.02 188 spena m.t. et al. area of this cave (spena et al., 2017; salari et al., 2019). the now investigated non-volant micromammal remains belong to eulipotyphla, crocidura sicula miller, 1900, and to two rodentia taxa, microtus savii (de sélys-longchamps, 1838) group and apodemus sylvaticus (linnaeus, 1758). according to three 14 c dating, the micromammal remains were accumulated during the marine isotope stage (=mis) 2, in the lgm, and in two events of middle holocene referred to the atlantic chronozone, neolithic cultural phase (salari et al., 2019). spena et al. (2017) reported a preliminary list of volant and non-volant small mammal fossils collected from 2014 to 2016. salari et al. (2019) described the bat remains collected from 2014 to 2018 and discussed some chronological and palaeoecological implications. nine taxa of chiroptera have been identified: rhinolophus ferrumequinum (schreber, 1774), r. euryale blasius, 1853, r. mehelyi matschie, 1901, myotis myotis (borkhausen, 1797), m. blythii (tomes, 1857), m. capaccinii (bonaparte, 1837), myotis cf. m. mystacinus (kuhl, 1817), plecotus cf. p. auritus (linnaeus, 1758) and minfig. 1 a) mediterranean basin; b) location of grotta dei pipistrelli near sortino (syracuse, sicily, italy); c) map of the natural reserve “pantalica, valle dell’anapo e torrente cava grande” area (from istituto geografico militare, ed. 4 1968, map of italy at the scale 1:25000, sheet 274, iii, n.o., sortino, redrawn and modified); black circle: grotta dei pipistrelli; d) plan of the cave. 189 pleistocene-holocene micromammals from pipistrelli cave (sicily) iopterus schreibersii (kuhl, 1819). the aim of this work on the fossil assemblages from grotta dei pipistrelli is to describe the non-volant micromammal remains and discuss the palaeoenvironmental reconstructions, comparing them with other sicilian and southern tyrrhenian sea area fossil assemblages. 2. the cave grotta dei pipistrelli is located on the eastern side of the hyblaean mountains, in the nature reserve “pantalica, valle dell’anapo e torrente cava grande” (south-east sicily; figs. 1b-c; henceforth pantalica nature reserve). the area is characterized by a natural plateau, deeply engraved by the anapo river and the calcinara stream. pantalica nature reserve (over 37 kmq) has been awarded in 2005 as unesco world heritage site for its history, archaeology, speleology and landscape (unesco, 1992-2019). it consists of various natural and semi-natural environments (riparian forest, woodland, shrubland, grassland, steppe) along with cultivated land (minissale et al., 2007; aa.vv., 2009), which are essential habitats for many invertebrate and vertebrate communities. as described in detail by spena et al. (2013, 2017), grotta dei pipistrelli opens on a rocky wall overhanging the calcinara stream, about 10 m from the left bank of the watercourse, in the miocene “calcari di siracusa” formation. the karst cavity has a sub-horizontal development with a 7.3% west-east average slope and it has been explored for about 260 m (fig. 1d): between the entrance of the cave, at 234 m above sea level (=a.s.l.), and the ending point (253 m a.s.l.). at the entrance, the cave has a large opening that quickly constricts into a funnel that enters into a first room. a gallery links the room to a large hall called “sala del guano”, with a 15 m high vault consisting of three domes, which currently hosts huge bat colonies. the karst cavity continues with a series of galleries and small dome halls and it is then interrupted in a large terminal hall, where it ends in a duct enclosed by a thick layer of coarse detritus. the cave hosts very large colonies of chiroptera and it represents the biggest nursery roost of the region (spena et al., 2013; ferrante et al., 2018). from 2012 to date, grotta dei pipistrelli is the only systematically monitored bat cave in sicily (spena et al., 2013, 2017; ferrante et al., 2018). several ossiferous breccia containing many small vertebrate remains (birds, insectivores, rodents and mostly bats) have been observed on the right wall of the talus close to the entrance since 1996. the terrain close to the right wall contains many fossils of small vertebrates and some bone remains of large mammals, too. sediments of a gallery yelded a portion of elephant tusk, attributable to palaeoloxodon mnaidriensis (adams, 1874). in the talus close to the entrance, ossiferous breccia are spread on the surface of the right wall, from a couple of decimeters above the walking surface up to about 2 meters in height. in the ground near the right wall, the bone remains below the walking surface were found up to a few decimetres of depth. the walking surface does not contain fossil remains; the soil over 30/40 cm deep is sterile. between 2014 and 2018, several campaigns of fossil remains collection in three closely associated areas of the talus were conducted. samples were collected on the right wall, from the soil at the base of the same wall, and from the ground on a rocky ledge with guano at about 40 cm over the aforementioned soil. three 14 c dating have been carried out on micromammal bones by the centre for applied physics, dating and diagnostics of salento university in lecce (italy) and provided the following datings: 18,062±120 years bp (20,305-19,600 cal. bc) for the ossiferous breccia on the right wall, 6,472±45 years bp (5,5135,339 cal. bc) for the bone remains collected in the soil at the base of the right wall, and 6,242±45 years bp (5,314-5,060 cal. bc) for the bone remains collected on the rocky ledge with guano (salari et al., 2019). 3. materials and methods the sampling area, i.e. the right wall of the talus and the soil close to it, was associated with an assigned baseline and subdivided into 25 sections of 1 m wide, in order to relate each sample of soil and breccia with its position along the wall and its depth. each sample was then assigned a progressive number and recorded with its section coordinates and depth. the samples were collected from three closely associated areas: on the surface of the right wall (about 9 m in length and 0.24/2.00 m in heigth; sections from 4-5 to 12-13), from the soil at the base of the same wall (between 2/3 and 30/40 cm of depth from the walking surface, for 6 m in length and 40/60 cm in wide; sections from 8-9 to 13-14) and from a rocky ledge with guano (just over a square meter between 0 and 4/5 cm in depth, sections 11-12 and 15-16). the 12 calcareous breccia samples were dissolved in acetic acid, then filtered, using sieves of 1.60 and 0.63 mm mesh size and neutralized in water in order to stop further dissolving. the 13 soil samples (9 at the base of the right wall and 4 collected on the rocky ledge with guano) were screen washed in the laboratory and then dried. in the rocky ledge with guano, only bat remains were found. the micromammal remains were compared with osteological material, both fossil and recent, from the department of sciences of “roma tre” university and in the department of earth sciences of “sapienza” rome university. morphological and morphometric investigations follow repenning (1967), niethammer & krapp (1978), nappi (2001), amori et al. (2008) and ronninger (2009). the analyses were carried out with a nikon smz -u stereoscopic microscope in the department of sciences of “roma tre” university; measurements and pictures were taken with a leika dfc290 system using the leica application suite software. taphonomic observations were conducted following the methodologies of andrews (1990) and fernández-jalvo et al. (2016), in order to investigate the possible agents responsible for the accumulation of the fossil remains. for the taphonomic remarks and taxonomic identi fications, the analyses were focused on cranial elements (cranium, mandible, isolated teeth), and on humeri and femora. dental terminology is: i: upper incisors; c: upper canine; p: upper premolars; m: upper molars; lower teeth are denoted by lowercase letters. for each taxon, both the number of identified specimens (nisp) and the minimum number of individuals (mni) is provided. the mni was calculated based on the most frequently represented cranial element, with distinction of right and left body side; this result was integrated with the analysis of the age and the dimensional characters of other skeletal elements. the environmental reconstructions, based on the ecology and geographical distribution of the corresponding current taxa (niethammer & krapp, 1978; aa.vv., 2008; amori et al., 2008), include chiroptera (lanza & agnelli, 2002; agnelli et al., 2008), although this group was focus of other paper (salari et al., 2019). the authors (particularly jdm, rg and mts) collected the analysed material. the fossil remains are currently deposited in the department of biological, geological and environmental sciences of catania university. the final collocation and cataloguing will be decided in agreement with the direction of pantalica nature reserve. therefore, the inventory numbers of the samples given in this paper are provisional. 4. systematic notes order eulipotyphla waddell, okada & hasegawa, 1999 family soricidae fisher, 1817 genus crocidurinae wagler, 1832 crocidura wagler, 1832 crocidura sicula miller, 1900 material: one splanchnocranium (figs. 2a-b) and 2 mandibles of which one sub-entire from the late pleistocene breccia; 2 fragmented mandibles from the holocene soil. description and remarks: the splanchnocranium has the typical morphology of the genus crocidura, in particular for the unpigmented teeth and for the presence of three pairs of upper unicuspid teeth, the first of which is larger than the equally-sized second and third ones (repenning, 1967; aloise et al., 2008). furthermore, the p4 shows an angular and squared parastyle, and the dorsal edge of the cingulum is undulated, not straight. these features allow to attribute the above 190 spena m.t. et al. fig. 2 grotta dei pipistrelli (sicily, italy): crocidura sicula, splanchnocranium (c4s5-6): a) labial view, b) occlusal view; microtus savii group, left mandible (c5s5-5): c) lingual view; d) m1 and m2 in occlusal view; apodemus sylvaticus: e) right mandible (c5s10-11) in lingual view; f) left maxilla fragment (c25s5-6) in occlusal view. scale bars: 2 mm. fossil arvicolinae teeth with characters similar to those of the extant m. (t.) savii are known from deposits dating back to the middle-late part of the middle pleistocene (kotsakis, 2008; kotsakis et al., 2020). therefore, at moment it is preferable to use the taxon “microtus savii group”, also pending solid morphometric data to discriminate between the two species and in agreement with the paleontological works that identify the late pleistocene and holocene sicilian remains of arvicolinae of subgenus terricola as m. savii group. remains attributed to m. savii group occur in sicily since the san teodoro fc (second, but not terminal, part of the late pleistocene) (bonfiglio et al., 2003; masini et al., 2008; petruso et al., 2011a; marra, 2013) and are recorded in several lateglacial and holocene sites (tagliacozzo, 1993; burgio et al., 2005; martini et al., 2007; surdi, 2008; lópez-garcía et al., 2013). today, the arvicoline of the m. savii group are restricted mainly to the italian peninsula, but are also found in south switzerland and south-east france (contoli et al., 2008), preferring open environments, such as grasslands, uncultivated and cultivated areas, and avoiding dense woodlands (contoli et al., 2008; capizzi, 2013). in sicily, the savi’s pine vole, or better m. nebrodensis, is distributed up to 1800 m a.s.l., but prefer hilly areas and plains, particularly in the open and temperate environments, grassland and steppes, avoiding too hard, arid and stony soils and dense woods with rich undergrowth (cagnin & grasso, 1999; sarà, 2008b). in the hyblaean mountains, it is recorded in the southern side (siracusa, 1997), while in the central and eastern areas seems to be absent (sarà, 2008b). however, it was recently found in some localities of the eastern side (g. di natale and m. nanzarelli, in litteris), also within the boundaries of the pantalica nature reserve (unpublished data by mts and rg). family muridae illiger, 1811 subfamily murinae illiger, 1811 genus apodemus kaup, 1829 subgenus sylvaemus ognev & vorobiev, 1923 apodemus (sylvaemus) sylvaticus (linnaeus, 1758) material: 18 maxillaries mostly fragmented, 9 mandible fragments, 11 m1, 4 m2, 4 m3, 11 m1, 4 m2, 2 m3, 2 humeri and 2 femuri from the late pleistocene breccia; 15 maxillaires, some of which are fragmented, 26 mostly fragmented mandibles (fig. 2e-f), 3 m1, 1 m2, 1 m3, 1 m1, 4 m2, 1 m3 and 2 femora from holocene soil. description and remarks: the morphologic features of fossil remains are typical of the genus apodemus, in particular m1 with four roots, m1 with two roots and six main cusps in two rows and m1 and m2 with accessory cusps on the labial side (capizzi, 2008). the distinct and well-developed tubercle t3 of the m2, the three-rooted m3, and the tubercles of the lower molars that form relatively complex patterns, are typical of the sylvaemus subgenus (capizzi & filippucci, 2008a). furthermore, the m1 with the confluent tubercles t4 and t7 and the m2 with the developed tubercle t9 are features attributing the above specimens to a. sylvaticus, the wood mouse (niethammer, 1978; capizzi & filippucci, 2008b). some upper and lower molars have absent or incomplete specimen to c. sicula, the sicilian shrew, and to exclude other extant (contoli, 2008) and extinct (kotsakis, 1986, 2008) italian species of the genus. as for the mandible, the shape of this skeletal element and of the lower teeth of the sicilian shrew and of the etruscan pygmy shrew, suncus etruscus (savi, 1822), are very similar. however, both the sizes (length of cheekteeth: 5.94 mm; length m1-m3: 3.87-3.96 mm) and biochronological reasons (s. etruscus reaches sicily only in the late holocene; petruso et al., 2011a) exclude the occurrence of the etruscan pygmy shrew in the grotta dei pipistrelli assemblages. c. sicula occurs in sicily since the san teodoro fc (recorded as crocidura cf. c. sicula, see bonfiglio et al., 2003; masini et al., 2008; petruso et al., 2011a; marra, 2013). remains referable to c. sicula are recorded in some lateglacial and holocene sites of sicily (tagliacozzo, 1993; burgio et al., 2005; surdi, 2008; lópez-garcía et al., 2013). the sicilian shrew is a mediterranean endemic species limited to the sicilian and maltese archipelagos (sarà, 2008a). it is currently commonly widespread up to 1600 m a.s.l., both in woodland and less arid scrubland and in environments with herbaceous and shrubby vegetation (cagnin & grasso, 1999; zanca & sarà, 2008). it is also recorded in the hyblaean mountains (zanca & sarà, 2008; aprile et al., 2010). order rodentia bowdich, 1821 family cricetidae fischer, 1817 subfamily arvicolinae gray, 1821 genus microtus schrank, 1798 subgenus terricola fatio, 1867 microtus (terricola) savii (de sélys-longchamps, 1838) material: 1 splanchnocranium, 2 maxillaries, 6 mandible fragments (fig. 2c-d), 6 m1, 7 m2, 8 m3, 14 m1, 9 m2, 7 m3, 1 humerus and 1 femur from the late pleistocene breccia; 3 splanchnocrania, 21 mostly fragmented mandibles, 1 m1, 5 m2, 8 m3, 24 m1, 15 m2, 11 m3 and 1 humerus from holocene soil. description and remarks: the morphology of the m1, with seven triangles and the not triangular-shaped anterior loop, is typical of the microtus genus (amori & capizzi, 2008). the anteroconid complex of this tooth shows broadly confluent t4 and t5 lobes, forming the so-called pitymyan rhombus, peculiar of the terricola subgenus (chaline et al., 1988; nappi & contoli, 2008). furthermore, the m3 is of simplex type, the anterior loop of m1 is wide, extensive and few constricted, and the anteroconid complex is very short, squat and asymmetric. these features allow to refer the above specimens to m. savii group (curcio et al., 2005; contoli et al., 2008; piras et al., 2010; locatelli et al., 2011; petruso et al., 2011b). according to recent biomolecular studies, the extant savi’s pine vole of sicily should be elevated to the rank of full species, microtus nebrodensis (minàpalumbo, 1868) (bezerra et al., 2016; amori & castiglia, 2018). although these biomolecular works have estimated the divergence between m. savii and m. nebrodensis at about 0.6-1.0 ma (latest early pleistocene middle part of the middle pleistocene), the first occurrence of 191 pleistocene-holocene micromammals from pipistrelli cave (sicily) roots, a humerus has an unfused proximal epiphysis, and a femur has an unfused distal epiphysis. therefore, these latter specimens belonged to immature individuals. according to recent biomolecular studies, the sicilian population of a. sylvaticus would be genetically isolated and therefore could represent a different taxon (amori & castiglia, 2018; loy et al., 2019). apodemus cf. a. sylvaticus occurs in sicily since the san teodoro fc (bonfiglio et al., 2003; masini et al., 2008; petruso et al., 2011a; marra, 2013), and it is also recorded, sometime as a. sylvaticus, in some lateglacial and holocene sites (tagliacozzo, 1993; burgio et al., 2005; surdi, 2008; lópez-garcía et al., 2013). nowadays, a. sylvaticus is distributed throughout western europe, northern africa, sicily and other western mediterranean islands (niethammer, 1978; capizzi & filippucci, 2008b). adaptable and opportunistic species, the wood mouse frequents environments with shrub cover, and its optimal habitat is the forest, where the tree cover offers shelter from predators and availability of food for a good part of the year (tellería et al., 1991; montgomery, 1999; marsh & harris, 2000; capizzi & filippucci, 2008b). in sicily, the species occurs up to 1800 m a.s.l., preferring forests and mediterranean maquis, and avoidings arid and dry environments (cagnin & grasso, 1999; sarà, 2008c). it is also recorded in the hyblaean mountains (siracusa, 1997; sarà, 2008c; aprile et al., 2010). 5. taphonomic remarks the non-volant micromammal remains recovered from grotta dei pipistrelli comprise 279 taxonomically identified specimens, belonging to at least 79 individuals (tab. 1), and, in addition, over 200 isolated incisors referable to small-sized rodents. the micromammal assemblages are composed of disarticulated cranial and postcranial remains. isolated teeth are the most numerous elements, followed by fragmented maxillae and mandibles. the relative abundance of these skeletal elements and their fragmentation can be attributed to the destructive action of predators (andrews, 1990; fernández-jalvo et al., 2016), but also to post-depositional processes (andrews, 1990; salari, 2014) and/or to methods of sampling and processing in the laboratory (salari, 2014; salari et al., 2019). fossil remains show different colours from havana white to orange ochre and dark brown: predominantly havana white with some calcium carbonate concretions from the late pleistocene breccia, mostly orange ochre with rare specimens tending to dark brown from the holocene soil. the modifications observed on the teeth concern the reduction or removal of the enamel along the half height in m. savii group molars, and a loss of shininess or enamel reduction at the crown-root junction in a. sylvaticus molars. the incisors of the two rodents, particularly those isolated, display loss of shininess all over the tooth or enamel retraction on the tip leaving the dentine exposed and rounded. a significant percentage of the analysed fossil remains (ca. 15%) shows these peculiar preservations caused by digestion (andrews, 1990; fernández-jalvo et al., 2016), indicating that the bones and teeth were accumulated by predators. considering the molars only (tab. 2), the very high percentage of teeth without alteration shows that the main agent responsible for the accumulation was probably a “category 1” predator, with a light capability for modification. according to fernández-jalvo et al. (2016), “category 1” for the molars includes nocturnal predatory birds, such as tyto alba (scopoli, 1769), asio flammeus (pontoppidan, 1763), asio otus (linnaeus, 1758) and bubo lacteus temminck, 1820. tyto alba prefers to hunt along the edges of woods, it is a generalist and opportunistic predator catching the prey in the nearby surroundings (andrews, 1990; fernández-jalvo et al., 2016). asio flammeus generally hunts in the meadows and wetlands close to coastal plains, it is an opportunistic predator that preferably feeds on arvicolines (andrews, 1990; fernández-jalvo et al., 2016). asio otus usually hunts in open environments, it is a selective predator that mostly prey the arvicolines (andrews, 1990; fernández-jalvo et al., 2016). these three strigiforms are part of the italian avifauna, including sicily (galeotti, 2003; ientile & massa, 2008) and pantalica nature reserve (aa.vv., 2009, and unpublished data), and possibly were it throughout the latest pleistocene and middle holocene. instead, b. lacteus is a bird of prey distributed through most of sub-saharan africa (andrews, 1990). considering the incisors only, the modifications observed are mostly on the tip, indicating that the teeth were retained in the jaws during digestion (andrews, 1990; fernández-jalvo et al., 2016). this, combined with the percentages showing different degrees of digestion (tab. 2) suggest that the main agent responsible for the accumulation was probably a “category 2” predator. this category, for the incisors, includes a. otus, b. lacteus, strix nebulosa forster, 1772 and bubo scandiacus (linnaeus, 1758) (fernández-jalvo et al., 2016). both s. nebulosa and b. scandiacus are species distributed in 192 spena m.t. et al. tab. 1 grotta dei pipistrelli (sicily, italy): number of identified specimens (nisp) and minimum number of individuals (mni) of taxa identified, and their percentage ratios. https://en.wikipedia.org/wiki/sub-saharan_africa higher latitudes and absent in the mediterranean basin (cramp, 1985). only during the colder stages of the late pleistocene these strigiforms reached southern europe, but s. nebulosa has been never recorded beyond the north-east italy (tyberg, 2008), while b. scandiacus reached also southern italy, but not sicily (petruso et al., 2008; tyberg, 2008). thus, taking into account all these considerations on the degrees of digestion on the molar and incisor surfaces and the habits of the nocturnal predatory birds, we assume that the long-eared owl, a. otus, was the main agent responsible for the accumulation of the analysed remains. the long-eared owl as the assumed selective bird of prey usually hunts in open environments (andrews, 1990; fernández-jalvo et al., 2016), so arvicoline remains would be overestimated, and their relative frequency in the environment could be lower than in the pellets. however, several exceptions in which the percentages of arvicolines in the current a. otus pellets are lower than those of the murines, are recorded in italy (e.g., casini & magnani, 1988; siracusa et al., 1996; castioni et al., 1998; cecere et al., 2013). in particular, siracusa et al. (1996) showed that in the diet of the long -eared owl from sicily the main prey is m. savii at roccapalumba (500 m a.s.l., near palermo), while at linguaglossa (1400 m a.s.l., on the etna volcano) the main prey is a. sylvaticus. in this last site, the bone remains of the murid species are about twice the amount of those of m. savii, with percentages similar to those of the strix aluco (linnaeus, 1758) pellets of the same area (siracusa et al., 1996). the latter bird of prey is a generalist predator (andrews, 1990; fernandez-jalvo et al., 2016). thus, in different environments a. otus sometimes orients its predation on different preys according to the availability of the territory (siracusa et al., 1996). it cannot be excluded that, because the low biodiversity in the hyblaean plateau in the times analyzed here, a. otus behaved as a flexible and non-selective predator. 6. discussion 6.1. palaeoclimatic and palaeoenvironmental considerations according to the three radiometric dating, the micromammal assemblages from grotta dei pipistrelli come from two distinct chronological horizons: one referred to the lgm and, therefore, attributable to the castello fc, and the other to the middle holocene. all identified small mammal taxa (tab. 1) are still part of the extant sicilian fauna (aa.vv., 2008; amori et al., 2008) and nowadays occur in the pantalica nature reserve (tab. 3). both latest pleistocene and middle holocene assemblages are oligotypicals and similar to each other. it seems appropriate to specify that, among eulipotyphla and rodentia, only erinaceus europaeus linnaeus, 1758, crocidura cf. c. sicula, m. savii group and apodemus cf. a. sylvaticus occur in sicily during the latest pleistocene (bonfiglio et al., 2003; masini et al., 2008; petruso et al., 2011a; marra, 2013). in the early holocene, arvicola amphibius linnaeus, 1758 and glis glis linnaeus, 1766 first occur, but are so far recorded only in northwestern sicily (petruso et al., 2011a). the other species of the current sicilian small mammal fauna reached the island in the late holocene, voluntarily or involuntarily brought by humans (masseti, 2002; petruso et al., 2011a), while a. amphibius becomes extinct in the 193 pleistocene-holocene micromammals from pipistrelli cave (sicily) tab. 2 grotta dei pipistrelli (sicily, italy): number and percentages of teeth showing different degrees of digestion. tab. 3 list of non-volant small mammals that currently occur within the natural reserve “pantalica, valle dell’anapo e torrente cava grande” (aa.vv., 2008, 2009, and unpublished data). e. europaeus, crocidura cf. c. sicula, microtus savii group and apodemus cf. a. sylvaticus occur in sicily since late pleistocene, g. glis from the early holocene, s. etruscus, e. quercinus, m. musculus and r. rattus only from the recent holocene (petruso et al., 2011a). region (catalisano & sarà, 1995). furthemore, e. europaeus and g. glis are not currently included in the usual diet of a. otus (see sarà, 1990; capizzi & luiselli, 1998; riga & capizzi, 1999; sergio et al., 2008). thus, the three taxa of micromammals from grotta dei pipistrelli include all, or almost all, of the potential mammalian prey available for a. otus in sicily in the times examined. taking into account these considerations, the habitat preferences of each taxon (see 4. systematic notes) and their percentages (tab. 1), the taphonomic observations (see 5. taphonomic remarks) and the current non-volant micromammal fauna of the pantalica nature reserve area (tab. 3), the landscape inferred from the analysed assemblages seems to be rather similar to the present, with woodlands alternated with large clearings and bushes. the frequencies, particularly of the rodents, indicate a palaeoenvironment slightly more wooded in the lgm (a. sylvaticus dominant species) than in the middle holocene (m. savii increases and a. sylvaticus decreases). despite the limited amount of taxa, these results are sufficiently in agreement with previous studies on the bats that suggested an environment prevalently wooded during the lgm and progressively open in the middle holocene (salari et al., 2019). adding the data of chiroptera to those of nonvolant micromammals, there is a greater number of taxa (tab. 4) and it is possible to reduce any biases due to the assumed selectivity of the predator. according to salari et al. (2019), the bat assemblages are essentially autochthonous thanatocoenoses, coming mainly from the natural accumulation of animal bones that roosted and died in the cave. some ecological and biogeographical features of bats are summarised in table 5. the ecological features of all the taxa recovered in grotta dei pipistrelli allow the outline of a composite landscape near the cave, with wooded areas interrupted by open spaces (grassland, steppe), shrubland and rocky areas. even in this case, the palaeoenvironment seems to be more wooded in the lgm than in the middle holocene. indeed, the small mammals of woods and forests are dominant in the lgm, more numerous than the taxa indicanding open spaces and various or mixed environments together (fig. 3). in the middle holocene, the taxa indicating woods and forests are still dominant, but they decrease together with those of various or mixed environments, to the advantage of the open spaces taxa (fig. 3). bat assemblages with dominant m. myotis and/or m. blythii, accompanied by m. schreibersii, auxiliary species, and m. capaccinii and rhinolophids, accidental species, are typical mediterranean associations and would point to relatively warm climate conditions in the region (salari et al., 2019). this, combined with the abundance of a. sylvaticus compared to m. savii group (tabs 1 and 4), suggests that sicily (or at least this area of south-east sicily) kept temperate-warm and humid climatic conditions even during the lgm. global holocene warming is reflected by the increase of clearly thermophilous species, such as r. mehelyi and m. blythii, and by the disappearance of plecotus cf. p. auritus (tab. 4). 6.2. comparisons with other fossil assemblages of sicily and the southern tyrrhenian sea temperate-warm climatic conditions during the lgm in the hyblaean mountains would disagree with the indications suggested by planktonic foraminiferal assemblages of marine sedimentary successions. these unicellular organisms are very sensitive to the water masses conditions where they live and suggested that during the last pleiniglacial the surface waters were on average about 4-6 °c colder in the sicilian channel and around 8 -9 °c in the southern tyrrhenian sea compared to present (sbaffi et al., 2001; hayes et al., 2005; incarbona et al., 2010). according to the fossil pollen record and the ratio of oxygen isotopes in the sediments of pergusa lake (674 m a.s.l.), in central sicily, the vegetation around the lgm was characterized by the scarce presence of trees, while the herbaceous and shrubby flora (asteraceae and chenopodiaceae), indicative of an open environment of steppe or semi-steppe, was quite common (zanchetta et al., 2007; sadori et al., 2008). however, the lateglacial reforestation showed that the surrounding of pergusa lake played an important role in preserving plant biodiversity, including some mesophilous and thermophilous plant species of angiosperm trees, even around the lgm (sadori et al., 2008). lateglacial mammal assemblages of sicily referred to castello fc indicate a rather arid climate, as it can be implied from the occurrence of e. hydruntinus and the relative abundance of m. savii group (masini et al., 2008; petruso et al., 2008, 2011a). however, there are no cold climate indicators on the island (martini et al., 2007; masini et al., 2008). probably, the steppe environment was due to the extremely low rainfall not associated with 194 spena m.t. et al. tab. 4 grotta dei pipistrelli (sicily, italy): percentages of all the taxa recovered in the cave according the minimum number of individuals (mni). data of chiroptera by salari et al. (2019). very low temperatures unlike, in particular, the adriatic side and inner apennine of southern italy (huntley et al., 1999; petronio et al., 2007; popov et al., 2014, among others). furthermore, the mammal assemblages show remarkable affinity with the coeval faunas of the south italy, in particular with those of the tyrrhenian side with the constant presence of red deer and wild boar (masini et al., 2008; petruso et al., 2011a) indicating the local spread of arboreal cover. these still scarce and fragmented data, however, suggest that, in a framework of global cooling, as attested by marine plankton, the environments of the island were diversified. probably, the paleoenvironment and the paleoclimate in the latest pleistocene were also connected to the physiography of the territory, to altitude above sea level and to the rainfall regime. in the middle holocene, a tendency to a progressive extension of open landscapes in the surrounding of grotta dei pipistrelli is suggested by the bat fossil remains (salari et al., 2019), and seems to have now been confirmed by the non-volant micromammal remains. this is also in agreement with the palaeoenvironmental indications provided by the 195 pleistocene-holocene micromammals from pipistrelli cave (sicily) tab. 5 synthesis of some ecological attributes of the bats (lanza, agnelli, 2002; agnelli et al., 2008; salari et al., 2019); s.s.: sensu stricto; s.l.: sensu lato. fig. 3 grotta dei pipistrelli (sicily, italy): percent ratio of the number of individuals according to the prevailing environment. wood and forest: rhinolophus euryale, rhinolophus mehelyi, myotis myotis, myotis capaccinii, plecotus cf. p. auritus and apodemus sylvaticus; mixed and various: crocidura sicula, rhinolophus ferrumequinum, myotis cf. m. mystacinus and miniopterus schreibersii; open: myotis blythii and microtus savii group. pollen and microcharcoal succession from pergusa lake (sadori & giardini, 2007; sadori et al., 2008, 2013), and by the small mammal assemblages from northwesttern sicily, such as grotta dell’uzzo (tagliacozzo, 1993), near san vito lo capo, and vallone inferno (lópez-garcía et al., 2013), in the madonie mountains. indeed, according to sadori et al. (2008, 2013), the wettest conditions of early holocene occurred in the mainland sicily at about 9,000 years bp, lasted until about 7,200 years bp, are followed by a trend towards very dry conditions at about 3,000 years bp. it is interesting to note that the beginning of the trend towards dry conditions recorded in pergusa lake is more or less in the same time as the grotta dei pipistrelli holocene samples. in contrast, the pollen successions from gorgo basso, preola lake and biviere di gela, coastal lakes in south sicily, indicate that evergreen broadleaved and deciduous forests expanded in these times at the cost of open communities (noti et al., 2009; tinner et al., 2009; calò et al., 2012). nevertheless, the hydrological regime of preola lake recorded a dry phase between 8,300 and 7,000 years bp (magny et al., 2011). in these cases, the distance from the sea and the altitude above sea level seem to be the mainly causes of the variability and spatial differences in the environmental responses to climate changes. 7. conclusions a species of eulipotyphla, crocidura sicula, and two taxa of rodentia, microtus savii group and apodemus sylvaticus, were recognized in the fossil assemblages from grotta dei pipistrelli (south-east sicily, italy). these taxa occur in the mammal assemblages of sicily since san teodoro fc and they are still part of the extant fauna. nowadays, they also occur in the hyblaean mountains and in the pantalica nature reserve. according to three 14 c radiometric dating, the small mammal remains were deposited in the latest pleistocene, during the lgm, and in the middle holocene. taphonomic remarks suggest that the two assemblages of non-volant micromammals probably come from pellets accumulated by asio otus. both the assemblages are oligotypical and similar to each other. nevertheless, the percentage variations in the recognized taxa suggest that the palaeoenvironment was slightly more wooded during the lgm than in the middle holocene. with the addition of the data on chiroptera from the same samples, the ecological features of all the identified taxa allow the outline of a composite landscape predominantly wooded with temperate-warm and humid climatic conditions in the surrounding of the cave, in both the lgm and middle holocene, but slightly less wooded during the middle holocene than in the lgm. the sicilian faunistic changes in the latest pleistocene were probably less influenced by the climate than the palaeogeographic evolution of the island. palaeoenvironmental and palaeoclimatic conditions in the lgm seem to be more connected with the physiography of the territory, the altitude on sea level and the low rainfall rather than the low temperatures. pergusa lake, in central sicily, is an endorheic basin, without tributaries, and the scarce rainfall have certainly favored the lowering of the lake level and the development of a prevalently open environment, such as steppe or semi-steppe. in contrast, low rainfall have probably not dried up the waterways of the pantalica nature reserve territory, in the hyblaean plateau, and the water supply provided by anapo river and its tributaries was great enough to support a rich and diversified vegetation cover, which hosted the micromammal communities and their predators. acknowledges we want to thank nunzio caruso, dipartimento regionale azienda foreste demaniali, and filadelfo brogna, director of the natural reserve “pantalica, valle dell’anapo e torrente cava grande”, for the permission to study the paleontological aspects of the fossil assemblages from grotta dei pipistrelli. we are also grateful to gianna innocenti, giuseppe di natale, tassos kotsakis, michele nanzarelli and giovanni occhipinti for their support. thanks also to giovanni amori and an anonymous reviewer for their useful suggestions and to lars van den hoek ostende for the critical reading of a previous version of the manuscript. references aa.vv. (2008) atlante della biodiversità della sicilia: vertebrati terrestri. studi e ricerche, 6. palermo: arpa sicilia, pp. 536. aa.vv. (2009) piano di gestione “monti iblei”. redazione del piano di gestione dei siti natura 2000 denominato monti iblei. codice por 1999.it.16.1. po.011/1.11/11.2.9/0336, pp. 479. agnelli p., di salvo i., russo d., sarà m. (2008) chirotterofauna della sicilia. in: aa.vv., atlante della biodiversità della sicilia: vertebrati terrestri. (ed. aa.vv.) studi e ricerche, 6. palermo: arpa sicilia, 25-40. aloise g., nappi a., contoli l. (2008) famiglia soricidae g. fisher, 1814. in: fauna d'italia. mammalia ii. (ed. amori g., contoli l., nappi a.). calderini per il sole 24 ore, milano, 130-136. amori g., capizzi d. (2008) famiglia cricetidae fisher, 1817. in: fauna d'italia. mammalia ii. (ed. amori g., contoli l., nappi a.). calderini per il sole 24 ore, milano, 441-444. amori g., castiglia r. (2018) mammal endemism in italy: a review. biogeographia, 33, 19-31. amori g., contoli l., nappi a. (2008) fauna d'italia. mammalia ii. calderini per il sole 24 ore, milano, pp. 736. andrews p. (1990) owls, cave and fossils. predation, preservation and accumulation of small mammal bones in caves, with an analysis of the pleistocene cave faunas from westbury-sub-mendip, somerset, uk. university of chicago press, chicago, pp. 231. antonioli f., vai g.b. (2004) litho-palaeo-environmental maps of italy during the last two climatic extremes. explanatory notes. museo geologico cappellini, bologna, pp. 75. 196 spena m.t. et al. aprile l., parrino c., abbate s., abbondo f., agosta c, armenia m., armenia r., arnone v., barrera g., cintoli e., colombo m., coria l., gugliotta i., lupo a., roccasalva g., rosa m., scala e., puzzo c. (2010) primi dati sui micromammiferi degli iblei mediante analisi delle borre di tyto alba (scopoli,1769) da un sito della sicilia sud-orientale in contrada spinagallo (siracusa). a c a d e m i a . e d u / 5 5 6 0 0 4 6 /m i c r o m a m mi f e ri_degli_iblei bertolani marchetti d., accorsi c.a., arobba d., bandini mazzanti m., bertolani m., biondi e., braggio g., ciuffi c., de cunzo t., della ragione s., furlani l., guido a.m., lolli f., montanari c., paoli p., raimondo f.m., rossitto m., trevisan grandi g. (1984) recherches géobotaniques sur les monts madonie (sicile du nord). webbia, 38, 329-348. bezerra a.m.r., annesi f., aloise g., amori g., giustini l., castiglia r. (2016) integrative taxonomy of the italian pine voles, microtus savii group (cricetidae, arvicolinae). zoologica scripta, 45, 225-236. bonfiglio l., di maggio c., marra a.c., masini f., petruso d. (2003) bio-chronology of pleistocene vertebrate faunas of sicily and correlation of vertebrate bearing deposits with marine deposits. il quaternario italian journal of quaternary sciences, 16, 107-114. burgio e., costanza m., di patti c., mannino a. (2005) attuali conoscenze sulle faune a vertebrati dei siti preistorici della sicilia occidentale. in: atti del 3° convegno nazionale di archeozoologia. (ed. fiore i., malerba g., chilardi s.). ipzs, roma, 145-171. cagnin m., grasso r. (1999) the communities of terrestrial small mammals (insectivora, rodentia) of the nebrodi mountains (north‐eastern sicily). italian journal of zoology, 66, 369-372. calò c., henne p.d., curry b., magny m., vescovi e., la mantia t., pasta s., vannière b., tinner w. (2012) spatio-temporal patterns of holocene environmental change in southern sicily. palaeogeography palaeoclimatology palaeoecology, 323 -325, 110-122. capizzi d. (2008) famiglia muridae (illiger, 1815). in: fauna d'italia. mammalia ii. (ed. amori g., contoli l., nappi a.). calderini per il sole 24 ore, milano, 575-577. capizzi d. (2013) microtus savii. iucn comitato italiano, accessed november 26, 2020. iucn.it/scheda.php?id=-1786522684 capizzi d., filippucci m.g. (2008a) genere apodemus kaup, 1829. in: fauna d'italia. mammalia ii. (ed. amori g., contoli l., nappi a.). calderini per il sole 24 ore, milano, 578-582. capizzi d., filippucci m.g. (2008b) apodemus sylvaticus (linnaeus, 1758). in: fauna d'italia. mammalia ii. (ed. amori g., contoli l., nappi a.). calderini per il sole 24 ore, milano, 604-618. capizzi d., luiselli l. (1998) a comparative study of the variability of owl diets in three localities of central italy. revue d’ecologie (la terre et la vie), 53, 367-385. casini l., magnani a. (1988) alimentazione invernale di gufo comune asio otus in un'area agricola dell'emilia orientale. avocetta, 12, 101-106. castioni c., debernardi p., patriarca e. (1998) l’alimentazione invernale del gufo comune (asio otus) nel parco del ticino (italia nord-occidentale). rivista piemontese di storia naturale, 19, 299-312. catalano g., modi a., mangano g., sineo l., lari m., bonfiglio l. (2020) a mitogenome sequence of an equus hydruntinus specimen from late quaternary site of san teodoro cave (sicily, italy). quaternary science reviews, 236, 106280. catalisano a., sarà m. (1995) l’arvicola terrestris in sicilia. atti della società italiana di scienze naturali e del museo civico di storia naturale di milano, 134, 8-12. cecere j.g., bombino s., santangeli a. (2013) winter diet of long-eared owl asio otus in a mediterranean fragmented farmland. wilson journal of ornithology, 125, 655-658 chaline j., brunet-lecomte p., graf j.d. (1988) validation de terricola (fatio, 1867) pour les campagnol souterrains (arvicolidae, rodentia) paléarctiques actuels et fossiles. comptes rendus de l’académie des sciences de paris, 306, 475-478. contoli l. (2008) genere crocidura wagler, 1832. in: fauna d'italia. mammalia ii. (ed. amori g., contoli l., nappi a.). calderini per il sole 24 ore, milano, 183-197. contoli l., nappi a., castiglia r. (2008) caratteri generali dei microtus (terricola) del “gruppo savii”. in: fauna d'italia. mammalia ii. (ed. amori g., contoli l., nappi a.). calderini per il sole 24 ore, milano, 525-535. cramp s. (ed., 1985) the bird of the western palearctic, iv. terns to woodpecker. oxford university press, pp. 960. curcio m.t., contoli l. di canzio e., kotsakis t. (2005) preliminary analysis of m1 of late pleistocene and recent populations of terricola savii from italy (arvicolidae; rodentia). geo. alp, 2, 91-98. fernández-jalvo y., andrews p., denys c., sesé c., stoetzel e., martín-monfort d., pesquero d. (2016) taphonomy for taxonomists: implications of predation in small mammal studies. quaternary science reviews, 139, 138-157. ferrante m., spena m.t., hernout b.v., grasso a., messina a., grasso r., agnelli p., brundo m.v., copat c. (2018) trace elements bioaccumulation in liver and fur of myotis myotis from two caves of the eastern side of sicily (italy): a comparison between a control and a polluted area. environmental pollution, 240, 273-285. forgia v., martín p. lópez-garcía j.m., ollé a., vergès j.m., allué e., angelucci d.e., arnone m., blain h.a., burjachs f., expósito i., messina a., picornell l., rodríguez a., scopelliti g., sieno l., virruso g., alessi e., di simone g., morales j.i., pagano e., belvedere o. (2013) new data on sicilian prehistoric and historic evolution in a mountain context, vallone inferno (scillato, italy). comptes rendus palevol, 12, 115-126. 197 pleistocene-holocene micromammals from pipistrelli cave (sicily) galeotti p. (2003) strigiformes. in: uccelli d’italia. (ed. spagnesi m., serra l.). quaderni di conservazione della natura 16, min. ambiente, ist.naz. fauna selvatica, 201-221. huntley b., watts w.a., allen j.r.m., zolitschka b. (1999) palaeoclimate, chronology and vegetation histoty of the weichselian lateglacial: comparative analysis of data from three cores at lagi grande di monticchio, southern italy. quaternary science review, 18, 945-960. hayes a., kucera m., kallel n., sbaffi l., rohling e.j. (2005) glacial mediterranean sea surface temperatures based on planktonic foraminiferal assemblages. quaternary science reviews, 24, 999 -1016. ientile r., massa b. (2008) uccelli (aves). in: atlante della biodiversità della sicilia: vertebrati terrestri. (ed. aa.vv.) studi e ricerche, 6. palermo: arpa sicilia, 113-211. incarbona a., agate m., arisco g., bonomo s., buccheri g., di patti c., di stefano e., greco a., madonia g., masini f., petruso d., sineo l., sprovieri r., surdi g., zarcone g. (2010) ambiente e clima in sicilia durante gli ultimi 20 mila anni. il quaternario italian journal of quaternary sciences, 23, 21-36. kotsakis t. (1986) crocidura esui n. sp. (soricidae, insectivora) du pléistocène supérieur de spinagallo (sicilia orientale, italie). geologica romana, 23, 51-64. kotsakis t. (2008) storia paleontologica di erinaceimorfi, soricomorfi, lagomorfi e roditori attuali d’italia. in: fauna d'italia. mammalia ii. (ed. amori g., contoli l., nappi a.). calderini per il sole 24 ore, milano, 1-32. kotsakis t., pandolfi l., maiorino l., petronio c., sansalone g., salari l. (2020) small vertebrates from the late pleistocene avetrana (apulia, southern italy) karst filling. estudios geologicos, 76(1), e122 (1-23). lanza b., agnelli p. (2002) chirotteri, chiroptera blumenbach, 1779. in: mammiferi d’italia. (ed. spagnesi m., de marinis a.m.). quaderni di conservazione della natura 14, min. ambiente, ist.naz. fauna selvatica, 44-142. locatelli e., masini f., petruso d., sala b., surdi g. (2011) osservazioni preliminari sulla tassonomia e la biogeografia di microtus (terricola) (mammalia, rodentia) fossile in sicilia. biogeographia, 30, 41-60. lópez-garcía j.m., blain h. a., pagano e., ollé a., vergès j.m., forgia, v. (2013) the small mammals (insectivores, bats and rodents) from the holocene archeological site of vallone inferno (scillato, lower imera valley, northwestern sicily). rivista italiana di paleontologia e stratigrafia, 119, 229-244. loy a., aloise g., ancillotto l., angelici f. m., bertolino s., capizzi d., castiglia r., colangelo p., contoli l., cozzi b., fontaneto d., lapini l., maio n., monaco a., mori e., nappi a., podestà m. a., sarà m., scandura m., russo d., amori g. (2019) mammals of italy: an annotated checklist. hys 198 spena m.t. et al. trix, the italian journal of mammalogy, 30, 87-106. magny m., vannière b., calo c., millet l., leroux a., peyron o., zanchetta g., la mantia t., tinner w. (2011) holocene hydrological changes in southwestern mediterranean as recorded by lake-level fluctuations at lago preola, a coastal lake in southern sicily, italy. quaternary science reviews, 30, 2459-2475. marra a.c. (2013) evolution of endemic species, ecological interactions and geographical changes in an insular environment: a case study of quaternary mammals of sicily (italy, eu). geosciences, 3, 114-139. marsh a.c.w., harris s. (2000) partitioning of woodland habitat resources by two sympatric species of apodemus: lessons for the conservationsof the yellow-necked mouse (a. flavicollis) in britain. biological conservation, 92, 275-283. martini f., lo vetro d., colonese a.c., de curtis o., di giuseppe z., locatelli e., sala b. (2007) l’epigravetiano finale in sicilia. in: l’italia tra 15000 e 10000 anni fa. cosmopolitismo e regionalità nel tardoglaciale. (ed. martini f.). museo fiorentino di preistoria “paolo graziosi”, firenze, 209-254. masini f., petruso d., bonfiglio l., mangano g. (2008) origination and extinction patterns of mammals in three central western mediterranean islands in the late miocene to quaternary. quaternary international,182, 63-79. masseti m. (2002) uomini e (non solo) topi. gli animali domestici e la fauna antropocora. firenze university press, pp. 337. minissale p., sciardrello s., spampinato g. (2007) analisi della biodiversità vegetale e relativa cartografia della riserva naturale orientata “pantalica, valle dell’anapo e torrente cava grande” (sicilia sudorientale). quaderni di botanica ambientale e applicata, 18, 145-207. montgomery w.i. (1999) apodemus sylvaticus. in: the atlas of european mammals. (ed. mitchell-jones a.j., amori g., bogdanowicz w., kryštufek b., reijnders p.j.h., spitzenberger f., stubbe m., thissen j.b.m., vohralík v. zima j.). t. & a.d. poyser natural history, london, 274-275. nappi a. (2001) micromammiferi d’italia. napoli, pp. 112. nappi a., contoli l. (2008) indicazioni per un riconoscimento preliminare dei taxa del genere microtus presenti in italia. in: fauna d'italia. mammalia ii. (ed. amori g., contoli l., nappi a.). calderini per il sole 24 ore, milano, 475-484. niethammer j. (1978) apodemus flavicollis gelbhalsmaus, apodemus sylvaticus waldmaus. in: handbuch der säugetiere europas, band 1/i: rodentia i (sciuridae, castoridae, gliridae, muridae). (ed. niethammer j., krapp f.). akademische verlagsgesellschaft, wiesbaden, 325-358. niethammer j., krapp f. (eds., 1978) handbuch der säugetiere europas, band 1/i: rodentia i (sciuridae, castoridae, gliridae, muridae). akademische verlagsgesellschaft, wiesbaden, pp. 476. noti r., van leeuwen j.f.n., colombaroli d., vescovi e., pasta s., la mantia t., tinner w. (2009) mid 199 pleistocene-holocene micromammals from pipistrelli cave (sicily) and late-holocene vegetation and fire history at biviere di gela, a coastal lake in southern sicily, italy. vegetation history and archaeobotany, 18, 371-387. petronio c., di canzio e., salari l. (2007) the late pleistocene and holocene mammals in italy: new biochronological and paleoenvironmental data. palaeontographica, abt. a 279, 147-157. petruso d., cusumano m., domina d., pavia m., masini f. (2008) una valutazione tassonomica quantitativa preliminare della documentazione di vertebrati del quaternario della sicilia. atti del museo civico di storia naturale di trieste, 53 (suppl.), 189-232. petruso d., locatelli e., surdi g., dalla valle c., masini f., sala b. (2011b) phylogeny and biogeography of fossil and extant microtus (terricola) (mammalia; rodentia) of sicily and the southern italian peninsula based on current dental morphological data. quaternary international, 243, 192203. petruso d., sarà m., surdi g., masini f. (2011a) le faune a mammiferi della sicilia tra il tardoglaciale e l’olocene. biogeographia, 30, 27-39. piras p., marcolini f., raia p., curcio m.t., kotsakis t. (2010) ecophenotypic variation and phylogenetic inheritance in first lower molar shape of extant italian populations of microtus (terricola) savii (rodentia). biological journal of the linnean society, 99, 632-647. popov v.v., di canzio e., giaccio b. (2014) late quaternary small mammals and paleotemperatures in bulgaria and italy, acta zoologica bulgarica, 66, 89-108. repenning c.a. (1967) subfamilias and genera of the soricidae. united states government printing office, washington, pp. 78. riga f., capizzi d. (1999) dietary habits of the longeared owl asio otus in the italian peninsula. acta ornithologica, 34, 45-51. ronninger m. (2009) troian mice: a contribution to postcranial morphology of the rodent genera mus, apodemus, microtus, cricetulus and meriones. bioarchaeologica, 5, 227-235. sadori l., giardini m. (2007) charcoal analysis, a method to study vegetation and climate of the holocene: the case of lago di pergusa, sicily (italy). geobios, 40, 173-180. sadori l., ortu e., peyron o., zanchetta g., vannière b., desmet m., magny m. (2013) the last 7 millennia of vegetation and climate changes at lago di pergusa (central sicily, italy). climate of the past, 9, 1969-1984. sadori l., zanchetta g., giardini m. (2008) last glacial to holocene palaeoenvironmental evolution at lago di pergusa (sicily, southern italy) as inferred by pollen, microcharcoal, and stable isotopes, quaternary international, 181, 4-14. salari l. (2014) holocene micromammals (soricomorpha and rodentia) from some caves of central italy. revue de paléobiologie, 33, 79-96. salari l., agnelli p., calcagnile l., di maita j., grasso r., quarta g., santoro c., spena, m.t. (2019) the fossil bat assemblages from grotta dei pipistrelli in pantalica (southeastern sicily, italy): chronological and palaeoecological implications. comptes rendus palevol, 18, 417-441. sarà m. (1990) aspetti della nicchia ecologica degli strigiformi in sicilia. naturalista siciliano, 14 (suppl.), 109-122. sarà m. (2008a) crocidura sicula miller, 1900. in: fauna d'italia. mammalia ii. (ed. amori g., contoli l., nappi a.). calderini per il sole 24 ore, milano, 210 -218. sarà m. (2008b) arvicola di savi microtus savii (de sélys longchamps, 1838). in: atlante della biodiversità della sicilia: vertebrati terrestri. (ed. aa.vv.). studi e ricerche, 6. arpa sicilia, palermo, 61-63. sarà m. (2008c) topo selvatico apodemus sylvaticus (l., 1758). in: atlante della biodiversità della sicilia: vertebrati terrestri. (ed. aa.vv.). studi e ricerche, 6. arpa sicilia, palermo, 69-71. sbaffi l., wezel f.c., kallel n., paterne m., cacho i., ziveri p., shackleton n. (2001) response of the pelagic environment to palaeoclimatic chan ges in the central mediterranean sea during the late quaternary. marine geology, 178, 39-62. sergio f., marchesi l., pedrini p. (2008) density, diet and productivity of long-eared owls asio otus in the italian alps: the importance of microtus voles. bird study, 55, 321-328. siracusa m. (1997) primi dati sull’alimentazione dell’allocco (strix aluco) sui monti iblei (sicilia, italia). naturalista siciliano, 21, 129-131. siracusa m., sarà m., la mantia t., cairone a. (1996) alimentazione del gufo comune (asio otus) in sicilia. naturalista siciliano, 20, 313-320. spena m.t., allegra filosico m., brogna f., dipasquale c., puma a., grasso r., agnelli p. (2013) i chirotteri della grotta dei pipistrelli (sr): un unicum nella sicilia sud-orientale. atti della società dei naturalisti e matematici di modena, 144, 171. spena m.t., agnelli p., di maita j., grasso r., reitano a., santoro c., salari l. (2017) pleistocene bats (mammalia, chiroptera) from grotta dei pipistrelli (southeastern sicily, italy). preliminary report. barbastella journal of bat research, 10, 37-41. surdi g. (2008) i micromammiferi tardo quaternari della sicilia e del sud della penisola italiana. phd thesis in geological sciences, palermo university, pp. 333. tagliacozzo a. (1993) archeozoologia della grotta dell’uzzo, sicilia. da un’economia di caccia ad un’economia di pesca e di allevamento. bullettino di paletnologia italiana, 84 (suppl.), 1-278. tellería j.l., santos t., alcántara m. (1991) abundance and food-searching intensity of wood mice (apodemus sylvaticus) in fragmented forests. journal of mammalogy, 72, 183-187. tinner w., van leeuwen j.f.n., colombaroli d., vescovi e., van der knaap w.o., henne p.d., pasta s., d’angelo s., la mantia t. (2009) holocene environmental and climatic changes at gorgo basso, a coastal lake in southern sicily, italy. quaternary science reviews, 28, 1498-1510. tyberg t. (2008) pleistocene bird of palearctic. web.telia.com/~u11502098/pleistocene.html unesco (1992-2019) syracuse and the rocky necropolis of pantalica. whc.unesco.org/en/list/1200 villari p. (1995) le faune della tarda preistoria nella sicilia orientale. ente fauna siciliana, siracusa, pp. 493. zanca l., sarà m. (2008) toporagno di sicilia crocidura sicula miller, 1900. in: atlante della biodiversità della sicilia: vertebrati terrestri. (ed. aa.vv.). studi e ricerche, 6. arpa sicilia, palermo, 46-48. zanchetta g., borghini a., fallick a.e., bonadonna f.p., leone g. (2007) late quaternary palaeohydrology of lake pergusa (sicily, southern italy) as inferred by stable isotopes of lacustrine carbonates. journal of paleolimnology, 38, 227-239. 200 spena m.t. et al. ms. received: september 15, 2020 revised: november 14, 2020 accepted: december 17, 2020 available online: february 24, 2021 imp.07carobene le variazioni ambientali nell’area di vado ligure dal neolitico ad oggi luigi carobene, marco firpo & alessio rovere dipartimento per lo studio del territorio e delle sue risorse (dipteris), università di genova, carobene@dipteris.unige.it corso europa, 26 – 16132 genova, italy riassunto: carobene l., firpo m. & rovere a., le variazioni ambientali nell’area di vado ligure dal neolitico ad oggi (it issn 03943356, 2008). sono stati studiati i profili sismici e 13 sondaggi effettuati nella rada di vado ligure, in corrispondenza della foce del t. segno. la località si trova 4-5 km a so di savona, lungo la costa della liguria occidentale. la trasgressione olocenica documentata dai sondaggi è stata messa in relazione con le variazioni del paesaggio degli ultimi 8-9000 anni; il periodo coincide con l’inizio e lo sviluppo del neolitico. sono state prese in considerazione le caratteristiche morfologiche e geologiche dell’area sia emersa che marina, al fine di confrontare la sua evoluzione recente con lo sviluppo dell’eustatismo e della tettonica quaternaria. questi due eventi sono documentati da 5 ordini di terrazzi marini che hanno permesso di valutare la velocità di sollevamento dell’area durante il quaternario. i sondaggi, di cui 10 effettuati a mare, hanno consentito di riconoscere il substrato, costituito da argille marnose del pliocene inferiore, i depositi continentali riferibili al periodo di basso eustatico (würm) ed il corpo sedimentario marino della trasgressione olocenica. le 25 datazioni c14 effettuate hanno fornito età calibrate comprese tra 8225 e 510 anni b.p.; le date sono state utilizzate per effettuare la cronostratigrafia del deposito marino olocenico. la correlazione dei risultati ricavati dall’analisi del profilo sismico, dallo studio sedimentologico delle carote e dalle datazioni c14 ha consentito di riconoscere: una fase trasgressiva, terminata 6000 anni fa, seguita da un periodo di relativa stabilità della linea di riva; un successivo periodo di progradazione e, infine, il periodo dell’alto eustatico interglaciale che arriva ai nostri giorni. le varie tappe della risalita eustatica sono state ricostruite lungo un profilo geologico che ha portato a determinare le linee di riva di 8000 anni fa (-12 m), di 7000 anni fa (-6,5 m), di 6000 anni fa (-3 m) e di 5000 anni fa (-1,5 m). sulla base di questi dati è stata costruita una curva di risalita del livello marino e sono state riconosciute le grandi modificazioni del paesaggio causate dalla trasgressione olocenica. circa 9000 anni fa, un’ampia superficie emersa si estendeva per almeno un chilometro verso mare. nell’arco di 3000 anni la piana viene però ricoperta dall’avanzata del mare, mentre il fondovalle del t. segno diventa inospitale. dopo un periodo di relativa stabilità, durato fino al 5000 b.p., il forte accumulo di detriti lungo costa provoca la progradazione della spiaggia emersa e sottomarina e la contemporanea aggradazione della piana alluvionale del t. segno. a partire da 1800 anni fino ad oggi, la linea di costa ritorna relativamente stabile; la pianura alluvionale del t. segno diventa di nuovo abitabile o utilizzabile per le coltivazioni, anche se non in maniera continuativa. la diminuzione dello spazio e l’aumento probabile della popolazione porta però all’uso della deforestazione; ciò innesca il dilavamento dei versanti e l’erosione dei suoli, come sembra documentare lo spesso corpo limoso che si viene rapidamente a formare nell’antistante area marina. abstract: carobene l., firpo m. & rovere a., the environmental variations in the vado ligure area from the neolithic age until present (it issn 0394-3356, 2008). seismic profiles and 13 drilling cores were studied in the vado ligure gulf, in front of the segno river delta. the study area is located 4-5 km sw from savona, along the western ligurian coast. the holocene transgression highlighted by the surveys was related to the variations of the landscape in the last 8-9000 years; this period corresponds to the beginning and the development of the neolithic. subaerial (fig. 1) and marine (fig. 2) morphological features were taken into account in order to compare the recent evolution of the study area with the most important quaternary events, such as eustatism and tectonic activity. these two events are documented by 5 orders of marine terraces comprised between 185 and 35 m a.s.l.; this allowed us to conclude that the tectonic rising rates of the study area during quaternary have been low, and successively decreased. this evidence supported the assertion that the study area has been substantially stable during holocene. moreover, systems of quaternary faults have conditioned the direction of crests and the drainage patterns. the cores, 10 of which were made in the marine part of the study area, allowed us to recognize the substratum, that is constituted by lower pliocene marly clays, by the continental deposits referable to the low eustatic stand (würm) and by the marine sedimentary body of the holocene transgression (fig. 8). the marine deposits of the tyrrhenian transgression (stage 5.5) are absent. 25 c14 datings provided calibrated ages comprised between 8225 and 510 yrs bp; the data were used to obtain the chronostratigraphy of the marine deposit (fig. 12). the correlation of the results obtained by the seismic profile analysis (fig. 4), by the sedimentological study of the drilling cores (fig. 5) and by the c14 datings allowed us to recognize a transgressive phase, which ended 6000 yrs bp; a period of relative eustatic standing (from 6000 to 5000 yrs bp); a subsequent period of progradation (from 5000 to 1800 yrs bp) and, finally, the period of the interglacial high eustatic stand that continues to the present (fig. 14). the whole sedimentary marine body reaches a thickness of about 14 meters. the various stages of the eustatic sea level rise were reconstructed along a geologic profile that continues landward. the seismic profile was documented by the alignment of 9 cores; this allowed us to recognize the shorelines dated 8000 bp (-12 m), 7000 bp (-6,5 m), 6000 bp (-3 m), and 5000 bp (-1,5 m) (fig. 14). on the basis of these data an eustatic curve was obtained (fig.15) and the large modifications of the landscape caused by the holocene transgression were recognised. about 9000 yrs bp a large surface with a low inclination spread landward for at least 1 km; taking into account the improvement of the climate, this plain could be used for agriculture. however, in the space of 3000 years, the plain was flooded by the rising sea level, while the valley floor of the segno river became inhospitable, because it began to be flooded by continuous inundations. after a period of relative stability, that had lasted since 5000 yrs bp, the continued accumulation of debris along the coast caused the progradation of both the emerged and submerged beaches and the contemporaneous aggradation of the alluvial plain of the segno river. this drove the ancient inhabitants to live and build mainly on the hillsides, mainly in the terraced surfaces. starting from 8000 yrs bp till present, the coastline became again relatively stable; in the sea bottom the deposition of the sedimentary sequence relative to the last eustatic interglacial peak began. the alluvial plain of the segno river became stable again or useful for agriculture, even if not in a permanent way. the reduction of space and the probable increase in the population lead to the use of deforestation; this started with the washing of the hillsides and the erosion of soils, as documented by the thick silty-clayey body that rapidly formed in the marine area. parole chiave: trasgressione olocenica, curva eustatica, neolitico, rilievo sismico, carotaggi, stratigrafia, datazioni c14, vado ligure, italia keywords: holocene transgression, eustatic curve, neolithic, seismic survey, drilling cores, stratigraphy, c14 radiometric datations, vado ligure, italy il quaternario italian journal of quaternary sciences 21(2), 2008 433-456 434 l. carobene, m. firpo & a. rovere premessa il rapporto tra la variazione degli ambienti, causata da fattori climatici, e l’uomo che li abita, è un tema di attualità, ma il problema è sempre esistito. con riferimento all’olocene, è dimostrabile che determinati cambiamenti siano stati ben più veloci e più importanti di quelli che oggi tanto preoccupano (quali l’effetto serra, la desertificazione, le alluvioni, le attività dell’uomo, ecc.). al notevole aumento della temperatura, ad esempio, verificatosi da 11.000 a 8.000 anni fa (vedasi curve isotopiche dell’ossigeno), è corrisposto un innalzamento del livello marino di circa 35-45 metri; tra 8000 e 5000 anni fa la temperatura è rimasta sostanzialmente uguale (ottimo termico), mentre appare in leggera diminuzione da allora ad oggi. a livello locale (dove l’influenza della tettonica appare trascurabile), il livello marino è risalito, negli ultimi 8000 anni, di circa 12 metri. contemporaneamente variavano le precipitazioni atmosferiche, le portate dei corsi d’acqua, la copertura vegetale sui versanti, ecc. il tentativo di mettere in relazione gli antichi ambienti con le popolazioni umane che, dalla fine del mesolitico inizio neolitico, hanno frequentato la costa ligure, obbliga pertanto a riconoscere gli eventi principali (climatici, eustatici, tettonici) che si sono succeduti nel tempo e gli effetti che essi hanno provocato nel paesaggio fisico. il problema è stato affrontato utilizzando svariate metodologie: ci si è avvalsi di carotaggi effettuati nella rada di vado ligure (savona), dell’analisi di carte topografiche e batimetriche, dell’interpretazione di foto aeree, di analisi granulometriche di laboratorio, di datazioni c14 e della distribuzione dei siti archeologici dell’area. lo studio sedimentologico delle carote ha fornito indispensabili elementi per la comprensione della risalita eustatica olocenica e dei processi erosivi e sedimentari ad essa connessi, sia marini che subaerei. l’interpretazione cronostratigrafica è metodologicamente interessante; essa ha permesso di determinare superfici isocrone e la posizione di quattro antiche linee di riva mediante un originale procedimento grafico. gli eventi e i processi evidenziati hanno comportato grandi cambiamenti morfologici del paesaggio, la sedimentazione di decine di metri di sedimenti marini e continentali, lo spostamento della linea di riva di circa 1 km verso terra nel giro di 3000 anni. le carote di vado hanno costituito, pertanto, una fonte di informazioni forse unica, non solo per ciò che è successo a mare, ma anche a terra, nella piana, sui versanti e nel bacino idrografico del t. segno. uno studio ulteriore, rivolto all’analisi palinologica e a quella geochimica, potrà fornire preziosi dati per comprendere anche gli aspetti climatici ai quali è legato lo sviluppo della vegetazione e la formazione dei suoli. 1. cenni di geologia nel bacino idrografico del t. segno affiorano in gran parte terreni riferibili agli “scisti di gorra”; essi appartengono al così detto “tegumento permocarbonifero” (con metamorfismo solamente alpino) che si interpone tra il basamento cristallino paleozoico e le rocce sedimentarie della copertura mesozoica. gli scisti di gorra comprendono numerosi litotipi, tra i quali prevalgono quarzoscisti, scisti quarzo-sericitici e cloritici e micascisti. al loro interno sono presenti lenti della formazione di eze (metabasiti) e di porfiroidi del melogno (metavulcaniti acide). gli scisti sono compresi stratigraficamente tra la formazione di murialdo (a letto) e i porfiroidi del melogno (a tetto); lo spessore è di alcune centinaia di metri. sul promontorio di vado ligure (capo vado) e, in parte, sul versante sinistro della valle, affiora la “formazione di murialdo”, attribuita al carbonifero superiore-medio. essa è costituita in prevalenza da filladi e micascisti carboniosi scuri; frequenti le lenti di quarzo cristallino. sul promontorio di vado ligure affiorano anche piccoli lembi di “graniti del torrente letimbro”, appartenenti al “basamento cristallino”, molto diffusi più a nord (massiccio cristallino savonese). i graniti sono biotitico-muscovitici o muscovitico-cloritici, foliati o con tessitura occhiadina, a grana grossolana; la roccia si presenta molto fratturata e milonitizzata. sul versante destro del t. segno affiorano localmente le “dolomie di s. pietro dei monti”, visibili anche sul promontorio di bergeggi. la formazione appartiene alla “copertura meso-cenozoica”; la sua età è anisicoladinica. le dolomie si presentano spesso stratificate, a volte con livelli o interstrati pelitici, con aspetto scistoso. il metamorfismo ha dolomitizzato e ricristallizzato l’originario sedimento carbonatico, mentre la tettonica ha prodotto una fitta e intensa fratturazione. in sinistra idrografica del t. segno, lungo la fascia costiera tra vado e savona, affiora infine il pliocene inferiore in facies argillosa (“argille di ortovero” auct.); a volte le argille sono sormontate da sabbie e conglomerati (boni, 1984; fanucci et alii, 1980). le formazioni affioranti nel bacino idrografico del t. segno, sopra brevemente descritte, comprendono in gran parte litotipi facilmente erodibili: scisti quarzosi e micacei, filladi e argille; nettamente subordinati i graniti e le dolomie. ciò permette di comprendere che la sedimentazione marina, alimentata dal trasporto solido del t. segno, è stata (ed è ancora) costituita in prevalenza da particelle siltose e da sabbie fini quarzose. la sedimentazione continentale, durante le fasi di basso eustatico (periodi glaciali), è stata dominata da clasti spigolosi generati dalla degradazione fisica (favorita dalla scistosità e dalla fitta fratturazione), e dalla abbondante presenza, derivante da prevalenti processi di alterazione pedogenetica, della componente argilloso-siltoso-sabbiosa. questa ha favorito il meccanismo del trasporto e della messa in posto del detrito mediante prevalenti colate detritiche. 2. aspetti morfologici del paesaggio l’interpretazione dei carotaggi effettuati nella rada di vado non può prescindere né dagli aspetti morfologici dell’area emersa, né da quelli dell’area marina antistante. ampiezza del bacino del torrente segno, altitudini, pendenze dei versanti e reticolo idrografico hanno sicuramente condizionato i processi subaerei e, quindi, l’erosione e la sedimentazione. analogamente, morfologia dei fondali e batimetria hanno influenzato i processi sia durante le fasi di basso eustatico, sia durante i periodi di trasgressione e di alto stazionamento. il pattern del drenaggio ha una forma parzialmente condizionata dalla tettonica; in particolare, l’asta principale ha un netto andamento rettilineo in direzione circa ene-oso (65°); lo spartiacque settentrionale (crinale rocca dei corvi, 793 m – cima pian mora, 383 m) ha identico andamento (fig. 1b). la direzione del t. segno è anomala lungo la riviera di ponente, dove prevalgono i drenaggi verso se circa; la direzione di 65° (drenaggio verso ene) del t. segno (escludendo il tratto finale relativo alla piana alluvionale) è infatti coincidente con quella del tratto di costa che va da albissola (savona) a voltri (genova) 435le variazioni ambientali ... (direzione media 60°). questo importante aspetto morfologico (carobene & firpo, 2002) è da riferire ad un sistema di faglie dirette (direz. 60-65°) che caratterizza il margine interno della piattaforma continentale (fanucci, 1978; cnr, 1987). la parte occidentale del bacino idrografico è chiusa da un tratto di spartiacque con andamento rettilineo avente direzione circa nno – sse (circa 150°) (crinale rocca dei corvi, 793 m – bric berba, 560 m) (fig. 1). numerose aste fluviali, sia all’interno che all’esterno del bacino del segno, presentano direzioni simili, e pertanto il loro andamento risulta controllato da un sistema di faglie subverticali a 145-150°. i due citati sistemi di dislocazioni (60-65° e 145150°) (ricavati mediante un’analisi morfotettonica che in questa sede non viene presentata), sono da riferire alla fig. 1 a) schema semplificato della topografia dell’area. profilo a-b (vedi fig. 13). pat= lembo della piana alluvionale riferibile al mis 5.5 (quota: 9÷10 m); rt=relitto di terrazzo marino antico. b) bacino idrografico del t. segno. principali rilievi lungo il crinale: 1-m. pian mora (383 m); 2-rocca dei corvi (793 m); 3-rocca dei corvi sud (785 m); 4-bric del forno (542 m); 5-bric berba (560 m); 6bric colombino (433 m). a) simplified scheme of the study area topography. transect a-b (see fig. 13 for details). pat=relic of the alluvial plain, which can be attributed to the mis 5.5 (altitude 9÷10 m); rt= marine terrace relic. legend: 1) bathymetry; 2) delta; 3) relief base; 4) hydrography; 5) alluvium, valley floor terraces, fans and fan deposits; 6)late holocene shoreline deposits; 7)pre-quaternary substratum; 8)artificially levelled areas; 9) harbour; 10) maximum holocenic marine ingression 11) archaeological sites. b) hydrographic basin of the segno river. main relieves along the crest: 1-m. pian mora (383 m); 2-rocca dei corvi (793 m); 3-rocca dei corvi sud (785 m); 4-bric del forno (542 m); 5-bric berba (560 m); 6bric colombino (433 m). tettonica fragile che ha accompagnato il sollevamento dell’area durante il plio-quaternario. l’area a mare antistante vado ligure presenta una morfologia complessa deducibile dall’analisi delle batimetriche; tre sono gli elementi morfologici principali (fig. 2): 1) un ampio canyon, con asse principale disposto a 130° circa, la cui testata diventa visibile a partire dalla profondità di 60-70 metri. la valle si amplia progressivamente verso il basso ed è ancora ben visibile oltre i 900 m di profondità (fanucci et alii, 1996). 2) un promontorio sommerso che delimita a so il canyon; esso si prolunga verso se, a partire dall’isola di bergeggi, con una inclinazione media del fondale (tra 0 e -250 m) di 2,6°, lungo un asse avente direzione 120°. 3) un altro promontorio sommerso delimita a no il canyon, con asse di allungamento disposto a 130° circa; l’inclinazione media del fondale lungo l’asse (tra 0 e -100 m) è di 1° circa. il fondale che si estende di fronte alla foce del t. segno, tra la linea di riva e la batimetrica di -70 m, degrada regolarmente verso est con una inclinazione di poco inferiore a 2°, per un’ampiezza di circa 2 km. la regolarità della superficie e l’assenza di incisioni vallive in corrispondenza dei torrenti segno e quiliano (che sfocia circa 1 km più a nord), permettono di dedurre che la trasgressione olocenica ha prodotto una copertura sedimentaria capace di livellare ogni asperità, colmando anche le incisioni vallive formatesi durante il basso eustatico würmiano. verso savona questa ampia superficie sedimentaria si allarga ulteriormente fino al ciglio della piattaforma. da quanto esposto, si ricava che i maggiori aspetti morfologici dell’area sottomarina a est di vado risultano condizionati da un sistema di faglie trasversali alla costa disposto ese – ono (120° – 130°); tale direzione è deducibile anche dall’analisi delle isocrone raffiguranti il basamento acustico pre-pliocenico, che fornisce valori di 125-130° per la direzione dell’asse del canyon sottomarino, oggi sepolto da un considerevole spessore di sedimenti plioquaternari. ciò permette di concludere che il sistema a 120° 130° corrisponde probabilmente a faglie antiche, preplioceniche; esse sono presenti tuttavia anche nel reticolo idrografico del t. segno (lungo il prolungamento del promontorio sommerso che parte dall’isola di bergeggi). il sistema di faglie con direzione prevalente a 65° (circa parallela alla linea di costa), ricavato dall’analisi dell’area emersa, è stato segnalato anche a mare (fanucci, 1979), dove origina nella piattaforma una struttura a gradinata verso il largo o strutture tipo horst e graben. i terrazzi fluviali e marini sono un altro aspetto morfologico che caratterizza l’area e che fornisce importanti informazioni sulla sua evoluzione quaternaria. cinque ordini di superfici terrazzate sono stati riconosciuti lungo il settore costiero quiliano-segno, a 165÷185 m, a 130÷145 m, a 115÷130 m, a 55÷70 m e a 35÷45 m s.l.m. (carobene, da dati inediti). i terrazzi sono da ritenersi, per le loro caratteristiche e per la posizione lungo costa, di genesi marina; la loro quota è maggiore a sud. lungo la valle del t. segno sono state invece riconosciuti 25 relitti di superfici terrazzate fluviali in destra idrografica tra le quote di 395 e 45 m e, in sinistra idrografica, 20 relitti tra 255 e 75 m s.l.m. forme terrazzate a quote più basse (sia fluviali che marine) non sono state prese in considerazione, a causa delle incertezze dovute alla loro marcata antropizzazione. la correlazione dei relitti sopra citati ha permesso di identificare 8 ordini di terrazzi fluviali, di cui 5 ben si correlano con gli ordini di terrazzi marini sopra citati. detti ordini sono attribuibili al quaternario; ciò si può dedurre indirettamente dalle velocità di sollevamento che il settore costiero ha subito durante il plio-quaternario, successivamente alla deposizione delle argille che (v. cap. 1) sono state attribuite al pliocene inferiore e che oggi affiorano lungo costa fino alla quota massima di 100 m. la metodologia utilizzata per ricavare il tasso di sollevamento è stata esposta in dettaglio in carobene & firpo (2002) e in carobene & cevasco (2007); in base alla probabile profondità di sedimentazione delle argille, alla loro quota massima attuale di affioramento e alla data presunta di inizio sollevamento, il tasso medio risulterebbe di 0,15 mm/a. in base a tale valore, un terrazzo marino del pleistocene inferiore 436 fig. 2 la carta batimetrica evidenzia un tratto di piattaforma privo di incisioni fino alla profondità di circa 70 m; un canyon molto evidente con asse (a.c.) disposto a 130° fino alla profondità di 1000 m; 2 promontori a so e ne con assi di allungamento, rispettivamente, a 120° (a.p.2) e a 130° (a.p.1). le direzioni 120°-130° corrispondono ad un sistema di faglie ortogonali alla costa. the bathymetric map highlights a tract of the platform without incision until 70 m depth; an evident canyon with the axis (a.c.) oriented 130° until 1000 m depth; 2 promontories in the sw and ne part with axes respectively oriented 120° (a.p.2) and 130° (a.p.1). the directions 120°-130° correspond to a faults system perpendicular to the coast. l. carobene, m. firpo & a. rovere potrebbe essersi sollevato (nell’arco di 1,8 milioni di anni) di 270 m al massimo; il terrazzo a 180-185 m, in base a tale valore, avrebbe quindi 1,2 milioni di anni. in realtà si ritiene che tale ordine terrazzato sia più antico, in quanto il valore del tasso di sollevamento è sicuramente stato più alto nel pliocene medio e superiore, mentre è andato via via calando nel quaternario. ciò si può dedurre con certezza dalla quota del tirreniano (mis 5.5) osservabile nella vicina grotta di bergeggi (pochi chilometri a sud – vedi fig. 2), pari a 5,20 metri (carobene & firpo, ricerca in corso). ciò documenterebbe un sollevamento tettonico massimo di 0,04 mm/a, ponendo l’originale paleolivello alla stessa quota del livello attuale. un relitto del terrazzo a 35÷45 m è considerato il lembo indicato con rt in fig. 1; esso si presenta rimodellato da eventi successivi, in particolare da livelli di stazionamento marino più bassi. esso è circondato da aree fortemente antropizzate, che non sono state quindi prese in considerazione. il lembo indicato con pat in fig. 1 corrisponde, invece, ad un relitto dell’antica piana alluvionale riferibile al periodo dell’alto eustatico tirreniano (mis 5.5). al suo interno sono stati ritrovati (bulgarelli, 2007) resti romani e della tarda età del ferro (v. cap. 7). la superficie dell’area pat presenta quote massime di 9-10 m, e si eleva con evidenza dall’area circostante: a ne le quote variano da 5 m fino alla linea di riva attuale; a so le quote partono da 7,5 m circa, per salire poi progressivamente verso monte; a se, oltre il t. segno, l’area si presenta decisamente depressa, con quote tra 2 e 5 m sul l.m.m. l’area indicata con pat testimonia sicuramente un relitto dell’antica piana (o area di retrobarriera) riferibile alla trasgressione tirreniana. essa è stata poi incisa ed erosa durante il periodo glaciale würmiano e ricoperta da depositi fangosodetritici provenienti dai versanti. i dati sopra esposti hanno permesso di ricavare il quadro tettonico e dinamico dell’area nel corso del plio-quaternario; esso permette di ritenere che, durante l’olocene, siano stati impercettibili i movimenti verticali di origine tettonica lungo la fascia costiera emersa e sottomarina esaminata. ciò è deducibile anche dallo studio degli spessori dei sedimenti quaternari, e in particolare olocenici, presenti sulla piattaforma continentale (corradi et alii, 1984; fanucci et alii, 1984). 3. prospezioni sismiche e stratigrafia dei sondaggi l’area marina antistante la foce del t. segno è stata oggetto di rilievi sismici ad alta risoluzione mediante apparecchiatura boomer; i profili sismici, effettuati sia perpendicolarmente, sia parallelamente alla costa (fig. 3) hanno fornito indicazioni molto accurate sulle strutture dei sedimenti, consentendo il riconoscimento di 4 corpi sedimentari principali, separati da orizzonti riflettenti molto netti (linee 2-3-4-5 in fig. 4b). lo studio sedimentologico dei sondaggi ha permesso la loro attribuzione all’olocene (v. cap. 4) e di riconoscere che essi poggiano su un deposito prevalentemente ruditico, attribuito genericamente al würm; questo a sua volta si sovrappone ad argille siltoso-marnose grigio-azzurre del pliocene inferiore. la prospezione sismica, effettuata nel settembre 2003, è stata integrata da 13 sondaggi effettuati in parte nel 2003 (bh1, bh2 e bh3) e in parte nel luglio del 2004 (da sg1 a sg10). lo studio si è concentrato in particolare sul profilo sismico lungo il quale si trovano allineati 9 carotaggi (fig. 3), dal bh2 a terra al sg1 a mare; la distanza tra questi è di oltre 600 m. profili e sondaggi hanno permesso di ricavare conoscenze su un’area significativa e abbastanza vasta, estesa dalla batimetria di circa 20 m fino ad un centinaio di metri a monte dell’attuale linea di riva. il substrato è stato indagato da una profondità massima di 35 m (sondaggi sg1, sg2 e sg3) ad una minima di 10 m (sondaggio sg6). sulle carote prelevate si è proceduto ad una descrizione “continua” dei caratteri macroscopici, al fine di individuare ogni variazione di granulometria, di colore, di contenuto in fossili e parti vegetali. ciò ha dato la possibilità di ricavare subito i limiti tra corpi 437 fig. 3 mappa dei profili sismici e dei carotaggi effettuati nell’area di vado ligure. map of the seismic profiles and core drillings made in the vado ligure area. legend: 1) bathymetry; 2) core drillings; 3) seismic profiles; 4) harbour infrastructures. le variazioni ambientali ... diversi per tessitura, struttura, litologia, alterazione o, in ogni caso, separati da superfici di discontinuità. sulla base di queste distinzioni è stata effettuata una campionatura mirata, al fine di ricavare, da analisi di laboratorio, ulteriori e più precisi aspetti dei corpi riconosciuti con le osservazioni preliminari. di norma sono stati prelevati da 2 a 6 campioni per ogni metro di carotaggio, per un totale di circa 650 campioni. le successive analisi di laboratorio hanno permesso di confermare o di meglio definire i caratteri tessiturali dei sedimenti e, in particolare, di ottenere la separazione del contenuto in gusci e in materiale organico. quest’ultimo (resti vegetali di posidonia oceanica) è stato utilizzato per effettuare 25 datazioni c14 (vedi cap. 4). le caratteristiche litologiche e sedimentologiche delle carote hanno permesso di definire meglio i singoli corpi sedimentari riconosciuti, che sono risultati differenti per età e per genesi. la descrizione dettagliata degli aspetti granulometrici e delle principali caratteristiche sedimentarie è riportata in fig. 5 (descrizioni relative alle suddivisioni utilizzate in tab.1). 3.1. i principali corpi sedimentari riconosciuti 1)argille marnoso-siltose del pliocene inferiore. la base dei sondaggi più esterni (sg1, sg2, sg3) ha evidenziato la presenza di argille marnoso-siltose massicce, compatte, spesso indurite, attribuibili al pliocene inferiore. esse non sono state oggetto di studi particolari, in quanto non utili alla comprensione del tema in oggetto. le argille marnose plioceniche si presentano più o meno siltose; il colore può essere: grigio, grigio-verdastro, grigio-giallastro, grigio-azzurro e grigio scuro (fig. 6). al suo interno è spesso visibile tritume conchigliare in quantità variabile, a volte diffuso, a volte concentrato in livelli decimetrici; presenti anche grosse conchiglie e, nella carota sg3, anche clasti spigolosi sparsi. le argille sono normalmente ricche di microfauna che documenta una sedimentazione di mare profondo, di tipo epibatiale, riferibile ad un periodo di alto eustatico relativo. la deposizione nella piattaforma continentale avveniva in un contesto morfologico e strutturale caratterizzato da horst e graben originatisi a seguito della tettonica distensiva che caratterizzò il mar ligure al termine del miocene (corradi et alii, 1984). i sedimenti, trasportati dai corsi d’acqua, si depositavano in mare lungo valli sommerse, dando origine ad estesi conoidi profondi. le argille plioceniche costituiscono il substrato antico che compare (nei sondaggi) tra -15 e -35 m in sg1, tra -16,7 e -35 m in sg2 e tra -31,2 e -35 m in sg3. l’assetto stratigrafico ha fornito una indicazione indiretta non trascurabile; nel sondaggio sg1, infatti, il 438 fig. 4 a) profilo sismico lungo l’allineamento sg1-sg6. b) andamento delle superfici riflettenti. sono numerate da 1 a 5 le superfici più marcate e più continue. a) seismic profile along the alignment sg1-sg6. b) trend of the reflection surfaces. the more continuous and well-marked surfaces are numbered from 1 to 5. l. carobene, m. firpo & a. rovere top del pliocene si trova solamente 1,5 m più basso della base del corpo marino olocenico, separato da ruditi würmiane; nel sondaggio sg2 lo spessore delle ruditi würmiane comprese tra i l pliocene e la base del corpo olocenico è di 2,30 m. questo debole spessore di deposito continentale permette di dedurre che l’area non ha subito subsidenza apprezzabile. 2) silt sabbioso-argillosi alterati del pliocene inferiore. la litofacies compare tra –18,1 e -15 m nel sondaggio gs1, tra -20 e -16,7 m in gs2 e tra -33 e -31,2 m in gs3. il sedimento è poco indurito, a volte plastico, ed è costituito generalmente da silt sabbioso, silt sabbioso-argilloso e silt argilloso. sono presenti localmente fossili marini. il colore da grigio diventa giallastro o color ocra-bruno (5y 4/2) al passaggio con la litofacies superiore, probabilmente per l’alterazione causata dall’esposizione agli agenti esogeni. in gs1 i colori variano da 5y – 4/1 a 5yr – 5/8 e 4/6. quanto descritto, pertanto, rappresenta la coltre d’alterazione del substrato pliocenico, rimasto esposto alla degradazione meteorica dopo i violenti processi erosivi che portarono alla completa asportazione della copertura marina tirreniana sicuramente esistente. 3) ruditi würmiane. nei sondaggi sg1, sg2, sg3 è visibile un brusco cambio litologico testimoniato dal passaggio dalla sedimentazione pelitica marina pliocenica ad una ruditica (conglomerati o brecce) continentale (fig. 7). tali apporti detritici, riscontrati in 5 dei carotaggi a mare ed in bh3, si sono deposti in gran parte durante il periodo würmiano, in ambiente continentale. il deposito continentale würmiano è costituito da clasti spigolosi e arrotondati in percentuali variabili; il diametro dei clasti varia da meno di 1 cm a più di 10 cm; la matrice è più o meno abbondante, da limosa a sabbiosa. questi caratteri conferiscono notevole diversità d’aspetto non solo tra un sondaggio e l’altro, ma anche nell’ambito di uno stesso sondaggio. i vari aspetti riscontrati sono i seguenti: a) ciottoli quarzosi e metamorfici, in prevalenza arrotondati, di diametro inferiore a 3 cm, in matrice sabbioso-siltosa; 439 litologia della formazione olocenica / lithology of the holocenic formation sigla / label ghiaia gravel gh sabbia sand s silt silt si argilla clay a formazioni pre-oloceniche / pre-holocenic formations sigla / label rudite würmiana würmian rudite rw argille plioceniche pliocenic clays ap colore / color sigla / label nero black -ne grigio gray -gr marrone brown -ma giallastro yellow -gi chiaro bright .chi scuro dark .scu strutture / structures sigla / label livello(i) level(s) -li lamina(e) isolata(e) thin bed (s) -la sedimento gradato graded sediment -g sedimento laminato laminated sediment -l fossili / fossils sigla / label fossili fossils -f piccoli gusci little shells -pg tritume organogeno organic crumbs -to inclusi organici / organic matter sigla / label matte morta di posidonia oceanica posidonia oceanica dead matte -p sostanza organica organic matter -so carboni coal -ca percentuale / percentage sigla / label scarso scarce .sc abbondante abundant .ab ordine / sequence litologia della formazione olocenica / colore / strutture / fossili / sostanza organica / percentuale lithology of the holocenic formation / color / structures / fossils / organic matter / percentage tab. 1 sigle utilizzate per la descrizione sedimentologica delle singole suddivisioni riportate in fig. 5. nella descrizione della litologia, due o più sigle non sono separate da trattino; la seconda o la terza sigla sono in questo caso aggettivi. nel caso di più livelli o lamine, il simbolo “li” o “la” viene preceduto dal numero. labels used in the sedimentological description of the single subdivisions reported in fig.5. in the description of the lithology, two or more labels are not separated by an hyphen; the second or third labels are in this case adjectives. in case of more lamins or levels, the symbols “li” or “la” is preceded by their number. le variazioni ambientali ... b) clasti da spigolosi ad arrotondati, eterometrici, con diametri fino a 12 cm, in prevalenza metamorfici, con matrice limosa abbondante; c) clasti eterometrici, da pochi millimetri a 6 cm, in prevalenza arrotondati, in matrice limosa scarsa; d) clasti spigolosi, con diametri fino a 2-3 cm, sparsi in matrice limoso-argillosa predominante; e) clasti con discreto arrotondamento, con prevalenza di diametri di 1-2 cm, in matrice sabbiosa abbondante; f) depositi ruditici più o meno gradati, in matrice di sabbia siltosa, prevalente in alto. diametri alla base di 2-4 cm; g) deposito prevalentemente composto da sabbia da fi g. 5 s tr at ig ra fia d ei s on d ag gi d a s g 1 a s g 6. p er o gn i s on d ag gi o è in d ic at a la li to lo gi a p re d om in an te ; n el la c ol on na d i d es tr a so no in ve ce in d ic at e le s ud d iv is io ni e ff et tu ate . i l s ig ni fic at o d el le s ig le u til iz za te è r ip or ta to in t ab .1 s tr at ig ra p hy o f th e co re d ril lin gs f ro m s g 1 to s g 6. f or e ac h co re t he d om in an t lit ho lo gy is in d ic at ed ; in t he r ig ht c ol um n ar e re p or te d t he a d op te d s ub d iv is io ns . th e si gn ifi ca nc e of t he la b el s is r ep or te d in t ab .1 440 l. carobene, m. firpo & a. rovere tinua di tritume conchigliare o di gusci interi; dalla comparsa in determinati livelli di resti di posidonia; dalla laminazione che può essere presente o meno e, infine, dal colore variabile dal grigio chiaro al nero. la combinazione di questi caratteri definisce corpi aventi un ben preciso significato, legato essenzialmente al processo trasgressivo e al raggiungimento delle condizioni finali di alto eustatico. vengono di seguito descritti sinteticamente gruppi di litofacies, sulla base di alcune caratteristiche predominanti. le singole facies, definite su base prevalentemente granulometrica, sono riportate in fig. 5. facies del corpo trasgressivo comprese tra gli orizzonti 2 e 3: (fig. 8) a-facies a sabbia gradata con ciottoletti compare al top della litofacies continentale attribuita al würmiano. in sg1, tra 13,45 e 12,05 m, inizia con ciottoletti arrotondati, il cui diametro può arrivare a 5 cm, immersi in abbondante sabbia da media a fine. verso l’alto la granulometria diminuisce progressivamente, fino a sabbie finissime siltose. il colore è brunogiallastro (10yr-5/4), probabilmente causato dall’erosione del substrato würmiano pedogenizzato. in sg4, tra 14,40 e 13,90, si ripete la stessa situazione, con diametro dei ciottoli alla base fino a 7 cm; il colore è 7.5yr-5/4 (fig. 9). questa facies è indicativa di una fig. 6 aspetto delle argille marnose attribuite al pliocene inferiore. il cartello indica il sondaggio e la profondità. aspect of the marly clays attributed to lower pliocene. the tablet shows core number and depth. fig. 7 deposito attribuito al periodo würmiano (ultimo glaciale). è possibile osservare la facies (c) con clasti abbondanti; la facies (b) prevalentemente sabbiosa e la facies (g) composta da sabbie fini (al centro) (vedi testo). deposit attributed to würmian (last glacial). facies (c) with an abundant amount of pebbles; facies (b), mainly sandy and facies (g), composed by fine sands (in the center) are recognisable (see text for details). medio fine a fine, siltosa, ricca di clasti millimetrici, a volte gradato; h) deposito prevalentemente composto da sabbia grossolana, mal classata, con clasti sparsi aventi diametro massimo di 1 cm. l’abbondanza delle facies è indicativa della varietà dei processi subaerei che hanno contribuito alla deposizione di questo corpo sedimentario, la cui origine è sicuramente continentale. da sottolineare i continui passaggi tra orizzonti ricchi di clasti spigolosi, oppure spigolosi e arrotondati, fino a passare ad orizzonti con clasti prevalentemente arrotondati. interessante anche la mescolanza oppure la separazione tra clasti metamorfici e clasti quarzosi bianchi; infine le variazioni granulometriche della matrice, da siltosoargillosa a sabbiosa. il colori munsell misurati variano da 2,5 y (3/6, 5/2, 5/4, 5/6) a 7yr (4/4, 5/6) fino a 10yr (4/4, 4/6, 5/6, 5/8, 6/6, 6/8); essi sono indicativi dell’alterazione subita dal deposito durante il prolungato periodo di esposizione agli agenti atmosferici che ha preceduto la trasgressione olocenica. in conclusione, il deposito descritto è il risultato di prevalenti episodi di trasporto in massa, con colate ora prevalentemente fangose, ora prevalentemente detritiche; non mancano episodi dove è riconoscibile un trasporto trattivo da corrente ad alta concentrazione. la pendenza delle superfici di deposizione non superava i 2°. 4) depositi marini olocenici. sono caratterizzati da granulometrie variabili dalle sabbie con ghiaietto alle argille; dalla presenza discon441le variazioni ambientali ... fig. 8 l’analisi sedimentologica dei sondaggi ha portato al riconoscimento del substrato pliocenico (p), che si presenta alterato per alcuni metri nella sua parte superiore; dei depositi ruditici würmiani (ultimo glaciale) (w); del deposito marino olocenico (o). the sedimentological analysis of the core drillings leaded to the recognition of the pliocene substratum (p), that was found to be altered for some meters in its lower part; of the würmian rudite (last glacial) (w); of the holocene marine deposit (o). fig. 9 sabbie siltose laminate nel sondaggio sg3 (tra 15,40 e 15,50 m circa vedi fig.5). il colore è 10 yr 5/4. laminated silty sands in the sg3 core (between nearly 15,40 and 15,50 m see fig.5). the munsell colour is 10 yr 5/4. 442 l. carobene, m. firpo & a. rovere linea di riva (battigia) che si spostava velocemente verso terra, a causa del rapido innalzamento eustatico (circa 10 mm/a in questo tratto). nel suo spostamento essa andava a ricoprire o a distruggere la facies descritta successivamente. b-facies a silt laminati e argillosi con sostanza organica compare direttamente sopra alla superficie trasgressiva in 3 sondaggi. in sg2, tra 14,45 e 13,80 m, compaiono silt laminati grigio-giallastri a volte leggermente gradati. sono sovrapposti a 20 cm di clasti in prevalenza arrotondati, con diametri compresi tra 2 e 4 cm, immersi in matrice sabbioso-limosa. i silt laminati sono ricoperti in alto, tramite una superficie erosiva, dalle “sabbie e silt sabbiosi di color grigio” del corpo trasgressivo di spiaggia (fig. 10). in sg3, tra 15,75 e 14,90 m, si riconoscono sabbie fini siltose bruno-grigiastre (2.5y–5/4 e 5/2), alterate nella parte alta (10 yr-4/6 e 4/4), ricoperte da argille siltose scure, ricche di resti carboniosi. infine, in sg5, tra 14,80 e 10 m, compaiono sabbie fini siltose, nettamente laminate (lamine siltoso-argillose e lamine siltoso-sabbiose) di colore bruno-giallastro (2.5y-6/4). il colore, anche in questo caso, dovrebbe derivare dal rimaneggiamento dei sottostanti depositi würmiani pedogenizzati. la facies indica decantazione lenta di peliti in ambiente di retrospiaggia. c-facies a silt nerastro con contenuto organico compare con spessore massimo di 40 cm, tra sg1 e sg4. si presenta come un silt più o meno argilloso, di colore grigio-scuro nerastro, ricchissimo di sostanza organica, di resti vegetali ed anche (in sg3) di tritume conchigliare. la mancanza di dati specifici su questi resti permette due interpretazioni: il deposito potrebbe indicare gli effetti dello spostamento della linea di riva all’interno della piana del t. segno, causata dall’innalzamento del livello marino. l’aumento della batrimetria avrebbe diminuito drasticamente l’energia sul fondo e così pure il tasso di sedimentazione. come seconda ipotesi, il silt argilloso nerastro potrebbe essere la testimonianza di un ambiente lagunare (o di retrobarriera) ricoperto dalle sabbie trasgressive sovrastanti. d-facies a sabbie e silt sabbiosi di color grigio questa litofacies e quella maggiormente rappresentata tra gli orizzonti 2 e 3; il suo spessore raggiunge un massimo di 5 metri i corrispondenza dei carotaggi sg6, bh1 e bh3 (fig. 10). il deposito è a volte ricco di tritume organogeno o presenta livelletti a piccoli lamellibranchi. la granulometria tende a diventare più fine verso l’alto. il colore grigio, spesso chiaro, indica buona ossigenazione e carenza di sostanza organica. litofacies compresa tra gli orizzonti 3 e 4: (fig. 8) facies a silt argilloso nero con tritume organogeno è ben riconoscibile in sg1 tra 10,20 e 9 m; in sg2 tra 10,60 e 9 m; in sg3 tra 11,20 e 8,75 m; in sg4 tra 10,20 e 8 m; in sg5 tra 9,70 e 7,50 m; in sg6 tra 7,70 e 5,30 m. rari i livelletti di silt con fossili o tritume organogeno. a volte è presente la posidonia. il corpo argilloso rappresentato da queste facies corrisponde ad una deposizione pelitica distale, quando la linea di riva stazionava all’interno dell’attuale piana del t. segno, dopo aver raggiunto il punto di massima ingressione. si può immaginare che, in questa situazione paleogeografica, il materiale più grossolano si depositasse in gran parte nell’area di retrospiaggia. litofacies compresa tra gli orizzonti 4 e 5: (fig. 8) facies a sabbie e silt di color grigio con posidonia oceanica si differenzia nettamente dalla sottostante per la presenza di sabbia e per il colore prevalentemente più chiaro, mentre il passaggio con la sovrastante è sfumato. si riconoscono diversi aspetti: in sg3 alla base compare un livello gradato a ghiaietto e sabbie; in altri casi la facies inizia con sabbie siltose o silt sabbioso con o senza fossili. caratteristica è la presenza di più cicli gradati consecutivi con sabbia fine o silt sabbioso in basso, di colore grigio chiaro, passante a silt grigio scuro in alto, a volte argilloso, con posidonia e resti organogeni. la facies termina in prevalenza con silt o silt argilloso scuro con posidonia. la litofacies è la conseguenza della prima fase di alto stazionamento eustatico, tra 5000 e 1800 anni fa, caratterizzata dal riempimento progressivo della piana attuale del t. segno e dalla conseguente progradazione della linea di riva verso la sua attuale posizione; posizione che probabilmente era già delineata da barre o da frecce litorali. all’esterno di queste, la sedimentazione riprende dopo la stasi della fase precedente; il fondale si rinnova continuamente con nuovi apporti terrigeni e prosperano organismi sul fondo e le praterie di posidonia. gli orizzonti riflettenti (fig. 8) sono chiaramente in downlap sulla sottostante litofacies. litofacies compresa tra la superficie 5 e l’attuale fondale: facies a silt argillosi nerastri prevalgono silt argillosi neri e argille siltose nere, oltre a silt argillosi con posidonia. la litofacies comprende anche livelli sottili di silt e silt sabbiosi con o senza posidonia. lo spessore è minimo verso riva, mentre aumenta verso il largo, raggiungendo i 7 metri di spessore nel sondaggio più esterno. il corpo sedimentario si è deposto negli ultimi 1800 anni, come risposta all’alto stazionamento eustatico e alla stabilizzazione della linea di riva su una posizione simile all’attuale (cap. 4). 3.2. considerazioni stratigrafiche l’analisi degli orizzonti visibili nel profilo sismico, integrata dal riconoscimento delle litofacies sopra fig. 10 in alto è visibile la sedimentazione di retrobarriera, costituita da silt argilloso nerastro, con resti vegetali carboniosi e tritume di conchiglie. nella parte bassa della foto compaiono silt grigi del sedimento trasgressivo. nota: la polarità nella colonna stratigrafica è rivolta verso il basso. (sondaggio sg3 da 15 a 14,75 m circa). on the top the retrobarrier sedimentation, constituted by black clayey silt, which becomes rich of carbonic plant remains and crumbs of shells, is visibile. in the lower part of the photo gray silts assigned to the transgressive sediment are visible. note that the stratigraphic column is reversed (core sg3, from about 15 to 14,75 m). 443le variazioni ambientali ... descritte, ha permesso una ricostruzione dell’andamento del substrato pre-olocenico e del corpo olocenico (fig. 8). la geometria del top del pliocene (osservabile lungo questo profilo sismico) è interpretabile come una sezione del paleoalveo del t. segno che, durante l’abbassamento eustatico würmiano, ha eroso tutti i sedimenti tirreniani preesistenti, fino ad incidere direttamente il substrato pliocenico. l’alveo aveva in questo punto (tra sg3 e sg4) una profondità di circa 15 m ed una larghezza reale di 100-150 metri. in figura la larghezza è “apparente”, in quanto la direzione del paleoalveo non è perpendicolare alla direzione del profilo sismico, ma la interseca con un angolo di 10-20°; l’alveo aveva una probabile direzione verso ese. l’andamento del top del pliocene è stato controllato nel carotaggio bh3; inoltre, come esposto nel cap. 1, il pliocene affiorante nell’entroterra fino ad una quota massima di 100 m ha fornito un altro punto di verifica. alla fase prettamente erosiva del segno è poi seguita la fase o, meglio, le fasi deposizionali che hanno originato il corpo ruditico, continentale, attribuito al würm. la risalita olocenica del mare ha tagliato, in maniera non quantificabile, i depositi würmiani (orizzonte 2), depositandovi sopra uno spessore di circa 14 m di sedimenti marini. la fig. 8 dà quindi un’idea concreta, anche se limitata nello spazio, dei processi e dei cambiamenti avvenuti nell’area. nei capitoli successivi verrà meglio definito il corpo olocenico. 4. le datazioni c14 il rilievo sismico (fig. 4) ha permesso di riconoscere (cap. 3) numerose superfici di riflessione (riflettori sismici) più o meno marcate e continue. le superfici più significative, indicate con 2, 3, 4 e 5, sono state riportate con semplici proporzioni sulle carote sg1 – sg6 (fig. 5); esse coincidono con superfici di passaggio (limiti) tra sedimenti diversi per una o più fig. 11 la stratigrafia riportata in fig. 5 e l’interpretazione del profilo sismico hanno permesso di riconoscere, all’interno del deposito olocenico, i 5 corpi principali riportati in figura. ap: argille plioceniche; rw: rudite würmiana. 2, 3, 4 e 5: superfici riflettenti principali riconosciute in fig. 8. the stratigraphy reported in fig. 5 and the interpretation of the seismic profile allowed to recognize, inside the holocenic deposit, the 5 bodies reported in the figure. ap: pliocene clays; r: würmian rudite. 2, 3, 4 and 5: reflecting surfaces recognised in the fig. 8. 1)lagoon or retrobarrier silty sand and pebbly sand. 2) silt and sandy silt of the transgressive body in onlap on the substrate (between 9000 and 6000 yrs bp). 3) silt and clayey silt of the high stand (between 6000 and 5000 yrs bp). 4) silt, sandy silt and clayey silt of the progradational body in downlap on 3 (between 5000 and 1800 yrs bp). 5) clayey silt and sandy silt of the high eustatic stand (final.) 6) erosive surface. 444 l. carobene, m. firpo & a. rovere caratteristiche, quali granulometria, colore, contenuto in sostanza organica (posidonia oceanica) e tritume organogeno. la correlazione tra detti limiti ha portato al riconoscimento di 4 corpi sedimentari marini principali (fig. 11), all’interno dei quali le “linee” che appaiono sul profilo sismico (fig. 8) possono essere considerate “superfici isocrone”, riconducibili quindi a “superfici di strato”. per definire la cronostratigrafia sono state effettuate datazioni c14, in gran parte su resti di posidonia; il materiale organico è stato estratto dal sedimento mediante lavaggio e asciugato in forno. l’abbondanza di resti di posidonia ha permesso 13 datazioni radiometriche standard, mentre in altri 12 casi (con piccole quantità di posidonia) la datazione è stata del tipo ams. la tab. 2 riporta l’elenco complessivo di tutte le datazioni effettuate, con indicazione dell’intervallo calibrato 2 sigma before present. due datazioni sono state effettuate su campioni di conchiglie (sg3-97 e sg1-187); quest’ultimo campione non ha fornito una data congruente con la sua posizione stratigrafica. l’altra datazione è stata effettuata su legno ma, anche in questo caso, è risultata inattendibile. due datazioni ams, inoltre, riguardano materiale carbonioso contenuto nell’argilla. le date desunte dai campioni sg3-97 e sg3-107 non sono state utilizzate in quanto è nota solamente l’età convenzionale. le datazioni c14, i dati lito-stratigrafici ricavati dallo studio di tutte le carote (fig. 5), le suddivisioni scaturite dalla interpretazione del profilo sismico (fig. 8), sono state utilizzate per definire la cronostratigrafia del deposito olocenico. sul profilo sismico interpretato (fig. 4b) sono state ubicate tutte le date calibrate attendibili e congruenti, tenendo conto anche del sondaggio sg6. i valori di età sono stati correlati tra loro parallelamente alle superfici riflettenti; le incongruenze di età sono risultate inferiori al 5-10% ed hanno permesso di ricavare le superfici isocrone a 8000, 7000, 6000, 5000 e 1800 anni b.p. (fig. 12). la superficie a 6000 anni coincide con la superficie 3 individuata in fig. 4b; le superfici a 5000 e 1800 anni coincidono con le superfici sismiche 4 e 5 che racchiudono il corpo progradante già descritto al paragr. 3.1. tra la superficie basale 2 e la superficie 3 si sviluppa il corpo trasgressivo. nel dettaglio, le considerazioni cronologiche effettuate sulla fig. 12 sono di seguito riportate. il corpo trasgressivo, caratterizzato da “linee isocrone” in onlap sulla superficie basale erosiva (linea 2), risulta cronologicamente definito da 2 date massime: 8275 ± 95 anni (in bh3-21.70) e 8120 ±160 anni (in sg3-96) e da 2 minime: 7340 ± 80 anni (in sg5-331) e 6820 ± 160 anni (in sg6-428). la superficie 3 chiude in alto la sequenza trasgressiva; detta superficie costituisce la base del corpo che termina, con la superficie 4, a 5000 anni (vedi avanti). la posizione e la datazione della superficie 3 risulta coerente con la diminuzione del tasso di sedimentazione che si verifica a mare a partire da 7000 anni b.p. tab. 2 è riportato l’elenco dei campioni prelevati (col. 2) nei vari sondaggi (col. 1), il materiale utilizzato per la datazione (col. 3), la tecnica utilizzata (col. 4), l’intervallo di età (2-sigma calibrated) (col. 5) e un valore medio calcolato, utilizzato nelle figure (col. 6). con l’asterisco le età risultate non congruenti. the table reports the listing of the samples (col. 2) took from the core drillings (col.1), the material used for dating (col. 3), the technique used (col. 4), the age interval (2-sigma calibrated) (col. 5) and a mean value calculated, used in the figures (col. 6). the asterisk indicates the inconsistent data. sondaggio campione materiale tecnica età calibrate bp valore medio bh3 21.70 mat. carbonioso ams 8370-8180 bp 8225 bh3 15.45 posidonia standard 6270-5920 bp 6095 m1 us0 posidonia ams 2350-2160 bp 2265 m1 us9 posidonia ams 2360-2180 bp 2270 m1 us10 posidonia ams 2350-2160 bp 2205 sg1 187 conchiglie ams *920-750 bp sg1 193 legno ams *490-290 bp sg2 241 posidonia ams *2790-2730 bp sg2 247 posidonia ams 1410-1300 bp 1355 sg3 97 conchiglie standard *6745±50 (convenz.) sg3 107 posidonia standard *1569±50 (convenz.) sg3 96 posidonia standard 8280-7960 bp 8120 sg3 104 posidonia ams *4080-3840 bp sg3 117 posidonia standard 2100-1860 bp 1980 sg3 128 posidonia ams 540-480 bp 510 sg4 277 posidonia standard 8000-7710 bp 7855 sg4 291 posidonia standard 5450-4970 bp 5210 sg4 305 posidonia standard 2150-1880 bp 2015 sg5 331 mat. carbonioso ams 7420-7260 bp 7340 sg5 339 posidonia ams 4820-4450 bp 4635 sg5 349 posidonia standard 2130-1880 bp 2005 sg5 351 posidonia standard 1290-1160 bp 1225 sg6 428 posidonia standard 6980-6660 bp 6820 sg6 440 posidonia standard 3900-3560 bp 3730 sg6 449 posidonia standard 1710-1520 bp 1615 445le variazioni ambientali ... il corpo pelitico (con spessore compreso tra 2,30 e 1,20 m), racchiuso tra le superfici 3 e 4 è considerato la risposta distale allo stazionamento avvenuto all’interno della (attuale) piana del t. segno tra 6000 e 5000 anni fa; esso è cronologicamente definito da 2 datazioni: 5210 ± 240 anni (sg4-291) e 4635 ± 185 anni (sg5339) che hanno permesso di inquadrarlo tra 6000 e 5000 anni dal presente, tenendo anche conto della data di 6820 anni in sg6. non congruente risulta invece la data di 3960 anni in sg3. nel sovrastante corpo progradante le linee sono in downlap sulla superficie 4; i depositi risultano pertanto via via più recenti verso mare. la sequenza progradante è inquadrabile cronologicamente sulla base di 5 date che ricadono al suo interno; la più antica (3730 ± 170 anni in sg6-440) è anche a più bassa stratigraficamente; la più recente (1355 ± 55 in sg3-247) è la più alta stratigraficamente. le date 2015 ± 135 (sg4 305) e 2005 ± 125 (sg5 – 349), considerati i rapporti geometrici esistenti con la posizione della data 1980 ± 120 (sg3 117), definiscono il top del corpo a circa 1800 anni b.p. pertanto la sequenza progradante ricade nell’intervallo 5000-1800 dal presente. la sedimentazione marina degli ultimi 1800 anni ha generato un corpo (sovrastante la linea 5) avente “linee riflettenti” divergenti verso il largo (fig. 12); esso presenta i minimi spessori verso terra (1,5 – 2 m) e i massimi verso mare (7 m in corrispondenza di sg1). la sua età è confermata da 3 datazioni: 1615 ± 95 anni (sg6-449); 1225 ± 65 anni (sg5-351) in posizione medio-bassa e 510 ± 30 anni (sg 3-128) in posizione medio-alta. in conclusione, le datazioni c14 si sono mostrate nella maggior parte dei casi coerenti tra loro e determinanti per la definizione cronologica, sedimentologica e geometrica del corpo sedimentario olocenico. 5. la risalita eustatica l’interpretazione cronostratigrafica del profilo sismico ha permesso di individuare 5 “superfici isocrone datate” (fig. 12); esse risultano corrispondenti ad altrettanti “superfici riflettenti” individuate dalla sismica, ovvero a “superfici di strato”. questi strati si chiudono verso terra in corrispondenza di “linee di riva” aventi la stessa età. poiché nella figura citata nessuna delle 5 superfici datate si chiude sulla superficie basale trasgressiva, le quote delle linee di riva rimangono indeterminate. fig. 12 interpretazione cronostratigrafica del profilo sismico basata sulle età calibrate c14. sono state tracciate 5 “superfici isocrone” parallele alle “superfici riflettenti” del profilo. esse corrispondono a superfici di deposizione che documentano le tappe della crescita del corpo sedimentario in seguito alla risalita eustatica olocenica. le superfici 2, 3, 4, 5 sono le stesse di fig. 8. chronostratigraphic interpretation of the seismic profile, based on the c14 calibrated data. were obtained 5 “isochronal surfaces” parallel to the “reflecting surfaces” of the seismic profile. they correspond to depositional surfaces that evidence the growing stages of the sedimentary body after the holocenic eustatic sea level rise. the surfaces 2, 3, 4, 5 are the same shown in fig. 8. 446 l. carobene, m. firpo & a. rovere 5.1. la determinazione delle antiche linee di riva al fine di definire gli aspetti stratigrafici e morfologici della trasgressione olocenica anche verso terra, ovvero nell’area non coperta dai profili sismici, è stata costruita la sezione a-b (vedi la traccia in fig. 1). il profilo del fondovalle attuale del t. segno (a partire dalla quota 22 m) è stato unito all’antistante fondale marino ricavato dalla sismica (fig. 4), ottenendo in tal modo il profilo topografico riportato in fig. 13. la superficie di appoggio del deposito marino olocenico sul substrato würmiano (tratto cd), è stata unita al tratto de, tracciato a partire da e dove è nota la profondità del substrato roccioso (quota di 17 m circa). il profilo cde costituisce “l’andamento regolarizzato della superficie topografica würmiana” (asw), oggi ricoperta dai sedimenti marini trasgressivi verso mare e dalle alluvioni e dai conoidi verso terra (fig. 13). i due profili così ricavati definiscono “lo spazio sedimentario” entro il quale si chiudono le superfici isocrone di 8000, 7000, 6000 e 5000 anni individuate in fig. 12. di queste, le prime tre fanno sicuramente parte del corpo trasgressivo, e quindi sono in onlap sulla superficie basale asw, mentre la superficie a 5000 anni è la base del corpo progradante compreso tra le superfici 4 e 5 (fig. 12). l’intervallo cronologico tra 6000 e 5000 anni segna pertanto l’arresto della trasgressione verso terra e l’inizio della formazione di un cordone di spiaggia che si stabilizza in una data posizione e che si accresce seguendo l’innalzamento eustatico, dando origine al corpo pelitico marino (silt e silt argillosi nerastri) racchiuso tra le superfici 3 e 4 (fig. 11 e fig. 12). a monte del cordone di spiaggia (ovvero all’interno della piana) si sviluppa il processo di aggradazione dei depositi alluvionali. pertanto, la superficie di 6000 anni fa deve intersecare la base asw nel punto di massima ingressione, mentre il corpo progradante inizia a formarsi solamente a partire da 5000 anni b.p. nel momento in cui inizia la progradazione, il profilo longitudinale dell’alveo (o del fondovalle) del t. segno prosegue a mare con la superficie 4 di deposizione marina di fig. 12. la superficie 4 è quindi la superficie di inizio progradazione, indicata con sip in fig. 13. la superficie sip determina, assieme alla superficie asw, uno “spazio sedimentario molto ristretto” all’interno del quale si devono chiudere le superfici a 8000, 7000 e 6000 anni. ciò ha facilitato il compito di determinare la posizione delle 3 corrispondenti linee di riva. il procedimento è illustrato in fig. 14. i punti fermi della figura sono costituiti: a) da tutti gli elementi contenuti nel riquadro a sinistra; esso corrisponde alla fig. 12. b) dalla superficie 2, corrispondente alla asw riportata in fig. 13. c) dalla superficie 4, corrispondente alla sip della fig. 13. il procedimento è consistito nel tracciare l’andamento della superficie 3 (6000 anni b.p.) parallelo alla superficie limite sip, fino al suo incontro con la superficie basale asw. la superficie si chiude in onlap alla profondità di –3 metri, determinando la posizione della linea di riva nel punto di massima ingressione del mare all’interno della piana costiera del t. segno. analogamente si è proceduto con le restanti superfici a 7000 e a 8000 anni b.p., tracciate tra loro parallelamente e vincolate dalla loro posizione in sg6 (fig. 12). esse determinano sulla superficie asw due linee di riva (rispettivamente) a -6,5 e a -12 m s.l.m. fig. 13 -dalla carta topografica regionale scala 1:10000 è stato tracciato il profilo topografico a-b che raccorda il fondovalle del t. segno con il profilo batimetrico a mare (fondale attuale). la profondità del substrato in (a) ha permesso di tracciare il profilo de, che si raccorda con il substrato cd (sottostante al deposito marino olocenico) ricavato dai sondaggi. la superficie sip (superficie di inizio progradazione) raccorda la superficie datata 5000 anni b.p., ricavata in fig. 12, con il fondovalle venutosi a creare successivamente alla linea di riva di massima ingressione. il forte arrivo di materiale detritico provoca, a partire da 5000 anni fa, prima l’aggradazione, poi la progradazione della spiaggia. la linea di separazione tra depositi marini e depositi continentali è qui indicativa; essa verrà precisata nella fig. 14. from the 1:10000 topographic map was traced the topographic profile a-b, that connects the valley floor of the segno river with the bathymetric profile seaward (current bottom profile). the depth of the substratum in (a) allowed to design the de profile, which is connected to the substratum cd (under the marine holocenic deposit) obtained by the seismic profiles. the surface sip joins the surface dated 5000 yrs bp, obtained by the fig. 12, with the valley floor that formed after the shoreline of maximum ingression. the strong arrival of detrital material caused, starting from 5000 yrs bp, first the aggradation, then the progradation of the beach. the separation line between marine deposits and continental ones is here only indicative; it will be specified in the fig. 14. 1)current bottom profile; 2)marine holocenic deposit; 3)regularized trend of the würmian topographic surface (asw); 4) bed of the segno river; 5)holocene alluvial deposits and conoids; 6)valley floor profile; sip: surface of the starting progradation. 447le variazioni ambientali ... attuale. la stabilizzazione della linea di riva iniziata 6000 anni fa (punto pmi in fig. 14) permette di tracciare un altro elemento fondamentale di tale figura, la curva di spostamento della linea di riva (cslr), dalla posizione di -3 m di 6000 anni fa, alla posizione della linea di riva attuale. dalla intersezione della curva cslr con la “superficie di inizio progradazione” sip si ricava con buona approssimazione anche la linea di riva di 5000 anni fa; la sua profondità risulta pari a -1,5 metri. le profondità delle linee di riva, ricavate con il procedimento sopra descritto, sono state utilizzate per la costruzione della curva di risalita relativa del livello marino. si è calcolato sperimentalmente che i valori di profondità così trovati sono affetti da un errore di circa ±1,5 metri. 5.2. la curva dell’innalzamento del livello marino relativo unendo i quattro valori di profondità trovati per le linee di riva da 8000 a 5000 anni secondo il “modello shepard” (shepard, 1963), si è ottenuta la curva di fig. 15, che visualizza “l’andamento” della risalita eustatica olocenica. la curva si raccorda con la quota 0 del livello mare attuale nel modo più semplice possibile; l’andamento risultante è paragonabile con altre curve simili, anche se ottenute con metodi diversi e in situazioni geologiche molto varie (louwe kooijmans, 1971; jelgersma, 1979; bard et alii, 1996; preti, 1999; lambeck et alii, 2004) e, più in generale, tipiche delle medie latitudini, dove la risalita del mare è avvenuta con velocità in progressiva diminuzione, senza superare l’attuale livello (fig. 3.6 in bird, 2000), in assenza di evidenti effetti glacioisostatici. lo studio effettuato non permette tuttavia di ricofig. 14. nella fig. 13 sono precisati sia “l’andamento regolarizzato della superficie würmiana (asw)” sia “la superficie di deposizione datata 5000 anni fa”, che segna l’inizio della progradazione della spiaggia (sip=superficie inizio progradazione). questi due elementi geometrici hanno permesso di definire la posizione della linea di riva di 8000 anni fa (-11 m), di 7000 anni fa (-6,5 m) e di 6000 anni fa (-3 m). i tre punti sono stati ricavati intersecando con la asw le superfici isocrone determinate in fig. 12; le tre superfici sono state fatte proseguire verso terra con andamento parallelo alla sip, ma in onlap sulla asw. l’intersezione della superficie datata 6000 anni bp sulla asw determina un “punto di massima ingressione” (pmi); in corrispondenza di tale punto la spiaggia si stabilizza e inizia a crescere, determinando il progressivo accumulo di sedimenti lungo il fondovalle del t. segno. la posizione della pmi ha permesso di tracciare la “curva di spostamento della linea di riva” (cslr) da -3 m alla posizione attuale. l’intersezione della superficie sip con tale curva determina la posizione della linea di riva di 5000 anni fa (-1,5 m). t=sequenza trasgressiva; mi=sequenza derivante dal relativo stazionamento della linea di riva; p=sequenza progradante; ase=sequenza relativa all’alto stazionamento eustatico interglaciale. in fig. 13 are highlighted both the “regularized trend of the würmian topographic surface (asw)” and the “deposition surface dated 5000 yrs bp”, that marks the beginning of the progradation of the beach (sip=surface of the beginning of the progradation). these two geometric elements allowed to define the position of the shoreline dated 8000 yrs bp (-11 m), 7000 yrs bp (-6,5 m) and 6000 yrs bp (3 m). the three points were obtained intersecting with the asw the isochronal surfaces showed in fig. 12; the three surfaces were prolonged landward parallele to sip, but in onlap on the asw. the intersection of the surface dated 6000 yrs bp with the asw is a “point of maximum ingression” (pmi); in correspondence of that point the beach became stable and began to grow, causing the progressive accumulation of sediments along the valley floor of the segno river. the position of the line called pmi allowed to obtain the “shoreline shifting curve” (cslr) from -3 m to its current position. the intersection of the sip with this curve gives the position of the 5000 yrs bp shoreline (-1,5 m). t=transgressive sequence; mi=sequence derived from the relative shoreline stand; p=prograding sequence; ase=sequence relative to the high interglacial eustatic stand. 1) prograding emerged beach; 2) bed of the segno river. 448 l. carobene, m. firpo & a. rovere noscere possibili e probabili fluttuazioni del livello marino lungo la curva, come sarebbe logico attendersi dall’analisi delle curve isotopiche o18 ricavate da carote di ghiaccio (esempi in johnsen et alii, 2001; delmonte et alii; 2002). la curva eustatica “modello fairbridge” (fairbridge, 1961) è forse più probabile; essa è stata riproposta dallo stesso autore (fairbridge, 1976) e trova parziali conferme dalle ricerche di altri (hillaire-marcel, 1978; l’homer et alii, 1981; siddall et alii, 2003; molti altri esempi in pirazzoli, 1991, tavv. 32, 33, 34, 35, 36, ecc.). nella curva di fig. 15 la risalita del livello marino tra 8500 e 6000 anni b.p. è avvenuta con una velocità media di 4,6 mm/a, mentre tra 6000 e 5000 inizia a decrescere (1,5 mm/a) e tra 5000 ed oggi si è manifestata con velocità media di 0,3 mm/a; quest’ultimo valore è uguale a quello calcolato da morhange et alii (2001) per la costa provenzale della francia. le velocità indicate non tengono conto della variabilità legata all’errore di valutazione di quota calcolato per le 4 paleolinee di riva. lo studio della trasgressione olocenica lungo il tratto costiero dell’emilia-romagna (tra il po e rimini) ha evidenziato che tra 6500 e 7000 anni b.p., la velocità di risalita relativa del livello marino è passata da valori di 8-10 mm/a a valori inferiori ad 1-1,5 mm/a nel tratto finale (preti, 1999 e 2000). tali valori di innalzamento comprendono anche il valore dell’abbassamento del suolo dovuto alla subsidenza. interessante è il confronto tra l’area di vado e l’area subsidente di pianura ad ovest di ravenna. in località conselice (a 36 km dall’attuale costa) è stato carotato un livello fossilifero di ambiente lagunare tra 9,5 e 7,5 m sotto il l.m. attuale (preti, 1999). un campione a -9 m ha fornito un’età c14 calibrata di 6170 b.p. tenendo conto della subsidenza naturale a lungo termine ricavata da pozzi agip (selli & ciabatti, 1976; pieri & groppi, 1981) e della subsidenza olocenica dedotta dalla profondità della linea di riva di massima ingressione tra cattolica e alfonsine (a no di ravenna), si può stimare per l’area un valore di subsidenza tra 0.5 e 0,8 mm/a (amorosi et alii, 1999; preti, 1999) che, in 6170 anni, corrisponde ad abbassamenti di 3 e di 5 m rispettivamente. pertanto il citato livello a -9 m dovrebbe corrispondere ad una profondità originaria (corretta per la subsidenza) di 6 o di 4 metri. tenendo conto, inoltre, anche della profondità di sedimentazione (nell’ambiente lagunare) del campione raccolto, il livello marino di 6170 anni fa potrebbe ricadere tra 5 e 3 metri. tale valore è vicino alla profondità di -3 m assegnata alla linea di riva di 6000 anni fa per l’area di vado. in base alla curva eustatica proposta, l’alto stazionamento marino è praticamente cominciato 5-7000 anni fa; in tale periodo le temperature medie annuali avevano probabilmente raggiunto o superato valori simili a quelli attuali (duplessy et alii, 1993; cuffey et alii, 1995; orombelli & ravazzi, 1997; peñalba et alii, fig. 15. curva di variazione locale del livello marino dedotta dalla fig. 14. l’intersezione delle “linee isocrone”, (superfici riflettenti del profilo sismico) datate con il metodo c14 8000, 7000 e 6000 anni fa, con la superficie trasgressiva asw (fig. 13), corrisponde alle “linee di riva” poste a -11, -6,5 e -3 m. l’intersezione della “linea isocrona” datata 5000 anni con la “curva di spostamento” (cslr) della linea di riva dalla posizione -3 m (6000 anni fa) alla posizione attuale, ha fornito il valore di -1,5 m. a questi quattro valori delle linee di riva è stato attribuito un errore (calcolato sperimentalmente) di ±1,5 m circa; esso deriva dall’imprecisione della data e dall’incertezza del reale punto di intersezione delle quattro linee isocrone citate. l’errore dovrebbe comprendere anche l’eventuale spostamento verticale dell’area per motivi tettonici. la ricerca non ha tuttavia evidenziato movimenti apprezzabili né di sollevamento né di subsidenza. holocenic eustatic curve deduced from fig. 14. the intersection among the “isochronous lines”, (reflecting surfaces of the seismic profile) dated by c14 method 8000, 7000 and 6000 yrs bp, and the transgressive surface asw (see fig. 13), corresponds to the “shorelines” at 11, -6,5 and -3 m depth. the intersection between the “isochronous line” dated 5000 yrs bp and with the “shifting curve” (cslr) of the shoreline from the position of -3 m (6000 yrs bp) to the actual position, allowed to obtain the value of 1,5 m depth. to these four values of depth of ancient shorelines was attributed an error (calculated empirically) of about ±1,5 m; it is derived from the inaccuracy of the datings and from the uncertainty of the real point of intersection of the four cited isochronous lines. the error should include also the eventual tectonic uplift of the area. nevertheless, the research evidenced neither tectonic uplifts nor subsidence in the study area. 449le variazioni ambientali ... 1997; williams et alii, 1998; johnsen et alii, 2001). da quel momento cambiano gli effetti erosivi e sedimentari; lungo le coste alte assume importanza l’erosione e l’arretramento delle falesie. lungo le coste basse, invece, si ha un maggior accumulo di sedimenti sottocosta, inizia l’aggradazione delle piane costiere e, successivamente, la progradazione delle spiagge. ciò va tenuto presente negli studi sulla frequentazione preistorica dell’area costiera. ovviamente gli effetti citati dipendono dalle modalità di risalita eustatica; un andamento diverso da quello proposto in fig. 15 potrebbe, ad esempio, aver causato un’ingressione maggiore o minore del mare all’interno della piana (fig. 1), soprattutto nel caso di un alto stazionamento, datato 5-6000 anni fa, prossimo o superiore al livello mare attuale. in questo caso la piana, non ancora colmata da sedimenti, avrebbe potuto costituire un porto naturale per piccole imbarcazioni. linee di riva a quote superiori al livello del mare attuale, datate 5-6000 anni, compaiono in molte curve eustatiche (vedasi rassegna in pirazzoli, 1991, oltre a quella già citata di fairbridge, 1976), ma quasi sempre ciò può essere spiegato come conseguenza di processi tettonici o isostatici; ne consegue che è quasi impossibile risalire alla “vera curva eustatica”. tuttavia le curve ricavate dalle aree in sollevamento mostrano un tipico andamento (esempi in godwin, 1940; porter & stuiver, 1984; belperio et alii, 1989; fletcher iii, 1992, ecc.) che testimonia un netto cambio della velocità di risalita del mare a 5500 – 6000 anni dal presente. questa particolarità è presente anche nella curva ricavata dalle carote di vado (fig. 15), dove il cambiamento avviene tra 5000 e 6000 anni fa. nel mediterraneo (area dell’egeo e del m. caspio) un brusco cambio di velocità avviene a circa 6000 anni, a quote diverse a seconda delle locali condizioni tettoniche (vedasi esempi in pirazzoli, 1991, tavv. 21, 22, 24 e 25). per quanto riguarda l’area di vado, considerazioni morfologiche basate sui terrazzi marini e sull’analisi del fondale esplorato dalle carote, sembrano escludere movimenti tettonici o isostatici di rilievo (v. cap. 2). ciò è in accordo con quanto calcolato da carobene (2004) che (per il settore ligure imperia-genova), ipotizza che nell’olocene via sia stata stabilità o un sollevamento minore di 0,05 mm/a. per comprendere meglio eventuali effetti di movimenti verticali che possano aver condizionato la curva eustatica di vado (fig. 15), è utile il confronto con la curva ricavata da bellotti et alii (1995) nell’area del delta del tevere. gli aa. affermano che la subsidenza “è stata trascurabile” durante gli ultimi 18000 anni. dalla loro curva si ricava che la linea di riva di 6000 anni fa è a circa -6m rispetto al l.m. attuale, mentre quella di 8000 anni fa è a circa 13,5 m; la curva di vado fornisce invece valori, rispettivamente, di -3,5 e di -12 m. per quanto le differenze rientrino nei limiti di errore proposti, tuttavia ciò permette di escludere che l’area indagata di vado sia stata soggetta a subsidenza durante l’olocene. pertanto, “l’andamento” rappresentato in fig. 15 non sembra suscettibile di apprezzabili correzioni; rimane aperta tuttavia la possibilità (sopra esposta) dell’esistenza di oscillazioni a breve periodo del livello marino (sull’ordine di 500 – 1000 anni) che non è stato possibile riconoscere dallo studio delle carote, ma che sono invece state evidenziate in studi di dettaglio basati su indicatori di varia natura (veggiani, 1987; bernier et alii, 1995; kayan, 1991; siddall et alii, 2003; carobene et alii, 2006; milella et alii, 2007), e che potrebbero corrispondere a oscillazioni climatiche. per gli ultimi 2500 anni ortolani & pagliuca (1997) riconoscono cicliche variazioni del clima di durata secolare avvenute nell’area mediterranea; variazioni con periodo di circa 1000 anni avrebbero prodotto, inoltre, spostamenti in latitudine delle fasce climatiche. variazioni climatiche di una certa entità, in particolare quelle evidenziate dalle curve isotopiche dell’ossigeno (orombelli & ravazzi, 1997), dovrebbero sempre corrispondere a oscillazioni del livello marino, in particolare le classiche 5 cronozone a carattere climatico (preboreale, boreale, ecc.) e il “thermal optimum”, evidenziato tra 6000 e 8000 anni fa. alcune oscillazioni potrebbero aver superato l’attuale posizione del livello marino (miyata et alii, 1990; calhoun & fletcher iii, 1996; chen & liu, 1996), ma la loro origine può essere attribuita a effetti idroisostatici previsti dai modelli di deformazione della terra causata dall’ultima glaciazione. kayanne et alii (1993), studiando le isole marianne, ricavano una curva eustatica in cui il livello del mare ha raggiunto l’attuale quota già 4200 anni fa (valore corretto dalla tettonica). anche barra et alii (1997), relativamente alla piana del f. volturno, segnalano che il livello marino di 5000 anni fa era prossimo all’attuale. gli aa. mettono in evidenza che il calcolo dell’effettiva quota dell’antico livello del mare deve tener conto, oltre che della subsidenza dell’area, anche della profondità da attribuire al sedimento datato. i livelli torbosi lagunari, in particolare, indicano il livello del mare con un errore in difetto fino a 2-3 metri. per la laguna di caorle (adriatico settentrionale), galassi & marocco (2000) ricavano una “ipotetica curva di risalita relativa del livello del mare” utilizzando i tassi di sedimentazione lagunare; il risultato è confrontabile con la curva di vado. maggiori problemi presentano le curve ricavate da siti archeologici (antonioli & leoni, 1998); grande analogia con la curva di vado presenta, tuttavia, la curva ricavata da galili et alii, sulla base di dati archeologici, lungo la costa di carmel in israele. il livello a 8000 e quello a 6000 anni b.p. sono a -11,7 e a -3,6 m rispettivamente, contro i -12 e i -3 m di vado. lo studio dettagliato effettuato da morhange et alii (2001) nell’antico porto di marsiglia, ha evidenziato una risalita del livello marino di circa 1,5 m negli ultimi 5000 anni (tasso di risalita = 0,3 mm/a). secondo pirazzoli (2005) questo dato può essere spiegato sia con il modello glacio-isostatico di lambeck & bard (2000), sia con quello idro-isostatico di peltier et alii (in preparazione); secondo l’autore, infatti, negli ultimi 6000 anni vi sarebbe stata una sostanziale stabilità nella risalita eustatica globale. la situazione di vado potrebbe essere analoga a quella di marsiglia. in conclusione, il nuovo metodo utilizzato per ricavare l’innalzamento del livello marino olocenico dallo studio delle carote di vado si è dimostrato valido, avendo fornito un risultato attendibile e confrontabile con altre curve ottenute con sistemi diversi e in aree con caratteristiche geografiche e tettoniche differenti. 450 l. carobene, m. firpo & a. rovere 6. evoluzione degli ambienti sedimentari negli ultimi 8000 anni l’analisi dei sondaggi, l’interpretazione del rilievo sismico e le datazioni c14 hanno permesso di ricavare un soddisfacente modello dell’evoluzione geomorfologica dell’area costiera indagata, in gran parte determinata dalla risalita eustatica olocenica. tale azione è stata accompagnata dalla parallela variazione dei processi esogeni in ambiente subaereo. l’innalzamento del livello marino ha originato erosione (non ben definita come entità) dei preesistenti depositi continentali würmiani e la sovrapposizione su di essi di un corpo sedimentario marino di 10 – 15 metri di spessore. questo è suddivisibile in due parti principali nettamente distinte: una inferiore, legata alla fase principale della trasgressione, quella superiore determinata invece da una prevalente condizione di alto stazionamento. la divisione rispecchia i classici sistemi deposizionali della stratigrafia sequenziale: la sequenza trasgressiva (transgressive system tract) e la sequenza dell’alto stazionamento eustatico (highstand system tract); vedasi, ad esempio, bellotti et alii (1995) e correggiari et alii (1997). la tessitura dei sedimenti osservata nelle carote e la struttura dei corpi dedotta dal profilo sismico hanno permesso, inoltre, di riconoscere due fasi di accrescimento distinte sia nella parte inferiore che in quella superiore, alle quali corrispondono quattro corpi sedimentari diversi per geometria, sedimentologia e significato (fig. 5). a) corpo trasgressivo che, nel tratto considerato dai sondaggi, termina 6000 anni fa (t in fig. 14); esso corrisponde al periodo in cui la linea di riva si sposta verso terra fino a raggiungere il punto di massima ingressione nella piana del t. segno, alla profondità di 3 metri. lo spostamento è più rapido all’inizio di questo periodo, quando la velocità di risalita eustatica è probabilmente superiore a 10 mm/anno tra 10.000 e 8.000 anni fa; la velocità diminuisce progressivamente e diventa di 4,5 mm/a tra 8000 e 6000 anni fa. in corrispondenza, il tasso di sedimentazione è basso inizialmente, ma aumenta poi nel tempo con lo stabilizzarsi della linea di riva (2,5 mm/a in sg5). questo evento determina con molta probabilità la formazione di barre di foce e di un vero e proprio cordone litorale che chiude la piana a monte; questa intercetterà inizialmente gran parte del trasporto solido del t. segno. il corpo trasgressivo è ben riconoscibile dai set in onlap verso terra e da livelli ricchi di fossili; inoltre, il colore del sedimento è prevalentemente grigio-chiaro. depositi sabbiosi e siltoso-ghiaiosi, laminati o gradati, di colore bruno-giallastro (10yr – 5/4 e 2.5y – 6/4) e silt argillosi nerastri ricchi di sostanza organica, ricoperti direttamente dal corpo trasgressivo siltoso sopra descritto, sembrano documentare la presenza di un retrospiaggia nel quale decantavano le torbide portate dal t. segno o si formavano ambienti di tipo lagunare (fig. 5). più in generale, essi sono da considerare lembi relitti di un sistema barriera-retrobarriera, distrutto dalla risalita eustatica. b) la relativa stabilità della linea di riva, pur continuando il livello marino a crescere, anche se lentamente, provoca il progressivo riempimento sedimentario dell’area depressa a monte del cordone litorale sopra citato. durante il lungo periodo del basso eustatico glaciale il torrente segno aveva infatti approfondito il suo alveo e provocato la parziale erosione della piana alluvionale tirreniana (stage 5 della curva isotopica dell’ossigeno). una testimonianza della fase erosiva si ritrova nell’area interessata dai sondaggi (fig. 8), dove mancano completamente i depositi tirreniani marini, che avrebbero dovuto trovarsi interposti (almeno parzialmente) tra il substrato pliocenico e le sovrastanti ruditi würmiane. un forte periodo erosivo, quindi, ha preceduto la deposizione continentale würmiana. a partire da 6000 anni fa, pertanto, i sedimenti più grossolani (sabbie e ghiaie) trasportati dal segno si fermano all’interno della piana (più bassa rispetto all’attuale di 5-6 m), mentre all’esterno, ovvero a mare, arrivano solamente peliti. si può anche ipotizzare un cambiamento di granulometria del materiale detritico proveniente dai versanti; il periodo caldo, cominciato già 8000 anni fa (cuffey et alii, 1995; peñalba et alii, 1997; ecc.), ha sicuramente dato inizio ad un veloce e generalizzato incremento della vegetazione sui versanti e, come conseguenza, ha ridotto progressivamente l’erosione ed il trasporto di detrito grossolano. si origina in tal modo un deposito marino compreso tra le superfici 3 e 4 (mi in fig. 14), costituito prevalentemente da silt argillosi e argille pelitiche scure a stratificazione parallela, in un intervallo di tempo di circa 1000 anni (da 6000 a 5000 anni fa circa) (fig. 11); detto corpo, caratterizzato da bassa velocità di sedimentazione, sovrasta il precedente trasgressivo, con uno spessore che (nell’area dei sondaggi) varia da un massimo di 2,30 m (verso terra) ad un minimo di 1,20 m (verso mare). c) a partire da 5000 anni fa circa la linea di riva comincia a progradare, assecondando anche l’innalzamento finale del livello marino che va verso le condizioni del massimo eustatico interglaciale odierno. il sovralluvionamento della piana interna al cordone litorale innalza continuamente il fondovalle, e il torrente segno raggiunge la foce scaricando in mare il carico solido trasportato in sospensione. il corpo sedimentario che si forma a mare va a sovrapporsi al precedente descritto in b, determinando un netto stacco sedimentologico (p in fig. 14). il passaggio è evidenziato da silt sabbiosi e da sabbie più o meno siltose, a volte contenenti ghiaietto (sg3), di colore grigio (spesso chiaro), con tritume organogeno e fossili (fig. 5); sul fondale si instaurano praterie di posidonia. lo spessore è massimo verso riva (4,5 m), mentre diminuisce verso il largo; gli orizzonti sul profilo sismico testimoniano che la struttura del corpo sedimentario è data da set che si sovrappongono verso mare in downlap sul corpo sedimentario precedente. le date c14 (cap. 4) hanno permesso di inquadrare cronologicamente la sequenza progradante tra 5000 e 1800 anni fa circa. durante questo periodo la linea di riva si sposta verso mare di 600-700 m (fig. 14). d) la linea di riva, la foce del t. segno ed il livello del mare tendono a stabilizzarsi nella posizione attuale. la piana diventa nel tempo sempre più stabile anche perchè il torrente, nella fase finale di questo periodo, incide le sue alluvioni terrazzandole. questi eventi fanno 451le variazioni ambientali ... sì che l’intero carico in sospensione portato dal t. segno si scarichi in mare, dando origine ad un consistente conoide sommerso che risulta quasi interamente costituito da silt, a volte sabbioso, a volte argilloso, scuro o nerastro; la percentuale di sabbia aumenta verso riva (fig. 5). il corpo d presenta spessori minori verso riva e maggiori verso mare; in corrispondenza del sondaggio sg1 lo spessore del corpo del conoide raggiunge gli 8 metri (tasso di sedimentazione di 5,3 mm/a), mentre è di soli 2 m in sg6. la stratificazione, marcata dagli orizzonti sul profilo sismico, vede gli strati divergere verso mare. la suddivisione della sedimentazione nei 4 periodi principali, schematicamente sopra descritti, corrisponde alle divisioni presenti nelle figg. 11 e 14. questa è una semplificazione che non tiene conto delle variazioni climatiche di durata secolare che si sono succedute nel tempo e documentate con altri metodi (carote di ghiaccio, pollini, dati storici). anche l’intervento dell’uomo (come documentato in molti lavori), soprattutto con le pratiche agricole e con il disboscamento, può aver modificato l’erosione del suolo e quindi la sedimentazione. le variazioni sedimentologiche presenti nelle carote di vado, e visibili in parte nella fig. 5 all’interno delle 4 sequenze principali, potrebbero esserne una testimonianza. 7. le variazioni del paesaggio i sondaggi effettuati nella rada di vado ligure permettono di ricostruire la storia evolutiva dell’area a partire da almeno 9000 anni fa. estrapolando la curva eustatica di fig. 15, si ricava, infatti, che in quella data il livello marino era più basso di una ventina di metri rispetto ad oggi; questa profondità ricade ampiamente all’interno dell’area indagata (fig. 12). la corrispondente linea di riva era con molta probabilità ubicata a mare rispetto a quella attuale di circa 250 metri ma, essendo più bassa, essa è oggi sovrastata da 14-15 m di sedimenti marini depostisi a seguito dell’innalzamento eustatico. lo sconvolgimento del paesaggio è stato quindi enorme; la ricerca effettuata ha permesso di stabilire: 1) la trasgressione marina ha invaso l’attuale piana alluvionale del t. segno raggiungendo il punto più interno 6000 anni fa, a circa 700-800 m dall’attuale linea di riva (fig. 1). 2) tale linea di riva era più bassa di circa 8 m rispetto all’attuale fondovalle che divenne, da quel momento, continuamente soggetto ad alluvioni e quindi ad accrescimento. l’uomo neolitico dovette quindi cercare siti stabili nelle zone più alte della piana, o sui versanti o sulle superfici terrazzate (fluviali o marine) esistenti. 3) tra il 3000 a.c. ed il 200 d.c. circa la linea di riva subì una progradazione che la portò progressivamente verso l’attuale posizione. contemporaneamente la piana era soggetta a sovralluvionamento, mentre depositi colluviali, detriti di piede di versante e conoidi si accumulavano ai suoi bordi. le condizioni di abitabilità della piana continuavano pertanto ad essere difficili. la superficie “romana” di 2000 anni fa si trova oggi, con molta probabilità, 3-4 metri più in basso dell’attuale piano campagna (fondovalle). 4) negli ultimi 1800 anni è diventato secondario il ruolo dell’eustatismo e dei cambiamenti climatici, mentre è diventato progressivamente importante l’intervento dell’uomo sul territorio. il corpo deposizionale formatosi a mare in questo periodo, che in prossimità del sondaggio sg1 raggiunge lo spessore di 7 m (fig. 11), è composto essenzialmente da peliti nere, ricche di sostanza organica; esso è la testimonianza di un forte dilavamento dei versanti, probabilmente disboscati dall’uomo, e di erosione dei suoli. 5) in base ai punti sopra esposti appare improbabile la presenza (e quindi il ritrovamento) di siti archeologici fissi nell’area della piana corrispondente alle alluvioni formatesi durante la risalita eustatica degli ultimi 8000 anni. numerosi reperti archeologici, invece, sono stati ritrovati nell’attuale abitato di vado; essi testimoniano l’antica vada sabatia, in particolare gli scavi condotti nell’area antistante la chiesa di san giovanni battista e sotto il palazzo comunale (bulgarelli, 2007). detta area si trova a quote variabili tra 8 e 9 metri s.l.m. attuale; pertanto si può ipotizzare che venisse sfruttata la superficie terrazzata tirreniana (pat in fig. 1), al riparo dalle alluvioni che invece interessavano il fondovalle esteso immediatamente a sud. i relitti di questa superficie sono più alti dell’attuale piana in quanto il livello marino, durante il picco eustatico interglaciale corrispondente al mis 5.5, era più alto (a livello globale) di circa 5 m rispetto all’odierno livello. la superficie tirreniana è stata successivamente ricoperta da depositi continentali würmiani e olocenici. 6) già nel iii sec. a.c., inoltre, era attivo il portus vadorum sabatium (ricordato da plinio), “favorito dai fondali profondi dell’ampio bacino riparato dai venti” (bulgarelli, 2007). a quel tempo, infatti, non si era ancora deposta la sequenza ase (relativa all’alto stazionamento eustatico – fig. 14) e i fondali erano più profondi (rispetto ad oggi) da 3 m (presso riva) a 7 m (500 metri più al largo). 7) il ritrovamento di reperti archeologici (essenzialmente frammenti di laterizio o di terracotta) a mare, immersi nel sedimento per 1-2 m, permette di escludere che essi siano riferibili a siti archeologici di età romana. infatti la superficie 5 datata 1800 anni si trova, presso riva, 3-4 m più bassa del top del sedimento (fondale attuale), e tale valore aumenta man mano che ci si allontana da riva (fig. 14). tenendo conto che la presenza dei frammenti di laterizi è concentrata nelle aree di foce, è possibile affermare che essi costituiscano elementi erosi e trasportati in mare dai corsi d’acqua sfocianti nella rada di vado. conclusioni lo studio di alcuni profili sismici, di 13 sondaggi effettuati nel golfo di vado ligure (fig. 3), delle caratteristiche morfologiche e geologiche dell’area emersa (fig. 1) e marina (fig. 2), ha permesso di arrivare ad alcune considerazioni sui seguenti punti: 452 l. carobene, m. firpo & a. rovere terrazzi e tettonica. sono stati riconosciuti 5 ordini di terrazzi marini ritenuti quaternari: 165÷185 m; 130÷145 m; 115÷130 m; 55÷70 m e 35÷45 metri s.l.m.; ciò ha permesso di dedurre che la velocità di sollevamento dell’area durante il quaternario è stata bassa (ordine di grandezza: 0,10 – 0,15 mm/a) e che è calata nel tempo. si è tenuto conto che nella grotta di bergeggi (pochi chilometri a sud – vedi fig. 2) il livello tirreniano (mis 5.5) è stato misurato a 5,20 metri (carobene & firpo, ricerca in corso). ciò documenterebbe un sollevamento tettonico massimo di 0,04 mm/a, ponendo l’originale paleolivello alla stessa quota del livello attuale. tuttavia, in base ai dati isotopici dell’ossigeno contenuto nel guscio dei foraminiferi planctonici e bentonici, si ritiene che il massimo livello di stazionamento durante il mis 5.5 sia stato di alcuni metri più alto che oggi (shackleton, 1987). sistemi di faglie quaternarie (sistemi a: 60-65°; 120-130°; 145-150°) hanno condizionato la morfologia emersa e sottomarina, in particolare la direzione dei crinali, delle aste fluviali e del canyon di vado (fig. 2). la trasgressione olocenica i sondaggi, di cui 10 effettuati a mare, hanno consentito di riconoscere il substrato, costituito da argille marnose del pliocene inferiore, i depositi continentali riferibili al periodo di basso eustatico (würm) ed il corpo sedimentario marino della trasgressione olocenica (fig. 8). un dato interessante è costituito dall’assenza dei depositi marini della trasgressione tirreniana. 25 datazioni c14 hanno fornito età calibrate comprese tra 8225 e 510 anni b.p. (tab. 2); le date sono state utilizzate per effettuare la cronostratigrafia del deposito marino olocenico (fig. 12). la correlazione dei risultati ricavati dall’analisi del profilo sismico (fig. 4), dallo studio sedimentologico delle carote (fig. 5) e dalla datazioni c14 ha consentito di riconoscere una fase trasgressiva, terminata 6000 anni fa; un periodo di relativa stabilità della linea di riva (da 6000 a 5000 anni b.p.); un successivo periodo di progradazione (da 5000 a 1800 anni b.p.) e, infine, il periodo dell’alto eustatico interglaciale che arriva ai nostri giorni (fig. 11). complessivamente il corpo sedimentario marino olocenico raggiunge uno spessore di 14 metri circa. la sequenza trasgressiva si caratterizza per prevalenti silt e silt sabbiosi di color grigio e grigio-chiaro, a volte fossiliferi. la sequenza derivata dal successivo stazionamento è invece costituita da silt e silt argillosi nerastri, contenenti a volte tritume organogeno e posidonia. la sequenza progradante mostra una prevalenza di silt (grigio chiaro in basso e grigio scuro in alto, dove si presenta argilloso); presenti livelli sabbiosi e livelli gradati. la sequenza relativa all’alto stazionamento finale è costituita in prevalenza da silt argillosi e da argille siltose nerastre, a volte con posidonia (fig. 5). le varie tappe della risalita eustatica sono state ricostruite lungo un profilo geologico (a-b in fig. 1) che prosegue verso terra il profilo sismico documentato dall’allineamento di 9 sondaggi (fig. 3). su questo profilo è stato applicato un metodo di estrapolazione dei dati precisi presenti in fig. 12; esso è consistito nell’estendere verso terra le superfici datate 8000 – 7000 – 6000 anni fino ad intersecarle con la superficie trasgressiva che, estrapolata verso monte, determina l’andamento della “superficie würmiana” (asw in fig. 13). la superficie che è alla base del corpo progradante (datata 5000 anni) è stata invece interpolata con l’andamento del fondovalle di uguale età (linea sip – fig. 13). la superficie di 6000 anni fa interseca la asw alla profondità di -6,5 m nel punto considerato di massima ingressione (rmi in fig. 14). da questo punto inizia la progradazione della spiaggia (o barriera) verso mare, fino all’attuale posizione. la curva dell’innalzamento del livello marino il procedimento (descritto in dettaglio nel cap. 5) ha portato a riconoscere le linee di riva di 8000 anni fa (-12 m), di 7000 anni fa (-6,5 m), di 6000 anni fa (-3 m) e di 5000 anni fa (-1,5 m) (fig. 14). sulla base di questi dati è stata costruita la curva (fig. 15) che rappresenta l’andamento della risalita eustatica in un’area che, in base a dati geologici, morfologici e a confronti con altre aree costiere, non mostra indizi di abbassamento. mancano prove anche di un eventuale sollevamento tettonico che, in ogni caso, sarebbe di lievissima entità come documentato nella grotta di bergeggi (vedi sopra). la presenza di movimenti verticali di origine isostatica non sono dimostrabili, anche perché l’innalzamento del livello marino di 3 m avvenuto negli ultimi 6000 anni è da alcuni autori ritenuto glacioeustatico, da altri idro-isostatico. ciò complica la comprensione della reale entità della risalita eustatica, spesso complicata da interferenze tettoniche locali. la trasformazione del paesaggio e gli antichi popolamenti le conseguenze della risalita eustatica hanno permesso di riconoscere le grandi modificazioni del paesaggio degli ultimi 8-9000 anni; il periodo coincide con l’inizio e lo sviluppo del neolitico. circa 9000 anni fa si estendeva verso mare, per almeno un chilometro, una superficie emersa e poco inclinata (1°), relitto dell’ampia pianura würmiana; tenendo conto del miglioramento climatico in atto, questa piana poteva essere utilizzata per le coltivazioni. nell’arco di 3000 anni la piana viene però ricoperta dall’avanzata del mare, mentre il fondovalle del t. segno diventa inospitale, in quanto comincia ad essere interessato da continue inondazioni. dopo un periodo di relativa stabilità della linea di riva, durato fino al 5000 b.p., il continuo accumulo di detriti lungo costa provoca la progradazione della spiaggia emersa e sottomarina e la contemporanea aggradazione della piana alluvionale del t. segno. ciò spinge gli antichi abitanti ad abitare e a costruire soprattutto sui versanti, utilizzando di preferenza le superfici terrazzate. in base a quanto detto, resti di siti di età più recente di 6000 anni si possono o si potrebbero trovare lungo il fondovalle del t. segno solamente a monte della linea di riva di massima ingressione (fig. 1). se esistono, essi sono ricoperti da depositi di retrospiaggia, alluvionali o di conoide, spessi fino a 7-8 metri. testimonianze dell’antica città romana di vada sabatia sono invece presenti (fig. 1) su un relitto di piana alluvionale tirreniana a 7-8 m di altitudine (pat in fig. 1), oltre a reperti del bronzo medio e recente. una grande quantità di ceramica usata come discarica 453le variazioni ambientali ... (“cocciopesto”) documenta, inoltre, la tarda età del ferro. i l “castellaro” ubicato sul vicino monte sant’elena (347 m, tra vado e bergeggi) ha fornito testimonianze di frequentazione tra il vi e il i sec. a.c. (del lucchese et alii, 1994). resti di edifici funerari di età imperiale erano distribuiti lungo la strada che portava al valico di san genesio (spartiacque meridionale, tra m. s. elena e m. mao). infine, sepolture datate tra il i e il iii sec. d.c. sono state individuate in un’area a sud del t. segno (fig. 1, quota 12,5 m) (dati ricavati da bulgarelli, 2007). a partire da 1800 anni fino ad oggi, la linea di costa si sposta verso mare lentamente, fino a diventare relativamente stabile; nell’antistante area marina si deposita rapidamente la sequenza sedimentaria relativa al picco eustatico interglaciale (ase in fig. 14). dal punto di vista climatico quest’ultimo periodo non è stato però omogeneo, come mostrano anche le curve paleoclimatiche ricavate da carote di ghiaccio e i numerosi lavori esistenti. da 1800 a 1600 anni fa terminava un periodo di ottimo climatico, al quale seguì (fino al 750 d.c.) un deciso peggioramento, con diminuzione delle temperature e aumento della piovosità. dal 750 al 1150 d.c. si sviluppa l’ottimo climatico medioevale; dopo un periodo di variabilità, un nuovo peggioramento origina la piccola età glaciale, dal 1500 circa al 1850 d. c. queste fasi hanno sicuramente determinato variazioni nell’erosione dei versanti e nella sedimentazione a mare. nelle carote (fig. 5) sono osservabili passaggi da argille siltose, a silt, a silt sabbiosi e a sabbie siltose. non si può escludere, tuttavia, che alcuni cambiamenti nella sedimentazione marina abbiano origine antropica. la progressiva stabilizzazione della piana alluvionale negli ultimi 1800 anni la rese abitabile o utilizzabile per le coltivazioni, anche se non in maniera continuativa, ma la diminuzione dello spazio e l’aumento probabile della popolazione e lo sviluppo dei consumi portarono però all’uso della deforestazione; ciò ha probabilmente innescato il dilavamento dei versanti e l’erosione dei suoli. questa pratica potrebbe spiegare la prevalenza di silt argillosi neri nella parte finale delle carote studiate a vado. ringraziamenti lavoro eseguito con i fondi del progetto prin 2005, unità di genova: “variazioni ambientali e comunità umane durante la trasgressione olocenica in liguria” (nell’ambito del programma nazionale “crisi climatico-ambientali, catastrofi e comunità umane nell’arco dell’olocene: un approccio geoarcheologico”). si ringrazia, inoltre, l’autorità portuale di savona per aver finanziato lo studio “geoarcheologia della foce del torrente segno e della piattaforma continentale interna” e la soprintendenza archeologica della liguria per l’aiuto fornito. un doveroso ringraziamento ai revisori piero bellotti e paolo pirazzoli. lavori citati amorosi a., colalongo m.l., pasini g. & preti d. (1999) sedimentary response to late quaternary sealevel changes in the romagna coastal plain (northern italy) sedimentology, 46, pp. 99-121. antonioli f. & leoni g. (1998) siti archeologici sommersi e loro utilizzazione quali indicatori per lo studio delle variazioni recenti del livello del mare il quaternario, 11 (1), pp. 53-66. bard e., hamelin b., arnold m., montaggioni l., cabioch g., faure g. & rougerie f. (1996) deglacial sea-level record from tahiti corals and the timing of global meltwater discharge nature, 382, pp. 241-244. barra d., romano p., santo a., campajola l., roca v. & tuniz r. (1997) the versilian transgression in the volturno plain (campania southern italy): paleoenvironmental history and chronological data il quaternario, 9 (2) (1996), pp. 445-458. bellotti p., milli s., tortora p. & valeri p. (1995) physical stratigraphy and sedimentology of the late pleistocene-holocene tiber delta depositional sequence sedimentology, 42 (4), pp. 617–634. belperio a.p. 1989 the green house debate and rising sea level search, 20 (2), pp.48-50. bernier p., dalongeville r., dupuis b. & de medwecki v. (1995) holocene shoreline variations in the persian gulf: example of the umm al-qowayn lagoon (uae) quaternary international, 29-30, pp. 95-103. bird e. (2000) coastal geomorphology england, wiley & sons, 322 pp. boni a. (1984) il pliocene al margine delle alpi liguri mem. soc. geol. it., 28, pp 114-125. boni a., cerro a., gianotti r. & vanossi m. (1971) note illustrative della carta geologica d’italia. fogli 92-93 “albenga-savona” roma, serv. geol. it., 50 pp. bulgarelli f. (2007) vado ligure vada sabatia in: ancora sui liguri un antico popolo europeo tra alpi e mediterraneo, a cura di r.c. de marinis e g. spadea, pp. 183-187, de ferrari editore, genova. calhoun r.s. & fletcher iii c.h. (1996) late holocene coastal plain stratigraphy and sea-level history at hanalei, kauai, hawaiian islands quaternary research, 45, pp. 47-58. carobene l. (2004) uplifted coastlines and marine terraces. in: geology of italy (special volume florence 2004) soc. geol. it., pp. 174-177. carobene l. & cevasco a. (2007) una deformazione gravitativa profonda di versante all’origine del piano di oneto, val graveglia (appennino ligure) il quaternario, 20 (1), pp. 45-56. carobene l. & firpo m. (2002) forme terrazzate relitte di genesi marina lungo la costa ligure tra genova e savona (liguria occidentale) il quaternario, 15, pp. 53-68. carobene l., firpo m. & melli p. (2006) aspetti geoarcheologici nel porto antico di genova. in: “archeologie studi in onore di tiziano mannoni”, pp. 295-299. bari, edipuglia. chen y.g. & liu t.k. (1996) sea-level changes in the last several thousand years, penghu islands, taiwan strait quaternary research, 45, pp. 254262. cnr (1987) neotectonic map of italy quaderni della 454 l. carobene, m. firpo & a. rovere ricerca scientifica, 4 (114), foglio 1. corradi n., fanucci f., fierro g., firpo m., piccazzo m., & mirabile l. (1984) la piattaforma continentale ligure: caratteri, struttura ed evoluzione rapporto tecnico finale del prog. final. “oceanografia e fondi marini”, c.n.r., roma. correggiari a., roveri m. & trincardi f. (1996) late pleistocene and holocene evolution of the north adriatic sea il quaternario, 9 (2), pp. 697-704. cuffey k.m., clow g.d., alley r.b., stuiver m., waddington e.d. & saltus r.d. (1995) large arctic temperature change at the wisconsin-holocene glacial transition science, 270, pp. 455 – 458. del lucchese a., davite c., ridella r. & torre e. (1994) il castellaro di bergeggi: campagne di scavo 1982-1985 rivista ingauna e intemelia, xlvixlvii (1-4), pp.52-62 delmonte b., petit j.r. & maggi v. (2002) glacial to holocene implications of the new 27,000-year dust record from the epica dome c (east antarctica) ice core clim. dyn., 18 (8), pp. 647660. duplessy j.c., bard e., labeyrie l., duprat j. & moyes j. (1993) oxygen isotope records and salinity changes in the northeastern atlantic ocean during the last 18,000 years paleoceanography, 8, pp. 341-350. fairbridge r.w. (1961) eustatic change in sea level phys. chem. earth, 4, pp. 99-185. fairbridge r.w. (1976) effects of holocene climatic change on some tropical geomorphic processes quaternary research, 6 (4), pp. 529-556. fanucci f. (1979) neotettonica dei margini continentali del mar ligure mem. soc. geol. it., 19 (1978), pp. 535-542. fanucci f. (1978) il plioquaternario della piattaforma continentale ligure tra genova e savona atti associazione italiana oceanologia e limnologia, 2, pp. 81-87. fanucci f., ferretti o., firpo m., piccazzo m. & davide s. (1996) morfologia e struttura della piattaforma continentale tra vado ligure e savona e suoi rapporti con la fascia litorale atti dell’ 11° congresso della associazione italiana di oceanologia e limnologia (1994), g. albertelli, a. de maio & m. piccazzo (eds), pp. 667-677. fanucci f., firpo m., piccazzo m. & mirabile l. (1984) le plio-quaternaire de la mer ligure: epaisseurs et conditions d’accumulation marine geology, 55, pp. 291-303. fanucci f., gianmarino s. & tedeschi d. (1980) il pliocene della costa e del margine continentale dell’appennino ligure in rapporto alla neotettonica mem. soc. geol. it., 21, pp. 259-265. fletcher iii c.h. (1992) sea level trends and physical consequences: applications to the u.s. shore earth-science reviews, 33, pp.73-109 galassi p. & marocco r. (2000) relative sea level rise, sediment accumulation and subsidence in the caorle lagoon (northern adriatic sea, italy) during holocene il quaternario, 12 (2), pp. 249-256. galili e., weinstein-evron m. & ronen a. (1988) holocene sea-level changes based on submerged archaeological sites off the northern carmel coast in israel quaternary researc, 29, pp. 36-42. godwin h. (1940) studies in the post glacial history of british vegetation. iv. post-glacial changes of relative landand sea-level in the english fenland phyl. trans. r. soc. lond., 230 (b), pp. 239-303. hillaire marcel c. (1978) isostasy and eustasy of hudson bay geology, 6, pp. 117-122. jelgersma s. (1979) sea-level changes in the north sea basin in: e. oele, r.t.e. schuttenhelm & a.j. wiggers (eds) the quaternary history of the north sea, acta universitatis upsaliensis: symposium universitatis upsaliensis annum quingentesimum celebrantis, 2, pp. 233-248. johnsen s.j., dahl-jensen d., gundestrup n., steffensen j.p., clausen h.b., miller h., masson-delmotte v., sveinbjornsdottir a.e. & white j. (2001) oxygen isotope and palaeotemperature records from six greenland ice-core stations: camp century, dye-3, grip, gisp2, renland and northgrip journal of quaternary science, 16, pp. 299–307. kayan i. (1991) holocene geomorphic evolution of the besik plain and changing environment of ancient man studia troica, 1, pp. 79-92. kayanne h., ishii t., matsumoto e. & yonekura a. (1993) late holocene sea-level change on rota and guam, mariana islands, and its constraint on geophysical predictions quaternary research, 40, pp. 189-200. l’homer a., bazille, f., thommeret, j. & thommeret y. (1981) principales ètapes de l’edification du delta du rhone de 7000 bp à nos jours; variations du niveau marin oceanis, 7 (4), pp. 389-408. lambeck k. & bard e. (2000) sea level change along the french mediterranean coast since the time of the last glacial maximum earth and planetary science letters, 175, pp. 203-222. lambeck k., antonioli f., purcell a. & silenzi s. (2004) sea-level change along the italian coast for the past 10,000 years quaternary science reviews, 23, pp. 1567-1598. louwe kooijmans l.p. (1971) mesolithic bone and antler implements from the north sea and from the netherlands berichten van de rijksdienst voor oudheidkundig bodemonderzoek, 20 21, pp. 27-73. milella m., pignatelli c., donnaloia m., mastronuzzi g. (2007) sea level during 4th 2nd century b.p. in egnazia (italy) from archaeologica and hydrogeological data il quaternario, 19 (2) (2006), pp. 251258. miyata t., maeda y., matsumoto e., matsushima y., rodda p., sugimura a. & kayanne h., (1990) evidence for a holocene high sea-level stand, vanua levu, fiji quaternary research, 33, pp. 352-359. morhange c., laborel j. & hesnard a. (2001) changes of relative sea level during the past 5000 years in the ancient harbour of marseilles, southern france palaeogeogr. palaeoclimatol. palaeoecol., 166, pp. 319-329. orombelli g. & ravazzi c. (1997) the late glacial and early holocene: chronology and paleoclimate il quaternario, 9 (2) (1996), pp. 439-444. ortolani f. & pagliuca s. (1997) variazioni climaticoambientali nell’area mediterranea durante il periodo storico: evidenze geoarcheologiche di cicliche 455le variazioni ambientali ... crisi ambientali tipo “effetto serra” il quaternario, 9 (1) (1996), pp. 209-212. peñalba m.c., arnold m., guiot j., duplessy j.c. & de beaulieu l. j. (1997) termination of the last glaciation in the iberian peninsula inferred from the pollen sequence of quintanar de la sierra quaternary research, 48, pp. 205–214. pieri m. & groppi g. (1981) subsurface geological structure of the po plain, italy progetto finalizzato geodinamica 414, c.n.r, 13 pp. pirazzoli p.a. (1991) world atlas of holocene sea level changes amsterdam, elsevier oceanography series, amsterdam, 58 pp. pirazzoli p.a. (2005) a review of possible eustatic, isostatic and tectonic contributions in eight lateholocene relative sea-level histories from the mediterranean area quaternary science reviews, 24, pp. 1989-2001. porter s.c., stuiver m. & heusser c.j. (1984) holocene sea-level changes along the strait of magellan and beagle channel, southernmost south america quaternary research, 22 (1), pp. 59-67. preti m. (1999) the holocene transgression and the land–sea interaction south of the po delta giorn. di geologia, 61, pp. 143-159. preti m. (2000) eustatismo, subsidenza e linee di intervento per la difesa del territorio costiero in emiliaromagna mare e cambiamenti globali, pp. 167–179. bologna, icram. selli r. & ciabatti m., (1977) l’abbassamento del suolo della zona litoranea ravennate giorn. geologia, 42 (1), pp. 1-47. schackleton n. j (1987) oxygen isotopes, ice volume and sea level. quaternary science reviews, 6 (3/4), pp. 183-190. shepard f.p. (1963) thirty-five thousand years of sea level. in: clemmens t. (ed) essays in marine geology in honor of k.o. emery, university of southern california press, los angeles, pp. 1-10 siddal m., rohling e.j., almogi-labin a., hemleben c., meischner d., schmelzer i. & smeed d.a. (2003) sea level fluctuations during the last glacial cycle nature, 423, pp. 853-858. veggiani a. (1987) il territorio di s. giorgio di cesena: vicende geologiche, origini del popolamento e trasformazioni ambientali in: san giorgio tra cronaca e storia, cassa rurale ed artigiana a cura di c. riva, pp. 7-36. williams m., dunkerley d., de deckker p. kershaw, p. & chappell, j. (1998) quaternary environments (chapter 6) london, arnold, 329 pp. ms. ricevuto l’8 luglio 2008 testo definitivo ricevuto il 7 ottobre 2008 ms. received: july 8, 2008 final text received: october 7, 2008 456 l. carobene, m. firpo & a. rovere available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 5 9 a geodatabase of late pleistocene holocene palaeo sea-level markers in the gulf of naples vincenzo amato 1 , pietro p.c. aucelli 2 , gaia mattei 2 , micla pennetta 3 , angela rizzo 2 , carmen m. rosskopf 1 , marcello schiattarella 4 1 geogislab, dipartimento bioscienze e territorio, università degli studi del molise, isernia, italy 2 dipartimento di scienze e tecnologie (dist), università degli studi di napoli parthenope, napoli, italy 3 dipartimento di scienze della terra, dell'ambiente e delle risorse (distar) università degli studi di napoli federico ii, napoli, italy 4 dipartimento delle culture europee e del mediterraneo (dicem), università degli studi della basilicata, matera, italy corresponding author: m. pennetta <pennetta@unina.it> abstract: during the late pleistocene and holocene periods, the italian coasts have undergone a very articulated geological and geomorphological evolution, due to the complex and differentiated interaction of endogenous and exogenous dynamics. aim of this study is to implement a geodatabase concerning the geomorphological, stratigraphic, biological and archaeological palaeo sea-level proxies located in the gulf of naples, in order to provide a catalogue of the most representative markers and an overall picture of ancient shorelines positions since the late pleistocene. keywords: relative sea level changes, palaeo sea-level markers, gulf of naples, southern italy 1. introduction the sea level variations that have occurred during the late-pleistocene and the holocene along the italian coasts obviously have deeply controlled coastal dynamics and morphology, causing cliff erosion, barrier beach and lagoon system migration, marine ingression, etc. in order to determinate past sea-levels, the identification of a number of sea-level indicators is required. archaeological proxies are largely used for the holocene, especially for the historical period (auriemma & solinas, 2009; morhange & marriner, 2015; pennetta et al., 2016; vacchi et al., 2016), while depositional and erosional proxies, such as speleothems, beach and lagoonal/marshy sediments, notches, abrasion platforms and marine terraces, along with associated biological indicators such as lithophaga perforations are in general useful proxies for ancient pleistocene shorelines (benjamin et al., 2017). in this study, we present preliminary results of a wider research project aimed to inventory the palaeosea level markers along campania (southern italy) coasts. in detail, a geodatabase of the geomorphological, sedimentary, biological and archaeological palaeo sea-level proxies recorded in the gulf of naples (campania region, southern italy) has been implemented by collecting via literature and proper studies the main palaeo sea-level markers. the main aim of this study is to provide a free application of the collected proxies by releasing a google xml file available for different stakeholders interested in the management, scientific data analysis and/or preservation of the proxies. 2. materials and methods the geodatabase has been implemented in a gis environment by compiling two main attribute tables connected by a joint tool. the first table identifies the sites and the position where the palaeo sea-level proxies are located, specifying an id number and the geographic coordinates. in the second table, the proxies are classified as archaeological, biological, depositional and erosional, and the height of each proxy, below or above the present sea-level, is indicated. the geodatabase furthermore provides information about the state of conservation and site conditions of the proxies, and its illustration by a representative photo. 3. results the gulf of naples coastline is characterised by different coastal types, including high rocky, low sandy and volcanic coasts. the locations of detected palaeosea level proxies are indicated in figure 1. each proxy is indicated by a number and an asterisk. the colour of the asterisk identifies the proxy type, the colour of the square that surrounds the asterisk, instead, the period: late pleistocene (green square) and holocene (yellow square). table 1 summarizes the data of collected proxies: id number, proxy type, proxy age, and the ancient sea level height evaluated for each marker. furthermore, for proxies reported by previous studies references are added. the proxies referring to the holocene period are mainly represented by coastal archaeological ruins, while tidal notches are the main markers of late pleistocene sea level positions. https://doi.org/10.26382/aiqua.2018.aiquaconference 4. discussion and conclusion the comparative analysis of the main palaeo-sea level proxies has resulted in a homogeneous framework of the gulf of naples coasts, for a time lapse ranging from the late pleistocene to the present-day. at this time, the database contains only the markers referred to highstand phases, even if it is not excluded in the future to implement the database also with lowstand markers that, in the gulf, are almost always below the present sea level. totally, the database contains 47 sea level proxies, of which 7 related to the pleistocene and 40 related to the holocene. the analysis of the late pleistocene-holocene sea level markers included in the geodatabase has given evidence on the stability or non-stability of the investigated coastal sectors and, thus, on the entity of local vertical ground movements. these local movements are particularly significant in this sector, as it is located in a region of the italian tyrrhenian side where the volcanotectonics significantly influenced the local sea level variations since the late pleistocene. the late pleistocene proxies recognizable along the coasts of naples gulf are exclusively positioned in the eastern sector. the erosional proxies located along the sorrento peninsula and capri coasts testifies a tectonic stability, though ferranti & antonioli (2007) use a change in elevation of the tidal notch to evaluate a minor tectonic slips along the capri main faults. on the contrary, the depositional proxy located in the sarno plain is a witness of a subsiding trend, that has characterised this sector since the last interglacial. considering the holocene sea level markers, it is 6 fig. 1 location and type of main collected palaeo sea level proxies in the gulf of naples. ->>> tab. 1 table of main collected palaeo sea-level proxies in the gulf of naples containing: progressive id; position of each site; typology and specific type of proxy; age in years before present; h, height above/below the present sea level; references. amato v. et al. 7 palaeo sea-level markers in the gulf of naples possible to state that along the high rocky coasts of sorrento peninsula and posillipo (naples) the late holocene sea level rise led to the submersion of archaeological sites located at the base of the active sea cliffs. anyway, in sorrento peninsula the submersion has to be ascribed to eustatic effect, in naples the eustatic effect is coupled with local subsidence of volcanotectonic origin (aucelli et al., 2017a; b). in the sorrento peninsula, the deposition of volcaniclastic products of the 79 ad vesuvius eruption enhanced local and short-term shoreline progradation. along the sandy low coasts (sarno), although slightly subsiding or stable, the increase of fluvial inputs, due to late holocene climatic oscillations and land use changes, caused the progradation of the shorelines and the aggradation of the ground level, while the progradation of the barrier-lagoonal system was favoured by the 79ad vesuvius volcaniclastic deposits. in the cases of the volcanic coasts (from pozzuoli bay to naples), the vertical ground movements due to volcano-tectonic factors are the main responsible for their submersion. in the pozzuoli sector, archaeological sites were affected by short-term uplift. finally, in the case of naples, strongly anthropised since greek-roman times, coastal progradation was enhanced by several coastline modifications due to human coastal reclamation. in conclusion, the database here implemented represents a useful tool to manage geospatial coastal geomorphological, archeological, biological and stratigraphical data, providing useful information for the scientific investigation of ancient regional sea levels, and possible interventions aimed at their preservation. references aucelli p.c., cinque a., giordano f., mattei g. (2016a) a geoarchaeological survey of the marine extension of the roman archaeological site villa del pezzolo, vico equense, on the sorrento peninsula, italy. geoarchaeology, 31 (3), 244-252. aucelli p.c., cinque a., mattei g., pappone g. (2016b) historical sea level changes and effects on the coasts of sorrento peninsula (gulf of naples): new constrains from recent geoarchaeological investigations. palaeogeography, palaeoclimatology, palaeoecology, 463, 112-125. aucelli p.c., cinque a., mattei g., pappone g., rizzo a. (2017a) studying relative sea level change and correlative adaptation of coastal structures on submerged roman time ruins nearby naples (southern italy). quaternary international. doi: 10.1016/j.quaint.2017.10.011 aucelli p.c., cinque a., mattei g., pappone g., stefanile m. (2017b) coastal landscape evolution of naples (southern italy) since the roman period from archaeological and geomorphological data at palazzo degli spiriti site. quaternary international. doi: 10.1016/j.quaint.2017.12.040 aucelli p.c., cinque a., mattei g., pappone g. (2017c) late holocene landscape evolution of the gulf of naples (italy) inferred from geoarchaeological data. journal of maps, 13 (2), 300-310. auriemma r., solinas e. (2009) archaeological remains as sea level change markers: a review. quaternary international, 206(1), 134-146. barra d., cinque a., gewelt m., hurtgen c. (1991) l’ospite caldo silvestra seminis (bonaduce, masoli e pugliese, 1976) (crustacea, ostracoda): un possibile marker dell’ultimo interglaciale dell’area mediterranea. il quaternario 4, 2, 327-332. benjamina j., rovere a., fontana a., furlani s., vacchi m., inglis r.h., galili e., antonioli f., sivan d., miko s., mourtzas n., felja i., meredith-williams m., goodman-tchernov b., kolaiti e., anzideir m., gehrels r. (2017) late quaternary sea-level changes and early human societies in the central and eastern mediterranean basin: an interdisciplinary review. quaternary international, 449, 29-57. cinque a. (1991) la trasgressione versiliana nella piana del sarno (campania). geogr. fis. din. quat., 14, 63-71. brancaccio l., capaldi g., cinque a., pece r., sgrosso i. (1978) th-u dating of corals from a tyrrhenian beach in sorrentine peninsula (southern italy). quaternaria. storia naturale e culturale del quaternario 20, 175-183. cinque a., irollo g. (2013) la geografia dell’antica herculaneum e le fluttuazioni, di origine bradisismica, della sua linea di costa. in: guzzo g.p., guidobaldi m.p. (eds), atti del convegno interna-zionale nuove ricerche archeologiche nell’area vesuviana (scavi 2003-2006), roma, 425-438. di vito, m., isaia, r., orsi, g., southon, j., de vita, s., d’ antonio, m., pappalardo, l., piochi, m. (1999) volcanism and deformation since 12,000 years at the campi flegrei caldera (italy). journal of volcanology and geothermal research, 91(2), 221-246. ferranti l., antonioli f. (2007) misure del solco tirreniano (mis 5.5) nell’isola di capri: valutazione di attività tettonica durante il pleistocene superiore. il quaternario, 20(2), 125-136. lambeck k., antonioli f., anzidei m., ferranti l., leoni g., scicchitano g., silenzi s. (2011) sea level change along the italian coast during the holocene and projections for the future. quaternary international, 232, 250-257. morhange c., marriner n., laborel j., todesco m., oberlin c. (2006) rapid sea-level movements and noneruptive crustal deformations in the phlegrean fields caldera, italy. geology. 34(2), 93-96. morhange c., marriner n. (2015) archaeological and biological relative sea-level indicators. in: shennan, i., long, a. j., horton, b. p. (eds.). handbook of sea-level research. john wiley sons. passaro s., barra m., saggiomo r., di giacomo s., leotta a., uhlen h., mazzola s. (2013) multiresolution morpho-bathymetric survey results at the pozzuoli-baia underwater archaeological site (naples, italy). journal of archaeological science, 40 1268-1278. pennetta m., stanislao c., d’ambrosio v., marchese f., minopoli c., trocciola a., valente r., donadio c. (2016) geomorphological features of the archaeological marine area of sinuessa in campania, southern italy. quaternary international, 198 -213, 425. 8 amato v. et al. doi:10.1016/j.quaint.2016.04.019 putignano m. l., cinque a., lozej a., mocchegiani carpano c. (2009) late holocene ground movements in the phlegrean volcanic district (southern italy): new geoarchaeological evidence from the islands of vivara and procida. méditerranée. revue géographique des pays méditerranéens. journal of mediterranean geography, 112, 43-50. putignano m.l., orrù p.e., schiattarella m. (2014) holocene coastline evolution of procida island, bay of naples, italy. quaternary international, 332, 115-125. romano p., di vito m.a, giampaola d., cinque a., bartoli c., boenzi g., detta f., di marco m., giglio m., iodice s., liuzza v., ruello m.r, schiano di cola c. (2013) intersection of exogenous, endogenous and anthropogenic factors in the holocene land-scape: a study of the naples coastline during the last 6000 years. quaternary international 303, 107-119. simeone m., masucci p. (2009) analisi geoarcheologiche nell’area marina protetta parco sommerso di gaiola (golfo di napoli). il quaternario italian journal of quaternary sciences, 22, 1, 25-32. vacchi m., marriner n., morhange c., spada g., fontana a., rovere a. (2016) multiproxy assessment of holocene relative sea-level changes in the western mediterranean: sea-level variability and improvements in the definition of the isostatic signal. earth-science reviews, 155, 172-197. 9 palaeo sea-level markers in the gulf of naples ms. received: may 4, 2018 final text received: may 21, 2018 10 base late-quaternary alluvial fans in the northern marche apennines: implications of climate changes olivia nesci, daniele savelli , francesco troiani dipartimento di scienze dell’uomo, dell’ambiente e della natura, università “carlo bo”, urbino corresponding author: f. troiani <francesco.troiani@uniurb.it abstract: o. nesci o. et al., late quaternary alluvial fans in the northern marche apennines: implications of climate changes. (it issn 0394-3356, 2010) alluvial fans, fan-like deposits, and piedmont aprons are widespread at mountain-front and foothill sectors of the umbria-marche apennines. they are currently regarded as significant geomophological features strictly dependent on either tectonic or climatic controls. close relationship with tectonics, that are usually stressed by the location of such landforms along fault scarps or other active morphostructures, can be assessed only in the most internal areas of the umbria-marche apennines, dissected by extensional tectonics. conversely, in the piedmont and foothill sectors of the chain, the climatic control on fan deposition and entrenchment become dominant, whereas tectonic constrains can be only indirectly detected. namely, within the umbria-marche apennines, the late quaternary cyclical and systematic episodes of fan deposition and entrenchment at the mouth of tributaries, usually following the main fluvial filling along the trunk valleys, are well known. nonetheless, the main causes that have cyclically controlled the fluvial and alluvial-fan deposition and their subsequent dissection have not been thoroughly investigated yet. in this work we report a general overview on the geomorphological setting of the late quaternary alluvial fans associated with the major fill-terraces that compose the typical staircase of river terraces in the northern marche territory. in particular, for the aggradational suites of the late quaternary fillterraces, we discuss the meaningful stratigraphic relations between the fluvial sediments of the trunk streams and the alluvial-fan deposits originating from the tributaries. we also suggest a possible correlation between the cyclical recurrence of the principal episodes of fluvial aggradation/alluvial-fans formation and dissection and the principal late quaternary climate fluctuations. riassunto: nesci o. et al., conoidi alluvionali tardo quaternarie nell’appennino marchigiano settentrionale: implicazioni paleo-climatiche. (it issn 0394-3356, 2010) conoidi alluvionali tardo quaternarie (isolate e/o coalescenti) sono ampiamente diffuse lungo il fronte montuoso e l’area pedemontana dell’appennino umbro-marchigiano. le conoidi alluvionali sono correntemente considerate come significativi elementi geomorfologici in stretta connessione con la tettonica e/o con controlli di tipo climatico. relazioni molto strette con la tettonica attiva, generalmente evidenziate dalla localizzazione delle conoidi lungo scarpate di faglia o altre morfostrutture attive, sono riconoscibili solo nelle aree interne dell’appennino umbro-marchigiano, interessante da tettonica attiva di tipo estensionale. al contrario, lungo i settori pedemontani della catena è più evidente il controllo climatico sulla deposizione e successiva dissezione degli apparati di conoide alluvionale, mentre il controllo da parte della tettonica può essere riconosciuto solo in parte e indirettamente. lungo l’appennino marchigiano settentrionale, dove è incentrato il presente lavoro, da molto tempo è nota in letteratura la ciclica e sistematica ripetizione, in corrispondenza delle foci dei tributari, di alterne fasi di deposizione e re-incisione di conoidi alluvionali, le quali seguono sistematicamente fasi di aggradazione fluviale lungo i corsi d’acqua principali. nonostante ciò, le cause principali che hanno ciclicamente controllato la deposizione di ampi apparati di conoide e la loro successiva re-incisione, ancora oggi non sono state studiate nel dettaglio. nel presente lavoro viene descritto in alcune aree campione l’assetto geomorfologico delle conoidi alluvionali tardo quaternarie associate ai principali terrazzi deposizionali componenti la tipica successione di terrazzi fluviali all’interno delle principali valli marchigiane settentrionali. in particolare, vengono descritti in dettaglio i rapporti stratigrafici esistenti all’interno dei principali corpi alluvionali, di età compresa fra il pleistocene medio e il pleistocene superiore, fra le sequenze deposizionali di tipo fluviale appartenenti al corso d’acqua principale e quelle di conoide alluvionali presenti alla foce dei principali tributari. gli episodi che hanno portato alla formazione di ampi sistemi deposizionali di conoide alluvionale nei bacini marchigiani settentrionali sono ciclici e seguono sistematicamente le maggiori fasi di aggradazione fluviale lungo i corsi d’acqua principali. i depositi fluviali, fatta eccezione per i settori a ridosso dell’attuale fascia costiera, sono preservati nei principali terrazzi vallivi e vengono generalmente considerati come episodi deposizionali direttamente connessi con i principali cicli glaciali. alla stessa maniera dei depositi fluviali lungo le valli principali, anche la deposizione e successiva reincisione degli apparati di conoide in corrispondenza delle confluenze dei tributari con il corso d’acqua principale sono da ritenersi strettamente connessi con le principali fluttuazioni climatiche tardo quaternarie. inoltre, quando all’interno di un corpo alluvionale terrazzato i depositi strettamente fluviali coesistono con quelli di conoide alluvionale, fra le due tipologie di deposito esistono relazioni stratigrafiche precise e sistematiche. in particolare, i depositi di conoide seguono sistematicamente quelli fluviali; normalmente la transizione fra i depositi di conoide e quelli fluviali consiste in una rapida (fino a 2-3 m di spessore) interdigitazione di facies o, a volte, in limiti netti (anche di tipo erosivo). in ogni caso, i depositi di conoide giacciono generalmente sulla superficie non ancora rimodellata dei sottostanti depositi fluviali. il ripetersi ciclico delle fasi deposizionali ed erosive, l’esistenza di precise e sistematiche relazioni stratigrafiche fra i due depositi e la disponibilità in letteratura, almeno per i depositi più recenti (pleistocene superiore), di numerose età numeriche, hanno permesso di ipotizzare, tenendo anche in considerazione le analisi già effettuata per aree limitrofe e disponibili in letteratura, alcune correlazioni con le principali fluttuazioni climatiche tardo quaternarie. parole chiave: river terraces, alluvial fans, climatic controls, northern marche apennines. keywords: terrazzi fluviali, conoidi alluvionali, controllo climatico, appennino nord marchigiano. il quaternario italian journal of quaternary sciences 23(1), 2010 145-156 146 o. nesci, d. savelli & f. troiani 1. introduction alluvial fans are regarded by current literature as important geomorphological features in mountain-front and foothill settings, usually hinting at alternate phases of aggradations and entrenchment strictly dependent on tectonic and/or climatic control (e.g., bull, 1977; harvey, 1984; harvey et al., 2005; suresh et al., 2007 and reference therein). tectonic controls are commonly regarded as crucial to rule both sediment load and catchment relief, promoting aggradation at the mountainfront and foothills (e.g., davis, 1905; blissembach, 1954; bull, 1964; de celles et al., 1991; hartley, 1993; viseras et al., 2003). equally, climate is considered to play a fundamental role in setting the rate of sediment supply, relief equilibrium, and fan geometry (e.g., lusting, 1965; harvey, 1990, 1996; ritter et al ., 1995; roberts, 1995). whether at fronts of high-relief areas or at tributary stream junctions, alluvial fans develop where a proper accommodation space for deposition exists, and high sediment loads encounter zones of reducing stream power (harvey, 2004) because of gradient lowering and, above all, of diminished flow confinement (schumm, 1977). moreover, the rate of both sediment supply and catchment erosion is rather related to stream-power which, in turn, is generally a function of precipitation intensity (suresh et al., 2007). hence, the formation and dissection of alluvial fans in a given area is ruled by a complex interlacement of climate-related and tectonic-geologic factors, whose mutual relationships and timing are often hard to unravel. this paper reports some representative examples from the mountain-front and foothill sectors of the adriatic side of the northern marche apennines (fig. 1) in order to emphasize the close relationships in this area of systematic construction and dissection of wide alluvial fans with late quaternary climate changes. 2. river terraces in the marche apennines the marche apennines consist of a ne-verging thrust-andfold belt involving a stratigraphic succession characterized by mesozoic calcareous to marlycalcareous terrains overlain by cenozoic dominantly terrigenous terms (deiana & pialli, 1994). a series of sub-parallel ridges and topographic depresfig. 1 location map. a) the study area in the morphostructural framework of the marche region. b) shaded relief map of the study area with location of sample areas described in the text and outcrops shown in figure 5. ubicazione dell’area e dei siti descritti nel testo . a) l’area studiata nel contesto morfostrutturale del territorio marchigiano. b) dtm dell’area analizzata con l’ubicazione delle aree campione descritte e degli affioramenti illustrati in figura 5. sions (fig. 1), resulting from crustal shortening and extension driving the topographic emergence of the chain over the last three million years, generally match, respectively, the main calcareous anticlines and terrigenous synclines (calamita et al., 1991). since the lower pleistocene the area underwent a generalized tectonic uplift (bisci & dramis, 1991; dramis, 1992; d'agostino et al., 2001) gradually achieving its definitive emersion. the modern trunk valleys, characterized by an overall parallel pattern, perpendicular to the structural grain (mazzanti & trevisan, 1978; alvarez, 1999), began to develop since the messinian with the first stages of emersion, but achieved a configuration quite similar to the modern one in the lowermost part of the middle pleistocene, with the definitive emersion of the area (mayer et al. 2003). 147late-quaternary alluvial fans ... the marche region holds an excellent preservation of late quaternary valley terraces and a large number of terrace-alluvium exposures, supported for a long time by a great deal of scientific work (e.g., lipparini, 1939; villa, 1942; selli, 1954; nesci et al., 1995; coltorti et al., 1991; bisci & dramis, 1991; fanucci et al, 1996; wegmann & pazzaglia, 2009). particularly, in the central and northern sector of the marche region, cyclical stages of alluvial fans and piedmont-aprons formation and dissection have been reported in close relation (fig 2) with the valley terraces development (e.g., nesci & savelli, 1986; nesci et al., 1995). the trunk valleys show at least four “orders” of alluvial terraces, ranging from middle pleistocene to upper pleistocene in age (cf. fig. 6), and designated respectively, from the older and higher one, as t1a, t1b, t2, and t3 (nesci et al., fig. 2 composite topographic profiles and cross sections transversal to the trunk-valley axis displaying the arrangement of the principal alluvial-fan deposits in the frame of the major valley terraces in some selected areas of the northern marche apennines. the stratigraphic relationships with the fluvial fills along the trunk valleys are also shown. location of profiles in figure 1b. profili compositi trasversali agli assi vallivi che evidenziano la posizione dei principali depositi di conoide alluvionale nel contesto dei maggiori terrazzi vallivi in alcune aree campione dell’appennino marchigiano settentrionale. sono evidenziati anche i rapporti stratigrafici dei depositi di conoide alluvionale con i sedimenti delle colmate fluviali degli assi vallivi principali. ubicazione dei profili in figura 1b. 148 1990, 1995; fanucci et al., 1996). they are characterized by thick alluvial covers, often exceeding 30 metres in thickness for the only sediments supplied by the trunk-valley, i.e. without the alluvial-fan additional component which, in turn, varies in thickness from a few metres (fine grained fans, nesci & savelli, 1991) up to 25-30 metres (pebbly fans). these terraces are preceded by a complex suite of strath terraces, which, according to genetic mechanisms already described by bull (1992), have been interpreted as related to tectonic factors (fanucci et al., 1996). conversely, as regards the t1a-t3 terraced alluvial suites with which this paper is concerned, they are usually retained to be the result of as many complex, for the most part climatically-driven, aggradation episodes, alternating with likewise complex stages of predominant stream downcutting (e.g., calderoni et al., 1991, 1992; coltorti et al., 1991; nesci & savelli, 1990; 1991; nesci et al., 1995; cilla et al. 1996; coltorti, 1997; wegmann & pazzaglia, 2009). being here t1a and t1b reported as two main distinct terraces, it is worth emphasizing that this subdivision of the traditional “first order of terraces” (cf. lipparini, 1936; villa, 1942 and following authors) in two distinct main stages of terrace development -i.e. with the same “hierarchic range” of the already distinguished 2nd and 3rd “orders of terraces” has been introduced by nesci et al. (1990) just for the metauro and foglia river basins (the two principal catchments of the northern marchean area), where the traditional “first order” revealed to be unsuitable to describe the altimetric distribution of the oldest terrace-alluvium which, as a matter of fact, accounts for two main, distinct stages of terrace formation. as regards the alluvial fill stages related to the principal terrace units, the four main aggradation stages already recognized by nesci et al. (1990, 1995), match in a good way with the principal stages already described by wegmann & pazzaglia (2009) (fig. 6). the principal episodes of aggradation took place during the major stages of late quaternary climatic cooling and, generally, they were not continuous but often complicated by repeated minor episodes of cut-and-fill process (nesci et al., 1995; elmi et al., 2003). during the intervening late quaternary warmer stages, as well as during the holocene, because of the effect of both climate change and generalized tectonic uplift, stream downcutting and entrenchment exceeded valley aggradation leading to the formation of welldeveloped flights of alluvial terraces (e.g., nesci et al., 1995; di bucci et al., 2003; wegmann & pazzaglia, 2009) which are often exposed along both trunk and tributary valleys, up to 150 meters high above the present valley-floors. 3. alluvial fans in the marche apennines: overview the above delineated comprehensive framework is thus inclusive of the late quaternary alluvial fans of the northern marche area. specifically, in this general context, nesci & savelli (1986, 1990) stressed the systematic recurrence in the cycles of valley-terrace development of peculiar erosional-depositional steps. these steps are repeated quite unvaried in the t1a-t3 cycles of aggradation-dissection, to such an extent that nesci & savelli (1986 and following) called them “guide stages”/“guide deposits” to signify something hinting at a precise position in the cycle itself. hence, the valley fill resulted in a first aggradational step consisting of coarse sediments of braided rivers, even though rather complicated by subordinate cut-and-fill episodes (calderoni et al, 1991) and/or by the local occurrence of different channel-patterns (calderoni et al, 1992). the second step of the trunk-valleys aggradation consists, in turn, just in a tributary-junction related construction of alluvial fans (cf. fig. 2, 3 and 5) above the previous fig. 3 block-diagram showing the of formation (2) and dissection (3) of a wide late pleistocene alluvial fan on the right side of the metauro river valley, c.ca 1 km upstream fossombrone. stages a1, a2, e1 as in figure 6. location in figure 1b. after savelli et al. (1984), simplified. block-diagramma che illustra la formazione (2) e parziale smantellamento (3) di un’ampia conoide alluvionale del pleistocene superiore; versante destro della valle del fiume metauro, c.ca 1 km a monte di fossombrone. le fasi a1, a2. e1 si riferiscono agli eventi descritti in figura 6. ubicazione in figura 1b. da: savelli et al. (1984), semplificato. o. nesci, d. savelli & f. troiani 149 braided river plain or directly on the bedrock (nesci & savelli, 1991). from this perspective, alluvial fan deposits and related piedmont aprons – every so often merging erosional glacis (nesci et al., 2002) are spread throughout the northern marche foothills both in piedmont sectors (savelli & ballerini, 1991; nesci et al. 1993; savelli et al., 1994) and at the junction of tributary catchments with the main valley (nesci & savelli, 1986, 1991). they are part of the depositional suites of the principal alluvialterraces and have been interpreted as climatically-driven landforms related to the late quaternary glacial stages (nesci et al ., 1995). indeed, in the umbria-marche apennines some close relationships between alluvial fan development and tectonics can be stressed in correspondence of either fault scarps or active morphostructures only in the most inner areas (cattuto et al., 2004 and reference therein), dissected by extensional tectonics (lavecchia, 1988 and references therein). on the contrary, in the external sectors of the area the climate control on fan development becomes dominant and the tectonic constraints can only be indirectly detected (savelli et al., 1994; nesci et al., 2002). it is worth underlying that the term “alluvial fan” is used in this paper for alluvial depositional bodies which are directly connected with a specific point of water and sediment input and limited in the downstream (axial) direction. clast lithology highlights a supply from local catchments, while morphometric characteristics of pebbles underline a relatively short travell ing distance (fig 5b). as for other places and settings, (e. g., kochel, 1990; mukerji, 1990), the typical fan-shape can be developed or not. most of the fans of the study area do not show the characteristic shape consisting in a downslope radiating segment of cone, because of both the occurrence of confining adjacent fans and physiographic constraints, e.g. narrow valley troughs. in the same place, a progressive confinement of fans is apparent from the older fans to the most recent ones, accounting for an enhancing rate of stream entrenchment which, in turn, can be seen as the result of an increased upliftrate (nesci et al., 2002). the valfig. 4 reconstruction of the uppermost middle pleistocene (a) and late pleistocene (b) alluvial fans at isola del piano, on the north-eastern foothills of monti della cesana calcareous anticline ridge. a strong confinement of the most recent fans is obvious when compared to the coalescing fan-glacis development during the previous cycle. location in figure 1b. after nesci et al. (1993), modified. ricostruzione delle conoidi alluvionali del pleistocene medio finale (a) e del pleistocene superiore (b) nei dintorni di isola del piano, sulle pendici nord-orientali della dorsale anticlinalica calcarea dei monti della cesana. il confronto fra i due diversi eveventi di formazione di conoidi alluvionali mette in evidenza il forte confinamento che caratterizza il ciclo più recente. ubicazione in figura 1b. da nesci et al. (1993), modificato. late-quaternary alluvial fans ... 150 ley narrowing connected with the recent stream-net entrenchment, can be locally so strong that in areas where in earlier fan-formation cycles wide piedmont aprons have formed, in more recent cycles alluvial fans could not develop (savelli et al., 1994). as stated above, whatever the fan-shape, degree of confinement and location, the major northern marche fans are cyclical and are part of the alluvial fill suites of the principal valley terraces. however, this doesn’t mean that a large number of minor alluvial fans cannot form anytime and in any suitable place: widespread, scattered formation of minor fans indeed occurs almost everywhere. it is worth mentioning the large coastalfans (uppermost pleistocene-lowermost holocene) which, with a sea level lower than today, developed close to the modern river mouths because of the removal of huge alluvial masses during the first dissection stages of the upper-pleistocene alluvial plains (di bucci et al., 2003; nesci et al., 2008; calderoni et al., 2008). other examples can be observed, which consist of a wide range of forms every so often active and frequently grading to scree cones (cf. fig 3.3), which and are in relation with both land use and ongoing deep-seated slope gravitational deformations: an example of this latter is the san lazzaro fan reported by francavilla (1976) (cf. fig. 2 f-f’). what follows is a synthetic description of some selected sites, which can be regarded as representative for the whole northern marche sector of both piedmont pediment areas and of tributary junctions with trunk valleys. the sites have been chosen in order to highlight those cases where there are accounts in the same place of a systematic repetition of alluvial-fan deposits in the main fill sequence of each principal terrace, and where relationships with the trunk-valley terrace-alluvium can be easily assessed. the objective is to stress the cyclical recurrence of wide alluvial fan depositional systems, highlighting the stratigraphic relationships between alluvial-fan deposits and fluvial fill of the trunk valleys, and to underline the occurrence of a peculiar sequence of alluvial bodies which can be retained as the result of late quaternary climatic-driven sedimentary and geomorphic processes. 4. alluvial fans in the marche apennines: case studies 4.1 metauro river valley, fossombrone site (figs. 2 ff’, 3 and 4) this site extends for a few kilometres just fig. 5 the characteristic patterns of stratigraphic superposition of alluvial-fan deposits above fluvial sediments in a typical fill-terrace of the northern marchean area. a. sketch displaying the stratigraphic relationships between fluvial (f) and fan (af). b-e. some explicative outcrops and lithologic and morphometric differentiation between fluvial and alluvial fan deposits. location of outcrop areas in figure 1b. le diverse modalità nella sovrapposizione stratigrafica dei depositi di conoide alluvionale sui sedimenti fluviali nella fase aggradazionale di un tipico ciclo di terrazzamento vallivo principale dell’area marchigiana settentrionale. a. schema dei rapporti stratigrafici fra i depositi fluviali (f) e quelli di conoide alluvionale (af). b-e. il contatto in alcuni affioramenti significativi e alcuni elementi di differenziazione fra i depositi fluviali e quelli di conoide alluvionale. ubicazione degli affioramenti in figura 1b. o. nesci, d. savelli & f. troiani upstream fossombrone, where the metauro river crosses the monti della cesana anticline ridge (fig. 1) cutting a rather narrow valley-segment in the calcareous meso-cenozoic units of the umbria-marche succession. three different stages of alluvial fan formation can be observed, related to as many major terracefill events, i.e. t3, t2 and t1 (cf. fig. 6), and each characterized by a thickness ranging from 5 to 15 metres. the late pleistocene fans (t3 fill stage) are preserved at the junction of the widest part of the tributaries with the trunk valley, although a severe dismantling occurred because of both a pronounced lateral erosion performed by the metauro river during the downcutting stage (cf. fig. 3.3), and a strong gravitational instability of a wide sector of the left valley-side. the wide and wellformed holocenic fan already described by francavilla (1976) can also be noticed on the left valley side, where several scree cones and an important landslide accumulation also occur, due to huge, slow deep-seated gravitational movements (pergolini et al., 2001). nonetheless, it is worth underlining that close to the junction of the tributary valley from which this recent fan takes origin, residual patches of an older fan are found hanging on the flanks of the tributary valley in a position clearly correlable with the late pleistocene fan deposits occurring in nearby sectors (e.g. the fan shown in fig. 3). the fans of the uppermost middle pleistocene (i.e. t2 fill stage, cf. fig. 6) are preserved in some small patches on the right side of the metauro valley, resting above fluvial gravels of the t2 fluvial fill and/or directly on bedrock. it is worth emphasizing that, in a general way, fan deposits rest directly on bedrock both upstream along the tributary valley which fed the fan and/or in several internal sectors of the trunk valley, where fill terraces are often substituted by strath terraces. a patch of middle pleistocene alluvial-fan deposits can be observed in a higher position on the right valleyside (fig. 2), resting above the fluvial gravels of the t1 (t1b according with the attribution of nesci et al., 1990). they have a scant morphological emphasis because of strong remoulding, which is at least in part related to the fine-grained nature of the deposit, supplied chiefly by marly and marly-calcareous units. 4.2 metauro river valley, sant’angelo in vado site (fig. 2 v-v’) the site is set a few kilometres downstream of sant’angelo in vado, on the right side of the valley segment that crosses the north-western termination of the catria-nerone anticline ridge (fig. 1). along the valley reach enclosing the site, terraces are preserved at different heights above the modern valley floor which account for four principal fill-stages, the oldest and highest of which has been referred to the t1a (monte proverso terrace, 210 m above the thalweg, according to nesci et al., 1990). the composite profile in fig. 2 crosses the valley in an area where the oldest terrace (t1a) is not preserved, but some previously unreported t1b terraces occur (t1 in fig 2), one of which consisting of both fluvial and alluvial-fan deposits. these deposits, more than 15 meters thick, lie on the top of fluvial deposits at the most external fan-zone, whereas, 151 fig. 6 the principal stages in the development of the main valley terraces in the northern marche apennines: the position of principal episodes of downcutting and aggradation, including alluvial fan formation stages, are shown. plotting against the oxygen isotope curve of lisiecki & raymo (2005), after wegmann & pazzaglia (2009), simplified. le principali fasi erosionali e aggradazionali, con i maggiori episodi di formazione di conoidi alluvionali, nell’evoluzione dei principali terrazzi vallivi dell’appennino marchigiano settentrionale. riferimento alla curva isotopica dell’ossigeno di lisiecki & raymo (2005), sulla base del lavoro di wegmann & pazzaglia (2009), semplificato. late-quaternary alluvial fans ... toward the fan-apex zone, they generally overlay the bedrock. the alluvial fan deposits show a well-preserved top-surface, characterised by a very gentle dipping towards the trunk-valley axis, and covered by a thick decalcified, reddish-yellowish relict soil. more downslope, any patch of alluvial fan deposits related to previous t2 terrace can be observed, likely because of erosional removal, although remains of such deposits occur both upand down-valley. in this respect, it is worth underlying that previous t1b related fan deposits could be preserved because of their topographic location, resting on a local wide divide. conversely, deposits of alluvial fans connected with the t3 fill stage are well preserved in several wide terraces at the junction of tributaries with the trunk valley. 4.3 foglia river valley, colbordolo site (fig. 2 c-c’) this site is located on the right flank of the foglia river valley, roughly between the villages of colbordolo and montefabbri, where the trunk stream crosses an anticline ridge made up mainly of cenozoic marly-calcareous terrains (fig. 1). here, three main fill terraces are preserved, namely t1b (t1 in fig 2), t2, t3. not so different from the already described examples, the fill of each principal terrace consists of both fluvial and alluvial-fan sediments, with preserved thicknesses of fan deposits sometimes exceeding 20 metres. 4.4 monti della cesana piedmont area, isola del piano site (fig. 4) the site is located on the north-eastern foothills of the monti della cesana anticline ridge consisting of mainly calcareous meso-cenozoic terrains (fig. 1). it is an example of alluvial fans finding – at least during some specific cycles of late quaternary fan construction their accomodation space not in an aggraded valley floor, but in a piedmont area wide enough to allow an erosional-depositional glacis to develop. similar examples are diffused in several areas of the central and northern marche region, both on authoctonous terrains (savelli & ballerini, 1991; nesci et al., 1993, 1995, 2002) and in allochthonous ones (guerra & nesci, 1999; nesci et al., 2002). the piedmont area around the village of isola del piano shows wide late pleistocene fill terraces (fig. 4b) characterised by mainly gravel alluvium, averaging 20-25 metres in thickness, supplied by small catchments draining the monti della cesana ridge to the north-east, which accounts for a narrow, sw-ne elongated, confined alluvial fan (nesci et al., 1993, 2002). at higher elevations, several patches of terraced alluvial-fans deposits are found, allowing (nesci et al., 2002) to reconstruct the depositional top-surface with enough accuracy to assess the occurrence of an ancient system of partially coalescent fans. these have been correlated to several scattered remains of a wider erosional surface, hinting at a rather smooth piedmont area shaped in a wide glacis both by fan accretion and by areal erosion (fig 4a). on the basis of morpho-stratigraphic correlation all along the piedmont area and towards the metauro river valley, a reliable attribution to the uppermost middle pleistocene (t2) events of terraces development can be made (nesci et al., 2003). the isola del piano piedmont is also an area where the confinement of alluvial fans in narrow valley troughs during the late pleistocene is particularly clear, a fact that – as mentioned above has been related with an increasing downcutting driven, in turn, by an enhancing rate of uplift. 5. discussion and conclusions during late quaternary, a generalized crustal uplift gradually diminishing in intensity to the north-east, affected the northern marche apennines promoting the formation of river terrace staircases which – including the flights of erosional terraces already described by fanucci et al. (1996) along the main valley sides, reaches heights of up to 300 meters above the present valley-floors (di bucci et al., 2003 and references therein). in such a frame of progressive uplift the major late quaternary cyclic climatic fluctuations (i.e., glacialsinterglacials) can be retained to have driven temporary depositional episodes that promoted the formation of middle pleistocene-upper pleistocene fill-terraces, namely the terrace units referred as t1a, t1b, t2, and t3 (cf. fig. 6) according to fanucci et al. (1996). the flight of valley terraces exposed along the flanks of the main fluvial valleys, generally developed through a complex series of fill and dissection processes, stand for the most evident expression of the so called “rhythmical succession of cycles”, already underlined by lipparini (1936). such “rhythmical succession of cycles”, however, also include other specific morphoevolutive episodes (both erosional and depositional); in particular, among depositional events, the most outstanding and diffuse features are the alluvial-fan deposits, widespreading over the mountain-front and foothills of the umbria-marche apennines (nesci & savelli, 1986, 1990). namely, alluvial fans are an integral part of the alluvial valley-fillings, as they usually associate with fluvial deposits along the trunk valleys (i.e., fluvial sediments are systematically topped with alluvial-fan deposits, cf. fig. 2). on the other hand, at the foothills of the major anticline ridges which characterize the most internal areas, the alluvial-fan sediments/landforms are the only significant alluvial contributors to terrace formation (fig. 4), often coalescing to form typical piedmont aprons (e.g., savelli & ballerini, 1991; savelli et al., 1994; nesci et al., 2002). in the examined areas, the major alluvial fillings are currently considered as climate driven events (coltorti et al., 1991; nesci et al., 1995; wegmann & pazzaglia, 2009). at the same time, the cyclical formation of large alluvial-fan depositional systems at the junction of small tributaries with the trunk-valley and at the foothills of the major anticline ridges of the northern marche apennines, is to be regarded as climate-controlled (nesci et al., 1995). in this context, the geomorphologic analysis of the alluvial fans that directly connect to the major fill terraces exposed within the study area has led to some remarkable considerations, as follows. as shown in figure 2, the formation of wide and thick alluvial fans is systematic and cyclical and is directly connected with the major fluvial fill stages along the trunk valleys. in particular, where both fluvial and fan depositional events occur, the fan deposits systematically follow the fluvial ones, generally overlaying the top of the fluvial fill belonging to the same depositional 152 o. nesci, d. savelli & f. troiani cycle (cf. fig. 6). the most frequent boundaries between the two depositional sequences belonging to the same depositional events are either unconformably erosional or sharp conformable as shown in figure 5. in several cases, however, the boundary results heteropic, with alternation of typical fluvial coarse sediments and locally-derived alluvial fan deposits. where this typology of boundary occurs the thickness of deposits characterized by such alternation is rather low, usually less than 2-3 metres (nesci & savelli, 1991) in a cumulative thicknesses (i.e. fluvial + fan) every so often exceeding 40-50 m. hence, notwithstanding the typology of the stratigraphic boundary, the fan deposits always lie above undissected tops of fluvial sediments (figs. 2, 3). this pattern highlights the occurrence of specific stratigraphic relations (i.e., superposition), and a rather clear chronological succession between the two distinct depositional sequences. namely, in a first time the trunk valley experiences a fluvial filling by aggradational behaviour of the main stream; afterwards, at the junction of the tributaries, alluvial fan systems develop. the t3 terrace has to be regarded as an unavoidable key element to reconstruct the morphoevolutive events in the study area. in fact, the t3 terrace is generally well developed along the northern marche trunk valleys, furthermore it is usually spatially continuous and well constrained by several radiocarbon ages (calderoni et al., 1991; nesci et al., 1995; elmi et al., 2003; calderoni et al., 2008). these latter characteristics, in particular, allow us to define a well constrained morphoevolutive pattern and reasonably correlate the late pleistocene depositional/erosional events with the main late quaternary climatic fluctuations (fig. 6). since a cyclically recurrent suite of peculiar depositional and erosional events characterize each major fill terrace, it is plausible to extrapolate the results obtained for the late pleistocene fill terrace to the older terrace levels (middle pleistocene and uppermost middle pleistocene terraces), as already indirectly demonstrated, for example, in the detailed analysis proposed by wegman & pazzaglia (2009). namely, the t3 terrace becomes an interpretative guide for the analysis of the older fill terraces and, moreover, for the analysis of fill-terrace staircases through the whole umbria-marche area. in this frame, the most striking expression of the late quaternary cyclical depositional events is the cyclical formation of al luvial-fan depositional systems. therefore, the interpretation of the alluvial fan development as climate-driven depositional events despite some dating problems, as at the next point actually can be reasonably projected to the middle pleistocene (t1) and to uppermost middle pleistocene (t2) terraces. on the other hand, alluvial fans are not the only feature fit for this purpose. indeed, among the others, some features that appear to support the assertion of an effective usefulness of some repetitive facies and erosional patterns in both the reconstruction and interpretation of late quaternary morphogenetic cycles, are, for example: i) the systematic repetitiveness of the thickness of both fluvial fills and overlying alluvial fan deposits (cf. bull, 1992); ii) the systematic pattern of the reincision that involve the alluvial fills and, at least in part, the bedrock, promoting the formation of both strath terraces (fig. 2) and ingrown meanders (cf. fig. 3.3). furthermore, in the same perspective the cyclical formation can be also interpreted along the downstream sector of the main northern marche trunk valleys of typical coastal fans merging in a coeval coastal plain, as already suggested by calderoni et al. (2008). it is necessary to underline that for alluvial fan deposits in general, and even more so for those of the alluvial fans of the piedmont sectors of the calcareous anticline ridges which hardly reveal peculiar, clarifying stratigraphic relationships with the alluvial fills of the trunk valleys a very scant number of radiometric ages is available both for the whole marche apennines and for the studied areas. hence, any chronological attribution and/or correlation with other deposits rests more on circumstantial evidence than on analytical data. indeed, calderoni et al. (1991) stressed how the cesano river deposits – but such consideration is equally reliable for the other northern marche rivers only the lower half of the terrace-fill hold wood fragments suitable for dating, since the upper section was lacking in any appropriate materials. on account of this, they performed an indirect computation of the expected age for the upper part of the alluvial suite, reaching an estimate that today sounds quite near to the ages reported by wegmann & pazzaglia (2009). furthermore, some available radiometric ages of alluvial deposits of the marche apennines which have been retained “other” than alluvial fans (e.g. uncorrected 14c ages of 23,500±400 of calderoni et al., 1992 for the upper esino river basin, and 23,500±1200 of mencucci et al. 2003 for the lower foglia river basin) could instead be reasonably referred to fan deposits. as a matter of fact, much work is to be done to achieve – every so often through expensive analytical procedures a larger amount of numeric ages able to detail the chronological attribution and to provide a further advance in genetic explanation of these deposits. however, as targeted by this paper, a detailed field work and the reconstruction of mutual relationships between different sedimentary bodies, between them and certain peculiar erosional events, and between them and specific diagnostic landforms is essential to depict a morpho-sedimentary correlative and evolutive frame as that shown in figure 6, which is capable of eventually being adjusted by further analytical data and/or in which such data can be suitably set. based on the above considerations on the scant availability of numeric chronological constraints for both the upper part of the trunk-stream fills and alluvial fan deposits, a major question regards the fans and aprons of the piedmont areas around the major carbonate anticline ridges. in fact besides lacking in numeric ages, they hardly display obvious stratigraphic relationships with trunk-valley fills. indeed, if their correlation with the fans occurring at the junction of the tributaries on the trunk-valleys were effective, a diachronism with respect to the same trunk-valley fill should result (cf. figs. 2, 5, 6). actually, in certain areas where the downstream termination of some wide piedmont aprons reaches the trunk-valley, a superposition on valley trough fill-deposits is still well recognisable. as an example, the deposits of the coalescing fans of acquaviva, at the foothills of catria-nerone anticline ridge (fig. 1), whose downstream termination reaches the trunk-valley (burano river). here the fan deposits overlay the fluvial valley-fill sediments (savelli & ballerini, 1991), thus hinting at a 153late-quaternary alluvial fans ... downstream extension of the piedmont alluvial-system that expands upon the already formed alluvial-plain of the trunk valley. it is worth emphasizing that the same piedmont alluvium of acquaviva displays a complex evolution which, starting with alluvium supplied from the south-east (i.e. from longitudinal streams), continues with the deposition of huge amounts of alluvium sourced from the south-west (i.e. from the catrianerone carbonate anticline ridge) and thus distributed in an overall transverse direction (savelli & ballerini, 1991). this seems to account specifically for a transition from along-valley aggradation, possibly correlated with the ongoing trunk valley filling-up, to a huge deposition by overburden tributary streams, which joined trunk streams no longer capable and competent to transport the huge sedimentary load supplied from the minor catchments. it is exactly the case of the alluvial fans observed at the junction of tributary streams on the trunk valleys (figs. 2, 3, 5 and 6). similar behaviours, indeed, indicating significant variations in functional interaction between the trunk-stream and its tributaries, also from a conceptual standpoint could strengthen the idea of a chronologic shifting of alluvial sedimentation loci towards the piedmont zones, thus accounting for the stages of generalized development of coalescing fans observed on the foothills of the carbonate ridges. references alvarez w. (1999) drainage on evolving fold-thrust belts: a study of transverse canyons in the apennines. basin research, 11, pp. 267-284. bisci c. & dramis f. (1991) la geomorfologia delle marche. in: l’ambiente fisico delle marche, regione marche – giunta regionale, assessorato urbanistica e ambiente, s.e.l.c.a., firenze, pp. 81-113. blissembach e. (1954) gelogy of alluvial fans in semiarid regions. geological society of american bulletin, 65, pp. 175-190. bull w.b. (1964) geomorphology of segmented alluvial fans in western fresno county, california. u.s. geol. survey professional paper, 352-e, pp. 89-129. bull w.b. (1977) the alluvial fan environment. progress in physical geography, 1, pp. 222-270. bull w.a. (1991) geomorphic response to climatic change. j. wiley & sons, n.y., 326 pp. calamita f., deiana g., invernizzi c. & pizzi a. (1991) tettonica. in: l’ambiente fisico delle marche, regione marche – giunta regionale, assessorato urbanistica e ambiente, s.e.l.c.a., firenze, pp. 69-80. calderoni g., nesci o. & savelli d. (1991) terrace fluvial deposits from the middle basin of cesano river (northern marche apennines): reconnaissance study and radiometric constraints on their age. geografia fisica e dinamica quaternaria, 14, pp. 201-207. calderoni g., coltorti m., dramis f., magnatti m. & cilla g. (1992) sedimentazione fluviale e variazioni climatiche nell’alto bacino del fiume esino durante i l pleistocene superiore . atti del convegno “erosione ed alluvionamento in aree caratterizzate da subsidenza o da tettonica attiva”, ancona, 15-15 ottobre 1991, pp. 171-190. calderoni g., della seta m., fredi p., lupia palmieri e., nesci o., savelli d. & troiani f. (2008) late quaternary geomorphological evolution of the adriatic coast reach encompassing the metauro, cesano and misa river mouths (northern marche, italy). geoacta, special pubblication 3, pp. 49-64. cilla g., coltorti m., dramis f., farabollini p., gentili b., pambianchi g. (1996) fluvial sedimentation during the early holocene in the marchean valleys (central italy). il quaternario, 9, pp. 459-464. coltorti m. (1997) human impact in the holocene fluvial and coastal evolution of the marche region, central italy. catena, 30, pp. 311-335. coltorti m., consoli m., dramis f., gentili b. & pambianchi g. (1991) evoluzione geomorfologica delle piane alluvionali delle marche centro-meridionali. geografia fisica e dinamica quaternaria, 14, pp. 87-100. d'agostino n., dramis f., funiciello r. & jackson j.a. (2001) interactions between mantle upwelling, drainage evolution and active normal faulting: an example from central apennines (italy). geophysical journal international, 147, pp. 475-497. davis w.m. (1905) the geographical cycle in an arid climate. journal of geology, 13, pp. 381-407. de celles p.g., gray m.b., ridgway k.d., cole r.b., srivastava p., pequera n. & pivnik d.a. (1991) kinematic history of a foreland uplift paleocene synorogenic conglomerate, beartooth range, wyoming and montana. geological society of american bullettin, 103, pp. 1458-1475. deiana g. & pialli g. (1994) the structural provinces of the umbro-marchean apennines. memorie della società geologica italiana, 48, pp. 473-484. di bucci d., mazzoli s., nesci o., savelli d., tramontana m., de donatis m. & borraccini f. (2003) active deformation in the frontal part of the northern apennines: insights from the lower metauro river basin area (northern marche, italy) and adjacent adriatic off-shore. journal of geodynamics, 36, pp. 213-238. dramis f. (1992) il ruolo dei sollevamenti tettonici a largo raggio nella genesi del rilievo appenninico. studi geologici camerti, special volume 1992/1, pp. 9-15. elmi c., forti p., nesci o. & savelli d. (2003) la risposta dei processi geomorfologici alle variazioni ambientali nella pianura padana e veneto-friulana, nelle pianure minori e sulle coste nord e centroadriatiche. in: biancotti a. & motta m. (eds.) risposta dei processi geomorfologici al le variazioni ambientali, glauco brigati, genova, pp. 225-259. fanucci f., moretti e., nesci o., savelli d. & veneri f. (1996) tipologia dei terrazzi vallivi ed evoluzione del rilievo nel versante adriatico dell'appennino centro-settentrionale. il quaternario, 9, pp. 255258. francavilla f. (1976) alvei paralleli del fiume metauro a s. lazzaro di fossombrone (marche settentrionali). studi geologici camerti, 2, pp. 107-112. guerra c. & nesci o. (1999) glacis pleistocenici nel 154 o. nesci, d. savelli & f. troiani montefeltro (appennino marchigiano-romagnolo). in: orombelli g. (ed.) studi geografici in onore di severino belloni. glauco brigati, genova, pp. 419-428. hartley a.j. (1993) sedimentological response of an alluvial system to source area tectonism: the seilao member of the late cretaceous to eocene purilactis formation of northern chile. in: marzo m. & puigdefabregas c. (eds.) alluvial sedimentation. international association of sedimentologists, special publication, 17, pp. 489-500. harvey a.m. (1984) aggradation and dissection sequence on spanish alluvial fans: influence on morphological development. catena, 11, pp. 289-304. harvey a.m (1990) factors influencing quaternary alluvial fan development in southeast spain. in: rachoki a.h. & church m. (eds.) – alluvial fans, a field approach. j. wiley and sons, chichester, pp. 247-269. harvey a.m. (1996) the role of alluvial fans in the mountain fluvial systems of southeast spain: implications of climatic change. earth surfaces processes and landforms, 21, pp. 543-553. harvey a.m. (2004) alluvial fan. in: goudie a.s. (ed.) encyclopedia of geomorphology, vol. 1, pp. 1519. harvey a.m., mather a.e. & stokes m. (2005) alluvial fans: geomorphology, sedimentology, dynamics – introduction. a review of alluvial-fan research. geological society of london, special publication, 251, pp.1-7. kochel r.c. (1990) humid fans of the appalachian mountains. in: rachocki a. h. & church m. (eds.) alluvial fans. a field approach. j. wiley & sons, chichester, pp. 109-129. lavecchia g. (1988) the tyrrhenian-apennine system: structural setting and seismotectogenesis. tectonophysics, 147, pp. 263-296. lipparini t. (1938) i terrazzi fluviali delle marche. giornale di geologia, bologna, 13, pp. 5-22. lisiecki l.e. & raymo m.e. (2005) a pliocenepleistocene stack of 57 globally distributed benthic d18o records. paleocenography, 20, pa1003, doi:10.1029/2004pa001071. lusting l.k. (1965) clastic sedimentation in deep springs valley, california. u.s. geol. survey professional papers, 352-f, pp. 131-192. mayer l., menichetti m., nesci o. & savelli d. (2002) morphotectonic approach to the drainage analysis in the north marche region, central italy . quaternary international, 101-102, pp. 147-157. mazzanti r. & trevisan l. (1978) evoluzione della rete idrografica nell’appennino centro-settentrionale. geografia fisica e dinamica quaternaria, 1, pp. 55-62. mencucci d., colantoni p. & nesci o. (2003) the foglia river alluvial system (northern marche) and its relation to the late quaternary evolution of the central adriatic shelf. il quaternario., 16, pp. 43-50. mukerji a. b. (1990) the chandigarh dun alluvial fans: an analysis of the process-form relationship. in: rachocki a. h. & church m. (eds.) alluvial fans, a field approach. j. wiley & sons, chichester, pp. 131-149. nesci o. & savelli d. (1986) cicli continentali tardoquaternari lungo i tratti vallivi mediani delle marche settentrionali. geografia fisica e dinamica quaternaria, 9, pp. 192-211. nesci o. & savelli d. (1990) valley terraces in the northern marche apennines (central italy): cyclic deposition and erosion. giornale di geologia, serie 3°, 52, pp. 189-195. nesci o. & savelli d. (1991) successioni alluvionali terrazzate nell'appennino nord-marchigiano. geografia fisica e dinamica quaternaria, 14, pp. 149162. nesci o., savelli d., mengarelli d. (1990) i terrazzi vallivi del 1° ordine nei bacini dei fiumi metauro e foglia (appennino marchigiano). geografia fisica e dinamica quaternaria, 13 (1), pp. 63-73. nesci o., savelli d., tramontana m. & fattori d. (1993) evoluzione tardo-pleistocenica delle dorsali calcaree nord-marchigiane: un esempio dai monti della cesana. il quaternario, 7, pp. 139-144. nesci o., savelli d., calderoni g., elmi c. & veneri f. (1995) le antiche piane di fondovalle nell’appennino nord-marchigiano. in: castiglioni g.b. & federici p.r. (eds.) assetto fisico e problemi ambientali delle pianure italiane. memorie della società geografica italiana, 53, pp. 293-312. nesci o., savelli d., tramontana m., veneri f., de donatis m. & mazzoli s. (2002) the evolution of alluvial fans in the umbria-marche-romagna apennines (italy). bollettino della società geologica italiana, special volume, 1, pp. 915-922. nesci o. savelli d. & troiani f. (2008) evoluzione tardo quaternaria dell’area di foce del fiume metauro (marche settentrionali). collana dell’autorità di bacino della basilicata, 9, pp. 443-451. pergolini c., savelli d. & tramontana m. (2001) itinerario 6. dal metauro ai monti della cesana. in: ciarapica g. & passeri l. (eds.) appennino umbro-marchigiano, 34 escursioni a piedi. guide geologiche regionali a cura della società geologica italiana, be-ma editrice, 7 (2), pp. 52-58. ritter j.b., miller j.r., enzel y. & wells s.g. (1995) reconciling the roles of tectonism and climate in quaternary alluvial fan evolution. geology, 23, pp. 245-248. roberts n. (1995) climatic forcing of alluvial fan regimes during the late quaternary in konya basin, south central turkey. in: lewin j., macklin m.g. & woodward j. (eds.) – mediterranean quaternary river environments. balkema, rotterdam, pp. 205-217. savelli d. & ballerini l.s. (1991) alluvioni pedemontane terrazzate fra cagli e frontone (appennino marchigiano): un esempio di conoidi alluvionali confinate. geografia fisica e dinamica quaternaria, 14, pp. 179-181. savelli d., bartole r. & moretti e. (1984) caratteristiche litostratigrafiche con l'ausilio del sismografo di un terrazzo alluvionale del fiume metauro a fossombrone (marche settentrionali). ateneo parmense, acta naturalia, 20 (1), pp. 63-79. savelli d., nesci o. & mengoni s. (1994) from alluvial fans to intravallive floodplain: a case study from the piedmont terrace alluvium of the upper musone river basin (marche apennines). giornale di geologia, serie 3, 56/2, pp. 27-42. 155late-quaternary alluvial fans ... schumm s. a. (1977) the fluvial system. j. wiley & sons, new york, 388 pp. selli r. (1954) il bacino del metauro. giornale di geologia, serie 2, 24, pp. 5-268. suresh n., bagati t.n., kumar r. & thakur v.c. (2007) evolution of quaternary alluvial fans and terraces in the intramontane pinjaur dun, sub-himalaya, nw india: interaction between tectonics and climate change. sedimentology, 54, pp. 809-833. villa g.m. (1942) nuove ricerche sui terrazzi fluviali delle marche. giornale di geologia, serie 2, 16, pp. 5-75 viseras c., calvache m.l., soria j.m. & fernandez j. (2003) differential features of alluvial fans controlled by tectonic or eustatic accommodation space. examples from the betic cordillera, spain. geomorphology, 50, pp. 181-202. wegmann k.w. & pazzaglia f.j. (2009) late quaternary fluvial terraces of the romagna and marche apennines, italy: climatic, lithologic, and tectonic controls on terrace genesis in an active orogen. quaternary science reviews, 28, pp. 137-165. 156 ms. ricevuto il 18 giugno 2009 testo definitivo ricevuto il 5 ottobre 2009 ms. received: june 18, 2009 final text received: october 5, 2009 o. nesci, d. savelli & f. troiani stratigrafia e paleogeografia del “lacus timavi” (friuli venezia giulia) ruggero marocco1 & romana melis1 1dipartimento di scienze geologiche, ambientali e marine, università di trieste, e-mail: melis@units.it riassunto: marocco r. & melis r., stratigrafia e paleogeografia del “lacus timavi” (friuli venezia giulia). (it issn 0394-3356, 2009). e’ stato condotto uno studio lito-biostratigrafico sull’immediato sottosuolo del lisert (monfalcone), un area paludosa posta alle pendici del carso in prossimità delle foci del timavo, ricca di testimonianze della presenza romana. scopo della ricerca è la ricostruzione paleogeografia del territorio che studi precedenti hanno solamente tratteggiato, a partire dall’olocene fino all’insediamento romano, testimoniato da numerosi siti archeologici e da diverse citazioni letterarie (insulae clarae, lacus timavi, ecc..). le successioni stratigrafiche individuate nei diversi sondaggi analizzati indicano che almeno a partire da 4370 ÷ 4220 anni a.c. il territorio dell’attuale lisert era ricoperto da un’ampia laguna che inglobava i rilievi calcarei delle insulae clarae (oggi spianati) e si estendeva anche a sud delle stesse per alcuni chilometri. successivamente si è verificata una trasgressione che ha determinato un progressivo ampliamento del bacino lagunare interno e nel contempo una probabile diversione fluviale ha portato all’emersione dell’area a sud delle insulae. ai margini di questo bacino, nelle aree sabbiose-pelitiche vegetate, si segnala l’esclusiva presenza di ammoscalaria runiana (heronallen & earland), piccolo foraminifero agglutinante che vive attualmente nelle piane fangose delle alte latitudini europee e che non è stato segnalato in adriatico. in epoca romana l’ambiente paralico-lagunare si manteneva all’interno del lisert e recuperava i margini meridionali delle i n s u l a e clarae. questa configurazione meridionale della costa probabilmente è stata determinata dalla presenza immediatamente ad ovest della foce di un ramo progradante dell’isonzo. i depositi paralici della piana del lisert rientrano nell’ampio intervallo di variabilità della curva profondità-età di tutti gli altri analoghi depositi datati lungo la costa veneto-friulana. sulla base di questo unico dato non è possibile definire con precisione il contributo dei movimenti verticali del suolo nella determinazione dell’evoluzione costiera dell’agro monfalconese, anche se ci sono forti indizi di una certa attività tettonica. abstract: marocco r. & melis r., stratigraphy and palaeogeography of the “lacus timavi” area (friuli venezia giulia). (it issn 0394-3356, 2009). a litho-biostratigraphic study of the immediate subsoil of lisert area (monfalcone) has been carried out. this marshy area, located at the foot of the karst near the mouth of the timavo river, is rich in evidence of the roman culture. this research focuses on the paleogeographic reconstruction of the territory that previous studies have only outlined, starting from the holocene until the roman settlement, testified by numerous archaeological sites and several literary quotations (insulae clarae, lacus timavi, etc. ..). the stratigraphic sequence identified in different analyzed cores, reveals that at least from 4370 ÷ 4220 yrs b.c. the lisert territory was covered by a large lagoon which incorporates the insulae clarae limestone outcrops (now smooth) and also extended to the south of the same for several kilometres. subsequently there was a transgression that led to a progressive widening of the lagoon basin, but at the same time a probable river diversion has led to the emergence of south insulae. the marginal vegetate settings of this basin, characterized by sandy-pelite sediments, include the exclusive presence of ammoscalaria ruinana (heron-allen & earland), little agglutinated foraminifer that currently lives in the european high-latitude mud flats and has not been reported in the adriatic sea. in the roman period the lagoon environment had gradually expanded toward the southern margins of insulae clarae. this configuration of the southern coast was probably determined by the immediate west occurrence of the mouth of an isonzo river branch. the paralic deposits of the lisert plain fall into the range of variability of the depth age curve of all the other similar dated deposits located along the venetian-friulian coast. this makes it impossible to define the contribution of tectonics in the determination of the coastal field of monfalcone, although there are strong indications of its activity. parole chiave: olocene, piana costiera, stratigrafia, paleogeografia, lisert, friuli venezia giulia. keywords: holocene, coastal plain, stratigraphy, palaeogeography, lisert, friuli venezia giulia. il quaternario italian journal of quaternary sciences 22(2), 2009 157-170 1. introduzione i recenti progetti di rilancio dell’area portuale di monfalcone (gorizia) e segnatamente quelli eseguiti a fini turistico-ricettivi e termali della vasta area del lisert, l ’ a n t i c o lacus timavi, hanno comportato una serie di interventi per la caratterizzazione e la bonifica del territorio, interessato nel recente passato da discariche urbane ed industriali. nell’occasione si è anche saggiata la potenzialità dell’antica piana palustre per una sua fruizione turistico-archeologica, resa quanto mai plausibile dall’attestata presenza in loco delle famose terme romane, contornate da ville mosaicate e da approdi nautici, ubicate a poca distanza dalle celeberrime sorgenti del timavo. quest’area è già stata oggetto, nel 1995, di alcune indagini geoarcheologiche condotte su due sondaggi (sm 1 e sm 2) posti a cavallo dei rilievi di san antonio e di amarina (montenegro m.e. & pugliese n., dati inediti). a tali scopi il consorzio per lo sviluppo industriale del comune di monfalcone, di concerto con la locale soprintendenza e con l’arpa, ha fatto eseguire in più riprese una serie di sondaggi geognostici che hanno interessato i primi 10 metri del sottosuolo. in particola158 r. marocco & r. melis re, una prima serie di sondaggi è stata effettuata a monte delle terme del lisert nel novembre del 2004. successivamente, nell’ottobre del 2005, lo stesso ente ha fatto eseguire nel la stessa area altri 5 sondaggi geognostici (sondaggi s1, s2, s3, s4 e s5 di fig. 1), che si sono spinti da 5 a 15 m di profondità dal piano campagna (fig. 1; tab. 1). su r ichiesta della soprintendenza del friuli venezia giulia questi sondaggi sono stati analizzati in termini lito-, bioe crono-stratigrafico, al fine di delineare l’evoluzione paleogeografica di questo territorio che in epoca romana ha avuto una notevole importanza storico-commerciale. 2. inquadramento geologico-idrografico del lacus timavi il lacus timavi si ubica sull’attuale piana del lisert che rappresenta il lembo più orientale della pianura veneto-friulana, delimitato dalle balze sud-occidentali dell’altopiano calcareo del carso (fig. 1). a meridione la piana è chiusa dai resti del colli di san antonio (ex-quota 21 m dal l .m.m.) e dell’isola della punta o amarina (ex-quota 15 dal l.m.m.) le famose i n s u l a e c l a r a e dell’antichità, completamente sbancati per far spazio alle industrie siderurgiche attuali; ad oriente l’area planiziale riceve i contributi dei corsi d’acqua attuali e recenti, che scorrono nelle vallecole di moschenizza (locovaz), e quelli delle diverse bocche del timavo. la fascia costiera che delimita la piana è costituita essenzialmente da depositi peliticosabbiosi di ambiente paludosolitorale ed è stata bonificata a partire del 1926 (con una bonifica idraulica); negli anni ’50 l’opera di sistemazione idraulica è continuata con lo scavo del canale est ovest (canale lisert) e con quello del canale tavoloni (1962-1966). l’attuale fronte mare del lisert è stato recentemente definito da un bacino di colmata, delimitato da argini in pietra, che ha inglobato la vecchia isola del balo; questa imponente opera di colmata è attualmente in fase di completamento e servirà ad ampliare le banchine portuali e i servizi retrostanti. il substrato roccioso della piana, costituito dalle rocce affioranti del carso circostante (formazione di monrupino del cenomaniano e calcari di aurisina del turoniano senoniano inf., tentor et al., 1994) è disarticolato da una serie di depressioni sepolte dalla sedimentazione recente. la prima di queste depressioni si ubica a nord nel “solco di moschenizze”, presenta direzione nw se e termina con una soglia posta a -15 m fig. 1 inquadramento geologico e ubicazione dei sondaggi. geological map and location of the studied cores. quota piano fine campagna profondità sondaggio coordinate (rispetto al del (rispetto al (carta tecnica regionale) l.m.m) sondaggio l.m.m) sondaggi 2005 s1 3,08 9,4 -6,32 2408688 x; 5071987 y s2 4,78 12,0 -7,22 2408620 x; 5072076 y s4 3,04 10,0 -6,96 2408425 x; 5072195 y s5 4,87 15,0 -10,13 2408521 x; 5072195 y sondaggio 2004 a 3,56 6,4 -2,84 2408541 x; 5072025 y sondaggi 1995 sm1 4,00 6,0 -2,00 2408868 x; 5071738 y sm2 3,90 15,0 -11,20 2408880 x; 5071477 y tab. 1 sondaggi del lisert: quota, profondità di penetrazione e coordinate gauss – boaga. lisert borings: height, depth of penetration and coordinated gauss – boaga. dal piano campagna, confluendo poi nella vasta area depressionale che si estende dall’attuale cartiera del timavo al sottosuolo del canale lisert (-20 /30 m dal p.c.). a sw una seconda depressione trova origine dalle sorgenti del timavo e si approfondisce notevolmente arrivando a profondità superiori di 65 m sotto l’attuale canale d’entrata alle sorgenti del timavo e al canale locovaz. tra queste due avvallamenti il substrato calcareo risale rapidamente, con irregolarità determinate da locali fratture tettoniche, fino ad arrivare alla culminazione dei due dossi sbancati e tagliati da una ulteriore frattura tettonica a direzione n s. il passaggio tra la roccia carbonatica del substrato e i depositi di riempimento è costituito da un’intercapedine di roccia più o meno alterata, come riportato da st a c u l ( 1 9 9 5 9 6 ) . sotto i l profi lo l itologico la formazione di monrupino, che si ubica a nord dell’area, è costituita da brecce dolomitizzate alla base cui segue un intervallo calcareo-dolomitico chiuso al tetto da banchi sempre più dolomitici. i calcari di aurisina, presenti anche nel versante più orientale del carso isontino, affiorano nei rilievi sbancati del colli di san antonio e di amarina; questi hanno una stratificazione da massiva a ritmica, con strati decimetrici, e presentano una colorazione grigia con abbondanti frammenti di rudiste. la tettonica dell’area (tentor et al., 1994) è estremamente complessa in quanto dominata da strutture dinariche (nw se) rappresentate da un fascio di faglie sub-verticali, talora con evidenze di movimento trascorrente, sulle quali si sono subordinatamente impostate strutture alpine (e w e ne sw). l’attuale piana del lisert era ben nota ai romani per la vicinanza alle celeberrime sorgenti del timavo, decantate da numerosi autori latini e per la presenza delle insulae clarae, ricordate anche da plinio nella naturalis historia (be r t a c c h i, 1979). nell’isola di san antonio (oggi spianata) erano ubicate le terme che utilizzavano l’acqua calda (ca. 40°c) che scaturiva dal sottosuolo. l’impianto termale era molto noto all’epoca romana, tanto da essere ricordato da plinio ”contra timavom amnem insula parva in mari est cum fontibus calidis, qui pariter cum aestu maris crescunt m i n u u n t u r q u e” e riportato nell’importante documento cartografico della tabula peutingeriana (carta del xiii sec., che riproduce una mappa romana del i sec. a.c.; fig. 2). il vasto complesso termale con alterne vicende è rimasto in uso fino a poco tempo fa ed oggi è in fase di ripristino. poco più ad oriente delle terme, sempre alle pendici 159stratigrafia e paleogeografia del “lacus timavi” (friuli ... del colle demolito, era ubicata una estesa villa, con delicati mosaici raffiguranti delfini, fatta risalire dagli archeologi al i sec. d.c. a nord di questo complesso abitativo è stata rinvenuta un’imbarcazione romana oneraria (10,75 m di lunghezza e 3,80 di larghezza) attribuita al ii iii sec. d.c. (be r t a c c h i & be r t a c c h i, 1988), che si appoggiava sulla roccia fratturata del sottofondo calcareo. oltre all’insediamento di san antonio tutto il territorio posto alle prime balze del carso era costellato da ville romane (particolarmente utilizzate dal i sec. a.c. ii sec. d.c.), alcune probabilmente con funzioni m a r i t i m a e, ipotizzate dal rinvenimento di piccoli moli e da impianti per la piscicoltura. queste ville rustiche erano prevalentemente allineate lungo la strada che portava a t e r g e s t e costeggiando le alture carsiche e travalicava il locovaz su un ponte (degrassi & ventura, 1999), probabilmente costruito dalla xiii legion. 3. materiali e metodi sulle carote di terreno ricavate dai sondaggi sono state eseguite analisi granulometriche, micropaleontologiche, archeologiche e radiometriche. tutte le profondità di prelievo dei campioni di sedimento sono state espresse (dopo geo-referenziazione dei sondaggi) in fig. 2 particolare della tabula peutingeriana; la città di aquileia con il fonte timavi e il flumen frigido sono compresi entro il riquadro. detail of the tabula peutingeriana; the city of aquileia with fonte timavi and flumen frigido are within the box. 160 metri dal livello medio mare (l.m.m.) dell’alto adriatico. tutti i dati di profondità di seguito riportati si riferiscono a questo livello (tab. 1). dalle analisi è stato escluso il sondaggio s3 e tutti gli intervalli sommitali dei sondaggi posti al di sopra del l.m.m., in quanto chiaramente costituiti da materiali di riporto. nella descrizione delle carote si sono utilizzati i colori delle tabelle di munsell (1975). i campioni per le analisi granulometriche sono stati prelevati ad ogni variazione tessiturale dei depositi, escludendo quelli legati alle discariche industriali sommitali: complessivamente si sono raccolti 7 campioni per il sondaggio a dell’arpa e 21 per i 5 sondaggi geobasi. le analisi granulometriche sono state condotte con l’analizzatore laser malvern instruments d e l laboratorio di sedimentologia del dipartimento di scienze geologiche, ambientali e marine di trieste su campioni di sedimento tal quale, previa asportazione della frazione più grossolana (> 2 mm), quartatura e attacco con acqua ossigenata per la disgregazione degli agglomerati organici. i caratteri tessiturali dei sedimenti sono stati descritti secondo la classificazione di no t a (1958); i parametri statistici elementari (espressi in φ) sono quelli proposti da fo l k & wa r d (1957). i percentili 1° (c o diametro massimo del sedimento) e 50° (m o mediana del sedimento) sono espressi in micrometri e si riferiscono ai parametri di pa s s e g a (1957; 1964). un’aliquota del sedimento è stata trattata per le analisi paleontologiche, in particolare nella preparazione dei lavaggi non è stata utilizzata acqua ossigenata, per permettere la conservazione ottimale anche dei gusci più delicati. l’analisi delle malacofaune è stata eseguita sulla frazione > 2000 µm di due campioni di sedimento; quella delle microfaune a foraminiferi è stata condotta sulla frazione sabbiosa (2000 ÷ 62,5 µm) di 40 livelli di sedimento campionato. il conteggio è stato eseguito sul totale dei gusci rinvenuti, il numero d’individui per specie è stato quindi normalizzato in percentuale relativa ad ogni livello analizzato. e’ stata calcolata la densità dei gusci tramite il rapporto fra numero di individui e peso di sedimento analizzato, in grammi (individui/g). la dataz ione dei sedimenti torbosi è stata condotta con il metodo del radiocarbonio mediante la tecnica della spettrometria di massa ad alta risoluzione (ams), presso il centro di daazione e diagnostica (cedad) dell’università di lecce. i dati così ottenuti sono stati quindi calibrati in età calendario utilizzando il software oxcal ver. 3.10, basato sui dati atmosferici (reimer et al., 2004). 4. i sondaggi del lacus timavi 4.1 i sondaggi del 1995 questi due sondaggi (sm 1 e sm 2; fig. 1) sono stati prelevati in posizione leggermente meridionale nell’area che separa il rilievo di san antonio da quello di amarina. i dati relativi alla litostratigrafia e alle microfaune ad ostracodi (pugliese n., dati inediti) sono stati qui ripresi e rielaborati in funzione della ricostruzione stratigrafica del territorio. sm 1; questo primo sondaggio è stato eseguito a cavallo tra i rilievi di san antonio e di amarina e si è spinto fino a 6,0 m dal piano campagna (posto a circa 4,0 m dal l.m.m.). ha palesato una situazione molto disturbata dai recenti interventi antropici con i primi 3,0 m di copertura costituiti da materiale di riporto e i rimanenti (da 1,0 a -2,0 m dal l.m.m.) costituiti da ghiaie calcaree, frammiste a peliti, sterili dal punto di vista paleontologico. sm 2; il secondo sondaggio è ubicato a nord del colle di san antonio ad una quota di circa 3,9 m sul l.m.m. e si è fermato alla profondità di 11,2 m (fig. 3). alla base del sondaggio (11,20 10,10 m di profondità) si trova una ghiaia poligenica con matrice sabbioso-pelitica, con ciottoli da millimetrici a centimetrici da arrotondati a sub-arrotondati, incisa da un contatto netto che la mette a contatto con una pelite sabbiosa (10 y 6/1) bioturbata, con scarsi resti organogeni (foraminiferi) e abbondanti frammenti vegetali (profondità da 10,10 a 9,55 m). da 9,55 m a 6,10 m di profondità si rinviene una pelite più o meno sabbiosa (colore da 10 y 3/1 a 4/1); in particolare la sabbia è composta da granuli quarzosi con vari gradi di classazione, da muscovite subordinata e rari cristalli di gesso. la frazione organogena è costituita da frammenti di gasteropodi [bittium reticulatum (da co s t a), c e r i t h i u m s p . , cardidae, veneridae e tellinidae], radioli di echinide, spicole di spugna calcarea e lenticelle carboniose sparfig. 3 lisert: litostratigrafia dei sondaggi e distribuzione dei principali gruppi ecologici rappresentati dai foraminiferi. lisert: litostratigraphy and distribution of the main ecological assemblages represented by the foraminifers. r. marocco & r. melis 161 se. gli ostracodi sono rappresentati da rari esemplari di c a l l i s t o c y t h e r e sp.1, leptocythere bituberculata bo n a d u c e, ci a m p o & ma s o l i, pontocythere turbida (müller), semicytherura incongruens (müller), s. rarecostata bonaduce, ciampo & masoli, s. sulcata (müller), x e s t o l e b e r i s c f . d e c i p i e n s mü l l e r, e al letto da forme alloctone di cyprideis torosa (jo n e s) e p a l m o c o n c h a turbida (müller) (pugliese n., dati inediti). da 6,10 m a 5,10 m di profondità si rinvengono alternanze di pelite sabbiosa (10 y 4/1) e sabbia fina (10y 3/1), mal classata e con granuli di quarzo sub-spigolosi, con frammenti vegetali, nella parte basale, e gasteropodi sia intatti (bittium reticulatum) che in frammenti (c e r i t h i u m s p ., h y d r o b i a sp., e cardiidae). gli ostracodi sono rappresentati da rari individui giovani e alloctoni di cyprideis torosa. dopo 5,10 m di profondità i depositi diventano più sabbiosi con sabbia da fina a media, mal classata, e con granuli di quarzo da subangolosi a sub-arrotondati, che diviene talora pelitica (da 10 y 2/ 2 a 3/1). sono presenti frammenti vegetali (a volte pir it izzati ) e rar i frammenti di cardi idae [cerastoderma glaucum (poiret) a 4,49 m], spicole di spugna silicee (2,90 m) e lenticelle carboniose (da 5,10 a 3,60 m di profondità). seguono (2,10 ÷ 1,53 m di profondità) alternanze centimetriche di pelite (10y 3/1) e sabbia (da 10 y 3/1 a 3/2), con minuti ciottoli sub-arrotondati e frammenti di molluschi indeterminabili e frammenti vegetali, talvolta piritizzati e infine (1,53 ÷ 1,10 m) un livello di pelite (colore da 10 y 3/1 a 2.5 y 3/2), talvolta debolmente sabbiosa e con ciottoli da millimetrici a centimetrici, con abbondanti frammenti vegetali e rarissimi frammenti di gasteropodi continentali. la sequenza viene chiusa da un riporto ghiaioso eterometrico, accumulato in seguito alle intense opere di manomissione del territorio che hanno comportato lo spianamento dei rilievi calcarei (fig. 3). lo studio della microfauna a foraminiferi è stata eseguita su un totale di 15 livelli (da 1,24 a 9,55 m di profondità). sono presenti complessivamente 23 specie appartenenti principalmente al genere a m m o n i a e d elphidium (tab. 2). alla base del sondaggio si osserva una dominanza di ammonia tepida (cushman) con haynesina germanica (ehrenberg), che tendono e diminuire in percentuale verso 6,71 m di profondità, dove a queste si associano a. inflata (seguenza), a. beccarii (linneo) e a. papillosa (d’ or b i g n y), mal conservate ed usurate, e l p h i d i u m spp. e n o n i o n spp. verso metà sondaggio (5,44 m), dopo un livello sterile, si registra la maggior ricchezza specifica, con dominanza di a. tepida e a. inflata e subordinata a. parkinsoniana (d’ or b i g n y). segue un intervallo di alcuni metri (da 4,86 a 2,50 m di profondità) dove non sono presenti microfaune. verso la superficie, si ritrova a. tepida dominante ed infine, nell’intervallo sub-superficiale, miliammina fusca (br a d y) e trochammina inflata (montagu). la densità dei gusci è più elevata nella metà inferiore del sondaggio, dove raggiunge 456,4 ind/g e tende a diminuire decisamente nei livelli superficiali (valore massimo di 1,3 ind/g). a partire dalla base del sondaggio la dominanza di a . t e p i d a, specie eurialina universalmente riconosciuta come tipica di ambienti lagunari (murray, 1991), indica un paleoambiente paralico piuttosto confinato che si evolve verso un minor confinamento nella parte centrale del sondaggio, come testimoniato dalla presenza di a. beccari, a. inflata e a. papillosa, specie che si rinvengono normalmente nell’ambiente infralitorale mediterraneo (ci m e r m a n & la n g e r, 1991; sg a r e l l a & moncharmont zei, 1993; donnici & serandrei barbero, 2002) (fig. 3). l’assenza di microfaune in un intervallo di circa 4 m di sedimento potrebbe essere dovuto ad un trattamento troppo invasivo in fase di preparazione dei campioni , ma potrebbe anche rappresentare un ambiente non idoneo alla presenza di foraminiferi (emersione). la parte sommitale del sondaggio rivela un ambiente impaludato, probabilmente intertidale rappresentato da un elevato accumulo di vegetazione e dalla presenza di taxa tipici di ambienti ad elevata variabilità di salinità, quali stagni, paludi e barene (al b a n i & se r a n d r e i ba r b e r o, 1990; za n i n e t t i; 1992; mu r r a y & alve, 1999) (fig. 3). 4.2 i sondaggi del 2004 dei quattro sondaggi eseguiti nell’anno l’unico studiato integralmente è stato il sondaggio a, effettuato a carotaggio continuo immediatamente a nord dell’impianto delle terme romane di monfalcone, in un area interessata da recenti e antiche discariche. sondaggio a: la parte terminale del sondaggio che ha raggiunto il basamento calcareo (2,84 m dal l.m.m.) si è sfilata dal carotiere e non è stata recuperata. quella immediatamente soprastante è costituita da un livello di pelite grigia (da 2,44 a 2,34 m) che diviene sabbiosa, con frammenti di conchiglie e resti vegetali (da 2,34 a 2,04 m) (fig. 3). segue un intervallo (da -2,04 a 0,49 m) di pelite molto sabbiosa, grigia scura, con frammenti di intonaco, di cotto, ceramiche e ciottoli sub-angolosi. da 0,49 a 0,14 m è presente un livello di torba, definito da un contatto netto alla base e graduale al top, con all’interno lamine di sabbia medio fina, chiara. la torba è contraddistinta da resti vegetali, alcuni indecomposti, di probabile fragmiteto contenente pezzi di coccio, vetri, ceramiche e pezzi d’intonaco (antica discarica di materiale romano, difficilmente collocabile in una scala cronologica più precisa). segue un orizzonte francamente pelitico-sabbioso con un livelletto (3 cm) di sabbia fina grigio-chiara (da 0,14 a 0,34 m) e viene chiuso dall’ultimo livello naturale (da 0,34 a 0,66 m) di pelite molto sabbiosa (contenuto in sabbia: 64%), di color grigio. la coltre di materiali eterometrici di discarica industriale recente (dal top alla profondità di 0,66 m dal l.m.m.) è costituita da limi con sabbia, ghiaia e variegati materiali di riporto. le analisi granulometriche condotte sui sedimenti mostrano mediamente una dimensione dei diametri tra le sabbie fini e il silt grossolano, un cattivo assortimento dei clasti e un trasporto per sospensione gradata/saltazione per i campioni più superficiali (gruppo i) e per sospensione uniforme/decantazione per i rimanenti (gruppo ii) (fig. 4). prendendo in considerazione i principali parametri statistici dei sedimenti (mz e sorting) e confrontandoli con quelli dei depositi attuali e subattuali del friuli venezia giulia (di ambiente continentale -fluviale, di ambiente litorale e, infine, lagunare di fig. 5) emerge che i depositi del sondaggio a si posizionano al limite dei depositi litorali più profondi (8 10 m) e assumono valori più prossimi a quelli dei sedimenti di piana alluvionale (distale) rispetto a quelli di laguna. lo studio micropaleontologico è stato eseguito su tre livelli (da 0,24 a 1,94 m di profondità) (tab. 2). dalla stratigrafia e paleogeografia del “lacus timavi” (friuli ... 162 base del sondaggio si osserva un ambiente paralico piuttosto confinato, rappresentato dalla dominanza di a . tepida, h. germanica e nonion pauciloc u l u m cu s h m a n, che tende all’impaludamento nel livello sub-superficiale. a 0,24 m di profondità, infatti, sono presenti numerosi individui di h a p l ophragmoides manilaensis andersen, h. c f . w i l b e r t i an d e r s e n e j a d a m m i n a m a c r e s c e n s (br a d y), tipici di ambienti vegetati (m a r s h) (za n i n e t t i; 1992; mu r r a y & al v e, 1999; ho r t o n & murray, 2006) (figg. 3 e 6). 4.3 i sondaggi del 2005 la serie di sondaggi eseguita recentemente mostra, dopo una coltre di materiale eterometrico di discarica (di potenza variabile da 3 a 5 m), una sequenze fining-upward che si compone, generalmente, di un intervallo pelitico molto sabbioso con diffusi frammenti conchigliari che passa ad un intervallo di pel it i sabbiose, con sostanza organica e frequenti fibre vegetali (fig. 3; s1, s4 e s5). questa sequenza manca nel sondaggio s3, dove le discariche poggiano direttamente sul capello di alterazione dei calcari del basamento e nel sondaggio s2, dove viene a mancare l’orizzonte pelitico sabbioso più superficiale e l’intero sondaggio si mantiene nell’ambito del mescolamento paritetico di sabbie e peliti. il basamento carbonatico si incontra nei sondaggi s1, s3 e s4, rispettivamente alle profondità di 5,0; 0,2 e 6,7 m dal l.m.m. ed è coperto da un capello di alterazione con roccia fratturata e ciottoli calcarei parzialmente calcificati. la frazione conchigliare, particolarmente evidente alla base dei sondaggi s2 (6,38 ÷ 6,35 m di profondità) e s4 (6,52 ÷ 6,50 m di profondità) mostra la presenza nel primo sondaggio di gibbula albida (gm e l i n), frammenti di cerastoderma glaucum e r i s s o a sp. (probabilmente r. pulchella ph i l i p p i) e nel secondo, frammenti di cerastoderma glaucum, cerithium vulg a t u m br u g u i è r e, chamelea gallina (li n n e o), gibbula albida, jujubinus s p . , paphia aurea (gmelin) e tricolia sp. (vio e., comunicazione personale). in sintesi, si tratta di specie litorali-paraliche, presenti in sabbie inframmiste a pelite, tipiche di un ambiente deltizio-lagunare (cerastoderma glaucum e gibbula albida), vegetato da fanerogame marine (alghe fotofile jujubinus sp.) e con un relativo ridotto idrodinamismo (cerithium vulgatum e paphia aurea). da un punto di vista tessiturale tutti i depositi indagati manifestano caratteri più intermedi tra i depositi lagunari di retro bocca e quelli di alluvionamento delle basse pianure costiere veneto-friulane (fig. 5). segnatamente, rispetto al sondaggio a, i depositi di questi sondaggi sono abbastanza simili a quelli che nella laguna di grado (ma anche di marano e di carole) si ubicano nelle piane di marea immediatamente alle spalle delle bocche lagunari, nell’area di commistione tra i depositi litorali e quelli prettamente lagunari (area ii e iii di gu e l o r g e t & pe r t h u i s o t, 1983). la modalità di trasporfig. 4 modalità di trasporto dei sedimenti distinti per sondaggio. i gruppi i e ii racchiudono rispettivamente i depositi che si muovono per saltazione sospensione gradata e per sospensione uniforme decantazione. mode of sediments transport, separated per survey. the groups i and ii contain deposits that are moving by saltation graded suspension and by uniform suspension decantation, respectively. fig. 5 diagramma mz sorting con i campi dei depositi fluviali (alveo e piana alluvionale), quelli litorali (emersi e sommersi) e lagunari del settore orientale della costa del friuli venezia giulia (da marocco et al., 2005, modificato e integrato con i risultati di lavori precedenti). mz sorting diagram showing the fields of the fluvial (alluvial plain and river bed), litoral (emerged and submerged) and lagoon deposits of the western sector of the friuli venezia giulia coast (after marocco et al., 2005, modified and supplemented with the results of previous work). r. marocco & r. melis to dei sedimenti più sabbiosi basali risulta essere per sospensione uniforme (gruppo i), mentre quella dei sedimenti più superficiali per decantazione (gruppo ii di fig. 4). l’età radiocarbonio eseguita per scarsità di materiale organogeno databile sui soli sedimenti torbosi dei sondaggi s4 e s5 è di 6182 ± 60 anni 14 c b.p. (s4; -6,51 m) e di 5431 ± 55 anni 1 4 c b.p. (s5; 9,28 m) con valori di δ 13 c (‰), rispettivamente di -31,6 ± 0,2 e di 22,1 ± 0,5. data l’incongruenza tra età e profondità dei campioni nei due sondaggi si è ritenuta valida la sola datazione del sondaggio s5 per il valore normale di δ 13 c (‰) che ricade nell’intervallo ritenuto standard per questi depositi (-25 ± 3 ‰). la calibrazione di questa età porta ad una data di 4370 ÷ 4220 anni a.c. (80,3 %) (tab. 3). l’analisi micropaleontologica dei foraminiferi rinvenuti nei sondaggi ha fornito le seguenti indicazioni: s1: in questo sondaggio, posizionato a ridosso settentrionale delle insulae clarae s o n o stati studiati tre livelli (profondità da 3,32 a 0,62 m). le faune a foraminiferi sono rappresentate da un limitato numero di specie (8) e da una densità dei gusci inferiore a 20 individui/g. dalla base verso il tetto si passa da un ambiente parlico intertidalesubtidale caratterizzato da scarsissima presenza di a m m oscalaria ruinana, ad un ambiente paralico con dominante a mmonia tepida e subordinata haynesina germanica; nel livello superficiale si assiste alla comparsa di h a p l o p h r a g m o i d e s manilaensis e h. cf. wilberti, che indicano una tendenza all’impaludamento del paleoambiente (tab. 2). s 2 : in questo s o n d a g g i o ubicato in un settore più settentrionale rispetto il precedente, si rinviene una maggior ricchezza specifica, con un totale di 18 specie, ed un valore di individui/g più elevato rispettivamente alla base e al tetto della carota. sono stati studiati cinque livelli (profondità da 6,35 a 0,55 m sul l.m.m.). partendo dalla base della carota si rinviene un intervallo caratter izzato da dominanza di a. tepida e subordinata a. inflata, cui si associano a taxa marini infralitorali quali a. parkinsoniana, elphidium spp. e nonion spp. (tab. 2). il paleoambiente evolve verso un livello costituito da dominanza assoluta di a. runiana (fig. 6) associata ad pochi individui di a. tepida. la specie dominante di questo livello è segnala163 fig. 6 microfotografie al sem di alcuni foraminiferi rappresentativi del paleoambiente indagato nei sondaggi (la lunghezza della barra rappresenta 30 µm): 1 ammoscalaria runiana, veduta laterale; 2 a. runiana, veduta laterale; 3 a. runiana, veduta obliqua; 4 j a d a m m i n a m a c r e s c e n s, veduta ombelicale; 5 haplophragmoides canariensis, veduta laterale; 6 haplophragmoides manilaensis, veduta laterale; 7 h a p l o p h r a g m o i d e s c f . w i l b e r t i, veduta laterale; 8 miliammina fusca, veduta laterale; 9 elphidium excavatum clavatum, veduta laterale; 10 nonion depressulum, veduta laterale; 11 haynesina germanica, veduta laterale; 12 elphidium complanatum, veduta laterale; 13 elphidium excavatum lidoense, veduta laterale; 14 elphidium poeyanum, veduta laterale; 15 elphidium pulvereum, veduta laterale; 16 cribrononion simplex, veduta laterale. sem micrographs of some foraminifer species representative of the environments recorded in the samples (magnification: bar = 30 µm): 1 ammoscalaria runiana, side view; 2 a. runiana, side view; 3 a. runiana, oblique view; 4 jadammina macrescens, umbilical side; 5 haplophragmoides canariensis, side view; 6 haplophragmoides manilaensis, side view; 7 haplophragmoides cf. wilberti, side view; 8 miliammina fusca, chamber view; 9 elphidium excavatum clavatum, side view; 10 nonion depressulum, side view; 11 haynesina germanica, side view; 12 elphidium complanatum, side view; 13 elphidium excavatum lidoense, side view; 14 elphidium poeyanum, side view; 15 elphidium pulvereum, side view; 16 cribrononion simplex, side view. stratigrafia e paleogeografia del “lacus timavi” (friuli ... 164 r. marocco & r. melis 165stratigrafia e paleogeografia del “lacus timavi” (friuli ... ta come specie intert i d a l e s u b t i d a l e (murray, 1991), e più precisamente in ambienti di mud flat d i estuari, fiordi e lagune del mar baltico (al v e & mu r r a y; 1999; fr e n z e l et al., 2005), la sua elevata presenza in questo livello potrebbe comunque essere dovuta anche a fattori tafonomici. in ambienti costieri vegetati, infatti, i bassi valori di ph creano le condizioni per elevati fenomeni di dissoluzione dei gusci carbonatici, come evidenziato ad esempio da gr e e n et. al. (1993); murray & alve (1999); culvert & horton (2005); ho r t o n & mu r r a y (2006). segue un intervallo paralico più o meno confinato, dove si notano alcuni individui di h. canariensis (d’ or b i g n y), al quale si associano taxa tipici di ambienti stagnali verso la superficie del sondaggio. s4: i l sondaggio è posizionato analogamente a settentrione delle insulae clarae; sono stati studiati sette livelli (profondità da 6,50 a 0,54 m sul l.m.m.). la fauna a foraminiferi presenta complessivamente la maggior ricchezza specifica con 27 taxa, mentre la densità dei gusci si attesta su valori più elevati alla base e al tetto (da 43,0 a 253,2 ind/g) e valori più scarsi, inferiori a 15,0 individui/g, nella parte centrale della carota. alla base si presenta un intervallo dominato da ammonia spp. e subordinati elphidium spp., haynesina germanica e nonion spp. (fig. 6). nell’insieme l’ambiente può essere considerato come paralico poco confinato. segue un livello dove a. runiana raggiunge valori dominanti (> 80,0%), similmente alla parte centrale del sondaggio s2. successivamente l’associazione si arricchisce di a. tepida, che diventa la specie dominante, tranne nel livello sub-superficiale, dove viceversa la riduzione di questo taxon è seguita dall’importante presenza di quelli tipici di ambienti stagnali fortemente vegetati. nel livello superficiale si ritorna da una situazione di maggior apertura verso l’ambiente paralico mediamente confinato (fig. 3). s5: in questo sondaggio, collocato anch’esso a settentrione delle insulae clarae sono stati studiati sei livelli (profondità da 9,27 a 0,43 m dal l.m.m.). nel complesso si assiste ad una diminuzione della ricchezza dei foraminiferi rispetto ad agli altri sondaggi, che complessivamente sono presenti con 16 specie. la densità dei gusci si attesta su tenori variabili attorno a 20 individui/g, tranne che nel livello medio dove tale valore arriva a 148,4 individui/g. alla base della carota si trova un intervallo ad a. tepida e a. inflata dominanti, cui si associano e l p h i d i u m spp. e nonion depressulum (wa l k e r & ja c o b), l’associazione rappresenta un ambiente paralico poco confinato. a metà carota si rinviene un livello ad prevalente a. inflata e ammoscalaria runiana, a bassa densità dei gusci, che rappresenta un ambiente di mud-flat scarsamente vegetato. nella parte superiore del sondaggio l’ambiente evolve verso un maggior confinamento che porta probabilmente ad una situazione di palude vegetata, come rappresentato dal la dominanza di a. tepida , cui si associano haplophragmoides manilaensis e h. cf. wilberti (tab. 2; fig. 3). 5. discussione e considerazioni conclusive l’analisi della litostratigrafia e delle mesoe micro-faune a foraminiferi ed ostracodi eseguite sul primo sondaggio sm2, la più meridionale delle terebrazioni analizzate, hanno evidenziato la presenza di un ambiente fluviale basale su cui si imposta un ambiente paralico di acque poco profonde (fino a 6,10 m di profondità), influenzato in maniera variabile da apporti di acque dolci e/o marine. il rinvenimento di frequenti frammenti vegetali piritizzati porta a supporre che in questo ambiente si instaurasse a volte condizioni di scarso idrodinamismo, fino alla stagnazione delle acque. nel suddetto intervallo i caratteri più marino-litorali vengono riconosciuti nei soli livelli posti in corrispondenza di 7,90 e 6,19 m, dove sono presenti forme costiere, probabilmente trasportate. segue un intervallo (da 6,10 a 2,53 m) contraddistinto da una scarsa presenza di forme (esclusivamente rari o rarissimi foraminiferi da 6,10 a 5,20 m di profondità) e quindi una assenza totale di foraminiferi ed ostracodi (segnalata dai campioni di sedimento posti da 4,84 a 2,53 m). la presenza di un deposito di sabbia grossolana mal classata, e commista a pelite, con frammenti di vegetali e gasteropodi, mal conservati, porta a ritenere che si tratti di un deposito di una piana fluviale superiore, alimentata da un fiume che sfociava ad ovest, a breve distanza dalle insulae clarae. la sequenza viene chiusa da un ambiente dappria paralico, poi acquitrinoso sommitale (da 2,1 a 1,1 m dal l.m.m.), rappresentato da scarsi foraminiferi a guscio aglutinante. in sintesi, i depositi e le microfaune rinvenute immediatamente a nord dei rilievi calcarei delle insulae clarae definiscono una sequenza sedimentaria costituita da una fase trasgressiva che ha visto una paleolaguna occupare parte della pianura pleistocenica ed assumere caratteri sempre più marini fino a raggiungere il culmine in corrispondenza della profondità di 7,9 7,7 m. dopo questa profondità si registra una inversione di tendenza che porta alla formazione di un ambiente paralico sempre più interno, fino all’emersione determinata dall’accumulo di depositi di piana fluviale. la sequenza viene chiusa da un ulteriore ambiente lagunare che rapidamente si trasforma negli acquitrini che si rinvengono sotto l’attuale piano campagna. negli altri sondaggi, compreso il sondaggio a del 2004, si riscontrano condizioni paraliche che sfumano verso il tetto a condizioni di stagno costiero (m a r s h) , 166 età sigla campione profondità materiale radiometrica δ13c (c ‰) data a.c. laboratorio sondaggio (m dal l.m.m.) datato (b.p.) (probabilità %) ltl2082a lisert s4 6,51 torba 6182 ± 60 31,6 ± 0,2 5310 4999 (95,4%) ltl2083a lisert s5 9,28 torba 5431 ± 55 22,1 ± 0,5 4370 4220 (80,3%) tab. 3 datazioni con il radiocarbonio ed età calibrata per i sondaggi s4 e s5 (lisert). radiocarbon ages and calibrated date for the s4 and s5 cores (lisert area). r. marocco & r. melis molto prossime alle recenti condizioni del lisert, prima delle bonifiche. quasi sempre al letto dei depositi le condizioni paraliche sono determinate da un’associazione mista di taxa marini e paralici con una leggera alternanza di valori attorno al 50% in s4 e s5 e una prevalenza dei secondi sui primi nei sondaggi a, s1 e s2. in queste sequenze sembra assumere particolare rilevanza la presenza di ammoscalaria runiana che si rinviene quasi in forma esclusiva nei sondaggi s5 alla profondità di 5,1, in s4 a 4,5 m, in s2 a 3,3 m e in s1 a 3,3 m, in coincidenza con l’emersione del litorale meridionale delle insulae clarae, rappresentata dai sedimenti nel sondaggio m2/95. questo foraminifero agglutinante è stato segnalato ed analizzato soprattutto nei mari del nord europa dove si è insediato recentemente (se i d e n k r a n t z & kn u d s e n, 1993), sostituendo la forma olocenica boreale di ammoscalaria pseudospiralis (williamson) e non è stato rinvenuto fino ad oggi in alto adriatico nelle aree costiere del mediterraneo. la sua presenza nel lacus timavi a diverse profondità in sondaggi molto prossimi tra loro, sembra definire una particolare condizione ambientale raggiunta probabilmente in tempi successivi nei diversi sondaggi. di certo questa forma si è insediata in alto adriatico ben dopo l’età di 4370 ÷ 4220 a.c., calcolata sulla torba posta a 9,28 m di profondità. per cercare eventuali analogie e possibili correlazioni delle sequenze trasgressive e regressive parziali, individuate nel solo sondaggio m2 del lisert, o con la relativa stabilità nell’ambito di un sistema paralico confinato come negli altri sondaggi indagati, si sono messi a confronto i trends di altre sequenze analizzate in aree prossimali. per prima si è presa in considerazione la sequenza stratigrafica individuata più ad ovest nel sottosuolo dell’isola di grado (marocco et al., 2005). qui si è registrato un motivo stratigrafico determinato da un emiciclo trasgressivo-regressivo che si è attuato in ambiente marino poco profondo. recenti datazioni 14 c eseguite dagli autori su due livelli di conchiglie del sondaggio dell’isola di grado, hanno evidenziato età di 405 ÷ 355 a.c. a 3,20 m di profondità e di 5497 ÷ 5380 a.c. a 8,10 m di profondità. dal confronto, emerge che depositi di ambiente diverso e di età differente si trovano alla stessa profondità (8,10 m/ 5497 ÷ 5380 a.c. a grado e 9,28 m/ 4370 ÷ 4220 a.c. sul lisert); non solo, ma mentre il sondaggio del lisert mostra chiaramente una fase trasgressiva basale e una successiva fase regressiva che porta all’emersione dell’area costiera, quella del sottosuolo di grado palesa solamente leggere fluttuazioni nell’ambito del sistema litorale marino, che giunge ad una fase regressiva solamente nel tratto finale con la formazione di un ambiente lagunare, come avviene anche nel sondaggio del lisert determinata però da una fase trasgressiva. per quanto attiene ai sondaggi più interni del lisert messi a confronto con i depositi lagunari di marano (marocco, 1989; 1991) e di carole (marocco et al., 1996; galassi & marocco, 1999) non si intravedono analogie sequenziali in quanto i primi sono caratterizzati da una certa continuità di sedimentazione nell’ambito del sistema lagunare interno chiusa solamente al top da un impaludamento, mentre gli altri sono definiti da un ciclo trasgressivo continuo, che si esplica nell’ambito di un sistema lagunare e porta via, via, a depositi progressivamente più vicini al margine interno della laguna. in ogni caso i depositi paralici datati all’interno del lisert si allineano con tutti gli analoghi depositi nell’area costiera veneto friulana (da ma r o c c o 1989; 1991; ma r o c c o et al., 1996; ga l a s s i & ma r o c c o, 1 9 9 9 ; fo n t a n a, 2006) e trovano riscontro con altre testimonianze datate nel golfo di trieste (an t o n i o l i et al. , 2007). segnatamente questi depositi si collocano in posizioni più basse rispetto al modello teorico glacioeustatico di variazione del livello relativo del medio mare riportato dagli stessi autori (fig. 7). i dati ottenuti dall’analisi delle sequenze sedimentarie del sottosuolo del lisert permettono ora di definire con una certa precisione l’evoluzione paleogeografia del settore più meridionale del territorio a partire da 10 m di profondità rispetto il l.m.m. (fig. 8). scenario b (periodo atlantico). facendo riferimento alle profondità di 9 ÷ 10 m dal l.m.m. il territorio dell’attuale lisert era ricoperto da una ampia laguna che inglobava le insulae clarae e si estendeva a nord delle stesse per alcuni chilometri. all’interno della laguna le acque ricoprivano la parte centrale del bacino (sondaggio s5) e si estendevano molto più a nord dell’area indagata, andando a lambire le balze del carso. nell’area rappresentata da tutti gli altri sondaggi studiati affiorava la roccia calcarea. l’estesa paleolaguna comunicava con il mare aperto attraverso il profondo canale del locovaz-timavo e beneficiava delle acque dal solco di moschenizza a nord e del timavo ad est. scenario c (periodo sub boreale). alla profondità di circa 5 ÷ 6 m dal l.m.m. il sottosuolo palesa una evidente riduzione del bacino lagunare di fronte alle insulae clarae, che progressivamente assume le carat167 fig. 7 curva isostatica teorica per il golfo di trieste (da antonioli et al., 2007; modificata) e area che racchiude i depositi paralici (età b.p.) della costa veneto-friulana (da marocco, 1989; 1991; ma r o c c o et al; 1996; ga l a s s i & ma r o c c o 1 9 9 9 ; fo n t a n a, 2006). il deposito del lisert è visualizzato con un triangolino. isostatic theoretical curve for the gulf of trieste (from antonioli et al., 2007, modified) and area that includes paralic deposits (age b.p.) of the venetian-friulian coast (after marocco, 1989; 1991; marocco et al.; 1996; galassi & marocco 1999; fontana, 2006). the lisert deposit is shown with a triangle. stratigrafia e paleogeografia del “lacus timavi” (friuli ... teristiche di un area emersa, alimentata da apporti solidi fluviali provenienti da ovest. nel contempo si assiste ad un ampliamento del bacino lagunare interno che si espande progressivamente e va ad interessare gran parte dell’area dove sono ubicati tutti i sondaggi indagati ad eccezione di quella relativa a s1. alla profondità di circa 4 m dal l.m.m. continua l’emersione del l’area immediatamente a nord dei rilievi calcarei delle insulae e si riduce progressivamente il bacino lagunare interno dove verso i margini si manifesta la quasi esclusiva presenza di ammoscalaria runiana. scenario d (periodo sub atlantico epoca romana). quest’ultimo scenario è reso più semplice, grazie alle notevoli informazioni acquisite dallo studio archeologico di numerose località indagate. alla profondità di 2÷1 m dal l.m.m. l’ambiente paralico lagunare si estende in parte anche a nord dei rilievi delle isole e si amplia all’interno lambendo anche le propaggini nord delle stesse. e’ probabile che in questo periodo un ramo del fiume s o n t i u s (isonzo) lambisse il lato ovest dell’area e che avesse la foce in quelle località. una serie di dati geomorfologici (carta geo cgt della regione friuli venezia giulia fogl io grado/sezione monfalcone; ma r o c c o, 2008) e nuovi studi archeologici raccolti da una recente ricerca sul ponte romano di ronchi dei legionari (zanier, 2009) portano a queste ipotesi. di certo il sistema lagunare che si stava progressivamente impaludando ospitava ai suoi margini ville e terme romane, approdi e imbarcazioni di notevole stazza (degrassi & ve n t u r a, 2001; au r i e m m a, 2007; au r i e m m a et al. , 2007). questa ricostruzione paleogeografia dell’area del lacus timavi nell’olocene perfeziona tutte le ricostruzioni della linea di costa fino ad oggi presentate (a partire da ma r o c c o 1991; bo s c h i a n 1993; ma r o c c o et al. , 2005; fino a benjamin & bonsall, 2009 e antonioli et al., 2009) e mette in evidenza la presenza e la persistenza di un bacino paralico posto a ridosso delle sorgenti del timavo, in un’area profondamente incisa dalla tettonica locale. interessanti collegamenti tra questo bacino confinato e il mare aperto e soprattutto una migliore definizione delle linee di costa oloceniche e della paleogeografia dell’area potranno attendersi dal confronto tra le associazioni microfaunistiche rinvenute nel lisert con quelle riscontrate in tre sondaggi del golfo di trieste (co v e l l i et al., 2006), il cui studio è previsto per un prossimo futuro (me l i s, progetto ateneo di trieste 2008). l’unico dato radiometrico ritenuto attendibile inerente i depositi paralici del lisert rientra, come detto, nell’ampio intervallo di variazione dei valori profondità età dei depositi tidali della costa veneto-friulana. tutti questi dati, ovviamente, si posizionano ad un livello più basso rispetto alle curve teoriche glacio-eustatiche m 2 e m 3 di antonioli et al. (2007) e si collocano sui livelli riscontrati nel golfo di trieste che sono più bassi delle curve teoriche di ca. 1 m (a 2000 anni b.p.). rispetto a questi, comunque, il dato raccolto sul lisert risulta in linea con quelli degli analoghi depositi delle vicine lagune di caorle e di marano (e più bassi di altri inerenti 168 fig. 8 possibili scenari paleogeografici del lacus timavi: a) situazione attuale b) periodo atlantico c) periodo sub boreale d) periodo sub atlantico epoca romana. possible paleogeographic scenarios of lacus timavi: a) present situation b) atlantic period c) sub boreal period d) sub atlantic period roman period. r. marocco & r. melis le stesse lagune). e’ chiaro che questo è troppo poco per affermare che in quest’area la componente glacioeustatica e tettonica si sia sommata a quella della subsidenza naturale per condizionare l’evoluzione della zona costiera monfalconese come evidenziato da lambeck et al. (2004); ferranti et al. (2006). l’unicità del dato radiometrico, la variabilità nella profondità dei depositi tidali rispetto al livello marino non permettono, a nostro avviso, di calcolare con precisione il tasso tettonico nell’area come fatto a scala regionale dagli autori su riportati. appare però opportuno rilevare che una certa attività tettonica ha interessato ed interessa l’area del lisert, come anche dimostrato da livellazioni recenti della costa del carso triestino (livellazioni i.g.m. recenti linea cj in antonioli et al., 2009) dove si riscontra un picco di abbassamento del suolo nei pressi di duino (< di 1 mm/anno; braitember c., comm. personale) imputabile a cause tettoniche locali. in estrema sintesi, questo unico dato raccolto sulla profondità età dei depositi lagunari del lisert a nostro avviso deve essere considerato solamente come un indizio, che si spera in un prossimo futuro venga confermato e confortato da dati più significativi sui movimenti verticali del suolo che hanno interessato e che interessano il lacus timavi nel lasso di tempo qui indagato. ringraziamenti gli autori desiderano ringraziare la dott.ssa franca maselli scotti della locale soprintendenza, il consorzio per lo sviluppo industriale del comune di monfalcone nelle persone del direttore dott. gianpaolo fontana, della dott.ssa francesca goriup e della dott.ssa chiara boscarol, per aver reso possibile questa ricerca. un ringraziamento particolare al prof. nevio pugliese e alla dott.ssa maria eugenia montenegro del disgam che hanno reso disponibili i dati dei sondaggi sm 1 e sm 2 e un vivo ringraziamento al collega ennio vio (dipartimento di biologia dell’università di trieste) per la determinazione delle malacofaune. la ricerca è stata condotta con finanziamento del progetto di ateneo “evoluzione paleoambientale olocenica della zona costiera compresa fra i meridiani aquileia-grado e trieste (adriatico settentrionale)”, coordinato da r. melis. lavori citati al b a n i a.d. & se r a n d r e i b a r b e r o r. (1990) i foraminiferi della laguna e del golfo di venezia. mem. sc. geol., xlii, 271-341. al v e e. & mu r r a y j.w. (1999) marginal marine environments of the skagerrak and kattegat: a vaseline study of living (stained) benthic foraminiferal e c o l o g y. palaeogeogr., palaeoclimatol. , palaeoecol., 146, 171-193. antonioli f., anzidei m., lambeck k., auriemma r., gaddi d., fu r l a n i s., or r u’ p., so l i n a s e., ga s p a r i a . , ka r i n j a s., ko v a ã i ã v. & su r a c e l. (2007) s e a level change during the holocene in sardinia and in the northeastern adriatic (central mediterranean sea) from archaeological and geomorphological data. quat. sci. rev., 26, 2463-2486. an t o n i o l i f., fe r r a n t i. l., fo n t a n a a., am o r o s i a . m . , bondesan a., braitenberg c., dutton a., fontolan g., fu r l a n i s., la m b e c k k., ma s t r o n u z z i g . , mo n a c o c., sp a d a g. & st o c c h i p. (2 0 0 9 ) holocene relative sea-level changes and vertical movements along the italian and istrian coastlines. quat. intern., 206 (1-2), 103-133. auriemma r. (2007) le strutture portuali minori dell’alto adriatico. atti x x x v i i settimana di studi aquileiesi. auriemma r., degrassi v., gaddi d., mauro s., oriolo f. & riccobono d. (2007) terre di mare: paesaggi costieri dal timavo alla penisola muggesana. terre di mare. l’archeologia dei paesaggi costieri e le variazioni climaticheil progetto interreg italia – slovenija “altoadriatico”, 75 – 211. benjamin j. & bonsall c. (2009) a feasibility study for the investigation of submerged sites along the coast of slovenia. international jour. of naut. archaeol., 10, 1-10. be r t a c c h i l . (1979) presenze archeologiche romane nell’area meridionale del territorio di aquileia. ant. alt. adriatiche, xv, 259-289. be r t a c c h i l. & be r t a c c h i p. (1988) l ’ i m b a r c a z i o n e romana di monfalcone. chimica del friuli, 71 pp. boschian g. (1993) continental deposits and archaeological data in the trieste karst (ne i taly). evidence of sea-level changes and possibile tectonic activity in late pleistocene and early holocene. geol. rundschau, 82, 227 – 233. ca r t a g e o-c g t d e l l a r e g i o n e d e l f r i u l i v e n e z i a g i u l i a (2008) foglio grado. ci m e r m a n f. & la n g e r m.r. (1991) m e d i t e r r a n e a n f o r a m i n i f e r a. slovenska akademija znanosti in umetnosti. opera academia scientiarium et artium slovenica., classis 4, historia naturalis, 30, 118 pp. covelli s., fontolan g., faganeli j. & ogrinc n. (2006) anthropogenic markers in the holocene stratigraphic sequence of the gulf of trieste (northern adriatic sea). marine geol., 230, 29-51. cu l v e r t s.j. & ho r t o n b.p. (2005) i n f a u n a l foraminifera from the outer banks, north carolina, usa. jour. foram. res., 35, 148-170. degrassi v. & ventura p. (1999) ricerche nell’area del lacus timavi: la rete stradale nelle fonti archivistiche. ant. alt. adriatiche, xlv, 125-145. de g r a s s i v. & ve n t u r a p. (2001) le ville del lacus timavi, “tempus edax rerum”, roma ed il timavo; appunti di ricerca. gruppo speleologico flondar, 29-62. donnici s. & serandrei barbero r. (2002) the benthic foraminiferal communities of the northern adriatic continental shelf. mar. micropal., 44 (3-4), 93-123. ferranti l., antonioli f., mauz b., amorosi a., dai prà g., ma s t r o n u z z i g., mo n a c o c., or r ù p . , pa p p a l a r d o m., ra d k e u., re n d a p., ro m a n o p . , sansò p. & verrubbi v. (2006) marker of the last interglacial sea-level high stand along the coast of italy: tectonic impl ications. quaternary international, 145 -146, 30 -54. fo l k r.l. & wa r d w.c. (1957) brazos river bar: a story in the significance of the grain size parame169stratigrafia e paleogeografia del “lacus timavi” (friuli ... ters. jour. sed. petrol., 43, 224-237. fo n t a n a a. (2006) evoluzione geomorfologica della bassa pianura friulana e sue relazioni con le dinamiche insediative antiche. pubbl 47, gortania, museo friulano di storia naturale, 287 pp. fr e n z e l p., te c h t.& ba r t h o l d y j. (2005) c h e c k l i s t and annotated bibl iography of recent foraminiferida from german baltic sea coast. studia geologica polonica, 124, 67-86. galassi p. & marocco r. (1999) relative sea-level rise, sediment accumulation and subsidence in the caorle lagoon (northern adriatic sea, italy) during the holocene. il quaternario, 12(2), 249-256. green m.a., aller r.c. & aller j.y. (1993) carbonate dissolution and temporal abundances of foraminifera in long island sound sediments. limnol. and oceanogr., 38, 331-345. gu e l o r g e t o. & pe r t h u i s o t j.p. (1983) le domaine paralique. expressions géologiques, biologiques et économiques du confinement. travaux du laboratoire de géologie, ecole normale supérieure paris, 16, 1-136. horton b.p. & murray j.w. (2006) patterns in cumulative increase in live and dead species from foraminiferal time series of cowpen marsh, tees estuary, uk: implication for sea-level studies. mar. micropal., 58, 287-315. lambeck k., antonioli f., purcell a. & silenti s. (2004) sea level change along the italian coast for the past 10,000 yr quaternary science reviews, 2 3, 1567 1598. marocco r. (1989) evoluzione quaternaria della laguna di marano (friuli venezia giulia). il quaternario, 2, 125-137. marocco r. (1991) evoluzione tardopleistocenica-olocenica del delta del f. tagliamento e delle lagune di marano e grado (golfo di tr ieste) . i l quaternario, 4, 223-232. marocco r. (2008) la villa di ronchi nell’ambito della geologia della piana isontina. in “luoghi di vita rurale. un percorso che attraversa i secoli”. comune di ronchi, 9-13 pp. ma r o c c o r., me l i s r., mo n t e n e g r o m.e., pu g l i e s e n . , vi o e. & le n a r d o n g . (1996) holocene evolution of the carole barrier-lagoon (northern adriatic sea, i t a l y ). rivista ital. paleont. e strat., 1 0 2, 3, 385-396. marocco r., maselli scotti f., melis r. & vio e. (2005) il sottosuolo del castrum di grado (adriatico settentrionale): studi preliminari per una ricostruzione paleogeografia. il quaternario, 18 (2), 135-146. munsell soil color charts (1975) macbeth division of kollmorgen corporation, baltimore, maryland. mu r r a y j.w. (1991) ecology and palaeoecology of benthic foraminifera. longman, harlow, 397 pp. mu r r a y j.w. & al v e. e. (1999) taphonomic experiments on marginal marine foraminiferal assemblages: how much ecological information is preserved? palaeogeogr., palaeoclimat., palaeoecol., 149, 183-197. nota d.j.g., (1958) sediments of the western guiana s h e l f. reports of the orinoco shelf expedition, meded vol. 50, landbouwhogeschool, wageningen, 1-98. passega r. (1957) texture as characteristics of clastic deposition. bulletin american ass. of petr. geol., 41 (9), 1952-1964. pa s s e g a r. (1964) grain size representation by cm patterns as a geological tool. jour. sed. petrol., 34, 830-847. reimer p.j., baillie m.g.l., bard e., bayliss a., beck j.w., be r t r a n d c.j.h., bl a c k w e l l p.g., bu c k c.e., bu r r g.s., cu t l e r k.b., da m o n p . e . , ed w a r d s r.l., fa i r b a n k s r.g., fr i e d r i c h m . , guilderson t.p., hogg a.g., hughen k.a., kromer b., mcco r m a c g., ma n n i n g s., ra m s e y c . b . , re i m e r r.w., re m m e l e s., so u t h o n j.r., st u i v e r m., ta l a m o s., ta y l o r f.w., va n d e r pl i c h t j . , we y h e n m e y e r c . e . (2004) intcal04 terrestrial radiocarbon age calibration, 0–26 cal kyr bp. radiocarbon, 46 (3), 1029-1059. se i d e n k r a n t z m.-s. & kn u d s e n k.l. (1993) m i d d l e weichselian to holocene palaeoecology in the eastern kattegat, scandinavia: foraminifera, ostracods and 14c measurements. boreas, 22 (4), 299310. sg a r e l l a f. & mo n c h a r m o n t ze i m . (1993) b e n t h i c foraminifera of the gulf of naples (italy): systematics and autoecology. boll. soc. paleont. it.,3 2, 145264. st a c u l a . (1995 -1996) la geologia della piana del lisert. geomorfologia del substrato e litostratigrafia della copertura . tesi di laurea inedita. università di trieste. 67 pp. te n t o r m., tu n i s g . , & ve n t u r i n i s., (1994) s c h e m a stratigrafico e tettonico del carso isontino. natura nascosta, 9, 1-32. zanier k., (2009) tra aquileia e lacus timavi. il conte sto del »ponte« romano di ronchi dei legionari, studi e ricerche sulla gallia cisalpina 22, edizioni quasar, roma, zaninetti l. (1992) les foraminifères des marais salant de salin-de-giraud (sud de la france): milieu de vie et transport dans les salin, comparaison avec les microfaunes marines. géol. méditer., i x, 4, 447-470. 170 ms. ricevuto il 3 aprile 2009 testo definitivo ricevuto il 30 luglio 2009 ms. received: april 3, 2009 final text received: july 30, 2009 r. marocco & r. melis 10vitietal strain rate field from geodetic velocity measurements: an approach based on numerical modelling viti m.1, mantovani e.1, cenni n.2, babbucci d.1 1dip. di scienze della terra, univ. di siena, e-mail: vitimar@unisi.it 2dip. di fisica, univ. di bologna abstract: m. viti et al., strain rate field from geodetic velocity measurements: an approach based on numerical modelling. (issn it 0394-3356, 2009). the reconstruction of the strain rate field from geodetic velocity data is often carried out by geometrical procedures, such as subdivision in polygons of the geodetic network or interpolation of the velocity vectors. however, as discussed in this work, this kind of approach presents several shortcomings, which may affect the reliability of the computed strain rate field. in particular, the results of such approaches may be strongly biased by the fact that the mechanical properties of the crust in the zone considered are neglected. this problem may be overcome by the use of numerical modelling imposing the geodetic velocity vectors as kinematic constraints. as an example, the proposed procedure is applied to the central mediterranean region to determine the strain rate field associated with a recent geodetic (gps) velocity data set available in literature. the comparison of the result so obtained with the one derived by polygon subdivision shows that numerical modelling allows a more detailed and reliable recognition of the strain-rate field in the zones involved. riassunto: m. viti et al., calcolo del campo di deformazione da velocità geodetiche: metodologia basata sulla modellazione numerica. (issn it 0394-3356, 2009). il calcolo del campo di deformazione associato ad una rete di velocità geodetiche è spesso effettuato mediante procedure di tipo geometrico, come la suddivisione in poligoni della rete geodetica o l’interpolazione di velocità. in questo lavoro viene messo in evidenza che tali procedure presentano importanti limitazioni che potrebbero inficiare l’attendibilità dei risultati ottenuti. il problema principale è che gli approcci di tipo geometrico non impongono che la deformazione calcolata sia compatibile con le proprietà meccaniche della crosta. questo problema può essere superato adottando una procedura alternativa, basata sulla modellazione numerica della zona considerata. il modello è costituito da una piastra elastica sottile, la cui deformazione è vincolata dalle velocità geodetiche. come esempio, l’approccio proposto è applicato alla zona mediterranea centrale per calcolare il campo di deformazione associato ad una recente soluzione gps disponibile in letteratura. il confronto tra i risultati ottenuti ed il campo di deformazione calcolato mediante suddivisione in poligoni mostra che la modellazione numerica permette una più dettagliata e realistica definizione della distribuzione spaziale del tasso di deformazione nella regione considerata. key words: crustal strain rate, gps, numerical modelling, central mediterranean. parole chiave: campo della deformazione crostale, gps, modellazione numerica, mediterraneo centrale. il quaternario italian journal of quaternary sciences 22(1), 2009 109-116 introduction it is largely recognized that the reconstruction of the present strain field in a tectonic zone may provide major constraints for the elaboration of geodynamic and seismotectonic models (e.g., mantovani et al., 2001; viti et al., 2004) and for seismic hazard assessment (e.g., bird & liu, 2007). until recent years, such information was derived from the analysis of neotectonic and seismological data. however, difficulties in fault sampling and dating may severely limit the use of field kinematic indicators (e.g., marrett & allmendinger, 1990) and incompleteness and shortness of seismicity catalogues, along with uncertainties in source mechanism of historical earthquakes, may considerably bias the strain regimes obtained from moment tensor summation (e.g., viti et al., 2001). due to the rapid development of reliable and relatively inexpensive space geodetic techniques, in particular the global positioning system (gps), a new important approach for crustal deformation studies is now available (e.g. altamimi et al., 2007). so far, the computation of the strain rate field associated with velocity data is often carried out by geometrical approaches. the two most popular procedures are synthetized in the following: 1) polygonal subdivision: the study area is subdivided in a complex of polygons with vertexes in the gps stations and the average strain rate tensor is computed in each polygon (e.g. feigl et al., 1990; lamb, 2000; serpelloni et al, 2005); 2) interpolation: a continuous velocity field is determined by interpolating geodetic velocities, after which then the related strain rate field is derived (e.g. wessel & bercovici, 1998; beavan & haines, 2001; caporali et al., 2003). however, both these approaches present major limitations which may lead to unreliable strain rate fields. the main shortcoming is that they do not take into account the fact that the deformation of a real medium is not free, being controlled by continuum mechanics and rock properties. other problems are related to the fact that in each polygon, considered in the first technique, the strain rate tensor computed for the barycenter is assumed to be homogeneous throughout the polygonal area, despite the fact that this con110 m. viti et al. dition is rather unlikely in real contexts. on the other hand, when interpolation is considered, the computed strain rate field may be significantly influenced by the technique adopted. the above problems may be overcome by computing the strain rate field by numerical modelling of real crustal structures under the constraints imposed by geodetic velocities (e.g., lundgren et al., 1998). in this work, we apply the above approach to the central mediterranean region and compare the results obtained with the ones provided by a polygonal procedure. strain rate field reconstruction in the central mediterranean to show an example of the differences that may derive from computing the strain field by numerical modeling or by a polygonal procedure, we have considered the gps velocity solution obtained for the central mediterranean by serpelloni et al. (2005), using measurements carried out in the period 19912002 in a rather uniform density of permanent station (fig.1). numerical modelling the region covered by the geodetic network is simulated by a thin elastic sheet, using a finite element procedure implemented in the comsol multiphysics software package (comsol™, 2005). the sheet (about 1.500 x 1500 km2) has been discretized by a finite element grid including 4612 triangular quadratic lagrange elements. uniform elastic properties have been assigned to the whole sheet (young modulus e = 7.1010 pa and poisson ratio ν = 0.25 after lundgren et al., 1998). velocity vectors have been imposed to the nodes of the grid, corresponding to station sites. in the model, velocities are applied as instantaneous displacements. plane stress conditions have been adopted, as usually done in thin sheet approximation involving horizontal loading (e.g., segel, 1987). a series of numerical experiments, aimed at exploring the role of the internal and boundary conditions imposed on the elastic sheet, suggests that the solution of the elastic problem (i.e. the velocity and strain rate fields) is mostly controlled by the internal kinematic constraints (velocities imposed to the station sites). since a change of boundary conditions only (moderately) affects the peripheral zones of the model we show the solution obtained by imposing the most simple boundary condition, that is null stress on the four sides of the sheet (fig.2). the principal axes of the computed horizontal strain rate tensor show large lateral variations in both orientation and magnitude, ranging from negligible values to tens of nanostrain yr-1 (1 nanostrain yr-1 = 3.17 10-17 s-1). the largest strain rates occur in the eastern part of the model (western greece, among the orid, igou and kari stations. high strain rate values, associated to ne-sw lengthening, also occur at the boundary between central and southern apennines, near fig. 1 gps velocity solution for the central mediterranean proposed by serpelloni et al. (2005). arrows indicate the residual horizontal velocities with respect to an european reference frame (absolute euler pole located at latitude ϕ = 53.8 ± 1.9 °n, longitude λ = -105.5 ± 0.9 °e with angular velocity ω = 0.249 ± 0.003 ° myr-1). abbreviations of permanent gps stations as in serpelloni et al. (2005). velocità gps per il mediterraneo centrale proposte da serpelloni et al. (2005). le frecce rappresentano le velocità orizzontali residue calcolate rispetto ad un sistema di riferimento europeo, con polo euleriano assoluto: lat ϕ = 53.8 ± 1.9 °n , long λ = -105.5 ± 0.9 °e, velocità angolare ω = 0.249 ± 0.003 ° myr-1. sigle delle stazioni gps permanenti come in serpelloni et al. (2005). the cass and mira stations. significant transtensional strain rates occur in the tuscany-umbria zone, among the elba, prat, unpg and cast stations. compressional to transpressional strain characterizes the northern and northeastern sectors of the model (southern alps and dinarides). 111strain rate field from ... comparison with the strain rate field derived by a polygonal procedure the strain rate field given by serpelloni et al. (2005) is shown in figure 3. the region covered by the geodetic network has been subdivided in 37 polygons, with vertexes in the station sites. the horizontal strain fig. 2 strain rate field (red bars and arrows) obtained by the finite element modelling described in the text. computed velocity vectors (gray arrows) are reported on a 15 x 15 point grid (100 km spacing). principal axes of the strain rate tensor are reported on a 30 x 30 point grid (50 km spacing). the velocity vectors (fig. 1) have been imposed in station sites. the null stress condition has been imposed to the boundaries of the model. a young modulus (e) of 7 1010 pa and a poisson ratio (ν) of 0.25 have been adopted. campi della velocità e del campo di deformazione ottenuti dalla modellazione agli elementi finiti descritta nel testo. i vettori di velocità (frecce grigie) sono riportati su una griglia con spaziatura di 100 km tra punti adiacenti. gli assi principali del tensore del tasso di deformazione sono riportati (in rosso) su una griglia con spaziatura di 50 km. i vettori velocità mostrati in figura 1 sono stati applicati nei punti del modello corrispondenti alle stazioni gps. la condizione di sforzo nullo è stata imposta ai bordi del modello. i parametri elastici adottati per la piastra sono e = 7 1010 pa e ν = 0.25. 112 rate tensor is computed in the barycenter of each polygon by using the vectors in the respective vertexes (feigl et al ., 1990). a comparison of figure 3 with the strain rate field shown in figure 2 clearly shows that the procedure here proposed allows us to recognize the lateral heterogeneities of the strain rate pattern inside the geodetic network. this would also be allowed by interpolation of geodetic vectors, but such procedure does not guarantee that the results obtained are compatible with rock mechanics. one must be aware that the reliability of the results provided by numerical modelling depends on how the adopted rheological properties are representative of the real context. on the other hand, the results of this last approach are certainly more realistic than the average strain rate provided by geometrical procedures or than the strain pattern obtained by allowing a free deformation of the crust in the zone involved. to better focus on this crucial aspect, details on the numerical and geometrical strain rate tensors are provided (figs 4, 5 and 6) for three polygons (33, 14 and 4 in figure 3). in polygon 33, covering the centralnorthern adriatic region (fig. 4), the geometrical approach provides a roughly ne-sw uniform shortening, which is not compatible with the results of neotectonic and seismological data that indicate a roughly sw-ne compression at the eastern adriatic border and a rather heterogeneous strain field in the apennine belt, involving shortening at the outer fronts of the chain and extensional to transtensional strain regime in the axial part (e.g., cello et al., 2003; piccardi et al., 2006; ferranti et al., 2008, 2009). this last evidence is more compatible with the results of numerical modelling for the above polygon, which shows that the direction of maximum shortening considerably changes from the western sector (where it is about e-w near the stations of msic and baso) to the eastern part (roughly n-s near station trem and nne-ssw to ne-sw between stations baso and dubr). in polygon 14, covering the axial part of the central apennines (fig. 5), the polygonal solution provides a roughly e-w uniform extensional style, that does not report any evidence of the sinistral transtensional regime recognized in that zone by the analysis of neotectonic and seismicity data (e.g., amoruso et al., 1998; galadini, 1999; piccardi et al., 2006). in the same polygon, the numerical solution shows a dominant strikeslip strain rate field with significant lateral variations of the amplitude and ratio of principal axes, which is more consistent with the observed strain pattern. in polygon 4, located in the northern part of southern calabria (fig. 6), the polygonal solution shows a uniform nw-se extension, that does not inform us about the considerably heterogeneous strain pattern fig. 3 strain rate field obtained by subdiving the region considered in 37 polygons (after serpelloni et al., 2005). for each polygon, the principal axes of the horizontal strain rate tensor, computed in the polygon barycentre, are shown. campo del tasso di deformazione ottenuto mediante suddivisione della rete geodetica in 37 poligoni (da serpelloni et al., 2005). gli assi principali del tensore del tasso della deformazione orizzontale sono calcolati nel baricentro di ogni poligono. m. viti et al. 113 fig. 4 strain rate field for the polygon 33 of figure 3 (central adriatic). station abbreviations as in figure 1. a) strain rate field provided by the numerical solution shown in figure 2. grid spacing is 50 km. b) strain rate computed in the barycenter (after serpelloni et al., 2005). campo del tasso di deformazione per il poligono 33 di figura 3 (adriatico centrale). le sigle delle stazioni gps sono quelle indicate in figura 1. a) campo del tasso di deformazione relativo alla soluzione numerica di figura 2. la spaziatura dei punti della griglia è 50 km. b) campo del tasso di deformazione calcolato nel baricentro (da serpelloni et al., 2005). fig. 5 strain rate field for the polygon 14 of figure 3 (central-northern apennines). station abbreviations as in figure 3. a) strain rate field provided by the numerical solution shown in figure 2. grid spacing is 50 km. b) strain rate computed in the barycenter (after serpelloni et al., 2005). campo del tasso di deformazione per il poligono 14 di figura 3 (appennino centro-settentrionale). le sigle delle stazioni gps sono quelle indicate in figura 1. a) campo del tasso di deformazione relativo alla soluzione numerica di figura 2. la spaziatura dei punti della griglia è 50 km. b) campo del tasso di deformazione calcolato nel baricentro (da serpelloni et al., 2005). strain rate field from ... 114 indicated by neotectonic and seismological data (neri et al., 2005, tansi et al., 2007) the analysis of other geodetic information (ferranti et al., 2008) and the results of seismic surveys (finetti, 2005). in the same polygon, the numerical solution indicates a gradual transition from transpression in the southern part to extension in the northern part, which agrees with the results recently obtained by the analysis of geodetic campaignes in that zone (ferranti et al., 2008). conclusions geodetic observations give a precious opportunity to know the present velocity and strain rate field in a region covered by a relatively dense network of stations. however, the computation of the strain rate field associated to the observed velocity vectors must be carried out by a procedure compatible with rock mechanics, which can be achieved, for instance, by numerical simulation with realistic models. in order to provide an example of the differences that can derive from the adoption of the above alternative procedures, we compare the results obtained by their application to a velocity data set in the central mediterranean region. such analysis suggests that numerical modelling allows a more detailed and reliable recognition of the strainrate field in the zones involved. references altamimi z., collilieux x., legrand j., garayt b. & c. boucher (2007) itrf2005: a new release of the international terrestrial reference frame based on time series of station positions and earth orientation parameters. j. geophys. res., 112, b09401. amoruso a, crescentini l & scarpa r. (1998) inversion of source parameters from nearand far field observations: an application to the 1915 fucino earthquake, central apennines, italy. j. geophys. res, 103, 29989-29999. beavan j. & haines j. (2001) contemporary horizontal velocity and strain rate fields of the pacificaustralian plate boundary zone through new zealand. j. geophys. res., 106, 741-770. bird p. & liu z. (2007) seismic hazard inferred from tectonics: california. seismological research letters, 78, 37-48. caporali a., martin s. & massironi m. (2003) average strain rate in the italian crust inferred from a permanent gps network-ii. strain rate versus seismic and structural geology. geophys. j. int., 155, 254268. cello g., tondi e., micarelli l. & mattioni l. (2003) active tectonics and earthquake sources in the epicentral area of the 1857 basilicata earthquake (southern italy). j. geodynamics, 36, 37-50. comsol™ (2005) comsol multiphysics user’s guide, version 3.2. comsol ab, stockholm, 622 pp (www.comsol.com). feigl k.l., king r.w. & jordan t.h. (1990) geodetic measurement of tectonic deformation in the santa maria fold and thrust belt, california. j. geophys. res., 90, 2679-2699. ferranti l., oldow j. s., d’argenio b., catalano r., lewis d., marsella e., avellone g., maschio l., pappone g., pepe f.& sulli a. (2008) active deformation in southern italy, sicily and southern fig. 6 strain rate field for the polygon 4 of figure 3 (southern calabria). gps station abbreviations as in figure 1a. a) strain rate field provided by the numerical solution shown in figure 2. grid spacing is 50 km. b) strain rate computed in the barycenter (after serpelloni et al., 2005). campo del tasso di deformazione per il poligono 4 di figura 3 (calabria meridionale). le sigle delle stazioni gps sono quelle indicate in figura 1. a) campo del tasso di deformazione relativo alla soluzione numerica di figura 2. la spaziatura dei punti della griglia è 50 km. b) campo del tasso di deformazione calcolato nel baricentro (da serpelloni et al., 2005). m. viti et al. sardinia from gps velocities of the perityrrhenian geodetic array (ptga). boll. soc. geol.it. (ital.j.geosci.), 127, 299-316. ferranti l., santoro e., mazzella m.e., monaco c. & morelli d. (2009) active transpression in the northern calabria apennines, southern italy. tectonophysics, in press, doi:10.106/ j.tecto.2008.11.010. finetti i.r. (2005) the calabrian arc and subducting ionian slab from new crop seismic data. in: finetti, i.r. (ed.), deep seismic exploration of the central mediterranean and italy, crop project, elsevier, 17, 393-412. galadini f. (1999) pleistocene change in the central apennine fault kinematics, a key to decipher active tectonics in central italy. tectonics, 18, 877894. lamb s. (2000) active deformation in the bolivian andes, south america. j. geophys. res., 105, 25627-25653. lundgren p., giardini d. & russo r.m. (1998) a geodynamic framework for eastern mediterranean kinematics. geophys. res. lett., 25, 4007-4010. marrett r. & allmendinger r.w. (1990) kinematic analysis of fault slip data. j. struct. geol., 12, 973986. mantovani e., cenni n., albarello d., viti m., babbucci d., tamburelli c. & d’onza f. (2001) numerical simulation of the observed strain field in the central-eastern mediterranean region. j. geodynamics, 31, 519-556. neri g., barberi g., oliva g. & orecchio b. (2005) spatial variations of seismogenic stress orientations in sicily, south italy. phys. earth planet. int., 148, 175-191. piccardi l., tondi g. & cello g. (2006) geo-structural evidence for active oblique extension in southcentral italy. in: pinter, n. et al. (eds.), the adria microplate: gps geodesy, tectonics and hazard, springer, 95-108. segel l.a. (1987) mathematics applied to continuum mechanics. dover publications, new york, 590 pp. serpelloni e., anzidei m., baldi p., casula g. & galvani a. (2005) crustal velocity and strain-rate fields in italy and surrounding regions: new results from the analysis of permanent and non-permanent gps networks. geophys. j. int., 161, 861-880, doi:10.1111/j.1365246x.2005.02618.x. tansi c., muto f., critelli s. & iovine g. (2007) neogene-quaternary strike-slip tectonics in the central calabrian arc (southern italy) . j. geodynamics, 43, 393-414. viti m., albarello d. & mantovani e. (2001) classification of seismic strain estimates in the mediterranean region from a ‘bootstrap’ approach. geophys. j. int., 146, 399-415. viti m., de luca j., babbucci d., mantovani e., albarello d. & d’onza f. (2004) driving mechanism of tectonic activity in the northern apennines: quantitative insights from numerical modell ing. tectonics, 23, tc4003. wessel p. & bercovici d. (1998) interpolation with splines in tension: a green’s function approach. math. geol., 30, 77-93. 115 ms. ricevuto il 14 ottobre 2008 testo definitivo ricevuto il 6 aprile 2009 ms. received: october 14, 2008 final text received: april 6, 2009 strain rate field from ... << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /none /binding /left /calgrayprofile (dot gain 20%) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /error /compatibilitylevel 1.4 /compressobjects /tags /compresspages true /convertimagestoindexed true /passthroughjpegimages true /createjdffile false /createjobticket false /defaultrenderingintent /default /detectblends true /colorconversionstrategy /leavecolorunchanged /dothumbnails false /embedallfonts true /embedjoboptions true /dscreportinglevel 0 /emitdscwarnings false /endpage -1 /imagememory 1048576 /lockdistillerparams false 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quaternary, 33 (2), 2020, i-ii introduction to the special issue “historic and prehistoric landslides in the northern italian alps: implications for new hazard maps in mountainous areas”. sandro rossato 1, silvana martin 2, susan ivy-ochs 3, fabio gabrieli 4 � 1 institute of geosciences and earth resources, national research council of italy, padova, italy. 2 department of geosciences, university of padova, padova, italy. 3 department of earth sciences, eth zürich, zürich, and laboratory of ion beam physics, eth hönggerberg, zürich, schwitzerland. 4 department of civil, environmental and architectural engineering, university of padova, padova, italy people living and working in mountainous areas are familiar with landslides. these events are sadly known to pose a serious threat to people and infrastructures, being also a relevant process in landscape evolution. in the alps, where narrow valleys are increasingly inhabited, landslides occur every year, and some of them are responsible for a tragic number of casualties, and huge economic losses. in the last decades, a growing interest in such phenomena has developed, these phenomena being increasingly studied in all of their aspects. notwithstanding the uniformity of a goal to understand past failures as keys for assessing future events, the study of landslides has been dominated by an engineering geology approach, aimed at immediate risk reduction. in many cases, less attention has been paid to geomorphology, sedimentology, and dating. the landforms, sedimentology and internal structures of a landslide deposit provide direct information on the processes occurring during emplacement. back calculations and modelling of former rock-slope failures, when combined with the above, allow insight into movement processes photo of the participants to the summer school taken in the vajont valley, during fieldwork (photo: silvana martin, 4th july 2019). ii rossato s. et al. and emplacement sequences. reconstructing release and emplacement of mass movements provide fundamental data on the reasons for past and consequently possible future failure and extent of impacted areas. to evaluate which type of trigger (seismic, climatological, combined, man-made, ...) or driving factor played a role in slope failure is a major challenge, but there is a growing amount of data on this topic. landslides have been studied also as phenomena occurring on a certain area or time frame, moving the focus from the single event to a wider approach. clustering of some major rock slope failures in space and time have been recognized, pointing to triggers acting on vast areas. this volume collects contributions inspired by the summer school on “historic and prehistoric landslides in the ne italian alps implications for new hazard maps in mountainous areas”. this advanced course was organized by the university of padova (department of geosciences: prof. silvana martin and dr. sandro rossato; department of civil, architectural and environmental engineering: prof. fabio gabrieli) and eth zürich (prof. susan ivy-ochs). it was devoted to both early-career and experienced researchers dealing with landslide studies in the view of land management, risk reduction, and mapping. the summer school was held in 2019 at the university of padova, with teaching experts coming from many different countries. during the course, students and researchers, mainly, but not exclusively, european, had the opportunity to present and discuss their own work. more than half of the course consisted of fieldwork in the veneto and trentino/south tyrol regions. the course dealt with every aspect of landslide study: deposit investigation, failure and emplacement reconstruction, risk evaluation and monitoring in presently active sites. this volume reflects the multidisciplinary nature of the summer school that inspired it. wolter (2020) and viganò and scafidi (2020) focused respectively on predisposing and triggering factors, highlighting the importance of accurate structural and geophysical data in the landslide and, more in general, geologic studies. the investigations of three different events are also included: the pragser wildsee rock avalanche (ostermann et al., 2020), the mount salta rock-block sliderock fall (ghirotti et al., 2020), and the buchwiese rock avalanche (reitner et al., 2020). in the end, two review papers are presented, inspired by the summer school fieldwork in the veneto region (rossato et al., 2020) and the trentino/south tyrol area (martin et al., 2020). the special issue associate editors would like to take the opportunity to thank all the authors, the reviewers, and the editorial board of amq, whose individual contributions were fundamental. a special thank you is devoted also to the institutions that made the summer school possible thanks to their expertise and/or funding: the university of padova (departments of geosciences and civil, architectural and environmental engineering), the university of trento, the professional orders of the geologists of the trentino-alto adige region, the professional orders of the engineer of the veneto region, the geological survey of the autonomous provinces of trento and bolzano (italy), the eth zürich (switzerland), the geological survey of austria, the swiss society for quaternary research (ch-quat), the italian association for quaternary research (aiqua), the unesco dolomites foundation, and the sirive, incofil tech and unirock companies. � summer school historic and prehistoric landslides in the northern italian alps: implications for new hazard maps in mountainous areas list of the participants � � dr. jordan aaron eth zürich (ch); dr. raniero beber strathclyde university (uk); msc francesco bovo padova university (it); dr. paolo campedel geological survey, province of trento (it); prof. luca carniello padova university (it); msc ryan dick newcastle university (uk); msc davide festa bologna university (it); prof. fabio gabrieli padova university (it); dr. xavi gallach université savoie mont blanc (fr); prof. monica ghirotti ferrara university (it); msc gerit e.u. griesmeier geological survey of austria (at); dr. vladislav ivanov politecnico milano (it); prof. susan ivy-ochs eth zürich (ch); msc kacper jancewicz wroc�aw university (pl); msc sibylle knapp munich technical university (de); msc wioleta kotwicka wroc�aw university (pl); prof. franz livio insubria university (it); dr. volkmar mair geological survey, bolzano province (it); prof. silvana martin padova university (it); dr. costanza morino cnrs, université savoie montblanc (fr); prof. paolo mozzi padova university (it); prof. ryoko nishii niigata university (jp); dr. marc ostermann geological survey of austria (at); dr. alessandro pasuto irpi cnr, padova (it); dr. jürgen reitner geological survey of austria (at); prof. riccardo rigon trento university (it); prof. giorgio rosatti trento university (it); dr. sandro rossato padova university (it); prof. lorenzo sanavia university padova (it); msc carolina seguí duke university (usa); prof. nicola surian padova university (it); dr. hui tang german research centre for geosciences (de); dr. alfio viganò geological survey, province of trento (it); dr. andrea wolter gns science (nz); dr. jo wood exeter university (uk); prof. dario zampieri padova university (it); msc francesco zarattini padova university (it). available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 59 62 quaternary urban geology and foundations of heritage buildings: a few outstanding case histories from italy massimo coli, niccolò iandelli dst dipartimento di scienze della terra, università degli studi di firenze, firenze, italy corresponding author m. coli <massimo.coli@unifi.it> abstract: in this paper we analyse the urban geological setting of three outstanding italian cities, under the unesco patronage, in order to define the relationships between subsoil setting and historical building foundations. geological features play a key role on this topic and their knowledge is fundamental for any conservation project. keywords: urban geology, holocene, cultural heritage, building, foundations 1. introduction most of the main historical cities has been settled in plain areas, close to a river or to the sea, on quaternary deposits. in these areas, the ground is often constituted by recent unconsolidated, cohesive and granular, alluvial or paralic deposits, more or less thick and with complex sedimentary and lithological assemblages and with hiatus and heteropies. during time geological hazards like floods, subsidence and earthquakes, can severely damage or even destroy heritage buildings. in this context, urban geology, devoted to the study of the recent geological aspects, underground geological setting and geotechnical properties, plays the main role due to its great influence on the foundation, ensuring stability and durability of the heritage buildings. in this paper, we outline the role played by the urban geology for a few selected italian outstanding cities in the foundations behaviour of their main heritage buildings. namely we analyse the case histories of firenze city centre, venezia and pisa; they all are unesco human cultural heritage sites. 2. case histories 2.1. firenze firenze was settled by the romans in the ii century b.c. in a natural territory with swamps, marshlands and a river with a large bed within which it flew with braided channels. first the romans reclaimed the plain for agriculture through the centuriazione, whose imprinting is still deeply marking the territory as cadastral parcels and ditches and drains. during its history firenze has been expanding, reclaiming the flood territory all around. the firenze-pistoia basin has been developing since the piacenzian, dismantling the zanclean low energy surface; this recent geological evolution, according to the allostratigraphy criteria, resulted into continental clastic deposits grouping into three ubsu (briganti et al., 2003, coli & rubellini, 2013) including: synthem of the basin: lacustrine, alluvial and fan deposits; piacenzian-gelasian. ancient deposits: river-bed gravel of the paleo-arno; late pleistocene. recent deposits: river-bed and alluvial deposits of the arno river and tributaries, with swamps and marshlands in the plain; holocene. in the historical city centre area, the recent deposits of the alluvial bed of the arno river directly lie on the bedrock; here, below a few meters of archaeological layer, the recent deposits are constituted at top by around 2 m of over-bank sands and silty-sands and below by river-bed deposits mainly made of pebbles and gravels, from clean to silty, with layers and lenses of locally graded sands; they are referred to a fluvial subaerial environment where the arno river braided unconstrained in its alluvial bed, but periodically flooded large portions of the plain. in the city centre there are two sites of main interest: the religious complex of the cathedral with the brunelleschi’s dome, the baptistery and the giotto’s bell tower, and the civil complex of palazzo vecchio and uffizi gallery; here the subsoil sequence is (fig. 1): historical archaeological layer (v-xii century a.d.), about 3-4 m thick, corresponding to roman and early medieval buildings ruins and debris. about 2 m of silty-sand of banks and overs-banks. about 12 m of river bed gravel. bedrock, at around 17 m depth below the street datum in the cathedral area and around 10-12 depth below the street datum in the palazzo vecchio area. the recent deposits of the firenze area display good geotechnical properties, gravels fall into the gw/gp fields of the uscs (astm 1988) and sands into the sp/ sw fields. sands and gravel have vs = 120 m/s and vs = 400 m/s, respectively. gravels are most calcareous, dense and self-sustaining, with = 37°+/6°, as statistically deriving from 203 nspt data from the whole city centre area. the archaeological debris have nspt data ranging from 5 to 7. the water table is stable at about 7 m below the ground datum, with a seasonal excursion of about +/1.5 m and in equilibrium with the arno river, https://doi.org/10.26382/aiqua.2018.aiquaconference which in turn is kept on level by a barrage downstream the historical city. the foundation of the main historical buildings of firenze date back to the xiii century and is constituted by massive bodies of mortared stones, with a high quality mortar. they are 6 m depth and rooted into the gravels, right above the water table. 2.2 venezia venezia is located in a complex foreland setting near the pinch-out of both the south alpine and the apenninic wedges, which developed during serravallianmessinian ad early pliocene times, respectively. the present-day venezia area was reached by the northadriatic turbidite system during the early to middle pleistocene, due to the north-eastward shifting of the apenninic fore-deep (bassan and vitturi 2003). the holocene-pleistocene transition is marked by the caranto, which is an over-consolidated layer of sand and clay mixture considered to be the last continental unit before the holocene (flandrian) transgression, that progressively submerged the “würmian” palaeoplain and the caranto itself, here interpreted like a hardground (bonardi & tosi, 1994). the early holocene sediments are represented by a discontinuous level of silt and sand, often with chaotic structure mixed with shelly marine-lagoon sands due to the sediment redistribution operating by the sea currents on the clasts supplied by the rivers descending by the alps. venezia is placed on the recent lagoon deposits, the water table is at the sea level about 1÷1.5 m below the streets datum and therefore all the sediments are saturated. during the quaternary, the lagoon underwent some discontinuous phases of alternating marine transgressions and regressions, as a result of which both marine and continental sediments coexist (fig. 2) (zezza, 2008 cum bib). both recent lagoon and fluvial pleistocene soils display bad geotechnical features: for cohesive layers cu values range between 5°÷35°; vs values are around 265 m/s. cohesive layers display very high compressive and plasticity indexes, only the caranto layer, has a certain grade of stiffness. the lagoon deposits present a typical soil profile characterized by the presence of the following type of sediments, according to uscs (astm 1988): 35% sands (sp, sm), 35% silts (ml), 25% clays, (cl), 5% soils with relevant organic matter (mh, oh, pt). therefore, both cohesive and granular soils are subject to compaction due both to natural factors and to 60 coli m., iandelli n. fig. 1 schematic subsoil setting of the main historical buildings at firenze. fig. 2 subsoil geological setting of venezia along a cross-section (after zezza 2008). 61 the load of the city buildings. in the city area that resulted into a subsidence rate of around 0.6 mm/y, with subsidence differentiated through the city according to the local subsoils setting. in venezia buildings foundations consist of a complex system based on the interaction of wood, water and soil. because surficial soils have a low lift capacity, ancient builders used wooden poles in order to improve the geotechnical properties of the first layers and transfer the load to the below caranto layer where poles had been rooted. this type of foundation is called "indirect foundation" (biscontin et al., 2011). 2.3 pisa pisa was settled by the etruscans in the vii century b.c. on the coastal plain, at the confluence of auser (ancient serchio) and arno rivers, close to the coast as a harbour. later on, the sediments supplied by the arno and serchio rivers and beach sand cordons moved the coast west away from pisa. the pisa plain is the top of an inner inter-montane basin developed since late tortonian, which development had been controlled by normal faults on the eastern side. above messinian to pleistocene deposits, the recent holocene deposits consists of fluvial and paralic clastic sediments supplied by the incoming rivers, most the arno and the auser rivers. in particular, the city of pisa lies above a deep paleo-valley eroded by arno river during the last lowstanding of the “würm ice-age” into pleistocene and pliocene marine deposits. later on, the paleo-valley was infilled by down-lap arno river fluvial sediments from east and on-lap marine sediments from west, in a complex relationship of paralic environments: estuary, lagoon, coastal plain, bay-head delta, floodplain, fluvial channel; these recent infilling and the top sediments are mainly constituted by sands and clays (fig. 3) (aguzzi et al., 2005, 2007; amorosi et al., 2008; sarti et al., 2015). the soil of the pisa area presents a certain grade of over-consolidation that had been mainly attributed to the effects of ageing and, to a minor extent, to mechanical over-consolidation, due to erosion-re-deposition processes and water table fluctuation; all are soft soils with bad geotechnical properties. the leaning tower has ring-like shallow foundation, rooted up to 2 m below the ground datum, right above the water table (mlp 1971). walls and foundations were made in wall-bag mode, with mortar of no very good quality; in the year 1935 the foundations were reinforced by grouting and with a concrete outer ring. under the overburden of the tower, subsoil has been undergoing progressive viscousplastic deformation, which resulted into a vertical settlement of 2.5 m and symmetric rotation of the tower, the leaning rate before the recent conservation works was of around 1.5 mm/y. this natural process had been helped by the pumping out water, since the 1950’s, with subsidence of the whole pisa plane. in order to stop/ reduce the increasing leaning of the tower which was becoming critic, in the 1965 the ministry established a urban geology and historical buildings foundation fig. 3 subsoil setting of the pisa area evidencing arno paleo-valley during the last “ice-age” (after amorosi et al. 2008). national scientific committee (nsc) that proceed to soil sub-excavation below the upright side of the tower; the works were executed in the year 2000-2001 by means of 41 drill-holes. these works allowed to achieve a gain of 0.5° of back-rotation and to put on safety the tower for the close future. 3. remarks when we have to address a problem of conservation for ancient historical buildings first of all we must acquire a historical and technical full knowledge of the monument, and of its detailed geological and subsoil setting, foundations and materials and original building techniques. only after we have achieved these goals we can design conservation interventions in the full respect of the monument authenticity and integrity. the interventions must be carried out with the in-depth knowledge of the geological and depositional characteristics, and with knowledge of the stratigraphic sequences, the geological model and the type of depositional events in the period that goes from the last glaciation to now. references aguzzi m., amorosi a., sarti g. (2005) stratigraphic architecture of late quaternary deposits in the lower arno plain (tuscany, italy). geologica romana, 38, 1-10. aguzzi m., amorosi a., colalongo m.l., lucchi m.r., rossi v., sarti g., vaiani s.c. (2007) late quaternary climatic evolution of the arno coastal plain (western tuscany, italy) from subsurface data. sedimentary geology, 202(1), 211-229. amorosi a., sarti g., rossi v., fontana v. (2008) anatomy and sequence stratigraphy of the late quaternary arno valley fill (tuscany, italy). geoacta, special pubbl. 1, 55-66. astm (1988) d2487-11 standard practice for classification of soils for engineering purposes (unified soil classification system). american society for testing and materials, http://www.astm.org/. bassan v., vitturi a. (2003) studio geoambientale del territorio provinciale di venezia. parte centrale. provincia di venezia-sigea, serv. graf. ed., padova, pp. 112. briganti r., ciufegni s., coli m., polimeni s., pranzini g. (2003) underground firenze: plio-quaternary evolution of the firenze area. boll. soc. geol. it., 122, 435-445. bonardi m., tosi l. (1994) the holocene-pleistocene boundary zone in the lagoon of venice – in: marabini f. editor, italian contribution to the china-italy bilateral seminar on marine geology, (4-6 october 1994, qingdao, china). istituto di geologia marina, cnr, bologna, tech. rep. 40, 18-24. biscontin g., izzo f.c., bini c., rinaldi e., macchioni n., pizzo b., capretti c., molon g., regini m., lionello a., cavaggioni i., morabito z. (2011) wooden foundations in venice: a preliminary study. schipwrecks 2011 chemistry and preservation of waterlogged wooden shipwrecks, stockholm, royal institute of technology, convegno, 18-21 ottobre 2011. coli m., rubellini p. (2013) geological anamnesis of the firenze area, italy. z. dt. ges. geowiss. (german j. geosci.), schweizerbart’sche verlagsbuchhandlung, stuttgart, germany, 581-589. mlp (1971) ricerche e studi su la torre pendente di pisa e i fenomeni connessi alle condizioni d’ambiente. ministero lavori pubblici, commissione per il consolidamento della torre di pisa. igm, firenze, 3. sarti g., rossi v., giacomelli s. (2015) the upper pleistocene “isola di coltano sands” (arno coastal plain, tuscany italy): review of stratigraphic data and tectonic implications for the southern margin of the viareggio basin. atti soc. tosc. scie. nat. mem., serie a, 122, 75-84. zezza f. (2008) geologia: proprietà e deformazione dei terreni del centro storico di venezia. geologia dell’ambiente, sigea, 3/2008, 129-170. 62 coli m., iandelli n. ms. received: april 30, 2018 final text received: may 28, 2018 http://www.astm.org/ 05desimoneetal. episodi vulcanici e vulcanoclastici (v-xvii secolo) che hanno sepolto un edificio romano a pollena trocchia (italia) g.f. de simone1*, a. perrotta2 , c. scarpati2, a. de simone3, r.t. macfarlane4 1st. john’s college, university of oxford, uk, e-mail: desimone@archeolinks.com 2dipartimento di scienze della terra, università degli studi federico ii, napoli 3università degli studi suor orsola benincasa, napoli 4apolline project, department of classics, brigham young university, provo, utah usa riassunto: g.f. de simone et al., episodi vulcanici e vulcanoclastici (v-xvii secolo) che hanno sepolto un edificio romano a pollena trocchia (italia). (it issn 0394-3356, 2009). il territorio nord-vesuviano è ancora poco noto archeologicamente. l’attività di indagine archeologica e vulcanologica in un sito nel comune di pollena trocchia fornisce nuovi elementi per chiarire le dinamiche di seppellimento avvenute nell’area con l’eruzione del 472 d.c. e le successive. fino ad ora sono stati portati alla luce sette ambienti di un edificio romano verosimilmente costruito nel ii/iii secolo d.c. l’edificio si sviluppava su due piani, del superiore sono presenti solo i pavimenti ed i crolli dei muri, quello inferiore era già significativamente danneggiato e spoliato prima del seppellimento causato dall’eruzione vesuviana del 472 d.c. la sequenza stratigrafica affiorante consta di 7 unità stratigrafiche separate da paleosuoli. quattro unità sono costituite esclusivamente da depositi piroclastici messi in posto durante un evento eruttivo di natura esplosiva; tre unità sono costituite da materiale vulcanoclastico messo in posto durante le fasi finali di un’eruzione o periodi di quiescenza del vulcano. sulla base dei caratteri stratigrafici e litologici, nonché delle evidenze archeologiche (ritrovamento di elementi che permettono di datare degli specifici orizzonti) alcune unità stratigrafiche sono state associate a specifiche eruzioni vesuviane. in particolare, la spessa successione basale, che ha sepolto buona parte dell’edificio, è associata alle fasi finali di rimobilizzazione della coltre piroclastica dai versanti del somma alla fine dell’eruzione del 472 d.c. le strutture poste al di sopra del deposito eruttivo testimoniano di una successiva frequentazione bruscamente interrotta dal successivo evento vulcanico (probabilmente pertinente all’eruzione del 512 d.c.). l’area è definitivamente abbandonata e ricoperta, nei secoli successivi, da materiale vulcanoclastico e sottili depositi vulcanici. la sequenza stratigrafica studiata mostra come l’impatto di eventi secondari (lahar) sia la principale causa di distruzione e successivo seppellimento dell’edificio romano. abstract: g.f. de simone et al., burial of a roman building at pollena trocchia (italy) by volcanic and volcanoclastic episodes (vxvii century). (it issn 0394-3356, 2009). the north slope of the somma-vesuvius complex is archaeologically still little known. archaeological and volcanologic field research at a site in the town of pollena trocchia offers new data for understanding the burying process of the ad 472 eruption and following eruptive events. so far seven rooms of a roman building have been brought to light, which probably date to the 2nd/3rd century ad. the building consists of two storeys. the floors and the collapse of peripheral walls are the only remains of the upper floor. the lower storey was already severely damaged and spoliated before the ad 472 vesuvian eruption which buried it. the exposed burial sequence is constituted by 7 stratigraphic units interlayered with paleosoils. four units are exclusively composed of pyroclastic deposits deposited during an explosive eruption. three units are formed by volcanoclastic debris deposited during either the final phases of the eruption or sometime afterwards. the stratigraphic and lithological features, and the archaeological evidence correlate some of these stratigraphic units with known vesuvian eruptions. in particular, the thick basal sequence that buried most of the building is associated with the reworking of pyroclastic deposits on the north side of the volcano during the last phases of the ad 472 eruption. the structures placed on top of the volcanoclastic deposit testify to a later phase of life, which was quickly interrupted by a subsequent eruption (probably that of ad 512). the whole area was subsequently completely abandoned and covered by volcanoclastic and volcanic debris throughout the following centuries. the stratigraphic sequence attests the impact of secondary events (lahars) as the main cause of destruction and burial of the roman building. parole chiave: vesuvio, lahar, siti archeologici. keywords: vesuvius, lahar, archaeological sites. il quaternario italian journal of quaternary sciences 22(1), 2009 53-60 1. introduzione il territorio nord-vesuviano (fig. 1), per una complessa serie di fattori storici e culturali (de simone, 2007), non è stato mai oggetto di indagine archeologica sistematica. ciò ha comportato, in una prima fase, la lettura dei siti archeologici di volta in volta ritrovati secondo modelli interpretativi modellati sulle realtà archeologiche più note di pompei ed ercolano. in particolare, era comune la prassi di datare genericamente i siti archeologici ricadenti nell’ambito del vulcano al i secolo d.c., partendo dall’assunto che l’interro vulcanico rilevato fosse sempre relativo al 79 d.c. (della corte, 1932; de franciscis, 1976). in tempi più recenti, la ricerca sugli insediamenti protostorici in area nolana da un lato (albore livadie et al., 1998) e la necessità di definire in ambito pompeiano le vicende storiche ed insediative posteriori al 79 dall’altro (cerulli irelli, 1975; pisapia, 1981; pagano, 1995; de carolis, 1997; soricelli, 1997; id., 2001; de simone & nappo, 2000; de simone, 2002; pappalardo, 2001; ebanista, 2003), hanno portato al superamento dell’usuale quadro cronologico di riferimento, senza peraltro giungere alla formulazione di nuovi modelli interpretativi idonei a spiegare le complesse vicende insediative. il territorio nord-vesuviano mostra inoltre un grado di complessità maggiore rispetto al versante meridionale del vulcano. infatti, negli ultimi anni ricerche archeo54 g.f. de simone et al. logiche e vulcanologiche (colucci pescatori, 1986; albore livadie et al., 1998; mastrolorenzo et al., 2002; perrotta et al., 2006a; ead., 2006b) hanno evidenziato significative differenze nelle modalità di distruzione e seppellimento degli insediamenti di età romana ubicati sul versante settentrionale del vesuvio, rispetto a quanto accaduto alle più famose cittadine poste sul versante meridionale del vulcano (sigurdsson et al., 1985; cioni et al., 1990; luongo et al., 2003a; id., 2003b). è infatti ben noto che pompei, ercolano e stabia sono state rapidamente sepolte (in pochi giorni secondo la descrizione di plinio il giovane a tacito) sotto una spessa coltre di depositi piroclastici associati all’eruzione del 79 d.c. il ritrovamento di numerose ville rustiche ricoperte dai depositi del 79 d.c. (stefani, 2000; ead., 2002), variamente ubicate sulle pendici del vulcano, ha rafforzato l’idea di una distruzione complessiva di tutto il territorio perivulcanico a seguito dell’intensa eruzione pliniana. le avverse condizioni ambientali determinate dalla deposizione dei prodotti dell’eruzione, unitamente ad alcuni rilevanti fattori politici ed economici, hanno scoraggiato il ripristino dei centri urbani o la costituzione di nuovi, nonché la creazione di una rete di insediamenti extraurbani che fosse fitta come la precedente. il territorio nord-vesuviano offre un quadro, se non completamente diverso, quanto meno più complesso ed articolato. per quest’area, la prima ricerca accademica in siti di età storica è cominciata solo nel 2002, ed è ancora in corso, per opera della università di tokyo con collaborazioni internazionali (aoyagi, 2005; aoyagi et al., 2006; id., 2007; de simone & matsuyama, 2006). il progetto ha come obiettivo lo scavo sistematico di una villa romana di notevoli dimensioni sita in somma vesuviana in località starza della regina (fig. 1) e ritenuta ai tempi della scoperta (della corte, 1932) la residenza dove morì augusto. i depositi vulcanici, che arrivano a coprire per quasi 10 metri l’edificio, furono interpretati al momento della scoperta come pertinenti all’eruzione vesuviana del 79 d.c. (della corte, 1932), attestando quindi anche nel settore settentrionale del vulcano un interro analogo a quello costiero. le recenti indagini vulcanologiche (perrotta et al., 2006a; ead., 2006b) escludono la presenza dei depositi dell’eruzione del 79 d.c. nell’area di scavo e consentono invece una ricostruzione degli eventi notevolmente diversa da quella proposta per pompei ed ercolano. il monumentale edificio era in avanzata fase di spoliazione prima che i prodotti dell’eruzione del 472 d.c. ricoprissero i due terzi della struttura. i prodotti di numerose altre successive eruzioni (dal 512 al 1631) e di eventi di natura secondaria (lahar) completarono l’opera di seppellimento nel corso dei secoli successivi. con lo stimolo di tale ricerca e nella necessità di verificare i dati su di un secondo sito e di porre domande di respiro più ampio e di maggiore validità per l’intero territorio, nel 2004 si è avviato un progetto di ricerca multidisciplinare condotto dalla università degli studî di napoli suor orsola benincasa insieme con la brigham young university (usa) ed il comune di pollena trocchia, con la collaborazione di studiosi dell’università federico ii di napoli per gli aspetti vulcanologici e paleobotanici. il progetto ha come obiettivo quello di svolgere un’attività di ricerca completa nel comune di pollena trocchia, inteso come campione per l’intero territorio oggetto d’indagine. la ricerca si è concretizzata nella disamina di quanto finora pubblicato, nello studio dei documenti inediti d’archivio, nella ricognizione sul territorio ed infine nell’analisi puntuale di un sito archeologico. in questa sede riportiamo i risultati preliminari della prima campagna d’indagine del sito prescelto, in località masseria de carolis (ora parco europa), mentre rimandiamo a quanto attualmente in corso di stampa (de simone, 2008; de simone & macfarlane, 2009) per la descrizione delle altre attività menzionate. 2. descrizione del sito il sito in località masseria de carolis (fig. 1; lat. 40°52'0.20"n, long. 14°22'33.63"e) è stato scoperto accidentalmente nel 1988 (pagano, 1988; id., 1991), quando si stava cavando materiale vulcanico nel corso dei lavori per la costruzione di edilizia popolare nell’area (attuale parco europa). l’allora funzionario archeologo di zona, mario pagano, documentando quanto allora fig. 1 il golfo di napoli con indicazione dei centri cui si fa riferimento nel testo. the bay of naples and the sites mentioned in the text. visibile ed impossibilitato nel poter condurre una campagna di scavo che gli permettesse di arrivare al livello del calpestio antico o almeno di scendere al di sotto dell’interro vulcanico e recuperare materiale ceramico datante, propose una lettura del sito come “grandi magazzini di ammasso di prodotti agricoli” costruiti nel ii secolo d.c. pagano propose inoltre che lo stato di spoliazione documentato dagli edifici antichi fosse collegabile alla notizia, riportata nei documenti borbonici, del ritrovamento di un grande sito a pollena, dal quale furono cavati circa 12.000 mattoni per la costruzione del teatro san carlo a napoli. gli elementi per ora in nostro possesso non consentono ancora una lettura chiara e definitiva, ma consentono di smentire almeno l’ultimo punto. l’area si mostrava, a circa 20 anni dalla scoperta, ampiamente sconvolta: la cava per il materiale vulcanico era stata utilizzata come discarica abusiva di materiale edilizio, che in parte copre ancora le strutture allora in luce. inoltre, la recinzione posta a protezione del sito era in gran parte divelta e l’area risultava invasa da rifiuti di varia natura. tale contesto complica la lettura delle strutture, nonché dell’interro vulcanico che le copriva e che ora è visibile solo in alcuni punti. i risultati preliminari della prima campagna d’indagine nel sito rivelano almeno 7 ambienti, molti dei quali mostrano tracce della originaria copertura a volta (fig. 2: a, b, c, d). vi sono ancora tracce in alcuni punti (c, e, f) dell’originario pavimento in cocciopesto. tale dato, insieme con i resti di crolli di alcuni muri (g, h), portano a supporre l’esistenza di un secondo piano del55episodi vulcanici e vulcanoclastici ... l’edificio. non è possibile per ora datare con precisione le strutture, ma la presenza al di sotto delle fondazioni di alcuni frammenti di affreschi databili allo stile transizionale tra iii e iv stile pompeiano lascia supporre che l’edificio ora messo in luce sia stato costruito al di sopra di uno precedente. non è possibile per ora essere certi su quando sia avvenuta la costruzione del nuovo complesso, verosimilmente nel ii o iii secolo d.c., ma esso mostra tracce di frequentazione fino alla tarda antichità, risultando sepolto, come si dirà in dettaglio di seguito, dai prodotti della eruzione del 472 d.c. la datazione del deposito è confermata dal rinvenimento di una piccola moneta in bronzo datata al regno di marciano (imperatore dell’impero romano d’oriente dal 450 al 457 d.c.), rinvenuta come unico elemento di corredo all’interno di una sepoltura infantile (maschio intorno ai 6 anni), posta all’interno dell’unico ambiente indagato in profondità (a) nell’ultimo strato di frequentazione prima dell’eruzione. la parte sommitale delle strutture fuoriesce dall’interro vulcanico del 472, a sua volta coperto da un sottile strato umificato, in cui sono presenti gasteropodi polmonati, similarmente a quanto accade nel citato sito di somma vesuviana; a pollena sono anche evidenti tracce di una successiva frequentazione. le strutture ancora emergenti sono infatti in gran parte spoliate; il materiale edilizio viene ammassato per elevare il livello di calpestio su cui è una struttura di incerta interpretazione (forno?; i), di modesta fattura, sigillata da materiale vulcanico probabilmente pertinente all’eruzione del 512 d.c. il sito mostra elementi di un certo interesse sia da fig. 2 pianta del sito archeologico nel comune di pollena trocchia, località masseria de carolis. map of the archaeological site in the town of pollena trocchia, location masseria de carolis. 56 un punto di vista strettamente storico ed archeologico per gli elementi finora illustrati, sia dal punto di vista vulcanologico e specificamente per quanto riguarda l’interazione del riempimento vulcanico con le strutture costruite, come si mostra di seguito. 3. stratigrafia la sequenza esposta nel sito è costituita da sette unità stratigrafiche, cioè depositi o successioni di depositi, di differente origine, separati da paleosuoli (fig. 3). le singole unità sono denominate con una lettera progressiva (da a a g) a partire dal deposito più antico (al di sopra degli strati antropizzati tardoantichi) e spostandosi verso l’alto. cinque unità (fig. 3: b, d, e, f e g) sono costituite esclusivamente da depositi piroclastici messi in posto durante un evento esplosivo e rappresentano, di conseguenza, delle unità eruttive. due unità (fig. 3: a e c) sono costituite da materiale vulcanoclastico messo in posto durante le fasi finali di un’eruzione o periodi di quiescenza del vulcano. le unità eruttive sono, se possibile, associate con eruzioni vesuviane conosciute sulla base delle loro caratteristiche litologiche e stratigrafiche. la sequenza basale consta di cinque depositi massivi (a1, a3, a5, a7 e a9) spessi da pochi decimetri a circa due metri, interstratificati con sottili livelli cineritici (a2, a4, a6 e a8). i depositi massivi sono costituiti essenzialmente da clasti di natura vulcanica immersi un una matrice di cenere grossolana. la matrice ha un colore ocra. i clasti, fino a 12 centimetri in diametro, non mostrano alcuna gradazione. la composizione di questi clasti è data prevalentemente da lave rossastre alterate e lave grigie afiriche e più rari frammenti calcarei. la loro forma varia da subangolare ad arrotondata. i sottili livelli cineritici sono stratificati e mostrano una variazione laterale in spessore. rari clasti pomicei arrotondati, di dimensioni da millimetriche a centimetriche, sono dispersi in questi l ivell i . localmente, in alcuni ambienti strutturalmente meglio preservati dell’edificio romano, i livelli cineritici stratigraficamente più alti (a6 ed a8) presentano delle evidenti ondulazioni con cruda stratificazione interna mentre alla base del livello a2 compare una lente formata da lapil l i pomicei fortemente arrotondati privi di matrice cineritica. la parte alta della successione è alterata e pedogenizzata; localmente si osserva un più marcato paleosuolo rosato spesso circa 10 centimetri in cui sono stati ritrovati numerosi gusci di gasteropodi polmonati perfettamente preservati (fig. 4). la natura vulcanoclastica di tale sequenza è discussa nel paragrafo 5. fig. 3 sequenza stratigrafica ricostruita dei depositi che hanno sepolto l’edificio romano. le lettere sulla sinistra della colonna indicano le unità stratigrafiche (da a a g) intercalate dai paleosuoli (da p1 a p7). le attribuzioni delle unità stratigrafiche a specifiche unità eruttive sono riportate sulla destra della colonna. reconstructed stratigraphic sequence of the deposits burying the roman building. capital letters indicate stratigraphic units (from a to g), paleosols range from p1 to p7. eruptive units are reported on the right. fig. 4 gusci di gasteropodi polmonati perfettemente preservati si tovano nel paleosuolo che copre l’unità a (472 dc). some preserved snail shells occur scattered in the soil at the top of unit a (472 ad). g.f. de simone et al. 57 sulla successione a poggia il deposito b1 che è formato da sottili lamine cineritiche piano-parallele, alternate a livelli di cenere più grossolana. il deposito successivo, b2, è costituito da più spessi livelli di cenere stratificata. sparsi lapilli pomicei di colore grigio chiaro sono dispersi nel deposito. il contatto basale è erosivo. un sottile paleosuolo rossastro si osserva alla sommità di b2. segue un deposito stratificato (da c1 a c3) in cui il livello basale (c1) è formato da cenere grossolana di colore grigio in cui sono disperse scorie e piccoli frammenti litici. c2 è un deposito cineritico marroncino in cui sono disperse rare pomici sia biancastre che grigiastre. anche il livello cineritico grigio c3 presenta rare pomici sia biancastre che grigiastre. questa successione è coperta da uno spesso paleosuolo. la parte rimanente della sequenza è formata da quattro sottili livelli piroclastici (d, e, f e g) interstratificati con spessi paleosuoli. il livello d è una cinerite discontinua lateralmente. il livello e, massivo, ben sortito ed è formato da lapilli scoriacei grigi subangolari. il livello f è discontinuo lateralmente ed è formato da cenere grossolana con abbondanti frammenti litici. infine, il livello cineritico g mostra rare scorie disperse nella matrice. 4. distribuzione delle unità stratigrafiche e relazioni con le strutture murarie le attività di sterro durante la scoperta del sito e la successiva trasformazione dell’area in discarica abusiva hanno reso impossibile la conservazione di un’unica sezione che comprendesse l’intera sequenza stratigrafica. la lettura della successione dei depositi eruttivi e vulcanoclastici sopra riportata è il risultato della collazione dei dati provenienti dai diversi saggi (fig. 5) d’indagine i quali, posti a quote diverse, consentono attraverso la sovrapposizione di strati della stessa fase, la ricostruzione dell’intera sequenza. il saggio 05 offre il primo pezzo della sequenza. lo scavo si è infatti approfondito all’interno dell’ambiente originariamente voltato, fino ad arrivare al di sotto del piano di fondazione delle strutture murarie. in questo livello, misto in uno strato di cenere vulcanica sono stati trovati frammenti di stucco decorato dello stile transizionale tra iii e iv stile pompeiano. al di sopra vi sono diversi strati antropizzati con materiale ceramico databile per lo più al iv e v secolo d.c., sebbene vi siano alcuni frammenti di iii secolo. gli strati antropizzati si chiudono con una sepoltura di un bambino (maschio, intorno ai 6 anni), coperta da due strati con ceramica. il rinvenimento all’interno della sepoltura di una moneta datata al 450-457 d.c. offre il terminus post quem per l’intera sequenza. gli strati antropizzati sono infatti sigillati, a partire da una quota di circa 87,37 m., dal riempimento costituito da litici immersi in una matrice cineritica grossolana (fig. 3: a1). la lettura della sequenza continua all’interno del saggio 04 (fig. 6), dove si individua una successione di strati di cenere grigia con litici, intercalati ai quali si distinguono livelli di cenere bianca. al di sopra è un sottile paleosuolo (fig. 3: p2; spess. < 10 cm, h. 89,06 m. s.l.m.), all’interno del quale sono gusci di gasteropodi polmonati. al di sopra vi sono alcuni strati costituiti da materiale vulcanoclastico rimaneggiato. vi sono poi almeno due battuti a matrice sabbiosa, sui quali è posto l’accumulo di materiale di spolio dalle strutture circostanti: lo strato è composto da blocchetti informi di varie dimensioni costituiti prevalentemente da lava, calcare, cruma e pochissimi laterizi compattati con malta. tale strato è utilizzato verosimilmente per rialzare il piano di calpestio antico, sul quale viene poi impostata una struttura dal carattere provvisorio (forse un forno). tale osservazione è tanto più interessante se legata all’analisi del riempimento vulcanico presente nel saggio 02, al di sotto del cosiddetto forno. lo scavo all’interno di questo saggio ha infatti permesso di notare come al di sotto della fondafig. 5 pianta schematica del sito archeologico con indicazione dei saggi. schematic map of the archaeological site with excavation trencheshighlighted fig. 6 vista del saggio 04 da sud con indicazione dello strato in cui sono stati rinvenuti i gusci di lumache. view from south of the test trench 04 with indication of the context in which landsnail shells were found. episodi vulcanici e vulcanoclastici ... 58 zione del forno vi sia uno strato a matrice cineritica grossolana con notevole presenza di lapilli (unità a). tale strato era sigillato, come per l’analogo nel saggio 04, da un sottile paleosuolo con all’interno gusci di gasteropodi polmonati. tale strato si trova però ad una quota più elevata rispetto all’altro di circa 1 metro (90,13 m. s.l.m.). il saggio 01 (fig. 7) consente di ricostruire la sequenza stratigrafica dall’unità a alle più recenti. alla base dello scavo affiorano i livelli da a7 ad a9 sigillati da un sottile strato con reperti malacologici, rinvenuti alla stessa quota del saggio 02 (90,04 m.). segue uno strato antropizzato con macerie (forse un accumulo di materiale). al di sopra vi è uno strato vulcanico a matrice cineritica (unità b), che si estendeva per tutta l’ampiezza del saggio. a una lettura strettamente stratigrafica, mostra tre differenti livelli di sovrapposizione: il primo caratterizzato da una matrice sabbiosa, di colore grigio; il secondo con matrice cineritica con struttura lenticolare data dalla presenza di frustuli carboniosi, di colore nero alternati a tracce di concrezioni calcaree; infine il terzo costituito da uno strato di cenere compattata di colore grigio scuro. lo strato si trova a circa 91 m. alla stessa quota si rinvengono i resti dei materiali vulcanici pertinenti alla stessa eruzione nel saggio 02. al di sopra vi è uno strato di terreno nero a matrice cineritica, che costituisce un sottile paleosuolo. segue il crollo di uno dei muri del secondo livello dell’edificio. su di esso sono due strati a matrice argillosa di colore bruno con rari laterizi, a costituire un paleosuolo. seguono alcuni strati a matrice vulcanica intercalati a paleosuoli. il saggio 03 consente di verificare solo l’ultima parte della sequenza messa in luce nel saggio 01. non è stato possibile infatti approfondire il saggio di molto, data la presenza di un enorme crollo di un muro, che costituiva probabilmente uno dei muri del secondo livello dell’edificio. tale crollo, come per il simile nel saggio 01, poggia anch’esso sui depositi dell’unità b. 5. definizione delle unità eruttive e meccanismi di deposizione la presenza di sette paleosuoli indica dei periodi di stasi, più o meno lunghi, che si alternano a ripetuti episodi di seppellimento. all’interno della sequenza dei depositi descritti precedentemente è importante discriminare quelli di origine vulcanica primaria, cioè messi in posto in conseguenza di un’eruzione vulcanica, da quelli rimaneggiati, essenzialmente causati da rimobilizzazioni di materiale vulcanico incoerente sui pendii del vulcano. i depositi vulcanici primari, confinati tra due paleosuoli, costituiscono il prodotto di un’unica unità eruttiva e sono quindi associati, sulla base delle loro caratteristiche litostratigrafiche ad un’eruzione storica vesuviana. unità a – il ritrovamento durante le operazioni di scavo di una moneta datata intorno al 450-457 alla base dell’unità a consente di associare questi depositi all’eruzione del 472 d.c. i depositi che formano quest’unità sono di origine vulcanoclastica come suggeriscono caratteri quali: la relativa litificazione ed il carattere eterolitico delle particelle con una prevalenza di clasti di origine lavica di diversa natura. tale interpretazione è fortemente suffragata dal ritrovamento all’interno della successione di juvenili pomicei non presenti nei depositi primari da corrente piroclastica di questa eruzione, dove i soli juvenil i presenti sono scorie dense (sulpizio et al., 2005). la sequenza di questi depositi stratificati indica la messa in posto di successivi debris f low durante una fase di rimobilizzazione della copertura piroclastica (livelli pomicei) ed erosione del substrato lavico avvenuta durante l’eruzione del 472 d.c. la presenza di depositi epiclastici a tetto dei depositi primari dell’eruzione del 472 d.c. in altri siti del settore settentrionale del vesuvio (perrotta et al., 2006) e della piana campana (mastrolorenzo et al., fig. 7 sezione nord del saggio 01. north section of the test trench 01 g.f. de simone et al. 2002), suggerisce che tale rimobilizzazione sia avvenuta durante le fasi finali dell’eruzione. questi depositi sono coperti da un sottile paleosuolo osservato con discontinuità nell’area di scavo. unità b – la presenza di un suolo così poco sviluppato suggerisce che i prodotti dell’unità b siano stati messi in posto dopo un breve periodo di quiete successivo all’eruzione del 472 d.c. e potrebbero quindi essere associati con l’eruzione del 512 d.c. questo deposito è formato da livelli cineritici stratificati che presentano una evidente componente erosiva che permette di ipotizzare una origine da corrente piroclastica. unità c – è un deposito stratificato a matrice cineritica in cui sono dispersi clasti juvenili (scorie, pomici bianche e grigie) e litici. il cattivo assortimento, la presenza di superfici erosionali e la natura eterolitologica dei componenti juvenili indica che questi depositi rappresentano una ulteriore fase di rimaneggiamento della coltre piroclastica rimobilizzata dai pendii del monte somma. unità d, e, f, g – sono sottili livelli piroclastici da caduta probabilmente associati ad eruzioni medioevali. in particolare il livello scoriaceo e potrebbe essere il prodotto di una delle fasi dell’eruzione vesuviana del 1631. 6. discussione e conclusioni il sito romano di pollena trocchia, anche se solo parzialmente scavato, fornisce importanti indicazioni sulla successione di eventi vulcanici accompagnati o intervallati da consistenti rimobilizzazioni della coltre piroclastica che hanno interessato l’area a nord del vesuvio. se consideriamo il rapporto tra lo spessore cumulativo di depositi di lahar e quello dei depositi piroclastici (5/1) possiamo immediatamente dedurre quale sia stata l’importanza relativa dei due fenomeni. a differenza delle famose città di pompei ed ercolano, completamente sepolte dai prodotti dell’eruzione del 79 d.c., questo edificio è stato sepolto essenzialmente da depositi vulcanoclastici (lahar) che si sono succeduti dal v secolo fino al 1631. le eruzioni vesuviane più che produrre dei danni diretti hanno fornito enormi quantità di materiale incoerente che è stato rimobilizzato sugli acclivi pendii del monte somma a seguito di intense piogge. queste osservazioni confermano lo scenario proposto da perrotta et al. (2006b) per l’area di somma vesuviana in cui l’impatto di eventi secondari (lahar) post 79 d.c. risulta la principale causa di distruzione e successivo seppellimento di un monumentale edificio romano. i dati provenienti da questo nuovo scavo enfatizzano l’importanza che eventi di tipo lahar hanno avuto in tutto il settore settentrionale del vulcano. dal punto di vista archeologico questo scavo è l’unico finora noto nel quale si trova un chiaro segno di reinsediamento successivo all’eruzione del 472, sigillato poi dall’eruzione successiva (512?). le prossime campagne di indagine saranno utilizzate per definire in modo particolareggiato gli effetti delle singole fasi eruttive e degli episodi vulcanoclastici sull’edificio. inoltre, l’approfondimento di un saggio di scavo sotto il piano pavimentale romano (pre-ii secolo d.c.) potrebbe fornire un fondamentale contributo per definire se e con quali effetti i prodotti dell’eruzione del 79 d.c. hanno interessato quest’area. ringraziamenti si ringraziano tutti i partecipanti al progetto ed in particolare le responsabili: jaime bartlett, rossella cannella, monica lubrano e caterina martucci. riferimenti bibliografici albore livadie c., mastrolorenzo g. & vecchio g. (1998) eruzioni pliniane del somma-vesuvio e siti archeologici dell’area nolana – in: guzzo, p.g. & peroni, r. (eds.), archeologia e vulcanologia in campania. atti del convegno, pompei 21 dicembre 1996 (napoli: arte tipografica), pp. 39-86. aoyagi m. (2005) h eπαυλη του aυγυστου στη somma vesuviana (la vil la di augusto a somma vesuviana) – in: cevoli, t. (ed.), πομπηια. η θαμμενη πολη (atene: corpus), pp. 140-143. aoyagi m., angelelli c. & matsuyama s. (2006) lo scavo della cd. vil la di augusto a somma vesuviana (na). campagne 2002-2004 rendiconti pontificia accademia, lxxviii, pp. 75109. aoyagi m., mukai t. & sugiyama c. céramique de l’antiquité tardive d’un site romain de somma vesuviana, italie -– in: bonifay, m. & tréglia, j.-c. (eds.), lrcw 2. late roman coarse wares, cooking wares and amphorae in the mediterranean: archaeology and archaeometry, vol.1 (oxford: archaeopress, 2007), pp. 439-449. cerulli irelli g. (1975) intorno al problema della rinascita di pompei in: andreae, b. & kyrieleis, h. (eds.), neue forschungen in pompeji und den anderen vom vesuvausbruch 79 n. chr. verschütteten städten (recklinghausen: bongers), pp. 291-298. cioni r., sbrana a. & gurioli l. (1996) the deposits of ad 79 eruption in: cev-cmvd workshop on vesuvius decade volcano, september 1996, naples, pp. 17-23. colucci pescatori g. (1986) osservazioni su abellinum tardo-antica e sull’eruzione del 472 d.c. in: tremblements de terre, éruptions volcaniques et vie des hommes dans la campanie antique (napoli: centre jean bérard institut français de naples), pp. 121-133. de carolis e. (1997) testimonianze archeologiche in area vesuviana posteriori al 79 d.c. archeologia, uomo e territorio. rivista dei gruppi archeologici d’italia, 16, pp. 17-32. de franciscis a. (1976) pollena trocchia in: the princeton encyclopedia of classical sites (princeton: princeton university press), p. 721. de simone a. & nappo s.c. (eds.) (2000) mitis sarni opes. nuova indagine archeologica in località murecine (napoli: denaro). de simone a. (2002) villa arianna: configurazione delle strutture della basis villae in: bonifacio, g. & sodo, a.m. (eds.), stabiae: storia e architettura. 250° anniversario degli scavi di stabiae 17491999 (roma: l’erma di bretschneider), pp. 41-52. de simone g.f. (2007) oltre la costa: il problema delle ville nell’entroterra vesuviano in: ciardiello, r. (ed.), la villa romana (napoli: orientale editrice), 59episodi vulcanici e vulcanoclastici ... pp. 241-255. de simone g.f. (2008) il territorio nord-vesuviano e un sito dimenticato di pollena trocchia cronache ercolanesi, 38, pp. 329-349. de simone g.f. & macfarlane r.t. (eds.) (2009) apolline project vol.1: studies on vesuvius’ north slope and the bay of naples (napoli: università degli studî suor orsola benincasa napoli brigham young university). de simone g.f. & matsuyama s. (2006) new light on the ‘dark side’ of vesuvius herculaneum archaeology, 4, p. 5. della corte m. (1932) somma vesuviana. ruderi romani notizie degli scavi di antichità, pp. 309310. ebanista c. (2003) dinamiche insediative nel territorio di cimitile tra tarda antichità e medioevo in: brandenburg, h. & ermini pani, l. (eds.), cimitile e paolino di nola: la tomba di s. felice e il centro di pellegrinaggio: trent’anni di ricerche (città del vaticano: pontificio istituto di archeologia cristiana), pp. 43-86. luongo g., perrotta a. & scarpati c. (2003a) impact of the ad 79 explosive eruption on pompeii, i. relations amongst the depositional mechanisms of the pyroclastic products, the framework of buildings and the associated destructive events journal of volcanology and geothermal research, 126, pp. 201-223. luongo g., perrotta a., scarpati c., de carolis e., patricelli g. & ciarallo a. (2003b) impact of the ad 79 explosive eruption on pompeii, ii. causes of death of the inhabitants inferred by stratigraphic analysis and areal distribution of the human casualties journal of volcanology and geothermal research, 126, pp. 169-200. mastrolorenzo g., palladino d.m., vecchio g. & taddeucci j. (2002) the 472 ad pollena eruption of somma-vesuvius (italy) and its enviromental impact at the end of the roman empire journal of volcanology and geothermal research, 113, pp. 19-36. pagano m. (1988) pollena trocchia. rinvenimento di strutture romane del ii secolo d.c. rivista di studi pompeiani, ii, pp. 244-245. pagano m. (1991) pollena trocchia. scavo in località masseria de carolis e ricognizioni nel territorio comunale rivista di studi pompeiani, v, pp. 231-236. pagano m. (1995) l’area vesuviana dopo l'eruzione del 79 d.c. rivista di studi pompeiani, vii, pp. 3544. pappalardo u. (2001) vesuvio. grandi eruzioni e reinsediamenti in: lo cascio, e. & storchi marino, a. (eds.), modalità insediative e strutture agrarie nell’ ital ia meridionale di età romana (bari: edipuglia), pp. 435-53. perrotta a., scarpati c. & luongo g. (2006a) volcaniclastic resedimentation on the northern slope of vesuvius as a direct response to eruptive activity landslides, 3, pp. 295-301. perrotta a., scarpati c., luongo g. & aoyagi m. (2006b) burial of emperor augustus’ villa at somma vesuviana (italy) by post-79 ad vesuvius eruptions and reworked (lahars and stream flow) deposits journal of volcanology and geothermal research, 158, pp. 445-66. pisapia m.s. (1981) l’area ercolanese dopo l’eruzione del 79: evidenze archeologiche. la necropoli di via doglie ad ercolano rendiconti della accademia di archeologia, lettere e belle arti, napoli, 56, pp. 63-74. sigurdsson h., carey s., cornell w. & pescatore t. (1985) the eruption of vesuvius in ad 79 national geographic research, 1, pp. 332-387. soricelli g. (1997) la regione vesuviana dopo l’eruzione del 79 d.c. athenaeum, 85, pp. 139-154. soricelli g. (2001) la regione vesuviana tra secondo e sesto secolo d.c. in: lo cascio, e. & storchi marino, a. (eds.), modalità insediative e strutture agrarie nell’italia meridionale di età romana (bari: edipuglia), pp. 455-472. stefani g. (2000) le ville rustiche del territorio vesuviano in: casali di ieri casali di oggi. architetture rurali e tecniche agricole nel territorio di pompei e stabiae (napoli: arte tipografica), pp. 13-19. stefani g. (ed.) (2002) uomo e ambiente nel territorio vesuviano. guida all’antiquarium di boscoreale (ercolano: marius). 60 ms. ricevuto il 20 marzo 2008 testo definitivo ricevuto l’11 febbraio 2009 ms. received: march 20, 2008 final text received: february 11, 2009 g.f. de simone et al. << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /none /binding /left /calgrayprofile (dot gain 20%) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /error /compatibilitylevel 1.4 /compressobjects /tags /compresspages true /convertimagestoindexed true /passthroughjpegimages true /createjdffile false /createjobticket false /defaultrenderingintent /default /detectblends true /colorconversionstrategy /leavecolorunchanged /dothumbnails false /embedallfonts true /embedjoboptions true /dscreportinglevel 0 /emitdscwarnings false /endpage -1 /imagememory 1048576 /lockdistillerparams 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and mediterranean quaternary, 26 (2), 2013, 101-109 the pollen record of the 190 m core fersina 2, an entirely late-glacial sediment sequence in the adige valley at trento (ne italy). eberhard grüger 1, giulio morteani 2 1) dep. palynology & climate dynamics, albrecht von-haller institute plant science, georg-august-univ. of göttingen, germany 2 gmain 1, 84424 isen, germany . corresponding author: e. grüger <egruege@gwdg.de> abstract: pollen analysis of samples taken from the core of the water well fersina 2 (adige valley, prov. trento, ne italy) did not reveal any indication of an interglacial or holocene age of the uppermost 190 m in the sediment sequence deposited in the over-deepened adige river valley. the sediment sequence dates entirely from late-glacial times. four radiocarbon ages of pieces of wood indicate that about 165 m of the upper part of the profile are of younger dryas age. the lower part of the sequence dates from the allerød or bølling/allerød and a preceding cold phase, probably the oldest dryas. accordingly the deposition of the sequence took about 2500 or 3500 years and was completed long before the onset of the neolithic. our results are in excellent agreement with findings in other formerly glaciated alpine valleys (e.g. the traun, salzach and enns valleys in the northern alps). the final depth of the fersina 2 well is 190 m. it is very likely that the sediment sequence found below this level in the nearby 423 m deep fersina 1 well was also deposited after the deglaciation of the adige valley at the end of the last glacial period. key words: trentino, adige valley, fersina, younger dryas, stratigraphy, pollen analysis 1. introduction a fairly large number of pollen studies are available on the late-glacial and holocene vegetational development in the italian alps and the apennine mountains (e.g. vescovi et al., 2010; drescher-schneider, 2009; ravazzi, 2007; ravazzi et al., 2007; vescovi et al., 2007; filippi et al., 2007; ravazzi et al., 2006; pini, 2002; grüger, 1968; beug, 1964; etc.). these studies can help to date a series of pollen-bearing sediment samples from the 190 m deep water well fersina 2 drilled in the city area of trento (north-eastern italy). the location of the coring site on the bottom of the adige river valley at an elevation of only about 200 m, the remarkable length of the core, and the fact that the sediment is lacustrine all combine to promise information about the development of the vegetation of the trentino (southern alps) since the deglaciation of the adige valley at the end of the würmian glacial period. the results of the pollen study are presented below. regional geology and sedimentology of the core sediments are from fuganti et al. (1998, 2001). tab. 1 shows how the late-glacial biozones (based on biological phenomena) correlate with grip zones (based on greenland ice core events). this system is increasingly used in more recent scientific publications on northern italy. 2. geographical situation, pollen source area and sedimentary environment almost all of the modern catchment area of the adige and its tributaries (more than 10,000 km2) was glaciated during the maximum of the last glacial period (würmian). when the ice margin of the adige valley glacier retreated to the north from its southernmost position south of trento, a vast lake formed in the overdeepened adige valley (e.g. venzo, 1957). it must have been many km long, and it was probably as wide as the fig. 1 a) position of the lake garda area (black square) in italy. b) lake garda area. sediment core sites mentioned in the text marked by encircled dots, elevations given in meters above mean sea level. the broken line delimits the southern border of the würmian moraines south of lake garda. c) the alluvial fans of the trento area (from venzo 1957, changed), f = profile fersina 2 (this paper), p3 = site studied by venzo (1957). the non-shaded part of the inset marks the more or less flat, late-glacial bottom of the narrow adige valley. adige valley. this lake was still in existence when the younger dryas glaciers which did no longer reach the trento area melted down. huge amounts of melt water were available at that time to transport an enormous sediment load to the south and thus to fill up the overdeepened adige valley. in the trento area much of the infill material was contributed by the torrente fersina. this river, originating in the dolomites, enters the adige valley in the area of the city of trento and cascades down from a hanging valley about 200 m above the bottom of the modern adige valley (fig. 1) forming an alluvial fan there on which part of the older quarters of the city of trento and the fersina coring site are located. the combined sediment input of fersina and adige caused an extraordinarily high sedimentation rate and thus a rapid filling-up of the vast lake basin. the stratigraphy of the fersina cores (fig. 2) shows that predominantly clay and silt, but also fine sand and some sandy gravel, were deposited in the trento area. in the study area the adige valley is bordered to the west and east by mountain ranges rising to more than 2000 m. the area is consequently characterized by a much diversified altitudinal zonation of the vegetation, including treeless alpine meadows. the pollen produced in these varied vegetational zones was brought to the coring site probably predominantly by the wind. nonanemogamous species, even components of the bankside vegetation, had almost no chance to be represented in the sediment as the later coring site was probably about 1 km away from the nearest lake shore. additional pollen was transported to the trento lake basin by the rivers from more distant regions, contemporary pollen and possibly also pollen reworked from older sediment well upstream from the coring site. an unknown quantity of the pollen floating on or suspended in the lake water was carried away with the excessive river water. due to the great sedimentation rate (see below), complete mixing of the annual input of sediment might have been impossible. if so, the pollen contents even of different subsamples of the same annual layer might differ to some degree. from the above, it follows that the sedimentary environment of the fersina core was so different from that of smaller lake basins and peat bogs the usual source of information on the former vegetation and of its changes that a direct comparison of pollen values – especially of less frequent taxa must not be done. the main features of the vegetational development, however, will remain visible despite loss of pollen and inadequate size of samples. 3. sampling the well fersina 2 was drilled (percussion drill) in march/april 1997 in the southern part of trento near the present-day confluence of the rivers fersina and adige (46° 02’ 50” n, 11° 07’ 08.5” e; 190.6 m a.s.l.). the drilling was ended at a depth of 190 m when the aquifer was reached. a continuous casing was used during drilling to prevent collapse of the well walls and hence incorporation of younger sediment in the samples. therefore disturbances of the sedimentary and pollen record can be excluded. the samples were labelled according to the sampling interval of about 1 meter. a grüger e., morteani g. 102 table 1 correlation of late-glacial grip zones and swiss biozones according ammann et al., 2012 and van raden et al., 2012. table 2 calibration of the conventional radiocarbon dates from trento and wiggle matching of the fersina 2 dates. 103 f ig . 3 p ol le n di ag ra m . t he p ol le n va lu es a re s ho w n as p er ce nt ag es o f th e po lle n to ta l. p ol le n su m , po lle n co nc en tr at io ns , an d am ou nt s of s to m at a ar e gi ve n as n um be rs . n ot e th at t he s ca le s ch an ge in or de r to s av e sp ac e. d ot s de no te w he re t he p er ce nt ag e va lu es a re ≤ 0 .3 o r w he re o nl y on e st om a of p in us w as fo un d. r ad io ca rb on d at ed le ve ls : i : 11 50 0 ± 15 6 ca l a b p ; i i: 1 16 53 ± 2 14 c al a b p ; i ii: 1 21 09 ± 2 23 c al a b p ; iv : 12 37 9 ± 16 6 ca l a b p . f ig . 2 s tr at ig ra ph y of t he c or es f er si na 1 an d f er si na 2, de si gn by a . f ug an ti, ch an ge d by g . m or te an i an d c . p re in fa lk , de pt hs of po lle n sa m pl es ad de d by e . g rü ge r. …. fersina 2, an entirely late-glacial sediment sequence ….. sediment sample called, e. g., “37 m” represents the sediment found between 36 and 37 m depth. in total, 100 irregularly shaped lumps of sediment (100 to 200 cm3) were available for pollen analysis. all samples consist of white silt, clay, and fine sand. the well fersina 1, located some 36 m from fersina 2, was drilled in the same year. this drilling was stopped at 423 m without yet having reached bedrock. no pollen samples are available from this well, but the huge thickness of the sediment clearly shows that the adige river valley was over-deepened at least up to trento. fig. 2 shows the stratigraphy of the cores fersina 1 and 2 (fuganti et al., 2001 and own data). 4. radiocarbon dating / wiggle matching four pieces of wood found in the fersina 2 sediment were radiocarbon dated (table 2). the resulting conventional and calibrated radiocarbon ages were published by fuganti et al. (1998). since an improved calibration data set is now available (reimer et al., 2009), the radiocarbon ages from trento were re-calibrated using the calpal software (weninger & jöris, 2008). following a proposal of m. geyh, the former director of the hannover radiocarbon laboratory, the radiocarbon ages of the four pieces of wood were submitted to “wiggle matching”, kindly carried out by b. weninger (university of cologne). to accomplish wiggle matching, a calendric distance of 10 ± 50 calyrs was assumed for the two younger pieces of wood, and a distance of 90 ± 50 calyrs for the two older pieces. thus fitted into the calcurve, radiocarbon ages of 11,603 ± 146 cal a bp (final year) and of 12,281 ± 142 cal a bp (final year) result for the two pairs of pieces of wood. 5. pollen analysis 5.1. pollen preparation and pollen diagram the aliquots for pollen analysis (2.3 to 14 cm3, average 5.2 cm3) were taken in the laboratory from the inner part of the cored material to prevent contamination with recent pollen. the standard mode of sample preparation, with hcl and hf and wet ultrasonic sieving as the final step (width of mashes 8 µm), did not produce a pollen concentration sufficient for a reliable pollen count. treatment with hcl and naoh, followed by flotation with sodium tungstate solution (na2wo4, d = 2.05) as described by eisele et al. (1994), but without acetolysis, proved to be more effective. to allow the calculation of pollen concentrations, one lycopodium spore tablet (containing 10,679 ± 191 spores) was added to each pollen sample at the beginning of the treatment (stockmarr, 1971). the pollen counts range from 204 to 1225 (mean 592) grains per sample. four samples only contained fewer than 484 pollen grains. the complete results of pollen analysis are presented in fig. 3 and table 3. supplementary data are available at doi:10.1594/pangaea.793027. the pollen diagram was drawn using panplot (diepenbroek et al., 2001), with graphical details being improved with microsoft paint. all given pollen values are percentages of the pollen total. 5.2. the pollen record the salient feature of the pollen diagram (fig. 3) is the dominance of the pinus sylvestris type in all pollen spectra (88.4 to 34.3 %, mean 71.5 %). next in frequency are the pinus cembra type (8.8 to 1.3 %, mean 5.1 %) and betula (1.5 to 18.3 %, mean 5.2%). all other tree pollen types were found less frequently; indeed, their pollen values rarely exceed 1%. tree species with such low pollen values – among them the thermophilous tree species – can hardly have been of any importance in the area or were even missing when the profile fersina 2 was deposited. but pine trees occurred in the area, as evidenced by pinus stomata being present in 14 out of 17 samples. temporary increases of the nap (nonarboreal pollen) values combined with a frequent 104 grüger e., morteani g. table 3 rare pollen and spore types (numbers). occurrence of pollen grains of shade intolerant species indicate former changes of the vegetation. details will be discussed in the following. the two lowermost samples (185 and 186 m) are comprised of clay. they show the highest nap values recorded in the pollen diagram (21.3 and 39%, respectively). up to 12.7 % of the pollen total was produced by the shade intolerant genus artemisia. artemisia species never occur in a forest. the same is true for the chenopodiaceae (9.8 and 5.3 %). the percentages of the indeterminable pollen types (indeterminata), certainly not pollen of woody species, are high (11.1 and 6.6 %). the diversity of nonarboreal pollen types (nap) was never greater than at the time of deposition of these two samples. among the woody taxa, the pollen frequencies of the pioneer shrub hippophae (7.4 and 13.3 %), of juniperus (0.4 and 0.6 %), and of two ephedra -pollen types (up to 1 %) are of special interest. these shrubs are sunlight-demanding and cannot thrive in the shade of trees. on the other hand, no other sample of the profile contains more pollen of picea (2.0 and 2.2 %), corylus (0.8 and 1.0 % not much for this shrub!), and ulmus (0.4 and 0.6 %) than these two samples. pollen of quercus and tilia was not found. pollen concentration is medium in sample 185 m, but very low in sample 186 m (see fig. 3). a low pollen concentration is caused either by the absence of pollen-producing plants or by a high rate of sedimentation. never during the deposition of the fersina 2 sediment was the vegetation around the coring site more open and the climatic conditions less favourable than at the time when the clay below the sandy gravel (i.e. below 184 m, fig. 2) was deposited. the region was not forested, but was probably not treeless. the pine values are lower than further up in the profiles, but – together with the occurrence of one stoma of a pine needle – possibly sufficiently high to assume the presence of some pine trees in the area. the comparatively high values of picea, ulmus and corylus are somewhat confounding. it is possible that these pollen grains come from the reworking of older sediments. the presence of the mentioned species in the area is unlikely in view of the reconstructed situation. the pollen spectra of the samples 172 and 171 m, taken in a layer of sandy gravel (fig. 2), indicate warm conditions during the time of their sedimentation. high pine pollen sums (91.3 and 89.3 %), the very low nap values (1.9 and 3.3 %), and the only occasional occurrence of pollen grains of shade intolerant taxa indicate that the region was forested when the two samples were deposited. pollen of the thermophilous trees quercus and ulmus is rare. on the other hand, tilia cordata-type pollen is in no sample more frequent than in sample 171 m (1.8 %). the pollen spectrum of sample 161 m, taken from sandy gravel, shows with 5.2 % artemisia, 3.9 % chenopodiaceae, 8.2 % indeterminata, and a nap sum of 21.5 % pointing to a return to climatic conditions similar to those prevailing when the clay of samples 185 m and 186 m was deposited. evidently the forest had disappeared again. only a few tree specimens may have been left in the area. it is remarkable that in this sample the prequaternary reworked sporomorphs reach their absolute maximum, probably a result of intensive erosion of prequaternary pollen-bearing sediments by the rivers fersina and adige. consequently the pollen concentration is low. with only 396 pollen grains per 1 cm3 of sediment it is the lowest concentration value in our series of samples. the samples 154 m (sandy gravel) (fig. 2), 139 and 124 m (silty clay with sandy levels) document, with nap values around 10 % and the occurrence of shade intolerant taxa, climatic conditions that were similar, although probably somewhat less severe, than those indicated by the pollen preserved in the lower part of the profile, below and above the 171 and 172 m samples (see above). pieces of well-preserved wood prove the presence of pinus cembra (sample 130 m) and of pinus mugo/sylvestris (sample 139 m) in the region. the two pieces of wood were radiocarbon dated by wiggle matching to 12,280 ± 142 cal a (table 2). after the deposition of sample 124 m, the ecological situation changed markedly. starting with sample 114 m, the nap values are distinctly lower than before (mostly less than 5 %). pinus stomata are more frequent. pollen of hippophae and artemisia, although present in all but one (hippophae) and three (artemisia) of the 17 studied samples, is rare. ephedra pollen was found in two of the nine pollen samples above the 124 m level only (3 pollen grains). these changed conditions lasted throughout all the time represented by the rest of the profile. birch was probably present. pollen of thermophilous deciduous trees like quercus, ulmus, and tilia is recorded as before, with variable, but low, values. a few specimens of these trees only can have grown in the vicinity if their pollen grains did not come with the wind from more distant sites or was reworked. in a layer of sand two pieces of juniperus wood (samples 32 and 33 m), but no pollen grains of this shrub, were found. the radiocarbon age of the two pieces of wood is 11,603 ± 146 cal a bp (wiggle matching, table 2). 6. discussion 6.1 the age of the sediment of the fersina 2 well – general remarks the deposition of the lacustrine sediment studied can have started only after the retreat of the adige glacier to the north beyond the trento area. the sediment met by the fersina 1 and 2 wells can therefore be of late -glacial up to postglacial age only. the following dating relies on pollen analyses and on four radiocarbon dates. pollen analytical dating is based on the fact that most european tree species and important groups of herbs are anemogamous. because such plants let the wind disperse their pollen grains, pollen diagrams of large areas are usually similar to each other. therefore, a new profile can usually be dated by comparing the composition of its pollen assemblages and their changes with that of other not-toodistant, reliably dated pollen sequences. the sampling sites next to trento with pollen dia 105 …. fersina 2, an entirely late-glacial sediment sequence ….. grams suitable for a comparison with the fersina pollen data are mentioned below and are shown in fig. 1. they are not the only pollen diagrams from this area, but the others are not detailed enough to be useful for our purpose, e.g. the preliminary diagram (with only seven pollen curves) from a peat profile at isera near rovereto, about 20 km south of trento in the adige valley (calderoni et al., 1996) and kofler’s diagrams from bondone and lago delle buse (kofler, 1994). 6.1.1 the postglacial three detailed pollen analytical studies from the trento area are available to answer the question whether the fersina 2 profile can be of postglacial age. two of the studied profiles come from filled-up lakes (grüger, 1968), namely bondone, at 1550 m, only 8 km southwest of trento, and fiavè, at 654 m, about 25 km off trento, west of bondone. the third profile is from the extant lake of lavarone, at 1115 m, about 20 km southeast of trento (filippi et al., 2007). the most remarkable event during the early postglacial was the expansion of the thermophilous deciduous tree genera quercus, ulmus, tilia, fraxinus, and acer and of corylus during the preboreal (11,500 to 10,200 cal a bp), the first biozone of the postglacial. although the center of the distribution of these species lies in the lower altitudinal zones, the sum of their pollen values rises at fiavè (at 654 m) from low values to 30%, at lavarone (1115 m) to 25 %, and to around 10% further up at bondone (1550 m). it should be expected that the contemporary sedimentation in the adige valley produced, at least in the uppermost part of the profile fersina 2, values not less than those found at fiavè and lavarone; but the fersina pollen data are mostly much lower. in 11 of the 17 studied samples the pollen values of the thermophilous deciduous tree genera are ≤ 1%, and in a further four samples between 1 and 2%. only in samples 124 and 139 m are higher percentages reached (4.3 and 3.5 %, respectively, mainly oak pollen). these two samples can, however, not be of postglacial age if the results of the radiocarbon dating are accepted. also no hints can be found in the fersina 2 pollen diagram of later important vegetational events like the immigration and spreading of fagus and abies trees, which were present in the area from about 8000 cal a bp. the pollen curve of fagus, an important constituent of the montane forests, climbs to more than 40 % of the tree pollen sum at lavarone and to more than 10 % at bondone, and abies reaches more than 15 % at both localities (j. grüger, unpublished, counts available under http://doi.pangaea.de/10.1594/pangaea.763901). in the fersina 2 samples, not a single pollen grain of fagus, and only one pollen grain of abies have been found. evidently no part of the fersina 2 pollen diagram shows characteristics of the holocene forest development. no section of the profile fersina 2, the uppermost sandy gravel included, can be of postglacial age. the sediment of the entire fersina 2 profile must have been deposited during late-glacial times, with the only exception of the colluvial material forming the modern surface in the area, a layer being too thin to be shown in the stratigraphical scheme (fig. 2). 6.1.2 the late-glacial the younger dryas, the final part of the last glacial period, started around 12,700 cal a bp; it ended when the holocene vegetation began to develop in the study area about 11,600 to 11,500 cal a bp (vescovi et al., 2007). the radiocarbon ages of the four pieces of pine and juniper wood found in the fersina 2 sediment (table 2) prove that these tree species had been growing in the study area during younger dryas times. being well preserved, these pieces of wood were probably not repeatedly transported, exposed, and temporarily embedded, so they most likely date the sediment in which they were discovered. if so, at least the part of the core between 32 and 139 m must be of younger dryas age. the pollen spectra of the samples 3, 14, and 24 m do not distinctly differ from those of proven younger dryas age below. apparently a younger dryas type of vegetation was still present in the trento area when the uppermost 30 m of sediment (mainly sandy gravel) were deposited so that this sediment can hardly be of postglacial age. the radiocarbon age of the upper piece of wood (table 2) allows, however, a deposition time of a few decades only so that a huge annual sedimentation rate must be assumed. to explain this one must not assume a climatic change, it is sufficient to consider the special conditions of sedimentation on an alluvial fan. rivers usually shift over their alluvial fans. where they flow they can accumulate huge amounts of sediment in a short time. the coarseness of the uppermost sediment indicates that at the time of the deposition of this material the river fersina flowed and dropped its sediment load where the fersina core was taken. thus the thickness of the uppermost layer of sandy gravel cannot be used as an argument against a younger dryas age of this part of the profile as proposed by the pollen data. younger dryas vegetation is documented in the profile downwards to sample 161 m. the next older pollen spectra (171 and 172 m) indicate distinctly warmer, though not interglacial, conditions. these spectra can only be of allerød age. samples 185 and 186 m, the oldest samples of the fersina 2 profile, contain a pollen flora which indicates cold conditions. this climatically unfavourable period can either be the colder middle part of the allerød or one of the preceding cold phases of the late-glacial, namely the older dryas or the oldest dryas. the allerød is a tripartite interstadial, that is, it has a climatically less favourable phase sandwiched between warmer phases at its beginning and before its end. the cooler phase, called the gerzensee oscillation, lasted a few hundred years only (250 years according to greenland ice core isotope data, grip zone gi-1b, björk et al., 1998, or 400 years according to swiss lake sediment isotope data, schwander et al., 2000). although distinct in the oxygen isotope records, only a weak reaction of the vegetation is recorded by the pollen data. in switzerland (sites gerzensee and leysin; wick, 2000) and western germany (site meerfelder maar; stebich, 1999), a decrease in the importance of betula pollen (percentages as well as concentrations and influx) is the most indicative reaction. the more 106 grüger e., morteani g. thermophilous vegetation growing at that time in tuscany, 340 km south of trento (lago dell’accesa, drescher-schneider et al., 2006), however, responded distinctly to the changed conditions as is clearly indicated by lowered quercus and higher nap (mainly poaceae) values, and by a series of minor changes of a few further pollen curves (accesa ii oscillation). the pollen diagrams from the trento area, bondone, fiavè (grüger, 1968) and lavarone (filippi et al., 2007) do not show any indication of a climatic deterioration during the allerød, probably as no plant species requiring higher temperatures were present at that height and were at best rare at lower altitudes. the pollen diagram of saltarino sotto only, a low-lying site (194 m) 75 km southwest of trento near lake garda (grüger, 1968), shows changes in the allerød time samples (320 cm and 325 cm) which most likely are the expression of a cooler climate. betula values diminished by about 9 %, while nap (about 10 %, mainly poaceae and artemisia) and juniper values (>1 % instead of 0.4 % before and 0.8 % after the oscillation) increased. the rise of the qm (quercetum mixtum) curve – here mainly oak – stopped, but the rise continued when the climatic conditions improved, so that qm values of 30% were reached at the end of the allerød. the qm values dropped to a much lower level during the following younger dryas stadial. considering the weak response of the vegetation around saltarino sotto to the gerzensee oscillation, it appears unlikely that the change from forest (samples 171 and 172 m) to an open type of vegetation (185 and 186 m) at trento was caused by this climatic deterioration. consequently, part of the lower sandy gravel (fig. 2) must represent the entire allerød, the bølling possibly included, interstadials during which the annual sedimentation rate was apparently much reduced compared to that of younger dryas time. the two lowermost samples of core fersina 2 (185 and 186 m) must date from either the older or the oldest dryas. it is not possible to decide which of these two stadial phases is the one truly represented. fig. 2 shows that the lowermost clay of the profile fersina 2 can be correlated with the uppermost part of a thick sequence of rather homogeneous fine grained lacustrine sediment in the 423 m long profile fersina 1. as no drastic changes in the composition of the sediments are apparent, it is likely that the lower part of the profile fersina 1 is also of late-glacial age. older sediment is not likely to have escaped erosion by the water running off under the large, melting adige glacier, especially in the middle of the valley where the coring site is located. pre-würmian sediment can be preserved only in rare sheltered positions. 7. conclusions in contrast to that supposed so far, the fersina 2 profile does not reach back in time to the last interglacial. instead, it was deposited totally during the youngest part of the late-glacial, i.e., during upper palaeolithic times. the sedimentation of fersina 2 (190 m of clay, sand and gravel) took only about 2500 to 3500 years, and it was finished before the holocene (= postglacial) development of species-rich forests began. this happened in the trento area around 11,500 cal a bp, in archaeological terms, during mesolithic times, several thousand years before the neolithic culture reached the trento area. the ancient neolithic units at the archaeological sites riparo gaban and ala le corone in trento date from 6749-6993 and 6551-6892 cal a bp, respectively (angelucci & bassetti, 2009). that the entire fersina 2 sediment sequence was deposited during the late-glacial is in agreement with the situation in the eastern alps, where the filling up of glacially over-deepened valleys was completed before the postglacial started (van husen, 1979). the results of the fersina 2 study necessitate reconsidering the dating of the 193 m long profile p3, taken about 5 km north of fersina 2 in the industrial zone of trento at an elevation of 190 m (venzo, 1957, 1979). venzo stated that “the stratigraphical and sedimentological data testify to the existence of an ancient lacustrine basin immediately following the last glaciation in the adige river valley (i dati stratigrafici e sedimentologici della serie testimoniano l’esistenza nella zona di trento di un antico bacino lacustre di grande estensione, immediatamente successivo al ritiro dell’ultima glaciazione)“. venzo called the basin also a “bacino lacustre post-würmiano”, “a post-glacial lacustrine basin”, definitely referring to the proper postglacial (=holocene). venzo totally disregarded the preceding more than 15,000-year-long late-glacial period, during which the adige valley of the trento area was ice free, a necessary condition of the deposition of the fersina 1 and 2 sediment. as venzo’s site p3 (venzo 1957) must have been located in the area of the same late-glacial lake as the fersina 2 site, the p3 profile must also be of late-glacial age. this is even in agreement with venzo’s note cited above on the formation of the lake basin. the same applies to the 30 m deep well via giuseppe verdi in the center of trento, 3 km north of the fersina 1 and 2 wells (fuganti et al., 1998). it may be surprising that in the core of this well, 11 m below the modern surface, a piece of wood with a radiocarbon age of only 4710 ± 80 cal a bp (table 2) was found in lateglacial sediment. this discrepancy can be explained if it is assumed that the meandering rivers adige and fersina cut channels into the late-glacial sediment which were later filled with material from the surroundings containing wood of (in this case) subboreal age. the number of pollen types found in the fersina 2 samples is low when compared with the younger dryas pollen samples of the other mentioned profiles. this difference results from the fact that their younger dryas samples contain the pollen rain of many years (e.g. about 14 and about 20 years, respectively, in the profiles saltarino sotto and bondone) whereas the fersina 2 samples contain, due to the huge annual sedimentation rate, less than one year’s pollen precipitation only. as pollen analytical dating is mostly based on common pollen types, the fersina 2 pollen data are sufficient to date the core, they but are not detailed enough to discuss problems of the north italian vegetation history. acknowledgements we thank andrea fuganti (trento) very much for 107 …. fersina 2, an entirely late-glacial sediment sequence ….. the permission to study the samples of the fersina 2 well, and for discussions about the morphology of the trento area and the influence of the river fersina on the sedimentation processes in the adige valley. we owe the wiggle matching to bernhard weninger and mebus a. geyh. ruth drescher-schneider, angelika kleinmann, werner kofler, josef merkt, and roberta pini helped by sending reprints, by contributing information, and by discussing special problems. the layout of fig. 2 is the work of christine preinfalk. gisela and wolfgang tambour touched up the original drafts of the figures and converted them into the necessary electronic files. dirk van husen patiently taught the first author the principles of sedimentation in alpine valleys. dean hansen improved the english. many thanks to all of them! references ammann b., van leeuwen j.f.n., van der knaap w.o., lischke h., heiri o, tinner w. (2012) vegetation responses to rapid warming and to minor climatic fluctuations during the late-glacial interstadial (gi -1) at gerzensee. palaeogeography, palaeoclimatology, palaeoecology. http://doi.10.1016/ j.palaeo.2012.07.010 angelucci d.e., bassetti m. (2009) humans and their landscape from the alpine last glacial maximum to the middle holocene in trentino: geoarcheological considerations. preistoria alpina, 44, 1-20. beug h.-j. (1964) untersuchungen zur spätund postglazialen vegetationsgeschichte im gardaseegebiet unter besonderer berücksichtigung der mediterranen arten. flora, 154, 401-444. björck s., walker m.j.c., cwynar l.c., johnsen s., knudsen k.-l., lowe j.j., wohlfarth b. (1998) an event stratigraphy for the last termination in the north atlantic region based on the greenland ice-core record: a proposal by the intimate group. journal of quaternary science, 13, 283– 292. calderoni g., finotti f., iliceto v., leonardi d., paganelli a. (1996) topography-based identification of a palaeopeat-bog at isera, near rovereto (trento, italy) and first stratigraphic, radiocarbon and palynological results. il quaternario – italian journal of quaternary sciences, 9, 671-678. diepenbroek m., grobe h., sieger r. (2001) panplot. http: //www.pangaea.de/software/panplot. drescher-schneider r. (2009) la storia forestale delle alpi sud-orientali e del margine pedemontano durante gli ultimi 25 mila anni / the forest history in the southeastern alps and the foothills during the last 25,000 years. in: peresani m., ravazzi c. (eds.): le foreste dei cacciatori paleolitici. supplemento al bollettino della società naturalisti silvia zenari, 27-51 and 52-64, pordenone, 2009. drescher-schneider r., de beaulieu j.-l., magny m., walter-simonnet a.-v., bossuet g., millet l., brugiapaglia e., drescher a. (2006) vegetation history, climate and human impact over the last 15,000 years at lago dell’accesa (tuscany, central italy). vegetation history and archaeobotany, 16, 279-299. eisele g., haas k. liner s. (1994) methode zur aufbereitung fossilen pollens aus minerogenen sedimenten. (supplement to: frenzel b. über probleme der holozänen vegetationsgeschichte osttibets). göttinger geographische abhandlungen, 95, 165-166. filippi m.l., heiri o., arpenti e., angeli n., bortolotti m., lotter a.f., van der borg k. (2007) evoluzione paleoambientale dal tardoglaciale a oggi ricostruita attraverso lo studio dei sedimenti del lago di lavarone (altopiano di folgaria e lavarone, trentino). studi trentini di scienze naturali, acta geologica, 82 (2005), 279-298. fuganti a., bazzoli g., morteani g. (1998) the quaternary evolution of the adige valley near the city of trento (northern italy) as deduced from wells and radiocarbon dating. preliminary results. studi trentini di scienze naturali, acta geologica, 73 (1996), 93-97. fuganti a., bazzoli g., morteani g. (2001) la genesi della valle dell’adige. studi trentini di scienze naturali, acta geologica, 77 (2000), 205-219. grüger j. (1968) untersuchungen zur spätglazialen und frühpostglazialen vegetationsentwicklung der südalpen im umkreis des gardasees. botanische jahrbücher, 88, 163-199. husen d. van (1979) verbreitung, ursachen und füllung glazial übertiefter talabschnitte an beispielen in den ostalpen. eiszeitalter und gegenwart, 29, 9 -22. kofler w. (1994) die vegetationsentwicklung im spätpaläolithikum und mesolithikum im raume trient (lo sviluppo della vegetazione nel tardo paleolitico e mesolitico nel trentino). preistoria alpina – museo tridentino di scienze naturali, 28 (1992), 83-103. pini r (2002) a high-resolution late-glacial – holocene pollen diagram from pian di gembro (central alps, northern italy). vegetation history and archaeobotany, 11, 251-262. ravazzi c. (2007) il tardoglaciale: suddivisione stratigrafica, evoluzione sedimentaria e vegetazionale nelle alpi in pianura padana. studi trentini di scienze naturali, acta geologica, 82 (2005), 1729. ravazzi c., donegana m., vescovi e., arpenti e., caccianiga m., kaltenrieder p., londeix l., marabini s., pini r., vai g.b, wick l. (2006) a new lateglacial site with picea abies in the northern appennine foothills: an exception to the model of glacial refugia of trees. vegetation history and archaeobotany, 15, 357-371. ravazzi c., peresani m., pini r., vescovi e. (2007) il tardoglaciale nelle alpi italiane e in pianura padana. evoluzione stratigrafica, storia della vegetazione e del popolamento antropico. il quaternario italian journal of quaternary sciences, 20, 163184. reimer p.j., baillie m.g.l., bard e., bayliss a., beck j.w., blackwell p.g., bronk ramsey c., buck c.e., burr g.s., edwards r.l., friedrich m., grootes p.m., guilderson t.p., hajdas i., heaton 108 grüger e., morteani g. t.j., hogg a.g., hughen k.a., kaiser k.f., kromer b., mccormac f.g., manning s.w., reimer r.w., richards a.a., southon j.r., talamo s.,turney c.s.m., van der plicht j., weyhenmeyer c.e. (2009) intcal09 and marine09 radiocarbon age calibration curves, 0– 50,000 years cal bp. radiocarbon, 51, 11111150. schwander j., eicher u., ammann b. (2000) oxygen isotopes of lake marl at gerzensee and leysin (switzerland), covering the younger dryas and two minor oscillations, and their correlation to the grip ice core. palaegeography, palaeoclimatology, palaeoecology, 159, 203-214. stebich m. (1999) palynologische untersuchungen zur vegetationsgeschichte des weichsel-spätglazial und frühholozän an jährlich geschichteten sedimenten des meerfelder maares (eifel). dissertationes botanicae, 320, 127 pp. stockmarr j. (1971) tablets with spores used in absolute pollen analysis. pollen et spores, 13, 615621. van raden u.j., colombaroli d., gillia a., schwander j., bernasconi s.m., van leeuwen j., leuenberger m., eicher u. (2012) high-resolution lateglacial chronology for the gerzensee lake record (switzerland): δ18o correlation between a gerzensee-stack and ngrip. palaeogeography, palaeoclimatology, palaeoecology. http:// dx.doi.org/10.1016/j.palaeo.2012.05.017 venzo g.a. (1957) ricerche sulla serie lacustre e fluviale attraversata de pozzi trivellati nella zona industriale di trento. giornale di geologia, 26, 173 -188. venzo g.a. (1979) glaziale übertiefung und postglaziale talverschüttung im etschtal im raum von trient (italien). eiszeitalter und gegenwart, 29, 115-121. vescovi e., kaltenrieder p., tinner w. (2010) lateglacial and holocene vegetation history of pavullo nel frignano (northern appennines, italy). review of palaeobotany and palynology, 160, 32-45. vescovi e., ravazzi c., arpenti e., finsinger w., pini r., valsecchi v., wick l., ammann b., tinner w. (2007) interactions between climate and vegetation during the lateglacial period as recorded by lake and mire sediment archives in northern italy and southern switzerland. quaternary science reviews, 26, 1650-1669. weninger b., jöris, o. (2008) a 14c age calibration curve for the last 60 ka: the greenland-hulu u/th timescale and its impact on understanding the middle to upper paleolithic transition in western eurasia. journal of human evolution, 55, 772-781. wick l. (2000) vegetational response to climatic changes recorded in swiss late-glacial lake sediments. palaeogeography, palaeoclimatology, palaeoecology, 159, 231-250. 109 …. fersina 2, an entirely late-glacial sediment sequence ….. ms. received: april 05, 2013 final text received: jun 25, 2013 amq_28(1) coloph 3.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 28 (1), 2015, iii vi aiqua congress in turin february 24th 26th, 2015 the plio-pleistocene continental record in italy: highlights on stratigraphy and neotectonics in honour of francesco carraro giuseppe orombelli university of milano-bicocca, milano, italy corresponding author: g. orombelli <giuseppe.orombelli@unimib.it> abstract: the 2015 aiqua congress (torino, february 24-26) highlighted the advances on the studies concerning the stratigraphy of plio-pleistocene continental records and the neotectonic deformation of key representative areas in both alpine and apennine contexts. two field trips that followed the conference focused on the type-area of the villafranchian succession” and on the ivrea morainic amphitheatre. keywords: quaternary, aiqua congress, torino, italy the annual aiqua (italian association for quaternary research) meeting took place in turin, february 24-26, 2015. it was organized in honour of prof. francesco carraro by the earth sciences department of the turin university, with the collaboration of colleagues from the cnr institute of geosciences and earth resources. the conference theme was "the pliocenepleistocene continental record in italy: highlights on stratigraphy and neotectonics". two topics that have marked much of the research of francesco carraro. francesco was the main promoter and one of the aiqua founders. he was aiqua president and adviser for many years. attendance at the meeting was intense and warm and showed the maturity and scientific progress achieved by the italian quaternary community. on february the 24th the historic "hall of coats of arms" (1893) of the national mountain museum "duca degli abruzzi" in monte dei cappuccini was crowded by researchers (about sixty) coming from all over italy almost as suggested by the arms of the italian cities painted on the hall walls. after the greetings of mr. roberto ferrero, on behalf of the italian alpine club and of the mountain museum, and of the department director prof. daniele castelli, the conference was opened by prof. gabriella forno, meeting organizer together with franco gianotti and giovanni monegato. during the entire day 14 communications, the visit to the posters and the presentation of two excursions to villafranca d'asti (g. forno) and to the ivrea moraine amphitheater (f. gianotti) occurred. the writer of these notes opened the communication section and, based on his blurry memories, tried to summarize the development of quaternary studies in the last half century (how much quaternary grew up! 50 years of impressive breakthrough and extraordinary adventures). thanks to the progress of research and dating methods and to the urgency of environmental problems, from specialized niche area the quaternary geology (a short term for the whole spectrum of stratigraphic, geomorphological, palaeobiological, palaeoenvironmental, palaeoclimatic and neotectonic studies dedicated to the quaternary) has fully established itself and has attracted a growing number of full-time researchers. so that, for example, from a single scientific journal in the 50s and 60s of the last century it has been reached more than 20 journals having the term quaternary (or equivalent) in the title, and even more numerous are the scientific journals that routinely publish articles of quaternary interest. then the aiqua president adele bertini took the floor (the history of late pliocene-middle pleistocene terrestrial settings in italy: vegetation and palaeoenvironmental changes as a response to the northern hemisphere insolation forcing and regional tectonics) summarizing a rich, varied and detailed contribution of palynology to the reconstruction of vegetation and environmental changes that occurred in italy from the piacenzian to the middle pleistocene, in response to cyclicalclimate change on a global scale, or to tectonic evolution at local-regional scale. r. sardella, also on behalf of russo ermolli, (pleistocene large mammals and pollen from the mercure basin southern italy) described mid-pleistocene fauna and pollen and tephrostratigraphic record contained in the fluvio-lacustrine deposits of the mercure basin (southern apennines). the presentation of mazzini (mazzini i., e. regattieri, b. giaccio, g. zanchetta, s. nomad, rn drysdale, p. galli, e. peronace the sulmona basin lake during the early last glacial: palaeoclimate vs palaeohydrology) related to the study of a carbonate lacustrine section of the sulmona basin, containing four levels of tephra dated 92 to 110 ka bp. the analysis of stable isotopes and ostracod associations helped to identify and correlate climatic events that have marked the early stages of the last main glacial cycle. m. spadi (m. spadi, m. nocentini, e. gliozzi, d. cosentino the early evolutive stages of the l’aquila basin (central italy) inferred from paleontological and stratigraphical analyses) showed the plio-pleistocene stratigraphic succession representative of the early stages of infill of the intermontane basin of l’aquila, when it was still divided into two sub-basins separated by a bedrock threshold. the environmental development, also documented with the ostracod assemblages, experienced a main phase of tectonic uplift highlighted by a stratigraphic unconformity occurring in both the two sub-basins. thanks to his expertise and knowledge that started right in aiqua at the instigation of f. carraro and c. bosi, fabrizio galadini illustrated the current state in italy of the study of active and capable faults, and of related scientific problems and regulations (the quaternary geology applied to the study of active and capable faults: the state of knowledge in italy). s. gori addressed the topic of changes of the hydrographic network (stream piracy, drainage reversal) in central apennines, caused by erosional phases related to the tectonic evolution of the chain during the earlymiddle pleistocene transition (s. gori, e. falcucci , g. scardia, s. nomad, h. guillou, f. galadini, p. fredi early capture of a central apennine (italy) internal basin as a consequence of enhanced regional uplift at the early-middle pleistocene transition). in the tiber basin (valle umbra) palaeocarpological remains and pollen data collected from the section of the beveragna-arquata quarry provided information on the late pleistocene palaeoclimate and palaeoenvironment, described by r. bizzarri (a. baldanza, r. bizzarri, r. colacicchi, p. corrado, d. magri, e. martinetto early capture of a central apennine (italy) internal basin as a consequence of enhanced regional uplift at the earlymiddle pleistocene transition). with the note presented by a. irace (a. irace, g. monegato, e. tema, e. martinetto, d. gianolla, e. vassio, l. bellino, d. violanti the first late piacenziangelasian fluvial record in northern italy: insights from the alessandria basin) we moved to northern italy: in the alessandria basin the coarse river sedimentation started at the end of piacenzian after a climate deterioration dated to 2.8 myr, also documented by carpoflora. in the late piacenzian-gelasian the basin was deformed by a ns shortening related to the north-apennine thrust front. on the basis of peculiarities of the lower cerrina valley (monferrato) and their stratigraphic and structural data, carlo giraudi (could the low cerrina valley – piedmont, nw italy be an early and middle pleistocene trough developed behind the monferrato thrust fig. 1 the audience at the aiqua meeting of turin in the "hall of coats of arms" of the national mountain museum. in the second row, fourth from right, francesco carraro iv orombelli g. front?) put forward the hypothesis that this sector, raised after the messinian, remained emerged during the pliocene, to become subsiding during early and middle pleistocene, because of the northward migration of the monferrato thrust beneath the vercelli plain. a. fontana (late quaternary alluvial megafans in northern italy), on behalf of the co-author p. mozzi too, described the megafan alluvial system, placed at the foot of the alps during the last glacial maximum (27-19 ka bp) and incised during the lateglacial-early holocene. in the veneto-friuli area distal parts of megafans are directly connected to the adriatic and have been affected by the holocene sea levelrise. p. mozzi spoke instead about the interpretation problems related to the montebelluna megafan at the mis 3-2 transition (p. mozzi, s. rossato, v. pascucci, s. andreucci, g. monegato, a. fontana, d. sechi aggradation of the montebelluna megafan (ne italy) at the mis 3-2 transition, problems and perspectives.) m. e. poli and g. monegato showed extensive evidence of neotectonic deformations along the southern alps thrust-front in western friuli (neotectonic evidence of the plio-pleistocene activity of the eastern southalpine thrust front in western friuli). in particular they showed morphotectonic evidence of faults that displace alluvial fans referred to the lgm with metric height differences, involving sliding rates up to 0.6 mm / year. e. falcucci (e. falcucci, m.e. poli, f. galadini, g. paiero, g. scardia, a. zanferrari first paleoseismological evidence of active deformation along the eastern front of the southern alps ne italy, friuli) described evidence of recent deformations induced by faults related to seismic events that occurred in the vi-vii and in the xv-xvi centuries ad. before the lunch offered by the organization, marco giardino brilliantly and nicely sketched with spirit the figure and work of francesco carraro, quaternary geologist and disseminator of knowledge on surface environments, adding to his say with numerous photos of the celebrated professor. francesco carraro replied with a brief greeting, sincere and heartfelt, welcomed by the audience with a prolonged applause. at the end of the day, g. forno shortly illustrated the field excursion to the area of villafranca d’asti, where two deltaic and fluvial sedimentary sequences separated by an angular unconformity are attributed respectively to piacenzian and calabrian. a regional transcurrent n-s structure at the western margin of the area was also described. the displayed posters: d. barbero, a. doglione, m.g. forno, m. gattiglio the importance of stratigraphic and structural aspects in the mitigations of landslides involving slopes near aguggia (san damiano d’asti). f. finocchiaro, s. furlani, d. lenaz, g. boschian, e. zordan sedimentological and mineralogical reconstruction of a quaternary sequence in val rosandra (trieste, ne italy). g. fubelli, g. amato, m. della seta evidence of fault inactivity: a multidisciplinary approch integrating geomorphology, stratigraphy and paleontology. e. martinetto, a. irace, g. monegato, e. vassio an updated overview of the distribution of biochronologically relevant fruit and seed taxa in the pliopleistocene of italy. m.r. palombo dispersal bioevents of large mammals in sw europe during the early pleistocene: implications for biochronology and faunal dynamics. p. sassone, r. gamba, l. navone strutture recenti nord-vergenti a basso angolo in val cerrina (monferrato casalese): nuove segnalazioni. abstracts of communications and posters are published on n. 26 (2015) of miscellaneous ingv (http:// istituto.ingv.it/l-ingv/produzione-scientifica/miscellaneaingv/) allow me here a personal thought and a tribute to francesco carraro. strong and determined in his choices, francesco came across the problems of quaternary geology in the late 60s of last century, coming from that group of young geologists who worked in universities, attending to the survey of the geological map of italy, thanks to the law 15.01.1960 ("completion and updating of the geological map of italy"), , which brought within fifteen years to survey and publication of 276 new sheets at 1:100,000 scale and the related notes. in particular carraro took a part in the survey of the sheets biella (43), peschiera del garda (48), verona (49), carmagnola (68), dronero (78-79), demonte (90), in many of which large areas are occupied by quaternary continental glacigenic or fluvial deposits. heir of the teachings of sergio venzo and roberto malaroda with his colleague and inseparable friend franco petrucci, in the following years he devoted himself to the survey of the ivrea and tagliamento morainic amphitheaters. studies of the last one, that were carried out after the friuli 1976 earthquake, brought him to further reflection on modality of the construction of the moraine systems left behind by pleistocene piedmont glaciers at the foothills of the alps. all his subsequent work was dedicated with admirable perseverance and conviction to the study of "geology of surficial formations " (his definition) with all its aspects, from stratigraphy to the geological survey, from neotectonics, to relationship with geomorphology and applied geology. francesco had a decisive role, gener v the plio-pleistocene continental record in italy ... fig. 2 the aiqua president , adele bertini, during the turin meeting ous and disinterested in promoting quaternay studies in italy, he was tireless in raising initiatives, debates, even provocation, in order to attract attention and stimulate young researchers to this field of study. his book "quaternary geology", which aimed to collect and systematize knowledge and reflections coming from its long and direct experience of study, survey and analysis was recently published. the book, which is rich in illustrations, diagrams, drawings and photographs, is a compendium of knowledge, problems, experiences that in recent decades have characterized the study of the continental quaternary in italy. it stands for new generations of researchers as an achievement on which further advances should be grounded. vi orombelli g. ms. received: may 5, 2015 final text received: may 13, 2015 microsoft word 00_indice_lm04.docx il quaternario it issn 039-3356 italian journal of quaternary sciences 24 (1), 2011 131-140 first data on the latest pleistocene mammals from mora cavorso cave (jenne, latium, central italy) leonardo salari1, daria passacantando2 & mario f. rolfo3 1 department of earth sciences, university of rome sapienza, rome 2 department of biological sciences, university of rome tor vergata, rome 3 department of cultural heritage, university of rome tor vergata, rome correspondent author: l. salari <leonardosalari@virgilio.it> abstract: salari l., passacantando d. & rolfo m.f., first data on the latest pleistocene mammals from mora cavorso cave (jenne, latium, central italy). since 2006 the mora cavorso cave has been object of archaeological investigations, and archaeological and faunal finds have been recorded referable, with some discontinuities, to an interval of time lasting over 13,000 years. the most ancient testimonies till now investigated are referable to the terminal phases of the late pleistocene and are followed by various holocene layers between the mesolithic and the middle age. in this paper the preliminary data related to the large mammals, together with the hare and the greats rodents, attributed to the latest pleistocene are described. nine taxa of fossil mammals in the “dig b2” of the room 1 and ascribed to a late upper paleolithic cultural horizon (final epigravettian) have been found: lepus sp., marmota marmota, vulpes vulpes, mustela nivalis, sus scrofa, cervus elaphus, capreolus capreolus, rupicapra sp. and capra ibex. from other places of the cave (the perturbed ground of the room 1 and the “sinkhole”) the fossil remains of lepus sp., lepus corsicanus, castor fiber, m. marmota, canis lupus, ursus arctos, equus ferus, e. hydruntinus, s. scrofa, c. elaphus, c. capreolus and c. ibex have been also found and these too are referable to the latest pleistocene. the marmot and the ibex are the most significant species, but is even important the red deer presence, and a particular attention deserves also european beaver, till now not signaled in lateglacial mammal assemblages of central italy, and the sure evidence of the italic hare. the ecological requirements of the present taxa allow reconstructing the environment of the simbruini mounts and the tall of the aniene river valley during such period colder than today, outlining a composite landscape with forests and woods alternated with grasslands, rocky bands and scree slopes, and wetlands. riassunto: salari l., passacantando d. & rolfo m.f., primi dati sui mammiferi tardopleistocenici della grotta mora cavorso (jenne, lazio, italia centrale). la grotta mora cavorso è oggetto d’indagini archeologiche dal 2006 ed ha restituito reperti archeologici e faunistici che coprono, con qualche discontinuità, un intervallo di tempo di oltre 13.000 anni. le più antiche testimonianze finora indagate sono riferibili alle fasi terminali del pleistocene superiore e sono seguite da vari livelli olocenici compresi tra il mesolitico e il medio evo. nella presente nota sono esposti i dati preliminari relativi ai grandi mammiferi, cui sono stati aggregati la lepre e i grossi roditori, rinvenuti nel “saggio b2” della sala 1 e attribuiti al tardo pleistocene superiore; altri resti di vertebrati tardopleistocenici sono stati recuperati in diversi luoghi della grotta (terreno rimaneggiato della sala1 e “inghiottitoio”). le specie maggiormente significative sono marmotta e stambecco, ma è altresì importante la presenza del cervo e meritano una menzione particolare anche il castoro, finora non segnalato tra le faune tardoglaciali dell’italia centrale, e l’individuazione certa della lepre italica. le esigenze ecologiche dei taxa presenti permettono di ricostruire l’ambiente dei monti simbruini e dell’alta valle dell’aniene durante tale periodo più freddo rispetto ad oggi, delineando un paesaggio composito, con foreste e boschi intervallati da praterie, fasce rocciose e aree a pietraia e zone umide. key words: vertebrates, mammals, late pleistocene, epigravettian, palaeoecology. parole-chiave: vertebrati, mammiferi, pleistocene superiore, epigravettiano, paleoecologia. 1. introduction the cave locally called mora cavorso opens to 720 m a.s.l. in the locality palo montano near jenne (rome, latium, central italy); it leans out on the right slope of the upper aniene river valley inside the simbruini mounts regional natural park (fig. 1a). this karst cavity is carved in the “calcilutiti e calcareniti del conaciano-campaniano” formation (c911/38, upper cretaceous) (damiani et al., 1998). the cave has a succession of rooms and ducts. the room 1 (medium dimensions, about 20 x 10 m) is closed towards outside by a recent stone wall and open directly on the slope, on the bottom it is open a passage that leads to a natural duct with slight slope, partially filled by a recent holocene deposit. at the end of the duct the room 2 opens, the first in the interior (about 6 x 4 m), it is paved by a stalagmite crust and below an archaeological deposit is present. on the north wall a second natural duct starts, horizontal, strongly concretioned, about 20 m length, at the end two paths (upper room and lower room) with anthropological remains open (rolfo et al., 2009; 2010). following the discovery of human bones inside the cave, by the members of “shaka zulu” speleological club of subiaco, the archaeological investigations in the l. salari, d. passacantando & rolfo m.f. 132 cave in 2006 started. the digs initially focused the areas of the neolithic human remains outcrop and subsequently in more stratigraphical digs in the most external rooms to the purpose of investigating the stratigraphical sequence of the deposit (fig. 1b). in particular, in the dig b2 (a trench about 4 x 3 m behind the stone wall, in the eastern sector of the front of room 1), just below a perturbed surface layer, the stratigraphic units 109, 110, 120, 135, 254 and 255 (= “dig b2”) are characterized by a compact reddish-brown silty ground with limestone clasts with sharp edges, where a moderate quantity of lithic artifacts referable to a late upper paleolithic cultural horizon (final epigravettian) and numerous fossil remains of vertebrate animals have been recovered. the calcareous floor of the cave has not yet been reached. in this paper the first data on the large mammals, together with the hare and the greats rodents, recorded in “dig b2” and attributed to the latest pleistocene are presented. other mammal remains referable to the latest pleistocene and that have been also found from the filling of an sinkhole that partially opens on the right side of the entry of the cave (= “sinkhole”) and from the perturbed ground of the room 1 are also described. 2. stratigraphic notes the synthetic stratigraphy of the various areas of the cave shows a variously articulated deposit (fig. 2) that develops from the deepest layer till now investigated, referred to the latest pleistocene, up to the superficial level of historical age (rolfo et al., 2010). the “dig b2” is the most ancient layer investigated with stratigraphical methodology and it has been intercepted in the room 1, below the altered surface layer with micromammal and bird remains and several fossil bones of great wild mammals together with numerous finds of prehistoric and recent domestic mammals. the “dig b2” is a compact reddish-brown silty ground with limestone clasts with sharp edges that vary in diameter from few millimeters to the centimeter, and with a thickness of about 20-30 cm. in this layer many fossil remains of vertebrate have been found together with a moderate number of lithic artifacts referable to final epigravettian, such as a frontal scraper on a retouched blade of jaspered flint, three fragments of backed blade lets, a fragment of backed point and a multiple burin. a radiometric dating1 performed on a marmot mandible from this layer, has provided the age of 13,460±50 years bp (calibrated 14,175 13,910 bc 1σ) and agrees well with the attribution of the “dig b2” lithic artifacts to a final epigravettian cultural horizon. the “sinkole” instead is the filling of a sinkhole that partially opens on the right side of the entry of the cave. this include a pinkish-gray silty sand ground with coarse limestone breccias with sharp edges, and a small level with reddish slimy soil, and there some bone remains of vertebrate referable to the latest pleistocene have been also found. 1 all the radiometric dating have been performed by the “centre de datation par le radiocarbone cnrs”, lyon (france), except that on a mesolithic red deer tooth, performed by the “beta analytic inc.”, miami (u.s.a.). fig. 1 mora cavorso cave: a) location of the site; b) longitudinal section (up) and plan (down) of the cave. grotta mora cavorso: a) ubicazione del sito; b) sezione (in alto) e pianta (in basso) della grotta first data on the latest pleistocene mammals from mora cavorso cave… 133 a layer from the inferior room which can be attributed to early holocene (mesolithic cultural phase) follows; it is rich of cervus elaphus bones in partially articulated (salari et al., 2009; rolfo et al., 2010). also for this level have been made two radiometric dating, one on a red deer tooth (8,770 ± 60 years bp, calibrated 7,950 7,790 bc 1σ), and the other on a charcoal fragment (8,805 ± 45 years bp, calibrated 8,197 7,729 bc 1σ). in this layer, except a moderate number of charcoal fragments and various ashes spots, no other evidence of human presence has been discovered. this level underlies a layer dated to the ancient neolithic characterized by the noticeable presence of abundant human remains referable at least 21 individuals (passacantando, 2009), concerning partly disturbed burials (in the upper and lower room). archaeological finds have also been recovered and are pertinent to the various funeral outfits (rolfo et al., 2009; 2010), together with bones and teeth primarily of domestic fauna, above all ovis vel capra (salari et al., 2009). as well in this case two radiometric dating are been performed, the first one on human bone (6,405 ± 35 years bp, calibrated 5,472 5,314 bc 1σ), the second on a charcoal fragment (6,275 ± 45 years bp, calibrated 5,322 5,084 bc 1σ). a layer from the room 2 (dig c) has to be referred to the neolithic final phase; it is characterized by a level rich of charcoal and ashes. in the deeper part of the room 1 (dig b1) the archaeological sequence is superficially covered by a layer very rich of pottery (fragments and a whole bowl) shed anywhere, and human bones, referable to disturbed burials dated to the middle bronze age (first half of ii millennium bc). rare but noticeable it is the pottery referable to the historical age (viii-x century ad) recovered in the dig a, in the external dig, and on the ground of the upper level of the dig b1 of the room 1 (rolfo et al., 2010). 3. methodology the proceeding of the analyses of the “dig b2” faunal remains, referable to a final epigravettian horizon, were carried on at the same time to archaeological investigations progress. other mammal remains referable to the latest pleistocene have been recovered from the “sinkhole” and from a disturbed level of the room 1. the examined finds have been compared to the osteological material stored in the department of earth sciences of the university of rome “sapienza”. the bone remains are very fragmentary and generally their state of preservation does not allow the individualization of the anatomical portion, neither the taxonomic determination. among the determined remains, nevertheless, there are also some intact skeletal elements like metapodials, carpal and tarsal bones, phalanges, isolated teeth and some mandibles. this material has been recovered in different places of the cave, so its description will be carried on taking into account the origin place of the remains. the mammal bones recovered in the “dig b2” originate from a level investigated with stratigraphical methodology, it is well dated both radiometrically and according to the cultural chronology and it is therefore possible to effect a numerical analysis. every taxon is quantified both in number of remains (nr) and in the minimum number of individuals (mni), calculated according bökönyi (1970); the fragments of ribs and vertebrae of difficult taxonomical attribution have been counted apart. for the material remainder, instead are listed out the recognized taxa and valued their relative frequency (tab. 1). 4. faunal description 4.1. the mammals remains from the “dig b2” from the “dig b2” over 1000 mammal remains have been recorded, 171 of which (17.05%) have been anatomically and taxonomically determined. from the fig. 2 mora cavorso cave: stratigraphic synthesis. grotta mora cavorso: stratigrafia sintetica. l. salari, d. passacantando & m.f. rolfo 134 tab. 1, in which the percentages of each taxon are calculated on the total of the determined fragments, while the percentages related to the ribs, to the vertebrae, to the undetermined and to the total determined remains are calculated on the general total, the most abundant taxon is marmota marmota (linnaeus, 1758), with more than the half of the determined remains and a third of the individuals. cervus elaphus linnaeus, 1758, capra ibex linnaeus, 1758, rupicapra sp. and lepus sp. are present with a certain number of fragments, sus scrofa. linnaeus, 1758, capreolus capreolus (linnaeus, 1758) and vulpes vulpes (linnaeus, 1758) with few finds, and mustela nivalis linnaeus, 1766 has present only a single fragment of mandible (fig. 3, n). these finds are accompanied by several birds bones, few amphibious bones and abundant micromammal remains above all rodents, particularly arvicola amphibius (linnaeus, 1758), apodemus sp. and small arvicolids, and scarce bats, rhinolophus ferrumequinum (schreber, 1774) and myotis bechsteinii (kuhl, 1817). the marmot is represented by bones of the whole skeleton (fig. 3, b-d), primarily mandible mainly fragmentary, isolated teeth, phalanges, metapodials and tarsal bones intact, while the skull and the other postcranial skeleton elements are fragmented. this fossil material is referable to at least 7 individuals; some deciduous teeth, a tibia with epiphysis not fused and a very small astragalus point out that among these at least one is a cub. the hare is present with some isolated teeth, metapodials and phalanges than at least two individuals; the scarcity of diagnostic morphological characters (see palacios, 1996) does not allowed a sure attribution of such finds to lepus europaeus pallas, 1778 or lepus corsicanus de winton, 1808. the fox is present with some metapodials and calcaneum (fig. 3, l) of an adult. the wild boar is present with an inferior molar, a third metacarpus (fig. 4, d), a metapodial with distal epiphysis not fused, a carpal bone and a first lateral phalanx concerning a fully grown and a young individual. the red deer is represented by isolated teeth, humerus, femur, tibia (fig. 4, i), carpal and tarsal bones, phalanges (some with the proximal epiphysis not fused) and sesamoids belonging a fully grown and a young individual. the roe deer is present with a mandibular branch fragment, some isolated teeth, two of which deciduous, and a phalanx referable to a young individual and an adult. the ibex is represented by isolated teeth, some of which deciduous, radius, coxal, femur, metapodials with distal epiphysis not fused (fig. 4, f-g), tarsal bones and phalanges referable to a young individual and an adult. the chamois is present with isolated teeth, some of which deciduous, radius (fig. 4, m), ulna and phalanges concerning a fully grown and a young individual; the fragmentary of the finds and particularly the absence of cranial parts with horn cores, useful to the distinction between rupicapra rupicapra (linnaeus, 1758) and rupicapra pyrenaica bonaparte, 1845 (see masini & lovari, 1988), allow to identifying the chamois only to the genus level. the presence of the lithic artifacts and the same mammal assemblage, characterized essentially by ungulate and marmot, would suggest an anthropic contribution of the bone accumulation, but till now only an undetermined fragment with a lithic tool incision has been observed. some bones show traces of gnawing of rodents, while neither signs of carnivores or further traces of human activity are present. considering also the large number of small animals and young individuals among the ungulate ones, it cannot be excluded that, over the humans, also the raptor birds and/or the other factors have contributed to the accumulation of the “dig b2” bones. taxon “dig b2” “sin kh ole” per tur bed n r m n i freq. freq. n. % n. % lepus sp. hare 11 6.43 2 9.52 r r lepus corsicanus italic hare rr castor fiber european beaver rr marmota marmota marmot 94 54.97 7 33.33 a ca canis lupus wolf c vulpes vulpes fox 4 2.34 1 4.76 ursus arctos brown bear cr mustela nivalis weasel 1 0.58 1 4.76 equus ferus rr equus hydruntinus c sus scrofa wild boar 5 2.92 2 9.52 rr cervus elaphus red deer 25 14.62 2 9.52 r ca capreolus capreolus roe deer 4 2.34 2 9.52 r capra ibex ibex 16 9.36 2 9.52 c c rupicapra sp. chamois 11 6.43 2 9.52 total determined 171 17.05 21 ribs 136 13.56 vertebrae 36 3.59 undetermined 660 65.80 total 1003 tab. 1 mora cavorso cave, late pleistocene: number of remains (nr), minimum number of individuals (mni) and percentages (%) from the “dig b2”, and mammal remains frequency (freq.) from the other archaeological contexts (“sinkhole” and the perturbed ground of the room 1); rr: very rare; r: rare; cr: common-rare; c: common; ca: common-abundant; a: abundant. grotta mora cavorso, pleistocene superiore: numero dei resti faunistici (nr), numero minimo degli individui (mni) e relative percentuali (%) del “saggio b2”, e frequenze dei resti faunistici (freq.) relative agli altri contesti archeologici (“inghiottitoio” e terreno rimaneggiato della sala 1); rr: rarissimo; r: raro; cr: comune-raro; c: comune; ca: comune-abbondante; a: abbondante first data on the latest pleistocene mammals from mora cavorso cave… 135 fig. 3 mora cavorso cave, late pleistocene: lepus corsicanus, a) skull; marmota marmota, b) maxilla, c) calcaneum; d1) mandible, lingual view, d2) mandible, labial view; castor fiber, e) mandible, f) skull fragment; ursus arctos, g) upper canine, h) lower canine, i) second lower molar; vulpes vulpes, l) calcaneum; canis lupus, m) mandible; (scale bar: 5 cm); mustela nivalis, n) mandible (scale bar: 2 cm). grotta mora cavorso, pleistocene superiore: lepus corsicanus, a) cranio; marmota marmota, b) mascellare, c) calcagno; d1) mandibola, norma linguale, d2) mandibola, norma labiale; castor fiber, e) mandibola, f) frammento di cranio; ursus arctos, g) canino superiore, h) canino inferiore, i) secondo molare inferiore; vulpes vulpes, l) calcagno; canis lupus, m) mandibola; (riferimento metrico: 5 cm); mustela nivalis, n) mandibola (riferimento metrico: 2 cm). l. salari, d. passacantando & m.f. rolfo 136   fig. 4 mora cavorso cave, late pleistocene: equus ferus, a) first phalanx; equus hydruntinus, b) first phalanx, c) astragalus; sus scrofa, d) third metacarpus; capra ibex, e) metacarpus, f) metacarpus (juvenis); g) metatarsus (juvenis); cervus elaphus, h) metatarsus, i) tibia; capreolus capreolus, l) metatarsus; rupicapra sp., m) radius; (scale bar: 5 cm). grotta mora cavorso, pleistocene superiore: equus ferus, a) prima falange; equus hydruntinus, b) prima falange, c) astragalo; sus scrofa, d) terzo metacarpo; capra ibex, e) metacarpo, f) metacarpo giovanile; g) metatarso giovanile; cervus elaphus, h) metatarso, i) tibia; capreolus capreolus, l) metatarso; rupicapra sp., m) radio; (riferimento metrico: 5 cm). first data on the latest pleistocene mammals from mora cavorso cave… 137 4.2. the mammals remains from the other archaeological contexts from a partially perturbed layer of the room 1 a thousand of vertebrate remains has been recovered in an advanced state of fossilization together with prehistoric and recent domestic mammals. small and mediumsized birds are present, micromammals (a. amphibius, apodemus sp. and small arvicolids), and bones and teeth attributed to hare, marmot, wolf (fig. 3, m), red deer (fig. 4, h), roe deer (fig. 4, l) and ibex (fig. 4, e) (rolfo et al., 2009; salari et al., 2009). some morphological features of a sub-intact skull of hare (fig. 3, a), particularly the occlusal surface contour of p2 with the postcone protrudes further than the lagicone (see palacios, 1996), allow attributing this find to l. corsicanus. in the “sinkhole” a hundred of vertebrate fossil remains chaotically assembled has been recovered, partly from a level characterized by a reddish slimy soil. the bones accumulation seems of reasonable natural contribution (water energy), nevertheless the emptying has not been completed yet, but till now lithic artifacts has not been recovered yet. the mandibles and the skull fragments of m. marmota are abundant and are accompanied by carpal and tarsal bones and phalanges of equus hydruntinus regalia, 1907 (fig. 4, b-c), isolated teeth, metatarsus and phalanges of c. ibex and isolated teeth of ursus arctos linnaeus, 1758 (fig. 3, g-i). there are also rare fragments of birds bones, micromammals and lepus sp., a few isolated teeth of c. elaphus, a skull portion and a mandible2 of castor fiber linnaeus, 1758 (fig. 3, e-f), and a first phalanx of equus ferus boddaert, 1785 (fig. 4, a) and a skull fragment of s. scrofa. 5. chronological and palaeoecological considerations the radiometric dating of 13,460±50 years bp (calibrated 14,175 13,910 bc 1σ) agrees well with the attribution of the “dig b2” lithic industry to a final epigravettian cultural horizon, and permit to attribute this mammal assemblage to the last glacial episode final phases, or rather to the first part of the lateglacial preceding the bølling allerød temperate oscillation (see ravazzi et al., 2007). the lateglacial climatic oscillations recorded in central-western europe also occur in italy, although with less intensity, especially in the mediterranean regions. in the piedmont alpine area, associations with ibex, chamois and marmot during the colder moments are frequent, together with elk, bison and alpine hare, that alternate to red deer and roe deer associations, sometimes accompanied to the wild boar during the temperate moments (petronio et al., 2007; sala, 2007). in mediterranean environment the lateglacial mammal assemblages seem to be conditioned by the geographical location and by the territory morphology at least how the climatic oscillations did. in fact the adriatic slope of the peninsula shows a harder climate than the tyrrhenian one, more temperate and humid. in the adriatic slope prevail associations with e. ferus, e. hydruntinus, chamois and ibex, typical of prevailing opened environments like steppe, prairie and arid mountain; in the tyrrhenian slope, instead, associations with red deer, wild boar and roe deer are present, together with ibex and sometimes to equids, and mark a wider presence of woodland and forest environments (petronio et al., 2007; sala, 2007). the ecological requirements of the taxa from the cave mammal assemblage may therefore provide some useful indications to reconstruct the environmental landscape of the simbruini mounts and of the upper aniene river valley in the late pleistocene final phases and to individualize, if possible, the chronology of the mammal remains recovered from the archaeological contexts others than the “dig b2”. the italic hare is a species adapted to live in different environments, but seems to prefer shrubby dry areas and prairie alternated with hardwood forest with large grassy open clearings; the european hare instead seems to be more connected to the open environments like prairie and steppe, and it is adapted to the traditional agricultural environments, characterized by mixed farming; today the marmot is present in the alps, pyrenees, carpathian and tatra mountains and, recently, has been reintroduced in some areas of the northern apennine and it lives in mountain places characterized by large alpine prairie with stony zone or scattered rock near high stem woods (amori et al., 2008). the european beaver is no longer present in italy since xvi-xvii century (petronio et al., 2007) and today it is present in damp and woodland environments, with streams and stretches of water between france and russia, and the northern balkans and the scandinavian peninsula (halley & rosell, 2002). among the carnivores, both the wolf and the fox are animals adapted to a variety of environments, but generally settle the lair in woodlands with gorges and stony zone; the brown bear is a forest species especially and it prefers environments rich of water; the weasel too prefers open woodland near water (boitani et al., 2003). among artiodactyls the wild boar prefers woods and wetlands, the red deer is particularly common in open woods with large grassy clearings, and the roe deer is a typically woody species and prefer hardwood forests rich of brushwood and clearings; the ibex actually lives on the alps frequenting rocky ledges and alpine prairie, and the chamois frequent coniferous and hardwood woody areas riches of brushwood spaced by rocky walls and stony zones, prairies, bare patches and grassy ledges (boitani et al., 2003). finally e. ferus and e. hydruntinus, were quite commons in the late pleistocene, preferring open environments like steppes and prairies, and their last occurrences in italy are in the early holocene (petronio et al., 2007; conti et al., 2010). the ecological requirements of the taxa discovered in the “dig b2” suggest the presence of woods and forests spaced by prairies, rocky bands and stony zones and wetlands near the site. evidently the faunal finds are been accumulated during a climatic period colder than today, like the presence of species as m. marmota 2 for mere material error, this mandible has been referred to the marmot in the fig. 2 caption of the abstract volume of “convegno in memoria di alberto malatesta (1915-2007) geologo e paleontologo. roma 4-5 febbraio 2010”. we apologize for the mistake. l. salari, d. passacantando & m.f. rolfo 138 and c. ibex shows. both the species were in the lateglacial faunal complex of the central-southern italy, in locality near the sea too, but now they are living in high mountain areas of the alpine arch. however the two species are not considered “cold” stenotherm, but euritherm species (capasso barbato et al., 1991), and nor even the ibex is considered a typical high mountain animal (masseti et al., 1995; phoca cosmetatou 2004). the last palaeontological evidence of m. marmota and c. ibex in centralsouthern italy, however, are referred to the early holocene (petronio et al., 2007), with the rapid climatic warming that characterized the early stages of this epoch, the consequent going up of the tree limit at higher altitude and a considerable reduction of the congenial alpine grasslands type. the distribution of these two species in the peninsula during the last millennia of the late pleistocene was been somewhat unequal. in the adriatic slope the marmot reached salento (southern apulia) (tagliacozzo, 2003), while in the tyrrhenian slope there would not be evidence of its presence at south of the latium. the ibex, frequently with the chamois, instead, is present in the tyrrhenian slope also in southern campania and northern calabria, while there would not be evidence of its presence at south of the gargano promontory (northern apulia) in the adriatic slope (phoca cosmetatou 2004; sala, 2007). the others “dig b2” taxa are currently in central italy and, except the chamois, also in the simbruini mounts area (amori et al., 2009). the faunal remains with an advanced fossilization status recovered in the room 1 together with the prehistoric and recent domestic fauna likely came from the dismantling of “dig b2”, probably because of clandestine excavate or of the arrangement of the cavern as a refuge during the second world war. the faunal assemblage is almost the same to that of the “dig b2” (tab. 1) and may be referred to the same final epigravettian horizon. the mammal remains recovered in the “sinkhole” have some affinities, but also differences compared to the “dig b2” fauna (tab. 1). some taxa (hare, marmot, wild boar, red deer and ibex) are the same and the relatively abundance of m. marmota is also a common element. remains of beaver, brown bear, e. ferus and e. hydruntinus are only in the “sinkhole”. although these are few fossil remains, the presence of the equids, in particular, together to the rare remains of red deer and wild boar, suggest a more opened environment with a less woody covering and perhaps referable to a moment probably cooler than that shown by the “dig b2” mammal fauna. the environments frequented by the total recovered taxa show a composite landscape, in some points not so different to the present, but during moments of climate colder than today. the simbruini mounts slopes were probably covered by deep forests and sparse woods (cervids, carnivores, chamois), spaced by rocky bands and stony ground (ibex, chamois, marmot), while the upper bottom valley were covered by prairies that may evolved in steppe (marmot, hare, equids, ibex) and the river offered banks rich of vegetations, sometimes marshy (wild boars, beaver). 6. comparison with other sites and conclusions in central italy different sites with lateglacial mammal faunas are known, generally associated to epigravettian lithic industry. leaving out the northern tuscany, these sites are placed along the tyrrhenian coast of tuscany and latium (cassoli, 1977; alessio et al., 1993; boscato, 1996; alhaique & di camillo, 2007), along the abruzzi and marche apennine (radmilli, 1977; wilkens, 1991; alhaique & recchi, 2001; 2003; alhaique, 2003; 2005; esu et al., 2006), and the latium inland (radmilli, 1974; pennacchioni & tozzi, 1985; cerilli & brocato, 1998; ucelli gnesutta et al., 2006). among these, some affinities can be noticed with several mammal faunas of the fucino basin in the abruzzi apennine, rather to the latium sites, included the near polesini cave, but this may be attributed to the geographical location and/or to the altimetrical position, than to the eventual chronological correlation with mora cavorso cave. at polesini cave (radmilli, 1974) near tivoli, about 26 km nne of rome, in the lower aniene river valley, the fauna of a sequence that include the recent lateglacial is largely dominated by the red deer, always about 70% among ungulates, followed by wild boar, roe deer and equids with lower rates, while aurochs, chamois and ibex are just present, the marmot and the wolverine sporadically appear. at riparo salvini (alessio et al., 1993; alhaique & di camillo, 2007) near terracina, on the latium tyrrhenian coast, an epigravettian sequence referred to bølling temperate oscillation and that has provided radiometric dating between 12.400 ± 170 and 13.365 ± 190 years bp (14c not-calibrated dating), close to mora cavorso cave dating, the red deer is the more abundant specie with rate superior of 50%, followed by equids (about 10%) and other ungulates like roe deer, chamois, wild boar and ibex and with hare, aurochs and carnivores sporadic presence. in the lateglacial stratigraphic sequences of ortucchio cave, la punta cave, maritza cave (alhaique & recchi, 2001; alhaique, 2003; 2005), located at about 700 m a.s.l. on the hills surrounding the fucino basin, there is a large presence of small animals (especially at ortucchio, less at maritza), in particular hare, but marmot and stoat are also present; among the ungulates chamois and red deer prevail, followed by ibex, wild boar, roe deer and aurochs, with sporadic presence of equids, in particular e. hydruntinus. in the oldest sites of the area, tronci cave, maurizio shelter, ciccio felice cave (alhaique & recchi, 2003), with sequences referable in part to the last glacial maximum, the faunas are quite the same, but there is a clear prevalence of ungulates, among them equids are more abundant, marking a colder and drier climate compared to the subsequent periods. the preliminary analyses of the faunal remains from the “dig b2” and other archaeological contexts of mora cavorso cave have permit to define 15 taxa, divided into 5 orders, 10 families and 13 different genera of mammals. m. marmota and c. ibex are the most significant species both from the “sinkhole” and from the “dig b2” mammal assemblages, but is even important the c. elaphus presence, and a particular attention deserves also c. fiber, till now not signaled in lateglacial mammal assemblages of central italy, and the sure evidence of the italic hare. the “dig b2” mammal assemblage with marmot followed by red deer, ibex, chamois, wild boar and roe deer is referable to a moment less hard and humid of first data on the latest pleistocene mammals from mora cavorso cave (jenne, latium, central italy 139 the last glacial episode final phases (probably the first part of the lateglacial preceding the bølling allerød temperate oscillation), according to the cultural chronology and the radiometric dating. the “sinkhole” mammal assemblage with marmot and ibex, followed by the equids more abundant than red deer and wild boar, perhaps has to be referred to a different moment, more cold and arid. at least part of the animals from the “dig b2” has been introduced in the cave by epigravettian human groups frequenting the upper aniene river valley and the simbruini mounts during the latest pleistocene. these data on the latest pleistocene mammal faunas from mora cavorso cave, suggest some chronological, climatic and environmental indications that will be adequately investigated and better outlined during the prosecution of the archaeological and palaeontological searches. acknowledgements we are grateful to the “soprintendenza per i beni archeologici del lazio”, in particular to annalisa zarattini, which allowed the access to the fossils and to two anonymous referees for the useful suggestions that improved the quality of the manuscript. we thank also carmelo petronio, olga rickards and raffaele sardella for their support. references alessio m., alhaique f., allegri l., bietti a., branca m., d’arpino a., improta s., kuhn s., palmieri a.m. & preite martinez m. (1993) new results on the upper paleolithic site of riparo salvini (terracina, italy). quat. nova, 3, pp. 105-150. alhaique f. (2003) the role of small carnivores in the accumulation of bones in archaeological deposits: the case of the fucino basin sites (central italy). archeofauna, 12, pp. 61-71. alhaique f. (2005) strategie di occupazione nelle grotte del fucino (abruzzo) durante il paleolitico superiore: il caso di grotta maritza (aq). in: i. fiore, g. malerba & s. chilardi (eds), atti del 3° convegno nazionale di archeozoologia (siracusa 3-5 novembre 2000), studi di paletnologia, n.s., 1, pp. 181-190. alhaique f. & di camillo f. (2007) le faune di riparo salvini (terracina, lt). atti i.i.p.p., xl, pp. 354357. alhaique f. & recchi a. (2001) la grotta di ortucchio e il fucino alla fine del paleolitico: analisi tafonomica e zooarcheologica delle mammalofaune e delle avifaune. atti del 2° convegno “il fucino e le aree limitrofe nell’antichità”, pp. 56-69, archeoclub d’italia marsica, avezzano (l’aquila). alhaique f. & recchi a. (2003) sfruttamento delle risorse faunistiche durante le fasi più antiche dell’occupazione nel fucino. atti i.i.p.p., xxxvi, pp. 53-64. amori g., battisti c. & de felici s. (2009) i mammiferi della provincia di roma. dallo stato delle conoscenze alla gestione e conservazione delle specie. provincia di roma, stilgrafica, roma, 350 pp. amori g., contoli l. & nappi a. (2008) fauna d’italia. mammalia ii. erinaceomorpha, soricomorpha, lagomorpha, rodentia. edizioni calderini de il sole24 ore, milano, 736 pp. boitani l., lovari s. & vigna taglianti a. (2003) fauna d’italia. mammalia iii. carnivora artiodactyla. calderini, bologna, 434 pp. bökönyi s. (1970) a new method for the determination of the number of individuals in animal bones material. am. j. arch., 74, pp. 291-292. boscato p. (1996) vado all’arancio (massa marittima, gr). studio delle faune. rass. arch., 13, pp. 159176. capasso barbato l., minieri m.r. & scarano m. (1991) paleogeografia dei mammiferi “freddi” del pleistocene medio-superiore e superiore italiano. atti accademia peloritana dei pericolanti, 67, suppl. 1, pp. 231-259. cassoli p.f. (1977) upper palaeolithic fauna at palidoro (rome): 1955 excavations. quaternaria, 19, pp. 187-196. cerilli e. & brocato g. (1998) the upper palaeolithic deposit of valle arcione (castel d’asso, viterbo, italy). atti u.i.s.p.p., xiii, 2, pp. 681-685, forlì. conti n, petronio c. & salari l. (2010) the equids of the late pleistocene of “tana delle iene” (ceglie messapica, brindisi, southern italy). boll. soc. paleont. it., 49, pp. 227-236. damiani a.v., catenacci v., molinari v.,tilia a. & panseri c. (1998) carta geologica d’ italia alla scala 1/50.000, foglio 376 “subiaco”: note illustrative. servizio geologico nazionale, 55 pp. esu d., de stefani m., gallini v., ghesini d., guerreschi a., gurioli f., magnatti m., muratori s., peresani m., silvestrini m. & veronese c. (2006) stratigrafia, paleontologia ed evidenze culturali del sito epigravettiano di cava romita (appennino marchigiano). studio dei materiali provenienti dagli scavi di recupero 1978-79. riv. sci. preist., 56, pp. 83-125. halley d.j. & rosell f. 2002 the beaver’s reconquest of eurasia: status, population development and management of a conservation success. mamm. rev., 32, pp.153-178. masini f. & lovari s. 1988 systematics, phylogenetic relationship, and dispersal of the chamois (rupicapra spp.). quat. res., 30, pp. 339-349. masseti m., mazza p., rustioni m. & sala b. 1995 large-sized ungulates at the late pleistoceneholocene transition: an overview. atti del 1° convegno nazionale di archeozoologia (rovigo, 5-7 marzo 1993). padusa quaderni, 1, pp. 89-96. palacios f. 1996 systematics of the indigenous hares of italy traditionally identified as lepus europaeus pallas 1778 (mammalia: leporidae). bonn. zool. beitr., 46, pp. 59-91. passacantando d. (2009) il campione neolitico dei resti scheletrici rinvenuti a jenne (roma). unpublished thesis in biology and human evolution, university of rome “tor vergata”. pennacchioni m. & tozzi c. (1985) l’industria epigravettiana del riparo biedano a norchia (viterbo). in: m. liverani, a. palmieri & r. peroni (eds), studi l. salari, d. passacantando & m.f. rolfo 140 di paletnologia in onore di salvatore m. puglisi, pp. 647-662, roma. petronio c., di canzio e. & salari l. (2007) the late pleistocene and holocene mammals in italy : new biochronological and paleoenvironmental data. palaeontographica, abt. a, 279, pp. 147-157, stuttgart. phoca cosmetatou n. (2004) a zooarchaeological reassessment of the habitat and ecology of the ibex (capra ibex). in: r.c.g.m lauwerier & i. plug (eds), the future from the past. archaeozoology in wildlife conservation and heritage management. proceedings 9th icaz conference, durham 2002, pp. 64-78, oxbow books, oxford. radmilli a.m. (1974) gli scavi nella grotta polesini a ponte lucano di tivoli e la più antica arte nel lazio. sansoni, firenze, 131 pp. radmilli a.m. (1977) storia dell’abruzzo dalle origini all’età del bronzo. collana studi paletnologici, giardini, pisa, 460 pp. ravazzi c., peresani m., pini r. & vescovi e. (2007) il tardoglaciale nelle alpi italiane e in pianura padana. evoluzione stratigrafica, storia della vegetazione e del popolamento antropico. il quaternario, 20, pp. 163-184. rolfo m.f., mancini d., salari l. & zarattini a. (2010) la grotta di “mora cavorso” (jenne, roma): nuove ricerche. in: g. ghini (ed.), lazio e sabina, 6. atti del sesto incontro di studi sul lazio e la sabina, pp. 11-17, quasar, roma. rolfo m.f., salari l. & zarattini a. (2009) nota preliminare sulle indagini archeologiche presso la grotta “mora di cavorso” (jenne, roma). in: g. ghini (ed.), lazio e sabina, scoperte scavi e ricerche, 5. atti del quinto incontro di studi sul lazio e la sabina, pp. 15-22, l’erma di bretschneider, roma. sala b. (2007) mammalofaune tardoglaciali dell’italia continentale. in: f. martini (ed.), l’italia tra 15.000 e 10.000 anni fa. cosmopolitismo e regionalità nel tadoglaciale, pp. 21-38, museo fiorentino di preistoria “paolo graziosi” edifir, firenze. salari l., zarattini a. & rolfo m.f. (2009) nota preliminare sulla fauna neolitica della grotta mora di cavorso (jenne, lazio). abstracts del 6° convegno nazionale di archeozoologia, parco dell’orecchiella (lucca), 21-24 maggio 2009, p. 101. tagliacozzo a. (2003) archeozoologia dei livelli dell’epigravettiano finale di grotta romanelli (castro, lecce). strategie di caccia ed economia di sussistenza. in: p.f. fabbri, e. ingravallo & a. mangia (eds), grotta romanelli nel centenario della sua scoperta (1900-2000), pp. 169-216, congedo, galatina (lecce). ucelli gnesutta p., boschian g., cantoro g.l., castiglioni e., dini m., maspero a., petrinelli pannocchia p. & rottoli m. (2007) i livelli epigravettiani della grotta delle settecannelle (viterbo). riv. sci. preist., 56, pp. 127-183. wilkens b. (1991) resti faunistici ed economia preistorica nel bacino del fucino. atti del convegno “il fucino e le aree limitrofe nell’antichità”, pp. 147153, archeoclub d’italia marsica, roma. ms. ricevuto il 5/05/2010 testo definitivo ricevuto il 28/8/2010 ms. received: may 5, 2010 final text received: august 28, 2010 amq_forno finale 1 available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 28 (1), 2015, 5 27 stratigraphic and tectonic notes on the villafranca d’asti succession in type-area and castelnuovo don bosco sector (asti reliefs, piedmont). m. gabriella forno1-2, marco gattiglio1, cesare comina1, diego barbero1, adele bertini3, alfredo doglione1, franco gianotti1, andrea irace4, edoardo martinetto1, alberto mottura5, benedetto sala6 1 dipartimento di scienze della terra, università di torino, torino, italy 2 natrisk interdipartimental centre, università di torino, grugliasco, italy 3 dipartimento di scienze della terra, università di firenze, firenze, italy 4 istituto di geoscienze e georisorse, cnr, torino, italy 5 dipartimento di scienze della vita e biologia dei sistemi, università di torino, torino, italy 6 museo di paleontologia e preistoria, università di ferrara, ferrara, italy corresponding author: m.g. forno <gabriella.forno@unito.it> abstract: interest in the sedimentary succession in the asti reliefs fostered research since the beginning of the science of geology, before the designation by pareto (1865) of the “piano villafranchiano” and its type area at villafranca d’asti. the villafranchian sediments have been the subject of many recent investigations, which focused largely on the palaeontology of vertebrates and plant remains. geological surveys in the type area and in the castelnuovo don bosco sector revealed that the sedimentary succession is stratigraphically and tectonically more complex than was previously supposed. the succession exhibits an important hiatus represented by an angular unconformity that allows for the differentiation of two complexes containing different facies. the lower complex (lc)(delta facies), which contains abundant fossils (vertebrates, pollen and plant remains, molluscs), is referred to the piacenzian. the upper complex (uc) (fluvial facies), which is very sparsely fossiliferous, is uncertainly referred to the calabrian. new surveys in the type area of villafranca d’asti involve an integration of the stratigraphic and paleopedologic framework. these studies focused on a paleosol, including bodies of colluvial sediments, that lie on the unconformity which separates the two complexes. all the sediments display significant deformation as indicated by the overall geometry of the succession, the presence of soft sediment deformation, the localized presence of deposits produced by gravitational reworking of the deltaic sediments and finally by the presence of deformational zones (t. traversola deformation zone, c. fagliaverde fault zone and castelnuovo fault zone) and faults (gariglio fault, serra fault and agagliate fault). new data regarding the t. traversola deformation zone suggest its southern extension, confirming the strike-slip nature. the critical revision of mammal-fauna and microand macrobotanical evidence permitted to discuss the chronological and stratigraphical context of such sedimentary succession. keywords: sedimentary succession, plio-pleistocene, asti reliefs, villafranca d’asti, italy 1. introduction interest in the sedimentary succession in the asti reliefs has promoted research since pareto (1865), who defined the “piano villafranchiano” and its type area at villafranca d’asti. pareto considered the villafranchiano a continental stage which was first correlated to the marine calabrian stage of gignoux (1916). during the18th i.g.c. of london (1948), the calabrian was placed at the base of pleistocene and consequently the villafranchiano became the earliest continental stage of the pleistocene. the recognition of a great number of continental vertebrates and other significant fossil findings in the transitional deposits outcropping in villafranca d’asti and surrounding areas allowed to develop a better knowledge of their mammal assemblages. the paleontological studies carried out from pioneering works in the 1960s until the end of the last century allowed to define the villafranchian mammal age as a biochronological unit. this unit represents a subdivision of the geological time of evolutionary stages of faunal assemblages and dispersal events (rook & martinez-navarro, 2010 and references therein). the villafranchian mammal age, and its chronological subdivisions, according to the international stratigraphic scale, corresponds to the late pliocene (piacenzian, from 3.5 to 2.6 ma) and to the early pleistocene (gelasian and calabrian p.p., from 2.6 up to 1.1 ma, near to the base of jaramillo subchron). as a consequence, the term “villafranchiano” lost its original chronostratigraphic significance: the name “villafranchian succession” is maintained solely for historical reasons to indicate the various sedimentary successions outcropping in the villafranca basin and in the castelnuovo don bosco sector, including transitional deposits between the pliocene marine succession and the continental sediments. the various “villafranchian” sedimentary successions fall within the piacenzian, gelasian and calabrian stages, utilizing the current chronostratigraphic scale and the connected stages nomenclature (gibbard et al., 2010). most of the studies focused on localized outcrops 6 forno m.g. et al. that were selected for their lithostratigraphic features, mineralogical composition or peculiar vegetal content. although the villafranchian succession is among the most studied quaternary continental sequences in italy its interpretation is still very problematic, mainly due to a complex and not yet completely understood stratigraphy. several units once defined as “villafranchian” were later designated as not belonging to the type section or were confused with the overor underlying sediments (fig. 1). thus, the stratigraphic meaning of the entire succession has repeatedly changed over time. in this uncertain stratigraphic framework, a revision of the entire set of geological knowledge has allowed to address and partly solve the primary questions (carraro ed., 1996). along with many other studies, that were the topic of an international conference in 1994, new geological mapping throughout the entire type area helped to solve most of the remaining questions (boano & forno, 1996). subsequent surveys included a new section north of the historical type-area, near castelnuovo don bosco (boano et al., 1997; boano & forno, 1999). this later work resulted in good agreement with the revised typearea, thus confirming the new updated stratigraphy. new findings regarding the structure in the succession also provided new insights, due to the peculiar deformation observed in the castelnuovo section itself. the present study provides for an improved and integrated stratigraphic framework by the use of different approaches and methods (geology, pedology, structural geology, mammal fauna, palynology, carpology). new findings include a previously unrecognized paleosol, often associated with unknown concentrations of fossil vertebrate remains, which are present in the succession at the top of the lower complex. moreover, the ancient fossil remains were revisited based on modern knowledge and the current chronostratigraphic framework. the structural study, still in progress, includes identification of soft-sediment deformation that diffusely involve the sediments and mapping the local faults. specifically, this work clarifies the structural interpretation of the t. traversola deformation zone, which offsets the stratigraphic succession of the type-area and of the castelnuovo don bosco sector. 2. geomorphologic and geologic setting the hilly relief of the central piedmont consists of the turin hill and the monferrato reliefs on the northern side, the poirino plateau, the asti reliefs and the alesfig. 1 various designations and subdivisions of the “villafranchian succession” at various times. the current units (ferrere, san martino, gherba and maretto) are reported on the left side of the figure. only the central unit of the succession (now the s. martino unit) was always regarded as part of the succession defined by pareto. the stratigraphic significance of the sequence also changed over time. 7 stratigraphic and tectonic notes on the villafranca d’asti succession ... sandria plateau in the centre, and the langhe reliefs on the southern side (fig. 2). the turin hill-monferrato hills, which ranges in elevation from 700 to 300 m a.s.l., form an e-w-oriented ridge. this ridge consists of a terrigenous eocenepliocene marine succession with a thin, discontinuous, discordant pleistocene fluvial cover. the langhe hills, which slope downward from the south (exceeding 800 m a.s.l.) to the north (average elevation of 300 m a.s.l.), form the foothill region of the ligurian alps. these reliefs consist of a terrigenous marine succession of oligocene -miocene age. turin hill and the monferrato are cut by a nnw-sse-trending transpressive deformation zone, the rio freddo deformation zone (piana & polino, 1995). fig. 2 structural map of the piedmont hilly area, bordered to the nw and n by the apennine padane thrust front. the “villafranchian succession” type-area and castelnuovo don bosco sector are shown. these sediments are involved in the t. traversola deformation zone (ttdz) with a prevailing dextral strike-slip displacement. the rio freddo deformation zone (rfdz), the vilalvernia-varzi fault (vv) and the sestri voltaggio zone (svz) are also reported. the contiguous savigliano, asti and alessandria basins correspond to the low central hilly sector, where the asti syncline developed during the pliocene. in the pleistocene, the ancient po and tanaro rivers exploited this depression, thereby shaping the poirino plateau and the asti reliefs. 8 forno m.g. et al. the villafranca d’asti succession type-area and the castelnuovo don bosco section are located in the centre of these reliefs, where the poirino plateau (elevation 230-325 m a.s.l.) and the asti reliefs (elevation 130-320 m a.s.l.) occur. they are the geomorphic expression of the asti syncline, which represents the extension of the savigliano and alessandria basins (fig. 2). this structure involves the littoral marine asti sand (lower pliocene) and the deltaic and fluvial villafranchian succession (piacenzian and calabrian) and is buried by a thin cover of fluvial sediments (middle-upper pleistocene). a n-s-trending scarp is evident in the western part of this syncline. this feature divides the poirino plateau, which slopes gently to the west, and the asti reliefs, which display an articulated morphology. this scarp runs nearly parallel to the tectonic structure referred to as the t. traversola deformation zone, which offsets both the pliocene and pleistocene sequences (gattiglio et al., 2015). the asti reliefs correspond, therefore, to the central exhumed portion of the asti syncline, which is a basinscale fold with a strongly arched axial trace (fig. 2). these reliefs expose a succession consisting of shallow-water marine sediments (asti sand, zanclean) and deltaic and fluvial villafranchian deposits differentiated into the lower complex (lc) (piacenzian) and the upper complex (uc) (calabrian), respectively in upward succession. this sequence is unconformably overlain by a discontinuous, thin cover of fluvial sediments of middle pleistocene-holocene age. from the asti reliefs, the syncline axis plunges to the sw and e, and the pliocene successions are overlain by the less-deformed sub -horizontal quaternary deposits of the savigliano and alessandria basins. the asti syncline records the presence, during the pliocene, of a large satellite basin that developed between the alps and apennine systems, at the back of the apennine padane thrust front. the evolution of this basin was controlled by the continuous growth of the turin hill and monferrato arc and by the progressive uplift of the southern langhe domain (mosca et al., 2009; irace et al., 2010). this basin evolution related to the activity of north-verging thrust systems and highangle strike-slip faults (pieri & groppi, 1981; mosca et al., 2009). 3. previous work an extensive geological and paleontological literature regards the succession of the asti reliefs. it began in the 1800s with the earliest published reports of fossil vertebrates (cuvier, 1806; amoretti, 1808). most of the nineteenth-century papers concerned the vertebrate fossils in this area (borson, 1820; 1823; 1930; sismonda, 1849; gastaldi, 1861). sismonda and gastaldi published their discovery of complete skeletons of mastodons at san paolo solbrito and ferrere d’asti. an excellent opportunity to study these fossils was provided by the excavation of a wide trench for the turin-genoa railway: many fossils of vertebrates and terrestrial molluscs were exposed (baretti, 1880a; 1880b; 1880c; sacco, 1884; 1886a; 1886b; 1888). at approximately the same time, stratigraphers described the sedimentary succession. the main research was by pareto (1865), who was responsible of the establishment of the “piano villafranchiano” based on transitional sedimentary deposits overlying the pliocene 9 stratigraphic and tectonic notes on the villafranca d’asti succession ... fig. 4 detailed geological map showing the interfingering lenses at the contact between the littoral and deltaic sediments. outcrop (dark color) and interpolating (light color) of the asti sand (1: fine-medium planar bedded sand, zanclean), ferrere unit (2: cross bedded coarse sand) and the san martino unit (3: alternating silt and sand) forming the lc (piacenzian). the area is located in the southeast corner of the type-area (a in fig. 3). ___________________________ fig. 3 geological map of the villafranchian succession, which consists of two sedimentary complexes that are separated by the cascina viarengo surface (type-area) and the cascina guerrina surface (castelnuovo don bosco sector) and are offset by fractures and faults. the dashed sectors indicate the detailed areas reported in fig. 4 (a), fig. 11 (b), fig. 24 (c) and fig. 25 (d). marine sands 1. sacco (1886c; 1890) introduced a subdivision of the stratigraphic succession by distinguishing the lower sediments, which consist primarily of cross-bedded sand and were named the piano fossaniano, from the remainder of the succession. this interpretation was also used in the first edition of the geological map of italy (1:100,000 scale) (sacco, 1922). the stratigraphic succession and its palaeontology were again described by martinis (1949), gabert (1962) and selli (1967). these authors, although they regarded the succession as undifferentiated, reported the presence of various facies attributed to littoral and deltaic environments. a new impetus to studies of the villafranca d'asti area was provided by the opening of quarries for the construction of the a21 turin-piacenza motorway. pavia (1970) published a detailed study of the succession exposed in the arboschio quarry (cantarana) (see fig. 5); this study focussed on the fossils of plants, vertebrates and marine molluscs. francavilla et al. (1969; 1970) and francavilla & tomadin (1970) focused on the palynology and paleobotany of the sequence based on a detailed analysis of the exposures in other quarries that were open at that time (cantarana, crotino, arondelli, fornace rdb) and were subsequently restored. azzaroli & vialli (1971) studied the same quarries and published a summary study of the villafranchian succession and its fossil vertebrates 2. at approximately the same time, surveys were performed for the second edition of geological sheets 68 "carmagnola" (petrucci & tagliavini, 1968) and 69 "asti" (boni et al., 1969) of the geological map of italy. in these works, the presence of an erosional surface between the villafranchian succession and the overlying quaternary deposits was reported. subsequently, carraro et al. (1982) suggested the presence of an angular unconformity in the villafranchian type section that was recognizable on a regional scale but not on more-detailed scale. a detailed geological survey of the entire type-area allowed for a complete reconstruction of the geometry of the various geologic units of the villafranchian succession and clarified certain issues (carraro ed., 1996). this research included the collection of sedimentological, paleontological, structural, geophysical and geotechnical data. the main results were: a detailed geological map of the entire type-area, which provided a comprehensive understanding of the geology based on more than scattered outcrops; a reconsideration, based on modern stratigraphic criteria, of the villafranchian succession defined by pareto; and a better locating of the remains and a refined chronologic interpreting of the fossil record. this reinterpretation resulted in the definition of two main complexes (lower complex and upper complex), which represent deltaic and fluvial palaeoenvironments, respectively, and are separated by an erosional angular unconformity that is designated as the cascina viarengo surface. the lower complex was referred to the middle pliocene and of the upper complex was referred to as lower pleistocene. an investigation on the climatic conditions during deposition of the lower complex based on the fossil plant assemblages in the san martino unit suggested a warm temperate palaeoclimate (martinetto & mai, 1996). further study of the rdb section confirmed that the lower complex marks the “closure” of the pliocene regressive cycle and is constrained to the piacenzian (lindsay et al., 1997). magnetostratigraphic data (gauss chron) confirmed this age of the lower complex (boano et al., 1999b). the strong deformation of the villafranchian succession was also described in a study of the soft-sediment deformation in the deltaic complex (boano et al., 1997). an extension of the geological survey was also per 10 forno m.g. et al. fig. 5 most typical facies of the ferrere unit characterized by cross bedded coarse grained sand, with laminae dipping in opposite directions and fragments of marine molluscs. massive bioturbated sand is also abundant near the bottom and the top of the log. thin lenses of fine sand with ripples area also present in the medium part of the log. 1: bioturbated sand; 2: fragmented marine molluscs and minute gravel and clay-chips; 3: vertebrate remain. cantarana quarry in ferrere d’asti (central type-area). —————————— 1) these deposits, which were regarded as undifferentiated, consist primarily of stratified silt with horizontal laminations, cross-bedded sand and gravel and massive silt. the section at villafranca d'asti was therefore designated the type section of this unit.     2) none of these studies included an analysis of the entire stratigraphic succession in the type area; they focused instead on the succession in specific quarries and included no correlations between the various sections. formed in the castelnuovo don bosco sector, where both the stratigraphy of the villafranchian succession and the structural features are more complex than those in the type-area (boano & forno, 1999). this research confirmed the findings of the previous revision and produced further evidence of strong deformation of the sediments. the findings presented in the map of the castelnuovo don bosco sector (fig. 2) were confirmed with the recent geological survey for the official map (dela pierre et al., 2003; festa et al., 2009): the lower complex includes tide-dominated deltaic deposits, which are referred to as the ferrere sands (5-25 m thick), and fine-grained deltaplain and lacustrine deposits, which are referred to as the “san martino silt” (up to 60 m thick). the upper complex consists of fluvial gravel and sand designated as the “morialdo syntem”. this subdivision into two main stratigraphic units and the presence of a regional angular unconformity were also reported as a result of basinscale hydrostratigraphic studies that focused on subsurface reconstructions beneath the plains surrounding to the asti reliefs. a recent study of the southern edge of the alessandria basin (fig. 2) (irace et al., 2012) provided evidence that the hiatus represented by this unconformity may be the result of a series of erosionaldepositional events that started in the late piacenzian and continued in the gelasian. part of the continental record corresponding to this stratigraphic gap may be locally preserved. a detailed integrated study of the subsurface west of the villafranca d'asti area suggested a gelasian age of the c. viarengo unconformity (vigna et al., 2010), based on a possible correlation with the gelasian surface in the po foreland basin (ghielmi et al., 2010; 2013). 4. stratigraphic features of the villafranca d’asti succession in the type area and the castelnuovo don bosco sector in the type-area and in the castelnuovo don bosco sector, the villafranca d’asti succession generally rests conformably on the asti sand. this sand outcrops in the marginal sectors on the low parts of the slopes and exhibits a visible thickness of tens of metres (fig. 3). the asti sand consists of poorly bedded, mediumto fine-grained, horizontally laminated sand with localized current structures (symmetrical ripples). these deposits are generally yellow (2,5 y 8/6 munsell) and are strongly cemented, particularly where fossils are abundant. they are often rich in coastal marine molluscs concentrated in beds that are centimetres to tens of centimetres thick (see fig. 12). the fossils are often complete, including their primary anatomic connection. the horizontal parallel lamination, the coastal fossils and the local tidal structures indicate a littoral marine environment. the fossil assemblage suggests an early pliocene age (festa et al., 2009). as mentioned above, the overlying succession consists of two complexes. its sedimentologic features indicate the presence of various units in each complex. 4.1. the two sedimentary complexes (lc and uc) the detailed geological survey of the type area revealed the stratigraphic framework of the succession, which was previously regarded as undivided (boano & forno, 1996; 1999). the succession is subdivided into two complexes, the lower complex (lc) and the upper complex (uc), which are separated by angular unconformities, specifically, the cascina viarengo surface (type-area) and the cascina guerrina surface (castelnuovo don bosco sector) (fig. 3). 4.2. stratigraphic subdivision of the lc the ferrere unit, which comprises the basal unit of the lc, is exposed locally along the edges of the typearea and in the central castelnuovo don bosco sector (fig. 3). this unit rests conformably on the underlying marine sediments (asti sand); this contact may be gradational, based on interfingering or alternating lenses of the two units (fig. 4). the thickness ranges from 5 to 25 m. this unit consists primarily of cross-bedded coarse sand with laminae dipping in opposite directions (fig. 5). there are beds rich in centimetre-long fragments of marine molluscs and minute gravel and clay-chip (fig. 11 stratigraphic and tectonic notes on the villafranca d’asti succession ... fig. 6 ferrere unit cross-bedded coarse sand with laminae dipping in opposite directions, rich in clay-chips. buttigliera d’asti quarry (northwestern corner of the castelnuovo don bosco sector). 6). the textural features and the cross bedding are consistent with deposition of coarse sediment on a delta front, where the re-deposition of the shells of asti sand may have been frequent. the bedding suggests deposition associated with tidal channels, typically with opposite directions (fig. 6). massive bioturbated sand is also abundant (fig. 7). the ferrere unit was formed in the shallow water of a deltaic system in which coarse sand were deposited and strong reworking of sediments occurred. thin lenses of fine sand with ripples (fig. 5), alternating with silt, are locally also associated with the more-typical facies. these features are indicative of deposition in lateral deltaic areas, where there was a slower rate of sedimentation. the ferrere unit, in addition to fragments of marine molluscs, includes numerous fragments of continental vertebrates (primarily mastodon and rhinoceros remains as specified in paragraph 6) and plants (as specified in paragraph 7) that were transported by rivers along the deltaic front. the sedimentologic and paleontologic features are consistent with a progradational delta front grading into a beach system. petrographic analysis indicates that the clasts consist primarily of quartzite, conglomeratic quartzite, gneiss, dolomite, micaschist and gabbro, which indicate a genetic linked to the tanaro basin. the overlying san martino unit, which constitutes the upper part of the lc, is exposed throughout the typearea and in the central castelnuovo don bosco sector (fig. 3). this unit rests conformably on the ferrere unit and the contact is often eteropic. the thickness of the san martino unit ranges from 20 to 65 m. the san martino unit consists primarily of clayey silt interbedded with sand (see fig. 8). these sediments form the most distinctive unit of the villafranca d’asti succession: they display the most characteristic facies and are the most abundant in fossils (fossil vertebrates, lacustrine and terrestrial molluscs and plant remains). the unit consists predominantly of planar bedded to massive clayey silt that is typically grey (fig. 9). the bedded silt contains scattered leaf and reed imprints, plant fragments, stump in life position, roots and pollen (fig. 10) and local levels of lignite. these fossils are typical of swamp environments where the mineral fraction and vegetal remains settled out of the water column. trough cross-bedded sand is also present in channel fills. these deposits locally contain fossils of continental vertebrates that are often preserved as entire carcasses (campanino et al, 1994) (see fig. 19). the sandy texture, cross bedding and local vertebrate remains suggest a stream paleoenvironment. this unit locally displays decimetre-thick organic paleosols, rich in roots, pollen, terrestrial molluscs and concretions (fig. 8). the sedimentologic and palaeontologic features of the san martino unit suggest that these sediments were deposited on a deltaic plain. specifically, the silt was deposed in coastal swamps, and the sand filled the deltaic distributory channels. the very compact appearance of these sediments, which differs markedly from that of the soft uc, and their homogeneous grey color, which also differs from the various colours of uc, are the typical features that allow for distinguishing this unit from 12 forno m.g. et al. fig. 7 massive bioturbated sand of the ferrere unit. outcrop n of ronco village. southeast corner of the type-area. fig. 8 the cascina viarengo erosional surface divides the san martino unit (silt alternating to fine sand) (lc, piacenzian) by the c. gherba unit (gravel coarse sand) (uc, calabrian). 1: soft sediment deformation; 2: root; 3: organic paleosol; 4: terrestrial and lacustrine mollusc; 5: leaf imprint. cascina san martino quarry in villafranca d’asti (central type-area). the other predominantly silty facies of the sedimentary succession. 4.3. erosional surfaces the top of lc is cut by distinct erosional surfaces (fig. 3). the c. viarengo surface extends across the entire type area and displays a predominantly subhorizontal morphology with local irregularities (fig. 11). the cascina guerrina surface is restricted to the castelnuovo don bosco sector and exhibits a concave shape. the absence of unequivocal stratigraphic markers did not allow for the assignment of a single name to the two surfaces, although there is evidence for correlating the two surfaces. these erosional surfaces comprise an angular unconformity between the lc, forming a syncline with axis dipping towards the west, and the uc, constituting instead a syncline with sub-horizontal axis (see fig. 26). the over-consolidation of the clays levels of the lc suggests that a remarkably thick portion of sediments was removed by erosion (up to 100 metres) (carraro ed., 1996). it is possible, therefore, to infer that these surfaces deeply truncate the lc. the deposits below and above the erosional surface differ markedly, which confirms the importance of the erosional phenomena (fig.12). these differences include the type of depositional environment (which shows a switch from deltaic to fluvial), the fossil content (shift from very fossiliferous to essentially nonfossiliferous), the degree of lithification (shift from the very compact lc to the soft uc), the deformation structures (from the very deformed lc to the less-deformed uc), and the degree of weathering (from the locally weathered lc to the strongly weathered uc). this erosional surface was shaped by a continental stream network. more than one fluvial system likely developed at different times, suggesting a polygenetic nature of this erosional feature. 4.4. stratigraphic subdivision of uc the cascina gherba unit, which directly overlies the cascina viarengo surface, is present across the typearea. the thickness of this unit is relatively uniform, ranging from 4 to 15 m. it is composed of grey to white gravelly sand and sand with large-scale trough crossbedding (fig. 9). a carbonate-rich bed (from a few decimetres to a metre thick) typically underlies zones of permeability contrast with other sediments. the sedimentologic features of the facies suggest an alluvia plain dominated by braided streams. petrographic analysis of the gravel indicated that the clasts are primarily composed of quartzite, conglomeratic quartzite, gneiss, dolomite, micaschist and gabbro, which indicate a genetic link with the tanaro basin. these sediments did not directly provide fossil remains. only a few vertebrate teeth of elephant preserved in the regional museum of natural science of turin (zuffardi, 1913), saving a little typical c. gherba sediment attached to the remains, doubtfully comes by this unit. the maretto unit is widespread across the type-area and forms the top of the ridges. the thickness isrelatively uniform, approximately 50 metres. its contact with the cascina gherba unit is conformable and gradational, based on interfingering of the two units. the maretto unit consists of homogeneous clay silt, massive or with a faint planar bedding (fig. 13). these sediments are mottled, with color that varies from brown (7,5 yr 5/8 munsell) to grey. they are often rich in carbonate concretions and display pseudogleys (fig. 14). these pedogenetic features are observed not only in the surficial exposures but extend throughout the unit. the maretto unit is interpreted as the product of the fine-grained sedimentation by rivers with a high amount of suspended load in an alluvial plain associated with river flooding. the clay texture, the predominant brown 13 stratigraphic and tectonic notes on the villafranca d’asti succession ... fig. 9 alternating planar bedded silt and cross-bedded fine sand of the san martino unit (lc), separated by the coarse, cross-bedded sand of the c. gherba unit (uc) by the cascina viarengo erosional surface. the newly exposed sediments (at the base of the outcrop) preserve the typical grey colour of the san martino unit, not involved in the surficial weathering that involves the exposed for longer sediments, whose yellowish color is due to the lengthy subaerial exposure. cascina san martino quarry in villafranca d’asti (central type-area). fig. 10 leaf imprint in the cascina san martino silt. detail of the cascina san martino quarry in villafranca d’asti (central type-area). color, the abundant carbonate concretions and the presence of pseudogleys indicate strong weathering of the deposits that involved the entire thickness. these pedogenetic phenomena occurred over a long period of time, indicating pedogenesis contemporaneous with sedimentation. the morialdo unit is restricted to the castelnuovo don bosco sector directly above the cascina guerrina surface (fig. 3). this unit is composed of gravelly sand and sand, generally grey, with large -scale trough cross-bedding. its sedimentologic features are very similar to those of the cascina gherba unit, suggesting deposition by braided watercourse for these deposits. the petrography yielded a distinct composition: the clasts are composed of quartzite, serpentinite, gneiss, micaschist, dolomite, gabbro and prasinite. the abundance of green stones indicates a source different from that of the cascina gherba unit of the type-area and a likely connection with the hilly network or an ancient course of the po river. the buttigliera unit is also restricted to the castelnuovo don bosco sector. it also consists of homogeneous clayey silt with mottled colouring and abundant carbonate concretions, similar to the maretto unit. the presence of green stones is indicative of a source in an ancient hilly network or of an ancient course of the po river. 5. paleosol between the two complexes recent discoveries of different contexts of vertebrate remains in the area, including rhinos (campanino et al., 1994) and monkeys (gentili et al., 1998), provide additional biostratinomic and taphonomic evidence for differentiating the local fossil assemblages. abundant fossil concentrations just below the unconformity between the lc and uc suggest peculiar, constraining, nearly stable depositional conditions (boano et al., 1999b). further geological surveys conducted as part of the present study indicate that these fossil concentrations are associated with weathered sediments not identified in earlier studies. these deposits, which are up to six metres thick, are characterized by a strong brown colour (7,5yr 5/8 munsell), diffused clay skins and a strong cementation by iron oxides, representing a paleosol. it displays the typical stratigraphic position along the unconformity and wide diffusion in the entire western sector of the type-area. there are other discontinuous, thin deposits associated with this paleosol. they do not correlate with any single facies of the villafranchian succession and instead are marked by a mixture of features that suggests a colluvial origin. due to the poor exposures, suitable sections with paleosol horizons are rare. therefore, a horizontal trench was excavated near the fornace rdb in villafranca d’asti to provide subsurface data (fig. 15). this trench was approximately 40 metres long and 2.5 metres deep and was excavated to expose the top of the lc, the cascina viarengo surface and the bottom of the uc. the lower part of the trench exposed the top of the weathered, brown, clayey material of the paleosol developed on the lc (p in fig. 16). the middle and upper parts of the trench exposed a lenticular body up to 2 metres thick that extended tens of metres laterally and lenses, each a few decimetres thick, of mixed sand, silt and clay of various colours and coherence separated by clear contacts. this sequence indicates the presence of a succession of various colluvial bodies. the low colluvial body (1 in fig. 16), located in a depression at the top of the lc, is composed of clayey silt of a strong brown colour (7,5yr 5/8) with grey mottles and pseudogleys and irregular centimetre-long fragments of red clay chips (5yr 3/3). the overlying colluvial body (2 in fig. 16) consists of a brownish-yellow matrix with grey mottles mixed with centimetre-long 14 forno m.g. et al. fig. 11 detailed map showing the subhorizontal arrangement of the cascina viarengo surface (2). outcrop (dark color) and interpolating (light color) of the piacenzian lower complex (1: san martino unit), the calabrian upper complex (3: cascina gherba unit; 4: maretto unit) and the middle-upper pleistocene (5) and holocene fluvial cover (6). villafranca d’asti in the central sector of the type-area (b in fig. 3). rounded brown concretions (fig. 17). the strong cementation of these two bodies by iron oxides suggests a subsequent weathering of these sediments, indicating a greater age and their involvement in the paleosol. the next highest colluvial body (3 in fig. 16) displays a homogeneous brownyellowish colour (10 yr 4/4) and a soft consistency. finally, silt and sandy silt covering the underlying colluvial bodies (4 in fig. 16) are yellowish to brown and very soft (fig. 17). the weak cementation of these two colluvial bodies by iron oxides suggests the absence of further weathering, indicating a more-recent age and their non-involvement in the soil developed on the lc. these nonweathered deposits are also ancient colluvial sediments included in the villafranchian succession. the framework is visible in the stratigraphic scheme in which the paleosol and the various colluvial bodies are positioned between lc and uc (fig. 18). this recurrent evidence (concentrations of fossil remains, paleosol and colluvial sediments) indicates that the development of the succession was more complex than previously thought, based largely on the geological significance of the unconformity separating the two complexes (see fig. 26). an old topographic surface developed at the end of the deltaic sedimentation, which indicates conditions of relative stability when extensive pedogenetic processes and little deposition occurred. the stratigraphic concentration and preservation of fossils was thus favoured by the slow accumulation of colluvial soil on the underlying horizons of the paleosol. the colluvial sequence marks the end of the deltaic aggradation (lc) and the start of general erosion (uc), which was also marked by a sharp stratigraphic transition to the overlying, discontinuous alluvial sedimentation. the features of this paleosol are compatible with a pronounced pedological event (likely some hundred of thousands years long). 6. vertebrate fossil remains during the revision of the villafranchian in the type area of villafranca d’asti, between 1992 and 1994 (carraro ed., 1996), vertebrate palaeontologists tried to order the fossil material that had been collected beginning in the second half of the 18th century, the greater part of which is preserved at the regional museum of natural science of turin and in basel (hurzeler, 1967). 15 stratigraphic and tectonic notes on the villafranca d’asti succession ... fig. 13 clayey silt with a hint of planar bedding, evidenced by different carbonate contents: the light horizons show a cementation and are rich of pedogenetic carbonatic concretions; the dark horizons (brown color 7,5 yr 5/8) appear strongly cemented by iron oxides and rich of peseudogleys. outcrop of maretto unit n of palazzo gianotti (central sector of the typefig. 14 the clayey silt with mottled colour of the maretto unit, rich in pseudogleys and mn concretions. detail of the outcrop n of palazzo gianotti (central sector of the type-area). fig. 12 stratigraphic sketch of the different units forming the villafranca d’asti typearea and castelnuovo don bosco sector. 1: marine molluscs; 2: fragmented marine molluscs; 3: bioturbated sand; 4: vertebrates; 5: lacustrine and terrestrial molluscs; 6: branch fragments; 7: plant frustules; 8: roots; 9: leaf and reed imprints; 10: levels of lignite; 11: stumps in life position; 12: concretions; p: paleosol. several bio-chronological notes were shared and, to place the mammal fauna from the area of villafranca d’asti in a wider biostratigraphic framework, researchers developed a table containing selected italian mammal fauna referred to villafranchian and galerian (masini et al., 1996). the discussion also concerned the definition of the term “villafranchian”, which was introduced by pareto in the 1865. vertebrate palaeontologists noted that this term had been used a long time, particularly in europe and north america, to indicate an “age of large mammals”. moreover, azzaroli (1977) had introduced the concept of the “faunal unit” as an internal subdivision of mammal ages, and proposed a definition of the “val triversa faunal unit”. this fu included all the local mammal fauna coeval with the pliocene fossils from the area of villafranca d’asti. today, the term “villafranchian” is widely used by vertebrate palaeontologists working across the holarctic region when referring to a specific “mammal age” (savage & russell, 1983), and triversa remains the only fu of the early villafranchian, which also includes a few of the local fauna of central italy, such as those of santa barbara (castenuovo dei sabbioni, arezzo) (gliozzi et al. 1997). the localities in the area of villafranca that have yielded the most significant fauna are cava arboschio, cascina arondelli, cascina crotino, cascina melona di roatto (fig. 19), cascina oggero, cascina viarengo, dusino, fornace r.d.b, s. paolo solbrito and val triversa (ambrosetti et al., 1996). the remains with certain stratigraphic position come from the lc (san martino unit), piacenzian. unfortunately, the large collections from the excavations for the construction of the railway in the 19th century and for the motor-way in the 1950s are not included among the fossil material of certain stratigraphic position. the latter was published by sismonda (1852), gastaldi 1860), sacco (1895), pavia (1970), francavilla et al. (1970), berzi et al. (1970), mottura & ardito (1992) and campanino et al. (1994) and is represented by only a few species: anancus arvernensis, mammuth borsoni, mesopithecus monspessulanus, stephanorhinus elatus (sin. s. jeanvireti) and sus cf. minor. only two remains not identified with certainty, a fragment of cervid antler and a tooth fragment of sus sp., are attributed with certainty to the uc, which is provi 16 forno m.g. et al. fig. 15 the trench located sw of villafranca d’asti (the village is located in the background of the photo) cut to study the paleosol between the lc and the uc. fig. 16 cross section along the trench sw of villafranca d’asti. on the lc (san martino unit, piacenzian) involved by the formation of the paleosol (p) ancient colluvial sediments are preserved in a wide depression (1 and 2), also involved by the paleosol. above, more recent colluvia occur (3 and 4), not involved by the paleosol. the cascina viarengo surface (vs) and the uc (cascina gherba unit, calabrian) are present at the top of the sequence. finally, near the current topographic surface, agricultural soil is visible (5). sionally assigned an early pleistocene, gelasian and/or calabrian age. exploration for the remains of small mammals in this complex was fruitless. many species are represented in the val triversa faunal unit. a few of these are typical of damp, wooded, subtropical environments, such as two mastodons, anancus arvernenesis and mammuth borsoni, a small suid, sus minor, a cercopithecus, mesopithecus monspessulanus, a lesser panda, parailurus hungaricus and a tapir, tapirus arvernensis. there were also other mammals adapted to living in open woodland or parkland terrain, such as the large rhino, stephanorhinus elatus, a heavily built antelope, leptobos stenometopon, and a medium-size cervid, pseudodama lyra. the carnivores are numerous: the mustelids baranogale helbingi and enhydrictis ardea, the viverrids megaviverra appennina and viverra pepraxi, a little forest bear, ursus minimus, a hyaena, chasmaporthetes lunensis, a cheetah, acinonyx pardinensis, and a saber tooth tiger, homotherium crenatidens. in addition, there are also several small vertebrates, primarily rodents of the early villanyian (a small mammal ages) (fejfar & heinrich, 1990). the presence of two mastodons together with new species characteristic of open woodland or parkland is particularly important for establishing correlations with other holarctic fauna. 7. the plant fossil remains 7.1. palynomorphs since 1969, palynological analyses have been performed by several authors (francavilla et al., 1969, 1970; francavilla & tomadin, 1970; lona, 1971; lona & bertoldi, 1972; bertoldi, caramiello & siniscalco in carraro ed., 1996) in the piacenzian and quaternary continental deposits outcropping in the arondelli, crotino and fornace rdb quarries and at several other sites where the sediments of the maretto unit are exposed. such data allow for the summarization and updating of the palynological documentation of both the lc and uc. lower complex the most-continuous palynological record is exposed in the rdb quarry (bertoldi in carraro ed., 1996), despite the fact that previous works here and in the other quarries produced rather discontinuous records due to the general scarcity of palynomorphs. bertoldi, however, by applying a pollen concentration method, was able to produce a rich palynological documentation, which now serves as reference due to the high quality of both the approach and the results. the resulting qualitative and quantitative data are used here to reconstruct the main floristic and vegetational changes and to propose inferences regarding the climate. the latter were developed by also taking into account palynological evidence from other pliocene and quaternary sites in northern and central italy (e.g., bertoldi & martinetto, 1995; bertini, 2010 and references therein). fifty samples from the san martino unit were collected by bertoldi along the reference section, which is 38 m thick and was exposed in the cava rdb in 1994 and 1995 (see fig. 29 in carraro ed., 1996). as shown by the original detailed and summary pollen diagrams (see figs. 50-53 in carraro ed., 1996), here redrawn and updated (fig. 20), palynomorphs are present only in the lower 18 m. in this portion, of 28 samples that were processed, 7 were barren of palynomorphs. in contrast, all 22 samples between 18 m and 38 m were either barren or contained few palynomorphs; the few palynomorphs were typically affected by degradation and/or corrosion, which sometimes prevented their identification. such behaviours are directly related to the depositional processes in the deltaic system (carraro ed., 1996). pedogenesis during the formation of hydromorphs hydromorphic (dark grey) or well-drained sols (dark brown), soils, ended when the water level rose and promoted lacustrine to palustrine conditions with the occasional accumulation of lignite, as indicated at 1.8 m and 17.7 m in the rdb section. in corresponding parts of the succession and in other organic-rich sediments, higher pollen counts (up to 13,000 arboreal pollen grains/gram) were observed. in contrast, the samples from the paleosols (e.g., between 26.6 m and 32.1 m) were generally barren or contained very few pollen grains due to the effects of major taphonomic biases. the rich pollen flora from the lower portion of the lc includes, as a whole, more than 100 pollen taxa, which have been attributed to 70 arboreal taxa and 30 non arboreal taxa. various pollen components (e.g. local and regional) 17 stratigraphic and tectonic notes on the villafranca d’asti succession ... fig. 17 a detail of the trench of fig. 13, with the thin succession of colluvium (2), involved in the formation of the paleosol, and the younger colluvium (3), not affected by the paleosol. were identified and described (bertoldi, in carraro ed., 1996). the local flora is especially abundant in hydrosols and in organicrich clays deposits. it includes plants thriving in wetlands areas, dominated by swamps as indicated by the predominace of arboreal taxa such as taxodium type, nyssa, myrica, carya p.p., pterocarya, ulmaceae (zelkova/planera, ulmus, …), parrotia, aesculus, platanus, alnus, salix, cf. populus, hygrophilous herbaceous taxa are represented by poaceae p.p., cyperaceae, ranunculaceae p.p., liliaceae, and some hydrophytes such as hydrocharitaceae, lemnaceae, sparganium type, thypha, myriophyllum, nymphaeaceae, potamogeton, alismataceae. the local pollen flora shows repeated fluctuations frequently opposed to those of pinus. for example, directly above 5 m in the section, the sharp decrease in subtropical to warm-temperate arboreal taxa accompanies a sudden and brief increase in hydrophytes initially and then of pinus plus pteridophyta. such change in pollen assemblages most likely reflects strong modifications in the local depositional environment, with over-representation phenomena of the local pollen plants. the pteridophyta curve shows successive fluctuations and higher abundances up to ca 7 m and then a decrease in the overlying interval up to ca 17 m; the hydrophytes exhibit a similar pattern. along with pteridophyta also bryophyta as well some fungi and algae are abundant. warmtemperate forest taxa in the dry sols of lowlands are principally represented by deciduous broad-leaf trees with minor evergreens: carya p.p. and other juglandaceae (e.g. engelhardia and juglans), the elements of quercetum (e.g. deciduous quercus, q. ilex type, tilia, acer, carpinus, corylus and ostrya), castanea, liquidambar, distylium, liriodendron, vitaceae (parthenocissus and vitis), eucommia, phellodendron, araliaceae, rare arecaceae, oleaceae (olea type, fraxinus ornus type, phillyrea), magnolia, celtis, ilex, rhamnus, celastraceae, rhus. pinus p.p., cedrus, tsuga, other cupressaceae (cfr. inaperturopollenites) and ephedra were also present. ericaceae, amaranthaceae, asteraceae asteroideae, caryophyllaceae, plantaginaceae, fabaceae, dipsacaceae, rosaceae p.p. were also distributed in this area; however such non arboreal plants do not exhibit significant expansions as indicated by their percentage values, which rarely exceed 20%. submontane to montane taxa are especially well represented by pinus p.p., picea, abies/keeteleria, fagus and betula. sequoia type and sciadopitys type were also present. pinus is present at very high percentages in places whereas all the other taxa are present at low percentages (fig. 20). the analysis of floral and vegetal assem 18 forno m.g. et al. fig. 18 stratigraphic sketch of the paleosol (p) and of the significant cumulative sequence of colluvial sediments (1, 2, 3, 4) observed at the top of silt (lc piacenzian), subsequently cut by the c. viarengo surface and covered by sand (uc calabrian). fig. 19 the nearly complete skeleton of stephanorhinus jeanvireti collected into the cascina san martino unit (piacenzian). cascina melona outcrop (roatto d’asti) in the central sector of the type-area. blages provides evidence of past climates and environmental changes, which also needs to be placed within a chronostratigraphic framework. the rdb pollen record (in carraro ed., 1996), after comparison with both the palynostratigraphic scheme traced for the continental upper neogene sections of northern italy and data from coeval marine sections (bertoldi, 1990, 1995; bertoldi et al., 1994), was assigned by bertoldi to the pre-tiberian phase (i.e. within the piacenzian). indeed, the absence/ presence and the abundance of peculiar taxa allowed bertoldi to conclude that the rdb pollen record postdates the macrian phase (due to the scarcity of tropical to subtropical taxa) and predates the tiberian (due to the still good occurrence of the taxodium type). palaeomagnetic (boano et al., 1999b) and biochronologic (e.g. rook and martinez-navarro, 2010 and references therein) evidence allows for an evaluation of whether the main (reverse to normal) magnetic polarity reversal at ca 13.5 m in the section of boano et al. (1999b) (which corresponds well to a portion of both sections described by carraro ed. [1996] in figs. 29 and 64) refers to the transition from 2ar to 2an.3n, from 2an.2r (mammoth) to 2an.2n or from 2an.1r (kaena) to 2an.1n. on the basis of our present knowledge, we can assert that: 1. palynological studies at rdb document the abundance of taxa typical of prevailing subtropical to warmtemperate climates, which is consistent with data from palaeobotanical macroremains (see below). 2. no major cold and/or dry phases, such as those associated with glaciations after 2.6 ma, are evident, assuming, with good approximation, that the section spans a time interval of at least 40 kyrs. 3. faunal data support an age for the magnetic polarity inversion (boano et al., 1999a) younger than that corresponding to the upper gilbert-lower gauss. such a hypothesis is not inconsistent with the pollen data and the interpretation proposed by bertoldi (in carraro ed., 1996). when we compare the succession of vegetal changes with those summarized in benthic oxygen isotopic curves (lisiecki & raymo, 2005), the most likely correlation is one with the time interval corresponding to the transition from 2an.1r to 2an.1n. however due to the absence of both a solid timediagnostic framework and a more extensive and continuous pollen record it is impossible to exclude other hypotheses especially that proposing the correlation with the time interval corresponding to the transition from 2an.2r (mammoth) to 2an.2n (martinetto et al., 2007; see also paragraph 7.2). 4. according to this last hypothesis pollen fluctuations (fig. 20) would correspond to m1-km5 and the first phase of km3 in the isotopic curve of lisiecki & 19 stratigraphic and tectonic notes on the villafranca d’asti succession ... fig. 20 summary pollen diagram of the rdb quarry (modified from bertoldi in carraro ed., 1996). from the left: benthic oxygen isotope stratigraphy (in the square modified from lisiecki & raymo, 2005), paleomagnetism (boano et al., 1999b) and lithologic column (modified from carraro ed., 1996) of the rdb. for stratigraphic correlation of the rdb with global events, see section 8.1. raymo (2005). nevertheless the succession of pollen phases does not show an evident correlation with those expressed by the isotopic curve, e.g. the pollen record does not exhibit a cooler phase such as the m2 as well as a major warm phase at its top correlatable with km5. 5. based on the alternative hypothesis (correspondence to the transition from 2an.1r to 2an.1n) rdb pollen record would span only the younger portion of the socalled mid-pliocene warm period (e.g. prescott et al., 2014 and references therein) (fig. 20). the lower portion of the pollen record may include (at least) k1 and g22 fluctuations (lisiecki & raymo, 2005). the short period, directly above 5 m in the rdb section, between the main two warm pollen phases is not clearly climatically marked because taphonomic biases (over-representation of hydrophytes) mask the true abundances of all the other taxa. a subsequent cooler phase (from approximately 8 m) is characterized by an increase of herbaceous taxa followed by the decline in subtropical to warm-temperate arboreal taxa; this change may correlate with the g22 fluctuation (lisiecki & raymo, 2005). the presence of numerous barren samples in the sand-dominated facies prevents a complete documentation of such a cooler phase. the pollen documentation is again available from ca 13.5 m (close to the magnetic polarity reversal). here, a slight increase in subtropical to warmtemperate taxa is recorded; this increase may correspond to the first warm phase across the base of the 2an.1n (g21). the cooler phase up to 17.7 m (g20) is followed at the top, close to 18 m, by a warm fluctuation. however, the latter is suddenly interrupted because of the sterility of the overlaying samples in the sand-dominated portion of the section (up to 38 m). in the rdb section, based on the succession of vegetal changes and their correlation to global events (e.g. lisiecki & raymo, 2005; prescott et al., 2014; fig. 20), once assumed the last hypothesis, the 18-m-thick pollen-rich succession (bertoldi in carraro ed., 2006) may span ca 100 kyr at the transition between 2an.1r (kaena) and 2an.1n (fig. 20). consequently, the overlying portion up to 38 m, despite the lack of a clear palynological documentation, may represent deposition beginning at ca 2.9 ma, i.e., during a progressive cooling preceding the instauration of glacial-interglacial cycles. this time interval is well documented by the pollen record from the upper valdarno intermontane basin (central italy), which shows the effects of climate on the flora and vegetation and the complex interactions between the climate and tectonics since 3.3 ma (bertini, 2010; 2013). in the asti area, an analogous interaction is clearly indicated by both the sedimentologic and structural records. upper complex the unfavourable lithologic features of the uc, which was affected by a strong weathering, have always discouraged palynological analyses since the first attempt by caramiello and siniscalco in carraro ed. (1996). nineteen samples were collected and analysed. of these, 3 were barren of palynomorphs. the 16 pollen spectra are representative of 16 sites for which a precise chronostratigraphic framework is absent. moreover, according to the information provided by previous authors, some of these were also affected by significant taphonomic biases most likely related to the mode of transport and deposition and to diagenetic effects. the collected data, although discontinuous, can be used to characterize the various lithostratigraphic units as part of the geologic mapping but not to reconstruct vegetational and climatic changes nor to develop detailed stratigraphic inferences. however, as a whole, it seems possible, on the basis of the comparison with the lc pollen assemblages and the integration with other evidence, that the uc was deposited primarily during the earlymiddle pleistocene. 7.2. macroflora the ferrere and san martino units yielded rich plant macrofossil assemblages (pavia, 1970; mai, 1995; martinetto & mai, 1996; martinetto, 2003), even if concentrated in a few sites and stratigraphic layers. following 20 forno m.g. et al. fig. 21 shoot of taxodium dubium from the san martino unit. the presentation of data by mai (1995), martinetto & mai (1996) and martinetto (2003) there have been new plant macrofossil findings in a single locality near castelnuovo don bosco; these had been merely cited by pavia et al. (2005). however, our knowledge of the italian plio-pleistocene macrofloral assemblages has represented consistent progress, in particular for the climatic and biochronological interpretation of the carpological component. on the other hand, the leaf assemblages are useful for palaeoenvironmental reconstruction, and thus all the plant macrofossil data are reexamined in this study, particulalyr in light of the results of martinetto et al. (2014). the available carpological assemblages originate from three sections of the san martino unit. the rdb section and castelnuovo don bosco sections also contain species-poor leaf assemblages, whereas the arboschio section provides rich leaf assemblages both in the ferrere unit and in the san martino unit. from a palaeoenvironmental point of view, the assemblages of the three sections and the assemblage from layer a4 of the san martino unit in the arboschio section can be attributed to swamp palaeocommunities that were often dominated by the bald cypress taxodium dubium (fig. 21). this is associated, in the rdb section, to fruits of alnus sp., boehmeria lituanica, proserpinaca reticulata, nyssa disseminata (fig. 22) and sassafras lusaticum (ciangherotti et al., 2007), thus indicating an ancient plant community similar to that of the cypress swamps of se north america, where taxodium and nyssa still grow together. another element of such swamp communities is a maple related to the modern acer rubrum. however, the fruit and seed assemblages also contained other elements which suggest a strong east asian affinity of the palaeoflora: actinidia, glyptostrobus, melissa, parrotia, paulownia, sinomenium, symplocos sect. lodhra (fritsch et al, 2008), toddalia, zelkova. the explanation for this twofold similarity is that the pliocene flora of southern europe conserved several elements of the ancient arctotertiary and palaeotropical (or tethyan) flora, which later went extinct in europe (apart from a few species) and partly survived only in se north america and/or east asia (mai, 1995; rodríguez-sánchez & arroyo, 2008). the areas where these species survived share a warm temperate cfa climate type (hot, wet summers), which can be included in a climate reconstruction of the ferrere and san martino units. in both the ferrere and san martino units, evergreen elements are present but scarce, such that a mixed mesophytic forest vegetation type is most likely for the reconstruction. the analysis of the biochronologically relevant taxa (martinetto et al., 2014) was applicable only to the carpological flora and indicated the absence of group 1 (typical of zanclean assemblages) and group 2 elements. the single exception is represented by a cast of an endocarp of symplocos schereri (group 2) found in the uppermost layer of the arboschio section, in the upper part of the san martino unit. aside from this exception, the assemblages of the san martino unit are characterized by good representation of group 3 elements. based on the lack of group 1 elements and the abundance of group 3 elements (ficus potentilloides, meliosma wetteraviensis, sinomenium cantalense, symplocos casparyi, toddalia naviculaeformis, toddalia rhenana, etc.), we conclude that the rdb1, rdb6 and rt1 assemblages are of a typical piacenzian composition. the comparative study of the palaeofloras from the san martino unit and other italian localities indicated that the interval between 3.2 to 2.6 ma provided 3 distinguishable palaeofloral types, which are dated to the time intervals of 3.2 to 3.0, 3.0 to 2.8 and 2.8 to 2.6 ma. the rdb1 and rdb6 assemblages provide information regarding the first interval (martinetto et al., 2007). the rt1 assemblage is significant with regard to the presence of the biochronologically relevant symplocos casparyi (martinetto et al., 2007). this section is not well calibrated chronologically due to the lack of magnetostratigraphic data. however, the lithostratigraphic correlation with the rdb section (boano & forno, 1996) indicates an age very close to that of rdb1 and suggests an assignment of the rt1 macroflora to the same time interval between 3.2 and 3.0 ma. 21 stratigraphic and tectonic notes on the villafranca d’asti succession ... fig. 22 fossil plants from layer rdb1 of the rdb section, san martino unit: endocarps of nyssa disseminata (top) and cones, cone scales and seeds of taxodium dubium (bottom). 8. deformation of sediments the villafranchian succession appears to be deformed by a gentle syncline with an ew axis. the lc is generally more deformed, as indicated by a syncline axis weakly plunging to the w. the uc appears to be less deformed, with a sub-horizontal syncline axis (see fig. 26). this context suggests a long time of deformation, partly after the lc sedimentation and partly after the uc deposition. the activity recorded by the two sedimentary complexes has a possible correlation with the gelasian phase, recognized in the po foreland basin (vigna et al., 2010). at the western edge of the type area and castelnuovo don bosco sector, there is an important structural discontinuity, the t. traversola deformation zone, which strikes n-s and dips nearly vertically (fig. 23). its morphological expression is a prominent n-s very long (30 km) and high (100 m on average) scarp that faces east and generally trends straight with local segmentation. this scarp divides a higher-on-the-west plain (poirino plateau) from a lower-on-the-east hilly region (asti reliefs) (fig. 2). new data regarding this structural element suggest a dextral strike-slip displacement, often marked by contrasting stratigraphic successions on the two sides (fig. 24 and fig. 25). there are other zones of vertical deformation in the castelnuovo don bosco region (c. fagliaverde fault zone and castelnuovo fault zone) and faults (gariglio fault, serra fault and agagliate fault) (fig. 23). these discontinuities are marked by the distribution of the villafranchian succession and the presence of sharp, subvertical contacts associated with the marine deposits and within the sequence itself. these structures indicate the presence of faults trending e-w and n10° e-n50°e with prevalent normal senses of offset (fig. 23). finally, the sediments display diffuse soft-sediment deformation in the form of small folds, slumps, sedimentary dikes, and de-structured laminae. this softsediment deformation appears to be linked to syndepositional and/or immediately post-depositional deformation of unconsolidated sediments. reworked sediments are also present locally in the form of heterogeneous mixtures of various sedimentary facies affected by numerous fractures and faults and covered by undeformed sediments. this evidence suggests local gravitative re-sedimentation of the succession along the main faults. 9. discussion and conclusion the revision of the type-area villafranchian succession and the study of castelnuovo don bosco section allowed for the identification of a regional erosional surface (the cascina viarengo surface and the cascina guerrina surface), which represents an unconformity in a sequence that was previously considered to be continuous (carraro ed., 1996; boano & forno, 1999). this unconformity separates the profusely fossiliferous deltaic lower complex (lc) from the generally barren fluvial upper complex (uc). the lc defines an e-w trending syncline with a 10-15° westward dip axis, whereas the uc is roughly sub-horizontal (fig. 26). the two complexes separated by the erosional surface can be differentiated based on the following contrasting features. structure: the sediments form a syncline with an e-w axis that dips to the west in the lc and horizontally in the uc. deformational features: the lc displays abundant softsediment deformation, such as folds, fractures, normal faults and reverse faults; the sediments of the uc are less deformed and display only folds, fractures and normal faults. 22 forno m.g. et al. fig. 23 the main faults and deformation zones involving the “villafranchian succession”. depositional environments: the lc is attributed to a deltaic depositional environment; the uc represents a fluvial environment. facies: the sediments of the lc are very heterogeneous and display very different facies and sedimentary structures; the sediments of the uc are, in contrast, very homogeneous and often lack sedimentary structures. fossils: the lc is highly fossiliferous,; the uc is sparsely fossiliferous and contains only minor pollen and vertebrate fossils. consolidation: the sediments of the lc are well consolidated due to loading by the uc, which is poorly consolidated and consequently soft. weathering: the lc is only locally weathered, in contrast to the uc, which is strongly weathered. terracing relationships: in the castelnuovo sector the uc is deeply entrenched into the lc, suggesting a strong deepening of the drainage network at the time of deposition. in the lc the magnetostratigraphic data (carraro ed., 1996; boano et al., 1999b) along with the numerous fossil remains, including fossil vertebrates (bones and teeth) and plant remains (pollen and macrofloral assemblages) all are consistent with a piacenzian age (see paragraphs 7 and 8). the ancient zonal vegetation was that of a mixed mesophytic forest both in the san martino and ferrere units, and the climate was warm temperate and humid, i.e., of the cfa type, with a mean annual temperature of 13-16 °c, a warmest monthly mean temperature of 23-25 °c, and a coldest monthly mean temperature of 1-3 °c (teodoridis et al., 2009). the chronological record of the uc is, instead, uncertain. this complex unconformably overlies the lc, thereby covering the cascina viarengo surface and indicating an age much later than the piacenzian. the significant differences between the lc and the uc indicate that a long time interval elapsed between the deposition of the two complexes, during which the environmental conditions drastically changed. the transition from deltaic sedimentation rich in fossil remains and the subsequent fluvial sedimentation, which is predominantly nonfossiliferous, required the passing of a long time-span. the uc is further covered by the fluvial sediments of the middle pleistocene (forno, 1982), in agreement with its previously reported age. the study of the rather discontinuous and scanty pollen record, which is however very different from that in the lc, suggests a possible early-middle pleistocene age (see paragraph 7.1). finally, a few elephant teeth preserved in the regional museum of natural science of turin (zuffardi, 1913) were not attributed to this complex with certainty but are likely also from the uc. this interpretation is based on the small amount of sediment attached to the fossils (compatible with the cascina gherba unit) and because these remains are inconsistent with the piacenzian association of the lc; an earlymiddle pleistocene age is suggested. according to the literature, the uc is further covered by middle-upper pleistocene sediments (forno, 1982), in agreement with a tentative assignment of the uc to the calabrian. the only fossil vertebrates in this complex are a fragment of cervid antler and a tooth fragment of sus 23 stratigraphic and tectonic notes on the villafranca d’asti succession ... fig. 24 a set of n-s faults (8) dislocate the sedimentary succession forming the t. traversola deformation zone. outcrop (dark color) and interpolating (light color) of lc (piacenzian) (1: ferrere unit; 2: san martino unit) and uc (calabrian) (4: cascina gherba unit; 5: maretto unit) separated by the cascina viarengo surface (3) and covered by the middle pleistocene (6) and holocene fluvial deposits (7). area of villata in the southern sector of the type area (c in fig. 3). fig. 25 a n-s fault (7) referred to the t. traversola deformation zone dislocates the sedimentary succession e of c. volpiano. outcrop (dark color) and interpolating (light color) of lc (piacenzian) (1: ferrere unit; 2: san martino unit), the uc (calabrian) (4: cascina gherba unit; 5: maretto unit) separated by the cascina viarengo surface (3). in the valley floors a cover of holocene fluvial deposits (6) occur. valmaggiore in the southern sector of the type area (d in fig. 3). sp., tentatively assigned to the early pleistocene, gelasian and/or calabrian age (see paragraph 6). regarding the hiatus corresponding to the erosional cascina viarengo surface, the possible reference to the calabrian for the uc is the most consistent. this evidence confirms the hiatus between the deposition of the two sedimentary complexes and emphasizes the long interval during which no deposition occurred. finally, the entire villafranchian succession was progressively involved in the syncline development and in the activity of deformational zones, particularly the ns t. traversola deformation zone on the western edge of the type area and of the castelnuovo don bosco sector (fig. 23). the study of the strike-slip activity of this structure, with a dextral strike-slip displacement, is well indicated by the dislocation of sediments. aknowledgment this research was conducted within the project “proactive management of geological heritage in the piemonte region”(www.progeopiemonte.it/en) cofounded by the university of turin compagnia di san paolo bank foundation “jcapc progetti di ateneo 2011” grant on line b1 "experimental sciences and technology" (project id: orto11y7hr). references ambrosetti p., azzaroli a., ficcarelli g., masini f., sala b., torre d. (1996) i vertebrati. in carraro f. (ed.) revisione del villafranchiano nell’area-tipo di villafranca d’asti. il quaternario, it. journ. quater. sci., 9(1), 70-73. amoretti c. (1808) su un dente e parte di mandibola d’un mastodonte trovati presso la rocchetta nel dipartimento del tanaro. mem. ist. naz. it., 1(2), 421-430. azzaroli a. (1977) the villafranchian stage in italy and the plio-pleistocene boundary. giornale di geologia, ser. 2, 41, 61-79. azzaroli a., vialli v. (1971) villafranchian. giorn. geol., 37(2) (1969), 221-232. baretti m. (1880a) resti fossili di rinoceronte nel territorio di dusino. (i comunicazione) atti r. acc. sc. torino, 15, 678-682. baretti m. (1880b) resti fossili di rinoceronte nel territorio di dusino. (ii comunicazione) atti r. acc. sc. torino, 15, 731-734. baretti m. (1880c) fotografie dello scavo e del montaggio del rinoceronte di dusino. dip. sci. terra, univ. torino, inedito. bertini a. (2010) pliocene to pleistocene palynoflora and vegetation in italy: state of the art. quatern. int., 225, 5-24. bertini a. (2013) climate and vegetation in the upper valdarno basin (central italy) as a response to northern hemisphere insolation forcing and regional tectonics in the late pliocene-early pleistocene. it. journ. geosci., 132, 137-148. bertoldi r. (1990) apporto della palinologia alla conoscenza dei giacimenti continentali pliocenici e pleistocenici inferiori dell’italia centro-settentrionale. st. trentini sc. nat., 66, 9-15. bertoldi r. (1995) palinostratigrafia dei bacini intermontani dell’appennino nord-occidentale. ii quaternario it. journ. quatern. sc., 8(1), 61-70. bertoldi r., binotti a., castello f. (1994) reevesia and itea in the pollen flora of the upper neogene continental deposit at sarzana (lower magra valley, northern italy). rev. palaeobot. palynol., 80, 159172. bertoldi r., martinetto e. (1995) ricerche paleobotaniche (palinologiche e paleocarpologiche) sulla successione “villafranchiana” del rio ca’ viettone (torino, italia). il quaternario it. journ. quatern. sc., 8(2), 403-422. bertoldi r., caramiello r., siniscalco c. (1996) i pollini. 24 forno m.g. et al. fig. 26 the lc dips to the west. a paleosol (p) at the top of lc (ferrere and san martino unit) is preserved in the western part of the type area, associated to colluvial deposits and fragmented fossil vertebrates, indicating the presence of an ancient stable topographic surface on which the weathering could develop and the fossil remains were accumulated. they were eroded along the c. viarengo surface and subsequently covered by the sub-horizontal uc. the “villafranchian succession” was progressively involved in the activity of the n-s t. traversola deformation zone at the western edge of the study area. in: carraro f. (ed.) revisione del villafranchiano nell'area-tipo di villafranca d'asti. atti del convegno: "il significato del villafranchiano nella stratigrafia del plio-pleistocene" (peveragno (cn)villafranca d'asti (at), 20-24 giugno 1994). il quaternario it. journ. quatern. sc., 9 (1), 79-90. berzi a., michaux j., hutchison j.h., lindsay e (1970) the arondelli local fauna, an assemblage of small vertebrates from the villafranchian stage near villafranchian d’asti, italy. giorn. geol., ser.2, 35(1) (1967), 133-136. boano p., forno m.g. (1996) carta geologica del villafranchiano dell'area-tipo, alla scala 1 : 20.000. in: carraro f. (ed.) revisione del villafranchiano nell'area-tipo di villafranca d'asti. atti del convegno: "il significato del villafranchiano nella stratigrafia del plio-pleistocene" (peveragno (cn)villafranca d'asti (at), 20-24 giugno 1994). il quaternario it. journ. quatern. sc., 9 (1), 34-36. boano p., forno m.g., giardino m. (1997) deformazioni sinsedimentarie nella successione villafranchiana presso castelnuovo don bosco (asti). il quaternario it. journ. quatern. sc., 10(2), 355-358. boano p., forno m.g. (1999) la successione “villafranchiana” nell’area di castelnuovo don bosco (asti). il quaternario it. journ. quatern. sc., 12 (2), 161-194. boano p., boero w., forno m. g., mottura a. (1999a) significato di concentrazioni di resti fossili associati a un suolo e a prodotti colluviali entro la successione-tipo villafranchiana. geoitalia, 2° forum italiano di scienze della terra della fist (bellaria, 20 -23 settembre 1999), riassunti, 1, 203-206. boano p., bormioli d., carraro f., lanza r. (1999b) magnetic stratigraphy of the villafranchian typesection (villafranca d'asti, italy). ann. geoph. 42, 9 -19. boni a., boni p., braga g., bruno g., casnedi r., corsi m., gatto g.o., gatto p., mosna s., motta e., perotto g., rampoldi r. (1969) foglio 69 “asti”. carta geologica d’italia alla scala 1:100.000, ii ed., serv. geol. it., roma. borson e. (1820) mémoire sur des machoires et des dents du mastodonte dit mammuth, trouvés fossiles en piémont. mem. r. acc. sc. torino, 24, 160176. borson e. (1823) note sur des dents du grand mastodonte trouvées en piémont et sur des machoires et dents fossiles prises dans la mine de houille de cadibona proche savone. mem. r. acc. sc. torino, 27, 31-42. borson e. (1830) catalogue raisonné du musée d’historie naturelle de l’académie de turin. imprimérie royale, torino, pp. 740. campanino f., forno m.g., mottura a., ormezzano d., sala b. (1994) stephanorhinus jeanvireti (guérin, 1972) (rinocerotidae, mammalia) from roatto near villafranca d'asti, nw italy revision of the specimen from dusino. boll. museo reg. sc. nat. torino, 12, 439-499. carraro f. (ed.)(1996) revisione del villafranchiano nell'area-tipo di villafranca d'asti. atti del convegno: "il significato del villafranchiano nella stratigrafia del plio-pleistocene" (peveragno (cn)villafranca d'asti (at), 20-24 giugno 1994). il quaternario it. journ. quatern. sc., 9(1), 38-62. carraro f., forno m.g., valpreda e. (1982) field trip in northern italy. guidebook. september 15th. piedmont: asti area. i.g.c.p. 73/1/24 pr. quaternary glaciations in the northern hemisphere. final session. september 1/17th 1982. france-italy. litografia massaza & sinchetto, pp. 24. ciangherotti a., esu d., martinetto e., giuntelli p. (2007) the remarkable middle pliocene non-marine mollusc record from ceresole d'alba, piedmont, northwest italy: biochronology, palaebiogeography and palaeoecology supported by fossil plants. geobios 40, 573-587. cuvier g. (1806) sur differentes dents du genre des mastodontes. ann. mus. hist. nat. paris, 8, 401424. dela pierre f., piana f., fioraso g., boano p., bicchi e., forno m. g., violanti d., clari p., polino r., balestro g., d’atri a. (2003) foglio 157 “trino” della carta geologica d’italia alla scala 1: 50.000. apat, dipartimento difesa del suolo, roma. fejfar o., heinrich w.d. (1990) muroid rodent biochronology of the neogene and quaternary in europe. in: lindsay e.h., fahlbusch v., mein p. (eds). european neogene mammal chronology”. plenium press, new york. festa a., boano p., irace a., lucchesi s., forno m.g., dela pierre f., fioraso g., piana f. (2009) foglio 156 “torino est” della carta geologica d'italia alla scala 1:50.000. ispra-servizio geologico d’italia, roma. francavilla f., bertolani marchetti d., tomadin l. (1969) nouvelles données sur le villafranchien-type. vii congrés inqua, paris 1969, “etude sur le quaternaire dans le monde”, 575-585. francavilla f., bertolani marchetti d., tomadin l. (1970) ricerche stratigrafiche, sedimentologiche e palinologiche sul villafranchiano tipo. giorn. geol., ser. 2, 36(1968), 701-741. francavilla f., tomadin l. (1970) contributo alle conoscenze paleobotaniche e sedimentologiche nel villafranchiano tipo. giorn. geol., ser. 2,35(1) (1967), 65-76. fritsch p.w., kelly l.m., wang y.f., almeda f., kriebel r. (2008) revised infrafamilial classification of symplocaceae based on phylogenetic data from dna sequences and morphology. taxon 57, 823852. gabert p. (1962) les plaines du po et leurs piedmonts (piemont, lombardie occidentale et centrale). etude morphologique. pp. 531. luis jean, gap. gastaldi b. (1860) su alcune ossa di mammiferi fossili del piemonte. atti soc. it. sc. nat., 2, 213-216. gastaldi b. (1861) cenni sui vertebrati fossili del piemonte. mem. r. acc. sc. torino, ser. 2, 19, 19-89. gentili s., mottura a., rook l. (1998) the italian fossil primate record: recent finds and their geological contest. geobios, 31(5), 675-686. ghielmi m., minervini m., nini c., rogledi s., rossi m. (2010) sedimentary and tectonic evolution in the eastern po plain and northern adriatic sea area 25 stratigraphic and tectonic notes on the villafranca d’asti succession ... from messinian to middle pleistocene (italy). in: sassi, f.p. (ed.). nature and geodynamics of the lithostere in northern adriatic. rend. lincei sc. fis. nat. 21 (suppl. 1), 131-166. ghielmi m., minervini m., nini c., rogledi s., rossi m. (2013) late miocene-middle pleistocene sequences in the po plain-northern adriatic sea (italy): the stratigraphic record of modification phases affecting a complex foreland basin. mar. petrol. geol. 42, 50-81. gibbard p.l., head m.j., walker m.j.c. (2010) formal ratification of the quaternary system/period and the pleistocene series/epoch with a base at 2.58 ma. j. quat. sci. 25, 96-102. gignoux m. (1916) l’etage calabrien (pliocène supérieur marin) sur le versant ne dell’appennin, entre le monte gargano et plaisance. boll. soc. géol. de france 4, 324-348 gliozzi e., abbazzi l., argenti p., azzaroli a., caloi l., capasso barbato l., di stefano g., esu d., ficcarelli g., girotti o., kotsakis t., masini f., mazza p., mezzabotta c., palombo m.r., petronio c., rook l., sala b., sardella r., zanalda e., torre d. (1997) biochronology of selected mammals, molluscs and ostracods from the middle pliocene to the late pleistocene in italy. the state of the art. riv. it. paleont. stratigr., 103(3), 369-388. hurzeler j. (1967) nouvelles découvertes de mammifères dans les sediments fluvio-lacustres de villafranca d’asti. colloques intern. c.n.r.s., 163 “problèms actuels de paléontologie (évolution des vertébrés)”, paris, 6-11 juin 1966, 633-636. irace a., clemente p., piana f., de luca d.a., polino r., violanti d., mosca p., trenkwalder s., natalicchio m., ossella l., governa m., petricig m. (2010) hydrostratigraphy of the late messinianquaternary basins in the southern piedmont (northwestern italy). mem. descr. carta geologica it., 90, 133-152. irace a., monegato g., tema e., martinetto e., pini r., gianolla d., bellino l.( 2012) the pliocenepleistocene transition in southern piedmont: new data from the alessandria basin. inqua-seqs 2012, sassari ( italy), 41-42. lindsay e.h., opdyke n.d., fejfar o. (1997) correlation of selected late cenozoic european mammal faunas with the magnetic polarity time scale. palaeogeography, palaeoclimatology, palaeoecology, 133, 205-226. lindsay e. h., opdyke n. d., johnson n.m. (1980) pliocene dispersal of the horse-equus and late cenozoic mammalian dispersal events. nature 287, 135-138. lisiecki l.e., raymo m.e. (2005) a pliocenepleistocene stack of 57 globally distributed benthic delta o-18 records. paleoceanography, 20, pa. 1003. lona f. (1971) correlazioni tra alcune sequenze micropaleobotaniche plio-pleistoceniche continentali e marine dell’italia centro-settentrionale ed europa centro occidentale con riferimento al limite tiberiano. l’ateneo parmense acta naturalia, 6, 145157. lona f., bertoldi r. (1972) la storia del pliopleistocene italiano in alcune sequenze vegetazionali lacustri e marine. atti acc. naz. lincei, 11, 145. mai d.h. (1995) paleocarpological investigations in the villafranchian (pliocene) of italy. boll. mus. reg. sci. nat. torino 13, 407-437. martinetto e. (2003) leaves of terrestrial plants from the shallow marine and transitional pliocene deposits of asti (piedmont, nw italy). boll. soc. paleont. it., 42 (1-2), 75-11. martinetto e., mai d.h. (1996) macrofossili vegetali. in: carraro f. (ed.), revisione del villafranchiano nell'area-tipo di villafranca d'asti. il quaternario 9 (1), 73-79. martinetto e., monegato g., irace a., vaiani s.c., vassio e. ( 2014) pliocene and early pleistocene carpological records of terrestrial plants from the southern border of the po plain (northern italy). review of palaeobotany and palynology, 1-19. doi: 10.1016/j. revpalbo.2014.10.007. martinetto e., scardia g., varrone d. (2007) magnetobiostratigraphy of the stura di lanzo fossil forest succession (piedmont, italy). riv. ital. paleont. strat., 113(1), 109-125. martinis b. (1949) introduzione allo studio del villafranchiano nella valle padana. riv. it. pal. stratigr., 55 (2), 45-72. masini f., rook l., abbazzi l., ambrosetti p., azzaroli a., ficcarelli g., gentili s., kotsakis t., sala b., torre d. (1996) mammalian faunas of selected villafranchian localities of italy. in carraro f. (ed.) revisione del villafranchiano nell’area-tipo di villafranca d’asti. tav. 2, il quaternario, it. journ. quatern. sci, 9(1). mosca p., polino r., rogledi e., rossi m. (2009) new data for the kinematic interpretation of the alpsapennines junction (northwestern italy). int j earth sci (geol rundsch) 99, 833-849. mottura a., ardito g. (1992) observations on the turin specimen of mesopithecus pentelici (wagner, 1839). human evolution, 7(1), 67-73. pareto m. (1865) note sur la subdivision que l’on pourrait établir dans les terrains de l’apennin septentrional. bull. soc. géol. fr., ser. 2, 22, 210-277. pavia g. (1970) resti di anancus arvernensis e flora ad affinità pliocenica nel villafranchiano inferiore della cava di arboschio. mem. soc. geol. it. 9, 157 -176. pavia g., bortolami g., damarco p. (eds.) (2005) censimento dei geositi nel settore regionale collina di torino e monferrato. quaderni scientifici piemonte parchi, 5, pp. 146. petrucci f., tagliavini s. (1968) considerazioni geomorfologiche sul settore occidentale del bacino fluvio lacustre del villafranchiano di villafranca d’asti. quat. cont. padano (2), ateneo parmense, acta naturalia, 4 (2), 1-32. piana f., polino r. (1995) tertiary structural relationships between alps and apennines: the critical torino hill and monferrato area, northwestern italy. terra nova, 7, 138-143. pieri m., groppi g. (1981) subsurface geological struc 26 forno m.g. et al. ture of the po plain, italy. cnr, quad. prog. fin. geodinamica, roma, 1-13. prescott c.l., haywood a. m., dolan a.m., hunter s.j. pope j.o, pickering s.j. (2014) assessing orbitally-forced interglacial climate variability during the mid-pliocene warm period. earth planet. sci. lett. 400, 261-271. rodríguez-sánchez f., arroyo j. (2008) reconstructing the demise of tethyan plants: climate-driven range dynamics of laurus since the pliocene. global ecol. biogeogr. 17, 685-695. rook l., martínez-navarro b. (2010) villafranchian: the long story of a plio-pleistocene european large mammal biochronologic unit. quaternary international, 219, 134-144. sacco f. (1884) nuove specie fossili di molluschi lacustri e terrestri in piemonte. atti r. acc. sc. torino, ser. 2, 19, 247-264. sacco f. (1886a) fauna malacologia delle alluvioni plioceniche del piemonte. mem. r. acc. sc. torino, ser. 2, 37, 169-206. sacco f. (1886b) nuove specie terziarie di molluschi terrestri, d’acqua dolce e salmastra del piemonte. atti soc. it. sc. nat., 29, 427-476. sacco f. (1886c) le fossanien nouvel étage du pliocène d’italie. bull. soc. géol. france, sér. 3, 15, 27-36. sacco f. (1890) il bacino terziario e quaternario del piemonte. tip. bernardoni, milano, pp. 643. sacco f. (1895 ) le rhinocéros de dusino (rhinoceros struscus falc. var. astensis sacc.). arch. mus. hist. nat. lyon, 6, 1-31. sacco f. (1922) f. 69, “asti”, della carta geologica d’italia alla scala 1:100.000. i ed., r. uff. geol., roma. selli r. (1967) the pliocene pleistocene boundary in italian marine sections and its relationship to continental stratigraphies. progress in oceanography, 4, 67-86. savage d.e., russell d.e. ( 1983) mammalian paleofaunas of the world. addison-wesley publishing company, london, pp. 432. sismonda e. (1849) lettera a michelin del 23 ottobre 1849 (con annuncio del ritrovamento di scheletro di mastodonte negli scavi della ferrovia). bull. soc. géol. france, 2(7), pp. 49. sismonda e. (1852) osteografia di un mastodonte angustidente. mem. r. acc. sc, torino, ser. 2, 12, 175-239. teodoridis v., kvaček z., uhl d. (2009) late neogene palaeoenvironment and correlation of the sessenheim-auenheim floral complex. palaeodiversity, 2, 1-17. vigna b., fiorucci a., ghielmi m. (2010) relations between stratigraphy, groundwater flow and hydrogeochemistry in poirino plateau and roero areas of the tertiary piedmont basin, italy, mem. descritt. carta geol. it., 90, 267-292. zuffardi p. (1913) elefanti fossili del piemonte. paleontogr. it., 19, 121-187. 27 stratigraphic and tectonic notes on the villafranca d’asti succession ... ms. received: december 29, 2014 final text received: february 10, 2015 28 amq_28(1) coloph 3.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 28 (1), 2015, xi xiii report on the inqua 6th international workshop “active tectonics, paleoseismology and archaeoseismology” fucino 2015. april 19-24, 2015, pescina (aq) stefano gori, emanuela falcucci, fabrizio galadini istituto nazionale di geofisica e vulcanologia, l’aquila, italy corresponding author: s. gori <stefano.gori@ingv.it > abstract: the inqua 6th international workshop on active tectonics, paleoseismology and archaeoseismology, held in pescina (l’aquila, italy) on april 19-24, 2015, pointed out the recent scientific outcomes derived from both classical and new methodological approaches and techniques, and included a two-day field trip in the epicentral areas of the 1915 fucino earthquake and of the april 6, 2009, l’aquila earthquake. keywords: paleoseismology, active tectonics, inqua workshop, fucino 2015, italy one hundred years after the great marsica earthquake (estimated magnitude 7), that hardly struck central italy on the 13th of january, 1915, the international union for quaternary science (inqua) sponsored the 6th international workshop on active tectonics, paleoseismology and archaeoseismology. the workshop was organised by istituto nazionale di geofisica e vulcanologia (ingv), istituto superiore per la protezione e la ricerca ambientale (ispra) and università dell’insubria, to foster discussion, and to share the most recent achievements, between different disciplines in the field of the earthquake geology. such an important scientific appointment was held between april 19 and 24, 2015, in the town of pescina, which is located in the epicentral area of the 1915 earthquake. the town was the ideal stage to commemorate the tragic event, as the earthquake traces can still be distinguished on the remnants of the walls of the old town centre that, together with many villages and towns around the fucino plain area, stand as open air memorials in honour of the more than 30000 fatalities. the workshop gathered together more than two hundreds researchers from all continents, who daily spend their efforts in the earthquake science, with the aim of obtaining up-to-date information to be incorporated in seismic hazard analyses and to be used for mitigating seismic risk. the participants attended to a three-day scientific discussion on quaternary geology, paleoseismology, earthquake engineering, seismic hazard, tsunami hazfig. 1 northern wall of the trench dug across the 1915 earthquake surface rupture. main fault plane, red arrow ard and archaeoseismology, followed by a two-day fieldtrip in the epicentral areas of the 1915 earthquake and of the 6th of april, 2009 l’aquila earthquake (moment magnitude 6.1). the most recent scientific outcomes derived from different methods and techniques – i.e., from the classical geological field investigations to the cosmogenic nuclides dating of exposed fault planes – were illustrated by a large number of oral and poster presentations. the first day of field trip was spent along the fucino plain area, specifically along the trace of the active normal fault that ruptured during the 1915 earthquake, known and the fucino fault. firstly, a paleoseismological trench dug ad hoc for the meeting purpose across the surface rupture reported by oddone – the seismologist that surveyed the fucino area in the aftermath of the event – was visited (fig. 1). in general, paleoseismological trenching aims at unveiling the kinematic history of a given active tectonic structure, by defining how often it moves, the elapsed time since the last activation, and how strong can be an earthquake determined by the fault activation. at this purpose, one or more excavations are made across the surface expression of an active fault in order to uncover recent sediments that might have undergone deformation induced by the fault motions. the trench visited during the workshop, and illustrated by paolo galli (dpcn), aimed at showing the participants the geological traces of the surface faulting occurred during the 1915 seismic event, and of previous episodes of fault activation. in particular, the analysis of the trench walls allowed the identification of the faulting event occurred during the late antiquity, in 508 (or 484) ad; this event resulted in a large magnitude earthquake – comparable to the 1915 one – that determined heavy damages to the ancient settlements surrounding the fucino area, being also likely responsible for significant damages to colosseum in rome. secondly, a quarry (known as cava santilli) located close to venere dei marsi was visited during the fieldtrip; it exposed one of the planes of the fucino fault that brought the carbonate bedrock (footwall) into contact with late holocene slope-derived deposits (hanging wall) (fig. 2). the scarplet related to the northernmost segment of the fucino fault, affecting the south-western slopes of the magnola mts., was also shown and the evidence of both the long-term and recent activity of the structure, represented by the displacement of slope deposits spanning the whole quaternary, was illustrated. paolo messina (cnr-igag) described the quaternary stratigraphic sequence hosted by the fucino basin, in particular the succession exposed near pescina. finally, the remnants of the 1915 earthquake coseismic scarp were also visited and described by alessandro m. michetti (università dell’insubria); furthermore, gerald roberts (birkbeck university of london, uk) described the holocene exposition history of the mt. serrone fault scarp, related to one of the segments of the fucino fault. the second day of the field trip was devoted to the l’aquila-san demetrio ne’ vestini basin area, the epicentral zone of the 2009 earthquake. during the first part of the fieldtrip, the scarp related to the san demetrio active normal fault was shown by anna maria blumetti (ispra) and the results of paleoseismological analyses made along the fault were discussed. then, the early quaternary continental stratigraphic sequence hosted by the l’aquila-san demetrio ne’ vestini depression was depicted by stefano pucci (ingv), fabio villani (ingv) and colleagues (fig. 3), particularly the paleo-deltaic succession exposed by a quarry in the area of poggio xii ciaranfi n. fig. 2 wall of the “cava santilli” quarry showing the fucino fault plane (yellow arrows) that places in contact holocene slope deposits, in the hanging wall (on the left), with the carbonate bedrock, in the footwall (on the right). picenze. then, a normal fault active during the early stages of formation of the depression was shown along the fosso dell’inferno fluvial incision. at the end of the field trip the city of l’aquila was visited. laura graziani (ingv) and filippo bernardini (ingv) illustrated the seismic history and provided the macroseismic description of the city. sara amoroso (ingv), francesco potenza (università dell’aquila) and giacomo tironi (freelance engineer) showed the participants the damages induced by the 2009 seismic event and described the current restoration activities. xiii lower-middle pleistocene in italy fig. 3 s. pucci and his ingv colleagues illustrate the stratigraphic framework of the l’aquila-san demetrio ne’ vestini basin. ms. received: may 12, 2015 final text received: april 18, 2015 amq32(2) 101-115 salari et al.pub reassessing the faunal assemblages of the late pleistocene stratified karst filling from avetrana (apulia, southern italy): the bed 8, palaeoenvironment and biochronology leonardo salari 1, carmelo petronio 1, tassos kotsakis 2, giuseppe di stefano 1, francesco grossi 2, leonardo maiorino 2, luca pandolfi 2,3, mario federico rolfo 4, francesca daniela ruiu 5, gabriele sansalone 2,6, antonio tagliacozzo 5  1 dipartimento di scienze della terra, “sapienza” università di roma, roma, italy. 2 dipartimento di scienze, università di “roma tre”, roma, italy. 3 dipartimento di scienze della terra, università degli studi di firenze, firenze, italy. 4 dipartimento di storia, patrimonio culturale, formazione e società, università degli studi di roma “tor vergata”, roma, italy. 5 sezione di bioarcheologia, museo delle civiltà, roma, italy. 6 evolution and anatomy research laboratory, zoology, school of envi. and rural sciences, univ. new england, armidale, australia. corresponding author: l. salari <leonardosalari@virgilio.it> abstract: the late quaternary vertebrate deposit of the stratified karst filling from avetrana (apulia, italy) was the subject of an intensive excavation campaign in 2003, followed by numerous subsequent investigations and collections of fossil remains. in this work, the biochronological implications and the palaeoenvironmental reconstruction of the area in the late pleistocene are updated and improved based on the more recent observations (2012-2013). in particular, the faunal assemblage found in the uppermost stratum (bed 8) of the fossiliferous deposit is analysed where the proportion of wolf remains increases sharply against the underlying layers. a synthesis and a recapitulation of the vertebrate assemblages recovered in the entire stratified karst filling are also given. new observations on the preservation of the bone remains and population analyses of representative mammal species (canis lupus, bos primigenius, cervus elaphus, dama dama and sus scrofa) show that bed 8 displays features indicating its origination in sedimentary, climatic and environmental conditions quite different from those of underlying beds. up to bed 7, the stratified karst filling and its faunal assemblages were generated by a succession of catastrophic mass mortality events in a very short time alternated with moments of quiet deposition, during the early late pleistocene (mis 5e). instead, bed 8 deposited over a longer time span, probably to be placed between the beginning of last glacial period and early mis 3, when a puddle of water or a pond was likely at the top of the residual cavity filling. lithic artefacts recovered in bed 8 and in bed 6 only testifies the attendance of neanderthal humans in the surrounding of avetrana. keywords: late pleistocene, southern italy, population analysis, palaeoenvironment, biochronology. available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 32 (2), 2019, 101 115 1. introduction the vertebrate assemblage found out near avetrana (taranto, apulia, southern italy; fig. 1a), in an abandoned quarry at la grave locality, has been the subject of an intensive campaign of excavations carried out by researchers of “sapienza” university of rome, in agreement with the “soprintendenza archeologia, belle arti e paesaggio” of apulia, in october 2003, followed by numerous subsequent investigations and collections of fossil remains (sardella et al., 2005; petronio et al., 2008; salari & sardella, 2009; pandolfi et al., 2011, 2013a; bertè & pandolfi, 2014; kotsakis et al., in press). apulia is well known for the presence of karst cavities containing palaeontological and archaeological deposits with rich bone assemblages of late pleistocene. therefore, this region represents an important repository of data for reconstructing the evolution of past environments during the recent quaternary in southern europe (petronio et al., 2007; pandolfi et al., 2017a). abundant faunal remains have been recovered in different karstic cavities of apulia, mainly in cave deposits in which the main accumulation agents were the middle and upper palaeolithic humans (palma di cesnola, 2001; mussi, 2002). only in a few sites, such as ingarano in the gargano peninsula (petronio et al., 1996), in the so-called "ventarole" of salento peninsula (de giuli, 1983; bologna et al., 1994; rustioni et al., 1994; pandolfi et al., 2017a) and at avetrana on the ionic side of the region, the vertebrate bone remains can be considered of natural supply. these sites are represented by sub-vertical or funnel-shaped cavities within limestone formations, sinkholes filled mainly with residual clays of karst activity, other sediments and pebbles. they have presumably functioned as traps for living fauna in the environs and/or as reservoirs for waters that https://doi.org/10.26382/amq.2019.07 102 salari l. et al. transported what they found (sediments, pebbles, bones) in the surrounding areas (de giuli, 1983; bologna et al., 1994; rustioni et al., 1994; petronio et al., 2008; pandolfi et al., 2013a, 2017a). in these karst cavities, the vertebrate remains are generally in a good state of preservation and are commonly located at the base and/or at the top of these karstic infills, without signs of long-distance transport (bologna et al., 1994; petronio et al., 2008; pandolfi et al., 2013a, 2017a). in addition, remains are chaotically scattered and lacking specific taphonomic signatures or traces of human activity, and sometimes parts of the same skeletal element occur at different depths (de giuli, 1983; bologna et al., 1994). these karst infills were probably accumulated rapidly and each bone assemblage within them usually appear as coeval in age (bologna et al., 1994; but see pandolfi et al., 2017a). among these karst fillings, only the deposit of avetrana show a stratigraphic succession. as described by sardella et al. (2005) and petronio et al. (2008), the late pleistocene fossiliferous deposit from avetrana is found in an open-air sub-vertical karst cavity within early pleistocene limestone (“calcareniti di gravina” formation). very abundant remains of large and small mammals, birds, other vertebrates and fine sediments with sparse calcareous pebbles constitute the cavity infilling. according to petronio et al. (2008) several layers, or beds, recognized in the site of avetrana (fig. 1b), probably deposited rapidly during a short time span (from a geological point of view) by exceptional events, resulting in the rapid incorporation of carcasses and isolated vertebrate remains in the karst cavity. the abundance of the remains, many still in articulation, their state of preservation, the rarity of skulls and the population analysis of some representative mammal species strongly have suggested to pandolfi et al. (2013a) that a significant part of the bone remains were accumulated by water during several catastrophic events in the area. in particular, beds 2, 5 and 7, which contain abundant fossil remains and sparse clay-sandy matrix, were deposited over a very short time and probably each represent a single depositional event; in contrast, beds 1, 3, 4, 6 and 8, which are characterized by abundant clay-sandy matrix and sparse fossil remains, have been probably deposited by water and gravity over a longer time span. the population analyses of the taxa recovered from the site supports the hypothesis of rapid infilling of the cavity through heavy rainfall and flash floods. in particular, aurochs, fallow deer and red deer have provided useful information about the season of death and consequently the probable time span of the aggradations. in beds 5 and 7, the estimated season of death of these three species, particularly for the young animals, has suggested probable catastrophic depositions between the autumn and the winter (pandolfi et al., 2013a). so far, the entire mammal assemblage was referred to the early late pleistocene (sardella et al., 2005) and related to melpignano faunal unit (petronio et al., 2008). later, pandolfi et al. (2013a) tentatively restricted the time interval to marine isotope stage 5e (=mis 5e). nevertheless, with respect to the others, the eighth and uppermost bed shows some peculiar features. in this bed, the percentage of damaged and concreted bones is relatively high, compared to underlying beds. furthermore, in bed 8 there is a very high percentage of carnivore remains, in particular wolf (pandolfi et al., 2013a; bertè & pandolfi, 2014; mecozzi & bartolini lucenti, 2018). pandolfi et al. (2013a) have underlined these particularities of bed 8, but not adequately investigated. fig. 1 avetrana (southern italy), late pleistocene: a) location of the site; b) stratigraphy of the karst filling in la grave locality (by petronio et al., 2008, redrawn). 103 late pleistocene faunal assemblages from avetrana (italy) during the 2012 and 2013 surveys at the site of avetrana, new fossil remains were collected and important new stratigraphic observations, particularly related to the small vertebrates found in all layers (kotsakis et al., in press) and to the faunal assemblage of bed 8 and a lithic artefact found in this bed, were made. the aim of this additional work on the stratified fossiliferous deposit of avetrana is therefore to analyse the faunal assemblage found in bed 8, comparing it with the faunal assemblages of the underlying layers, in order to update and improve the biochronological implications and the palaeoenvironmental reconstruction of the area in the late pleistocene.  2. stratigraphic notes sardella et al. (2005) and petronio et al. (2008) recognized several levels in the depositional sequence of avetrana karst filling (fig. 1b). the deposit was divided into nine beds in the main sub-vertical karst cavity (about 4.5 m thick) and two discrete basal infillings, or pockets, that are described below, from the bottom to the top, according to the previous works (sardella et al., 2005; petronio et al., 2008; pandolfi et al., 2013a; kotsakis et al., in press) and the recent observations. at the bottom of the sequence, there are two small and irregular fissures, named bed 0, which are filled by orange-yellow non-laminated sandy clays rich in small fossil vertebrate remains (tab.1), probably because it was the only material that could pass through the small karstic fissures. bed 1 is composed of an uninterrupted stratum of calcareous pebbles, overlain by a thin deposit (30 cm) of argillaceous sand containing rare and altered clayey pebbles and a few fossil bones. bed 2 comprises a thin (20 cm) deposit of sandy clay including numerous bone remains. bed 3 consists of 20 cm of argillaceous sand with only a few bones. bed 4, equally around 20 cm thick, is separated from the underlying layer by a discontinuity, marked by a stratum containing calcareous pebbles, and it is formed by clayey sands including fragmentary remains. bed 5, around 140 cm thick, contain rare calcareous pebbles at the bottom followed upwards by thousands of bones, especially of b. primigenius, and scarce argillaceous sand matrix. the following bed 6 is formed by about 20 cm of argillaceous sandy matrix and yielded several mammal remains. a single mousterian lithic artefact was discovered in this layer. in bed 7, around 40 cm thick, the abundance of fossil remains and the scarcity of sandy clay matrix are similar to that in bed 5, but the remains of small vertebrates are practically absent. bed 8 is formed by about 75 cm of sandy clays sediments with calcareous pebbles and scattered remains of large and small vertebrates. a single lithic artefact was also discovered in this bed. the covering deposit (bed 9 in fig. 1b) is a clayey soil about 70 cm thick with very rare and decalcified bones. 3. materials and methods the fossils found out at locality la grave near avetrana in the intensive campaign of excavations carried out in october 2003 are housed at the “soprintendenza archeologia, belle arti e paesaggio” of apulia in taranto. the fossil remains collected in the subsequent survey campaigns are temporarily stored in the earth sciences department of “sapienza” university of rome (large mammals), in the section of bioarchaeology of the civilizations museum of rome (birds), and in the sciences department of "roma tre" university (small vertebrates), pending the decision of tab. 1 avetrana (southern italy), late pleistocene: faunal lists reporting all the vertebrate taxa recovered in each bed. “soprintendenza archeologia, belle arti e paesaggio” of apulia for the final ubication. in 2012-2013 field surveys, hand collection of the fossil remains of medium and large mammals (particularly from bed 8) was carried out. during the 2013 was also made a sampling in all the layers in search of small vertebrates, sifting several kg of sediments. the vertebrate remains were compared with osteological material, both fossil and recent, stored in the earth sciences department of the “sapienza” university of rome, in the section of bioarchaeology of the civilizations museum of rome and in the sciences department of the “roma tre” university. the methodologies of study of medium and large mammals are the same as in pandolfi et al. (2013a). together, the most recent and previous stratigraphic observations of the karst filling described above, taking into account the position and orientation of the bones in the bed 8, their preservation state (concreted, very or little damaged, well preserved; concreted bones were counted only once, regardless if they were well preserved or damaged) and the possible modifications to the bone surfaces, represent the first stage in reconstructing the depositional events. furthermore, population analyses of some representative species may be used to obtain possible information about the time span of depositional events, the seasonality of such events and biochronological and palaeoenvironmental indications. the above, was compared to the preservation status of the bone remains and the population analyses of the underlying beds. for this purpose, the fossil remains were quantified both in number of identified specimens (=nisp) and in the minimum number of individuals (=mni). the mni was calculated taking into consideration the side of each bone (right or left) and the most frequent skeletal element from only one side. the results were integrated with the analysis of the metrical characters, sex and age profiles of the other skeletal elements. the estimated age of death was calculated according to the stage of fusion of the long bone epiphyses, and tooth eruption, replacement and wear stages according to gipson et al. (2000) for north american wolves, bull & payne (1982) for s. scrofa from turkey, mariezkurrena (1983) for c. elaphus from cantabria (spain) (for red deer and fallow deer), and barone (1974, 1981) and grant (1982) for present-day domestic cattle (as a proxy for b. primigenius). the estimate of the withers height was carried out by multiplying the maximum length of long bones, taken according to driesch (1976), by the coefficients of harcourt (1974) and clark (1995) for prehistoric dog (as a proxy for c. lupus), of teichert (1969) for present domestic pig (as a proxy for s. scrofa), of matolcsi (1969) for present domestic cattle (as a proxy for b. primigenius) and those reported by wilkens (1989) for prehistoric red deer. even if the biology and ontogeny of the pleistocene mammals may be different from present-day domestic cattle, domestic pig, prehistoric dog and modern wolf, wild boar and red deer, the estimated relative ages and withers height can be reconstructed with confidence, and they are probably similar. finally, several sediment samples from all layers have been washed through a 125μm mesh sieve looking for ostracods, but these have not been found. 4. results 4.1. preservation status of the bone remains the recent observations substantially confirm what reported by pandolfi et al. (2013a). except for bed 0 and 1 where there is little to be observed, in all the beds 2-7 the bones of large mammals are generally chaotically disposed, with the long bones lying mainly parallel to the stratigraphic surface but without a predominant orientation. also in bed 8, the same spatial disposition was observed, but the long bones parallel to the stratigraphic surface were mostly at the bottom of the stratum. in this bed, there are a few well preserved remains that represent about 13% of the large mammal assemblage from this horizon. concreted remains are abundant (about 60%), as well as the very damaged remains (about 20%) (fig. 2). observation of the bone surfaces in search of possible modifications is very difficult, especially for the presence of calcareous concretions. however, on the surface of the well preserved bones no clear evidences of human activity and of gnaw-marks by carnivores have been observed. according to pandolfi et al. (2013a), the preservation status of the bone remains of the large mammals in the underlying layers is as follows. the majority of the bed 2 remains (about 83%) are very well preserved, and a modest number of remains (about 12%) are slightly damaged through crushing or pressure and occasional bones have calcareous concretions (about 3%). in the beds 3 and 4 the bone remains are in not good conditions of preservation, but are not concreted. instead, most of the remains of bed 5 are in a very good state of preservation (about 88%), several bones are still articulated and only about 11% of the remains are slightly crushed. in bed 6 the bones in a good state of preservation (about 73%) are fewer than in the previous bed, whereas there is an increase in the percentage of dam 104 fig. 2 avetrana (southern italy), late pleistocene: percentages of preservation of the fossil bones of large mammals recovered in the different beds. salari l. et al. aged, and those concreted reappear. the well preserved bones is relatively low (about 35%) in bed 7, and there is an increase in the percentage of damaged and concreted bones (fig. 2), although some are in anatomical connection. concerning the possible modifications on the bone surfaces, were noticed only a probable intentional fracture on a humerus of hippopotamus from bed 6 (petronio et al., 2008) and a pair of cut-marks on the aurochs phalanges from the same horizon, whereas clear evidences of gnaw-marks by carnivores are very rare. 4.2. population analysis of representative mammal species population analyses were undertaken on certain mammal species well represented in the bed 8, often by both young and adult individuals. these are wolf, wild boar, red deer, fallow deer and aurochs. for the other mammal species we will only provide a description of representative remains. carnivore and ungulate remains of bed 8 considered here are over 550 identified specimens (tab. 2). 4.2.1. canis lupus the wolf occurs in all the beds, invariably represented by few fossil remains, except for beds 0 and 1, where it is absent (petronio et al., 2008; pandolfi et al., 2013a), and bed 8, where it is one of the species with the greatest nisp (tabs 2-3). in this bed, c. lupus is represented almost only by teeth, isolated or associated with mandible and maxilla portions (fig. 3a-c) or fragments, and by several postcranial bones (tab. 3). in extant wolves, the permanent teeth replace the deciduous ones between weeks 16 and 26, and the epiphyseal cartilage of the long bones calcifies around the 12th month (mech, 1974). among the wolf remains from bed 8, all the isolated teeth and the maxillary and mandibular teeth are permanent, and all the post-cranial bones have the epiphyses fused. thus, the mni, calculated by the lower carnassial (m1), is 14 adult individuals and therefore, according to this computation, the wolf is the best represented species 105 (tabs 2 and 4). all the m1 have the occlusal surfaces slightly or not worn, indicating a death age between 6-8 months and 6 years, except for an individual of about 8 years (fig. 3c). the long bones are often fragmented and it was then possible to estimate the withers height only by a small-sized femur and a second metatarsus: the withers height is 64.2 and 67.7 cm, respectively. concerning the size, based on the upper and lower carnassial teeth compared with those of south-western europe wolves, c. lupus from avetrana bed 8 falling within the variability of the mis 3 french wolves and to the largest late middle and late pleistocene italian wolves (bertè & pandolfi, 2014; sansalone et al., 2015; salari et al., 2017). using the coefficients by boudadi-maligne (2010, tabs 20 and 21), based on lower carnassial surface (length x breadth of m1), salari et al. (2017) estimated also the body mass and the body length for the avetrana wolves. according to this calculation too, c. lupus from bed 8 is among the largest wolf from late middle and late pleistocene of italy, with body mass up to 43.1 kg, mean 37.4 kg, and body length up to 167 cm, mean 157 cm. instead, the wolf from bed 5 and bed 6 are smaller in size, with body mass of 32.3 and 29.8 kg and body length of 153 and 149 cm, respectively. 4.2.2. sus scrofa in the avetrana succession, s. scrofa is poorly represented, being present only in the beds 2, 5 and 6 with a few fossil remains, and bed 8 (petronio et al., 2008; pandolfi et al., 2013a). in bed 8, the species with 37 identified specimens (tabs 2-3) is better represented than in the underlying beds. wild boar remains are a maxilla and four mandibles with deciduous and permanent teeth, and some post-cranial bones with fused and unfused epiphyses referable to at least 6 individuals (tabs 3-4): a very young of about three months, represented by an isolated and slightly worn lower fourth deciduous tooth (d4; fig. 3d), a young individual of about one year, represented by a portion of mandible with worn d4 and second molar (m2) erupting, a youngadult and three adult individuals. these occur with a tab. 2 avetrana (southern italy), bed 8, late pleistocene: number of identified specimens (nisp) and minimum number of individuals (nmi) of carnivores and ungulates. late pleistocene faunal assemblages from avetrana (italy) months old, represented particularly by femurs of different sizes with unfused epiphyses, whereas a slightly worn d4 indicates the presence of a young of about 8 months in age. two right metatarsal bones with the epiphyses fused attest the presence of two adult individuals, whereas humerus and femur with the epiphyses fused, but with the epiphyseal suture well appreciable in the proximal end, indicate the occurrence of at least a young-adult of about 32 months old. in this bed, the long bones are often fragmented or belonging to young individuals and it was not possible to estimate the withers height. instead, in the levels below it was possible to perform this estimate that, for example, it result 120 cm by metatarsus and 114 cm by calcaneus, in the beds 5 and 7, respectively. dimensional comparison is possible by the only well preserved skeletal element from bed 8, an astragalus similar in size (greater lateral length, gll: 54.3 mm) to those of the underlying beds (gll from 51.3 to 56.7 mm, mean 54.4 mm). portion of maxilla and two incomplete mandibles (fig. 3e) with unworn upper and lower third molars (about two years in age) and three with upper third molar (m3) at different wear stages (older than two years). by a well-preserved astragalus was estimated the withers height, that is 104 cm, very similar to those of s. scrofa from bed 5 (104 and 102 cm, by third metatarsus and astragalus, respectively). 4.2.3. cervus elaphus remains of young and adult red deer were recovered in all the beds 2-7, always with percentages between 7 and 9.9% in nisp (petronio et al., 2008; pandolfi et al., 2013a). according to the nisp (tab. 2), in the bed 8 c. elaphus is the third represented species (12.8%). unlike other species, the red deer is best represented by long bones rather than by teeth (tab. 3; fig. 3f), and these fossil remains can be referred to at least 6 individuals, including 2 adults, a young-adult and 3 young (tab. 4). two young individuals have an estimated age of 18-24 106 >>>>> fig. 3 avetrana (southern italy), bed 8, late pleistocene: canis lupus: maxillary portions, a1) and b1) labial view, a2 and b2) occlusal view; mandible fragment, c1) lingual view, c2) labial view; sus scrofa: d) lower fourth deciduous; e) mandible portions in occlusal view; cervus elaphus: f) mandible portion in lingual view; dama dama: g) lower third molar; bos primigenius: h) lower fourth deciduous; i) mandible portion in labial view; mustela putorius: l) sub-intact mandible in labial view; stephanorhinus hemitoechus: m) proximal third metacarpal. scale bar = 5 cm, except for l) = 3 cm. salari l. et al. tab. 3 avetrana (southern italy), bed 8, late pleistocene: skeletal elements of the most representative mammals. 107 late pleistocene faunal assemblages from avetrana (italy) 4.2.4. dama dama the fallow deer is the second most abundant species, after b. primigenius, in the beds 2 -7 with percentages of about 10-15%, and it is especially frequent in beds 5 and 7 (petronio et al., 2008; pandolfi et al., 2013a). in the bed 8, instead, it is the fourth species with 8.1% in nisp (tabs 2-3). the wear stages of teeth allow the recognition of two adults of different estimated ages according to the third lobe of the third lower molar (fig. 3g), which has different wear stages, and three young individuals (tab. 4). these are represented by left d4, which show different wear stages, and in particular one with an estimated age younger than 8 months and two with an estimated age about 20 months old. regarding the sizes, also for d. dama the only well preserved skeletal element is the astragalus showing similar dimensions (gll: 42.4 and 44.4 mm) to those of the underlying layers (e.g., gll: 42.7 and 44.7 in bed 5). 4.2.5. bos primigenius the aurochs is very well represented in the site of avetrana: except for bed 0, in which it is absent, and bed 1, where it is the only large mammal, it accounts for about 60% of identified specimens (pandolfi et al., 2013a). so far, were found remains of long bones, vertebrae, ribs, phalanges and teeth referable to at least 53 individuals (of which 5 from bed 8; see pandolfi et al., 2013a, table 1), to ascribe to adult and subadult individuals, including very young individuals (petronio et al., 2008; pandolfi et al., 2011, 2013a). according to the new data presented here, in the bed 8 the aurochs remains are fewer than the underlying beds. indeed, b. primigenius is represented by 219 specimens (39.4%) referable to at least 12 individuals (tabs 2-4): a very young calf, represented by an isolated unworn d4 (fig. 3h), three calves represented by mandibles with d4 with light wear stage (two 4-5 months and one 6-8 months in age), a young adult with d4 very worn, two about 3-years adult individuals represented by fragmented mandibles with the third lobe of the lower third molar (m3) slightly or not worn, four about 4-years adult individuals with mandible portions with the m3 averagely worn (fig. 3i), and an old individual represented by a mandible portion with very worn m3. overall, there are the bone remains of at least 60 individuals in the fossiliferous deposit. the long bones in bed 8 are many fragmented and it was then possible to estimate the withers height only by a metacarpus referable to an individual of indeterminate sex (db/l index = 33.1; mb/l index = 18.1; see howard, 1963). the withers height is 160.7 cm, which falls into the average of the withers height estimated by metacarpal bones of b. primigenius from the beds below (between 151.4 and 165.8 cm; pandolfi et al., 2013a), which are among the largest in size of the middle and late pleistocene aurochs of italy (pandolfi et al., 2011, 2013a). 108 4.2.6 other carnivores and pachyderms among the other carnivores and ungulates, the most abundant is vulpes vulpes. remains of this species always occur in the beds 2-7, even though they are relatively scarce (petronio et al., 2008). in bed 8 the fox is represented by 18 identified specimens (tab. 2): isolated teeth (upper incisive, upper canine, upper and lower premolars and molars), maxilla fragment, almost complete mandible, proximal and distal humerus, distal femur, distal tibia, third metacarpus, third metatarsus and first phalanx referred to adult individuals; other remains are constituted by deciduous lower canine, fifth metacarpus and first phalanx with unfused epiphyses belonging to a cub. mustelid remains in the underlying beds are represented only by the badger, meles meles, which occurs in the beds 2, 3 and 5, always with a few remains (petronio et al., 2008). in bed 8, a sub-intact mandible attributed to the polecat, mustela putorius, were found (pandolfi et al., 2013a; fig. 3l), together with a fragmented coxal referred to martes sp., and first and second lower molars belonging to m. meles (tab.2). regarding the felids, lynx lynx occurs in the bed 2 and 5, and felis sylvestris in the bed 0, invariably with very scarce remains (petronio et al., 2008). in the bed 8 the wild cat is present with a lower carnassial and two first phalanges belonging to an adult individual and with a proximal radius referred to a cub (tab. 2). a premolar tooth is assigned to l. lynx by petronio et al. (2008), instead another premolar and three small first phalanges can be referred to a small size lynx, such as l. pardinus, also attested in italy (rodríguez-varela et al., 2015); for this reasons, these finds were prudently attributed to lynx sp. (tab. 2). calcaneus and fourth metacarpus portions also attest the occurrence of panthera spelaea in this bed. crocuta crocuta remains of a few adult individuals were collected in the beds 2, 5, 7 (petronio et al., 2008) and 8, where the spotted hyena is represented by isolated teeth, fragmented maxilla and mandibles and a diaphysis of femur belonging to adult individuals (tab. 2). in addition, fossil remains belonging to a very young and an adult individual of steppe rhinoceros, stephanorhinus hemitoechus, occur in the beds 2, 6 and 7 (petronio et al., 2008; pandolfi et al., 2013a), while hippopotamus amphibius occurs with rare remains in the beds 2, 5 and 6. moreover, a proximal third metacarpal (fig. 3m), a juvenile third cuneiform and a fragment tab. 4 avetrana (southern italy), bed 8, late pleistocene: minimum number of individuals of the most representative mammals; yy: very young; y: young; y-a: young-adult, a: adult; o: old. salari l. et al. of a third metatarsal attributed to s. hemitoechus (see pandolfi et al., 2017b) were collected from bed 8. 4.3. remarks on the other taxa 4.3.1 small mammals the small mammals of bed 8, erinaceus europaeus, crocidura suaveolens, arvicola italicus, microtus (microtus) arvalis, hystrix vinogradovi, oryctolagus cuniculus, lepus corsicanus, are studied in kotsakis et al. (in press). in bed 8 are collected many dental remains of a large arvicolid that do not present diagnostic characters can however be attributed with great probability to the genus arvicola, the only genus of the late pleistocene (and current) fauna of the italian peninsula of this size. pandolfi et al. (2013a) also report the occurrence of microtus (terricola) savii, which is present with few remains even in the beds 0, 1, 5 and 6 (kotsakis et al., in press). 4.3.2. birds bird remains are relatively scarce and are generally fragmented and in not good conditions of preservation. only in the fissures at the bottom of the succession (bed 0) they are numerous and are chiefly represented by anterior limb bones belonging to perdix perdix, columba livia, athene noctua, and pyrrhocorax graculus. the most abundant in bed 0 is c. livia followed by p. graculus, while the other species are present with only one fossil remain (sardella et al., 2005; petronio et al., 2008). columba livia was found in every bed, always represented by few remains; whereas aquila sp., otis tarda and p. pyrrhocorax were sporadically found and each taxon is represented by only one fossil remain (petronio et al., 2008). in bed 8 were recovered 18 bird remains, including a distal left tibiotarsus attributed to aquila sp., two distal humeri and a sub-intact left ulna referred to columba sp., several fragmented distal ulnae and a proximal right carpometacarpus of corvidae which shown the features of genus pyrrhocorax, but not attributable to species level, and a sub-intact left humerus, posterior phalanx, proximal and distal tibiotarsus and tarsometatarsus belonging to p. pyrrhocorax. 4.3.3. amphibians and reptiles the fossil remains of amphibians and reptiles of bed 8, bufo bufo, bufotes gr. b. viridis, hyla gr. h. arborea, testudo hermanni, podarcis sp., serpentes indet., are studied together with the small mammals in kotsakis et al. (in press). bed 8 differs from the underlying beds by the abundant fragments of non-classifiable anurans. 5. lithic artefacts in bed 8, a retouched hypermicro flake (< 2 cm) was found with simple and inverse retouching on the left side, faceted convex platform (fig. 4). the artefact presents, on the right side, a recent detachment with glossy patina. similar glossy patina, subsequent the production of the instrument, is present in the detachment of the retouching. the silex is of medium quality, with a light superficial usury patina. it is yellowish light brown in colour, 2.5 y 6/4 according to the munsell soil color charts (munsell color company, 1994); with a height of 17 mm, a width of 23 mm, and a thickness of 4 mm. the evidence of a double patina suggests a reuse of the object after the production and its first use. the presence of the prepared platform and the retouching are not discriminant for a chronological attribution, moreover it is conceivable to date the object between the end of the lower and the middle palaeolithic, very close to the mousterian lithic industry. similar artefacts are present also in the upper palaeolithic levels of the archaeological sites. in addition to the one described above, a single mousterian lithic artefact, a déjeté side-scraper, was also found in the bed 6 (petronio et al., 2008). 6. discussion 6.1. deposition of bed 8 and of the bone accumulation regarding the genesis of bed 8, the previous and recent observations made on the structure of the uppermost bed of the karst cavity filling, on the deposit sediments, on the physical status and spatial disposition of the fossil bones, suggest that water has been the main, if not the only one, depositional factor also for this bed. in bed 8, there is a high percentage of damaged and concreted bone remains. many bones are fractured, but no clear evidences of human activity and of gnawmarks by carnivores have been identified. in the underlying beds many bones are complete, some of them articulated, particularly those of b. primigenius from bed 2, 5 and 7, without clear signs of transport suggesting that they were probably deposited rapidly during a short time span by exceptional events, resulting in the rapid incorporation of carcasses and isolated vertebrate remains in the karst cavity (petronio et al., 2008; pandolfi et al., 2013a). clear signs of gnawmarks by carnivores are very rare, as well as cut-marks or other traces of human activity (petronio et al., 2008). the lithic artefact recovered in bed 8, as well as 109 fig. 4 avetrana (southern italy), bed 8, late pleistocene: lithic artefact (drawn by martina de marzi). late pleistocene faunal assemblages from avetrana (italy) the one found in bed 6 (petronio et al., 2008), was probably transported by water and suggests the frequentation of humans in the surrounding of the area, but without an active role in the deposition. mousterian lithic industries have been found in many palaeolithic archaeological sites of apulia (palma di cesnola, 2001). only on the ionic side of the region, can one recall grotta di uluzzo c (borzatti von löwerstern & magaldi, 1969), grotta di capelvenere (giusti, 1980), grotta di serra cicora (campetti, 1986), grotta del cavallo (sarti & martini, 2008) and grotta bernardini (carmignani & romagnoli, 2017) around nardò, and riparo dell’oscurusciuto near ginosa (boscato et al., 2011); a few mousterian stone tool are also reported at cava spagnuolo near grottaglie (mecozzi et al., 2018). the result of population analyses of some representative mammal species from bed 8 does not show a precise time interval for the deposition of the bone remains. the wolves are all adults, the young of s. scrofa show ages of three months and one year, those of c. elaphus and d. dama around 8 and 20 months and, finally, the young of b. primigenius have an estimated age of 1, 4-5 and 6-8 months old. in wild boar the births occur during spring, in red deer the births usually occur in late spring or early summer, in fallow deer the births occur usually from late may to early june, and the aurochs calves were presumably born in spring, as in the majority of modern free-range domestic cattle (hopf, 1979; feldhamer et al., 1988; nowak & paradiso, 1991; patent, 1993; boitani et al., 2003). thus, the age of death particularly of young animals suggests that these bones have been accumulated throughout all the year. instead, in some underlying beds, and particularly in beds 5 and 7, the age of young animals pinpoints the time of death between late autumn and winter. in these beds, the young of c. elaphus and d. dama have an estimated age around 8 or younger than 24 months old, and the vast majority of b. primigenius individuals show an age around 6, 18 and 30 months (pandolfi et al., 2013a). new observations on the preservation of the bone remains and population analyses tend to confirm that bed 8 was probably deposited over a long time span, with frequently stagnant water (pandolfi et al., 2013a), also suggested by the occurrences of a. italicus and several species of anura (kotsakis et al., in press) and the presence of many calcareous concretions on the fossil bones. except for very few specimens in bed 2, concreted bones appear in bed 6, increase in number and percentage in bed 7 and are the majority of large mammal remains in bed 8 (fig. 2). probably there was a good drainage of water in the cavity up to a certain level. then, after the catastrophic event of bed 5, from bed 6 water began to stagnate on the surface of the deposit. at the time of deposition of bed 8, a puddle of water or a pond was likely at the top of the cavity filling. any downpours would have transported animal carcasses and scattered bones, allowing them to accumulate in the pond, or puddle of water, at the top of the karst cavity filling. as for the high percentage of carnivore remains, above all of wolf, in the bed 8, pandolfi et al. (2013a) supposed that may be due to the presence of dens and/ or to the common attendance in the area of this canid, or that the cavity worked like a trap. the non-appearance of obvious gnaw-marks on the bones together with the absence of coprolites and of cub remains of wolf and spotted hyena (although absence of evidence is not evidence of absence) tend to exclude that this part of cavity was utilized as den by the large carnivores (see sutcliffe, 1970; egeland et al., 2008; yravedra et al., 2011, 2012). in fact, the very few remains of young carnivores belong to medium-small size species, such as wild cat and fox, which do not accumulate bones of large herbivores. therefore, the role of a natural trap of the residual cavity, where the carnivores, especially physically adult wolves, but not experienced yet, could have been attracted by the presence of animal carcasses, seems to be the most likely hypothesis. 6.2. palaeoenvironmental considerations the faunal assemblages recovered from the sequence provide useful information on the evolution of the environment in response to climate changes. the bird and small mammal remains from the two fissures, or pockets, at the bottom (bed 0), if these were not filled only by small osteological materials which could pass through the small karstic fissures, suggest the presence of a poorly forested environment characterized by ample spaces with the presence of rocky outcrops. this aspect is indicated by the occurrence of m. (t.) savii, h. vinogradovi, and the lagomorphs and particularly by the avifauna. in fact, the fossil remains of birds found in bed 0 belong to a few species linked to an open environment with rocky outcrops. columba livia prefers rocky environments and sea-cliffs, and avoids areas of tall and dense vegetation (gibbs et al., 2001), p. perdix inhabits steppe regions and open areas in temperate zone, and p. graculus, the most abundant bird after c. livia, attends high-altitude mountain pastures with rocky ravines and cliff faces (birdlife international, 2018). the recent distribution range of this corvid today includes the alpine arc and the central and northern apennine (birdlife international, 2018), however in corsica it goes down to sea-cliffs (louchart, 2002). the occurrence of p. graculus, rather than indicating mo 110 fig. 5 avetrana (southern italy), late pleistocene: percentage changes of mammal fossils (nisp). salari l. et al. ments of climatic deterioration, would testify to the presence of rocky outcrops in the surrounding of the site or of crags in the near coast (today a few kilometres from avetrana). regarding the beds 1-7, the ecological requirements of the large mammals allow reconstruction of the palaeoenvironment around avetrana during the early late pleistocene. the climate was probably characterized by temperate-warm conditions, with dominance of woodland with different vegetation that suggests the occurrence of rainy winters and dry summers (pandolfi et al., 2013a). the great quantity of aurochs, the presence of fallow deer more abundant than red deer (fig. 5), and scarce rhinoceros, suggest a landscape with large wooded areas, rich in glades or localised open spaces (or diffuse mediterranean scrub); wild boar and hippopotamus (less than 2%) suggest the presence of more water bodies than today (petronio et al., 2008; pandolfi et al., 2013a). in this phase, peak maximum vegetation cover can be recorded in bed 7 (maximum frequency of cervids; pandolfi et al., 2013a, table 4) and bed 5 (occurrence of capreolus capreolus). the faunal assemblage from bed 8 consists of the same herbivores of the underlying layers, but the aurochs decrease, wild boar increase, red deer is more numerous than the fallow deer (fig. 5) and lacks the hippopotamus (tabs 1-2). there are also abundant wolves, and among the small rodents, m. (m.) arvalis appears (kotsakis et al., in press). the increase of s. scrofa up to 6.7%, widely compensating the absence of the hippopotamus, suggests more water bodies than the underlying beds, as attested also by the abundance of water vole and frogs (kotsakis et al., in press). the largest percentage of c. elaphus compared to d. dama seems to indicate an environment with forests alternating with glades, but with less warm climate than in the beds 2-7. the common vole, m. (m.) arvalis, is a typical rodent of open areas with poor herbaceous cover, and it currently occurs in continental europe and northern italy (paolucci & amori, 2008), but it is relatively frequent in the fossil mammal assemblages since the late middle pleistocene also in central and southern italy, except for the last interglacial and the late holocene (kotsakis et al., 2003, in press; kotsakis, 2008; salari, 2014). these evidences, along with the above observations on the genesis of the bed 8, suggest a climate deterioration and an environment somewhat similar, but with more water bodies, and likely wider open spaces (also indicated by lagomorphs), than that suggested by the mammal assemblages from the underlying beds. palaeoenvironmental indications are generally compliant with those derived from the study of small vertebrates (kotsakis et al., in press), which suggest the presence of a coastal plain with marshes bordered by wooded areas, open spaces and with rocky coastal areas nearby. 6.3. biochronological implications so far, the entire mammal assemblage of the stratified deposit from avetrana was referred to melpignano faunal unit and related it to the early late pleistocene, mis 5, or restricted to mis 5e, on the basis of palaeoenviromental and biochronological considerations (petronio et al., 2008; pandolfi et al., 2013a). in particular, these authors have pointed out the occurrence in the site of the modern forms of c. elaphus and d. dama, that occur for the first time in italy at the beginning of the late pleistocene (petronio et al., 2007, 2011), of h. amphibius and h. vinogradovi, that occur for the first time in western europe in the middle pleistocene and are relatively frequent during mis 5 to become then progressively rarer in mis 4 and mis 3, until their extinction (salari & sardella, 2009, 2011; pandolfi and petronio, 2015), and the large size of long bones of b. primigenius. in fact, this species occurs for the first time in southern europe in the middle pleistocene with smallsized specimens, tends to increase in body size during the late middle and early late pleistocene and then decreases in body size during the second part of the late pleistocene and in the holocene (pandolfi et al., 2011, 2013a). for the chronological attribution, pandolfi et al. (2013a, with references and discussion) made additional comparisons with pollen diagrams of central and southern italy (e.g., follieri et al., 1995), with sapropel levels recorded in the marine stratigraphy of mediterranean basin, and in particular with the sapropel levels s5, s4 and s3 that mark the warm peaks of mis 5 (5e, 5c and 5a respectively) in the western mediterranean sea (e.g., capotondi & vigliotti, 1999), and with other early late pleistocene sites (or parts of stratigraphic sequences) of apulia, such as cava nuzzo, san sidero 3, grotta del cavallo, grotta di uluzzo c, grotta delle striare, grotta del sarcofago etc. the biochronology of micromammals also support these chronological indications. indeed, all the species found in the avetrana karst filling first appear in italy since the middle pleistocene, except for a. italicus and c. suaveolens, recorded only since the late pleistocene (kotsakis et al., 2003, in press; kotsakis, 2008; gatta et al., 2019). in bed 8, the large mammals are almost the same to the underlying beds (tab. 1), but with a very high percentage of carnivore remains (fig. 5) and with significant variations in percentage and/or in body size, particularly for the wolf. moreover, among the cervids, the red deer is more abundant than the fallow deer. according to bertè & pandolfi (2014) the relatively great size of the wolf from avetrana bed 8 suggest a new dispersal event of c. lupus in italy (the so-called “glacial wolves” in mecozzi & bartolini lucenti, 2018, or the “würmian wolves” auctorum), rather than a local adaptation or a body size increase due to climate changes. the dimensions clearly separate them from the older small-sized wolves from melpignano area, grotta romanelli and ingarano (the so-called “apulian wolves”; sardella et. al., 2014). maybe it is no coincidence that the body length and body mass of the wolf from the underlying beds 5 and 6 of avetrana are smaller than that of bed 8. indeed, body length and body mass of the wolf from beds 5 and 6 are close to the medium values of c. lupus from san sidero 3 (de giuli 1983; salari et al. 2017), referred to mis 5e (conti et al., 2010; masini & sala, 2011), that seems to prelude to the following re 111 late pleistocene faunal assemblages from avetrana (italy) duction in size of the aforementioned so-called “apulian wolves”, between mis 5c-a and mis 3 (bertè and pandolfi, 2014; sardella et al., 2014; salari et al., 2017). furthermore, among the small rodents m. (t.) savii persist and m. (m.) arvalis occurs (pandolfi et al., 2013a; kotsakis et al., in press), and among the pachyderms h. amphibius lack while s. hemitoechus persists (tabs 1 2). as mentioned above, m. (m.) arvalis occurs in italy since the late middle pleistocene, only being absent in central and southern part of the peninsula during the last interglacial and the late holocene, and is currently found only in northern italy where it is abundant in the fossil record (kotsakis et al., 2003, in press; kotsakis, 2008; paolucci & amori, 2008; salari, 2014). on the other hand, the steppe rhinoceros, s. hemitoechus, occurs in italy since mis 13 (pandolfi et al., 2013b; pandolfi & marra, 2015; pandolfi & tagliacozzo, 2015) and it was present at least until 41 ka cal. bp, mis 3 (pandolfi et al., 2017b). the great size of wolf, the red deer more numerous than the fallow deer, together to the aforementioned considerations on the palaeoenvironment reconstruction and, above all, the concomitant occurrence of m. (m.) arvalis and s. hemitoechus suggest that the mammal assemblage from bed 8 of the avetrana karst filling is younger in age than that of the beds below, and can be referred to an undefined time span between the first climatic deterioration of the last glacial period and the early mis 3, and it is attributable to the ingarano faunal unit (fig. 6). 7. conclusions the population analyses of some representative mammal species and the remarks on the preservation of the bone remains showed that bed 8, at the top of the sequence of the stratified fossiliferous deposit from la grave near avetrana (apulia, italy), displays features indicating its origination in sedimentary, climatic and environmental conditions quite different from those of underlying beds. the sedimentological characteristics, the physical status and the spatial disposition of the fossil bones of bed 8, suggest the presence of abundant water in the highest part of the sub-vertical karst cavity and in the surrounding of the site, at the time of its deposition. stagnant water did not promote a good bone remains conservation and many calcareous concretions are observed on the bone surfaces. the abundance of stagnant water is also showed by the occurrence of numerous fossil remains of several species of anura and of arvicola italicus. the ecological features and the percentage ratios of mammal species found in the bed 8, indicate a moment of climate deterioration and an environment somewhat similar, but with more water bodies, and likely wider open spaces, than that suggested by the mammal assemblages from the underlying beds. most of the stratified karst filling (up to bed 7) and its mammal assemblages can be attributed to the early late pleistocene, mis 5e, melpignano faunal unit. however, significant variations in percentage and/or in body size of some species (particularly canis lupus) and 112 fig. 6 approximate position of the two mammal assemblages from avetrana karst filling in relation to the biochronological scheme for the aurelian mammal age (late middle to late pleistocene). salari l. et al. the concomitant occurrence of stephanorhinus hemitoechus and microtus (microtus) arvalis suggest that the mammal assemblage from bed 8 is younger in age than that of underlying beds, even if it is not possible to identify, at the moment, a precise time interval, presumably between the onset of the last glacial period and the early mis 3. therefore, the mammal assemblage of bed 8 can be referred to the ingarano faunal unit. the high percentage of wolf in the bed 8, indicate that the residual cavity probably worked like a trap for adult wolves, attracted by the presence of animal carcasses. finally, the lithic artefacts recovered in bed 8 and in bed 6 only testify the attendance of neanderthal humans in the surrounding of la grave at avetrana. acknowledgements we thank the municipality and the “associazione pro loco” of avetrana for the kind hospitality. we are also grateful to eline van asperen, juan manuel lópezgarcía and a third anonymous reviewer for their valuable comments and suggestions. references aguirre m.l., zanchetta g., fallick a.e. (2002) stable isotope composition of littoridina australis from the coast of buenos aires province, argentina, during holocene climatic fluctuations. geobios, 35, 79-88. barone r. (1974) anatomia comparata dei mammiferi domestici. 1, osteologia. edagricole, bologna, pp. 644. barone r. (1981) anatomia comparata dei mammiferi domestici. 3, splancnologia. edagricole, bologna, pp. 210. bertè d.f., pandolfi l. (2014) canis lupus (mammalia, canidae) from the late pleistocene deposit of avetrana (taranto, southern italy). rivista italiana di paleontologia e stratigrafia, 120, 367-379. birdlife international (2018) iucn red list for birds. http://www.birdlife.org (accessed 09 march 2018). boitani l., lovari s., vigna taglianti a. (2003) fauna d’italia. mammalia iii. carnivora artiodactyla. calderini, bologna, pp. 434. bologna p., di stefano g., manzi g., petronio c., sardella r., squazzini e. (1994) late pleistocene mammals from the melpignano (le) «ventarole»: preliminary analysis and correlations. bollettino della società paleontologica italiana, 33, 265-274. borzatti von löwerstern e., magaldi d. (1969) risultati conclusivi dello studio paletnologico e sedimentologico della grotta di uluzzo c (nardò-lecce). rivista di scienze preistoriche, 21, 16-64. boscato p., gambassini p., ranaldo f., ronchitelli a. (2011) management of palaeoenvironmental resources and raw materials exploitation at the middle palaeolithic site of oscurusciuto (ginosa, ta, southern italy): units 1 and 4. in: conard n.j., richter j. (eds.), neanderthal lifeways, subsistence and technology one hundred fifty years of neanderthal study, springer, berlin/heidelberg. bradbury a.p. 2010, 87-98. boudadi-maligne m. (2010) les canis pléistocènes du sud de la france: approche biosystématique, évolutive et biochronologique. thèse de doctorat, université bordeaux 1, pp. 448. bull g., payne s. (1982) tooth eruption and epiphysial fusion in pigs and wild boar. in: wilson, b., grigson, c., payne, s. (eds.), ageing and sexing animal bones from archaeological sites. british archaeological reports (british series), 109, 5571. campetti s. (1986) il musteriano della grotta di serra cicora nell’ambito dell’evoluzione del paleolitico nel salento. studi per l’ecologia del quaternario, 8: 85-115. capotondi l., vigliotti l. (1999) magnetic and microfaunal characterization of late quaternary sediments from the western mediterranean: inferences about sapropel formation and paleoceanographic implications. in: zahn r., comas m.c., klaus a. (eds.), proceedings of the ocean drilling program, scientific results, college station, 161, 505-518. carmignani l., romagnoli f. (2017) revisione dell’industria litica musteriana di grotta mario bernardini (nardò, lecce). in: radina f. (ed.), preistoria e protostoria della puglia. studi di preistoria, 4, 139144. clark k.m. (1995) the later prehistoric and protohistoric dog: the emergence of canine diversity. archaeozoologia, 7, 9-32. conti n., petronio c., salari, l. (2010) the equids of the late pleistocene of “tana delle iene” (ceglie messapica, brindisi, southern italy). bollettino della società paleontologica italiana, 49, 227-236. de giuli c. (1983) le faune pleistoceniche del salento 1: la fauna di san sidero 3. quaderni del museo comunale di paleontologia di maglie, 1, 45-84. driesch a. von den (1976) a guide to the measurement of animal bones from archaeological sites. peabody museum bulletin harvard university, 1, 1137. egeland a.g., egeland c.p., bunn h.t. (2008) taphonomic analysis of a modern spotted hyena (crocuta crocuta) den from nairobi, kenya. journal of taphonomy, 6, 275-299. feldhamer g.a., farris-renner k.c., barker c.m. (1988) dama dama. mammalian species, 317, 1-8. follieri m., giardini m., magri d., sadori l. (1995) fluttuazioni vegetazionali nel lazio durante l’ultimo glaciale. giornale botanico italiano, 129, 255-259. gatta m., kotsakis t., pandolfi l., petronio c., salari l., achino k.f., silvestri l., rolfo m.f. (2019) the late pleistocene faunal assemblage from cava muracci (latium, italy): palaeoenvironmental implications for coastal central italy during mis 3. comptes rendus palevol, 18, 51-71. gibbs d., barnes a., cox j. (2001) pigeons and doves. a guide to the pigeons and doves of the world. christopher helm, london (reprint 2010), pp. 615. gipson p.s., ballard w.b., nowak r.m., mech l.d. (2000) accuracy and precision of estimating age of gray wolves by tooth wear. journal of wildlife management, 64, 752-758. giusti m. (1980) la grotta di capelvenere a s. caterina nardò (campagna di scavo 1975). studi per 113 late pleistocene faunal assemblages from avetrana (italy) l’ecologia del quaternario, 2, 77-85. grant a. (1982) the use of tooth wear as a guide to the age of domestic animals. in: wilson b., grigson c., payne s. (eds.), ageing and sexing animal bones from archaeological sites. british archaeological reports (british series), 109, 91108. harcourt r.a. (1974) the dog in prehistoric and early historic britain. journal of archaeological science, 1, 151-175. hopf a. (1979) pigs: wild and tame. holiday house, new york, pp. 127. howard m. (1963) the metrical determination in the metapodials and skulls of cattle. man and cattle. royal anthropological institute, occasional paper, vol. 18, pp. 91-100. kotsakis t. (2008) storia paleontologica di erinaceomorfi, soricomorfi, lagomorfi e roditori attuali d’italia. in: amori g., contoli l., nappi a. (eds.), fauna d’italia, mammalia ii, erinaceomorpha, soricomorpha, lagomorpha, rodentia. calderini de il sole 24 ore, milano, 1-32. kotsakis t., abbazzi l., angelone c., argenti p., barisone g., fanfani f., marcolini f., masini f. (2003) plio-pleistocene biogeography of italian mainland micromammals. deinsea, 10, 313-342. kotsakis t., maiorino l., pandolfi l., petronio c., sansalone g., salari l. (in press) late pleistocene small vertebrates from the avetrana (apulia, southern italy) karst filling. estudios geologicos. louchart a. (2002) les oiseaux du pléistocène de corse et de quelques localités sardes écologie, évolution, biogéographie et extinctions. documents du laboratoire de géologie de lyon, 155, 1 -287. mariezkurrena k. (1983) contribucion al conocimiento del desarollo de la denticion y el esqueleto postcraneal de cervus elaphus. munibe, 35, 149202. masini f., sala b. (2011) considerations on an integrated biochronological scale of italian quaternary continental mammals. il quaternario italian journal of quaternary sciences, 24, 193-198. matolcsi j. (1969) historische erforschung der köpergrösse des rindes auf grund von ungarischen knochen material. zeitschrift fur tierzüchtung züchtungsbiologie, 87, 89-137. mech l.d. (1974) canis lupus. mammalian species, 37, 1-6. mecozzi b., bartolini lucenti s. (2018) the late pleistocene canis lupus (canidae, mammalia) from avetrana (apulia, italy): reappraisal and new insights on the european glacial wolves. italian journal of geosciences, 137, 138-150. mecozzi b., chakroun a., baills h., iurino d.a., sardella r., coppola d. (2018) late pleistocene mammal faunal assemblage from cava spagnulo (grottaglie, apulia, se italy). alpine and mediterranean quaternary, 31, 5-19. munsell color company (1994) munsell soil color charts, revised edition. macbeth division of kollmorgen, new windsor, new york (revised edition, 2000), pp. 50. mussi m. (2002) earliest italy. an overview of the italian paleolithic and mesolithic. springer, new york, pp. 399. nowak r.m., paradiso j.l. (1991) cervidae: deer. in: nowak r.m. (ed.), walker's mammals of the world (fifth edition), john hopkins university press, baltimore, 1207-1212. palma di cesnola a. (2001) il paleolitico inferiore e medio in italia. museo fiorentino di preistoria "paolo graziosi", firenze, pp. 352. pandolfi l., marra f. (2015) rhinocerotidae (mammalia, perissodactyla) from the chronostratigraphically constrained pleistocene deposits of the urban area of rome (central italy), geobios, 48, 147-167. pandolfi l., petronio c. (2015) a brief review of the occurrences of pleistocene hippopotamus (mammalia, hippopotamidae) in italy. geologica croatica, 68, 313-319. pandolfi l., tagliacozzo a. (2015) stephanorhinus hemitoechus (mammalia, rhinocerotidae) from the late pleistocene of valle radice (sora, central italy) and re-evaluation of the morphometric variability of the species in europe. geobios, 48, 169191. pandolfi l., petronio c., salari l. (2011) bos primigenius bojanus, 1827 from the early late pleistocene deposit of avetrana (southern italy) and the variation in size of the species in southern europe: preliminary report. journal of geological research, 2011: id 245408,1-11 pandolfi l., petronio c., salari l. (2013a) catastrophic death assemblages from the late pleistocene of italy: the case of avetrana karst filling (taranto, southern italy). rivista italiana di paleontolgia e stratigrafia, 119, 109-124. pandolfi l., gaeta m., petronio c. (2013b) the skull of stephanorhinus hemitoechus (mammalia, rhinocerotidae) from the middle pleistocene of campagna romana (rome, central italy): biochronological and paleobiogeographic implications. bulletin of geosciences, 88, 51-62. pandolfi l., mannino m.a., talamo s., salari l., sansò p., sublimi saponetti s., vacca e., vicari d., richards m.p., petronio c. (2017a) a reassessment of the infills and faunal assemblages of karst cavities known as ventarole in salento (apulia, southern italy): a multidisciplinary investigation on cava donno (corigliano d’otranto, lecce). alpine and mediterranean quaternary, 30, 25-40. pandolfi l., boscato p., crezzini j., gatta m., moroni a., rolfo m.f., tagliacozzo a. (2017b) latest pleistocene occurrences of stephanorhinus hemitoechus (mammalia, rhinocerotidae) in the italian peninsula. rivista italiana di paleontolgia e stratigrafia, 123, 177-190. paolucci p., amori g. (2008) microtus arvalis (pallas, 1778). in: amori, g., contoli, l., nappi, a. (eds.), fauna d’italia, mammalia ii, erinaceomorpha, soricomorpha, lagomorpha, rodentia. calderini de il sole 24 ore, milano, 494-503. patent d.h. (1993) cattle. carolrhoda books, minneapolis, pp. 48. 114 salari l. et al. petronio c., bellardini f., arzarello m., bedetti c., bellucci l., cipullo a., di stefano g., pandolfi l., pavia m., petrucci m., sardella r., salari l. (2008) the deposit of the late pleistocene from avetrana (taranto, southern italy): biochronology and palaeoecology. il quaternario italian journal of quaternary sciences, 21, 409-422. petronio c., billia e., capasso barbato l., di stefano g., mussi m., parry s.j., sardella r., voltaggio m. (1996) the late pleistocene fauna from ingarano (gargano, italy): biochronological, palaeoecological, paleoethnological and geochronological implications. bollettino della società paleontologica italiana, 34, 333-339. petronio c., bellucci l., martinetto e., pandolfi l., salari l. (2011) biochronology and palaeoenvironmental changes from the middle pliocene to the late pleistocene in central italy. geodiversitas, 33, 485 -517. petronio c., di canzio e., salari l. (2007) the late pleistocene and holocene mammals in italy: new biochronological and paleoenvironmental data. palaeontographica, abt. a 279, 147-157. rodríguez-varela r., tagliacozzo a., ureña i., garcía n., crégut-bonnoure e., mannino m.a., arsuaga j.l., valdiosera c. (2015) ancient dna evidence of iberian lynx palaeoendemism. quaternary science reviews, 112, 172-180. rustioni m., mazza p., abbazzi l., delfino m., rook l., petrucci s., vianello f. (1994) the würmian fauna from sternatia (lecce, apulia, italy). bolletino della società palentologica italiana, 33, 279-288. salari l. (2014) holocene micromammals (soricomorpha and rodentia) from some caves of central italy. revue de paléobiologie, 33, 79-96. salari l., sardella r. (2009) the pleistocene porcupine hystrix vinogradovi argyropulo, 1941 in italy. bollettino della società paleontologica italiana, 48, 123-127. salari l., sardella r. (2011) il genere hystrix linnaeus, 1758 in italia nel pleistocene. atti della società toscana di scienze naturali, memorie a, 116, 171 -178. salari l., achino k.f., gatta m., petronio c., rolfo m.f., silvestri l., pandolfi l. (2017) the wolf from grotta mora cavorso (simbruini mountains, latium) within the evolution of canis lupus l., 1758 in the quaternary of italy. palaeogeography palaeoclimatology palaeoecology, 476, 90-105. sansalone g., bertè d.f., maiorino l., pandolfi l. (2015) evolutionary trends and stasis in carnassial teeth of european pleistocene wolf canis lupus (mammalia, canidae). quaternary science reviews, 110, 36-48. sardella r., bedetti c., bellucci l., conti n., coppola d., di canzio e., pavia m., petronio c., petrucci m., salari l. (2005) the late pleistocene vertebrate fauna from avetrana (taranto, apulia, southern italy): preliminary report. geo.alp, 2, 25-29. sardella r., bertè d., iurino d.a., cherin m., tagliacozzo a. (2014) the wolf from grotta romanelli (apulia, italy) and its implications in the evolutionary history of canis lupus in the late pleistocene of southern italy. quaternary international, 328, 179-195. sarti l, martini f. (2008) grotta del cavallo (nardò, prov. di lecce). rivista di scienze preistoriche, 58, 421-422. sutcliffe a.j. (1970) spotted hyaena: crusher, gnawer, digester and collector of bones. nature, 227, 11101113. teichert m. (1969) osteometrische untersuchungen zur berechnung der widerristhohe bei vor-und fruhgeschichtlichen schweinen. kuhn-archiv, 83, 237-292. wilkens b. (1989) il cervo dal mesolitico all’età del bronzo nell’italia centro-meridionale. rassegna di archeologia, 8, 63-95. yravedra j.s., lagos l., bárcena f. (2011) a taphonomic study of wild wolf (canis lupus) modification of horse bones in north-western spain. journal of taphonomy, 9, 37-66. yravedra j.s., lagos l., bárcena f. (2012) the wild wolf (canis lupus) as a dispersal agent of animal carcasses in northwestern spain. journal of taphonomy, 10, 227-247. 115 late pleistocene faunal assemblages from avetrana (italy) ms. received: december 12, 2018 final text received: may 10, 2019 116 amq 25 martinetto impaginato 30072014 available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 27 (1), 2014, 29 72 the plant record of the dunarobba and pietrafitta sites in the plio-pleistocene palaeoenvironmental context of central italy edoardo martinetto1, adele bertini2, giorgio basilici3, angela baldanza4, roberto bizzarri4, marco cherin4, sergio gentili5 & maria rita pontini6 1 dipartimento di scienze della terra, università degli studi di torino, torino, italy 2 dipartimento di scienze della terra, università degli studi di firenze, firenze, italy 3 geoscience institute, state university of campinas, campinas, brazil 4 dipartimento di fisica e geologia, università degli studi di perugia, perugia, italy 5 centro di ateneo per i musei scientifici, università degli studi di perugia, perugia, italy 6 via p. nenni 4, chiusi, italy corresponding author: e. martinetto <edoardo.martinetto@unito.it> abstract: dunarobba and pietrafitta are two outstanding fossil sites, which provide us with a glimpse on central italian palaeoenvironments during two different time spans. the still poorly dated dunarobba succession is framed, mainly on the basis of continental mollusc biochronology, within the piacenzian-gelasian interval, whereas the pietrafitta one is reliably dated to the calabrian thanks to vertebrate biochronology. here we add several new palaeobotanical data for the two sites and we provide for the first time an overview of the stratigraphic, sedimentological, palaeontological and palaeoenvironmental results so-far obtained. we also review the palaeobotanical evidence concerning the neighbouring sites of cava toppetti i/ii, fosso bianco, torre picchio and villa san faustino. on the basis of the available datasets we conclude that the dunarobba fossil forest, with several large conifer trunks in upright position, was produced by an ancient swamp vegetation dominated by glyptostrobus europaeus, and including few other woody (alnus, cephalanthus, cornus) and herbaceous (carex, cladium, schoenoplectus) plants. rich water-transported fruit and seed assemblages and pollen data indicate that the well-drained palaeoenvironments around the dunarobba palaeo-swamp were covered by a forest having a floristic affinity to the modern mixed mesophytic forests of east asia, as proved by the occurrence of cryptomeria, eurya, sinomenium, etc. the disappearance of the glyptostrobus swamp forest was due to the establishment of well-drained palaeoenvironmental conditions, testified by a palaeosol profile. the pietrafitta site is characterized by a thick lignite seam, which embedded several carcasses of mammuthus meridionalis, cervids, monkeys, rhinoceroses, etc. sedimentological and palaeontological data indicate a lacustrine environment, as confirmed by newly studied fruit and seed assemblages dominated by such aquatic plants as: azolla, najas, nymphaea, potamogeton, etc. the pollen assemblage, studied in the 1960s-1970s, is still rich in exotic elements, and allows us to reconstruct a humid deciduous broadleaved forest, with a relevant subdivision of a bottom unit rich in taxodium type pollen, and a top unit, lacking this pollen type and including all the lignite seam. keywords: palaeobotany, palynology, sedimentology, local palaeovegetation, biochronology, pliocene, pleistocene, central italy. 1. introduction the pliocene-early pleistocene terrestrial palaeoflora of central italy is documented by both palynomorphs (e.g. lona & bertoldi, 1972; follieri, 1977; bertini, 2003, 2010, 2013; sadori et al., 2010; magri & palombo, 2013) and macroremains (e.g. fischer & butzmann, 2000; martinetto, 2001; teodoridis & gregor, 2001; girotti et al., 2003) from several fluvial and/or lacustrine sedimentary basins bordered by the northern apennine ridges (fig. 1). the present paper is aimed at providing an updated overview of the palaeofloral data available for plant-bearing sites in the tiberino basin (fig. 1), with special focus on the dunarobba and pietrafitta sites. actually, the deposits of this last site are generally assigned to a minor basin, the tavernellepietrafitta basin, that is considered as partly independent from the tiberino basin (see below). the occasion of this paper was suitable for the compilation and critical revision of the most relevant palaeontological, stratigraphic and sedimentological data produced in the last thirty years. 2. geological setting during the pliocene and the pleistocene, central italy was characterized by nw-se trending extensional basins, roughly parallel to the uplift of the apennine chain, which hosted marine and/or continental environments (fig. 1) (e.g. barchi et al., 1991; martini & sagri, 1993). the area surrounding the town of perugia mainly coincided with two large structures: the tiberino basin to the east, and the south valdichiana basin, to the west, respectively associated with two major depositional settings, continental to the east and mainly marine to the west. the array of environments alternating through time and space is likely to return a fairly complex stratigraphic framework, still under definition (fig. 2). three depositional cycles, respectively early-late pliocene, late pliocene-early pleistocene and middlelate pleistocene in age, have been described. the pliocene-pleistocene tiberino basin (fig. 1) was a subsiding, tilting extensional basin situated on the western edge of the northern apennine chain (ambrosetti et al., 1995a). the basin stretches for 125 km in nw-se direction, with a width of up to 20 km (ambrosetti et al., 1995a). across 19th and 20th centuries, a main coarsening upward sedimentary succession was described and associated with the fill up of a wide lake (the "tiberino lake": lotti, 1917, 1926). the bottom of this succession is made up by clay, passing to sand and gravel at the top, locally interbedded with calcareous tufa and carbonate sand (verri, 1879, 1901; verducci, 1959; jacobacci et al., 1970; conti & girotti, 1978; ambrosetti et al., 1987a). currently, four main areas, each one with its own history and sedimentary sequence, are recognized: a) north tiber valley, b) perugia-magione and tavernelle-pietrafitta minor basins, c) umbra valley, and d) south tiber valley (fig. 1). both unconformity-bounded units (synthems) and lithostratigraphic units have been used in the literature. lower pleistocene deposits crop out in the middle (magione and ponte san giovanni units, solfagnano synthem) and northern part (fighille synthem) of the tiber valley, from città di castello to deruta (fig. 2; pazzaglia, 2007; pialli et al., 2009; plesi et al., 2010; argenti et al., 2013). middle-upper pleistocene alluvial fan, fluvial and/or lacustrine sandy and/or gravely deposits crop out throughout the tiber valley. in the north tiber valley (melelli et al., 2010), the complex geological dynamics determined the formation of several subbasins (fig. 1). the eastern branch of the tiberino basin (umbra valley) mainly developed as an endorheic, isolated basin from the pliocene to the holocene, and two main depositional sequences, with alternating alluvial fan and lacustrine/swamp deposits, have been recognized (coltorti & pieruccini, 1997; regione umbria, 2005). the lower cycle (morgnano synthem: fig. 2), pliocene in age, holds the morgnano local vertebrate fauna (pantanelli, 1886; capellini, 1888; cappuccino et al., 2006), assigned to the triversa faunal unit, and is partially coeval with the lower part of the fosso bianco unit. the upper cycle (valle umbra synthem: fig. 2) had been usually dated to the early pleistocene (esu & girotti, 1974, 1991; coltorti & pieruccini, 1997; regione umbria, 2005), until palaeomagnetic data allowed extending it to the middle pleistocene, at least in the bevagna area (bizzarri et al., 2011). 2.1. the south tiberino basin the south tiberino basin (fig. 1) largely corresponds to the present-day south tiber valley. basilici (1992, 1995, 1997, 2000a, b) and ambrosetti et al. (1995a, b) distinguished four informal lithostratigraphic units (fig. 2). fosso bianco unit (fbu) this unit was mainly associated to a deep lacustrine environment with prevailing clay sedimentation. at the edge of the basin, clayey silt alternated to wavyor cross-laminated silty martinetto e. et al. 30 fig. 1 simplified geo-structural scheme for northern apennine basins, evidencing the tiberino basin. to the right, location of plantbearing sites treated in this paper within the plio-pleistocene tiberino basin in central italy. 31 plant record of dunarobba and pietrafitta sites sand laminae, parallel-laminated silty clay, lignitebearing clay deposits, and lenticular sand bodies crop out (basilici, 1992, 1997; ambrosetti et al., 1995a, b). they are interpreted as lower-shoreface deposits, marshy lacustrine shore deposits, and gilbert-type delta deposits, respectively (ambrosetti et al., 1995a, b; basilici, 1997). according to magnetostratigraphy, carried out in cava toppetti i and fosso bianco main sections, a piacenzian-gelasian age was inferred (ambrosetti et al., 1995b; abbazzi et al., 1997). ponte naja unit this unit was described only in the todi area, where it is probably heteropic to the uppermost part of the fbu, although the stratigraphic contact was never recognized in outcrops, in particular in the cava toppeti ii site, where this unit was best exposed during the 1990s. several faults, indeed, affect the contact between the two units throughout the todi hill (basilici, 1992; brozzetti & basilici, 1998). the ponte naja unit unit is associated to the distal or middle-distal end of an alluvial fan under humid climate, dominated by unchannelized flows (basilici, 1992, 1995). the vertebrate fossil record allows attribution to the villafranchian mammal age (coste san giacomo faunal unit: abbazzi et al., 1997). santa maria di ciciliano unit this unit unconformably overlies the ponte naja unit (close to the town of todi) and the fosso bianco unit (between todi and terni). it is mainly represented by up to 30 m thick sandy beds, interpreted as high-sinuosity river channels, alternated to massive or poorly laminated clay deposits with palaeosols, attributed to a floodplain. in this well-developed alluvial plain environment, deposits associated to crevasse-splays, small ponds, and carbonate sedimentation ponds, rich in characeae, were also documented (basilici, 1992, 1997, 2000a). three sites (pantalla, torre picchio, villa san faustino: fig. 2) yielded late villafranchian vertebrate fossil faunas (from the tasso faunal unit to the farneta faunal unit: ambrosetti et al., 1995a; sardella et al., 1995; gentili et al., 1997; petronio et al., 2002; girotti et al., 2003; argenti, 2004; cherin et al., 2014), that provided evidence for an early pleistocene age of the santa maria di ciciliano unit. acquasparta unit this unit crops out mainly in the area of acquasparta, where it overlays the santa maria di ciciliano unit with a concordant but sharp contact. the aquasparta unit consists of silty limestone and travertine deposits, formed in a lake or marsh, sometimes indicating emergence conditions. the unit was hypothetically referred to the lower-middle pleistocene boundary or to the base of the middle pleistocene (ambrosetti et al., 1995a). fig. 2 synthesis of the stratigraphic schemes for pliocene and pleistocene deposits throughout the south valdichiana basin and the tiberino basin. see fig. 1 for location of basins and main plant-bearing sections. 2.2. the tavernelle-pietrafitta basin and the lignites of pietrafitta the fossil-bearing lignites of pietrafitta belong to the sedimentary succession of the tavernelle-pietrafitta basin, in the upper valley of the nestore river (fig. 1). the basin extends in sw-ne direction for about 12 km, reaching a maximum width of about 5 km. the basins of tavernelle-pietrafitta and perugia-magione (fig. 1) originated as minor intermountain basins, and presumably became part of a lateral branch of the main tiberino basin during the early pleistocene (pazzaglia, 2007; bizzarri et al., 2008; cherin et al., 2012; argenti et al., 2013; pazzaglia et al., 2013). during the early pleistocene (and possibly the late pliocene), they underwent alternatively lacustrine/palustrine and alluvial plain conditions (conti & girotti, 1978; conti & esu, 1981; ambrosetti et al., 1987a, 1989). the lignites of pietrafitta have been included in the tiberino supersynthem and particularly in the nestore synthem (carg project f. 310 “passignano sul trasimeno”: argenti et al., 2013). the nestore synthem (fig. 2) rests unconformably on the pre-pliocene substrate and is unconformably covered by recent alluvial and/or colluvial deposits. it has been divided into two subsynthems: the lowermost tavernelle subsynthem and the uppermost pietrafitta subsynthem (fig. 2). the tavernelle subsynthem crops out in the whole area pertaining to the nestore synthem. lithologies vary from clay/silt to calcareous silts, sands and gravels/ conglomerates. two heteropic units (fig. 2) are recognized: the fosso cigne unit, presumably deposited in a piedmont environment, and the fontignano unit, which is related to a lacustrine and/or marshy depositional environment (pazzaglia, 2007; argenti et al., 2013). the pietrafitta subsynthem (fig. 2), which includes the fossilbearing deposit described in this paper (see below), cropped out in the area affected by the extraction of lignite, near the homonymous village in the municipality of piegaro. 3. material and methods the present paper contains, on one hand, an assemblage of dispersed information on materials treated in several previous works. on the other hand, a quantity of new data is used here to provide a more extensive overview of the history, the fossil biota, the palaeoenvironment and the palaeoecology, especially of the dunarobba and pietrafitta fossil sites. the presentation of the methods mostly concerns this last data set, which includes palynological and palaeocarpological analyses, vegetation and palaeoclimatic analyses, sedimentological analyses, as well as information on the history of the discovery and preservation of the fossil sites. 3.1. sedimentology and palaeopedology data were extracted from cores and outcrops. several exposed sections, never thicker than 10 m, have been measured and described according to the facies analysis and palaeopedological methods, including description of colour, pedological structures, horizons, and biogenic features (hodgson, 1978; catt, 1990; birkeland, 1999; retallack, 2001). samples from a palaeosol profile were collected for laboratory analyses, which concerned grain size and x-ray fluorescence analyses, to determinate textural and geochemical features, respectively. 3.2. palynology a critical review of the floristic and vegetational evidence from several pollen sites has been carried out in order to summarize and update the interpretation of the main palaeonvironmental and climatic changes at the plio-pleistocene transition in terrestrial settings around the 42° latitude and 12° longitude in central italy. the palynological documentation for the tiberino basin was provided by the dunarobba s2 core and by the following outcropping sections: dunarobba trunk and dunarobba "nuova cava fornaci briziarelli marsciano" (simonetti, 1998), fosso bianco, cava toppetti i, cava toppetti ii (abbazzi et al., 1997; pontini, 1997; pontini & bertini, 2000; pontini et al., 2002). all samples collected from previous sites were processed according to a standard procedure used at the earth sciences palynological laboratory of florence (modified from guillet & planchais 1969 and cour, 1974). for each sample at least 100 pollen grains were counted besides the dominant taxon. details on pollen counts and number of identified taxa are specified below for each section. data have been plotted in summary palynological diagrams where pollen taxa are organised into nine palyno-groups (appendix 1) on the basis of the ecological and climatic requirements of their present correlatives. early palynological studies carried out on dunarobba (ambrosetti et al., 1995b), pietrafitta (ricciardi, 1961; paganelli & solazzi, 1962; lona & bertoldi, 1972) and bastardo (gemina, 1962) deposits were also taken in account for the discussion. a floral list has been compiled on the basis of available data from cava toppetti i, cava toppetti ii, three dunarobba sections (i.e. s2 core, trunk section and "nuova cava fornaci briziarelli marsciano" section), fosso bianco and pietrafitta (appendix 2). 3.3. palaeocarpological analyses for the preparation of this work we re-examined all the carpological material from dunarobba and pietrafitta sites, which had been prepared and analysed (sometimes only preliminarily) by martinetto (1994, 1996, 2000, 2001) and pauselli (2003). most of the studied fruit and seed material is stored in the cenofita collection at the earth sciences department of turin, apart the samples df5 and df6, stored at the physics and geology department of perugia. the sediment processing and fruit and seed extraction was similar for all samples, and followed the method described by basilici et al. (1997). only two dunarobba samples (dc1a, dc1b) were prepared in the field, because of the large volume of sediment analysed. the abundance of carpological remains was counted or estimated (most frequent ones) for all sediment samples, and new comprehensive lists of plant taxa, with updated nomenclature, were compiled for dunarobba (tabs. 1-2) and pietrafitta (tab. 3). taxa records from these two sites, which are reported in pre martinetto e. et al. 32 vious papers (martinetto, 1994, 1996, 2000, 2001; pauselli, 2003) but are not confirmed here, have to be considered erroneous. 3.4. vegetation and palaeoclimate analysis an elementary approach has been used to analyse the plant macrofossil assemblages following the indications of wolfe (1971), already applied by martinetto (1995) to some italian pliocene plant assemblages. this approach implies to compare the floristic composition of a vegetation type reconstructed on the basis of a fossil plant assemblage with the modern vegetation types, and pinpoints those ones which have the most similar floristic composition, indicated as the best vegetation analogs. climatic data from the modern areas which host the best vegetation analogs are used to infer the palaeoclimatic conditions. in order to check the values of mean annual temperature obtained from the best vegetation analogs, a comparison has been carried out with data provided by grimm & denk (2012) for individual plant taxa. for the vegetational and climatic interpretation of pollen records, the principles indicated by bertini (2001, 2010, 2013) have been followed. however, in this work we newly apply the köppen-geiger classification for the definition of climate types (kottek et al., 2006). the somehow ambiguous term "subtropical" is used here with special reference to the southernmost part of the c climate belt of the northern hemisphere (comprised within the warm temperate climate according to kottek et al., 2006). in this sense the "humid subtropical" climate and vegetation today is mainly found in southern north america and southern east asia. 4. pollen and carpological studies in the plio-pleistocene of the tiberino basin pollen analyses were carried out in the studied area since the 1960s, with focus on lignite-bearing successions (ricciardi, 1961; gemina, 1962; paganelli & solazzi, 1962; lona & bertoldi, 1972). additionally, follieri (1977) analysed sediment samples from monte santo (near todi) and santa maria di ciciliano. she found that at monte santo taxodium type (that includes also glyptostrobus) and nyssa were well represented, and accompanyied by dacrydium, podocarpus, sciadopitys, sequoia, keteleeria, engelhardia, rhus, etc. with low frequencies were also present: carya, pterocarya, quercus, zelkova, ulmus, etc. later on abbazzi et al. (1997), pontini (1997) and pontini & bertini (2000) studied a few sections of the south tiberino basin, as specified below. the pollen analyses permitted the collection of rich palaeofloral data (see appendix 2). the occurrence of several genera, such as artemisia and other asteraceae, ephedra, cedrus, nyssa, sciadopitys and betula, is not documented by other plant remains. in several cases the pollen taxa are also documented by carpological material (martinetto, 1994, 1996, 2001), e.g., alnus, fagus, picea, potamogeton, sparganium, “taxodiaceae”, tsuga. fruits and seeds also provide the documentation of several taxa not represented by pollen, such as entomophilous trees, climbers and shrubs (e.g. lauraceae, menispermaceae, sabiaceae, theaceae) or herbs with generalized pollen morphology (e.g. cyperaceae). in two sites (torre picchio and villa san faustino) the analyses have been carried out on fruits and seeds alone. in this paragraph we summarize results of previous palaeobotanical investigations for the main studied sites (fig. 1), apart from dunarobba and pietrafitta which will be treated in detail below. 4.1. cava toppetti i section in this 70 m thick section, assigned to the piacenzian/gelasian transition (ca. 2.8 2.2 ma) (fig. 2; pontini, 1997; pontini et al., 2002), 15 pollen samples were collected, 7274 palynomorphs counted and 81 taxa identified. pollen assemblages (fig. 3) are dominated by arboreal elements, especially pinus; its high occurrence (never below 30%) has been linked to taphonomic biases (over-representation) because of the palaeonvironmental context associated to a deep-water lake system. along the pollen diagram the curve of taxodium type always exhibits lower percentages with respect to those of pinus and other bisaccate pinaceae, and the same occurs for deciduous broad-leaved forest elements (e.g. quercus, juglandaceae, carpinus, ulmus, tilia, acer). mediterranean elements are present with quercus ilex type, olea and pistacia. from about 40 m, in correspondence of the top of the gauss chron (pontini et al., fig. 3 summary pollen diagram of the cava toppetti i section, fosso bianco unit (modified from pontini et al., 2002). sediment grain size: c, clay; s, silt; vf, very fine sand. 33 plant record of dunarobba and pietrafitta sites 2002), an increase of herbs (mainly amaranthaceae) is evident. a following rise, at about 50 m, of both taxodium type and deciduous broad-leaved forest elements occurs, before a new expansion of bisaccate pinaceae at about 66 m (fig. 3). carpological material was collected by martinetto (2001) from the top of this section, characterised by a slump deposit, which does not allow a precise dating of the plant-bearing layer. few woody taxa so-far reported (martinetto, 1996, 2001) indicate a plant assemblage of "subtropical" humid climate: ficus potentilloides, liquidambar cf. europaea, pseudotsuga sp., sequoia abietina, symplocos casparyi, toddalia latisiliquata, toddalia rhenana. 4.2. fosso bianco section integrated palynological and stratigraphical data (sardella et al., 1995; pontini, 1997, ciangherotti et al., 1998; pontini & bertini, 2000; napoleone et al., 2003) permit to frame the fosso bianco succession into the gelasian interval between the 102 and 82 isotopic stages (i.e. within ca. 2.5 and 2.2 ma), which also comprehends the tiglian of north-west europe (zagwijn, 1963; 1974; 1996; cohen & gibbard, 2011). 56 samples were collected for pollen analysis; for each sample at least 100 pollen grains were counted besides the dominant taxon, nearly always exceeding 200 pollen grains. 17.752 palynomorphs (pollen grains and spores) were counted and 86 taxa identified. reworked palynomorphs from meso-cenozoic sediments are frequent. the pollen flora is dominated by arboreal pollen grains, principally taxodium type, followed by pinus and quercus. high percentages of abies and picea are found especially in the upper part. herbs and shrubs (e.g. poaceae, amaranthaceae, ephedra, artemisia and other asteraceae) are constantly present but generally below 30%. four main pollen zones (i-iv) (fig. 4) have been described by pontini (1997) and pontini & bertini (2000). zone i (0 m to 10.5 m). taxodium type and pinus dominate the pollen spectra. deciduous forest elements are well represented especially by quercus accompanied by ulmus; carya, pterocarya, carpinus, liquidambar and acer follow. ilex is present up to 1.5%. herbs, decidedly subordinated in comparison to arboreal elements, are principally represented by poaceae, ericaceae, amaranthaceae and asteraceae (included artemisia). the climate of zone i was definitely of c type (warm temperate sensu kottek et al., 2006) and the abundance of pollen of glyptostrobus and/or taxodium (both genera produce pollen of the taxodium type) suggests a humid "subtropical" character. the transition to zone ii is marked by the decrease of taxodium type and other “taxodiaceae”; at the same time abies, pinus haploxylon type and cathaya slightly increase. zone ii (10.5 m to 26 m). it contains a significant amount of deciduous forest elements, whereas “taxodiaceae” are scanty. at the same time herbs, including steppe elements (poaceae, amaranthaceae, asteraceae, artemisia and ephedra), show successive expansions (up to ca 30%). between the two major herbaceous expansions, respectively at 19.5 m and 24 m, a significant increase of deciduous forest elements is recorded, with a peak of quercus preceding an expansion of altitudinal coniferous trees (principally picea). the picea acme phase coincides with the major event of sudden and drastic decrease of “taxodiaceae” throughout the section, also corresponding to a significant frequency decrease of deciduous broad-leaved forest elements, cathaya and pinus haploxylon type. for zone ii a prevailing c type (warm temperate sensu kottek et al., 2006) of climate can be reconstructed, possibly tending to a d snow climate during the picea acme phase. zone iii (26 m to 65 m). the pollen assemblage of this zone is rather uniform from the bottom to the top, and is characterized by several elements which disappear from europe during the plio-pleistocene, e.g.: “taxodiaceae”, carya, pterocarya, liquidambar, nyssa, myrica, distylium, engelhardia, cf. panax and symplocos. the climate can definitely be referred to the c type (warm temperate sensu kottek et al., 2006), with a humid "subtropical" character. the changes in abundances of taxodium type and pinus pointed out several sub-phases which probably related to both climatic and local palaeoenvironmental (lake level fluctuations) changes as a consequence of regional to global climate changes. herbs (e.g. asteraceae, amaranthaceae, poaceae, brassicaceae, thalictrum, cyperaceae), with fig. 4 summary pollen diagram of the fosso bianco section, fosso bianco unit (modified from pontini &m bertini, 2000). sediment grain size: c, clay; g, gravel. martinetto e. et al. 34 steppe elements never above 1.5%, are in lower percentages with respect to the zone ii. zone iv (65 m to 86 m) is characterized by a drastic reduction of “taxodiaceae”, the absence of both ilex and ericaceae and a significant increase of the altitudinal arboreal elements. deciduous elements are abundant (especially quercus); they show two main phases of increase opposite to decreases of picea and herbs. a small peak of steppe elements is apparent in the middle of this zone. the climate of zone iv can be still mainly referred to the c type (warm temperate sensu kottek et al., 2006), but the record of boreal conifers (picea) and steppe elements (artemisia) suggests a tendency to the d and possibly b climates. throughout the fosso bianco section, the pollen record suggests repeated fluctuations in the plant assemblages, as shown in fig. 4, which can be evaluated according to glacial/interglacial cycles and regional to local palaeoenvironmental changes. the vegetation is characterized, especially during the warmer phases, by several elements which disappear from europe during the plio-pleistocene (e.g. “taxodiaceae”, carya, pterocarya, liquidambar, nyssa, myrica, distylium, engelhardia, cf. panax and symplocos). the major declines of thermophilous arboreal elements, including taxodium type, and the simultaneous picea acme testify a consistent decrease in temperature during glacial phases. colder but still humid conditions, possibly tending to the d type snow climates (kottek et al., 2006), are indicated by migration of picea to lower altitudes, also penetrating the vegetation along the coastline, as attested by the observation (pontini, 1997) of some pinaceous cones in silty strata, at the top of the section. expansions of herbs (including artemisia), especially during pollen zones ii and iv, also prove a decrease of humidity, probably corresponding to the glacial acme. these extreme climatic conditions determined a strong reduction of swampy vegetation under the influence of temperature and humidity lowering. probably both climatic parameters had a role on fluctuations of the local edaphic moisture and the lake level. still in correspondence of pollen zones ii and iv, significant increases of deciduous broad-leaved forest elements are detected, which support climate amelioration phases, within a dominant c type climate (warm temperate sensu kottek et al., 2006). however, “taxodiaceae” stay in low proportions; in fact better edaphic conditions for the development of glyptostrobus/taxodium stands were only established during the long "subtropical" and humid phase of zone iii. this apparently long interval of stable climate conditions was tentatively related to the period of low amplitude variations occurring between the 96 and 86 isotopic stages (pontini, 1997). overlying cycles (zone iv) were referred to the 86 to 82 isotopic stages and the underlying ones (zones i and ii) to the stages 100 to 96. palynological and litho-sedimentological data suggest a quite diversified sedimentation rate, along the section. in particular, in correspondence of zone iv (fig. 4), the occurrence of the 40 kyr timescale in the glacial/ interglacial cycles, approximately every 6 m, allowed to estimate a sedimentation rate of ca. 14 cm/kyr (pontini, 1997). 4.3. cava toppetti ii section in this 150 m thick section (fig. 5) fossil vertebrate remains were recovered and assigned to the sénèze faunal unit of the french biochronology (i.e the italian coste san giacomo faunal unit., abbazzi et al., 1997), which permits to frame the succession close to 2.1 ma (bellucci et al., in press). palynological analyses were carried out on palaeosols and sheet flow deposits (clayey sandy silt) of the ponte naja unit (pontini, 1997); in some cases the palaeosol top and the bottom of the subsequent sheet flow deposit were sampled. only 16 out of the 32 collected samples yielded a sufficient amount of pollen grains and spores, thus permitting to trace pollen spectra from 8 palaeosols and 8 sheet flow deposits (fig. 5). the different proportion of pollen taxa between palaeosols (higher frequencies of herbs and pinus) and sheet flow sediments (higher frequencies of taxodium type and broad-leaved deciduous taxa) reflects apparent taphonomic biases. as a whole rich and quite diversified pollen assemblages, very similar to those from both the cava toppetti i and the fosso bianco sections, are characterized by "subtropical" to warm temperate elements (taxodium type principally, and nyssa, distylium, etc.) as well as fig. 5 summary pollen diagram of cava toppetti ii section, ponte naja unit (modified from abbazzi et al., 1997). sediment grain size: c, clay; m, medium sand; g, gravel. 35 plant record of dunarobba and pietrafitta sites broad-laved deciduous elements (such as quercus, carpinus, ulmus, pterocarya, araliaceae panax type) typical of warm temperate climate (kottek et al., 2006). forest elements (broad-leaved deciduous dicotylendons plus taxodium type) and herbs (especially asteraceae cichoroideae) show opposite phases of increase, over an interval of ca. 100 kyr, i.e the estimated time interval of deposition of the alluvial fan succession (basilici, 1995). steppe taxa (such as artemisia and ephedra) are not abundant during the dominant open vegetation phases. one of the sheet flow deposits, in the middle of the section, also yielded a rather rich carpoflora (martinetto, 2001). woody taxa so-far reported indicate a "subtropical" humid climate: cephalotaxus sp., mahonia staphyleaeformis, magnolia cor, sequoia abietina, sinomenuim cantalense, symplocos casparyi, toddalia latisiliquata. 4.4. torre picchio section this site of the south tiber valley, rich in fossils of plants and animals, is assigned to the gelasian/calabrian transition (ca. 2.01.5 ma) by girotti et al. (2003), who sampled and described a diverse fruit and seed association. it is characterised by the substantial lack of humid "subtropical" elements, and certainly reflects a palaeoflora which is significantly different from those of the older deposits of cava toppetti i and ii. the palaeoflora of torre picchio was still significantly different from the present flora of central italy, as evidenced by abundant remains of "exotic" trees, such as liquidambar, liriodendron and pterocarya, and also by fruits of extinct herbaceous species, such as melissa elegans and schoenoplectus cf. lacustroides. this plant assemblage definitely indicates a warm temperate climate (kottek et al., 2006). 4.5. villa san faustino section a few carpological remains from this deposit, assigned to the gelasian/calabrian transition (ca. 2.0-1.5 ma: ambrosetti et al., 1995a), were listed by martinetto (1996, 2001). the palaeofloral association of villa san faustino is significant from the palaeoclimatic point of view because of the common occurrence of leaves and other macroremains of abies and picea. these genera are mainly linked to snow climates (kottek et al., 2006), and the occurrence of macrofossils testify for their growth at low altitudes, thus indicating colder climatic conditions in comparison to the older palaeofloras of cava toppetti i-ii. however, the presence of carpinus, ostrya and thymelaea excludes a snow climate (kottek et al., 2006), and would suggest a cold type of c climate, similar to the modern one of the areas where abies and ostrya grow together in the mediterranean basin (e.g. southern apennines). the possible framing of the villa san faustino and torre picchio palaeofloras within the early pleistocene climate dynamics will be discussed below (see 7.2.). 5. the dunarobba site the dunarobba fossil forest (df), in the territory of avigliano umbro (province of terni, umbria region), represents a peculiar palaeontological heritage because of the excellently preserved remains of an in situ forest (fig. 6), developed along the swampy lacustrine margin of the tiberino basin (ambrosetti et al., 1995a). in the df about 70 huge arboreal specimens (trees) in growth position have been so-far observed (ambrosetti et al., 1995b; baldanza et al., 2009). the trunk remains are buried by silty and clayey sediments, with minor lignite and fine sand, belonging to the fosso bianco unit, whose sedimentological features fig. 6 two panoramic views of the dunarobba fossil forest at the end of the 1980s (courtesy of p. ambrosetti, c. benigni). martinetto e. et al. 36 are described below. the observations carried out on several small oucropping sections (fig. 7) allowed us to reconstruct a ca. 30 m thick succession. in addition, a drilling project realised during the years 1992-1995 (ambrosetti et al., 1987a) furnished the continuous, ca. 110 m thick, s1 core (fig. 8). a shorther core, s2, correlates to the upper part of the s1 core. the intergration of data from cores and outcrops let us to build up the dunarobba fossil forest synthethic log (fig. 8). most of the palaeobotanical studies on the dunarobba fossil forest (biondi & brugiapaglia, 1991; meneghini & paganelli, 1994; martinetto, 1996; simonetti, 1998; pauselli, 2003) were carried out on short sections, when the outcrop conditions were already deteriorated, so that a precise correlation of these sections to the dunarobba fossil forest synthethic log (fig. 8) is not easy. however, thanks to our observations during the 1980s, in good outcrop conditions, we provide here for the first time a syntetic correlation scheme of seven main sections (s1 core, s2 core, road, lignite, forest, trunk and palaeosol: fig. 8). thus, all the palaeobotanical data, both published by other authors and collected by us, can be referred with certainty to one of these fig. 8 the reconstructed dunarobba fossil forest synthethic log (to the left) showing the approximate stratigraphic position of seven main sections: s1 core, s2 core, road, lignite, forest, trunk and palaeosol. the trunks of the dunarobba fossil forest are found within interbedded sand and mud, for a thickness of ca. 50 m. notice the position of pollen and carpological samples. sediment grain size: c, clay; s, silt; vf, very fine sand. 37 plant record of dunarobba and pietrafitta sites fig. 7 satellite image of the dunarobba site, downloaded from googlemaps on may 25th, 2014. the location of all sections mentioned in this work is shown. dc, dunarobba "new quarry" section; dw, dunarobba west section. sections. we still need to point out that, about 700 m to the nw of the forest section, another outcrop was studied (fig. 9). this was named by basilici (1992) as "dunarobba cava nuova" ("new quarry"), and by simonetti (1998) as "nuova cava fornaci briziarelli marsciano". in this work it is indicated by the abbreviation dc (fig. 7), and it is re-examined only from the palaeobotanical point of view. in fact, it provided rich macrofloral data, useful for a better understanding of the dunarobba fossil forest palaeovegetational context. the correlation of the dunarobba fossil forest synthethic log to the dc section was not possible with stratigraphic methods, and will be discussed below on the basis of palaeobotanical data. currently, the dc section is no more exposed, but a 50 m thick clayey and silty succession, still pertaining to the fosso bianco unit, crops out in a fresh section opened in the years 2010s (dunarobba west, dw), 600 m to the west of the forest section (fig. 7). a new sampling was carried out in the dw section by two of the present authors (baldanza, bizarri) with the aim to investigate the ostracod and mollusc content and the formation of siderite nodules. 5.1. history of the discovery and fossil heritage preservation since its first discovery, the df had to wait another 300 years to be rediscovered again: in fact the first reports date back to the early decades of the 16th century, to the work of the naturalist, and founder of the accademia dei lincei, federico cesi (biondi, 1984). this researcher invited the academic francesco stelluti to investigate findings of arboreal specimens in the area of the df, and the latter reported his observations in the work "trattato del legno fossile minerale nuovamente scoperto nel quale brevemente si accenna la varia et mutabil natura di detto legno", published in 1637. stelluti, as a scientist, discussed the possible hypotheses on the formation of such wood on the basis of the evidence collected: “…within the territory of todi and acquasparta there are four sites where this species of wood, which presents a large similarity with the cedar that is born in mauritania, in atlas mountain (...), does occur. the formation of this wood is not from seed, or root of the plant, but solely by a kind of earth which looks much alike to the chalk, which gradually turns into wood .... and this, i believe, with the help of some heat from subterranean fires, that occur in those places. they grow underground, very often sending out a smoke, and sometimes flames, and especially during rainy days, with the help of sulfuric waters". the beautiful drawings made by stelluti during his research and observation of the woods (the "metallofiti" of cesi), were collected and stored, after cesi’s death in 1630, by cassiano dal pozzo (another member of the accademia dei lincei) in his "paper museum". the collection was acquired, over a century later, by king george iii of england and is currently housed in windsor castle. scott & freedberg (2000) published a selection of drawings concerning fossilized woods and other geological specimens. after these studies, the fossil wood in the region attracted foreign visitors to admire this wonder, especially after the napoleonic invasion, and visits of men of culture and science, or even just curious people, became more frequent. the wooden remains were wellknown to local people, who, after surveys and excavations to find possible lignite seams, had to fight with the upright logs which prevented the digging of tunnels (cerquaglia, 1996). mining activities characterized the period following the first world war, providing work and a source of albeit minimal wealth for the miners. at the turn of 1950s and 1960s the mining technique changed by opening large open-cast mines, and also the material exploited changed, no more lignite but clay for the fig. 9 the dunarobba "new quarry" section (dc, see location in fig. 7), years 1990s. the asterisk indicates the sands from which sample dc1a was collected. the arrow indicates the thin lignite bed dc3. martinetto e. et al. 38 heavy clay industry. in 1986, with the progress of the work in the quarry of the briziarelli marsciano brick factory, large trunks in life position came to light, reaching heights of over eight meters. since the discovery, the operators of the archaeological survey of umbria carried out activities to preserve the fossils. after the imposition of a protection bond, according to the law, a first monitoring system has been activated in the 1990s (still in use), for the automated registration of changes in the environment as well as on some logs (vergoni, 2000). the main requirement was, and is, to limit the damage caused by atmospheric and biological agents to the wood of the trunks, so that a climatic maxi-chamber was built around a group of specimens (named 25m), and fig. 10 dunarobba section, interbedded sand and mud intervals. (a) laminated muddy sand showing structures produced by wave motion (circled in picture). (b) wave ripples can be observed on the bedding surfaces, indicating the role of waves as transport and sedimentation agent on the wetland border where the dunarobba fossil forest was located. pencil: 0.145 m. (c) deformed sandy laminae in mudstone. the deformation is likely due to bioturbation by roots. coin: 24 mm. (d) desiccation cracks (arrows) filled by bluish gray mud in wetland lake border subjected to frequent emersions. coin: 24 mm. (e) slickensides indicate common variation of water content in sediment probably linked to seasonal variations of the lake level. coin: 23 mm. (f) freshwater isopod (arrow); these fossils, as also freshwater fishes, crabs and gastropods, suggest at least periodical subaqueous conditions. coin: 23 mm. 39 plant record of dunarobba and pietrafitta sites natural resin (colophony) was employed for the experimental treatment of some trunks. 5.2. sedimentology and depositional palaeoenvironment the sedimentary succession of the df, which unconformably overlies eoceneoligocene clayey marl (scaglia cinerea fm.), is 131 m thick and has been divided into five intervals (ambrosetti et al., 1995b; basilici, 1997, 2000b): 0.4 m of lignite, 76 m of laminated mud, 51 m of interbedded sand and mud, a 2.35 m thick palaeosol profile, and more than 1.5 m of sandy mud (fig. 8). the interbedded sand and mud, which contains the trunks of the fossil forest, as well as the palaeosol profile and the sandy mud, are described and interpreted with the aim to understand the conditions of growth, death and preservation of the trunks. above the interval of 0.4 m of lignite, deposited in a wetland environment, 76 m of laminated muds suggest a lake depositional palaeoenvironment, located below the base of the wave action, where the sedimentation was controlled by low-density gravitational flows, with settling in disoxic conditions. 5.2.1. interbedded sand and mud interval the transition from laminated mud to the overlying interbedded mud and sand interval is gradual, and four lithofacies were described: sand, sandy mud, mud, and lignite (ambrosetti et al., 1995b; basilici, 1997, 2000b, 2008). the sand lithofacies is constituted of very fine-grained silty sand and finegrained sand beds. in cross-section, small bedforms display pointed crests and chevron and bundled upbuilding cross-laminations (de raaf et al., 1977) (fig. 10a); on the bed surfaces, these structures appear as symmetrical ripples with rectilinear and pointed crest (fig. 10b). the sandy mud lithofacies displays thin laminae, commonly interrupted and convoluted (fig. 10c). thin cracks, tapering downward, polygonal in shape on the depositional surface and filled of mud, are also observed (fig. 10d). the mud lithofacies is structureless, but it is characterized by isolated calcareous nodules, <1-10 mm across, siderite nodules, up to 50 mm in diameter, and slickensides (fig. 10e). fossil remains of small fishes, crabs, and aquatic isopods are present (fig. 10f). the lignite lithofacies, 0.21.5 m thick, is constituted of horizontal tree trunks and branches, and it is associated to mud beds. the outcrop conditions do not allow to well define the overall spatial relationships of these facies. however, in the upper portion of this interval sand, sandy mud and mud lithofacies are organized in a coarsening and thickening upward sequence (fig. 11). the sandy beds were deposited by traction and settling for oscillatory flows associated to unidirectional flows (combined flows). grain size and horizontal geometry of the thin laminae of finer deposits indicate that they are the product of settling in calm water conditions. lignite is interpreted as autochthonous organic deposit in a wetland. emersion evidences (desiccation cracks) and palaeopedogenic features (partial disruption of the sedimentary structures, calcareous nodules, slickensides, roots, organic concentration, tree trunks) occur in all the facies, although they prevail in mud beds. these fig. 11 palaeosol section, upper portion of the sedimentary succession of the dunarobba fossil forest. here the top of the interbedded sand and mud, drained palaeosols profiles, and sandy mud are represented in detail. sediment grain size: c, clay; vf, very fine sand; m, medium sand. martinetto e. et al. 40 structures suggest periodical emersion and pedogenesis of the depositional surface, as a consequence of seasonal lowering of the water level and establishment of draining conditions. nonetheless, the sand and mud interval lacks of clear well-defined palaeosol profiles, since the high rate of sedimentation overcomes the pedogenesis rate (kraus, 1999). overall, based on the sedimentary aspects, the succession that contains the df was interpreted (ambrosetti et al., 1995b; basilici, 1997, 2000b) as a wetland characterized by a coastal lacustrine palaeoenvironment at the margin of a large and deep lake, in which the largest part of the fosso bianco unit was deposited. in lake margins, the wave action decreases towards the coast for the influence of vegetation, that attenuates the wave energy, hinders the formation of a sandy foreshore, and promotes the deposition of mud and organic matter on the inner coastal areas (e.g. distribution of lithofacies for the lacustrine palaeoenvironment of the horton bluff formation-lower carboniferous, nova scotia: martel & gibling, 1994). the proposed lateral lithofacies model (facies tract) for the df depositional system is characterized by the progressive decreasing of the grain size and increasing of the emersion evidences towards the coast (ambrosetti et al., 1995b; basilici, 1997). 5.2.2. palaeosol profile and sandy mud the upper portion of the df sedimentary succession is formed of a 2.35 m thick palaeosol profile, overlain by a more than 1.5 m thick mud deposit (fig. 11). the lower transition of the palaeosol profile interval is gradual, whereas its upper boundary is sharp, but non erosional. bioturbation and root traces, with preserved organic matter and drab haloes, occur in all the horizons, but they are concentrated in a and bss horizons, together with charcoal. the high concentration of slickensides in a and bss horizons defines angular blocky peds, which identify a structure called mukkara (retallack, 2005). in this sense, the undulating surface of the top of the a horizon may be interpreted as gilgai superficial microrelief. high concentrations of clay, and mukkara and gilgai structures are features typical of vertisols. the palaeosol profile interval indicates an interruption of the sedimentary processes, which did not extend for more than hundred years, because low concentration of calcareous nodules (machette, 1985) and clay in b horizons, as well as absence of pedogenic structures (with the exception of mukkara), evidence poor soil development (wright, 1989). calcareous nodules, orange mottling, and clay accumulation within the palaeosol profiles are the evidences of the establishment of drained conditions that caused the extinction of the wetland where the forest lived. drained conditions cannot be attributed to climate changes, because (1) calcareous nodules are small, isolated and not abundant, differently of arid environments, (2) slickensides and clay concentration in bss and bt horizons, respectively, indicate rain precipitation, and (3) drab haloed root traces indicate temporary water stagnation. the upper sandy mud interval represents the re-establishment of the previous palaeoenvironmental conditions, related to a lacustrine margin wetland. however, in situ tree trunks were not found in this interval, and only fossil leaves and conifer shoots occur (fig. 12a). 5.2.3. changes in the sedimentary environment the sedimentary intervals described reveal a succession of events that led to the growth, death and preservation of a swamp forest. the trees lived in a wetland lacustrine margin, where high quantity of muddy and sandy sediments was constantly introduced by combined flows, generated by wave activity. cumulative palaeosols with a horizon up to 3 m thick and absence of b horizon testify for a high sedimentation rate, which prevented the formation of well-developed soil profiles (kraus, 1999). some large sub-horizontal woody axes were observed laterally to the tree trunks (fig. 12b) and interpreted as adventitious roots by ambrosetti et al. (1995b). the poorly-developed vertisol, that overlies the coastal lacustrine deposits, exhibits drained palaeoenvironmental conditions, which caused the disappearance of the wetland and the swamp forest. the high rate of sedimentation in the sand and mud interval that contains the df is due to high accommodation space creation, probably generated by tectonics. indeed, clear evidences of tectonics activity during sedimentation are provided by gilbert-type deltas in contemporaneous fig. 12 (a) glyptostrobus europaeus shoots (arrow) and seeds can be found in sandy mud above the drained palaeosol, suggesting the continued presence of this species. coin: 22 mm. (b) sub-horizontal, flattened woody axis (arrow), possibly connected to a large trunk, well above the stump base. this same structure was interpreted as an adventitious root by ambrosetti et al. (1995b). pencil: 145 mm. 41 plant record of dunarobba and pietrafitta sites deposits of the fosso bianco unit (basilici, 1997) and high frequency cycles of immature palaeosols and sheet flow deposits in a contemporaneous alluvial fan (ponte naja unit: basilici, 1995) . the successive restoration of the wetland conditions did not allow the preservation of in situ tree trunks: probably the rate of space accommodation and/or sedimentary supply were no more suitable to create conditions for the preservation of a new fossil forest. 5.3. fossil invertebrates the most common invertebrates reported from the dunarobba sections are molluscs and ostracods; apart from these, only a few insects have been studied in the forest section (principato & principato, 2000). two malacological associations were distinguished in the deposits of the forest section: 1) pulmonate gastropods, found in clays near the trunks (hydromorphic palaeosols lithofacies), which indicate a wooded environment with highly hydric soil (swamp), and 2) an association dominated by freshwater prosobranchia, which characterizes running, loosely flowing or standing waters (ambrosetti et al., 1995b; ciangherotti et al., 1998). both associations suggest a warm temperate climate. the first association shows strong affinities with pliocene mollusc associations of nw italy, france and germany; the second association includes endemic species also found in the sections (see fig. 1) of fosso bianco (fosso bianco unit) and cava toppetti i (ponte naja unit). the rich fossil snail assemblage of the forest section (fig. 7) consists of about twenty species, some of great palaeontological and biogeographical interest (manganelli et al., 1989, 1990; esu & girotti, 1991; esu et al., 1993; ambrosetti et al., 1995a; manganelli & giusti, 2000). only five species have been investigated in detail: eostrobilops aloisii manganelli, delle cave et giusti 1989, leiostyla cf. gottschicki (wenz 1922), lauria cf. cylindracea (da costa 1778), gastrocopta (albinula) acuminata (klein 1846) and g. (vertigopsis) moravica (petrbok 1959) (manganelli et al., 1989, 1990; manganelli & giusti, 2000). recently, the new species staurodon cianfanellianus manganelli, benocci, esu et giusti 2008 was described (manganelli et al., 2008). medici & gliozzi (2008) reported in the dunarobba forest section a more diversified ostracofauna with respect to cava toppetti i and fosso bianco sections, including candonidae, limnocytherinae, ilyocyprididae, cytherideinae and cyprididae. as a whole, the tiberino lake ostracod assemblages seem to be characterised by a marked endemism, particularly in the deep lacustrine facies (up to 83%) and, among the candoninae, intralacustrine speciation is recognizable for genera candona (neglecandona), sirmiella and "caspiocypris". within the dunarobba ostracod fauna, only 2 species are new (paralimnocythere n. sp. and hemicypris n. sp.) while the remaining 14 species were already known, and display a broad european distribution. the presence of cypris subglobosa sowerby 1840, and of the genus hemicypris, suggests that the tiberino lake littoral waters were warmer than the present-day lakes of central italy (medici & gliozzi, 2008). during the recent sampling of the dw section by fig. 13 glyptostrobus europaeus cone and shoot imprints highlighted by reddish minerals, sample photographed in an unmarked position of the forest section of dunarobba. coin diametre = 2 cm. fig. 14 compressed leaf of the fern osmunda from the forest section (photo o. pauselli). scale = 1 cm. martinetto e. et al. 42 a. baldanza, r. bizzarri, e. gliozzi and f. posati, some preliminary data on the ostracod assemblages have been collected. the association was exclusively made up by candonidae, including the dominating species candona neglecta sars 1887, accompanied by common caspiocypris spp., and seems to confirm the occurrence of the species flock event hypothesized by medici & gliozzi (2008). 5.4. fossil plants data on the trunks of the dunarobba forest section were collected by ambrosetti et al. (1995b). the diameter size of the trunks was measured from 1.5 to 2.5 m, and the visible height between 2 and 8 m. the trees were presumed having grown to heights of about 35 m and the older ones probably have lived for 20003000 years. thanks to the mapping of the in situ trunks of the forest section (ambrosetti et al., 1995b), a density of 43 trees/hectare was estimated. due to the rapid burial and the dysoxic environment, the wood is still perfectly preserved (mummified), with very limited mineralization in just a few specimens (scott & collinson, 2003; nowak et al., 2007); in many of the large, intact trunks original cellulose and lignin were detected (baldanza et al., 2009). several papers were devoted to dunarobba wood analyses, spacing from chemotaxonomy (staccioli et al., 1996; menchi et al., 1997; staccioli & bartolini, 1997) to mineralogy of inorganic compounds (boyce et al., 2001; staccioli et al., 2001; scott & collinson, 2003) and, finally, to the role played by organic compounds for permineralization (nowak et al., 2007). according to wood-anatomical analyses, biondi & brugiapaglia (1991, 2000) assigned all of the trunks to a single morphospecies, taxodioxylon gypsaceum (goeppert) krausel, which shows similarities to the modern wood of sequoia sempervirens. in the sediments embedding the fossil trunks several smaller plant remains have been observed: roots, woody axes, conifer shoots, leaves, small cones and tiny seeds. the conifer shoots are all of the same type and can be referred to glyptostrobus europaeus (fig. 13), observed from the bottom to the top layers of the forest section. the nearest living relative of this extinct conifer species is the east asian tree glyptostrobus pensilis. angiosperm leaves are often tightly packed and fig. 15 a) detail of the wood original color in dunarobba trunks. b-d) comparison of the same trunk fragment (from 2007 to 2009), analysed by baldanza et al. (2009), evidencing a massive loss of wooden material and the formation of dark brown ring around the mineralized area. 43 plant record of dunarobba and pietrafitta sites the morphology is difficult to be recognized. only a few compressed leaves showed significant morphological features as to be assigned to acer sp. and osmunda sp. (fig. 14). the plant remains sampled at the top of the palaeosol section (fig. 12a), in the upper sandy mud interval above the palaeosol, have been assigned to glyptostrobus europaeus (shoots with scale-like leaves and a few seeds) and to acer sp. (trilobate leaves). a still unstudied collection of leaf impressions of uncertain stratigraphic position is preserved at the reception centre of the df (centro di paleontologia vegetale), and contains interesting fern and angiosperm leaves. the macropalaoebotanical research carried out in the dunarobba sections was mainly devoted to fruit and seed analysis (palaeocarpology, see 5.4.2.). 5.4.1. wood research and preservation the finding of trunks in life position testifies that the trees underwent conservative and reducing conditions soon after death or even during life. the soft clayey sediments protected the trunks from the attacks of bacteria and fungi, also preventing the circulation of mineralizing fluids. a natural resistence of the dunarobba wood to the attacks by fungi and insects was reported by palanti et al. (2004), and the high content of cellulose (brugnoli et al., 2000) testifies for a good preservation state. moreover, the 13c and 12c isotopic composition, measured both on rings and on extracted holocellulose, evidenced many important fluctuations related to palaeoenvironmental variations (i.e. water availability and temperature). the dunarobba trees registered a progressive enrichment of 13c in the annual rings, and brugnoli et al. (2000) concluded that such isotopic variation was due to a physiological response of the trees to stressed palaeoenvironmental conditions, also responsible for a decrease in the tree growth. several papers were devoted to dunarobba wood analyses spacing from chemotaxonomy (staccioli et al., 1996; menchi et al., 1997; staccioli & bartolini, 1997) to mineralogy of inorganic components (boyce et al., 2001; staccioli et al., 2001; scott & collison, 2003) and, finally, to the role played by organic compounds for permineralization (nowak et al., 2007). recent mineralogical research (baldanza et al., 2009) assessed that exposure to the atmosphere produced a significant alteration of the wood (fig. 15). two different types of wood are identified, one suffering from an incipient mineralization with calcium carbonate, and one nonmineralized in which the original organic material is preserved. natural weathering effects, of the "once buriednow exposed" mummified trunks, are responsible for significant decay effects on the exposed trees; it was highlighted that the environmental conditions transform the iron sulfides into iron oxides and hydroxides, with production of sulfuric acid. this process of widespread alteration, with the formation of new mineral phases and their volume increase, is one of the probable causes aggravating exfoliation of the many phenomena that afflict the trunks of the df. observations carried out during the years 2007-2009 (fig. 15), on the same trunk fig. 16.compressed leaf (hamamelidaceae?) on a bedding plane of the fine sands of the dc section. scale = 1 cm. fig. 17 fossil carpological remains from the dunarobba dc section, belonging to plants which are rare in post-miocene sediments of central-eastern europe: 1) zanthoxylum ailanthiforme, seed; 2, 3) toddalia rhenana, seeds; 4) sabia europaea, fragmentary endocarp; 5) tetraclinis salicornioides, cone. scale 1 mm. martinetto e. et al. 44 fragment, evidenced a massive loss of wooden material and the formation of dark brown ring around the mineralized area. 5.4.2. palaeocarpological studies rich assemblages of fruits, seeds and related structures have been sieved out from several sediment samples of the road section, lignite section, forest section and from four layers of the adjoining dc section (figs. 7 and 8). in the forest section, three sediment samples were collected in the 1990s (labels df1-3), and partial results were already reported by martinetto (1994, 1996, 2000). this sampling phase also regarded a layer of lignite (dl1) cropping out at the entrance of the df protected area, in the lignite section (corresponding to section 3 of basilici, 1992, p. 178). another sample of consolidated sandy mud (dr1) from a lower layer of the road section was kindly provided by dr. patrizia argenti (this sample was precisely placed at the height of 20.8 cm in section 7 of basilici, 1992, p. 7). about ten years later, pauselli (2003) analysed other four samples from the forest section. the stratigraphic position of all of these samples was marked into short stratigraphic sections (1-2 m thick), which fall in the interval between 90 and 125 m of the dunarobba fossil forest synthethic log (fig. 8). the fine-scale stratigraphic correlation of the sampled layers is not easy, however dr1 is definitely the oldest sample, immediately followed by dl1, whereas the remaining samples are certainly located no more than 20 m above dl1 (fig. 8). in the dc section, field observations permitted to detect abundant wood and leaf remains (fig. 16), but only the fruits and seeds have been analysed to reconstruct the palaeoflora. four layers were sampled in the 1990s (martinetto, 1996), and precisely: sands (composite bed dc1, samples dc1a, 8 dm3 and dc1b, 20 dm3) laying 3-4 m below the base of the lignite layer dc3; sandy silt (layer and sample dc2, 4 dm3) laying 1.6 m below the base of the lignite layer dc3; lignite (layer and sample dc3, 5 dm3); lignite and poorly consolidated carbonate deposits (composite bed and sample dc4, 3 dm3), corresponding to the same layer of the dc3 sample (and part of the layer above it), in a site where its thickness was less than 10 cm. we did not consider for the present work the unpublished carpological material from dunarobba deposited by d.h. mai in the collection of the museum fuer naturkunde of berlin, because it was sampled from an uncertain stratigraphic position (year 1999, with e. martinetto). the results of palaeocarpological investigations show that the assemblages of the road, lignite and forest sections contain the same taxa as those found in the richer dc assemblages (tab. 1). all of the identified taxa (e.g., plate i) correspond to fossil species commonly found in the neogene successions of transalpine europe, and in the pliocene of northern and central italy. these data suggest that the tiberino basin area, at the time when the df grew, belonged to the same palaeofloral region as central europe, namely the "westeuropean region" of mai & walther (1988). particularly remarkable is the absence of mediterranean elements or plants indicating periodically dry conditions. an astonishing feature, in consideration of a possible early pleistocene age, is that several dunarobba taxa (fig. 17) were considered to disappear from central-eastern europe at the end of the miocene (e.g. tetraclinis salicorniodes, zanthoxylum ailanthiforme), and others at the and of the early pliocene (toddalia rhenana, sabia europaea). the meaning of their occurence in the dunarobba section will be discussed below at the light of the role of refuge area played by central italy in the pliocene-early pleistocene (martinetto, 2001). the layers of lignite and of mudstones with compressed plant macroremains (dc3, dc4 df1-6, dl1) have provided fruit and seed assemblages dominated by a few very common species (see plate i): alnus sp., carex psedocyperus, cephalanthus dorofeevi, cladium paleomariscus, glyptostrobus europaeus, schoenoplectus isolepioides, cornus aff. amomum. in accordance with what is argued elsewhere (martinetto, 1994), this lack of variety can be explained by a limited range of post-abscission dispersion, so that the fruits and seeds must belong to a few species adapted to specific soil conditions, which formed the local palaeovegetation. these fruit and seed assemblages (dc3, dc4, df1-6, dl1) were most probably generated through a simple vertical fall of the diaspores or a short lateral transport by air or water, so they can be classified as autochthonous (or hypoauthochthonous). the dr1 sample, consisting in consolidated sandy mud of the road section, differed from the others for the dominance of diaspores adapted to animal dispersal (endozoochory), and selective transport by animals is the probable cause of the peculiar composition of this species-poor assemblage, which does not allow the reconstruction of an ancient plant community. as for the two associations from silty sand layers of the "new quarry" section (dc1, dc2), a more consistent drift of fruits and seeds can be argued. these contain a mixture of hygrophilous plants (cladium, glyptostrobus, schoenoplactus, sparganium) and taxa that can be assigned to mesic palaeocommunities of well-drained soils (fagus, liriodendron, zanthoxylum), thus suggesting that the plant remains were collected from several types of mesic and wetland vegetation, and transported till to a lake-shore environment, resulting in a higher species diversity of these assemblages (tab. 2). 5.4.3. palynology at the dunarobba fossil forest site pollen analyses were carried out on 52 samples (simonetti, 1998), collected throughout the 53.5 m thick s2 core (fig. 8), which crossed the sediments of the fosso bianco unit (fig. 18). also two samples from the trunk section (figs. 7, 8) were analyzed. moreover, 7 palynological samples were collected throughout the dc section (fig. 7), which includes 10 m of clastic deposits (fig. 18) with wave-dominated coastline sands at the bottom and two meters of calcareous strata at the top (fosso bianco 45 plant record of dunarobba and pietrafitta sites unit). as a whole, rich and well preserved pollen assemblages have been detected, that provide accurate floristic and vegetational evidence. s2 core 76 taxa representatives of 49 families were identified (simonetti, 1998; appendix 2). "subtropical" to warm temperate arboreal taxa are abundant. among them, taxodium type, a typical swamp element, dominates the pollen assemblages in association with alnus, pterocarya and nyssa. some herbaceaous taxa, such as poaceae, cyperaceae, sparganium, potamogeton, were also present but never in high abundance. successive fluctuations in the percentage curves of swamp elements, as well as of pinus, possibly reflect variations of the lake water level. pollen of deciduous broadleaved mixed forest elements (e.g. quercus, ulmus, fraxinus, pterocarya, carya) is more abundant in those layers where a decrease in inundation phases was attested by sedimentological evidence (less waterlogged conditions). the origin of cathaya, pinus, and cedrus pollen is attributed to the closer middle altitude mountain belt; tsuga is not a significant component. among microthermic conifers picea is subordinated to abies; they are especially present in correspondence of the lacustrine lithofacies at the bottom of the core otherwise usually strongly reduced. the increase of cathaya, the appearance, though with scanty pollen grains, of sciadopitys and the concomitant decrease of taxodium type and of the broad-leaved mixed forest elements in the upper portion of s2 was related to a cooling trend (simonetti, 1998). if not climate-induced such change in proportion of the plant assemblages could rather be related to a major lake level increase, which in its turn determines an over-representation of bisaccate pollen grains and the flooding of the wetland vegetation. herbaceous elements, always in low quantities, consist in large part of hydrophytes such as typha latifolia, spartab. 1 list of fruit and seed taxa detected in samples of both the forest section and the new quarry (dc) section of the dunarobba site; occurrences in the road and lignite sections are also reported.the column "e/n" is referred to the nearest living relatives, e = exotic, n = native; hab = habitus: t = tree, s = shrub, h = herb, c = climber; a/h/m = aquatic, hygrophilous, mesic. the values represent the taxon's percentual frequency in each sample. martinetto e. et al. 46 plate i fossil fruits and seeds (apart tetraclinis) from the dunarobba sites (road, lignite, forest and dc sections): 1) glyptostrobus europaeus, seed; 2) tetraclinis salicornioides, shoot article with detail of the stomata (2b) at the sem; 3) cornus aff. amomum, endocarp from both sides, showing one of the 2 seed locules and internal septum (3b); 4) magnolia allasoniae, internal view of a seed; 5) sinomenium cantalense, endocarp; 6) cyclea palatinati-bavariae, endocarp fragment in two views; 7) meliosma wetteraviensis, small endocarp; 8) ficus potentilloides: 8a, endocarp morphology; 8b, detail of cells; 9) cephalanthus dorofeevi: 9a, endocarp morphology; 9b, detail of the surface with striation; 10) ampelopsis ludwigii, seed; 11, 12) cladium paleomariscus, endocarps in lateral and basal views; 13) carex pseudocyperus, utricle partly opened as to show the achene inside; 14) schoenoplectus isolepiodes, achene with two bristles. scale bar = 1 mm, when not differently indicated. 47 plant record of dunarobba and pietrafitta sites tab. 2 list of fruit and seed taxa detected only in the samples of the road and dc sections of dunarobba. see tab. 1 for explanation. martinetto e. et al. 48 fig. 18 summary pollen diagrams of three sections sampled at dunarobba, fosso bianco unit (modified from simonetti, 1998). steppe elements are represented by artemisia, but they do not figure out in the diagram due to the very low percentage. sediment grain size: c, clay; m, medium sand. 49 plant record of dunarobba and pietrafitta sites ganium, potamogeton, poaceae (p.p.). abundant spores of pteridophyta (polypodiaceae, osmundaceae) were also detected. trunk section the stratigraphically lower pollen spectrum from the trunk section is dominated by taxodium type and broad-leaved mixed forest elements, whereas pinaceae are strongly reduced. on the other hand the pinaceae are frequent in the upper pollen spectrum of this section (clay inglobing the trunk). this second spectrum shows very few non arboreal taxa, and the highest percentanges are reached by pinus (including the haploxylon type). the discrepancies detected in the two samples suggest a considerable taphonomical bias, so that the discussion of the pollen results will be mostly based on the several s2 core samples. a previous analysis by meneghini & paganelli (1994), carried out on a 350 cm thick part of the forest section, is similar to the lower spectrum of the trunk section, even if the frequent "taxodiaceae" pollen (1134%) has been mainly attributed to sequoia type. the floristic list included also some other taxa such as: sciadopitys, taxodium type, celtis, eucommia, tsuga, juglandaceae. "nuova cava fornaci briziarelli marsciano" section (dc) pinaceae are largely present with pinus reaching the maximum value of 42.5 % at ca. 4 m, in this position also cathaya shows an increase up to ca. 8%. taxodium type is constantly present with the higher values (ca. 18%) at 8.4 m. sequoia type is scanty. broad-leaved deciduous forest taxa are principally represented by quercus, which reaches a maximum (20%) at 13.3 m. ulmus, carya and pterocarya follow. alnus shows several fluctuations never depassing 5.4%. meso to microthermic conifers are usually present in low percentages (e.g. cedrus and tsuga), even if abies shows a good increase toward the top of the section at 12.8 m reaching values up to 4%. herbaceous elements are principally represented by poaceae and asteraceae. brassicaceae follow. 6. the pietrafitta fossil site 6.1. history of the discovery and fossil heritage preservation since the 1860s there have been news regarding the presence of the lignite deposit in pietrafitta. in a document dated 1862, a project mentioned pietrafitta as a possible place for lignite exploitation (ambrosetti, 1992b). it is quite possible that lignite was since long time exploited by the population at a non-industrial level, as fuel for domestic use and for local manufacturing companies, thanks to the presence of a number of accessible outcrops (ambrosetti, 1992b). these moderate excavation activities, between the second half of the 19th century and the first decades of the 20th century, lead to the discovery of the first fossil vertebrate remains, which are now scattered in numerous european museum collections. in the open-cast mine of pietrafitta, fig. 19 the pietrafitta lignite seam in the poderone outcrop, year 1994. an unpublished stratigraphic section measured in the year 1994 is shown to the left, also reporting the position of the fruit and seed assemblages pf1 and pf2. the white objects at the bottom of the picture indicate the pf1 layer. sediment type: c, clay; l, lignite. martinetto e. et al. 50 the industrial production of lignite started in the early 20th century, but assumed a significant role, on both a local and national level, essentially in correspondence with the two world wars, and particularly with the inauguration of the enel (the national electricity corporation) thermo-electric power-plant in 1959, situated near the lignite deposit (ambrosetti, 1992b). in view of the poor quality of the lignite, the exploitation of the deposit in pietrafitta, thanks to the limited depth of seam top, has always been carried out in the open air, both in the period of manual excavation, until 1923, and during the mechanization of lignite extraction from 1923 until the end of the 20th century. the lignite seam of pietrafitta (fig. 19) had an extension approaching 200 hectares, with a slight slope and a thickness between 5 and 8.5 metres. the sediments capping the lignite seam consisted of sand, clay and silt with a thickness varying between 5 to 8 metres. it the year 1966 mr. luigi boldrini (friendly known as gigino), an assistant head miner and shift-worker, while systematically and continuously inspecting the excavations of the lignite deposit, began to set up the first palaeontological collection of pietrafitta (gentili et al., 2000a). in 1930, at the early age of 14, luigi boldrini began working in the mine. this miner "lover of palaeontology" (sorbini, 1990) spent more than 55 years hunting for fossils in the lignite mines of pietrafitta, both as an employee and later as a pensioner. although fossils were mostly recovered through simple techniques, gigino's strong passion permitted to build up the bases of the present day impressive collection. he dug up tonnes of lignite, with axes and chisels, thus rescuing hundreds of plant and animal fossil remains from being damaged by the large excavating machines. the findings were kept partly in the mine and partly in gigino’s home. people like boldrini call to mind the fossil hunters of past centuries whose collections laid the basis for the most important museums in europe (findlen, 1977; sorbini, 1990). it was only in the 1980s that the enel company and the archaeological survey for umbria, with the scientific support of the university of perugia, under the direction of prof. pierluigi ambrosetti and prof. lucilia gregori of the department of earth sciences, began the systematic collection and conservation of the fossil findings. the archaeological survey for umbria delegated the task of conservation and maintenance of the fossils to the enel company, while the university of perugia was entrusted with overseeing the operations of research, excavation, recovery and archiving of the specimens. this is how the palaeontological importance of pietrafitta was at last recognized "only" 20 years after luigi boldrini’s intuition. the direct intervention of the enel and the university led to a significant increase in the number and diversity of fossils retrieved (for instance, traces and remains of insects: odonata, diptera, coleoptera, lepidoptera, neuroptera). the pietrafitta deposit is characterized in particular by: a great abundance and diversity of fossils, with over two thousand specimens in the collections (gentili, 1991); macroand micro-mammal species occurring together in the same lignite levels (gentili et al., 1996); fossils in a good state of preservation even in the small morphological details, although they were affected by fragile-type deformation (ambrosetti et al., 1992a); lignite deposits accumulating over a short time span, perhaps no longer than 40,000 years (martini, personal communication); the possibility of a rapid recovery of large mammals, whose fossil skeletons have been extracted en bloc together with a part of the embedding lignite (ambrosetti et al., 1987, 1993). to give an idea of the richness of the palaeontological site it is enough to mention that in three years (from 1989 to 1991), from the "poderone" mine alone, over 1200 vertebrate skeletal elements were recovered and identified (gentili, 1991). actually, this collection can be considered as one of the most important in the quaternary of europe (gentili et al., 1997; zucchetta et al., 2003; petronio et al., 2005). at the end of the 1980s the scientific community was informed for the first time about the idea of establishing a palaeontological museum at pietrafitta (ambrosetti et al., 1987b). finally, thanks also to the great work of project coordination carried out over the past few years by the archaeological survey for umbria, and in particular thanks to dr. maria cristina de angelis, gigino’s dream has come true and the palaeontological museum "luigi boldrini" was set up near the town of pietrafitta and opened to the public in 2010. certainly, this was made possible thanks to the contribution of the community of pietrafitta, which, in recent years, has continuously identified itself with its palaeontological heritage (gentili et al., 2000a, b). nowadays, the educational itineraries carried out in the exhibition areas of the museum allow visitors to have a direct, not just virtual, experience with the problems regarding the strategies and methods for the study and reconstruction of past environment and life, in particular by analysing the taphonomic data. thus, the museum offers a view of palaeobiology "in the field", inserted into the social and cultural context of the pietrafitta area (gentili et al., 2003). 6.2 stratigraphy and previous palaeoenvironmental interpretations as reported above, the fossil assemblages discussed in this paper originate from the pietrafitta subsynthem, whose primary thickness was about 30 m. the pietrafitta subsynthem is in angular unconformity on the underlying fontignano unit (pazzaglia, 2007; argenti et al., 2013), and it is poorly visible today because most of it was removed during the cultivation of lignite, and the remaining part is covered by backfill, or is hidden below the artificial "pietrafitta lake". currently, the only outcrop is located in "poderone", the last mining site in the 1990s (fig. 19), before the abandonment of the quarries and the reconversion of the power station. the geometry of the lignite seam was reconstructed in the 1960s thanks to a series of perforations and geoelectric analy 51 plant record of dunarobba and pietrafitta sites ses (pazzaglia, 2007). it had a thickness varying between 6 and 12 m and was located at a maximum depth of 25 m below the ground level, mainly cropping out in the central part of the basin due to erosion of the cover (pazzaglia, 2007). according to ambrosetti et al. (1987b), lignites belonging to the pietrafitta subsynthem mainly consist of herbaceous remains of cyperaceae and poaceae deposited in situ, with no evidence of neither transport nor root remains. rare logs, up to 10-15 m long, strongly compressed due to the sediment load, were found especially in the area of "poderone". according to the facies analysis, ambrosetti et al. (1992a) referred the lignite deposits to a marshy area with abundant organic production. the marsh was probably located on the edge of a lake with fine clastic sedimentation (conti & girotti, 1978; ambrosetti et al., 1987b). lignite is intermingled with thin layers of organic clay bearing intraformational clasts, freshwater molluscs (ambrosetti et al., 1992a) and oligohaline ostracods (gliozzi et al., 1997), which may have been produced by high-energy events, such as storms, which remobilized the sediment of the lake bottom towards the marginal swamp (pazzaglia, 2007). 6.3. the early pleistocene vertebrates of pietrafitta the remains from pietrafitta constitute the richest collection of fossil vertebrates in the umbria region as well as the most important italian local faunal assemblage referred to the farneta faunal unit (late villafranchian; about 1.5 ma). most of the collection comes from the stratigraphic interval shown in fig. 19 and is formed by macroand, secondly, micromammals. additionally, the discovery of a considerable number of interesting although often fragmentary skeletal remains of bony fishes, amphibians, reptiles and birds is noteworthy. the fish remains are represented by isolated bones, pharyngeal teeth and few articulated skeletons preliminarily referred to the genera tinca, scardinius and leuciscus (family cyprinidae; corvetti, 2004). the 89 amphibian skeletal elements are attributed to two anura taxa: latonia cf. l. regei and rana ex gr. r. ridibunda (delfino et al., 2004). the large frog latonia appears in the oligocene of france and is quite abundant in the european neogene, whereas today is represented by a single species living in israel (biton et al., 2013). the report from pietrafitta is the last occurrence of this genus in europe. reptile remains are very rare at pietrafitta, but at least four taxa are recognized: three snakes (vipera cf. v. ammodytes, natrix sp. and colubrines indet.; delfino et al., 2004) and the european pond turtle emys orbicularis (kotsakis & gregori, 1985). the latter species is represented by a number of well-preserved carapaces and plastrons and testifies the presence of a shallow, clear freshwater palaeoenvironment. about one hundred of postcranial bones and bone fragments are referred to nine bird taxa: podiceps sp., phalacrocorax sp., cf. ixobrychus, cygnus sp., anas sp. (large size), anas crecca/querquedula, aythya sp., somateria aff. s. mollissima, rallidae indet., cf. gallus (zucchetta et al., 2003). this bird assemblage is one of the richest in the early pleistocene of europe. it is composed mainly by aquatic taxa, but cf. gallus is a true terrestrial form related to thick forest environments (zucchetta et al., 2003). the micromammals are poorly represented at pietrafitta. a small insectivore (sorex cf. s. minutus) and a lagomorph (oryctolagus cf. o. lacosti) are reported (argenti & kotsakis, 2009). the arvicolid species mimomys pusillus, microtus (allophaiomys) cf. m. (a.) ruffoi and m. (a.) chalinei (the latter represented by a single mandibular fragment) confirm the late villafranchian (i.e., early biharian) age of the site (gentili et al., 1996). the abundant cranial and postcranial remains of a larger rodent are referred to castor fiber plicidens, chronologically limited to the tasso and farneta faunal units (barisone et al., 2006). the rich sample of monkey skeletal remains (about 78 elements belonging to at least eight individuals) is attributed to macaca sylvanus florentina (gentili et al., 1998). carnivores are quite rare at pietrafitta. most of the specimens are referred to the medium-sized bear ursus etruscus, whose morphology (especially in the teeth) shows a number of more derived characters than the specimens from older italian late villafranchian sites, such as olivola and upper valdarno (rustioni & mazza, 1993). the presumed occurrence of the felid panthera gombaszoegensis needs to be confirmed by further studies. the carnivore assemblage is completed by the mustelid pannonictis nestii, represented by isolated teeth, postcranial elements and a nearly complete cranium with associated mandible (rook, 1995). the pietrafitta collection includes two partial skeletons and some isolated skeletal elements of a smallsized rhinoceros. mazza et al. (1993) recognize some tooth similarities with stephanorhinus etruscus, while the analysis of the postcranial material highlights strong affinities with s. hundsheimensis. because of the absence of well-preserved cranial remains, the authors refer the material to stephanorhinus cf. s. hundsheimensis. the artiodactyl sample from pietrafitta is mostly constituted by a medium-sized bovid belonging to the plio-pleistocene genus leptobos. the overall morphology of the skull and teeth is similar to that of l. vallisarni from the upper valdarno and val di chiana, but some differences in the horn cores and the absence of a sufficiently-complete comparative sample among the tuscan collections bring gentili & masini (2003) to refer the material to leptobos aff. l. vallisarni. two cervid species are recorded at pietrafitta: the medium-sized pseudodama farnetensis and the very large praemegaceros obscurus, both represented by well-preserved cranial and postcranial remains. a nearly complete cranium with articulated antlers of a sub-adult p. obscurus is one of the most remarkable specimens in the collection. azzaroli & mazza (1993) report a third taxon, eucladoceros sp., whose actual occurrence needs to be confirmed. finally, the sample of mammuthus meridionalis from pietrafitta is one of the richest in italy. in the light of the supposed chronologic correspondence between the pietrafitta local fauna and those from farneta (val di chiana) and scoppito (l’aquila), the pietrafitta elephantid has been often referred to the derived m. meridion martinetto e. et al. 52 alis vestinus. however, this subspecific attribution cannot be confirmed because of the lack of complete crania (ferretti, 1999 and references therein). on the contrary, the abundant molars from pietrafitta do not show significant differences with those of m. meridionalis meridionalis from the upper valdarno (ferretti, 1999). 6.4. macropalaeobotanical data for the pietrafitta succession a general survey of the plant macrofossil content of the whole lignite-bearing succession of pietrafitta, exposed for a thickness of 9.5 m, was carried out in the field during the year 1994. these observations showed that most lignite layers were made up by massive finegrained (humified?) plant material, and morphologically identifiable plant remains, e.g. angiosperm leaves or fern axes (fig. 20), were restricted to a few layers. very few fruits and seeds were directly visible in the field, and most of these were concentrated in a precise layer characterised by high clay content (pf1), laying 4.5 m below the base of the main lignite seam. the largest fruits (fig. 21) can be assigned to trapa cf. natans (a species of the modern italian flora), as suggested by a preliminary analysis of the material by j. wojcicki. conversely, other fig. 20 possible fern rhizomes photographed in the pietrafitta lignite. fig. 21 fruits of trapa cf. natans extracted from layer pf1, below the pietrafitta lignite seam. scale 1 cm. fig. 22 seeds of statiotes cf. intermedius extracted from layer pf1, at the base of the pietrafitta section. a1) seed in external view; a2) detail of the cells on the outer surface; b1) seed in internal view; b2) detail of the cells on the inner surface. fig. 23 leaves from the pietrafitta mine, boldrini collection, most probably originating from the silty-sandy layers above the lignite seam. all the specimens can be assigned to quercus, and that indicated by the arrow to q. cf. cerris. 53 plant record of dunarobba and pietrafitta sites plate ii fossil megaspores, fruits, and seeds from the pietrafitta site: 1, 2) azolla filiculoides: 1a, microspore from a group (massula) including also 2 megaspores; 1b, general view of the massula; 2, isolated megaspore; 3, salvinia cf. natans, megaspore; 4) ceratophyllum demersum, fruit; 5) cyperus glomeratoides: 5a, achene morphology; 5b, detail of the epidermal cells; 6) cyperus cf. longus: 6a, achene morphology; 6b, detail of the epidermal cells; 7) aldrovanda cf. zussii t. v. jakub.: 7a, seed morphology; 7b, detail of the epidermal cells; 8) cladium mariscus, endocarp; 9) myriophyllum spicatum, endocarp in lateral view; 10) decodon globosus, seed which has lost the germination valve, seen in ventral view; 11) najas minor: 11a, seed morphology; 11b, detail of the epidermal cells; 12) typha cf. latifolia: 12a, seed morphology; 12b, detail of the epidermal cells; 13) nymphaea borysthenica dorofeev, compressed seed; 14) potamogeton pannosus dorofeev, fruits with apparent remains of the exocarp, such as the flanges on the dorsal side, covering the endocarp; 15) potamogeton cf. crispus, complete fruit which distinctly shows the outline of the endocarp; 16) ranunculus sceleratus, fruit; 17) urtica dioica, seed. length of the scale bar reported for each specimen. martinetto e. et al. 54 tab. 3 list of fruit and seed taxa detected in four samples of the pietrafitta section. see fig. 19 for the stratigraphic position of samples pf1 and pf2. the precise position of pf0 is unknown, but it falls definitely within the main lignite seam. see tab. 1 for explanation of abbreviations. two forms of cm-sized seeds, observed in the field in the same layer (pf1), represent extinct species: stratiotes cf. intermedius (fig. 22) and euryale(?) nodulosa [the question mark after the generic name expresses the possible assignment of this species to the extinct genus pseudoeuryale dorofeev]. the analysis of bulk sediment samples from the trapa-bearing bed (pf1), and from another layer (pf2), located ca. 5 m above pf1, at the base of the main lignite seam, evidenced fossil fruit and seed assemblages which testify for the occurrence of consistently diverse palaeocommunities of freshwater macrophytes in the early pleistocene lake. a sample collected from an uknown position (pf0) is just mentioned here because of the occurrence of carex cf. elata, a species with possible biochronologic relevance (martinetto et al., 2012, in press). the precise determination allowed by the morphological characterisation of fruits and seeds provided a good taxonomic framing of the lacustrine palaeoflora (plate ii). at the state of the art, 23 species have been identified (tab. 3), and 15 of them represent plants still growing in italy today. other 8 species are believed to represent extinct plants, and 2 of them belong to genera (azolla, decodon) which are absent in the european native flora of the holocene, even if their fossil remains are reported in middle pleistocene inter 55 plant record of dunarobba and pietrafitta sites glacial sediments (velichkevich & zastawniak, 2006, 2008). most of the pietrafitta species were already reported for several early pleistocene localities of central and/or eastern europe, but a few ones were previously recorded only in east european localities. for example, the perfectly preserved seeds of aldrovanda, an aquatic genus with a single living species (which is now strongly endangered in italy), share all of the diagnostic characters with a. zussii t. v. jakub. (plate ii, 7), an extinct species whose seeds were found in a single pleistocene locality of belarus (velichkevich & zastawniak, 2008). the occurrence of plant species with east-european affinity had been already pointed out for the early pleistocene of northeastern italy (martinetto et al., 2012). the non-aquatic plants are represented in the pietrafitta assemblages by a few taxa which produce windor animaltransported fruits (e.g. vitis sp.). these findings are too scarce and do not contribute to the reconstruction of the ancient mesic vegetation growing around the depositional basin, which is documented by pollen assemblages. plant macrofossils originating from mesic communities were definitely present within silty layers covering the brown coal, which unfortunately never underwent a detailed macropalaeobotanical study. these contained angiosperm leaves, as proved by a few samples of this material, preserved in the boldrini collection (fig. 23), showing irregularly and acutely-lobed lanceolate leaves, which we assign to quercus cf. cerris. 6.5. palynology the pietrafitta lignite-bearing succession has been submitted to palynological studies since 1961, when ricciardi published the first data which concentrated especially on clay overlying the lignite seam. however some samples were also collected from the lignites as well as at the top of the underlying clay. the author pointed out the rarity of pinus haploxylon type, the absence of picea orientalis type and the sporadic occurrence of fagus. on the other hand carya was abundant as well as quercus; ulmus, pterocarya, zelkova, tsuga, corylus followed. liquidambar was exceptionally abundant, but not in the lignites, which were associated to cooler and moister conditions. the increase of abies alba just at the top of the section was related to a climate change towards oceanic conditions by ricciardi (1961). the palynological contribution of paganelli & solazzi (1962) was carried out on a 16.50 m thick section below a sandy pebble stratum, including 8.10 m of clay, a lignite bank (approx 7.50 m thick) and about 1 m of humic clay rich in shells of molluscs. later lona & bertoldi (1972) carried out a study on an outcrop including the lignite bank; the underlying clay was drilled and studied in core. in fig. 24 the original pollen plates of lona & bertoldi (1972) are reported. seven main pollen zones were described in the pollen diagram (fig. 25), which is split into two main parts by the strong and drastic reduction of "taxodiaceae". the lower part of the pietrafitta pollen record shows, in fact, a constant occurrence of "taxodiaceae", but also pinaceae, followed by liquidambar, magnoliaceae, castanea, sapotaceae, celastraceae, podocarpaceae, ginkgoaceae, arecaceae. the upper part includes pinus, abies, picea, tsuga, juglandaceae, ulmaceae, eucommia, betulaceae, aracaceae. moreover, the components of the so-called quercetum and carietum are quite abundant. herbaceous plants show successive phases of increase of artemisia and other asteraceae, ephedra, amaranthaceae, poaceae, caryophyllaceae, etc. the boundary between the lower and upper part of the pollen diagram was named "tiberian boundary" and correlated with the central european "taxodiaceae" disappearance event. the tiberian boundary was also described in marine deposits, i.e at stirone (lona et al., 1969; lona & bertoldi, 1972) and le castella (bertoldi, 1977). however, further evidence (see bertini, 2010 and references therein) demonstrated: 1. the recurrent sudden falls in the pollen percentages of "taxodiaceae" throughout the gelasian; and 2. the persistence of "taxodiaceae" after 1.8 ma in many italian sites. 7. discussion the plant record of the two main fossil sites of pietrafitta and dunarobba, with the addition of cava toppetti i and ii, fosso bianco, torre picchio and villa san faustino sections, provide us with a good glimpse on the central italian palaeoenvironments. dunarobba is one of the few sites in the world yielding upright trunks in a mummified fossil forest. other famous examples, apart bukkabrany (in hungary, 7.7-6.3 ma: kàzmér, 2008; csaszar et al., 2009; erdei et al., 2009; gryc & sakala, 2010; erdei & magyari, 2011), bear definitely shorter trunks, for example in the arctic region of canada (axel heiberg island, about 45-40 ma: bigras et al., 1995; williams et al., 2008), and in nw italy (stura di lanzo fossil forest, ca. 3.0 ma: martinetto et al., 2007; vassio et al., 2008). yet, the dunarobba site is unique, not only for the presence of the dunarobba fossil forest, but also for having provided the highest number of fruit and seed species so-far detected in the plioceneearly pleistocene of the italian peninsula. thus, the palaeocarpological dataset here consistently integrates the pollen record, available for many other sites (lona & bertoldi, 1972; urban et al., 1983; pontini & bertini, 2000; pontini et al., 2002; bertini, 2010, 2013; magri et al., 2010; sadori et al., 2010; magri & palombo, 2013), ________________________________________________________ fig. 24 microphotographs of some pollen types from pietrafitta as documented by lona & bertoldi (1972). a, original plate iv by lona & bertoldi (1972): 1, 2. sequoia type; 3. sciadopitys; 4-10. taxodium type; 11. taxodium type; 12. keteleeria; 13. tsuga; 14. "small" picea. b, original plate v by lona & bertoldi (1972): 1. pinus haploxylon (s.s.) type; 2. cupressaceae; 3. inaperturate grain; 4. pterocarya; 5. cf. platycarya; 6. zelkova; 7. quercus ilex type; 8-11. eucommia; 12. celtis; 13. celtis reticulata torr. (modern); 14. magnoliaceae; 15. monocolpate grain; 16-17. liquidambar; 18. cf. aesculus; 19. tricolporopollenites cingulum cf. fusus (r. potonie) th. et pf.; 20. hedera type. martinetto e. et al. 56 57 plant record of dunarobba and pietrafitta sites and makes the dunarobba palaeoflora very rich of palaeovegetational and palaeoclimatic information, despite its still uncertain age. the macrofossil plants of the pietrafitta site are not exceptional for their preservation state, but for the context in which they were found, being associated to a rich vertebrate palaeofauna. the diversity of the aquatic palaeoflora is remarkable, and a few species (aldrovanda cf. zussii, potamogeton pannosus) are documented here for the first time in italy. further studies would be needed to assess their relevance in biogeography as well as biochronology. the common feature of the two studied localities is the occurrence of autochthonous fruit and seed assemblages both in dunarobba (in 3 sections and several layers) and in pietrafitta, whose analysis can throw light on the floristic composition of the local vegetation of these waterlogged palaeoenvironments. the reconstruction of extralocal vegetation and climate changes are provided by the integration of pollen data. 7.1 local palaeovegetation studies on autochthonous fruit and seed assemblages in modern lakes and mires (birks, 1973; collinson, 1983; greatrex, 1983; dunwiddie, 1987; spicer & wolfe, 1987; thomasson, 1991; dieffenbacher krall & halteman, 2000) showed that a high-medium frequency of certain species, and their occurrence in several samples of the same deposit, usually indicates their participation in the local palaeovegetation. in the samples of lignite and muddy sediments of the dunarobba lignite and forest sections, fruit and seed assemblages show a scanty representation of plants from well-drained substrates, and the hydrophytes are almost completely absent, except for sporadic fruits of potamogeton. these probably underwent a short transport, coming from slightly deeper areas. in consideration of the generalised dominance of the hygrophilous plants we can conclude that the palaeoenvironmental context was probably characterised by large areas covered by wetland vegetation, and the closest mesic communities were growing at least several hundred meters apart (basilici, 1992, p. 80). the large floristic similarity of the df1-6 plus dl1 (lignite and forest sections) and dc3 (dc section) assemblages (tab. 1) proves that the same type of palaeoflora existed during the sedimentation of the dc section and of the succession embedding the dunarobba fossil forest trunks. both in the df1-6 plus dl1 and in the dc3 ancient plant communities, the following woody elements had to be present: alnus sp., cephalanthus dorofeevi, cornus aff. amomum and glyptostrobus europaeus. among the herbaceous forms, carex pseudocyperus was important only in certain areas and/ or phases of development of the forest section, while cladium paleomariscus and schoenoplectus isolepioides occurred in both the forest section and the dc3 palaeocommunities. the latter species would participate to the herbaceous layer of swamp forests, and/or form a distinct sedge palaeocommunity. among the aquatic taxa, potamogeton fruits occur in both the forest section and dc section assemblages, and in this last section it is represented also by pollen. the nearest living relatives (nlrs) of the aforementioned species (alnus spp., cephalanthus occidentalis, cornus amomum, cladium mariscus, schoenoplectus spp.) correspond to typical plants of waterlogged environments. the pollen spectra of the part of the forest section which contains the trunks are very rich in taxodium type pollen, which confirms the result of wood analysis as for the dominance of a taxodioid plant in the local swamp forest. for a more accurate determination of the dominant taxodioid species in the df, it useful to point out that all the samples with autochthonous/parauthochtonous remains contained seeds and cones of a single species, glyptostrobus europaeus. two other species of taxodioidaeae (cryptomeria rhenana in dc1a-b and sequoia abietina in dc2) appear only in allochthonous assemblages and would therefore originate from the extralocal palaeovegetation. therefore, the hypothesis (martinetto, 1994; basilici, 2008) that the in situ stumps and logs belong to the "glyptostrobus europaeus whole plant" (vassio et al., 2008) takes on greater support. yet, the wood-anatomical assignment of the large dunarobba trunks to taxodioxylon gypsaceum (biondi & brugiapaglia, 1991) is problematic, because the wood of fig. 25 pollen diagram published by lona & bertoldi (1972) based on the study of a succession drilled in the 1960s in the pietrafitta site. seven pollen zones were distinguished (a-g). p.n.a. = non-arboreal plants. martinetto e. et al. 58 the "glyptostrobus europaeus whole plant" should be assigned to the wood morphospecies glyptostroboxylon rudolphii dolezych et van der burgh (see teodoridis & sakala, 2008). in view of the recent description of this last morphospecies (dolezych & van der burgh, 2004), we suggest that a revision of the wood anatomy of the dunarobba trunks is badly needed. we consider the evidence provided by shoots, cones and seeds (tab. 1) as sufficient to reconstruct extensive glyptostrobus swamp forests in the dunarobba site, at the margin of the ancient tiberino lake (fig. 26). even the deposition of the lignite layer dc3 of the dc section (fig. 7), despite not having observed the presence of in situ trees, can be traced back to a marginal area of a glyptostrobus swamp forest, due to the abundance of macroremains of this plant which has been detected in the bulk sediment sample (tab. 2). fossil forests dominated by glyptostrobus europaeus are known from other pliocene sites of italy, e.g. the above-mentioned stura di lanzo fossil forest, and an upper valdarno site (le matole) in tuscany (martinetto, unpublished data). the record of such forests is probably also reflected in some pollen diagrams showing a high percentage of taxodium type (also including glyptostrobus), such as the zanclean and early piacenzian diagram of the stirone section (bertini, 2003) and the piacenzian diagram of the upper valdarno basin (santa barbara section: bertini, 2013). the taxodium type occurs, with progressively reduced percentages, also in some early pleistocene sections of northern italy, e.g. the leffe section (ravazzi & rossignol strick 1995) and the lamone section (fusco, 2007). at pietrafitta, two plant macrofossil assemblages document freshwater macrophyte palaeocommunities with relevant similarities to the ones of modern italian lakes (tab. 3). nevertheless, the detailed morphological analysis of fossil fruits and seeds allows us to recognize precise morphospecies (e.g.: cyperus glometratoides, decodon globosus, nymphaea borysthenica), which most probably represent extinct plants (velichkevich & zastawniak, 2003, 2006). plant assemblages with this same species association are known in eastern europe (velichkevich & zastawniak, 2003, 2006), and similarities can be found also in a palaeoflora described from ne italy (martinetto et al., 2012), because of a characteristic association between taxa of miocene origin (decodon globosus), the rare pliocene-pleistocene element nymphaea borysthenica, and the "younger" ones (possibly postpiacenzian immigrants) carex cf. elata and cyperus glometratoides. another very similar palaeofloral association has been detected in the "trapa layer" flora of buronzo, in nw italy, interpreted as gelasian (martinetto, 1999; martinetto & festa, 2013); on the other hand we cannot cite any assemblage with the same characteristics in central and western europe. as discussed above, studies on modern fruits and seeds in bottom sediments of lakes and ponds showed that the composition of the assemblages reflects rather faithfully the local vegetation (within a few tens of metres), and the record of the regional vegetation is scanty. this explains the dominance of fruits and seeds of aquatic plants in the pietrafitta assemblages, which would reflect the floristic composition of the local plant communities growing in the ancient lake. the diaspores of submerged (aldrovanda, ceratophyllum, myriophyllum, najas, stratiotes), rooted (nymphaea, potamogeton, trapa) or free-floating (azolla) macrophytes are dominant in the pietrafitta sediments, but some emergent aquatic plants (helophytes, such as cyperus, decodon and typha) are also not rare. two plants (nymphaea, najas) require at least 1 m deep water in a standing-water environment. the non-aquatic plants are represented by a few taxa which produce windor animaltransported fruits (e.g. vitis sp.), whose findings are rare and do not contribute to the reconstruction of the ancient mesic vegetation, growing around the depositional basin, which is documented by the pollen assemblages. as a whole, these freshwater macrophytes permit to accurately characterize the ancient vegetation of the two analysed layers of the pietrafitta lacustrine basin (pf1, pf2), that show minor floral differences (tab. 3). the carpological remains found in each layer allow us to recontruct at least tre belts ot lake margin vegetation: a shallow-water belt with carex, decodon and typha (with the addition of cladium, cyperus, ranunculus and schoenoplectus for pf1, and urtica for pf2), an intermediate belt with aldrovanda, azolla, ceratophyllum and oenanthe (with the addition of myriophyllum, potamogeton, salvinia and stratiotes for pf1), and a deeper -water belt with najas and nymphaea (and possibly myriophyllum, potamogeton, stratiotes and trapa for pf1). 7.2. extralocal palaeovegetation and palaeoclimate as for dunarobba, the macrofloral record of the extralocal vegetation is mainly provided by pollen assemblages from both dc and forest sections, accompanyied by rare fruits and seeds of the forest section, and by much more abundant ones from the dc1-2 layers of the dc section, with transported (allochthonous) plant assemblages. as discussed above, the carpological assemblages of the dc1-2 layers and of the studied layers of the forest section show a high floristic similarity (tab. 1), and most probably reflect the same phase fig. 26 reconstruction of the sedimentary context and plant cover at the ancient lacustrine margin of dunarobba. 59 plant record of dunarobba and pietrafitta sites of vegetation development, so we will discuss together their record. at the present state of knowledge the concomitant record of pollen and carpoflora is not yet rich enough to propose the reconstruction of vegetation transects as in bertini & martinetto (2011). a useful information to define the features of the extralocal vegetation is provided by the reconstructed habit of the mesic elements: both in the forest section and dc section plant assemblages (tabs. 1, 2) they mostly belong to woody plants, in particular trees. this means that the zonal vegetation was a forest, and there is no evidence of herbaceous formations of regional importance. only in the hygrophilous palaeocommunities the herbaceous plants were important and diversified. from the biogeographical point of view, many of the genera found in the dunarobba sections are currently confined to east asian regions: cathaya, cryptomeria, glyptostrobus, pterocarya (also west asia), sabia, and sinomenium. on the contrary, the genera exclusively growing in north america are cephalanthus, decodon, proserpinaca and sequoia. the remaining exotic genera have today a palaeotropical (sabia and toddalia), pantropical (cyclea, eurya, ficus, magnolia, meliosma, saurauia) or disjunct asian-american distribution (alangium, chamaecyparis, liriodendron, sassafras, symplocos, zanthoxylum). the modern vegetation of some east asian regions shows a closer affinity to the dunarobba palaeofloras and is used as a model, also for the climatic interpretation (as in gregor et al., 1989). from the floristic point of view, the association of the genera ampelopsis, cryptomeria, magnolia, sinomenium, styrax and symplocos allows us to establish a link between the dunarobba palaeofloras and the modern "mixed mesophytic forest" of japan (mai & walther, 1988), but also of china (wang, 1961). on this basis, we can tentatively reconstruct a mixed mesophytic forest vegetation type, sensu wang (1961) and wolfe (1971), i.e. a prevalently deciduous forest with high species diversity, growing within the warm temperate cfa climatic zone (kottek et al., 2006). more in detail, the presence of such humid "subtropical" elements (zagwjin, 1990) as cyclea (dr1, dc1a), ficus, eurya (dc1a-b), meliosma canavesana (dc1b), symplocos casparyi (dc1a-b) and toddalia (dc1a-b, dc3, dc4) would indicate a type of "mixed mesophytic forest" similar to that growing today close to the transition to the "evergreen broad-leaved forest", which is richer in evergreen trees (hou, 1983). martinetto (1996), referring to the diagram of wolfe (1971), supplemented with data from hou (1983), numata (1974) and satoo (1983), obtained the following climatic parameters for the dunarobba palaeofloras (transition mixed mesophytic forest/evergreen braoad-leaved forest): average annual temperature around 13-14 °c. average annual rainfall in the range 1000-3000 mm. the above temperature estimation is not in contrast with the new temperature data provided by grimm & denk (2012), which define an interval between 9 °c and 21 °c for the plant taxa occurring at dunarobba (see climatic data in fig. 27), tentatively restricted to the interval 14-21 °c according to the whole dataset reported in fig. 27 (excluding the relic genus tetraclinis, >15°c). finally, the dunarobba palaeofloras are framed in the context of a warm and humid temperate palaeoclimate (cfa sensu köppen-geiger: kottek et al., 2006), and the presence of "subtropical" elements allows us to exclude severe winter frost. the long pollen record from the dunarobba s2 core (fig. 18) shows successive phases of reduction vs expansion of taxodium type (followed by some elements of the mixed deciduous broad-leaved forest) and pinus. such pattern supports the image of a landscape submitted to humidity fluctuations, but within a prevalent humid, warm temperate climate. also the chemical and physical features of the palaeosols demonstrate that climate conditions did not change remarkably from the bottom of the forest section to the top of the palaeosol section (fig. 8). in fact the absence of important expansions of herbs in the pollen diagram indicates that humidity fluctuations were never dramatic, and there is no definite evidence of glacial/interglacial cycles. the pinaceae pollen increase during the relatively moister phases can be attributed to lake level rises (larger basin = over-representation of pinus pollen). successively, the pollen curve of the taxodium type shows a definite increase, which indicates an expansion of swamps. the following phase of humidity lowering determined the expansion of mixed deciduous broad-leaved forest in the areas closest to the lake coast. in synthesis, the vegetation and climate reconstructed for the dunarobba sections are similar to those of the cava toppetti i section, the zone iii of the fosso bianco pollen diagram, and the warmest phases of the cava toppetti ii pollen diagram. however, the cava toppetti ii and fosso bianco pollen records show more apparent vegetation and climate changes (see 4.2. and 4.3.), whereas the cava toppetti i and dunarobba pollen records indicate fairly stable conditions. in the pietrafitta succession the extralocal vegetation is only documented by pollen. the long pollen diagram of lona & bertoldi (1972) shows consistent variations in the pollen percentage of taxa indicating different vegetation types. a progressive increase of taxodium type, till to a complete dominance, would suggest a warm temperate climate (kottek et al., 2006) of "subtropical" type. the abundance of taxodium type also indicates the local establishment of a taxodiod swamp forest, possibly similar to the dunarobba one, even if here we have no macrofossil record of such a plant community. later on the taxodium type nearly disappears, marking the so-called "tiberian boundary" of lona & bertoldi (1972). from this horizon onwards the pollen of the so-called "quercetum" taxa dominates, together with carya and pterocarya. the extralocal vegetation of the this pollen zone, comprising the basal part of the lignite seam, was a mixed deciduous broadleaved forest indicating a warm temperate climate (kottek et al., 2006) and sufficient humidity. at the top of the diagram there is a prevalence of pinus and herbaceous pollen, suggesting a cool phase with conifer forests and open vegetation, possibly growing under a snow climate (kottek et al., 2006). martinetto e. et al. 60 fig. 27 biochronological chart of selected fruit and seed species based on data from northern italy. the black boxes to the right side (dunarobba columns) indicate occurrence in our samples (see tabs. 1, 2). mes = messinian; gel = gelasian. the listed taxa have been gathered in 6 main carpo-groups, according to martinetto et al., in press. a simple characterisation of the growth forms of the listed taxa is reported in the two columns named respectively "deciduous/evergreen" and "habit", where "c", "h", "s" and "t" stand for climber, herb, shrub and tree. the thermal climatic requirements of each species have been synthetically expressed by the boundary values of mean annual temperature (nlr clim. boundaries), e.g.: >13 = distribution of nearest living relatives (nlrs) mainly in areas where the mat is higher than 13°c; <14 = distribution of nlrs mainly in areas where the mat is lower than 14°c; u = uncertain, b = broad climatic distribution (literature sources: ^grimm & denk, 2012; *utescher and mosbrugger, 2013; #other sources, reported in martinetto et al., in press). the column "exotic/native" (ex/n) is referred to the nlrs, and "x" means no-nlr (extinct genus or morphogenus). 61 plant record of dunarobba and pietrafitta sites the pietrafitta pollen diagram (fig. 25), when compared to that of the dunarobba s2 core (fig. 18), distinctly differs for a significant increase of herbaceous pollen in the c zone, with dominance of the steppe element artemisia. similar phases of steppe elements increase occur in the fosso bianco pollen diagram (fig. 4). at the light of the vegetation dynamics pointed out by the long pollen record from pietrafitta, the macrofloral data provided by the torre picchio section (girotti et al., 2003) can be referred to a mixed deciduous broadleaved forest phase, indicating a warm temperate climate and sufficient humidity. the villa san faustino macroflora (martinetto, 1996) can be referred to a colder phase with mixed conifer (abies, picea) and deciduous broad-leaved forests, even if the climate was still possibly of c type according to the köppen-geiger classification (kottek et al., 2006). 7.3. biochronology of plant assemblages the stratigraphic study of the pollen assemblages in late cenozoic successions of italy led to the proposal of biostratigraphic schemes (lona & bertoldi, 1972; bertoldi, 1990; bertoldi et al., 1994), in which a few units were distinguished on the basis of the progressive disappearance, or extreme reduction, of some thermophilous plants. these schemes were also used to interpret the chronology of the even more apparent disappearance of thermophilous plants seen in fruit and seed assemblages (martinetto, 1995, 1999). more recent studies posed the necessity of a revision of such disappearance times (bertini, 2010; martinetto et al., in press), and put forth the longer persistence of some species in central italy with respect to the northern part of this country (martinetto, 2001). this means that it is very difficult, in central italy, to assess the age of a deposit on the basis of the assemblage of extinct plants that it contains. the analysis of the distribution in northern italy (martinetto et al., in press) of the fruit and seed species of dunarobba (fig. 27) shows how several "zanclean" (carpo-group 1) or "zancleanpiacenzian" (carpo-groups 2 and 3) elements are still found in the dunarobba sediments (alangium deutschmannii, cyclea palatinati-bavariae, litsea sonntagii, meliosma canavesana, magnolia allasoniae, tetraclinis salicornioides, toddalia latisiliquata and zanthoxylum ailanthiforme). this situation may be explained in 2 ways: 1) the dunarobba succession has a zanclean or piacenzian age; 2) several elements of carpo-groups 1-3 persisted after the end of the piacenzian in central italy. if the second case is true, the dunarobba succession may well have a gelasian age, as proposed by bizzarri et al. (2011). however, the gelasian is wellknown for the instauration of glacial/interglacial cycles, and the analysis of the dunarobba s2 core pollen diagram (fig. 18) does not provide any evidence of such cycles (i.e. alternations among deciduous broadleaved forest and steppe or microtermic coniferous forest). rather, the continuos curve of the taxodium type would fit better within the pliocene. on the other hand, the onset of well defined glacial/interglacial cycles has been observed troughout both the fosso bianco and the pietrafitta sections, and fits very well with the age of these sections, respectively gelasian and calabrian. the early gelasian glacial phases, as detected in the fosso bianco section, are often characterized by the expansion of picea and abies, and the decrease of the thermophilous elements, such as taxodium type. sometimes they correspond to the expansion of herbs, including artemisia, whose increase, however, preceedes that of picea. for these features such glacial phases show an intermediate pattern between those described for the central mediterranean littoral (e.g. at vrica: combourieunebout, 1993) and the north apennine ones (bertini, 2001; fusco, 2007). at pietrafitta there are no elements of carpogroups 1-4, and only carex cf. elata was listed by martinetto et al. (in press) as an element of carpo-group 6, distributed from the gelasian to the holocene. however, several extinct carpological species occur (aldrovanda cf. zussii, cyperus glometratoides, decodon globosus, nymphaea borysthenica, potamogeton pannosus, euryale(?) nodulosa, stratiotes cf. intermedius), and form a characteristic assemblage, similar to those assigned to the late pliocene-early pleistocene in east europe (velichkevich & zastawniak, 2003), and to an early pleistocene assemblage in west asia (melamed et al., 2011). at the present state of the art the association of fruit and seed species of pietrafitta, although characteristic, does not provide definite biochronological indications, and further studies are needed in two directions: 1) the improvement of the taxonomic accuracy (e.g. aldrovanda cf. zussii, carex cf. elata, salvinia cf. natans, stratiotes cf. intermedius, trapa cf. natans); 2) the study of a larger number of well-calibrated early pleistocene sections with carpofloras. however, vertebrate biochronology (see 6.3.) permitted to assign to a definite part of the calabrian (1.5-1.3 ma) the stratigraphic intervals including both the carpological sample pf1 and pf2. 8. conclusion the plant remains of the dunarobba and pietrafitta sites provide abundant information on two different phases of palaeofloral development in central italy. the dunarobba sections are assigned, mainly on the basis of continental mollusc biochronology, to the piacenziangelasian interval, whereas the pietrafitta section, till to 6 m below the lignite seam, is reliably dated to the middle part of the calabrian thanks to vertebrate biochronology. the age of the non-outcropping layers rich in taxodium type pollen, laying ca. 8 m below the lignite seam bottom, is still uncertain. at dunarobba, information provided by autochthonous fruit and seed assemblages has been combined with physical stratigraphic data to conclude that the remarkable fossil forest was produced by an ancient swamp vegetation dominated by glyptostrobus europaeus, a conifer species whose nearest living relative is the east asian tree glyptostrobus pensilis. the dunarobba trees grew in a wetland with high sedimentation martinetto e. et al. 62 rate, bordering the ancient tiberino lake. the disappearance of the wetland and the glyptostrobus forest was due to the establishment of well-drained palaeoenvironmental conditions, testified by a palaeosol profile. chemical and physical features of the palaeosols demonstrate that climate conditions did not change, so this palaeoenvironmental variation was probably caused by local morphological changes induced by tectonics. the successive restoration of the wetland conditions was not sufficient for the preservation of in situ tree trunks. the well-drained palaeoenvironments around the palaeo-swamp of the dunarobba fossil forest were covered by forests having a floristic affinity to the modern mixed mesophytic forests of east asia, as proved by rich, water-transported fruit and seed assemblages. so, in the warm phases of the pliocene-pleistocene transition, the vegetation in central italy was very similar to the one which was present, in older times (prepiacenzian), in central-western europe. the relative uniformity of the pollen curves in a 50 m long diagram suggests that the extra-local vegetation and climate remained stable for a long time span. conversely, the pietrafitta pollen record suggests that, during the calabrian, the east-asian character of the extra-local vegetation was less apparent, and more frequent, sometimes abrupt, vegetation changes occurred. the vertebtrate-bearing lignite seam was initially deposited in a humid warm temperate phase, when the pietrafitta palaeolake was surrounded by broad-leaved deciduous forests. the aquatic and wetland plant communities still comprised several exotic plants (e.g. azolla, decodon, euryale(?), etc.) and extinct species of east european affinity (e.g. cyperus glomeratoides, nymphaea borysthenica, potamogeton pannosus). acknowledgements the preparation of this paper was stimulated by a field-trip of the 9th european palaeobotany-palynology conference held in padova in the year 2014: we thank the organisers and the participants for their interest and support. we also thank pierluigi ambrosetti and chiara benigni, for the photographs and information on the first phases of exposure of the dunarobba fossil forest; simonetta cirilli, oriana pauselli and sabrina simonetti, who provided us with precious documents and analyses carried out by them. we thank in particular maria cristina de angelis of the umbria region archaeological survey for the constant support and encouragement for the analysis of palaeontological materials. we also thank giovanni monegato and vasilis teodoridis, who greatly improved the manuscript with their accurate revision. references abbazzi l., albianelli a., ambrosetti p., argenti p., basilici g., bertini a., gentili s., masini f., napoleone g., pontini m.r. (1997) paleontological and sedimentological record in pliocene distal alluvial fan deposits at cava toppetti (todi, central italy). bollettino della società paleontologica italiana, 36 (1-2), 5-22. ambrosetti p., argenti p., basilici g., gentili s., ikome f.e. (1992a) the pleistocenic fossil vertebrata of the pietrafitta basin (umbria, italy): preliminary taphonomic analyses. in: gall j.c. & grouvogelstamm l. (eds), taphonomy: processes and products. european paleontological association workshop, strasbourg, 20-21. ambrosetti p., basilici g., capasso-barbato l., carboni m.g., di stefano g., esu d., gliozzi e., petronio c., sardella r., squazzini e. (1995a) il pleistocene inferiore nel ramo sud occidentale del bacino tiberino (umbria): aspetti litostratigrafici e biostratigrafici. il quaternario, 8, 19-36. ambrosetti p., basilici g., ciangherotti a.d., codipietro g., corona e., esu d., girotti o., lo monaco a., meneghini m., paganelli a., romagnoli m. (1995b) la foresta fossile di dunarobba (terni, umbria, italia centrale): contesto litostratigrafico, sedimentologico, palinologico, dendrocronologico e paleomalacologico. il quaternario, 8(2), 465 -508. ambrosetti p., bocciarelli a., gentili s., sala b. (1993) il recupero di grandi mammiferi fossili nella miniera di pietrafitta. in: masetti bitelli l. (ed.), la conservazione e il restauro oggi: archeologia recupero e conservazione, 3° volume. nardini editore, firenze, 27-37. ambrosetti p., capurso r., covino r., gallo g., monicchia r., salvatici b. (1992b) storia, energia, ambiente: un modello di centrale a pietrafitta. casa editrice protagon, città di castello, 114 pp. ambrosetti p., carboni m.g., conti m.a., esu d., girotti o., la monica g.b., landini b., parisi g. (1987a) il pliocene ed il pleistocene inferiore del bacino del fiume tevere nell'umbria meridionale. geografia fisica e dinamica quaternaria, 10, 10-33. ambrosetti p., cattuto c., gregori l. (1989) geomorfologia e neotettonica nel bacino di tavernelle/ pietrafitta (umbria). il quaternario, 2(1), 57-64. ambrosetti p., faraone a., gregori l. (1987b) pietrafitta: un museo paleontologico in umbria. museologia scientifica, 4(1-2), 99-118. argenti p. (2004) plio-quaternary mammal fossiliferous sites of umbria (central italy). geologica romana, 37, 67-78. argenti p., bizzarri r., pazzaglia f. (2013) iv.5 successioni dei bacini sedimentari plio-pleistocenici. in: m. barchi, m. marroni (a cura di) note illustrative della carta geologica d’italia alla scala 1:50.000 foglio 310 "passignano sul trasimeno", 74-99. ispra, regione umbria. argenti p., kotsakis t. (2009) the fossil remains of soricidae and leporidae (mammalia) in the lower pleistocene of pietrafitta (perugia, central italy). bollettino della società paleontologica italiana, 48(1), 59-62. azzaroli a., mazza p. (1993) large early pleistocene deer from pietrafitta lignite mine, central italy. palaeontographia italica, 80, 1-24. baldanza a., sabatino g., triscari m., de angelis m.c. (2009) the dunarobba fossil forest (umbria, italy): mineralogical transformations evidences as possible decay effects. periodico di mineralo 63 plant record of dunarobba and pietrafitta sites gia, 78, 51-60. barchi m., brozzetti f., lavecchia g. (1991) analisi strutturale e geometrica dei bacini della media valle del tevere e della valle umbra. bollettino della società geologica italiana, 110, 65-76 barisone g., argenti p., kotsakis t. (2006) pliopleistocene evolution of the genus castor (rodentia, mammalia) in europe: c. fiber plicidens of pietrafitta (perugia, central italy). geobios, 39, 757-770. basilici g. (1992) il bacino continentale tiberino: analisi sedimentologica e stratigrafica. tesi di dottorato inedita, università di bologna, 323 p. basilici g. (1995) sedimentologia della parte distale di un conoide alluvionale del pliocene superiore (bacino tiberino, umbria). il quaternario, 8, 3752. basilici g. (1997) sedimentary facies in an extensional and deep-lacustrine depositional system: the pliocene tiberino basin, central italy. sedimentary geology, 109, 73-94. basilici g. (2000a) floodplain lake deposits on an early pleistocene alluvial plain (tiberino basin, central italy). in: gierlowski-kordesch e.h. & kelts k.r. (eds.), lake basins through space and time. aapg studies in geology, 46, 535-542. basilici g. (2000b) pliocene lacustrine deposits of the tiberino basin (umbria, central italy). in: gierlowski-kordesch e.h. & kelts k.r. (eds.), lake basins through space and time. aapg studies in geology, 46, 505-514. basilici g. (2008) vita e morte di una foresta di glyptostrobus sp. del pliocene superiore. in: barili a., basilici g., cerquaglia z. & vergoni s. (eds.), foresta fossile di dunarobba ricerche. ediart, todi, 35-48. basilici g., martinetto e., pavia g., violanti d. (1997) paleoenvironmental evolution in the pliocene marine-coastal succession of val chiusella (ivrea, nw italy). bollettino della società paleontologica italiana, 36(1-2), 23-52. bellucci l., bona, f., corrado, p., magri, d., mazzini, i., parenti, f., scardia, g., sardella, r., in press. evidence of late gelasian dispersal of african fauna at coste san giacomo (anagni basin, central italy): early pleistocene environments and the background of early human occupation in europe. quaternary science reviews. doi: 10.1016/ j.quascirev.2013.10.011 bertini a. (2001) pliocene climatic cycles and altitudinal forest development from 2.7 ma in the northern apennines (italy): evidences from the pollen record of the stirone section (5.1 to ca. 2.2 ma). geobios, 34, 253-265. bertini a. (2003) early to middle pleistocene changes of the italian flora and vegetation in the light of a chronostratigraphic framework. il quaternario (italian journal of quaternary sciences) 16 (1bis), 19-36. bertini a. (2010) pliocene to pleistocene palynoflora and vegetation in italy: state of the art. quaternary international, 225, 5-24. bertini a. (2013) climate and vegetation in the upper valdarno basin (central italy) as a response to northern hemisphere insolation forcing and regional tectonics in the late pliocene-early pleistocene. italian journal of geosciences (bollettino società geologica italiana) 132(1), 137-148. bertini a., martinetto e. (2011) reconstruction of vegetation transects for the messinian-piacenzian of italy by means of comparative analysis of pollen, leaf and carpological records. palaeogeography, palaeoclimatology, palaeoecology, 304, 230-246. bertoldi r. (1977) studio palinologico della serie di le castella (calabria). atti accademia nazionale lincei, 62 (4), 535-547. bertoldi r. (1990) apporto della palinologia alla conoscenza dei giacimenti continentali pliocenici e pleistocenici inferiori dell'italia centrosettentrionale. st. trent. sc. nat., acta biol., 66, 915. bertoldi r., binotti a., castello f. (1994) reevesia and itea in the pollen flora of the upper neogene continental deposit at sarzana (lower magra valley, northern italy). review of palaeobotany and palynology, 80, 159-172. bigras c., bilz m., grattan d.w., gruchy c. (1995) erosion of the geodetic hills fossil forest, axel heiberg island, northwest territories. arctic, 48, 342-353 biondi e. (1984) sul "trattato del legno fossile minerale" di francesco stelluti accademico linceo da fabriano: con ristampa anastatica dell'opera. comune di fabriano, fabriano, 1-20. biondi e., brugiapaglia e. (1991) taxodioxylon gypsaceum (goppert) krausel in the fossil forest of dunarobba (umbria, central italy). flora mediterranea, 1, 111-120. biondi e., brugiapaglia e. (2000) i legni fossili della foresta fossile di dunarobba. in: comune di avigliano umbro (ed.) la foresta fossile di dunarobba, contesto geologico e sedimentario. la conservazione e la fruizione. atti del convegno internazionale (avigliano umbro 22-24 aprile 1998). ediart, todi, 65-69. birkeland p. w. (1999) soils and geomorphology, 3rd edition. oxford university press, 430 pp., new york. birks h.h. (1973) modern macrofossil assemblages in lake sediments in minnesota. in: birks h.j.b. & west r.g. (eds.) quaternary plant ecology, 173189. blackwell. biton r., geffen e., vences m., cohen o., bailon s., rabinovich r., malka y., oron t., boistel r., brumfeld v., gafny s. (2013) the rediscovered hula painted frog is a living fossil. nature communications, 4, doi: 10.1038/ncomms2959. bizzarri r., albianelli a., argenti p. baldanza a., colacicchi r., napoleone g. (2011) the latest continental filling of valle umbra (tiber basin, central italy) dated to one million years ago by magnetostratigraphy. il quaternario, 24(1), 51-65. bizzarri r., pazzaglia f., barchi m.r., passeri l., argenti p. (2008) inquadramento stratigrafico dei depositi continentali quaternari nel f. 310 "passignano sul trasimeno" ed evoluzione dei martinetto e. et al. 64 bacini plio-pleistocenici del confine tosco-umbro. atti del convegno "il quaternario nella cartografia carg" (roma, 21-22 febbraio 2008), 10. boyce c.k., hazen r.m.,knoll a.h. (2001) nondestructive, in situ, cellular scale mapping of elemental abundances including organic carbon in permineralized fossils. proceedings of the national academy of sciences of the united states of america, 98(11), 5970-5974. brozzetti f., basilici g. (1998) carta geologica del colle di todi. osservatorio di todi e orvieto. brugnoli e., monteverdi c.m., lauteri m., augusti a., scartazza a. (2000) la composizione 13c/12c negli anelli annuali degli alberi della foresta fossile di dunarobba. in: comune di avigliano umbro (ed.) la foresta fossile di dunarobba, contesto geologico e sedimentario. la conservazione e la fruizione. atti del convegno internazionale (avigliano umbro 22-24 aprile 1998). ediart, todi, 135-139. capellini g. (1888) sui resti di mastodon arvernensis recentemente scoperti a spoleto, pontremoli e castrocaro. memorie della regia accademia delle scienze, 4 (9). cappuccino f., argenti p., baldanza a. (2006) la fauna a mammiferi della collezione toni: i mastodonti. in: mattioli b. (ed.) miniere di lignite in umbria. quaderni del laboratorio di scienze della terra, 23, 24-34, graficarte spoleto. catt j.a. (1990) paleopedology manual. quaternary international, 6, 1-95. cerquaglia z. (ed.) (1996) la foresta fossile di dunarobba. ediart, 106 pp., todi. cherin m., bizzarri r., buratti n., caponi t., grossi f., kotsakis t., pandolfi l., pazzaglia f., barchi m.r. (2012) multidisciplinary study of a new quaternary mammal-bearing site from ellera di corciano (central umbria, italy): preliminary data. rendiconti online della società geologica italiana, 21, 1075 -1077. cherin m., iurino d.a., sardella r., rook l. (2014) acinonyx pardinensis (carnivora, felidae) from the early pleistocene of pantalla (italy): predatory behavior and ecological role of the giant pliopleistocene cheetah. quaternary science reviews, 87(1), 82-97. ciangherotti a.d., esu d., girotti o. (1998) review of the history of the late neogene and early quaternary non-marine molluscs of italy. in van kolfschoten th. & gibbard p.l. (eds), proceedings symposium seqs-euromam 1996. mededelingen nederlands instituut voor toegepaste geowetenschappen tno, 60, 491-497. cohen k.m., gibbard p. (2011) global chronostratigraphical correlation table for the last 2.7 million years. subcommission on quaternary stratigraphy (international commission on stratigraphy), cambridge, england. collinson m.e. (1983) accumulation of fruits and seeds in three small sedimentary environments and their palaeoecological implications. annals of botany, 52, 583-592. coltorti m., pieruccini p. (1997) the southeastern tiber basin (spoleto, central italy): geology and stratigraphy of plio-pleistocene sediments. il quaternario, 10, 159-180. combourieu-nebout n. (1993) vegetation response to upper pliocene glacial/interglacial cyclicity in the central mediterranean. quaternary research, 40, 228-236. conti m.a., esu d. (1981) considerazioni sul significato paleoclimatico e geodinamico di una serie lacustre pleistocenica inferiore presso tavernelle (perugia, umbria). geografia fisica e dinamica quaternaria, 4, 3-10. conti m.a., girotti o. (1978) il villafranchiano nel "lago tiberino", ramo sud-occidentale: schema stratigrafico e tettonico. geologica romana, 16, 67-80. corvetti s. (2004) l’ittiofauna fossile del bacino lignitifero di pietrafitta (pleistocene inferiore perugia). unpublished degree thesis, university of perugia, italy. cour p. (1974) nouvelle technique de détection des flux et de retombées polliniques: étude de la sédimentation des pollens et des spores à la surface du sol. pollen et spores, 16, 103-141. csaszar g., kazmer m., erdei b., magyar i. (2009) a possible late miocene fossil forest paleopark in hungary. notebooks in geology, 3, 11. de raaf, j.f.m., boersma, j.r., van gelder, a. (1977) wave-generated structures and sequences from a shallow marine succession, lower carboniferous, county cork, ireland. sedimentology, 24, 451483. delfino m., gentili s., kotsakis t. (2004) the last occurrence of latonia (anura: discoglossidae) and the early pleistocene herpetofauna of pietrafitta (central italy). abstract 32nd congress of geology, florence, 707. dieffenbacher-krall a.c., halteman w.a. (2000) the relationship of modern plant remains to water depth in alkaline lakes in new england. journal of paleolimnology, 24, 213-339. dolezych m., van der burgh j. (2004) xylotomische untersuchungen an inkohlten hölzern aus dem braunkohlentagebau berzdorf (oberlausitz, deutschland). feddes repertorium, 115, 397-437. dunwiddie p.w. (1987) macrofossil and pollen representation of coniferous trees in modern sediments from washington. ecology, 68, 1-11. erdei b., dolezych m., hably l. (2009) the buried miocene forest at bukkabrany, hungary. review of palaeobotany and palinology, 155 (2009), 6779. erdei b., magyari e. (2011) late miocene forest at bukkabrany, hungary. studia botanica hungarica, 42, 135-151. esu d., girotti o. (1974) la malacofauna continentale del plio-pleistocene dell'italia centrale. geologica romana, 13, 203-293. esu d., girotti o. (1991) late pliocene and pleistocene assemblages of continental molluscs in italy. a survey. il quaternario, 4(1a), 137-150. esu d., girotti o., kotsakis t. (1993) palaeobiogeographical observations on villafranchian conti 65 plant record of dunarobba and pietrafitta sites nental molluscs of italy. in janssen a.w. & janssen r. (eds.), proceedings of the symposium "molluscan palaeontology" (11th international malacological congress, siena, italy, 30th august 5th september 1992). scripta geologica, special issue 2, 101-119. ferretti m.p. (1999) mammuthus meridionalis (mammalia, proboscidea, elephantidae) from the "sabbie gialle" of oriolo (cava la salita, faenza, northern italy) and other european late populations of southern mammoth. eclogae geologicae helveticae, 92, 503-515. findlen p. (1997) possedere la natura. in: basso peressut l. (ed.), stanze delle meraviglia. i musei della natura tra storia e progetto. clueb, bologna, 25-47. fischer t.c., butzmann r. (2000) die neogene flora von meleto (valdarno, italien). paläobotanik, paläoökologie und paläoklima. flora tertiaria mediterranea, 5(6), 1-186. follieri m. (1977) evidence on the plio-pleistocene palaeofloristic evolution in central italy. rivista italiana di paleontologia e stratigrafia, 83, 925930. fusco f. (2007) vegetation response to early pleistocene climatic cycles in the lamone valley (northern apennines, italy). review of palaeobotany and palynology, 145, 1-23. gemina (1962) ligniti e torbe dell’italia continentale. gemina, geomineraria nazionale, roma, 320 pp. gentili s. (1991) studio dei caratteri tafonomici nelle associazioni a vertebrati dei depositi pliopleistocenici umbri: il bacino di pietrafitta. borsa di studio in "sedimentologia e stratigrafia delle formazioni plio-pleistoceniche". cnr, roma, 37 pp. gentili s., abbazzi l., masini f., ambrosetti p., argenti p., torre d. (1996) voles from the early pleistocene of pietrafitta (central italy, perugia). acta zoologica cracoviensia, 39(1), 185-199. gentili s., ambrosetti p., argenti p. (1997) large carnivore and other mammal fossils from the early pleistocene alluvial plain of the tiberino basin (pantalla, central italy. preliminary reports. bollettino della società paleontologica italiana, 36(2), 231-238. gentili s., barili a., ambrosetti p. (2000a) lignites, fossils and miners! a paleontological heritage at pietrafitta (perugia, central italy). museologia scientifica, 16(1), 27-40. gentili s., barili a., ambrosetti p. (2000b) un museo per i fossili di pietrafitta. nuova museologia, 2, 1617. gentili s., barili a., meschini p. (2003) un museo aperto (all’aperto) per la miniera delle meraviglie di pietrafitta (perugia, italia centrale). museologia scientifica, 19(1), 35-47. gentili s., masini f. (2005) an outline of italian leptobos and a first sight on leptobos aff. vallisarni from pietrafitta (early pleistocene, perugia). quaternaire, hors-série 2, 81-89. gentili s., mottura a., rook l. (1998) the italian fossil primate record: recent finds and their geological context. geobios, 31(5), 675-686. gibbard p.l., head m.j., walker m.j.c. & the subcommission on quaternary stratigraphy (2010) formal ratification of the quaternary system/period and the pleistocene series/epoch with a base at 2.58 ma. journal of quaternary science, 25, 96102. girotti o., capasso barbato l., esu d., gliozzi e., kotsakis t., martinetto e., petronio c., sardella r., squazzini e. (2003) the section of torre picchio (terni, umbria, central italy): a villafranchian site rich in vertebrates, molluscs, ostracods and plants. rivista italiana di paleontogia e stratigrafia, 109 (1), 77-99. gliozzi e., abbazzi l., argenti p., azzaroli a., caloi l., capasso-barbato l., di stefano g., ficcarelli g., kotsakis t., masini f., mazza p., mezzabotta c., palombo m.r., petronio c., rook l., sala b., sardella r., torre d., zanalda e. (1997) biochronology of selected mammals, mollusc and ostracods from the middle pliocene to the late pleistocene in italy. the state of the art. rivista italiana di paleontologia e stratigrafia, 103, 368-388. greatrex p.a. (1983) interpretation of macrofossil assemblages from surface sampling of macroscopic plant remains in mire communities. journal of ecology, 71, 773-791. gregor h.-j., hottenrott m., knobloch e., planderova e. (1989) neue megaund mikrofloristische untersuchungen in der juntertiären molasse bayerns. geologica bavarica, 94, 281-369. grimm, g.w., denk, t. (2012) reliability and resolution of the coexistence approach a revalidation using modern-day data. review of palaeobotany and palynology, 172, 33-47. gryc v., sakala j. (2010) identification of fossil trunks from bükkabrany newly installed in the visitor centre of the ipolytarnòc fossil nature reserve (novohrad nograd geopark) in the northern hungary. acta universitatis agriculturae et silviculturae mendelianae brunensis, 58 (5), 117-122. guillet s. & planchais n. (1969) note sur une technique d'extraction des pollens des sols par une solution dense. pollen et spores, 11, 141-145. hodgson j.m. (1978) soil sampling and soil description. clarendon press, oxford. hou h.-y. (1983) vegetation of china with reference to its geographical distribution. ann. missouri bot. gard., 70, 509-548. iaccarino, s., premoli silva, i. (2007) practical manual of neogene planktonic foraminifera. international school on planktonic foraminifera, vi course: neogene, perugia, feb. 19-23, 2007, pp 142. jacobacci a., bergomi c., centamore e., malatesta a., malferrari n., martelli g., pannuzzi l., zattini n. (1970) note illustrative della carta geologica d'italia alla scala 1:100000; fogli 115 "città di castello", 122 "perugia", 130 "orvieto". servizio geologico d'italia, 151 p. kàzmér m. (2008) the miocene bükkábrány fossil forest in hungary field observations and project outline. in galácz, a. (ed.): 125th anniversary of the department of palaeontology at budapest university a jubilee volume. hantkeniana, 6, martinetto e. et al. 66 229-244. kotsakis t., gregori l. (1985) i resti di emys orbicularis (linnaeus) (emydidae, testudinata) del pleistocene inferiore di pietrafitta (perugia, italia centrale). geologica romana, 24, 1-12. kraus m.j. (1999) paleosols in clastic sedimentary rocks: their geologic applications. earth-science reviews, 47, 41-70. kottek m., grieser j., beck c., rudolf b., rubel f. (2006) world map of the köppen-geiger climate classification updated. meteorologische zeitschrift, 15, 259-263. lona f., bertoldi r. (1972) la storia del pliopleistocene italiano in alcune sequenze lacustri e marine. memorie dell’ accademia nazionale dei lincei, 8, 1-47. lona f., bertoldi r., ricciardi e. (1969) pliopleistocene boundary in italy based on the leffian and tiberina vegetational and climatological sequences. coll. vii inqua congress, sect. stratigraphy, paris, 573-574. lotti b. (1917) l'antico lago tiberino e le ligniti dell'umbria. miniera italiana, 1, 274-275. lotti b. (1926) descrizione geologica dell'umbria. memorie per la descrizione della carta geologica d’italia, 21, 320 p. machette n.m. (1985) calcic soils of the southwestern united states. in: soils and quaternary geology of the southwestern united states (ed. d.l. weide), geol. soc. am. spec. pap., 203, 10-21. magri d., di rita f., palombo m.r. (2010) an early pleistocene dynamics of central italy (scoppito, l’aquila). quaternary international, 267, 30-39. magri d., palombo m.r. (2013) early to middle pleistocene dynamics of plant and mammal communities in south west europe. quaternary international, 267, 30-39. mai d.h., walther h. (1988) die pliozänen floren von thüringen, deutsche demokratische republik. quartärpaläontologie, 7, 55-297. martini i.p., sagri m. (1993) tectono-sedimentary characteristics of the late miocene-quaternary extensional basins of the northern apennines, italy. earth-science reviews, 34, 197-233. manganelli g., benocci a., esu d., giusti f. (2008) staurodon cianfanellianus n. sp. (gastropoda pulmonata), a new nesopupine vertiginid snail from the middle-late pliocene fossil forest of dunarobba (central italy). bollettino della società paleontologica italiana, 47(3), 211-214. manganelli g., delle cave l., giusti f. (1989) notulae malacologicae, xlii. strobilopsidae (gastropoda, pulmonata), a family new to the villafranchian land snail fauna of apenninic italy. basteria, 53, 3-13. manganelli g., giusti f. (2000) the gastrocoptids of the fossil forest of dunarobba (central italy) and a preliminary revision of the european tertiary nominal species of albinula and vertigopsis (gastropoda pulmonata: gastrocoptidae). bollettino della società paleontologica italiana, 39(1), 55-82. manganelli g., giusti f., delle cave l. (1990) notulae malacologicae, xlviii. lauriinae (gastropoda: pulmonata, orculidae/pupillidae) from the villafranchian of the peninsular italy. basteria, 54, 87103. martel a.t., gibling m.r. (1994) combined-flow generation of sole structures, including recurved groove casts, associated with lower carboniferous lacustrine storm deposits in nova scotia, canada. journal of sedimentary research, a64, 508-517. martinetto e. (1994) paleocarpology and the "in situ" ancient plant communities of a few italian pliocene fossil forests. in: matteucci r., carboni m.g. & pignatti j.s. (eds) studies on ecology and paleoecology of benthic communities. bollettino della società paleontologica italiana, spec. vol. 2, 189196. martinetto e. (1995) significato cronologico e paleoambientale dei macrofossili vegetali nell'inquadramento stratigrafico del "villafranchiano" di alcuni settori del piemonte (italia nw). phd. thesis, university of turin, italy. martinetto e. (1996) relazione sull’analisi paleocarpologica di depositi continentali del bacino tiberino e di pietrafitta. in: cerquaglia z. (ed.) la foresta fossile di dunarobba. ediart, todi, 87-95. martinetto e. (1999) chronological framing of pliocene to early pleistocene plant macrofossil assemblages from northern italy. acta palaeobotanica, supplement 2, 503-511. martinetto e. (2000) paleocarpologia dei depositi continentali di dunarobba. in: la foresta fossile di dunarobba contesto geologico e sedimentario la conservazione e la fruizione. atti del convegno internazionale (avigliano umbro, 22-24 aprile 1998). ediart, todi, 107-109. martinetto e. (2001) the role of central italy as a centre of refuge for thermophilous plants in the late cenozoic. acta palaeobotanica, 41(2), 299-319. martinetto, e., festa, c. (2013) frutti e semi fossili del biellese. docbi studi e ricerche sul biellese, 2013, 169-188. martinetto e., monegato g., irace a., vaiani s.c., vassio e. (in press) pliocene and early pleistocene carpological records of terrestrial plants from the southern border of the po plain (n-italy). review of palaeobotany and palynology. martinetto e., monegato g., vassio e. (2012) an early pleistocene plant assemblage with east european affinity in the venetian-friulian basin (ne italy). alpine and mediterranean quaternary, 25 (2), 91104. martinetto e., scardia g., varrone d. (2007) magnetobiostratigraphy of the stura di lanzo fossil forest succession (piedmont, italy). rivista italiana di paleontologia e stratigrafia, 113(1), 109-125. martinetto e., vassio e. (2010) reconstructing "plant community scenarios" by means of palaeocarpological data from the cenofita database, with an example from the ca’ viettone site (pliocene, northern italy). quaternary international, 225, 2536. martini i.p., sagri m. (1993) tectono-sedimentary characteristics of late miocene quaternary extensional basins of the north appennines, italy. 67 plant record of dunarobba and pietrafitta sites earth science review, 34, 197-223. mazza p., sala b., fortelius m. (1993) a small latest villafranchian (late early pleistocene) rhinoceros from pietrafitta (perugia, umbria, central italy), with notes on the pirro and westerhoven rhinoceros. palaeontographia italica, 80, 25-50. medici m.c., gliozzi e. (2008) preliminary data on the freshwater ostracods from the middle-late pliocene tiberino "palaeo-ancient lake" (umbria, central italy). atti museo civico di storia naturale trieste, suppl., 53, 39-48. melamed y., kislev m., weiss e., simchoni o. (2011) extinction of water plants in the hula valley: evidence for climate change. journal of human evolution, 60 (2011), 320-327. melelli l., barchi m., brozzetti f., lupattelli a., mirabella f., pazzaglia f., pucci s., saccucci l. (2010) morphotectonic evolution of high tiber valley (umbria, italy) related to an active low angle normal fault segmentation. rendiconti online della società geologica italiana, 11, 629-630. menchi g., matteoli u., staccioli g. (1997) changes in the acid structure of wood due to ageing and fossilisation processes. wood science and technology, 31, 391-397. meneghini m., paganelli a. (1994). the fossil forest of dunarobba (umbria central italy): palaeoforestry history through a palynological study. biogeographia, 17, 101-11. napoleone g., albianelli a., azzaroli a., bertini a., magi m., mazzini m. (2003) calibration of the upper valdarno basin to the plio-pleistocene for correlating the apennine continental sequences. ii quaternario (italian journal of quaternary sciences) 16 (1bis), 131-166. nowak j., nowak d., chevallier p., lekki j., van grieken r., kuczumow a. (2007) analysis of composite structure and primordial wood remains in petrified wood. applied spectroscopy, 61(8), 889-895. numata m. (ed.) (1974) the flora and vegetation of japan. elsevier. paganelli a., solazzi a. (1962) analisi pollinica sul deposito pleistocenico di pietrafitta (umbria). rendiconti degli istituti scientifici dell’università di camerino, 3(1), 64-89. palanti s., susco d., torniai a.m. (2004) the resistance of dunarobba fossil forest wood to decay, fungi and insect colonization. international biodeterioration & biodegradation, 53, 89-92. pantanelli d. (1886) vertebrati fossili nelle ligniti di spoleto. atti della società toscana di scienze naturali, 7, 1. pauselli o. (2003) macroresti vegetali in sedimenti lacustri pliocenici dell’umbria meridionale. evidenze paleoecologiche, paleoclimatiche e cronostratigrafiche. unpublished degree thesis, università di perugia, 95 pp. pazzaglia f. (2007) evoluzione tettonico-sedimentaria dei bacini quaternari minori tra la val di chiana e il bacino tiberino. ph.d. thesis, università di perugia. pazzaglia f., barchi m.r., buratti n., cherin m., pandolfi l., ricci m. (2013) pleistocene calcareous tufa from the ellera basin (umbria, central italy) as a key for an integrated paleoenvironmental and tectonic reconstruction. quaternary international, 292, 59-70. petronio c., anzidei a. p., bedetti c., bona f., di canzio e., gentili s., mazza p., palombo m.r., pavia m., salari l., sardella r., tintori a. (2005) le faune a mammiferi del plio-pleistocene. memorie del museo civico di storia naturale di verona 2. serie, scienze della terra 6, 183-218. petronio c., argenti p., caloi l., esu d., girotti o., sardella r. (2002) updating villafranchian mollusc and mammal faunas of umbria and latium (central italy). geologica romana, 36, 369-387. pialli g., plesi g., damiani a.v., brozzetti f., boscherini a., bucefalo palliani r., cardinali m., checcucci r., daniele g., galli m., luchetti l., motti a., nocchi m., ponziani f., rettori r. (2009) note illustrative del foglio 289 "città di castello" della carta geologica d'italia alla scala 1:50000. servizio geologico d'italia, 142 pp. plesi g., arcaleni a., bartoccini p., boscherini a., botti f., checucci r., damiani a.v., daniele g., del gaia f., felicioni g., galli m., luchetti l., motti a., palandri f., ponziani f., preziosi e., rettori r., sabatini s., simone g., tosti s., tuscano f., uffreduzzi t., merangola s. (2010) note illustrative del foglio 299 "umbertide" della carta geologica d'italia alla scala 1:50000. servizio geologico d'italia, 144 pp. pontini m.r. (1997) analisi palinologica e interpretazione paleo climatica dei depositi continentali del bacino tiberino (umbria, italia). unpublished ph.d thesis, university of perugia, 134 p. pontini m.r., albianelli a., basilici g., bertini a., napoleone g. (2002) pollen record and magnetostratigrapy of the middle-late pliocene lacustrine sequence in the tiberino basin (central italy). bollettino della società geologica italiana, special volume 1-2002, 467-472 pontini m.r., bertini a. (2000) late pliocene vegetation and climate in central italy: high resolution pollen analysis from the fosso bianco section (tiberino basin). geobios, 33(5), 519-526. principato m., principato m.s. (2000) rilievi entomologici nella foresta fossile di dunarobba. in: la foresta fossile di dunarobba contesto geologico e sedimentario la conservazione e la fruizione. atti del convegno internazionale (avigliano umbro, 22-24 aprile 1998). ediart, todi, 119-128. ravazzi c., rossignol strick m. (1995) vegetation change in a climatic cycle of early pleistocene age in the leffe basin (northern italy). palaeogeography, palaeoclimatology, palaeoecology, 117, 105-122. regione umbria (2005) progetto di cartografia geologica e geotematica a scala 1:10000: individuazione delle aree suscettibili di amplificazioni sismiche locali sui territori comunali con elevata pericolosità sismica di base. regione umbria, 40 pp., perugia. regione umbria (2010) progetto di microzonazione sismica delle aree urbane 1° intervento: città di martinetto e. et al. 68 perugia. regione umbria, 40 pp., perugia. retallack g.j. (2001) soil of the past: an introduction to paleopedology. allen and unwin, 404 pp., london. retallack g.j. (2005) pedogenic carbonate proxies for amount and seasonality of precipitation in paleosols. geology, 33, 333-336. ricciardi e. (1961) analisi pollinologica dei sedimenti lacustri lignitiferi di pietrafitta (perugia, italia). pollen et spores, 3, 2,325-328. rio d., raffi i., villa g. (1990) pliocene-pleistocene calcareous nannofossil distribution patterns in the western mediterranean. in: kastens k. & mascle j. (eds.), proceedings odp science results, 107, 513-533. rook l. (1995) pannonictis nestii (carnivora, mammalia) from the late villafranchian of pietrafitta (umbria, italy). preliminary note. eclogae geologicae helveticae, 88, 853-864. rustioni m., mazza p. (1993) the late villafranchian bear from pietrafitta (perugia, central italy). palaeontographia italica, 80, 51-62. sadori l., giardini m., chiarini e., mattei m., porreca m., papasodaro f. (2010) pollen and macrofossil analyses of pliocene lacustrine sediments (salto river valley, central italy). quaternary international, 225, 44-57. sardella r., di stefano g., petronio c. (1995) the villafranchian mammal faunas from the tiber river basin (umbria, central italy). il quaternario, 8, 509-514. satoo t. (1983) temperate broad-leaved evergreen forests of japan. in: ovington j. d. (ed.) temperate broad-leaved evergreen forests. elsevier. scott a.c., collison m.e. (2003) non destructive multiple approaches to interpret the preservation of plant fossils: implications forcalcium-rich permineralizations. journal of the geological society, 160, 857-862. scott a.c., freedberg d. (2000) fossil woods and other geological specimens. harvey miller, 424 pp. simonetti s. (1998) analisi palinologica ed interpretazione paleoambientale dei depositi continentali pliocenici di dunarobba, nel bacino tiberino (umbria). unpublished thesis of laurea, università di perugia, 167 pp. sorbini l., 1990. comunicazione. in: aa. vv. (eds), salvaguardia dell’ambiente e conservazione dei beni paleontologici. bollettino della società paleontologica italiana. spicer r.a., wolfe j.a. (1987) taphonomy of holocene deposits in trinity (clair engle) lake, northern california. paleobiology, 13, 227-245. staccioli g., bartolini g. (1997) new biomarkers of the extinct species taxodioxylon gypsaceum. wood science and technology, 31, 311-315. staccioli g., fratini f., meli a., lazzeri s. (2001) mineralization processes in some samples from fossil forest of dunarobba (umbria, central italy). wood science and technology, 35, 353-362. staccioli g., menchi g., matteoli u., seraglia r., traldi p. (1996) chemotaxonomic observations on some pliocenic woods from arno basin and fossil forest of dunarobba (italy). flora mediterranea, 6, 113-117. teodoridis v., gregor h.j. (2001) a new pliocene leaf flora from the meleto clay in the opencast mine santa barbara, upper valdarno (central tuscany, italy). flora tertiaria mediterranea, 5(11), 1-28. teodoridis v., sakala j. (2008) early miocene conifer macrofossils from the most basin (czech republic). neues jahrbuch für geologie und paläontologie, abhandlungen, 250(3), 287-312. thomasson j.r. (1991) sediment-borne ‘‘seeds’’ from sand creek, northwestern kansas: taphonomic significance and paleoecological and paleoenvironmental implications. palaeogeography, palaeoclimatology, palaeoecology, 85, 213-225. urban b., arias c., bigazzi g., bonadonna f. (1983). early pleistocene palynostratigraphy of fornace tini, valle ricca (central italy). palaeogeography, palaeoclimatology, palaeoecology, 41(1-2), 153164. vassio e., martinetto e. dolezych m., van der burgh j. (2008) wood anatomy of the glyptostrobus europaeus "whole-plant" from a pliocene fossil forest of italy. review of palaeobotany and palynology, 151, 81-89 velichkevich f.y., zastawniak e. (2003) the pliocene flora of kholmech, south-eastern belarus and its correlation with other pliocene floras of europe. acta palaeobotanica, 43(2), 137-259. velichkevich f.y., zastawniak e. (2006) atlas of the pleistocene vascular plant macrofossils of central and eastern europe. part i pteridophytes and monocotyledons. w. szafer institute of botany, polish academy of sciences, 224 pp., kraków. velichkevich f.y., zastawniak e. (2008) atlas of the pleistocene vascular plant macrofossils of central and eastern europe. part ii herbaceous dicotyledons. w. szafer institute of botany, polish academy of sciences, 380 pp., kraków. verducci e. (1959) ricerche lignitifere nel lago tiberino tra todi e narni. atti del convegno: mostra nazionale delle ligniti (perugia, 7-11 maggio 1959), pp. 66-77. vergoni s. (2000) la foresta fossile di dunarobba. stato dei lavori per la conservazione e la tutela. in: comune di avigliano umbro (ed.) la foresta fossile di dunarobba, contesto geologico e sedimentario. la conservazione e la fruizione. atti del convegno internazionale (avigliano umbro 22-24 aprile 1998). ediart, todi, 196-204. verri a. (1879) avvenimenti nell'interno del bacino del tevere antico durante e dopo il periodo pliocenico. atti della società italiana di scienze naturali, 21, 149-180. verri a. (1901) un capitolo della geografia fisica dell'umbria. atti 4° congresso geografico italiano, roma. stabilimento tipografico bellini, 24 pp., milano. wang c.-w. (1961) the forests of china with a survey of grassland and desert vegetation. maria moores cabot foundation publ. ser. 5, havard univ., 313 pp., cambridge, massachussets. williams c.j., mendell e.k., murphy j., court w.m., 69 plant record of dunarobba and pietrafitta sites ms. received: june 14, 2014 final text received: july 20, 2014 johnson a.h., richter s.l. (2008) paleoenvironmental reconstruction of a middle miocene forest from the western canadian arctic. palaeogeography, palaeoclimatology, palaeoecology, 261, 160176. wolfe j.a. (1971) tertiary climatic fluctuations and methods of analysis of tertiary floras. palaeogeography, palaeoclimatology, palaeoecology, 9, 27-57. wright v.p. (1989) paleosol recognition. in: paleosols in siliciclastic sequences (eds j.r.n. allen and v.p. wright. postgraduate research institute for sedimentology, university of reading, reading), 1 -25. zagwijn w.h. (1963) pollen analytical investigations in the tiglian of the netherlands. mededelingen van de geologische stichting, 16, 49-71. zagwijn w.h. (1974) the pliocene-pleistocene boundary in western and southern europe. boreas, 3, 75-97. zagwijn w.h. (1996) borders and boundaries: a century of stratigraphical research in the tegelen reuver area of limburg (the netherlands). abstract symposium inqua-seqs '96 'the dawn of the quaternary', kerkrade, 2-7. zagwijn w.h. (1990) subtropical relicts in the pliocene flora of brunssum (the netherlands). geologie en mijnbouw, 69, 219-225. zucchetta g., gentili s., pavia m. (2003) a new early pleistocene bird association from pietrafitta (perugia, central italy). rivista italiana di paleontologia e stratigrafia, 109(3), 527-538. martinetto e. et al. 70 appendix 1 informal palyno-groups used in the summary pollen diagrams of figures 3-5 and 18 palyno-group 1 mega-mesothermic elements. taxodium type is the main component (plus rare pollen grains of sequoia -type and sciadopitys); nyssa, arecaceae, engelhardia, myrica, distylium and other hamamelidaceae tricolpate pollen grains are subordinated. palyno-group 2 mesothermic elements requiring a humid climate but tolerating seasonal contrast in humidity and temperature. quercus is the principal component. juglandaceae (juglans, carya, pterocarya), liquidambar, ilex, carpinus, castanea, ulmus, tilia, acer, fraxinus, viburnum, araliaceae (panax type) and celtis are subordinated. the mediterranean evergreens, represented by only few pollen grains of quercus ilex-type, olea, and pistacia, are included in this palyno-group. palyno-group 3 cathaya plus pinus haploxylon-type. cathaya is a se asian gymnosperm tolerating low temperature but requiring an high humidity along all the year. palyno-group 4 pinus and undetermined pinaceae saccate pollen grains, with variable ecological and climatic requirements. palyno-group 5 meso-microthermic conifers such as cedrus and tsuga. palyno-group 6 microthermic elements such as abies and picea plus fagus and betula. palyno-group 7 undetermined and indeterminable pollen grains as well as elements with local significance such as alnus and salix plus cupressaceae. palyno-group 8 non arboreal elements, principally herbs such as poaeeae, asteraceae (except artemisia), amaranthaceae, ericaceae, ranunculaeeae (thalictrum), brassicaceae, caryophyllaceae, plantaginaceae, lamiaceae, cf. fabaceae, polygonaceae (rumex), plumbaginaceae (armeria). palyno-group 9 steppic taxa such as artemisia and ephedra. 71 plant record of dunarobba and pietrafitta sites appendix 2 palyno-floral list for the plio-pleistocene sites of the tiberino basin legend: ct i, cava toppetti i section; ct ii, cava toppetti ii section; du, dunarobba sections; fb, fosso bianco section; pf, pietrafitta section. martinetto e. et al. 72 base burial dating of late-cenozoic deposits using in-situ produced cosmogenic nuclides 1andrea ciampalini, 2cristina persano, 2derek fabel, 1marco firpo 1dipartimento per lo studio del territorio e delle sue risorse, genova 2department of geographical and earth science, university of glasgow corresponding author: a. ciampalini <andrea.ciampalini@dipteris.unige.it> riassunto: ciampalini a. et al. calcolo dell’età di seppellimento di depositi tardo-cenozoici attraverso gli isotopi cosmogenici. (it issn 0394-3356, 2010) la datazione di depositi fluvio-deltizi neogenico-quaternari è spesso difficile a causa della mancanza, al loro interno, di biomarkers stratigrafici. definire un intervallo temporale preciso in cui è avvenuta la deposizione dei sedimenti che si ha intenzione di analizzare risulta fondamentale in molti campi della geologia, geomorfologia, stratigrafia e geoarcheologia. lo studio di questi depositi è fondamentale per comprendere l’evoluzione del paesaggio in termini di erosione, incisione fluviale e tassi di deposizione in conseguenza di attività tettonica o cambiamenti climatici. le tecniche di datazione tradizionali o più utilizzate come la termoluminescenza o il 14c su materiale organico hanno un limite temporale piuttosto ristretto e risultano inutilizzabili in caso di sedimenti più vecchi del pleistocene superiore. per sedimenti più vecchi e/o in mancanza di sostanze organiche, gli isotopi cosmogenici trovano una più vasta applicabilità, non solo per la datazione dei sedimenti, ma anche in numerosi altri settori della geologia. verrà di seguito illustrata la procedura di preparazione dei campioni e la teoria del metodo degli isotopi cosmogenici, evidenziando le caratteristiche necessarie per applicare il metodo e illustrando la versatilità dello stesso per risolvere problematiche molto differenti fra loro. abstract: ciampalini a. et al. burial dating of late-cenozoic deposits using in-situ produced cosmogenic nuclides. (it issn 03943356, 2010) dating the miocene to pleistocene deposition of fluvial and deltaic sediments is often difficult because of the absence of suitable biostratigraphic markers. temporal limits on sediment deposition, however, are fundamental constraints in many geological, geomorphological, stratigraphical and archeological studies. in particular a dated stratigraphy of sedimentary basins provides information about timing of evolution of the sediment source and routing system due to tectonics, sea-level and/or climate changes. traditional techniques, such as luminescence, radiocarbon dating of organic material, etc. only permit us to date sediments that are no older than ~250,000 years. recently a method for dating sediment burial using the radioactive decay of cosmogenic nuclides 26al and 10be has been developed. 26al and 10be are produced by the continuous bombarding by high-energy cosmic rays of the earth surface where they penetrate into rocks and sediments at a depth that varies, depending on rock density, between 2 and 3 m. the long half-life of the 26al (7.05x105 yr) and 10be (1.5x106 yr) make them optimal for dating sediments that were deposited over the past five million years, as long as the sediments were at the surface and exposed to cosmic rays before sedimentation and burial. the sediments that can be dated using the cosmogenic isotopes technique need to have the following characteristics: (1) quartz needs to be present and have been exposed at the surface for a time necessary to accumulate measurable cosmogenic radionuclides concentration (i.e., depending on latitude and altitude, at least ~ 200 years); (2) transport time needs to have been negligible (3) burial was rapid and deep (>10 m) to avoid cosmogenic nuclides production after deposition, otherwise a correction needs to be introduced. this method is useful in many italian areas where deltaic or fluvial miocene to pleistocene deposits crop out. parole chiave: nuclidi cosmogenici; età di seppellimento; tassi di erosione; età di esposizione; raggi cosmici. keywords: cosmogenic nuclides; burial dating; erosion rates; exposure age; cosmic rays. il quaternario italian journal of quaternary sciences 23(1), 2010 125-136 1. introduzione l’utilizzo dei nuclidi cosmogenici terrestri è legato alla misurazione della concentrazione di tali isotopi che si sono accumulati nelle rocce o nei sedimenti a causa dell’interazione fra la radiazione cosmica e la superficie terrestre. davis & schaffer nel 1955 furono i primi ad utilizzare i nuclidi cosmogenici terrestri (nct) prodotti nei minerali che si trovano sulla superficie terrestre per risolvere problematiche connesse alla geologia. prima di allora erano stati analizzati solamente campioni provenienti da meteoriti e dalla superficie lunare (reedy et al., 1983). le tecniche che i ricercatori avevano a disposizione per misurare le concentrazioni dei nuclidi cosmogenici non permettevano ancora di poter analizzare campioni terrestri in quanto, in questi ultimi, la concentrazione di tali nuclidi era troppo bassa per la risoluzione degli strumenti di allora. le piccole concentrazioni di nuclidi cosmogenici presenti nelle rocce terrestri divennero misurabili a partire dai primi anni ’80 con lo sviluppo di tecnologie più avanzate: l’acceleratore di massa (ams) e lo spettrometro di massa convenzionale per i gas nobili. da allora sono state sviluppate due principali metodologie che prevedono l’utilizzo dei nct. la prima prevede la datazione di superfici esposte mentre la seconda permette di determinare i tassi di erosione o meglio il tempo necessario per erodere una superficie di ~1-2 metri di spessore. recentemente è stata sviluppata una terza applicazione che, sfruttando il diverso tasso di produzione e decadimento dei radionuclidi, permette di datare l’età di seppellimento di una superficie, sia essa costituita da roccia o sedimenti (granger & muzikar, 2001). la datazione di superfici esposte è stata la prima applicazione (e.g. davis & 126 a. ciampalini et al. schaffer) ed è ancora oggi la metodologia più utilizzata. in realtà il concetto di nuclidi cosmogenici terrestri risale al 1912 quando hess formulò una propria teoria che riguardava il comportamento dei raggi cosmici. questa teoria venne ripresa nel 1934 da grosse il quale osservò che quando i raggi cosmici raggiungevano la superficie terrestre scatenavano delle reazioni fisiche che davano origine a nuclidi cosmogenici che chiamò elementi radio-cosmici. nel 1949 libby realizzò che era possibile misurare la quantità di 14c prodotta dall’interazione tra i raggi cosmici e l’atmosfera. nel 1955 davis & schaffer datarono l’età di esposizione di una superficie in roccia nelle montagne rocciose abbandonata dal ritiro del ghiacciaio dopo l’ultimo glaciale, misurando la concentrazione del 36cl. a partire dal 1960, alcuni studi di fisica illustrarono come i raggi cosmici interagissero con il campo magnetico terrestre e con l’atmosfera, evidenziando come il tasso di produzione dei nuclidi cosmogenici variasse al variare della quota e della latitudine. infine negli anni ’70 vennero analizzati campioni di meteorite e lunari di cui abbiamo accennato sopra (reedy et al., 1983). poiché la concentrazione dei nuclidi cosmogenici nelle rocce e nei sedimenti è di diversi ordini di grandezza inferiore che nell’atmosfera, è stato necessario attendere l’introduzione dell’ams e dello spettrometro di massa convenzionale per i gas nobili per poterla misurare. grazie a questi strumenti è stato possibile calcolare i tassi isotopici con un errore inferiore al 3%. inoltre l’ams è capace di rilevare rapporti isotopici di 10be, 26al, 14c, 36cl e 129i aventi rapporti atomici con il corrispettivo isotopo stabile dell’elemento in questione dell’ordine di 10-10 e 10-16. lo spettrometro per i gas nobili consente di raggiungere la stessa precisione con il 21ne, ma le quantità minime da analizzare sono molto maggiori. dal 1985 i lavori che riportano analisi isotopiche utilizzando i nct sono aumentati considerevolmente. 2. applicabilita’ del metodo oggi l’impiego di queste metodologie è molto diffuso in tutto il mondo. per esempio i nct sono stati impiegati per ricostruire le variazioni volumetriche dei ghiacci durante il quaternario, datando le superfici di esarazione dei ghiacciai e i depositi morenici continentali (nishiizumi et al., 1991a; gosse et al., 1995a; ivyochs et al., 1995; ackert et al., 1999; zreda et al., 1999) e montani (phillips et al., 1990; gosse et al., 1995b; jackson et al., 1997; moscariello et al., 1998; fabel et al., 2006; yingkui et al., 2008). i nct sono stati utilizzati per datare eventi vulcanici (marti & craig, 1987; phillips et al., 1986; cerling, 1990; nishiizumi et al., 1990; anthony & poths, 1992; licciardi et al., 1999), eventi paleo-sismici (bierman & gillespie, 1994; gosse et al., 1996; ayarbe et al., 1998; zreda & noeller, 1998), tassi di uplift di rocce, di superfici e tassi di incisione (brook et al., 1995; seidl et al., 1997; gosse et al., 1997; leland et al., 1998; barnard et al., 2001; pratt et al., 2002; matsushi et al., 2006; kober et al., 2007). queste metodologie si sono rivelate utili anche per datare eventi o oggetti particolari come i vetri del deserto libico (klein et al., 1986) o il momento dell’impatto del meteorite che ha originato il cratere del canion diablo (nishiizumi et al., 1991b; phillips et al., 1991). l’applicabilità degli isotopi cosmogenici per la datazione di sedimenti spazia dai depositi morenici ai massi erratici, ai block streams (phillips et al., 1990; brown et al., 1991; phillips et al., 1996; 1997; miller et al., 2002; bowen et al., 2002; wilson et al., 2008) ai terrazzi fluviali con annessi depositi (molnar et al., 1994; repka et al., 1997; schaller et al., 2002), agli alluvial fan e debris flow (cerling, 1990; ritz et al., 1995; liu et al., 1996; regard et al., 2006), ai depositi costieri lacustri (trull et al., 1995; balco & schaefer, 2006), fino ai depositi costieri marini (perg et al., 2001). nel campo della geologia strutturale i nct possono essere utili per datare superfici di faglia, tassi di movimento e la ricorrenza di eventi sismici (zreda & noeller, 1998; mitchell et al., 2001; jackson et al., 2002). la datazione di eventi franosi è un altro aspetto della geomorfologia che può essere risolto utilizzando i nct (ballantyne et al., 1998; kubik et al., 1998; barnard et al., 2001). inoltre è possibile anche datare piattaforme di abrasione marina (stone et al., 1996; alvarez-marrón et al., 2008), calcolare i tassi di erosione superficiale di rocce, regoliti e superfici deposizionali (cockburn et al., 1999; summerfield et al., 1999) e tassi di erosione superficiale a scala regionale (riebe et al., 2000; schaller et al., 2001; nichols et al., 2002). utilizzando i nct è possibile calcolare i tassi di movimento verticale e/o orizzontale di materiale nei suoli (heimsath et al., 1999; 2000; phillips, 2000), nelle lateriti (brown et al., 1998; braucher et al., 2000; schoreder et al., 2001), nei depositi di versante (small et al., 1999; heimsath et al., 2002), nei depositi eolici (klein et al., 1986; shepard et al., 1995) e in ambiente desertico (shepard et al., 1995; wells et al., 1995). recentemente i nct sono stati utilizzati anche per datare eventi di seppellimento di superfici, materiali e sedimenti permettendo, quindi, la datazione di depositi molto vecchi, fino a circa cinque milioni di anni (granger & muzikar, 2001; granger et al., 2001; balco & rovey, 2008; ciampalini et al., 2009). 3. teoria del metodo i raggi cosmici vengono originati da diverse sorgenti come il sole, le altre stelle, le stelle a neutroni, i buchi neri, i nuclei galattici attivi e le galassie radio. nella nostra galassia, tali raggi sono prodotti prevalentemente in seguito ad esplosioni di super-novae e, dopo aver attraversato i campi magnetici interplanetari e terrestri, interagiscono con l’atmosfera terrestre. questa interazione produce una cascata di particelle che reagiscono a contatto con l’atmosfera e con la superficie terrestre. l’interazione fra i raggi cosmici ad alta energia e l’atmosfera terrestre da origine alla formazione di raggi cosmici secondari, fra cui neutroni e muoni. il tasso di produzione dei nuclidi cosmogenici è dipendente dal flusso di raggi cosmici il quale, a sua volta, è fortemente influenzato dal campo magnetico terrestre ed è attenuato dall’atmosfera terrestre (lal & peters, 1967; dunai, 2000; 2001; stone, 2000; gosse & phillips 2001). l’influenza del campo magnetico e dell’atmosfera terrestre sono la causa della traiettoria seguita dai raggi cosmici e, quindi, del diverso tasso di produzione a seconda della latitudine e altitudine. infatti il tasso di produzione dei nuclidi cosmogenici è elevato alle alte latitudini, perché i raggi cosmici primari vengono deviati maggiormente all’equatore rispetto ai poli ed è maggiore ad alta quota perché lo spessore di atmosfera attraversato dal flusso dei raggi cosmici secondari è minore. il tasso di produzione è influenzato anche dalla geometria e dalla morfologia del sito di campionamento, in quanto la presenza di montagne circostanti o di una superficie fortemente inclinata possono essere causa di schermatura della superficie che si intende andare ad analizzare. le problematiche appena esposte trovano comunque soluzione nell’applicazione di fattori di correzione che tengono presente della latitudine, altitudine (lal, 1991; stone, 2000), dell’inclinazione della superficie e del profilo dell’orizzonte (dunne et al., 1999). i neutroni generati durante l’interazione fra i raggi cosmici e l’atmosfera o la superficie terrestre possono penetrare per alcuni metri nelle rocce e nei sedimenti (la profondità dipende dalla densità del materiale attraversato). i muoni, invece, possono penetrare per kilometri sotto la superficie terrestre. l’interazione nucleare fra neutroni e muoni con i minerali presenti nelle rocce (quarzo, k-feldspato, olivina, calcite, etc.) produce nuclidi cosmogenici (3he, 10be, 14c, 21ne, 26al e 36cl). esistono tre diversi meccanismi attraverso cui i nuclidi cosmogenici vengono prodotti: spallazione dei neutroni, azione dei muoni lenti e azione dei muoni veloci (gosse & phillips, 2001). nei primi tre metri della crosta terrestre il meccanismo della spallazione è dominante, mentre diventa subordinata agli altri due meccanismi procedendo in profondità. la spallazione avviene quando un neutrone collide con un nucleo bersaglio (templeton, 1953) e separa da esso alcune particelle, lasciando un nucleo più leggero (es. il 28si contenuto nel quarzo si trasforma in 21ne). i muoni risultano dal decadimento di mesoni instabili che vengono prodotti dall’interazione dei raggi cosmici primari con l’atmosfera. la produzione di isotopi cosmogenici attraverso i muoni lenti avviene attraverso reazioni di cattura di muoni negativi, mentre i muoni veloci danno luogo ad una cascata di particelle che, per esempio, producono 26al e 10be anche in profondità (granger & muzikar, 2001). la radiazione derivante dai raggi cosmici è rilevante in quanto determina il tasso di produzione dei nuclidi cosmogenici nelle rocce o nei sedimenti esposti (gosse & phillips, 2001) (tab.1). le incertezze di circa il 10% (20% per il 21ne) sul tasso di produzione degli isotopi cosmogenici derivano da una serie di fattori; in particolare dal fatto che la variazione temporale del flusso di radiazioni cosmiche non è conosciuta con accuratezza. per diminuire tali incertezze si misurano, per ogni campione, due isotopi cosmogenici e se ne considera il rapporto. poiché per un dato campione di roccia o sedimento tutte le variabili che contribuiscono a determinare il tasso di produzione dei nuclidi cosmogenici sono le stesse e influiscono sui vari isotopi nello stesso modo, il rapporto fra due nuclidi cosmogenici è solo influenzato da incertezze analitiche, che di solito non superano il 3%. dal punto di vista del campionamento, la presenza di una superficie orizzontale piatta ad alte latitudini e sul livello del mare rappresenta la condizione ideale per misurare il tasso di produzione dei nuclidi cosmogenici. in ogni altro caso, i tassi di produzione elencati in tabella 1 devono essere corretti per tenere conto della latitudine, altitudine e esposizione del campione ai raggi cosmici (lal, 1991; stone, 2000). simili correzioni devono essere apportate anche ai sedimenti per ricavarne l’età di deposizione (granger & muzikar, 2001). 127burial dating of late-cenozoic deposits ... 4. preparazione del campione la preparazione del campione per la misurazione delle concentrazioni degli isotopi cosmogenici risulta piuttosto lunga e laboriosa. l’obiettivo finale è quello di isolare i nuclidi da analizzare da tutto il resto del campione. viene presentata di seguito la procedura utilizzata per l’estrazione dell’26al e del 10be dal quarzo utilizzata attualmente presso i laboratori dell’università di glasgow e dello scottish universities environmental research centre di east kilbride (uk). la procedura è sostanzialmente composta da due parti, la prima (fig. 1) consiste nella purificazione del campione, ovvero si cerca di isolare il minerale contenente i nuclidi cosmogenici (es. quarzo). la seconda parte (fig. 2) prevede l’estrazione dal quarzo dei nuclidi di cui si vuole misurare la concentrazione. data la loro affinità chimica, l’26al e il 10be si estraggono dal quarzo con la stessa procedura, mentre ogni altro nuclide richiede un approccio diverso. per estrarre l’26al e il 10be da un campione di roccia o di sedimento è necessario, prima di tutto, trattare il campione fino a ridurlo a puro quarzo. altri nuclidi cosmogenici possono essere utilizzati nel caso il quarzo non sia presente; per esempio si può determinare la concentrazione di 36cl in carbonati o di 3he in pirosseni e olivina. dal quarzo è possibile estrarre anche il 21ne. i passaggi per ottenere un campione di quarzo purificato sono numerosi e, non sempre tutti necessari; dipendono dalla purezza iniziale del campione. estrarre quarzo puro da un conglomerato costituito da clasti di quarzo richiede un lavoro minore rispetto, per esempio, ad un campione di micascisto. la separazione del quarzo inizia con la frantumazione del campione, che viene in seguito setacciato con due setacci aventi luce di 250 µm e 500µm al fine di tripartirlo in tre classi granulometriche distinte (>500µm, 250÷500 µm e <250 µm). la classe granulometrica utilizzata per proseguire la procedura è quella centrale. la classe granulometricamente più fine viene scartata, mentre la più grossolana viene conservata come scorta fino alla fine della procedura. le prime fasi ad essere allontanate sono costituite dai carbonati e dai minerali magnetici. i carbonati vengono lisciviati ponendo il campione in una soluzione 1:3 di 10%hcl e hno3 a 90°c per circa 12 ore. questa lisciviazione allontana completamente i carbonati e parte dei minerali magnetici. si procede poi con l’eliminazione dei feldspati e delle miche, utilizzando una particolare procedura che prende il nome di “froth floatation” (letteralmente “galleggiamento della schiuma”). affinché questo metodo dia buoni risultati, il campione deve essere precedentemente immerso per 1 ora in una soluzione di acido fluoridrico all’1%. l’impiego dell’acido fluoridrico cambia il chimismo della superficie dei granuli di feldspato / mica e del quarzo, rendendo i primi idrofobi e il secondo idrofilo. dopo un’ora l’hf viene eliminato e il campione viene immerso in una soluzione di 10 l di acqua a cui si aggiungono 1 ml di acido acetico e 1 g di laurilammina per ogni litro di acqua, alcune gocce di olio di pino o di eucalipto. l’acido acetico mantiene il ph della soluzione intorno a 5 per agevolare la dissoluzione dei feldspati ad opera della laurilammina. l’olio di pino o di eucalipto servono per mantenere unite le bolle di co2 nella soluzione carbonatica che tenderanno a rimanere in alto (come la schiuma della birra). i feldspati e le miche resi idrofobi 128 dall’hf si vanno a concentrare nella schiuma e quindi sono facilmente rimovibili. la procedura viene ripetuta più volte fino ad eliminare tutto il materiale idrofobo. quello che rimane è costituito solamente da quarzo e minerali pesanti. dopo aver asciugato il campione si procede all’eliminazione della restante parte dei minerali magnetici facendo passare il campione precedentemente lisciviato in un separatore magnetico. esso è costituito da un magnete che genera un campo magnetico di 1.2 ma utile ad estrarre i minerali magnetici sopravvissuti alla lisciviazione. al fine di eliminare gli allumino-silicati rimasti si pongono 40 g di campione in 400 ml di acido orto-fosforico all’85% a 240°c per circa 1 ora. gli allumino-silicati si legano fra loro formando una gelatina che deve essere dissolta e rimossa inserendo nel beaker dell’idrossido di sodio. si ritiene che tutti questi passaggi portino alla perdita di circa il 10% del quarzo presente nel campione iniziale, soprattutto se la granulometria dei cristalli è inferiore a 250 µm; per questo motivo il campione iniziale deve essere particolarmente ricco in quarzo. silicati ancora presenti nel campione dopo il trattamento con l’acido fosforico vengono dissolti immergendo il campione in hf diluito al 2% per 72 ore in una vasca ultrasonica. la maggior parte dei minerali silicatici si dissolve più velocemente del quarzo in hf diluito, quindi possono essere corrosi e facilmente asportati lasciando un campione residuo ricco in quarzo. la lisciviazione con hf ha il grande vantaggio di dissolvere anche la parte più esterna dei granuli di quarzo ed eventuali fratture dove si concentrano le contaminazioni di 10be meteorico. il processo viene ripetuto almeno tre volte, rinnovando ogni volta la soluzione a base di hf. alcuni minerali non vengono dissolti, come i minerali accessori (zircone, rutilo, ilmenite) che comunque non causano problemi per la successiva estrazione dell’al e be, il granato e la muscovite che è sopravvissuta alla froth floatation. la purezza del separato così ottenuto viene quantificata attraverso la misurazione della concentrazione dell’al nel campione. essa deve essere più bassa possibile, preferibilmente compresa fra 10÷100 ppm. una concentrazione più alta può essere sintomo della presenza di inquinanti (0,5% di feldspato corrisponde a circa 1000 ppm di al). una volta purificato il quarzo si procedere alla separazione dell’al e del be che vengono poi analizzati con l’ams usando la procedura della diluzione isotopica. questo metodo consiste nell’aggiungere al campione una quantità nota (spike) di un isotopo dello stesso elemento (9be e 27al); lo spettrometro misura i rapporti 9be/10be e 27al/26al da cui si può facilmente risalire alle quantità di 26al e 10be presenti nel campione. la tecnica della diluzione isotopica ha svariati vantaggi, sia analitici, poiché le misurazioni di rapporti sono in genere più precise ed accurate rispetto a misurazioni di concentrazioni assolute, sia metodologici, dal momento che, una volta che campione e spike sono in equilibrio nella soluzione, un’eventuale perdita parziale del campione non ha ripercussioni sull’analisi. una volta aggiunto il 9be e, se la concentrazione di al nel campione è <1000 ppm, l’27al, si procede con la “digestione” del campione in hf. il quarzo viene lasciato in hf concentrato a circa 100°c per il tempo necessario alla sua completa dissoluzione (1-5 giorni). la diluzione isotopica richiede la conoscenza della quantità di spike aggiunta con la massima precisione e accuratezza possibile. ciò si ottiene prelevando una piccola quantità (di solito circa 5 a. ciampalini et al. fig. 1 schema illustrante la prima parte della procedura di preparazione del campione (purificazione del quarzo). diagram showing the quartz cleaning procedure. 129 ml) dalla soluzione di hf contenente il quarzo dissolto. la soluzione prelevata viene trattata con h2so4 e hno3 e analizzata con l’icp-ms che fornisce la concentrazione nella soluzione dello spike. la soluzione di hf rimasta servirà per l’estrazione del be e dell’al. essa viene fatta evaporare completamente per eliminare i fluoruri tossici; sul fondo del beaker rimane una patina costituita da fe, ti, al, be, etc. che deve essere di nuovo disciolta per eliminare le impurità utilizzando la tecnica dello scambio ionico. la dissoluzione della patina viene eseguita aggiungendo 2 ml di 6n hcl. l’aggiunta avviene sulla piastra a 120°c perché la soluzione deve evaporare di nuovo. l’operazione viene ripetuta tre volte per consentire la perfetta dissoluzione della patina. alla fine della terza volta la soluzione non viene fatta evaporare ma viene posta in un tubo da centrifuga con altri 2 ml di 6n hcl. il tubo viene centrifugato per 10 minuti a 3500 rpm. lo scambio ionico avviene in due parti: lo scambio anionico e lo scambio cationico. la prima parte prevede che la colonna utilizzata per la separazione venga in parte riempita con una resina anionica (ag1 x8 200-400#) condizionata con 1,2m hcl e 6n hcl. una volta che gli acidi sono stati filtrati completamente attraverso la resina si versa il campione nella colonna. la parte di campione filtrata viene raccolta poiché contiene l’al e il be, mentre il fe e il ti sono stati catturati dalla resina. non tutto il ti viene catturato in questa parte della procedura, per cui il campione viene fatto evaporare fino a far rimanere soltanto una patina che viene trasformata in solfato aggiungendo al campione essiccato acqua pura con tracce di 0,5m h2so4 e fatta evaporare di nuovo. l’operazione viene ripetuta per tre volte consecutive. l’ultima volta l’evaporazione non viene effettuata. a questo punto il campione è pronto per lo scambio cationico per eliminare il ti rimasto e per separare il be dall’al. la procedura è simile a quella effettuata per lo scambio anionico ma utilizzando una resina cationica (ag 50w-x8 200-400#) che viene cariburial dating of late-cenozoic deposits ... fig. 2 schema illustrante la seconda parte della procedura di preparazione del campione (estrazione di al e be). diagram showing the extraction procedure of al and be. 130 cata nella colonna. la resina viene condizionata con 4m hcl, 1,2m hcl e 0,2m h2so4 prima di inserire il campione nella colonna. in questo caso l’al e il be vengono trattenuti dalla resina, mentre ciò che esce dalla colonna è acido contenente il ti. il be viene eluito dalla resina utilizzando 1,2n hcl e l’al con 4m hcl. la soluzione contenente be viene fatta evaporare fino a far rimanere una patina che verrà di nuovo disciolta in 2ml di 1%hno3. la soluzione viene portata a ph 4 usando 10%-20% nh4oh per precipitare l’eventuale ti che, in tal modo, viene eliminato. il ph viene successivamente aumentato fino ad 8 per permettere la precipitazione del be. la soluzione viene centrifugata in modo che il be precipitato si concentri alla base della provetta in modo da poter eliminare la parte liquida. il be viene essiccato in forno a 70°c. la stessa procedura viene seguita per far precipitare l’al. al e be vengono trasferiti in piccoli contenitori per essere posti nella fornace a 800°c per la completa deidratazione. a questo punto il campione è pronto per essere inserito nei catodi. il be viene mescolato con del nb, mentre l’al viene mescolato con ag per esaltare il segnale nell’ams. le miscele ottenute vengono inserite in appositi catodi e inviate all’ams per la misurazione dei rapporti isotopici. 5. interpretazione del dato il tasso di produzione del 10be e 26al nel quarzo esposto alla superficie terrestre è dovuto principalmente all’azione dei neutroni, mentre la produzione dei muoni è subordinata di molte grandezze. al contrario, in profondità, la componente dovuta ai muoni diviene dominante. la produzione dovuta ai neutroni è funzione della profondità ed è facilmente calcolabile attraverso la seguente equazione (lal, 1991; brown et al., 1992): (1) dove pn è il tasso di produzione dell’isotopo cosmogenico dovuto all’interazione con i neutroni (n), z è la profondità sotto la superficie e l0 prende il nome di lunghezza di attenuazione nucleonica ed è uguale a 160/ρ cm (reedy et al., 1994), dove ρ è la densità del materiale attraversato dai raggi cosmici (in g/cm3) e 160 (g/cm2) è la lunghezza di attenuazione per i neutroni veloci nel quarzo. la produzione dovuta ai muoni è anch’essa dipendente dalla profondità, ma non è facilmente modellizzabile con una equazione semplice. essa è rappresentabile con la somma di tre termini esponenziali (granger & smith, 2000; granger & muzikar, 2001): (2) dove p1 e p2 sono costanti legate alla produzione dei muoni lenti (0,096 e 0,021 per il be e 0,723 e 0,156 per l’al), p3 è una costante legata alla produzione da parte dei muoni veloci (0,026 per il be e 0,192 per l’al) e l1, l2 e l3 rappresentano le lunghezze di attenuazione nucleoniche relative ai muoni (738/ρ cm, 2688/ρ cm, 4360/ρ cm). la produzione dovuta ai muoni, in alcuni casi specifici e in particolare quando si calcolano età di esposizione, può essere trascurabile. in situazioni in cui la superficie è caratterizzata da tassi di erosione compresi fra 1m/ma e 10m/ma o dove i clasti non sono stati sepolti sufficientemente, ignorare la produzione dovuta ai muoni può significare incorrere in un errore nella valutazione del calcolo dei tassi di erosione o dell’età del seppellimento (granger & muzikar, 2001). 5.1 datazione di una superficie esposta e calcolo del tasso di erosione. la datazione dell’esposizione di una superficie è una delle applicazioni più comuni del metodo di datazione con i nct, poiché la concentrazione di nuclidi cosmogenici nelle rocce esposte è dipendente dal tempo durante il quale la superficie è rimasta esposta ai raggi cosmici. i risultati migliori sono stati ottenuti datando superfici che vengono esposte da eventi discreti come per esempio eruzioni vulcaniche, frane, superfici di faglia e superfici di esarazione di ghiacciai. si hanno condizioni ideali quando la superficie considerata ha subito una storia poco articolata (nessuna erosione o seppellimento dalla prima esposizione). in questo caso la concentrazione alla superficie dei radionuclidi, n(0), calcolata in funzione del tempo è la seguente (lal, 1991): (3) mentre per i nuclidi stabili è data da: (4) dove p(0) è il tasso di produzione alla superficie, λ è la costante di decadimento e t è il tempo di esposizione (fig. 3). il limite temporale superiore del metodo di datazione dipende sostanzialmente dal radionuclide utilizzato ed è determinato dalla costante di decadimento del radionuclide stesso (circa 4-5 volte il tempo di dimezzamento). la lunghezza di attenuazione considerata per il calcolo del tasso di produzione dei nct è piuttosto piccola. nelle rocce terrestri e lunari è compresa tipicamente fra 121 fino a valori poco maggiori di 170 gcm-2 (gosse & phillips, 2001). le equazioni (3) e (4) possono essere utilizzate solo quando la superficie esposta non ha subito erosione. le superfici che vengono erose risultano impoverite in nct, quindi la concentrazione misurata risulta più bassa di quella che si sarebbe potuta misurare in caso di non erosione. di conseguenza, se si misurasse un’età di esposizione, si tratterebbe di una età più giovane di quella reale. se la superficie è in erosione, la concentrazione degli isotopi cosmogenici può essere utilizzata per calcolare il tasso di erosione attraverso la seguente equazione: (5) dove ninh è la concentrazione ereditata da un eventuale periodo di esposizione precedente a quello che si va a considerare ed ε è il tasso di erosione. questa equazioa. ciampalini et al. ne assume che i nct siano solo prodotti dai neutroni, un’assunzione valida per tassi di erosione maggiori di 10m/ma o minori di 1m/ma (granger & muzikar, 2001). nel caso di tassi di erosione compresi fra questi due valori è necessario utilizzare una equazione più complessa che tenga conto anche della componente muonica nel tasso di produzione. l’equazione (5) ha due incognite, il tempo di esposizione t e il tasso di erosione ε e quindi, come tale, non può essere risolta a meno che una delle due incognite sia in altro modo conosciuta. per esempio, se si assume ε = zero, l’equazione (5) si riduce all’equazione (3) e il tempo di esposizione può essere calcolato. nel caso in cui il tasso di erosione sia diverso da zero, l’equazione (5) può essere risolta solo nel caso in cui l’erosione sia in condizioni di stato stazionario, cioè rimanga constante nel tempo e nello spazio (lal, 1991). in questo caso, infatti, il tasso di erosione può essere rappresentato come la velocità con cui una particella di roccia si avvicina alla superficie; se la velocità è constante (stato stazionario), la concentrazione di un isotopo cosmogenico, per esempio il 10be, fornisce il tasso di erosione. questo metodo da risultati migliori per tassi di erosione inferiori ai ~5 m/ma (lal, 1991). alti tassi di erosione possono essere calcolati utilizzando due isotopi, per esempio 26al e 10be; in questo caso si otterrà un sistema di due equazioni a due incognite (equazione 5) e quindi risolvibile. la concentrazione di due nct permette di calcolare il tasso di erosione, il tempo minimo di esposizione di una superficie e il tempo di seppellimento di superfici o sedimenti. nel quarzo l’26al viene prodotto ad una velocità circa sei volte superiore rispetto al 10be, ma decade ad una velocità doppia. il rapporto 26al/10be al momento in cui un campione raggiunge la superficie ha un valore pari a 6,9 (utilizzando i tassi di produzione della tab.1). 131burial dating of late-cenozoic deposits ... fig. 3 andamento della concentrazione dei radionuclide 10be, 26al, 21ne e del rapporto 26al/10be con il passare del tempo. la situazione si riferisce a misurazioni effettuate nel quarzo esposto su una superficie orizzontale, non schermata e non sottoposta ad erosione. le curve sono state ottenute utilizzando le equazioni (3) e (4) ed il tasso di produzione ad alte latitudini e sul livello del mare. variation of the concentrations of the radionuclides 10be, 26al, and the stable nuclide 21ne and of the ratio 26al/10be with time in quartz exposed at the surface of a flat, unshielded, non-eroding outcrop.the values are calculated using equation (3) and (4) using sea level, high latitude production rates. fig. 4 in questo grafico viene messa in relazione la concentrazione del 10be con il rapporto 26al/10be. i campioni prelevati da superfici continuamente esposte cadono sulla curva che unisce i cerchietti vuoti. i campioni prelevati da superfici sottoposte a erosione in condizioni di stato stazionario cadono, invece, sulla curva inferiore che unisce i cerchietti neri. le curve intermedie che uniscono quelle appena descritte mostrano l’andamento dei campioni per un determinato tasso di erosione. l’area compresa fra le due curve principali prende il nome di “isola dell’erosione allo stato stazionario” (lal, 1991). se i campioni hanno una storia evolutiva dal punto di vista dell’esposizione semplice e si assume che il tasso di erosione sia rimasto costante nel tempo allora essi cadranno all’interno dell’isola. i campioni che cadono al di sotto dell’isola hanno avuto una storia più complessa che può aver compreso periodi di seppellimento o erosione non allo stato stazionario (fabel, 2008). plot of 10be concentration vs. 26al/10be (also referred to as "banana-plot"). continuously exposed samples fall on the curve connecting the open circles. steadily eroding samples lie on the lower curve connecting the solid dots. the finest curves show the trajectory of samples within the 10be concentration vs. 26al/10be space for the given steady-state erosion rates. the area bounded by the continuous exposure and steady-state erosion curves is known as the "steady-state erosion island" (lal, 1991). given a simple exposure history and assuming production rate ratios have remained the same through time, all samples collected on the surface of the earth must lie within the steady-state erosion island. samples that lie below the steady-state erosion island have experienced a complex history, which may include burial, or non-steady state erosion in the sample's recent history (fabel, 2008). tab.1 caratteristiche dei principali isotopi cosmogenici trattati in questo lavoro. i tassi di produzione sono stati determinati e calibrati in località poste ad alte latitudini (>60°), sul livello del mare e su campioni già datati con altre metodologie (lal, 1991; stone et al ., 1998; dunai, 2000; 2001; niedermann, 2000; stone, 2000). characteristics of the major in-situ produced cosmogenic nuclides in terrestrial materials cited in this work. production rates have been calculated and calibrated at high latitudes (>60°), at sea level and in samples already dated with other methods lal, 1991; stone et al., 1998; dunai, 2000; 2001; niedermann, 2000; stone, 2000). aumentando il tempo di esposizione il rapporto 26al/10be tenderà a decrescere a causa della maggiore velocità di decadimento dell’26al, fino al raggiungimento dell’equilibrio secolare (fig. 4). in caso di superfici soggette ad erosione, l’equilibrio secolare viene raggiunto per valori di 26al/10be più alti. 5.2 calcolo dell’età di seppellimento il calcolo dell’età di seppellimento richiede, come per l’età di esposizione, il rispetto di alcuni vincoli. il primo prevede che il sedimento campionato sia stato esposto per un periodo di tempo sufficientemente lungo da acquisire una quantità misurabile di nuclidi cosmogenici prima del seppellimento. successivamente il sedimento eroso dal versante deve essere sepolto rapidamente in modo che sia schermato dai raggi cosmici e la produzione di nuovi nuclidi cosmogenici cessi definitivamente. l’età di seppellimento può essere calcolata solo misurando la concentrazione di due nuclidi, per esempio 26al e 10be. dal momento del seppellimento il rapporto 26al/10be inizia a decrescere seguendo un andamento ben conosciuto attraverso il quale è possibile risalire all’età di seppellimento che spesso corrisponde all’età di deposizione. questo metodo è ottimo, ad esempio, per datare sedimenti che si sono deposti in grotte, in sistemi deltizi di fiumi con aste fluviali piuttosto brevi o paleosuoli sepolti. utilizzando l’26al e il 10be l’equazione di granger & muzikar (2001) fornisce il tempo di seppellimento: (6) (7) dove tburial è l’età di seppellimento e (n26)i e (n10)i rappresentano rispettivamente il numero iniziale di atomi dell’26al e 10be. poiché l’26al decade più velocemente del 10be il tasso n26/n10 decresce in maniera esponenziale rispetto al tempo: (8) le incognite in questo caso sono 3: tburial, (n26)i e (n10)i. risolvendo contemporaneamente le equazioni (6), (7) e (8) e utilizzando il grafico di figura 5 è possibile ricavare l’età del seppellimento e il tasso di erosione che caratterizzava i versanti subito prima del seppellimento (granger et al., 1997; granger et al., 2001). il calcolo dell’età di seppellimento è utilizzabile per datare depositi che hanno un’età compresa fra 100.000 anni e 5 milioni di anni. il limite dei 100.000 anni è dovuto essenzialmente all’errore sperimentale. ciò deriva dall’incertezza nella misurazione del tasso 26al/10be, stimata nell’ordine del 5% che si traduce in una incertezza nel calcolo dell’età di circa 96.000 anni (granger & muzikar, 2001). il limite dei 5 milioni di anni è dovuto al tempo che i nuclidi impiegano a raggiungere il proprio equilibrio secolare. maggiore è il tempo di seppellimento, maggiori saranno le difficoltà nel misurare le concentrazioni di 26al e 10be nel sedimento stesso perché le concentrazioni diminuiscono. l’assenza di nuclidi cosmogenici nel deposito analizzato può avere diversi significati: (1) il tempo di seppellimento è maggiore di 5 milioni di anni per cui gli isotopi instabili sono completamente decaduti o (2) il periodo di esposizione ai raggi cosmici pre-seppellimento è stato talmente breve da non rendere possibile la formazione di nuclidi cosmogenici. e’ impossibile determinare quale delle due opzioni sia esatta senza disporre di ulteriori informazioni. nel caso in cui il tempo di seppellimento sia maggiore di 5 milioni di anni è teoricamente possibile utilizzare al posto dell’26al il 21ne, un isotopo cosmogenico stabile la cui concentrazione rimane costante una volta che il sedimento è stato sepolto. la possibilità di utilizzare il rapporto 10be/21ne per datare sedimenti pliocenici è ancora agli albori e non esistono ancora studi che abbiano applicato questa promettente metodologia. 132 a. ciampalini et al. fig. 5 grafico utilizzato per calcolare l’età di seppellimento di sedimento o di superfici in roccia utilizzando la concentrazione del 10be vs. il tasso 26al/10be. i campioni che non hanno subito seppellimento cadranno nella zona fra le curve indicate nel grafico con steady-state erosion e continuous exposure che corrisponde all’isola della figura 4. i campioni che hanno subito seppellimento e sono rimasti schermati dai raggi cosmici seguiranno le linee parallele alla linea che indica il normale decadimento radioattivo (radioactive decay time). il rapporto misurato 26al/10be determina l’età di seppellimento e può essere utilizzato per determinare anche il tasso di erosione attivo al momento della deposizione del sedimento (fabel, 2008). burial dating plot showing the 10be concentration and 26al/10be ratio in sediment or rock. quartz with no burial history should plot between the steady erosion and continuous exposure curves (fig.4). for quartz that is buried and completely shielded from cosmic rays, the 26al/10be decreases along a line parallel to the solid "radioactive decay time". the measured 26al/10be ratio in a sample determines the burial time, and can also be used to calculate the pre-burial erosion rate (fabel, 2008). 6. conclusione i nct sono uno strumento estremamente interessante ed utile per comprendere e studiare sia l’evoluzione e la storia della superficie terrestre sia per analizzare le velocità dei processi geologici e geomorfologici. questa metodologia sta velocemente integrando le tecniche di datazione classiche, soprattutto in campo geomorfologico e sta iniziando a dare un importante contributo anche in campo stratigrafico. i nct vengono utilizzati per datare forme e depositi (morene glaciali, terrazzi fluviali, depositi lacustri e marini costieri, depositi alluvionali, etc.) al fine di effettuare ricostruzioni paleoambientali e paleoclimatologiche. in geologia strutturale vengono impiegati per datare piani di faglie. in geomorfologia sono impiegati in maniera estensiva per studiare in modo quantitativo le variazioni del paesaggio nel tempo a diversa scala, dal singolo affioramento al bacino idrografico completo. lo studio della stratigrafia e dell’evoluzione del paesaggio durante il plio-pleistocene sono due aspetti che richiedono necessariamente l’utilizzo di metodi di datazione. purtroppo i metodi classici (es. biostratigrafia, palinologia) non sono spesso utilizzabili in quanto sono legati alla presenza di particolari organismi all’interno dei sedimenti e, comunque, non sono utilizzabili per datare le forme del paesaggio. altri metodi, come il 14c o gli osl, sono, invece, applicabili soltanto per datare sedimenti piuttosto giovani. in questo panorama l’utilizzo degli isotopi cosmogenici si inserisce con successo in quanto risulta applicabile in situazioni molto diverse fra loro. esso inoltre non si limita a restituire una datazione ma fornisce anche informazioni aggiuntive come, ad esempio, il tasso di erosione che era presente al momento della deposizione di un sedimento o che ha generato una forma. l’ampia utilizzazione del metodo è dovuta al fatto che gli isotopi cosmogenici sono legati ai minerali in cui si formano. in particolar modo l’26al e il 10be si formano nel quarzo il quale ha un’ampia diffusione nella crosta terrestre. uno dei vantaggi del metodo risiede anche nell’ampiezza dell’intervallo temporale in cui è applicabile. tale intervallo è legato al tempo di decadimento degli isotopi da analizzare e, quindi, permette di datare sedimenti o forme vecchie fino a circa 5 milioni anni fa. la validità del metodo è confermata anche dalla crescente presenza di questo tipo di analisi nelle pubblicazioni legate alle tematiche del quaternario. il calcolo dell’età di seppellimento, in particolare, risulterebbe di particolare interesse per ottenere delle datazioni assolute nelle successioni stratigrafiche della penisola italiana. in questo caso è necessario ricordare che il calcolo dell’età di seppellimento utilizzando gli isotopi 26al e 10be richiede il rispetto di condizioni ben definite che ne limitano l’uso a sedimenti di età compresa fra il messiniano e il pleistocene superiore a causa dell’incertezza nella misurazione. inoltre la possibilità di applicare questa metodologia è legata anche a fattori fisici e geologici come la necessaria presenza di quarzo nel sedimento, la presenza di depositi che abbiano acquisito un set di nuclidi cosmogenici prima della loro erosione e un seppellimento veloce dopo un breve trasporto. per questo i depositi deltizi legati ad un reticolo idrografico poco sviluppato o i depositi di grotta rappresentano delle condizioni ideali per datare i sedimenti utilizzando gli isotopi cosmogenici. bibliografia ackert r.p., barclay d.j., borns h.w., calkin p.e., kurz m.d., steig e.j., fastook j.l. (1999) measurement of ice sheet elevations in interior west antarctica. science 286, 276-280. alvarez-marron j., hetzel r., niedermann s., menéndez r. & marquinez j. (2008) origin, structure and exposure history of a wave-cut platform more than 1 ma in age at the coast of northern spain: a multiple cosmogenic nuclide approach. geomorphology 93, 3-4. anthony e.y. & poths j. (1992) 3he surface exposure dating and its implications for magma evolution in the potrillo volcanic field, rio grande rift, new mexico, usa. geochimica et cosmochimica acta 56, 4105–4108. ayarbe j.p., phillips f.m., harrison j.b.j., elmore d. & sharma p., (1998) application of cosmogenic nuclides to fault-scarp chronology: preliminary results from the socorro canyon fault . in: harrison, j.b.j. (ed.), soil, water, and earthquakes around socorro, new mexico: guidebook for the rocky mountain cell of the friends of the pleistocene 1998 field conference, 10-13 september 1998, new mexico tech, socorro, 12 pp. balco g. & rovey c.w. (2008) an isochron method for cosmogenic-nuclide dating of buried soils and sediments. american journal of science, 308, 1083-1114. balco g. & schaefer j.m. (2006) cosmogenic-nuclide and varve chronologies for the deglaciation of southern new england. quaternary geochronology 1, 15-28. ballantyne c., stone j.o.h. & fifield l.k. (1998) cosmogenic cl-36 dating of postglacial landsliding at the storr, isle of skye, scotland. the holocene 8, 347–351. barnard p.l., owen l.a., sharma m.c. & finkel r.c. (2001) natural and human-induced landsliding in the garhwal himalaya of northern india . geomorphology 40, 21–35. bierman p. & gillespie a. (1994) using in situ produced cosmogenic isotopes to estimate rates of landscapes evolution: a review from the geomorphic perspective. jour. geophys. res., 99, 13855–13896. bowen d.q., phillips f.m., mccabe a.m., knutz p.c. & sykes g.a. (2002) new data for the last glacial maximum in great britain and ireland. quaternary science reviews 21, 89–101. braucher r., bourlès d.l., brown e.t., colin f., muller j.p., braun j.j., delaune m., edou minko a., lescouet c., raisbeck g.m. & yiou f. (2000) application of in situ produced cosmogenic 10be and 26al to the study of lateritic soil development in tropical forest: theory and examples from cameroon and gabon. chemical geology 170, 95–111. brook e.j., brown e.t., kurz m.d., ackert r.p., raisbeck g.m. & yiou f. (1995) constraints on age, erosion and uplift of neogene glacial deposits in the transantarctic mountains determined from in situ cosmogenic 10be and 26al. geology 23, 1063–1066. brown e.t., brook e.j., raisbeck g.m., yiou f. & kurz m.d., (1992) effective attenuation length of cosmic rays producing 10be and 26al in quartz: implications for exposure age dating. geophysical research letters 19(4), 369-372. brown e.t., edmond j.m., raisbeck g.m., yiou f., kurz 133burial dating of late-cenozoic deposits ... m.d. & brook e.j. (1991) examination of surface exposure ages of antarctic moraines using in situ produced 10be and 26al. geochimica et cosmochimica acta 55, 2269–2283. brown e.t., stallard r.f., larsen m.c., bourlès d.l. & raisbeck g.m. (1998) determination of predevelopment denudation rates of an agricultural watershed (cayaguas river, puerto rico) using in-situproduced be-10 in river borne quartz. earth and planetary science letters 160, 723–728. cerling, t.e. (1990) dating geomorphic surfaces using cosmogenic 3he. quaternary research 33, 148–56. ciampalini a., fabel d., persano c. & firpo m. (2009) burial dating and erosion rates from pleistocene deltaic deposits of vado ligure (sv) using in-situ produced cosmogenic nuclides. in: epitome, 3, 82. geoitalia 2009, 9-11 settembre 2009, rimini. cockburn h.a.p., seidl m.a. & summerfield m.a. (1999) quantifying denudation rates on inselbergs in the central namib desert using in situ-produced cosmogenic 10be and 26al. geology 27, 399–402. davis r.j. & schaeffer o.a. (1955) chlorine-36 in nature. annals new york academy of science 62, 105-122. dunai t.j. (2000) scaling factors for the production rates of in-situ produced cosmogenic nuclides: a critical reevaluation. earth and planetary science letters, 176(1), 159-171. dunai t.j. (2001) influence of secular variation of the geomagnetic field on production rates of in situ produced cosmogenic nuclides . earth and planetary science letters, 193(1-2), 197-212. dunne j. elmore d. & muzikar, p. (1999) scaling factors for the rates of production of cosmogenic nuclides for geometric shielding and attenuation at depth on sloped surfaces. geomorphology 27(1-2), 3-11. fabel d. (2008) a brief introduction to in-situ produced terrestrial cosmogenic nuclide dating methods. http://web2.ges.gla.ac.uk/~dfabel/cn_ explain.html fabel d., fink d., fredin o., harbor j., land m. & stroeven a.p. (2006) exposure age from relict lateral moraines overbidden by the fennoscandian ice sheet. quaternary research 65, 136-146. gosse j., dort w., sorenson c., steeples d., grimes j. & hecht g. (1997) insights on the depositional age and rate of denudation of the pre-illinioan till in kansas from terrestrial cosmogenic nuclides. geological society of america abstracts with programs, north-central section 29 (4), a17. gosse j.c., evenson e.b., klein j., lawn b., middleton r. (1995) a precise cosmogenic 10be measurements in western north america: support for a global younger dryas cooling event. geology 23, 877–880. gosse j.c., klein j., evenson j., lawn b., middleton r., (1995) b 10be dating of the duration and retreat of the last pinedale glacial sequence. science 268, 1329–1333. gosse j.c.& phillips f.m. (2001) terrestrial in situ cosmogenic nuclides: theory and application. quaternary science reviews 20, 1475–1560. gosse j.c., harrington c.d., whitney j.w. (1996) applications of in situ cosmogenic nuclides in the geologic site characterization of yucca mountain, nevada. material research society symposium proceedings, 412, 799–806. granger d.e., fabel d. & palmer a.n. (2001) pliocenepleistocene incision of the green river, kentucky, determined from radioactive decay of cosmogenic al-26 and be-10 in mammoth cave sediments. geological society of american bulletin 113, 825836. granger d.e., kirchner j.w. & finkel r., (1997) quaternary downcutting rate of the new river, virginia, measured from differential decay of cosmogenic 26al and 10be in cave-deposited alluvium. geology, 25(2), 107-110. granger d.e. & muzikar p.f. (2001) dating sediment burial with in situ-produced cosmogenic nuclides: theory, techniques, and limitations. earth and planetary science letters, 188, 269-281. granger d.e. & smith a.l. (2000) dating buried sediments using radioactive decay and muogenic production of 26al and 10be. nuclear instruments and methods in physics research b 172(1-4), 822826. grosse a.v. (1934) an unknown radioactivity . j.am.chem.soc., 56, 1922-1923. ivy-ochs s., schlüchter c., kubik p., dittrich-hannen b., beer, j. (1995) minimum 10be exposure ages of early pliocene for the table mountain plateau and the sirius group at mount fleming, dry valleys, antarctica. geology 23, 1007–1019. heimsath a.m., chappell j., dietrich w.e., nishiizumi k. & finkel r.c. (2000) soil production on a retreating escarpment in southeastern australia . geology 28, 787–790. heimsath a.m, chappell j., spooner n.a. & questiaux d.g. (2002) creeping soil. geology 30, 111–114. heimsath a.m. dietrich w.e., nishiizumi k. & finkel r.c. (1999) cosmogenic nuclides, topography, and the spatial variation of soil depth. geomorphology 27, 151–172. hess v.f. (1912) penetrating radiation in seven free balloon flights. phys. zeitschr., 13, 1084-1088. jackson l.e., phillips f.m., shimamura k., little e.c. (1997) cosmogenic 36cl dating of the foothills erratics train, alberta, canada. geology 25, 195–198. jackson j., ritz j.f., siame l., raisbeck g., yiou y., norris r., youngson j. & bennet e. (2002) fault growth and landscape development rates in otago, new zealand, using in situ cosmogenic 10be. earth and planetary science letters 195, 185–193. klein j., giegengack r., middleton r., sharma p., underwood j.r. & weeks r.a. (1986) revealing histories of exposure using in situ produced 26al and 10be in libyan desert glass. radiocarbon 28, 547–555. kober f., ivy-ochs s., schlunneger f., baur h., kubik p.w. & wieler r. (2007) denudation rates and topography-driven rainfall threshold in northern chile: multiple cosmogenic nuclides data and sediment yield budgets. geomorphology 83, 97120. kubik p.w., ivy-ochs s., schlüchter c., masarik j. & 134 a. ciampalini et al. frank m. (1998) 10be and 26al production rates deduced from an instantaneous event within the dendro-calibration curve, the landslide of the köfels otz valley austria. earth and planetary science letters 161, 231–241. lal d. (1991) cosmic-ray labeling of erosion surfaces: in situ nuclide production rates and erosion models. earth and planetary science letters 104, 424-439. lal d. & peters b. (1967) cosmic-ray produced radioactivity on the earth. handbook of physics 46(2), 551-612. leland j., reid m.r., burbank d.w., finkel r. & caffee m. (1998) incision and differential bedrock uplift along the indus river near nanga parbat, pakistan himalaya, from 10be and 26al exposure age dating of bedrock straths. earth and planetary science letters 154, 93–107. libby f., anderson e.c., arnold j.r. (1949) age determination by radiocarbon content: world-wide assay of natural radiocarbon. science 109, 227228. licciardi j.m., kurz m.d., clark p.u. & brook e.j. (1999) calibration of cosmogenic 3he production rates from holocene lava flows in oregon, usa, and effects of the earth’s magnetic field. earth and planetary science letters 172, 261–271. liu b.l., phillips f.m., pohl m.m. & sharma p. (1996) an alluvial surface chronology based on cosmogenic 36cl dating, ajo mountains (organ pip cactus national monument) southern arizona. quaternary research 45, 30–37 marti k. & craig h. (1987) cosmic-ray produced neon and helium in the summit lavas of maui. nature 325, 335–37. matsushi y., wakasa s., matsuzaki h. & matsukura y. (2006) long-term denudation rates of actively uplifting hillcrests in boso peninsula, japan, estimated from depth profiling of in-situ produced be-10 and al-26. geomorphology 82, 283-294. miller g.h., wolfe a.p., steig e.j, sauer p.e., kaplan m.r. & briner j.p. (2002) the goldilocks dilemma: big ice, little ice or ‘just right’ ice in the eastern canadian arctic. quaternary science reviews 21, 33–48. mitchell s.g., matmon a., bierman p.r., enzel y., caffee m. & rizzo d. (2001) displacement history of a limestone fault scarp, northern israel, from cosmogenic 36cl. journal of geophysical research 106, 4247–4264. molnar p., brown e.t., burchfiel c., qidpong d., xianyue f., jun l., raisbeck g.m., jianbang s., zhangming w., yiou f. & huichuan y. (1994) quaternary climate change and the formation of river terraces across growing anticlines on the north flank of the tien shan, china. the journal of geology 102, 583–602. moscariello a., schneider a.m., filippi m.l. (1998) late glacial and early holocene palaeoenvironmental changes in geneva bay (lake geneva, switzerland). palaeogeography, palaeoclimatology, palaeoecology, 140, 51-73. nichols k.k., bierman p.r., hooke r.l., clapp e.m. & caffee m. (2002) quantifying sediment transport on desert peidmonts using 10be and 26al . geomorphology 45, 105–125. niedermann s. (2000) the 21ne production rate in quartz revisited. earth and planetary science letters 183(3-4), 361-364. nishiizumi k., klein j., middleton r. & craig h. (1990) cosmogenic 10be, 26al and 3he in olivine from maui lavas. earth and planetary science letters 98, 263–266. nishiizumi k., khol c.p., arnold j.r., klein j., fink d. & middleton r. (1991a) cosmic ray produced 10be and 26al in antarctic rocks: exposure and erosion history. earth and planetary science letters, 104, 440-454. nishiizumi k., khol c.p., shoemaker e.m., arnold j.r., klein j., fink d. and middleton r. (1991b) in-situ 10be and 26al exposure age at meteor crater, arizona. geochimica et cosmochimica acta 55, 2699–2703. perg l.a., anderson r.s. & finkel r.c. (2001) use of a new 10be and 26al inventory method to date marine terraces, santa cruz, california usa. geology 29, 879–82. phillips, f.m. (2000) muogenic nuclides: a method for dating rapidly eroding landforms. geochimica et cosmochimica acta 66, s1, a599. phillips f.m., leavy b.d., jannick n.o., elmore d. & kubik p.w. (1986) the accumulation of cosmogenic chlorine-36 in rocks: a method for surface exposure dating. science 231, 41–43. phillips f.m., zreda m.g., benson l.v., plummer m.a., elmore d. & sharma p. (1996) chronology for fluctuations in late pleistocene sierra nevada glaciers and lakes. science 274, 749–751. phillips f.m., zreda m.g., gosse j.c., klein j., everson e.b., hall r.d., chadwick o.a., sharma p. (1997) cosmogenic 36cl and 10be ages of quaternary glacial and fluvial deposits of the wind river range, wyoming. geol. soc. am. bull., 109(11), 14531463. phillips f.m., zreda m.g., smith s.s., elmore d., kubik p.w., dorn r.i. & roddy d.j. (1991) age and geomorphic history of meteor crater, arizona, from cosmogenic 36cl and 14c in rock varnish. geochimica et cosmochimica acta 55 , 2695–2698. phillips f.m., zreda m.g., smith s.s., elmore d., kubik p.w., sharma, p. (1990) cosmogenic chlorine-36 chronology for glacial deposits at bloody canyon, eastern sierra nevada. science 248, 1529–1532. pratt b., burbank d.w., heimsath a. & ojha t. (2002) impulsive alluviation during early holocene strengthened monsoons, central nepal himalaya. geology 30, 911–914. reedy r.c., arnold j.r., lal d. (1983) cosmic-ray record in solar system matter. science 219 (4581), 127-134. reedy r.c., nishiizumi k., lal d., arnold j.r. englert p.a.j., klein j., middleton r., jull a.j.t. & donahue d.j. (1994) simulations of terrestrial insitu cosmogenic nuclide production. nuclear instruments & methods in physics research b 92, 297-300. regard v., bellier o., braucher r., gasse f., bourles d., mercier j., thomas j.c., abbassi m.r., shabanian e. & soleymani s. (2006) be-10 of alluvial 135burial dating of late-cenozoic deposits ... deposits from southeastern iran (the hormoz strait area). palaeogeography, palaeoclimatology, palaeoecology 242, 36-53. repka j.l., anderson r.s. and finkel r.c. (1997) cosmogenic dating of fluvial terraces, fremont river, utah. earth and planetary science letters 152, 59–73. riebe c.s., kirchner j.w., granger d.e. & finkel r.c. (2000) erosional equilibrium and disequilibrium in the sierra nevada, inferred from cosmogenic 26al and 10be in al luvial sediment . geology 28 , 803–806. ritz j.f., brown e.t., bourlès d.l., philip h., schlupp a., raisbeck g.m., yiou f. & enkhtuvshin b. (1995) slip rates along active faults estimated with cosmic ray exposure dates: applications to the bogd faults, gobialtai, mongolia. geology 23, 1019–1022. schaller m., von blanckenburg f., hovius n. & kubik p.w. (2002) palaeo-erosion rate record in a 1.6 ma terrace sequence of the meuse river . geochimica et cosmochimica acta 66, s1, 673. schaller m., von blanckenburg f., hovius n. & kubik p.w. (2001) large-scale erosion rates from in situ-produced cosmogenic nuclides in european river sediments. earth and planetary science letters 188, 441–458. schroeder p.a., melear n.d., bierman p., kashgarian m. & caffee m. (2001) apparent gibbsite growth ages for regolith in the georgia piedmont . geochimica et cosmochimica acta 65, 381–86 seidl m.a., finkel r.c., caffee m.w., hudson g.b. & dietrich w.e. (1997) cosmogenic isotope analyses applied to river longitudinal profile evolution: problems and interpretations. earth surface processes and landforms 22, 195–210. shepard m.k., arvidson r.e., caffee m., finkel, r. & harris l. (1995) cosmogenic exposure ages of basalt flows: lunar crater volcanic field, nevada. geology 23, 21–4. small e.e., anderson r.s. & hancock g.s. (1999) estimates of the rates of regolith production using 10be and 26al from an alpine hillslope. geomorphology 27, 131–150. stone j.o. (2000) air pressure and cosmogenic isotope production. journal of geophysical research, 105(b10), 23753-23759. stone j.o., evans j.m., fifield l.k., allan g.l. cresswell r.g. (1998) cosmogenic chlorine-36 production in calcite by muons. geoch. et cosmoch. acta 62(3), 433-454. stone j., lambeck k., fifield l.k., evans j.m. & cresswell r.g. (1996) a lateglacial age for the main rock platform, western scotland. geology 24, 707–10. summerfield m.a., stuart f.m., cockburn h.a.p., sugden d.e., denton g.h., dunai t. & marchant d.r. (1999) long-term rates of denudation in the dry valleys, transantarctic mountains, southern victoria land, antarctica based on in-situ produced cosmogenic 21ne. geomorphology, 27, 113–29. templeton d.h. (1953) nuclear reactions induced by high energy particles. annual review of nuclear science 2, 93-104. trull t.w., brown e.t., marty b., raisbeck g.m. & yiou f. (1995) cosmogenic 10be and 3he accumulation in pleistocene beach terraces in death valley, california, usa. implications for cosmic-ray exposure dating of young surfaces in hot climates. chemical geology 119, 191–207. yingkui l., fabel d., stroeven a.p., harbor j. (2008) unraveling complex exposure-burial histories of bedrock surfaces under ice sheets by integrating cosmogenic nuclide concentrations with climate proxy records. geomorphology 99, 139-149. wells s.g., mcfadden l.d., poths j. & olinger c.t. (1995) cosmogenic 3he surface exposure dating of stone pavements: implications for landscape evolution in deserts. geology 23, 613–616. wilson p., bentley m.j., schnabel c., clark r. & xu s. (2008) stone run (block stream) formation in the falkland islands over several cold stages, deduce from cosmogenic isotope (be-10 and al-26) surface exposure dating . journal of quaternary science 23, 461-473. zreda m., england j., phillips f., elmore d., sharma p. (1999) unblocking of the nares strait by greenland and ellesmere ice sheet retreat 10,000 years ago. nature 398, 139–142. zreda m. & noller j.s. (1998) ages of prehistoric earthquakes revealed by cosmogenic chlorine-36 in a bedrock fault scarp at hebgen lake. science 292, 1097-1099. 136 ms. ricevuto il 13 giugno 2009 testo definitivo ricevuto il 1° ottobre 2009 ms. received: june 13, 2009 final text received: october 1, 2009 a. ciampalini et al. amq29(1) 3 galli 35-44.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 29 (1), 2016, 35 44 the little-known earthquake of 1643 in sicily paolo galli 1,2 1 dipartimento della protezione civile, rome italy 2 cnr igag, rome, italy corresponding author: p. galli <paolo.galli@protezionecivile.it > abstract: with earthquakes being most common to eastern sicily (mw >7.0), the mountainous region northwest of mount etna (madonie-nebrodi range) is affected by sparse, low magnitude seismicity (mw≤ 5.0), with macroseismic intensities ≤ 7-8 mcs. among these, the 1643 event is currently rated with an intensity of 6-7 mcs degree, related to only one locality (troina, enna province). new information retrieved from a coeval manuscript discovered in the national library of spain in madrid, together with other unknown documents, allows now to provide a reliable damaging scenario for the mesoseismic area of the 1643 sequence. news concern five localities, accounting for an epicentral intensity of 8 mcs and a related mw 5.6, which is the strongest of the region. in some villages, the 1643 effects were even higher than in 1693, the catastrophic earthquake that razed to the ground dozen of towns in eastern sicily, with damage from malta to palermo. the e-w elongated damage area fully matches the normal-fault plane solution of the focal mechanisms of two recent earthquakes falling close to the 1643 epicenter, suggesting thus a similar trend for the seismogenic structure. the earthquake was also followed by an unreported activity of mount etna which was dormant since 1638. keywords: historical seismology, 1643 earthquake, nebrodi seismicity, etna eruptions 1. introduction the seismicity of sicily is mainly clustered in the easternmost side of the island. leaving aside the isolated 1968 belice sequence in western sicily (mw 6.3), or the offshore seismicity paralleling the entire northern tyrrenian coast, from ustica to the aeolian islands (e.g., events of 2002, mw 5.9; 1823, mw 6.5; 1978, mw 6.1), all the strongest historical earthquakes occurred between the hyblean plateau to the south, and the messina strait to the north (fig. 1). among these, there are the most catastrophic events ever happened in europe, as those in january 9 and 11, 1693 (mw ~6 and mw 7.3, respectively), with a possible ancestor in february 4, 1169 (mw ~6.5), and the december 28, 1908 earthquake and tsunamis (mw 7.3). furthermore, mw>6 events occurred in 1542 (lentini area: mw 6.4), 1818 (southern etna area: mw 6.2), and 1786 (patti area: mw 6.2), besides sever others spanning 5.5<mw<6.0, with epicenters mainly in the hyblean plateau and along its eastern coast. conversely, in the rest of sicily, and chiefly northwest to mount etna (i.e., e-w trending ranges of nebrodi-madonie mountains; fig. 1), the seismic catalogues report sparse epicenters of low magnitude earthquakes (mw≤ 5.5), which are seldom responsible for damage, as in the 1818 and 1819 events (io 7-8 mcs; madonie mountains) or in the 1967 earthquake (io 8 mcs; nebrodi mountains). according to the seismic compilations (e.g., mongitore, 1743; mercalli, 1883; baratta, 1901; postpischl, 1985; cpti, 2011: from now cpti11), in 1643 another event hit the town of troina (nebrodi mountains), with effects rated at the 6-7 mcs degree. here i present new detailed information on this earthquake extracted from different contemporary documents which have remained hidden in the archives during the past 350 years. the news contained in these manuscripts allow to define the damage extent in troina and in other neighboring villages, contemporary also to an unknown eruptive activity of the etna volcano. 2. the 1643 seismic sequence as aforementioned, this earthquake is reported by baratta (1901) to be occurred in troina on july 17 when, due to a violent shock, all the inhabitants left their houses, and part of the mother-church and the monastery of saint elias of ambola (ambula, ambolà, ebulo/i) collapsed. the only source of baratta (1901) is mongitore (1743) who, in turn, deduces the news from pirri (1647). basing on this information, barbano et al. (1996) assign 6-7 mcs to troina, as reported today in cpti11 (fig. 2). as serendipity is a usual phenomenon in historical seismology, while i was looking for information on other earthquakes, i have found unknown news of this event examining some journalistic avisos printed in madrid (in valladares de sotomayor, 1790). firstly, the one dated october 13, 1643 which reports a vague notice about the explosion of the etna, and of the resulting destruction caused in sicily. then, the following (october 20) indicating with much more detail what really happened since july 17 in the "ciudad y comarca de traina, la mas populosa del val de moac" (i.e., val demone. troina exceeded 5,500 inhabitants in the 17th century; maggiore-perni, 1892), as in cherame (cerami), nicosia and bronte (fig. 3). 36 galli p. fig. 1 distribution of the macroseismic epicenters of 4.9≤mw≤7.3 earthquakes listed in the cpti11 (n.b., the 1908 epicenter is an instrumental estimate proposed by michelini et al., 2004). note that the strongest events are all clustered in eastern sicily, between the hyblean plateau and the messina strait. in turn, madonie and nebrodi mountains have only scattered mw≤5.5 earthquakes. dashed rectangle, area of fig. 9. fig. 2 family tree of sources for the 1643 earthquake. rectange, printed studies; rounded rectangle, manuscripts; yellow indicates the unknown sources discussed in this paper. note that the only real source of cpti11 is pirri (1647). 37 the little-known earthquake of 1643 in sicily clearly, these avisos were based on a more detailed report that i have finally found in the biblioteca national de españa (madrid). this is a eight page-long manuscript included in a volume of papeles varios which contains the report of silvestro randelli on the earthquakes en la ciudad de trayna and on the effects caused there and in the surrounding region (fig. 4). randelli (sylvestro randeli in the manuscript) was the fiscal prosecutor of the tribunal of the great court, and was also a notary in troina, a title which implies that he was an expert of all the places, of the real estate and of their condition. his report was printed later in madrid by diego diaz (relacion de los terremotos....por el dotor silvestre randole), although with some differences with respect to the original manuscript (fig. 5; randelli, 1643b). according to randelli (1643a), the seismic sequence started in august 1642, with two strong shocks in the night of 21 (around 0:30 a.m., local time) and 22 (around 2:45 a.m.). these events scared all the inhabitants of troina that sought refuge in the countryside, where they observed several sulphur-smell fissures fig. 3 copy of the first page of the avisos printed in madrid with the first news on the 1643 earthquake in sicily (from valladares de sotomayor, 1790) fig. 4 first page of the report by silvestro randelli on the effects of the 1643 earthquakes in troina, cerami, bronte, nicosia and on the contemporary etna eruption (manuscript 11209 of the biblioteca nacional de españa). at the top of the page it can be read: relacion de los terremotos que han sucedido en la ciudad de trayna este año de 1643 y los efectos que an causado en las circumbecinas en la forma siguiente, embiada por el doctor sylvestro randeli procurador fiscal de la g[ran] c[orte] opening in the ground surface. damage to buildings was generally light, except in the mother-church, where a deep crack opened in the wall. earthquakes were felt again in june 21 of the next year, and then again in july 12 and 15, especially in bronte. the 1643 mainshock occurred at 1:20 a.m. of july 18 (the 5th hour of the night of friday 17; i.e., five hours after the sunset, accordingly to italian time), lasting for the time of an ave maria (around 10''), and then replying suddenly for a much longer time (i.e., a miserere, more than 1'). in troina, the people escaped from the houses without clothes, screaming and invoking god and all the saints. the earthquake damaged all the buildings, some more and other less, whereas five houses collapsed, causing two casualties and injuring several persons. also part of the nave of the mother-church fell down (it collapsed entirely on sunday, due to an aftershock), as the church of saint sylvester and the monastery of saint elias of ambulà (located far away from the town), as reported also in another manuscript composed by an 38 galli p. tonino da troina (1710), a friar born and lived in troina (see also pirri, 1647). in cerami the effects were much stronger, as the castle was destroyed, and the churches in the highest part of the village collapsed (likely the mother-church and saint sebastian). also 150 houses were destroyed, plus other 50 in the countryside, causing one casualty and 30 injured. a huge rocky mass, which randelli (1643a) describes big as the palermo cathedral (i.e., ~80,000 m3), detached from the sandstone cliff over which cerami is founded, destroying everything downhill, including trees and vineyards. the landslide left some houses in very unsafe equilibrium, i.e., some downthrown from their original position, other rotated. in bronte all buildings were damaged, three person died and three were injured under the collapse of their house. churches also were severely hit, with restorations made in the same year (e.g. in fig. 6). in nicosia the earthquake was less violent, causing only the partial collapse of the chapel of the blessed sacrament in the mother-church, together with the fall of several statues inside (see fig. 7 to see all the localities fig. 5 copy of the first page of the relacion of silvestro randelli (1643b; here silvestre randole) printed in madrid by diego diaz. the printed version slightly differs from the manuscript. 39 the little-known earthquake of 1643 in sicily that were struck by the earthquake in a 17th century map). randelli (1643a) highlights also that from july 18 to 28, the mainshock was accompanied by a noticeable activity of mount etna, that incessantly generated roars resembling heavy artillery shells. during the seismic sequence, etna erupted from a mouth which opened in front of the major one. huge ground deformation phenomena were also observed on the volcano slopes, as the progressive lowering of a hill with 3-miles of perimeter. a secondary mouth opened also in the territory of bronte, where it happened that all the streams feeding the numerous mills at the etna's foothill dried up. according to randelli (1643a), this "es señal de no haver cessado la causa de el temblor de la tierra" (i.e., this fact is a clear signal that the cause of the earthquakes are not yet ceased). it is worth noting that this activity of the volcano, that had remained silent since the long eruption in 1634-1638 (e.g. in guidoboni et al., 2014), is completely unknown to the historical/scientific literature. the aftershocks sequence was still ongoing in august, when at dawn of 12 a strong earthquake struck fig. 6 inscription over the architrave of san vito church in bronte, attesting the restoration made in 1643 by matteo and michele di palermo, under the priorate of antonio da bronte. although the earthquake is not explicitly recalled here (as elsewhere in any other epigraph in the region), it is likely that the restoration work concerned also the earthquake damage. again the region. curiously, at the end of the randelli's manuscript, the author notes several women with miscarriages, and animal freaks being born in the aftermath (e.g., a calf with four eyes, a chicken with four wings, four feet and two tails). 3. discussion 3.1. earthquake parameters on the basis of the description provided by randelli (1643a), it is likely that the most severe effects were felt in the village of cerami where, alongside the ruin of the castle and of some churches, 200 houses were destroyed or, at least, strongly damaged, whereas all were severely hit. here, the strong seismic shaking is also suggested by the huge rock fall that affected the upper part of the town, the signs of which can still be imaged today by observing its suggestive skyline (fig. 8). this allow to assign at least 8-9 mcs degree in cerami, something more than in troina (8 mcs) where fig. 7 clip from a map of funk and homann (ca. 1700; base-topography redraw from g. mercator, 1512-1594) with the localities hit by the january 1693 earthquakes (asterisks indicate loca terremotu destructa; i.e., places destroyed by the earthquake). in turn, yellow lines evidence the localities struck by the 1643 event: troina (traina in the map), bronte (bronti), cerami (cirami), nicosia, and the monastery of saint elias of ambulà (eubuli). aetna mons mongibello is, obviously, mount etna. 40 galli p. all the buildings were damaged too, and few collapsed (fig. 9). also in bronte all buildings were damaged, whereas some collapsed; however, here the information does not allow to give a certain site intensity degree, and thus i suggest 7-8 mcs. in nicosia, where randelli (1643a) indicates heavy damage only in the mother-church, intensity could be estimated around 6-7 mcs. at the end, there is another locality 8 km north of troina (figs. 7, 9), the disruption of which is maintained by randelli (1643a), antonino da troina (1710), and pirri (1647). this is the monastery of saint elias of ambolà (the ruins of which lay today in the municipality land of cesarò), that can be classified as "high damage" (hd; see tab.1). in the whole, casualties were at least 6, in addition to several dozens of injured, mostly in cerami. although few intensity datapoints can only provide a rough idea of the earthquake epicentral parameters, by using the algorithm boxer4 (gasperini et al., 2010) the epicentral intensity (io) is 8 mcs, the magnitude from io is mw 5.57, and the epicenter is at coordinate n37°.79 e14°.65 (see tab. 2), that is a point very close to troina where many ground fissures were observed by the inhabitants since the early foreshock in 1642. boxer4 allows also to estimate the indicative length of the seismogenic faults, which in this case is 7 km, striking roughly e-w (n93°). certainly, the earthquake affected much more localities of the region, and it was likely felt in all the villages along the tyrrhenian coast to the north, and in the catania coast to the east. however, considering the deep destructions caused by the 1693 earthquakes, it is possible that the few documents attesting the far-field effects of the 1643 have been lost. indeed, it is not by chance that the only reports that survived to this day are in madrid, and concern only the most damaged area. 3.2. relationships with the regional seismicity considering the regional historical seismicity (fig. 1), the 1643 can be considered the strongest event occurred in this area. in some villages, the 1643 effects were similar or even higher than in january 1693, the catastrophic earthquakes that razed to the ground dozen of towns in eastern sicily, with damage from malta to palermo. for instance, in troina, the houses and churches "fracassate e dirupate" (damaged and ruined; relationes, 1693) by the 1693 event were 297 (vs a total of ~1000 buildings), indicating a site intensity close to the one assigned for the 1643 mainshock (i.e., 8 mcs degree). on october 31, 1967 an event with mb 4.9 (margottini et al., 1993; ≈ mw 5.0) hit a conterminous sector of the nebrodi area, damaging also cerami, nicosia and, above all, old and crumbling buildings in several villages and countryside toward the tyrrhenian coast. although this event is rated with an io 8 mcs, it did not caused any casualties or injuries, whereas the informafig. 8 view looking east of the huge, massive sandstones toppling which affects the cerami slopes, likely recalling the 1643 rock fall. fig. 9 orange circles, 1643 intensity datapoints distribution (dimension proportional to site intensity 6-7 to 8-9 mcs; hd, high damage. see tab. 1 for analytics). yellow star, epicenter estimated with boxer4 algorithm. dashed ellipse suggests the mesoseismic area. red star is the instrumental epicenter of the 1967, mw 5.0 earthquake. black stars are the instrumental epicenters of the 2009 and 2013, mw 4.4 events (focal mechanism from ingv-rcmt website page: http://www.bo.ingv.it/rcmt/). 41 the little-known earthquake of 1643 in sicily tion deducible from the newspapers of the time accounts for a likely lower degree (7 mcs). in turn, two smaller events (mw 4.4) had their epicenters within the 1643 mesoseismic area in 2009, and 2013. both did not produced damage (io≤ 5-6; azzaro et al., 2014), and both were generated by crustal, e-w trending normal fault (see "beach balls" in fig. 9), likely dipping southward. from a kinematic point of view, these focal mechanisms fit the prevailing ~n-s extension characterizing the madonie and nebrodi mountains, as evidenced by the gps velocity analyses in palano et al. (2012) and by the geological indication collected by pavano et al. (2015) toward the conterminous western peloritani mountain. therefore, taking into account that the 1643 mesoseismic area is strongly elongated from bronte to the east toward nicosia to the west (yellow ellipse in fig. 9), it is likely that the 1643 seismogenic structure is part of this e-w trending normal fault system. 3.3. relationships between the seismic sequence and the etna eruption the volcanic triggering and interaction with the surrounding tectonics (e.g. in eggert and walter, 2009) is an endless issue studied by hundreds scholars since darwin (1840). in the etna region, the volcanic activity seems to be correlated to regional tectonic earthquakes (sharp et al., 1981; feuillet et al., 2006), as seismicity increases before the onset of flank and/or summit activity, being thus considered as a possible precursor to volcanic activity. in 1643, beyond the continuous etna roars resembling heavy artillery shells, and the huge ground deformations, the eruption took place from a mouth opened below the main crater and from another on the western flanks, toward bronte. what i notice here is that while randelli (1643a) reports the onset of the seismic sequence since august 1642 with the two ~mw 4.7 events in the nights of 21 and 22, followed by other strong foreshocks on june 21, 1643, and july 12 and 15 the eruption is instead recalled on july 18, that is immediately after the mainshock of the same night. therefore, it is likely that the foreshocks sequence and the mainshock itself predated the eruption which, subsequently, lasted until july 28, ending then prior to the aftershocks swarm that was still ongoing in mid august. 4. concluding remarks the manuscripts perused at the national library of spain (randelli, 1643a), together with another manuscript written by a friar of tronia (antonino da troina, 1710), in addition to other documents (pirri, 1647; avisos in: valladares de sotomayor, 1790), have allowed to provide robust parameter to the previously little-known july 18, 1643 earthquake. this was the mainshock (io 8 mcs, mw 5.6) of a sequence started in august 1642 (21 -22 august; io 6 mcs, mw 4.72), which was also accompanied by a noticeable etna activity. the news concern five localities roughly aligned in a e-w direction, the same trend of the normal faults that recently sourced a couple of mw 4.4 earthquakes. the event caused heavy damage and collapses in cerami, troina and bronte, where at least 6 persons died under the ruins and dozens were injured. it is worth remembering that alongside historical high magnitude earthquakes (mw>6.5) that occurred before the 14th-13th century (e.g., galli and peronace, 2014; 2015; galli et al., 2015; 2016), our seismic catalogues missed or listed as lesser events several moderate earthquakes also during the late middle age and the early modern period (castelli, 2003; castelli and camassi, 2005), especially in the former kingdom of the two sicilies (e.g. in: albini and rodriguez de la torre, 1993; locality latitude longitude intensity cerami 37.810 14.509 8-9 troina 37.783 14.599 8 bronte 37.786 14.834 7-8 nicosia 37.747 14.398 6-7 sant'elia di ambolà 37.847 14.612 hd tab. 1 mcs macroseismic intensities estimated for the 1643 earthquake (see fig. 9). catalogue date lat n long e mm/mw io np area pos85 1643 07 17 37.67 14.67 4.7 7.0 0 m. salici cpti11 1643 07 17 37.783 14.599 4.93 6.5 1 troina ussn 1642 08 21 37.79 14.65 4.72 6.0 1 troina ussn 1642 08 22 37.79 14.65 4.72 6.0 1 troina ussn 1643 07 18 37.79 14.65 5.57 8.0 4 troina tab. 2 epicentral parameters of the 1642-1643 earthquakes. comparison among the records in postpischl (1985; pos85), cpti11 and this paper (ussn). 42 galli p. cpti (1999) working group catalogo parametrico dei terremoti italiani, ingv, gndt, sgs, ssn, bologna, 1999, 92 pp. cpti (2011) the 2011 version of the parametric catalogue of italian earthquakes, rovida a., camassi r., gasperini p., stucchi m. (eds.). istituto nazionale di geofisica e vulcanologia, milano, bologna. doi: http://doi.org/10.6092/ingv.it-cpti11 darwin c. (1840) on the connection of certain volcanic phenomena in south america; and on the formation of mountain chains and volcanoes, as the effect of the same power by which continents are elevated. transactions of the geological society of london, 2, 601-632. eggert s., walter t.r. (2009) volcanic activity before and after large tectonic earthquakes: observations and statistical significance, tectonophysics, 471, 14-26. feuillet n., cocco m., musumeci c., nostro c. (2006) stress interaction between seismic and volcanic activity at mt. etna. geophysical journal international 164, 697-718. funk d., homann j. b. (ca. 1700) infelicis regni siciliae tabula in tres valles divisa demonae, notae et mazarae, norimberg. galli p., peronace e. (2014) new paleoseismic data from the irpinia fault. a different seismogenic perspective for southern apennines (italy), earthscience reviews, 136, 175-201. galli p., peronace e. (2015) low slip rates and multimillennial return times for mw 7 earthquake faults in southern calabria (italy), geophysical research letters, 13, 5258-5265. galli p., giaccio b., peronace e., messina p. (2015) holocene paleoearthquakes and early-late pleistocene slip-rate on the sulmona fault (central apeninnes, italy), bssa, 105(1), 1-13. galli p., giaccio b., messina p., peronace e. (2016) three magnitude 7 earthquakes on a single fault in central italy in 1400 years evidenced by new palaeoseismic results. terra nova, 28, 146-154. galli p., scionti v. (2006) two unknown m>6 historical earthquakes revealed by palaeoseismological and archival researches in eastern calabria (southern italy). seismotectonic implications, terra nova, 18, 44-49. gasperini p., vannucci g., tripone d., boschi e. (2010) the location and sizing of historical earthquakes using the attenuation of macroseismic intensity with distance, bull. seism. soc. am., 100, 2035-2066. guidoboni e., ciuccarelli c., mariotti d., comastri a., bianchi m.g. (2014) l'etna nella storia. catalogo delle eruzioni dall'antichità alla fine del xvii secolo, bononia university press, 1122 pp. maggiore-perni f. (1892) la popolazione di sicilia e di palermo dal x al xviii secolo, virzì, palermo. margottini c., ambraseys n.n., screpanti a., 1993. la magnitudo dei terremoti italiani del xx secolo. enea, roma, 57 pp. mercalli g. (1883) i vulcani e i fenomeni vulcanici in italia, in: negri g., stoppani a., mercalli g., geologia d'italia, parte terza, milano, francesco vallardi, 374 pp. castelli et al., 2008; galli and scionti, 2006; scionti et al., 2006). as the italian hazard maps are currently based on the historical seismic catalogue (cpti2, i.e., an updated version of cpti, 1999), these deficiencies imply a misleading computation of the seismic hazard, and thus of the associated risk. this is the case of the nebrodi area, where the previously unknown 1643 event is either the strongest one ever occurred in this region (mw 5.6) and the one which induced the highest intensities in many villages therein (up to 8-9 mcs). acknowledgments i am grateful to b. arona who kindly provided me the news reported in the manuscript of friar antonino da troina, together with the relationes concerning the effects of the 1693 earthquake in troina, and the information about silvestro randelli. v. scionti helped me in reading and translating the randelli's manuscript. two anonymous reviewers provided me useful advices. the views and conclusion contained in this paper are those of the author and should not be interpreted as necessarily representing the official policies, either expressed or implied, of the italian government. references albini p., rodriguez de la torre f. (1993) known and unknown earthquakes through some european periodicals of the eightenth century, terra nova, 5, 481-487. antonino da traina (1710) memorie della vetustissima e nobilissima città di troina. b. arona (ed.), traina, 2013. azzaro r., d'amico s., mostaccio a., scarfì l., tuvè t., manni m. (2014) terremoti con effetti macrosismici in sicilia orientale nel periodo gennaio 2009 dicembre 2013. quad. geof., 120, 55 pp. baratta m. (1901) i terremoti d'italia. saggio di storia, geografia e bibliografia sismica italiana con 136 sismocartogrammi. torino, 950 pp. barbano f., azzaro r., birritta p., castelli v., lo giudice e., moroni a. (1996) stato delle conoscenze sui terremoti siciliani dall'anno 1000 al 1880: schede sintetiche. gndt, rapporto interno, catania, 287 pp. macroseismic data points are available also at http://emidius.mi.ingv.it/dom/consultazione.html camassi r., castelli v. (2004) looking for new earthquake data in the 17th-18th c. european newssellers network, journal of earthquake engineering, 8, 335-359. castelli v. (2003) strong earthquakes included «by chance» in italian catalogues: single cases or a hint of more? annals of geophysics, 46, 12471263. castelli v., camassi r. (2005) the shadow-zone of major italian seismicity. notes on the perception of lesser damaging earthquakes by 17th-18th c. journalistic sources, journal of earthquake engineering, 9, 333-348. castelli v., galli p., camassi r., caracciolo c. (2008) the 1561 earthquake(s) in southern italy: new insights into a complex seismic sequence, journal of earthquake engineering, 12, 1054-1077. 43 the little-known earthquake of 1643 in sicily michelini a., lomax a.j., bono a., nardi a., palombo b., rossi a. (2004) relocation of instrumentally recorded, historical earthquakes in the italian region. european seismological commission, september 2004, potsdam. mongitore a. (1743) della sicilia ricercata nelle cose più memorabili, ii. palermo, stamperia di francesco valenza. palano m., ferranti l., monaco c., mattia m., aloisi m., bruno v., cannavò f., siligato g. (2012) gps velocity and strain fields in sicily and southern calabria, italy: updated geodetic constraints on tectonic block interaction in the central mediterranean. journal of geophysical research, 117: doi: 10.1029/2012jb009254. pirri r. (1647) siciliae sacrae, in qua sicularum abbatiarum...auctore abbate…don roccho pirro… panormi. ex typographia nicolai bua et michaelis portanova, 150 pp. postpischl d. (1985) catalogo dei terremoti italiani dall'anno 1000 al 1980. quaderni della ricerca scientifica, 114, 2b, bologna, 239 pp. randelli s. (1643a) relacion de los terremotos que han sucedido en la ciudad de trayna este año de 1643 y los efectos que an causado en las circumbecinas en la forma siguiente, embiada por el doctor sylvestro randeli procurador fiscal de la g.c. biblioteca nacional de españa, papeles varios, s.xvii, mss/11209, 110 pp. randelli s. (1643b) relacion de los terremotos que han sucedido en la ciudad de traina este año de 1643 y los efectos que han causado en las circunvecinas, en la forma siguiente. madrid, por diego díaz de la carrera, 1643. relationes (1693) relationes redacta ed esaminata per curia sp.juratorum huius ctas troyne et com. m.ti eccmi. juds camastre vicarij jurates catane sub die 23 febbraij 1693 tale sub prout infra. archive of the municipality of troina, corte giuratoria, 84, 1v-1r. scionti v., galli p., chiodo, g. (2006) the calabrian seismicity during the viceroyalty of naples: sources silence or silent sources? the case of the strong 1744 earthquake. boll. geof. teor. appl., 47, 2645. sharp a.d.l., lombardo g., davis p.m. (1981) correlation between eruptions of mount etna, sicily and regional earthquakes as seen in historical records from ad 1582. geophysical journal of the royal astronomical society, 65, 507-523. valladares de sotomayor a. (1790) semanario erudito que comprehende varias obras ineditas, criticas, morales, instructivas, politicas, historicas, satiricas, y jocosas de nuestro mejores autores antiguo y modernos. tomo xxxiii, antonio espinosa, madrid. ms. received: march 30, 2016 final text received: may 06, 2016 44 galli p. << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /none /binding /left /calgrayprofile (dot gain 20%) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /error /compatibilitylevel 1.4 /compressobjects /tags /compresspages true /convertimagestoindexed true /passthroughjpegimages true /createjobticket false /defaultrenderingintent /default /detectblends true /detectcurves 0.0000 /colorconversionstrategy /cmyk /dothumbnails false /embedallfonts true /embedopentype false /parseiccprofilesincomments true /embedjoboptions true /dscreportinglevel 0 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/hrv (za stvaranje adobe pdf dokumenata najpogodnijih za visokokvalitetni ispis prije tiskanja koristite ove postavke. stvoreni pdf dokumenti mogu se otvoriti acrobat i adobe reader 5.0 i kasnijim verzijama.) /hun 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can be opened with acrobat and adobe reader 5.0 and later.) >> /namespace [ (adobe) (common) (1.0) ] /othernamespaces [ << /asreaderspreads false /cropimagestoframes true /errorcontrol /warnandcontinue /flattenerignorespreadoverrides false /includeguidesgrids false /includenonprinting false /includeslug false /namespace [ (adobe) (indesign) (4.0) ] /omitplacedbitmaps false /omitplacedeps false /omitplacedpdf false /simulateoverprint /legacy >> << /addbleedmarks false /addcolorbars false /addcropmarks false /addpageinfo false /addregmarks false /convertcolors /converttocmyk /destinationprofilename () /destinationprofileselector /documentcmyk /downsample16bitimages true /flattenerpreset << /presetselector /mediumresolution >> /formelements false /generatestructure false /includebookmarks false /includehyperlinks false /includeinteractive false /includelayers false /includeprofiles false /multimediahandling /useobjectsettings /namespace [ (adobe) (creativesuite) (2.0) ] /pdfxoutputintentprofileselector /documentcmyk /preserveediting true /untaggedcmykhandling /leaveuntagged /untaggedrgbhandling /usedocumentprofile /usedocumentbleed false >> ] >> setdistillerparams << /hwresolution [2400 2400] /pagesize [612.000 792.000] >> setpagedevice amq83 baldanza et al proofcopy 3 available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 31 (1), 2018, 87 104 new integrated data from clay lacustrine deposits of the dunarobba area (umbria, central italy) angela baldanza 1, roberto bizzarri 1, lucio di matteo 1, marco lezzerini 2, luca mencaroni 1, stefano pagnotta 2, simona raneri 2, giuseppe vinti 1 1department of physics and geology, university of perugia, perugia, italy. 2department of earth sciences, university of pisa, pisa, italy. corresponding author: r. bizzarri <roberto.bizzarri@libero.it> abstract: this paper is aimed to illustrate and discuss new data from the clayey deposits collected in the dunarobba area (umbria, central italy), and to better understand some features of the “fosso bianco” unit lacustrine stage inside the south tiberino basin, during its latest (presumably early pleistocene) phases. data come from a newly cultivated quarry area (cava nuova), only partly considered in previous works; the new section extends well inside the deep lake depositional stage of fosso bianco unit, previously not directly described in outcrop in the dunarobba area, but only reported from well logs. selected samples from the cava nuova section were analyzed from sedimentological, geotechnical, chemical, mineralogical and biostratigraphical point of view. sedimentological and geotechnical analyses, including density measurements, particle-size analysis, atterberg limits and organic matter content, as well as xrf and xrpd analyses, resulted the most suitable techniques to identify the main features, at least for prevailing clayey deposits. facies analysis and sedimentological data lead to recognize a clear depositional transition from relatively deep to shallow lacustrine deposits, which was only rarely documented formerly through a single section. on the other hand, both geotechnical and mineralogical data indicate a compositional homogeneity for clay sediments, which does not correspond with facies lateral and vertical variability nor with palaeoenvironmental complexity. despite its preliminary nature, this integrated method looks very promising to characterize the paleodepositional context, and some hypotheses on sediment source were also evaluated. integrated data from cava nuova section, as well as minor well-logs in the immediate surroundings, were discussed and compared with existing data outcoming from the whole dunarobba area. on the heels of the recent literature, this paper is aimed to put a new light on the complexity of the fosso bianco paleoenvironment. . keywords: dunarobba clays; geotechnical properties; xrf; xrpd; early pleistocene 1. introduction inside the pliocene-pleistocene evolution of the tiberino basin (umbria, central italy, fig. 1), the older evolution phases were testified by the diffuse occurrence of clayey sediments, particularly in the southern sector. deposits were associated to lacustrine environment, from the ancient idea of the “tiberino lake” (lotti, 1917, 1926), to the definition of the informal “fosso bianco” unit (ambrosetti et al., 1995a; basilici, 1997), finally to the recent hypothesis of a “paleo-ancient lake” (medici & gliozzi, 2008; spadi, 2018; spadi et al., 2018a, 2018b), a relic from the late messinian salinity crises. in this scenario, the dunarobba area was always considered one of the key-point. the clayey deposits widely crop out in the area and they were studied since the beginning of the 20th century, due to the cultivation of lignite mines until 1950, and the production of bricks from 1950 onwards (fig. 2; cerquaglia, 1996). in this area, at about the half of eighties, the dunarobba fossil forest (dff in figure 1) was discovered, which is now considered one of the most relevant geosites in italy, due to the preservation in life’s position of more than forty mummified trunks, buried inside lacustrine clay deposits. dunarobba is one of the few sites in the world yielding mummified and upright fossil forests, including (regardless to age) axel heiberg island, in the arctic region of canada (45-40 ma: bigras et al., 1995; williams et al., 2008), the bukkabrany swamp cypress forest in hungary (7.7-6.3 ma: kàzmér, 2008; csaszar et al., 2009; erdei et al., 2009; gryc & sakala, 2010; erdei & magyari, 2011), and the stura di lanzo fossil forest, in nw italy (~3.0 ma: martinetto et al., 2007; vassio et al., 2008). due to its geological and environmental interest, the dunarobba fossil forest is under consideration for inclusion in the world heritage list (unesco), and most of the previous studies in the area converged on it. previous works, indeed, were mainly focused on sedimentological and paleontological features (manganelli et al., 1989, 1990, 2008; biondi & brugiapaglia, 1991; esu & girotti, 1991; martinetto, 1994; ambrosetti et al., 1995b, 1997; basilici, 1997; ciangherotti et al., 1998; manganelli & giusti, 2000; medici & gliozzi, 2008; marti https://doi.org/10.26382/amq.2018.14 88 fig. 1 geographic localization and simplified geological scheme for the study area. cnd=cava nuova; dff=dunarobba fossil forest; ct=cava toppetti; fb=fosso bianco (see text for details). baldanza a. et al. 89 fraction (loam range) or with clay fraction (paleosol levels and clay range strata containing the tree trunks). these facies associations are strictly comparable with the sedimentological restoration proposed by ambrosetti et al. (1995b, 1997) and basilici (1997). the originary location of boreholes is shown in figure 2. since it was discovered (or rediscovered), the dunarobba fossil forest began to show preservation problems, not only directly related to weathering (baldanza et al., 2009; martinetto et al., 2014). among the factors listed by valentini et al. (1997) as responsible for the preservation of fossil trunks, the main and, unfortunately, the only strongly modified by excavation were the sealing properties of the clay mass. unfortunately, in order to preserve the geosite, new invasive analyses are avoided inside the perimeter of the dunarobba fossil forest from 1995 onwards. nonenetto et al., 2014; spadi, 2018; spadi et al., 2018a, 2018b), on both the site area and the fosso bianco unit outcropping area. nonetheless, only few researches have conducted integrated multidisciplinary study. a research, carried out by valentini et al. (1997), was aimed to define the geological, hydrogeological and geochemical processes, which allowed the preservation of unaltered wood, making the dunarobba fossil forest an outstanding example of natural analogue, in the perspective of evaluating the confinement conditions of geological sites for radioactive waste disposal. barbieri et al. (1997) and bozzano et al. (2000) presented a set of geotechnical and mineralogical data obtained on samples collected from four boreholes and one open pit quarry, defining two main facies: deep lacustrine and swampy lacustrine coast facies associations. the latter was characterized by samples with abundant sandy fig. 2 evolution of the cava nuova quarrying area (cnd) and of the dunarobba fossil forest area (dff) through time. positions of stratigraphic sections and wells are reported. new integrate data from dunarobba clay deposits theless, due to the enlargement of neighbouring excavation area starting from 2011, new outcrops of clayey deposits were discovered in the surrounding area, only partly investigated during previous research activities. in this framework, a new geognostic campaign was carried out between 2011 and 2012, making disposable lithostratigraphic, sedimentological, geological-technical and chemical-mineralogical data in the neighbouring cava nuova (cnd in figure 1) area. the present work by using an integrated multidisciplinary approach illustrates and discusses new and old data from the dunarobba fossil forest area aiming to better understand some of the features of the "fosso bianco" lacustrine stage during the latest evolution of the tiberino sedimentary basin, to try to re-discuss age constrains, and to propose some hypothesis on sediment provenance, based on mineralogical and sedimentological analyses. although the preservation problems and the possible protection interventions are beyond the aims of this paper, all data collectable in this area are crucial not only for the correct paleoenvironmental restoration and geological evolution of the tiberino basin, particularly at the beginning of early pleistocene, but also in the light of the dunarobba fossil forest preservation strategies. 2. geological settings the study area is situated in southern umbria, central italy, inside the present-day southern tiber valley (fig. 1). through the pliocene and the pleistocene, this area pertained to the southwestern branch of the tiberino basin (also indicated as south tiberino basin), one of the nw-se trending extensional basins, roughly parallel to the apennine chain in lifting which characterized the evolution of northern apennine from miocene to recent (barchi et al., 1991; martini & sagri, 1993). the geological and stratigraphic model for the south tiberino basin evolved through time, from the initial idea of the fill up of a wide lake (the “tiberino lake”: lotti, 1917, 1926) to the definition of a lithostratigraphic succession of informal units divided according to sedimentological and biochronological data (ambrosetti et al., 1995a, 1995b; basilici 1997, 2000a, 2000b). now substantial agreement lays on the individuation of two main depositional cycles: 1) the lacustrine phase, pliocene to early pleistocene in age, and 2) the alluvial plain phase, early pleistocene to middle pleistocene in age. relationships among units belonging to the two cycles are both marked by faults and/or by unconformities (ambrosetti et al., 1995a; basilici, 1997). the uppermost cycles is largely represented by the “s. maria di ciciliano” unit and, locally, by the “acquasparta” unit (ambrosetti et al., 1995a; basilici, 1997). for an updated review and the state of the art, as well as for more detailed geological and stratigraphic schemes, we remind to martinetto et al. (2014, 2017). the dunarobba area lies inside the lowermost cycle and belongs to the informal fosso bianco unit, which outcropping part is attributed to the piacenzian-gelasian interval according to magnetostratigraphy (abbazzi et al., 1997). the unit was mainly associated to a deep lacustrine environment with prevailing clay sedimentation (facies association a: ambrosetti et al., 1995a, 1995b, 1997; basilici, 1997). locally, clayey silts alternated to wavyand/or cross-laminated silty sand laminae, parallel-laminated silty clay, lignitebearing clay deposits, and lenticular sand bodies crop 90 fig. 3 panoramic view of the cava nuova quarry area, as it appeared in january, 2012. >>>>> fig. 4 cava nuova sedimentological-lithostratigraphic section. facies associations refer to basilici (1997). baldanza a. et al. 91 new integrate data from dunarobba clay deposits 92 fornaci briziarelli marsciano quarry, is the accessible outcrop of fosso bianco unit closest (0.5 km) to the dunarobba fossil forest. it was recently measured and sampled, for a total thickness of 44 m. other 16 m, in continuity with the uppermost part, were previously described (ambrosetti et al., 1995b, 1997; basilici, 1997), while other six surveys wells were realized recently in the same area (figs. 2, 5, 6). sedimentological and geological features of some selected sections are shown in figure 5. out. they were interpreted as gilbert type delta deposits (facies association b), marshy lacustrine shore deposits (facies association c1, lithofacies a-e), and sandy lower shoreface deposits (facies association c2, lithofacies fi), respectively (ambrosetti et al., 1995b; basilici, 1997). a fourth type of deposits (facies association d), related to distal alluvial fan environment, is somehow associated to the same depositional cycle, although it was firstly indicated as “ponte naja” unit (ambrosetti et al., 1995a; basilici, 1997). the cava nuova section (figs. 3, 4), inside the fig. 5 comparison of selected lithostratigraphic columns in the dunarobba area from recent and further data. baldanza a. et al. formed, including soil particle density measurement, particle-size analysis, atterberg limits and organic matter content, following the astm d7263, astm d422, iso/ ts 17892-12:2004 and astm d2974 standards, respectively. all the analyses were performed at the applied geology laboratory (department of physics and geology, university of perugia). although the european standard (cen iso/ts 17892-12 2004) requires the cone penetrometer technique for liquid limit determination and indicates the casagrande cup as an alternative method, the latter was used in the present work. despite the casagrande cup method is much operator depending than the cone penetrometer device (e.g., di matteo, 2012; di matteo et al., 2016), it has been chosen here in order to compare data with those presented by previous works (candio et al., 1992; barbieri et al., 1997; bozzano et al., 2000). 3. materials and methods a preliminary facies description was carried out directly on the field, and a meter-stepped sampling was performed, with the collection of 44 samples, indicated as cnd both in the stratigraphic section and in the tables (fig. 4, tabs. 1-4). all samples were considered for microfossil content. about 500 g of each sample were washed in a hydrogen peroxide solution 30% in water and filtered through a satylon 63 μm sieve. the retained material was dried and observed under a stereomicroscope model nissan optical equipped with optical fibres. micropaleontological investigations allowed to identify on washed residues the biological component (mainly ostracod valves and molluscs). on twelve samples, selected according to the preliminary facies description, sedimentological and geotechnical analyses were per 93 fig. 6 schematic distribution of facies across the cava nuova and the fossil forest areas. landslide and anthropically-modified sectors are also perimetered. new integrate data from dunarobba clay deposits the selected twelve samples were also analyzed for determining their chemical and mineralogical compositions. major, minor and trace chemical components of the selected samples were determined by x-ray fluorescence (xrf) on pressed powder pellets utilizing an arl 9400 xp+ sequential x-ray spectrometer under the instrumental conditions reported in lezzerini et al. (2013). within the range of the measured concentrations, the analytical uncertainties are <5% for all the components except for na2o, p2o5, cao, tio2 and mno which may occasionally attain <10% for very low concentrations (lezzerini et al., 2013, 2014). the total amount of volatile components was determined as loss on ignition (loi in 105-950°c temperature range). the co2 content was measured by using the calcimetry method (leone et al., 1988) on 300 mg of finely powdered samples previously dried at 105±5°c. the difference between loi and co2 values was entirely ascribed to structural water (h2o).the qualitative mineralogical composition of the selected samples was obtained by xray powder diffraction analysis (xrpd) using a diffractometer with a bragg-brentano geometry. xrpd patterns were recorded using a philips pw 1730 automatic diffractometer with the following settings: cukα radiation obtained at 40 kv and 20 ma; slits: 1° divergence and scatter, 0.2 mm receiving; scan speed: 1°2θ/min; step size of 0.2°θ and counting time of 2s per step. mineralogy of bulk samples was investigated on randomly oriented whole-rock powder. oriented mounts of the <2μm fraction deposited on glass slides (2 mg/cm2: lezzerini et al., 1995; moore & reynolds, 1997) were used in order to identify the clay mineral assemblages. the clay mineral assemblage was studied on mg2+ and k+ saturated oriented aggregates of the <2μm fraction. the mg2+ saturated specimens were measured in air-dried (ad) and glycolated (eg) states. for some mg2+-saturated mounts, glycerol solvation was also performed. k+ saturated mounts were measured in air-dried conditions and after heating at 60, 110, 300 and 550°c. the basal reflections of clay minerals (including mixed-layer phases) were analyzed by diffrac.eva suite for phase analysis. the xrpd analysis of the main phyllosilicates was carried out following the procedures described by moore & reynolds (1997). quantitative mineralogical composition of the selected samples was obtained by combining xrf and xrd data as suggested by leoni et al. (2008). 4. cava nuova section integrated data 4.1. sedimentological and geotechnical features on the bases of lithological features, three main intervals are recognized already starting from the description on the field (figs. 3, 4): interval 1 (from the base of the section up to 23 m): silty clay deposits, massive to slightly parallel-laminated. fossil record is represented by rare gastropods, ostracods, bivalves, plant remains (leaves and wood’s fragments). thin horizons of vegetal remains (“lignite” s.l.) and high-organic clay, black to deep brown in colour, also occur. in the interval between 6 and 19 meters, iron -enriched reddish horizons, crusts and nodules are common inside clay, as reported by gallo et al. (2014). studies are still in progress, and the preliminary data associated these features to fe-carbonate (feco3, siderite). deposits in which nodules occur are associated to a relatively deep lacustrine environment, below the wave base; particularly in the lowermost section, features already correspond to these reported by basilici (1997) for facies association a. nonetheless, the presence of siderite crusts and nodules looks here particularly pervasive, on respect to the local, occasional occurrence already reported (ambrosetti et al., 1995b, 1997; basilici 1997). studies on the origin and meaning of siderite nodules are still in progress, and their complete descrip 94 tab. 1 sedimentological and geotechnical data of selected samples. index properties of the cnd soil samples are reported from the bottom (cnd1) to the top (cnd42) of the section. ll = liquid limit; pl = plastic limit; pi = plasticity index. pi is the difference between the liquid limit and the plastic limit (pi = ll-pl). soils with a high pi tend to be clay, those with a lower pi tend to be silt. in case of pi=0, soils are considered to have little/no clay or silt and called non-plastic soil. a soil is also considered non-plastic when ll or pl cannot be determined (n.p.). gs = specific gravity (pycnometer test); uscs = unified soil classification system (ch = clay of high plasticity ll > 50; cl = clay of low plasticity ll <50). samples cnd42 and cnd42b refer to the same bed, and are reported as an example of variability in sand/silt/clay fractions according to lateral facies variation. baldanza a. et al. tion is beyond the aims of this paper: at the moment, we choose to assign siderite-enriched layers to a local, not yet described variant inside facies association a of former authors. interval 2 (from 23 m to 38 m): silty clay deposits, alternated to fine sand and/or silty beds. sands are usually ripple-laminated. the same thin horizons made of vegetal remains (from charcoal to decimetric wood fragments), described in interval 1, as well as the highorganic darkish clay, are still commonly documented inside clay, as well as the occurrence, although less frequent, of iron-enriched reddish horizons. deposits are still referable to a lacustrine environment, showing clear shallowing upward trend, intermittent interaction with wave motion and re-sedimentation processes. also these deposits can be inserted in the facies description of basilici (1997): sandy/silty laminated beds are organized as coupled lithofacies f-g, inside the facies associations c2, while silty clay beds are still referable to facies associations a. we assume interval 2 may probably represent a transition between these two facies associations. interval 3 (from 38 m to 44 m): in this interval, deposits are characterized by alternations of sand and silt, from parallel-laminated to cross-laminated. plant remains, frequently including leaves, are common as well as lignite horizons. deposits are associated to a lake margin subjected to wave motion, and can be still assigned to some features of facies association c2 of basilici (1997), although only lignite beds were previously reported. the same facies variation, as well as the same depositional architecture, are detectable in the six welllogs all-around the cava nuova section (fig. 5), although the transition, represented by interval 2 in the main section, is here less defined. these entire supplementary sections grade from clay deposits (presumably referable to relatively deep lacustrine facies) towards sand and silt coastal deposits, locally enriched in vegetal remains and/or high-organic sandy clay. minor variations are imputable both to lateral facies variation and tectonics (fig. 5). geotechnical data are useful to carry out an integrated analysis with sedimentological and mineralogical ones. table 1 summarizes the collected geotechnical data for the 12 soil samples from the cava nuova section. grain size analyses confirm the preliminary field description, with occurrence of three main distributions. lowermost samples (interval 1), approximately until meter 25 (cnd25 in table 1), show constant percentages of clay (about 60%) and silt (about 40%) fractions. the silty component increases in the intermediate section (interval 2), while the sand fraction, which is steadily less than 1%, prevails in the last meters (interval 3). figure 7 shows the location of soils on skempton’s activity chart taking into account also the characteristics of soils published by candio et al. (1992) and barbieri et al. (1997), also belonging to fluvial-lacustrine deposits of dunarobba fossil forest area. soil samples of cava nuova falls along the 0.7 activity (a) line and are characterized by high to very high swelling potential; they fall in the transition zone between deep lacustrine associations and swampy coast facies as defined by barbieri et al. (1997). moving from the bottom to the top of the cava nuova section, pi values tend to gradually increase up to the medium part of the section (interval 1), then they decrease upward reaching about 36% in interval 2 and 24% in interval 3, where -due to the low siltclay fraction -a reduction of about 20 percentage points is observed in the last meters. although minimal variations in grain size distribution are also related to facies variability, this fact does not affect neither the general trend nor the distribution within the chart of figure 7. samples 42 and 42b (tab. 1) are reported as an example: index properties depend from the percentage of clay fraction rather than from a difference in clay mineralogy. 4.2. fossil content throughout the section (fig. 4), the fossil content is very poor and represented by rare freshwater gastropods (mainly emmericia umbra specimens) and bivalves, and by ostracods. the ostracod assemblages, although very poor, found along the cava nuova section are mainly represented by the occurrence of genera belonging to the candonidae family (candona neglecta and caspiocypris group), by the spotted occurrence of cytherissa lacustris, and by the dominance of cyprideis torosa in uppermost samples. the new species of caspiocypris, recently identified (inside both fb and ct sections, see figure 1) by spadi et al. (2018a), and considered as endemic of the grey clays of fosso bianco unit, also occur through the cava nuova section. particularly, 95 fig. 7 skempton’s activity chart (modified after williams & donaldson, 1980) for soils in table 1 and those from candio et al. (1992). data from barbieri et al. (1997) were elaborated from original graph (only boundaries of data were represented). new integrate data from dunarobba clay deposits 96 caspiocypris basilicii and caspiocypris tiberina are documented from the base, followed by caspiocypris tuderis and caspiocypris posteroacuta starting from samples cnd12 and cnd 23 respectively. in the interval 1 (facies association a), the caspiocypris group dominates the assemblages, only with few specimens of c. neglecta. a sharp decrease in caspiocypris spp. abundance is detected from sample cnd24 (about 24 m from the base of the section) onwards, in correspondence of the progressive increase in the sandy fraction and environmental energy, evidenced by wave ripples and cross laminations structures. from sample cnd24 to cnd39 (interval 2), species of the caspiocypris group occurs sporadically, with very low abundances. from sample cnd40 (deposits of interval 3), a sudden increase in the abundance of the ostracods is noted: assemblages are represented by cyprideis torosa (90%) and, for the remaining 10%, by c. neglecta and c. basilicii. thus, c. torosa characterizes assemblages associated to shallow lake/lake shore paleoenvironmental condition. with regard to the taxon cytherissa lacustris, it is found inside interval 1 and interval 3 with two isolated presence (samples cnd 15 and cnd 42); the low frequencies (no more of 5 valves) suggest a passive transport (wind action and/or dispersion by birds). 4.3. chemistry and mineralogy major, minor and trace chemical data are reported in tables 2 and 3, respectively. the observed values indicate a relatively homogenous chemical composition for all the studied samples through the stratigraphic sequence, except for cnd1, cnd4 and cnd15. in detail (tab. 2), at the bottom of the sequence the samples cnd1 and cnd4 exhibit the highest levels of co2 and cao, as well the lowest sio2 content. as a rule, sio2 and al2o3 slightly increase upwards, while contemporarily cao tend to decrease. this datum agrees with the increase upwards in the sandy fraction, enriched in quartz and feldspars. on the contrary, the sample cnd15, in the middle of the sequence, shows a very low amount of cao, with consequently high tenor of the other chemical components. finally, noteworthy is that fe2o3, which can be considered slightly constant through the section, ranges between 5.68 (cnd15) and 10.60 wt.% (cnd25): iron is probably a significant component in sediments and/or originary water, and variations are related to the occurrence of levels enriched in siderite nodules. according to major and minor element trends, trace element keep comparable levels over the sequence; an exception is represented by sample cnd15, characterized by low sr, and high cr, ni and ba, due to its high clay/silt+sand ratio (see tab. 1). nonetheless, barium keeps relatively high values throughout the section. the derived rb/sr ratio (tab. 3), almost show the same trend, allowing to identify a marked peak at sample cnd15. tab. 2 major and minor elements of the analyzed samples (wt.%). tab. 3 trace elements of the analyzed samples (ppm). baldanza a. et al. based on x-ray diffraction analysis on oriented mounts (fig. 8), the clay mineral assemblage is due to illite (10 å), kaolinite (7 å) and expansible minerals (also detectable from the skempton’s activity chart: fig. 7); in particular, the latter ones consist in illite/ smectite mixed layers (according to cesarano et al., 2018). the quantitative mineralogical composition determined by combining xrpd and xrf data (tab. 4) evidence a slight decreasing of calcite with a concomitant increasing of quartz contents over the sequence, from bottom to top. out of trend is the sample cnd15, for which the lower calcite and the higher quartz tenors are calculated. 4.4. paleoenvironmental restoration facies associations recognized in the cava nuova area are only partly comparable with these formerly described (ambrosetti et al., 1995b, 1997; basilici, 1997). on the other hand, swamp lacustrine coastal deposits looks circumscribed at the dunarobba fossil forest area. all the sedimentological, geotechnical and paleoecological data from the cava nuova section confirm the description and interpretation of facies initially made on the field, and the paleoenvironmental transition from relatively deep lake to coastal lacustrine is reliable. the lowermost section is characterized by fine-grained sediments (clay and silt), indicating a very low water energy and prevalence of decantation processes. the oligotypic assemblages lead to reconstruct the physical and chemical paleoenvironmental parameters. the data on ostracofaunas agree with those reported by spadi (2018) and spadi et al. (2018b), where the new proposed caspiocypris species are reported as endemic of the “paleolake tiberino”. more generally, the common occurrence in assemblages of caspiocypris group indicates deep lacustrine condition, with a minimum depth of at least 50 m (spadi et al., 2018b), or >40 m (ruiz et al., 2013). on the other hand, c. neglecta is widespread in springs, brooks and ponds connected to springs, and lakes (from shallow littoral to great depths).the species is distributed throughout the holarctic (meisch, 2000). the lake was characterized by cool and relatively deep waters, and by a silty to clayey floor, grading upwards to shallower depths, with higher water energy, relatively warmer temperature, and a coarse-grained (sandy/silty) floor. candona neglecta, as well as some species of caspiocypris (as c. pontica), tolerate very low salinity conditions (0.5-6‰: medici & gliozzi, 2008; spadi et al., 2018a; 2018b); c. neglecta can also sustain low oxygen values (meisch, 2000; ruiz et al., 2013), and prefers alkaline to weakly acid ph (ruiz et al., 2013). basin waters were probably moderately to well oxygenated, showing low salinity (between 0.5 and 6‰), neutral ph and low concentration of caco3. as lowermost clay samples are enriched in both co2 and calcite (tabs. 2, 4), this probably reflects the petrology of the mother rocks (source of sediments) rather than the water chemistry. this is not surprising, and a main provenance of fines from cretaceous to oligocene marly limestone units (figs. 1, 5) is highly probable. 97 fig. 8 xrd patterns collected on oriented mounts of cnd25 sample, saturated with mg++and k+, as example. tab. 4 mineralogical composition of bulk samples based on xrd and xrf data. new integrate data from dunarobba clay deposits 98 as the grain-size, the geotechnical parameters and the fossil record are steady throughout the lower section, stable and long-lasting deep lacustrine conditions can be assumed. time inferences imply considerations on stratigraphic constrains and sedimentation rate, which are discussed later (see § 5.2). deposits in the intermediate section (from sample cnd23 to cnd38) show a coarsening upward trend, with increase of the silt fraction, and the decrease in ostracods specimens. these data are interpreted in terms of shallowing trend and progradation of coastal systems; the prevalence of silty fraction in respect to the clay presumably conditioned the ecology of benthic forms. in the uppermost section (samples cnd39cnd43), the coarsening upward trend proceeds, with a prevailing sandy fraction, and a high content in plant remains, both testifying for the increase in energy and the reduction in depth. the fossil content is dominated by c. torosa, species related to transitional waters, shallower depths and/or sandy floor. deposits are associated to a wave-influenced lacustrine coastal environment. as for the lower section, chemical and physical parameters (water temperature, oxygen content, salinity, ph and concentration of caco3) seem to be steady in these two other portions. on the other hand, the increase in sandy portion clearly indicates a coastal shift: in this sense, a higher sedimentation rate is expected. throughout the section, mineralogical data show high values in trace elements values (tab. 3), particularly for barium, reaching 441 ppm in sample cdn15, but constantly over 200 ppm. as evidenced by muller (2014), barium appears to play an important role in bacterial metabolism, as well as iron and other trace elements. local condition could be related to the development of freshwater algal, protozoan, and bacteria, all organisms able to produce intracellular barite from geological material like clay (muller, 2009, 2014, with references therein). 5. discussion inside the wide outcropping area of “fosso bianco” unit (fig. 1), cava nuova section and dunarobba fossil forest areas represent single, although related, observation point, and this bias needs to be considered in generalizing the results of analyses. nonetheless, some points can be highlighted. 5.1. relationships between cava nuova and fossil forest areas a crucial point in every paleoenvironmental restoration lies on the originary vertical and lateral relation between deposits pertaining to the two areas of cava nuova and fossil forest, respectively. although they are really close (figs. 2, 5, 6), facies cropping out in the two areas are almost different. a detailed facies description and redefinition is beyond the aims of this work, and we choose still to refer to facies associations proposed by previous authors (ambrosetti et al., 1995b, 1997; basilici, 1997, 2000b): nonetheless, some differences were remarked, and, in our opinion, a partial integration is probably needed. a simplified chart of facies cropping out (fig. 6) reveals how swampy lake margin deposits and wave-dominated lake margin deposits (facies associations c1 and c2 of basilici, 1997, respectively) seem to be confined to the two areas. both types of deposits overlay deep lacustrine deposits (facies association a, with variations: basilici, 1997), which are recognized only on quarry fronts and well-logs (fig. 5). in the fields all around (fig. 6), the occurrence of plant remains (mainly large wood fragments) were commonly documented (f. famiani, pers. comm. 2018), although they can be alternatively related to both types of lake margin. as firstly proposed by ambrosetti et al. (1995a) and basilici (1997), the relations between the two areas at least partly result from late pleistocene and holocene tectonics. as shown in the transect reconstructed across the cava nuova and the fossil forest areas (fig. 5), minor faults are documented only in the fresh-exposed quarry fronts, while, according to the facies distribution, deposits all-around the fossil forest look undisturbed. thus, a ne-sw striking fault, with a presumed transtensive component, associated to the main fault system (fig. 1) and dividing the two areas (cava nuova and dunarobba fossil forest), although reasonable, it is not directly detectable on the field and can only be presumed. moreover, the direction of movement and the amount of dislocations are not easy to quantify. as discussed later, and according to sedimentation models formerly proposed (ambrosetti et al., 1995b, 1997; basilici, 1997; martinetto et al., 2014; spadi et al., 2018b), the two types of lake margin could be strictly related, thus tectonics can be considered a secondary factor in present-day distribution of facies on the field. 5.2. stratigraphic constrains a definitive age attribution for deposits of fosso bianco unit cropping out in the dunarobba area is still debated. a time range from ~3.1 to ~2.0 ma is commonly accepted for the whole unit, although its base was never clearly identified, nor in outcrop or in wells. according to ambrosetti et al. (1995a), the southern branch of the tiberino basin accommodated ~1 km of postmiocene deposits; assuming, for the sedimentation rate, the mean values reported in the previous section, it implies a possible ~5 ma duration for deposition inside the basin. thus, fosso bianco unit could be extended downwards fairly closer to the miocene-pliocene boundary. on the other hand, only two sections were calibrated to magnetostratigraphic scale (abbazzi et al., 1997; pontini & bertini, 2000; pontini et al., 2002; martinetto et al., 2014): the cava toppetti section, near todi, and the fosso bianco section, south from dunarobba fossil forest (ct and fb in figure 1, respectively). as the first one documents the gauss (successive to kaena) matuyama (nearly successive to reunion) magnetostratigraphic interval (between about 2.8 and 2.02 ma), the second only records 87 m-thick reversal interval, calibrated to the gelasian portion of the matuyama chron (about 2.5-2.2 ma). pontini & bertini (2000), by meant of pollen record, also remark the occurrence of four short but clearly recognizable “climatic” phases, in which the climate oscillated between ”temperate-warm” (pollen zones ii and iv) and “subtropical humid” (pollen zones i and iii). these four baldanza a. et al. intervals took place between the 102 (or 100) and 82 isotopic stages (i.e.: between 2.56-2.52 and 2.16 ma). the recent phyletic revision of caspiocypris group lead on by spadi et al. (2018 a, 2018b), and their stratigraphic, although local, use, also shade a new light in the study of fosso bianco deposits. the tentative of phylogenetic relations within the caspiocypris species flock of the palaeolake tiberino suggested by spadi et al (2018a) evidenced that the appearance of c. tuderis is a remarkable local event that took place inside the lower (but not basal) early pleistocene (gelasian), in both cava toppetti and fosso bianco sections. inside cava nuova section, this event is documented in the middle portion of interval 1 (sample cnd12, fig. 4), where the assemblages are characterized by c. basilicii, c. tiberina and c. perusia, in the same stratigraphic position as in the other two sections. although this local event could be time-tansgressive, and new confirmations are expected, its relevance for local stratigraphy and correlations appears evident. as pointed out by previous authors, the deep lacustrine deposits (facies association a) inside fosso bianco unit record significant fluctuations in sedimentation rate, depending on the stratigraphic and the paleoenvironmental/paleogeographical situation (abbazzi et al., 1997; pontini & bertini, 2000; pontini et al., 2002; martinetto et al., 2014). average values vary from 14-15 cm/kyr at cava toppetti, to 21-28 cm/kyr at fosso bianco (ct and fb sections in fig. 1, respectively). according to these values, the c. tuderis local event should be dated to about 2.5-2.45 ma, in both the sections. assuming the same sedimentation rates for the lowermost, deep lacustrine deposits at cava nuova, the first 23 m could have been deposited in a time between about 80-100 kyr (sedimentation rate of 21-28 cm/kyr) and about 155-160 kyr (sedimentation rate of 14-15 cm/ kyr). thus, the deep lacustrine phase cropping out at cava nuova should be comprised between about 2.582.55 and 2.4-2.37 ma. thus, a gelasian age can be finally assumed also for the lowermost, deep lacustrine deposits (interval 1) cropping out at cava nuova. as the section shows a continuous facies transition inside a shallowing-upward trend (fig. 4), an almost continuous decreasing in age is also expected, with no major time gaps and hiatus. assuming the same sedimentation rate values also for intervals 2 and 3, the whole section (43 m) should record a 150 to 280 kyr time interval. that is, the top of the section should be dated between 2.4 and 2.3 ma. on the other hand, throughout that facies transition variations in sedimentation rate are expected. although the alternation of dryer and wetter intervals recorded in fosso bianco section seems not to find a direct sedimentological and/or paleontological correspondence at cava nuova (fig. 4), the lowermost section (interval 1 and part of interval 2) records cool water conditions, and it could be associated to pollen zone ii of pontini & bertini (2000). this hypothesis looks consistent with the geochemical peak in rb/sr ratio noted in sample cnd15 (tab. 3). this ratio may reflect mother rock compositions, as well as the sr content could result from different processes, such as primary carbonate productivity, or early diagenetic calcite dissolution. nonetheless, it could also be cautiously considered as indicative of the prevalence of physical or chemical weathering in the catchment area (for example, see xu et al., 2010). although data are too scarce to reconstruct a climatic trend, in our opinion the hypothesis that this peak could be related to a moment of cool/arid climate, which favoured physical weathering, and which falls shortly after the c. tuderis local event (around 2.45 ma), should be considered in paleoenvironmental restoration. in this way, part of interval 2 and interval 3 could be associated to at least part of pollen zone iii, and an age about 2.24 for the top of the section could be reliable. to assign an age to deposits from the fossil forest area is even more speculative; nonetheless, some hypotheses need to be considered. ambrosetti et al. (1995b), mainly on the base of paleoecologic/ paleoclimatic topics, firstly proposed a piacenzian age for the fossil forest. assuming the sedimentation rates previously discussed, and its top being not younger than 2.588 ma, the base of the composite section (extending from top of s2 to substrate in s1-s7 sections: fig. 5) should be dated between about 3.49 and 3.06 ma. it implies the fossil forest area records the very beginning of sedimentation inside the fosso bianco unit, which was never documented otherwise. the older deposits inside cava toppetti section, indeed, are dated to about 2.8 ma. in central italy, so ancient deposits were documented in the valdarno basin (napoleone et al., 2003), and in the eastern branch of the tiberino basin (fossil record inside the lignites of morgnano, attributed to triversa faunal unit: bizzarri et al., 2018, and references therein). although this hypothesis cannot be totally abandoned, some question arises. the presence of such old deposits in a restricted area, fairly close surrounded by younger (gelasian) deposits, and both older and younger deposits indifferently overlaid by the same lithostratigraphic unit (s. maria di ciciliano unit: ambrosetti et al., 1995a), can be justified only in terms of main tectonic displacement, occurring in a very short time interval (200 kyr) between gelasian and calabrian (early pleistocene tectonics). as synthesized in figure 1, the present geological setting seems to be mainly related to middle-late pleistocene tectonics, and to the occurrence of an important ne-sw oriented strike-slip area between dunarobba and acquasparta villages (see also geological schemes proposed by ambrosetti et al., 1995a, basilici, 1997, and spadi et al., 2018b). the same shallowing-upward trend, from deep lacustrine deposits to coastal deposits, is documented in both the cava nuova and fossil forest areas, and in both cases idealized composite stratigraphic sections do not record the occurrence of a second, superimposed cycle. that is, both situations appear to record a “final”, although local, evolutive step. this cannot be easily justified if the ages are significantly different, and the presence of several overlapping sedimentary cycles should be expected. on the bases of ostracofauna, spadi (2018) and spadi et al. (2018b) proposed deposits of the fossil forest area are almost coeval to the ponte naja unit (2.2-2.0 ma: abbazzi et al., 1997; pontini et al., 2002). as discussed in martinetto et al. (2014), the dunarobba 99 new integrate data from dunarobba clay deposits 100 fossil forest record, particularly pollen record from s2 section, can be also correlated with the pollen zone iii of fosso bianco section (pontini & bertini, 2000). in this way, cava nuova section and dunarobba fossil forest paleofloristic records were recomprised in the persistence of “humid thermophilous plant taxa of east asian affinity” (hutea) as “pliocene relics”, and inside their progressive disappearance through early pleistocene in southern europe, as proposed by martinetto et al. (2017). as the local trend of progressive decrease in depth, although with different evidences, is recorded in all the sections of the fossil forest and cava nuova areas (fig. 5), the hypotheses the two areas are coeval, and that both record the transition between pollen zones ii and iii, seem to be reasonable. as assumed for the cava nuova section, swampy coastal facies interval could be dated to about 2.4-2.2 ma; thus, the base of the composite section (s1-s7 in figure 5) should be positioned between about 2.95 and 2.8 ma. in the fosso bianco section, the pollen zone iii is associated to deep lacustrine clay deposits enriched in thin mudor debris-flows deposits, bearing vegetal remains (pontini & bertini, 2000; martinetto et al., 2014), which can be justified as resedimentation deposits from coastal areas enriched in vegetation, as documented in both the cava nuova and fossil forest areas. for all the exposed reasons, the time gap between deposits pertaining to the two areas (cava nuova and dunarobba fossil forest) and their related sections is reasonably minimum, and an average age comprised between 2.5 and 2.2 ma for the outcropping portion of fosso bianco unit in the area can be assumed. 5.3. comparison with former mineralogical and geotechnical data considering the distribution in figure 7, samples collected throughout the cava nuova section are comparable with the data of barbieri et al. (1997): thus, the belonging to the variability of fosso bianco unit sediments is clearly demonstrated. on the other hand, data from skempton’s activity chart does not allow a unique assignment to deep lacustrine (a) and/or swampy coast (c1) facies associations. moreover, our uppermost samples fall in the area of the graphic, although they are clearly associated to a wave-dominated coast. contrarily to what supposed by barbieri et al. (1997) and bozzano et al. (2000), this parameter does not fully express the facies variability inside the fosso bianco unit. otherwise, when considered together with numeric grain size distribution, it has a more direct correlation with sedimentological intervals described in the field. thus, if the sedimentological interpretation is needed, the method can be an additional tool for the analysis of either short sections or wide datasets. on regard to the mineralogical composition of clay fractions, significant bias occur when old and new data are compared, as well as in the comparison between “mineralogical” and ”geotechnical” content of clay. nonetheless, both geotechnical and mineralogical data highlight the uniformity in clay composition, while only the amount of the clay fraction varies throughout the section. this quite homogeneous composition throughout the section confirms the hypothesis of a steady supply from the same source area through time. however, the slight increasing of sandy fraction (consisting mainly in quartz) from bottom to top indicates a modification of sedimentation condition from deep to coastal environments, with intermittent inlets of terrigenous materials highlighted by the occurrence of quartz-rich levels in the middle of the sequence (see for example sample cnd15), becoming more frequent and even dominant upwards. 5.4. insights for the basin evolution from what discussed in the previous paragraphs, some paleoenvironmental, paleogeographic and geological implication can be proposed. measured sedimentological/geotechnical parameters, such as grain size and skempton’s activity for clay, show a linear trend throughout the section ranging from very high to high (activity ≃ 0.7), thus indicating a coarsening upward of deposits inside the basin rather than a clear variation of supply. this statement is supported by the overall uniformity in the mineralogy of clays, whose assemblage is due to constant level of illite/smectite, and kaolinite over the sequence. assuming a time interval of 150 to 280 kyr (for the deposition of the whole cava nuova section), or of 80 to 160 ky for sedimentation of the deep lacustrine clay alone, this homogeneity implies a long-lasting supply of sediments from the same feeding area. nonetheless, discontinuities in the material supply, suggested by the variability in sand-silt enriched levels, especially in the middle and in the upper part of the section, needs to be explained. this could imply the occurrence of occasionally climatic and/or tectonic events, determining the inlet of quartz-rich sediments. this trend is particularly clear for uppermost section (fig. 4). as pointed out in § 5.3, a local source for deposits is inferred: in this way, quartzrich fraction can derive by erosion of oligocene-miocene sandstone units (fig. 1). this wide paleoenvironmental and compositional homogeneity also lead to exclude a far source of sediments, such as a structured river environment. that is, resediments inside the basin derived from local, contiguous environments, such lake coasts and minor fan-delta. the deep lacustrine phase inside the fosso bianco unit (i.e.: the one documented by facies association a of basilici, 1997) can be considered as a stable, invariant, and long-lasting environment. such phase (and the fosso bianco unit as a whole) is characteristic of the south tiberino basin, and finds no equivalent in the other sectors of the basin, each one evolving through time in its peculiar way (ambrosetti et al., 1995a; coltorti & pieruccini, 1997; melelli et al., 2010; bizzarri et al., 2011, 2018; pucci et al., 2014; bucci et al., 2016; mirabella et al., 2018). on the bases of evidences provided by the ostracofaunas (medici & gliozzi, 2008; spadi, 2018; spadi et al., 2018a, 2018b), this lake can be properly considered a relic of late messinian -zanclean marine to brackish conditions (“paleo-ancient lake”), a water mass with altered salinity imprisoned into a continental basin, with no input-output dynamics. in fact, no data are available about the beginning of this phase, and maybe only real deep perforations could provide defini baldanza a. et al. tive information. on the other hand, the clear transition upwards from deep lake to coastal lake conditions, directly described in the cava nuova section, is also found in all the sections in the area (fig. 5). this datum needs to be discussed, and three main questions arise. first, this variation could reflect a climatic trend, as well as it may be driven by tectonics. as a second problem, it is not finally clear where, in the stratigraphic succession of fosso bianco unit, this variation takes place, if in the uppermost part or just at the end of its deposition. the third point is if this regressive trend marks the definitive change in environmental conditions (e.g.: the end of depositional cycle 1 and the transition to depositional cycle 2), or if phases of rise and fall of the lake’s level repeated through time. according to what discussed in § 5.2, the cava nuova and dunarobba fossil forest areas record the uppermost, but not final, sedimentation inside the fosso bianco unit. as deposits in the whole area can be considered nearly coeval, the outcrop conditions mainly derive from the late pleistoceneholocene evolution of the tiber valley. in northern sector (cava toppetti area: fig. 1), deep lacustrine sedimentation extends until about 2.0 ma. it is possible that the unconformity between the cycles 1 and 2 reasonably cut a sensible part of the lower cycle, particularly in the southern portion of the basin (ambrosetti et al., 1995a; basilici, 1997). inside the >800 kyr lasting sedimentation of fosso bianco unit, study sections (fig. 5) are relevant but only represent less than the 1/3 of the outcropping fosso bianco unit. they better photograph a single evolution phase, or the transition between two phases, rather than synthesize the whole sedimentological, climatic, stratigraphic variability inside the unit. shorter phases (high-order cycles) probably repeated through time, although they seem to be clearly detected only at fosso bianco (pontini & bertini, 2000; martinetto et al., 2014). the fossil record from plants (martinetto et al., 2014, 2017), vertebrates (abbazzi et al., 1997; pontini et al., 2002), and ostracofauna (spadi, 2018; spadi et al., 2018b), as well as the geological-sedimentological interpretation (ambrosetti et al., 1995a), suggest a general trend inside the “fosso bianco” cycle, from deep lacustrine to coastal facies. thus, fosso bianco unit (and the related units like ponte naja unit) document at least part of a 3rd order cycle. regarding what drove the changes, cava nuova section and dunarobba fossil forest somehow insert in the phase of global climatic instability, which characterized the gelasian stage, but they mainly record local changes. the longer persistence of some floristic species in central italy after the end of the piacenzian with respect to the northern part of this country, probably due to the intermediate pattern between climatic changes described for the central mediterranean littoral and the north apennine ones (martinetto et al., 2014, 2017), must be considered. according to martinetto et al. (2014) the remarkable fossil forest at dunarobba was produced by an ancient swamp vegetation dominated by glyptostrobus europaeus; trees grew in a wetland with high sedimentation rate, bordering the ancient lake, and both disappeared due to the establishment of well-drained paleoenvironmental conditions, testified by a paleosol profile (basilici, 1997). the successive restoration of wetland conditions was not sufficient for the preservation of in situ tree trunks (basilici, 1997). coastal facies associations, although different between cava nuova and fossil forest areas, were probably both related to a lowering phase in the lake’s level. the relative uniformity of the pollen curves (martinetto et al., 2014) suggests that the extra-local vegetation and climate remained stable for a long time span. all these data fit well with the mineralogicalpetrographic homogeneity we record in the cava nuova section, so the paleoenvironmental variation was probably better explained by local (or even regional) morphological changes induced by tectonics. tectonics probably led to a strong activity of faults at the boundary, producing a large sediment supply from the same feeding area, and causing the progradation of coastal lake systems and the fall in the level of the lake, as proposed by ambrosetti et al. (1995b) and basilici (1997). the data discussed herein, and their comparison with old and recent papers, lead to suggest this fall represented the main, somehow definitive, phase closing the lower depositional cycle. far from a definitive understanding and modelling of timing and evolution for the tiberino basin, what discussed in this paper ranks in the wake of the recent literature, which tries to shade new light on such problematic. furthermore, it is probably time to reconsider and partly revise the general geological, stratigraphic, and paleoenvironmental scheme for the fosso bianco unit. 6. conclusions inside the pliocene-pleistocene evolution of the tiberino basin, the vertical and lateral relations of deposits in the “fosso bianco” unit are a key-point and, unfortunately, they are still an open problem. the new collected data, far to dispel all doubts, put new light to better understand the paleoenvironmental features of at least part of the lacustrine phase. such long-lasting environment, although fairly structured, survived almost invariant for at least 2.1 ma. both the dunarobba fossil forest and the cava nuova areas record analogous depositional trend, from deep lake to coastal lake, although represented by different facies: this phase, lasting 150 to 280 ky, can find correspondence in the transition between pollen zones ii and iii documented in the “fosso bianco” section by pontini & bertini (2000) and correlated with the early gelasian. although new evidences are needed, this phase could continue towards the gelasian-calabrian boundary, until 2.2-2.0 ma. during the gelasian climatic instability, the system seemed to accommodate local variations rather than a global trend, as expected for the global datum of southern europe. starting from a section recording a continuous facies transition, this work proposed a multidisciplinary approach to better understand both sedimentologicalgeotechnical and mineralogical aspects. the analytical procedures reveal useful, and we expect they can be a tool to characterize other clayey soils outcropping in the 101 new integrate data from dunarobba clay deposits 102 baldanza a. et al. tiberino basin fluvio-lacustrine context, as well as in other paleolacustrine environments. acknowledgments we kindly thank dr. f. posati and dr. f. famiani for their support on the field, and dr. f. cavalcante and an anonymous reviewer for their precious comments and suggestions in improving the manuscript. references abbazzi l., albianelli a., ambrosetti p., argenti p., basilici g., bertini a., gentili s., masini f., napoleone g., pontini m.r. (1997) paleontological and sedimentological record in pliocene distal alluvial fan deposits at cava toppetti (todi, central italy). in: monegatti p. (ed), proceedings del xii convegno della società paleontologica italiana. bollettino della società paleontologica italiana, 36, 5-22. ambrosetti p., basilici g., capasso-barbato l., carboni m.g., di stefano g., esu d., gliozzi e., petronio c., sardella r., squazzini e. (1995a) il pleistocene inferiore nel ramo sudoccidentale del bacino tiberino (umbria): aspetti litostratigrafici e biostratigrafici. il quaternario, 8, 19-36. ambrosetti p., basilici g., ciangherotti a.d., codipietro g., corona e., esu d., girotti o., lo monaco a., meneghini m., paganelli a., romagnoli m. (1995b) la foresta fossile di dunarobba (terni, umbria, italia centrale): contesto litostratigrafico, sedimentologico, palinologico, dendrocronologico e paleomalacologico. il quaternario, 8, 465-508. ambrosetti p., basilici g., di filippo m., di maio r., gentili s., lombardi s., patella d., toro b., brozzetti f., cammarano f., cattuto c., ciotoli g.c., di giacomo b., etiope g, fisauli m., gregori l., piscitelli s., pontini r., ruspandini t. (1997) the stratigraphic, depositional, geomorphological and structural characteristics of the sediments which contain the fossil forest of dunarobba (ffd). in: valentini g., lombardi s., bozzano f., scarascia mugnozza g. (eds), analysis of the geo -environmental conditions as morphological evolution factors of the sand-clay series of the tiber valley and dunarobba forest preservation, eur 17479 en, final report, eur op, luxembourg, 9104. baldanza a., sabatino g., triscari m., de angelis m.c. (2009) the dunarobba fossil forest (umbria, italy): mineralogical transformations evidences as possible decay effects. periodico di mineralogia, 78, 51-60. barbieri m., bozzano f., duddrige g.a., grainger p., mottana a., scarascia mugnozza g., valentini g. (1997) studies of the natural barriers in the dunarobba forest area. in: valentini g., lombardi s., bozzano f., scarascia mugnozza g. (eds), analysis of the geo-environmental conditions as morphological evolution factors of the sand-clay series of the tiber valley and dunarobba forest preservation, eur 17479 en, final report, eur op, luxembourg, 144-211. barchi m., brozzetti f., lavecchia g. (1991) analisi strutturale e geometrica dei bacini della media valle del tevere e della valle umbra. bollettino della società geologica italiana, 110, 65-76. basilici g. (1997) sedimentary facies in an extensional and deep lacustrine depositional system: the pliocene tiberino basin, central italy. sedimentary geology, 109, 73-94. basilici g. (2000a) pliocene lacustrine deposits of the tiberino basin (umbria, central italy). in: gierlowski-kordesch e.h., kelts k.r. (eds), lake basins through space and time. aapg studies in geology, 46, 505-514. basilici g. (2000b) floodplain lake deposits on an early pleistocene alluvial plain (tiberino basin, central italy). in: gierlowski-kordesch e.h., kelts k.r. (eds), lake basins through space and time. aapg studies in geology, 46, 535-542. bigras c., bilz m., grattan d.w., gruchy c. (1995) erosion of the geodetic hills fossil forest, axel heiberg island, northwest territories. arctic, 48, 342-353 biondi e., brugiapaglia e. (1991) taxodioxylon gypsaceum (goppert) krausel in the fossil forest of dunarobba (umbria, central italy). flora mediterranea, 1, 111-120. bizzarri r., albianelli a., argenti, p. baldanza a., colacicchi r., napoleone g., (2011) the latest continental filling of valle umbra (tiber basin, central italy) dated to one million years ago by magnetostratigraphy. il quaternario 24(1), 51-65. bizzarri r., corrado p., magri d., martinetto e., esu d., caprai v., colacicchi r., napoleone g., albianelli a., baldanza a. (2018) palaeoenvironmental and climatic inferences from the late early pleistocene lacustrine deposits in the eastern tiberino basin (central italy). quaternary research, 90(1), 201221. bozzano f., parroni f., scarascia mugnozza g., valentini g. (2000) caratterizzazione geologicotecnica dei depositi continentali della “foresta fossile” di dunarobba (tr). atti del 5° conv. naz. giovani ricercatori di geologia applicata, cagliari 1996, 33-41. bucci f., mirabella f., santangelo m., cardinali m., guzzetti f. (2016) photo-geology of the montefalco quaternary basin, umbria, central italy. journal of maps. doi: 10.1080/17445647.2016.1210042 candio s., damiani a.v., federico a., setti m., veniale f., vinti g. (1992) caratterizzazione geotecnica e mineralogica di unità argillose dell’umbria. geologia applicata e idrogeologia, 27, 123-133. cerquaglia z. (1996) la foresta fossile di dunarobba. ediart, todi, pp. 106. cesarano m., bish d.l., cappelletti p., cavalcante f., belviso c., fiore s. (2018) quantitative mineralogy of clay-rich siliciclastic landslide terrain, sorrento peninsula, italy, using a combined xrpd and xrf approach. clay and clay minerals, 66(4), 353-369. ciangherotti a.d., esu d., girotti o. (1998) review of the history of the late neogene-early quaternary non-marine molluscs of italy. mededelingen nederlands instituut voor toegepaste geowetenschappen tno, 60, 491-498. coltorti m., pieruccini p. (1997) the southeastern tiber basin (spoleto, central italy): geology and stratigraphy of plio-pleistocene sediments. il quaternario, 10, 159-180. csaszar g., kazmer m., erdei b., magyar i. (2009) a possible late miocene fossil forest paleopark in hungary. notebooks in geology, 3, 11. brest, book 2009/03, chapter 11, (cg2009_book_ 03/11), 121-133. di matteo l. (2012) liquid limit of lowto mediumplasticity soils: comparison between casagrande cup and cone penetrometer test. bulletin of engineering geology and the environment, 71(1), 7985. di matteo l., dragoni w., cencetti c., ricco r., fucsina a. (2016) effects of fall-cone test on classification of soils: some considerations from study of two engineering earthworks in central italy. bulletin of engineering geology and the environment, 75(4), 1629-1637. erdei b., magyari e. (2011) late miocene plant remains from bükkabrany, hungary. studia botanica hungarica, 42, 135-151. erdei b., dolezych m., hably l. (2009) the buried miocene forest at bukkabrany, hungary. review of palaeobotany and palynology, 155, 67-79. esu d., girotti o. (1991) late pliocene and pleistocene assemblages of continental molluscs in italy. a survey. il quaternario, 4, 137-150. gallo g., baldanza a., bizzarri r., cavalazzi b., comodi p., frondini f., rigo m. (2014) the relevance of biosignatures in siderite-nodules: an example from quaternary continental deposits (tiberino basin, italy). eana 2014 abstract volume, edimburg, scotland. gryc v., sakala j. (2010) identification of fossil trunks from bükkabrany newly installed in the visitor centre of the ipolytarnòc fossil nature reserve (novohradnograd geopark) in the northern hungary. acta universitatis agriculturae et silviculturae mendelianae brunensis, 58, 117-122 kàzmér m. (2008) the miocene bükkábrány fossil forest in hungary -field observations and project outline. in: galácz a. (ed.), 125th anniversary of the department of palaeontology at budapest university -a jubilee volume. hantkeniana, 6, 229 -244. leone g., leoni l., sartori f. (1988) revisione di un metodo gasometrico per la determinazione di calcite e dolomite. atti della società toscana di scienze naturali memorie serie a, 95, 7-20. leoni l., lezzerini m., saitta m. (2008) calcolo computerizzato dell’analisi mineralogica quantitativa di rocce e sedimenti argillosi basato sulla combinazione dei dati chimici e diffrattometrici. atti della società toscana di scienze naturali memorie serie a, 113, 63-69. lezzerini m., sartori f., tamponi m. (1995) effect of amount of material used on sedimentation slides in the control of illite “crystallinity” measurements. european journal of mineralogy, 7, 819-823. lezzerini m., tamponi m., bertoli m. (2013) reproducibility, precision and trueness of x-ray fluorescence data for mineralogical and/or petrographic purposes. atti della società toscana di scienze naturali memorie serie a, 120, 67-73. lezzerini m., tamponi m., bertoli m. (2014) calibration of xrf data on silicate rocks using chemicals as in -house standards. atti della società toscana di scienze naturali memorie serie a, 121: 65-70 doi: 10.24.24/astsn.m.2014.16. lotti b. (1917) l'antico lago tiberino e le ligniti dell'umbria. miniera italiana, 1, 274-275. lotti b. (1926) descrizione geologica dell'umbria. memorie per la descrizione della carta geologica d’italia, 21, 1-320. manganelli g., giusti f. (2000) the gastrocoptids of the fossil forest of dunarobba (central italy) and a preliminary revision of the european tertiary nominal species of albinula and vertigopsis (gastropoda pulmonata: gastrocoptidae). bollettino della società paleontologica italiana, 39, 5582. manganelli g., benocci a., esu d., giusti f. (2008): staurodon cianfanellianus n. sp. (gastropoda pulmonata), a new nesopupine vertiginid snail from the middle-late pliocene fossil forest of dunarobba (central italy). bollettino della società paleontologica italiana , 47, 211-214. manganelli g., delle cave l., giusti f. (1989) notulae malacologicae, xliv. strobilopsidae (gastropoda, pulmonata), a family new to the villafranchian land snail fauna of apenninic italy. basteria, 52, 3-13. manganelli g., giusti f., delle cave l. (1990) notulae malacologicae, xlvii. lauriinae (gastropoda: pulmonata, orculidae/pupillidae) from the villafranchian of the peninsular italy. basteria, 53, 87-103. martinetto e. (1994): paleocarpology and the ‘in situ’ ancient plant communities of a few italian pliocene fossil forests. in: matteucci r., carboni m.g., pignatti j.s. (eds), studies on ecology and paleoecology of benthic communities. bollettino della società paleontologica italiana, spec. vol., 2, 189196 martinetto e., scardia g., varrone d. (2007) magnetobiostratigraphy of the stura di lanzo fossil forest succession (piedmont, italy). rivista italiana di paleontologia e stratigrafia, 113, 109-125. martinetto e., bertini a., basilici g., baldanza a., bizzarri r., cherin m., gentili s., pontini m.r. (2014) the plant record of the dunarobba and pietrafitta sites in the plio-pleistocene palaeoenvironmental context of central italy. alpine and mediterranean quaternary, 27, 29-72. martinetto e., momohara a., bizzarri r., baldanza a., delfino m., esu d., sardella r. (2017) late persistence and deterministic extinction of ”humid thermophilous plant taxa of east asian affinity” (hutea) in southern europe. in: françois l, bruch a.a., utescher t., spicer r.a., spicer t. (eds), reconstructing cenozoic vegetation from proxy data and models a neclime synthesis. palaeogeography palaeoclimatology palaeoecol 103 new integrate data from dunarobba clay deposits ms. received: august 17, 2018 final text received: december 1, 2018 104 ogy, 467, 211-231. doi: 10.1016/j.palaeo.2015.08.015 martini i.p., sagri m. (1993) tectono-sedimentary characteristics of late miocene quaternary extensional basins of the north apennines, italy. earth science reviews, 34, 197-223. medici m.c., gliozzi e. (2008) preliminary data on the freshwater ostracods from the middle-late pliocene tiberino “palaeo-ancient lake” (umbria, central italy). atti museo civico di storia naturale trieste, suppl., al. 53, 39-48. meisch c. (2000) freshwater ostracoda of western and central europe. spektrum academischer, heidelberg, berlin, pp. 522. melelli l., barchi m., brozzetti f., lupattelli a., mirabella f., pazzaglia f., pucci s., saccucci l. (2010) morphotectonic evolution of high tiber valley (umbria, italy) related to an active low angle normal fault segmentation. rendiconti online della società geologica italiana, 11, 629-630. mirabella f., bucci f., santangelo m., cardinali m., caielli g., de franco r., guzzetti f., barchi m.r. (2018) alluvial fan shifts and stream captures driven by extensional tectonics in central italy. journal of the geological society. doi: 10.1144/jgs2017-138 moore m.d., reynolds r.c. (1997) x-ray diffraction and the identification and analysis of clay minerals. oxford university press, oxford, uk, pp. 378. muller b. (2009) impact of the bacterium pseudomonas fluorescens and its genetic derivatives on vermiculite: effects on trace metals contents and clay mineralogical properties. geoderma, 152(12), 94-103. doi: 10.1016/j.geoderma.2009.07.025 muller b. (2014) uptake of barium from vermiculite by the bacterium pseudomonas fluorescens new indications for barium as a palaeoproxy. the open geology journal, 8, 118-123. napoleone g., albianelli a., azzaroli a., bertini a., magi m., mazzini m. (2003) calibration of the upper valdarno basin to the plio-pleistocene for correlating the apennine continental sequences. il quaternario, 16, 131-166. pontini m.r., albianelli a., basilici g., bertini a., napoleone g. (2002) pollen record and magnetostratigrapy of the middle-late pliocene lacustrine sequence in the tiberino basin (central italy). bollettino della società geologica italiana, special volume 1-2002, 467-472. pontini r., bertini a. (2000) late pliocene vegetation and climate in central italy: high resolution pollen analysis from the fosso bianco section (tiberino basin). geobios, 33, 519-526. pucci s., mirabella f., pazzaglia f., barchi m.r, melelli l., tuccimei p., saccucci l. (2014) interaction between regional and local tectonic forcing along a complex quaternary extensional basin: upper tiber valley, northern apennines, italy. quaternary science reviews, 102, 111-132. ruiz f., abad m., bodergat a.m., carbonel p., rodriguez-lazaro j., gonzalez-regalado m.l., toscano a., garcia e.x., prenda j. (2013) freshwater ostracods as environmental tracers. international journal of environmental science and technology, 10, 1115-1128. spadi m. (2018) ostracod assemblages from the palaeolake tiberino (piacenzian-gelasian, central italy): a synthesis. alpine and mediterranean quaternary, 31, 193-197. spadi m., gliozzi e., medici m.c. (2018a) a pliopleistocene caspiocypris species flock (candoninae, ostracoda) from the palaeolake tiberino (umbria, central italy). journal of systematic palaeontology, 16(5), 417-434. doi: 10.1080/14772019.2017.1310143 spadi m., gliozzi e., medici m.c. (2018b) early pleistocene (gelasian) non-marine ostracods from the dunarobba fossil forest (tiberino basin, umbria, central italy). palaeontology. id pala-01-18-4140oa.r2 valentini g., lombardi s., bozzano f., scarascia mugnozza g. (1997) analysis of the geoenvironmental conditions as morphological evolution factors of the sand-clay series of the tiber valley and dunarobba forest preservation. eur 17479 en, final report, eur op, luxembourg, pp. 211. vassio e., martinetto e., dolezych m., van der burgh j. (2008) wood anatomy of the glyptostrobus europaeus “whole-plant” from a pliocene fossil forest of italy. review of palaeobotany and palynology, 151, 81–89. williams a.a.b., donaldson g. (1980) building on expansive soils in south africa. 4th international conference on expansive soils, denver, proceedings, vol. 2, 834-840. williams c.j., mendell e.k., murphy j., court w.m., johnson a.h., richter s.l. (2008) paleoenvironmental reconstruction of a middle miocene forest from the western canadian arctic. palaeogeography palaeoclimatology palaeoecology, 261, 160176. xu h., liu b., wu f. (2010) spatial and temporal variations of rb/sr ratios of the bulk surface sediments in lake qinghai. geochemical transactions, 11, 3. geochemicaltransactions.com/content/11/1/3 baldanza a. et al. amq_28(1) coloph 3.pub villafranca d’asti trip the first trip of the turin aiqua congress (february 25, 2015) has taken place in villafranca d'asti and surroundings. it was organized by m. gabriella forno and marco gattiglio that investigated the stratigraphy and structural setting of the “villafranchian succession”, respectively. a relatively large group of researchers also contributed to the route planning: adele bertini (palynological analyses of the sediments), cesare comina (geophysical survey of the succession), alfredo doglione (detailed geological survey of the type-area), andrea irace (setting of the pliocene-pleistocene succession in the regional framework), franco gianotti (graphic design), edoardo martinetto (fossil plants), alberto mottura and benedetto sala (fossil vertebrates) and donata violanti (marine microfossils). the trip focused on two main topics (fig. 1): the stratigraphy of the “villafranchian-succession” type-area, that was observed in the morning (stop 1, 2, 3), and the structural setting along the t. traversola deformation zone, in the afternoon (stop 4, 5, 6). the relaxed discussions regarding the different topics were particularly appreciated by both conveners and attendees. the first stop focused on littoral sand (asti sand) and deltaic front sand (ferrere unit) outcropping at ronco (san damiano d’asti, in se corner of the typearea) (stop 1). here the sediments are particularly rich in marine fossils, also collected by the participants in the field trip. the second stop concerned deltaic plain silt (swamp deposits rich in plant remains) and sand (in which numerous vertebrate fossils were collected over time) that are visible near cascina san martino aiqua congress in turin fieldtrips february 24th 26th, 2015 the plio-pleistocene continental record in italy: highlights on stratigraphy and neotectonics in honour of francesco carraro m. gabriella forno 1-2 1 dipartimento di scienze della terra, università di torino, torino, italy 2 natrisk interdipartimental centre, università di torino, grugliasco, italy corresponding author: m.g. forno <gabriella.forno@unito.it> abstract: two field trips that followed the 2015 aiqua congress (torino, february 24-26) focused on the type-area of the villafranchian succession” and on the ivrea morainic amphitheatre are reported. keywords: quaternary, aiqua congress, fieldtrip, villafranca d’asti , ivrea morainic amphitheatre, italy available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 28 (1), 2015, vii x fig. 2 some conveners and attendees observe the deltaic front sand (ferrere unit) of the ronco outcrop (stop 1) (photo by f. gianotti) fig. 1 shaded relief of the villafranca d’asti area and location of the field trip stops (villafranca d’asti, in the central sector of the type-area) (stop 2). these sediments (san martino unit) are cut by the cascina viarengo erosional surface and covered by fluvial gravel sand (cascina gherba unit). this erosional surface represents an important stratigraphic discontinuity between the lower complex (piacenzian) and the upper complex (calabrian). the thin organic paleosols, rich in organic matter and continental molluscs, were also observed in the outcrop. the subsequent stop was located at cascina gianotti (villafranca d’asti) (stop 3), where the sedimentologic features of the fluvial clayey silt forming the upper body of the “villafranchian succession” (maretto unit), strongly weathered, has been observed. the convivial lunch took place in the large terrace of the taverna di san michele, at dusino-san michele, overlooking the morphological scarp observed in the afternoon. the morphology along the t. traversola deformation zone was observed at dusino (dusino-san michele in the western edge of the type-area) (stop 4). the high scarp located along this structure, separating the poirino plateau from the asti reliefs, resulted particularly evident during the trip because favored by the high brightness of the beautiful day . the geological evolution along the structure has been fruitfully discussed during the route. the deformation zone was reported as involved by erosional phenomena developed by the ancient trend of the po river, responsible of the shaping of the type-area during the middle-upper pleistocene. near the villata village (valfenera, in the sw corner of the type-area) (stop 5) the differences in the “villafranchian succession” along the deformation zone were observed. these differences have also been re viii forno m.g. et al. fig. 3 the researchers in the front of the deltaic plain silt outcrop of cascina san martino (stop 2) (photo martini) fig. 4 the attentive audience (stop 4), in the sector along the t. traversola deformation zone (photo gianotti) fig. 5 the researches observe the evidence of the t. traversola deformation zone (stop 4). in the foreground the snowy scenery of the western alps (photo gianotti) ported by electric tomographies. indeed along this structure very fractured sediments were also observed, that are linked to the transcurrent movement typical of this deformation zone. finally, near cascina volpiano (valfenera, in the sw corner of the type-area) (stop 6) numerous close fractures developed along the deformation zone were observed. the paleosol that is preserved at the top of the lower complex of the “villafranchian succession” was also evident. the organizers would like to express their sincere thanks to the participants for the attention to the different topics and for the suggestions, that may be useful to develop further research on the type-area. ivrea morainic amphitheatre the second excursion took place on thursday, 26th february in the ivrea morainic amphitheatre (ima) at the aosta valley outlet, about 30 km nne of turin, favored by a still sunny day. franco gianotti led the 22 attendees to the different sectors of the big end moraine system (fig. 6), previously defined by penck et al. (1894) as the most significant one in the alpine region. the spillway of mazzé was the first stop (stop 1); there the subglacial melt-out till of the ima frontal moraines outcrops. these deposits are well exposed in the deep incision of the dora baltea river through the amphitheatre. they have a particularly fine grain size and homogeneous lithofacies and color; furthermore they contain reworked pliocene marine-mollusc fossils. then rhe filed trip moved to the san martino canavese village, which is at the inner edge of the ima western sector, to ascend the rio rudo fluvial incision (stop 2). there three sequences of glacigenic deposits spectacularly crop out; they consist of melt-out and lodgement till affected by subglacial deformation,, and of glaciolacustrine fan-delta gravels and sands. deposits are separated by paleosols and affected by thrusts induced by subglacial tectonic. a pair of panoramic stops have allowed us to view the internal depression of the amphitheatre (near the stop 2) and the serra d'ivrea giant lateral moraine, bordering the inner edge of the ima eastern sector (stop 3). the lunch break was in the restaurant "della serra" in broglina (stop 4), placed in correspondence to a major stratigraphic boundary. the site lies in an outwash valley between two moraines of the serra group formed during glaciations referable to the mis 6 and mis 2 stages respectively. finally the entire ima eastern (left) valley side, in the biella region was crossed; there the oldest ima moraines, referred to the end of the early pleistocene are preserved. lastly the group reached the last stop at the roman gold mines named the bessa aurifodine, a very important site of geo-archaeological interest (stop 5). in this area the river erosion demolished all the local moraines and formed an outwash plain constituting a gold placer. in the ii-i century bc, under the republic of rome, mine exploitation produced impressive mine dumps, extended over about 10 km2, made of endless accumulations of rounded cobbles, that lie on the top of a high fluvial terrace (fig. 7), and of big anthropic alluvial fans all around the terrace. fig. 7 the bessa aurifodine, a very important site of geoarchaeological interest (stop 5) (photo by gianotti) fig. 6 – shaded relief of the ivrea morainic amphitheatre and location of the field trip stops ms. received: may 12, 2015 final text received: may 26, 2015 ix the plio-pleistocene continental record ... fieldtrips amq 24 giraudi impaginato 04082014 available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 27 (1), 2014, 5 28 quaternary studies as a tool to validate seismic hazard potential of tectonic structures: the case of the monferrato thrust front (vercelli plain, nw italy) carlo giraudi enea c.r. saluggia, vercelli, italy corresponding author: c. giraudi <carlo.giraudi@enea.it> abstract: this paper proposes the study of the quaternary geological evolution of the vercelli plain (piedmont, nw italy) with the aim of validating the reliability of assumptions about seismic hazard of tectonic structures based on seismotectonic data obtained from studies at regional scale. in particular, the quaternary evolution is interpreted in order to verify and date the tectonic activity of the monferrato thrust front, i.e., the westernmost arch of the buried northern apennines front. in reference to the main purpose of the work, it is observed that only some stretches of the buried front (lucedio and cavourrina fault and, very likely, the flexures of crescentino and morano po) were active between 870 and 400 ka bp. after 400 ka bp, near crescentino and trino, some structures transversal to the monferrato front were probably activated, inducing the uplift of n-s elongated areas. the uplift affected both the northern monferrato slope and the areas of the plain located south and north of the thrust front. the uplifted trino area was limited to the east by the salera line. there are no indications of structures (fault or flexure) to the west of the trino area or which form the limits of the uplifted crescentino area, although their presence could be hypothesized. the salera line is the most important identified structure; it is very likely a complex-kinematics fault that was active from the pliocene to the upper pleistocene and the holocene. it continues to the south inside the hill areas, for a length of about 20 km. therefore, the recent tectonic movements are not associated with the monferrato thrust front, as claimed by other authors, but rather with n-s structures which are transversal to the front. although elements to evaluate the seismic hazard possibly associated with these structures are not available, it is unlikely that the seismicity alone of the easternmost apennine fronts (emilia and ferrara folds) can provide useful information to assess the seismic hazard of the vercelli plain and of northern monferrato. keywords: quaternary evolution, buried tectonic structures, climatic impact, climate and tectonic interaction, river diversions, vercelli plain, monferrato hills. 1. introduction a detailed study of the quaternary evolution of the vercelli plain (northwestern italy) is used here as a tool to assess the reliability of previous assumptions based on seismic hazard which were generally based on the analysis of historical seismicity, on the evolution of the drainage network, on the presence of quaternary sediments displaced by faults, and on gps measurements. data collected and presented in this paper are interpreted in order to verify and date the tectonic activity of the buried thrust front of this sector of the apennines. as quaternary sediments of the vercelli plain bury the monferrato thrust front (i.e., the westernmost of the three major buried arches of the northern apennines; fig. 1a) the detailed geological and geomorphological study of the plain provides a reliable tool for understanding the possible activity of the front. in fact, according to several authors (e.g. costa, 2003; dela pierre et al. 2003b; galadini et al., 2012) the activity of the frontal thrust of monferrato ended in the early pleistocene while, further to the east, the emilian and ferrara fronts are still active. this is testified also by historical and instrumental seismicity, which is totally absent in the monferrato front, and increases toward the emilian folds (galli, 2005), reaching a maximum in the ferrara folds (galli et al., 2012; burrato et al., 2012a). on the other hand, the results of other seismotectonic research, conducted at the scale of the whole po valley, led to the hypothesis that the monferrato front may be seismically active, even if characterized by earthquakes with long return periods. both bonadeo et al. (2010) and michetti et al. (2012), suggest that the level of seismic activity of the monferrato front could be similar to the two other northern apennine fronts. indeed, according to michetti et al. (2012), the monferrato front might be able to generate earthquakes of mw 6. in the past, the presence of the trino isolated ridge (known as rit in the literature), lying above the buried monferrato front, had already stimulated research by the working group on the po valley quaternary (gruppo di studio del quaternario padano: gsqp, 1976) which established that the area could have been affected by middle pleistocene tectonic activity. moreover, geodetic data reported in arca & beretta (1985) provide information on some aseismic deformations that occurred along a section which crosses the se portion of the area of this study during the period between 1897 and 1957. thus, the conflicting interpretation of tectonic activity and seismic hazard, and the presence of aseismic deformations, require detailed study of the quaternary geological evolution to determine which deformations were recorded by sediments and landforms, and thus which structures are likely to be active. in this paper, the evaluation of the deformation of quaternary sediments, including those dated as the last 2-3 ka, suggests the activity of tectonic structures which only partially match those hypothesized in the literature. to assess adequately the tectonic evolution of this area, this study takes into account the interaction between sedimentary and erosive phases driven by climate and those probably influenced by tectonics, starting from the upper lower pleistocene. 2. study area the vercelli plain lies between the river dora baltea and the ivrea morainic amphitheatre to the west, the river po and the monferrato hills to the south, the river sesia to the east and the rivers elvo and cervo to the north (fig. 2a). the plain is mainly formed by plio-pleistocene sediments, but in its southern part a thin quaternary sedimentary cover lies on marine sediments. the tertiary marine sediments, outcropping in the po riverbed, are folded and heavily deformed by the activity of the northernmost monferrato thrust front (sgd’i, 1969a; dela pierre et al., 2003a). a large part of the vercelli plain is in the sesia river catchment whereas only the western and southern portions of the plain are in the catchments of the rivers dora baltea and po (fig. 2b). it should be noted than the po catchment, which includes a large area of the western alps and the northern slope of the torino and monferrato hills, before receiving the stura di monferrato stream, narrows to 1.5-2.5 km (fig. 2b). in the monferrato hills the divide of the small catchments that drain toward the po migrates abruptly towards the north and remains very close to the plain down to the confluence with the stura stream. starting from the area of gabiano, the bed of the po is always very close to the hill slope and erodes it. the narrowing of the po catchment in the southern vercelli plain and in the northern monferrato slope is an apparent anomaly compared to the westernmost areas. the po, which is the main watercourse in the study area, during the quaternary was mostly flowing south of the monferrato hills. it migrated north of the hills only after a diversion that took place during the late pleistocene (carraro, 1976; carraro et al.,1980; 1995). before the diversion, the rivers sesia and dora baltea flowed into a river, which from now on will be referred to as the dros, formed by the confluence of the rivers dora riparia, orco, stura and other smaller streams, whose basin was in the north-western part of the alps. 3. methods in this paper a detailed discussion of the topographical, geomorphological and geological elements is presented in order to assess the chronology of the tectonic phases and to verify whether the most recent tectonic activity is actually connected with the monferrato thrust front or with other structures. topographic observations are based on the trend of the contour lines reported (ajassa et al., 1990) on the elevation map of the piedmont plain (carta altimetrica dell'alta pianura giraudi c. 6 fig. 1 apennine thrust fronts buried below the quaternary sediments of the po plain, and main structures of the monferrato thrust front. 1a: general view of the apennine buried fronts. 1b: the monferrato-torino hills thrust front according to costa (2003). 1c: the monferrato thrust fronts below the quaternary sediments of the vercelli plain, according to the geological map of italy f. vercelli (1969) and enel (1985). 1d: the monferrato thrust fronts below the quaternary sediments of the vercelli plain according to (msdi = bigi et al., 1990) and (cgt = dela pierre et al., 2003a). 7 quaternary studies as a tool to validate assumptions about seismic hazard ... piemontese in italian) at the scale of 1:250,000. the data used to draw the topographical profiles are reported on the carta tecnica della regione piemonte (the official regional topographic cartography) at a scale of 1:10,000. the profiles were designed using 5 m contour lines. the geological maps presented are the result of both field surveys carried out over a long period of time, and of the interpretation of aerial photographs. the flight done in the '50s (istituto geografico militare, flight) was mainly used, as it is the most useful one for the recognition of low terrace scarps. as a matter of fact, agricultural works carried out in the second half of the past century often erased morphological features that, in turn, could be relevant for the interpretation of the evolution of the area. the lithology of the sediment forming the surface of the terraces has been observed on terrace scarps, along the banks of streams and on ephemeral exposures. field data have been integrated with stratigraphic data from boreholes. in the area west of ronsecco and nw of the rit, the stratigraphy of the sediments was surveyed along several 2.5-m-deep, and 100-m-spaced trenches, all dug for the foundation of high voltage pylons, and arranged along two different alignments, for a total length of 7-8 km. fig. 2 location of the studied area. 2a: contour map, slope of the plain, topographic anomalies and main geological structures buried below quaternary sediments. 2b: the river po catchment basin west of the confluence of the stura stream. the chronological framework was mainly based on the morphological correlation between the terraces in the vercelli plain and the glacial and glaciofluvial features of the ivrea moraine amphitheatre (gianotti et al., 2008). the age of some sediments has been constrained by previous geochemical characterization of a tephra layer (enel, 1984), by the dating of a second tephra layer with the fission track method (enel, 1984), by some radiocarbon dating (tropeano & olive, 1989; giraudi, 1998) and by the presence of archaeological artefacts from the lower palaeolithic to the bronze age (fedele, 1976; gsqp, 1976; giraudi, 1998). i have assessed the stratigraphy of the quaternary deposits through both the stratigraphy of water wells (varalda et al., 2006; arpa piemonte, 2014), and direct observation of boreholes drilled in the framework of a study for the seismotectonic characterization of areas identified as possible locations of nuclear power plants, in the years between 1976 and 1984 (enel, 1984). the enel data have already been used for the geological map of italy at a scale of 1:50,000 (dela pierre et al., 2003a) and the stratigraphies of the boreholes carried out by enel are listed and described in the geotechnical data bank of the arpa piemonte (2014). in order to infer the quaternary tectonic deformations, thickness changes of alluvial and glaciofluvial sedimentary units and different elevations of the base of sediments forming the terraces have been evaluated. indeed, the stratigraphic data show a great thickness variability of glaciofluvial and alluvial sediments forming the plain north and south of the monferrato buried thrust front. 4. geology of the vercelli plain the vercelli plain is composed, almost completely, by glaciofluvial, fluvial and aeolian quaternary sediments (sgd’i, 1969a). marine tertiary sediments outcrop on the scarps of the highest terraces and in the bed of the river po, i.e. where the river is eroding the northern slope of the monferrato hills. as already mentioned, the southernmost portion of the plain is formed by quaternary sediments, less than 15-20 m thick, lying on the tertiary bedrock deformed by folds, fault and involved by the frontal thrust. the following description of tertiary sediments and tectonic structures is based on data derived from geophysical researches and wells dug during oil exploration campaigns (pieri & groppi, 1981; cassano et al., 1986) and the seismotectonic characterization of sites suitable for a nuclear power plant (enel, 1984). lastly, data from the po river bed derive from a survey of the outcrops. 4.1. tertiary bedrock and main tectonic structures previous works on the study area have stated the bedrock of the southern vercelli plain is formed by tertiary marine sediments involved in one or more thrust fronts. tectonic interpretations (fig. 1c; 1d) reported in sgd’i (1969a), enel (1984) and in bigi et al. (1990) show that the northernmost thrust front (balzola fault) affects at depth the lower pliocene marine sediments. south of the balzola fault, one or more thrust fronts are reported by the authors. according to costa (2003), the northernmost part of the monferrato thrust front has been extruded northwards along two lateral structures (fig. 1b) located east and west of the front. borehole data (enel, 1984) aided in recognizing 8 fig. 3 position of the boreholes and the wells, tertiary and early pleistocene sediments lying below late early pleistocene to holocene deposits. 3a: boreholes and wells used for their stratigraphic data. 3b: age of the sediments sampled in the boreholes covered by glaciofluvial and fluvial deposits, and outcropping in the po river bed, main tectonic structures inferred from the borehole stratigraphy. giraudi c. the presence of marine sediments below the quaternary glaciofluvial and fluvial sediments, mainly dated from eocene to pliocene, but also to the onset of the early pleistocene, and of early pleistocene alluvial and lacustrine sediments (fig. 3a, b). in this paper the upper pliocene marine sediments reported in enel (1984) are dated at the early pleistocene of the new international geochronological scale (gibbard et al., 2010). except for some areas (oligocene, pliocene and early pleistocene marine sediments outcropping or drilled in the rit area and south of crescentino) the boundaries between the different marine formations cannot be clearly traced. it follows that in fig. 3 the sediments and their ages are shown with symbols in correspondence to the places where they have been recognized. through borehole alignments (enel, 1984) it was possible to deduce the presence of at least two faults (cavourrina and lucedio faults fig. 3a), the position of which lies within a 40-50-m-width strip matching the distance between the closest pair of boreholes. the cavourrina fault juxtaposes oligocene and pliocene marine sediments (fig. 3b). the fault bounds the northern edge of the rit and it was very likely responsible for its uplift. west of the rit, the fault plane dips to the nw. north of the rit, according to the drilling stratigraphy, the fault plane is nearly vertical. southeast of the rit, the fault reaches at least the latitude of trino (fig. 3), where two closely spaced drillings show the presence of marls, probably oligocene (in the west) and of pliocene silty sands (in the east). there are no data that can be used to infer whether the fault continues to the south, outside of the area surveyed with boreholes. the lucedio fault trends wsw-ene, being slightly convex northward. here pliocene and lower pleistocene marine sediments are faulted against lower pleistocene fluvial and lacustrine sediments, inducing the subsidence of the northern area at least after the lower pleistocene. in the alignment where the boreholes are closer, the northward dip of the fault plane cannot be less than 80°. hydrogeological studies in the area (enel 1984) have shown that, just to the north of the lucedio fault, there are springs fed by water rising from deep aquifers (fig. 3) having a chemical and isotopic composition very different from that of water of surrounding areas. the rise of deep water also occurs nw and se of the stretch of the fault indicated by an alignment of boreholes: it is therefore probable, as suggested in enel (1984), that the lucedio fault might reach the areas north-east of crescentino and of salera, south-east of tricerro. a seismic line crossing the faults north of the rit (enel, 1984) shows that both the cavourrina and lucedio faults match the thrust fronts evidenced by the sgd’i (1969a) (fig. 1). here the cavourrina fault could partly fit in with the youngest thrust front reported by bigi et al. (1990). on the other hand, ese and wsw of crescentino, where many authors placed the monferrato thrust front (sgd’i, 1969a; pieri & groppi, 1981; enel, 1984; cassano et al., 1985; dela pierre et al., 2003), at least down to the depth of about 200 m, any of the available borehole logs account for the existence of faults similar to the lucedio one. the pliocene and lower pleistocene marine sediments dip 10-15° to the nnw and are deformed by a flexure. the flexure starts just east of crescentino near the western termination of the lucedio fault. the change of the tectonic features of the thrust front east of crescentino implies the presence of a fault crossing the front (crescentino fault) which could match the nw-se lateral ramp hypothesized by costa (2003). indeed, the crescentino fault (fig. 3b) reaches the po river bed in a place where outcropping tertiary marine sediments show nw-se fault planes. in the area between pontestura and morano po, the river bed is almost completely carved in tertiary bedrock (fig. 3b): the presence of calcareous marl suggests that it belongs to the eocene terms of the “ligurian” units, the same reported by dela pierre et al. (2003a) in the po bed south of trino. in the river bed ne of pontestura, nearly vertical marl strata, running n-s, outcrop, while to the east strata dip very irregularly and are displaced by faults. undeformed nnw-sse marl outcrop in the river bed sw of morano po, that is, east of the area where the sediments are displaced by faults. also near casale monferrato, in the river bed, eocene clay and calcareous marl of the “ligurian” units outcrop, although a few dozen metres north of the river bed, pliocene marine sediments (subzone mp14 and mp15a) have been found in boreholes (violanti & sassone, 2008). the boundary between eocene and pliocene sediments is not exposed, but strongly deformed outcropping sediments suggest the presence of an unconformity or a tectonic contact. the geological structure of the casale monferrato area matches that of the castel verrua area, south of crescentino, where pliocene sediments unconformably overlie the deposits of the “complesso indifferenziato” (“ligurian” units; zappi, 1961; dela pierre et al., 2003a,b). at casale monferrato, the contact could correspond to the projection at the surface (fig. 1c) of a nwse thrust front (evidenced in enel, 1984) or of another front (fig. 1d) hypothesized in bigi et al. (1990). 4.2. geomorphology and quaternary stratigraphy of the vercelli plain the vercelli plain is quite homogeneous, especially in the north-western and central-northern areas (fig. 2a). according to all previous works (sgd’i, 1966; sgd’i, 1969a; gsqp, 1976; carraro et al., 1975; giraudi, 1998; dela pierre et al., 2003a; gianotti et al. 2008) it is mainly formed by glaciofluvial and fluvial sediments dated between the mindel glaciation and the holocene. despite the scarcity of exposures, the stratigraphy of the sediments is fairly well known thanks to boreholes drilled for water and stratigraphic surveys. the stratigraphic data enable the thickness of the quaternary sediments to be evaluated and also to differentiate the areas in which sedimentation prevailed from others where erosion and sedimentation phases occurred. based on the abundance of terraces formed by the main streams, (fig. 4) the vercelli plain can be divided 9 quaternary studies as a tool to validate assumptions about seismic hazard ... into four parts: the north-western area, formed by some terraced surfaces, is a narrow strip surrounding the hills of the se ivrea morainic amphitheatre. the centralnorthern area, extending over about two-thirds of the studied plain, forms the main surface of the plain. the southern area is formed by seven different terraces while the last well recognizable area is the belt formed by three terraces parallel to the river beds. the four older terraces (s1 to s4) are only in the southern area, while the others (s5 to s8 and t9 to t11) are more diffuse. the stratigraphy of the sediments forming the terraces will be described from the oldest to the most recent. however, some parts of the vercelli plain are formed by terraces shaped by local streams (l1-2), and will be described separately. the relationship between sediments that form terraces and moraines of the ivrea amphitheatre indicates the glaciofluvial origin of sediments and suggests the age of some terraces. the bottom of sediments forming the oldest terrace is carved into the tertiary bedrock, while the bottom of other glaciofluvial deposits cuts into older sediments and sometimes into the tertiary bedrock. as determined in the whole of the mediterranean basin by macklin et al. (2002), i have assumed that, if the phases of coarse sedimentation predominantly correspond to periods of glacial expansion, the phases of prevailing erosion mainly correspond to interstadials or interglacials. the terraces (fig. 4), due to their characteristics, can be divided into groups. one group (s1-s3) includes only the terraces that form the rit, relating to a landscape that was significantly different to the modern one. conversely, the distribution of younger terraces (s4-t11), the inclination of their surfaces, and the direction of their scarps enable the identification of their own stream. in this group of terraces a first subgroup (s4-s8) can be distinguished: this includes terraces shaped by rivers that flowed, at least in certain parts, in areas away from the current river beds. the terraces form the eastern portion of the river dora baltea glaciofluvial fan, and the area, oriented approximately w-e, between the rit and the monferrato hills. a second subgroup includes terraces (t9-t11) lying along the modern river beds. several exposures and the stratigraphy and lithology 10 giraudi c. fig. 4 the terraces of the vercelli plain. s1-s3: terraces forming the trino isolated hill (rit). s4-s8: terraces shaped by alpine rivers when their bed was far from the modern ones. t9-t11: terraces forming a belt near the modern day alpine river beds. l1-l2: terraces shaped by local streams. of sediments obtained from boreholes show that some terrace surfaces are formed by sediments of different ages. terrace s1 sediments that form terrace s1 (“a” in fig. 5) are described in sgd’i (1969a), gsqp (1976) and enel (1984) as directly overlying the oligocene marine bedrock, 8-9 m thick, and formed, at the bottom, by glaciofluvial sandy gravel. sediments are very weathered (colour 2.5-5 yr of the munsell soil color chart, mscc). the degree of weathering of sediments is also similar to that of deposits partly outcropping on a terrace scarp eroded by the dora baltea river (“a” in fig. 5), not far from the morainic front, and assumed to be formed before the mindel glaciation (sgd’i., 1969a). a layer of pedogenized loess (coloured 5yr, mscc) lays above sandy gravel, and it is covered by a younger, pedogenized loess (coloured 7.5yr, mscc). according to the sgd’i (1969a), the older loess sedimented during the mindel glaciation, while the second one is dated at the riss glaciation. another thin and discontinuous loess horizon, (pedogenized and coloured 10yr, mscc), ends the stratigraphic sequence. the s1 glaciofluvial sediments are weathered and pedogenized to the same degree as some morainic deposits in the northern ivrea amphitheatre reported by gianotti et al. (2008). according to carraro et al. (1991) the moraines with soils coloured 2.5yr (mscc) are the oldest and, according to their palaeomagnetic characteristics, can be dated to the late early pleistocene. other 11 fig. 5 geological map of the vercelli plain. legendm1-m2: moraine ridges of the serra alloformation; a-h: late early pleistocene to late upper pleistocene glaciofluvial sediments; a: late early pleistocene (mis 22-?); b: late early pleistocene to middle pleistocene (mis 22?-mis 12); c: middle pleistocene (mis 10); d: middle pleistocene (mis 8); e: late middle pleistocene (mis 6); f: late middle pleistocene or early upper pleistocene; g: early (?) and middle upper pleistocene (mis 4?); h: late upper pleistocene (mis 2); i, l, m: late holocene. l1: sediments from valdora temporary stream and other local streams (mis 4? mis 2?); l2: sediments of the local streams (mis 2?late holocene). quaternary studies as a tool to validate assumptions about seismic hazard ... moraines, early middle pleistocene in age (gianotti et al., 2008), contain soils coloured 5yr (mscc). the s1 glaciofluvial sediments, being the oldest and most weathered, could have the same age as the oldest moraines and date back to late early pleistocene. the loess dating is based mainly on the presence of prehistoric artefacts. the younger loess covers some upper palaeolithic artefacts and can be dated at the mis 2. the intermediate loess covers lower palaeolithic artefacts and includes at the top some middle palaeolithic mousterian artefacts. thus, the top of the loess may be dated to the late middle pleistocene or upper pleistocene (fedele, 1976), that is, at mis 6 mis 3. the older loess is, therefore, older than mis 6 and dated at least at mis 8. terrace s2 the terrace surface s2 is separated from that of s1 by a scarp that reaches a height of approximately 10 m. the stratigraphy of the sediments forming the terrace ( sgd’i, 1969a; gsqp, 1976; enel, 1984), is very similar to that of s1. glaciofluvial sandy gravel and very weathered sand (coloured 2.5-5yr, mscc), (“b” in fig. 5) form the main sedimentary body. the s2 sediments, assumed to be older than the mindel glaciation by sgd’i (1969a), can be correlated to the moraines having the same degree of weathering and can be dated to the late early pleistocene or the early middle pleistocene. they are covered by two loess horizons, the older and more weathered one (colour 5yr) being covered by a less weathered one (colour 7.5yr). at the top of the younger loess, middle palaeolithic mousterian artifacts have been found (fedele, 1976). we can assume, therefore, that the loess horizons correspond to those described for the s1 surface and that they are of the same age (mis 6mis 3 and mis 8). on the whole, the sediments are 15-16 m thick. terrace s3 terrace surface s3 is separated from that of s2 through a scarp that reaches a height of approximately 10 m. the stratigraphy sediments (gsqp, 1976; enel, 1984), is made by gravelly sand and sandy gravel, with interbedded sand and silty sand layers, weathered at their top and coloured 5yr (mscc). also these sediments are originally glaciofluvial, but interbedded fine sediments are colluvia that originated from the s2 terrace scarp. the glaciofluvial sediments can be correlated to moraines having the same degree of weathering and, consequently, dated to the early middle pleistocene. as on terrace s2, the pedogenized glaciofluvial sediments are capped by two loess horizons: the older one is more weathered (5yr in colour) than the younger one (7.5yr). the loess horizons can be correlated, therefore, to those lying on terraces s1 and s2. on the whole, the thickness of sediments forming the terrace s3 can be around 15-17 m. terrace s4 the terrace s4 has been observed in three places, north of the rit and north of crescentino. here the s4 surface is preserved in two small, isolated flattened heights which are surrounded by younger terraces. the first, larger one (nearly divided into two parts by a small valley with a flat bottom) lies near san grisante, while the second one is near lamporo. sediments forming the san grisante terrace (gsqp, 1976; enel, 1984), are glaciofluvial sandy gravel covered by silt and sandy silt. glaciofluvial sediments (“b” in fig. 5) are very weathered and there is a truncated palaeosoil at their top. therefore, between the end of the glaciofluvial sedimentation and the onset of the deposition of top silts, a strong pedogenetic phase occurred which was followed by an erosion. the degree of weathering of san grisante glaciofluvial sediments is similar to that of sediments forming terraces s2 and s3 and of moraines dating back, according to carraro et al. (1991) and gianotti et al. (2008), to the late early pleistocene or the early middle pleistocene. according to gsqp (1976) the soil on the top of the glaciofluvial sediments is the socalled “ferretto”, which developed during the interglacial between the mindel and the riss glaciations, that is during the mis 11. the glaciofluvial sandy gravel should therefore have been sedimented during the mis 12 or earlier. silt and sandy silt sediments, overlying the top of glaciofluvial sandy gravel, form a layer of variable thickness (from 3.6 to 6 m) and are capped by a soil coloured 10yr/7.5yr (“d” in fig. 5). silt is similar to that forming the top of the torrazza-rondissone terrace, lying w of the dora baltea river, described by gsqp (1976). silt sedimented on a flood plain or in a palustrine basin, but at its top it consists of loess-derived deposits. in the torrazza-rondissone terrace, interbedded between the silty deposits, some 0.1-0.5-m-sized polished and striated pebbles form some stone-lines. according to gsqp (1976) pebbles could have been carried there by floating ice chunks stemming from the tongue of the dora baltea glacier. the sin-glacial origin of sediments assumed by sgd’i (1969a) is therefore confirmed. in a quarry of the torrazza-rondissone terrace, interbedded in the upper silt sediments, a horizon containing volcanic glass was sampled. mineralogical characteristics of glass suggest that it originated from the m. amiata volcano (enel, 1984), which was active between 300 and 180 ka bp (bigazzi et al., 1981), that is, in a period including the mis 8 and the early mis 6. north of the rit, top sediments forming the surface are made by 4-to-6-m thick silt, very similar in its lithology and sedimentary facies to that described above and containing remnants of the tephra layer. silt covers unweathered sandy gravel (“d” in fig. 5), about 8 m thick. below the sandy gravel, a colluvium of a soil formed by very weathered silty clay coloured 2.5yr, was sampled in a borehole. it follows that the colluvium derives from the top of the pedogenized sandy gravel forming s1, and that the sandy gravel was probably sedimented during the same cold stage just before the silt. as the top of terrace s4 is higher than the s5 (dated at the mis 6; see below), it was formed in a cold stage preceding the mis 6. based on the volcanic glass chronological framework, the cold stage is, therefore, the mis 8 (280240 ka bp). the loess-derived palustrine sediments could therefore be correlated with the oldest loess, which overlies soils coloured 2.5-5yr, identified on terraces s1, s2 and s3. terrace s5 this forms the nw part of the vercelli plain and derives from the melting of remnants of different terrace surfaces that can be distinguished only near the moraine hills. the terraces consist of glaciofluvial sediments weathered by a soil coloured 7.5yr. they outcrop dis 12 giraudi c. continuously and, generally, are limited in extent, forming an apron around the moraines. in turn, the moraines lying at the nw boundary of the study area are formed by two differently preserved series of ridges (m1 and m2 in fig. 5). the presence of a series of terraces and moraine ridges shows that the evolution of the glacial front in this area was very complex. according to gianotti et al. (2008), both moraines and glaciofluvial sediments, dated to the riss glaciation in former geological maps and papers (sgd’i, 1966; 1969a; carraro et al., 1975), pertain to the “serra alloformation” dated to the late middle pleistocene, that is, the mis 6. to the south and se the different surfaces join to form a single surface (s5, fig. 4). above the contour line 170 m a.s.l. (fig. 5), surface s5 is formed mainly by sandy gravel sediments, sometimes covered by a thin silt layer, weathered by a soil coloured 7.5yr. at a lower altitude, surface s5 develops on sediments having different ages and origins. in the area ne of lamporo, glaciofluvial sandy gravel, heavily weathered (coloured 2.5-5yr) down to a depth of 10-12 m (“b” in fig. 5), is both exposed and sampled in some boreholes; this is very similar to that underlying the silt that forms the s4 surface near san grisante. the degree of weathering of sediments is similar to that of s2 and s3 terraces and of the moraines dating back to the late early pleistocene or the early middle pleistocene (carraro et al., 1991; gianotti et al., 2008). in the area ne of lamporo, pedogenesis lasted for a longer period than in the san grisante and rit area, and has continued till the present day. arduino et al. (1984), studying the relationships between the age of soils, the presence of iron oxides and the redness of soils, evidenced that the pedogenesis did not stop during cold periods. other boreholes showed that at the northern and eastern boundaries of the area with strongly weathered sandy gravel, there are sandy gravelly sediments a few metres thick, less weathered and coloured 7.5yr (“c” in fig. 5). these sediments are covered by the younger glaciofluvial sediments that were described above, dated to the mis 6. in some places surface s5 is capped by discontinuous layers of silt, 2-3 m thick, alluvial in origin, formed by the sedimentation of material derived from the erosion of soils developed on glaciofluvial deposits. the silt can be both stiff and weathered by a soil coloured 7.5yr, or less stiff, but less pedogenized (soil coloured 10yr). the latter sometimes overlaps the more weathered one. in profiles 1 and 2 (fig. 6) it can be noted that the boundaries between the different sedimentary units described above are evidenced by small changes in the slope of the plain: the places where the most weathered sediments are exposed are the flattest. terrace s6 this terrace is only in the western plain (fig. 4). a scarp 3-4 m high separates it from s5 but it becomes less clear and nearly disappears towards the se. the terrace is made by sandy gravel (“f” in fig. 5), the thickness of which is unknown, younger than the mis 6 glaciofluvial sediments forming s5. terrace s7 the surface of terrace s7, surrounding both the rit and the s4 terraces, is well represented in the area. the scarp that separates the terrace from s6 is higher to the west and becomes smaller towards the east, and the boundary between surfaces s7 and s5 is not a real scarp, but only a slight break in the slope of the plain (profiles e, f, in fig. 6). west of the lamporo area, sediments forming the terrace (“g” in fig. 5) are mainly glaciofluvial sandy gravel, while to the east, in places where the surface is less eroded by local streams, a layer of alluvial silt, 2-3 m thick, pedogenized by a soil coloured 7.5yr, covers the sandy gravel. in a few places, the top silt is capped by another layer of silt not so stiff, with a less evoluted soil coloured 10yr, which can be correlated to the younger silt layer lying on terrace s5. the sediment thickness is on the whole about 15 m. near the sw slope of the rit, below the silt that forms surface s7, sandy gravel weathered by a soil coloured 5yr has been found. these sediments are probably remnants of the sandy gravel forming also terrace s3, only eroded at the top during the shaping of terrace s7. the terrace correlates with that evidenced by gianotti et al. (2008), outside the moraine amphitheatre, on the right of the dora baltea river, and formed by glaciofluvial deposits of the piverone alloformation. the terrace sediments, therefore, can be dated to the period following the mis 6 glacial maximum (which ended about 140 ka bp) and preceding the mis 2 glacial maximum (which started about 30 ka bp), named mis 4? in this paper. surface s7 was eroded by local streams. west of the rit, these streams caused mainly the erosion of the summit silt, while north and ne of the rit, the terrace is cut by a complex network of small valleys, the bottom of which lies between 1-2 m and 7-8 m below the terrace surface. terrace s8 the scarp dividing s7 from s8 is lower towards the west and higher towards the east: it is this feature that makes it different from those that separate the terraces s5 from s6, and s6 from s7. in the plain south of the po river, terrace s8 has been observed only west of castel verrua and east of casale monferrato, but is lacking in the intermediate area. sediments forming the terrace (“h” in fig. 5) mainly consist of sandy gravel, overlain by a soil coloured 10yr. the sediment thickness, which is known only in the trino and palazzolo area, does not exceed 10 m. the terrace correlates with that evidenced by gianotti et al. (2008), outside the moraine amphitheatre, on the right of the river dora baltea, and is formed by glaciofluvial deposits of the ivrea alloformation. inside the amphitheatre sediments of the ivrea alloformation are dated to the last glacial maximum, around 21 ka bp, according to gianotti et al. (2008), or are younger, because they also lie upstream of the terminal moraines. the sediments forming s8 can be dated, therefore, to the late upper pleistocene, between 21 and 14-15 ka bp. terraces t9, t10, t11 these are the most recent terraces and form a discontinuous strip along the river beds. it should be noted that starting from the area south of fontanetto po down to trino, the strip formed by terraces t9, t10 and t11 is narrower than in the 13 quaternary studies as a tool to validate assumptions about seismic hazard ... western and eastern areas (1.2 to 2.5 km wide, against the 2.5-5 km near crescentino and 3-3.5 km east of morano po). in the plain south of the po, between verrua savoia and casale monferrato, only terrace t11 is present. alluvial sediments forming terraces t9, t10 and t11 are mainly of sandy gravel lithology (i, l, m in fig. 5). their thickness, visible only between fontanetto po and trino, does not exceed 6-8 m. in the sediments that form terrace t9 some useful dating elements have been found. in a borehole drilled near fontanetto po an iron nail contained in the sandy gravel came to light, similar to those used by romans for the ivrea harbour in the dora baltea river (f. gambari, personal communication). in a quarry south of villanova monferrato, tree trunk remnants have been exposed, dated 380-600 ad, 115-725 ad and 440-640 ad (2σ calibrated 14c age; tropeano & olive, 1989). it follows that terrace t9 should be dated to the roman and the early medieval periods. on the po banks, near palazzolo, trino and morano po, where sandy gravel forming terraces t10 and t11 lie directly on the tertiary bedrock, at the bottom of the alluvial sediments, bronze axes and swords from the bronze age have been found (janigro d’aquino,1979; fozzati & giraudi, 1983; facchin, 1997; giraudi, 1998). near the po bed, north of camino, the t11 sediments cover the remains of a medieval building and contain remnants of poles, from the middle ages (1225-1400 and 1325 -1460 ad), and trees, dated to the renaissance (1410-1620 ad) (2σ calibrated 14c age; giraudi, 1998). on the whole we can state that sediments forming the three most recent terraces date back to the last 3-4 millennia. terraces shaped by small local streams the vercelli plain has been shaped also by local streams mainly fed by water from springs sited along the “risorgive” area (de luca et al., 2005). fig. 4 shows two areas shaped in a different way by said streams. surface l1 this is the surface, lower than s5 and s7, that forms the central and northern vercelli plain, formed mainly by sandy gravel. l1 is fairly regular but in the eastern part it appears cut by small valleys with flat bottoms, 1 to 3 m deep, produced by smaller local streams. the scarp between s5 and l1, well recognizable in the nw area, becomes difficult to identify towards the se, but nw of ronsecco it is again well recognizable. in the north-western plain, l1 narrows and enters an abandoned river bed, produced by a glacial meltwater stream, which cut into the mis 6 glaciofluvial sediments. the stream that shaped the l1 surface, therefore, came from the former stream bed (fig. 4), called valdora. according to gianotti et al. (2008) the glacial meltwater stream was linked to the piverone alloformation glacial phase, doubtfully attributed to mis 4, and was therefore contemporaneous with the glaciofluvial sedimentation forming the s7 terrace. however, the surveys carried out for this paper have evidenced that the bottom of the former valdora bed, formed by sandy gravel having a homogeneous grain size and lithology, is cut across by a gently sloping scarp a few metres high. the surface l1 begins east of the scarp, therefore it is younger than the piverone alloformation. in the southern vercelli plain, surface l1 cuts surface s7, which is correlated with said alloformation, confirming that l1 was younger. the scarp, which crosses the former valdora bed, cannot have been produced by lithological discontinuities or tectonic displacements, because these would also have affected the surrounding areas formed by older sediments. it seems reasonable to believe the bottom of the former bed was partly modified by the water of a large spring, which formed near the base of the gently sloping scarp, and was active for a period following the 14 giraudi c. fig. 6 profiles along the vercelli plain. 6a: terrace map with the position of profiles; 1, 2: profiles reported on fig. 6b; a,b,c,d,e,f: position of the profiles reported in fig. 7; 6b: profiles showing the slope of the plain, the boundaries between terraces and stratigraphic units and thickness of glaciofluvial sediments lying on early pleistocene fluvial and lacustrine deposits. 15 piverone alloformation glacial maximum. surface l2 l2 represents a cluster of surfaces shaped by local streams. in fact, the different surfaces are difficult to map because the very low scarps separating them are very difficult to follow and have been partly erased by agricultural works. l2 forms also the bottoms of the small valleys cutting into fluvial terraces and l1 surfaces. the sediments forming l2 are generally silty sand, sand and sandy gravel; their thickness, that reaches 2.5 m, is known only in the trino area because some trenches some hundreds of metres in length have been made for a channel. 4.3 thickness of glaciofluvial sediments according to borehole data the stratigraphy of sediments lying well below the terrace surfaces in the area north of the lucedio and cavourrina faults and the crescentino flexure has been evidenced by boreholes that reached a maximum depth of 200 m (fig. 7). based on the borehole alignments, some geological sections have been drawn, revealing the thickness and the relationships between both the glaciofluvial sediments and the underlying older deposits, as also the presence of possible tectonic structures. three different glaciofluvial and fluvial units (fau) have been identified, mainly formed by sandy gravel overlying, through a sharp contact, thinner fluvial and lacustrine sediments or the older fau deposits. the fluvial and lacustrine sediments are dated at the lower pleistocene, and are mainly made by sand, silt and clay, with vegetation remnants and small pieces of wood interbedded with thin sandy gravel and peat layers (enel, 1984; arpa piemonte, 2014; varalda et al., 2006). the 1st fau includes units “a” and “b” which form the terraces, and overlies lower pleistocene sediments through an erosion surface and has a maximum thickness of about 70 m. the top of the 1st fau is in general eroded and covered by later sediments. when the top of the 1st fau reaches the surface (on terrace s5) or is exposed in quarries (below the silts forming terrace s4 near san grisante) sediments are heavily weathered (soils coloured 2.5yr or 5yr). as discussed above regarding terraces s4 and s5, pedogenesis occurred probably during mis 11 and the top of the glaciofluvial sediments is dated to the mis 12 or is older. based on the age and the weathering, we assume that the 1st fau can be correlated to the strongly weathered glaciofluvial sediments of the rit. however, while on the rit sediments form three different terraces and sedimentary units with a bottom gradually at lower altitudes, north of the lucedio fault the 1st fau formed during conditions of prevailing sedimentation. there are no direct data that can suggest the real age of the base of the 1st fau, but the abrupt increase in sediment grain size at the base of the 1st fau corresponds to the grain size increase that occurred, after the sedimentation of thinner early pleistocene sediments, in the po plain and around the alps. studies carried out by muttoni et al. (2007) demonstrate that at the mouths of the alpine valleys in lombardy (east of the study area), a sharp grain size change occurred during the mis 22 quaternary studies as a tool to validate assumptions about seismic hazard ... fig. 7 stratigraphic sections of the sediments forming the vercelli plain obtained from enel (1984) boreholes. (starting ca. 870 ka bp). moreover, valla et al. (2011) have reported that around 800-900 ka bp, in the french alps, erosion phases stronger than before started. the increased erosion probably produced an increase in the volume and grain size of the debris carried by rivers in the plains surrounding the alps. since the grain size increase is a general trend, and its age agrees with the chronological framework of the 1st fau, we assume that the sharp transition from fluvial -lacustrine to glaciofluvial sediments occurred during the mis 22. the sections reported in fig. 7 show that the 1st fau sediments are not in contact with the lucedio fault. however, the sediment dip changes nearing the fault. in the northernmost area, the 1st fau sediments dip towards the south and se, as one would expect for sediments produced by alpine rivers flowing from north and nw, while near the lucedio fault they dip towards the northern quadrants. the 2nd fau lies on an erosion surface carved in the 1st fau, is mainly of sandy gravel, and reaches a maximum thickness of 20 m. its top is exposed on the s5 terrace surface (“c” in fig. 5) and, as discussed above, is covered by the mis 6 glaciofluvial sediments. the 2nd fau has been identified also in a borehole made near the lucedio fault (fig. 7, section c) embedded between the 1st fau and the glaciofluvial sediments dated mis 6. interbedded within the sandy gravel of the 2nd fau, a tephra layer has been found. its age, obtained by the fission track method, is 350±100 ka bp (enel, 1984). as sediments are of glaciofluvial origin, the tephra fall could be dated to the mis 10 (ca. 380-340 ka bp) or mis 8 (ca. 280-240 ka bp). however, the stratigraphic framework and the tephra age indicate that the tephra was deposited during the mis 10, because the sediments of the 2nd fau are older than the deposits forming terrace s4, dated mis 8. as the 2nd fau is dated at mis 10, the erosion surface that separates it from the 1st fau is probably dated mis 11. the 2nd fau is very near to, or in contact with the lucedio fault plane (fig. 7, section c). however, its deposits are not faulted, but overlie an erosion surface cut into the early pleistocene lacustrine and fluvial sediments which are displaced by the fault. this implies that, during the mis 10, a river was flowing just north of the lucedio fault. the 3rd fau includes all the sediments younger than that forming the 2nd fau. the contact between its base and the older sediments occurs through an erosion surface. the older sediments forming this fau are dated to the mis 8 in terrace t4. on the whole, the stratigraphy of the sediment evidenced by boreholes shows that in the area north of the lucedio fault sedimentation prevailed, while south of the fault erosion and depositional phases alternated. the difference between the northern and southern areas, however, disappeared during the sedimentation of the 3rd fau. 4.4. summary of the stratigraphic data the combination of morphological and stratigraphic data indicates the chronology of sediments that form the vercelli plain. the deposition of the older glaciofluvial sediments forming the 1st fau, the highest terraces and part of the s5 surface (“a” and “b” in fig. 5) started during the mis 22 (ca. 870 ka bp) and ended before the mis 11 (ca. 400 ka bp). the glaciofluvial sediments of the 2nd fau, forming also part of surface s5 (“c” in fig. 5), are dated to the mis 10 (ca. 380-340 ka bp). the glaciofluvial and lacustrine sediments (“d” in fig. 5) forming terrace s4 can be dated to the mis 8 (ca. 280 -240 ka bp). the glaciofluvial sediments (“e” in fig. 5) which form a large part of surface s5 and the terraces (5a, 5b, 5c, 5d) in the area near the moraines are dated to the mis 6 (ca. 180-130 ka bp). the glaciofluvial sediments (“g” in fig. 5) that form terrace s7 could have been deposited during the mis 4 (mis 4?) but their chronological framework is definitely bracketed between the end of the mis 6 glacial maximum (ca. 140 ka bp) and the beginning of the mis 2 (ca. 30 ka bp). nearly in the same period, or later, in the northern plain, surface l1 was shaped. the last glaciofluvial sediments (“h” in fig. 5) forming terrace s8 are dated to the mis 2 (ca. 30-14 ka bp). the most recent sediments (i, l, m, in fig. 5) forming terraces t9, t10, t11 are dated to the late holocene (ca. 4 ka bp to the present). 5. considerations on the different thickness of glaciofluvial and fluvial sediments data show that in the study area the thickness of glaciofluvial and fluvial sediments, dated between 870 ka bp and the late holocene, can be quite different (fig. 8). in general the thickness is greater (reaching 70 m) north of the thrust fronts (which match the lucedio and cavourrina faults and the crescentino and morano po flexures). south of the thrust front, the thickness of the glaciofluvial and fluvial sediments is always less than 20 m. in particular, between fontanetto po and the area just east of trino, along the younger terraces, the sediment thickness is less than 10 m. because the boreholes are mainly sited in the area between trino, the rit and crescentino, the thickness of the glaciofluvial and fluvial sediments forming the south-eastern vercelli plain is less known. in order to evaluate the sediment thickness of the eastern plain, the thickness of the sediments containing phreatic groundwater reported in hydrogeological studies (regione piemonte, 2004; varalda et al., 2006) has been used. in fact, the hydrogeological studies carried out by enel (1984) indicated that the base of the phreatic groundwater matches the base of glaciofluvial sediments. glaciofluvial sediments are thickest in the plain between lamporo and the area nw of the rit (fig. 5; 7; 8) where the very weathered sediments of the 1st fau are exposed. in the area nw and w of the rit, the isopachs are nearly parallel to the lucedio fault and show that the bottom of the 1st fau forms two depressions, elongated sw-ne, divided by a small ridge. the northernmost depression (nd in fig. 8) lies near the axis of the syncline in the pliocene and pleisto 16 giraudi c. 17 cene marine sediments, and its depth increases from east to west, in a direction opposite to that of rivers. the southernmost depression (sd in fig. 8) lies near the lucedio fault and is closed to the sw. north of crescentino and near tricerro, the isopachs are transversal to the lucedio fault and crescentino flexure and assume a direction approximately n-s. in the plain east of trino, the ns isopachs are nearly parallel to the eastern branch of the cavourrina fault. lastly, starting from the area just west of morano po and as far as casale monferrato, the isopachs have a direction nearly parallel to the flexure and to the northern slope of the monferrato hills. profiles 1 and 2 in fig. 6 and a-d in fig. 9 show the variations in the sediment thickness. in the profiles ad (fig. 9) it can be observed that there are increases in sediment thickness both west and east of the area between fontanetto po and trino. moreover, west of fontanetto po, the bottom of the sediments dips to the west, therefore in a direction opposite to the slope of the plain. the westward dip of the bottom of the sediments forming the older terraces is greater than that of the most recent deposits. the base of the sediments of terrace s7 lies ca.18 m below that reached east of fontanetto po, while the base of the sediments of terrace t8 is 2 m below. 6. data on minor morphological features in the vercelli plain other secondary morphological evidence can be analyzed and taken into account, such as the change of the inclination of the terrace surfaces. some observations about small changes of the terrace surfaces, due to the presence of different sedimentary units, were reported above. in this chapter some anomalous slope inclinations observed in the southern part of the plain will be discussed. each profile in fig. 9 refers to the surface of a single terrace. profile d represents the surface of terrace s7, profile b that of s8, profile a that of terrace t9, and profile c that of surface l2. on the profiles the thickness of the sediments forming the terraces is also reported. all the profiles show anomalous slope inclination values in the area between trino and morano po (fig. 9), where the terrace surface inclination is around 0.22 % while in the area west of trino it is between 0.09 and 0.15% and east of morano po between 0.12 and 0.17%. between the two gently dipping sectors from the profiles in fig. 9 a rough value of the scarp height can be estimated. by projecting the slope measured in the western surfaces eastward to the area with the anomaly, it is possible to evaluate the difference between the eastern ground surface and the virtual elevation of the western surface. this method allows us to obtain a height difference of ≥7 m for terrace s7, of ≥6 m for s8, and of about 2 m for terraces t9 and l2. the anomaly coincides with the area where the glaciofluvial sediments thicken. it is worth noting that all the profiles show that, west of fontanetto po, even if the thickness of the sediments increases, no superficial anomaly can be observed. 7. discussion stratigraphy, facies, age and distribution of the sediments and terraces, are useful for the discussion of the geological evolution of the vercelli plain starting from the mis 22. in the first part of the chapter the impact of climatic variations will be considered, and then the stratigraphic data will be analyzed in order to obtain useful information for assessing the tectonic activity that occurred during the last 870 ka. 7.1. the impact of climatic variations and interactions between sedimentation and tectonic activity the impact of climatic variations on the evolution of the vercelli plain is clear, as the plain was formed mainly by glaciofluvial sediments, dated between mis 10 and mis 2, connected with the glacial advances and the shaping of the ivrea moraine amphitheatre. also the erosion surfaces that separate the different glaciofluvial sedimentary bodies can be ascribed mainly to the glacial retreats that took place during the interglacials. muttoni et al (2007) suggest that also the grain size increase of the sediments dated to the mis 22 was caused by climatic variations. nevertheless the evolution of the sedimentary units quaternary studies as a tool to validate assumptions about seismic hazard ... fig. 8 map of the isobaths of the base of glaciofluvial and fluvial sediments and tectonic structures active after the sedimentation of the 1st glaciofluvial and fluvial unit. 18 giraudi c. fig. 9 topographic profiles and stratigraphic outlines in the southern vercelli plain. the profiles are based on 5 m contour lines reported on the “carta tecnica regionale” at a scale of 1:10.000 in the piemonte region. the stratigraphic data are from enel (1984) boreholes and from regione piemonte (2004). 19 and the terraces indicates that the climatic impact on the plain evolution changed through time. starting from mis 10, the evolution of the plain is characterized by alternating phases of aggradation (glaciofluvial sedimentation) and erosion and pedogenesis. erosion and pedogenesis occurred between the end of one glacial phase and the start of a new one. in the mediterranean area (macklin et al., 2002), also in places very far from the glaciers, during the interstadials, the rivers incised the sediments deposited during the preceding cold stages, while on the terraces surface the soils evolved. at least the alternating phases of aggradation and erosion of the late holocene terraces were climatically driven, as evidence by giraudi (1998). therefore climatic variations have had a great impact on the evolution of the vercelli plain during the last 400 ka. for the period preceding the mis 10, that is during the sedimentation of the 1st fau, the comparison between the parts of the plain lying north and south of the lucedio fault shows data that seem to be in contrast with the hypothesis of an evolution driven mainly by the climate. the plain north of the lucedio fault is formed by sediments up to 70 m thick, without any evidence of erosion surfaces, heavily weathered at the top, which can be dated between mis 22 and mis 12. south of the fault, the sediments having a similar age have been eroded or form (on the rit) three different sedimentary bodies whose bases are cut into the tertiary bedrock at progressively lower altitudes. the entire thickness of the three sedimentary units is between 35 and 45 m. the difference in sedimentation between the areas north and south of the fault cannot be ascribed to climate variations. we believe that, to the north, no strong erosion phases occurred because subsidence prevailed, while to the south the alternating phases of limited aggradation and strong erosion could have been produced by the interaction between tectonic uplift and variations in fluvial regime driven by climate changes. michetti et al. (2012), using a boundary r-surface sequence obtained from the stratigraphic data of oil wells, evidenced that the surface (corresponding to the base of the 1st fau of this paper) is uplifted and eroded at the top of the buried thrust fronts of the northern central po plain, while in the basins lying outside the fronts, the surface lies below very thick sedimentary cover. it can be therefore assumed that the shape of the 1st fau bottom enables the subsidence rate and the distribution and geometry of tectonic structures in the study area to be assessed. studies on the tertiary and quaternary sediments forming the monferrato hills and the basin north of the monferrato thrust front (dela pierre et. al., 1995) show that phases of subsidence of the basin can be correlated to the activity of the thrust front. mariotti & doglioni (2000) state that the subsidence in the foredeeps can be ascribed to the load of thrust sheets and/or to the slab pull effect. the pleistocene subsidence of the area external to the thrust front is well known and appears to continue the pliocene trend (sgd’i, 1969a; bigi et al., 1990; dela pierre et al., 1995; irace et al., 2009). 7.2. tectonic interpretation based on stratigraphic data interpretation of the anomalous changes in thickness and in altitude of the bottom of the 1st fau and younger sediments makes it possible to evaluate the tectonic activity and the deformation rate of some areas of the plain. elements showing tectonic deformations connected with the monferrato thrust front, but also with structures crossing it are discussed below. 7.2.1. tectonic deformations connected with the monferrato thrust front the thickness variations, the dip and the difference in the sedimentation of the 1st fau are reported in fig. 7 and fig. 8. as evidenced above, apart from the rit, the 1st fau was not found south of the lucedio fault and in the tricerro area, probably because it was eroded. the thrust front, forming the boundary between the two geologically different areas, therefore played a role in the 1st fau deformation. the 1st fau is formed by glaciofluvial sediments of rivers flowing from the northern and western quadrants, but its bottom dips in different directions. in the northernmost area the 1st fau dips gently to the south. the dip appears regular because the dora baltea river flowed from the n and nw. near the lucedio fault, the 1st fau changes its slope, dipping toward the northern quadrants and assuming a direction contrary to the river flow. the change of the inclination can be ascribed to tectonic deformations. the area where sediments dipping to the north join those dipping to the south (sections of fig. 7) is the place where sediments reach their maximum thickness. in the subsidence area w and nw of the rit, the bottom of 1st fau sediments (fig. 8) shows the presence of two depressions (nd and sd) divided by a ridge (ir). the three features have a sw-ne direction nearly parallel to the lucedio fault. the northernmost depression (nd) matches the axis of the syncline deforming also the base of the pliocene marine sediments. the nd bottom cannot have been shaped only by rivers, having also been deformed by tectonic activity. in fact, the base of the 1st fau dips to the wsw, in a direction opposite to the river flow. for the same reason the bottom of the sd depression, closed to the west, cannot have been shaped only by a river. above the ir ridge the thickness of the sediments is 15-20 m less that in the nd and sd depressions. the change of the thickness could be explained by a different degree of subsidence. the deformations of the 1st fau bottom fit the hypothesis of the presence of tectonic features (probably poorly developed folds) parallel to the lucedio fault, which can therefore be linked to the activity of the monferrato thrust front. the sediments of the 1st fau do not cross the lucedio and cavourrina faults, and so it is difficult to demonstrate when the deformation ended. but if the subsidence implies thrust front activity, then the end of quaternary studies as a tool to validate assumptions about seismic hazard ... the subsidence could imply the end of the tectonic compression. the end of the subsidence north of the lucedio fault is shown by the heavily weathered top of the sediments of the 1st fau that are exposed near the axis of the subsiding area. in fact, if the subsidence had continued, the (now) weathered sediments would have been completely covered by younger ones. it follows that the subsidence ceased before the end of the 1st fau sedimentation (mis 12 ca. 400 ka bp). as far as the cavourrina fault is concerned, it can be observed that its activity ceased before ca. 280-240 ka bp, because undeformed sediments of terrace s4 seal the fault. the fault lies not far from the western, northern and eastern scarps that form the boundaries of the rit, while no isolated ridge is preserved in the longer and wider area uplifted by the lucedio fault. the presence of the rit, and the preservation of the 1st fau sediments lying on it, suggest that the cavourrina fault activity produced an uplift stronger than the lucedio fault. we cannot exclude that the cavourrina fault activity continued also after 400 ka bp. section b in fig. 7 (in a sse-nnw direction) shows that the difference in altitude of the base of the 1st fau sediments between the area where the thickness is greater (nd depression, fig. 8) and the uplifted area (rit) can be estimated as about 80-85 m. nevertheless, the real deformation should be higher because the rit is situated further down the slope than the nd depression. section e of fig. 9 (direction ca. w-e) shows the base of the 1st fau sediments between the area west of san grisante and the rit. it evidences that the base of the sediment is uplifted near san grisante, subsiding to the east and uplifting again in the proximity of the lucedio fault and of the rit. fig. 9 shows also that the uplift of the 1st fau in the san grisante area occurs in the area north of the fault. in the area between morano po and casale monferrato, the thickness of the glaciofluvial and fluvial sediments younger than the mis 22 increases towards the north and the isopachs lie parallel to the northern monferrato slope. the trend of the isopachs is similar to that of the area s and sw of crescentino. the two areas show the same geological characteristics already evidenced by the tertiary bedrock. the similarity between the two zones enables us to assume that also the isopach trend between morano po and casale monferrato was produced by a flexure that probably corresponds to a blind thrust front (fig. 1). 7.2.2. tectonic deformations crossing the monferrato thrust front the trend of the isobaths of the base of the glaciofluvial and fluvial sediments indicates that independent tectonic deformations of the monferrato front took place. in fact, in the areas n of crescentino and ne of trino, the isopachs assume an approximately n-s direction, crossing the crescentino flexure and the lucedio fault (fig. 6, profiles 1-2; fig. 8). in particular, in the crescentino area the isopachs in a n-s direction continue also well to the north of the thrust front. the uplift of the 1st fau base near san grisante, pointed out above (section e, fig. 9), seems to have been produced by n-s deformations. both the rit and terrace s4 north of crescentino lie in the northern portion of the areas affected by n-s tectonic deformations (fig. 8). the southern boundaries of the areas affected by these deformations are near castel verrua and camino, where the hills form headlands within the alluvial plain. the n-s deformations, possibly, affect the plain, both north and south of the lucedio fault and crescentino flexure, and the monferrato hills. on terrace s4, north of crescentino, the top of the 1st fau sediments, older than glaciofluvial and palustrine deposits dated to the mis 8, is strongly pedogenized, but the soil is eroded, at least in part. probably the deformation phase along the n-s structure started before the sedimentation of the palustrine deposits and favoured the erosion of the soil. the tectonic deformations along the n-s structure in the trino area seem to be dated at the mis 8. in fact, the sedimentary facies of deposits forming the terrace s4 and the thickness of the top sediments (from ca. 4 to 6 m) highlight a decrease of the river energy and the development of a wide marsh on the flood plain, which had never formed before. the changing sedimentary facies fits the hypothesis of difficult drainage to the east, most likely caused by the slow uplift of the area lying nne or ne of terrace s4. in the area south of the rit, the profiles in fig. 9 show that between fontanetto po and the trino area, to the monferrato hill slopes, the glaciofluvial and fluvial sediments are less than 10 m thick. west of fontanetto po, sediments become thicker and their base dips to the west, that is, against the river flow. also east of trino (fig. 9), in the area where the terrace surfaces show an anomalous slope inclination, sediments become thicker, and the isopachs have a n-s direction. in the area where the glaciofluvial and fluvial sediments are less than 10-20 m thick the bedrock is of tertiary marine sediments, while where the thickness exceeds 20 m the bedrock consists of lower pleistocene continental sediments. therefore in the area where the thickness of the glaciofluvial and fluvial sediments is less, the stratigraphic gap is greater due mainly to stronger erosion. the thickening of sediments to the west and east can be observed also near tricerro, north of the lucedio fault (fig. 6, profiles 1, 2). whole data suggests that an uplift occurred mainly in the area between fontanetto po and trino, but the area is elongated to the south to the monferrato hills, and to the north at least to tricerro. a tectonic structure could exist east of the uplifted area. in fact, the increase in the thickness of the glaciofluvial sediments observed east of trino, evidenced by the isobaths running ca. n-s and crossing the flow direction of rivers, cannot have been produced by rivers alone. due to the lack of borehole alignments, it is not clear if the structure is a fault or a flexure. thus, it can be assumed the presence of an undefined tectonic element (salera line), which drove the subsidence of the eastern area. based of the isopach trend, the salera line could also reach tricerro. 20 giraudi c. 21 in the salera area there is also a flow of saline water from the tertiary bedrock (enel, 1984). according to the small-scale cartography reported in irace et al. (2009), along a belt roughly corresponding to the salera line, also the isobaths of the upper pliocene base are in a direction ca. n-s and the pliocene sediment thickness increases towards the east. faults and lineaments running n-s have been observed in the monferrato hills but are not so common. according to dela pierre et al. (2003), the paucity of n-s structures in an area having many faults, anticlines and synclines with different directions could be due to their recent (pliocene and pleistocene) age. the salera line seems the northern continuation of a strongly asymmetrical syncline lying ca. n-s, at the mouth of the cerrina valley in the po plain, pointed out by sgd’i (1969a). furthermore, the hypothetical continuation southwards of the salera line would cross the po river bed in the place where marine sediments are really strongly affected by tectonic deformation. west of the salera line, the eocene marine sediments, lying below fluvial deposits or outcropping in the po river bed, reach nearly the latitude of trino, while east of the line they reach only the latitude of morano po. therefore, it is possible that the salera line produced oblique deformations or that its activity changed in the course of time. the lucedio fault ends eastward against the salera line or, alternatively, it could continue in the salera line. in other words, this latter might have played a role in the migration northwards of the thrust front and could correspond (although with a different direction) to the transcurrent or transpressive fault hypothesized by costa (2003) in the same area. nevertheless, starting at least from mis 10, the salera line seems to have produced only the subsidence of the area east of trino. to sum up, the salera line seems to be a ca. n-s fault with complex kinematics extending from tricerro to the cerrina valley in the monferrato hills. all the structures active during the last 870 ka are reported in fig. 10. 7.3. evaluation of the uplift rate as observed above, the geological and morphological features show strong differences between the uplifted area south of the lucedio-cavourrina faults and those north of these. the features are the result of climatic variations and two different phases of tectonic activity. the maximum difference between the elevation of the 1st fau base (dated ca. 870 ka bp) in the two areas is more than 80-85 m, and may be estimated as ca. 115 m (fig. 7, section b); thus, considering that the activity of the lucedio and cavourrina faults ended before 400 ka bp, the mean uplift rate of the southern area linked to thrust front activity was 0.25 mm/yr. however in each area differences can be observed in the elevation of the 1st fau base. the deformation produced by the n-s uplift area between trino and fontanetto po can be estimated using the variations in the altitude of the base of the glaciofluvial and fluvial sediments where the base dips against upstream, that is, west of fontanetto po (fig. 9). in that area, the base of the sediments dated mis 4? lies at an elevation 22 m lower than east of fontanetto po. as without tectonic deformation the inclination of the base of the sediments should be from west to east, the area between fontanetto po and trino underwent a minimum uplift of 22 m. based on the age of the sediments (an interval between 140 and 30 ka bp), the uplift rate is thus >0.16 mm/yr. if the deformation (more than 12 m) of the base of the sediments dated mis 2, ca. 30-15 ka old (fig. 9) is considered, an uplift rate >0.4 mm/yr can be calculated. the uplift rate of the sediments forming the t9 terrace, dated to the last 2-1.5 ka but whose base could be dated to 3-4 ka, can be obtained using two different data. the first is the value of the dip against upstream, and the second is the anomalous inclination of the ter quaternary studies as a tool to validate assumptions about seismic hazard ... fig. 10 active tectonic structures during the quaternary. race surface. the inclination against upstream of the sediment base, west of fontanetto po, is about 2 m (fig. 9) and therefore the uplift rate could be nearly 0.5 mm/yr. the slope inclination anomaly of the s9 surface east of trino is nearly 2 m in correspondence with the salera line, and the uplift rate of the area during the last 2 ka should therefore be nearly 1 mm/yr. however, taking into account the uncertainty of the method, such a rate should be considered the maximum possible. on the whole, over the last 140 ka, we can estimate an uplift rate between 0.16 and 0.5 mm/yr. studies carried out in the torino hills (boano et al., 2004), sited west of the vercelli plain, evaluate 1 mm/yr the uplift rate from the middle pleistocene to the present. within the uplift area between fontanetto po and trino, the southward lowering of the altitude of the base of the glaciofluvial and fluvial sediments and of the terraces surfaces suggests that the northern area is uplifted more than the southern one. 8. tectonic interpretations based on morphologic anomalies and fluvial diversions studies reported in recent papers on the tectonics of the po plain (burrato et al. 2012a; 2012b; michetti et al., 2012) have used presumed morphological anomalies and changes in the course of rivers, jointly with structural data, to evaluate the modern tectonic activity and the deformation rates that can be ascribed to structures buried below alluvial sediments. the epicentral area of the recent seismic crisis (2012) of the emilian plain (galli et al., 2012) matches one of the areas where, according to the previous hypotheses, the drainage was strongly conditioned by the buried tectonic structures. the use of the drainage variations for estimating the activity of structures buried below the alluvial sediments of the po plain, therefore, may sometimes give reliable results. the morphological anomalies, the presence of an anomalous number of terraces and the river diversions, analyzed in this paper, provide the palaeogeographic and chronological data needed in order to complete the observations on the vercelli plain presented, in a less detailed way, in some papers (gsqp, 1976; burrato et al. 2012a; 2012b; michetti et al., 2012). the areas with topographic anomalies and complex morphology lie between the axis of the syncline north of the thrust front and the monferrato hills (fig. 2; 4; 5), i.e. the area where the stratigraphic data show the presence of quaternary tectonic deformations. the presence of s8 (ca. 30-14 ka bp) south and north of the po can indicate possible clues of tectonic activity. in fact between trino and casale monferrato, s8 is not far from the po bed, while ne of casale monferrato some small remnants of the s8 terrace are 8-10 km north of the river. also south of the po the s8 terrace remnants suggest an anomaly. the terrace is preserved only west of verrua savoia and east of casale monferrato. it is likely that the lack of s8 in the intermediate area was caused by the erosion linked to the migration of the river southwards produced by the uplift of the plain north of crescentino and trino. many river diversions highlighted by the geometry and extent of terraces of the studied area can have been produced by sedimentary and erosion processes, determined by climatic variations or tectonic deformations. the dominant influence of the climate on the evolution of the plain has already been discussed and shows a strong link between sedimentation and erosion phases, and climatic changes. certainly, in the nw vercelli plain, the dora baltea river bed migrated many times during the last 870 ka, due to the change of shape and extent of the glacial fronts and of the position of the glacial meltwater streams. during the same glacial stages, glacier melting produced more than one meltwater stream fed by different glacial lobes (carraro et al., 1975; gianotti et al., 2008). some diversions of alpine rivers and of local streams that took place in the last 2 ka were, or could have been, produced by human impact (rivers cervo and sesia in the vercelli area). many river diversions, recognized in the southern vercelli plain, occurred during the same sedimentation phase and can have been produced by the change in the inclination of the river bed as a consequence of variations in the solid load transport. however most river diversions can have been produced by tectonic deformations along the structures described above. during the period between mis 22 and mis 12 (~0.87-0.4 ma), the terraces show a diversion to the nw of the river, formed by the dora baltea and the dros, which flowed south of the rit (fig. 11a). the diversion is compatible with the uplift of the area south of the monferrato thrust front, produced by the compression that induced also the deformation of the 1st fau sediments. in that period, the northern slope of the monferrato hills should have been not very far from the rit. during the period between mis 10 and mis 8 (~0.35 -0.25 ma), in the crescentino area, the river changed its course, bypassing san grisante to the north (fig. 11b). the age of the diversion is the same as the beginning of the deformation along the n-s structure. during the same period, north of the rit, a diversion eastwards of the dora baltea and the migration of the confluence with the dros river occurred (fig. 11b). the diversion may have been produced by the uplift of the area east of lamporo. despite the climatic variations that occurred between mis 8 and mis 4?, the river continued to flow north of the lucedio fault, showing that the climate did not produce river diversions. the river ran parallel to and partly overlapped the thrust front. the position of the river was determined by the presence of the glaciofluvial fan, which limited the lateral variations toward the north, and by the presence of terraces (or of the hillslopes) to the south. the morphological situation was substantially equivalent to that which currently determines the position of the po from turin to crescentino and from morano to casale monferrato. during mis 4? (~0.14-0.03 ma), a series of diversions occurred (fig. 11c). initially the river (baltea + 22 giraudi c. 23 quaternary studies as a tool to validate assumptions about seismic hazard ... fig. 11 fluvial diversions and tectonic mobility of the vercelli plain during the period between mis 22 and mis 12 (11a), between mis 10 and mis 6 (11b), during mis 4? (11c), and between mis 3 and mis 1 (11d). dros), which flowed north of the rit, migrated slightly towards the south eroding the northern slope of the ridge, then underwent diversions that made it flow to the west and south of the rit, and later to the west and south of the terrace s4 near san grisante. these diversions are compatible with the uplift along the n-s structures in the trino and crescentino area. during this period, in the area between crescentino and trino an anomalous situation began in the relationship between the position of the river and the monferrato thrust front, because the river crossed the front and began to flow behind it, showing that the activity of the thrust had ceased. during the upper pleistocene a diversion also occurred of the po towards the plain north of the monferrato hills (carraro, 1976; carraro et al., 1995), whereas, previously, the river flowed to the south. the po diversion could have occurred during mis 4?, just during the phase of continuous diversions of the river in the southern vercelli plain. during mis 2 mis 1 there was a continuous migration to the south of the po and the dora baltea rivers (fig. 11d) and a significant shift to the west of the confluence of the two rivers. the river diversions that occurred during the mis 2 mis 1 period are compatible with the uplift of the structures, with a n-s axis, of the crescentino and trino areas. the southward river migration, which produced a strong and continuous erosion of the northern hillslopes, implies that in the crescentino and trino uplifted areas, the uplift of the northernmost portion is greater than that of the southern one, confirming the interpretation based on the variations of the altitude of the fluvial sediment base. the extreme north-south reduction of the po river drainage basin in the stretch between crescentino and trino, described above (fig. 2), may be a consequence of the southward migration of rivers. in fact, by eroding the hillside they reduced the extent of the basins of the streams that drain into the po. in the area between fontanetto po and trino, terraces t9, t10, and t11 form a strip narrower that in the area upstream and downstream. this may be a consequence of the late-holocene uplift of the area, suggested by the deformation of the fluvial sediment base (fig. 9). in the casale monferrato area, after the formation of terrace s8, the po underwent a diversion to the north (fig. 11d). west of the town, the migration of the river from north to south can be explained by the greater uplift of the northern area of the trino and crescentino north-south structures; consequently it can be assumed that the northwards diversion of the river was caused by the uplift of the southern plain and/or by the subsidence of the plain north of the po. in the rive and balzola area, some small-scale morphological clues on the late holocene terraces could suggest stream diversions. the natural origin of the diversions is uncertain, but, if the diversions had been natural, it could have been linked to the subsidence of the area ne of casale monferrato. the small valleys (forming surface l2) cutting the river terraces show that during the mis 2 mis 1 period, also the local streams suffered many diversions (fig. 11d). in particular, in the area between ronsecco and tricerro, there are remnants of small valleys abandoned because the streams were diverted n and ne. the diversion may have been produced by the uplift of the northernmost part of the n-s structure. in the area between tricerro and costanzana some morphological features linked to the northward migration of the marcova stream have been observed. the diversions may have been produced by the uplift of the n-s structure, but also by the uplift of a narrow area (fig. 11d) parallel to the buried monferrato front. 9. relationship between tectonic deformations in the arca and beretta (1985) paper, the uplift rate of some places located near casale monferrato and the vercelli plain is reported. the uplift rate was obtained by means of the comparison between data from geodetic measurements carried out in 1897 and in 1957 ad. in particular, the points lying along a section from casale monferrato to vercelli, that cross the monferrato thrust front, indicate an uplift rate of 4.32 mm/yr in the area south of the front, 1.37 mm/yr at villanova monferrato, located north of the po, between the front and the syncline axis, 1.67 mm/yr at stroppiana and 0.62 mm/yr at vercelli, located north of the syncline axis. the area south of the monferrato front has an uplift rate four times greater than in the area north of it. however, the section does not allow a threedimensional interpretation and it is therefore not possible to determine whether the deformation occurred exactly on the flexure or on the front, or along other structures transversal to the front. the morphological features that suggest a possible tectonic activity in the plain near casale monferrato are dated to the upper pleistocene. no clues showing older deformations have been found. the age of the tectonic activity makes it unlikely that the uplift was produced by the monferrato thrust front. 10. summary of tectonic interpretations, considerations on seismicity and on aseismic movements in the area the stratigraphic and morphological characteristics of the vercelli plain allow us to assess the evolution during two periods, the first between 870 and ca. 400 ka bp, the second following 400 ka bp. in the older period, evolution was influenced by the subsidence of the axial area of the syncline lying north of the lucedio fault and of the crescentino and morano po flexures, while the area between the syncline and the fault and the flexures was less subsiding, and the area south of the fault and the flexures was subject to uplift. the lucedio fault was active until ca. 400 ka bp while the cavourrina fault could have been active also later, but before 280 ka bp. as discussed above, these faults constitute the thrusts front, and therefore we can conclude that the main compression in the monferrato 24 giraudi c. 25 front ended before or about 400 ka bp. during the thrust activity the salera line and the crescentino fault acted as transcurrents or transpressives, according to the costa (2003) hypothesis. because the thrust fronts are reported on maps at a scale lower than that of the maps in this paper, and there is uncertainty about their exact position (fig. 1), it is difficult to establish in detail whether the crescentino and morano flexures lie on stretches of the monferrato thrust front, but it is likely that the flexures are superficial effects produced by the blind thrust. interpretation of the data suggests that the fronts corresponding to the lucedio and cavourrina faults and to the crescentino and morano po flexures were active at least in the period between 870 and 400 ka bp. the deformation of the sediments shows that the tectonic compression acted in different ways on the various stretches of the front during the same periods. the dip of the sediments, the degree of deformation and the dip of the fault planes indicate a clear difference between the fronts corresponding to the lucedio and cavourrina faults (the farthest from the monferrato hills) and the front that produced the flexures. according to the published papers (sgd’i, 1969a; sgd’i, 1969b; pieri and groppi, 1981; cassano et al., 1985; dela pierre et al., 2003a; festa et al., 2009), excluding the area of the lucedio and cavourrina faults, the buried thrust front of the monferrato-torino hills is always near the northern hill slope. moreover, the tertiary and quaternary sediments lying outside the thrust front show an inclination and dip very similar to that observed in the crescentino flexure. it can be deduced that, although framed within the activity of the monferrato thrust front, the lucedio and cavourrina faults and the other associated tectonic structures (crescentino fault and salera line) acted in a different way. the anomalous tectonic evolution of this part of the thrust front started well before the quaternary. in fact, the balzola fault (fig. 4; 5), which is a lower pliocene thrust front lying north of the lucedio fault (sgd’i, 1969a; pieri & groppi, 1981; cassano et al., 1985; bigi et al., 1990; enel, 1994; dela pierre et al., 2003a), is nearly parallel to the younger thrust front. naturally the data on the quaternary evolution are related to a short period, compared to the length of the tectonic phase, and cannot properly explain the tectonic anomaly of this part of the monferrato thrust front. in the last 400 ka, the only possible tectonic motions affect n-s trending structures near crescentino and trino. the activity of these structures became stronger during the last 250 ka. according to the deformation of the base of the sediments dated at the last 140 ka, the uplift rate of the north-south trino structure was between 0.16 and 0.5 mm/yr and the northern part of this structure uplifted more than the southern part. the n-s deformations were not found in other places north of the collina di torino-monferrato. it follows that these deformations are anomalous, but correspond to an area of anomaly since the lower pliocene. as the lucedio and cavourrina faults are sealed by middle pleistocene sediments, the n-s deformations can hardly be connected with the thrust front activity. is not clear whether the north-south uplifted areas are included between north-south striking faults or flexures, but east of trino lies the salera line, a very important structure with a long and complex activity. the line seems to continue from tricerro to the cerrina valley, inside the monferrato hills, reaching a length of ca 20 km. we cannot completely exclude the uplift, since mis 4?, of a short, narrow area east of tricerro (fig. 11c;d) parallel, but external, to the lower pliocene monferrato thrust front. the seismic catalogues show, for the studied area, the absence of any earthquakes between 1000 to 2006 ad (rovida et al., 2011; rsni, 2014a) and the presence, during the period covered by instrumental record, of only four events of ml ≥ 2 (rsni, 2014 b) located in trino, camino and gabiano, but the depth of the epicentres of two events near trino has been assessed as more than 50 km below ground level. because the area of casale monferrato, according to the arca and beretta (1985) geodetic data, was affected between 1897 and 1957 ad by vertical movements with values greater than 4 mm / yr -1 but there were no earthquakes, one must conclude that the area is characterized by significant aseismic movements. the aseismic uplift rate of casale monferrato is at least eight time greater than the maximum rate that can be assumed for the trino area on the basis of the geological data. 11. conclusions the study of the quaternary geological evolution of the vercelli plain shows complex morphological, stratigraphic and tectonic variations. with reference to the main aim of the work, i.e. the validation of the seismotectonic interpretations and the associated seismic hazard implications made by various authors, we can observe the following. only some stretches of the buried fronts, which were reported or assumed as active by various authors (fig. 1), have influenced or induced deformation in the quaternary sedimentation and drainage. among the buried thrust-fronts which were active in the past 870 ka (i.e., lucedio and cavourrina faults), and the flexures of crescentino and morano po, only the first two produced the most appreciable deformation. the salera line, along with another possible fault (crescentino fault), may have played a key role in the northward shift of the thrust fronts of lucedio and cavourrina. over the past 400 ka the monferrato front has no longer been active, or its activity has been very low because the base of the ii fau seals it. thus, starting at about 400 ka bp, the tectonic evolution of the thrust and of the foredeep basin differed substantially from that of the fronts of the emilia and ferrara folds which are considered active and seismogenic. from mis 10 or before, the crescentino and trino structures, transversal to the monferrato front contributed to the uplift of areas elongated approximately in a ns direction. the uplift affected both the northern quaternary studies as a tool to validate assumptions about seismic hazard ... monferrato slope and areas in the plain south and north of the thrust front. the uplifted trino area was limited to the east by the salera line. there are no indications of structures (faults or flexures) located to the west of the trino area or forming the limits of the uplifted crescentino area, although their presence might be assumed. it is possible that the aseismic uplift, geodetically recorded in the area of casale monferrato, is connected with a structure similar to those of trino and crescentino. it is possible that there is a structure that produces the uplift of a small area to the east of tricerro. the structure would lie outside of the oldest monferrato front, but its trend is sub-parallel to this. it is possible that the southern vercelli plain was affected by tectonic deformation even in the late holocene. for the period between mis 4? and the present, the maximum uplift rate of the structure of trino is evaluated as between 0.16 and 0.5 mm/yr. the most important identified structure, that was active also during the upper pleistocene and the holocene, is the salera line, an unknown structure with a complex kinematics, which might continue to the south, inside the hills, for a length of about 20 km. the presence of aseismic uplift (up to 4 mm/yr in the area of casale monferrato) in an area with very low seismicity, could justify the deformation of sediments and of terrace surfaces that occurred in the past thousands of years. however, the aseismic uplift, tested only for a few tens of years, may not be significant or may be only one aspect of the long-term tectonic evolution. in addition, as elsewhere in the world, there is the possibility that the area is subject to earthquakes with very long return periods, not reported by the seismic compilations. the detailed study of the geological evolution of the vercelli plain has therefore made it possible to characterise the tectonic structures that were active during the quaternary and to assess the uplift rate. the recent vertical movements of the surface, however, are not associable with the monferrato thrust front, as suggested previously, but to north-south unknown structures, transversal to the front, which seem to affect both the plain and the northern portion of the monferrato hills. as a concluding remark, it is unlikely that the seismicity of the easternmost apennine fronts (emilia and ferrara folds) can provide useful information to assess the seismic hazard of the vercelli plain and of the northern monferrato. aknowledgements: we thank paolo galli who greatly improved the manuscript with their accurate revision and edi chiarini for the english revision. references ajassa r., biancotti a., motta, m. (1990) carta altimetrica dell'alta pianura piemontese, atti accademia delle scienze di torino, classe di scienze fisiche, matematiche e naturali, 124, 29-35. arca s., beretta g.p. (1985) prima sintesi geodeticageologica sui movimenti verticali del suolo nell’italia settentrionale (1897-1957). boll. geodes. sc. affini, 44 (2), 125-156. arduino e., barberis e., carraro f., forno m.g. (1984) estimated relative ages from iron-oxide/total iron ratios of soils in the western po valley, italy. geoderma, 33, 39-52. arpa piemonte (2014) banca dati geotecnica. available at: http://webgis.arpa.piemonte.it/flxview/ geoviewerrisknat/index.aspx bigazzi g., bonadonna f.p., ghezzo c., giuliani o., radicati di bronzolo f., rita m. (1981) geochronological study of the monte amiata lavas (central italy). bull. volcanol., 44, 455-465. bigi g., cosentino d., parotto m., sartori r. & scandone p. (1990) structural model of italy, consiglio nazionale delle ricerche (cnr), progetto finalizzato geodinamica, quaderni de "la ricerca scientifica", 114 (3), 1:500.000 scale, firenze, selca. boano p., forno m.g., lucchesi s. (2004) pleistocene deformation of the collina di torino inferred from the modelling of their fluvial succession. il quaternario-italian journal of quaternary science, 17 (2/1), 145-150. bonadeo p., brunamonte f., michetti a.m., livio f., fioraso g. (2010) paesaggio sismico dell’arco del monferrato: analisi preliminare. gngts, atti del 16° congresso nazionale, 93-97. burrato p., f. ciucci, g. valensise (2012a) un approccio geomorfologico per la prima individuazione di strutture potenzialmente sismogenetiche nella pianura padana. gngts, atti del 18° congresso nazionale, 18pp. burrato p., vannoli p., fracassi u., basili r., valensise g. (2012b) is blind faulting truly invisible? tectonic-controlled drainage evolution in the epicentral area of the may 2012, emilia-romagna earthquake sequence (northern italy). annals of geophisics, 55, 4; doi:10.4401/ag-6182. carraro f. (1976) diversione pleistocenica nel deflusso del bacino piemontese meridionale: un’ipotesi di lavoro. gruppo di studio del quaternario padano, quaderno 3, 89-100. carraro, f., medioli, f., petrucci, f. (1975) geomorphological study of the morainic amphitheatre of ivrea, northwest italy. bulletin, 13. royal society of new zealand, wellington. carraro f., forno m.g., ricci b. (1980) ricostruzione preliminare dell’evoluzione plio-pleistocenica dell’area corrispondente ai rilievi delle langhe, del monferrato e della collina di torino. contributi alla realizzazione della carta neotettonica d’italia. cnr progetto finalizzato geodinamicasottoprogetto “neotettonica”. pubblicazione n. 356, 315 -330. carraro f., lanza r., perotto a., zanella e. (1991) l’evoluzione morfologica del biellese occidentale durante il pleistocene inferiore e medio, in relazione all’inizio della costruzione dell’anfiteatro morenico d’ivrea. bollettino del museo regionale di 26 giraudi c. 27 scienze naturali, torino, 9 (1), 99-117. carraro f., collo g., forno m.g., giardino m., maraga f., perotto a., tropeano d. (1995) l’evoluzione del reticolato idrografico del piemonte centrale in relazione alla mobilità quaternaria in: polino r. & sacchi r. (eds.), atti del convegno: rapporti alpiappennino. acc. naz. sci. sc. doc, 14, 445-461. cassano e., anelli l., fichera r., cappelli v. (1986) pianura padana: interpretazione integrata di dati geofisici e geologici. 73° congresso della società geologica italiana. 1-27. costa m. (2003) the buried apenninic arcs of the po plain and northern adriatic sea (italy): a new model. boll. soc. geol. it., 122, 3-23. dela pierre f., michailov v., polino r. (1995) the tectonosedimentary evolution of the tertiary basins in the western po plain: kinematics inferred from subsidence curves. in: polino r. & sacchi r. (eds.), atti del convegno: rapporti alpiappennino. acc. naz:sci.sc.doc, 14, 129-146. dela pierre f., piana f., boano p., fioraso g., forno m.g., polino r. clari p. (2003a) carta geologica d'italia alla scala 1:50.000, foglio 157 "trino", apat, agenzia per laprotezione dell'ambiente e per i servizi tecnici dipartimento difesa del suolo, roma. dela pierre f., piana f., fioraso g., boano p., bicchi e., forno m.g., violanti d., balestro g., clari p., d’atri a., de luca d., morelli m., ruffini r. (2003b) note illustrative della carta geologica d’italia alla scala 1:50,000, foglio 157 trino. apat, agenzia per la protezione dell’ambiente e per i servizi tecnicidipartimento difesa del suolo, roma, 147 pp. de luca d.a., ghione r., lasagna m. (2005) studio idrogeologico dei fontanili della pianura piemontese. giornale di geologia applicata, 2, 377-382, doi: 10.1474/gga.2005-02.0-55.0081. de martini p. m., burrato p., valensise g. (1997) strutture attive nella pianura padano-veneta: nuove strategie di discriminazione dall’analisi congiunta di osservazioni geomorfologiche e geodetiche. abstracts congresso: “tettonica quaternaria del territorio italiano: conoscenze, problemi ed applicazioni”, 25-27 febbraio 1997, parma. enel (1984) rapporto per la localizzazione di una centrale elettronucleare nella regione piemonte. area po 1. enel direzione delle costruzioni, roma. xix volumes, unpublished. facchin p. (1997) ascia dell’ età del bronzo. notiziario di studi e ricerche, n. 1, 56. ed. tridinum, trino. fedele f. (1976) paleolitico medio a trino. rapporto sulle ricerche 1976. gruppo di studio del quaternario padano, quaderno n. 3, 59-76, litografia massazza e sinchetto, torino. festa a., boano p., irace a., lucchesi s., forno m.g., dela pierre f., fioraso g., piana f. (2009) note illustrative della carta geologica d’italia alla scala 1:50,000, foglio 156 torino est. apat, agenzia per la protezione dell’ambiente e per i servizi tecnicidipartimento difesa del suolo, roma, 143 pp. fozzati l., giraudi c. (1983) camino monferrato, fiume po. quaderni della soprintendenza archeologica del piemonte, 2, 148. galadini f., falcucci e., galli p., giaccio b., gori s., messina p., moro m., saroli m.,scardia g., sposato a. (2012) time intervals to assess active and capable faults for engineering practices in italy. engineering geology, 139-140, 50-65. galli p. (2005) i terremoti del gennaio 1117. ipotesi di un epicentro nel cremonese. il quaternario, 18, 87 -100. galli p., castenetto s., peronace e. (2012) may 2012 emilia earthquakes (mw 6, northern italy): macroseismic effects distribution and seismotectonic implications. alpine and mediterranean quaternary, 25(2), 105-123. gianotti f., forno m.g., ivy-ochs s., kubik p.w. (2008) new chronological and stratigraphical data on the ivrea amphitheatre (piedmont, nw italy). quaternary international, 190,123-135. gibbard p. l., head m. j., walker m. j. c. and the subcommission on quaternary stratigraphy (2010) formal ratification of the quaternary system/ period and the pleistocene series/epoch with a base at 2.58 ma. journal of quaternary science, 25, 96-102. giraudi c. (1998) l'evoluzione del po nei pressi di trino (prov. di vercelli piemonte) tra l'eta' del bronzo ed il xvii secolo. il quaternario, 11(2), 227 -232. gsqp-gruppo di studio del quaternario padano (1976). studio interdisciplinare del "rilievo isolato" di trino (bassa pianuravercellese, piemonte), quaderno n.3, 161-253, litografia massaza e sinchetto, torino. irace a., clemente p., natalicchio m., ossella l., trenkwalder s., de luca d.a., mosca p., piana f., polino r., violanti d. (2009) geologia e idrostratigrafia profonda della pianura padana occidentale. 110 pp, 61 allegati. la nuova lito, firenze. janigro d’aquino e. (1979) reperti dell’età del bronzo a morano sul po. la provincia di alessandria, xxvi, 3, 42-43. macklin m.g., fuller i.c., lewin j., maas g.s., passmore d.g., rose j., woodward j.c., black s., hamlin r.h.b., rowas j.s. (2002) correlation of late and middle pleistocene fluvial sequences in the mediterranean and their relationship to climate change. quaternary science reviews, 21, 16331644. mariotti g., doglioni c. (2000) the dip of the foreland monocline in the alps and apennines. earth and planetary science letters, 181, 191-202. michetti a. m., giardina f., livio f., mueller k., serva l., sileo g., vittori e., devoti r., riguzzi f., carcano c., rogledi s., bonadeo l., brunamonte f., fioraso g. (2012) active compressional tectonics, quaternary capable faults, and the seismic landscape of the po plain (northern italy). annals of geophysics, 55, 5, 969-1001. muttoni g., ravazzi c., breda m., pini r., laj c., kissel c., mazaud a., garzanti e. (2007) magnetostratigraphic dating of an intensification of glacial activity in the southern italian alps during marine iso quaternary studies as a tool to validate assumptions about seismic hazard ... ms. received: marc 20, 2014 final text received: july 25, 2014 tope stage 22. quaternary research, 67, 161173. pieri m., groppi g. (1981) subsurface geological structure of the po plain, italy. quad. cnr. prog. fin. geodinamica, roma, 1-13. regione piemonte (2004) indagini e studi finalizzati alla predisposizione del piano di tutela delle acque. regione piemonte, direzione pianificazione risorse idriche. 17 pp. rovida a., camassi r., gasperini p., stucchi m. (eds.) (2011) cpti11, the 2011 version of the parametric catalogue of italian earthquakes. milano, bologna. http://emidius.mi.ingv.it/cpti, doi: 10.6092/ ingv.it-cpti11. rsni regional seismic network of northwestern italy database (2014a) mappe di sismicità strumentale 1982-2013. university of genova. available at: http://www.distav.unige.it/rsni/ita/index.html rsni regional seismic network of northwestern italy database (2014b) mappe di sismicità storica (1000-2006). university of genova. available at: http://www.distav.unige.it/rsni/ita/index.html sgd’i-servizio geologico d’italia (1966) foglio 43 “biella” alla scala 1:100.000. ii edizione. serv. geol. d’italia, roma. sgd’i-servizio geologico d’italia (1969a) foglio 57 “vercelli” alla scala 1:100.000. ii edizione. serv. geol. d’italia, roma. sgd’i-servizio geologico d’italia (1969b) foglio 56 “torino” alla scala 1:100.000. ii edizione. serv. geol. d’italia, roma. tropeano d., olive p. (1989) vitesse de la sedimentation holocéne dans la plaine occidentale du po (italie). bulletin de l’association francaise pout l’etude du quaternaire, 2, 65-71. valla p.g., shuster d.l., van der beek p.a. (2011) significant increase in relief of the european alps during mid-pleistocene glaciations. nature geoscience, 4, 688-692. varalda g.g., falco m., benazzi o., de luca d., lasagna m., casaccio d., ossella l. (2006) le acque sotterranee della provincia di vercelli. provincia di vercelli, 157 pp., saviolo edizioni, vercelli. violanti d., sassone p. (2008) il pliocene del sottosuolo di casale monferrato (piemonte, italia nordoccidentale): dati preliminari. atti mus. civ. stor. nat. trieste, suppl. 53, 233-264. zappi l. (1961) il pliocene di castel verrua. atti soc. it sc. nat. mus. civ. st. nat. milano, 100, 73-204. 28 giraudi c. microsoft word 00_indice_lm04.docx il quaternario it issn 039-3356 italian journal of quaternary sciences 24 (1), 2011113-119 the argali (ovis ammon antiqua) from the magliana area (rome) roberto rozzi1, maria rita palombo1,2 & maurizio barbieri1 1università degli studi di roma sapienza, roma 2 cnr, istituto di geologia ambientale e geoingegneria. c/o università degli studi di roma sapienza, roma correspondent author: r. rozzi < roberto.rozzi84@gmail.com> abstract: rozzi r., palombo m.r. & barbieri m., the argali (ovis ammon antiqua) from the magliana area (rome). during the middle pleistocene, the fossil subspecies was widespread from georgia to portugal, though it is scantily recorded in local faunal assemblages of southern europe. its occurrence in a few late pleistocene sites needs to be confirmed. in italy, the subspecies is recorded in the late galerian fauna of visogliano (mis 13 10) as well as in the magliana area, where an incomplete skull was found at the beginning of the last century. although the precise location where this specimen was found is unknown, on the basis of the results of the geochemical analysis performed on a small amount of sediment, sampled from the filling of the inner cavities of the horn-cores, and considering the stratigraphy of the area, the hypothesis that the skull comes from the deposits of the pg4 sequence (mis14 partim mis13) cannot be ruled out. this hypothetical remark would confirm the occurrence in italy of the argali in late galerian faunas. the dimensions of ovis ammon antiqua from the magliana area fit well within the range of variability of the larger specimens, likely males, found at la caune de l’arago (france) (mis 14-12), from which the italian specimen differs in having less twisted and more dorsoventrally curved horn-cores. riassunto: rozzi r., palombo m.r. & barbieri m., l’argali (ovis ammon antiqua) della magliana (roma). durante il pleistocene medio, la sottospecie fossile di argali è diffusa dalla georgia al portogallo ma è piuttosto rara nei giacimenti dell’europa meridionale, mentre la sua presenza in alcuni siti del pleistocene superiore deve essere confermata. in italia questa sottospecie è segnalata nella fauna tardo galeriana di visogliano (mis 13 10) e nell’area della magliana, dove, agli inizi del secolo scorso, fu rinvenuto un cranio incompleto. sebbene il luogo esatto del ritrovamento di questo esemplare non sia noto, in base ai risultati delle analisi geochimiche effettuate sul sedimento ancora presente nei cavicchi ossei e tenendo conto dell’assetto geologico stratigrafico dell’area, non si può escludere che il cranio provenga dai depositi della sequenza pg4 (mis14 partim mis13). questo ipotetico riferimento confermerebbe la presenza in italia dell’argali in faune del tardo galeriano. le dimensioni di ovis ammon antiqua della magliana rientrano nel campo di variabilità degli esemplari, presumibilmente maschi, de la caune de l’arago (francia) (mis 14-12), dai quali l’esemplare in studio, tuttavia, si differenzia per una minore torsione e una più accentuata curvatura dorso-ventrale dei cavicchi ossei. key words: argali, ovis ammon antiqua, early middle pleistocene, magliana, italy, parole-chiave: argali, ovis ammon antiqua, pleistocene medio inferiore, magliana, italia. 1. introduction a ovis species, possibly similar to ovis ammon, is first reported in europe in the early pleistocene of bulgaria (ovis sp., slivnitsa, spassov & crégutbonnoure, 1999; crégut-bonnoure, 2005; 2007), while ovis ammon antiqua was undoubtedly present in local faunal assemblages of the middle and, possibly, late pleistocene (crégut-bonnoure, 2005; 2007). in italy, the subspecies is reported in the late galerian fauna of visogliano (mis 13 10, abbazzi et al., 2000; falgueres et al., 2008) as well as in the magliana area (fig. 1), where an incomplete skull was found at the beginning of the last century (portis, 1917). the exact geographical location as well as the precise stratigraphical position of the latter specimen is uncertain. the aim of this paper is twofold: 1) to provide a further morphological description of the specimen retrieved in the magliana area; 2) to hypothesize its stratigraphical position comparing the information included in portis’ paper (portis, 1917) with geological evidence from the area as well as on the basis of new geochemical data. since ovis ammon antiqua is extremely rare in italian local faunal assemblages, a better knowledge of this specimen is useful to further detail the fossil record of the peninsula and to enhance our data on the spreading of this subspecies in southern europe. 2. the puzzling question of the stratigraphical context: geochemical inferences in 1917, portis described an incomplete skull of ovis ammon antiqua (fig. 2) that was retrieved in the magliana area by a building worker and brought to the “regio istituto geologico universitario” of rome by u. rellini. although portis did not know exactly where this specimen was found, after a detailed analysis of the deposits cropping out at “santa passera”, “del truglio”, “delle piche”, “dell’infernaccio”, “della muratella” and “del merlo” hills, he assumed the argali might have been retrieved from deposits overlaying the “pozzolane grigie” (also called “pozzolanelle”, karner et al., 2001). if portis’ hypothesis was correct, the incomplete skull of ovis ammon antiqua would have been younger than r. rozzi, m.r. palombo & m. barbieri 114 these volcanic deposits, deriving from the explosive activity of the alban hills volcanism, which are dated at357 ± 2 ka (karner et al., 2001). this would imply the presence of the argali in the central italy during mis 10 if not at the beginning of the late middle pleistocene. therefore, we have to suppose that sediments where the skull was buried in belong to a sequence not older than the pg5, but whose deposits are scantly or not present in the fosso della magliana area (milli, 1997; milli et al, 2008 and references therein). outcrops of “pozzolane grigie” are actually scanty in the magliana area, where volcanic deposits cropping out more frequently are those of the “santa cecilia formation” (including two volcanic levels dated at 614 ± 15 ka and 605 ± 11 ka, karner & renne, 1998; karner et al., 2001; funiciello & giordano, 2008). moreover occasional outcrops of “tufo pisolitico” have been reported, which have been dated at 561 ± 1 ka (karner & renne, 1998; karner et al., 2001). small clasts of these products, as well as volcanoclastic materials related to sabatini activity, are contained in a few levels of the youngest high-frequency depositional sequences (pg3 and pg4), cropping out in the magliana area (milli, 1997), which are characterized by upper shoreface deposits (pg3) and lacustrine-lagoonal deposits (pg4) (see milli, 1997; milli et al., 2008). in the study area, the sequences pg0, pg1 and pg2, which are older than the beginning of the alban hills volcanic activity, also outcrop in a number of quarry cuts. these sequences are mainly composed of fluvial and beach deposits. therefore, to clarify the stratigraphical position of the magliana specimen, the first step was to analyse a small amount of sediment, sampled from the fillings of the inner cavities of the horn-cores, aiming to check whether its origin was continental or marine. unfortunately no palaeontological content was found to support either of the two hypotheses. accordingly, geochemical analyses were performed in order to verify the presence of volcanic particles in the sediment. a representative portion of each sample was finely powdered using an agate mortar and used for chemical analysis. analyses of metals were carried out using inductively coupled plasma mass spectrometer (icp-ms) after acid total digestion (hf, hno3). analytical blanks were run in the same way as the samples and concentrations were determined using standard solutions prepared in the same matrix. results are expressed in mg/kg (tab. 1), except for fe and al, whose concentrations are expressed in percentage. the accuracy and precision of our results were checked by analysing sediment reference material. tab. 1 concentrations of trace elements expressed in mg/kg (except for al and fe, whose concentrations are expressed in percentage) and carried out using inductively coupled plasma mass spectrometer (icp-ms). concentrazioni di elementi in traccia espresse in mg/kg (tranne che per l’al e il fe le cui concentrazioni sono espresse in %) determinate mediante icp-ms. fig. 1 geological sketch of the thyrrhenian margin, central italy. 1) messinian to holocene sedimentary deposits; 2) pliocene-pleistocene lavas and volcanoclastic deposits; 3) meso-cenozoic sedimentary deposits; 4) main buried faults; 5) strike-slip faults; 6) normal faults; 7) major thrusts. the black square indicates the study area (modified after milli et al., 2008). schema geologico del margine tirrenico, italia centrale. 1) depositi sedimentari dal messiniano all’olocene; 2) lave e depositi vulcanoclastici del pliocene-pleistocene; 3) depositi sedimentari del meso-cenozoico; 4) principali faglie sepolte; 5) faglie trascorrenti; 6) faglie normali; 7) sovrascorrimenti principali. il riquadro in nero indica l’area in studio (modificato da milli et al., 2008). the argali (ovis ammon antiqua) from the magliana area (rome) 115 fig. 2 incomplete skull of ovis ammon antiqua from the magliana area; a) frontal view; b) posterior view; c) lateral view. cranio incompleto di ovis ammon antiqua della magliana; a) norma frontale; b) norma posteriore; c) norma laterale. the content of li and k (with its vicariant elements rb, tl and pb) testifies to the presence of leucite in the analysed sediment. moreover ba, sr and rb are related to pyrossens, while u, cr and w derive from volcanic minerals in general. since the analysis of trace elements confirms the presence of volcanic minerals, such as micas, pyrossen and leucite at various stages of alteration in analcime or clay minerals, the skull of ovis ammon antiqua found at la magliana is at least younger than the beginning of the volcanic activity in the study area, even though we cannot confirm whether these particles are related to the “pozzolane grigie” or not. however, considering the macroscopic similarity between the “pozzolane grigie” and the “tufo pisolitico” (the first pyroclastic flow unit of the alban hills volcanism, de rita et al., 1988; marra & rosa, 1995), locally cropping out in the study area, the hypothesis that elements such as li and k originated from the alteration of these older products cannot be ruled out. the 40ar/39ar age of leucite in “tufo pisolitico” sampled at la magliana is about 561 ± 1 ka (karner & renne, 1998; karner et al., 2001) and the deposition of this volcanic horizon is related to mis 14 (karner & marra, 1998). all in all, we could assume that the argali skull might have been buried during or after the beginning of the “tufo pisolitico” deposition. accordingly, since: the sequence boundary between the pg3 and pg4 is an unconformity surface related to a lowstand phase during mis 14 (milli, 1997); the deposits of pg4 sequence widely outcrops at the top of the hills in the fosso della magliana area, while outcrops of pg5 sequence are scantily or not present and portis considered the skull of ovis ammon antiqua as found at la magliana in levels whose description is consistent with the lacustrine-lagoonal deposits of the tst/hst of the pg4 sequence, we could hypothesize that the study specimen settled in a period covering the ending of mis 14 and the beginning of mis 13. accordingly, the incomplete skull of ovis ammon antiqua might tentatively be ascribed to fontana ranuccio fu as the argali from visogliano, though the latter could be slightly younger (see below). on the other hand, owing to the doubt about the actual location of the finding, and taking into account the age of the oldest volcanic deposits in the area, included in the “santa cecilia formation” (karner & renne, 1998; karner et al., 2001; funiciello & giordano, 2008), we cannot exclude that the argali skull could be older (isernia fu), if recovered from deposits of pg3 sequence. 3. ovis ammon antiqua from magliana in a western european context: comparisons and remarks the argali is mainly recorded in europe during the middle pleistocene, geographically ranging from georgia to portugal (crégut-bonnoure, 2005), though scanty remains close to the species have been reported in the early peistocene local faunal assemblages of sénèze, slivnitsa and apollonia i (kostopoulos, 1996; spassov & crégut-bonnoure, 1999; crégut-bonnoure, 2007). its occurrence in the late pleistocene (koudaro i, sakajia, ortvala, azykh, taglar and mezmaiskaya) needs to be confirmed (crégut-bonnoure, 2005; 2007). the type of the species «ovis antiqua», found at pont-du-château and described by pommerol in 1880 (pommerol, 1880), might be regarded as penecontemporaneous with the argali specimens from la caune de l’arago (crégut-bonnoure, 2007). it comes from levels whose faunal content might be tentatively related to the so-called g3 western mediterranean faunal complex, to which early middle pleistocene lfas referable to french mn 23, spanish mmq3 (in part) ‘‘zones’’, and italian fontana ranuccio fu (late galerian) have been ascribed (see palombo, 2010 and references therein). the richest samples of ovis ammon antiqua come from la caune de l’arago (monchot, 1998; rivals, 2004), where 12,771 remains were retrieved from levels of the middle complex (mis 14-12) (moigne et al., 2006; rivals et al., 2008 and references therein). the specimens found in the two levels don’t show remarkable morphological and biometrical differences. the morphology of the skull and teeth of the specimens found at la caune de l’arago is consistent with the type of the species (rivals, 2004; moigne et al., 2006). the incomplete skull from la magliana (fig. 2) shows some peculiarities in comparison with the remains of ovis ammon antiqua found at la caune de l’arago (fig. 3) and with the type of the species retrieved at pont-du-château (fig. 4). r. rozzi, m.r. palombo & m. barbieri 116 fig. 3 skull of ovis ammon antiqua from la caune de l’arago; a) lateral view; b) posterior view (modified after rivals, 2004). cranio di ovis ammon antiqua da la caune de l’arago; a) norma laterale; b) norma posteriore (modificato da rivals, 2004). in the posterior view, the italian skull differs from the french ones in having squat, less twisted and larger horn-cores relative to the braincase (figs. 2b, 3b, 4b). moreover, the occipital bone of the specimen found at la magliana shows a squared outline, as the specimens from la caune de l’arago, but clearly differing from the type specimen characterized by a rounded and compressed shape of this region. since the dimensions of the remains coming from pont-duchâteau (pommerol, 1880) and la caune de l’arago are rather similar (rivals, 2004; moigne et al., 2006), the differences in the morphology of the horn-cores and of the occipital area cannot be explained in terms of sexual dimorphism, but could be related to intraspecific variability. in the lateral view, a more pronounced dorsoventral curvature and a minor constriction of the horncores characterize the italian skull (figs. 2c, 3a, 4c). since different morphotypes, in particular in the horncores, have been recognized in the extant argali and mouflon (fischer et al.,1983), these differences, as well, could be related to intraspecific variability. the differences in morphology are confirmed by biometrical data, indicating that the occipital region is slightly more vertically elongated in the specimen from la magliana than in the argali from la caune de l’arago. despite such differences, the skull found at la magliana shares a broad similarity in shape and proportions with the specimens used for comparison. in particular, the dimensions of the horn-cores fit well within the range of variability of the larger specimens, likely males, found at la caune de l’arago (monchot, 1998; rivals, 2004) (fig. 5). 4. concluding remarks the results obtained on the one hand show that the morphology and biometry of ovis ammon antiqua skull from la magliana fall within the range of variability of the males found at the french site of la caune de l’arago (corbières massif) in the stratigraphic unit cm1 (about 570 to 530 ka), cm2 (about 530 to 480 ka), and cm3 (about 480 to 400 ka) of the middle complex cm, whose faunas have been correlated with the italian local faunal assemblages (lfas) of isernia (middle galerian) (cm1), and fontana ranuccio (late galerian) (cm2 and cm3) (de lumley et al., 1984; moigne et al., 2006); on the other hand they confirm that the la magliana specimen is younger than the beginning of the volcanic activity in the area, but they do not enable us to unequivocally determine its stratigraphical position. assuming that ovis ammon antiqua was found in the pg4 deposits, this means that the argali was present during the late galerian not only in the north eastern corner of the italian peninsula (visogliano, abbazzi et al., 2000), but also in central italy, albeit in different climate and environmental conditions. the extant argali sheep inhabits mountainous areas in central asia at elevations above 1000 m, though fig. 4 type of the species <<ovis antiqua>> from the pommerol collection; a) frontal view; b) posterior view; c) lateral view (modified after crégut-bonnoure e. & guérin c., 1996). tipo della specie <<ovis antiqua>> dalla collezione di pommerol; a) norma frontale; b) norma posteriore; c) norma laterale (modificato da crégut-bonnoure e. & guérin c., 1996). the argali (ovis ammon antiqua) from the magliana area (rome) 117 fig. 5 scatter diagram comparing the transverse diameter (td) and the antero-posterior diameter (apd) of the horn-cores of both extant and extinct species of the genus ovis. the grey point marked with a star corresponds to ovis ammon antiqua from la magliana. measurements from rivals, 2004, except for the studied specimen. grafico a dispersione che mette in relazione il diametro trasverso (dt) ed il diametro antero-posteriore (dap) dei cavicchi ossei di specie sia fossili che attuali del genere ovis. il punto grigio circondato da una stella corrisponde all’esemplare di ovis ammon antiqua della magliana. misure tratte da rivals, 2004 e originali per l’esemplare in studio. they are not good mountain-dwellers, and prefer slightly sloping areas and open temperate-cold environments dominated by grasses, with very few trees present on the landscape (clark, 1964; shackleton & shank, 1984; geist, 1991). the preferred habitat of the european fossil subspecies would not have been so different, except for elevation, as inferred, for instance, by the environmental context of both late galerian sites of visogliano (northeastern italy) (cattani et al., 1991; abbazzi et al., 2000; arobba et al., 2004; falgueres et al., 2008) and la caune de l’arago (france) (falgueres et al., 2004; moigne et al., 2006; rivals et al., 2008 and references therein). at visogliano, argali remains come from deposits of the middle and upper part (layers 39-11) of shelter a, which were deposited during cold climatic phases, while the species is absent in the lower levels (39-45), deposited during a warm and moist period (arobba et al., 2004). according to falgueres et al., 2008, available data might indicate that the lowest levels possibly deposited during the marine isotope stage mis 13 or that the ‘‘cold’’ levels (levels 11-39) could be correlated with mis 12 and 10, while mis 11 would be largely eroded, contrary to what has already been suggested by various authors (see e.e. abbazzi et al., 2000; arobba et al., 2004). the estimated ages of levels 38-24 range between 445 and 383 ka, suggesting that these layers were deposited shortly after the lowest ones, holding human remains, in spite of the change in climate conditions and faunal content, differentiating layers 45-40 and 39-24. whatever the age of the levels yielding o. ammon antiqua remains, they reasonably deposited during a climate worsening phase. accordingly, the argali was present in the north-eastern italy in quite cold and arid periods, when grasses expanded, forest reduced, and steppe taxa such as ochotona, citellus, microtus gregalis and equus were present, while more temperate species such as dama clactoniana, sus scrofa, macaca and crocidura declined or disappeared (abbazzi et al., 2000). at la caune de l’arago, the stratigraphical unit cm3, correlated with mis 12, shares with visogliano a few similarities in radiometric data and faunal assemblages (falgueres et al., 2004; 2008; moigne et al., 2006). in the faunal assemblage, o. ammon antiqua is present together with some open environment dwellers (e.g. equus, hemitragus, rupicapra, praeovibos, bison priscus) and “cold” species such as rangifer tarandus, but forest dwellers (e.g. lynx, felis silvestris) also occur. consistently, palynological data indicate a number of climatic fluctuations, with alternating phases of cold steppe and temperate forest (renault-miskovsky, 1980). conversely, deciduous forests were present during the deposition of the stratigraphical unit cm2, correlated with mis 13, while colder and drier conditions are documented at the time of the deposition of the stratigraphical unit cm1, correlated with mis 14, when trees were rare and arid steppe spread (renault-miskovsky, 1980). these data and, in particular, the persistence of o. ammon antiqua at la caune de l’arago during quite warm and moist phases, related to mis 13, seem to indicate that the ecological flexibility of the argali allow it to inhabit sparsely wooded and fairly humid environments. on the other hand, a spread of forests in the rome area is documented by the trees association (including broadleaved trees typical of the rainy colchic region) found in the so-called ‘‘tufi litoidi grigi’’, the ‘‘peperino’’ formation of via flaminia (rome) (follieri, 2010), which have been recently dated at around 528 ka by means of 40ar/39ar (karner et al., 2001). the presence of forests in the roman basin at the beginning of mis 13 raises further questions about the times of the presence of the argali in central italy. additional data are needed to clarify times of dispersal towards an extent of dispersion across the italian peninsula of ovis ammon antiqua, as well as the suitable environmental context allowing to its sporadic appearence. acknowledgments the authors are grateful to d. de rita and s. milli for their useful discussion about volcanic products and the geological setting of the magliana area, to mario barbieri for suggestions as to interpreting the geochemical data, and to l. di bella for the palaeontological analysis of the sediment filling the horn-cores. the authors thank the two anonymous reviewers for their comments to the manuscript. references abbazzi l., fanfani f., ferretti m. p., rook l., cattani l., masini f., mallegni f., negrino f., tozzi r. rozzi, m.r. palombo & m. barbieri 118 c. (2000) new human remains of archaic homo sapiens and lower palaeolithic industries from visogliano (duino aurisina, trieste, italy) journal of archaeological science, 27, pp. 1173-1186. arobba d., boscato p., boschian g., falguères ch., fasani l., peretto c., sala b., hohenstein u. t. & tozzi c. (2004) paleonvironmental analysis collegium antropologicum, 28, pp. 5-21. cattani l., cremaschi m., ferraris m. r., mallegni f., masini f., scola v., tozzi c. (1991) le gisement du pleistocene moyen de visogliano (trieste) : restes humains, industries, environnement l’anthropologie, 91, pp. 9-36. clark j. l. (1964) the great arc of the wild sheep university of oklahoma press, norman. crégut-bonnoure e. (2005) nouvelles données paléogéographiques et chronologiques sur les caprinae (mammalia, bovidae) du plio-pléistocène moyen et supérieur d’europe homenaje a jesús altuna, munibe (antropologia-arkeologia), san sebastian, 57, pp. 205-219. crégut-bonnoure e. (2007) apport des caprinae et antilopinae (mammalia, bovidae) à la biostratigraphie du pliocène terminal et du pléistocène d’europe quaternaire, 18, pp. 73-97. crégut-bonnoure e. & guérin c. (1996) famille des bovidae, in guérin c. & patou-mathis m. (editors), les grands mammifères plio-pléistocènes d’europe. masson, collection préhistoire, pp. 62-106. de rita d., funiciello r., parotto m. (1988) carta geologica del complesso vulcanico dei colli albani progetto finalizzato geodinamica, c.n.r., rome, italy. falguères ch., bahain j.-j., tozzi c., boschian g., dolo j.m., mercier n., valladas h., yokoyama y. (2008) esr/u-series chronology of the lower palaeolithic palaeoanthropological site of visogliano, trieste, italy quaternary geochronology, 4, pp. 390-398. falguères ch., yokoyama y., shen g., bischoff j.l., ku t.l., de lumley, h. (2004) new u-series dates at the caune de l’arago, france journal of archaeological science, 31, pp. 941-952. fischer m., schumann h.-g., lamster h. (1983) ansprechen des schalen wildes veb deutscher landwirtschaftsverlag, berlin, 144 p. follieri m. (2010) conifer extinction in quaternary italian records quaternary international, 225, pp. 37-43. funiciello r. & giordano g. (2008) note illustrative della carta geologica d’italia alla scala 1:50.000; foglio 374, roma progetto carg, firenze, italy. geist v. (1991) on the taxonomy of giant sheep (ovis ammon linnaeus, 1766) canadian journal of zoology, 69, pp. 706-723. karner d.b. & marra f. (1998) correlation of fluviodeltaic aggradational sections with glacial climate history: a revision of the classical pleistocene stratigraphy of rome geological society of america bulletin, 110, pp. 748-758. karner d.b. & renne p.r. (1998) 40ar/39ar geochronology of roman volcanic province tephra in the tiber river valley: age calibration of middle pleistocene sea-level changes geological society of america bulletin, 110, pp. 740-747. karner d.b., marra f., renne p.r. (2001) the history of monti sabatini and alban hills volcanoes: groundwork for assessing volcanic-tectonic hazards for rome journal of volcanology and geothermal research, 107, pp. 185-219. kostopoulos d.s. (1996) the plio-pleistocene artiodactyls of macedonia (greece) systematic, palaeoecology, biochronology, biostratigraphy phd thesis, aristotle university of thessaloniki, thessaloniki, 671 p. de lumley h., fournier a., park y. c., yokoyama y., demouy a. (1984) stratigraphie du remplissage pleistocene moyen de la caune de l’arago à tautavel. etude de huit carottages effectués de 1981 a 1983 l’anthropologie, 88, pp. 5-18. marra f. & rosa c. (1995) stratigrafia e assetto geologico dell’area romana, in accardi n., funiciello r., marra f. (editors), la geologia di roma. il centro storico. memorie descrittive della carta geologica d’italia, 50, pp. 49-118. maul l., masini f., abbazzi l., turner, a. (1998) the use of different morphometric dates for absolute age calibration of some south and middle european arvicolid populations palaeontographica italica, 85, pp. 111-151. milli s. (1997) depositional setting and high-frequency sequence stratigraphy of the middle-upper pleistocene to holocene deposits of the roman basin geologica romana, 33, pp. 99-136 milli s., moscatelli m., palombo m.r., parlagreco l. & paciucci m. (2008) incised valleys, their filling and mammal fossil record: a case study from middle-upper pleistocene deposits of the roman basin (latium, italy) geoacta, special publication, pp. 67-88. moigne a.-m., palombo m.r., belda v., heriech-briki j., kacimi s., lacombat f., de lumley m.-a., moutoussamy j., rivals f., quilès j., testu a. (2006) les faunes des grands mammifères de la caune de l’arago (tautavel) dans le cadre biochronologique des faunes du pléistocène moyen italien l’anthropologie, 110, pp. 788-831. monchot h. (1998) les petits bovidés de la caune de l’arago (tautavel, france): intéret biostratigraphique, archéozoologique et taphonomique quaternaire, 9, pp. 369-377. palombo m.r. (2010) a scenario of human dispersal in the northwestern mediterranean throughout the early to middle pleistocene quaternary international, 223-224, pp. 367-386. pommerol m. (1880) le mouflon quaternaire congrès de l’association française de l’avancement des sciences, 8e session, pp. 600-609. portis a. (1917) il rinvenimento di ovis antiqua pommerol in territorio di roma bollettino della società geologica italiana, 36, pp. 223-232. renault-miskovsky j. (1980) le paléoenvironnement de l’homme de tautavel (caune de l’arago, tautavel, pyrénées orientales): la faune et la flore en roussillon au pléistocène moyen comptesrendus de l’académie des sciences paris, 290, pp. 747-750. rivals f. (2004) les petits bovidés (caprini et rupicaprini) pléistocènes dans le bassin méditerranéen et le caucase. etúde paléontologique, bioestratithe argali (ovis ammon antiqua) from the magliana area (rome) 119 graphique, archéozoologique et paléoécologique british archaeological reports international series, 1327, pp. 1-252. rivals f,, ellen schulz, e., kaiser t.m. (2008) climate-related dietary diversity of the ungulate faunas from the middle pleistocene succession (ois 14-12) at the caune de l’arago (france). paleobiology, 34, pp. 117–127. shackleton d. m., shank c. c. (1984) a review of the social behavior of feral and wild sheep and goats journal of animal science, 58, pp. 500-509. spassov n. & crégut-bonnoure e. (1999) premières données sur les bovidés villafranchiens de bulgarie comptes rendus de l’academie des sciences, series iia, earth and planetary science, 328, pp. 493-498. ms. ricevuto il 25/05/2010 testo definitivo ricevuto il 8/10/2010 ms. received: may 25, 2010 final text received: october 8, 2010 amq abs gattiglio et al tepro 213-216.pub available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 213 216 multidisciplinary approach to reconstruct the geological quaternary evolution of the torrente traversola deformation zone (asti reliefs, nw italy) marco gattiglio, m. gabriella forno, mauro bonasera, cesare comina, alfredo doglione, franco gianotti, giandomenico fubelli dipartimento di scienze della terra, università di torino, torino, italy corresponding author: m.g. forno <gabriella.forno@unito.it> abstract: the results of geological and geophysical surveys performed in the asti reliefs along the torrente traversola deformation zone (ttdz), have been reported in this work. the outcropping “villafranchian ” succession shows local anomalies within this zone, consisting in sub-vertical geological contacts linked to faults, as well as bodies connected to gravitational reworking of sediments. this setting is due to the recent evolution of faults along the ttdz system, which is characterised by a main strike-slip movement. tectonic evolution has been clearly outlined by the combination of electric resistivity tomography and geological interpretation of the anomalies in the stratigraphic succession. keywords: “villafranchian” succession, asti reliefs, torrente traversola deformation zone, electric resistivity tomography, pliocene, quaternary 1. introduction research on the central piedmont hilly area (poirino plateau, asti reliefs and alessandria plateau) has been carried out in the last years, with the aim of reconstructing the stratigraphic pliocene and quaternary succession and its relations with the evolution of the main tectonic structures. in detail, the sediments outcropping in the asti reliefs belong to the “villafranchian” succession of the type-area comprising deltaic deposits (lower complex) and fluvial deposits (upper complex) (fig. 1a), which are separated by the cascina viarengo unconformity (carraro, 1996). the two complexes, resting on the shelf sandy deposits (asti sand of zanclean age), are referred to the piacenzian and calabrian respectively (dela pierre et al., 2003; forno et al., 2015). above the “villafranchian” sediments a widespread silty and locally gravelly fluvial cover of middle-upper pleistocene occurs, which is linked to po and tanaro rivers ancient courses. the whole sedimentary sequence is deformed by the asti syncline, which consists of a wide e-w regional -scale fold in the central hilly area (carraro et al., 1995) (fig. 1a). the transition between asti reliefs and poirino plateau corresponds to an evident regional scarp, that represents the morphological expression of the torrente traversola deformation zone (ttdz), as reported in the geological literature (carraro, 1996; gattiglio et al., 2015) (fig. 1a). this structure also dislocates the asti syncline axis that assumes a different location in the poirino plateau respect to the asti reliefs (fig. 1b). the ttdz belongs to the langhe seismic district, a region where no strong earthquake was recorded but a quite frequent microseismicity has been observed. about thirty earthquakes were recorded by ingv in the last decade between 1.0 to 4.1 ml. a multidisciplinary approach based on detailed field, geological, geomorphological and geophysical surveys were performed, to better define the ttdz significance and evaluate its seismic potential. 2. material and methods a detailed geological survey in the valmaggiore sector, developed along the ttdz fault system, was carried out (carraro, 1996; gattiglio et al., 2015) (fig. 1b). anomalies in the stratigraphic succession (soft sediment deformations and gravitational reworked bodies) as well as sub-vertical contacts, both probably connected to the evolutions of faults, were particularly investigated. a geomorphological analysis was also performed, regarding a possible connection between the river trend and the tectonic evolution of faults. an electric resistivity tomography (ert) was carried out along a survey line, where a sub-vertical geological contact has been identified, finalized to recognize and/or to confirm the presence of faults (fig. 2). the ert was executed by means of a syscal-pro tomograph (iris instruments) with 72 measuring electrodes at 2 m spacing. a wenner-schlumberger measuring sequence (with a total of 1247 measuring quadrupoles) was used in order to obtain a good compromise between both vertical and lateral resolution. acquired data were processed by the commercial inversion code res2dinv® (loke & barker, 1996). after preliminary data filtering a good convergence of the results has been obtained with rms error below 2 %. 3. results the most common sediments outcropping in the valmaggiore sector, texturally heterogeneous and very compact, are referred to the san martino unit https://doi.org/10.26382/aiqua.2018.aiquaconference (“villafranchian” lower complex) (fig. 2). they consist of predominantly planar bedded to massive clayey silt, that is typically grey, rich in scattered leaf and reed imprints, plant fragments, roots and pollen. the fine facies and fossils are usual in swamp environments where the mineral fraction and vegetal remains decanted in the water column. trough cross-bedded sand forms the fills of channel. the sandy texture, cross bedding and local vertebrate remains suggest a stream environment. the association of these two facies is typical of plain deltaic environment. specifically, the silt was deposited in coastal swamps, and the sand filled the deltaic distributary channels. the contact with the upper complex is marked by the cascina viarengo unconformity that represents the result of erosional phenomena that caused a progressive thickness reduction of the san martino unit towards the south. trough cross-bedded sediments with a component of minute gravel, referred to the cascina gherba unit (“villafranchian” upper complex), cover the previous unit. the gravelly-sandy texture and the absence of fossils suggest that they are associated to a fluvial channel environment. clayey silt forms the top of the “villafranchian” succession, referred to the maretto unit (“villafranchian” upper complex). it appears very weathered in its whole thickness (in consequence of several superimposed soils) and rich of carbonatic concretions. the silty-clayey texture and the strong weathering indicate that these sediments are associated to a continental fluvial plain in which the soils developed already during the sedimentation (forno et al., 2015). the sedimentary succession in the valmaggiore sector is dissected by many fractures striking from n350° to n10°, dipping towards the east and representing a fault system approximately characterised by n-s trend (fig. 3a). this system, only locally associated to soft sediment deformation, dislocates the whole sedimentary succession, involving both sediments of “villafranchian” lower and upper complexes. the geological evolution of this system occurred, therefore, in a long time spam, from a syn-sedimentary activity during the piacenzian to a post-sedimentary movement during the upper pleistocene. geological survey suggests that the western sector appears uplifted compared to the eastern one, evidencing an inverse component of movement. furthermore, the thickness of the san martino unit is greater in the eastern sector respect to the western one. the overall thickness change of these sediments (with values progressively increasing towards the north) suggests also a remarkable dextral strike-slip component for this fault. the geomorphological evidence also contributes to the tectonic reconstruction. the current watercourses essentially have n-s trend, different from their upper pleistocene configuration characterised, instead, by we main watercourses along the asti syncline axis. the current drainage network seems to be therefore driven by the n-s tectonic system, showing main stream flow (n-s) that superimposes a previous flow direction (w-e) (fig. 1b). a minor fault system showing n150° trend with an extensional component (lowering toward west) is also observed. it dislocates only part of “villafranchian” low complex, also creating small scarps se of case sossi. chaotic sediments, locally occurring in the lowered sector (asterisk in fig. 2), contain decimetric silty and sandy fragments characterised by various arrangement (fig. 214 fig. 1 a) simplified geological map of the piedmont hilly region with the location of the ttdz; b) aster global dem (nasa-miti, dec. 2009) showing the scarp between the poirino plateau and the asti reliefs. (1) asti syncline axis; (2) t. traversola deformation zone (ttdz); upper pleistocene ancient course of rivers: (3) tanaro, (4) po, (5) po and tanaro. the asterisk indicates the location of fig. 2 (from gattiglio et al., 2015). gattiglio m. et al 215 fig. 2 detailed geological map of the valmaggiore area, showing a n-s fault system referred to the ttdz. the asterisk indicates the reworked sediments of the san martino unit. fig. 3 a) n-s faults referred to the ttdz; b) chaotic sediments connected to reworking of the deltaic plain body (500 m south of case sossi). quaternary evolution of the torrente traversola deformation zone 3b). here trough cross-bedded sand connected to a filled channel also locally crops out, above the reworked body. the chaotic body is due to gravitational reworking phenomena of sediments as well as the location of the channel corresponds to the lowered sector. the n150° fault system is sealed by deltaic plain sediments (san martino unit), suggesting a syn-sedimentary tectonics. this geological reconstruction is also supported by the resulting resistivity distribution along the geophysical survey line (fig. 4). a marked sub-horizontal resistivity anomaly is observed along the e-w geophysical cross section in a surficial localized body approximately at progressive 52 m. this zone shows higher resistivity values (around 1000 ohm.m) with respect to the surrounding. this body is laterally interrupted by a subvertical band showing a minor resistivity anomaly approximately at progressive 36 m. the comparison between geological data (showing an isolated body formed by gravelly sand interrupted by a n-s fault system) and geophysical results suggests that these anomalies can be associated to cemented gravelly sand belonging to the cascina gherba unit, interrupted by a cemented sub-vertical band referred to the n-s fault system (fig. 4). the lower resistivity values observed (around 15 ohm.m) around this zone can be attributed to the silt of the san martino unit, with subordinate fine sand. the geophysical evidence supports therefore the geological reconstruction of a fault dislocating the stratigraphic continuity of sedimentary bodies. 4. discussion and conclusion the detailed geological survey allowed to observe that the stratigraphic succession is characterised by sub -vertical geological contacts as well sediments connected to gravitational reworking of the deltaic body. on the base of the geological and geomorphological evidences a fault of the ttdz has been detected around cascina volpiano. the comparison between geological and geophysical data also allows to confirm the presence and location of this fault. the electric resistivity tomography indicates the prosecution of the fault system in the shallow subsoil and the anomalous cementation of sediments along this system, already observed in other sectors. a strike-slip component of the n-s fault is evidenced by the thickness change of san martino unit, according to the main strike-slip evolution of the ttdz. this deformation zone also comprises n150° faults testifying syn-sedimentary tectonics. the tectonic evolution along the ttdz, dislocating both complexes of the “villafranchian” succession (referred to piacenzian and calabrian), took place in a long time interval and possibly is still active as suggested by the present microseismicity. references carraro f. (ed.) (1996) revisione del villafranchiano nell'area-tipo di villafranca d'asti. atti del convegno: "il significato del villafranchiano nella stratigrafia del plio-pleistocene" (peveragno (cn)villafranca d'asti (at), 20-24 giugno 1994). il quaternario, italian journal of quaternernary science, 9(1), 38-62. dela pierre f., piana f., fioraso g., boano p., bicchi e., forno m. g., violanti d., clari p., polino r., balestro g., d’atri a. (2003) foglio 157 “trino” della carta geologica d’italia alla scala 1: 50.000. apat, dipartimento difesa del suolo, roma. gattiglio m., forno m.g., comina c., doglione a., violanti d., barbero d. (2015) the involving of the pliocene-pleistocene succession in the t. traversola deformation zone (nw italy). alpine and mediterranean quaternary, 28(1), 59-70. forno m.g., gattiglio m., comina c., barbero d., bertini a., doglione a., irace a., gianotti f., martinetto e., mottura a., sala b. (2015) stratigraphic and tectonic notes on the villafranca d’asti type-area and castelnuovo don bosco sector (asti reliefs, piedmont). alpine and mediterranean quaternary, 28 (1), 5-27. loke m.h., barker r.d. (1996) rapid least-squares inversion of apparent resistivity pseudosections using a quasi-newton method. geophysical prospection, 44, 131-152. 216 fig. 4 resistivity distribution along the cascina volpiano geophysical survey line, with reported geological interpretation. gattiglio m. et al ms. received: may 9, 2018 final text received: may 23, 2018 available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), i iii preface quaternary: past, presente, and future 40 years of italian quaternary in an alpine-mediterranean perspective adele bertini 1 , maria rita palombo 2 1 dipartimento di scienze della terra, università di firenze, firenze, italy 2 cnr-igag, area della ricerca di roma 1, c/o dipartimento di scienze della terra, università di roma “sapienza”, roma, italy the aim of the 2018 aiqua (italian association for quaternary studies) annual congress (earth science department, florence university, 13-15 june) was three -folded: i) to provide an overview on the status of quaternary research in italy, focusing on the new lines of research, in particular those performed by early-career researchers; ii) to discuss the most intriguing and multifaceted aspects related to quaternary studies, also in the perspective of correct public outreach and effective responses to societal challenges; iii) to celebrate the anniversary of four significant events, which fall in 2018. i) in 1928, international union for quaternary research inqua was nominally founded during a congress devoted to celebrate the founding (1888) of the danish geological institute (general international conference, copenhagen 17-30 june 1928). during the plenary session on the second day of the conference (26 june 1928) it was unanimously accepted the proposal presented by prof. m. limanowski (university of vilnius in lithuania) for the establishment and organisation of the “association for investigations of the quaternary of europe”. it taken some years before the european association became a world organisation (inqua), devoted to promoting quaternary researches and collaborations among scientists around the world, and reached its current structure (porter, 2003; smalley, 2011). ii) 70 years ago, during the 18th international geological congress held in london in 1948, it was agreed to place the pliocene-pleistocene boundary “... at the horizon of the first indication of climatic deterioration in the italian neogene succession” (king & oakley, 1949). the italian stratigraphers provided an outstanding contribution in defining the plio-pleistocene boundary, first formally defined in the stratotype section at vrica (calabria, southern italy) (aguirre and pasini, 1985) and successively lowered, after decades of discussion and following the recommendation of the 2008 international geological congress (igc), to the global stratotype section and point (gssp) of the gelasian stage/age at monte san nicola (sicily, italy) (gibbard et al., 2010), to encompass the time during which earth's climate has been strongly influenced by bi-polar glaciation, while the gssp at vrica remained available as the base of the calabrian stage/age. iii) 40 years ago (19 june 1978) the italian association for quaternary studies (aiqua) was founded, with the objective of gathering scholars working in the various fields of research dealing with the quaternary, promoting quaternary study and knowledge in italy and elsewhere, and enhancing the quaternary cultural and environmental heritage. iv) 30 years ago, on january 1st, 1988, the aiqua journal "il quaternario italian journal of quaternary science” (since 2012, “alpine and mediterranean quaternary”) started to be published. since that time hundreds of papers were published spanning nearly all the main quaternary issues and disciplines, from geomorphology, to archaeology, geodynamics, climatology, palaeontology, volcanology, palaeobotany, palaeoanthrolpology, ichnology, among others. https://doi.org/10.26382/aiqua.2018.aiquaconference since the beginning of the last century, besides its relevance for defining the plio-pleistocene boundary italy has been, indeed, a key territory for the study (sometimes pioneering) of the most recent events in the history of our planet, whose synergetic dynamics led to the modern geographical, climatic, and biogeographical setting, and italian researchers have been undisputed protagonists in various dedicated scientific disciplines, contributing to deconstruct the complex quaternary scenarios. the outstanding role of italy in quaternary studies is related to the variety and the complex history of its territory that has to be analysed and deconstructed in the context of the geodynamic, climatic, palaeobiogeographical and environmental evolution of the mediterranean basin, as well as of the alpine orogenesis and related phenomena. the mediterranean region, in fact, is geologically young and active and represents a hotspot of biodiversity and endemisms that characterise a region particularly suitable for discussing the dynamics interaction of processes and events that have shaped the physical and biotical scenarios succeeding each other in the last 2.6 millions of years. the scientific program of the 2018 aiqua annual congress included five sessions (coastal and marine processes, human and biosphere, palaeoclimate, stratigraphy and chronology, terrestrial processes), devoted to discuss the focal issues (e.g. climate change and its effects on ecosystems, main terrestrial processes in the short, medium and long term, rising sea level, volcanic and seismic activity, dynamics of plant and animal communities in a perspective of conservation of biodiversity and cultural heritage, dynamics of human population in the pleistocene and impact that human activity had on ecosystems during the most recent quaternary period in an alpine-mediterranean perspective. in particular, the session coordinated by m. anzidei and g. mastronuzzi was devoted to analyse and discuss the coastal and marine processes, especially focusing on the past relative sea level rising as the effect of climate change, but looking at expected scenarios for the coming decades. during the session, 8 oral communications have been presented that dealt with a number of different topics, such as issues possibly deriving from the extensive use of models in the face of a few new direct observations and data collection, methods and geodatabase related to palaeo-sea level markers, morphodynamics and landscape changes of coastal areas, as well as more punctual methodological approaches such as the determination of the friction coefficient for estimating sea storm. the session human and biosphere, coordinated by d. magri and m. peresani, included 13 oral presentations presented by palaeontologists, palaeoecologists, archaeologists, and geochemists, who introduced and examined, also in an interdisciplinary perspective and by means of advanced methodological approaches, a number of noteworthy and intriguing issues, such as the effects of climate changes on organisms, factors behind palaeoenvironment and ecosystems evolution, mainly focusing on terrestrial domain, and palaeolithic hominin behaviour and human impact on holocene environments (including pollution in the so called anthropocene recent and present time). the climate and palaeoclimate session, coordinated by f. lirer and f. toti, was devoted to present records and expected changes, processes and models, highlighting the results of research on all the aspects of quaternary climate, discussing the usefulness of proxies, presenting data syntheses, methods for inferring past climate, modelling and simulation of palaeoclimatic models. in line with the session aim, the 13 oral communications included in the session deal with different issues including case studied on palaeoclimate changes and climate instability and variability in marine and terrestrial domains, within and outside the mediterranean basin, studies on multiproxies environmental evolutionary dynamics and palaeoenvironmental evolution in different terrestrial contexts, and results obtained by means of quantitative methodological approaches and modelling. a fundamental basis for the reconstruction of quaternary events is provided by data coming from researches in the field of stratigraphy and chronology. the 8 contributions to the stratigraphy and chronology session, coordinated by m. balini and a. negri present classic and new methods of stratigraphical investigation, new data useful for an integration into a multidisciplinary stratigraphy, and critical evaluations of some principles of stratigraphic classification and correlation, and principles to be adopted in biostratigraphy and biochronology, as well as the criteria behind the database of terrestrial quaternary stratigraphical sites of europe currently under construction by an international teams of researchers working in the different quaternary disciplinary fields. the terrestrial processes session, coordinated by m. di vito, e. falcucci and p. mozzi, was planned to address the multiple and complex aspects and phenomena that regulate and constrain the history of continental environments, from tectonics to volcanoes, from extreme climatic events to earthquakes. following the session aim, the 13 oral communications addressed different themes even highlighting the role of quaternary research in the analysis of factors regulating environmental evolution and in the study and assessment of past, recent and present geological hazard. results presented by some contributions underlined the importance of multidisciplinary approaches to deconstruct complex quaternary geological events. the 2018 aiqua congress held in florence contributed to present the state-of-the-art and the diversity within the field of quaternary study, the most advanced researches on climate and landscape changes, marine and terrestrial processes, and ecosystems dynamics, highlighting the contribution of young researches in promoting the comparison and enhancing the analysis of the different quaternary evolutionary scenarios. deci ii bertini a., palombo m.r. iii phering the complex network of mechanisms leading to the present geological setting and biodiversity status is, likewise, of crucial relevance to understand the actual meaning of the processes acting today, and to plan appropriate actions for biodiversity conservation in view of the ongoing climate warming, correct public outreaches and effective responses to societal challenges, stretching our imagination beyond the present, and collects insights into the earth’s future scenario through a lesson from the past. references aguirre e., pasini g. (1985) the pliocene-pleistocene boundary. episodes, 8 (2), 116-120. gibbard p.l., head m.j., walker m.j., subcommission on quaternary stratigraphy (2010) formal ratification of the quaternary system/period and the pleistocene series/epoch with a base at 2.58 ma. journal of quaternary science, 25(2), 96-102. king w. b. r., oakley k. p. (1949) definition the pliocene-pleistocene boundary. nature, 163, 186187. porter s.c. (2003) inqua congresses: a 75th anniversary review. 16th (reno) inqua congress program with abstracts 8-9 (isbn 0-945920-512). available on line at www.inqua2003.dri.edu/ inqua03_program_p1-15.pdf smalley i. (2011) a history of inqua the international union for quaternary research. available on line at https://www.inqua.org/about/history beug h.j. (2015) leitfaden der pollenbestimmung für mitteleuropa und angrenzende gebiete. verlag dr. friedrich pfeil, munchen. preface: quaternary, past, present, future iv amq 31(1) 59-73 didonato et al proofcopy available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 31 (1), 2018, 59 73 palaeoenvironmental reconstructions through compositional data analysis valentino di donato1, josep antoni martín-fernández 2, marc comas-cufí 2, joanna jamka1 1 dipartimento di scienze della terra, dell’ambiente e delle risorse, università degli studi di napoli “federico ii”, naples, italy. 2 departament d’informàtica, matemàtica aplicada i estadística, universitat de girona, girona, spain. corresponding author: v. di donato <valedido@unina.it> abstract: the modern analogue technique has been accordingly revised with compositional data analysis framework. the method adopts the aitchison distance, obtained from isometric log-ratio coordinates of relative abundances, as a natural measure of similarity among assemblages. the number of analogues from which obtain the estimates was determined through leave-oneout verification of modern assemblages. mean distances and local outlier factor are considered to evaluate the quality of palaeoestimates. the method has been tested on atlantic ocean and mediterranean planktonic foraminiferal assemblages to reconstruct past sea surface temperatures (sst). in comparison with previous planktonic foraminiferal based reconstructions, the portugal offshore sst record for the last 210 ka shows a higher coherence with other paleoclimate proxies (i.e. the stable isotope and alkenone records). in comparison with raw data analysis, coda-mat yields lower estimates of the western mediterranean last glacial period sst. keywords: modern analogue technique, aitchison distance, sea surface temperatures supplementary appendices only online at http://amq.aiqua.it 1. introduction quantitative estimation of past environmental parameters is one of the most challenging engagements of palaeoclimatical and palaeoecological investigations. in palaeoceanographical studies quantitative palaeoclimatic reconstructions can be attained by means of geochemical methods, such as the analysis of long chain alkenones (brassel et al., 1986) and the mg/ca ratio in foraminifera (elderfield & ganssen, 2000), or more strictly paleontological methods based of statistical analysis of census counts of assemblages. these methods, known as transfer function methods, have been introduced to provide quantitative estimates from counts of fossils, including regression-based methods (imbrie & kipp, 1971), modern analogue techniques (mat) (hutson, 1979; pflaumann et al., 1996; waelbroeck et al., 1998) and artificial neural networks (malmgren et al., 2001). the starting point of these methods is a modern dataset usually consisting of counts of modern assemblages and measured environmental parameters. in this paper we focus on the mat which compares fossil assemblages with modern ones using a distance measure or a similarity coefficient. the palaeoenvironmental estimates are obtained from the environmental parameters measured at the location of the most similar modern assemblages. for each fossil samples the nearest modern ones are found by adopting an appropriate distance (d). then, the palaeoestimate p̂ for a fossil is represented by the mean of the environmental parameters pi measured at the geographical location of the h modern analogues: where h represents the number of analogues. following hutson (1979) and pfaumann et al. (1996), the mean can be weighted on the inverse of the distance (1/d(i)), so as increase the influence of the closer analogues on the palaeoestimate: ( ) ( ) 1 ( ) 1 (1/ ) ˆ 1 (1/ ) h i ii h i i d p p d = = ⋅ =   the assessment of the goodness of the method is usually carried out through cross-validation in the reference modern dataset. following the discussion along the works telford & birks (2009, 2011) and guiot & de vernal (2011a, 2011b), we assume that in mat the spatial structure of data has relatively low effect on the calculation of prediction errors. in consequence, in this work we assume no effect of spatial autocorrelation. mat mostly differ for the distance measures or similarity indexes used, among which the cosine-theta (hutson, 1979), the scalar product of the normalized https://doi.org/10.26382/amq.2018.05 60 di donato v. et al. assemblages vectors (pflaumann et al., 1996), squared chord distance (waelbroeck et al., 1998) and the euclidean distance on the logarithm of the species relative abundances in permil (guiot & de vernal, 2011a). the information in a modern and a fossil assemblage is the relative abundance or percentages of species, i.e., they can be considered as compositional data (coda) (aitchison, 1986). that is, the information contained in a vector of counts x is the same as in k·x, for any real scalar k>0, property known as scale invariance (aitchison, 1986). that is, any observation x is a member of an equivalence class (barceló-vidal & martínfernández, 2016). this type of data is common in earth sciences when the constituents and compounds are described in terms their concentration (e.g., buccianti et al., 2006). as with some of the cluster analysis techniques, despite it is also possible to experiment with different distances, we follow everitt et al. (2011, p. 69) recommendation “…the choice of measure will be guided largely by the type of variables being used and the intuition of the investigator”. in the particular case of coda the aitchison distance has been proved to be an appropriate measure for the geometry of the sample space (aitchison et al., 2000). palarea-albaladejo et al. (2012) present a summary of the properties, advantages and difficulties of several different measures when they are used for coda. the approach proposed on this paper has the aim to develop a mat in a coherent fashion with the nature of the data, hereafter the coda-mat. in the following section, the basic elements of the log-ratio methodology to coda are introduced and the coda-mat is described. next the method is tested, and its results illustrated using different assemblage datasets. finally, section 4 presents some conclusions and final remarks. 2. the coda-mat coda refers to vectors of positive components showing the relative weight of a set of parts in a total. nowadays, there is a general agreement that applying the standard statistical methods to coda may yield misleading results (pawlowsky-glahn et al., 2015). the logratio methodology proposed by aitchison (1986) represents a powerful set of methods and techniques to apply to coda. during last decades, numerous innovative ideas and strategies to coda were presented at the four codawork meetings (e.g., martín-fernández & thióhenestrosa, 2016a) and collected in special publications (e.g., martín-fernández & thió-henestrosa, 2016b). the approach adopted in this paper follows the principle of working on coordinates (mateu-figueras et al. 2011), that is, the standard statistical analysis is conveniently performed after choosing orthonormal log-ratio coordinates. in particular, we expressed each d-vector x=(x1, . . . , xd) of percentages of species as a (d-1)-dimensional real vector y=(y1, . . . , yd-1) of isometric log-ratio coordinates (y =ilr(x)) (egozcue et al., 2003) (see appendix 1 for definitions and details). to develop the coda-mat, the following points were considered: 1) pre-processing techniques; 2) choice of the distance measure; 3) number of analogues. 2.1. data pre-processing: subcomposition, amalgamation and zero replacement modern assemblages datasets often include a large number of zeros. as an example, planktonic foraminifera coretop datasets include zeros which are partly related to the broadly latitudinal distribution of most species, partly to the fact that there are several rare species whose abundance is often below the detection limit. the zero values present in the data require a pre-processing because the log-ratio methodology needs the data to be strictly positive (aitchison, 1986). to reduce the number of zero values to be replaced, rarer species can be excluded from the assemblages, by considering a subcomposition of the original assemblages (aitchison, 1986). moreover, it is possible to amalgamate species characterised by similar ecological requirements (aitchison, 1986). the choice of a limited numbers of species is motivated, as pointed out by buccianti & esposito (2004), by the necessity to reduce the zero substitutions needed by the log ratio transformations, and to avoid, as much as possible, the generation of extreme clusters of points, corresponding to small values (tauber, 1999). as pointed out by kucera et al. (2005) the main problem with abundances of rare species is the inevitably low signal to noise ratio. thus, amalgamation should not involve a reduction in the accuracy of results. about this, it is also worth recalling the subcompositional dominance property of an appropriate distance (palarea-albaladejo et al., 2012): distances between observations obtained from subcompositions, are less to equal to those obtained from full compositions. to manage the zeros occurring in the data, the first step of the analysis is the conversion of species vector of counts c, both for the fossil and modern data, into relative abundance compositional vectors x. if it can be assumed that zero values correspond to count zero, indicating that the component is absent by a sample size effect, it is possible to replace them by a suitable small value (martín-fernández et al., 2015). to do that, we adopted a mixed bayesian-multiplicative estimation approach, which is recommended when the compositional data arise from counts (martín-fernández et al., 2015). this treatment consists on a bayesian estimation of the zero percentages combined with a multiplicative readjustment (martín-fernández et al., 2003) of the non-zero values (see appendix 1). after the zero replacement, the ilr-coordinates’ vector y for the fossil and modern data are obtained. thus, fossil assemblages are represented by its ilrcoordinates, whereas the modern database is consisting of ilr-coordinates together with the environmental parameters measured at each location (at sea surface for planktonic assemblages coretops). 2.2 distance measure the ilr-coordinates are isometric, i.e., an isometry is established between x and its real vector y. hence, distances in the sample space of coda (the simplex s d) are associated with distances in rd-1. this property has important consequences for our aims, since distances in 61 palaeoenvironmental reconstructions through coda where n is the number of modern samples, p represents the vector of k measured environmental parameters, and p̂ the corresponding vector of estimated values. this approach is equivalent to analyse the mean of the norm of the residual rows (difference between measured and estimated parameters). the best result of msd is obtained when msd=0, i.e, all the estimates are equal to the measured values. in consequence, we select as optimal number of analogues the number that produces the minimal msd value. msd index is the multivariate generalization of the mean of squared errors (mse), applied when only one parameter is evaluated. the square root of mse is the root mean square error of prediction (rmsep), a quality index commonly calculated as a measure of the predictive abilities of the training set (wallach & goffmet, 1989; birks, 1995). the multivariate approach should be applied when there is a set of parameters defining the palaeoclimate, as is usually done in pollen analysis, from which several variables are estimated (i.e. temperature, seasonal or annual precipitation, potential evapo-traspiration). in such a case, the environmental parameters may be normalized before the computation of msd to avoid dominance effects induced by the different measurement units adopted. using the standard pearson correlation index, we can calculate a measure for k environmental parameters. this procedure calculates the pearson correlation coefficient r between a measured environmental parameter p and its estimates p̂ for all the modern analogues. a perfect quality of the estimations will produce a pearson correlation equal to 1. in a multivariate approach, when one deal with a vector p of measured environmental parameters (k parameters) and the corresponding vector of estimation p̂ , an index r is defined by ˆ( ) ( ) 1 (3) k p j p j j r r k = = where p(j) and p̂(j) respectively represents the jth parameter. in this case, the best value of r corresponds to 1. in consequence, the number of analogues that provides the maximum value of r is selected as optimal. it can be noted that the pearson correlation coefficient r is used as a similarity index between a measured and an estimated parameter. however, the results with this index could be misleading in some scenarios. for example, when the estimates are closely proportional to the measured values this index will also show a reasonable value (close to one), although the estimations are lowquality estimations because they are systematically biased. by combining r index with msd index, one completes the information about the quality and avoid these undesirable situations because msd index measures the goodness of the estimates across the samples 2.4. application on fossil assemblages the above-described leave-one-out evaluation provides the basis for the application of coda-mat on fossil assemblages, as best performing number of analogues for the modern conditions was determined by means of msd and r indexes. in a second step, it can be evaluated if this optimal number of analogues can be adopted to perform palaeoestimates from fossil assemblages. as in the ram method (waelbroeck et al., 1998), the number of analogues may be evaluated for each assemblage, by looking for “jumps”, i.e. increases in distance larger than a fraction of the last modern analogue selected. the number of analogues may be also reduced to obtain “oceanographically coherent” anathe simplex are translated into ordinary ones in the space of coordinates. thus, the aitchison distance (da) between two compositional vectors x, x* ∈ s d (aitchison, 2000) is equal to the euclidean distance (de) between their ilr-coordinates vectors y, y* ∈ r d-1, i.e., da(x, x*)=de(y, y*) (palarea-albaladejo et al., 2012). the aitchison distance meets the requirements of scale invariance, perturbation invariance and subcompositional dominance that are needed to achieve a meaningful statistical analysis of coda (palarea-albaladejo et al., 2012). an alternative distance measure that also meets these requirements is the mahalanobis distance on ilrcoordinates (palarea-albaladejo et al., 2012). on the other hand, the distances related to angular measures do not have a compositional coherent behaviour (palarea-albaladejo et al., 2012). this narrows it down to just euclidean or mahalanobis distance on ilrcoordinates the metrics that can be adopted in the coda-mat. 2.3. how many analogues? in theory, a palaeoestimate for a fossil sample may be obtained from a single very close modern analogue. however, the application on a too restricted number of modern analogues increases the risk of a bad estimate due to presence of anomalous samples in the modern dataset (i.e. arising from a decoupling of assemblage from the underlying surface conditions, or to taphonomic processes). in consequence, in the application of mat is essential to determine the optimal number of analogues from which the palaeoestimates are obtained. in the coda-mat this subject is handled by first one evaluating which number of analogues performs better in the modern conditions, by means of sensitivity analysis of leave-one-out cross-validation method (ter braak & juggins, 1993; barrows & juggins, 2005). once this number is determined, it is also adopted for palaeoestimates of all fossil assemblages. the sensitivity analysis to define the optimal number of analogues is based on numerical indices. indeed, once the environmental estimates are obtained for all the modern samples these are compared with the corresponding measured values, by computing two indices: the pearson correlation coefficient and the mean squared distances (msd) (e.g., martín-fernández et al., 2003). the msd is a multivariate index of quality of the estimates of k environmental parameters defined as: ( ) ( ) 22 1 ˆ( ), ( ) 2 n e i d i i msd n ==  p p logues (in the case of marine assemblages such as planktonic foraminifera see section 3.2) or to achieve coherence of the vegetational context of the analogues (in the case of continental proxies such as pollens). 2.4.1. no-analogue conditions, outliers and atypicality index. probably the most important difficulty of any proxybased reconstruction is represented by the no-analogue problem, occurring when the palaeoenvironmental conditions represented in the fossil assemblages do not have a correspondence in modern environments. more in general, it is important to define quality indexes of the palaeoestimates. the most obvious ones are represented by the average distance from the fossil assemblages to its nearest modern analogues and by the standard deviation of associated to the estimates. large mean distances and high standard deviation (often associated with oceanographical incoherence) likely indicate bad estimates. overpeck et al. (1985) indicated threshold values to be adopted with squared chord distance. in the coda-mat the problem of detecting noanalogue conditions is faced by first considering the atypicality index and outlier detection for coda sets. in a broad sense, atypicality index (e.g., aitchison, 1986) represents the probability of a more typical composition (or with a smaller mahalanobis distance, from the centre of the dataset) than the observed one. in coda-mat, atypicality index is first computed for each modern sample using mahalanobis distances, to determine critical values of distance for which a sample can be considered a potential outlier. after that, atypicality can be computed for each fossil assemblage to test the hypothesis of a significant difference respect to the population of modern ones. a significant difference may highlight no-analogue conditions. note that, in coda-mat, this index is based on the mahalanobis distance applied to ilr real vectors. this strategy is also in the basis of the robust methods to outlier detection for coda sets (filzmoser & hron, 2008) that are freely available in the r packages mvoutlier and robcompositions (r development core team, 2011). robust methods to identify multivariate outliers are based on the robust estimation of the covariance structure (e.g., peña & prieto, 2001). in our work, the estimated ilr covariance structure was used to assign a robust mahalanobis distance to each fossil assemblage indicating how far the sample is from the centre of the modern data cloud. a second approach to outlier detection has been developed by computing the local outlier factor (lof) (breunig et al., 2000) of assemblages. this index is based on a k-distance neighbourhood approach and assigns to each object the degree of being an outlier by determining how isolated the object is with respect to the surrounding neighbourhood. values much larger than 1 are associated to suspect local outliers. as done for the atypicality, the lof has been determined on ilr real vectors. the computations were replicated with increasing k values, which yielded quite stable results. the following results are based on a k=10. the relationship between a fossil sample and modern population can be approximately displayed in few dimensions by means of relative variation biplots (rvb) in which it is also possible to include fossil data as supplementary elements (daunis-i-estadella et al., 2011). in this way it is possible to easily visualize the space distribution of fossil samples and their modern counterparts. this may be useful to verify if a fossil sample is located within or at the margin of the surrounding closest modern analogues (see section 3.2). matlab routines to obtain rvb and perform the coda-mat are provided as supplementary materials. 2.4.2. evaluation of errors of estimates in relation to hyperspheres radius this approach provides for each sample an auxiliary tool for evaluating the reliability of the obtained estimates. for each modern sample, the maximum value of the module of the errors of the estimates is computed within hyperspheres with increasing radii centred on the sample itself. the obtained information is applied to fossil assemblages by considering them as laying at the border of h hyperspheres, each centred on one of the h closest analogues. the highest value of the maximum errors associated to these hyperspheres is recorded as potential estimate error, as a measure of the reliability of the obtained estimates for the fossil assemblages. confident estimates are obtained when a fossil assemblage is included within the radius of modern assemblages for which errors and standard deviation of the estimates are low. on the contrary, high values suggest considering with caution the reconstructed values or, at the limit, to discard these estimates if the potential error exceeds acceptable values. 62 fig. 1 location of modern planktonic foraminifera coretop samples adopted for application of coda-mat. drawn with ocean data view software (schlitzer, 2018). di donato v. et al. 3. testing the method the performance of coda-mat in the modern conditions was tested on planktonic foraminifera with a modern dataset consisting of 1252 atlantic and mediterranean coretop assemblages determined on the >150 μm size fraction (prell et al., 1999; hayes et al., 2004; kucera et al., 2004) (figure 1). additional mediterranean sea coretop assemblages were added from available literature datasets and unpublished data. the oceanographical data, consisting of mean annual, caloric summer and caloric winter sst refer to antonov et al. (2010) and locarnini et al. (2010). the sst values at coretops location were computed by means of ocean data view 4.7.10 (schlitzer, 2018). following kucera et al. (2005), oceanographical data are related to a depth of 10 m. about the modern dataset, it should be noted that the adopted zero substitution approach can't be directly applied to literature data when the planktonic foraminifera assemblages are reported as percentages without the total of counted specimens. although not an ideal solution (the obvious alternative being to exclude these samples), in few cases the percentages data included in the modern dataset were “reconverted” into counts by assigning a total of 300 specimens to the 63 fig. 2 relative variation biplot of planktonic foraminiferal assemblages included in the modern dataset (19 taxonomical groups). samples are grouped according to their latitude. fig. 3 sensitivity analysis of leave-one-out verification in relation to the number of analogs adopted for the coda-mat estimate of the modern measured seasonal sst. a) msd index; b) r index; c) mean std of estimates. black: annual sst; red: summer sst; blue: winter sst. solid line: ilr-euclidean (aitchison) distance; dashed lines: ilr-mahalanobis distance. tab. 1 leave-one-out estimated msd index, r index and mean std of estimates (6 analogs) palaeoenvironmental reconstructions through coda samples. the adopted modern planktonic foraminiferal assemblage dataset consists of 26 species. with the approach described in section 2.1 two datasets were generated, consisting of respectively 19 and 15 taxonomical groups (see appendix 2). the rvb of the planktonic foraminifera assemblages included in the modern dataset is shown in figure 2. the first two axes accounts for about 63% of total variability (71% if a third axis is added). the pattern of the links connecting column points highlights the close relationship (i.e. short links) among low latitude taxa such as globigerinoides ruber, globogerinoides sacculifer and globorotalia menardii-tumida, all of which are located on the positive side of axis 1. on the contrary the polar neobloboquadrina pachyderma left coiled is characterised by a strong log-ratio variability respect to most of the taxa, except for turborotalita quinqueloba. the location of the samples points in the rvb highlights the well-known broad latitudinal distribution of assemblages. 3.1. leave-one-out verification the leave-one-out verification (see par. 2.4.1) was carried out on the 15-parts dataset by computing a sensitivity analysis of msd and r indexes in relation to the number of analogues (h). both aitchison and log-ratio mahalanobis distances were considered. in consideration of the high correlation between annual and seasonal sst, the msd and r indexes were only tested with a univariate approach. for this sensitivity analysis a number of analogues h in (3) varying from 1 to 30 was considered to obtain the best value of the indexes. for each value of h (from 1 to 30) the estimates of the environmental parameter of each modern data sample were calculated using a leave-one-out procedure. as shown in figure 3, lower msd and higher r values were obtained with 6 to 10 analogues, both for unweighted estimates and estimates weighted on the inverse of the aitchison distance. as expected, the weighted estimates were characterised by lower msd values and higher r indexes, with peak values for annual sst estimates of 0.993. the annual sst r indexes are higher than seasonal ones. moreover, it can be noted, for both r and msd indexes, a rather flat response to the increase in the number of analogues (figure 3). although comparable results are obtained from 6 to 10 analogues, the progressive increase in the standard deviation of estimates detected for increasing number of analogues, suggests adopting 6 analogues for the estimates. figure 4 and table 1 summarise the relationships between measured seasonal sst and its estimates obtained under these conditions. the maximum mean aitchison distance between a sample and its closest neighbourhood is about 4.7. the leave-one-out verification was also tested with the mahalanobis distance on ilr data. however, in comparison with aitchison distance, the msd and standard deviation values are always higher, and the r indexes lower (figure 2). overall, the sensitivity analysis indicates that the aitchison distance is more performing than the log-ratio mahalanobis distance. we replicated the sensitivity analysis by testing the 19 parts dataset. the results are quite similar (the correlation coefficient between the annual sst obtained with 19 and 15 parts is 0.999) and are not reported here. 3.2. spatial and geographical relationships. as discussed above, on the whole dataset, the best leave-one out estimates are obtained with 6 to 10 analogues. further, the leave-one-out verification was extended to include the whole analogues, by also considering the geographical location of the analogues. in general, the increase in the number of analogues corresponds to an increase in the standard deviation of the estimates. as expected, it can be noted a correspondence between increasing aitchison and geographical distances (figure 5). for middle to latitude samples, the sample being tested tends to remain in between the analogues (in terms of both spatial and geographical distribution). with increasing aitchison distances, farthest away analogues appear, mostly symmetrical with respect to the equator. however, the behaviour is different for high latitude samples, as the sample being tested 64 fig. 4 plots of observed versus estimated sst (annual and seasonal) obtained with 6 analogues. the error bars represent the std of estimates. di donato v. et al. 65 fig. 5 the figure shows, for 4 modern samples located at different latitudes, a) for progressively far analogues, the coordinates on the first 2 axes of the rvb shown in figure 2 and b) their geographical location. the graphs on the left (c) show the differences in sst between a sample and its analogues (blue dots), the sst error for estimates obtained from an increasing number of analogues (green line), and from moving averages of 6 progressively far analogues (red line). palaeoenvironmental reconstructions through coda get into an off-center position as progressively far samples are added. the behaviour is also different for what concern the error of the estimates. for samples located at the border of the cloud of modern data, such as high latitude samples, the increase in the number of analogues corresponds to a progressive increase in the error of the estimates (figure 5). instead, for middle and low latitude samples the increase is less marked. moreover, in several cases, the increase in the number of the analogues (and, consequently, in the aitchison distances) does not imply further decreasing in the quality of estimates. likely, this behaviour arises from the fact that the sst differences obtained moving away from the hypersphere’s centre in opposite directions tend to compensate each other. these results suggest evaluating, in the application of the method to fossil assemblages, the oceanographical coherency of modern analogues and the spatial relationships between a fossil samples and its modern counterparts. more confident estimates are likely obtained when a fossil samples is in between its modern analogues, and when the latter are found into a limited geographical region. summing up, threshold distances for evaluating suspect no-analogue conditions can be determined from atypicality index. in addition, confident estimates should fulfil the criteria of: a) closeness and oceanographical/ geographical coherence of the analogues, b) reduced standard deviation of the estimates, c) staying in the middle of a fossil samples respect to its modern analogues. these results agree with the findings of gujot & de vernal (2011a; 2011b), as geographical closeness among modern analogues appear a prerequisite for obtaining confident estimates. 3.3. application examples as an application example, the coda-mat method was applied to two different planktonic foraminifera records. the first one is a literature dataset, consisting of the very detailed record of planktonic foraminifera assemblages of the core md95-2040 (de abreu et al., 2003; voelker & de abreu, 2011), recovered in the atlantic ocean off the iberian margin, the second is that of gns84-c106 core recovered in the tyrrhenian sea (buccheri et al, 2002; di donato et al., 2008; 2009). both datasets are obtained from >150 μm size fractions. as noted by di donato et al. (2015), the drawback represented by the excessive loss of small sized species in this size fraction can be circumvented, at least in part, by means of coda methods. the fact remains nevertheless that the unavailability of large modern datasets based on smaller size fractions imposes the choice of the >150 μm one which is not an optimal solution. the atypicality index computed with log-ratio mahalanobis distances for each sample of the modern database (see section 2.4.1) allowed us to determine a critical value of 26.12 beyond which samples can be considered as outliers. by means of standard and robust atypicality, 91 and 303 outlier samples in the modern database were detected, respectively (figure 6). these results appear rather restrictive because large part of modern samples is detected as outliers. note that, by definition, the mahalanobis distance is a measure of global atypicality, fig. 6 ddplot of squared and robust squared mahalanobis distances for a) modern data set b) core md95-2040 assemblages c) core gns84-c106. the red lines represent the 97.5% percentile level, associated to xi-square value. 66 di donato v. et al. fi g. 7 r ec on st ru ct io n of s ea so na l s s t f or t he la st 2 10 k a of f th e ib er ia n m ar gi n fro m c or e m d 95 -2 04 0 an d co m pa ris on b et w ee n c od am a t an d s im m a x 28 ( de a br eu e t al ., 20 03 , v oe lk er a nd d e a br eu , 2 01 1) r ec on st ru ct ed s s ts . a : s um m er s s t. b ) w in te r s s t. c ) gr ay -s ha de d do ts : d is ta nc e of fo ss il as se m bl ag es fr om e ac h of th e 6 cl os es t m od er n an al og ue s. f ul l lin e: m ea n va lu es . d ) lo f va lu es e ) at yp ic al ity in de x: 0 : n ot s ig ni fic an t; 1: s ig ni fic an t f -g ) gr ay -s ha de d do ts : m ax im um m od ul es o f t he e st im at e er ro rs fo r th e cl os es t 6 m od er n an al og ue s, at r ad ii eq ua l t o th e m ea su re d a itc hi so n di st an ce . f ul l l in e: m ea n va lu es . h ) a lk en on e ba se d s s t re co ns tru ct io n (p ai lle r & b ar d, 2 00 2) . j ) g lo bi ge rin a bu llo id es s ta bl e is ot op e re co rd a nd m ar in e is ot op ic s ta ge s (m is ) (a br eu e t a l., 2 00 3; s ch ön fe ld e t a l., 2 00 3) . 67 palaeoenvironmental reconstructions through coda that is, it is affected by the existence of groups in the data. in contrast, using the lof of modern assemblages, only two samples have values larger than 2, and only 35 samples values higher than 1.4. 3.2.1. atlantic ocean the foraminiferal record of md95-2040 core covers the last 210 ka (de abreu et al., 2003; voelker, & de abreu, 2011). sea surface temperatures for this interval were formerly reconstructed (de abreu et al., 2003) from planktonic foraminifera with simmax28 method (pflaumann et al., 1996). as regards the atypicality of assemblages, for about 19% of the samples, the mahalanobis distances are above the xi-square critical value of 26.11 corresponding to the 97.5 percentile (figure 6). in relation to the 99.5 percentile, 4% of the samples have mahalanobis distances are above the xi-square critical value of 31.32. the robust outlier detection is more restrictive, as about 40% of samples lies beyond the critical value. as for the lof, glacial assemblages are characterised by higher values of up to 2, while most interglacial assemblages have lof values not exceeding 1.5. coherently, the mean distance of closest analogues is lower for interglacial periods. however, the expected maximum errors of the estimates are rather stable throughout the core (figure 7). the comparison with the values reconstructed for summer and winter sst by means of simmax28 (figure 7) (de abreu et al., 2003), highlights a same general trend, with decreasing sst around the transition between mis 7 and mis 6. from mis 6 to mis 4, both methods record colder intervals (around 160 ka, 130 ka, 85 ka and 60 ka bp) which are also evident in the alkenone-based sst reconstructions and in the oxygen stable isotopes record. in addition, coda-mat gives evidence to a negative sst peak around 108 ka bp, which is also evident in the alkenones and δ18o record. simmax28 and coda-mat reconstructions are quite different for the interval between 50 ka and 20 ka bp. although the reconstructed values for the most prominent sst decreases (at 40 ka, 30 ka and 16 ka bp) are similar, for this time interval coda-mat provides less fluctuating sst values, which appear more fig. 8 geographical (left column) and spatial (right column) relationships among selected foraminiferal assemblages of core md95-2040 and the modern coretop assemblages. numbers indicate the ranking of the closest modern analogues. fig. 9 location of regionalised modern planktonic foraminifera coretop assemblages adopted for application of coda-mat to the core gns84-c106. drawn with ocean data view software (schlitzer 2018). 68 di donato v. et al. fi g. 1 0 c od am a t re co ns tru ct io n of s ea so na l s s t ob ta in ed fr om g n s 84 -c 10 6 c or e. a ) su m m er b ) w in te r. t he e rr or b ar s in di ca te th e st an da rd d ev ia tio n of e ac h re co ns tru ct ed v al ue . c ) gr ay -s ha de d do ts : d is ta nc e of fo ss il as se m bl ag es fr om e ac h of th e 6 cl os es t m od er n an al og ue s. f ul l l in e: m ea n va lu es . d ) lo f va lu es e ) at yp ic al ity in de x: 0 : n ot s ig ni fic an t; 1: s ig ni fic an t f g) g ra ysh ad ed d ot s: m ax im um m od ul es o f th e es tim at e er ro rs f or t he c lo se st 6 m od er n an al og ue s, a t ra di i e qu al t o th e m ea su re d a itc hi so n di st an ce . fu ll lin e: m ea n va lu es . th e in ti m a te g re en la nd e ve nt s tra tig ra ph y is re po rte d fro m r as m us se n et a l. (2 01 4) . 69 palaeoenvironmental reconstructions through coda coherent with the alkenone-based sst reconstructions and δ18o stable isotope record. the spatial and geographical relationships between selected fossil assemblages of the core md95-2040 and their closest modern analogues are shown in figure 8. it can be noted that the modern analogues of some fossil assemblages characterised by higher lof, are located in the south and north atlantic ocean, mostly symmetrical with respect to the equator. 3.2.2. tyrrhenian sea (western mediterranean sea) the core gns84-c106 core covers the last 34 ka (di donato et al., 2009). following kucera et al. (2005), the application of the coda-mat was carried out on a regionalised modern dataset represented by mediterranean and north atlantic coretop assemblages (figure 9). the amplitude of sst changes (figure 10) is of about 10°c, the lower values being recorded between 15 and 17.5 cal ka bp. it can be noted that holocene samples younger than 6 cal ka bp are characterised by low standard deviation, low mean distances from the closest modern analogues and low lof. early holocene assemblages are characterised by slightly higher mean distances, albeit the low lof values. on the contrary, the increasing mean distances obtained for late glacial and last glacial period (lgp) assemblages corresponds to an increase in the standard deviation of the estimates. moreover, the mean distances reach values of up to 5, which are beyond the maximum value obtained for modern assemblages. as regards the atypicality of fossil assemblages, with a critical value of 21.92, several assemblages of this core, in particular from the lgp, can be considered as outliers with respect to the modern dataset (figure 6). comparable results are obtained by considering the expected errors of the estimates obtained by means hypersphere radius evaluation (figure 10). the “expected errors” are below 1°c for the last 5 ka. the higher mean distances recorded in the early holocene (between 9 and 5 ka bp) corresponds to a first increase in expected errors, with values ranging from 1° to 2°c. noteworthy this interval is coeval with the eastern mediterranean sapropel s1 event, during which the mediterranean oceanographical asset was quite different from today (e.g. emeis et al., 2000; ni fhlaithearta et al., 2010). higher values, in the order of 2°c were found for the lgp. the spatial and geographical relationships between selected fossil assemblages and their modern counterparts are shown in figure 11. it can be noted that when the modern analogues are found at higher distances, there are some oceanographic incoherencies. as an example, it can be noted that the closest modern analogues of an lgp assemblage dated at 21.3 cal ka are partly found in the atlantic ocean, partly in the mediterranean sea. moreover, in addition to being characterised by high lof and significant atypicality, in the rvb plot this fossil assemblages seems lying off centre with respect to its modern analogues. a marked oceanographic incoherence also characterises the assemblage dated at 13.5 cal ka. in summary, atypicality of samples and oceanographic incoherency, suggests caution in the interpretation of the reconstructed sst, for the late glacial and the lgp intervals of this core, at least for the >150 μm size fraction adopted for the analysis. the results obtained with coda-mat have been compared with those obtained with raw data analysis and squared chord distance adopted as similarity measure (figure 10). the results appear comparable for the holocene interval of the core, fig. 11 geographical (left column) and spatial (right column) relationships among selected foraminiferal assemblages of core gns84-c106 and the modern coretop assemblages. numbers indicate the ranking of the closest modern analogues. 70 di donato v. et al. however for the late glacial and last glacial period, the coda-mat reconstructed sst are much lower than those obtained with raw data mat, which appear even higher than present for the 19-25 cal ka interval. for this case study, the results are likely influenced by the size fraction commonly adopted for the modern planktonic foraminiferal coretop databases, i.e the excessive loss of small sized specimens of t. quinqueloba in the >150micron size fraction (di donato et al., 2015). in this respect, it should be noted that are currently not available core top databases of planktonic foraminifera assemblages built with smaller size fractions. however, it is likely that the adoption of smaller size fractions would produce lower sst estimates for the lgp intervals of the gns84-c106 core. 4. conclusive remarks in general, the leave-one-out cross validation performed on coda-mat with modern data yielded correlations between estimated and measured modern values in the range of methods such as imbrie and kipp transfer functions, simmax or ram if applied to atlantic ocean (waelbroeck et al., 1998). however, as pointed out above, the proposal of a method based on coda has not the objective of increase the correlation obtained from previous methods, but rather to develop the method coherently with the nature of data. up to now, despite the advances in the statistical theory, only a relatively few micropaleontological studies adopted an approach coherent with coda principles (buccianti & esposito, 2004; di donato et al., 2009; sgarrella et al., 2012; di donato et al., 2018). apart from these fundamental issues, coda-mat also provides tools for evaluate the reliability of estimates performed on fossil assemblages and the occurrence of atypical fossil assemblages. the application of coda-mat to the examples highlighted a coherent behaviour and, for the iberian margin, a strong coherence with the stable isotopes record. about the tyrrhenian sea case study, the caution is suggested regarding lgp sst estimates. however, the coda approach seems less subjected to problems related to preparation techniques (i.e. size fraction) than raw data analysis. although application examples of coda-mat are described in a palaeoceanographic context, this method can be obviously applied to different proxies, i.e. to reconstruct past atmospheric environments, as usually done in palynological studies. further studies, involving the application of coda-mat to continental proxies will be carried out to evaluate its performing. acknowledgements we would like to thank prof. caterina morigi and an anonymous reviewer for their kindly and constructive comments, which helped us to improve the manuscript. this work has been supported by the project “codaretos” (spanish ministry of economy and competitiveness; ref: mtm2015-65016-c2-1-r). references aitchison j. (1986) the statistical analysis of compositional data. monographs on statistics and applied probability. chapman & hall ltd. (reprinted 2003 with additional material by the blackburn press), london (uk), pp. 416. aitchison j., barceló-vidal c., martín-fernández j.a., pawlowsky-glahn v. (2000) logratio analysis and compositional distance. mathematical geology, 32 (3), 271-275. antonov j.i., seidov d., boyer t.p., locarnini r.a., mishonov a.v., garcia h.e. (2010) world ocean atlas 2009 volume 2: salinity. s. levitus, ed., noaa atlas nesdis 69, u.s. government printing office, washington, d.c., pp. 184. barceló-vidal c, martín-fernández j.a. (2016) the mathematics of compositional analysis. austrian journal of statistics, 45(4), 57-71. barrows t.t, juggins s. (2005) sea-surface temperatures around the australian margin and indian ocean during the last glacial maximum. quaternary science reviews, 24, 1017-1047. birks h.j.b. (1995) quantitative palaeoenvironmental reconstructions. in: maddy d., brew j.s. (eds.), statistical modelling of quaternary science data. technical guide 5. quaternary research association, cambridge, 116-254. brassell s.c., eglinton g., marlowe i.t., pflaumann u., sarnthein m. (1986) molecular stratigraphy: a new tool for climatic assessment. nature, 320 (6058), 129-133. breunig m.m., kriegel h.p., ng r.t., sander j. (2000) lof: identifying density-based local outliers. in proceedings of the 2000 acm sigmod international conference on management of data (sigmod '00). acm, new york, ny, usa, 93-104. doi: http://dx.doi.org/10.1145/342009.335388. buccheri g., capretto g., di donato v., esposito p., ferruzza g., pescatore t., russo ermolli e., senatore, m.r., sprovieri, m., bertoldo, m., carella d., madonna g. (2002) a high resolution record of the last deglaciation in the southern tyrrhenian sea: environmental and climatic evolution. marine geology, 186, 447-470. buccianti a., mateu-figueras g., pawlowsky-glahn v. (eds.) (2006) compositional data analysis in the geosciences: from theory to practice. in: special publications, 264. geological society, london. buccianti a., esposito p. (2004) insights on late quaternary calcareous nannoplankton assemblages under the theory on statistical analysis for compositional data: an application example. palaeogeography, palaeoclimatology, palaeoecology, 202, 209-227. daunis-i-estadella j., thió-henestrosa s., mateufigueras g. (2011 including supplementary elements in a compositional biplot. computers & geosciences, 37, issue 5, may 2011, 696-701. de abreu l., shackleton n.j., schonfeld,j., hall m., chapman m. (2003) millennial-scale oceanic climate variability off the western iberian margin 71 palaeoenvironmental reconstructions through coda during the last two glacial periods. marine geology, 196 (1-2), 1-20. di donato v., esposito p., garilli v., naimo d., buccheri g., caffau m., ciampo g., greco a., stanzione d. (2009) surface-bottom relationships in the gulf of salerno (tyrrhenian sea) over the last 34 kyr: compositional data analysis of palaeontological proxies and geochemical evidence. geobios, 42, 561-579. di donato v., esposito p., russo ermolli e., scarano a., cheddadi r. (2008) coupled atmospheric and marine palaeoclimatic reconstruction for the last 35 ka in the sele plain-gulf of salerno area (southern italy). quaternary international, 190, 146 -157. di donato v., insinga d.d., iorio m., molisso f., rumolo p., cardines c. passaro s. (2018) the palaeoclimatic and palaeoceanographic history of the gulf of taranto (mediterranean sea) in the last 15 ky. global and planetary change, 172, 278-297. doi: 10.1016/j.gloplacha.2018.10.014. di donato v., martin-fernandez j.a., daunis-i-estadella j. esposito p. (2015) size fraction effects on planktonic foraminifera assemblages: a compositional contribution to the golden sieve rush. mathematical geosciences, 47 (4), 455-470. egozcue j.j., pawlowsky-glahn v., mateu-figueraz g., barceló-vidal c. (2003) isometric logratio transformations for compositional data analysis. mathematical geology 35 (3), 279-300. elderfield h., ganssen g. (2000) past temperature and δ18o of surface ocean waters inferred from foraminiferalmg/ca ratios. nature, 405, 442-445. emeis k.c., struck u., schulz h.m., rosenberg r., bernasconi s., erlenkeuser h., sakamoto t., martinez-ruiz f. (2000) temperature and salinity variations of mediterranean sea surface waters over the last 16,000 years from records of planktonic stable oxygen isotopes and alkenone unsaturation ratios. palaeogeography, palaeoclimatology, palaeoecology, 158 (3-4), 259-280. doi: 10.1016/s0031-0182(00)00053-5. everitt b.s., landau s., leese m., stahl d. (2011) cluster analysis. john wiley & sons, ltd, chichester, united kingdom, 5th edition, pp. 330. filzmoser p., hron, k. (2008) outlier detection for compositional data using robust methods. math. geosciences, 40, 233-248. guiot j., de vernal a. (2011a) is spatial autocorrelation introducing biases in the apparent accuracy of paleoclimatic reconstructions?. quaternary science reviews 30, 1965-1972. guiot j., de vernal a. (2011b) qsr correspondence “is spatial autocorrelation introducing biases in the apparent accuracy of palaeoclimatic reconstructions?” reply to telford and birks. quaternary science reviews, 30, 3214-3216. hayes a., kucera m., kallel n., sbaffi l., rohling e. (2004) compilation of planktic foraminifera modern data from the mediterranean sea. pangaea. doi:10.1594/pangaea.227305. hutson w.h. (1979) the agulhas current during the late pleistocene: analysis of modern faunal analogues. science, 207 (1), 64-66. imbrie j. kipp n.g. (1971) a new micropaleontological method for paleoclimatology: application to a late pleistocene caribbean core. the late cenozoic glacial ages. new haven, yale university press. 71-181. kucera m., weinelt m., kiefer t., pflaumann u., hayes a., weinelt m., chen m.t., mix a.c., barrows t., cortijo e., duprat j., juggins s., waelbroeck c. (2004) compilation of planktic foraminifera census data, modern from the atlantic ocean. pangaea. doi:10.1594/pangaea.227322. kucera m., rosell-melé a., schneider r., waelbroeck c., weinelt m. (2005) multiproxy approach for the reconstruction of the glacial ocean surface (margo). quaternary science reviews, 24 (7-9), 813-819. locarnini r.a., mishonov a.v., antonov j.i., boyer t.p., garcia h.e. (2010) world ocean atlas 2009, volume 1: temperature. s. levitus, ed., noaa atlas nesdis 68, u.s. government printing office, washington, d.c., pp.184. malmgren b.a., kucera m., nyberg j. waelbroeck c. (2001) comparison of statistical and artificial neural network techniques for estimating past sea surface temperatures from planktonic foraminifer census data. paleoceanography, 16 (5), 520-530. doi:10.1029/2000pa000562. martín-fernández j.a., barceló-vidal c., pawlowskyglahn v. (2003) dealing with zeros and missing values in compositional datasets using nonparametric imputation. mathematical geology, 35 (3), 253-278. martín-fernández j.a., hron k., templ m., filzmoser p,. palarea-albaladejo j. (2015) bayesianmultiplicative treatment of count zeros in compositional datasets. statistical modelling, 15(2), 134158 martín-fernández j.a., thió-henestrosa s. (eds.) (2016a) compositional data analysis: codawork, l’escala, spain, june 2015. springer proceedings in mathematics & statistics, 187. springer international publishing, new york (usa). martín-fernández j.a., thió-henestrosa s. (guest eds.) (2016b) compositional data analysis. austrian journal of statistics, 45(4). mateu-figueras g., pawlowsky-glahn v., egozcue j.j. (2011) (pawlowsky-glahn v, buccianti a., eds). the principle of working on coordinates, in compositional data analysis: theory and applications. john wiley & sons, ltd, chichester, uk, 29-42 ni fhlaithearta s., reichart g.j., jorissen f.j., fontanier c., rohling e.j., thomson j., de lange, g.j. (2010) reconstructing the sea floor environment during sapropel formation using trace metals and sediment composition. paleoceanography, 25, pa4225. doi:10.1029/2009pa001869, 2010. 72 di donato v. et al. overpeck j.t., webb t., prentice i.c. (1985) quantitative interpretation of fossil pollen spectra: dissimilarity coefficients and the method of modern analogues. quaternary research, 23, 87-108. pailler d., bard e. (2002) high frequency palaeoceanographic changes during the past 140 000 yr recorded by the organic matter in sediments of the iberian margin. palaeogeography, palaeoclimatology, palaeoecology, 181, 431-452. palarea-albaladejo j., martín-fernández j.a., soto j.a. (2012) dealing with distances and transformations for fuzzy c-means clustering of compositional data. journal of classification 29 (2), 144169. pawlowsky-glahn v, egozcue j.j., tolosana-delgado r. (2015) modeling and analysis of compositional data. john wiley & sons, chichester, pp. 378. peña d., prieto, f. (2001) multivariate outlier detection and robust covariance matrix estimation. technometrics, 43 (3), 286-310. pflaumann u., duprat j., pujol c., labeyrie l.d. (1996) simmax: a modern analogue technique to deduce atlantic sea surface temperatures from planktonic foraminifer in deep-sea sediments. paleoceanography, 11, 15-36. prell w., martin a., cullen j., trend m. (1999) the brown university foraminiferal data base. igbp pages/world data center-a for paleoclimatology data contribution series # 1999-027. noaa/ ngdc paleoclimatology program, boulder, co, usa. rasmussen s.o., bigler m., blockley s.p., blunier t., buchardt s.l., clausen h.b., cvijanovic i., dahl-jensen d., johnsen s.j., fischer h., gkinis v., guillevic m., hoek w.z., lowe j.j., pedro j.b., popp t., seierstad i.k., peder steffensen j., svensson a.m., vallelonga p., vinther b.m., walker m.j.c., wheatley j.j., winstrup m. (2014) a stratigraphic framework for abrupt climatic changes during the last glacial period based on three synchronized greenland ice-core records: refining and extending the intimate event stratigraphy. quaternary science reviews, 106, 14-28. r development core team (2011) r: a language and environment for statistical computing. r foundation for statistical computing, vienna, austria. http://www.r-project.org. schlitzer r. (2018) ocean data view. http://odv.awi.de. schönfeld j., zahn r., de abreu l. (2003) stable isotope ratios and foraminiferal abundance of sediment cores from the western iberian margin. doi:10.1594/pangaea.733303. supplement to: schönfeld j., zahn r., de abreu l. (2003) surface to deep water response to rapid climate changes at the western iberian margin. global and planetary change, 36(4), 237-264. doi:10.1016/s0921-8181(02)00197-2. sgarrella f., di donato v., sprovieri r. (2012) benthic foraminiferal assemblage turnover during intensification of the northern hemisphere glaciation in the piacenzian punta piccola section (southern italy). palaeogeography, palaeoclimatology, palaeoecology, 333-334, 59-74. doi: 10.1016/j.palaeo.2012.03.009. tauber f. (1999) spurious clusters in granulometric data caused by logratio transformation. mathematical geology, 31, 491-504. telford r.j., birks h.j.b. (2009) evaluation of transfer functions in spatially structured environments. quaternary science reviews, 28, 1309-1316. telford r.j., birks h.j.b. (2011) is spatial autocorrelation introducing biases in the apparent accuracy of palaeoclimatic reconstructions? quaternary science reviews, 30, 3210-3213. ter braak c.l.f., juggins s. (1993) weighted averaging partial least squares regression (wa-pls): an improved method for reconstructing environmental variables from species assemblages. hydrobiologia. 2691270, 485-502. voelker a.h.l., de abreu l. (2011) a review of abrupt climate change events in the northeastern atlantic ocean (iberian margin): latitudinal, longitudinal and vertical gradients. in: rashid h., polyak l., mosley-thompson e. (eds), abrupt climate change: mechanisms, patterns, and impacts. geophysical monograph series (agu, washington d.c.), 193, 15-37. doi:10.1029/2010gm001021. waelbroeck c., labeyrie l., duplessy j.c., guiot j. labracherie m. (1998) improving past sea surface temperature estimates based on planktonic fossil faunas. paleoceanography, 13, 272-283. wallach d., goffmet b. (1989) mean squared error of prediction as a criterion for evaluating and comparing system models. ecological modelling, 44, 299306. ms. received: july 18, 2018 final text received: october 9, 2018 73 palaeoenvironmental reconstructions through coda 74 available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 35 38 lgm incised valley in a volcanic setting. the northern campania plain (southern italy) ruberti daniela 1 , sacchi marco 2 , pepe fabrizio 3 , vigliotti marco 1 1 engineering department, campania university “l. vanvitelli”, aversa (ce), italy 2 iamc cnr, napoli, italy 3 dipartimento di scienze della terra e del mare (distem), università di palermo, palermo, italy corresponding author: d. ruberti <daniela.ruberti@unicampania.it> abstract: the study provides a first reconstruction of the lgm incised valley of the volturno river, in the northern campania plain. a digital surface model was reconstructed for the campania grey tuff top (39 ky), which represents the base for the holocene and recent sedimentation. stratigraphic data from the subsurface of the volturno plain have been correlated with a high-resolution (1kj sparker) single channel reflection seismic profile offshore the volturno river mouth in order to provide a sequence stratigraphic interpretation. keywords: campania plain, volturno river, last glacial maximum, incised valley, holocene evolution 1. introduction incised valleys are stratigraphic systems, larger than a single channel, resulting from rapid river erosion of coastal regions in response to base level fall. incisedvalley systems at continental margins have been widely studied in the last decades, documenting a range of sedimentary architectures and evolutionary trends of depositional systems, as a function of global to local environmental and climatic changes (e.g.; blum & tornqvist, 2000; boyd et al., 2006; tanabe et al., 2006, and references therein). early investigations have mostly focused on the development of facies models for incised valley systems (e.g. dalrymple et al., 1994) and the recognition of these features as a key to the identification of sequencebounding unconformities. growing attention has been paid also to prograding sand units filling incised valleys as modern analogues to buried sands in the ancient rock record, with a potential for hydrocarbon prospecting (e.g. boyd et al., 2006; tanabe et al., 2006). case histories of incised-valley systems of the mediterranean have been documented in the last decade along italian continental margins (e.g. fontana et al., 2014; amorosi et al., 2012, 2017; milli et al., 2016; tropeano et al., 2013; maselli et al., 2014). however, most studies have dealt with descriptive documentation on architecture of incised-valley fills in continental siliciclastic environments, whereas relatively little work has focused on correlation of marine and continental strata across continental margins, where sediment dynamics is dominated by mixed siciliclastic-volcaniclastic systems. the aim of this research is to present a paleomorphological reconstruction of the buried incised valley of the volturno river, across the coastal region connecting the northern campania plain and the gaeta bay during the last glacial cycle (fig. 1). the study is based on comprehensive set of onland borehole data and offshore reflection profiles and will attempt an interpretation of the volturno incised valley as an example of a highly dynamic stratigraphic system dominated by volcanic activity during severe climatic changes. 2. geological setting the campania plain is part of a large extensional sedimentary basin mostly formed during the quaternary between the western flank of the southern apennines and the eastern tyrrhenian margin. this area remained largely submerged by the sea since middle-late pleistocene, when the widespread volcanic activity that occurred along the campania continental margin produced significant volcaniclastic aggradation. in particular, campania grey tuff (cgt) deposition, originated by the campi flegrei caldera 39 ka eruption, covered previous marine-transitional settings and since 39 ky b.p. most of the coastal plain became emerged. the above piroclastic unit forms the substrate for the holocene and recent sedimentation. similarly to other italian alluvial coastal plains, 6.5 ky cal bp a coastal progradational phase established, allowing the formation of a wave-dominated delta system, with strandplains forming beach-dune ridges partially enclosing lagoonal-marshy areas (amorosi et al., 2012; sacchi et al., 2014). the stratigraphic studies carried out by the above authors allowed the recognition of a palaeo-valley morphology in the upper surface of the gct in the whole plain, likely originated as a response to the last glacial maximum sealevel drop. 3. materials and methods the late quaternary stratigraphic framework of the volturno alluvial and coastal plain was assessed based on the analysis and correlation of over 800 stratigraphic data deriving from borehole and sediment cores. the https://doi.org/10.26382/aiqua.2018.aiquaconference stratigraphic interpretation was previously published in amorosi et al. (2012) and sacchi et al. (2014). in the present contribution all the information derived from the mentioned stratigraphic study were collected into a relational geodatabase concerning with well-log stratigraphy and further interpreted and homogenized in terms of lithologic units, also containing the related thickness and upperand lower-boundary depth a.s.l. the upper cgt surface was reconstructed in order to highlight the buried morphologies. stratigraphic data were correlated with high-resolution (1kj sparker) single channel reflection seismic profile. 4. results and discussion the digital surface model reconstructed for the upper cgt surface shows a 15-20 km wide late quaternary paleovalley incised by the volturno river into the thick ignimbritic unit (fig. 2). the asimmetry of the southern valley flanks was shaped by the presence of an ancient river (clanio river), reclaimed during the xvi century (ruberti & vigliotti, 2017), that resulted in the enlargement of the valley and the formation of a complex deltaic system in the southern part (fig. 2). correlation of stratigraphic data from the subsurface of the volturno plain with sequence stratigraphic interpretation of high-resolution (1kj sparker) single channel reflection seismic profile offshore the volturno river mouth indicates that the volturno buried paleovalley was likely incised throughout the late pleistocene – early holocene, during the last glacial eustatic cycle (fig. 3). valley incision progressively developed in relation with the lowering of the sea level between ca. 100 and 20 ka bp., and was accompanied by a forced progradation and seaward shift of continental and paralic depositional systems as the coastline was migrating seaward (e.g. amorosi et al., 2012). during sea level fall, a major ignimbrite unit originated from the campi flegrei region and it was deposited all over the campania area and 36 fig. 1 geological map of a sector of northern campania. red box indicates the study area. ruberti d. et al. 37 mantled large part of the coastal sector, also providing significant sediment input into the volturno incised valley as a part of a mixed siliciclastic-volcaniclastic source -sink system. the boundary between the substratum of the paleovolturno valley and its sedimentary fill is marked by a well-developed unconformity and associated stratigraphic gap that separates the older quaternary alluvial deposits and the campania ignimbrite (ca 40 ka bp) from the overlying uppermost pleistocene-holocene coastal prism entrenching the incised valley. the onset of the sea-level rise, that followed the climax of the last glacial maximum since ca. 15 ka bp, caused marine ingression deep into the volturno incised valley and was associated with rapid backstepping and landward shift of depositional systems. maximum marine flooding conditions are documented at 7,0-6,5 ka bp by the occurrence of prodeltaic deposit, that have been cored between 18 and 25 m beneath the surface at cv001 drill site (amorosi et al., 2012). since the middle holocene, a progressive lowering of the post glacial sea-level rise created conditions fig. 2 contour map of the cgt upper boundary. the dotted red line outline the outer margin of the incised valley . fig. 3 land-sea correlation of stratigraphic data from the subsurface of the volturno plain with sequence stratigraphic interpretation of high-resolution (1kj sparker) single channel reflection seismic profiles offshore the volturno river mouth (after amorosi et al., 2012; sacchi et al., 2014; margaritelli et al., 2016; misuraca et al, 2018). lgm incised valley in a volcanic setting favorable to early aggradation (6,5 -4,5 ka bp) and late stage progradation (< 4,5 ka), accompanied by seaward shift of depositional systems (sacchi et al, 2014; margaritelli et al, 2016; misuraca et al, 2018). this caused, in turn, a rapid filling of the accommodation space over the former incised valley, with the formation of the modern volturno alluvial plain, coastal lagoon and beach barrier system. 5. conclusive remarks the study provides a first reconstruction of the lgm incised valley of the volturno river, in the northern campania plain. as previously outlined, the valley incision took place in a stepwise fashion, as documented by the presence of remnants of fluvial terraces along the valley flanks. stratigraphic data from the subsurface of the volturno plain have been correlated with a high-resolution (1kj sparker) single channel reflection seismic profile offshore the volturno river mouth in order to provide a sequence stratigraphic interpretation. the study allowed to better constrain the holocene depositional evolution of the volturno river delta. references amorosi a., pacifico a., rossi v., ruberti d., (2012) late quaternary incision and deposition in an active volcanic setting: the volturno valley fill, southern italy. sedimentary geology 282, 307-320. amorosi a., bruno l., campo b., morelli a., rossi v., scarponi d., hong w., bohacs k. m., drexler t. m. (2017) global sea-level control on local parasequence architecture from the holocene record of the po plain, italy. marine and petroleum geology, 87, 99-111. doi: 10.1016/j.marpetgeo.2017.01.020 blum m.d., törnqvist t.e. (2000) fluvial responses to climate and sea-level change: a review and look forward. sedimentology, 47, 2-48. boyd r., darlymple r.w., zaitlin b.a. (2006) estuarine and incised-valley facies models.in: posamentier, h.w., walker, r.g. (eds.), facies models revisited. sepm (societyof economic paleontologists and mineralogists) spec. publ., 84, 171-235. dalrymple r.w., boyd r., zaitlin b.a. (1994) history of research, types and internal organization of incised -valley systems: introduction to the volume. in: dalrymple, r.w., boyd, r., zaitlin, b.a. (eds.), incised-valley systems: origin and sedimentary sequences. sepm, special publication, 51, 3-10. fontana a., monegato g., zavagno e., devoto s., burlac i., cucchi f. (2014) evolution of an alpine fluvioglacial system at the lgm decay: the cormor megafan (ne italy). geomorphology, 204(1), 136-153 margaritelli g., vallefuoco m., di rita f., capotondi l., bellucci l.g., insinga d.d., petrosino p., bonomo s., cacho i., cascella a., ferraro l., florindo f., lubritto c., lurcock p.c., magri d., pelosi n., rettori r., lirer f. (2016) marine response to climate changes during the last five millennia in the central mediterranean sea. glob. planet. change, 142, 53 -72. doi.org/10.1016/j.gloplacha.2016.04.007 maselli v., trincardi f., asioli a., ceregato a., rizzetto f., taviania m. (2014) delta growth and river valleys: the influence of climate and sea level changes on the south adriatic shelf (mediterranean sea). quaternary science reviews, 99, 146-163 milli s., mancini m., moscatelli m., stigliano f., marini m., cavinato g. p. (2016) from river to shelf, anatomy of a high‐frequency depositional sequence: the late pleistocene to holocene tiber depositional sequence. sedimentology, 63, 18861928 misuraca m., budillon f., tonielli r., di martino g., innangi s., ferraro l. (2018) coastal evolution, hydrothermal migration pathways and soft deformation along the campania continental shelf (southern tyrrhenian sea): insights from highresolution seismic profiles. geosciences, 8(4), 121. doi: 10.3390/geosciences8040121 ruberti d., vigliotti m. (2017) land use and landscape pattern changes driven by land reclamation in a coastal area: the case of volturno delta plain, campania region, southern italy. environmental earth sciences, vol. 76, 694. doi: 10.1007/s12665-017-7022-x sacchi m. et alii, 2014. late-holocene to recent evolution of lake patria, south italy: an example of a coastal lagoon within a mediterranean delta system. global and planetary change, 117, 9-27 tanabe s., saito y., vu q.l., hanebuth t.j.j., ngo q.l., kitamura a. (2006) holocene evolution of the song hong (red river) delta system, northern vietnam. sedimentary geology, 187, 29-61. tropeano m., cilumbriello a., sabato l., gallicchio s., grippa a., longhitano s.g., bianca m., gallipoli m.r., mucciarelli m., spilotro g. (2013) surface and subsurface of the metaponto coastal plain (gulf of taranto-southern italy): present-dayvs lgm-landscape. geomorphology, 203, 155-131. doi: 10.1016/j.geomorph.2013.07.017 38 ruberti d. et al. ms. received: may 21, 2018 final text received: may 28, 2018 https://www.sciencedirect.com/science/article/pii/s0169555x13003978#! https://www.sciencedirect.com/science/article/pii/s0169555x13003978#! https://www.sciencedirect.com/science/article/pii/s0169555x13003978#! https://www.sciencedirect.com/science/article/pii/s0169555x13003978#! https://www.sciencedirect.com/science/article/pii/s0169555x13003978#! https://www.sciencedirect.com/science/article/pii/s0169555x13003978#! https://www.sciencedirect.com/science/article/pii/s0169555x13003978#! https://www.sciencedirect.com/science/article/pii/s0169555x13003978#! https://www.sciencedirect.com/science/article/pii/s0169555x13003978#! https://doi.org/10.1016/j.gloplacha.2016.04.007 https://www.sciencedirect.com/science/article/pii/s0277379114002431#! https://www.sciencedirect.com/science/article/pii/s0277379114002431#! https://www.sciencedirect.com/science/article/pii/s0277379114002431#! https://www.sciencedirect.com/science/article/pii/s0277379114002431#! https://www.sciencedirect.com/science/article/pii/s0277379114002431#! https://www.sciencedirect.com/science/article/pii/s0277379114002431#! https://www.sciencedirect.com/science/article/pii/s0277379114002431#! https://www.sciencedirect.com/science/article/pii/s0277379114002431#! https://www.sciencedirect.com/science/article/pii/s0277379114002431#! https://onlinelibrary.wiley.com/action/dosearch?contribauthorstored=milli%2c+salvatore https://onlinelibrary.wiley.com/action/dosearch?contribauthorstored=mancini%2c+marco https://doi.org/10.3390/geosciences8040121 http://dx.doi.org/10.1016/j.geomorph.2013.07.017 the pre-modern human fossil record in italy from the middle to the late pleistocene: an updated reappraisal. costantino buzi 1,2 , fabio di vincenzo 3,4 , antonio profico 5 , giorgio manzi 1 1 dipartimento di biologia ambientale, università di roma “sapienza”, rome, italy. 2 dfg centre of advanced studies ‘words, bones, genes, tools’, eberhard karls universität tübingen, tübingen, germany. 3 museo di storia naturale, università di firenze, florence, italy. 4 istituto italiano di paleontologia umana, anagni, rome, italy. 5 palaeohub, department of archaeology university of york, york, united kingdom. corresponding author: g. manzi <giorgio.manzi@uniroma1.it> abstract: the fossil record from the italian peninsula is of special interest for assessing the variability of pre-modern human populations (i.e., extinct humans non-belonging to the proper species homo sapiens) and their evolutionary history. in 2005, a detailed “catalogue of italian fossil human remains from the palaeolithic to the mesolithic” was published and still represents a milestone on the topic, which however requires a reappraisal. here we provide a commented overview of the pre-modern human fossil record from the italian peninsula, where we have included updated information on specimens that were already in the catalogue of 2005 as well as new discoveries of the recent years, thus providing a comprehensive report of this important regional samples. we hope that this work may represent a useful state-of-the-art on the topic. it also embodies notes concerning the more sophisticated technologies that have been applied in the last years to document and study such a paleoanthropological archive, allowing the acquisition of new data even from old specimens. keywords: palaeoanthropology, human evolution, neanderthal lineage, homo heidelbergensis, homo neanderthalensis. available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 34(1), 2021, 17-32 1. introduction the italian peninsula represents an interesting paleo-ecological scenario for the late early and early middle pleistocene faunal dispersals (homo included) in europe. human presence in italy has been reported as dating back to 1.6-1.3 ma, as inferred from the lithic assemblage found at pirro nord in southern italy (arzarello et al., 2007; arzarello & peretto, 2017). therefore, italy appears as the node for subsequent dispersals in the continent, which can be described as complex, both in space as well as time, and strongly influenced by ecological factors (manzi et al., 2011). this picture is paired with indirect and direct evidence attesting the earliest human presence in southeastern and western europe between 1.8 ma (parés et al, 2006; garcia et al., 2010) and 1.2/1.1 ma (carbonell et al., 2008). the scanty fossil record pertaining to these first europeans highlights the occurrence of archaic and rather variable skeletal features (bermúdez de castro et al., 2011; bermúdez de castro et al., 2017) in association with mode 1 (i.e., oldowan) lithic technologies (carbonell et al., 1995). it appears that subsequent human dispersals in europe were associated with a turnover of mammalian species that benefited of periods of climatic instability, being more adapted to the new habitats and resources, particularly in italy (manzi et al., 2011; magri & palombo, 2013). humans, by possessing characteristics of opportunist scavengers, were probably favoured by the fragmentation of the landscape (blain et al., 2019). the italian paleontological and archaeological record associated to the earliest phases is limited to a few sites dated earlier than 700 ka and scattered along the entire peninsula below the po valley. as a matter of fact, the first human presence in italy is attested only by lithic assemblages, such as those from pirro nord (puglia) and monte poggiolo (romagna), dated back to a chronological range comprised between 1,6 and 0.85 ma (arzarello & peretto, 2010, 2017), but probably there are also important sites in southern latium (biddittu, 1972; biddittu, 1974, segre & biddittu, 2009), which could have been penecontemporaneous to those in apulia and romagna. for what concerns the fossil record, so far the earliest occurrence in italy starts after the marine isotope stage (mis) 16 and is represented by the partial shaft of a femur from the level supra- of venosa notarchirico (belli et al., 1991; moncel et al., 2020), dated to 661-614 ka (pereira et al., 2015), and the isolated human deciduous incisor from the level 3 (overlying layer 3a) of isernia la pineta, dated to 583-561 ka (peretto et al., 2015; fig.1). it is noteworthy that these two sites, both located in southern italy at a distance of approximately 300 km, as well as rather close in chronology, apparently show differences in the archaeological assemblages. venosa notarchirico has yielded the earliest evidence of acheulean settlement in italy (moncel et al., 2020) and the femur shaft recovered in the upper part of the archaeo https://doi.org/10.26382/amq.2021.03 18 buzi c. et al. logical sequence is at present the oldest fossil human in europe clearly associated with bifaces of mode 2 (i.e., acheulean) technology (fig. 1). on the other hand, the lithic assemblage from isernia la pineta is composed primarily of small and medium-sized flakes of local flint and limestone, with the absence of bifaces (peretto et al., 2015). these differences may reflect local and ecological diversity in subsistence strategies or a more complex population scenario in correspondence of the appearance of bifaces into the european archaeological record after, or around, mis 16 (manzi et al., 2011; moncel et al., 2020; santagata et al., 2020). the human remains from isernia la pineta and venosa notarchirico represent two of the major updates to our knowledge on the pre-modern (i.e., extinct humans non-belonging to the proper species homo sapiens) fossil record in italy since the publication of the "catalogue of italian fossil human remains from the palaeolithic to the mesolithic" (hereafter referred to as "the catalogue") edited by g. alciati and colleagues (2005) following the same template of the “catalogue of fossil hominids” edited by the natural history museum of london (oakley et al., 1971). nonetheless, after 2005 there have been a number of new discoveries of human remains from lower and middle palaeolithic sites across the italian peninsula, while many sites/specimens have been reconsidered; thus, nowadays, the italian human fossil record dated to the middle and early late pleistocene is increased (fig. 2, tab.1). it includes crucial findings attributed to both homo heidelbergensis and homo neanderthalensis; they are of great interest for our understanding of the so-called "neanderthal lineage" over time in the wider european scenario (manzi, 2004, 2016). therefore, in the following sections we present these findings with an approximate chronological criterion and discuss their contribution to the reconstruction of the human evolutionary dynamics during the middle to the early late pleistocene, as documented by the human fossil record from italy. 2. the lower palaeolithic alongside the mentioned novelties for this issue (i.e., isernia la pineta and venosa notarchirico), other important updates approximately referable to the middle of the middle pleistocene (lower paleolithic, mode 2 or acheulean) concern also other sites, including the dating and the anatomical interpretation of relevant specimens already reported in the catalogue of 2005: the calvarium from ceprano and the dental remains from visogliano and fontana ranuccio. 2.1. isernia la pineta we have already reported updates for the sites of venosa-notarchirico and isernia la pineta. however, the latter site requires a separate and more detailed treatment since it was not previously included in the catalogue. the only human remain found so far in the site, in fact, is an isolated human deciduous incisor (labelled is42) discovered in 2014 and described by peretto and colleagues (2015). isernia la pineta (southcentral italy, molise) is an extensive open-air archaeological site of the lower palaeolithic located just outside the city of isernia (41° 35' 27.8" n, 14° 14' 29.3" e) at 457 m above sea level, along the left side of the cavaliere stream, in the middle upper part of the volturno river basin. the site has been discovered in the fluviolacustrine sedimentary series of “le piane basins” during road construction works in 1978. the abundant lithic assemblage and faunal remains are distributed across four archaeosurfaces and two sectors which are now musealized. the faunal assemblage has been attributed to the early toringian and the lithic assemblage is characterized by the exploitation of two local raw materials: flint and limestone (peretto et al., 2015). the stratigraphy of the site has been described by coltorti and colleagues (2005). from bottom to top, five stratigraphic units can be recognised: lacustrine clays (u5), lacustrine travertines (u4), fluvial sediments with sands and fine gravels (u3) sands and gravels (u2), gravels and sands with intercalated tuffs (u1). unit 3 contains the archaeological deposit, and it is subdivided into three sedimentary sub-units (u3a, u3e, u3f). the human tooth was recovered within the archaeological level 3 coll (overlying u3a) that, according to new 40ar/39ar measurements, is dated to about 583–561 ka, i.e. to the end of mis 15 (peretto et al., 2015). the deciduous tooth, which preserved the crown and some 4 mm of the largely resorbed root, is identified as a maxillary left lateral incisor (peretto et al., 2015). the buccolingual diameter is 4.71 mm and the mesio-distal diameter is 5.66 mm. incisal wear has exposed a large strip of dentine on the flat horizontal incisal edge corresponding to the 4th wear stage. on the lingual face the slight cervical eminence is symmetrical, corresponding to grade 1 of “tuberculum dentale” in the asu-das system (scott et al., 2016). both the mesial and distal marginal crests are weakly developed, with the distal more marked. a fig. 1 the human deciduous tooth from isernia la pineta (left, from above, respectively, labial and incisal views, modified from peretto et.al., 2016) and a digital rendering of the femur shaft from venosa notarchirico (right) 19 the pre-modern human fossil record from italy weak mesial sulcus and distal sulcus can also be observed adjacent to the respective marginal crests. no “shovelling” is evident (grade 0 asu-das; peretto et al., 2015). 2.2. ceprano the calvarium from ceprano (fig. 3) comes from a small locality near the towns of castro dei volsci, ceprano hence the name and pofi, in southern latium, less than 100 km south-east of rome. the calvarium was discovered in fragments by the archaeologist italo biddittu in march 1994, during a survey along a trench cut by the bulldozers for the construction of a new road (ascenzi et al., 1996). despite the archaic morphology of ceprano (manzi et al., 2001; mounier et al., 2011; manzi, 2016), the chronology of about 800-900 ka that was originally suggested (ascenzi et al., 1996) has been more recently reassessed and referred to a younger age, bracketed between 430 and 385 ka (manzi et al., 2010). this new fig. 2 distribution of sites in italy with non-modern human remains. sites dated to middle pleistocene are indicated in red, while those dated to late pleistocene are in blue; spinadesco is reported in dashed black because not yet dated (see section 3.2); the sites that yielded new human remains after the publication of the catalogue edited by alciati and colleagues (2005) are highlighted. 20 buzi c. et al. tab. 1 inventory of the italian sites with non-modern human remains and their chronology (based on the most recent data available in the literature); sites are ordered according to their latitude and longitude (see fig. 2). a (*) indicates sites that have been re-considered after being reported in the catalogue of 2005, while (§) indicates either a new site or a site where new remains have been found. from a morphological point of view, ceprano shows absence of any apomorphic neanderthal trait, while it exhibits affinities with specimens attributed to homo heidelbergensis found in ethiopia and zambia (i.e., bodo and kabwe), as already demonstrated by previous studies (manzi et al., 2001; mounier et al., 2011). these results shed further light on the phylogenetic significance of ceprano as the best candidate to represent the ancestral morphology of the putative polymorphic species homo heidelbergensis (manzi, 2016), diversely from previous attributions to a peculiar variant of homo erectus (ascenzi et al., 1996; clarke, 2000) or to a distinct new species (mallegni et al., 2003). 2.3. fontana ranuccio and visogliano about 40 km north-west from ceprano, within the anagni basin, it is located the site of fontana ranuccio. here, in addition to abundant stone and bone bifacials and other artefacts of mode 2, four human fossil teeth were recovered in the 80s of the last century. these and accurate estimate derives form a composite ensemble of data, including geo-stratigraphic and paleoecological data, but also palaeomagnetism (muttoni et al., 2009), k/ar and ar/ar datings (manzi et al., 2010; nomade et al., 2011). portions of the calvarium were found in situ, within stratified fluvio-lacustrine deposits (ascenzi et al., 1996; di vincenzo et al., 2017), while the remaining fragments were recovered in the shaky sediments or in the sieve. no evidence was found of fragments belonging to the facial skeleton. recently, a new digital reconstruction has been performed, correcting the taphonomic distortion of the braincase (di vincenzo et al., 2017). on the digital reconstruction, it was possible to make new observations dealing with both taphonomy and morphology. the interpretation of the intervened taphonomic process revealed that ceprano was found in primary deposition (di vincenzo et al., 2017), thus supporting its date back to about 400 ka (mis 11). at the same time, 21 the pre-modern human fossil record from italy fig. 3 the ceprano calvarium: a) the final physical reconstruction based on the original fragments (ascenzi et al., 2000) is compared to (b) the digital segmentation of the fragments and digital reconstruction, with virtual removal of the plaster, and to (c) the retro-deformation of the calvarium (i.e., removal of the taphonomic deformation), which restores its probable original shape (modified from di vincenzo et al., 2017). human remains were reported in the literature (segre & ascenzi, 1984; ascenzi & segre, 1996), as well as in the catalogue, as the two lower second molars, probably belonging to a single individual, and other two incisors (lower left central and undetermined). a new revision by rubini and colleagues (2014) reclassified the molars as the two lower first molars, while the two incisors were reconsidered as a lower left lateral incisor and a possible upper left canine, respectively. in addition, muttoni and colleagues (2009) provided a new k/ar date of about 0.46 ma for the site of fontana ranuccio. in addition, a recent digital approach has been used to analyse both the enamel thickness and the pulp cavity morphology of the teeth from fontana ranuccio (zanolli et al., 2018). the analysis was also extended by including in the sample the teeth from the site of visogliano (north-eastern italy) recently dated by esr/u-series at an interval between mis 13 and mis 10 (falguères et al., 2008). both samples showed morphological traits shared by neanderthals, indicating a pattern of evolutionary continuity in europe already established during the middle pleistocene in italy (zanolli et al., 2018) as well as elsewhere (arsuaga et al., 1997, 2014). this, alongside with the apparent contrast with ceprano, traces an interesting and complex evolutionary scenario. it can be suggested that some populations of about 400 ka ca retained in italy more archaic morphologies, while other populations in europe – such as atapuerca sima de los huesos in spain (arsuaga et al., 1997, 2014), petralona in greece (stringer, 1983), or steinheim in germany (wolpoff, 1980) – already presented varying grades of a morphological progression towards the typical neanderthal assemblage of traits, suggesting the penecontemporaneous occurrence of different sub-species of homo heidelbergensis (manzi, 2016). 2.4. polledrara di cecanibbio the site of la polledrara di cecanibbio is located in the western sector of the rome basin (41° 56' 05.4" n, 12° 18' 07.8" e), in latium (central italy). it is one of the most interesting mid-pleistocene sites in europe, discovered in 1985 and studied with regular excavations since then. it was not reported in the catalogue, since no human remains had been found there at the time of its publication. the fluvial and fluvio-palustrine fossiliferous deposits of the site are part of the ponte galeria sequence (pgs), and within this, it is included in the pg6 sub-sequence (middle pleistocene, aurelia formation, mis 10 and 9; santucci et al., 2016). the pg6 deposits derive from the contemporaneous resedimentation of a volcanic unit known as “tufi stratificati varicolori di la storta (tfvls)” dated between 379±40 ka and 450±7 ka (marra et al., 2014). the quantity and state of preservation of the faunal remains is significant. they are distributed with varying density on the paleosurface, and are mostly referable to large mammals, as palaeoloxodon antiquus and bos primigenius. faunal assemblages are associated with lithic and bone artifacts (anzidei et al., 2012). no bifaces were recovered in palimpsest, in contrast to other neighbouring and coeval sites (castel di guido, torre in pietra), however, the presence of about 600 flint implements recovered around the carcass of a single elephant in anatomical connection are evidence of a butchery site, where complex human/elephant interactions occurred (santucci et al., 2016). part of the paleosurface (about 900 m2) is musealized. new excavations started in 2006 and led to the recovery of a deciduous second maxillary molar, probably belonging to a juvenile human individual with an age at death comprised between 5 and 10 years (anzidei et al., 2012). the molar lacks a portion of the crown on the distal side and almost all the roots, probably because of post-mortem fractures. the bucco-lingual and mesiodistal measurements of the crown are 10.1 mm and 8.6 mm, respectively. the tooth is in bad state of preservation and the occlusal surface is characterized by a high degree of wear, so that the dentine is totally exposed. a fair presence of tartar was observed at the level of the neck distributed on the buccal, distal and medial surfaces (anzidei et al., 2012). 3. the middle palaeolithic human fossil specimens referable to the middle palaeolithic during the late middle and the early late pleistocene show a mixture of archaic features and more progressive (neanderthal) traits. this is particularly true in the case of the skeleton from altamura (southern italy), as well as in the case of other specimens which reignited the interest of researchers in recent years, thanks to new morphological and chronological data. important updates with respect to the catalogue of 2005 comes from the localities saccopastore, taddeo cave, broion shelter, tagliente shelter, fumane cave, fenera (ciota ciara) and cavallo cave. in addition, new specimens were discovered in new localities: spinadesco, campoverde and de nadale cave. 3.1. altamura known as “altamura man”, the skeleton from the karstic cave of lamalunga, near the town of altamura in puglia, was accidentally discovered by a group of speleologists in october 1993 (pesce delfino & vacca, 1993). the skeleton is the only human specimen found in the cave, apparently not associated to any lithic artifact throughout the karstic system. the skeleton is exceptionally preserved and probably complete, even though largely embedded in calcite concretions (lari et al., 2015; di vincenzo et al., 2019). the bones show no signs of transportation, modification or deformation, except for some breakage of postcranial elements due to taphonomic agents; it can be thus inferred that the individual remained trapped in the karstic system and died right in the place of deposition, where it is still preserved (fig. 4). the stable microclimatic condition of the cave may have contributed to the excellent condition of preservation of the bones (di vincenzo et al., 2019; vanghi et al., 2019). due to the difficult context of deposition and the presence of the concretions, in addition to various administrative and management problems, the specimen is still within the cave. systematic studies started only after 2008, leading for the first time to the removal of a small 22 buzi c. et al. skeletal element, its gm morphometric analysis, a genetic mtdna characterisation, and an accurate u/th dating that suggested an age bracketed between 172±15 and 130.1±1.9 ka (lari et al., 2015); this point out the altamura skeleton as one of the oldest neanderthals. another research led to the virtual reconstruction of the right scapula (fig. 4, c), starting form three fragments that were sampled for the main purpose of paleogenomic analyses. the reconstruction showed that altamura exhibits a bisulcate/ventral pattern of the axillary border of the scapula. this is a feature that is uncommon for the neanderthals and, more in general, among the archaic humans of the middle and late pleistocene in europe, but for a low frequency of this feature in the sample from krapina in croatia. this observation suggests a phenetic connection between the italian specimen and the early neanderthals of the adjoining balkan region (di vincenzo et al., 2019). further studies have been performed in situ until now, in the framework of a project entitled "rediscovering altamura: advanced multidisciplinary investigations on the skeleton from the lamalunga cave, italy (the k.a.r.s.t. project; prin 2015wphscj)" directed by one of us (gm). waiting for the possibility to extract the bones from the depths of the karstic complex, the researchers have been collecting data directly into the cave, with the aid of telemanipulated cameras, high-resolution videoscopes, laser scanners and x-ray portable machines. this new generation of studies will give rise soon to a series of papers, dealing with both the skeleton and the micro-environment of the cave, starting from the so far unpublished dental evidence pertaining to this neanderthal (riga et al., 2020). 23 the pre-modern human fossil record from italy fig. 4 the cranium of the altamura skeleton: a) its position inside the lamalunga cave; b) digital acquisition of the occipital bone performed in situ during the new campaigns of study started in 2008; c) the extracted scapular fragments and the digital reconstruction of the right scapula (modified from di vincenzo et al., 2019). it must be added that the completeness of the skeleton from altamura include also some skeletal elements that are absent from the previous human fossil record, such as for instance the very delicate bones of the nasal cavity. the possibility to virtually study the inner nasal region, as well as other skeletal districts, by using the most innovative technologies and methods promises to greatly contribute to shed light on the neanderthal evolution. 3.2. spinadesco the adult frontal bone nicknamed “pàus” (manzi et al., 2014; tuniz et al., 2014) was found in 2009 near the small town of spinadesco, cremona, at the current left bank of the po river (hence the nickname). the fossil was discovered in alluvial deposits with the following approximate geographic coordinates: 45° 08' 09.4" n, 9° 53' 42.7" e. the specimen (fig. 4) shows signs of transportation and the place where it was found clearly is not its primary deposition. therefore, at present, it has not been possible to estimate a reliable dating for it. nevertheless, the morphology of the frontal squama and the supraorbital torus shows interesting traits that are similar to archaic neanderthal frontal bones like those from lazaret (de lumley et al., 2018) and biache saint-vaast (guipert et al., 2011), both dated to the final part of the middle pleistocene: about 190-170 ka (valensi et al., 2013) and 200-150 ka (sommé et al., 1988), respectively. a detailed comparative study of the specimen will allow further observations and conclusions. 3.3. fenera ciota ciara the cave of ciota ciara opens on the western slope of monte fenera (piedmont, north-western italy) at 670m above sea level. three human specimens are listed in the catalogue, represented by the squamous portion of a right temporal bone (ciota ciara 1; mottura, 1980) and two permanent teeth (ciota ciara 2 and 3). the temporal fragment was recovered among the material deriving from sediments reworked by uncontrolled excavations carried out in 1955-'56, while the right mandibular molar (ciota ciara 2) and the right maxillary premolar (ciota ciara 3) were found in 1989 in the eroded surface of the mousterian deposit near the entrance to the site (villa & giacobini, 1996). since 2009, research on the site has been resumed under the direction of the university of ferrara and regular excavation campaigns have been conducted since then. the new research activity has led to the complete revision of the geoarchaeology and sedimentology of the cave (arzarello et al., 2012; angelucci et al., 2019; daffara et al., 2019). in addition, new fragmentary human remains have been discovered: a portion of occipital bone and a permanent lower incisor in 2019; a canine and a maxillary molar in 2020 (j. arnaud and m. arzarello, personal communication). the human remains were recovered from the same mousterian level and they are currently under study. 3.4. saccopastore the scenario of human evolution viewed from italy, as attested in most part of the peninsula, becomes more relevant when homo neanderthalensis is considered. latium, corresponding to the tyrrhenian side of central italy, west of the apennines, has yielded notable examples of the morphological progression from the so-called "ante-neanderthals" and "pre-neanderthals" (homo heidelbergensis) to the so-called "classic" morphotype of the species homo neanderthalensis, well represented by the renowned neanderthal cranium from monte circeo, referred to as guattari 1 (e.g., various papers in piperno & scichilone, 1991; marra et al., 2020). a locality in the north-east countryside of the city of rome was known in the past as saccopastore. in 1929 a neanderthal cranium was accidentally found at saccopastore, within a gravel quarry by the workers (sergi, 1929). in the same site, six years later, a second and less complete cranium was discovered by alberto carlo blanc and henri breuil (breuil & blanc, 1936) and led to an excavation campaign in 1936, which brought to light faunal remains and mousterian tools (blanc, 1942). after world war ii, the development of the city has totally cancelled the site; the locality of saccopastore is now lost among the suburbs of rome. both the neanderthal specimens from rome, saccopastore 1 (scp1) and 2 (scp2), were studied for decades by the anthropologist sergio sergi, together with other specimens, most notably the typical neanderthal guattari 1 (sergi, 1929, 1944, 1948, 1962). he reached the conclusion that the neanderthals from saccopastore represent a good example of the combination between archaic and derived features preceding the advent of the "classic" neanderthal, to the point that he proposed a name for a distinct subspecies: homo neanderthalensis aniensis (sergi, 1936). more recently, similar conclusions have been reached by other authors, with the application of new methods and techonologies (condemi, 1992; bruner & manzi, 2006, 2008; bruner et al., 2006; manzi & giacobini, 2018), consistently with the accretion model theory (dean et al., 1998; hublin, 2000, 2002) stating the gradual accumulation of neanderthal traits in europe during the middle and early late pleistocene. the archaic morphology of the two crania from saccopastore is consistent with the proposed dating of about 120 ka (mis 5e) made by several authors (blanc, 1948; segre, 1948; caloi et al., 1998). a recent reassessment of the aggradational succession in the area of rome, including the aniene valley in the northern part of the city, stratigraphically suggests for the site a dating to mis 7, that is to about 250 ka (marra et al., 2015); this is also consistent with the morphology of the two crania from saccopastore, viewed in the light of the accretion model hypothesis. 3.5. campo verde a large number of lower paleolithic stone artifacts and fossil vertebrates were exposed in a trench excavated for the modification of a canal in locality campoverde (formerly campo verde, 41° 32' 16.8" n, 12° 45' 22.6" e), about 45 km south of rome. faunal remains include many large mammals (palaeoloxodon antiquus, mammuthus ex gr. chosaricus-primigenius, ursus spelaeus, canis lupus, equus ferus, equus hydruntinus, stephanorhinus cf. s. hemitoechus, hippopotamus cf. h. amphibius, megaloceros cf. m. giganteus, 24 buzi c. et al. cervus elaphus, dama dama cf. d. d. tiberina, capreolus capreolus, bos primigenius). the lithic assemblage shows similarities with that from casal de’ pazzi and it is characterized by the absence of levallois technique (marra et al., 2018). the age for the terrace of the campoverde complex is constrained by the 40ar/39ar age to 129±1 ka (marra et al., 2018). mazza and colleagues (1992) described a human deciduous right upper second molar, which was not included in the catalogue. only the crown is present, as the tooth is broken below the cemento-enamel junction and a flake of enamel is missing on the buccal face of the paracone. the occlusal surface is square in outline. the mesio-distal diameter is 9.4 mm, the bucco-lingual diameter is estimated in 10.2 mm. a carabelli pit is recognizable. the tooth shows a high degree of wear on all the four cusps. on the base of the presence of an interproximal wear facet, the individual was estimated to be of 8-9 years of age (mazza et al., 1992). the repository of the tooth, as well of the faunal and lithic remains, is the museum “antiquarium comunale” of nettuno. 3.6. taddeo four fossil human teeth were discovered in 1967 at taddeo cave, near marina di camerota (salerno, south-western italy). the layer the teeth come from has been attributed either to mis 5c or 5d or to mis 5a (benazzi et al., 2011). benazzi and colleagues (2011) provided a revised morphological description and morphometric comparisons of these middle paleolithic remains, by using quantitative assessment of the internal morphology with the aid of micro-ct imaging. the tooth taddeo 1 was previously considered either an upper right canine or a lower right canine, while the new analysis identified it as a lower left canine. similarly, the tooth taddeo 2 has been reclassified as a right p4 instead of a right p3. based on the occlusal and interproximal wear, the new analysis also shown that taddeo 2 and taddeo 3 (right m1) belonged to the same individual. all teeth show characteristic neanderthal features of the crown (benazzi et al., 2011). 3.7. tagliente the two decidous teeth recovered in the mousterian deposits (levels 36 and 37) of tagliente shelter (stallavena di grezzana, verona, north-eastern italy) were re-examined by arnaud and colleagues (2016a). the upper right second deciduous molar labelled tagliente 3 shows typical neandertal derived features (e.g. large hypocone and complex topography of the enameldentine junction). the lower left deciduous canine labelled tagliente 4 falls in the range of the neandertal variability for its bucco-lingual diameter. in terms of tissue proportions both teeth fall within the neandertal range of variation: tagliente 3 for the enamel thickness distribution and tagliente 4 for the volume of the crown dentine (arnaud et al., 2016a). 3.8. broion the cave of broion (vicenza, north-eastern italy) is figured in the italian catalogue of 2005 as well as in the “catalogue of fossil hominids” (oakley et al., 1971), because of the presence of fragmentary cranio-dental and postcranial fossilized human remains, found in 1951 within epigravettian levels. recently in a shelter close to the cave and named “riparo broion” a human tooth was retrieved from a late mousterian level and investigated by morphometric and paleogenetic analyses (romandini et al., 2020). the tooth is an exfoliated right upper deciduous canine, and its general morphology and enamel thickness distribution support the attribution to a neanderthal child, confirmed by the mitochondrial dna sequence. the site of riparo broion preserves a stratigraphic sequence also documenting the middle-toupper paleolithic transition, in particular the final mousterian and the uluzzian cultures. the radiocarbon dating of the tooth points to approximately 48 ka cal., as the most likely minimum age (romandini et al., 2020). romandini and colleagues (2020) labelled the mousterian tooth as “riparo broion 1” causing some confusion with the epigravettian material known as “broion 1”. here, we propose to continue the numeration introduced in the catalogue of 2005 for the archaeological area of broion and therefore to name the mousterian tooth as broion 2. 3.9. de nadale the de nadale cave (45°25'16.3"n 11°29'23.1"e) is a new middle palaeolithic site located in the berici hills (north-eastern italy). a single anthropic layer (unit 7) was recovered between sterile levels. unit 7 has yielded a faunal assemblage mostly composed of cervids, bovids with some carnivores. both macro-mammal and micro-mammal assemblages reflect a landscape dominated by open forests and grasslands in a generally cold-temperate climatic context (arnaud et al., 2016b). the lithic assemblage made on flint has been attributed to the quina mousterian. recent chronometric data based on uranium-series (u-th) on a sample of herbivore teeth from unit 7 has provided a minimum age of 70.2 11/20.9 ka (jequier et al., 2015). from unit 7 comes a lower first deciduous molar which has features frequently observed in neanderthal (i.e., incipient tuberculum molare, marked mesial marginal ridge and welldeveloped mid-trigonid crest connecting the protoconid and the metaconid, deep anterior fovea). the observed presence of small pit on the enamel surface could be correlated to incipient caries (arnaud et al., 2016b). 3.10. fumane the site of fumane cave also known as “stazione della neve” or “riparo solinas“, near the village of fumane (western lessini mountains, northern italy) contains a stratigraphic sequence spanning the middle to early upper paleolithic. the uppermost mousterian deposits of fumane cave are grouped into nine stratigraphic units, labelled from bottom to top as a13 to a5 (peresani et al., 2008). the human fossil sample reported in the catalogue of 2005 consists of two middle palaeolithic (fumane 1 and 2) and one upper paleolithic proto-aurignacian (fumane 2) teeth. additional teeth were recovered during excavations from 1989 to 2011 from the mousterian (fumane 4, 5) and uluzzian (fumane 6) levels of the cave. all human remains except for fumane 6 are deciduous teeth. the fumane sample was analysed by benazzi and colleagues (2014). based on metric data (crown and cervical outline 25 the pre-modern human fossil record from italy analysis, and lateral enamel thickness) and non-metric dental traits (e.g., mid-trigonid crest), fumane 1 (redescribed as a lower left second deciduous molar) falls within the neanderthal variability. fumane 4 is described as upper right central deciduous incisor and fumane 5 as lower right lateral deciduous incisor. fumane 6, a fragment of a permanent molar, does not show any morphological features useful for taxonomic discrimination. peresani and colleagues (2013) described the presence of an ochered fossil marine shell (aspa marginata) from the mousterian unit 9 of fumane cave dated to at least 47.6-45.0 ka cal. 3.11. cavallo the cavallo cave (grotta del cavallo) is located near nardò (lecce, south-eastern italy) on the rocky coast of the uluzzo bay. the cave is a paleolithic site where three human teeth have been discovered. these are reported in the catalogue of 2005 (giacobini & manzi, 2005) and are respectively a neanderthal deciduous molar (lower left second, cavallo a) and two early modern deciduous molars (an upper left first, cavallo b, and an upper left second, cavallo c). cavallo a comes from the mousterian stratum, while cavallo b and c come from the uluzzian layer (benazzi et al., 2011, 2012; palma di cesnola & messeri, 1967). in 2013, another new human deciduous incisor (cavallo d) has been recovered in a mousterian sublayer of the site and dated by 14c to a time range of 45.642.9 ka cal. a morphological assessment of cavallo d identified neanderthal features, among which the size and the relative thickness of the enamel. in addition, cavallo d represents the most recent neandertal human remain in southern italy related to a radiocarbon dated stratigraphy (fabbri et al., 2016). 3.12. san bernardino and mezzena the mid-palaeolithic site of san bernardino cave (berici hills, veneto, north-eastern italy) appears in the catalogue of 2005 because of three human remains (both cranio-dental and postcranial) unearthed in 19861987 from the macro-unit ii, which represents mousterian layers dated at > 40 ka (alciati & vacca, 2005). recently, a taxonomic reassessment by benazzi and colleagues (2014) has been carried out on a lower right third molar from the site (san bernardino 4) by crossing various methodologies (e.g. morhometrics, adna, mtdna, isotopic analyses, ams), and it has been ultimately identified as belonging to a modern human, while a 14c dating attributed it to the middle ages. the same conclusions have been obtained for the other human remains. these were modern human remains postdeposited in the mousterian levels (benazzi et al., 2014) and thus must be removed from the italian human fossil record and the relative catalogue. a similar case is that of mezzena shelter (lessini mountains) from the same region. the site is cited in a very short note at the end of the catalogue because of human cranial fragments associated to mousterian lithic assemblages. in the catalogue is highlighted the problematic context of the site and no specific characterisation is reported for the remains. nevertheless, the materials have been recently revised and resulted to belong to a neolithic burial (talamo et al., 2016). the site must be thus removed from the catalogue. 26 buzi c. et al. fig. 5 views of the so-called "devil’s trail" of roccamonfina. two different trackways from the ichnosite near foresta (campania): left, the trackway b and on the right the pathway p1 (modified from avanzini et al., 2020). 4. an ichnosite: foresta (roccamonfina) the foresta ichnosite in the municipality of tora and piccili (caserta, south-western italy), also known as ‘devil’s trails’ (fig. 5), was briefly described in the notes at the end of the catalogue of 2005. further research added new information to that reported there, which was mainly based on first report of this spectacular site (mietto et al., 2003). panarello and colleagues (2020) described new footprints larger than those already studied, which form a new trackway that moves in the opposite direction with respect to the others. all mammal and human footprints (trackways a-e and isolated elements) have been found on top of the ls7 pyroclastic unit, which is dated around 345-350 ka, that is to the cold stage mis 10 (scaillet et al., 2008; santello 2010). panarello and colleagues (2020) also reported the discovery in the thin layer at the base of ls8 and in the surroundings of the foresta of basalt artefacts of mode 2. at least another palaeolithic ichnosite is present in italy inside the “hall of misteries” (sala dei misteri), in the cave of básura near toirano in liguria (avanzini et al., 2020). the about thirty footprints were dated to about 14 ka cal. (citton et al., 2017; avanzini et al., 2018) and are thus referred to modern humans of the very late pleistocene. 5. a final synopsis as reported in the present overview, since the publication of the catalogue of 2005, much new information has been collected with respect to lower and middle palaeolithic populations thanks to new site discoveries that took place across the italian peninsula, new datings of known sites and specimens and/or the application of innovative methods of investigation. therefore italy, south of the alps, confirms to be a territory of primary importance for the study of the european populations in some of the most crucial phases, in particular with respect to the appearance of the mode 2 technology and the diffusion of homo heidelbergensis, the subsequent evolution of homo neanderthalensis and the transition between the middle and upper palaeolithic. particularly, we would underline that some finds of exceptional importance have been studied for the first time or reanalysed thanks to the use of innovative technologies, new methods (especially the geometric morphometrics approach) and the development of new tools offered by the digital imaging. all this new information has significantly modified our knowledge of human evolution in italy and in europe during the pleistocene. further data are coming from new findings, or from old specimens studied through the application of new methodologies. much is also expected from several specimens we cited in this review, that are currently under study. actually, the present reappraisal is intended to be the starting point for a "new catalogue" including the knowledge acquired to date as well as the forthcoming: we expect that in the following years more evidence will be achieved for the reconstruction of the complex patterns of human evolution in europe during the pleistocene, particularly through the study of the italian fossil record and prehistoric sites. acknowledgements as is always the case in literature reviews, a great number of researchers should be recognized for their work, as should their co-workers, the institutions and the competent authorities involved; it is not possible to name them all here, even in the case of the various supports and personal communications the authors of this review received by many colleagues. nevertheless, their names largely appear in the list of bibliographic references as well as in the literature itself. lastly, we thank marco avanzini for the image in fig. 5, julie arnaud and marta arzarello for the information on ciota ciara cave, as well as the editor and the anonymous reviewers for their useful comments. references alciati g., vacca e. (2005) san bernardino. in: catalogue of italian fossil human remains from the palaeolithic to the mesolithic (ed. by alciati g., pesce delfino v., vacca e.). journal of anthropological sciences, 83(suppl.), 131-132. alciati g., pesce delfino v., vacca e., ed. (2005) catalogue of italian fossil human remains from the palaeolithic to the mesolithic. journal of anthropological sciences, 83(suppl.), 1-184. angelucci d.e., zambaldi m., tessari u., vaccaro c., arnaud j., berruti g.l., daffara s., arzarello m. (2019) new insights on the monte fenera palaeolithic, italy: geoarchaeology of the ciota ciara cave. geoarchaeology, 34(4), 413-429. anzidei a.p., bulgarelli g.m., catalano p., cerilli e., gallotti r., lemorini c., milli s., palombo m.r., pantano w., santucci e. (2012) ongoing research at the late middle pleistocene site of la polledrara di cecanibbio (central italy), with emphasis on human-elephant relationships. quaternary international, 255, 171-187. arnaud j., peretto c., panetta d., tripodi m., fontana f., arzarello m., thun hohenstein u., berto c., sala b., oxilia g., salvadori p.a., benazzi s. (2016a) a reexamination of the middle paleolithic human remains from riparo tagliente, italy. quaternary international, 425, 437-444. arnaud j., benazzi s., romandini m., livraghi a., panetta d., salvadori p.a., volpe l., peresani m. (2016b) a neanderthal deciduous human molar with incipient carious infection from the middle palaeolithic de nadale cave, italy. american journal of physical anthropology, 162(2), 370-376. arsuaga j.l., martínez i., gracia a., lorenzo c. (1997) the sima de los huesos crania (sierra de atapuerca, spain). a comparative study. journal of human evolution, 33(2-3), 219-281. arsuaga j.l., martínez i., arnold l.j., aranburu a., gracia-téllez a., sharp w.d., quam r.m., falguères c., pantoja-pérez a., bischoff j., poza-rey e., parés j.m., carretero j.m., demuro m., lorenzo c., sala n., martinón-torres m., garcía n., alcázar de velasco a., cuenca-bescós 27 the pre-modern human fossil record from italy g., gómez-olivencia a., moreno d., pablos a., shen c. c., rodríguez l., ortega a.i., garcía r., bonmatí a., bermúdez de castro j.m., carbonell e. (2014) neandertal roots: cranial and chronological evidence from sima de los huesos. science, 344(6190), 1358-1363. arzarello m., marcolini f., pavia g., pavia m., petronio c., petrucci m., rook l., sardella r. (2007) evidence of early human occurrence in europe: the site of pirro nord (southern italy). naturwissenschaften 94, 107112. arzarello m., peretto c. (2010) out of africa: the first evidence of italian peninsula occupation. quaternary international, 223, 65-70. arzarello m., daffara s., berruti g., berruto g., berté d., berto c., gambari f.m., peretto c. (2012) the mousterian settlement in the ciota ciara cave: the oldest evidence of homo neanderthalensis in piedmont (northern italy). journal of biological research bollettino della società italiana di biologia sperimentale, 85(1). arzarello m., peretto c. (2017) the oldest settlements of the italian peninsula. anthropologie, 121(1-2), 173-178. ascenzi a., segre a.g. (1996) artefacts and human teeth at the fontana ranuccio middle pleistocene site (central italy). anthropologie, 39-46. ascenzi a., biddittu i., cassoli p.f., segre a.g., segrenaldini e. (1996) a calvarium of late homo erectus from ceprano, italy. journal of human evolution, 31(5), 409-423. ascenzi a., mallegni f., manzi g., segre a.g., segre naldini e. (2000) a re-appraisal of ceprano calvaria affinities with homo erectus, after the new reconstruction. journal of human evolution, 39, 443-450. avanzini m., romano m., citton p., salvador i., arobba d., caramiello r., firpo m., rellini i., negrino f., clementi l., zunino m., giannotti s., starnini e., conventi m. (2018) icno-archeology of a human palaeolithic ecosystem: the human and animal footprints in the grotta della basura (toirano, northern italy). alpine and mediterranean quaternary, 31, 39-42. avanzini m., citton p., mietto p., panarello a., raia p., romano m., salvador i. (2020) human footprints from italy: the state of the art. journal of mediterranean earth sciences, 12. belli g., belluomini g., segre-naldini e., cassoli p., cecchi s. (1991) découverte d'un fémur humain acheuléen à notarchirico (venosa, basilicate). l'anthropologie (paris), 95(1), 47-88. benazzi s., viola b., kullmer o., fiorenza l., harvati k., paul t., gruppioni g., weber g.w., mallegni f. (2011) a reassessment of the neanderthal teeth from taddeo cave (southern italy). journal of human evolution, 61(4), 377-387. benazzi s., fornai c., buti l., toussaint m., mallegni f., ricci s., gruppioni g., weber g. w., condemi s., ronchitelli a. (2012) cervical and crown outline analysis of worn neanderthal and modern human lower second deciduous molars. american journal of physical anthropology, 149(4), 537-546. benazzi s., peresani m., talamo s., fu q., mannino m. a., richards m.p., hublin j.j. (2014) a reassessment of the presumed neandertal remains from san bernardino cave, italy. journal of human evolution, 66, 89-94. benazzi s., bailey s.e., peresani m., mannino m.a., romandini m., richards m.p., hublin j.j. (2014) middle paleolithic and uluzzian human remains from fumane cave, italy. journal of human evolution, 70, 61-68. bermúdez de castro j.m., martinon-torres m., gómezrobles a., prado-simón l., martín-frances l., lapresa m., olejniczak a., carbonell e. (2011) early pleistocene human mandible from sima del elefante (te) cave site in sierra de atapuerca (spain): a comparative morphological study. journal of human evolution, 61, 12-25. bermúdez de castro j.m., martinón-torres m., martínfrancés l., modesto-mata m., martínez de pinillos m., garcía c., carbonell e. (2017) homo antecessor: the state of the art eighteen years later. quaternary international, 433, 22-31. biddittu i. (1972) pleistocene e industrie litiche preacheuleane ad arce e fontana liri. quaternaria nova, 16(3). biddittu i. (1974) giacimenti pre-acheuleani di castro dei volsci, frosinone. memorie, istituto italiano di paleontologia umana, n.s., 2, 51-60 bietti a., manzi g. (eds.) (1991) the fossil man of monte circeo. fifty years of studies on the neandertals in latium. quaternaria nova, 1, 9-678. blanc a.c. (1942) i paleantropi di saccopastore e del circeo. i giacimenti, le industrie, correlazione geocronologica. quartär, 4, 1-37. blanc a.c. (1948) notizie sui ritrovamenti e sul giacimento di saccopastore e sulla sua posizione nel pleistocene laziale. paleontographia italica, 42, 3-23. blain h.a., fagoaga a., ruiz-sánchez f.j., bisbalchinesta j.f., delfino m. (2019) latest villafranchian climate and landscape reconstructions at pirro nord (southern italy). geology, 47(9), 829832. breuil h., blanc a.c. (1936) le nouveau crane de saccopastore, rome. l’anthropologie, 46, 1-16. bruner e. (2006) krapina and saccopastore: endocranial morphology in the pre-wurmian europeans. periodicum biologorum, 108, 433-441. bruner e., manzi g. (2006) saccopastore 1: the earliest neanderthal? a new look at an old cranium. in: neanderthals revisited: new approaches and perspectives (ed. by hublin j.j., harvati k., harrison t.). springer, dordrecht, 23-36. bruner e., manzi g. (2008) paleoneurology of an “early” neandertal: endocranial size, shape, and features of saccopastore 1. journal of human evolution, 54(6), 729-742. carbonell e., de castro j. b., arsuaga j.l., diez j.c., rosas a., cuenca-bescós g., sala r., mosquera m., rodríguez x.p. (1995) lower pleistocene hominids and artifacts from atapuerca-td6 (spain). science, 269(5225), 826-830. carbonell e., bermúdez de castro j.m., parés, j.m., 28 buzi c. et al. pérez-gonzález a., cuenca bescós g., ollé a., mosquera m., huguet r., van der made j., rosas a., sala r., vallverdú j., garcía n., granger d.e., martinón-torres m., rodríguez x.p., stock g.m., vergès j.m., allué e., burjachs f., cáceres i., canals a., benito a., díez c., lozano m., mateos a., navazo m., rodríguez j., rosell j., arsuaga j.l. (2008) the first hominin of europe. nature, 452, 465-470. caloi l., manzi g., palombo m.r. (1998) saccopastore, a stage-5-site within the city of rome”. in: “the eemian local sequences, global perspectives, inqua-seqs symposium”, september 1998, kerkrade, netherlands. citton p., romano m., salvador i., avanzini m. (2017) reviewing the upper pleistocene human footprints from the ‘sala dei misteri’ in the grotta della bàsura (toirano, northern italy) cave: an integrated morphometric and morpho-classificatory approach. quaternary science reviews, 169, 50-64. clarke r.j. (2000) a corrected reconstruction and interpretation of the homo erectus calvaria from ceprano, italy. journal of human evolution, 39(4), 433-442. coltorti m., feraud g., marzoli a., peretto c., ton-that t., voinchet p., bahain j.j., minelli a., hohenstein u.t. (2005) new 40ar/39ar, stratigraphic and palaeoclimatic data on the isernia la pineta lower palaeolithic site, molise, italy. quaternary international, 131(1), 11-22. condemi s. (1992) les hommes fossiles de saccopastore et leur relations phylogénétiques. cnrs, paris. daffara s., berruti g.l., berruto g., eftekhari n., vaccaro c., arzarello m. (2019) raw materials procurement strategies at the ciota ciara cave: new insight on land mobility in north-western italy during middle palaeolithic. journal of archaeological science: reports, 26, 101882. dean d., hublin j.j., holloway r., ziegler r. (1998) on the phylogenetic position of the pre-neandertal specimen from reilingen, germany. journal of human evolution, 34(5), 485-508. di vincenzo f., profico a., bernardini f., cerroni v., dreossi d., schlager s., zaio p., benazzi s., biddittu i., rubini m., tuniz c., manzi g. (2017) digital reconstruction of the ceprano calvarium (italy), and implications for its interpretation. scientific reports, 7(1), 1-11. di vincenzo f., churchill s.e., buzi c., profico a., tafuri m.a., micheli m., caramelli d., manzi g. (2019) distinct among neanderthals: the scapula of the skeleton from altamura, italy. quaternary science reviews, 217, 76-88. fabbri p.f., panetta d., sarti l., martini f., salvadori,p. a., caramella d., fedi m., benazzi s. (2016) middle paleolithic human deciduous incisor from grotta del cavallo, italy. american journal of physical anthropology, 161(3), 506-512. falguères c., bahain j.j., tozzi c., boschian g., dolo j.m., mercier n., valladas h., yokoyama y. (2008) esr/u-series chronology of the lower palaeolithic palaeoanthropological site of visogliano, trieste, italy. quaternary geochronology, 3(4), 390-398. garcia t., féraud g., falguères c., de lumley h., perrenoud c., lordkipanidze d. (2010) earliest human remains in eurasia: new 40ar/39ar dating of the dmanisi hominid-bearing levels, georgia. quaternary geochronology, 5(4), 443-451. gavin d.g., fitzpatrick m.c., gugger p.f., heath k.d., rodríguez-sánchez f., dobrowski s.z., hampe a., hu f.s., ashcroft m.b., bartlein p.j., blois j.l., carstens b.c., davis e.b., de lafontaine g., edwards m.e., fernandez m., henne p.d., herring e.m., holden z.a., kong w.s., liu j., magri d., matzke n.j., mcglone m.s., saltré f., stigall a.l., tsai y.h.e., williams j.w. (2014) climate refugia: joint inference from fossil records, species distribution models and phylogeography. new phytologist, 204(1), 37-54. giacobini g., manzi g. (2005) cavallo, baia di uluzzo. in alciati, g., pesce delfino, v., vacca, e. (eds.) catalogue of italian fossil human remains from the palaeolithic to the mesolithic. journal of anthropological sciences, 83(suppl.), 39-40. guipert g., lumley de m.a., tuffreau a., mafart b. (2011) a late middle pleistocene hominid: biache -saint-vaast 2, north france. comptes rendus palevol, 10(1), 21-33. howell f.c. (1957) the evolutionary significance of variation and varieties of "neanderthal" man. the quarterly review of biology, 32(4), 330-347. hublin j.j. (2000) before modern humans: the european perspective. in: the origin of humankind: conference proceedings of the international symposium, venice, 14-15 may 1998 (vol. 3, p. 3). ios press. hublin j.j. (2002) climatic changes, paleogeography, and the evolution of the neandertals. in: neandertals and modern humans in western asia (ed. by akazawa t., aoki k., bar-yosef o.). springer, boston, usa. jéquier c., nicosia c., peresani m., romandini m., delpiano d., joannes-boyau r., lembo g., livrachi a., lópez-garcía j. m., obradović m. (2015) the de nadale cave, a single layered quina mousterian site in the north of italy. quartär, 62, 7-21. lari m., di vincenzo f., borsato a., ghirotto s., micheli m., balsamo c., collina c., de bellis g., frisia s., giacobini g., gigli e., hellstrom j.c., lannino a., modi a., pietrelli a., pilli e., profico a., ramirez o., rizzi e., vai s., venturo d., piperno m., laluezafox c., barbujani g., caramelli d., manzi g. (2015) the neanderthal in the karst: first dating, morphometric, and paleogenetic data on the fossil skeleton from altamura (italy). journal of human evolution, 82, 88-94. lumley de m.a., guipert g., padovani b., quatrehomme g. (2018) les restes crâniens de l’homme du lazaret. frontal laz 24 et pariétaux laz 3, laz 16 et laz 21. in de lumley m.a. (ed.), les restes humains fossiles de la grotte du lazaret. nice, alpes-maritimes, france. des homo erectus européens évolués en voie de néandertali 29 the pre-modern human fossil record from italy sation. cnrs editions, paris. magri d., palombo m.r. (2013) early to middle pleistocene dynamics of plant and mammal communities in south west europe. quaternary international, 288, 63-72. mallegni f., carnieri e., bisconti m., tartarelli g., ricci s., biddittu i., segre a. (2003) homo cepranensis sp. nov. and the evolution of african-european middle pleistocene hominids. comptes rendus palevol, 2(2), 153-159. manzi g., mallegni f., ascenzi a. (2001) a cranium for the earliest europeans: phylogenetic position of the hominid from ceprano, italy. proceedings of the national academy of sciences, 98(17), 1001110016. manzi g. (2004) human evolution at the matuyama‐ brunhes boundary. evolutionary anthropology: issues, news, and reviews, 13(1), 11-24. manzi g., magri d., milli s., palombo m.r., margari v., celiberti v., barbier m., melis r.t., rubini m., ruffo m., saracino b., tzedakis p.c., zarattini a., biddittu i. (2010) the new chronology of the ceprano calvarium (italy). journal of human evolution, 59(5), 580. manzi g., magri d., palombo m.r. (2011) early-middle pleistocene environmental changes and human evolution in the italian peninsula. quaternary science reviews, 30(11-12), 1420-1438. manzi g., bernardini f., caramelli d., cremaschi m., di vincenzo f., galli c., giacobini g., gigli e., lari m., lo vetro d., martini f., muscolino f., persico d., poggiani keller r., profico a., ravara s., ravazzi c., zanolli c., tuniz c. (2014) the hominin frontal bone recently discovered in the po valley, northern italy. conference communication. in: “proceedings of the european society for the study of human evolution”, 18th to 20th september 2014, florence, italy. manzi g. (2016) humans of the middle pleistocene: the controversial calvarium from ceprano (italy) and its significance for the origin and variability of homo heidelbergensis. quaternary international 411, 254-261. manzi g., giacobini g. (2018) lazaret 24 et la documentation humaine fossile en europe entre les stades isotopiques 7 et 5: vers une revaluation de homo neanderthalensis aniensis sergi, 1934. in: les restes humains fossiles de la grotte du lazaret. nice, alpes-maritimes, france. des homo erectus européens évolués en voie de néandertalisation (ed. by lumley de m.a.). cnrs editions, paris. marra f., sottili g., gaeta m., giaccio b., jicha b., masotta m., palladino d.m., deocampo d.m. (2014) major explosive activity in the monti sabatini volcanic district (central italy) over the 800 – 390 ka interval: geochronological-geochemical overview and tephrostratigraphic implications. quaternary science reviews, 94, 74-101. marra f., ceruleo p., jicha b., pandolfi l., petronio c., salari l. (2015) a new age within mis 7 for the homo neanderthalensis of saccopastore in the glacio-eustatically forced sedimentary successions of the aniene river valley, rome. quaternary science reviews, 129, 260-274. marra f., petronio c., ceruleo p., di stefano g., florindo f., gatta m., la rosa m., rolfo m.f. salari l. (2018) the archaeological ensemble from campoverde (agro pontino, central italy): new constraints on the last interglacial sea level markers. scientific reports, 8(1), 1-11. marra f., rolfo m.f., gaeta m., florindo f. (2020) anomalous last interglacial tyrrhenian sea levels and neanderthal settling at guattari and moscerini caves (central italy). scientific reports, 10(1), 1-16. mazza p.p.a., moggi-cecchi j., rustioni m. (1992) vertebrate remains from campo verde, latium, central italy. antropologia contemporanea, 15(34), 65-83. mietto p., avanzini m., rolandi g. (2003) human footprints in pleistocene volcanic ash. nature, 422 (6928), 133-133. moncel m.h., santagata c., pereira a., nomade s., voinchet p., bahain j.j., daujeard c., curci a., lemorini c., hardy b., eramo g., berto c., raynal j.p., arzarello m., mecozzi b., iannucci a., sardella r., allegretta i., delluniversità e., terzano r., dugas p., jouanic g., queffelec a., d’andrea a., valentini r., minucci e., carpentiero l., piperno m. (2020) the origin of early acheulean expansion in europe 700 ka ago: new findings at notarchirico (italy). scientific reports, 10(1), 1-16. mottura a. (1980) un frammento di osso temporale di tipo neandertaliano dal monfenera, vercelli (piemonte). antropologia contemporanea iii, 373379. mounier a., condemi s., manzi g. (2011) the stem species of our species: a place for the archaic human cranium from ceprano, italy. plos one, 6 (4), e18821. muttoni g., scardia g., kent d.v., swisher c.c., manzi g. (2009) pleistocene magnetochronology of early hominin sites at ceprano and fontana ranuccio, italy. earth and planetary science letters, 286(1-2), 255-268. nomade s., muttoni g., guillou h., robin e., scardia g. (2011) first 40ar/39ar age of the ceprano man (central italy). quaternary geochronology, 6(5), 453-457. oakley k.p., campbell b.g., molleson t.i. (1971) catalogue of fossil hominids: part ii, europe. british museum (natural history), london. palma di cesnola a., messeri p. (1967) quatre dents humaines paléolithiques trouvées dans des cavernes de l'italie méridionale. l’anthropologie, 71, 249-262. panarello a., palombo m.r., biddittu i., di vito m.a., farinaro g., mietto p. (2020) on the devil's tracks: unexpected news from the foresta ichnosite (roccamonfina volcano, central italy). journal of quaternary science, 35(3), 444-456. parés j.m., pérez-gonzález a., rosas a., benito a., de castro j.b., carbonell e., huguet r. (2006) matuyama-age lithic tools from the sima del elefante site, atapuerca (northern spain). journal of human evolution, 50(2), 163-169. 30 buzi c. et al. pereira a., nomade s., voinchet p., bahain j.j., falguères c., garon h., lefèvre d., raynal j.p., scao v., piperno m. (2015) the earliest securely dated hominin fossil in italy and evidence of acheulian occupation during glacial mis 16 at notarchirico (venosa, basilicata, italy). journal of quaternary science, 30(7), 639-650. peresani m., cremaschi m., ferraro f., falguères c., bahain j.j., gruppioni g., sibilia e., quarta g., calcagnile l., dolo j.m. (2008) age of the final middle palaeolithic and uluzzian levels at fumane cave, northern italy, using 14c, esr, 234u/230th and thermoluminescence methods. journal of archaeological science, 35(11), 29862996. peresani m., vanhaeren m., quaggiotto e., queffelec a., d’errico f. (2013) an ochered fossil marine shell from the mousterian of fumane cave, italy. plos one, 8(7), e68572. peretto c., arnaud j., moggi-cecchi j., manzi g., nomade s., pereira a., falguères c., bahain j-j., grimaud-hervé d., berto c., sala b., lembo g., muttillo b., gallotti r., hohenstein u.t., vaccaro, c., coltorti, m., arzarello, m. (2015) a human deciduous tooth and new 40ar/39ar dating results from the middle pleistocene archaeological site of isernia la pineta, southern italy. plos one, 10 (10), e0140091. pesce delfino v., vacca e. (1993) an archaic human skeleton discovered at altamura (bari, italy). rivista di antropologia, 71(2), 249-257. piperno m., scichilone g. (1991) the circeo 1 neandertal skull. studies and documentation. istituto poligrafico e zecca dello stato, rome. riga a., boggioni m., papini a., buzi c., profico a., di vincenzo f., marchi d., moggi-cecchi j., manzi g. (2021) in situ observations on the dentition and the oral cavity of the neanderthal skeleton from altamura (italy). plos one, accepted. romandini m., oxilia g., bortolini e., peyrégne s., delpiano d., nava a., panetta d., di domenico g., martini p., arrighi s., badino f., figus c., lugli f., marciani g., silvestrini s., menghi sartorio j.c., terlato g., hublin j.j., meyer m., bondioli l., higham t., slon v., peresani m., benazzi s. (2020) a late neanderthal tooth from northeastern italy. journal of human evolution, 147, 102867. rubini m., cerroni v., festa g., sardella r., zaio p. (2014) a revision of hominin fossil teeth from fontana ranuccio (middle pleistocene, anagni, frosinone, italy). journal of human evolution, 77, 204-216. santagata c., moncel m.h., piperno m. (2020) bifaces or not bifaces? role of raw materials in the middle pleistocene. the example of levels e-e1, b and f (610-670 ka) at notarchirico (italy). journal of archaeological science: reports, 33, 102544. santello l. (2010) analysis of a trampled formation: the brown leucitic tuff (roccamonfina volcano, southern italy). phd thesis, university of padova. santucci e., marano f., cerilli e., fiore i., lemorini c., palombo m.r., anzidei a.p., bulgarelli g.m. (2016) palaeoloxodon exploitation at the middle pleistocene site of la polledrara di cecanibbio (rome, italy). quaternary international, 406, 169182. scaillet s., vita-scaillet g., guillou h. (2008) oldest human footprints dated by ar/ar. earth and planetary science letters, 275(3-4), 320-325. scott g.r., maier c., heim k. (2016) identifying and recording key morphological (nonmetric) crown and root traits. in: a companion to dental anthropology (ed. by irish j.d., scott g.r.). wileyblackwell, london, uk. segre a.g. (1948) sulla stratigrafia dell’antica cava di saccopastore presso roma. rendiconti dell’accademia nazionale dei lincei, 345, 743-751. segre a.g., ascenzi a. (1984) fontana ranuccio: italy's earliest middle pleistocene hominid site. current anthropology, 25(2), 230-233. segre a.g., biddittu i. (2009) pléistocène moyen et inférieur dans le latium (italie centrale). l'anthropologie, 113(1), 59-65. sergi s. (1929) la scoperta di un cranio del tipo di neanderthal presso roma. rivista di antropologia, 28, 457-462. sergi s. (1936) die entdeckung eines weiteren schädels des homo neandertalensis var. aniensis in der grube von saccopastore (rom). anthropologischer anzeiger, (h. 3/4), 281-284. sergi s. (1944) craniometria e craniografia del primo paleantropo di saccopastore. ricerche di morfologia, 20/21, 733-791. sergi s. (1948) the palaeanthropi in italy: the fossil men of saccopastore and circeo. man, 48, 61–64 (part i), 76-79 (part ii). sergi s. (1962) the neanderthal palaeanthropi in italy. in: ideas on human evolution, selected essays 1949-1961 (ed. by howells w.w.). harvard university press, cambridge (ma). sommé j., tuffreau a., aitken m.j., auguste p., chaline j., colbeaux j.p., cunat-boge n., geeaerts r., hus j., huxtable j., juvigne e, munaut a.v., occhietti s., pichet p., puissegur j.j., rousseau d.d., van vliet-lanoe b. (1988) chronostratigraphie, climats et environnements. in: le gisement paléolithique moyen de biache-saint-vaast (pasde-calais). stratigraphie, environnement études archéologiques (1re partie) (ed. by tuffreau a., sommé j.). mémoires de la société préhistorique française. société préhistorique française, paris, france. sommer r.s., nadachowski a. (2006) glacial refugia of mammals in europe: evidence from fossil records. mammal review, 36(4), 251-265. stringer c.b. (1983) some further notes on the morphology and dating of the petralona hominid. journal of human evolution, 12(8), 731-742. stringer c.b., hublin j.j., vandermeersch b. (1984) the origin of anatomically modern humans in western europe. in: the origins of modern humans. a world survey of the fossil evidence (ed. by smith f., spencer f.). alan r. liss, new york, usa. talamo s., hajdinjak m., mannino m.a., fasani l., 31 the pre-modern human fossil record from italy welker f., martini f., romagnoli f., zorzin r., meyer m., hublin j.j. (2016) direct radiocarbon dating and genetic analyses on the purported neanderthal mandible from the monti lessini (italy). scientific reports, 6(1), 1-9. tuniz c., bernardini f., caramelli d., cremaschi m., di vincenzo f., galli c., giacobini g., gigli e., lari m., lo vetro d., martini f., muscolino f., persico d., poggiani keller r., profico a., ravara s., ravazzi c., zanolli c., manzi g. (2014) frontal bone of neanderthal morphology recently discovered in the po valley, italy. conference communication. in: “evolution of modern humans from bones to genomes”, 16th to 18th march 2014, sitges, spain. vacca e. (2005) roccamonfina. in alciati, g., pesce delfino, v., vacca, e. (eds.) catalogue of italian fossil human remains from the palaeolithic to the mesolithic. journal of anthropological sciences, 83(suppl.), 165. valensi p., michel v., el guennouni k., liouville m. (2013) new data on human behavior from a 160,000-year-old acheulean occupation level at lazaret cave, south-east france: an archaeozoological approach. quaternary international, 316, 123-139. vanghi v., borsato a., frisia s., howard d.l., gloy g., hellstrom j., bajo p. (2019) high‐resolution synchrotron x‐ray fluorescence investigation of calcite coralloid speleothems: elemental incorporation and their potential as environmental archives. sedimentology, 66(7), 2661-2685. villa g., giacobini g. (1996) neandertal teeth from alpine caves of monte fenera (piedmont, northern italy): description of the remains and microwear analysis. anthropologie, 55-67. wolpoff m.h. (1980) cranial remains of middle pleistocene european hominids. journal of human evolution, 9(5), 339-358. zanolli c., martinón-torres m., bernardini f., boschian g., coppa a., dreossi d., mancini l., de pinillos m.m., martín-francés l., bermúdez de castro j.m., tozzi c., tuniz c., macchiarelli r. (2018) the middle pleistocene (mis 12) human dental remains from fontana ranuccio (latium) and visogliano (friuli-venezia giulia), italy. a comparative high resolution endostructural assessment. plos one, 13(10), e0189773. 32 buzi c. et al. ms. received: november 26, 2020 revised: january 14, 2021 accepted: february 01, 2021 available online: february 25, 2021 base plio-quaternary geological evolution of the high salto river valley (central italy): the marano de’ marsi unit edi chiarini1, marco giardini2, massimo mattei3, felicia papasodaro1, massimiliano porreca3 & laura sadori2 1dipartimento difesa del suolo – geological survey of italy, ispra, roma edi.chiarini@isprambiente.it 2dipartimento di biologia vegetale, sapienza university of rome 3dipartimento di scienze geologiche, roma tre university abstract: chiarini e. et al., plio-quaternary geological evolution of the high salto river valley (central italy): the marano de’ marsi unit. (it issn 0394-3356, 2009). this paper summarizes the results of multidisciplinary researches carried out in a wide span of time on the earliest continental deposits of the high salto river valley. the study led us to characterize sedimentary environments, to analyze their relationships and to propose a chronological attribution. facies are referable to a complex depositional system consisting of a gilbert-type lacustrine delta and of slope-type partly interfingered fan deltas coming from the eastern border of the basin. the geological data collected allowed us to refer the succession to a single sedimentary cycle; in marano de’ marsi area the paleodrainage and progradation directions were also recognized. to better constrain the chronological, paleoclimatic and paleoenvironmental context, detailed investigations have been conducted on pelitic facies of the deltaic-lacustrine system in two sampling sites (an artificial outcrop at marano de’ marsi village and a borehole near borgorose village). paleomagnetic analyses show that marano de’ marsi and borgorose successions have a normal polarity and generally low magnetic susceptibility values. pollen diagrams from both sites mainly record a mid to high elevation forest pollen rain. the existence of trees from different vegetation belts suggests the presence of a well developed mountain system in the surroundings. in the case of marano de’ marsi section, these vegetation phases alternate with sudden, strong and short spreads of temperate and subtropical taxa. these alternations suggest that important climate changes occurred, with cyclical forest variations typical of glacial / interglacial periods of pliocene and early pleistocene. pollen and paleomagnetic data led us to refer both records to the olduvai subchron, at the end of the pliocene; nevertheless, the possibility that the records deposited during the gauss chron cannot be, definitely, excluded. field geological data and magnetic fabric results suggest that the marano de’ marsi unit sedimentation took place in a basin developed under extensional tectonic regime. riassunto: chiarini e. et al., evoluzione geologica plio-quaternaria dell’alta valle del fiume salto: l’unità di marano de’ marsi. (it issn 0394-3356, 2009). il lavoro sintetizza i risultati di studi multidisciplinari condotti, nel corso di numerosi anni, sui depositi continentali più antichi dell’alta valle del fiume salto. attraverso tali studi è stato possibile caratterizzare gli ambienti di sedimentazione e le relazioni fra essi esistenti, oltre che fornire indicazioni cronologiche più precise. il rilevamento dettagliato di terreno ha consentito il riconoscimento delle facies che compongono tali depositi e la ricostruzione della loro distribuzione, permettendone l’attribuzione prevalentemente ad un delta lacustre di tipo gilbert e subordinatamente a delta-conoidi, originati da canaloni o da corsi d’acqua a basso grado di maturità. i dati di terreno raccolti in questo studio fanno ritenere che l’unità di marano de’ marsi rappresenti il risultato di un unico ciclo sedimentario, sebbene molto articolato perché attribuibile ad un sistema deposizionale complesso. nell’area di marano, l’esame dei foreset e delle altre strutture sedimentarie riconosciute ha fornito dati importanti per la ricostruzione del verso del drenaggio e della progradazione del delta. per precisare il quadro paleoclimatico, paleoambientale e cronologico, sono state condotte indagini paleomagnetiche e palinologiche di dettaglio su due successioni affioranti nelle località di marano de’ marsi e borgorose, in corrispondenza delle facies pelitiche del sistema deltizio/lacustre. le analisi paleomagnetiche indicano che entrambe le successioni studiate hanno polarità magnetica normale e valori di suscettività magnetica relativamente bassi, in accordo con la composizione dei sedimenti essenzialmente carbonatica. i record pollinici registrano prevalentemente fasi forestali con elementi di media ed alta quota. la presenza di alberi tipici di diverse fasce vegetazionali suggerisce la presenza di un sistema montano ben sviluppato nelle vicinanze. a marano de’ marsi queste fasi vegetazionali si alternano con espansioni improvvise, consistenti e di scarsa durata di alberi temperati e subtropicali. queste alternanze inducono a pensare che si siano verificati importanti cambiamenti climatici nel periodo considerato, con variazioni forestali cicliche, tipiche dei periodi glaciali/ interglaciali che vanno dal pliocene medio fin quasi alla fine del pleistocene inferiore. l’interpretazione congiunta dei risultati paleomagnetici e palinologici suggerisce l’attribuzione di entrambe le successioni al pliocene. pur non potendo del tutto escludere l’attribuzione al crono gauss (pliocene medio), il confronto con lavori palinologici ottenuti da sedimenti continentali e marini italiani, insieme a considerazioni di geologia regionale, fanno propendere per un’attribuzione di entrambe le successioni al subcrono olduvai (pliocene superiore). i dati geologici e i risultati di anisotropia della suscettività magnetica suggeriscono che la sedimentazione dell’unità di marano de’ marsi sia avvenuta in un bacino sviluppatosi sotto un regime tettonico di tipo estensionale. keywords: deltaic-lacustrine facies; pollen; plant macrofossils; magnetostratigraphy; pliocene; salto valley; central apennines. parole chiave: facies deltizie-lacustri; polline, macrofossili vegetali; magnetostratigrafia; pliocene; valle del salto; appennino centrale. il quaternario italian journal of quaternary sciences 22(2), 2009 325-344 326 e. chiarini et al. 1. introduction a complex interaction among tectonic uplift, normal fault activity, erosional events and depositional episodes characterizes the plio-pleistocene evolution of the central apennines. the main features of the most recent phases of this tectono-sedimentary evolution are generally well known. in the contrast, the definition of the earlier phases needs to be improved, although a general correlation of the sedimentary infill of the main intermountain basins had already suggested (bosi & messina, 1991; bosi et al., 2003). to this aim stratigraphic and sedimentological studies of continental deposits can be usefully integrated with analyses of erosional paleosurfaces and multidisciplinary research. in the high valley of the salto river, near the latium and abruzzi regions boundary, wide outcrops of continental deposits testify the early steps of the plioquaternary evolution of the area; the sediments have been deposited on the margin of or within a lake no more recognizable in the present-day landscape. these deposits have been studied in the framework of the field survey carried out for the sheet n° 367 of the new geological map of italy at a scale 1:50.000 (servizio geologico d’italia, 2005) and of the same sheet of the geomorphological map (servizio geologico d’italia, 2008). the study has been integrated with paleomagnetic and paleobotanic investigations to better constrain the age of the deposits and to define the paleoclimatic and paleoenvironmental context. in this paper we report the main results of these studies and some considerations on the geological and tectonic history of the sedimentary basin. 2. geological and structural setting the studied area is located in the high salto river valley (fig. 1), between the carseolani mts. to the sw, and the mt. velino chain to the ne. these mountain ranges are mainly formed by lower cretaceousmiocene limestones and dolostones, referable to the latium-abruzzi carbonatic platform paleogeographic domain (compagnoni et al., 2005). the siliciclastic deposits overlying carbonatic units, related to the evolution of the apennines tortonian-messinian foredeep basin (bellotti, 1992; cipollari & cosentino, 1995), crop out south-eastward (palentini planes), northward (malito valley) and north-westward (salto lake), but are lacking in this valley sector. along the valley axis and in the nearby area (fig. 2), continental deposits of gravitative, alluvial, and fig. 1 shaded relief of the apennine sector between the fucino and rieti intermontane basins and location of the study area. modello ombreggiato del settore appenninico compreso fra la piana del fucino e la piana di rieti ed ubicazione dell’area in studio. 327plio-quaternary evolution of the high salto river valley ... lacustrine origin occur. they are organized in several depositional cycles and are separated by stratigraphic unconformities related to major erosional events (chiarini et al., 2007; 2008). the oldest continental deposits, described in this study, crop out between marano de’ marsi (aq) and borgorose (ri) villages. in previous studies, they have been attributed to different sedimentary events. in the geological sheet n° 367 “tagliacozzo” (servizio geologico d’italia, 2005), authors described a first alluvial unit and a following succession recording a progressive evolution from an alluvial to a lacustrine environment, unconformably covered with breccias cropping out in the spedino and borgorose areas. all these units have been doubtingly related to the pliocene. busino (1990) and federici (1990) recognized two main depositional events. the first event, messinian or pliocene in age, produced lacustrine clayey sediments (fosso s. martino formation); the second one consists of two formations (torano and marano de’ marsi formations), which correlated each other and referable to the pliocene, composed of several members. bosi & federici (1993) correlated part of these deposits to the first continental cycle of the fucino basin (s. pelino succession of bertini & bosi, 1976 and aielli complex of bosi et al., 1995), ascribed to pliocene. for the general shortage of dating materials, these chronological data are essentially provided on the basis of morphostratigraphic observations and analogies with other successions of central apennines. the salto river valley lies just to the west of the apennines watershed, between the fucino and the rieti basins, and follows regional tectonic lineaments, corresponding to a nw-se fault system with a multiphase tectonic activity (nijman, 1970; bosi et al., 1994; bigi & costa pisani, 2003). during plio-pleistocene a segment of the fault system (salto valley fault), with a main normal fault activity, controlled the location and the evolution of a continental basin (galadini et al. 2000; 2003), in the intermediate segment of the salto valley, where the artificial homonymous lake is presently located (fig. 1). this basin has been mostly obliterated by subsequent tectonic and morphogenetic events. in the high valley the tectonic structure shifts eastward. indeed a morphologically evident fault along the base of duchessa mountain range (mt. velino chain, see fig. 1) shows an en échelon geometry (galadini & messina, 2001; 2004; morewood & roberts, 2001) with the salto valley fault above mentioned. an important activity phase of duchessa mts. fault has caused the individualization and the evolution of the small corvaro intermountain basin (fig. 2), since the early pleistocene according to bosi & federici (1993). these tectonic events induced a dramatic change in the paleogeography of the area. they made it difficult to recognize the sedimentary basin of the oldest continental deposits and the faults responsible for its structuring. nevertheless, available data make it possible to assume that: 1) sedimentary events considered in this paper took place inside an extensional basin; 2) the tectonic structures that controlled the evolution of this ancient basin could be the same as that responsible for the corvaro basin setting. indeed, the tilting of the succession, generally 10° to 30° toward north-east, suggests the localization of the main fault on the eastern basin flank. moreover, the several tectonic elements affecting the studied sedimentary succession are related to extensional tectonic regime, although referable to different phases. nw-se and nnw-sse trending faults confine deposits in a narrow and elongated belt inside the carbonatic bedrock (fig. 2). along the western margin, the contact of the deposits with the meso-cenozoic limestones consists of rectilinear and high-angle faults, segmented by minor transversal faults. along the eastern border, the boundary is generally tectonic as well; only locally, deposits unconformably rest on the calcareous bedrock. these faults could belong to the duchessa mts. fault system, even if they show a moderate morphological evidence (fig. 2). e-w trending minor faults also displace the marano de’ marsi unit. at present, a wide and flat erosional surface (colle vena francesca paleosurface) almost obliterates the offsetting of the above cited faults; it has been recognized at about 950 m a.s.l. on both the marine carbonatic substratum and the deposits examined in the present work (fig. 2). in a preliminary study, chiarini et al. (1997) have shown that the colle vena francesca paleosurface had formed before the corvaro depression setting: in fact it shows considerable displacement across the duchessa mts. fault. the paleosurface results from the complex interaction of depositional events, erosional phenomena and activity phases of faults; centamore & nisio (2002a; b) have related it to the fontanelle surface located in the mid salto valley. therefore, the wide extension of the colle vena francesca paleosurface would highlight its importance in the stratigraphic frame of the area and testifies an important change in the basin subsidence trend. 3. stratigraphic and sedimentological features the succession, named marano de’ marsi unit, crops out discontinuously along the left flank of the salto valley, close to marano de’ marsi village, at altitudes comprised between 959 m and 710 m a.s.l.; it also crops out between torano and borgorose, from 670 m to 951 m a.s.l. (fig. 2). the maximum thickness preserved from erosion is of about one hundred meters. it is composed of lacustrine marls, claystones, siltstones and arenites and by arenites, gravels and conglomerates of fluvial, deltaic and slope environment, which overlay the carbonatic substratum. this continental succession ends with the above mentioned colle vena francesca erosional surface (fig. 2); it is unconformably covered with the alluvial fan systems of teveruara valleys in the torano area and of valle amara in the borgorose area. deposits of younger cycles sedimented after the infilling and dissection of the corvaro basin and have been referred to the glacial phases of upper pleistocene (servizio geologico d’italia, 2008). to collect stratigraphic and sedimentological data, a geological survey was performed at 1:10.000 scale, supported with photo-geological analysis, observations of natural and artificial outcrop sections and of 328 e. chiarini et al. 329 laboratory samples. a great facies variability was observed. the lack of important erosional discontinuities and the interbedding of lithofacies allow us to refer this succession to a single sedimentary cycle. depositional structures described in this paper were mainly referred to a lacustrine gilbert-type delta for the occurrence of the typical three stratigraphic components (bottomset, foreset and topset; fig. 3); secondly they were connected to slopetype fan-deltas with a high gradient. sharp facies variations frequently mark the emergence of faults belonging to the main apennine system or transversal tectonic elements as observed west of marano de’ marsi and near torano. the recognized facies can be grouped into three main facies associations (a, b, c; fig. 2) on the basis of their meaning, relationships and spatial distribution. facies association a this association groups prevailingly ruditic facies referred to the lacustrine gilbert-type delta, because in many cases their differentiation is made difficult by the bad outcropping conditions. conglomerates with carbonatic pebbles, subangular or subrounded, sub-centimeters to centimeters in size widely crop out in the area; the sediments are clast supported, with a pebbly to muddy matrix, cross-bedded to plane-bedded foresets and moderately sorted beds and laminations; massive coarse-grained sandy beds and decimetric to metric pelitic intervals are frequently present. pedorelicts and sequences referable to paleo-channel filling have also been recognized. these facies occur at mt. pago osco and near marano de’ marsi and torano villages (figs. 2, 4 and 5). between torano and colle scarciofano (fig. 5), in the upper portion of the outcropping succession a lenticular body of well stratified sandstones, several meters thick, occurs; it is characterized by parallel and cross bedded laminations, well cemented strata, oxides rich levels, and thin coarse grained horizons from sandfig. 3 longitudinal interpretative cross section of marano de’ marsi area. 1) recent alluvial and colluvial deposits (upper pleistocene olocene); 2) marano de’ marsi unit sub-rounded to rounded coarse grained conglomerates of gilbert-type delta topsets; 3) marano de’ marsi unit subangular to subrounded fine grained conglomerates with arenitic levels (a) of gilbert-type delta foresets; 4) marano de’ marsi unit pelitic and ruditic deposits of gilbert-type delta bottomsets; 5) carbonatic bedrock; 6) boundary: (a) etheropic, (b) erosional of low order, (c) erosional of high order ; 7) fault. sezione interpretativa longitudinale dell’area di marano de’ marsi. 1) depositi alluvionali e colluviali recenti (pleistocene superioreolocene); 2) unità di marano de’ marsi – conglomerati con clasti grossolani, da subarrotondati ad arrotondati, dei topset del delta gilbert; 3) unità di marano de’ marsi – conglomerati a granulometria fine, con clasti da subangolari a subarrotondati, con livelli arenitici (a) dei foreset del delta gilbert; 4) unità di marano de’ marsi – depositi pelitici e ruditici dei bottomset del delta gilbert; 5) substrato carbonatico; 6) contatto: (a) eteropico, (b) erosionale di basso ordine, (c) erosionale di alto ordine; 7) faglia. plio-quaternary evolution of the high salto river valley ... fig. 2 geological sketch map of the study area. 1) quaternary deposits; 2) marano de’ marsi unit (middle?-upper pliocene) alluvialdeltaic deposits of facies association a: fine to coarse grained conglomerates and gravels of gilbert-type delta topsets (a) and foresets with arenitic levels (b); 3) marano de’ marsi unit lacustrine-deltaic deposits of facies association b: marls, marly claystones, siltstones and conglomerates of gilbert type delta bottomsets and frankly lacustrine environment; 4) marano de’ marsi unit slope-type fan deltas deposits of facies association c: breccias with laminated yellow siltstones, calcarenites, marls and claystones; 5) fault; 6) inferred or buried fault; 7) bedding strike and dip; 8) colle vena francesca paleosurface; 9) marano de’ marsi (tore) section; 10) borgorose (fornace dei laterizi) borehole. carta geologica schematica dell’area in studio. 1) depositi quaternari; 2) unità di marano de’ marsi (pliocene medio?superiore) depositi fluvio-deltaici dell’associazione di facies a: ghiaie e conglomerati da fini a grossolani dei topset (a) e foreset con livelli arenitici (b) del delta gilbert; 3) unità di marano de’ marsi – depositi deltizi e lacustri dell’associazione di facies b: marne, argilliti marnose, siltiti e conglomerati dei bottomset del delta gilbert e di ambiente francamente lacustre; 4) unità di marano de’ marsi – depositi di delta conoide dell’associazione di facies c: brecce con siltiti gialle, calcareniti, marne e argilliti laminate; 5) faglia; 6) faglia incerta o sepolta; 7) giacitura degli strati; 8) paleosuperficie di colle vena francesca; 9) sezione di marano de’ marsi; 10) sondaggio di borgorose (fornace dei laterizi). þ 330 stones to fine breccias. in these strata, small remnants of plants in a physiological position are often present. paleocurrents direction, evaluated using foresets geometry and clasts embrication, varies from nw to ne, suggesting a drainage from south to north. this facies have been referred to the frontal part of the gilbert-type delta. coarse grained conglomerates, moderately sorted, poorly stratified, with bedding thickness ranging from 0.5 m to 5 m crop out on top of succession; deposits are clast supported with a pebbly-sandy matrix and pebbles centimeters to pluricentimeters in size, from sub-rounded to rounded. between the ruditic beds decimetric intercalations of finer sediments are present; these consist of thin horizons of claystones and beds of oxides-rich yellow calcarenites, with parallel and cross lamination. the transition to the overlying ruditic beds is given by a decimetric level of fine grained breccias. moulds related to dry up cracks are noticeable between claystones and calcarenites. these deposits extensively crop out in the area between mt. s. angelo and colle scarciofano (figs. 2, 4 and 5) and are interpreted as topset of the gilbert-type delta system, referred to an alluvial or deltaic plain environment. gravel lithology of the facies association is exclusively carbonatic, whereas finer grain-size classes are also siliciclastic. facies association b this facies association is composed of prevailingly pelites, consisting of marls, carbonatic siltstones and silty claystones, with a grey to dark-grey color, massive, poorly stratified to thinly laminated. whitish, light, limy-clayey horizons, rich of fresh water diatoms, are also present. pelitic deposits include conglomerate bodies; in this context the transition from pelitic lithologies to the overlying ruditic beds is sharp and consists of an etherometric gravelly horizon with muddy matrix and thin levels of silty claystones with shell fragments. these deposits crop out northwest of marano de’ marsi village, in valle di tesio locality; they are also present in a narrow belt between the rosa mt. slope and the laduschio mt.-castelvecchio mt. relief, and then in a wide outcrop in the borgorose area. at the base of the saticone mt. slope, the facies association includes intraformational slumps consisting of a close alternation of carbonatic siltstones and clayey marls, deformed by mesofolds and joints. ruditic facies also include carbonatic metric boulders and chaotic facies, as visible at valle di tesio; these elements probably indicate a tectonic instability along the depositional slope. the observed facies have been ascribed either to a frankly lacustrine environment or to a distal portion of the deltaic system (bottomset). fresh water ostracods referable to the genus fig. 4 upper portion of facies association a exposed at mt. saticone near marano de’ marsi. a) outcrop of cross-bedded fine grained conglomerates; b) detail of moderately sorted cross-bedded foresets; c) sedimentological log. 1) cross-bedded fine grained conglomerates of delta-front facies (foresets); 2: poorly stratified, well rounded coarse grained conglomerates of alluvial-deltaic plain facies (topsets); c: clay; s: silt; sa: sand; g: fine gravel; pe: pebble; co: cobble. porzione superiore dell’associazione di facies a esposta al mt. saticone, nei pressi di marano de’ marsi. a) affioramento di conglomerati a granulometria fine e a stratificazione incrociata; b) dettaglio degli orizzonti a stratificazione incrociata moderatamente classati; c) log sedimentologico. 1) conglomerati a granulometria fine e a stratificazione incrociata del fronte deltizio (foreset); 2) conglomerati a clasti grossolani e ben arrotondati, scarsamente stratificati, di piana alluvionale e deltizia (topset); c: argilla; s: silt; sa: sabbia; g: ghiaia fine; pe: ghiaia media; co: ghiaia grossolana. e. chiarini et al. candona s.p. and erpetocypris s.p., gasteropoda fragments and characee thalluses (pampaloni l. & pichezzi r.m., servizio geologico d’italia, personal communication), are observed inside the pelitic sediments. facies association c this facies association consists of breccias with metric and plurimetric bedding or poorly defined strata, containing sub-angular to sub-rounded carbonatic clasts ranging in size from 0.5 to 10 cm, within a sandypebbly matrix. breccias are poorly organized, clast supported or, less frequently, matrix supported; inverse gradations also occur. thin normal graded interbeddings of small sized breccias, laminated yellow siltstones, calcarenites, marls and claystones are present. in some cases these facies rest on top of lacustrine claystones via clastic horizons rich of shell fragments. t h e a s s o c i a t i o n m i g h t i n c l u d e r u d i t i c deposi ts referable to bottomsets of the main gilbert-type delta, for the etheropic relationships between each other and the close facies similarity. it crops out in the area comprised between torano and borgorose villages, where it is locally covered with ruditic facies of the association a. according to sedimentary structures, ascribed either to a mass transport or, less frequently, to tractive flows, and because of the general lack of a clear foreset facies, this association has been referred to slope-type fan deltas which was originated from stream channels of a low order with a very small and steep catchment area. the facies distribution is consistent with a sediment supply from the eastern border of the basin. 4. the studied stratigraphic logs in order to better define the age of the marano unit and to have indications on the paleoclimate that conditioned the sedimentary events, paleomagnetic and paleobotanic investigations have been carried out on fine sediments of two successions (sadori, 2005). a first one, called marano de’ marsi section, is constituted by deposits belonging to the facies association b and referred to a distal portion of the gilbert delta. a second succession has been studied through a 24 m long core, drilled close to borgorose village and therefore called borgorose core. it is characterized by clays and silts referred to a frankly lacustrine environment. 4.1 marano de’ marsi section this section is located in a marginal position of the salto valley, at an elevation of 720 m a.s.l. (fig. 2). the vertically cut surface is about 11 m high. deposits are rather homogeneous and for about 10 meters from the bottom lacking in significant discon331 fig. 5 upper portion of facies association a exposed at colle scarciofano. a) outcrop of rounded coarse grained conglomerates (topsets). b) sedimentological log. 1) stratified sandstones with paralleland cross-bedded laminations of delta-front facies (foresets); 2) cross-bedded fine to coarse grained conglomerates of delta-front facies (foresets); 3) claystones, oxides-rich yellow calcarenites and fine grained breccias; 4) poorly stratified, sub-rounded to rounded, coarse grained conglomerates of alluvial-deltaic plain facies (topsets); c: clay; s: silt; sa: sand; g: fine gravel; pe: pebble; co: cobble. porzione superiore dell’associazione di facies a esposta al colle scarciofano, nei pressi di borgorose. a) affioramento di conglomerati a granulometria grossolana (topset). b) log sedimentologico. 1) arenarie stratificate con laminazioni parallele e incrociate; 2) conglomerati a granulometria da fine a grossolana, a stratificazione incrociata del fronte del delta; 3) argilliti, calcareniti gialle, ricche di ossidi e laminate, e brecce a granulometria fine in intercalazioni decimetriche; 4) conglomerati a clasti grossolani da subarrotondati ad arrotondati, mal stratificati, di piana alluvionale e deltizia (topset) c: argilla; s: silt; sa: sabbia; g: ghiaia fine; pe: ghiaia media; co: ghiaia grossolana. plio-quaternary evolution of the high salto river valley ... formities; they consist of pale to dark grey silty marls and marly claystones and siltstones, with massive to thinly laminated beds and horizons (fig. 6a). sandy oxidized laminae, a few millimetres thick, cross-laminated levels and muddy pebbles, also occur. at the top, a weakly north verging cut surface marks the transition to an intraformational slump of laminated siltstones and marly claystones, including microfolds and fractures. at the base of the section, whitish horizons of particularly light clayey marls with fresh water diatom remnants, crop out. these sediments have been subject of two specific samplings, i.e. paleomagnetic and pollen and macrofossil plant sampling. 4.1.1 paleomagnetic analyses paleomagnetic sampling and laboratory methods in the marano de’ marsi section, we sampled 154, 2.5 cm in diameter, cores (fig. 6). cores have been drilled with a asc-280 gasoline-powered drill and oriented in situ with a magnetic compass. the average stratigraphic distance between the sampled cores was 10 cm, along the whole outcropping section. the uppermost part of the section, below the slumping, was sampled more in detail in order to study the timing relationships between slump and the acquisition of remanent magnetization. most of the paleomagnetic analyses were carried out at the paleomagnetic laboratory of the department of geological sciences of roma tre university, some of them at eth paleomagnetic laboratory of natural magnetism in zurich. in particular, low-field magnetic susceptibility (km) and its anisotropy were measured in the paleomagnetic laboratory of roma tre university using an agico kly-3 kappabridge. successively, the natural magnetic remanence (nrm) was measured using a jr6 spinner magnetometer and a 2g-enterprise squid cryogenic magnetometer at roma tre university and eth zurich, respectively. magnetic susceptibility analyses low-field magnetic susceptibility (km) was measured along the whole section in 10 cm 3 volume specimens. km values include the contribution of all magnetic minerals (diamagnetic, paramagnetic and ferromagnetic grains) present in the sediment in proportion to their susceptibil ity, abundance and grain size. generally, if a sediment contains paramagnetic minerals as common constituents, susceptibility values are not higher than 100-200 x 10-6 si. magnetic susceptibility analysis has been increasingly used in the last few years as a valid proxy for magnetic minerals concentration (verosub & roberts, 1995; dekkers, 1997) and then can be useful to define the presence of climatically induced cyclicity in sedimentary records (for example alternation of carbonates and clays) (dekkers, 1997). in fact, the susceptibility fluctuations is used as a sensitive indicator of temporal variations in terrigenous input which are likely caused in changes of lake/sea level and 332 fig. 6 stratigraphic log of marano de’ marsi section (a) related magnetic susceptibility (b) and natural remanent magnetization (c) profiles. colonna stratigrafica schematica della sezione di marano de’ marsi (a), profili della suscettività magnetica (b) e della magnetizzazione naturale rimanente (c). e. chiarini et al. 333plio-quaternary evolution of the high salto river valley ... erosion of the continental subaereal landscape (rosenbaum et al., 1996). in the marano de’ marsi lacustrine section the magnetic susceptibility values are low in average and range between 14 and 164 x 10-6 si (fig. 6b). in general, they display a small variation in that interval, reflecting stable and constant input of diamagnetic (mainly calcite) and paramagnetic (clay minerals) grains from substrate during the deposition. moreover, this excludes the presence of any volcaniclastic contamination into the paleolake, such as pyroclastic fall products characterized by high content of ferromagnetic grains. volcaniclastic deposits are typical in middle pleistocene lacustrine intermountain basins in central and southern italy (cavinato et al., 1994). in detail, it is possible to see a weak increase in the values from the bottom to the top, in particular from 50 to 600 cm, with values from 14 to 70 x 10-6. this part is also characterized by a weak ciclicity with a frequency of about 20-40 cm for each cycle (fig. 6b). it is likely that this high frequency reflects the alternance of light and brown layers which have relatively major and minor content in carbonate grains respectively (i.e. minor and major content in magnetic grains). higher values are measured between 600 and 780 cm with a maximum value in correspondence of 756 cm. the remnant upper part of the section shows a constant trend up to the contact with the slumping, which is characterized by higher values, about 80-100 x 10-6 si. natural remanent magnetization (nrm) analyses the intensity of the nrm is in the 1-20 x 10-3 a/m range, without any particular variation along the marano de’ marsi section (fig. 6c). the widespread occurrence of diamagnetic and subordinate paramagnetic minerals is also responsible for the relatively low nrm values. as already seen in the susceptibility profile, also nrm profile of fig. 6c shows a constant trend around a mean value of 8.8 x 10-3 a/m and characterized by a ciclicity with a frequency similar to that of susceptibility (see figs. 6b and 6c). moreover, relatively higher values are recorded in the central part of the section between 400 and 800 cm, whereas they are lower in the upper and lower part of it. thermal demagnetisation technique was applied for most of the specimens, whereas alternating field (af) technique was applied only for some representative specimens. in the first kind of measurements the samples were thermally demagnetised with temperature increments of 30 and 50ºc, up to 440-480ºc, whereas in the second treatment the samples were progressively demagnetised in an alternating field (af) up to 100 mt. both measurements revealed valuable, givfig. 7 calculated paleomagnetic declination (a), inclination (b), maximum angular deviation (c) and virtual geomagnetic pole (d) for marano de’ marsi section. variazione della declinazione magnetica (a), inclinazione magnetica (b), massima deviazione angolare (c) e del polo geomagnetico virtuale (d) ottenuto dai dati di declinazione, inclinazione e latitudine. ing the same results. demagnetization diagrams are analysed by principal component analysis (kirschvink, 1980), in order to determine the chrm (characteristic remanent magnetization) directions for each sample. the maximum angular deviation (mad) is generally less than 10°. samples yielding mad>15° were rejected for further analyses. all the characteristic components are plotted on equal area stereographic projection before (in situ) and after correction for bedding tilt (tilting value is 8° toward nne). some representative paleomagnetic data obtained by thermal and alternating field (af) demagnetisations have been shown in sadori et al. (2009). the declination and inclination of the characteristic component (chrm) are projected versus stratigraphic height after application of bedding correction as shown in figures 7a, b. it is evident as the declination of this component is constant in declination around n, whereas the inclination is always positive (i.e. normal polarity) with a mean value of 55°, in agreement with the expected geomagnetic field (gad) direction expected for this locality. the small scatter of data both in declination and inclination is interpreted as due to secular variations of the earth’s magnetic field. no magnetic reversals are present in the investigated section. magnetostratigraphy the declination and inclination obtained for the chrm of each sample were used to calculate the virtual geomagnetic pole (vgp) latitude, yielding a magnetic polarity sequence in the studied section (fig. 7d). positive vgp latitudes indicate normal polarity for the whole section. in the lower part of the section from 0 to 600 cm, the profile of figure 7d indicates a weak drift of calculated vgp from 70°n to 84°n. in the topmost part of the section (the last 15 cm), the data are not reliable because the clay samples are disturbed by the slumping emplacement. the overall magnetic polarity stratigraphy outlined for tore section is well within a normal polarity magnetozone (i.e. olduvai subchron or gauss chron of pliocene age). anisotropy of magnetic susceptibility analyses the measurement of the low-field ams represents a rapid and non destructive method to define the mineral fabric of rocks (e.g., hrouda, 1982). the magnetic fabric has proven to be closely related to the strain ellipsoid in weakly deformed or “undeformed” clay sediments both in compressional and extensional tectonic regimes, and, consequently, it constitutes a valid tool in defining the deformative pattern in weakly deformed fine-grained sedimentary sequences (borradaile & tarling, 1981; kissel et al., 1986; lee et al., 1990; sagnotti et al., 1994; mattei et al., 1999; cifelli et al., 2004). the ams is defined by a second rank symmetric tensor and is represented geometrically by an ellipsoid with principal axes kmax>kint>kmin. the shape of the ams ellipsoids and the degree of the anisotropy can be described by several parameters (see also jelinek, 1981; hrouda, 1982). the magnetic lineation and foliation (at the sample and site scales) are defined as the kmax and the plane normal to the kmin respectively. the ams at both the specimen and the site levels was evaluated using the jelinek statistics (jelinek, 1978). in the case of a sedimentary magnetic fabric, the magnetic foliation is parallel to the plane of sedimentation whereas the magnetic lineation is dispersed on the foliation plane and reflects the hydrodynamic conditions in the depositional basin. in the case of a magnetic fabric induced by tectonic processes, the maximum axis of susceptibility (kmax) is commonly aligned along the direction of maximum stretching in extensional environments (e.g. mattei et al., 1997; cifelli et al., 2004). in extensional environments, it is well documented that the ams of rocks can be imparted during the very early stages of deformation (e.g. cifelli et al., 2004). the ams results of tore section are grouped in seven sites, from the bottom to the top of the section. the degree of anisotropy is generally low, with values of p’ well below 1.10, and the fabric is either oblate or prolate as shown in figure 8 (p vs. t). the shapes of ams ellipsoid are also not well defined with exception of site vs04 (fig. 9), characterized by oblate ellipsoid. the other sites show low anisotropy degree and a large variability in the shape parameter t. a poor defined magnetic foliation has been measured in all the sites. a well defined magnetic lineation, ne-sw oriented, has been recognized in only one site (vs04) from the middle part of the section. in all the other sites the magnetic lineation is generally dispersed on the foliation plane (fig. 9). the overall ams results demonstrate that the investigated deposit is characterized by a magnetic fabric poorly defined because of the low content in 334 e. chiarini et al. fig. 8 anisotropy degree (p) versus shape parameter (t) of all the measured samples of marano de’ marsi section. note the scatter of the data and the low value of p values. grado di anisotropia (p) vs. fattore di forma (t) per tutti i campioni misurati. si noti il grado di anisotropia molto basso e l’alta dispersione dei dati, che testimoniano un fabric magnetico poco definito. 335plio-quaternary evolution of the high salto river valley ... magnetic grains. in fact, the lacustrine section is composed mostly by carbonatic marls which contain extremely few ferromagnetic or paramagnetic grains. the shape of ams ellipsoids is therefore mostly related to sedimentary processes, where the magnetic foliation tends to reflect the deposition plane whereas the scatter of the magnetic lineation is likely related to hydrodynamic conditions of the lake at the moment of deposition. only site vs04, which has the higher km values (i.e. major amount of magnetic grains), is characterized by a well defined magnetic fabric with a ne-sw oriented magnetic lineation. this seems to suggest a stretching direction oriented parallel to the lineation, i.e. nesw, which could be the main extensional direction that has overprinted partially the lacustrine succession during tectonic deformation. 4.1.2 plant microand macrofossils analyses for plant fossils, a continuous column was taken, sampling big blocks of sediment later on subsampled in laboratory every 10 cm for pollen analyses and inspected for macrofossil ones. plant macrofossils preliminary analyses have shown the presence of a number of arboreal taxa: levels with angiosperm fossils are more abundant than those with gymnosperm ones (fig. 10). the fossil compressions/impressions mainly consist of leaves, but also fruits/seeds, woods and cuticles were found. the still provisional fossil list comprehends many angiosperms such as acer cfr. monspessulanum, carpinus cfr. orientalis, engelhardia sp., fagus cfr. sylvatica, hedera sp., liquidambar sp., quercus sp., rosa sp., as well as abies sp. and pinus sp. both engelhardia and liquidambar genera are extinct in europe and have species living only in asia the first, and both in asia and northern/ central america the second. some fossil specimens are shown in figure 11. plant microfossils 61 sediment samples have been analysed every 20 cm (with sampling improving at 10 cm at key depths), but only 57 showed a sufficient pollen content to be plotted in the diagram. known weights (ca. 2 g) of dry sediment were processed in a sterile laboratory, using a standard procedure consisting in hcl (30%), hf (40%) and naoh (10%) chemical attacks to remove both the mineral fraction and the organic matter. lycopodium spore tablets (stockmarr, 1971) have been added to estimate the pollen concentration values. the palynomorphs identification was carried out with a transmitted light microscope at a minimum magnification of 400x. the level of pollen conservation is low, often very low. the grains appear generally to be corroded and crumpled, slowing and making the analysis difficult. the total pollen concentration varied from 1900 to 129,000 pollen grains/g, the arboreal pollen (ap) percentages mainly ranged between 96 and 100%. 56 pollen taxa (with 11 herbaceous taxa in all) were identified. the number of terrestrial spermatophytes pollen taxa per level is between 15 and 39. the highest amount of pollen taxa matches both very low pollen concentration values (3200 pollen grains/g) and the highest percentage values of nap (13%) at 9.80 m. the number of extinct arboreal pollen taxa is high (14). fern spores and algal remains were also identified during routine pollen analyses. synthetical pollen curves are presented in figure 10. the basic sum is composed by all terrestrial spermatophytes (trees, shrubs and herbs), so excluding water plants, ferns and algal remains. for details concerning the pollen identification criteria and definition of pollen types, as well as for a complete pollen diagram see sadori et al. (2009). among gymnosperms pinus haploxylon type (plus cathaya), pinus sylvestris type, cedrus, picea, abies, tsuga, and taxodium type are found with significant values. among angiosperms, herbs are quite absent. dominant angiosperm tree taxa are quercus, zelkova, ulmus, carya and pterocarya (the last two are no longer spontaneously growing in our continent). the presence fig. 9 equiareal projection of ams principal axes for each site. note the well defined magnetic fabric for site vs04. proiezione equiareale dei principali assi dell’ell issoide dell’ams. si noti come il fabric magnetico sia ben definito nel sito vs04. 336 e. chiarini et al. fi g. 10 m ar an o d e’ m ar si (r ie ti, c en tr al ita ly ). p ol le n d ia gr am (s el ec te d ta xa an d gr ou p s) .p ol le n gr ou p s: su b tr op ic al hu m id fo re st (t ax od iu m ty p e, e ng el ha rd ia ,n ys sa ,c fr .r ho ip te le a) ;t em p er at e b ro ad le av ed d ec id uo us fo re st (c ar p in us b et ul us , c ar ya , c as ta ne a, c el tis , c or yl us , h am am el id ac ea e un d iff ., ju gl an s, ju gl an d ac ea e un d iff ., li q ui d am b ar , p te ro ca ry a, q ue rc us ro b ur ty p e, q ue rc us ce rr is ty p e, ti lia , u lm us , z el ko va ); m id to hi gh el ev at io n fo re st (a b ie s, c ed ru s, p ic ea , ts ug a, b et ul a, fa gu s) ; sc le ro p hy llo us fo re st (q ue rc us ile x ty p e, o le a) ; xe ric el em en ts (h er b s an d e p he d ra ). m ar an o d e’ m ar si (r ie ti, ita lia ce nt ra le ). d ia gr am m a p ol lin ic o (ta xa e gr up p is el ez io na ti) . g ru p p ip ol lin ic i: fo re st a um id a su b tr op ic al e (ti p o ta xo d iu m , e ng el ha rd ia , n ys sa , cf r. r ho ip te le a) ; fo re st a te m p er at a d il at ifo gl ie d ec id ue (c ar p in us b et ul us , c ar ya , c as ta ne a, c el tis , c or yl us , h am am el id ac ea e in d iff ., ju gl an s, ju gl an d ac ea e in d iff ., li q ui d am b ar , p te ro ca ry a, q ue rc us tip o ro b ur , q ue rc us tip o ce rr is , ti lia , u lm us , z el ko va ); fo re st a m on ta na e su b m on ta na (a b ie s, c ed ru s, p ic ea , ts ug a, b et ul a, fa gu s) ; fo re st a a sc le ro fil le (q ue rc us tip o ile x, o le a) ; el em en ti xe ric i( er b e ed e p he d ra ). 337plio-quaternary evolution of the high salto river valley ... of pollen of subtropical taxa as nyssa, cfr. rhoiptelea, liquidambar, engelhardia is worth being mentioned (fig. 12). in the studied pollen record gymnosperms are prevailing, even if four main important, sudden and short angiosperm arboreal pollen oscillations can be observed, the oldest of which being more marked. the importance of these changes can be singled out examining the diagram of figure 10, where pollen taxa, generally found in very different environments, ranging from mountain to arid ones, passing through temperate, subtropical, and mediterranean types, have also been grouped into five “ecological groups”. the more widespread vegetation types are two, one comprehending trees typical of temperate broadleaved deciduous forest and the other trees of mid to high elevation forest. due to the wide ecological range of living pinus species and to the fact that both pinus pollen types comprehend other genera (e.g. pinus haploxylon type includes in this paper also other genera such as cathaya; in fact, for the low degree of pollen grains, preserving its methodical distinction was not possible), pinus was not inserted in the ecological groups (sadori et al., 2009). the main vegetation changes do not consist in alternations between open and close vegetation formations, that is to say between forests and steppe formations, but just in changes in the forest composition, as xeric elements are quite absent. the rapid and consistent alternations found in the pollen record, generally speaking between conifer forests and deciduous angiosperm ones, induce to consider that consistent changes in vegetation occurred. in northern italy arboreal phases with gymnosperms and angiosperms alternately dominating characterized the glacial/interglacial cycles since the gelasian (bertini, 2003). in southern coastal italian areas, however, such cycles were featured by the alternation between steppic and arboreal phases (combourieu-nebout et al., 2004). more marked glacials/interglacials oscillations and a difference in their periodicity occurred only in the last 1 million years (leroy, 2007; raymo et al., 1997; ruddimann et al., 1989), when a change in the pattern of the orbitally driven cycles from obliquity to eccentricity occurred. these physiognomic vegetation changes are however very strong, as the forest cover changed from a mountain forest to a temperate/subtropical one. in these forest changes, temperature and not humidity, seems to have been the main limiting factor. this was not the case of the vegetation changes from glacial to interglacial periods, which occurred in the last million of years and that were mainly triggered by changes in water availability. thus, the record of marano de’ marsi appears to have been mainly deposited during a glacial period. as a matter of fact the so called interglacial periods are represented by very thin sediments horizons, in which the clear vegetation succession typical of these phases are not found (sadori et al., 2009). another substantial aspect of the vegetation recorded in the pollen diagram is that the pollen rain reflects the presence of arboreal taxa requiring different climatic features, and implying the existence of several vegetation belts. it results from the mixing of mountain, mesophilous, and subtropical elements and implies the presence of mountains in the surroundings. the hypothesis that the sediment record from marano de’ marsi has some taphonomical problems has to be advanced: 1) the pollen samples with angiosperm trees dominating show the highest number of taxa and the lowest pollen concentration values. this is in clear contradiction with what happens in the pollen records in which concentration values have been estimated; 2) the vegetation changes between glacials and interglacials are sudden and all intermediate phases are missing; 3) the clear forest vegetation successions typical of interglacial periods are also not found, these phases being recorded, ex abrupto, by mature forests; 4) there is an apparent opposite indication from the macrofossil and microfossil record, as the presence of angiosperm leaves is overwhelming even in phases in which gymnosperm pollen is dominant. the second and the third incongruities were investigated through thin section sediment analyses to check the possibility of important changes in the sedimentation pattern, aimed at explaining possible sediment gaps, not evidenced in the wide outcrop. light lithological changes showed by analyses (cosentino d., roma tre university, personal communication) have been interpreted as disconformities of a low to very low order, ranging from the 0th-order (lamination surface) to the 1st-order (set bounding surface) sensu miall (2006), consistent with the sedimentary environment. the fourth contradiction can be explained with an almost continuous local presence of angiosperms (leaves are too liable to deteriorate if transported far away) by the lake also in periods in which the regional vegetation (and therefore the pollen rain) was dominated by gymnosperms. the vegetation and floristic features of the plant fossils record frame the lacustrine sediment succession between the middle pliocene and the early pleistocene. 4.2 borgorose core the borgorose core has a 24.50 m length and was drilled at an elevation of 725 m a.s.l., close to an outcrop of lacustrine sediments. the sediments, quite homogeneous, are characterized by a higher clay content with respect to those cropping out in the marano de’ marsi investigated section, according to a frankly lacustrine origin; lithologies are mainly massive or thinly laminated marls and silty claystones. 4.2.1 paleomagnetic analyses paleomagnetic samples have been collected every 25 cm on average in order to reconstruct the magnetic susceptibility profile and magnetic polarity of the core and eventually correlate it to marano de’ marsi section. the samples have not been oriented with respect to the geographic north, but they have been marked only with respect to the top of the core. in the borgorose core, the magnetic susceptibility values are generally low and range between 81 and 249 x 10-6 si (fig. 13). these values are relatively higher than marano de’ marsi section because the sediments of borgorose core have a major content of clay minerals (i.e. paramagnetic fraction). the highest values are relative to the upper portion of the core, from 550 to 700 cm, whereas then are constant for the remaining lower portion. 338 fig. 11 marano de’ marsi (rieti, central italy). plant macrofossils. 1. liquidambar sp. 2. acer cfr. monspessulanum 3. quercus sp. 4. fagus cfr. sylvatica 5. engelhardia sp. marano de’ marsi (rieti, italia centrale). macrofossili vegetali. 1. liquidambar sp. 2. acer cfr. monspessulanum 3. quercus sp. 4. fagus cfr. sylvatica 5. engelhardia sp. e. chiarini et al. the paleomagnetic analysis has been performed on 62 out of 84 total samples of the core. all the samples have been thermally demagnetised at paleomagnetic laboratory of peveragno of the university of turin. the same standard techniques described in the previous section have been used to define the principal component and the characteristic remanent magnetization for these samples. the overall results indicate a positive inclination, with an average inclination of 52°, for all the investigated samples, suggesting a normal polarity magnetozone without magnetic reversals. the mean paleomagnetic inclination has been defined without taking into account the tectonic tilting of the succession, that is of about 20°, as measured on the nearby outcrop of the same lacustrine deposits. 4.2.2 plant microfossils pollen samples have been taken every 10 cm from 2.60 to 24.50 m. 41 samples have been analysed, but only 15 (from 3 to 8.60 m) showed a sufficient pollen content to be plotted in the diagram. known amounts of dry sediment (ca. 2 g) have been chemically processed following the treatment illustrated for the marano de’ marsi outcrop. the preservation of the pollen grains was also poor in this record, being generally degraded, corroded and broken, causing problems in the identification. the mean count of only the terrestrial spermatophytes pollen was 304 pollen grains. problems in the pollen preservation are clearly evidenced in the lower part of the core (9-24.2 m) and in the uppermost 3 m. in the related samples the very low pollen concentration values (from 100 to few thousands pollen grains/g) did not allow us to reach significant pollen counting. the total pollen concentration of the selected pollen samples varied from 9000 to 113,000 pollen grains/g at borgorose, with ap (arboreal pollen) percentages ranging from 97 to 99%. synthetical pollen percentage and total pollen concentration curves are presented in figure 14. 46 terrestrial plants pollen taxa (of which 8 herbaceous ones) were identified at borgorose. the number of pollen taxa per level varies from 12 (matching the lowest pollen concentration values) to 31. the diagram does not record either important vegetation changes or a clear vegetation development. gymnosperms pollen always prevails on that of angiosperms. pinus haploxylon type, always dominant, was mainly accompanied by picea, pinus sylvestris type, taxodium type, cedrus, and tsuga. picea, showing percentages between 8 and 19%, can be considered locally present (huntley & birks, 1983). deciduous oaks and carya show high percentage values among the angiosperms, mainly accompanied by fagus, pterocarya, juglans, ulmus, hamamelidaceae, and in minor quantities by engelhardia, nyssa and cfr. rhoiptelea. it is worth mentioning the consistent presence of water demanding trees (riparian plants), possibly indicated by the presence of taxodium type, nyssa, and carya. considering the ecological groups, mid to high elevation forest trees are more abundant than those typical of the temperate broadleaved deciduous forest. subtropical humid forest elements are always present with significant values, while sclerophyllous and xeric elements appear to be less abundant. the sediments are likely to have been deposited during a cool and wet period, and do not show the important angiosperm tree expansions featuring warmer phases. notwithstanding, angiosperms show a continuous and similar behaviour, suggesting that they were present at lower elevations and, possibly, in wet areas (see for example taxodium type) by the lake. the high amount of taxodium type pollen is the main reason for the considerable amount of subtropical humid forest taxa found in the pollen record. four common features can be singled out in the two investigated successions: 1) the scarce number of pollen taxa, that can be partially explained with the very low amount of herbs; 2) the similarity in the pollen lists of the two sites, with 43 pollen taxa in common; 3) the same list of extinct arboreal pollen taxa; 4) the contemporary presence of plants with different ecological requirements, indicating the presence of vegetation belts developed along an altitudinal gradient. similarly for the marano de’ marsi outcrop, a middle/upper pliocene or early pleistocene age appears to be consistent with the palynological data. 5. discussion and conclusions the succession cropping out in the high salto river valley, called marano de’ marsi unit in this paper, has been the object of a few works, differently from successions of fucino and middle salto valley basins. previous authors have interpreted the high salto valley succession as the result of more than one sedimentary event, probably related to pliocene (servizio geologico d’italia, 2005), or to pliocene and to messinian (busino,1990; federici, 1990). stratigraphical and sedimentological data illustrated in this study, on the contrary, allow us to refer the unit to a single sedimentary cycle organized in a complex depositional system. recognized etheropic facies – from alluvial to lacustrine via transitional forms have been referred to a gilbert-type lacustrine delta and to small scale fan-deltas originated from the eastern border of the basin. anomalous sharp facies variations observed in the field have been reported to tectonic activity which significantly displaced the sedimentary unit. two main unconformities bound the unit: the lower one marks the erosional contact with the carbonatic bedrock; the upper unconformity corresponds to the colle vena francesca paleosurface. the prevalence of carbonatic lithologies marks a significant difference with earliest continental deposits of fucino (aielli complex, bosi et al., 1995) and middle salto valley (sabbie di piagge, bertini et al., 1986); in the lower part of the sedimentary successions of these basins, siliciclastic lithologies actually prevail, according to a wide spread of messinian turbidites in the catchment area (bosi et al., 2003) during the first erosional phase of the chain (centamore & nisio, 2002a; b). therefore it is not possible to correlate the marano de’ marsi unit with the fucino and the middle salto valley on the base of lithological affinities. in the framework of a general shortage in chronological data, paleobotanic and paleomagnetic analyses have been conducted on the finer sediments of the marano de’ marsi unit to obtain dating elements, also providing interesting paleoenvironmental and paleoclimatic results. pollen records of the two sampling sites (marano and borgorose) suggest the presence of a well developed mountain system in the surroundings, as indicated by the presence of trees belonging to different vegetation belts. pollen rain coming from mid to high elevation forest taxa is generally prevailing throughout the investigated successions. a pollen assemblage of this kind 339plio-quaternary evolution of the high salto river valley ... fig. 12 marano de’ marsi (rieti, central italy). pollen grains. 1. abies 2. nyssa 3. pterocarya 4. picea 5. cedrus 6. tsuga 7. tilia 8. engelhardia 9. cfr. rhoiptelea 10. carya 11. zelkova. marano de’ marsi (rieti, italia centrale). granuli pollinici. 1. abies 2. nyssa 3. pterocarya 4. picea 5. cedrus 6. tsuga 7. tilia 8. engelhardia 9. cfr. rhoiptelea 10. carya 11. zelkova. faults located on the eastern border of the basin. previously exposed data and the lack of compressive features inside deposits allow us to hypothesize that the marano de’ marsi unit deposited inside an intermountain continental basin, like the pliocene deposits of other basins of central apennines. the erosion of the wide colle vena francesca paleosurface testifies a significant decrease of the subsidence of this basin; during early pleistocene the subsequent settlement of corvaro intermountain basin yields a new subsident area, where the following sedimentation takes place. the whole area indeed is progressively captured by the hydrographic system of the salto river and deposits are consequently dismembered; the outlined evolution is common to that of other basins of the western apennine flank: endorheic at first and then captured and integrated in the drainage network (d’agostino et al., 2001). in reconstructing the fucino basin evolution d’agostino et al. (2001) supposed that the end of the completely internal drainage phase coincided with the capture, during the pleistocene, of a portion of the basin by regressive headward erosion of the salto river. nevertheless, a sediment supply from the eastern border of the basin has also been recognized, the facies distribution and paleocurrent directions testify a main drainage direction i.e. the gilbert-delta progradation from south-east toward north-west, thus trending like the principal fault system. these arguments highlight that at the time of marano de’ marsi unit sedimentation, the fucino and the high salto valley areas belonged to two different, isolated, basins. 340 e. chiarini et al. suggests ascribing the investigated levels to glacial periods (bertini, 2003). nevertheless, pollen typical of temperate forests (and of interglacial periods) is always present in low quantity, and, at times, overwhelming at marano de’ marsi. the moderate expansion of taxa typical of the subtropical humid forest (all extinct at present in europe) is noteworthy and useful for the chronological framing. the similarity of the pollen assemblages induces us to think that the two sediment records were deposited in the same period or at very close times. the plant fossil assemblages, the high amount of taxa at present extinct in italy indicate that the sediments were likely deposited during the middle/upper pliocene or the early pleistocene. as no magnetic reversals are present in the investigated section, the combination of pollen and paleomagnetic data allows to constrain both records to gauss chron (middle pliocene) or olduvai/reunion subchrones (late pliocene). a close comparison (see sadori et al., 2009) with other italian palynological records of pliocene and pleistocene age (urban et al., 1983; arias et al., 1990; suc et al., 1995; bertini, 2000, 2001, 2003) seems to better frame both successions in the subchrones of late pliocene, more likely to olduvai one, for its longer duration. the possibility that the records deposited during the gauss chron cannot be, definitely, excluded. the presence of pliocene continental deposits is widely documented in the central apennines and it has been related mainly to extensional tectonic activity: since pliocene a prevailingly lacustrine sedimentation took place in the main intermountain basins like the turano valley, the middle salto valley and the fucino basins (bosi et al., 1995; bosi et al., 2003; galadini & messina, 2004). intermountain basins in central apennines are thought to be progressively younger eastward, for the effects of extensional tectonic migration from the western sectors to the eastern ones (cavinato & de celles, 1999; galadini & messina, 2004). the quite complex structural setting, outlined in this paper, neither allows us to define the configuration of the basin where the marano de’ marsi unit sedimented, nor to certainly establish which tectonic structures guided the basin settlement. geological field data and ams results suggest that the marano de’ marsi unit was deformed in an extensional tectonic regime, with a stretching direction oriented ne-sw. the development of a gilbert-type delta also implies the occurrence of a steep margin; additionally the presence of slumps and big boulders in some horizons of succession indicate a tectonic instability along the depositional slope, giving value to the tectonic control on the basin evolution. finally the structural setting of succession shows a general ne tilting. all these features are consistent with the activity of fig. 13 stratigraphic log (a) and magnetic susceptibility profile (b) for borgorose core. colonna stratigrafica schematica della sezione di borgorose (a) e profilo di suscettività magnetica (b). 341plio-quaternary evolution of the high salto river valley ... fi g. 14 b or go ro se (r ie ti, c en tr al ita ly ). p ol le n d ia gr am (s el ec te d ta xa an d gr ou p s) .p ol le n gr ou p s ar e lis te d in fi g. 12 . b or go ro se (r ie ti, ita lia ce nt ra le ). d ia gr am m a p ol lin ic o (ta xa e gr up p is el ez io na ti) .p er ig ru p p ip ol lin ic iv ed il ’e le nc o in fi g. 12 . 342 e. chiarini et al. acknowledgments the authors are very grateful to a. bertini and p. messina for the useful discussions and the critical review of the paper and f. cifelli for paleomagnetic sampling. references arias c., bigazzi g., bonadonna f.p., iaccarino s., urban b., dal molin m., dal monte l. & marzolini m. (1990) valle ricca late neogene stratigraphy (lazio region, central italy). paléobiologie continentale 17, 61-68. bellotti p. (1992) i sedimenti terrigeni della depressione del lago salto – tagliacozzo: considerazioni sulla loro successione verticale. boll. soc. geol. it., 103, 311-326. bertini a.(2003) early to middle pleistocene changes of the italian flora and vegetation in the light of a chronostratigraphic framework. il quaternario, 16 (1bis), 19–36. bertini a. (2000) pollen record from colle curti and cesi: early and middle pleistocene mammal sites in the umbro-marchean apennine mountains (central italy). journal of quaternary sciences, 15, 825-840. bertini a. (2001) pliocene climatic cycles and altitudinal forest development from 2.7 ma in the northern apennines (italy): evidences from the pollen record of the stirone section (5.1 to 2.2 ma). geobios, 34 (3), 253–265. bertini t. & bosi c. (1976) sedimenti continentali probabilmente pliocenici nella valle del salto e nella conca del fucino (rieti, l’aquila). boll. soc. geol. it., 95, 767-801. bertini t., bosi c., messina p. & sposato a. (1986) elementi di tettonica compressiva pliocenica nella zona di borgo s. pietro (rieti). mem. soc. geol. it., 35, 547-553. bigi s. & costa pisani p. (2003) the “pre-thrusting” fiamignano normal fault. boll soc. geol. it., 122, 267-276. borradaile g. j. & tarling d. h. (1981) the influence of deformation mechanisms on magnetic fabrics in weakly deformed rocks. tectonophysics, 77, 151-168. bosi c., galadini f., giaccio b., messina p. & sposato a. (2003) plio-quaternary continental deposits in the latium-abruzzi apennines: the correlation of geological events across different intermontane basins. il quaternario, 16 (1bis), 55-76. bosi c., galadini f. & messina p. (1995) stratigrafia plio-pleistocenica della conca del fucino. il quaternario, 8(1), 83-94. bosi c. & messina p. (1991) ipotesi di correlazione fra successioni morfo-litostratigrafiche plio-pleistoceniche dell’appennino laziale-abruzzese. studi geol. camerti, vol. spec. 1991/2, crop11, 27-31. bosi v. & federici v. (1993) la conca di corvaro. in “guida all’escursione alle conche intermontane dell’appennino laziale-abruzzese” (15-18 settembre 1993). il quaternario, 6, 393-395. bosi v., funiciello r. & montone p. (1994) fault inversion: an example in central apennines (italy). il quaternario, 7(2), 577-588. busino m. (1990) – evoluzione geologica pliocenicoquaternaria dell’alta valle del fiume salto, da bocca di teve all’abitato di marano. unpublished degree thesis. università degli studi “la sapienza”, roma. cavinato g. p., cosentino d., de rita d., funiciello r. & parotto m. (1994) tectonic-sedimentary evolution of intrapenninic basins and correlation with the volcano-tectonic activity in central italy. memorie descrittive della carta geologica d’italia, 49, 63–76. cavinato g. p. & de celles p.g. (1999) – extensional basins in the tectonically bimodal central apennines fold-thrust belt, italy: response to corner flow subducting slab in retrograde motion. geology, 27, 955–958. centamore e. & nisio s. (2002a) quaternary geology and morphostructural evolution between the velino and salto valleys. studi geol. camerti, vol. spec. 2002, 37-44. centamore e. & nisio s. (2002b) tettonica e sedimentazione (lias-pleistocene) nella media valle del salto (rieti, italia centrale). studi geol. camerti, 2002/2, 53-70. chiarini e., d’orefice m., graciotti r., la posta e. & papasodaro f. (2008) note illustrative della carta geomorfologica d’italia alla scala 1:50.000. f° 367 “tagliacozzo”. apat servizio geologico d’italia / dipartimento difesa del suolo. chiarini e., giardini m., la posta e., papasodaro f. & sadori l. (2007) sedimentology, palynology and new geochronological constraints on quaternary deposits of the corvaro intermontane basin (central italy). revue de micropaléontologie, 50 (4), 309-314. elsevier. chiarini e., messina p. & papasodaro f. (1997) evoluzione geologica e tettonica plio-quaternaria dell’alta valle del f. salto (italia centrale): primi risultati derivanti dall’analisi delle superfici relitte e dei depositi continentali. il quaternario, 10(2), 625-629. cifelli f., mattei m., hirt a. m. & gunther a. (2004) the origin of tectonic fabrics in “undeformed’’ clays: the early stages of deformation in extensional sedimentary basins. geophys. res. lett., 31(9). combourieu-nebout n., foucault a. & mélières f. (2004) vegetation markes of palaeoclimate cyclical changes in the pliocene of punta piccola (sicily, italy), palaeogeography, palaeoclimatology, palaeoecology 214, 55-56 cipollari p. & cosentino d. (1995) – miocene unconformities in central apennines: geodynamic significante and sedimentary basin evolution. tectonophysics, 252, 375-389. compagnoni b., d’andrea m., galluzzo f., giovagnoli m.c., lembo p., molinari v., pampaloni m.l., pichezzi r.m., rossi m., salvati l., santantonio m., raffi i. & chiocchini u. (2005) note illustrative del f° 367 “tagliacozzo” della carta geologica d’italia alla scala 1:50.000. servizio geologico nazionale, roma. d’agostino n., jackson j.a., dramis f. & funiciello r. (2001) interactions between mantle upwelling, drainage evolution and active normal faulting: an example from the central apennines (italy). geophys. j. int., 147, 475-497. dekkers m. j. (1997) environmental magnetism: an introduction. geol. mijn., 76, 163-182. federici v. (1990) – evoluzione geologica pliocenicoquaternaria dell’alta valle del fiume salto nella zona di borgorose-valle amara. unpublished degree thesis. università degli studi “la sapienza”, roma. galadini f. & messina p. (2001) plio-quaternary changes of the normal fault architecture in the central apennines (italy). geodinamica acta, 14, 321-344. galadini f. & messina p. (2004) early-middle pleistocene eastward migration of the abruzzi apennine (central italy) extensional domain. journal of geodynamics, 37, 57-81. galadini f., messina p., giaccio b. & sposato a. (2003) early uplift history of the abruzzi apennines (central italy): available geomorphological constraints. quaternary international, 101-102, 125-135. galadini f., messina p. & sposato a. (2000) tettonica quaternaria dell’appennino centrale e caratterizzazione delle faglie nel pleistocene superioreolocene. in: galadini f., meletti c., rebez. a. (a cura di), le ricerche del gndt nel campo della pericolosità sismica (1996-1999), cnr-gndc, 181-192 hrouda f. (1982) magnetic anisotropy of rocks and its application in geology and geophysics. geophys. surv., 5, 37–82. huntley b & birks hjb (1983) an atlas of past and present pollen maps for europe: 0-13 000 years ago. cambridge university press, cambridge. jelinek v. (1978) statistical processing of anisotropy of magnetic susceptibility measures on groups of specimens. studia geophisica et geodetica, 22, 50-62. jelinek v. (1981) characterization of the magnetic fabric of rocks. tectonophysics, 79, t63-t67. kirschvink j. l. (1980) the least-squares line and plane and the analysis of paleomagnetic data. geophys. j. r. astr. soc., 62, 699–718. kissel c., barrier e., laj c. & lee t.q. (1986) magnetic fabric in “undeformed” marine clays from compressional zones. tectonics, 5(5), 769781. lee t.q., kissel c., laj c., horng c. s. & lue y.t. (1990) magnetic fabric analysis of the pliopleistocene sedimentary formations of the coastal range of taiwan. earth planet. sci. lett., 98, 23–32. leroy s.a.g. (2007) progress in palynology of the gelasian–calabrian stages in europe: ten messages . revue de micropaléontologie, 50 , 293–308. mattei m., sagnotti l., faccenna c. & funiciello r. (1997) magnetic fabric of weakly deformed clayrich sediments in the italian peninsula: relationship with compressional and extensional tectonics. tectonophysics, 271, 107-122. mattei m., speranza f., argentieri a., rossetti f., sagnotti l. & funiciello r. (1999) extensional tectonics in the amantea basin (calabria, italy): a comparison between structural and magnetic anisotropy data. tectonophysics, 307, 33-49. miall a.d. (2006) the geology of fluvial deposits. sedimentary facies, basin analysis, and petroleum geology. springer, 582p. morewood n. g. & roberts g. p. (2000) the geometry, kinematics and rates of deformation within an en échelon normal fault segment boundary, central italy. journal of structural geology, 22, 10271047. nijman w. (1970) tectonics of the velino-sirente area, abruzzi, central italy. modification of compressional structures by subsequent dilatation and collapse. koninkl. nederl. akademie van wetenschappen. amsterdam. raymo m.e., oppo d.w. & curry w. (1997) the midpleistocene climate transition: a deep sea carbon isotopic perspective. paleoceanography, 12, 546559. rosenbaum j. g., reynolds r. l., adam d. p., drexler j., sarna-wojcicki a. m. & whitney g. c. (1996) record of middle pleistocene climate change from buck lake, cascade range, southern oregon evidence from sediment magnetism, trace-element geochemistry, and pollen. geol. soc. am. bull., 108(10), 1328-1341. ruddiman w.f., raymo m.e., martinson d.g., clement b.m. & backman j. (1989) pleistocene evolution: northern hemisphere ice sheets and north atlantic ocean. paleoceanography, 4(4), 353-412. sadori l. (2005) – studio paleobotanico dei depositi continentali plio-quaternari affioranti nell’area del foglio n. 367 “tagliacozzo” della carta geomorfologica d’ital ia in scala 1:50.000. rapporto inedito. sadori l., giardini m., chiarini e., mattei m., papasodaro f. & porreca m. (2009) pollen and macrofossil analyses of pliocene lacustrine sediments (salto river valley, central italy). quaternary international, doi:10.1016/j.quaint.2009.05.008 . sagnotti l., faccenna c., funiciello r. & mattei m. (1994) magnetic fabric and structural setting of plio-pliocene clayey units in an extensional regime: the tyrrhenian margin of central italy. j. struct. geol., 16(9), 1243-1257. servizio geologico d’italia (2005) carta geologica d’italia alla scala 1:50.000. f. 367 “tagliacozzo”. servizio geologico d’italia (2008) carta gemorfologica d’italia alla scala 1:50.000. f. 367 “tagliacozzo”. stockmarr j. (1971) tablets with spores used in absolute pollen analysis. pollen et spores 13, 615-621. suc j.-p., bertini a., combourieu-nebout n., diniz f., leroy s., russo-ermolli e., zheng z., bessais e. & ferrier j. (1995) structure of west mediterranean vegetation and climate since 5.3 ma. acta z9ool. crac., 38(1): 3-16. urban b., arias c., bigazzi g. & bonadonna f.p. (1983) early pleistocene palynostratigraphy of fornace tini, valle ricca (central italy). palaeogeography, palaeoclimatology, palaeoecology, 41, 153-164. verosub k.l. & roberts a.p. (1995) environmental magnetism: past, present, and future. j. geophys. res. b, 100, 2175–2192. 343plio-quaternary evolution of the high salto river valley ... ms. ricevuto l’8 aprile 2009 testo definitivo ricevuto il 29 ottobre 2009 ms. received: april 8, 2009 final text received: october 29, 2009 amq74 bizzarri et al proofcopy 3 available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 31 (2), 2018, 207 219 archaeo-geosites in urban areas: a case study of the etruscan palazzone necropolis (perugia, central italy) roberto bizzarri, laura melelli, corrado cencetti dipartimento di fisica e geologia, università di perugia, perugia, italy corresponding author: l. melelli <laura.melelli@unipg.it> abstract: in addition to practical and cultural motivations, there is also a geological reason for the establishment of an urban area. in central italy, a large part of the main historical and cultural towns derived from very ancient villages located on hilltops, close to alluvial plains. height guaranteed a healthy environment compared to the lowlands, where wetlands, marshes and flooding favoured malarial conditions. at the same time, proximity to lowlands was essential for accessing communication networks, drinking water availability and raw materials. in most cases, the morphology of these hills has been a decisive limitation for urban development. on the contrary, the pliocene-pleistocene fluvial and lacustrine sediments forming these reliefs have been used for housing some important civil and religious facilities such as houses, storage areas, and tunnels, but also wells and tanks, tombs and necropolises. thus, the central areas of the most important historical cities still preserve valuable archaeological sites. moreover, the original sedimentary deposits can often be observed along the perimetric walls of these buildings, and these sites provide a unique opportunity to reconstruct a 3d geological view. when both archaeological and geological values are high, these sites can be defined as “archaeo-geosites” and offer a unique opportunity for a multidisciplinary study of the urban areas. the etruscan palazzone necropolis in perugia (umbria, central italy) is an ideal case study for this approach. a detailed study of the sedimentological and lithostratigraphic features of the deposits cropping out in the necropolis led to the identification of two distinct, superimposed fluvial systems, separated by a main unconformity, which could be interpreted in terms of different ages and/or changes in the main fluvial regime. a geomorphological overview of the area is also proposed, with the aim of expanding the palaeoenvironmental reconstruction to a larger area, including the perugia hill. finally, the palazzone necropolis, as an archeo-geosite, could be considered as a prototype for the promotion of geotourism in urban areas, contributing to a new added value to conventional touristic tours of cities. key words: geoarchaeology, archaeo-geosite, etruscan hypogeum, umbria, italy 1. introduction geology, in popular opinion, is a scientific discipline associated with natural scenery where abiotic elements of the landscape, outcropping of rocks or landforms are evident. however, nowadays increasing attention is directed towards urban areas as places where the geological component plays an important role both as a fundamental piece in gaining knowledge of the initial settlement and as a constraint for architectural development. on this topic, one main aspect already investigated in the scientific literature involves the natural hazards characterizing some urban areas (bathrellos et al., 2017). hydrogeological instability, such as flood and drought (güneralp et al., 2015) and their increasing impact due to climatic change (christenson et al., 2014) are the most evident aspects of the relationship between human presence and the natural setting. the susceptibility to volcanic phenomena (chester et al., 2000; orsi et al., 2004) or seismic events (carreño et al., 2007) is also fundamental. on the contrary, the geological component may be considered not only a risk factor, but also a resource. traditionally, the most important human settlements have been located in close proximity to drinking water supplies such as underground reserves, and springs, or to fluvial networks used for communication. moreover, accessibility to mineral resources or building materials played a significant part in determining locations for urban placement. the scientific community is nowadays adding a new value derived from the geological features of a site, mostly in urban areas. it is thought that geological information could stimulate touristic interest and attract a growing number of visitors. with this in mind, heritage stones could be a powerful thread for creating touristic itineraries in urban areas and in particular in the historical centres of cities (de wever et al., 2017). the natural stones used for historical buildings, churches, roads and monuments offer unique opportunities to increase the knowledge of the bedrock present under a city and in the surrounding areas (borghi et al., 2014; de wever et al., 2017). especially in the past, it was common to quarry building materials close to the settlements, except for re-using materials or for some buildings of great value for which the building materials might also have come from further distances. in addition, the geological nature of the bedhttps://doi.org/10.26382/amq.2018.15 208 fi g. 1 a ) lo ca tio n m ap o f t he s tu dy a re a in th e r eg io n of u m br ia . t he p er ug ia h ill ( 1) is lo ca te d in th e ti be rin o b as in ( 2) . b ) th e p al az zo ne n ec ro po lis d ev el op s at th e bo tto m o f t he h ill , in si de p le is to ce ne fl uv ia l s ed im en ts . bizzarri r et al. 209 area but rather a set of minor coalescing sub-basins, each one characterized by its peculiar evolution through time and space (pucci et al., 2014). terrigenous sediments of different sizes, from blocks and gravels to sands and clays are arranged in a sedimentary sequence above the bedrock, with thicknesses of even hundreds of meters. the centre of perugia lays entirely on this sedimentary sequence, preliminarily dated between early and middle pleistocene (regione umbria, 2010). the underground cavities are quite numerous, due to the lithological features of the sediments, which are easy to dig. through time, they had different uses, such as wells for groundwater, food remittances, anti-aircraft rigs, and drains to facilitate the flow of groundwater and graves, too. “perugia underground” is located in several parts of the hill, just because everywhere the sediments were easy to work and the only constraint was the topographic and morphological setting. it is possible to see the sediments in their original setting in the majority of these underground cavities. in addition to the lithological composition and the grain size of the sediments, these unique outcroppings allow the spatial pattern of many geological structures to be understood, being the key to rebuilding the palaeogeographic environments of sedimentation. this being so, in many cases these places are an excellent opportunity to link archaeology and geology. in fact, while the archaeological value is already known and promoted, the geological one is still not well highlighted. 2.1. the etruscan civilization in perugia: underground and surface sites the etruscan civilization started in central italy in the first millennium bc (haynes, 2000). during its maximum expansion, it ranged from the po valley in northern italy to the campania region in southern italy. perugia was one of the twelve confederate cities (lucumonie) of the etruria league, because of its strategic geographical position, on the top of a hill overlooking the tiber valley where the main roads towards the neighbouring cities passed through. numerous indications of the etruscan presence, including city walls and artefacts and several necropolises (nati & nardelli, 2010), still offer considerable evidence of the significant signs left by the etruscan people. between the 6th and the 3rd centuries bc great new walls, built using large blocks of travertine, fortified the city. running for almost three kilometres, the walls mark out the highest portion of the hill. there are seven gates in the walls; the etruscan arch (3rd century bc, fig. 2a) is the most famous also because of the two lateral trapezoidal-shaped towers, which, together with the wide arch, render the image of a majestic building. in addition to the city walls, other relevant remains of the etruscan civilization are still present in the city centre. one of the best preserved is the etruscan well (second half of the 3rd century bc, fig. 2b). it is a cylindrical structure with a diameter of 5.6 m in the upper portion and reaches a depth of 37 m. it is covered with a series of travertine slabs, supported by a system of massive stone beams (“trusses”) that rock and the original natural morphological setting have become a new and significant tourist attractor. the experiences of several large cities in the world confirm the potential importance of this approach (reynard et al., 2011; pica et al., 2016; reynard & brilha, 2017). in this study the possibility of using geoarchaeology as a connection between the geological component and the archaeological heritage in urban areas was investigated. geoarchaeology is a multidisciplinary research field, using contents and methods deriving from the earth sciences for investigating archaeological sites. moreover, for cities with a very ancient background, the link between archaeological sites and geological data is even more significant. up to now, the main results of the geoarchaeological approach have been used for archaeological purposes. recently this approach has also provided interesting data for geological research (melelli et al., 2016). for example the techniques used for constructing public or private buildings, as for instance, houses or graves, including underground excavations, and in some cases the perimetric walls offer unique opportunities to develop a 3d view of rocky outcrops. archaeological sites are points of interest for geological knowledge to such an extent so as to be classified as archaeo-geosites (melelli et al., 2016). in this study the etruscan palazzone necropolis (perugia, umbria region, central italy) was investigated in order to highlight its potential as an archaeo-geosite and to be considered as a prototype for other similar sites. 2. perugia hill town: the ideal site linking geology and archaeology perugia (region of umbria, central italy) is located along the western edge of the tiberino basin, the largest intermountain basin in umbria (about 1800 km2) and one of the largest in central italy (fig. 1a). perugia stands on a triangular-shaped hill with a maximum altitude of about 493 m a.s.l. and covers about 27 km2 (fig. 1b). observing the hill from above, five main ridges spread towards the ne, e, sse, sw, w, resembling the five fingers of a hand. the ridges decrease in altitude as they reach the tiber river valley, flowing at the foot of the hill towards the ssw. the historical centre of the town is located at the apex of the triangle, on the highest part of the hill. at its highest point, the early shape of the hill was a saddle between two peaks facing the steep slopes below. that morphology favoured the first villanovan settlements around the 11th-10th century bc. it is at the very top of the hill that the most important witnesses of the past civilizations (etruscan: 6th-3rd century bc; roman: from 1st century bc) occur. at the bottom of the hill there are still precious historical remains, too. the tiberino basin, crossing the entire region from north to south with an upside down y shape, close to perugia splits into two branches, both with a n-s direction (ambrosetti et al., 1995). the basin is the consequence of extensional tectonics, started in the pliocene, and is still active in the area. the basin, filled by fluvial and/or lacustrine sediments, was not a single connected quaternary deposits in archaeo-geosites completes the engineering of the construction. the building of magnificent graves also reflects the advanced economic and cultural level reached by the etruscan population from the 2nd century bc. beginning with the belief that life continued beyond death, graves were built to ensure durability and future expansion. like many other ancient peoples, the etruscans built their graves underground and, in order to reproduce the idea of a life after the death, tombs were grouped in necropolises, which are “cities of dead people”. generally, the necropolises were placed outside the city walls according to the topographic setting. the palazzone necropolis is located at the bottom of the hill, in the south-eastern part of the boundary between the pleistocene deposits and the alluvial sedi 210 a fig. 2 a) the etruscan arch, made of travertine blocks, is one of the gates along the etruscan wall. b) the etruscan well, entirely dug inside pleistocene gravel. fig. 3 the volumni hypogeum, the most famous tomb in the palazzone necropolis. the interior was entirely dug inside gravel and sand belonging to the volumni unit (see text for details). bizzarri r et al. 211 fig. 4 a) detailed geological map of the palazzone necropolis, with the location of tombs (numbers). tracing of cross sections (see fig. 7) is also shown. b) stratigraphic scheme for the study area. c) old quarry front (no longer visible), showing the stratigraphic boundary between the volumni and palazzone units. quaternary deposits in archaeo-geosites ments of the tiber river. it extends over an area of almost 19,000 m2, representing one of the most important etruscan burial sites in central italy. the tomb (fig. 3), named after the "volumni hypogeum" (from the name of the etruscan family velimna lat. volumni), was discovered in a completely accidental way, during the construction of some roads on february 5, 1840. it is currently the most important of the entire necropolis (lower left in fig. 4a). the palazzone necropolis includes about two hundred graves, most of which can be visited (marked by numbers in fig. 4a). the age of the tombs is mostly hellenistic and only five date to the archaic period (second half of the 6th century bc beginning of the 5th century bc). although not very numerous, these graves are essential for confirming the etruscan presence in perugia since the 6th century bc. in most cases, the tombs have a single chamber, but others have a more complex plan, such as the volumni hypogeum, where, in addition to a central corridor, the excavation is divided into side cells and a tablinium, on the farthest side from the entrance. in the centre, in the vestibule, some benches built of sediments house the urns. the ceiling, in the shape of a sloping roof, and figures connected to the world of the dead are reproduced in the gables on the highest part of the excavation. the urns, mostly in travertine, and the items found in the hellenistic tombs are kept in the vestibule of the entrance of the volumni hypogeum (fig. 3). 3. sedimentological characterization of the palazzone necropolis the archaeological area of the palazzone necropolis is also to be considered as a key-point in reconstructing the plio-pleistocene geological evolution of the perugia hill. nonetheless, the presence of graves in the surroundings, known by the superintendence since the 1960s, suggests a greater extension of the area. the two hundred documented tombs, many of which are no longer visible or accessible today, were all excavated in the natural sediments (figs. 4a, 5, 6). both within and outside the tourist route, the tombs were excavated on at least five main superimposed levels, between ~210 m (floor of the volumni hypogeum) and ~238 m above sea level (tombs 12, 16). the area of the necropolis is covered with gravel and cemented gravel, mainly in the lower portion, while sand is well represented in the upper portion of the hill and dominates on the western side. both lithotypes are quite solid, so as to support the vertical walls and vaulted ceilings, and are associated with levels and lenses of finer deposits. as will be discussed later, all deposits inside the tombs are of fluvial origin. the deposits maintain some stable sedimentary features throughout the whole stratigraphic succession, even though there are variations in grain size from level to level. pebble to cobble gravel beds have a grainsupported texture, with the abundant presence of a coarse sand matrix, sometimes at the edge of the granules, and a moderate degree of selection (σ = 1.00 φ sensu folk & ward, 1957). clasts are mainly rounded/ sub-rounded to sub-angular (rounding 0.6-0.8: powers, 1953; pettijohn, 1957), mainly blade and rod-shaped, subordinately equi-dimensional, in accordance with zingg (1935). gravels are mostly formed by grey to brown calcarenites and medium to coarse-grained arenites, all presumably derived from lithostratigraphic units of the tuscan succession; quartz and/or calcite monomineralogic gravels, light brown micrites and occasionally green volcanites (fragments of ophiolites) were also documented. gravel usually has a dark brown or reddish oxidized surface. sands are mainly light yellow in colour, moderately to well sorted (1.00 <σ <0.5 φ sensu folk & ward, 1957), made of angular to subangular grains of variable sphericity: mainly quartz grains, with high sphericity, and lithic fragments of more irregular shape. finer deposits, occurring either, as very discontinuous and thin layers, lenses or chips, are light grey silty clay to clay (fig. 7). as will be discussed later, this overall uniformity seems to indicate that the supply came from a rather similar feeding area through time, or several sedimentation phases of similar material. nonetheless, throughout the area the presence of two overlapping lithostratigraphic units is documented and distinguished on the basis of sedimentological and lithostratigraphic features. the two units were preliminarily identified and partly described in melelli et al. (2016), where they were indicated as units a and b. here, the two units are named, in stratigraphic succession, volumni (vol) unit and palazzone (plz) unit (fig. 4a, b). in this paper the palazzone unit is extensively described for the first time. the contact can be observed directly only within the tombs in the intermediate levels (tombs 6, 7, 25, and 17), over the stairs leading to the volumni hypogeum. it is also quite clear through the old quarry front (fig. 4c). a third unit is indicated as fornace ferrini clay. it crops out fairly close but is not documented inside the boundaries of the necropolis (see the stratigraphic scheme in fig. 4b). 3.1. depositional architecture codes used in facies description and depositional architecture were derived from miall (1991, with references therein) and einsele (1992). channels (ch), gravel bars and bedforms (gb) and sandy bedforms (sb) are the only macroand mesoforms recognizable throughout the necropolis area, while overbank fines (of) crop out just outside. gravel and sand with parallel (gp, sp) and trough (gt, st) cross-stratification are commonly described facies, accompanied by massive gravel (gm), plain parallel-laminated sand (sh), ripplelaminated sand (sr), and plain parallel-laminated silt and clay (fl). 3.1.1. volumni unit (vol) it crops out inside the hypogeum and all the lowermost tombs (2, 3a, 3b, 4, 5, 31, 32, 32b), as well as in the lower part of tombs 6, 7, 17 and 25, and the quarry front (fig. 5). clearly identifiable channels characterize the unit, with longitudinal continuity and a wideness not able to be evaluated, due to outcropping conditions. the channel fill (fig. 5) is organized in gravel bedforms (gb) in the lower part and upstream, passing upward and 212 bizzarri r et al. entrance stairs to the volumni hypogeum and in the lower part of tombs 33 and 35-36, while the upper part of the latter and all the other outcropping situations of the palazzone unit can be traced back to interval plz2. 3.1.3. fornace ferrini clay finer deposits crop out widely just westward of the study area, although recent alluvial sediments and/or colluvium often cover them. this unit is made of crudely to thin-bedded clay and/or silty clay, and was previously reported as “argille ad helix” unit (de angelis d’ossat, 1918) or “fornace ferrini lithofacies” (regione umbria, 2010). this unit consists of overbank and alluvial plain sediments, lateral to deposits visible inside the necropodownstream into sandy bedforms (sb). in both cases, longitudinal to transversal migrant bars, with downstream gp and sp cross stratifications, prevail. whereas facies gm, gt, st, and sh are less frequent and only locally visible (for instance, see fig. 4 in melelli et al., 2016), particularly within the hypogeum, as well as lenticular horizons of clay/silt with fl facies. the progradation of bars, the axes of channels and secondary flows, evaluated by measuring imbrications, identify transport directions dispersed between sse and ssw. three overlapping intervals are identified (depositional sequences), here indicated as vol1, vol2 and vol3 respectively. the lower portion (but not the base) of the vol1 interval is only visible within the volumni hypogeum (ch 1 ch 4), and was previously described by melelli et al. (2016), while the other two intervals are only described throughout the palazzone necropolis. the first two intervals (vol1, vol2) clearly show a fining-upward trend, whereas the third one is cut in its coarse portion by the deposits of the overlying unit. 3.1.2. palazzone unit (plz) it crops out inside tombs from 8 to 16, from 18 to 24, from 26 to 30b and from 33 to 36, in the upper part of tombs 6, 7, 17 and 25, and above the access stairway to the volumni hypogeum. it is finally visible at the top of the quarry front (fig. 4c). unlike the volumni unit, the depositional architecture appears more complex (fig. 6), with channels showing a complex fill (multi-storey channels), first gravely/sandy (alternating gb and sb), then sandy (prevailing sb), with cross stratification gt, st and sp that overlap and intersect laterally, often with little continuity. gravel and sands alternate with silt to clay horizons and lenses (facies fl), often partially or totally reworked within channels and/or bars (clay chips). the continuity and/or lateral heteropy of facies is not easy to follow through the tombs. however, it is possible to recognize the progradation of structures in the current direction dispersed between nw and s (downstream accretion), according to a main transport axis (the axis of the channels) towards sw. variation of the lateral facies is very marked transversely with respect to this axis (approximately towards nw-se). similar to what was observed for the underlying unit, two overlapping intervals (depositional sequences), indicated as plz1 and plz2, can be identified (fig. 4b). the boundary is marked by a very extensive erosional surface both in the main transport direction and transversally to the same, which indifferently cuts both silty, and clay overbank deposits and channels/bars of the interval below. the plz1 interval is partially visible above the 213 fig. 5 lithofacies and sedimentary structures documented inside the volumni unit. l1-l5=levels measured inside each single tomb, ch=channel (v1-v5 refer to their progressive number inside the volumni unit), gb=gravel bars and bedforms, sb=sandy bedforms, gp=parallel cross-stratified gravel, sp=parallel cross-stratified sand, sh=plain parallel-laminated sand, fl=plain parallel-laminated silt and clay. grain size scale: s = sand, g = granules, p = pebbles, c = cobbles. quaternary deposits in archaeo-geosites 214 fig. 6 lithofacies and sedimentary structures documented inside the palazzone unit. l1-l10=levels measured inside each single tomb, ch=channel (p2-p13 refer to their progressive number inside the palazzone unit), gb=gravel bars and bedforms, sb=sandy bedforms, gt=trough cross-stratified gravel, st=trough cross-stratified sand sp=parallel cross-stratified sand, sh=plain parallel-laminated sand, sr=ripple-laminated sand, fl=plain parallel-laminated silt and clay. grain size scale: s = sand, g = granules, p = pebbles, c = cobbles. bizzarri r et al. lis (fig. 4a, b). 3.1.4. vertical and lateral organization the measured dip directions are fairly constant, with minimal dispersion between sse and ssw (fig. 4b, c), and the two units show a minimal difference in slope, with plz slightly (2° to 4°) more inclined than vol. the surface separating the two units is a disconformity or a gentle angular unconformity surface (figs. 4b, 7). both units disappear southwestward, below recent alluvial deposits. a lateral and vertical transition between the palazzone unit and the fornace ferrini clay appears reliable to the west of the area investigated (fig. 4b). presently, it is not clear whether the fornace ferrini clay is also heteropic to the volumni unit. 4. palaeoenvironmental reconstruction of the palazzone necropolis: insights for the perugia hill all the deposits analysed, based on the sedimentary facies described, can be easily referred to transport and sedimentation produced by traction currents, prevailing channelled, and/or by settlements of fines, and finally they are all associated with fluvial depositional context. as discussed by melelli et al. (2016) for the volumni hypogeum, fluid flow processes dominate also throughout deposits observed in the palazzone necropolis, whereas deposits from gravitational processes or from sediment gravity flows sensu lowe (1979) and nemec & steel (1984) are totally absent. the lack of forms due to lateral accretion (la sensu miall, 1991, with references therein), the geometries of gravel and sandy bodies, and the dispersion of the palaeocurrents lead us to associate the deposits of both units with braided fluvial systems. however, the depositional architecture assumes different settings for the two units, clearly indicating the overlap of two distinct patterns. deposits of the volumni unit indicating the undercurrents are easily interpretable through classical depositional models for downstream migration of gravely, sandy, or mixed bars (bluck, 1976; hein & walker, 1977; steel & thompson, 1983; rust, 1984; southard et al., 1984, among others). the depositional architecture of the deposits of the palazzone unit is more complex. the marked lateral variability of facies can be referred to the lateral variation of the flows, induced by the presence of previously deposited bars, or as a progressive construction of structures during different phases of flooding and power failure. both cases refer to the models proposed by bridge (1993). the lower portion of intervals vol1 and vol2, as well as the visible part of vol3, can be associated with shallow, gravely braided channels, similar to the scott type model, according to the classic river models proposed by miall (1991, with references therein), as al 215 fig. 7 n-s (a-a’) and sw-ne (b-b’) profiles (see fig. 4) through the palazzone necropolis, showing the vertical and lateral depositional architecture for volumni and palazzone units. quaternary deposits in archaeo-geosites network (braid-plain). both significant tectonic activity and the setting of drainage in the meridian sense of the main valley (palaeo-tiber) are possible in this phase. 216 fig. 8 palaeoenvironmental and palaeoecological restoration for study deposits, in accordance with the models of miall (1991, and references therein). da=downstream accretion macroforms, gb=gravel bars and bedforms, sb=sandy bedforms, ff=floodplain deposits. ready proposed by melelli et al. (2016) (fig. 8). both vol1 and vol2 intervals seem to evolve upwards to sandy braided fluvial systems, always of shallow depth, somehow according to the features of the platte type (fig. 8). on the other hand, the deposits of the palazzone unit still identify a braided river system, with deeper major channels and the diffused occurrence of secondary channels and subordinated structures, somehow comparable with the donjek type model (fig. 8). in any case, it should be noted that such parallelism could be exclusively descriptive, as these models are inspired by real cases in specific morphoclimatic contexts and not comparable with what characterized our latitudes during the pleistocene. in this way, each river is a model in itself, often only partially comparable with those reported in the literature. the facies described and their vertical and lateral association, both for the volumni and the palazzone units, are probably associated with channel networks developed in the external portions of wide alluvial fans. the hypothesis of channels at the topset of a fan delta apparatus (cattuto & gregori, 1988) cannot yet be totally excluded in the case of the volumni unit. however, this interpretation seems less solid, in the light of an overlying river system (identified by the palazzone unit), lateral to an alluvial plain or in any case to a subaerial overbank. according to melelli et al. (2016), the presence of proximal alluvial facies already at low altitude on the present-day valley, added to those described in the past at the top of the perugia hill (rosatini, 2012; manassei, 2014), seems to refer to several overlapping apparatuses and to a fairly complex geological evolution. the data collected in this work allow a first fluvial system (volumni unit) to be identified, clearly in a regressive phase, and a second system (palazzone unit), which, instead, advances towards the valley, at least in a first stage. the two overlapping river systems also have prevailing transport axes oriented in slightly different directions. for both, the area of the necropolis highlights the pattern of the channels rather than the alluvial plain. the unconformity dividing the two overlapping fluvial systems could indicate both significantly different ages, and/or an important change in the river regime, as the consequence of important climatic changes or tectonics. the first system can be thought of as an apparatus built at the mouth of a secondary one in the main valley, in a time span of progressive reduction of the energy of the relief due to tectonic stability or rising of the local base level. such base level, given the lack of definitive geological evidence, could be identified as both an alluvial plain or a lake. the increased energy marked by the downstream progradation of the second system is probably accompanied by a wider and weakly inclined foothills towards the main fluvial plain, drained by a braided river bizzarri r et al. the age for the two systems, as well as reasons for their superpositioning, is currently an open problem. the chronological attribution of the volumni unit is unclear, due to the lack of stratigraphic data. on the other hand, the fossil record reported from neighbouring sites (fornace ferrini, villa spinola, piscille, and san costanzo) allow the palazzone unit and its fluvial environment to be attributed to the early pleistocene (probably tasso f.u.: argenti & sardella, 2003; argenti, 2004). this attribution would place the unit in lateral heteropy southwards with the santa maria di ciciliano unit (ambrosetti et al., 1995; basilici, 2000), westwards with the san biagio subsinthem (regione umbria, 2010; argenti et al., 2013), and northand eastwards with the fighille sinthem or equivalent units (cattuto et al., 1995; pialli et al., 2009; melelli et al., 2010; plesi et al., 2010). regarding the volumni unit and its palaeoenvironment, this river system could represent both an evolutionary phase immediately preceding and in continuity with the one marked by the palazzone unit, or it could be totally disconnected and belong to an even much earlier phase. the data collected up to now and the arguments presented above seem to favour the first hypothesis; however, only by including the two units in the more general and complex framework of the evolution of the perugia hill will a correct and exhaustive evaluation be able to be made. 5. conclusions the land of urban areas is covered with buildings and infrastructures. for this reason and because of frequent transformations of the topographic surface to facilitate human settlement, it is rare to see the natural disposal of the geological succession. this being so, in most cases, the only possibility of determining the type and arrangement of the sediments is by investigating underground urban cavities. in historical cities, some cavities witness to the presence of ancient peoples and contain precious archaeological remains. combining these two aspects, the geological features and the archaeological ones, some of these places may be defined as archaeo-geosites and could be an excellent attraction for high-level tourism. the palazzone necropolis, one of the most famous etruscan necropolises in central italy, was investigated in order to define the area as an archaeo-geosite. the necropolis is a good starting point in the restoration of the geological and palaeoenvironmental evolution of the perugia hill. the sedimentological features and the palaeodepositional restoration, indeed, lead to the reconsideration of the validity of some geological units proposed through time, as well as the scenario of a thick -layered, structured and long-lasting delta/fan delta apparatus. as clearly shown in the palazzone necropolis deposits, such evolution was rather articulated. nonetheless, the necropolis, as well as the other archaeogeosites in the urban area of perugia, provides the opportunity to propose a geo-touristic route, expanding the multifaceted offer of perugia. in the perugia hill, where a fluvial (and alluvial) sedimentary sequence outcrops, urbanization and a very active fluvial and gravitational morphogenesis cover a large part of the natural sediments with buildings, infrastructures or colluvial and debris deposits. for this reason, the underground cavities such as the palazzone necropolis can play a key role in the palaeoenvironmental reconstruction of the area. in particular, the sediments where the graves were dug may be explained as two first fluvial systems. the lower, named volumni unit, is in a regressive phase, while the second one (palazzone unit) is advancing towards the tiber river valley. an unconformity divides the two overlapping fluvial systems, indicating significantly different ages and/or an important change in the river regime. both hypotheses suggest relevant climatic changes or tectonics. thus, the study site plays a key role in reconstructing the quaternary evolution of the perugia hill and, in a broader sense, the tiberino basin. acknowledgements this study was supported by the silene project (principal investigator corrado cencetti) co-funded by the fondazione cassa risparmio perugia together with the university of perugia and by the perusiae project (principal investigator laura melelli), funded by the department of physics and geology of the university of perugia. the authors wish to thank prof. a. bertini, prof. m.g. forno, and two other anonymous reviewers, for their precious suggestions in improving the manuscript. references ambrosetti p., basilici g., capasso-barbato l., carboni m.g., di stefano g., esu d., gliozzi e., petronio c., sardella r., squazzini e. (1995) il pleistocepleistocene inferiore nel ramo sud-occidentale del bacino tiberino (umbria): aspetti litostratigrafici e biostratigrafici. il quaternario, 8, 19-36. argenti p. (2004) plio-quaternary mammal fossiliferous sites of umbria (central italy). geologica romana, 37, 67-78. argenti p., bizzarri r., pazzaglia f. (2013) iv.5 successioni dei bacini sedimentari plio-pleistocenici. in: barchi m., marroni m. (eds.) note illustrative della carta geologica d’italia alla scala 1:50.000 foglio 310 "passignano sul trasimeno". ispra, regione umbria, 74-99. argenti p., sardella r. (2003) early pleistocene large mammals from villa spinola (perugia, central italy). bollettino della società paleontologica italiana, 42(3), 315-321. basilici g. (2000) floodplain lake deposits on an early pleistocene alluvial plain (tiberino basin, central italy). in: gierlowski kordesch e.h., kelts k.r. (eds.) lake basins through space and time. aapg studies in geology, 46, 535-542. bathrellos g.d., skilodimou h.d., chousianitis k., youssef a.m., pradhan b. (2017) suitability estimation for urban development using multi-hazard assessment map. science of the total environment, 575, 119-134. bluck b.j. (1976) sedimentation in some scottish rivers of low sinuosity. transactions of the royal society of edinburgh, 69, 425-456. borghi a., d’atri a., martire l., castelli d., costa e., 217 quaternary deposits in archaeo-geosites dino g., favero longo s.e., ferrando s., gallo l.m., giardino m., groppo c., piervittori r., rolfo f., rossetti p., vaggelli g. (2014) fragments of the western alpine chain as historic ornamental stones in turin (italy): enhancement of urban geological heritage through geotourism. geoheritage, 6(1), 41-55. bridge j.s. (1993) the interaction between channel geometry, water flow, sediment transport and deposition in braided rivers. in: best j.l, bristow c.s. (eds.) braided rivers. special publication of the geological societyof london, 75, 16-71. carreño m.l., cardona o.d., barbat a.h. (2007) urban seismic risk evaluation: a holistic approach. natural hazards, 40(1), 137-172. cattuto c., cencetti c., fisauli m., gregori l. (1995) i bacini pleistocenici di anghiari sansepolcro nell'alta valle del f. tevere. il quaternario, 8, 1, 119-128. cattuto c., gregori l. (1988) il colle di perugia: note di geologia, idrogeologia e geomorfologia. bollettino della società geologica italiana, 107, 131-140. chester d.k., degg m., duncan a.m., guest j.e. (2000) the increasing exposure of cities to the effects of volcanic eruptions: a global survey. global environmental change part b: environmental hazards, 2(3), 89-103. christenson e., elliott m., banerjee o., hamrick l., bartram j. (2014) climate-related hazards: a method for global assessment of urban and rural population exposure to cyclones, droughts, and floods. international journal of environmental research and public health, 11(2), 2169-2192. de angelis d'ossat g. (1918) rinvenimento di mammiferi fossili nel pliocene lacustre e salmastro umbro. bollettino della società geologica italiana, 37, 39-45. de wever p., baudin f., pereira d., cornée a., egoroff g., page k. (2017) the importance of geosites and heritage stones in cities a review. geoheritage, 9(4), 561-575. einsele g. (1992) sedimentary basins. evolution, facies, and sediment budget. springer-verlag, berlino, pp. 628. folk r.l., ward w. (1957) brazos river bar: a study in the significance of grain size parameters. journal of sedimentary petrology, 27, 3-26. güneralp b., güneralp i̇., liu y. (2015) changing global patterns of urban exposure to flood and drought hazards. global environmental change, 31, 217-225. haynes s. (2000) etruscan civilization. british museum press, london. hein f.j., walker r.g. (1977) bar evolution and development of stratification in the gravelly, braided, kicking horse river, british columbia. canadian journal of earth sciences, 14, 562-570. lowe d.r. (1979) sediment gravity flows: their classification and some problems of application to natural flows and deposits. in: doyle l.j., pilkey d.h. (eds.), sepm special publication, 27, 75-82. manassei d. (2014) siti archeologici nella geologia del colle di perugia. in: melelli l., pauselli c., cencetti c. (eds.), atti del convegno nazionale “dialogo intorno al paesaggio”. (perugia, 19-22 febbraio 2013). culture territori linguaggi, 4(2), 246-257. melelli l., barchi m., brozzetti f., lupattelli a., mirabella f., pazzaglia f., pucci s., saccucci l. (2010) morphotectonic evolution of high tiber valley (umbria, italy) related to an active low angle normal fault segmentation. rendiconti online della società geologica italiana, 11, 629-630. melelli l., bizzarri r., baldanza a., gregori l. (2016) the etruscan “volumni hypogeum” archeogeosite: new sedimentological and geomorphological insights on the tombal complex. geoheritage, 8 (4), 301-314. miall a.d. (1991) hierarchies of architectural units in clastic rocks, and their relationship to sedimentation rate. in miall a.d., tyler n. (eds.), the threedimensional architecture of terrigenous clastic sediments, and its implications for hydrocarbon discovery and recovery. sepm concepts in sedimentology and paleontology, 3, 6-12. nati d., nardelli s. (2010) le necropoli di perugia. città di castello, edimond ed. nemec w., steel r.j. (1984) alluvial and coastal conglomerates: their significant features and some comments on gravelly mass flow deposit. in: koster e.h., steel r.j. (eds.), sedimentology of gravels and conglomerates. cspg memoir, 10, 131. orsi g., di vito m.a., isaia r. (2004) volcanic hazard assessment at the restless campi flegrei caldera. bulletin of volcanology, 66(6), 514-530. pettijohn f.j. (1957) sedimentary rocks harper, row, pp. 718. pialli g., plesi g., damiani a.v., brozzetti f., boscherini a., bucefalo palliani r., cardinali m., checcucci r., daniele g., galli m., luchetti l., motti a., nocchi m., ponziani f., rettori r. (2009) note illustrative del foglio 289 "città di castello" della carta geologica d'italia alla scala 1:50000. servizio geologico d'italia, pp. 142. pica a., vergari f., fredi p., del monte m. (2016) the aeterna urbs geomorphological heritage (rome, italy). geoheritage, 8(1), 31-42. plesi g., arcaleni a., bartoccini p., boscherini a., botti f., checcucci r., damiani a.v., daniele g., del gaia f., felicioni g., galli m., luchetti l., motti a., palandri f., ponziani f., preziosi e., rettori r., sabatini s., simone g., tosti s., tuscano f., uffreduzzi t., merangola s. (2010) note illustrative del foglio 299 "umbertide" della carta geologica d'italia alla scala 1:50000. servizio geologico d'italia, pp. 144. powers m.c. (1953) a new roundness scale for sedimentary particles. journal of sedimentary petrology, 23, 117-119. pucci s., mirabella f., pazzaglia f., barchi m.r., melelli l., tuccimei p., saccucci l. (2014) interaction between regional and local tectonic forcing along a complex quaternary extensional basin: upper tiber valley, northern apennines, italy. quaternary science reviews, 102, 111-132. regione umbria (2010) progetto di microzonazione 218 bizzarri r et al. sismica delle aree urbane 1° intervento: città di perugia. regione umbria, perugia, 40 pp. reynard e., brilha j. (eds.). (2017) geoheritage: assessment, protection, and management. elsevier. reynard e., coratza p., giusti c. (2011) geomorphosites and geotourism. geoheritage, 3(3),129-130. rosatini m. (2012) il colle di perugia: i conglomerati nei sotterranei del duomo. tesi di laurea, università di perugia. rust b.r. (1984) proximal braidplain deposits in the middle devonian malbaie formation of eastern gaspé, quebec, canada. sedimentology, 31(5), 675-695. southard j.b., smith n.d., kuhnle r.a. (1984) chutes and lobes: newly identified elements of braiding in shallow gravelly streams. in: koster e.h., steel r.j. (eds.), sedimentology of gravels and conglomerates. cspg memoir, 10, 51-59. steel r.j., thompson d.b. (1983) structures and textures in triassic braided stream conglomerates (‘bunter’ pebble beds) in the sherwood sandstone group, north staffordshire, england. sedimentology, 30(3), 341-367. zingg t. (1935) beitrag zur schotter analysis. schweizerische mineralogische und petrographische mitteilungen, 15, 39-140. . ms. received: april 13, 2018 final text received: november 11, 2018 219 quaternary deposits in archaeo-geosites 220 base traduzione italiana della terminologia presente in “guidelines for analysis and description of soil and regolith thin sections” (stoops, 2003) cristiano nicosia1, luca trombino1,2, georges stoops3 1dipartimento di scienze della terra, “a. desio”, università di milano. 2cnr idpa, milano. 3lab.mineralogy and petrology, dep. geology and soil science, ghent university, belgium. corresponding author: c. nicosia <cristiano.nicosia@unimi.it> riassunto: nicosia c. et al., traduzione italiana della terminologia presente in “guidelines for analysis and description of soil and regolith thin sections” (stoops, 2003). (it issn 0394-3356, 2010). diverse terminologie di riferimento sono state adottate negli anni per le descrizioni delle sezioni sottili nell’ambito della micromorfologia del suolo. di queste terminologie, tutte originariamente in lingua inglese, esistono traduzioni italiane più o meno complete, la cui tradizione è riportata nell’introduzione del presente contributo. mancava, tuttavia, all’interno del panorama italiano delle scienze della terra, una traduzione della più recente terminologia di riferimento, quella cioè proposta dal manuale “guidelines for analysis and description of soil and regolith thin sections” (stoops, 2003). si è dunque proceduto a redarre questa traduzione, mirando a limitare al massimo il numero di termini di nuova introduzione, quelli cioè non già presenti in precedenti traduzioni italiane od almeno nella letteratura di scienze della terra. si è inoltre voluto proporre un solo termine italiano per ciascun corrispettivo originale inglese, armonizzando inoltre quando possibile il termine italiano con quelli impiegati nelle traduzioni nelle altre lingue del gruppo neo-latino. abstract :nicosia c. et al., italian translation of the terminology contained in "guidelines for analysis and description of soil and regolith thin sections" (stoops, 2003). (it issn 0394-3356, 2010). various terminologies have been employed through the decades for description in soil micromorphology and micropedology. different italian translations of such terminologies, more or less complete, have been published. their succession is described in the introduction of the present article. nevertheless, an italian translation of the most recent terminology, the one contained in the manual “guidelines for analysis and description of soil and regolith thin sections” (stoops, 2003) was missing. such a translation has therefore been edited, aiming at limiting the introduction of new terms (e.g. terms that were not present in older italian translations or at least within the earth science literature). moreover, one single term has been proposed for its original english counterpart, trying to harmonise each term with the other translations belonging to the neo-latin language group. parole chiave: micromorfologia del suolo, terminologia, descrizione di sezioni sottili. keywords: soil micromorphology, terminology, thin section description. il quaternario italian journal of quaternary sciences 23(1), 2010 15-20 1. introduzione la micromorfologia del suolo è definibile come “un metodo per studiare campioni di suolo e di regolite con tecniche microscopiche ed ultramicroscopiche al fine di identificarne le diverse componenti e definire le loro mutue relazioni nello spazio e nel tempo” (stoops, 2003). con il presente articolo si intende offrire la sistematica traduzione in italiano dei termini per la descrizione micromorfologica presentati all’interno del manuale “guidelines for analysis and description of soil and regolith thin sections” di stoops (2003), nell’ambito di un progetto promosso dallo stesso autore per la traduzione in più lingue del manuale in questione (si veda ad es. stoops, a cura di 1986). la prima terminologia di riferimento per la micromorfologia fu proposta dal tedesco kubiena (1938) con l’opera “micropedology”. quest’ultima era caratterizzata da un approccio di tipo morfo-analitico (stoops & eswaran, 1986; stoops, 1993), che prevedeva un’analisi della fabric (organizzazione interna del suolo) utilizzando un criterio puramente morfologico, dal quale discendeva poi l’interpretazione in chiave genetica della morfologia osservata. in opere successive, kubiena (1948; 1953; 1970) introdusse invece un approccio morfo-genetico, nel quale a ciascun tipo di fabric veniva assegnato un nome, il quale rifletteva la posizione del materiale all’interno di un sistema genetico-evolutivo predefinito dallo stesso kubiena (stoops & eswaran, 1986; stoops, 1993). parzialmente ispirato all’approccio morfo-analitico di kubiena, fu pubblicato da r. brewer nel 1964 “fabric and mineral analysis of soils”, rivisto ed aggiornato poi nella seconda edizione (brewer 1976). si tratta del primo tentativo di definire un sistema organico per la descrizione micromorfologica di dettaglio dei suoli. l’opera introdusse alcuni concetti fondamentali quali quello di s-matrix (massa di fondo) e di pedological feature (figura pedologica), e propose inoltre una classificazione dei pori in base alla loro forma e modo di formazione. un terzo importante manuale di riferimento, ”handbook for soil thin section description” di bul16 c. nicosia, l. trombino & g. stoops lock et al. (1985) nacque dal lungo lavoro dell’international working group on soil micromorphology, costituitosi durante il terzo international meeting on soil micromorphology, tenutosi a wroclaw, polonia, nel 1969 (bullock et al., 1985; stoops, 2003). tale manuale si propose di utilizzare un approccio prettamente morfologico e non genetico, essendo esso mirato alla sola descrizione, e non all’interpretazione, delle sezioni sottili. una traduzione italiana pressoché completa dei termini dell’ “handbook” di bullock et al. (1985) è stata pubblicata da cremaschi & rodolfi (1990) e ripresa in parte da malucelli & gardi (1999). successivamente anche in cremaschi (2000) sono stati tradotti in italiano molti dei termini del testo in questione. tra le altre terminolgie di riferimento ricordiamo quelle incluse in “micromorphology of soils” (fitzpatrick 1984) e “soil microscopy and micromorphology” (fitzpatrick 1993). parte dei termini contenuti in quest’ultimo lavoro sono stati tradotti in italiano in malucelli & gardi (1999). il manuale di stoops (2003) è parzialmente basato sull’ “handbook for soil thin section description” di bullock et al. (1985) e costituisce la terminologia di riferimento di più recente pubblicazione nell’ambito della micromorfologia del suolo. 2. linee guida della traduzione e delle definizioni dei termini nella stesura della traduzione sono stati seguiti alcuni semplici criteri per la scelta degli equivalenti italiani dei termini inglesi. innanzitutto, sono stati favoriti i termini in italiano presenti in letteratura da maggiore tempo, e dunque quei termini che, confluiti nella terminologia di stoops (2003) direttamente da di bullock et al. (1985) erano stati tradotti a partire da cremaschi & rodolfi (1990). questo criterio è stato seguito nella speranza di minimizzare la quantità di termini nuovi che vengono introdotti col presente lavoro. per la stessa finalità, qualora ci si trovasse a dover tradurre termini “prestati” alla micromorfologia a partire da altre discipline, si è sempre tentato di impiegare l’equivalente italiano più largamente diffuso nella letteratura di riferimento per quelle stesse discipline. si è inoltre sempre stabilita un’unica traduzione italiana per ciascun termine inglese, al fine di evitare confusioni e sovrapposizioni, linea guida già formulata a partire da stoops (a cura di, 1986). un altro criterio è stato quello di scegliere termini che, quando possibile, fossero simili a quelli adottati nelle altre traduzioni all’interno del medesimo ceppo linguistico, nel nostro caso quello delle lingue neo-latine. una nota specifica merita il termine fabric, visto l’ampio utilizzo che ne viene fatto sia in micromorfologia che in altre discipline delle scienze della terra. il termine fabric è stato tradotto come “organizzazione spaziale”: esso può essere utilizzato nell’accezione di soil fabric (organizzazione spaziale del suolo) oppure in quella che fa riferimento all’organizzazione spaziale dei diversi cristalli che compongono un minerale (v. § 3.9). per ragioni di brevità e praticità è invece stato mantenuto in inglese il termine b-fabric anche nella forma non abbreviata di fabric di birifrangenza. 3. traduzione di fianco a ciascun termine inglese, tra parentesi, è indicata la pagina alla quale il termine compare nel testo di stoops (2003). l’ordine di presentazione ricalca l’ordine dell’opera originale. 3.1 concepts (concetti) arrangement (38): disposizione (spaziale) soil fabric (34): organizzazione spaziale del suolo fabric element (37): elemento dell’organizzazione spaziale integrated fabric (34): organizzazione spaziale integrata observed fabric (34): organizzazione spaziale osservata fabric unit (36): unità dell’organizzazione spaziale partial fabric (36): organizzazione spaziale parziale pattern (37) : modello 3.2 orientation and distribution patterns (modelli di orientazione e distribuzione) distribution: distribuzione orientation: orientazione basic (distribution, orientation) (38): distribuzione/orientazione fondamentale random (distribution, orientation) (38): distribuzione/ orientazione casuale clustered distribution (38): distribuzione/orientazione a gruppi linear distribution (38): distribuzione/orientazione lineare banded distribution (39): distribuzione/orientazione a bande fan-like distribution (39): distribuzione/orientazione a ventaglio interlaced distribution (39): distribuzione/orientazione intrecciata striated orientation (40): distribuzione/orientazione striata referred (distribution, orientation) (40): distribuzione/ orientazione riferita unreferred (distribution, orientation) (40): distribuzione/ orientazione non riferita perpendicular orientation (40): orientazione perpendicolare parallel orientation (40): orientazione parallela inclined orientation (40): orientazione inclinata radial (41): radiale bow-like (distribution, orientation) (41): distribuzione/ orientazione ad arco crescent (distribution, orientation) (41): distribuzione/ orientazione con andamento a mezzaluna related (distribution, orientation) (41): distribuzione/ orientazione relativa unrelated (distribution, orientation) (41): distribuzione/ orientazione non relativa galaxy fabric (45): fabric a galassia turbate fabric (45): fabric a tùrbine 3.3 c/f related distribution (distribuzione relativa g/f o grossolana/fine) c/f related distribution (42): distribuzione relativa g/f c/f limit: limite g/f c/f-ratio: rapporto g/f chitonic (42): chitonica enaulic (42): enaulica gefuric (42): gefurica monic (42): monica porphyric (43): porfirica close (c/f related distribution) (42): (distribuzione relativa g/f) chiusa single spaced (c/f related distribution) (42): (distribuzione relativa g/f) a spaziatura singola double spaced (c/f related distribution) (42): (distribuzione relativa g/f) a spaziatura doppia open (c/f related distribution) (42): (distribuzione relativa g/f) aperta 3.4 microstructure (microstruttura) 3.4.1 general (concetti generali) microstructure (57): microstruttura separation (degree of) (60): (grado di) separazione separated (60): separata accommodation (degree of) (62): (grado di) accomodamento accommodated (63): accomodata 3.4.2 voids (vuoti) void (63): vuoto poroid (64): poroide packing void (64): vuoto intergranulare complex (packing voids) (64): vuoti intergranulari complessi compound (packing voids) (64): vuoti intergranulari composti simple (packing void) (64): vuoto intergranulare semplice vesicle (64): vescicola channel (65): canale chamber (65): camera vugh (65): vacuo plane (65): vuoto planare moldic voids (65): vuoti da impronte 3.4.3 aggregates (aggregati) crumb (58): grumo granule (58): granulo ped (58): aggregato plate (59): lamina prism (59): prisma 3.4.4 microstructures (microstrutture) angular blocky (microstructure) (68): (microstruttura) poliedrica angolare subangular blocky (microstructure) (68): (microstruttura) poliedrica subangolare bridged grain (microstructure) (69): (microstruttura) a ponte channel (microstructure) (68): (microstruttura) a canali chamber (microstructure) (68): (microstruttura) a camere crumb (microstructure) (68): (microstruttura) grumosa granular (microstructure) (68): (microstruttura) granulare intergrain microaggregate (microstructure) (69): (microstruttura) a microaggregati intergranulari lenticular (microstructure) (68): (microstruttura) lenticolare massive (microstructure) (68): (microstruttura) massiva pellicular grain (microstructure) (69): (microstruttura) pellicolare platy (microstructure) (68): (microstruttura) laminare single grain (microstructure) (69): (microstruttura) a grani singoli 17traduzione italiana della terminologia presente in ... spheroidal (microstructure) (68): (microstruttura) sferoidale spongy (microstructure) (68): (microstruttura) spugnosa vermicular (microstructure) (68): (microstruttura) vermicolare vesicular (microstructure) (68): (microstruttura) vescicolare vughy (microstructure) (68): (microstruttura) a vacui 3.5 fine material (materiale fine) micromass (93): micromassa limpidity (86): limpidezza limpid (86): limpido speckled (86): maculato dotted (86): puntinato cloudy (86): nebuloso 3.6 organic matter (materia organica) organ residue (88): residuo di organismo tissue (residues) (88): (residui di) tessuto organic fine material (89): materiale organico fine cells (89): cellule cell residue (89): residuo cellulare amorphous organic fine material (89): materiale organico fine amorfo punctuations (organic) (89): puntuazioni (organiche) organic pigment (89): pigmento organico monomorphic o.m. (89): materia organica monomorfica polymorphic o.m. (89): materia organica polimorfica 3.7 groundmass (massa di fondo) 3.7.1 general (concetti generali) groundmass (91): massa di fondo b-fabric (95): b-fabric (f) o fabric (f) di birifrangenza undifferentiated (95): indifferenziata crystallitic (b-fabric) (95): (b-fabric) cristallitica speckled (b-fabric) (96): (b-fabric) maculata stipple speckled (b-fabric) (96): (b-fabric) maculata a puntini mozaic speckled (b-fabric) (96): (b-fabric) maculata a mosaico striated (b-fabric) (96): (b-fabric) striata circular striated (b-fabric) (97): (b-fabric) striata circolare concentric-striated (b-fabric) (97): (b-fabric) striata concentrica crescent-striated (b-fabric) (97): (b-fabric) striata con andamento a mezzaluna crosstriated (b-fabric) (97): (b-fabric) striata incrociata granostriated (b-fabric) (96): (b-fabric) granostriata monostriated (b-fabric) (96): (b-fabric) monostriata parallel striated (b-fabric) (97): (b-fabric) striata parallela porostriated (b-fabric) (96): (b-fabric) porostriata random striated (b-fabric) (97): (b-fabric) striata disordinata strial (b-fabric) (98): (b-fabric) striale unistrial (b-fabric) (98): (b-fabric) unistriale bistrial (b-fabric) (98): (b-fabric) bistriale kinking (b-fabric) (98): (b-fabric) a cuspide 3.8 alteration (alterazione) alteration (78): alterazione isomorphous (alteration) (80): alterazione isomorfa katamorphous (alteration) (80): alterazione catamorfa mesomorphous (alteration) (80): alterazione mesomorfa alteromorph (80): alterazione alteromorfa 18 cross linear (alteration pattern) (80): (modello di alterazione) lineare incrociato dotted (alteration pattern) (81): (modello di alterazione) puntinato irregular linear (alteration pattern) (81): (modello di alterazione) lineare irregolare linear (alteration pattern) (81): (modello di alterazione) per linee patchy (alteration pattern) (83): (modello di alterazione) a macchie pellicular (alteration pattern) (80): (modello di alterazione) pellicolare cavernous residue (alteration pattern) (83): (modello di alterazione) a residuo cavernoso organized residues (alteration pattern) (83): (modello di alterazione) a residui organizzati dispersed minute residues (alteration pattern) (83): (modello di alterazione) a residui minuti dispersi tubular (alteration pattern) (81): (modello di alterazione) tubolare boxwork (83): a comparti contact void (83): vuoto di contatto septa (83): setti 3.9 pedofeatures (figure pedologiche) 3.9.1 general (concetti generali) pedofeature (101): figura pedologica matrix pedofeatures (102): figure pedologiche della matrice intrusive pedofeature (103): figura pedologica intrusiva impregnative pedofeature (103): figura pedologica di impregnazione depletion pedofeature (103): figura pedologica di svuotamento fabric pedofeature (103): figura pedologica dell’organizzazione spaziale compound pedofeatures (126): figure pedologiche composta juxtaposed pedofeatures (126): figure pedologiche giustapposte superimposed pedofeatures (126): figure pedologiche sovraimposte imbricated pedofeatures (126): figure pedologiche embricate complex pedofeatures (127): figure pedologiche complesse deformed pedofeatures (128): figure pedologiche deformate dissolved pedofeatures (128): figure pedologiche dissolte fragmented pedofeature (128): figure pedologiche frammentate kink band fabric (128): fabric a bande cuspidate 3.9.2 coatings (rivestimenti) coating (106): rivestimento hypo-coating (106): iporivestimento quasi-coating (106): quasi-rivestimento internal (hypocoating, quasicoating) (106): (iporivestimento, quasi-rivestimento) interno external (hypocoating, quasicoating) (106): (iporivestimento, quasi-rivestimento) esterno crust (107): crosta micropan (107): crosta interna capping (108): ricoprimento link capping (107): ricoprimento continuo pendent (108): pendente crescent (coating): rivestimento a mezzaluna typic (coating) (108): rivestimento tipico nonlaminated (clay coating) (109): (rivestimento di argilla) non laminato microlaminated (clay coating) (109): (rivestimento di argilla) microlaminato laminated (clay coating) (109): (rivestimento di argilla) laminato layered (clay coating) (109): (rivestimento di argilla) stratificato compound layered (clay coating) (109): (rivestimento di argilla) stratificato composto 3.9.3 infillings (riempimenti) infilling (113): riempimento dense complete (114): denso completo dense incomplete (114): denso incompleto loose continuous (114): sciolto continuo loose discontinuous (114): sciolto discontinuo passage feature (114): figura di passaggio 3.9.4 crystals (cristalli) crystal intergrowths (116): accrescimenti cristallini framboids (116): framboidi biospheroids (75): biosferoidi 3.9.5 nodules (noduli) nodule (117): nodulo aggregate nodule (119): nodulo aggregato alteromorphic nodule (119): nodulo alteromorfico dendritic nodule (119): nodulo dendritico geodic nodule (119): nodulo geodico nucleic nodule (119): nodulo nucleico septaric nodule (119): nodulo septarico typic nodule (119): nodulo tipico orthic nodule (118): nodulo ortico anorthic nodule (118): nodulo anortico disorthic nodule (118): nodulo disortico lithomorphic nodule (118): nodulo litomorfico pedomorphic nodule (118): nodulo pedomorfico macrocrystalline (47): macrocristallino / macrocristallina microcrystalline (47): microcristallino / microcristallina cryptocrystalline (47): criptocristallino / criptocristallina idiotopic fabric (120): organizzazione spaziale idiotopica xenotopic fabric (120): organizzazione spaziale xenotopica hypidiotopic fabric (120): organizzazione spaziale ipidiotopica porphyrotopic fabric (121): organizzazione spaziale porfirotopica poikilitopic fabric (121): organizzazione spaziale pecilotopica 3.9.6 intercalations (intercalazioni) intercalation (121): intercalazione interlaced (122): intrecciata serrated (122): dentellata 3.9.7 excrements (escrementi) excrement (122): escremento sphere (123): sfera ellipsoid (123): ellissoide conoid (123): conoide c. nicosia, l. trombino & g. stoops 19 tailed conoid (123): conoide caudato pointed tailed conoid (123): conoide caudato appuntito cylinder (123): cilindro bacillo-cylinder (123): bacillo-cilindro polled bacillo-cylinder (123): bacillo-cilindro smussato bipointed cylinder (123): cilindro a due punte clonocylinder (123): clonocilindro grooved plate (123): placca scanalata mitoid (123): a nastro mammilated (excrement) (123): (escremento) mammellonato tuberose (excrement) (123): (escremento) tuberoso aging (of excrements) (124): invecchiamento (di escrementi) coalescence (of excrements) (124): coalescenza (di escrementi) disintegration (of excrements) (124): disintegrazione (di escrementi) 4. bibliografia brewer r. (1964) fabric and mineral analysis of soils. john wiley & sons, new york, 470 pp. brewer r. (1976) fabric and mineral analysis of soils. robert e. krieger publ. co., huntington, ny, 482 pp. bullock p., fedoroff n., jongerius a., stoops g., tursina t. 1985 handbook for soil thin section description . waine research publications, wolverhampton, 152 pp. cremaschi m. 2000 manuale di geoarcheologia. laterza, bari, 386 pp. cremaschi m. & rodolfi g. (1991) il suolo: pedologia nelle scienze della terra e nella valutazione del territorio. nis, roma. fitzpatrick e.a. 1984 micromorphology of soils. chapman and hall, london. fitzpatrick e.a. 1993 soil microscopy and micromorphology. j. wiley & sons, chichester, 306 pp. malucelli f., gardi c. 1999 traduzione e glossario di termini usati nella micromorfologia del suolo (translation and glossary of the soil micromorphological terminology). il quaternario, 12 (1), 17-24. kubiëna w.l., 1938 micropedology. collegiate press, ames, ia, 242 pp. kubiëna w.l., 1948 entwicklungslehre des bodens. springer-verlag, vienna, 215 pp. kubiëna w.l., 1953 the soils of europe. thomas murpby & co., london, 314 pp. kubiëna w.l., 1970 micromorphological features of soil geography. rutgers university press, new brunswick, nj. stoops g. (ed.), 1986 multilingual translation of the terminology used in the “handbook for soil thin section description”. pedologie, 36 (3), 337-348. stoops g., 1994 soil thin section description: higher levels of classification of microfabrics as a tool for interpretation. in: ringrose-voase a.j., humphreys g.s. (eds.) soil micromorphology: studies in management and genesis. developments in soil science, vol. 22, elsevier, amsterdam, 317-325. stoops g., 2003 guidelines for analysis and description of soil and regolith thin sections. soil science society of america. madison, winsconsin, 184 pp. stoops g., eswaran (eds.), 1986 soil micromorphology. van nostrand reinhold company, new york, ny. ms. ricevuto il 28 aprile 2009 testo definitivo ricevuto il 10 ottobre 2009 ms. received: april 28, 2009 final text received: october 10, 2009 traduzione italiana della terminologia presente in ... base aspetti dell’evoluzione quaternaria della costa tra cogoleto e varazze (liguria occidentale) luigi carobene, andrea cevasco & marco firpo dipartimento per lo studio del territorio e delle sue risorse, genova corresponding author: l. carobene <carobene@dipteris.unige.it> riassunto: carobene l., cevasco a. & firpo m., aspetti dell’evoluzione quaternaria della costa tra cogoleto e varazze (liguria occidentale). (it issn 0394-3356, 2010) le indagini condotte nel settore costiero compreso tra cogoleto e varazze (liguria occidentale) hanno permesso di riconoscere in dettaglio forme di origine marina presenti lungo il percorso turistico che corrisponde al tracciato della ferrovia litoranea costruita alla fine dell’800. la ricerca sul terreno, oltre al rilevamento geomorfologico, ha compreso la misura dei sistemi di fratture che, successivamente, sono stati confrontati con quelli ottenuti dall’analisi delle carte topografiche e delle foto aeree. i rilevamenti effettuati hanno portato al riconoscimento di numerosi relitti di piattaforme marine sollevate che testimoniano 2 alti livelli di stazionamento compresi tra 8 e 12 m s.l.m. lungo la costa è stata, inoltre, scoperta e studiata una grotta scavata dal mare nel substrato peridotitico tra 9 e 12 m s.l.m. uno studio a carattere generale è stato effettuato sull’intero versante costiero fino al crinale pian della noia (378 m), santuario la guardia (416 m) e bric piano donne (320 m), tra i torrenti teiro e arenon, e anche nell’area a est oltre il t. arrestra; le indagini hanno consentito il riconoscimento di un “paleopaesaggio” degradato; la mappatura dettagliata di due ordini di terrazzi sollevati del pleistocene inferiore e medio (tra 60 e 125 m di quota). con i dati raccolti è stata redatta la carta delle “forme plio-quaternarie della costa tra cogoleto e varazze” (chiamata nel testo tav. i) che permette una lettura cronologica delle forme e quindi una miglior comprensione dell’evoluzione del paesaggio dal pliocene ad oggi. abstract: carobene l., cevasco a. & firpo m., aspects of the quaternary evolution of the coast between cogoleto and varazze (western liguria). (it issn 0394-3356, 2010) with the aim of recognizing marine and continental landforms in the coastal stretch between cogoleto and varazze, different kinds of investigations have been carried out. the collected data were used to draw a map (see plate); they provide a descriptive frame that allows to clarify some phases of the pliocene-quaternary evolution of the area. 1) the relic of a pliocene paleo-landscape. it’s partially shown in plate and in fig. 1 by a series of topographic summits, mostly between 300 and 400 m in elevation, which originated from the progressive emersion of the area since the middle pliocene. 2) the quaternary landscape. from a morphological point of view it appears well distinguishable from the pliocene landscape (fig. 3) because of the presence of several marine terraces (see plate). considering the average quaternary uplift rate (equal or less than 0.1 mm/y – cap. 5), the relicts of the quaternary surface cannot occurr over the elevation of 180 m. between 180 m and the altitude of the 1st order terrace’s inner margin (95-100 m, see plate, central stretch), marine terraces are not visible because of the slope’s intense regularization. distinct and well-represented is the first order terrace, which still preserves marine deposits (inner margin’s altitude 90÷115 m); its age has been attributed to the late lower pleistocene (1.2-0.9 m.y.). less obvious but still represented is the second order’s terrace, whose inner margin is located at 65 meters a.s.l.. 3) the rocky band located between 0 and 12 meters. along the coast, between the sea level and a tourist path located in correspondence to the route of the railway built in the late 1800s (europa promenade), a rocky band (gabbros and peridotite) preserving remains of terraced marine areas appears; this indicates two paleo shore-lines located at 8 and 12 m elevation, respectively (see plate, profiles s1 to s4). marine deposits constituted by sands and rounded pebbles and, locally, by rounded boulders (often with diameters larger than 1 meter), are kept isolated in small flaps. the level at 7.5÷8 m has been attributed to the tyrrhenian (mis 5.5) (fig. 7). 4) the coastal slope. the slope has been divided into altitudinal sections with distinct morphological aspects and attributed to different ages. the oldest and most settled side (vc. in plate) stretches between 250 meters and 95÷105 meters elevation with an average inclination of 25° (see tab. 1); between 70÷80 meters (external edge of the 1st order terrace) and the sea level is a band (vc.t1 in plate) with an angle between 22° and 32°. between 50÷55 meters (outer edge of the 2nd order terrace) and the sea level is a steeper and irregular sector (vc.t2 in plate) with an inclination between 27° and 37°. 5) the coastal plains. the arrestra and teiro plains (partially visible in plate) present: the oldest side (medium and late pleistocene) between 10 meters and 25 meters in height, characterized by a thick toe of slope deposits (mainly colluvium) with evidence of strong rubefaction; a lower part (holocene) between 5 and 10 meters; a beach between 5 meters and the sea level. 6) the mizar cave. it is a marine cave, between 9 and 12 meters in height, entirely excavated in peridotite rocks. the interior walls have very regular profiles (similar to parables); its formation is referable to the tyrrhenian eustatic highstand. the dominant erosive process is related to the waves abrasion during storm surges (figs. 16 e 13). 7) the plio-quaternary vertical dislocations. the present day coastal area is the result of a moderate lifting that began in middle pliocene; in contrast, the marine platform area has been lowered. the two areas are divided by tectonic lines stretching 56°-57° (ca. ene-wsw) e 21°-22° (ca. nne-ssw) (fig. 1 e plate). it was possible to calculate an average rate of plio-quaternary uplift not exceeding 0.2 mm/year and an average rate of quaternary lifting less than 0.1 mm/year. 8) the disjunctive tectonics. all the landforms in this area, and particularly the hydrographic network, have been controlled by active plio-quaternary faults and fractures. the “teiro fault” (partially visible in fig. 1), futhermore, shows greater evidence and significance; its effect determined the rise of the eastern sector over the western one. in this area the dislocations are testified by changes in the height of first order marine terraces, in which the inner margin increases from 80 to 95 metres.. the tectonic features, derived from the hydrographic network analysis are more fragmented and discontinuous to the east of the “teiro fault”. however it has been possible to recognize three fault/fracture sets characterized by different directions: 55-60°; 21-23°; 125-136°. these directions are confirmed by field surveys carried out along the rock band situated down the “europe promenade” (fig. 17). 9) the valley cut. the main rivers of this area (rio mola, rio partigliolo, t. arrestra – see plate) have a uniform and very high inclination in the lower part, which differs significantly from that of the higher part (vv. in tab.1). this is the consequence of the valley deepening during the quaternary. the obtained results, which were briefly listed above, provide new and sufficiently detailed evidences for clarifying the evolution of the area from a morphological, genetic and chronological point of view. in conclusion, the landscape we see today began its formation in the middle pliocene and evolved over time. it changed its shape under the actions of tectonic events and both continental and marine exogenous processes. parole chiave: antiche linee di riva, grotta marina, morfologia costiera, paleosuperficie, terrazzi marini, tettonica quaternaria, tirreniano, versanti. keywords: ancient shore lines, coastal morphology, marine terraces, mis 5.5, paleosurface, quaternary tectonics, sea cave, slopes. il quaternario italian journal of quaternary sciences 23(2), 2010 163-180 164 l. carobene, a. cervasco & m. firpo 1. premessa il “lungomare europa”, che si snoda all’interno del parco costiero dei piani d’invrea, è uno straordinario percorso che corrisponde al vecchio tracciato della ferrovia, ultimata nel 1868. la ferrovia fu costruita ai piedi del versante che si raccorda all’orlo esterno dei terrazzi marini sovrastanti; tra la ferrovia, posta alla quota di 7-8 metri, ed il mare si estende una stretta fascia rocciosa, costituita da gabbri e peridotiti serpentinizzate, soggetta all’erosione marina dell’alto eustatico attuale. da qui è partito lo studio dell’area: uno studio dettagliato e quantitativo che ha preso in considerazione tutte le forme del paesaggio riconoscibili (rilievi, versanti, terrazzi marini, reticolo idrografico, insenature, piane costiere, ecc.). sono state misurate quote, direzioni, dimensioni e pendenze. ciò ha consentito di riconoscere elementi di novità, quali i relitti delle piattaforme marine presenti tra 6 e 12 m sul livello marino, una grotta marina scavata nelle peridotiti, un paesaggio pliocenico rimodellato. è stato riconosciuto il ruolo della tettonica, che si è manifestata con movimenti verticali e con sistemi di faglie e fratture, producendo vistosi effetti morfogenetici. tutti gli elementi così raccolti sono stati riportati in una tavola, che permette di riconoscere la progressiva genesi delle forme del paesaggio, dal pliocene ad oggi. 2. cenni di geologia l’area di studio è caratterizzata dalla presenza di litotipi metamorfici di alta pressione appartenenti al gruppo di voltri (tav. i). quest’ultimo, come noto, comprende un complesso di metaofioliti e metasedimenti e rappresenta l’estrema porzione meridionale del dominio pennidico delle alpi occidentali; sotto il profilo strutturale, il complesso è definito come un sistema composito di falde metamorfiche, situato in posizione interna rispetto all’arco alpino occidentale e corrispondente all’esumazione di un livello crostale profondo (vanossi et al., 1986; s.g.i., 1991; capponi et al., 1994). l’evoluzione strutturale è determinata da tre successivi eventi plicativi, espressi da strutture duttili sovrapposte; l’evoluzione metamorfica è caratterizzata da un climax in facies “scisti blu” con eclogiti, di età compresa fra 49 e 45 m.a. (hoogerduijn strating, 1990; federico et al., 2005), cui sono seguiti vari stadi di riequilibratura pressoché adiabatica con pressioni decrescenti, fino a condizioni di “scisti verdi”, con età intorno a 33 m.a. (aa.vv., 1996; federico et al., 2005). a tali strutture compressive si sovraimpone nel pliocene-quaternario una neotettonica di tipo distensivo che interessa anche l’area del margine continentale (fanucci & nosengo, 1979). la zona considerata si solleva dal pliocene medio mentre la piattaforma continentale subisce abbassamento (cortellesi et al., 1979). lungo la “passeggiata europa” affiorano, in particolare, litotipi metamorfici in facies “scisti verdi” che costituiscono le formazioni dei metagabbri e dei serpentinoscisti, appartenenti all’unità ofiolitica di varazze (giurassico) (regione liguria, 1997). quest’ultima costituisce un’unità tettonica addossata al margine meridionale dell’unità del m. beigua e in posizione geometricamente ribassata rispetto a quest’ultima, ad opera di un fascio di faglie orientate e – w (provincia di savona, 2007). nella zona occidentale dell’area indagata (lungo la costa da varazze al rio corvo circa) affiorano metagabbri in facies di scisti verdi, a scistosità più o meno evidente, mentre nella zona orientale (lungo la costa fino a cogoleto) affiorano peridotiti serpentinizzate, da compatte a marcatamente scistose e fissili, con intercalazioni di metarodingiti derivate da originari filoni gabbrici e con lenti di lherzoliti non completamente serpentinizzate (regione liguria, 1997). 3. aspetti morfologici della fascia costiera i tratti salienti della fascia costiera, indagata dalla quota di 300-400 metri fino al mare, ed estesa dalla cittadina di cogoleto a levante a quella di varazze a ponente, sono i seguenti (tav. i): 1) i versanti a monte del terrazzo del 1° ordine (vps. e vc.); 2) il terrazzo marino del 1° ordine con margine interno a 70÷115 m (t1); 3) il terrazzo marino del 2° ordine con margine interno a 65÷70 m (t2); 4) i versanti a valle dei due terrazzi marini (vc.t1 e vc.t2); 5) i versanti vallivi (vv.); 6) le piane costiere (pc1, pc2, pc3); 7) la stretta fascia rocciosa (fc2) che fiancheggia verso mare il vecchio tracciato della ferrovia (f). 3.1. i versanti a monte del terrazzo del 1° ordine il tratto di costa esaminato è compreso tra il rio mola a so e il t. arrestra a ne. al suo interno il rio partigliolo (o arenon) suddivide la costa in due settori: il primo si estende tra punta della mola e punta d’invrea; il secondo è quello compreso tra il rio partigliolo ed il t. arrestra. il versante costiero a monte del terrazzo del 1° ordine presenta due aspetti morfologici differenti, suddivisi in un tratto superiore e in un tratto inferiore. 3.1.1. il tratto superiore del versante costiero (vps.) è caratterizzato da un progressivo distanziarsi delle isoipse a partire dalla quota di 250 m e dalla presenza di culminazioni (lungo il crinale: santuario la guardia, 416 m; bric piano donne, 320 m; passo frese, 254 m) (tav. i). tutta una vasta area a n del crinale citato presenta numerose altre culminazioni del paesaggio, tutte comprese tra 250 m (bric meazze, 253 m; bric berlese, 263 m, ecc.) e 380 m (bric noia, 378 m; bric arenon, 380 m; monte costea, 342 m, ecc.) (fig. 1). questi relitti morfologici sono la testimonianza di una originaria superficie di spianamento, considerata una “paleosuperficie” di età pliocenica (ps in tav. i e figg. 2 e 3) in quanto si estende interamente al disotto della presunta quota della paleo-linea di riva del pliocene inferiore (500 – 550 m), ottenuta tenendo conto della profondità di sedimentazione delle argille del pliocene inferiore e della loro attuale quota di affioramento. la quota così calcolata è in accordo con quella riportata da fanucci & tedeschi (1983) e fanucci (1988). tre sezioni rappresentative del versante costiero alto (vps.1, vps.2 e vps.3) hanno fornito valori di inclinazione (tab. 1) di 16°, 20° e 21°, con un valore medio di 19°; le inclinazioni tendono a diminuire nella parte più alta del versante. 3.1.2. tratto inferiore del versante costiero (vc.) il tratto, compreso fra il rio mola e il torrente arrestra, si estende dalla quota del margine interno del terrazzo del 1° ordine, quindi da 90-105 m circa, fino ad una quota media di 250 m. esso corrisponde ad un versante regolarizzato, con inclinazione quasi costante; la sua omogeneità è interrotta da brevi corsi d’acqua perpendicolari alla linea di costa. la misura dell’inclinazione del versante costiero effettuata in 3 punti distinti (vc.1, vc.2, vc.3 in tav. i e in tab. 1) ha fornito valori simili, la cui media è pari a 25°. la parte più bassa del versante mostra localmen165aspetti dell’evoluzione quaternaria della costa ... te una diminuzione dell’inclinazione, che testimonia la presenza di depositi di piede di versante; essi si presentano fortemente pedogenizzati e con spessori di parecchi metri. il tratto di versante compreso tra il rio partigliolo e il t. arrestra è costituito da uno stretto crinale che da bric san giacomo (149 m), sale verso bric meazze (253 m, fuori tavola). più complessa la situazione in sinistra del t. arrestra (in gran parte fuori tavola, vedi però fig. 1), caratterizzata da un lungo tratto di crinale suborizzontale compreso tra le quote di 165 (loc. serbatoio) e di 175-180 m (superficie terrazzata di prato zanino). da notare che, a causa della tettonica disgiuntiva quaternaria, il margine interno del terrazzo del 1° ordine si ritrova qui alla quota di 115 m (tav. i). fig. 1 i lineamenti dedotti dall’analisi del reticolo idrografico e dalle direzioni della costa (paragr. 5.2) hanno permesso di riconoscere 3 sistemi con direzioni: 1) 21-23°; 2) 55-60°; 3) 125-136°. sono indicate con la loro quota (dedotta dalla carta topografica al 25.000) tutte le culminazioni presenti nell’area. le 16 culminazioni comprese tra 380 m e 252 m sono state ritenute relitti di una “palosuperficie pliocenica” (paragr. 3.1). quattro culminazioni, inoltre, sono comprese tra 416 e 471 m. la carta riporta il reticolo idrografico con la denominazione di ogni singolo corso d’acqua. legenda: 1= culminazioni topografiche; 2=lineamenti certi; 3= lineamenti probabili; 4 e 5= faglie costiere certe e probabili; 6= superficie terrazzata di prato zanino, attribuita al pleistocene inferiore. the tectonic lines derived from the analysis of the hydrographic network and of the coastline directions (paragr. 5.2) allowed us to recognize 3 systems with directions: 1) 21-23 °; 2) 55-60 °; 3) 125-136 °. the summits within the study area and their elevation (deduced from the topographic map at scale 1:25.000) are shown in the map. the 16 culminations with elevation between 380 m and 252 m were considered relics of a "pliocenic palosurface" (paragr. 3.1). moreover, four summits are located between 416 m and 471 m a.s.l.. the map shows the hydrographic network and the name of each watercourse. legend: 1 = summits; 2 = certain tectonic lines; 3 = uncertain tectonic lines; 4 and 5 = certain and uncertain coastal faults, 6 = prato zanino terraced surface, attributed to the lower pleistocene. 166 3.2. il terrazzo marino del 1° ordine la quota del margine interno di questo ordine terrazzato (vedi carobene & firpo, 2002) aumenta progressivamente da so a ne, da savona a genova; nel settore costiero esaminato tale quota sale da 70 a so fig. 3 il profilo a-b mette in evidenza gli aspetti più caratteristici presenti nell’area studiata (tav. i) e in particolare: vps.= versante costiero della paleosuperficie pliocenica; vc.= versante costiero a monte del terrazzo del i ordine; t1 e t2= terrazzi marini del 1° e del 2° ordine; le piattaforme marine (pm.) hanno i margini interni (mi.) a 85 m in t1 e a 55 m in t2. i corpi terrazzati (ct.) sono costituiti da depositi marini ricoperti da colluvium e colate detritiche; vc.t2 è il versante costiero a valle del terrazzo t2. il piede del versante è qui a 15 m, ma in generale è a 10 m. al disotto di questa quota si estende il “lungomare europa” (pe). nella riga in basso sono riportati i valori delle inclinazioni (confr. con tab. 1) mentre nella riga in alto è segnato il limite tra il paesaggio pliocenico (p.p.) e quello quaternario (p.q.). the a-b profile highlights the most typical features of the study area (see plate). they are specifically: vps.= coastal slope of the pliocene paleosurface; vc.= coastal slope above the first order terrace; t1 and t2 = 1st and 2nd order marine terraces; marine platforms (pm.) have their inner margins (mi.) at 85 m in t1 and at 55 m in t2. the terraced bodies (ct.) are composed of marine deposits covered with colluvium and debris flow materials; vc.t2 is the coastal slope below the coastal terrace t2. the toe of the slope is here at 15 m a.s.l., but generally his elevation is 10 m. below this altitude the “europa promenade” (pe) is located. in the bottom row the values of inclination are shown (cfr. table 1) while in the top line the boundary between the pliocene landscape (p.p.) and the quaternary landscape (p.q.) has been marked. (loc. varazze), a 115 m in sinistra del t. arrestra (località cogoleto). tale variazione può essere stata causata da un progressivo maggior sollevamento dell’area di ne rispetto a quella di so (basculamento), ma le osservazioni portano a ritenere più probabile l’attività di faglie disposte circa no-se (direz. 130-310°) (vedi cap. 5). queste sono anche responsabili della frammentazione dell’originario terrazzo marino in tante distinte “superfici terrazzate”, separate da brevi rivi (tav. i). lo studio dettagliato dell’orlo esterno delle varie superfici terrazzate relitte ha inoltre portato a riconsiderare la loro reale estensione e ha evidenziato la presenza di una leggera scarpata tra le quote di 65 e 75 m, che origina due superfici terrazzate distinte. tale scarpata non è riconoscibile sulla superficie del castello d’ivrea, probabilmente per cause antropiche. la superficie di separazione tra il 1° e il 2° ordine è stata in questo caso messa a +70 m, per analogia con le altre situazioni osservate a so. le superfici terrazzate marine, limitate a monte dal “margine fig. 2 la paleosuperficie pliocenica vista da nord, profondamente incisa dai corsi d’acqua. view from the n of the pliocenic paleosurface, which appears deeply incised by the rivers. l. carobene, a. cervasco & m. firpo 167 interno”, sono limitate verso mare dal così detto “orlo esterno”; nel considerare la sua quota occorre tener presente che l’andamento dell’intero limite di una superficie terrazzata ha due origini diverse: la prima deriva dall’arretramento costiero causato dalla genesi del terrazzo marino immediatamente più basso; la seconda deriva invece dallo sviluppo delle incisioni vallive causato dal sollevamento dell’area. nella tav. i è evidenziata questa differenza con due simboli diversi; nei calcoli sulle quote o sull’estensione dei terrazzi va considerato, ovviamente, l’orlo esterno che coincide con il limite superiore della “paleofalesia “ degradata sottostante. nell’area, l’orlo esterno di questo 1° ordine di terrazzi risulta variare tra 70 e 90 m (da so a ne) di quota. la superficie terrazzata presenta sempre una buona copertura sedimentaria; il deposito marino è costituito in prevalenza da ghiaie e ciottoli, con spessore massimo riscontrato di 4-6 metri. i clasti, sempre ben arrotondati, possono raggiungere in determinate località il diametro di 50-100 cm; frequente la forma appiattita in litotipi scistosi. in superficie è sempre presente la copertura continentale, data da depositi colluviali limosi o da clasti spigolosi in matrice limosa derivanti da colate detritiche tipo debris-flow. il loro spessore aumenta dall’orlo esterno verso il margine interno, dove può superare i 5 metri. ciò permette di dedurre che la quota del margine interno “morfologico” del terrazzo è sempre più alto di diversi metri del limite interno della piattaforma marina (“paleo-linea di riva geometricamente determinata” in carobene, 2003). un esempio in località la vignetta (superficie terrazzata a nord di punta della mola fig. 8 in carobene & firpo, 2002) mostra un margine interno morfologico collocabile tra 90 e 95 m s.l.m., mentre il margine interno riferito alla superficie inferiore del terrazzo (piattaforma marina) è ad una quota (ricostruita geometricamente) di 82 m. in base al deposito marino presente (spessore di circa 5 metri), la paleolinea di riva si può porre a 85 m circa. pertanto le quote del margine interno segnate in tav. i sono sempre “valori in eccesso”. la presenza di colluvium ha reso quasi sempre impossibile misurare la quota della paleo-linea di riva. i depositi marini e continentali terrazzati si presentano fortemente pedogenizzati (colori prevalenti compresi nella tavola munsell 2.5 yr). sulla base di considerazioni morfologiche e dei tassi di sollevamento dedotti dagli affioramenti argillosi del pliocene inferiore, il terrazzo del 1° ordine è stato attribuito da carobene & firpo (2002) ad un generico pleistocene inferiore (probabilmente finale); in base alle quote presunte della paleolinea di riva (85-95 m, escludendo le superfici terrazzate a 115 m e quelle a 70-80 m), il tasso del sollevamento potrebbe avere valori compresi tra 0,08-0,1 mm/anno. 3.2.1. relitti di terrazzi più alti del 1° ordine l’unica testimonianza di un terrazzo marino più alto di quello del 1° ordine sopra descritto è un relitto di superficie con margine interno a +140 m, visibile in destra idrografica del rio pescatori (pi in tav. i). la copertura continentale non ha permesso di riconoscere l’eventuale deposito marino; in particolare, il margine interno è caratterizzato da depositi colluviali molto arrossati. in sinistra idrografica, il dosso chiamato bric san giacomo (quota 149 m) potrebbe costituire una ulteriore testimonianza. un terrazzo marino (che non è stato oggetto di studio) sembra essere la vasta area suborizzontale chiamata prato zanino, in sinistra del t. arrestra (non visibile in tav. i, ma riportato in fig. 1), con margine interno a 180 metri. poiché il tasso di sollevamento medio quaternario è stato ritenuto pari o minore di 0,1 mm/a (cap. 5), la quota di 180 metri potrebbe indicare che questo vasto terrazzamento si è formato all’inizio del pleistocene inferiore. 3.3. il terrazzo marino del 2° ordine nell’area esaminata sono stati evidenziati 8 relitti di superfici terrazzate comprese tra un orlo esterno a circa 55 metri ed un margine interno a 65-70 metri (tav. i). la corrispondente paleolinea di riva è collocabile alle quote di 55-60 metri a causa delle coperture marinocontinentali esistenti. lo scalino (paleofalesia degradata) che separa questo ordine terrazzato da quello immediatamente più alto, non è sempre facilmente individuabile a causa dell’urbanizzazione e dei processi di degradazione subiti dalle superfici (tav. i). l’ampiezza delle superfici relitte varia tra 50 e 150 tab. 1 valori di inclinazione dei versanti (tav. i). slopes dip angle values (see plate). aspetti dell’evoluzione quaternaria della costa ... 168 metri; lo studio dei depositi terrazzati è difficilmente effettuabile a causa dell’antropizzazione. il forte rimodellamento subito da questo ordine terrazzato è stato causato dall’azione distruttrice degli alti livelli eustatici successivi, che hanno prodotto un consistente arretramento costiero; il processo erosivo è stato accentuato dal basso tasso di sollevamento dell’area (bosi et al., 1996). ciò può aver prodotto, localmente, la totale scomparsa del terrazzo del 2° ordine. per attribuire un’età probabile a questo terrazzo va ricordato che la linea di riva del pleistocene superiore (125.000 anni) non supera tra savona e genova (carobene & firpo, 2002) la quota di 8 metri (vedi anche cap. 4); pertanto il tasso di sollevamento deducibile è inferiore a 0,03 mm/a (considerando pari a +4 l’originaria quota). la velocità di sollevamento è quindi diminuita nel tempo. il terrazzo del 2° ordine, più basso di circa 30 m rispetto al precedente (e per tale ragione più recente), deve aver subito un sollevamento con un tasso minore di 0,08 – 0,1 mm/a (attribuito al terrazzo di 1° ordine). assumendo, ad esempio, valori pari a 0,07 – 0,09 mm/a, l’età del terrazzo del 2° ordine cadrebbe tra 700 e 800.000 anni circa. 3.3.1. altri ordini di terrazzi le ricerche sul terreno non hanno evidenziato altri terrazzi marini “sicuri”, più bassi del 2° ordine sopra descritto. un relitto di terrazzo potrebbe essere la superficie con margine interno a 35 m, segnalata in tav. i (pm), ma non sono state trovate prove certe della sua origine. 3.4. i versanti a valle dei terrazzi marini in generale sono presenti due differenti situazioni: un unico versante che dall’orlo esterno del terrazzo del 1° ordine arriva al mare, oppure due distinti tratti di versante, qualora siano presenti entrambi gli ordini terrazzati. il più ampio di questi si estende dall’orlo esterno del terrazzo del 1° ordine al livello del mare (vc.t1); il più basso, dall’orlo esterno del terrazzo del 2° ordine alla linea di riva attuale (vc.t2). non è stata presa in considerazione la stretta striscia di versante compresa tra i terrazzi del 1° e del 2° ordine. in sinistra del t. arrestra il versante, visibile in tav. i, va dall’orlo esterno del terrazzo del 1° ordine al margine interno (a 25 m s.l.m.) della piana costiera terrazzata. per comodità di trattazione, la descrizione è fatta per settori costieri (tav. i); la parte più bassa del versante, ovvero la stretta fascia rocciosa a valle dell’antica linea ferroviaria viene descritta separatamente (cap. 4). sempre per comodità di esposizione, sono stati utilizzati nuovi toponimi (riportati in tav. i): rio vignetta, rio sant’ambrogio, rio donne, punta delle donne e punta dei pescatori, privi di nome nella c.t.r. alla scala 1:5.000. l’inclinazione dei versanti è stata calcolata dall’orlo esterno dei terrazzi alla quota di +10 m, posta a monte della vecchia ferrovia, in modo da escludere le piattaforme di abrasione ritenute tirreniane (fc2); fa eccezione la sez. vc.t2.1. 3.4.1. il settore costiero a-b corrisponde alla tangente al tratto di costa compreso tra la fine della spiaggia in destra del t. arrestra e punta alberto; la direzione è di 21° (tav. i). il terrazzo del 2° ordine è assente; il versante costiero è inclinato di 27° (vc.t1.2 tab.1). si presenta comunque irregolare, in quanto solcato da due brevi corsi d’acqua che non attraversano il terrazzo a monte, ma ne erodono parzialmente il suo orlo esterno. 3.4.2. il settore costiero b-c corrisponde alla tangente tra punta delle donne e punta d’invrea; la sua direzione è di 56°. la tangente evidenzia un tratto di costa che ha subito maggior arretramento, interno all’arco punta delle donne punta dei pescatori; il terrazzo del 2° ordine è comunque sempre presente, pur smembrato dal rio pescatori e dal rio donne. il valore più alto di inclinazione del versante è stato calcolato in corrispondenza della punta dei pescatori (sez. vc.t2.1 = 37°) dove è assente anche la piattaforma di abrasione. la sez. vc.t2.2, in posizione più protetta, ha fornito un valore di 28° (tab. 1). l’inclinazione massima del versante si riscontra alla punta d’invrea, dove è presente una vera e propria falesia, con valori di inclinazione fino a 60°. 3.4.3. il settore costiero c-d corrisponde alla tangente tra punta della mola e punta delle donne; la sua direzione è di 66° (tav. i). detta tangente è “la corda” di un arco costiero che ha il suo punto di massima rientranza in corrispondenza della foce del rio corvo. in questo tratto l’arretramento costiero ha fatto scomparire tutte le forme terrazzate comprese tra l’orlo esterno del terrazzo del 1° ordine e il tracciato della ferrovia. ciò si riflette sull’inclinazione del versante che presenta un valore di 32° (sez. vc.t1.3 tab. 1). in corrispondenza di punta della mola, dove l’arretramento è stato minore, l’inclinazione è invece di 22° (sez. vc.t1.4). nei punti dove sono conservati relitti del terrazzo del 2° ordine, il versante a valle di essi ha valori di inclinazione compresi tra 27 e 33° (sezioni da vc.t2.6 a vc.t2.3, tab. 1). questo primo settore mette subito in evidenza la varietà degli aspetti del versante che si sviluppa tra la vecchia ferrovia e l’orlo esterno del terrazzo del 1° ordine (quota 70-85 m), caratteristica che emergerà anche nei settori successivi. 3.4.4. tratto costiero in sinistra del t. arrestra anche in questo tratto è assente il terrazzo del 2° ordine, e il versante è compreso tra l’orlo esterno del terrazzo del 1° ordine e il margine interno (a +25 m) della sottostante superficie terrazzata. l’inclinazione misurata in vc.t1.1 ha dato un valore di 26°. 3.4.5. considerazioni sintetiche i tratti di versante estesi a valle dell’orlo esterno dei terrazzi del 1° e del 2° ordine si presentano irregolari e con pendenze variabili. il versante più ampio, tra la quota di +10 m circa e l’orlo esterno del terrazzo del 1° ordine, presenta un valore medio di inclinazione di 27°; il tratto di versante più basso, tra l’orlo esterno del terrazzo del 2° ordine e la quota di +10 m, ha una inclinazione maggiore che, mediamente, risulta di 31°. è possibile quindi dedurre che il versante più giol. carobene, a. cervasco & m. firpo vane è meno regolarizzato e più inclinato, risentendo maggiormente, rispetto a quello più antico, degli effetti dell’arretramento costiero verificatosi nel pleistocene superiore. attualmente i versanti risultano stabilizzati sia dalla vegetazione, sia dai numerosi interventi legati all’urbanizzazione dell’area. in particolare un ruolo protettivo importante ha avuto la costruzione del tracciato ferroviario a fine ’800. le caratteristiche morfologiche descritte (versanti costieri e terrazzi marini) sono ben rappresentate nella fig. 3 (profilo a-b in tav. i), mentre la tab. 1 riassume, da un punto di vista quantitativo, la variazione delle inclinazioni dal versante più basso (vc.t2) al versante costiero più alto (vps.). 3.5. i versanti vallivi un altro aspetto morfologico rilevato è quello relativo ai versanti vallivi. con riferimento ai tre corsi d’acqua principali presenti nell’area studiata si è osservato che la parte bassa dei versanti ha una pendenza costante e superiore a quella del tratto sovrastante. questo aspetto è stato quantificato mediante la misura di 6 sezioni (tav. i) denominate vv.3 (rio mola), vv.2 (rio partigliolo) e vv.1 (t. arrestra). i valori dell’inclinazione sono stati calcolati sia per i versanti in sinistra idrografica, sia per quelli in destra (tab. 1). il campo dei valori trovati varia tra 29 e 40°, con una media di 34°; questo valore è superiore a quello medio di tutti i versanti a valle del terrazzo del 1° ordine (29°), e decisamente più alto di quello medio del versante costiero a monte del terrazzo del i ordine (vc. = 25°), e ancor più del versante appartenente alla paleosuperficie pliocenica (vps. = 19°). ciò testimonia l’approfondimento “recente” dei corsi d’acqua, successivo alla formazione e al sollevamento del terrazzo del 1° ordine. 3.6. cenni sulle piane costiere il tratto costiero dove si sviluppa il lungomare europa è caratterizzato dalla “fascia rocciosa” (fc2). tale fascia è limitata a ne dalla piana costiera del t. arrestra e a so dalla piana del t. teiro, parzialmente visibili in tav. i. le piane si innalzano fino a 25 m circa, quota che si riferisce alla base del versante costiero che si estende (in generale) fino all’orlo esterno del terrazzo del 1° ordine (vc.t1). nella fascia che si estende da 25 m al mare si possono riconoscere 3 unità morfo-sedimentarie: pc1 la piana alta, tra 10 e 25 m s.l.m.; pc2 la piana bassa, tra 5 e 10 m; pc3 la spiaggia emersa, tra 5 e 0 m. la prima è caratterizzata da imponenti depositi di piede di versante, pedogenizzati e con spessori che possono raggiungere i 10 metri. questo corpo sedimentario è stato troncato verso mare dalla risalita eustatica olocenica, che ha dato origine alla piana più bassa (pc2) per progradazione della spiaggia avvenuta nel corso degli ultimi millenni; la parte superiore di questa piana è costituita da parecchi metri di depositi alluvionali e colluviali. la terza unità è la spiaggia attuale (pc3), sabbioso – ciottolosa, con tendenza all’arretramento. là dove questo fenomeno è avvenuto, anche la piana pc2 risulta troncata verso mare. 4. tratto di costa rocciosa a mare del vecchio tracciato della ferrovia lungo il percorso stradale, corrispondente al tracciato della vecchia ferrovia, si possono osservare forme e depositi, riferibili in gran parte al pleistocene superiore olocene, di origine sia marina che continentale. nel primo paragrafo vengono descritti 4 profili (sezioni geologiche s1 s4 in tav. i) che hanno fornito informazioni determinanti per la comprensione degli eventi che hanno modellato la costa. nel secondo paragrafo (4.2.) sono esposte sinteticamente osservazioni effettuate lungo il percorso, utili per completare le considerazioni emerse dall’analisi dei 4 profili. nel terzo paragrafo (4.3.) è riportata la descrizione di rientranze della paleofalesia, ritenute “paleo-insenature marine”. 4.1. descrizione delle sezioni geologiche la descrizione parte da ne, in destra del torrente arrestra, e termina a so, in corrispondenza del molo nautilos, dove inizia la piana alluvionale-costiera del torrente teiro (tav. i). i valori delle giaciture relative alle fratture sono sempre riferiti al nord e misurati in senso orario. per brevità verrà indicato il solo valore dell’angolo; pertanto la misura n70°e verrà indicata con 70°, ecc. 4.1.1 sezione s1 (tav. i) la sezione è stata effettuata all’inizio del tratto di costa rocciosa immediatamente a sso della spiaggia sabbioso-ghiaiosa in destra della foce del t. arrestra (fig. 4). le misure di quota sono state eseguite con stadia e livello autolivellante; sono stati utilizzati punti quotati della c.t.r alla scala 1:5000, il livello marino medio ed indizi morfologici di quest’ultimo. si presume che le misure siano affette da un errore non superiore a ±30 cm. questo primo tratto di costa (ab) si sviluppa in direzione 21°, condizionata da un netto e fitto sistema di fratture che interessano il substrato, costituito da peridotiti nero-bluastre, più o meno serpentinizzate; oltre a questo, sono stati misurati i seguenti sistemi: dir. 10°, 45°, 70°, 110-112°, 132°, 170°. le inclinazioni variano in preferenza tra 75 e 85°; le immersioni possono anche essere opposte. dall’esame delle foto aeree sono stati ricavati i sistemi: dir. 40-45°, 76°, 94°, 114°, 175°. nella s1 sono evidenziati soprattutto i sistemi (sf) a 45° e a 170-190°. i sistemi di fratture ritrovati hanno condizionato l’erosione del promontorio e quindi giustificano la sua attuale forma. aspetti della piattaforma di abrasione (pa) l’ampiezza della piattaforma è di circa 50 metri; l’orlo esterno è a 5,50 m, mentre il margine interno è a 7,20 m s.l.m. solamente la parte verso terra della piattaforma è ricoperta da un lembo relitto di depositi, sia marini che continentali. la parte verso mare appare completamente rimodellata dal moto ondoso e dall’erosione subaerea in genere, favorita dai fitti sistemi di fratture. la superficie ricoperta dai depositi si presenta ben lisciata dal moto ondoso. la piattaforma termina contro un relitto della paleofalesia, troncata a monte dalla costruzione della 169aspetti dell’evoluzione quaternaria della costa ... massicciata ferroviaria. i depositi come si è detto, la parte interna della piattaforma è coperta da un lembo relitto dell’originario deposito terrazzato, per una ampiezza massima di circa 3540 metri. a) il deposito marino lo spessore è variabile, raggiungendo il suo massimo (circa 130 cm) in corrispondenza di depressioni del substrato. il sedimento è costituito quasi esclusivamente da ghiaie e ciottoli; nella parte inferiore sono presenti massi isolati con diametro massimo visibile di circa 1,5 m, ben l isciati dal moto ondoso, mentre i diametri prevalenti oscillano tra 5 e 15 cm, ma possono arrivare fino a 35 cm (fig. 5). nella parte intermedia i diametri sono compresi tra 1 e 6 cm, mentre il diametro prevalente è di 4 cm. le dimensioni aumentano nella parte alta del deposito, con diametri fino a 10-15 cm; ciò potrebbe indicare la fase regressiva finale. la forma dei ciottoli più frequente è prismatica allungata; ellissoidale o subsferica irregolare; meno frequentemente discoidale o prismatica appiattita. l’embriciatura è prevalentemente verso mare, ma non mancano casi di ciottoli immergenti verso terra. l’arrotondamento è variabile, prevalentemente buono o molto buono; presenti anche ciottoli poco arrotondati. la litologia è monotona, data quasi esclusivamente da peridotiti più o meno serpentinizzate; esteriormente i ciottoli presentano una patina superficiale biancastra. la struttura del deposito è clasto-sostenuta, anche se gli interstizi sono riempiti da limi pedogenizzati di origine secondaria. le ghiaie marine passano bruscamente al sovrastante deposito continentale. b) il deposito continentale è un lembo relitto di deposito di piede di versante, esteso tra 6 e 16 metri circa; il massimo spessore osservabile è di 8 metri. l’inclinazione verso mare della superficie del deposito è di 35°. gli aspetti tessiturali e strutturali sono osservabili 170 fig. 4 veduta del piccolo promontorio dove è stata eseguita la sezione s1 (tav. i). a destra si estende verso mare la piattaforma priva di sedimenti (par), fortemente erosa e dove sono visibili le tracce di due importanti sistemi di fratture (f) (vedi sezione s1). a sinistra la piattaforma è invece ricoperta (pa) dai depositi marini e continentali (dmc). visibile anche il percorso dell’antica ferrovia dell’800 (f). view of the small promontory where the section s1 has been traced (see plate). on the right the platform (par) extends itself toward the sea. no sediments stand upon the platform because of the strong erosion; the traces of two fracture systems (f) are visible (see section s1). on the left the platform (pa) is covered by marine and continental deposits (dmc). the path of the railway built in the xix century (f) is shown too. fig. 5 la superficie ben lisciata della piattaforma marina (sm) taglia il substrato (p) costituito da peridotiti serpentinizzate color verde-scuro. il top della superficie è (in questo punto) alla quota di 7 m circa. il deposito marino (dm) ha spessore variabile ed è costituito da clasti arrotondati (vedi figg. 5 e 7) e da radi massi. depositi colluviali antichi (ca) ricoprono il deposito marino (vedi paragr. 4.1.1.). the smoothed surface of the marine platform (sm) cuts the bedrock (p) consisting of dark-green serpentinized peridotite. the top of the surface is at this locale at about 7 m a.s.l.. the marine deposit (dm) has variable thickness and consists of rounded pebbles (see figg. 5 and 7) and sparse boulders. old colluvial deposits (ca) cover the marine deposit (see paragr. 4.1.1.). l. carobene, a. cervasco & m. firpo solamente nella parte bassa, per alcuni metri, in quanto l’accumulo appare oggi completamente ricoperto da vegetazione. si presenta costituito da alternanze irregolari (fig. 6), ma comunque ben definibili, di limi poveri di detrito, con livelli detritici a clasti spigolosi in matrice limosa. nei primi i diametri della componente detritica sono inferiori a 5 mm; nei secondi il diametro dei clasti oscilla in prevalenza tra 1 e 10 cm, ma alcuni livelli presentano granulometrie inferiori (diametri minori di 5 cm), altri invece granulometrie maggiori (diametri fino a 12 cm circa). alla base del deposito sono presenti isolati clasti spigolosi grossolani, con diametri fino a 20-40 cm. i livelli prevalentemente limosi hanno spessori variabili tra 5 e 10 cm; quelli prevalentemente detritici hanno valori tra 10 e 20 cm. la loro inclinazione è mediamente di 10°. la caratteristica struttura del deposito è dovuta all’alternanza di fasi di sedimentazione causate da prevalente dilavamento del versante, con fasi di trasporto in massa, originato da colamenti per soliflusso oppure da vere e proprie colate detritiche (debris flow). il deposito si presenta pedogenizzato, con colori munsell misurati di 5 yr – 3/4 e di 7,5 yr – 3/4. il deposito sopra descritto passa in alto a un sedimento eterometrico, privo di evidenti strutture, poco coerente, con sparsi clasti centimetrici spigolosi che, nella parte bassa, raggiungono diametri di 10-15 cm. esso presenta un grado di pedogenesi inferiore al precedente (colore munsell 10 yr – 3/4). la stratigrafia dei depositi marini e continentali è riassunta in fig. 7. 171 fig. 6 aspetto del deposito colluviale antico (ca) che ricopre le ghiaie marine (dm) nella sezione s1 (v. tav. i). il colluvium (v. paragr. 4.1.1.) è caratterizzato da alternanze di strati ricchi di clasti spigolosi con strati più sottili prevalentemente fangosi (v. figg. 6 e 7). view of the old colluvial deposit (ca) that covers the marine gravels (dm) in section s1 (see plate). the colluvium (see paragr. 4.1.1.) is characterized by the alternation of layers rich in angular pebbles and thinner layers with predominant muddy texture (see figg. 6 and 7). fig. 7 colonna stratigrafica ricavata dai depositi conservati nella parte interna della piattaforma marina s1 (vedi profilo in tav. i e paragr. 4.1.1). dm= deposito marino a ciottoli arrotondati, con clasti aventi diametro prevalente di 5 cm; in basso sono presenti alcuni massi con diametri fino a 50-100 cm e oltre; in alto diametri fino a 10-15 cm. ca = deposito colluviale antico caratterizzato da alternanze di clasti spigolosi fino a 2040 cm in matrice costituita da clasti di 1-2 cm e da pelite (vedi fig. 6). cr = colluvium rimaneggiato, poco coerente, con clasti spigolosi aventi diametri massimi di 10-15 cm. p = substrato costituito da peridotiti nero-bluastre molto fratturate. sm = superficie di erosione marina lisciata dal moto ondoso. stratigraphic column derived from the deposits preserved in the inner part of the wave cut platform s1 (see profile in plate and paragr. 4.1.1.). dm = marine deposit consisting of rounded pebbles (generally the diameter of the pebbles is about 5 cm); at the base of the sequence some boulders with diameters up to 50-100 cm or more are visible while, at the top, the diameters are smaller (up to 10-15 cm). ca = old colluvial deposit, characterized by alternation of angular pebbles up to 20-40 cm in a matrix consisting of fine pebbles (1-2 cm) and pelites (see fig 6). cr = reworked incoherent colluvium constituted by angular pebbles with diameters up to 10-15 cm. p = bedrock consisting of very fractured blue-blackish peridotite. sm = marine erosion surface, smoothed by wave action. aspetti dell’evoluzione quaternaria della costa ... considerazioni sul paleolivello marino il terrazzo marino descritto è indicativo di una risalita eustatica che ha dato origine ad un alto stazionamento del mare ad una quota non inferiore a 7, 20 m (quota del margine interno della piattaforma d’erosione). la facies del deposito marino non è tipica di un corpo di battigia, ma di un basso fondale ciottoloso, soggetto al moto ondoso. si può pertanto ritenere che il livello di stazionamento sia stato superiore alla quota di 7,20 m. i depositi continentali sopra descritti si sono originati durante il successivo abbassamento eustatico, in relazione a raffreddamento e piovosità e ad una drastica diminuzione della copertura vegetale sui versanti. 4.1.2. sezione s2 (tav. i) il profilo è stato misurato in sinistra del rio partigliolo, in direzione no-se, alla base di un ripido versante sottostante alla s.s. aurelia. il substrato peridotitico si presenta interessato da numerosi sistemi di fratture, tra cui prevalenti: dir. 100°-120°, incl. 60° (imm. so); dir. 30°, incl. 60° (imm. se) (ben visibili nel profilo, inclinate verso mare). sono state misurate inoltre fratture e faglie con dir. 130°, incl. 65° (imm. ne) e fratture circa parallele al profilo, con dir. 140° (imm. so) e 140° (imm. ne). ciò ha favorito l’erosione e la superficie si presenta perciò molto tormentata e irregolare; sedimenti sono conservati solamente nella sua parte più alta. aspetti della piattaforma di abrasione l’ampiezza è di poco superiore a 40 metri; l’andamento altimetrico del profilo è complesso: un tratto intermedio si sviluppa tra 10 m (orlo esterno) e circa 10,50 m s.l.m. (margine interno), per quasi 8 metri, privo di depositi e molto eroso e degradato. il tratto a monte, ampio circa 12 m, si sviluppa ad una quota leggermente più alta, da 11,60 a 12 m circa; esso appare troncato dalla trincea della linea ferroviaria. in corrispondenza del deposito marino la superficie della piattaforma appare ben lisciata e regolare. la presenza di grandi massi, per lo più spigolosi, testimonia che questo tratto era il piede della falesia. le irregolarità del fondale hanno originato sacche riempite di ciottoli arrotondati. la parte verso mare del profilo è interessata da evidenti fratture che interrompono la continuità della piattaforma, originando il relitto a 6,80 m e quello con quota massima di 5 metri. depositi sono presenti solamente nella parte più alta della piattaforma, tra 10,40 e 13,30 m s.l.m. a) il deposito marino il deposito marino si è preservato all’interno di leggere depressioni della piattaforma; è costituito da ciottoli la cui dimensione prevalente è di 10 15 cm, quella massima di 20 30 cm. la matrice, priva di sabbia, è costituita da ghiaia con diametri di 2 5 cm. la forma dei clasti è in prevalenza ellissoidica o appiattita; l’arrotondamento è buono o molto buono. in parte mescolati all’interno del deposito ciottoloso marino, in parte sovrastanti, sono presenti grandi massi di crollo aventi asse maggiore fino a 1 2 m, massimo 2,70 m. il deposito marino, che qui non è ricoperto da colluvium, mostra un intenso color ocra – rosso. considerazioni sui paleolivelli marini la parte esterna della piattaforma, estesa tra 10 e 10,50 m s.l.m., appare distinta dalla parte interna, estesa tra 11,60 e 12,50 m s.l.m., da uno scalino di circa 1 metro, non così elevato tuttavia da permettere una sicura distinzione in due paleolivelli. il relitto di piattaforma a 7 m, per quanto ridotto, è nettamente distinto dal livello superiore prima citato; pertanto può essere considerato la testimonianza del paleolivello a 7,20÷8 metri, ben evidenziato nei profili s1, s3 e s4. il relitto molto degradato a 5 m, potrebbe testimoniare un livello ancora più basso. questa sezione, pertanto, ha fornito un elemento di novità non presente negli altri profili; la sicura presenza di un livello più alto di quello deducibile dai profili s1, s3 e s4. 4.1.3. sezione s3 (tav. i) la sezione è stata effettuata nel tratto di costa tra il rio corvo ed il rio sant’ambrogio, in corrispondenza di un piccolo promontorio roccioso. il settore in esame è caratterizzato da un evidente sistema di fratture, probabilmente faglie, in dir. 170-175° (circa parallele alla direzione del promontorio); fitti sistemi di fratture sono inoltre stati misurati con giaciture: dir. 175°, incl. 70° (imm. e); dir. 5°, incl. 65° (imm. o). sono inoltre state misurate fratture trasversali: dir. 50°, incl. 60° (imm. se); dir. 70°, incl. 55° (imm. sse) e dir. 95°, incl. 80° (imm. s). oltre alle misure di campagna, le foto aeree hanno permesso di ricavare fratture in dir. 140 e 165°. nella sezione immergono verso mare le fratture a 50° e 7095°; verso terra quelle in direzione 140-165°. la roccia del substrato è costituita da metagabbri, a volte con foliazione immergente ad e o ne. un centinaio di metri più ad est, in corrispondenza della baia del corvo, il substrato cambia e affiorano peridotiti più o meno scistose. localmente la roccia si presenta milonitizzata e biancastra. la direzione del profilo è circa n-s, condizionata da uno dei sistemi di frattura a 170-185°. aspetti della piattaforma di abrasione lo stretta prominenza rocciosa, che inizia dalla vecchia linea ferroviaria, si protende in mare per quasi 40 m; su di essa sono conservati i resti di una piattaforma di erosione tra 6,50 m (orlo esterno) e 8 m (margine interno), estesa per circa 25 m. nella parte verso mare (circa 17 metri) la piattaforma si presenta priva di sedimenti e molto erosa e frastagliata; l’erosione è stata favorita dai fitti sistemi di frattura menzionati. la parte verso terra presenta, invece, una superficie (per circa 8 m) nettamente lisciata dall’azione del mare e ricoperta da lembi relitti di deposito marino e dal sovrastante deposito colluviale. il taglio ferroviario ha interessato la parte bassa del versante roccioso, del quale rimane traccia nel profilo, da 7 a 10,5 metri. la parte più esterna della piattaforma presenta un netto scalino di circa 2 m, che divide la parte alta della superficie da un relitto più basso, esteso per circa 3 m, con quota massima di 4,70 m. la correlazione con altri profili effettuati lungo la costa permette di considerare anche questo relitto come testimonianza di una piattaforma marina (vedi ad es. sezione s2). i depositi il lembo dell’originario deposito di spiaggia si estende per 6-7 m, protetto dalla copertura offerta dal sovrastante deposito di piede di versante. 172 l. carobene, a. cervasco & m. firpo a) il deposito marino il sedimento osservabile è costituito da ciottoli decimetrici arrotondati, sui quali poggiano clasti appiattiti immergenti verso mare, monogenici, con il diametro maggiore di 5-15 cm, passanti rapidamente in alto a clasti di minori dimensioni. lo spessore complessivo non sembra superare il mezzo metro. il deposito è clasto-sostenuto, ma l’originaria porosità è stata riempita da limi colluviali di infiltrazione successiva. b) deposito continentale ricopre parzialmente, come sopra accennato, il deposito marino. nel breve tratto di versante tra la ferrovia ed il margine interno della piattaforma marina, il deposito poggia direttamente sulla roccia del substrato per uno spessore di circa 1 m. risulta costituito da un colluvium limoso a clasti millimetrici, e da orizzonti irregolari di clasti spigolosi in matrice limosa. il deposito si presenta pedogenizzato, con colore munsell 7,5 4/6. l’intero lembo dei depositi, sia marini che continentali, è ricoperto da vegetazione. considerazioni sul paleolivello marino per quanto l’affioramento descritto sia limitato, la nettissima embriciatura dei ciottoli indica un deposito di battigia; al paleolivello di stazionamento si può pertanto attribuire una quota simile, ovvero circa 8 m s.l.m. ad esso è attribuibile il relitto di piattaforma esteso tra 6,60 m e 8 m. il piccolo relitto di superficie (con quota massima a 4,70 m) citato precedentemente nella descrizione del profilo, potrebbe essere invece riferito ad uno stazionamento marino alla quota di circa 5 m. 4.1.4. sezione s4 (tav. i) la sezione è stata effettuata in destra del rio corvo, in un punto in cui la fascia rocciosa, non più ampia di 40-45 m, è con grande evidenza condizionata dal sistema di fratture con direzione 24-29° e dal sistema a 118-128° ad esso trasversale, ben riconoscibili dalle foto aeree; nella sezione queste fratture hanno immersione verso terra. sul terreno è stato misurato un sistema di fratture con dir. 35-40°, incl. 65° (imm. no); un altro sistema misurato è in dir. 95°, incl. 80-85° (imm. n). entrambi i sistemi appaiono molto netti. le rocce affioranti in quest’area sono i gabbri a grossi cristalli, localmente interessati da evidente scistosità, con superfici poste circa nne-sso e immersione verso mare. la direzione del profilo effettuato è 135-140°. aspetti della piattaforma d’abrasione il profilo rappresentato nella sezione s4 di tav. i mostra nella parte più esterna un relitto di piattaforma estesa circa 15 m, ampiamente rimodellata dal mare attuale, la cui superficie non sembra superare 1 m di quota (non è stata effettuata una misura diretta). separata da una falesia di circa 6 m, si estende verso riva un secondo relitto di piattaforma, ampio circa 12 m, compreso tra un orlo esterno a 6,50 m e un margine interno a 7,70 m s.l.m. la parte verso mare è priva di sedimenti e la sua superficie superiore si presenta erosa e accidentata; la parte verso terra, invece, è protetta da un lembo di sedimenti in parte marini ed in parte continentali. essi ricoprono una superficie regolare e liscia di origine marina, che termina in corrispondenza di un relitto di paleofalesia che va a raccordarsi con il versante al di là della vecchia ferrovia; la superficie del versante ha una inclinazione di 35°. poco significativo il breve relitto a +3,95 m; esso, tuttavia, potrebbe essere una testimonianza della piattaforma a +5 m circa (vedi anche sezioni s2 ed s3). i depositi marini e continentali sulla superficie interna della piattaforma più alta poggiano ciottoli di forma sia sferoidale che appiattita, ben arrotondati, con dimensioni variabili da pochi centimetri a qualche decimetro. i ciottoli appiattiti sono embriciati verso mare. il deposito marino ha uno spessore inferiore a 0,5 m. esso è direttamente ricoperto da grossi blocchi spigolosi franati e da un lembo relitto di deposito colluviale pedogenizzato, avente spessore di circa 2 m. considerazioni sui paleolivelli marini il relitto esterno, con superficie a circa 1 m s.l.m., può essere ritenuto la testimonianza di una piattaforma marina, confermata dalla presenza di un solco di abrasione, visibile lateralmente al promontorio, avente il punto di massima rientranza a circa 1-1,5 m s.l.m. il relitto della piattaforma superiore, con il lembo di depositi marini che non supera gli 8 metri sul livello del mare, può testimoniare un antico stazionamento ad una quota equivalente. 4.2. punti di descrizione di forme e depositi lungo la costa rocciosa i 4 profili descritti documentano in maniera esemplificativa le forme e i depositi prodotti dagli stazionamenti eustatici lungo il tratto costiero roccioso a valle dell’antica ferrovia. lungo il percorso, tuttavia, sono presenti numerose altre testimonianze che confermano o completano le descrizioni sopra effettuate. i punti di osservazione, numerati progressivamente da cogoleto a varazze (p1-p17 in tav. i), documentano 4 differenti caratteristiche: a) bassi stazionamenti eustatici al punto 8 è presente un piccolo promontorio in serpentiniti che, da 7-8 m di quota, si abbassa rapidamente verso mare dando origine ad una piattaforma molto degradata a 2-4 m s.l.m., per un’ampiezza di 2040 m. sul lato occidentale del promontorio su cui è stata misurata la sezione s4, è presente una stretta piattaforma che si raccorda ad un solco di abrasione marina con massima rientranza a circa 1,5 m s.l.m. b) livello marino a 7-8 metri relitti sono presenti nell’ampio promontorio di punta d’invrea (punto 4); lungo il tratto di costa a so del rio dei pescatori (punti 5 e 6). nel primo è conservato un lembo del detrito di falda che ricopriva il margine interno della piattaforma; nel secondo sono presenti ciottoli arrotondati. al punto 7 si osservano relitti degradati a 7-8 m, con lembi di copertura continentale; al p11 e p12 ciottoli e massi arrotondati sono conservati a 7,5-8 m, al margine interno di 3 piccoli promontori. un altro relitto è presente al p15 a circa 7 m, mentre al p16 il top del relitto è a circa 8 m. infine, a punta della mola (p17), un relitto della piattaforma è stato misurato a 7-8 m s.l.m. (fig. 8). c) livello marino a 11-12 metri l’alto livello di stazionamento riconosciuto dall’analisi della sezione s2 trova parziali conferme in altri punti della costa. sul versante sinistro dell’insenatura pim1 (punto p1) è visibile tra 10 e 12 m circa s.l.m. un 173aspetti dell’evoluzione quaternaria della costa ... relitto di superficie di abrasione sulla quale poggiano abbondanti ciottoli arrotondati con diametro prevalente di 2-5 cm. lo “spuntone” roccioso immediatamente a valle della vecchia ferrovia conserva a 11,4 m s.l.m. ciottoli centimetrici ben arrotondati, spesso appiattiti (fig. 9). un relitto della piattaforma a +12 m è conservato al p3; un altro è visibile al p14, dove la superficie è lisciata e arrossata. infine, alla punta della mola una costruzione, chiamata “villa araba”, è fondata su un ripiano a 12 m s.l.m. (fig. 8). d) testimonianze di massi arrotondati isolati un aspetto particolare dell’area esaminata è costituito da massi arrotondati, con diametri che raggiungono o superano il metro, presenti nella parte interna (più alta) delle piattaforme. sono visibili al p6, a circa 8 m di quota, poggianti su ciottoletti arrotondati e appiattiti; al p10 i massi, il cui diametro supera il metro, poggiano sulla superficie a 9,25 m s.l.m. massi arrotondati sono inoltre osservabili al p11 (fig. 10) e al p14 (a +11,5 m). sul piccolo promontorio corrispondente al p16 i massi poggiano sulla superficie a circa 8 metri. l’origine dei massi può essere il “riciclaggio”, come sembrano testimoniare gli aspetti visibili ai punti 9 e 13. nel primo caso i massi sono incastrati nell’asse del rio corvo, e sono visibili dal ponticello che l’attraversa lungo il lungomare europa. nel secondo caso i massi sono incuneati in una stretta incisione, a monte dell’antica ferrovia, dove il versante che si raccorda all’orlo esterno del terrazzo del 1° ordine ha un’inclinazione di 31°. i massi sono stati segnalati più volte sul terrazzo del 1° ordine (carobene & firpo, 2002). i l fenomeno del riciclaggio è stato ampiamente dimostrato per i terrazzi marini in destra trionto, nella calabria ionica (carobene, 2003). 4.3. descrizione delle paleoinsenature marine lungo il tracciato del lungomare europa sono state osservate numerose rientranze del versante costiero interpretate, per le loro caratteristiche, come “paleoinsenature” di origine marina (pim in tav. i). esse presentano le seguenti caratteristiche: 1) 7 insenature su 8 sono fronteggiate da una spiaggia ghiaioso-sabbiosa. in questi casi la striscia rocciosa a valle della vecchia linea ferroviaria è assente. 2) in 4 casi su 8 l’insenatura coincide con lo sbocco a mare di un corso d’acqua (insenature n. 1, 3, 4 e 6). nei 4 casi in cui il corso d’acqua è assente, l’insenatura ha dimensioni più ridotte. 3) le rientranze presentano versanti più ripidi del 174 fig. 8 parte iniziale, verso varazze, del “lungomare europa” (punta della mola punto 17 in tav. i). la villa poggia su roccia a 10-12 m s.l.m., probabilmente in corrispondenza del margine interno di una superficie di abrasione marina, testimoniata dal relitto a +8,3 m (foto scattata da ne verso so). beginning of the "europe promenade”, close to varazze (punta della mola point 17 in plate). the house (villa araba) was built on the bedrock at 10-12 m a.s.l., probably at the inner margin of a marine abrasion surface which is testified by a relic at +8.3 m (the photo was taken from ne to sw). fig. 9 a destra relitto di una piattaforma a 10-11 m s.l.m. (il piano stradale è a circa 7,5 m). a sinistra l’ingresso di una delle 7 gallerie che si aprono lungo il percorso del “lungomare europa”. on the right a relic of a platform at 10-11 m a.s.l. (the road is about at 7.5 m in elevation). on the left the entrance of one of the 7 galleries found along the “europe promenade”. l. carobene, a. cervasco & m. firpo estesa attualmente per circa 7 m all’esterno della grotta e troncata verso mare dalla falesia attuale; il relitto di tale piattaforma risale debolmente verso l’interno della grotta, da 8,70 m a 9,25 m. sulla piattaforma, al disotto di un pavimento in cemento e mattonelle, si ritrovano sabbie e ciottoli arrotondati (fig. 14). le onde, risalendo sulla piattaforma, hanno allargato progressivamente (durante l’alto stazionamento) la zona di fratturazione sopra citata, originando pareti dalla caratteristica forma parabolica visibile sia nel profilo trasversale (fig. 15) sia nel profilo longitudinale (fig. 16). l’incavo alla base delle pareti viene qui denominato, per la sua forma ed origine, “solco parietale di abrasione marina” (fig. 15 e fig. 13). le condizioni morfologiche del fondale antistante hanno provocato (così come provocano ancora oggi in condizioni analoghe) un considerevole innalzamento del mare, che può facilmente aver superato i 2 m. poiché il punto di massima rientranza sul fondo della grotta è stato misurato a + 9,73 m (fig. 16), è lecito supporre che il livello medio del mare (durante i periodi di calma) fosse decisamente più basso. le considerazioni sopra esposte permettono di attribuire la genesi della grotta allo stazionamento marino a 7,5÷8 m s.l.m. riconosciuto nelle sezioni esposte al paragr. 4.1. 5. rapporti tra morfologia e tettonica 5.1. il sollevamento l’area ha subito un sollevamento plio-quaternario, già discusso da carobene & firpo (2002) per il settore costiero savona-genova. tenendo conto sia della quota dei terrazzi marini presenti, sia dell’età, della batimetria (negri et al., 1997) e delle quote delle argil le del pliocene inferiore affiorante (rovereto, 1934), carobene & firpo (2002) hanno ipotizzato un primo sollevamento pliocenico relativamente veloce (tasso medio vicino a 0,2 mm/a), che avrebbe portato (nell’arco di 2 milioni di anni) le argille plioceniche (con batimetria presunta di 400 metri) a livello del mare. a questo avrebbe fatto seguito un sollevamento quaternario più lento, che ha portato dette argille (non affioranti nell’area di studio ma nei settori limitrofi) a circa 100 m di quota. ciò comporta un tasso medio di sollevamento 4 volte minore. il calcolo presenta vari punti d’incertezza legati alla valutazione precisa della batimetria delle argille, alla loro reale quota d’affioramento, alla effettiva data d’inizio del sollevamento. ad ogni modo è difficile ipotizzare, per tutto il periodo plioquaternario, un tasso medio di sollevamento prossimo o superiore a 0,2 mm/a, perché in questo caso le argille del pliocene inferiore si troverebbero a 400 m sul livello del mare. ciò si verifica in liguria solamente lungo la 176 fig. 12 ingresso della grotta mizar scavata dal mare in corrispondenza di una frattura (dir. 205°, imm. ese, incl. 65° vedi fig. 13). la roccia è una peridotite serpentinizzata. all’interno, sotto al pavimento con mattonelle, è ancora presente il deposito marino (v. fig. 14). the “mizar cave” entrance. the sea cave was carved in correspondence of a fracture (strike 205°, dip 65°, dip direction ese see fig. 13) affecting the serpentinized peridotite. inside, beneath the tile floor, there is the marine deposit (see fig. 14). fig. 13 profilo trasversale eseguito all’ingresso della grotta mizar. esso mette in evidenza i principali caratteri morfologici, in particolare il “solco parietale di abrasione marina” (sa) e la volta (v). transverse profile of the “mizar cave” entrance. the main morphological characters are shown, in particular: the “marine abrasion parietal notch” (sa) and the roof of the cave (v), the rocky bottom of the cave (fg) covered both by sediments and artificial floor (pa). the cave is developed along the fracture zone (zf) affecting the peridotite (p). l. carobene, a. cervasco & m. firpo costa di ponente, dove il settore più sollevato appare quello compreso tra il confine di stato (m. bellenda, 541 m) e taggia (punta pistorin, 486 m), mentre tra taggia e genova il pliocene si ritrova generalmente sotto la quota di 100 m (rovereto, 1934; boni & peloso, 1973; marini, 2001). e’ lecito ritenere, pertanto, che nel quaternario il tasso medio di sollevamento sia stato minore di 0,1 mm/a come ipotizzato da carobene & firpo (2002), in base alle quote del pliocene affiorante e ai suoi rapporti con il terrazzo del 1° ordine (vedi anche carobene, 2004). poichè la quota del tirreniano (mis 5.5) nella liguria di ponente non supera mai gli 8 m, e solamente ai balzi rossi (confine di stato) è di qualche metro più alto, il corrispondente tasso di sollevamento non supera 0,03 mm/a e, come conseguenza, la velocità di sollevamento iniziale è andata progressivamente diminuendo nel quaternario. i due ordini di terrazzi (rappresentati in tav. i) con margini interni alle quote di 70÷115 m e di 65÷70 m, e con copertura sedimentaria marina e superfici terrazzate ancora abbastanza ben conservate, sono pertanto attribuibili, rispettivamente, al pleistocene inferiore finale e al pleistocene medio iniziale. il lento sollevamento subito successivamente dal settore costiero (valore medio minore di 0,1 mm/a) non ha favorito la conservazione delle linee di riva che progressivamente si formavano nel tempo. solamente alla quota di 7,5-8 m circa (margine interno della piattaforma marina) è ben riconoscibile la linea di riva più bassa e più recente; essa è attribuibile perciò al tirreniano, per analogia con le ricerche svolte a voltri-palmaro, circa 12 km a ne dell’area studiata (carobene & firpo, 1994). la morfologia del settore costiero esaminato è, quindi, fortemente condizionata dall’entità del sollevamento sopra menzionato; esso ha dato origine alla rete idrografica oggi visibile ma, contemporaneamente, lo spostamento nel tempo della linea di riva verso mare è stato molto minore di quanto sia accaduto nelle aree a forte sollevamento. carobene (2003) ha proposto il calcolo dell’angolo derivante dal rapporto “sollevamento quota terrazzo/distanza dalla linea di riva” quale indicatore di questo fenomeno. i terrazzi calabresi della costa ionica (zona del trionto – rossano), soggetti ad un sollevamento medio di 0,56 mm/a (bigazzi & carobene, 2005), hanno fornito valori di detto rapporto compresi tra 2,1° e 3°. il terrazzo alto dell’area studiata nel presente lavoro (margine interno di quota circa 100 m) e distanza media da riva di circa 400 m, fornisce invece un valore di ben 14°. tale differenza è determinata dal maggior tasso di sollevamento della costa ionica, che si traduce in una miglior conservazione del versante e dei terrazzi che si sono sollevati nel tempo. un fattore che può 177 fig. 14 deposito affiorato da uno scavo effettuato nel pavimento, nella parte interna della grotta. la foto mostra ciottoli ben arrotondati, spesso appiattiti, con diametri prevalenti di 510 cm. i ciottoli sono immersi in sabbia pedogenizzata. deposit excavated beneath the cave floor. the photo shows well rounded pebbles, often flattened, with prevalent diameters of 5-10 cm. the pebbles are embedded in sand with pedogenesis evidence. fig. 15 aspetto della parete di no della grotta mizar (v. fig. 13), caratterizzato da una regolare rientranza denominata “solco parietale di abrasione marina”. il “punto di massima rientranza” del solco si abbassa verso l’esterno, da 9,73 a 9,50 m circa (inclinazione di circa 2-2,5°). nw side of the “mizar cave” (see fig. 13), characterized by a smooth curved surface called "marine abrasion parietal notch”. the "point of maximum retreat” of the notch lower itself to the outside, from 9.73 m to 9.50 m in height (dip angle about 22.5°). aspetti dell’evoluzione quaternaria della costa ... condizionare tale rapporto è costituito, ovviamente, dalla litologia del substrato. 5.2. sistemi di fratturazione e di faglie le fratture sono state misurate solamente lungo la stretta fascia rocciosa costiera (la larghezza è generalmente inferiore a 50 m) compresa tra il tracciato della vecchia ferrovia e la linea di riva attuale; qui la roccia è affiorante tra circa 10 m ed il livello mare. le fratture presentano spaziatura centimetrica o decimetrica ed inclinazioni prevalenti fra 60° e 80°. circa 2/3 delle misurazioni sono state fatte direttamente sul terreno, mentre i restanti valori sono stati ricavati dall’analisi delle foto aeree, sia in bianco e nero (volo del 31/7/95), sia a colori (volo del giugno-settembre 1974). su un diagramma circolare, suddiviso in settori da 10°, sono stati riportati 111 valori di direzione; ciò ha permesso di ricavare il diagramma a rose della fig. 17. sono riconoscibili 5 raggruppamenti principali (i valori sono sempre misurati in senso orario a partire da nord): 1) 351°-10°: valore centrale della classe modale 355°; valore medio 3° 2) 11°-30°: valore centrale della classe modale 25°,valore medio 21° 3) 51°-70°: valore centrale della classe modale 60°,valore medio 62° 4) 81°-110°: valore centrale della classe modale 95°, valore medio 97° 5) 121°-140°: valore centrale della classe modale 135°, valore medio 131° una conferma di questi sistemi, ricavati a scala locale, viene da un’analisi dei principali lineamenti effettuata su una vasta area dell’entroterra tra albissola e cogoleto, raggruppabili in 3 classi molto nette: 1) 20°25°; 2) 50°-60°; 3) 125°-140°, perfettamente coerenti con i raggruppamenti di fratture 2, 3 e 5 sopra riportati. una parte dei lineamenti studiati, ricavati dallo studio della morfologia e dell’idrografia dell’area, è riportata in fig.1, dove compaiono 3 gruppi principali: 1) 21°-23°; 2) 55°-60°; 3) 125°136°. le rocce affioranti, metagabbri e peridotiti serpentinizzate, hanno quindi avuto un comportamento fragile durante le fasi di sollevamento plio-quaternario. ciò ha determinato faglie subverticali e sistemi di fratture che hanno giocato un ruolo determinante sull’evoluzione morfologica quaternaria del paesaggio: indizi di questa influenza si ricavano dall’andamento dei crinali e dei versanti, dalla direzione dei corsi d’acqua e della linea di costa.e’ interessante notare, infine, che le direzioni dei principali raggruppamenti modali individuati nel corso di questo studio coincidono con le direzioni delle strutture fragili, riportate in marini (1987), che interessano gli affioramenti pliocenici di lerca-sciarborasca. in particolare, secondo l’autore, i piani con direzione n-s ed e-o, corrispondenti a quelli delle classi 1) e 4) sopra evidenziate, costituiscono, rispettivamente, i piani di taglio principali ed ausiliari delle deformazioni fragili che, a partire dal pliocene inferiore, avrebbero controllato la sedimentazione dei depositi pliocenici. 5.3. il frazionamento e la dislocazione del terrazzo del 1° ordine il terrazzo alto presenta tra il rio mola a so e il t. 178 fig. 16 sezione longitudinale della grotta mizar. la piattaforma di abrasione presegue anche all’esterno della grotta per 7 metri (con inclinazione di 2,5-3° circa) ed è troncata dalla falesia attuale. il sedimento marino messo in evidenza dallo scavo è visibile in fig. 14. longitudinal section of the “mizar cave”. the roof profile (v) has a very regular shape. the abrasion platform (pa) continues for 7 m outside the cave and it is cut by the cliff. the marine sediment (sm) pointed out by the excavation (s) is visible in fig. 14. symbols: pa = artificial floor; f = cliff. fig. 17 diagramma a rosetta relativo alla direzione delle fratture misurate lungo la costa rocciosa (fc2 in tav. i). rose diagram of the fracture’s strike measured along the rocky coast (fc2 in plate). l. carobene, a. cervasco & m. firpo arrestra a ne un margine interno variabile da 95 m a 105 m s.l.m.; subito ad ovest del rio mola la quota scende a 70÷80 m, e subito ad est del t. arrestra essa si porta a 115 m (tav. i). la deformazione legata al sollevamento dell’area ha pertanto prodotto una dislocazione altimetrica del terrazzo. ciò è coerente con il comportamento di tutto il settore costiero savonagenova; esso può essere considerato il risultato di un basculamento oppure, con maggior probabilità, la conseguenza di faglie attive nel pleistocene. di particolare importanza la “faglia del teiro”, visibile solo parzialmente a so (fig. 1) con direzione 133° e la “faglia dell’arrestra” a ne, con uguale direzione. dislocazioni minori, tra cui quella corrispondente al rio vignetta (direz. 136°), quella del rio donne (direz. 136°) e quella del rio pescatori (direz. 129°), si osservano tra il teiro e l’arrestra; esse hanno provocato lo smembramento dell’originario terrazzo in distinte superfici terrazzate (tav. i). 5.4. il controllo delle faglie su: corsi d’acqua, cale lungo costa e direzione dei tratti costieri come sopra evidenziato, molti corsi d’acqua hanno tratti rettilinei o un andamento del corso rettilineo, con direzioni trasversali alla costa comprese tra 130° e 140°, oblique alla costa comprese tra 21° e 23° e longitudinali alla costa a 55°-60°. ciò provoca anche vistosi gomiti fluviali, come quelli del t. arrestra e del rio partigliolo; particolarmente condizionato appare il percorso del rio ciusa (fig.1). l’incrocio di uno o più sistemi con la linea di costa coincide con le piccole cale presenti lungo la passeggiata europa (vedi tav. i), in quanto la fratturazione della roccia ha evidentemente favorito il processo erosivo marino. la linea di costa nel settore ab (tav. i) ha una direzione di 21°, corrispondente al sistema di faglie 21°23°, ben rappresentato in fig. 1; essa corrisponde perfettamente, sia come direzione sia come allineamento, alla direzione di ampi tratti rettilinei del rio lerone (che sfocia a ne di cogoleto fuori tavola). il tratto di costa del settore bc ha direzione 56°, anch’essa appartenente al sistema di faglie già segnalate (paragr. 5.2). analoga direzione (57°) ha la tangente tra punta della mola (in fig. 1), punta dell’olmo e punta celle (fuori tavola). carobene & firpo (2002) avevano già evidenziato come tutto il tratto di costa tra savona e genova-voltri abbia un andamento rettilineo a 58°, che testimonia un netto legame con l’evoluzione recente del margine continentale. inoltre, l’andamento del margine interno del terrazzo del 1° ordine (quota 95 m) (che è una vecchia linea di costa) ha una direzione di 64° (tra punta della mola e punta dei pescatori tav. i), valore che si discosta di poco da quello dell’andamento costiero attuale (circa 61°). la tangente (nell’analogo tratto) agli orli esterni del terrazzo del 1° ordine ha una direzione di 63°. la direzione della linea di costa attuale tra il t. arrestra e il rio partigliolo, con direzione 21° (settore ab), si discosta invece dall’antica linea di riva della corrispondente superficie terrazzata alta (margine interno con direzione 48°). il relitto terrazzato in sinistra del t. arrestra ha invece una direzione del margine interno (28°) che si approssima notevolmente a quella del tratto di costa ab. questi dati forniscono indicazioni originali sulle direzioni della linea di costa nel pleistocene inferiore. 6. conclusioni dal lavoro effettuato si ricava: 1) che la “ricostruzione storica” degli eventi è possibile se forme e depositi vengono studiati in dettaglio in modo da trovarne le reciproche relazioni; 2) che la morfologia di un paesaggio costiero in sollevamento (o che si è sollevato nel quaternario) è “una combinazione tra un insieme di forme marine, create dagli alti stazionamenti eustatici interglaciali, ed un insieme di forme continentali formatesi in gran parte durante i lunghi periodi glaciali”. l’insieme di un tipo si forma sempre a spese dell’altro, per cui oggi il paesaggio costiero è in realtà costituito da una combinazione di “relitti” di genesi e di età diversa. le ricerche condotte hanno portato a precisare i principali aspetti morfologici di un paesaggio che ha iniziato a formarsi e a rimodellarsi nel pliocene medio, evolvendo nel tempo sotto l’azione degli eventi tettonici e dei processi esogeni continentali e marini. i dati raccolti sono stati condensati nella tav. i, dalla quale è possibile cogliere i seguenti aspetti:. il paleopaesaggio pliocenico rimodellato. esso è in parte rappresentato da una serie di culminazioni topografiche, comprese in maggioranza tra 300 m e 400 m di quota, derivate da una originaria superficie di spianamento sollevatasi nel corso del pliocene mediosuperiore quaternario con un tasso medio non superiore a 0,2 mm/a. durante questo lungo periodo l’antica superficie è stata erosa, rimodellata e incisa dallo sviluppo della rete idrografica. il paesaggio quaternario. appare morfologicamente ben distinto da quello pliocenico in quanto caratterizzato dalla presenza dei terrazzi marini al disotto della quota di 180 m. ben rappresentato è il terrazzo del 1° ordine, con margine interno a 70÷115 m, in cui sono ancora ben presenti i depositi marini; considerata tale quota esso è stato riferito al pleistocene inferiore finale (1,2 0,9 milioni di anni). meno esteso, ma comunque rappresentato, è il terrazzo del 2° ordine con margine interno a 65÷70 m. tenendo conto del tasso di sollevamento quaternario, questo ordine è stato attribuito al pleistocene medio iniziale. la fascia rocciosa tra 0 e 12 metri. lungo la costa, a quote inferiori ai 12 m, si sviluppa tra il piede dei versanti e il livello del mare una striscia rocciosa che conserva relitti di superfici marine terrazzate riferibili a due precise paleolinee di riva: a 7,5÷8 m e a 11,5÷12 m s.l.m. depositi marini costituiti da sabbie e ciottoli arrotondati, ricoperti da depositi pedogenizzati di piede di versante, sono conservati in piccoli lembi isolati. il livello a 7,5÷8 m è stato attribuito al tirreniano (mis 5.5), con riferimento agli studi condotti a voltri-palmaro (carobene & firpo, 1994) e alla grotta di bergeggi (issel, 1911). mancano gli elementi per una collocazione temporale della linea di riva più alta. incerto un livello più basso, con relitti compresi tra 4 e 5,50 metri. l’evoluzione plio-quaternaria. gli elementi morfologici sopra citati marcano, con la loro quota e con la loro età, le tappe dell’evoluzione del paesaggio costiero nel pliocene-quaternario. gli aspetti morfologici della fascia costiera portano a concludere che l’area di stu179aspetti dell’evoluzione quaternaria della costa ... dio è il risultato di un moderato sollevamento iniziato nel pliocene medio; essa è separata dalla piattaforma marina antistante da linee tettoniche orientate 56-57° (circa ene-oso) e 21-22° (nne-sso) . durante il sollevamento diversi sistemi di faglie e fratture hanno condizionato, oltre che l’andamento della linea di costa, anche lo sviluppo dell’idrografia e lo smembramento dei terrazzi. il basso tasso di sollevamento quaternario ha favorito l’erosione costiera e il suo arretramento, generando versanti costieri ripidi. lo spostamento verso terra dell’attuale linea di riva, particolarmente evidente nel pleistocene medio e superiore come conseguenza del decrescente tasso di sollevamento, costituisce probabilmente anche la causa della ripidità dei versanti vallivi nella parte finale dei corsi d’acqua. i risultati raggiunti, e sinteticamente sopra esposti, forniscono elementi nuovi e sufficientemente dettagliati per una comprensione del paesaggio dal punto di vista morfologico, genetico e cronologico. riferimenti bibliografici aa.vv. (1996) atlante cartografico geologico del territorio del comune di genova. cartografia geologica, geomorfologica e idrogeologica in scala 1:10.000. comune di genova amga. bigazzi g. & carobene l. (2005) datazione di un livello cineritico del pleistocene medio: relazioni con sedimentazione, sollevamento e terrazzo marini nell'area crosia-calopezzati in calabria (italia). il quaternario italian journal of quaternary sciences 17 (2/1) (2004), 151-163. boni a., cerro a., gianotti r. & vanossi m. (1971) note illustrative della carta geologica d’italia 1:100.000, foglio (92-93) «albenga-savona». serv. geol. it., roma, 142 pp. boni p. & peloso g.f. (1973) i lembi pliocenici della liguria occidentale da terzorio al confine italofrancese. atti ist. geol. univ. pavia, 23, 170-201. bosi c., carobene l. & sposato a. (1996) il ruolo dell’eustatismo nella evoluzione geologica nell’area mediterranea. mem. soc. geol. it., 51, 363-282. c.n.r. (1987) neotectonic map of italy. quaderni della ricerca scientifica, 4, n.114, 6 tavv. 1:500.000. capponi g., gosso g., scambelluri m., siletto g.b. & tallone s. (1994) carta geologico-strutturale del settore centro-meridionale del gruppo di voltri (alpi liguri) e note illustrative. boll. soc. geol. it., 113, 383-394. carobene l. (2003) genesi, età, sollevamento ed erosione dei terrazzi marini di crosia-calopezzati (costa ionica della calabria – italia). il quaternario, 16 (1), 43-90. carobene l. (2004) uplifted coastlines and marine terraces. in: geology of italy, crescenti u., d’offizi s., merlino s., sacchi l. (eds.). special volume of the it. geol. soc., 174-177. carobene l. & firpo m. (1994) una paleospiaggia tra voltri e palmaro (genova): evidenze sedimentologiche e morfologiche. il quaternario, 7 (1), 123138. carobene l. & firpo m. (2002) forme terrazzate relitte di genesi marina lungo la costa ligure tra genova e savona (liguria occidentale). il quaternario 15 (1), 53-68. cortellesi d., fanucci f., giuffrè a., tedeschi d. & vignolo a. (1979) dati preliminari sulla neo-tettonica del foglio 82 genova. nuovi contributi alla realizzazione della carta neotettonica d’italia, c.n.r., pubbl. 251, 579-595. fanucci f. (1979) neotettonica dei margini continentali del mar ligure. mem. soc. geol. it., 19 (1978), 535-542. fanucci f. (1988) évolution stratigraphique de la région du golfe de gênes depuis l’eocène supérieur. mem. soc. geol. it., 36 (1986), 19-30. fanucci f. & nosengo s. (1979) rapporti fra neotettonica e fenomeni morfogenetici del versante marittimo dell’appennino ligure e del margine continentale. boll. soc. geol. it., 96 (1977), 41-51. fanucci f. & tedeschi d. (1983) linee di costa e terrazzi marini del foglio 82 (genova). contr. concl. realizz. carta neotett. italia, 513 (2) (1982), 387396, c.n.r. federico l., capponi g., crispini l., scambelluri m. & villa i.m. (2005) 39ar/40ar dating of high –pressure rocks from ligurian alps: evidence for a continuous subduction-exhumation cycle. earth and planetary science letters, 240, 668-680. hoogerduijn strating e.h. (1990) folding of lithosphere in the piemonte-ligurian ocean. geol. en mijnbouw, 69, 31-41 issel a. (1911) l’evoluzione delle rive marine in liguria. boll. soc. geogr. it., fasc.9-12, 112 pp., roma. marini m. (2001) il pliocene ligure fra ventimiglia e bordighera (imperia, alpi marittime liguri): osservazioni preliminari. boll. soc. geol. it., 120 (2001), 37-46. marini m. (1987) le deformazioni fragili del pliocene ligure. implicazioni nella geodinamica alpina. mem. soc. geol. it., 29 (1984), 157-169. negri a., pirini c., razzore s. & bonci m.c. (1997) micropaleontological record in the pliocene of genoa-arenzano area. boll. soc. paleont. it., 36 (1-2), 261-274. provincia di savona (2007) piano di bacino stralcio sul rischio idrogeologico – caratteristiche idrauliche e geologiche del territorio – valutazione del rischio idraulico e geomorfologico – relazione – ambiti di bacino di rilievo regionale: letimbro, arrestra. bacino: sanda. settore difesa del suolo e tutela ambientale – servizio piani di bacino. regione liguria (1997) carta geologica regionale con elementi di geomorfologia (cgr) sc. 1:25.000 – varazze – tav 229.1. rovereto g. (1934) epirogenesi postpliocenica delle alpi marittime e della riviera ligure rend. acc. naz. lincei, serie 6, 20 (5-6), 153-157, roma. s.g.i. (1991) alpi liguri. guide geologiche regionali, 295 pp., be-ma ed. vanossi m., cortesogno l., galbiati b., messiga b., piccardo g. & vannucci r. (1986) geologia delle alpi liguri: dati, problemi e ipotesi. mem. soc. geol.it., 28 (1984), 5-75. 180 ms. ricevuto il 10 giugno 2010 testo definitivo ricevuto il 21 settembre 2010 ms. received: june 10, 2010 final text received: september 21, 2010 l. carobene, a. cervasco & m. firpo amq sr00 rossato et al 209-228.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 33 (2), 2020, 209-228 learning from the past to face the future: landslides in the piave valley (eastern alps, italy).� sandro rossato1, monica ghirotti2, fabio gabrieli3, franz livio4, francesco bovo3, lorenzo brezzi3, paolo campedel5, simonetta cola3, susan ivy-ochs7, silvana martin6, paolo mozzi6, alessandro pasuto8, manuel rigo1,6, paolo simonini3, nicola surian6, alfio viganò5, christof vockenhuber7, andrea wolter9 � 1 institute of geosciences and earth resources, national research council of italy, padova, italy. 2 department of physics and earth science, university of ferrara, ferrara, italy. 3 department of civil, environmental and architectural engineering, university of padova, padova, italy. 4 dipartimento di scienza ed alta tecnologia, università degli studi dell’insubria, como, italy. 5 servizio geologico, provincia autonoma di trento, trento, italy. 6 department of geosciences, university of padova, padova, italy. 7 department of earth sciences, eth zürich, and laboratory of ion beam physics, eth, zürich, swiss. 8 research institute for geo-hydrological protection, national research council of italy, padova, italy. 9 engineering geology, gns science, avalon, lower hutt, new zealand. corresponding author: s. rossato <sandro.rossato@igg.cnr.it> abstract: landslides are a critical process in landscape evolution and may pose a serious threat to people and infrastructure. in the last decades, a growing interest in such phenomena has developed in the alps, where narrow valleys are increasingly inhabited, and landslides have caused several casualties. understanding the driving factors, triggers, evolution, and impact of past and future failures is of the utmost importance when dealing with land use and risk reduction. in this paper, four distinct case studies are presented, showing how different approaches can interact and produce a comprehensive understanding of a landslide event. all examples lie in the middle sector of the piave valley (ne italy) and deal with failures that occurred in the distant past (i.e., the historic masiere di vedana rock avalanche), in the near past (i.e., the 1963 vajont event), in the present (i.e., the 60-years -lasting tessina landslide) and in the future (i.e., possible mt. peron instabilities). the final goal of the paper is to show how the understanding of past landslides is fundamental to obtain reliable predictions on future failures, and how modelling designed to predict the evolution of potential detachments can be applied to understand the dynamics of ancient events. keywords: field survey, remote sensing, modelling, land management, isotopic dating. � 1. introduction landslides have always been a relevant topic for both researchers and society. they are both a relevant process in landscape evolution and a severe risk to human lives and buildings. due to the potential catastrophic consequences, landslides can be considered one of the most threatening and devastating natural hazards in densely populated mountain regions (crosta et al., 2004; abdulwahid & pradhan, 2017). dilley (2005) estimated that 66 million people live in areas classified as “high-risk”. globally, italy is particularly prone to landslide hazard, having vast mountainous regions and a dense network of populated areas and infrastructures, that nearly tripled in the last 70 years (ispra, 2018). according to the italian landslide inventory (iffi; trigila et al., 2007; http://www.progettoiffi.isprambiente.it/ cartografia-on-line/), which is designed to collect and organize all landslides in italy, more than 600,000 landslides (i.e., about two thirds of all european events; herrera et al., 2018) have occurred in italy, affecting over 23,700 km2, (i.e., 7.9% of the entire nation; trigila et al., 2018). currently, about 1,280,000 people live in areas classified as “very high” and “high” risk (trigila et al., 2018). it is worth noting that the costliest natural disaster in italy in the last 30 years was the 1987 val pola landslide, with an estimated impact of about us$ 400 million (crosta et al., 2004). when facing decision-making processes regarding the land use of their territory, administrations should take into consideration landslide hazard and vulnerability (e.g., abdulwahid & pradhan, 2017), and how these values may vary over time (e.g., massey et al., 2014). locally focused surveys and modelling, combined with https://doi.org/10.26382/amq.2020.14 210 rossato s. et al. the investigation of past events are fundamental in the evaluation of potential failures (samia et al., 2017). identifying the driving factors and possible triggers is also pivotal (e.g., eisbacher & clague, 1984; nicoletti & sorriso-valvo, 1991; hungr, 2006; strom, 2006; hermanns & longva, 2012). several aspects are common in large, catastrophic rockslides. first, a distinctive trigger is not always apparent or necessary. the context of the slope, such as strata folds and faults, geomorphic processes, hydrogeological conditions, and slope morphology may be sufficient to damage the rock slope and bring it to failure (donati et al., 2020). at this stage, any small change in equilibrium may cause catastrophic failure. the second aspect is the structural setting: elements such as faults, folds, and fractures play a significant role in most rock slope failures. sliding surfaces are commonly located on planes of weakness such as bedding and foliation, where water can infiltrate, weathering can take place and failures may occur. seismic events and hydrogeological conditions commonly act in concert with lithological and structural controls to condition slopes for failure (stead & fig. 1 simplified geological map of the alpine sector with the location of the case studies (black circles). the map is based on the structural model of italy (bigi et al., 1990), the belluno geological map (costa et al., 1996), and the paper by zanferrari et al. (2013) and overlies the italian srtm derived digital elevation model (25-m cells). small-scale structural setting (upper-left corner) is based on doglioni (1990). ast: alpine sole thrust; bl: belluno thrust; bs: belluno syncline; ca: cansiglio thrust; cp: coppolo-pelf anticline; cvm: val carpenadaval di vido-val madonuta thrust; dt: monte duranno-tramonti thrust; esa: eastern southern alps thrust system; fpt: frontal penninic thrust; pm: polcenigo-montereale thrust; il: insubric line; vs: valsugana thrust. 211 wolter, 2015). finally, many large rock slopes show some sign of movement prior to collapse, and some slopes continue to slowly deform after failure. this trend agrees with what glastonbury & fell (2010) observed when examining characteristics of large rapid rockslides. they suggested that strength loss along the rupture surface is a key element to the initiation of rapid failures. not all slowly deforming slopes have evolved into rapid landslides, however. in the piave valley, many landslides are reported, and vary remarkably in size, kinematics, and impact. some of them are sadly known to have caused much damage and numerous casualties (rossato et al., 2018) and the vast majority are influenced by the regional stratigraphic and tectonic setting. in the eastern southern alps, the indentation of the adria plate with the alpine orogeny deformed the entire bedrock package, folding, faulting and overthrusting the stratigraphic sequence and creating or reactivating a dense system of tectonic structures (márton et al., 2003; d’agostino et al., 2008). in this paper we aim to compare approaches, data, and possible outcomes deriving from different types of landslide studies. we chose four distinct case studies, dealing with events that occurred in the distant past (i.e., the historic masiere di vedana rock avalanche), in the near past (i.e., the 1963 vajont event), in the present (i.e., the 60-years-lasting tessina landslide) and possibly in the future (i.e., mt. peron instabilities) (fig. 1). each of them will be described, highlighting the investigation methods that have been applied, the impact on the landscape and the population, and remaining open questions. we chose these case studies to highlight how remarkably different landslides can occur in a small area. the examples have been collected in the middle sector of the piave valley and its surroundings, within a maximum distance of ~15 km from belluno, the largest city of the valley. all case studies will show how an integrated approach considering multiple disciplines (e.g., structural geology, engineering geology, geomorphology) and methods (e.g., field survey, remote sensing, dating techniques, numerical modelling) is needed for effective landslide recognition and hazard assessment. the landslides discussed in this paper have been also presented in the framework of the sites visited in trentino/south tyrol during the summer school on “historic and prehistoric landslides in the ne italian alps implications for new hazard maps in mountainous areas”, hosted by the university of padua in 2019. the other sites of the trentino region visited during the summer school are presented in a companion paper in this volume (martin et al., 2020). 2. setting the piave valley is one of the largest valleys in the eastern southern alps. the northern sector of this valley is nne-ssw trending and narrow (the valley bottom is ~1 km wide at longarone), whilst near belluno it becomes wider (~4 km) and turns towards sw (fig. 1). the present shape of the piave valley is mostly due to quaternary glacial activity. during the last glacial phase from the past to the future: landslides in the piave valley fig. 2 stratigraphic sketch of the geological units cropping out in the belluno area, based on costa et al. (1996) and carulli et al. (2000). the portions of the stratigraphic sequence involved in each case study is shown. (30-17.5 ka cal bp; monegato et al., 2017), the piave glacier, sustained also by tributary ice-streams, was up to 1,000 m thick in the study area (pellegrini et al., 2006; carton et al., 2009; pasuto, 2017). at ponte nelle alpi, the piave glacier split into two tongues flowing to the sw and to the s, along the piave valley and the lapisina valley, respectively. the study area belongs to the neogene-present back-thrusted (s-vergent) part of the alpine chain. it is bounded by two of the main tectonic lineaments related to the alpine orogeny: to the north by the valsugana thrust fault and to the south by the s-verging and wswene oriented belluno thrust (doglioni, 1990; galadini et al., 2005). all case studies belong to the hanging wall of this latter tectonic structure (doglioni, 1990), that bounds the northern limb of the belluno syncline. the stratigraphic sequence of the forelimb is deformed to various extents, locally even overturned (doglioni, 1990; costa et al., 1996). since the jurassic, the study area has been characterized by the presence of a basin (belluno basin) bounded by two platforms, one to the east (friulian) and one to the west (trento). the dominant lithologies of the platforms are triassic limestones and dolomites. in the belluno basin, the jurassic and cretaceous limestones and marls are conformably overlain by eocene turbidites, which are in turn unconformably covered by oligomiocene sandstones and clays (venzo, 1939; stefani et al., 2007) (fig. 2). south of ponte nelle alpi, the piave valley separates the alps from the venetian prealps, representing the forelimb of the alpine chain, mainly made of mesozoic and tertiary sedimentary rocks (costa et al., 1996). due to the lateral variability of the geological units, as well as the presence of minor tectonic features and peculiar deformations, each case study will include 212 more site-specific information. 3. the masiere di vedana rock avalanche (mv) 3.1. historical background the masiere di vedana (abele, 1974; eisbacher & clague, 1984; pellegrini et al., 2006), also known as “rovine di vedana” (mazzuoli, 1875, squinabol, 1902; montandon, 1933) or “marocche di vedana” (dal piaz, 1912; venzo, 1939), is a blocky deposit located south of mt. peron (1486 m a.s.l.), 8 km west of belluno (figs. 1, 3). this deposit is one of the biggest landslide deposits in the alps (heim, 1932; abele, 1974; eisbacher & clague, 1984), covering an area of about 9 km2, having a maximum thickness of 40 m and an estimated volume of more than 100 mm3 (abele, 1974; genevois et al., 2006; pellegrini et al., 2006). many researchers dealt with this deposit in the past. the masiere di vedana was interpreted to be lateglacial (pellegrini et al., 2006) to historic in age (piloni, 1607; miari, 1830; rossato et al., 2020). even its origin was debated; it has been suggested to be: i) a glacial deposit (hoernes, 1892), ii) landslide debris transported by a glacier during the lateglacial (mazzuoli, 1875; squinabol, 1902; dal piaz, 1912; venzo, 1939; pellegrini, 2000; pellegrini et al., 2006), iii) a catastrophic flood deposit (taramelli, 1883) and iv) a complex rock avalanche (genevois et al., 2006; rossato et al., 2020). a recent study combining geomorphological and stratigraphic evidence, cosmogenic dating and literature review finally defined the masiere di vedana as a rock avalanche that occurred between late roman times and the early middle ages (rossato et al., 2020). fig. 3 panoramic view of the northern side of the piave valley, with the location of the masiere di vedana deposit and the major peaks and towns highlighted. rossato s. et al. 3.2. setting the rock mass detached from the southern side of the mt. peron (1486 m a.s.l.). this peak is part of the ene-wsw oriented coppolo-pelf anticline and belongs to the hanging wall of the belluno thrust, which crops out at the base of its southern rocky wall. the landslide crown area comprises, from west to east, calcari grigi group (lower-middle jurassic), calcare di vajont (middle jurassic), fonzaso formation, rosso ammonitico (upper jurassic) and maiolica (cretaceous) limestones. the strata are sub-vertical to slightly overturned (doglioni, 1990; costa et al., 1996). the main scarp is partially circular, 800 m wide and 700 m high, s-to-sw facing. mt. peron is dissected by a wealth of fractures and faults, that can be grouped into five main discontinuity sets. these comprise: (1) bedding, (2) wsw-ene directed frontal thrust planes, (3) se dipping backthrustrelated planes, (4) nw-se aligned local conjugate fracture planes sets, and (5) persistent n-s oriented planes (fig. 4; rossato et al., 2020). presently, myriad large and small individual rock prisms bounded by these discontinuities are present at high elevation in the crown area (di giusto, 2012). 3.3. landslide kinematics and characteristics the plain south of mt. peron is covered for ~9 km2 by rock avalanche deposits, corresponding to an estimated total debris volume of ~170 mm3 (detached rock mass: ~130 mm3) (rossato et al., 2020). the deposit is lithologically zoned, the rocks found in the proximal sectors corresponding to geological units outcropping in the western part of the detachment area (i.e., calcari grigi group), while the more distal ones mimic the strati 213 fig. 4 structural scheme of the mt. peron main scarp, on its southern side. the main frame is a photograph (shot from vedana sector towards the north-east, see fig. 5 for location) with major structural elements and morphologic features highlighted. the frame below hosts the lower hemisphere stereographic projection of principal structural elements. colours in the frames correspond to the same systems. from the past to the future: landslides in the piave valley graphic sequence of the eastern side (i.e., calcare del vajont, fonzaso, rosso ammonitico and maiolica formations). the mobility of rock avalanches depends strongly on the involved volume, especially in nonconfined setting (strom, 2006). the masiere di vedana rock avalanche travelled about 5,900 m, a distance that can be achieved only hypothesizing a single massive failure. the calculated h/l ratio of ~0.2 (fahrböschung angle of 11°) (rossato et al., 2020) marks this event as extremely mobile, compared to other rock avalanches (aaron & mcdougall, 2019). the masiere di vedana rock avalanche ran only partially over cenozoic rocks and pleistocene conglomerates, the vast majority of the path material being constituted by alluvial and glacial deposits, with scattered humid sectors (fig. 5; rossato et al., 2020). the presence of loose, saturated substrate like that described for the masiere di vedana event is proved to favor longer travel distances, thinner debris tongues, and wider debris distribution (aaron & mcdougall, 2019). based on spatial pattern, boulder lithology and morphological character, we distinguish five sectors of the deposits: peron, vedana, torbe, masiere, and roe (roe alte and roe basse) (fig. 5). 214 the peron sector includes the talus apron deposits at the foot of mt. peron, the rock avalanche deposits on the east side of the river and the terrace of peron town (at about 380 m a.s.l.). in the vedana sector, the rock avalanche deposit displays a highly irregular, thinly forested topography with huge blocks hundreds of cubic meters in size. locally, glacial sediment is incorporated into the base of rock avalanche. the torbe sector encompasses the distal rock avalanche deposits of the lobe north of castel cuch where isolated conical hills and hummocks (“toma”; more & wolkersdorfer, 2019) emerge from a flat topography. in the flat area a few meters of silty sands cover the rock avalanche deposits, likely due to fluvial deposition by the cordevole river. the masiere part is a vegetation-free, desert-like expanse of limestone blocks. boulders are metersize and abundant angular and sub-angular clasts, lacking fine matrix in the surficial deposits. the areas of roe alte and roe basse comprise the distal sector; very few boulders immersed in a sandy matrix are scattered in the meadows. the roe basse sector is made of alluvial sediments which fig. 5 geological map of the masiere di vedana, see location in fig. 1. the boundary of mt. peron rock avalanche deposits is marked with solid white line, whilst the contact between quaternary sediments and bedrock is shown with solid black line. the location of boulders sampled for dating (red stars) are shown. archaeological findings are indicated by red squares. location of stratigraphic sections (yellow ellipses) and paleo-cordevole paths (black dashed arrows) are shown. (modified from: rossato et al., 2020) rossato s. et al. mantle the rock avalanche deposit on the northwestern side. locally, the rock avalanche shows direct and sharp basal contact with glacial sediment. pore pressure increase and seismic shaking are the principal contenders when trying to identify the actual trigger of failure in rock avalanches, that may even start without a definite external event (wieczorek, 1996; schuster & wieczorek, 2002; takahashi, 2001). the area near belluno has a high mean annual rainfall (1643 mm in the time interval 1994-2018; https:// www.arpa.veneto.it/dati-ambientali/open-data) and extreme rainfall events are recorded, even in recent times (e.g., >300 mm of rain at sospirolo during a single event: 27th october 1st november 2018; arpav, 2018). severe rainfall periods occurred also at the time of the event (wirth et al., 2013; rossato et al., 2015) and may have triggered, or have contributed to, the masiere di vedana rock avalanche. the veneto region is susceptible to seismic activity and has experienced several major earthquakes in the last few hundred years, some up to mw 6. a couple of historic earthquakes occurred in the time frame of the masiere di vedana, but no direct relationship is proved. however, an important consequence of frequent seismic activity is the decrease of mechanical properties of the rock mass, with the propagation of failure planes and the reduction of roughness on discontinuities (friedmann et al., 2003; brideau et al., 2009; parker et al., 2013; stead & eberhardt, 2013; preisig et al., 2015; gischig et al., 2016). the masiere di vedana rock avalanche may have been triggered by an exceptional meteorological event, an earthquake, or a combination of them. nevertheless, no exceptional event may be required for such rock avalanches to occur, as the accumulation of damage markedly lowers the energy needed to trigger a failure (rossato et al., 2020). the rock mass likely moved at the beginning as toppling and/or sliding, evolving into a flow-like movement of crumbling rock debris, extremely variable in size (from clay/silt up to plurimetric boulders) and remarkably mobile (rossato et al., 2020). numerical modelling suggests the presence of high pore water pressures (genevois et al., 2006), further enhancing the mobility of the moving mass, that traveled for some kilometers and overcame obstacles such as the castel cuch ridge (fig. 5), as rock avalanches typically do (e.g., hungr et al., 2001; mangeney et al., 2010; bowman et al., 2012). today, numerous partially detached rock prisms are evident along the upper part of the mt. peron rock wall. as the same predisposing factors that likely led to the rock avalanche (pervasively fractured rock, vertical strata, fracture planes cutting the stratigraphic sequence) and triggers (seismicity and/or extreme rainfall events) are still present, a re-evaluation of the landslide hazard may be necessary. 4. the 1963 vajont landslide (vj) 4.1. historical background the 1963 vajont landslide, located in the vajont valley (fig. 1) is one of the best-known examples of disasters caused by human activity. the vajont double arch dam stands 261.6 metres above the valley floor and was the world’s highest thin arch dam when it was built. the planned full reservoir capacity was 169 million 215 fig. 6 a (left): structural sketch of the vajont area (modified after riva et alii, 1990). b (right): geomorphological sketch map of the vajont valley. legend: a vajont landslide; b la pineda landslide; c salta rock fall; d landslide scarp; 1 slope deposits; 2 fluvial deposits; 3 marls, marly limestones and flysch (marne di erto and flysch formation, palaeocene p.p.-eocene); 4 reddish and nodular limestones, white micritic limestones (rosso ammonitico, maiolica, scaglia rossa, lower cretaceous-lower palaeocene p.p.); 5 white oolitic and bioclastic calcarenites, grey dolomitized micrites and limestones with interlayers of thin clays (soverzene formation, igne formation, calcare di vajont formation and fonzaso formation, jurassic); 6 white or grey massive dolomite (dolomia principale, upper triassic); a fault; b uncertain fault; c overthrust (from pasuto a., 2017). from the past to the future: landslides in the piave valley m3. on october 9th, 1963, during the third filling of the reservoir, a mass of approximately 270 million m3 detached from the northern side of mt. toc and slid into the water at velocities up to 30 m/s. a wave subsequently overtopped the dam by 250 m and swept into the piave valley below, resulting in approximately 2,000 deaths. the sliding lasted less than one minute and produced seismic shocks, which were recorded throughout europe. remarkably, the dam remained intact: it withstood a load eight times greater than that it was designed to withstand. 4.2. setting the vajont valley coincides with the core of an alpine syncline (erto syncline) with an e-w to wnw-ese trending axis gently plunging towards the e. the erto syncline lies on the hanging wall of the belluno thrust and is paired with the trailing limb of a main frontal asymmetric anticline located to the south. the sliding layered sequence was laterally constrained by a system of subvertical faults (croda bianca and col tramontin lines to the east and west branch of the col delle erghene line to the west), while the crown was constrained by e-w striking structures (col delle erghene line) (fig. 6a). the landslide involved jurassic and cretaceous rocks (limestones and marls belonging mainly to the calcare di soccher, rosso ammonitico, and fonzaso formations) showing varying degrees of fracturing. in the vajont valley and adjacent mountain groups, geological formations range in age from the upper triassic (dolomia principale) to the middle eocene (flysch) (figs. 2, 6b). they are mainly represented by limestones and dolostones. here, several huge landslide accumulations of different age and size are present (fig. 7) (ghirotti et al., 2020). the most impressive one is certainly that related to the october 1963 catastrophic landslide. 4.3. landslide kinematics and characteristics during the third reservoir filling operation, the northern slope of mt. toc failed suddenly over a length of 2 km and a surface area of 2 km2. the slide displaced a 250 m thick mass of rock some 300 to 400 m horizontally with an estimated velocity of 20 to 30 m/s, before running up and stopping against the opposite side of the vajont valley. the majority of the slide moved as a whole and reached the opposite side of the valley without any change in shape apart from a general rotation evident from both the surface morphology and the stratigraphic sequence that remained essentially unchanged after the movement (fig. 8). it is remarkable that the massalezza creek, that was flowing from mt. toc before the event, did not change much its path and is still flowing longitudinally across the fallen mass (fig. 6b). in 1960, f. giudici and e. semenza discussed the geology in detail and put forward the hypothesis of the existence of a very old landslide on the left bank of the 216 vajont reservoir area. during their surveys they discovered a highly fractured zone (“mylonite”) extending about 1.5 km along the left side of the valley corresponding to the terminal sliding plane of a prehistoric landslide (semenza & ghirotti, 2000). nevertheless, the dam owners concluded that a deep-seated landslide was very unlikely to occur, mainly because of the good quality of in situ rock masses, as derived from seismic surveys and drillings. fig. 7 drone photo of the main landslide body. fig. 8 aerial photograph taken a few days after the landslide (photo: selli et al., 1964). this picture clearly shows the vegetated tails of the two main lobes. the surviving vegetation highlights that these areas were not affected by the returned wave displaced by the landslide. the trees moved downslope approximately 600 m and were rotated uphill. the red circle indicates the “bosco vecchio”. rossato s. et al. today, it is almost unequivocally accepted that the 1963 failure occurred mostly along planes of weakness represented by 0.5-18 cm thick clay-rich layers (fig. 9) within the fonzaso formation (hendron & patton, 1985). however, the continuity and the existence itself of clay interbeds in the calcareous sequence and the hypothesis of a paleolandslide represented a controversial aspect for many decades. hendron & patton (1985) stated that the increase in pore water pressure due to the raising of the water level in the reservoir caused a decrease in effective normal stress, favouring the sliding on these clay layers characterised by a residual friction angle �r between 8° and 10°. movement occurred along a circular to chairshaped failure surface at or close to residual strength (fig. 10), which is hypothesized to be either a reactiva 217 fig. 9 clay interbeds outcropping on the sliding surface (at left) and a sketch of the fonzaso fm. outcrop southwest of casso (adapted from hendron & patton, 1985). fig. 10 geological sections before and after october 9, 1963 (hendron & patton, 1985, section 2 and 5). from the past to the future: landslides in the piave valley tion of a paleo sliding surface (semenza & ghirotti, 2000; semenza, 2010) or have evolved from deepseated gravitational movement over millennia (e.g., wolter et al., 2016). according to some authors (dykes & bromhead, 2018a; 2018b), there is no paleo landslide at all. the stratigraphic sequence remained essentially unchanged after the movement and the deposit has preserved, after the slide, the main systems of discontinuities and folds present before 1963. some major vertical fractures were formed during failure, and the preexisting sets were rotated according to the direction of the movement. geological and tectonic evidence suggests that the landslide was limited by one or more faults (massironi et al., 2013). the sliding plane has an overall concave shape with the eastern and western (i.e., the lateral) lobes converging toward massalezza creek (fig. 6b), which coincides with the hinge of the massalezza syncline. the result is that the vajont failure surface is neither sharp nor smooth. the most tectonized sector of the sliding plane is downstream of massalezza creek where the hinges of the erto and massalezza synclines interfere with each other. the orientation of the failure surface is the product of at least two episodes of folding, which formed the multiple steps that are observed on the failure surface. all of these elements, mainly predating any gravitational event on the mt. toc northern slope, may have played a significant role in failure behaviour. the massalezza syncline and related concave shape of the sliding surface played a major role in the evolution of the 1963 vajont landslide, favouring the collapse of the two main lobes (eastern and western) that followed two slightly different and northward converging sliding paths. as regards the failure surface morphology, important differences, moving from west to east along it are present (fig. 11; more details can be found in wolter et al., 2014; 2016): the western area has a “chair-like” shape and is much smoother than the central folded area. it is marked by one large and several smaller steps, as well as conjugate discontinuities; but the failure surface remains, more or less, in the same stratigraphic interval that contains the clay-rich levels (fonzaso fm.). the central part of the sliding 218 surface, incised by the massalezza creek, is highly tectonized and characterized by the presence of a large fold with smaller parasitic folds along its limbs. the eastern sector, limited by the col tramontin (ctr) fault (figs. 6, 10), has a pronounced convexity and an irregular shape: moving from massalezza stream towards east, multiple steps with different strikes allowed the failure surface to rise in the stratigraphic sequence. the ctr fault represents the eastern boundary of the 1963 slide to which hendron & patton (1985) attributed about 40% of the total resistance of the landslide mass. the ctr fault also prevented the propagation of the landslide eastward because, east of it, the fonzaso fm., in which most of the failure surface developed, and the overlying calcare di soccher fm. that forms the 1963 accumulation body, actually dip sharply northward and therefore do not outcrop in the vajont gorge. the ctr fault also represented a permeability boundary that could affect the groundwater flow system of the landslide mass. hydrogeological investigation, yet to be completed, might clarify the question and lead to a reliable hydrogeological scheme of the area. the vajont landslide has a very rich scientific literature (superchi et al., 2010). still today some authors deny the existence of the paleo landslide (dykes & bromhead, 2018a; 2018b) while others try, through the use of numerical models and new techniques, to construct an evolutionary geological model of one of the most complex and destructive landslides that have ever occurred (paronuzzi & bolla, 2012; wolter et al., 2013, 2016; franci et al., 2020a, 2020b). 5. the tessina landslide (ts) 5.1. historical background the tessina landslide has been evolving continuously since 30 october 1960, when, following intense and continuous rainfall (398.7 mm up to that day), a 300 m long, 100 m wide, and 20 m thick front detached from the slopes of mt. teverone (fig. 1). further activations were documented up to the present day and now the landslide has enlarged to an area of more than 550,000 m2, becoming one of the most active landslides in the fig. 11 morphologies of the sliding surface (eastern lobe at left and western lobe at right). rossato s. et al. eastern italian alps. the landslide can be divided into three different geomorphological zones (fig. 12): an upper source area that is characterized by rotational slides and intense disruption, a collector channel where the fractured material is progressively remoulded and infiltrated by water turning into a mudflow, and a lower accumulation channel where the mud flows reach down to the villages of funes and lamosano. the landslide extends between the elevations of 1220 and 625 m a.s.l. and has a total length of almost 3 km and a maximum width of about 500 m. it has been used as a “natural laboratory” to test innovative monitoring systems, given its extent, several optimal monitoring points, and continuous reactivations (avolio et al., 2000; mantovani et al., 2000; hervas et al., 2003; tarchi et al., 2002; cola et al., 2016; gabrieli et al., 2016). 5.2. setting in the tessina basin, the flysch formation is faulted and folded, partially eroded, and bounded to the north by the highly fragmented limestone mass (calcare del fadalto; jurassic-cretaceous) of mt. teverone (figs. 2, 13). thin (1-2 m) outcrops of marl and marly limestone scaglia rossa (cretaceous-palaeocene) are visible at the base of the mountain, where they are irregularly interposed between the steep cliffs of mt. teverone and the highest scarps of the landslide. the scaglia rossa is distinguishable along the upper border of several scarps due to its rose colour and marks the beginning of the unweathered flysch in the upper part of the source area. moraine deposits cover the flysch to the nw (moda) and ne (roncadin and pian de cice) of the landslide, while other surficial quaternary deposits were mobilized by the landslide in the past and mixed with the shallow, loosened flysch. 5.3. landslide kinematics and characteristics the main predisposing factor of tessina landslide is the presence of the flysch formation, a stratified sedimentary unit (middle eocene) that is 1000-1200 m thick and mainly composed of sandstone, lowpermeability marl, and clays. a secondary predisposing factor is the tectonic setting: the rainfall and snowfall infiltrating into the carbonate massif of mt. teverone are then conveyed through sub-vertical fractures in the flysch (less permeable) towards the landslide body (fig. 13). evidence of this behaviour is the numerous springs, sometimes under a perennial regime. a drainage tunnel built in the 1990s in the carbonate massif of mt. teverone had the effect of smoothing out the flow peaks but did not eliminate these springs, nor significantly reduce the activity of the landslide. 219 fig. 12 aerial view of the landslide in 1995 (source: irpi archive): the crown area, object of photographical monitoring, to the main collector channel and the lower deposit. fig. 13 schematic geological profile along the thalweg of the tessina valley (adapted from cola et al. 2016). from the past to the future: landslides in the piave valley the third driving and triggering factor is related to the pluviometric regime of the area: according to 20 years of hourly rainfall data (1994-2014; san martino weather station, located about 40 km to the west) the mean annual precipitation is 1683.3 mm, with an average of 121 rainy days a year and a slight bimodal seasonality with peaks in november (203.1 mm) and spring. this is one of the rainiest areas of the veneto region. moreover, through photogrammetric observations (gabrieli et al., 2016) the close link between seasonal monthly movements and cumulative precipitation has been demonstrated (fig. 14). such a connection has been observed and described with a similar approach also in other cases involving large debris volumes (e.g., the super-sauze landslide in the south french alps; travelletti et al., 2012), or smaller, but very active, erosion forms such as gullies (e.g., the gullies in the guadalentín basin in the province of murcia, southeast spain; marzolff & poesen, 2009). a landslide dating back to before the triggering of the current slide in 1960 was identified by analysing multitemporal aerial photographs and digital elevation models (van westen & lulie getahun, 2003). after the first large rotational slide occurred in october 1960, ~1 million m3 of weathered flysch and quaternary deposits were mobilised and reached the villages of funes and lamosano downstream. in the following years, other reactivations caused the tessina valley to be filled with a 30-to-50 m thick deposit (pasuto & silvano, 1995). the landslide deposit reached the same elevation of the village of funes, once located on a promontory. landslide activity seemed to decline until 1987 when several movements in the mudflow channel were documented. a further 2.5 million m3 of material mainly composed of flysch, glacial sediments and scree deposits located in the northeast sector of the source area were reactivated in 1992 and 1995 after a rainy period, causing the damage of some infrastructures and increasing the level of risk for the villages below (pasuto & silvano, 1995). while the activity of the oldest source section in the north-west seemed to decrease from 1969 to 1980, the central and eastern part discharged material with increasing frequency. the landslide is still active both in the crown area and in the side scarps with movements related to rainfall and underground water flows (mantovani et al., 2000; cola et al., 2016). the presence of a low-permeability retaining structure in the flysch formation below the depletion basin, which periodically fills with water-saturated material, seems to play a role in the intermittent dynamics of the landslide movements (dall’olio et al., 1987). different numerical modelling techniques like cellular automata (avolio et al., 2000) and smooth particle hydrodynamic integration method (cola et al., 2008) have been used to simulate the runout phase from the upper basin. moreover, thanks to recent photogrammetric monitoring activity it was possible to study the wormlike movement of the mudflow from a probabilistic point of view and to examine in depth the mechanism of the movement (gabrieli et al., 2016, cola et al., 2019). 220 6. the mt. peron possible instabilities (mp) 6.1. setting the mt. peron (figs. 1, 15) presents as a very well exposed scar, about 800 m wide and 800 m high, subvertical and represented by a rocky cliff almost inaccessible to field-based measurements due to the absence of trails on the mountainside. in the scar area, many potentially unstable blocks are present, threatening the peron village, at the base of the cliff. some structural data have been collected in the adjoining sectors, thanks to traditional field survey and observations, and to a structural transect surveyed along a vertical rappelling descent route. with the aim of increasing the number of measurements, we tested the possibility to integrate field data with structural measurements taken on a virtual 3d model, reconstructed through photogrammetric techniques applied to a photographic survey acquired by an unmanned aerial vehicle (uav). this work focused on an area located at the top of the landslide scar, in the western side (fig. 15). here, the rock mass is made of lower jurassic limestones belonging to the calcari grigi group (fig. 2). the 3d model was built with 145 photos taken using a commercial uav (phantom 4 by dji). from those images a point cloud of more than 6 million points, with an average spacing of 10 cm (fig. 16a) has been built by means of the structure from motion and multiview stereo technique (sfm-mvs; e.g., westoby et al., 2012), through the software agisoft metashape©. orientations of 159 planes (bedding and fractures) were measured and analysed in order to recognize clusters of fractures (i.e., fracture sets). figure 16b shows the 4 sets of discontinuities observed over the mountain side and the stereographic plot of the poles of those planes. 6.2. fracture measurements in the 3d model fracture orientations were statistically analyzed and clustered in sets by means of the software wintensor v.5.8.8 (delvaux & sperner, 2003; http:// d a m i e n d e l v a u x . b e / t e n s o r / w i n t e n s o r / w i n tensor_download.html). first, we clustered the poles to the fracture planes through a k-means algorithm (macqueen, 1967): the number of clusters is fixed a fig. 14 monthly cumulative rainfalls and displacement occurrences captured from automatic photogrammetric monitoring from december 2011 to may 2013 (adapted from gabrieli et al. 2016). rossato s. et al. priori by the operator and the calculator finds the centroids of the clusters that minimize the total intra-cluster variance and maximize the inter-cluster distance. number of clusters were fixed with a visual inspection of the data, aided by density contouring of fracture poles. the output includes the orientation of the fracture sets, the fisher’s dispersion factor (i.e., k value) and the mean cone angle (mca) enclosing the data distribution. we have recognized four sets of fractures (i.e., s0, k1, k2 and k3; fig. 16b) with 18 random discontinuities, not belonging to any set. the first cluster, s0, represents the bedding, corresponding to sub-vertical planes striking ca. wsw-ene. the cluster k1 represents a principal sub-vertical fracture system, nw-se-striking, that cuts through the bedding. clusters k2 and k3 represent two secondary and less pervasive discontinuity systems. the four detected fracture sets have been compared with field-based measurements, taken at the base of the rock cliff and along a rappel descent on the same sector of the three pillars and during a field survey in close sectors of the mt. peron sides. both the datasets are well matching and provide a common interpretative model. the bedding, together with the other high-angle discontinuity (i.e., k1), provide the more pervasive fractures leading to the fragmentation of the rock mass into potentially unstable pillar-like blocks bounded at the base mainly by the k2 and k3 sets. the analyzed area is lacking significant south-dipping discontinuities, potentially favorable to the cliff instability. nonetheless, a field survey at the base of the rock cliff highlighted the presence of a moderately dipping fault zone (i.e., the mt. peron backthrust; fig. 16d) that could be a slipping surface for the rock cliff described above. the presented data are essential for modeling possible failures and for a conscious and prudent management of the area by the stakeholders (e.g., the municipality of sedico, to which the village of peron belongs; figs. 5, 15). the volume of the detaching rock masses, the travel paths, and the deposition areas are variables that can be simulated and predicted (e.g., with the 3 distinct element method for stability analysis; spreafico et al., 2014), preventing damages and casualties. 7. discussion and conclusions the described landslides occurred, are occurring, and may occur in a relatively small, but densely inhabited area. except for modelling, all the case studies are well known, with a vast literature that investigated them in-depth with different methods. main approaches are summarized in table 1, whilst the various aspects investigated for each landslide are gathered in table 2. to avoid multiple repetitions, in this section the following acronyms will be used instead of the complete names of the landslides: mv (masiere di vedana), vj (vajont), ts (tessina), and mp (mt. peron). all case studies are strongly based on the investigation of the crown area, the detached rock mass, and the deposit. similarly, field surveys and remote sensing have been adopted for all cases, but with different focus and methods. it is quite reasonable that when dealing with past events (i.e., mv and vj) the prime features to be investigated are the deposits. this is due both to the accessibility of the landslide mass, that usually lies in the valley 221 fig. 15 aerial view of the mt. peron crown (view from the south); the area included in the virtual outcrop, south facing and near vertical, with its dimensions, the take-off location of the uav and the area reconstructed in 3d by means of a photogrammetric approach. from the past to the future: landslides in the piave valley 222 fig. 16 a) dense point cloud of the virtual outcrop and measured fracture planes (in blue); b) stereoplot of the clustered data (poles to planes) with the resulting mean orientation of each cluster (red small circles), mean cone angle (red continuous line) and the external limit of each cluster (red dashed line); c) uav-based imagery of the crown area with illustrative fractures sets highlighted; d) south-dipping planes ascribable to shear planes of the mt. peron backthrust (main planes are highlighted in red). rossato s. et al. bottom and may be easily sampled/investigated, and the difficulties that are encountered in reaching the crown. looking at the mt. peron area this focus on deposit in such studies can be clearly appreciated. the southern side of this peak, an 800 m wide and about 700 m high rock wall, is the source area of the mv event but also hosts the rock prisms modelled in the mp. in both cases, the cliff has been investigated with remote sensing techniques and field surveys, but this phase is much more important in the mp case, compared to mv. in the former case, specifically designed photogrammetric surveys have been performed, to allow a virtual geomechanical characterization of the bedrock, the construction of a 3d model, and the identification of fracture planes in the rock wall. in the mv case, only field surveys were carried out to characterize the structural setting of the bedrock and to investigate the stratigraphic sequence, but little attention was devoted to specific present-day potential instabilities. on the contrary, the deposit was considered the most valuable source of information and many field surveys have been performed. vj and ts are intermediate cases, having a quite accessible crown area where new detachments can take place. in the mv case, despite most investigations having been performed on the deposit, uncertainties remain, mostly because of the reworking processes that have taken place since the event, including anthropogenic activity. at the opposite extreme, the mp study focused on the source area and the pre-detachment geometry of the crown. the data acquired with this study are essential input values for numerical models focusing on the possible travel paths and deposition areas of future failures. apart from the acquired input data, the precision and reliability of such numerical simulations depend solely on the adopted model itself. the kinematics of a given landslide reflect directly on the land management of the area, but the identification of this parameter strongly relates to the age of the failure: the younger the event, the better its characterization. as it can be appreciated by looking also at table 2, the actual moment of failure may be defined almost perfectly, if monitoring is ongoing when the event starts or people are affected by it (i.e., vj and ts), or with an error up to some centuries, when absolute dating methods (e.g., 10be or 14c) or historical records (i.e., mv) are used. in contrast, when dealing with future events like mp, the moment of failure may be totally unknown, depending on factors that cannot be completely estimated. the examples in this paper showed possible triggers of pore pressure increase (i.e., mv, vj, and ts), and seismic shaking (i.e., mv, and mp), but many driving factors (e.g., fracturation of the rock mass, strata alternations, the presence of tectonic structures and fracture planes) have been identified. the comprehension of the stratigraphic, structural, and geomechanical characteristics of the rock mass proved to be essential to reconstruct 223 tab. 1 list of the methods applied in each case study. for each method is given a qualitative estimation of its accuracy and importance for the specific case study (high=green, medium=orange, poor=red). tab. 2 list of the features describing each considered landslide. for each case is given a qualitative estimation of the accuracy (from the worst to the best: unknown, supposed, estimated, known) and reliability (high=green, medium=orange, poor=red) of the result. from the past to the future: landslides in the piave valley the dynamics of the failure in all case studies. the influence of a given parameter is connected to the specific setting, and the reliability of the final result may vary even in similarly investigated scenarios. age plays an important role also in this case: the triggers of remote and future events are difficult to identify, and often no more than hypotheses can be proposed. disaster management in landslide-prone areas can be articulated in four different steps: mitigation, readiness, response, and recovery (cartwright, 2005). even a few minutes may be enough to activate emergency plans and save lives (e.g., casagli et al., 2010; manconi et al., 2016, gallen et al., 2017). it is known that the accumulation of rock damage may be sufficient to reach the point of failure (e.g., stead & eberhardt, 2013; donati et al., 2020). some signs of movement can precede the collapse (e.g., glastonbury & fell, 2010) and, when a failure is considered possible, monitoring of the source area and/or the probable travel path can be activated, as in the vj and ts cases. at vj, piezometers and markers were placed within the landslide to monitor displacements and pore pressures immediately prior to the 1963 failure. at vj, some signs preceding the event were present but were not correctly recognized, as occurred also in other cases (e.g., the val pola rock avalanche, 20th july 1987, and the brenva ice avalanche, 18th january 1997). at ts, total station and gnss monitoring is still active. gnss provides values almost in real time, being able to vary the measuring interval in response to the trend of displacement. other instrumentations have been placed at specific valuable sites (e.g., near the village of funes), but the excessive costs and the need of continuous maintenance limit their application. early warning systems can be designed to alert the population and reduce landslide risk. such systems are clearly site-specific, depending, for example, on the type of landslide (lacasse & nadim, 2009), but they are all based on the identification of the movement, the forecasting of the evolution of the event, the alert of the population, and the activation of response plans (intrieri et al., 2012). adequate prevention actions are pivotal to manage and to reduce casualties and damages to infrastructures (casagli et al., 2010). numerical modelling can help in the identification of the sectors of the slope where failure is more likely to occur, of the most probable travel path, and the potential runout distance of debris. the mp case is a clear example of state-of-the-art acquisition of data required for the modelling of possible instabilities, but also in all other cases numerical simulations have been performed. the vj case perfectly highlights both the risk deriving from poor modelling based on poor input data (ghirotti et al., 2013) and the continuous improvement in this field (alonso & pinyol, 2010; paronuzzi & bolla, 2012; wolter et al., 2013, 2016; franci et al., 2020a, 2020b). data deriving from real cases are fundamental to adjust numerical models and verify their output (e.g., cola et al., 2019; von wartburg et al., 2020). in this line, particular care should be dedicated to data collection for model inputs. a recommended approach should integrate field and remote-based techniques: the first provide data from close observations, not obtainable 224 through remote sensing (e.g., fracture opening or weathering) and constitute a ground-truth for remote sensing itself; the latter provide a spatially continuous distribution of data over a wider range of scales and offer the opportunity to test the 3d characterization of geological features (e.g., pless et al., 2015). the understanding of real cases that occurred in the past is intertwined with modelling of future events, each aspect benefiting from improvements on the other one. acknowledgements the authors are grateful to dr gianfranco fioraso and an anonymous reviewer for their useful comments and suggestions, that significantly improved the quality of the paper. the authors deeply also thank the editor, dr andrea sposato. references aaron j., mcdougall s. (2019) rock avalanche mobility: the role of path material. engeneering geology, 257, 105126. doi: 10.1016/j.enggeo.2019.05.003 abdulwahid w.m., pradhan b. (2017) landslide vulnerability and risk assessment for multi-hazard scenarios using airborne laser scanning data (lidar). landslides, 14(3), 1057-1076. abele g. (1974) bergstürze in den alpen. ihre verbreitung, morphologie und folgeerscheinungen. wiss. alpenvereinshefte 25, munchen. alonso e.e., pinyol n.m. (2010) criteria for rapid sliding i. a review of vaiont case. engineering geology, 114 (3-4), 198-210. doi: 10.1016/j.enggeo.2010.04.018 arpav (2018) technical report on the 27/10/2018 01/11/2018 meteorological event. regione.veneto.it/c/document_library/get_file? uuid=094022ae-43e7-46b1-86d2-ff3ebf669b89 &groupid=90748 avolio m.v., di gregorio s., mantovani f., pasuto a., rongo r., silvano s., stataro w. (2000) simulation of the 1992 tessina landslide by a cellular automata model and future hazard scenarios. int. j. appl. earth obs. geoinf., 2 (1), 41-50. bigi g., cosentino d., parotto m., sartori r., scandone p. (1990) structural model of italy, scale 1: 500,000. cnr, progetto finalizzato geodinamica, firenze. bowman e.t., take w.a., rait k.l., hann c. (2012) physical models of rock avalanche spreading behaviour with dynamic fragmentation. canadian geotechnical journal, 49(4), 460-476. brideau m.a., yan m., stead d. (2009) the role of tectonic damage and brittle rock fracture in the development of large rock slope failures. geomorphology, 103 (1), 30-49. carton a., bondesan a., fontana a., meneghel m., miola a., mozzi p., primon s., surian n. (2009) geomorphological evolution and sediment transfer in the piave river watershed (north-eastern italy) since the lgm. géomorphologie: relief, processus, environnement, 3, 37-58. cartwright s. (2005) national civil defence emergen rossato s. et al. cy management plan order 2005. published under the authority of the new zealand government, wellington, new zealand, pp. 68. carulli g.b., cozzi a., longo salvador g., pernarcic e., podda f., ponton m. (2000) geologia delle prealpi carniche. edizioni museo friulano di storia naturale, udine, italy, pp. 48. casagli n., catani f., del ventisette c., luzi g. (2010) monitoring, prediction, and early warning using ground-based radar interferometry. landslides, 7(3), 291-301. cola s., calabrò n., pastor m. (2008) prediction of the flow-like movements of tessina landslide by a sph model. the 10th is on landslide and engineering slopes. xi’an, china, vol. i, 647-653, taylor, francis, the netherlands cola s., gabrieli f., marcato g., pasuto a., simonini p. (2016) evolutionary behaviour of the tessina landslide. rivista italiana di geotecnica, 50(1), 51-79. cola s., brezzi l., gabrieli f. (2019) calibration of rheological properties of materials involved in flowlike landslides. rivista italiana di geotecnica, (1), 543. costa v., doglioni c., grandesso p., masetti d., pellegrini g.b., tracanella e. (1996) note illustrative della carta geologica d’italia alla scala 1: 50.000: foglio 063 belluno. istituto poligrafico e zecca dello stato, roma. crosta g.b., chen h., lee c.f. (2004) replay of the 1987 val pola landslide, italian alps. geomorphology, 60(1-2), 127-146. d’agostino n., avallone a., cheloni d., d’anastasio e., mantenuto s., selvaggi g. (2008) active tectonics of the adriatic region from gps and earthquake slip vectors. journal of geophysical research, 113, b12413. dal piaz g. (1912) studi geotettonici sulle alpi orientali: regione fra il brenta e i dintorni del lago di santa croce. memorie dell'istituto geologico della real università di padova, 1, 1-195. dall’olio l., ghirotti m., iliceto v., semenza e. (1987) la frana del tessina alpago (bl). proc. vi congresso dell’ordine nazionale dei geologi, venezia, italia, 275-293. delvaux d., sperner b. (2003) stress tensor inversion from fault kinematic indicators and focal mechanism data: the tensor program. geological society, london, special publications 212, 75-100. di giusto m. (2012) pericolosità indotta dalla caduta massi dal monte peron valutazione geologica. technical evaluation for the municipality of peron, belluno, pp. 37. dilley m. (2005) natural disaster hotspots: a global risk analysis, vol 5. world bank publications, pp. 148. doglioni c. (1990) the global tectonic pattern. journal of geodynamics, 12 (1), 21-38. donati d., stead d., lato m., gaib s. (2020) spatiotemporal characterization of slope damage: insights from the ten mile slide, british columbia, canada. landslides, 17, 1037-1049. dykes a.p., bromhead e.n. (2018a) the vaiont landslide: re-assessment of the evidence leads to rejection of the consensus. landslides, 15(9), 1815-1832. dykes a.p., bromhead e.n. (2018b) new, simplified and improved interpretation of the vaiont landslide mechanics. landslides, 15(10), 2001-2015. eisbacher g.h., clague j.j. (1984) destructive mass movements in high mountains: hazard and management, geological survey of canada, vancouver, british columbia, canada, pp. 230. franci a., cremonesi m., perego u., crosta g., oñate e. (2020a) 3d simulation of vajont disaster. part 1: numerical formulation and validation. engineering geology, 279, 105854. doi: 10.1016/j.enggeo.2020.105854 franci a., cremonesi m., perego u., oñate e., crosta g. (2020b) 3d simulation of vajont disaster. part 2: multi-failure scenarios. engineering geology, 279, 105856. doi: 10.1016/j.enggeo.2020.105856 friedmann s.j., kwon g., losert w. (2003) granular memory and its effect on the triggering and distribution of rock avalanche events. journal of geophysical research: solid earth, 108 (b8). gabrieli f., corain l., vettore l. (2016) a low-cost landslide displacement activity assessment from time-lapse photogrammetry and rainfall data: application to the tessina landslide site. geomorphology, 269, 56-74. galadini f., poli m.e., zanferrari a. (2005) seismogenic sources potentially responsible for earthquakes with m>=6 in the eastern southern alps (thieneudine sector, ne italy), geophys. j. int., 161 (3), 739-762. gallen s.f., clark m.k., godt j.w., roback k., niemi a. (2017) application and evaluation of a rapid response earthquake-triggered landslide model to the 25 april 2015 mw 7.8 gorkha earthquake, nepal. tectonophysics, 714, 173-187. genevois r., armento c., tecca p.r. (2006) failure mechanisms and runout behaviour of three rock avalanches in the north-eastern italian alps. in: evans s.g., mugnozza g.s., strom a., hermanns r.l. (eds) landslides from massive rock slope failure. nato science series 49. springer, dordrecht, 407427. ghirotti m., masetti d., massironi m., oddone e., sapigni m., zampieri d., wolter a. (2013) the 1963 vajont landslide (northeast alps, italy): postconference field trip (october 10th, 2013). in: genevois r., prestininzi a. (eds) international conference on vajont 1963-2013: thoughts and analyses after 50 years since the catastrophic landslide. italian journal of engineering geology and environment book series no. 6, 635-646, sapienza università editrice, rome, italy. ghirotti m., borgatti l., marcato g. (2020) one of the hazardous neighbours of the vajont landslide: the historical mt. salta rock avalanche. alpine and mediterranean quaternary, 33, 2, 157-164. doi: 10.26382/amq.2020.11 gischig v., preisig g., eberhardt e. (2016) numerical investigation of seismically induced rock mass fatigue as a mechanism contributing to the progressive failure of deep-seated landslides. rock mechanics and rock engineering, 49(6), 2457-2478. 225 from the past to the future: landslides in the piave valley glastonbury j., fell r. (2010) geotechnical characteristics of large rapid rock slides. canadian geotechnical journal. 47, 116-132. heim a. (1932) bergsturz und menschenleben. vierteljahrschr. naturf. ges. zu �rich 20, beer & co., zurich, pagine?. hendron a.j., patton f.d. (1985) the vaiont slide, a geotechnical analysis based on new geologic observations of the failure surface. technical report gl-85-5, u.s. army eng. waterways experiment station, i, ii, vicksburg, ms, pp. 259. hermanns r.l., longva o. (2012) rapid rock-slope failures, in: landslides (types, mechanisms and modeling), edited by: clague, j. j., and stead, d., cambridge university press, cambridge, uk, 59-70. herrera g., mateos r.m., garcía-davalillo j.c. et al. (2018) landslide databases in the geological surveys of europe. landslides, 15, 359-379. hervás j., barredo j.i., rosin p.l., pasuto a., mantovani f., silvano s. (2003) monitoring landslides from optical remotely sensed imagery: the case history of tessina landslide, italy. geomorphology, 54(1-2), 63-75. hoernes r. (1892) der querbruch von santa croce und die bildung der schuttmassen von cima fadalto und der rovine di vedana bei belluno. zeitschrift der deutschen geologischen gesellschaft, 347-351. hungr o. (2006) rock avalanche occurrence, process and modelling. in: landslides from massive rock slope failure, edited by: evans s.g., scarasciamugnozza g., strom a.l., hermanns r.l.. nato science series, 49, 243-266. hungr o., evans s.g., hutchinson i.n. (2001) a review of the classi�cation of landslides of the flow type. environmental & engineering geoscience, 7 (3), 221-238. doi: 10.2113/gseegeosci.7.3.221 intrieri e., gigli g., mugnai f., fanti r., casagli n. (2012) design and implementation of a landslide early warning system. engineering geology, 147, 124-136. ispra (2018) consumo di suolo, dinamiche territoriali e servizi ecosistemici. rapp. 288/2018, pp. 280. isbn: 978-88-448-0902-7 lacasse s., nadim f. (2009) landslide risk assessment and mitigation strategy. in: sassa k., canuti p. (eds.), landslides-disaster risk reduction. springer verlag, berlin heidelberg, 31-61. macqueen j. (1967) an enriched k-means clustering method for grouping fractures with meliorated initial centers. some methods for classification and analysis of multivariate observations. proceedings of the fifth berkeley symposium on mathematical statistics and probability. california, usa, p. 14. manconi a., picozzi m., coviello v., de santis f., elia, l. (2016) real�time detection, location, and characterization of rockslides using broadband regional seismic networks. geophysical research letters, 43 (13), 6960-6967. mangeney a., roche o., hungr o., mangold n., faccanoni g., lucas a. (2010) erosion and mobility in granular collapse over sloping beds. journal of geophysical research: earth surface, 115, f03040. 226 marzolff i., poesen j. (2009) the potential of 3d gully monitoring with gis using high-resolution aerial photography and a digital photogrammetry system. geomorphology, 111 (1-2), 48-60. doi: 10.1016/j.geomorph.2008.05.047 montandon f. (1933) chronologie des grands éboulements alpins du début de l’ère chrétienne à nos jours. matériaux pour l'étude des calamités, 32, 271-340. mantovani f., pasuto a., silvano s., zannoni a. (2000) collecting data to define future hazard scenarios of the tessina landslide. int. j. appl. earth obs. geoinf., 2(1), 33-40. martin s., ivy-ochs s., viganò a., campedel p., rigo m., vockenhuber c., gabrieli f., mair v., rossato s. (2020) landslides of the western dolomites: case studies from the adige and sarca valleys (ne italy). alpine and mediterranean quaternary, 33, 2, 191207. doi: 10.26382/amq.2020.15 márton e., drobne k., �osovi� v., moro a. (2003) palaeomagnetic evidence for tertiary counterclockwise rotation of adria. tectonophysics, 377(1-2), 143-156. massey c.i., mcsaveney m.j., taig t., richards l., litchfield n.j., rhoades d.a., mcverry g.h., lukovic b., heron d.w., ries w., van dissen r.j. (2014) determining rockfall risk in christchurch using rockfalls triggered by the 2010-2011 canterbury earthquake sequence. earthquake spectra, 30 (1), 155-181. massironi m., zampieri d., superchi l., bistacchi a., ravagnan r., bergamo a., ghirotti m., genevois r. (2013) geological structures of the vajont landslide. italian journal of engineering geology and environment book series, (6), 573-582. mazzuoli l. (1875) sull'origine delle rovine di vedana. club alpino italiano, sez. di agordo, adunanza straordinaria dei soci il 22-8-1875 in vedana, 11-17. miari f. (1830) compendio storico della regia città di belluno e sua antica provincia. giuseppe picotti, venezia, pp. 144. monegato g., scardia g., hajdas i., rizzini f., piccin a. (2017) the alpine lgm in the boreal ice-sheets game. scientific reports, 7(1), 1-8. more k.s., wolkersdorfer c. (2019) an analogue toma hill formation model for the tyrolian fernpass rockslide. landslides, 16, 1855-1870. nicoletti p.g., sorriso-valvo m. (1991) geomorphic controls of the shape and mobility of rock avalanches. geol. soc. am. bull., 103 (10), 1365-1373. parker r., petley d., densmore a., rosser n., damby d., brain m. (2013) progressive failure cycles and distributions of earthquake-triggered landslides. in: ugai k., yagi h., wakai a. (eds) earthquakeinduced landslides. springer, berlin, heidelberg, 755-762. paronuzzi p., bolla a. (2012) the prehistoric vajont rockslide: an updated geological model. geomorphology, 169-170, 165-191 pasuto a. (2017) the vajont valley (eastern alps): a complex landscape deeply marked by landsliding. in m. soldati and m. marchetti (eds.), landscapes rossato s. et al. and landforms of italy, world geomorphological landscapes, 135-145. pasuto a., silvano s. (1995) the tessina landslide. in: horlick jones, t., amendola, a., casale, r. (eds.), natural risk and civil protection. chapman & hall, london. pellegrini g.b. (ed) (2000) note illustrative della carta geomorfologica d'italia foglio belluno. regione veneto servizio geologico d'italia, pp. 141. pellegrini g.b., surian n., albanese d. (2006) landslide activity in response to alpine deglaciation: the case of the belluno prealps (italy). geografia fisica e dinamica quaternaria, 29, 185-196. piloni g. (1607) historia della città di belluno. venezia, pp. 634. pless j.c., mccaffrey k. j.w., jones r.r., holdsworth r.e., conway a., krabbendam m. (2015) 3d characterization of fracture systems using terrestrial laser scanning: an example from the lewisian basement of nw scotland. geological society, london, special publications, 421(1), 125-141. preisig g., gischig v., eberhardt e., hungr o. (2015) hydromechanical versus seismic fatigue in progressive failure of deep-seated landslides. in: 13th isrm international congress of rock mechanics. international society for rock mechanics and rock engineering. riva m., besio m., masetti d., roccati f., sapigni m, semenza e. (1990) geologia delle valli vaiont e gallina (dolomiti orientali). annali università di ferrara (sezione scienze geologiche e paleontologiche), 2(4), 55-76. rossato s., fontana a., mozzi p. (2015) meta-analysis of a holocene 14 c database for the detection of paleohydrological crisis in the venetian-friulian plain (ne italy). catena, 130, 34-45. rossato s., martin s., ivy-ochs s., viganò a., vockenhuber c., rigo m., surian n., mozzi p. (2018) post-lgm catastrophic landslides in the dolomites: when, where and why. alpine and mediterranean quaternary, 31 (2), 239-242. rossato s., ivy-ochs s., martin s., viganò a., vockenhuber c., rigo m., monegato g., de zorzi m., surian n., campedel p., mozzi p. (2020) timing, drivers and impacts of the historic masiere di vedana rock avalanche (belluno dolomites, ne italy). nat. hazards earth syst. sci., 20, 2157-2174. doi: 10.5194/nhess-20-2157-2020 samia j., temme a., bregt a., wallinga j., guzzetti f., ardizzone f., rossi m. (2017) do landslides follow landslides? insights in path dependency from a multi -temporal landslide inventory, landslides, 14 (2), 547-558. schuster r.l., wieczorek g.f. (2002) landslide triggers and types. in: rybár j., stemberk j., wagner p. (eds) landslides: proceedings of the first european conference on landslides. taylor & francis, prague, 59-78. selli r., trevisan l., carloni c.g., mazzanti r., ciabatti m. (1964) la frana del vajont. giornale di geologia, xxxii(i), 1-154. semenza e. (2010) the story of vaiont told by the geologist who discovered the landslide. k-flash, ferrara. www.k-flash.it semenza e., ghirotti m. (2000) history of 1963 vaiont slide. the importance of the geological factors to recognise the ancient landslide. bull. eng. geol. env., 59, 87-97. spreafico m.c., francioni m., cervi f., stead d., bitelli g., ghirotti m., girelli v.a., lucente c.c., tini m.a., borgatti l. (2014) back analysis of the 2014 san leo landslide using combined terrestrial laser scanning and 3d distinct element modelling. rock mechanics and rock engineering, 49, 2235-2251. doi: 10.1007/s00603-015-0763-5 squinabol s. (1902) venti giorni sui monti bellunesi. tip. raffaello giusti, livorno, pp. 52. stead d., eberhardt e. (2013) understanding the mechanics of large landslides. italian journal of engineering geology and environment book series, 6, 85-112. stead d., wolter a. (2015) a critical review of rock slope failure mechanisms: the importance of structural geology. journal of structural geology, 74, 123. stefani c., fellin m.g., zattin m., zuffa g.g., dalmonte c., mancin n., zanferrari a. (2007) provenance and paleogeographic evolution in a multi-source foreland: the cenozoic venetian-friulian basin (ne italy). journal of sedimentary research, 77(11), 867 -887. strom a. (2006) morphology and internal structure of rockslides and rock avalanches: grounds and constraints for their modelling, in: landslides from massive rock slope failure, edited by: evans s.g., mugnozza g.s., strom a., hermanns r.l., nato sci. s., 49, 305-326. superchi l., floris m., ghirotti m., genevois r., jaboyedoff m., stead d. (2010) technical note: implementation of a geodatabase of published and unpublished data on the catastrophic vaiont landslide. nat hazards earth syst sci, 10, 865-873. takahashi t. (2001) process of occurrence, flow and deposition of viscous debris flow. in: seminara g., blondeaux p. (eds) river, coastal and estuarine morphodynamics. springer, berlin, 93-118. doi: 10.1007/978-3-662-04571-8_5 taramelli t. (1883) note alla carta geologica della provincia di belluno. ed. fusi, pavia, pp. 215. tarchi d., casagli n., fanti r., leva d.d., luzi g., pasuto a., pieraccini m., silvano s. (2002) landslide monitoring by using ground-based sar interferometry: an example of application to the tessina landslide in italy. engineering geology, 68, 15-30. travelletti j., delacourt c., allemand p., malet j.-p., schmittbuhl j., toussaint r., bastard m. (2012) correlation of multi-temporal ground-based optical images for landslide monitoring: application, potential and limitations. isprs journal of photogrammetry and remote sensing, 70, 39-55. doi: 10.1016/j.isprsjprs.2012.03.007 trigila a., iadanza c., guerrieri l. (2007) the iffi project (italian landslide inventory): methodology and results, in: guidelines for mapping areas at risk of landslides in europe, edited by: hervás, j., 15 227 from the past to the future: landslides in the piave valley 18. trigila a., iadanza c., bussettini m., lastoria b. (2018) dissesto idrogeologico in italia: pericolosità e indicatori di rischio. edizione 2018, ispra, rapporti 287/2018. van westen c.j., lulie getahun f. (2003) analyzing the evolution of the tessina landslide using aerial photographs and digital elevation models. geomorphology, 54(1-2), 77-89. venzo s. (1939) osservazioni geotettoniche e geomorfologiche sul rilevamento del foglio belluno. bollettino della società geologica italiana, 58, 433451. von wartburg j., ivy-ochs s., aaron j.b., martin s., leith k., rigo m., vockenhuber c., campedel p., viganò a. (2020) constraining the age and source area of the molveno landslide deposits in the brenta group, trentino dolomites (italy). frontiers in earth science, 8, 164. westoby m.j., brasington j., glasser n.f., hambrey m.j., reynolds j.m. (2012) structure-from-motion photogrammetry: a low-cost, effective tool for geoscience applications. geomorphology, 179, 300314. wieczorek g.f. (1996) landslide triggering mechanisms. in: turner a.k., schuster r.l. (eds) landslides: investigation and mitigation. transportation research board, national research council, special report, washington dc, 76-90. wirth s.b., glur l., gilli a., anselmetti f.s. (2013) holocene flood frequency across the central alps solar forcing and evidence for variations in north atlantic atmospheric circulation. quaternary science reviews, 80, 112-128. 228 wolter a., havaej m., zorzi l., stead d., clague j.j., ghirotti m., genevois r. (2013) exploration of the kinematics of the 1963 vajont slide, italy, using a numerical modelling toolbox. ital j eng geol environ, 6, 599-612. wolter a., stead d., clague j.j. (2014) a morphologic characterisation of the 1963 vajont slide, italy, using long-range terrestrial photogrammetry. geomorphology, 206, 147-164. wolter a., stead d., ward b.c., clague j.j., ghirotti m. (2016) engineering geomorphological characterisation of the vajont slide, italy, and a new interpretation of the chronology and evolution of the landslide. landslides, 13, 1067-1081. zanferrari a., masetti d., monegato g., poli m.e. (2013) geological map and explanatory notes of the geological map of italy at the scale 1:50.000: sheet 049 “gemona del friuli”. ispra servizio geologico d’italia regione autonoma friuli-venezia giulia, pp. 262. ms. received: july 3, 2020 revised: september 20, 2020 accepted: december 5, 2020 available online: december 20, 2020 rossato s. et al. available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 31 (2), 2018, 147 170 synthesis on the turin subsoil stratigraphy and hydrogeology (nw italy) m. gabriella forno 1 , domenico antonio de luca 1 , mauro bonasera 1 , arianna bucci 2 , franco gianotti 1 , manuela lasagna 1 , stefania lucchesi 1 , sebastiano pelizza 2 , fabrizio piana 3 , glenda taddia 2 1 dipartimento di scienze della terra, università di torino, torino, italy 2 dipartimento di ingegneria dell'ambiente, del territorio e delle infrastrutture, politecnico di torino, torino, italy 3 istituto di geoscienze e georisorse, cnr, torino, italy corresponding author: m.g. forno <gabriella.forno@unito.it> abstract: this work is a multidisciplinary synthesis of geological and hydrogeological researches on the subsoil of turin and suburbs, summarizing the existing previous studies and also using new data specially collected, aimed at bringing together the different aspects of the subsoil in a single contribution. the stratigraphic setting of the turin plain, as examined through numerous boreholes (wells, piezometers and geognostic drillings) shows an erosional surface essentially shaped on the fine villafranchian succession and locally on the pliocene and pre-pliocene sediments, on which the quaternary gravelly outwash and fluvial cover rests. this cover, which is mainly fed by the dora riparia river, is relatively thin (thickness between 5 and 57 m) and highly variable in terms of facies and cementation degreee. the most recent excavation activities are also taken into consideration, which locally allowed the direct observation of the shallow subsoil stratigraphy. the geological literature reports that the setting of turin subsoil is strictly conditioned by the quaternary uplift of turin hill. the structural causes of this geological evolution and its relationship with seismicity are here summarized. the stratigraphy of turin subsoil is also connected to the recent deviation of the po river, which flowed south of turin hill (through the southern slope of turin hill and the poirino plateau) during the middle-upper pleistocene and only recently develops at the nw foot of turin hill. a new reading of this po deviation as an overflow is made, based both on a re-examination of all the existing data and new collected data. the hydrogeological features of the turin subsoil are also reported, characterized by two superimposed main groundwater flow circuits, as well as the thermal regime of shallow groundwater and its geothermal potential. this work can help professional geologists for conducting geological, hydrogeological and geotechnical appraisals on turin and suburbs. it can also be useful to researchers to reconstruct the geological and hydrogeological features of the turin territory. keywords: subsoil stratigraphy, hydrogeology, fluvial deviation, turin, po plain 1. introduction this paper is a multidisciplinary synthesis of the researches on the subsoil of turin and suburbs, reporting both the numerous existing previous works on the stratigraphy and hydrogeology and new data specially collected, aimed at bringing together the different characteristics of the subsoil in a single contribution. in detail, this work includes the revision of the recent geological studies and maps through the observation of some deep excavations for the construction of the subway (line 1 of the metro), the underground railway pass and the intesa sanpaolo skyscraper, and of new boreholes and outcrops. the tectonic drivers of the recent geological evolution and its relationship with seismicity, strictly conditioned by the recent uplift of turin hill, are also reported. moreover the relationship of the stratigraphy of turin subsoil with the deviation of the po river, which flowed south of turin hill (through the southern slope of turin hill and the poirino plateau) during the middle-upper pleistocene and only recently develops at the nw foot of turin hill, is discussed. a new reading of this po deviation as an overflow is made, based both on a reexamination of all the existing geological data and the use of borehole data (wells, piezometers and geognostic drillings) located along the po river bed and into the poirino plateau. a revision of the existing data on the hydrogeological setting is at last reported, as well as the thermal regime of shallow groundwater and its geothermic potential. this work can help professional geologists for their geological, hydrogeological and geotechnical appraisals. it can also be useful to researchers to reconstruct the geological and hydrogeological features of the turin territory. 2. morphological setting turin and suburbs lie in the western sector of the po plain that here corresponds to a narrow band between the western alps and the turin hill. the city is built on the plain at the foot of the hill, where the po river flows (fig. 1). the suburbs display an asymmetric setting, west of the historical city. the morphology of turin reflects its geological https://doi.org/10.26382/amq.2018.10 148 setting. in more detail, the city shows a prevalent flat morphology at elevations between 275 m and 230 m a.s.l., with a low slope towards the e corresponding to wide alluvial fans (fig. 2). turin is built on upper pleistocene outwash sediments forming the fans linked to the alpine tributaries of the po river: the dora riparia river flowing at the susa valley outlet downstream of the rivoli-avigliana morainic amphitheatre and subordinately the stura di lanzo and sangone watercourses (festa et al., 2009a) (fig. 1). this sector is very flat and characterized only by local slope increases corresponding to fluvial scarps, that currently cut the alpine alluvial fans. the eastern edge of the city is instead built on lower (at elevation between 224-210 m a.s.l.) and narrow (with width up to 500 m) fluvial terraces along the two banks of the current po river; the terraces gently dip towards the ne and are made of holocene fluvial sediments of this watercourse. the large extension of lateral fans formed by outfig. 1 location of turin and suburbs (urban area in yellow) between the western alps and the turin hill, showing an asymmetric position along the po river. the minor extension of the fluvial plain (approximately 17 km) is near moncalieri. the rivoli-avigliana morainic amphitheatre (rama, west of turin) is also mapped. forno m.g. et al. 149 distribution of its terraced quaternary fluvial succession that lies on its northern (barbero et al., 2007), northwestern (forno & lucchesi, 2005) and southern sides (forno & lucchesi, 2016). the turin hill anticline axis plunges to the sw, below the turin plain, while to the east it is displaced by the rio freddo deformation zone (rfdz), wash sediments connected to the po tributaries, on which turin and suburbs are built, suggests that these fans almost occupied the entire plain area, up to the foot of turin hill. the fluvial sediments linked to the po river constitute only a narrow band along this current watercourse, which clearly cuts the lateral fans. this evident intersection between the fluvial po sediments and the deposits of its tributaries is the result of an important fluvial deviation that affected the po river in recent times (see section 5) (carraro et al., 1995; carraro, 2012). finally, the hilly part of the city (at elevation between 715 and 230 m a.s.l.) corresponds to the western and northwestern slopes of turin hill. it is prevalently built on terraced surfaces in which thin fluvial sediments directly rest on tertiary marine successions (see section 4). 3. geological setting the features of turin plain, located near to the turin hill, suggest that it is connected with the hilly structure. in detail, the turin hill successions continue in the subsoil of turin buried by quaternary deposits. the turin hill is the surface expression of a ne-sw anticline formed during the miocene (festa et al., 2009b) at the top of the main padane thrust front (sensu pieri & groppi, 1981). this antiformal ridge uplifted in the quaternary, as indicated by the fig. 2 gently eastward sloping morphology of turin, which has been built on the wide outwash fan supplied by the susa valley, drained by the dora riparia river, as seen from turin hill. fig. 3 the hilly slope facing turin shows flat surfaces, corresponding to a succession of fluvial terraces (arrows) shaped by the paleo dora and paleo stura rivers. turin (240-230 m a.s.l.) is located in the plain, covered by fog. monviso (3841 m) is the highest peak. the superga church (s) (670 m a.s.l.) is located on the watershed of turin hill. synthesis on the turin subsoil stratigraphy and hydrogeology 150 fig. 4 a) the fluvial terraces relating to the different time intervals are represented by the different colored bands. ancient trend of the dora riparia and stura di lanzo rivers (paleo dora and paleo stura), showing opposite flow directions (towards the south and ne, respectively), are preserved on the western and northwestern slopes of turin hill for the high and more ancient terraces (middle pleistocene). the flow direction of these rivers is the same towards ne for the lower and more recent terraces (upper pleistocene). ancient trends of po river (paleo po) are preserved in the southern slopes of turin hill, flowing towards the east. the more weathered oldest terraces are preserved near the hilly watershed and the more recent ones develop progressively to the northwest for paleo dora and paleo stura and to south for paleo po. b) legend of fig. 4a in the front page (modified from forno & lucchesi, 2005; 2016). a forno m.g. et al. which separates it from the adjoining monferrato domain (piana & polino, 1995). immediately southward, the torrente traversola deformation zone (ttdz) cuts the asti syncline separating the poirino plateau from the asti reliefs (gattiglio et al., 2015) (fig. 1). the stratigraphic succession that forms the turin hill bedrock is referred to the “tertiary piemonte basin, tpb” (gelati & gnaccolini, 1982; biella et al., 1997), a paleogeographic domain where an oligocene to messinian continuous sedimentary succession deposited. the sedimentary successions of the tpb can be well correlated through different geostructural domains of southern piemonte, among which are the turin hill and the adjoining monferrato hill system. these mainly terrigenous successions (dela pierre et al., 2003; festa et al., 2009a) were deposited in a synorogenic basin placed over the suture zone between the western ligurian realm and the exhumed eocene hp/lt metamorphic complexes of the western and ligurian alps (castellarin, 1994; falletti et al., 1995; piana & polino, 1995; piana, 2000; mosca et al., 2010). although strongly controlled by synorogenic tectonics, the tpb successions were deposited in a single upper eocenemiocene basin, affected by coeval tectono-depositional events marked by unconformities, which are physically traceable at a regional scale (piana et al., 2017). these successions consist of two late eocene to early miocene terrigenous synthems (conglomerates, sandstones and marls) followed by a burdigalian carbonate synthem and two other terrigenous synthems (langhian to tortonian) followed in their turn by messinian evaporites. the above described tpb units are covered by a pliocene muddy-sandy succession that in turin hill crops out mostly in the southern flank of the anticline and which can be subdivided into three main lithostratigraphic units: from base to top, the argille azzurre formation (from upper epibathyal to circalittoral marine clay), the asti sand (circalittoral and littoral marine sand) 151 synthesis on the turin subsoil stratigraphy and hydrogeology 152 fig. 5 the superga ridge preserves three terraces (arrows at 670 m, 500 m and 350 m a.s.l.) high above the turin plain (average 230 m a.s.l.). this setting indicates that the paleo stura flowed through an alluvial plain, progressively deformed and uplifted into the slope of turin hill. fig. 6 the southern slope of the turin hill showing a flat surface in the foreground (arrows) represents the ancient trend of the po river flowing towards the east. the higher sector of turin hill is on the top right on the picture. forno m.g. et al. variable from 2,5 yr to 10 yr) that developed on top of the different terraced fluvial sediments suggest to refer them to a relatively extended period of time that spans a large part of the middle and upper pleistocene. moreover, most of the fluvial terraces (from 15 to 4 units in fig. 4) are discontinuously covered by the aeolian loess referred to the last glacial maximum (lgm) (forno, 1990); therefore, their age is older than 27.5-20 ka bp, according to the dating of the nearby rivoli-avigliana morainic amphitheatre (ivy-ochs et al., 2018). a few of them, without the loess cover, are instead more recent (post-lgm). the correlation of various terraces at a higher altitude in turin hill (above 380 m a.s.l.) indicates the flow of an ancient path of the dora riparia river towards the s (paleo dora) through the current western slope (11w5w units in fig. 4) and an ancient path towards the ne of the stura di lanzo (paleo stura) through the current northwestern slope (from 13n to 6n units in fig. 4) (forno & lucchesi, 2005). data on the heavy minerals of the fluvial sediments forming the sequence of terraces indicates a provenance from the ancient basins of the dora riparia and stura di lanzo, respectively, confirming this morphological setting (vezzoli et al., 2010). the correlation of the fluvial terraces at lower altiand the villafranchian succession (deltaic and continental deposits). all these units crop out on the turin hill anticline and continue below the turin plain (fig. 1). 4. geological reconstruction of turin hill a reconstruction of the quaternary geological succession of the neighbouring turin hill is necessary to understand the recent geological evolution that involves the turin plain. flat surfaces are preserved on the northwestern and western slopes of turin hill, weakly sloping towards nw or w, corresponding to a succession of fifteen fluvial terraces (fig. 3). this succession develops in a wide range of altitudes between approximately 700 m a.s.l. in the main watershed and 240 m on the lower terraces (forno & lucchesi, 2005). we can also clearly recognize these terraces in ancient iconography, before the urbanization of the hilly areas. consequently, they are not anthropogenic, nor related to the recent urbanization of the hilly area. silty and sandy fluvial sediments form the different terraced surfaces, studied through geologic survey and well-log stratigraphy (forno et al., 2002). the fluvial deposits are thin (2-8 m) and cover the cenozoic (eocene-pliocene) marine succession of turin hill. the various soils (with hue color index of the b horizon 153 fig. 7 the fluvial succession mapped in turin hill proves that in the upper pleistocene the hydrographic pattern was formed by a paleo dora river, that flowed on the western and northwestern slopes of turin hill, and a paleo po river that flowed through its southern side (white arrows). the neo po river develops during the late upper pleistocene, through an overflow phenomenon, flowing toward north (blue arrow). bth: buried turin hill; ptf: padane thrust front; ttdz: t. traversola deformation zone; rfdz: rio freddo deformation zone; ltdz: colle del lys-trana deformation zone. the peaty sediments connected to the paleo po river and described in the moncalieri-la loggia quarries by tropeano (1987) (q), observed in an ancient outcrop at la loggia (p) (fig. 9) and drilled in a recent borehole at poirino (b) (fig. 10) are also reported. synthesis on the turin subsoil stratigraphy and hydrogeology tudes of turin hill (below 380 m) indicates that a single river (paleo dora + paleo stura) flowing towards the ne subsequently developed along the current western and northwestern slopes (from 4 to 1 units in fig. 4), which is also confirmed by the composition of heavy minerals of sediments. the elevation of these terraces, which are hanging with respect to the surrounding plain at up to several hundred metres (up to 450 m at superga), suggests that they have been significantly raised and deformed by the recent geodynamic evolution of turin hill (boano et al., 2004) (fig. 5). this terraced succession is referred to ancient flat morphologies on which the alpine fans leaned against the uplifting turin hill, before the recent definition of the current po river (neo po). a progressive incorporation of these terraces into the hillside due to the continuous uplifting of turin hill has been reconstructed, suggesting that they formed in the original alluvial plain and only later became part of the hill. consequently, despite their proximity to the current po river, these terraces are not linked to the paleo po (vezzoli et al., 2010). in contrast, the wide relicts of the fluvial po plain preserved on the southern slope of turin hill (fig. 6) represent the main evidence that during the pleistocene the paleo po flowed eastward in this area (from 16 to 4s units in fig. 4) and not in the current po plain north of turin hill (forno & lucchesi, 2016). these relicts preserved in the southern slope are mainly constituted by sandy silty sediments, with rare gravelly lenses, suggesting a deposition in a flat meandering river floodplain. the petrography of the fluvial pebbles (essentially formed by metamorphic rocks such as serpentinite, metagabbro, prasinite, eclogite, quartzite, and peridotite) is consistent with a paleo po provenance and a flow 154 fig. 8 the alternating gravel and fine-grained sediments with peaty layers (black) deposited by the paleo po river (a) during the upper pleistocene suggest the formation of marshes in the plain south of turin. the gravel deposited by the paleo dora river (b) indicates the aggradation of the dora riparia outwash fan. a low watershed developed between the two areas, currently buried. subsequently, the shaping of an evident erosional surface (s) and the neo po sediments (c) deposited in the late upper pleistocene indicate the formation of the current po river through an outwash phenomenon. fig. 9 the peaty sediments (asterisk) connected to the paleo po river are buried by the sandy silt deposited by the neo po river (outcrop south of turin along the ring road at la loggia, near cascina revignano, now covered by walls). forno m.g. et al. 155 tab.1 radiocarbon ages for the fluvial succession of the paleo po (1-9) and the neo po (10-17). twenty dating were provided by woody remains and peaty layers coming from seventeen different sites (nine quarries, three boreholes, one dig and four natural outcrops) of the plain south of turin. conventional ages (see references in the table) are all calibrated or re-calibrated and listed in chronological order. synthesis on the turin subsoil stratigraphy and hydrogeology direction towards east, south of turin hill (compagnoni & forno, 1992). the more ancient fluvial terraces, which preserve well developed soils, are placed in the northern sector near the current watershed at 715-500 m a.s.l., and the more recent elements, which show poorly developed soils, are towards the south in the poirino plateau at 280-240 m a.s.l. (fig. 4). the scarce weathering of the more recent deposits (color 10 yr 4/6 of the b horizon) suggests that the paleo po flowing through the southern slope of turin hill and the poirino plateau can be referred to a large part of the upper pleistocene, confirming the recent setting of the po in the current position. 5. the turin plain as result of fluvial deviation the distribution of the fluvial terraces on the slopes of turin hill proves that the watercourses progressively migrated during the middle and upper pleistocene, towards the nw for the paleo dora and towards the s for the paleo po, moving away from the hilly watershed (fig. 7). this shifting of the two rivers was promoted by the progressive tectonic evolution of turin hill (see section 7). the proximity of the paleo po bed with the paleo dora one suggests that a low and thin watershed separated the two rivers, connected both to the buried sw continuation of turin hill in the subsoil (bth in fig. 7) and the aggradation of the proglacial fan of the rivoliavigliana amphitheatre in the turin plain during the acmes of the glaciations. the fine-grained sediments with peaty layers with minor gravel, sedimented by the paleo po (a in fig. 8), that are encountered in some boreholes and are also visible in quarries (moncalieri-la loggia, q in fig. 7), record the formation of marshes in the plain south of turin (fig. 9). this evidence suggests a difficult flow of the paleo po towards the east that was essentially caused by the uplift of the poirino plateau linked to evolution of the t. traversola deformation zone (ttdz) (fig. 1) (gattiglio et al., 2015). a recent geognostic borehole observed near poirino, south of turin hill (fig. 10), evidences thin levels of grey sediments, with a peaty component, to divide the paleo po sediments (6.70-9.75 m) on respect to the overlaying sediments connected to the banna river (above 6.70 m), that currently develops in the poirino plateau. these levels furtherly highlight the formation of marshes. the scanty weathering and the fossil remains of “wurmian” mammals found in the sediments of the paleo po river including mammuthus primigenius (la loggia), megaloceros giganteus (la loggia, escosa quarry), and bison priscus (moncalieri, molinello 156 <<< fig. 10 log of a poirino geognostic drilling (via pessione). the thin organic sediments between 8.00 and 6.70 m are connected with the developing of marches to divide the paleo po river sediments (light blue, between 9.75 and 6.70 m) from the banna river sediments (yellow, above 6.70 m). the villafranchian succession is observed in the lower stretch of the log (green, under 9.75 m) (modified from a citiemme log). forno m.g. et al. quarry) (tropeano, 1987) and the more ancient radiocarbon data of peaty layers (from >44 ka to 27.9 ka cal bp, 1-7 in tab. 1) indicates that the ancient trend of the po river (paleo po) persisted until the late upper pleistocene. subsequently, the progressive paleo po deposition buried the low watershed separating the paleo po sediments (a in fig. 8) from the paleo dora ones (b in fig. 8), and the first river consequently experienced a lateral spillover with deviation towards the north, forming the neo po (c in fig. 8). the current po probably invaded the band shaped by the paleo dora river, giving rise to 157 fig. 11 the more extended terrace in the foreground (vallere terrace, v), connected to the neo po, is entrenched between the paleo dora riparia fluvial terraces (moncalieri castle terrace and moncalieri church terrace, arrows) and the paleo dora alluvial fan of turin (on the right outside the photo). fig. 12 geological cross section of the subsoil of turin. in most of the turin plain the outwash sediments of paleodora riparia river cover the villafranchian succession. at the foot of the turin hill the fluvial sediments of the current po river lie on the miocene and pliocene marine sediments (modified from lucchesi, 2001). synthesis on the turin subsoil stratigraphy and hydrogeology an overflow phenomenon. this event could only have taken place after the end of the aggradation of the dora riparia proglacial fan, i.e. likely not before the early lateglacial. consequently to this overflow event, during the lateglacial the po river eroded the paleo po and the paleo dora successions forming an evident erosional surface (s in fig. 8). the radiometric ages referred to the neo po river sediments are from 6.8 ka cal bp (10 in tab. 1) to a series of historical ages (15 -17 in tab. 1). the observation that the neo po did not shape a new bed necessarily modifies the interpretation of this phenomenon, here indicated as overflow and, instead, reported as a diversion in the previous geological literature (carraro et al., 1995). 158 fig. 14 the thin outwash sediments, in the subsoil of turin and suburbs, generally rest on the villafranchian succession. locally, at the foot of the turin hill, they rest directly on the pliocene or miocene marine succession, to form an erosional buried surface. the black and white numbers respectively indicate the topographic quote and the quote of the base of the outwash sediments. the logs of the boreholes evidence the thickness of outwash and fluvial sediments from a minimum of 5 metres (moncalieri) to a maximum of 57 m (collegno). location of subway (m: line 1 of the metro, dotted grey line; see fig. 15) and intesa sanpaolo skyscraper excavations (s: red square; see fig. 16), outcrop of giordano bruno street (g; see fig. 17) and botanic garden borehole (b; see fig. 18) are reported (modified from festa et al., 2009b). fig. 13 the outwash sediments of the paleodora riparia river, referred to middle-upper pleistocene, rest on a wide erosional surface shaped on the villafranchian succession and locally on the asti sand or argille azzurre formation (modified from forno & lucchesi, 2014). forno m.g. et al. the vallere terrace, on the left side of the po river near moncalieri approximately 4 m above the current river bed, represents the evidence of the first path of the neo po. this recent terrace appears entrenched into the terraces connected to the paleo dora river (fig. 11). the very weak weathering of the sediments connected to the current po river suggests that this phenomenon occurred in the late pleistocene/holocene. in detail, the neo po deepened the paleo dora outwash fan (below the moncalieri castle and the moncalieri church terraces) also depositing the sand of the vallere terrace (fig. 11). some other lower terraces formed along the po river, hanging only 2-3 metres over the current riverbed, also suggesting that the current watercourse is characterized by fluvial deepening consequent the new basic level (carraro & lucchesi, 2004). 6. stratigraphy of the shallow subsoil the recent deviation of the po river at the foot of turin hill, along the padane thrust front (ptf) (fig. 7), influences the stratigraphy of the shallow subsoil of turin and suburbs (section 5). the stratigraphic reconstruction is based on local outcrops (anthropic excavations or river incisions) and a large number of borehole logs (wells, piezometers and geognostic drillings) carried out during the last decades. they are available in archives of the regional environmental protection agency (arpa) and of the earth sciences department of turin university (lucchesi, 2001) as well as in the carg project database (festa et al., 2009b) (fig. 12). the shallowest subsoil of turin and suburbs is mainly constituted by thin outwash sediments referred to the paleo dora with the contribution of the paleo stura (middle and upper pleistocene), that cover the villafranchian succession (piacenzian and calabrian). the northeastern sector of the city (between turin and settimo torinese) shows instead outwash sediments, with thickness of 10-27 m, that rest on the marine succession (asti sand or argille azzurre formation) (fig. 13). the villafranchian succession is essentially formed by alternating silt and fine gravel, referred to the lower complex (piacenzian), that are related to a deltaic environment (forno et al., 2015). these sediments appear as overconsolidated and are very fractured (forno et al., 2009). the gravelly and silty sediments referred to the upper complex (calabrian) and related to a fluvial environment are instead only locally preserved. the erosional surface that divides the villafranchian succession from the outwash pleistocene sediments, with regional extent, is likely the result of many erosional episodes carried out by the alpine watercourses that have determined the almost total removal of the upper complex of the villafranchian succession (fig. 12) (lucchesi, 2001; forno et al., 2009). the overlying pleistocene outwash sediments show a reduced thickness, generally between 57 m, at the western alpine foot, and 9 m below turin, at the eastern edge of the plain (fig. 14). the maximum thickness along the dora riparia river (57 m at collegno and 45 m at beinasco) suggests a main supply from this basin, connected to the proglacial system of the rivoliavigliana amphitheatre (fig. 1). these sediments are characterized by sandy gravel with minor lenses of silty sand and clayey silt (fig. 15). several remarkable excavations have been carried out in the shallow subsoil of turin. the ancient extensive tunnels of the cittadella fortress have involved the subsoil of the center of turin in the past (beginning of 18th century ad) and are still partly visible. the sub 159 fig. 15 a) main recent excavations in the subsoil of turin: 1) subway (line 1 of the metro, 15 km); 2) underground railway pass (12 km); 3) intesa sanpaolo skyscraper. b) cross section along the subway involving the variously cemented dora riparia river outwash sediments (modified from a geodata sketch). synthesis on the turin subsoil stratigraphy and hydrogeology way (line 1 of the metro), the underground railway pass and a local deep excavation to build the foundations of the intesa sanpaolo skyscraper have been realized in the last decades. these excavations essentially involve the gravelly surficial outwash sediments, locally intercepting the underlying villafranchian succession (pelizza, 2010; 2014). the excavation activity was strictly conditioned both by the heterogeneity of the outwash sediments, formed in detail by alternating sandy gravel with boulders and silty sand, and by their degree of cementation. this cementation appears particularly remarkable along the dora riparia bed, suggesting a carbonatic contribution by this river supplied by a cathment basin rich in carbonatic rocks. more specifically, the approximately 20 m deep excavation of the subway in the northern sector of the turin subsoil encountered a strong variability of cementation of gravel layers (fig. 15) (de rienzo et al., 2009). the excavation involved the villafranchian succession only on the southern stretch (between the porta susa and porta nuova stations). the excavation of the underground railway pass in the southeastern sector of the turin subsoil, instead, sustained problems essentially caused by a very shallow water table, as also evidenced by the hydrogeological reconstruction (see fig. 22c). the last excavation (intesa sanpaolo skyscraper), which was over 40 m deep, involves the alternating essentially gravelly and sandy outwash sediments, intercepting the top of the underlying clayey villafranchian succession (fig. 16). boulders of considerable size (approximately 1 m in diameter) were found within the outwash deposits, also forming a level (32-33 m of depth) probably connected with glacial route phenomena. moreover, a 15 m deep building excavation within the city of turin (g in fig. 14) showed a sequence formed by sandy gravelly outwash sediments, with a cover of silty sand (fig. 17). the petrography of the pebbles (essentially metamorphic rocks such as serpentinite, metagabbro, prasinite, peridotite, amphibolite, quartzite, gneiss, graphitic schist and micaschist with rare marble and calcschist) indicates a feed by the paleo dora (col giansesco unit, in festa et al., 2009b). these sediments show a scarce weathering (fig. 17), evidenced by fresh pebbles and yellowish brown colour of soil (10 yr 5/6 of the b horizon), suggesting that they refer to the late upper pleistocene. thin fluvial sediments referred to the neo po (thickness between 13 and 21 m) are present only in the eastern sector of the city at the foot of turin hill, where they directly rest on a buried erosional surface molded in the pliocene or pre-pliocene marine succession by the fluvial erosion (forno & lucchesi, 2014) (fig. 12; see green in fig. 22a). a recent geophysical survey confirms the weak depth (3-20 m) of the marine sediments along the current po river bed (sambuelli et al., 2017). in detail, the recently specially drilled 26 m deep piezometer in the botanic garden lying on a terrace at the left of the po river (b in fig. 14), shows a 21 m tick body of fluvial deposits consisting of alternating sandy gravel and silty sand linked to the neo po (fig. 18). the clasts of the gravel layers are centimetric to decimetric in size, characterized by high roundness and essentially formed by quartzite and conglomeratic quartzite (“anagenite” auct.), serpentinite, prasinite, peridotite, gneiss, marble, dolomitic marble, and meta-pegmatite, according to the present po basin also with the contribution of the paleo tanaro river as tributary. consequently, the known overflow of the tanaro river (from the ancient northward flow to join the paleo po river south of turin, to the present flow towards ne across 160 fig. 16 cross section of the excavation of the intesa sanpaolo skyscraper (s in fig. 14) essentially involving the outwash sandy gravelly sediments (yellow), with a boulder level, that lie on the silty villafranchian succession (green). altitude is referred as m a.s.l. fig. 17 an approximately 15 m deep recent building excavation within turin (giordano bruno street, g in fig. 14) shows the sequence formed by gravelly and sandy outwash sediments, supplied by the dora riparia river during the upper pleistocene. forno m.g. et al. the asti reliefs; carraro et al., 1995) only occurred later than the po river overflow. the sand layers are essentially constituted by fine sand, with intercalations of silt. the fluvial sequence of the neo po shows absence of weathering with fresh pebbles and pale brown color of the matrix (10yr 6/3 of the b horizon), suggesting a late upper pleistocene or holocene age, younger than the paleo po sediments south of turin containing peaty layers dated 38-28 ka cal bp (see section 4). the presence of pliocene sediments at the base of the borehole implied a local revision of the map of turin (fig. 14), originally reporting the miocene succession in the sector near the po river (festa et al., 2009b). 7. recent tectonic evolution since the middle miocene, the n-verging padane thrust front (ptf in fig. 1) developed and the tpb consequently evolved as a wide thrust top basin (mosca et al., 2010), causing the folding of the turin hill and its tilting and overthrusting (together with the adjoining monferrato domain) onto the turin plain foredeep, which lasted until the late pliocene. in this time span, at the rear of the ptf, a new n-verging thrust (saluzzo thrust, bigi et al., 1990, mosca et al., 2010) displaced the tpb succession, while two major depocenters (the savigliano and the alessandria subsiding basins) developed south of the turin plain, where some ne-sw to e-w and n-s normal and strike-slip faults also evolved (boano & forno, 1999; festa et al., 2009b). seismotectonic analyses do not show clear evidence of current activity for the ptf at the edge of monferrato and turin hill (perrone et al., 2013). these data confirm the gradual reduction of shortening rates, as evidenced by gps data (devoti et al., 2011), from the eastern to the western po plain. nevertheless, the eastward decrease of the shortening rates along the ptf, does not necessarily imply a complete deactivation of the ptf, but rather it could suggest its quiescence (michetti et al., 2012). evidence of current tectonic mobility are reported, for the turin area, by morelli et al. (2011) and perrone et al. (2013) on the basis of statistical analysis of psinsar data (fig. 19), suggesting present differential crustal movements of the inner part of the cottian alps with respect to the buried turin hill western prolongation but, conversely, reporting scarce vertical movements across the ptf. if poor uplifting rates of the buried turin hill are inferred not only for present, but also for the late pleistocene and holocene, the po overflow along n-s direction in the turin plain could more easily be justified, as previously discussed in section 5. these rates appear in contrast with the relevant uplifting rates recorded at the eastern termination of the turin hill-monferrato system, as reported by arca & beretta (1985). 161 <<< fig. 18 the log of the recently drilled borehole of botanic garden of the turin university (b in fig. 14) shows the alternating gravelly and sandy po river sediments (21 m thick) that cover the clayey silt and marl of the pliocene succession (argille azzurre formation). a 2-m thick anthropogenic body is observed at the top of the stratigraphic succession. synthesis on the turin subsoil stratigraphy and hydrogeology 8. seismic activity despite turin being assigned to the 4th seismic zone, the lowest in the national seismic classification, the seismic potential of the city of turin is commonly associated with two main districts: the northern cottian alps and the borbera-grue (north-western apennines) seismic zones (fubelli et al., 2018). these zones are connected northwards to vallese and converge southwards to cuneese areas. the related earthquake epicentres appear to have a great dispersion towards the french alpine side along the southern piedmont reliefs. the regional seismic network annually detects hundreds of earthquakes with epicentres located in the piedmont (e.g., the susa valley, lanzo valley and langhe) or in surrounding areas. generally, the population does not perceive them. next to epicentral areas, there are about ten perceived earthquakes per year. on average, one event per year can possibly cause some significant effects, even at longer distances, where they would be generally slight. the last significant earthquake occurred on 25 july 2011 near the sangone valley and chisola valley (4.4 mw). more than one hundred historical earthquakes, with estimated moment magnitude between 4.5 and 6 occurred during the last millennium (pignone et al., 2013) (fig. 20). the data appears to be underestimated due to: i) the lack of details in the available historical catalogues and ii) the almost complete absence of information concerning the seismogenic sources responsible for the main events occurred in the two areas: the 1808 pinerolo (mw 5.64) and the 1828 tortona (mw 5.72) earthquakes. greater magnitude earthquakes, that are able to produce appreciable effects even in turin, have occurred relatively close to the borders of the piedmont; in particular, the event of february 23, 1887, near the western ligurian coast was less than 50 km from the piedmont border and had an estimated magnitude of 7.0 mw. 9. hydrogeology of the subsoil the stratigraphy of the turin subsoil influences its hydrogeology. five hydrogeological complexes superimposed on top of each other can be identified in the turin shallow subsoil (fig. 21) (bove et al., 2005; de luca et al., 2014; de luca & ossella, 2014). the complex of marine pre-pliocene deposits of turin hill (eocenepliocene) located at the base of the sedimentary succession comprises clay, marl, silt, limestone, sandstone and chalk (festa et al., 2009a). they are generally compact rocks, constituting a basically impermeable me 162 fig. 19 distribution and statistical hot-spot analysis of ps-insar data related to the turin area. a) ps spatial distribution that represents the spatial variability of ps-insar velocity. hot-spot was calculated with d=5 km; red and blue points represent respectively high and low z (gi)* values in relation to the expected values; b) iso-kinematic map based on ps-insar data distribution expressed in high (red) and low (blue) values of z (gi)*. grey dashed line represents the iso-kinematic boundary (see morelli et al., 2011 for further explanation) (from perrone et al., 2013). forno m.g. et al. fig. 20 a focus on the piedmont region extracted from the seismicity map of italy, related to 2000-2012 period (from pignone et al., 2013). fig. 21 conceptual hydrogeological model of the turin area, showing deep aquifers, conditioned by the buried hilly structure, and a surficial aquifer both flowing from the alps towards east. synthesis on the turin subsoil stratigraphy and hydrogeology 163 dium, or are locally permeable by fractures (de luca et al., 2015). two facies can be recognized in the overlying complex of pliocene marine deposits: the argille azzurre formation consists of scarcely permeable silt and clay, while the asti sand hosts moderate productive aquifers, even if the frequent presence of a fine matrix can limit productivity. the villafranchian complex (piacenzian and calabrian) constitutes the substrate of the middle -upper pleistocene cover in most of the area. it consists of alternating sandy gravel (locally, it is possible to identify levels of predominant sand or predominant gravel) and silty clay and sometimes peaty silt. the alternating coarse permeable deposits with impermeable or semipermeable fine deposits generates a multi-aquifer system in which confined or semiconfined aquifers are located in coarse-grained levels, separated by low permeability levels. this multilayered aquifer represents the most exploited groundwater system of the turin area, in particular for human consumption, but also subordinately for industrial uses. the glacial complex (middle-upper pleistocene) exclusively forms the rivoli avigliana morainic amphitheatre. these sediments have extremely heterogeneous grain size and appear on the whole to be scarcely permeable. indeed, the abundant fine-grained matrix reduces the permeability, allowing the development of generally unconfined small aquifers. the outwash and fluvial complex (middle pleistocene-holocene) consists of gravel and sandy gravel with boulders, with coarser texture towards the west (castagna et al., 2015a; 2015b). the base of this hydrogeological complex has a higher slope in the western part of the studied area (near the alpine edge), while the slope progressively decreases in the eastern area. some depressions in the base, e.g., in the area between alpignano, rivoli and rivaltaorbassano, could be related to paleochannels and this morphology influences the groundwater flow (fig. 22a). a shallow unconfined aquifer is hosted in this complex and is characterized by high productivity, but scarce quality mostly due to industrial contamination in town and agricultural pollutants in rural areas (lasagna et al., 2015; 2016b; lasagna & de luca, 2017; martinelli et al., 2018). groundwater flow in the shallow aquifer is directed towards the east, towards the current po river which represents the main gaining element of the whole turin plain (fig. 22b) (lasagna et al., 2016a). the piezometric lines range from a maximum of 360 a.s.l. m in the west (rivoli) to a minimum of 205 a.s.l. m in the northeast (near the po river). the depth of the water table ranges between 50 metres in the perialpine sector and 5 m in the sector closest to turin hill and the areas surrounding the main fig. 22 a) map of the base of the outwash and fluvial complex (1-highest altitude zones; 2-lowest altitude zone; 3paleochannels; 4contour lines of the complex base in a.s.l. m; 5buried erosional surface); b) piezometric map of the shallow unconfined aquifer (january 2000) (1-isopiezometric lines in a.s.l. m; 2-flow lines); c) map of depths to the groundwater table (january 2000). 164 forno m.g. et al. rivers (fig. 22c) (debernardi et al., 2008). the hydrogeological conceptual model has been developed on the basis of the stratigraphic reconstruction and the hydrogeological features of the complexes. it describes two main groundwater flow circuits: a shallow flow system and a deep flow system (fig. 21). the shallow flow system is close to the topographic surface. groundwater flows in the shallow unconfined aquifer and it is hosted by the outwash and fluvial complex. the deep flow system is located at greater depth. deep groundwater flows in the villafranchian complex and in the complex of pliocene marine deposits. these aquifers can present different degrees of groundwater confinement according to the presence of impermeable or semipermeable layers. the groundwater recharge of deep aquifers occurs in the foothill sector, in which a highest percentage of coarse deposits is identified than in the surrounding areas. this area can be described as an undifferentiated aquifer. moving eastwards, the fine-grained levels gradually increase and thicken; this produces a growing confinement of groundwater in the interposed coarse layers. 10. thermal regime of shallow groundwater concerning the geothermal applications, the groundwater temperatures of shallow aquifer can be assumed to be relatively constant throughout the year if compared to the wider seasonal air oscillation recorded in a medium temperate climate of continental europe. the thermal features of the shallow aquifer, in combination with the high productivity and the legal protection of deeper aquifers contributes to create favourable conditions for the large-scale diffusion of groundwatercoupled heat pumps (gwhps). the study of the thermal regime of shallow groundwater in the turin plain is of primary importance to define the potential exploitation with geothermal heat fig. 23 groundwater temperature values of shallow aquifer in turin area (spring 2014). synthesis on the turin subsoil stratigraphy and hydrogeology 165 pumps (gshps) in an area where the large heating/ cooling demand has driven a new interest in gshps. studies carried out in 2014 and 2016 (barbero et al., 2016; bucci et al., 2017) revealed that the strongest vertical variability of groundwater temperature is found within 10-20 m below ground surface. in spring, deeper temperatures are higher than shallow temperatures, while in autumn the trend is reversed. these variations are connected with the heating and cooling cycles of the ground surface due to seasonal air temperature fluctuations propagating into the aquifer. the groundwater temperature below the zone of seasonal effect, averaged from spring and autumn values extracted from bucci et al. (2017), is 14.1 °c. the seasonal variations in the upper portion of the aquifer reach 8 °c and are inversely proportional to groundwater table depth. indeed, the seasonal amplitude reduction with increasing depths means that the vadose zone plays a major role in damping the oscillations, according to similar studies by burns et al. (2016). the temperature increases from the foothill sectors close to the alps towards the central po plain are driven by the progressive warming along the flow path (fig. 23). in the city of turin’s aquifer temperatures are 0.6 ÷1.6 °c higher than in rural sectors. this groundwater warming is linked to the urban heat island effect, which is mainly driven by the typical artificial land use (i.e., benz et al., 2015). sparse warmer outliers (16-20 °c) are in some cases connected to documented point heat sources, such as gshp systems, industrial districts and landfills. for instance, groundwater in some wells 10 km south of turin city (25 to 30-m deep) is overheated by heat transported from the polluted sector, where exothermic reactions caused by organic matter degradation likely occur (the site has methane burners), and by the asphalted road that, according to previous studies (i.e., taylor & stefan, 2009), can increase temperatures up to 3 to 4 °c. 11. geothermic use of the subsoil geothermal heat pumps represent an interesting technology that is expected to contribute significantly to the reduction of primary energy use for heating and cooling, in particular in urban contexts such as in turin. the replacement of conventional heating systems such as boilers, with heat pump systems allows the delocalization of emissions of micropollutants from urban centres to the sites in which thermal power stations are operating. this also enhances emission monitoring and control. in 2017, turin has had high levels of co2 emissions dangerous to human health, and for several days the limits have been exceeded with respect to those allowed by law. the use of distributed production systems based on the use of renewable sources then also reduces co2 emissions (lo russo et al., 2011). urban areas such as turin have environmental features that may influence the development of lowenthalpy geothermal systems and the choice of the most suitable type of system to be installed (lo russo & taddia, 2009; baccino et al., 2010). in this general context, the increasing implementation in several areas of the turin urban city of the open-loop groundwater heat pump technology (a particular technology of geothermal heat pumps that disharge into the aquifer for cooling and heating buildings) could potentially cause, even in the short term, a significant environmental impact associated with thermal interference with groundwater, particularly in the shallow aquifers. the discharge of water at different temperatures compared to baseline values (warmer in summer and colder in winter) poses several problems in relation to the potential functionality of many existing groundwater uses (drinking water wells, agricultural and industrial aims). in addition, cases may occur of interference between systems, especially in the densely urbanized places. this means that the alteration of the temperature of the groundwater determined by a plant may affect the installations located downstream, with significant alterations to the performances of the systems themselves. in particular, compared to countryside areas or urban areas with small population densities, there are potential issues that need to be considered in the analysis: a) extensive use of the subsoil; b) contamination of groundwater; c) interference between facilities; d) authorization procedures and legal constraints; e) competition with alternative energy systems. in particular the turin territory is well suited to the analysis of issues related to the impact of heat pumps on groundwater. in this area there is a significant number of installations of medium and large size groundwater heat pumps and this number is still increasing. among these installations, it is possible to mention the politecnico di torino, the egyptian museum, the palace of the province, the intesa sanpaolo skyscraper and future installation of the skyscraper of regional government “regione piemonte”. some of these installations are very close to each other and there are potential interference problems. in the case of open-loop heat pumps, water re-injected in the aquifer after its use is characterized by a different temperature than that in the undisturbed aquifer. this thermal disturbance propagates through the groundwater and may affect the temperature of water withdrawals operated by downstream installations. heat pump efficiency depends on the inlet temperature of water, and therefore there may be unforeseen changes in performances, which often leads to primary energy requirements larger than the initial expectations. 12. conclusion a multidisciplinary synthesis of the geological and hydrogeological researches on the subsoil of turin and suburbs is reported, direct to bringing together the different features of subsoil in a single contribution and favouring a more complete view. this work develops partly through the re-examination of the previous geological literature and partly thank to data specially collected (excavations, wells, piezometers and geognostic drillings). the most of the city and suburbs show a flat morphology at altitudes between 275 m and 230 m a.s.l., with a low slope towards the east, corresponding to the 166 forno m.g. et al. wide outwash fan essentially supplied by the dora riparia basin. the logs of the numerous boreholes drilled in its shallow subsoil report as the outwash sediments, referred to middle-upper pleistocene, generally cover an erosional surface essentially shaped on the villafranchian succession, referred to piacenzian and calabrian. this cover is relatively thin, with thickness between 9 and 57 m. the outwash sediments rest, instead, on the marine succession (asti sand or argille azzurre formation) in the northeastern sector of this area (between torino and settimo torinese), where they show thickness of 10-27 m. these sediments are sandy gravel with minor lenses of sandy silt, essentially referred to the dora riparia basin with the contribution of the stura di lanzo basin. narrow terraces gently sloping towards ne are located only along the current po river, entrenched in the dora riparia alluvial fan. these terraces are formed by the po river sediments, with thickness of 13-21 m, that cover an erosional surface essentially shaped on the miocene-pliocene marine succession. the new excavations for the building of the intesa sanpaolo skyscraper and the construction of the subway (line 1 of the metro) and underground railway pass as well as a new borehole near the po river promote a more detailed knowledge of the surficial outwash sediments, allowing to distinguish different sedimentary facies (i.e. specifying the location of sandy silty lenses). they are characterized by a various degree of cementation, that results particularly remarkable along the current dora riparia river, supplied by a carbonatic basin. boulders of considerable size (approximately 1 m in diameter) were locally found within these outwash deposits during the excavation for the intesa sanpaolo skyscraper, referred to glacial route phenomena. the setting of turin subsoil is also connected to the recent deviation of the po river, that now develops at the nw foot of turin hill and instead, during the middle and upper pleistocene, flowed south of turin hill (through the southern slope of turin hill and the poirino plateau). a new reading of this po deviation as an overflow is made, partly based on a re-examination of all the existing data and particularly the observation that the new river develops along an ancient course of the paleo dora and not represents a new fluvial bed. between the new collected data, the observation of peaty sediments along the more recent course of the paleo po in the poirino plateau (late upper pleistocene) reported by a geognostic borehole stratigraphy, is used to defining a difficult flow of the paleo po towards the east, before the overflow. the recent geological literature reports that the setting of turin subsoil is strictly influenced by the recent uplift of turin hill. the quaternary different terraced surfaces preserved on the turin hill slopes suggest a strong uplift of the hill and of its continuation in the shallow subsoil, that conditioned the flow of the po river south of turin hill. this paper summarizes the structural causes of this recent geological evolution and its relationship with seismicity. the turin sector is assigned to the 4th seismic zone, the lowest in the national seismic classification. in detail, the seismic potential of the city of turin is associated with two main districts, represented by the northern cottian alps and the borbera-grue (north-western apennines) seismic zones. the turin and suburbs subsoil shows two groundwater flow circuits corresponding to multi-layered deep aquifers, hosted in the villafranchian succession and in the pliocene marine deposits, and surficial aquifers, essentially flowing in the outwash cover. both the circuits flow from the alps edge towards east, where the current po river represents the main gaining element of the whole turin plain. in detail, the deep aquifers represent the most exploited groundwater system of the turin area, in particular for human consumption. the shallow aquifers, beside characterized by high productivity, show instead scarce quality due to industrial contamination in town and agricultural pollutants in rural areas. the aquifer temperature of the turin subsoil increases from the sectors close to the alps towards the central po plain, showing a progressive warming along the flow path. in the city of turin aquifer temperatures are 0.6 ÷1.6 °c higher than in rural sectors. this groundwater warming is linked to the urban heat island effect, which is mainly driven by the typical artificial land use. unusual warmer outliers (16-20 °c) are essentially connected to point heat sources, such as gshp systems, industrial districts and landfills. the turin territory is well suited to the analysis of the impact of heat pumps on groundwater. a significant number of installations of medium and large size groundwater heat pumps develops and this number is still increasing. among these installations, it is possible to mention the politecnico di torino, the egyptian museum, the palace of the province, the intesa sanpaolo skyscraper and the future installation of the skyscraper of regional government “regione piemonte”. acknowledgements the authors are grateful to luciano masciocco and francesca lozar for the stratigraphic data about the botanic garden borehole. thanks to massimo trossero for making the poirino core available and useful discussion. the authors are also grateful to the reviewers maurizio del monte e paolo mozzi for the supportive comments and suggestions. references arca s., beretta g. (1985) prima sintesi geodeticageologica sui movimenti verticali del suolo nell’italia settentrionale (1897-1957). boll. geod. sc. aff., 2, 125-156. baccino g., lo russo s., taddia g., verda v. (2010) energy and environmental analysis of an openloop ground water heat pump in a urban area. thermal science, 14, 693-706. barbero d., boano p., colla m.t., forno m.g. (2007) pleistocene terraced fluvial succession, northern slope of the torino hill. quaternary international, 171-172, 64-71. barbero d., de luca d.a., forno m.g., lasagna m. (2016) preliminary results on temperature distribution in the quaternary fluvial and outwash deposits of the piedmont po plain (nw italy): a synthesis on the turin subsoil stratigraphy and hydrogeology 167 statistical approach. rend. online soc. geol. it., 41, 272-275. benz s.a., bayer p., menberg k., jung s., blum p. (2015) spatial resolution of anthropogenic heat fluxes into urban aquifers. sci. tot. environ., 524525, 427-439. biella g.c., polino r., de franco r., rossi p.m., clari p.a., corsi a., gelati r. (1997) the crustal structure of the western po plain: reconstruction from the integrated geological and seismic data. terra nova, 9, 28-31. bigi g., castellarin a., coli m., dal piaz g.v., sartori r., scandone p., vai g.b. (1990) structural model of italy, sheet 1, c.n.r., progetto finalizzato geodinamica, litografia s.el.ca, firenze. boano p., forno m. g. (1999) la successione “villafranchiana” nell’area di castelnuovo don bosco (asti). il quaternario, it. journ. quatern. sc., 12(2), 161-194. boano p., forno m. g., lucchesi s. (2004) pleistocene deformation of the collina di torino inferred from the modelling of their fluvial succession. il quaternario, it. journ. quatern. sc., 17(2/1), 145-150. bove a., casaccio d., destefanis e., de luca d. a., lasagna m., masciocco l., ossella l., tonussi m. (2005) idrogeologia della pianura piemontese. regione piemonte, mariogros industrie grafiche s.p.a., torino, pp. 15. bucci a., barbero d., lasagna m., forno m.g., de luca d.a. (2017) shallow groundwater temperature in the turin area (nw italy): vertical distribution and anthropogenic effects. environ. earth sci., 76, 221. burns e.r., ingebritsen s.e., manga m., williams c.f. (2016) evaluating geothermal and hydrogeologic controls on regional groundwater temperature distribution. water resour. res., 52, 1328-1344. carraro f. (2012) geologia del quaternario. l’evoluzione geologica degli ambienti superficiali. dario flaccovio ed., palermo, 393 pp. carraro f., collo g., forno m. g., giardino m., maraga f., perotto a., tropeano d. (1995) l'evoluzione del reticolato idrografico del piemonte centrale in relazione alla mobilità quaternaria. in: polino r., sacchi r. (eds.) atti del convegno "rapporti alpi -appennino" e guide alle escursioni (peveragno (cn), 31 maggio-1 giugno 1994). rend. ac. naz. sc., 14, 445-461. carraro f., lucchesi s. (2004) application of integrated allostratigraphy to the geological survey of the central piedmont plain. in: g. pasquarè, c. venturini (eds.), mapping geology in italy. apat dipartimento difesa del suolo/servizio geologico d’italia, 69-76. castagna s., de luca d.a., lasagna m. (2015a) eutrophication of piedmont quarry lakes (northwestern italy): hydrogeological factors, evaluation of trophic levels and management strategies. j. env. assmt. pol. mgmt., 17(4), 21 pp. castagna s., dino g.a., lasagna m., de luca d.a. (2015b) environmental issues connected to the quarry lakes and chance to reuse fine materials deriving from aggregate treatments. in: g. lollino et al. (eds.), engineering geology for society and territory, 5, urban geology, sustainable planning and landscape exploitation, 71-74. springer international publishing switzerland, 2015. castellarin a. (1994) strutturazione eoe meso-alpina dell’appennino settentrionale attorno al ‘‘nodo ligure’’. studi geol. camerti, vol. spec., crop 11a, 99-108. charrier g., peretti l. (1977) ricerche sull'evoluzione del clima e dell'ambiente durante il quaternario nel settore delle alpi occidentali italiane. vii. boll. ist. orto bot. univ. torino, 22, 157-192. compagnoni r., forno m.g. (1992) significato geologico di depositi fluviali ghiaiosi pleistocenici medi nella collina di torino. il quaternario, it. journ. quat. sc, 5(1), 105-122. de luca d., ossella l. (2014) assetto idrogeologico della città di torino e del suo hinterland. geologia dell'ambiente, 1(suppl.), 10-15. de luca d.a., destefanis e., forno m.g., lasagna m., masciocco l. (2014) the genesis and the hydrogeological features of the turin po plain fontanili, typical lowland springs in northern italy. bull. eng. geol. environ., 73, 409-427. de luca d.a., masciocco l., caviglia c., destefanis e., forno m.g., fratianni s., gattiglio m., lasagna m., gianotti f., latagliata v., massazza g. (2015) distribution, discharge, geological and physicalchemical features of the springs in the turin province (piedmont, nw italy). in: g. lollino et al. (eds.), engineering geology for society and territory, 3, river basins, reservoir sedimentation and water resources, 253-256. springer international publishing, switzerland. de rienzo f., oreste p., pelizza s. (2009) 3d gis supporting underground urbanization in the city of turin (italy). geotechnical geological engineering, 27(agosto), 539-547. debernardi l., de luca d.a., lasagna m. (2008) correlation between nitrate concentration in groundwater and parameter affecting aquifer intrinsic vulnerability. environ. geol., 55, 539-558. dela pierre f., piana f., fioraso g., boano p., bicchi e., forno m. g., violanti d., clari p.a., polino r. (2003) note illustrative della carta geologica d'italia alla scala 1:50.000. foglio 157 “trino”. apat, roma, 147 p. devoti r., esposito a., pietrantonio g., pisani a.r., riguzzi f. (2011) evidence of large scale deformation patterns from gps data in the italian subduction boundary. earth planet. sci. lett., 311, 230-241. falletti p., gelati r., rogledi s. (1995) oligo-miocene evolution of monferrato and langhe, related to deep structures. in: polino r. & sacchi r. (eds.), atti del convegno “rapporti alpi-appennino e guide alle escursioni”: peveragno (cn) 31 maggio 1 giugno 1994. accad. naz. sci., 14, 1-19. festa a., boano p., irace a., lucchesi s., forno m. g., dela pierre f., fioraso g., piana f. (2009a) foglio 156 “torino est” della carta geologica d'italia alla scala 1:50.000. apat, agenzia per la protezione dell'ambiente e per i servizi tecnici 168 forno m.g. et al. dipartimento difesa del suolo, roma. festa a., dela pierre f., irace a., piana f., fioraso g., lucchesi s., boano p., forno m.g., bicchi e., violanti d., trenkwalder s., ossella l., bellardone g., campus s., tamberlani f. (2009b) note illustrative del foglio 156 “torino est” della carta geologica d'italia alla scala 1:50.000. apat, agenzia per la protezione dell'ambiente e per i servizi tecnici dipartimento difesa del suolo, roma, 1-143. forno m.g. (1990) aeolian and reworked loess in the turin hills (northwestern italy). quatern. intern., 5, 81-87, oxford. forno m.g., ben g., boano p., bocca p., boero v., compagnoni r. (2002) lembi di depositi fluviali provenienti dai bacini alpini nordoccidentali sulla collina di torino presso villa gualino (nw italy). il quaternario, it. journ. quatern. sc., 15(2), 175185. forno m.g., gattiglio m., comina c., barbero d., bertini a., doglione a., irace a., gianotti f., martinetto e., mottura a., sala b. (2015) stratigraphic and tectonic notes on the villafranca d’asti type-area and castelnuovo don bosco sector (asti reliefs, piedmont). alp. mediterr. quatern., 28(1), 5-27. forno m.g., gregorio l., vatteroni r. (2009) la successione stratigrafica del settore destro del conoide di lanzo e il suo significato per l’utilizzo del territorio. convegno nazionale aigeo: “ambiente geomorfologico e attività dell’uomo: risorse, rischi, impatti”, torino 28-30 marzo 2007, mem. soc. geogr. it, 87 (i-ii), 237-247. forno m.g., lucchesi s. (2005) la successione fluviale terrazzata pleistocenica dei versanti occidentale e nord-occidentale della collina di torino. il quaternario it. journ. quat. sc., 18(2), 123-134. forno m.g., lucchesi s. (2014) la successione pliocenico-quaternaria su cui è edificata la città di torino e il suo significato per l’utilizzo del territorio. geologia dell'ambiente, 1(suppl.), 3-10. fubelli g., fioraso g., comina c., bonasera m., bosco f., umili g., biason e., garau m. (2018) multidisciplinary approach to detect the seismogenic source of the tortona 1828 earthquake. geophysical research abstracts, 20, egu20187725, 2018 egu general assembly 2018. gattiglio m., forno m.g., comina c., doglione a., violanti d., barbero d. (2015) the involving of the pliocene-pleistocene succession in the t. traversola deformation zone (nw italy). alp. mediterr. quatern., 28(1), 59-70. gelati r., gnaccolini m. (1982) evoluzione tettonicosedimentaria della zona limite tra alpi ed appennino tra l’inizio dell’oligocene ed il miocene medio. mem. soc. geol. it., 24, 183-191. ivy-ochs s., lucchesi l., baggio p., fioraso g., gianotti f., monegato g., graf a., akçar n., christl m., carraro f., forno m.g., schlüchter c. (2018) new geomorphological and chronological constraints for glacial deposits in the rivoli-avigliana end-moraine system and the lower susa valley (western alps, nw italy). j. quat. sc., 33, 550562. lasagna m., de luca d.a. (2017) evaluation of sources and fate of nitrates in the western po plain groundwater (italy) using nitrogen and boron isotopes. environ. sci. pollut. res., 1-16. lasagna m., de luca d.a., franchino e. (2016a) nitrate contamination of groundwater in the western po plain (italy): the effects of groundwater and surface water interactions. environ earth sci., 75, 240. lasagna m., de luca d.a., franchino e. (2016b) the role of physical and biological processes in aquifers and their importance on groundwater vulnerability to nitrate pollution. environmental earth sciences, 75, 961. lasagna m., franchino e., de luca d.a. (2015) areal and vertical distribution of nitrate concentration in piedmont plain aquifers (north-western italy). g. lollino et al. (eds.), engineering geology for society and territory, 3, river basins, reservoir sedimentation and water resources, 389-392. springer international publishing, switzerland. lo russo s., taddia g. (2009) groundwater in the urban environment: management needs and planning strategies. american journal of environmental sciences, 5(4), 493-499. lo russo s., taddia g., baccino g., verda v. (2011) different design scenarios related to an open loop groundwater heat pump in a large building: impact on subsurface and primary energy 387 consumption. energy and buildings, 43, 347-357. lucchesi s. (2001) sintesi preliminare dei dati di sottosuolo della pianura piemontese centrale. riv. ass. geol. amb. geam, 28(2-3), 115-121. martinelli g., dadomo a., de luca d.a., mazzola m., lasagna m., pennisi m., pilla g., sacchi e., saccon p. (2018) nitrate sources, accumulation and reduction in groundwater from northern italy: insights provided by a nitrate and boron isotopic database. appl. geochem., 91c, 23-35. michetti a.m., giardina f., livio f., mueller k., serva l., sileo g., vittori e., devoti r., riguzzi f., carcano c., rogledi s., bonadeo l., brunamonte f., fioraso g. (2012) active compressional tectonics, quaternary capable faults, and seismic landscape in the po plain (n italy). annals of geophysics, 55 (5), 969-1001. morelli m., piana f., mallen l., nicolò g., fioraso g. (2011) iso-kinematic maps from statistical analysis of ps-insar data of piemonte, nw italy: comparison with geological kinematic trends. remote sensing of environment, 115, 1188-1201. mosca p., polino r., rogledi s., rossi m. (2010) new data for the kinematic interpretation of the alpsapennines junction (northwestern italy). int. j. earth sci., 99, 833-849. pelizza s. (2010) l’immagine tecnica virtuale del sottosuolo di torino. convegno geam “tecnologia dell’idrofresa per la realizzazione di diaframmi profondi in terreni difficili”, torino 16 giugno 2010, 5-10. pelizza s. (2014) eterogeneità geologico-tecniche del sottosuolo nell’area torinese e riflessi applicativi per gli scavi. geologia dell'ambiente, 1(suppl.), 63 synthesis on the turin subsoil stratigraphy and hydrogeology 169 ms. received: marz 28, 2018 final text received: october 25, 2018 68. perrone g., morelli m., piana f., fioraso g., nicolò g., mallen l., cadoppi p., balestro g., tallone s. (2013) current tectonic activity and differential uplift along the cottian alps/po plain boundary (nw italy) as derived by ps-insar data. journ. geodynam., 66, 65-78. piana f., polino r. (1995) tertiary structural relationships between alps and apennines: the critical torino hill and monferrato area, northwestern italy. terra nova, 7, 138-143. piana f., fioraso g., irace a., mosca p., d’atri a., barale l., falletti p., monegato g., morelli m., tallone s., vigna g.b. (2017) geology of piemonte region (nw italy, alps-apennines interference zone). journal of maps, 13, 2, 395-405. piana f. (2000) structural setting of western monferrato (alps-apennines junction zone, nw italy). tectonics, 19, 943-960. pieri m., groppi g. (1981) subsurface geological structures of the po plain, italy. quad. cnr. 414, progetto finalizzato geodinamica, roma, 13 pp. pignone m., castello b., moschillo r., nostro c., selvaggi g. (2013) seismicity map of italy, 20002012. ist. nazionale di geofisica e vulcanologia. reimer p.j. et al. (2013). intcal13 and marine13 radiocarbon age calibration curves 0-50,000 years cal bp. radiocarbon, 55, 1869-1887. sambuelli l., comina c., fiorucci a., dabove p., pascal l., colombero c. (2017) a 5-km long waterborne cves survey of the po river in the town of turin: preliminary results. geophysics, 82(6), b189b199. taylor c.a., stefan h.g. (2009) shallow groundwater temperature response to climate change and urbanization. j. hydrol., 375, 601-612. tropeano d. (1986) “elephantidae” pleistocenici della pianura piemontese meridionale. mammalia. riv. piem. st. nat., 7, 51-76. tropeano d. (1987) resti di mammiferi wurmiani nel sottosuolo di moncalieri-la loggia (pianura piemontese meridionale). riv. piem. st. nat., 8, 77 -92. tropeano d., cerchio e. (1984) l’orizzonte torboso würmiano nel sottosuolo della pianura piemontese meridionale. osservazioni preliminari. boll. ass. miner. subalp., 21(3), 199-221. tropeano d., cerchio e. (1987) studio palinologico e stratigrafico preliminare dei depositi quaternari della pianura del po tra la foce del pellice e del sangone. riv. piem. st. nat., 8, 65-75. tropeano d., olive p. (1989) vitesse de la sédimentation holocène dans la plaine occidentale du pô (italie). bull. ass. fran. ét. quatern., 26(2), 65-71. vezzoli g., forno g., andò s., hron k., cadoppi p., rossello e., tranchero v. (2010) tracing the drainage change in the po basin from provenance of quaternary sediments (collina di torino, italy). quatern. intern., 222, 64-71. 170 forno m.g. et al. microsoft word 03_galli_lm05.doc available online http:/amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 25 (2), 2012, 105-123 may 2012 emilia earthquakes (mw 6, northern italy): macroseismic effects distribution and seismotectonic implications paolo galli1, sergio castenetto1, edoardo peronace2 1 dipartimento della protezione civile, roma, (italy) 2 cnr-igag, ar montelibretti, roma (italy) corresponding author: p. galli <paolo.galli@protezionecivile.it> abstract: we have carried out the macroseismic survey of both the may 20 (mw 6.1) and may 29 (mw 6.0) earthquakes in emilia (po plain, northern italy) by applying the mercalli-cancani-sieberg scale, on 190 localities, mainly spread south of the po river. our data account for an io 7 mcs evaluated for both earthquakes, with an imax 7-8 assigned to the village of rovereto after the mainshock of may 29. damages were mainly focused on the historical buildings of the region, such as churches, castles, and towers, beside on the industrial warehouses, the collapse of which caused most of the victims of the two mainshocks. churches and bell-towers were hit also in villages located far from the mesoseismic area, resulting often the only buildings affected by the earthquake. the seismic shaking induced also hundred of liquefaction phenomena that, in some places, have increased the damage level to buildings. by comparing macroseismic and instrumental data (i.e., hypocentres distribution, focal mechanisms, interferograms), to the deep geological structures of the region, it emerges that the may 20 mainshock was caused by a segment of the outer ferrara thrusts front, whereas the may 29 mainshock by the mirandola thrust. as these thrusts have been seismically silent in the past millennium, the current sequence fills partially a seismic gap along the seismogenetic structures of the buried outer apenninic front. keywords: macroseismic survey, 2012 emilia earthquake, po plain, buried thrusts, active tectonics. 1. introduction at dawn of may 20, 2012, a moderate earthquake (mw 6.1; qrcmt, 2012) hit a wide area of the eastern po plain, awakening most of the inhabitants of northern italy. the mainshock was preceded in the night by a mw 4.3 foreshock and it has been followed by dozens aftershocks with ml>4 and at least 12 with mi≥4.5 (tab. 1). in the morning of may 29, a second mainshock (mw 6.0; qrcmt, 2012) struck roughly the same villages, causing, if possible, more panic in the population, scaring and awakening people from florence and pisa in the apennines, to venice and milan in northern italy. unfortunately, due to this event, the death toll rose from 9 to 27, with most of the victims caused by the collapse of the industrial warehouses, as it was already happened during the first shock. earthquakes are an unexpected event in this region, as testified by the lack of local epicentres in the seismic catalogues and by the consequent low level of the seismic classification (seismic zone 3: 10% probability of exceeding ag ≤0.15 in 50 years; ag, maximum horizontal acceleration; dpc, 2012). apart from the warehouses and hundreds of old, crumbling farmsteads spread all over the open country, the heavy damages focused on historical buildings, such as churches, bell-towers, castles, towers and palaces that were severely hit also in villages located very far from the epicentre, outside the mesoseismic area (i.e., 6 mcs). on the other hand, residential buildings suffered only light and/or moderate damage, apart from some exceptional cases. the mesoseismic area is roughly wnw-ese elongated, reflecting the geometry, kinematics and rupture dynamics of the seismogenetic structure, which is supposed to be a complex structural envelope of buried, ~nverging, “apenninic” thrusts, as testified by all the focal mechanisms of the sequence (qrcmt, 2012), and by the available oil-exploration seismic profiles (pieri and groppi, 1981; cassano et al., 1986). both mainshocks have been accompanied by an impressive amount of liquefaction phenomena (i.e., sand blows, sand volcanoes, surface breaks and lateral spread) which, in some case, caused also severe damage to buildings, pipelines and roads. in order to provide the civil protection department of italy (dpc) with an expeditious, scientific and homogeneous pattern of the damaged localities, the macroseismic survey started few hours after the may 20 mainshock, proceeding continuatively until june 15. as in all the previous italian earthquakes, it has been carried out by using the mercalli-cancani-sieberg scale (mcs; sieberg, 1930) accordingly to the methodology proposed by molin (2003; 2009). we succeeded in visiting 52 localities affected by the may 20 mainshock before the second event of may 29, with a total of 190 visited by the end of the survey, and dozens villages visited two-three times, because of the progressive growth of damage during the sequence. in this paper we present the results of this survey, together with the intensity datapoints distribution of both the may 20 mainshock and the cumulated distribution of may 20 and 29 earthquakes, hypothesizing also their galli p. et al. 106 fig. 1 structural map of the area affected by the 2012 seismic sequence (yellow dotted lines, buried thrusts, from bigi et al., 1992; dashed line, front of ferrara thrusts: fft. bold dots, front of cavone-mirandola thrusts. circles, 2012 earthquakes, proportional to ml>2.0. white, 19-28 may sequence; red, 29 may-5 june sequence; orange, up to july 5. iside, 2012). focal mechanisms from qrcmt (2012) and tdmt (2012). black and white arrows are gps horizontal coseismic offsets measured after the may 20 event, accounting for ~4 cm of shortening between sermide (northernmost arrow) and san giovanni in persiceto (southernmost arrow; anderlini et al., 2012). in background the differential interferogram elaborated by tre (2012) from descending radarsat satellite data (see line of sight color-scale: los. may 12-june 6), which magnificently shows the two “anticlines” grown on may 20 (~14 cm) and 29 (~11 cm), respectively. sections a-a’ and b-b’ are in figs. 2-3, respectively. tab. 1 events with ml≥4.5 recorded between may 20 and june 15 within the epicentral area of the emilia earthquake of may 2012 (iside, 2012). the last column provides the epicentral intensity (mcs) assigned to the two mainshocks in this paper. may 2012 emilia earthquakes (mw 6, northern italy): macroseismic effects … 107 possible seismotectonic framework. moreover, we provide a brief description of the liquefaction phenomena and of their areal occurrence.  2. seismotectonic framework of the may 2012 sequence the villages struck by the may earthquakes are all founded in the holocene-historical alluvial plain deposits of the po river and of its dextral tributaries, mainly the secchia, panaro and reno rivers, at elevation ranging 10-30 m a.s.l. in this part of the plain, the soft post-roman deposits (4th-6th cent. ad to present) have a thickness ranging 5-10 m, depending from the presence of fluvial ridges or paleo-riverbeds, whereas the post last glacial maximum-holocene fluvial deposits reaches generally 20 m (“subsintema di ravenna”, post 15-17 kyr bp calibrated age; cgi, 2009). since the fifties, eni-agip hydrocarbon exploration led to the discovery of a buried, imbricated fold and thrust system up to 40 km north of the outcropping apenninic frontal margin (pieri and groppi, 1981), below the quaternary deposits of the po valley) (see dotted and dashed yellow lines in fig. 1). the thrust belt has developed during neogene-quaternary in the hangingwall of a westward subduction zone (spakman, 1990), the eastward hinge-retreat of which probably caused the foreland flexure, and the consequent progressive thrusts front migration toward the eastwardmoving foredeep basins (patacca et al., 1990). in the investigated area, the buried apenninic chain front matches with the emilian and ferrara folds and thrusts, which are generally sealed by thick pleistocene-holocene flat layers (figs. 2-3). according to castellarin (2001, and reference fig. 2 geological cross section across the cavone-mirandola and outer ferrara folds and thrusts front (modified from carminati et al., 2010), showing the hypocentral distribution of the may 19-28 seismic sequence (events within 10 km from the section trace a-a’ in fig. 1. iside, 2012). the mw 6.1 mainshock and the successive sequence lay entirely at depth along the ferrara thrust front. q, quaternary; mup, middle-upper pliocene; lp, lower pliocene; ucm, upper cretaceous-miocene; tlc, triassic-lower cretaceous. fig. 3 geological cross section across the cavone-mirandola and outer ferrara folds and thrusts front (modified from pieri and groppi, 1981), showing the hypocentral distribution of the may 29-june 05 seismic sequence (events within 10 km away from the section trace b-b’ in fig. 1. iside, 2012). the mw 6.0 mainshock and the successive sequence lay, in this case, along the mirandola anticline frontal thrust and/or over the sole thrust. q, quaternary; mup, middle-upper pliocene; plio, pliocene; um, upper miocene; mm, middle miocene; mio, miocene; mz, mesozoic. galli p. et al. 108 therein), the structural growing at the front of both the buried thrusts and of the outcropping chain ceased with the pleistocene, i.e. it was certainly active during the late pliocene-early pleistocene, with some structures growing also in middle to late pleistocene times (e.g., mirandola anticline; scrocca et al., 2007). indeed, according to pierdominici and heidbach (2012), in the area struck by the may 2012 sequence the present-day stress data records exhibit a constant nne–ssw compression regime. this is also evidenced by the geodetic velocity solutions obtained from the analyses of gps data (serpelloni et al., 2005), accounting for ~0.8 mm/yr crustal shortening oriented along the same direction. the may 2012 earthquakes confirmed this tectonic framework, as both the mainshocks and all the major aftershocks have a reverse faulting focal mechanism, striking roughly wnw-ese – i.e. paralleling the different thrust system of the area (fig. 1) – and hypocentral depth within the upper 10 km of crust (figs. 2-3). shortening due to may 20 event has been evaluated by gps data analyses (anderlini et al., 2012) at ~4 cm along a nnw-sse direction, between the villages of sermide (to the north) and san giovanni in persiceto (to the south; see bold arrows in fig. 1). moreover, the differential descending interferogram obtained by tre (2012, radarsat satellite) for both mainshocks (interval may 12-june 6) vividly represents the snapshot of the coseismic growing anticlines at surface (fig. 1). here the may 20 anticline matches with the hangingwall of the outer ferrara thrusts (fig. 2; see white epicentres in fig. 1), and it is crossed just in the middle by the panaro river where, according to the number of visible fringes (each one of 2.8 cm), it reaches the maximum uplift of ~14 cm. on the other hand, the may 29 anticline fits with the hangingwall of the mirandola thrust (fig. 3. see red epicentres in fig. 1), with an uplift of ~11 cm, as inferable by the number of fringes. really, according to scrocca et al. (2007), the structural and stratigraphical setting of this thrust-related fold suggests a syn-sedimentary growth also during the middle-late pleistocene, with a decreasing rate of tectonic uplift during the last 1.4 ma from 0.53 mm/yr to 0.16 mm/yr in the late pleistocene, which could be taken as a conservative vertical slip rate also for the present. as far as the historical seismicity of this region is concerned, according to all the available seismic compilations the area has not been affected by events with epicentral intensity io>6 mcs (mercalli-cancanisieberg; sieberg, 1930). this can be easily seen from figure 4 which reports the io>6 epicentres contained in the italian seismic catalogue cpti11 (rovida et al., 2011), all falling at the eastern and western boundaries of the region hit in 2012. in detail, the strongest event occurred in the vicinity of the may 2012 epicentres (~35 km far away), and the only one relevant for the villages struck by the current sequence, is the ferrara earthquake (november 17, 1570; io 7-8 mcs, mw 5.46). its mesoseismic area fig. 4 distribution of the historical epicentres (cpti11) within the area hit by the 2012 sequence (stars, instrumental epicentres of may 20 and 29; orange, macroseismic epicentre of the cumulated effects of may 20 and 29 events). dotted and dashed yellow lines are the buried front of the cavone-mirandola and ferrara folds and thrusts (see fig. 1). 1570 earthquake-induced liquefactions are from galli (2000). note the absence of significant historical epicentres in the investigated area. may 2012 emilia earthquakes (mw 6, northern italy): macroseismic effects … 109 is nw-se elongated (postpischl, 1985), paralleling the local buried front of the ferrara thrusts which are, in turn, the eastern prolongation of those activated in the current sequence. also in this case, the sequence was characterized by more mainshocks, and it lasted at least until 1572. among the localities hit by the 2012 events, the 1570-earthquake historical sources account for damages in bondeno at the roof of the hospital and of the oratory; in corpo reno at the roof of saint antony church (in marzola, 1976), while in cento and finale emilia they report just the fall of some chimney (asm, 1570a; 1570b), suggesting – in the whole – effects of 6 mcs (the italian macroseismic database dbm11=locati et al., 2011 reports 7 mcs to bondeno, 6-7 mcs to corpo reno, and 6 mcs to cento and finale emilia). similarly to what happened in the 2012 events, also in the 1570 earthquake many liquefaction phenomena occurred in different localities, mainly surrounding ferrara, and up to ficarolo, on the left bank of the po river (galli, 2000; see fig. 4). prior to 1570, a coeval chronicle (giacomo da marano, 14th cent.) suggests the existence of another strong earthquake in ferrara in the year 1346 when, on february 22 “many houses fell down, palaces, towers… and, in the villages, tenements, barns… and other buildings”. the event was felt also in modena (even if giovanni da bazzano, 15th cent., records it on february 8) and likely in other places of the po plain. however, due to the scarcity of news, it is impossible to provide certain parameters or to associate it to a seismogenic structure. it could be really occurred everywhere around ferrara and, for instance, also in the eastern part of the region hit in 2012. dbmi11 reports also two minor earthquakes (io 6 mcs) within the 2012 mesoseismic area. the first one occurred on december 6, 1986 (mw 4.35), with effects of 6 mcs in bondeno, finale emilia, gavello and scortichino; the second one on may 8, 1987 (mw 4.56), with similar effects in camposanto, finale emilia, massa finalese and san felice sul panaro. taking into account their epicentral location (see fig. 4), both could be related to the same seismogenetic structure of the 2012 events. it is worth noting that, due to the 1987 event, several fractures opened in the field of rivara (san felice sul panaro), forming en-echelon linear settlements, 10-20 cm wide and 1-2 m deep which were not attributed to any liquefaction phenomena, but to mechanisms associated to sinkhole formation (bianchi et al., 2008). finally, on october 15, 1996, at the western boundary of the investigated area, an earthquake with mw 5.41 (cpti11. io 7 mcs: massucci et al., 1996; de canini et al., 1997) affected mainly bagnolo in piano and correggio where severe damages were observed to few ancient buildings (i.e., the torrazzo in bagnolo and san francesco church in correggio), light cracks in many brick-masonry buildings, and also in two reinforced-concrete (r.c.) frame structure (i.e., cracks in the brick-infill of the pilotis), beside the fall of chimneys and tiles. at that time, the earthquake was associated to the rupture of the left-lateral ramp of the cavone anticline (de canini et al., 1997), i.e., the western prolongation of the mirandola structure. further north, in 1806 a similar earthquake caused damage in correggio, and also in brescello, campagnolo emilia, novellara and viadana (effects estimated as 7 mcs in ismes, 1985), and also in other localities hit by the 2012 sequence, as reggiolo and carpi (6-7 mcs). from all the above, we can conclude that at least in the past ~600 years (see the discussion of catalogue completeness in stucchi and albini, 2000), the epicentral area of the 2012 events: 1) has likely never generated earthquakes with energy similar to that associated to the 2012 sequence (i.e., mw≥ 5.8); 2) has likely never been affected by damage caused by external earthquakes, with the only exception of those related to the 1570 ferrara event in the easternmost portion, and to the 1806 and 1996 events in the westernmost portion; 3) has been sometime affected by local, mw≤4.6 events, probably generated by the same 2012 seismogenetic structures. therefore, it is likely that the 2012 mainshocks is the real first, and somewhere the last, anti-seismic testing for all the historical buildings of the region. 3. the macroseismic survey as aforementioned, the attribution of the site intensity (is) has been achieved by applying the mcs macroseismic scale, that is the intensity scale of the whole italian macroseismic database (dbmi11; ~86000 datapoints), and not the more recent european macroseismic scale (ems; grünthal, 1998). indeed, as the mcs scale does not fully account for the vulnerability of each single building, it allows a more expeditious application during the survey, providing information directly correlated to the damage level, i.e. that of immediate interest to the civil protection purposes, both in terms of rescue planning and emergency management (molin, 2009; galli et al., 2009). in particular, we adopted the methodology proposed by molin (2003; 2009), who differentiated five damage levels (1-5: light, moderate, severe, destruction, collapse), providing the percentages of damage level (5%, 25%, 50%, 75%, 100%) that are representative for each mcs degree (fig. 5), as implicitly contained in the original scale (sieberg, 1930). tab. 2 from left to right, damage progression (levels 1-5) to be adopted for an homogenous application of the mcs scale for is ≥ 5 (from molin, 2009). for instance, the mcs 6 degree has to be assigned to those localities in which the ~50% of buildings presents level 1 damage, ~25% level 2, and where the 5% has bee affected by severe damage (level 3). analgalli p. et al. 110 ogously, the 8 mcs degree is reached when a quarter of the buildings has been destroyed (level 4), including a ~5% of total collapse (level 5), whereas half of the village presents severe damage (level 3). this means that in a locality with 1000 building, 500 should be severely damaged, 250 of which destroyed and 50 collapsed. 3.1. may 20 earthquake survey the macroseismic survey started in the morning of may 20 from the epicentral area, reaching in the days after localities farther and farther in the provinces of modena, ferrara and mantua, for a total of 52 visited localities belonging to 30 municipalities. even if necessary incomplete, the results of this first survey have allowed to define the area of the most severe effects (is≥ 6 mcs), which is wnw-ese elongated west to the instrumental epicentre, in full agreement with the focal mechanism of the mainshock (fig. 5). in detail, the area was extended less than 25 km in this direction, matching entirely the hangingwall of the fig. 5 intensity datapoint distribution of the may 20 mainshock (white circle, proportional to mcs degree). the background image roughly indicates the areal shaking in mcs terms. dashed line is the interpolated 6 mcs isoseismal; dashed blue line is the buried front of ferrara thrusts (see fig. 1) to which the focal mechanisms are referred (tdmt, 2012 and qrcmt, 2012)°. tab. 3 instrumental (left), and macroseismic (right) parameters of the two mainshocks of the emilia 2012 sequence (ingv source, and this paper). may 2012 emilia earthquakes (mw 6, northern italy): macroseismic effects … 111 outer ferrara thrusts front (ftt in figs. 1, 5, and associated focal mechanisms), i.e. the seismogenetic structure responsible for this part of the sequence. outside this area, both to the west and to the east, we observed a raising of the intensities, respectively in the moglia area and sant’agostino, san carlo and mirabello. the maximum intensity (imax) estimated for this event is 7 mcs, assigned to mirandola and san felice sul panaro (fig. 5), with is 6-7 observed at finale emilia, canaletto, mortizzuolo and san carlo, and is≤6 mcs assigned to all the other localities. the epicentral intensity evaluated also through the boxer4 algorithm (gasperini et al., 1999) is io 7 mcs, while the equivalent moment magnitude resulted much more low (mw 5.1) than the instrumental value (mw 6.11). the epicentral coordinate derived by boxer4 identify a point located ~5 km south of the instrumental epicentre (figs. 4, 5). earthquake parameters have been summarized in tab. 3. most of the heavy damages, including total and partial collapses, affected tall, historical buildings, as churches (fig. 6), bell-towers, towers, castles (figs. 7-8), palaces, ancient farmhouses, beside many industrial warehouses in the outskirts of mirandola and sant’agostino (fig. 9). the residential housing estates, both in brickmasonry (reinforced and not) and in r.c., generally suffered low grade damage (levels 1-2), with sparse severe damages (level 3) and very rare partial collapses (usually of the roof-ledges, roofs and loading dock of crumbling houses) and destructions (level 4), beside diffuse fall of chimneys, tiles and plaster, almost everywhere focused within the old downtown. this fact explains why this earthquake, although it has happened in the night, has caused a limited number of victims (9), almost all night-shift workers in the industrial warehouses. severe damages in r.c. buildings have been observed in one case inside mirandola and in other three in its northern outskirts (light crushing of pillars and cracks on the brick-curtain walls), as in some apartment houses in cavezzo (fig. 10). in some cases, more than the seismic waves, damages have been induced by the huge liquefaction phenomena affecting the deposits below the buildings, with consequent loss of the bearing capacity, and differential settlement and/or tilting of the foundations. liquefaction occurred extensively in the villages located over the paleo-beds of the main rivers, as in sant’agostino, san carlo and mirabello, all founded along the abandoned reno fluvial-ridge. here, besides the damages to buildings, the surficial breaks related to the liquefaction settlement processes affected also roads and pipelines. by looking at figure 5, it emerges that the intensity bulge at the eastern side of the mesoseismic area is merely due to the effects of liquefaction on. in the far, main cities of the plain, we did not observe severe damage, not even affecting isolated buildings. in mantua and modena everybody has awakened getting into a panic, and rushing out in the streets; however, damages were limited to levels 1-2 to very few houses. ferrara, in turn, experienced levels 1-2 to several old houses downtown, mostly related to pre-existing cracks. we have recorded the fall or rotation of a dozen fig. 6 view of the mirandola cathedral (15th century) in the morning of may 20. at that time, only few architectural elements at the top of the façade were fallen down, beside the incipient façade detachment. inside, not visible, also part of the roof has fallen down. the church was damaged again, more seriously, by the may 29 mainshock. fig. 7 partial collapse of the estense castle (15th century) in finale emilia (is 6-7 mcs) in the morning of may 20. galli p. et al. 112 of chimneys, tiles, and sparse architectural elements hanging on the churches façades, beside the partial collapse of a small tower over the estense castle. actually, we had trouble in evaluating the site intensity in many localities, because of the extreme difference of damage level existing between recent residential housing (usually 1-2 storeys, reinforced brick-masonry villas) and the historical-monumental buildings. as mentioned before, while on one hand many churches, castles, bell-towers, towers and ancient palaces experienced severe damage (levels 3-4) or collapse (levels 4-5), on the other hand, private houses generally were not damaged at all, especially all those outside the small old towncentre. as in the 2009, mw 6.3 l’aquila earthquake (galli et al., 2009), we have choose to take more into account the effects recorded by the buildings inside the villages old-centre (almost all in brick unreinforced masonry), and to exclude entirely damages to industrial warehouses. in doing this, we think that the assigned intensities can be roughly comparable to those of the historical earthquakes contained in the italian seismic database (dbmi11). 3.2. may 29 earthquake survey soon after the second mainshock (mw 5.96), we re-started the macroseismic survey, visiting again the villages hit by the may 20 event, and extending it during the days after up to 190 localities belonging to 87 municipalities. in the whole, our observations cover the area of six provinces of emilia romagna, lombardy and veneto regions, i.e. 52 of modena, 32 of ferrara, 22 of bologna, 14 of reggio emilia, 53 of mantua and 11 of rovigo (fig. 11). generally speaking, we have observed a growth of the effects in the western part of the area, with an increase of 1-2 mcs degrees in some villages; severe damage in reggiolo (is 67 mcs), novi di modena (is 7 mcs), concordia sulla secchia (is 7 mcs; with some partial collapse and severe damage to the porchbuildings; fig. 12), moglia (is 7 mcs), and rovereto (is=imax 7-8 mcs; maximum intensity assigned in this earthquake) where several partial collapses and heavy damages occurred both in the brick-masonry houses of the old-centre and in some recent reinforced-masonry and r.c. buildings (figs. 13-15). in the other localities, generally west of mirandola, the intensity increase has been < 1 mcs degree. in mirandola, the mainshock of may 29 and the successive strong aftershock of the same morning (mw 5.3) caused the collapse of the 14th century saint francis church, which was only slightly damaged by the may 20 shock. moreover, it caused further collapses of the cathedral and several heavy damages and partial collapses to the ancient houses downtown, besides to some r.c. buildings, the same already struck on may 20. in cavezzo also, the increasing damage level has yield an higher intensity (at least is 7 mcs), mainly justified by the colfig. 8 finale emilia (is 6-7 mcs): collapse of the medieval clock-tower, and of the cathedral tympanum in the may 20 morning. the tower collapsed definitely during the seismic sequence. fig. 9 collapse of the sant’agostino’s ceramics warehouse. fig. 10 left, cavezzo (is 6 mcs), may 22: level 3-4 damage along the joint of a r.c. building inside the old-center; this building collapsed entirely because of the mainshock of may 29. right, mirandola (is 7 mcs), may 21: crushing of a pillar of a r.c. building in the old-centre. may 2012 emilia earthquakes (mw 6, northern italy): macroseismic effects … 113 lapse of the pilotis of three r.c. buildings and to the diffusion of level 3 damage to several brick-masonry houses in the old-centre. southward, outside the 6 mcs isoseismal (fig.11), both crevalcore and cento suffered more effects within the old-centre which presents now diffuse level 2 damage at about a quarter of the buildings, with some heavy damage (level 3) and sparse partial collapse of underroof walls. in turn, the damage area substantially did not extended northward. anyway, we have assigned is 5-6 mcs to several localities near the po river and, exceptionally, also north of it (castelmassa). heavy damage to isolated monumental structures (usually the churches or the bell-towers) have been observed in many villages to which we necessarily assigned is 5 mcs. indeed, these were the only buildings damaged by the seismic events that, instead, did not affect the remaining houses. however, the intensity datapoints listed in table 4 keeps the memory of these effects in the column dj, where labels a-b-c indicate heavy damage and/or collapse to buildings, towers/bell-towers and churches. in the whole, the 6 mcs area extended westward, reaching a length of 35 km, i.e. 10 km more then the may 20 event. also, two extreme intensity bulges exist to west and to east. the first one is now focused on reggiolo (it was on moglia, before), whereas the second is always that occupied by san carlo and mirabello. considering also these areas, the 6 mcs is elongated wnw-ese of ~55 km, with a n-s width of 15-20 km. by observing fig. 11, and assuming a rough similar vulnerability in all the surveyed localities, it is probable that the mentioned intensity bulges represents as many cases of geological amplification. in one of these, we have recognized the strong contribution of the liquefaction phenomena occurred extensively all along the paleochannel of the reno river, while in the others cases, only future geological analyses will hopefully reveal the causes of the seismic shaking increase. also for this earthquake, our intensity estimate refer mainly to the old-centre of the surveyed localities, as almost everywhere the may 29 mainshock struck more these than the modern outskirts (generally affected by sparse 1-2 level damage), apart some impressive exceptions as the one of rovereto (collapse of the pilotis of a new reinfig. 11 intensity datapoints distribution of the whole 2012 sequence (june 15 updating; white circles, proportional to intensity). also in this figure, the colour image in background suggests qualitatively the areal shaking in terms of mcs intensity. black dashed line is the 6 mcs degree isoseismal as interpolated from the intensity data. dashed and dotted blue lines are the ferrara and cavone-mirandola thrust fronts, respectively, i.e. the structures responsible for the whole sequence. black stars are the main events, with associated focal mechanisms (tdmt, 2012 and qrcmt, 2012). the two empty stars are the macroseismic epicentres of the may 20 (east) and of the cumulated may 20-29 mainshocks (west). note the four intensity bulges located outside the mesoseismic area (reggiolo, crevalcore, cento and san carlo) which indicate as many possible local amplification areas. galli p. et al. 114 forced brick-masonry 3-storey villas; fig. 15) or fossoli (level 3 damage to the first-second storey of some r.c. buildings). in some villages (e.g., cento, concordia, crevalcore, moglia, reggiolo, san giacomo delle segnate) damage is diffused in the porch-houses, i.e the typical building style of almost all the main streets of the po plain settlements. here we often observed damage level 2 and 3 affecting the columns and/or the pillars of the arches, with consequent damage of the overlaying wall of the first-second storey. we have tried to “close” the intensity points distribution both southward (modena and bologna provinces) and northward (ferrara, rovigo and mantua), identifying several localities affected by light damages in the mantua province, south to the po river, with the exception of castelmassa (left bank of po river, rovigo province), where we have observed several level 2 cracks to the porch-houses of the old-centre and to the churches and the theatre. on the other hand, we did not find significant damage increase east of san felice sul panaro, apart from the two quoted cases of crevalcore and cento, at southeast. fig. 13 left, rovereto (is=imax 7-8 mcs): level 3 damage affecting a r.c. building. right, mirandola (is 7 mcs): partial collapse of the under-roof walls of an unreinforced brick-masonry building of the old-centre (photos of may 29). fig. 12 concorda sulla secchia (is 7 mcs). collapse of inhabited, old unreinforced brick-masonry buildings inside the old-centre (photo of june 6). may 2012 emilia earthquakes (mw 6, northern italy): macroseismic effects … 115 fig. 14 cavezzo (is 7 mcs). total collapse of the pilotis of a r.c. building in the old-centre (photo of may 29). this building experienced level 2 damage because the may 20 mainshock, and was not inhabited when it crushed on may 29. . fig. 15 the impressive collapse of the brick-masonry pilotis of a new building in the outskirts of rovereto (is=imax 7-8 mcs). galli p. et al. 116 may 2012 emilia earthquakes (mw 6, northern italy): macroseismic effects … 117 table 4 mcs intensities (is) evaluated for the may 20 and for the may 29 (cumulated) emilia earthquakes. dj, severe damage to isolated buildings (is<6 mcs). pop and blds, number of inhabitants and buildings, respectively. through table 3, the latter column may suggest the quantity and level of damaged buildings for each locality. galli p. et al. 118 finally, it is worth noting that also during the may 29 seismic shaking, several liquefaction phenomena occurred, some of them in the same place as may 20, others in localities that were not previously affected. however, the strength of the phenomenon was certainly lower than the first case, and none further damage has been reported. we have found unreliable estimating the macroseismic parameters of the only may 29 shock, because of the cumulated effects with the preceding events. therefore, the epicentral intensity of the cumulated sequence (mainly may 20 and 29), calculated also through boxer4 algorithm, is io 7 mcs, with an equivalent magnitude always lower (mw 5.23) with respect to the instrumental one (mw 6.11 + mw 5.96). the final epicentral coordinates (tab. 3) identify a point located more than 15 km west of both the instrumental and macroseismic epicentre of may 20, and 5 km west of the instrumental one of may 29 (fig. 11). this westward drift of the barycentre of the macroseismic effects with respect to the instrumental ones may roughly indicate the rupture direction along the structures responsible at depth for the sequence, i.e. from east to west. 3.3. liquefaction as aforementioned, both mainshocks and mainly the first one – have induced hundred liquefaction phenomena all over the mesoseismic area. liquefaction is the transformation of a granular deposit from a solid state into a liquefied state as a consequence of the increased pore-water pressure determined by cyclic shaking (youd, 1977). the associated features may vary from place to place in geometry, type, and dimension, due to the different propagation and amplification of the seismic waves at the surface and to the differing site conditions (grain size and density of deposits, position of the ground-water level). in the eastern po plain region, liquefaction processes have already happened, and in particular during the quoted 1570 event, when in ferrara and in some neighbouring localities (san paolo bridge, san pietro church area, giara del po, la punta, polesino di san giovanni battista, polesino di san giorgio, torre della fossa), up to ficarolo, on the left bank of po river, several sand boils, volcanoes and ground settlements occurred (see in galli, 2000). indeed, on the basis of its geological properties and seismicity level, this sector of the po plain was long since classified as “liquefaction fig. 16 distribution of the liquefactions generated by the 2012 earthquakes vs mcs intensity (empty and black stars, macroseismic and instrumental epicentres, respectively). almost all the liquefaction cases fall within the 6 mcs area, with the exception of the may 29 cluster in quistello. note that liquefactions affect systematically the sandy deposits related to the abandoned paleo-bed of the main rivers (gray lines, from castaldini e raimondi, 1985), as the case of the paleo-reno, toward mirabello, of the paleo-secchia, toward cavezzosan felice sul panaro and san possidonio, or as the case of the abandoned paleo-beds of po river, further north. may 2012 emilia earthquakes (mw 6, northern italy): macroseismic effects … 119 susceptible zone” (galli, 1991; galli and meloni, 1993; galli and ferreli, 1995). nevertheless, recently, it has been surprisingly defined as scarcely or not prone to liquefaction by fioravante (2008). in may 2012 earthquakes, the most diffuse features typology (e.g. in galli, 2000) that we have observed can be related both to ground fissuring (“dry” ground fissures; with water emission; water and sand ejection: i.e. sand boils, sand volcanos. figs. 17-18) and to related ground deformation (linear settlement and lateral spread). all of these occurred in the agricultural fields and below buildings, roads and pipeline causing, in the latter cases, from light to severe damages (i.e., differential settlement; fig. 17). the most impressive phenomena are surely those happened in the easternmost side of the area, between sant’agostino, san carlo and mirabello (fig. 16), all villages built up over the paleo-channel of the reno river, a fluvial ridge emerging ~5 m above the plain. here, the liquefaction processes caused huge lateral spread mechanisms all along the fluvial ridge, with hundred meters long fractures arranged in complex en-echelon geometry, with synthetic and antithetic systems (e.g., graben-like features) and offsets reaching some decimetres (fig. 19). cracks affected also buildings, walls, pipelines and roads, causing severe damage and throwing over 1-m-thick layer of greyish, fine sand (fig. 20). water and sand have been ejected from ground fissures, but also from any preferential path met during the upward rising, as wells, shafts, piping systems, manhole, underground structures (car-box, cellars), and even phone booth and toilet bowl. by comparing the areal distribution of the surveyed liquefaction cases (e.g. in gruppo di lavoro liquefazione, 2012) with the mcs intensity assigned in this paper (fig. 16), it emerges that all the cases fall within the 6 mcs degree area, with the only exception of those happened in quistello (is 5-6 mcs), near the po river, whereas all happened less than 20 km from the two epicentres. this is in full agreement with the empirical relationships between io/is/mw and distance for liquefaction (galli, 2000) that foresee a boundary limit for mw 6 earthquake of ~40 km (n.b., this limit is respected also assuming the value of the equivalent magnitude calculated through boxer4 – mw 5.23 – which yields a distance of 17 km). however, the most striking fact emerging from figure 16 is that all the liquefaction cases do not match with the maximum intensities; on the other hand, they fig. 17 san carlo: left, differential settlement of a mixed r.c. and masonry building, due to huge liquefaction phenomena below part of the foundation. right, sand ejected from a water-manhole (photo of may, 20). fig. 18 road san carlo-sant’agostino: sand volcanoes aligned on a ground fissure (photo of may 21). galli p. et al. 120 fig. 19 san carlo. coseismic surficial breaks associated to liquefaction (linear ejection of sand and water). note the echelon geometry of fractures that mimic a graben-like feature (i.e., lateral spreading of the paleo-reno river ridge). buildings, roads, walls and pipelenes located above this fractures have been seriously damaged the night of may 20. fig. 20 san carlo. sand ejection inside a car-box. remarkably, that the car has been by raised by ~80 cm up to the ceiling of the box due to the powerful push of the liquefied sand below during the night of may 20. this side of the house (see fig. 17, left) has been severely damaged by differential settlement. may 2012 emilia earthquakes (mw 6, northern italy): macroseismic effects … 121 systematically follow the paths of the paleo-river beds (castaldini and raimondi, 1985), as the case of the paleo-reno, toward mirabello, of the paleo-secchia, toward cavezzo-san felice sul panaro and san possidonio, or as the case of the abandoned paleo-beds of po river, further north (san martino spino). likely, in our opinion, the sandy deposits associated to the depositional facies of river-channel s.s. are dramatically the most liquefaction susceptible among all the other alluvial sediments of the plain. therefore, as many settlements have been founded along the abandoned fluvial ridges that emerge few meters above the level of the whole po plain, this fact might represent a general risk than need to be mitigated by means of appropriate geotechnical tools, both in the 2012 mesoseismic area and elsewhere in the plain. 4. discussion and conclusions we applied the mcs scale (sieberg, 1930) during the survey of the effects induced by the 2012 emilia seismic sequence to 190 localities around the epicentres, in the provinces of mantua, rovigo, ferrara, modena and reggio emilia. the intensities were estimated by using the methodology proposed by molin (2009), which roughly quantifies the percentage of buildings affected by each of the five level of damage. in this way, as in the 2009 l’aquila earthquake (see in galli et al., 2009), we believe to have released a comprehensive intensity datapoints distribution (idd) of the earthquake which, on one hand, meets the primary purposes of the civil protection intervention (rescue and emergency planning based on real damages, living vulnerability out of consideration), and on the other can be promptly compared to the historical earthquakes, i.e. to the idd contained in the italian seismic database (e.g., dbmi11), all expressed in terms of mcs intensities. in doing this, owing both to the early onset of the mcs survey on may 20 morning, and to its intrinsic expeditiousness, we succeed in compiling the idd also for the first mainshock, which has resulted composed by 52 datapoints (tab. 4). the highest idd (hidd) for both mainshocks fits with the hangingwall of the two seismogenetic structures that, in turn, have been individuated by matching instrumental (hypocentres, interferograms, focal mechanisms) and geological (maps of the buried structures, seismic reflection profiles) data. as a matter of facts, may 20 hidd lays entirely south of the outer ferrara thrusts front, while may 29 hidd lays south of the mirandola-cavone thrust (figs. 5, 11). both mainshocks look associated to the frontal thrust rupture of each of the two mentioned structures (figs. 2-3), even though we can not exclude the involvement of the sole thrust, as suggested also by the fault dip provided by the focal mechanisms (fig. 1). on the other hand, the macroseismic epicentre of the cumulated sequence falls west to the instrumental ones, suggesting a rough rupture directivity from east toward west, at least for the may 29 shocks (fig. 11). therefore, considering 1) the entire extension of the arched, outer ferrara thrusts front and of the intermediate cavone-mirandola buried folds and thrusts (fig. 11), and 2) the historical seismicity of the same region (fig. 4), this sequence has partially filled the seismic gap existing between the earthquakes in the ferrara area to the east (i.e., 1570), and those around correggio to the west (1806, 1996), confirming the supposed residual activity of these buried structures (galli, 2005). indeed, this activity has been recently quantified by scrocca et al. (2007) at 0.15 mm/yr for the mirandola structure (late pleistocene), and this value is consistent with the amount of surface coseismic vertical uplift (11-15 cm) measured by the differential interferograms during the current earthquakes (tre, 2012). taking into account the lack of seismic events comparable to the 2012 sequence in the last ~1 kyr, or even hypothesizing that the quoted 1346 earthquake might represent a possible 2012 predecessor (i.e., the literary sources record its effects only for ferrara, and not for smaller villages), that slip rate could really represent an average value for these structures (11-15 cm every 700-1000 yr yield ~ 0.15 mm/yr), and, in particular, relatable to mw ≤ 6 earthquakes. anyway, it is worth noting that this tectonic slip rate, and its related surficial deformation, are from 10 to 50 times lower that the rough sedimentation rate in this region of the po plain. by considering the mentioned thickness of the post lgm and post late roman deposits, the sedimentary rates has grown from 1.3 to 6.7 mm/yr in the past thousands years. thus, at least in the eastern part of the plain, the supposed diversion of the rivers around the growing anticlines which some scholars claim to be an evidence of active tectonics (burrato et al., 2003) seems unreliable. conversely, it is probable that fluvial paths are here influenced by other geological/hydrogeological causes that have much higher rates. for instance, the huge general subsidence affecting wide areas of the po plain (1-5 mm/yr, with local peaks of 3-4 cm/yr; bitelli et al., 2010; carminati et al., 2010), and/or – within this subsidence the differential rates affecting the areas subtending deep synclinal (e.g., 8000 m of plioquaternary deposits ne of modena) vs shallow, suboutcropping anticlines (few hundred meters below novi di modena, concordia, mirandola, san felice sul panaro), that have been quantified at 1 mm/yr by arca and beretta (1985) for the period 1897-1957 (i.e., -4 mm/yr vs -3 mm/yr). indeed, from this point of view, the dominant geomorphic processes are not the moderate, 1-kyr spaced earthquakes, but the hundred, often catastrophic alluvial floods occurred continuatively in the past centuries in the po plain (see in cnr-sicis, 2012). living aside this specific issue, we want to evidence another aspect linked to the 2012 event. the equivalent magnitude estimated through boxer4 algorithm (i.e., the one on which the whole cpti11 is based) is, in facts, much lower than the instrumental values. on the basis of our hidd, we calculated mw 5.23 vs an instrumental mw 6.1 (or ml 5.8). probably, if we really had considered only the damage affecting the ancient houses in each villages, excluding at all not only the recent outskirts, but also the new buildings inside the oldcentres, our intensities would have been likely higher by 0.5-1 degree (n.b., not everywhere! for instance in cavezzo it would have been lower). anyway, this increase is not yet enough to rise the equivalent magnitude to the instrumental one. this “anomaly” is evidenced also by the measured acceleration peaks (e.g., 0.29 g, pga in mirandola; 0.23 g, pga in san felice sul panaro and cento; 0.25 g, pga in moglia; accelerometgalli p. et al. 122 ric data of dpc-ran), that would theoretically account for much more damage with respect to those really occurred (i.e., according to the existing regression laws, the peak acceleration in mirandola account for 9 mcs; faccioli and cauzzi, 2006). moreover, until 2004 the area affected by the current seismic sequence was not classified as seismic, and therefore was not subject to compliance with specific technical standards for construction. however, as aforementioned, most of the settlements have small old-centres with brick-masonry buildings (where damage mostly focused on high and wide structures), and vast residential outskirts, consisting of low and regular buildings (2-3 storeys), realized with reinforced composite masonry (manufactured bricks) or, rarely, in reinforced concrete. moreover, even in downtowns, the quality of ancient buildings is higher than that observed in many other areas of italian territory, such as in abruzzo (hit by the 2009 earthquake), where it is common to observe houses made with rubble stones or field stones with poor mortar (class of vulnerability a, according to ems scale). therefore, the quality of constructions and, likely, the role played by the deep alluvial deposits on filtering the earthquake frequency contents, might have concurred in mitigating the shaking effects on buildings, despite both the relative high magnitude values and the acceleration peaks. references anderlini l. and others seventeen (2012) deformazione cosismica gps in emilia (m 6.1, 20 maggio 2012). ingv report, 3 pp. arca s., beretta g.p. (1985) prima sintesi geodeticogeologica verticali del suolo nell'italia (1897-1957). bollettino di geodesia e scienze affini, 44, 125-156. asm (1570a) archivio di stato di modena, archivio segreto estense, cancelleria ducale, interno, rettori dello stato, ferrarese, b.22, lettera di giovan battista filippi al duca alfonso ii d’este, cento 21 novembre 1570. asm (1570b) archivio segreto estense, cancelleria ducale, interno, rettori dello stato, modenese, b 21, lettera di silvio bartolaio al segretario ducale giovan battista pigna, finale 22 novembre 1570. bianchi e., castellarini a., rodorigo s., vico g. (2008) i sinkholes in pianura padana. mem. descr. carta geol. d’it., 85, 409-418. bigi g., cosentino d., parotto m., sartori r., scandone p. (1992) structural model of italy, scale 1: 500.000. prog. fin. geod. quaderni de "la ricerca scientifica", cnr. 114 (3), roma. bitelli g., bonsignore f., bortone g., vittuari l. (2010) il monitoraggio della subsidenza a scala regionale in emilia-romagna. acque sotterranee, 122 (4), 9-21. burrato, p., ciucci f., valensise g. (2003) an inventory of river anomalies in the po plain, northern italy: evidence for active blind thrust faulting. ann. geophys., 46, 865-882. carminati e., scrocca d., doglioni c. (2010) compaction-induced stress variations with depth in an active anticline: northern apennines, italy. journal of geophysical research, vol. 115, b02401. doi: 10.1029/2009jb006395. cassano e., anelli l., fichera r., cappelli v. (1986) pianura padana. interpretazione integrata di dati geofisici e geologici. 73° congr soc geol it, 29 sett-4 ott, roma, pp. 27. castaldini d., raimondi s. (1985) geomorfologia dell’area di pianura padana compresa tra cento, finale emilia e s. agostino. atti soc. nat. mat. di modena, 116, 147-176. castellarin a. (2001) alps-apennines and po plainfrontal apennines relations. in: anatomy of an orogen: the apennines and adjacent mediterranean basins. dordrecht, kluwer academic publishers, 177-196. cgi (2009) carta geologica d'italia. foglio 203; poggio renatico. ispra. servizio geologico d'italia. ente realizzatore: regione emilia-romagna. scala 1: 50.000. cnr-sicis (2012) sistema informativo sulle catastrofi idrologiche, progetto avi catalogo delle informazioni sugli eventi di piena, http://wwwdb.gndci. cnr.it/php2/avi/. de canini l., di pasquale g., orsini g., colozza r., galli p., marcucci a., milana g., molin d., pugliese a. (1997) ricognizione degli effetti del sisma del 15 ottobre 1996 in provincia di reggio emilia. dipartimento dei servizi tecnici nazionali, servizio sismico nazionale, rapporto tecnico ssn/rt/ 97/4, pp. 191. dpc (2012) classificazione sismica al 2012. recepimento da parte delle regioni e delle provincie autonome dell’ordinanza pcm 20 marzo 2003, n. 3274. dipartimento della protezione civile, http:// www.protezionecivile.gov.it/resources/cms/docum ents/class2012_02prov.pdf. faccioli e, cauzzi c. (2006) macroseismic intensities for seismic scenarios estimated from instrumentally based correlations. in proceedings of the first european conference on earthquake engineering and seismology (a joint event of the 13th ecee & 30th general assembly of the esc), ginevra, 3-8 settembre 2006, cd-rom. fioravante v. (2008) associazione intercomunale alto ferrarrese, comuni di bondeno, cento, mirabello, poggio renatico, sant’agostino, vigarano mainarda, relazione geotecnica sismica, università di ferrara, 74 pp. galli p. (1991) liquefazione storica di terreni sabbiosi durante i passati terremoti. prog.cga-6241, ratcga-0023, ismes roma, pp. 29. galli p. (2000) new empirical relationships between magnitude and distance for liquefaction. tectonophysics, 324, 169-187. galli p. (2005) i terremoti del gennaio 1117. ipotesi di un epicentro nel cremonese. il quaternario, 18, 87-100. galli p., camassi r., azzaro r., bernardini f., castenetto s., molin d., peronace e., rossi a., vecchi m., tertulliani a. (2009) il terremoto aquilano del 6 aprile 2009: rilievo macrosismico, effetti di superficie ed implicazioni sismotettoniche. il quaternario, 22, 235-246. galli p., ferreli l. (1995) a methodological approach for historical liquefaction researches. in: serva l., slemmons b. (eds): perspectives in paleoseismology. association of engineering geologists, special publication, 6, 36-48. may 2012 emilia earthquakes (mw 6, northern italy): macroseismic effects … 123 galli p., meloni a. (1993) nuovo catalogo nazionale dei processi di liquefazione avvenuti in occasione dei terremoti storici in italia. il quaternario, 6, 271-292. gasperini p., bernardini f., valensise g., boschi e. (1999) defining seismogenic sources from historical felt reports. bull. seism soc. am., 89, 94-110. algorithm available on: http://ibogfs.df.unibo.it/user 2/paolo/www/paolo.html. giacomo da marano (xiv sec.) cronaca inedita di ferrara estense dal 1298 al 1412, in: bollettino statistico del comune di ferrara, 56-58, 1929-1931. giovanni da bazzano (xv sec.) chronicon mutinense, t. casini (ed.), in: rerum italicarum scriptores, 2a ed., 15(4). gruppo di lavoro liquefazione (2012) carta degli effetti di liquefazione osservati dopo i terremoti del 20 e 29 maggio 2012, http://geo.regione.emilia-romagna.it/ gstatico/documenti/liq2012/mappa_liquefazioni _01.pdf. grünthal g. (1998) european macroseismic scale 1998 (ems-98). european seismological commission, subcommission on engineering seismology, working group macroseismic scales. conseil de l'europe, cahiers du centre européen de géodynamique et de séismologie, 15, luxembourg. iside working group ingv (2012) italian seismological instrumental and parametric database: http:// iside.rm.ingv.it. ismes (1985) studi e indagini per l'accertamento dell’idoneità tecnica delle aree suscettibili di insediamento di impianti nucleari per le regioni piemonte, lombardia e puglia: indagini di sismica storica. rapporti tecnici predisposti per enel da ismes-sga, roma. locati m., camassi r., stucchi m. (2011) dbmi11, the 2011 version of the italian macroseismic database. milano, bologna, http://emidius.mi.ingv.it/ dbmi11. marzola m. (1976) per la storia della chiesa ferrarese nel secolo 16 (1497-1590), 2,torino. massucci a., molin d., tertulliani a. (1996) terremoto di reggio nell’emilia del 15 ottobre 1996. rilevamento macrosismico preliminare. protezione civile, relazione riservata, roma, pp. 5. molin d. (2003) considerazioni sull’eventuale adozione in italia della scala macrosismica europea (ems 1998). atti del 22° convegno nazionale gngts, isbn/issn:88-900385-9-4, 06.21, pp. 11. molin d. (2009) rilievo macrosismico in emergenza. rapporto interno dipartimento della protezione civile; ufficio iii valutazione, prevenzione e mitigazione del rischio sismico, 13 pp. patacca e., sartori r., scandone p. (1990) tyrrhenian basin and apenninic arcs; kinematic relations since late tortonian times. mem. soc. geol. ital., 45, 425451. pierdominici s., heidbach o. (2012) stress field of italy. mean stress orientation at different depths and wave-length of stress patter. tectonophysics, 532535, doi: 10.1016/j.tecto.2012.02.018. pieri m., groppi g. (1981) subsurface geological structure of the po plain (italy). c.n.r., prog. fin. geodinamica, 414, 1-13. postpischl d. (1985) atlas of isoseismal maps of italian earthquakes, quaderni della ricerca scientifica, 114, 2a, roma, 164 pp. qrcmt (2012) quick regional centroid moment tensor, ingv-bologna, http://autorcmt.bo.ingv.it/ quicks. html. rovida a., camassi r., gasperini p., stucchi m. (2011) cpti11, versione 2011 del catalogo parametrico dei terremoti italiani. milano, bologna, http:// emidius.mi.ingv.it/cpti. scrocca d., carminati e., doglioni c., marcantoni d. (2007) slab retreat and active shortening along the central-northern apennines. in: “thrust belts and foreland basins: from fold kinematics to hydrocarbon systems”, lacombe o., lavè j., roure f., verges l. (eds.), frontiers in earth sciences, 471-487. serpelloni e., anzidei m., baldi p., casula g., galvini a. (2005) crustal velocity and strain-rate fields in italy and surrounding regions: new results from the analysis of permanent and non-permanent gps networks. geophys. j. int., 161, 861-880. sieberg a. (1930) geologie der erdbeben. handboch der geophysic, 4, 552-554. spakman w. (1990) tomographic images of the upper mantle below central europe and the mediterranean. terra nova, 2, 542–553. doi: 10.1111/j.13653121.1990.tb00119.x. stucchi m., albini p. (2000) quanti terremoti abbiamo perso nell’ultimo millennio? in: galadini, meletti & rebez (editors). le ricerche del gndt nel campo della pericolosità sismica (1996-1999), cnrgndt, 333-343. tdmt (2012) time domain moment tensor, ingvcentro nazionale terremoti, http://cnt.rm.ingv.it/ tdmt.html. tre (2012) primo interferogramma co-sismico in banda c del terremoto in emilia romagna, http:// www.treuropa.com/home/newsedeventi/news/tab id/59/newsid988/258/default.aspx. youd t.l. (1977) discussion of ‘brief review of liquefaction during earthquakes in japan’ by e. kuribayashi and f. tatsuoka, 1975, in soil and foundations 15, 81-92. soil and foundations 17, 82-85. ms. received: july 13, 2012 final text received: july 20, 2012 << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /all /binding /left /calgrayprofile (gray gamma 2.2) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /warning /compatibilitylevel 1.4 /compressobjects /tags /compresspages true /convertimagestoindexed true /passthroughjpegimages true /createjobticket false /defaultrenderingintent /default /detectblends true /detectcurves 0.1000 /colorconversionstrategy /leavecolorunchanged /dothumbnails false /embedallfonts true /embedopentype false /parseiccprofilesincomments true /embedjoboptions true /dscreportinglevel 0 /emitdscwarnings true /endpage -1 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<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> /ita (utilizzare queste impostazioni per creare documenti adobe pdf adatti per visualizzare e stampare documenti aziendali in modo affidabile. i documenti pdf creati possono essere aperti con acrobat e adobe reader 5.0 e versioni successive.) /enu (use these settings to create adobe pdf documents suitable for reliable viewing and printing of business documents. created pdf documents can be opened with acrobat and adobe reader 5.0 and later.) >> >> setdistillerparams << /hwresolution [1200 1200] /pagesize [396.850 566.929] >> setpagedevice amq32(1) 57-72 boretto et al.pub oxygen stable isotope analyses on ameghinomya antiqua shells: a promising tool for palaeoenvironmental reconstruction along the quaternary patagonian argentina coast? gabriella boretto 1, 2, ilaria consoloni 3, gisela arianna morán 1, 2, eleonora regattieri 4, sandra gordillo 1, 2, enrique fucks 5, giovanni zanchetta 3, luigi dallai 6 1 universidad nacional de córdoba. facultad de ciencias exactas, físicas y naturales. córdoba, argentina. 2 cicterra-conicet, córdoba, argentina. 3 dipartimento di scienze della terra, università di pisa, pisa, italy. 4 igag-cnr, rome, italy. 5 facultad de ciencias naturales y museo, universidad nacional de la plata, la plata, argentina. 6 igg-cnr, pisa, italy. corresponding author: g. boretto <gmboretto@gmail.com> abstract: there are only a few data concerning the quaternary climate fluctuations in the marine environments of the atlantic patagonian coast. in this regard, the aragonitic shell of the ameghinomya antiqua bivalve offers the possibility to study the climate variability and the seasonal cycles of sea water temperature in the region at different geological times. we compared oxygen isotopic profiles along the shell-growth axis on four well-preserved a. antiqua bivalves collected from marine coastal deposits of marine isotope stage (mis) 7, mis 5, holocene (7.284 ±140 yr cal bp), and from the present-day active beach of bahía bustamante (patagonia argentina). shell ontogeny was determined through the annual growth lines recorded along the external region of the shell, and was also verified by cross-section analyses. the fossil bivalves were around 15 years old, while the present day shell was 10 years old. when the modern climatic data available are compared, the higher δ18oshell values represent the cold season, while the lower δ18oshell values indicate the warm season. the δ18oshell ranges indicate different environmental conditions and seasonal temperature variations between specimens. by assuming, a constant δ18ow calculated with the limited environmental data available, superficial seawater temperatures are estimated from the specimens. these paleotemperatures may overestimate water temperatures, and shell formation seems to occur with an offset from expected oxygen isotopic equilibrium with the water in which they lived. meanwhile, a. antiqua shells are suitable bioarchives for the comparison of seasonal patterns throughout the quaternary, thus constituting another proxy for the evaluation of paleoclimatic and paleoenvironmental changes in the patagonia region. keywords: oxygen isotopes, bivalve shells, ameghinomya antiqua, quaternary, seasonality, patagonia. available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 32 (1), 2019, 57 72 1. introduction it is well known that mollusk shells can preserve important data on the biology of the organisms and on the environmental conditions present during their growth (jones & gould, 1999; richardson, 2001; goodwin et al., 2010; among others). growth rate and time are controlled by many factors, including temperature (jones et al., 1989; schöne et al., 2002), salinity (koike, 1980), age (jones et al., 1989), reproductive cycle (sato, 1995), tidal cycles, intertidal positions (ohno, 1989; goodwin et al., 2001) and nutrient availability (schöne et al., 2003; goodwin et al., 2010). however, temperature seems to be the main factor controlling the intraannual growth rate in most of the species (koike, 1980; goodwin et al., 2001; schöne et al., 2002). the oxygen and carbon stable isotope composition of marine mollusk shells has proven to be a valuable proxy for reconstruction of the environmental history and climatic conditions during the quaternary (epstein et al., 1953; rhoads & lutz, 1980; brand et al., 1987; aguirre et al., 2002; jones et al., 2005; schöne et al., 2004, 2005; watanabe et al., 2004; carré et al., 2005; miyaji et al., 2010; schöne & gillikin, 2013; gordillo et al., 2015; among others). in particular, variations in oxygen and carbon isotope ratios within the shell carbonate of mollusks have been used to track present and past annual marine temperature cycles (jones, 1983; jones et al., 1989; jones & allmon, 1995). this data can be used to assess seasonal changes (jones & allmon, 1995) and to infer productivity and marine salinity fluctuations (geary et al., 1989; goodwin et al., 2009) the isotopic profiles of marine mollusks thus have great potential for high resolution paleoenvironmental reconstruction. annual seasonal cycles in oxygen and carbon isotopes also provide an independent method for ontogenic age determination of mollusks whose life span and growth rates may be unknown (jones & allmon, 1995). patagonian raised coastal deposits contain rich mollusk faunal assemblages, which are potentially useful for the detailed paleoclimatic reconstruction of periods of sea-level highstand as far back as mis 11 https://doi.org/10.26382/amq.2019.06 58 boretto g. et al. (schellmann & radtke, 2000, 2007, 2010; pappalardo et al., 2015; zanchetta et al., 2012, 2014; bini et al., 2018). the shells of the aragonitic bivalve ameghinomya antiqua are particularly suitable to investigate the environmental conditions of this region during the quaternary, owing to the excellent preservation of the fossil shells and to their suitability for geometric morphometric analysis (boretto, 2013; boretto et al., 2014). in this paper, conceived as a pilot study, we discuss oxygen isotopic composition along the external shell growth axis of fossil and modern a. antiqua shells collected at bahía bustamante in patagonia, argentina (fig. 1), including the present day active beach as well as the deposits from the holocene and marine isotope stages (mis) 5 and 7. the aim of this work is to establish whether oxygen stable isotope analyses on a. antiqua shells can indicate local environmental conditions in the different interglacial periods and, if this is the case, to evaluate the seasonal conditions during different interglacial periods. 2. geographical and geological settings the geology of bahía bustamante (45°13'-44°54's and 66°50'-65°48'w; san jorge gulf, argentina; fig. 1) is dominated by quaternary marine coastal deposits, organized in a succession of beach ridges and marine terraces composed of accumulated sand, gravel and mollusk shells (feruglio, 1950; cionchi, 1987,1988; rutter et. al., 1989, 1990; schellmann & radtke, 2000, 2007, 2010; aguirre et al., 2005; ardolino et al., 2008; isola et al., 2011; boretto, 2013; boretto et al., 2014). these deposits, which extend mostly parallel to the current coastline, were dated by schellmann & radtke (2000, 2010) through electron spin resonance and spectrometric 230th/234u methods at mis 7 (15-23 m a.s.l.) and mis 5 (10-19 m a.s.l.), and through radiocarbon dating for the holocene (3-10 m a.s.l.). past landforms and deposits are particularly well-preserved because weathering processes are very limited (isola et al., 2011) as a result of the arid environment of the area during the quaternary. these deposits mostly overlie the marifil complex, which consists of jurassic rhyolites, ignimbrites and volcanoclastic conglomerates (sciutto et al., 2000; lema et al., 2001; isola et al., 2011). the local climate is characterized by two main meteorological features: constant dry winds blowing strongly from the west, and low precipitation (<300 mm/ yr) (coronato et al., 2008). the moderate thermal amplitude allows the growth of a sparse cover of grass and shrubby vegetation, consistent with the semiarid climate of patagonia. wave action and sea level oscillations are the main morphoclimatic agents responsible for the past and present landscapes. a high-energy system with fig. 1 modified from boretto et al. (2014). a. location of the study area. b. pleistocene (mis 5) deposits. c. holocene (7.284±140 yr bp) deposit. d. present-day shell accumulation on an active beach. 59 oxygen stable isotope analyses on ameghinomya antiqua shells: a promising tool ... intense storms and a macrotidal (>4 m) regime dominate the area (isla & bujaleswsky, 2008), thus representing the main morphodynamic agents for shaping of the coastal zone. 3. bivalve ameghinomya antiqua ecology. this species is a benthic bivalve typical of the magellanic region (balech & ehrlich, 2008), which extends along the atlantic ocean from 34° s to the beagle channel (54° s) and along the pacific ocean as far as callao (12°77’ s) in peru (castellanos, 1967; márquez et al., 2010). it lives in the sandy soft-bottom substrate, from the shallow intertidal up to 100 m depth in temperate-cold waters (castellanos, 1967). in the patagonian area the maximum depth of this species is 60 m, and its absence at greater depths is probably associated with an increase in the fine-sediment fraction (zaixso, 1996). shell morphology. the a. antiqua shells have a typically equivalve external aspect, with a subcircular contour, prosogyrous and sub-central umbos and a strong external ligament. the external sculpture consists of fine, sometimes high, concentric lines, crossed by numerous radial grooves that are wide and flattened, giving it a general cross-linked appearance (escati peñaloza, 2005; escati peñaloza et al., 2010; zaixso & boraso, 2015). individual growth. the adult stage of bivalves is related to the size achieved by the first sexual maturity (calvo et al., 1998). a. antiqua reaches reproductive maturity at around 2 years of age, with a length of around 13-22 mm. the reproductive processes occurring in the austral winter months and the effort necessary to decrease the energy invested in growth (escati peñaloza, 2005) generate seasonal growth patterns, which cause marked annual growth rings in the winter (verdinelli et al., 1976, clasing et al., 1994). shell growth takes place during the warm spring-summer season, so that light or opaque calcium carbonate bands are deposited. dark or translucent increments are generated during the autumn-winter months, and a conspicuous mark is produced on the outer region of the shell before the end of the cold season (fig. 2) (escati peñaloza, 2005; escati peñaloza et al., 2010). the number of growth rings observed on the outer shell accumulated per year and their formation time have been studied for a. antiqua through: (1) analysis of the correspondence between internal microlines (cross sections) and external rings (andaur, 1999); (2) mark-recapture experiments (clasing et al., 1994); (3) monitoring the edge of the shell during the growing season (reyes et al., 1992); and (4) other methods of age determination and growth parameter estimation (urban, 1994, 1996; escati peñaloza, 2005; escati peñaloza et al., 2010). the results of these studies clearly indicate that the use of external growth rings observed in the outer shell region is suitable to correctly determine the ontogeny and to estimate the growth rate of this species (escati peñaloza, 2005). 4. material and methods 4.1 field sampling adult specimens of a. antiqua were collected in the area of bahía bustamante (fig. 1). fossil specimens from holocene and pleistocene beach ridges were taken from randomly chosen bulk samples (50 cm3) during field trips in january-february 2011. radiocarbon dating of the holocene beach ridge yielded an age of 6758 yrs bp (schellmann & radtke, 2000, 2010) with a calibrated age of 7.284 ±140 yrs cal bp (reimer et al., 2013). the sampled mis 5 and mis 7 deposits were dated with electron spin resonance (esr) by schellmann & radtke (2000), and were assigned ages of 111 ±19 ka and 220 ±22 ka, respectively. for comparison with fossil clam data, present day shells were randomly sampled by means of a 1x1 m quadrant (fig. 1d) from the present active beach. these modern samples had preserved hinges and remains of organic matter, which indicated that their death had taken place only a short time before collection. 4.2 preparation of the a. antiqua samples in the laboratory a total of four shells, one for each age from the present day (active beach), holocene, mis 5 and mis 7 deposits, were selected for this study (table 1). the bivalves chosen had well-preserved paired valves to avoid individual shells, which could have experienced postmortem transport, thus minimizing any erosion and reworked material from older units. they were whole and well-preserved; the growth rings on the external shell region were clearly discernable with the naked eye. the shells were chosen arbitrarily and were ultrasonically cleaned in deionized water for 10 minutes, so as to tab. 1 list of ameghinomya antiqua specimens collected for oxygen isotopes. the sampled sites were defined stratigraphically and dated by *schellmann & radtke (2000): **esr method, ***14c method. the pleistocene samples are correlated with the respective marine isotopic stage (mis). remove any sediment and organic matter and were then dried in an oven at 60°c. x-ray diffraction analyses of powder from specimens indicated that the shell material was virtually pure aragonitic (100% aragonite) (consoloni, 2013). 4.2.1 ontogenic age of each sample the individual age of each specimen was calculated using the method employed by escati peñaloza (2005), which consists in recording the number of growth rings that have developed along the growth axis of each shell (fig. 2). to facilitate the identification of the rings, the outer shell surfaces were polished to show the reticular sculpture and to expose the clear growth marks. escati peñaloza (2005) considered these annual bands to be well-defined, sharply delineated and dark in color, forming conspicuous, easily identifiable concentric rings. however, cross-sections of the growth lines were also taken to ensure accuracy. each selected shell was externally strengthened with a layer of epoxy resin to protect it from breakage. the shells were then crosssectioned (perpendicular to the growth lines) by using a low-speed precision saw (phoenix alpha, buehler), and were polished by using a manual grinder-polisher (buehler) and sand paper with the three different grain sizes 15, 10 and 5 μm. one unstained cross-section was employed for growth pattern analysis, and digital images were taken through a leica s6d greenough stereo microscope with a 6.3:1 zoom and integrated video/photo port equipped with sectoral dark field illumination. ontogenetic age was determined by counting the annual growth increments under a stereo microscope (leica s6d). 4.2.2 isotopic analyses of shells for stable oxygen isotope analyses of shell carbonate (δ18oshell), a total of 206 samples were taken between the umbo and the external ventral margin (area of latest growth) in order to obtain calcium carbonate powder. a dremel microdrill and a 0.5 mm bit were employed to drill the external shells in ontogenetic sequence (fig. 2). each powdered caco3 sample weighed approximately 0.15 mg. after each new drilling, the tools and the shell were cleaned by using compressed air to prevent contamination. the consecutive drill holes were spaced approximately 1 mm apart to achieve a high resolution and a continuous seasonal record. this drilling method on the external region of the shell was used on mollusks by different authors, such as killingley (1981), jones (1983), krantz et al. (1984), jones & allmon (1995), bojar et al. (2004), yan et al. (2009), jolivet et al. (2015), peharda et al. (2017), among others. although other authors suggest that shell cross-section drilling is more suitable (jones et al., 1989; goodwin et al., 2001; schöne et al., 2002, 2003, 2004; yan et al. 2012), we believe that the methodology applied for the purpose of this study is appropriate since the ontogeny is calculated on the basis of the external growth rings correlating with the internal microlines analyzed in cross-sections by other authors (clasing et al., 1994; andaur, 1999; escati peñaloza, 2005). stable isotope analysis was carried out using a gas bench ii (thermo scientific) coupled to a delta xp irms (finnigan) at the institute of geosciences and earth resources of the italian national research council (igg -cnr) in pisa (italy). carbonate samples of ca. 0.15 mg of caco3 were dissolved in h3po4 (100%) for an hour at 70°c. all the results reported are relative to the v-pdb international standard. sample results were corrected by using the international standard nbs-18 and a set of 3 internal standards, previously calibrated according to the international standards nbs-18 and nbs-19 (negri et al., 2015). analytical uncertainty for δ18o was 0.13‰. owing to the sampling difficulties in the marginal sector of the shell, the last few years of the specimens were not recorded in the isotopic data. 4.3 environmental variables: sea surface temperature (sst), salinity (sss), isotopic water composition (δ18ow) according to the period of collection and annual counting, the present day specimen lived between the years 2000 and 2010. monthly records of sea surface temperature (sst) in bahía bustamante were obtained from nasa earth data by the moderate resolution imaging spectroradiometer (modis) (http:/ / giovanni.gsfc.nasa.gov) (fig. 6). direct in situ measurement was not available, so we compared the recorded sst with information accessed from a marine station near the study area belonging to the argentine naval hydrography service (http://www.hidro.gov.ar/ceado/ef/ inventar.asp). sea surface salinity (sss) data for the specific study area could not be accessed from the modis satellite, but values related to this environmental variable were obtained from previous studies in the region. fernández et al. (2007) measured an sss value of 33,362 psus during the autumn-winter season and louge et al. (2004) recorded an sss value of 33,766 psus for the summer season. in shallow water environments, sst, sss and isotopic water composition (δ18ow) can undergo seasonal and inter-annual variations (e.g. yan et al., 2012). the only δ18ow data available in bahía bustamante are provided by consoloni (2013), who reported a summer (february 2011) value of -0.38‰. the annual mean δ18ow value (-0.50‰) was taken from the global seawater oxygen-18 database (http://data.giss.nasa.gov/ o18data/) and calculated from the gridded data, using salinity and po4* to infer δ18ow values. more recently, rubo et al. (2018) measured δ18ow and salinity (psu) along different places located to the south of the study area in patagonia, taking into account this database (https://data.mendeley.com/datasets/sz2v8ztb38/1) and the values measured by meredith et al. (1999) for the atlantic ocean. the δ18ow for the region was reconstructed by applying the method proposed by colonese et al. (2011, 2012) and yan et al. (2012) (see section 4.4). 4.4 paleotemperatures the δ18oshell value mostly depends on changes in temperature and in the oxygen isotope composition of the ambient water (δ18ow) (e.g. colonese et al., 2011, 2012; yan et al., 2012). if the δ18ow value is known and 60 boretto g. et al. if the shells were formed in oxygen isotopic equilibrium (or near) with the water in which they lived, then the water temperature can be reliably reconstructed from δ18oshell (epstein et al., 1953). for reconstruction of the water temperatures from δ18oshell values (tδ18o) of a. antiqua, we used the grossman & ku (1986) paleothermometry equation with a pdb to v-smow scale correction of -0.27‰ modified by dettman et al. (1999). the corrected equation is: tδ18o (°c) = 20.34 4.34 [δ18oshell (δ 18owater-0.27)] (1) in shallow water environments, salinity and, hence, 61 fig. 2 shells sampled along the growth axis for isotopic analyses. scale bar =10 mm. a, a’: present day specimen; b, b': holocene specimen; c, c': mis 5 specimen; d, d': mis 7 specimen. δ18ow may underlie seasonal and interannual variations that can hamper precise temperature estimates based on δ18oshell values, unless the δ18ow value is closely monitored. since no long-term observations were available for the study area, the δ18ow signature was calculated from sea surface salinity (sss), considering the annual average of the 33.564 psu value and of the δ18ow values measured along the region. with this aim, a local freshwater mixing line was constructed for this area, based on the dataset of the nasa goddard institute for space studies (giss) (meredith, 1999; schmidt, 1999; bigg & rohling, 2000) and on the data provided by consoloni (2013), yan et al. (2012), m. sol bayer oxygen stable isotope analyses on ameghinomya antiqua shells: a promising tool ... (pers. comm to gb., 2016) and rubo et al. (2018). the respective equation is as follows (fig. 3). (appendix): δ18ow ‰ = 0.2749*sss 9.6492 (2) to compute water paleotemperatures from δ18oshell (tδ18o), we assumed a δ18ow value of 0.42‰ based on long-term average salinity (see section 4.3) and eq. (2). therefore, this value is considered for the calculation of paleotemperatures for the present day and holocene (7,284 bp) specimens, assuming that no significant changes in the isotopic composition of sea water occurred in the last 7.000 yrs, when global sea level was mainly stable (lambeck et al., 2014). by comparison, the annual mean δ18ow value of -0.50‰ was also used to estimate temperature on the present day sample. as the δ18ow composition for the mis 5 and mis 7 for the study area was unknown, we considered the δ18ow re 62 fig. 3 a. freshwater mixing line constructed from regional δ18owater and sea surface salinity (sss) data (appendix). b. region from which the aforementioned data derives. fig. 4 oxygen isotopic profiles measured on a. antiqua shells. a. present day specimen. b. holocene specimen. c. mis 5 specimen. d. mis 7 specimen. boretto g. et al. and negative -0.30‰ average values associated with the colder and warmer months. the maximum value is +1.57‰ and the minimum is -1.47‰; the δ18oshell annual mean value is 0.31‰, while δ18oshell =3.04‰, and there is a seasonal average temperature spread of ca. 13.2°c (fig. 4a). the reconstructed ssts for present day a. antiqua were calculated by using both the δ18ow of -0.42‰ for the region and the average value δ18ow of -0.50‰ obtained from the global seawater oxygen-18 database. the results (fig. 5) broadly agree with the mean interannual data recorded. the ssts predicted present some offset with respect to the measured sst available for the area. for instance, the warmest value (more than 23°c) estimated for spring-summer 2004 is higher than the maximum temperature recorded for that year. the relationship between the δ18oshell data, the constructed for the global ocean by shakun et al. (2015). according to shakun et al. (2015) average values of the mis5 was of δ18ow of -0.45‰ and for the mis 7 was of -0.31‰ v-smow. the mis 5-mis 7 paleotemperature values should therefore be treated with caution, since no precise data can be provided for regional changes in salinity for the different interglacial periods. 5. results 5.1 present day shell this specimen lived until january 2011 and the ontogenetic study indicates an age of 10 years (fig. 2). the shell length is 38 mm, and the first year represents 26% of the total, with 64% of growth concentrated during the first 3 years. intra-annual δ18oshell presents clear seasonal fluctuations (table 2), with positive +0.69‰ 63 fig. 5 predicted ssts from the δ18oshell of the present day a. antiqua specimen. ssts were computed by using δ18ow of -0.50‰ (mean value from the global seawater oxygen-18 database) and the δ18ow values of -0.42‰ obtained from eq. (2) for the region. estimated ssts fell into the range of measured ssts (grey band), and the maximum sst was highest in one exceptional year. fig. 6 temporal alignment of δ18oshell and predicted ssts from present day a. antiqua specimen. upper panel: δ18oshell values arranged by daily increments; the specimen is 10 years old; the last growth line belongs to the cold season 2010. the isotopic data recorded are related to the first 6 years. lower panel: temporally aligned predicted ssts (δ18oshell) and recorded ssts from the modis satellite data and from the sss measured by louge et al. (2004). the oxygen isotope-derived temperatures seem to have overestimated the recorded data. reconstructed and recorded temperatures fitted well, but not perfectly, because there was an offset that could be linked to limited environmental data and to more modern specimen monitoring. oxygen stable isotope analyses on ameghinomya antiqua shells: a promising tool ... recorded sst in the study area during the specimen’s lifetime and the predicted sst is shown in figure 6. according to this alignment, the annual growth increments were formed between the spring-summer season of the following year, and the annual minimum and maximum temperatures were recorded in july-august and january, respectively. the δ18oshell profile (counting the positive peaks) shows six cycles, which seems to represent six years. on the basis of this observation we can conclude that annual growth lines (shell portion representing the time interval of strongly reduced or even halted shell growth) were deposited between the cold seasons (autumn-winter) (fig. 6). the predicted inter-annual mean sst was 16°c, while the sst recorded by the modis satellite was 12.5°c, thus presenting an average offset of 3.5°c. tδ18o was overestimated with respect to the sst, corresponding to an average δ18oshell of -0.80‰, with a minimum of 11°c sst predicted from the shell and a maximum of 24°c. the maximum and minimum average temperatures recorded by modis were 17°c and 8°c respectively, and the monthly mean sst ranged from 16°c in summer (dec-jan-feb-mar) to 9°c in winter (jun-jul-ag-sep), with an intra-annual variability of around 7°c. seasonal periodicity was observed in the isotopic profile of the valve, and therefore was also present in the predicted ssts of this data, associated with the environmental data recorded in bahía bustamante. with respect to the offset, it should be noted that there was little discrepancy between the predicted and the recorded data, and that cyclicality in the isotopic record was maintained throughout the lifetime of the specimen. these preliminary results indicated that δ18oshell can record seasonal changes in ssts and in δ18ow. some offset with measured data are present, but this can also related to the poor record of the environmental data. it would be interesting to deepen and confirm these preliminary studies with more data obtained from the patagonian coast and through appropriate data monitoring. with this analysis in mind, we considered this species useful for reconstructing seasonal patterns in quaternary coastal sites. 5.2 a. antiqua fossil specimens the holocene specimen lived for 15 years (fig. 2). the shell length was 50 mm. the first and second years represented 50% of the increments; from the third to the fifth years, this percentage was 21%, and then the increments decreased considerably. this sample had δ18oshell values that indicated a strong seasonality (fig. 4b). the extreme values were -0.67‰ and 1.53‰ (table 2), which were associated with the warmest and coldest seasons respectively, while a mean inter-annual (i.e. averaged over all years) value was 0.43‰. the warm season (ws) mean value was -0.18‰, and the cold season (cs) mean value was 1.03‰. it was possible to distinguish 4 well-marked positive peaks (1.31, 1.53, 1.50, 1.12‰) and 3 clearly negative points (-0.67, -0.64, -0.31‰), with the δ18o at 2.2‰, and the seasonal temperature variation at ca. 9.5°c (assuming no changes in sea water isotopic composition). if we consider the δ18ow value of -0.42‰ over time, we could 64 fig. 7 predicted ssts from the a. antiqua specimens through eq. (2), taking into account the estimated δ18ow for each time interval in the region. apply eq. (2) to estimate ssts from this specimen. in this case, the predicted annual mean sst was 15°c, with a maximum of 20°c and a minimum of 11°c (fig. 7). the mis 5 sample lived for 14 years (fig. 2). the shell length was 58 mm, and the first to the fourth years of life produced 73% of the increments (with 37% corresponding to the first year). in the isotopic profiles recorded for this specimen, the minimum δ18oshell value was 0.98‰ and the maximum was 1.97‰ (table 2), with an annual mean value of 0.55‰. overall, the δ18oshell curve behaviour tended to be positive, with no prominent peaks, and was recorded for 8 years (fig. 4c). the δ18oshell ws mean value was 0.02‰, and the cs mean value was 1.13‰; the δ18oshell was 2.95‰ and the estimated seasonal temperature variation was 13°c. the number of growth rings in the mis 7 specimen indicated an age of 15 years (fig. 2), and the shell length was 50 mm. as in the other samples, the increments developed significantly during the first four years of life (ca. 74%). the δ18oshell values for the mis 7 specimen (fig. 4d) ranged from -0.96‰ to 1.56‰, and the annual mean value was 0.13‰ (table 2). the ws mean value was -0.36‰, while the cs mean value was 0.78‰. in the oxygen isotope curve, 3 peaks stood out as well-marked, with values higher than > 0.50‰ (1.56, 0.86, 0.92‰). these would suggest a further temperature decrease in the cold season during these years, taking into consideration the average annual value. the δ18o was 2.52‰, and the average seasonal temperature variation recorded in this sample was ca. 11°c. the paleotemperatures reconstructed from pleistocene specimens were affected by a lack of detailed estimations of the isotopic composition of the seawater. in this sense, shakun et al, (2015) provided a dataset of 18ow for the global ocean during the 800 kyr glacialinterglacial cycles through different records. this data could be improved with more geographical datapoints and variable measurements. according to shakun et al. (2015) δ18ow values the annual predicted mean sst (δ18ow=-0.45‰) to be 15°c, the maximum recorded 22° c and the minimum 9°c for the mis 5 specimen. the predicted values for the mis 7 sample were: an annual predicted mean sst (δ18ow=-0.31‰) of 17°c, a maximum of 22°c and a minimum of around 11°c. boretto g. et al. 65 fig. 9 last-appearance dates for megafauna from the argentine pampas region, using only robust dates from previous papers and the new dates. the horizontal dashed line indicates a consistent archeological signal. the dotted horizontal line indicates the earliest occupation evidence or minimal human activity. the gray boxes indicate the dates obtained from the literature, the red boxes indicate radiocarbon data of south american horses, and the yellow line is the average of these. black boxes indicate the new dates and the green line is the average of these. the gray band denotes the timing of younger dryas cooling in the argentine pampas region (hajdas et al., 2003; krohling & iriondo, 1999) (modified from prado & alberdi, 2017). tab. 2 sequential δ18oshell values of present day a. antiqua specimen and fossil shells from bahía bustamante. oxygen stable isotope analyses on ameghinomya antiqua shells: a promising tool ... 6. discussion according to these preliminary results, a. antiqua shells from patagonia should be suitable to the use of oxygen isotopes studies for evaluating marine environmental changes in the argentine patagonian region during the middle-late quaternary. our analyses indicate that a. antiqua has annual growth rates that ensure sufficient seasonal isotopic resolution. it is interesting to note the decreasing growth rate after 3-4 years in the four specimens, hence, the annual rings accumulate in the outer marginal zone of the shell. as discussed by schöne (2008), mollusk shells record the environment only during growth; therefore, growth lines indicate a slowdown or complete cessation of shell production. accordingly, the oxygen isotope values in the outer part of the shell would not be as reliable as in the rest of the valve. data show that a. antiqua grows faster during summer and at a slow rate during winter, and it records a seasonal temperature amplitude recorded in the δ18oshell. in this respect, rubo et al. (2018) suggested that the isotope-based climate reconstructions for leukoma antiqua (which could be considered as synonymous of a. antiqua, pérez et al., 2013) will be limited until the 15 years of life because growth rates are sharply reduced. therefore, the isotope samples in the external marginal zone of the shell can not be considered particularly informative in terms of stable isotopes. although it would be necessary to increase the number of samples of each deposit so as to better interpret the environment some general consideration can be made on the basis of the obtained data. in general, in the southern hemisphere, the timing and character of quaternary interglacial climate is a combination of global and regional/local events. in particular, the interglacial environment in the patagonia region seems to be associated with: (1) changes in the westerlies and in the position of the southern border of the semipermanent atlantic and pacific anticyclones and (2) the intertropical convergence zone (itcz) (compagnucci, 2011), the brazil-malvinas confluence zones (laprida et al., 2011), and westerlies (atmospheric changes) coupled with the antarctic circumpolar current (acc, oceanographic changes) (lamy et al., 2010; fletcher & moreno, 2011). however, patterns of climate variability on a multicentennial to millennial scale have been linked to the onset of the modern state of the enso (lamy et al., 2002; lamy & de pol-holz, 2013). in addition, the topographical and bathymetrical settings of the san jorge gulf result in complex local oceanographic conditions characterized by interacting water masses (krock et al., 2015).  the present day a. antiqua shell. the shell length of this specimen is smaller than that of the fossil samples, and its ontogeny (10 years) is also lower in relation to the other shells. the δ18oshell profile has a lower δ18oshell (-1.47‰) value in the warmest months compared to the fossil specimens, which marks an unusual year in relation to the δ18oshell mean recorded (0.31‰). the maximum δ18o is 1.57‰, and δ18o is 3.04‰, which corresponds to a change of ca. 13°c in the seasonal temperature estimate of sea water. these results can be compared to the oxygen isotope analyses performed by rubo et al. (2018) on a. antiqua modern shells from caleta olivia, southern san jorge gulf, where the mean δ18oshell is -0.15‰ (considering nine samples, appendix), showing an interannual variation between -0.82‰ and 1.04‰. as previously discussed there are some offsets between the predicted sst and the sst recorded in bahía bustamante; tδ18o was overestimated since it presented a mean offset of 3.5° c, corresponding to an average of δ18oshell -0.80‰. similarly, rubo et al. (2018) estimated ssts from a. antiqua; the results indicated that multi-year temperature curves computed from δ18oshell values overestimated instrumental temperatures. these authors recommended to adjust the δ18oshell values of -0.9 ±0.3‰ from expected oxygen isotopic equilibrium with the water of the shell formation to calculate past water temperatures. therefore, on the basis of this correction, the predicted sst of our present day shell shows values closer to those recorded by modis data in the region (appendix). another patagonia species was analyzed throughout the oxygen isotopic shell profile. bayer et al. (2013) indicated an interannual variation between -0.66‰ and 1.56‰ for amiantis purpurata modern shells from the san matías gulf (northern patagonia, argentina), and recorded a range of δ18oshell= 2.22‰. the predicted seasonal sst was within the range of the sst measured in bahía bustamante.  the holocene (7.284 ±140 yr bp) a. antiqua shell. the δ18oshell profile clearly indicates the presence of marked seasonality. the annual mean δ 18oshell is 0.43‰, the predicted mean sst is 15°c, and the seasonal change is around 10°c. considering the offset adjustment proposed by rubo et al. (2018), the estimated mean sst is 9°c, the minimum value is 4°c and the maximum value is 14°c. if we compared this data with the present day sample, the ssts would be lower. according to the dating of the outcrop where this sample was collected (schellmann & radtke, 2000), the oxygen isotope profile would correspond to the climatic data analyzed by other studies for the early holocene in the patagonian region (renssen et al., 2005; wagner et al., 2007; compagnucci, 2011; among others). this indicates that the average annual temperatures would not have been higher between 9.000 and 6.000 yrs bp, since warmer conditions were recorded between 6.000 and 3.000 yrs bp, when the summer temperatures would have reached 3°c more than the estimated average temperatures for the preindustrial period (renssen et al., 2005).  the mis 5 a. antiqua shell. seasonality in this specimen, which is the largest of the specimens analyzed, is evident throughout the 14 years. the seasonal variation recorded was around δ18oshell = 2.95‰, resembling the one obtained for the present day shell. the interglacial mis 5e has been documented as one the warmest from the late quaternary (shackleton et al., 66 boretto g. et al. 2003; sidall et al., 2007; negri et al., 2015; shakun et al., 2015, among others). however, the positive trend of the oxygen curve indicates colder seasonal temperature cycles compared to the data from the other δ18o profiles. as there is not δ18ow data available for the san jorge gulf during this interglacial period, we used the δ18ow = -0.45‰ v-smow estimated by shakun et al. (2015) for the global ocean. the annual average paleotemperature was around 15°c, with a minimum of 9°c and a maximum of 21°c. however, by applying the offset adjustment (rubo et al. 2018), the annual mean sst was 11°c, while the extreme values were 5°c and 18°c. on the other hand, if we calculate the paleotemperatures considering the estimated δ18ow = 1.2‰ v-smow obtained by wefer et al. (1996) for the south atlantic ocean during the interglacial-glacial pleistocene cycles, the annual average paleotemperature was around 18°c, with a minimum of 12°c and a maximum of 25°c. these temperatures are particularly high if compared to the present day condition. from these calculations we can speculate that a global estimation of sea water isotopic composition is unable to provide a correct picture of the local conditions. indeed, changes in local salinity might have occurred in the malvinas (falkland) current, owing to the very different general astronomical configuration of the mis5 compared to the holocene (berger & loutre, 1991). in addition, when ponce et al. (2011) modelled the patagonian atlantic coast, they concluded that bahía bustamante would not have been formed as such, and the study area would have been linked to the open sea and therefore would have been directly affected by the ocean circulation conditions occurring in the south atlantic. the bay would have originated after the last glacial maximum (lgm) (ponce et al., 2011). in this respect, the following tentative explanation is proposed. the brazil (bc, warm) and malvinas (mc, cold) confluence zone (bmcz) currently stands at 29°-49° s (stramma & england, 1999; laprida et al., 2011). laprida et al. (2011) reconstructed the possible displacement of the bmcz during the middle pleistocene glacial periods mis 8 and mis 6. such displacement would have moved about 10° north with respect to the current position. we can hypothesize that during the interglacial cycles the bmcz would have moved further south than its current position on account of the important latitudinal changes occurred during the pleistocene interglacials (wefer et al., 1996), especially during mis5e, thus causing strong positive anomalies in the sst in the patagonian region. when the bc and the mc collide, the flow veers sharply southeastward into the south atlantic, forming a large area of intense surface mixing of tropical and subantarctic waters characterized by the formation of meanders, eddies and filaments (bianchi et al., 1993; wilson & rees, 2000; laprida et al., 2011). the bc dominates the mc and forces it into a cyclonic loop before both currents flow to the southeast, forming a broad subtropical convergence zone, the bmcz (gordon, 1989; peterson & stramma, 1991; laprida et al., 2011). the bc would thus cause an increase in δ18o of seawater caused by changes in salinity associated with evaporation processes connected, in turn, to a rise in sst (stanley, 1989; murray-wallace & belperio, 1991; williams et al., 1994; brown & lomolino, 1995; zazo, 1999; martinez et al., 2001). this δ18o behaviour is observed nowadays in warm tropical and subtropical regions (krantz et al., 1987; aguirre et al, 2001; lécuyer et al., 2004; azzoug et al., 2012). moreover, bayer et al. (2013) and bayer (2014) recorded a δ18o seasonal variation of around δ18o = 2.92‰ in amiantis pupurata shells from the san matías gulf.this value is similar to that obtained in a. antiqua shells, ranging from -0.93‰ to 0.85‰. these authors also proposed a higher sst than that prevailing today.  the mis 7 a. antiqua shell. the δ18oshell profile of the specimen shows defined seasonal cycles, as in the other samples, with a mean δ18oshell value of 0.13‰. its ontogeny is 15 years, similar to that of the other fossil samples. the oxygen isotope data would suggest a further drop in temperature during the cold seasons, taking into consideration the annual average value. marked negative peaks that probably indicate markedly warmer conditions during the warm season follow the pattern of the other samples. the paleotemperature data calculated on the global δ 18ow estimated by shakun et al. (2015) indicated a predicted mean sst of 17°c, with a minimum of around 11°c and a maximum of around 22°c. when considering the offset correction (rubo et al. 2018), the estimated ssts are: mean sst of 13°c, a minimum value of 7°c and a maximum value of 18°c. very warm values are obtained if we consider the δ18ow (1.2‰) estimated by wefer et al. (1996). the mis 7 mean δ18oshell value is the lowest observed with respect to the other samples, and even the peaks indicating the warm season are the most negative. the seasonal variation (δ18o = 2.52‰) is not as great as in the mis 5 and present day specimens. there is little knowledge of the development of this interglacial cycle in patagonia, and for this reason, the preliminary data obtained for the mis 7 sample are difficult to compare. on the basis of geometric morphometric studies boretto et al. (2014) reported that a. antiqua shells belonging to the mis 7 interglacial have shown analogies in their configuration (size and shape) with shells from the mis 5 deposits of bahía bustamante, both of which are very different in shape and size from the holocene and modern shells. 7. final remarks these preliminary oxygen isotope analyses on a. antiqua specimens conceived as exploratory study may help determine whether δ18oshell behaviour and ontogeny have a direct relationship with the environmental variables of sst, sss and δ18ow of the study area. however, to calculate the sst from the δ18oshell, it would be necessary to monitor more live specimens and to update the environmental variables (especially the annual or seasonal oxygen isotope composition of the seawater). this would help to understand the isotopic fractionation of this species along the patagonian coast. the age of a. antiqua can be determined by count 67 oxygen stable isotope analyses on ameghinomya antiqua shells: a promising tool ... ing the annual growth rings on the external shell. these conspicuous dark lines are associated with the cold season (in which the organism decreases the energy spent on growth). seasonal temperature variability was determined over the four different geological time intervals: present day, holocene (7.284 ±140 yrs bp), mis 5 and mis 7. the isotopic profiles indicated that the oxygen isotope ratio is a powerful tool for estimating the seasonal cycle during the life of a. antiqua. assuming a minor change in salinity during the different seasons the maximum seasonal variability is ca. 13°c for the present day and mis 5 specimens, and ca. 9°c and 11°c for the holocene and mis 7 respectively. if we assume a similar isotopic composition of sea water for the holocene sample, the average temperature will be similar to the one obtained for the modern sample (although in this case the warm season temperatures would have been lower). temperature estimations based on the suggested water isotopic composition of the ocean during the mis 5 and mis 7 seem to yield unrealistically high temperatures (wefer et al., 1996), while more recent estimations (shakun et al., 2015) gave significantly lower temperatures. general changes in the position of the warmer and saltier brazilian superficial current and the fresher and cooler malvinas current cannot however be ruled out for these pleistocene interglacials,. the estimated paleotemperatures for the mis 5 and mis 7 are difficult to confirm with precision because of the unknown δ18ow for the patagonian region. it would be interesting to continue this line of research and to consider a. antiqua fossil shells as potential proxies for paleoenvironmental and paleoclimate reconstruction of the patagonian coast during the quaternary. acknowledgments this research has been partially funded by the ministry of italian university and research (miur) prin 2008 project: “the patagonian coastal deposits as natural archives of the sea-level changes and paleoclimate of the southern hemisphere during the quaternary: a contribution to evaluate future climatic scenarios” (leader g. zanchetta) and university of pisa pra 2015 (leader g. zanchetta). the authors are extremely grateful to the reviewers prof. dr. anthony fallick and dr. andré colonese for the detailed and helpful comments and suggestions provided. we also thank santiago druetta for his collaboration during the image processing phase. references aguirre m.l., zanchetta g., fallick a.e. (2002) stable isotope composition of littoridina australis from the coast of buenos aires province, argentina, during holocene climatic fluctuations. geobios, 35, 79-88. aguirre m.l., negro sirch y., richiano s. (2005) late quaternary molluscan assemblages from the coastal area of bahía bustamante (patagonia, argentina): paleoecology and paleoenvironments. journal of south american earth sciences, 20, 1332. andaur alveal c. (1999) validación y caracteri-zación de las bandas de crecimiento en las valvas de almeja venus antiqua (king & broderip, 1835) (mollusca: veneridae) a través del análisis microestructural. instituto de oceanología. ph.d. thesis, universidad de valparaíso, chile (unplub.). ardolino a., busteros a., fauqué l., franchi m., lema h. (2008) depósitos cuaternarios de las bahías bustamante y camarones, in: sitios de interés geológico de la república argentina. (eds) instituto de geología y recursos minerales, servicio geológico minero argentino (buenos aires). anales 46, ii, 705-717. azzoug m., carré m., schauer a.j. (2012) reconstructing the duration of the west african monsoon season from growth patterns and isotopic signals of shells of anadara senilis (saloum delta, senegal). palaeogeography, palaeoclimatology, palaeoecology, 346, 145-152. brand u., morrison j.o., brand n., brand e. (1987) isotopic variation in the shells of recent marine invertebrates from the canadian pacific coast. chemical geology: isotope geoscience section, 65, 137-145. balech e., ehrlich m.d. (2008) esquema biogeográfico del mar argentino. revista de investigacuón y desarrollo pesquero, 19, 45-75. bayer m.s., brey t., beierlein l., gordillo s. (2013) late quaternary climatic variability in northern patagonia argentina information from modern and fossil shells of amiantis purpurata (bivalvia, veneridae). third international sclerochronology conference. caernarfon, wales. 85 p. bayer m.s. (2014) interpretación paleoambiental de concentraciones fósiles y actuales de amiantis purpurata (lamarck) (bivalvia) del cuaternario de río negro, argentina: tafonomía, paleoecología y reconstrucción paleobiogeográfica y paleoclimática. ph.d. thesis, universidad nacional de córdoba, argentina (unplub.). berger a., loutre m.f. (1991) insolation values for the climate of the last 10 million years. quaternary science reviews, 10, 297-317. bianchi a.a., giulivi c.f., piola a.r. (1993) mixing in the brazil-malvinas confluence. deep-sea research, 40, 1345-1358. bigg g.r., rohling e.j. (2000) an oxygen isotope data set for marine water. journal of geophysical research, 105, 8527-8535. bini m., isola i., zanchetta g., pappalardo m., ribolini a., ragaini l., baroni c., boretto g., fucks e., morigi c., salvatore m.c., bassi d., marzaioli f., terrasi f. (2018) mid-holocene relative sea-level changes along atlantic patagonia: new data from camarones, chubut, argentina. the holocene, 28, 56-64. bojar a.v. hiden h., fenninger a., neubauer f. (2004) middle miocene seasonal temperature changes in the styrian basin, austria, as recorded by the isotopic composition of pectinid and brachiopod shells. palaeogeography, palaeoclimatology, palaeoecology, 203, 95-105. boretto g.m. (2013) evidencias multi-proxy vinculadas 68 boretto g. et al. con los cambios ambientales durante el pleistoceno medio-tardío y holoceno en la zona costera de chubut, patagonia argentina. ph.d. thesis, universidad nacional de córdoba, argentina (unplub.). boretto g.m., baranzelli m.c., gordillo s., consoloni i., zanchetta g., morán g. (2014) shell morphometric variations in a patagonian argentina clam (ameghinomya antiqua) from the mid-pleistocene (mis 7) to the present. quaternary international, 352, 48-58. brown j., lomolino m., (1995) biogeography. second ed. sinauer associates, masssachusetts. carré m., bentaleb i., blamart d., ogle n., cardenas f., zeballos s., kalin r.m., ortlieb, l. fontugne m. (2005) stable isotopes and sclerochronology of the bivalve mesodesma donacium: potential application to peruvian paleoceanographic reconstructions. palaeogeography, palaeoclimatology, palaeoecology, 228, 4-25. calvo j., morriconi e., orler p.m. (1998) estrategias reproductivas de moluscos bivalvos y equinoideos, in: el mar argentino y sus recursos pesqueros, vol.2. eds. boschi, e. instituto nacional de investigación y desarrollo pesquero, mar del plata, pp 10-42. castellanos z.j.a. (1967) catálogo de los moluscos marinos bonaerenses. anales de la comisión de investigación científica de la provincia de buenos aires (cic) 8, 1-365. cionchi j.l. (1987) depósitos marinos cuaternarios de bahía bustamante, provincia del chubut. revista de la asociación geológica argentina, 42, 61-72. cionchi j.l. (1988) geomorfología de la bahía bustamante y zonas adyacentes. revista de la asociación geológica argentina, 43, 51-62. clasing e., brey t., stead r., navarro j., asencio g. (1994) population dynamics of venus antiqua (bivalvia: veneracea) in the bahía yaldad, isla de chiloé, southern chile. journal of experimental marine biology and ecology, 177, 171-186. compagnucci r.h. (2011) atmospheric circulation over patagonia from the jurassic to present: a review through proxy data and climatic modelling scenarios. biological journal of the linnean society, 103, 229-249. colonese a.c., camarós e., verdún e., estévez j., giralt s., rejas m. (2011) integrated archaeozoological research of shell middens: new insights into hunter-gatherer-fisher coastal exploitation in tierra del fuego. the journal of island and coastal archaeology, 6, 235-254. colonese a.c., verdún-castelló e., álvarez m., godino i.b., zurro d., salvatelli l. (2012) oxygen isotopic composition of limpet shells from the beagle channel: implications for seasonal studies in shell middens of tierra del fuego. journal of archaeological science, 39, 1738-1748. consoloni i. (2013) reconstruction of paleoenvironments and paleoclimate during the last and present interglacials over the patagonian coast (argentina), with particular reference to the shell geochemistry". ph.d. thesis, università di pisa, italia (unplub.). https://etd.adm.unipi.it/t/etd-12022013-103055/ coronato a., coronato f., mazzoni e., vázquez m. (2008) the physical geography of patagonia and tierra del fuego in: rabassa, j. the late cenozoic of patagonia and tierra del fuego, pp. 18-28. crowley t.j, north g.r. (1999) paleoclimatology. oxford: oxford university press. dettman d.l., reische a.k., lohmann k.c. (1999) controls on the stable isotope composition of seasonal growth bands in aragonitic fresh-water bivalves (unionidae). geochimica et cosmochimica acta, 63, 1049-1057. epstein s., buchsbaum r., lowenstam h.a., urey h.c. (1953) revised carbonate-water isotopic temperature scale. geol. soc. amer. bull., 64, 1315-1326. escati peñaloza g. (2005) variación espacial en el crecimiento individual de la almeja rayada, ameghinomya antiqua, en el golfo san josé. thesis, universidad nacional de la patagonia “san juan bosco”, sede pto. madryn, chubut, argentina (unplub.). escati peñaloza, g., parma a.m., orensanz j.m. (2010) analysis of longitudinal growth increment data using mixed-effects models: individual and spatial variability in a clam. fisheries research, 105, 91101. fernández m., cucchi colleoni d., roux a., marcos á., fernández e. (2007) caracterización físicoquímica del sistema bentónico en el sector sur del golfo san jorge, argentina. revista de biología marina y oceanografía, 42, 177-192. feruglio e. (1950) descripción geológica de la patagonia. división general de yacimientos petrolíferos fiscales (buenos aires), 3, 74-196. fletcher m.s., moreno p.i. (2011) zonally symmetric changes in the strength and position of the southern westerlies drove atmospheric co2 variations over the past 14 ky. geology, 39, 419-422. geary d.h., rich j.a., valley j.w., baker k. (1989) stable isotopic evidence of salinity change: influence on the evolution of melanopsid gastropods in the late miocene pannonian basin. geology, 17, 981-985. goodwin d.h., flessa k.w., schöne b.r., dettman d.l. (2001) cross-calibration of daily growth increments, stable isotope variation, and temperature in the gulf of california bivalve mollusk chione cortezi: implications for paleoenvironmental analysis. palaios, 16, 387-398. goodwin d.h., paul p., wissink c.l. (2009) mogrofungen: a numerical model for reconstructing intra-annual growth rates of bivalve molluscs. palaeogeography, palaeoclimatology, palaeoecology, 276, 47-55. goodwin d.h., cohen a.c., roopnarine p.d. (2010) forensics on the half shell: a sclerochronological investigation of a modern biological invasion in san francisco bay, united states. palaios, 25, 742-753. gordillo s., brey t., beyer k., lomovasky b.j. (2015) climatic and environmental changes during the middle to late holocene in southern south ameri 69 oxygen stable isotope analyses on ameghinomya antiqua shells: a promising tool ... ca: a sclerochronological approach using the bivalve retrotapes exalbidus (dillwyn) from the beagle channel. quaternary international, 377, 83-90. gordon a.l. (1989) brazil-malvinas confluence-1984. deep-sea research, 36, 359-384. grossman e.l., ku t.l. (1986) oxygen and carbon isotopic fractionation in biogenic aragonite: temperature effects. chemical geology, 59, 59-74. isola i., bini m., ribolini a., pappalardo m., consoloni i., fucks e., boretto g., ragaini l., zanchetta g. (2011) geomorphologic map of northeastern sector of san jorge gulf (chubut, argentina). journal of maps, 7, 476-485. isla f.i., bujalesky g.g. (2008) coastal geology and morphology of patagonia and the fuegian archipelago. developments in quaternary sciences, 11, 227-239. issar a.s. (2003) the driving force behind the cold climate spells during the holocene. holocene and late vistulian paleogeography and paleohydrology. polska akademia nauk, prace geograficzne, 189, 291-297. jones d.s. (1983) sclerochronology: reading the record of the molluscan shell. am. sci. 71, 384-391. jones d.s., arthur m.a., allard d.j. (1989) sclerochronological records of temperature and growth from shells of mercenaria mercenaria from narragansett bay rhode island. marine biology, 102, 225-234. jones d.s., allmon w.d. (1995) records of upwelling, seasonality and growth in stable-isotope profiles of pliocene mollusk shells from florida. lethaia, 28, 61-74. jones d.s., gould s.j. (1999) direct measurement of age in fossil gryphaea: the solution to a classic problem in heterochrony. paleobiology, 25,158187. jones d.s., quitmyer i.r., andrus c.f.t. (2005) oxygen isotopic evidence for greater seasonality in holocene shells of donax variabilis from florida. palaeogeography, palaeoclimatology, palaeoecolology, 228, 96-108. jolivet a., chauvaud l., huchette s., legoff c., thébault j., nasreddine k., schöne b.r., clavier j. (2015) the ormer (haliotis tuberculata): a new, promising paleoclimatic tool. palaeogeography, palaeoclimatology, palaeoecology, 427, 3240. killingley j.s. (1981) seasonality of mollusk collecting determined from o18 profiles of midden shells. american antiquity, 152-158. koike h. (1980) seasonal dating by growth-line counting of the clam, meretrix lusoria, in: bulletin, vol. 18. the university museum, the university of tokyo, pp. 1.104. krantz d.e., jones d.s., williams d.f. (1984) growth rates of the sea scallop, placopecten magellanicus, determined from the l8o/l6o record in shell calcite. biological bulletin, 167, 186-199. krantz d.e., williams d.f., jones d.s. (1987) ecological and paleoenvironmental information using stable isotope profiles from living and fossil molluscs. palaeogeography, palaeoclimatology, palaeoecology, 58, 249-266. krock b., borel c.m., barrera f., tillmann u., fabro e., almandoz g.o., ferrario m., garzón cardona j., koch b.p., alonso c., lara r. (2015) analysis of the hydrographic conditions and cyst beds in the san jorge gulf, argentina, that favor dinoflagellate population development including toxigenic species and their toxins. journal of marine systems, 148, 86-100. lambeck k., rouby h., purcell a., sun y., sambridge m. (2014) sea level and global ice volumes from the last glacial maximum to the holocene. proc. natl. acad. sci., 111, 15296-15303. laprida c., chapori n.g., chiessi c.m., violante r.a., watanabe s., totah v. (2011) middle pleistocene sea surface temperature in the brazil-malvinas confluence zone: paleoceanographic implications based on planktonic foraminifera. micropaleontology, 183-194. lécuyer c., reynard b., martineau f. (2004) stable isotope fractionation between mollusc shells and marine waters from martinique island. chemical geology, 213, 293-305. lema h., busteros a., franchi m., parisi c., marquéz m., ardolino a. (2001) hoja geológica 4566-ii y iv, camarones. boletín del servicio geológico nacional, 261, 1-46. louge e., reta r., santos b.a., hernandez d.r. (2004) variaciones interanuales (1995-2000) de la temperatura y la salinidad registradas en los meses de enero en el golfo san jorge y aguas adyacentes (43° s-47° s). rev. invest. desarr. pesq., 16, 27-42. lamy f., rühlemann c., hebbeln d., wefer g. (2002) high-and low-latitude climate control on the position of the southern peru-chile current during the holocene. paleoceanography, 17(2). lamy f., kilian r., arz h.w., francois j. p., kaiser j., prange m., steinke t. (2010) holocene changes in the position and intensity of the southern westerly wind belt. nature geoscience, 3, 695-699. lamy f., de pol-holz r. (2013) postglacial south pacific. the encyclopedia of quaternary science, 3, 73-85. martinez s., ubilla m., verde m., perea d., roja a., guerequiz r., piñeiro g. (2001) paleoecology and geochronology of uruguayan coastal marine pleistocene deposits. quaternary research, 55, 246-254. márquez f., robledo j., escati peñaloza g., van der molen s. (2010) use of different geometric morphometrics tools for the discrimination of phenotypic stocks of the striped clam ameghinomya antiqua (veneridae) in north patagonia, argentina. fisheries research, 101, 127-131. meredith m.p., grose k.e., mcdonagh e.l., heywood k.j., frew r.d., dennis p.f. (1999) distribution of oxygen isotopes in the water masses of drake passage and the south atlantic. journal of geophysical research, 104(c9), 20949-20962. miyaji t., tanabe k., matsushima y., sato s., yokoyama y., matsuzaki h. (2010) response of daily and annual shell growth patterns of the intertidal 70 boretto g. et al. bivalve phacosoma japonicum to holocene coastal climate change in japan. palaeogeography, palaeoclimatology, palaeoecology, 286, 107120. murray-wallace c., belperio a. (1991) the last interglacial shoreline in australiaa review. quaternary science reviews, 10, 441-461. negri a., amorosi a., antonioli f., bertini a., florindo f., lurcock p.c. marabini s., mastronuzzi g., regattieri e., rossi v., scarponi d., taviani m., zanchetta g., vai g. (2015) a potential global boundary stratotype section and point (gssp) for the tarentian stage, upper pleistocene, from the taranto area (italy): results and future perspectives. quaternary international, 383, 145-157. ohno t. (1989) paleotidel characteristics determined by micro-growth patterns in bivalves. paleontology, 32, 237-263. pappalardo m., aguirre m., bini m., consoloni i., fucks e., hellstrom j.c., isola i., ribolini a., zanchetta g. (2015) coastal landscape evolution and sealevel change: a case study from central patagonia (argentina). z. geomorph., 52, 145-172. peharda m., thébault j., markulin k., schöne b. r., janeković i., chauvaud l. (2017) contrasting shell growth strategies in two mediterranean bivalves revealed by oxygen-isotope ratio geochemistry: the case of pecten jacobaeus and glycymeris pilosa. chemical geology doi: 10.1016/j.chemgeo.2017.09.029 pérez d.e., del río c. j., nielsen s.n. (2013) sistemática y filogenia del género ameghinomya ihering, 1907 (bivalvia: chioninae) del cenozoico de argentina y chile. ameghiniana, 50, 354-375. peterson r.g., stramma l. (1991) upper-level circulation in the south atlantic ocean. progress in oceanography, 26, 1-73. ponce j.f., rabassa j., coronato a., borromei a.m. (2011) palaeogeographical evolution of the atlantic coast of pampa and patagonia from the last glacial maximum to the middle holocene. biological journal of the linean society, 103, 363-379. renssen h., goosse h., fichefet t., masson-delmotte v., koç n. (2005) holocene climate evolution in the high-latitude southern hemisphere simulated by a coupled atmosphere-sea ice-oceanvegetation model. the holocene, 15, 951-964. reimer p.j., bard e., bayliss a., beck j.w., blackwell p.g., bronk ramsey c., grootes p.m. (2013) intcal13 and marine13 radiocarbon age calibration curves 0-50,000 years cal bp. radiocarbon, 55(4), 1869-1887. reyes a., arias e., rojas c., barahona e., lozada e., sepúlveda a., carmona a. (1992) diagnóstico de las principales pesquerías nacionales 1991. estado de situación y perspectivas del recurso. pesquerías bentónicas iii, iv, x región. corfo ifop sgi ifop 92/6, pp. 8-55. rhoads d.c., lutz r.a. (1980) skeletal growth of aquatic organisms. biological records of environmental change. plenum press, new york and london. richardson c.a. (2001) molluscs as archive of environmental change. oceanogr mar biol. annu rev, 39, 103-164. rozanski k., araguás-araguás l., gonfiantini r. (1993) isotopic patterns in modern global precipitation. climate change in continental isotopic records, 78,1-36. rubo s., aguirre m. l., richiano s. m., medina r. a., schöne, b. r. (2018) leukoma antiqua (bivalvia) -a high-resolution marine paleoclimate archive for southern south america? palaeogeography, palaeoclimatology, palaeoecology, 505, 398-409. rutter n., schnack e., del río j., fasano j., isla f., rudtke u. (1989) correlation and dating of quaternary littoral zones along the patagonian coast, argentina. quaternary science reviews, 8, 213234. rutter n., radtke u., schnack j. (1990) comparison of esr and amino acid data in correlating and dating quaternary shorelines along the patagonian coast, argentina. journal of coastal research, 6, 391-411. sato s. (1995) spawning periodicity and shell microgrowth patterns of the venerid bivalve phacosoma joponicum (reeve, 1850). veliger, 38, 61-72. schellmann g., radtke u. (2000) esr dating of stratigraphically well-constrained marine terraces along the patagonian atlantic coast (argentina). quaternary international, 68-71, 261-273. schellmann g., radtke u. (2007) neue befunde zur verbreitung und chronostratigraphischen gliederung holozäner k üstenterrassen an der mittelund südpatagonischen atlantikküste (argentinien) zeugnisse holozäner meeresspiegelveränderungen. bamberg. geogr. schr., 22, 191. schellmann g., radtke u. (2010) timing and magnitude of holocene sea-level changes along the middle and south patagonian atlantic coast derived from beach ridge systems, littoral terraces and valley-mouth terraces. earth-science reviews, 103, 1-30. schmidt g.a., bigg g.r., rohling e.j. (1999) global seawater oxygen-18 database. http://www.giss.nasa.gov/data/o18/data/ sciutto j.c., césari o., escribano v., pezzuchi h. (2000) hoja geológica 4566-iii. comodoro rivadavia, provincia de chubut, istituto de geológia y recursos minerales boletín del servicio geológico minero argentino, 244, 1-53. schöne b.r, lega j., flessa k.w., goodwin d.h., dettman d.l. (2002) reconstructing daily temperatures from growth rates of the intertidal bivalve mollusk chione cortezi (nortern gulf of california, mexico). palaeogeography, palaeoclimatology, palaeoecology, 184, 131-146. schöne b.r., oschmann w., rössler j., castro a.d.f., houk s.d., kröncke i., dunca e. (2003) north atlantic oscillation dynamics recorded in shells of a long-lived bivalve mollusk. geology, 31, 10371040. schöne b.r., dunca e., mutvei h., norlund u. (2004) a 217-year record of summer air temperature re 71 oxygen stable isotope analyses on ameghinomya antiqua shells: a promising tool ... constructed from freshwater pearl mussels. quaternary science reviews 23, 1803-1816. schöne b.r., fiebig j., pfeiffer m., gleh r., hickson j., johnson a.l.a., dreyer w., oschmann w. (2005) climate records from a bivalved methuselah (arctica islandica, mollusca; iceland). palaeogeography, palaeoclimatology, palaeoecology, 228, 130-148. schöne b.r., gillikin d.p. (2013) unraveling environmental histories from skeletal diaries-advances in sclerochronology. palaeogeography, palaeoclimatology, palaeoecology, 373, 1-5. shackleton n., sánchez-goñi m.a., paillerc d., lancelot y. (2003) marine isotope substage 5e and the eemian interglacial. global and planetary change, 36, 151-155. shakun j.d., clark p.u., he f., lifton n.a., liu z., ottobliesner b. l. (2015) regional and global forcing of glacier retreat during the last deglaciation. nature communications, 6, 8059. sidall m., chapell j., potter e.k. (2007) eustatic sea level during past interglacial, in: sirrocko, f., claussen, m., sánchez goñi, m.f., litt, t. (eds.) the climate of past interglacials, elsevier, developments in quaternary science, 7, 75-93. stanley s. (1989) earth and life through time, second ed. freeman and company, new york. stramma l., england m. (1999) on the water masses and mean circulation of the south atlantic ocean.journal of geophysical research, 104, 20863-20883. urban j.h. (1994) adaptations of six infaunal bivalve species of chile: coexistence resulting from differences in morphology, burrowing depth and substrate preference. archive of fishery and marine research, 42, 183-193. urban j.h. (1996) population dynamics of the bivalves venus antiqua, tagelus dombeii and ensis macha from chile at 36°s. journal of shellfish research, 3, 719-727. verdinelli m.a., schuldt m. (1976) consideraciones preliminares sobre aspectos de la dinámica poblacional y reproductiva de la almeja rayada (ameghinomya antiqua, king-chionidae) en punta loma, golfo nuevo-chubut. universidad nacional de la plata, facultad de ciencias naturales y museo. revista del museo de la plata. tomo xii, sección zoología n° 119. issn 0372-4638, 183-202. wagner s., widmann m., jones j., haberzettl t., lücke a., mayr c., ohlendorf c., schäbitz f., zolitschka b. (2007) transient simulations, empirical reconstructions and forcing mechanisms for the midholocene hydrological climate in southern patagonia. climate dynamics, 29,333-355. watanabe t., suzuki a., kawahata h., kan h., ogawa s. (2004) a 60-year isotopic record from a midholocene fossil giant clam (tridacna gigas) in the ryukyu islands: physiological and paleoclimatic implications. palaeogeography, palaeoclimatology, palaeoecology, 212, 343-354. wefer g., berger w.h., bickert t., donner b, fischer g., kemle-von mücke1 s., meinecke g., müller p.j., mulitza s., niebler h.s., pätzold j., schmidt h., schneider r.r., segl m. (1996) late quaternary surface water circulation of the south atlantic: the stable isotope record and implications for heat transport and productivity. in: berge w.h., wefer g., siedler g. eds.,the south atlantic: present and past circulation. berlin. springer verlag., 461502. williams m., dunkerley d., de deccker p., kershaw a., stokes t. (1994) quaternary environments. edward arnold, london. wilson h.r., rees n.w. (2000) classification of mesoscale features in the brazil-falkland current confluence zone. program of oceanography, 45, 415-426. yan h., lee x., zhou h., cheng h., peng y., zhou z. (2009) stable isotope composition of the modern freshwater bivalve corbicula fluminea. geochemical journal, 43, 379-387. yan l., schöne b.r., arkhipkin a. (2012) eurhomalea exalbida (bivalvia): a reliable recorder of climate in southern south america? palaeogeography, palaeoclimatology, palaeoecology, 250-252, 91100. zaixso h.e. (1996) asociaciones de moluscos bentónicos submareales del golfo san josé y sur del golfo san matías (chubut, argentina). physis (buenos aires), sección a, 54, 1-21. zaixso h.e., boraso de zaixso a. (2015) recursos biológicos bentónicos: la zona costera patagónica argentina. 1st ed. comodoro rivadavia: universitaria de la patagonia edupa (argentina). zanchetta g., consoloni i., isola i., pappalardo m., ribolini a., aguirre m., fucks e., baneschi i., bini m., ragaini l., terrasi f. (2012) new insights on the holocene marine transgression in the bahía camarones (chubut, argentina). italian journal of geosciences, 131, 19-31. zanchetta g., bini m., isola i., pappalardo m., ribolini a., consoloni i., boretto g., fucks e., ragaini l., terrasi f. (2014) middle-to late-holocene relative sea-level changes at puerto deseado (patagonia, argentina). the holocene, 24, 307-317. zazo c. (1999) interglacial sea levels. quaternary international, 55, 101-113. 72 ms. received: september 22, 2018 final text received: april 26, 2019 boretto g. et al. sess 1_160211.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 first recovery of marine quaternary deposits from geognostic boreholes of the coastal plain of marina di campo (elba island): preliminary results maurizio d’orefice1, luca foresi2 & roberto graciotti1 1ispra – servizio geologico d’italia, roma 2dipartimento di scienze geologiche, università di siena, siena  corresponding author: m. d’orefice <maurizio.dorefice@isprambiente.it> abstract: d’orefice m. et al., first recovery of marine quaternary deposits from geognostic boreholes of the coastal plain of marina di campo (elba island): preliminary results. (it issn 0394-3356, 2011). here we describe the preliminary results deriving from the analysis of the s2 geognostic borehole, which was drilled near the town of marina di campo (elba island). starting from a ground level at 1.29 m above the sea level, 25 m of quaternary deposits have been cored. these deposits are probably related to the last glacial-eustatic cycle. in particular, the lower part of the borehole is characterized by gravel and sandy-silt sediments typical of a fluvial environment. they settled during a low-stand phase of the last glacial maximum. these deposits are unconformably covered by coastal marine sands, sandy-silts and biocalcarenites (between -11.90 m and -5.20 m from the ground level) that were ascribed to the last sea level rise. the upper part of the geognostic survey is characterized by dark and plastic organic clays (from -5.20 m to the top). the basal clays are still marine (an age of 4.36÷3.81 ky cal bp has been obtained by radiocarbon dating), whereas those of the intermediate part are brackish (3.97÷3.45 ky cal bp). in the upper part we found clays that settled in a freshwater environment. riassunto: d’orefice m. et al., primi depositi quaternari marini rinvenuti nei sondaggi geognostici effettuati nella piana costiera di marina di campo (isola d’elba): risultati preliminari. (it issn 0394-3356, 2011). nella presente nota vengono descritti i risultati preliminari delle analisi condotte sulle carote prelevate nel sondaggio s2, realizzato alle spalle del centro abitato di marina di campo (isola d’elba). il sondaggio, spintosi sino alla profondità di -25,00 m dal piano campagna (p.c.), ha attraversato terreni quaternari in gran parte riferibili all’ultimo ciclo glacioeustatico. in particolare, la metà inferiore del sondaggio ha intercettato depositi ghiaiosi e sabbioso-limosi d’ambiente fluviale depostisi nel corso di una fase di basso stazionamento del livello marino attribuibile all’ultimo massimo glaciale. questi depositi passano superiormente (tra -11,90 e -5,20 m dal p.c.), con contatto netto erosivo, a sabbie, limi sabbiosi e biocalcareniti di chiara origine marina, attribuibili all’ultima risalita eustatica del livello del mare. la porzione superiore del sondaggio (da -5,20 m sino al p.c.) è composta da argille scure organiche plastiche. tali argille sono d’ambiente ancora marino nella loro parte basale (età radiometrica intorno ai 4,36÷3,81 ky cal bp), poi lagunare salmastro nel tratto intermedio (3,97÷3,45 ky cal bp) ed infine d’acqua dolce nella parte superiore. key words: quaternary geology, geognostic boreholes, marine deposits, marina di campo (elba island). parole chiave: geologia del quaternario, sondaggi geognostici, depositi marini, marina di campo (isola d’elba). in the small area of the elba island, the presence of a considerable variety of lithotypes, ranging from paleozoic to miocene, contrasts with the almost total absence of marine neogene and quaternary deposits (barberi et al., 1969). only few outcrops of uncertain marine origin are reported by mazzanti (1983) and centamore et al. (1988). yet, neogene and quaternary marine units extensively outcrop in the nearby island of pianosa (foresi et al., 2000; graciotti et al. 2002-2003) and along the tuscan coast (mazzanti, 1983). as a part of the geomorphological survey of the elba island (one project at a scale 1:50.000), six shallow continuous-core boreholes (< 30 m) were drilled in order to characterize the deposits of the main coastal plains. among them, four boreholes were drilled in the plain of marina di campo (central-southern elba), one near magazzini (central-northern elba) and the last one close to the locality of s. giovanni (central-northern elba). the sedimentological, micropaleontological (foraminifers and ostracods) and palynological analysis of many samples is ongoing. currently, 20 radiometric dating analyses were carried out using the technique of mass spectrometry (ams). other dating analyses are planned for the near future. the s2 borehole [25 m coring interval, from 1.29 m asl (above sea level) to 23.71 m bsl (below sea level)] is the most interesting. it is located just west of the coastal dune on which stands the marina di campo town, and records quaternary sediments of marine environment between 3.31 m bsl and 10.61 m bsl. for the first time, the presence of marine deposits of quaternary age is documented for certain on the elba island. the lower part of the borehole, from 25 m to 11.90 m bgl (below ground level) is mainly characterized by coarse gravel beds alternating with silty-clayey sands (fig. 1). the gravels are sub-angular, heterometric (ranging from some millimeters to a 29 31 30 maximum of 8 cm), heterogeneous (they derived from monzogranitic, porphyric and arenitic rocks), and are supported by a silty-sandy matrix. the gravel beds have an average thickness of about 150 cm, while the silty-clayey sands beds are 20÷230 cm thick. the finer levels are sometimes characterized by oxidized sandy laminae. no fossils were recovered in the lower interval of the borehole. starting from 11.90 m bgl, the coarse deposits of the lower part are unconformably covered by fine sands (80 cm thick). the contact is sharp and erosive. the sands pass up to matrix supported gravel beds (20 cm thick), rich of siliceous and poorly elaborate centimetric clasts. laminated silty sands with ochreous levels and clayey silty fine sands (120 cm total thickness) lay above the gravels. small fragments of mollusk, foraminifera and rare rests of others marine organism were found in the intervals 11.90 m ÷ 11.10 m and 10.50 m ÷ 9.70 m bgl. the interval between 9.70 m and 5.20 m bgl is composed of a sequence of highly fossiliferous sands, sandy silts and clayey sandy silts, alternating with three levels of biocalcarenites: the first between 9.70 m and 9.40 m, the second between 8.50 and 8.40 m and the third between 7.50 m and 6.30 m bgl. the micropaleontological analysis allowed to identify an abundant organic fraction consisting of mollusks, calcareous algae, foraminifers, ostracods, echinoids, sponge spicules, bryozoans and other minor components. at 5.20 m bgl, very dark gray plastic organic clays cover the fossiliferous sands and silts. the contact between the two units is sharp. the clays contain fossil assemblages which are significantly different from bottom to top. the interval from 5.20 m to 4.60 m bgl contain mollusks, echinoids, foraminifers, ostracods and calcareous algae typical of coastal marine environment. oligotypical assemblages of brackish environment are recorded from 4.60 m to 2.40 m bgl. they are composed of mollusks, ostracods, foraminifers (ammonia tepida and nonion sp.) and characeae oogonia. the clays in the interval 2.40 m÷1.10 m bgl contain only plant debris and rare characeae oogonia. this denotes a very shallow fresh water envirnoment. two radiometric dating analyses carried out on cerastoderma shells from two levels at 4.95 m and 4.30 m bgl have provided calibrated age of 4.36÷3.81 ky bp and 3.97÷3.45 ky bp, respectively. the upper part of the borehole is characterized by barren clayey-sandy silt in the interval 1.10÷0.50 m fig. 1 – synthetic log of the s2 borehole. log sintetico del sondaggio s2. m. d’orefice et al. 31 ms. received: testo ricevuto il bgl and by 0.50 m of landfill. on the basis of sedimentological characteristics and fossil content, eight main depositional intervals can be recognized starting from the stratigraphic top (ground level). they are summarized in table 1. in conclusion, preliminary data from the s2 borehole introduces new elements to reconstruct the evolution of the quaternary plain of marina di campo, with particular attention to the last glacialeustatic cycle. new chronological, paleontological and palynological constrains will be available once the analysis of the entire set of the s2 samples and the careful examination of the stratigraphy of the other five boreholes will be complete. references barberi f., dallan l., franzini m., giglia g., innocenti f., marinelli g., raggi g., squarci p., taffi l. & trevisan l. (1969) note illustrative della carta geologica d’italia alla scala 1:100.000. foglio 126 isola d’elba. min. ind. comm. art. serv. geol. d’it., 41 pp. centamore e., dramis f. & federici p. r. (1988) superfici di spianamento relitte e vicende morfoneotettoniche dell’isola d’elba. suppl. geogr. fis. dinam. quat., 1, 155-160. foresi l. m., cornamusini g., bossio a., ferrandini j., ferrandini m., mazzanti r., mazzei r. & salvatorini g. (2000) – the miocene sedimentary succession of the pianosa island, northern tyrrhenian sea. “evoluzione geologica e geodinamica dell’appennino” in memoria del prof. g. pialli. foligno, 16-18 febbraio 2000, 155-157. graciotti r., foresi l. & pantaloni m. (2004) lineamenti geomorfologici dell’isola di pianosa. soc. tosc. scien. nat. atti serie a. mazzanti r. (1983) il punto sul quaternario della fascia costiera e dell’arcipelago di toscana. boll. soc. geol. it., 102, 419-556. depth  (m bgl) litology and depositional environment relative sea level 0.0 ÷ 0.5 landfill 0.5 ÷ 1.1 sandy clayey silt typical of fresh water environment sea level high-stand 1.1 ÷ 2.4 very dark gray plastic organic clays deposited in a very shallow brackish or freshwater environment sea-level high-stand 2.4 ÷ 4.6 very dark gray plastic organic clays deposited around 3.97÷3.45 ky cal bp in a brackish environment sea-level high-stand 4.6 ÷ 5.2 very dark gray plastic organic clays deposited around 4.36÷3.81 ky cal bp in a shallow marine environment sea-level high-stand 5.2 ÷ 9.7 sand, silty sands and biocalcarenites of marine infralittoral environment transgressive phase of post-glacial sea level rise 9.7 ÷ 11.9 sands of very shallow marine environment, with levels of gravels and silty fine sands of fluvial environment transgressive phase of post-glacial sea level rise 11.9 ÷ 25.0 gravels and sands of fluvial environment seal level low-stand of the last glacial maximum tab. 1 – main lithotypes and depositional environments recorded by s2 boreholes, associated with relative sea level change. principali litotipi e ambienti deposizionali riscontrati nel sondaggio s2, associati alle variazioni relative del livello del mare. january 10, 2011 10 gennaio 2011 first recovery of marine quaternary deposits from ... amq sr05 ghirotti et al 157-164.pub one of the hazardous neighbours of the vajont landslide: the historical m. salta rock-block slide-rock fall. monica ghirotti 1, lisa borgatti 2, gianluca marcato 3 1 department of physics and earth science, university of ferrara, ferrara, italy. 2 department of civil, chemical, environmental, and materials engineering (dicam), university of bologna, bologna, italy. 3 research institute for geo-hydrological protection, national research council of italy, padova, italy. corresponding author: m. ghirotti <monica.ghirotti@unife.it> abstract: in the vajont valley (north-eastern alps), the everlasting interactions between endogenic (tectonic, seismic, isostatic) and exogenic (glacial, slope, anthropogenic) processes have resulted in a hazardous environment. the most striking geomorphological feature of the valley is the evidence of several landslide processes of different type, age, and size. the october 1963 catastrophic landslide is undoubtedly the most notorious one. however, the pineda and salta landslide events have left enduring signatures in the landscape of the valley. in particular, the wide landslide deposit upslope casso, on the southern slope of m. salta, derives from multiple overlapping events. rock planar slides, topples, and rock falls occur since centuries, displaying a complexcomposite style of activity. nowadays, in this area, slope processes are still active and are threatening the village of casso and the visitors of the 1963 disaster site. keywords: complex historical landslide, kinematics, vajont valley, north-eastern alps, italy. � available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 33 (2), 2020, 157-164 1. introduction the vajont valley, located in the eastern italian alps in the buffer zone of the dolomites unesco world heritage site, is a left-hand tributary of piave valley. it can be considered a typical alpine valley displaying an assemblage of landforms and deposits originated mainly by glacial and fluvial processes. however, the most striking feature of the vajont valley is the diversity of landslide processes, in terms of types, sizes and ages. the valley has been prone to slope instability ever since, due to its geologic, tectonic and geomorphologic settings. among the widespread active, inactive and dormant slope instability phenomena, the most relevant in terms of geomorphological risk, long-lasting evidence in the landscape and damage are the salta, the pineda and the vajont landslides (fig. 1, 2a). the most impressive one is certainly that related to the october 1963 catastrophic event (rossato et al., 2020). nevertheless, the southern salta slope is still posing a residual risk to the downstream village of casso. the main geomorphological features of these landslides are here briefly described, focusing on the salta area for which some original geomorphological and historical data are provided. 2. geological and geomorphological setting 2.1. geology in the vajont valley the geological formations range in age from the upper triassic (dolomia principale) to the middle eocene (flysch). the erto basin is connected with the tertiary formations outcropping in the core of the sinclyne: the steep slopes sourronding the valley are ascribed either to faults or mostly to hard rocks outrcopping in the syncline flanks. the local stratigraphic series is represented in the legend of fig. 2c. however, due to the presence of the m. borgà thrust (fig. 2), in the section representative of the m. salta landslide, only the following formations outcrop: scaglia rossa (upper cretaceous-lower paleocene; ~300 m thick). it is a monotonous succession of marls and red marly limestones; the typical facies is completely lacking of resedimentation features. socchèr limestone (lower-upper cretaceous; 150 m thick). alternation of microcrystalline limestones, calcarenites and bioclastic-intraclastic calcirudites with nodules and beds of chert. vajont limestone (dogger; 450 m thick). oolitic calcarenites, massive or layered in thick beds, intercalated with decimetric layers of brown basinal micrites and intraformational breccias. igne formation (middle-upper lias; 0 150 m thick). remarkable lithological heterogeneity, it consists of alternating marls and marly limestones, organic black shales, green and red nodular limestones. soverzene formation (lower-middle lias; 600 m thick). monotonous succession of frequently dolomized grey or brown micrites, rhythmically alternating with centimetric layers of grey and yellow marls; black chert in nodules and beds. https://doi.org/10.26382/amq.2020.11 158 ghirotti m. et al. 2.2. tectonics the vajont valley follows the core of an alpine syncline (erto syncline) with an e-w to wnw-ese trending axis (riva et al., 1990) gently plunging towards the e. the erto syncline lies on the hanging wall of the belluno thrust, one of the main structures of the venetian south-vergent alps (doglioni, 1992; massironi et al., 2013) and it is paired with a frontal asymmetric structure, the belluno anticline. the northern limb of the erto syncline is reversed and stretched by the m. borgà thrust, an older thrust passively transported on the back of the belluno thrust. the regional m. borgà thrust fig. 2 a) tectonic map of the western part of the vajont valley and vajont valley landslides. labels of symbols: ce: col delle erghene fault; ctr: col tramontin fault; sa: m. salta overthrust; sp: le spesse overthrust; cvc: costa vaseicalta faults; cto: col delle tosatte fault; se: erto syncline. b) tectonic cross-section at a regional scale. legend: p tr = permian-triassic; j = jurassic; k = cretaceous, t = tertiary (modified after doglioni, 1992); c) geological section. 1a quaternary; 1b fluvial gravels filling the vajont epigenetic gorge; 1c 1963 vajont landslide deposit; 2 scaglia rossa fm. (upper cretaceous-lower paleocene); 3 cretaceous-jurassic fms. (socchér fm. sensu lato and coeval): 3c socchér fm. sensu stricto, 3d ammonitico rosso and fonzaso fms.; 4 vajont limestone (dogger); 5 igne fm. (upper liassic); 6 soverzene fm. (lower and middle liassic); 7 dolomia principale (upper triassic) (modified after riva et al., 1990; semenza & ghirotti, 2000). fig. 1 view of the vajont valley seen from east, with its main landslide accumulations concentrated in a restricted area. here, the landslides, and the geological bodies, can be viewed as elements of the memory (modified from dolomiti project srl). 159 one of the hazardous neighbours of the vajont landslide: the m. salta rock-block slide-rock fall uplifts limestone jurassic in age on top of the scaglia rossa fm. the m. borgà thrust is limited to the east, south and west by the m. salta overthrust (sa in fig. 2), which separates the jurassic formations of the thrust itself from the underlying scaglia rossa. the le spesse overthrust (sp in fig.2) runs almost parallel to sa and develops within the scaglia rossa unit for almost all its path. the tectonic element between these two lines has been interpreted as a reversed wedge of scaglia rossa, detached from the top of the series that was overtaken by the m. borgà thrust, and pushed forward during its motion. 2.3. geomorphology the main geomorphological feature of the vajont valley is the presence of several huge landslide deposits of different type, age and size, that will be described in the following sections. however, besides landslides, the valley is also rich in glacial and fluvial deposits and karst landforms (pasuto, 2017). the glacial history of the region is poorly known, since related landforms have been dismantled by subsequent slope and karst processes, especially in vajont valley. during the last glacial maximum (lgm), the hanging vajont valley was probably occupied by a local glacier merging into the main piave glacier. afterwards, the valley has been dammed several times by landslides activated during or after deglaciation (wolter et al., 2016). as a consequence, the vajont stream has been from time to time diverted northwards and southwards, probably cutting more than one persistent and deep epigenetic gorges prior to the catastrophic 1963 failure (fig. 2c). 3. landslide types and processes in the vajont valley 3.1. the neighbouring landslides the vajont landslide (northern italy) is one of the best known and most tragic examples of a natural disaster induced by human activity. the northern slope of m. toc underwent nearly 3 years of intermittent, slow slope movements, beginning at the time of the first filling of the reservoir. on the 9th october 1963 at 22:39 local time, during the third reservoir emptying, a catastrophic landslide suddenly occurred on the southern slope of the vajont dam reservoir and the whole mass collapsed into the reservoir itself. the failed mass (270 mm3 of rock) drove the water of the reservoir forward, giving rise to a wave, which overtopped the dam at a height of more than 100 m above the crest and hurtled down the vajont gorge to the piave valley floor. the flood destroyed many villages and almost 2000 people lost their lives. the slide moved a 250 m thick mass of rock some 300 to 400 m horizontally with an estimated velocity of 20 to 30 m/s, before running up and stopping against the opposite side of the vajont valley. at present, the area affected by the 1963 landslide is subject to environmental and town planning restraints. numerous initiatives have been carried out in order to keeping the memory of the catastrophic disaster alive (rossato et al., 2020). the pre-historic pineda landslide, similarly to the vajont landslide, has had a large impact on the morphology of the valley (pasuto, 2017; ghirotti et al., 2013). it has detached from the steep, bare slope on the north of m. borgà (fig. 2a). it can be defined as a translational landslide (dykes et al., 2013) which turned into a rock avalanche (esposito et al., 2015). the sliding surface is visible on the right side of the valley along a footpath that connects the villages of casso and erto, while the large accumulation is located at the base of the opposite slope. the landslide would have dammed the vajont river and mesazzo stream, with implications for river course, erosion of the landslide dam, and evolution of the valley geomorphology (esposito et al., 2015; wolter et al., 2016). the source area is currently characterized by a debris cover which is often involved in debris flow phenomena. the pineda landslide overlaps a delta sequence (topset, foreset, bottomset) of glacio�uvial origin, allowing its preservation. this delta entered an extinct glacial lake, as witnessed by laminite sequences with drop-stones. a diamictite, hypothesized to be a glacial till, locally covers the pineda landslide body (masè et al., 2004; ghirotti et al., 2013). this would point to a pre-lgm age for the pineda event. 3.2. the salta landslides the salta area is located on the northern slope of the vajont valley. active slope processes are severely threatening the small village of casso, where some tens of people live. rock and debris falls originating from the uppermost part of the southern slope of m. salta, at an elevation of about 1500 m a.s.l., can be considered the most hazardous slope process still active in the valley. in the 1960s, large boulders reached the secondary road connecting the village of casso to regional road 251. since 1990, minor rock falls have been repeatedly reported on the same slope. the most recent rock fall event occurred in 2001, when five blocks detached at 1050 m a.s.l from the scaglia rossa fm. cropping out above the village of casso, fell for about 300 m and reached the outskirts of the village (tagliavini et al., 2009). the steep accumulation of the salta landslides covers a total area of about 250,000 m2 stretching between 1250 and 850 m a.s.l. and has a volume of approximately 2.5 mm3. it is composed by abundant huge blocks, which can reach a volume of some hundreds of cubic meters. marcato et al. (2007) based on the distribution of the blocks and their dimensions, suggest that the kinematics of major past events in the southern m. salta slope can be described as rock avalanches (evans & hungr, 1993). recently, a quarry has been opened east of casso to exploit the debris materials for construction purposesto set up a retaining zone to protect the village. apart the most recent events, the wide landslide deposit upslope casso appears to be the result of multiple overlapping events, but only one of these can be dated. in a written document dating back to 1688 a landslide event occurred 14 years before is referred to. therefore, it can be dated back to 1674. moreover, in a historical map dating back to 1747 found in the archive of casso church, the two branches of the deposits are clearly visible (fig. 3): one is called “motta prima de sassi cascata dalla croda di salta” (first landslide composed by stones fallen from the m. salta), the other “motta seconda” (second landslide). the main scarp is labelled as “croda cascata in due volte”, that is scarp fallen in two different moments. it can be deduced that two different events have occurred, spreading from east to west. the scarp and the accumulation zone of the 1674 event are still evident. the depicted deposit reaches the lower sector of the slope, as it can be observed even nowadays, with two distinct lobes which reach downwards altitudes between 950 and 800 m a.s.l. (fig. 4). two minor rock fall deposits, related to small scarps outcropping just north of casso, are not represented in the historical map, meaning that they could have fallen after 1747 or that they were too small to be mapped. 160 fig. 3 a) historical map of the southern slope of m. salta dating back to 1747; b) contour of the landslide body and crown areas. fig. 4 a) geological map of the southern slope of m. salta; b) geological sections and kinematic indicators of m. salta landslides. legend: 1 m. salta landslide deposits; 2 undifferentiated quaternary deposits; 3 scaglia rossa fm.; 4 socchèr limestone fm.; 5 vajont limestone fm.; 6 igne fm.; 7 soverzene fm. ghirotti m. et al. the geomorphological evolution of the slope appears to be mostly driven by the structural setting. in particular, the m. borgà thrust is certainly the main conditioning structural element that has led to the weakening of the rock mass and has driven the subsequent slope failure (fig. 4). the emplacement of the thrust has sheared the rock and has induced intensive and pervasive brittle fracturing processes (stead et al., 2019). above the thrust zone, folded and faulted bedding planes dip steeply towards the slope free face, predisposing the rock mass to failure (fig. 4). in particular, in the upper part of the slope (2050-1700 m a.s.l.) the vajont limestones dip 30° downslope, whereas in the middle part (1700-1525 m a.s.l.) the slope is still homoclinal, but the dip increases up to 45°. in the lowermost part of the slope, the bedding is dipping into the slope. the slope is characterized by the presence of different structural and landslide scarps, distributed along tectonic discontinuities. more in detail, the first series of scarps is located around 2000 m a.s.l. and it is supposed to be the remnant of even older events of the same type and style of activity as of the 1674 event. from 1700 to 1425 m a.s.l. four orders of scarps can be found, and the latter corresponds to the crown of the 1674 landslide (fig. 4a). it displays a semicircular shape and is delimited by steep walls, several meters high, carved in the vajont limestone formation. downslope, several minor scarps follow the strike of the bedding (from wnw-ese to ew). the scarp located around 1430 m a.s.l. limits a recent landslide scarp to the south. 161 the main scarp of the 1647 landslide is characterized by a series of steps forming three orders of vertical scarps reaching 20-30 m height, merging in a single irregular scarp along the western flank of the landslide crown. the historical landslide accumulation covers an area of about 160,000 m2, with a length of about 800 m and an estimated volume in the order of 1,5 mm3. its head lies at about 300 m from the lowermost scarp and is composed by huge blocks up to 840 m3 volume. the blocks have a prismatic to cubic shape and the farthest one has reached 750 m a.s.l. at places, the landslide deposit is covered by slope deposits due to erosional processes following the xvii century event. a relatively small and recent landslide deposit is in turn covering the scree slope around 1150 m a.s.l., witnessing ongoing slope instability processes (fig. 5). the 1674 landslide might have displayed a complex style of activity. the movement started as a rock block slide in the homoclinal slope evolving in a rock toppling at the front of the overthrust, where the bedding planes are sub-vertical (fig 4b, section 1). the movement continued along the slope as a rockfall. the same kinematics can be hypothesized also for landslides occurring in other sectors of the southern slope of m. salta in historical or prehistorical times (fig. 2b, section 2). the scarps of the minor westernmost landslides are characterized by a stepped morphology. the main movement appears to be by toppling, followed by slides and falls. the maximum volume of the blocks is of about 70 m3. these landslide events are supposed to be more recent since their body is not covered by any slope defig. 5 a) view of the 1674 m. salta landslide, from south: sa m. salta overthrust; sp le spesse overthrust; b) aerial view of the main geomorphological features of the landslide: the yellow circle indicates the toe of the western lobe, at present exploited by quarrying activity; the red circle shows the eastern lobe which affects the road connecting casso to the vajont valley; in the purple circle active slope deposits cover the central part of the 1674 landslide body (google earth); c) picture of the toe of the western lobe taken in ‘80s, before the opening of the quarry: the blocks are heterometric, angular, subangular, and monolithologic (vajont limestone fm.) one of the hazardous neighbours of the vajont landslide: the m. salta rock-block slide-rock fall posits. at the moment, the most hazardous sector appears to be the main scarp and its surroundings, along with the steep debris accumulation (fig. 5b and 6a). this area stretches from 1250 m a.s.l. to 1475 m a.s.l. it displays a steep and rugged morphology, developed in an intensely fractured rock mass. field surveys have revealed unstable rock blocks with volumes exceeding 1,000 m3. these blocks are separated by fractures up to 2 m wide and 10-15 m deep (fig. 6d). the shape of the scarp itself is due to the intersection of four joint sets: the main one is parallel to the bedding, and the secondary one is almost perpendicular to it. here, huge blocks (volume in the order of 300 m3) are isolated from the rest of the slope and have already undergone a backtilting movement along the bedding plane (fig. 6b). it is evident that those blocks represent a threat for the village of casso (fig. 6c). a monitoring system, based on extensometers placed across some large and open fractures located north-west of the 1674 crown between 1500 and 1600 m a.s.l., provided data about their opening and closing trends for a few years (ghirotti, 1995). unfortunately, the monitoring system is presently out of order. being this region active from the seismic point of view, the effect of seismic acceleration on the stability of the rocky scarps and of the debris has been addressed. the results of numerical modelling (marcato et al., 2007; tagliavini et al., 2009) show that the village of casso and the road could still be affected by rock falls detaching from the scarps and/or by remobilisation of debris deposits. the modelled scenarios could in principle be used for functional countermeasure works design and civil protection plans. for instance, as suggested by marcato et al. (2007), a realistic mitigation of the residual risk posed to the village of casso could foresee the continuation and progressive enlargement of the quarrying activity, in order to create a zone that could contain the debris possibly remobilised in case of co-seismic landslide events. 162 fig. 6 a) general view of the main scarp of m. salta landslide (red arrows mark the location of trenches and the extensometric net); b) a trench, more than 10 m wide and several tens of meters deep; c) outcrop of the vajont limestone fm. forming the main scarp at 1575 m a.s.l. in correspondence with the sliding surface; d) isolated rock wedges at critical stability condition, located at the eastern part of the main scarp. (figures 6a, c and d courtesy of cnr-irpi pd). ghirotti m. et al. conference field trip (october 10th, 2013). italian journal of engineering geology and environment book series no. 6, 635-646, sapienza università editrice, rome, italy. doi: 10.4408/ijege.2013-06.b-61 marcato, g., fujisawa, k., mantovani, m., pasuto, a., silvano, s., tagliavini, f., zabuski, l. (2007) evaluation of seismic effects on the landslide deposits of monte salta (eastern italian alps) using distinct element method, nat. hazards earth syst. sci., 7, 695-701. www.nat-hazards-earth-syst-sci.net/7/695/2007/ masè g., semenza m., semenza pa., semenza p., turrini m.c. (2004) le foto della frana del vajont. ed. k-flash. 1-47, 3 maps, cd-ro m with 300 photos, ferrara. http://www.k-flash.it/editoria_en.html massironi m, zampieri d, superchi l, bistacchi a, ravagnan r, bergamo a, ghirotti m, genevois r (2013) geological structures of the vajont landslide. italian journal of engineering geology and environment, book series no. 6, 573-582, sapienza università editrice, rome, italy. doi: 10.4408/ijege.2013-06.b-55 pasuto a. (2017) the vajont valley (eastern alps): a complex landscape deeply marked by landsliding. in m. soldatim. marchetti (eds.), landscapes and landforms of italy, world geomorphological landscapes, 135-145. doi: 10.1007/978-3-319-26194-2_11 riva m., besio m., masetti d., roccati f., sapigni m, semenza e. (1990) geologia delle valli vajont e gallina (dolomiti orientali). annali università di ferrara (sezione scienze geologiche e paleontologiche), 2 (4), 55-76. rossato s., ghirotti m., gabrieli f., livio f., bovo f., brezzi l., campedel p., cola s., ivy-ochs s., martin s., mozzi p., pasuto a., rigo m., simonini p., surian n., viganò a., vockenhuber c., wolter a. (2020) learning from the past to face the future: landslides in the piave valley (eastern alps, italy), alpine and mediterranean quaternary, 33, 2, 209-228. doi: 10.26382/amq.2020.14 semenza e., ghirotti m. (2000) history of 1963 vajont slide. the importance of the geological factors to recognise the ancient landslide. bull. eng. geol. env., 59, 87-97. doi: 10.1007/s100640000067 stead d., donati d., wolter a., sturzenegger m. (2019) application of remote sensing to the investigation of rock slopes: experience gained and lessons learned. isprs j. geo-inf., 8, 296. doi: 10.3390/ijgi8070296 stead d., wolter a. (2015) a critical review of rock slope failure mechanisms: the importance of structural geology. journal of structural geology, 74, 1-23. doi: 10.1016/j.jsg.2015.02.002 tagliavini f., reichenbach p., maragna d., guzzetti f., pasuto a. (2009) comparison of 2-d and 3-d computer models for the m. salta rock fall, vajont 4. conclusions the vajont valley is a tectonically and geomorphologically active area, where many large mass movements have occurred in the recent and distant past. the instability of the m. salta southern slope is certainly driven by the peculiar geologic and tectonic structure and in particular by the presence of a heavily fractured bedrock in the frontal band of the local thrust (benko & stead, 1998; stead & wolter, 2015). other factors have played a role in the progressive decay of the frictional strengths of the joint surfaces, like alpine climate and climate changes and related erosional processes, groundwater flow and karst dissolution, along with seismicity. glacial erosion and possible debuttressing have weakened the rock masses and changed stresses in the slope by unloading. the influence of past and current seismicity is not known, in terms of major co-seismic events, as only relatively small rock falls events have been recorded. nevertheless, earthquakes may have affected the strength of steep and fractured rock slopes. in conclusion, the combination of individual predisposing factors appears to be more relevant than specific triggers in driving slope processes affecting the m. salta southern slope. references benko b., stead d. (1998) the frank slide: a reexamination of the failure mechanism. canadian geotechnical journal, 35, 299-31. doi: 10.1139/t98-005 doglioni c. (1992) relationships between mesozoic extensional tectonics, stratigraphy and alpine inversion in the southern alps. eclogae geol. helv., 85(1), 105-126. dykes a.p., bromhead e.n., hosseyni s.m., ibsen m. (2013) a geomorphological reconnaissance of structurally-controlled landslides in the dolomites. in genevois r., prestininzi a. (eds) international conference on vajont 1963-2013: thoughts and analyses after 50 years since the catastrophic landslide. italian journal of engineering geology and environment, book series no.6. sapienza università editrice, rome, 129-136. doi:10.4408/ijege.2013-06.b-10 esposito c., sánchez cabanillas b., bozzano f. (2015) new data and interpretation of the huge clastic deposit of “la pineda hill” (vajont valley, northern italy). rend. online soc. geol. it., 35, 117-120. doi: 10.3301/rol.2015.78 evans s.g., hungr o. (1993) the assessment of rockfall hazard at the base of talus slopes. canadian geotechnical journal, 30, 620-636. doi: 10.1139/t93-054 ghirotti m. (1995) l’antica frana del m. borgà e primi risultati del monitoraggio dell’area di prà del salta (casso, pn). quad. geologia applicata, 1, 123130, pitagora editrice, bologna. ghirotti m., masetti d., massironi m., oddone e., sapigni m., zampieri d., wolter a. (2013) the 1963 vajont landslide (northeast alps, italy): post 163 one of the hazardous neighbours of the vajont landslide: the m. salta rock-block slide-rock fall valley, northern italy. geoinformatica, 13, 323337. doi: 10.1007/s10707-008-0071-2 wolter a., stead d., ward b.c., clague j.j., ghirotti m. (2016) engineering geomorphological characterisation of the vajont slide, italy, and a new interpretation of the chronology and evolution of the landslide. landslides, 13(5), 1067-1081. doi: 10.1007/s10346-015-0668-0 164 ghirotti m. et al. ms. received: july 27, 2020 revised: october 5, 2020 accepted: october 29, 2020 available online: november 30, 2020 amq30(1) 4 yurchenko 41-49 available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 30 (1), 2017, 41 49 vegetational evolution in the transcarpathian lowland (ukraine) during the middle pleniglacial (pollen study of the beregovo i site) tamara yurchenko taras shevchenko national university of kyiv, kyiv, ukraine corresponding author: t. yurchenko <aramant@ukr.net> abstract: a reconstruction of the vegetational evolution during the middle pleniglacial has been carried out on the basis of a pollen study of the loess-palaeosol deposits from the upper palaeolithic site beregovo i (transcarpathian lowland). the stratigraphy of the site is based on the quaternary stratigraphical framework of ukraine, the archaeological data and ams 14c-dating. at the end of the uday time of loess formation (early pleniglacial), forest-meadow ecosystems (with predominance of birch and pine in the forests) existed under the cold and wet climate of a stadial. three main stages of vegetation development (with several phases) have been identified within the vytachiv time (the middle pleniglacial). during the beginning of the first stage (the early vytachiv time, the formation of the lower cambisol), coniferous and broad-leaved forest grew under the rather warm climate of an interstadial. the second phase of this stage was characterized by a spread of a forest-steppe. the warm interstadial climate, indicated by the growth of broad-leaved trees, became less humid. during the second stage of the middle pleniglacial (the middle vytachiv time, represented by loess-like deposits), a boreal forest-meadow vegetation spread under the cool climate of a stadial. the aurignacian cultural horizon corresponds to the deposits of this stadial. three phases of vegetation development have been recognized within the third stage of the middle pleniglacial (the late vytachiv time). during the first phase (the beginning of the upper cambisol formation), there existed a forest-steppe with predominance of boreal trees. the climate was relatively cool and corresponded to a transition from a stadial to an interstadial. the second phase of this stage (the formation of the upper cambisol) was characterized by forest-meadow vegetation with a spread of broad-leaved trees. this phase corresponds to an interstadial warming. during the third phase (the transition from the cambisol formation to the incipient pedogenesis, ams dated to 27-26.6 ka uncal bp), an elm-hornbeam forest with admixture of spruce grew on fertile loamy soils, and pine-birch forest occupied the sandy terraces. the climate was still warm and humid. after the end of the middle pleniglacial (the beginning of the bug time), there occurred a spread of meadow vegetation. the decline of arboreal and broad-leaved vegetation indicated the much colder climate of a stadial. the reconstructed vegetation composition of the site demonstrates that the microclimate of the low terrace of the tysa river was milder than in the sites located on the high river terraces. broad-leaved trees were permanently present in the site vicinities: their pollen percentages increased during the periods of the formation of the interstadial soils and drastically decreased during the times of reduction of forest areas and formation of non-soil deposits. this enables the suggestion that refugia of broad-leaved trees could survive in the transcarpathian lowland during the stadials of the pleniglacial (at least before the last glacial maximum). keywords: pollen analysis, palaeovegetation, palaeoclimate, pleniglacial refugia of broad-leaved trees, beregovo i, ukraine. 1. introduction a study of palaeovegetation and palaeoclimate of the transcarpathian lowland is of a particular interest because this area, protected by the mountain ranges from the north and east, has less cold and continental climate than the plains of eastern europe. it might be suggested that it was suitable for the existence of refugia of broad-leaved trees during the pleniglacial. actually, this area is the easternmost part of the middle danube lowland but, on the other hand, its vegetation was formed in connection with the ukrainian carpathian geobotanical province (barabych, 1977). thus, a reconstruction of the palaeovegetation of the ukrainian transcarpathia provides the bridge between central and eastern europe. the whole area of the transcarpathian lowland tectonically corresponds to the transcarpathian depression, but its topography is quite diverse. accumulative alluvial plain of the north-west (the mukachevo lowland) is replaced to the south-east by erosion-accumulative hilly terrains (the solotvynska area). in the east, there is the vygorlat-hutyn ridge of neogene volcanic origin, and separate volcano hills are scattered in the southeast (vakhrushev et al., 2010). the transcarpathian depression is filled with neogene sediments − molasses and lagoonal-alluvial deposits. the quaternary deposits form the continuous cover on the lowland. they are mainly represented by alluvial deposits, which are frequently overlain by loess-palaeosol cover. the climate of the area is very mild as for eastern europe. at the beregovo town, the average july and january temperatures are +20°c and +3°c, respectively. the maximum july temperature is 40°c, the minimum january temperature is -28°c. the snow period (50 days in duration) is the shortest in the transcarpathian lowland. the annual precipitation is 650 mm (lipinski, 2003 ). the area lies within the forest-steppe vegetational belt of the pannonsky geobotanical province of heliophilous nemoral forests, meadows and meadow steppe (barabich, 1977). an important characteristic of these forests is the presence of an admixture of the southern species of oak (querus petraea and q. dalechampii). the forests also include carpinus betulus, 42 yurchenko t. acer campestre, ulmus glabra, rarely fagus sylvatica. fraxinus excelsior grows at lower altitudes, and swampy areas are occupied by alnus glutinosa. the understory is formed by corylus avellana, crataegus sp., euonymus verrucosa, e. europaeus, frangula alnus, viburnum opulus, sambucus nigra, and prunus spinosa. the ground cover is dominated by carex brizoides, galium odoratum, elymus repens, poa palustris, festuca pratensis, viola odorata, and convallaria majalis. the late pleistocene vegetational evolution in the transcarpathian lowland has been studied since the 70s of the xx century. the location of the studied sites is shown in fig. 1. the first pollen research has been carried out for the upper paleolithic site molochny kamin’, situated in a cave at the foothills of the carpathian mountains (gladilin & pashkevich, 1977; pashkevich, 1984). it has been shown that during the würm, the lower boundary of the mountain belt of alpine and subalpine meadows was located topographically at lower elevations than nowadays. sparse forest (pinus sylvestris, larix and juniperus) with ferns in the ground cover spread on the adjacent lowlands. a pollen study has been also carried out at the multilayered archeological site koroleve located on the highest terrace of the tysa river (pashkevich, 1984; adamenko & grodetskaya, 1987). four stages of vegetational evolution during the late pleistocene have been established: 1) pine and oak-pine forests (the transition from saalian to the last interglacial); 2) forests of pinus sylvestris, p. cembra, picea and larix with an admixture of quercus, fagus sylvatica, and alnus (beginning of the last interglacial, the kaydaky time); 3) quercus-carpinus and quercus-fagus forests with an admixture of pinus sylvestris and picea (last interglacial optimum, the pryluky time); 4) picea forest in the mountains, quercus and pinus sylvestris forests in the lowlands (the vytachiv time). during the last decade, a pollen study has been carried out for the gat’ site, located on the flat plain in the centre of the transcarpathian lowland (gerasimenko, 2006), and the paleolithic site sokyrnytsya i, situated on the high terrace of the tysa river, closer to the foothills of the carpathian mountains (gerasimenko, 2011). stages and phases of the vegetational evolution during the late pleistocene have been shown for the last interglacial (kaydaky unit), fig.1 location map of the studied sites. 43 vegetational evolution in the transcarpathian lowland ... beregovo i site early glacial (tyasmyn and pryluky units), and the pleniglacial (uday, vytachiv and bug units). the following stages of the last interglacial vegetation development have been recognized: pre-temperate (pine forest with an admixture of broad-leaved trees), earlytemperate (quercetum mixtum), the climatic optimum (broad-leaved forest with a high share of carpinus betulus and corylus), late-temperate (mixed forest: carpinus betulus, abies and picea), and post-temperate (piceapinus forest). during the two early glacial stadials, arcto -alpine and arcto-subalpine meadow-steppe and meadow-forest spread. during the first early glacial interstadial, mixed forest from boreal and broad-leaved trees existed, whereas during the second interstadial, boreal forest-meadow occupied the area. during the early pleniglacial (the uday time), arcto-alpine meadow and meadow-steppe expanded there. birch-pine forest with a small admixture of broad-leaved trees existed during the middle pleniglacial (the vytachiv time). the late pleniglacial (the bug time) was characterized by a spread of subperiglacial meadows and meadowsteppes. despite the importance of the information obtained in the previous study, further investigation is necessary in order to reconstruct in details the different vegetational patterns in the transcarpathian lowland and to define short-period phases in the vegetational development, particularly during the middle pleniglacial. such an important palaeobotanical issue is still unclear, as well as the existence of refugia of broad-leaved vegetation during the pleniglacial. 2. site location and stratigraphy the beregovo і site is located 1 km south of the beregovo town, on the 3rd terrace of the tysa river (1520 m above the floodplain level), in a place where the terrace is cut by the valley of the tysa tributary the werke river. the archeological study of the upper palaeolithic site beregovo i started in the 70-80s of the last century (smirnov, 1974; gladilin & soldatenko, 1975; tkachenko, 1989, 2003), as well as its pedostratigraphical study (adamenko et al. 1981; adamenko & grodetskaya, 1987). four upper pleistocene palaeosols were found and characterized within the loess cover of the terrace. the lowermost palaeosol was correlated with the last interglacial. the cultural layer corresponds to the loess unit separating the 1st and 2nd palaeosols, and it was related to the upper paleolithic (the late aurignacian). a recent research (usik, 2008, 2011) shows that the early aurignacian industry of the kremsdoufur type is represented there. the chronology of the sites has been based on the quaternary stratigraphical framework of ukraine (veklitch, 1993). later studies (matviishyna at al., 2010) proved that the uday loess unit is correlated with the early pleniglacial, the vytachiv unit with the middle pleniglacial, and the bug unit corresponds to the late pleniglacial. the vytachiv unit is subdivided into subunits which are correlated with the middle pleniglacial of western europe in the following way (gerasimenko, 2004): the lower vytachiv soil unit (vt1) corresponds to the interstadials moershoofd and hengelo, the middle vytachiv loess unit (vt2) is correlated with the huneborg stadial, and the upper vytachiv soil uit (vt3) corresponds to the denecamp interstadial. a short description of the upper part of the section, which was also studied palynologically (gerasimenko, 2006), is provided below. 0.00-0.20 m the former archaeological tip; 0.20-1.30 m the holocene (hl) luvisol; 1.30-1.85 m bug loess unit (bg) loess, pale yellowishbrow, clayey loam; 1.85-3.10 m vytachiv palaeosol unit (vt) with subunits: 1.85-2.00 m vt3c incipient soil, light-brown, clayey, compacted, with prismatic structure; 2.00-2.40 m vt3b upper cambisol, dark-brown, clayey, compacted, with prismatic structure and a lot of charcoal. the ams 14c date 27/26,6 ka uncal bp has been obtained on charcoal from the depth 2.08 2.18 m (usik at al., 2014); 2.40-2.60 m vt3b/vt2 transitional horizon of the lower cambisol, formed in the loess-like deposits, lightbrown, less clayey, slightly compacted, with small spots of ochre and charcoal. the aurignacian artifacts have been found here, mainly at the depth 2.402.50 m. 2.60-3.10 m vt1 lower cambisol, bright-brown, clayey, prismatic, strongly compacted, with clay cutans on ped surfaces, the downward transition is gradual; 3.10-3.50 m uday loess unit (ud) loess-like loam, gleyey, light greenish-grey, clayey loam, blocky, much less compacted than the overlying soil, with tiny nodules and punctuation of manganese hydroxides, particularly at the upper layer. 3. methods pollen was extracted from the sediments with the following procedure: a sample (100 g in weight) is boiled in a 10% solution of hcl, washed out with distilled water to neutral reaction, boiled in 25% solution of na4p2o7, and washed out again to neutral reaction. a second treatment in a 10% solution of hcl is undertaken in order to remove secondary carbonates, the sample washed out, and, finally, boiled in a 10% solution of koh with the consequent washing out to neutral reaction. after maceration, the sample is centrifuged in distilled water and heavy liquid (cdi2+ki). a heavy liquid of densities between 2.2 and 2.0 g/cm3 is used, and the obtained material is washed out several times (with the removal of water above the residue) until its volume fits a lab tube. then the residue is treated in a cold 45% solution of hf for 24 hours. such a treatment enables to obtain not less than 200 grains of pollen and terrestrial spores from a sample of mineral deposits. the preservation of palynomorphs in the studied samples was good. non-pollen palynomorphs (npp) are also represented, though they are not numerous in the studied samples. palynological atlases (bobrov et al., 1983; kuprianova & alyoshina, 1972, 1978; reille, 1998) have been used for pollen identification. the program psimpoll 4.27 (bennett, 2009) has been used to plot the pollen diagram. percentages of arboreal and non-arboreal pollen (ap and nap, respectively) and spores have been counted from a total sum including all of them. npp were represented mainly by pseudoschizaea, which is an indicator of local humidity in soils (scott, 1992). they are shown in a separate graph of the pollen diagram. 4. results eight pollen samples, labelled with the site prefix b, have been analyzed from the deposits of the beregovo i site (fig. 2). vegetation types are determined according to the results of the fundamental empirical studies of surface pollen samples in eastern europe (grichuk, 1989). b-1, corresponds to the upper part of uday loess unit (ud) and it records a forest-meadow vegetation (ap 44%, nap 8%, and spores 48%). the ap includes mainly pinus sylvestris (23%), betula (13%), and alnus (4%) though broad-leaved taxa are also represented (tilia cordata, 3%, and ulmus sp., 1%). the nap consists of forbs (5%) and poaceae (3%). the former includes asteroideae (2%) and single pollen grains of fabaceae, dipsacaceae and rumex. lycopodiaceae (38%) dominate among the spores. the percentage of bryales is 9%, and only single spores of filicales monolete occur. b-2, corresponds to the lower part of the lower vytachiv (vt1) soil. the pollen spectrum reveals a foreststeppe (ар 62.0%, nap 21.0%, and spores 17.0%). pinus sylvestris pollen prevails in the ap (36.6%), and pollen of picea abies is noticeable (8.5%). the pollen share of broad-leaved trees increases significantly as compared to b-1: quercus robur (4.2%), ulmus sp. (2.8%), carpinus betulus and fagus sylvatica (each being 1.4%). on the contrary, the pollen percentages of parvifoliate hardwood decrease, including betula (1.4%) and alnus (4.0%). pollen of sambucus nigra occurs in small numbers (1.4%). forbs prevail in the nap (17%), and they consist of asteraceae (5.6%), rosaceae (4.2%), including filipendula, and single pollen grains of scrophulariaceae, ranunculaceae, brassicaceae, and fabaceae. the rest of the nap consists of chenopodiaceae (2.8%) and few poaceae (1.4%). the pollen percentages of lycopodiaceae significantly decrease (14.4%). spores of sphagnum and filicales monolete (each being 1.4%) are present, and glomus-type spores, as well as pseudoschizaea spores also occur. b-3, in the upper part of the soil vt1, reveals a forest type of pollen spectrum (ар 46.9%, nap 29.2%, spores 23.8%). pollen percentages of pinus sylvestris and picea abies decrease (22.3% and 3.8%, respectively). on the contrary, pollen percentages of broadleaved trees significantly increase: quercus robur (4.6%), ulmus sp. and carpinus betulus (each being 1.4%). single pollen grains of caprifoliaceae and cornus mas occur. parvifoliate hardwood is represented by betula (5.4%) and alnus (3.1%). forbs prevail in the nap (18.5%). pollen of asteroideae is abundant (6.2%), cichorioideae and plantaginaceae are noticeable (3.83.1%), and single pollen grains of caryophyllaceae, ------------------------ >>> fig.2 pollen percentage diagram from the paleolithic site beregovo i. 44 yurchenko t. rosaceae including filipendula, scrophulariaceae, and fabaceae occur. pollen percentages of herbal xerophytes increase (chenopodiaceae, 9.2%). pollen of hydrophytes (typhaceae) also occur. the spores are represented by lycopodiaceae (16.2%), bryales (4.6%), sphagnum (2.3%), and filicales monolete (0.8%). the number of glomus-type spores and pseudoschizaea increases. b-4, in the loess unit vt2, has a forest-meadow type of pollen spectrum: ар 31.4%, nap 27.5%, spores 41.2%. in the ap, pinus sylvestris prevails (20.6%). betula sp. (7.8%) and picea abies (1.9%) are well represented. one pollen grain of tilia cordata has been found. forbs prevails in the nap (15.7%) and consists of asteraceae (7.8%), ranunculaceae (3.9%), polygonaceae (1.9%), fabaceae and caryophyllaceae (being 0.9% each). pollen percentage of poaceae is low (1.9%), as well as cyperaceae and liliaceae (being 0.9% each). pollen of herbal xerophytes include chenopodiaceae (6.8%) and ephedra (0.9%). the spores are represented by lycopodiaceae (29.4%) which prevail over those of bryales (11.7%). the numbers of glomustype spores and pseudoschizaea spores further increase, and abundant microcharcoal is present. three pollen samples correspond to the upper vytachiv soil (vt3b). b-5 corresponds to the lower part of the soil vt3b and has a forest-meadow type of pollen spectrum (ар 29.0%, nap 39.3%, spores 31.8%). pinus sylvestris (17.8%) prevails in the ap, and only a few pollen grains of picea abies (1.9%) are present. single pollen grains of broad-leaved taxa (quercus robur, tilia cordata and corylus avellana) occur. the parvifoliate hardwood is represented by betula (4.7%) and alnus (1.9%). forbs prevail in the nap (18.7%), but the percentage of poaceae is quite noticeable (7.5%). among forbs, pollen of asteraceae is abundant (7.5%), rosaceae (including filipendula) and ranunculaceae (including thalictrum) are noticeable (being 4.4% each), whereas polygonaceae is poorly represented (1.9%), and only single pollen grains of lamiaceae, fabaceae, linaceae, and hypericum have been found. the pollen percentages of xerophytes increase, including chenopodiaceae (10.3%) and artemisia (1.9%). the spores include mainly lycopodiaceae (29.4%) and few bryales (2.8%). the number of glomus-type spores and pseudoschizaea spores further increases, and microcharcoal is abundant. b-6, corresponds to the upper part of the soil vt3b, and it also has a forest-meadow type of pollen spectrum (ар 38.1%, nap 22.9%, spores 39.0). pinus sylvestris prevails in the ap (21.9%), and pollen of picea abies (3.8%), betula (2.9%) and alnus (1.0%) are present. the pollen percentages of broad-leaved taxa increase: tilia cordata (4.8%) and carpinus betulus (2.9%). one grain of viburnum opulus is present. forbs prevail in the nap (14.3%), whereas pollen percentage of poaceae is small (2.9%). the forbs include pollen of asteraceae (7.6%), scrophulariaceae and rosaceae (each being 1.9%) and single pollen grains of polygonaceae, apiaceae and cichorioideae. the pollen percentages of xerophytes decrease (chenopodiaceae 2.9%). pollen of hydrophytes (nymphaеаceae and sparganiaceae) appears. the pollen percentage of lycopodiaceae is large (24.8%), spores of filicales monolete and bryales are noticeable (being 6.7% each), and spores of sphagnum occur rarely (2.5%). the numbers of glomus-type spores and pseudoschizaea spores are rather large. b-7, corresponds to the transition to the soil vt3c and has a forest type of pollen spectrum (ар 52.4%, nap 26.2%, spores 21.4%). pinus sylvestris prevails in the ap (21.4%), and pollen of picea abies (3.6%) is present. broad-leaved taxa are represented by pollen of carpinus betulus (7.1%) and ulmus sp. (3.6%). the pollen percentages of parvifoliate hardwood are large (betula 13.1% and alnus 3.6%). the nap consists of forbs: asteraceae (4.8%), ranunculaceae and plantaginaceae (being 2.4% each), scrophulariaceae, linaceae and primulaceae (being 1.2% each). only few pollen grains of chenopodiaceae have been found. pollen of hydrophytes appear: potamogetonaceae (2.4%), butomaceae and nymphaеаceae (being 1.0% each). lycopodiaceae prevail among the spores (10.7%). spores of filicales monolete (4.8%), sphagnum (2.4%) osmunda, bryales and filicales trilete (being 1.2% each) have been also found. there are abundant microcharcoal particles, glomus-type spores and pseudoschizaea spores. the lower part of the bug loess unit (bg) has a meadow-steppe type of pollen spectrum (b-8): ар 25%, nap 21%, spores 54%. the ap includes mainly pinus sylvestris (17.0%). pollen of picea abies is present (3.0%) and single grains of carpinus betulus and ulmus sp. have been found. pollen percentages of other trees are also small: alnus (3%) and salix (1.0%). the pollen of forbs (11.5%) consist of asteraceae (4.0%), linaceae (2.0%), and single grains of brassicaceae, ranunculaceae, scrophulariaceae, fabaceae, lamiaceae, caryophyllaceae, dipsacaceae, and cichorioideae. thus, this sample is very diverse in its composition. herbal xerophytes are represented by chenopodiaceaе (6.0%). spores consist of lycopodiaceae (23.0%), filicales monolete (17.0%) and bryales (13.0%). one spore of sphagnum has been found. the numbers of microcharcoal, glomus-type spores and pseudoschizaea spores are still large. 5. palaeoenvironment the correspondence of pollen surface samples to the modern vegetational composition (grichuk, 1989) has been used here to reconstruct the phases of vegetational evolution during the vytachiv time (the middle pleniglacial), the end of the preceding uday time (the early pleniglacial) and the beginning of the following bug time (the late pleniglacial). before the beginning of the middle pleniglacial (the end of the uday time), forest-meadow ecosystems existed (b-1). club-mosses and green mosses formed the ground cover of birch-pine forests. occurrence of pollen grains of ulmus sp. and tilia cordata indicate a possible existence of refugia of broad-leaved vegetation in the valleys. alder groves grew in the wet localities. meadows consisted of plants from asteraceae, fabaceae, dipsacaceae, and poaceae fami 45 vegetational evolution in the transcarpathian lowland ... beregovo i site lies. this type of vegetation is typical for a cool and humid boreal climate, that corresponds to the end of a stadial. during the first stage of the middle pleniglacial (the early vytachiv time, vt1), two phases of vegetation development have been recognized. during the first phase, coniferous and broad-leaved forests occupied the area under investigation. elm-oak forests with an admixture of hornbeam, beech and spruce grew on the fertile loamy soils, pine groves occupied sand terraces and alder occurred near the river courses. mesophytic herbs of the asteraceae, rosaceae, brassicaceae and fabaceae families grew in the ground layer of broadleaved forests. the spread of broad-leaved trees indicates an interstadial warming. the replacement of clubmosses and mosses by herbs in the ground cover of forests might be connected with an increase in evaporation under a warmer climate, and, thus, with a decrease in ground moisture. the second phase of vegetation evolution was characterized by a spread of a forest-steppe, as it is evidenced by the decrease in the ap and the spore percentages in b-3. broad-leaved taxa included oak, hornbeam and lime-tree. the portion of wet-loving beech and spruce in the forest composition decreased as compared with the preceding phase. this, as well as the spread of herbal associations, indicates that the climate became less humid than during the preceding phase. though it was rather warm, as suggested by the pollen percentages of broad-leaved taxa and the appearance of cornus mas pollen. open areas were occupied by meadow-steppe: mainly plants belonging to asteroideae, cichorioideae and plantaginaceae, less frequently caryophyllaceae, rosaceae (including filipendula) scrophulariaceae, and fabaceae. the appearance of chenopodiaceae pollen indicates the replacement of meadows by meadow-steppe. nevertheless, the abundance of pseudoschizaea spores and pollen of typha latifolia indicate a local increase in the ground moisture, connected with a higher water level in the river (scott, 1992). the second stage of the middle pleniglacial (the middle vytachiv time, vt2) was characterized by the spread of a forest-meadow vegetation (b-4). a reduction in forest areas occurred. forests consisted mainly of birch and pine, and the portion of broadleaved trees decreased as compared to the previous stage. this indicates a significant cooling, that is typical for a stadial. however, few refugia of broad-leaved trees still existed, and lime-tree evidently continued to produce pollen. the low pollen percentages of pine indicate that its portion in the arboreal vegetation was very small. mesophytic plants from the asteraceae, ranunculaceae, polygonaceae, fabaceae and caryophyllaceae families prevailed in the open ecosystems, whereas steppe components of herbal coenoses (chenopodiaceae and sparse ephedra) were less frequent than during the previous phase. the decrease in warmth and evaporation was a possible reason for the spread of meadows to the expenses of meadow-steppe. the composition of forbs became more diverse, and club-mosess, mosses and microspores (indicators of soil humidity) were abundant. it was a time when the carriers of the aurignacian industry arrived at the site. the third stage of the middle pleniglacial (the late vytachiv time, vt3) was characterized by three phases of vegetation development. during the first phase, there existed a forest-steppe vegetation (b-5). the low pollen percentages of pine and spruce indicate that they did not grow near the site (their pollen was probably wind-transported from the carpathian mountains). birch forests with club-mosses and green mosses in the ground cover prevailed, and alder grew in the lowest localities. oak, lime-tree and hazel occurred rarely. the portion of broad-leaved trees slightly increased as compared to the vt2 time, but climate still was cool and corresponded to a transition from a stadial to an interstadial. herbal associations were of a meadow-steppe type. forbs prevailed, and their composition became more diverse than before, including plants of the asteraceae, rosaceae, ranunculaceae (including thalictrum), polygonaceae, lamiaceae, fabaceae, linaceae families and hypericum. the steppe elements included poaceae, chenopodiaceae and artemisia. the second phase of vegetation evolution (b-6) was characterized by a spread of the forest-meadow vegetation. forest areas became larger, and the participation of broad-leaved trees, represented by limetree and hornbeam, increased, as well as the spread of ferns in the ground cover. spruce became more abundant, and viburnum opulus occurred in the undergrowth. this phase corresponds to an interstadial warming. meadows included mesophytic herbs from asteroideae, scrophulariaceae, polygonaceae, apiaceae and cichorioideae. the portion of grasses and xerophytes significantly decreased. wet localities were occupied by alder, club-mosses and green mosses. the increase in pollen of hydrophytes (nymphaеаceae and sparganiaceae) and pseudoschizaea spores indicates a local raise in the water level. the third phase of vegetation evolution (b-7) was characterized by a spread of elm-hornbeam forest with admixture of spruce on fertile loamy soils and pinebirch forest on sandy terraces. a spread of wet-loving hornbeam and spruce was maximum as compared with the previous phases. this indicates a further increase in humidity during the interstadial, ams dated to 27/26.6 ka uncal bp (usik at al., 2014). the ground cover of broad-leaved forests consisted of ferns and mesophytic herbs from asteraceae, ranunculaceae, plantaginaceae, scrophulariaceae, linaceae, and primulaceae families. pine-birch and alder groves had club mosses and green mosses in the ground cover. the presence of hydrophytes (potamogetonaceae, butomaceae, nymphaеаceae and osmunda), as well as pseudoschizaea spores indicate a high-water level in the river. after the end of the middle pleniglacial (the beginning of the bug time), there occurred a spread of meadow vegetation (b-8). the arboreal vegetation 46 yurchenko t. grew along the river course and consisted of spruce, alder and willow. the low pollen percentages of pine indicate a very limited growth of this tree in the studied area. the presence of few pollen grains of elm and hornbeam shows that their refugia still existed in the transcarpathian lowland. club-mosses, green mosses and ferns formed the ground cover under the trees, but they could also grow in the meadows. the maximum of pseudoschizaea spores shows an excess of water in the ground. meadow plants were diverse (asteroideae, linaceae, brassicaceae, ranunculaceae, scrophulariaceae, fabaceae, lamiaceae, caryophyllaceae, dipsacaceae and cichorioideae). the strong reduction in forested areas and the significant decrease in broadleaved taxa indicate that the climate became much colder than before. it was the beginning of a stadial. 6. discussion in general, the fulfilled reconstructions are correlated with those obtained from the other sites of the transcarpathia but the local characteristics of the vegetation on different forms of relief are rather distinct. during the uday time (the early pleniglacial) on the high river terraces, grasses and sedges dominated, and few alder, willow and pine occurred in gullies. at the end of this time, trees disappeared completely (gladilin & pashkevich, 1977; pashkevich, 1984). a spread of cryophytes (shrub birch and arcto-boreal forms of clubmosses) during this time (gerasimenko, 2006) is an indicator of a periglacial climate. thus, refugia of arboreal and broad-leaved trees existed only on the slopes of the low river terraces as in the case of the beregovo i site. in western ukraine, the complete successions of the vytachiv deposits (the middle pleniglacial) are represented only in the middle dniester valley (bolikhovskaya, pashkevich, 1982; bolikhovskaya, 1995) and at the beregovo i site. the first stage of the middle pleniglacial (the vt1 time) is correlated by 14c dating with the two first interstadials of the middle valday (gerasimenko, 2004). during the warmest interstadial (39-37 kyr bp), the forest-steppe (with admixture of quercus robur, carpinus betulus, tilia cordata and ulmus sp. in pine forest) was distributed on the low terraces of the dniester river. on the low terraces of the tysa river, the forests included more broad-leaved taxa, and mesophytic trees such as fagus sylvatica and picea abies, as well as the warm-loving cornus mas. during the second stage of the middle pleniglacial (the vt2 time, 14c 36-30 kyr bp) which is correlated with the second middle valday stadial (gerasimenko, 2004), the middle dniester valley was occupied by periglacial vegetation. shrub associations of betula fruticosa, b. nana and alnaster fruticosus on sphagnum peat bogs, on one hand, and xeric herbs, on the other hand, formed a mosaic vegetational pattern (bolikhovskaya, 1995). during this time on the lower terraces of the tysa river, forested areas became much smaller than during the preceding interstadial, but tilia cordata persisted, and herbal cover consisted mainly of mesophytes. there are no indications of the presence of cryophytes. during the third stage of the middle pleniglacial (the vt3 time, 14c 30-27 kyr bp), which is correlated with the third middle valdai interstadial (14c 29-25 kyr bp), carpinus betulus was a main component of the forests of the middle dniester valley. fagus sylvatica, quercus robur, tilia platyphyllos, acer and fraxinus also lived there (bolikhovskaya, pashkevich, 1984; bolikhovskaya, 1995). on the lower terraces of the tysa river, during the climatic optimum of the late vytachiv time, carpinus betulus also prevailed among broadleaved trees, but the portion of meso-hygrophytic betula pubescens was significant. the latter is evidently connected with a rise of water level in the river, indicated by the spread of hydrophytes and abundance of pseudoschizaea in the soils. thus, during the correlative stages of the middle pleniglacial, the vegetation of the low river terraces in transcarpathia was formed under more humid and warmer climate than in the middle dniester valley, although during the third phase, the lower river terraces of transcarpathia were over-wetted as compared with the dniester terraces. the vegetation of the vytachiv time around the other transcarpathian site, located in the low landform, also included abundant hygrophytes (gerasimenko, 2011). alnus glutinosa and cyperaceae were abundant, though oak was common in the forest composition. on the contrary, on the high terraces of the tysa river, oak formed a small admixture in light pine forests with herbal ground cover. the portion of wet-loving ferns and club-mosses was lower than at the beregovo i site (pashkevich, 1984; gerasimenko, 2006). thus, during the vytachiv time, the vegetation of the low terraces was richer in mesophytic and hygrophytic components than in the higher levels of the relief. during the late pleniglacial (the bug time), alpine and subalpine meadows including cryophytic plants (alnaster fruticosus, betula nana, botrychium boreale, and lycopodium selago), occupied the foothills of the carpathian mountains, whereas in the gullies that dissected the foothills, pine and larch were growing (pashkevich, 1986). more xeric periglacial meadowsteppe vegetation spread on the high river terraces (gerasimenko, 2006), although at the beginning of the bug time cryophytes were absent in these meadows, which indicates the existence of a less harsh boreal climate. meadow vegetation also dominated on low terraces of the tysa river. here, arboreal vegetation included boreal trees and a few elms and hornbeams. thus, the distribution of cold-tolerant and warmthdemanding plants in transcarpathia was controlled by the elevation. at the beginning of the bug time, broadleaved trees did not grow in the middle dniester valley. as opposite, arcto-alpine plants formed a significant part of the tundra-steppe and tundra-forest-steppe vegetation (bolikhovskaya & pashkevich, 1982; gerasimenko at al., 2012). thus, the climate of the transcarpathian river valleys was essentially milder than in the middle dniester valley. pollen and plant macrofossil evidence indicates that broad-leaved trees grew in the eastern part of the middle danube plain (hungary) even during the lgm (willis at al., 2000). judging from these data, refugia of broad-leaved trees were present indeed in the transcarpathian lowland during the late pleniglacial, and they were located on the lower ter 47 vegetational evolution in the transcarpathian lowland ... beregovo i site races of the tysa river. judging from the position of the beregovo i site near the palaeogully, which was dissecting the terrace, it is suggested that such palaeogullies might be the places for refugia of broad-leaved trees during stadial periods. references adamenko o.m., pospelova g.a., gladilin v.n., gorodeska g.d., gnibidenko z.n., adamenko r.s., aphanasyev g.m. pashkevych g.a., soldatenko l.v., stelmah o.r. (1981) opornyye magnitobiostratigraficheskiye razrezy antropogenovykh otlozheniy zakarpat'ya. [the key magneto-biostratigraphical sites of the quaternary deposits of the transcarpathia]. proceedings of the academy of sciences of the ussr. seriya geologicheskaya, 11, 55-73. (in russian) adamenko o.m., grodetskaya g.d. (1987) antropogen zakarpattia [the quaternary of the transcarpathia]. shtiintsa, kishinev, moldova, p.p. 147. (in russian) barabich a.i. (1977) heobotanichne rayonuvannya ukrayins ḱoyi rsr. [geobotanical zoning of ukrainian ssr]. naukova dumka, kyiv, p.p. 303. (in ukrainian) bennett k.d. (2009) documentation for psimpoll 4.27 and pscomb 1.03: c programs for plotting pollen diagrams and analysing pollen data. the 14chrono centre, archaeology and palaeoecology. queen’s university of belfast, department of archaeology and palaeoecology. available online from: http://www.chrono.qub.ac.uk/psimpoll/ psimpoll.htm. bobrov a.e., kuprianova l.i., litvintseva m.v., tarasevych v.f. (1983) spory paporotnykoobraznykh y pylʹtsa holosemennykh y odnodolʹnykh rastenyy flory evropeyskoy chasty sssr. [sporae pteridophytorum et pollen gimnopermarum monocotyledonearumque florae partis europaeae urss]. science, leningrad, p.p.190. (in russian) bolikhovskaya n.s., pashkevich g.a. (1982) dinamika rastitel'nosti v okrestnostyakh stoyanki molodova i v pozdnem pleystotsene [vegetational dynamic in the vicinities of the molodova i site during the late pleistocene]. molodova i. unikal'noye must'yerskoye poseleniye na srednem dnestre. ivanova i.k. (ed.). nauka, moskva, 120-145. (in russian) bolikhivskaya n.s. (1995) evolyutsiya lessovopochvennoy formatsii severnoy yevrazii. [the evolution of loess-soil formation of northern eurasia]. moscow state university, moscow, p.p. 270. (in russian) gerasimenko n.p. (2004) short-duration climatic cycles recorded in the middle and upper pleniglacial sequences in ukraine. zmyany klimatu zapisіany w sekwencjach lessovych. vroclaw-strzelyn, 3739. gerasimenko n.p. (2006) dynamika paleoekologicheskikh obstanovok na stoyanke sokyrnitsya i. [the dynamics of palaeoenvironments at the sokirnitsa i site]. yevropeyskiy sredniy paleolit. shlyakh, kyiv, 6-27. (in russian) gerasimenko n.p. (2011) the gat’ section as a new reference quaternary site of the transcarpathia. the quaternary studies in ukraine, kyiv, 27-38. gerasimenko n.p., yurchenko t.i., kulakovska l., usyk v.i., haesearts p., ridush b.t. (2012) do zmin roslynnosti serednogo prydnistrovya u piznomu pleniglyatsiali (za palinomaterialamy stoyanky doroshivtsi iii. [on vegetation changes in the middle dniester area during the late pleniglacial (based on pollen results from the doroshivtsi iii site)]. evolyutsiya ta antropogenizatsiya landshaftiv peredgirs'kikh i girs'kikh teritoriy. materialy mizhnarodnoi naukovoi konferentsii. chernivtsi, 13-14. (in ukrainian). gladilin v.n., soldatenko l.v. (1975) itogi pyatiletnih issledovaniy zakarpatskoy paleoliticheskoy ekspeditsii [the results of the five-year work of the transcarpathian paleolithic expedition]. noveyshie otkrytia sovetskih arheologov. naukova dumka, kyiv, 31-34. (in russian). gladilin v.n., pashkevich g.a. (1977) paleogeografia srednego i pozdnego vyurma zakarpat'ya po dannym issledovaniy v peshchere molochny kamen'. [palaeogeography of the middle and late wurm in the transcarpathia based on the research of the molochny kamin’ cave]. paleoekologiya drevnego cheloveka. nauka, moscow, 106-112. (in russian). grichuk v.p. (1989) ystoryya flory y rastytelʹnosty russkoy ravnyny v pleystotsene. [the history of flora and vegetation of the russian plain during the pleistocene]. nauka, moscow, p.p. 183. (in russian) kuprianova l.i., alyoshina l.a. (1972) pylʹtsa y spory rastenyy flory evropeyskoy chasty sssr. i. [pollen and spores of plants from flora of european part og the ussr. i.]. science, leningrad, p.p. 170. (in russian) kuprianova l.i., alyoshina l.a. (1978) pylʹtsa dvudolʹnykh rastenyy flory evropeyskoy chasty sssr. [pollen digotyledonearum florae partis europaeae urss]. science, leningrad, p.p.179. (in russian) lipinski v.m., dyachuk v.a., babichenko v.n. (eds.) (2003) klimat ukrayiny [climate of ukraine], izd. rajewski, kyiv, p.p. 343. (in ukrainian). matviishyna j.m., gerasimenko n.p., perederiy v.i., bragіn a.m., іvchenko a.s. (2010) prostorovochasova korelyatsiya paleogeografichnykh umov chetvertynnogo periodu na terytorii ukrayiny [spatialtemporal correlation of the quaternary palaeoenvironments in ukraine]. naukova dumka, kyiv, p.p. 191. (in ukrainian). pashkevich g.a. (1984) pryrodne seredovyshche v epokhu paleolitu – mezolitu na teritorii ukrainy. [the environments of the paleolithic and mesolithic epochs in ukraine]. arkheologiya, 47, 11-12. (in ukrainian). reille m. (1998) pollen et spores d'europe et d'afrique du nord, supplément 2. éditions du laboratoire de botanique historique et palynologie, marseille, p.p. 530, f.f. 1600. scott l. (1992) environmental implications and origin of microscopic pseudoschizaea thiergart and 48 yurchenko t. frantz ex r. potonie emend. in sediments. journal of biogeography, 349-354. smirnov s.v. (1974) pizn'opaleolitychna stoyanka berehove i na zakarpatti. [the upper paleolitic site beregovo i in the transcarpathia]. arkheologiya, 13, 26-30. (in ukrainian) tkachenko v.i. (1989) the berehove group of upper palaeolithic sites in transcarpathia. antropologie, 213-222. tkachenko v.i. (2003) pizniy paleolit ukraini (pamyatki orinyaks'koi tradytsii). [the upper paleolithic of ukraine (the sites of the aurignacian tradition)]. kyiv, p.p. 199. (in ukrainian) usik v.i. (2008) verkhniy paleolit zakarpattya: khronologiya i kul'turnaya prinadlezhnost' orin'yaka berehove i. [the upper paleolithic of the transcarpathia: chronology and cultural attribution of the aurignacian at the beregovo і]. materialy i doslidzhennya z arkheologii prykarpattya i volyni, 12, 49-67. (in ukrainian) usik v.i., monihal k., gerasimenko n.p. (2011) verkhniy paleolit zakarpattya. doslidzhennya paleolitychnoyi stoyanky berehove i u 2006 2007 years. [the upper paleolithic of transcarpathia. research paleolithic sites beregovo i in 20062007]. archaeological researches in ukraine (2006-2007), kyiv, 344-350. (in ukrainian) usik v., nigst p., haesaerts p., gerasimenko n., koulakovska l., racz b., kromer b., hublin j.j. (2014) new date of the early upper paleolithic of western ukraine: chronology, environment and human behavior at the aurignacian site beregovo i. xvii congress mondial de l’uispp, burgos, 227-228. vakhrushev b.a., kovalchuk i.p., komlev o.o., kravchuk y.s., palienko e.t., rud'ko g.i., stetsyuk v.v. (2010) relʹyef ukrayiny [relief of ukraine]. publishing house "slovo", kyiv, p.p. 688. (in ukrainian) veklitch m.f. (1993) stratigraficheskaya skhema pleystotsenovykh oblozheniy ukrainy [stratigraphical framework of quaternary deposits of ukraine]. goskom geologii ukrainy, kiev, 1 40. (in russian) willis k., rudner e., sumegi p. (2000) the full-glacial forests of central and southeastern europe. quaternary research, 203-213. 49 vegetational evolution in the transcarpathian lowland ... beregovo i site ms. received: november 2, 2016 final text received: march 18, 2017 amq70 luberti et al vergari proofcopy 3b doi available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 31 (2), 2018, 119 132 anthropogenic modifications to the drainage network of rome (italy): the case study of the aqua mariana gian marco luberti 1, francesca vergari 2, roberta marini 2, alessia pica 2, maurizio del monte 2 1 istituto superiore per la protezione e la ricerca ambientale, italy 2 dipartimento di scienze della terra, sapienza università di roma, italy corresponding author: f. vergari <francesca.vergari@uniroma1.it> abstract: rome is characterized by millennia of urbanization. long lasting geomorphological investigations have allowed the geomorphological description of the city centre and the valorisation of its geomorphological heritage. in this paper the spatial change of the hydrographic network in historical times is illustrated, with some examples showing how deep has been, and still it is, the link between the historical-cultural development and the natural geomorphological and hydrological characteristics of the roman territory. in particular, the most relevant human interventions on the drainage network, in the southern area of the city centre, have been investigated. before the land-use modifications of roman-age, this area was drained by the most important left tributary of the tiber river within the city walls, the nodicus river, more recently known as aqua mariana. this stream has undergone many anthropogenic modifications and diversions during the centuries, and its original path is known only downstream of the san giovanni basilica. according to geomorphological, archaeological and geological evidences, it is possible to hypothesize that the dimension of the pre-urbanization drainage basin, as known and reconstructed in the available literature, should have been until now underestimated. keywords: rome (italy), urban geomorphology, urban landscape, tiber river, aqua mariana, nodicus river 1. introduction the history and cultural heritage of rome are well known all over the world. not so its geo-environmental heritage, which is also very important and has guided the initial settlement choices and the subsequent growth of one of the most important cities for the development of civilization. although many geomorphological features have been hidden or completely eliminated during millennial urbanization processes, the landscape of rome still preserves the main landforms of the original physical landscape. after a general description of the geo-environmental characteristics of the area corresponding to the historical centre of the urbs and the lower tiber valley, to the neighbouring coastal belt, the historical spatial changes of the hydrographic network are illustrated in more detail. by some examples we demonstrate how deep has been, and still it is, the link between the historical-cultural development and the natural geomorphological and hydrological characteristics of the roman territory. in this paper, we focus on the most relevant human interventions on the drainage network within the city walls. in ancient times, the southern area of the urbs was drained by the nodicus river, according to lanciani (1881), that was the most important left tributary of the tiber river (tr) in the city. geomorphological, archaeological and geological evidences show that nodicus was a very significant tributary of the tr in terms of fluvial energy, as attested by the wide valley hosting the circus maximus. despite the extensive urban modifications during the roman times, including land reclamation and backfilling, the medieval aqua mariana artificial stream was carried out to flow within the nodicus valley, at least downstream of the san giovanni basilica. as a consequence, we hypothesize that, until now, the nodicus river’s dimensions, in terms of drainage-basin area and hydrographic-network evolution have been underestimated. 2. study area rome is located in the tyrrhenian side of central italy, w of the lazio-abruzzo central apennine (fig. 1). the physical landscape, mainly hilly, is characterized by the presence of two volcanic reliefs, i.e. the sabatini mountains and the alban hills (latium volcano). on the right and on the left sides of the tr, which links the city to the coast, two clearly different areas from a geomorphological point of view are present. the territory on the left side of the tr (se) hosts a large volcanic plateau, which formed during the middle-upper pleistocene from https://doi.org/10.26382/amq.2018.08 120 luberti g.m. et al. several eruptive phases belonging to both previous volcanic districts. over the same time, this plateau started to be deeply carved by the tiber fluvial system, many times, in occasion of sea-level low standing (bellotti et al., 2007). thus, in the upper pleistocene a long phase of in-depth fluvial incision carved the same valleys as canyons or gorges (pica et al., 2016; 2017, and references therein). the tr tributaries created a series of very deep valleys, with steep slopes. the most important valleys, including those drained by the main water course, today appear flat-bottomed, due to post-glacial fluvial depositional processes, which originated the flat surface (fig. 2) corresponding to the current city centre (campus martius, campo de' fiori). the fluvial incision led to the development of numerous elongated ridges in the interfluvium areas, flat at the summit, which still dominate the urban landscape of this eastern sector; this is the typical shape of some of the famous roman-age "seven hills", such as the quirinale. other hills, such as the aventino and the palatino, appear instead as small isolated reliefs, with steep slopes, sloping from the flat top towards the underlying alluvial plain of the tr (fig. 3). in the western side of the tr, the alluvial plain ends at the foot of the ridge that connects, from n to s, the ridges of monte mario and gianicolo (figs. 2 and 3). the summit of this ridge reaches 139 m a.s.l., while the hills on the east side do not exceed 50 ÷ 60 m a.s.l. the basal outcropping lithologies of the study area (fig. 2) consist of marine clays and marls (pliocene and early pleistocene), up to 800 m thick. the marine sedimentary succession, accumulated in the depressions formed during the extensional tectonics of the tyrrhenian margin of the apennines, is overlain by epicontinental sediments deposited during the subsequent, progressive, crustal uplift. starting from about 0.8 ma the sabatini mountains and alban hills volcanic complexes produced different rocks; in fact stratified lavas and pyroclastic flow, surge and fall deposits, are widespread throughout rome (fig. 2). these volcanic products alternated with sedimentary deposits and both were submitted to a very complex interplay of erosional and depositional processes during sea level fluctuations, tectonic displacements and volcanic activity (luberti et al., 2017 and references therein). the emplacement of volcanic products changed the topography and hydrography of the area (heiken et al. 2005 and references therein): the ancient streams and the tiber trunk (known as "paleotevere") progressively moved towards the monte mario-gianicolo ridge. fig. 1 the present-day urban area of rome. it extends from the volcanic flanks of the sabatini mountains and the alban hills, located nw and se respectively, to the tiber river mouth, sw of the city centre. the urban centre, which is represented in figure 2, is within the square blue frame. upper-left corner coordinates: 42° 13’ 29’’ n, 12° 00’ 58’’ e (mosaic from nasa satellite images). 121 anthropogenic modifications to the aqua mariana stream (rome) fig. 2 the main outcropping lithologies of the city centre (modified after del monte et al., 2016, whose study area is marked by the blue line). the main valleys of tiber river and its tributaries are recognizable, as well as the main ridges. a: trace of the geomorphologic cross section in fig. 3. upper-left corner coordinates: 41° 57’ 56’’ n, 12° 25’ 13’’ e. fig. 3 a schematic cross section along the city centre showing the main geomorphological features of the area (modified after del monte et al., 2013). the trace of the cross section is marked in fig. 2. the last change of both the rome urban area and the facing coastline is connected to the development of the tr hydrographic network during the major sea-level lowering, in correspondence of the last glacial maximum (lgm). the significant drop in sea level induced strong erosional processes; in the city centre, the tr and its tributaries cut into the plio-pleistocene succession to an elevation of 50 m below the present sea level. during the following post-glacial sea level rise (17-5 ka; bellotti et al., 2007), alluvial sediments, up to 60 m thick, were deposited (bozzano et al., 2000; ascani et al., 2008) (fig. 3). during the last three thousand years, human activities contributed to remodelling the topographic surface, profoundly modifying the hydrographic network and depositing almost everywhere a large quantity of anthropogenic heterogeneous and heterometric materials, deriving from various types of waste, fragments of bricks, tiles, amphorae, etc., all incorporated into a finer matrix, made up of volcanic, alluvial and colluvial materials. this "anthropogenic layer" continuously covers the entire roman area, with a thickness that can vary from a few centimetres to several metres or even tens of metres in the valley bottoms (del monte et al., 2016). 3. methodology: multi-disciplinary and multi-temporal geomorphological investigations the investigations, aiming at reconstructing the natural landscape of the city centre together with the main anthropogenic topographic and hydrographic modifications, were performed over several years, during which a detailed geomorphological survey and multitemporal analysis of aerial photographs and topographic maps were carried out. to obtain information on morphological changes over longer periods, the geomorphological survey was supported by the analysis of aerial photographs (stereoscopic and non-stereoscopic) taken in the last 80 years. the results of the aerial photo analysis were matched with the geomorphological study of the ‘piano topografico di roma e suburbio’, a topographic map surveyed in 1907 for the urbanisation plan of rome, and updated in 1924, at 1:5000 scale with a contour interval of 1 m (igm, 1924). furthermore, in order to detect ancient modifications to the topographic surface, the analysis of historical cartography was conducted using both the available previous maps, surveyed with trigonometric methods, and other maps without contours and having planimetric precision. among them, we included the maps by moltke (1852) and presidenza del censo (1839); moreover, the urbs map by nolli (1748a), even though it only covers the area inside the imperial city walls. in addition, more ancient ‘bird’s eye’ maps were useful to detect some landforms (e.g. dupérac, 1577; falda, 1676; frutaz, 1962). moreover, important information on missing natural landforms was obtained from paintings and further iconographic documents. a number of old papers were also consulted, such as historical books, archaeological papers and the archaeological map of rome of lanciani (1893-1901). in order to collect relevant information to the study of the geomorphologic characteristics before the man-made modifications, many recent studies on the ancient topography of rome (e.g. quilici, 1990) were examined, as well as the preliminary archaeological results from the works for the construction of the metropolitan railway line c (san giovanni underground station explanatory panels, edited and organized by mibact and roma capitale). locally, useful information about the thickness of the anthropogenic deposits, which mask natural deposits and landforms, was also collected from the drilling databases (ventriglia, 1971, 2002) and some geothematic maps, such as the ‘anthropogenic deposit thickness’ maps (corazza & marra, 1995; ventriglia, 1971). the spatial distribution of bedrock was traced according to the lithostratigraphic map of ventriglia (2002) and also taking into account both other geological maps (funiciello & giordano, 2008; marra & rosa, 1995) and a large body of literature. 4. the fluvial landscape of rome over historical time and its anthropogenic modifications in the historical centre, the valleys crossed by the tr and its main tributaries today present a flat-bottomed configuration, due to both the depositional processes occurred since the end of last glacial and more recently the urbanisation. the main river plain (fig. 4) extends, to e, at the foot of the slopes of the pincio, quirinale, capitolino and aventino hills, and to w at the foot of the gianicolo-monte mario ridge. the main channels (including the tr) still show the effects of lateral and/or linear erosion, despite the erosion mitigation works operated. on the west bank of the tr, the landforms shaped by the action of the surface running water are still very widespread throughout the area. the monte mario ridge is deeply furrowed by the valle aurelia, which slope progressively declines towards the tr, describing an anti-clockwise pattern near the vatican city (figs. 1 and 2). a good number of the fluvial channels, in particular the smaller ones, are still in the linear incision phase. a series of small, narrow and deep valleys affects the slopes of the monte mario-gianicolo ridge, on the top of which few outcrops of volcanic products are observed. even small through-shaped valleys are quite common; their genesis is due to the combined erosional action of surface runoff and gravitational processes. at the time of the foundation of rome, trastevere (trans tiberim), a flat area located at the foot of the gianicolo ridge, was a marsh controlled by the etruscans. today's district lies entirely on the alluvial plain of the tr (figs. 3 and 4). on the left bank of the tr, the fluvial plain is overlooked by a relief summit slightly inclined, considerably dissected by the erosive action of the tr system and its tributaries. today the main fluvial valleys, partially filled by the post-glacial alluvial deposits, show a similar shape, though obviously varying in size. for example, 122 luberti g.m. et al. the murcia valley, a small depression with a flat bottom (fig. 2), perfectly straight for a length of two kilometres and about two hundred metres wide, represented an ideal natural landform for hosting a large stadium like the circus maximus (del monte et al., 2013; del monte, 2017). the urbanization of this fluvial landscape started a long time ago. it is well known that the ancients began to build rome on the legendary seven hills. the first villages were built on the hills closest to the tiber river and isle (coarelli, 2001); these hills, some tens of metres higher than the tiber alluvial plain, being characterized by steep slopes but rather flat summits, were easy to defend from enemy attacks and, at the same time, suitable to host stable settlements, being far from the marshes at the bottom of the valleys. moreover, in this side of the tr, the erosional processes, already described in the previous paragraph, were and still are, of lower intensity and frequency (del monte et al., 2016). thus, the seven hills and the other surrounding hills originated from the fluvial processes operated by the tiber drainage system, which carved them during the upper pleistocene, and then were partially remodelled by natural and anthropogenic processes during the holocene. during modern times all the historic hills of rome have changed their shape. in the historic centre, many of the small natural hills have disappeared, flattened or buried up to the point that they can no longer be distinguished. and yet, as already seen (fig. 3), the most relevant part of the historical hills, i.e. those that have not undergone a complete demolition by human activities, is detectable. the anthropogenic modifications of natural processes and landforms have been relevant, in the city centre, at least since the 6th century bc when the serviane walls were built with tuff-rock blocks excavated from local quarries. when the urbanisation moved from the hills down to the plains, several land-reclamation works were put in place, among which the realisation of the cloaca maxima for the drainage of the velabrum minus. another significant roman-age anthropogenic change was the excavation of the saddle between the capitolino and quirinale hills. conversely, the removal of velia hill, located between the palatino and esquilino, was operated in ad 1932 (insolera, 2001). over two millennia, human activities, in addition to earthquakes, floods and other natural processes (berti et al., 2004), have progressively covered the surface of the historical city centre with layers of materials made up of the remains of collapsed buildings, rubbish and the ruins of ancient temples and monuments mixed with colluvium and alluvium. the tr embankments, built in the last century, now protect the city centre from flooding. before the urbanisation, the urbs territory was characterized by a rather dense hydrographic network, 123 fig. 4 panoramic view from the gianicolo hill to ne (refer to figure 2). the alluvial plain is visible in the middle of the picture, where the tiber river is marked by the horizontal belt of trees separating the trastevere and the campus martius districts. beyond the plain, the pincio and quirinale hills represent the higher portions of the city in this photo. in the background, the apennine chain. anthropogenic modifications to the aqua mariana stream (rome) whose channels drained the water of the respective watersheds. one of the most frequent forms in the context of those modified by human activities consists of partially filled river valleys, which have changed the shape of their natural valley section. these are valleys where the volume of anthropogenic deposits is often considerable, sometimes such as to reach a thickness equal to half (or even more) of the original altitude difference between the thalweg and the top of the slopes (fig. 5). this type of modified valley sections (sensu del monte et al., 2016) is well represented in the historical centre: in the east side of the tiber, the spinon valley (lanciani, 1881), between the palatino and the capitolino, that of the fosso labicano, downstream and upstream of the colosseum, the murcia valley, the valle giulia, further n, and other valleys of the monti parioli. also, to w of the tr, some valleys, such as the infernoaurelia valley (del monte et al., 2016), exhibit a similar configuration. another type of anthropogenic landform well represented in the territory of the historical centre is a "disappeared" form (sensu del monte et al., 2016), or rather an anthropogenic landform that completely obliterated the pre-existing natural valley. it is a mostly flat or weakly undulating surface, under which a valley lies buried by huge quantities of anthropogenic filling deposits. in this case, its obscured (or invisible, sensu clivaz & reynard, 2017) landform (the natural valley) was detected by the authors after a multi-temporal analysis of topographic maps and aerial photographs. its presence is more widespread e of the tiber. the two landform typologies (i.e. modified and obliterated valleys) are well represented just outside the city walls, along the upper part of the sant’agnese stream (fig. 2), which from porta pia and piazza fiume stretched for miles to ne, ending in the aniene river (see the valley in fig. 2) after passing viale libia (fig. 5). 5. the aqua mariana the most relevant human interventions on the drainage network have been realized in the southern part of the city centre, in the area drained, in ancient times, by the most important left tributary of the tr within the walls. its original path is known, with reasonable certainty, only downstream of the san giovanni basilica, and this valley stretch was covered by the ancient nodicus stream (lanciani, 1881; corazza & lombardi, 1995). conversely, in many historical maps of the period between the 16th century and the first decades of the 20th century, the watercourse was indicated as aqua mariana or improperly aqua crabra (frutaz, 1962, e.g. in fig. 6). according to such historical topographic maps, there is no doubt that the aqua mariana has represented for centuries the only important tributary on the east side of the tr within the walls. the aqua mariana stream originated from the volcanic system of the alban hills, near to the lake of castel gandolfo, being part of its centrifugal drainage network (fig. 7). from the marino village, close to the volcanic crater, the stream flowed to nw on the volcanic flank, down 124 fig. 5 the sant’agnese valley landforms depicted: a) in the igm 1924 topographic map (some 'disappeared valley' landforms, including the one at the waterhead section between porta pia and viale regina margherita, are highlighted), and b) in a recent topographic map (almost all the pre-existing valleys have disappeared, except for a few that were only partially filled by man-made deposits, so they are still recognizable although deeply modified). in both a and b: the red line in the lower-left corner marks the aureliane city walls; upper-left corner coordinates: 41° 56’ 03’’ n, 12° 29’ 37’’ e. luberti g.m. et al. to the san giovanni and porta asinaria gates (d in fig. 8, and fig. 9), located close to the san giovanni basilica (4th century ad). from that gate, the stream flowed s of the celio hill and out of the aureliane walls (whose whole circuit is shown in fig. 6), built in the 3rd century ad. at the porta metronia gate (c in fig. 8), it entered into the city. here, the stream direction varied to nw, passing in the murcia valley (b in fig. 8), the wide and long fluvial depression facing the tiber valley carved by the ancient nodicus stream and exploited by the romans for the circus maximus construction. the aqua mariana flowed into the tr (a in fig. 8), in front of tiber isle. for over a century the terminal stretch of the river has no longer been visible, due to urbanization interventions. archive resources attest that the aqua mariana was actually an artificial stream, created in the 12th century ad, diverting a tributary of the aqua crabra river (fig. 7), which was a natural stream, to the murcia valley and then to the tr. in ancient times, according to the medieval sources, the aqua crabra flowed to n, in the aniene river. the aqua crabra was reported by frontino, ‘curator of the waters’ at the time of vespasian, to be the third river of latium vetus in importance, after the tiber and 125 fig. 7 drainage network of the se suburban area of rome at the end of the 19th century ad. the red lines subdivide the portion of the tiber river basin represented in this image in three main sectors: sector xvii borders lower basin of the aniene river (including the aqua crabra); sector xviii indicates the treiarome mid-portion of the tiber river basin (including the aqua mariana subbasin); sector xix borders the lower basin of the tiber river, from rome to its delta. nord upward. (modified from ‘hydrographic map of the tiber-river basin’ (carta idrografica del bacino del tevere: anonymous, 1880) scale 1:259200, partial reproduction). fig. 6 the ad 1565 topographic map by bernardo gamucci, who depicted the ancient city (urbs). the aqua crabra (blue line) is drawn as the only tiber river tributary, as it actually was at the time of the author. (modified from frutaz, 1962). anthropogenic modifications to the aqua mariana stream (rome) the aniene rivers. therefore, it was judged by pope callistus ii to be suitable for ensuring the water needs of the city within the aurelian walls, given the shortage of water that had passed since the 6th century ad, because of the damage to the ancient aqueducts operated by the king of goths witiges. the water deviation from the aqua crabra was made in the morena area, using an underground section of the claudian aqueduct and, downwards, channelling the water into an artificial riverbed, mainly built on ancient abandoned river sections (lanciani, 1881; annoscia, 2007; bultrini, 2012; capelli, 2015). this hydrographic structure remained as previously described until the middle of the 20th century, when, because of floods affecting the urban area, the aqua mariana water was furtherly diverted to w, becoming part of the river basin of the fosso dell’almone-caffarella (capelli, 2015). after this second river deviation, the catchment area of the ancient nodicus, the tributary of the tr that ran through the murcia valley, therefore seemed to return to the dimensions represented by quilici (1990), and by corazza & lombardi (1995) (fig. 10). the geomorphological features and dimensions of the murcia valley, however, appear to conform to a much wider river basin (del monte et al., 2013, 2016). hence, the hypothesis that the original plano-altimetric configuration of the fluvial system belonging to the murcia valley and the nodicus is different, at the time of ancient rome, from 126 fig. 8 the urban portion of the aqua mariana stream, marked in blue, as depicted in the urbis ichnographiam map by nolli (1748b), here partially shown, modified. legend: a) its confluence into the tiber river; b) the murcia valley, where the circus maximus is located; c) the porta metronia gate; d) the porta asinaria gate. fig. 9 the aqua mariana stream flowing out of the aureliane walls, from the porta san giovanni white gate to the imperial-age porta asinaria towered gate. on the right, the vicolo delle tre madonne road. the toponyms are depicted in the presidenza del censo map, 1839 (in the upper right box, partial reproduction). photographer: anonymous, mid 1800s. luberti g.m. et al. those reconstructed and represented by different authors (quilici, 1990, fig. 10; corazza & lombardi, 1995; lombardi & corazza, 2008), seems to be reasonable. such a hypothesis is here argumented by geomorphological, archaeological and geological evidences. 5.1. geomorphological evidence the morphology of the murcia valley and minor valleys belonging to its river basin, as well as the development over time of the hydrographic network, undoubtedly derive from both the erosional fluvial action occurred up to the last glacial maximum and the subsequent sedimentation by a natural river system (del monte et al., 2013, 2016). at the bottom of the valley between the palatino and aventino hills (figs. 10, 11 and 12), the circus maximus would have found optimal positioning (fig. 8), thanks to the considerable width and the particular shape of the murcia valley (fig. 12). in the portion of the tr alluvial plain close to that valley, the velabra marshes were originally located, and after land reclamation the forum boarium was built in that flat area (figs. 10 and 11). the downstream confluence of the nodicus might have favoured a lowering of the fluvial current of the tiber, determining the sedimentation of solid load and the formation of the tiber isle (del monte et al., 2013). according to marra et al. (2018), the tiber isle origin might have been triggered by the eastward diversion and loss of energy of the tiber stream, as a consequence of the sudden collapse of the forum boarium area because of fault displacements. at this regard, it is to underline that the collapse of the forum boarium area would more likely have determined an increase in slope and fluvial power, favouring the erosion upstream. conversely, fluvial deepening effects can be observed just downstream of tiber isle, e.g. on the west flank of the aventino hill. the eastward migration of the tiber stream might be simply due to the normal fluvial dynamics, during a free meandering phase. some reconstructions show (lombardi & corazza, 2008) the trunk of this ancient river system would seem to come from the area where the colosseum was built, i.e. from the narrow labicana valley that separates the oppio and palatino hills from the celio (fig. 10). numerous other sources (lanciani, 1881; quilici, 1990; corazza & lombardi, 1995) and the current morphology show instead that a wider valley section similar to that of the murcia valley – comes from se, along the same direction (fig. 10). thus, the valley located between the oppio-palatino and the celio, comparable in size to the spinon valley, would have been, in reality, travelled by a 127 fig. 10 the nodicus river basin (red line) as delineated according to the pre-urbanization topography reconstructed by quilici (1990). the red ‘m’ depicts the location of the ‘via la spezia’ site. anthropogenic modifications to the aqua mariana stream (rome) 128 fig. 11 the geological map drawn by giuseppe ponzi in 1850 (partial reproduction of the original sheet, ispra library). the map is useful to depict the landscape of the city centre. numbers and colours refer to the main lithologies: 1. volcanic tuffs (fuchsia); 2. sands and gravels (yellow). the light-blue colour around the tiber river represents the ‘level of the water at the ancient diluvium time’, even if the map shows the walls of the city. according to the author, at the ‘diluvium time’ the water level was some tens of metres above the presentday level of the tiber river, so covering the alluvial plains and the lower portions of the hills. luberti g.m. et al. small right tributary of the nodicus. 5.2. archaeological evidence according to lanciani (1881), the upstream portion of the murcia valley was actually travelled by the nodicus river, which, in the area that then hosted the baths of caracalla, received the contributions of many tributaries. the main trunk seems to come from the e (fig. 10), where, according to lanciani (1881) and gnoli (1939), there was a marshy area (palus decenniae), whose existence was later confirmed by archaeological excavations (demetrescu et al., 2011). such archaeological and geognostic investigations, connected to the construction of the metropolitan railway line c, highlighted frequent protohistoric floods in the area around the palus decenniae (fig. 10), confirming the hypothesis that a considerable water course passed, in antiquity, in the stretch between porta metronia and porta asinaria, just in correspondence of the artificial riverbed that would have been created for the outflow of the aqua mariana artificial stream (fig. 9). moreover, more recent archaeological investigations indicate that in the ‘via la spezia’ site (depicted in fig. 10) in the 3rd century bc a bank with a length of more than 130 m and direction ne-sw was put in place in order to defend roads and crops from the floods, and an artificial basin 70x35 m wide and with a mean depth of 2 m, dating 1st century ad, was revealed, about 15 m below the present-day ground level. it is the widest roman-age artificial basin that has ever been discovered. artefacts that were recovered within the basin suggest that it was both a water storage and fish farm basin. at the end of the 1st century ad the farm was abandoned and the basin filled with anthropogenic deposits. from the end of the 2nd to the beginning of the 4th centuries ad relevant land-reclamation works were made (ministero dei beni e delle attività culturali e del turismo ministry of cultural heritage and tourism, 2018). owing to the abovementioned evidence, it is reasonable to state that about two thousand years ago, this river had to be very important, both for the extension of its basin, and for river flow and power. 5.3. geological evidence the nodicus river, according to the geological evidence, had the greatest fluvial energy, compared with those of the other streams in the urbs. at the circus maximus a 12 m thick gravel stratum with thin interbedded clay layers was shortly described by signorini (1939). an erosional surface separates it by the underlying pliocene deposits. according to the interpretation given by ventriglia (1971), this body is part of the fluvial sedimentation that took place after the last glacial period, i.e. upper pleistocene-holocene. recently, marra et al. (2016) geochronologically determined that the deposition of the basal gravel stratum in the rome’s basin occurred between the last glacial termination and the meltwater pulse 1a (stanford et al., 2011), i.e. during the uppermost pleistocene. this stratum is generally up to 10-15 m thick, even in the tr urban sections (bozzano et al., 2000; marra et al., 2008, 2013). however, the gravel stratum is very often missing in most of the tiber tributaries s of the aniene confluence, or it is very thin. in the city centre, a less than 5 m thick gravel stratum was detected at the colosseum, but it is not clear whether it is referred to paleotiber gravels deposited at the beginning of middle pleistocene, as suggested by bozzano et al. (1995) or to the uppermost pleistocene deposits, as stated by pagliaroli et al. (2014). since corazza (2012) reported that gravels detected in a borehole located before the confluence of the colosseum stream in the murcia valley are just made of calcareous and siliceous centimetric clasts, whereas the gravels at the circus maximus are composed of both calcareous and siliceous, and tufaceous clasts up to 6-7 cm, it is more likely that only the gravels detected in the murcia valley are related to the upper pleistocene early sedimentation of materials partially eroded from volcanic rocks, whose massive eruptions started not before 600 ka (luberti et al., 2017). these geological data imply that the nodicus was surely the greatest river within the urbs, in terms of rate of flow and energy, with the obvious exception of the tiber. the thickness and the fining-upward stratigraphic succession of the whole mis 1 fluvial deposits in the murcia valley are similar to those of some downstream tiber’s tributaries that are characterised by much greater hydrographic basins. among them, in the fosso di vallerano valley ('f. di castello' in fig. 7), which is approximately 10 km s of the city centre, the uppermostpleistocene basal polygenic gravels up to 10 m thick were detected about 1 km from its confluence into the tr (bozzano et al., 2016). however, the fosso di vallerano basin, which originates from the alban hills close to 129 fig. 12 view of the murcia valley. the photo was taken from the terme di caracalla area (f.a.o. building) to n. anthropogenic modifications to the aqua mariana stream (rome) castel gandolfo village, is 67 km2 wide and its main stream is 23 km long. for comparison, the fosso di grottaperfetta basin, about 4 km s of the city centre, is 14 km2 wide and the length of its main stream is 11 km (ventriglia, 2002). in that valley several boreholes located about 1 km from the tiber plain detected a very thin gravel stratum up to 3 m thick just in the central portion of the upper pleistocene palaeovalley. moreover, the fining-upward deposits are characterised by several peat layers (cinti et al., 2008). 6. conclusions taking into account the evidence above discussed, it is reasonable to assume that the ancient fluvial basin belonging to the murcia valley was much wider than that inferable from the current topography and those reconstructed from the studies of quilici (1990) or simply represented in corazza & lombardi (1995), and lombardi & corazza (2008), all belonging to an area that is too limited. the main water course, before reaching the murcia valley, was very likely to follow the outflow direction then followed by the aqua mariana, the artificial channel that was built in the 12th century ad (fig. 7). in other words, pope callistus ii may have restored, we do not know how consciously, a natural outflow line, in the same place where it naturally developed and was still active at the time of romulus. the shape and size of the murcia valley, decidedly disproportionate to the modest dimensions of the water catchment area that can be deduced from the present day topographic map, confirm the importance of the ancient river that ran between the aventino and the celio-palatino up to about two thousand years ago. acknowledgements the authors thank the ministero dei beni e delle attività culturali e del turismo (mibact, ministry of cultural heritage and tourism) and the municipality of roma capitale for having provided information on archaeological preliminary results concerning the metropolitan railway line c. in addition, they are grateful to the associate editor adele bertini and the reviewers piero bellotti and emmanuel reynard for supportive comments and suggestions. the final manuscript benefited also from insightful suggestions from gabriella forno (university of turin). references annoscia g.m. (2007) fonti e strutture per la conoscenza del sistema idrico di roma nel medioevo. aracne ed., pp. 375. anonymous (1880) carta idrografica con l'indicazione dei principali affluenti del fiume tevere e delle stazioni metereologiche e idrometriche. tiber river watershed map, scale 1:259200, 1 sheet 90 x 61 cm, roma, lit. virano e teano. ascani f., bozzano f., buccellato a., del monte m., matteucci r., vergari f. (2008) evoluzione del paesaggio e antiche vie di drenaggio nell’area de “il castellaccio” (roma) da indagini geologiche, geomorfologiche e archeologiche. geologica romana, 41, 93-116. bellotti p., calderoni g., carboni m.g., di bella l., tortora p., valeri p., zernitskaya v. (2007) late quaternary landscape evolution of the tiber river delta plain (central italy): new evidence from pollen data, biostratigraphy and 14c dating. z. geomorphology, 126(4), 505-534. berti d., esposito e., giusti c., luberti g.m., piccardi l., porfido s., violante c., vittori e. (2004) geological setting, hazards and urban growth in some historical towns in italy. atti 32nd igc-firenze. memorie descrittive della carta geologica d’italia, 63(6), 1-72. bozzano f., funiciello r., marra f., rovelli a., valentini g. (1995) il sottosuolo dell’area dell’anfiteatro flavio in roma. geologia applicata e idrogeologia, 30(1), 405-422. bozzano f., andreucci a., gaeta m., salucci r. (2000) a geological model of the buried tiber river valley beneath the historical centre of rome. bulletin of engineering geology and the environment, 59, 121. bozzano f., lenti l., marra f., martino s., paciello a., scarascia mugnozza g., varone c. (2016) seismic response of the geologically complex alluvial valley at the “europarco business park” (romeitaly) through instrumental records and numerical modelling. italian journal of engineering geology and environment, 16(1), 37-55. doi: 10.4408/ijege.2016-01.o-04 bultrini e. (2012) l’acqua crabra: un fiume scomparso vicende del confine naturale tra roma e la civitas tusculana. archivio della società romana di storia patria, 135, 63-83. capelli g. (2015) la marrana dell’acqua mariana. un corso d’acqua al servizio dei papi. acque sotterranee italian journal of groundwater, asr15092, 79-82. doi: 10.7343/as-135-15-0162 cinti f.r., marra f., bozzano f., cara f., di giulio g., boschi e. (2008) chronostratigraphic study of the grottaperfetta alluvial valley in the city of rome (italy): investigating possible interaction between sedimentary and tectonic processes. annals of geophysics, 51(5,6), 849-865. clivaz m., reynard e. (2017) how to integrate invisible geo-morphosites in an inventory: a case study in the rhone river valley (switzerland). geoheritage. doi: 10.1007/s12371-017-0222-7 coarelli f. (2001) roma. guide archeologiche laterza, ed. laterza, roma, pp. 488. corazza a. (2012) analisi dei fattori di pericolosità geologica presenti nella città di roma attraverso l’esame di alcuni casi di studio. ph.d. thesis in environmental geology and geodynamics, a.y. 2011/2012, università degli studi di roma tre, pp. 282. http://hdl.handle.net/2307/3989. corazza a., lombardi l. (1995) idrogeologia dell'area del centro storico di roma. in: la geologia di roma: il centro storico. memorie descrittive della 130 luberti g.m. et al. carta geologica d’italia, 50, 179-211. corazza a., marra f. (1995) carta dello spessore dei terreni di riporto. in: la geologia di roma: il centro storico. memorie descrittive della carta geologica d’italia, 50, tav. 13. del monte m. (2017) aeternae urbis geomorphologia geomorphology of rome, aeterna urbs. in: soldati m., marchetti m. (eds) landscapes and landforms of italy. springer, cham, 339-350. doi: 10.1007/978-3-319-26194-2 del monte m., fredi p., pica a., vergari f. (2013) geosites within rome city center (italy): a mixture of cultural and geomorphological heritage. geografia fisica e dinamica quaternaria, 36 (2), 241-257. doi: 10.4461/gfdq.2013.36.20 del monte m., d’orefice m., luberti g.m., marini r., pica a., vergari f. (2016) geomorphological classification of urban landscapes: the case study of rome (italy). journal of maps, 12 (iss. sup1), 178-189, pls. 1. doi: 10.1080/17445647.2016.1187977 demetrescu e., fontana s., rea r. (2011) conoscenze pregresse e nuovi dati: l’evoluzione del paesaggio. in: cantieristica archeologica e opere pubbliche. la linea c della metropolitana di roma, tratta t4: stazioni san giovanni, lodi. indagini 20102011. mondadori electa, milano, 61-90. dupérac e. (1577) nova urbis romae descriptio. provided by the roma tre university, architecture dept. library. falda g.b. (1676) novissima et accuratissima delineatio romae veteris et novae. in viatorum usum et commoditatem excusa. one 500×590 mm sheet map. provided by the archivio capitolino, comune di roma. frutaz a.p. (1962) le piante di roma. istituto nazionale di studi romani, pp. 358. funiciello r., giordano g. (2008) la nuova carta geologica di roma: litostratigrafia e organizzazione stratigrafica. in: funiciello r., praturlon a., giordano g. (eds.) la geologia di roma dal centro storico alla periferia. memorie descrittive della carta geologica d’italia, 80(1), 39-85. gnoli u. (1939) topografia e toponomastica di roma medioevale e moderna. staderini editore, roma. heiken g., funiciello r., de rita d. (2005) the seven hills of rome. princeton university press, princeton, 264 pp. igm (1924) piano topografico di roma e suburbio, fogli 1-12. istituto geografico militare. maps surveyed in 1907, updated in 1924. scale 1:5000 maps, provided by the archivio capitolino, comune di roma. insolera i. (2001) roma fascista nelle fotografie dell’istituto luce. editori riuniti, roma, pp. 271. lanciani r. (1881) topografia di roma antica. i commentarii di frontino intorno le acque e gli acquedotti. memorie reale accademia lincei, ser. 3, 4, 215-614. lanciani r. (1893-1901) forma urbis romae. ulrico hoepli, 46 pls. lombardi g., corazza a. (2008) l’acqua e la città in epoca antica. in: la geologia di roma. dal centro storico alla periferia. memorie descrittive della carta geologica d’italia, 80 (1), 189-219. luberti g.m., marra f., florindo f. (2017) a review of the stratigraphy of rome (italy) according to geochronologically and paleomagnetically constrained aggradational successions, glacio-eustatic forcing and volcano-tectonic processes. quaternary international, 438(b), 40-67. doi: 10.1016/j.quaint.2017.01.044 marra f., florindo f., boschi e. (2008) history of glacial terminations from the tiber river, rome: insights into glacial forcing mechanisms. paleoceanography, 23(2), 1-17. doi: 10.1029/2007pa001543 marra f., bozzano f., cinti f.r. (2013) chronostratigraphic and lithologic features of the tiber river sediments (rome, italy): implications on the postglacial sea level rise and holocene climate. glob. planet. change, 107, 157-176. doi: 10.1016/j.gloplacha.2013.05.002 marra f., rohling e.j., florindo f., jicha b., nomade s., pereira a., renne p.r. (2016) independent 40ar/39ar and 14c age constraints on the last five glacial terminations from the aggradational successions of the tiber river, rome (italy). earth planet sci. lett., 449, 105-117. doi: 10.1016/ j.epsl.2016.05.037 marra f., motta l., brock a.l., macrì p., florindo f., sadori l., terrenato n. (2018) rome in its setting. post-glacial aggradation history of the tiber river alluvial deposits and tectonic origin of the tiber island. plos one, 13(3). doi: 10.1371/journal.pone.0194838 marra f., rosa c. (1995) stratigrafia e assetto geologico dell’area romana in: la geologia di roma: il centro storico. memorie descrittive della carta geologica d’italia, 50, 49-118. mibact, ministry of cultural heritage and tourism (2018) san giovanni underground station, explanatory panels edited and organized by mibact and roma capitale. san giovanni metro c, exhibition hall, rome. moltke h.k.b. graf von (1852) carta topografica di roma e dei suoi contorni fino alla distanza di 10 miglia fuori le mura, indicante tutti i siti ed edifizii moderni ed i ruderi antichi ivi esistenti. eseguita coll’appoggio delle osservazioni astronomiche e per mezzo della mensola delineata sulla proporzione di 1:25.000 dal barone di moltke aiutante di campo di s.a. reale il principe enrico di prussia a roma negli anni 1845 e 1846. simone schropp e c°, berlino. map provided by the dpt. of earth sc., ‘sapienza’ university of rome. nolli g.b. (1748a) nuova pianta di roma data in luce da giambattista nolli l’anno mdccxlviii. alla santità di nostro signore papa benedetto xiv la nuova topografia di roma ossequiosamente offerisce e dedica l’umilissimo servo giambattista nolli comasco. map of 12 elements: 430/440×680/690 mm and 480×720 mm. provided by the archivio capitolino, comune di roma. 131 anthropogenic modifications to the aqua mariana stream (rome) nolli g.b. (1748b) roma: silvio valenti tit. s. callix. presb. s. r. e. card. camerario benedicti 14. p. m. administro urbis ichnographiam a leonardo bufalino ligneis formis evulgatam servata proportione contractam atque aeri incisam jo. baptista nolli inc. franc. monaco & carol. nolli. map of one sheet. provided by the archivio capitolino, comune di roma. pagliaroli a., quadrio b., lanzo g., sanò t. (2014) numerical modelling of site effects in the palatine hill, roman forum, and coliseum archaeological area. bulletin of earthquake engineering, 12(3), 1383-1403. pica a., vergari f., fredi p., del monte m. (2016) the aetena urbs geomorphological heritage (rome, italy). geoheritage, 8(1), 31-42. doi: 10.1007/s12371-015-0150-3 pica a., reynard e., grangier l., ghiraldi l., perotti l., del monte m. (2017) geoguides, urban geotourism offer powered by mobile application technology. geoheritage, 10(2), 311-326. doi: 10.1007/s12371-017-0237-0 ponzi g. (1850) geologia del bacino di roma. geologic map enclosed to: ponzi g., sulla storia fisica del bacino di roma: memoria di giuseppe ponzi da servire da appendice all'opera il suolo fisico di roma di g. brocchi. roma: tip. delle belle arti, pp. 24. presidenza del censo (1839) carta topografica del suburbano di roma, desunta dalle mappe del nuovo censimento e trigonometricamente delineata nella proporzione di 1.15000 per ordine dell’e.mo e r.mo principe sig. cardinale gio. francesco falzacappa. stato pontificio, roma. provided by the archivio capitolino, comune di roma. 132 quilici l. (1990) forma e urbanistica di roma arcaica. in: cristofani m., la grande roma dei tarquini. catalogo della mostra in roma, 12 giugno 30 settembre 1990, l’erma di bretschneider, roma, 28-44. signorini r. (1939) risultati geologici della perforazione eseguita dall’agip alla mostra autarchica del minerale nel circo massimo di roma. bollettino della società geologica italiana, 63., fasc. 2-3, 13. stanford j.d., hemingway r., rohling e.j., challenor p.g., medina-elizalde m., lester a.j. (2011) sea -level probability for the last deglaciation: a statistical analysis of far-field records. glob. planet. change, 79, 193-203. doi: 10.1016/j.gloplacha.2010.11.002 ventriglia u. (1971) geologia della città di roma. amministrazione provinciale di roma, pp. 417. ventriglia u. (2002) geologia del territorio del comune di roma. amministrazione provinciale di roma, pp. 810. ms. received: march 3, 2018 final text received: september 3, 2018 luberti g.m. et al. amq sr003 viganòscafidi 149-156.pub earthquake locations and their interpretation: bridging the gap between seismological data and geological phenomena. alfio viganò 1, davide scafidi 2 1 servizio geologico, provincia autonoma di trento, trento, italy. 2 dipartimento di scienze della terra, dell’ambiente e della vita, università degli studi di genova, genova, italy. corresponding author: a. viganò <alfio.vigano@provincia.tn.it> abstract: a methodological view on earthquake locations and their geological interpretation is presented. seismicity is considered a potential trigger and/or predisposing factor for different geological phenomena, like landslides or surface deformation and ruptures. assuming a physical based model of earthquake nucleation, which in turn is supported by the observation of exhumed faults, earthquake locations from seismicity datasets need to be as much as possible reliable (i.e., precise and accurate) and complete. application examples on seismicity distributions and other natural/anthropic events for the central-eastern alps (ne italy) clarify some critical points of numerical calculations and suggest a critical approach for appropriate data interpretation. keywords: earthquakes, seismic catalogues, data reliability, landslides, southern alps. available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 33 (2), 2020, 149-156 1. introduction earthquakes are the certain evidence of presentday deformation of the lithosphere and part of the energy they release, called radiated energy, reaches the earth’s surface in the form of seismic waves (e.g., kanamori & rivera, 2006). this energy quote is responsible for ground shaking and a variety of geological phenomena, such as surface deformation and rupture, rock damaging, landslide triggering, as well as impacts on people and infrastructures (e.g., keefer, 1984; boncio et al., 2010; gischig et al., 2016; ivy-ochs et al., 2017). in particular, seismic waves can both trigger, as co-seismic causes, or affect, in the sense of predisposing factors, different types of phenomena (e.g., boncio et al., 2010; gischig et al., 2016; ivy-ochs et al., 2017). for this reason, earthquake catalogues and reliable seismicity databases (e.g., chiarabba et al., 2015; viganò et al., 2015; bressan et al., 2016; guidoboni et al., 2018; rovida et al., 2019) are extensively used as reference data to study and interpret these geological phenomena and other seismotectonic features (e.g., livio et al., 2014; lu et al., 2017; avital et al., 2018). regarding seismicity datasets, earthquake locations are the crucial information. in fact, the reliable estimation of hypocentral solutions is needed to accurately estimate magnitudes (e.g., bormann, 2012), calculate focal mechanisms (e.g., viganò et al., 2008; reiter et al., 2019) and evaluate all the parameters related to hypocentral distance and seismic-ray tracing (attenuation and tomography; e.g., morasca et al., 2010; viganò et al., 2013). this is valid not only for instrumental but also historical catalogues, which permit to significantly extend the temporal range under consideration (guidoboni et al., 2018; rovida et al., 2019). for this reason, end-users should be completely aware of limits and strengths of earthquake catalogues, paying attention to the assumptions given during their creation and the constraints often made explicit by the authors themselves (see discussion in wells & coppersmith, 1994). here we present a methodological discussion on earthquake locations from seismicity catalogues and their common use for geological interpretation. we propose specific points, as a sort of minimum baggage of knowledge for non-seismologists, and we discuss some commonly accepted approaches and procedures to highlight their possible critical points. an introductory conceptual description of the earthquake source, together with some application examples about the trentino region (ne italy) are also presented. 2. earthquake physics earthquake nucleation directly deals with rock mechanics and shear/tensile failure (e.g., scholz, 2002; vavry�uk, 2011). dynamic instabilities (i.e., related to non-stable conditions in a state where acting forces are known) generate earthquakes both in the brittle (i.e., upper lithosphere) and ductile fields, because shocks are the result not only of brittle failure but also of plastic instabilities or catastrophic phase changes (ranalli, 1995). for example, self-localizing thermal runaway has been proposed to justify intermediate-depth earthquakes (john et al., 2009). this points to the fact that «the critical stress (yield strength) and the mode of failure are functions of intrinsic and extrinsic rheological parameters» (ranalli, 1995, p. 90), where rheology means deformation and flow of matter. intrinsic parameters are https://doi.org/10.26382/amq.2020.06 150 viganò a., scafidi d. related to the property of the body (i.e., rock) and thus called material parameters, such as rigidity, compressibility, viscosity. on the contrary, extrinsic parameters are temperature, pressure and time. material parameters change at varying extrinsic conditions. seismicity is strongly dependent on the thermorheological behaviour of rocks and is critically conditioned by extrinsic rheological parameters. for this reason, a great effort is made to estimate the temperature distribution along depth within the lithosphere (e.g., viganò et al., 2012). this means that thermo-rheological boundaries, intended as delimiting volumes of different intrinsic and/or extrinsic parameters, are important drivers for deformation and earthquake nucleation. a “fault” is not, or at least not only, simply a sliding plane with dislocated blocks (basic model in figure 1), but the rock volume where acting forces govern the existence of dynamic instabilities as a function of rheological parameters, which in turn could significantly vary in space and time. within this conceptual framework, seismicity can only partially fill planar surfaces in depth, being mostly located depending on crustal heterogeneities due to different crack density distributions (bressan et al., 2016). crustal heterogeneities can be accordingly interpreted as due to lithological variations and different levels of fracturing and/or presence of fluids (viganò et al., 2013). all the above considerations have feedback in the observation of exhumed fault. in fact, fault patches and splay faults (i.e., branch of faults) spread displacement over large volumes (advanced model in figure 1) (e.g., scholz, 2002; sibson, 2003). exhumed faults show very complex structures and are composed of different types of rocks (cataclasites, pseudotachylytes; sibson & toy, 2006; viganò et al., 2011), which are the result of the mechanical and fluid flow properties of the fault zone (smith et al., 2013) (real fault in figure 1). 3. earthquake location the first goal of seismology is to locate the earthquake, that is calculate where and when the initial seismic rupture occurs within the rock volume (focus or hypocentre). considering the existence, uniqueness and stability of solutions, this inverse problem is ill-posed (hadamard, 1923). as usually happens in geophysics (boaga, 2016), accepted its existence (i.e., earthquake has occurred), the solution is unstable and above all not unique. viganò et al. (2015) showed that earthquake locations from different regional bulletins can differ significantly (several kilometres between epicentres) and therefore robust and detailed relocations are needed to constrain seismotectonic interpretations. this effect is the result of several causes. at first, station coverage, because recording stations must be in sufficient number and homogeneously distributed around the epicentral area. in seismological terms, it translates to a minimum number of available phase readings (for pand swaves) and to a minimum gap value (largest azimuthal separation in degrees between nearby stations as seen from the epicentre; e.g., gap <180°). secondly, crustal (or earth) models, because different assumptions on p and s-wave velocities bring to relevant discrepancies between theoretical and observed phase arrivals times. the critical effect of an appropriate crustal velocity model in areas affected by strong lateral heterogeneities of seismic velocities has been presented by viganò et al. (2015) for the trentino region. thirdly, calculation codes. among all, hypoellipse (lahr, 1999) and nonlinloc (lomax et al., 2000) are used worldwide and should be fig. 1 fault models with different degree of conceptual complexity. in the basic model, the fault is a planar surface where stresses acting on the fault plane (�, normal stress; �, shear stress) and pore fluid pressures inside the fault (�p) are responsible for the seismic rupture. a more advanced model considers contiguous rupture patches, together with lateral splay faults and cataclastic bands (scholz, 2002). in the real case (canalone porta fault in carbonates; viganò et al., 2011), a complex structure (slip zone, fault core, damage zone; sibson, 2003) and different types of rocks can be observed (cataclasites and pseudotachylytes). 151 earthquake locations and their geological interpretation mentioned because of the different mathematical approaches and consequent results (see discussion in viganò et al., 2015). earthquake focal solutions are usually listed and grouped into seismic bulletins or earthquake catalogues. the computed hypocentral parameters include firstly the origin time, expressed as hour, minutes, seconds, and possibly hundredths of seconds, in utc/gmt time (coordinated universal time/greenwich mean time). the focus is univocally located by latitude, longitude and depth, the last implicitly given not considering topography (positive downward, starting from 0 m a.s.l.). magnitude, with explicit magnitude type (e.g., local magnitude ml, duration magnitude md, moment magnitude mw, etc.), completes the initial set of parameters. however, parameters describing the solution quality are also necessary. they are often expressed as spatial maximum errors in kilometres (horizontal and vertical errors, erh and erz) and temporal uncertainties in seconds (root mean square travel-time residual, rms) (bormann, 2012). additional parameters could be the number of phases used, or total covariance if probabilistic methods are applied (lomax et al., 2000). particular attention should be payed when historical catalogues are examined (guidoboni et al., 2018; rovida et al., 2019). since numerical models cannot be obviously applied in this case, besides origin time and epicentral coordinates the most robust information is intensity (epicentral and/or maximum) instead of magnitude. magnitude is usually inferred from intensity using empirifig. 2 examples of seismicity distribution, with location errors (red bars): hypocentres with small errors and not aligned (cross-section ab), hypocentres with small errors and aligned (cross-section c-d), hypocentres with larger errors (cross-section e-f). tn, trento. cal formulae and expressed as equivalent magnitude based on macroseismic observations (me; guidoboni et al., 2019). 4. application examples in this section, some case studies about seismological data interpretation are presented. all of them concern the central-eastern alps (ne italy; map in figure 2). as highlighted before, the interpretation of seismicity distribution needs a careful evaluation of location quality and errors. figure 2 shows three cross-sections where three groups of hypocentres (data from viganò et al., 2015) lead to different geological explanations, based on the variable level of data accuracy. in the first case, location errors are limited to a few kilometres and computed solutions at depth are very well constrained (cross section a–b of figure 2). despite this, hypocentres do not indicate clear alignments, suggesting the occurrence of a widespread deformation within a crustal body. as already discussed by viganò et al. (2015), within this volume important earthquakes occur (e.g., 29 oct 2011, ml 4.4), which can be interpreted as due to local stress accumulation and the presence of two intersecting regional fault systems, the giudicarie fold-andthrust belt and the schio-vicenza high-angle faults. in the second case, earthquake foci are vertically aligned along the veneto alpine front, in optimal agreement with the montagna nuova strike-slip fault (cross section c–d of figure 2). location accuracy is the same of the first case study. both vertical alignment and relatively small errors thus allow a complete seismological/geological interpretation. in the third case, larger horizontal and vertical errors pose a limit in the geological interpretation (cross section e–f of figure 2). in fact, it is not possible to undoubtedly distinguish between a volume-clustered seismicity and earthquakes filling a plane. figure 3 shows the effect of different computational methods in quarry shot locations, but the following considerations can be extended also to seismicity. using 1d simplified velocity models and the hypoellipse code (lahr, 1999) wrong locations at depth (i.e., imprecise) are achieved, with also unreliable minimal location errors (i.e., falsely accurate). in fact, computed errors do not permit to include the true shot locations (see numerical values in table 1). in contrast, 3-d advanced velocity models and nonlinloc probabilistic solutions (lomax et al., 2000) are able to correctly locate the events and, despite the larger computed errors (given by the nonoptimal station coverage density), to obtain highly reliable solutions. in fact, unlike tectonic earthquakes, in this case location reliability can be directly evaluated considering the true shot locations. this application example shows that, firstly, location approaches must be fully expressed by authors in catalogues and fully understood by end-users to correctly use the given solutions. secondly, smaller location errors do not necessarily mean better quality solutions. however, it should keep in mind 152 fig. 3 map and cross-section of quarry shot locations (the area is about 10 kilometres ne of the city of trento; cf. figure 2), with solutions obtained using 1d (method 1, black dots; hypoellipse code; lahr, 1999) and 3d velocity models (method 2, red stars; nonlinloc code; lomax et al., 2000). location errors are also shown (black bars) (modified from viganò et al., 2015). viganò a., scafidi d. that also advanced location methods (e.g., nonlinloc) can unreliably locate earthquakes, if not well constrained due to all the considerations given above (e.g., station coverage, velocity model). similar considerations can be done for the location of another type of geological phenomena at the earth’s surface. the cima undici rockfall, which moved about 75,000 m3 of limestones (scafidi et al., 2018), can be properly located only if the most reliable computational method for the area is applied (table 1). it should be also considered that seismic recordings related to landslides significantly differ from those of tectonic earthquakes, especially in terms of frequency content and duration. in fact, landslide spectrograms (i.e., spectra of frequencies at varying time) have a typical triangular shape, higher frequencies decay more rapidly, and the main energy content is usually found within a typical 1-5 hz range (e.g., dammeier et al., 2011; provost et al., 2018). also in the cima undici case study, a direct comparison between real and computed solutions can be performed. in contrast, since earthquake locations are necessarily given as they are and testing of the location procedure is not always possible (cf. viganò et al., 2015), a complete and thoughtful analysis on data must be performed previously they are used and interpreted. moreover, a complete check of available seismological data should be done by end-users, as a function of the geological phenomena they are dealing with. as an example, for landslides, a complete magnitude calculation (i.e., together with its computed, not broadly estimated, uncertainty value) is particularly important because crucial to apply regression curves on moved mass (manconi et al., 2016). 5. discussion and conclusions the geological interpretation of seismological data is not straightforward (e.g., barchi & mirabella, 2009). too simplistic interpretations can be given, considering 153 locations without discussing their precision and accuracy. as a typical example, the use of hypocentres (or even epicentres only) to infer the existence of a fault in depth or to demonstrate the present activity of a geologically-known tectonic structure. in general, a comprehensive analysis should firstly consider seismological data already available for the study area, in order to collect information and select the adequate database (figure 4). as a very preliminary but not obvious consideration, the number of significant digits on location parameters must be evaluated. one degree of latitude and longitude, for example in the trentino region (cf. figure 2), measure about 111 and 78 km, respectively. so, three decimal digits for latitude and longitude degree values mean about 0.1 km in both the cases. since location errors for earthquakes are typically larger than 1 km, a number of significant digits greater than 3 essentially does not make sense and is severely misleading. geological interpreters must properly consider location coordinates with errors and, consequently, plot epicentral distributions. similar considerations on significant digits should be clearly done also for all the other solutions parameters (i.e., depth, errors themselves, etc.). as mentioned before, it should be emphasized that seismic network configuration plays a crucial role in location solutions and their quality assessment. in particular, many parameters act jointly, such as the total number of stations and their epicentral distance, azimuthal gap, and the presence of at least one recording station relatively near the epicentre (e.g., bondár et al., 2004; tiira et al., 2016). then, a possibly complete identification of the geological phenomena should be done, with also the estimation of their uncertainties on, for example, mechanisms, driving factors and age (figure 4). this leads to the core phase, where earthquake locations are used and interpreted. assuming in-depth analyses on data, method and solution quality (for instrumental seismicity), any interpretation must be conceptually (i.e., within the earthquake locations and their geological interpretation tab. 1 real and computed locations for two events occurred at the earth’s surface (fornace quarry shot and cima undici rockfall). “method 1” is given by hypoellipse code (lahr, 1999) and 1-d velocity model; “method 2” is given by nonlinloc code (lomax et al., 2000) and 3-d velocity model. erh, horizontal error; erz, vertical error; rms, root mean square; ml, local magnitude (with computed uncertainty). range of theoretical applicability) and quantitatively (i.e., within value uncertainties) consequential from seismological data. in other words, we must make sure that we do not let the data say what they cannot say. finally, data reliability concerns not only about precision and accuracy, but also completeness (figure 4). as an example, if we would like to make a selection on historical seismicity for the central-eastern alps to be compared to catastrophic landslides in this region (cf. ivy-ochs et al., 2017), we must consider the most complete catalogues (cfti5med by guidoboni et al., 2018; cpti15 vers. 2 by rovida et al., 2019). if we uncritically plot epicentral coordinates from cfti5med and cpti15 we obtain two different results. in the first case, we include the most relevant historical earthquake in southern trentino (the “middle adige valley” event, 1046 ad). in the second case, we completely miss it (the earthquake is listed but not completed with epicentral coordinates, due to specific choices in event selection). in conclusions, final remarks can be summarized as follows: �� a complete and appropriate use of earthquake locations is a difficult task, because both their calculation is an ill-posed inverse problem and their geological interpretation is not straightforward. �� rheological theory on earthquake nucleation and realistic conceptual models of faults imply a careful analysis of seismicity datasets, in terms of data, method and solution quality, to assess their overall reliability. �� a comprehensive check-list for non-seismologists is able to support data interpretation, in order to better explain geological phenomena and avoid some commonly accepted critical points. 154 fig. 4 comprehensive check-list for earthquake location data analysis and interpretation. viganò a., scafidi d. lease of the catalogue of strong earthquakes in italy and in the mediterranean area. scientific data, 6:80. doi: 10.1038/s41597-019-0091-9 hadamard j. (1923) lectures on cauchy’s problem in linear partial differential equations. dover phoenix editions. dover publications, new york, pp. 22. ivy-ochs s., martin s., campedel p., hippe k., alfimov v., vockenhuber c., andreotti e., carugati g., pasqual d., rigo m., viganò a. (2017) geomorphology and age of the marocche di dro rock avalanches (trentino, italy). quaternary science reviews, 169, 188-205. john t., medvedev s., rüpke l.h., andersen t.b., podladchikov y.y., austrheim h. (2009) generation of intermediate-depth earthquakes by selflocalizing thermal runaway. nature geoscience, 2, 137-140. kanamori h., rivera l. (2006) energy partitioning during an earthquake. in: abercrombie r., mcgarr a., di toro g., kanamori h. (eds.) earthquakes: radiated energy and the physics of faulting. geophysical monograph, 170, 3-13. keefer d.k. (1984) landslides caused by earthquakes. geological society of america bulletin, 95, 406421. lahr j.c. (1999) hypoellipse: a computer program for determining local earthquake hypocentral parameters, magnitude, and first-motion pattern (y2k compliant version). u.s.g.s. open file report 9923, pp. 116. livio f.a., berlusconi a., zerboni a., trombino l., sileo g., michetti a.m., rodnight h., spötl c. (2014) progressive offset and surface deformation along a seismogenic blind thrust in the po plain foredeep (southern alps, northern italy). journal of geophysical research, solid earth, 119, 7701-7721. lomax a., virieux j., volant p., berge-thierry c. (2000) probabilistic earthquake location in 3d and layered models: introduction of a metropolis–gibbs method and comparison with linear locations. in: thurber c. h., rabinowitz n. (eds.) advances in seismic event location. kluwer, amsterdam, 101134. lu y., waldmann n., alsop g.i., marco s. (2017) interpreting soft sediment deformation and mass transport deposits as seismites in the dead sea depocenter. journal of geophysical research, solid earth, 122, 8305-8325. manconi a., picozzi m., coviello v., de santis f., elia l. (2016) real-time detection, location, and characterization of rockslides using broadband regional seismic networks. geophysical research letters, 43, 6960-6967. morasca p., massa m., laprocina e., mayeda k., phillips s., malagnini l., spallarossa d., costa g., augliera p. (2010) improved 2-d attenuation analysis for northern italy using a merged dataset from selected regional seismic networks. journal of seismology, 14, 727-738. provost f., malet j.-p., hibert c., helmstetter a., radiguet m., amitrano d., langet n., larose e., abancó c., hürlimann m., lebourg t., levy c., le acknowledgements gianni bressan is gratefully acknowledged for inspiring many considerations presented in this paper. we also thank j. boaga and m. ostermann for their helpful comments and suggestions. references avital m., kamai r., davis m., dor o. (2018) the effect of alternative seismotectonic models on psha results a sensitivity study for two sites in israel. natural hazards and earth system sciences, 18, 499-514. barchi m.r., mirabella f. (2009) the 1997-98 umbriamarche earthquake sequence: “geological” vs. “seismological” faults. tectonophysics, 476, 170179. boaga j. (2016) the ill-posed problem in geophysics. atti del workshop in geofisica, 3-4 dicembre 2015, rovereto, 3-12. boncio, p., pizzi a., brozzetti f., pomposo g., lavecchia g., di naccio d. (2010) coseismic ground deformation of the 6 april 2009 l’aquila earthquake (central italy, mw6.3). geophysical research letters, 37. doi: 10.1029/2010gl042807 bondár i., myers s.c., engdahl e.r., bergman e.a. (2004) epicentre accuracy based on seismic network criteria. geophysical journal international, 156, 483-496. bormann p. (2012) new manual of seismological observatory practice (nmsop-2), iaspei. gfz german research centre for geosciences, potsdam. http://nmsop.gfz-potsdam.de bressan g., ponton m., rossi g., urban s. (2016) spatial organization of seismicity and fracture pattern in ne italy and w slovenia. journal of seismology, 20, 511-534. chiarabba c., de gori p., mele f.m. (2015) recent seismicity of italy: active tectonics of the central mediterranean region and seismicity rate changes after the mw 6.3 l’aquila earthquake. tectonophysics, 638, 82-93. dammeier f., moore j.r., haslinger f., loew s. (2011) characterization of alpine rockslides using statistical analysis of seismic signals. journal of geophysical research, earth surface, 116. doi: 10.1029/2011jf002037 gischig v., preisig g., eberhardt e. (2016) numerical investigation of seismically induced rock mass fatigue as a mechanism contributing to the progressive failure of deep-seated landslides. rock mechanics and rock engineering, 49, 2457-2478. guidoboni e., ferrari g., mariotti d., comastri a., tarabusi g., sgattoni g., valensise g. (2018) cfti5med, catalogo dei forti terremoti in italia (461 a.c.-1997) e nell’area mediterranea (760 a.c.1500). istituto nazionale di geofisica e vulcanologia (ingv) doi: 10.6092/ingv.it-cfti5 guidoboni e., ferrari g., tarabusi g., sgattoni g., comastri a., mariotti d., ciuccarelli c., bianchi m. g., valensise g. (2019) cfti5med, the new re 155 earthquake locations and their geological interpretation roy g., ulrich p., vidal m., vial b. (2018) towards a standard typology of endogenous landslide seismic sources. earth surface dynamics, 6, 1059-1088. ranalli g. (1995) rheology of the earth. second ed. chapman & hall, london, pp. 413. reiter f., freudenthaler c., hausmann h., ortner h., lenhardt w., brandner r. (2019) active seismotectonic deformation in front of the dolomites indenter, eastern alps. tectonics, 37, 4625-4654. rovida a., locati m., camassi r., lolli b., gasperini p. (2019) catalogo parametrico dei terremoti italiani (cpti15), versione 2.0. istituto nazionale di geofisica e vulcanologia (ingv). doi: 10.13127/cpti/cpti15.2 scafidi d., viganò a., ferretti g., spallarossa d. (2018) robust picking and accurate location with rsnipicker2: real-time automatic monitoring of earthquakes and nontectonic events. seismological research letters, 89, 1478-1487. scholz c.h. (2002) the mechanics of earthquake and faulting. second ed. cambridge university press, pp. 471. sibson r.h. (2003) thickness of the seismic slip zone. bulletin of the seismological society of america, 93, 1169-1178. sibson r.h., toy v.g. (2006) the habitat of faultgenerated pseudotachylyte: presence vs. absence of friction-melt. in: abercrombie r., mcgarr a., di toro g., kanamori h. (eds.) earthquakes: radiated energy and the physics of faulting. geophysical monograph, 170, 153-166. smith s.a.f., bistacchi a., mitchell t.m., mittempergher s., di toro g. (2013) the structure of an exhumed intraplate seismogenic fault in crystalline basement. tectonophysics, 599, 29-44. tiira t., uski m., kortström j., kaisko o., korja a. (2016) local seismic network for monitoring of a potential nuclear power plant area. journal of seismology, 20, 397-417. vavry�uk v. (2011) tensile earthquakes: theory, modeling, and inversion. journal of geophysical research, solid earth, 116. doi: 10.1029/2011jb008770 viganò a., bressan g., ranalli g., martin s. (2008) focal mechanism inversion in the giudicarie– lessini seismotectonic region (southern alps, italy): insights on tectonic stress and strain. tectonophysics, 460, 106-115. viganò a., tumiati s., recchia s., martin s., marelli m., rigon r. (2011) carbonate pseudotachylytes: evidence for seismic faulting along carbonate faults. terra nova, 23, 187-194. viganò a., della vedova b., ranalli g., martin s., scafidi d. (2012) geothermal and rheological regime in the po plain sector of adria (northern italy). italian journal of geosciences, 131, 228240. viganò a., scafidi d., martin s., spallarossa d. (2013) structure and properties of the adriatic crust in the central-eastern southern alps (italy) from local earthquake tomography. terra nova, 25, 504-512. viganò a., scafidi d., ranalli g., martin s., della vedova b., spallarossa d. (2015) earthquake relocations, crustal rheology, and active deformation in the central-eastern alps (n italy). tectonophysics, 661, 81-98. wells d.l., coppersmith k.j. (1994) new empirical relationships among magnitude, rupture length, rupture width, rupture area, and surface displacement. bulletin of the seismological society of america, 84, 974-1002. 156 viganò a., scafidi d. ms. received: june 29, 2020 revised: august 10, 2020 accepted: august 10, 2020 available online: november 30, 2020 amq_gianotti 23022015 h013 available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 28 (1), 2015, 29 58 stratigraphy of the ivrea morainic amphitheatre (nw italy): an updated synthesis franco gianotti1, maria gabriella forno1, susan ivy-ochs2, giovanni monegato3, roberta pini4 & cesare ravazzi4 1earth science department, university of torino, torino, italy 2ion beam physics, eth honggerberg, zürich, switzerland 3c.n.r. institute of geosciences and earth resources, torino, italy 4c.n.r. idpa. res. group vegetation, climate and human stratigraphy, lab. of palynology and palaeoecology, milano, italy corresponding author: f. gianotti <franco.gianotti@unito.it> abstract: the ivrea morainic amphitheatre (ima) is the main evidence of quaternary glaciations in the dora baltea basin (nw italy). this end moraine system forms a 500 km2 wide complex of lateral and terminal moraines and kame terraces, dated from the end of the early pleistocene (on palaeomagnetic basis) to the end of the late pleistocene (14c radiometric and 10be exposure ages). a synthesis of the state of the art on the ima stratigraphy is presented, based on the previous literature and reinterpreted in the light of new surveys and dating. some embedded palaeosols and palustrine deposits within the glacigenic sequences, interpretable the first as interglacial layers and the latter as interglacial or interstadial layers, crop out along stream incisions cutting the ima outer and inner edges or were sampled through boreholes (alice superiore and torre canavese cores). the top of the deposits shows different degrees of weathering and they can be distinguished into three pedogroups based on the hue index color of the soil horizons. buried stratigraphical markers and pedogroups together allowed the subdivision of the glacigenic succession into nine stratigraphic units (mongrando, bornasco, montino and zubiena synthems, grouped in the 2.5yr pedogroup; parogno and torrazzo synthems, grouped in the 5yr pedogroup; magnano, serra and ivrea synthems, grouped in the 7.5yr pedogroup). each synthem has been attributed to different glacial expansion. so a potentially complete glacigenic succession outcrops, which can be possibly correlated to the whole sequence of the main quaternary glaciations of the marine oxygen isotope stratigraphy from mis 22-20 to mis 2. the widest unit (serra synthem), related to the penultimate glaciation (mis 6), comprises the serra d’ivrea lateral moraines and is subdivided into two sub-units (external serra and internal serra subsynthems) on morphological grounds. the innermost unit (ivrea synthem) related to mis 2 is subdivided into 13 sub-units on morphological basis, corresponding to the height of the last glacial maximum (piverone subsynthem), to six lgm retreat stadials in amphitheatre (palazzo, quintas, pavone, bienca, prà san pietro and germano subsynthem) and six lgm-lateglacial stadials in the dora baltea valley. keywords: glacial stratigraphy, glaciations, end moraine system, pleistocene, western alps, lgm 1. introduction morainic amphitheatres are the most direct evidence of the extent of mountain glaciers during pleistocene glaciations. these morainic reliefs are preserved in all of the middle latitude mountain chains. they form broad amphitheatres in the andes, in new zealand and in the european alps, and subordinately in the rocky mountains and in the chinese himalaya, i.e. where glaciers could spread out over the piedmont plains (ehlers & gibbard, 2004a, b, c). the ivrea morainic amphitheatre (ima) is located at the outlet of the aosta valley (fig. 1). among the end moraine systems of the southern side of the alps, the ima is well known for its remarkable geomorphology. it is one of the largest (505 km2) morainic amphitheatres, although smaller than the garda and verbano amphitheatres. it contains two distinctive morphological elements: 1) the serra d'ivrea lateral moraine, which is the highest expression of glacial sedimentation; 2) the ivrea hills (colli d’ivrea), where evidence of subglacial erosional processes is abundant. because of its morphological characteristics the ima was defined as the most considerable amphitheatre of the alpine glaciation (penck et al., 1894). also the stratigraphical features are particularly remarkable. the amphitheatre was apparently built during most of the interglacial-glacial cycles of the second half of the quaternary, as nine stratigraphical units have been distinguished (gianotti et al., 2008) related to as many main glacial expansions ranging in age from the end of the early pleistocene to the late pleistocene. the aim of the present work is to synthesize the state of the art about the ima stratigraphy, taking into account the long historical background proved by more than 100 geological publications starting from 1850 ad. 2. geological setting the ima is located in the western po plain at the outlet of the aosta valley, up to about 120 km from the present fronts of the monte bianco glaciers (fig. 1). the morainic hills are spread in the po plain for more than half of its width (24 km on a total of 42 km). the remnant space is filled mostly by the ima glaciofluvial sandur, forming a 500 km2 terraced system. the po river, the trunk river of the plain, flows within a 1.5-3 km large alluvial corridor between the rims of the frontal sandur and the northern slopes of the collina di torinomonferrato. the strong morphological evidence of the ima (fig. 2) is a consequence of the very elevated topography (mean elevation of 2100 m a.s.l. with 90% of the area lying above 1500 m a.s.l.) and the proximity of its mountain catchment area. the aosta valley is a 3350 km2 wide branched mountain basin, consisting of a 100 km long main valley (dora baltea valley) and of about thirty major tributary valleys. it is bounded by some of the highest peaks of the european alps, rising a short distance from the po plain. in detail monte bianco (4812 m) and gran paradiso (4061 m) are 95 km away from the valley outlet at borgofranco d’ivrea (250 m a.s.l.), where the ima begins, while cervino (4478 m) and monte rosa (4634 m) are only 60 and 45 km away, respectively. the altitude promotes the existence of several glaciers (209) with an overall present-day extent of approximately 135 km2 (aosta valley catalogue of glaciers, 2005), corresponding to 4.0 % of the basin. the dora baltea valley is deeply incised across the inner and axial sectors of the western alps. the latter are part of a typical collisional belt developed from the cretaceous by subduction of a mesozoic ocean and collision between the adriatic (austroalpine-southalpine) and european (penninic-helvetic) continental margins (dal piaz et al., 2003). with the partial exception of the nearby ossola-ticino valley system, the dora baltea is the only basin of the whole alps to cut all the main structural domains that constitute the alpine range, i.e. from the southern alps across the entire alpine axial belt (austroalpine and penninic units), up to the inner border of the external zone (helvetic units). the complex lithologic composition of the basin (elter, 1987; de giusti et al., 2004) is mirrored in the large petrographic variety of the glacigenic deposits found in the ima, made of silicate and subordinate carbonate metamorphic rocks. concerning the ima underlying rock, in its proximal sector the ima lies on metamorphic bedrock with formations spanning from the variscan (paleozoic) to the alpine (cretaceous oligocene) cycle (figs. 3a-b). in contrast, the middle and distal sectors of the ima rest on marine, transitional and alluvial sequences of zancleanearly pleistocene age (figs. 3c-f). this setting is typical of the big italian piedmont end moraine systems (i.e. rivoli-avigliana, verbano, lario, garda and tagliamento). the bedrock is comprised of continental crust of the adriatic plate, made of austroalpine eclogitic micaschists to the nw (sesia-lanzo zone; compagnoni et al., 1977; venturini, 1995) and of southalpine rocks to the se (ivrea-verbano zone and canavese zone). the fig. 1 geomorphological sketch map of the dora baltea basin, with the 3400 km2 wide mountain basin nearly corresponding to valle d’aosta region and the ima at the outlet of the valley (from gianotti et al, 2008, mod.). the present glaciers of the basin are shown. the bedrock crops out in the ima inner sector in the granulite ivrea hills (hi) and in the outer western sector in the monti pelati peridotite reliefs (mp). the serra d'ivrea moraine (se), the inner depression (id) and the outer outwash plain (op) are pointed out. the dora baltea river flows out of the ima through the mazzé gorge (ma). at the northeastern edge the bessa roman gold mines extend (be). the stura di lanzo (st) and cervo (ce) fan complexes spread laterally to the ima. lgm to lateglacial stadials in colli d’ivrea area and in the valley are shown. main morainic amphitheatres of italian alps (box at the bottom left): 1) rivoli-avigliana (susa valley); 2) ivrea (dora baltea valley); 3) orta (strona valley); 4) verbano (ossola+ticino valleys); 5) lario (valtellina and como lake); 6) iseo (camonica valley); 7) garda (adige-sarca valleys); 8) rivoli veronese (‘‘lagarina’’ valley); 9) tagliamento (tagliamento valley). fig. 2 panorama of the ima (view from the bric paglie slope at 1200 m a.s.l.) 30 gianotti f. et al. fig. 3 the various lithotypes that constitute the ima substrate. (a) basic granulite of the ivrea verbano zone forming the bedrock cropping out in the chiusella r. riverbed (ponte dei preti, strambinello). (b) polished and striated basic granulite in the ivrea hills (montalto dora). (c) zanclean fossiliferous marine sediments into the strambinello ls (peronetto, south of parella). (d) estuarine transitional sand and gravel cropping out into the borra grande incision (peronetto, south of parella). (e) fractured villafranchian sandy silt, recently exposed into the elvo riverbed. (f) deeply weathered fluvial gravel referred to the pre-glacial dora baltea fan (cerrione synthem), cropping out in the valle sorda riverbed (west of cerrione). 31 stratigraphy of the ivrea morainic amphitheatre (nw italy) ... two systems meet along the external canavese line (ecl in figs. 4 and 5), that is part of the periadriatic line delimiting the internal edge of the alpine axial belt. this transversal fault marks the contact of the alpine high-pressure metamorphic rocks (austroalpine system) with the pre-alpine variscan basement (southalpine system) and morphologically separates the higher alpine range from the low ivrea hills. a second sub-parallel fault (the internal canavese line; icl in figs. 4 and 5) intersects the southalpine basement bringing the ivrea-verbano zone deep continental crust into contact with the canavese zone shallow continental crust. the canavese zone (biino & compagnoni, 1989) comprises a variscan, low-grade metamorphic basement (schist) with permian granitic and dioritic intrusions and a permomesozoic sedimentary cover made of breccias, volcanics, quartzites and dolomites. the ivrea-verbano zone (zingg et al., 1990), forming the most of the ivrea hills, is here constituted by the permian ivrea gabbro batholith, re-equilibrated in highgrade mafic granulite facies (fig. 3a). faults and related fractures have promoted and guided subglacial erosion during glaciations. the tectonic constraints influenced the directions of glacial flow and the continuity of marginal forms, particularly at the outlet of the dora baltea valley, where the glacier split into glacial lobes that crossed the low watershed separating the dora baltea basin and the chiusella valley (fig. 4; see 3). the pliocene sedimentary succession lies on the metamorphic bedrock, ranging from marine to transitional sediments. remarkable outcrops of pliocene deposits are well known in the western internal sector of the ima, from the classical fossil-bearing sites (ponte dei preti and borra grande) into the strambinello lobe apparatus up to the rio borriana incision. the succession crops out for about 70 m of thickness (275-345 m a.s.l.) between pranzalito and pian torinetto on the right side of the t. chiusella incision (martinetto, 1998; basilici et al., 1998). a basal unit of fine sand with scarce gravel lenses, intensely bioturbated and with abundant fossil mollusc shells (fig. 3c) is referred to the infralittoral zone and dated to the zanclean-piacenzian boundary. they pass upwards to transitional sediments (fig. 3d) correlatable to the “villafranchian lower complex” of the villafranca d’asti type-area of piacenzian age (carraro, 1996; caramiello et al., 1996; forno et al., in press). whereas, a series of continental units, made up of deeply weathered fluvial sandy gravel, can be correlated to the “villafranchian upper complex” (lower pleistocene). they form wide terraces (named altopiani villafranchiani in bortolami et al., 1966) in the northeastern sector of the ima. carraro et al. (1991) distinguished four units of torrential coarse gravels linked to the pa fig. 4 the main glacial lobe (ls) and sub-lobe (ssl) systems are marked on the dtm of the ima by dashed white line (during internal serra stadial) and blue dashed line (during piverone stadial). other minor ls are reported (white numbers): riccardi (1), alice superiore (2), strambinello (3), pré lake (4), magnano (5), santo sudario (6), salussola (7). the locations of the drill cores used for stratigraphic reconstruction are mapped with red symbols (1: alice superiore; 2: torre canavese; 3: montalto dora). the erratic boulders dated with cosmogenic nuclide dating method are pointed out by white squares (i7 and i8 on the external serra crest; i1, i3 and i6 in the ivrea hills). black numbers indicate the spillway/glaciofluvial fan systems forming the proximal sandur. from east to west they are the spillways of cavaglià (1), dora morta (2), passo d'avenco (3), sapel da bras (4), bocca d'arbaro (5), suc (6), san maurizio (7), moncrivello (8), mazzè (9), valle della motta (10), the three opening of caluso (11), candia (12), barone canavese (13), montalenghe (14), outer taglio grosso (15), ronchi (16) and pramonico (17). letters indicates elements explained in the text. fig. 5 longitudinal profile of the ivrea amphitheatre with the serra of ivrea morainic group. the serra d’ivrea is morphologically divided into external serra (brown) and internal serra (blue). a deep glacial excavation hollow in correspondence of the canavese zone bedrock (black asterisk), whose bottom is below sea level, was discovered by means of a 270 m deep coring at montalto dora. the ivrea hills represent the threshold by which the aosta valley is perched above the po valley. 32 gianotti f. et al. laeo-elvo alluvial fan, forming fluvial terraces suspended at decreasing elevation above the current riverbeds: only the graglia unit and the underlying garabello unit pre-date the ima formation. the following muzzano unit is coeval with the first glacigenic unit of the ima (mongrando synthem) and the camburzano unit is referred to the middle pleistocene. southward in the bessa terrace a fluvial unit made of medium-fine gravel and sand crops out below the remnant glacigenic cover (fig. 3f). it is part of the pre-glacial dora baltea alluvial fan (cerrione unit), coeval with the pre-glacial elvo fan (graglia unit). these two heteropic units constitute the ima substrate in the outermost edge of its eastern sector (gianotti, 1993). other similar gravel and sand successions, of doubtful stratigraphic attribution, crop out in the dora baltea incision at mazzé and at the base of the high terrace scarp in the southeastern sector (brianco terrace between salussola and carisio) and in the southwestern sector (between foglizzo and aglié). 3. geomorphological setting of the ima the ima forms a huge complex of lateral and terminal moraines and kame terraces (300 km2) around a large internal depression (200 km2). this 500 km2 wide complex constitutes the amphitheatre sensu strictu (fig. 2). all around the ima there is an equally wide apron of glaciofluvial deposits forming a suspended plain, corresponding to the classical sandur of the end moraine systems. ima together with its proglacial sandur form a pleistocene glacigenic depositional system with an extent of over 1000 km2 genetically linked to the dora baltea /aosta valley basin. compared to the other alpine end moraine systems, the ima is characterized by: (i) the serra d’ivrea, an exceptionally regular and very long (16 km) lateral moraine, regarded as the biggest of the alps (penck & brückner, 1909); (ii) a very large fluvial plain occupying the internal depression; (iii) the ivrea hills, a 21 km2 wide sub-glacially moulded bedrock relief, rising on the internal plain. the spectacular landscape of the ima, that impressed many scientists (i.e. gastaldi defined it the most important geological evidence in the upper po valley) is based on the contrast between the flat internal plain and the surrounding high morainic reliefs, with a sharp difference of elevation reaching 700 m. the ima is constituted of four main morphological sectors: the morainic relief, the internal plain, the subglacially moulded ivrea hills and the external plain. the morainic relief shows numerous alignments (up to about 40 in the eastern sector) of ice marginal position landforms, corresponding to lateral and frontal moraines and kame terraces. in addition to the ancient sacco map (1938), only zienert (1970) carried out geomorphological analysis on the ima and identified 28 morainic circles. these landforms are arranged in 3 main glacial lobe systems (ls): viverone, settimo rottaro and vische. in the western sector of ima the smaller ls of alice superiore and strambinello are present (fig. 4). every one of them is constituted by a system of lateral and frontal moraines encircling an internal depression. the viverone ls comprises the serra d’ivrea, which forms its left lateral moraine, and surrounds the viverone lake (230 m a.s.l., max deep 58 m). the vische ls is the widest, is crossed along the entire length by the dora baltea river and is branched into three sub-lobes: the borgomasino sub-ls, with the mazzé gorge by which the dora baltea r. flows out the amphitheatre; the candia sub-ls encircling the candia lake (226 m a.s.l., 7.5 m deep); and the less evident villate sub-ls. the smallest settimo rottaro ls is comprised between the viverone and vische ls and has an inner plain derived from the filling of a palaeo-lake at the same elevation (230 m a.s.l.) of viverone lake. in the sector of the ima close to the valley outlet, the presence of the canavese zone influenced the path of smaller ice lobes in which the glacier was split. the alice superiore ls is clearly aligned with the external canavese line, which channelled and confined glacial erosion into the belt of fractured bedrock of the canavese zone. the strambinello lobe repeatedly dammed the outlet of the chiusella valley, causing the diffluence of the chiusella stream toward the sw to confluence with the orco river. the ivrea hills correspond to the southalpine basement outcropping over a wide area (21 km2) in the internal depression of the amphitheatre. they are a group of low hills with gentle smooth morphology, formed by subglacial erosion of the mafic granulite of the ivreaverbano zone (forno et al., 2005b, 2007). these hills represent the threshold of a glacial excavation hollow (fig. 5), cut by the dora baltea glacier into the fractured rocks of the canavese zone and reaching a depth below sea level (at least -20 m), as documented by the 270 m deep core of montalto dora (3 in fig. 4; forno et al., 2010). the internal plain is the most characteristic element of the ima, because other end moraine systems have their internal depressions occupied by a big lake and/or low moraines while the plain is subordinated. the ima internal depression is instead formed by a very wide fluvial plain distributed at two altitudinal levels: the alluvial plain and a series of fluvial terraces. the present alluvial plain, crossed by the dora baltea and chiusella rivers, extends for 23 km in nnw-sse direction throughout the inner basin from 250 m to 215 m a.s.l. and reaches a maximum length of 4 km. it is divided into two lowlands separated by the rocky ivrea hills, an obstacle that the dora baltea river crosses through a gorge at ivrea (ponte vecchio). the fluvial terraces are distributed all around the alluvial plain at heights of not more than 15 m higher than the lowlands. the external outwash plain is a high terraced proglacial sandur formed by a sequence of laterally interfingering glaciofluvial fans, each one originating from a different passage (spillway or sfioratore) across the moraine arcs (fig. 4). on the apical portion of the glaciofluvial fans the traces connected with the ancient mining activities for gold are still visible (gianotti, 2011). they are particularly evident in the bessa aurifodinae in the ima north-eastern sector (baio & gianotti, 1996). the main plain, linked to glaciofluvial activity during the two serra expansions, is suspended up to 60 m above the present -day dora baltea riverbed. in more distal positions several higher terraces are suspended up to 10 m over the main plain, corresponding to the terraced relicts of more 33 stratigraphy of the ivrea morainic amphitheatre (nw italy) ... ancient sandur (between san giusto, foglizzo and montanaro, at torrazza, between salussola and carisio). the oldest terraces are covered by several layers of aeolian silt (loess), deposited during subsequent glaciations, and each weathered to a soil. this loesspalaeosol sequence has a thickness of some metres and is visible in abandoned quarries that used to exploit the clayey silt for pottery production. the distal sector of the outwash plain was very affected by the pleistocene tectonic deformation involved in the uplift of the collina di torino and monferrato hills and in the north and northwestern migration of their external margin (de la pierre et al., 2003; giraudi, 2014), as recognized in the westernmost collina di torino area (forno & lucchesi, 2005). 4. historical background the long history of study of the ima can be well ordered by grouping its vast geological literature on the basis of the climate-stratigraphical model followed by the scholars. following diffusion of the glacial theory (agassiz, 1840), studer (1844) recognized the glacial nature of the serra d’ivrea. the ima and the rivoli-avigliana amphitheatres were the first end moraine system studied in italy (martins & gastaldi, 1850). in the surveys by gastaldi and bruno (bruno, 1877), synthesized in the 1:400,000 western alps map (franchi et al., 1908), the ima was regarded as an undifferentiated landform constructed during only a single glaciation (fig. 6a). the glacial deposits (deposito morenico) were distinguished from pliocene sediments, outwash sediments (diluvium) and postglacial fluvial sediments (alluvium). baretti (1877) and sacco (1888) also supported the single glaciation model. according to the drift theory of lyell (1833), bruno (1877) sustained a glacial-marine genesis of the amphitheatre when the sea still extended into the alpine piedmont sector. he based his opinion on the diffusion of outcrops of well stratified fine sediments containing both dropstones and marine mollusc fossils, interpreted as glaciomarine deposits (at sento and pian torinetto in fig. 6 the stratigraphic mapping of the ima according to different models on glaciations. (a) only one long glaciation model (second part of xix century). (b) four glaciations separated by long interglacials according to penck & brückner (1894-1980ss). (c) many glaciations separated by short interglacials (end of 20th century-present). (d) nine glaciations of the present work. 34 gianotti f. et al. the strambinello ls, into the rio borriana stream incision, at candia, mazzé and borgomasino in the vische ls). this hypothesis was sustained by stoppani (1880), but strongly denied by baretti (1877), sacco (1888) and marco (1892), who considered the fossils as reworked. subsequently, penck et al. (1894) and penck & brückner (1909) distinguished two alpine glaciations (y and z glaciations or riss and würm, respectively) of their classical stratigraphy and considered the serra d’ivrea to be the largest morainic ridge in the alps (fig. 6b). the model of numerous glaciations was used in the first edition of the “ivrea” sheet (franchi et al., 1912) and in the “biella” sheet (franchi & stella, 1933) of the geological map of italy (1:100 000 scale). the proximal moraines in the serra d'ivrea were mapped as würmian and the more distal moraines as pre-würmian. sacco (1927) distinguished three glaciations, tentatively correlated with penck & brückner’s mindel, riss, and würm glaciations, but with different limits with respect to the cross section of the serra d’ivrea proposed by penck. sacco (1927) considered the serra d'ivrea as a rissian moraine. the sacco subdivisions were followed in the second edition of the 1:100 000 sheet 43 “biella” (bortolami et al., 1966) and substantially confirmed in some synthesis publications (carraro & petrucci, 1969; carraro et al., 1975). the ima map in carraro et al. (1975), which distinguishes the glacigenic sequence by facies and climate-stratigraphical units, was the most detailed map of the ima until few years ago. the issue on the glaciomarine origin was renewed with bio-stratigraphical work (carraro et al., 1974, barbieri et al., 1974; cerchio, 1980) supporting the existence of the glaciomarine deposits in the strambinello ls, based on: lithofacies analogy with the glaciomarine deposits described in literature, evidence of stratigraphical continuity with the underlying marine sediments, in situ oligotypical fossil fauna content, nonexistence of reworking proved by micro-foraminifer assemblages that are completely different from those of the marine sediments from which they should come, palynological content with non-reworked tertiary elements attesting a pliocene age of the deposit. in contrast, basilici et al. (1998) excluded a glaciomarine environment for this unit, owing to the very different altitudinal distribution of its basal erosional surface and because they consider the paleontological content as reworked. a synthesis of this complex question is also reported by carraro (in martinetto, 1998). according to the multi-glaciation model derived from the marine and ice-core isotopic stratigraphies (emiliani, 1955; shackleton, 1967; shackleton & opdyke, 1973) and following the criticism from various authors (i.e., kukla, 1977; bowen, 1978; sibrava et al., 1986), the penck & brückner classical alpine climate-stratigraphy was gradually abandoned in italy and switzerland (schlüchter, 2004). the ima deposits were subsequently subdivided into three main allogroups (carraro et al., 1991; carraro, 1992), on the base of pedostratigraphy and morphology (fig. 6b). the outermost san michele-borgo group included the ancient very weathered sediments preserved in the outer areas of the left side of the ima. the intermediate serra d’ivrea group included most of lateral and frontal morainic ridges. the innermost bollengo-albiano group corresponded to relics of the more proximal morainic ridge (piccola serra and strambino-romanoperosa moraines), referred to the lgm. in the last decades the finding of interglacial/ interstadial markers (palaeosols and lacustrinepalustrine layers interbedded within the glacigenic deposits) allowed recognition of ten stratigraphical units referred to as many glaciations (fig. 6c; gianotti, 1993, 1996, 2007; baio & gianotti, 1996; gianotti et al., 2008; see the following sections for detail). geochronologic data obtained by palaeomagnetic (carraro et al., 1991), radiocarbon (schneider, 1978; arobba et al. 1997) and cosmogenic nuclide (gianotti et al., 2008) dating methods, and the biostratigraphic data consisting of a reduced set of pollinic spectra (schneider, 1978; arobba et al., 1997; gianotti & pini, 2011) are presented in section 7 and used to constrain an updated stratigraphic reconstruction (fig. 6d). 5. stratigraphy of the ima the onset of the alpine quaternary glaciation on the southern alpine forelands was established at the end of the early pleistocene (muttoni et al., 2003, 2007) with correspondence to global cooling of mis22. the record of the glaciations is discontinuous along the southern side of the alps and the ima represents the end moraine systems with consistent differentiation of several glacial units (fig. 7) that can be essentially linked to the different glacial stadials (from mis 22-20 to mis 2) of the global isotopic curve (lisieki & raymo, 2005). the oldest glacigenic succession originated at the end of the early pleistocene according to the reverse magnetization of glaciolacustrine deposits covered by subglacial till at mongrando (carraro et al., 1991). age and distribution of the innermost glacigenic succession is constrained to the lgm by radiocarbon and cosmogenic nuclide dating (schneider, 1978; arobba et al., 1997; gianotti et al., 2008). between these two outermost and innermost units, seven other glacigenic units have been distinguished (gianotti et al., 2008), which for the most part must be referred to the middle pleistocene glaciations. before 2007, about 80% of the ima was ascribed to two single sequences of glacigenic deposits of middle pleistocene age (san michele-borgo group, formerly mindel, and serra d’ivrea group, formerly riss), while only the remaining 20% was referred to the late pleistocene (the innermost bollengo-albiano group) (carraro, 1992) (fig. 6b). successively the san michele-borgo group was split into six alloformations (mongrando, bornasco, montino, zubiena, parogno, torrazzo) and the serra d’ivrea group into three alloformations (magnano, serra, piverone) (gianotti, 2003, 2005, 2007). in particular the innermost piverone alloformation was distinguished from the serra d’ivrea group and ascribed to the last glacial cycle (mis 4 or mis 2) of late pleistocene age (gianotti et al., 2008). so the ima area referred to the late pleistocene glaciation extended to more than half of the total extent of the morainic system (fig. 6c). in the present 35 stratigraphy of the ivrea morainic amphitheatre (nw italy) ... 36 gianotti f. et al. work the piverone unit is re-interpreted as the outermost, first subsynthem of the lgm succession (ivrea synthem) and so referred to the maximum glacial expansion of the glacier during the mis 2 glacial. this stratigraphical reconstruction was based essentially on two items: the presence of interglacial/ interstadial marker layers between the glacigenic sequences and the pedostratigraphical analysis. the used markers correspond to temperate-warm climate palustrine deposits or to evolved palaeosols, covered by subglacial or ice-marginal till. both types of buried layers indicate long intervals of temperate-warm climate with interstadial or interglacial conditions. they separate deposits linked to glacial expansions with considerable difference in age, ranging from a few tens of thousands of years to about a hundred thousand years, respectively. thus these layers correspond to discontinuity of range high enough to separate distinct synthems (see section 8). pedostratigraphy has also been utilized as a tool for stratigraphical subdivision. it must be said that, as detailed pedological studies were never performed in the ima, soil data are somewhat rough. vetusols on moraines are rarely visible in outcrop, are deeply eroded to various degrees and show at best only the remnants of a b-horizon. not-significant inceptisols are dominant on the morainic relief. however, the evaluation of the color of surficial soils and derived colluvium, by using the munsell soil colour chart, has led to the rough recognition of three pedogroups characterized by different maximum hue index color: an older pedogroup a with a 2.5yr hue, an intermediate pedogroup b with a 5yr hue and a younger pedogroup c with a 7.5yr hue (gianotti, 2007). the pedogroups a and b approximately coincide with the mindel/san michele-borgo group, while the pedogroup c comprises the riss/serra group and the würm/bollengo-albiano group units. this basic subdivision allowed separation of the oldest succession into two parts (in detail the zubiena from the parogno synthems). in addition, a different degree of weathering of the tills was crucial to distinguish the magnano from the serra synthems, two units of the same pedogroup c. the most recent ivrea synthem was further subdivided on morpho-stratigraphical basis into subsynthems, which correspond to the lgm and lateglacial stadials of the last glaciation. the term stadial is here referred to the classical alpine climatostratigraphy concerning the phases of the glacial retreat (reference in ivy-ochs and al., 2008). in principle, each synthem could be further split into subsynthems, each referred to different glacial readvance with hundred/a few thousand of years of age gap (each morainic circle being a subsynthem). however, only the latest synthem may retain a complete set of recessional moraines. a complete sequence of the until now recognized stratigraphical units is described below, using the synthem terminology according to the u.b.s.u. stratigraphy used into the new geologic map of italy at the 1:50,000 scale (salvador, 1994; carraro et al., 2012). 5.1. the mongrando synthem the oldest glacigenic deposits of the amphitheatre form the outermost moraines in the northeastern sector of the ima (unit 4 in fig. 7). they consist of a group of three juxtaposed moraines stretching in a w-e direction between donato (1 in fig. 8) and mongrando and delimited by the fluvial incisions of the ingagna and viona streams on the north and on the south respectively. thus the ingagna stream marks also the outer boundary of the ima in this sector (b in fig. 8). these moraines show an abrupt termination towards the east above the mongrando village, where they were cut off by erosion by the ingagna and viona streams (a in fig. 4). a past extension of this morainic circle can be hypothesized on geometric relations toward the se in a flat area (the biellese alluvial plain) where the elvocervo fluvial fan develops. a group of large boulders of eclogitic micascists in the elvo riverbed near the borriana village, resting on the lower pliocene marine sediments, are present. because of their size and position they can be interpreted as erratic blocks, so their presence support a former wider extent of the amphitheatre towards the plain of biella 1.8 km beyond its current boundary. most of the outcropping sediments are interpretable as subglacial melt-out till and lodgement till also forming the upper part of the morainic relief. the long lasting erosion has exhumed the pre-glacial substrate now forming the lower part of the morainic relief in its easternmost sector (mongrando), made up of deeply weathered pre-glacial fluvial sandy gravels linked to the local basins (palaeo-elvo). the ancient fluvial deposits rest on the basic granulites outcropping in the ingagna valley floor. southward, the widespread subglacial till in the viona riverbed represents the innermost outcropping deposits of this unit. it consist of a strongly overconsolidated matrix-supported diamicton ranging from a massive and fissile lodgment till to a poorly stratified melt-out till, often deformed into staked slices by glaciotectonism, unweathered and so with a homogeneous pale bluegrey color. near cascina balca, nw of bornasco, the subglacial till frequently includes macro-remains of trees (branches, small trunks, roots) yet to be studied. very thick vetusols are locally visible on the morainic crests, where sporadic limbs of marginal flow till are preserved. they are deeply weathered, reaching a red color with a hue of 2.5yr that corresponds to the most developed soil profile of the ima. starting with penck et al. (1894) all authors agreed to assign these external moraines to the oldest glaciation recognizable in the ima which, however, according to penck et al. (1894) and penck & brückner (1909) is the penultimate glaciation (y or riss). later, these mo___________________ fig. 7 geologic map of the ivrea morainic amphitheatre. pedostratigraphic groups are indicated and further subdivided into nine synthems attributed to different glaciations, based on the presence of interbedded interstadial or interglacial markers or by pedostratigraphy. serra synthem (mis 6 glacial) and ivrea synthem (mis 2) are further subdivided into subsynthems on morphological basis (updated from gianotti et al., 2008). 37 stratigraphy of the ivrea morainic amphitheatre (nw italy) ... raines were referred to the mindel glaciation by sacco (1927), gabert (1962), carraro & petrucci (1962), carraro et al. (1975) and in the first and second editions of the biella sheet of the geological map of italy (franchi & stella, 1933; bortolami et al., 1966, respectively). carraro et al. (1991) carried out a palaeomagnetic analysis of a glacigenic sequence composed by two glaciolacustrine bodies, referred to glacier advance and retreat phases respectively, separated by subglacial till (san michele-borgo unit) at the eastern edge of the mongrando moraine (rio tenerello). a reverse polarity was registered in the lower lacustrine succession (granero unit) and a normal polarity into the upper one (castello unit). this result allowed to assign the first evidence of glaciation in the ima to the lower pleistocene middle pleistocene boundary, actually placed at 780 ka bp following gibbard et al. (2005). later the name of san michele-borgo group was extended to include all the ima mindel moraines (carraro, 1992) and the glacial deposits of the donato-mongando moraines were renamed as mongrando alloformation (gianotti, 1993, 1995). 5.2. the bosa palaeosol in the nw sector of the ima weathered colluvial deposits crop out at the bottom of the t. viona incision at se of case bosa near the village of donato (c in fig. 8). the 2.5 m thick colluvial deposits correspond to matrix-supported, apparently massive, weakly gravelly siltysands, coming from the resedimentation of glacial deposits. this colluvial cover lies on a marginal flow till, visible at the base of the small outcrop, made of coarse gravel and silty sand and poorly clino-stratified (immerging n25/30, i.e. towards the external edge). at the top the colluvium is covered by a more than 2 m thick fluvial deposit forming the viona alluvial plain. in the riverbed a typical subglacial till frequently crops out, likely forming the basal layer of the described sequence. the colluvial deposits and the underlying marginal flow till are weathered by pedogenesis through their full thickness. this soil is cut off at the top and it is the remnant of a b-horizon, with clay illuviation, moderate pedogenic aggregates, large mn oxide mottles and thin discontinuous pseudogleys. the hue color index of the matrix does not exceed a 7.5 yr value. the few clasts are all deeply weathered. the weathered colluvial deposits are strongly overconsolidated, because they are much more cohesive and harder than you would expect from cementation by oxides linked to pedogenesis. the over-consolidation can instead be explained by the pressure of the glacier during a subsequent advance (postpedogenesis) past the present viona incision, but not so far off as to completely erode the soil. this condition allows using the soil as a stratigraphical marker separating the products of two distinct glaciations preserved north of t. viona incision. according to this reconstruction, the soil was formed in the colluvial cover of a marginal till forming a stadial moraine of the mongrando synthem (first glaciation). the pedogenesis proceeded particularly during the first subsequent interglacial. subsequently this soil was overridden and consolidated by the dora baltea glacier and probably buried by subglacial deposits during a later glaciation (bornasco), likely already during the middle pleistocene fig. 8 panoramic view of the north-eastern sector of the ima (from the bric paglie slope at 1200 m a.s.l.). the terraced high plain of donato (a) is part of the local pre-glacial units named altopiani villafranchiani. the ingagna stream incision (b) and the elvo river alluvial plain (d) mark the ima northeastern and eastern edges respectively. the donato-mongrando moraine (1) is the oldest of the ima; the bosa palaeosol into the viona stream incision (c) separates this moraine from the innermost bornasco unit (2a), that downstream forms the bornasco-vermogno moraine (2b). the low moraines of the montino synthem (3) are scarcely visible. the sala biellese (4a) and zubiena (4b) villages lie above the higher crests of the zubiena synthem. the moraines of the parogno (5), torrazzo (6), magnano (7) and serra (8) follow inward. in the internal depression the piccola serra moraine (9) just overlooks. 38 gianotti f. et al. as suggested by the presence of the glaciolacustrine deposits with normal magnetic polarity at mongrando (castello unit in carraro et al., 1991). the ice marginal position reached by this advance can be tentatively identified at least with the first moraine that lies downstream of the viona stream, corresponding to the small lateral moraine of bosa, which extends just beyond the incision. thus, the bosa moraine marks the maximum glacier extent during the bornasco glaciation (see 5.3) the involved soil can be defined as a palaeosol, referring to its recent alluvial cover, but mainly as an exhumed soil, since it derives from an ancient palaeosol whose sedimentary cover was removed. 5.3. bornasco synthem the bornasco synthem has a restricted distribution at the outer edge of the ne sector of the ima and includes the glacigenic deposits attributed to the second glaciation distinguished in the ima (unit 5 in fig. 7). these form a moraine group, which runs for about 15 km in length and less than 1 km in width, between the viona and olobbia streams, with the exception of the bosa moraine that is beyond the viona (see 5.2). to the north these moraines are surrounded by the mongrando moraines; to the south-east, between mongrando and cerrione villages the main bornasco-vermogno lateral moraine is itself the outermost preserved moraine, as the mongrando synthem deposits have been completely removed by fluvial erosion in the bessa area. the same bornasco-vermogno moraine is the only morphological remnant of a previous complex covering an area of over 10 km2, now forming a high fluvial terrace buried and surrounded by the impressive tailings of an ancient roman gold mine (the bessa aurifodinae; fig. 7). the gold placer was likely formed by poly-phased fluvial erosion (viona and olobbia streams) and re-sedimentation of the previous glacigenic deposits of the bornasco synthem. the previous existence of a till cover is documented by the presence of many erratic boulders in the bessa mine dumps. the bornasco synthem glacigenic deposits, up to 75 m thick (at fontanile near donato), rest on bedrock south of donato village or against the mongrando till north of the viona stream. in the bessa area they directly overlie the deeply weathered fluvial sandy gravel forming the pre-glacial substrate (lower pleistocene elvo and dora baltea alluvial fans). the upper surface of these moraines, trending from 660 m to 310 m a.s.l. in elevation, is deeply weathered as documented by strongly evolved vetusols with a 2.5yr hue, thick at least up to 2.5 m and with completely altered clasts. even in this case the soils are more or less strongly truncated. the bornasco synthem is characterized also by a high diffusion of very fine marginal glaciolacustrine deposits in its southeastern sector, particularly outcropping along the olobbia riverbed. they are sands and weakly gravelly silty-sands, well stratified but deformed by glaciotectonism (folds), of a typical yellow color for the middle sand layers (turbiditic supply) and pale-yellowish grey for the massive diamicton layers (corresponding to aquatic flow till or to gravitative flow sediments). some silty-sandy layers contain fragments of chlamys sp., modiolus sp. and internal and external molds of marine bivalves. the fossils belong to lower pliocene (zanclean) faunas typical of a marine sandy sedimentary environment, but they are broken and abraded and so they are clearly reworked (gianotti, 1993). the perfect stratification and lamination of these yellow sands persuaded sacco (1927a, 1927b) to consider them as upper pliocene deposits in facies maremmana i.e. transitional. they were likely only supplied by glacial erosion and re-sedimentation of the marine sandy substrate, as the texture and the fossil content suggest. at the basis of the succession a thin layer of lodgement till passing to a thicker subglacial melt-out till into the riale della valle stream waterbed is found. this till covers a palaeosol formed at the top of fluvial gravels forming the preglacial substrate. only at the top of the succession are marginal flow till and marginal glaciofluvial gravels preserved on the moraine crests, with thickness increasing upstream (nw of briengo). the external moraine parallel to the moraine on which the bornasco village lies is constituted at the top by deformation till, made of slices of diamicton corresponding to previous subglacial meltout till. the bornasco moraines were attributed to the same glaciation as the mongrando moraines, i.e. to the riss by penck & brückner (1909) and to the mindel by sacco (1927). the bornasco synthem, belonging to the san michele-borgo group (carraro, 1992), was distinguished in the bessa region on morpho-, litho-, and pedostratigraphic basis and referred to the lower part of the middle pleistocene (gianotti, 1993, 1996; baio and gianotti, 1996). the bornasco synthem can be separated from the outermost mongrando synthem by the bosa exhumed palaeosol and from the innermost montino synthem thanks to the interglacial peat layer of sorgente solfurea. furthermore, it is distinguished from the montino synthem by a higher degree of weathering: soils appear thicker on the bornasco moraines, which frequently reach 2.5yr hue color indices, while the montino moraines are characterized by the conservation of palaeosols with a 5yr hue (but see 5.5). 5.4. sorgente solfurea interglacial layer this unit separates the bornasco synthem from the overlying montino synthem and can be referred to an interglacial or interstadial phase. it is the most problematic unit of the ima sequence, as the position of this significant layer is identified not so much from outcropping sediments, but from a water spring, named the sorgente solfurea (sulphurous spring), well known in the biella and canavese region for its healing properties. the spring is accessed by a drinking fountain next to a restaurant at the outlet of a tributary incision of the t. olobbia. the water emerges at the contact between a not visible peat layer and an overlying fluvial-lacustrine complex formed by varicolored clayey sands, sands and gravels, cropping out between 350 and 370 m altitude. therefore the upper permeable alluvial formation represents the aquifer of the water spring, while the peat layer represents its basal acquiclude. the peats were intersected by a landslide scarp at 350 m a.s.l. into the incision flank, during an alluvial 39 stratigraphy of the ivrea morainic amphitheatre (nw italy) ... event in 1994, and many peat fragments were visible in the riverbed at that time. the peats rest on glaciolacustrine deposits of the bornasco synthem, outcropping up to a level of 345 m a.s.l. in the bottom of the small incision next to the restaurant and extensively along the bed of the t. olobbia. above the peat layer a 4-5 m thick lacustrine body of stratified clayey silts and silty sands crops out poorly. at the base, a layer of laminated clayey silts and silty sands containing numerous small vegetal macro remains is present. a sample from a clayey silt level had been subjected to palynological analysis (gianotti, 1993). the pollen association indicates a coniferous forest of relatively cold climate, while the thermophilous elements are scarce or ambiguous (e. martinetto, pers. comm.). cyperacea and filicales monolete may be in relation to a humid environment, but well drained according to the absence of concentrycistes (tab. 1). these fine sediments are covered by glaciofluvial sandy gravels with well-rounded pebbles, and with the degree of weathering increasing upwards. the scarcity of outcrops does not allow to verify the continuity of this succession, reaching 375 m of elevation. the gravels switch at the top to marginal flow till and this is buried by subglacial melt-out till of the montino synthem. 5.5. montino synthem the montino synthem includes the glacigenic deposits linked to the third glacial advance registered in the ima (unit 6 in fig. 7). it forms a 11 km long group of low lateral moraines aligned along the t. olobbia stream incision, but its extent is limited to a very thin band, of 200-300 m to 800 m near montino, limited to the left (eastern) ima sector: because most of the deposits were buried by the subsequent zubiena synthem glacigenic deposits, the montino synthem is the narrowest unit of the ima. the deep incision of the t. olobbia downstream montino village marks the boundary between the bornasco and montino synthems. the montino moraines were initially referred to the riss by penck & brückner (1909), to the mindel by sacco (1927) and later to the san michele-borgo group by carraro (1992). its glaciofluvial deposits, very widespread and thick in the southeastern sector (montino-la tana), together with the cerrione unit (fluvial pre-glacial substrate), may correspond to the diluvium of sacco (1888). this glaciofluvial facies was interpreted as the basal and external part of the zubiena synthem (gianotti, 1993). the montino synthem was finally differentiated by gianotti (2007) on the basis of a palaeosol at the top of the glaciofluvial sequence (cascina comunità palaeosol, see 5.6). the montino synthem is characterized by glacioaquatic deposits prevailing on the tills in the central sector, between montino and albare. on the right side of the olobbia valley and into its tributary incisions a 30 m thick sedimentary succession is visible in several wide outcrops: fluvial coarse gravels at the base, with wellrounded pebbles and cobbles; they are passing in continuity to a glaciolacustrine sequence. the coarsening upward sequence of the sandy gravel layers and the increase in the angularity of the clasts suggest the approach of the glacial front. but the presence of rhythmites in the middle-upper sequence indicates the persistence of a lake likely dammed by the glacier downstream. this aquatic succession is overlain by a boulder -rich deposit several meters thick, which corresponds to a marginal flow till. the weathering notably increases upward, passing from the unweathered basal gravels to deeply weathered clasts in the upper 10 m at the top of the succession. the depositional surface at the top is weathered into reddish soils, which reach 2.5yr hue color index only in the weathered colluvial deposits that cover the morainic flanks in the northern sector. in turn, the moraines lack such evolved soils, because they are strongly truncated by erosion. in the southeastern sector (right side of the lower olobbia valley) 2.5 m thick soils are frequent with a more than 1.5 m thick b-horizon with pedogenetic aggregates, hue 5 yr and deeply altered clasts. in the c-horizon the weathering front of the clasts reaches to almost 6-7 m in depth. these soils are much thicker and were preserved from erosion because they were buried by marginal tills of the subsequent glaciation (zubiena synthem). nevertheless further pedogenetic evolution was stopped by this burial, while a 2.5yr hue is frequently reached in soils of the overlying more internal and recent zubiena synthem. the montino synthem is separated from the outermost bornasco synthem by the sorgente solfurea interstadial peat layer and from the innermost zubiena synthem by the cascina comunità palaeosol (5.6). 5.6. cascina comunità palaeosol a palaeosol is present at the top of the montino synthem and separates it from the overlying zubiena synthem. north of cascina comunità (between mongrando and zubiena) two sequences of glaciolacustrine deposits crop out in the stream gully of a tributary of the t. olobbia. this stream likely derives from a previous spillway of a zubiena synthem frontal moraine. the lower unit (montino synthem) is deeply weathered, with at the top traces of pedogenetic aggregates into coarse sands with a reddish 5yr 4/4 color and into silty fine sands with a yellowish brown 7.5yr 5/8 color. in comparison, the upper glacigenic sediments are greyish because they are unweathered, producing a strong color contrast at the contact between the two units. this upper unit is interpretable as a lacustrine sequence during the glacier advance, as the deposits are deformed and covered by a 20 m thick glacial deposit (not outcropping) forming a tab. 1 list of pollen taxa detected only in one sample of the sorgente solfurea site, from a layer above the buried peat layer (outcrop in incision 50 m upstream of the restaurant la bessa, zubiena). fpa = 6423 grains/g (from gianotti, 1993). 40 gianotti f. et al. moraine referred to the zubiena synthem. about 350 m downstream (nnw of montino) the lower glaciolacustrine unit presents an 80 cm thick pedogenized diamicton at the top, corresponding to an aquatic flow till. the unit is very coherent, with traces of pedogenetic aggregates, abundant mn-oxide mottlling and a hue color of 5yr 5/8. also this soil is buried by a thin body of unweathered stratified gravelly sands and by colluvial products deriving from the re-sedimentation of the montino synthem weathered till during the subsequent glaciation. further to the south, at the southeastern edge of the montino and zubiena synthems near cascina cecco at 350 m a.s.l., another palaeosol crops out in the rio della valle sorda riverbed (a tributary stream of the olobbia stream). it separates two subglacial tills which are otherwise indistinguishable. the soil, developed at the top of subglacial deposits of the montino synthem, depicts a flat palaeo-surface exposed after glacier withdrawal. the soil was successively buried by subglacial melt-out till during the successive glaciation (zubiena synthem) and then finally exhumed. this stratigraphic reconstruction is supported by the plano-altimetric position of this succession and of their correlated ice-marginal landforms. 5.7. zubiena synthem the zubiena synthem, together with the other ancient units, is only clearly recognizable in the northeastern sector of the ima. it comprises glacigenic deposits referable to the fourth glaciation recognizable in the ima (unit 7 in fig. 7), well outcropping in the middle of the ima left sector (4 in fig. 8). they form an 11 km long and up to 1.4 km wide lateral morainic complex, the widest of the ancient units. it is externally bounded by the olobbia stream and internally by the valle sorda stream. the zubiena moraines were referred to the riss (penck & brückner, 1909), to the mindel (sacco, 1927) and finally grouped into the san michele-borgo group (carraro, 1992). the zubiena synthem was distinguished on a pedostratigraphic basis from the surrounding bornasco and parogno synthems (gianotti, 2003), and later (gianotti, 2007) also from the montino synthem. the basal contact which trends from 700 to 370 m a.s.l. is an erosional surface by which the zubiena synthem lies above the montino synthem and, only at the northwestern edge (south of donato), directly above the bornasco synthem. outcrops of subglacial and marginal tills prevail. the moraines, although deeply remodelled as their rounded crests show, appear very well expressed and with steep sides, having been only partially lowered by fluvial incision. the sala biellese (4a in fig. 8) and zubiena (4b in fig. 8) villages lie above the two moraine alignments. the depositional top of the succession is characterized by red soils, more or less deeply cut by erosion, reach a hue color of 2.5yr and with deeply weathered clasts. the zubiena synthem is part of the ima most ancient 2.5yr pedogroup a. the zubiena synthem is separated from the outermost montino synthem by the comunità palaeosol (5.6), while the distinction with the innermost parogno synthem (see 5.8) is exclusively pedostratigraphical, because the zubiena synthem belongs to the pedogroup a and the parogno synthem to the pedogroup b. 5.8. parogno synthem the parogno synthem was clearly identified only in the left lateral ima sector, while in the other sectors of the amphitheatre it could not be separated from the subsequent torrazzo synthem, as they show a similar degree of weathering. this unit groups the glacigenic deposits related to the fifth glaciation recognizable in the ima (unit 10 in fig. 7). it was distinguished from the zubiena synthem on the basis of pedostratigraphy by gianotti (2003) into a very limited sector eastwards of parogno. before, the parogno moraines were considered to be of riss (penck & brückner, 1909), mindel age (sacco, 1927) and were later assigned to the san michele-borgo group (carraro, 1992). four moraine alignments are recognizable, stretching 9 km long between the scalveis and parogno hamlets. this unit reaches its maximum width of 800 m and is roughly bounded by the riale della valle sorda and riale di parogno stream incisions. the moraines are not very different from those of the surrounding units: they are well formed, sometimes continuous, with very rounded crests. at the south-eastern edge the ridges end abruptly above the riale della valle sorda and riale di parogno streams confluence, because they are truncated by the intersection with the torrazzo synthem. the depositional top of the succession is characterized by yellowish red soils, weakly preserved, reaching a 5yr hue color into the b-horizon of decimetric thickness and with deeply weathered clasts. the parogno synthem is the first unit to return a clear and sustained color index lower than 2.5yr, typical of the outermost units. so it belongs to the intermediate 5 yr pedogroup b. the parogno synthem is differentiated from the outermost zubiena synthem owing to its less evolved soils (hue 5yr versus 2.5yr, respectively). it is separated from the innermost torrazzo synthem by the cascina gianetto interglacial palustrine layer (see 5.9). 5.9. cascina gianetto palustrine gyttja layer in the middle of the ima left lateral sector a layer of gyttja was found (marcuzzi, 2007; gianotti, 2007) in a deep stream incision between the village of parogno and cascina gianetto (fig. 9b). it separates two sequences of glacigenic deposits, both correlatable to marginal tills characterized by soil colors of hue 5yr. the 80 cm thick gyttja layer rests on subglacial deposits constituted by lodgement and deformation till (with staked slices of glaciolacustrine deposits, fig. 10d) referred to the parogno synthem, forming moraines in outermost position, and is covered by a succession of subglacial and marginal glacigenic sediments referable to the torrazzo synthem forming the overstanding moraines. the pollen content of this layer (gianotti & pini, 2011) suggests a correlation with the mis 11.3 and the mis 9.3 interglacial phases (see 7). 41 stratigraphy of the ivrea morainic amphitheatre (nw italy) ... 5.10. torrazzo synthem the torrazzo synthem can be recognized as a single unit only in the left lateral ima sector. this unit includes the glacigenic deposits related to the sixth glaciation (unit 11 in fig. 7). also this morainic complex is part of the san michele-borgo group (carraro, 1992), i.e. formerly riss (penck & brückner, 1909) or mindel (sacco, 1927). it was stratigraphically distinguished thanks to the finding of an organic rich layer in a stream incision south of parogno (gianetto interstadial layer, 5.9). the torrazzo synthem is morphologically characterized by the large number of moraines in the ima left sector, mainly in frontal position (6 in fig. 8). seven moraine alignments are recognizable, bounded by the rio di parogno riale della valle sorda incisions and stretching 11 km long between the torrazzo and cerrione villages with maximum width of 1.7 km ne of magnano. the outermost moraines, on which the torrazzo village lies, are straight lateral moraines. at santo sudario a wider frontal moraine complex developed, and this arrangement was maintained also by the innermost frontal moraines built during subsequent glaciations (magnano and serra): a small continuous, complete and wellpreserved morainic amphitheatre resulted thanks to a progressive shifting of the glacier margin towards the south (6 in fig. 4). east of santo sudario the torrazzo synthem ends because it is intersected and covered by the subsequent innermost magnano synthem glacigenic deposits. the depositional top of the succession is characterized by eroded yellowish red soils with a maximum hue color of 5yr and containing deeply weathered clasts. the torrazzo synthem can be separated from the outermost parogno synthem thanks to the occurrence of the gianetto interglacial palustrine layer (5.9). it can be distinguished from the innermost magnano synthem on pedostratigraphical basis as they belong to different pedogroups (hue 5yr versus 7.5yr, respectively). the outermost morainic complexes in the western (right) ima sectors, particularly in the chiusella valley and north of san giorgio canavese, are distinguished as 5yr pedogroup b, which comprises the undifferentiated torrazzo and parogno synthems. in the chiusella valley they form a notable morainic complex linked to a glacial lobe (villa riccardi ls) that passed over the watershed and came down to dam the chiusella valley foot. also in the frontal easternmost edge of the ima a small strip of glacial deposits, on which the salussola cemetery lies, is referable to the 5yr pedogroup owing to its higher degree of weathering and remodelling on respect to the innermost magnano frontal moraines. here a palaeosol outcrops, buried by 2 m thick fine sediments interpretable as the proglacial outwash deposits of the subsequent magnano phases. this soil shows pedogenetic aggregates, marked mn-oxides mottles and nodules and a 10yr 5/4 hue color with some mottles up to 7.5yr 5/8. 5.11. pré palaeosol southeastwards of scalveis a frontal complex built by a small lobe classified to the magnano synthem (see 6.12) surrounds a small depression hosting the ephemeral pré lake. in this sector the magnano moraines intersect the parogno moraines (fig. 7). the till forming the frontal arc buries a palaeosol at 685 m a.s.l. which formed at the top of the parogno glacigenic deposits. it shows moderate pedogenetic aggregates and a strong brown 7.5yr 5/6 hue color with wide dark reddish brown 2.5 yr 3/4 mottles. 5.12. magnano synthem the magnano synthem roughly corresponds to the outermost and ancient sector of the serra d’ivrea group (carraro, 1992). this unit includes the glacigenic deposits referable to the seventh glaciation (unit 14 in fig. 7). the magnano synthem is the first unit (in chronological order) to show a significant distribution and extent in all the ima sectors, with the exception of the southeastern frontal sector (between the dora baltea incision and cavaglià), where it is not preserved. moreover, the outermost border of the ima frontal sector is reached by the magnano moraines, which go up to 1.5 km (east of cavaglià) or several hundred meters (between bairo and cuceglio; at orio; at mazzé) beyond the position of 42 gianotti f. et al. fig. 9 photos of interglacial markers in the ima. (a) rio rudo palaeosol wellexposed in the right side of the rio rudo incision, separating the serra subglacial till (below) from the ivrea subglacial melt-out till (above). (b) glaciotectonized cascina gianetto gyttja layer separating the parogno subglacial till (below) from the torrazzo glacigenic sequence (above). (c) glaciofluvial gravel of the piverone subsynthem (lgm) resting above a weathered glaciofluvial gravel of the pedogroup b (torrazzo or parogno synthems) (abandoned quarry near mazzé). 43 stratigraphy of the ivrea morainic amphitheatre (nw italy) ... fig. 10 different facies of glacigenic deposits cropping out in the ima. (a) lodgement till of the internal serra subsynthem (palazzo). (b) submarginal melt-out till forming the m. bicocca frontal moraine, referred to the external serra subsynthem (mazzé). (c) proglacial glaciolacustrine bottomset deposits of the piverone subsynthem, made of parallel-laminated sandy silt (dora baltea r. left side, cascine francia, se of vische). (d) slices of proglacial glaciolacustrine clayey silt resulted from subglacial thrusting during the torrazzo glacial expansion (riale di parogno creek near cascina gianetto, magnano). (e-f) submarginal melt-out till forming the parella frontal moraine truncated by the chiusella r. incision (andrate subsynthem, south of parella). note the up-glacier dipping stratified sediments conforming to the inner slope of the moraine (e). the white box indicates the detail of the diamicton shown in f. the serra moraines. taking into account its glacial margin extent, the magnano synthem can justly represent the meg (most extensive glaciation) for the dora baltea basin. in the ima eastern sector this unit comprises four main moraine alignments (7 in fig 8), stretching for 25 km between castel rubino (andrate) and the cavaglià village. the 1.7 km maximum width is attained at its southeastern edge at cavaglià, but it extends also in the area of the san sudario ls north of zimone. a series of small lss defined by the outer moraine are to be highlighted, such as those encircling the lakes of pré and magnano (fig. 4). in the se sector of the ima more than half of the magnano and of the serra frontal moraines, built by the viverone glacial lobe, were destroyed by the synchronous outwash activity. this is certified by the sharp truncation of these two morainic groups between the cavaglià and santhià villages (b in fig. 4) and by the presence of a relict group of low moraines, outcropping 2.5 km downstream of the current boundary of the ima in the middle of the glaciofluvial external plain, on which the alice castello village lies (c in fig. 4). the isolated ridges of alice castello can be referred to the magnano synthem owing to their distal position (fig. 7). further to the sw, in the subsoil of the external outwash plain between the maglione and alice castello villages, a buried subglacial diamicton outcrops in a quarry documenting a previous, not be quantified, greater extension of the vische glacial lobe downstream beyond the quarry site (gariglio quarry; carraro, 1992, 2012). the magnano moraines were initially referred to the riss (penck & brückner, 1909; sacco, 1927; gabert, 1962). carraro (1992) first recognized in the serra d’ivrea group two pedounits of deposits with different weathering degrees, but cartographically undifferentiated. subsequently gianotti (2007) distinguished an outermost magnano alloformation from an innermost serra alloformation still on pedostratigraphical basis: despite both units having soils with the same maximum hue index (7.5yr), they show a marked difference in the preservation of weathered deposits on the surface, which are much more widespread on the magnano moraines, probably as a result of a greater soil thickness and evolution. a stark contrast in the weathering degree is evident in many places of the ima at the border between the two units, as at the football field of the orio village. the moraine ridges reach their maximum altitude of 800 m a.s.l. at the proximal edge of the unit near croce serra (andrate), and the minimum of 331 m a.s.l. with the crest of the quinto moraine (cavaglià). the depositional top of the succession is characterized by reddishyellow soils with maximum hue color of 7.5yr and moderately weathered clasts. the magnano synthem is differentiated from the outermost torrazzo synthem as they belong to different pedogroups based on index color (hue 7.5yr versus 5yr, respectively). moreover the moraines morphology is characterized by remarkable continuity, much better than the torrazzo moraines. the magnano synthem can be separated from the innermost serra synthem still on pedostratigraphical elements, but based on a higher weathering degree. the magnano moraines are well formed and rather continuous, morphologically not very different from the serra moraines, except for their lower elevation and the slightly higher degree of remodelling of the ridges. 5.13. serra synthem most of the ima, comprising the serra d’ivrea lateral moraines, are grouped into the serra synthem. this unit roughly corresponds to an intermediate sector of the serra d’ivrea group (carraro, 1992), from which the outermost magnano synthem and the innermost piverone subsynthem were separated (gianotti et al., 2008). it includes the glacigenic deposits related to the eighth glaciation recognizable in the ima. currently it is considered as a pre-lgm unit referred to the penultimate glaciation (mis 6). the serra synthem has been named after the serra d’ivrea, the biggest lateral moraine of the dora baltea basin. in detail, the serra d’ivrea is composed of seven to eight huge lateral moraines stretching 16 km along the internal side of the left sector of the ima. in every stretch two to three parallel moraine ridges are present together, with only one being the main moraine. this elevated crest gradually lowers downhill and every 1-2 km distance it leaves the role of main ridge to the next outermost moraine. the serra d’ivrea morainic complex was first referred to the last glaciation würm by penck (penck et al., 1894; penck & brückner, 1909) (fig. 3a) and in the first edition of the ivrea sheet of the geological map of italy (franchi et al., 1912). successively, gabert (1962) considered the würmian as only the internal part of the serra complex, and rissian its external part. the whole serra was instead referred to the penultimate glaciation (riss) by sacco (1927), in the second edition of the biella sheet of the geological map of italy (bortolami et al., 1966), by carraro & petrucci (1969) and carraro et al. (1975) (fig. 6c). carraro (1992), abandoning the penck & brückner terminology, established a serra d’ivrea group of middle pleistocene age. more recently the serra group was referred to the late pleistocene by arobba et al. (1997), according to the stratigraphy from the alice lake core (see 6.2). in contrast, gianotti et al. (2008) correlate the serra synthem to the penultimate glaciation (mis 6, end of the middle pleistocene) on the basis of the same alice core and according to the pre-lgm 10be exposure ages of erratic boulders from the outermost serra moraine. the boundary between the serra synthem and the outermost magnano synthem is the only one in the ima stratigraphy based solely on a different weathering degree, which, however, does not reflect in the soil color (hue 7.5yr), while a buried stratigraphical marker has not yet been found. the serra synthem is differentiated from the innermost ivrea synthem (mis 2 glaciation) according to the facies analysis of the alice superiore core sequence, that fixed the piverone subsynthem outer boundary (= lgm limit) as corresponding to the first moraine alignment located external to the drilling site (fig. 7). the serra synthem can be subdivided on morphostratigraphical basis into two subsynthems, here 44 gianotti f. et al. named external serra subsynthem and internal serra subsynthem, with the same boundary as that mapped by gabert (1962). this corresponds to a morphological change from an outer unit (external serra s.) with a partially discontinuous distribution (very similar to that of the magnano synthem) to an inner unit (internal serra s.) characterized by a high degree of continuity (similar to that of the younger piverone subsynthem) (fig. 7). together with the preliminary data from the analysis of the torre canavese core, presently in progress (see 6.1), a series of arguments in favour of an lgm age of the internal serra unit are expressed in the discussions (see 8). however, in the absence of robust evidence, a more cautious reconstruction is proposed, i.e. external and internal serra subsynthems both of mis 6 age, according to the previous state of knowledge about the amphitheatre stratigraphy. 5.13.1. external serra subsynthem the external serra subsynthem (unit 16 in fig. 7) contains the outermost high moraines of the serra d’ivrea complex. it has a wide but discontinuous extent, because it is repeatedly truncated by some of the big lobe moraine ridges (viverone ls at cavaglià, borgomasino sub-ls at villareggia and strambinello ls at baldissero) of the subsequent internal serra and piverone subsynthems. in the ima eastern sector this unit has a distribution very similar to that of the magnano synthem, made of two big straight lateral moraines, corresponding to the outermost ridges of the serra d’ivrea, which extends for 15 km between castel rubino (andrate) and the zimone village. some big erratics of eclogitic micaschist occur on the crest of the outermost of these moraines and two of them were sampled for cosmogenic 10be dating (gianotti et al., 2008). according to the new production rates for 10be (recalculated based on balco et al., 2009), the boulders have exposure ages of 30.8±3.5 ka (ivrea7) and 35.0±3.9 ka (ivrea8). the ages for these two boulders are minimum ages in light of the weathering of both the moraine itself and the boulder surfaces, suggesting a pre-lgm age for this moraine. downstream of zimone these moraines become arched in plan view as they forms a series of lobe morainic ridges continuing for another 9 km between zimone and cavaglià, including the zimone and the impressive salussola small ls (7 in fig. 4). here the morainic alignments multiply becoming four (zimone, salussola, dorzano) up to six (east of cavaglià). in the western sector the external serra subsynthem forms the intermediate ridges of the alice superiore and the strambinello lss developed in the chiusella valley, joined by a 3 km long lateral moraine east of lugnacco that forms the local watershed between chiusella and dora baltea basins. the unit has a particularly wide extent in the western sector between torre canavese and mazzé, where it reaches its maximum width and surrounds wide intermorainic depressions (vialfré peat bogs). from the culmination of these crests (madonna della rotonda ne of aglié at 490 m a.s.l., s. stefano near candia at 431 m, and monte bicocca north of mazzé at 344 m) are the popular panoramic views reported by martins and gastaldi (1850). in the mazzé gorge, where the dora baltea flows out of the amphitheatre, the 80 m upper succession forming the monte bicocca moraine is made of subglacial melt-out till constituted of fine sands very poor in clasts, from massive to locally laminated (fig. 10b), containing small blocks of fossil-bearing sandstone at the top. based on lithofacies and paleontological content these sediments were assigned to a pliocene glaciomarine environment by bruno (1877). on the contrary, they are derived essentially from the subglacial resedimentation in submarginal position of pliocene marine sands. in the ima southeastern frontal sector, the external serra synthem is only partially preserved and forms the outermost moraines, owing to the gradational processes (glaciofluvial erosion and sedimentation) linked to the following expansions. the top depositional surface reaches its maximum altitude of 860 m a.s.l. at the proximal edge of the unit near croce serra (andrate) in the eastern sector and of 788 m a.s.l. with the ripa meugliano crest, in the western sector. this unit is characterized by reddish-yellow soils with maximum hue color of 7.5yr and moderately weathered clasts. a strong brown color 7.5yr 5/8 is measured in the truncated thin b horizon or in its derived colluvial products, while the transitional c horizon is several meters thick and shows a typical yellowish brown 10yr 5/6 in the middle sands lenses and an olive yellow 2.5y 6/6 in the diamicton layers. 5.13.2. internal serra subsynthem the internal serra subsynthem (unit 18 in fig. 7) has a continuous extent along the whole amphitheatre, resulting in the most extensive unit of the ima. in the eastern sector this unit corresponds to the innermost ridges of the serra d’ivrea morainic complex, extending for 16 km between priat and zimone and strongly parallel to the lateral moraines of the external serra subsynthem. at priat (nw of andrate) the serra d’ivrea starts abruptly at 939 m a.s.l. (maximum ima elevation) in correspondence to the outlet of viona valley. here the moraine crest is suspended at a height of 680 m above the alluvial plain of the dora baltea river at san germano (260 m a.s.l.). in the first 3 km from andrate the internal serra moraines form the more elevated ridges of the serra d’ivrea complex. downstream of zimone the unit widens greatly, rising from 1 km wide up to 2.5 km at roppolo (the largest extent in the ima for a single unit), where six arched moraine alignments occur to form the left sector of the big viverone ls. the brosso-strambinello lateral moraine complex in the western sector is the equivalent of the serra d’ivrea in the eastern sector. however, in this side the moraines show a much less regular trend because they spread to form the internal ridges of the alice superiore and the strambinello lss developed in the chiusella valley. the ridge begins at 831 m a.s.l. close to the brosso village, therefore 100 m lower than the serra onset in the opposite sector, because the brosso moraine is 2.5 km further from the dora baltea valley outlet than the corresponding andrate moraine. south of the t. chiusella 45 stratigraphy of the ivrea morainic amphitheatre (nw italy) ... incision the unit becomes very large and surrounds the widest intermorainic depressions of the ima hosting the san giovanni dei boschi peat bog. in the frontal sector this unit branches into three main lobe complexes of viverone, settimo rottaro and vische (fig. 4), each with its own lateral and frontal moraines ensemble. these glacial lobe systems were already set up during the previous glaciation, but part of the older moraines were later erased by subsequent glaciofluvial outwash processes, especially in the villareggia-cigliano area and at cavaglià. the top depositional surface locally preserves reddish-yellow soils with maximum hue color of 7.5yr and fairly weathered clasts, apparently not markedly different from those of the external serra subsynthem (but see 5.15). 5.14. rio rudo palaeosol and other mis5 markers in contrast to the stratigraphic markers that separate the oldest glacigenic sequence, that all crop out in the outer northeastern sector of the ima, the interglacial layers that split the more recent succession come from the inner western sector. here an exposed palaeosol (gianotti, 2007) and an interstadial buried peat level (alice superiore unit) sampled through a core (arobba et al., 1997) divide the serra and ivrea synthems. a complex glacigenic succession is well exposed in the right side of the rudo stream deep incision, close to the san martino canavese village. a red weathered layer referable to a b-c soil horizon transition is present at the summit of a subglacial glacigenic sequence and is covered by another body of subglacial till (fig. 9a). locally a decimetric layer of silty sands rich in vegetable macro rests lies on the palaeosol and is covered by the subglacial till. the out of range dating of a wood fragment (> 50 ka 14c bp) indicates a pre-lgm age of this layer and of the lower glacigenic succession. the upper till may be correlated to the first outermost moraine that is referred to the piverone subsynthem. thus the rio rudo palaeosol is a stratigraphical marker separating the ivrea synthem from an older underlying unit that can be tentatively referred to the serra synthem. the palustrine level at 52 m of depth in the alice superiore core (see 6.2 and 7) and older than 43 ka 14c bp (arobba et al., 1997) is more problematic to date. comparing its pollen association with the data of azzano decimo core (pini et al., 2009) the alice superiore unit can be attributed to mis 7c or mis 5c (gianotti et al., 2008) (see 7). 5.15. ivrea synthem (mis 2) the ivrea synthem includes the glacigenic deposits of the last glaciation distributed in the entire dora baltea basin. they form the innermost morainic circles of the ima, referred to lgm, and constitute also the numerous and widespread features of the recessional sequence distributed in the mountain basin, referred to the lgm (29-19 ka bp) and lateglacial (19 ky-11.6 ka bp). the unit name was already used in the sheets of the geologic map of italy (dal piaz et al., 2010; carraro et al., 2012) to indicate the lgm to lateglacial sequence in the aosta valley. geochronological datings are not available for the outermost moraines of the ivrea synthem, but their age is constrained between the following dating: a maximum age is supplied by the 10be exposure ages on erratic blocks from the serra d’ivrea outermost ridge (see 5.13.1); minimum ages for the ima deglaciation are supplied by 10be exposure ages in the ivrea hills sector as discussed below (see 5.15.4 and section 7). on pedostratigraphic grounds the ivrea synthem is considered to be the most recent unit of the 7.5yr pedogroup. the deposits are scarcely weathered at the top into <1 m thin soils, with yellowish-brown 10yr 6/8 color and little to no altered clasts. also these soils are truncated, as proved by the diffusion of scattered thin bodies of soil-derived colluvial deposits with a yellow-reddish color (7.5yr 6/8, 5/6 and 5/3). a layer inversion in the colluvial products is typical, consisting in a yellowreddish 7.5yr colluvium covered by a yellowish 10yr colluvium layer. the presence of alignments of typical ice-marginal landforms (moraines and kame terraces) allowed recognition of five recessional stadials in the amphitheatre related to the lgm, and six recessional stadials in the dora baltea valley related to the lgm and lateglacial (gianotti et al., 2008). according to the new data, the ivrea synthem in the ima is divisible, on morphostratigraphical basis, into the following seven subsynthems: piverone (surrounding the viverone and candia lakes) corresponding to the lgm maximum expansion; palazzo (which delimits upstream the same lakes), andrate (forming the piccola serra-strambino-parella morainic circle) and finally the pavone, bienca, prà san pietro and germano subsynthems (resting on the ivrea hills), corresponding to the main recessional stadials still of lgm age. 5.15.1. piverone subsynthem (lgm glacial acme) the piverone subsynthem is the oldest unit forming the ivrea synthem and includes the glacigenic deposits referable to the maximum expansion of the dora baltea glacier during the climax of the last glaciation (lgm high glacial). this unit has a widespread and continuous distribution in the internal sector of the amphitheatre, quite similar to that of the outermost serra synthem. differently from the serra synthem made of big moraines, it is represented by low and discontinuous moraines and mainly by numerous kame terraces composed by glaciolacustrine (fig. 10c) and delta-fan marginal deposits. numerous villages (from east to west: piverone, viverone, azeglio, settimo rottaro, borgomasino, vische, mercenasco, scarmagno, san martino and strambinello) are located on the ridges of this large and low-relief unit. this unit was attributed to the würm or to the riss glaciation by the different authors, together with the internal serra subsynthem from which the piverone subsynthem was not differentiated. a piverone alloformation was first named and mapped by gianotti et al. (2008) who distinguished it from the serra d’ivrea group, corresponding to the b unit of the alice superiore core of arobba et al. (1987), but enlarging its external portion (see section 6.2 and fig. 14). the piverone alloformation was differentiated from 46 gianotti f. et al. the bollengo-albiano group (würm/lgm unit, renamed here as andrate subsynthem) on pedostratigraphical basis, because of a very different thickness of the transitional c horizon of soils. the piverone alloformation was so referred to the same würm/last glacial cycle of the ivrea unit, but hypothetically linked to the mis 4 stadial (gianotti et al., 2008). the difference in the soil profile has now been recognized to be due to morphological (intermorainic valley outlets) and hydrogeological (ground water flow) local conditions and so it should not have a clear chrono-stratigraphic meaning. all of the ivrea synthem sequence (starting from the piverone subsynthem) can be so most likely referred to the mis 2 stadial. 5.15.2. palazzo subsynthem (lgm stadial) clearly different from the piverone subsynthem in its distal sector, the palazzo subsynthem is represented by a group of moraines forming an innermost discontinuous arc, on which the palazzo, strambino, quagliuzzo and loranzé alto villages are located. these subsynthems worth being distinguished, as the piverone moraines surround the lake basins of viverone and candia downstream, while the palazzo moraines border the basins upstream. in the distal sector the palazzo subsynthem glacial deposits form the two relicts of a morainic arc, separated by the dora alluvial plain, on which the vestigné cemetery (left side) and the strambino village (right side) lie. these low ridges acted as obstacles to the following glacial re-advance during the andrate stadial. so the dora baltea glacier constructed another set of terminal moraines against them and the palazzo and andrate subsynthem tills are closely welded. 5.15.3. andrate subsynthem (lgm stadial) the andrate subsynthem consists of two lateral moraines (the piccola serra moraine on the left and the parella moraine on the right; figs. 10e-f) and a frontal moraine at strambino. this discontinuous morainic arc is also named the “small morainic amphitheatre” by the locals. it corresponds to the bollengo-albiano group (carraro, 1992), dated to the late pleistocene. previously these deposits have been considered as the maximum expansion of the würmian glaciation, from sacco (1927) up to carraro et al (1975). the lgm external boundary was later moved outwards 0.5-4 km in the lateral sectors and up to 13 km in the frontal sector, by considering the piverone subsynthem as the outermost unit of the last glacial cycle in the ima (gianotti et al., 2008). the glacial deposits rest on an abrasion surface moulded on bedrock (at the valley mouth and on the ivrea hills, figs. 3a-b), on the pliocene marine substrate (at the internal depression bottom) and laterally against the same marine sediments (into the chiusella incision, figs. 3c-d) and the glacigenic deposits of the palazzo subsynthem. the main morphologic element of this unit is the piccola serra, a 8.6 km long lateral moraine with a slightly curved shape in plan. it starts at the andrate cemetery at 850 m a.s.l. and ends abruptly at the bollengo castle at 316 m a.s.l. (martins & gastaldi, 1850; baretti, 1877). the villages of andrate and burolo are located on its crest, while the bollengo village lies at the foot of the moraine end. the continuation of the glacial deposits in the subsurface of the alluvial plain is unrevealed by the presence of a hydrogeological divide identified in the subsoil (adorno, 1989). in the frontal sector a well expressed frontal moraine is preserved, at 280 m a.s.l., on which the romano and perosa villages lie. it separates an external high outwash plain suspended at 260-248 m a.s.l. above an internal lower terraced outwash plain at 238 m a.s.l. with a peat bog (cascine di romano). in the western sector the morainic arc is represented by a less evident lateral moraine than the piccola serra, on which the parella village lies, that dams the alice lake depression. stratified fossil-bearing deposits with dropstones crop out in the southern internal slope of the strambinello ls and correspond to the pliocene glaciomarine deposits of bruno (1877) (see 4). they form limbs laterally leaned upon a palaeo-scarp moulded into the marine substrate, now exposed by the chiusella stream lateral erosion. they are so interpreted as marginal glaciolacustrine deposits of lgm age referred to the palazzo and andrate subsynthems, sedimented into marginal and icedammed lakes between the retreating glacier front and this scarp of marine deposits (gianotti, 2007). the pliocene fossil content (microand macrofauna and pollen) was supplied from the scarp to the lake environment by means of gravitative mass transport (debris fall and mud flow) passing to turbiditic currents. the very low transport rate, mostly into the lake, allowed good preservation of part of the fossils and the lack of reworking features. 5.15.4. pavone subsynthem and other lgm stadials of the ivrea hills the pavone subsynthem is represented by a notable frontal moraine, 600 m long and 4-5m high, standing alone on the bedrock of the ivrea hills between ivrea and pavone (a in fig. 11). together with two other lateral moraines on the right side (above the fiorano village, b in fig. 11) and on the left side (on the m. albagua sw of chiaverano, c in fig. 11), it forms a terminal morainic arc. the other records of glacier retreat (after pavone, the bienca, prà san pietro and germano allomembers in gianotti et al., 2008) are represented by small and discontinuous moraines also exposed on the ivrea hills. in the internal plain, glacial deposits are buried below lacustrine and alluvial sediments. consequently, the complete reconstruction of the ice margin is highly speculative here (fig. 11). three erratic boulders from the ivrea hills were sampled for cosmogenic nuclide dating (gianotti et al., 2008). we recalculated the 10be exposure ages based on recently determined production rates as described in section 7. ivrea6 is a granite erratic block, resting just south of the sirio lake on the summit of the monte brogliero rocky hill at 317 m a.s.l. from it we obtained the oldest age (23.8±1.7 ka), that records deposition at the dora baltea glacier margin, while its front was withdrawing from the pavone stadial to the subsequent bienca stadial position. ivrea1 is a similar granite erratic block, whose position on the summit of the ronchesse hill, east of the pistono lake, is just slightly more proxi 47 stratigraphy of the ivrea morainic amphitheatre (nw italy) ... mal than the prà san pietro stadial position. the exposure age of this block is 20.1±3.0 ka, and may relate to a phase of glacial retreat between the prà san pietro stadial and the germano stadial positions. the granite boulder ivrea3 is located on a roche moutonnée above nero lake, not far from the ivrea1 sample site and in a similar stratigraphic position. nevertheless, it has a much younger exposure age (15.4±1.2 ka) likely related to surface erosion of the boulder. on the basis of the form, extent, and distribution of glacial landforms and deposits, the following evolution is recognized (gianotti et al., 2008). a wide area of granulite roches moutonnées without till cover is present in the distal sector of ivrea hills between pavone and chiaverano. this suggests a rapid downwasting of a clean dora baltea glacier (very little surface or entrained debris) after the andrate and the following quintas stadial. only to the sw of ivrea does the pavone morainic arc indicate a brief glacier readvance. during the bienca stadial, a glacial lobe persisted on the left side of the glacier in a large depression of the northern sector of ivrea hills, where some concentric moraines and kames are present (forno et al., 2005b). an icedamned lake formed in the bienca hollow as the glacier retreated (prà san pietro stadial). similar sequences of moraines, kame terraces and lower lacustrine terraces recur in various depressions between the hills at different elevations, with the last one in the more proximal lago nero hollow (germano stadial) (forno et al., 2007). by the germano stadial, the dora baltea glacier had definitively left the ima. 5.15.5. lateglacial and holocene during the alpine lateglacial (19-11.6 ka bp) the dora baltea glacier was completely retired upstream of the ima, according to the 10be exposure ages from the ivrea hills erratics. the elements that allow recognition of the successive six halts (subsynthems corresponding to glacial stadials) of the glacier during the recessional phase into the dora baltea valley are (fig. 1; gianotti et al., 2008): a frontal moraine in torredaniele, 82 km from monte bianco (torredaniele stadial); a concentration of granitic erratic blocks in the valley floor near bard (bard stadial; carraro, 1992); alignments of kame terraces, 18 km long on the left side of the valley between roisan and chambave, connected with lateral-frontal relics of moraines 58 km from monte bianco (chambave stadial, only in part equivalent to the chambave stadial of novarese, 1915); a frontal arc dissected by the dora baltea river near saint pierre, 26 km from monte bianco (saint pierre stadial); a group of lateral moraines on the right of the valley floor at la villette and dolonne near courmayeur, at only 3 km from actual brenva glacier front (courmayeur stadial; porter & orombelli, 1982; carraro et al., 2012), and a terminal moraine in the ferret valley (planpincieux stadial; porter & orombelli, 1982). two exposure ages were obtained from the distinctive roche moutonnée of the lower dora baltea valley floor, near donnas village (gianotti et al., 2008). the ages 16.9±1.4 ka (ivrea10) and 16.2±1.0 ka (ivrea11) provide a minimum age for the retreat of the glacier between the torredaniele stadial and the bard stadial positions. also the sedimentary infilling history of the ima internal depression that began during the lgm stadials is as well poorly constrained. recently, geophysical surveys in and around the candia lake, located in the internal depression of the candia ls, were carried out (colombero et al., 2014). they consisted of an extensive waterborne continuous vertical electrical sounding (cves) and self potential (sp) data recorded on the lake surface, and three electrical resistivity tomographies (erts) on land near the lake shores. the geophysical data suggest that the proximal (northern) sector of a proglacial lake wider than the present candia lake was filled by an advancing fan-delta, directly fed from the glacier meltwaters, during the palazzo stadial (fig. 12). the basin was not completely filled because the fast glacigenic sedimentation stopped suddenly due to a more pronounced glacial retreat. the glacier withdrew fig. 11 reconstruction of the halts of the dora baltea glacier front during the lgm stadials in the ivrea hills area: pavone (pav), bienca (bie), prà san pietro (pra) and germano (ger) stadials. locations of samples (ivrea1, 3 and 6) for 10be exposure dating are indicated by red numbers and symbols. 1) starting point of the serra d’ivrea; 2) serra d’ivrea moraine; 3) starting point of the piccola serra at andrate 4) piccola serra moraine; 5) starting point of the right lateral moraine at brosso; 6) alice superiore ls and lake; 7) monte buono monadnock; 8) sirio lake; 9) pistono lake; 10) black lake; 11) dora baltea river (on dtm, courtesy of piedmont region). 48 gianotti f. et al. up to the front halt identified by the andrate subsynthem end moraines 5 km upstream. a much slower lacustrine sedimentation continued into the relict basin. a similar evolution can be proposed for the largest viverone lake, which occupies the internal depression of the viverone ls. only a few lacustrine basins survived to the glacigenic filling processes in the internal plain; here a lacustrine and palustrine sedimentation could continue during the lateglacial and holocene, as recognized by palynological studies. schneider (1978) first carried out palynologic analysis supported by radiocarbon dating in the ima. lateglacial and postglacial successions were analyzed in 9 cores from 7 sites of the western alpine piedmont area (trana in the rivoli-avigliana amphitheatre; torfsee in the ivrea hills and viverone and alice superiore mires in the ima; biandronno lake in the verbano amphitheatre). at torfsee at 250 m a.s.l., a 10 ha wide marsh at ne of the sirio lake on the ivrea hills, a 5 m long core was drilled into a lacustrine and palustrine succession spanning from the oldest dryas to the boreal. in the logge mire close to the southern shore of viverone lake a 13 m deep drilling crossed mostly holocene sediments (0-11.2 m) up to coarse deposits related to the oldest dryas, according to palynologic assemblages. in the alice superiore mire (570 m a.s.l.) three 5 m long cores were collected, all of them reaching the oldest dryas layers. wood and cyperaceae from one core (profil 4) yielded the following uncalibrated radiocarbon ages: 11.72±0.24 14c ka bp, 11.49±0.15 14c ka bp, 9.85±0.12 14c ka bp, 5.14±0.1 14c ka bp. another core (profile 5) provided the oldest radiocarbon age for the ima (14.2±1.5 14c ka bp) obtained on clayey gyttja at 380-390 cm depth. this age, now calibrated to 17,70416,806 cal bp, was so considered the minimal age for the ima deglaciation, before the availability of oldest ages from the cosmogenic nuclide dating (gianotti et al., 2008). in the uppermost sequence other ages (11.66±0.9 ka bp and 12.39±0.16 ka bp) were obtained. in the alice cores the lower palynologic unit is assigned by schneider (1978) to the oldest dryas and it is referred to a tundra environment with herbaceous species (artemisia, rumex and chenopodiaceae). during the bølling interstadial, shrublands with betula and herbs appeared, later developing into a denser pine woodland. the younger dryas experienced the reduction of forest cover and expansion of xerophytes (artemisia and chenopodiaceae). compared with the palynologic spectra from the northern alps and middle europe, the alice spectra has a high rate of juniper just in the oldest dryas, indicating a favourable climate during all the lateglacial, abundance of larix in the second half of the bølling and low values in the oldest dryas; the mixed oak spread during the allerød, and rapidly decreased in the younger dryas. on the ivrea hills, forno et al. (2007) presented stratigraphical data from a succession cored in the northern sector of the ivrea hills. the tomalino mire (381 m asl, chiaverano) was manually cored in order to describe the sedimentary succession therein deposited and sample it for palynological investigations. lacustrine palustrine sediments cored at this site testify to deposition taking place in a basin no longer fed by a glaciofluvial stream, but instead controlled by the local morphology. as suggested by the comparison with the pollen record of lago sirio (schneider, 1978), the oldest sediments retrieved can be as old as the second part of the lateglacial interstadial or the younger dryas. geomorfig. 12 geological cross-section of the candia lake area derived from geophysical surveys (from colombero et al., 2014, modified). the articulated shape of the deepest resistivity boundary suggests the presence of buried kame-moraines of submarginal till (1). the extent of fine glaciolacustrine deposits (2 and 3) both under the lake and the plain suggests the wider extent of a former lake. the current candia lake is the relict of a wider ice-dammed lake, not completely filled up by deltaic deposits coming from the retreating dora baltea glacier. the filling up of the lake suddenly slowed down owing to the complete retreat of the glacier (5a) and continued so far (5b) by a moderate colluvial and alluvial supply from the southern side of the basin (6). 49 stratigraphy of the ivrea morainic amphitheatre (nw italy) ... phological observations indicate that sedimentation started locally at least at the beginning of the lateglacial. 6. drilling cores in the pedogroup c succession in the western sector of the ima the most ancient units seem very reduced, not preserved or not recognizable. in contrast, the most recent units (7.5yr pedogroup c) reach in this sector their maximum size. here, long lithostratigraphical logs from two continuous drill cores are available. the 82 m deep alice superiore core was drilled in 1984 for water research, analyzed by arobba et al. (1997) and gianotti et al. (2008) and re-interpreted in the present paper. the 55 m deep torre canavese core was drilled for stratigraphical purpose in 2013 by the writers, within the progeo piemonte project (giardino et al., 2011), with the aim of investigating a possibly complete late pleistocene succession and to obtain elements for the dating of the serra synthem. a comparison between the torre canavese core (see 6.1) and the alice superiore core (see 6.2) highlights the similarity between the two sedimentary sequences, since in both cores two thick bodies of subglacial till are separated by a layer of interglacial/interstadial organicterrigenous aquatic sediments (lacustrine at torre, palustrine at alice). it should however be taken into account that the two cores have different locations, because the torre core was collected from the middle of the serra synthem moraines, while the alice core was drilled on the palazzo subsynthem kame terraces in a more internal position (fig. 4). 6.1. the torre canavese core a 55 m long core was drilled in 2013 into the sedimentary sequence of the serra unit south of cascina zucca between the torre canavese and silva villages (2 in fig. 4). the core was drilled into a small depression in the western lateral sector of the ima, where the serra unit reaches its maximum width. moreover, the elevation (410 m a.s.l.) and the isolated location of the site in the middle of the serra moraines prevented any glacigenic deposit supply during the subsequent piverone expansion, in order to ensure the persistence of a lake characterized by slow and continuous sedimentation. only part of the preliminary results of this work are outlined below and discussed in section 8. the drill crossed the entire local glacigenic succession until the pre-glacial substrate at 53 m depth. this substrate corresponds to lower pleistocene fluvial deposits, made of weathered clast-supported sandy gravels derived from the chiusella valley, a local catchment basin confined to the sesia-lanzo zone. two about 10 m thick lacustrine sequences were cored, each resting on a subglacial till body with a thickness of 12 and 20 m, respectively. the upper till body is been obviously attributed to the serra synthem (fig. 13). the top of the upper lacustrine sequence is holocenic according to two radiometric datings (2343±27 14c a bp at 2.60 m depth corresponding to 2460 to 2320 cal bp; 8466±35 14c cal a bp at 3.37 m depth corresponding to 9535 to 9440 cal bp). the top of the lower lacustrine succession has supplied an out-of-range date (> 45 14c ka bp at 29.30 m depth). a preliminary pollen analysis was carried out on 12 selected samples and a complete magnetic susceptibility and loi analysis was performed (cnr-idpa). pollen spectra so far available do not support the chronological frame provided by 14c ages. pollen stratigraphy, although based on a limited number of samples, seems to suggest a lateglacial age for the part of the sequence where 14c dating yielded holocene ages. further analyses are in progress, both concerning pollen stratigraphy and radiocarbon dating, to fix this problem. 6.2. the alice superiore core in 1984 a borehole for water research was drilled at 585 m in the internal depression of the alice superiore ls near the alice lake (1 in fig. 4). the coring crossed a very varied and complex sedimentary succession up to 82 m of depth but without reaching the bedrock. at a depth of 52 m, a 1-m-thick peat layer was encountered between two glacigenic sequences (fig. 14). each sequence consists of glaciofluvial and glaciolacustrine deposits and flow till and includes a diamicton body with a thickness of 12 and 13 m respectively, interpreted as lodgement till. detailed biostratigraphic data from the peat layer are presented in the following section 7. the peat layer has a radiocarbon age > 44.3 ka 14c bp and referred as post-eemian in agreement with fagus pollen content. it was so considered as a late pleistocene interstadial marker referable to the mis 5c, separating the serra group deposits from the bollengo-albiano group ones. the entire serra group was referred to the late pleistocene (arobba et al., 1997). a different stratigraphical and chronological reconstruction was later proposed using the same data (gianotti, 2007; gianotti et al., 2008). on the basis of a mis 5c age of the interstadial peat layer, two units were differentiated, the serra alloformation of middle pleistocene age and the fig. 13 lithological data and preliminary stratigraphical interpretation of the torre canavese log in the ivrea morainic end system (2 in fig. 5). radiocarbon ages were calibrated using oxcal v3.10. calibrated dates are with 95.4% probability. 50 gianotti f. et al. piverone alloformation of late pleistocene age. without considering the new insights from the torre canavese log, two stratigraphical reconstructions are proposed for the ima north-western sector assuming the two different chronological attributions of the alice superiore peat layer, correlated with the mis 5c interstadial (fig. 14) or to the mis 7c interstadial. based on facies analysis, each subglacial layer in the alice core is correlated to moraines located in more distal positions. these marginal forms are part of the alice superiore ls, forming a huge morainic arc that extended up to the local edge of amphitheatre into the chiusella valley 3 km wsw from the coring site. its main right lateral moraine (costa canapre moraine, reaching an elevation of 750 m) corresponds, on morphological grounds, to the serra d’ivrea moraine on the opposite side of the amphitheatre. 7. chronological constraint the chronology of ami is supported by a few, but significant, dates, obtained by palaeomagnetic, radiocarbon and cosmogenic nuclide dating methods. moreover, a series of chronologic constraints based on correlation of, still inadequate, biostratigraphic data are proposed. the beginning of the ima was referred (carraro et al., 1991) to the early pleistocene-middle pleistocene boundary on palaeomagnetic basis, according to both reverse and normal magnetization of two glaciolacustrine sequences resting below and above subglacial till at mongrando (see 5.1). actually, according to the mis chronology (lisiecki & raymo, 2005) this chronostratigraphic boundary falls within an interglacial (mis 19), so the oldest glacigenic unit of the ima (mongrando synthem) likely holds the products of two different glacial expansions. this implies that only an ancient part (more external or underlying) of this synthem should be referred to a glaciation that occurred at the end of the early pleistocene, probably correlable to the mis 20 or to the mis 22, and the question requires further investigation. in this perspective, the closest reference stratigraphy is provided by the bagaggera log core from the southalpine plain ne of milan (scardia et al., 2010). in the middle of the ima eastern sector the stratigraphy of the pedogroups b (hue 5yr) is chronologically constrained by the marker layer of cascina gianetto (see 5.9). this gyttja layer is embedded between the glacigenic sequences of the parogno and torrazzo synthems. a preliminary pollen analysis was carried out on four selected samples from the cascina gianetto outcrop, to test the presence and the degree of palynomorphs preservation in different litologies (gianotti & pini, 2011). pollen is abundant and well preserved. pollen spectra are dominated by abies, accompanied in the lowermost samples by corylus, deciduous quercus and ulmus (fig. 15). these compositions reflect the occurrence of dense fir-dominated forest at the regional scale under warm-temperate climatic conditions. a record of environmental and climate changes for the middle-late fig. 14 stratigraphical reconstruction of the ima northwestern sector (cross section trace b in fig. 14), based on the attribution of the alice peat layer to the mis 5c interstadial (from gianotti et al., 2008, mod.). according to this, the serra synthem (mis 6) must correspond to the lower 12 m thick subglacial till body. the upper 13 m thick subglacial till body has to include the the piverone and palazzo subsinthems (mis 2) and is correlatable with the slightly more external succession of moraines and kame terraces. the coarse gravels lying above the interstadial layer are referred to as anaglacial proglacial (45-49 m) and marginal deposits (30-45 m) of the piverone subsynthem. the similar coarse gravels lying at the top of the succession should be cataglacial proglacial (13-17 m) and stadial marginal deposits (0-13 m) of the palazzo subsynthem. in the detailed profile (b) only the subglacial tills are colored. the dotted lines indicate the basal surfaces of the lgm (blue line) and of the mis 6 (red line) glacigenic successions. 51 stratigraphy of the ivrea morainic amphitheatre (nw italy) ... pleistocene of northern italy has been obtained on the azzano decimo core, a 255 mlong succession of marine-transitionalcontinental deposits retrieved in the friulian plain (nw italy). a palynological record is available for the whole sequence, but at the moment only data from the uppermost 95 m (ca. 20 215 ka bp) have been published (pini et al., 2009). the pollen spectra from the gianetto site can be compared with the azzano decimo core record. due to the limited amount of data available from the gianetto section, biostratigraphic correlation is at the moment tentative, but some hypothesis can be proposed. among the late and middle pleistocene abies-dominated forest phases recorded in the azzano decimo core, two of them show major similarities with the gianetto data, as for the lack or extreme scarcity of fagus and carpinus betulus pollen grains and the occurrence of corylus and other thermophilous species. they are correlatable with the mis 11.3 and the mis 9.3 interglacial phases. a correlation of the gianetto layer with the mis 11.3 interglacial would fit well with the stratigraphical reconstruction proposed by gianotti (2007) and gianotti et al. (2008), as it is followed by four glacigenic units related to distinct glaciations (i.e. mis 10, mis 8, mis 6 and mis 2) (see fig. 17). a more detailed palaeobotanical analysis of this layer could allow a better evaluation of its palaeoclimatic meaning and provide further support to the ima climatostratigraphic subdivision. concerning the chronological setting of the innermost ima units, radiocarbon and 10be exposure ages and pollen spectra are available. a precise chronological attribution of the interstadial/ interglacial marker of the alice superiore core (6.2) is clearly the basis for the correlation of the ima youngest units (external and internal serra, piverone, andrate) to the mis stratigraphy. the alice palynological spectrum (fig. 16) was derived from a unique sample from the peaty clay layer at 52 m depth, with good preservation and high pollen concentrations (>111 000 grains/g). it indicates a moist and temperate forested environment (a.p. index 88,5%), characterized by the dominance of quercus (25%), alnus (17%), fagus (13%) and betula (6.2%) with smaller amounts of picea (2.9%), carpinus (2.5%), abies (4.5%), tilia t. cordata (1.7%), ulmus (0.57%), cupressaceae (0.57%) and salix (0.29%). herbaceous taxa (11.5%) are represented by poaceae (1.41%), artemisia (1.70%), ranuncolaceae (1.41%), filicales monolete (1.13%), sagittaria (0.85%), potamogeton (1.41%) and others (arobba et al., 1997). two possibilities are most probable for the age of the alice superiore layer, from comparison of the alice palynological association and the azzano decimo stratigraphy (pini et al., 2009): a mis 7c age or a mis 5c age (gianotti et al., 2008). during mis 7a-b-c, the azzano profile shows long phases with fagus-abies dominance. the alice spectrum is particularly similar to azzano in mis 7c, with fagus-abies-quercus associations. regarding the possible attribution to the mis 5c, the first part of the eemian in azzano is characterized by the absence of both fagus and abies. the second part of eemian shows abies and carpinus with subordinate fagus. during mis 5c, a short phase is similar to the alice spectrum, unless the presence of betula in the alice sediments is due to the different environment and altitude (azzano is near the adriatic sea at 20 m a.s.l., alice is close to the western alpine piedmont at 585 m). after mis 5a, quercus no longer dominates and forest associations as dense as those found at alice are missing after the dürnten phase (60 ka bp). in the dora baltea basin 13 rocky samples were collected from erratic blocks and roches moutonnées (nine samples in the ivrea amphitheatre and four samfig. 15 the lacustrine layer of cascina gianetto and its preliminary pollen data selected % curves (from gianotti & pini, 2011). fig. 16 -the alice superiore core palynological spectrum, derived from a unique sample from a peaty clayey layer at 52 m depth, with good preservation and high pollen concentrations (>111 000 grains/g) (redrawn from arobba et al., 1997). 52 gianotti f. et al. ples in the aosta valley) and dated using cosmogenic 10be (gianotti, 2007; gianotti et al., 2008). here, we recalculate the 10be surface exposure ages reported in gianotti et al. (2008) using the northeast north america production rate (spallation production rate of 3.88±0.19 10be atoms g-1 yr-1) and the time-dependent scaling model of lal/stone (cronus-earth online calculator; balco et al., 2008, 2009). recent work at the chironico landslide in the leventina valley, switzerland, where both exposure ages and radiocarbon dates are available, has shown that the northeastern north america production rate is well applicable at alpine sites (claude et al., 2014). for ease of further afield site comparison of 10be ages, we use the northeastern north america production rate rather than an alpine specific local production rate. work by several authors shows excellent consistency for 10be production rates from several widely spaced sites (summarized in heyman, 2014). three basic chronological constraints have been provided by this dating method. the 10be exposure ages from the erratic boulders ivrea7 (30.8±3.5 ka) and ivrea8 (35.0±3.9 ka) suggest a pre-lgm age for the external serra subsynthem (see 5.13.1). the 10be exposure ages from the various boulders on the ivrea hills indicate an lgm age for the innermost units belonging to the ivrea synthem (see 5.15.5). in particular, the 10be exposure age from boulder ivrea6 (23.8±1.7 ka) supplies the oldest age for last glacial deglaciation in the ima. this age is in excellent agreement with the exposure ages from erratics from the outermost lgm moraines at wangen (solothurn, switzerland) on the northern swiss alpine foreland. the data from wangen indicate that the initial moraine abandonment was underway by 22.6±2.1 ka based on 10be ages for four boulders (ivy-ochs et al., 2006, recalculated according to the new production rates for 10be). good correlation can be found also with the remanzacco subsynthem recessional moraines in the tagliamento amphiteatre in eastern italian alps, dated between 22 and 18.5 cal ka 14c (fontana et al., 2014). before the nuclide cosmogenic dating, the minimum ages for the ima deglaciation were supplied by uncalibrated radiocarbon dating on lateglacial peaty sediments in the alice superiore lake (14,200 ±150 14c a bp; schneider, 1978) and in villa lake, in the lower aosta valley (12,700±130 14c a bp; brugiapaglia, 2001). the first dating, now calibrated to 17,704-16,806 cal bp, is the oldest definite radiocarbon age obtained in the ima (see 5.15.5 for the climato-stratigraphical framework reconstruction). 8. proposed cronostratigraphic and climato-stratigraphic framework the current updated knowledge on the ima stratigraphy is based on the recognition of nine synthems ranging from the end of the early pleistocene to the late pleistocene. at present, a cautious approach would refer the oldest glacigenic successions to the end of the lower pleistocene (mongrando and possibly bornasco synthems) and to the middle pleistocene glaciations (from bornasco to magnano synthems), without a precise correlation with the mis stadials. the serra synthem can instead be referred to the last glaciation of middle pleistocene age (mis 6). the last ivrea synthem is certainly referred to the lgm at the end of upper pleistocene (mis 2). the nine synthems can be only tentatively correlated to the glacial stadial of the mis stratigraphy on the basis of their stratigraphical order and with the constraint of four main points: 1) the early pleistocene age of the first unit (mongrando synthem), demonstrated by the reverse magnetization of its buried glaciolacustrine sediments; 2) the cascina gianetto layer possibly correlated to mis 11c interstadial and separating parogno from torrazzo synthems (gianotti & pini, 2013); 3) the presence of three younger synthems (magnano, serra and ivrea) consequently referred to the last three glaciations (mis 8, mis 6 and mis 2); the lgm age of the innermost unit fig. 17 (a) geological cross-section of the ima lateral north-eastern sector, where all the stratigraphical units have been recognized. profile trace is shown in fig. 14 (trace a). interstadial or interglacial markers are indicated with asterisks: 1) bosa palaeosol; 2) sorgente solfurea peat layer; 3) comunità palaeosol; 4) gianetto gyttja layer. (b) the glacigenic sequence is tentatively related to the subsequent pleistocene glaciations. the correlation is made with the global isotopic curve from lisieki & raymo (2005), which is a synthesis of 57 benthic marine oxygen isotope records. 53 stratigraphy of the ivrea morainic amphitheatre (nw italy) ... (ivrea synthem) on the basis of radiocarbon and 10be exposure ages (gianotti et al., 2008). the stratigraphical reconstruction was based on the presence of interglacial/interstadial marker layers between the glacigenic sequences and on the distinction in pedogroups. concerning their range as a discontinuity, we consider that a palustrine layer made of gyttja or peat can be assigned to an interglacial or interstadial phase on the basis of its pollen content. thus it delimits two synthems that, in absence of a detailed palynological study, can be referred to different 100 ka glacial cycles (i.e. mis 10 and mis 12) or to different expansion within the same glacial cycle (i.e. mis 4 and mis 2 of the last glacial cycle). on the contrary, we consider an evolved palaeosol to have passed through at least one interglacial phase, thus it has to separate synthems of different 100 ka glacial cycles. on the basis of these assumption and on the chronological constraints, a tentative reconstruction can be proposed to better fit the glacigenic units extent to the different peaks of the mis stratigraphy (fig. 17). first of all, the intermediate pedogroup b comprises the parogno synthem, correlated to the mis 12, and the torrazzo synthem to the mis 10, as they are separated by the cascina gianetto layer related to the mis 11c interstadial. a weak global isotopic signal characterizes the mis 14 yield to a lack of glacigenic products in the alpine piedmont. on the contrary the mis 16 strong climatic signal (lisiecki & raymo, 2005) seems the best fit for the wide extent of the zubiena morainic complex. moreover the mis 18 shows two distinct peaks separated by a marked interstadial (lisiecki & raymo, 2005). these assumptions can be referred to the bornasco and the montino units as two distinct glacial advances correlated to the two peaks of the mis 18 and separated by the sorgente solfurea peat layer related to the interstadial in between. in this case bornasco (or the upper part of this unit) and montino would became two synthems of the same 100 ka glacial cycle, each correlable to mis 18. the oldest mongrando synthem comprises glacial deposits that are correlated to the glacial stages mis 22 or mis 20. the three glacigenic units (magnano, serra and ivrea synthems) forming the more recent 7.5yr pedogroup c can be correlated to mis 8, mis 6 and mis 2 glacial respectively. in detail, the recalculated 10be ages for boulders ivrea7 and ivrea8 from the outermost serra of ivrea crest support an mis 6 age for this unit, according to the sharp cold signal for this stadial in the isotopic curve (lisiecki & raymo, 2005). more detailed data are known about the last glaciation. the ivrea synthem age is best constrained to mis 2 by the somewhat older 10be ages from the serra d’ivrea boulders (gianotti et al., 2008), the pre-lgm age of the underlying peat layer from the alice superiore core (arobba et al., 1987), the lgm 10be exposure ages from the ivrea hills boulders (gianotti et al., 2008) and the early lateglacial radiocarbon ages from the alice superiore peaty bog (schneider, 1978). the outermost unit of the ivrea synthem, the piverone subsynthem, is to be considered the maximum expansion stadial of the lgm, followed by the sequence of lgm recessional stadials corresponding to the palazzo, andrate, and pavone subsynthems (and other less important units). the piverone subsynthem and the regrouped palazzoandrate subsynthems could form a complex similar to the maximalständ and hochständ of lgm end moraines observed in the austrian alps by van husen (1997) and to the two-fold lgm glacial advance in the eastern southern alps (monegato et al., 2007; rossato et al., 2013). nevertheless, new insights come from the recently drilled torre canavese core that crossed all the preserved glacigenic sequence in the right sector of the ima. the radiocarbon dating (ion beam laboratory, eth zürich) and the palynological analysis (cnr-idpa, in progress) are going to strongly revise the stratigraphy of the more recent part of the ima. in detail, the still now available radiocarbon dating in the torre canavese core results in a holocene age for the upper part of the lacustrine succession covering the serra subglacial till and in a pre-lgm age for the top of the lacustrine sequence below the till. these preliminary data indicate a likely lgm age for the serra till, but this should be supported by a high-resolution palynological analysis (in progress) and further dating of the lower part of the upper lacustrine sequence. combining these results with the prelgm 10be exposure ages of the erratics from the outermost serra moraines, the serra synthem should be subdivided into an external serra unit, correlated to the mis 6 glacial, and into an internal serra unit, referable to the mis 2 glacial and so corresponding to the lgm maximum expansion of the dora baltea glacier. many other elements suggest a lgm age for the internal serra unit: the notable thickness of the upper subglacial till body (13 m) in the alice superiore core best fits with the presence of more than one unit above the interstadial peat layer at 52 m depth: so besides piverone unit also a part of the serra synthem (internal serra unit) should constitute the upper glacigenic sequence if the peaty layer is referred to mis 5c (fig. 14). on the other hand, all the serra synthem rests above the peaty layer if this is referred to mis 7c interstadial. the piverone unit has the same distribution of the internal serra unit (fig. 7). the piverone unit deposits and morphology (kame terraces and low discontinuous moraines) are typical of a recessional/cataglacial succession: so it could correspond to a recessional phase following to an acme phase, i.e. the piverone unit in continuity with the internal serra unit. the internal serra and piverone proglacial outwash deposits sharply intersect the external serra (and magnano) moraines (fig. 7). the soils present over the internal serra, piverone and andrate moraines show a 10yr hue color and only their colluvium reaches a more evolved 7.5yr color. this feature requires further study. a palaeosol was found under a very thin glaciofluvial gravels cover at the top of the high proglacial plain south of villareggia (gianotti & comina, 2012). this situation is better explained with an lgm age of the gravels and consequently with an lgm age for the internal serra moraines upstream. 54 gianotti f. et al. the subglacial deformation of the glacigenic sequence cropping out in the rio rudo incision (see 5.14) seems better explained with an lgm glacier very expanded outwards, i.e. until the outer edge of the internal serra unit. if these working hypotheses will be confirmed, a wide extent of the glacier in the last glaciation should be indicated in the ima, much larger than considered before (fig. 6d). in the ima left lateral sector this new interpretation fits well with the stratigraphy proposed by gabert (1962). 9. conclusion an updated review of the geomorphology and stratigraphy of the ivrea morainic amphitheatre is reported. nine synthems attributed to the same number of major glaciations ranging from the end of the early pleistocene to the late pleistocene were recognized and mapped. the mongrando, bornasco, montino, zubiena, parogno, torrazzo, magnano, serra, piverone and ivrea synthems occur from the oldest to the more recent unit. the outermost mongrando synthem is referable to a lower pleistocene glaciation (mis 22 or 20) and the innermost ivrea synthem to mis 2 corresponding to the last glaciation (lgm). the more ancient and weathered sequence (2.5yr pedogroup a) can be differentiated into the mongrando, bornasco, montino and zubiena synthems. the intermediate 5yr pedogroup b comprises the parogno and torrazzo synthems. all this sequence coincides with the mindel moraines or with the san michele-borgo group. three glacial units (magnano, serra and ivrea synthems) are distinguished into the more recent and less weathered deposits (pedogroup c 7.5yr). magnano and serra synthems coincide with the previous riss moraines (or the serra d’ivrea group), while the last ivrea synthem corresponds to the würm or to the bollengo-albiano group. the mongrando and bornasco synthems are separated by the bosa palaeosol; the bornasco and montino synthems by the sorgente solfurea peaty layer; the montino and zubiena synthems by the cascina comunità palaeosol; the parogno and torrazzo synthems by the cascina gianetto gyttja layer; the serra and piverone by the peat layer in the alice superiore core. on the contrary, the distinction between zubiena and parogno synthems, between parogno and magnano synthems and between magnano and serra synthems is made on pedostratigraphical basis. detailed palynologic analysis will be necessary to better constrain the glacigenic sequences through the characterization of identified organic levels, which are used as stratigraphic markers (interglacial, interstadial or stadial), and their correlation to well-known biostratigraphical sequences. in detail, they are the sorgente solfurea peat layer, the cascina gianetto gyttja layer (tentatively referred to mis 11.3), the alice superiore core peat layer (mis 7c or mis 5c); the torre canavese lacustrine sequences (work in progress) and the rio rudo organic-rich layer. the ivrea synthem is constrained by exposure and radiocarbon ages into thirteen principal subsynthems referable to glacial stadials of lgm-lateglacial: seven stadials in amphitheatre (namely, the piverone acme stadial, the palazzo, andrate, pavone, bienca, prà san pietro, and germano stadials) and six stadials in the aosta valley (torredaniele and bard in the lower valley; châtillon, chambave/fenis and saint-pierre in the middle valley; courmayeur and planpincieux in the high valley). the exposure ages of 23.8±1.7 ka (ivrea6) and 20.1±3.0 ka (ivrea1) from two erratic boulders on the ivrea hills provide a minimum age for final retreat of the dora baltea glacier from the ivrea morainic amphitheatre. acknowledgements this paper was realized in the function of field-trip guide for the aiqua congress in turin in february 2426, 2015, held in honor of francesco carraro. we thank the organisers and the participants for their interest and support. the work was conducted within the project “proactive management of geological heritage in the piemonte region” (www.progeopiemonte.it/en ), cofounded by the university of turin and the compagnia di san paolo bank foundation “jcapc progetti di ateneo 2011” grant on line b1 "experimental sciences and technology" (project id: orto11y7hr, p.i. prof. marco giardino). the reviews provided by a. fontana and g. scardia greatly improved the work. references adorno g. (1989) idrogeologia ed idrogeochimica dell’anfiteatro morenico d’ivrea ad est della dora baltea. degree thesis, university of turin. agassiz l. (1840) études sur les glaciers. jent et gasmann, neuchatel. arobba d., calderoni g., caramiello r., carraro f., giardino m. & quagliolo p. (1997) palynological and radiometric evidence of a last glacial-interstadial from peat sediments in the ivrea morainic amphiteatre (nw-italy). geologia insubrica 2(2), 143-148. baio m., gianotti f. (1996) studio geologico e giacimentologico dell’area della “bessa” (biella, italia). geologia insubrica, 1(1-2), 29-48. balco g., briner j., finkel r.c., rayburn j.a., ridge j.c. schaefer j.m. (2009) regional beryllium-10 production rate calibration for northeastern north america. quaternary geochronology, 4, 93-107. balco g., stone j.o., lifton n.a., dunai t.j. (2008). a complete and easily accessible means of calculating surface exposure ages or erosion rates from be-10 and al-26 measurements. quaternary geochronology, 3, 174-195. barbieri f., carraro f., petrucci f. (1974) osservazioni micropaleontologiche e stratigrafiche sulla serie marina e glaciomarina della valchiusella (ivrea, prov. di torino). acta nat. ateneo parmense, 10(1), 5-14. baretti m. (1877) studi geologici sul gruppo del gran paradiso. atti. r. acc. lincei, 3(1), 122 pp., 7 tavv., roma. basilici g., martinetto e., pavia g., violanti d. (1998) paleoenviromental evolution in the pliocene marine 55 stratigraphy of the ivrea morainic amphitheatre (nw italy) ... coastal succession of val chiusella (ivrea, nw italy). boll. soc. paleont. it., 36(1-2), 23-52. biino g., compagnoni r. (1989) the canavese zone between the serra d’ivrea and the dora baltea river (western alps). eclogae geol. helv., 82, 413-427. bortolami g., carraro f., friz c., govi m., sacchi r. (1966) foglio 43 “biella” della carta geologica d’italia alla scala 1:100.000. ii ed., serv. geol. it., roma. bowen d.q. (1978) quaternary geology: a stratigraphic framework for multidisciplinary work. pergamon press, oxford, pp. 221. brugiapaglia e. (2001) le lac de villa : un site clé pour l’histoire de la végétation terdiglaciaire et holocène en vallée d’aoste (italie). revue valdôtaine hist. nat., 55, 55-72. bruno l. (1877) i terreni costituenti l’anfiteatro allo sbocco della dora baltea. tip. f.l. curbis, ivrea, 65 pp. caramiello r., carraro f., collo g., gianotti f., giardino m., martinetto e., perotto a., siniscalco c. (1996) revisione del significato dei depositi “villafranchiani” in piemonte. il quaternario, italian j. quat. sci., 9 (1), 187-194. carraro f. (1992) la zona pedemontana da ivrea ad arona. depositi quaternari. in: dal piaz g. v. (ed.), le alpi dal monte bianco al lago maggiore. soc. geol. it., guide geologiche regionali, 3(a), 186209, bema, milano. carraro f., ed. (1996) revisione del villafranchiano nell'area-tipo di villafranca d'asti. il quaternario, italian j. quat. sci., 9(1), 5-120. carraro f. (1998) the problem of the “pliocene glaciomarine deposits of val chiusella”: state of the art. in martinetto e. (ed), pliocene plants, environments and climate of north-western italy. guide to the field conference: 41-44. mottalciata, april 27-30th. dip. scienze della terra, univ. studi torino, 85 pp. carraro f., fontan d., gianotti f., pennacchioni g., ravello m., schiavo a., tartarotti p., venturini g., vuillermoz r. (2012) 89 courmayeur sheet, geologic map of italy at the 1:50,000 scale. ispra servizio geologico d’italia. carraro f., lanza r., perotto a., zanella e. (1991) l’evoluzione morfologica del biellese occidentale durante il pliestocene inferiore e medio, in relazione all’inizio della costruzione dell’anfiteatro morenico d’ivrea. boll. museo reg. sc. nat. torino, 9(1), 99117. carraro f., medioli f., petrucci f. (1974) significato della presenza di depositi glaciomarini nell’anfiteatro morenico d’ivrea riguardo al problema del limite plio -pleistocene. acc. naz. lincei, rend. cl. sfmn., serie 8, 56(3), 397-402, roma. carraro f., medioli f., petrucci f. (1975) geomorphological study of the morainic amphitheatre of ivrea, northwest italy. bull. r. soc. new zealand, 13, 89-93. wellington. carraro f., petrucci f. (1969) carte géologique de la plaine du piémont 1:400.000. viii congrés inqua, paris. cerchio e. (1980) studio palinologico dei depositi glaciomarini pliocenico-medi della val chiusella. degree thesis, university of torino, 113 pp. claude a., ivy-ochs s., kober f., antognini m., salcher b., kubik p.w. (2014) the chironico landslide (valle leventina, southern swiss alps): age and evolution. swiss journal of geosciences, 107(2/3), 273-291. colombero c., comina c., gianotti f., sambuelli l. (2014) waterborne and on-land electrical surveys to suggest the geological evolution of a glacial lake in nw italy. journal of applied geophysics, 105, 191 -202. compagnoni r., dal piaz g.v., hunziker j.c., gosso g., lombardo b., williams p.f. (1977) the sesialanzo zone, a slice of continental crust with alpine high pressure-low temperature assemblages in the western italian alps. rend. soc. it. min. petr., 33, 281-334. dal piaz g.v., baggio p., bertolo d., bistacchi a., carraro f., fontan d., gianotti f., martin s., monopoli b., pennacchioni g., polino r., schiavo a., tartarotti p., venturini g. (2010) 91 châtillon sheet, geologic map of italy at the 1:50,000 scale. ispra servizio geologico d’italia. dal piaz g.v., bistacchi a., massironi m. (2003) geological outline of the alps. episodes, 26(3), 175-180. de giusti f., dal piaz g.v., massironi m., schiavo a. (2004) carta geotettonica della valle d’aosta. memorie scienze geologiche, padova, 55, 129-149. dela pierre f., piana f., boano p., fioraso g., forno m.g., polino r., clari p. (2003a) 157 trino sheet, geologic map of italy at the 1:50,000 scale. apat, agenzia per la protezione dell'ambiente e per i servizi tecnici dipartimento difesa del suolo, roma. dela pierre f., piana f., fioraso g., boano p., bicchi e., forno m.g., violanti d., balestro g., clari p., d’atri a., de luca d., morelli m., ruffini r. (2003b) note illustrative della carta geologica d’italia alla scala 1:50,000, foglio 157 trino. apat, agenzia per la protezione dell’ambiente e per i servizi tecnici dipartimento difesa del suolo, roma, 147 pp. ehlers j., gibbard p.l. (eds.) (2004a) quaternary glaciations extent and chronology, part i: europe. developments in quaternary science, vol. 2a. elsevier, amsterdam. ehlers j., gibbard p.l. (eds.) (2004b) quaternary glaciations extent and chronology, part ii: north america. developments in quaternary science, vol. 2b. elsevier, amsterdam. ehlers j., gibbard p.l. (eds.) (2004c) quaternary glaciations extent and chronology, part iii: south america, asia, africa, australasia, antarctica. developments in quaternary science, vol. 2c. elsevier, amsterdam. elter g. (1987) carte géologique de la vallée d’aoste, échelle 1:100.000. centro di studio sui problemi dell’orogeno delle alpi occidentali, c.n.r. torino, selca firenze. emiliani c. (1955) pleistocene temperatures. journal of geology, 63, 538-578. fontana a., monegato g., devoto s., zavagno e., burla i., cucchi f. (2014) evolution of an alpine fluvioglacial system at the lgm decay: the cormor megafan (ne italy). geomorphology, 204, 136-153. 56 gianotti f. et al. forno m. g., gattiglio m., comina c., barbero d., bertini a., boano p., doglione a., irace a., gianotti f., martinetto e., mottura a., sala b. (in press) stratigraphic notes on the the type-area and castelnuovo don bosco villafranchian succession (asti reliefs, piedmont). alpine and mediterranean quaternary, 27 (1). forno m.g., gianotti f. (2005a) arrêt 1. serra d’ivrea et petite serra (andrate). arrêt 2. stratigraphie de la serra d’ivrea (chiaverano). in: p. deline, m. giardino, g. nicoud (eds), le quaternaire des vallées alpines. collection edytem, cahiers de géographie, 3, 137-143, chambéry. forno m.g., gianotti f., grosso f. (2005b) arrêt 3. les collines d’ivrea. affleurements rocheux à modelé glaciaire à l’intérieur de l’ami. in: p. deline, m. giardino, g. nicoud (eds), le quaternaire des vallées alpines. collection edytem, cahiers de géographie, 3, 144-146, chambéry. forno m.g., gianotti f., grosso f., pini r. (2007) stratigrafia della sequenza cataglaciale nei colli di ivrea e dati pollinici preliminari sui depositi lacustri di chiaverano (torino). il quaternario, italian journal of quaternary sciences, 20(2), 213-228. forno m.g., gianotti f., racca g. (2010) significato paleoclimatico dei rapporti tra il glacialismo principale e quello tributario nella bassa valle della dora baltea. il quaternario, italian journal of quaternary sciences 23(1), 105-124. forno m.g., lucchesi s. (2005) la successione fluviale terrazzata pleistocenica dei versanti occidentale e nordoccidentale della collina di torino. il quaternario it. journ. quatern. sc., 18(2), 123-134. franchi s., mattirolo s., novarese v., stella a., zaccagna d. (1908) carta geologica delle alpi occidentali alla scala 1:400 000. r. uff. geol. it., roma. franchi s., mattirolo s., novarese v., stella a. (1912) foglio 42 “ivrea” della carta geologica d’italia alla scala 1:100.000. i ed., r. uff. geol. it., roma. franchi s., stella a. (1933) foglio 43 “biella” della carta geologica d’italia alla scala 1:100.000. i ed., r. uff. geol. it., roma. gabert p. (1962) les plaines occidentales du po e leurs piedmonts (piémont, lombardie occidentale et centrale). etude morphologique. imp. louis-jean, gap, pp. 531. gianotti f. (1993) ricostruzione dell’evoluzione quaternaria del margine esterno del settore laterale sinistro dell’anfiteatro morenico d’ivrea. degree thesis, university of turin. gianotti f. (1996) bessa. paesaggio ed evoluzione delle grandi aurifodine biellesi. quaderni di natura biellese, pp. 83, eventi e progetti editore, vigliano biellese. gianotti f. (2007) stratigrafia dell'anfiteatro morenico di ivrea. ph.d thesis, university of turin, pp. 270. gianotti f. (2011) geological setting of the pleistocene placers and roman gold mines of the ivrea morainic amphitheatre (piedmont, nw italy). ext. abstracts convegno aiqua “il quaternario italiano. conoscenze e prospettive”, roma, 24-25 febbraio 2011, il quaternario, italian journal of quaternary sciences, 24(2), 183-185. gianotti f., comina c. (2012) inquadramento geologico e prime indagini geofisiche e stratigrafiche sul sito di borgo nuovo di dora, borgo franco medievale abbandonato presso villareggia (to). in: panero f. & pinto g., assetti territoriali e villaggi abbandonati (secoli xii-xiv), cisim, off. grafiche comun., bra, 309-320. gianotti f., forno m.g., ivy-ochs s., kubik p.w. (2008) new chronological and stratigraphical data on the ivrea amphitheatre (piedmont, nw italy). quaternary international, 190, 123-135. gianotti f., pini r. (2011) stratigraphical subdivision of the middle pleistocene glacigenic sequence of the ivrea amphitheatre (piedmont, nw italy). abstracts xviii inqua congress bern 2011, 21-27 july, quaternary international, 279-280. gibbard p.l., boreham s., cohen k.m., moscariello a. (2005). global chronostratigraphical correlation table for the last 2.7 million years. boreas, 34(1) (unpaginated). giraudi c. (2014) quaternary studies as a tool to validate seismic hazard potential of tectonic structures: the case of the monferrato thrust front (vercelli plain, nnw italy). alpine and mediterranean quaternary, 27(1), 5-28. heyman j. (2014) paleoglaciation of the tibetan plateau and surrounding mountains based on exposure ages and ela depression estimates. quaternary sciences review, 91, 30-41. ivy-ochs s., kerschner h., reuther a., maisch m., sailer r., schaefer j., kubik p.w., synal h.-a., schlüchter c. (2006) the timing of glacier advances in the northern european alps based on surface exposure dating with cosmogenic 10be, 26al, 36cl, and 21ne. geological society of america special paper 415, 43-60. ivy-ochs s., kerschner h., reuther a., preusser f., heine k., maisch m., kubik p.w., schlüchter c. (2008) chronology of the last glacial cycle in the european alps. jour. quat. sc., 23, 559-573. kukla g.j. (1977) pleistocene land-sea correlations. 1. europe. earth science review, 13, 307-374. lisiecki l.e., raymo m.e. (2005) a pliocenepleistocene stack of 57 globally distributed benthic d18o records. paleoceanography, 20, pa1003, doi:10.1029/2004pa001071 lyell c. (1833) principles of geology, being an attempt to explain the former changes of the earth’ s surface, by reference to causes now in operation. 3 voll., j. murray, london. marco c. (1892) studio geologico dell’anfiteatro morenico d’ivrea. tipografia garda, ivrea, 62 pp., 2 tt, prof. 1:25.000, roux, torino. marcuzzi a. (2007) ricostruzione dell'evoluzione geologica plio-quaternaria di parte del settore laterale sinistro dell'anfiteatro morenico d'ivrea. degree thesis, university of turin. martinetto e. (ed.) (1998) pliocene plants, environments and climate of north-western italy. guide to the field conference: 39-53. mottalciata, april 2730th. univ. studi torino, pp. 85. martins c., gastaldi b. (1850) essai sur les terrains superficiels de la vallée du pô, aux environs de tu 57 stratigraphy of the ivrea morainic amphitheatre (nw italy) ... ms. received: december 12, 2014 final text received: february 19, 2014 rin, comparés a ceux de la plaine suisse. bull. soc. gèol. france, ser. 2, 7, 554-605. monegato g., ravazzi c., donegana m., pini r., calderoni g., wick l. (2007) evidence of a two-fold glacial advance during the last glacial maximum in the tagliamento end moraine system (eastern alps). quaternary research 68, 284-302. muttoni g., carcano c., garzanti e., ghielmi m., piccin a., pini r., rogledi s., sciunnach d. (2003) onset of major pleistocene glaciations in the alps. geology 31(11), 989-992. muttoni g., ravazzi c., breda m., pini r., laj c., kissel c., mazaud a., garzanti e. (2007) magnetostratigraphic dating of an intensification of glacial activity in the southern italian alps during marine isotope stage 22. quaternary research, 67, 161-173. penck a. , bruckner e. (1909) die alpen im eiszeitalter. volume 3: 761-768. chr. herm. tauchnitz, leipzig. penck a., bruckner e., du pasquier (1894) le système glaciaire des alpes. guide congr. géol. int., zurich., bull. soc. sc. nat. neuchatel, 22, pp. 86, 17 ff.. estratto (1894): imprimerie de h. wolfrath & c., neuchatel. pini r., ravazzi c., donegana m. (2009) pollen stratigraphy, vegetation and climate history of the last 215 ka in the azzano decimo core (plain of friuli, north-eastern italy). quaternary science reviews, 28, 1268-1290. porter s. c., orombelli g. (1982) late-glacial ice advances in the westwrn italian alps. boreas, 11, 125140. rossato s., monegato g., mozzi p., cucato m., gaudioso b., miola a. (2013) late quaternary glaciations and connections to the piedmont plain in the prealpine environment: the middle and lower astico valley (ne italy). quaternary international, 288, 8-24. sacco f. (1888) i terreni terziari e quaternari del biellese. 16 pp., 1 geol. map 1:100.000, guadagnini e candellero, torino. sacco f. (1927a) schema geologico del biellese. il biellese, ivrea. sacco f. (1927b) il glacialismo nella valle d’aosta. 66 pp., 2 carte 1.100.000, min. ll. pp., uff. idrog. po. sacco f. (1938) il glacialismo piemontese. l’universo, 16, 217-231 and 337-352, firenze. salvador a. (ed.) (1994) international stratigraphic guide. a guide to stratigraphic classification, terminology and procedure (2nd ed.). international union of geological sciences, trondheim, norway, and the geological society of america, boulder, colorado, pp. 214. scardia g., donegana m., muttoni g., ravazzi c., vezzoli g. (2010) late matuyama climate-driven alluvial fan progradation at the alpine southern foothills. quaternary science review, 29, 832-846. schlüchter c. (2004) the swiss glacial record a schematic summary. in ehlers j. and gibbard p.l. (eds.), quaternary glaciations extent and chronology, part i: europe, 413-418. schneider r.e. (1978) pollenanalytische untersuchungen zur kenntnis der spät-und postglazialen vegetationsgeschischte am südrand der alpen zwischen turin und varese (italien). bot. jahrb. syst., 100(1), 26-109. shackleton n.j. (1967) oxygen isotope analyses and paleotemperatures re-assessed. nature, 215, 15-17. shackleton n.j., opdyke n.d. (1973) oxygen isotope and paleomagnetic stratigraphy of equatorial pacific cores v28-238: oxigen isotope temperatures and ice volumes on a 105 year 106 year scale. quaternary research, 3, 39-55. sibrava v., bowen d.q., richmond g.m. (eds.) (1986) quaternary glaciations in the northern hemisphere. quaternary science reviews, 5, 171-180. stoppani a. (1880) l’era neozoica. in negri g, stoppani a., mercalli g., geologia d’italia. vallardi, milano. studer (1844) lehrbuch der physikalischen geographie und geologie. vol. 1 , chur und leipzig, bern. van husen d. (1997) lgm and late-glacial fluctuations in the eastern alps. quaternary international 38/39, 109-118. venturini g. (1995) geology, geochemistry and geochronology of the inner central sesia zone (western alps, italy). mém. géol. lausanne, 25, pp.148. zienert a. (1970) das moränen-amphitheater von ivrea (dora baltea). heidelberger geogr. arb., 38, 141157. zingg a., handy m. r., hunziker j. c., schmid s. m. (1990) tectonometamorphic history of the ivrea zone and its relationship to the crustal evolution of the southern alps . tectonophysic, 182, 169-182. 58 gianotti f. et al. sess 1_160211.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 comparing marine geology and coastal geomorphology vertical tectonic data, a case study between acquedolci and patti (messina) valeria lo presti 1, maurizio gasparo morticelli 1, attilio sulli 1, fabrizio antonioli 2 & raimondo catalano 1. 1 dipartimento di geologia e geodesia, università di palermo. 2 enea casaccia, roma. corresponding author: v. lo presti <valeria.lopresti@unipa.it> abstract: lo presti v. et al., comparing marine geology and coastal geomorphology vertical tectonic data, a case study between acquedolci and patti (messina). (it issn 0394-3356, 2011) the study of new data on vertical movements show a complex geologic response in a restricted sector of coastal area between acquedolci and patti (north-eastern sicily). different surveys allowed to the recognition of morphological, biological and archaeological markers of paleo-sea level. the analysis of these markers and the absolute datings performed, allowed to reconstruct the history of vertical deformation of this sector but only the comparison among coastal geomorphological data and marine geological data of platform-scarp continental system associates, allowed to find the necessary keys words to explain the geologic complexity of this sector. riassunto: lo presti v. et al., dati di geomorfologia costiera e geologia marina a confronto nella valutazione di tassi verticali nel quaternario. il caso della sicilia nord-orientale nel settore fra acquedolci e patti (messina). (it issn 03943356, 2011) lo studio di nuovi dati sui movimenti verticali mostra una complessa risposta geologica in un settore ristretto della fascia costiera fra acquedolci e patti (sicilia nord-orientale). diverse campagne di indagine hanno portato al riconoscimento di indicatori morfologici, biologici e archeologici del paleo livello del mare. l’analisi di questi markers e le datazioni assolute eseguite, hanno permesso di costruire un quadro sulla storia della deformazione verticale di questo settore ma solamente il confronto fra i dati geomorfologici costieri e gli ambienti marini di piattaforma e scarpata continentale ad essi associati, ha permesso di trovare le chiavi di lettura necessarie a spiegare la complessità geologica di questo settore. key words: coastal geomorphology, tectonic uplift, north-eastern sicily. parole chiave: geomorfologia costiera, sollevamento tettonico, sicilia nord-orientale.  1. introduction the calabrian arc records one of the major quaternary vertical movement in the whole mediterranean region. data on vertical move ments calculated for the coastal area along the north-sicilian continental margin indicate that, from east to west, a strong variation of vertical rates of uplift are recognized during both middle-late pleistocene and holocene. vertical position of sea-level, related deposits and morphologies provide useful markers to estimate uplift rates (lambeck et al., 2004; ferranti et al., 2006, antonioli et al., 2009). in the northwest sicily coast the uplift rates estimated for the holocene are greater than those estimated at the same point from the last interglacial (lig, 125 ka) (antonioli et al., 2006). the measured uplift misured appear as the result of two different processes, due to a “continuous regional” component and an "episodic coseismic” component respectively (ferranti et al., 2007). this study, based on published (ferranti et al., 2010) and new data, deals with the vertical tectonic movements calculated in the sector between acquedolci and patti (sicily northern coast). we focus our attention on the eastern sector of the sicilian northern coast and particularly immediately to the west of the vulcanotindari fault system, where several evidences of vertical movements during the pleistoceneholocene have been recognized. in this active sector the tectonic lineaments show different trends (nicolich et al., 1982; nigro & sulli, 1995) both onland (monaco & tortorici, 2000; atzori et al., 1978) and offshore (gabbianelli et al., 1996; cuppari et al., 1999). the occurrence of both oblique and normal fault systems and the alternation of rocks with different competence, as the hercynian metamorphic basement, its meso-cenozoic carbonate and oligocene-miocene terrigenous cover and 38 40 39 pleistocene deltaic ore and gravels (carbone et al., 1998), determine a complex geomorphological setting. the morphological response to the active tectonics is very different onland and in the offshore areas, due to the occurrence in the submerged areas of preserved structures, which are obliterated, eroded or covered in the exposed areas, as well seismic reflection data reveal trends and mechanisms of the relative motion from land to sea, through the analysis of the recognized fault systems. on the other hand the outcropping biological and geomorphological markers provide to estimate tectonic uplift rates, which are not allowed in the marine areas. 2. data analysis in the coastal sector from acquedolci and patti geomorphologic survey provided new data on quaternary uplif rates. it induced us to divide this area, close to the capo d’orlando promontory, in two sector with different deformational response to the regional tectonics, as evidenced by the different distribution of the pleistocene marine terraces. between capo d’orlando and patti marine abrasion surface are infrequent as well the marine terrace deposits, which are difficult to agedate. on the contrary to the west of capo d’orlando the pleistocene marine terraces morphologies are well preserved. between acquedolci and capo d'orlando we recognized a well preserved set of four orders of marine terraces. the terrace located at about 40 m (rocca scodoni) presents a marine deposit; the inner margin, located at 45-50m, is constituted by a cliff with several lithodomus holes. here a shell of spondylus s.p. in physiologic position was found; the u/th analysis on shell provides (with large error bar) an mis 5 age (between 100 and 125 ka) (scicchitano et al., 2011; gasparo morticelli et al., 2010). for this sector we estimate the tectonic uplift rate between 0.36-0.5 mm/yr. to the east of patti several auhors calculated regional uplift rates between 0.62 and 0.67 mm/yr from the last interglacial (ferranti et al., 2006). a few kilometers east of rocca scodonì, archaeological markers occur (scicchitano et al., 2011) along the coastal sector est of capo d’orlando. here an ancient quarry of grinding wheels for oil has been found. they present subcircular holes in the materials coming from the upper oligocene-lower miocene stilo-capo d’orlando deposits (carbone et al., 1998). the tectonic uplift was evaluated as the difference between the observed local paleo-sea level position and the predicted sea-level curve for the same locality. the resulting uplift rates of 0.36 mm/ yr (scicchitano et al., 2011) suggests similar tectonic uplift rates of rocca scodoni but relative to the holocene. between capo d'orlando and capo calavà, we studied the brolo island, located in the central part of a small bay; it is a "lentil" of metamorphic rocks emerging above the 14-18 m deep seafloor, at 450 m from the coastline. a detailed geomorphological sub aerial and underwater survey was conducted, which led to discovery a fossils-bearing conglomerate, in protected trays at 3.5 m from sea level, and well preserved lithophaga holes at about 70 cm from sea level. radiocarbon analysis on a gastropod found in the marine conglomerate gave us an age of 4745 yr +/59 (4965 years +-70 cal bp). if we compare this data with the predicted local sea level curves (lambeck et al., 2011), we obtain an uplift rate about 1.5 mm/yr (lo presti et al., 2010), which is higher than that calculated for the last interglacial and for the holocene in the study of archaeological rest. westward of capo calavà a "suspended" alluvial fan outcrops in a cliff a few meters back to the coastline. at the base of the cliff, around 1.3 meters above sea level, we recognize the stratigraphic contact between the alluvial fan deposit and the paleo-beach. the alluvial fan is incised in the highest part by a little river that flows into the sea with a fall of around 12 meters of height. in the patti area, near mongiove promontory, lithodomus holes on metamorphic rocks can be observed between 2.2 and 3.5 meter above sea level. also not allowing the calculation of tectonic uplift rates, the presence of a suspended alluvial fan and the recovery of lithodomus holes constitute a further evidence of effects of vertical tectonic movements along the coastal areas. the analysis of marine geology data demonstrates that the active tectonics determines the morphological feature of the continental shelf-slope system (lo presti, 2010). multibeam data evidenced structures connected to different faults systems, such as the submarine canyons which incised the continental slope in the acquedolci to patti offshore. most of the canyons are the continuation of fluvial beds (“fiumare”), demonstrating the occurrence of sea-land tectonic lineaments. mainly in the capo calavà sector submarine canyons are characterized by v-shaped valleys, very incised gullies and steep flanks, testifying the role of active tectonics. marine geology data evidenced also tilted ne-ward submerged surfaces, indicating existing structural movements, interesting only restricted areas, a few kilometers wide. comparing marine geology and coastal geomorphology ... 40 ms. received: testo ricevuto il 3. conclusions geomorphological surveys, radiocarbon analysis and marine geology data in the northwestern sector of peloritani mountains and its offshore evidenced significant assessment about uplift rates in the quaternary. field data reveal from capo d’orlando towards the east a sharp increase of the tectonic uplift rates during the holocene, with respect to the values calculated from the last interglacial. very different uplift rates mainly in the holocene in very close areas: 0.36 mm/yr (scicchitano et al. 2011) and 1.5 mm/yr (lo presti et al. 2010) distant only about 10 kilometers, has evidenced the role of tectonic lineaments, acting as releasing features during the holocene. seismic reflection profiles support this assumption, showing the metamorphic basement strongly dissected by high-angle faults, which at place determines the occurrence of emergent rock bodies (e.g. the brolo island). more the morphobathymetric data show tilted surfaces, suggesting the occurrence of “restricted regions” in the coastal-marine sector with different geological behavior as response to prominent tectonic releasing bands, determining their horizontal and vertical movements. references antonioli f., kershaw s., renda p., rust d., belluomini g., radtke u. & silenzi s. (2006) altitude of the last interglacial highstand in sicily (italy) and its implications for tectonic. quaternary int., 145 –146, 3–18. antonioli f., ferranti l., fontana a., amorosi a., m., bondesan a, braitenberg c., dutton a., fontolan g., furlani s., lambeck k., mastronuzzi g., monaco, c., spada g. & stocchi p. (2009) a review of the holocene sea-level changes and tectonic movements along the italian coastline. quaternary int., 206, 102-133. atzori p., ghisetti f., pezzino a. & vezzani l. (1978) strutture ed evoluzione geodinamica recente dell'area peloritana (sicilia nord-orientale). boll. soc. geol. it., 97, pp.31-56. carbone s., lentini f. & vinci g. (1998) carta geologica del settore occidentale dei monti peloritani (sicilia nord-orientale). s.el.ca., firenze. cuppari a., colantoni p., gabbianelli g., morelli d. & alparone r. (1999) – assetto ed evoluzione morfostrutturale dell’area marina compresa tra il margine della sicilia settentrionale e le isole eolie (golfo di patti). atti ass. it. ocean. limnol., 13 (1), 137-149. ferranti l., antonioli f., anzidei m., monaco c. & stocchi p. (2010) the timescale and spatial extent of vertical tectonic motions in italy: insights from relative sea-level changes studies. journal of the virtual explorer, electronic edition, issn 1441-8142, 36, paper 30. ferranti l., monaco c., antonioli f., maschio l., kershaw s. & verrubbi v. (2007) the contribution of regional uplift and coseismic slip to the vertical crustal motion in the messina straits, southern italy: evidence from raised late holocene shorelines. journal of geophysical research, 112, b06401, doi: 10.1029/2006jb004473. ferranti l., antonioli f., amorosi a., dai prà g., mastronuzzi g., mauz b., monaco c., et al., (2006) elevation of the last interglacial highstand in italy: a benchmark of coastal tectonics. quat. int., 145–146, 30–54. gabbianelli g., tramontana m, colantoni p. & fanucci f. (1996) – lineamenti morfostrutturali e sismostratigrafici del golfo di patti (margine nord siciliano). f.m. faranda & p. povero (eds.), data report eocumm95, conisma, 443-453. gasparo morticelli m., lo presti v., antonioli f., monaco c., sulli a. & zuccarello a. (2010) spatial extent of vertical tectonic motions in northern sicily using holocene and last interglacial sea level markers: a case study between acquedolci e capo d’orlando. rend. online soc. geol. it., 2, 668-669. lambeck k., antonioli f., purcell a., silenzi s. (2004a), sea level change along the italian coast for the past 10,000 yrs. quat. science revue. 23, 15671598. lambeck k., antonioli f., anzidei m., ferranti l., leoni g., scicchitano g. & silenzi s. (2011) sea level change along italian coast during holocene and a proiection for the future. journal of quaternary international. in print. lo presti v., gasparo morticelli m., antonioli f., sulli a. & catalano r. (2010) the brolo island, a lentil in the “ocean”. rend. online soc. geol. it. 2, 672 -673. lo presti v. (2010) analisi morfologica ed oceanografica del margine continentale della sicilia nord-orientale. relazione fra la fascia costiera e il sistema piattaforma-scarpata. tesi di dottorato. nicolich r., cita m.b., fabbri a., fanucci f., torelli l. & wezel f.c. (1982) – bacini sedimentari: ricerche geofisiche e di geologia marina. p.f. oceanografia e fondi marini, s.p. risorse minerarie, c.n.r., roma. nigro f. & sulli a. (1995) – plio-pleistocene extensional tectonics in the western peloritani area and its offshore (northeastern sicily) – tectonophysics, 252, 295-305. monaco c. & tortorici l. (2000) active faulting in the calabrian arc and eastern sicily. j. geodyn. 29, 407– 424. scicchitano g., lo presti v., spampinato c. r., gasparo morticelli m., antonioli f., auriemma r., ferranti l. & monaco c. (2011) – millstones as indicators of relative seal level changes in northern sicily and southern calabria coastlines, italy. quaternary int., in press. v. lo presti et al. january 15, 2011 15 gennaio 2011 << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /none /binding /left /calgrayprofile (dot gain 20%) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /error /compatibilitylevel 1.4 /compressobjects /tags /compresspages true /convertimagestoindexed true /passthroughjpegimages true /createjobticket false /defaultrenderingintent /default /detectblends true /detectcurves 0.0000 /colorconversionstrategy /cmyk /dothumbnails false /embedallfonts true /embedopentype false /parseiccprofilesincomments true /embedjoboptions true /dscreportinglevel 0 /emitdscwarnings false /endpage -1 /imagememory 1048576 /lockdistillerparams false /maxsubsetpct 100 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/hrv (za stvaranje adobe pdf dokumenata najpogodnijih za visokokvalitetni ispis prije tiskanja koristite ove postavke. stvoreni pdf dokumenti mogu se otvoriti acrobat i adobe reader 5.0 i kasnijim verzijama.) /hun 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can be opened with acrobat and adobe reader 5.0 and later.) >> /namespace [ (adobe) (common) (1.0) ] /othernamespaces [ << /asreaderspreads false /cropimagestoframes true /errorcontrol /warnandcontinue /flattenerignorespreadoverrides false /includeguidesgrids false /includenonprinting false /includeslug false /namespace [ (adobe) (indesign) (4.0) ] /omitplacedbitmaps false /omitplacedeps false /omitplacedpdf false /simulateoverprint /legacy >> << /addbleedmarks false /addcolorbars false /addcropmarks false /addpageinfo false /addregmarks false /convertcolors /converttocmyk /destinationprofilename () /destinationprofileselector /documentcmyk /downsample16bitimages true /flattenerpreset << /presetselector /mediumresolution >> /formelements false /generatestructure false /includebookmarks false /includehyperlinks false /includeinteractive false /includelayers false /includeprofiles false /multimediahandling /useobjectsettings /namespace [ (adobe) (creativesuite) (2.0) ] /pdfxoutputintentprofileselector /documentcmyk /preserveediting true /untaggedcmykhandling /leaveuntagged /untaggedrgbhandling /usedocumentprofile /usedocumentbleed false >> ] >> setdistillerparams << /hwresolution [2400 2400] /pagesize [612.000 792.000] >> setpagedevice base the interaction of geological and anthropic processes shaping the urban growth of ferrara and the evolution of the surrounding plain marco stefani1 & marco zuppiroli2 1 dipartimento di scienze della terra, università degli studi di ferrara, ferrara, italy. 2 dipartimento di architettura, università degli studi di ferrara, ferrara, italy. corresponding author: m. stefani <stm@unife.it> abstract: stefani m. & zuppiroli m., the interaction of geological and anthropic processes shaping the urban growth of ferrara and the evolution of the surrounding plain. (it issn 0394-3356, 2010) the town of ferrara is placed at the junction of the alluvial plain of the po river, the innermost portion of the po river delta plain, and the alluvial plain fed by the reno river and other apennines-derived streams. the depositional evolution of the fluvial system largely affected the urban shape, but human intervention in turn modified the river dynamics, to eventually subjugate it into the present-day artificial state. ferrara is the only city of the emilia region not sharing roman or a pre-roman origin; the future urban region was nevertheless well populated during ancient times. during roman times major artificial intervention was performed on the natural river framework, through long canal digging and river embankment. after the fall of the roman empire, a major restructuring of the river drainage system took place, leading to the development of two new distributary channels. ferrara nucleated during the early middle ages (7th century), near the divergence point of these channels, as a byzantine fortified structure, built on a crevasse splay, part of the northern levee body of the main po channel of the time. the southern side of the fortified village, was about 240 m long, its area 35,000 squared metres. the proto-urban structure then grew in a linear way, on the levee crest, because the elevated site offered protection against flooding waters and provided comparatively firm and well drained ground. during the first half of the 11th century, the urbanised area on the northern levee broadly stretched over a distance of about 2300 m, with a width of often less than 100 m. also the southern levee of the po di ferrara was progressively built over, during the middle ages. at the beginning of the 12th century, the present-day po channel, flowing at the north of the town, was generated through a river reorganisation phase traditionally known as rotta di ficarolo. during the same century, the romanesque cathedral was founded, at the distal edge of the sedimentary levee complex. during the following centuries, the early growth way of the urban tissue through individual building cell implantation gave way to discrete episodes of town growth and district planning. land reclamation works made the expansion of the urban area toward interfluvial argillaceous depressions possible. at the ending of the 15th century, this northward expansion culminated into a large renaissance expansion (addizione erculea). during the following century, the water flow in the southern po delta channels was suddenly terminated by an ill-fated attempt to artificially force the reno river to reach the sea through the former po di primaro channel. the very low topographic gradients and the elevated sediment load transported by this apennines-derived river rapidly silted up the ancient po di ferrara channel, just at the west of the town. large marsh therefore developed in the areas surrounding the town. after a long period of stagnation, the urban growth restarted only during the 20th century, in ways utterly unaware of the geological and environmental constrains and thus exposed to significant level of environment hazards, such river floods and earthquakes. riassunto: stefani m. & zuppiroli m., l'interazione dinamica tra processi geologici e antropogenici nel controllo della crescita urbana di ferrara. (it issn 0394-3356, 2010) il lavoro interdisciplinare esamina le strette relazioni dinamiche che hanno legato lo sviluppo della città di ferrara all’evoluzione idrografica e deposizionale della pianura circostante. lo studio ha riguardato l’architettura stratigrafica del sottosuolo, la cartografia geologica di superficie, ed il dettagliato rilievo topografico ed architettonico del centro storico. la distribuzione dei corpi sedimentari e delle strutture geomorfologiche fluviali hanno controllato le forme della crescita urbana, ma l’azione antropica ha a sua volta fortemente influenzato l’evoluzione del reticolo idrografico, fino a renderlo totalmente artificiale. ferrara sorge alla giunzione fra la pianura a meandri del po, la parte più interna della piana deltizia padana e la pianura formata dagli apporti del reno e di altri fiumi di provenienza appenninica. tutti i sedimenti affioranti nella provincia di ferrara sono di età olocenica. le geometrie dei corpi sedimentari tardo-quaternari sono state influenzate dall’attività tettonica compressiva in atto in questa porzione dell’avanfossa appenninica. ferrara è l’unico capoluogo dell’emilia-romagna a non avere avuto un’origine antica. in età romana l’area era però sede di un diffuso insediamento agricolo. in questa età furono realizzati importanti interventi di ingegneria idraulica sul ramo deltizio principale del po e su suoi affluenti appenninici. la fine dell’impero fu seguita da una drammatica fase di riorganizzazione idrografica, indotta sia da un cambiamento climatico verso condizione più fredde e umide, sia dal venire meno dell'irregimentazione idraulica artificiale. questa fase di riorganizzazione idrografica generò i due nuovi canali distributori deltizi del po di volano e del po di primaro. questi canali divergevano proprio in corrispondenza del futuro nucleo dell'area urbana di ferrara. il convergere di percorsi fluviali e terrestri, al confine fra le aree di influenza longobarda e greca, fece scegliere come sede di un nucleo fortificato bizantino un ventaglio di rotta topograficamente elevato, parte dell’argine naturale sinistro del po. questo insediamento, costituito da circa due dozzine di case in legno, fornì il primo nucleo di aggregazione del centro urbano, che inizialmente si sviluppò in modo fortemente lineare, sulla cresta del corpo sabbioso-limoso di argine naturale. questa struttura sabbiosa forniva infatti terreni drenati relativamente al riparo dal ristagno delle acque di piena. durante il xi secolo, l’abitato aveva raggiunto una lunghezza di oltre due chilometri, ma presentava una larghezza media di soli cento metri. nel secolo successivo, l’abitato si espanse verso il margine esterno del corpo di argine naturale, al cui piede fu fondata, in età comunale, la cattedrale romanica. nello stesso secolo xii, a monte di ferrara, una serie di rotte fluviali, conosciute come “rotta di ficarolo” generò l’attuale alveo del po, passante a nord della città. in età basso-medievale, il tessuto urbano si espanse lentamente verso la depressione interalvea, conservando comunque una forma fortemente allungata. sotto la signoria estense, le modalità di espansione passarono da una graduale espansione “spontanea” del tessuto, per crescita di singole cellule abitative radicate nel substrato stratigrafico, alla pianificazione di significative addizioni urbane, precedute da importanti lavori di bonifica e protezione idraulica. nel corso del xiv secolo, la città fu circondata da una cortina continua di fortificazioni, ancora allungate lungo il corpo arginale. il tratto meridionale delle mura mostrava un andamento concavo assai peculiare, che seguiva da vicino la sponda fluviale del xiii secolo. nel corso del xiv e del xv secolo, la progressiva riduzione del flusso nei rami meridionali del po, permise una certa espansione urbana nell’area sabbiosa di alveo. questa espansione incorporò nell’abitato la precedente isola fluviale di san antonio. il quaternario italian journal of quaternary sciences 23(2bis), 2010 volume speciale 355-372 356 m. stefani & m. zuppiroli 1. introduction the geological framework always exerts a strong influence on the shape of towns. if this control shows up in hill-sited cities, as it for example in siena, its influence is less easy to perceive, but not lesser in importance, in alluvial plain towns. this paper illustrates an example of such an influence through the analysis of the alluvial plain urban nucleus of ferrara. the contribution tries to unravel the complex interplay of the urban growth process with the late quaternary river evolution of this south-eastern portion of the po plain (castiglioni, 1999; castiglionii & pellegrini, 2001), belonging to the apennines foreland basin (pieri & groppi, 1981; castellarin et al., 1996; toscani et al., 2008). to achieve an interdisciplinary understanding of this interplay, subsurface and outcropping stratigraphy data were integrated with geomorphological and micro-relief study, archaeological data, architectural surveying, and ancient mapping and written historic information analysis. 1.1. the importance of geology in controlling the urban morphology the stratigraphic architecture and geomorphic framework of an alluvial plain affects the urban growth in many ways. the presence of a permeable sand substratum or of an impermeable muddy unit strongly influences the agriculture practise, the region viability, and the building techniques; less than one metre in elevation difference may largely change the river flooding frequency and severity. in areas involved into active hydrographic and sedimentary evolution, the depositional history and the urban growth often interact very closely, as recorded by the ravenna and venice histories. this relationship was particularly strong during the urban growth of ferrara, which did not simply “ice” a pre-existing topography, but dynamically interacted with the evolution of the po river channels (bondesan et al., 1995). natural factors largely shaped the town structures, but human action in turn impacted on the fluvial dynamics, at a growing pace, to eventually subjugate it into the present-day artificial state. 1.2. the regional geology framework of the ferrara area regional physical correlation, 14c dating, archaeological information, and historiography data suggest that the outcropping sediments in the ferrara province (figs. 1, 4) are entirely of holocene age, often dating back to only a few centuries ago. in the urban area, some sediments are even younger than the city buildings. the town is placed at the triple junction (figs. 2c, 3a) between the po river alluvial plain, the innermost portion of the po delta, and the lower alluvial plain of the reno river and of other apennines-derived streams. this innermost portion of the po river delta adjacent to ferrara is marked by a splay of divergent distributary channel bodies, but its evolution was totally dominated by riverine processes. marine and brackish facies are lacking in the whole of the upper pleistocene and holocene formation of the ferrara area. the urban area therefore shares more sedimentary and geomorphic feature with the fluvial plains than with the lower delta lobes, prograding into sea. the geometry of the outcropping sedimentary units is well known, whereas the reconstruction of the three dimension depositional architecture is only locally fathomed in some detail, because of the lack of subsurface information. it is clear, though, that the late quaternary depositional units show strong lateral variations in stratigraphic thickness and facies architecture (regione emilia romagna & eni, 1998; molinari et al., 2007), recording different subsidence rates (fig. 4a, b). subsidence variation is documented also by the deformation of the present-day topographic surface (bondesan et al., 1997). the subsidence gradients are induced by both the different compaction potential of the stratigraphic successions and the tectonic deformation of the apennines foreland-basin (pieri & groppi, 1981; bigi et al., 1990; amorosi et al., 2004; galadini, 2004; amorosi, 2008). beneath the study area, the overthrust front of the apennines chain is associated with the growth of a large ramp fold (casaglia anticline; pieri & groppi, 1981; montone & mariucci, 1999). the active structural regime induced several historic earthquakes, such as the 1570 one (guidoboni, 1984; postpischl, 1985; boschi et al., 1997). thermal fluid leaking from the fractured anticline reservoir affects the composition of near surface waters (see paragraph 3.5.2). the anticline area acted as the northern boundary for the apennines-derived sediments and as a repulsion area for the po river flow (fig. 2c). the spontaneous divagation of the fluvial channels was therefore not only induced by the natural aggradation of the fluvial bodies, but it was also influenced by the lateral gradient of subsidence and by palaeoclimatic modification. nel corso del xv secolo, le modalità di gestione del territorio di pianura mutarono più fortemente, con l’imposizione di grandi progetti territoriali geometrici, ormai distanti dalla strutturazione naturale della pianura. grandi opere di bonifica idraulica per gravità permisero alla città di colonizzare ampie depressioni interalvee, più che raddoppiando la superficie circondata dalle mura. questa espansione (addizione erculea) avvenne in gran parte su sedimenti argillosi e argilloso-torbosi, ormai lontani dai corpi di canale fluviale. negli anni immediatamente successivi al 1522, i rami meridionali del po furono definitivamente abbandonati, a causa di un infelice tentativo di immissione in essi del fiume reno. l’elevato apporto di sedimenti appenninici ed i bassi gradienti topografici condussero infatti rapidamente all’interrimento deposizionale degli alvei. la città fu quindi nuovamente circondata da ampie aree paludose. nel 1570, la città fu colpita da un forte terremoto, i cui effetti locali furono modulati dalle caratteristiche sedimentologico-stratigrafiche del substrato. dopo un lungo intervallo di stagnazione socio-economica, di contrazione demografica e di diradamento edilizio, nella seconda metà del xx secolo, l’organismo urbano riprese ad espandersi, ignorando però le preesistenze storiche e naturali, con modalità che lo espongono ad elevati rischi da terremoto, alluvione fluviale ed inquinamento delle acque di falda. keywords: stratigraphy, geomorphology, geography, holocene, river processes, urban history, po plain. parole chiave: stratigrafia, geomorfologia, geografia, olocene, processi fluviali, storia urbana, pianura padana. 2. methodology 2.1. subsurface geology in these difficult socio-economic times, the lack of financial support prevents new subsurface data from being acquired. to support the three dimension reconstruction of the stratigraphic bodies, hundreds of technical drillings, penetration tests, and water wells data were therefore collected. many subsurface data were provided by the ufficio geologico, sismico e dei suoli della regione emilia romagna and by the ferrara municipality administration. the data were never previously analysed for scientific purposes. the majority of these tests reached a depth of less than 40 m. the spatial density of information is largely variable, because of the data clustering in industrial or recently developed areas, leaving the historic centre and the agricultural zones poorly tested. for the interpretation of near-surface sediments and of buried anthropic structures, an observation of trenches excavated during infrastructure and maintenance works was carried on through the last 25 years. shallow drills, less than 8 m in depth, were performed in gardens and yards, particularly in the historic centre area of the town of ferrara. 2.2. surface geological mapping the making of a large scale geological cartography provided a major source of information on the study area (fig. 2c). the map drawing integrates surface surveying, sediment sampling, and shallow core drilling. pedological information was also considered. after the examination of the previous geomorphological map of the ferrara region (bondesan, 1975), the new mapping effort was carried out through the integration of several remote sensing information sources, from the spot satellite image to the landsat infrared data. aerial photographs deriving from recent and historic flights, like italy 2000, volo italia cgr, the ii world war u.s.a.a.f. and r.a.f. air-reconnaissance photos, and a 1911 airship survey. 2.3. topographic survey micro-relief information is especially valuable for the understanding of the city centre, since the ancient morphology is there preserved by the growth of the historic town (fig. 5). the previously available topographic representation (carta tecnica regionale 1/10,000; mappe catastali) were largely inaccurate, particularly so for the elevation data. a new survey was therefore performed through the entire historic town and adjacent areas. previously acquired (surveying by paolo russo and alberto pellegrinelli), but unpublished, point elevation data were integrated with new topographic measurements and manually interpolated to produce a digital elevation model, with a centimetre order of accuracy. the model was bench marked to the national geodetic framework. in the areas urbanised during the 20th century, the anthropogenic alteration was more severe; even rural zones recently experienced major morphological modification. for analysing the areas surrounding the historic town, a lower resolution elevation model was therefore deemed sufficient. this digital model was developed through the critical interpolation of the elevation data available from the carta tecnica regionale at the 1/10,000 scale, integrated with field controls. 2.4. ancient cartography and historic documentation the geomorphologic interpretation was largely helped by the examination of ancient written information and cartographic representations, predating the modern pervasive morphological alteration. a major contribution was provided by the geocoding of historic cartography, such as the early italian 1/25,000 scale mapping, the 1814 watercolour map (pezzoli & venturi, 1987), and 18th century large scale land-register maps (consorzio di bonifica i circondario polesine di ferrara & consorzio di bonifica ii circondario polesine di san giorgio, 2005). valuable information on the ancient geomorphology framework and the town evolution derived from graphic and written information on the historic sewer system, as in the 1728 map (fig. 3c). older cartographic representational of the 17th, 16th, and 15th centuries and ancient written information can also be located on a present-day cartography, as it is the case for the 1494 land-register manuscript (bocchi, 1976). 2.5. architecture survey and urban tissue analysis an extensive survey of the entire building tissue of the historic town is being carried on. by now, the ground floor plan of the majority of the medieval town has been drawn (example in fig. 6). maps from the land-register archives were also digitised and incorporated into the gis project. façades were continuously measured along entire roads (fig. 6) and the isometric representation of many building was achieved. this architectural data bank is relevant to this contribution, because of the close genetic linkage of the growth phases of the town, the urban tissue structure, the moistening and degradation state of walls, the underlying geomorphic and stratigraphic structures, and the depositional evolution of the area (fig. 6). 3. fluvial evolution, sedimentary history, and urban growth phases 3.1. from the late pleistocene braided rivers to proto-historical meandering channels during phases of the last glaciation (alpine würmian), associated with an eustatic lowstand, the study region was the site of widespread braided-river sedimentation, at more than 250 km from the seashore of the time (more than 18,000 yr bp). the late pleistocene sands (lower portion of fig. 3a) are well developed in the urban area subsurface (bondesan et al., 1974), where they form the first semi-confined aquifer (regione emilia romagna & eni, 1998; molinari et al., 2007). the depth to the sand top varies from 35-40 m, in the depocentres (stefani et al., 2003; stefani & vincenzi, 2005; stefani & cibin, 2010), to 10 m, on anticline culminations (casaglia, at the north-western border of town). beneath the urban area, the surface rapidly rises northward, from 32 to 13 m. the spatial gradient of the sand body depth controlled its interaction potential with later sedimentary processes. during early deglaciation, 357 358 fig. 1 geographic framework of the research area and place name localisation. the study ferrara town developed in the lower alluvial plain of the po river, which now flows a few kilometres to the north of the urban centre. the historic town is still surrounded by fortified renaissance walls, limiting the area described by the digital elevation model, visible in fig. 2c and 3b. localizzazione geografica dell'area di studio e dei toponimi citati nel testo. ferrara è posta nella bassa pianura padana, pochi chilometri a sud dell'attuale corso del po. il centro storico è ancora quasi interamente circondato da mura, che limitano l'area descitta dal modello digitale del terreno visibile in fig. 2c e 3b. 359the interaction of geological and anthropic processes ... fig. 2 location of the areas illustrated in this figure (a). roman times meander structures of the po river fed by the reworking of pleistocene sands (b). geological map of the ferrara area (c). the town developed at the triple junction between the meander fluvial plain of the po river, the lower alluvial plain of the reno and other apennines sourced rivers, and the innermost portion of the po delta region, dominated by riverine deposits. red stars locate the main finding of roman time sites; the digital elevation model is visible in the historic centre area. localizzazione delle aree illustrate in figure (a). corpi sabbiosi depostesi in meandri di età romana e derivanti in buona parte dal rimaneggiamento di sabbie pleistoceniche singlaciali (b). carta geologica di dettaglio dell'area di ferrara. la città si enucleò durante l'alto medioevo sul corpo arginale sinistro del po, nella regione di contatto fra la pianura a meandri di questo fiume, la bassa pianura alluvionale formata dal reno e da altri fiumi appenninici, e la parte più interna della pianura deltizia del po, dominata da processi fluviali. le stelle rosse indicano i principali rinvenimenti di siti archeologici di età romana. all'area del centro storico si sovrappone il modello altimetrico semplificato. 360 m. stefani & m. zuppiroli the change in the fluvial regime, the genesis of preand intra-alpine lakes, and the return to a biostasis regime induced a sharp reduction in the fluvial sedimentary load. this reduction produced alluvial fan incision and interruption of the sedimentary accumulation, through large portions of the po river and venetian plains (fontana et al., 2004; stefani & vincenzi, 2005). in the investigated region, the top of the pleistocene is therefore marked by an erosive, discordance surface. the post-glacial sea-level rise triggered renewed alluvial plain sedimentation. the first, discontinuous sediments consist of silt deposits, infilling shallow incisions. complex alluvial plain deposition followed, through holocene times. the depositional style of the po river was strongly influenced by the nature of the local substratum. at the starting of the renewed accumulation, the pleistocene sands were largely outcropping and thus easily reworked by the meandering river flow. point-bar systems therefore largely derived from the cannibalistic reworking of the local pleistocene sand substratum. the extension of the meandering belt then shrunk, because in the lagoon flooding the northern side of the roman time main delta lobe (eridanum), the port town of comacchio was growing of the spreading out of lower alluvial plain, fine-grained deposits, protecting the upper pleistocene sands from erosion. during late transgressive and highstand times, this sedimentary trend confined the meander development to the less subsiding areas, where the pleistocene sand remained exposed to reworking. the maximum flooding phase, dating at about 5500 yr b.p. (correggiari et al., 2005; stefani & vincenzi, 2005), is difficult to precisely detect at this inland position. in the subsurface, this phase can be correlated with widespread marsh sediments, organic rich clays, and peat horizons, grading eastward into brackish deposits. 3.2. meander to upper delta plain channels and bronze age proto-urban sites the environmental evolution of the last 3000 yr is known in growing detail, since the corresponding sediments are often outcropping, at least at the north and north-east of medieval channel bodies of the po di ferrara and po di primaro (fig. 2c). to the south of this channel system, only sediments younger than 1500 ad are visible, and what is known about the ancient evolution derives from discontinuous subsurface data. the bronze age saw an important po river channel flowing through northern areas (po di adria; bondesan, 1990). meanders were still migrating at the north-west of ferrara (fig. 2c) and a po channel already flowed at the southern side of the future urban centre. bronze age sites are well documented at the west of ferrara (bondeno, fig. 1c, cremaschi et al., 1980). photo interpretation evidence suggesting the existence of similar sites in the ferrara region has yet to be confirmed by stratigraphic and archaeological excavation. evidence is however clear of a diffuse human colonisation of the lower alluvial plain area, in bronze age t ime. the bronze age sett lement (terramare civilisation) was terminated by large environmental modification and human abandonment through large alluvial plain areas of the po river basin (cremaschi et al., 2006). 3.3. etruscan to roman age fluvial channel stability and agricultural colonisation of the plain during etruscan times, the po river flowed through the site of ferrara and formed a large delta lobe prograding into the adriatic sea, about 60 km downstream from the present-day town (fig. 4). on the front of this delta lobe, the etruscan town of spina flourished for a few centuries, soon to decay, also because of the silting up of its port, induced by the depositional progradation of the coastline. the bronze age and the etruscan sites suffered repeated episodes of abandonment and never developed into later times towns. the widening of the sediment outcrop area, the availability of archaeological data, and the starting of the literary transmission of geographic information allow a more precise reconstruction of the roman age palaeogeography (fig. 4a). during roman empire times, marsh areas were reduced in extension and human colonisation widespread, in the lower alluvial plain and delta top areas. the main po river channel still formed a meandering belt at the west of ferrara (figs. 2c, 4a), and flowed at the south of the future town area, following a path that was to persist into the medieval time po di ferrara (figs. 2c, 4a, 4b). a few kilometres to the east of the modern town (near cona, at the trigaboli site reported by strabo’s geographya, fig. 1), the ancient po river diverged into two distributary channels, the carbonarae, at the north, and the eridanum, at the south, according to plinius’ naturalis historia. the northern distributary channel fed a small delta lobe, where the (volana) mouth was active. the larger southern flow (eridanum) further split into several terminal distributary channels, feeding the progradation of a large delta lobe into the open sea, at the south of the present-day site of comacchio (fig. 4b). the previous town of spina was almost abandoned, within delta top marshes. during late republican and imperial times, human intervention on the fluvial drainage system was massif, as suggested by evidence of river artificial embankment, the rectilinearisation of the eridanum channel, in the verginese zone, and the canalisation of the santerno river (vatrenus), in the filo d’argenta area, at the landward edge of the eridanum delta lobe (fig. 4a). human intervention stabilised the drainage framework for a comparatively long period of time. ongoing subsurface research is suggesting that, during roman or pre-roman times, the reno river flowed into the po at the modern site of ferrara (borgo san luca, fig. 5). the ancient reno river channel was associated with a road from bologna (bononia), well documented as far as maccaretolo (fig. 4a), but probably reaching the ferrara area. the po river levees provided a pathway for a regional road crossing the future site of the study town, the “ad hostiliam per padum” (i.e. to the town of ostilia along the po river) depicted by the peutingerian map (pars v, ciurletti, 1991). along this fluvial path the village of vicus varianus was located, likely to be identified with the present-day vigarano pieve (fig. 4a). other important sites (vicus habentia = voghenza, vercellae = verginese; stefani, 2006) were thread along the main po delta distributary channel, the eridanum (uggeri, 1989), which was also associated with river bank roads. through the coastal region, the via popilia connected rimini (ariminum) to ravenna, 361the interaction of geological and anthropic processes ... adria (atria), and altino (altinum), running on fossil aeolian dunes, largely dating back to late bronze age times. although ferrara is the only city of the emiliaromagna region lacking a roman time urban template, its region was nevertheless rich in agricultural sites and land reclamation works. a dense colonisation is documented by the common occurrence of roman finding and by the photo-interpretation evidence, at the west, north and east of ferrara. land reclamation canals and agricultural subdivision are visible, showing an irregular geometry influenced by the local geomorphic and stratigraphic framework. a cluster of roman sites occurs on meander river sand bodies, at the north-west of ferrara (star symbols on fig. 2c). systematic archaeological investigation have been performed only at a few localities, such as in the roman villa built on point-bar sands near cassana (fig. 1c), at the west of ferrara (uggeri, 1989). in the southern portion of the ferrara province, the depositional evolution on the contrary prevents the roman remains from being easily discovered, since they are buried at depth of even 6-7 m. in the ferrara province (fig. 4), just a few of the roman sites were to survive into medieval structures, the majority of them fading away at around the demise time of the roman empire, during a dramatic reorganisation phase of the fluvial system. the present-day inheritance of the roman structures is therefore comparatively reduced in the ferrara area, in sharp contrast with the continuity recorded through the via aemilia belt, both at the east and west of bologna. the roman po river levee was however to play a major role in the following urban genesis, by providing the matrix pathway to the middle age linear town implantation. 3.4. early medieval reorganisation of the fluvial system and the town implantation 3.4.1. the palaeogeographic framework of the urban nucleation following the fall of the roman empire, a major restructuring of the river drainage framework took place (fig. 4b), induced by a climate shift toward cooler and moister conditions (bib.; veggiani, 1994) and by the abandoning of the extensive hydraulic works that forced the drainage system into an artificial unstable state. a new fluvial framework eventually emerged from a phase of chaotic disorganisation and flooding, associated with a speeding up of the riverine sedimentation (cremaschi & gasperi, 1989). this phase corresponds to the widespread flooding of the po and venetian plain referred by a relevant historic source of the time (fuit aquae diluvium in finibus venetiarum et liguriae seu ceteris regionibus italiae, in paoulus diaconus’ historia langobardorum; crivellucci, 1914). the phase is geologically recorded by widespread peat horizons and by inland delta bodies, developed from crevasse channels. north-west of bologna, fluvial avulsion generated a new channel of the reno river, flowing to the west of the roman time river. the abandoned reno levees stood for a while elevated, preventing the drainage of overland water and thus inducing widespread marsh formation. a new po river system also developed, through the upstream interconnection of various channels. these structures were often inherited from previous phases and sometimes even derived from the capturing of artificial canals, as it is the case of the new southern distributary channel of the po, the primaro. this channel reused a roman canalisation of the santerno water, near filo di argenta, (see previous paragraph and fig. 4a, b). the fluvial reorganisation process joined upstream this channel to the main po river flux, using a crevasse passage, within the future urban area of ferrara. this crevasse pierced the po river levee immediately downstream of the joining point of the roman time reno river with the po di ferrara channel (marks in figs. 2c, 4a, 5). during these early medieval times, the northern channel of the po di volano was also generated. the new main distributary channel diverged from the former carbonarae po at contrapò and flowed eastward, toward its prograding delta lobe, at the east of codigoro (fig. 4b). the new channel funnelled the majority of the po river flux and thus drained out the main roman time distributary channel, the eridanum. during this drainage reorganisation phase, the majority of the roman settlements was abandoned and often buried by fluvial and marsh sediments, while a new generation of nuclei developed, on the levees of the recently generated po channels. argenta was founded on the northern levee of the new po di primaro channel, along the pathway toward ravenna. in the lagoon flooding the northern side of the roman time abandoned delta lobe (eridanum), the port town of comacchio was growing. at the apex of the fast prograding po di volano delta lobe, the benedictine abbey of pomposa was founded, probably in the 7th century. along the coastline, a new route (via romea) developed, passing by the pomposa abbey, while the older roman road (popilia) remained active at the west on aeolian dunes, site of medieval nuclei (san basilio). the coastal roads were easily connected to the ferrara region through the new levee pathways, along the po di primaro and po di volano channels. 3.4.2. the sitting of the early settlement of ferrara during the early middle ages (7th century), the new geographic scenario (previous paragraph) guided the sitting of a fortification that was to provide the aggregation nucleus to ferrara. this fortification is in literature known as castrum (patitucci uggeri, 1989), after a 15th century source (flavio biondo), describing a castrum foundation on the po river bank by greeks against longobards. even if not supported by sound written documentation, the story fits well with the physical evidence preserved by the present-day town. the convergence of terrestrial and fluvial pathways into this boundary area guided the location of the new military nucleus and supported its following expansion. the ferrara site was at the junction of the fluvial and levee routes from ravenna, argenta, comacchio and pomposa that followed the distributary channels of the po river (fig. 4b). the po river pathway led upstream to inner po plain regions, as far as the longobard capital town of pavia. a road from bologna probably still existed on the roman time reno river sedimentary body, reaching the po levee in front of the new military site (figs. 2, 4a, 5). other paths converged into the castrum site, following pre-roman fluvial bodies (figs. 2c, 5), at the north-west of the town (from mizzana to 362 m. stefani & m. zuppiroli fig. 3 geometric scheme of the stratigraphic relationships (a) between upper pleistocene synglacial sands and holocene po and reno fluvial deposits in the ferrara urban area, along a north-south profile. digital elevation model (b) of the historic centre of ferrara (location in fig. 2c), recording the morphological expression of the northern levee sediments of the po di ferrara river; the area ranges in elevation from + 3.7 m to + 12.2 m above sea level. an example of historic map representation of the ancient drainage system (c), recording valuable information on the environmental and urban history of the area. two photographs (d1, d2) illustrating the morphological affect of the levee-top sedimentation and during the medieval urban growth; the arch structure is deeply buried by sediment and anthropic deposits. in medieval times, the urban growth was mainly confined to the more elevated levee body, depicted by yellow and green colours in the elevation model; during the late 15th century, the town expansion colonised the morphological depression described by the blue colours, in the northern portion of the model. schema geometrico delle relazioni stratigrafiche fra i corpi sedimentari del pleistocene superiore e dell’olocene lungo un transetto nord-sud, nell’area urbana di ferrara (a). modello numerico della topografia del centro storico (b), localizzazione in fig. 2c), che registra una variazione altimetrica da 3,7 a 12,2 m sul livello del mare; il microrilievo registra chiaramente l’argine settentrionale del po di ferrara ed il suo rapporto con l’adiacente depressione interalvea. un esempio di cartografia storica (c), che descrivendo l’andamento del reticolo fognario storico fornisce importanti informazioni sull’evoluzione dell’area urbana. due fotografie (d1, d2) che illustrano l’aggradazione del corpo arginale avvenuta durante la crescita medievale della città; notare i piedritti dell’arco profondamente sepolti da sedimenti e depositi antropici. durante il medioevo, la crescita urbana fu sostanzialmente confinata al corpo arginale, rappresentato nel modello topografico dai colori gialli e verde-chiaro; solo fra xv e xvi secolo la grande espansione rinascimentale riuscì a colonizzare la depressione interalvea, rappresentata dai colori bluastri. 363 fig. 4 schematic reconstruction of the palaeogeographic framework of the ferrara province during roman empire times (a) and in the late 12th century (b). during early medieval times, the area experienced a widespread fluvial system reorganization that controlled the foundation site of ferrara; the northern po channel developed in the 12th century and it is only one surviving into the present-day. ricostruzione paleogeografica della provincia di ferrara in epoca imperiale (a) e alla fine del xii secolo (b). durante il primo medioevo, l'area fu soggetta ad una drammatica fase di riorganizzazione del reticolo fluviale, che controllò la localizzazione del nucleo originario di ferrara. l’attuale alveo passante a nord della città si venne individuando solo durante il xii secolo. the interaction of geological and anthropic processes ... western areas), in the core of the future city centre (borgo leoni toward the venetian region, figs. 2c, 3b), and within the triangular area between the po di volano and po di primaro (from san giorgio to voghenza). a location adjacent to the river provided a plentiful source of surface and underground fresh water, even during the dry summer seasons, a factor that was to affect the urban development for many centuries to follow (stefani & zuppiroli, 2010). the southern border of the fortified structure of the castrum was tangential to the levee crest, over which the regional pathway from the sea to the inner po plain was passing (phase 1 in fig. 5). the early settlers chose a sandy crevasse splay structure elevated on the northern levee of the po river as their dwelling place. this site provided drier and firmer ground than the surrounding argillaceous interfluvial depressions (figs. 2, 4, 5). the choice of a risen area was particularly important in a time of widespread river flooding. the ancient fortification site still stands out as the “highest” point of the town (present geoidal elevation 9.6 m; figs. 3b, 5). the southern side of the fortified structure was about 240 m long, its area 35,000 squared metres (phase 1 in fig. 5). the nucleus was surrounded by a wood palisade and was the site of at least one church (san pietro) and of about two dozens of wood houses, with associated kitchen-gardens and stalls. the detailed architectural investigation of the area reveals that the present-day brick building structure still preserve a good memory of these ancestral wood structures (dalla negra et al., 2009). 3.4.3. linear growth of the town on both the northern and southern levees of the po river the early expansion of the build up area was confined to the levee crest, protected from long lasting flooding (fig. 3b). about 700 m at the north-west of the primary nucleus, a small village colonised the san michele channel body (1a in fig. 5). the attraction between these two nuclei triggered the expansion of the proto-urban tissue, along the interposed levee road (phase 2 in fig. 5). in a text dated to the 757 ad, the name ferraria is for the first time documented, as a former byzantine site occupied by longobard forces; in a 936 ad manuscript, ferrara is already referred to as a town (civitas; castagnetti, 1985). during carolingian times, the po river acquired a growing transportation importance. the upstream transport of sea salt crossed the flow of agricultural and hunting products and of the alpine pennidic serpentinites, out of which containers for liquids were produced. the river port activity triggered the development of a triangular market square on levee deposits (figs. 1b, 5), to the west of the original fortified area (platea publica maior, quoted in 972 ad; bocchi, 1974). archaeological investigation (add & ward perkins, 1991; cremaschi & nicosia, 2010) has revealed, in 10th and 11th centuries levels, the intercalation of crevasse deposits and anthropic materials, producing fast ground aggradation. during the middle ages, the urban tissue grew in an almost symmetrical way, on both the northern and southern banks of the po river. the urban structures on the southern levee are however now largely obliterated by the widespread man induced destruction, occurred since the 16th century (paragraph 3.8). during early 364 m. stefani & m. zuppiroli medieval times, the first cathedral of san giorgio was built, at the junction of the right levee of the po di volano, of the left levee of the po di primaro. the episcopal church is well documented in this site at the middle of the 10th century. in the early 11th century, churches and houses were thread along the southern levee road of the po di ferrara, facing the developing northern nucleus (franceschini, 1981). the southern urban area then constantly grew through the middle ages, to give origin to two large districts (borgo di san giacomo and borgo di san luca), elongated through the bent levee structure (figs. 3b, 5). on the northern bank of the po di ferrara river, at the beginning of the 11th century, upstream of the older castrum nucleus, a feudal castle was built (castel tedaldo, fig. 1b). during the first half of the 11th century, the urbanised area on the northern levee broadly stretched over a distance of about 2300 m, with a width of often less than 100 m (phase 2 in fig. 5). the discontinuously built area covered a surface of about 30 hectares. between the 11th and 12th centuries, the town expansion slowly reached the base of the northern levee sedimentary body (phase 3 in fig. 5), consolidating there a continuous defensive line, associated to small drainage canals (via garibaldi and via contrari, fig. 1b). in the meanwhile, the po river pathway and the port works polarised the commerce activity along the sandy river-bank southern border of the town (via ripagrande = main riverbank road). 3.5. late medieval fluvial reorganisation and discrete expansion episodes of the town 3.5.1. origin of the modern po river channel and expansion events of the town during the 12th century, the new distributary channel of the po river developed, which led to the formation of the present-day po di venezia channel, flowing just at the north of ferrara (figs. 1c, 4b). the new channel diverged about 30 km upstream from the town. the slowly subsiding casaglia anticline area (paragraph 1.2) acted as a repulsion region for the river flow, in such a way that the po river bifurcated at ficarolo, into the new po di venezia and the older po di ferrara channels (fig. 4b). during the 13th century, the new northern channel still had a minor importance, and the southern flows of the po di volano and po di primano remained active, fed by the po di ferrara. the new po di venezia channel however progressively funnelled northward the main river flow, gradually draining out the older southern fluvial structures. marshes initially expanded both at the north and south of the town. during the later middle ages, the climate became warmer and dryer (veggiani, 1986), the fluvial drainage structures stabilised, and land reclamation works and protective dam construction were built to allow the town to grow out of its original levee location. in the first half of the 12th century, the town became politically independent (libero comune, 1116 ad). an early decision of the new political entity was the building of a majestic cathedral, on the distal portion of the po di ferrara levee, at the northern border of the town. the five naves church building was cleverly adapted to the poor geotechnical properties of the cohesive sediments, through the structure load reparaon the winding sediment body of the san michele channel (borgo di san guglielmo, figs. 3b, 5). the interfluvial argillaceous depressions remained largely unbuilt. despite the land reclamation works and the river embankment effort, flooding remained commonplace in the urban area (flooding documented in 1328, 1362, 1365, 1419, 1470, 1480, 1481, 1493, 1498; bondesan et al., 1995). 3.6. land reclamation works and renaissance town expansion into interfluvial depressions the middle of the 15th century marked a change in the attitude of the estense ruling family toward the regional management. discontinuous local intervention gave way to large geometric planning and massive land reclamation works, co-ordinated at the regional scale. advanced topographic survey techniques were developed and large economic resources utilised. in the process, the natural patterns rooted in the geological substratum were often overlooked and obliterated. the marsh region at the north-west of the town (bonifica della diamantina, fig. 1c) was dried, at the middle of the 15th century. further embankment were built along the po di ferrara channel and the district surrounding the former san antonio island was surrounded by new town-walls, at around 1450 (addizione di borso d'este; phase 6 in fig. 5). a new castle (castel nuovo) was built on the po di ferrara channel body, upstream to the former san antonio island. in the meanwhile, new building progressively colonised the argillaceous interfluvial depression, at the north of the medieval town of ferrara (church of santa maria degli angeli, villa of belfiore, monastery of san cristoforo, fig. 1b). these edifices fore-run a massive town expansion and new fortification building, made possible by the regional land reclamation works. an urgent need of an expansion and modernisation of the town fortification was at the time prompted by the southward expansion of the venice republic, which reached the po di venezia channel, just a few kilometres to the north of ferrara, following the 1484 victory in the “war of salt”. at the end of the 15th century, the town surface was more then doubled, through the construction of a very large addition (addizione erculea), occupying interfluvial argillaceous depressions (fig. 3b). topographic lows of less than 4 m of elevation were incorporated into the enlarged town that reached a surface of more than 440 hectares and a population between 40,000 and 50,000 people. ferrara therefore joined the number of the largest town of europe. large unbuilt areas were however to persist within the town-walls until the present (fig. 1b). the new fortifications were important also for protecting the urban area from the recurrent flooding, such as the 1522, 1579, and 1585 ones. this protection remained affective for a long period of time, as for instance documented by the 1705 flooding episode. the poor geotechnical properties of the organic rich mud supporting the new edifices induced significant construction problems, witnessed by large building deformation (for example the church of san cristoforo, fig. 1b). the new leaving on low permeability mud sediments reduced the water availability and prevented the phreatic well exploitation. water reservoirs were therefore realised, with artificial sand infilling of under365 tion onto the external walls. during the 13th century, the urban development style gradually shifted from a “spontaneous” growth of the urban tissue, through individual building cells rooting into the geomorphological template, to the planning of discrete town expansion episodes (addizioni), fore-run by hydraulic and land reclamation works. the two growth styles often coexisted during late middle ages. a long protective earth dam (argine del traversagno, fig. 1c) was built at the north-west of the urban centre, connecting the northern embankment of the po di ferrara with the southern levee of the po di venezia (fig. 1c) and protecting the town from flooding. between the 12th and 13th centuries, a new district (borgo novo) was developed at the north of the new cathedral under construction; on comparatively low laying argillaceous land (phase 4 in fig. 5). during the latter century, dominican and franciscan convents were placed at the opposite side of the new northern urban expansion, on a silty mud interfluvial substratum. at the same time, the brick building progressively pervaded and hardened the previous wood cell tissue, while the street framework experienced extensive reorganisation, with the closing of many roads and the opening of several others. 3.5.2. flux reduction in the southern channels of the po and urban colonisation of river deposits during the late middle ages, the progressive reduction of the water flow through the southern po di ferrara channel induced the accumulation of sand islands, rapidly colonised by buildings, as it was the case of the san antonio monastery on the homonymous island (phase 5 in fig. 5). the lateral growth of the river sand beaches allowed a moderate expansion of the town toward the river axis, at the south of via ripagrane (paragraph 3.4). during the 13th and 14th centuries, the expanding urban nucleus was surrounded by brick town-walls. the southern fortifications were characterised by a peculiar concave geometry, following the river bank shape (phase 5 in fig. 5). the southern wall structure is still followed by ancient drainage structures (fig. 3c). the northern walls were built at the margin of the interfluvial depression, in a more morphologically uniform framework, and therefore they were more rectilinear. during the 14th century, the town had reached a length of about 2400 m and a surface extension of 140 hectares (phase 5 in fig. 5). the estense castle of san michele was founded in 1385, at the northern town-wall line, on the ancient san michele channel body (figs. 1b, 2b, 5). at the end of the 14th century, the further reduction of the water flow in the po di ferrara enabled the joining of the san antonio island to the town area. this portion of town still preserves clear evidence of the river channel morphology (fig. 3b). large sandy islands accumulated upstream to the town (boschetto and belvedere islands, figs. 1b, 2c). built-up districts were further growing both along the southern levee body of the po di ferrara (borgo di san giacomo, borgo di san luca, borgo della misericordia, fig. 5) and on the northern one. on the latter sedimentary body, districts were developing upstream (borgo di mizzana) and downstream (borgo della pioppa) of the walled town. more buildings were constructed toward the north-east, 366 fig. 5 synoptic representation of the relationship linking (1) sedimentary substratum, (2) topographic framework, (3) route pathways, and (4) urban growth phases. (1) colours lines depict the different sedimentary facies; (2) contour lines describe the digital elevation model, with a 20 cm spacing; (3) the green lines illustrate the regional roads framework, (4) the red boundary-lines and red numbers correspond to the medieval growth phases of the town; the red mark indicates the probable confluence site of the roman time reno river into the po channel. the light blue boxes indicate the trace of the stratigraphic-architectural profiles of fig. 6. for the regional framing of the map, see fig. 2. the po di ferrara sedimentary body bifurcates into the po di volano and po di primano distributary channel deposits. the adjacent natural levee units supported the development of the medieval town, which nucleated on a crevasse splay (1) and then grew in an elongated way on the levee crest (2), to then slowly expand toward more distal portions of the levee body (3-4). fluvial island and channel units were colonised only at later times (5), following a river flux decay rappresentazione sinottica dello stretto legame esistente fra (1) composizione sedimentologica del substrato stratigrafico, indicato dalle diverse campiture cromatiche, (2) il contesto topografico, descritto da isoipse continue con equidistanza di 20 cm, (3) l’andamento dei percorsi antropici regionali, indicato dalle tracce verdi, e (4) le fasi di nucleazione e crescita del tessuto urbano in età medievale, indicate dai confini e dai numeri in rosso. il segno arancione indica il probabile sito di confluenza del reno di età romana con il po. i rettangoli azzurri indicano la localizzazione dei profili stratigrafico-architettonici di fig. 6. per la collocazione regionale della carta, vedere la fig. 2. il corpo di canale fluviale del po di ferrara si biforca presso la punta di san giorgio nei depositi del po di volano e del po di primaro. questi corpi sono fiancheggiati da depositi di argine naturale, su cui si svilupparono gli insediamenti medievali. il nucleo iniziale della città (1) si insediò su di un ventaglio da rotta parte dell’argine naturale destro del po, lungo cui la città si espanse poi in modo lineare (2); solo dopo il xii secolo la città si espanse lentamente verso la depressione interalvea (3-4). l’isola fluviale di san antonio in polesine e le sponde del fiume poterono essere colonizzate solo durante il basso medioevo (5), grazie ad una riduzione del flusso fluviale. 367 fig. 6 geological-architectural profiles illustrating the strong genetic connection of the stratigraphic substratum, the surface morphology, the building structures, and the present day degradation state of the brick walls. substratum stratigraphy derived form cone penetration tests, stratigraphic coring, and trench examination; building data from architecture surveying. profiles location in fig. 5. structures built on permeable fluvial sand are characterised by very high levels of water impregnation and wall degradation, whereas building on low permeability mud are comparatively dry, despite their low topographic placement. profili stratigrafico-architettonici che illustrano i legami genetici esistenti fra composizione sedimentologica del sottosuolo, morfologia della superficie topografica, strutture architettoniche storiche e lo stato di degrado delle murature laterizie. la ricostruzione di sottosuolo deriva dalla correlazione di prove penetrometriche, carotaggi stratigrafici e dall’esame di trincee di scavo; i dati sugli edifici dal rilievo architettonico. le strutture costruite sui corpi permeabili di sabbie fluviali mostrano livelli di imbibizione idrica e degrado molto più accentuati di quelli fondati su terreni argilloso-limosi coesivi, a bassa permeabilità e ad alta tensione osmotica, nonostante che questi ultimi affiorino alle quote topografiche più basse. posizione delle sezioni in fig. 5. the interaction of geological and anthropic processes ... ground brick walled cistern, dug into the argillaceous sediments (stefani & zuppiroli, 2010). visionary hydraulic works were also performed. salty waters from the casaglia anticline structure were brought into an estense court spa (delizia del belvedere), and fresh water was pumped from the po di ferrara stream, at the south-western corner of the town, using an hydraulic wheel, and brought to the central court square, near the cathedral (zuppiroli, 2008). 3.7. death of the southern po channels and seismic damage of the town the southern distributary channels of the po river (po di ferrara, volano, primaro) eventually experienced a sudden demise, triggered by an ill-fated attempt (1522) to force the reno river water to reach the adriatic sea through them. the reduced morphological gradients and the large sediment load of the reno river suddenly silted up the po di ferrara channel, preventing any further water flow to the sea. the reno river input formed a large shallow water lake (valle della sammartina), which was to be progressively filled by apennines-derived sediments. an earthquake significantly affected the town in the year 1570, (boschi et al., 1997). large edifices built on interfluvial depression mud suffered minor damage (for example: san benedetto and san cristoforo churches; palazzo dei diamanti, fig. 1b), whereas buildings on fluvial sands, with maximum grain size in the mm order, suffered catastrophic collapses, as it was the case of castel nuovo and of the church of san paolo (fig. 1b). these collapses were possibly related to co-seismic thixotropic fluidification of water saturated river sands. 3.8. widespread re-flooding and urban structure decay the ending of the 16th century brought major alteration to the urban structures, triggered by both fluvial dynamic modification and political change. the silting up of the southern po river channels (see previous paragraph) and the danger produced by the new artillery menaces prompted the building on fluvial sands of bastion fortification at the southern side of the town during the 17th century (figs. 1b, 5) and, at the beginning of the 17th century, of a large, star-shaped fortress (fortezza pontificia, fig. 1b), incorporating part of a former fluvial island (belvedere, fig. 1b). this large works induced massive geomorphic modification, obliterating the riverine morphology and destroying the peripheral districts previously surrounding the town (borghi di mizzana, san giacomo, san luca, pioppa, figs. 1, 5). several environmental and anthropic factors combined during the following centuries to generate a long lasting socio-economic decay of the town, which was to persist into the early 20th century. (a) in the 16th century, the drying up of the po di ferrara channel brought an end to any port activity into the town. the apennines-derived rivers fed large fresh water environments between bologna to the southern border of ferrara, reducing the agricultural space and preventing inland communication. (b) during the 17th century, sediment compaction subsidence and the fast progradation of the man-induced modern po delta severely disrupted the drainage system of the region, thus inducing the re-flooding of the previously reclaimed lands, through large areas to the east of the town. this re-flooding also severely reduced the agricultural potential of the region. (c) during the 17th and 18th centuries, a shift toward moister and cooler climate condition (“small ice age”; veggiani, 1984) supported catastrophic fluvial flooding episodes (for example, the 1705 one). the climate change reduced the agriculture production of the region and induced the marginalisation of the grape. (d) the new large marsh areas were supported the spreading out of endemic malaria and the area was also affected by severe plague episodes. (e) the papal rule of the town (1598-1859) made the region a marginal one in the church state. these factors combined together to induce long-lasting socio-economic stagnation, ferrara population halving to less than 25,000 persons (18th century), urban structures decay and fossilisation, and thinning out of the town building tissue. 3.9. the artificialisation of the fluvial system and the modern urban evolution during the 18th century, massive hydraulic works eventually succeeded into bringing the reno water stream to the adriatic sea, through long artificial canals and the reactivation of the previous southernmost distributary channel of the po river (po di primaro; angelini, 1993). wetlands however remained commonplace in the town vicinity, until the steam-supported land reclamation works, performed during the second half of the 19th century. after the long period of economic and demographic decay, massive urban expansion restarted only after the second world war, disregarding any geological and environmental constrains, and therefore exposing the town to significant environmental hazards from river flooding, seismic damage and underground water pollution (bondesan, 1989). the sediment distribution in the shallow subsurface affects the local response to seismic wave acceleration, the circulation of pollutants, and the moistering of building structures. structures built on low permeability, high osmotic tension mud are generally comparatively dry, despite their being built into topographic low area, whereas building on permeable fluvial channel sand are characterised by elevated level of water impregnation and wall degradation (fig. 6). a close relationship therefore links the depositional evolution of the area, the stratigraphic architecture of the close subsurface, the historic evolution of the town and the present degradation state of the town buildings. 4. conclusions stratigraphy, sedimentology, geomorphology, historiography, and architecture investigations were integrated to generate an interdisciplinary understanding of the dynamic interaction between natural and anthropic processes shaping the urban structure of ferrara and the environmental evolution of the surroun368 m. stefani & m. zuppiroli ding plain. intervals of drainage system stability were punctuated by episodes of fluvial avulsion, drainage disorganisation, and widespread flooding, leading to palaeogeography innovation events. during these events, renewed fluvial stability repeatedly emerged from the downand up-stream interconnection of river channels. the fluvial reorganisation episodes were controlled by both allocyclic factors, like climate change, and local autocyclic processes, like the instability induced by the depositional rising of the river channels. in the ferrara area, the depositional processes were significantly affected by both the large late quaternary climatic fluctuations and the ongoing compressional deformation of the foreland basin. the punctuated nature of the fluvial equilibria induced repeated episodes of human colonisation and urban site development, terminated by widespread abandonment. through proto-historic and historic times, at least three main cycles of human settlement and urban growth can be detected, a bronze age cycle, a massive roman colonisation of the area, and an early medieval to modern time cycle, during the early development of which ferrara nucleated. the study was therefore particularly focused on the later one. the fluvial sands inherited form the glacial phase affected the depositional dynamics even in historic times, supporting the cannibalistic development of meander point bars. in the study area, meander river deposition progressively gave way to lower alluvial plain and inner delta plain deposits. during roman times, a comparatively warm and dry climate scenario was associated with a long-lasting stabilisation of the delta system, helped by massive anthropic intervention. the fall of the roman empire structures and a climate shift toward cooler and moister conditions was matched with a massive river reorganisation, the diffuse abandoning of roman site and the nucleation of new villages and towns. during early medieval times, the converging of fluvial and terrestrial routes suggested the sitting of a small fortification, which was to provide the nucleus to the future ferrara urban growth. until the 12th century, the town grew linearly, over the northern natural levee of the po river. during later middle ages, the town slowly colonised base of levee and former fluvial channel settings. the medieval urban tissue was largely influenced by the underlying depositional and geomorphic structures. in late medieval and renaissance times, large land reclamation works were performed, enabling the design of a majestic urban expansion onto interfluvial depression argillaceous sediments. the water flux through the southern channels of the po river was stopped during the 16th century, by the silting up induced by an ill-fated attempt to force the reno river water into reaching the adriatic sea through these distributaries. the 1570 earthquake produced different effects according to the various stratigraphic substrata. during the following centuries, large fresh water marsh surrounded the urban area that experienced a sever decay. the urban structures started to expand again at a faster pace only after the second world war, disregarding the geological, ecological, and historic features of the area and thus leaving the town exposed to dangers like floods, earthquake and pollution. 5. acknowledgements this contribution synthesises some of the result of the interdisciplinary research project on town structures inspired and co-ordinated by prof. arch. riccardo dalla negra, at the architecture department of the ferrara university, who is thanked together with arch. rita fabbri for their long-lasting sharing of ideas on the urban growth and architectural shape of ferrara. we thank marco bondesàn, for important scientific discussion; alessandro fontana, for scientific discussion and information on the venetian plain geology; paolo russo and alberto pellegrinell i , facoltà di ingegneria, università di ferrara, for providing the valuable altimetric measures on the ferrara town centre; raffaele pignone of the ufficio geologico, sismico e dei suoli della regione emilia-romagna, for the economic support to the research in the codigoro area and for providing subsurface data; tiziano tagliani, mayor of ferrara, for organisation support; alberto bassi and lorella dall’olio of the ferrara municipality, for providing subsurface data. 6. references add d. & ward perkins b. (1991) the development of urban domestic housing in northern italy. the evidence of excavation on the san romano site, ferrara. the accordia research papers, 2, 105-127. amorosi a. (2008) delineating aquifer geometry within a sequence stratigraphic framework: evidence from the quaternary of southern po river basin, northern italy. in: amorosi a., haq b. u. & sabato l. (eds.), advances in application of sequence stratigraphy in italy. geoacta special publication, 1, 1-14. amorosi a., cibìn u., severi p. & stefani m. (2004) late quaternary evolution of the po plain from surface and subsurface data: a traverse form the apennines to the adriatic sea. 32° international geological congress, florence, field guide book, 1, b24, 200 pp. angelini w. (1993) richiami bibliografici intorno all’annosa polemica sulle acque padane a meridione di ferrara (cinquecento tardo settecento). in: aa.vv. (ed.), la pianura e le acque tra bologna e ferrara: un problema secolare. atti del convegno di studi, cento 18-20 marzo 1983. centro studi “g. baruffaldi”, 17-34. bartolomei g., bondesan m., dal cin r., mase’ g. & vuillermin f. (1975) studio geologico coordinato per la pianificazione territoriale del comune di ferrara. memorie società geologica italiana, 14, 165205. bigi g., cosentino d., parotto m., sartori r. & scandone p. (1990) modello strutturale tridimensionale dell’ ital ia, foglio n.1 alla scala 1:500000 . s.e.l.c.a., firenze. bocchi f. (1974) note di storia urbanistica ferrarese nell'alto medioevo. deputazione provinciale ferrarese di storia patria, ferrara, 88 pp. bocchi f. (1976) uomini e terra nei borghi ferraresi: il catasto parcellare del 1494. ferrariae decus, ferrara, 200 pp. 369the interaction of geological and anthropic processes ... bondesan m. (1989) geomorphological hazards in the po delta and adjacent areas. suppl. geografia fisica dinamica quaternaria, 2, 25-33. bondesan m. (1990) l'area deltizia padana: caratteri geografici e geomorfologici. in: bondesan m. (eds.), il parco del delta del po, studi ed immagini, v. 1: l'ambiente come risorsa: il territorio e i suoi sistemi naturali. spazio libri, ferrara, 9-48. bondesan m., dal cin r. & mantovani m. g. (1974) depositi fluviali wurmiani in un pozzo terebrato presso ferrara. annali università ferrara, n.s. 5, 8, 147-163. bondesan m., ferri r. & stefani m. (1995) rapporti fra lo sviluppo urbano di ferrara e l’evoluzione idrografica, sedimentaria e geomorfologica del territorio. in: visser travagli a. m. (ed.), ferrara nel medioevo: topografia storica e archeologia urbana. grafis, casalecchio di reno (bo), 27-42. bondesan m., gatti m. & russo p. (1997) movimenti verticali del suolo nella pianura padana orientale desumibili dai dati i.g.m. fino a tutto il 1990. bollettino di geodesia e scienze affini, a. 56, 2, 141-172. boschi e., guidoboni e., ferrari g., valensise g. & gasperini p. (1997) catalogo dei forti terremoti in italia dal 461 a.c. al 1990. istituto nazionale di geofisica e s.g.a., bologna, 644 pp. castagnetti a. (1985) società e politica a ferrara dall’età postcarolingia alla signoria estense: secoli xxiii. pàtron, bologna, 321 pp. castellarin a., eva c., giglia g. & vai g. b. (1996) analisi strutturale del fronte appenninico padano. g. geol., s. 3°, 47, 47-75. castiglioni g. b. (ed.), (1999) carta geomorfologica della pianura padana al 1:250.000. murst, s.e.l.c.a., firenze. castiglioni, g. b. & pellegrini g. b. (eds), (2001) note illustrative della carta geomorfologia della pianura padana. supplementi di geografia fisica e quaternaria. sup. 4, 1-204. ciurletti g. (eds.), (1991) tabula peutingeriana, codex videbonensis. completa di tutti gli 11 segmenti nel formato originale 76x42. pars v. edizioni u.c.t., trento. consorzio di bonifica i circondario polesine di ferrara & consorzio di bonifica ii circondario polesine di san giorgio (2005) il catasto carafa (cd-rom). gallo pomi group, milano. correggiari a., cattaneo a. & trincardi f. (2005) depositional patterns in the late holocene po delta system. in: janok p. et. al. (eds.), deltas old and new. in: s.e.p.m. sp. pub. cremaschi m., bernabà brea m., tirabassi j., d’agostini a., dall’aglio p. l., magri s., barrichi w., marchesini a. & nipoti s. (1980) l’evoluzione della pianura emiliana durante l’età del bronzo, l’età romana e l’altomedioevo: geomorfologia e insediamenti. padusa, 16, 53-158. cremaschi m. & gasperi g. (1989) la “alluvione” altomedievale di mutina (modena) in rapporto alle variazioni ambientali oloceniche. memorie società geologica italiana, 42, 179-190. cremaschi m. & nicosia c. (2010) corso porta reno, ferrara (northern italy): a study in the formation processes of urban deposits. il quaternario, 23(2bis), 373-376. cremaschi m. & pizzi c. & valsecchi v. (2006) water management and land use in the terramare and a possible climatic co-factor in their abandonment: the case study of the terramara di poviglio santa rosa (northern italy). quaternary international, 151, 87-98. crivellucci a. (eds.), (1914), fonti per la storia d’italia: paulus diaconus historia langobardorum. pp. 48. dalla negra r., fabbri r., stefani m., ambrogio k., conforti a. & zuppiroli m. (2009) ferrara: contributi per la storia urbana. in: bondanelli m. (eds.), problematiche strutturali dell’edilizia storica in zona sismica. contributi al seminario di studi, ferrara 0122 ottobre 2009. geoprociv, ferrara, 103-158. fontana a., mozzi p. & bondesan a. (2004) l’evoluzione geomorfologica della pianura venetofriulana. in: bondesan a. & meneghèl m. (eds.), (2004), 113-136. franceschini a. (1981) istituzioni benedettine in diocesi di ferrara: (sec. x-xv). analecta pomposiana. sate, ferrara, 7-73. galadini f. (2004) quaternary tectonics. in: bosi c. (eds.), quaternary. ital. geol. soc. spec. vol., geology of italy, 161-188. guidoboni e. (1984) riti di calamità: terremoti a ferrara nel 1570-74. quaderni storici xix, 55, 107-136. molinari f. c., boldrini g., severi p., dugoni g., rapti caputo d. & martinelli g. (2007) risorse idriche sotterranee della provincia di ferrara. in: dugoni g. & pignone r. (eds.), risorse idriche sotterranee della provincia di ferrara. db-map, firenze, 7-61. montone p., & mariucci m. t. (1999) active stress along the ne external margin of the apennines: the ferrara arc, northern italy . journal of geodynamics, 28, 251-265. patitucci uggeri s. (1989) “castra" e l’insediamento sparso tra v e viii secolo. in: alfieri n. (eds.), storia di ferrara, l’età antica (2.), 4. a. c. 6. d. c.. g. corbo, ferrara, 407-564. pezzoli s. & venturi s. (eds.), (1987) una carta del ferrarese del 1814. amministrazione provinciale di ferrara, istituto per i beni artistici culturali e naturali della regione emilia romagna, silvana editoriale, amilcare pizzi s.p.a. arti grafiche, cinisello balsamo (mi). pieri m. & groppi g. (1981) subsurface geological structure of the po plain, italy. c.n.r., pubblicazione 414, progetto finalizzato geodinamica, sottoprogetto modello strutturale tridimensionale. 13, 7, roma, 1-11. postpischl d. (eds.), (1985) catalogo dei terremoti italiani dall’anno 1000 al 1980. quaderni de la ricerca scientifica, cnr-pg, 114, vol. 2b, roma. regione emilia-romagna & eni-agip (1998) riserve idriche sotterranee della regione emilia-romagna. in: di dio g. (eds.), s.e.l.c.a., firenze, 120 pp. stefani m. (2006) il contesto paleogeografico e sedimentologico-stratigrafico della necropoli romana del verginese. in berti f. (ed.) mors inmatura. i fadieni e i l loro sepolcreto. quaderni di archeologia dell'emilia romagna, 16, 41-48. stefani m. & cibin u. (2010) note illustrative del foglio geologico 1:50000 187 codigoro. 370 m. stefani & m. zuppiroli stefani m. & vincenzi s. (2005) the interplay of eustasy, cl imate and human activity in the late quaternari depositional evolution and sedimentary architecture of the po delta system. marine geology, 222-223, v-vi, 19-48. stefani m. & zuppiroli m. (2010) il controllo idrogeologico sul degrado delle murature: il caso del centro storico di ferrara. in: scienza e beni culturali, xxvi. 2010. pensare la prevenzione. manufatti, usi, ambienti. atti del convegno di studi, bressanone 13-16 luglio 2010. edizioni arcadia ricerche, venezia, 173-182. stefani m., vincenzi s. & cibìn u. (2003) geologicalstratigraphic map of the central portion of the po delta system at 1/50,000. regione emiliaromagna, s.e.l.c.a., firenze. toscani g., burrato p., dibucci d., seno s. & valensise g. (2008) plio-quaternary tectonic evolution of the northern apennines thrust fronts (bolognaferrara section, italy): seismotectonic implications. 24 pp. uggeri g. (1989) insediamenti, viabilità e commerci di età romana nel ferrarese. in: alfieri n. (eds.), storia di ferrara, l’età antica (1.), 4. secolo ac 6. secolo dc. g. corbo, ferrara, 1-209. veggiani a. (1984) il deterioramento climatico dei secoli xvi-xviii ed i suoi effetti sulla bassa romagna. studi romagnoli, 35, 109-124. veggiani a. (1986) l’ottimo climatico medievale in europa: testimonianze lungo la fascia costiera padano-adriatica. studi romagnoli, 37, 1-26. veggiani a. (1994) i deterioramenti climatici dell’età del ferro e dell’alto medioevo. boll. soc. torricelliana di scienze e lettere, faenza, 45, 3-80. zuppiroli m. (2008) ferrara: il sistema delle acque. proposta di valorizzazione e recupero funzionale dell’ex serbatoio di piazza xxiv maggio. in: fabbri r. (eds.), ferrara architettura 3. novecento. comune di ferrara, ferrara, 59-88 and 102-104. 371the interaction of geological and anthropic processes ... ms. ricevuto il 21 luglio 2010 testo definitivo ricevuto il 13 novembre 2010 ms. received: july 31, 2010 final text received: november 3, 2010 09mantovanietal quaternary geodynamics of the apennine belt mantovani e.1, viti m.1, babbucci d.1, ferrini m.2, d’intinosante v.2, cenni n.3 1dip. di scienze della terra, univ. di siena, e-mail: mantovani@unisi.it 2servizio sismico regione toscana 3dip. di fisica, univ. di bologna abstract: e. mantovani et al., quaternary geodynamics of the apennine belt. (issn it 0394-3356, 2009). the drastic tectonic reorganization that the apennine belt has undergone around the middle pleistocene is interpreted as a consequence of the fact that since that time the adriatic plate has accelerated carrying the outer sectors of the apennines, formed by the molise-sannio units, the eastern part of the latium-abruzzi platform and the romagna-marche-umbria and ligurian units. the consequent oblique separation between such mobile units and the western almost fixed part of the belt has been accommodated by sinistral transtensional deformation in the axial part of the chain. during this process the belt-parallel push of the adriatic has caused rapid uplift, bowing and outward extrusion of the outer mobile units. it is argued that this geodynamic interpretation provides a plausible and coherent explanation for the observed deformation pattern in the apennines and that, on the other hand, such a result can hardly be achieved by the alternative geodynamic models so far proposed. riassunto: e. mantovani et al., geodinamica quaternaria della catena appenninica. (issn it 0394-3356, 2009). il notevole cambiamento di stile tettonico che si è verificato nella catena appenninica attorno al pleistocene medio è interpretato come conseguenza dell’accelerazione della placca adriatica, che ha coinvolto nel suo movimento la parte esterna della catena (unità molisesannio, parte orientale della piattaforma laziale-abruzzese, unità romagna-marche-umbria e unità liguridi). la conseguente separazione obliqua tra la parte esterna mobile della catena e quella interna, pressoché immobile, ha generato le deformazioni transtensive sinistre riconosciute nella parte assiale della catena. la spinta dell’adriatico, circa parallela all’asse principale dell’appennino, ha inoltre determinato il forte sollevamento della parte esterna mobile della catena. la compatibilità del complesso quadro deformativo pleistocenico con le implicazioni del modello geodinamico qui proposto e le notevoli difficoltà che le interpretazioni alternative devono affrontare per spiegare tali evidenze sono infine discusse. keywords: quaternary; apennines; geodynamics parole chiave: quaternario; appennini; geodinamica il quaternario italian journal of quaternary sciences 22(1), 2009 97-108 1. introduction it is widely recognized that the deformation style in the apennine belt (fig.1) has considerably changed around the middle pleistocene (e.g. hyppolite et al., 1994; galadini, 1999; bartolini, 1999; 2003; piccardi et al., 2006 and references therein). the southern apennines passed from a dominant compressional to an extensional/transtensional sinistral regime and underwent a marked acceleration of uplift. in the central and northern apennines extensional deformation and uplift has accelerated. moreover, intense volcanic activity built up the roman and campanian magmatic provinces. as most of the tectonic processes which started at that time are still active and control seismic activity, understanding their driving mechanism may be particularly useful. considering the huge amount of information presently available on the quaternary evolution of the apennines, one would expect that the search of the driving mechanism which best accounts for the post-middle pleistocene deformation pattern had led identifying a unique well defined model. instead, in the relevant literature many different and even opposite geodynamic interpretations have been proposed, all claiming to be compatible with the observed features. most often, crustal deformation is explained as an effect of subduction-related driving forces. in particular, several authors suggest that the formation of the tyrrhenian-apennines system has been driven by roll back of the underlying slab (e.g., malinverno & ryan, 1986; royden, 1993). however, this interpretation can hardly account for the most recent evolution of the apennines belt, with particular reference to the marked acceleration of uplift (viti et al., 2006; mantovani et al., 2007a, 2008a). to overcome this problem, various hypotheses have been advanced. one suggests that crustal uplift has occurred in response to the break of the underlying slab (e.g., cinque et al., 1993; westaway, 1993). other hypotheses invoke mantle upwelling to explain the coeval occurrence of uplift and extension in the apennine belt (d’agostino et al., 2001) or the contemporaneous action of the above mechanisms and other driving forces (e.g., meletti et al., 2000). a completely different interpretation, not involving subduction related forces, has been proposed by other authors (e.g., viti et al., 2006; mantovani et al., 2007a, 2008a), who suggest that the post-middle pleistocene evolution of the apennine belt has been considerably influenced by the acceleration of the adriatic plate, in the framework of a tectonic context dominated by the convergence of the surrounding plates. in this work, we argue that the present ambiguity on the geodynamic setting can be considerably mitigated if the major constraints imposed on the model by 98 e. mantovani et al. the available evidence are taken into due account. to this purpose, we discuss the compatibility of the various geodynamic models so far proposed with a large amount of observed tectonic features in the apennines belt and surrounding regions. particular attention is devoted to discussing the mechanism responsible for the recent evolution of the northern apennines. in this regard, we point out the importance of the extensional event that led to the formation of the lower arno basin as discriminant evidence among the various interpretations so far proposed. this is due to the fact that such an event has been generated by a strain regime (nw-se to n-s extension) significantly different from the one that dominated the evolution of the inner part of northern apennines (ne-sw extension). 2. middle pleistocene tectonic reorganization of the apennine belt: major evidence southern apennines since the middle pleistocene, the deformation pattern of this belt sector has undergone a considerable change. the lucanian apennines (fig.1) have been dissected by a system of nw-se sinistral strike-slip faults, associated with compressional and extensional features at restraining and releasing stepovers respectively, and have undergone considerable uplift (e.g., schiattarella et al., 2003; catalano et al., 2004). in the northern sector of the southern apennines, from the matese to irpinia zones (fig.1), normal faults trending from nw-se to e-w, have developed along the inner side of the molise-sannio wedge (e.g., ortolani & torre, 1981; cinque et al., 2000; brozzetti & salvatore, 2005; ascione et al., 2007), forming several troughs, such as the middle volturno, calore and boiano. the above extensional border prosecutes toward south with the nw-se tesa and sabato troughs, up to reaching a complex of e-w trending normal faults in the ofanto zone. in the irpinia sector of such border, both e-w and nw-se active normal faults are recognized. since the middle pleistocene, a large amount of volcanic products has erupted along the inner extensional border of the molise-sannio wedge (e.g., peccerillo, 2003 and references therein), generating the campanian volcanism (fig.1). central apennines this zone, confined to south and north by the sangro-volturno and the olevano-antrodoco thrust fronts respectively (fig.1), has been affected by sinistral transtensional tectonics since the middle pleistocene. this deformation is suggested by several observed features, such as nw-se sinistral and conjugate dextral normal-oblique faults, en-echelon fracture arrays, block rotations about vertical axes (e.g., galadini, 1999; piccardi et al., 1999, 2006) and the focal mechanism of the large avezzano earthquake (1915, m=6.9), which occurfig.1. tectonic sketch of the apennine belt. 1) carbonate platforms 2) thinned continental adriatic domain 3) orogenic units 4) extensional troughs with quaternary activity 5) quaternary volcanic zones 6) outer thrust fronts 7,8,9) main compressional, extensional and transcurrent features. la=latium-abruzzi platform; ml=maiella structural high; cvp=campanian volcanic province; rvp=roman volcanic province. main fault systems: mb=meloria-bientina; oa=olevano-antrodoco; of=ofanto; ol=ottone-levanto; svo=sangro-volturno; tv=tortonavoghera; vv=villavernia-varzi. main troughs with quaternary activity: aq=aquila; bo=boiano; ca=calore; cf=colfiorito; ch=chiana; ct=casentino; fs=foligno-spoleto; fu=fucino; ga=garfagnana; gu=gubbio; lar=lower arno; le=leonessa; lt=lower tiber; lu=lunigiana; mg=magra; mu=mugello; mv=middle volturno; no=norcia; pf=pistoia-firenze; ri=rieti; sa=salto; sb=sabato; su=sulmona; te=tesa; tn=terni; uar=upper arno; us=upper sangro; ut=upper tiber. schema tettonico della catena appenninica. 1) piattaforme carbonatiche 2) dominio adriatico continentale assottigliato 3) unità orogeniche 4) fosse estensionali attive nel quaternario 5) zone vulcaniche quaternarie 6) fronti esterni di sovrascorrimento 7,8,9) principali strutture compressive, distensive e trascorrenti. cvp=provincia vulcanica campana; la=piattaforma laziale-abruzzese; ml= alto strutturale della maiella; rvp=provincia vulcanica romana. principali sistemi di faglie: mb=meloria-bientina; oa=olevano-antrodoco; of=ofanto; ol=ottonelevanto; svo=sangro-volturno; tv=tortona-voghera; vv=villavernia-varzi. fosse ancora attive: aq=aquila; bo=boiano; ca=calore; cf=colfiorito; ch=chiana; ct=casentino; fs=folignospoleto; fu=fucino; ga=garfagnana; gu=gubbio; lar=basso arno; le=leonessa; lt=basso tevere; lu=lunigiana; mg=magra; mu=mugello; mv=medio volturno; no=norcia; pf=pistoiafirenze; ri=rieti; sa=salto; sb=sabato; su=sulmona; te=tesa; tn=terni; uar=alto arno; us=alto sangro; ut=alto tevere. red in the fucino trough (e.g., amoruso et al., 1998). two main nw-se transtensional fault systems can be recognized. the southwestern system encompasses the upper sangro, fucino and salto basins, while the northeastern system crosses the sulmona and aquila troughs (e.g., galadini & galli, 2000; pace et al., 2002). for simplicity, hereafter these two major seismotectonic belts will be recalled as fucino and aquila fault systems. late quaternary transpressional deformation and uplift are recognized in the sangro-volturno and maiella structures, located at the boundary with the southern apennines (e.g., pizzi, 2003; esestime et al., 2006; ascione et al., 2008). in the axial sector of the central apennines, the rapid uplift of the belt has determined the depletion of lakes in most intermontane basins, such as fucino and aquila (fig.1), followed by erosion of fluvio-lacustrine sediments and deposition of alluvial fans (e.g., d’agostino et al., 2001). northern-apennines in the umbria-marche apennines (fig.1), old miocene-pliocene structures, as the olevanoantrodoco thrust front, have been dissected by a system of sinistral transtensional faults since the middle pleistocene (e.g., cello et al., 1997, 1998; piccardi et al., 2006). this fault system, associated with significant seismic activity (e.g., calamita et al., 1994, boncio & lavecchia, 2000), is formed by nw-se normal and oblique faults bounding fluvial-lacustrine basins, such as the leonessa, rieti, terni, norcia, colfiorito, gubbio, upper and lower tiber and foligno-spoleto, connected by n-s sinistral strike-slip faults (e.g., tondi & cello, 2003). such fault system has been interpreted by cello et al. (1997) as a negative flower structure, representing the shallow expression of a n-s trending deep sinistral shear zone, located below the brittle-ductile transition zone. north of the umbria-marche sector (fig.1), roughly ne-sw extension has accelerated since the middle pleistocene in the intermontane troughs, such the chiana, casentino, upper arno, pistoiafirenze, mugello, garfagnana, lunigiana and magra, most of them seismically active (e.g. boncio & lavecchia, 2000; martini et al., 2001; bernini & papani, 2002; briganti et al., 2003; mantovani et al., 2008b). during the quaternary, n-s to nw-se extension has also occurred in the lower arno basin (e.g., bosi, 2004), as suggested by the formation of e-w normal faults, such as the meloria-bientina (cantini et al., 2001). it is worth noting that the roughly n-s extensional axis in that relatively large basin is significantly different from the ne-sw axis that characterized extension throughout the inner part of the northern apennines. seismicity distribution and geomorphologic indicators (e.g., tomaselli et al., 1992; benedetti et al., 2003; meisina & piccio, 2003) suggest that seismotectonic activity occurs in the relatively narrow zone running from the lunigiana basin to the tortona-voghera thrust front (fig.1). such activity could be due to the reactivation of old transpressive faults, such as the villalverniavarzi and ottone-levanto (e.g., cerrina feroni et al., 2004), which would now act as nw-se sinistral decoupling zones between the mobile part of the ligurian 99quaternary geodinamics of ... units and the more inner fixed belt. this hypothesis is consistent with the fact that nw-se sinistral strike-slip faulting, presumably active since the quaternary, has been recognized west of the magra basin (e.g., storti, 1995). acceleration of uplift in the axial sector of the northern apennines since the middle pleistocene is documented by various geomorphological indicators, such as displacement of fluvial terraces and landsurfaces, modification of fluvial drainage and changes in sedimentation rate within intermontane troughs, and by the fact that the ligurian units (which lay at the top of the apenninic thrust sheets) have been completely eroded in a large zone lying between the umbria-marche apennines and the latium-abruzzi platform (e.g., bartolini, 1999, 2003; argnani et al., 2003; bosi, 2004; boccaletti & martelli, 2004). since the middle pleistocene, a large amount of volcanic products erupted along the inner side of the romagna-marche-umbria units (e.g., peccerillo, 2003), building up the roman volcanic province (fig.1). the generation of such volcanism has been interpreted as an effect of transtensional tectonics (e.g., marra, 2001; acocella & funiciello, 2002). some authors (e.g., di bucci & mazzoli, 2002) suggest that the deformation of the northern apennines arc has slowed down up to ceasing around the upper pliocene-lower pleistocene, when the most external thrust front reached its current position. however, as extensively discussed by viti et al. (2006), this hypothesis is not easily reconcilable with seismotectonic evidence, which rather suggests that tectonic activity is sti l l going on in those zones (e.g., boccaletti & martelli, 2004 and references therein). 3. proposed driving mechanism middle pleistocene acceleration of the adriatic plate several features of the quaternary deformation pattern in the central mediterranean region suggest that since the middle pleistocene the adriatic plate has accelerated, after a period of minor mobility in the early pleistocene (viti et al., 2006; mantovani et al, 2007a, 2008a). the time of that acceleration, driven by the convergence of the confining plates (africa, eurasia and the anatolian-aegean system), has been determined by the reactivation of underthrusting of the southeastern adriatic margin beneath the adjacent orogenic belts (mercier et al., 1987; sorel et al., 1992; aliaj, 2006). the supposed adriatic acceleration is consistent with the fact that since the middle pleistocene deformation and uplift at the northern front of that plate, the southern eastern alps and northernmost dinarides, has significantly strengthened. roughly nnw-sse shortening, associated with historical large earthquakes, is recognized at the aviano compressional front shown in figure 2 (e.g., benedetti et al., 2000; galadini et al., 2005). acceleration of uplift is suggested by the changes in sedimentation rate recognized in the venetian plain (e.g., stefani, 2002). neotectonic deformation and seismic activity is also recognized in other peri-adriatic decoupling shear zones: in the northernmost dinarides, at the system of 100 dextral nw-se strike-slip faults, such as the rijeka and idrija, in the central alps, at the schio-vicenza fault system, and in the central dinarides (e.g., markusic & herak, 1999; poljak et al., 2000; sauro & zampieri, 2001). compressional and transpressional seismotectonic activity is recognized at the southeastern border of the adriatic plate (e.g., louvari et al., 2001). in the northern hellenides thrusting accommodates the convergence between the aegean wedge and the southern part of the adriatic plate (e.g., mantovani et al., 2006, 2007a, 2008a). transpressional deformation at the cephalonia fault system (e.g., louvari et al., 1999) accommodates the dextral relative motion between the northern hellenic arc and the southernmost adriatic continental domain. the evidence and arguments that support the motion of the african and adriatic domains shown in figure 2 are described by mantovani et al. (2007b). short-term (geodetic) and longterm (geological) kinematics it is well known (e.g., pollitz, 2003) that the short-term kinematics in tectonic zones, such as the mediterranean region, is controlled by the effects of post-seismic relaxation induced by strong earthquakes wich recently occurred (from years to tens of years, depending on the magnitude and nature of seismic sources) in the surrounding zones. thus, one must be aware that such kinematics, estimated by geodetic measurements, cannot easily be taken as representative of the long-term geological behaviour of plates and crustal wedges. for instance, considerable discrepancies between the strain field implied by the geodetic data given by serpelloni et al . (2005) for the central mediterranean region and the strain regimes inferred from neotectonic information have been pointed out by viti et al. (2006). other macroscopic differences between geodetically determined strain fields and the observed neotectonic deformation have been pointed out for the atlantic zone by merkouriev & de mets (2008). anyway, comparing the most recent geodetic velocities (fig. 3) with the adria kinematics inferred from fig.2 kinematic/tectonic sketch of the adriatic-apennines system, evidencing the apennine units (brown) that move in connection with the adriatic plate, with respect to almost fixed inner belt. aq=aquila fault zone; ela=eastern (mobile) part of the latium abruzzi platform; fu=fucino fault zone; id=idrija fault; lar=lower arno trough; li=ligurian units; lt=lower tiber trough; ml=maiella structural high; ms=molise-sannio units; rj=rijeka fault; rmu=romagna-marche-umbria units; pf=pistoia-firenze trough; sv =schio-vicenza fault system; svo =sangro-volturno thrust front; uar=upper arno trough; ut=upper tiber trough; wla=western (fixed) part of the latium-abruzzi platform. the white-banded strip near rmu indicates the romagna transpressional zone (costa, 2003), possibly decoupling the rmu from the ligurian wedges. blue arrows show the presumed kinematics (scale in the inset) of the adriatic plate and the mobile apennine orogenic wedges with respect to eurasia. large red arrows indicate the presumed pushes of the confining plates (africa and aegean-anatolian system) on the central mediterranean region (e.g., mantovani et al., 2007b, 2008a). symbols and abbreviations as in figure 1. schema cinematico/tettonico del sistema adriatico-appennini, con evidenziate le unità appenniniche (in marrone) che si muovono in connessione con la placca adriatica, rispetto alla catena interna pressoché immobile. aq= faglia dell’aquila; ela= parte orientale (mobile) della piattaforma laziale-abruzzese; fu= faglia del fucino; id= faglia di idrija; lar=fossa del basso arno; li=unità liguri; lt=fossa del basso tevere; ml=alto strutturale della maiella; ms=unità molise-sannio; rj= faglia di rijeka; rmu=unità romagnole-marchigiane-umbre; pf=fossa di pistoia-firenze; sv=sistema di faglie schio-vicenza; svo =fronte di sovrascorrimento sangro-volturno; uar=fossa dell’alto arno; ut=fossa dell’alto tevere; wla=parte occidentale (fissa) della piattaforma laziale-abruzzese. la banda con strisce bianche presso la sigla rmu corrisponde alla zona transpressiva della romagna (costa, 2003), che viene interpretata come un possibile svincolo tra le unità liguri e le rmu. le frecce blu indicano la cinematica presunta, rispetto all’eurasia, della placca adriatica e dei cunei appenninici (scala nel riquadro). le frecce rosse più grandi in africa e nel blocco egeo indicano l’orientazione delle spinte di tali blocchi sulla regione considerata (e.g., mantovani et al., 2007b, 2008a). simboli e sigle come in figura 1. e. mantovani et al. 101 pleistocene deformation (fig. 2) could provide insights into the eventual differences between short and longterm kinematic patterns in the study area. in the southern adriatic, geodetic vectors have a dominant orientation from s-n to ssw-nne, which is similar to the long-term motion trend predicted in figure 2. in this regard, one could point out that the quantification of the effects of the post-seismic relaxation induced by the 1979 strong (m=6.7) montenegro earthquake (viti et al., 2003) provides an increase of about 2 mm/y in the ne direction of present motion rates in the southern adriatic and apennine zones. in the central and northern apennines, the dominant nne to ne ward trend of geodetic vectors is compatible with the extrusion pattern of that belt sector (fig. 2) implied by our evolutionary reconstruction (viti et al., 2006; mantovani et al., 2007a, 2008a). in the southern eastern alps, the dominant northward trend of geodetic vectors is slightly different from the nnw ward motion proposed in figure 2. since this difference is presumably comparable to the uncertainty associated with the motion trend inferred from pleistocene deformation, recognizing whether effects of post seismic relaxation are present in that zone is not easy. another major feature of the geodetic velocities is the significant difference, both concerning amplitude and trend of vectors, between the velocities in axialouter sector of the apennines and those in the inner belt. this evidence, already pointed out by cenni et al. (2008), is compatible with the hypothesis that the axialouter belt (carried by the adriatic plate) moves faster than the inner belt (viti et al., 2006; mantovani et al., 2008a), as discussed in the following section. finally, one could note that some significant differences between the velocities provided by the two different authors in figure 3, especially those of the reggio calabria (tgrc), matera (mate), castel del monte (cadm), villavallelonga (vvlo), roma (ingr) and aquila (aqui) stations, cannot easily be explained, even if one takes into account that the absolute velocities are related with different reference models (itrf2000 and itrf2005) and that different eurasian euler poles have been adopted to derive residual velocities. geodynamics of the southern and central apennines the connection between the acceleration of the adriatic plate and the tectonic reorganization of the apennine belt is due to the fact that since the middle pleistocene the outer sectors of the apennines have been carried by the adriatic plate (viti et al., 2006; mantovani et al., 2008a). the consequent oblique separation between such mobile orogenic units and the inner almost fixed belt (fig.2) has induced transtensional deformation in the axial belt, while the mobile units, under the push of the adriatic, has undergone a significant acceleration of uplift. in the southern apennines, the mobile belt is mainly formed by the molise-sannio (ms) wedge. the extensional decoupling zone between this wedge and the inner belt is formed by a system of normal faults running from the matese to the irpinia zones, as described earlier (figs.1 and 2). the transmission of compressional stress from the ms wedge to the latium-abruzzi (la) platform involves oblique thrusting and strong seismicity at the border between those two blocks, as recognized in the maiella and sangro-volturno zones (fig.2). the fact that the push of the ms wedge is mainly applied to the eastern sector of the latiumabruzzi platform (ela) has induced sinistral shear stress in that platform, with the consequent formation of nw-se transtensional fault systems, such as the aquila and fucino. the decoupling between the adriatic-apennine mobile system and the extruding calabrian wedge is accommodated by nw-se sinistral strike-slip faults recognized in the lucanian apennines (e.g., viti et al., 2006; mantovani et al., 2008a). geodynamics of the northern apennines the recent deformation pattern of the northern apennine arc may be plausibly explained as an effect of the indentation of ela (viti et al., 2006; mantovani et al., 2008a,b). a tentative reconstruction of the proposed driving mechanism and tectonic evolution is shown in figure 4. the most mobile sector of the above arc is the romagna-marche-umbria (rmu) wedge. under the fig.3 residual velocities with respect to eurasia deduced by continuous gps measurements. black arrows indicate the velocities provided by devoti et al. (2008), with absolute eurasia euler pole at 55.85°n, 95.72°w, ω=0.266 °/my. empty arrows indicate the vectors provided by serpelloni et al. (2007), with eurasia euler pole at 52.92°n, 105.66°w, ω =0.246 °/my. velocità residue rispetto all’eurasia ottenute da misure gps continue. le frecce nere indicano le velocità prese da devoti et al. (2008), con il polo euleriano dell’eurasia situato a 55.85°n, 95.72°w, ω =0.266 °/my. le frecce vuote indicano le velocità prese da serpelloni et al. (2007), con polo euleriano dell’eurasia posto a 52.92°n, 105.66°w, ω =0.246 °/my. quaternary geodinamics of ... 102 push of ela, this arc has undergone outward bending and extrusion, accommodated by folding and thrusting at the outer front and extension in the inner side, both associated with high seismic activity (e.g., viti et al., 2006; cenni et al., 2008; mantovani et al., 2008b). the information provided by seismic soundings (finetti et al., 2005) indicates that the extruding orogenic wedge is formed by the uppermost crustal units overlying the triassic evaporitic layer, which acts as decoupling zone. this wedge moves eastward sliding over the main tiber fault (e.g., boncio et al., 2000; finetti et al., 2005; cenni et al., 2008). the extensional separation between the migrating wedge and the inner belt has formed the upper tiber trough (fig. 4). on the other side, the convergence of that wedge with the adriatic domain has generated the compressional features recognized at the outer apennine thrust front (e.g., lavecchia et al., 2003a). it must be pointed out that the lateral escape of the above wedge has occurred while the adriatic lithosphere, driven by the convergence of the confining plates (africa, eurasia and aegean), was underthrusting the apennine belt (cenni et al., 2008). support to the hypothesis that the deformation of northern apennines is connected with the indentation of ela is provided by the distribution of major earthquakes in these regions. for instance, a discussion about the influence that the strongest historical decoupling earthquakes in the la fault systems (aquila and fucino) may have had on the seismic activity of the northern apennines is given by mantovani et al. (2008b). the fact that the roman volcanic province (fig.4) is located along the inner boundary of the rmu wedge corroborates the hypothesis that such volcanism was connected with the transtensional regime that developed in the wake of that migrating wedge (e.g., tamburelli et al., 2000; viti et al., 2006). while extruding outward, the rmu wedge has transmitted stress to the ligurian units and adjacent structures, causing their counterclockwise rotation and nw ward translation. this kinematics can account for the compressional deformation recognized at the padanian margin of the above units and the extensional seismotectonic activity observed at their inner boundary (pistoia-firenze, garfagnana and lunigiana troughs), described in section 2. the decoupling of the ligurian wedge from the westernmost part of the apennines is accommodated by a sinistral transpressional fault system running from the lunigiana trough to the tortona-voghera thrust front (fig.4). seismic soundings and spatial distribution of earthquakes in the romagna apennines might indicate the presence of a roughly n-s transpressional decoupling zone between the rmu and ligurian wedges (costa, 2003), as tentatifig.4 tentative reconstruction of the late pliocene configuration of major structural units in the central and northern apennines (a), compared with the present setting (b). comments in the text. 1) ligurian units 2) southern apennine pelagic units 3) carbonate platforms 4) northern apennine internal units 5) northern apennine external units 6) laga turbidites and similar units. ela=eastern (mobile) part of the latium-abruzzi platform (la); li=ligurian units; lar=lower arno trough; ms=molise-sannio units; rmu=romagna-marche-umbria units; rvp =roman volcanic province; wla=western (fixed) part of the latium-abruzzi platform. the distribution of structural units in b) is taken from the tectonic map of italy (funiciello et al., 1981). other symbols and abbreviations as in figure 1. ricostruzione della configurazione delle principali unità strutturali nel tardo pliocene (a), confrontata con l’assetto attuale (b), preso dalla carta tettonica d’italia (funiciello et al., 1981). commenti nel testo. 1) unità liguri 2) unità pelagiche dell’appennino meridionale 3) piattaforme carbonatiche 4) unità interne dell’appenino settentrionale 5) unità esterne dell’appennino settentrionale 6) unità torbiditiche della laga ed affini. ela=parte orientale (mobile) della piattaforma laziale-abruzzese; ms=unità molise-sannio; la=piattaforma laziale-abruzzese; rmu=unità romagnole-marchigiane-umbre; rvp=provincia vulcanica romana; wla=parte occidentale (fissa) della piattaforma laziale-abruzzese. altri simboli e sigle come in figura 1. e. mantovani et al. vely sketched in figure 2. the divergence between the migrating ligurian wedge, encompassing the apuane metamorphic complex, and the almost fixed southern tuscany zone, might explain the n-s to nw-se extension that formed the lower arno trough (fig. 4). it must be pointed out that the occurrence of such tectonic event, being characterized by a deformation style rather different from the one that dominated the formation of the inner side of the northern apennines (ne-sw extension), provides a very important constraint on the driving mechanism of this belt sector, as discussed in the next section. 4. alternative geodynamic interpretations various hypotheses have been advanced about the geodynamic setting responsible for the middle pleistocene tectonic reorganization of the apennines. in the following, we make some remarks about the plausibility of the most cited interpretations and their consistency with the observed deformation pattern. slab detachment this hypothesis suggests that the acceleration of uplift in the apennines since the middle pleistocene has occurred as a sort of lithospheric rebound, in response to the break of the underlying slab (e.g., cinque et al., 1993; westaway, 1993; bertotti et al., 1997). in our opinion, this interpretation presents major weak points. in the northern apennines, tomographic investigations delineate a continuous westward dipping slab down to several hundreds of km (e.g., piromallo & morelli, 2003), which is evidently incompatible with the slab detachment model. alternatively, the structural images provided by crop deep seismic soundings (finetti et al., 2005) exclude the presence of a welldeveloped slab beneath the northern apennines and rather suggest that the underlying lithospheric body is formed by relatively short continental slivers only reaching a moderate depth (less than 100 km). this reconstruction is compatible with the distribution of subcrustal earthquakes in the northern apennines, in particular with the lack of events deeper than 70-80 km (e.g., chiarabba et al., 2005), and with the recognized continental nature of the adriatic lithosphere that lay in front of the advancing arc since the miocene (e.g., serri et al., 1993). even considering this alternative view of the deep structural setting, the slab detachment model cannot be invoked as the driving mechanism of crustal uplift in the northern apennines. in the southern apennines, some tomographic investigations suggest the presence of a gap in the subducted lithosphere (e.g., lucente & speranza, 2001). thus, the slab detachment model could be applied to that apennine segment. however, other considerations do not support the reliability of that interpretation: the feasibility of the proposed physical mechanism is not demonstrated. for instance, some numerical simulations of that phenomenon (e.g., giunchi et al., 1996) predict subsidence instead of uplift of the lithosphere overlying the broken slab. the slab detachment model could account for the timing of the observed acceleration of uplift in the apennines only if the presumed break had occurred around the middle pleistocene. however, there is no evidence of such timing. the strain regimes recognized in the matese-irpinia and lucanian sectors of the southern apennines are rather different, as mentioned earlier. explaining why two adjacent crustal structures have reacted in such different ways to the detachment of the underlying slab is not easy. one should also consider that in the calabrian arc, where strong quaternary uplift is clearly documented (e.g., westaway, 1993), any significant interruption of the slab is ruled out by seismic tomography (e.g., piromallo & morelli, 2003), deep seismic soundings (finetti, 2005) and studies of seismic wave propagation from deep earthquakes (mele, 1998). mantle upwelling some authors (e.g., d’agostino et al., 2001; lavecchia et al., 2003b) suggest that this phenomenon is taking place under the apennines belt and that it could be responsible for the observed quaternary deformation, in particular volcanism and coeval occurrence of uplift and crustal extension. d’agostino et al. (2001) even advance the hypothesis that the spreading induced by the mantle-supported uplift in the apennines forces the adriatic lithosphere to move ne ward with respect to eurasia. in the following, we argue that the occurrence of active rifting beneath the apennines belt cannot easily be reconciled with major evidence. one can hardly understand why mantle upwelling would have caused the ne ward displacement of the adriatic block, whereas the domains lying on the other side of the presumed rifting process (tyrrhenian region and corsica-sardinia block) have not undergone any westward migration. in our opinion, this strong asymmetry in the effect of the presumed rifting is a major problem for the mantle upwelling model, especially if one considers that pushing away a relatively small block suck as corsica-sardinia would have been much easier than displacing the large adria plate. until a plausible explanation is found for this difficulty, mantle upwelling can hardly be claimed to be a feasible driving mechanism. time space distribution and petrological features of quaternary volcanism in the apennine belt is considerably different from that observed in active rifting zones (e.g., peccerillo, 2003, 2006). in particular, one should explain why volcanic activity has mainly developed in two limited zones of the inner belt (figs. 1 and 4). mantle convection and related rifting appear to be large-scale phenomena that involve wide spaces (much more than the central apennines) and requires millions of years to fully develop (e.g., ziegler & cloetingh, 2004). thus, one could wonder why such processes had a relatively fast development around the middle pleistocene and such a limited spatial effect. the occurrence of some peculiar tectonic events, such as for instance the formation of the lower arno basin (fig. 4), can hardly be interpreted as an effect of active rifting under the belt. considering that in the lucanian apennines, uplift is 103quaternary geodinamics of ... associated with strike-slip tectonic, instead of crustal extension, and that an even more complex tectonic pattern is recognized in calabria (finetti, 2005), one could wonder why the presumed effects of active rift ing only occur along a l imited sector of the apennines. in this regard, one should also explain other important differences in the tectonic evolution of the apennines, for instance the fact that in the quaternary thrusting stopped in the southern apennines and continued to develop in the outer belt of the northern apennines. the dynamic/kinematic scheme proposed by d’agostino et al. (2001) requires a zone of decoupling between the adriatic (moving ne ward in the above view) and africa (moving nnw ward in the nuvel1 kinematic model), which is not supported by any significant evidence. a detailed discussion about this problem is given by babbucci et al. (2004) and mantovani et al. (2007b). multiple driving mechanisms some authors have tried to overcome the difficulties of the above interpretations by invoking the contemporaneous action of more than one driving mechanism. a significant example of this kind of interpretation is the one proposed by meletti et al. (2000), who suggest that the quaternary deformation pattern recognized in the tyrrhenian-apennines system may be explained as an effect of a complex of driving mechanisms. in that view, the adriatic counterclockwise rotation would cause compressional deformation in the southern eastern alps and northern dinarides and extensional tectonics in the southern apennines. slab roll back would be responsible for the development of arc-back arc tectonics (arc migration, trench retreat and back arc opening) in the northern apennines and calabrian arc. slab detachment is invoked to explain the uplift of the apennine belt, while pushing of asthenospheric wedges would be responsible for the compressional deformation observed at the external fronts of the northern apennines and calabrian arcs. the africa-eurasia convergence would explain the compressional deformation observed along the maghrebian chain in northern sicily and the adjacent tyrrhenian area. in general, invoking so many driving mechanisms for a relatively l imited region as the central mediterranean appears to be mainly speculative. to check the plausibility of that model one should compare the observed features with the deformation resulting from the combined effects of all presumed driving mechanisms. conclusions around the middle pleistocene, the resuming of the underthrusting process at the south eastern adriatic collisional border has allowed the adriatic plate to accelerate its motion towards eurasia. that tectonic event has deeply influenced the deformation pattern of the apennine belt, since the above acceleration has also involved the outer part of the apennines (molisesannio, eastern latium-abruzzi platform, romagnamarche-umbria and ligurian units), causing its oblique separation from the inner belt, almost fixed. such divergence has been accommodated by transtensional deformation in the axial part of the chain, while the beltparallel push of the adriatic has caused acceleration of uplift in the mobile units. the compatibility of the proposed geodynamic interpretation with the quaternary deformation pattern in the apennine belt, with particular regard to the northern apennines, is discussed. on the other hand, it is argued that the implications of the alternative driving mechanisms so far proposed can hardly be reconciled with the available evidence. references aliaj sh. (2006) the albanian orogen: convergence zone between eurasia and the adria microplate. in: pinter, n. et al. (eds.), “the adria microplate: gps geodesy”, tectonics and hazards, springer, pp. 133-149. acocella v. & funiciello r. (2002) transverse structures and volcanic activity along the tyrrhenian margin of central italy. boll. soc. geol. it., vol. spec. 1, pp. 739-747. amoruso a., crescentini l. & scarpa r. (1998) inversion of source parameters from nearand farfield observations: an application to the 1915 fucino earthquake, central apennines, italy. j. geophys. res., 103, pp. 29989-29999. argnani a., barbacini g., bernini m., camurri f., ghielmi m., papani g., rizzini f., rogledi s. & torelli l. (2003) gravity tectonics driven by quaternary uplift in the northern apennines: insights from the la spezia-reggio emilia geo-transect. quaternary int., 101-102, pp. 13-26. ascione a., caiazzo c. & cinque a. (2007) recent faulting in southern apennines (italy): geomorphic evidence, spatial distribution and implications for rates of activity. boll. soc. geol. it., 126, pp. 293305. ascione a., cinque a., miccadei e. & villani f. (2008) the plio-quaternary uplift of the apennines chain: new data from the analysis of topography and river valleys in central italy. geomorphology, 102, pp. 105-118. babbucci d., tamburelli c., viti m., mantovani e., albarello d., d’onza f., cenni n. & mugnaioli e. (2004) relative motion of the adriatic with respect to the confining plates: seismological and geodetic constraints. geophys. j. int., 159, pp. 765-775. bartolini c. (1999) an overview of pliocene to present-day uplift and denudation rates in the northern apennine. in: smith, b.j., whalley, w.b., warke, p.a. (eds.), uplift, erosion and stability: perspectives on long-term landscape development. geol. soc. london, spec. publ. 162, pp. 1-7. bartolini c. (2003) when did the northern apennine become a mountain chain? quaternary int., 101102, pp. 75-80. benedetti l., tapponnier p., king g.c.p., meyer b. & manighetti i. (2000) growth folding and active thrusting in the montello region, veneto, northern italy. j. geophys. res., 105, pp. 739-766. 104 e. mantovani et al. benedetti l., tapponnier p., gaudemer y., manighetti i. & van der woerd j. (2003) geomorphic evidence for an emergent active thrust along the po plain: the broni-stradella fault. j. geophys. res., 108, 2238, etg6, pp.1-14. bernini m. & papani g. (2002) la distensione della fossa tettonica alla lunigiana nord-occidentale (con carta geologica alla scala 1:50.000). boll. soc. geol. it., 121, pp. 313-341. bertotti g., capozzi r. & picotti v. (1997) extension controls quaternary tectonics, geomorphology, and sedimentation of the n-apennines foothills and adjacent po plain (italy). tectonophysics, 282, 291-301. boccaletti m. & martelli l. (coords.) (2004) carta sismo-tettonica della regione emilia-romagna, scala 1:250.000 e note i l lustrative. selca, firenze. boncio p. & lavecchia g. (2000) a structural model for active extension in central italy. j geodynamics, 29, pp. 233-244. boncio p., brozzetti f. & lavecchia g. (2000) architecture and seismotectonics of a regional low-angle normal fault zone in central italy. tectonics, 19, pp. 1038-1055. bosi c. (ed.) (2004) quaternary. special volume of the ital ian geological society for the igc 32, florence, pp. 161-188. briganti r., ciufegni a., coli m., polimeni s. & pranzini g. (2003) underground florence: plioquaternary geological evolution of the florence area. boll. soc. geol. it., 12, pp. 435-445. brozzetti f. & salvatore a. (2005) quaternary extensional fault-systems from northern and southern apennines: similarities and differences. rend. soc. geol. it.-nuova serie, 1, pp. 58-60. calamita f., coltorti m., farabollini, p. & pizzi a. (1994) le faglie normali quaternarie nella dorsale appenninica umbro-marchigiana: proposta di un modello di tettonica di inversione. studi geol. camerti, vol. spec. crop 18, pp. 211-225. cantini p, testa g, zanchetta g. & cavallini r. (2001) the plio-pleistocene evolution of extensional tectonics in northern tuscany, as constrained by new gravimetric data from the montecarlo basin (lower arno valley, italy). tectonophysics, 330, pp. 2543. catalano s., monaco c. & tortorici l. (2004) neogene-quaternary tectonic evolution of the southern apennines. tectonics, 23, tc2003, pp. 1-19. cello g., mazzoli s., tondi e. & turco e. (1997) active tectonics in the central apennines and possible implications for seismic hazard analysis in peninsular italy. tectonophysics, 272, pp. 43-68. cello g., mazzoli s. & tondi e. (1998) the crustal fault structure responsible for the 1703 earthquake sequenze of central italy. j. geodynamics, 26, pp. 443-460. cenni n., viti m., baldi p., mantovani e., ferrini m., d’intinosante v., babbucci d. & albarello d. (2008) short-term (geodetic) and long-term (geological) velocity fields in the northern apennines. boll. soc. geol. it., 127, pp. 93-104. cerrina feroni a, ottria g & ellero a. (2004) the northern apennine, italy: geological structure and transpressive evolution. special volume of the ital ian geological society for the igc 32, florence, pp. 15-32. chiarabba c., jovane l. & di stefano r. (2005) a new view of italian seismicity using 20 years of instrumental recordings. tectonophysics, 395, pp. 251268. cinque a., patacca e., scandone p. & tozzi m. (1993) quaternary kinematic evolution of the southern apennines. relationships between surface geological features and deep lithospheric structures. ann. geofis., 36, pp. 249-260. cinque a., ascione a. & caiazzo c. (2000) distribuzione spazio-temporale e caratterizzazione della fagliazione quaternaria in appennino meridionale. in: galadini f., meletti c. and rebez a. (eds.), ricerche del gndt nel campo della pericolosità sismica (1996-1999), special publication of cnrgndt, gruppo nazionale per la difesa dai terremoti, roma, pp. 203-218. costa m. (2003) the buried, apenninic arcs of the po plain and northern adriatic sea (italy): a new model. boll. soc. geol. it., 122, pp. 3-23. d’agostino n., jackson j.a., dramis f. & funiciello r. (2001) interactions between mantle upwelling, drainage evolution and active normal faulting: an example from the central apennines (italy). geophys. j. int., 147, pp. 475-479. devoti r., riguzzi f., cuffaro m., doglioni c. (2008) new gps constraints on the kinematics of the apennines subduction. earth planet. sci. lett., 273, pp.163-174. di bucci d. and mazzoli s. (2002) active tectonics of the northern apennines and adria geodynamics: new data and a discussion. j. geodynamics, 34, pp. 687-707. esestime p., d’arcangelo s., paltrinieri w. & calamita f. (2006) strutture transpressive della catena apula sepolta (appennino meridionale, settore campano-molisano). rend. soc. geol. it. nuova serie, 2, pp. 135-137. finetti i.r. (2005) the calabrian arc and subducting ionian slab from new crop seismic data. in: finetti, i.r. (ed.), deep seismic exploration of the central mediterranean and italy, crop project. elsevier, 17, pp. 393-412. finetti i.r., boccaletti m., bonini m., del ben a., pipan m., prizzon a. & sani f. (2005) lithospheric tectono-stratigraphic setting of the ligurian seanorthern apennines-adriatic foreland from integrated crop seismic data. in: finetti, i.r. (ed.), deep seismic exploration of the central mediterranean and italy, crop project, elsevier, 8, pp. 119-158. funiciello r., parotto m & praturlon a. (1981) carta tettonica d’italia, scala 1:1500000. c.n.r. progetto finalizzato geodinamica, pubbl. n. 269, grafica editoriale cartografica, roma. galadini f. (1999) pleistocene change in the central apennine fault kinematics, a key to decipher active tectonics in central italy. tectonics, 18, pp. 877-894. galadini f. & galli p. (2000) active tectonics in the central apennines (italy) – input data for seismic 105quaternary geodinamics of ... hazard assessment. natural hazards, 22, pp. 225270. galadini f., poli m.e. & zanferrari a. (2005) seismogenic sources potentially responsible for earthquakes with m ≥ 6 in the eastern southern alps (thiene-udine sector, ne italy). geophys. j. int., 161, pp. 739-762. giunchi c., sabadini r., boschi e. & gasperini p. (1996) dynamic models of subduction: geophysical and geological evidence in the tyrrhenian sea. geophys. j. int., 126, pp. 555-578. hippolyte j.c., angelier j. & barrier e. (1994) a major geodynamic change revealed by quaternary stress patterns in the southern apennines (italy). tectonophysics, 230, pp. 199-210. lavecchia g., boncio p. & creati n. (2003a) a lithospheric-scale seismogenic thrust in central italy. j. geodynamics, 36, pp. 79-94. lavecchia g, boncio p, creati n & brozzetti f. (2003b) some aspects of the italian geology not fitting with a subduction scenario. j. virtual explorer, 10, pp. 1-14. louvari e., kiratzi a.a. & papazachos b.c. (1999) the cephalonia transform fault and its extension to western lefkada island (greece). tectonophysics, 308, pp. 223-236. louvari e., kiratzi a.a., papazachos b.c. & katzidimitriou p. (2001) fault-plane solutions determined by waveform modelling confirm tectonic collision in the eastern adriatic. pure appl. geophys., 158, pp. 1613-1637. lucente f.p. & speranza f. (2001) belt bending driven by lateral bending of subducting lithospheric slab: geophysical evidences from the northern apennines (italy). tectonophysics, 337, pp. 53-64. malinverno a. & ryan w.b.f. (1986) extension in the tyrrhenian sea and shortening in the apennines as result of arc migration driven by sinking of the lithosphere. tectonics, 5, pp. 227-245. mantovani e., viti m., babbucci d., tamburelli c. & albarello d. (2006) geodynamic connection between the indentation of arabia and the neogene tectonics of the central-eastern mediterranean region. in: dilek y., pavlides s. (eds.), post-collisional tectonics and magmatism in the mediterranean region and asia. geological society of america, special volume, 490, pp. 1549. mantovani e., viti m., babbucci d. & tamburelli c. (2007a) major evidence on the driving mechanism of the tyrrhenian-apennines trench-arc-back arc system from crop seismic data. boll. soc. geol. it., 126, pp. 459-471. mantovani e., viti m., babbucci d., albarello d. (2007b) nubia-eurasia kinematics: an alternative interpretation from mediterranean and north atlantic evidence. ann. geophys., 50, 311-336. mantovani e., babbucci d., tamburelli c. & viti m. (2008a) a review on the driving mechanism of the tyrrhenian-apennines system: implications for the present seismotectonic setting in the centralnorthern apennines. tectonophysics, in press (available online at http://dx.doi.org/10.1016/j. tecto.2008.10.032 tecto124399). mantovani e., viti m., babbucci d., albarello d., cenni n. & vannucchi a., (2008b) long-term earthquake triggering in the southern and northern apennines. j. seismol., in press (available online at http://dx.doi.org/10.1007/s10950-008-9141-z). markušić s. & herak m. (1999) seismic zoning of croatia. natural hazards, 18, pp. 269-285. marra f. (2001) strike-slip faulting and block rotation: a possible triggering mechanism for lava flows in the alban hills? j. struct. geol., 23, pp. 127–141. martini i.p., sagri m. & colella a. (2001) neogenequaternary basins of the inner apennines and calabrian arc. in: vai g.b., martini i.p. (eds) anatomy of an orogen: the apennines and adjacent mediterranean basins. kluwer academic publishing, london, pp. 375-400. meisina c. & piccio a. (2003) river dynamics and slope processes along a sector of the villalvernia-varzi line (northern italy). quaternary int., 101-102, pp. 179-190. mele g. (1998) high-frequency wave propagation from mantle earthquakes in the tyrrhenian sea: new constraints for the geometry of the south tyrrhenian subduction zone. geophys. res. lett., 25, pp. 2877-2880. meletti c., patacca e. & scandone p. (2000) construction of a seismotectonic model: the case of italy. pure appl. geophys., 157, pp. 11-35. mercier j., sorel d. & simeakis k. (1987) changes in the state of stress in the overriding plate of a subduction zone: the aegean arc from the pliocene to the present. ann. tectonicae, 1, pp. 20-39. merkouriev s. & demets c. (2008) a high-resolution model for eurasia–north america plate kinematics since 20 ma. geophys. j. int., 173, pp. 10641083. ortolani f. & torre m. (1981) guida all’escursione nell’area interessata dal terremoto del 23.11.1980. rend. soc. geol. it., 4, pp. 173-214. pace b., boncio p. & lavecchia g. (2002) the 1984 abruzzo earthquake (italy): an example of seismogenic process controlled by interaction between differently oriented synkinematic faults. tectonophysics, 350, pp. 237-254. peccerillo a. (2003) plio-quaternary magmatism in italy. episodes, 26, pp. 222-226. peccerillo a. (2006) carbonatites vs. carbonated rocks in central italy. a reply to comments by bell and kjarsgaard. period. mineral., 75, pp. 93-100. piccardi l., gaudemer y., tapponnier p. & boccaletti m. (1999) active oblique extension in the central apennines (italy): evidence from the fucino region. geophys. j. int., 139, pp. 499-530. piccardi l., tondi g. & cello g. (2006) geo-structural evidence for active oblique extension in southcentral italy. in: pinter n. et al., (eds.) the adria microplate: gps geodesy, tectonics and hazard. springer, pp. 95-108. piromallo c. & morelli a. (2003) p wave tomography of the mantle under the alpine-mediterranean area. j. geophys. res., 108, 2065, ese1, pp. 123. pizzi a. (2003) plio-quaternary uplift rates in the outer zone of the central apennines fold-and-thrust belt, italy. quaternary int., 101-102, pp. 229-237. poljak m., zivcic m. & zupancic p. (2000) the seismo106 e. mantovani et al. tectonic characteristics of slovenia. pure appl. geophys., 157, pp. 37-55. pollitz f.f. (2003) the relationship between the instantaneous velocity field and the rate of moment release in the lithosphere. geophys. j. int., 153, pp. 595-608. royden l.h. (1993) evolution of retreating subduction boundaries formed during continental collision. tectonics, 12, pp. 629-638. schiattarella m., di leo p., beneduce p. & giano s.i. (2003) quaternary uplift vs tectonic loading: a case study from the lucanian apennine, southern italy. quaternary int., 101-102, pp. 239-251. sauro u. & zampieri d. (2001) evidence of surface faulting and surface rupture in the fore-alps of veneto and trentino (ne italy). geomorphology, 40, pp. 169-184. serpelloni e., anzidei m., baldi p., casula g. & galvani g. (2005) crustal velocity and strain-rate fields in italy and surrounding regions: new results from the analysis of permanent and non-permanent gps networks. geophys. j. int., 161, 861-880. serpelloni e., vannucci g., pondrelli s., argnani a., casula g., anzidei m., baldi p.& gasperini p. (2007) kinematics of the western africa-eurasia plate boundary from focal mechanisms and gps data. geophys. j. int., 169, pp. 1180–1200. serri g., f. innocenti & p. manetti (1993) geochemical and petrological evidence of subduction of delamination adriatic continental lithosphere in the genesis of the neogene-quaternary magmatism of central italy. tectonophysics, 223, pp. 117-147. sorel d., bizon g., aliaj s. & hasani l. (1992) calage stratigraphique de l'age et de la durée des phases compressives des hellénides externes (grèce nord-occidentale et albanie) du miocène à l'actuel. bull. soc. geol. france, 163, pp. 447454. stefani c. (2002) variation in terrigenous supplies in the upper pliocene to recent deposits of the venice area. sedim. geol., 153, pp. 43-55. storti f. (1995) tectonics of the punta bianca promontory: insights for the evolution of the northern apennines-northern tyrrhenian sea basin. tectonics, 14, pp. 832-847. tamburelli c., babbucci d. & mantovani e. (2000) geodynamic implications of subduction related magmatism: insights from the tyrrhenian– apennines region. j. volc.geoth.res., 104, pp. 33-43. tomaselli a., pastore s., augliera p. & eva c. (1992) sismicità dell’appennino nord-occidentale. studi geologici camerti, vol. spec. 2, crop 1-1a, pp. 43-50. tondi e. & cello g. (2003) spatiotemporal evolution of the central apennines fault system (italy). j. geodynamics, 36, pp. 113-128. viti m., d’onza f., mantovani e., albarello d. & cenni n. (2003) post-seismic relaxation and earthquake triggering in the southern adriatic region. geophys. j. int., 153, pp. 645-657. viti m., mantovani e. babbucci d. & tamburelli c. (2006) quaternary geodynamics and deformation pattern in the southern apennines: implications for seismic activity. boll. soc. geol. it., 125, pp. 273291. westaway r. (1993) quaternary uplift in southern italy. j. geophys. res., 98, pp. 21741-21772. ziegler p.a. & cloetingh s. 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(salento, south italy) assunta d’alessandro, francesco loiacono dipartimento di geologia e geofisica, università di bari corresponding author: a. d’alessandro <tina@geo.uniba.it> abstract: d’alessandro a. & loiacono f., palaeontological and sedimentologic criteria for high resolution environmental analysis: the pleistocene succession at torre ovo (salento, south italy). (it issn 0394-3356, 2010). the about 15 m thick middle and upper pleistocene succession outcropping near torre ovo (south of taranto, salento), contains diverse assemblages of body and trace fossils. the assemblages are sensitive indicator of environmental parameters and allow to recognize stratigraphic key surfaces and infer sedimentation dynamics. the lower unit (1) is a marine faintly layered muddy fine sand, that may be attributable to the middle pleistocene. the following unit (2) is a marine calcarenite, possibly deposited during m.i.s. 5.5. blocks of algal calcarenite included in the basal transgressive lag are reworked from inferred m.i.s.7 deposits. the succession ends with a continental unit subdivided into sub-units 3a and 3b, which are late pleistocene or holocene in age. unit (1) includes rare trace fossils in paramoudra-preservation. during a phase of subaerial exposure in a hot, semi-arid climate, the deposit was subjected to intense vadose diagenesis. unit (2) can be subdivided into four sub-units: 2a and 2b represent the trangressive systems tract, 2c records the condensed maximum flooding zone, and 2d the regressive systems tract. greyish calcarenite (3a), laps onto the basal part of unit 2. its upper part includes pebbles and blocks of sub-unit 2d. the sediment is pervasively bioturbated (camborygma shafts). this ichnogenus is indicative of a terrestrial environment, firm substrate and is influenced by the ground water level. sub-unit 3b, partly coeval to sub-unit 3a, is a reddish terrigenous conglomerate including few camborygma shafts in rare sand lenses. tentatively, the deposit has been attributed to m.i.s 3. riassunto: d’alessandro a. & loiacono f., criteri paleontologici e sedimentologici per un’analisi ambientale ad alta risoluzione: la successione pleistocenica di torre ovo (italia meridionale, salento). (it issn 0394-3356, 2010). lungo la costa ionica del salento, nell’area di torre ovo (a sud di taranto), affiora una successione, attribuibile al pleistocene medio e superiore, di spessore variabile (al massimo circa 15 metri) che contiene diverse associazioni di fossili in senso stretto ed icnofossili. le associazioni sono indicatori di parametri ambientali e permettono di riconoscere importanti superfici stratigrafiche nonché di dedurre le dinamiche deposizionali della sedimentazione. la successione è divisibile in tre unità. l’unità inferiore (1), composta da una alternanza di straterelli siltosi fangosi e di livelletti sabbiosi più sottili (generalmente inferiori a 2 cm), include rare tracce fossili con conservazione paramoudra e disperse impronte esterne di nassariidi nel sedimento più fangoso. può essere correlata a depositi affioranti in prossimità di taranto ed attribuiti al pleistocene medio. la sovrastante unità (2) è una calcarenite marina, i cui sedimenti furono depositati probabilmente durante mis 5.5. l’unità 2 è stata suddivisa in quattro sotto-unità: 2a e 2b rappresentano il system tract trasgressivo, 2c ricorda la zona condensata del maximum flooding, e 2d il system tract regressivo. la successione termina con una unità continentale divisibile nelle sotto-unità 3a e 3b del pleistocene superiore o dell’olocene. la calcarenite grigiastra (3a) si addossa sulla parte basale della unità 2. la sua parte superiore include ciottoli e blocchi della sotto-unità 2d. il sedimento è pervasivamente bioturbato (camborygma shafts).questo icnogenere è indicativo di ambienti terrestri, substrato compatto ed è influenzato dal ground water level. la sotto-unità 3b, in parte coeva alla sotto-unità 3a, è un conglomerato terroso che include lenti sabbiose contenenti rare camborygma. tentativamente, il deposito è stato attribuito a m.i.s. 3. key words: environmental changes, paramoudra, camborygma, quaternary. parole-chiave: cambiamenti ambientali, paramoudra, camborygma, quaternario. il quaternario italian journal of quaternary sciences 23(1), 2010 91-102 introduction marine terrace deposits outcropping along the coastal area of western apulia have been repeatedly investigated. geomorphologic and stratigraphic descriptions and chronologic reconstruction of the deposits near taranto were provided by different authors (i.e. dai pra & hearty, 1992; belluomini & alii, 2002; caputo, 2007), but the age of the coastal deposits, their palaeogeography and local uplift history have yet to be elaborated. the study area (fig.1) was chosen for the presence of different sedimentary bodies and trace fossil assemblages that may allow us to infer sequences and depositional environments. the primary purposes of this study are thus (1) to examine biotic changes and interpret their probable causes, and (2) to infer from ichnofossil assemblages some factors biasing the depositional environments. geological setting the ionian coast of salento peninsula is located on the eastern flank of the taranto valley, considered to be the present foredeep area of the southern apennines chain-bradanic trough-apulian foreland 92 a. d’alessandro & f. loiacono system (pescatore & senatore, 1986). the apulian unit is characterized by mesozoic limestones unconformably covered by pliocene and quaternary deposits more than 500 m thick in the gallipoli basin (well lieta 1, agip, 1977) (fig. 1). the pliocene deposits are represented by a calcarenite unit containing fossils that belong to the early mediterranean pliocene molluscan units (mpmu1) (d’alessandro et alii, 2004), i.e. to a tropical unit that disappears about 3.0 ma ago (monegatti & raffi, 2001, 2007). this unit is transgressed by a lower pleistocene calcarenite with boreal immigrants, or by greyish muds attributed to the “argil le subappennine” formation (upper pliocene-middle pleistocene). from the middle pleistocene onwards the regional uplift and glacio-eustatic sea-level changes produced several marine terraces, some characterized by calcarenite or mixed deposits or by coastal calcarenitic/calciruditic bodies (communication of f.l.), others represented by abrasion surfaces. in particular, transgressive episodes, dated 125-85 ka, are recognized in the taranto area (hearty & dai pra, 1985; dai pra & (hearty, 1992). belluomini et alii (2002) present results regarding the ages of different units on the basis of morphological evidence and palaeontological characteristics. different tectonic settings have been inferred for the taranto coastal area. the evidence suggests tectonic uplift also in post-tyrrhenian times, even though certain indicators of past sea-level stands are lacking (ferranti et alii, 2006). recent offshore research reveals a present-day shelf-slope system (pescatore & senatore, 1986) characterized by a shelf of varying widths, cut by several channels, and by terraces linked to recent transgression. rapid sedimentation and catastrophic failures are the main processes affecting this depositional system, which is connected to the deep taranto canyon. the local succession the stratigraphic succession, displaying an overall thickness of about 18 m, crops out along the sides of a low hill, on top of which a coastal medieval tower stands (torre ovo, fig. 2). in vertical succession, a variably exposed greyish muddy fine sand is transgressed by a marine biocalcarenite (exposed for about 11 m). pervasively bioturbated yellowish bioclastic sand, locally preserved as brownish biocalcarenite, lay in disconformity against the older deposits. the basal part of this last unit is locally included in a reddish terrigenous conglomerate. two measured sections are schematically drawn in fig.3. fig. 1 location map of study area and recent bathymetry (in metres) of taranto gulf. the toothed line corresponds to the front of the allochthonous trust sheets of the apennines (modified from pescatore & senatore, 1986). 1: apulian foreland, 2: bradanic foredeep, 3: southern apennines chain unit. localizzazione dell’area studiata e batimetria attuale (in metri) del golfo di taranto. la linea dentellata corrisponde al fronte delle falde di sovrascorrimento alloctone dell’appennino (modificato da pescatore & senatore, 1986). 1: avanpaese apulo, 2: unità della fossa bradanica, 3: unità della catena appenninica. fig. 2 the pleistocene succession near torre ovo hill: marine muddy silt (1), marine calcarenite (2). the unit 3, laying in disconformity on units 1 and 2, is composed by a brownish calcarenite (3a), and a reddish terrigenous conglomerate (3b). la successione pleistocenica affiorante presso la collinetta torre ovo: silt fangosi marini (1), calcarenite marina (2); l’unità 3, trasgressiva sulle precedenti unità, è composta di una calcarenite brunastra (3a) e da un conglomerato terroso rossastro (3b). unit description and interpretation unit 1 the exposed part of the unit is composed of gently layered greyish muddy fine sand (pl. 2, 7) which coarsens upwards and is mainly composed of angular quartz grains and minute plant debris. the layers, 2-4 cm thick, are normally graded from fine sand to silt. the shelly macrofauna is represented only by dispersed external moulds of nassarius cf. limatus, whilst aragonite shells have disappeared. in the present-day mediterranean, this species is considered preferential of muddy detritic bottom (de) and of coastal detritic bottom (dc) biocoenoses (caldara et alii, 1989). the ichnofossils are represented by minute sinuous galleries (≈1 mm wide, bioturbation index (bi) = 3-4, locally), associated with few scattered galleries (around 5-6 mm wide), passively filled with red sand, some meniscus structures and rare large burrows up to 30cm wide (bi =1) in paramoudra-preservation (pl. 1, 1-3). the trace fossils, therefore, suggest reworking by meiofaunal organisms, mobile worms, burrowing echinoids, and crustaceans. the upper surface of the unit is irregularly erosional and is underlain by a concentration of pedogenic chalky nodules (pl. 1, 5) and by few clasts reworked from older deposits occurring below and on the erosional surface of unit 1 (pl. 1, 4; pl.2, 6). on the basis of general features, the unit has been correlated to nearby deposits attributed to middle pleistocene by belluomini et alii (2002). interpretation. the biotope, dominated by burrowing organisms, was possibly located in a protected zone of the deep inner shelf. the fossil community could be compared to a facies of the recent muddy sand (se) biocoenosis under stressing conditions. the development of shelly benthic fauna was probably hampered by the high frequency of physical disturbance and, maybe, by amensal relationships. the disappearance of aragonite shells and the presence of numerous chalky nodules, some of which can be attributed 93palaeontological and sedimentologic ... to rhizoliths, suggest emergence and sub-aerial exposure of the deposit during a warm and dry period. during this period an intense, vadose diagenesis, was possibly responsible for paramoudra-preservation. bromley et alii (1975), in deeper deposits, partially anoxic, suggest an early diagenesis for paramoudras. unit 2 unit 2, about 11 m thick, is mostly represented by calcarenite and secondarily by calcirudite beds, and may be subdivided into four sub-units (2a to 2d): sub-unit 2a this interval about 120 cm thick consists of calcirudite grading upwards into mediumgrained calcarenite. the basal surface is sharp and irregular. the lowermost bed (20 cm in thickness) is composed of granules (around 2-3 mm) and pebbles (2-3 cm) including a few rounded blocks of paramoudras (on average 6-7 cm, occasionally up to 20 cm in diameter) and sub-angular clasts of algal calcarenite (up to 25 cm), reworked from the older units (pl. 1, 5, pl. 2, 6). upwards the deposit gradually changes into coarse calcarenite with a few allochthonous shells and, at the top, into fine calcarenite characterized by hummocky crossstratification. in the coarse calcarenite, some shells of patella aspera, gibbula varia, monodonta turbinata, columbella rustica, arca noae, conus mediterraneus, cerithium vulgatum, lima lima, exaplex trunculus and mitrella scripta occur either dispersed or forming lenses of randomly oriented, sparse shells. removal and dragging of shells from fossil communities comparable to those of the present-day mediterranean sea (sensu pérès & picard, 1964) of nearshore and inner shelf biotopes, i.e. gi (infralittoral gravels), hp (posidonia meadows) biocoenoses in the coarse calcarenite and sgcf (coarse sand and fine gravel under bottom current), sfbc (fine well sorted sand) biocoenoses in the fine calcarenite, may be deduced, in agreement with the physical structures which suggest a shoreface setting (the acronysms are those used by the same aa). sub-unit 2b this sub-unit is a package of beds about 250 cm thick. the lower interval is composed of normally graded (rudite to medium-grained calcarenite) composite beds, bounded by planar-parallel surfaces. a single massive biocalcirudite bed is composed of coarse bioclasts and bounded by wavy surfaces (fig. 4). the subrounded clasts are mostly calcareous algae, bryozoans, and mollusc shells which are commonly bioeroded (mostly entobia geometrica). these are included and seat in a mixed quartz-bioclastic matrix. the lowermost bed of this unit is characterized by fig. 3 log of two studied sections. log di due sezioni studiate. 94 a thin discontinuous sedimentologic concentration of densely packed, convex-up and imbricated, complete valves of mytilus galloprovincialis (pl. 2, 2) with indeterminable gastropod fragments encrusted by calcareous algae. the following layer includes discontinuous flat concentrations of loosely packed convex-up mytil id valves, replaced upwards by glycymeris glycymeris, mostly in small concentrations with valves chaotically oriented or nested (pl. 2, 9). rarely shells of cerithium vulgatum, disarticulated ostrea edulis valves bearing entobia laquea, and emarginula elongata have been observed. dispersed and randomly oriented disarticulated shells are less common upwards; rarely, complete valves occur nested and grouped in flat lenses. most abundant are specimens of bolma rugosa and ellipsoidal rhodoliths, followed by a few valves and shells of chlamys and aequipecten, rare mytilids, venus verrucosa, spondylus gaederopus, glycymeris glycymeris, and cerithium vulgatum. in this part of sub-unit 2b the fauna is represented by allochthonous and parautochthonous components. the upper 50 cm of the interval is composed of whitish, poorly compacted, medium-grained bioclastic sand with some dispersed bolma shells and rare manupecten pesfelix, chlamys multistriata, and pecten jacobaeus valves; locally this deposit is more fossiliferous and includes nested and stacked valves and sparse gastropods (mainly b. rugosa). upwards, a few crusts of calcareous algae are added. the fossil assemblages, composed of typical elements of different recent biocoenoses (ap – photophilous algae -, sfbc, sgcf) suggest that a certain percentage of the shells were transported and accumulated by storm-induced flows on a soft substrate of the inner shelf. upwards, the autochthonous and parautochthonous fossils indicate a transition to a deeper paleocommunity located in the middle shelf, comparable to a shallow facies of the recent-day dc biocoenosis. the appearance near the top of crusts of calcareous algae denotes a transition toward a new facies of the palaeocommunity. sub-unit 2c the massive interval is made up of a bio-calcirudite bed (80 cm thick), white (greyish when weathed) due to the abundance of irregular crusts of peyssonnellaceae included in a bioclastic mud matrix. a discontinuity surface, indicated by an abrupt compositional change (from poorly fossiliferous sand to compacted algal calcarenite), marks the base. the bioclasts are represented by large (on average 5÷6 cm in diameter) crusts of calcareous algae, with dispersed molluscan and bryozoan fragments. unbroken fossils are dispersed, mostly belonging to bolma rugosa, whose shells are normally encrusted by calcareous algae, and secondarily to manupecten pesfelis and neopycnodonte cochlear (fig. 5). this association is comparable to the recent “coralligène de plateau” biocoenosis (pérès & picard, 1964), recently considered a low-energy facies of the coastal detritic biocoenosis. the development of the free peyssonnellaceae facies needs alternate periods of whirling by storm-induced currents and of decantation in a quiet sea (pérès, 1967). fig. 4 sub-unit 2b. to note the bed (1), 20cm thick, bounded by wavy surfaces. sotto-unità 2b. é evidenziato uno strato (1), spesso 20cm, limitato superiormente ed inferiormente da superfici ondulate. fig. 5 detail of sub-unit 2c. dettaglio della sotto-unità 2c. a. d’alessandro & f. loiacono 95 sub-unit 2d this interval is a whitish mediumto fine grained biocalcarenite, about 600 cm thick. it is predominantly made up of composite beds, 1 m thick on average, formed by 2÷3 sub-layers individually grading upwards from calcirudite into fine calcarenite. the calcirudites are composed of abundant rounded rhodoliths, mollusc fragments of variable sizes, celleporiform bryozoans, cladocora, and rare unbroken macrofossils. in general, composite beds increase in number upwards. the laminar-foliose algal crusts and manupecten pesfelis decrease and disappear upwards, the former more rapidly than the latter. bolma rugosa shells decrease in abundance but increase in size, whereas rhodoliths with closely spaced short branches, celleporiform fragments, glycymeris valves, and deeply bioeroded valves of spondylus gaederopus increase. a few large fragments of cladocora coespitosa or complete colonies of it, albeit not in life position, appear in the upper part. the upper 40 cm are characterized by biogenic concentrations made up of densely packed to dispersed fossils mostly represented by a flat and large morphotype of cladocora colonies in life positions (pl. 1, 8), locally encrusted by tubes of petaloconchus subcancellatus , and accompanied by organisms preferring shallow biotopes such as arca noae, spondylus gaederopus, cardita calyculata, chama sp., striarca lactea, and shells of diodora cf. italica, patella caerulea, conus mediterraneus, and rare ocenebra erinaceous. largesized dispersed shells of bolma rugosa occur in the fine calcarenite. taphonomic features, gradual taxonomic changes and growth forms of corals and calcareous algae provide evidence of palaeoenvironmental changes fostered by a trend towards lower net rate of sedimentation, increase in water energy, and higher luminosity probably linked to shallowing upward trend. interpretation. unit 2 is thought to represent a depositional sequence. lack of sediments deposited during the middle pleistocene, and presence, in the basal lag of sub-unit 2a, of rare sub-angular clasts of algal calcarenite (possibly reworked from m.i.s.7 deposits), suggest that a ravinement surface was cut when the sea level rose during a successive late pleistocene highstand which may be attributed to m.i.s.5.5, even though senegalese faunal elements are lacking. this erosion is recorded by an unconformity surface covered by the lag with reworked components. the retrogradational sequence is composed of sediments deposited during the transgressive systems tract (sub-units 2a-b). during the interval of minimum rate of sedimentation (maximum flooding) characterized by a particular hydrodynamic condition, a paleocommunity comparable to the recent “coralligéne de plateau” biocoenosis was able to flourish (2c). the thickness of sub-interval 2c suggests a relatively long period of stillstand (in agreement with forsström, 2001; caputo, 2007). the succession ends with sediments (2d) deposited during the relative fall of the sea level (fsst) as suggested by the biotic changes in the fossil assemblages indicative of shallower habitats, by the taphonomic features of skeletal elements, and by the depositional features of the composite beds. unit 3 sub-unit 3a. in three outcrops, each a few hundred meters apart, dark greyish calcarenite, weathered into yellowish barren lime sand by oxidation, downlaps against the base of unit 2, and crops out above sea level for a thickness of 2-3 metres. the quite well sorted sediment is composed of comminuted bioclastic debris and subordinately of sub-rounded quartz grains. it is pervasively bioturbated (bi = 5-6) by unwalled, passively filled, indeterminate complex burrows which in the lower part of the unit locally show gentle laminations. long shafts (bi = 3-4) attributed to camborygma, postdate the primary burrow systems. due to differences in preservation, the deposits present variable appearances. in the northern locality the sand is compacted but not hardened, so that the ichnofossils are partly destroyed by waves; usually the shafts (fig. 6) have been passively filled by sand, lack walls, and rare horizontal galleries of the same size can be observed. if the shafts are preserved in calcarenite, they are empty and the boundaries are thickened by diagenesis. in one outcrop, camborygma shafts are absent near the sea level. many rounded blocks from sub-unit 2d occur in the upper part of unit 3 and completely or in part cover the camborygma shafts (pl. 2, 5). the blocks are larger landwards and disappear towards the sea. a cross-section exposed below the tower shows the calcarenite partially lying on a small “tongue” of terrigenous conglomerate of sub-unit 3b. this calcarenite in proximity of the slump scar is thinner, more yellowish, with long shafts that rapidly decrease and disappear, so that only the indeterminate complex burrow systems are seen (pl. 1, 6). fig. 6 – subunit 3a: camborygma shafts preserved in cohesive sands. sotto-unità 3a: colonne attribuite a camborygma presenti nelle sabbie coesive. palaeontological and sedimentologic ... 96 sub-unit 3b. the subunit is only locally present and is partly coeval whit 3a. reddish deposits, some metres thick, cut directly, the muddy silt (unit 1) or the marine calcarenite (unit 2), with a strong angular unconformity. they are composed of massive terrigenous sediments with sub-angular calcarenite pebbles and include rare large lenses of coarse sand thinning landwards (fig. 7). the intercalated coarse sands are crossed by dispersed camborygma shafts (pl. 2, 4) with thick diagenetic walls that cross numerous tangled networks (as in unit 3a). interpretation. the well sorted, subrounded grains, the high density of complex boxworks, and the presence of a faint oblique stratification in the lower part of the deposits suggest an intertidal environment, possibly transitional to backshore. the presence of camborygma, attributed to the continental, low-diversity scoyenia ichnofacies (sensu buatois et alii, 2002), suggests events of colonisation by continental crabs (that is crayfish) in alluvial environments with a deep and oscillating water table (hasiotis & mitchell, 1993; kowalewski et alii, 1998, buatois & màngano, 2007). abundance and length of shafts are related to the depth of the water table. large rounded blocks from unit 2 indicate that the deposits of that unit had become lithified during a phase of subaerial exposure. moreover the absence of bioeroding and encrusting organisms suggests that the blocks underwent gravity flows along steep cliffs or coastal gullies. thus, detrital deposits of sub-unit 3b are inferred to infill topographic depressions due to erosion and gravity failure. fig. 7 unit 3: (a) a coarse lens of sand thins landwards; (b) abrasion surface cutting the calcarenite of sub-unit 3a. unità 3: (1) una grossa lente di sabbia che si assottiglia verso terra; (2) superficie di abrasione che taglia la calcarenite della sotto-unità 3a. fig. 8 inferred sequence stratigraphy of the succession (synthetic log) with inferred variation of the sea level. sb = sequence boundary; ts = transgressive surface; ecotone between biocoenoses are linked wish slash mark; arrows indicate trends between community changes. supposta sequenza stratigrafica della successione (log sintetico) con le variazioni dedotte del livello del mare. sb = limite di sequenza; ts = superficie di trasgressione; gli ecotoni fra le biocenosi sono collegati con slash mark; le frecce indicano le tendenze dei cambiamenti di comunità. a. d’alessandro & f. loiacono the sub-unit 3b is similar to pinkish/red deposits cropping out south of taranto and referred by belluomini et alii (2002) to m.i.s 3. discussion and conclusion the integrated analysis of the torre ovo stratigraphic succession is a contribution to reconstruct the sedimentary evolution and the controlling factors during the middle-late pleistocene in this stretch of salento coast. the sequences recognized and correlated in the studied sections (figs. 3, 8) allow to distinguish the following events: deposition of marine muddy fine sand (unit 1, inferred age middle pleistocene) was followed by a drastic relative sea-level fall. this lead to subaerial exposure and erosion in a hot, semi-arid climate of both unit 1 and an algal calcarenite (possibly middle pleistocene, m.i.s.7), as indicated by the presence of reworked paramoudras and calcarenitic blocks into the lag of the overlying marine unit (unit 2). the latter can be regarded as a depositional sequence. the transgressive systems tract, represented by calcirudite and calcarenite beds, is followed by a fossiliferous facies that records condensation. the succession ends with sediments deposited during the falling stage system tract. a sea-level fall or local uplift of the area caused the subaerial exposure of unit 2. younger deposits (unit 3) downlap against part of units 1 and 2. features of the unit suggest a transition from quasi-marine to continental settings characterized by periodically subaerial exposure as confirmed by the freshwater ichnofacies. the deposit of sub-unit 3a is pervasively bioturbated. the long shafts record an event of opportunistic colonisation by crayfishes, on firmgrounds characterized by a fluctuating freshwater table. subsequent erosion of the top of sub-unit 3a, sub-rounded blocks from sub-unit 2d found on the erosive surface, deposition of massive, terrigenous sediments and gravity flows all agree with the suggested evolution. finally, an abrasion surface, about 30 cm above the present coastline (fig. 7), cuts the deposits of subunit 3a, thus suggesting a new phase of sea level highstand. systematic ichnology ophiomorpha-like structures in paramoudra-preservation (pl. 1, 1-3) description in a yellow-greenish muddy silt unit, rare solitary sub-cylindrical structures sub-vertical and transversal occur. commonly large parts of fallen down “cylinders” are piled up at the foot of the sections and allow a precise description of the structures. the large “cylinder” is composed of one central, apparently unbranched tube, 3-4 cm. wide, passively filled with rarely preserved brown, compacted muddy sand. the tube is surrounded by a thick wall of yellow siltstone lithologically similar to the enveloping sediment, hardened by vadose diagenesis in form of “paramoudras”. the diameter of the complete structure can be up to 30 cm (pl. 1, fig.3). the biogenic central tubes may represent the ichnogenus ophiomorpha; the interpretation is doubtful because of the poor visibility of the ichnotaxonomic features. the transverse galleries commonly are weakly deformed or flattened (pl. 1, 1-2). the central tubes are usually enlarged by water circulation, and appear as empty galleries 8-9 cm wide. comparison these solitary structures differ from okinawatubus cylindricus noda in features of the external tube, which in our specimens are produced by cementation of the enclosing silty mud. 97 plate 1 tavola 1 figs. 1-3 ophiomorpha like in paramoudra-preservation. (1, 3) two large fragments crashed down: 1) is a vertically flattened specimen, 3) it is about 30 cm. wide; (2) a vertical exposition: the central gallery is surrounded by an incompletely formed and deformed paramoudra. gallerie simili a quelle di ophiomorpha con conservazione paramoudra. (1,3) due grossi frammenti crollati: 1) esemplare appiattito trasversalmente, 3) diametro di circa 30 cm. (2) esemplare in posto visibile su una parete verticale: la galleria centrale è circondata da una struttura paramoudra non completamente consolidata e deformata. fig. 4 unconformity surface between the muddy silt (unit 1) and the lag of sub-unit 2a. to note the numerous chalky nodules into the muddy silt, suggesting diagenetic alteration of roots. superficie di inconformità fra i silt fangosi (unità 1) e il lag della sotto-unità 2a. notare la presenza di numerosi noduli carbonatici nel silt fangoso che suggeriscono una alterazione diagenetica di radici. fig. 5 basal part of sub-unit 2a transgressive on unit 1. pebbles and reworked components of older units are present into the lag. parte basale della sotto-unità 2a trasgressiva sulla unità 1. il lag contiene ciottoli e componenti rimaneggiati delle unità più vecchie. fig. 6 below the slump scar, the calcarenite of sub-unit 3a is yellowish and bioturbated by indeterminate boxwork systems that replace the lateral ichnoassemblage characterized by the long shafts. sotto la nicchia di distacco, la calcarenite della sotto-unità 3a è giallastra e bioturbata da indeterminati sistemi biogenici tridimensionali che sostituiscono l’icnoassociazione laterale caratterizzata da lunghi shafts. fig. 7 oblique section of sub-unit 3a showing densely packed camborygma shafts. sezione obliqua della sotto-unità 3a mostrante l’alta densità dei camborygma shafts fig. 8 sub-unit 2d: cladocora coespitosa in life position. sotto-unità 2d: cladocora coespitosa in posizione di vita. palaeontological and sedimentologic ... preserved due to present-day erosion, is an array of irregular, minute knobby structures. the shafts commonly are loosely to densely packed (pl. 2, 3-8-10). where occasionally two of them are in contact they have an oval-shape being partly fused. the rare and dispersed shafts that occur in the sand bed of sub-unit 3b are those with a large diameter (6-7 cm) and somewhat thicker “burrow linings” due to diagenetic mineralization (pl. 2, 4). in both sub-units the shafts never cross each other. comparisons skolithos linearis, commonly shorter and thinner, is similar for in also having a simple, vertical shape. dense burrows of skolithos have been recorded from freshwater and terrestrial settings (e.g. boutois and mángano, 2004; melchor et alii, 2006;) although skolithos ichnocoenosis is more typical of lower littoral to infralittoral, moderate to high-energy conditions (frey et alii, 1990). however, features of the torre ovo traces, palaeontological and granulometric features of sub-unit 3a, as well as their occurrence in the undoubtedly terrestrial sub-unit 3b suggest an attribution to camborygma burrows made by continental crabs in firm sediments. psilonichnus upsilon, which in modern environments is typically present in the uppermost foreshore and backshore of beaches, dunes, washover fans and tidal f lats, is morphologically quite different. psilonichnus tubiformis can reach lengths of over 200 cm, but is characterized by short side branches at irregular intervals; the yor u-shaped tube continues downward as a straight to slightly curved or somewhat twisted tube (nesbitt and campbell 2002). cylindrical burrows up to 2 m in length, abundant in coastal muddy deposits, were attributed by nara and kotake (1997) to psilonichnus isp. however the morphology of the surfaces of the burrows and their location in continental sand (sub-unit 3b) suggest different origin of our ichnofossils. remarks the burrows have been attributed to camborygma cf. eumekenomos mostly for their size and surface features, even though the presence of basal corridors is uncertain. the absence of chimney structures in the upper reaches of burrows can be ascribed to erosion. the burrows probably originated at the same palaeosurface. the absence of other ichnospecies of camborygma may further imply that the burrows record a single generation of a monospecific tracemaker. the differences in shaft size and variation in density in the two beds may have been caused by spatial heterogeneity of the groundwater level, soil moisture and vegetation cover (kowalewski et alii, 1998). the unwalled burrows of the crayfish are well preserved due to their construction in firm substrates often subaerially exposed and pedogenically altered; in this examined case mostly for the rapid burial by terrigenous conglomerate deposits. ichnotaxonomically, the ichnospecies is characterized by its simple architecture, lack of lining, sharp burrow boundary, and presence of bioglyphs. the hardened shafts were emptied probably during the renewed rise of the sea level. burrows not exposed to wave action are still filled by sands. camborygma cf. eumekenomos hasiotis and mithchell (pl. 1, 7, pl. 2, 1-3-4-8-10) description sub-unit 3a: straight shafts, more than 2 m long (pl. 1, 7, pl. 2, 1), range in diameters from 2 6 cm occur empty in calcarenite and passively filled in firm sand. in horizontal thin-sections the shaft boundary shows compaction of adjacent sediment. where sand infilling is preserved (presumably in the basal part) horizontal galleries of the same size as the shafts are present and can be interpreted as corridors described in c. eumekenomos. the superficial morphology, poorly 100 plate 2 tavola 2 fig. 1 camborygma shafts preserved in sub-unit 3a. camborygma shafts fossilizzati nella sotto-unità 3a. fig. 2 sedimentological concentration of denselyto loosely packed disarticulated valves of mytilus galloprovincialis. top view. concentrazione sedimentologica di valve disarticolate di mytilus galloprovincialis la cui densità varia da denselyto loosely packed (sensu kidwell, 1991). veduta dall’alto. figs. 3, 5, 8, 10 camborygma shafts in sub-unit 3a. note the different dispositions of the shafts. figure 5: blocks from unit 2 failed in the calcarenite sub-unit 3a, partly cover shafts of camborygma. hammer for scale.top view. camborygma shafts nella sotto-unità 3a. notare la differente disposizione degli shafts. nella figura 5 si può notare che la formazione delle tracce è precedente alla deposizione dei ciottoli i quali ricoprono i camborygma shafts. la scala è indicata dal martello. veduta dall’alto. fig. 4 the dispersed shafts in the subunit 3b show thicker “burrow lining” and somewhat larger diameter (6-7cm) compared with those of sub-unit 3a. le tane della sotto-unità 3b sono molto minori e dispersed rispetto a quelle della sotto-unità 3a; inoltre hanno “pareti” più spesse e in alcuni casi un diametro superiore (6-7cm). fig. 6 large fragment of “paramoudras” in the lag of sub-unit 2a. frammenti di grandi dimensioni di paramoudras nel lag della sotto-unità 2a. fig.7 unit 1, detail of the layered muddy silt and muddy fine sand. the vertical structures can be mud craks filled by sediment of overlying unit 3a. unità 1, dettaglio dell’alternanza degli straterelli di silt fangoso e di sabbie fini fangose (straterello più esile e più chiaro). le strutture verticali sono probabilmente fratture da disseccamento, riempite dal sedimento dell’unità 3a. fig. 9 glycymeris glycymeris valves chaotically oriented and nested or convex-up in small pavements. valve di glycymeris glycymeris orientate caoticamente e “annidati” o disposti con le convessità in alto, in esili concentrazioni. a. d’alessandro & f. loiacono acknowledgements we thank g. mastronuzzi for useful discussions about the age. f. massari and f. fürsich are greatly acknowledged for useful remarks and linguistic improvement of the manuscript. the work was supported by a grant of “ricerca ateneo” bari university to f. loiacono. references agip (1977) temperature sotterranee (brugora ed). segrate, milano, 1390 pp. belluomini g., caldara m., casini c., cerasoli m., mandra l., mastronuzzi g., palmentola g., sansò p., tuccimei p., vesica p. l. (2002) the age of late pleistocene shorelines and tectonic activity of taranto area, southern italy. quaternary sc. rev., 21, 525-547. bourcier m. (1981) nouvelles localisations de quelques facies des fonds détritiques côtiers dans le parc national de port-cros (france, méditerranée). rapp. comm. int. mer médit., 27 (2), 121-122. bromley r.g., schulz m.g. & peake n.b. (1975) paramoudras: giant flints, long burrows and the early diagenesis o chalks. det kongelige danske videnskabernes selakab biologiske skrifter, 20, 1-31 buatois l.a., mangano m.g., & aceñolaza f.g. (2002) trazas fósiles. ed. esp. mef 2, 382 pp., bahìa blanca (argentina). boutois l.a. and mángano m.g. (2004) animal-substrate interactions in freshwater environments: applications of ichnology in facies and sequence stratigraphic analysis of fluvio-lacustrine successions, in d. mcillroy (ed) the application of ichnology to palaeonvironmental and stratigraphic analysis, geological society special publucation 228, 311-333. buatois l. a., & màngano, m. g. (2007) invertebrate ichnology of continental freshwater environments, in william miller iii (ed.) trace fossils. concepts, problems. prospects. 285-323. elsevier. caldara m., d’alessandro a., & loiacono f. (1989) regressive pleistocene sequenze near gravina in puglia, southern italy:sedimentological and palaeoecological analyses. atti 3° simposio ecol. paleocol. comunità bentoniche. 417-468. caputo r. (2007) sea-level curves: perplexities of an end-user in morphotectonic applications. glob. and plan. ch., 57, 417-423. d’alessandro a., massari f., davaud e., & ghibaudo g. (2004) pliocene-pleistocene sequences bounded by subaerial unconformities within foramol ramp calcarenites and mixed deposits. sedimentary geology. 166, 89-144. dai pra g. & (hearty p.j. (1992) i livelli marini pleistocenici del golfo di taranto. sintesi geocronostratigrafica e tettonica. mem. soc. geol. it. (1988), 41, 637-644. ferranti l., antonioli f., mauz b., amorosi a., dai pra g., mastronuzzi g., monaco c., ottù p., pappalardo m., radtke u., renda p., romano p., sansò p., & verrubbi v. (2006) markers of the last interglacial sea-level high stand along the coast of italy: tectonic implications. quaternary international 145-146, 30-54. 101 forsström l. (2001) duration of interglacials: a controversial question. quat. sci. rev., 20, 1577-1586. frey r.w., pemberton s.g. & saunders t.d. (1990) ichnofacies and bathymetry: a passive relationship. jour. paleont., 64, 155-158. hasiotis s.t., & mitchell c.e. (1993) a comparison of crayfish burrow morphologies: triassic and holocene fossil, paleoand neo-ichnological evidence, and the identification of their burrowing signature. ichnos, 2, 291-314. (hearty p.j. & dai pra g. (1985) aminostratigraphy and uranium dating of quaternary shorelines in the puglia region of southeast italy. proc. fifth intern. coral reef congress, tahiti, 3, 163-169. kidwell s.m. (1991) the stratigraphy of shell concentrations, in allison p.a. and briggs d.e. (eds) taphonomy. releasing the data locked in the fossil record. topics in geobioloy, 9, 212-279. kowalewki m., demko t.m., hasiotis s.t., & newell d. (1998) quantitative ichnology of triassic crayfish burrows (camborygma eumekenomos): ichnofossils as linkages to population paleoecology. ichnos, 6, 5-21. melchor r.n., bedatau e., de valais s., genise j. f. (2006) lithofacies distribution of invertebrate and vertebrate trace-fossil assemblages in an early mesozoic ephemeral fluvio-lacustrine system from argentina : implications for the scoyenia ichnofacies. palaeogeography, palaeoclimatology, palaeoecology, 239, 253-285. monegatti p. & raffi s. (2001) taxonomic diversità and stratigraphic distribution of mediterranean pliocene bivalves. palaeogeography, palaeoclimatology, palaeoecology, 165, 171-193. monegatti p. & raffi s. (2007) mediterranean-middle eastern atlantic façade: molluscan biogeagraphy & ecobiostratigraphy throughout the late neogene. açoreana, supl. 5, 126-139. nara m. & kotake n. (1997) trace fossils psilonichnus in the middle to late pleistocene shimosa group. journal of the geological society of japan, 103, 971-981 (in japanese with english abstract). nesbitt e.a. & campbell k.a. (2002) a new psilonichnus ichnospecies attributed to mudshrimp upogebia in estuarine settings. j.paleont., 76, 892-901. noda h. (1983) cylindrical burrows from the pliocene shinzato formation in okinawa-jima, okinawa prefecture, southern japan. ann. rep. inst. geoscience, un. tsukuba, 9, 61-64. pérès j. m. (1967) the mediterranean benthos. ocean. mar. biol. ann. rev. 5, 449-533. pérès j. m. & picard j. (1964) nouveau manuel de bionomie benthique de la mer méditerranées. rec.trav. st. mar. endoume, 31, 137 pp., marseille. pescatore t. & senatore m.r. (1986) a comparison between a present-day (taranto gulf) and a miocene (irpinian basin) foredeep of the southern apennines (italy), in p.a. allen & p.homewood (eds) foreland basins. spec. publ. int. ass. sediment. 8, 169-182. ms. ricevuto il 10 dicembre 2009 testo definitivo ricevuto il 24 maggio 2010 ms. received: december 10, 2009 final text received: may 24, 2010 palaeontological and sedimentologic ... amq abs giustini et al palcom 135-139 corr.pub available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 135 139 an introduction to the early holocene “eolian” deposits of grotta romanelli, apulia, southern italy francesca giustini 1, fabio bona 4, mauro brilli 1, jacopo conti 2, alessia d’agostino 2, giuseppe lembo 3, ilaria mazzini 1, beniamino mecozzi 2, brunella muttillo 3, raffaele sardella 2 1 istituto di geologia ambientale e geoingegneria (igag), cnr, roma, italy 2 dipartimento di scienze della terra, università di roma “sapienza”, roma, italy 3 dipartimento di studi umanistici, sezione di scienze preistoriche e antropologiche, università degli studi di ferrara, ferrara, italy 4 dipartimento di scienze della terra “a. desio”, università degli studi di milano, milano, italy corresponding author: f. giustini <francesca.giustini@igag.cnr.it> abstract: due to its geographic position and geomorphological configuration, grotta romanelli acted as a sediment trap since at least mis 5. the so-called ‘terre brune’ sequence is a deposit mainly of eolian origin bearing upper palaeolithic artefacts and fossil remains of vertebrate fauna; it was deposited during the glacial-interglacial transition and the holocene. sedimentology and mineralogy of this deposit are investigated. the stratigraphic sequence provides a promising archive within which both human and climatic impacts can be studied. keywords: grain size, mineralogy, holocene, grotta romanelli, southern italy 1. introduction eolian deposits have long been considered a significant resource for the past environment reconstruction. eolian activity is, in fact, modulated/influenced by global climate changes (porter, 1989) as documented, for example, in the chinese loess plateau, i.e. one of the longest and most continuous palaeoclimatic records of the quaternary interglacial-glacial cycles (ding et al., 2005). in italy, quaternary eolian deposits were described in different sites (sevink & kummer, 1984; cremaschi, 1990; narcisi, 2000; giraudi et al., 2013; boretto et al., 2017). loess deposits in northern italy and the adriatic edge of central italy were associated to periglacial environment, whereas in central and southern italy their origin was attributed to dust coming from north africa, where arid conditions during mis 4 and 2 and in the late holocene may have enhanced the dust supply in southern mediterranean sector (giraudi, 1995; narcisi, 2000). eolian deposits accumulated in caves can provide archives of past climate and human-induced changes. these deposits are additionally a significant source of information about land-atmosphere transfer processes, atmospheric residence times, land-surface depositional processes (evans & soreghan, 2015). grotta romanelli, located on the adriatic coast of southern apulia (italy), is considered a key site for the mediterranean quaternary for its archaeological and palaeontological content. the cave opens in upper cretaceous limestone (bosellini et al., 1999) at about 7.4 m above sea level, and is filled with thick deposits containing rich fossil remains of vertebrate and a wide variety of artefacts (see sardella et al., 2018 and references therein). the stratigraphic sequence, as described by blanc (1920, 1928), schematically consists (from the top to the bottom) of: (i) an upper complex, called ‘terre brune’ (‘levels a-e’), bearing upper palaeolithic artefacts and vertebrate fauna including pinguinus impennis (= alca impennis in blanc, 1927); (ii) a thin stalagmitic layer (called ‘level f’), dated at 40,000± 3250 years (fornacarinaldi & radmilli, 1968); (iii) a deposit called ‘terre rosse’ (‘level g’); (iv) a thick stalagmitic layer (‘level h’); (v) a bone breccia (‘level i’), and (vi) a beach deposit (‘level k’) fig. 1 geological sketch of the coastal area of grotta romanelli bay (sardella et al., 2018). https://doi.org/10.26382/aiqua.2018.aiquaconference referred to the tyrrhenian stage (mis 5). the ‘terre brune’ and ‘terre rosse’ deposits are considered mainly of eolian origin (blanc, 1920, 1928; blanc & cortesi, 1941); according to radiocarbon dates, the ‘terre brune’ sequence appears to span from about 9.5 to 12 ka (alessio et al., 1965; bella et al., 1958; vogel & waterbolk, 1963). in this study we provide the first results of the sedimentological and mineralogical characterization of the ‘terre brune’ deposit, which may represent a record of the holocene climate in southern italy and provide a promising archive within which both human and climatic impacts can be studied. 2. materials and methods during september 2016 the stratigraphic section ss1, located in the western sector of the cave, was selected as the representative profile for a multidisciplinary study of ‘terre brune’ deposit. the ss1, about 2.80 m thick, was cleaned, documented and sampled at a resolution of ca. 3 cm (fig. 2). ninety-six samples were collected for sedimentological and mineralogical analyses. grain sizes were determined using a cilas 1064l laser diffraction particle size analyzer (range from 0.04 to 500 μm). the grain size fractions are according to the classification of wentworth (1922). mineralogy was determined using a philips pw1840 diffractometer (cuka/ni: 40 kv and 20 ma) on bulk sediment and on clay fraction of selected samples. identification of the mineral phases was determined with xpowder12 freeware software. the calcium carbonate content (caco3 %) was measured gas-volumetrically, by addition of hcl in a dietrich-frühling calcimeter. carbon (δ13c) and oxygen (δ18o) isotopes were determined on calcium carbonate contained in sediment sieved to < 20 μm, which reacted with 100% phosphoric acid at 70°c using a thermo gasbench device connected to a delta plus mass spectrometer. results are expressed in delta per mill versus vpdb standard. 3. results field observation of the section revealed the presence of cross-laminations and large-scale ripples of variable thickness (1 10 cm). these structures are made of dark brown, cracked clayey-silt sediment, or silty sand with dull yellowish color. layers of detrital limestone, generally rich in palaeontological and archaeological remains, are also present. laboratory analyses confirmed that the grain size distribution is generally bimodal, with elevated percentages in clay (from 27 to 59%, mean 47%) and silt (from 26 to 54%, mean 44%) grain size fractions; in several samples the sand fractions are also detected. variations in these proxies along the sedimentary sequence are shown in fig. 3. the grain size records show three intervals (55 75 cm, 90 130 cm and 195 230 cm) with lower percentage of clay fraction (fig. 3a) that is counterbalanced by the content of the sand fractions (>63 μm, fig. 3c-e). x-ray diffraction shows that samples are mainly composed by quartz and minor amounts of calcite, plagioclase, feldspar. oriented xrd of the finest fraction of selected samples revealed the presence of clay minerals of the illite and kaolinite groups. the intensity of the main peak of quartz was used for a further stratigraphic record (fig. 3f). it shows that when sediments are enriched in clay fraction they are depleted in quartz and vice versa, because the fine fraction contains higher amounts of clay minerals. carbonate contents vary from 0 to ca. 12% (fig. 3g); of note is that the samples in which carbonate was not detected still contain small amounts of carbonate that are below the detection limit of the method. the interval between 90 and 190 cm comprises the largest amount of calcite particles; this part of the sequence is also particularly rich in palaeontological and archaeological remains. calcite contained in the grain size fraction <20 μm has oxygen isotope composition between -15.52‰ and 136 giustini f. et al. fig. 2 picture of stratigraphic section ss1. 137 -0.55‰ vs. vpdb. the δ18o record is shown in fig. 3h; the upper (top 70 cm) and the lower (200 280 cm) parts of the curve show several abrupt shifts towards very low isotopic values, up to -15.52‰ and -12.14‰, respectively. between 90 and 190 cm the record approximately shows uniform isotopic compositions with an average of -3.65‰; this value would indicate that the carbonate fraction at this level has mainly the contribution of the isotopic signal of the marine carbonates, then it has in prevalence detrital nature. 4. discussion and conclusion the ‘terre brune’ deposit was mainly considered of eolian origin, due to the mineralogical composition and morphology of quartz grains (blanc, 1920, 1928; blanc & cortesi, 1941). our data are in accordance with the mineralogical and sedimentological composition presented in the previous studies about grotta romanelli, and with studies from other italian sites where eolian deposits were identified (narcisi, 2000; 2001; giraudi et al., 2013). available chronology of the ‘terre brune’ (alessio et al., 1965; bella et al., 1958; vogel & waterbolk, 1963) temporally constraints the deposit to the beginning of holocene, although the lowermost portion has never been dated. preliminary results of new radiocarbon dating consistently indicate that the investigated section was formed between the late last glacial and the early holocene (calcagnile et al., 2018), when different climates occurred in the mediterranean basin. various proxy data suggested dry and cold climate condition during the late glacial, enhanced meteoric precipitation during the transition from the late glacial to the holocene, a general climate amelioration and wetter conditions during early holocene, and a change toward the present-day dry regime at 6-5 ka bp (allen et al., 1999; sadori & narcisi, 2001; bar-matthews et al., 2003; zanchetta et al., 2007; martrat et al., 2014). the sedimentological and geochemical records of the ‘terre brune’ sequence were used to reconstruct the environmental variations related to climate changes during the late last glacial and the early holocene. sediments of the lower part of the sequence (200280 cm), that may be correlated to ‘levels d-e’ of blanc (1920) stratigraphy, are progressively enriched in medium sand and depleted in clay contents; also, the quartz content increases, whereas the carbonate content is low. as the coarsening of eolian input mainly depends on two factors, the wind speed and the distance from the source areas (muhs, 2013), our data suggest that deposition of this part of the sequence occurred during a period of more intense wind transport. the source of this sediment could have been eolian dust from sahara regions. loess formed by quartz of sahara origin, was identified in several italian sites, e.g. the lago di vico and lagaccione, maar lakes in central italy (narcisi, 2000; 2001; narcisi & anselmi, 1998), the island of lampedusa (giraudi, 2004), the high mountains of the central and southern apennines (frezzotti & giraudi, 1990; giraudi et al., 2013). this phase of deposition certainly took place before 12 ka bp. at that time it is likely that a coastal plain in front of grotta romanelli was still large and it may have also contributed to the fig. 3 (a) percentage of clay (<4 μm), (b) percentage of silt (4-63 μm), (c) percentage of very fine sand (63-125 μm), (d) percentage of fine sand (125-250 μm), (e) percentage of medium sand (63-125 μm), (f) intensity of main quartz peak (cps), (g) carbonate content (caco3%), (e) δ18o (‰ vs. vpdb) results plotted vs. depth for the stratigraphic section ss1 of ‘terre brune. levels according to blanc (1920) stratigraphy end published ages (*alessio et al., 1965; §bella et al., 1958; °vogel & waterbolk, 1963). holocene eolian deposits of grotta romanelli (southern italy) accretion of the ‘terre brune’; the coastal plain was evaluated 20 km wide at the last glacial maximum (22 ka bp), and characterized by different environments, from lagoon to wetland, possibly fringed by sand dunes (cassoli et al., 1979). palaeontological remains also indicate a terrestrial environment ranging from open semi-arid to an occasionally dried-out mud flat (sardella et al., 2018). in the interval going from 70 to 200 cm, possibly corresponding to ‘level c’ of blanc (1920) stratigraphy, the grain size distribution shows an increase of fine and very fine sands, whereas medium sand and clay decrease. an average decrease of quartz intensity also corresponds to carbonate content rise (up to 12%). the observed pattern suggests a decreased capacity of eolian energy to transport coarse particles. at this stage it is also possible that the record data respond to a progressive sea-level rise and a consequent reduction of the coastal plain which coincided with the main phase of deglaciation between ca. 11.5 ka bp (the end younger dryas) and ca. 8.2 ka bp (lambert et al., 2014). in particular the increase in carbonate content which is mainly of detrital origin, as isotopes would prove, may be considered the effect of the decrease of the eolian transport and the reduction of quartz mass capacity to dilute other mineral phases. considering that this part of the sequence is particularly rich in palaeontological and archaeological remains, it is possible to speculate that this detrital contribution could be additionally due to the human occupation. the upper part of the sequence (70 cm top) may correspond to the ‘level b’ of blanc’s stratigraphy. the sediment contains a considerable amount of clay and silt, whereas the sand fractions are virtually absent. quartz and carbonate content decrease. overall, this pattern points to a dramatically decline in the energy of eolian depositional mechanism and to an almost complete drowning of the coastal plain which cannot provide further sediments to contribute to the eolian wedge accretion. this is almost the last phase of sedimentation; the uppermost layer of the banc’s stratigraphy, the ‘level a’, was not preserved, due to both natural erosion and several years of excavations and research (sardella et al., 2018). the end of sedimentation in grotta romanelli occurred at about 6 ka bp, when 1) the coastal plain in front of grotta romanelli was greatly reduced and the sea level was about -7 m below the modern sea level (lambeck et al., 2004); and 2) prevailing wind directions changed, probably in relation with the termination of the african humid period (de santis & caldara 2015). acknowledgements we thank “soprintendenza archeologia belle arti e paesaggio per le province di brindisi lecce e taranto” (superintend dr. maria piccarreta and dr. laura masiello) for the excavation permission. we thank n. ciccarese, t. de santis, don piero frisullo and red coral (castro) for their logistical support, l. bellucci, d. a. iurino, f. strani and d. pushkina for their invaluable help during fieldwork. special thanks are due to p. plescia (cnr-igag) for grain size analyses, and s. stellino and m. preite martinez (dst-sapienza) for xrd and calcimetry analyses, respectively. the research was funded by sapienza progetto grandi scavi 2016 and 2017 (resp. r. sardella). references alessio m., bella f., bachecchi f., cortesi c. (1965) university of rome carbon-14 dates iii. radiocarbon, 7, 213-222. allen j.r.m., huntley b. (2009) last interglacial palaeovegetation, palaeoenvironments and chronology: a new record from lago grande di monticchio, southern italy. quaternary science reviews, 28, 1521-1538. bar-matthews m., ayalon a., gilmour m., matthews a., hawkesworth c.j. (2003) sea-land oxygen isotopic relationships from planktonic foraminifera and speleothems in the eastern mediterranean region and their implication for paleorainfall during interglacial intervals. geochimica et cosmochimica acta, 67, 3181-3199. bella f., blanc a.c., blanc g.a., cortesi c. (1958) una prima datazione con il carbonio 14 della formazione pleistocenica di grotta romanelli (terra d’otranto). quaternaria, 5, 87-94. blanc g.a. (1920) grotta romanelli i. stratigrafia dei depositi e natura e origine di essi. archivio per l’antropologia e la etnologia, 50, 1-39. blanc g.a. (1927) sulla presenza di alca impennis linn. nella formazione superiore di grotta romanelli in terra d’otranto. archivio per l’antropologia e la etnologia, 58, 155-186. blanc g.a. (1928) grotta romanelli ii. dati ecologici e paletnologici. archivio per l’antropologia e la etnologia, 58, 1-49. blanc g.a., cortesi c. (1941) interpretazione geochimica delle formazioni quaternarie di grotta romanelli (terre d’otranto). iii le sostanze umiche fossili. atti della reale accademia nazionale dei lincei. rendiconti della classe di scienze fisiche, matematiche e naturali, 7, 33-55. boretto g., zanchetta g., ciulli l., bini m., fallick a.e., lezzerini m., colonese a.c., zembo i., trombino l., regattieri e., sarti g. (2017) the loess deposits of buca dei corvi section (central italy): revisited. catena, 151, 225-237. bosellini a., bosellini f.r., colalongo m.l., parente m., russo a., vescogni a. (1999) stratigraphic architecture of the salento coast from capo d’ otranto to santa maria di leuca (apulia, southern italy). rivista italiana di paleontologia e stratigrafia, 105 (3), 397-416. calcagnile l., sardella r., mazzini i., giustini f., brilli m., d’elia m., braione e., conti j., mecozzi b., quarta g. (2018) new radiocarbon dating results from the upper paleolithic levels in grotta romanelli-italy. abstracts volume 23th international radiocarbon conference, june 17-22th 2018, trondheim, norway. (in press) cassoli p.f., segre a.g., segre e. (1979) evolution morphologique et écologique de la côte de castro (pouilles) dans le pléistocène final. colloques internationaux c.n.r.s., 219, 325-332. 138 giustini f. et al. cremaschi m. (1990) the loess in northern and central italy: a loess basin between the alps and the mediterranean region. quaderni di geodinamica alpina e quaternaria, 1, 1-187. de santis v., caldara m. (2015) the 5.5-4.5 kyr climatic transition as recorded by the sedimentation pattern of coastal deposits of the apulia region, southern italy. the holocene, 25(8), 1313-1329. ding z.l., derbyshire e., sun j.m., liu t.s. (2005) stepwise expansion of desert environment across northern china in the past 3.5 ma and implications for monsoon evolution. earth and planetary science letters, 237, 45-55. evans j.e., soreghan m. (2015) long-distance sediment transport and episodic resedimentation of pennsylvanian dust (eolian silt) in cave passages of the mississippian leadville limestone, southwestern colorado, usa. in: caves and karst acrosstime, feinberg j., gao y., alexander e.c., jr. (eds.). geological society of america special paper 516. fornaca-rinaldi g., radmilli a.m. (1968) datazione con il metodo 230th/238u di stalagmiti contenute in depositi musteriani. atti società toscana scienze naturali, 75(1), 639-646. frezzotti m., giraudi c. (1990) late glacial and holocene aeolian deposits and features near roccaraso (abruzzo, central italy). quaternary international, 5, 89-95. giraudi c. (1995) sedimenti eolici, variazioni climatiche ed influenza antropica: considerazioni su alcune piane intermontane dell’appennino abruzzese. il quaternario, 8(1), 211-216. giraudi c. (2004) the upper pleistocene to holocene sediments on the mediterranean island of lampedusa (italy). journal of quaternary science, 19(6), 537-545. giraudi c., zanchetta g., sulpizio r. (2013) a latepleistocene phase of saharan dust deposition in the high apennine mountains (italy). alpine and mediterranean quaternary, 26(2), 110-122. lambeck k., rouby h., purcell a., sun y., sambridge m. (2014) sea level and global ice volumes from the last glacial maximum to the holocene. pnas, 111, 15296-15303. martrat b., jimenez-amat p., zahn r., grimalt j.o. (2014) similarities and dissimilarities between the last two deglaciations and interglaciations in the north atlantic region. quaternary science reviews, 99, 122-134. moresi m., mongelli g. (1988) the relation between the terra rossa and the carbonate-free residue of the underlying limestones and dolostones of apulia, italy. clay minerals, 23, 439-446. muhs d.r. (2013) loess and its geomorphic, stratigraphic and paleoclimatic significance. aeolian geomorphology, 11, 149-183. narcisi b. (2000) late quaternary eolian deposition in central italy. quaternary research, 54, 246-252. narcisi b. (2001) palaeoenvironmental and palaeoclimatic implications of the late-quaternary sediment record of vico volcanic lake (central italy). journal of quaternary science, 16, 245-255. narcisi b., anselmi b. (1998) sedimentological investigations on a late quaternary lacustrine core from the lagaccione crater (central italy): palaeoclimatic and palaeoenvironmental inferences. quaternary international, 47/48, 21-28. porter s.c. (1989) volcanic records and loess deposits. in: global changes of the past vol. 2, bradley r.s. (ed.). ucar/oies global change institute, boulder, co., 295-320. sadori l., narcisi b. (2001) the postglacial record of environmental history from lago di pergusa, sicily. the holocene, 11 (6), 655-670. sardella r., mazzini i., giustini f., mecozzi b., brilli m., iurino d.a., lembo g., muttillo b., massussi m., sigari d., tucci s., voltaggio m. (2018) grotta romanelli (southern italy, apulia): legacies and issues in excavating a key site for the pleistocene of the mediterranean. rivista italiana di paleontologia e stratigrafia, 124(2), 247-264. sevink j., kummer e.a. (1984) eolian dust deposition on the giara di gesturi basalt plateau, sardinia. earth surface processes and landforms, 9, 357364. vogel j.c., waterbolk h.t (1963) groningen radiocarbon dates iv. radiocarbon, 5, 63-202. wentworth c.k. (1922) a scale of grade and class terms for clastic sediments. the journal of geology, 30, 377-392. zanchetta g., drysdale r.n., hellstrom j.c., fallick a.e., isola i., gagan m.k., pareschi m.t. (2007) enhanced rainfall in the western mediterranean during deposition of sapropel s1: stalagmite evidence from corchia cave (central italy). quaternary science reviews, 26, 279-286. 139 holocene eolian deposits of grotta romanelli (southern italy) ms. received: may 15, 2018 final text received: may 21, 2018 140 available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 55 58 natural and anthropic events at la polledrara di cecanibbio (italy, rome): some significant examples cerilli eugenio 1 , fiore ivana 2 1 soprintendenza speciale archeologia belle arti e paesaggio di roma, roma, italy (collaborator) 2 museo delle civiltà. collaboratrice servizio bioarcheologia, roma, italy corresponding author: e. cerilli <cerillieugenio@gmail.com> abstract: in the site of la polledrara di cecanibbio (mis 9) the analysis of the river-bed morphology, combined to that of the spatial disposition of the accumulated skeletal remains and of their taphonomic modifications, allows to reconstruct the events that have led to the formation and evolution of the deposit. keywords: middle pleistocene, river-bed, elephant-human interactions 1. introduction the site of la polledrara di cecanibbio is located in the sabatini volcanic district, at an altitude of 83 m a.s.l., about 22 kilometers from rome near the via di boccea. between 1985 and 2013 the site was subject to regular excavations, funded by the then soprintendenza speciale per i beni archeologici di roma today soprintendenza speciale archeologia belle arti e paesaggio di roma (ssabap-rome), which exposed on an area of about 1200 meters square a bed portion of a small water course cut into a bank of compact volcaniclastic deposits (anzidei et al., 2012; castorina et al. 2015; santucci et al., 2016). in the year 2000, with a financial support of mibact, about 900 square meters of the site were covered by a prefabricated structure and it became a museum open to the visitors (fig. 1). the site is characterized by fluvial deposits that pass to fluvio-palustrine during a phase of high stand of the sea level (anzidei et al., 2012). the mineralogical composition of the volcanoclastic sediments that have filled the river-bed indicates an origin from several source rocks of the sabatini volcanic district (castorina et al., 2015). the recent dating of 325±2 ka, obtained with the 40ar/39ar method (pereira et al., 2017), confirm that the la polledrara site developed at the beginning of mis 9, in the final phase of the transgressive systems tract of the ponte galeria 6 fourth order sequence (anzidei et al., 2012), and therefore to the aurelia formation (milli & palombo, 2005; milli et al., 2011). among the 20,000 skeletal remains found, palaeoloxodon antiquus and bos primigenius are the dominant species followed by cervus elaphus; less abundant are the remains of sus scrofa, stephanorhinus cf. hemitoechus, equus ferus, canis lupus, vulpes vulpes, meles meles, felis silvestris, macaca sylvanus, lepus sp., murids and arvicolids; the herpetofauna and the avifauna (under study) are also well represented. on the basis of the present species, the isotopic data and the microwear on some elephant molars, it was hypothesized that at the time of deposition of the fossiliferous layers the landscape of la polledrara was characterized by a dense arboreal cover interspersed with open spaces in conditions of moderately humid and temperate/warm-temperate climate (palombo et al., 2005). the lack of pollen and plant fossil remains does not enable to confirm this hypothesis. the anthropic presence (homo heidelbergensis) is testified by hundreds of artifacts on flint and numerous tools on elephant bone. the site had to represent a point of attraction, as a source of food and raw material, for the hunter-gatherers bands who frequented the territory, as is clearly indicated for example by a skeleton of p. antiquus in partially preserved anatomical connection, the taphonomic layout of some of its bones and the archaeological artifacts associated with (santucci et al., 2016). 2. bed morphology and taphonomy of bone remains the action of the water flow, that took place in particular in the first phase of the river's history, is particularly evident on the surface of the river-bed where two areas are separated by a step of about 80 cm in height, which reduce until disappear towards the center of the watercourse. above it, the river bottom appears very irregular, characterized by raised and depressed areas. these irregularities obviously influenced the directions and intensities of the water flows. in this area the faunal remains have been almost all accumulated in the depressed areas, while they are scarce in the elevated portions, more exposed to the hydraulic action. furthermore, the summit of many of these zones have flat shape and show evident mud-cracks, testifying to their sub-aerial exposure. these evidences would indicate that periodic oscillations of the water table have occurred in this stretch of the channel, perhaps even noticeable and probably linked to seasonal variations in rainfall. otherwise, downstream of the step, the river bottom is flat, and the faunal remains are distributed along the https://doi.org/10.26382/aiqua.2018.aiquaconference surface of the river-bed with a distribution that reflects the current flow characteristics. for example, in some areas the long and narrow skeletal elements, such as the elephant's tusks, were arranged parallel or transversely to the water flow direction and constituted a barrier that favored the accumulation of other elements. in some cases, the whirlpools linked to the acceleration phase of the flow around an obstacle produced an undererosion around the skeletal element. except for a few exceptions, the faunal remains deposited on the bottom and often also the lithic ones, show extensively striated surfaces, high degree of fluitation of the upper face exposed to the water flow. on the other hand, the lower face of the remains, resting on the 56 cerilli e., fiore i. fig. 1 overview on the museum's showcase of the site, seen by se (ssabap-rome archive). fig. 2 right metacarpus of bos primigenius deposited with the plantar side at the bottom of the bed. the dorsal side (a), the margins of the proximal epiphysis (b) and the surface of the distal condyles (c) are strongly fluitated and abraded, with randomly oriented sediment abrasion scratches (d, e). the plantar side (f, g, h) is poorly fluitated, but intensively eroded, probably due to chemical aggression of the underlying sediment, the erosion has almost completely erased the traces of abrasion which are visible only in some areas (i). on the dorsal side and, less frequently, on the plantar one traces of plant roots are visible. the low degree of alteration from the exposure to atmospheric agents (behrensmeyer, 1978), especially wet-dry cycles, indicates that this skeletal element has been covered with sediment in a fairly short time (archive ssabap-rome). 57 bottom of the bed, is not transported instead it is very often strongly eroded (fig. 2). furthermore, on the remains deposited on the bottom, impact or trampling fractures are clearly evident, as well as the marks of intentional anthropogenic fracture for bone marrow extraction are well testified. finally, there is a marked differential conservation of the anatomical elements depending on the strength of their bony tissue: the resistant portions of elements of large animals, mainly represented by adult individuals, are more represented on the bottom, while the elements of young or small animals, or the skeletal portions with more abundant spongy tissue or with thinner compact tissue, are rare. on the bottom, elements in anatomical connection are never recognized, while they are well represented in the successive marshy phase, together with skeletal parts of small animals. these taphonomic characteristics indicate that during the fluvial phase the remains were transported by a muddy current and that, once deposited on the bottom, generally they did not significantly shift from their primary position and remained exposed to the water flow for a prolonged period of time. on the other hand, the remains deposited in the subsequent filling and swamping phase of the channel show show no or poor degree of fluitation, but in any case they are always intensively striated, where their surface has been able to record this alteration. this indicates that, after their transport within a muddy flow and their subsequent deposition, they were almost immediately covered by sediment. the formation of large accumulations of sediment caused the death of three elephants trapped in the mud (anzidei et al., 2012). one of these is of particular interest. in an area near the right bank, the skeleton of a pachyderm, certainly dead because trapped in the mud, is in close spatial relationship with more than 600 stone artifacts that indicate the scavenging of the carcass (santucci et al., 2016). anthropic exploitation (fig. 3) is also documented by remains with traces of impact and cutting from lithic tools, by percussion chips and bone tools with traces of use. some diaphyses of elephant's taphonomic examples at la polledrara di cecanibbio fig. 3 anthropogenic modifications in bones. 1 (a) femur with percussion flake still connected and (b) detail. 2 bone tools made from an elephant diaphysis. 3 (a) diaphysis of an elephant's long bone with concentration of percussion scars and of overlapped scars (yellow arrows), (b) detail at the microscope of striae from lithic tool. 4 (a-b) conchoidal flakes on a very large mammal long bone diaphysis, resulting from intentional bone fracturing, this kind of flake usually is not due to bone fracturing for marrow extraction, but rather may be the consequence of bone tool manufacturing. long bone show fracture patterns and a quantity, localization, concentration and overlapping of scars to interventions aimed to shape the raw material rather than to butchering activities. in conclusion, it seems undoubted that in la polledrara the main agents of accumulation of the bones were the flow of water inside a river-bed and the mud of the subsequent marsh phase, but it is also undeniable that the river and the marsh have attracted the human groups of hunter-gatherers who frequented the territory, because of the formidable possibilities of exploitation of animal carcasses, both for food and for the recovery of hard animal raw materials to produce artifacts. references anzidei a.p., bulgarelli g.m., catalano p., cerilli e., gallotti r., lemorini c., milli s., palombo m.r., pantano w., santucci e. (2012) ongoing research at the late middle pleistocene site of la polledrara di cecanibbio (central italy), with emphasis on human-elephant relationships. quaternary international, 255, 171-187. beherensmeyer a.k. (1978) taphonomic and ecologic information from bone weathering. paleobiology, 4 (2), 150-162. castorina f, masi u., milli s., anzidei a.p., bulgarelli g.m. (2015) geochemical and sr-nd isotopic characterization of middle pleistocene sediments from the paleontological site of la polledrara di cecanibbio (sabatini volcanic district, central italy). quaternary international, 357, 253-263. milli s., palombo m.r. (2005) the high resolution sequence stratigraphy and the mammal fossil record: a test in the middle-upper pleistocene deposits of the roman basin (latium, italy), quaternary international, 126-128, 251-270. milli s., palombo m.r., anzidei a.p. (2011) i depositi pleistocenici di ponte galeria e la polledrara di cecanibbio, guidebook post-congress field trip, aiqua 2011 (italian association for quaternary studies), rome, 26 february 2011. palombo m.r., filippi m.l., iacumin p., longinelli a., barbieri m., maras a. (2005) coupling tooth microwear and stable isotope analyses for palaeodiet reconstruction: the case study of late middle pleistocene elephas (palaeoloxodon) antiquus teeth from central italy (rome area), quaternary international, 126-128, 153-170. pereira a., nomade s., faulguères c., bahain j.j., tombret o., garcia t., voichet p., bulgarelli g.m., anzidei a.p. (2017) 40ar/39ar and esr/u-series data for the la polledrara di cecanibbio archaeological site (lazio, italy). journal of archaeological science, reports, 15, 20-29. santucci e., marano f., cerilli e., fiore i., lemorini c., palombo m.r., anzidei a.p., bulgarelli g.m. (2016) palaeoloxodon exploitation in the late middle pleistocene site of polledrara di cecanibbio (rome, italy). quaternary international, 406, 169-182. 58 cerilli e., fiore i. ms. received: may 6, 2018 final text received: may 18, 2018 available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 31 34 characteristics and potential application of holocene tidal inlets in the northern adriatic shelf (italy) livio ronchi 1 , alessandro fontana 1 , annamaria correggiari 2 1 dipartimento di geoscienze, università di padova, padova, italy 2 cnr-ismar istituto scienze marine, bologna, italy corresponding author: l. ronchi <livio.ronchi@gmail.com> abstract: in the last decades a series of offshore seismic and stratigraphic surveys revealed the presence of several infilled palaeo tidal inlets which punctuate the subsoil of the northern adriatic shelf. the morphologic, morphometric and sedimentary characteristics of these landforms constitute remarkable database for the reconstruction of palaeo coastline positions and to constrain the post-lgm sealevel rise, especially during the beginning of the holocene period. this work provides a first overview on the significance of the adriatic tidal inlets and their response to the interplay between upstream and downstream controls. keywords: holocene, sea-level rise, palaeo tidal inlets 1. introduction the constant adjustment and refining of the models predicting past sea-level position necessitate a continuous improvement and widening of sea-level indicators databases, which are essential for the calibration of the geophysical models (cf. vacchi et al., 2016; roy & peltier, 2018; stocchi et al., 2018). the peculiar low gradient (~0.4‰) that characterises the northern adriatic shelf made it extremely sensible to the eustatic variations, as even small increments of the sea level would have caused the drowning of large areas of the shelf. therefore, the transgressive record of the northern adriatic potentially represents an ideal environment for the reconstruction of a detailed post-lgm relative­ sea-level rise curve. the configuration of the northern adriatic shelf promoted the deposition of relatively thin layers of transgressive deposits which were dismantled after their drowning due to the wave effect of the rising sea (cattaneo & steel, 2003; fig. 1). thus, one of the few available indicators is represented by the tidal inlets, as their depth promoted their conservation within the stratigraphic record. these relict landforms could represent privileged spots for reconstructing timing and modes of the last marine transgression, before 7.5 ka bp, when the rate of sea-level rise was fast, since they are one of the few available, and sometimes almost continuous, sedimentary record of that period. this work offers a preliminary analysis of the tidal inlets on the scale of the whole northern adriatic and, in particular, it focuses on their evolution and significance in a sea-level and coastline reconstruction perspective. 2. material and methods the entire northern adriatic area has been investigated with more than 1000 chirp profiles (compressed high intensity radar pulse), for a total length of more than 12,300 km. all the chirp profiles analysed in this work were collected during the oceanographic campaigns named cm92, cm95, ve04, ve05, ri09, nad12 and asci14, which were organized by the cnr-ismar institute of bologna. these seismic lines were acquired in water depths ranging from -10 and -45 m mean sea level (msl). the collected data have a vertical resolution in the order of ca. 50 cm. along with the seismic data, several cores were analysed in order to provide ground truth for the interpretation and to obtain radiocarbon dates and micropalaeontological data. the available literature provided several additional sedimentary, palaeontological and chronological constrains that were integrated in our analysis (cf. correggiari et al., 1996; trincardi & argnani, 2001; trincardi et al., 2011, storms et al., 2008; moscon et al., 2015). 3. results more than 100 points with evidence of past tidal inlets were recognized on the italian side of the northern adriatic shelf (fig. 1). the morphometric characteristics and stratigraphic positions of all these landforms were stored in a database. the analysed tidal inlets show a wide range of dimensions: the thickness of their infilling spans from few to nearly 20 metres, their length can reach ca. 5 km, but normally its smaller than 1 km and their width can reach up to 400 m. a complete morphometric characterization is not possible for all the analysed features, as most of them were intercepted only by one or few chirp lines, but at least in two cases, which are being studied in detail, we have enough data to produce a detailed reconstruction of the palaeotopography of the inlets (fig. 2). the analysis of the position of the upper portion of all the tidal inlets indicate the presence of a clustering at the level of the entire northern adriatic https://doi.org/10.26382/aiqua.2018.aiquaconference shelf, with several cases localized at ca. -13 m, -24 m, 27 m and in the range between -30 and -34 m msl. 4. discussion 4.1 transgressive tidal inlet evolution in order to produce palaeo-environment reconstructions it is necessary to clearly understand the evolution of these landforms. in the study area, modern analogous systems are available for comparison purposes, as the conditions of sea-level rise rate and geometry of the continental shelf are not available in the present. the presence of groups of palaeo tidal inlets at clustered depths suggests the recurrent arising of conditions suitable for the development of lagoon-barrier complexes. these conditions may have different origin and controls. for example, climatic oscillations may have induced a temporary and general decreasing of the sea-level rise rate on a global or basin scale. these conditions have to be evaluated also in the framework of the palaeogeography and palaeoenvironmental evolution of the different areas, as the growing or waning of a lagoon complex may have been the result of a localized upstream river shifting. except for few cases (cf. storms et al., 2008, moscon et al., 2015), the analysis of the chirps highlighted the common absence of preserved barrier complexes. these landforms were usually erased along with the backbarrier basins after the overstepping of the lagoon system. the obliteration of these features from the stratigraphic record enhance the value of the tidal inlets, which, with their depth and infilling record, stand as one of the only witnesses of the post-lgm transgression in this area. it is likely that during a marine transgressive phase, tidal inlets are subjected to a rapid evolution due to the continuous forcing exerted by the rising sea. no large mobility of the inlet is expected in such dynamic environment, as the data collected so far suggest that the scouring and infilling phases of these landforms took place in the time frame of few centuries (ronchi et al., submitted). the sea-level rise recurrently induced the landward migration of backbarrier areas, which lead to periodic phases of tidal inlets abandonment and barrier complexes demolition. in particular, the abandonment and 32 fig. 1 geological map of the northern adriatic area. the red rectangles indicate the areas where the tidal inlets are mainly concentrated. the red star indicates the position of the inlet reconstructed in fig. 2. ronchi l. et al. 33 submersion of an older lagoon in favour of a new inner lagoon would led to the deactivation of the tidal inlets and their consequent infilling guided by the progressive decrease of the tidal flow running through the inlet. 4.2 sea-level rise reconstruction in the light of the previous reconstruction, it must be noticed that any radiocarbon date obtained on organic samples from the filling of an inlet, must be accurately evaluated in order to understand its real meaning. the easiest case would be to obtain a date from a lateral accretion bar within the infilling, considering that the lateral migration of an inlet would take place before the beginning of its deactivation. this kind of date would be indicative for reconstructing the sea-level rise curve, supposing to know the exact depth of the tidal inlet top. unfortunately, the analysed transgressive inlets are usually filled by draping layers as time and equilibrium conditions for the lateral or landward migration of these landforms were usually lacking. in this second case, in order to obtain an age for the peak of activity, the sample must be collected from the very bottom of the infilling sequence, therefore before the deactivation and blanketing of the inlet began. this evaluation must also take into account the provenance of the organic sample and the possible origin from a previous deposit eroded in the upstream catchment of the lagoon or during the scouring of the tidal inlet. 4.3 palaeo coastline reconstruction the presence of tidal inlets is also a clear indicator for the reconstruction of the position of the coastline. by their subdivision in clusters of depth it is possible to delineate the seaward limits of a series of barrier-lagoon complexes along palaeo coasts. the presence of more than one tidal inlets at the same depth and within the same region may allow to delineate, with a good approximation, the coastline position over a wide area. such reconstruction needs a careful evaluation of the stratigraphy of the area in order to correctly attribute different tidal inlets to the same coastline as the top of these landforms are usually subjected to the ravinement erosion, which can affect up to 6 m of their upper stratigraphy (cf. rieu et al., 2005). the internal geometry of the infilling of most of the analyzed tidal inlets suggest that the upper portion removal was usually small in the adriatic area, and probably never greater than 2 m. holocene tidal inlets of the northern adriatic shelf fig. 2 upper portion: example of tidal inlet cross section visible in a chirp profile. lower portion: reconstruction of the planform of the tidal inlet. the black line indicates the position of the chirp profile. after ronchi et al. (submitted). 5. conclusion the analysis of the palaeo tidal inlets constitutes an innovative tool for the reconstruction of the palaeogeography, palaeoenvironment and sea-level rise history of the post-lgm transgression. the case of the northern adriatic represents a perfect test area for this method. more than 100 specimens of palaeo tidal inlets were recognized and analysed. this allowed the preliminary definition of at least four main phases of relative decrease in the sea-level rise rate. the interpretation of the obtained data must be preceded by a site-specific stratigraphic analysis in order to infer the correct palaeogeographic and chronologic information. references amorosi a., pacifico a., rossi v., ruberti d. (2012) late quaternary incision and deposition in an active volcanic setting: the volturno valley fill, southern italy. sedimentary geology, 242, 307-320. cattaneo a., steel r.j. (2003) transgressive deposits: a review of their variability. earth-science reviews, 62, 187-228. correggiari a., roveri m., trincardi f. (1996) late pleistocene and holocene evolution of the north adriatic sea. il quaternario italian journal of quaternary sciences, 9, 697-704. moscon g., correggiari a., stefani c., fontana a., remia a. (2015) very-high resolution analysis of a transgressive deposit in the northern adriatic sea (italy). alpine and mediterranean quaternary 28, 121-129. rieu r., van heteren s., van der spek a. j. f., de boer p.l. (2005) development and preservation of a mid-holocene tidal-channel network offshore the western netherlands. journal of sedimentary research, 75, 409-419. ronchi l., fontana a., correggiari a., asioli a. (submitted) late quaternary incised and infilled landforms in the shelf of the northern adriatic sea (italy). marine geology. roy k., peltier w.r. (2018) relative sea level in the western mediterranean basin: a regional test of the ice-7g_na (vm7) model and a constraint on late holocene antarctic deglaciation. quaternary science reviews, 183, 76-87. stocchi p., vacchi m., lorscheid t., de boer b., simms a.r., van de wal r.s.w., vermeersen b.l.a., pappalardo m., rovere a. (2018) mis 5e relative sea-level changes in the mediterranean sea: contribution of isostatic disequilibrium. quaternary science reviews, 185, 122-134. storms j.e.a., weltje g.j., terra g.j., cattaneo a., trincardi a. (2008) coastal dynamics under conditions of rapid sea-level rise: late pleistocene to early holocene evolution of barrier-lagoon systems on the northern adriatic shelf (italy). quaternary science reviews, 27, 1107-1123. trincardi f., argnani a. (2001) note illustrative della carta geologica d’italia alla scala 1:250,000 – foglio nl33-10 “ravenna”. ispra servizio geologico d’italia. trincardi f., argnani a., correggiari a. (2011) note illustrative della carta geologica d’italia alla scala 1:250,000 foglio nl33-7 “venezia”, ispra servizio geologico d’italia. vacchi m., marriner n., morhange c., spada g., fontana a., rovere a. (2016) multiproxy assessment of holocene relative sea-level changes in the western mediterranean: variability in the sea-level histories and redefinition of the isostatic signal. earth science reviews, 155, 172-197. 34 ronchi l. et al. ms. received: may 7, 2018 final text received: may 21, 2018 amq abs sechi et al saccom 189-192.pub available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 189 192 luminescence dating of a middle late holocene lower shoreface, sw sardinia (italy) daniele sechi 1, stefano andreucci 2, giovanni de giudici 2, vincenzo pascucci 1 1 università degli studi di sassari, dipartimento di architettura design urbanistica, alghero, sassari, italy 2 università di cagliari, dipartimento di scienze chimiche e geologiche, cagliari, italy corresponding author: d. sechi <dasechi@uniss.it> abstract: geochronological framework of middle-late holocene coastal succession are usually based on radiocarbon dating method. homolithic sandy bodies characterize lower shoreface deposits and shells are often the only readily available biogenic materials for radiocarbon dating. however, multiple processes of erosion and deposition frequently affect sediment-grains and biological materials. as a consequence, 14c dating performed on shells often may under or overestimate the true age of the hosting deposits. this study highlights that luminescence dating is better suited to investigate sedimentary body formed in high energetic environments because directly dates the age of the final burial event. moreover, combining the quartz and k-feldspar derived ages a more robust dataset and internal independent age controls can be provided. keywords: sar-osl, pirir150, geochronology, radiocarbon dating, “old shell” problem 1. introduction in the last decade luminescence has become one of the most used method for dating siliciclastic-rich quaternary deposits (pascucci et al., 2014). nevertheless, its application is usually limited to the pleistocene while radiocarbon method is chosen for dating holocene successions (pascucci et al., 2014; 2018). in particular, 14c method is widely applied in shallow marine-coastal studies throughout the world but precise dating of lower shoreface deposits remains a major task. shoreface deposits of wave-dominated system are characterized by homolithic sandy bodies transported basinward from the coastline by return flows induced by major storms. in this highly energetic environment, shells are usually the only readily available biogenic materials for radiocarbon dating. however, shells may suffer of multiple reworking processes prior the final burial event and thus 14c may overestimates the ages of storm beds producing stratigraphic discrepancies. to overcome this problem an alternative or independent geochronological approach is needed. luminescence methods date the time elapsed since siliciclastic minerals (quartz and feldspar) were last exposed to day-light and thus directly provide the age of the final burial event (madsen & murray, 2009). aim of this work is therefore to provide a luminescence-based chronological framework for a middle-late holocene shoreface succession and compare with published radiocarbon ages provided by romano et al. (2017). moreover, luminescence ages will be provided using three different protocols such as sar-osl on quartz mineral along with ir50 and pirir150 on kfeldspar grains (madsen & murray, 2009; reimann t. & tsukamoto 2012). although these protocols share some common features, they also have their own specific traits and can be considered independent from each-other and thus used for age comparisons. 2. material and methods cala domestica (sw sardinia, italy; fig. 1) is a narrow 100 m wide and 450 m long bay carved in the lower cambrian meta sandstone and dolostones. it is characterized by a well-developed sandy pocket beach backed by an active dunefield system (fig. 1). the sediments nourishing the system are mainly bioclastic materials transported onshore from sea grass meadows during storms and minor siliciclastic grains carried by nw/se longshore current and/or by the seasonal riu guttu stream (fig.1). samples for luminescence and shells for 14c were collected from a 3-m long sediment core drilled in the shoreface (-13m below the present-day sea level). the sediment core was taken throughout opaque cylindrical plastic tube in order to avoid exposition of sediments to day-light and then opened under red subdued light. from the studied core two marine shells s1 and s5 were collected and the derived calibrated before present (bp) radiocarbon ages are already published by romano et al. (2017). a total of six luminescence samples were collected on the same core (fig.2). in particular iso0 at the very top, iso1 and iso5 at the same position of the shells collected for 14c and the remnant samples (iso2, iso3, iso4) every ~50 cm. all samples underwent chemical treatment at the sassari luminescence laboratory to isolate the 180-90 φm pure fraction of quartz and kfeldspar grains. single aliquot regenerative protocol (sar) for quartz and infra-red stimulation at 50 °c (ir50) along with post infra-red, infra-red stimulation at low https://doi.org/10.26382/aiqua.2018.aiquaconference 190 sechi d. et al. tab.1 summary of quartz luminescence dating results. table reports sample code and depth of sampling. for each mineral dosimeter chosen for luminescence dating, the luminescence protocol/signal used are reported with the estimated burial palaeodose (de, gy), environmental dose rate (dr, gy/ka) and calculated final burial ages expressed in years (a) from present (ad 2017). fig.1 a) the studied area. a) location of sardinia island in the mediterranean region where it occupies a central position. the map of sardinia, reported the main cities (black circles). the red square highlight the position of studied area in the sw of island. b) main bedrock lithologies outcropping around the study area. c) satellite view of cala domestica bay with drilling station. 191 temperature 150 °c protocols (pirir150) on k-feldspars were applied for luminescence burial palaeodose (de) measurements (madsen & murray, 2009; reimann t. & tsukamoto, 2012). enviromental dose rate (dr) calculations corrected for cosmic rays and water content contributions are based on high resolution gamma spectrometer. 3. results table 1 reports luminescence dataset for the collected samples (fig. 2). quartz and k-feldspar signals pass all laboratory tests. these provide very good results for the three main reliability check-criteria: recycling, recuperation and dose recovery. quartz (oslsar) and feldspar (ir50, pirir150) signals gave in average recycling ratios within the 10 % of unity and recuperation less than 5% of natural de. dose recovery ratios are all close unity, 1 ±0.02 (sar-osl), 1.00±0.01 (ir50) and 0.96 ±0.02 (pirir150). these data confirm the suitability of protocols and dosimeters chosen for dating the sediment of cala domestica. given that k-feldspar suffers of fading (partial loss of signal recovered throughout the time) the g-value (% of loss per decade) was tested. the ir50 and pirir150 show an average fading ratio respectively of 3.86 and 0.89 %/dec. and thus used for correcting final feldspar ages. quartz sar -osl yield ages ranging from the bottom up of 4800±300 to 540±50 a. feldspar ir50 and pirir150 show ages respectively from 4217±87 and 4347±133 a to 403±12 and 433±41 a (tab.1). 3. discussion and conclusion three meters of holocene core collected on shallow marine (lower shoreface) deposits, far off cala domestica bay, is dated using luminescence and 14c methods. this study sheds a light on strenghths and weaknesses of these two approaches. figure 2 compares the three sets of luminescence dating (sar, ir50 and pirir150) with the radiocarbon ages. estimated luminescence ages using the two mineral dosimeter (quartz and feldspar) and different luminescence signals are in stratigraphic order downward the core. the reliability of estimated palaeodose and ages is supported by the pretest results. the uppermost sample (iso0) yield null or small residual palaeodose for the three protocols applied. this suggests that all different luminescence signals are being well zeroed by day-light at depth of 13 m. moreover, consistency and increasing of the ages downward confirm that mineral dosimeters well recover the palaeodose (burial time) elapsed from the last exposition and allow to exclude the presence of partial bleached inherit signal issue (incomplete zeroing). although, sar-osl ages slightly overestimate the ir50 and pirir150 ones, these agree each-other within 1 sigma uncertainties. in particular, kfeldspar-derived ages obtained for iso5 (bottom of core) confirm the 14c age of 4435-4290 cal bp (romano et al., 2017). the fading rates obtained for pirir150 are significantly lower than those form ir50 (tab.1) suggesting the better stability of pirir150 signal over time and the potential of the protocol for dating recent to very recent sedimentary bodies. the iso1 sample shows luminescence ages consistently younger than 960-860 cal bp 14c (fig. 2). this ca. 500 a discrepancy between luminescence and 14c ages most likely is due to the multiple reworking processes that shells and sediment-grains suffering in the luminescence dating of a middle late holocene lower shoreface, sw sardinia fig. 2 on the right the stratigraphic reconstruction of drilled core and position of radiocarbon and luminescence samples collected. the radiocarbon ages (romano et al., 2017) are reported against the estimated sar, ir50 pirir150 luminescence ages. on the left, the plot of geochemical enrichment factor (ef) along the core depth published by romano (2017). only element anthropogenically enriched (ef>1.5) are reported. shoreface environment. in particular, shells may be temporarily stored in the foreshore part of the beach system prior to be finally buried in the lower shoreface as a consequence of major storms. the anthropogenically enriched elements (hg, pb and zn) measured along the studied core by romano et al. (2017) show a strong enrichment in the first 20 cm of the core clearly referable to the recent mine activity (fig. 2). whereas based on the 14c available age a small peak observed at ca. 60 cm were associated as well with ore exploitations in pre-industrial times but with no possibility to refer this activity to the phoenician, romans, pisans or middle ages. however, luminescence ages point the first peak to a post-romans ore exploitations better constraining the mining activity at the study area. the carried out study highlights that in highly energetic environments such as lower shoreface multiple reworking processes frequently affect sediment-grains and biological materials. as a consequence of this, 14c dating performed on shells might under or overestimate the final burial age of the host deposits. therefore, luminescence dating is better suited to investigate homolithic sedimentary body because it directly dates the mineral grains sun-exposition, transport and accumulation history. moreover, using different luminescence signals and dosimeters allow to have a better knowledgement of sedimentary depositional history and internal independent age controls. references madsen a.t., murray a.s. (2009) optically stimulated luminescence dating of young sediments: a review. geomorphology, 109, 3-16. pascucci v., de falco g., del vais c., sanna i., melis r.t., andreucci s. (2018) climate changes and human impact on the mistras coastal barrier system (w sardinia, italy). marine geology, 395, 271284. pascucci v., sechi d., andreucci s. (2014) middle pleistocene to holocene coastal evolution of nw sardinia (mediterranean sea, italy). quat. int., 328 -329, 3-20. reimann t., tsukamoto s. (2012) dating the recent past (<500 years) by post-ir irsl feldsparexamples from the north sea and baltic sea coast. quaternary geochronology, 10, 180-187. romano e., de giudici g., bergamin l., andreucci s., maggi c., pierfranceschi g., magno m.c., ausili a. (2017) the marine sedimentary record of natural and anthropogenic contribution from the sulcisiglesiente mining district (sardinia, italy). marine pollution bulletin, 122(1-2), 331-343. 192 sechi d. et al. ms. received: may 6, 2018 final text received: may 14, 2018 amq abs pieruccini et al saccom 185-188.pub available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, abstracts, aiqa 13-14/06/2018 florence, 185 188 seqs-datestra a database of terrestrial quaternary stratigraphical sites of europe: inqua funded international focus group 1620f saccom pierluigi pieruccini 1, guzel danukalova 2, markus fiebig 3 1 dipartimento di scienze della terra, università di torino, torino, italy 2 institute of geology of the ufimian, ufa, russia 3 dep. civil engineering & natural hazards, inst. of applied geology, university of natural resources and life sciences, wien, austria corresponding author: p. pieruccini <pierluigi.pieruccini@unito.it> abstract: seqs for the 2016-2019 intercongress period aims to build a database of quaternary terrestrial european stratigraphic sites (datestra). datestra follows the need for a concise, informative and easy to use system to share as many information as possible about the most important quaternary sites across europe. the main goal is to create a database that summarize the litho-, bio-, pedo-, morpho and chrono-stratigraphical data becoming a tool for cross-border correlations of the main quaternary subdivisions in europe, combining existing knowledge and expertise of regional specialists. the main outcome expected is a database shared and made available to all the quaternary audience on open gis based web platforms to give to the wider audience as possible, also at informative level, the chance to have an overview of the european terrestrial quaternary setting. at the next inqua congress (2019 dublin, ireland), datestra ongoing works will be presented in a joint session with seqs. keywords: quaternary, stratigraphy, key-sites, geographic database, europe 1. introduction for the 2016-2019 inqua intercongress period, seqs (inqua section on european quaternary stratigraphy) will aim to build a database of terrestrial european stratigraphy (datestra). this is a database of the sites with stratigraphic importance from every country of europe. datestra is therefore an european geographic site-stratigraphical database that will continue the projects carried out by seqs during the previous intra-congress periods when the main goal of the activities was across-europe correlations (pieruccini et al., 2016a; 2017a). however, in many regions quaternary stratigraphical schemes were developed using complex litho-, chrono-, and bio-stratigraphical criteria that made problematic the correlations in terrestrial quaternary systems. this is also due to the fragmentary nature of these records and to the problems related to reliable dating techniques covering the full range of quaternary time. terminology defining the chronostratigraphical setting is often based on local or oldfashioned schemes and the need for a common language/terminology/methodology is strongly necessary in order to share among european quaternary scientists basic geoscientific information. datestra will summarize the main sites with terrestrial quaternary deposits in europe trying to bypass their fragmentary nature and giving rapid access to the sections, techniques and methods used for their study. in order to set the regional names and subdivisions avoiding as much as possible the problems due to local terminology, datestra will focus on the main quaternary stages as assessed by ics-international commission on stratigraphy (gelasian; calabrian; middle pleistocene; upper pleistocene; holocene) giving particular emphasis on the stage boundaries and transitions. this approach should give a summary and overview of the main characters of the subseries/stages across europe. datestra aims to summarize the litho-, bio-, pedo-, morphoand chrono-stratigraphical data that are fundamental for cross-border correlations, quaternary mapping, climate changes reconstructions and natural hazards and related risks assessment. moreover, creation of shared database is also among the main topics of horizon 2020, the financial instrument implementing the innovation union-europe 2020 flagship initiatives aimed at securing europe's global competitiveness. the whole network of quaternary scientists is warmly invited to participate to datestra under the umbrella of inquaseqs; seqs is active since many decades, putting together a high number of quaternary scientists across europe sharing knowledge and information annually through meetings and regular publication of proceedings of these meetings on quaternary international special issues (i.e. zastrozhnov et al., 2018). at the same time, ecr (early career researchers) and dcr (developing countries researchers) scientists are encouraged and granted to present and share during the seqs annual meetings the main quaternary sites, together with their significance, for single countries or regions across europe. in fact, during the seqs meetings, sessions are devoted to datestra and the whole seqs audience is https://doi.org/10.26382/aiqua.2018.aiquaconference informed about the future actions to be taken (http:// datestra-seqs.strikingly.com/) (pieruccini et al., 2016a; 2017a). the seqs meetings in 2016 (armenia) and 2017 (france) already recorded contributions by different countries of europe (danukalova et al., 2017a and b; marks, 2017; gerasimenko, 2017; lefort et al., 2017; korsakova & kolka, 2017; pieruccini et al., 2016b; 2017b) 2. structure of the database the the password for the database is easy; it means easy compilation, the compilers are invited to contribute providing basic information for each site, including basic bibliographic reference. the database should serve to the end-user as a starting point for further and more detailed information. at first, datestra should contain only key sites, such as historically known sites or the better stratigraphically significant and constrained sites from every country of europe. the database should also be easy to query; the enduser should be able to query and find the information needed, i.e. the chronostratigraphical interval and the dating method, the biostratigraphical proxy etc. the structure of the database is therefore conceived taking into account these objectives. each site has a number of attributes (and related domains) and each attribute has a limited number of values, in order to make the database as simpler as possible. the terminology of the values for each attribute have been uniformed based on the iquame 2500 project dictionaries for the quaternary map of europe. the attributes are grouped under 4 main topics: 1 registry these attributes are related to the basic information about name of the site, country, region, geographic coordinates, names and institutions of compilers, date of compilation, type of site, state of preservation of the site. 2 stratigraphy these attributes are related to the basic information about the chronostratigraphical attribution, geochronological method for attribution, reliability of the attribution, depositional environment, presence of unconformities, biological proxies, morphostratigraphy, lithostratigraphy, pedostratigraphy and magnetostratigraphy. 3 correlation these attributes are related to the correlation of the site with climatostratigraphy or mis. the mis attribution is provided for mis intevals as follows: mis 1-19, if single; mis1-19, 19-31, 31-65, 63-103 if intervals of mis. 4 documents these attributes are related to the documents, and their path, attached to the table of the site, i.e. article, photo, table, log etc. the structure and design of the database was ini 186 pieruccini p. et al. fig. 1 scheme of the structure of datestra database with the description of the attributes for each site. tially discussed among colleagues belonging to the aiqua community (italian association for quaternary research) who also contributed with a preliminary compilation of italian quaternary sites. then, these sites and the output on story maps (esri©) were presented to the seqs community (pieruccini et al., 2016c; 2017c). 3. datestra output and expected result the main output of datestra is an open access database with a consistent number of quaternary sites compiled for as many countries as possible of europe. the database will be an open-source tool that will works as a starting point for the european quaternary stratigraphy knowledge, to be implemented and updated by scientists that especially in the future could face problems with old terminology or old references about key-sites that in many cases disappeared or faded away in the memory. the database principles are that it must be: a) concise, containing very basic information but sufficient as starting point for further refined search; b) easy to compile, allowing with few and clear rules its compilation from people with different scientific backgrounds: c) easy to query, this is the crucial point for consultation and correlation across europe. for each compiled site the compilers are asked to provide the table with attributes and values, a short text, few picture and the main references. the sites and related data will also be uploaded on web-gis application like “story maps” (esri©) that allows all the queries in order to give a summary of the potentially correlated quaternary sites across europe. the goal for this intra-congress period is then to present the database at inqua dublin 2019, to the wider audience as possible, opening the road to future actions like extra-european countries or more detailed or functional databases. for this purpose, seqs already applied for a session also dedicated to datestra. references danukalova g., osipova e., yakovlev a., kurmanov r. (2017a) biostratigraphy of the early pleistocene (paleopleistocene) of the southern urals region, russia. seqs2017 meeting, tautavel (france) 10-15 sept. 2017: “quaternary stratigraphy and hominids around europe: tautavel (eastern pyrenees)”. abstract volume, 37. institute of geology, ufimian scientific centre, russian academy of sciences. danukalova g., osipova e., yakovlev a., kurmanov r. (2017b) middle, upper pleistocene (neo pleistocene) and holocene key-sites of the southern uralian region (russia): summary for the database. seqs2017 meeting, tautavel (france) 1015 sept. 2017. “quaternary stratigraphy and hominids around europe: tautavel (eastern pyrenees)”. abstract volume, 42. institute of geology, ufimian scientific centre, russian academy of sciences. gerasimenko n. (2017) the ukrainian candidate sections for datestra. seqs2017 meeting, tautavel (france) 10-15 sept. 2017: “quaternary stratigraphy and hominids around europe: tautavel (eastern pyrenees)”. abstract volume, 65. institute of geology, ufimian scientific centre, russian academy of sciences. korsakova o., kolka v. (2017) pleistocene stratigraphy and key-sections in kola peninsula, north west russia. available data. seqs2017 meeting, tautavel (france) 10-15 sept. 2017: “quaternary stratigraphy and hominids around europe: tautavel (eastern pyrenees)”. abstract volume, 63. institute of geology, ufimian scientific centre, russian academy of sciences. lefort j., danukalova g., monnier j. (2017) datestra in brittany and normandy. the predatestra correlations and other transeuropean considerations. seqs2017 meeting, tautavel (france) 10-15 sept. 2017: “quaternary stratigraphy and hominids around europe: tautavel (eastern pyrenees)”. abstract volume, 51. institute of geology, ufimian scientific centre, russian academy of sciences marks l. (2017) proposal of polish key sites to the data base of the quaternary stratigraphy of europe. seqs2017 meeting, tautavel (france) 10 -15 sept. 2017: “quaternary stratigraphy and hominids around europe: tautavel (eastern pyrenees)”. abstract volume, 50. institute of geology, ufimian scientific centre, russian academy of sciences. pieruccini p., fiebig m., danukalova g. (2016a) ifg 1612f datestra, a database of terrestrial european stratigraphy. quaternary perspectives, 23 (2), 7-8. pieruccini p., fiebig m., danukalova g. (2016b) datestra: a database of terrestrial european stratigraphy (inqua grant 1612f). seqs2016 meeting, yerevan, armenia 3-10 settembre 2016: “bridging europe and asia: quaternary stratigraphy and paleolithic human occupation in armenia and southern georgia, fiebig m., meliksetian k., gasparyan b., arakelyan d. (eds) abstract volume, p. 40. pieruccini p., bertini a., coltorti m., magri d., martinetto e., palombo m., ravazzi c. (2016c) datestra, a database of terrestrial european stratigraphy (inqua grant 1612f): the example of selected sites from italy. seqs2016 meeting, yerevan, armenia 3-10 settembre 2016 “bridging europe and asia: quaternary stratigraphy and paleolithic human occupation in armenia and southern georgia, fiebig m., meliksetian k., gasparyan b., arakelyan d. (eds) abstract volume, p. 54. pieruccini p., fiebig m., danukalova g. (2017a) 1612f datestra: a database of terrestrial european stratigraphy. quaternary perspectives, 24 (1), 1011. pieruccini p., danukalova g., fiebig m. (2017b) datestra: a database of terrestrial european stratigraphy (inqua funded focus group saccom: 1612f). in: seqs2017 meeting, tautavel (france) 10-15 sept. 2017: “quaternary stratigraphy and 187 datestra database of terrestrial quaternary sites of europe hominids around europe: tautavel (eastern pyrenees)”. abstract volume, 40. institute of geology, ufimian scientific centre, russian academy of sciences. pieruccini p., bertini a., coltorti m., magri d., palombo m.r., ravazzi c., sala b. (2017c) the italian contribution to the datestra project (inqua funded focus group saccom: 1612f): a first compilation of the main italian quaternary sites. seqs2017 meeting, tautavel (france) 10-15 sept. 2017: “quaternary stratigraphy and hominids around europe: tautavel (eastern pyrenees)”. abstract volume, 41. institute of geology, ufimian scientific centre, russian academy of sciences. 188 pieruccini p. et al. ms. received: may 8, 2018 final text received: may 14, 2018 available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 99 103 extinction and paleoecology of the late pleistocene cave bear from northeastern italy: radiocarbon and stable isotope evidence gabriele terlato 1,2 , hervé bocherens 3,4 , matteo romandini 5 , nicola nannini 1,6, keith a. hobson 7 , marco peresani 1 1 dipartimento di studi umanistici, sezione di scienze preistoriche e antropologiche, università degli studi di ferrara, ferrara, italy 2 area de prehistoria, universitat rovira i virgili (urv), tarragona, spain 3 department of geosciences, biogeology, university of tübingen, tübingen, germany 4 senckenberg centre for human evolution and paleoenvironment (hep), university of tübingen, tübingen, germany 5 dipartimento di beni culturali, università di bologna, ravenna, italy 6 muse museo delle scienze, trento, italy 7 department of biology, western university, biological and geological sciences building, london, ontario, canada corresponding author: g. terlato <trlgrl@unife.it> abstract: we present here the chronometric, isotopic and taphonomic evidence of cave bear from three palaeolithic sites in northeastern italy: paina, trene and buso doppio del broion (berici hills vicenza). two direct radiocarbon dates yielded an age around 24 ka bp, which make these remains the latest known representatives of the species in europe and confirmed that demise of cave bear falls during the lgm. the carbon and nitrogen isotopic values of bone collagen do not show any marked ecological change since 33 ka bp, suggesting an essential vegetarian diet. several bear bones preserved traces of human modification such as cut marks, which enables a reconstruction of the main steps of butchering process. keywords: cave bear, extinction, palaeoecology, cave bear hunting, northeast italy 1. introduction the late quaternary witnessed extinction of large mammals in europe. the course and the timing of these events differ from region to region and the causes of these extinctions are the subject of an on-going debate (barnosky et al., 2004; lorenzen et al., 2011; sandom et al., 2014 stuart, 2015). in any case, a better understanding of the mechanisms that led to extinction of several large mammal species in a context of climate instability and changing human impact on the ecosystems will have implications for anticipating possible future extinctions. the cave bear (ursus spelaeus sensu lato) is an interesting species to focus upon because has possibly yielded the largest amount of fossil remains in late pleistocene caves in europe, with a large part associated with human deposits. cave bear bones are often associated with stone tools or with other evidence of human presence, possible interactions between the two species. radiocarbon dating suggests that they went extinct simultaneously in different parts of europe about 25-28 ka bp, close to the onset of the last glacial maximum (lgm) during mis 2 (adams, 2002; hofreiter et al., 2004; wojtal, 2007; blant et al., 2010; münzel et al., 2011; bocherens et al., 2014; martini et al., 2014; sabol et al., 2014; baca et al., 2016). understanding feeding habits of cave bear is essential as it might give insight into those factors contributing to their extinction: whether they were strictly herbivores or more flexible omnivores could have resulted in different scenarios, whereby the relative influence of climate change, human pressure could have played different roles (pacher & stuart, 2009; bocherens et al., 2014a). in this context, herbivorous feeding habits inferred from tooth, skull and jaw morphology (kurté, 1976; münzel et al., 2014; van heteren et al., 2016) as well as the stable isotopic composition of cave bear collagen from a large majority of european sites, ranging from spain to romania, indicate an essentially vegetarian diet (bocherens et al., 1997; 2006; 2011; 2014; vila taboada et al., 1999; grandal-d’anglade et al., 2011; münzel et al., 2011; horacek et al., 2012; pacher et al., 2012; krajcarz et al., 2016; naito et al., 2016). in contrast, δ13c and δ15n analyses on cave bears from two romanian sites (richards et al., 2008; robu et al., 2013) suggested that some cave bears included a substantial amount of meat in their diet. in this present work, we report the results of such investigation carried out on cave bear bones from three sites: paina cave, trene cave and buso doppio del broion (berici hills vicenza), part of them recently published (terlato et al., 2018). we applied to these bones some techniques that allow us to fit these specimens into a chronological and ecological context and yield further information that help to understand the extinction process of cave bear in this area of the southern alps. 2. material and methods paina cave (units 5 and 6), trene cave (macro-unit b) and buso doppio del broion (units 1and 2) are located in berici hills in northeastern italy. taxonomic, skeletal identifications and preliminary taphonomic analysis of bones assemblage have been conducted and published by nannini and romandini (2015) and terlato et al. (2018). for stable isotope analysis, 49 cave bear https://doi.org/10.26382/aiqua.2018.aiquaconference bones were selected. in addition, 6 moose alces alces bones from the same sites and units were sampled. the δ 13c and δ15n values as well as c:n atomic ratio of bone collagen for 12 bear samples and 4 moose samples from paina and trene caves have already been published in a previous study (terlato et al., 2018). the collagen extraction was performed following bocherens et al. (1997) at biogeology unit of the geoscience department at the university of tübingen (germany). c and n elemental and stable isotope measurements were performed at the lsis-afar stable isotope facility of the university of western university (canada). collagen samples (0.5mg) were weighed into tin capsules and combusted in a costech elemental analyzer coupled to a thermo delta plus xl isotope ratio mass spectrometer operated in continuous flow mode, with helium carrier gas. two standards, usgs-40 and usgs -41 were included for every ten samples and two internal laboratory standards were included to monitor instrument drift and provide a check on accuracy over the course of each analytical session. values of δ 13c were calibrated to vpdb and values of δ15n were calibrated to air. measurement error was ±0.1 ‰ for δ 13c, and ±0.2 ‰ for δ15n. 100 fig. 1 (a) position of the palaeolithic caves in the berici hills considered in this work; (b) localization and details of anthropic traces; (c) δ13c and δ15n values of cave bear and moose. terlato g. et al. 101 3. results taphonomic analysis on cave bear bones from trene cave and buso doppio del broion has revealed human modification traces like cut marks on several skeletal elements, which enables a reconstruction of the main steps of hide recovery and the butchering process (fig. 1). at trene cave cut marks caused by skinning are present on three mandibles of different individuals. a right calcaneus and a third metacarpal show short cut marks, which are sometimes deep and persistent, attesting the early phases of hide recovery or disarticulation. evidence of defleshing and detachment of muscle mass is evident on a right humerus, on a right fibula and on a left radius for which skinning is not excluded. a percussion mark is visible only on a portion of mandible completely burned suggesting a fracturing action in order to extract the marrow and use the same remain as fuel (terlato et al., 2018). at buso doppio del broion traces are around one rib, which refer to defleshing. the cut marks on the metatarsal certainly indicate skinning of the bear. at paina cave, evidence for bear exploitation by humans are rare. this cave may have been rarely inhabited by human groups, while it was repeatedly occupied and for a long time by cave bears, during hibernation and cub nursing (terlato et al., 2018). in all three sites the c:n ratios, %n and %c demonstrated the very good quality of collagen preservation. the δ13c values on cave bear ranged from -22.2‰ to -20‰ (paina cave), from -21.2‰ to -19.6‰ (trene cave) and from -21.0‰ to -19.9‰ (buso doppio del broion). the δ 15n on cave bear ranged from 1.5‰ to 7.2‰ (paina cave), from 2.1‰ to 5.4‰ (trene cave) and from 1.6‰ to 6.6‰. the δ13c and δ15n values measured for alces alces ranged from -20.2‰ to -19.5‰ and from 2.0‰ to 5.4‰ (fig.1). the ranges of δ13c and δ15n values overlap considerably for adult bones of cave bears and moose. there are a few exceptions to this pattern: one tooth and one mandible of young individuals from paina cave with high δ15n and low δ13c values (terlato et al., 2018) and one tibia from buso doppio del broion with high δ15n and high δ13c values. three direct radiocarbon dates on well-preserved collagen were carried out and two of them yielded dates tightly clustered (tab.1). the conventional age of the phalanx from paina cave is determined as 19,686±54 14c bp (23,948 to 23,489 cal bp. sample eth-79366: terlato et al., 2018). the radiocarbon age of a humerus from trene cave is measured as 19,948±55 14c bp (24,220 to 23,795 cal bp. sample eth-79368: terlato et al., 2018). at buso doppio del broion the rib gave a conventional age as 29,001±123 14c bp (33,597 to 32,844 cal bp. sample eth-79367). 4. discussion and conclusion these dates on cave bear from paina and trene caves, around 24,200-23,500 cal bp, are more recent than others measured in europe and make it the latest known representative of the species. with these dates there is no doubt that the disappearance of cave bear from italy occurred during the lgm (terlato et al., 2018), more or less coinciding with the expansion of south alpine glaciers (monegato et al., 2017). as the glacial expansions fragmented the ranges of many animal and plant species throughout europe, the southern part of the prealps might have preserved isolated and sheltered refugia for cave bears. especially the berici hills represented a kind of refuge area for the plantigrade, with availability of trophic resources and shelters suitable to overcome harsh winter periods, relative to other zones in the lessini mountains or at higher altitude as in the alps (spötl et al., 2017). isotopic data of these cave bears are similar to other cave bear populations, with low δ15n values, in the range of herbivores (here alces alces) and lower δ13c values as ungulates, here again alces alces. this indicates that cave bears from berici hills did not differ in their dietary habits from the pattern of the species in western and central europe, an essential vegetarian diet (bocherens et al., 2011; 2014; münzel et al., 2011; pacher et al., 2012). however, the δ13c and δ15n values do not show any obvious ecological change since 33,000 cal bp (radiocarbon data of rib from buso doppio del broion) despite climatic fluctuations, suggesting a strong niche conservatism for this species, leading to a possible lack of ecological flexibility in the lgm. there are a few exceptions to this pattern. two specimens of young individuals from paina cave showed different δ 13c and δ15n values, that may be related to hibernation or nursing signals (terlato et al., 2018). only one specimen from buso doppio del broion has high δ15n and high δ13c values which reveals a more omnivore diet of a cave bear, if it will be confirmed by dna retrieving. the high δ 13c values of alces alces, suggest a relatively open environment, but with clearings available (drucker et al., 2010; terlato et al., 2018). a final though on cave bear bones from trene cave and buso doppio del broion concerns human exploitation for meat and hides may have had an impact on the demise of this species. this could possibly reveal continuity in the hunting and subsistence strategies between hunter-gatherers group tab. 1 radiocarbon dates of cave bear from paina cave, trene cave and buso doppio del broion calibrated. cave bear extinction in northeastern italy during a wide span of time, a situation that was probably not favourable to the survival of the species. we can speculate that the combination of climatic deterioration and increasing human pressure could be responsible to the extinction of cave bear in northern italy, and the final extinction of the species since this population seems to have been the last to survive. this scenario is unfortunately very similar to the situation of numerous mammal species nowadays. acknowledgments this research has been promoted and supported by the university of ferrara (far 2016), the veneto region, the mossano municipality and several public and private institutions (fondazione cariverona). we are grateful to dober chalal aldana, dorothée drucker, christoph wißing and susanne münzel (university of tübingen) for technical assistance in the preparation of the bone samples. blanca mora alvarez tessa plint and fred longstaffe assisted with stable isotope analyses performed in canada. references adams b. (2002) new radiocarbon dates from szeleta and istállóskő caves, hungary. praehistoria, 3, 5355. baca m., popović d., stefaniak k., marciszak a., urbanowski m., nadachowski a., mackiewicz p. (2016) retreat and extinction of the late pleistocene cave bear (ursus spelaeus sensu lato). the science of nature, 103 (92). barnosky a.d., koch p.l., feranec r.s., wing s.l., shabel a.b. (2004) assessing the causes of late pleistocene extinctions on the continents. science, 306, 70-75. blant m., bocherens h., bochud m., braillard l., constandache m., jutzet j.m. (2010) le gisement à faune würmienne du bärenloch: préalpes fribourgeoises, suisse. bulletin de la société fribourgeoise des sciences naturelles, 99, 149-170. bocherens h., billiou d., patou-mathis m., bonjean d., otte m., mariotti a. (1997) paleobiological implications of the isotopic signatures (13c, 15n) of fossil mammal collagen in scladina cave (sclayn, belgium). quaternary research, 48, 370-380. bocherens h., drucker d.g., billiou d., geneste j.m., van der plicht j. (2006) bears and humans in chauvet cave (vallon-pont-d’arc, ardèche, france): insights from stable isotopes and radiocarbon dating of bone collagen. journal of human evolution, 50, 370-376. bocherens h., stiller m., hobson k.a., pacher m., rabeder g., burns j.a., tütken t., hofreiter m. (2011) niche partitioning between two sympatric genetically distinct cave bears (ursus spelaeus and ursus ingressus) and brown bear (ursus arctos) from austria: isotopic evidence from fossil bones. quaternary international, 245, 238-248. bocherens h., bridault a., drucker d.g., hofreiter m., münzel s.c., stiller m., van der plicht j. (2014) the last of its kind? radiocarbon, ancient dna and stable isotope evidence from a late cave bear (ursus spelaeus rosenmüller, 1794) from rochedane (france). quaternary international, 339-340, 179-188. drucker d.g., hobson k.a., ouellet j.p., courtois r. (2010) influence of forage preferences and habitat use on 13c and 15n abundance in wild caribou (rangifer tarandus caribou) and moose (alces alces) from canada. isotopes in environmental and health studies, 46, 107-121. grandal-d’anglade a., pérez-rama m., fernándezmosquera d. (2011) diet, physiology and environment of the cave bear: a biogeochemical study. in: toskan b. (ed.), fragments of ice age environments. proceedings in honour of ivan turk’s jubilee 21. ljubljana, sloveniae: opera instituti archaeologici, 111-125. van heteren a.h., maclarnon a., rae t.c., soligo c. (2009) cave bears and their closest living relatives: a 3d geometric morphometrical approach to the functional morphology of the cave bear ursus spelaeus. slovenský kras acta carsologica slovaca, 47, 33-46. hofreiter m., serre d., roland n., rabeder g., nagel d., conard n., münzel s., pääbo s. (2004) lack of phylogeography in european mammals before the last glaciation. pnas, 10, 12963-12968. horacek m., frischauf c., pacher m., rabeder g. (2012) stable isotopic analyses of cave bear bones from the conturines cave (2800 m, south tyrol, italy). braunschweiger naturkundliche schriften, 11, 47-52. krajcarz m., pacher m., krajcarz m.t., laughlan l., rabeder g., sabol m., wojtal p., bocherens h. (2016) isotopic variability of cave bears (δ15n, δ13c) across europe during mis 3. quaternary science reviews, 131, 51-72. kurtén b. (1976) the cave bear story: life and death of a vanished animal. new york (ny): columbia university press, pp. 163. lorenzen e.d., nogués-bravo d., orlando l., weinstock j., binladen j., marske k.a., ugan a., borregaard m.k., gilbert m.t.p., nielsen r., et al. (2011) species-specific responses of late quaternary megafauna to climate and humans. nature, 479, 359-364. martini i., coltorti m., mazza p.p., rustioni m., sandrelli f. (2014) the latest ursus spelaeus in italy, a new contribution to the extinction chronology of the cave bear. quaternary research, 81, 117-124. monegato g., scardia g., hajdas i., rizzini f., picin a. (2017) the alpine lgm in the boreal ice-sheets game. nature scientific reports, 7, 2078. münzel s.c., stiller m., hofreiter m., mittnik a., conard n.j., bocherens h. (2011) pleistocene bears in the swabian jura (germany): genetic replacement, ecological displacement, extinctions and survival. quaternary international, 245, 1-13. münzel s.c., rivals f., pacher m., döppes d., rabeder g., conard n.j., bocherens h. (2014) behavioural ecology of late pleistocene bears (ursus spelaeus, ursus ingressus): insight from stable isotopes (c, n, o) and tooth microwear. quaternary international, 339-340, 148-163. 102 terlato g. et al. naito y., germonpré m., chikaraishi y., ohkouchi n., drucker d.g., hobson k.a., edwards m.a., wißing c., bocherens h. (2016) evidence for herbivorous cave bears (ursus spelaeus) in goyet cave, belgium: implications for palaeodietary reconstruction of fossil bears using amino acid δ 15n approaches. journal of quaternary science, 31, 598-606. nannini n., romandini m. (2015) gravettian and epigravettian hunters in the berici hills (vicenza): two cases of cave bear (ursus spelaeus) exploitation. in: thun hohenstein u., cangemi m., fiore i., de grossi manzorin j., (eds). atti del 7° convegno nazionale di archeozoologia. ferrara: annali università di ferrara 11, 29-38. pacher m., stuart a.j. (2009) extinction chronology and palaeobiology of the cave bear (ursus spelaeus). boreas, 38, 189-206. richards m.p., pacher m., stiller m., quilés j., hofreiter m., constantin s., zilhão j., trinkaus e. (2008) isotopic evidence for omnivory among european cave bears: late pleistocene ursus spelaeus from the peştera cu oase, romania. pnas, 105, 600604. robu m., fortin j.k., richards m.p., schwartz c.c., wynn j.g., robbins c.t., trinkaus e. (2013) isotopic evidence for dietary flexibility among european late pleistocene cave bears (ursus spelaeus). canadian journal of zoology, 91, 227234. sabol m., bendík a., grivalský m.m., lizák j., michlík i. (2014) latest and highest fossil record of cave bears (ursus ex gr. spelaeus) in slovakian western carpathians. quaternary international, 339340, 189-196. sandom, c., faurby, s., sandel, b., svenning, j.c. (2014) global late quaternary megafauna extinctions linked to humans, not climate change. proceedings of the royal society of london. biological sciences, 281, 20133254. spötl c., reimer p., rabeder g., bronk ramsey c. (2017) radiocarbon constraints on the age of the world’s highest-elevation cave-bear population, conturines cave (dolomites, northern italy). radiocarbon 1-9. stuart a.j. (2015) late quaternary megafaunal extinctions on the continents: a short review. geological journal, 50, 338-363. terlato g., bocherens h., romandini m., nannini n., hobson k.a., peresani m. (2018) chronological and isotopic data support a revision for the timing of cave bear extinction in mediterranean europe. historical biology. doi: 10.1080/08912963.2018.1448395. vila taboada m., fernandez mosquera d., lopez gonzalez f., grandal-d’anglade a., vidal romani j.r. (1999) paleoecological implications inferred from stable isotopic signatures (δ13c, δ15n) in bone collagen of ursus spelaeus ros. hein. cadernos lab xeoloxico de laxe, 24, 73-87. wojtal p. (2007) zooarchaeological studies of the late pleistocene sites in poland. institute of systematics and evolution of animals, polish academy of sciences, pp.189. 103 cave bear extinction in northeastern italy ms. received: may 4, 2018 final text received: may 15, 2018 104 base valutazione del tasso di erosione in appennino meridionale da dati geologico-geomorfologici andrea capalbo1, alessandra ascione2, pietro p.c. aucelli3, stefano mazzoli2 1dipartimento di scienze geologiche, tecnologie chimiche e ambientali, università “carlo bo”, urbino 2dipartimento di scienze della terra, università “federico ii”, napoli 3dipartimento di scienze per l'ambiente, università “parthenope”, napoli corresponding author: a. ascione <ascione@unina.it> riassunto: capalbo a. et al., valutazione del tasso di erosione in appennino meridionale da dati geologico-geomorfologici. (it issn 0349-3356, 2010). l’esumazione delle unità strutturalmente più profonde di una catena montuosa è determinata dalla rimozione di carico per fenomeni erosionali cui può associarsi tettonica estensionale. recenti dati strutturali e termocronometrici (aft) attribuiscono alla tettonica estensionale a basso angolo un ruolo importante nell’esumazione plio–pleistocenica delle unità profonde affioranti nei settori assiali dell’appennino meridionale. in questo lavoro è stata effettuata una stima del tasso di erosione nel lungo termine relativo ad un vasto settore che include anche le zone assiali dell’appennino meridionale, con lo scopo di giungere ad una valutazione del contributo dei processi erosionali e tettonici nell’esumazione delle unità tettoniche più profonde. il metodo utilizzato consiste nella valutazione dei volumi erosi a partire dai volumi dei corpi sedimentari risultanti da questa erosione. l’area di studio è rappresentata dal bacino wedge-top plio-pleistocenico di sant’arcangelo (basilicata) e dal relativo bacino di alimentazione. mediante un software g.i.s., è stato stimato il volume dell’unità deposta nel bacino durante un periodo in cui esso era isolato dalla contigua avanfossa bradanica, e valutata l’estensione del relativo paleobacino idrografico, la cui delimitazione è stata basata su evidenze di tipo geologico e morfotettonico. il valore del tasso di erosione medio, di 0,25 ± 0,07 mm/a, può essere considerato rappresentativo per la catena appenninica nel corso del quaternario e risulta di un ordine di grandezza inferiore all’esumazione plio-quaternaria di unità profonde desumibile dai dati aft. questo studio, pertanto, conferma l’importante componente tettonica nell’esumazione delle unità costituenti l’ossatura dell’orogene sudappenninico. abstract: capalbo a. et al., evaluation of the erosion rate in the southern apennines (italy) based on geological-geomorphological data. (it issn 0349-3356, 2010). the object of this study is the estimation of the long-term erosion rate in the southern portion of the apennines chain (southern italy). this was done with the aim of validating the hypothesis, proposed by mazzoli et al.. (2008), that thin-skinned extensional tectonics played a major role in the exhumation of formerly deeply buried tectonic units. more in detail, the study aimed at providing data on the erosional component of the rock exhumation which, based on apatite fission tracks data reported in mazzoli et al. (2008), has affected in the last 10 ma the deepest units in the southern apennines fold–and-thrust belt. the erosion rate was estimated based on the evaluation of the volume of deposits delivered by a large hydrographic basin to a continental environment sedimentary basin. the accumulation basin is the sant’arcangelo basin (hereinafter bsa), which developed as a marine environment wedge-top basin (originally connected to the apennines foreland basin) during the middle pliocene and evolved as an alluvial-lacustrine basin in the late part of the early pleistocene in response to the thrusting related uplift of a ridge located to the e of it (vezzani, 1966, 1967; carbone, 1991; pieri, 1994; zavala, 2000; patacca & scandone, 2001; giannandrea & loiacono, 2003; benvenuti et al., 2006). the drainage basin correlated to the bsa covers a large portion of the eastern slope of the southern apennines, and includes elevations formed of formerly deep-seated structural units (namely, lagonegro units and apulian platform unit) exhumed during pliocene-quaternary times. literature data and field surveys allowed the identification of the sedimentary unit (castronuovo-san lorenzo unit, csl, composed of lacustrine deposits passing laterally and upwards into alluvial plain sediments) which was deposited within the bsa when the basin was isolated from the neighboring foreland basin. the csl ranges in age from around 1 to 0,7 ma (patacca & scandone, 2001; mattei et al., 2004; sabato et al., 2005). g.i.s. elaborations allowed the reconstruction of the top and bottom surfaces and volume of the csl. the calculated volume value was corrected accounting for the erosion which affected the csl top surface, for the original width of the deposition area, for the suspended load loss, and for the sediment porosity. the paleo-hydrographic basin coeval to the csl was reconstructed based on geomorphological/geological evidences, which include the compositional analysis of pebbles of different units of the bsa succession. the obtained 0,25 ± 0,07 mm/a erosion rate value is comparable to the values, averaged over the last 0,7 ma and spanning from 0,2 to 0.3 mm/a, estimated for the eastern chain margin-foreland basin area in both the southern and northern apennines (amato et al., 2003; cyr & granger, 2008). these values, which can be considered as representative of erosion which has affected the apennines over the quaternary, are much lower than the pliocene-quaternary rock exhumation of formerly buried units estimated by aft data, and this points to the important contribution of the extensional tectonics in the exhumation processes in the southern apennines. parole chiave: : tasso di erosione, esumazione, morfotettonica, appennino meridionale. keywords: erosion rate, rock exhumation, tectonic geomorphology, southern apennines. il quaternario italian journal of quaternary sciences 23(1), 2010 75-90 introduzione i fenomeni erosivi che agiscono su una catena in via di strutturazione sono responsabili dello smantellamento di grandi volumi di materiale provocando, oltre alla risposta isostatica della crosta alla rimozione del carico (gilchrist et al., 1994), la venuta a giorno di corpi rocciosi originariamente sepolti a profondità anche di diversi km. tale fenomeno è noto come rock exhumation, termine che indica la variazione della profondità di 76 a. capalbo et al. una porzione di roccia rispetto alla superficie di separazione aria – roccia; ad essa, oltre ai processi erosionali, possono contribuire anche processi legati alla tettonica estensionale (england & molnar, 1990). questi ultimi sono stati descritti per la prima volta con la scoperta dei core complexs nella provincia del basin and range (ad es., moores et al., 1968), ma vi sono abbondanti evidenze dell’azione di faglie normali sull’esumazione di rocce medio crostali sia in regimi estensionali (ad es., foster & john, 1999) sia in quelli compressionali (mancktelow, 1985; selverstone, 1988, mazzoli et al., 2008). riguardo all’appennino meridionale, indicatori termici nelle unità tettoniche costituenti l’ossatura della catena documentano fenomeni di esumazione negli ultimi 10 ma (un periodo nel quale l’orogene si stava ancora strutturando) evidenziando, in qualche caso, la rapida esumazione di unità profonde negli ultimi 2–3 ma (mazzoli et al., 2008). in contesti morfoclimatici paragonabili all’appennino meridionale, ovvero con modesta energia del rilievo e clima temperato–umido, la sola azione dell’erosione non sembra poter giustificare tali fenomeni. infatti, sebbene in letteratura siano riportati valori dei tassi d’erosione anche molto elevati (superiori a 10 mm/a, adams et al., 2009), questi si riferiscono a piccoli bacini idrografici con forte rilievo locale (intorno a 3000 m) e a ridotte finestre temporali (poche decine di migliaia di anni), ovvero a contesti spazio-temporali più sensibili a fattori locali, quali la presenza di litotipi particolarmente erodibili e/o il verificarsi di fenomeni puntiformi (eventi franosi), il cui peso sul dato finale può essere molto forte. riguardo al contesto sudappenninico, una valutazione del tasso di erosione di lungo termine relativa al quaternario è stata effettuata per il settore includente il margine esterno della catena e parte della contigua avanfossa: dalla stima dei volumi erosi a partire da una paleotopografia ricostruita mediante l’uso di paleosuperfici, amato et al. (2003) hanno ottenuto valori dei tassi compresi tra 0,22 e 0,30 mm/a. questi valori limite si riferiscono rispettivamente agli ultimi 0,8 ma e 0,6 ma; tali intervalli riflettono l’incertezza legata all’età delle paleosuperfici marker. il confronto tra tali valori e la locale rapidità dei processi esumativi suggerisce che questi ultimi non possano essere imputati alla sola erosione, evidenziando il contributo della tettonica estensionale a basso angolo nell’esumazione plio–pleistocenica delle unità più profonde dell’orogene, come proposto da mazzoli et al. (2008). tuttavia, i valori del tasso d’erosione finora stimati potrebbero non essere del tutto significativi poiché derivanti da contesti geografici e geomorfologici non rappresentativi della catena nel suo insieme. essi, infatti, si riferiscono a settori caratterizzati da modesta energia del rilievo (paleosuperfici dissecate), mentre è possibile ammettere che le aree da cui provengono i tassi d’esumazione, caratterizzate da maggiore elevazione, rilievo locale e pendenze medie che, come noto, esercitano un forte controllo sull’erosione (ahnert, 1970; pienet & soriau, 1988; montgomery & brandon, 2002), siano state oggetto di dinamiche erosive più vivaci. d’altra parte, il tasso di erosione è influenzato dal grado di erodibilità dei litotipi e le successioni affioranti in catena, pur essendo molto eterogenee, sono presumibilmente meno erodibili di quelle clastiche dell’avanfossa e di quelle terrigene del margine esterno. questo studio ha come obiettivo la stima del tasso di erosione nel settore assiale dell’appennino meridionale. l’approccio utilizzato è di tipo indiretto, ovvero esso consiste nella valutazione dei volumi erosi a partire dalla stima dei volumi dei corpi sedimentari risultanti da questa erosione. l’area di studio è rappresentata dal bacino plio-pleistocenico di sant’arcangelo (nel seguito, bsa) e dal relativo bacino di alimentazione, che corrisponde ad un ampio settore della fascia assiale della catena in cui affiorano unità tettoniche che sono state oggetto di rapida esumazione mentre il bsa andava colmandosi. 1. inquadramento geologico la formazione dell’orogene sudappenninico, iniziata nel miocene, è proceduta attraverso l’accavallamento per thin–skinned thrusting dei domini più occidentali, o interni, su quelli più orientali (butler et al., 2004, e relativa bibliografia). nel settore di catena considerato in questo studio (fig. 1), le unità strutturali della pila orogenica rappresentate sono, dalla più alta: le unità liguridi e sicilidi, la piattaforma appenninica, le unità afferenti al bacino di lagonegro. discordanti su tali unità, si ritrovano depositi miocenici e plio–pleistocenici associati a wedge-top basins. l’ultima avanfossa plio–quaternaria della catena è occupata da sedimenti marini e colmata da depositi alluvionali del pleistocene medio (fig. 1). al di sotto delle coltri alloctone e dei depositi dell’avanfossa bradanica, si rinviene la piattaforma apula, che è stata coinvolta nelle fasi finali della compressione appenninica che vi ha generato faglie inverse e pieghe di grande lunghezza d’onda con uno stile deformativo da thick–skinned thrusting (shiner et al., 2004). l’unica porzione della piattaforma apula affiorante in catena (e nell’area di studio) è rappresentata dal m. alpi (mazzoli et al., 2006). dati termocronometrici (aft; mazzoli et al., 2008) indicano che l’esumazione di questa unità e delle unità lagonegresi costituenti l’alto del m. sirino (anch’esso ricadente nell’area di studio), originariamente sepolte a profondità di diversi km, si è in buona parte realizzata negli ultimi 2-3 ma. a partire dal tortoniano, la strutturazione della catena è accompagnata dall’apertura del bacino estensionale tirrenico (patacca et al., 1990; sartori, 1990) che porta, nel corso del quaternario, alla formazione di ampie e profonde depressioni peritirreniche (brancaccio et al., 1991; caiazzo et al., 2006). la cessazione dei raccorciamenti intorno a 0.7 ma è stata seguita dall’instaurarsi di una tettonica estensionale che ha modificato il precedente assetto strutturale (cello et al., 1982; cinque et al., 1993; hippolyte et al., 1994b). al contempo, i settori di avanfossa ed il margine esterno della catena sono stati oggetto di un uplift che ha portato ad un graduale aumento dell’elevazione media (cinque et al., 1993; amato & cinque, 2000). dal punto di vista geomorfologico, l’appennino meridionale è una catena asimmetrica che ha quote massime di poco superiori ai 2000 m e una quota media di circa 650 m (amato et al., 2003). le cime più elevate si ritrovano più vicine alla costa tirrenica, determinando un versante orientale più lungo e con un gradiente medio minore (cinque, 1992; ascione & cinque, 1999; amato et al., 2003). altra caratteristica della catena risiede nel fatto che, in generale, lo spartiacque principale non coincide con le cime più elevate ma si colloca ad e di esse (amato et al., 1995; salustri galli et al., 2000). tale situazione è stata determinata dalla riorganizzazione del reticolo fluviale conseguita alla formazione delle depressioni intramontane e, soprattutto, ai forti ribassamenti che interessavano le depressioni peritirreniche (amato et al., 1995; ascione & cinque, 1999; amato et al., 2003). 2.1 il bacino di sant’arcangelo: precedenti conoscenze il bsa (fig. 2) è stato oggetto di numerosi studi di carattere stratigrafico e strutturale. esso è stato interpretato da turco et al . (1990) come un bacino pull–apart e, da più autori (caldara et al., 1988; pieri et al., 1994; hippolyte et al., 1991, 1994a; patacca & scandone, 2001), come bacino piggyback. l’evoluzione del bacino, che all’atto della sua individuazione costituiva un’appendice dell’avanfossa appenninica, è stata fortemente condizionata dall’attività di thrust e-vergenti del cuneo di accrezione appenninico (patacca & scandone, 2001; benvenuti et al., 2006) o di thrust profondi (zuppetta et al., 2004). ai processi di raccorciamento viene anche imputato il sollevamento della dorsale di nocara (anche nota come dorsale di valsinni, o rotondella–colobraro, o stigliano–montegiordano) che separa il bsa dall’avanfossa bradanica, interpretato come effetto dell’attività di thrusts sul fronte alloctono esterno (pieri et al., 1994), o come prodotto del raccorciamento seguito alla deformazione profonda del 77valutazione del tasso di erosione ... substrato apulo (carbone et al., 1991; zuppetta et al., 2004; benvenuti et al., 2006). il riempimento del bacino è caratterizzato da una complessa architettura deposizionale e strutturale. in esso, vezzani (1967a; 1967b) individua due cicli trasgressivo-regressivi principali di età compresa tra il pliocene inferiore ed il calabriano. gli studi condotti dalla fine degli anni ’80 hanno portato ad un più dettagliato inquadramento delle diverse unità, senza tuttavia pervenire ad un’univoca definizione del quadro tettonostratigrafico: le diverse ricostruzioni si differenziano per il numero delle unità distinte, nonché per l’età e il significato, in termini di tettonica, attribuiti alle diverse unità (fig. 3). in sintesi, il bsa è occupato da sedimenti marini, transizionali e continentali organizzati in più sequenze deposizionali a carattere trasgressivo-regressivo; la base del riempimento è datata 3,3 ma (patacca & scandone, 2001). le successioni continentali sono dominanti nella zona occidentale e nella parte alta: a partire dalla deposizione dei conglomerati di castronuovo e degli eteropici depositi lacustri di s. lorenzo (caldara et al., 1988; pieri et al., 1994; patacca & scandone, 2001), ovvero del gruppo di profico (zavala, 2000) o sintema di missanello – noepoli (benvenuti et al., 2006), la sedimentazione all’interno del bsa si sviluppa in ambiente esclusivamente continentale. la sedimentazione termina con la deposizione, in ambiente di conoidi alluvionali principalmente progradanti dai quadranti occidentali e, subordinatamente, da quelli meridionale e settentrionale, di quelli noti in letteratura come conglomerati di serra corneta, di età pleistocene medio (vezzani, 1967a; 1967b; carbone et al., 1991; pieri et al., 1994; zavala, 2000; patacca & scandone, 2001; giannandrea fig. 1 carta geologica schematica dell’appennino meridionale. da mazzoli et al., 2008, modificata. geological sketch map of the southern apennines. mazzoli et al., 2008 modified. fig. 2 schema geologico del bacino di sant’ arcangelo (da patacca & scandone, 2001, modificata). 1) depositi alluvionali e subordinatamente di spiaggia (olocene); 2) depositi terrazzati continentali e subordinatamente di mare basso (pleistocene medio e superiore); 3) depositi alluvionali e fluviodeltaici (conglomerato di serra corneta nel bsa, pleistocene medio); 4) depositi al luvionali nel bsa (conglomerato di castronuovo, pleistocene medio); 5) depositi lacustri (argille di san lorenzo, pleistocene medio); 6) depositi di fandelta e conoidi alluvionali prossimali (sintema del sinni, pleistocene inferiore e medio); 7) depositi pelitici di prodelta e subordinati depositi lagunari nel bsa (parte superiore del sintema del sarmento, pleistocene inferiore); sabbie di mare basso (sabbie di montalbano, pleistocene inferiore) e depositi pelitici di piattaforma aperta (argille di gravina, pleistocene medio; argil le sub-appennine, pleistocene inferiore e medio) nella fossa bradanica; 8) depositi di fandelta e piattaforma (parte inferiore del sintema del sarmento nel bsa; sabbie di tursi lungo il margine esterno della dorsale di nocara, pleistocene inferiore); 9) sabbie di mare basso (sabbie di sant’arcangelo, pleistocene inferiore); 10) depositi pelitici di piattaforma (argille di craco, pleistocene inferiore); 11) sequenza deposizionale p1-2: conglomerati e arenarie di fronte di fandelta e di mare basso, depositi pelitici da lagunari a marini di piattaforma aperta con subordinate argille diatomitiche, conglomerati e arenarie di fronte di fandelta passanti lateralmente (margine esterno dell’appennino) ad arenarie bioclastiche e calcareniti silicoclastiche (pliocene superiore); 12) coltri appenniniche e depositi discordanti più antichi di 3.7 ma; 13) fronte sepolto delle coltri appenniniche; 14) faglie inverse e sovrascorrimenti plio-pleistocenici; 15) faglie normali; 16) faglie trascorrenti; 17) asse di anticlinale; 18) asse di sinclinale; 19) contatti tettonici. geological sketch showing the plio-pleistocene deposits and the major tectonic features in the bsa and in the southern part of the bradano trough (modified after patacca & scandone, 2001): 1) alluvial and subordinate shore deposits (holocene); 2) terraced continental and shallow-marine deposits (upper-middle pleistocene); 3) alluvial and prograding fluvio-deltaic deposits (serra corneta conglomerate in the bsa, middle pleistocene); 4) alluvial deposits in the bsa (castronuovo conglomerate, middle pleistocene); 5) lacustrine deposits (san lorenzo clay, middle pleistocene); 6) fan-delta deposits, including proximal alluvial fans (sinni synthem, middle-lower pleistocene); 7) prodelta mudstones and subordinate brackish-water lagoonal deposits in the bsa (upper portion of the sarmento synthem, lower pleistocene); nearshore sandstones (montalbano sandstone, middle pleistocene) and open-shelf muddy deposits (gravina clays, middle pleistocene; sub-apenninic clay, middle-lower pleistocene) in the bradano trough; 8) fan-delta to shelf deposits (lower portion of the sarmento synthem in the bsa; tursi sandstone along the eastern margin of the nocara ridge, lower pleistocene); 9) shallow-marine sandstones (sant’arcangelo sandstones, lower pleistocene); 10) shelf mudstones (craco clay, lower pleistocene); 11) p1-2 depositional sequence: fan-delta-front to shallow-marine conglomerates and sandstones, lagoon to openshelf mudstones including subordinate diatomitic clays, fan-delta-front conglomerates and sandstones laterally grading (outer margin of the apennines) into bioclastic sandstones and siliciclastic calcarenites (upper pliocene); 12) apenninic nappes and thrust sheet-top deposits older than 3.7 ma; 13) buried front of the apennine nappes; 14) plio-pleistocene thrusts; 15) normal faults; 16) strike-slip faults; 17) anticline axis; 18) syncline axis; 19) tectonic contacts. 78 a. capalbo et al. 79 & loiacono, 2003; benvenuti et al., 2006). tale evento è seguito da un sollevamento generalizzato che investe anche la contigua avanfossa bradanica (cinque et all., 1993) e porta le superfici eroso–deposizionali impostate sui conglomerati di serra corneta a quote che vanno da circa 1000–1100 m presso il margine occidentale del bacino a circa 700 – 800 m nella sua porzione centrale. l’uplift è stato accompagnato e seguito da dissezione, interrotta da brevi fasi di stazionamento dei livelli di base e aggradazione fluviale che hanno lasciato traccia in diversi ordini di terrazzi lungo le principali valli che attualmente dissecano il bacino. l’architettura del bacino è stata fortemente condizionata dall’individuazione della dorsale di nocara. tale struttura ha costituito un alto sommerso nelle fasi iniziali della sua formazione, rispettivamente ascritte al pliocene (vezzani, 1967a; 1967b; carbone et al., 1991; pieri et al., 1994) o al periodo che va dalla parte alta del pleistocene inferiore alla parte bassa del medio (zavala, 2000; patacca & scandone, 2001). sulla base di correlazioni stratigrafiche tra i depositi affioranti nel bsa e nella contigua porzione di avanfossa, più autori (carbone et al., 1991; zavala, 2000; patacca & scandone, 2001; giannandrea & loiacono, 2003; benvenuti et al., 2006; fig. 4) mettono in relazione il progredire del sollevamento della dorsale con l’isolamento del bacino dall’avanfossa bradanica. la dorsale avrebbe, infatti, costituito un ostacolo in grado di inibire il trasporto dei sedimenti più grossolani verso l’avanfossa, dove al contempo si registrava la deposizione di una successione pelitica monotona (zavala, 2000; patacca & scandone, 2001). argomenti più dibattuti sono l’età dell’emersione della dorsale e la risposta sedimentaria registrata dal bacino a seguito di tale evento. alcuni autori (zavala, 2000; giannandrea & loiacono, 2003; benvenuti et al., 2006) hanno interpretato, come effetto delle fasi finali del sollevamento, la deposizione di unità lacustri–alluvionali affioranti nei settori centro-settentrionale e centro-meridionale del bsa, rispettivamente rappresentate dai depositi lacustri di san lorenzo e dal sintema di francavilla (giannandrea & loiacono, 2003). 3. stima dei parametri utili al calcolo del tasso di erosione medio la valutazione dei tassi di erosione di breve o lungo termine può essere ottenuta, direttamente o indirettamente, mediante metodologie basate su misurazioni dei nuclidi cosmogenici prodotti in situ (ad es. granger et al., 1996). in alternativa, i tassi di erosione di lungo termine possono essere stimati a partire dalla valutazione dei volumi erosi da una data area (ad es., amato et al., 2003), oppure dalla valutazione dei volumi accumulati in un dato bacino e attribuibili ad un ben fig. 3 schema di sintesi delle ricostruzioni stratigrafiche del bsa. in grigio è mostrata l’unità che include i sedimenti lacustri del bacino di s. lorenzo. la freccia nera indica l’inizio dell’emersione della dorsale di nocara nelle interpretazioni dei diversi autori. synthetic sketch showing the different interpretations of the bsa stratigraphy. in grey is shown the unit which, according to the different authors, includes the s. lorenzo lacustrine deposits. the black arrow indicates the onset of the nocara ridge emersion. valutazione del tasso di erosione ... 80 preciso bacino di alimentazione (ad es., kuhlemann et al., 2002). nel primo caso, è necessaria la ricostruzione di una paleotopografia a partire, ad esempio, dalla presenza di “paleosuperfici” erosionali o di superfici deposizionali di età nota. tuttavia, questa operazione risulta più agevole in avanfossa o in quei settori dove tali forme sono assimilabili a superfici planari. più ardua è la ricostruzione di una paleotopografia di riferimento nei settori della catena emersi in tempi più antichi (miopliocene), che sono stati oggetto di prolungato modellamento e disarticolati dalla tettonica quaternaria. la valutazione dei volumi di materiali accumulati può essere effettuata in quelle aree che hanno rappresentato il recapito dei sedimenti erosi all’interno di un dato paleobacino di alimentazione e in cui la perdita di sedimento risulta trascurabile o quantomeno valutabile. in questo lavoro viene applicata la seconda delle metodologie sopra descritte all’area del bsa e al suo bacino di alimentazione, nel quale ricadono il m.te sirino e il m.te alpi, due delle aree da cui provengono le stime sui tassi di rock exhumation. il calcolo del tasso di erosione secondo il metodo adottato richiede di ottenere una stima dei parametri da immettere nella [1], vs( ––– )sa[1] temedio = –––––– ∆t dove temedio rappresenta il tasso d’erosione medio (mm/a), vs (mm3) il volume dei depositi sedimentati all’interno del bacino durante l’intervallo di tempo ∆t (a) ed sa (mm2) la superficie del bacino idrografico da cui avrebbero tratto alimentazione gli stessi depositi. la determinazione dei parametri vs e ∆t richiede l’individuazione di un corpo sedimentario, ben vincolato cronologicamente. la revisione critica dei dati bibliografici e lo studio di terreno hanno permesso di identificare, tra le unità che occupano il bsa, quella più idonea per gli scopi del lavoro (vedi par. 3.1) e di pervenire ad una attendibile delimitazione del corrispettivo paleobacino alimentatore (vedi par. 3.2). riguardo alla stima del parametro vs, che ha richiesto la delimitazione in 3d del corpo sedimentario di interesse, ovvero la ricostruzione delle superfici di tetto e di letto di questo, ci si è avvalsi della cartografia geologica esistente, rappresentata dai fogli 211 s. arcangelo e 200 tricarico della carta geologica d’italia in scala 1:100.000, dal foglio 506 s. arcangelo in scala 1:50.000 (http://www.apat.gov.it/ media/carg/stampati/506/foglio.htm), dalle carte in scala 1:50.000 di carbone et al. (1991) e di benvenuti et al.. (2006), nonché dalla cartografia riportata in vezzani (1967a), patacca & scandone (2001), e giannandrea & loiacono (2003). dal punto di vista operativo, il trattamento dei dati è stato eseguito con l’utilizzo di un software g.i.s. (arcview 9.1 e.s.r.i.), con il quale è stato anche realizzato un d.e.m. dell’area di interesse a partire dalla digitalizzazione delle curve di livello della topografia in scala 1:25.000. fig. 4 schema evolutivo del bsa tra il pliocene superiore e il pleistocene inferiore (da zavala, 2000, modificato). sketch of the late pliocene early pleistocene evolution of the bsa (zavala, 2000 modified). a. capalbo et al. 3.1 identificazione ed inquadramento cronologico del corpo sedimentario di interesse la condizione ideale per l’applicazione del metodo sopra descritto è rappresentata da corpi deposti in bacini a drenaggio endoreico. in questo caso di studio, ciò si è tradotto nell’identificazione delle unità sedimentatesi nel bsa durante la fase in cui questo è stato “isolato” dall’avanfossa a seguito dell’emersione della dorsale di nocara. la rilettura critica dei dati suggerisce che la separazione del bsa dall’avanfossa può essere messa in relazione con il radicale mutamento nei rapporti laterali di sedimentazione tra bsa e l’avanfossa, occorso tra la parte alta del pleistocene inferiore e la parte bassa del pleistocene medio. durante questo intervallo, in avanfossa si registra una brusca interruzione del flood–dominated system e la sedimentazione di una successione argillosa monotona (rispettivamente, gruppo di montalbano jonico di zavala, 2000 e parte alta delle sub–apenninic clay di patacca & scandone, 2001), eventi collegati all’individuazione di un alto morfostrutturale (dorsale di nocara) in grado di inibire il trasporto del sedimento più grossolano verso est. l’emersione della dorsale può anche giustificare il mutamento, nel tardo pleistocene inferiore, delle condizioni ambientali nel bsa, dove si instaurano condizioni di generalizzata continentalità connotata da ambienti lacustri ed eteropici ambienti alluvionali; ambienti marino-transizionali persistono solo nella zona ne del bacino (pieri et al., 1994) (fig. 5). le successioni alluvionalilacustri relative a questa fase (inquadrabile tra la parte alta del pleistocene inferiore e la parte bassa del pleistocene medio) sono ascritte, relativamente al settore settentrionale del bsa, al gruppo di profico (zavala, 2000) e, per il settore s, al sintema di francavilla (giannandrea & loiacono, 2003); da benvenuti et al. (2006), esse sono inquadrate nella parte alta del sintema di missanello – noepoli (sub-sintemi mn3 e mn4). nel quadrante ne del bsa, gli ambienti continentali sarebbero stati limitati dall’anticlinale, ad orientazione meridiana, di guardia perticara – alianello, ad ovest della quale si individuava un bacino a sedimentazione lacustre (ciclo di san lorenzo) con apporti dai quadranti n e nw, e fluviale (pieri et al.,1994; caggianelli et al., 1992). la persistenza di un ambiente marino ad oriente dell’anticlinale è testimoniata, secondo pieri et al. (1994), da depositi in facies di fan delta con apporti da nw (ciclo del sauro). riguardo all’età dei depositi marini, marino (1994) individua nell’area di serra petrizza (* in fig. 5) la comparsa di gephyrocapsa sp.3, che marca la zona a p. lacunosa (rio et al., 1990) posta a circa 0,94 ma (castradori, 1993). riguardo all’unità di san lorenzo, questa si compone di un conglomerato di conoide alluvionale basale passante ad una successione pelitica lacustre con intercalazioni di livelli vulcanoclastici e spessore di circa 200 m, e di un deposito conglomeratico – sabbioso sommitale (caggianelli et al., 1992). la successione lacustre costituisce un corpo ad assetto sinclinalico, la cui formazione è attribuita da caggianelli et al. (1992) a tettonica sinsedimentaria sulla base della presenza di strati di crescita e ripetuti slumps intraformazionali. da misure paleomagnetiche, la base ed il tetto della successione, entrambi con polarità normale, vengono rispettivamente riferiti al sub-chron jaramillo e al chron brunhes (mattei et al., 2004; sabato et al., 2005); la porzione centrale, che include un livello vulcanoclastico datato 1,1±0,3 ma (misure k/ar; caggianelli et al., 1992) e caratterizzata da polarità inversa, viene riferita al chron matuyama (sabato et al., 2005). tale inquadramento contrasta con l’attribuzione di un’età compresa tra 0,70 e 0,66 ma all’unità costituita dal lacustre di san lorenzo e dagli eteropici conglomerati di castronuovo, proposta da patacca & scandone (2001) sulla base della correlazione delle superfici di discontinuità interposte alle unità affioranti nel bsa con quelle che separano le unità dell’avanfossa ad e della dorsale di nocara. in particolare, tale attribuzione si basa sulla correlazione di depositi grossolani in facies di fan delta (sintema del sinni, stratigraficamente sottoposto all’unità san lorenzo-conglomerati di castronuovo) che sono ritenuti marcare l’isolamento del bsa dall’avanfossa, con la parte superiore delle sub–apenninic clay. al sintema del sinni viene, tuttavia, attribuita un’età (0,92 0,70 ma) che ricopre in parte quella ottenuta per i depositi lacustri con dati più recenti (cf. mattei et al., 2004; sabato et al., 2005). la ripresa, a partire da 0,70 ma, della sedimentazione sabbiosa in avanfossa (montalbano sandstone) e la coeva deposizione nel bsa dei conglomerati di serra corneta, marcano il superamento della soglia di nocara (patacca & scandone, 2001). i dati fin qui esposti permettono di ipotizzare che l’unità depostasi all’interno del bsa in condizioni di isolamento sia quella che include la successione lacustre del ciclo di san lorenzo (fig. 3). dal punto di visto giaciturale, i depositi dell’unità castronuovo–san lorenzo (a seguire, csl) si presentano sub-orizzontali nella parte centrale del bsa, mentre nei settori occidentali risultano leggermente deformati. frequentemente, al tetto dell’unità si rinviene uno spesso paleosuolo di colore rosso che, secondo patacca & scandone (2001), marca un periodo di inattività tettonica. 3.2 stima del parametro ∆t i vincoli derivanti dall’integrazione dei dati paleomagnetici, geocronologici e stratigrafici esistenti, permettono di definire con affidabile precisione l’intervallo cronostratigrafico corrispondente all’unità csl (ovvero, il ∆t). tali vincoli permettono di attribuire alla base dei depositi lacustri un’età compresa tra 1,07 ma e 0,99 ma, desumibile dalla correlazione paleomagnetica con il sub–chrone jaramillo (mattei et al., 2004; sabato et al., 2005). per quanto riguarda il limite superiore, i dati collocano il top dei depositi pelitici del lacustre di san lorenzo nel chrone brunhes, permettendo di assegnare ad esso un’età non più antica di 0,78 ma (sabato et al., 2005); al contempo, considerando che la successione lacustre si chiude con un conglomerato di spessore pari a circa 50 m (caggianelli et al., 1992), l’età del tetto dell’unità risulta < 0,78 ma. per l’inquadramento del tetto, informazioni utili derivano dalla correlazione delle discontinuità tra i corpi sedimentari del bsa con quelle, identificate da patacca & scandone (2001) e cronostratigraficamente meglio vincolate, che separano le unità del settore di avanfossa ad oriente della dorsale di nocara: in particolare, è ipotizzabile che la discontinuità datata 0.70 ma ed assegnata al top del sintema del sinni da patacca & scandone (2001) corrisponda al tetto dell’unità csl. sulla base di tali considerazioni è possibile circoscrivere la finestra temporale di interesse tra 1,03±0,04 81valutazione del tasso di erosione ... ma e 0,70 ma, da cui è possibile ottenere valori di ∆t minimo e massimo rispettivamente pari a 290 ka [0,99 ma – 0,70 ma] e 370 ka [1,07 ma – 0,70 ma] (tab. 1). 3.3 stima del parametro vs dai dati esposti nei paragrafi precedenti risulta che, a partire dalla parte alta del pleistocene inferiore, si registra la graduale fuoriuscita del mare dal bsa: tra il pleistocene inferiore e il pleistocene medio, ambienti a sedimentazione marina (fan delta del ciclo del sauro; pieri et al., 1994) permangono solo nel settore settentrionale del bacino, ad e dell’anticlinale di guardia perticara–alianello (fig. 5). più a sud, la sedimentazione del csl interessa una superficie meno estesa, verso w, 82 fig. 5 shaded relief dell’area di studio con le perimetrazioni dei paleobacini di sedimentazione ed idrografico relativi all’unità csl. 1) spartiacque attuale; 2) spartiacque del paleobacino idrografico con minima estensione, dove non coincidente con l’attuale; 3) spartiacque del paleobacino idrografico con massima estensione, dove non coincidente con l’attuale; 4) spartiacque del paleobacino idrografico, dove non coincidente con l’attuale; 5) paleobacino di sedimentazione; 6) sito di campionamento della sezione di serra petrizza. shaded relief of the study area showing the boundary of the csl sedimentary basin and the paleo-divide of the correlative hydrographic basin. 1) present divide; 2) divide of the paleohydrographic basin with minimum width (mapped where non-coincident with the present divide); 3) divide of the paleohydrographic basin with maximum width (mapped where non-coincident with the present one); 4) divide of the paleohydrographic basin, where non-coincident with the present divide; 5) csl sedimentary basin; 6) serra petrizza section site. a. capalbo et al. di quella corrispondente all’attuale areale di affioramento delle unità plio-pleistoceniche del bsa, in quanto il sollevamento dell’alto strutturale ha coinvolto, deformandole, anche le unità sottostanti il csl (giannandrea & loiacono, 2003; benvenuti et al., 2006). tenuto conto di ciò, l’ampiezza della superficie d’accumulo del csl (fig. 5) risulta pari a circa 690 km2. la stima del volume del csl è stata effettuata a partire dalla ricostruzione delle superfici di letto e di tetto dell’unità, corrispondenti rispettivamente al contatto con il sottostante sintema del sinni di patacca & scandone (2001) e con i sovrastanti conglomerati di serra corneta. la prima fase dell’elaborazione ha prodotto la rappresentazione cartografica dell’unità di interesse attraverso la modifica della carta geologica d’italia in scala 1:100.000, sulla base della mappatura dell’area presentata in patacca & scandone (2001), delle considerazioni fin qui esposte e delle osservazioni effettuate sul campo. successivamente, con l’ausilio del g.i.s., la carta ottenuta è stata georeferenziata e sono stati realizzati due shape file a geometria di punti relativi ai limiti di tetto e letto del csl. a tali punti è stata associata la quota assoluta attraverso la sovrapposizione con il d.e.m. infine, utilizzando la funzione spline tension del g.i.s., tutti i punti ottenuti sono stati interpolati da una superficie che meglio ne approssima la distribuzione. le irregolarità derivanti dalla discontinua distribuzione dei punti sono state omogeneizzate attraverso la funzione neighborhood statistics, ottenendo due superfici con una risoluzione di 500 m (fig. 6a e 6b). la differenza pixel a pixel tra la quota della superficie di tetto e quella di letto ha fornito lo spessore dell’unità in ciascun pixel, con un valore medio di circa 140 m (fig. 6c). applicando la [2], n [2] vtot = σ si * ap i = 1 dove vtot rappresenta il volume dell’unità di interesse, 83 tab. 1 sintesi dei parametri vs, ss e ∆t calcolati e stima del tasso di erosione medio. synthesis of the calculated vs, ss e ∆t and estimation of the average erosion rate. fig. 6 elaborazioni g.i.s. delle superfici di tetto (a) e di letto (b) e spessore (c) dell’unità csl. la risoluzione è di 500 m per pixel. g.i.s. elaborations of the csl top (a) and bottom (b) surfaces and thickness (c). resolution: 500 m per pixel. valutazione del tasso di erosione ... si lo spessore dell’unità nel pixel i-mo e ap l’area di ciascun pixel (in questo caso pari a 500m * 500m = 2,5 * 105 m2), si è stimato un volume dell’unità csl pari a 98,583 km3. tale valore non corrisponde del tutto al volume eroso nell’ambito del bacino idrografico drenante verso il bsa al tempo della deposizione dell’unità csl, in quanto esso non contempla le perdite di carico in sospensione, né le eventuali articolazioni minori, per dissezione, del tetto del csl. all’interno del bacino si hanno, infatti, evidenze di erosione di tale unità occorsa prima della deposizione dei conglomerati di serra corneta. tuttavia, lo spesso paleosuolo che frequentemente marca il contatto tra le due unità testimonia la diffusa presenza di superfici sostanzialmente stabili impostate sull’unità csl; pertanto, la sottostima derivante dalla locale erosione dei depositi è stata corretta apportando un +15% rispetto al volume calcolato. la sottostima derivante dalle fuoriuscite di carico in sospensione è stata corretta aggiungendo, al volume inizialmente calcolato, un ulteriore 20% stimato ammettendo che, del carico in sospensione complessivo (ragionevolmente, il 40% del carico totale), una buona parte sia stata trattenuta nelle aree a sedimentazione lacustre. un altro problema è rappresentato dall’incertezza relativa all’estensione, in senso e-w, del bacino di sedimentazione del csl, legata alla difficoltà di valutare lo spessore del pacco sedimentario deformato che mantellava l’ossatura pre-quaternaria della dorsale di nocara. la superficie fin qui considerata (fig. 5) corrisponde alla minima estensione in senso e-w; nell’ipotesi che il bacino si estendesse fino all’attuale affioramento dei depositi pliocenici (unità di caliandro) presenti sulla dorsale, è stata valutata anche la massima possibile ampiezza del bacino, che è risultata maggiore del 15% di quella rappresentata in fig. 5. infine, va osservato che il vs rappresenta una sovrastima del volume effettivamente eroso nel bacino idrografico: i depositi, infatti, sono dotati di una porosità superiore a quella delle rocce da cui essi sono derivati. tenendo conto dei valori di porosità delle diverse tipologie di depositi clastici di ambiente continentale (meinzer, 1923; davis, 1969; cohen, 1965; maccary & lambert, 1962), della composizione dei depositi del csl e della composizione delle rocce da cui questi derivano, il valore del vs effettivo è stato stimato apportando una riduzione del 10% rispetto al volume calcolato. apportando le correzioni relative alle perdite di carico, all’erosione e all’estensione del bacino di sedimentazione e alla porosità, si ottengono stime del vs di 122,440 km3 e di 140,806 km3 relative, rispettivamente, al minimo e al massimo volume di sedimenti riferibili all’unità cls (tab. 1). 3.4. identificazione del paleobacino idrografico: stima del parametro sa la fig. 5 mostra l’andamento dello spartiacque dei bacini che drenano verso il bsa. a s, esso attraversa la dorsale del pollino; da qui prosegue verso w e n seguendo lo spartiacque appenninico attraverso il m. sirino e tra i bacini intramontani del vallo di diano e dell’alta val d’agri; a ne, si chiude includendo il bacino della f.ra di gorgoglione. con l’obiettivo di valutare se e in quale misura il paleospartiacque del bsa coevo alla deposizione del csl si discosti da quello attuale, è stata ricostruita la distribuzione degli alti/bassi morfologici circostanti il bacino e, quindi, delle possibili direzioni dei drenaggi nel tardo pleistocene inferiore. oltre che dall’analisi della topografia e dal riesame di dati a carattere morfotettonico e morfostratigrafico relativi alle aree circostanti il bsa, informazioni utili a ricostruire le direttrici principali del paleodrenaggio sono state ottenute dalla composizione dei clasti nelle diverse unità conglomeratiche che occupano il bacino. i risultati hanno mostrato una netta dominanza, nei depositi pliocenici del bsa, di clasti derivati dalle unità poste in posizione strutturale (unità liguridi e formazione di albidona) e stratigrafica (flysch di gorgoglione) più elevata nell’edificio orogenico. queste costituiscono la quasi totalità del materiale nei depositi conglomeratici basali del ciclo di caliandro (p1-2 in fig. 2) affioranti nel settore se del bacino (presso la diga di m. cotugno). depositi coevi affioranti nel settore nw (nei pressi della confluenza agri–nocito) presentano anche detrito proveniente dalle unità lagonegresi, per la loro ubicazione riconducibili all’areale corrispondente a quella degli attuali rilievi m. enoc – m. volturino. la venuta a giorno di unità più profonde è testimoniata dal graduale aumento, nei depositi del pleistocene inferiore dell’intero bacino (sinni synthem di patacca & scandone, 2001; aliano synthem di benvenuti et al., 2006) della componente carbonatica, nonché dalla comparsa di apporti provenienti dalle unità lagonegresi (formazioni dei calcari con selce e scisti silicei) anche nei depositi dell’area meridionale (episcopia). questi ultimi, in particolare, sono riconducibili all’area corrispondente all’attuale rilievo del m. sirino. a testimoniare che tale rilievo si fosse già individuato, nel pleistocene inferiore, non solo come alto morfostrutturale ma anche come spartiacque, è la presenza di detrito proveniente da unità lagonegresi in depositi conglomeratici del pleistocene inferiore localizzati sul versante tirrenico del sirino (depositi del bacino lacustre della media valle del f. noce, la rocca & santangelo, 1991; depositi dei terrazzi marini nella bassa valle del f. noce; filocamo, 2007). il detrito carbonatico rinvenuto nei depositi del settore meridionale del bacino (riconducibile alla dorsale del pollino) suggerisce che, verso s, la posizione dello spartiacque non sia sostanzialmente cambiata. nel pleistocene inferiore, infatti, il pollino costituiva un alto morfologico anche rispetto all’area a sw di esso, che accoglieva la sedimentazione di unità marine e, dal pleistocene medio, conoidi alluvionali (russo & schiattarella, 1992 e relativa bibliografia). riguardo alla componente carbonatica del detrito delle unità del bsa, va segnalata la presenza nei conglomerati di castronuovo affioranti nella zona meridionale del bacino, di clasti di dolomia triassica e calcari eocenici riconducibili all’unità lungro – verbicaro sensu iannace et al. (2008). la presenza, in particolare, di tali clasti nella zona di preti, non imputabile a cannibalismo interno al bacino (il csl, in quest’area, ricopre le unità più antiche, che affiorano solo più ad e), suggerisce che l’andamento del paleospartiacque nel settore sw era diverso dall’attuale. l’area sorgente di tale detrito si situa, infatti, a w dell’attuale spartiacque (che separa i bacini del f. sinni e del mercure-lao), la cui individuazione risale al pleistocene medio. essa può essere, infatti, correlata ai ribassamenti responsabili 84 a. capalbo et al. della formazione del bacino lacustre del mercure, i cui alti bordieri recano indizi di paleodrenaggi diretti verso il f. sinni (schiattarella et al., 1994; cavinato et al., 2001). per queste evidenze e per i dati derivanti dal contiguo settore costiero tirrenico, il paleospartiacque è stato tracciato sugli alti che bordano il bacino del mercure verso sw (fig. 5). indizio del fatto che il versante occidentale di tali alti fosse già dissecato da corsi a recapito tirrenico è la presenza, in questo tratto della costa, di terrazzi marini risalenti alla parte bassa del pleistocene inferiore (filocamo et al., 2009). l’andamento del paleospartiacque nel settore a n-ne del m. sirino è stato ricostruito sulla base dei rapporti cronologici tra il bsa ed i bacini lacustri pleistocenici che occupavano le depressioni intramontane dell’alta val d’agri, dei fiumi pergola-melandro e del vallo di diano. la formazione dell’alta val d’agri postdata il colmamento del bsa (è legata ad una faglia che corre lungo i l margine ne del bacino e sospende i conglomerati di serra corneta e superfici erosionali a questi correlabili; di niro et al., 1992) ed è, pertanto, inquadrabile nel pleistocene medio. sebbene l’attuale idrografia sia condizionata dalla presenza del bacino, gli apporti dalle unità lagonegresi (derivanti dall’area enocvolturino) ai depositi del ciclo di caliandro indicano che il drenaggio, almeno nel settore orientale dell’area includente l’attuale alta val d’agri aveva recapito nel bsa fino dal pliocene. una notevole incertezza (fig. 5) riguarda l’andamento del paleospartiacque a n dei rilievi impostati sulle unità lagonegresi, a causa della mancanza di vincoli utili a discriminare se il paleodrenaggio in quest’area fosse orientato verso il bsa o verso il bacino del pergola-melandro. quest’ultimo è occupato da depositi fluviali e lacustri del pleistocene inferiore, deformati e quindi tagliati da terrazzi fluviali ascritti al pleistocene medio e riferiti ad un drenaggio verso n (santangelo, 1991). ciò porta a ritenere poco probabile che il bacino idrografico coevo del csl (cf. fig. 5) si estendesse più a n delle aree di affioramento dei depositi deformati e terrazzati presenti nell’alto bacino del pergola-melandro. improbabile è anche l’ipotesi che il paleospartiacque si spingesse ad ovest della dorsale dei m.ti della maddalena, che separa l’alta val d’agri dal vallo di diano. infatti, l’individuazione di quest’ultimo (che è occupato da una potente successione lacustre pleistocenico-olocenica in massima parte sepolta), ascritta al pleistocene inferiore (ascione et al., 1992; karner et al., 1999), risulta presumibilmente anteriore o, comunque, non successiva alla deposizione dell’unità csl. difficile da definire è la posizione del paleospartiacque al l imite meridionale del bacino del t. camastra, che disseca i depositi del bacino wedge-top plio-pleistocenico di calvello. tuttavia, pur in mancanza di precisi vincoli o evidenze geomorfologiche (l’area è interamente occupata da terreni di substrato molto erodibili), è possibile ipotizzare, per il paleospartiacque coevo del csl, una posizione non molto dissimile dall’attuale. a seguire il colmamento, con facies continentali, nella parte bassa del pleistocene inferiore, l’area di calvello viene interessata da sollevamento e dissezione (amore et al., 1996; amato & cinque, 1992) ed è, pertanto, possibile ammettere che i bacini drenanti verso quell’area abbiano rapidamente guadagnato, per erosione regressiva, un’estensione simile a quella attuale. riguardo al settore ne del paleobacino, i dati discussi al par. 4.1 indicano che il drenaggio dell’area attualmente occupata dal bacino della f.ra di gorgoglione aveva un recapito esterno al bsa (area di serra petrizza): da quest’area, infatti, provenivano gli apporti ai depositi marino – transizionali del ciclo del sauro sensu pieri et al. (1994). la possibile delimitazione del paleobacino idrografico del bsa coevo al csl è rappresentata in fig. 5. con l’intento di considerare, nella valutazione della sa, l’incertezza associata alla posizione del paleospartiacque, sono state effettuate stime degli areali sottesi rispettivamente dalle lunghezze minima e massima di questo. tuttavia, il valore della sa dipende dal rilievo locale associato al paleobacino. l’attuale bacino è connotato da un pronunciato rilievo, in parte acquisito con la dissezione che ha accompagnato il sollevamento post-orogeno, iniziato dopo la deposizione dei conglomerati di serra corneta. la paleotopografia coeva del csl è alquanto difficile da ricostruire: possibili superfici di riferimento (ad es., lembi di superfici erosionali riferibili ad antichi livelli di base locali) sono molto rare, discontinue e di incerta collocazione cronologica. ancora più incerta sarebbe la ricostruzione del paleo-rilievo relativo a tali superfici, che, come indica la composizione del detrito costituente i depositi del bsa, era già impostato su successioni a diverso grado di erodibilità. tuttavia, la presenza di alti impostati su successioni resistenti (soggetti a trascurabile abbassamento delle cime), consente di assumere che il rilievo sia andato aumentando con il procedere della dissezione; al contempo, si può ritenere che anche dove l’abbassamento delle cime è più rapido (ovvero, dove affiorano successioni più erodibili) il rilievo non sia diminuito con l’ultima forte ondata di dissezione. pertanto, il rilievo attuale può essere considerato come il valore limite superiore per la superficie del paleobacino; il limite inferiore (puramente teorico) è rappresentato da una superficie con assenza di rilievo: nei due casi limite, la variazione nell’ampiezza della superficie risulta del 6% circa (tab. 1). i valori della sa ottenuti considerando la minima e massima perimetrazione del paleobacino idrografico risultano pari a 1466,901 km2 e 1551,713 km2 (superficie piatta) e a 1731,179 km2 e 1830,459 km2 (superficie con rilievo attuale) (tab. 1; fig. 5). 4. discussione i parametri necessari all’applicazione della [1] sono stati combinati tra loro in modo da pervenire ad una stima del tasso di erosione che tenga conto dell’incertezza associata alla valutazione di ciascuno di essi (tab. 1). con la [1] si sono ottenuti, per il tasso d’erosione, un valore minimo compreso tra 0,18 e 0,19 mm/a e un valore massimo compreso tra 0,31 e 0,33 mm/a che, rispettivamente, rappresentano le medie relative ai due intervalli di tempo di 370 ka e 290 ka. dalla combinazione dei diversi valori, si ottiene un valore medio del tasso di 0,25 ± 0,07 mm/a. i valori del tasso di erosione ottenuti sono confrontabili con stime, comprese tra 0,2 e 0,3 mm/a, del tasso di erosione medio negli ultimi 0,6-0,8 ma valutato dai volumi “mancanti” nel settore avanfossa-catena 85valutazione del tasso di erosione ... esterna (amato et al., 2003), nonché con quelle ottenute con il metodo dei nuclidi cosmogenici nel fronte esterno-avanfossa dell’appennino settentrionale e relative agli ultimi 0,7 ma (cyr & granger, 2008). i valori del tasso di erosione risultano marcatamente inferiori alle velocità di esumazione registrate dalle unità tettoniche originariamente profonde affioranti nell’area di studio. dai dati termocronometrici, infatti, si desume per le unità lagonegresi e la piattaforma apula, affioranti rispettivamente nell’area del m. sirino e al m. alpi, un tasso di esumazione mediamente superiore a 1 mm/a negli ultimi 2–3 ma circa (tab. 2). la differenza tra i valori dei tassi di esumazione e di erosione è in parte imputabile al metodo utilizzato nella valutazione dell’erosione. con tale metodo, infatti, non viene contemplato il contributo del weathering chimico all’erosione che, pertanto, ne risulta lievemente sottostimata, come suggerisce un analogo studio riguardante la regione alpina (vernon et al., 2008). tuttavia, la differenza tra i ratei di esumazione ed erosione, che è compresa tra 0,6 e 1,3 mm/a (tab. 2), risulta troppo elevata in rapporto all’entità dei tassi di denudazione valutati non solo per l’area di studio ma per l’intera dorsale appenninica, per essere imputata ai limiti del metodo. in alternativa, tale discrepanza è interpretabile come espressione del fatto che l’erosione ha contribuito solo in parte all’esumazione delle unità strutturali più profonde dell’edificio orogenico, la cui venuta a giorno appare essere stata fortemente condizionata da fenomeni di tettonica estensionale, come proposto da mazzoli et al., 2008). 5. considerazioni conclusive pur con i limiti imposti dal metodo utilizzato, questo studio costituisce il tentativo di quantificare, sulla base di vincoli ed analisi di tipo geologico e morfotettonico, gli effetti dell’erosione all’interno della catena sudappenninica. tra i dati raccolti, quelli derivanti dall’analisi della natura dei clasti delle successioni conglomeratiche ha mostrato che, nel plio-quaternario, il bsa ha registrato l’unroofing dell’edificio orogenico. in particolare, si è riscontrata testimonianza della presenza in superficie, nel corso del pleistocene inferiore, della gran parte delle unità strutturali più profonde; non si sono raccolti indizi sulla venuta a giorno della più profonda delle unità affioranti (la piattaforma apula), la cui successione costituisce il m. alpi, per la difficoltà di riconoscere la firma litologica dei relativi terreni. la testimonianza della presenza in affioramento di successioni a diverso grado di erodibilità consente di ritenere che, almeno dal pleistocene inferiore, l’erosione si è distribuita in modo disomogeneo. al tasso di erosione risultante da questo studio, pertanto, non può essere associato un parallelo abbassamento della superficie topografica che, invece, diveniva via via più accidentata. la confrontabilità tra i valori finora ottenuti con diversi approcci evidenzia come, nel lungo termine (intervalli nell’ordine di 105 a) e su aree vaste (nell’ordine di 103 km2), la rilevanza dell’influenza esercitata sui processi di erosione da fattori locali quali quelli litologici o morfologici tenda a divenire trascurabile. i valori del tasso di erosione finora ottenuti, che, nel complesso, ricoprono una finestra temporale corrispondente all’ultimo milione di anni, appaiono descrivere in modo adeguato l’erosione che ha interessato l’intera dorsale appenninica nel quaternario, ovvero lungo un arco di tempo in cui il clima registrava forti fluttuazioni e quando la catena era già connotata da terreni a disomogenea erodibilità. inoltre, il confronto di tali valori con quelli derivanti dalla regione alpina e relativi agli ultimi milioni di anni (vernon et al., 2008), che risultano più elevati di quelli valutati per l’area appenninica, sottolinea che il rilievo locale esercita un importante controllo sulla velocità con cui agiscono i processi erosionali. i risultati di questo studio, infine, evidenziano l’importante contributo esercitato dalla componente legata alla tettonica estensionale nei processi esumativi occorsi, nella regione sudappenninica, negli ultimi 2-3 ma. ringraziamenti gli autori desiderano ringraziare i revisori anonimi ed il dott. andrea sposato, della redazione de "il quaternario", per gli utili suggerimenti, che hanno permesso di migliorare questo lavoro. 86 tab. 2 confronto tra il tasso medio di erosione ottenuto per l’area di studio ed i tassi di esumazione delle unità tettoniche originariamente profonde, affioranti dei settori assiali dell’appennino meridionale. 1dati da mazzoli et al. (2006; 2008). the average erosion rate in the study area compared with the exhumation rates of formerly deeply buried tectonic units, outcropping in the study area. 1 data from mazzoli et al. (2006; 2008). a. capalbo et al. lavori citati ahnert f. (1970) functional relationships between denudation, relief, and uplift in large mid-latitude basins – am. jour. sci., 268, pp. 243–263. adams b., dietsch c., owen l.a., caffee m.w., spotila j., haneberg w.c. (2009) exhumation and incision history of the lahul himalaya, northern india, based on (u–th)/he thermochronometry and terrestrial cosmogenic nuclide methods geomorphology, 107, pp. 285–299. amato a., aucelli p.p.c. & cinque a. (2003) the long – term denudation rate in the southern apennines chain (italy): a gis – aided estimation of the rock volumes eroded since middle pleistocene time – quat. int., 101-102, pp. 3–11. amato a. & cinque a. (1992) il bacino plio-pleistocenico di calvello (potenza): evoluzione geologica e geomorfologica studi geol. camerti, vol. spec. 1992/1, pp. 181-189. amato a. & cinque a. (2000) erosional landsurfaces of the campano-lucano apennines (s. italy): genesis, evolution, and tectonic implications tectonophysics, 315, pp. 251-267. amato a., cinque a. & santangelo n. (1995) il controllo della struttura e della tettonica plio-quaternaria sull’evoluzione del reticolo idrografico dell’appennino meridionale studi geol. camerti, vol. spec. 1995/2, pp. 23-30. amore f.o., ciampo g., di donato v., esposito p., santini u. & staiti d. (1996) biostratigraphy of the plio-pleistocene calvello basin (potenza, italy) mem. soc. geol. it., 51, pp. 1153-1163. ascione a., cinque a., santangelo n. & tozzi m. (1992) il bacino del vallo di diano e la tettonica trascorrente plio – quaternaria: nuovi vincoli cronologici e cinematica studi geol. camerti, vol. spec. 1992/ 1, pp. 201–208. ascione a. & cinque a. (1999) tectonics and erosion in the long term relief history of the southern apennines (italy) z. geomorphol. n. f., supp. bd. 118, pp. 1-16. benvenuti m., bonini m., moratti g. & sani f. (2006) tectonosedimentary evolution of the plio – pleistocene sant’arcangelo basin (southern apennines, italy) in moratti, g. & chalouan, a. (eds.), tectonics of the western mediterranean and north africa. geol. soc. london, spec. publ., 262, pp. 289–322. brancaccio l., cinque a., romano p., rosskopf c., russo f., santangelo n. & santo a. (1991) geomorphology and neotectonic evolution of a sector of the tyrrhenian flank of the southern apennines (region of naples, italy) z. geomorph., suppl. -bd. 82, pp. 47-58. butler r.w.h., mazzoli s., corrado s., de donatis m., di bucci d., gambini r., naso g., nicolai c., scrocca d., shiner p. & zucconi v. (2004) applying thick – skinned tectonic model to the apennine thrust belt of italy: limitations and implications in mcclay, k.r. (ed.), thrust tectonics and hydrocarbon system. a.a.p.g. memoir, 82, pp. 647-667. caggianelli a., dellino p. & sabato l. (1992) depositi lacustri infrapliocenici con intercalazioni vulcanoclastiche (bacino di sant’arcangelo, basilicata) il quaternario, 5 (1), pp. 123-132. caiazzo c., ascione a. & cinque a. (2006) late tertiary–quaternary tectonics of the southern apennines (italy): new evidences from the tyrrhenian slope tectonophysics, 421, pp. 23–51. caldara m., loiacono f., morlotti e., pieri p. & sabato l. (1988) i depositi della parte nord del bacino di s. arcangelo (appennino lucano): caratteri geologici e paleoambinetali mem. soc. geol. it., 41, pp. 391–410. carbone s., catalano s., lazzari s., lentini f. & monaco c. (1991) presentazione della carta geologica del bacino del fiume agri (basilicata) mem. soc. geol. it., 47, pp. 129-143. castradori d. (1993) calcareous nannofosils and the origin of eastern mediterranean sapropels paleoceanography, 8, pp. 459–471. cavinato g.p., petronio c. & sardella r. (2001) the mercure river basin (southern italy): quaternary stratigraphy and large mammal biochronology the world of elephants international congress, rome 2001, abstracts, pp. 187-190. cello g., guerra i., tortorici l., turco e. & scarpa r. (1982) geometry of the neotectonic stress field in southern italy: geological and seismological evidence – jour. struct. geol., 4, pp. 385–393. cinque a. (1992) distribuzione spazio – temporale dei movimenti tettonici verticali nell’appennino campano – lucano: alcune riflessioni studi geol. camerti, vol. spec. 1992/1, pp. 33–38. cinque a., patacca e., scandone p. & tozzi m. (1993) quaternary kinematic evolution of the southern apennines, relationships between surface geological features and deep lithospheric structures – ann. geof., 36, pp. 249–260. cohen p. (1965) water resource of the humboldt river valley near winnemucca, nevada. u.s. geological survey water supply papers 1975. cyr a.j. & granger d. (2008) dynamic equilibrium among erosion, river incision, and coastal uplift in the northern and central apennines, italy geology, 36(2), pp. 103–106. davis s.n. (1969) porosity and permeability in natural materials. in dewiest r.j.m. (ed), flow through porous media, pp. 53-89. new york academic press. di niro a., giano s.i. & santangelo n. (1992) primi dati sull’evoluzione geomorfologica e sedimentaria del bacino dell’alta val d’agri (basilicata) studi geol. camerti, vol. spec. 1992/1, pp. 257–263. england p. & molnar p. (1990) surface uplift, uplift of rocks, and exhumation of rocks geology, 18, pp. 1173–1177. filocamo f. (2007) evoluzione quaternaria del margine tirrenico dell'appennino meridionale tra il golfo di sapri e la foce del fiume lao: studio stratigrafico e geomorfologico tesi di dottorato, università degli studi di napoli “federico ii”, 340 pp. (http://www.fedoa.unina.it). filocamo f., romano p., di donato v., esposito p., mattei m., porreca m., robustelli g. & russo ermolli e. (2009) geomorphology and tectonics of uplifted coasts: new chronostratigraphical constraints for the quaternary evolution of tyrrhenian north 87valutazione del tasso di erosione ... calabria (southern italy) geomorphology, 105, pp. 334–354. foster d.a. & john b.e. (1999) quantifying tectonic exhumation in an extensional orogen with thermochronology: examples from the southern basin and range province in ring u. et al. (eds), exhumation processes: normal faulting, ductile flow and erosion. london, geol. spec. publ., 154, pp. 343-364. gilchrist a.r., summerfield m.a. & cockburn h.a.p. (1994) landscape dissection, isostatic uplift and the morphologic development of orogens geology, 22, pp. 963–966. giannandrea p. & loiacono f. (2003) le successioni alluvionali e lacustri quaternarie affioranti nella media valle del fiume sinni (appennino meridionale, basilicata) il quaternario, 16 (2), pp. 257–267. granger d.e. kirchner j.w. & finkel r. (1996) spatially averaged long-term erosion rates measured from in situ-produced cosmogenic nuclides in alluvial sediments – jour. geol., 104, pp. 249–257. hippolyte j-c., angelier j., roure f. & müller c. (1991) géométrie et mécanisme de formation d’un basin “piggyback”: le basin de sant’arcangelo (italie méridionale) c.r. acad. sci., 312 (2), pp. 1373–1378. hippolyte j-c., angelier j., roure f. & casero p. (1994a) piggyback basin development and thrust belt evolution: structural and palaeostress analyses of plio – quaternary basin in the southern apennines – jour. struct. geol., 16 (2), pp. 159–173. hippolyte j-c., angelier j. & roure f. (1994b) a major geodynamic change revealed by quaternary stress patterns in the southern apennines (italy) tectonophysics, 230, pp. 199–210. iannace a., bonardi g., d’errico m., mazzoli s., perrone v. & vitale s. (2005) structural setting and tectonic evolution of the apennine units of northern calabria c.r. geosci., 337 , pp. 1541–1550. karner d.b., juvigné e., brancaccio l., cinque a., russo ermolli e., santangelo n., bernasconi s. & lirer l. (1999) a potential early middle pleistocene tephrostratotype for the mediterranean basin: the vallo di diano, campania, italy global planet. change, 21, pp. 1-15. kuhlemann j., frisch w., szekely b., dunkl i. & kazmer m. (2002) post-collisional sediment budget history of the alps: tectonic versus climatic control int. j. earth sci., 91, pp. 818–837. la rocca s. & santangelo n. (1991) nuovi dati sulla stratigrafia e sull’evoluzione geomorfologica del bacino lacustre pleistocenico del fiume noce (basilicata) geogr. fis. dinam. quat., 14 (2), pp. 229–242. maccary l.m. & lambert t.w. (1962) recoinnassance of ground-water resources of the jackson purchase region, kentucky. u.s. geological survey hydrologic atlas ha-13. manckletow n. (1985) the simplon line, a majow displacement zone in the western lepontine alps eclogae geol. helveticae, 78, pp. 73-96. marino m. (1994) biostratigrafia integrate a nannofossili calcarei e foraminiferi planctonici di alcune successioni terrigene pliocenico – superiori del bacino di sant’arcangelo (appennino meridionale) boll. soc. geol. it., 113, pp. 329–354. mattei m., pretocelli v., lacava d. & schiattarella m. (2004) geodynamic implication of pleistocene ultrarapid vertical – axis rotation in the southern apennines, italy geology, 32 (9), pp. 789-792. mazzoli s., aldega l., corrado s., invernizzi c. & zattin m. (2006) pliocene-quaternary thrusting, synorogenic extension and tectonic exhumation in the southern apennines (italy): insights from the monte alpi area in mazzoli s. & butler r.w.h. (eds), styles of continental contraction. geol. soc. am., spec. paper, 414, pp. 55-77. mazzoli s., d’errico m., aldega l., corrado s., invernizzi c., shiner p. & zattin m. (2008) tectonic burial and “young” (<10 ma) exhumation in the southern apennines fold-and-thrust belt (italy) geology, 36 (3), pp. 243-246. meinzer o.e. (1923) the occurrence of groundwater in the united states, with a discussion principles. u.s. geological survey water-supply paper 489. montgomery d.r. & brandon m.t. (2002) topographic control on erosion rates in tectonically active mountain ranges earth planet. sci. letters, 201, pp. 481–489. moores e.m. scott r.b. & lumsden w.w. (1968) tertiary tectonics of the white pine-grant range region, east-central nevada, and some regional implications – geol. soc. am. bull., 79, pp. 17031726. patacca e., sartori r. & scandone p. (1990) tyrrhenian basin and apenninic arcs: kinematic relations since late tortonian times mem. soc. geol. ital., 45, pp. 425-451. patacca e. & scandone p. (2001) late thrust propagation and sedimentary response in the thrust-beltforedeep system of the southern apennines (pliocene-pleistocene) in vai g.b. & martini i.p. (eds), anatomy of an orogen: the apennines and adjacent mediterranean basins, kluwer acad., norwell, mass., pp. 401-440. pieri p., sabato l., loiacono f. & marino m. (1994) il bacino piggyback di sant’arcangelo: evoluzione tettonico-sedimentaria boll. soc. geol. it., 113, pp. 465-481. pienet n. & soriau m. (1988) continental erosion and large scale relief tectonics, 7, pp. 563–582. rio d., raffi i. & villa g. (1990) pliocene – pleistocene nannofossil distribution patterns in the western mediterranean in kastens k.a., mascle, j. et al. (eds), proc. ocean drill. prog., sci. results, 107, college station, tx, pp. 513–533. russo f. & schiattarella m. (1992) osservazioni preliminari sull’evoluzione morfostrutturale del bacino di castrovillari (calabria settentrionale) studi geol. camerti, vol. spec. 1992/1, pp. 271–278. sabato l., bertini a., masini f., albianelli a., napoleone g. & pieri p. (2005) the lower and middle pleistocene geological record of the san lorenzo lacustrine succession in the sant’arcangelo basin (southern apennines, italy) – quat. int., 131, pp. 59-69. salustri galli c., torrini a., doglioni c. & scrocca d. (2002) divide and highest mountains vs subduc88 a. capalbo et al. tion in the apennines studi geol. camerti, 1, pp. 143-153. santangelo n. (1991) evoluzione stratigrafica, geomorfologica e neotettonica di alcuni bacini lacustri del confine campano lucano (italia meridionale) tesi di dottorato, università degli studi di napoli “federico ii”, 109 pp. sartori r. (1990) the main results of odp leg 107 in the frame of neogene to recent geology of perytyrrhenian areas in kastens, k.a., mascle, j. et al. (eds.), proc. ocean drill. prog., sci. results, 107, college station, tx, pp. 715–730. schiattarella m., torrente m.m., & russo f. (1994) analisi strutturale ed osservazioni morfostratigrafiche nel bacino del mercure (confine calabro – lucano) il quaternario, 7 (2), pp. 613–626. selverstone j. (1988) evidence for east-west crustal extension in the eastern alps: implications for the unroofing history of the tauern window tectonics, 7, pp. 87-105. shiner p., beccaccini a. & mazzoli s. (2004) thin–skinned versus thick–skinned structural models for apulian carbonate reservoir: constraints from the val d’agri fields, s apennines, italy – mar. petrol. geol., 21, pp. 805–827. turco e., maresca r. & cappadona p. (1990) la tettonica plio-pleistocenica del confine calabro-lucano: modello cinematico mem. soc. geol. it., 45, pp. 519-529. vernon a.j., van der beek p.a., sinclair h.d. & rahn m.k. (2008) increase in late neogene denudation of the european alps confirmed by analysis of a fission-track thermochronology database earth planet. sci. lett., 270, pp. 316–329. vezzani l. (1967a) il bacino plio–pleistocenico di s. arcangelo (lucania) atti acc. gioenia di scienze naturali, serie vi, 18, pp. 207–228. vezzani l. (1967b) la sezione stratigrafica pleistocenica di castronuovo di s. andrea (potenza) riv. it. paleont. strat., 13, pp. 11–59. zavala c. (2000) stratigraphy and sedimentary history of the plio-pleistocene sant’arcangelo basin, southern apennines, italy riv. it. paleont. strat., 106 (3), pp. 399-416. zuppetta a., russo m. & mazzoli s. (2004) miocene tectonic evolution of the southern apennine thrust front (italy): stratigraphic and structural constraints from the eastern calabria-lucania borderland area – geodin. acta, 17/2, pp. 141-151. 89 ms. ricevuto il 10 dicembre 2009 testo definitivo ricevuto il 13 aprile 2010 ms. received: december 10, 2009 final text received: april 13, 2010 valutazione del tasso di erosione ... available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 105 108 climatic and oceanographic changes in the azores region during the last 74.7 ka alessandro bonfardeci 1, antonio caruso 1, annachiara bartolini 2, franck bassinot 3, marie-madeleine blanc-valleron 2 1 dipartimento di scienze della terra e del mare, università degli studi di palermo, palermo, italy 2 cnrs umr 7207 cr2p, mnhn, paris, france 3 institut pierre-simon laplace, lab. des sciences du climat et de l'environnement, umr8212, cea-cnrs-uvsq, gif-sur-yvette, france corresponding author: a. bonfardeci <alessandro.bonfardeci@unipa.it> abstract: in this study, we reconstruct the complex palaeoclimatic and palaeohydrographic history of the north atlantic ocean during the upper pleistocene-holocene, through a high-resolution globigerinoides ruber globigerinoides elongatus plexus study. the studied core (ata13-of-kt1) was collected southwest of the azores islands near the present-day boundary of the subtropical gyre/azores front current system (stg/afcs). quantitative and stable isotope data of the g. ruber g. elongatus plexus chromotypes and selected morphotypes showed cyclic oscillations of the stg/afcs boundary linked to climatic variability at orbital and millennial scales, during the last 74.7 ka. keywords: foraminifera, stable isotopes, palaeoclimatology, palaeoceanography, subtropical gyre, azores front/current system 1. introduction the atlantic meridional overturning circulation (amoc) is known to be the surface and deep-water movements system that controls the north atlantic hydrography (fig. 1; lynch-stieglitz et al., 2007; bonfardeci et al., 2018). the azores current (ac), originating as the eastern branch of the gulf stream, flows to the south of the azores archipelago throughout the year, centred at 34°n (schiebel et al., 2002a-b). this current is limited to the north by the so-called azores front (af) that separates the warmer and oligotrophic waters belonging to the subtropical gyre (stg) from the northernmost colder and nutrient-rich eastern north atlantic central water (enacw) (gould, 1985; schiebel et al., 2002a-b; schwab et al., 2012; repschläger et al., 2015). moreover, the ac represents the main surface waters input for the mediterranean basin and its intensity is strongly forced by the mediterranean outflow water (mow) (schwab et al., 2012). globigerinoides ruber (d’orbigny, 1839) gr. alba and rosea, and globigerinoides elongatus (d’orbigny, 1826) are common species in tropical/subtropical biogeographic provinces (bé and torderlund, 1971; bé, 1977) and they have been extensively used to reconstruct past sea-surface temperature and salinity. however, these two species exhibit morphological variability linked to different environmental conditions (aurahs et al., 2011; schiebel & hemleben, 2017). in this study, we test the link between environmental conditions and morphological variability of the g. ruber g. elongatus plexus and its response to climatic changes at orbital and millennial-scale (bonfardeci et al., 2018). the main aim of this work was to analyse latitudinal shifts in the subtropical gyre/azores front current system (stg/ afcs), using the quantitative abundance and isotopic variations of the different g. ruber g. elongatus (eco-) morphotypes as sensors. 2. material and methods the ata13-of-kt1 core (35°24.956’n 37° 15.749’w; bathymetry= 3,431 m; length= 4.03 m), collected with a kullenberg gravity corer during the oceanograflu 2013 cruise, was sub-sampled every 1 cm, with a total of 402 samples. the quantitative analyses on g. ruber g. elongatus plexus of ata13-of-kt1 core were performed on the >125 and 250-315 μm size-fractions. stable isotope analyses were performed every 2 centimetres, in the size -fraction 250-315 μm, on about ten specimens of g. ruber s.s., whereas further analyses on different morphotypes were carried out in two strategic intervals: 0-18.5 cmbsf and 42.5-60.5 cmbsf (bonfardeci et al., 2018). the isotope analyses were performed at the lsce (laboratoire des sciences du climat et de l’environnement gif-sur-yvette, france). 3. results for the age model developing four ams 14c dating and the δ18o g. ruber s.s. record were combined. the ams 14c analyses were preferentially carried out on surfacedwelling species (globigerinoides spp.). a reservoir age correction (rsurf) of 400 a was used, except for the 39-40 cmbsf level, corresponding to the heinrich event 1 (h1), where a rsurf of 800 was adopted (bard et al., 1998; siani et al., 2001). according to the tuning strategy, g. https://doi.org/10.26382/aiqua.2018.aiquaconference mailto:alessandro.bonfardeci@unipa.it� ruber gr. alba and δ18og.ruber s.s. maxima and minima were aligned to the ngrip δ18o (north greenland ice core project members, 2004) and the md95-2042 δ18og. bulloides records (lisiecki & stern, 2016). mean sedimentation rate of 5.6 cm ka-1 (temporal resolution of 178.5 a cm-1) was calculated, with an uncertainty of 2-3 ka (lisiecki & stern, 2016). the time interval covered by the ata13-of-kt1 core record spans from 74.7 to 2.75 ka bp (bonfardeci et al., 2018). the d18o g. ruber s.s. reached maxima values (from 2.1 to 0.8‰) during mis 4 and 2 stages (fig. 2), whereas decreased in correspondence with warmer mis 1 and mis 5.1 phases (from 1.7 to 0.4‰). high frequency/low amplitude fluctuations observed in the d18og.ruber s.s. record were linked to sub-orbital climatic oscillations, such as heinrich and dansgaard-oeschger events. g. ruber gr. alba increased in abundance during warm climate phases (mis 5.1 and mis 1) with maxima percentages (10-20 %) during the holocene (fig. 2), whereas minima (2-12.5 %) were observed during mis 4 and miss 3.1/2 transition. within the g. ruber g. elongatus population, g. elongatus became dominant (up to 50 %) during warmer periods (miss 5.1, 3.3, 3.1 and 1) and during the bølling/allerød–younger dryas interval, g. ruber cyclostoma type reached maximum abundances during insolation minima and glacial periods (mis 4 and mis 2), with a remarkable peak for h7, and it was almost absent in interglacial mis 5.1 and especially in mis 1 (bonfardeci et al., 2018). 4. discussion and conclusions abundance fluctuations of g. ruber gr. (alba and rosea), as well as of the g. ruber g. elongatus plexus morphotypes, testify that the azores region climate and hydrography were strictly controlled by orbital and suborbital forcing, during the last 74.7 ka. in particular, g. ruber gr. (alba and rosea) reached highest abundance during climatic phases in which the insolation signal was closely in phase with the obliquity (laskar et al., 2004). therefore, this latter group of species has been used as monitor for the expansion/reduction of the north atlantic stg (repschläger et al., 2015; bonfardeci et al., 2018). g. ruber gr. alba (fig. 2) increases in abundance, coeval with δ18og. ruber s.s. lightening, indicate that during the final part of mis 5 and the holocene the azores region was interested by warmer, stratified and oligotrophic surface waters, due to the stg expansion. conversely, during the glacial stages (miss 4 and 2) and the heinrich events, cooler, nutrient-richer and saltier waters, forced by stg reduction, dominated this region, as testified by g. ruber gr. alba decreases and δ18og. ruber s.s. weighting (bonfardeci et al., 2018). analysing the quantitative distribution of each ecomorphotype in the g. ruber g. elongatus plexus, g. ruber cyclostoma type represents the best cooler waters indicators, reaching maxima abundance during the miss 4 and 2, whilst g. elongatus, increasing in abundance during interglacial periods (latest part of mis 5.1 and mis 1), can be considered as the best warmer waters indicator in the azores region. according to bonfardeci et al., (2018), the difference between the amount of g. elongatus and g. ruber cyclostoma type represents a 106 fig. 1 present north atlantic surface hydrography and ata13-of-kt1 core location (modified from bonfardeci et al., 2018). gs=gulf stream; nac=north atlantic current; ac=azores current; af=azores front; pc=portuguese current; cc=canary current; mow=mediterranean outflow water; stg=subtropical gyre; enacw= eastern north atlantic central water. bonfardeci a. et al. 107 powerful tool to track stg expansion/reductions and related stg/afcs boundary latitudinal shifts (fig. 2). references aurahs r., treis y., darling k., kucera m. (2011) a revised taxonomic and phylogenetic concept for the planktonic foraminifer species globigerinoides ruber based on molecular and morphometric evidence. marine micropalaeontology, 79, 1-14. bard e., arnold m., hamelin b., tisnerat-laborde n., cabioch g. (1998) radiocarbon calibration by means of mass spectrometric 230th/234u and 14c ages of corals: an updated database including samples from barbados, mururoa and tahiti. radiocarbon, 40(3), 1127-1151. fig. 2 stg/ac-boundary position (% g. elongatus-g. ruber cyclostoma type), g. ruber gr. alba (125 μm size fraction) and δ18o g. ruber s.s.. records of ata13-of-kt1 core record (modified from bonfardeci et al., 2018). these latter records are compared to the 21 june insolation at 65°n (red curve) and obliquity (black curve) signals, calculated for the interval between 74.7 and 0 ka bp (laskar et al., 2004), as well as to the md95-2042 δ18o g. bulloides (lisiecki and stern, 2016) record. grey vertical bars refer to the glacial stages (miss 2 and 4) and cool-temperate sub-stage mis 3.2 (light grey). h= heinrich event (heinrich, 1988; lisiecki and stern, 2016); red numbers= dansgaard/ oeschger (d/o) events (dansgaard et al., 1993; north greenland ice core project members, 2004; lisiecki and stern, 2016); yd= younger dryas stadial; b/a= bølling/allerød interstadial. paleoenvironmental reconstruction of the last 74.7 ka bé a.w.h., tolderlund d.s. (1971) distribution and ecology of living planktonic foraminifera in surface waters of the atlantic and indian oceans. in the micropalaeontology of the oceans (eds. b. h. funnell and w. r. riedel). cambridge univ. press, london, 105-149. bé a.w.h. (1977) an ecological, zoogeographic and taxonomic review of recent planktonic foraminifera, in: a.t.s. ramsey (eds.), oceanic micropalaeontology. london: academic press, 1, 1-100. bonfardeci a., caruso a., bartolini a., bassinot f., blanc-valleron m.m. (2018) distribution and ecology of the globigerinoides ruberglobigerinoides elongatus morphotypes in the azores region during the late pleistocene holocene. palaeogeography, palaeoclimatology, palaeoecology, 491, 92-111. dansgaard w., johnsen s.j., clausen h.b., dahljensen d., gundestrup n.s., hammer c.u., hvidberg c.s., steffensen j.p., sveinbjörnsdottir a.e., jouzel j., bond g. (1993) evidence for general instability of past climate from a 250-kyr ice-core record. nature, 364, 218-220. gould w.j. (1985) physical oceanography of the azores front. progress in oceanography, 14, 167190. heinrich h. (1988) origin and consequences of cyclic ice rafting in the northeast atlantic ocean during the past 130,000 years. quaternary research, 29, 142-152. laskar j., robutel p., joutel f., gastineau m., correia a.c.m., levrard b. (2004) a long-term numerical solution for the insolation quantities of the earth. astron. astrophys., 428, 261-285. lisiecki l.e., stern j.v. (2016) regional and global benthic 18o stacks for the last glacial cycle. paleoceanography, 31, 1368-1394. lynch-stieglitz j., adkins j.f., curry w.b., dokken t., hall i.r., herguera j.c., hirschi j.j. m., ivanova e.v., kissel c., marchal o., marchitto t.m., mccave i.n., mcmanus j.f., mulitza s., ninnemann u., peeters f., yu e.f., zahn r. (2007) atlantic meridional overturning circulation during the last glacial maximum. science, 316, 66 -69. north greenland ice core project members (2004) high-resolution record of northern hemisphere climate extending into the last interglacial period. nature, 431(7005), 147-151. repschläger j., weinelt m., kinkel h., anderesen n., garbe-schönberg d. (2015) response of the subtropical north atlantic surface hydrography on deglacial and holocene amoc changes. paleoceanography, 30(5), 456-476. schiebel r., waniek j., zeltner a., alves m. (2002a) impact of the azores front on the distribution of planktic foraminifers, shelled gastropods, and coccolithophorids. deep sea research part ii, 49(19), 4035-4050. schiebel r., schmuker b., alves m., hemleben c. (2002b) tracking the recent and late pleistocene azores front by the distribution of planktic foraminifers, j. mar. syst., 37(1-3), 213-227. schiebel r., hemleben c. (2017) planktic foraminifers in the modern ocean. springer, berlin, heidelberg schwab c., kinkel h. weinelt, m., repschläger, j. (2012) coccolithophore paleoproductivity and ecology response to deglacial and holocene changes in the azores current system, paleoceanography, 27, pa3210. siani g., paterne m., michel e., sulpizio r., sbrana a., arnold m., haddad g. (2001) mediterranean sea surface radiocarbon reservoir age changes since the last glacial maximum. science, 294, 19171920. 108 bonfardeci a. et al. ms. received: may 11, 2018 final text received: may 18, 2018 << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /none /binding /left /calgrayprofile (dot gain 20%) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /error /compatibilitylevel 1.4 /compressobjects /tags /compresspages true /convertimagestoindexed true /passthroughjpegimages true /createjobticket false /defaultrenderingintent /default /detectblends true /detectcurves 0.0000 /colorconversionstrategy /cmyk /dothumbnails false /embedallfonts true /embedopentype false /parseiccprofilesincomments true /embedjoboptions true /dscreportinglevel 0 /emitdscwarnings false /endpage -1 /imagememory 1048576 /lockdistillerparams false /maxsubsetpct 100 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/hrv (za stvaranje adobe pdf dokumenata najpogodnijih za visokokvalitetni ispis prije tiskanja koristite ove postavke. stvoreni pdf dokumenti mogu se otvoriti acrobat i adobe reader 5.0 i kasnijim verzijama.) /hun 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/pdfxoutputintentprofileselector /documentcmyk /preserveediting true /untaggedcmykhandling /leaveuntagged /untaggedrgbhandling /usedocumentprofile /usedocumentbleed false >> ] >> setdistillerparams << /hwresolution [2400 2400] /pagesize [612.000 792.000] >> setpagedevice amq abs rossato et al tepro 239-242.pub available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, abstracts, aiqa 13-14/06/2018 florence, 239 242 post-lgm catastrophic landslides in the dolomites: when, where and why sandro rossato1, silvana martin1, susan ivy-ochs2, alfio viganò3, christof vockenhuber2, manuel rigo1, nicola surian1, paolo mozzi1 1 university of padova department of geosciences, padova, italy 2 laboratory of ion beam physics, eth-honggerberg, zürich, switzerland 3 servizio geologico della provincia autonoma di trento, trento, italy corresponding author: s. rossato <sandro.rossato@unipd.it> abstract: this paper aims to present the state-of-the-art about large and catastrophic landslides that have occurred in the dolomites since the last glacial maximum (lgm). such events have been proved to happen multiple times in the same area, in correspondence of prolonged rainfall events, ice/snow melting and seismic shakings. predisposing factors, such as rock fracturation and vertical bedding strata, may accumulate rock fatigue and induce the formation/weathering of shear planes, weakening the rock mass and allowing lowmagnitude events to trigger the movement. keywords: cosmogenic 36cl, geological risk and hazard, geomorphic hazard, dolomites 1. introduction landslides are phenomena that can deeply affect both natural and anthropogenic landscapes, and they can represent a serious risk (e.g. petley, 2012). understanding their predisposing factors and potential triggers is of utmost importance to reduce their potential impacts, especially in the alps where narrow valleys are increasingly inhabited (e.g. huggel et al., 2012). in the last three decades, it has been estimated that the costliest natural event occurred in italy was the notorious val pola rock avalanche, occurred on 28th july 1987. it has been estimated that the total amount of damages reached us$ 400 million (crosta et al., 2004). in the alps, the largest landslides were presumed to have occurred during the latest phases of the last glacial maximum (lgm), or within a few millennia after deglaciation as a response to glacial unloading of valley slopes. recently, some of them, such as “lavini di marco”, (martin et al., 2014), “marocche di dro” (ivyochs et al., 2017a), “castelpietra” (ivy-ochs et al., 2017b) and “mt. peron” (rossato et al., submitted), have been isotopically dated, proving to be holocene in age, thus suggesting that such large events may occur without major changes in the equilibrium of the slopes. in the dolomites several landslides occurred, such as the fadalto, antelao and vajont events, causing damages and casualties, even when the moving masses were small. the vajont event hit the headlines all over europe for its disruptiveness, being the most catastrophic events in the study area, but other large landslides occurred in the past. here we summarize the largest and most catastrophic landslides in the dolomites, focusing on their type, timing and impact on human life/activities, discussing their possible predisposing and triggering factors. we will not discuss deep-seated gravitational slope deformations and creep deformations, since they are characterized by relatively low deformation rates. 2. catastrophic dolomites landslides all landslides occurred in the dolomitic area that are relevant in terms of volume and/or impact on human activities are here presented (tab. 1) and shortly described based on the papers listed. 2.1. alta badia (borgatti & soldati, 2010) numerous events took place near corvara, since 10 ka cal bp to present. earth/mud/debris flows constitute most of the events, along with rotational rock slides. water availability, due to permafrost melting and/or rainfall events, is believed to be the potential trigger for these events and climatic conditions are believed to be the main cause of widespread landsliding. 2.2. alleghe (ermini & casagli, 2003) the alleghe event was a large (10 mm3) translational rock fall, possibly evolved into a rock avalanche. the debris mass reached a runup elevation of about 150 m above the valley bottom, on the opposite flank. a second, smaller (3 mm3) event took place some months after. both events have been linked to the high amount of rain and snow occurred during that winter. 2.3. antelao (montandon, 1933) on 21st april 1814, a large debris mass fall from the mt. antelao, split into two tongues and inundated the localities of taolen and marceana, causing 260 casualties. a temporary lake formed in the boite valley. this event was the most damaging of a sequence of landslides falling at the same place (e.g events are recorded also on 1348, 1729 and 1737 ad). 2.4. col mandro (montandon, 1933) in december 1933, a debris mass, detached from the col mandro, dammed the vanoi valley, forming a temporary lake. this event was the biggest of a sequence of mass movements in the area. it is believed https://doi.org/10.26382/aiqua.2018.aiquaconference that such events were due to deforestation and poor management of irrigation. 2.5. cortina d’ampezzo (borgatti & soldati, 2010) since 14 ka cal bp, in this area several events (earth flows and translational rock slides) have occurred. as for the alta badia case, climate is invoked as the possible driving factor, due to their clustering in specific time intervals. it is noteworthy that a single earthflow was triggered by the 15th september shock of the 1976 friuli earthquake sequence. 2.6. fadalto (pellegrini et al., 2006) this event is a large (135 mm3) and complex landslide involving various types of movements (rock slide, rock avalanche, debris slump, etc). it blocked the whole valley, forming the s. croce lake. the initial trigger is believed to be the relaxation of the slopes owing to glacier retreat, but the main scarp has been repeatedly reactivated since then. 2.7. la valle (montandon, 1933) in april 1701, a “rock avalanche” (this term may not correspond to its modern scientific meaning) detached from the mt. moschesin, causing 48 casualties. other minor events occurred later at the same place. 2.8. marziai (pellegrini et al., 2006) the rocky mass detached from mt. miesna, where rock layers are lightly dipping towards the slope and pervasive foliation is present. the landslide was suggested to have occurred in the first phase of deglaciation (i.e. 17-15 ka cal bp) by means of palynological data obtained from the remains of the temporary lake formed by the landslide itself. as for the fadalto landslide, the reaction of the slopes to glacier retreat is evoked as possible trigger. 2.9. monte salta (marcato et al., 2007) this rock avalanche, which occurred in 1674 ad, is strictly connected to the presence of major faulting, folding and fracturing of the rock mass, that dips steeply towards the slope. such an unstable setting makes the slopes prone to failure and the authors suggested that seismicity may be, or may have been, the trigger. 2.10. pecol (montandon, 1933) this event occurred in 1841 ad, evolved by steps during an entire week, causing various casualties and destroying an entire part of the village of pecol. 2.11. mt. peron (rossato et al., submitted) this enormous rock avalanche (170 mm3) fell from the top of mt peron and spread in the area where the villages of peron, ponte mas, vignole and roe are currently located. the event was believed to be lateglacial in age, but recent cosmogenic dates and historical data proved that it occurred during the roman era, prior to the 2nd century ad. 2.12. siror (montandon, 1933) this event was one of the many mass movements related to the occurrence of an earthquake on 25th january 1348. it detached from mt. belvedere and destroyed 240 table 1 summary table of the largest and most damaging (in terms of human lives) landslides in the dolomites. rossato s. et al. 241 the village of pubiaco, causing tens of casualties. 2.13. vajont (borgatti et al., 2004) the infamous, and extremely large, vajont event was due to the reactivation of an old landslide, after nearly three years of progressive creeping. on 9th october 1963, 270 mm3 of debris and rock mass fell into an artificial reservoir, forming a flood wave that wiped out the village of longarone, causing nearly 2000 casualties. 2.14. val cia (montandon, 1933) the rocky mass detached from the left flank of the cia valley in the 1882 ad, blocked the valley, and formed a temporary lake that breached soon after. the resulting flood, 4 mm3 large, affected the whole valley and propagated down to the vanoi valley. 2.15. valle san lucano (aldighieri et al., 2016) on 3rd december 1908 a landslide detached from the fourth pala di san lucano and buried pra and lagunàz villages, causing 28 casualties. unstable rock masses are still visible in the main scarp area. 3. predisposing and triggering factors the history of the dolomites documented several landslides that caused damages and casualties, even when the moving masses were small (e.g. valle san lucano). the vajont event hit the headlines all over europe for its disruptiveness, being the most catastrophic events occurred in the study area (borgatti et al., 2004). however, other similar events occurred in the past, but are less known due to their “limited” amount of losses (e.g. antelao) or old age (e.g. mt. peron). in some occasions, such landslides caused a radical change in the landscape, as the alleghe landslide: the debris mass blocked the cordevole river and induced the formation of the alleghe lake. such natural barrier has been artificially stabilized, and the lake is still present (draganits et al., 2014). catastrophic slope failures are often related to the presence of discontinuities in the rock mass, as faults, shear zones and joints (jaboyedoff et al., 2013; stead and wolter, 2015). favorable bedding of strata (e.g. mt. peron) and the presence of relict landslides (e.g. vajont) can concur to reduce the internal strength of the rock mass, contributing to the progressive accumulation of rock fatigue. the lower the energy required to break the equilibrium, the weaker the magnitude of the trigger event and the more probable the occurrence of forerunner events (loew et al., 2017). triggering events may be geological, hydrological, structural or even anthropogenic (cruden and varnes, 1996; wieczorek, 1996). prolonged and intense rainfalls are recognized to initiate movements, along with progressive failure, seismic shaking/volcanic activity, human activity or accelerating creep (keefer, 1993; di crescenzo and santo, 2005; adushkin, 2006; loew et al., 2017). catastrophic events may happen with (e.g. loew et al., 2017), or without a clear trigger or precursory events (e.g. dunning et al., 2006). the dolomites are disposed to earthquake activity, as the instrumental record testifies (up to ~mw=6.5; viganò et al., 2015), and seismicity has been classified as a possible trigger for numerous holocene large landslides in the alps (ivy-ochs et al., 2017a). only one of the considered events has been surely related to an earthquake, but there is a long record of seismicityrelated minor rockfalls and shallow landslides (borgatti & soldati, 2010). conversely, some authors highlighted a good correspondence between large dolomitic landslides (borgatti & soldati, 2010, rossato et al., submitted) and rainfall climatic events/phases occurred at various scales (e.g. tinner and kaltenrieder, 2005; benito et al., 2015; rossato et al., 2015). 4. conclusions as the predisposing factors (rock fracturation, vertical bedding strata, fracture planes cutting the stratigraphic sequence) and triggers (seismicity and/or rainfall events) are often still present after the landslide occur, there is a high likelihood of generating rock failures at the same place that may reach high magnitude. the dolomitic landslide record suggests that no exceptional event is required for large mass movements to happen, the continuing accumulation of predisposing factors lowering the energy needed to trigger them. lowmagnitude shakings, especially in combination with an increase of pore-pressure due to prolonged and intense rainfalls, may be enough to overcome the stability threshold. references adushkin v.v. (2006) mobility of rock avalanches triggered by underground nuclear explosions. landslides from massive rock slope failure, 267-284. aldighieri b., testa b., bertini a. (2016) 3d exploration of the san lucano valley: virtual geo-routes for everyone who would like to understand the landscape of the dolomites. geoheritage, 8(1), 77-90. benito g., macklin m.g., panin a., rossato s., fontana a., jones a.f., machado m.j., matlakhova e., mozzi p., zielhofer c. (2015) recurring flood distribution patterns related to short-term holocene climatic variability. scientific reports, 5, 16398. borgatti l., soldati m., carton a., corsini a., galuppo a., ghinoi a., marchetti m., oddone e., panizza m., pasuto a., pellegrini g.b., schiavon e., siorpaes c., surian n., tagliavini f. (2004) geomorphology and slope instability in the dolomites (northern italy): from lateglacial to recent geomorphological evidence and engineering geological applications. memorie descrittive della carta geologica d’italia 63(4). borgatti l., soldati m. (2010) landslides as a geomorphological proxy for climate change: a record from the dolomites (northern italy). geomorphology, 120(1), 56-64. crosta g.b., chen h., lee c.f. (2004) replay of the 1987 val pola landslide, italian alps. geomorphology, 60(1-2), 127-146. cruden d.m., varnes d.j. (1996) landslides: investi catastrophic landslides in the dolomites gation and mitigation. chapter 3-landslide types and processes. transportation research board special report, (247). di crescenzo g., santo a. (2005) debris slides–rapid earth flows in the carbonate massifs of the campania region (southern italy): morphological and morphometric data for evaluating triggering susceptibility. geomorphology, 66(1), 255-276. draganits e., grasemann b., janda c., hager c., preh a. (2014) 300mw baspa ii-india's largest private hydroelectric facility on top of a rock avalanchedammed palaeo-lake (nw himalaya): regional geology, tectonic setting and seismicity. engineering geology, 169, 14-29. dunning s.a., rosser n.j., petley d.n., massey c.r. (2006) formation and failure of the tsatichhu landslide dam, bhutan. landslides, 3(2), 107-113. ermini l., casagli n. (2003) prediction of the behaviour of landslide dams using a geomorphological dimensionless index. earth surface processes and landforms, 28(1), 31-47. huggel c., clague j.j., korup o. (2012) is climate change responsible for changing landslide activity in high mountains?. earth surface processes and landforms, 37(1), 77-91. ivy-ochs s., martin s., campedel p., hippe k., alfimov v., vockenhuber c., andreotti e., carugati g., pasqual d., rigo m., viganò a. (2017a) geomorphology and age of the marocche di dro rock avalanches (trentino, italy). quaternary science reviews, 169, 188-205. ivy-ochs s., martin s., campedel p., hippe k., vockenhuber c., carugati g., rigo m., pasqual d., viganò a. (2017b) geomorphology and age of large rock avalanches in trentino (italy): castelpietra. in workshop on world landslide forum, 347-353. springer, cham. jaboyedoff m., penna i., pedrazzini a., baroň i., crosta g.b. (2013) an introductory review on gravitational-deformation induced structures, fabrics and modeling. tectonophysics, 605, 1-12. keefer d.k. 1993) the susceptibility of rock slopes to earthquake-induced failure. bulletin of the association of engineering geologists, 30(3), 353-361. loew s., gschwind s., gischig v., keller-signer a., valenti g. (2017) monitoring and early warning of the 2012 preonzo catastrophic rockslope failure. landslides, 14(1), 141-154. marcato g., fujisawa k., mantovani m., pasuto a., silvano s., tagliavini f., zabuski l. (2007) evaluation of seismic effects on the landslide deposits of monte salta (eastern italian alps) using distinct element method. natural hazards and earth system sciences, 7(6), 695-701. martin s., campedel p., ivy-ochs s., viganò a., alfimov v., vockenhuber c., andreotti e., carugati g., pasqual d., rigo m. (2014) lavini di marco (trentino, italy): 36 cl exposure dating of a polyphase rock avalanche. quaternary geochronology, 19, 106-116. montandon f. (1933) chronologie des grands éboulements alpins du début de l’ère chrétienne à nos jours. matériaux pour l’étude des calamités, 32, 271-340. pellegrini g.b., surian n., albanese d. (2006) landslide activity in response to alpine deglaciation: the case of the belluno prealps (italy). geografia fisica e dinamica quaternaria, 29, 185-196. petley d. (2012) global patterns of loss of life from landslides. geology, 40(10), 927-930. rossato s., fontana a., mozzi p. (2015) meta-analysis of a holocene 14 c database for the detection of paleohydrological crisis in the venetian–friulian plain (ne italy). catena, 130, 34-45. rossato s., martin s., ivy-ochs s., viganò a., vockenhuber c., rigo m., de zorzi m., surian n., mozzi p. (submitted) the mt. peron rock avalanche (eastern alps): roman age not lateglacial. geomorphology. stead d., wolter a. (2015) a critical review of rock slope failure mechanisms: the importance of structural geology. journal of structural geology, 74, 123. tinner w., kaltenrieder p. (2005) rapid responses of high‐mountain vegetation to early holocene environmental changes in the swiss alps. journal of ecology, 93(5), 936-947. viganò a., scafidi d., ranalli g., martin s., della vedova b., spallarossa d. (2015) earthquake relocations, crustal rheology, and active deformation in the central-eastern alps (n italy). tectonophysics 661, 81-98. wieczorek g.f. (1996) landslide triggering mechanisms. landslides: investigation and mitigation, 247, 76-90. 242 rossato s. et al. ms. received: may 11, 2018 final text received: may 28, 2018 amq32(2) 117-130 furlanetto et al.pub ecological climatology along an elevational transect in the outer belt of the italian alps: modern pollen, vegetation and climate   giulia furlanetto1,2, lorena garozzo2, michele brunetti3, cesare ravazzi2 1 univ. of milano bicocca, dept. of environmental and earth sciences, milano, italy. 2 cnr institute for the dynamics of environmental processes (idpa), laboratory of palynology and palaeoecology, milano, italy. 3 cnrinstitute of atmospheric sciences and climate (isac), bologna, italy. corresponding author: g. furlanetto <g.furlanetto1@campus.unimib.it> abstract: montane vegetation is traditionally known to be particularly sensitive to climate changes. the strong elevational climatic gradient that characterizes mountain areas results in a steep ecological slope, with several ecotones occurring in a small area. modern pollen deposition is significantly predicted by both vegetation cover and pollen production; in turn, each predictor is significantly predicted by elevation and climate. analyses of modern pollen deposition are essential to calibrate fossil pollen sequences accounting for site topography and depositional process, and thus for pollen-based palaeoenvironment and palaeoclimate reconstructions. this study analyzes the relationships among modern pollen assemblages, vegetation and climate along an elevational gradient in the outer belt of the european alps. results of canonical correspondence analysis (cca) demonstrated a general good agreement with previous studies, which identified elevation as the main gradient in the variation of modern pollen and vegetation assemblages in elevational transects. modern pollen assemblages have been studied in pollen traps and moss samples from different vegetation communities along an elevational transect (stretching from 1240 to 2390 m asl), as well as the vegetation using the braun-blanquet system up to the 10 m radius scale, field vegetation surveys and aerial photographs for plant cover of the main species for larger surfaces. moss samples are assumed to record an average of several years of pollen deposition and can be profitably used as analogues for fossil pollen assemblages; while pollen traps can be expressed as pollen accumulation rates (par) and used as a modern reference to estimate past plant population densities. alnus viridis, the main woody species forming dwarf forests in the oceanic-type timberline ecotone, shows a specific elevational par arrangement under modern climate conditions. strong pollen producers (e.g. pinus sylvestris/mugo, picea, castanea, corylus and ostrya) display enhanced uphill wind-transport to subalpine and alpine zones leading to wider pollen belts with less defined boundaries than vegetation. to overcome these limitations, potential indicator pollen taxa of alpine/subalpine belts (vaccinium, rhododendron, loiseleuria) documented in this study and par of timberline species (e.g. alnus viridis) could be useful. thus, if it is possible to identify the major vegetation types and ecotones by means of their modern pollen deposition (e.g. timberline ecotone), other limits, poorly marked by changes in pollen dispersal (e.g. treeline) are not resolved by pollen proxies alone. keywords alps, elevational transects, modern pollen assemblages, vegetation, climate. available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 32 (2), 2019, 117 130 1. introduction ecological climatology is an interdisciplinary framework to understand the functioning of terrestrial ecosystems in the climate system (bonan, 2016). relationships between climate, ecosystems and forcing factors may be effectively understood by setting up training sets along ecogradients, and using proxies that allow to synthesize spatial variables such as vegetation (pollen proportions), terrestrial biomass (pollen accumulation rates), fire impact (number of fire events in the last 100 years), etc. in turn, analyses of modern training sets are essential for a better understanding of fossil palaeoecological records in a particular region, and thus for pollenbased palaeoenvironment and palaeoclimate reconstructions. the variability associated to modern pollen deposition sampled in an extended alpine calibration set responds mostly to july temperature (furlanetto et al., 2019), a climate variable strictly related to elevation. annual precipitation was instead found as the most significant climate variable for the armentarga fossil record covering the last 10.3 ka cal bp (furlanetto et al., 2018). nowadays annual precipitation is not significantly related to elevation as july temperature but is instead strongly controlled by regional climate (furlanetto et al., 2018). very few studies of modern pollen deposition have been attempted in mountain environments of southern european countries (court-picon et al., 2005, 2006; cañellas-boltà et al., 2009; ortu et al., 2010). moss samples are commonly used as surface samples for local modern pollen deposition. they are assumed to record an average of several years of pollen deposition (räsänen et al., 2004; pardoe et al., 2010; lisitsyna & https://doi.org/10.26382/amq.2019.08 118 furlanetto g. et al. hicks, 2014) and can be profitably used as analogues for fossil pollen assemblages. instead, pollen traps can be expressed both as percentages and pollen accumulation rates (par). par measurements can be used as a modern reference to estimate past plant population densities buffering the study site (hicks, 2001; tinner & theurillat, 2003; badino et al., 2018; furlanetto et al., 2018). modern references allow also the so-called “site calibration” to be defined, accounting for site-specific features affecting either climate parameters and pollen deposition, such as local topography and sedimentary processes, and the local influence of runoff and, most conspicuously, snow runoff on par, barely considered in traditional palaeoecological studies. the aim of this study is to investigate modern pollen assemblages-vegetation-climate relationships along an elevational gradient. this paper presents a new elevational transect developed in the upper brembana valley (orobie alps), recording a typical mid-latitude ecoclimatic elevational gradient under oceanic cold temperate climate (furlanetto et al., 2018). here modern pollen assemblages, vegetation and climate have been collected at 16 sampling sites placed along an elevational gradient stretching from 1240 m asl to 2390 m asl. the transect has been designed (1) to estimate the relationships linking modern assemblages, vegetation, elevation and climate; (2) to understand how is the modern vegetation reflected in modern pollen assemblages from pollen traps and moss samples; (3) to calculate specific elevational par arrangement under modern climate conditions; (4) to provide a robust modern reference for reliable palaeoenvironmental and quantitative interpretations of past vertical shifts and changes in vegetation composition, as recognized in the pollen records from high-elevation sites. 2. study area the upper brembana valley elevational transect extends along the uppermost section of a typical prealpine valley open to moist southern winds orographically forced uphill, between 1100 m and the headwalls at 2500-2700 m asl (fig. 1). this region is marked by a dfc climate accordingly to köppen-geiger classification (peel et al., 2007), i.e. nival, persistently wet throughout the year; locally, the annual temperature is 1.3 °c and july lapse rate ranges from 0.56 °c/100 m in the mountain belt to 0.77 °c/100 m above the open forest limit (furlanetto et al., 2019). annual precipitation is not significantly related to elevation (tab. 1). the site actually represents a snowfall extreme in the entire alps, snow accumulation being concentrated in late winter and spring, and net snow accumulation summing up to 7 m at 1950 m asl (1964-1973 period, belloni & pelfini, 1990). the glacier equilibrium line elevation under current climate conditions exceeds the mountain peaks; it was about 2600 m in 1994 ad (caccianiga et al., 1994). the vegetation of the area provides a representative example of elevational ecological gradient in an oceanic climatic regime common in the eastern and northern alps, heavily affected by pastoralism in the last 4 ka, which however, did not alter the fundamental traits of the timberline structure (furlanetto et al., 2018, fig. 2). 3. methods: development of an elevational transect and sampling strategy a transect composed by 16 sampling sites was developed (fig. 1). the precise location and descriptive information of the sampling sites are listed in tab. 1. at the center of each site, a pollen trap was located on the ground fixed to iron bars, in order to avoid snow runoff at the soil level. three moss samples were collected within fig. 1 sampling sites for modern pollen assemblages and vegetation data stretching along a typical mid-latitude ecoclimatic elevational gradient under oceanic cold temperate climate in the upper brembana valley. for this study, only the upper elevational reach, spanning a lapse of 1200 m from 1200 to 2400 m asl, was considered. 119 ecological climatology along an elevational transect a circular area of 1.8 m radius (fig. 3, zone a) and mixed together (cañellas-boltà et al., 2009), while concentric circles of 1.8 and 10 m-radius were considered for vegetation surveys following the braun-blanquet method (fig. 3, zone a and b). furthermore, main arboreal species were listed and a cover estimation was carried out within a 100 m radius circle with the help of orthoimages (fig. 3, zone c). 3.1. canonical correspondence analysis (cca) ordination techniques are considered appropriate for assessing and displaying the relationship between pollen percentages recorded in modern pollen assemblages, vegetation data, elevation and climatic parameters. these statistical analyses have been frequently used to detect structures or patterns within pollen and vegetation data. they provide an efficient lowdimensional representation of complex multivariate data and serve to indicate their major gradients and the relative contribution of each taxon to each of these gradients. all the plants present an ecological optimum and tolerance to most environmental gradients, justifying the use of a biological unimodal response model (ter braak, 1987, ter braak and prentice, 1988). in this work, canonical correspondence analysis (cca), the constrained form of correspondence analysis (ca) (ter braak 1986) was used as direct gradient analysis to highlight the relationships between pollen, vegetation, elevation and climate. several cca ordinations have been performed using elevation, july temperature, janutab. 1 site metadata for the upper brembana valley elevational transect. ary temperature and annual precipitation as the sole constraining variable to assess their importance on the variance of pollen and vegetation (1.8 m and 10 m radius) assemblages (tab. 2). prior to the cca analysis, pollen percentages were square-root transformed, for variance stabilization (prentice, 1980) and taxa with percentages below 2%, were removed. the significance of all cca were tested with anova (p <0.05, after 999 unrestricted permutations). 3.2. estimation of climate normals along the elevational transect site-specific instrumental temperature and precipitation series, covering the 1951-2015 period, were reconstructed for each sampling site by means of the anomaly method (new et al., 2000; mitchell & jones, 2005) as described in brunetti et al. (2012), to obtain a climate reconstruction as much representative of the specific locations as possible, thanks to the huge amount of meteorological observations available for italy and surrounding areas. the closest meteorological station (foppolo, 1520 m asl) is situated ca 4 km far from site l 1 and ca 9.5 km far from site l 24. the interpolation procedure consists in the independent reconstruction of the climatological normals over a given reference period (i.e. climatologies) and the departures from them (i.e. the anomalies): the former, characterized by remarkable spatial gradients, were reconstructed by evaluating the local dependence of the meteorological variable on elevation (brunetti et al., 2014; crespi et al., 2018), and a high spatial density network of stations (even if with a limited temporal coverage) was used; anomalies are linked to climate variability and are characterized by a higher spatial coherence, therefore, a more simple interpolation technique and a low spatial density of stations are enough, but long temporal coverage and accurate homogenization (i.e. the procedure that removes the non-climatic signals introduced by stations and instruments relocation, changes in measurement practices and so on) are mandatory. finally, climatologies and anomalies were superimposed to get temperature and precipitation monthly series in absolute values for each sampling site. information about the techniques and their accuracy are provided in brunetti et al. (2012, 2014) and crespi et al. (2018). from these monthly series, mean temperature of the warmest month (july), coldest month (january) and the total annual precipitation over the 1981-2010 period were calculated for the sampled sites (tab. 1). 120 fig. 2 picture showing the structure of the oceanic-type timberline ecotone at the headwall of the brembana valley in the outer italian alps. elevation values refer to current limits in the studied area (in brackets the maximum elevations recorded in the orobie alps). the natural extent of forest vegetation is the result of long-term effects of pastoralism, wildfire, and climate changes. according to paleobotanical data, the current timberline structure still reflects the dominance of pristine dwarf forests which become established in the second half of the holocene (furlanetto et al., 2018). furlanetto g. et al. 121 tab. 2 proportions of variance explained by each explanatory variable as the sole constrained and permutational-repeated measures analysis (anova) obtained for modern pollen assemblages (pollen traps and moss samples) and vegetation data (surveys at 1.8 m and 10 m radius circles). fig. 3 site sampling method scheme used for vegetation survey. ecological climatology along an elevational transect 3.3. vegetation data: surveying strategy (braunblanquet system) at each sampling site, vegetation surveys were carried out using the braun-blanquet abundance/ dominance scale (braun-blanquet, 1979) within circular areas of 1.8 m radius (ca 10 m2) and 10 m radius (ca 314 m2). in this system, a semi-quantitative abundancedominance index is used to estimate the plant cover for each species, according to the following scale: 5 (80100%), 4 (60-80%), 3 (40-60%), 2 (20-40%), 1 (1-20%), + (scarce), r (rare). finally, within the circular areas of 100 m radius was estimated the cover of the main species. this methodology was focused on producing good estimates of the abundance of the major taxa (the producers of the pollen types which are the major components of current and past pollen deposition in the study area) rather than recording every species present. compared to plant species identification, pollen usually presents lower taxonomic resolution, in most cases only reaching genus or family level. to facilitate comparative data analyses plant species recorded in the vegetation surveys were grouped into higher taxonomic levels to match their corresponding pollen types and presented as percentages. 3.4. pollen analysis modern pollen assemblages at the center of each site, a pollen trap was located (fig. 3, zone a). the trap has a circular opening on top (4.5 cm in diameter), through which the airborne pollen can freely enter. glycerine and thymol were placed in the trap to inhibit the growth of mould and the opening was covered by a 2 mm mesh fixed to the trap with duct tape. pollen monitoring data represents the period 2016-2017. in each site, three moss polsters were also collected within a circular area of 1.8 m radius (ca 10 m2) and mixed into one sample. mosses were sampled down to, but not including, the mineral soil. samples were processed following standard methods at the laboratory of palynology and palaeoecology of cnr-idpa in milan, after adding lycopodium tablets for pollen and pollen-slide microcharcoal concentration estimations (stockmarr, 1971). a minimum count of 600 pollen grains was obtained at each sampling site, aquatics, spores and non-pollen palynomorphs were excluded from the pollen sum. identification was carried out at x400, x630 and x1000 magnifications under a leica dm -lb light microscope. pollen identification followed moore et al. (1991), punt & blackmore (1976-2009), reille (1992-1998), beug (2004) and the cnr pollen reference collection. microbiological particles were named after van geel et al. (1981), van geel (1978) and van geel & aptroot (2006) and expressed as percentages out of the pollen sum. pollen-slide microcharcoal particles were counted under a light microscope at 400x. black, completely opaque and angular fragments (clark, 1988) were identified as charcoal and grouped in two size classes (10-50 μm and 50-250 μm length). 3.5. pollen accumulation rates (par) pollen monitoring using annual pollen traps helps to quantify and calibrate pollen deposition with presentday vegetation and meteorological conditions, as well as providing insights into local pollen dispersal and sedimentation mechanisms (hicks, 2001). pollen accumulation rates (par) measurements can also be used as a modern reference to estimate past plant population densities buffering the study site (hicks, 2001; tinner & theurillat, 2003; badino et al., 2018). modern par values were calculated for alnus viridis, one of the main timberline ecotone shrub species in the outer oceanic districts of central alps. 4. results 4.1. canonical correspondence analysis (cca) this study aims at emphasizing pollen/vegetation/ climate relationships at a local scale. indeed, although extra-local and regional non-arboreal pollen is present in the modern pollen spectra, herbaceous pollen assemblages appear to reflect predominantly local vegetation rather than wider landscape units, as also demonstrated by caseldine & pardoe (1994), hjelle (1999) and pardoe (2001). the variances explained by elevation and each climate parameter (tjuly, tjan and pann), calculated with cca ordinations with unique constrained, are presented in tab. 2. the canonical correspondence analysis (cca) of the vegetation data and pollen assemblages suggests that the variation in vegetation and pollen is strongly correlated to the elevational gradient (tab. 2). in both vegetation data and pollen assemblages elevation explains more variance than the climate parameters, although alike percentages of variance are explained by tjuly and tjan. for the pollen traps the variance explained by elevation is 17.0%, 16.6% by tjuly, 16.9% by tjan and 12.7% by pann. for the moss samples the variance explained by elevation is 14.6%, 14.4% by tjuly, 14.5% by tjan and 10.9% by pann. pann is not significant in the moss samples assemblage (p > 0.05, after 999 unrestricted permutations). for the vegetation 1.8 m the variance explained by elevation is 12.6%, 12.3% by tjuly, 12.4% by tjan and 12.0% by pann. finally for the vegetation 10 m the variance explained by elevation is 15.6%, 15.4% by tjuly, 15.4% by tjan and 14.0% by pann. 4.2. modern pollen assemblages and their relationship to vegetation the pollen spectra of 18 pollen traps and 16 moss samples are presented in synthetic percentage diagrams, which include selected pollen types and total microcharcoal concentrations (figs. 4-5). plant species recorded in the 10 m vegetation surveys, grouped into higher taxonomic levels to match their corresponding pollen types are presented in a synthetic percentage diagram (fig. 6). in the site l 1 located at 1244 m asl (fig. 6) the main vegetation species are corylus avellana, picea abies and larix decidua among trees and shrubs; festuca sp. and laserpitium halleri and laserpitium krapfii among herbs. in the pollen traps the dominant taxa are picea, corylus and poaceae (fig. 4, tl1-tl2) while corylus, ostrya type, fraxinus excelsior type, pinus sylvestris/mugo, and larix represent the main taxa in the moss samples (fig. 5, ml1-ml2). pollen taxa from broad-leaved tree (e.g. castanea, and ostrya type) occur in high proportions (figs. 4a-5a). alnus viridis reach 122 furlanetto g. et al. dra (10%), while the site l 10 shows the 50% of agrostis sp., 30% of festuca scabriculmis and 30% cover of sanguisorba dodecandra. the sites l 2 and l 5 are respectively located in mowed leans surrounded by thickets of broad-leaved trees and in a pasture at the border of a mixed coniferous forest. in the 10 m vegetation survey (l 2) pimpinella major has the 30% of cover, followed by 10% of alchemilla vulgaris, geranium sylvaticum, heraes high cover percentages (10-30%) in sites l 3 and l 4 located next to streams and also in the site l 10 (30%) located in an avalanche corridor/stream (fig. 6), this abundance in alnus viridis is also presented in modern pollen assemblages (figs. 4a-5a). sites l 3 and l 4 show also high cover percentages of festuca scabriculmis (50-70%), galium lucidum (30%), pimpinella major (10%) and the endemic tall herb sanguisorba dodecan 123 fig. 4 percent diagram obtained from pollen traps from the upper brembana valley elevational transect showing selected pollen taxa and main vegetation zones. ecological climatology along an elevational transect cleum sphonodylium, rumex scutatus, trifolium pretense and polygonum bistorta; in the site l 5 laburnum alpinum has 50% of cover, picea abies 20%, larix decidua 10%, among herbs festuca pratensis has 20% of cover. the site l 7, a grassland along an avalanche corridor presents 10% of picea abies and larix decidua (fig 6a); among herbs 30% of calamagrostis sp., rhinanthus sp. and sanguisorba dodecandra. this latter herb is well represented in the pollen trap (trap tl7, fig. 4b) reaching 18%. the sites l 12-l 18 are located in the upper subalpine belt with ericaceae moorlands (erica carnea, vaccinium gaultherioides, vaccinium myrtillus, rhododendron ferrugineum and loiseleuria 124 procumbens) and alnus viridis thickets with larix decidua individuals; larch treeline is located at 2220 m. juniperus nana shows high cover percentages in the sites l 12 and l 15, that are little reflected in the pollen percentages. in the sites (l 12-l 18) the pollen trap and moss sample assemblages are dominated by alnus viridis, pinus sylvestris/mugo, and poaceae, the ericaceae moorland is well represented by vaccinium while erica, rhododendron and loiseleuria show sporadic occurrences (figs. 4a-5a). above 2100 m asl the wind-driven uphill transport of pollen from the lower belts shows increased percentages of pinus sylvestis/mugo, betula, corylus, ostrya type, fagus, and carpinus betulus in fig. 5 percent diagram obtained from moss samples from the upper brembana valley elevational transect showing selected pollen taxa and main vegetation zones. furlanetto g. et al. the moss samples and increased percentages of picea, betula, corylus and castanea in the pollen traps. in sites (l 21-l 24) the 10 m vegetation is dominated by festuca scabriculmis, festuca quadriflora, carex sempervirens (l 21); salix herbacea, chrysanthemum alpinum and potentilla aurea (l22); cirsium spinosissimum, poa alpina, rumex alpestris and potentilla aurea (l 24). the site l 24 (2390 m asl) is located in an extensive pasture, reflected in modern pollen assemblages by high percentages of poaceae and of dung spores (sordariaceae undiff., sporormiella-like spores, and podospora). 4.3. pollen accumulation rate (par) alnus viridis, the main woody species forming extensive dwarf forests in the upper brembana valley timberline ecotone (fig. 2), shows a specific elevational par arrangement under modern climate conditions (tab. 3). the highest par values in the local elevational transect are observed in sites l3 and l10 (1420 and 1940 m asl, respectively) in river corridors and waterfalls with mountain alder scrub. here par values range between 2400 and 3100 pollen grains cm-2 yr-1 (tab. 3, traps tl3 and tl10). on the other hand, pollen traps at subalpine elevation (tab. 3, traps tl16, tl18; respectively 2100 and 2180 m asl), located at the border of mountain alder scrub with continuous understory of ericaceae, display par values of about 700 pollen grains cm-2 yr-1. 125 fig. 6 percent diagram of plant cover of selected plant species from the upper brembana valley elevational transect recorded in the 10 m vegetation surveys. species were grouped into higher taxonomic levels to match their corresponding pollen types. in order to allow comparison with pollen assemblages the same taxa presented in the pollen diagrams were selected. ecological climatology along an elevational transect 5. discussion: pollen-vegetation-elevation and climate relationships our data are in agreement with previous studies which identified elevation as the main gradient controlling modern pollen assemblages and vegetation distribution across mountain regions (bonnefille et al., 1993; vincens et al., 1997; weng et al., 2004; court-picon 2005, 2006; rull, 2006; cañellas-boltà et al., 2009). the canonical correspondence analysis (cca) showed that elevation explains the major percentage of variance in both vegetation data and pollen assemblages (tab. 2); although alike percentages of variance are explained by the temperature climate parameters (tjuly and tjan). all the temperature parameters vary accordingly with elevation due to a stable lapse rate. july lapse rate ranges from 0.56 °c/100 m in the mountain belt to 0.77 °c/100 m above the open forest limit (furlanetto et al., 2019). a lower percentage of variance is explained by annual precipitation (tab. 2), that is not significantly related to elevation as temperature but is instead strongly controlled by regional climate (fig. 2b in furlanetto et al., 2018). in spite of the uphill pollen transport, pollenelevation and climate relationships are strong since pollen is directly correlated to elevation and climate. pollen and vegetation data are independent. 5.1. uphill pollen transport the uphill transport of pollen by wind to subalpine and alpine zones was first recorded in the european alps (markgraf, 1980; david, 1997; frei, 1997; brugiapaglia et al., 1998; ortu, 2002). markgraf (1980) showed that, in a steep valley-slope system of alpine type, the proportion of pollen dispersal from local uphill winds in daytime decreases with increasing elevation in favor of regional (medium-distance) dispersal. this highelevation dispersal component relies significantly on pollen washout by rain, which cleans the atmosphere of suspended pollen (markgraf, 1980). pollen belts tend to be wider and with less defined boundaries than vegetation; this is likely due to the homogenizing effect of wind dispersal, especially from lower to upper elevational levels. thus, if it is possible to identify the major vegetation types by means of their modern pollen deposition, it becomes more difficult to identify specific thresholds (e.g. treeline). the over-representation of pinus in the pollen assemblages is well documented by numerous authors (e.g. broström et al. 1998; brugiapaglia et al. 1998; ortu et al. 2005, 2006; courtpicon et al., 2005, 2006, cañellas-boltà et al., 2009). the strong pollen signal of pinus sylvestris/mugo is recorded in the moss samples above the treeline (fig. 5a, ml17-24), while pinus mugo is not recorded in the vegetation data (fig. 6). in the study area, isolated stands of mountain dwarf pine (pinus mugo) form part of the timberline structure at 1800-2000 m asl at dry edaphic sites. a dark coniferous forest (picea abies, abies alba, larix decidua) occurs only on shaded slopes, therefore picea abies appears in the 10 m vegetation surveys only in sites l 1, l 5 and l 7 (fig. 6a). in the pollen traps and moss samples picea shows a marked uphill transport to subalpine and alpine zones in the pollen traps (fig. 4a). deciduous trees of the mountain belt (e.g. corylus, betula, ostrya, castanea) also show uphill wind transport. castanea uphill transport is marked in pollen traps (figs. 4a) while corylus and ostrya show high percentages in the moss samples ml16-21 between 2106 and 2341 m asl (fig. 5a). the influence of upslope wind dispersal of mediumto long-distance transported pollen types (e.g. castanea and ostrya type) have to be taken into account and interpreted with caution in the fossil records. 5.2. potential indicator taxa of subalpine/alpine belts extensive mountain alder shrublands develop in the subalpine elevational belt under oceanic, cool temperate climates, that hinder cembran pine fitness. edaphic geodiversity allows mountain alder to compete with dwarf pine (pinus mugo), the latter also tolerating oceanic climates, but escaping edaphic wetness. alnus viridis vegetation needs a continuous water supply during the growing season, enhanced by high annual snowfall rate and good soil water balance (richard, 1968, 1969; mauri and caudullo, 2016). in alpine oceanic 126 tab. 3 modern alnus viridis pollen accumulation rate values based on pollen monitoring data in the upper brembana valley, representing the period 2016-2017. the location of the sites is shown in fig. 1. furlanetto g. et al. climates, its ecological range expands downstream especially along avalanche corridors but also on northern slopes, due to a general increase in soil moisture, and thus species optima are shifted towards lower elevations (e.g. fig. 2); for this reason, it shows lower elevation optima compared to continental inner valleys (furlanetto et al., 2019). alnus viridis par measurements from pollen traps at subalpine elevation (21002180 m asl), located at the border of mountain alder dwarf forest can be used as a modern reference to estimate past plant population densities (furlanetto et al., 2018). caution is due because the pattern of decreasing pollen production with elevation (furlanetto et al., 2018) also affects par values. pollen productivity estimates (ppes) were not calculated from modern pollen samples because regional (104-105 km2—reveals model) and local (<1 km2 up to 5 km2—love model) vegetation reconstruction methods were not applied to the fossil record (furlanetto et al., 2018) as the application of love model (fossil pollen from small study sites) was not possible. the love model estimates the vegetation composition within the source area subtracting the background pollen from the pollen signal. as pollen records from large sites closed to the study area for regional vegetation composition were lacking this model was not applied to the fossil record. ericaceae is considered an excellent indicator of the montane/subalpine belts (cañellas-boltà et al., 2009). in our study, the identification of pollen types within this family allows to highlight different elevational patterns of pollen and relative parent taxa. vaccinium, rhododendron and loiseleuria show a consistent pollen -vegetation elevational pattern restricted to the timberline belt between 2000 and 2300 m asl (fig. 7). whereas erica pollen type shows a wider distribution especially in pollen traps from 1422 to 2345 m asl (fig. 4a) even though it is recovered in the 10 m vegetation surveys between 1550 and 2000 m asl (fig. 6). also juniperus shows an elevational pattern in both vegetation and pollen traps with major abundance at the lower limit of the open forest, ca. 2000 m (fig. 7). 6. conclusions relationships between climate, ecosystems and forcing factors may be effectively understood by setting up training sets along ecogradients, and using proxies that allow to synthesize spatial variables such as vegetation (pollen proportions) and terrestrial biomass (pollen accumulation rates). the development of an elevational transect in the upper brembana valley (central italian alps) represents a first step for analyzing ecological 127 fig. 7 histograms showing the elevational distribution of plant cover % (10 m vegetation surveys) and of pollen % (moss samples and pollen traps) for potential indicator taxa of subalpine/alpine belts. ecological climatology along an elevational transect gradients with multivariate analysis of modern pollen assemblages as synthetic proxies addressing relationships between modern vegetation, elevation and climate. the results of cca analysis demonstrated a general good agreement with previous studies, which identified elevation as the main gradient in the variation of modern pollen and vegetation assemblages in mountain areas); although alike percentages of variance are explained by the temperature climate parameters (tjuly and tjan). alnus viridis, the main woody species forming the dwarf forests in the timberline ecotone, shows a specific elevational par arrangement under modern climate conditions. the highest par values are observed in sites from river corridors and waterfalls with mountain alder scrub. the uphill transport of pollen by wind to subalpine and alpine zones implies wider pollen belts with less defined boundaries than vegetation. this is mainly due to the increase in extra-local transport of strong pollen producers (e.g. pinus sylvestris/mugo, picea, castanea, corylus and ostrya) and lead to some homogenization of pollen assemblages. to overcome these limitations, potential indicator pollen taxa of alpine/subalpine belts (vaccinium, rhododendron, loiseleuria) documented in this study and par of timberline species (e.g. alnus viridis) could be useful. thus, if it is possible to identify the major vegetation types and ecotones by means of their modern pollen deposition (e.g. timberline ecotone), other limits, poorly marked by changes in pollen dispersal (e.g. treeline) are not resolved by pollen proxies alone. acknowledgments this paper is the result of giulia furlanetto’s phd research project sponsored by the milano-bicocca university, dept. of earth and environmental sciences, with the co-tutoring and support of the cnr-idpa. this paper is a contribution to the cnr-idpa research project dta.ad001.112 "quaternary environmental history, ecological changes and mutual interactions with human societies". suggestions provided by séverine fauquette, donatella magri and elda russo-ermolli improved the quality of the manuscript. special thanks go to migliorini enzo, manager of the rifugio longo and to cai for logistic support; to renata perego and massimo domenico novellino for support during the field work. this research was supported by a grant from parco regionale delle orobie bergamasche (delib. 12/2017). references badino f., ravazzi c., vallè f., pini r., aceti e., brunetti m., champvillair e., maggi v., maspero f., perego r., orombelli g. (2018) 8800 years of highaltitude vegetation and climate history at the rutor glacier forefield, italian alps. evidence of middle holocene timberline rise and glacier contraction. quaternary science reviews, 185, 41-68. belloni s., pelfini m. (1990) la nevosità in lombardia nel periodo 1964-1973. natura bresciana, 25, 63108. beug h.j. (2004) -. leitfaden der pollenbestimmung für mitteleuropa und angrenzende gebiete. verlag dr. friedrich pfeil, münchen, germany. bonan g. (2016). ecological climatology. concepts and applications. cambridge university press. bonnefille r., buchet g., friis i.b., kelbessa e., mohammed m.u. (1993) modern pollen rain on an altitudinal range of forests and woodlands in south west ethiopia. opera botanica, 121, 71-84. braun-blanquet j. (1979) fitosociologica. blume, madrid. broström a., gaillard m.j., ihse m., odgaard b. (1998) pollen-landscape relationships in modern analogues of ancient cultural landscapes in southern sweden a first step towards quantification of vegetation openness in the past. vegetation history and archaeobotany, 7(4), 189-201. brugiapaglia e., de beaulieu j.l., guiot j., reille m. (1998) transect de pluie pollinique et étagement de la végétation dans le massif du taillefer (isère, france) géographie physique et quaternaire, 52 (2), 209-218. brunetti m., lentini g., maugeri m., nanni t., simolo c., spinoni j. (2012) projecting north eastern italy temperature and precipitation secular records onto a high-resolution grid. physics and chemistry of the earth, 40-41, 9-22. brunetti m., maugeri m., nanni t., simolo c., spinoni j. (2014) high-resolution temperature climatology for italy: interpolation method intercomparison. international journal of climatology, 34(4), 12781296. caccianiga m., ravazzi c., zubiani p. (1994) storia del ghiacciaio del trobio (alpi orobie, bergamo) e colonizzazione della vegetazione nelle aree liberate dopo la piccola età glaciale. natura bresciana, 29, 65-96. cañellas-boltà n., rull v., vigo j., mercadé a. (2009) modern pollen-vegetation relationships along an altitudinal transect in the central pyrenees (southwestern europe). the holocene, 19(8), 1185 -1200. caseldine c., pardoe h. (1994) surface pollen studies from alpine/sub-alpine southern norway: applications to holocene data. review of palaeobotany and palynology, 82(1), 1-15. clark j.s. (1988) particle motion and the theory of charcoal analysis: source area, transport, deposition, and sampling. quaternary research, 30(1), 67-80. court-picon m., buttler a., de beaulieu j.l. (2005) modern pollen-vegetation relationships in the champsaur valley (french alps) and their potential in the interpretation of fossil pollen records of past cultural landscapes. review of palaeobotany and palynology, 135(1), 13-39. court-picon m., buttler a., de beaulieu j.l. (2006) modern pollen/vegetation/land-use relationships in mountain environments: an example from the champsaur valley (french alps). vegetation history and archaeobotany, 15(3), 151-168. crespi a., brunetti m., lentini g., maugeri m. (2018) 1961-1990 high-resolution monthly precipitation 128 furlanetto g. et al. climatologies for italy. international journal of climatology, 38, 878-895. david f. (1997) holocene tree limit history in the northern french alps stomata and pollen evidence. review of paleobotany and palynology, 97, 227237. frei t. (1997) pollen distribution at high elevation in switzerland: evidence for medium range transport. grana, 36, 34-38. furlanetto g., ravazzi c., pini r., vallè f., brunetti m., comolli r., novellino m.d., garozzo l., maggi v. (2018) holocene vegetation history and quantitative climate reconstructions in a high-elevation oceanic district of the italian alps. evidence for a middle to late holocene precipitation increase. quaternary science reviews, 200, 212-236. furlanetto g., ravazzi c., badino f., brunetti m., champvillair e., maggi v. (2019) elevational transects of modern pollen samples site specific temperatures as a tool for paleoclimate reconstructions in the alps. the holocene, 29(2), 271286. hicks s. (2001) the use of annual arboreal pollen deposition values for delimiting tree-lines in the landscape and exploring models of pollen dispersal. review of palaeobotany and palynology, 117 (1-3), 1-29. hjelle k.l. (1999) modern pollen assemblages from mown and grazed vegetation types in western norway. review of palaeobotany and palynology, 107(1), 55-81. lisitsyna o.v., hicks s. (2014) estimation of pollen deposition time-span in moss polsters with the aid of annual pollen accumulation values from pollen traps. grana, 53(3), 232-248. markgraf v. (1980) pollen dispersal in a mountain area. grana, 19, 127-146. mauri a., caudullo g. (2016) alnus viridis in europe: distribution, habitat, usage and threats. in: sanmiguel-ayanz j, de rigo d, caudullo g, houston durrant t, mauri a (eds) european atlas of forest tree species. publication office of the european union, luxembourg, p. 68. mitchell t.d., jones p.d. (2005) an improved method of constructing a database of monthly climate observations and associated high-resolution grids. international journal of climatology, 25(6), 693712. moore p.d., webb j.a., collinson m.e. (1991) pollen analysis. blackwell scientific publications, oxford. new m., hulme m., jones p. (2000) representing twentieth-century space-time climate variability. part ii: development of 1901-96 monthly grids of terrestrial surface climate. journal of climate, 13, 2217-2238. ortu e. (2002) reconstruction sur base pollinique de la dynamique de la végétation tardiglaciaire et holocène dans les alpes maritimes italiennes. phd thesis, university d'aix-marseille, iii, f. ortu e., david f., caramiello r. (2005) effet des paramètres locaux sur le développement de la végétation dans le vallon de st. anna di vinadio (alpes maritimes; italie) écoscience, 12, 122-135. ortu e., brewer s., peyron o. (2006) pollen-inferred palaeoclimate reconstructions in mountain areas: problems and perspectives. journal of quaternary science, 21(6), 615-627. ortu e., klotz s., brugiapaglia e., caramiello r., siniscalco c. (2010) elevation-induced variations of pollen assemblages in the north-western alps: an analysis of their value as temperature indicators. comptes rendus biologies, 333(11), 825-835. pardoe h.s. (2001) the representation of taxa in surface pollen spectra on alpine and sub-alpine glacier forelands in southern norway. review of palaeobotany and palynology, 117(1), 63-78. pardoe h.s., giesecke t., van der knaap w.o., svitavská-svobodová h., kvavadze e.v., panajiotidis s., gerasimidis a., pidek i.a., zimny m., świętamusznicka j., latałowa m., noryśkiewicz a.m., bozilova e., tonkov s., filipova-marinova m.v., van leeuwen j.f.n., kalniņa l. (2010) comparing pollen spectra from modified tauber traps and moss samples: examples from a selection of woodlands across europe. vegetation history and archaeobotany, 19, 271-283. peel m.c., finlayson b.l., mcmahon t.a. (2007) updated world map of the köppen-geiger climate classification. hydrology and earth system sciences, 11(5), 1633-1644. prentice i.c. (1980) multidimensional scaling as a research tool in quaternary palynology: a review of theory and methods. review of palaeobotany and palynology, 31, 71-104. punt w., blackmore s. (eds) (1976-2009) the northwest european pollen flora. vol. i-ix. elsevier publishing company. räsänen s., hicks s., odgaard b.v. (2004) pollen deposition in mosses and in a modified ‘tauber trap’ from hailuoto, finland: what exactly do the mosses record? review of palaeobotany and palynology, 129, 103-116. reille m. (1992-1998) pollen et spores d’europe et d’afrique du nord. laboratoire de botanique historique et palynologie, marseille. richard l. (1968) écologie de l'aune vert (alnus viridis): facteurs climatiques et édaphiques. documents pour la carte de végétation des alpes, 6, 107-158. richard l. (1969) une interprétation éco-physiologique de la répartition de l'aune vert (alnus viridis). documents pour la carte de végétation des alpes, 7, 7-23. rull v. (2006) a high mountain pollen-altitude calibration set for palaeoclimatic use in the tropical andes. the holocene, 16, 105-107. stockmarr j. (1971) tablets with spores used in absolute pollen analysis. pollen et spores, 13, 615-621. ter braak c.j. (1986) canonical correspondence analysis: a new eigenvector technique for multivariate direct gradient analysis. ecology, 67(5), 11671179. ter braak c.j. (1987) the analysis of vegetationenvironment relationships by canonical correspondence analysis, in: theory and models in vegetation science. springer netherlands, pp. 69 129 ecological climatology along an elevational transect 77. ter braak c.j., prentice i.c. (1988) a theory of gradient analysis. advances in ecological research, 18, 271-317. tinner w., theurillat j.p. (2003) uppermost limit, extent, and fluctuations of the timberline and treeline ecocline in the swiss central alps during the past 11,500 years. arctic, antarctic, and alpine research, 35(2), 158-169. van geel b. (1978) a palaeoecological study of holocene peat bog sections in germany and the netherlands, based on the analysis of pollen, spores and macroand microremains of fungi, algae, cormophytes and animals. review of palaeobotany and palynology, 25, 1-120. van geel b., bohncke s.j.p., dee h. (1981) a palaeoecological study of an upper late glacial and holocene sequence from 'de borchert', the netherlands. review of palaeobotany and palynology, 31, 367-449. van geel b., aptroot a. (2006) fossil ascomycetes in quaternary deposits. nova hedwigia 82, 313-329. vincens a., ssemmanda i., roux m., jolly d. (1997) study of the modern pollen rain in western uganda with a numerical approach. review of palaeobotany and palynology, 96(1), 145-168. weng c., bush m.b., silman m.r. (2004) an analysis of modern pollen rain on an elevational gradient in southern peru. journal of tropical ecology, 20 (01), 113-124. 130 furlanetto g. et al. ms. received: february 22, 2019 final text received: may 10, 2019 microsoft word 03_benvenuti_lm03.doc available online http:/amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 26 (1), 2013, 31-39 the uppermost middle pleistocene-holocene alluvial deposits of the upper tiber basin (northern apennines, central italy): chronologic constraints from archaeological data marco benvenuti1, adriana moroni2, francesca tangocci1, 1 dipartimento di scienze della terra, università di firenze, italy 2 unità di ricerca di ecologia preistorica dipartimento di scienze fisiche, della terra e dell’ambiente università di siena, italy corresponding author : marco benvenuti <marcob@geo.unifi.it> abstract: the paper reports the results of a geomorphologic and stratigraphic study of the nw portion of the upper tiber basin (central italy), and focuses on the terraced alluvial deposits which are grouped into late middle-upper pleistocene (mup) and holocene (hol) units. the drainage development in the basin was deeply influenced by an active tectonic setting characterized by orthogonal fault systems, which forced river deviations and attracted alluvial deposition in the subsiding portions of the basin. the occupation of this intermountain territory by ancient human communities is recorded by late prehistoric-protohistoric archaeological findings collected within or on the surfaces delimiting these units. this archaeological dataset allowed an indicative dating of the major stages of the fluvial evolution between the end of the middle pleistocene and the late holocene. the chronological constraint indicates that the morphostratigraphic events recorded in the mup and hol units, have reasonably occurred within the two last glacial-interglacial cycles. rapid climate changes, affecting the surface hydrology and the sediment supply to the river systems, and the active tectonic setting, thus, may account for the gaps in the local archaeological record, including most of the late paleolithic, the mesolithic and the early neolithic. late pleistocene and the early holocene stages of relevant alluvial deposition in a subsiding basin may have caused the burial of the missing cultural stages or may have prevented the human occupation of hydraulically unsafe valley floors. keywords: alluvial terraced deposits, intermontane basin, archaeology, middle pleistocene-holocene, central italy. 1. introduction despite several techniques are suitable for the geochronological calibration of the quaternary successions (walker, 2005), a major problem in the study of terraced alluvial deposits is frequently represented by their dating. nevertheless, temporary or stable human settlements have occupied alluvial plains, especially during the late quaternary. this is testified by archaeological remains spanning the late prehistorical-historical cultural stages. the geoarchaeology of alluvial plains (brown, 1997; woodward & huckleberry, 2011), thus, may provide suitable tools for analysing the dynamics of these environments induced by concurrent natural and anthropic processes. in the northern apennines (central italy) terraced fluvial deposits occurring in several intermountain basins (fig. 1a), are ascribed to the late quaternary on the basis of weak morpho-stratigraphic constraints, often lacking absolute dating. the occurrence of archaeological remains on the surfaces and within the alluvial deposits of this region, attests to a human occupation dating back to the prehistory. the dating of different cultural stages that developed in central italy may be quite precise for the late prehistory (late pleistocene-early holocene)protohistory (mid-late holocene) interval, becoming extremely accurate in historic periods. this feature makes the archaeologic data a suitable tool for an indicative to accurate chronologic constraint of late quaternary landforms and deposits occurring in this region. in this paper we present the spatial and stratigraphic distribution of terraced alluvial deposits in the intermountain upper tiber basin (ne tuscany, central italy) referred to the latest middle pleistocene-holocene on the base of the distribution and dating of archaeological materials collected in the last decades. 2. regional setting the study area is located in the upper reach of the tiber river, barred by the montedoglio dam and including the tributaries singerna, sovara, tignana and afra creeks. this is a portion of the upper tiber river basin (utb, figs. 1, 2), a nw-se trending intermountain depression about 21 km long and 10 km wide, flanked by steep hills composed of miocene turbiditic sandstones (tuscan and umbro-marchean units respectively) to the nne and ssw and jurassic-eocene ophiolithes, limestone and marls (ligurid units) to the nnw. the basin is bounded by the alto tiberina fault along the sw shoulder (atf, figs. 1b, 2) and by the antithetic sansepolcro fault on the opposite side (ssf in fig. 2; barchi & ciaccio, 2004). the nw-se elongated anghiari-citerna hills are delimited toward the tiber plain by the atfsynthetic anghiari fault and cross-cut by ne-sw trending faults (fig. 2). a portion of a basin fill about 1,000 meters thick (sani et al., 2009), is exposed on the flanks of these hills (benvenuti, 1989; cattuto et al., 1995; pialli & plesi, 2009), consisting of 150 m thick lower-middle pleistocene alluvial gravels, sands and subordinated benvenuti m. et al. 32 muds subdivided in this study into four main units (fig. 2; tab. 1). the older, monterchi-citerna-fighille unit (mcf, fig. 2), includes final lower pleistocene floodplain-palustrine sands and muds (mcf1) (ciangherotti & esu, 2000; argenti, 2003-2004) erosively overlain by early middle pleistocene fluvial arenaceous-calcareous gravels, sands and muds (mcf2) (benvenuti, 1989). the mcf unit is tilted against the atf (cross section in fig. 2; sani et al., 2009) and unconformably overlain by the anghiari unit (ang), made of middle pleistocene fluvial calcareous gravels (ang1) unconformably overlain by deeply weathered fine conglomerate and sand (ang2) (van waveren, 1986). the tiber river plain is characterized by alluvial and colluvial deposits (mup and hol units, fig. 2) that are described and discussed in more detail in section 4. 3. archaeological records since prehistory and protohistory the upper tiber valley has represented a strategic connection route across the northern apennines divide as documented by extensive archaeological surveys (moroni lanfredini & benvenuti, 2010; fig. 2). the middle palaeolithic is the earliest period recorded. this is represented by stone tools collected southwest of anghiari on the surfaces of the ang2 unit and in the palaeosovara terraced deposits (mup2 at castel di sorci and nearby sites, site 1 in fig. 2; cocchi et al., 1978; borgia & moroni lanfredini, 2004, moroni et al., 2011) attesting to the presence of neanderthal groups for seasonal hunting and gathering. the lithic assemblages are characterized by levallois and, subordinately, discoid production systems and include mainly side scrapers, points, denticulates (fig. 3a-c) and rare handaxes. the early upper paleolithic is documented on the nw slopes of the basin by an aurignacian lithic industry, very rich in burins des vachons (fig. 3d-e), recovered near caprese michelangelo (fig. 1b) (moroni lanfredini & ronchitelli, 2001), which dates back around 30 ka ago (arrighi et al., 2006). the floodplain occupation is recorded from the final upper paleolithic in the consuma 2 site (site 2 in fig. 2; moroni, 1990), presently flooded by the montedoglio lake, by a final epigravettian lithic assemblage dating back to around 12 ka ago, characterized by microlithic backed tools. evidence of the human presence on the valley floor during the early holocene is fragmentary with a missing mesolithic stage and only few early neolithic findings discovered in the tiber plain (consuma, site 2 in fig. 2). the neolithic to eneolithic (copper age) transition is recorded near the tiber river (consuma 1 and moresco; sites 2 and 3 in fig. 2; castelletti et al., 1992; moroni lanfrendini, 1995-1996), by two open-air sites which yielded pottery decorated with the late neolithic chassey style and pot-shapes and handles typical of the early eneolithic of central italy. the middle eneolithic is currently attested by sporadic material, while the late eneolithic/early bronze age period (vaso campaniforme stage) is represented by the consuma 2 and salcastrino delle lole sites (fig. 3f-i) (sites 2 and 4 in fig. 2; moroni, 1990; guidi & moroni lanfredini, 2001). the bronze age, particularly its middle stage, marks a period of wider occupation in the plain close to the tiber river banks or in the narrow valleys of its tributaries. almost the whole of the early middle bronze age sites is on the tiber floodplain (salcastrino delle lole upper layer, consuma 4, gragnano; sites 2, 4, 5 in fig. 2; moroni lanfredini & ronchitelli, 1997; guidi & moroni lanfredini, 2001). the middle bronze age (apennine phase) recorded at gorgo del ciliegio (site 6 in fig. 2; fig. 3l-m; arrighi & moroni lanfredini, 2004) and around caprese michelangelo, points to settlements on the higher slopes. a significant fig. 1 generalized geological maps: a) distribution of intermontane basins of the northern apennines. codes of the basins: lu: lunigiana; vm: val di magra; mtc: montecarlo; fpp: firenze-prato-pistoia; mu: mugello; ca: casentino; va: upper valdarno; ch: valdichiana; utb: upper tiber basin; tib: tiberino (after sani et al., 2009); b) schematic geology of the utb; atf: alto tiberina fault. the boxed area represents the portion of the basin investigated in this study (fig. 2). late quaternary upper tiber basin 33 fig. 2 detailed geological map and cross section of the study area with the location of selected archaeological sites discussed in the text: 1: castel di sorci; 2: consuma 1-4; 3: moresco; 4: salcastrino delle lole; 5: gragnano; 6: gorgo del ciliegio; 7: trebbio. atf: alto tiberina fault; af: anghiari fault; ssf: sansepolcro fault. benvenuti m. et al. 34 fig. 3 archaeological materials from the utb: a-c) middle paleolithic stone tools from castel di sorci: a) levallois core; b) sidescraper; c) point; d-e) aurignacian burins de vachons; f-i) late eneolithic/early bronze age flint arrowheads from various sites. the division of the graduate bar for a) to i) is 1 cm; l) the gorgo del ciliegio site excavated in the late summer of 2011: the semi-circular ditch and some postholes (white arrows) attests to dwelling remains, persons for scale; m) a selection of pottery from the gorgo del ciliegio site, the rod for scale is 20 cm long; n) an oven from the iron age trebbio site, reused as a dustbin for pottery and other materials. rod for scale is 20 cm long. late quaternary upper tiber basin 35 occupation of the floodplain during the iron age is recorded south of sansepolcro by a 20-hectares wide proto-urban settlement (trebbio, site 7 in fig. 2; iaia & moroni lanfredini, 2009), characterized by well-developed handicraft activities mostly related to pottery production (fig. 3n). when plotted against time, the prehistoricprotohistoric archaeological record of the utb, thus, shows a pattern of documented cultural stages separated by quite long periods of missing or occasionally represented cultures (fig. 4a). the calibration of artefact assemblages mostly collected within the deposit of the different units described below has been obtained by a variety of methods, reported in the papers cited above, including comparison with well-dated archaeological materials from other italian localities, and radiocarbon dating of charcoal derived from the human activity. 4. geomorphology and stratigraphy of the latest middle pleistocene-holocene succession the landforms and the underlying sediments referred to units mup and hol (fig. 2) are briefly described in this section providing a geomorphologic picture quite different from those represented in the existing geological maps (jacobacci & malatesta, 1969; pialli & plesi, 2009). 4.1. mup unit landforms and deposits referred to this unit (fig. 2) are further subdivided in sub-units mup1-3 on the base of geomorphologic and stratigraphic lines of evidence. 4.1.1. mpu1 sub-unit arenaceous-ophiolitic boulder to pebble-sized gravels (mup1) is exposed for few meters at a road cut nw of anghiari. the gravels are poorly stratified and show a clast-supported texture with abundant sandysilty interstitial matrix. clasts are rounded to wellrounded showing an embrication hinting to paleocurrents from nw. this outcrop is at the base of a fanshaped, relief considered the evidence of a small alluvial fan fed by the paleosovara creek that flowed from nw to se. a sw-ne trending fault (carmine fault in fig. 2) that places the ophiolites of the ligurid units in contact with these and older quaternary deposits of the anghiari hill, suggests a tectonic control on a possible diversion of the sovara creek, today flowing to sw. 4.1.2 mpu2 sub-unit remnants of a fluvial terraced surface occur on the right of the sovara creek with a wider patch near castel di sorci, a few kilometers se of anghiari. at this location, the terrace, standing about ten meters above the modern valley floor, contains gravel, sand and mud referred to the mup2 sub-units. these deposits are affected by a deep yellowish-reddish paleosol bearing middle paleolithic stone implements (fig. 3a-c; cocchi et al., 1978; moroni lanfredini & benvenuti, 2010; moroni et al., 2011). 4.1.3. mpu3 sub-unit the tiber river plain between montedoglio dam and santa fiora village is a large nw-se trending fanshaped surface topographically outlined by contour lines oriented transversally to the basin (fig. 2). such morphology indicates an abandoned large alluvial fan possibly fed by the tiber and/or singerna rivers. the latter behaved as distributive fluvial systems (hartley et al., 2010), that is, axial rivers flowing into a subsiding basin that expand into terminal alluvial fans. notably, the occurrence of such a large relict fan in the tiber plain is not detectable in the existing geological maps (jacobacci & malatesta, 1969; pialli & plesi, 2009), which represent it as the active floodplain of the tiber river (tab. 1). the deposits subtended by this fan-shaped plain are referred to sub-unit mup3 and have been partially observed in a 2.5 meters deep excavation (fig. 5a, location on fig. 2). from the base, the deposits consist of about 2 meters thick clast-supported and wellrounded arenaceous pebble-sized gravels and sand affected on top by a well-developed reddish paleosol. this is buried by medium-fine yellowish sand, 0.5 meters thick. the buried soil suggests that the fan remained morphologically stable for a relatively long time, later on covered by the toe of a small alluvial fan (hol 1 subunit, see below) fed by a local stream and not by the main tiber river. the soil development, thus, indicates that the fan was abandoned due to a possible feeder deviation. the nw-se trend of the mup3 fan does not geological map of italy, 1:100,000 sheet 115 “città di castello” geological map of italy, 1:50,000 sheet 289 “città di castello” this study dt (slope talus) q1 (“old” terraced alluvial deposits) q2 (terraced alluvial deposits) a (recent alluvial deposits) b2 (colluvial deposits) bn (terraced alluvial deposits) b (recent alluvial deposits) hol1-3 sub-units mup3 sub-unit qt2 (fluvio-lacustrine clay, sand and gravel) mct2 (monterchi synthem: anghiari sub-synthem) mup1-2 sub-units ang1-2 sub-units cta2a-cta2c (citerna synthem: monte rodondo sub-synthem) mcf2 sub-unit qt1 (lacustrine clay) fhl (citerna synthem: fighille sub-synthem) mcf1 sub-unit tab. 1 comparative scheme of the stratigraphic subdivisions adopted in this study and in the existing geological maps (jacobacci & malatesta, 1969; pialli & plesi, 2009) of the study area. benvenuti m. et al. 36 match the wsw-ene orientation of the present tiber valley upstream the montedoglio dam fitting on the contrary the proximal valley reaches of the singerna and tiber rivers which may represent the original fan feeders, then displaced by a ne-sw dextral fault (montedoglio fault in fig. 2; see sani et al., 2009). a few km east of san pietro in villa (fig. 2), a further n-s trending fanshaped hill faces the nw corner of the tiber plain. despite the lack of outcrops, the surface sediments are arenaceous and subordinate calcareous gravels indicating a thin clastic sedimentary cover on the ligurid limestone and marlstone bedrock. this landform and the related clastic deposits are ascribed to mup3 subunit and interpreted as the evidence of a further small alluvial fan originally prograding in the tiber plain and then beheaded from its original fluvial feeder. the latter was the precursor of the tignana creek whose entrenched valley is characterized by a proximal n-s trending reach, coaxial with the san pietro in villa fan. in proximity of the nw prosecution of the sansepolcro fault, the valley turns in a ne-sw trend reach. this evidence suggests that also the tignana creek may have diverted as the consequence of active faulting. 4.2. hol unit landforms and deposits ascribed to the hol unit (fig. 2), occur in the lowermost and partly still active alluvial plains. this unit is further subdivided in the hol1-3 sub-units coinciding with three distinct alluvial surfaces. 4.2.1. hol1 sub-unit the hol1 alluvial plain is entrenched in the mup and older units. the distribution of this landform in the tiber river valley as well as in the valleys of its tributaries, testifies to the development of stream channels and adjacent floodplains upstream from the bridge between santa fiora village and sansepolcro town (fig. 2). downstream, the hol1, though dissected by the hol2 and the modern river network (hol3), widens in a surface that hints to a further tiber alluvial fan. a lobed morphology, with a main ne-sw oriented axis, ascribed to this sub-unit characterizes also the plain of the adjacent afra creek, suggesting the possible coalescence of the tributary hol1 afra fan. the deposits subtended by these surfaces are not exposed and a partial view of the hol1stratigraphy derives from the excavation of the consuma 2 site before the valley flooding upstream the montedoglio dam (fig.2; moroni, 1990). in a 3-meter deep trench excavated in deposits morphologically correlated to the hol1 sub-unit, the lower part consisted of brownish pebblesize and clast-supported conglomerate (fig.5b), overlain by mottled sandy mudstone with pebbly lenses on top. fig. 4 archaeology and chronology of the utb: a) the archaeological stages documented in the utb and the approximate duration of the morpho-stratigraphic units. hatched intervals refer to missed cultural stages possibly due to: 1) still not discovered materials, 2) prevented occupation of unsafe alluvial plains, 3) materials eventually buried by alluvial deposition; b) the basin stratigraphy compared with the chronostratigraphy, magnetostratigraphy and marine isotope stages of the late quaternary. late quaternary upper tiber basin 37 final epigravettian stone tools (moroni, 1990) have been found in the middle of these deposits together with isolated arenaceous cobbles. the upper part was characterized by a lag of pebble-sized conglomerate overlain by massive dark mudstone bearing late eneolithicearly bronze age stone tools indicating a middle holocene reoccupation of this river bank. at the sw margins of the tiber plain, slope deposits and small alluvial fans developed at the foot of the anghiari hills represent the hol1 sub-unit. these fans, fed by the gravel-rich ang1-2 units, evidently graded at a base level different from that of the main river network. the inferred activity of the anghiari fault (delle donne et al., 2007) and the confinement of the mup3 fan lobe, concurrently determined a local topographic low for the fan deposition fed by the short and steep creeks draining the anghiari hill. 4.2.2 hol2-3 sub-units in the tiber plain the landforms and deposits ascribed to hol2 unit point to a geomorphic development similar to that recorded by the hol1. a river channel entrenchment widens downstream in a relatively larger plain attesting to a progressive telescopic shift toward se of the tiber fluvial-fan complex. similarly to the previous unit, small alluvial fans graded to a higher base level with respect to the hol2 plain. notably, the alluvial fans ascribed to hol2 sub-unit occur only se of santa fiora on the left of the tiber river. the hol2 afra fan is the largest one. unit hol3 represents the recent fluvial landforms in the plain. these are related to the narrow (and up to 5 meters deep) river valleys incised in the older units and by small alluvial fans that aggraded onto the fans of the hol2 unit. the related deposits have been investigated in a trench excavated on the left of the modern afra channel, about 0.9 km ne of the trebbio site (figs.5c; 2 site 7). the alluvial succession is composed of about 1.30 meters of mottled muddy sand with land snail shells referred to the distal portion of the hol1 afra fan. these deposits are overlain by 0.8 m thick lenticular gravel bed that records a hol3 palaeoafra channel, in turn overlain by 0.4 meter thick muddy sand representing the overbank deposits of the nearby active afra channel. 5. the archaeological contribution to a chronologic constraint of mup and hol units the ancient human occupation of the utb is considered largely controlled by the alluvial dynamics recorded by the mup and hol units, which in turn resulted from a balance between active tectonics and climate variations. from one side the material evidence of occupation of alluvial plains is considered a proof of local reduced alluvial sedimentation and attitude to flooding, conditions that made safe the temporary and/or stable settling of human communities on these surfaces. from the other side the gaps in the archaeological record of the utb, beside indicating still undiscovered cultural stages, may reflect: 1) sporadic and/or absent occupation of areas of active alluvial deposition such as the documented large alluvial fans or 2) sediment deposition that buried any material evidence of possible land occupation. fig. 5 stratigraphy of selected trenches excavated in the utb: a) the stratigraphic profile in the trench dug onto the mup3 singernatiber fan, location in fig. 2); b) the consuma 2 site stratigraphy (location in fig. 2 site 2); c) hol3 palaeoafra channel fill (delimited by the dotted white line) resting over the distal deposits of the hol 1 afra fan. the gravelly channel fill is characterized by a pillar-like structure protruding into the underlying muddy sand which hints to the liquefaction of the latter deposits, of possible paleoseismic origin. trench location in fig. 2. benvenuti m. et al. 38 under these assumptions the archaeological record, included its hiatus, may be considered for dating the depositional stages represented by the units and sub-units described above (fig. 3a). 1) the middle paleolithic stone tool assemblage found within the mup2 deposit of the castel dei sorci terrace indicates that possibly around 130-100 ka ago neanderthal populations moved on the anghiari hills flanked to sw by a terraced paleosovara valley. the fault-controlled deactivation of the mup1 sovara fan was followed by the incision of a mup2 sovara valley trending as the present one. 2) from the anghiari hills neanderthals could have seen the mup3 fans in the plain, which were active up to the latest pleistocene. this chronologic reference is suggested by the final epigravettian tools, collected in the stratified consuma 2 site, upstream the montedoglio dam, and confidently referred to about 12 ka ago. the latest palaeolithic people occupied the left bank of the wswese trending tiber valley evidently when the mup3 fans would have been inactive due to the fault-controlled deviation of the singerna-tiber and tignana rivers. the long span of time, characterized by the missing of most of the late paleolithic during the late pleistocene, coincided with huge sedimentation on the tiber alluvial fan that may have prevented a stable human occupation of the plain and/or may have buried any artefact. 3) similarly, the missing/sporadic mesolithic and neolithic stages suggest that the tiber valley floor was unsuitable for stable human occupation also during the early holocene. the hol1 sub-unit developed during this span of time. 4) the geomorphic setting related to less intense fluvial processes evidently determined favourable condition for a safe settling on the valley floor since the eneolithic and particularly in the mid-late holocene when the alluvial plains were occupied by bronze-iron ages people. hol 2 unit testifies to a period of renewed alluvial-fan development particularly in the afra creek plain. here the human occupation shows a gap from the middle eneolithic (moresco site) to the iron age (trebbio site) which is considered an approximate duration of the hol2 afra fan development. 5) finally, the large trebbio settlement in the afra plain is indicative of the human presence during the development of the hol3 sub-unit. the latter marks a period of generalized fluvial incision in the basin and definitive deactivation of the large alluvial fans, which established safe hydraulic conditions on the terraced alluvial plains. despite the active tectonic setting may have represented a primary factor controlling the alluvial dynamics, autogenic processes of alluvial-fan deposition (schumm et al., 1987; de celles et al., 1991) may be not ruled out. the progressive south-eastward migration of mup3-hol2 alluvial fans in the tiber plain may have also determined by channel entrenchment in response to local modification of base level induced by the fan lobes. when compared with the marine isotope stratigraphy (fig. 3b), the latest middle pleistocene-holocene alluvial deposits and landforms of the utb reasonably encompass at least two major glacial/interglacial cycles including the marine isotopic stages (mis) 7-1. the effects of these climatic changes on water discharge, sediment production and transfer may have affected the geomorphic dynamics recorded by the mup and hol units. an analysis of the fluvial response to climate change during the last 200 ka in the mediterranean basin (macklin et al., 2002), indicates that, despite differences related to local morpho-tectonic settings, alluvial deposition occurred particularly during glacial stages (i.e mis6 and between the late mis5 and mis2). in the studied case this seems confirmed by the large mup3 tiber fan whose development reasonably encompasses the mis 4-2 interval. due to an uncertain dating of mup1-2 sub-units, older than 130 ka, at the moment clear relations with glacial/interglacial stages cannot be established and a partial correlation to mis 7 and 6 is only hypothetic. 6. conclusions a portion of the alluvial intermontane upper tiber basin and its occupation by ancient human communities have been investigated through the integration of geomorphology, stratigraphy and archaeology. not excluding intrinsic factors, alluvial deposition, recorded by the mup and hol units, was primarily influenced by an active tectonic setting characterized by orthogonal nw-se and ne-sw trending fault systems which created sediment accommodation through differential subsidence and forced river deviations through vertical and lateral displacement of faulted blocks. the spatial and chronological distribution of late prehistoric-protohistoric archaeological findings, collected on and within these units, has allowed an indicative dating of the major stages of fluvial network modification occurred between the end of the middle pleistocene and the late holocene. this chronologic calibration indicates that, besides the active tectonic setting, the morphostratigraphic events recorded in the described units have occurred within two major glacial-interglacial cycles. the latter may have controlled the local surface hydrology and the sediment supply to the fluvial systems. accordingly, gaps in the archaeological record, including most of the late paleolithic, the mesolithic and the early neolithic, attest to stages of huge alluvial deposition in a highly subsiding basin. this may have determined the burial of the missing cultural stages or may have prevented any occasional or stable occupation in lowlands during the development of large alluvial fans. from a methodological point of view the integration of geological and archaeological data, adopted in this study, demonstrate the potentiality of cooperation between physical and human sciences in revealing the complex interaction of man and environment. acknowledgements the authors are indebted with luca trombino, marco mancini and an anonymous reviewer for the constructive comments to an early version of this paper. the authors are also grateful to the archaeological office of tuscany which authorized and supported the research in the upper tiber valley over the years and to centro studi sul quaternario onlus for its assistance during excavations. late quaternary upper tiber basin 39 references argenti p. (2003-2004) plio-quaternary mammal fossiliferous sites of umbria (central italy). geologica romana, 37, 67-78. arrighi s., moroni lanfredini a. (2004) l’insediamento appenninico di gorgo del ciliegio (sansepolcro arezzo). in: negroni catacchio n. (ed), miti simboli decorazioni ricerche e scavi.vi incontro di studi preistoria e protostoria in etruria, proceedings volume 1, 505-507. arrighi s., borgia v., moroni lanfredini a., ronchitelli a. (2006) burins des vachons en italie: typologie, morphotechnique et tracéologie. archéologiques, 2, 103-118 barchi m., ciaccio m. (2004) ricostruzione geometrica del bacino di sansepolcro dall’interpretazione di profili di sismica a riflessione. 23th gngts meeting, abstract volume,195-196. benvenuti m. (1989) stratigrafia e sedimentologia delle colline di anghiari nella valtiberina superiore. unpublished laurea dissertation, università degli studi di firenze, 80 pp. borgia v., moroni lanfredini a. (2004) le peuplement de la haute vallée du tevère durant l’acheuléen (arezzo, italie). 14th congress uispp, bar international series 1272, 193-200. brown a.g. (1997) alluvial geoarchaeology: floodplain archaeology and environmental change (cambridge manuals in archaeology). cambridge university press, 404 pp., cambridge, u.k. castelletti l., martinelli m.c., maspero a., moroni a. (1992) ii sito neolitico della consuma 1 (pieve s. stefano-arezzo). rivista di scienze preistoriche, 44, 44-114. cattuto c., cencetti c., fisauli m., gregori l. (1995) i bacini pleistocenici di anghiari e sansepolcro nell’alta valle del tevere. il quaternario 8(1), 119-128. ciangherotti a., esu d. (2000) paleoecologic and biochronologic meaning of the early pleistocene molluscan fauna from the anghiari basin (tiber river upper valley, central italy). bollettino della società paleontologica italiana, 39, 217-224. cocchi d., gambassini p., laurenzi g. (1978) l’industria paleolitica di castel di sorci fra anghiari e sansepolcro (arezzo). rivista di scienze preistoriche, 33, 283-303. de celles p.g., gray m.b., ridgway k.d., cole r.b., pivnik d.a., pequera n., srivastava p. (1991) controls on syn-orogenic alluvial-fan architecture, beartooth conglomerate (paleocene), wyoming and montana. sedimentology, 38, 567-590. delle donne d., piccardi l., odum j.k., stephenson w.j., williams r.a. (2007) high resolution shallow reflection seismic image and surface evidence of the upper tiber basin active faults (northern apennines, italy). bollettino della società geologica italiana, 126, 323-331. guidi r., moroni lanfredini a. (2001) l’età del bronzo nell’alta valtiberina toscana. 34th meeting iipp, proceedings, 427-439. hartley a.j., weissmann g.s., nichols g.j., warwick g.l. (2010) large distributive fluvial systems: characteristics, distribution, and controls on development. journal sedimentary research, 80, 167-183. iaia c., moroni lanfredini a. (eds.) (2009) l’età del ferro a sansepolcro, attività produttive e ambiente nel sito di trebbio. aboca museum edizioni, perugia. jacobacci a., malatesta a. (1969) carta geologica d’italia in scala 1:100.000, foglio 115 “città di castello”. servizio geologico d’italia. macklin m.g., fuller i.c., lewin j., maas g.s., passmore d.g., rose j., woodward j.c., black s., hamlin r.h.b., rowan j.s. (2002) correlation of fluvial sequences in the mediterranean basin over the last 200 ka and their relationship to climate change. quaternary science reviews, 21, 1633-1641. moroni a. (1990) il paleolitico superiore e l’eneolitico di la consuma (pieve s. stefano, arezzo). rassegna di archeologia, 9, 250-289. moroni a., abati f., baldanza a., coltorti m., de angelis m.c., mancini s., moroni b., pieruccini p. (2011) l’alto e medio bacino del tevere durante il paleolitico medio. ipotesi sul popolamento e la mobilità dei gruppi di cacciatori raccoglitori neandertaliani. bollettino di archeologia, 2-3, 171-201. moroni lanfredini a. (1995-1996) ii moresco (sansepolcro, prov. di arezzo). rivista di scienze preistoriche, 47, 439-440. moroni lanfredini a., benvenuti m. (2010) alta valtiberina toscana. preistoria e protostoria di un territorio. le ricerche, gli aspetti culturali, il paleoambiente. ipotesi di preistoria, 3, 1-26, http://ipotesidipreistoria.unibo.it/article/view/1874. moroni lanfredini a., ronchitelli a. (1997) gragnano (sansepolcro, prov. di arezzo). rivista di scienze preistoriche, 48, 431-432. moroni lanfredini a., ronchitelli a. (2001) s. cassiano, un sito a bulini dei vachons. osservazioni tipologiche e tecnologiche. 34th meeting iipp, proceedings, 325 335. pialli g., plesi g. (2009) carta geologica d’italia in scala 1:50.000, foglio 289 “città di castello”. ispra servizio geologico d’italia. sani f., bonini m., piccardi l., vannucci g., delle donne d., benvenuti m., moratti g., corti g., montanari d., sedda l., tanini c. (2009) late pliocenequaternary evolution of outermost hinterland basins of the northern apennines (italy), and their relevance to active tectonics. tectonophysics, 476, 336-356. schumm s.a., mosley m.p., weaver w.e. (1987) experimental fluvial geomorphology. wiley interscience, 413 pp., new york. van waveren e. (1986) ecologia del paesaggio dell’alta valle del tevere (dati di base integrati per la land evaluation). giunta regionale toscana, patron editore, 117 pp. walker m. (2005) quaternary dating methods. wiley, 286 pp., uk. woodward j., huckleberry g. (2011) the geoarchaeology of river basin systems: an introduction. geoarchaeology, 26, 611-615. ms. received: september 20, 2012 final text received: february 26, 2013 << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /all /binding /left /calgrayprofile (gray gamma 2.2) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /warning /compatibilitylevel 1.4 /compressobjects /tags /compresspages true /convertimagestoindexed true /passthroughjpegimages true /createjobticket false /defaultrenderingintent /default /detectblends true /detectcurves 0.1000 /colorconversionstrategy /leavecolorunchanged /dothumbnails false /embedallfonts true /embedopentype false /parseiccprofilesincomments true /embedjoboptions true /dscreportinglevel 0 /emitdscwarnings true /endpage -1 /imagememory 1048576 /lockdistillerparams false /maxsubsetpct 100 /optimize true /opm 1 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documenti pdf creati possono essere aperti con acrobat e adobe reader 5.0 e versioni successive.) /enu (use these settings to create adobe pdf documents suitable for reliable viewing and printing of business documents. created pdf documents can be opened with acrobat and adobe reader 5.0 and later.) >> >> setdistillerparams << /hwresolution [1200 1200] /pagesize [396.850 566.929] >> setpagedevice amq107 baneschi et al.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 33 (1), 2020, 99-106 are stable isotopes of lacustrine carbonate a good tracer of lake hydrology and lake level variability? the lake ledro case (northern italy). ilaria baneschi 1, michel magny 2, giovanni zanchetta 3, 4, 5 1 istituto di geoscienze e georisorse igg-cnr, pisa, italy. 2 laboratoire de chrono-environnement, umr 6249 du cnrs, ufr des sciences et techniques, besançon, france. 3 dipartimento di scienze della terra, university of pisa, pisa, italy. 4 centre for climatic change impact cirsec, university of pisa, pisa, italy. 5 istituto di geologia ambientale e geoingegneria, igag-cnr, rome, italy. corresponding author: i. baneschi <i.baneschi@igg.cnr.it> abstract: oxygen and carbon isotopes were analysed on bulk samples and carbonate concretions from lake ledro, northern italy, with the aim to assess their suitability as reliable proxy of the hydrological changes in the lake. for this purpose, isotopic composition of bulk marls and concretions were compared to lake level reconstruction obtained with sedimentological approach. the δ13cbulk record mostly mirrors the δ18obulk record, while carbon and oxygen isotopes from concretions are not correlated. we found that there is a statistically significant correlation between the oxygen and carbon isotopic record of the bulk carbonate and lake level changes, with the positive changes in lake level corresponding to lower values on δ18obulk and δ13cbulk and vice versa. assuming that most of the bulk carbonate is formed by bio-induced calcite precipitation, this means that this kind of carbonate reflects the local hydrological condition of the lake water better than lacustrine concretions, which instead are more affected by local conditions of precipitation like biological plant activity. keywords: stable isotopes carbonate; lacustrine carbonates; lake level; lake ledro. 1. introduction the hydrological balance of lakes may respond sensitively to changes in net precipitation and humidity, which often are accompanied by change in the lake level. hence, the lake level is a sensitive proxy that document past changes in lake water budget, and past climate (e.g., magny, 2013 and reference therein). in lacustrine settings, stable isotopes of carbonates are a frequently used as proxy to identify and reconstruct terrestrial environmental changes and have been extensively used in quaternary paleoenvironmental reconstructions (e.g., eicher & siegenthaler, 1976; punning et al., 1984; lotter et al., 1992; mayer and schwark, 1999; zanchetta et al., 1999; schwander et al., 2000; hammarlung et al., 2003; andresson et al., 2010; jonsson et al., 2010; whittington et al., 2015). the oxygen isotopic composition of inorganic lake carbonate is mainly influenced by: (1) the oxygen isotope composition of precipitation in the watershed, (2) the water temperature at time of carbonate precipitation, and (3) the hydrological balance of the lake (buchardt & fritz, 1980; gibson et al., 1993; von grafenstein et al., 2000; ito, 2001; leng & marshall, 2004; bernasconi & mckenzie, 2007). in specific conditions, the hydrological balance dominates the oxygen isotopic signal of water lakes and, consequently, that of inorganic carbonates (roberts et al., 2008). so it should be related to changes in lake level. despite this argumentation is commonly used as rational for interpreting the isotope signal as proxy of the lake level change (e.g., leng et al., 2010), there are very few examples of direct comparison between lake level records and oxygen isotope composition of lake carbonate. a comparison between bulk lacustrine carbonate stable isotopes and changes in lake level reconstructed using sedimentological approach (magny, 1992, 1998) have been performed for instance on the study of gerzensee lake, on the swiss plateau at 603 m a.s.l., and lautrey lake, located at 788 m a.s.l. in the jura mountains (eastern france) (magny, 2001, 2013; magny et al., 2006). when using the carbon and oxygen isotopes for lake level reconstruction, many complex factors have to be carefully taken into account. usually, the interpretation of the 13c/12c ratio in lacustrine carbonate is more complex than that of 18o/16o ratio. variations of δ13c values of precipitated calcite in general reflect the δ13c values of the dissolved inorganic carbon (dic), which is controlled by the isotopic composition of incoming waters, the exchange of co2 between lake surface waters and the atmosphere, by photosynthesis and respiration of algae and aquatic macrophytes, and by organic mat https://doi.org/10.26382/amq.2020.09 100 baneschi i. et al. ter decomposition (mckenzie, 1985; lee et al., 1987; meyers & teranes, 2001; teranes & bernasconi, 2005) as well as by carbonate dissolution in the water column. moreover, the input and the isotopic composition of the dic from the catchment depends on several factors such as leaching of soil co2 and dissolution of old carbonates (leng & marshall, 2004; zanchetta et al., 2018). several types of lacustrine carbonates can be studied, like bio-induced carbonates (the most common, sometime called authigenic carbonates; eicher & siegenthaler, 1976; hammarlund et al., 1999, 2003), freshwater shells (e.g. bottger et al., 1998; zanchetta et al., 1999; bonadonna et al., 1999; jones et al., 2002), ostracods (e.g. von grafenstein et al., 1994, 1999; lézine et al., 2010) and chara encrustations (apolinarska & hammarlund, 2009). however, each different type of carbonate forms in specific conditions and, therefore, may give a different type of information (leng & marshall, 2004). in this work, we further explore the relation between oxygen and carbon isotopes and lake level changes using data on bulk carbonates (mainly bioinduced) and lake concretions in cores recovered in lake ledro within a holocene succession, for which chronology and lake level reconstruction has already been performed (magny et al., 2009). 2. site description lake ledro is located at 652 m a.s.l. on the southern slope of the alps (n-e italy, fig. 1), with a surface area of ca. 2.17 km2, a maximum water depth of 48 m, a mean depth of 35 m, and a volume of ca. 0.75 km3. the catchment area is ca. 131 km2 and is developed on a substratum mainly composed by carbonate rock, including triassic (dolomite) and jurassic-cretaceous limestones covered by quaternary glacial deposits. the outlet of the lake is ponale river, which is responsible for the downcutting of the local morainic dam (beug, 1964) and hydrologically links lake ledro to the lake garda (fig. 1). since 1929, the lake level has been artificially regulated for hydroelectric power supply, modifying consequently the natural hydrological variability. lake ledro is fed by many submerged springs and by some minor temporary torrential tributaries: ponale massangla, assat di cencei and sat di pur, which are dry for most of the year. fig. 1 location of lake ledro catchment with an outline map showing the study site in northern italy. the circle marks the core site (core ledro ii). the thick black line indicates the sub-catchment of the different inlet rivers. 101 stable isotopes of carbonate as tracers of lake hydrology the climate of ledro valley is influenced by the near garda lake (65 m a.s.l.), characterized by particularly mild climatic conditions. the mean temperature, recorded at bezzecca weather station (710 m a.s.l.), is ca. 0 °c in the coldest month (january) and ca. 19 °c in the warmest month (july). the mean annual precipitation is ca. 1220 mm, with seasonal maxima in spring and autumn. lake ledro waters can be classified as ca-bicarbonate and are stratified during summer period (corradini & flain, 2000). the yearly mean isotopic composition of precipitations collected from five stations from 1992 to 2001 around the garda area and reported by longinelli & selmo (2003) is -7.47 ±0.91 ‰ for δ18o and -49.3 ±7.3 ‰ for δ2h. the weighed mean isotopic values of precipitations measured at riva del garda from february 2007 to january 2008 (longinelli et al., 2008) is -7.25 ±0.70 ‰ for δ18o and -52.1 ±5.9 ‰ for δ2h. 3. materials and methods the present study was carried out on the core retrieved in april 2005 at the site ledro ii, located on the north-eastern shore of the lake (fig. 1). here, a ~ 3 m long core was collected by means of a russian peat corer (magny et al., 2009). the sedimentary succession, under the superficial peat layer, shows an alternation of carbonate lake-marl and organic-rich layers. detailed core description, chronology, pollen and lake-level reconstructions are extensively discussed by magny et al. (2009, 2012), to which the readers are referred for any details. the recovered sediments, dated by means of radiocarbon, represent ca. the last 7000 yr bp. the carbonate lake-marl samples and carbonate concretions were sampled for oxygen and carbon isotopes on bulk carbonate about every 3-4 cm. sediments were sieved at 200 μm. the term “bulk carbonate” is here used for the fine-grained inorganic lake marl (less than 200 μm), mostly devoid of shell and ostracods remains. the carbonate concretions where hand-picked under a binocular microscope from the coarser fraction (larger than 200 μm). this latter material corresponds to the original material selected by magny et al. (2009) for defining lake level oscillations based on different typology of lacustrine concretions (magny, 2004). concretions were cleaned ultrasonically with distilled water to separate adhering particles. the sediment samples were dried at 40°c, powdered and analysed for isotopic composition with no further pre-treatment considering the high carbonate content (manella et al., 2020). all the carbonate samples were reacted with 100% phosphoric acid at 70 °c for 1 h under vacuum to release co2. the released co2 was then cryogenicallycleaned in a vacuum line and analysed in the mass spectrometry varian mat 252. the results were expressed with the well-known δ-notation and normalized to the vienna pee dee belemnite scale (pdb in per mil) using internal working standards of carbonatems, mab (carrara marble) and mom, which were cross-checked against the international standard nbs18. the precision (as standard deviation) of the analyses was better than 0.2‰ for δ13c and 0.2‰ for δ18o. 4. results figure 2 shows isotopic composition of the bulk and carbonate concretions, compared to lake level data vs depth. the δ18o values of bulk sediment (δ18obulk) vary in a range of ca. 1.6 ‰ from ca -10.4 to -8.8 ‰, very similar to the range (ca. 1.7‰) of δ18o values of concretions (δ18oconcr) but the maximum and minimum δ18oconcr values are lesser negative, ranging between 9.7 and -8.0 ‰. indeed, considering each couple of δ18obulk and δ18oconcr at the same depth, the δ18oconcr has higher oxygen isotope composition than δ18obulk. this means that the difference between δ18oconcr and δ18obulk is usually positive (fig. 2) with a mean value of 0.8 ‰ and a range from 1.9 to -0.1‰. the δ13c values of bulk sediment (δ13cbulk) fluctu fig. 2 stable carbon and oxygen isotope records of different carbonate components, together with lake level changes, plotted against core depth. ate in a wider range of ca. 3 ‰, i.e., from ca. -2.9 to -5.9 ‰ (fig. 2). the carbon isotopes of concretions are offset from the corresponding values of bulk carbonate of 0.8 ‰ on average with a range from -2.5 to +0.5 ‰. the δ18obulk record is characterized by a relatively low variability from the bottom to around 190 cm, from which frequent and short fluctuations start and minimum δ18o values are reached at around 173 cm, 147-144 cm, 118-104 cm, 89 cm, 55 cm, 47 and 22 cm. the δ18o of concretions shows similar fluctuations toward more negative values at 173 cm, 144 cm and 104 cm, even if in general there is not a statistically significant correlation between the two records (r=0.22, n=32). the δ13cbulk record mostly mirrors the δ18obulk one with a good correlation (r=0.59, n=67), in contrast to the carbon and oxygen values of concretions that are not significantly correlated (fig. 3). this is probably related to the presence of different kind of concretions, but also to the different, local, nature of the environment where lacustrine concretions forms compared to bio-induced carbonates. the δ13cbulk values are generally 13c-depleted from the bottom of the record to 230 cm, when the values start to increase reaching the maximum of -3.8 ‰ at around 200 cm. it has to be noted that from 250 to 175 cm there are not samples of concretions analysed because there was not sufficient material, in accord by the fact that the core from 240 to 190 cm is characterized by peat and gyttja and that from 230 cm to 190 cm there are only organic remains without concretions (magny et al., 2009). from 200 cm to the top of the record, δ13cbulk is characterized by frequent fluctuations with the lowest and highest values corresponding to the lowest and highest values on the oxygen record of bulk carbonates, respectively. 5. discussion δ18o of inorganic carbonates in small/medium open lakes, like lake ledro, dominantly reflects the δ18o of the water during calcite precipitation (ito, 2001; leng & marshall, 2004; teranes et al., 1999). authigenic calcite inorganically precipitates in late spring/early summer in the epilimnion because of changes in lake water chemistry (increased temperature, algal activity and ph changes). however, inorganic carbonates may also be formed as an extra-cellular by-product during photosynthesis. for example, characeae and other microand macrophytes actively remove bicarbonate from the lake system, leading to the formation of inorganic calcite, which typically encrusts the plants (von grafenstein et al., 102 baneschi i. et al. fig. 3 δ18o versus δ13c diagram for the core record of both bulk and concretions. fig. 4 stable carbon and oxygen isotope records of different carbonate components plotted against lake level changes. (bini et al., 2019). overall, we can then assume that higher δ18o values of carbonates correspond to drier period, in which lake level also decreases. considering the lake level reconstructed by magny et al. (2009) from ledro core, the data showed in figure 2 highlight that there is a good correspondence between the oxygen and carbon record of the bulk carbonate, with the positive changes in lake level corresponding to lower values on δ18obulk and δ13cbulk and, vice versa, with negative changes in lake level corresponding to higher values on δ18obulk and δ13cbulk. this behaviour is evident also for the carbon record of concretions, with higher δ13cconcr values corresponding to lower level lake, whereas δ18oconcr shows in some case opposite trends compared to lake level. in fact, considering all the record there is a statistically significant (at 0.05 significance level) negative correlation between the lake level changes with the δ18obulk (r=-0.33, n=67) and the δ13cbulk values (r=-0.30, n=66) (fig.4). the correlation with the concretions and the lake level changes is also negative considering the carbon isotopes record (r=-0.31, n=44), whereas there is a positive correlation with the oxygen isotope record of concretion (r=+0.32). hence, for lake ledro the δ18obulk record correlates quite well with lake level changes, with 18o-depleted values corresponding to phases of lake level increasing (figs 2 and 4). on the contrary, lowering of lake level matches with higher δ18obulk values. this confirms that δ18obulk is can be considered as a reasonably good proxy for lake hydrological changes and lake level, in particular for lakes with simple hydrological budge. δ13c of carbonate is dependent on carbon isotope composition of the dic, controlled by several processes (e.g., leng & marshall, 2004) including: exchange with atmospheric co2, respiratory activity of aquatic plants, mineralization of organic matter and dic isotopic composition of the inflowing water, influenced by the dissolution of carbonate rocks from the catchment and leaching of soil co2. however, δ18obulk and δ13cbulk of lake ledro show a good correlation (fig. 3), which could indicate that data are controlled by the same external factors. period of lower lake level and higher δ18obulk and δ13cbulk can indicate a decrease of contribution of soil-derived co2 by input water and higher equilibration with atmospheric co2 (zanchetta et al., 2018). whereas wetter period can increase the flush of soil co2 and increasing of recycling of organic matter in a deeper lake (whittington et al., 2015; zanchetta et al., 2018). on the other hand, as horton et al. (2016) pointed out, evaporation causes 18o enrichment in water and 13c enrichment in dic. they suggested that evaporation induces increases in alkalinity (i.e. increased bicarbonate concentration) and drives dic 13c-enrichment through isotopic equilibrium exchange with atmospheric co2 (ca. 8‰ at 25°c in the hco3-co2 system; mook et al., 1974). hence, the highest δ13cbulk values are originated by 13cenriched dic due to equilibration with atmospheric co2 (e.g, leng et al., 1999), enhanced by co2 outgassing linked to strong evaporation (talbot, 1990) and the enhanced residence time. in warm conditions, there is also a strong biological activity leading to enhanced 13cenrichment in the water (siegenthaler & eicher, 1986), if 2000). for the lake ledro record, encrustations and macroscopic components were isolated and used for lake level reconstruction (magny et al., 2009) and isotopically analysed together with the isotopic characterization of the fine-grained carbonate matrix, which could be supposed to be composed by a mix of authigenic calcite and disaggregated calcitic concretions, as evidenced for other marl lakes (von grafenstein et al., 2000; apolinarska & hammarlund, 2009). however, it is reasonable to expect that fine-grained matrix bulk carbonate is mostly related to the general water condition in the upper part of the lake water, where algae photosynthesis occurs driving bio-induced calcite precipitation, whereas concretions are more related to local, plant driven, conditions. in general, in hydrologically open lakes with fast turnover, temperature and the isotopic composition of precipitation entering the lake will be the most important drivers of final δ18o values of carbonates. however, in lacustrine system evaporation influences the isotopic composition of lake water in relation to the residence time and to the morphometric characteristic of the lake itself and local climate (gonfiantini, 1986). in particular, in closed lakes, with long residence times, the effect of evaporation will usually be far more important (li & ku, 1997; leng & marshall, 2004; leng et al., 2006). some lakes nearby lake ledro, with different morphometric parameters and elevation, show a seasonal variation on the isotopic composition of their waters, especially in the epilimnetic values, due to evaporation and, in general, their isotopic composition of water is related to hydrological processes (baroni et al., 2006; perini et al., 2009; natale et al., 2013; flaim et al., 2013). lake ledro turnover time is less than 1 year (0.8 years; casellato & caneva, 1994) but considering that the rivers feeding the lake are dry for most of the year, we can hypothesize that the water isotopic composition is mainly controlled by the rate of evaporation, and the supply of local meteoric precipitation and spring waters. in particular, the rate of evaporation would be important in summer. in this situation, we can assume that the oxygen isotopes of lacustrine carbonates should be mainly interpreted as changes in the hydrological budget of the lake rather than changes in temperature (e.g. roberts et al., 2008; zanchetta et al., 2012). higher δ18o values of lake water, especially in the epilimnion, and thus higher δ18o of carbonates, should correspond to phases of reduced precipitation with lower contribution from the torrential tributaries and/or increase of evaporation rate (i.e., drier period), while lower δ18o values should correspond to an increase in the amount of precipitation and/or reduction of the evaporation of lake water (i.e., wetter period). however, this can be complicated by temperature changes and by the changes in the isotopic composition of meteoric precipitation, which act as additional factors that ultimately can either amplify or partially suppress the isotopic signal linked to changes in the rate of evaporation (dansgaard, 1964; rozanski et al., 1992; fricke & o’neil, 1999). because lake carbonates (in particular algal bio-induced precipitation) occur mainly in summer, their isotopic composition is skewed toward this season, even if the winter recharge is important in defining the final isotopic budget 103 stable isotopes of carbonate as tracers of lake hydrology not compensated by recycling. the possible influence of detrital materials could be neglected as supported by the near absence of lithoclasts found in the samples analysed (magny et al., 2009). on the other hand, the absence of correlation between δ18o and δ13c of the concretions could be explained by the different origin of the bio-induced carbonates that form the encrustations. each of these encrustations, differentiated by magny in several morphotypes, should be characterized by different “vital offset”, spaces and times in which they formed. this could lead a strong variability of the different isotope compositions, with no clear and apparent correlation with environmental variables. on the contrary, isotopes of bulk carbonates (in particular the fine fraction) better average the lake conditions and, hence, should be good tracers of hydrological changes of lake itself. conclusions in this work, we used the oxygen and carbon isotope signatures of different type of carbonate (bulk and concretions) from lake ledro to test their suitability in detecting lake-level oscillations and, then, whether they are good indicators of hydrological changes of this lacustrine system. our data confirm that different carbonate types have statistically significant different compositions and reflect hydrological changes in different way. in particular, the isotopic composition of bulk carbonate (grain size below 200 μm) shows a correlation with lake level data, allowing us to consider this geochemical signal a good proxy for lake hydrological changes. on the contrary, the concretion isotope values show high variability and did not correlate with lake level changes. this study further indicates that grain size separation would be an efficient and fast method for improving quality of samples in shallow lake deposit rich in concretions. references andersson s., rosqvist g., leng m. j., wastegard s., blaauw m. (2010) late holocene climate inferred from stable isotope data from a lake record from central sweden. j. quaternary sci., 25, 13051316. apolinarska k., hammarlund d. (2009) multicomponent stable isotope records from late weichselian and early holocene lake sediments at imiolki, poland: palaeoclimatic and methodological implications. j. quaternary sci., 24, 948-959. baroni c., zanchetta g., fallick a.e., longinelli a. (2006) molluscs stable isotope record of a core from lake frassino (northern italy): hydrological and climatic changes during the last 14 ka. the holocene, 16, 827-837. beug h.j. (1964) untersuchungen zur spätglazialen vegetationsgeschichte im gardaseegebiet unter besonderer berücksichtigung der mediterranen arten. flora, 154, 401-444. bernasconi s.m., mckenzie j.a. (2007) lake sediments. in: encyclopedia of quaternary science (ed. by elias s.a.) elsevier, amsterdam, 351-359. bini m., zanchetta g., perșoiu a., cartier, r., català a., cacho i., dean j.r., di rita f., drysdale r.n., finnè m., isola i., jalali b., lirer f., magri d., masi a., marks l., mercuri a.m., peyron o., sadori l., sicre, m.a., welc f., zielhofer brisset e. (2019) the 4.2 ka bp event in the mediterranean region: an overview. climate of the past, 15, 555-577. bonadonna f.p., leone g., zanchetta g. (1999) stable isotope analysis on the last 30 ka molluscan fauna from pampa grassland, bonaerense region, argentina. palaeogeography, palaeoclimatology, palaeoecology, 153, 289-308. bottger t., hiller a., junge f.w., litt t., mania d., scheele n. (1998) late glacial stable isotope record, radiocarbon stratigraphy, pollen and mollusc analyses from the geisental area, central germany. boreas, 27, 88-100. buchardt b., fritz p. (1980) environmental isotopes as environmental and climatological indicators. in: handbook of environmental isotope geochemistry, vol. 1a, the terrestrial environment (ed. by fritz p., fontes j.c.). elsevier, amsterdam, 473504. corradini f., flain g. (2000) caratteristiche limnologiche dei laghi nel trentino. rapporto 1998. istituto agrario di s. michele all'adige, trento, 94 pp. casellato s., caneva f. (1994) composition and distribution of bottom oligochaete fauna of a north italian eutrophic lake (lake ledro). hydrobiologia, 278, 87-92. dansgaard w. (1964) stable isotopes in precipitation. tellus, 16, 436-468. eicher u., siegenthaler u. (1976) palynological and oxygen isotope investigations on late glacial sediment cores from swiss lakes. boreas, 5, 109-117. epstein s., buchsbaum r., lowenstam h.a., urey h.c. (1953) revised carbonate-water isotopic temperature scale. geological society of america bulletin, 64, 1315-1326. flaim g., camin f., tonon a., obertegger u. (2013) stable isotopes of lakes and precipitation along an altitudinal gradient in the eastern alps. biogeochemistry, 116, 187-198. fricke h.c., o’neil j.r. (1999) the correlation between 18o/16o ratios of meteoric water and surface temperature: its use in investigating terrestrial climate change over geologic time. earth planet. sc. lett., 170, 181-196. gibson j.j., edwards t.w.d., bursey g.g., prowse t.d. (1993) estimating evaporation using stable isotope methods: quantitative results and sensitivity analysis for two catchments in northern canada. nordic hydrology, 24, 79-94. gonfiantini r. (1986) environmental isotopes in lake studies. in: handbook of environmental isotope geochemistry, vol. 2b, the terrestrial environment (ed. by fritz p., fontes j.c.). elsevier, amsterdam, 113-168. hammarlund d., edwards t.w.d., bjorck s., buchardt b., wohlfarth b. (1999) climate and environment during the younger dryas (gs-1) reflected by composite stable isotope records of lacustrine carbonates at torreberga, southern sweden. jour 104 baneschi i. et al. nal of quaternary science, 14, 17-28. hammarlund d., björck s., buchardt b., israelson c., thomsen c.t. (2003) rapid hydrological changes during the holocene revealed by stable isotope records of lacustrine carbonates from lake igelsjon, southern sweden. quaternary science reviews, 22, 353-370. horton t.w., defliese w.f., tripati a.k., oze c. (2016) evaporation induced 18o and 13c enrichment in lake systems: a global perspective on hydrologic balance effects. quaternary science reviews, 131, 365-379. ito e. (2001) application of stable isotope techniques to inorganic and biogenic carbonates. in tracking environmental change using lake sediments, vol. 2, physical and geochemical methods (ed. by last w.m., smol j.p.). kluwer, dordrecht, 351371. jones m.d., leng m.j., eastwood w.j., keen d.h., turney c.s.m. (2002) interpreting stable-isotope records from freshwater snail-shell carbonate: a holocene case study from lake golhisar, turkey. the holocene, 12, 629-634. jonsson c. e., andersson s., rosqvist g.c., leng m.j. (2010) reconstructing past atmospheric circulation changes using oxygen isotopes in lake sediments from sweden. climate of the past, 6, 49-62. leng m.j., lamb a.l., lamb h.f., telford r.j. (1999) palaeoclimatic implications of isotopic data from modern and early holocene shells of the freshwater snail melanoides tuberculata, from lakes in the ethiopian rift valley. journal of paleolimnology, 21, 97-106. leng m.j., marshall j.d. (2004) palaeoclimate interpretation of stable isotope data from lake sediment archives. quaternary science reviews, 23, 811831. leng m.j., lamb a.l., heaton t.h.e., marshall j.d., wolfe b., jones m.d., holmes j.a., arrowsmith c. (2006) isotopes in lake sediments. in: isotopes in palaeoenvironmental research (ed. by leng m.j.). springer, dordrecht, 147-184. leng m.j., baneschi i., zanchetta g., jex c.n., wagner b., vogel h. (2010) late quaternary palaeoenvironmental reconstruction from lakes ohrid and prespa (macedonia/albania border) using stable isotopes. biogeosciences, 7, 3109-3122. lézine a.-m., von grafenstein u., andersen n., belmecheri s., bordon a., caron j., cazet p., erlenkeuser h., fouache e., grenier c., huntsman-mapila p., hureau-mazaudier d., manelli d., mazaud a., robert c., sulpizio r., tiercelin j.-j., zanchetta g., zeqollari z. (2010) lake ohrid, albania, provides an exceptional multi -proxy record of environmental changes during the last glacial-interglacial cycle. palaeogeography, palaeoclimatology, palaeoecology, 287, 116-127. li h.-c., ku t.-l. (1997) δ13c-δ18o covariance as a paleohydrological indicator for closed-basin lakes. palaeogeography, palaeoclimatology, palaeoecology, 133, 69-80. lotter a.f., eicher u., birks h.j.b. siegenthaler u. (1992) late glacial climatic oscillations as recorded in swiss lake sediments. j. quat. sci., 7, 187-204. longinelli a., selmo e. (2003) isotopic composition of precipitation in italy: a first overall map. j. hydrol., 270, 75-88. longinelli a., (2008) a stable isotope study of the garda lake, northern italy: its hydrological balance. journal of hydrology, 360, 103-116. magny m. (1992) holocene lake-level fluctuations in jura and the northern subalpine ranges, france: regional pattern and climatic implications. boreas 21, 319-334. magny m. (1998) reconstruction of holocene lakelevel changes in the jura (france): methods and results. in: palaeohydrology as reflected in lakelevel changes as climatic evidence for holocene times: paläoklimaforschung (ed. by harrison s.p., frenzel b., huckried u., weiss m.). academy of sciences and literature in mainz, 25, 67-85. magny m. (2001) palaeohydrological changes as reflected by lake-level fluctuations in the swiss plateau, the jura mountains and the northern french pre-alps during the last glacial-holocene transition: a regional synthesis. global and planetary change, 30, 85-101. magny m. (2004) holocene climatic variability as reflected by mid-european lake-level fluctuations, and its probable impact on prehistoric human settlements. quaternary international, 113, 65-79. magny m., aalbersberg g., bégeot c., benoit-ruffaldi p., bossuet g., disnar j.-r., heiri o., laggoundefarge f., mazier f., millet l., peyron o., vannière b., walter-simonnet a.-v. (2006) environmental and climatic changes in the jura mountains (eastern france) during the late glacialholocene transition: a multi-proxy record from lake lautrey. quaternary science reviews, 25, 414-445. magny m., galop d., bellintani p., desmet m., didier j., haas j. n., martinelli n., pedrotti a., scandolari r., stock a., vanniere b. (2009) late-holocene climatic variability south of the alps as recorded by lake-level fluctuations at lake ledro, trentino, italy. holocene, 19, 575-589. magny m., joannin s., galop d., vanniere b., haas j. n., basseti m., bellintani p., scandolari r., desmet m. (2012) holocene palaeohydrological changes in the northern mediterranean borderlands as reflected by the lake-level record of lake ledro, northeastern italy. quaternary research, 77(3), 382-396. magny m. (2013) climatic and environmental changes reflected by lake-level fluctuations at gerzensee from 14,850 to 13,050 yr bp. palaeogeography, palaeoclimatology, palaeoecology, 391, 33-39. manella g., zanchetta g., regattieri e., perchiazzi n., drysdale r.n., giaccio b., leng m.j., wagner b. (2020) effects of organic removal techniques prior to carbonate stable isotope analysis of lacustrine marls: a case study from palaeo-lake fucino (central italy). rapid communications in mass spectrometry, 34,7, 15, e8623. mayer b., schwark l. (1999) a 15 000-year stable 105 stable isotopes of carbonate as tracers of lake hydrology isotope record from sediments of lake steisslingen, southwest germany. chemical geology, 161, 315-337. mckenzie j.a. (1985) carbon isotopes and productivity in the lacustrine and marine environment. in: chemical processes in lakes (ed. by stumm w.). john wiley & sons, london, 99-118. meyers p.a., teranes j.l. (2001) sediment organic matter. in: tracking environmental change using lake sediments. physical and geochemical methods, vol. 2 (ed. by last w.m., smol j.p.). kluver academic publishers, dordrecht, 239-270. mook w.g., bommerson j.c., staverman w.h. 1974 carbon isotope fractionation between dissolved bicarbonate and gaseous carbon dioxide. earth planet. sci. lett., 22, 169-176. natale m., bianchini g., colombani n., flaim g., marchina c., tassinari r. (2013) geochemical and isotopic investigation of lakes in the trento province (italy). environmental quality, 10, 11-22. perini m., camin f., corradini f., obertegger u., flaim g. (2009) use of δ18o in the interpretation of hydrological dynamics in lakes. journal of limnology, 68, 1-9. punning j.m., martma t., vaikmae r. (1984) light isotope variations in carbonate sediments and their palaeogeographical value. zeitschrift fur internationale mitteilungen, 84, 329-336. roberts n., jones m.d., benkaddour a., eastwood w.j., filippi m.l., frogley m.r., lamb h.f., leng m.j., reed j.m., stein. m., stevens l., valerogarcés b., zanchetta g. (2008) stable isotope records of late quaternary climate and hydrology from mediterranean lakes: the isomed synthesis. quat. sci. rev., 27, 2426-2441. rozanski k., araguas-araguas l., gonfiantini r. (1992) relation between long-term trends of oxygen-18 isotope composition of precipitation and climate. science, 258, 981-985. schwander j., eicher u., ammann b. (2000) oxygen isotopes at lake marl at gerzensee and leysin (switzerland), covering the younger dryas and two minor oscillations, and their correlation to grip ice core. palaeogeography, palaeoclimatology, palaeoecology, 159, 203-214. siegenthaler u., eicher u. (1986) stable oxygen and carbon isotope analyses. in handbook of holocene palaeoecology and palaeohydrology (ed. by berglund b.e.). john wiley and sons, london, 407-422. talbot m.r. (1990) a review of the palaeohydrological interpretation of carbon and oxygen isotopic ratios in primary lacustrine carbonates. chemical geology (isotope geoscience section), 80, 261-279. teranes j.l., mckenzie j.a., bernasconi s.m., lotter a.f., sturm m. (1999) a study of oxygen isotopic fractionation during bio-induced calcite precipitation in eutrophic baldeggersee, switzerland. geochim. cosmochim. acta, 63, 1981-1989. teranes j.l., bernasconi s.m. (2005) factors controlling δ13c values of sedimentary carbon in hypertrophic baldeggersee, switzerland, and implications for interpreting isotope excursions in lake sedimentary records. limnol. oceanogr., 50, 914922. von grafenstein u., erlenkeuser h., kleinmann a., muller j., trimborn p. (1994) high-frequency climatic oscillations as revealed by oxygen isotope records of benthic organisms (ammersee, southern germany). journal of paleolimnology, 11, 349357. von grafenstein u., erlenkeuser h., brauer a., jouzel j., johnsen s.j. (1999) a mideuropean decadal isotope-climate record from 15,500 to 5000 years bp. science, 284(5420), 1654-1657. von grafenstein u., eicher u., erlenkeuser h., ruch p., schwander j., ammann b. (2000) isotope signature of the younger dryas and two minor oscillations at gerzensee (switzerland): palaeoclimatic and palaeolimnologic interpretation based on bulk and biogenic carbonates. palaeogeography, palaeoclimatology, palaeoecology, 159, 215-229. whittington g., edwards k.j., zanchetta g., keen d.h., bunting j., fallick a.e., bryant c.l. (2015) lateglacial and early holocene climates of the atlantic margins of europe: stable isotope, mollusk and pollen records from orkney, scotland. quaternary science reviews, 122, 112-130. zanchetta g., baneschi i., francke a., boschi c., regattieri e., wagner, b., lacey j.h., leng m.j., vogel h., sadori l. (2018) evidence for carbon cycling in a large freshwater lake in the balkans over the last 0.5 million years using the isotopic composition of bulk organic matter. quaternary science reviews, 202, 154-165. zanchetta g., bonadonna f.p., leone g. (1999) a 37meter record of paleoclimatological events from stable isotope data on molluscs in valle di castiglione, near rome, italy. quaternary research, 52, 293-299. zanchetta g., van welden a., baneschi i., drysdale r.n., sadori l., roberts n., giardini m., beck c., pascucci v. (2012) multiproxy record for the last 4500 years from lake shkodra (albania/ montenegro). journal of quaternary science, 27, 780-789. 106 baneschi i. et al. ms. received: july 13, 2020 revised: october 31, 2020 accepted: november 1, 2020 available online: november 30, 2020 amq32(2) 93-100 galli pallone.pub reviewing the intensity distribution of the 1933 earthquake (maiella, central italy). clues on the seismogenic fault paolo galli 1, francesca pallone 2 1 dipartimento della protezione civile, roma, italy. 2 anas spa roma, italy. corresponding author: p. galli <paolo.galli@protezionecivile.it> abstract: here we deal with the study of a strong earthquake occurred in 1933 in the mountainous area of the maiella massif (abruzzi, central italian apennines). we carried out original archive researches that allowed to evaluate a novel macroseismic field, and new parameters for this earthquake (io=imax 9 mcs; mw 6.01±0.07; epicentral coordinate: n42.050°, e14.191°). then we compared its highest intensity distribution of this event with the known, active normal fault of the region, finding any possible matching with none of these. therefore, considering the subsurface tectonic interpretation provided by the recent scientific literature, we hypothesize that a possible seismogenic structure for both the 1933, and the catastrophic 1706 event (mw 6.9; roughly same 1933 epicenter) is the blind backthrust that developed during early-middle pleistocene in the footwall of the maiella anticline. keywords: 1933 earthquake; macroseismology; compressive tectonics; maiella massif. available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 32 (2), 2019, 93 100 1. introduction at dawn of september 26 1933 (4:33 local time, 3:33 gmt) a strong earthquake struck the southeastern area of the maiella massif (abruzzo, central italian apennines), damaging heavily several villages, and causing extensive destruction in few localities, as in lama dei peligni, taranta peligna, and civitella messer raimondo. the mainshock was closely preceded by two foreshocks that alarming the inhabitants of the region prompted most of them to escape from their houses, and to pass the night outsides their fragile, old stonemasonry houses. therefore, in spite of the large amount of collapses and destructions (fig. 1), this yielded a relatively little death toll (12 casualties), and less than two hundred injured. two centuries before, in 1706, the same region was hit by one of the strongest and deathful earthquake in the italian history (io 10.5; mw=6.8. more than 2200 victims). interestingly, the two events share a similar mesoseismic area, the older presenting much higher site intensities. although the seismogenic sources of both earthquakes have remained unknown so far, giving the similarity of the respective highest intensity datapoints distribution (hidd), it is possible that they could share segments of the same fault system. in order to enhance the knowledge concerning the highest intensity distribution (is≥ 7 mcs) of the 1933 earthquake, and thus indirectly enlighten the rough location of its causative fault (and hopefully the 1706 one), here we carried out a reappraisal of all the data quoted or reported in the italian seismic databases (e.g., dbmi15, 2016; cfti5med, 2018; asmi, 2019). as the previous studies were mainly based upon the information listed in few newspapers and on the works of cavasino (1935a; 1935b) and margottini et al. (1992), we also performed farther archive and library researches that allowed us to collect new, original and reliable data. 2. materials and methods with the aim of completing the information concerning the damage within each municipality, firstly we carried out an extensive reading of contemporary periodical publications at the central national library of rome, where we collected useful information reported inside 15 italian newspapers (i.e., il mattino; il giornale d’italia; la nazione; il popolo d’italia; il popolo di roma; il regime fascista; il corriere della sera; la tribuna; l’osservatore romano; la gazzetta del popolo; roma; l’avvenire d’italia; il lavoro fascista; il tevere; il messaggero), for a total of 58 articles specifically dealing with the earthquake. we also found generic information on french papers at the national library of france (paris), as in le journal, le populaire and l'ouestéclair. although newspapers contain first-hand news and accounts, we have found that the information were often qualitative, reporting just the number of victims in each village, the number of injured people, and a rough https://doi.org/10.26382/amq.2019.05 94 galli p. & pallone f. framework of the destroyed houses and of those still inhabitable. it is worth noting that, similarly to what happened three years before after the so-called vulture earthquake (july 23, 1930; mw 6.7, southern italian apennines. see castenetto & sebastiano, 2002), italian press-reporters widely emphasized the prompt rescue and assistance provided to the inhabitants by the fascist government and by the local authorities. and then, as in 1930, in spite of the severe damage scenario, the whole national press suddenly minimized the event, which soon disappeared from all the newspapers pages. the spirit of the times is well condensed in a telegram, sent on october 1 by the italian prime minister to the minister of the public works, which just says: "go for a ride in the earthquake zone mussolini", clearly implying to minimize anything (fig. 2). we also made researches inside the former archive of the civil protection department where besides a large amount of telegrams sent by the prefects to the interior ministry, mostly containing the early news on the earthquake effects we have found an enormous quantity of documents attesting the requests of economical support sent by each single citizens, their associated technical expertise, and, sometime, the answers provided by the authorities in the following months or years. most of this information supported the evaluation of the level of damage existing in each locality, providing also complementary data in places not fully covered by other sources. nevertheless, one of the most important and novel data in our study derives from the huge mass of information collected by ridolfi (2005), who was previously ignored in any seismic compilation. her work is entirely devoted to the effects that the 1933 earthquake had on the region surrounding the maiella massif (abruzzo side). data were mainly collected in archives and libraries, such as: central state archive; state archive of chieti; state archive of pescara; historical archive of banco di napoli; historical archive of the municipality of avezzano; archive of the superintendency of public works; library of the chamber of deputies; library of the ministry of agriculture; library of the bank of italy; archive of the chamber of commerce, industry, agriculture and crafts of chieti. by ordering and systematizing all of these huge amount of valuable information, it was possible to precisely estimate the number of building affected by each specific damage level (e.g., light, moderate and severe damage, destruction, collapse), and thus evaluate the intensity degree according to the mercalli-cancanisieberg (mcs) scale, published just three years before by sieberg (1930). as explained in the following, to do fig. 1 view of the collapse of some poor stone-masonry houses in a village east of the maiella massif (left; l’illustrazione italiana, 1933) and in lama dei peligni (right; photo keystone-france/abruzzes/gettyimages). fig. 2 the telegram sent by benito mussolini to araldo di crollalanza, minister of the public works: “go for a ride in the earthquake zone”. it is quite clear the intent to minimize the effects of the earthquake. (civil protection department archive). 95 reviewing the intensity distribution of the 1933 earthquake (maiella, central italy) this, we analytically applied the method suggested by molin (2009), that considers the percentage of each damage level (1-5) as representative of every mcs degree (from 5 to 11 mcs). 3. results first of all, for each singe locality, we obtained the percentage of buildings affected by the different levels of damage that we mainly deduced from the analytical data contained in the ridolfi’s (2005) work, filling the gaps with information collected from newspapers, telegrams and other primary sources found in the archive of the civil protection department. then we transformed these percentages in mcs degree, considering damage levels 2-3 (i.e., from moderate to severe damage, not distinguishable singularly in most of the documentary materials), 4 (destruction, and/or irreparable damage), and 5 (collapse) in the percentage progression proposed by molin (2009). this allowed us to obtain robust intensities estimates (see tab. 1) that generally move away from those reported in dbmi15 (2016) and cfti5med (2018) by just 0.5-1 degrees or, exceptionally, 1.5 degree. it is worth noting that in the previous studies many intensity datapoints were derived uncritically from a crude list published by cavasino (1935b), who likely estimated the mcs intensities on the basis of the fresh information gathered brevi manu from the local authorities of the time, leaving any written description of the effects felt by these localities. therefore, in order to complete the dataset of our datapoints that mainly lacks the lowermost intensities we also decided to consider those published by cavasino (1935b). however, before including tout court these intensities, we compared analytically our intensities with those in cavasino (1935b), calculating thus a linear regression between the two datasets. then, by applying the resulting equation, we obtained a is value for the lacking intensities consistent with our macroseismic evaluation (tab. 1). the new areal distribution of the highest intensity datapoints (fig. 3, left) provides a slightly different image of the mesoseismic area then before, although it remains strongly focused on the maiella massif, with a macroseismic epicenter (black rhomb in fig. 3) falling close to lama dei peligni. this epicenter falls ~7 km away from that calculated by palombo (2010) by using the time arrivals of p and s-wave phases reported in the iss bulletins, and coupled with the nonlinloc code (lomax et al., 2000), with this point assumed as the maximum likelihood instrumental location for the 1933 earthquake. the epicentral intensity can be evaluated around io 9 mcs, as in cpti15 (2016) and cft5med (2018), with coordinates of n42.050°, e14.191°. in turn, the equivalent magnitude that we have calculated by applying boxer4 algorithm (gasperini et al., 1999) is mw 6.01±0.07 (5.9±0.07 in cpti15; 6.05±0.1 in cft5med; 6.4±0.3 in palombo, 2010), with a source length of 13 km striking n30°±13°, that is perpendicular and external to all the main extensional, nw-se active fault of central apennines (fig. 3). last but not least, we have found a novel and interesting information concerning surface effects produced by the earthquake. this regards the damage suffered by a tunnel of the sulmona-roccaraso line, that caused the stop of the trains between the stations of campo di giove and palena (green circle in fig. 4) fig. 3 left, distribution of the highest intensities distribution re-evaluated here for the 1933 earthquake (yellow circles proportional to is 59 mcs). background colors suggest the areal distribution of the intensities (see mcs scale; kriging interpolation); black rhomb is the macroseismic epicenter calculated through boxer4 algorithm (gasperini et al., 1999); red rhomb is the instrumental epicenter (palombo, 2010). right, same image for the 1706 earthquake (unpublished data of the authors); black rhomb is the 1706 macroseismic epicenter (boxer4 algorithm); red rhomb is again the 1933 instrumental epicenter. blue lines in both panels are the normal active faults of the region, all sw dipping (mod. from galli & peronace, 2014). note that intensities span between 7-11 mcs in the 1706 panel vs 5-9 mcs in the 1933 panel. 96 tab. 1 mcs intensities (is) related to the 26 september 1933 mainshock. lon and lat are wgs84 geographic coordinate of centroid of locality. galli p. & pallone f. 4. discussion and conclusions observing the left panel of fig. 3, we notice that the highest site intensities of the 1933 earthquake fall at the base of the eastern edge of the maiella massif (i.e., taranta dei peligni, lama dei peligni, and civitella messer raimondo, all with is 9 mcs; see tab. 1), decreasing then progressively eastward and northward. intensities 7-8 mcs also characterize the eastern flank of the morrone ridge, with a peak of is 8.5 mcs in salle vecchia, where diffuse landsliding, more than shaking, contributed to the severe damage framework. obviously, the lack of localities in the mountainous zones of the 97 maiella massif alters the perception of the real shaking distribution, although it is clear that the strongest ground acceleration is confined in the adriatic side of the morrone-maiella ridge. definitively, this means that none of the ~west dipping active normal faults of the region (i.e., all the blue lines in fig. 3 4) can be the source of this earthquake. indeed, the 1933 hidd is fully concentrated in the footwall of these structures, in contrast to all the earthquakes of the italian apennines, the hidd of which fall always in the hangingwall of their causative faults (e.g. in galli & galadini, 1999; galli et al., 2009; 2017). as far as the possible 1933 and 1706 sources are fig. 4 a, shaded relief map of central apennines with the major historical seismicity (red circles, mw>5.0; yellow circles, well-dated mw>6.5 paleoseismological events; galli et al., 2015; 2016) and the main, active normal faults (blue lines; mod. from galli and peronace, 2014). mfs, mount morrone fault system; cf, caramanico fault. red rhomb is the 1933 instrumental epicenter (palombo, 2010). red triangles-dashed lines suggest the bounding thrust of the casoli-bomba (c-b) pop-up and of the buried backthrust below the maiella anticline footwall (mafb; inferred northward mimicking the caramanico fault path; ghisetti and vezzani, 2002; calamita et al., 2009). dotted line is the segment of crop-11 line shown in panel b; green circle indicates the area where the railway tunnel was damaged by the 1933 earthquake. b, part of crop-11 line interpreted by patacca et al. (2008). 1, pleistocene marine deposits of the foredeep basin; 2, pliocene marine deposits conformably overlying the apulia carbonates; 3, mount genzana unit; 4, mount morrone-porrara unit; 5, upper cretaceous -pliocene mount queglia unit; 6, molise units; 7, lower pliocene flysch of maiella unit; 8, mesozoic-tertiary carbonates of maiella unit; 9, mesozoic-tertiary carbonates of apulia platform; 10, paleozoic-triassic deposits. reviewing the intensity distribution of the 1933 earthquake (maiella, central italy) concerned, some authors associated these earthquakes to two consecutive ruptures of patches of a so-called, sw-dipping abruzzo citeriore basal thrust (lavecchia & de nardis, 2010). however, the existence of this basal thrust is denied by the interpretation provided by patacca et al. (2008) of the crop 11 deep reflection seismic profile, where the entire pliocene maiella rampanticline overlies a popup structure in the mesozoictertiary carbonates of the apulia platform. this popup is instead related to an important e-dipping backthrust (mafb in fig. 4; patacca et al., 2008), which likely controlled also the growth of the neighboring casoli-bomba high (c-b pop-up in fig. 4). according to patacca et al. (2008), the existence, timing and importance of this blind structure, which developed in the footwall of the maiella anticline, is testified also by the impressive uplift of the maiella anticline just over the backthrust hanging-wall. the uplift started in the early pleistocene, rising the top of the maiella carbonate massif at a rate of some centimeters per year (i.e., vertical component of the active-thrust slip vector), from few hundred meters a.s.l. to the present elevation (~2800 m), or more. another evidence for this is the > 3500 m vertical throw accommodated by the caramanico normal fault (cf in fig. 4b; see also ghisetti & vezzani, 2002), which could represent a gravity collapse feature developed in the roof of the passively growing maiella tectonic edifice (patacca et al., 2008). if this interpretation is correct, as the hidd of the 1706 and 1933 earthquakes mainly fall in the broad hanging-wall of this backthrust, one could hypothesize that both events were sourced by a residual activity of this quaternary structure that, tentatively, could also trigger the passive motion of the caramanico fault. likewise, also other earthquakes occurred in the farther, backthrust hanging-wall, as the 1881 one (mw 5.4; fig. 4a), could have been sourced by structures rooted at depth to the sole thrust, for instance those bounding the casoli-bomba high (fig. 4b). nevertheless, whereas the largest slip of the backthrust occurred during the late emilian-early sicilian (patacca et al., 2008), today we have not geological evidence for such a persisting activity in its hangingwall, with the exception of some morphotectonic indication suggesting post-middle pleistocene anticline growing (pomposo & pizzi, 2009). even the geodetic data published so far (d’agostino et al., 2011; d’agostino, 2014; angelica et al. 2013; devoti et al., 2011; galvani et al., 2012) show that the outer morrone-maiella region is not experiencing ne-sw compression, as gps vectors located westward and eastward of these massifs roughly show the same ne velocity. moreover, there are neither focal mechanisms, nor borehole breakouts in the whole region supporting or ruling out ongoing compression (e.g. in mariucci & montone, 2018). actually, palombo (2010) tried to calculate the 1933 focal mechanism from eighteen retrieved paperseismograms, although only eight had useful p wave first motion. amongst the possible solutions, palombo (2010) evidenced two groups with different kinematics; one with average nw-se trend associate to a ne-sw tensional axis (i.e., transtensive ne-sw faults), and the other compatible with a ne-sw compressive field (nnessw, transpressive, right strike-slip fault, i.e., similar to the strike of the source resulting from the boxer4 algorithm). honestly, at the moment, we can conclude that the seismogenic sources of these two frightful earthquake are still uncertain. we can surely exclude that they were generated by any of the known, active normal faults mapped in fig. 4, and least of all by the mount morrone fault system which bounds the eastern side of the sulmona basin (mfs in fig. 4a). as aforementioned, the hidd of the 1706 and 1933 events fall in the footwall of all these faults, while the mount morrone fault, although very close to both epicenters, and partly running inside the 1706 hidd, sourced its last earthquake in the far 2nd century ad, as definitely demonstrated by recent paleoseismic studied (galli et al., 2015). concluding, our working hypothesis which makes no claims to being conclusive is that the source of both 1706 and 1933 events might be the blind backthrust in the footwall of the maiella anticline, the geometry of which matches the hidd of both events. in this case, it is also possible that the caramanico fault might move passively, inducing some surface rupture, as suggested by the damage in the railway tunnel in 1933. all this implies the existence of active, ne-sw compression just east to the extensional belt highlighted by the active faults shown in fig. 4b, which is not (yet?) adequately supported by either geological or instrumental data. acknowledgments we are grateful to n. ridolfi who share with us the results of her long work. we thank d. molin for the useful discussion, and the personal of the archive of the dipartimento della protezione civile nazionale of italy who supported our research. p. messina and e. peronace provided useful criticism in reviewing the manuscript. the views and conclusions contained here are those of the authors and should not be interpreted as necessarily representing official policies, either expressed or implied, of the italian government. references asmi (2019) archivio storico macrosismico italiano, rovida a., locati m., antonucci a., camassi r. (eds.), istituto nazionale di geofisica e vulcanologia, https://emidius.mi.ingv.it/asmi/ calamita f., esestime p., paltrinieri w., scisciani v., tavarnelli e. (2009) structural inheritance of pre and syn-orogenic normal faults on the arcuate geometry of pliocene-quaternary thrusts: examples from the central and southern apennine chain, ital.j.geosci, 128, 381-394. castenetto s., sebastiano m. (2002) il regime fascista e le calamità naturali, in: il terremoto del vulture del 23 luglio 1930, roma, 49-58. cavasino a. (1935a) i terremoti d’italia nel trentacinquennio 1899-1933, in "memorie del regio ufficio centrale di meteorologia e geofisica", s. iii, appendice al vol.4. roma 1935. cavasino a. (1935b) bollettino sismico anno 1933, fasc.2 (macrosismi), regio ufficio centrale di meteorologia e geofisica. roma 1935. 98 galli p. & pallone f. central italy in 1400 years evidenced by new palaeoseismic results, terra nova, 28, 146-154. galvani a., anzidei m., devoti r., esposito a., pietrantonio g., pisani a.r., riguzzi f., serpelloni e. (2012) the interseismic velocity field of the central apennines from a dense gps network, annals of geophysics, 55, doi: 10.4401/ag-5634. gasperini p., bernardini f., valensise g., boschi e. (1999) defining seismogenic sources from historical felt reports, bull. seism soc. am., 89, 94-110. ghisetti f., vezzani l. (2002). normal faulting, extension and uplift in the outer thrust belt of the central apennines (italy): role of the caramanico fault, basin research, 14, 225-236. lavecchia g., de nardis r. (2010) seismogenic sources of major earthquakes of the maiella area (central italy): constraints from macroseimic field simulations and regional seimotectonics. ur 4.01, dpc-ingv project 2007-2009. lomax a., virieux j., volant p. and berge c (2000) probabilistic earthquake location in 3d and layered models: introduction of a metropolis-gibbs method and comparison with linear locations, in advances in seismic event location thurber, c.h., and n. rabinowitz (eds.), kluwer, amsterdam, 101-134. margottini c., puglisi c., sericola a. (1992) il terremoto del 1933 nell'area della maiella (abruzzo-italia centrale). enea, rapporto interno, roma, 24 pp. mariucci m.t., montone p. (2018) ipsi 1.2, database of italian present-day stress indicators, istituto nazionale di geofisica e vulcanologia (ingv). doi: 10.6092/ingv.it-ipsi.1.2 molin d. (2009) rilievo macrosismico in emergenza. rapporto interno dipartimento della protezione civile; ufficio iii valutazione, prevenzione e mitigazione del rischio sismico, internal report. patacca e., p. scandone e. di luzio g. p. cavinato and m. parotto (2008) structural architecture of the central apennines: interpretation of the crop 11 seismic profile from the adriatic coast to the orographic divide, tectonics, 27, tc3006. doi:10.1029/2005tc001917 palombo b. (2010) information on source parameters of meaningful italian historical earthquakes estimated within the sismos project framework, task b of ur 4.02, dpc-ingv project 2007-2009. pomposo g., pizzi a. (2009) evidenze di tettonica recente ed attiva nel settore sepolto dell’appennino abruzzese, rendiconti della società geologica italiana, 5, 176-178. ridolfi n. (2005) economia di una catastrofe: il terremoto della majella in epoca fascista. collana del dipartimento di economia e storia del territorio. università "g. d'annunzio" di chieti-pescara f. angeli. sieberg a. (1930) geologie der erdbeben. handboch der geophysic, 2, 4, 552-554 [tabb. 100, 101, 102, 103], berlin. newspapers corriere della sera, 27-28-29-30/09/1933, milano 1933. il giornale d’italia, 27-28/09/1933; 5-6/10/1933, roma cfti5med (2018) catalogo dei forti terremoti in italia (461 a.c.-1997) e nell’area mediterranea (760 a.c. -1500), e. guidoboni, g. ferrari, d. mariotti, a. comastri, g. tarabusi, g. sgattoni, g. valensise (eds.), istituto nazionale di geofisica e vulcanologia. http://storing.ingv.it/cfti/cfti5/. doi: 10.6092/ingv.it-cfti5 cpti15 (2016) the 2015 version of the parametric catalogue of italian earthquakes, rovida a., locati m., camassi r., lolli b., gasperini p. (eds), istituto nazionale di geofisica e vulcanologia. https:// emidius.mi.ingv.it/cpti15-dbmi15/. doi: 10.6092/ingv.it-cpti15 d’agostino n. (2014) complete seismic release of tectonic strain and earthquake recurrence in the apennines (italy), geophys. res. lett. 41. doi: 10.1002/2014gl059230 d'agostino n., mantenuto s., d'anastasio e., giuliani r., mattone m., calcaterra s., gambino p., bonci l. (2011) evidence for localized active extension in the central apennines (italy) from global positioning system observations. geology, 39, 291-294. doi:10.1130/g31796.1 dbmi15 (2016) the 2015 version of the italian macroseismic database, locati, m., camassi r., rovida a., ercolani e., bernardini f., castelli v., caracciolo c.h., tertulliani a., rossi a., azzaro r., d’amico s., conte s., rocchetti e. (eds.), istituto nazionale di geofisica e vulcanologia. https:// emidius.mi.ingv.it/dbmi04/. doi: 10.6092/ingv.it-dbmi15 devoti r., esposito a., pietrantonio g., pisani a.r., riguzzi f. (2011) evidence of large scale deformation patterns from gps data in the italian subduction boundary. earth and planetary science letters 311 (3-4), 1-12. doi: 10.1016/j.epsl.2011.09.034 galli p., galadini f. (1999) seismotectonic framework of the 1997-98 umbria-marche (central italy) earthquakes. seismological res. letters, 70, 4, 404414. galli p., camassi r., azzaro r., bernardini f., castenetto s., molin d., peronace e., rossi a., vecchi m., tertulliani a. (2009) il terremoto aquilano del 6 aprile 2009: rilievo macrosismico, effetti di superficie ed implicazioni sismotettoniche. il quaternario, 22, 235-246. galli p., castenetto s., peronace e. (2017) the macroseismic intensity distribution of the 30 october 2016 earthquake in central italy (mw 6.6): seismotectonic implications. tectonics, 36. 1-13. doi: 10.1002/2017tc00458. galli p., peronace e. (2014) new paleoseismic data from the irpinia fault. a different seismogenic perspective for southern apennines (italy), earthscience reviews, 136, 175-201. galli p., giaccio b., peronace e., messina p. (2015) holocene paleoearthquakes and early-late pleistocene slip-rate on the sulmona fault (central apeninnes, italy), bull. seism. soc. am., 105(1), 113. galli p., giaccio b., messina p., peronace e. (2016) three magnitude 7 earthquakes on a single fault in 99 reviewing the intensity distribution of the 1933 earthquake (maiella, central italy) 100 1933. il lavoro fascista, 2729/09/1933; 1/10/1933, milano 1933. il mattino, 27-29/09/1933; 5/10/1933, napoli 1933. il messaggero, 27-28-29/09/1933, roma 1933. il popolo d’italia, 27-28/09/1933; 1-4/10/1933, milano 1933. il popolo di roma, 27-29/09/1933, roma 1933. il regime fascista, 27-28/09/1933; 4/11/1933, cremona 1933. il tevere, 27-29-30/09/1933; 4-5-26/10/1933; 6-24/11/ 1933, roma 1933. l’avvenire d’italia , 27/09/1933; 1/10/1933; 24/11/1933, bologna 1933. l’osservatore romano, 27-28-29/09/1933; 24/11/1933, città del vaticano 1933. la gazzetta del popolo, 27-28-29-30/09/1933, torino 1933 la nazione, 27-29/09/1933, firenze 1933. la tribuna, 27-28-29-30/09/1933; 24/11/1933, roma 1933. roma, 27-28-30/09/1933; 1-3-24/11/1933, roma 1933. le journal, 27/09/1933, paris, 1933. le populaire, 27/09/1933, paris, 1933. l'ouest-éclair, 27-28/09/1933, paris, 1933. galli p. & pallone f. ms. received: february 19, 2019 final text received: march 20, 2019 imp.alberto& proposta di classificazione delle “pseudocarniole” dell’alta valle di susa (alpi occidentali) walter alberto1, francesco carraro1, marco giardino1 & davide tiranti2 1dipartimento di scienze della terra dell’università di torino. via valperga-caluso, 35 10125 torino 2arpa piemonte area previsione e monitoraggio ambientale. c.so unione sovietica, 216 10134 torino riassunto: w. alberto, f. carraro, m. giardino, d. tiranti, proposta di classificazione delle “pseudocarniole” dell’alta valle di susa (alpi occidentali). (it issn 0394-3356, 2005). nelle alpi occidentali, tra le rocce indicate in letteratura come evaporiti triassiche sono presenti litofacies che mostrano marcate differenze di tessitura, composizione, geometria, posizione stratigrafica e strutturale evidenziando quindi probabili differenze di genesi ed età. tali rocce, definite in via provvisoria “pseudocarniole” a causa dell’apparente convergenza di facies con le carniole autentiche, sono l’oggetto del presente studio. la ricerca si è sviluppata principalmente sul terreno ed è stata successivamente approfondita avvalendosi di microanalisi (catodoluminescenza e sem). in base ai caratteri litologici, tessiturali, strutturali, ai rapporti con altre rocce, alle relazioni con la deformazione, il carsismo e l’alterazione viene proposta una classificazione distinta in diverse facies: pseudocarniole “autoclastiche” (termine provvisorio): brecce monogeniche dolomitiche o calcaree, in cui è ancora ben distinguibile l’originaria stratificazione della roccia d’origine; pseudocarniole residuali: brecce monogeniche dolomitiche o calcaree, caotiche e talvolta ricche di matrice; pseudocarniole detritiche: brecce e conglomerati carbonatici poligenici; pseudocarniole incrostanti: crostoni superficiali di cemento carbonatico; pseudocarniole tettoniche: brecce carbonatiche caratterizzate da tessiture variabili ma localizzate in corrispondenza di contatti tettonici. in base ai dati emersi dalla recente letteratura e dai risultati delle ricerche condotte nell’ambito del presente studio, la genesi delle pseudocarniole risulta legata all’interazione e alla sovrapposizione di numerosi processi tra i quali il meccanismo-guida è rappresentato dalla dissoluzione di rocce carbonatiche e gessoso-anidritiche indotta dalla circolazione di fluidi. la diffusa dissoluzione ha instaurato una situazione di generale instabilità dell’ammasso roccioso con conseguente assestamento gravitativo i cui riflessi superficiali hanno attivato processi di deformazione gravitativa di versante. alla dissoluzione si accompagnano generalmente altri processi (tettonica distensiva e trascorrente, tettonica gravitativa, idratazione delle anidriti, carsismo, ecc.) che possono agire in momenti diversi e con intensità molto variabile. ne risultano quindi diversi tipi di pseudocarniole che costituiscono corpi di dimensioni, geometria, associazioni assai variabili. infine i dati cronologici indiretti ricavati da analisi polliniche e da osservazioni dei rapporti intercorrenti tra le pseudocarniole e gli altri termini geologico-strutturali (es. assenza di evidenze del coinvolgimento di tali rocce da parte della deformazione e del metamorfismo alpino), concorrono nell’indicare che il processo evolutivo di tali rocce appare svolgersi in un intervallo di tempo in genere ampio, diverso a seconda delle facies considerate ed inquadrabile tra un limite massimo rappresentato dal post-oligocene ed il presente, in cui la rielaborazione carsica pleistocenica rappresenta molto spesso il processo maggiormente responsabile dell’attuale aspetto. abstract: w. alberto, f. carraro, m. giardino, d. tiranti, classification proposal of the “pseudocarniole” of high susa valley (western alps). (it issn 0394-3356, 2005). in the italian, french, swiss and german alpine geological literature, among the lithological terms used to define triassic formations, it is possible to find a group of rocks called "carniole", "cornieules", "cargneules", "rauhwacken". normally, they are interpreted as evaporitic triassic rocks (further on described as "true" carniole) but they can also be described as rocks similar to the evaporites with some differences in their texture, composition, geometry, stratigraphical and structural distribution as well as in their genesis and age (such lithofacies are provisionally known as "pseudocarniole"). particularly, in the sheets of the geological map of italy, 1:100.000 in scale where the upper susa valley is included (map 66 "cesana torinese"), the above rocks are all interpreted as "triassic evaporites". the main object of the present paper consisted in the acquisition of more data concerning the different classification problems for the pseudocarnioles. throughout a detailed survey and a precise interpretation, integrated by microanalysis, it was possible to elaborate a genetic model for the pseudocarnioles of the upper susa valley. the study has been formulated modularly so that it could be used in other study-fields. the data collection was mainly developed on the field and subsequently studied by thin section microanalysis, some of which were observed by cathode-luminescence (cl) and by scanning electron microscope (sem). these close examinations have permitted to specify the relationships among the different types of pseudocarnioles depending on the relationships between the different carbonatic cements found in them. it has also allowed the definition of the fragments nature, the reconstruction of the sedimentary processes that have determined or conditioned their origin, as well as the influences of the deformation processes on their texture and structure. the field data collection, their modular and normalized fill-in forms (information cards) and the analysis of some pre-established situations has led to the individualization of five principal facies to which correspond many other genetic mechanisms: “autoclastic pseudocarniole”, constituted by monogenetic breccias (calcareous or dolomitic); the fragments are always angular, and do not show any kind of rotation signs, they have varying dimensions from less than a centimetre to more than some meters and a chaotic distribution. sometimes they preserve stratification traces, more or less disguised by the fractures, inherited by the original "protolite". the possible mud matrix is locally associated to more generations of cement. in some cases the spaces between the fragments are empty. residual pseudocarniole: they are constituted by monogenetic breccias (calcareous or dolomitic), more rarely polygenetic, with angular not selected fragments always with matrix. locally they show a weak stratification. detrital pseudocarniole: constituted both by poligenetic breccias, with varying dimensions, matrix always present and clastor matrix-supported, or by thin sand-silt sediments. depending on the texture variability, it is possible to make a further subdivision in sub-facies with different genetic mechanisms (detrital sub-facies without transport, detrital sub-facies with transport, this last one distinguished in detrital sub-facies by channelled water transport, detrital sub-facies by stream water transport, detrital sub-facies by il quaternario italian journal of quaternary sciences 18(2), 2005 187-200 188 w. alberto et al. 1. introduzione il termine “pseudocarniola” viene utilizzato in questo lavoro per indicare quelle rocce della catena alpina occidentale le quali, benché note in letteratura come “evaporiti triassiche” per la natura carbonatica e l’aspetto vacuolare, mostrano di inglobare clasti a metamorfismo alpino e di non essere interessate dalla deformazione “duttile” alpina: per questi motivi viene loro attribuita dagli autori una genesi ed un’età differente dalle “vere” carniole. lo scopo delle ricerche delle quali il presente lavoro rende conto è consistito nell’elaborazione di una classificazione delle “pseudocarniole” della valle di susa. per mezzo di un rilevamento di dettaglio ed un’interpretazione tramite una procedura, integrata da microanalisi, messa a punto nel corso del lavoro, è stato inoltre elaborato un modello genetico. nell’ambiente scientifico alpino, da alcuni decenni, si osserva un certo interesse verso questo tipo di rocce; dall’analisi della letteratura sull’argomento si evince come non vi sia però omogeneità nella terminologia (tra i termini più frequentemente utilizzati, si citano: “carniole”, “cornieules”, “cargneules”, “rauhwacken”) e nelle definizioni delle facies. per questo motivo si è preferito utilizzare il termine “pseudocarniola” a indicare tutto l’insieme di rocce che mostra al suo interno forti convergenze di aspetto e per il quale può essere data solamente una definizione di carattere generale: brecce e conglomerati carbonatici, di aspetto vacuolare e di colore da grigio, a giallo a ocra. molto schematicamente è possibile riunire i diversi modelli interpretativi di queste rocce in tre gruppi principali: origine sedimentaria (di età terziaria recente in quanto discordanti su strutture di tettonica terziaria e perché rimaneggiano elementi eocenici superiori o oligocenici) in grandjacquet & haccard, 1973, 1975; patacca et alii, 1973; federici & raggi, 1974); origine direttamente tettonica (ad es. cataclasiti) o in relazione con questa (prodotti di rielaborazione di tettoniti) (es. leine, 1968; 1971; masson, 1972; fudral, 1998); origine per alterazione o per processi estranei e successivi alla sedimentazione e alla tettonica (con genesi anche recente, in relazione all’alterna comparsa e scomparsa delle masse glaciali, ad esempio in debenedetti & turi, 1975). altri lavori inoltre si pongono in posizione intermedia, indicando per le pseudocarniole un’origine “mista” sedimentaria e tettonica (wiesender, 1971), oppure tettonica e per alterazione (müller, 1982; richards & vearnecombe, 1984) di età anche molto recente in quanto sovrapposta alla breccificazione tettonica. più di recente si sono andate affermando ipotesi in cui viene sottolineata la complessità e la varietà dei meccanismi genetici, dipendenti anche da fattori locali, il cui risultato sono numerosi tipi di pseudocarniole differenti per tessitura, struttura, geometria del corpo e rapporti con le rocce circostanti (carraro & martinotti 1993; giardino, 1995; fusetti, 2002; polino et alii., 2002). i meccanismi in grado di trasformare le rocce carbonatiche di partenza in pseudocarniole comprendono la dissoluzione (che svolge il ruolo principale e di cui quella carsica sarebbe la più evidente), la dedolomitizzazione, la precipitazione di cementi calcitici e dolomitici. nei confronti della dissoluzione, la tettonica è considerata come fattore predisponente (bruckner, 1941; ellenberger, 1954; warrack, 1974; debenedetti & turi, 1975; debelmas et alii, 1980) o come evento successivo (jeanbourquin, 1986, 1988). nelle alpi occidentali le pseudocarniole costituiscono numerosi ammassi, di volume da metrico a ettometrico, tipicamente associati a successioni triassiche stream water from fill-in epigeous karst cavities). incrustation pseudocarniole: composed by abundant quantities of carbonatic poligenetic cement, polychrome, with small angular fragments of a different nature; typical vacuolar aspect. “tectonic” pseudocarniole: characteristic varying textures, but all with tabular geometry and distribution along movement planes and shear zones. inside it is possible to recognize some deformation signs (boudin lithons, movement surfaces) as well as non-deformed portions. among the different processes of interaction and/or overlap of the pseudocarnioles, some indicate a predisposing role, some a determinant one and many others a conditioning one. the main formation mechanism of the pseudocarnioles is represented by chalk and anhydrite dissolution with sulphate-ion rich fluids, that were even able to attack the dolomitic rocks (fig. 5). the general dissolution and the presence of deep cavities from chalk dissolution have determined the decline of the geo-mechanical characteristics of the rock with the consequent collapse and formation of the "autoclastic pseudocarnioles". locally, gravity has offered real collapses with the formation of the residual pseudocarnioles. all of this can be followed by one or more cementation phases. dissolution can be accompanied by other processes (transcurrent and stretching tectonic, gravitational tectonic, anhydrite hydration, karst, etc.) that can act independently, repeatedly and in different moments, with varying intensity. the rocks resulting from these processes are known as “tectonic” pseudocarnioles and detrital pseudocarnioles, and can also act independently and repeatedly from the processes. the different types of pseudocarnioles constitute bodies with different dimensions, geometries and associations, each of which with the signs left behind by the conditioning processes. along the outcrops, the ca-carbonate precipitation from the circulating waters and the surface streams has induced the travertines formation with the development of decimetric cemented crusts: the incrustation pseudocarnioles. the results furnished by the preliminary pollen analysis together with the relationships found among the detrital sub-facies by stream waters and some manufactured objects, indicate that the genetic process of the pseudocarnioles takes place between the postoligocene and today. thus, it is possible to ascertain that the genesis of the pseudocarnioles does not correspond to the triassic, but it might start at the very beginnig of the recent evolution parole chiave: evaporiti, dissoluzione, carsismo, carbonati, quaternario, valle di susa, piemonte, italia. di calcari e di dolomie. con queste mostrano solamente rapporti di sovrapposizione geometrica ma mai stratigrafica originaria: il contatto con il substrato avviene tramite superfici di discontinuità di genesi molto più recenti. molto spesso le pseudocarniole si trovano associate a evaporiti, in special modo gessi e anidriti (tav. i foto a); per questo motivo in passato sono state in genere interpretate come autentiche carniole. un’altra caratteristica è la loro distribuzione, soprattutto sotto forma di masse allungate e poco potenti, in corrispondenza o in prossimità di importanti contatti tettonici (faglie, sovrascorrimenti) tant’è che in letteratura è stato loro attribuito un significato di “lubrificante tettonico” (analogamente a quello delle carniole triassiche). 2. inquadramento delle aree in studio oggetto del presente studio sono alcuni ammassi di pseudocarniole affioranti in alta valle di susa, all’estremo settentrionale delle alpi cozie. gli ammassi studiati, riportati in fig. 1, si trovano sulle pendici del m. segurét, a sud di bardonecchia e in val thuras. nell’alta valle di susa affiorano unità appartenenti, nelle interpretazioni classiche, ai “domini paleogeografici” piemontese e brianzonese (fig. 1). seguendo lo schema interpretativo di polino et alii (2002), proposto in base ai risultati delle indagini effettuate recentemente per la realizzazione del foglio 132-152-153, “bardonecchia”, della nuova carta geologica d’italia alla scala 1:50.000, sono state distinte una serie di unità tettonostratigrafiche (sensu dela pierre et alii, 1997) definite rispettivamente “di margine continentale”, “oceaniche” e “ofiolitiche”. 189proposta di classificazione delle ... le “unità di margine continentale” comprendono: un basamento cristallino pre-triassico monoe polimetamorfico e una successione autoctona di metasedimenti mesozoici di copertura, costituita da calcescisti, marmi e quarziti. questo insieme viene indicato come unità tettonostratigrafica dell’ambin. un gruppo di unità di copertura, a prevalenti rocce carbonatiche mesozoiche e a subordinati calcescisti. le “unità oceaniche”, intese come unità deposte su crosta oceanica, mostrano successioni costituite da prevalenti calcescisti e da subordinati marmi, quarziti e “pietre verdi”. le “unità ofiolitiche” sono costituite da successioni a prevalenti calcescisti e ofioliti; la loro deposizione su crosta oceanica non è certa. il quadro deformativo duttile delle unità a calcescisti del dominio piemontese è stato analizzato nel dettaglio da allenbach (1982) e allenbach & caron (1986). la deformazione duttile polifasica delle unità dell’ambin è ben espressa nei lavori di lorenzoni, (1965), gay (1971), callegari et alii (1980), allenbach & caron (1986), borghi & gattiglio (1997). la successione dei principali eventi deformativi alpini si può sintetizzare nel modo seguente: f1 e f2: sviluppo delle prime due fasi deformative scistogene di età alpina ad assi tra loro trasversali; f3: deformazione alpina a vergenza orientale associata alla traslazione delle falde alloctone sui terreni autoctoni del massiccio dell’ambin; f4: generazione di pieghe a doppia vergenza centrifuga (verso nord e verso sud) associate ad una fase tardiva in cui avviene il sollevamento del massiccio dell’ambin. per quanto concerne la deformazione fragile, questa è fig. 1 schema geologico-strutturale (da polino et alii, 2002, modificato) geological-structural outline (from polino et alii, 2002, modified). zona piemontese unità a collocazione paleogeografica incerta. unità mesozoiche di margine continentale con successioni terrigene liassiche. unità ofiolitiche prive di metamorfismo alpino. a metamorfismo alpino in facies scisti blu. a metamorfismo alpino in facies eclogitica. falde pennidiche unità mesozoiche di copertura (subbrianzonese auct.) unità mesozoiche di copertura più o meno scollate (brianzonese p.p.) unità di basamento a prevalente metamorfismo alpino in facies scisti blu (unità del g.s. bernardo). unità di basamento a prevalente metamorfismo alpino in facies eclogitica. principali masse di gessi e carniole. avanpaese depositi terrigeni di avanfossa. successioni mesozoiche e terziarie di copertura. basamento dei “massicci cristallini esterni”. fronte pennidico faglie depositi alluvionali. scala 1:1.000.000 ❶ ❷ ❸ aree di studio: bardonecchia segurét val thuras rappresentata da tre principali sistemi di faglie sub verticali: n60, n100/n140 e submeridiana. il sistema n60, con intervallo di valori compresi tra n40 e n70, presenta sistemi coniugati di tipo distensivo con piani immergenti a nw e se con marcate evidenze di trascorrenza sinistra. il sistema n100/n140 mostra un debole carattere trascorrente destro ed evidenze di distensione con prevalente ribassamento dei lati meridionali. il sistema submeridiano, con valori di direzione dei piani compresi tra n160 e n10, è caratterizzato da movimenti di tipo distensivo. per quanto riguarda i dati di inquadramento delle aree di studio nell’ambito dell’evoluzione neotettonica di questo settore della catena, occorre premettere che l’intervallo di tempo considerato non è strettamente 190 tavola i – a) rapporti geometrici tra le pseudocarniole ed altri termini litologici: situazione esemplificativa nell’area di bardonecchia (ps: pseudocarniole; ge: gessi; cs: calcescisti; cd: calcari dolomitici). b) contesto geomorfologico di affioramento delle pseudocarniole: le cavità carsiche del segurét (grotta dei saraceni). c) deformazione neotettonica entro le pseudocarniole: faglia normale subverticale visibile sulla parete della galleria militare nei pressi del segurét. d) fenomeno di inversione del rilievo in corrispondenza degli ammassi domiformi isolati di pseudocarniole nell’area del segurét. e) dettaglio dei rapporti geometrici tra diverse facies delle pseudocarniole: sub-facies detritica con trasporto che riempie fratture aperte entro le pseudocarniole autoclastiche. f) diverse generazioni di cemento calcitico entro le pseudocarniole, evidenziate in catodoluminescenza: 1 = cemento intragranulare non luminescente, 2 = cemento intergranulare non luminescente, 3 = cemento intergranulare luminescente. a) geometrical relationships between the pseudocarnioles and other lithological terms: example zone at bardonecchia (ps: pseudocarnioles; ge: chalks; cs: calc-schists; cd: dolomitic limestones). b) geomorphological outcrop context of the pseudocarnioles: segurèt’s karst cavities (grotta dei saraceni). c) neotectonic deformation within the pseudocarnioles: sub-vertical normal fault visible along the wall of the military gallery near the segurét. d) ground inversion phenomenon in correspondence of the isolated dome-like pseudocarnioles in the area of the segurét. e) geometrical relationships detail among different facies of the pseudocarnioles: fine detrital sub-facies that fills in open fractures within the “autoclastic” pseudocarnioles. f) different generations of calcium cement within the pseudocarnioles underlined by cathode luminescence: 1 = intra-granular non luminescent cement, 2 = inter-granular non luminescent cement, 3 = inter-granular luminescent cement. w. alberto et al. 191 limitato al quaternario, ma comprende anche gli episodi deformativi tardo-cenozoici che hanno determinato l’assetto recente della catena e ne condizionano l’attuale evoluzione superficiale. in letteratura (enel, 1981; giardino & polino, 1997) e nel corso del rilevamento svolto per il presente lavoro sono stati identificati “indizi morfotettonici” e deformazioni superficiali (trincee, scarpate di linea di faglia) variamente orientati e faglie subverticali di diversa estensione e rigetto con direzioni prevalenti n60 e n120, subordinatamente n20 e n160, che interessano il substrato prequaternario e le formazioni superficiali, ivi comprese le pseudocarniole (tav. i foto c). 3. le pseudocarniole l’abbondante presenza delle pseudocarniole nelle aree scelte per lo studio ne ha consentito un’accurata analisi: in primo luogo sono stati effettuati rilevamenti geologici che hanno portato alla redazione di una cartografia di dettaglio (carte geologiche della media val thuras alla scala 1:2.500, del segurét e della conca di bardonecchia alla scala 1:5.000 per una copertura complessiva di 30 km2) e alla raccolta di circa 200 campioni. successivamente sono state preparate una cinquantina di sezioni sottili, ricavate dai campioni più significativi, per le microanalisi al microscopio ottico in luce trasmessa, al sem e in catodoluminescenza (di seguito cl). a conclusione del rilevamento è stata messa a punto una classificazione delle pseudocarniole (tab. 1), basata essenzialmente sulle caratteristiche litologiche, tessiturali, strutturali alla mesoe macroscala, dei rapporti con le rocce circostanti, delle relazioni con il carsismo, della deformazione e alterazione. questa classificazione è stata successivamente interpretata in chiave genetica, in funzione del fatto che anche minime variazioni nei caratteri tessiturali e strutturali (distinguibili più o meno agevolmente sul terreno) mostrano in qualche caso di essere la risultante di processi genetici differenti; questo passaggio è reso però localmente complicato dalla scarsa accessibilità e/o visibilità degli affioramenti. in seguito alle osservazioni e alla raccolta dei dati sul terreno e alla loro successiva archiviazione in un data-base relazionale, progettato anche per facilitare ed automatizzare i processi dell’analisi statistica degli aspetti legati alle diverse tipologie di situazioni riconosciute, si è giunti all’individuazione di cinque facies principali ulteriormente distinte, ove possibile, in subfacies. di ogni facies o sub-facies è stato indicato, quando identificabile con sufficiente grado di affidabilità, il tipo di roccia da cui ha preso origine, attraverso una serie di processi, la pseudocarniola nel suo aspetto attuale. viene riportata di seguito la classificazione risultante dall’evidenza di differenze oggettive riscontrate sul terreno fra le diverse facies. per ognuna di queste viene poi proposta un’interpretazione genetica. 3.1. pseudocarniole "autoclastiche" tutte le pseudocarniole attribuite alla facies "autoclastica" sono costituite da brecce monogeniche (calcaree o dolomitiche, a seconda del contesto geologico); i clasti sono sempre decisamente angolosi, non classati, mostrano di non aver subìto rotazioni e hanno dimensioni variabili da meno di un centimetro a più metri. talvolta si riconoscono tracce di stratificazione ereditate dall’assetto strutturale originario del “protolite” più o meno mascherate dalla fratturazione (tav. ii foto a); la matrice può essere presente o assente. le analisi in cl hanno mostrato per le pseudocarniole "autoclastiche" la presenza di più fasi di cementazione alternate a fasi di dissoluzione e fratturazione. sono presenti cementi sia calcitici (spatici, limpidi o torbidi in luce trasmessa, talvolta zonati in cl a bande sui colori del giallo, senape, marrone), sia dolomitici (spatici, anche in cristalli di dimensioni plurimillimetriche, generalmente torbidi); in alcuni casi entro queste ultime fasi si riconoscono cristalli, anche pecilotopici, di fluorite. i cementi non carbonatici sono costituiti da quarzo di neoformazione in piccoli cristalli non deformati e anche da calcedonio. i rapporti cronologici di crescita dei diversi cementi non sono stati completamente chiariti. tali caratteristiche indicano l’assenza di processi a) pseudocarniole “autoclastiche” b) pseudocarniole residuali 1sub-facies detritica senza trasporto 2asub-facies detritica ad opera di acque incanalate c) pseudocarniole detritiche 2sub-facies detritica 2bsub-facies detritica ad opera di acque ruscellanti con trasporto allo sbocco di circuiti carsici esumati parzialmente attivi sub-facies di colata) 2csub-facies detritica ad opera di acque ruscellanti per riempimento di cavità carsiche epigee d) pseudocarniole incrostanti e) pseudocarniole “tettoniche” tab. 1 classificazione delle “pseudocarniole” dell’alta valle di susa. “pseudocarniole’s” classification of high susa valley. proposta di classificazione delle ... 192 tavola ii – a) pseudocarniole "autoclastiche": sono visibili le tracce di stratificazione ereditate dal processo di “carniolizzazione”, l’aspetto detritico debolmente vacuolare, l’eterogeneità nelle dimensioni dei clasti. b) pseudocarniole residuali: i clasti monogenici di dolomia, angolosi e non selezionati, sono separati da porzioni discontinue e irregolari di matrice di colore giallo. c) pseudocarniole detritiche: breccia poligenica, stratificata; l’arrotondamento dei clasti varia da sub-angoloso a sub-arrotondato; nel campione il livello superiore è composto da sedimenti attribuiti alla sub-facies detritica con trasporto. d) pseudocarniole detritiche con trasporto: sulla superficie di strato è visibile un’impronta da impatto di goccia d’acqua, testimonianza dello stillicidio in ambiente carsico ipogeo. e) pseudocarniole incrostanti: crostoni e fenomeni di travertinizzazione sulle superfici di esposizione subaerea. f) pseudocarniole "tettoniche": lungo alcuni piani di movimento sono evidenti le locali trasformazioni delle dolomie incassanti per opera dei fluidi circolanti. a) “autoclastic” pseudocarnioles: traces of stratification inherited by the “carniolisation” process; the poorly vacuolar detrital aspect, the heterogeneity in the dimensions of the clasts. b) residual pseudocarnioles: the monogenetic clasts of dolomites, angular and not sorted, are separated by discontinuous and irregular portions of yellow color matrix. c) detrital pseudocarnioles: stratified poligenetic breccia; the clasts vary from sub-angular to sub-rounded; considering the hand-example the higher level is composed by fine detrital sub-facies sediments. d) fine detrital pseudocarnioles: a water drop imprint is visible on the surface testifying the dripping process in a karst ipogeous environment. e) incrust pseudocarnioles: incrustations and travertine phenomena on the aerial exposure surfaces. f) “tectonic” pseudocarnioles: local transformation of the wall dolomites along some movement planes because of the circulating fluids. w. alberto et al. di prelievo, trasporto, selezione, rielaborazione e di deposizione dei clasti. inoltre, non esistendo prodotti cataclastici né strutture orientate, è possibile escludere fenomeni deformazionali singenetici e quindi una relazione diretta con la tettonica. ciononostante la pervasività della fratturazione indica il passaggio dell’ammasso roccioso attraverso una fase di generalizzata instabilità (“gravitativa”, nel senso più ampio del termine); in più, il fatto che i clasti non siano ruotati, siano cioè sostanzialmente “in posto”, indica che questa instabilità non ha modificato significativamente l’assetto generale dell’ammasso. 3.2. pseudocarniole residuali in generale la facies residuale è composta da brecce monogeniche (calcaree o dolomitiche), a clasti angolosi non classati e con matrice sempre presente (tav. ii foto b). localmente possono essere debolmente stratificate. generalmente includono numerosissimi elementi di pseudocarniole in facies "autoclastica" con dimensioni variabili che possono raggiungere anche la decina di metri. le analisi in cl hanno mostrato anche in questo caso l’esistenza di più fasi cementizie a chimismo differente. si riconoscono più fasi dolomitiche a grossi spati torbidi anche in luce trasmessa, cui si aggiungono alcuni cristalli di quarzo di neoformazione e piccole vene di dolomite debolmente zonata in cl; è presente almeno una fase calcitica a spati limpidi in luce trasmessa ma zonati in cl. la facies residuale presenta caratteri peculiari, oltre a quelli comuni alla facies "autoclastica" (clasti monogenici e mal selezionati): la presenza, a tratti anche abbondante, di matrice indica l’attività di fenomeni deposizionali per circolazione nei vuoti tra i clasti di acque con carico solido fine; la presenza di blocchi e porzioni di dimensioni varie (anche notevoli, decametriche) di rocce della facies "autoclastica" all’interno di ammassi di pseudocarniole residuali indica il legame (se non addirittura un rapporto di derivazione diretta) delle seconde nei confronti delle prime. 3.3. pseudocarniole detritiche la facies detritica è costituita sia da brecce o conglomerati a clasti generalmente poligenici, a classazione variabile, matrice sempre presente, tessiture clasto matrix-supported, sia da sedimenti fini generalmente sabbioso-siltosi. la distinzione in sub-facies si rende necessaria per discriminare le diverse geometrie, dimensioni e associazioni di queste rocce. le pseudocarniole detritiche presentano caratteri che permettono di distinguerle, in genere facilmente, da quelle "autoclastiche" e residuali e soprattutto ne indicano una genesi differente. la selezione nella pezzatura dei clasti, cui si aggiunge talvolta la forma da sub-arrotondata ad arrotondata, indica l’azione di fenomeni di rielaborazione, di selezione e di trasporto del materiale poligenico; la presenza costante di matrice, talvolta organizzata in potenti livelli in cui sono visibili varie strutture sedimentarie deposizionali da correnti trattive, indica la presenza di processi sedimentari di ambiente subacqueo (tav. ii foto c); la posizione marginale, a tetto o entro le pseudocarniole "autoclastiche" e residuali, indica uno stretto legame genetico tra le diverse facies. la presenza di corpi di pseudocarniole detritiche come riempimento di cavità di evidente origine carsica (condotti, imbuti, doline) indica uno stretto rapporto genetico e cronologico tra questo tipo di pseudocarniole ed il carsismo. entro alla categoria delle pseudocarniole detritiche sono state distinte più sub-facies. 3.3.1. sub-facies detritica senza trasporto: brecce a clasti poligenici, prevalentemente angolosi e mal classati, con dimensioni variabili da centimetriche a metriche. la tessitura varia da clast supported a più raramente matrix supported. la matrice presenta un’alta variabilità granulometrica, passando dai silt alle sabbie ghiaiose; i granuli hanno la stessa composizione dei clasti. si osservano inoltre rare strutture sedimentarie (es. gradazione); la cementazione e l’addensamento variano notevolmente da zona a zona. questo tipo di brecce è caratterizzato da due principali motivi tessiturali: si presentano infatti o massicce ed eterogenee o grossolanamente stratificate. nel primo caso ci si trova di fronte ad un deposito caotico in cui da punto a punto variano le caratteristiche sedimentologiche complessive; nel secondo, la breccia si presenta stratificata ma in modo poco evidente: a volte gli unici indizi di stratificazione sono rappresentati dagli allineamenti dei clasti maggiori. in ogni caso, la stratificazione è sempre piano-parallela ed è caratterizzata da inclinazioni modeste ed immersioni che ricalcano quella del versante su cui si sviluppano. si rinvengono principalmente alla base dei versanti o al passaggio tra le pareti modellate nel substrato e il detrito di falda. si tratta di materiale detritico cementato dai carbonati contenuti nelle acque circolanti. 3.3.2. sub-facies detritica con trasporto questa sub-facies è rappresentata da brecce o microbrecce passanti, per termini intermedi, a conglomerati o microconglomerati; i clasti possono essere poligenici o monogenici. tutte le pseudocarniole di questa sub-facies hanno una tessitura matrix-supported più raramente clast-supported, sono fortemente cementate, presentano strutture sedimentarie deposizionali come ripple, laminazioni e isoorientazioni dei clasti la cui pezzatura è relativamente uniforme, con valori che oscillano intorno a pochi centimetri. i sedimenti molto fini e molto selezionati fungono spesso da matrice rispetto ai clasti più grossolani, oppure possono costituire corpi omometrici. presentano un’elevata disomogeneità nell’aspetto dovuta alle diverse combinazioni di tutte le caratteristiche sedimentologiche sopra descritte. comunemente questa sub-facies costituisce il riempimento di forme di corrosione carsica ipogee esumate dall’erosione: i depositi colmano interamente o parzialmente condotti, fusoidi e cavità; queste sono particolarmente diffuse allo sbocco delle grotte carsiche più imponenti: ad esempio nella zona del monte segurét presso le grotte dei saraceni. le pseudocarniole di questa sub-facies presentano alcuni parametri tessiturali caratteristici; la generale classazione della frazione grossolana e la presenza di 193proposta di classificazione delle ... elementi arrotondati indicano l’azione di processi di selezione e quindi di trasporto fisico ad opera delle acque. questi processi possono essere concentrati oppure costituire masse anche di parecchi metri cubi di depositi: ne risulta una gamma di geometrie e di dimensioni degli accumuli piuttosto varia (lenti di potenza decimetrica ed estensione metrica, bancate potenti fino a qualche metro ed estensione pluridecametrica, masse irregolari pluridecametriche come spessore ed estensione). i depositi possono essere stati ripresi nel circuito carsico e aver subito ulteriore trasporto da parte delle acque incanalate; quindi possono essere stati ridepositati assieme a materiali di primo ciclo (non è raro rinvenire clasti costituiti da pseudocarniole con trasporto all’interno di facies più recenti), o essere stati trasportati per tempi più prolungati, fatto che porta ad una progressiva riduzione della pezzatura e ad una maggiore selezione dei litotipi che costituiscono i clasti. 3.3.2.1 sub-facies detritica con trasporto ad opera di acque incanalate e’ rappresentata da sedimenti ben selezionati, con granulometrie che variano dalle ghiaie ai silt argillosi. i depositi più fini, compresi tra i silt ed i silt argillosi, mostrano laminazioni piano-parallele o ondulate parallele le quali costituiscono le uniche strutture sedimentarie deposizionali presenti in questa facies. con l’aumentare delle dimensioni dei granuli è più facile osservare strutture sedimentarie più complesse: nell’intervallo granulometrico compreso tra i silt e le sabbie fini, compaiono laminazioni inclinate a basso angolo e sono conservati ripple asimmetrici o simmetrici. le sabbie presentano strutture più marcate come laminazioni a festoni e convolute, superfici erosionali concave e gradazioni normali più o meno evidenti. questa sub-facies è in assoluto la più diffusa e abbondante tra le pseudocarniole detritiche. i sedimenti fini associati alle altre facies rivestono un’importanza notevole: rappresentano forse l’unica litofacies in cui sono stati registrati e si sono conservati tratti sedimentari indicativi di una lunga fase dell’evoluzione delle pseudocarniole. si rinvengono associati a quasi tutte le sub-facies, mostrando di rappresentare l’ultimo prodotto locale della loro rielaborazione. la presenza, sebbene rara, di tracce di impatto di gocce d’acqua rilevate sulle superfici di stratificazione dei depositi a sedimenti più fini, suggerisce una genesi in ambiente carsico ipogeo in cui è comune lo stillicidio dalle volte dei condotti e delle sale (tav. ii foto d). la presenza di geometrie molto diverse sembra indicare una sedimentazione in ambiti pure molto diversi: da un lato, il ritrovamento di diffuse strutture sedimentarie deposizionali da correnti trattive entro i depositi fini isolati o costituenti la matrice di altre sub-facies indica una sedimentazione in ambiente subacqueo ad alta energia; dall’altro, la distribuzione su aree talora anche relativamente estese sembra riconducibile alla deposizione in specchi d’acqua ipogei con superfici fino a centinaia di metri quadrati. questa sub-facies si ritrova, inoltre, spesso a riempire fratture e piccole cavità di dissoluzione nel substrato o in altre facies di pseudocarniole (tav. i foto e). la frazione fine è soggetta ad una forte mobilizzazione e, grazie alle sue caratteristiche granulometriche, si accumula negli ambiti più disparati. si ritrova spesso alla sommità delle successioni detritiche di trasporto più grossolane; in questi casi la laminazione piano-parallela indica condizioni di stagnazione, in cui il sedimento fine è decantato indisturbato, sigillando il ciclo sedimentario all’interno del circuito carsico (tav. ii foto c). 3.3.2.2 sub-facies detritica con trasporto ad opera di acque ruscellanti (o per colata) e’ costituita da microbrecce matrix supported, scarsamente cementate e addensate, con clasti poligenici, mal selezionati, di dimensioni centimetriche, immersi in una matrice sabbioso-siltosa. il deposito è organizzato in lamine di spessore variabile e con andamento irregolare, anche se si mantiene un certo parallelismo delle superfici di laminazione. i clasti di dimensioni più modeste sono subarrotondati e organizzati in stone line, mentre i clasti maggiori sono angolosi, hanno una disposizione caotica e costituiscono elementi di disturbo delle superfici di laminazione. gli ammassi hanno una geometria irregolare e terminano in una serie di piccoli lobi. i valori d’inclinazione e d’immersione della laminazione sono del tutto paragonabili a quelli del versante su cui poggia il deposito. si ritiene che questa sub-facies si origini dalla deposizione di sedimenti tramite meccanismi di colata (trasporto innescato da parte delle acque di ruscellamento diffuso o canalizzato). il materiale rimobilizzato proviene dallo smantellamento della sub-facies detritica di trasporto ad opera di acque incanalate che defluiscono dal circuito carsico; il fenomeno è particolarmente evidente allo sbocco delle principali grotte del segurét, come la grotta dei saraceni. tali depositi sono tuttora in formazione, com’è indicato dall’appoggio locale di questa sub-facies su manufatti di cemento. 3.3.2.3. sub-facies detritica con trasporto ad opera di acque ruscellanti per riempimento di cavità carsiche epigee si tratta di depositi molto mal selezionati e fortemente cementati, caratterizzati da una tessitura matrixo clast-supported. i clasti poligenici variano di dimensioni, forma e grado di arrotondamento. si passa da grossi blocchi, tabulari e angolosi o sub-sferici ed arrotondati, a ciottoli levigati e smussati o clasti angolosi di forma equidimensionale o prismatica, immersi in una matrice da siltoso-sabbiosa a sabbioso-ghiaiosa. la composizione dei clasti è variabilissima e comprende rocce del substrato, frammenti di altre pseudocarniole e materiale proveniente da formazioni superficiali. si tratta di sedimenti deposti in tasche imbutiformi riconducibili a piccole forme carsiche epigee modellate nel substrato carbonatico o nelle facies "autoclastica" e residuale dopo la loro esumazione. l’addensamento e la cementazione del deposito hanno reso quest’ultimo più resistente allo smantellamento rispetto alle rocce incassanti. per questo motivo si rinvengono spesso lembi di questa sub-facies isolati e con una morfologia pinnacolare o domiforme. i fenomeni di inversione di rilievo sono facilitati dalle locali scadenti condizioni meccaniche delle rocce interessate dal modellamento carsico. 194 w. alberto et al. 3.4. pseudocarniole incrostanti la facies incrostante è composta da abbondanti quantità di cemento carbonatico screziato (varie tonalità di giallo, di grigio e bianco) in cui si possono rinvenire piccoli clasti angolosi di diversa natura; tipico è l’aspetto vacuolare. questa facies è arealmente abbastanza diffusa e forma delle sottili croste (al massimo 30 centimetri di spessore) su superfici esposte di altri tipi di pseudocarniole, mascherandone il reale aspetto e rendendole quindi apparentemente del tutto simili tra loro. le pseudocarniole incrostanti possono anche costituire piccole masse, potenti fino a 50 cm, ai piedi di pareti rocciose. questa facies sembra prendere origine per fenomeni paragonabili a quelli che danno luogo ai travertini detritici (d’argenio & ferreri, 1986) in quanto sono il risultato della cementazione di materiale di provenienza diversa per precipitazione di carbonato di calcio contenuto nelle acque ruscellanti superficiali. lo sviluppo dei crostoni appare legato direttamente al tempo di esposizione delle pseudocarniole agli agenti climatici; la genesi di queste rocce abbraccia un intervallo di tempo imprecisabile successivo all’esposizione (tav. ii foto e). 3.5. pseudocarniole "tettoniche" le pseudocarniole “tettoniche” presentano caratteristiche tessiturali variabili, ma sono accomunate dalla geometria tabulare e dalla distribuzione lungo piani di movimento e zone di taglio. al loro interno si riconoscono segni di deformazione (litoni “boudinati”, superfici di movimento) ma anche porzioni indeformate. il tutto suggerisce che si tratti di rocce formatesi ed evolutesi in un ambiente influenzato (direttamente e indirettamente) dai piani di movimento. alcune porzioni possono essere considerate rocce di faglia, di genesi pree sin-deformazione; mentre altre (non deformate) si sono potute formare in funzione della maggiore circolazione di fluidi lungo i piani senza influenza diretta della deformazione: in questi casi si passa infatti gradualmente da pseudocarniole a prodotti idrotermali veri e propri (ematite, albite, solfuri di pb e fe) (tav. ii foto f). 4. il ruolo dei fluidi nella genesi e nell’evoluzione delle pseudocarniole mostra di aver svolto un ruolo molto importante la circolazione di fluidi; questi hanno prodotto più o meno marcate modificazioni chimiche nell’ammasso roccioso, condizionandone il comportamento geomeccanico e la reologia. per ricostruire la variazione nel tempo e nello spazio della natura, delle condizioni chimico-fisiche e del percorso dei fluidi (risalenti dal basso all’alto, per ascensum, o, viceversa, percolanti per descensum), occorre analizzare le loro manifestazioni (chimismo dei cementi, mineralizzazioni, ricristallizzazioni, dissoluzioni dell’ammasso roccioso, precipitazione di concrezioni e chimismo delle acque sorgenti) nelle diverse situazioni. queste mostrano di essersi succedute nel tempo nei diversi settori in relazione alla riduzione dello spessore dell’ammasso sovrastante conseguente all’erosione fino alla situazione di esumazione attuale. i sistemi di frattura legati geneticamente all’attività tettonica più recente mostrano di aver interessato gli ammassi di pseudocarniole aumentandone la permeabilità: a quella originaria per porosità si è aggiunta quindi una permeabilità per fratturazione. al fine di chiarire l’origine e il contributo dei fluidi e per stabilire quindi la presenza o meno di più generazioni di cemento e gli eventuali loro rapporti sono state effettuate analisi in cl di alcune sezioni sottili di pseudocarniole. in tab. 2 vengono indicati i singoli minerali che costituiscono il cemento delle pseudocarniole, la loro natura primaria o secondaria con riferimento al “protolite”, il tragitto dei fluidi che hanno dato loro origine e l’ambiente geologico di formazione. la tecnica della catodoluminescenza si basa sull’analisi della luminescenza emessa da un materiale (un cristallo) in seguito all’eccitamento con un fascio di elettroni; per le generalità si veda marshall (1988). nel campo della geologia, la cl permette un’analisi dettagliata delle componenti mineralogiche di una roccia, in particolare trova interessanti campi di applicazione nello studio delle mineralizzazioni e dei cementi. all’interno di questi, i componenti carbonatici mostrano una cl molto sensibile alle variazioni di composizione e di tenore in cationi (fe++ e mn++) all’interno del minerale calcitico. l’analisi in cl dei cementi delle pseudocarniole permette da un lato di distinguere cementi carbonatici precipitati in condizioni geochimiche differenti e dall’altro di riconoscere i diversi componenti mineralogici di un cemento (per un esempio di studio approfondito di 195 tab. 2 caratteristiche dei minerali che costituiscono i cementi delle pseudocarniole. minerals characteristics of pseudocarniole’s cements. minerale natura origine ambiente calcite primaria-secondaria ascensum-descensum idrotermale-meteorico dolomite primaria-secondaria ascensum idrotermale quarzo secondaria ascensum idrotermale albite secondaria ascensum idrotermale ankerite secondaria ascensum idrotermale ematite secondaria ascensum idrotermale calcedonio secondaria ascensum idrotermale fluorite secondaria ascensum idrotermale solfuri di pb e fe secondaria ascensum idrotermale proposta di classificazione delle ... tale campo si veda amieux & jeanbourquin, 1989). nelle aree del segurét e di bardonecchia l’attività idrotermale è documentata dalla presenza di mineralizzazioni (calcite, ankerite, albite, solfuri di ferro e di piombo, ossidi di ferro) in passato oggetto di coltivazione (“miniere dei saraceni” nel versante orientale del segurét; mineralizzazioni a rame, ferro e galena argentifera sono ospitate nelle rocce del massiccio d’ambin e sono state oggetto di limitati sfruttamenti verso la fine del xix° secolo; cfr. lomagno, 1992). dal risultato delle analisi in cl si sono evidenziate varie situazioni: nel caso del segurét la cementazione da parte della calcite precipitata dai fluidi idrotermali si somma ad una preesistente cementazione dovuta alla precipitazione di calcite meteorica. questo sta ad indicare che l’ascensum di fluidi idrotermali ha influenzato l’evoluzione delle pseudocarniole in un secondo momento, contribuendo di volta in volta alla cementazione, alla dedolomitizzazione e alla dissoluzione dei clasti calcareo-dolomitici. in val thuras è stato invece verificato che la natura (dolomite romboedrica, quarzo, calcedonio, fluorite) e la struttura (grossi spati limpidi, ricristallizzazione pervasiva dei clasti dolomitici) dei cementi indica concordemente una genesi da soli fluidi caldi, quindi in ambiente relativamente profondo e riducente. l’origine di questi fluidi è complessa da definire: in molti casi (cementi a quarzo o a calcedonio) è possibile escludere un’origine da acque meteoriche infiltratesi per descensum, poiché mancano totalmente coperture silicatiche (e se ne può escludere anche la presenza prima del parziale smantellamento dell’edificio strutturale da parte dell’erosione) da cui questi avrebbero potuto prendere origine; in altri numerosi casi (cementi a dolomite e fluorite) l’origine per ascensum è indicata dal chimismo. 5. cronologia la collocazione cronologica delle pseudocarniole rappresenta uno dei temi più dibattuti per quanto riguarda questo tipo di rocce. l’arco temporale in cui, sulla base della letteratura geologica esistente, potrebbe essere avvenuta la formazione di queste rocce copre l’intervallo compreso tra il trias e l’olocene. una spiegazione di ciò può essere ricercata nel fatto che non esiste tuttora una definizione univoca delle pseudocarniole e questo è funzione principalmente della convergenza di facies che coinvolge rocce con storie evolutive molto differenti. nel campo delle pseudocarniole, così come sono state definite nel presente lavoro, esistono delle difficoltà oggettive nell’inquadrarne cronologicamente la genesi. un primo approccio alla definizione cronologica delle pseudocarniole viene offerto dalle datazioni indirette: queste non forniscono età numeriche ma permettono un inquadramento di massima. un primo elemento è dato dalla presenza di clasti a deformazione e metamorfismo alpini (calcescisti, ad esempio, nelle pseudocarniole residuali del seguret); il fatto che alcuni corpi di pseudocarniole sigillano strutture alpine (seguret); l’assenza di metamorfismo e di deformazioni alpine (val thuras, seguret). questi elementi definiscono un termine postquem e concorrono nell’indicare per gran parte delle pseudocarniole alpine un’età almeno post-oligocenica. in qualche caso il processo evolutivo prosegue tuttora in funzione soprattutto della rielaborazione carsica: una conferma si ha osservando l’appoggio di un corpo della sub-facies detritica di colata su alcune opere antropiche (blocchi di cemento delle strutture di servizio per l’estrazione mineraria, avvenuta tra fine ottocento e il decennio 1960) allo sbocco delle grotte dei saraceni, nell’area del segurèt. nell’ampio intervallo di tempo compreso tra postoligocene e l’attuale è possibile collocare cronologicamente alcuni elementi caratteristici delle pseudocarniole mediante altri tipi di datazione diretta. gli elementi che si prestano ad essere datati sono i riempimenti sabbioso-limosi del circuito carsico impostato nelle pseudocarniole i quali possono aver intrappolato pollini provenienti dalla superficie. le analisi palinologiche possono fornire quindi delle indicazioni cronologiche (e anche paleoambientali) di maggior dettaglio; con questa tecnica non si data la parte iniziale dell’evoluzione delle pseudocarniole ma si individua il momento in cui l’ammasso viene intercettato dal circuito carsico, a partire dal quale si attivano i processi che portano alla formazione delle pseudocarniole detritiche. nell’ambito degli studi condotti nell’area del seguret, l’esame palinologico preliminare di un campione della subfacies detritica fine con trasporto ad opera di acque incanalate, gentilmente effettuato dalla prof.ssa l. cattani dell’università di ferrara, ha fornito i seguenti risultati: (i valori numerici non sono stati tradotti in percentuali poiché il totale dei granuli pollinici e la varietà dei taxa botanici sono al di sotto della soglia di affidabilità) abies 5, cathaya 1, cedrus 6, pinus haploxylon 11 + 1 tetrade (la presenza di tetradi polliniche viene generalmente interpretata come presenza in loco della pianta), pinus dyploxylon 12, taxodium/ sequoia 2, alnus 1, betula 3, carpinus 4, castanea 1, quercus tipo caducifolia 2, fagus 2, parrotia 1, iridaceae 1, menyanthes 1, salvinia 2. secondo l’interpretazione effettuata dalla stessa prof. cattani, si riscontra una netta predominanza delle arboree e fra esse delle conifere sulle latifoglie; praticamente assenti risultano le erbacee, limitate a piante legate all'acqua, addirittura natanti quali il trifoglione d'acqua (menyanthes) e la salvinia (felce galleggiante). il campione era inoltre molto ricco di residui di materia organica, di protisti ciliati e di ife fungine. tutto il contenuto microscopico presentava lo stesso, buon grado di conservazione. l’associazione pollinica appare indicativa di un intervallo di tempo non meglio precisabile, esteso tra il pliocene superiore ed il quaternario basale. sulla scorta delle osservazioni sopra riportate, il processo evolutivo delle pseudocarniole appare svolgersi in un intervallo di tempo in genere ampio, diverso da una facies all’altra; inoltre non presenta limiti cronologici definibili univocamente. 196 w. alberto et al. complessivamente, sulla base dei dati raccolti, il processo genetico delle pseudocarniole attualmente affioranti è inquadrabile in un intervallo di tempo compreso tra post-oligocene e il presente; in particolare le pseudocarniole detrit iche sono state datate dal pliocene superiore al presente. 6. geomorfologia le pseudocarniole non sono caratterizzate da una propria espressione morfologica specifica in quanto la loro messa in posto è avvenuta per “accomodamento” in spazi resi disponibili a seguito di processi di diversa natura. nel caso delle pseudocarniole che hanno preso origine in profondità, dopo la loro esumazione queste rocce hanno invece dato luogo a situazioni morfologiche tipiche. i fattori che hanno controllato l’evoluzione geomorfologica sono essenzialmente la circolazione delle acque di origine meteorica e la gravità. le manifestazioni sono forme di erosione selettiva connesse con il dilavamento dei versanti, forme legate al carsismo e a fenomeni gravitativi. di notevole importanza appaiono inoltre gli effetti in superficie dell’intensa dissoluzione in profondità dei corpi gessosi e carbonatici; come già da tempo riconosciuto, ad esempio durante lo scavo della traforo del sempione (schardt, 1906), il volume di roccia asportato per dissoluzione può indurre importanti fenomeni di deformazione della superficie topografica, con formazione di collassi e anche di deformazioni gravitative profonde di versante (dgpv) (alberto et al., 2004). 6.1. l’esumazione e l’erosione selettiva la tipica situazione morfologica delle pseudocarniole è caratterizzata da versanti aspri e ripidi, guglie e creste dentellate. tali forme sono controllate prevalentemente dalle caratteristiche tessiturali (elevata permeabilità e preferenziali deflussi in senso verticale), geomeccaniche (forte disarticolazione) e talvolta anche di cementazione. nelle aree studiate si osserva inoltre una situazione di forte incisione dei corpi di pseudocarniole, tale da esporre tutta la successione fino al contatto con il substrato. le pseudocarniole, in special modo quelle detritiche, danno spesso luogo a manifestazioni di inversione di rilievo (pinnacoli, guglie e domi): da una originaria giacitura di riempimento di cavità sono giunte a costituire, con l’esumazione, rilievi isolati nell’edificio carbonatico. le fratture mostrano di aver facilitato il processo d’incarsimento degli ammassi di pseudocarniole; in alcuni casi hanno invece contribuito alla obliterazione di forme carsiche epigee modellate nel substrato calcareo-dolomitico esumando le sottostanti pseudocarniole della sub-facies di riempimento, dando infine luogo ai fenomeni di inversione di rilievo (tav. i foto d). in particolare l’espressione superficiale delle discontinuità fragili nel settore segurét vallonetto corrisponde talvolta ai limiti di depressioni e di settori collassati, evolutisi anche in relazione a fenomeni di dissoluzione e/o crollo legati al carsismo. 6.2. il modellamento carsico la presenza e l’evoluzione del fenomeno carsico in un lungo intervallo di tempo è testimoniata nelle aree rilevate da tipiche forme epigee e dalla presenza di forme ipogee quali fusoidi, condotti, gallerie, pozzi etc. esumate dall’erosione; nell’area di studio sono molto più comuni forme di questo secondo tipo. la distribuzione dei condotti è pressoché ubiquitaria negli affioramenti di pseudocarniole residuali ed è comunque molto abbondante anche nelle altre facies; minore invece nel substrato sia fratturato sia integro. il carsismo è il processo esogeno che più ha contribuito alla formazione ed all’evoluzione delle pseudocarniole. le acque meteoriche di percolazione o quelle iniettate nell’ammasso roccioso in seguito alla fusione delle masse glaciali sono responsabili della dissoluzione degli ammassi gessosi e carbonatici creando cavità ed ampliando quelle già esistenti. esse hanno operato il prelievo, il trasporto e la deposizione del sedimento che è andato a costituire le sub-facies detritiche con trasporto e la matrice delle altre facies. la grande mobilizzazione dei sedimenti ha portato in alcuni casi alla natura poligenica, in senso litologico, dei depositi. l’evoluzione del carsismo ha condotto ad un progressivo coinvolgimento anche delle facies "autoclastica" e residuale. gli ammassi appartenenti a tali facies vengono aggrediti dalle acque circolanti e diventano a loro volta sorgenti di sedimenti che andranno a costituire le sub-facies detritiche con trasporto. ovviamente, per maggior tempo il sedimento è stato coinvolto nel trasporto ad opera delle acque carsiche, più ha subìto una selezione granulometrica fino a costituire gli accumuli della sub-facies detritica con trasporto ad opera di acque incanalate. le acque carsiche trasportano in soluzione anche grandi quantità di caco3, prelevato in profondità dalle porzioni di rocce carbonatiche e destinato a precipitare dando origine al cemento calcitico intergranulare negli ammassi di pseudocarniole; più in superficie, lo stesso porta alla formazione delle croste carbonatiche sugli affioramenti e dei riempimenti delle fratture beanti. 7. modello interpretativo il rilevamento e l’analisi sistematica dei dati relativi alle caratteristiche dei diversi tipi di pseudocarniole (caratteristiche tessiturali, strutturali, rapporti con altre rocce, rapporti con fenomeni e processi geologici) ha condotto all’inserimento delle facies riconosciute in una proposta di classificazione preliminare; successivamente i diversi tipi di pseudocarniole sono stati inquadrati in un modello genetico specifico per le rocce e per la situazione geologico-strutturale della val thuràs, di bardonecchia e del monte segurét. le complesse variazioni di tutte le caratteristiche (tessiturali, di cementazione, di corrosione, di alterazione) osservabili sia tra pseudocarniole di facies differenti, sia entro la stessa facies o addirittura sub-facies, testimoniano una storia evolutiva molto articolata e molto diversa da punto a punto, anche in porzioni dell’ammasso roccioso molto vicine tra loro. tale varietà di situazioni deve essere trattata come l’espressione attuale della sovrapposizione e dell’iterazione di un numero imprecisabile di processi che hanno agito in contesti diversi e con modalità diverse 197proposta di classificazione delle ... condizionate direttamente dai contesti stessi. si è tentato di ricostruire la probabile successione degli eventi responsabili della genesi delle pseudocarniole, essendo consapevoli che la successione effettivamente riscontrata sul terreno può essere incompleta e variare da punto a punto. in un quadro più generale che tenga presente l’insieme delle modificazioni chimiche e fisiche responsabili della trasformazione delle rocce carbonatiche in pseudocarniole, i fluidi occupano una posizione di rilievo. l’origine dei processi di trasformazione può essere ricercata nell’originaria abbondante presenza di gessi (condizione particolarmente frequente anche in altre aree delle alpi) in seguito alle fasi deformative alpine e nella permeabilità dei “protoliti” carbonatici. la circolazione di fluidi nel sottosuolo può aver portato alla parziale o totale dissoluzione delle rocce evaporitiche (molto solubili); i fluidi, arricchiti in solfati (fluidi selenitosi), hanno permeato e aggredito le rocce carbonatiche ed in particolare anche le dolomie. la dissoluzione generalizzata e la presenza in profondità di cavità occupate originariamente dai gessi contribuiscono alla destabilizzazione generale dell’ammasso roccioso (con formazione di brecce definite in questo lavoro pseudocarniole "autoclastiche") e alla sua locale, successiva scompaginazione in elementi fortemente eterometrici (pseudocarniole residuali). al variare delle condizioni chimico-fisiche per riduzione di spessore dell’ammasso roccioso dovuto al sollevamento e alla conseguente erosione, nella stessa porzione di ammasso sono precipitate fasi cementizie entro i vuoti, con la contemporanea trasformazione dei clasti preesistenti. le soluzioni mineralizzate hanno potuto raggiungere la superficie topografica temporanea dando luogo a diverse manifestazioni: travertini, sorgenti calde, ecc. in bibliografia modelli analoghi a quello qui proposto sono stati descritti da jeanbourquin (1986) nel vallese e da vearncombe (1982) nel gran paradiso. entrambi definiscono la seguente reazione di dedolomitizzazione: camg(co3)2 (s) + ca++ (aq) + so4 -(aq) + h2o + fe 2caco3)2 (s) + mg++ (aq) + so4 -(aq) + feooh la diffusa presenza di depositi compresi tra le pseudocarniole come riempimento di forme carsiche ipogee ed epigee indica poi una stretta relazione tra alcuni tipi di pseudocarniole e il carsismo; il fenomeno mostra di aver agito per lungo tempo (numerosi sono i condotti di notevoli dimensioni) e in più cicli (piccoli condotti entro a gallerie occluse; inoltre in alcuni casi si hanno segni di una saltuaria attività di alcuni condotti mentre altri appartengono sicuramente a un paleocarso). l’azione del carsismo degli ammassi carbonatici risulta determinante nella genesi delle pseudocarniole di facies detritica; per le facies "autoclastica" e residuale il suo ruolo è meno evidente e non determinante, poiché sono invece i fenomeni più profondi di dissoluzione che interessano gli ammassi gessosi a rappresentare il principale agente genetico. 8. considerazioni conclusive e riassuntive per le brecce carbonatiche, di aspetto vacuolare e di colore da grigio a giallo a ocra, che affiorano nelle alpi occidentali e che rappresentano un litotipo molto comune, non vi è una terminologia condivisa (“carniole”, “cornieules”, “cargneules”, “rauhwacken”) e al pari vi sono numerose interpretazioni genetiche. nella letteratura geologica italiana si è manifestato un certo interesse solo nella seconda metà dell’ultimo decennio: le interpretazioni “classiche” (evaporiti triassiche) sono così risultate non coerenti con le nuove osservazioni raccolte. in primo luogo l’età pare essere molto più recente, perché contengono spesso clasti di rocce a 198 processi prodotti corrosione/erosione trasporto sedimentazione (cementazione) travertinisorgenti mineralizzate pseudocarniole detritiche substrato dolomitico e/o calcareo pseudocarniole «autoclastiche» e residuali precipitazione cementi dolomitici e calcitici dissoluzioni rocce carbonatiche selenitizzazione fluidi dissoluzione gessi rielaborazione epigea rielaborazione ipogea risalita fluidi termali fig. 2. modello genetico. genetic model. w. alberto et al. metamorfismo e deformazione di età alpina; la stessa genesi appare poi manifestamente non connessa con i meccanismi di sedimentazione evaporitica marina. per questi motivi si propone il termine “pseudocarniole” ad indicare delle brecce di aspetto molto simile alle carniole ma dalle quali differiscono per genesi ed età. sulla base dei dati emersi dalla recente letteratura e dei risultati delle ricerche condotte nell’ambito del presente studio, si propone inoltre una classificazione delle pseudocarniole della valle di susa basata sui caratteri litologici, tessiturali, strutturali, sui rapporti con altre rocce, sulle relazioni con la deformazione, il carsismo e l’alterazione: pseudocarniole “autoclastiche”: brecce monogeniche dolomitiche o calcaree, in cui sono riconoscibili le tracce dell’originaria stratificazione; pseudocarniole residuali: brecce monogeniche dolomitiche o calcaree, caotiche e ricche di matrice; pseudocarniole detritiche: brecce, conglomerati, arenarie e siltiti carbonatici per lo più poligenici, distinguibili in – senza trasporto e – con trasporto; pseudocarniole incrostanti: crostoni di cemento carbonatico; pseudocarniole tettoniche: brecce carbonatiche caratterizzate da tessiture variabili ma localizzate in corrispondenza di piani di faglia. il meccanismo-guida che sta alla base della formazione delle pseudocarniole è rappresentato dalla dissoluzione di gessi o anidriti ad opera di fluidi che, arricchendosi in ione solfato, sono in grado di aggredire anche le rocce dolomitiche. l’intensa dissoluzione genera una situazione di generale instabilità con conseguente assestamento gravitativo dell’ammasso (pseudocarniole "autoclastiche") in cui alcune porzioni risultano totalmente scompaginate (pseudocarniole residuali). a questo può seguire una fase o più fasi di cementazione. con l’esumazione dell’ammasso roccioso e l’impostazione di un carsismo, parte delle pseudocarniole "autoclastiche" e residuali subisce importanti rielaborazioni in ambiente ipogeo (pseudocarniole detritiche con trasporto) e epigeo (pseudocarniole detritiche senza trasporto). all’esposizione sub-aerea gli affioramenti di tutte le pseudocarniole vengono coperti da croste carbonatiche centimetriche (pseudocarniole incrostanti) per effetto della grande quantità di carbonati disponibili in superficie e riprecipitati dalle acque di ruscellamento. proprio la presenza di tali croste, unitamente alla comune associazione con masse gessose triassiche e alla frequente distribuzione lungo piani di sovrascorrimento ha portato in passato a riunire tutte queste rocce sotto il termine di “evaporiti triassiche”. infine i dati cronologici diretti (analisi polliniche) e indiretti (presenza di clasti di rocce con metamorfismo alpino, assenza nelle pseudocarniole di deformazione e metamorfismo alpino) raccolti concorrono nell’indicare che il processo evolutivo delle pseudocarniole appare svolgersi in un intervallo di tempo in genere ampio, diverso da una facies all’altra e inquadrabile tra un limite massimo inferiore rappresentato dal post-oligocene ed il presente, in cui la rielaborazione carsica pleistocenica rappresenta molto spesso il processo più importante nella impostazione dell’aspetto attuale. la genesi delle pseudocarniole si colloca quindi in un periodo decisamente recente e assai distante dal triassico. 9. bibliografia alberto w., carraro f., giardino m., martinotti g., sassone p. & tiranti d. (2004) segnalazione di sinkholes a vari stadi di evoluzione nelle alpi occidentali. 1° seminario: stato dell’arte sullo studio dei fenomeni di sinkholes e ruolo delle amministrazioni statali e locali nel governo del territorio, apat, roma 20-21 maggio 2004. allenbach b. (1982) géologie de la bordure sw du massif d’ambin (alpes occidentales). lithostratigraphie des séries mésozoïques. analyse tectonique et modélisation de la déformation. thèse de 3e cycle, pp. 149. allenbach b. & caron j.m. (1986) relations lithostratigraphiques et tectoniques entre les séries mésozoïques de la bordure sud-ouest du massif d’ambin (alpes occidentales). eclogae geol. helv., 79; 75-116. amieux p. & jeanbourquin p. (1989) cathodoluminescence et origine diagénétique tardive des cargneules du massif des aiguilles rouges (valais, suisse). bull. soc. géol. france, 8-1, 123-132. borghi a. & gattiglio m. (1997) osservazioni geologico-petrografiche nel settore occidentale del massiccio d’ambin. atti tic. sc. terra, 5, 64-84. bruckner w. (1941) uber die entstehung der rauhwacken und zellendolomite. eclogae geol. helv., 34, 117-134. callegari e., sacchi r., bovo s. & torassa g. (1980) osservazioni strutturali sul versante italiano del massiccio d’ambin (alpi graie). boll. soc. geol. it., 99, 395-404. carraro f. & martinotti g. (1993) “deformazioni gravitative profonde di versante” indotte da fenomeni di dissoluzione profondi. iv seminario del gruppo informale del cnr “deformazioni gravitative profonde di versante”, pergola (la verna), 24-28 maggio 1993. d’argenio b. & ferreri v. (1987) a brief outline of sedimentary models for pleistocene travertine accumulation in southern italy. rend. soc. geol. it., 9, 167-170. debelmas j., gidon m. & kerckhove c. (1980) idées actuelles sur les cargneules alpines. livre jubilaire jacques flandrin. docum. lab. géol. fac. sci. lyon. h.s. 4, 195-201. debenedetti a. (1988) karstification, glaciation and atmospheric co2. atti acc. lincei rend. fis., (8), lxxxii, 313-318. debenedetti a. & turi b. (1975) carniole della valle d’aosta studio isotopico ed ipotesi genetica. boll. soc. geol. it., 94, 1883-1894. dela pierre f., lozar f. & polino r. (1997) l’utilizzo della tettonostratigrafia per la rappresentazione cartografica delle successioni metasedimentarie nelle aree di catena. mem. soc. geol., 49, 196206. ellenberger f. (1954) réunion extraordinaire de la société géologique de france en maurienne et tarentaise (savoie). c.r. somm. soc. géol. 199proposta di classificazione delle ... france, 454-458. enel (1981) elementi di neotettonica del territorio italiano. carte tematiche e relazione. alma, milano. federici p.r. & raggi g. (1974) brecce sedimentarie e rapporti tra le unità tettoniche toscane nel gruppo delle alpi apuane. boll. soc. geol. ital.,92, 435452. fioraso g. (1993) ricostruzione dell’evoluzione del versante destro della media valle di susa nel tratto compreso tra exilles e gravere. tesi di laurea ined. univ. torino, 125 pp. fudral s. (1998) etude géologique de la suture téthysienne dans les alpes franco-italiennes nord occidentales de la doire ripaire (italie) à la réegion de bourg saint-maurice (france). géol. alpine, mémoire hs n° 29, 306 pp. fusetti e. (2002) studio geologico sulle deformazioni gravitative profonde del settore ossolano tra crodo, baceno e varzo (verbania, piemonte, italia). geol. insubrica, 6, 1. gay m. (1971) le massif d’ambin et son cadre de schistes lustrés (alpes franco-italiennes). thèse, pp. 296. giardino m. (1995) analisi di deformazioni superficiali: metodologie di ricerca ed esempi di studio nella media valle d’aosta. tesi di dottorato. consorzio universitario di torino-cagliari, genova, 236pp. giardino m. & polino r. (1997) le deformazioni di versante nell’alta valle di susa: risposta pellicolare dell’evlozione tettonica recente. il quaternario, 10 (2), 31-38. grandjacquet c. & haccard d. (1973) mise en évidence de la nature sédimentaire et de l’age néogène de certaines séries de “cargneules et gypses” des chaines subalpines meridionales; implications structurales. c.r. acad. sci. paris, 276, 23692372. grandjacquet c. & haccard d. (1975) analyse des sédiments polygéniques néogènes à faciès de cargneules associés à des gypses dans les alpes du sud. extension de ces faciès au pourtour de la méditerranée occidentale. bull. soc. géol. france (7), 17/2, 242-259. jeanbourquin p. (1986) les cornieules polymictes des préalpes internes et de l’autochtone helvétique en suisse romande. thèmes choisis liés aux cornieules en général. thèse univ. lausanne. jeanbourquin p. (1988) nouvelles observations sur les cornieules en suisse occidentale. eclogae geol. helv., 81-2, 511-538. leine l. (1968) rauhwackes in the betic cordilleras, spain. thèse univ. amsterdam. leine l. (1971) rauhwacken und ihre entstehung. geol. rdsch. 60, 488-524. lomagno p. (1992) miniere e cave in valle di susa. segusium, 33, 105-118. lorenzoni s. (1965) studio geo-petrografico del versante italiano del massiccio d’ambin. mem. ist. geol. min. univ. padova, 25, 25-88. marshall d.j. (1988) cathodoluminescence of geological materials. unwin-hyman, 146 pp., boston. masson h. (1972) sur l’origine de la cornieule par fracturation hydraulique. eclogae geol. helv., 65/1, 27-41. müller w.h. (1982) zur entsthung der rauhwacke. eclogae geol. helv., 75/3, 481-494. patacca e., rau a. & tongiorgi m. (1973) il significato geologico della breccia sedimentaria poligenica al tetto della successione metamorfica dei monti pisani. atti soc. tosc. sci. nat. mem., a 80, 126161. polino r., dela pierre f., fioraso g., giardino m., gattiglio m. (2002) foglio 132-152-153 “bardonecchia” carta geologica d’italia, scala 1:50.000. servizio geologico d’italia. richards m.t. & vearncombe j.r. (1984) sur l’origine des faciès de cargneules et de brèches rencontrés dans une coupe du trias de la vésubie, alpesmaritimes, france. géol. méditerr., 11/3, 283-286. schardt h. (1906) note sur la valeure de l’erosion souterraine par l’action de source. bull. soc. belge geol., 20, pp. 86-94. vearncombe j.r. (1982) the tectonic significance of triassic dolomite and cargneule in the gran paradiso region, western alps. geol. mag., 119 (3), 49-72. warrack m. (1974) the petrology and origin of dedolomitised, veined or brecciated carbonate rocks, the “cornieules” in the fréjus region. french alps. quart. j. geol. soc. london 130, 229-247. wiesender h. (1971) klassifikation und entstehung terrigener und karbonatischer sedimentgesteine. mitt. geol. ges. wien, 64, 219-236. 200 ms. ricevuto il 20 ottobre 2002 testo definitivo ricevuto il 17 febbraio 2003 ms. received: october 20, 2002 final text received: february 17, 2003 w. alberto et al. available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 30 (2), 2017, iii-iv in the last two decades, a number of investigations has brought significant advances in the definition of the stratigraphy and chronology of this crucial portion of the upper pleistocene in the italian alps and piedmont alluvial basins. the aiqua workshop, sponsored by the terpro and saccom inqua commissions and by the igg-cnr and the department of geosciences of the university of padova, was held at the department of geosciences of padova, on june 22 nd -23 nd , 2017 (scientific and organizing committee: p. mozzi, g. monegato, a. fontana, s. rossato). it was attended by about 60 participants. the main aim of the workshop was to provide a comprehensive, state-of-the-art framework of the geomorphic, sedimentary and palaeoenvironmental events that occurred in this key area, which is located at the critical transition between continental europe and the mediterranean region. the presence of longinvestigated upper palaeolithic sites in the italian subalpine region also rises stimulating questions on the interaction between early humans and extreme environmental conditions and landscapes of the last glaciation. hot topics discussed during the workshop were: the onset, phases and termination of the alpine lgm sediment production and delivery from glacial and periglacial areas to the basin piedmont and in-valley terminal glacial tongues lgm and late glacial climates and environments dating methods and integrated chronologies territories and settlements of the upper paleolithic hunter-gatherers. the workshop was articulated in a first day of solicited talks, which embraced some major issues on the last glaciation in the italian side of the alps: the alpine glacial systems (g. monegato) and related megafans (a. fontana, p. mozzi, s. rossato), the po river lowstand wedge (c. pellegrini, a. asioli, k.m. boahcs, t.m. drexler, m.l. sweet, v. maselli, m. rovere, t. tesi, f. gamberi, g. dalla valle, f. trincardi), the lgm and lateglacial stadials in the fig. 1 participants of the aiqua field trip on the terminal moraines of the piave glacier at quero (photo by f. finocchiaro). aiqua workshop: updates on the chronology, stratigraphy and environments of the last glacial maximum and the late glacial on the southern side of the alps paolo mozzi 1 , giovanni monegato 2 corresponding author: p. mozzi <paolo.mozzi@unipd.it> 1 dipartimento di geoscienze, padova, italy 2 cnr igg, torino, italy abstract: the aiqua workshop, sponsored by the terpro and saccom inqua commissions and by the igg-cnr and the department of geosciences of the university of padova, was held at the department of geosciences of padova, on june 22 nd -23 nd , 2017 (scientific and organizing committee: p. mozzi, g. monegato, a. fontana, s. rossato). the workshop focused on the geomorphic, sedimentary and palaeoenvironmental events that occurred in the southern alpine region and related po plain, venetian-friulian plain and adriatic basin during the last glacial maximum and the late glacial. about 60 participants attended the workshop, with nine solicited talks, five short communications and posters, and ample time devoted to discussion. the second day consisted in a field trip in the venetian prealps. keywords: last glaciation, last glacial maximum, late glacial, alps, italy iv mozzi p. & monegato g. maritime alps (a. ribolini m. spagnolo, p.r. federici), the speleothem record in the eastern italian alps (a. borsato, r. belli, s. frisia, j. hellstrom), ecosystems and environments (c. ravazzi, r. pini, f. vallè), loess deposition in the po plain (a. zerboni, m. cremaschi), paleolithic settlements between the apennines and the prealps (m. peresani), and rock glacier evolution in the alps (r. colucci, m. guglielmin). time was also devoted to short presentations and posters by the participants, concerning glacigenic landforms and deposits in the ivrea end-moraine system (gianotti et al.), slovenian alps (žebre et al.) and julian alps (finocchiaro et al.), as well as loess in the ligurian alps (rellini et al.) and a review of the mammuthus-coelodonta faunal complex in italy during the last glaciation (menicozzi et al.). at the end of the presentations, it followed a plenary discussion on the timing of landscape evolution and palaeoecosystems from the adriatic plain to the alps during the last glacial maximum and the late glacial on the second day there was a field trip in the venetian prealps, led by p. mozzi, g. monegato and s. rossato. this excursion was centered on glacier arrival, acme and decay in the terminal tracts of the brenta and piave valleys, and the related dynamic response of the glaciofluvial system. the first stop concerned the piave river terraces around biadene, then we moved to quero, where we visited the lgm end-moraine system of the piave glacier. after lunch, we visited the arsiè-cismon area, where we observed the moraines of the brenta glacier and related glaciofluvial deposits. ms. received: december 15, 2017 final text received: december 24, 2017 fig. 2 view on the terminal tract of the piave valley from the lgm terminal moraines of quero (photo by s. rossato). fig. 3 upper pleistocene fluvial deposits of the piave river in the montebelluna megafan (caravaggio gravel pit) (photo p. mozzi). fig. 4 polygenetic lgm glaciofluvial deposits of the brenta river in the valsugana valley (cismon del grappa) (photo p. mozzi). amq104 mecozzi et al 3 compresso.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 33 (1), 2020, 89-98 cuon alpinus (pallas, 1811) from the late pleistocene site of ingarano (foggia, southern italy) and insights on the eurasian middle to late pleistocene record. beniamino mecozzi 1, 2, saverio bartolini lucenti 3, 4, dawid adam iurino 2 1 dipartimento di scienze della terra, università di roma sapienza, roma, italy. 2 paleofactory, università di roma sapienza, roma, italy. 3 dipartimento di scienze della terra, paleo[fab]lab, università degli studi di firenze, firenze, iitaly. 4 museo di storia naturale, sez. geologia e paleontologia, università degli studi di firenze, firenze, italy. corresponding author: saverio bartolini lucenti <saverio.bartolinilucenti@unifi.it> abstract: in this study, we report for the first time the presence of cuon alpinus from the late pleistocene site of ingarano (foggia, southern italy), represented by an right upper first molar. considering the intricate and debated taxonomy of fossil dholes, our comparative analyses on dental samples (p4, m1, and m1) of the extant and middle to late pleistocene dholes from europe, has been performed evidencing a relevant degree of morphological variability and a biometric uniformity of the considered teeth. our results indicate the lack of clear morphological and biometric features for a reliable teeth-based classification of fossil dholes, questioning the validity of the fossil taxa currently proposed in the literature. finally, to avoid the propagation of taxonomically questionable species, we suggest to refer all the middle to late pleistocene material to cuon alpinus. keywords: canidae, carnivorans, dhole, biochronology, biometry, teeth.   1. introduction cuon alpinus (pallas, 1811), known as dhole, is a medium-sized social canid currently widespread in most of southeastern asia including the western islands of indonesia (durbin et al., 2004; wilson & mittermeier, 2009; castelló, 2018). morphological and biometric data led mivart (1890) to distinguish two extant species of cuon, the northern dhole (c. alpinus) and the southern dhole (c. javanicus). on the contrary, ellerman & morrison-scott (1966) reunited the diversity of the dhole under a single specific name, identifying 11 subspecies on the basis of their external features (e.g., differences in coat length, color pattern) (castelló, 2018). genetic analyses confirmed ellerman and morrison-scott’ hypothesis, finding no clear specific distinction, although such works only took into consideration populations from the southern part of the dhole distribution (e.g., iyengar et al. 2005). wilson & mittermeier (2009) grouped all these subspecies under only three, c. alpinus alpinus, c. alpinus hesperius, c. alpinus sumatrensis. therefore, there is a general consensus in considering the genus cuon as monospecific, although the validity of the different subspecies is still debated. the dhole is an active predator that lives in large packs, characterized by several dental features related to a hypercarnivorous diet (van valkenburg, 1991), such as the slicing premolars, the single-cusped talonid of the lower carnassials, the reduction or even the absence of the second upper molar and the lack of the lower third molar. except for this latter character, peculiar of the genus cuon, the hypercarnivorous dentition is shared with the extant genera lycaon and speothos (thenius, 1954; van valkenburg, 1991) and the fossil xenocyon. whereas today the species is confined to asia, at the beginning of the middle pleistocene the dhole was widespread across eurasia reaching western europe (garcía garcía, 2003) and north america in the late pleistocene (tedford et al., 2009). such a wide geographical distribution is a common ecological trait of the middle-late pleistocene canids as documented for canis mosbachensis and canis lupus (sardella et. al., 2014; bartolini lucenti et al., 2017; 2020; mecozzi et. al., 2017, 2020), both characterized by a large intraspecific variability and thus considered as polymorphic species. fossil remains of dhole are exceptionally scarce and mainly represented by isolated teeth, fragmented cranial remains and few postcranial elements (perezripoll et al., 2010). consequently, the morphological and biometric variability of these carnivorans throughout the middle and late pleistocene is poorly known, fueling the debate on its origin and evolution (brugal & boudadimaligne, 2011, petrucci et al., 2012; ghezzo & rook, 2014). here, we offer a comparative study of selected teeth (p4, m1 and m1) of extant and fossil dholes, including the well preserved right m1 belonging to the first cuon alpinus reported from the late pleistocene site of ingarano. https://doi.org/10.26382/amq.2020.08 90 mecozzi b. et al. 1.1. taxonomy of the european fossil dholes in the last quarter of the xix century, in europe several taxa have been ascribed to the genus cuon (c. alpinus fossilis, c. alpinus pyrenaicus, c. bourreti, c. europaeus) (tab. 1). thenius (1954) erected the species cuon priscus on the basis of the large-sized specimens from hundsheim (austria). furthermore, the author introduced the subspecies c. dubius stehlini for the fossils from rosières (france), suggesting similarities with the chinese c. dubius described by teilhard de chardin (1940). nowadays, the species “c. dubius” is commonly referred to the genus xenocyon (schütt, 1973; tedford et al., 2009) or even the transitional sinicuon (wang et al., 2014). the form “c.” stehlini is now referred to lycaon/xenocyon lycaonoides (rook, 1994; martínez-navarro & rook, 2003, sotnikova & rook, 2010). similarly, the species cuon rosi from cueva victoria described by pons-moyá & moyá-solá (1978) is widely considered as lycaon/xenocyon lycaonoides (madurell-malapeira et al., 2013). the reason for this confusion between the pleistocene remains of european dholes and those of genus lycaon/xenocyon lies in the similar development of several dental features. adam (1959) attempted to reconstruct the affinities and taxonomy of european cuon, suggesting the division of the european remains in three subspecies, all part of a single phyletic line: c. a. priscus c. a. fossilis c. a. europaeus. bonifay (1971) considered valid three species for the middle pleistocene of europe: c. stehlini, c. priscus and c. alpinus (the latter furtherly diversified into two subspecies, c. alpinus fossilis and c. alpinus europaeus). the subspecies c. alpinus caucasicus was erected by baryshnikov (1978) on the basis of the late pleistocene fossil remains from various localities of the transcaucasian region (kudaro 1, kudaro 3, tsona cave). recently, brugal & boudadi-maligne (2011) revised the scheme proposed by bonifay (1971) acknowledging three taxa for the pleistocene fossil record of europe: c. priscus, c. a. fossilis and c. a. europaeus. as mentioned above, the first occurrence of c. priscus has been reported from the early middle pleistocene site of hundsheim (austria) (thenius,1954). afterwards, this species has been documented until the middle pleistocene in some localities e.g., lunel-viel (france) (bonifay, 1971), caune de l’arago (france) (bonifay, 1971), galeria pesada (portugal) (trinkaus et al., 2003). during the late middle pleistocene, the first occurrence of another species of dhole, c. alpinus, has been reported from the late middle pleistocene site of trinchera galeria in spain (garcìa garcìa & arsuaga, 1997; garcìa garcìa, 2003). this taxon probably replaced c. priscus becoming part of the carnivoran guild for all the late pleistocene tab. 1 list of the fossil and extant (sub)species of cuon. * indicates extant subspecies listed in wilson & mittermeier (2009). fossil species are marked by † symbol. fig. 1 geographic position of the ingarano: a) map of italy; b) zoom of the promontory of gargano (image taken from googleearth). 91 until the early holocene, as reported from the riparo fredian site (italy) (cilli et al., 1998) and les coves de santa maira (spain) (pérez-ripoll et al., 2010). 1.3. the site of ingarano the palaeontological site of ingarano (foggia, southern italy) is located in the north-western area of the gargano’s promontory (fig. 1). the deposit is a karstic filling succession within the jurassic-cretaceous limestone (petronio et al., 1996; petronio & sardella, 1998; bedetti & pavia, 2007) dated with the 238u/234th method (tab. 2). a number of studies focused on the description of the rich vertebrate fauna of ingarano site (levels b-e, fig. 2) (capasso barbato et al., 1992; petronio et al., 1996; petronio & sardella, 1998; curcio et al., 2005; bedetti & pavia, 2007; iurino, 2014; iurino & sardella, 2015; iurino et al., 2015), including 41 species, listed below: amphibians: rana sp.; reptiles: lacerta sp.; birds: circus aeroginosus, aquila chrysaëtos, falco cherrug, falco columbarius, alectoris graeca, perdix perdix, columba livia, nyctea scandiaca, pyrrhocorax graculus, pyrrhocorax sp., corvus corone, corvus corax; mammals: erinaceus europaeus, myotis blythi, oryctolagus cuniculus, lepus europaeus, arvicolidae indet., microtus sp., microtus ex gr. arvalis/agrestis, terricola savii, apodemus sylvaticus, eliomys quercinus, canis lupus, vulpes vulpes, ursus arctos, mustela nivalis, martes sp., meles meles, gulo gulo, crocuta crocuta, felis sp., lynx lynx, panthera pardus, equus hydruntinus, cervus elaphus, dama dama, capreolus capreolus, rupicapra sp., bos primigenius. the faunal assemblage was deposited in a short time-span, chronologically referred to mis 3 (bedetti & pavia, 2007). the talus, a deposit of unclear stratigraphical interpretation found near the sedimentary succession, is rich in vertebrate remains, including panthera spelaea, hippopotamus amphibius, coelodonta antiquitatis, stephanorhinus hemitoechus and palaeoloxodon antiquus. no fossil remains of these taxa have been recovered from the levels b-e. up to now, the remains of medium-sized canid have been attributed to canis lupus (petronio et al., 1996; petronio & sardella, 1998; bedetti & pavia, 2007). 2. materials and methods the specimen ingnd59 representes a right upper first molar and it is currently housed in the paleofactory laboratory, department of earth sciences, at the sapienza university of rome. comparative fossil samples include: specimens of san sidero, housed in the paleofactory laboratory, department of earth sciences, sapienza university of rome; those of “grotta” and “tecchia di equi”, housed in the collection of the geology and paleontology section of the natural history museum of the university of florence; and specimens of wanxian housed in the vertebrate paleontology collections of the american museum of natural history (amnh, new york, u.s.a.). the taxon from wanxian was previously referred to c. antiquus by matthew & granger (1923) but currently is considered a junior synonym c. alpinus, see among others castelló fig. 2 fossiliferous site of ingarano: a) schematic log of the stratigraphic succession; b) sedimentary succession. tab. 2 radiocarbon dating of speleothem and phosphathic material from the site of ingarano (modified from petronio et al., 1996). cuon alpinus (pallas, 1811) from ingarano (foggia, southern italy) and insights on the eurasian middle to late pleistocene record 92 mecozzi b. et al. fig. 3 variability of m1 in extant and fossil cuon. a–d) cuon alpinus from ingarano, ingnd59, right m1; a) buccal view; b) lingual view; c) occlusal view; d) schematic outline of the occlusal morphology of ingnd59. e–g) extant cuon alpinus; e) amnh 102083; f) ioz 26747 (tong et al., 2012); g) cuon alpinus hesperius afanasjev & zolotarev, 1935, holotype, zin 23894, zoological institute of russian academy of science. h–l) fossil cuon. h) cuon alpinus, amnh 18391 (reversed), wanxian (china); i) cuon alpinus, amnh 18727 (reversed), wanxian (china); j) cuon alpinus europaeus bourguignat 1875, obarreta (portugal, from perez-ripoll et al., 2010); k) cuon priscus thenius, 1954, holotype from hundsheim (germany, from thenius, 1954); l) cuon alpinus caucasicus baryshnikov, 1978, kudaro (from baryshnikov, 2012). (2018) (tab. 1). data on the extant c. alpinus were taken on the specimens of the comparative anatomy amnh (new york, u.s.a.). following driesch (1976), we measured the length (l) and breadth (b) of the p4, m1 and m1. the measurements were taken to the nearest 0.1 mm with a digital caliper. we used literature data on fossil dhole from the middle to late pleistocene of austria, czech republic, slovakia, france, germany, greece, italy, spain, hungary and caucasian region (see supplementary material, tab. s1). the specimens from romain la roche, mosbach and petralona have not been considered for biometric and morphological analyses as we exclude their attribution to the genus cuon (see discussion). following brugal & boudadi-maligne (2011), we consider the european fossil sample belonging to two taxa, c. priscus from the early to late middle pleistocene and c. alpinus from the late middle to late pleistocene (tab. s1). the dataset was tested for normality distribution verification using shapiro-wilks test. as the dental variables resulted normally distributed, we performed a statistical parametric test. differences in p4l, m1l, and m1l of the middle to late pleistocene specimens of europe was evaluated using linear model with corner point parameterization testing the null hypothesis of nodifferences between the mean of c. priscus and the other sample of middle and late pleistocene c. alpinus and extant c. alpinus (p.value > 0.05). the statistical analysis was performed using the r software (r core team, 2019). 3. systematic palaeontology family canidae fischer, 1817 genus cuon hodgson, 1838 cuon alpinus (pallas, 1811) 3.1. description ingnd59 is an almost complete right m1 missing part of the labial root (fig. 3a-c). the crown is slightly worn and slightly wrapped by a crust formed by the clay matrix with calcite cementum. in occlusal view, the m1 is buccolingually short. it possesses an enlarged paracone compared to the slightly shorter metacone. these cusps appear to be fused medially. in occlusal view, the buccal cingulum is not prominent and it is only marked at the level of the parastyle. the trigon basin is wide, round and deep, mesially girdled by a stout and large proto 93 cuon alpinus (pallas, 1811) from the late pleistocene site of ingarano (foggia, southern italy) and insights on the eurasian middle to late pleistocene record cone. the post-protocrista distally shows a very reduced and barely visible metaconule. the talon basin is vestigial and a cingulum, although it is partially broken, lies lingually. the mesial cingulum is feeble. the embayment on the distal side of the tooth is rather reduced. 3.2. morphological comparison the fusion of the paracone and the metacone, as well as the development of the buccal cingulum of ingnd59, resemble the condition observed in: c. priscus from hundsheim (thenius, 1954), c. alpinus caucasicus from caucasus (kudaro, baryshnikov, 1996), c. alpinus europaeus from spain (e.g., obarreta, peréz-ripoll et al., 2010) and in those from italian area of melpignano and san sidero (petrucci et al., 2012; iurino et al., 2013) (fig. 3). the morphology of the lingual portion of the m1 has a high degree of intraspecific variability (also at individual level, see altuna, 1983). in occlusal view, the lingual portion of the ingnd59 has a round and expanded outline similar to those of the specimens from hundsheim (thenius, 1954) (fig. 3k), wanxian (“wan hsien”, sichuan, china; colbert & hooijer, 1953) (fig. 3h-i), trinchera galeria (garcía garcía, & arsuaga, 1997), and different from that of other fossil and extant samples (e.g., kudaro) (fig. 3l) for their reduction of the distolingual lobe. a peculiar feature of the m1 from ingarano is the relative enlargement of the lingual portion compared to the buccal one. this morphology contrast with that observed in extant cuon where generally the lingual side of the tooth is mesiodistally compressed (fig. 3). 3.3. biometric comparison the results of the statistical analysis reveal slight differences in the dental traits (fig. 4). in extant dhole, the range of the p4l includes all the values of the fossil specimens, which are very similar to each other as the median of c. priscus reaches the maximum value of the extant dhole. the length and breadth of the p4 in c. priscus do not differ significantly from the other groups (p.values > 0.05) (fig. 4a-b; tab. 3). the middle pleistocene forms possess longer m1 compared to the other groups, but its breadth is significantly lower than those of c. priscus and the late pleistocene c. alpinus (fig. 4d). similarly, the m1b of c. priscus is larger compared to the middle pleistocene c. alpinus (fig. 4c-d; tab. 3). whereas the m1l of c. priscus statistically differs from those of the late pleistocene c. alpinus and the extant c. alpinus, no differences can be found in the breadth (fig. e-f; tab. 3). tab. 3 table of p-values of linear model, cuon priscus used as corner point. 94 mecozzi b. et al. fig. 4 boxplot of the length (a) and breadth (b) of p4, the length (c) and breadth (d) of m1 and the length (e) and breadth (f) of m1 of middle and late pleistocene cuon alpinus and extant cuon alpinus. be the reason of the proliferation of the fossil species/ subspecies/varieties of cuon (brugal & boudadimaligne, 2011) (tab. 1). the tooth from ingarano falls in this range of morphologies although its lingual portion is among the widest of the considered sample. a certain degree of teeth variability among the italian record of fossil cuon has been reported by petrucci et. al. (2012), where the authors highlighted how the shape and the occlusal surface of the m2 change in all the italian specimens. a similar variability of the m2 in extant and fossil dhole has been reported also by brugal & boudadimaligne (2011). according to mivart (1890) and durbin et al. (2004) the m2 variability documented in extant dhole would be linked to the latitudinal distribution, but for a more exhaustive explanation of such a teeth diversification a larger sample of fossil specimens is needed. the eurasian fossil record of the dhole is mainly represented by isolated or fragmentary cranio-dental elements, whereas postcranial bones and partially complete crania are exceptionally rare, which explains why 4. discussion according to our results, the specimen ingnd59 is morphologically and biometrically compatible with the m1 of extant and fossil dhole, thus representing the first report of this carnivoran from the site of ingarano. despite the fact that the remains of cuon are poorly documented and both geographically and chronologically dispersed, our morphological comparison has evidenced a quite large variability of the buccal and lingual profile of the m1 among the considered samples, especially the cuspule-like postprotocrista distal to the metacone and both the buccal and distal notches (fig. 3c-d). this variability would not appear to be taxon-related as the extant forms include almost all the range of features observed in the fossil samples, as exemplified by the three different m1 morphotypes identified in the extant dhole specimens (fig. 3e-g). along with other variable dental features (e.g., the development of cuspulid-like lingual portion of the m1 talonid), these subtle differences, might 95 ms. received: july 10, 2020 final text received: september 08, 2020 fig. 5 length variation of the p4, m1 and m1 of the european fossil cuon from the middle pleistocene to the present days. middle pleistocene: 1) la caune de l'arago, 2) lunel viel, 3) hundsheim, 4) heppenloch; late pleistocene: 5) trinchera galeria; late pleistocene: 6) repolust hole, 7) chokier, 8) certova dira, 9) sipka, 10) ceverne mars/vence, 11) fontechevade, 12) grotte de cotencher, 13) grotte de la carrière, 14) grotte de l'observatoire, 15) grotta vaufrey, 16) isturitz, 17) la niche, 18) malarnaud, 19) moula guercy, 20) verze, 21) offenberger hole, 22) melpignano, 23) san sidero, 24) buca del tasso, 25) canale mussolini, 26) equi, 27) ingarano, 28) valserra, 29) almada, 30) bolinkoba, 31) boquete de zafarraya, 32) cova negra, 33) duranguesado, 34) la riera, 35) moros de gabasa, 36) obarreta, 37) parpallò, 38) kudaro, 39) extant. cuon alpinus (pallas, 1811) from ingarano (foggia, southern italy) and insights on the eurasian middle to late pleistocene record the taxonomy of this carnivoran is principally based on teeth. moreover, biometric data as the size of the lower carnassial, were considered as good parameters to discriminate the dhole from other canidae (ghezzo & rook, 2014) or to distinguish between the fossil samples and to recognize different taxa (brugal & boudadimaligne, 2011). nevertheless, up to now no statistical analyses were performed to support these hypotheses. the results of our study carried out on the p4, m1 and m1, reveal that size differences among the extant and fossil samples are very small, with weak, if any, statistical significance (fig. 4, tab. 3). differences can be found only in some variables without any consistent evidence of distinction between the known taxa. for instance, the m1 length of the middle pleistocene c. alpinus reaches the highest values of the sample whereas the m1 breadth is larger in c. priscus and in the late pleistocene c. alpinus. in general, the variability of the fossil groups is mostly included in that of the extant species, suggesting a biometric uniformity of the teeth size from the middle pleistocene to recent times. this contrasts with the hypothese put forward by adam (1959), with three recognized forms (c. alpinus priscus, c. alpinus fossilis, c. alpinus europaeus in adam 1959) based on the supposed trend of size decrease in the m1 length. such idea was confirmed by brugal & boudadi maligne (2011). these authors separated the middle pleistocene apparently larger forms (c. priscus) from the late pleistocene ones (c. alpinus) on the basis of teeth size. the authors included among the middle pleistocene forms the samples from mosbach, petralona and hundsheim, which are indeed characterized by larger teeth (tab. s1). nevertheless, it should be noted that the specimen of mosbach was considered by adam (1959) as cuon priscus, but this material has not been described. schütt (1974) ascribed the mosbach specimen to xenocyon lycaonoides for the retention of the m3 in the hemimandible. similarly, the left hemimandible from petralona (kp no 205) was originally described by kurtèn & poulianos (1977) as belonging to c. priscus. the authors remark that the hemimandible is partially covered by a stalagmite crust, especially in the molar area, which prevents the acquisition of any biometric or morphological data of the m2 and on the presence/absence of the m3. therefore, the classification was carried out without considering these characters. more recently, baryshnikov & tsoukala (2010) revised the fossil collection from petralona stored at the aristotle university of thessaloniki, identifying three canid taxa: canis arnensis, vulpes praeglacialis and lycaon lycaonoides (=xenocyon lycaonoides). in the latter, the authors also included the remains previously classified as cuon priscus by kurtèn & poulianos (1977) into l. lycaonoides (baryshnikov & tsoukala, 2010: 392). another questionable attribution to cuon is that of a largesized specimen from romain la roche (can.1069) described by argant (2010). the latter scholar reported the presence of the m3 alveolus, yet there is a wide consensus among researchers in considering the absence of this tooth as one of the principal diagnostic characters to typify the genus cuon from other canids (schutt, 1973; tedford et al., 2009). on such basis, the 96 mecozzi b. et al. attribution of this specimen to cuon alpinus is excluded and a more parsimonious attribution to canis lupus could be suggested. according to this taxonomic clarification, we excluded the specimens from mosbach, petralona and romain la roche from our biometric analysis, evidencing the inconsistency of the timerelated reduction of the teeth in european fossil dholes proposed by adam (1959) and brugal & boudadì malgine (2011). indeed, size of the teeth seems to be uniform from the middle pleistocene to the present days (figs. 4-5; tab. s1), questioning the taxonomic reliability of the fossil specimens currently proposed in literature. in sum, our results indicate the lack of clear morphological and biometric features for a reliable classification of the european fossil dholes, especially if based on teeth. therefore, to avoid the proliferation of taxonomically questionable species, we suggest to consider all the middle to late pleistocene material as cuon alpinus. 5. conclusion the revision of the palaeontological collection from ingarano allow us to identify for the first time the presence of c. alpinus in this late pleistocene site, enriching its carnivorans guild. this makes the ingarano deposit one of the richest late pleistocene italian sites in carnivorans, where also the occurrence of c. lupus is documented. the results of this work show that some pleistocene specimens that cuon has been often confused with other hypercarnivorous taxa (e.g. c.lupus or xenocyon spp.), thus confusing its taxonomic determination. especially size was a feature historically used as the discrimination factor between different species/ subspecies. our analyses point out that no significant difference really exists between middle and late pleistocene forms. this dimensional uniformity, at least in teeth size, contrasts with the evidence on other canids with a rather more conspicuous record (e.g., c. mosbachensis or c. lupus, among others sansalone et al., 2015; mecozzi et al., 2020) which experienced several shifts in size during glacial/interglacial phases (mecozzi & bartolini lucenti, 2018). if this could be related to the bias of the record (i.e. its scarcity) or to the paleodietary and paleoecological aspects of these canids, are among the questions that still need to be answered. in the meantime, considering 1) the present knowledge of the fossil cuon, 2) its scarce record in the middle-late pleistocene of europe, 3) its extant variability in morphology; our results favour the inclusion of the whole middle-late pleistocene fossil record under the specific name of cuon alpinus, rather than in two or more different (chrono) species. despite this, we do not exclude that future studies based on new and more complete craniodental remains and better performing methodologies, may demonstrate the presence of additional fossil taxa. acknowledgements the authors are thankful to prof. lorenzo rook and prof. raffaele sardella for their support and advice. the authors thank dr. e. cioppi of natural history museum of university of florence, j. galkin and dr j. meng of the vertebrate paleontology collection of the american museum of natural history (new york) for access to the collections. bm and dai wish to thank “fondi grandi scavi sapienza 2019 (sa11916b513e7c4b), 2020 (sa120172b2c05e68). we are grateful for the insightful comments of prof. b. martinez-navarro and an anonymous reviewer. references adam k.d. (1959) mittelpleistozäne caniden aus dem heppenloch bei guttemberg (württemberg). stuttgarter beitrage zur naturkunde a, 27,1-46 . altuna j. (1983) hallazgo de un cuon (cuon alpinus pallas) en obarreta, gorbea (vizcaya). kobie, 13, 141-157. bartolini lucenti s., alba d.m., rook l., moyà-solà s., madurell-malapeira j. (2017) latest early pleistocene wolf-like canids from the iberian peninsula. quaternary science reviews, 162,12-25. bartolini lucenti s., bukhsianidze m., martínez-navarro b., lordkipanidze d. (2020) the wolf from dmanisi and augmented reality: review, implications and opportunities. frontiers in earth science, 8, 131. baryshnikov g. (1996) the dholedhole, cuon alpinus (carnivora, canidae), from the upper pleistocene of the caucasus. acta zoologica cracoviense, 39 (1), 67-73. bedetti c., pavia m. (2007) reinterpretation of the late pleistocene ingarano cave deposit based on the fossil bird associations (apulia, south-eastern italy). rivista italiana di paleontologia e stratigrafia, 113, 487-507. bonifay m.f. (1971) carnivores quaternaires du sudest de la france. mémoire du musée national histoire naturellede lyon, serie c, 21,145-153. brugal j.-p., boudadi-maligne m. (2011) quaternary small to large canids in europe: taxonomic status and biochronological contribution. quaternary international, 243(1),171-182. castelló j.r. (2018) canids of the world: wolves, wild dogs, foxes, jackals, coyotes, and their relatives (vol. 135). princeton university press, 336. cilli c., malerba g., tozzi c. (1998) analyse archeozoologique et modifications de surface des restes faunique de deux site du paleolithique superior de toscane (italie). atti u.i.s.p.p. 13 (2), 675-679. driesch a. (1976) a guide to the measurement of animal bones from archaeological sites. 137 pp. peabody museum bulletin, 1. durbin l.s., venkataraman a., hedges s., duckworth w. (2004) south asia-south of the hymalaya (oriental). in sillero-zubiri c., hoffmann m., macdonald d., canids: foxes, wolves, jackals and dogs. status survey and conservation action plan (2004), 210-219. ellerman j.r., morrison-scott t.c.s. (1966) checklist of palaearctic and indian mammals 1758 to 1946. british museum (natural history), london, uk, 828. fischer g. (1817) adversaria zoologica. mémoire sociéte imperiale national moscow, 5, 357-446. garcía garcía n. (2003) osos y otros carnìvoros de la sierra de atapuerca. fundaciòn oso de asturias, oviedo, madrid, spain, 575. garcía garcía n., arsuaga j.l. (1997) the carnivore remains from the hominid-bearing trinchera-galeria, sierra de atapuerca, middle pleistocene site (spain). geobios, 31 (5), 659-674. ghezzo e., rook l. (2014) cuon alpinus (pallas, 1811) (mammalia, carnivora) from equi (late pleistocene, massa-carrara, italy): anatomical analysis and palaeoethological contextualisation. rendiconti dell’accademia dei lincei, 25(4), 491-504. iurino d.a., fico r., petrucci m., sardella r. (2013) a pathological late pleistocene canid from san sidero (italy): implications for social-and feeding-behaviour. naturwissenschaften, 100 (3), 235-243. iurino d.a. (2014) body size reduction and tooth agenesis in late pleistocene meles meles (carnivora, mammalia) from ingarano (southern italy). rivista italiana di paleontologia e stratigrafia, 120(1), 109118. iurino d.a., sardella r. (2015) medical ct scanning and the study of hidden oral pathologies in fossil carnivores. paläontologische zeitschrift, 89(2), 251259. iurino d.a., profico a., cherin m., veneziano a., costeur l., sardella r. (2015) a lynx natural brain endocast from ingarano (southern italy; late pleistocene): taphonomic, morphometric and phylogenetic approaches. hystrix, 26(2), 110-117. iyengar a., babu v.n., hedges s., venkataraman b., maclean n., morin p.a. (2005) phylogeography, genetic structure, and diversity in the dhole (cuon alpinus). molecular ecology, 14, 2281-2297. kamler j.f., songsasen n., jenks k., srivathsa a., sheng l., kunkel k. (2015) cuon alpinus. the iucn red list of threatened species 2015, e.t5953a72477893. madurell-malapeira j., rook l., martínez-navarro b., alba d.m., aurell-garrido j., moyà-solà s. (2013) the latest european painted dog. journal of vertebrate paleontology, 33 (5), 1244-1249. martínez-navarro b., rook l. (2003) gradual evolution in the african hunting dog lineage. systematic implications. comptes rendus palevol, 2, 695-702. matthew w.d., granger w. (1923) new fossil mammals from the pliocene of szechuan. china. bulletin of the american museum of natural history, 48,563598. mecozzi b., iurino d.a., bertè d.f., sardella r. (2017) canis mosbachensis (canidae, mammalia) from the middle pleistocene of contrada monticelli (putignano, apulia, southern italy). bollettino della societ. paleontologica italiana, 56(1), 71-78. mecozzi b., bartolini lucenti, s. (2018) the late pleistocene canis lupus (canidae, mammalia) from avetrana (apulia, italy): reappraisal and new insights on the european glacial wolves. italian journal of geosciences, 137(1), 138-150. mecozzi b., iurino d.a., profico a., rosa c., sardella r. 97 cuon alpinus (pallas, 1811) from ingarano (foggia, southern italy) and insights on the eurasian middle to late pleistocene record (2020) the wolf from the middle pleistocene site of ostiense (rome): the last occurrence of canis mosbachensis (canidae, mammalia) in italy. historical biology, 1-12. doi: 10.1080/08912963.2020.1769090 mivart s.g. (1890) dogs, jackal, wolves, and foxes: a monograph of the canidae. r.h. porter, london, pp. 216. pérez ripoll m., morales pérez j.v., sanchis serra a., aura tortosa j.e., sarrión montañana i. (2010) presence of the genus cuon in upper pleistocene and initial holocene sites of the iberian peninsula: new remains identified in archaeological contexts of the mediterranean region. journal of archaeological sciences, 37 (3), 437-450. petronio c., billia e., capasso barbato l., di stefano g., mussi m., parry s.j., sardella r., voltaggio m. (1996) the late pleistocene fauna of ingarano (gargano, italy): biochronological, paleoecological, paleoethnological end geochronological implications. bollettino della società paleontologia italiana, 34, 333-339. petronio c., sardella r. (1998) remarks on the stratigraphy and biochronology of the late pleistocene deposit of ingarano (apulia, southern italy). rivista italiana di paleontologia e di stratigrafia, 104(2), 287-294. petrucci m., romiti s., sardella r. (2012) the middlelate pleistocene cuon hodgson, 1838 (carnivora, canidae) from italy. bollettino della società paleontologica italiana, 51, 137-148. pons-moyá j., moyá-solá s. (1978) la fauna de carnívoros del pleistoceno medio (mindel) de la cueva victoria (cartagena, españa). acta geológica hispánica 13, 2, 54-58. r core team (2019) r language definition. vienna, austria: r foundation for statistical computing. rook l. (1994) the plio-pleistocene old world canis (xenocyon) ex gr. falconeri. bollettino della società paleontologica italiana, 33, 71-82. sardella r., bertè d., iurino d.a., cherin m., tagliacozzo a. (2014) the wolf from grotta romanelli (apulia, italy) and its implications in the evolutionary history of canis lupus in the late pleistocene of southern italy. quaternary international, 328, 179-195. 98 mecozzi b. et al. sansalone g., berte d. f., maiorino l., pandolfi l. (2015) evolutionary trends and stasis in carnassial teeth of european pleistocene wolf canis lupus (mammalia, canidae). quaternary science reviews, 110, 36-48. schütt g. (1973) revision der cuonund xenocyonfunde (canidae, mammalia) aus den altpleistozänen mosbacher sanden (wiesbaden, hessen). mainzer naturwissenschaftliches archiv,12, 49-77. sillero-zubiri c., hoffman m., macdonald d.w. (eds.) (2004) canids: foxes, wolves, jackals and dogs, oxford university press, uk, 210-219. sotnikova m, rook l. (2010) dispersal of the canini (mammalia, canidae: caninae) across eurasia during the late miocene to early pleistocene. quaternary international, 212, 86-97. tedford r., wang x., taylor b. (2009) phylogenetic systematics of the north american fossil caninae (carnivora: canidae). bulletin of the american museum of natural history, 325, 1-218. teilhard de chardin p. (1940) the fossils from locality 18 near peking. paleontologia sinica, series c 9, 194. thenius e. (1954) on the origins of the dholedhole. österreichische zoologische zeitschrift, 5, 377-388. trinkaus e., marks a.e., brugal j.p., bailey s.e., rink w.j., richter d. (2003) later middle pleistocene human remains from the almonda karstic system, torres novas, portugal. journal of human evolution, 45, 219-226. van valkenburg b. (1991) iterative evolution of hypercarnivory in canids (mammalia: canidae): evolutionary interaction among sympatric predators. paleobiology, 17, 340-362. wilson d.e., mittermeier r.a. (2009) handbook of the mammals of the world. vol. 1. carnivores. lynx edicions, barcelona, 423. ms. received: april 28, 2020 revised: september 30, 2020 accepted: november 1, 2020 available online: november 30, 2020 amq88 suc et al proofcopy available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 31 (1), 2018, iii viii the pioneering contributions and legacy of waldo h. zagwijn (1928–2018) jean-pierre suc 1, speranta-maria popescu 2, adele bertini 3, martin j. head 4, philip l. gibbard 5, filomena diniz 6 1 sorbonne université, cnrs-insu, institut des sciences de la terre, paris, france 2 geobiostratdata.consulting, rillieux la pape, france 3 dipartimento di scienze della terra, università di firenze, firenze, italy 4 department of earth sciences, brock university, st. catharines, ontario, canada 5 scott polar research institute, university of cambridge, cambridge, uk 6 departamento de geologia, universidade de lisboa, lisboa, portugal corresponding author: j.-p. suc <jeanpierre.suc@gmail.com> abstract: professor dr. waldo h. zagwijn passed away on 26 june, 2018, in his ninetieth year. his thesis research (zagwijn, 1960) stimulated palynological investigations into the pliocene and early quaternary, and caused a fundamental shift in our understanding of the transition from the warm and relatively stable climate of the late neogene to the extreme glacial–interglacial oscillations of the early quaternary. distinct in several aspects from the usual methodologies of that time, zagwijn’s approach can be summarized as: • focusing on establishing the botanical identification of pollen grains, following the guiding approach of his supervisor f. florschütz, using botanical nomenclature to highlight these identifications and clarify relationships between botany and the earlier artificial pollen nomenclature; • comprehensive and persistent attention to plant macroremains (fruits, seeds, etc.; zagwijn, 1990) as a mean of integrating classical palaeobotany with modern palynology; • palaeoenvironmental interpretations informed by a deep understanding of modern plant ecology and associations; • leading investigations in the field, and paying special attention to stratigraphic correlations between (onshore and offshore) boreholes and exposed sections in quarries, using a range of available proxies including heavy mineral analysis. waldo h. zagwijn was a visionary in realizing how modern palynology can be used for vegetational and climatic reconstructions in the neogene, and indeed as far back as paleogene times. keywords: pollen analysis, palaeovegetation, climatostratigraphy, pliocene–pleistocene boundary, glacials–interglacials 1. modern palynology and its contribution to global climatostratigraphy using the methodological novelties detailed above, zagwijn’s thesis identified a pronounced cooling event (marked by the establishment of tundra-like vegetation in the netherlands) separating the reuverian and tiglian continental regional stages, and he identified this as the praetiglian, a stage named earlier by van der vlerk & florschütz (1953) from the classic dutchgerman border area. zagwijn had in fact discovered the onset of pronounced glacial–interglacial cycles in the northern hemisphere. this immediately brought his work to the attention of the international scientific community. this first major contribution of zagwijn was to show how the evolution of vegetation and climate of north europe progressed cyclically from subtropical to warm-temperate and glacial conditions. it resulted in the establishment of a robust climatostratigraphy with the possibilities of long-distance correlation (van der hammen et al., 1971), based on botanical pollen classification and counting, rather than the now outdated palynostratigraphic method constructed on the presence or absence of fictitious species. aiming to obtain independent chronological control for the record of climate changes, zagwijn proposed correlations with the mediterranean succession, and this included locating the pliocene–pleistocene boundary, which had been under discussion since 1948, at the piacenzian–calabrian contact (zagwijn, 1974, 1975a). simultaneously, zagwijn explored magnetostratigraphy as a mean to calibrate climate evolution with the global timescale (zagwijn, 1975b) and paid special attention to mammal biochronology in support of regional correlations (e.g., van der meulen & zagwijn, 1974). oxygen isotope curves showed that the praetiglian glacial stage occurred in what was then considered the late pliocene (shackleton & opdyke, 1977; blanc et al., 1983; shackleton et al., 1984), as supported by subsequent pollen records in the northwestern mediterranean region (cravatte & suc, 1981; suc & cravatte, 1982; suc, 1984). as a consequence, a reliable climatostratigraphic relationship between the netherlands and the mediterranean was established and the first significant cooling in the northern hemisphere (onset of tundra-like vegetation to the north, and steppe vegetation to the south) was placed near the gauss–matuyama reversal (suc & zagwijn, 1983). the discovery confirmed the value of pollen records for long-distance correlation and strengthened the chronological framework for climate change in https://doi.org/10.26382/amq.2018.16 iv europe (zagwijn, 1986; gibbard et al., 1991; suc et al., 1995; pontini & bertini, 2000; bertini, 2001; popescu et al., 2010) (fig. 1). in addition his work provided a firm foundation for reconstructing the evolution of the north sea region throughout the late cenozoic. 2. the lowering of the pliocene– pleistocene boundary from 1.8 to 2.58 ma the age of praetiglian cooling having been established within the late pliocene (at that time, the pliocene extended to 1.8 ma), the international commission of stratigraphy (ics) approved the creation of a third stage for the pliocene, the gelasian (2.6–1.8 ma), sandwiched between the piacenzian stage (3.6–2.6 ma) and the intact calabrian stage (starting at 1.8 ma) (rio et al., 1998), aiming to avoid the prospect of lowering the pliocene–pleistocene boundary from 1.8 to 2.6 ma (suc et al., 1997). however, the quaternary community consolidated its position and, despite a disappointing setback in 1997 (for full details, see: head & gibbard, 2015), succeeded on 29 june 2009 in obtaining formal ratification from the executive committee of the iugs to lower the pliocene–pleistocene boundary to the base of the gelasian stage with an age of 2.58 ma (gibbard & head, 2010; gibbard et al., 2010) (fig. 2). waldo h. zagwijn was a strong and vocal advocate of a pliocene–pleistocene (and neogene– quaternary) boundary that coincided with the base of the praetiglian, and he readily offered arguments in support of this view, whether to opponents or supporters. zagwijn was also convinced that quaternary time was distinct and that it should not be incorporated into the neogene (fig. 2), as some of his countrymen had advocated for several decades. there can be no question that, at the age of 81, he felt this iugs decision to fig. 2 the geological time scale as it existed before the base of the pleistocene was lowered to that of the gelasian in 2009, and the current iugs/ics geological time scale. [iugs/ics geological time scale.] suc j.-p. et al. fig. 1 example of climatostratigraphic correlations at the european scale between six long pollen records from the earliest pliocene to earliest pleistocene and chronologic calibration of the northwestern european climatic succession (modified from popescu et al., 2010). pollen groups (thermic classification: nix, 1982): 1, megathermic elements (canthium, sapindaceae, bombax, etc.); 2, mega-mesothermic elements (taxodium-type, sequoia-type, arecaceae, engelhardia, distylium, microtropis fallax, etc.); 3, cathaya (= pinus haploxylon-type at wólka logezawska); 4, mesothermic elements (quercus, carya, pterocarya, liquidambar, carpinus, ulmus, zelkova, etc.); 5, pinus; 6, meso–microthermic trees (cedrus, tsuga, keteleeria); 7, microthermic trees (abies, picea); 8, elements of no significance (ranunculaceae, rosaceae, etc.); 9, cupressaceae (cupressus–juniperus-type); 10, mediterranean xerophytes (olea, pistacia, ceratonia, quercus ilex-type, rhamnus, cistus, etc.); 11, herbs (amaranthaceae, asteraceae, poaceae, apiaceae, rumex, borraginaceae, convolvulus, cyperaceae, caryophyllaceae, etc.); 12, steppe elements (artemisia, ephedra, hippophae); 13, ericaceae. v oxygen isotope records, zagwijn (1985) constructed a curve of estimated summer (july) mean temperatures in the netherlands from pollen-analytical data, and data on cryoturbatic structures (fig. 2a; for details, see: zagwijn, 1985). zagwijn’s curve was validated as representative of climatic megacycles by kukla & cílek (1996). condensing pollen data into a single curve is a crucial challenge because the progressive enrichment of pollen floras by many new taxa over time complicates interpretation. in the mediterranean region, where temperature and precipitation critically combine to characterise climate change, a pollen index is displayed by the ratio of ‘thermophilous plants/steppe elements’, which provides a curve directly comparable to oxygen isotope records (fig. 3b; suc et al., 2010). the curves illustrate the great variability of climate during each phase of a megacycle as shown for the tiglian and eburonian stages (fig. 3b). for example, the praetiglian as characterised by w.h. zagwijn with few or no minor subdivisions, has progressively been shown to abound in secondary climatic fluctuations (suc, 1984; pontini & bertini, 2000; bertini, 2001; donders et al., 2018) and may have a complex lateral expression owing to local palaeoenvironmental variation (donders et al., 2007). following the path well trodden in the netherlands, sustained effort be the ultimate recognition of his work. this was not only a vindication of his concept but an acknowledgement that climate (and of course palynology) should play a prominent role in formal stratigraphy, at least for the quaternary. 3. extending the number of glacial– interglacial cycles, and drawing palynology closer to isotope stratigraphy after defining how respectively to characterise glacials and interglacials by pollen assemblages and then delimit them (zagwijn, 1957), zagwijn (1960) proposed a climatic subdivision of the pleistocene of the netherlands that has been continuously refined to this day by the discovery of new phases (zagwijn, 1989, 1998; fig. 2a) extendable over the entire southern north basin (gibbard et al., 1991). this evolution is explained by the discontinuous character of sedimentation in the delta to flood-plain environmental contexts in which zagwijn worked. integration was achieved by piecing together sequences based on the integration of multidisciplinary lithoand biostratigraphical investigations from across the country (zagwijn & doppert, 1978; zagwijn, 1989). keen to compare his pollen data with the pioneering contributions and legacy of waldo h. zagwijn (1928-2018) fig. 3 climatic curves resulting from pollen records compared to oxygen isotope curves. a) the netherlands climatic curve matched to an oxygen isotope curve (modified from zagwijn, 1989); b) focus on the latest praetiglian to early waalian pollen ratio ‘thermophilous/steppe elements’ from the mediterranean region (crotone, calabrian stage) compared with the lr04 benthic δ18o stack (modified from suc et al., 2010, 2018). has been directed at collecting new pollen data and synthesizing with existing records in the mediterranean region to enhance our understanding of vegetational and climatic evolution (suc & popescu, 2005; leroy, 2007; bertini, 2010; popescu et al., 2010; combourieunebout et al., 2015; suc et al., 2018). finally, pollen transfer functions are now being used to reconstruct past climate from locations across europe (fauquette et al., 2007). 4. an impressive person and a brilliant career anyone who has known waldo zagwijn remembers his humility and constant attention to others. his intelligence shone through his sparkling eyes. always affable and imbued with a keen sense of detail, zagwijn was immensely interested in training young geologists and palynologists as illustrated by his commitment as a professor at the free university amsterdam. well into retirement, waldo h. zagwijn remained keenly interested in biology and geology, traits that guided his eminent career at the geological survey of the netherlands. crowned with numerous distinctions including life fellowship of inqua, royal appointment as an officer of the order of orange-nassau, and recipient of the penck medal (fig. 4), he was elected in 1980 as a member of the royal academy of sciences of the netherlands (koninklijke nederlandse akademie van wetenschappen). on the occasion of his retirement, the accademy celebrated his life’s work on october 1993 with an international symposium and a volume including his complete bibliography and many dedicated papers (herngreen & van der valk, 1995). references bertini a. (2001) pliocene climatic cycles and altitudinal forest development from 2.7 ma in the northern apennines (italy): evidence from the pollen record of the stirone section (5.1 to 2.2 ma). geobios, 34 (3), 253-265. bertini a. (2010) pliocene to pleistocene palynoflora and vegetation in italy: state of the art. quaternary international, 225, 5-24. blanc p.l., fontugne m.r., duplessy j.c. (1983) the time-transgressive initiation of boreal ice-caps: continental and oceanic evidence reconcilied. palaeogeography, palaeoclimatology, palaeoecology, 42, 211-224. combourieu-nebout n., bertini a., russo ermolli e., peyron o., klotz s., montade v., fauquette s., allen j., fusco f., goring s., huntley b., joannin s., lebreton v., magri d., martinetto e., orain r., sadori l. (2015) climate changes in the central mediterranean and italian vegetation dynamics vi fig. 4 waldo h. zagwijn (to the right) receiving the penck medal in 1973, photographed by the organizer. suc j.-p. et al. since the pliocene. review of palaeobotany and palynology, 218, 127-147. cravatte j., suc j.-p. (1981) climatic evolution of north-western mediterranean area during pliocene and early pleistocene by pollen-analysis and forams of drill autan 1. chronostratigraphic correlations. pollen et spores, 23(2), 247-258. diniz f. (1984) etude palynologique du basin pliocène de rio maior. paléobiologie continentale, 14, 259267. donders t.h., kloosterboer van hoeve m.l., westerhoff w., verreussel r.h.c.m., lotter a.f. (2007) late neogene continental stages in nw europe revisited. earth science reviews, 85, 161-186. donders t.h., van helmond n.a.g.m., verreussel r., munsterman d., ten veen j., speijer r.p., weijers j.w.h., sangiorgi f., peterse f., reichart g.j., sinninghe damsté, j.s., lourens, l., kuhlmann, g., brinkhuis, h. (2018) land–sea coupling of early pleistocene glacial cycles in the southern north sea exhibit dominant northern hemisphere forcing. climate of the past, 14, 397-411. fauquette s., suc j.-p., jiménez moreno g., micheels a., jost a., favre e., bachiri taoufiq n., bertini a., clet pellerin m., diniz f., farjanel g., feddi n., zheng, z. (2007) latitudinal climatic gradients in western european and mediterranean regions from the mid-miocene (c. 15 ma) to the midpliocene (c. 3.5 ma) as quantified from pollen data. in “deep-time perspectives on climate change. marrying the signal from computer models and biological proxies”, williams m., haywood a., gregory j., schmidt d.n. (eds.). the micropaleontological society, the geological society, london, special publications, 481-502. gibbard p.l., head m.j. (2010) the newly-ratified definition of the quaternary system/period and redefinition of the pleistocene series/epoch, and comparison of proposals advanced prior to formal ratification. episodes, 33, 152-158. gibbard p.l., head m.j., walker m.j.c., and the subcommission on quaternary stratigraphy (2010) formal ratification of the quaternary system/ period and the pleistocene series/epoch with a base at 2.58 ma. journal of quaternary science, 25(2), 96-102. gibbard p.l., west r.g., zagwijn w.h., balson p.s., burger a.w., funnell b.m., jeffery d.h., de jong j., van kolfschoten t., lister a.m., meijer t., norton p.e.p., preece r.c., rose j., stuart a.j., whiteman c.a., zalasiewicz j.a. (1991) early and early middle pleistocene correlations in the southern north basin. quaternary science reviews, 10, 23-52. head m.j., gibbard p.l. (2015) formal subdivision of the quaternary system/period: past, present, and future. quaternary international, 383, 4-35. herngreen g.f.w., van der valk l. (1995) (eds.) neogene and quaternary geology of north-west europe. contributions on the occasion of waldo h. zagwijn’s retirement. mededelingen rijks geologische dienst, 52, 510 p. kukla g., cílek v. (1996) plio–pleistocene megacycles: record of climate and tectonics. palaeogeography, palaeoclimatology, palaeoecology, 120, 171-194. leroy s.a.g. (2007) progress in palynology of the gelasian–calabrian stages in europe; ten messages. revue de micropaléontology, 50, 293-308. lisiecki l.e., raymo m.e. (2005) a pliocene– pleistocene stack of 57 globally distributed benthic δ18o records. paleoceanography, 20, pa1003. nix h. (1982) environmental determinants of biogeography and evolution in terra australis, in “evolution of the flora and fauna of arid australia”, barker w.r. & greenslade p.j.m. (eds.), peacock publishing, frewville, 47-66. pontini r., bertini a. (2000) late pliocene vegetation and climate in central italy: high-resolution pollen analyses from the fosso bianco succession (tiberino basin). geobios, 33(5), 519-526. popescu s.m. (2001) repetitive changes in early pliocene vegetation revealed by high-resolution pollen analysis: revised cyclostratigraphy of southwestern romania. review of palaeobotany and palynology, 120(3-4), 181-202. popescu s.m., biltekin d., winter h., suc j.-p., melintedobrinescu m.c., klotz s., combourieu nebout n., rabineau m., clauzon g., deaconu f. (2010) pliocene and lower pleistocene vegetation and climate changes at the european scale: long pollen records and climatostratigraphy. quaternary international, 219, 152-167. rio d., sprovieri r., castradori d., di stefano e. (1998) the gelasian stage (upper pliocene): a new unit of the global standard chronostratigraphic scale. episodes, 21, 82-87. shackleton n.j., backman j., zimmerman h., kent d.v., hall m.a., roberts d.g., schnitker d., baldauf j.g., desprairies a., homrighausen r., huddlestun p., keene j.b., kaltenback a.j., krumsiek k.a.o., morton a.c., murray j.w., westberg smith j. (1984) oxygen isotope calibration of the onset of ice-rafting and history of glaciation in the north atlantic region. nature, 307, 620-623. shackleton n.j., opdyke n.d. (1976) oxygen-isotope and paleomagnetic stratigraphy of pacific core v28-239 late pliocene to latest pleistocene. geological society of america memory, 145, 449-464. shackleton n.j., opdyke n.d. (1977) oxygen isotope and palaeomagnetic evidence for early northern hemisphere glaciation. nature, 270, 216-219. suc j.-p. (1984) origin and evolution of the mediterranean vegetation and climate in europe. nature, 307, 429-432. suc j.-p., bertini a., leroy s.a.g., suballyova d. (1997) towards the lowering of the pliocene/pleistocene boundary to the gauss–matuyama reversal. quaternary international, 40, 37-42. suc j.-p., combourieu-nebout n., seret g., popescu s. -m., klotz s., gautier f., clauzon g., westgate j., sandhu a.s. (2010) the crotone series: a synthesis and new data. quaternary international, 219, 121-133. suc j.-p., cravatte j. (1982) etude palynologique du vii the pioneering contributions and legacy of waldo h. zagwijn (1928-2018) pliocène de catalogne (nord-est de l'espagne). paléobiologie continentale, 13(1), 1-31. suc j.-p., diniz f., leroy s., poumot c., bertini a., dupont l., clet m., bessais e., zheng z., fauquette s., ferrier j. (1995) zanclean (~ brunssumian) to early piacenzian (~ early–middle reuverian) climate from 4° to 54° north latitude (west africa, west europe and west mediterranean areas). mededelingen rijks geologische dienst, 52, 4356. suc j.-p., popescu s.-m. (2005) pollen records and climatic cycles in the north mediterranean region since 2.7 ma. in “early–middle pleistocene transitions: the land-ocean evidence”, head m.j. & gibbard p.l. (eds.), geological society of london, special publication, 247, 147-158. suc j.-p., popescu s.-m., fauquette s., bessedik m., jiménez moreno g., bachiri taoufiq n., zheng z., médail f. (2018) reconstruction of mediterranean flora, vegetation and climate for the last 23 million years based on an extensive pollen dataset. ecologia mediterranea, 44, 2, in press. suc j.-p., zagwijn w.h. (1983) plio–pleistocene correlations between the northwestern mediterranean region and northwestern europe according to recent biostratigraphic and palaeoclimatic data. boreas, 12, 153-166. van der hammen t., wijmstra t.a., zagwijn w.h. (1971) the floral record of the late cenozoic of europe. in “the late cenozoic glacial ages”, turekian k.k. (ed.), yale university press, new haven and london, 391-424. van der meulen a.j., zagwijn w.h. (1974) microtus (allophaiomys) pliocaenicus from the lower pleistocene near brielle, the netherlands. scripta geologica, 21, 1-12. van der vlerk i.m., florschütz f. (1953) the palaeontological base of the subdivision of the pleistocene in the netherlands, verhandelingen koninklijke nederlandse akademie van wetenschappen, afdeling natuurkunde, 1e reeks xx, 2, 1-58. zagwijn w.h. (1957) vegetation, climate and timecorrelations in the early pleistocene of europe. geologie en mijnbouw, (n.s.), 19, 233. zagwijn w.h. (1960) aspects of the pliocene and early pleistocene vegetation in the netherlands. mededelingen van de geologische stichting, (c), 3(1), 5, 4-78. zagwijn w.h. (1974) the plio–pleistocene boundary in western and southern europe. boreas, 3, 75-97. zagwijn w.h. (1975a) a model-theory for the pliocene/ pleistocene boundary determination, based on past climatic changes. in “late neogene epoch boundaries”, saito t. & burckle l.h. (eds.), micropaleontology, special publication, 71-74. zagwijn w.h. (1975b) variations in climate as shown by pollen analysis, especially in the lower pleistocene of europe. in “ice ages: ancient and modern”, wright a.e., moseley f. (eds.), 137-152. zagwijn w.h. (1985) an outline of the quaternary stratigraphy of the netherlands. geologie en mijnbouw, 64, 17-24. zagwijn w.h. (1986) plio–pleistocene climatic change: evidence from pollen assemblages. memorie della società geologica italiana, 31, 145-152. zagwijn w.h. (1989) the netherlands during the tertiary and the quaternary: a case history of coastal lowland evolution. geologie en mijnbouw, 68, 107 -120. zagwijn w.h. (1990) subtropical relicts in the pliocene flora of brunssum (the netherlands). geologie en mijnbouw, 69, 219-225. zagwijn w.h., doppert j.w.chr. (1978) upper cenozoic of the southern north sea basin: palaeoclimatic and palaeogeographic evolution. geologie en mijnbouw, 57(4), 577-588. zagwijn w.h. (1998) borders and boundaries: a century of stratigraphical research in the tegelen reuver area of limburg (the netherlands). in “the dawn of the quaternary”, van kolfschoten th., gibbard p.l. (eds.), proceedings of the seqseuroman symposium 1996, 60. mededelingen nederlands instituut voor toegepaste geowetenschappen tno, 19-34. viii ms. received: november 1, 2018 final text received: november 27, 2018 suc j.-p. et al. sess 1_160211.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 upper pleistocene-holocene relative sea level changes at pianosa island (tuscany archipelago): geological, geomorphological and archaeological markers 1luca maria foresi, 2fabrizio antonioli, 3maurizio d’orefice, 4silvia ducci, 5marco firmati, 3roberto graciotti, 3marco pantaloni, 4paola perazzi & 6claudia principe 1dipartimento di scienze dellaterra, università di siena, siena 2enea, casaccia, roma 3ispra – servizio geologico d’italia, roma 4soprintendenza per i beni archeologici della toscana, firenze 5museo archeologico del distretto minerario di rio nell’elba, livorno 6istituto di geoscienze e georisorse, archaeomagnetic laboratory, pisa corresponding author: l. m. foresi <foresi@unisi.it> abstract: foresi l.m. et al., upper pleistocene-holocene relative sea level changes at pianosa island (tuscany archipelago): geological, geomorphological and archaeological markers. (it issn 0394-3356, 2011). based on geological, geomorphological and archaeological markers, we provides new data and interpretations on the relative sea level change occurred at pianosa island (italy) since the last 125 ka. the mis 5.5 deposits are characterized by a 2 m thick whitish fossiliferous calcarenite, cropping out at a maximum altitude of 4 m a.s.l. containing strombus bubonius. archaeological remains provide evidence of sea level change for the last 8 ka. particularly useful are some fishtanks and a quarry cut around 2 ka bp (roman age). riassunto: foresi l.m. et al., variazioni relative del livello del mare nell’isola di pianosa (arcipelago toscano) nel pleistocene superiore-olocene: markers geologici, geomorfologici e archeologici. (it issn 0394-3356, 2011). in base a dei markers geologici, geomorfologici ed archeologici, vengono forniti nuovi dati e interpretazioni sulle variazioni relative del livello del mare avvenute nell’isola di pianosa a partire dagli ultimi 125 ka. i depositi del mis 5.5 sono caratterizzati da una calcarenite fossilifera biancastra contenente strombus bubonius, affiorante fino ad un’altezza massima di 4 m s.l.m. i resti archeologici forniscono evidenze della variazione del livello del mare per gli ultimi 8 ka. particolarmente utili a tale scopo sono alcune peschiere e una cava, entrambe realizzate intorno ai 2 ka (età romana). key words: relative sea level changes, geological, geomorphological and archaeological markers, pianosa island (tuscany archipelago). parole chiave: variazioni relative del livello del mare, markers geologici, geomorfologici e archeologici, isola di pianosa (arcipelago toscano). the bedrock of the island consists of three neogene sedimentary formations (graciotti et al., 2003). the turbiditic marly-clays facies of the marina del marchese formation are burdigalian in age (bossio et al., 2000; foresi et al., 2000) and show a maximum visible thickness of about 150 m. this unit is underlain by the golfo della botte formation, about 300 m thick, made of marly clay with arenaceous and conglomeratic intercalations. the golfo della botte formation is upper tortonian – lower messinian in age, and deposited in a lacustrine lagoonal environment. the pianosa formation dated as middle pliocene – lower pleistocene consists of very fossiliferous biocalcarenites and sands with a maximum thickness of 30 m, which unconformably overlies the miocene units. in recent studies (graciotti et al., 2003; foresi et al., 2007), the authors consider this formation composed of two different units separated by a reddish-brown layer consisting of well-lithified carbonates and iron oxides and phosphates. the deposition occurred on a submarine ridge characterized by shallow water (foresi et al., 2007). the pianosa formation is covered by whitish fossiliferous calcarenite, about 2 m thick, outcropping approximately 3÷4 m a.s.l. the typical malacofauna was described by several authors (foresi et al., 2007 and reference therein) and it consents to refer this unit to the last interglacial (125 ka). these deposits are covered by red sand with clayey matrix, locally cemented, and continental breccias with red silty-sandy matrix, this units dated as upper pleistocene. pianosa has a characteristic flat sub-triangular shape, gently tilted east, due to the geological features. evidence from geomorphological analysis suggest that landscape evolution is mainly related to coastal-marine and karst processes. coastal morphology is characterized by a series of typical landforms: cliffs, wave-cut platforms, tidal 32 34 33 notches, arches, and bays. karst processes produced typical epigean (dissolution flutes, dissolution grooves, dissolution plans) and remarkable development of hypogean features. the hypogean karst of pianosa consists in caves and conduits, with a mainly horizontal development, articulated on several levels. numerous caves have the entrances to the current sea level. these are characterized by speleothemes. in the caves lithic artifacts of the final phase of the upper palaeolithic were found (la morgia & spinelli, 1994), as well as bone breccias composed of herbivorous and carnivorous animals. a clear difference exist between the western and eastern parts of the island. the former has steep cliffs and is characterized by a deep and wide inlet (golfo della botte). the latter shows less steep coasts dipping toward the east, articulated and indented due to the presence of rocky heads, small bays, and abrasion platforms. this peculiar geomorphological context is closely related to the geological setting. along the estern coast the base of the cliff is formed by the highly erodible miocene sediments, the plio-pleistocene pianosa formation which is more resistant to wave dynamics, crops out along the eastern coast. the geomorphological evolution of the island is almost driven by eustatic and tectonic movements that affected repeatedly the northern tyrrenian sea. transgressive cycles are marked by wave-cut platforms. two main orders of marine abrasion surfaces are documented at about 2÷4 m and 22÷25 m a.s.l. the wave-cut platforms of the first order (2÷4 m) outcrops anywhere along the coast, except where outcrops marly-clayey miocene sediments which favour the formation of steep cliffs because highly erodible. the wave-cut platforms of the second order, which coincide with the summit topographic surface, are fig. 1 the marzocco fishponds (pianosa island) during low tide. the arrow on the left indicates the hole communicating with sea in the southern wall. the arrow on the right box indicates the measurement of the top of separating pools wall. la peschiera del marzocco (isola di pianosa) durante la bassa marea. la freccia sulla sinistra indica il foro nel muro meridionale comunicante con il mare. la freccia sul riquadro di destra indica la misura della parte superiore del muro di upper pleistocene-holocene relative sea level ... 34 ms. received: testo ricevuto il located along the western and southern coast characterized by active cliffs. here the erosion surfaces truncates sharply clinostratified ramps of the pianosa formation. a marine ingression occurred during the last interglacial (mis 5.5 of the isotopic curve) when the mean sea level was higher than the present. this phase is represented by the basal erosion surface at an elevation of 2÷4 m a.s.l., by lithodome holes placed at various levels, up to 7 m a.s.l., and by backward paleocliffs. during uppermost pleistocene the sea level was considerably lower than the present and induced the emersion of wide areas. this condition favoured the development of karst process, particularly during the low-stand period (about 20 ky bp), when carbonatic rocks was widely exposed, and the deposition of continental breccias. in order to detail the decimetric vertical displacements for the last 2 ka, the roman age archaeological remains were studied. they were drawn in 1989 and the altitude of archaeological markers was not corrected for tide, but they have been included in this research because are indispensable to understand the shape, the functionality and where take the scuba measurements. some architectural elements (fishtanks and cetaria), were measured during the course of scuba research operation and subsequently corrected for tide and pressure. comparing the predicted sea level curve (lambeck et al. 2011) with the collected data it is possible to observe that the values lie a few centimeters below the predicted sea level curve. this result was obtained using as markers both the holes in the radial walls of the agrippa fishponds and the altitude of the uppermost walls that separate the different pools, which indicate the same altitude (fig. 1). in conclusion, based on the data obtained from analysis of the mis 5.5 age inner margin altitude and archaeological markers relating to the various types of settlements dated between 2.1 ka and 1.5 ka bp it is possible to establish that the island of pianosa has remained tectonically stable since at least 125 ka. references bossio a., cornamusini g., ferrandini j., ferrandini m., foresi l.m., mazzanti r., mazzei r. & salvatorini g. (2000) l’evoluzione sedimentaria neogenica dell’area tirrenica settentrionale (toscana marittima, isola di pianosa, bacino di aléria). in proocedings of the environment et identité en mediterranée congress. corte, france. foresi l.m., aldinucci m., sandrelli f. & cornamusini m. (2007) guida per l’escursione geosed all’isola di pianosa. in field trip guide of geosed 2007 congress, siena, italy. foresi l.m., cornamusini a., bossio a., ferrandini m., mazzei r., salvatorini g. & argenti p. (2000) the miocene sedimentary succession of the pianosa island, northern tyrrhenian sea. in proceedings of “evoluzione geologica e geodinamica dell’appennino” in memoria del prof. g. pialli. foligno, italy, 155-157. graciotti r., foresi l.m. & pantaloni m. (2003) caratteristiche geomorfologiche dell’isola di pianosa (arcipelago toscano). atti soc. tosc. sc. nat. ser. a, 108, 95-112. lambeck k, antonioli f., anzidei m., ferranti l., leoni g., scicchitano g. & silenzi s. (2011, in print) sea level change along italian coast during holocene and a proiection for the future. journal of quaternary international. la morgia j. & spinelli g.p. (1994) localizzazione e collegamento ai documenti di archivi di caverne naturali e grotte artificiali di interesse paletnologico e geologico nell’isola di pianosa – arcipelago toscano. geoarcheologia, 2, 7-38. l.m. foresi et al. january 15, 2011 15 gennaio 2011 amq63 salari kotsakis 2.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 30 (2), 2017, 125-136 late pleistocene bat assemblage with eptesicus nilssonii from grotta del fossellone (southern latium, central italy) leonardo salari 1, tassos kotsakis 2 1 c/o dipartimento scienze della terra, “sapienza” università di roma, italy 2 dipartimento di scienze, università “roma tre”, roma, italy corresponding author: l. salari <leonardosalari@virgilio.it> abstract: the study of the late pleistocene fossil assemblage of bats from the grotta del fossellone (circeo promontory, central italy) has revealed the presence of six species, rhinolophus ferrumequinum, rhinolophus euryale, myotis (myotis) blythii, myotis (leuconoë) capaccinii, eptesicus nilssonii and miniopterus schreibersii. in the late mousterian and aurignacian levels of the cave (mis 3), only m. blythii is observed, indicating open spaces around the cave. in the gravettian levels (mis 2) all the species mentioned are present, which indicates a mosaic environment with forested areas alternating with open spaces (grassland or steppe) and wetlands. particularly interesting is the presence of e. nilssonii, the only species of the assemblage currently distributed in central and northern europe. the italian peninsula, and particularly its central and southern parts, have evidently acted as a glacial refugium during the last glacial maximum for the boreal species that later, in the lateglacial and holocene, expanded its distribution to the northern regions recolonizing the lands liberated from the glacial coverage. keyword: chiroptera, circeo promontory (central italy), glacial refugia, palaeoecology, palaeobiogeography 1. introduction grotta del fossellone (san felice circeo, latium, italy) opens in the limestone of the middle lias (sgi, 1960) front in the circeo promontory, within the circeo national park. the stratigraphic successions present at fossellone and in 38 further caves form an integrated group of evidences on the prehistory in this area. today, several of these caves faces the sea, a few meters above sea level, but in the colder periods of late pleistocene the coast line was distant, due to the lowering of the sea level up to -120 m (alessio et al., 1994; benjamin et al., 2017), and the caves dominated a coastal plain (blanc & segre, 1953). many of the caves have yielded notable sedimentary deposits with pleistocene fauna, lithic industries and/or human fossils (e.g., grotta barbara, grotta breuil, grotta delle capre, grotta del fossellone, grotta guattari, riparo blanc; fig. 1) (vitagliano & bruno, 2012). archaeological and palaeontological remains from grotta del fossellone were discovered in 1936 by alberto carlo blanc (1906-1960), during his first excavation campaign in the grotta delle capre, located 200 m away (blanc, 1937). subsequently, there were two main phases of explorations in the cave. during the first phase, from 1937 to 1940, a few test excavations were carried out in a small group of minor caves that open in the internal main hall. in particular, some prehistoric layers in the main slope were identified, where several explorative trenches were opened. during the second phase, from 1947 to 1953, systematic excavations of the deposit in the central slope were carried out, where the most complete stratigraphic sequence was present, forming 51 layers through to the “tyrrhenian beach”, with a thickness of about 14 m (blanc & segre, 1953; alhaique et al., 1996). in 1953-54 some human bone fragments, including a mandible of a baby, ascribed to homo neanderthalensis were discovered (mallegni, 1992). in 1989, systematic studies of the archaeological and palaeontological collections started (vitagliano & piperno, 1991; alhaique et al., 1996, 1998; alhaique & tagliacozzo, 2000). the bat fossils were given to us for the study by the late professor amilcare bietti (1937-2006), who was part of the archaeological team who made the last excavations in the cave. a preliminary list of the bat species was presented at the aiqua meeting in memory of alberto malatesta (1915-2007) in rome, 4-5 february 2010 (salari & kotsakis, 2011). in this paper the bat fossils collected in the grotta del fossellone are described and discussed. 2. stratigraphic notes grotta del fossellone (fig. 1) conserves pleistocene marine sediments (“tyrrhenian beach”) at the bottom of the sequence (blanc & segre, 1953; vitagliano & piperno, 1991; alhaique et al., 1996). the overlying continental sequence is composed of 51 layers in the central slope. the 10 layers at the bottom did not contain lithic industry. the other layers can be grouped into three units (blanc & segre, 1953; alhaique et al., 1996; vitagliano & bruno, 2012): 126 salari l., kotsakis t. fig. 1 grotta del fossellone (latium, italy): location of the site. 127 late pleistocene bat assemblage with eptesicus nilssonii from grotta del ..... levels 41-23 with lithic industries referred to the middle palaeolithic (mousterian); levels 21-17, separated from the mousterian levels by a layer of sterile red clay (level 22), with aurignacian industry; levels 16-1 with bone and lithic artefacts referred to gravettian. in the levels 27-23 a peculiar industry referred to the late and final mousterian was found (vitagliano & bruno, 2012). in these layers, the large mammal remains are scarce; the most frequent species is bos primigenius followed by cervus elaphus and less frequent wild horse, whereas wild boar, ibex and equus hydruntinus are rarer (alhaique et al., 1998; alhaique & tagliacozzo, 2000). the mammal assemblage in level 21, is considerably more abundant and it is dominated by e. hydruntinus followed by c. elaphus, whereas b. primigenius, wild horse, ibex, wild boar and roe deer are less frequent (alhaique et al., 1998; alhaique & tagliacozzo, 2000). bird bones, which are rare in levels 2723, are abundant in level 21, aurignacian, and mainly consist of perdix perdix, columba livia and pyrrhocorax graculus; from a climatic and environmental point of view, the occurrence of nyctea scandiaca and anser albifrons, cold and boreal birds, is particularly interesting (alhaique et al., 1998; alhaique & tagliacozzo, 2000). such as for bone and lithic artefacts, also the vertebrate remains are very scarce in levels 16-1, gravettian (alhaique et al., 1996; vitagliano & bruno, 2012). 3. materials and methods the material analysed is housed in the department of geological sciences of the “roma tre” university and it is numbered from lpvrt 00411 to lpvrt 00431. a few fossil remains come from level 23, mousterian, and level 21, aurignacian, and 46 specimens from levels 12, 9, 5, 4 and 1, gravettian (tab. 1). the bat remains were compared with osteological material, both fossil and recent, stored in the department of earth sciences of the university of rome “sapienza” and in the department of geological sciences of the “roma tre” university. moreover, we use morphological and morphometric data and dichotomous keys given by felten et al. (1973), sevilla garcía (1988), niethammer & krapp (2001), salari (2004) and lanza (2012). the analyses were performed with a stereoscopic microscope nikon smz-u in the department of sciences of the “roma tre” university; the pictures and the measurements were taken with a leika dfc290 system using the leica application suite software. for taxonomic determinations the analyzed material was chosen on the basis of its systematic importance (cranium, mandible and humerus). the minimum number of individuals (mni) was calculated using the most represented side (right or left) of maxillae, mandibles and humeri; this result was integrated with the analysis of the age and the dimensional characters of the other skeletal elements. in this work we follow simmons (2005), with the following exceptions. miniopteridae are considered as family, distinct from vespertilionidae, in agreement with mein & tupinier (1977), agnelli et al. (2006), millerbutterworth et al. (2007) and lanza (2012). we use the taxon myotis blythii instead of myotis oxygnathus, according to agnelli et al. (2006), furman et al. (2014) and juste & paunovi� (2016). this is also in agreement with most palaeontological works identifying remains of european largesized myotis, distinct from m. myotis, as m. blythii (not as m. oxygnathus or m. blythii oxygnathus). environmental reconstructions are based on studies on the ecology and biogeographical distribution of modern taxa (horá�ek et al., 2000; niethammer & krapp, 2001; agnelli et al., 2006; lanza, 2012). quaternary chronostratigraphy and geochronology according to gibbard et al. (2010). for italian continental biochronology we follow kotsakis et al. (2003). 4. taxonomy order chiroptera blumenbach, 1779 family rhinolophidae gray, 1825 genus rhinolophus lacépède, 1799 rhinolophus ferrumequinum (schreber, 1774) a mandible (lpvrt 00412), three humeri and two distal portions of humerus (lpvrt 00411, 00413-14) (figs. 2a-b; tab. 1) have the typical morphology of the genus rhinolophus. in the mandible, p4 is subquadrangular with pyramidal cusp; the molars are of nyctalodontic type, m1 and m2 have trigonid slightly longer than the talonid and the cingulum, very thin, more evident on the trigonid; m3 is relatively small and the cingulum is thin, especially on the talonid. in the distal epiphysis of humerus, epicondyle, trochlea, inner ridge tab. 1 grotta del fossellone, late pleistocene: number of identified specimens (nisp) and minimum number of individuals (mni) of species identified. l.: level. and lateral ridge are separated by grooves, less deep that dividing inner and lateral ridges; the styloid process is relatively long and thin, slightly dorsally inclined in lateral view (felten et al., 1973). these morphological features and the large size (tab. 2), enables a definite attribution to the big horseshoe bat. r. ferrumequinum is a species of mediterranean affinities and today’s range of distribution includes central europe, extending from southern england, and the mediterranean basin through asia to japan; in italy this species occurs in all regions (horá�ek et al., 2000; gaisler, 2001a; agnelli et al., 2006; lanza, 2012). the earliest fossil records of r. ferrumequinum come from some italian and spanish localities referred to the late early pleistocene (middle early biharian, late villafranchian; salari et al., 2013; galan et al., 2016a). indeed, many specimens of pliocene or early early pleistocene, assigned in the past to r. ferrumequinum 128 fig. 2 grotta del fossellone, late pleistocene: rhinolopus ferrumequinum: a) right mandible (lpvrt 00413), labial view, b) distal epiphysis of right humerus (lpvrt 00412); rhinolophus euryale: c) portion of cranium (lpvrt 00418), occlusal view, d) distal epiphysis of left humerus (lpvrt 00419); e) myotis blythii, distal epiphysis of left humerus (lpvrt 00421); f) myotis capaccinii, distal epiphysis of right humerus (lpvrt 00427); g) eptesicus nilssonii, distal epiphysis of left humerus (lpvrt 00428) (1 external, 2 internal, 3 dorsal views); h) miniopterus schreibersii, distal epiphysis of right humerus (lpvrt 00430). salari l., kotsakis t. or r. cf. ferrumequinum have been ascribed to other species of the group (topal, 1979; wo�oszyn, 1987). some pliocene or early early pleistocene remains recently assigned to the same taxa are reported in preliminary lists and their attribution must be confirmed. fossil remains of this species have been collected in several sites of middle pleistocene in central and southern europe and in north africa, and in many sites of late pleistocene from portugal and england to japan and south to maghreb and near east (capasso barbato & kotsakis, 1986; kotsakis, 1987, 1991; esu et al., 1990; lindenau, 2005; tata & kotsakis, 2005; argenti et al., 2008; tang & kotsakis, 2008; salari, 2009, 2010; salari & di canzio, 2009; salari et al., 2013, and references therein; horá�ek et al., 2013; galan et al., 2016b; sevilla, 2016; spena et al., 2017). rhinolophus euryale blasius, 1853 two incomplete crania (lpvrt 00418), five humeri and several distal portions of humerus (lpvrt 00415-17, 00419-20) (figs. 2c-d; tab. 1) belonging to the middle-sized species of genus rhinolophus. the preorbital bridge is strong (lanza, 2012), first and second upper molars have a distal concave edge and the labial cingulum is very prominent (sevilla garcía 1988), and the styloid process of distal humerus is long and thin, slightly dorsally inclined in lateral view (felten et al., 1973). these morphological features and the measurements (tab. 2) enables a sure attribution to mediterranean horseshoe bat. r. euryale is a species of strict mediterranean affinities, typically troglophilous; today’s range of distribution includes southern europe, south-western asia and north-western africa; in italy this species occurs throughout the territory with the probable exception of some northern regions (horá�ek et al., 2000; gaisler, 2001b; agnelli et al., 2006; lanza, 2012). bat fossils referred to rhinolophus ex gr. r. euryale are known in eastern europe since the early pliocene (late ruscinian), and in italy from late early pleistocene (middle early biharian, late villafranchian; salari et al., 2013). fossil remains of the mediterranean horseshoe bat come from several middle and late pleistocene localities of the mediterranean basin, poland and near east (kotsakis & petronio, 1980; kotsakis, 1991; lindenau, 2005; tata & kotsakis, 2005; salari & di canzio, 2009; salari, 2010; salari et al., 2013, and references therein; horá�ek et al., 2013; sevilla, 2016; 129 tab. 2 grotta del fossellone, late pleistocene: osteometric measurements (mm) and comparison with other sites. abbreviations: l. = maximum length; c-m3 = length of upper tooth-row between c and m3 (incl.); m1-m3 = length of upper molars; m3-m3 = rostral width between third upper molars (incl.); c-m3 = length of lower tooth-row between c and m3 (incl.); m1-m3 = length of lower molars; bd = distal breadth; n. = number of measurements; min = minimum; max = maximum; mea = mean; s.d. = standard deviation. *: m. myotis and m. blythii. grotta breuil unpublished data; caverna delle arene candide by salari (2010); mandible of extant r. ferrumequinum by gaisler (2001a); cranium of extant r. euryale by popov & ivanova (2002); distal breadth of humerus of all extant species by felten et al. (1973). late pleistocene bat assemblage with eptesicus nilssonii from grotta del ..... spena et al., 2017). family vespertilionidae gray, 1821 genus myotis kaup, 1829 subgenus myotis kaup, 1829 myotis (myotis) blythii (tomes, 1857) several distal portions of humerus (lpvrt 0042126) (fig. 2e; tab. 1) belonging to the great-sized species of genus myotis: the epicondyle is reduced, with trochlea, inner and outer ridges separated by grooves; the styloid process is strongly reduced but still present. with respect to the distinction between the largebodied myotis (excluding m. punicus for palaeobiogeographic reasons), the only certain morphological difference between the teeth of m. myotis and m. blythii occurs on the talonid of third lower molar, which is more reduced in m. myotis (see topál & tusnadi, 1963; sevilla garcía, 1988). concerning the humeri of identical morphology (felten et al., 1973), discrimination between the two species mainly relied on the distal epiphysis, ascribing only the larger ones and those of more robust aspect to m. myotis, with all remaining material being assigned to m. blythii. in our sample there are no particularly robust specimens and also the measurements (tab. 2) support the attribution to m. blythii. the lesser mouse-eared bat is a species of mediterranean affinities, thermophilous, the recent range of the species includes southern europe, the southern part of the central europe, east to china and mongolia; in italy it occurs in all regions with the possible exception of sardinia (horá�ek et al., 2000; topál & ruedi, 2001; agnelli et al., 2006; lanza, 2012). the earliest records of fossils referred to myotis cf. m. blythii come from some eastern europe sites referred to late pliocene (late ruscinian), and in italy from early early pleistocene (late villanyan, middle villafranchian; salari et al., 2013). fossil remains of this specie occur in several middle pleistocene localities and in many late pleistocene sites of southern and eastern europe and near east (capasso barbato & kotsakis, 1986; lindenau, 2005; tata & kotsakis, 2005; tang & kotsakis, 2008; salari, 2009, 2010; salari & di canzio, 2009; salari et al., 2013, and references therein; horá�ek et al., 2013; sevilla, 2016; spena et al., 2017). subgenus leuconoë boie,1830 myotis (leuconoë) capaccinii (bonaparte, 1837) a distal portion of a right humerus (lpvrt 00427) from level 1 (fig. 2f; tab. 1) is very similar in morphology (felten et al., 1973) and dimensions (tab. 2) to the humerus of living m. capaccinii: epicondyle with reduced trochlea, inner and outer ridges separated by grooves, and the styloid process is moderately developed. the long-fingered bat is a species of strict mediterranean affinities, typically troglophilous; the current range includes the mediterranean basin, southern europe, north-western africa, south-western asia to iran and uzbekistan; in italy this species occurs in all regions (horá�ek et al., 2000; spitzenberger & helversen, 2001; agnelli et al., 2006; lanza, 2012). the oldest fossils of the long-fingered bat are known in some mediterranean localities, including italy, since the late early pleistocene (middle early biharian, late villafranchian; salari et al. 2013). it is found in some middle and late pleistocene sites from central and southern italy and other circum-mediterranean localities, invariably represented by few remains, whereas in northern italy and in the remaining western palaearctic it is rarely reported (kotsakis & petronio, 1980; kotsakis, 1987; lindenau, 2005; tata & kotsakis, 2005; tang & kotsakis, 2008; salari, 2009; 2010; salari & di canzio, 2009; salari et al., 2013, and references therein; spena et al., 2017). genus eptesicus rafinesque, 1820 eptesicus nilssonii (keyserling and blasius, 1839) a distal portion of a left humerus (lpvrt 00428) from level 1 (figs. 2g1, 2g2, 2g3; tab. 1) is very similar in morphology (felten et al., 1973) and dimensions (tab. 2) to the humerus of living e. nilssonii: the epicondyle is reduced, inner and outer ridges separated by grooves, and the passage from the trochlea to the condyle is almost straight; the styloid process (a little broken) is moderately developed and the articular fossette is clear and wide. the northern bat is a species of boreal affinities and the only one, among all the bats in the world, which reproduces even beyond the arctic circle (as far as 70° 25’ n) (rydell et al., 1994; agnelli et al., 2006). its current range of distribution includes central and northern europe, extending from the northern balkans through the palearctic asia to sakhalin, korea and japan (gerel & rydell. 2001; agnelli et al.. 2006; lanza. 2012). currently, its southernmost limit of distribution in europe is the south-eastern alpine arch and the northern balkans, with isolated colonies in the rila mountains in bulgaria (hanák & horà�ek, 1986; gerel & rydell, 2001; lanza, 2012). the scarce records available for italy show that its presence is limited to some mountain resorts of the alpine arch (agnelli et al., 2006; lanza, 2012; patriarca & debernardi, 2014). e. nilssonii fossils are known since the early middle pleistocene in poland (wo�oszyn, 1987). during the late pleistocene and early holocene, this species settled in various sites of former soviet union, such as crimea, altai, siberia and far east (rydell, 1993; rossina, 2006; rosina, 2012; tiunov, 2016), central europe (horá�ek, 1995; popov, 2000; piksa & wo�oszyn, 2001; ochman, 2003; ochman & wo�oszyn, 2003; noël et al., 2008; pazonyi et al., 2014), and only at grotta del broion (veneto) in italy (pasa, 1953). family miniopteridae dobson, 1875 genus minioperus bonaparte, 1837 miniopterus schreibersii (kuhl, 1819) a humerus and two distal portions of humerus (lpvrt 00429-31) (fig. 2h; tab. 1) belong to the genus miniopterus: the medial epicondyle is relatively narrow, the trochlea is separated from the inner ridge by a not deep groove, while inner and lateral ridges are separated one from each other by a deep groove; the styloid process is long and narrow and is parallel to the axis of the humerus. these morphological features (felten et al., 1973) and the measurements (tab. 2) enables a definite attribution to m. schreibersii. schreiber’s bat is a species sub-cosmopolitan, but of strict mediterranean affinities, typically troglophilous; 130 salari l., kotsakis t. the current range comprises all populations living from southern europe and morocco to sub-saharan africa, madagascar and through southern asia to oceania; in italy this species occurs throughout to the whole country (horá�ek et al., 2000; agnelli et al., 2006; lanza, 2012). m. schreibersii is known since the early early pleistocene (late villanyan, middle villafranchian) in various localities of central europe, and in italy from late early pleistocene (middle early biharian, late villafranchian; salari et al., 2013). schreiber’s bat disappeared from central europe during the glacial phases of middle and late pleistocene but was present in the mediterranean basin and expanded its area of distribution further north during the interglacial phases (kotsakis & petronio, 1980; kotsakis, 1987, 1991; lindenau, 2005; tata & kotsakis, 2005; tang & kotsakis, 2008; salari, 2009, 2010; salari & di canzio, 2009; salari et al., 2013, and references therein; horá�ek et al., 2013; galan et al., 2016b; sevilla, 2016; spena et al., 2017). 5. discussion all the six species identified at grotta del fossellone (tab. 1) are still part of the extant italian bat fauna (agnelli et al., 2006; lanza, 2012). among these, rhinolophus ferrumequinum, rhinolophus euryale, myotis blythii, myotis capaccinii and miniopterus schreibersii today occur in latium (crucitti, 2011; capizzi et al., 2012) and also within the circeo national park territory, except probably for m. blythii (see mastrobuoni & zerunian, 2003; mastrobuoni, 2009a, 2009b), whereas eptesicus nilssonii occurs only in a few localities of alpine arch (agnelli et al., 2006; lanza, 2012; patriarca & debernardi, 2014). except for e. nilssonii, all the fossils belong to troglophilous species (tab. 3), and ascertained traces of digestion on the bone surfaces were not found (except for two remains of r. euryale and r. ferrumequinum). therefore, it is very likely that the bat remains consisted mainly of the natural accumulation of animals that lived and died in the cave (sevilla garcía, 1988; kowalski, 1995; salari & silvestri, 2015). bats have a foraging range of several kilometres from their roosts (niethammer & krapp, 2001; agnelli et al., 2006; lanza, 2012). therefore, by analysing the present distribution areas and foraging environments of the species identified (tab. 3), the study of the fossil assemblage provides interesting information on the surroundings of the cave at the time of their deposition. for refined quantitative analyses, significantly numerous samples are required, taking into account that some species form large colonies (monospecific or mixed), even of thousands of individuals, others form smaller colonies, from a few individuals to several hundred or have more solitary behaviours (tab. 3). however, despite the limited numerical significance of our sample, it can still provide useful environmental information. in the levels 23, mousterian, and 21, aurignacian, only few remains of m. blythii were found, and one can only admit that probably in the surrounding of cave were also open spaces, as confirmed by the occurrence of equids (alhaique et al., 1998; alhaique & tagliacozzo, 2000). instead, in the mousterian layers of the grotta breuil, also in the circeo promontory, a rich fossil bat assemblage was found (kotsakis, 1991; salari & di canzio, 2009; salari & kotsakis, 2011). the ecological features of the species found in this cave are compatibles with the environmental reconstruction outlined by alhaique et al. (1998) and alhaique & tagliacozzo (2000) for the surroundings of grotta del fossellone. also in the mousterian of nearby grotta barbara were found several bat fossils and even the ecological features of the species found in this cave suggest a variety tab. 3 synthetic notes on foraging environment and roosting habits in italy and zoogeographical pattern for the species considered. data from horá�ek et al. (2000), agnelli et al. (2006), salari & di canzio (2009), lanza (2012); m a.s.l.: meters above sea level; s.l.: sensu lato; s.s.: sensu stricto. 131 late pleistocene bat assemblage with eptesicus nilssonii from grotta del ..... of environments in the circeo promontory during this phase of late pleistocene (salari & kotsakis, 2011). the six species found in the gravettian layers of grotta del fossellone foraging in various environments (tab. 3), and its ecological features allow us to outline a composite landscape with extensive woodlands interspersed with open spaces (steppe, grasslands and scrubland), rocky areas and marginal wetland. levels 12-5 yielded few remains and the species more frequent is m. blythii, while level 1 makes more numerous bat fossils, m. blythii disappear and the species dominant is r. euryale (tab. 1). despite the limited amount of fossils that precludes any definitive conclusion, it can be assumed that the environment surrounding the cave has evolved from more open towards greater forest cover. the occurrence of e. nilssonii, a non troglophilous species, cold and boreal bat, far to the south of the limit of its current distribution, suggests a colder climate than the present. according to alhaique et al. (1998) and alhaique & tagliacozzo (2000), the bird and mammal assemblages from level 21 indicate a climate colder than that documented in the mousterian layers. the bat assemblage seems to suggest that during the gravettian the climate further evolved towards the cold. the levels 27-23, mousterian, can be referred to temperate oscillations of marine isotope stage (mis) 3, the aurignacian layers to the final mis 3 or the beginning of mis 2 (salari & kotsakis, 2011), and the gravettian layers can be referred to mis 2, around to the last glacial maximum (lgm). indeed, according to some authors (e.g., mussi, 2002; antonioli & vai, 2004; sala, 2005) the gravettian industry is well documented in italy during this coldest period of the late pleistocene. in the lgm, iberian and italian peninsulas and the balkans played the role of main glacial refugia for many temperate or warm animal and plant species, which repopulated the rest of europe during the lateglacial and holocene (bilton et al., 1998; stewart & lister, 2001; sommer & nadachowski, 2006; gavin et al., 2014). as for european bats, fahlke (2009) reported that these have deserted the area north to the alps in the lgm, and that it was only in the first stages of the lateglacial, during the bølling-allerød temperate oscillations, that some species (eptesicus serotinus followed by plecotus auritus and barbastella barbastellus) returned to the area. in effect, few other bats, including e. nilssonii, nyctalus noctula and a few species of the genera myotis and pipistrellus are reported in the lateglacial sequences of central-northern europe (horá�ek, 1995; ochman, 2003; horá�ek & jahelková, 2005). moreover, according to fladerer (2000), in the southeastern side of the alps in the lgm the only presence of p. auritus is documented, then during the lateglacial the area would be populated by vespertilio murinus, followed by e. serotinus, m. myotis, myotis bechsteinii, myotis nattereri and b. barbastellus. in the cold periods of late pleistocene, centralsouthern italy and liguria hosted many species which are now largely distributed in central and northern europe (e.g., rhinolophus hipposideros, myotis dasycneme, m. myotis, m. bechsteinii, myotis mystacinus, p. auritus, n. noctula and b. barbastellus) (argenti et al., 2008; salari, 2010; salari & kotsakis, 2011; bogdanowicz et al., 2015), and that have returned to these lands, but even in some regions south of the alps (e.g., canton ticino, switzerland), only in the holocene (horá�ek, 1995, 2007; horá�ek & jahelková, 2005; blant et al., 2008; ruedi et al., 2008; fahlke, 2009; hutterer et al., 2012). thus, the occurrence of e. nilssonii in the lgm at grotta del fossellone show that circeo promontory played a role of glacial refugium in the late pleistocene for this boreal species currently distributed in central and northern europe. 6. conclusion six species of bats divided into three families (rhinolophidae, vespertilionidae and miniopteridae) and four genera (rhinolophus, myotis, eptesicus and miniopterus) have been discovered in the fossil assemblage from grotta del fossellone. all the species identified are still part of the extant italian bat fauna and today also occur in latium, except for eptesicus nilssonii that is now distributed in central-northern europe. the fossil bat assemblage examined is probably an autochthonous thanatocoenosis. the bat remains do not show major morphological or morphometric differences from other late pleistocene and extant populations of the same species. the ecological needs of the species of bats present at grotta del fosselone allow to outline for the gravettian period a composite environment with wooded areas interrupted by open spaces (grassland or steppe), rocky areas and wetlands. the occurrence in the latest gravettian layer of e. nilssonii, far to the south of the limit of its current distribution, suggests a colder climate than the mousterian and aurignacian layers and the present. probably the gravettian layers were deposed in the lgm. grotta del fossellone represents the southernmost limit of e. nilssonii in europe, even considering its distribution in the pleistocene. the occurrence of this species in the lgm at grotta del fossellone, as well as of m. dasycneme in the lateglacial of grotta di cittareale (argenti et al., 2008; salari & kotsakis, 2011), show that during the coldest stages of the late pleistocene the coastal regions and the apennine of latium must have played an important role of glacial refugia for these boreal species which are now distributed in centralnorthern europe. acknowledgements we want to thank maria rita palombo and lutz maul for their useful comments to our manuscript. references alessio m., allegri l., antonioli f., belluomini g., improta s., manfra l., preite martinez m. (1994) la curva di risalita del mare tirreno negli ultimi 43 ka ricavata da datazioni su speleotemi sommersi e dati archeologici. memorie descrittive della carta geologica d’italia, 52, 261-276. agnelli p., martinoli a., patriarca e., russo d., scaravelli d., genovesi p. (2006) guidelines for 132 salari l., kotsakis t. tères du pléistocène supérieur de la grotte de monte cucco (italie centrale). geologica romana, 25, 309-316. capizzi d., mortelliti a., amori g., colangelo p., rondinini, c. (2012) i mammiferi del lazio. distribuzione, ecologia e conservazione. edizioni arp, roma, pp. 266. crucitti p. (2011) bats of latium: a review of past and recent studies and the contribution of b. lanza. hystrix, italian journal of mammalogy, 22, 15-22. esu d., galdenzi s., kotsakis t. (1990) molluschi e microvertebrati nel deposito pleistocenico della grotta del vento (gola della rossa ancona). nota preliminare. memorie della società italiana di speleologia, ser. ii, 4, 193-198. fahlke j.m. (2009) der austausch der terrestrischen säugetierfauna an der pleistozän/holozän-grenze in mitteleuropa. phd thesis, universität rheinischen friedrich-wilhelms, bonn, pp. 279. felten h., helfricht a., storch g. (1973) die bestimmung der europäischen fledermäuse nach der distalen epiphyse des humerus. senckenbergiana biologica, 54, 291-297. fladerer f.a. (2000) late quaternary vertebrate taphocoenoses from cave deposits in southeastern austria: responses in a periglacial setting. in: m.b. hart (ed.), climates: past and present. geological society of london, special publications, 181, 199213. furman a., çoraman e., çelik y.e., postawa t., bachanek j., ruedi m. (2014) cytonuclear discordance and the species status of myotis myotis and myotis blythii (chiroptera). zoologica scripta, 43, 549-561. gaisler j. (2001a) rhinolophus ferrumequinum (schreber, 1774) große hufeisenasse. in: niethammer j., krapp f. (eds), handbuch der säugetiere europas. bd. 4: fledertiere, teil i: chiroptera i. aula-verlag, wiebelsheim, 15-37. gaisler j. (2001b) rhinolophus euryale blasius, 1853 mittelmeerhufeisenasse. in: niethammer j., krapp f. (eds), handbuch der säugetiere europas. bd. 4: fledertiere, teil i: chiroptera i. aula-verlag, wiebelsheim, 59-74. galan j., cuenca-bescós g., lópez-garcía j.m. (2016a) the fossil bat assemblage of sima del elefante lower red unit (atapuerca, spain): first results and contribution to the palaeoenvironmental approach to the site. comptes rendus palevol, 15, 647-657. galan j., cuenca-bescós g., lópez-garcía j.m., sauqué v., núñez-lahuerta c. (2016b) fossil bats from the late pleistocene site of the aguilón p7 cave (zaragoza, spain). comptes rendus palevol, 15, 501-514. gavin d.g, fitzpatrick m.c., gugger p.f., heath k.d., rodríguez-sánchez f., dobrowski s.z., hampe a., hu f.s., ashcroft m.b., bartlein p.j., blois j.l., carstens b.c., davis e.b., lafontaine g. de, edwards m.e., fernandez m., henne p.d., herring e.m., holden z.a., kong w.s., liu j., magri d., matzke n.j., mcglone m.s., saltré f., stigall a.l., tsai y.h.e., williams j.w. (2014) climate bat monitoring: methods for the study and conservation of bats in italy. quaderni di conservazione della natura, 19 bis, 1-200. alhaique f., bietti a., biondi s., cassoli p.f., tagiacozzo a., vitagliano s. (1996) grotta del fossellone (san felice circeo, latina). in: bietti a., grifoni cremonesi r. (eds), guide archeologiche, preistoria e protostoria in italia 10, lazio e abruzzo, u.i.s.p.p., abaco, forlì, 114-121. alhaique f., biondi s., cassoli p.f., recchi a., tagliacozzo a. (1998) modifications in the exploitation of animal resources between the middle palaeolithic and the aurignacian at grotta del fossellone (monte circeo, italy). atti del xiii congresso u.i.s.p.p. 2, abaco, forlì, 571-576. alhaique f., tagliacozzo a. (2000) l’interpretazione dei dati faunistici nella ricostruzione delle strategie di sussistenza nel paleolitico medio: l’esempio del lazio. atti del 2° convegno nazionale di archeozoologia, abaco, forlì, 111-124. antonioli f., vai g.b. (2004) lithopalaeoenvironmental maps of italy during the last two climatic extremes. explanatory notes. museo geologico cappellini, bologna, pp. 80. argenti p., kotsakis t., sabatini f. (2008) myotis dasycneme in a latest pleistocene bat assemblage of cittareale cave (rieti, latium, central italy). geologica romana, 41, 117-123. benjamin j., rovere a., fontana a., furlani s., vacchi m., inglis r.h., galili e., antonioli f., sivan d., miko s., mourtzas n., felja j., meredith-williams m., goodman-tchernov b., kolaiti e., anzidei m., gehrels r. (2017) late quaternary sea-level changes and early human societies in the central and eastern mediterranean basin: an interdisciplinary review. quaternary international, 449, 29-57. bilton d.t., mirol p.m., mascheretti s., fredga k., zima j., searle j.b. (1998) mediterranean europe as an area of endemism for small mammals rather than a source for northwards postglacial colonization. proceedings royal society of london, biological sciences, 265, 1219-1226. blanc a.c. (1937) fauna a ippopotamo ed industrie paleolitiche nel riempimento delle grotte litoranee del monte circeo. i. la grotta delle capre. ii. la grotta del fossellone. rendiconti della reale accademia nazionale dei lincei, classe di scienze fisiche matematiche e naturali, serie 6, 25, 88-93. blanc a.c., segre a.g. (1953) excursion au mont circé: le volcan latial, le mont circé. livret-guide du iv congrès international inqua, roma-pisa, pp. 108. blant m., moretti m., tinner w. (2008) fréquence de quelques chiroptères durant l’holocène. geographica helvetica, 63, 188-192. bogdanowicz w., hulva p., �erná bolfíková b., bu� m.m., rychlicka e., sztencel-jab�onka a., cistrone a., russo d. (2015) cryptic diversity of italian bats and the role of the apennine refugium in the phylogeography of the western palaearctic. zoological journal of the linnean society, 174, 635648. capasso barbato l., kotsakis t. (1986) les chirop 133 late pleistocene bat assemblage with eptesicus nilssonii from grotta del ..... refugia: joint inference from fossil records, species distribution models and phylogeography. new phytologist, 204, 37-54. gerel r.j., rydell j. (2001) eptesicus nilssonii (keyserling et blasius, 1839) nordfledermaus. in: niethammer j., krapp f. (eds), handbuch der säugetiere europas. bd. 4: fledertiere, teil i: chiroptera i. aula-verlag, wiebelsheim, 561-581. gibbard p.l., head m.j., walker m.j.c. and the subcommission on quaternary stratigraphy (2010) formal ratification of the quaternary system/ period and the pleistocene series/epoch with a base at 2.58 ma. journal of quaternary science, 25, 96-102. hanák v., horà�ek i. (1986) zur südgrenze des areals von eptesicus nilssoni (chiroptera: vespertilionidae). annalen des naturhistorischen museums in wien, b, 88/89, 377-388. horá�ek i. (1995) k formování st�edoevropské netopý�í fauny. netopiere (bratislava), 1, 93-98. horá�ek i. (2007) holocene history of the mammalian fauna in the northern bohemian sandstone region (czech republic). in: härtel h., cílek v., jackson a., williams r. (eds), sandstone landscapes, academia, praha, 265-272. horá�ek i., hanák v., gaisler j. (2000) bats of the palearctic region: a taxonomic and biogeographic review. in: wo�oszyn b.w. (ed.), proceedings of the viiith ebrs, 1, 11-157. horá�ek i., jahelková h. (2005) history of the pipistrellus pipistrellus group in central europe in light of its fossil record. acta chiropterologica, 7, 189-204. horá�ek i., maul l.c., smith k.t., barkai, r., gopher a. (2013) bat remains (mammalia, chiroptera) from the middle pleistocene site of qesem cave, israel, with the first pleistocene record of fruit bats in the mediterranean region. palaeontologia electronica 16, 23a, pp. 19. palaeo-electronica.org/content/2013/513-qesembats. hutterer r., montermann c., weigt m. (2012) a holocene bat fauna from the eifel mountains, germany. vespertilio, 16, 159-164. juste j., paunovi� m. (2016) myotis blythii. the iucn red list of threatened species 2016: e.t14124a22053297. doi: 10.2305/iucn.uk.2016-2.rlts.t14124a22 053297.en. downloaded on 04 november 2017. kotsakis t. (1987) les chiroptères du pléistocène supérieur des environs de alghero (sardaigne, italie). geologica romana, 26, 103-108. kotsakis t. (1991) late pleistocene fossil microvertebrates of grotta breuil (monte circeo, central italy). quaternaria nova, 1, 325-332. kotsakis t., petronio c. (1980) i chirotteri del pleistocene superiore della grotta di spinagallo (siracusa, sicilia). bollettino del servizio geologico d’italia, 101, 49-76. kotsakis t., abbazzi l., angelone c., argenti p., barisone g., fanfani f., marcolini f., masini f. (2003) plio-pleistocene biogeography of italian mainland micromammals. deinsea, 10, 313-342. kowalski k. (1995) taphonomy of bats (chiroptera). geobios, m.s., 18, 251-256. lanza b. (2012) fauna d’italia. mammalia v. chiroptera. edizioni calderini de il sole 24 ore, milanobologna, pp. 800. lindenau c. (2005) middle pleistocene bats (mammalia: chiroptera) from the yarimburgaz cave in turkish thrace (turkey). eiszeitalter und gegenwart, 55, 122-148. mallegni f. (1992) human remains (fossellone 3; ex circeo 4) referable to homo s. neandertalensis from fossellone cave (monte circeo, latium, italy). rivista di antropologia, 70, 217-227. mastrobuoni g. (2009a) edifici storici e chirotteri: il caso del borgo di villa fogliano (provincia di latina). in: dondini g., fusco g., martinoli a., mucedda m., russo d., scotti m., vergari s. (eds), chirotteri italiani: stato delle conoscenze e problemi di conservazione. atti del 2° convegno italiano sui chirotteri, 58-61. mastrobuoni g. (2009b) i chirotteri dell’area archeologica villa di domiziano (sabaudia, latina): fenologia, uso dei rifugi e interventi per la conservazione. in: dondini g., fusco g., martinoli a., mucedda m., russo d., scotti m., vergari s. (eds), chirotteri italiani: stato delle conoscenze e problemi di conservazione. atti del 2° convegno italiano sui chirotteri, 111-114. mastrobuoni g., zerunian s. (2003) primi dati sulla chirotterofauna del parco nazionale del circeo (lazio). in: prigioni c., meriggi a., merli e. (eds), atti del iv congresso italiano di teriologia, hystrix, italian journal of mammalogy, supp. 2003, 155156 mein p., tupinier y. (1977) formule dentaire et position systématique du minioptère (mammalia, chiroptera). mammalia, 41, 207-210. miller-butterworth c.m., murphy w.j., o’brien s.j., jacobs d.j., springer m.s., teeling e.c. (2007) a family matter: conclusive resolution of the taxonomic position of the long-fingered bats, miniopterus. molecular biology and evolution, 24, 1553-1561. mussi m. (2002) earliest italy. an overview of the italian paleolithic and mesolithic. springer, new york, 399 pp. niethammer j., krapp f. (2001) handbuch der säugetiere europas. bd. 4: fledertiere, teil i: chiroptera i. aula-verlag, wiebelsheim, pp. 603. noël f., chaut j.j., hinguant s. (2008) 11.000 ans d'histoire des chiroptères dans la grotte rochefort (mayelllle, france). symbioses, 21, 13-15. ochman k. (2003) late pleistocene and holocene bats (chiroptera) from the komarowa cave (cracowczestochowa upland, poland), preliminary results. acta zoologica cracoviensia, 46, 73-84. ochman k., wo�oszyn b.w. (2003) bats (chiroptera). in: valde-nowak p., nadachowski a., madeyska t. (eds), ob�azowa cave. human activity, stratigraphy and palaeoenvironment. instytut archeologii i etnologii, polska akademia nauk, kraków, 118125. pasa a. (1953) primi risultati dell’indagine paleon 134 salari l., kotsakis t. tologica sui materiali scavati nelle grotte di s. cassiano (colli berici vicenza). annali dell’università di ferrara, scienze geologiche e paleontologiche, 1, 169-183. patriarca e., debernardi p. (2014) a checklist of bats (mammalia: chiroptera) of aosta valley (nw italy). in: imperio s., mazzaracca s., preatoni d.g. (eds), ix congresso italiano di teriologia, hystrix, italian journal of mammalogy, 25 (suppl.), 127. pazonyi p., kordos l., magyari e., marinova e., füköh l., venczel m. (2014) pleistocene vertebrate faunas of the süttö travertine complex (hungary). quaternary international, 319, 50-63. piksa k., wo�oszyn b.w. (2001) postglacial bat remains from the polish tatra caves. lynx (praha), 32, 301-311. popov v.v. (2000) the small mammals (mammalia: insectivora, chiroptera, lagomorpha, rodentia) from cave 16 (north bulgaria) and the paleoenvironmental changes during the late pleistocene. in: ginter b., koz�owski j.k., laville l. (eds), temnata cave. excavation in karlukovo karst area, bulgaria, jagellonian university press, cracow, 159-240. popov v.v., ivanova t.i. ( 2002) comparative cranio metrical analysis and distributional patterns of medium-sized horseshoe bats (chiroptera: rhinolophidae) in bulgaria. folia zoologica, 51, 187200. rosina v.v. (2012) myotis cf. schaubi and other bats from the pleistocene of the central altai mts., russia. vespertilio, 16, 271-278. rossina v.v. (2006) bats as an indicator of human activity in the paleolithic, using the example of denisova cave, northwestern altai. paleontological journal, 40 (suppl. 4), 5494-5500. ruedi m., walter s., fischer m.c., scaravelli d., excoffier l., heckel g. (2008) italy as a major ice age refuge area for the bat myotis myotis (chiroptera: vespertilionidae) in europe. molecular ecology, 17, 1801-1814. rydell j. (1993) eptesicus nilssonii (keyserling and blasius, 1939). mammalian species, 430, 1-7. rydell j., strann k.b., speakman j.r. (1994) first record of breeding bats above the arctic circle: northern bats at 68-70° n in norway. journal of zoology (london), 233, 335-339. sala b. (2005) mammalian faunas and environment from the würmian glacial maximum of the italian peninsula (approx. 22±2 ka cal bp). annali dell’università degli studi di ferrara, museologia scientifica e naturalistica, spec. vol. 2005, 125129. salari l. (2004) contributo alla conoscenza dei resti ossei dei chirotteri. grotte e dintorni, 8, 45-54. salari l. (2009) i chirotteri del tardoglaciale e olocene antico della grotta del santuario della madonna a praia a mare (calabria, italia meridionale). atti del museo civico di storia naturale di trieste, 54, 147 -164. salari, l. (2010) late glacial bats from the “m” layers of the arene candide cave (liguria, italy). rivista italiana paleontologia stratigrafia, 116, 119-138. salari l., di canzio e. (2009) i chirotteri del pleistocene superiore e olocene antico di alcune grotte dell’italia centro-meridionale. bollettino del museo civico di storia naturale di verona, 33 (geologia paleontologia preistoria), 3-25. salari l., kotsakis t. (2011) late pleistocene and holocene bats of latium (central italy). il quaternario, italian journal of quaternary sciences, 24, 121-129. salari l., kotsakis t., petronio c. (2013) early pleistocene bats from pirro nord (apulia, southern italy). palaeontographica, abt. a 298, 55-72. salari l., silvestri l. (2015) holocene bats (mammalia, chiroptera) from five caves of central apennines (italy). barbastella, journal of bat research, 8, 2741. sevilla p. (2016) bats from azokh caves. in: fernández-jalvo y., king t., yepiskoposyan l., andrews p. (eds), azokh cave and the transcaucasian corridor, springer, 177-189. sevilla garcía p. (1988) estudio paleontológico de los quirópteros del cuaternario español. paleontologia i evolució, 22, 113-233. sgi (1960) servizio geologico d’italia, carta geologica d’italia scala 1:100.000, foglio 170 (terracina). simmons n.b. (2005) order chiroptera. in: wilson d.e., reeder d.a.m. (eds), mammal species of the world. a taxonomic and geographic reference. 3rd ed., johns hopkins university press, baltimore, vol. 1, 312-529. sommer r., nadachowski a. (2006) glacial refugia of mammals in europe: evidence from fossil records. mammal review, 36, 251-266. spena m.t., agnelli p., di maita j., grasso r., reitano a., santoro c., salari l. (2017) pleistocene bats (mammalia, chiroptera) from grotta dei pipistrelli (southeastern sicily, italy). preliminary report. barbastella, journal of bat research, 10, doi: 10.14709/barbj.10.1.2017.06. spitzenberger f., helversen o. von (2001) myotis capaccini (bonaparte, 1837) langfußfledermaus. in: niethammer j., krapp f. (eds), handbuch der säugetiere europas. bd. 4: fledertiere, teil i: chiroptera i. aula-verlag, wiebelsheim, 281-302. stewart j.r., lister a.m. (2001) cryptic northern refugia and the origins of the modern biota. trends in ecology and evolution, 16, 608-613. tang z., kotsakis t. (2008) tardiglacial micromammals of riparo salvini (latium, central italy). geologica romana, 41, 125-132. tata c., kotsakis t. (2005) italian fossil chiropteran assemblages: a preliminary report. geo. alp, 2, 53 -60. tiunov m.p. (2016) changes in the fauna of bats in the south of the russian far east since the late pleistocene. quaternary international, 425, 464-468. topál g. (1979) fossil bats of the rhinolophus ferrumequinum group in hungary (mammalia: chiroptera). fragmenta mineralogica et palaeontologica, 9, 61-101. topál g., ruedi m. (2001) myotis blythii (tomes, 1857) kleines maushor. in: niethammer j., krapp f. (eds), handbuch der säugetiere europas. bd. 4: 135 late pleistocene bat assemblage with eptesicus nilssonii from grotta del ..... fledertiere, teil i: chiroptera i. aula-verlag, wiebelsheim, 209-255. topál g., tusnadi g. (1963) data for craniometric investigation of myotis myotis borkh. and myotis oxygnathus montic. in hungary. annales historiconaturales musei nationalis hungarici, 55, 543549. vitagliano s., piperno m. (1991) lithic industry of level 27 beta of the fossellone cave (s. felice circeo, latina). quaternaria nova, 1, 289-304. vitagliano s., bruno m. (2012) late and final mousterian setting in the fossellone cave (latium, italy): patterns of settlement, micro-environmental factors and evidence of coloured material in a transitional context. quaternary international, 259, 48-58. wo�oszyn b.w. (1987) pliocene and pleistocene bats of poland. acta palaeontologica polonica, 32, 207 -325. 136 ms. received: july 3, 2017 final text received: november 20, 2017 salari l., kotsakis t. amq abs zuffetti et al tepro 257-260.pub available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 257 260 significance of the morphological and stratigraphic surfaces in the quaternary po plain: the san colombano tectonic relief (lombardy, italy) chiara zuffetti, riccardo bersezio, luca trombino dipartimento di scienze della terra, università degli studi di milano, milano, italy. corresponding author: c. zuffetti <chiara.zuffetti@unimi.it> abstract: the recent geological, geomorphological, pedological and structural surveys performed at the san colombano tectonic relief document a late quaternary tectonic activity of the structure, located at the po plain-northern apennine border in lombardy (italy). the new maps, corroborated with (palaeo-) geopedological analyses, allow to unravel the composite nature of the morphological and stratigraphic surfaces bounding the observed units and landforms, and to relate them to the climatic and tectonic events that interacted during the late quaternary at the apennine-po plain border. keywords: northern apennine, po plain, quaternary, san colombano hill, soil, stratigraphy 1. introduction the interaction between tectonics and climate cycles has determined the mobility of depositional settings at the border between the apennines and the po plain during the quaternary, which results in a great complexity of geomorphological and stratigraphic features. stratigraphic boundaries and morphological surfaces are fundamental elements to recognize the periods and sites of surface stabilization and pedogenesis (morphological surfaces) from those where mostly erosion and/or aggradation occur (stratigraphic boundaries). paleosol analysis helps to characterize these two different types of surfaces, which might represent also palaeoclimatic and palaeoenvironmental markers, providing additional chronological constraints to the quaternary geological and morpho-tectonic processes (costantini, 2017). hence, the integration between detailed geological mapping of the quaternary sediments and the sedimentological and geopedological characterization of the stratigraphic boundaries is necessary to unravel the origin of landscape in complex mobile settings. from this perspective we focus on the san colombano hill in the po plain of lombardy (fig. 1; desio, 1965), as one of the main evidences of late pleistocene n-apennine tectonics affecting the s-alpine sourced alluvial systems. here, the available regional geological maps (anfossi et al., 1971; boni, 1967) and pedological studies (ersaf, 2013) have never been integrated in a comprehensive quaternary stratigraphic framework, and the late quaternary geological evolution of the structure, mainly based on regional geomorphological studies (benedetti et al., 2003; burrato et al., 2003; pellegrini et al., 2003), is still under debate. starting from the new geological, geomorphological and structural surveys carried out on the hill (zuffetti et al., 2018), and accounting for the new geopedological data which have been recently submitted for publication, here we focus on the characterization of the stratigraphic boundaries and morphological surfaces of the san colombano hill area. the main aim is to highlight their role as indicators of the incremental morpho-tectonic changes at the origin of the hill landforms during the late quaternary, and to unravel the most effective controlling factors on their origin. 2. materials and methods detailed geological and geomorphological mapping at 1:10.000 scale have been carried out in the san colombano hill area. ubsu (issc, 1987) classification was applied when possible to the quaternary continental units, following the criteria adopted in the recent mapping projects of italy. sedimentological, geomorphological and structural analyses accompanied field surveys and the results are presented in zuffetti et al. (2018). the geopedological characterisation of the stratigraphic boundaries relies on a distributed mapping of soil textures and colours, integrated by detailed analyses on five soil profiles, selected as reference for the features of the top boundary of the mapped late pleistocene stratigraphic units and for the most prominent morphological surfaces. geopedological field description, laboratory analyses and micromorphological observations were performed following the conventions of wrb (2015), ministero per le politiche agricole (1999), stoops et al. (2010), respectively. age constraints are based on new and available osl and radiocarbon datings (baio et al., 2004; bersezio et al., 2004; panzeri et al., 2011). 3. results the san colombano hill exposes the uplifted and folded marine miocene and calabrian units (sant’agata fossili marls and san colombano fm.; ‘m’ in fig. 2), unconformably overlain by the late pleistocene alluvial https://doi.org/10.26382/aiqua.2018.aiquaconference pedogenised and deformed deposits (cascina parina synthem, ‘cps’ and invernino synthem, ‘ins’, fig. 2). the sequence is in turn modelled by the late pleistocene to holocene processes and covered by sediments, which belong to the monteleone synthem (‘mls’, fig. 2) and are located along the slopes and within the valley network of the hill. the eastern sectors of the hill consist of fault blocks (fig. 2) laterally dissected by conjugate faults while the northern and southern slopes develop from wnw-ese directed normal faults stepping towards the adjacent plain (zuffetti et al., 2018). the lower boundary of cps (late pleistocene) is a high rank angular unconformity, composed by the progressive terracing of cps alluvial systems on the uplifting substratum (zuffetti et al., 2018). this middle-late pleistocene unconformity encompasses the regional regressive sedimentary cycles recorded in the subsurface of the central po plain (ghielmi et al., 2013). geopedological analyses performed on both cps, ins and on the loess deposits at their top, result in the identification of some surfaces of morphological, tectonic and depositional stabilization, differently preserved and dissected throughout the san colombano hill. the most complete sequence is observed in the lowermost hill sector, where a highly developed and red paleosol is covered by two stacked loess-paleosols to soil sequences (buried loess l1, exposed loess l2; fig. 2). the oldest loess (l1) is ascribed to the end of cps depositional cycle (pre-lgm), the youngest (l2) to the end of lgm, post-dating the deposition of ins. age constraints are provided by osl and radiocarbon datings (panzeri et al., 2011; bersezio et al., 2004; zuffetti et al., 2018). the associated soils (fig. 2) mark two phases of climatic stabilization under interglacials. a comparable interpretation was proposed for soils and paleosols described on loess covers at both the northern (zerboni et al., 2014) and southern fringes of the po plain (cremaschi et al., 2015; maestrelli et al., 2018). hence, the surface at the top of cps in the lowermost hill sector corresponds to a geomorphic surface of stabilization (s, fig. 2), covered by loess l2. a comparable interpretation is deduced from the sections studied at the uppermost fault blocks, where the late-lgm l2 loess covers a geomorphic surface of planation, subsequently stabilized (‘e+s’ surface, fig. 2). layers of colluvium reworking pedorelicts of highly weathered material rest on the unconformity, below the loess cover of the intermediate fault block (fig. 2). in the northern fault block, both alluvial ins and l2 are preserved and no paleosols were observed (fig. 2); the evidence of paleosol redeposition in this interval consists of colluvial sediments derived from developed and hydromorphic paleosols, interposed between alluvial ins and l2 by means of a low rank stratigraphic boundary (fig. 2). in this sector, the unconformity bounding the bottom of ins is a high rank erosional surface, resulting from alluvial terracing during the lgm depositional cycle, as confirmed by stratigraphic correlation to the adjacent dated sediments north of the relief (bersezio et al., 2004; zuffetti et al., 2018). 4. discussion and conclusions the new maps (zuffetti et al., 2018), combined with detailed pedo-stratigraphic analyses, provide a useful framework to discuss the interaction between tectonic 258 fig. 1 location of the san colombano hill in the structural framework of the central po plain (italy). the san colombano structure (sc) corresponds to one of the northernmost thrusts of the buried front of the northern apennine emilia arc. buried n-apennine thrusts from bigi et al. (1990); buried s-alpine thrusts simplified from fantoni et al. (2004). zuffetti c. et al 259 and climatic controls at the origin of the stratigraphic and morphological surfaces that characterize the san colombano hill. the late quaternary synthems mapped on the hill are bounded by composite unconformities that originated in part during tectonic displacement and, in part, during periods when specific sites where stabilized. in situ paleosols testify the existence of locally non-erosional unconformities during the late pleistocene, related to surface stability, where the main controlling factor was climatic. l1 and l2 loess are mostly preserved at these sites. conversely, truncated and redeposited paleosols dominate in sites of active tectonic displacement, as observed in the easternmost fault blocks; here, latest pleistocene tectonic increments (zuffetti et al., 2018) acted in soil erosion and mobilization. the basal unconformity of the lgm ins is composed by erosional surfaces which join progressively deposited along the dissected fault blocks. the present work outlines the importance of considering how tectonics interacts with climate-driven depositional and soil-forming processes to produce stratigraphic and geomorphological surfaces. their significance is relevant for mapping purposes and to constrain correlation of continental successions within the stratigraphic framework of the late pleistocene po basin infill. the regional meaning of the correlative surfaces detected in the subsurface of the basin is the object of the wider ongoing research. acknowledgments the research was supported by carg funds to rb. the paper is a part of cz phd project, under supervision of rb. references anfossi g., desio a., gelati r., laureri s., petrucci f., venzo s. (1971) note illustrative della carta geologica d’italia. f. 60, piacenza. baio m., bersezio r., bini a. (2004) assetto geologico della successione quaternaria nel sottosuolo tra melegnano e piacenza. il quaternatio, 17, 355359. benedetti l.c., tapponnier p., gaudemer y., manighetti i. (2003) geomorphic evidence for an emergent active thrust along the edge of the po plain: the broni-stradella fault. journal of geophysical research, 108, 2238, doi:10.1029/2001jb001546. bersezio r., pavia f., baio m., bini a., felletti f., rodondi c. (2004) aquifer architecture of the quaternary alluvial succession of the southern lambro basin (lombardy italy). il quaternario, 17, 361-378. bigi g., cosentino d., parotto m., sartori d., scandone p. (1990) structural model of italy. progetto finalizzato geodinamica, cnr. boni a. (1967) note illustrative della carta geologica morphological and stratigraphic surfaces in the po plain fig. 2 n-s and e-w sections showing the relations between the late quaternary soils and paleosols and stratigraphic boundaries across the san colombano hill. m: undifferentiated marine units (upper miocene to calabrian); cps: cascina parina synthem (late pleistocene); l1: pre-lgm loess; ins: invernino synthem (latest pleistocene); l2: late-lgm loess; mls: monteleone synthem (late pleistocene-holocene). thickness of the lines representing the stratigraphic boundaries is proportional to their rank. s buried and/or exposed stabilization surface; e erosional surface. d’italia. f. 59, pavia. burrato p., ciucci f., valensise g. (2003) an inventory of river anomalies in the po plain, northern italy: evidence for active blind thrust faulting. ann. geophys. 46 (5), 865-882. costantini e.a.c. (2017). paleosols and pedostratigraphy. applied soil ecology, 1-4. doi:10.1016/j.apsoil.2017.09.021. cremaschi m., zerboni a., nicosia c., negrino f., rodnight h., spötl c. (2015) age, soil-forming processes, and archaeology of the loess deposits at the apennine margin of the po plain (northern italy): new insights from the ghiardo area. quaternary international, 376, 173-188. doi: 10.1016/j.apsoil.2017.09.021. desio a. (1965) i rilievi isolati della pianura lombarda ed i movimenti tettonici del quaternario. rendiconti dell’istituto lombardo di scienze e lettere, a, 881894. ersaf (2013) carta dei suoli in scala 1:50.000 della pianura e collina lombarda. (http://www.ersaf. lombardia.it/upload/ersaf/ soilqualimon/pdf/qdr_110.pdf) fantoni r., bersezio r., forcella f. (2004) alpine structure and deformation chronology at the southern alps-po plain border in lombardy. bollettino della società geologica italiana, 123, 463-476. ghielmi m., minervini m., nini c., rogledi s., rossi m. (2013) late miocene-middle pleistocene sequences in the po plain-northern adriatic sea (italy): the stratigraphic record of modification phases affecting a complex foreland basin. marine and petroleum geology, 42, 50-81. doi:10.1016/j.marpetgeo.2012.11.007. international subcommission on stratigraphic classification (1987). unconformity-bounded stratigraphic units. geological society of america bulletin, 98, 232-237. maestrelli d., benvenuti m., bonini m., carnicelli s., piccardi l., sani f. (2018) the structural hinge of a chain-foreland basin: quaternary activity of the pede-apennine thrust front (northern italy). tectonophysics, 723, 117-135. doi:10.1016/j.tecto.2017.12.006. ministero per le politiche agricole (1999) metodi ufficiali di analisi fisica del suolo. d.m. del 13 settembre 1999. gazz. uff. suppl. ordin. n. 248 del 21.10.99. panzeri l., zembo i., bersezio r., martini m. (2011) calibration of osl data: mismatch between stratigraphy and osl chronology pf sediments from the po plain. il quaternario, 24, 114-116. pellegrini l., boni p., carton a. (2003) hydrographic evolution in relation to neotectonics aided by data processing and assessment: some examples from the northern apennines (italy). quaternary international, 101-102, 211-217. doi:10.1016/s1040-6182(02)00103-9. stoops g., marcelino v., mees f. (2010) interpretation of micromorphological features of soils and regoliths. elsevier, oxford, uk. wrb iuss working group (2015) world reference base for soil resources 2014, update 2015 international soil classification system for naming soils and creating legends for soil maps, world soil resources reports. fao, rome. zerboni a., trombino l., frigerio c., livio f., berlusconi a., michetti a.m., rodnight h., spotl c. (2014) the loess-paleosol sequence at monte netto: a record of climate change in the upper pleistocene of the central po plain, northern italy. journal of soils and sediments, 15, 1329-1350. doi:10.1007/s11368-014-0932-2. zuffetti c., bersezio r., contini d., petrizzo m.r. (2018) geology of the san colombano hill, a quaternary isolated tectonic relief in the po plain of lombardy (northern italy). journal of maps, 14, 199-211. doi:10.1080/17445647.2018.1443166. 260 zuffetti c. et al ms. received: may 21, 2018 final text received: may 23, 2018 imp.05petronio the deposit of the late pleistocene from avetrana (taranto, southern italy): biocrhonology and palaeoecology carmelo petronio1, flavio bellardini1, marta arzarello2, claudia bedetti1, luca bellucci1, alessia cipullo1, giuseppe di stefano1, luca pandolfi1, marco pavia3, mauro petrucci3, raffaele sardella1, & leonardo salari1 1 dipartimento di scienze della terra, sapienza, università di roma 2 dipartimento di biologia ed evoluzione, università di ferrara 3 dipartimento di scienze della terra, università di torino abstract: c. petronio, f. bellardini, m. arzarello, c. bedetti, l. bellucci, a. cipullo, g. di stefano, l. pandolfi, m. pavia, m. petrucci, r. sardella & l. salari, the deposit of the late pleistocene from avetrana (taranto, southern italy): biocrhonology and palaeoecology. (it issn 0394-3356, 2008). the analytical study of the vertebrate assemblage from the late pleistocene, found in a karstic cavity (which lays on a calcarenite near avetrana, taranto, southern italy), allows us to reduce the chronological span during which the fossil remains were deposited. in particular, some circumstances allowed the authors to collocate the fauna in a temporal span from 100.000 to 80.000 years (faunal unit of melpignano petronio et al., 2007). the findings show the occurence of hystrix vinogradovi (never found in italy during the central part of the late pleistocene), the even more rare presence of hippopotamus amphibius in the same period, the discovery of cervus elaphus elaphus, the archaic morphology of dama dama dama, the dimension of bos primigenius. finally the finding of an archaic mousterian tool is also recorded. the analysis of the avifauna and of the mammal fauna allowed us to retrace the habitat of that period. riassunto: c. petronio, f. bellardini, m. arzarello, c. bedetti, l. bellucci, a. cipullo, g. di stefano, l. pandolfi, m. pavia, m. petrucci, r. sardella & l. salari, il deposito del pleistocene superiore di avetrana (taranto): biocronologia e paleoecologia. (it issn 0394-3356, 2008). lo studio analitico di un giacimento a vertebrati del pleistocene superiore rinvenuto in una cavità carsica impostata in una calcarenite nei dintorni di avetrana (taranto, sud italia) permette di restringere l’intervallo cronologico in cui si sono depositati i resti fossili. in particolare la presenza di hystrix vinogradovi, mai segnalata in italia nella parte centrale del pleistocene superiore, la presenza sempre più rara di hippopotamus amphibius nello stesso periodo, la segnalazione di cervus elaphus elaphus, la morfologia arcaica di dama dama dama e le dimensioni di bos primigenius orientano gli autori a collocare la fauna in un intervallo temporale compreso fra 100.000 e 80.000 anni (unità faunistica di melpignano, petronio et al., 2007). l’analisi dell’avifauna e della mammalofauna ha infine permesso di ricostruire l’habitat di tale periodo. keywords: vertebrates, late pleistocene, biochronology, palaeoecology. parole chiave: vertebrati, pleistocene superiore, biocronologia, paleoecologia. il quaternario italian journal of quaternary sciences 21(2), 2008 409-422 introduction the late pleistocene vertebrate assemblage, object of the present paper, was found in an abandoned quarry near avetrana, a small town in the eastern area of taranto, more precisely, in the northern part of the salento peninsula (southern italy). it has already been the topic of an earlier publication (sardella et al., 2005). the detrital sediments are rich in bone remains, notably of mammals, which are included inside a karstic cavity and which originated during the pleistocene within rocks attributable to the plio-pleistocene formation of the so called “calcareniti di gravina”. the cavity is filled with this material which was carried by alluvial flows, very likely the consequence of numerous exceptional events (which were distinct but chronologically coeval, from a geological point of view). the “calcarenite di gravina” is attributed to the early pleistocene, it is at least 15 meters thick and composed by a compact yellowish bio-calcarenite, rich in molluscs and echinids. it was deposited in a coastal marine environment, with a temperate climate and shallow waters (ciaranfi et al., 1979). a preliminary analysis of the avifauna, and chiefly the biochronology of the mammal-fauna found in the cavity (sardella et al., 2005), allowed us to assign a quite large chronological span to the deposition of sediments, although pertaining to the late pleistocene. in this paper we consider the detailed analysis of every single taxon, and mainly the evolutive trend of the mammal-fauna, in the pursuit of further reducing this interval of time. we refer particularly to bos primigenius which is by far the most numerous mammal present. stratigraphic notes we can identify 9 layers and 2 pockets (fig. 1) in the filling of the karstic fissure where the bone remains were discovered. these sediments may be divided into two groups: the upper one fills the main karstic cavity and includes 9 levels; while the lower one forms the layer 0 which fills a network of small basal fissures. 410 c. petronio et al. layer 0 is filled with orange-yellow nonlaminated sandy clays containing small and medium size fossil vertebrate remains. on the other hand, the main cavity is filled with a series of laminated sediments and it is between 4,5 to 5,5 meters thick. it is possible to draw up a list of the most important features of the different layers identified, on the base of the stratigraphic elements observed in the cavity and also on the base of the systematic study carried out on the paleontological contents of the deposits. from the bottom to the top of the karstic cavity the following fossiliferous levels are present: layer 0: this level is composed of small irregular fissures which, as already mentioned, are filled by sandy clays rich in small fossil vertebrate remains. birds are chiefly represented by anterior limb bones belonging to perdix perdix, columba livia, athene noctua, and pyrrhocorax graculus, while mammals are represented by teeth. in particular, we found remains of erinaceus europaeus, well-preserved mandibles of terricola savii, molars of hystrix vinogradovi, cranial fragments, mandibles and limb bones of lepus cf. europaeus and of oryctolagus cuniculus, and some fragments of felis silvestris. layer 1: this level is formed by an uninterrupted stratum of calcareous pebbles and, above it, by a thin deposit (30 cm) constituted by argillaceous sand containing rare clayey pebbles (which are visibly altered) and a few fossil bones of bos primigenius. layer 2: the level is formed by a 20 cm thin deposit of sandy clay including numerous bone remains belonging to: vulpes vulpes, canis lupus, crocuta crocuta, lynx lynx, stephanorhinus hemitoechus, bos primigenius, dama dama dama, cervus elaphus elaphus, hippopotamus amphibius (fig. 2, a). layer 3: this level is formed by 20 cm of argillaceous sand containing rare calcareous pebbles with only a few bones of lepus cf. europaeus, vulpes vulpes, meles meles, canis lupus, bos primigenius, dama dama dama and cervus elaphus elaphus. layer 4: this level is separated from the underlying layer by an erosional surface marked by a stratum containing calcareous pebbles and rare bones; this layer is 20 cm thick and it is formed by sandy clay containing calcareous pebbles and a few remains of lepus cf. europaeus, vulpes vulpes, canis lupus, bos primigenius, dama dama dama, and cervus elaphus elaphus. layer 5: this deposit is 140 centimeters thick. it is composed by argillaceous sand containing very numerous bones and rare calcareous pebbles. the level is characterized by a basal stratum with pebbles and bones and by a sandy lens, containing rare fossil remains, which lays 20 centimeters above the base of this deposit. the mammal remains (fig. 2, b) are represented by vulpes vulpes, canis lupus, dama dama dama, cervus elaphus elaphus, crocuta crocuta, sus scrofa, lepus cf. europaeus (at the bottom of the level) and mainly by bos primigenius. fig. 1 stratigrafical succession of deposit. successione stratigrafica del deposito. layer 6: this 20 cm sandy level is above all formed by bone remains (fig. 2, c) of vulpes vulpes, canis lupus, bos primigenius, dama dama dama, cervus elaphus elaphus, sus scrofa, hippopotamus amphibius, and stephanorhinus hemitoechus. a single mousterian lithic artefact was also discovered in this layer. layer 7: this argillaceous layer which is 40 cm thick, contains numerous bones and large calcareous pebbles, mainly at its base. the species represented (fig. 2, d) are: vulpes vulpes, canis lupus, crocuta crocuta, stephanorhinus hemitoecus, abundant bos primigenius, cervus elaphus elaphus, dama dama dama, and a phalanx of megaloceros sp. layer 8: this level is formed by a 75 cm thick argillaceous deposit, separated from the underlying layer by a base which is particularly rich in bones of vulpes vulpes, canis lupus, lynx lynx. we also found a calcaneum belonging to panthera spelaea, sus scrofa, abundant bos primigenius, cervus elaphus elaphus, and dama dama dama (fig. 2, e). layer 9: this 70 cm thick argillaceous level contained very rare bones, which are quite decalcified. fauna analysis. aves birds are represented by a few remains, which are extremely fragmented and generally in not good condition. the remains are slightly more frequent at level 0, while they are sporadic in the upper levels. 411the deposit of the late pleistocene ... falconiformes: accipitride aquila sp. the discovery of the third phalanx of the first finger shows the presence of a large accipiter of the genus aquila. its dimensions are smaller compared to aquila chrysaetos and they are comparable to other european species of this genus, in particular to a. celiaca, a. nipalensis and a. rapax. it is very difficult to distinguish the posterior phalanxes of the genus aquila, especially if we deal with only one sample (louchart et al., 2005). therefore, we prefer to attribute the phalanx found to aquila sp. galliformes: phasianidae perdix perdix (linnaeus, 1758) the presence of this species is seen in one single fragment of the proximal part of the humerus, in one pneumatic fossa, and in the incisure capitis, which is typical of perdix perdix. gruiformes: otididae otis tarda linnaeus, 1758 one complete right ulnar os carpi shows the presence of this big gruiformes. its morphological features and its large dimension allow us to refer at otis tarda instead of genus grus. columbiformes: columbidae columba livia gmelin, 1789 this is the most frequent taxon found in the avetrana assemblage. it was found at every level. in fig. 2 graphic of taxa percentage for layers. b. p. = bos primigenius; c. c. = crocuta crocuta; c. e. = cervus elaphus elaphus; c. l. = canis lupus; d. d. = dama dama dama; h. a. = hippopotamus amphibius; l. e. = lepus cf. europaeus; l. l. = lynx lynx; p. l. = panthera leo; s. h. = stephanorhinus hemitoechus; s. s. = sus scrofa; v. v. = vulpes vulpes. percentuale dei taxa nei singoli livelli. b. p. = bos primigenius; c. c. = crocuta crocuta; c. e. = cervus elaphus elaphus; c. l. = canis lupus; d. d. = dama dama dama; h. a. = hippopotamus amphibius; l. e. = lepus cf. europaeus; l. l. = lynx lynx; p. l. = panthera leo; s. h. = stephanorhinus hemitoechus; s. s. = sus scrofa; v. v. = vulpes vulpes. particular, we found several elements of the post-cranial skeleton which show all the typical features of the columbidae family. the dimension of the remains and their morphological features allow us to ascribe them to columba livia. strigiformes: strigidae athene noctua (scopoli, 1769) the discovery of a only proximal portion of right tibiotarsus allows us to recognize the presence of athene noctua in the fossil assemblage of avetrana. the general features correspond with that of the strigidae family. the dimension and the morphology demonstrate that we are dealing with athene noctua, following the descriptions of pavia & mourer-chauviré (2002). passeriformes: corvidae pyrrhocorax graculus (linnaeus, 1766) this species is the second species with the most remains found, after columba livia. it is present in several levels, but it is more frequent at level 0. the dimensions and morphology of the remains correspond with that indicated by tomek & bochensky (2000). pyrrhocorax pyrrhocorax (linnaeus, 1758) we found a left almost complete humerus of corvidae which shows the stocky structure of the genus pyrrhocorax. however, the dimensions are clearly greater compared with that of pyrrhocorax graculus, allowing us to ascribe these remains to p. pyrrhocorax, according with tomek & bochnesky (2000). mammalia (fig. 3) insectivora: erinaceidae erinaceus europaeus linnaeus, 1758 the presence of this species is demonstrated by the finding of two molars, one m2 and one m3, whose dimensions and morphological features allow us to identify the systematics attribution. rodentia: arvicolidae terricola savii (de sélis longchamps, 1838) we identified 7 well-preserved mandibles of this species along with several isolated teeth, among them there are numerous m1. this material is attributed to the species on the basis of morphology and dimensions of m1. hystricidae hystrix vinogradovi argyropulo, 1941 a porcupine form, visibly smaller than the modern hystrix cristata, is evidenced by the discovery of some teeth, one m1, two m2 and one m3. the morphology of the dental structure (fig. 4, 4) seems to be simpler than that of the modern hystrix cristata, a species imported in italy during the roman age (petronio et al., 2005). hystrix vinogradovi is different from the other european hystricidae, both from the fossil hystrix refossa and from the actual hystrix cristata, for its smaller dimension. according to weers (2005), who hypothesizes that hystrix vinogradovi can be synonymous with both the fossil and living hystrix (acanthion) brachyura (from south-eastern asia), this species has been present in the occidental euro-asian region since the early pleistocene (hungary jànossi, 1972) to the late pleistocene (france schweitzer, 2002). however, hystrix vinogradovi, in addition to the localities mentioned by weers (2005), has been cited in europe also in the tg 10-11 strata, referred to ois 10 in the “trinchera del ferrocarril”, in the sierra of atapuerca, in spain (made et al., 2003); as well as in the late travertine stones referred to the eemian age (ois 5), in burgtonna (germany kolfschoten, 2000) and in the strata referred to mikulino integlacial (eemian, ois 5) of the makhnevskaya cave in the urals mounts (russia kosintsev, 2007). hystrix vinogradovi was found in italy in the ossiferous breccia of “monte del cros”, in the piedmont region, deriving from the middle pleistocene, and in the site of “montignoso”, in tuscany, deriving from the middle-late pleistocene (kotsakis et al., 2003). lagomorpha: leporidae lepus cf. europaeus we found numerous remains of this taxon, among them there are several limb bones, skull fragments, and some mandible fragments. the morphological and biometrical features of these remains are referable to the 412 fig. 3 percentage of taxa in avetrana mammalfauna. percentuale dei taxa nella mammalofauna di avetrana. c. petronio et al. common hare (lepus europaeus pallas, 1778), such as already described by miller (1912), ognev (1935) and iacoangeli (1996). as a matter of fact, recently the italian hare lepus corsicanus (de winton 1898) has been considered as a valid species. nowadays, this taxon lives in central, southern italy and sicily (trocchi & riga, 2002). for this reason, it seems reasonable to refer the hare fossil remains of avetrana to lepus cf. europaeus, and only further osteometric studies will enable to clear its taxonomic position. oryctolagus cuniculus (linnaeus, 1758) only a few fragments of limb bones and some sporadic teeth can be ascribed to this species. the dimensions and the morphological features of the teeth are typical of the wild rabbit features. carnivora: canidae canis lupus linnaeus, 1758 canis lupus is the best representative carnivorous of the avetrana site, both for the frequency and the abundance of its remains. various skeletal elements of this predator (almost all of which from layer 8) were found (fig. 2, e). we specifically identified teeth and phalanxes. complete long bones are absent, while we found quite numerous fragments of the articular epiphyses. almost all the remains were attributed to adult of large size, from the dental wear and the fusion of the articular epiphyses. there was only a mandibular fragment attributable to a young individual. the better preserved elements are some maxillary fragments (fig. 4, 3), numerous carnassial teeth, and first maxillary molars with well-preserved main cusps, inferior canine and carnassial teeth and mandible fragments. the other remains found are distal epiphyses of humerus, some first phalanxes, fragmented distal epiphyses of femur and tibia, one almost complete astragalus, distal epiphyses of metacarpus and metatarsus. vulpes vulpes (linnaeus, 1758) vulpes vulpes remains are relatively scarce, but they are present in all the layers. these remains are essentially constituted of teeth (one complete canine tooth with its root, and three first maxillary molars); other remains are constituted by a distal epiphysis of tibia, one fragmented distal epiphysis of femur which is very damaged, and by an complete distal epiphysis of humerus. the dimensions and the morphological features are always compatible with that of the species. mustelidae meles meles (linnaeus, 1758) remains referable to this small carnivorous were found in layer 3. they are exclusively composed by maxillary bones, some of which still retain well-preserved teeth. we discovered a maxillary bone with undamaged p4 and m1 (the wear of the dental cusps is quite pronounced, and indicates an adult age), a left maxillary bone with the alveoli of the three incisors, the canine and the first two premolars, and a fragment of the right zygomatic bone. all these skeletal remains are probably referable to the same specimen. 413 fig. 4 panthera spelaea: 1, calcaneum. crocuta crocuta: 2, carnassial. canis lupus: 3, maxillary fragment. hystrix vinogradovi: 4, upper molar. panthera spelaea: 1, calcagno. crocuta crocuta: 2, ferino. canis lupus: 3, frammento di mascellare. hystrix vinogradovi: 4, molare superiore. the deposit of the late pleistocene ... hyaenidae crocuta crocuta (erxleben, 1777) the presence in the deposit of this great predator is found in several layers, always through the discovery of teeth, among which an upper carnassial (found in layer 5) is particularly revealing. the carnassial (fig. 4, 2) is complete and very well-preserved, it is stout and well-developed. it definitely belongs to an adult subject with the typical features of crocuta. in fact, the protocone is inclined forward, the parastylus is small, welldeveloped and laterally slightly worn, the paracone along with the metacone are significantly long. the crown wear is mostly concentrated on the side of the tongue of cusps. felidae lynx lynx (linnaeus, 1758) very rare fragments of long limb bones, along with a premolar tooth can be ascribed to this felid. felis silvestris schreber, 1777 we found only a lower premolar, one first phalanx and some fragmented limb bones referable to this species. panthera spelaea (goldfuss, 1810) in the faunal assemblage the presence of this species is evidenced by the discovery from layer 8 of a fragmented calcaneum (fig. 4, 1) and of a proximal portion of the third metatarsal bone which is particularly stout. on the calcaneum the lion’s typical irregular protuberance is well noticeable; the distal portion is more fragmented, lacking in a part of the articular portion of the tarsal elements, and in the sustentaculum tali area. only the internal part of the tendinous splint is present alongside the lateral margin, due to the lack of the part which overhangs the sustentaculum tali. along the dorsal margin the peculiar coracoid process and the relative articular surface and the astragalus are well-preserved, as well as the underlying system of depressions which originates from the calcaneal sulcus separating the different articular facets. perissodactyla: rhinocerothidae stephanorhinus hemitoechus (falconer, 1868) the only representative of perissodactyla at avetrana is this medium-large bicorn rhinoceros. it was recognized from the discovery of three teeth: one third lower fragmented molar (fig. 5, 2), one lower premolar (fig. 5, 1) and one well-preserved superior deciduous premolar. the roots of the third lower fragmented molar are almost completely missing; part of the wall at the level of the neck is fractured and the lingual portion of the crown is absent, or visibly damaged. the tooth, with its typical double-c shape, which is peculiar for the lower molar of stephanorhinus, presents a stout, well-developed wall. the enamel is only partially worn, merely at the summit portion, especially on the labial side of the crown. this molar, along with the inferior premolar, presents a wrinkled, rough surface due to the presence of a dense system of stripes and protuberances. this feature is peculiar of the stephanorhinus hemitoechus 414 fig. 5 stephanorhinus hemitoechus: 1, lower premolar, 2, lower molar. hippopotamus amphibius: 3, second phalanx. stephanorhinus hemitoechus: 1, premolare inferiore, 2, molare inferiore. hippopotamus amphibius: 3, seconda falange. (guerin, 1980; lacombat, 2005; billia and petronio, 2007) and it is useful to distinguish this species from stephanorhinus kirchbergensis. the second superior premolar belongs to a young adult individual (from the state of the crown wear). the roots are present, even if lacking in their apexes, the neck is well visible and complete, alongside all the tooth perimeter. the crown is essentially intact, basically worn only in its central part. stephanorhinus sp. a juvenile calcaneum, whose top is missing, along with a second quite fragmented metatarsal bone, with c. petronio et al. the only proximal epiphysis, can be referable to this genus. the juvenile calcaneum was discovered at layer 6 and is in good condition, except for its upper side which is absent because of the non-fusion with the central body. the articular surfaces, along with the other tarsal bones, are all complete and evident, the whole body appears complete, presenting only limited damaging. artiodactyla: hippopotamidae hippopotamus amphibius linnaeus, 1758 a fragmented diaphysis of the right humerus and a second phalanx (fig. 5, 3) are the only elements which testify to the presence of hippopotamus in the avetrana faunal assemblage. the fragmented humerus is particularly interesting; the fracture is at the level of the deltoid protuberance, the proximal portion is absent, while the epicondylar crest seems to be well-developed. we can note some traces of fractures at the base of this bone, mainly at the superior part of the epitrochlea. in fact we discovered some possible fractures which, maybe, were provoked in order to extract the medulla from this long bone. the remarkable stoutness of the two bones which were found, along with their morphological features, leads us to believe they pertain to this species, after the comparison with analogous long bones deriving from middle pleistocene sites. suidae sus scrofa linnaeus, 1758 this species is represented by a few remains, only from layer 5, 6 and 8. these remains are all in a good condition of preservation and are referable to adult subjects. they are especially teeth, among them there are two male upper canine teeth, and three right molars still found in an anatomical connection. the molar characteristic mammillary tuberosities, which allowed us to easily identify this species, are well visible and present the evidence of protracted wear, chiefly in the first molar. other two remains, from layer 8, are a fragmented second phalanx and a fragment of the distal epiphysis of the third, or fourth, metapodial bone. cervidae dama dama dama (linnaeus, 1758) the presence of this cervid in the deposit is demonstrated by the find of several skeletal elements. we found in particular teeth, phalanxes, and long bone fragments, mainly metapodial bones and articular epiphyses. we did not find complete long bones, while many elements have to be ascribed to young subjects, because of their dimensions and the state of the epiphyseal fusion. the number of teeth is considerable. some of them still adhere to the maxillary and mandibular bones. from a general point of view, all the teeth are well-preserved, except for some elements which are fragmented or covered with calcareous concretions. both the enamel folds, and the infundibula among the cusps, which are indispensable for the identification of this species and to distinguish dama dama dama from cervus elaphus, are evident. the fourth lower premolar is slightly molarized and the anterior molar cingula are well pronounced, including the m3 cingula (fig. 6, 4) where the posterior cingulum is also visible. these features allow us to deduce the primitiveness of this fallow deer compared to the last shapes found in various peninsula deposits. among the long bones, a fragmented femur, some metacarpal diaphyses, an almost complete metacarpus, a distal epiphysis of the left humerus, two young distal epiphyses of radii, and some phalanxes, are of particular interest. cervus elaphus elaphus linnaeus, 1758 the presence of red deer is constant, at every stratigraphyc layer. this species is the best representative after bos primigenius; only in layer 2 and 7 red deer seems to be more copious. most of the remains are teeth (fig. 6, 5), some of which are deciduous, and phalanxes. complete long bones are absent, while the epiphyses and the fragments of articular portions are numerous. some elements are referable to young individuals. the remains of antlers have quite evident grooves. they are essentially some fragments of the basal portions, with brow tine, bez tine and trez tine, this latter is close to the other two tines. this morphological characteristic allows us to ascribe these remains to a modern form of red deer. megaloceros sp. we found a few remains of this genus at layer 7, among them there is a first phalanx which clearly presents the morphology of a cervid of large dimension. bovidae bos primigenius bojanus, 1827 this bovid is the best represented species in the site of avetrana. its bones are all of large dimension and were found at all the stratigraphyc layers, where they represent the most frequent and numerous specimens. the largest part of the remains is composed of long bones, vertebrae, ribs, phalanxes and teeth (fig. 6, 1-2-3). except for a limited number of elements, which are referable to young subjects, almost the whole of the bones is attributable to adult and sub-adult specimens, in which the epiphyses are already completely knitted. as for the cranial elements, a lot of fragmented hemi-mandibles and frontal bones with horns (fig. 7) were discovered, among which some are ascribable to young subjects. the maxillary bones were very rarely found, often they are fragmented and frequently only constituted by the alveolar portions of the teeth. the teeth are the most recurrent remains. on the whole they are in very good condition and mostly belong to adult individuals. the best preserved bones are represented by complete skeletal elements of long bones: one of which is a tibia, some are radii, there are numerous metacarpi (some are definitely stout and therefore ascribable to male individuals), there are several metatarsi, many car415the deposit of the late pleistocene ... pal and tarsal remains and very copious first, second and third phalanxes (numerous are still in an anatomical connection). lithic artefact the raw material used of this single lithic artefact (fig. 8) is a very homogeneous good quality flint, probably coming from a local collecting. from a typological point of view, it is a déjeté side-scraper; the blank is a distal fragment of flake. the fracture seems to be contemporaneous to the debitage and the retouch was done directly on the fragmented flake. from the fracture, on the dorsal face, an irregular retouch was done, this one seems to be correlated to the prehension of the tool because it is more evident in correspondence of more prominent arris. the retouch was made by direct percussion with hard hammer and it is direct, continuous, convex, short, semiabrupt and scaled. all those characteristics suggest an attribution of the artefact to the mousterian. discussion the areal and vertical discontinuity of the continental sediments deposited in a karstic cavity, reduce the possibility of finding a correlation between deposits which are relatively close and, a fortiori, between deposits which lie in different regions. a way to partially resolve this problem is to leave the sediments aside and, through biochronology, and by means of the faunal units, to connect the bioevents (considered coeval) of one region. in this perspective, according to gliozzi et al., 1997, during the aurelian age, the most recent mammal age, there are only two faunal units, torre in pietra and vitinia. a series of reasons persuaded these authors not to consider further faunal units valid from the italian peninsula coming from the last one hundred thousand years, when temperatures began to decrease (reaching the minimum in the early last glacial), and especially in the late last glacial (stage 2 o.i.s.). the most important among these reasons (gliozzi et al., 1997) was the fact that, due to the differentiation of the micro-climates, none of the faunal units from this time could be considered as a representative of the biosystems which were present in all the area. however, according to petronio et al., 2007, a detailed and analytical study of the faunal appearance and disappearance during the late pleistocene, may help us to surpass this opinion and to understand whether particular environmental circumstances were really present in the last glacial, or if, on the other hand, considering the increasing closeness of the events, we have to take a different methodological approach. in fact, we must remember that as we near the latter part of the pleistocene, apart from the open fig. 6 bos primigenius: 1, mandibula; 2, metacarpus; 3, metatarsus. dama dama dama: 4, lower molar. cervus elaphus elaphus: 5, lower molar. bos primigenius: 1, mandibola; 2, metacarpo; 3, metatarso. dama dama dama: 4, molare inferiore. cervus elaphus elaphus: 5, molare inferiore. 416 c. petronio et al. cast deposits such as the ossiferous breccias and the filling of the karstic cavities (i.e. deposit from avetrana), also the cavern deposits begin to be more numerous (both along the coastlines, and in the internal areas of the peninsula). these caverns were also inhabited by ancient human beings. the abundance of this data allows us to collect more information than in the middle and early pleistocene. consequently, the late pleistocene, which approximately corresponds to the latter part of the aurelian age, may be divided into two parts: the most ancient includes the last interglacial and the early phase of the last glacial period (between ca. 128.000 and 75.000 years ), and the second part, spanning the later part of the last glacial period between 75.000 and 11.600 years. the climate interval of the most ancient part is very warm (stage 5e o.i.s.). a temperate-hot period follows this, alternating with an oceanic climate (5d) which is more rigid and arid (5c) and a greater forest expansion (5b, 5a) with extremely various essences, as we deduced from the pollinic sequences of “valle del castiglione” (follieri et al., 1989), of “lagaccione” in the vulsini mountains, and of the vico lake. through the relative abundance of mammal remains, deriving from the early late pleistocene (stage 5e o.i.s.), we realize that in this period the environments are more similar to our environment today; and in the meantime, we can note an increasing climatic and environmental, regionalism. due to this phenomenon of micro-zones of climates and bioenvironments, and through the discovery of the micro-mammiferous and macro-faunal remains, we can recognize in northern italy several different ambits, the padano plain, the piedmont plain, the montane plain, and finally the ligurian and the adriatic versant. regarding peninsular italy, the apennines separate the tyrrhenian environment, with a more temperate-humid-hot climate, from the adriatic environment, which is characterized by a continental-arid-fresh climate. there are still many taxa belonging to the previous faunal units, among the mammal fauna from this period which was discovered in the whole peninsula. we have to recall, among the pachyderms, elephas antiquus, mammuthus chosaricus, stephanorhinus hemitoechus and the increasingly always more rare remains of hippopotamus amphibius, which gradually had replaced h. antiquus since the late of the galerian age. capra ibex, rupicapra rupicapra, marmota marmota, along with several felidae and a wolf of large dimension, are very frequent in this period, as well as in the following periods. they obviously were present only in congenial environment, but probably appeared during stage 6 of the palaeotemperatures. remains of bos primigenius and equus ferus were also frequent, while we found fewer remains of equus hydruntinus. for example, evidence of the climatic regionalization, which separates the po region from the rest of the peninsula and from southern italy, is found in the conspicuous remains of red deer, roe deer, bos primigenius, ursus spelaeus, felis silvestris, lynx lynx and, only fig. 7 bos primigenius: cranial remains in the karstic cavity. bos primigenius: resti craniali nella cavità carsica. fig. 8 artefact lithic musterian. manufatto litico musteriano 417the deposit of the late pleistocene ... in north-eastern italy, steppe micro-mammals, such as microtus (stenocranius) gregalis, microtus (palasiinus) oeconomus and ochotona pusilla (kotsakis et al., 2003). capra ibex, rupicapra rupicapra, equus ferus and equus hydruntinus become more frequent when the climatic conditions turn out to be colder and less humid. the climatic regionalization is evidenced also by the early, gradual disappearance (in northern italy, except for liguria – balzi rossi) of the temperate-hot faunal component, which is essentially composed by hippopotamus amphibius, elephas antiquus and stephanorhinus hemitoechus. however the cervidae, among the artiodactyla, present some novelties. red deer, which was common in all the italian territories in the early and middle aurelian age (f. u. torre in pietra and vitinia; gliozzi et al., 1997) with local archaic subspecies (cervus elaphus rianensis, cervus elaphus aretinus), is attested by its modern subspecies of cervus elaphus elaphus. the modern fallow deer (dama dama dama), which has multiplied since stage 5 o.i.s, especially in the more temperate regions of the peninsula, descended from dama dama tiberina (di stefano & petronio, 1998), a form of archaic mediterranean fallow deer which multiplied in europe during stage 8 and 7 o.i.s. as demonstrated by petronio et al., 2007, it is possible to correlate the fossiliferous deposit of cava nuzzo (in the melpignano area, near maglie lecce, in the southern salento area (bologna et al., 1994; di stefano, phd thesis, 1985) with stage 5 b-a/4, where both the modern cervines are indicated, even though dama dama dama is mostly present. the faunal data evidence an extensive arboreal cover, alternated with arid and hot open areas, which are populated by a dominant species, terricola savii, and by the wild rabbit (oryctolagus cuniculus). in this deposit, near the st. sidero area (de giuli, 1983), apart from the two cervines, a rich mammal fauna was found, contained inside the karstic “ventarole” present in the stones of lecce. along with the remains of pachyderms, (elephas antiquus, stephanorhinus hemitoechus) there are several specimens of crocuta crocuta (whose morphological features are very similar to that of crocuta crocuta intermedia), a form of large dimension of equus ferus, equus hydruntinus, bos primigenius of large dimension, remains of bison priscus, and a rich micro-mammal fauna. the presence of modern cervids, along with this mammal fauna, in the same deposit, allowed the authors (petronio et al., 2007) to establish the new faunal unit of melpignano, and consequently to determine a possible temporal interval which is included between 110.000 and 80.000 years for this unit. also the first reports in italy of the wholly rhino (coelodonta antiquitatis ) and of the mammoth (mammuthus primigenius) (gliozzi et al., 1997) demonstrate the passage from this chronological interval to the gradual climatic recrudescence, which includes the entire italian peninsula and which characterizes stage 4 o.i.s.. however, apart from these species deriving from north-eastern and north-central europe, also some stenoterm taxa proliferate, or taxa that prefer steppe environments, with temperate-cold climates. the fragmentation of the different faunal assemblages present in the various italian regions, does not impede us to note the few biological common events which allow us to define a last temporal interval, faunal unit of ingarano, between 70.000 and 35.000 years bp (petronio et al., 2007) from a biochronological point of view. this interval is characterized by the first evidences of coelodonta antiquitatis, mammuthus primigenius, and marmota primigenia, in italy. in the deposit of ingarano (petronio & sardella, 1998) coelodonta antiquitatis is associated with an extremely rich mammal fauna. in this chaotic grotto deposit, it is possible to distinguish at least two levels. the external level is the most ancient. here we found, apart from the remains of coelodonta, some remains of stephanorhinus hemitoechus, hippopotamus amphibius, elephas antiquus, vulpes vulpes, cervus elaphus elaphus, and of equus hydruntinus. the second level was the actual deposit of the grotto, here we found, in addition to a notable abundance of large, medium and small size carnivores, a faunal assemblage (petronio & sardella, 1998) evidencing a gradual climatic recrudescence (nyctea scandiaca, gulo gulo, rupicapra rupicapra, etc...). therefore, this is the palaeobiological context of the early late pleistocene. the faunal assemblage found in the site of avetrana, in the opinion of the authors, must be collocated in this period. the biochronologic detailed distribution of the different taxa allows us to draw some conclusions. 1. the presence of hystrix vinogradovi in the faunal assemblage, as already mentioned, represents a first significant element for the biochronological collocation due to the fact that (kotsakis et al., 2003) this rodent becomes extremely rare during the late pleistocene. the evidence of its remains is considered extremely dubious, mainly if it is deduced from the dimensional elements, instead of from the morphology of its molars. in fact, there is some evidence of porcupines in the late pleistocene, but they are the remains of a discussed stratigraphic position (bartolomei, 1969; kotsakis et al., 2003). therefore, the remains of h. vinogradovi found among the faunal remains in the site of avetrana are, at the present time, the most recent discovery in italy, and the discovery in the most southern part of europe. 2. also the report of the remains of hippopotamus becomes even more rare during the late pleistocene, limiting the late chronological interval that we must consider for the faunal assemblage of avetrana. in fact, as already mentioned, among the remains of the entrance to the cave of ingarano (petronio & sardella, 1998), along with the remains of coelodonta antiquitatis, the last appearance of hippopotamus amphibius is cited. the latter, according to our knowledge today of the first manifestation of the whooly rhinoceros, allows us to link the fossiliferous sediments of ingarano with stage 4 of the palaeotemperatures, or near this stage. 3. the dental structures of the remains of dama dama dama represent a morphological element which limits the inferior chronological interval of the faunal assemblage from avetrana. this element indicates a temporal interval which is posterior to the middlelate pleistocene. as already mentioned, the molarized premolars, and the cingula which are clearly evident, allow us to lean toward the first archaic forms 418 c. petronio et al. of the modern fallow deer. also the modernness of the structure of the fragments of the antlers of cervus elaphus, cause us to exclude elaphine forms from the middle pleistocene. 4. we find in literature that the height of some species decreased from the middle-late pleistocene, to the late holocene. this happened, for example, to capra ibex (bartolomei & sala, 1972), vulpes vulpes (petronio et al., 2006), equus ferus (eisenmann & david, 2002; conti et al., in press) and to bos primigenius (grigson, 1969; cerilli & petronio, 1998). the morphological structures, and in particular the dimension of bos primigenius found in avetrana, seem to lead us to believe their biochronological placement is in the early late pleistocene. in fact, if we consider the publications of degerbøl & fredskild (1970), brugal (1983), grigson (1969) and cerilli & petronio (1998), concerning the evolutive degree of the different populations of bos primigenius deriving from the european pleistocene, we can identify a particular evolutive trend. during this trend, the height and stoutness, in particular of the limbs, constantly decreased. however, even though we had a large quantity of measurements of tibiae, humeri, radii, femurs, and especially of phalanxes and small bones (i.e. carpi and tarsi), it was not possible to obtain useful indications since we did not have statistical significant samples. we considered in particular the metapodial bones as they are numerous and because of their particular morphofunctional importance, as well. however, in general all of the bones of bos primigenius have decreased dimensions. in fact, from the statistical analysis carried out on the metacarpi and metatarsi of bos primigenius (fig. 9), a noticeable lowering of its dimension seems to be evident, since the late pleistocene. this trend allowed us to identify a common area between the values of the population from avetrana and the values referable to the populations from the early late pleistocene. the scattering charts and the general charts give us some consistent information. in the scattering diagram we associate the values of the transversal distal diameters with the max. length (fig. 9 a). in the general chart we consider the variations of the max. length from the middle-late pleistocene, to the holocene. in the diagram concerning the metacarpi, we can clearly note two areas. the first one is typical of the holocene populations. this area is mostly concentrated in the left lower part of the graph and clearly shows us that these populations had a reduced height and that they were not very robust. the second area, which refers to the populations from the middle-late pleistocene to the late pleistocene, is mostly concentrated in the central and right side of the graph. this area obviously indicates larger fig. 9 bos primigenius: a) scattergram of max length and transversal distal diameter in metacarpus; b) variations of the max. length in metatarsus from the middle-late pleistocene, to the holocene. bos primigenius: a) distribuzione della lunghezza massima e del diametro distale trasverso nei metacarpi; b) variazione della massima lunghezza nel metatarso dal pleistocene medio superiore all’olocene. 419the deposit of the late pleistocene ... dimensions and more robust bones. the avetrana population approximately corresponds to the latter area, even if the subjects of larger dimensions, probably males, are more slim. in the diagram concerning the metatarsi (fig. 9 b), the data of the minimum, medium and maximum values of the maximum length indicate that since the early late pleistocene the aurochses dimensions gradually and clearly decreased. the data of the avetrana assemblage show a strict analogy to the values which characterize the populations from the early late pleistocene, both in the scattering chart (fig.8 b), and in the graph regarding length (fig. 9 b). conclusion from the biochronological analysis of the mammal fauna from avetrana (fig. 10), we can detect some data which allow us to exclude a chronological interval which expands over the early late pleistocene, due to the presence of hystrix vinogradovi and hippopotamus amphibius. on the other hand, the presence of archaic forms of dama dama dama and cervus elaphus elaphus shows (petronio et al., 2007) an age which expands from the first part of late pleistocene to the initial phases of stage 4 o.i.s.. however, also the presence as well of a quite archaic mousterian manufacture is not in contrast with this faunal assemblage, even if it isn’t sufficient to define a chronological interval. finally, this interval of time can be confirmed, as already shown, by the dimension, in particular of the limbs, of bos primigenius. taking these factors into consideration, the authors assume that the mammal fauna from avetrana can be attributed to the f.u. of melpignano (petronio et al., 2007). regarding the genesis of the deposit, the observations made on the structure of the cavity, on the sediments of the filling, the physical status and spatial disposition of the fossil bones suggest that the stratification originated from a series of depositional events, which were independent and exceptional. the fossil bones are usually well preserved, with the exception of those of layer 9. no clear evidences of human activity and of gnawing by rodents and carnivores have been checked, several bones are fractured. different part of the skeleton of the ungulates are not equally distributed. these data suggest the main role of sinand postdepositional physical and chemical factors. water has been the principle, if not the only one, depositional factor. moreover, many bones are complete, some of them articulated, without clear signs of transport. thus, carcasses (in particular those of bos primigenius) were not carried by water for long distances, their disposition being quite chaotic in the deposit. some intentional fractures can be noticed only on a hippo humerus. that, together with the collection of a single mousterian fig. 10 biochronology of late pleistocene. biocronologia del pleistocene superiore. 420 c. petronio et al. tool, suggest a human frequentation of the area, but without an active role in the deposition. the lower part of the karstic cavity, including the little fissures of level 0, was only filled by debris and by small bones, because it was the only material which could pass through the small karstic microfissures. the actual levels of the main cavity (levels 1-9), underwent a slight modification and remixing on the top. moreover, due to the lack of evident surfaces of erosion and of palaeosoils, we can not determine any periods of outcrop and exposure. the run-off water and the flood-water, probably due to conspicuous showers or to the overflow of adjacent streams, caused the detrital sediments, the clastoi of various dimensions, and the bones of the vertebrates which the water found along its way, to be carried inside the karstic fissure. the hypothesis that the fossiliferous deposit was the result of a series of individual events, which occurred close to each other, is corroborated and confirmed by the presence of this faunal assemblage which is coherent from a chronological point of view. the assemblage remains practically unaltered in its general features, aside from the different levels. this is possible only when the time passed from the first and the last event is insignificant from a geological point of view. some general considerations on the palaeoenvironmental conditions of the area derive in particular from the presence at level 0 of terricola savii, and of the lagomorphs, which indicate the presence of a temperate environment characterized by large ample spaces. this aspect is also confirmed by the avifauna. in fact, the fossil remains of birds found in avetrana, even if belonging to a few species, provide us with homogeneous indications from an ecological point of view, allowing us to retrace the avetrana habitat during the phases of the formation of the fossiliferous deposit. all the species found are linked to an open environment with the presence of rocky outcrops on which it is possible to nidificate. this is mostly suggested by the discovery in the deposit of athene noctua, columba livia, pyrrhocorax graculus, and p. pyrrhocorax. the open areas were inhabited by other species (i.e. otis tarda and perdix perdix). the remains of large and medium dimension are mostly present in the fossil assemblage. we can consequently assume that it was not a predator that caused the deposition of these remains. this detail coincides with the fact that we mostly found remains of cock-ofthe-rock species, while the species which are typical of open environments are sporadic, and were carried inside the deposit along with countless mammal remains. regarding the faunal assemblage of the large mammals, we can gather general information concerning an environment characterized by an open forest, or by a grassland-park, variously wooded. the great quantity of aurochs, and the presence of deer and fallow deer emphasize an environment characterized by large wooded areas, that are rich in glades, with both ample and open spaces where, presumably, the rhinoceros and the most part of the carnivorous forms (found in the faunal assemblage) lived. the wild pig and hippopotamus were also present, even though they were not copious, suggesting the presence of expanses of water and of an area which was more humid than the actual one. references bartolomei g. (1969) considerazioni ecologiche sulle faune pleistoceniche dell’europa contenenti scimmie ed istrici. in scritti sul quaternario in onore di angelo pasa, pp. 39-52, verona. bartolomei g. & sala b. (1972) nuovi dati paleontologici e paleoecologici sugli stambecchi cacciati dagli uomini preistorici di alcuni giacimenti italiani dell'ultimo glaciale e del primo postglaciale. una vita per la natura, wwf, pp. 101-120, camerino. billia e. & petronio c. (2007) selected records of stephanorhinus kirchbergensis (jäger, 1839) (mammalia, rhinocerotidae) in italy. bollettino società paleontologica italiana, in press. bologna p., di stefano g., manzi g., petronio c., sardella, r. squazzini e. (1994) late pleistocene mammals from the melpignano (le) "ventarole": preliminary analysis and correlations. bollettino società paleontologica italiana, 33 (2), pp. 265274, modena. brugal j.p. (1983) applications des analyses multidimensionelles a l’etude du squelette des membres des grandes bovides pleistocenes (grottes de lunel-viel, herault); perspectives evolutives. these de doctorat 3ème cycle, universite aixmarseille ii, faculte des sciences de luminy, marseille. cerilli e. & petronio c. (1992) biometrical variations of bos primigenius bojanus, 1827 from pleistocene to holocene. “ongules/ungulates 91” proced. intern. symp., pp.37-42, toulouse. ciaranfi n., maggiore m., pieri p., rapisardi l., ricchetti g. & walsh n. (1979) considerazioni sulla neotettonica della fossa bradanica. in: nuovi contributi alla realizzazione della carta neotettonica d’italia, c.n.r. prog. finaliz. geodinamica, pubbl. 251, pp.73-96, napoli. conti n., coppola d., petronio c., petrucci m., salari l. & sardella (2008) la fauna del pleistocene superiore di tana delle iene (ceglie messapica, br). bollettino società paleontologica italiana, in press, modena. degerbøl m. fredskild b. (1970) the urus (bos primigenius bojanus) and neolitic domesticated cattle (bos taurus domesticus linnè) in denmark, with a revision of bos-remains from the kitchen middens. zoological and palynological investigations. biologiske skrifter, 17(1), 234 pp., københavn. de giuli c. (1983) le faune pleistoceniche del salento: 1. la fauna di s. sidero 3. quaderni del museo comunale di paleontologia, 1, pp. 45-84, maglie. di stefano g. (1995) i l daino pleistocenico dell’eurasia. phd thesis, università di modena, bologna, firenze, roma “la sapienza”. di stefano g. & petronio c. (1998) origin and evolution of the european fal low deer (dama, pleistocene). n.jb. geol. palaont. abh., 203 (1), pp. 57-75, stuttgart. eisenmann v. & david f. (2002) évolution de la taille des chevaux d'arcy-sur-cure et de quelques autres chevaux quaternaires. gallia préhistoire, xxxiv supp., pp. 97-102. follieri m., magri d. & sadori l. (1989) pollen stratigraphical symthesis from valle di castiglione 421the deposit of the late pleistocene ... (roma). quaternary international, 3/4, pp. 81-84. gliozzi e., abbazzi l., ambrosetti p.g., argenti p., azzaroli a., caloi l., capasso barbato l., di stefano g., ficcarelli g., kotsakis t., masini f., mazza p., mezzabotta c., palombo m.r., petronio c., rook l., sala b., sardella r., zanalda e. & torre d. (1997) biochronology of selected mammals, molluscs and ostracods from the middle pliocene to the late pleistocene in italy. the state of the art. rivista italiana di paleontologia e stratigrafia, 103 (3), pp. 369-388, milano. grigson c. (1969) the uses and limitations of differences in absolute size in the distinction between the bones of aurochs (bos primigenius) and domestic cattle (bos taurus). in ucko p.j. & dimbleby g.w. (eds), the domestication and exploitation of plants and animals, pp. 277-294, duckworth & co., london. guerin c. (1980) les rhinocéros (mammalia, perissodactyla) du miocène terminal au pléistocène supérieur en europe occidentale. comparaison avec les espèces actuelles. documents du laboratoire de géologie de lyon, 79 (1-3), pp.1-1185, lyon. iacoangeli o. (1996) i lagomorfi pleistocenici di melpignano (le), tesi sperimentale inedita in paleontologia dei vertebrati, università “la sapienza” di roma. jànossy d. (1972) ein kleiner hystrix aus dem altpleistozän der fundstelle osztramos 8 (nordungarn). vertebrata ungarica, 13, pp. 163182. kolfschoten t. van (2000) the eemian mammal fauna of central europe . netherlands journal of geosciences, 79, pp. 269-281. kosintsev p. (2007) late pleistocene large mammals faunas from the urals. quaternary international, 160, pp. 112-120. kotsakis t., abbazzi l., angelone c., argenti p., barisone g., fanfani f., marcolini f. and masini f. (2003) plio-pleistocene biogeography of italian mainland micromammals. deinsea, 10, pp. 313-342. lacombat f. (2005) les rhinocéros fossiles des sites préhistoriques de l’europe méditerranéenne et du massif central. paléontologie et implications biochronologiques. bar international series 1419, pp. 1–175. louchart a., bedetti c. & pavia m. (2005) new species of eagle (aves: accipitridae) close to the steppe eagle from pleistocene of corsica and sardinia. palaeontographica, abt. a, 272, pp. 121-148, stuttgart. made j. van der, aguirre e., bastir m., fernandez jalvo y., huguet r., laplana c., marquez b., martinez c., matinon m., rosas a., rodriguez j., sàanchez a., sarmiento s. & bermùdez de castro j.m. (2003) el registro paleontològico y arqueològico de los yacimientos de la trinchera del ferrocarril en la sierra de atapuerca . coloquios de paleontologia, v.e., 1, pp. 345-372. miller g. s. (1912) catalogue of the mammals of western europe in the collection of the british museum. british museum (natural history), 1019 pp., london. ognev s. i. (1935) mammals of ussr and adjacent countries. iii. moskow-leningrad. pavia m. & mourer-cauviré c. (2002) an overwiew of the genus athene in the pleistocene of the mediterranean islands, with the description of athene trinacriae n. sp. (aves: strigidae). in: zhou and zhang (eds.): proceedings of the 5th symposium of the society of avian paleontology and evolution. beijing science press, pp. 13-27, beijing. petronio c., anzidei a.p., bedetti c., bona f., di canzio e., gentili s., mazza p., palombo m.r., pavia m., salari l., sardella r. & tintori a. (2005), le faune a mammiferi del plio-pleistocene. in l. bonfiglio (ed.) paleontologia dei vertebrati in italia. memorie museo civico storia naturale di verona, ii s., scienze della terra, 6, pp. 183-218, verona. petronio c., di canzio e. & salari l. (2007) the late pleistocene and holocene mammals in italy : new biochronological and paleoenvironmental data. palaeontographica, abt. a, 279, pp. 147-157, stuttgart. petronio c., petrucci m. & salari l. (2006) la volpe nel pleistocene superiore italiano: indicazioni paleoambientali. bollettino museo civico storia naturale di verona, 30, pp. 59-78, verona. petronio c. & sardella r. (1998) remarks on the stratigraphy and biochronology of the la pleistocene deposit of ingarano (apulia, southern italy). rivista italiana paleontologia e stratigrafia, 104, pp. 287294, milano. sardella r., bedetti c., bellucci l., conti n., coppola d., di canzio e., pavia m., petronio c., petrucci m. & salari l. (2005) the late pleistocene vertebrate fauna from avetrana (taranto, abulia, southern italy): preliminary report. geo. alp, 2, pp. 25-29. schweitzer m. (2002) grotte de la chênelaz (hostias, ain, france): les grands mammifères de la couche 6b. revue de paléobiologie, 21, pp. 803-818. tomek t. & bocheński z.m. (2000) the comparative osteology of european corvids (aves: corvidae), with a key to the identification of their skeletal elements. v. of 102 pp. instytut systematyki i ewolucji zwierat polskiej akademii nauk, kraków. trocchi v. & riga f. (2002), lepre italica, lepus corsicanus de winton 1898.. in: m. spagnesi, a.m. de marinis (a cura di), mammiferi d’italia. quaderni di conservazione della natura, 14. min. ambiente ist. naz. fauna selvatica: 149-151. weers d.j. van (2005) a taxonomic revision of the pleistocene hystrix (hystricidae, rodentia) from eurasia with notes on the evolution of the family. contributions to zoology, 74, pp. 301-312. ms. ricevuto il 19 marzo 2008 testo definitivo ricevuto il 23 ottobre 2008 ms. received: march 19, 2008 final text received: october 23, 2008 422 c. petronio et al. << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /none /binding /left /calgrayprofile (dot gain 20%) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /error /compatibilitylevel 1.4 /compressobjects /tags /compresspages true /convertimagestoindexed true /passthroughjpegimages true 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(quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), i ii in memory of carlo bosi carlo bartolini dipartimento di scienze della terra, università di firenze, firenze, italy carlo, an orphan of his father who died at war in ethiopia, had initially trained in rimini, where he lived together with his family. the atmosphere of the dolce vita did not influence him at all. on the contrary, the dominant feature of carlo's character was the strong sense of responsibility, perhaps also due to the emotional shortcomings deeprooted in the status of an orphan. added to this was his solid. moreover, his long lasting, passionate research on the sense of truth reveals the close relationship that carlo had with his conscience. as cnr researcher, he initially joined the study center for technical geology. his hunger for knowledge (he described himself as "greedy") soon turned his interests into quaternary geology and, almost inevitably, towards the recent tectonics. this phase coincided with his frequentation of the pioneering “study group on the quaternary padano”, while he completed the geological survey of the quaternary of the aterno valley with his friend tullio bertini. between the end of the '70s and the half of the following decade, all his professional commitment was absorbed first by the preparatory studies and then by the drafting of the italian neotectonic map at a scale of 1:500.00. thus, a new discipline was born in our country, of which carlo was the main promoter. in order to cover the entire territory of italy, the project was divided into multiple operating units that were headed by regional coordinators, always in close contact with carlo. before the publication of the map, a myriad of publications related to specific fields of study saw the light, all structured according to a strict pattern, so that data and interpretations could then easily be used in the final product. for carlo it was a coordination work that highlighted his superior leadership skills, an enterprise of extraordinary proportions. his self-irony helped him overcome frictions and misunderstandings. once published, the map made more than one eyebrow raise and rightly, because it was the result of a very ambitious project, based on less than ten years of study in a totally new field. the road, however, was open: since the beginning of the 80s, recent tectonic studies have multiplied and soon they have interfaced, on a national level, with seismological knowledge. from this combination, seismic microzonation was born, which in recent times has been used as an essential parameter of the legislation related to the type of construction. after the great commitment mentioned above, carlo returned to his long-standing passion for the sea and bought the kalinka, a small sailboat, with which he sailed for some years in the tuscan archipelago; the routes were mostly planned to spend the end the day of navigation in a good restaurant along the coast! the nautical activity that fascinated him so much was put to an end when he was diagnosed a heart disease in 1990. he passed the passion for the sea on to his children, vittorio and sania. he calmly accepted his progressively discarlo bosi 1 september 1935 1 marz 2018 https://doi.org/10.26382/aiqua.2018.aiquaconference abling condition, without ever blatantly complaining. in this the warm and relentless assistance of rita was of immense help. after 1990, he was able to pay more attention to his many other interests: reading, not as an end in itself and always committed, listening to music, traveling to little known or hidden places, the taste for the table. he also had more time to read and write only for his children and friends about philosophy and sociology, a passion that absorbed him a great deal and that certainly was his teacher in dialectic, the daily instrument of his activity as coordinator of the neotectonic map of italy and during his activities as aiqua president (19941996 and 2004-2006). carlo bartolini ii bartolini c. 1 as a young man …. 2 on the field ….. 3 madrid 1980 4 kalinka 1985 5 using the field stereoscope 1 2 3 4 5 base evoluzione geologica del settore settentrionale del tavoliere di puglia (italia meridionale) nel pleistocene medio e superiore massimo moretti, salvatore gallicchio, luigi spalluto, neri ciaranfi & piero pieri. dipartimento di geologia e geofisica università degli studi, bari corresponding author: s. gallicchio <s.gallicchio@geo.uniba.it> riassunto: moretti m. et al., evoluzione geologica del settore settentrionale del tavoliere di puglia (italia meridionale) nel pleistocene medio e superiore. (it issn 0394-3356, 2010). vengono presentati i risultati emersi essenzialmente dal rilevamento delle aree di due fogli (f°407 “s. bartolomeo in galdo” e f°396 “s. severo”) della nuova carta geologica d’italia (1:50.000) nelle quali è compreso il settore settentrionale del tavoliere di puglia, che geograficamente è posto fra l’appennino dauno ad ovest, e il promontorio del gargano ad est. sotto il profilo geologico, il tavoliere corrisponde al settore nord-occidentale della fossa bradanica ed è caratterizzato da estesi affioramenti di depositi del quaternario. viene qui illustrato il complesso dei depositi marini e continentali del pleistocene medio e superiore. il quadro stratigrafico proposto è sostanzialmente nuovo e diverso rispetto a quanto noto in letteratura, sia sulla base dei dati desumibili dalla cartografia ufficiale dei fogli 1:100.000 che da lavori più recenti; in questi depositi sono state distinte 7 unità stratigrafiche a limiti inconformi (sintemi), parte delle quali costituita da subsintemi sia marini che continentali; nell’insieme, tali unità sintemiche sono state raggruppate in una unità di rango superiore denominata supersintema del tavoliere di puglia. sia le unità marine che quelle continentali, in entrambi i casi si tratta di depositi terrazzati, costituiscono sottili coperture disconformi sul substrato siltoso-argilloso rappresentato generalmente dall’unità delle argille subappennine localmente riferita al pliocene superiore-pleistocene inferiore. i subsintemi costituiti da depositi marini, che affiorano solo nel settore orientale dell’area investigata nelle aree di san severo e di apricena, sono rappresentati da facies di transizione soprattutto delta e spiagge e da facies marine di mare sottile in ambienti di baia protetta. i sintemi ed i subsintemi con facies continentali affiorano, dal più antico al più recente, a quote variabili fra i 500 m s.l.m. del settore pedemontano del tavoliere fino ai 2030 m s.l.m. nelle porzioni più orientali dell’area; corrispondono nel settore pedemontano ad ambienti di conoide da prossimale a distale, che, verso est, passano a depositi di piana braided e di piana alluvionale via via di minore energia e che, nella parte orientale dell’area considerata, sono costituiti anche da depositi di palude e laguna costiera. l'insieme dei dati raccolti mostra che i depositi quaternari del settore settentrionale del tavoliere di puglia costituiscono un complesso insieme di depositi marini e continentali che rappresentano il prodotto dell’interazione fra il sollevamento regionale che ha caratterizzato l’intera fossa bradanica dalla fine del pleistocene inferiore e le variazioni eustatiche del livello marino. il lavoro infine propone uno schema di evoluzione paleogeografica per l’intero settore settentrionale del tavoliere di puglia nel pleistocene medio e superiore. abstract: moretti m. et al., evoluzione geologica del settore settentrionale del tavoliere di puglia (italia meridionale) nel pleistocene medio e superiore. (it issn 0394-3356, 2010). the tavoliere di puglia is the third largest plain in italy (surface area is about 3.500 km2) and is located between the southern appenninic chain (subappenino dauno) and the apulian foreland (gargano promontory). from a geological point of view, the tavoliere di puglia plain represents the northern sector of the southern appenninic plio-pleistocene foredeep known as bradanic trough. in the lower pleistocene, the area was subjected to a phase of subsidence (with a rate in the order of 1 mm/y), while, from middle pleistocene to present-day, a moderate uplift phase occurred. data field from the survey for the new geological map of italy (c.a.r.g. project) and analyses carried out on well logs allowed the detailed study of the latest phases of sedimentation during the regional uplift of the northern sector of the bradanic trough. the geological survey was carried out in an area (408 “san bartolomeo” and 396 “san severo” sheets of the new geological map of italy 1:50.000 scale) that covers the entire plio-pleistocene foredeep extending from the external thrust sheets of the subappennino dauno to the western gargano highs. this paper presents only the data collected during the survey of the middle upper pleistocene deposits: they are marine, transitional and continental deposits and are clearly terraced at different elevations above present sea level. they lie on unconformity surfaces above older units represented mainly by miocene apenninic units in the western sectors, plio-pleistocene argille subappenine unit in the foredeep area and carbonatic mesozoic-cenozoic units in the western gargano area. the recognition of unconformity surfaces of great lateral extent allowed us to distinguish 7 different synthems grouped in the tavoliere di puglia supersynthem. some synthems contain a lower marine and/or transitional subsynthem and an upper alluvial subsynthem separated by an unconformity surface. marine and transitional subsynthems crop out in the eastern part of the study area (close to san severo and apricena area) and are represented mainly by coarsening-upward successions deposited in deltaic, proximal marine and low-energy protected embayment settings. in the western and higher sectors, alluvial subsynthems occur; they contain coarsening-upward successions of (proximal to distal) alluvial fan environments passing eastward to braided and coastal alluvial plain environments. lateral facies changes can be followed gradually from areas next to the chain toward the eastern foreland areas. facies changes can be observed also comparing synthems of different ages: for example, alluvial facies observed at the same distance from the chain are coarser-grained in the older synthems and finer-grained in the younger ones; the basal unconformity of different alluvial synthems show similar features: it is very inclined to the east in older synthems and becomes gradually less steep for the younger ones. our data show that the tavoliere di puglia supersynthem represents a complex assemblage of marine and alluvial terraced deposits that records the interaction between regional uplift and sea-level changes. we propose a new set of detailed paleogeographic evolutionary stages for the northern sector of the bradanic trough during middle and upper pleistocene. in addition, these data allow us to compare the tavoliere di puglia plain and southern bradanic trough evolutions. parole chiave: depositi alluvionali, di transizione e marini terrazzati; fossa bradanica; pleistocene medio-superiore; tavoliere di puglia; italia meridionale. keywords: alluvial, transitional and marine terraced deposit; early-late pleistocene; bradanic trough; tavoliere di puglia; southern italy. il quaternario italian journal of quaternary sciences 23(2), 2010 181-198 182 moretti et al. 1. introduzione il tavoliere di puglia (fig. 1) rappresenta un’estesa pianura alluvionale che, con i suoi 3500 kmq d’estensione areale, è la terza d'italia dopo le pianure padana e veneta; questa regione è limitata a n dalla valle del fortore e a s da quella dell’ofanto (fig. 1.c) ed è solcata da numerosi corsi d'acqua a carattere torrentizio che, a dispetto del loro limitato bacino imbrifero, hanno prodotto e producono estese esondazioni che, quasi annualmente, danneggiano in modo rilevante sia l’agricoltura che la viabilità. dal punto di vista morfologico, il tavoliere è caratterizzato da strette ed allungate colline a tetto piatto cui si interpongono larghe valli solcate da numerosi corsi d’acqua (t. cervaro, t. carapelle, t. vulgano, t. salsola, t. cacciafumo, canale di mottamontecorvino, t. triolo – fig. 1.c) che scorrono da o verso e, con tracciati paralleli fra loro. anche la forma dei bacini imbriferi è stretta ed allungata, con linee di spartiacque anch’esse subparallele, isorientate rispetto agli assi dei corsi d’acqua. gli spartiacque nelle porzioni più orientali delle valli risultano poco definiti tanto che, in occasione di eventi di piena, i corsi d'acqua principali esondano l’intera piana alluvionale. dal punto di vista geologico, il tavoliere di puglia rappresenta il settore settentrionale della fossa bradanica, limitato ad o dal subappennino dauno e ad e dal promontorio del gargano (figg. 1.a e b). la fossa bradanica è caratterizzata nel corso del pliocene e del quaternario da due distinte fasi evolutive: 1) una marcata subsidenza – stimata attorno a 1 mm/anno nel pliocene e nel pleistocene inferiore connessa alla subsidenza del margine interno della piattaforma apula e 2) un sollevamento, valutato in circa 0.3-0,5 mm/anno, che comincia alla fine del pleistocene inferiore e si esplica nel pleistocene mediosuperiore). quest’ultimo fenomeno geodinamico è stato interpretato in due differenti modi in letteratura: come aggiustamento isostatico postorogenico (ricchetti et al., 1988), oppure come buckling dell’avampaese per resistenza alla subduzione (doglioni et al., 1994). dal punto di vista regionale, la subsidenza plio-pleistocenica è segnata dalla sedimentazione della formazione della calcarenite di gravina che passa verso l’alto e fig. 1 a. localizzazione del sistema catena-avanfossa-avampaese dell’appennino meridionale. b. carta geologica schematica del sistema catena-avanfossa-avampaese dell’appennino meridionale e localizzazione del tavoliere di puglia: esso rappresenta il settore settentrionale della fossa bradanica. c. il tavoliere di puglia è limitato a nord dalla valle del fiume fortore e a sud da quella dell’ofanto. d. schema di localizzazione dei fogli della carta geologica d’italia alla scala 1:100.000 che ricoprono il tavoliere di puglia; in grigio il settore di tavoliere analizzato in questo lavoro. a. location of the chain-foredeep-foreland system of the southern apennines. b. schematic geologic map of the chain-foredeep-foreland system of the southern apennines and location of the tavoliere di puglia plain: note that it represents the northern sector of the bradanic trough. c. the tavoliere di puglia plain is limited, toward north, by the fortore valley and, toward south, by the ofanto valley. d. location of the official sheets of the geological map of italy (at 1:100.000 scale) in the tavoliere di puglia plain; note in grey, the part of the tavoliere di puglia analysed in this paper. lateralmente ad una spessa successione siltoso-argilloso-sabbiosa (argille subappennine); il sollevamento del pleistocene medio e superiore è invece segnato sia da depositi regressivi che da depositi terrazzati (e.g. tropeano et al., 2002). l’area che viene qui analizzata in dettaglio (fig. 1.d e tav. 1) rientra in quella dei fogli 407 “san bartolomeo in galdo” e 396 “san severo” della nuova carta geologica d’italia alla scala 1:50.000 (progetto c.a.r.g.): rappresenta un’estesa porzione del tavoliere di puglia nella quale affiorano tutte le unità stratigrafiche quaternarie che caratterizzano il settore settentrionale della fossa bradanica. i risultati dei lavori di rilevamento e le analisi condotte sulle stratigrafie dei pozzi a carotaggio continuo perforati appositamente per il progetto c.a.r.g. hanno consentito di elaborare un quadro stratigrafico sostanzialmente differente da quello desumibile dai dati di letteratura. in questo lavoro vengono in particolare illustrati i principali caratteri stratigrafici e di facies del complesso dei depositi marini, di transizione e continentali del pleistocene medio e superiore relativi cioè alla sola fase di sollevamento regionale nel settore settentrionale della fossa bradanica. infine va ricordato che nel presente lavoro, in seguito alla ridefinizione del l imite neogene – quaternario (gibbard et al., 2010), il pleistocene inferiore deve intendersi come comprensivo del gelasiano (rio et al., 1998) e del calabriano (cita et al., 2006; cita et al., 2008). 2. studi precedenti la cartografia ufficiale alla scala 1:100.000 dell’area in studio (fig. 1.d) è compresa in quattro differenti fogli (f°155 s. severo boni et al., 1969; f°156 s. marco in lamis – cremonini et al, 1971; f°163 lucera jacobacci et al., 1967; f° 164 foggia merla et al., 1969). il substrato dei depositi del pleistocene medio e superiore è rappresentato dalle argille subappennine (“formazione dell’ofanto” di crostella & vezzani, 1964; argille di montesecco di boni et al., 1969). dati di profondità rinvenienti da studi per ricerche petrolifere e indagini su ampie sezioni stratigrafiche delle argille subappennine affioranti nel tavoliere sono analizzati rispettivamente in balduzzi et al. (1982) e d’alessandro & la perna (2004). sulle argille subappennine, localmente di età compresa fra il piacenziano ed il calabriano, si rinviene un complesso di depositi che viene interpretato in maniera differente nei vari fogli geologici alla scala 1:100.000: boni et al. (1969) e cremonini et al. (1971) riconoscono depositi marini del pleistocene inferiore (sabbie di serra capriola e conglomerati di campo marino) in continuità sulle sottostanti argille plio-pleistoceniche, delineando un quadro stratigrafico simile a quello desumibile per il settore meridionale della fossa bradanica a sud dell’ofanto, cioè il cosiddetto ciclo bradanico con argille subappennine, sabbie di monte marano e conglomerato di irsina (ricchetti, 1965). jacobacci et al. (1967) e merla et al. (1969) interpretano invece gli stessi depositi, indicati con denominazioni differenti ma affioranti in aree lateralmente continue alle precedenti e con identiche quote di affioramento, sostanzialmente come depositi marini terrazzati, riconoscendo quindi la loro natura trasgressiva, al di sopra del 183evoluzione geologica del settore settentrionale ... substrato argilloso plio-pleistocenico. delano smith (1978), ciaranfi & rapisardi (1979), caldara & pennetta (1991; 1993), boenzi et al. (1992) individuano la successione regressiva del ciclo bradanico nel settore pedemontano del tavoliere e, verso est, a partire dall’area di lucera, una serie di depositi marini terrazzati. la sintesi regionale del tavoliere di puglia in bonardi et al. (1988) riprende tale suddivisione fra depositi regressivi della fossa bradanica e depositi marini terrazzati; questi ultimi caratterizzerebbero solo le sommità delle colline con quote inferiore ai 350 m. parea (1986) sostiene, al contrario, che l’area del tavoliere sia coperta prevalentemente da depositi alluvionali che coprono superfici inclinate verso mare; tali superfici proseguirebbero secondo l’autore al di sotto dei sedimenti della piana alluvionale recente-attuale; i relativi depositi marini, cioè le varie paleospiagge, non affiorerebbero perchè sepolte sotto i sedimenti olocenici della piana costiera a causa del mancato sollevamento dell’avampaese garganico durante i l pleistocene. moccia (1993) nella stessa area segnala la presenza di depositi continentali in corrispondenza dei terrazzi più elevati, e di depositi marini per quelli posti a quote inferiori ai 240 m. più recentemente, capuano et al. (1996) e aucelli et al. (1997), nei loro lavori nei dintorni di torremaggiore riutilizzano le denominazioni formazionali di boni et al. (1969) attribuendo di fatto i depositi quaternari analizzati alla successione regressiva bradanica. infine gallicchio et al. (2002) riconoscono unicamente depositi continentali terrazzati del pleistocene medio e superiore nel settore occidentale e pedemontano del tavoliere e spalluto & moretti (2006) segnalano la presenza di coevi depositi marini e continentali terrazzati in aree poste a ridosso del gargano (apricena, san severo). 3. il supersintema del tavoliere di puglia come già accennato, il settore settentrionale del tavoliere di puglia è caratterizzato, sotto il profilo morfologico, da una serie di basse colline a tetto piatto, le cui superfici sommitali, poste a differenti quote sul livello del mare, sono spesso leggermente inclinate da monte verso valle (fig. 2). si tratta, soprattutto nell’area pedemontana (foglio 407 “san bartolomeo”), solo di lembi residui di paleosuperfici coperte da modesti spessori di depositi del pleistocene medio e superiore la cui correlazione è stata effettuata sulla base delle quote, della distanza dal fronte e dei caratteri sedimentologici; in tale settore, le paleosuperfici sono coperte unicamente da depositi continentali terrazzati. il substrato di questi depositi è rappresentato quasi ovunque dalle argille subappennine (figg. 2 e 3 – tav. 1); solo alcuni dei lembi più elevati e prossimi al bordo della catena poggiano su unità appenniniche (tav. 1). verso valle invece alcuni depositi continentali più recenti si rinvengono su superfici d’erosione incise parzialmente anche nei depositi continentali più antichi (fig. 2). la superficie di base di ogni singolo terrazzo è inclinata verso e, con angoli compresi tra circa 2.5° e 0.5° i cui valori decrescono da monte verso valle; inoltre, a parità di distanza dal margine dalla catena, i depositi più antichi quindi più alti in quota presentano valori angolari maggiori rispetto a quelli dei depositi più recenti (fig. 4): questo aspetto si osserva con grande regolarità su 184 tutta l’area investigata. nell’area del foglio 396 “san severo” prossima al gargano, i depositi continentali poggiano su superfici d’erosione intagliate anche in depositi terrazzati marini e/o di transizione che, a loro volta, poggiano in erosione sia sulle argille subappennine che su unità mesozoico-cenozoiche del margine sudoccidentale del rilievo del gargano. fig. 3 contatto erosivo fra le argille subappennine (asp) ed il sovrastante sintema di lucera (tlc) rispettivamente a torre montecorvino (a) e in località il seggio (b). si noti l’inclinazione della superficie erosiva verso est. erosional contact between the argille subappennine unit (asp) and the overlying lucera synthem (tlc) at torre montecorvino locality (a) and at il seggio locality (b). note that the erosional surface is gently inclined toward east fig. 2 carta geologica schematica e sezione geologica nel settore pedemontano dell’area analizzata (posta ad ovest di lucera). si noti che le unità sintemiche continentali poggiano in erosione sulle argille subappenine e/o unità sintemiche più antiche. inoltre la morfologia degli affioramenti suggerisce una graduale migrazione verso est dei sistemi terrazzati di conoide alluvionale via via più recenti e meno elevati. geological map and geological section across the higher sector of the analysed area (located west of lucera). continental synthems and subsynthems lies on erosional surfaces mainly on the argille subappennine unit and, locally, on older alluvial synthems and subsynthems. furthermore, the general morphology of outcrops clearly suggests a gradual estaward-oriented migration of younger terraced alluvial fan systems. moretti et al. 185 il riconoscimento di tali superfici e la loro estesa continuità laterale hanno permesso di definire differenti unità a limiti inconformi (sintemi): nel settore pedemontano, queste unità sono composte soltanto da depositi continentali mentre, nel settore perigarganico, in ogni unità sintemica, è stato riconosciuto un subsintema inferiore marino e/o di transizione sul quale poggia in erosione un subsintema continentale. dal più antico al più recente sono rappresentati da (tav. 1): sintema di lucera (pleistocene medio), sintema di cava petrilli (pleistocene medio) suddiviso in subsintema di colle degli ulivi e subsintema di masseria casillo, sintema di vigna bocola (pleistocene medio) costituito dal subsintema di san severo e dal subsintema di mass. pallante, sintema di masseria la motticella (pleistocene medio – superiore?) costituito dal subsintema di amendola e dal subsintema di mass. de grossi, sintema di foggia (pleistocene medio? – superiore), sintema di motta del lupo (pleistocene superiore) e sintema di mass. finamondo (pleistocene superiore). l’insieme di queste unità, che si estendono a differenti quote per l’intera area studiata, nella nuova cartografia geologica è stato inserito in una unità di rango maggiore (supersintema del tavoliere di puglia). il principale problema che riguarda le differenti unità inserite in questo supersintema concerne la loro attribuzione cronologica: le unità continentali non hanno offerto la possibilità di condurre analisi né dirette – datazioni radiometriche – né indirette – biocronologiche e/o tefracronologiche; quelle marine, per il loro contenuto faunistico e floristico sempre in facies di mare sottile, hanno fornito soltanto generiche indicazioni di età evoluzione geologica del settore settentrionale ... fig. 4 grafici dell’inclinazione della superficie basale dei sintemi in facies alluvionale. a. a parità di distanza dalla catena, i sintemi alluvionali più antichi poggiano su superfici più inclinate rispetto a quelli più recenti. 2. l’inclinazione delle superfici basali dei sintemi alluvionali misurate lungo il torrente motta montecorvino. tale regolare variazione dell’inclinazione delle superfici basali ha permesso la correlazione di affioramenti non continui. graphs showing main geometrical features of the basal surfaces of different alluvial synthems. a. basal surfaces measured at the same distance from the more external thrust is more inclined in the older synthems and gradually decreases in the younger ones. b. basal surfaces inclination measured along the motta montecorvino river. regular variations of the basal surface inclination allowed reliable correlations between not laterally continuous outcrops. 186 pleistocenica. malgrado queste limitazioni, la cronologia dei differenti depositi è stata dedotta sia da considerazioni di carattere regionale (ciaranfi & rapisardi, 1979; ciaranfi et al., 1979; ciaranfi et al., 1983; tropeano et al., 2002) che da considerazioni, anch’esse di tipo generale, sulle interazioni fra il generalizzato sollevamento dell’area e le marcate e cicliche oscillazioni del livello marino. tali oscillazioni, con ciclicità di circa 100 ka, a partire dall’inizio della cosiddetta mid-pleistocene revolution (maasch & saltzmann, 1990; berger & jansen, 1994; mudelsee & stattegger, 1997), tra 900 e 650 ka, si sono ripetute nell’intervallo di tempo che si estende da parte del pleistocene medio fino all’olocene. vengono di seguito descritti i principali caratteri sedimentologici dei depositi appartenenti alle singole unità sintemiche e subsintemiche del tavoliere di puglia, a partire da quella più antica, e ne viene indicata per ciascuna l’ interpretazione paleoambientale. l'analisi di facies è stata condotta su un gran numero di affioramenti ben distribuiti fra settore pedemontano e di pianura; nelle aree di pianura, inoltre sono stati eseguiti diversi sondaggi a carotaggio continuo per integrare i dati di superficie disponibili. 3.1 sintema di lucera (tlc) – pleistocene medio affiora solo nel settore pedemontano del tavoliere (dal thrust appenninico più esterno fino all’area di lucera). poggia in erosione sulle argille subappennine (figg. 3.a e 3.b) e, localmente (serra la guardia) sulle unità appenniniche più esterne. affiora in lembi residui allungati nel senso dei corsi fluviali attuali sulle alte colline situate ai piedi del fronte esterno della catena attorno ai 450 m (monte sti l lo, torre di montecorvino – fig. 3.a) e si rinviene gradualmente a quote decrescenti verso e (350 m il seggio; 310 m nei pressi di masseria venti versure; 245 m nell’alto di lucera). il sintema di lucera è costituito dai depositi alluvionali terrazzati più antichi rilevati nell’area in esame. verso monte, localmente, può essere rappresentato solo da blocchi metrici (con diametri fino a 5-6 m) a spigoli vivi o poco arrotondati che si rinvengono isolati. più spesso è rappresentato da ghiaie massive e blocchi (con diametri fino a 3-4 m) a prevalente componente carbonatica con abbondante matrice sabbiosa grossolana. le ghiaie sono prive di gradazione, poco selezionate (loc. monte stillo e torre di montecorvino) e le tessiture sono prevalentemente fango-sostenute e subordinatamente granulo-sostenute; verso valle, il sintema è caratterizzato da ghiaie meglio selezionate, con rare intercalazioni sabbiose (castello di lucera). localmente si osservano ciottoli di natura calcarenitica (costituiti da abbondante frazione bioclastica) non appartenenti ad unità appenniniche e che provengono dallo smantellamento di unità marine regressive o terrazzate più antiche non più presenti in affioramento. lo spessore è di circa 8-10 m. interpretazione: si tratta di unità continentali costituite da depositi di frana (nel settore più elevato) e da conoidi da prossimali a distali con prevalenti depositi tipo debris-flow. 3.2 sintema di cava petrilli (tvp) pleistocene medio affiora in tutta l’area d’interesse e poggia in erosione sulle argille subappennine, sulle unità appenniniche del thrust esterno affiorante (appena a ne di castelnuovo della daunia) e sulle unità carbonatiche mesozoico-cenozoiche del gargano. e’ costituito nel settore pedemontano unicamente da depositi alluvionali, mentre, nel settore pedegarganico sono state distinte due unità di rango inferiore (subsintemi), una inferiore marina ed una superiore continentale, separate da una chiara superficie erosiva. subsintema di colle degli ulivi (tvp1) affiora nel settore nord-occidentale dell’area investigata. le sezioni stratigrafiche più estese sono state osservate in località colle degli ulivi in corrispondenza di tagli stradali e ferroviari ed in alcune cave: si tratta di sezioni molto estese lateralmente (fino a qualche km) e relative prevalentemente alla porzione inferiore e media dell’unità. questà unità poggia in discordanza sulle argille subappennine e sulle unità mesozoico-plioceniche del gargano (la base è posta a circa 105 m s.l.m.). i depositi di questo subsintema si rinvengono indisturbati, in discordanza e con un chiaro rapporto di pinch-out verso e, al di sopra di faglie distensive che interessano le unità post-cretaciche del bordo occidentale del gargano. in affioramento quest’unità è costituita da sabbie e conglomerati poligenici in corpi canalizzati, lentiformi e/o progradanti, che mostrano rapide variazioni litologiche laterali. il limite superiore dell’unità è rappresentato da una superficie di erosione su cui poggia il sovrastante subsintema di masseria casillo; nell’area nord-occidentale, al di sopra di una superficie d’erosione, poggiano i depositi di unità più recenti (sintemi di vigna bocola e di motta del lupo). come accennato, questa unità mostra grande variabilità laterale dei caratteri di facies. l’affioramento più rappresentativo (ex stazione di poggio imperiale) consente l’osservazione di circa 30 m di successione (sui 35 m di spessore totale); esso è costituito dal basso verso l’alto da: 6 m di alternanze argilloso-sabbiose con rari livelli ghiaiosi; le argille mostrano laminazione piano-parallela, mentre le sabbie mostrano laminazione incrociata. i livelli ghiaiosi, con dimensioni massime dei ciottoli di circa 10 cm presentano sempre base erosiva con letti di clay-chip provenienti dal substrato argilloso; 8 m di sabbie ed arenarie con lenti ghiaiose. le sabbie presentano stratificazione incrociata a grande scala. localmente si osservano sia foreset sabbiosi con chiare direzioni di progradazione verso ne che strette forme erosive canalizzate riempite da sabbie a stratificazione incrociata (fig. 5.a); 15 m di alternanze fra ghiaie (e/o conglomerati) e sabbie. i corpi di ghiaie e di conglomerati aumentano in spessore e frequenza verso l’alto, come pure si osserva un aumento della dimensione dei ciottoli (diametro massimo fino ai 30 cm) nel medesimo verso. nella porzione inferiore i corpi ghiaiosi sono lentiformi (fig. 5.b) con base erosiva su sabbie a laminazione incrociata; verso l’alto dominano invece le forme canalizzate (fig. 5.b). lungo le nuove trincee ferroviarie (tracciato bari-bologna) inoltre è possibile osservare le variazioni laterali di questa unità. verso se il corpo sabbioso-conglomeratico moretti et al. descritto diviene gradualmente solo sabbioso (e/o arenaceo) con numerosi interstrati argillosi e livelli sabbiosi a clay-chip. proseguendo nella stessa direzione, lo spessore diminuisce gradualmente e si arriva a sabbie finissime e molto selezionate, a laminazione incrociata, con abbondante contenuto in frammenti di pectinidi e di ostreidi (masseria zingari). verso no, in affioramenti situati al di fuori dell’area qui analizzata (località coppa di franceschiello affioramenti descritti da aucelli et alii, 1997), lo spessore dell’unità aumenta e si osserva187 fig. 5 a. subsintema di colle degli ulivi (tvp1). porzione sabbiosa intermedia: forma di fondo tipo duna con direzioni delle correnti trattive verso ne. b. porzione superiore: si noti l'aumento verso l'alto sia della dimensione dei ciottoli che della frequenza delle forme erosive canalizzate. colle degli ulivi subsynthem (tvp1): a. intermediate sandy portion: dune with traction currents toward ne. b. upper gravelly portion: both gravel dimension and frequency of channelised erosional surfaces increase upward. evoluzione geologica del settore settentrionale ... no dapprima corpi sabbioso-arenacei organizzati in regolari foreset, passanti lateralmente ad un corpo prevalentemente ghiaioso-conglomeratico con caratteri simili a quelli descritti per la ex stazione di poggio imperiale. lo spessore massimo è di 35 m. interpretazione: l’insieme dei caratteri descritti indica che il subsintema di colle degli ulivi si è depositato in un ambiente marino transizionale di delta passante lateralmente ad ambienti di mare sottile. i corpi ghiaiosi caratterizzavano i canali attivi del delta e passavano lateralmente e distalmente a corpi sabbiosi progradanti verso ne sui depositi prevalentemente argillosi di prodelta. nelle aree contigue al deposito deltizio si aveva la formazione di spiagge sabbiose che si attestavano su alti morfologici costituiti dalle unità carbonatiche garganiche, formando cordoni litorali e insenature più o meno protette. subsintema di masseria casillo (tvp2) affiora in lembi residui nei pressi del margine della catena ad oltre i 400 m di quota, e più estesamente verso e, dai 350 m (casone san paolo), a quote progressivamente decrescenti (240 m masseria iuvara; 190 m cava petrilli e a s di lucera) sino a quote intorno ai 130-135 m nella trincea ferroviaria nei pressi della stazione di poggio imperiale. verso monte, è costituito da blocchi (fino ad 1m di diametro) e da ghiaie di prevalente natura carbonatica con abbondante matrice sabbioso-argillosa, massive, non selezionate (fig. 6.a); verso valle è rappresentato da ghiaie e sabbie in strati e lenti, discretamente organizzate, laminate, con canalizzazioni, chiare embriciature (figg. 6.b, c), che passano verso l’alto a depositi meno selezionati massivi e leggermente più grossolani (loc. cava petrilli). localmente sono stati osservati blocchi di conglomerati poligenici ben selezionati e finemente cementati da calcite, probabilmente provenienti dallo smantellamento di depositi marini regressivi o terrazzati più antichi (fig. 6.d) e non più osservabili in affioramento. verso est (stazione di poggio imperiale) è rappresentata da circa 5 m di conglomerati poligenici con abbondante matrice sabbiosa rossastra. i ciottoli presentano una selezione granulometrica pressoché nulla ed il diametro massimo è prossimo a 30 cm. si presentano mal stratificati e, solo a luoghi, è possibile riconoscere superfici erosive canalizzate. lo spessore massimo è attorno ai 15 m. interpretazione: l’ambiente di sedimentazione è attribuibile ad un sistema di conoidi coalescenti (con facies da prossimali a distali) passanti gradualmente nel settore più orientale ad un sistema braided con barre ghiaiose. ogni volta che è possibile osservare le variazioni verticali di facies si osserva una chiara tendenza coarsening-upward che testimonia la migrazione di facies di conoide su facies braided ed in generale di facies più prossimali su facies distali. 3.3 sintema di vigna bocola (tpb) – pleistocene medio caratterizza ampie aree del settore pedemontano analizzato e poggia su una superficie di erosione sulle argille subappennine e, localmente, sul sintema di cava petrilli. nel settore occidentale affiora in lembi residui a quote variabili dai 375 m ai 270 m lungo gli alti morfologici adiacenti ai corsi d’acqua principali (canale di motta montecorvino, t. salsola) e, più ad e, caratterizza ampi settori di alto morfologico (masseria quaranta versure, casone schiavone). in tutte queste aree è caratterizzato unicamente da depositi alluvionali. nel settore più orientale, è formato da due subsintemi (subsintema di san severo con depositi marini e subsintema di masseria pallante con depositi alluvionali) separati da limite inconforme. subsintema di san severo (tpb1) caratterizza un esteso settore nella porzione occidentale dell’area investigata (tav. 1): superiormente è limitato da una spianata morfologica che raggiunge quote variabili fra i 100 e i 110 m s.l.m. le sezioni più spesse massimo 7 m ed estese massimo 50-70 m di questa unità sono ubicate nei dintorni di san severo (stazione di san severo, località tiro a segno, c. stilla, c. masselli e san antonino da capo): sono relative unicamente alla porzione superiore dell’unità. la base del subsintema, posta a circa 55-60 m s.l.m., si rinviene al di sopra di una superficie d’erosione sia sulle argille subappennine che sul sintema di cava petrilli; a tetto il subsintema è coperto, al di sopra di una superficie inconforme, sia dai depositi del subsintema di masseria pallante che da quelli di sintemi più recenti (sintema di masseria la motticella, sintema di motta del lupo). in affioramento quest’unità è composta (stazione di san severo, località tiro a segno, c. stilla e c. masselli) a luoghi da alternanze siltoso-sabbiose, da arenarie con letti di concentrazioni macrofossilifere (principalmente ostrea sp. e pecten sp. fig. 7) e da argille siltose brunastre (san antonino da capo). la successione litostratigrafica dell’intera unità è stata attraversata da un sondaggio a carotaggio continuo (ss1) perforato ad hoc poco ad ovest della città di san severo (per l'ubicazione vedi foglio geologico 1:50.000, 396 "san severo", s.g.i., in stampa). la stratigrafia del sondaggio ss1, perforato per circa 40 m, ha consentito di descriverne in dettaglio, dal basso, i caratteri litologici, sulla base dei quali sono state effettuate correlazioni con le sezioni osservate in affioramento: in contatto erosivo sulle argille subappennine si rinvengono circa 5 m di alternanze argilloso-sabbiose laminate di colore verde e giallastro, fortemente bioturbate e con abbondante contenuto in materia organica; la laminazione, quando non obliterata da bioturbazione, è piano-parallela. i sedimenti sabbioso-siltosi ed i fossili si mostrano spesso fortemente ossidati; seguono circa 15 m di sabbie giallastre ben selezionate con interstrati siltoso-argillosi. la granulometria diminuisce verso l’alto da sabbie medie e grossolane a sabbie fini mentre aumenta lo spessore e la frequenza degli interstrati argillosi; la bioturbazione è molto diffusa e si mostra anch’essa più spinta verso l’alto. questo intervallo stratigrafico corrisponde in affioramento alla sezione della stazione di san severo posta a circa 73-75 m s.l.m. verso l’alto seguono circa 5 m di argille brune e verdi con rare lamine siltoso-sabbiose ed elevato contenuto in materia organica: una diffusa bioturbazione ha obliterato ogni struttura sedimentaria primaria. in questo intervallo stratigrafico, analisi micropalentologiche su campioni raccolti dagli interstrati argillosi o siltoso188 moretti et al. 189 fi g. 6 s ub si nt em a d im as se ria c as ill o (t v p 2) :a .s et to re p ed em on ta no :g hi ai e co n ab b on d an te m at ric e sa b b io so -a rg ill os a (c on oi d e p ro ss im al e) .b .s et to re ce nt ra le :g hi ai e e sa b b ie in st ra ti e le nt ic on fr eq ue nt ic an al iz za zi on i. c . s et to re ce nt ra le : gh ia ie a d iv er sa gr an ul om et ria co n ch ia re em b ric ia tu re ch e in d ic an o p ro ve ni en ze d a o . d . s et to re ce nt ra le : lo ca lm en te si os se rv an o b lo cc hi m et ric id ic on gl om er at im ar in i( c g) e cl as ti ar gi llo si p ro ve ni en ti d al le ar gi lle su b ap p en ni ne (a s p ). m as se ria c as ill o su b sy nt he m (t v p 2) :a .p ie d m on t se ct or :g ra ve ls w ith ab un d an t sa nd ycl ay ey m at rix (p ro xi m al al lu vi al fa n) .b .c en tr al se ct or :g ra ve la nd sa nd in b ed s an d le ns es w ith ab un d an t ch an ne lli se d fe at ur es . c . c en tr al se ct or : in te rb ed d ed gr av el s w ith d iff er en t gr ai nsi ze , no te th ey ar e im b ric at ed (in d ic at in g a w p ro ve na nc e) . d . c en tr al se ct or : lo ca lly , m et ric b lo ck s of m ar in e co ng lo m er at es (c )a nd la rg e cl ay ch ip s (a ar gi lle su b ap p en ni ne )o cc ur . evoluzione geologica del settore settentrionale ... argillosi, mostrano un contenuto poco abbondante e scarsamente diversificato in foraminiferi; l’associazione è composta principalmente da bentonici, tra cui ammonia beccarii linné, bolivina. elongata d’orbigny, cibicides lobatulus walker & jacobs, elphidium crispum linné, elphidium granosum (d’orbigny) e valvulineria bradyana (fornasini); sono inoltre presenti rari globigerinidi e valve di ostracodi. il contenuto micropaleontologico si riduce ulteriormente verso l’alto dove è rappresentato da ammonia beccarii, cibicides lobatulus ed elphidium crispum. le associazioni a nannofossili calcarei sono mal preservate in tutta l’unità e non risultano indicative dal punto di vista biostratigrafico; sono infatti rappresentate principalmente da small gephyrocapsa (sensu rio et al., 1990), pseudoemiliania lacunosa (kemptner), reticulofenestra spp. e da comuni discoasteridi pliocenici rimaneggiati, oltre che da frequente rimaneggiamento di specie pre-plioceniche. le sezioni di case stilla e case giuliani, poste a circa 83 m s.l.m., sono riferibili a questo intervallo stratigrafico. la parte sommitale della succesione perforata consta di un intervallo di circa 10 m costituito in basso da argille verdastre con abbondante presenza di concrezioni calcaree di origine diagenetica (caliche), di sabbie da medie a fini ben selezionate a laminazione incrociata passanti in alto ad argille brunastre a laminazione piano-parallela. queste ultime affiorano anche nella sezione di località san antonino da capo (circa 102 m s.l.m.). il contenuto micropalentologico in questo intervallo è assente. lo spessore totale dell’unità è di circa 35 m. interpretazione: tutti i caratteri di facies indicano che il subsintema di san severo si è prodotto in un contesto marino di baia più o meno protetta. si tratta di una successione marina e di transizione con un generale trend regressivo. la base trasgressiva è rappresentata da circa 5 m di alternanze argilloso-siltoso-sabbiose deposte in ambienti di bassa energia e di transizione (laguna costiera?). verso l’alto si passa repentinamente a sabbie da grossolane a fini di ambienti marini relativamente già profondi (shoreface inferiore) in un contesto di baia protetta. verso l’alto si torna a condizioni di baia ristretta e ad ambienti via via più prossimali fino alle sabbie a laminazione incrociata ed alle argille brunastre superiori che probabilmente rappresentano nuovamente ambienti di transizione al continentale. subsintema di masseria pallante (tpb2) verso monte (a quote variabili fra 375 e 270 m), è costituito da ghiaie con blocchi anche metrici, con abbondante matrice sabbiosa giallastra, a luoghi granulo-sostenute; verso valle è caratterizzato da ghiaie più sottili sufficientemente organizzate, con livelli sabbiosi. nei settori orientali affiora sempre al di sopra dei 100 m di quota. la sezione stratigrafica meglio esposta è situata nei pressi di masseria ciamponetto (non lontano dall’abitato di lucera). lo spessore osservabile è nell’ordine dei 10 m, ma non è visibile il contatto con le sottostanti argille subappennine affioranti nei campi coltivati limitrofi. la porzione basale affiorante, spessa circa 3,50 m, è costituita da sabbie ed arenarie giallastre silicoclastiche con granulometria da fine a media con rare intercalazioni argillose. presentano tessitura generalmente massiva e solo a luoghi è visibile la laminazione piano-parallela. verso l’alto si passa a circa 2.5 m di sabbie ed arenarie con granulometria da media a grossolana con rare lenti argillose e livelli di ghiaie. sabbie ed arenarie si rinvengono in strati decimetrici a base erosiva e sono caratterizzati da alternanze di strati a laminazione piana e strati a laminazione incrociata. chiude la successione una porzione ghiaioso-conglomeratica di circa 4 m di spessore. si tratta di fitte alternanze sabbioso-ghiaiose con un graduale aumento dello spessore e della frequenza degli strati ghiaiosi verso l’alto. gli strati decimetrici sono gradati con base spesso erosiva sulla quale si rinvengono ghiaie ben selezionate, sabbie grossolane a laminazione piana ed incrociata ed infine sabbie fini con ripples asimmetrici spesso rampicanti. nella porzione superiore dominano invece ghiaie poco selezionate (ciottoli con diametro variabile fra pochi cm e 20 cm) con abbondante matrice siltoso-sabbiosa che si rinvengono spesso all’interno di forme canalizzate. i lavati ottenuti dai campioni presi sia nelle lenti argillose che nei silt e nelle sabbie fini sono risultati sterili. lo spessore massimo è nell’ordine dei 15 m. interpretazione: l’ambiente di sedimentazione è riferibile nei settori occidentali a conoidi coalescenti passanti nei settori orientali ad una piana braided con barre ghiaiose. nei settori orientali (all’altezza di lucera), si osservano anche variazioni verticali di tipo coarsening-upward. si passa infatti via via dalle sabbie fini ed argille probabilmente ascrivibili ad ambienti alluvionali di bassa energia (aree marginali di esondazione) ad ambienti alluvionali più prossimali e di alta energia rappresentati dalle sequenze gradate (depositi di piena) e dalle ghiaie superiori con caratteri tessiturali simili a quelli descritti per i sintemi più antichi (transizione conoide distale – piana braided). 3.4 sintema di masseria la motticella (mlm) pleistocene medio superiore? poggia in erosione sulle argille subappennine e, 190 fig. 7 subsintema di san severo (tpb1). sabbie e silt a laminazione piano-parallela. si nota la presenza di livelli a pectinidi (p in basso) e ad ostree (o in alto). san severo subsynthem. sand and silt with parallel lamination. note the presence of beds with concentration of pectinids (p in the lower part) and ostreids (o upper part). moretti et al. localmente, sul sintema di vigna bocola. caratterizza ampie porzioni dell’area analizzata: affiora in lembi residui allungati all’incirca e-o nel settore più occidentale (a quote comprese fra 400-350 m s.l.m.) e, verso valle, su ampie spianate debolmente inclinate verso est (da 250 m a 130 m s.l.m.). nell’area orientale sono state distinte due unità subsintema di amendola in facies marina e subsintema di masseria de grossi in facies continentale che, contrariamente ai sintemi più antichi (tvp e tpb), non appaiono chiaramente separate da un limite inconforme ed il rapporto tra le due unità non è visibile e può essere solo dedotto in base alle quote di affioramento ed ai rapporti con le altre unità. nei sintemi più antichi invece le facies continentali poggiano in erosione sulle sottostanti facies marine (tvp2 in erosione su tvp1 e tpb2 in erosione su tpb1). subsintema di amendola (mlm1) affiora in un’estesa area nella metà centro-occidentale della zona studiata. la base dell’unità è posta a circa 23-25 m s.l.m. poggia con contatto erosivo sulle argille subappennine e, localmente, sui depositi marini del subsintema di san severo; il limite superiore del subsintema è rappresentato da una spianata morfologica che raggiunge quote fra i 55 e i 65 m s.l.m. la migliore sezione di questa unità affiora per circa 5 m nei pressi di masseria il casone. si tratta di una sezione estesa lateralmente per circa 30 m e relativa alla porzione superiore dell’unità: è costituita in basso da sabbie prevalentemente calcaree fini (1 m circa) fortemente bioturbate e con abbondanti frammenti di gusci di bivalvi – in particolare pinna nobilis linné dispersi nel sedimento; verso l’alto si passa ad uno strato lentiforme (spessore variabile da pochi cm fino a 1 m) ben cementato costituito da calciruditi con abbondanti resti di bivalvi e gasteropodi sia in frammenti che interi; chiudono la successione sabbie ed arenarie da fini a grossolane a stratificazione incrociata concava. anche il subsintema di amendola è stato caratterizzato attraverso l’esecuzione di un sondaggio diretto a carotaggio continuo (ss3) perforato ad hoc a sud est della città di san severo (per l'ubicazione vedi il foglio geologico 396 "san severo", s.g.i., in stampa). al di sopra delle argille subappennine che si rinvengono a fondo pozzo, in brusco contatto erosivo, si osservano: 3 m di sabbie fini giallastre con rare intercalazioni siltose ed argillose. presentano laminazione piano parallela in basso mentre verso l’alto la bioturbazione ha obliterato ogni struttura sedimentaria primaria; seguono circa 10 m di silt grigiastri e subordinatamente sabbie giallastre entrambi molto bioturbati con abbondante presenza di materia organica. solo raramente si osservano lamine piano-parallele. in questa porzione dell’unità il contenuto in foraminiferi è generalmente prevalente rispetto alla frazione inorganica. l’associazione è rappresentata principalmente da foraminiferi bentonici tra cui ammonia beccarii linné, cibicides lobatulus, elphidium crispum, rarissimi esemplari di hyalinea baltica (schroëter), quinqueloculina padana perconig, textularia agglutinans, valvulineria bradyana fornasini, oltre che più rari esemplari di brizalina alata sequenza, bulimina marginata, b. elongata, fursenkoina tenuis sequenza; fra i planctonici invece sono presenti globigerinoides ruber (d’orbigny), globorotalia inflata (d’ orbigny), orbulina universa e globigerina spp. l’associazione a nannofossili calcarei contiene fra i taxa più significativi pseudoemiliania lacunosa, small gephyrocapsa (sensu rio et al., 1990) e medium gephyrocapsa (sensu rio et al., 1990), che consentono di indicare solo una generica età pleistocenica; chiudono la successione sabbie giallastre (15 m circa) che mostrano un chiaro aumento di granulometria verso l’alto: sono costituite in basso da una alternanza ordinata di strati di sabbie medie poco bioturbate e strati di sabbie fini bioturbate, con interstrati di silt ed argille con bioturbazioni di piccole dimensioni; verso l’alto diminuisce la bioturbazione e la presenza di interstrati siltosi, e sono ben visibili laminazione piana ed inclinata a basso ed alto angolo in sabbie da medie a grossolane ben selezionate e con presenza, a luoghi, di probabili superfici erosive in corrispondenza di brusche variazioni granulometriche. quest’intervallo corrisponde in parte alla porzione affiorante nella sezione de “il casone”. in questa porzione sommitale il contenuto micropaleontologico è relativamente scarso e rappresentato principalmente da ammonia beccarii, cibicides lobatulus, elphidium crispum e rarissimi foraminiferi planctonici. lo spessore massimo è nell’ordine dei 35 m. interpretazione: si tratta di una successione marina deposta in una baia protetta con un chiaro trend generale di tipo regressivo rappresentata da un complesso sabbioso depositatosi quasi interamente in una shoreface inferiore al passaggio all’offshore dominata solo episodicamente dall’azione delle onde di tempesta. solo la base probabilmente può riferirsi ad ambienti di transizione. la porzione superiore (circa 10 m) invece possiede caratteri di maggiore prossimalità (shoreface media e superiore) espressi dall’azione di intensa rielaborazione ad opera delle onde di tempesta. subsintema di masseria de grossi (mlm2) si rinviene in discordanza erosiva sulle argille subappennine, sul subsintema di san severo e sui sintemi più antichi. il limite superiore è rappresentato da una superficie di erosione al di sopra della quale si rinvengono i sintemi più recenti (sintema di foggia e sintema di motta del lupo). verso monte è costituito da ghiaie disorganizzate, in abbondante matrice sabbiosa grossolana, con clasti essenzialmente di natura carbonatica, e blocchi fino a 0.7 m di diametro. verso valle, a quote inferiori ai 100 m s.l.m., invece l’unità è caratterizzata da ghiaie discretamente organizzate, alternate a sabbie e limi sabbiosi giallastri. la sezione più rappresentativa è situata nei pressi di masseria de grossi, sulla strada statale 160 “san severo-lucera” ed è costituita da 4 m di alternanze sabbioso-conglomeratiche. i conglomerati a luoghi ghiaie formano lenti metriche e sono costituiti da ciottoli poligenici centimetrici abbastanza ben selezionati; a luoghi le embriciature indicano provenienze da ovest. le sabbie, a granulometria media, presentano laminazione piana ed incrociata. lo spessore massimo è nell’ordine dei 10 m. interpretazione: verso monte è rappresentato da facies di conoide da prossimale a distale passanti gradual191evoluzione geologica del settore settentrionale ... mente verso est ad un ambiente di sedimentazione riferibile ad una piana braided prevalentemente ghiaiosa. 3.5 sintema di foggia (tgf) – pleistocene superiore nell’area occidentale, a quote tra 75 m e 55 m, l’unità poggia, tramite una superficie di erosione, sulle argille subappennine, mentre nell’area orientale giace anche sui depositi del sintema di masseria la motticella. il limite superiore è inconforme ed è rappresentato da una superficie di erosione su cui poggia localmente il sintema di motta del lupo. a monte è caratterizzato da depositi ciottolosi granulo sostenuti, con scarso grado di organizzazione, verso valle, è costituito da un’alternanza di livelli sabbiosi e siltoso-argillosi grigio scuri e di sottili orizzonti (spessi fino a 50 cm) di ghiaie discretamente organizzate ed embriciate. nei settori occidentali (quote comprese fra 75 m e 55 m), questo sintema presenta cattive condizioni di affioramento. solo nei pressi di masseria sterparone e masseria casarsa sono stati osservati circa 30 cm di sabbie medie e grossolane con rari ciottoli al di sotto di un suolo antropizzato in due trincee di modesta profondità. lo spessore massimo è nell’ordine dei 10 m. interpretazione: nei settori occidentali si riconoscono depositi di ambiente di conoide alluvionale passanti rapidamente verso est ad ambienti braided anche con barre di sabbie grossolane. verso valle si osservano probabilmente depositi riferibili ad una piana alluvionale via via di minor gradiente topografico. 3.6 sintema di motta del lupo (tlp) pleistocene superiore e’ l’unità a maggiore estensione areale; affiora in un ampio settore pianeggiante compreso fra quote prossime ai 125 m (area occidentale) fino a circa 30 m s.l.m. (area sud-orientale). i depositi di questo sintema giacciono in discordanza su tutte le unità più antiche. il limite superiore, di tipo inconforme, è rappresentato da una superficie di erosione al di sopra della quale poggia il sintema di masseria finamondo. nel settore occidentale è costituito da depositi sabbioso-limosi di colore marrone chiaro con lenti ghiaiose aventi spessore variabile dal decimetro al metro discretamente organizzate. a luoghi si rinvengono livelli centimetrici di limi nerastri carboniosi con gasteropodi polmonati in pessimo stato di conservazione. l’unica sezione osservata in affioramento nel settore orientale è situata in località motta del lupo: si tratta di circa 2 m di fitte alternanze argilloso-siltose. i silt sono brunastri mentre le argille di colore verdastro, la laminazione è sottile (lamine sempre al di sotto del cm di spessore) e sempre piano-parallela. trattandosi dell’unità continentale più estesa arealmente ed essendo così scarsi gli affioramenti, una più esauriente descrizione di questo sintema è stata effettuata attraverso l’esecuzione di un sondaggio a carotaggio continuo in un’area prossima al torrente candelaro (in località mass. mezzanagrande ss4) (per l’ubicazione vedi foglio geologico 396 “san severo”, s.g.i., in stampa). in quest’area, il sintema di motta del lupo poggia in erosione su una unità marina non presente in affioramento. con ogni probabilità quest’ultima unità potrebbe costituire un subsintema marino appartenente al sintema di motta del lupo (in analogia con quanto osservato nei sintemi più antichi); la mancanza di dati sulla base di tale unità e la sua assenza in affioramento non hanno permesso l’istituzione di un subsintema marino. il sintema di motta del lupo è costituito quindi essenzialmente da depositi continentali: si tratta di depositi argillosi e subordinatamente sabbiosi e siltosi; i principali caratteri stratigrafici e sedimentologici desunti dall’osservazione delle carote possono essere così riassunti: 8 m di argille e silt di colore verdastro a laminazione pianoparallela, che poggiano in erosione su sabbie ed arenarie marine; molto abbondanti croste calcaree (caliche) di origine diagenetica e lamine siltose rossastre. il contenuto micropaleontologico è poco abbondante e rappresentato da rari individui di ammonia beccarii ed elphidium crispum, spesso rotti ed abrasi, da frustoli vegetali e da rari ostracodi. verso l’alto si rinvengono livelli sabbiosi a laminazione incrociata ed un livello di ghiaie poligeniche con abbondante matrice sabbiosa arrossata. verso l’alto, per circa 22 m di spessore, argille brune e verdi con laminazione piano-parallela ed abbondante materia organica diffusa, nonché bioturbazioni a scala centimetrica e millimetrica; a varie altezze rare lamine siltose. il contenuto micropaleontologico è rappresentato da comuni o abbondanti ostracodi, da frammenti di gasteropodi e, in alcuni campioni, da rarissimi esemplari di ammonia beccarii. verso l’alto si osservano inoltre oogoni di carofite. alla profondità di 36,3 m si osserva un livello di circa 10 cm di silt nerastri con una concentrazione di minerali femici. lo spessore aumenta da ovest verso est, passando da pochi metri nel settore occidentale (5-6 m) fino ad un massimo di 30 m nel settore prossimo al t. candelaro. interpretazione: il sintema di motta del lupo, sulla base dei caratteri desunti dal sondaggio a carotaggio continuo, è interpretabile come un deposito di piana alluvionale; nella porzione inferiore dominano argille, sabbie e subordinatamente ghiaie di ambiente alluvionale con condizioni idrodinamiche anche di moderata energia; verso l’alto si rinvengono argille brune e verdi di ambienti alluvionali associati ad aree marginali di esondazione o paludose con acqua stagnante. solo i depositi canalizzati nel settore occidentale mostrano a luoghi facies di una piana braided con barre prevalentemente sabbiose. 3.7 sintema di masseria finamondo (tpf) pleistocene superiore questi depositi affiorano diffusamente solo nell’area orientale della piana alluvionale. sono elevati di pochi metri 6-9 m al massimo al di sopra dei depositi alluvionali attuali e subattuali e formano estese aree subpianeggianti, che sono comprese fra 45 e 35 m di quota s.l.m.. formano dei terrazzi, limitati da modesti orli verso l’ampio alveo del t. candelaro e dei suoi affluenti, lungo il quale si sviluppa la piana alluvionale attuale. questa unità giace su un superficie d’erosione sul sintema di motta del lupo e, a luoghi, anche su depositi più antichi. in affioramento non sono state 192 moretti et al. osservate sezioni stratigrafiche di riferimento; la ricostruzione stratigrafica di questo sintema è stata ricavata da osservazioni condotte su carote di un sondaggio perforato ad hoc (ss4), già utilizzato per caratterizzare il sintema di motta del lupo. il sondaggio ha attraversato 27 m di argille con rari intervalli siltosi. dal basso si ricostruisce la seguente successione: 2 m di fitte alternanze argilloso-sabbiose a laminazione piano parallela ed incrociata a basso angolo, di colore giallastro. le sabbie sono ben selezionate e non contengono matrice. il contenuto micropaleontologico dei campioni argillosi è relativamente abbondante ed è rappresentato da un’associazione a foraminiferi in buono stato di preservazione: sono stati riconosciuti ammonia beccarii, bulimina marginata, globobulimina affinis d’orbigny, globigerinoides ruber e orbulina universa. 3 m di alternanze ghiaioso-sabbiose: le ghiaie sono poligeniche ed il diametro massimo dei ciottoli non supera il centimetro; le sabbie sono fortemente arrossate e prive di strutture sedimentarie. l’associazione a foraminiferi raccolta nelle sabbie è in discreto stato di preservazione; sono presenti ammonia beccarii, bulimina marginata, globobulimina affinis e rari individui di globigerinoides ruber, e di orbulina universa. verso l’alto circa 8 m di argille brune ben laminate, con rarissime lamine siltose e sabbiose, con abbondante terra rossa; in basso la laminazione è pianoparallela e verso l’alto diviene incrociata a basso angolo. rari sono i frammenti di macrofossili, le valve di ostracodi e rarissimi i foraminiferi, spesso rotti ed abrasi. chiudono la successione circa 13 m di argille brune con più frequenti livelli sabbiosi e siltosi; le argille mostrano laminazione piano-parallela, mentre le sabbie ed i silt grossolani presentano a luoghi ripples asimmetrici e laminazioni incrociate a basso angolo; abbondante è la presenza di materia organica; in alto argille nerastre prive di strutture sedimentarie e suoli siltosi con abbondanti concrezioni calcaree (caliche) di origine diagenetica. rari frammenti di macrofossili, di ostracodi e rarissimi foraminiferi rotti o abrasi. spessore massimo di circa 27 m. interpretazione: per quanto riguarda i caratteri paleoambientali, il sintema di masseria finamondo è costituito in basso da sabbie ed argille di ambiente marino o transazionale (tipo baia). non si è scelto di istituire un subsintema marino in quanto questa parte della successione non è presente in affioramento (si rinviene all’incirca al livello del mare attuale, -25 m in ss4). in erosione su questa porzione marina di transizione si rinvengono bruscamente sabbie e ghiaie già di ambiente alluvionale che passano via via verso l’alto prima ad argille nerastre di palude con abbondante contenuto in materia organica ed infine ad argille e silt di ambiente alluvionale (probabilmente connessi ad aree marginali di esondazione). 4. evoluzione paleogeografica e sedimentaria del settore settentrionale del tavoliere di puglia l’insieme dei dati esposti, che riguarda principalmente il riconoscimento di superfici di unconformity a grande estensione areale, i caratteri di facies dei diversi depositi ed i rapporti stratigrafici fra depositi marini e sedimenti continentali, rappresenta un set di capisaldi ai quali collegare la ricostruzione paleogeografica e l’evoluzione sedimentaria di questa porzione del tavoliere di puglia nel pleistocene medio e superiore. occorre sottolineare che il quadro paleogeografico che viene presentato è da intendersi ovviamente al netto delle oscillazioni eustatiche. pleistocene medio – sintema di lucera (fig. 8.a). per questa fase, la posizione della paleolinea di costa può essere solo supposta in quanto manca la registrazione sedimentaria di depositi marini. il sistema di conoidi coalescenti occupava una larga fascia di questo settore del tavoliere e si sviluppava già in valli incise nelle quali sedimentavano essenzialmente depositi tipo debris flow. erano già attive cannibalizzazioni a scapito di unità terrazzate più antiche (sia marine che continentali). il sistema di conoidi mostrava i caratteri tipici delle conoidi di clima arido (ori, 1988): nel settore più occidentale si sviluppavano frane e conoidi alluvionali da prossimali a distali, con scarsa selezione granulometrica. tale sistema raggiungeva aree molto prossime alla paleolinea di costa. l’area di alimentazione era limitata al settore esterno dell’appennino (ad eccezione delle conoidi del fortore con area di alimentazione più grande ed interna – fig. 8.a) giacché si riconoscono unicamente clasti provenienti dalle unità carbonatiche che caratterizzano tale settore del subappenino dauno. pleistocene medio – sintema di cava petrilli (fig. 8.b) a causa del sollevamento regionale, il sistema di conoidi con caratteri simili alle precedenti si sviluppava in valli ancor più incise, spostandosi gradualmente verso una posizione della linea di costa posta più ad est. questo sistema, alimentato unicamente dal settore esterno dell’appennino, passava lateralmente ad una stretta piana braided che si sviluppava nei pressi della paleolinea di costa. la posizione della paleolinea di costa è registrata dai depositi di transizione (deltizi e marini) affioranti a nord di apricena. in quest’area però giungevano anche gli apporti dalle unità più interne appenniniche: questo è indicato dalla posizione nella quale è localizzato il paleodelta del t. fortore, come sostenuto da spalluto & moretti, 2006 (in parziale accordo anche con le ricostruzioni paleogeografiche di aucelli et al., 1997). pleistocene medio – sintema di vigna bocola (fig. 8.c) il sollevamento regionale e, probabilmente, l’attività di un importante lineamento strutturale posto a nord di apricena (aucelli et al. ciaranfi, 1997; spalluto & moretti 2006) modificavano sostanzialmente il quadro paleogeografico. il fortore migrava verso nord-ovest e la posizione del suo delta si trasferiva verso nord, mentre il settore meridionale diventava un’estesa area di baia protetta, interessata da sedimentazione marina e di transizione di bassa energia (subsintema di san severo) con basso idrodinamismo. i depositi marini venivano unicamente alimentati dai sistemi alluvionali che si sviluppavano in profonde valli incise (e con limitate aree di alimentazione) conoidi passanti lateralmente a piane braided del subsintema di masseria pallante. 193evoluzione geologica del settore settentrionale ... 194 fig. 8 schema di evoluzione paleogeografica del tavoliere di puglia nel pleistocene medio-superiore. a. all’inizio del pleistocene medio, si sviluppano sistemi di conoide alluvionale coalescenti (c) e brevissimi corsi d’acqua braided (br). i depositi marini regressivi più antichi (dr) e le argille subappennine (asp) sono già in erosione. b. in seguito, a causa del sollevamento regionale, la linea di costa si sposta verso est. quest’ultima è registrata dai depositi deltizi (d) e marini prossimali (m) del subsintema di colle degli ulivi (tvp1). anche il subsintema alluvionale tvp2 (conoidi c e braided br) si sposta verso est e continua l’erosione delle argille subappennine (asp) e dei depositi marini regressivi (dr). c. l’attività di una faglia e-w in un’area posta a nord di san severo (si veda spalluto & moretti, 2006) determina la formazione di uno stretto golfo con depositi marini e/o di transizione (m) del subsintema di san severo (tpb1). il corso del fortore si sposta verso nw e l’area di interesse diviene alimentata unicamente dai corsi d’acqua con piccoli bacini di alimentazione e ristretti al settore esterno del subappennino dauno. d. alla fine del pleistocene medio, il golfo diviene più stretto e con scarso idrodinamismo; sedimentano depositi marini prossimali e di transizione (m) del subsintema di amendola (mlm1). tale golfo viene alimentato dai sistemi alluvionali del subsintema di masseria de grossi (mlm2). e. nel pleistocene superiore i sistemi alluvionali (tgf, tlp e tpf) continuano a spostarsi verso est seguendo la linea di costa verso l’attuale golfo di manfredonia. f. quadro geografico attuale. moretti et al. pleistocene medio-superiore? – sintema di masseria la motticella (fig. 8.d) i depositi di mare protetto (simili a quelli del sintema di vigna bocola precedente) si riproponevano con una paleolinea di costa posta a quote inferiori; sedimentavano depositi marini e di transizione ancora in condizioni di basso idrodinamismo (subsintema di amendola). il sistema di conoidi alluvionali e piane braided caratterizzava le valli sempre più incise, poste via via più ad est (subsintema di masseria de grossi). pleistocene superiore sintema di foggia, sintema di motta del lupo, sintema di masseria finamondo (fig. 8.e) nel pleistocene superiore, la paleolinea di costa migrava gradualmente verso l’attuale golfo di manfredonia, come è testimoniato dai depositi marini non presenti in affioramento ma riconosciuti nella perforazione ss4. i sistemi alluvionali si sviluppavano su aree vaste e mostravano una repentina perdita nella capacità di trasporto. nel sintema di foggia si formavano ancora ristrette aree di coalescenza delle conoidi, che passavano lateralmente a piane braided prevalentemente sabbiose, mentre nei sintemi più recenti le facies erano rappresentate principalmente da depositi di piana costiera (e/o aree marginali di esondazione). considerazioni conclusive i rilevamenti di dettaglio e l’analisi di facies effettuati nel settore settentrionale del tavoliere di puglia sui depositi del pleistocene medio e superiore hanno fornito nuovi dati sull’evoluzione sedimentaria di questo settore dell’avanfossa dell’appennino meridionale. i depositi registrano l’interazione fra sollevamento regionale e fluttuazioni del livello del mare; il quadro geologico evolutivo che ne risulta è innovativo non solo se confrontato con la cartografia ufficiale alla scala 1:100.000, ma anche rispetto ai dati della letteratura più recente sull’area. i fogli alla scala 1:50.000 (progetto c.a.r.g. – 407 “san bartolomeo”, 396 “san severo” ed il settore nord-occidentale del 408 “foggia”) occupano un’area che si estende dalla catena fino all’avampaese, per l’intero settore settentrionale del tavoliere di puglia; l’estensione areale dell’area investigata ha permesso di valutare con buon dettaglio le variazioni laterali di facies in ogni unità terrazzata. nelle aree di pianura caratterizzate da un minor numero di affioramenti, l’analisi di facies è stata condotta su carotaggi, predisponendo sondaggi ad hoc in aree chiave. gli ambienti deposizionali riconosciuti variano da pianura alluvionale, caratterizzata da depositi di conoide, da prossimale a distale, di piana braided e di area di esondazione, che passano lateralmente a depositi di transizione e/o marini prossimali. i passaggi laterali avvengono repentinamente in quanto le massime distanze fra i depositi alluvionali più prossimali e quelli marini più distali non sono mai maggiori di 20 km. dal punto di vista delle ricostruzioni paleogeografiche, il dettaglio dei dati raccolti permette una migliore definizione delle tappe evolutive sia rispetto ai lavori a scala regionale (ciaranfi et al., 1979; ciaranfi et al., 1983; tropeano et al., 2002) che quelli effettuati in queste aree (ciaranfi & rapisardi, 1977; aucelli et al., 1997). tutte le differenze riscontrate in letteratura fra il tavoliere di puglia e la fossa bradanica meridionale vengono confermate, con un cospicuo incremento nel dettaglio. durante i l sollevamento regionale del pleistocene medio e superiore, nel tavoliere di puglia la sedimentazione è essenzialmente continentale; al contrario nello stesso intervallo di tempo nei settori meridionali dell’avanfossa appenninica (bacino lucano di balduzzi et al., 1982) domina la sedimentazione silicoclastica marina. nel tavoliere di puglia (bacino pugliese di balduzzi et al., 1982) inoltre le unità terrazzate continentali e quelle marine poggiano sempre in erosione su unità marine più antiche, generalmente rappresentate dalle argille subappennine; nella fossa bradanica meridionale è invece stata riconosciuta l’esistenza di depositi marini regressivi in continuità sulle argille subappennine. tali differenze sono da mettere in relazione alla sostanziale diversità nel volume degli apporti in questi due settori di avanfossa, con il tavoliere – perlomeno la porzione qui indagata – che risulta sottoalimentato durante il pleistocene medio e superiore a causa della ridotta estensione dei bacini di alimentazione dei sistemi alluvionali. tale carattere, connesso a cause di tipo tettonico nella strutturazione del settore più esterno del subappennino dauno, si manifesta con maggiore evidenza quando nel pleistocene medio l’attività di un sistema di faglie situato a nord di apricena (aucelli et al., 1997; spalluto & moretti, 2006) provoca la migrazione verso nord-ovest del corso del f. fortore e del suo apparato deltizio (l’unico corso d’acqua con un grande bacino di alimentazione). le scelte cartografiche che sono state operate nel corso dei nuovi rilevamenti carg al 50.000 sono state dettate dal riconoscimento di superfici di inconformità di valenza regionale: i differenti sintemi poggiano su superfici erosive osservabili con grande continuità laterale, seppur poste a differenti quote; anche subsintemi marini e continentali appartenenti ad uno stesso sintema sono separati da superfici di inconformità con 195 paleogeographic evolution of the tavoliere di puglia plain during the middle-late pleistocene. a. in the first part of the middle pleistocene, alluvial fan and braided systems develop already in valleys incised in the argille subappenine unit – asp (and eroding the older regressive marine units too – dr). b. uplift induces a shifting toward east of the coastline (recorded by the deltaic – d and proximal marine m deposits of the colle degli ulivi subsynthem – tvp1). alluvial systems (tvp2) move eastward and erosion continues on the dr and asp units. c. a w-e oriented active fault (located north of the san severo town) causes the formation of a narrow gulf in which proximal marine units (m) deposited (san severo subsynthem tpb1). fortore river is forced to move toward nw. d. at the end of the middle pleistocene, the gulf becomes narrower and proximal marine units (m) sedimented (amendola subsynthem). e. in the late pleistocene, alluvial systems moves eastward following the coastline toward the present day manfredonia gulf. f. present-day geographic picture. evoluzione geologica del settore settentrionale ... caratteri simili. altra osservazione riguarda l’inclinazione delle superfici basali delle unità a limiti inconformi; la variazione graduale nel tempo della pendenza delle superfici basali da angoli maggiori ad angoli via via minori può essere connessa, più che a motivi tettonici, a variazioni nei profili di equilibrio dei corsi d’acqua (modificazioni graduali nel rapporto fra differenza di quota dell’area di alimentazione e livello di base e l’aumento nel tempo della lunghezza dei corsi d’acqua causato dalla regressione). la progressiva formazione delle superfici di inconformità con la contemporanea migrazione laterale delle facies indica che tali superfici sono diacrone. ulteriori analisi saranno richieste per interpretare il significato di queste superfici (e le variazioni registrate nelle successioni sedimentarie) in termini sequenziali. le geometrie (e la successione verticale delle facies) dei depositi marini e quelle delle loro superfici di base nonché i rapporti laterali e verticali con gli associati depositi continentali richiamano il modello di riempimento di valli incise (incised valley infill) proposto da darlymple et al. (1994); dati inediti raccolti recentemente (e tuttora in fase di elaborazione) sulle successioni che si rinvengono nelle valli incise mostrano tuttavia sostanziali differenze rispetto ai modelli noti in letteratura; tali differenze andranno giustificate sulla base della peculiare situazione locale (moderato sollevamento, mancanza di ingenti volumi di apporti sedimentari, ecc.) al fine di associare ogni fase sedimentaria osservata ad uno specifico tratto della curva eustatica. la carenza di datazioni per i depositi descritti, impone infine di attribuire l’evoluzione di questo tratto di fossa bradanica genericamente ad un pleistocene medio e superiore in base a considerazioni di carattere regionale: ciò non consente al momento di associare ogni deposito a specifiche variazioni della curva eustatica. ringraziamenti gli autori desiderano ringraziare sentitamente p. maiorano per le analisi sulle associazioni a foraminiferi e quelle a nannoplankton calcareo e m. tropeano per la lettura della prima bozza del lavoro e le proficue discussioni sul tema. la prima versione del manoscritto è stata sensibilmente migliorata dalla lettura critica di due referee anonimi. bibliografia aucelli p.p.c., cinque a. & robustelli g. (1997) evoluzione quaternaria del tratto di avanfossa appenninica compreso tra larino (campobasso) e apricena (foggia). dati preliminari. il quaternario, 10, 453-460. berger w.h. & jansen e. (1994) mid-pleistocene climate shift: the nansen connection. in johannesen et alii eds. the polar. oceans and their role in the shaping the global environment. agu geophys. monogr., 85, 295-311 balduzzi a., casnedi r., crescenti u. & tonna m. (1982) il plio-pleistocene del sottosuolo del bacino pugliese (avanfossa appenninica). geologica romana, 21, 1-28. boenzi f., caldara m. & pennetta l. (1992) osservazioni stratigrafiche e geomorfologiche nel tratto meridionale della piana costiera del tavoliere di puglia. geogr. fis. dinam. quat., 14, 23-31. bonardi g., d’argenio b. & perrone v. (eds.) (1988) carta geologica dell’appennino meridionale. scala 1:250.000 . cnr/cartografi a selca. roma/firenze. boni a., casnedi r., centamore e., colantoni p., cremonini g., elmi c., monesi a., selli r. & valletta m. (1969) note illustrative alla carta geologica d’italia. f° 155 “san severo”. serv. geol. d’it. roma. caldara m. & pennetta l. (1991) pleistocenic buried abrasion platforms in southeastern“tavoliere” (apulia, southern italy). giornate di studio sul tema “terrazzi marini e linee di costa pleistoceniche”. il quaternario, 4 (2), 303-309. caldara m. & pennetta l. (1993) nuovi dati per la conoscenza geologica e morfologica del tavoliere di puglia. bonifica, 8, 25-42. capuano n., pappafico g. & augelli g. (1996) ricostruzione dei sistemi deposizionali plio-pleistocenici del margine settentrionale dell’avanfossa pugliese. mem. soc. geol. it, 51 (1), 273-293. ciaranfi n., maggiore m., pieri p., rapisardi l., ricchetti g. & walsh n. (1979) considerazioni sulla neotettonica della fossa bradanica. contr. prel. realiz. carta neotettonica d’italia. pubbl. n° 251 del p.f., 73-95, napoli. ciaranfi n. & rapisardi l. (1979) osservazioni preliminari sulla neotettonica dei fogli 155 “san severo”, 163 “lucera”. contr. prel. realiz . carta neotettonica d’italia. pubbl. n° 251 del p.f., 3945, napoli. ciaranfi n, ghisetti f., guida g., iaccarino s., lambiase s., pieri p:, rapisardi l., ricchetti g., torre m., tortorici l: & vezzani l. (1983) carta neotettonica dell’ italia meridionale. pubbl. 515 del p.f. geodinamica. cita m.b., capraro l., ciaranfi n., di stefano e., lirer f., maiorano p., marino m., raffi i., rio d., sprovieri r., stefanelli s. & vai g.b. (2008) the calabrian stage. episodes, 31, 4, 408-419. cita m.b., capraro l., ciaranfi n., di stefano e., marino m., rio d., sprovieri r. & vai g.b. (2006) calabrian and ionian: a proposal for the definition of mediterranean stages for the lower and middle pleistocene. episodes, 29, 2, 107-114. cremonini g., elmi c. & selli r. (1971) note illustrative della c.g. d’it., foglio 156 “s. marco in lamis”. serv. geol. d’it., roma. crostella a. & vezzani l. (1964) la geologia dell’appennino foggiano. boll. soc. geol. it., 83 (1), 121-141. d’alessandro a. & la perna r. (2004) the “cocooned” mytilid amygdalum (bivalvia), palaeontological observations from the upper pliocene. rivista italiana di paleontologia e stratigrafi a, 110 (3), 725-731. dalrymple r.w., boyd r. & zaitlin b.a. (1994) history of research, types and internal organization of incised-valley systems: introduction to the volume. in: r.w. dalrymple, r. boyd and b.a. zaitlin, 196 moretti et al. editors, incised-valley systems: origin and sedimentary sequences, sepm spec. publ. vol. 51 (1994), pp. 3–10. delano smith c. (1978) daunia vetus. terra, vita e mutamenti sulle coste del tavoliere. amm. prov. di capitanata, 249, foggia. doglioni c., mongelli f. & pieri p. (1994) the puglia uplift (se italy). an anomaly in the foreland of the apenninic subduction due to buckling of a thick continental lithosphere. tectonics, 13, 1309-1321. gallicchio s., pieri p., festa e., moretti m. & tropeano m. (2002) caratteri geologici del foglio 407 “san bartolomeo in galdo”. cartografia geologica. bologna, febbraio 2002, 3, 136-139. gibbard p. l., head m. j., walker m. j. c. & s. s. (2010) formal ratification of the quaternary system/period and the pleistocene series/epoch with a base at 2.58 ma. journal of quaternary science, 25 (2) 96-102. jacobacci a., malatesta a., martelli g. & stampanoni g. (1967) note illustrative della carta geologica d’italia alla scala 1:100.000 foglio 163 lucera. 48 pp. maasch k.a. & saltzmann b. (1990) a low-order dynamical model of global climat variability over the full pleistocene. jour. of geoph. res., 95. 1955-1963 merla g., ercoli a. & torre d. (1969) note illustrative della c.g. d’it.: foglio 164 “foggia”. serv. geol. d’it., roma. moccia f. (1993) caratteri geomorfologici di particolare interesse per l’area occidentale del tavoliere. bonifica, 8, 89-94. mudelsee w. & statteger k (1997) exploring the structure of the mid-pleistocene revolution with advance methods of t ime-series analysis . geol. rundschau. 86, 499-511 ori g.g. (1988) facies e geometrie deposizionali dei sedimenti fluviali giornale di geologia, ser.3a, 50/1-2, 39-67. parea g. c. (1986) i terrazzi marini tardo-pleistocenici del fronte della catena appenninica in relazione alla geologia dell’avanfossa adriatica. mem. soc. geol. it., 35, 913-936. ricchetti g. (1965) alcune osservazioni sulla serie della fossa bradanica. le «calcareniti di m. castiglione». «boll. soc. natur. napoli», 74, 243251, napoli. ricchetti g., ciaranfi n., luperto sinni e., mongelli f. & pieri p. (1988) geodinamica ed evoluzione sedimentaria e tettonica dell’avampaese apulo. mem. soc. geol. it., 41, 57-82. rio d., sprovieri r., castradori d. & di stefano e. (1998) the gelasian stage (upper pliocene): a new unit of the global standard chronostratigraphic scale. episodes, 91, 82-87. servizio geologico d'italia (in stampa) foglio 396 "san severo" della carta geologica d'italia alla scala 1:50.000. spalluto l. & moretti m. (2006) evidenze di neotettonica (pliocene medio-pleistocene superiore) nel settore occidentale del promontorio del gargano (italia meridionale). il quaternario, 19(1), 143-154. tropeano m., sabato l. & pieri p. (2002) filling and cannibalization of a foredeep: the bradanic trough (southern italy). in “sediment flux to basins: causes, controls and consequences” (s.j. jones and l.e. frostick, eds.), pp. 55-79. geol. soc. london, spec. publ. 191, london. 197evoluzione geologica del settore settentrionale ... ms. ricevuto il 17 settembre 2009 testo definitivo ricevuto il 6 ottobre 2010 ms. received: september 17, 2009 final text received: october 6, 2010 available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternaryvol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 75 77 middle pleistocene human and animal mobility at isernia la pineta: a strontium and oxygen isotope perspective federico lugli 1,2 , anna cipriani 2,3 , julie arnaud 4 , marta arzarello 4 , giuseppe lembo 4 , renée janssen 5 , hubert vonhof 5 , carlo peretto 4 , stefano benazzi 1,6 1 department of cultural heritage, university of bologna, ravenna, italy 2 department of chemical and geological sciences, university of modena and reggio emilia, modena, italy 3 lamont-doherty earth observatory, columbia university, palisades, new york, usa 4 department of humanities, section of prehistorical and anthropological sciences, university of ferrara, ferrara, italy 5 department of climate geochemistry, max planck institute for chemistry, mainz, germany 6 department of human evolution, max planck institute for evolutionary anthropology, leipzig, germany corresponding author: f. lugli <federico.lugli6@unibo.it> abstract: in this work, we explored the isotopic composition of faunal (rodents, rhinoceros and bison) and human skeletal remains from the middle pleistocene layers of isernia la pineta (molise, italy). we particularly focused on high spatial resolution isotope analyses of tooth enamel by laser ablation mc-icp-ms for strontium isotopes and by micro-drilling sampling for oxygen isotopes. results from bone specimens were compared with the isotope variability of modern plants collected in the area surrounding the site, in a radius of about 30 km. while the human group seems local, macro-mammals show a higher degree of mobility. keywords: isotopes, middle pleistocene, deciduous tooth, strontium isotopes, laser ablation, oxygen isotopes 1. introduction in recent years, the use of isotope ratios (e.g. 87sr/86sr and δ18o) to decrypt past human and animal migratory patterns has been an important tool in archaeological and paleontological research. in particular, the discovery and significance of natural variations in the isotopic composition of strontium in biological and inorganic materials, has made sr isotopes one of the best geochemical indicators for provenance studies (bentley, 2006). as an alkaline earth metal with chemical-physical properties similar to those of calcium, strontium is commonly found in natural calcium carbonate (e.g. shells and speleothems) and phosphate (e.g. bones and teeth). the ratio between the isotopes 87sr and 86sr can be employed as a provenance marker typically deriving from a precise geological area depending on the age and on petrochemical features of the local rocks. thus, sr enters the ecosystem reaching plants and animals, mainly through water, following erosion and weathering of the bedrock. sr is mainly fixed in the hydroxyapatite of teeth and bone tissue substituting calcium, with concentrations ranging between c.a. 50 to 1000 ppm. in this sense, tooth enamel becomes the best target tissue to perform sr isotope analysis. this is because of two different reasons. first, being a ~96% mineralized tissue (mainly hydroxyapatite ca10(po4)6(oh)2), enamel is quite resistant to diagenetic alterations, usually preserving the biogenic isotopic signature of the individuals. second, enamel forms during childhood and does not remodel during the life of the individual, therefore, its sr isotopic composition should reflect the signature of the place where the individual has spent its youth. this makes teeth the perfect target to unravel human/animal migrations (lugli et al., 2017a). similarly, oxygen is fixed within carbonate and phosphate groups of the hydroxyapatite. the δ18o composition of tooth enamel reflects the isotope composition of the body water, which, in turn, varies linearly with the local meteoric water. consequently, the δ18o value of skeletal remains is an important tool the decrypt the palaeoclimatic proxies, but also to track possible movements of an individual between places with different environmental conditions (pellegrini et al., 2011). in this work, we used isotope techniques to explore the mobility patterns of humans and animals from the middle pleistocene layers of isernia la pineta (molise, italy; peretto et al., 2015). in particular, the most ancient human deciduous tooth ever found in italy (~580 ka) years was studied employing the micro-destructivity offered by the laser ablation mc-icp-ms. the mobility of the human was thus compared with macro-mammal (bison and rhinoceros) mobility patterns and with the local bioavailable sr isotope composition obtained from the analysis of modern plants grown in areas away from holocene contaminations and on and micro-mammals from the middle pleistocene layers of the site (i.e. rodents; lugli et al., 2017b). moreover, to get new insights https://doi.org/10.26382/aiqua.2018.aiquaconference into the stephanorhinus hundsheimensis migratory patterns and to unravel possible routes taken by this animal, we measured sr and oxygen isotopes of the outer enamel surface in a high spatially resolved approach. 2. material and methods the 87sr/86sr ratios of the is42 human and of a stephanorhinus hundsheimensis tooth were determined by la-mc-icp-ms technique. we sampled several portions (linear transects) of the external enamel surface, following a cervical-incisal direction (human enamel n = 5; rhino enamel n = 25). sr data were acquired with a double focusing mc-icp-ms neptune™ (thermo fisher scientific), coupled to a 213 nm nd:yag laser ablation system (new wave research™), housed at the centro interdipartimentale grandi strumenti (cigs) of the university of modena and reggio emilia. the detailed protocol is described in lugli et al. (2017a). in order to maximize the ion beam size stability, we chose to use dynamic linear ablation (500 x 100 µm), which provides more precise results compared to static spot ablation. we employed a laser frequency of 10 hz and an energy of ~20 j/cm2. the following masses were collected using nine faraday detectors: 88sr, 87sr, 86.5, 86sr, 85rb, 85.5, 84sr, 83kr, 82kr. a 60 s background signal for each mass was collected before the analysis to correct for kr interferences. the presence of doubly-charged dy, yb and er was negligible, also suggesting a low content of rare earth elements within the enamel tissue. data were acquired in single blocks of 200 cycles, with an integration time of 0.5 s. to correct for the formation of 40ca13p16o and 40ar13p16o, we employed a set of inhouse bioapatite reference materials (a swine tooth, a bovine tooth and a shark tooth) building a calibration curve. the analysis of our human tooth in-house reference material (rocht42) yielded an average (n = 10) la 87sr/86sr ratio of 0.70865 ± 0.00040 (2σ) and an accuracy of 0.005% (16 ppm) compared with the true value obtained by dissolution mc-icp-ms of 0.70864 ± 0.00001 (2se). faunal enamel samples and modern plant specimens were analyzed after chemical dissolution and chromatographic separation of sr. samples preparation follows the protocol presented in lugli et al. (2017a). 510 mg of enamel and about 15 mg of plant ashes were digested in 1 ml of 14n hno3 and re-dissolved in 3n hno3 after evaporation. the sr separation uses columns with a ~300µl volume filled with eichrom sr specresin. sr isotope ratios were determined using the mcicp-ms neptune at the cigs unimore. a [blank/ standard/blank/sample/blank] bracketing sequence was adopted to monitor any instrumental drift. data were normalized through exponential law to a 88sr/86sr ratio of 8.375209. during this analytical session, the standard yielded a 87sr/86sr ratio of 0.71025 ± 0.00002 (2σ; n = 33). the sr ratios were corrected for instrumental bias to a nbs-987 value of 0.71026 ± 0.00002. high resolution (0.5 mm) sampling for stable isotope analysis was done on the outer enamel surface of a s. hundsheimensis tooth specimen (apex-cervix direction), using a micro-drilling system. fifty-eight samples were obtained this way. the δ18o isotope composition was thus determined at the max planck institute for chemistry (mainz, germany) on a thermo v mass spectrometer, equipped with a gasbench ii preparation device and a cold trap. in this configuration, tooth enamel samples of <100 microgram (equivalent of <5 microgram caco3) can be measured with <0.15‰ precision (1sd). 3. results the human tooth yielded an average 87sr/86sr ratio of 0.70914 ±0.00038 (2σ; 5 ablation lines). rodent teeth, analyzed by dissolution mc-icp-ms, showed an 80 lugli f. et al. fig. 1 (a) strontium isotope data from human, fauna and modern plant specimens of the isernia la pineta site and surroundings. (b) high spatial resolution analyses of strontium isotopes and oxygen isotopes of a single s. hundsheimensis tooth. 81 average sr isotope composition of 0.70924 ±0.00013 (2σ; n =16). seven bison teeth yielded 87sr/86sr ratios ranging between 0.70927 and 0.70954 (average 0.70938 ±0.00018; 2σ; n =7). rhinoceros teeth, measured by dissolution mc-icpms, showed an 87sr/86sr ratio ranging from 0.70941 and 0.70979 (average 0.70958 ±0.00030; 2σ; n =9). one rhinoceros tooth was also analyzed by la-mc-icp-ms to explore its intratooth variability, yielding 87sr/86sr ratios ranging between 0.71019 to 0.70956 (0.70982 ±0.00038; 2σ; n = 25). on the same tooth, high resolution oxygen isotope analyses yielded δ18oc (smov) values between 24.6 and 26.6‰. these values were then converted in δ18o phosphate values and in δ18o water values using regression from pellegrini et al (2011) and d’angela & longinelli (1990). 4. discussion and conclusion when compared with micro-mammals and local plants, the human sr isotope composition falls within the supposed local isotopic variability (fig. 1). this suggests that the human group from isernia likely exploited local resources, within a limited supply area (c.a. 10-15 km), similarly to modern hunter-gatherer collectors (lugli et al., 2017b). on the contrary, given that the sr isotope composition of macro-mammals seems affected by a higher radiogenic sr signature, we infer that both rhinos and bisons grazed on a different supply area. we suggest that the higher 87sr/86sr ratio derives from the contamination with volcanic soils and are likely related to seasonal migrations in the south-west direction, toward the fertile grounds of the roccamonfina volcano area (conticelli et al., 2009). the high-resolution isotope analysis of a s. hundsheimensis tooth agrees with this interpretation. in fact, both sr and o isotope ratios show clear fluctuations correlated with the growth of the tooth enamel within a period of ca. 400 days (fig. 1). these variations can be related to seasonal movements between places with different oxygen and sr isotope composition (e.g. from isernia to roccamonfina/albani hills and vice-versa). acknowledgements this project was funded by the european research council (erc) under the european union’s horizon 2020 research and innovation programme (grant agreement no 724046 success awarded to prof. stefano benazzi erc-success.eu). additional funding was provided through the programma giovani ricercatori rita levi montalcini (to ac). references bentley r.a. (2006) strontium isotopes from the earth to the archaeological skeleton: a review. journal of archaeological method and theory, 13, 135187. conticelli s., marchionni s., rosa d., giordano g., boari e., avanzinelli r. (2009) shoshonite and sub-alkaline magmas from an ultrapotassic volcano: sr-nd-pb isotope data on the roccamonfina volcanic rocks, roman magmatic province, southern italy. contribution to mineralogy and petrology, 157, 41-63. d'angela d., longinelli a. (1990) oxygen isotopes in living mammal's bone phosphate: further results. chemical geology, isotope geoscience section, 86, 75-82. lugli f., cipriani a., peretto c., mazzucchelli m., brunelli d. (2017a) in situ high spatial resolution 87sr/86sr ratio determination of two middle pleistocene (ca. 580 ka) stephanorhinus hundsheimensis teeth by la-mc-icp-ms. international journal of mass spectrometry, 412, 38-48. lugli f., cipriani a., arnaud j., arzarello m., peretto c., benazzi s. (2017b) suspected limited mobility of a middle pleistocene woman from southern italy: strontium isotopes of a human deciduous tooth. scientific reports, 7, 8615. pellegrini m., lee thorp j.a., donahue r.e. (2011) exploring the variation of the δ18op and δ18oc relationship in enamel increments. palaeogeography, palaeoclimatology, palaeoecology, 310, 71-83. peretto c., arnaud j., moggi-cecchi j., manzi g., nomade s., pereira a., falguères c., bahain j.j., grimaud-hervé d., berto c., sala b., lembo g., muttillo b., gallotti r., thun hohenstein u., vaccaro c., coltorti m., arzarello m. (2015) a human deciduous tooth and new 40ar/39ar dating results from the middle pleistocene archaeological site of isernia la pineta, southern italy. plos one, 10, e0140091. human and animal mobility at isernia la pineta ms. received: may 7, 2018 final text received: may 19, 2018 82 sess 1_160211.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 gelasian to calabrian onland marine record: three case studies in the mediterranean area angela baldanza 1, roberto bizzarri 2, federico famiani 3, irene luccioni 4 & paolo pino 5 1 dipartimento scienze della terra, università di perugia, perugia 2 via a. capitini, 8-06055 marsciano (pg) 3 via monteverde, 16-06029 valfabbrica (pg) 4 via c. colombo-60021camerano (an) 5 dipartimento scienze della terra-università di messina, messina corresponding author: r. bizzarri <roberto.bizzarri@libero.it> abstract: baldanza a. et al., gelasian to calabrian onland marine record: three case studies in the mediterranean area. (it issn 0394-3356, 2011) neogene to quaternary marine sedimentation along the italian peninsula occurred into physiographical articulated basins and was characterized by a paleoenvironmental diversification, both nearshore and offshore. nevertheless, the nannofossil biostratigraphy allows comparisons in the mediterranean area, also in the case of on-land sections. three case studies are here proposed, testifying the importance of calcareous nannofossils also to correlate on-land sections throughout italian neogene deposits. riassunto: baldanza a. et al., record marino del gelasiano-calabriano su serie a terra: tre casi di studio nell’area mediterranea. (it issn 0394-3356, 2011) la sedimentazione marina lungo la penisola italiana, durante il neogene e il quaternario, ha avuto luogo entro bacini dalla fisiografia articolata e riflette differenze sia in ambiente costiero che distale. tuttavia, la biostratigrafia a nannofossili permette correlazioni nell’area mediterranea, anche nel caso delle successioni a terra. tre situazioni vengono proposte in questa sede, nell'intento di mostrare la fondamentale importanza dei nannofossili calcarei anche nelle correlazioni di successioni a terra di depositi neogenici italiani. key words: nannofossil stratigraphy, mediterranean area, gelasian, calabrian. parole chiave: stratigrafia a nannofossili, mediterraneo, gelasiano, calabriano. the evolution of coastal marine environments along the italian peninsula, throughout the neogene and the quaternary, is related to the late phases of the apennine chain foredeep basin foreland eastward migration, and to the opening of the thyrrenian sea. the pliocene and pleistocene marine successions have been deposited into physiographical articulated basins and are characterized by a paleoenvironmental diversification, taking place on coastal environments as well as on basin deposits. nevertheless, foraminifer and calcareous nannofossil stratigraphy allow to compare deeply different situation in the mediterranean area, also in the case of onland sections: three case studies are here proposed (fig. 1). 1 the western umbria plio-pleistocene marine record, from città della pieve to orvieto (central italy) is characterized by shallow marine deposits, varying from gravel to sand, to clay (ambrosetti et al., 1987; bizzarri, 2006). the evolution of the area among pliocene and pleistocene has been described in terms of two main sedimentary cycles, referable to piacenzian pp. and gelasian pp. santernian, respectively, and separated by the “acquatraversa” stratigraphic gap (ambrosetti et al., 1987; girotti & mancini, 2003; mancini et al., 2004). coastal paleomorphologies varied from rocky coasts to deltaic coasts, to sand and gravel beaches locally fed by fan deltas (bizzarri et al., 2005; bizzarri, 2006, 2007, 2010; bizzarri & baldanza, 2009). the documented facies heteropy is due to lateral subenvironmental variations, inherited from previous subaerial evolution of landscape, and testifies of a complex shoreline articulation. on the other hand, deposits distally homogenize to silty sand (transition to offshore) and clay/silty clay (offshore). analyses on both calcareous nannofossils and foraminifers lead to a stratigraphic review (bizzarri et al., 2004; bizzarri, 2006; bizzarri & baldanza, 2006). the recent documentation of still unknown volcanic events, in the mnn 19b to mnn 19d stratigraphic interval (bizzarri et al., 2003; famiani, 2010; peccerillo et al., in press), represents another fine stratigraphic tool to compare onland sections. 2 the underground camerano town (ancona, central italy) allows to describe a composite sedimentological and stratigraphical section into early pleistocene marine deposits (luccioni, 2007; baldanza et al., 2010b), attributable to the qm-a3 phase (cantalamessa et al., 1986; centamore et al., 1991, 2009; centamore & micarelli, 1997; 17 19 18 centamore & nisio, 2003). deposits are mainly characterized by yellow-brown sand and greygreen clay couplets; in the uppermost and in the middle cave system, matrix-supported gravel horizons also occur. sand-clay couplets are interpreted as carbonatic turbidites (baldanza et al., 2010b). the large clay fragments, matrixsupported gravels probably derive from seismic remobilization of partially lithified deposits along the basin’s flank. deposits suggest the sedimentation in a tectonically active basin, with mixed distal river and stormto seismic-induced carbonatic turbidites deposits; nevertheless, biostratigraphic analyses on nannofossil content allow to refer them to early pleistocene (mnn 19c nannofossil subzone: rio et al., 1990). 3 the north-eastern sicily marine grey-blue clay deposits have been recently re-evaluated and mapped (pino et al., 2007, 2009; triscari et al., 2007; baldanza et al., 2010a), with the aim to better define the stratigraphic range. the nannofossil analyses allow to integrate the local stratigraphic succession (kezirian, 1992; di stefano & lentini, 1995; maccarrone et al., 2000). in the messina province, on the tyrrhenian side of the peloritani mts., the most important clay unit (about 70m thick) has been studied in the venetico and c.da scarano outcrops, and the mnn 19e and mnn 19f subzones have been recovered. other reduced exposures, in the eastern villafranca tirrena area (c.da baronello, massa s. lucia), also document the presence of mnn 19b to mnn 19d subzones. the occurrence of volcanic materials, still in the early-middle pleistocene clay deposits of the tyrrhenian side, is also reported (casella et al. 2006; pino et al., 2007). on the ionian side of sicily, early pleistocene clay deposits are firstly reported in the nearby of giardini naxos (pino et al., 2007; baldanza et al., 2010a). the comparison of the three case study is an example of the large affidability of nannofossils as stratigraphic marker, which confirms the identification, also in the onland sections, of the same nannofossil events as in the mediterraean odp pits, in the same order, and shows the applicability to onland sections of the standard mediterranean neogene nannofossil scales. references ambrosetti, p., carboni m. g., conti m. a., esu d., girotti o., la monica g. b., landini b. & parisi g. (1987) il pliocene ed il pleistocene inferiore del bacino del fiume tevere nell'umbria meridionale. geogr. fis. dinam. quat., 10, 10-33. baldanza a., belfiore c., di bella m., pino p., sabatino g. & triscari m. (2010a) – georisorse per le costruzioni in laterizio di taormina e naxos (sicilia nord-orientale): dati petrochimici e micropaleontologici. atti del vi congresso nazionale di archeometria aiar. baldanza a., bizzarri r. & luccioni i. (2010b) resedimentation evidences in the early pleistocene camerano section (ancona, marches, central italy). rend. online soc. geol. it., 11, 716-717. bizzarri r. (2006) depositi plio-pleistocenici tra la val di chiana e il lago di corbara: caratterizzazione sedimentologica e ricostruzione paleoambientale. ph.d. thesis, perugia university, 408 pp. bizzarri r. (2007) late pliocene-early pleistocene fluvial paleocoasts in western umbria (central italy): facies analysis and sedimentation models. geoitalia epitome, 2, 393-394. bizzarri r. (2010) early pleistocene rocky coasts (orvieto area, western umbria, central italy): facies analysis and sedimentation models. italian journal of geosciences, 129 (2), pp.251-268. bizzarri r. & baldanza a. (2006) – on the meaning of the amphistegina levels in the plio – pleistocene of the orvieto area (central italy). in: coccioni r. & marsili a., (eds), proceedings of the second and third italian meetings on environmental micropaleontology. grzybowski foundation special publication, 11, 13-20. bizzarri r. & baldanza a. (2009) – plio-pleistocene deltaic deposits in the città della pieve area (western umbria, central italy): facies analysis and inferred relations with the south chiana valley fluvial deposits. il quaternario 22 (2), 127-138. bizzarri r., passeri l. & baldanza a. (2005) – rocky coasts, sand and gravel beaches from late pliocene and early pleistocene of the orvieto area (western umbria, central italy). geoitalia epitome, 1, p. 166. bizzarri r., ambrosetti p., argenti p., gatta g.d. & fig. 1, ubication of the study areas: 1= orvieto area; 2= camerano section; 3= north-eastern sicily (messina province). ubicazione delle aree studiate: 1= orvieto; 2= camerano; 3= sicilia nord-orientale (prov. di messina).  a. baldanza et al. 19 ms. received: testo ricevuto il baldanza a. (2003) l’affioramento del caio (lago di corbara, orvieto, italia centrale) nell’ambito dell’evoluzione paleogeografica plio – pleistocenica della valle del tevere: evidenze sedimentologiche e stratigrafiche. il quaternario, 16 (2), 241255. bizzarri r., ambrosetti p., argenti p. & baldanza a. (2004) – il pleistocene inferiore in facies marina nei dintorni di corbara (orvieto, italia centrale): gli affioramenti di camorena e del caio. atti del convegno “la geologia del quaternario in italia: temi emergenti e zone d’ombra” (roma, 16-18 febbraio 2004), p. 100. cantalamessa g., centamore e., chiocchini u., colalongo m.l., micarelli a., nanni t., pasini g., potetti m. & ricci lucchi f. (1986) il pliopleistocene delle marche. in: centamore e. & deiana g. (eds.), la geologia delle marche. studi geol. cam., vol. spec., 61-68. casella s., pino p., rasà r. & tripodo a. (2006) – i livelli di tephra infra-medio pleistocenici affioranti in sicilia nord-orientale tra venetico e roccavaldina. atti del convegno “tefrostratigrafia del quaternario recente tra vulcanologia e scienze del quaternario”, (roma, 21 -23 giugno 2006). centamore e., cantalamessa g., micarelli a., potetti m., berti d., bigi s., morelli c. & ridolfi m. (1991) stratigrafia ed analisi di facies dei depositi del miocene e del pliocene inferiore dell'avanfossa marchigiano-abruzzese e delle zone limitrofe. studi geol. cam., vol. spec. 91 (2), 125-131. centamore e., farabollini p. & angelini s. (2009) guida all’escursione:”geologia e geomorfologia del settore fermano nel bacino periadriatico marchigianoabruzzese”. rendiconti online soc. geol. it., 8, 162168. centamore e. & micarelli a. (1997) – stratigrafia. in: l'ambiente fisico delle marche, geologia, geomorfologia, idrogeologia. selca, firenze, 1-66. centamore e. & nisio s. (2003) significative events in the periadriatic foredeeps evolution (abruzzo-italy). studi geol. cam., vol. spec. 2003 (1), 39-48. di stefano a. & lentini r. (1995) – ricostruzione stratigrafica e significato paleotettonico dei depositi plio -pleistocenici del margine tirrenico tra villafranca tirrena e faro (sicilia nord-orientale). studi geol. cam., vol. spec. 95 (2), 219-237. famiani f. (2010) – il quaternario marino del versante occidentale del monte peglia (umbria sud-occidentale): caratterizzazione sedimentologica e paleoecologica. tesi di laurea inedita, università di perugia, 154 p. girotti o. & mancini m. (2003) plio pleistocene stratigraphy and relations between marine and non marine successions in the middle valley of tiber river (latium, umbria). il quaternario, 16 (1), 89-106. kézirian f. (1992) evolution tectono-sedimentarie post nappes des monts peloritains (sicile, ne). mém. geol. igal, 49, 260p. luccioni i. (2007) geologia ipogea di camerano – storia della città sotto la città. collana: quaderni di storia cameranese, castelfidardo, 115 p. maccarrone m., montanari l. & pino p. (2000) – stratigraphic characters of the miocene in the peloritani mountains (ne sicily). mem. soc. geol. it., 55, 243249. mancini m., girotti o. & cavinato g.p. (2004) – il pliocene ed il quaternario della media valle del tevere (appennino centrale). geol. romana, 37, 175-236. peccerillo a., bizzarri r., baldanza a., petrelli m. & famiani f. (in press) early pleistocene distal pyroclastic-fallout material in continental and marine deposits of western umbria (italy): chemical composition, provenance and correlation potential. il quaternario, 23 (2), 231-236. pino p., baldanza a., belfiore c., di bella m., sabatino g., triscari m. (2007) selected clay units in the messina province (ne sicily): a stratigraphic review. geoitalia epitome, 2, p. 401. pino p., baldanza a., belfiore c., di bella m., sabatino g., triscari m. (2009) georisorse in età classica per le grandi costruzioni in laterizio di naxos e taormina (sicilia nord-orientale). vi congresso nazionale di archeometria aiar 2009, ravenna. rio d., raffi i. & villa g. (1990) pliocene-pleistocene calcareous nannofossil distribution patterns in the western mediterranean. in: kastens k. & mascle j. (eds.), proc. odp science results, 107, 513-533. triscari m., baldanza a., belfiore c., di bella m., pino p., sabatino g., tigano g. (2007) clay units in ne sicily: an integrated map and database finalized to archaeometric provenance studies. geoitalia epitome, 2, p. 469. gelasian to calabrian onland marine record: ... january 14, 2011 14 gennaio 2011 amq 32(1) 73-86 zanchetta et al + ring.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 32 (1), 2019, 73 86 stable isotope composition of fossil ahermatypic coral cladocora caespitosa (l.) from pleistocene raised marine terraces of the livorno area (central italy) giovanni zanchetta 1, monica bini 1,2, paolo montagna 3, eleonora regattieri 1,4, luca ragaini 1, simone da prato 4, alessandro ciampalini 5, luigi dallai 4, gabriello leone 1 1dipartimento di scienze della terra, pisa, italy 2istituto nazionale di geofisica e vulcanologia, rome, italy 3ismar-cnr, u.o.s. bologna, bologna, italy 4igg-cnr, pisa, italy 5gruppo archeologico e paleontologico livornese, museo di storia naturale del mediterraneo, livorno, italy. corresponding authors: g. zanchetta <zanchetta@dst.unipi.it> abstract: the livorno coastal area (coastal tuscany) preserves evidences of several raised marine terraces. stratigraphically they have been correlated with mis 5e, 9c and mis 11 sea-level high stands. however, no direct dating have been performed so far. thanks of new findings of fossil specimens of ahermatypic coral of cladocora caespitosa in the terraced units correlated to mis 5e (“terrazzo di livorno”) and mis 11 (“terrazzo della fattoria pianacce”) we attempted direct dating using the u/th technique. moreover, stable isotopes (oxygen and carbon) were used for attempting environmental reconstruction. dating support the correlation of the “terrazzo di livorno” unit with the mis 5e but are inconsistent for the older unit indicating diagenetic umobilization. oxygen stable isotopes suggest warmer condition for the mis 5e and mis 11 compared to modern conditions, even if the indetermination on the water isotopic composition of past interglacial (i.e. ice volume) hampers our capacity to quantify this values. keywords: raised marine terraces, stable isotopes, cladocora caespitosa, u/th dating, livorno.   1. introduction raised beaches deposits represent an invaluable tools for documenting and reconstructing past relative sea level oscillations (e.g., bloom et al., 1974; hearty et al., 2007; olson and hearty, 2009; zanchetta et al., 2012, 2014; bini et al., 2017, 2018; boretto et al., 2017), coastal tectonic activity (e.g., belluomini et al., 2002; nisi et al., 2003; ferranti et al., 2006; pedoja et al., 2011), and climate condition at time of their formation using paleontological and geochemical data (leone and rosselli, 1995; vesica et al., 2000; aguirre et al., 2002, 2006). the mediterranean coast preserves important succession of past marine highstands, the most popular of which are the so-called “tyrrhenian” deposits or terraces (e.g., hearty et al, 1986; belluomini et al., 2002; mauz. 1999; vesica et al., 2000; jeoudi et al., 2003), which have been mostly related to the marine isotope stage (mis) 5e sea level highstand (e.g., ferranti et al., 2006; stocchi et al., 2018). coastal tuscany (central italy) does not make exception, and in fact it preserves important succession of quaternary raised beaches (e.g., federici and mazzanti, 1995; mauz, 1999; boretto et al., 2017; sarti et al., 2017). in particular in the livorno coastal area (fig. 1) there are several evidences of raised terraces older than mis 5e (malatesta, 1942; barsotti et al., 1974; boschian et al., 2006; zanchetta et al., 2006). in this paper, we attempt for the first time to dating these terraces using u/th method on cladocora caespitosa from raised units correlated from mis5e to mis11. we also perform stable isotope (carbon and oxygen) analyses on the same corals, to characterize the marine environment. the isotopic data were compared with samples of modern specimens and samples collected from lower pleistocene deposits outcropping in the area. part of the data were obtained in previous studies conducted in collaboration with f.p. bonadonna and never published before. in the last years c. caespitosa has emerged as a powerful tool to investigate the climatic evolution of the mediterranean sea from annualto-sub-annual resolution using growth rate (peirano et al., 2004), trace elements (silenzi et al., 2005; montagna et al., 2007; royle et al., 2015b) and stable isotopes (silenzi et al., 2005; royle et al., 2015a). this calls for a reappraisal of the successions outcropping in the coastal tuscany also for the concerns related to the present “global warming” and its framing in the natural variability within past interglacial not experiencing human impact.   https://doi.org/10.26382/amq.2019.12 74 zanchetta g. et al. 2. geological and geomorphological setting the livorno area represents a tectonic high, which has shown tendency to a slow uplift during the late quaternary (nisi et al., 2003; zanchetta et al., 2004, 2006), estimated to be ca. 0.1 mm/yr by nisi et al. (2003). this tectonic regime has produced a succession of raised marine terraces (fig. 1), the lowest of which is a polycyclic marine terrace knows in literature as “terrazzo di livorno” or “terrazzo ii” (barsotti et al., 1974; federici and mazzanti, 1995). at the base of the terrace succession, there is a coastal marine unit for which stratigraphy, paleontological assemblages and regional correlations with successions dated using optical stimulate luminescence (osl) and aminostratigraphy support a chronological framing within the mis 5e highstand (hearty et al., 1986; mauz, 1999; nisi et al., 2003; sarti et al., 2017). few meters higher than the “terrazzo di livorno” there is a poorly expressed morphological unit (the so-called “terrazzo di salviano” of barsotti et al., 1974), whose marine origin is debated (malatesta, 1942, barsotti et al., 1974; boschian et al., 2006). revision of borehole data and surficial stratigraphy, however, allowed to define the basal part of this morphological unit as still formed by marine coastal deposits (bossio et al., 2008), representing an older and distinct unit from “terrazzo ii”. the age of the deposit of this unit is uncertain, but reasonably related to mis 9c highstand (zanchetta et al., 2006). the highest morphological unit is represented by a tilted surface ranging from ca. 120 m to 20 m a.s.l., named “terrazzo della fattoria pianacce” (barsotti et al., 1974), or “terrazzo i” (federici and mazzanti, 1995). it is discontinuously covered by coastal deposits (i.e. conglomerati di villa umberto i unit, barsotti et al., 1974), which attest the marine origin of the unit (boschian et al., 2006). in the northern edge the surface, this terrace is covered by a fluvial to a transitional unit locally named poggio ai lecci formation (barsotti et al., 1974, marroni et al., 1990). according to zanchetta et al. (1998, 2006) the poggio ai lecci formation (specifically the section described by barsotti et al., 1974) inland is the equivalent of the san romano formation outcropping eastward along the arno valley. figure 2 shows the relationships of different stratigraphic and morphostratigraphic units of the livorno area. the upper part of the san romano formation contains a thick tephra layers dated using fission track (ft) method to 480±50 ka (bigazzi et al., 1994, 2000; marcolini et al., 2003), and chemically correlated with the early plinian activity of vico volcano and specifically with largest eruptions named vico α and β (cioni et al., 1987) and 40ar/39ar dated at ca. 420 ka and ca. 403 ka (barberi et al., 1994), respectively. recently, tephra with similar composition, equally associated to the early vico activity, have been found in lake successions of the central mediterranean area, where act as important tephrostratigrphic markers for the mis 11 paleoclimatic records (regattieri et al., 2016; kousis et al., 2018). considering the large age uncertainty of ft dating, the 40ar/39ar age or that deriving from the climatostratigraphic position of the equivalent distal tephra in lake ohrid high resolution record (kousis et al., 2018) should be assumed as the best age for this layer. this allows correlating this unit with the mis 11 (marcolini et al., 2003). for the presence of the mentioned tephra and the correlations proposed, it is reasonable to assume that the “terrazzo della fattoria pianacce” unit was modelled during the mis 11 highstand (i.e., mis 11c, railsback et al., 2015), whose the san romano formation is the inland continental equivalent (fig. 2). recently, two new geological sections containing marine fossil remains have been discovered by the collaborators of the livorno museum in the “terrazzo di livorno” and over the “terrazzo della fattoria pianacce”. detailed stratigraphic and the paleontological description of these two news section will be the focus of a different publication and only the general stratigraphy is reported here. both sections contained remains of the coral fig. 1 upper panel: geology of the area (after barsotti et al., 1974; lazzarotto et al., 1990; marroni et al., 1990); 1 urbanized area; 2) recent alluvial deposits; 3) deposits related to “terrazzo di livorno”; 4) deposits related to “terrazzo di salviano”; 5) deposits related to “terrazzo della fattoria pianaccie”; 6) casa poggio ai lecci formation; 7) rocky substratum. see also figure 2 for the stratigraphic relations. lower panel: topographic profile of the area obtained from dtm lidar of the mattm (ministero dell'ambiente per la tutela del territorio e del mare, http://www.pcn.minambiente.it/mattm/procedurarichiesta-dati-lidar-e-interferometrici-ps). 75 stable isotope composition of cladocora caespitosa (l.) from pleistocene raised marine terraces cladocora caespitosa, which gave the opportunity to tempt a direct dating using the u/th, and to perform a preliminary isotopic study for paleoclimatic purposes. 3. fossil distribution, biology and ecology of cladocora caespitosa c. caespitosa is a zooxanthellate and colonial scleractinian species essentially endemic of the mediterranean basin (very few records are from adjacent parts of the eastern atlantic ocean, i.e. morocco and portugal) and it is the sole coral retained as a remnant of the pre-pliocene mediterranean reefs (chefaoui et al., 2017). large fossil c. caespitosa formations have been dated since the late pliocene and it seems to be much flourished in warmer climatic phases of the pliocene and pleistocene when large bioconstructions have been erected in both the eastern and western mediterranean sea (peirano et al., 2004). the extant distribution of c. caespitosa colonies has decreased compared with the fossil one but the causes of this reduction are not fully understood being generically associated with environmentally changes (kersting and linares, 2012). today this species forms still extensive banks mainly near the tunisian coast, ne spain, in the aegean, ligurian and adriatic seas (vertino et al., 2014) but separate colonies in medium or low densities irregularly cover the entire mediterranean coasts (chefaoui et al., 2017). c. caespitosa is a versatile species found in a wide variety of environments, from very shallow waters to no more than 40-50 m in depth because of its photophilous character due to the presence of symbiontic algae. for this reason, it has not been found in dark enclaves but indirect and diffuse light is sufficient to ensure the existence of the zooxanthellae in these conditions (hoogenboom et al., 2010). this coral may live on hard fig. 2 simplified stratigraphic relationship of the livorno area discussed in the text (modified after zanchetta et al., 2006). casa poggio ai lecci is considered the equivalent of the san romano formation (zanchetta et al., 1998) containing a tephra which allow a correlation with the mis11. 1) rocky substratum; 2) gravels; 3) conglomerates; 4) marine sands and gravels; 5) continental fine grained alluvial deposits; 6) cemented sands (“panchina”). and soft bottoms both exposed to strong currents and in sheltered places (bellan-santini et al., 2002). in terms of sedimentation rate, high values are potentially detrimental for symbiont-bearing corals due to the lowering of photosynthetic production and the obstruction/burial of the polyps (kruzic and benkovic, 2008; lokier et al., 2009; peirano et al., 2009). however, c. caespitosa is tolerant to high input of fines since its polyps are proficient in removing small particles from their oral disk (peirano et al., 2004; kruzic and benkovic, 2008). the occurrence of c. caespitosa in mediterranean waters with mean winter sst (sea surface temperature) above 12°c suggest that low sst limits its overall distribution. chefaoui et al. (2017) found that this coral needs higher sst than the mean conditions, both in summer and in winter, to form large buildups: over 20°c in the summer and over 15°c in the winter (see tab. 2 and fig. 3 in chefaoui et al. (2017) for sst mean and range values). these data appear consistent with those of montagna et al. (2007) who affirm that the growth of this species ceases below 14-16°c. on the other hand the correspondence between the largest c. caespitosa bioconstructions and the warmer plio-pleistocene phases seems somehow contradictory to the mortality events of this coral in the last decades attributed to prolonged periods of elevated water temperatures (rodolfometalpa et al., 2000; 2005; kersting et al., 2013; kruzic et al., 2016 among others). different results on c. caespitosa thermal tolerance among acquarium and in situ experiments suggest that other factor may act together with temperature (kersting et al., 2013; chefaoui et al., 2017) but further investigations are clearly required to clarify this point. 4. material and methods 4.1. u/th dating three small fragments were extracted from the skeleton of c. caespitosa samples from cantiere orlando (n=1) and lazzaretto (n=2) and were analysed for uranium and thorium isotopes at the laboratoire des sciences du climat et de l'environnement (lsce, gifsur-yvette, france), following a well-established protocol (pons-branchu et al., 2014). briefly, the samples were mechanically cleaned using a dental drill with diamond-encrusted blades to remove any visible contamination, and finally crushed into a coarse-grained powder with an agate mortar and pestle. an aliquot (~20 mg) of each sample was used for x-ray diffraction analysis (xrd) to identify the bulk mineralogy. the rest (~100150 mg) was transferred to acid cleaned teflon beakers, ultrasonicated in milliq water, leached with 0.1 n hcl for ~15 s and rinsed twice with milliq water to remove any residual contaminants. the cleaned coral carbonate samples were completely dissolved in 3-4 ml dilute (~10%) hcl (optima-grade) and mixed with an internal triple spike with known concentrations of 229th, 233u and 236u, calibrated against a harwell uraninite solution (hu-1) assumed to be at secular equilibrium. the solutions were evaporated to dryness at 70°c and redissolved in 3 n hno3. uranium and thorium were extracted using eichrom uteva ion exchange chromatography and prefilter resins. the isotopes of uranium and thorium were analysed by standard-sample bracketing using a thermo scientifictm neptuneplus mc-icpms fitted with an aridus ii desolvating system (full details of the analytical method are reported in pons-branchu et al. 2014). the 230th/u ages were calculated from measured atomic ratios through iterative age estimation (ludwig and titterington, 1994), using the 230th, 234u and 238u decay constants of cheng et al. (2013). due to the elevated initial δ234u values, the ages were tentatively corrected using the open-system model of thompson et al. (2003) and the present-day seawater δ234u of 145‰ (chutcharavan et al., 2018). no correction was applied for the non-radiogenic 230th fraction. table 1 shows the results. 4.2. x-ray diffraction analysis the three samples were crushed into a fine powder with a mortar and pestle and the powder was mounted on a silicon zero background sample holder. the x-ray powder diffraction data were recorded on a panalytical θ -θ diffractometer at the department of geosciences of the university of padova (italy). the program high score plus was used for phase identification and quantitative analysis by rietveld refinement (rietveld, 1967). refined parameters were scale factors, zero-shift, background, lattice constants, and profile parameters 76 fig. 3 stratigraphy of the a) cantiere orlando, b) lazzaretto sections. see the text for the explanation of lithostratigraphic units (lu). zanchetta g. et al. 77 tab 1 result of the u/th dating.   δ234um = {[(234u/238u)sample/( 234u/238u)eq]-1} x 1000, where (234u/238u)sample is the measured atomic ratio and (234u/238u)eq is the atomic ratio at secular equilibrium. δ234u(initial) is the initial value and is calculated by the equation: δ234u(0) = δ234umeas exp(), where t is the age in years and  is the decay constant for 234u (cheng et al., 2013). dr. w. thompson kindly provided the excel spreadsheet to calculate open-system ages. arag (%) and calc (%) are percentage of aragonite and calcite obtained by x-ray diffraction. tab 2 stable isotope (oxygen and carbon) data from the livorno area. stable isotope composition of cladocora caespitosa (l.) from pleistocene raised marine terraces (gaussian and lorentzian coefficients). 4.3. stable isotopes analyses other samples of c. caespitosa were soaked in distilled water plus 30% h2o2, and cleaned in an ultrasonic bath to remove contaminants. thereafter, the shells were crushed in agate mortar and homogenized. stable isotope analyses were performed at the stable isotope laboratory of the institute of geosciences and earth resources of the italian national research council (igg-cnr, pisa, italy) with a gas bench ii (thermo scientific) coupled to a delta xp irms (finnigan). about 0.15 mg of carbonate was dissolved in h3po4 (100%), for 1 h at 70°c in a sealed vial flushed with helium. results were determined relative to the vienna pee dee belemnite (vpdb) international standard. sample results were corrected using the international standard nbs-19 and a set of 3 internal standards previously calibrated using the international standards nbs -18 and nbs-19). analytical uncertainties for replicated analyses of δ18o and δ13c were 0.17‰ and 0.15‰, respectively. table 2 shows the stable isotope results. 5. results and discussion 5.1. new stratigraphic data a synthetic description of the cantiere orlando and lazzeretto sections (fig. 3) is reported below. cantiere orlando in the outcrop is possible to recognize five different lithostratigraphic units (lu, fig. 3). from the bottom: lu1: massive gray sands to silty sands rich in shallow marine fossils, which can be correlated to lower pleistocene (calabrian) according to the stratigraphic reconstruction from boreholes in the area (dall’antonia et al., 2004) and fossil content. lu2: well-sorted beige-brown sands, with oxidized layers that contain decarbonated bivalves. the lower boundary is sharp and erosive. the presence of the ostracod aurila puncticruciata, which is restricted to the interval of the late lower pleistocene (ruggieri, 1980), typical of the fauna of local “sicilian” transgressive deposits (dall’antonia et al., 2004), allows to identify a second short sedimentary cycle corresponding to the “sicilian”. lu3: fluvial polygenic gravels (mostly carbonates) in sandy matrix (lu3), upward more clayey. this corresponds to the continental unit of korea formation (zanchetta et al., 2006) of upper middle pleistocene. lu4: the lu3 upward passes to lu4, formed by ochreorange sandy silts and silty sands, with sand concretions and scarce marine microfauna, indicating nearshore environment. lu5: it lies over lu4 with an erosive surface and consists of a calcarenitic layer rich in marine fossil. in lu4 remains of cladocora caespitosa are frequent. this unit correspond to “panchina i” of federici and mazzanti (1995). lu6: this unit consists of clayey silts green-black in color, and contains abundant wood fragments and peat layers. it is almost barren of fossil remains with few cuticles of oogonium, indicating that it represents a swampy environment. lu7: it consists of well-sorted red-brown loose sands of probable aeolian origin representing “panchina ii” of federici and mazzanti (1995). lu8: it consists of anthropogenic accumulation of briks fragments and reworked material lu3 to lu7 is the typical succession described for the “terrazzo di livorno” starting from the lowstand, fluvial deposits of the korea formation (mis 6 to mis 5/6 transition, zanchetta et al., 2006) followed by the lu3-lu4 representing the typical deposit of the mis 5e highstand in the area (boschian et al., 2006). lazzeretto section the section outcrops along a small fluvial incision. four main lithostratigraphic unit can be distinguished (fig. 3): lu1: rocky substratum represented by the argillitic antignano formation (marroni et al., 1990). lu2: whitish calcarenites with thin lenses of gravels and marine fossil remains. lu3: bluish sands to silty sands with abundant marine fossil remains with frequent remains of c. caespitosa. in the upper part of the visible outcrop lu3 shows calcarenitic lenses with sparce granules and gravels. lu4 weathered colluvial fine sand to silt deposits. lu2 and lu3 represents the marine sediment of the “terrazzo della fattoria pianacce”. for comparison with fossil samples, a small living colony of c. caespitosa was collected near the “secche della meloria” shoal, off livorno coast by a collaborator of the livorno museum. 5.2. chronology table 1 shows results of u concentration, activity ratios and 230th/234u ages of the coral fragments analysed in the present study. the three samples have 238u concentration of 2.6 ppm, which is within the reported range of the modern c. caespitosa specimens (montagna et al., 2007). the back-calculated δ234u values (δ234uinitial) range from 169±2‰ for sample “lazzaretto” to 181.2±2.4‰ for “cantiere orlando” one. those values are significantly above the tolerance intervals recommended for marine samples (e.g. 145±8‰, chutcharavan et al., 2018), suggesting that the analysed coral samples have behaved as open-systems. we decided to apply the model by thompson et al. (2003) to correct for open-system behavior, even though we acknowledge that the application of the model to single analyses of corals can be somehow misleading. the corrected ages are of 143.7±1.4 ka for “cantiere orlando” sample, and 111±1 ka and 106.8±0.7 ka for “lazzaretto” sample. the xrd analyses reveal a very high amount of calcite (33%) for the “cantiere orlando” sample, which points to a diagenetic alteration of the primary coral aragonite that most likely biased the calculated u/th age of the sample. however, this age is still in agreement (even if too old) with the unequivocal correlation for these level with the mis5e (boschian et al., 2006). despite the minor degrees of aragonite-calcite 78 zanchetta g. et al. fig. 4 shows the data against presumed ages. for comparison, we have inserted the unpublished data of c. caespitosa collected in different outcrops of lower pleistocene age in the “colline pisane” hills (table 3), just north-east of livorno, analysed in the past by students of prof. bonadonna during master thesis (tani, 1996; gazzerro, 1996). there is a quite detailed information on the stratigraphic position of these samples, even if the original samples are lost and most of the outcrops quoted in the text are not visible anymore. the stratigraphic data permit to confirm that all the samples have been collected in the “morrona formation” (marroni et al., 1990; boschian et al., 2006) or stratigraphically lateral equivalents (zanchetta, 1995; zanchetta and mazza, 1996; sarti et al., 2008). the age of the formation is not well-constrained. however, paleomagnetic and paleontological evidences indicate a “calabrian” (lower pleistocene) and possibly late gelasian (upper pliocene) age, indicating a chronological range from ca. 2 to 1.4 ma (ambrosetti et al., 1975; bedini et al., 1981; zanchetta and mazza, 1996; boschian et al., 2006 and references therein). figure 3 also shows the isotopic data from a sample of living colony in the continental shelf of the ligurian sea collected by silenzi et al. (2005). according to silenzi et al. (2005), isotope data of this sample are considered to cover a period of 96 yrs (1906-2000 ad), with annual resolution (assessed through band-counting). on the other hand, our fossil and living bulk samples represent an unknown period of growth, probably lasting several years (samples crushed for stable isotopes were several mm-long), therefore representing the average isotope composition of different years. aragonite forms skeleton of living samples of c. caespitosa (e.g. silenzi et al., 2005). samples from the “cantiere orlando” section show a partial recrystallization from aragonite to calcite, with the analyzed sample for xrd showing up to ca. 33% of calcite. samples from “lazzaretto” section show almost completely preserved (2% calcite) aragonite compositions. for the pleistocene samples, the data reported in tani (1996) show that samples analyzed for xrd showed an almost pure (calcite below the detection limits, which would have transformation for the lazzaretto (2%) sample the age completely disagrees with the morphological and stratigraphic position of “terrazzo della fattoria pianacce”, confirming a diagenetic alteration for the u/th system, possibly related to a recent uptake of u. the different sediment (relatively coarse, well-sorted and cemented sand for “panchina i” of cantiere orlando section, more fine grained and uncemented for lazzeretto section) can justify the different degree of aragonite-calcite transformation in these two sites, being higher in cantiere orlando section, where diagenesis appear more evident for the cementation of the sand deposits. 5.3. stable isotopes table 2 shows the isotopic data. fig. 3 shows the biplot diagram of δ13c vs δ18o isotopic values, whereas 79 fig. 4 diagram δ13c and δ18o of samples discussed in the text. tab. 3 stable isotope data on lower pleistocene from colline pisane. stable isotope composition of cladocora caespitosa (l.) from pleistocene raised marine terraces been ca. 1-2%, for what it is possible to understand for the method used) aragonitic composition. for most of the samples, we can assume a substantial preservation of the pristine isotope signal, even if some samples can have had experienced a partial reset as effect of recrystallization, as evident in the sample from “terrazzo di livorno” unit. we note that δ18o values of living specimen from livorno are clearly more 18o-enriched compared to older samples. instead, there is substantial overlaps between mis 5e and mis 11 oxygen values (fig. 4, 5). lower pleistocene samples (table 3, fig. 4, 5)) show the largest range of δ18o values, overlapping those of the mis5e and mis11, but not the modern (fig. 4, 5). the data from silenzi et al. (2005) show a δ18o range of values, which overlap with most the mis 5e and mis 11 values and partially with those of the lower pleistocene, but not those of living c. caespitosa collected from livorno area (fig. 4). δ13c values show almost overlapping values from modern to mis 11. the lower pleistocene samples show a very large range of values and, on average, appear 13c-depleted compared to living, mis5e and mis11 samples. oxygen isotope composition of marine carbonates depends on temperature of precipitation and isotopic composition of seawater (epstein et al., 1953), plus different kinetic and biological effects related to physiology of different species (e.g. wefer and berger, 1991) and the eventual presence of symbiotic photosynthetic organisms. corals are known to show various deviation 80 from isotopic equilibrium condition (both for oxygen and for carbon) owing to different processes (e.g. mcconnaughey, 1989a, 2003; adkins et al., 2003). despite this complexity, δ18o is one of the most used proxy for reconstruction of past changes in sst and salinity (e.g. tudhope et al., 1995; felis et al., 2000; rimbu et al., 2003). data collected from living species in the ligurian sea by silenzi et al. (2005) clearly show that at higher temperature the carbonate is 18o-depleted and at lower temperature the carbonate is 18o-enriched, as predicted by the empirical and experimental determination of the dependence of oxygen isotope fractionation factors in relation to the temperature changes (e.g. grossman and ku, 1986; patterson et al., 1993; kim and o’neil, 1997). however, silenzi et al. (2005) noted that a statistically significant correlation could not be found between available sea surface temperature (sst) and δ18o, suggesting that, apart from temperature, a change in salinity (i.e. δ18o of seawater) may have occurred during years. so this prevent to have a robust equation to calculate, at least, sst relative variability, even if a values of -0.17‰/°c was found, very close to what usually expected for biogenic carbonates and inorganic precipitates, showing a value close to ca. -0.2‰/°c (e.g. dettman et al., 1999) for the range of ambient temperatures. δ18o average value from silenzi et al. (2005) is 1.44±0.31‰, which is lower than average values of bulk samples from the coral colony in the meloria shoal (-0.57±0.06‰). this may suggest for them lower temperature of growth and/or higher local salinity. the c. fig. 5 diagrams showing δ18o vs time and δ13c vs time. zanchetta g. et al. caespitosa precipitates two bands per year, a highdensity band forming during periods of lower temperature and lower light intensity, and a low-density band corresponding to high temperature and high light intensity (peirano et al., 1999). for obtaining data close to average sst, considering water stratification, silenzi et al. (2005) selected only high-density bands, and this may have produced a further bias between the data collected in the northern ligurian sea and meloria shoal bulk data (in particular high-density bands may have formed during phases of lower salinity and then lower δ18o of seawater). however, data from northern ligurian sea are of particular relevance because they give a range of values associated with a range of sst of ca. 4°c (estimated using sr/ca calibrated against measured temperature from 1982-2000). even if salinity variability is unknown, mis5e (average δ18o: -1.93±0,38‰) and mis11 (average δ18o: -2.02 0,18‰) appear to compare with the lower range of δ18o values of northern ligurian sea and are more 18o-depleted than the average values of coral from livorno. this suggests that past interglacials have an average temperature some degrees higher than present day. this seems to fit well with general evidences of higher temperature during the last interglacial (e.g. clark and huybers, 2009). however, ice volume during the mis5e and mis11 interglacials would not be identical to present interglacial conditions. indeed, higher eustatic sea level during the last interglacial is well known globally (dutton and lambeck 2012; bini et al., 2018), and it is supposed for mis 11, even if the eustatic component of this period is still debated (e.g. olson and hearty, 2009; bowen, 2010). recent estimations using sst record to calculate past δ18o of sea water (i.e. the most direct proxy of ice volume) from planktonic δ18o record (shakun et al., 2015), show that the mis5e has lower δ18o of sea water (ca. -0.45‰), whereas mis 11 has higher values (ca. -0.30‰). in the same reconstruction, average global sst seems to be higher for mis 5e (ca. 1°c) than for mis 11. higher temperature and lower ice volume (i.e., lower δ18o value of seawater), explain well the apparent similarity of these two interglacials, in the benthic isotopic stack of lisieki and raymo (2005) compared to holocene. this also would explain the evident similar values found in mis5e and mis11 samples of c. caespitosa from raised marine terraces of livorno, and the difference with the living specimens. considering the global lower δ18o value of seawater during mis 5e and mis 11 reported by shakun et al. (2015), there is still ca. 1‰ of residua in the δ18o values from livorno, which should be accounted for higher temperature and eventual lower salinity of local seawater. this is in agreement with the results form speleothem from apuan alps (drysdale et al., 2005; regattieri et al., 2014;, tzedakis et al., 2019) showing increased rainfall during mis5e over central italy, but in particular with lower salinity of the ligurian sea reconstructed by toucanne et al. (2015), during mis5e and mis11c, in response to the intensification of mediterranean storm track along the northern mediterranean borderlands in autumn/winter in correspondence of deposition of sapropels in the eastern mediterranean. then, living specimens from livorno suggest then cooler seawater, higher ice volume and higher salinity conditions compared to mis5e and mis11, in a combination, however, difficult to be disentangled from our data. lower pleistocene samples show a large δ18o range partially overlapping mi5e, mis11 and the lower values (i.e. presumably the warmer counterpart) of living samples from northern ligurian sea. this suggests that samples from different localities all included in the lower pleistocene captured different glacial/interglacial cycles characterized by different temperature and ice volume. the presence of two clusters of δ18o values for samples originated by different localities (fig. 4) may suggest the presence of two specific intervals containing c. caespitosa, an eventuality that future stratigraphic research in the area should confirm, but suggested by tani (1999). possibly, the lowest values may represent a particularly prominent interglacial and according to lisieki and raymo (2005) stacked isotopic records we speculate that this would be mis 42. the thickness of the morrona formation (more than 100 m), indicate a clear deposition within a subsiding basin (boschian et al., 2006), which indicates that this succession has recorded several glacial to interglacial cycles, which potentially can be disentangled and used as important archives for reconstruction of past coastal condition. however, the apparently low δ18o values of some samples accompanied by lower δ13c values may also suggest that, despite the relatively well-preserved aspect, the isotopic composition may have been partially resetted by diagenetic meteoric fluids. meteoric waters often originate percolating waters, which have lower δ18o and δ13c, compared to marine waters, so the final isotopic composition of altered carbonate would be the results of different effects, including water/rock ratio, temperature and isotopic composition of diagenetic fluids (lohmann, 1988). we have to note that for samples having preserved mostly the aragonite composition this effect would be minor because during diagenesis aragonite is highly prone to dissolution, followed by precipitation of more stable low-mg calcite (e.g. brand, 1989). however, this cannot verified anymore for all samples from lower pleistocene, even if the samples analysed by xrd reported in tani (1999) suggest aragonite preservation. the range of δ13c values of living specimen from northern ligurian sea (from ca. 3.4 to -5.6‰) covers almost all the values of fossil samples (from -2.7 to -5.9‰), suggesting that these values are usual and no necessarily suspect of alteration (as indicated by most xrd). therefore, we believe that most of the data represent genuine pristine isotope composition of aragonitic coral, with some doubt for more altered samples from panchina i, which shows significant amount of calcite from xrd. however, these samples are not located at the lower end of the range of isotope values and possibly still retain most of the original stable isotope signal. the large spread of δ13c values from lower pleistocene corals (covering most of the interval of annual data from ligurian sea) is then more related to changes in isotopic composition of the dissolved inorganic carbon (dic) of local water and to effects linked to metabolic and kinetic processes (i.e. the so-called vital effect, e.g. mcconnaughey, 1989ab), which is particularly pronounced in corals (wefer and berger, 1991). as 81 stable isotope composition of cladocora caespitosa (l.) from pleistocene raised marine terraces suming that metabolic and kinetic effects have a substantial similar influence on δ13c values between present and past condition, it seems that the carbon isotope composition of the dic should have remained over a range of values substantially compatible to present day conditions. even if the lower pleistocene may indicate a tendency to have average values 13c-depleted compared to younger samples (fig. 4). 6. concluding remarks despite, our attempt to use c. caespitosa to date directly (and for the first time) some terraced units of the livorno area failed, due to diagenetic alteration of the analysed specimens, the data presented in this work seems to suggest that c. caespitosa would have retained unaltered the 13c/12c and 18o/16o ratios and thus can be useful for the reconstruction of past coastal water condition during different interglacial cycles. compared to present condition, mis5e and mis11c seems to have been characterized by higher temperature accompanied by lower salinity, in agreement with regional paleoclimatic data. this preliminary attempt also shows the potential to expand this investigation to the lower pleistocene. future researches should also be implemented by trace element analyses, and by stable isotope analyses performed at annual to sub-annual resolution. acknowledgements this paper is dedicated to the memory of antonello bonadonna, for his dedication to the quaternary geology and the paleontology, his important contributions to geology and paleontology will always be remembered. gz wants to dedicate this paper to his unforgettable master and his political passion. this paper has been founded by fondi di ateneo, university of pisa (g. zanchetta). we thank the ministero dell'ambiente per la tutela del territorio e del mare for the use of the dtm lidar. this project is partially funded by: project pra (2017/18) “palaeoclimatic palaeoenvironmental evolution of the apuan area since the last glacial maximum”. (leader c. baroni), funded by pisa university. references adkins j.f., boyle e.a., curry w.b., lutringer a. (2003) sta ble isotopes in deep-sea corals and a new mechanism for vital effects. geochimica et cosmochimica acta, 67, 1129-1143. aguirre m.l., zanchetta g., fallick a. (2002) stable isotope composition of littoridina australis from the coast of buenos aires province, argentina, during holocene climatic fluctuations. geobios 35, 79-80. aguirre m.l., richiano s., sirch y.n. (2006) palaeoenvironments and palaeoclimates of the quaternary molluscan faunas from the coastal area of bahía vera-camarones (chubut, patagonia). palaeogeography, palaeoclimatology, palaeoecology 229, 251-286. ambrosetti p., arias c., bigazzi g., bonadonna f.p., de giuli c., girotti o., kukla g., iaccarino s., malatesta a., mazzanti r., radicati di brozolo f., trevisan l. (1975) guide book. meeting inqua subcommission on mediteranean and black sea shorelines. pisa-perugia-tarquinia, marzo-aprile 1975, 1-20. pisa. barberi f, buonasorte g, cioni r, fiordelisi a, foresi l, iaccarino s, laurenzi ma, sbrana a, vernia l, villa i.m. (1994) structural and stratigraphic evolution of plio-quaternary volcanism in the tuscany -latium area. memorie descrittive della carta geologica d’italia 49, 77-134. barsotti g., federici p.r., giannelli l., mazzanti r., salvatorini g. (1974) studio del quaternario livornese, con particolare riferimento alla stratigrafia ed alle faune delle formazioni del bacino di carenaggio della torre del fanale. memorie della società geologica italian, 13, 425-475. bedini e., bertolini n., braschi s., cotrozzi s., gani p., niccoli m.a. (1981) dati preliminari sull’età della comparsa di arctica islandica nella zona di collesalvetti (pisa). geografia fisica dinamica quaternaria, 4, 135-137. bellan-santini d., bellan g., bitar g., harmelin j.g., pergent g. (2002) handbook for interpreting types of marine habitat for the selection of sites to be included in the national inventories of natural sites of conservation interest. unep-map rac/ spa, tunis, pp. 217. belluomini g., caldara m., casini c., cerasoli m., manfra l., mastronuzzi g., palmentola g., sanso p., tuccimei p., vesica p.l. (2002) the age of late pleistocene shorelines and tectonic activity of taranto area, southern italy. quaternary science reviews, 21, 525-547. bigazzi g., bonadonna f.p., cioni r., leone g., sbrana a., zanchetta g. (1994) nuovi dati geochimici, petrologici e geocronologici su alcune cineriti pliopleistoceniche del lazio e della toscana. memorie descrittive carta geologica d'italia, xlix, 135-150. bigazzi g., zanchetta g., bonadonna f.p., leone g. (2000) ulteriori dati cronologici sui depositi cineritici del valdarno inferiore (toscana). bollettino società geologica italiana, 119, 121-124. bini m., zanchetta g., ribolini a., salvatore m.c., baroni c., pappalardo m., isola i., isla f.i., fucks e., boretto g., morigi c., ragaini l., marzaioli f., passariello i. (2017) last interglacial sea-level highstand deduced from notches and inner margins of marine terraces at puerto deseado, santa cruz province, argentina. geografia fisica e dinamica quaternaria, 40, 29-39. bini m., isola i., zanchetta g., pappalardo m., ribolini a., ragaini l., baroni c., boretto g., fuck e., morigi c., salvatore m.c., bassi d., marzaioli f., terrasi f. (2018) middle holocene relative sealevel along atlantic patagonia: new data from camarones (chubut, argentina). the holocene, 28, 56-64. bloom a.l., broecker w.s., chappell j.m.a., matthews 82 zanchetta g. et al. 83 r.k. mesolella k.j. (1974) quaternary sea level fluctuations on a tectonic coast: new 230th-234u dates from the huon peninsula, new guinea. quaternary research, 4, 185-205. boretto g., zanchetta g., ciulli l., bini m., fallick a.e., lezzerini m., andre c. colonese a.c., zembo i., trombino l., regattieri e., sarti g. 2017. the loess deposits of buca dei corvi section (central italy): revisited. catena, 151, 225-237. boschian g., bossio a., dall’antonia d., mazzanti r. (2006) il quaternario della toscana costiera. studi costieri 12, 3-207. bossio a., ciampalini a., colonese a.c., da prato s., rafanelli a., zanchetta g. (2008) nuovi dati sulle successioni del sottosuolo di livorno. atti società toscana scienze naturali, memorie, serie a, 113,13-24. bowen d. q. (2010) sea level ~400.000 years ago (mis 11): analogue for present and future sealevel? climate of the past past, 6, 19-29. brand u. (1989) aragonite-calcite transformation based on pennsylvanian molluscs. geological society of america bulletin, 101, 377-390. chefaoui r.m., casado-amezua p., templado j. (2017) environmental drivers of distribution and reef development of the mediterranean coral cladocora caespitosa. coral reefs, 36, 1195-1209. cheng h., lawrence edwards r., shen c.c., polyak v.j., asmerom y., woodhead j.d., hellstrom j., wang y., kong x., spötl c., wang x., calvin alexander e. (2013) improvements in 230th dating, 230th and 234u half-life values, and u-th isotopic measurements by multi-collector inductively coupled plasma mass spectrometry. earth planetary science letters 371-372, 82-91. chutcharavan p.m., dutton a., ellwood m.j. (2018) seawater 234u/238u recorded by modern and fossil corals. geochimica et cosmochimica acta 224, 117. cioni r., sbrana a., bertagnini a., buonasorte g., landi p., rossi u., salvati l., (1987) tephrostratigraphic correlations in the vulsini, vico and sabatini volcanic successions. periodico di mineralogia, 56, 137-155. clark p.u., huybers p. (2009) interglacial and future sea level. nature, 462, 856-857. dall’antonia b., ciampalini a., micheluzzi l., zanchetta g., bossio a., bonadonna f.p. (2004) new insights on the quaternary stratigraphy of the livorno area as deduced by borehole investigations. bollettino della società paleontologica italiana, 43, 141-157. dettman d.l., reische a.k., lohmann k.c. (1999) controls on the stable isotope composition of seasonal growth bands in aragonitic fresh-water bivalves (unionidae). geochimica et cosmochimica acta, 63, 7/8, 1049-1057. drysdale r.n., zanchetta g., hellstrom j.c., fallick a.e., zhao j-x. (2005) stalagmite evidence for the onset of the last interglacial in southern europe at 129±1 ka. geophysical research letters, 32, l24708. dutton a., lambeck k. (2012) ice volume and sea level during the last interglacial. science, 337, 216-219. epstein, s., buchsbaum, r., lowenstam, h. a., & urey, h. c. (1953). revised carbonate-water isotopic temperature scale. geological society of america bulletin, 64, 1315-1326. federici p.r., mazzanti r. (1995) note sulle pianure costiere della toscana. memorie della società geografica italiana, 53, 165-270. felis t., patzold j., loya y., fine m., nawar a.h., wefer g. (2000) a coral oxygen isotope record from the northern red sea documenting nao, enso, and north pacific teleconnection on middle east climate variability since the year 1750. paleoceanography 15, 679-694. ferranti l., antonioli f., mauz b., amorosi a., dai pra g., mastronuzzi g., monaco c., orrù p., pappalardo m., radke u., renda p., romano p., sansò p., verrubbi v. (2006) markers of the last interglacial sea-level high stand along the coast of italy: tectonic implications. quaternary international 145146, 30-54. gazzerro m. (1996) rilevamento e stratigrafia dei depositi plio-pleistocenici dell’area pontederamontopoli/ponsacco-palaia. master thesis, facoltà di scienze matematiche, fisiche e naturali, university of pisa, pp. 183. grossman e.l., ku t.l. (1986) oxygen and carbon isotope fractionation in biogenic aragonite: temperature effects. chemical geology 59, 59-74. hearty p.j., miller g.h., stearns c., szabo b.j. (1986) aminostratigraphy of quaternary shorelines around the mediterranean basin. geological society of america bulletin, 97, 850-858. hearty p.j., hollin j.t., neumann a.c., o’leary m.j., mcculloch m. (2007) global sea-level fluctuations during the last interglaciation (mis 5e). quaternary science reviews, quaternary science reviews, 26, 2090-2112. hoogenboom m., rodolfo-metalpa r., ferrier-pages c. (2010) covariation between autotrophy and heterotrophy in the mediterranean coral cladocora caespitosa. journal experimental biology, 213, 2399-2409. kersting d.k., linares c. (2012) cladocora caespitosa bioconstructions in the columbretes islands marine reserve (spain, nw mediterranean): distribution, size structure and growth. marine ecology, 33, 427-436. kersting d.k., bensoussan n., linares c. (2013) longterm responses of the endemic reef-builder cladocora caespitosa to mediterranean warming. plos one, 8e70820. kim s.t., o’neil j.r. (1997) equilibrium and nonequilibrium oxygen isotope effect in synthetic carbonates. geochimica cosmochimica acta 61, 3461-3475. kousis i., koutsodendris a., peyron o., leicher n., francke a., wagner b., giaccio b., knipping m., pross j. (2018) centennial-scale vegetation dynamics and climate variability in seeurope during stable isotope composition of cladocora caespitosa (l.) from pleistocene raised marine terraces 84 marine isotope stage 11 based on a pollen record fromlake ohrid. quaternary science reviews, 190, 20-38. kruzic p., benkovic l. (2008) bioconstructional features of the coral cladocora caespitosa (anthozoa, scleractinia) in the adriatic sea (croatia). marine ecology, 29,125-139. kružic p., požar-domac a. (2004) banks of the coral cladocora caespitosa (anthozoa, scleractinia) in the adriatic sea. coral reefs, 22, 536. kruzic p., rodic p., popijac a., sertic m. (2016) impacts of temperature anomalies on mortality of benthic organisms in the adriatic sea. marine ecology, 37, 1190-1209. jedoui y., reyss l., kallel n., montacer m., benismayl h., davaud e. (2003) u-series evidence for two high last interglacial sea levels in southeastern tunisia. quaternary science reviews 22, 343351. lazzarotto a., mazzanti r., nencini c. (1990) geologia e morfologia dei comuni di livorno e collesalvetti. quaderni museo storia naturale di livorno, 11, suppl. 2, 1-58. leone g., roselli a. (1989) distribution of oxygen isotopes in molluscan shells from two quaternary shoreline deposits (latium, italy). il quaternario, italian journal of quaternary sciences, 2, 41-47. lohmann k.c. (1988) geochemical patterns of meteoric diagenetic systems and their application to studies of paleokarst. n.p. james and p.w. choquette, capther 2, 58-80. lisiecki l.e., raymo m.e. (2005) a pliocenepleistocene stack of 57 globally distributed benthic δ18o records, paleoceanography. 20, pa1003. doi:10.1029/2004pa001071. lokier s.w., wilson m.e.j., burton l.m. (2009) marine biota response to clastic sediment influx: a quantitative approach. palaeogeography, palaeoclimatology, palaeoecology, 281, 25-42. ludwig k.r., titterington, d.m. (1994) calculation of 230th isochrones, ages, and errors. goechimica et cosmochimica acta, 58, 5031-5042. malatesta a. (1942) le formazioni pleistoceniche del liveronese. atti della società toscana di scienze naturali, memorie, 51, 145-206. marroni m., mazzanti r., nencini c. (1990) l geologia e morfologia delle colline pisane. quaderni del museo scienze naturali livorno, 11, suppl. 1, 159. mauz b. (1999) late pleistocene records of littoral processes at the tyrrhenian coast (central italy): depositional environments and luminiscence chronology. quaternary science reviews, 18, 11731184. marcolini f., bigazzi g., bonadonna f.p., centamore e., cioni r., zanchetta g. (2003) tephrochronology and tephrostratigraphy of two pleistocene continental fossiliferous successions from central italy. journal of quaternary science, 18, 545-556. mcconnaughey t.a. (1989a) δ13c and δ18o isotopic disequilibrium in biological carbonates: i. patterns. geochimica et cosmochimica acta 53, 151-162. mcconnaughey, t.a. (1989b) δ13c and δ18o isotopic disequilibrium in biological carbonates: ii. in vitro simulation of kinetic isotope effects. geochimica et cosmochimica acta 53, 163-171. mcconnaughey t.a., (2003) sub-equilibrium oxygen18 and carbon-13 levels in biological carbonates: carbonate and kinetic models. coral reefs 22, 316 -327. montagna p., mcculloch m., mazzoli c., silenzi s., odorico r. (2007) -the non-tropical coral cladocora caespitosa as the new climate archive for the mediterranean: high-resolution (weekly) trace element systematics. quaternary science reviews 26, 441 -462. nisi m.f., antonioli f., dai pra g., leoni g., silenzi s. (2003) coastal deformation between the versilia and the garigliano plains (italy) since the last interglacial stage. journal of quaternary science, 18, 709-721. olson s.l., hearty p.j. (2009) a sustained þ21 m sealevel highstand during mis 11 (400 ka): direct fossil and sedimentary evidence from bermuda, quaternary science reviews 28, 271-285. patterson w.p., smith g.r., lohmann k.c. (1993) continental paleothermometry and seasonality using the isotopic composition of aragonite otoliths of freshwater fishes. in: swart, p.k., et al., (eds.), climatic change in continental isotopic records, geophysical monograph, 78, 191-202. pedoja k, regard v, husson l., martinod j., guillaume b., fucks e., iglesias m.,weil p. (2011) uplift of quaternary shorelines in eastern patagonia: darwin revisited. geomorphology, 127, 121-142. peirano a., morri c., bianchi c.n. (1999) skeleton growth and density pattern of the temperate, zooxanthellate scleractinian cladocora caespitosa from the ligurian sea (nw mediterranean). marine ecology, progress series 185, 195-201. peirano a., morri c., bianchi c.n., aguirre j., antonioli f., calzetta g., carobene l., mastronuzzi g., orru p. (2004) the mediterranean coral cladocora caespitosa: a proxy for past climate fluctuations? global planetary change, 40, 195-200. peirano a., kružić p., mastronuzzi g. (2009) growth of mediterranean reef of cladocora caespitosa (l.) in the late quaternary and climatic inferences. facies, 55, 325-333. pons-branchu e., douville e., roy-barman m., dumont e., branchu p., thil f., frank n., bordier l., borst w. (2014) a geochemical perspective on parisian urban history based on u-th dating, laminae counting and yttrium and ree concentrations of recent carbonates in underground aqueducts. quaternary geochronology 24, 44-53. railsback l.b., gibbard p.l., head m.j., voarintsoa n.r.g., toucanne s. (2015) an optimized scheme of lettered marine isotope substages for the last 1.0 million years, and the climatostratigraphic nature of isotope stages and substages. quaternary science reviews 111, 94-106. regattieri e., giaccio b., galli p., nomade s., peronace e., messina p., sposato a., boschi c., gemelli m. zanchetta g. et al. 85 (2016) a multi-proxy record of mis 11e12 deglaciation and glacial mis 12 instability from the sulmona basin (central italy). quaternary science reviews, 132, 129-145. regattieri e., zanchetta g., drysdale r.n., isola i., hellstrom j.c., roncioni a. (2014) a continuous stable isotopic record from the penultimate glacial maximum to the last interglacial (160 to 121 ka) from tana che urla cave (apuan alps, central italy). quaternary research, 82, 450-461. rietveld h.m. (1967) line profiles of neutron powderdiffraction peaks for structure refinement. acta crystallographica, 22, 151-152. rimbu n., lohmann g., felis t., pätzold j. (2003) shift in enso teleconnections recorded by a red sea coral. journal of climate 16, 1414-1422. rodolfo-metalpa r., bianchi c.n., peirano a., morri c. (2000) coral mortality in nw mediterranean. coral reefs, 19, 24. rodolfo-metalpa r., bianchi c.n., peirano a., morri c. (2005) tissue necrosis and mortality of the temperate coral cladocora caespitosa. italian journal of zoology, 72, 271-276. royle s.h., andrews j.e., marca-bell a., kružić p., turner j.a. (2015a) seasonality in sea surface temperatures from δ18o in cladocora caespitosa: modern adriatic to late pleistocene, gulf of corinth. journal of quaternary science 30, 298-311. royle s.h., andrews j.e., turner j., kružić p., (2015b) environmental and diagenetic records from trace elements in the mediterranean coral cladocora caespitosa. palaeogeography, palaeoclimatology, palaeoecology 440, 734-749. ruggieri g. (1980) sulla distribuzione stratigrafica di alcuni ostracodi nel pleistocene italiano. bollettino della società paleontologica italiana, 19, 127-135. sarti g., bertoni d., capitani a., ciampalini a., ciulli l., cerrina feroni a., andreucci s., zanchetta g., zembo i. /2017) facies analyses of four superimposed transgressive-regressive sequences formed during the two last interglacial-glacial cycles (central tuscany, italy). atti società toscana di scienze naturali, memorie, serie a, 124, 133150. sarti g., testa g., zanchetta g. (2008) a new stratigraphic insight of the upper pliocene-lower pleistocene succession of lower valdarno (tuscany, italy). geoacta 7, 27-41. shakun j.d., lea d.w., lisiecki l.e., raymo m.e. (2015) an 800-kyr record of global surface ocean δ18o and implications for ice volume-temperature coupling. earth and planetary science letters 426, 58-68. silenzi s., bard e., montagna p., antonioli f. (2005) isotopic and elemental records in a non-tropical coral (cladocora caespitosa): discovery of a new high-resolution climate archive for the mediterranean sea. global and planetary change 49, 94120. stocchi p., vacchi m., lorcheid t., de boer d., simms a.r., van de wal r.s.w., vermeersen b.l.a., pappalardo m., rovere a. (2018) mis 5e relative sea-level changes in the mediterranean sea: contribution of isostatic disequilibrium. quaternary science reviews 185, 122-134. thompson w.g., spiegelmann m.w., goldstein s.l., speed r.c. (2003) an open-system model for useries age determi-nations of fossil corals. earth planetary science letters, 210, 365-381. toucanne s., minto'o c.m.a., fontanier c., bassetti m.a., jorry s.j., jouet g. (2015) tracking rainfall in the northern mediterranean borderlands during sapropel deposition. quaternary science reviews 129, 178-195. tani f. (1996) rilevamento e stratigrafia dei depositi plio-pleistocenici dell’area vicarello-collesalvetti/ ponsacco-capannoli. master thesis, facoltà di scienze matematiche, fisiche e naturali, university of pisa, pp. 199. tzedakis p.c., drysdale r.n., margari v., skinner l.c., menviel l., rhodes r.h., taschetto a.s., hodell d.a., crowhurst s.j., hellstrom j.c., fallick a.e., grimalt j,o., mcmanus j.f., martrat b., mokeddem z., parrenin f., regattieri e., roe k., zanchetta g. (2018) enhanced climate instability in the north atlantic and southern europe during the last interglacial. nature communications, 9, 4235 . doi: 10.1038/s41467-018-06683-3. tudhope a.w., shimmield g.b., chilcott c.p., jebb m., fallick a.e., dalgliesh a.n. (1995) recent changes in climate in the far western equatorial pacific and their relationship to the southern oscillation; oxygen isotope records from massive corals, papua new guinea. earth and planetary science letters 136, 575-590. vertino a., stolarski j., bosellini f.r., taviani m. (2014) mediterranean corals through time: from miocene to present. in: goffredo s, dubinsky z (eds) the mediterranean sea: its history and present challenges. springer, dordrecht, netherlands, 257274. vesica p.l., tuccimei p., turi b., fornós j.j., ginés a., ginés j. (2000) late pleistocene paleoclimates and sea-level change in the mediterranean as inferred from stable isotope and u-series studies of overgrowths on speleothems, mallorca, spain. quaternary science reviews, 2000, 865-879. wefer g., berger w.h. (1991) isotope paleontology: growth and composition of extant calcareous species. marine geology, 100, 207-248. zanchetta g. (1995) nuove osservazioni sui depositi esposti sul fianco sud-orientale delle colline delle cerbaie (valdarno inferiore, toscana). italian journal of quaternary science, 8, 291-304. zanchetta g., mazza p. (1996) anancus arvernensis remains from the basal portion of the arctica islandica-bearing marine deposits of lower valdarno. bollettino società geologica italiana, 115, 105-113. zanchetta g., becattini r., bonadonna f.p., bossio a., ciampalini a., colonese a., dall’antonia b., fallick a.e., leone g., marcolini f., mariotti lippi m., michelucci l. (2006) late middle pleistocene cool stable isotope composition of cladocora caespitosa (l.) from pleistocene raised marine terraces 86 non-marine mollusc and small faunas from livorno (italy). rivista italiana paleontologia stratigrafia, 112, 135-155. zanchetta g., bonadonna f.p., esu d., grassi r., leone g., mazza p. (1998) stratigraphic and paleontologic aspects of middle pleistocene continental deposits from lower valdarno (tuscany). bollettino società geologica italiana 117, 113-132. zanchetta g., bonadonna f.p., marcolini f., ciampalini a., fallick a.e., leone g., michelucci l. (2004) intra-tyrrhenian cooling event deduced by nonmarine mollusc assemblage at villa s. giorgio (livorno, italy). bollettino della società paleontologica italiana, 43, 331-343. zanchetta g., consoloni i., isola i., pappalardo m., ribolini a., aguirre m., fucks e., baneschi i., bini m., ragaini l., terrasi f. (2012) new insights on the holocene marine transgression in the bahía camarones (chubut, argentina). italian journal of geoscience, 131, 19-31. zanchetta g., bini m., isola i., pappalardo m., ribolini a., consoloni i., boretto g., fucks e., ragaini l., terrasi f. (2014) middle-to late-holocene relative sea-level changes at puerto deseado (patagonia, argentina). the holocene, 24, 307-317. zanchetta g. et al. ms. received: june 30, 2019 final text received: september 23, 2019 amq94 d'orefice et al.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 33 (1), 2020, 5-30 latest pleistocene to holocene environmental changes in the northern tyrrhenian area (central mediterranean). a case study from southern elba island. maurizio d’orefice 1, roberto graciotti 1, adele bertini 2, 3, mariaelena fedi 4, luca maria foresi 5, 6, marianna ricci 2, francesco toti 2 1 ispra dipartimento per il servizio geologico d’italia, roma, italy. 2 dipartimento di scienze della terra, università degli studi di firenze, italy. 3 istituto di geoscienze e georisorse, cnr, firenze, italy. 4 istituto nazionale di fisica nucleare, sesto fiorentino, firenze, italy. 5 dipartimento di scienze fisiche, della terra e dell’ambiente, università degli studi di siena, italy. 6 istituto di geoscienze e georisorse, cnr, pisa, italy. corresponding authors: a. bertini <adele.bertini@unifi.it> abstract: geological and geomorphological studies, within the framework of the geomorphological sheet “isola d’elba” (1:50,000, ispra-servizio geologico d’italia) have been implemented by sedimentological, geochronological and biostratigraphical (foraminifers, malacofauna, and palynology) analyses on sedimentary cores retrieved during four continuous mechanical drillings near the marina di campo village. drill cores (s1-s4), up to 23-25 m deep, in sedimentary deposits referable to the last glacio-eustatic cycle allowed the reconstruction of the paleoenvironmental history of the southern sector of the elba island, since the last glacial maximum (lgm). a significant fall in sea level (lowstand systems tract lst) determines the complete emergence and incision of the tuscan continental shelf, including the sector in front of marina di campo, during the lgm. thick fluvial sediments, mainly consisting of gravel, sand and silt alternations filled the river incisions. during the subsequent transgressive phase (transgressive systems tract tst), there was a progressive reduction of fluvial sedimentation and coastline retreat. starting from about 7,000 cal. yr bp a shallow marine environment extended in the eastern sector of the marina di campo plain (s2 at about -10.60 m a.s.l.). meanwhile, in the innermost portion of the plain dark gray organic clays and silts accumulated in brackish lagoons (s3). in both sector, continental deposits that interrupt marine and lagoon sedimentation, attest a brief regressive episode between ~6,600 and 5,800 cal. yr bp. immediately after the regressive episode, the sedimentation of sand, sandy silt and biocalcarenites occurs in a relatively deeper sea (s2, between -8.41 and -3.91 m a.s.l.). in the innermost areas, however, organic clays and silts continue to accumulate in lagoons, whereas in upper areas fluvial sedimentation dominates. with the start of the sea level highstand phase (highstand systems tract hst), around 6,000 cal. yr bp, the ongoing progradation of the barrier-lagoon system determines a regression of the coastline and the eastward extension of brackish lagoons. with the definitive closure of the communication with the open sea, between ca1,500 and 1,300-1,200 cal. yr bp, the marina di campo lagoons were progressively transformed into freshwater coastal ponds. in the areas surrounding the ancient coastal ponds, river sedimentation persisted until today as attested by the current floodplain. keywords: coastal wetlands, geomorphological survey, stratigraphic cores, 14c dating, micropaleontology, palynology, holocene, italy. � 1. introduction coastal plains, especially the mediterranean ones, include a variety of sedimentary archives which allow documenting the main quaternary environmental and climatic changes by the use of several geo-chemical and biotic proxies. many works have been carried out in the coastal plains of corsica (e.g. currás et al., 2017; forzoni et al., 2015), sardinia (e.g. melis et al., 2017, 2018; pascucci et al., 2018) and italian mainland (aguzzi et al., 2005; 2007; amorosi et al., 2008; 2009; 2012; 2013; bini et al., 2010; 2018). these areas have been the field of investigation for geomorphologists, quaternary geologists and archeologists that aimed to reconstruct both fluvial and coastal environments. such multiproxy studies document the prevalent effects of the glacio-eustatic oscillations of the sea level induced by climatic changes, often expressed by an alternation of erosive and depositional phases (e.g. zaitlin et al., 1994; blum & törnqvist, 2000). in this context, systems tracts (lowstand, transgressive and highstand systems tracts) of the high-frequency sequences exhibit a high probability of conservation (posamentier et al., 1988; milli et al., 2016 and reference therein). within the different systems tracts, important changes are frequent in both the channel and stacking patterns of river deposits. in the last millennia, the stratigraphic architecture of the coastal depositional sequences has been greatly https://doi.org/10.26382/amq.2020.01 6 d’orefice m. et al. modified also by anthropic activity (e.g. brückner et al., 2005; bellotti et al., 2016; currás et al., 2017; di rita et al., 2018 and references therein; melis et al., 2018; pascucci et al., 2018; sadori, 2018). the assessment of both the human impact and the possible future effects of the global climate change is indispensable for the preservation of coastal areas and ecosystems, which represent important sites of biodiversity, biological productivity, and ecosystem services (e.g. to remove and manage sediments, nutrients, and contaminants from inflowing rivers). in this context the researches on late quaternary sedimentary successions of the elba island (ei) provide an opportunity to produce new evidence and datasets for a key area of the mediterranean region. ei is situated in the northern tyrrhenian sea between the corsica island to the west and the italian mainland to the east. it is the largest island of the tuscan archipelago (mediterranean sea) and the third largest island of the italian peninsula with a surface area of 224 km2. geological literature on ei principally concerns the well exposed pre-quaternary deposits (principi et al., 2015a, b and references therein). indeed, a few works have focused on the ei late pleistocene to holocene coastal deposits. the more recent field surveys on the main coastal plains of the ei (geomorphological sheet “isola d’elba” at 1:50,000 scale; ispra-servizio geologico d’italia, 2018; d’orefice & graciotti, 2018) provided a unique opportunity to document the late quaternary sedimentary successions by the recovering of several continuous cores in its northern-central and southerncentral sectors (d’orefice et al., 2011) (fig. 1a, b). in our investigation, field data were significantly integrated by sedimentological, geochronological and biostratigraphical (invertebrate microfossils and palynomorphs) studies in order to reconstruct, for the first time, the main late quaternary paleoenvironmental changes, in the elba area, and to correlate them to those acting at regional and global scales. 2. geological and geomorphological setting ei (fig. 1a) represents the westernmost part of the north-apennine orogenic belt. ei formed by a complex stack of tectonic nappes (bortolotti et al., 2015; principi et al., 2015a, b), which sediments refer to paleozoic (variscan orogenesis) to oligocene formations, belonging to both ligurian and tuscan domains (bortolotti et al., 2015; principi et al., 2015a, b). such deposits underwent polyphasic compressive deformations from late cretaceous to middle miocene (bortolotti et al., 2015; principi et al., 2015a, b). the post-orogenic extensive phase characterized by lowand high-angle faults developed during an intense magmatic activity. the latter drove the rise of the monte capanne monzogranitic pluton in the western part of the ei (~6.9 ma; dini et al., 2002), and later the less extensive porto azzurro pluton in the eastern ei (~5.9 ma; saupé et al., 1982; maineri et al., 2003). the location of the intrusive masses promoted the thermo-metamorphism of the enclosing rocks, the topographic uplift of the area and the very last horizontal displacements within the tectonic pile. the predominantly eastward movements caused the anomalous overlap of the previously embricated tectonic units (bortolotti et al., 2015; principi et al., 2015a, b). during the latest miocene early pliocene tectonic events highangle n-s trending normal faults activated especially in the eastern part of the island (bortolotti et al., 2015; principi et al., 2015a, b). the quaternary sedimentary history of ei was strictly controlled by the glacio-eustatic sea level changes, induced by climatic cyclicities, especially during the last glacial-interglacial cycle when a global sea level drop is recorded (e.g. waelbroek et al., 2002; siddal et al., 2003; lambeck et al., 2011). during the last interglacial highstand in correspondence of the marine isotope stage (mis) 5.5 (at ~125 kyr bp) the sea level rises of 7 ±2 m a.s.l., in the italian coast (ferranti et al., 2006, 2010; antonioli et al., 2009a, b). during the last glacial maximum (lgm, upper mis 3 and mis 2), about 30-19 cal. kyr bp (lambeck & purcel, 2004; clark et al. 2009), and in particular at its end, the sea level is about 120–130 m lower than today in the mediterranean sea (fig. 1c). after an initial slow rise (about 5 mm/yr), between 19 and 16 cal. kyr bp, sea level rises rapidly (on average 15 mm/yr) up to about 9 cal. kyr bp (lamberck et al., 2002; 2014), and then progressively decreases as documented in the whole mediterranean area (e.g. boyer et al., 2005; lamberck et al., 2011). from 6 cal. kyr bp the sea level decreases less than 1 mm/yr, approaching a relatively stable position (lamberck et al., 2011; vacchi et al., 2018). from the geomorphological point of view the coastal morphogenetic processes are the most evident ones in the ei; however, due to the frequent high relief, fluvio-denudational and gravitational processes are both well developed. the coastal cliffs, 10 to more than 100 m high, are the most common coastal landforms. they surround most of the island and are subject to continuous retreat due to the wave erosion. sandy and gravelly beaches are rather common and each one can be quite long, such as the magazzini-schiopparello (~2.0 km), marina di campo (~1.5 km), procchio and lacona (~1 km) beaches (fig. 1a, b). in these localities, the backshore commonly hosts holocene foredune systems (d’orefice & graciotti, 2018), fixed in place by vegetation and recently intensely anthropized. at the rear of the dunes system, coastal lagoons were sometimes present in the holocene, with an extension of about 1 km onland (e.g. the tract of mola-capoliveri; fig. 1a) (bortolotti et al., 2015; principi et al., 2015a, b; d’orefice & graciotti, 2018). more ancient systems of coastal dunes (bioclastic quartz-arenites) outcrop in several sites along the coasts of the eastern-central ei (fig. 2a). these deposits formed during lowstand sea level which were related to the cold mis 4 and mis 2 (d’orefice et al., 2007; d’orefice & graciotti, 2008). fluvio-denudational landforms are predominantly erosional, as in the case of valleys, small valleys, gullies, gorges, sheet erosion landforms, ridges and, to a lesser extent constructional landforms which include the gently seawards-dipping alluvial and coastal plains in the eastern-central ei (magazzini, schioparello, san giovanni, fosso della valdana-mola, san martino, lacona, campo nell’elba, 7 latest pleistocene to holocene environmental changes in southern elba island (italy) porto azzurro; fig. 1a). foothill zones, where strips of colluvial deposits put in connection the reliefs with the low lying alluvial plains, are also widespread. landforms due to gravitational processes along slopes are expressed by degradation scarps, rockfalls, rotational landslides and, less frequently, flow landslides. the monte capanne (fig. 1a) slopes are frequently covered by debris deposits (d’orefice & graciotti, 2018). fig. 1 a) geographical location of the elba island and the six boreholes (s1÷s6) drilled by ispra in the frame of the geomorphological sheet “isola d’elba” at 1:50,000 scale (d’orefice & graciotti, 2018; ispra-servizio geologico d’italia, 2018). s1÷s4 boreholes are the object of the present contribution. b) zoom map of the marina di campo area. c) paleogeographic scheme of the northern tyrrhenian area during the lgm. in this period the sea level was lower, compared today, of about 120-130 m and the elba-pianosa ridge was completely emerged and connected to the mainland through a wide corridor. ------------>>>>> fig. 3 simplified geological map of the marina di campo plain, broadly included in the municipal area of campo nell’elba. legend: 1) colluvial deposits (holocene); 2) fluvial deposits (holocene); 3) aeolian deposits (holocene); 4) beach deposits (holocene); 5) lagoon and/ or palustrine deposits (holocene); 6) landslide and slope deposits (upper pleistocene holocene); 7) terraced fluvial deposits (upper pleistocene); 8) porphyry dikes and laccoliths (san martino and orano porphyries upper miocene); 9) monte capanne monzogranite and thermo-metamorphic aureole (upper miocene); 10) calcareous siliciclastic turbiditic sequence (marina di campo formation upper cretaceous); 11) landfill and quarries; 12) debris flow fan; 13) alluvial fan; 14) mechanical continuous-core borehole; 15) hand-auger borehole. (modified from d’orefice & graciotti, 2018). fig. 2 a) aeolian bioclastic quartzarenites outcropping between punta barabarca and stecchi (capoliveri, eastern elba island; fig. 1) at a distance of about 10 m from the present coastline; the two sedimentary bodies are separated by a paleosol (modified from d’orefice & graciotti, 2015). b) debris flow deposit at the foot of the monte capanne western slope (elba island west coast). c) turbidites belonging to the marina di campo formation (upper cretaceous), outcropping along the north-eastern coast of the campo gulf. the bedrock is affected by evident folds. d) upper pleistocene terraced fluvial deposits outcropping in the filetto valley (ne of marina di campo). e) iron slags within holocene fluvial sediments outcropping in the final stretch of the literno valley (northern sector of the marina di campo plain). f) colluvial deposits outcropping near the filetto valley (ne of marina di campo). 8 d’orefice m. et al. 9 latest pleistocene to holocene environmental changes in southern elba island (italy) 2.1. geology and geomorphology of the marina di campo area the marina di campo plain is at the junction between the western and central part of the ei (fig. 1a). the westernmost portion of the ei appears to have a threedimensional hemispheric dome shape, pseudo-circular in plan. such morphology is due to the monte capanne monzogranitic plutonic mass and its thermo-metamorphic aureole. the monte capanne (1,018 m a.s.l.) is characterized by rugged mountain terrain with rocky crests, peaks, steep slopes and deep valley often affected by debris-flow phenomena (fig. 2b). instead, the central sector of ei is characterized by modest elevation reliefs (<400 m), internally separated by flared and shallow valleys drained by short brooks. the hill-like reliefs in the westernmost part of this sector are formed by marina di campo formation (fig. 2c) which consists of upper cretaceous arenaceous-conglomeratic and calcareousmarly-arenaceous turbidites belonging to the ripanera tectonic unit (bortolotti et al., 2015; principi et al., 2015a, b). the marina di campo formation is intruded by dykes and laccoliths, frequently with porphyric texture, and acid in composition, emplaced in different time, ranging from 8 ma (san martino porphyry) to ca. 6.8 ma (orano porphyry) (fig. 3). the ripanera tectonic unit is separated by the monte capanne thermo-metamorphic aureole by means of a high-angle, east-dipping normal fault, named after the localities of colle di palombaia-procchio (bortolotti et al., 2015; principi et al., 2015a, b). since this structure downthrows, towards the east, the ripanera unit with respect to the monte capanne thermo-metamorphic district, it is probably responsible for the formation of the marina di campo alluvial plain. the marina di campo plain is interrupted by two rock spurs (serra di mamiliano and la serra), which are isolated outcrops of the marina di campo formation. these spurs divide the plain into three wide valleys (widths between 500 and 700 meters), gently dipping towards the campo gulf, where the alzi, bovalico and pila-galeo streams debouch (fig. 3). late quaternary continental deposits outcrop in the valley floors and in the foothills of the surrounding reliefs, and they gradually pass seawards to coastalmarine sediments. the continental deposits are essentially represented by upper pleistocene and holocene alluvial sediments. the most ancient alluvial deposits are incised and terraced by the holocene drainage network and, accordingly, no longer affected by the current fluvial dynamics. they are basically relict fluvial plains whose uppermost depositional surfaces are at 10-15 m above the present sea level (d’orefice & graciotti, 2018). such surfaces are the top of sedimentary bodies, sometimes more than 10 m-thick, constituted by heterometric, poorly rounded pebbles, heterogeneous in composition and largely immersed in a brown-reddish sandy to silty matrix (fig. 2d). conversely, the most recent fluvial deposits are composed of finer granulometries, such as silts, sands and fine-grained, poorly sorted and subangular gravels. embedded in such deposits, angular metal clasts (slags), pluri-centimetric in size, can be found, probably reflecting the remains of the metallurgic fusion of the iron minerals during the etruscan, roman and medieval times (fig. 2e). the thickness of these deposits is variable and can locally exceed some meters (d’orefice & graciotti, 2018). the fluvial deposits laterally pass into extensive and thick colluvial sediments (fig. 2f) or small alluvial fans, as well as debris flow deposits. in the littoral zone, lagoon and marshy deposits consisting of ultra-dark organic silty clays outcrop at shallow depth. these deposits suggest the presence of past coastal lagoons, developing behind the holocene fig. 4 frame n. 4105 of the "raf fund" kept at the iccd-aerofototeca nazionale. the photo, south oriented, was taken on january 2, 1944 on the campo gulf. it shows the holocene dune system parallel to the coastline and the coastal plain behind, once occupied by ancient lagoons (a: albarelli; b: stagno; c: la serra). these lagoons, partly included in the photo, are highlighted with oblique red striped (authorization to use for editorial purposes on the part of iccd mibact and the british school at rome further reproduction and/or duplication by any means is prohibited). 10 d’orefice m. et al. etry technique. the samples were classified according to the criteria of the italian geotechnical association (agi, 1977). 3.3. micropaleontological assemblages 96 samples (46 from s2 core and 52 from s3 core) were analysed at the micropaleontological laboratory of the university of siena for macroand micropaleontological contents, paying particular attention to the foraminiferal assemblages. samples were prepared with classic washing technique (green, 2001 and reference therein): sediment samples were dried and weighed (weighs vary from a minimum of ~100 g to a maximum of ~400 g), sieved in water over a 63 �m sieve, then dried in oven. to facilitate the analyses, the fraction >2 mm was observed separately. both preparation and sample analyses were performed from the stratigraphic top to bottom. 3.4. palynology palynological analysis was carried out on 28 samples from the two cores having more favorable lithologies (i.e. clay, rich-organic clay, silt) and a good chronological frame i.e. s2 and s3. the samples (14 from s2 and 14 from s3 cores) were processed at the palynological laboratory of the university of florence, according to standard chemical-physical procedures which main steps are below specified. following the addition of one lycopodium tablet to determine palynomorph concentrations, samples, each weighing 10 g, were treated with hf, hcl, sodium hexametaphosphate, koh, zinc chloride separation (density solution at 2.0). residues were then sieved in an ultrasonic bath using a 10 mm polymer mesh. mobile slides were mounted using glycerol and analysed using optical microscopes. 3.5. radiocarbon dating. 29 samples from s1, s2, s3 and sm4 cores were dated by accelerator mass spectrometry (ams) in both the laboratories at cedad (salento university) and at infn-labec (florence; fedi et al., 2007). datings were carried out on samples including microfossil shells, charcoals and other vegetal remains. before any chemical treatment, the collected samples were observed under the optical microscope to identify possible macroscopic contaminants. charcoals and vegetal remains were treated according to the so-called acid-base-acid (aba) procedure, in order to remove possible contaminations by carbonates and humic substances. carbon was then extracted from the cleaned samples as co2 by acidification, in the case of shells, or by combustion, in the case of charcoals and other organic materials. in both laboratories, graphite pellets for the ams measurement were obtained by reaction of co2 with h2, in the presence of iron as catalyst. 14c/12c isotopic ratios measured in the unknown samples were corrected for background counts and for isotopic fractionation, by measuring the 13c/12c isotopic ratios in the accelerator beam line too. iaea-c6 sucrose and nist oxalic acid ii were used as primary standards for normalization purposes in case of samples measure at cedad and at infn-labec, respectively. according to the international agreement, the measured conventional radiocarbon ages are shown as dune systems of marina di campo, parallel to sandy beach ridge and bow-like shaped. more in detail, three separated fossil lagoons have been distinguished: the first one is between the camping area and the la serra locality (northern sector of the plain), the other two are closely behind the inhabited area (albarelli and stagno localities) (figs. 3 and 4). the real limit of the lagoon areas does not actually coincide with the one shown in fig. 3, as it is downsized by the current river sedimentation. the marine sector, included in the gulf of campo, can be considered the underwater continuation of a pocket-beach, whose morphology closely follows the trend of the coast up to the isobath -50. here the sea bottom, slightly sloping towards se, is characterized, up to about 40 m below sea level, by sandy and gravelly holocene deposits of hst, with a thickness between about 2 and 6 m (principi et al., 2015b). these deposits pass to sandy pelites between -40 and -60 m. below the isobath -60, under a limited quaternary cover, a continental abrasion shelf modeled on ancient sediments develops (principi et al., 2015b). this platform extends southward for about twenty kilometers. 3. materials and methods the geological and geomorphological mapping (1:10,000 scale) was supported by historical to recent bibliographic-cartographic literature, as well as by published scientific data, technical geological reports, geognostic investigations, multiscalar and multitemporal photo-interpretation. the photo-interpretation was based on the flights: 1944-45 raf (britain royal air forces), 1954-55 gai (italian air group), 1975, 1995, 1996, 1997, 1998 (tuscany region) and 1988-1989 (italian photo aerial archives). 3.1. drillings late quaternary stratigraphy of marina di campo coastal plain was reconstructed by means of four continuous mechanical coring performed by crawler drill rig of general trivel company (boreholes s1-s4; � 101 mm), down to 23-25 m below the ground surface (bgs). four additional surface boreholes (sm2, sm3, sm4 and sm7), 3.20 to 4.10 m bgs, were also performed with a manual auger. the recovered sedimentary successions were submitted to sedimentological, biostratigraphical (foraminifers, malacofauna and palynology) analyses, as well as ams dating. analyses have been carried out mainly on the s1 and s2 cores because of their appreciable lithological variability and the relatively higher micro-macrofaunistic and pollen content. such features assure on the possibility to reconstruct the various sedimentary paleoenvironments in the study area. 3.2. grain size analysis quantitative and qualitative granulometric analyses were processed. the quantitative analysis (35 samples: 14 from the s2 core and 21 from s3 core) of the coarser fraction (>0.074 mm) was determined by wet sieve technique, while the finest one was determined by densitom 11 latest pleistocene to holocene environmental changes in southern elba island (italy) years before present (bp). calibration has been performed following the intcal13 and marine13 calibration curves (reimer et al., 2013) and using oxcal software, v.4.3 (bronk ramsey, 2009). in the case of samples collected from s2 and s3 cores, calibration was performed using a bayesian approach, i.e. considering what we a priori knew about the samples relative chronology as inferred from the stratigraphy (bronk ramsey, 2008; bronk ramsey & lee, 2013). the p_sequence algorithm was applied for the calibration to consider also the possible variability in sedimentation rate. 4. results 4.1. borehole lithostratigraphy s1 borehole it covers 23 m bgs (between 4.00 and -19.00 m a.s.l.) (fig. 5). the 23.00 to 10.40 m bgs interval includes a well stratified alternation of gravel and silty sand (sometime weakly gravelly). the generally heterofig. 5 stratigraphic logs of the cores recovered in the marina di campo coastal plains (campo nell’elba municipality) according to a swne transect. for the description of the sedimentary units and subunits see the text at 4.1. s1: n42°45.420' e10°14.414’ (la pila); s2: n42°44.735’ e10°13.821’ (near the school of marina di campo); s3: n42°45.235' e10° 14.374’ (la serra); s4: n42°44' 27.03'' e10°13' 35.68” (albarelli). 12 d’orefice m. et al. metric, heterogeneous, subangular and often reversely graded gravels have an open-work texture in the basal 1.60 m (between 23.00 and 21.40 m bgs). the interval between 10.40 and 7.00 m bgs is mainly formed by greyish silty clay weakly sandy, with ocher colour streaks and thin intercalation of fine-grained gravel. two coarser-grained beds intercalate in the silty clay: the first one (between 10.00 and 9.40 m bgs) is composed of silty-clayey sand with ocher colour streaks; the second one (7.60÷7.55 m bgs) is composed of fine-grained gravels. the succession, predominantly formed by gravels between 7.00 and 1.60 m bgs, is interrupted by a dark silty clay stratum containing vegetal remains, between 5.00 and 4.50 m bgs. gravels are generally finegrained, heterogeneous and supported by a silty-sandy matrix. the gravels pass, between 1.60 and 1.00 m bgs, to a silty clay weakly gravelly. the core ends at the top with one meter of brown silty sand weakly gravelly. s2 borehole s2, from 1.29 m a.s.l., reached the maximum depth of 25.00 m bgs (-23.71 m a.s.l.) (fig. 5). the interval from 25.00 to 11.90 m is characterized by gravel beds alternating with prevalently silty clayey sand beds. gravels, supported by a sandy-silty matrix, are heterometric (from few mm up to 8 cm in diameter), heterogeneous (clasts from monzogranitic, porphyritic and arenaceous lithotypes) and subangular. the gravelly strata may exhibit a reverse grading, while the finer beds are sometimes characterized by oxidized sandy laminae. the gravelly strata reach a thickness of 150 cm on average, while those consisting of silty clayey sand have thicknesses between 20 cm and 230 cm. a sharp erosive contact separates this interval from the overlying one. the interval between 11.90 and 11.10 m bgs is formed by fine sand weakly silty and clayey with tiny fragments of marine shells. the interval between 11.10 and 9.70 m bgs includes, at the base, a 20-cm thick gravel level rich in siliceous and poorly elaborate centimetric clasts in fine matrix. the gravels are in their turn overlain by a laminated silty clayey sand with ocher speckles, passing upwards to fine sand with clayey silt having a total thickness of 120 cm. between 9.70 and 5.20 m bgs fossil-rich strata are present. they consist of sand, silty clayey sand and sand with clayey silt, alternating with three biocalcarenites strata: the first one between 9.70 and 9.40 m, the second one between 8.50 and 8.40 m and the third one between 7.50 and 6.30 m. between 5.20 and 1.10 m bgs, plastic organic clay with sandy silt, dark gray in color, predominate. the contact with the underlying deposits is sharp. the continuity of this clayey interval is interrupted, in its lower portion (between 4.35 and 4.65 m bgs), by sand (mainly of carbonate composition and whitish color from 4.65 to 4.60 m bgs) with clayey silts and, in the central portion (from about 3.30 to 3.45 m bgs), by sand with clayey silt weakly gravelly. in the organic clays are present up to about 1.60 m bgs, mollusks (unbroken or in fragments), and ostracods, while the remaining portion (between 1.60 and 1.10 m bgs) contains only vegetal remains. the sandy-clayey silt top interval (between 1.10 and 0.50 m bgs), is barren in mollusks and covered by 50 cm of landfill containing anthropogenic remains. s3 borehole s3, from 1.33 m a.s.l., reaches a maximum depth of 24.00 m bgs (-22.67 m a.s.l.) (fig. 5). the lower part, from 24.00 to 13.50 m bgs includes from the bottom: open-work and normally graded loose coarse gravels; silty gravelly sands weakly clayey; sands with clayey silts; sandy matrix-supported and normally-graded coarse and fine gravels; sands with weakly clayey silty gravels. this interval does not contain marine macro-fossil remains and presents many similarities with the basal part of s2 from the lithological, granulometric and textural point of view. the 13.50÷12.15 m bgs interval consists, for the first 30 cm, of silt with sandy clay, overlain by 105 cm of very dark clay with sandy silt progressively richest in fossils upwards. the 12.15÷8.30 m bgs interval mainly includes silty clayey sands, silts with sandy clays, clayey silty sands and clayey gravelly silts. the interval 8.30÷4.00 m bgs is characterized by plastic organic clays (dark clays with sandy silts), passing upwards (from 4.00 to 1.80 m bgs) to a silt with clay weakly sandy. the upper part, from 1.80 to 0.87 m bgs, consists of silts with clay weakly sandy, with abundant mollusks (up to 1.65 m bgs) and vegetal remains. the last 0.87 m are characterized by the presence of sandy clayey silt weakly gravelly, affected by pedogenic and anthropogenic reworking processes. s4 borehole s4, from 7.00 m a.s.l., reaches a maximum depth of 23.50 m bgs (-16.50 m a.s.l.) (fig. 5). it is a quite uniform succession, largely characterized by clayey sandy silts, frequently weakly gravelly, with intercalated silty clayey or sandy silty gravel beds (at 16.90÷16.50, 15.60÷14.80, 12.10÷11.90, 6.00÷5.00 m bgs intervals). a silty clay stratum with ocher speckles is present in the upper part, between 2.60 and 1.70 m from bgs. hand auger drillings the manual drillings sm2 (max depth 3.20 m bgs) and sm4 (max depth 4.10 m bgs), include respectively from the bottom, about 0.20 m and 1.10 m of silt with clay weakly sandy, passing upwards to an alternation of silty clay and sand, at places coarse, which are 2 m (sm2) and 2.50 m (sm4) thick. at the top of both drillings is present a dark organic clay with silts, of variable thickness between 0.50 (sm4) and 1.00 m (sm2). the manual drilling sm3 (max depth 3.50 m bgs) includes from the bottom: 0.20 m of blue-gray clays; 1.70 m of clayey silts alternate to coarse sands; 0.40 m of gray clay; 0.80 m of clayey silt with sand; 0.40 m of topsoil. the manual drilling sm7 includes only 0.5 m characterized by the large occurrence of coarse anthropogenic remains. the overall granulometric, textural and sedimento 13 latest pleistocene to holocene environmental changes in southern elba island (italy) logical characteristics and subordinately the macrofossiliferous content (mollusk shells, vegetal remains, etc.) of s1-s4 and sm2-4-7 cores permitted to describe 3 main sedimentary units (units 1 ÷3) organized in 6 subunits (1a, b, c, d, 2a and 2b). the main features of these sedimentary units (su) are shortly described as follows and shown in figure 5: su 1a consists of an alternation of heterometric, heterogeneous, subangular gravel beds with prevalently silty clayey sand beds, sometimes characterized by oxidized sandy laminae. su 1b is composed of greyish silty clay weakly sandy, with ocher colour streaks and thin intercalation of finegrained gravel. su 1c consists of an alternation of silty clayey sands, silts with sandy clays, clayey silty sands and clayey gravelly silts su 1d is composed of clayey sandy silts, frequently weakly gravelly, with intercalated silty clayey or sandy silty gravel beds. su 2a consists of fine sand weakly silty and clayey with tiny fragments of marine shells. su 2b consists of fossil-rich sand, silty clayey sand and sand with clayey silt, alternating with biocalcarenites strata. su 3 is mainly characterized by dark plastic organic clay with sandy silt, passing upwards to a silt with clay weakly sandy; mollusks, ostracods and vegetal remains are abundant. 4.2. geochronology the results of radiocarbon (14c) measurements are summarized in table 1. in s2, datings of ltl4914a (6.50 m bgs; 35,240 ±400 yr bp) and ltl4783a (4.95 m bgs; 4,090 ±45 yr bp) samples suggest an interval of ca. 30 kyr in solely 1.5 m of sediments. this evidence could be interpreted either as due to the occurrence of a hiatus or the intervention of environmental factors causing non-accurate radiocarbon dates for shells (e.g. tab. 1 results of radiocarbon (14c) dating. c = sample of continental environment; w = sample of freshwater wetland environment; l = sample of brackish lagoon environment; m = sample of marine environment. 14 d’orefice m. et al. gischler et al., 2008; douka et al., 2010). the first hypothesis (i.e. a hiatus) was discarded, because the occurrence in the s2 strata of some specimens of the pink morphotype of globigerinoides ruber (g. ruber rosea, see section 4.3). this taxon, recorded from the upper pleistocene, shows significant percentages only during interglacial phases (during mis 5 and mis 1). lagoon sediments in s2 were deposited in continuity of sedimentation over the marine deposits of the submerged beach (from which come the specimens of g. ruber rosea) stratigraphically referable to the mis 1 interval. such stratigraphical attribution is in apparent contrast to the datings ranging between about 39 and 22 kyr (tab. 1). the second hypothesis seems more likely. indeed, the continental waters (river input), enriched with inorganic carbon coming from the limestones of the marina of campo formation, could have mixed with the marinecoastal ones (i.e. lagoons). recrystallization of carbonates, i.e. the incorporation of secondary caco3 from the external environment needs also to be considered. the measured ages of the older shell samples do not fit with the relative chronology inferred from the stratigraphy: this can be interpreted as a further suggestion of problematic radiocarbon dating. in the upper part of s2, both marine and terrestrial samples can be organized in a coherent stratigraphical succession, with the exception of samples ltl15770a (2.25 m bgs; 923 ±45 yr bp) and fi3235/37 (2.54 m bgs; 205 ±30 yr bp) (fig. 6). in particular, the very young age of the charcoal sample ltl15770a and in particular of the wooden sample fi3235/37 can be due to an infiltration phenomenon by modern material, probably roots. in s3 three samples, ltl16444a (2.57 m bgs; 4,534 ±40 yr bp), ltl5752a (3.90 m bgs; 5,830 ±40 yr bp) and ltl5754a (5.75 m bgs; 4,290 ±45 yr bp), appear as outliers. figure 7 shows the probability density functions of calibrated ages as calculated after excluding these samples: the sequence spans several fig. 7 age-depth profile of core s3, as obtained after running the p_sequence model in oxcal. a posteriori distributions of probability for calibrated ages are reported using different colours according to samples origin, either marine or terrestrial. different colours are also used to highlight the different average sedimentation rates along the whole core. fig. 6 age-depth profile of core s2, as obtained after running the p_sequence model in oxcal. a posteriori distributions of probability for calibrated ages are reported using different colours according to samples origin, either marine or terrestrial. 15 latest pleistocene to holocene environmental changes in southern elba island (italy) tab. 2 results of the macroand micro-paleontological analyses from the s2 borehole. legend: a = abundant; c = common; r = rare; x = not estimated abundance; r? = not in place. millennia, since the fifth millennium bc to the early middle ages. abrupt changes in the sedimentation rates (at least three) should be considered to obtain a satisfying agreement with the previous information. 4.3. bioindicators 4.3.1. observation from >63 �m washed residues s2 borehole microfossils remains were first recovered from the interval between s2 11.83-11.90 and s2 11.18-11.26 (interval s2-b in tab. 2); they include mollusks, ostracods, bryozoans, serpulids, echinoids, sponge spicules, planktonic and benthonic foraminifers with common ammonia beccarii, asterigerinata mamilla, elphidium spp. and quinqueloculina spp. microfossils are absent from the base of s2 core and in interval s2-c (tab. 2) from sample s210.90-11.00 and s2 9.80-9.90. an abundant and well-diversified fossiliferous fraction (mollusks, ostracods, serpulids, bryozoans, calcareous algae, echinoids, sponge spicules and benthic and planktonic foraminifers) is present in the sediments between sample s2 9.55-9.60 and sample s2 4.60-4.66 (interval s2-d in tab. 2). among benthic foraminifers, the most common taxa are ammonia beccarii, asterigerinata mamilla, elphidium spp., lobatula lobatula, nubecularia lucifuga, rosalina spp., as well as several miliolid specimens of triloculina and quinqueloculina genera. planktonic foraminifera, though rare, are represented by the species globigerina bulloides, globigerinoides ruber, g. elongatus, g. trilobus and orbulina universa. concerning the globigerinoides ruber, it should be noted that the sample s2 7.20-7.25 from interval s2-d contains some specimens of the pink morphotype (g. ruber rosea). from s2 5.30-5.40 m (upper part of interval s2-d), significant changes in the assemblages are marked by the appearance of the genera cerastoderma glaucum, abra ovata and hydrobia sp. among mollusks and by ostracods with a large number of non-ornamented speci 16 d’orefice m. et al. mens. moreover, vegetal remains are abundant, including fruits of ruppia (martinetto, personal communication). the upper part of the borehole, between s2 4.51-4.58 and s2 1.80-1.88 (interval s2-e in tab. 2) is characterized by oligotypic assemblages composed of mollusks (only cerastoderma glaucum, abra ovata and hydrobia sp.), ostracods (only non-ornamented taxa) and foraminifers, with rare specimens of ammonia tepida and nonion depressulum. here abundant vegetal remains (including ruppia fruits and characeae oogons only the internal organic lining) are also present. the uppertab. 3 results of the macroand micropaleontological analyses from the s3 borehole. legend: a = abundant; c = common; r = rare; r? = not in place. 17 latest pleistocene to holocene environmental changes in southern elba island (italy) 18 d’orefice m. et al. <<<<<- ---------- fig. 8 selected pollen grains from s2 and s3 boreholes. 1 = pistacia; 2 = cannabaceae; 3 = vitis; 4 = ephedra distachya type; 5 = quercus suber t.; 6 = betula; 7 = artemisia; 8 = celtis; 9 = ulmus; 10 = poaceae; 11 = hedera; 12 = fagus; 13 = abies; 14 = tilia; 15 = cistus; 16 = quercus ilex t. ------------>>>>> fig. 9 detailed palynological diagram of s2. on the left the samples and the sum of arboreal and non-arboreal pollen (ap, nap). *: peak of pseudoschizaea. most part of the succession, from sample s2 1.48-1.58 to sample s2 1.18-1.28 (interval s2-f in tab. 2), contains only vegetal remains. s3 borehole fossil remains first occur in sample s3 13.3013.35 (base of interval s3-b in tab. 3) and they are represented by rare vegetal remains and very rare mollusks fragments of cerastoderma glaucum and abra ovata (tab. 3). from this level up to s3 12.20-12.25 (top of interval s3-b in tab. 3), the assemblages are richer, but not diversified. in fact, among the mollusks, only hydrobia genus is added to the species mentioned above. in interval s3-b, ostracods (with nonornamented valves) and benthic foraminifers (with rare ammonia tepida and nonion depressulum) first occur; the remains of plants are abundant, and among them ruppia fruits are present. from sample s3 11.75-11.78 to sample s3 8.658.70 (interval s3-c in tab. 3), the fossils are rare and represented by vegetal remains found in two levels only. from sample s3 8.40-8.46 to sample s3 1.80-1.85 (interval s3-d in tab. 3), the assemblages resemble those of interval s3-b (tab. 3), with abundant plant remains (including ruppia fruits), mollusks (cerastoderma glaucum, abra ovata and hydrobia sp.), ostracods (with non-ornamented valves), scarce remains of fishes and insects and also benthic foraminifers, with ammonia tepida and nonion depressulum. the top of the borehole, from s3 1.50-1.55 to s3 0.93-1.00 (interval s3-e in tab. 3), contain very abundant vegetal remains only. 4.3.2. palynology palynological samples provided rich palynomorph assemblages solely for the upper portions of s2 and s3 cores; selected photos of palynomorphs from s2 and s3, at light microscopy, are shown in figure 8. s2 borehole fourteen samples from s2 were submitted to palynological analyses. the lowest four samples, located between -23.45 and -6.15 m, are barren in palynomorphs. the ten fertile samples, between -5.10 and 1.18 m, consist of sand with clayey silt and dark clay with sandy silt deposits. their pollen concentration ranges from 681 grains/g (s2 3.33-3.43) to 32,897 grains/g (s2 4.00-4.10). all detected pollen taxa (69) are listed, with the respective percentages for each sample, in the palynological diagram of figure 9. among the arboreal plants (ap, 21 taxa) both de 19 latest pleistocene to holocene environmental changes in southern elba island (italy) ciduous and evergreen oaks (quercus pubescens type, q. suber type and q. ilex type) reach quite high proportions up to 40%. pinus is continuously present though in low values generally between 1 and 3%. alnus (1.0 to 4.7%) is followed on lower values, by many other arboreal taxa such as carpinus (c. orientalis and c. betulus), fagus, olea, betula, ulmus, corylus, picea, abies, acer, celtis, juglans and cupressaceae. 48 nonarboreal plants (npa) taxa were detected. pistacia reaches good percentage (0.2 to 3.6%). rare: hedera, vitis, rhus, buxus, euphorbia, mercurialis. ericacee, often dominant (15 to 37%), are followed by amaranthaceae (1.5 to 23.8%) and asteraceae (cichorioideae and asteroideae, from 1.0 to 17%). samples at the core top (from the sample s2 3.00-3.10 to the sample s2 1.18-1.28) showed a good occurrence of cyperaceae too (up to 30%). present in good quantity poaceae (1.6 to 5.7%) and cistus (0.2 to 4.7%). more discontinuous: apiaceae, artemisia, plantago, brassicaceae, cannabaceae, caryophyllaceae, cistaceae, helianthemum, convolvulaceae, convolvulus, fabaceae, gentianaceae, geraniaceae, erodium, geranium, hypericum, lamiaceae, malvaceae, cereals, polygonum, rumex, ranunculaceae, rosaceae, galium, scrofulariaceae, urticaceae and sparganium. spores of pteridophyta (trilete and monolete) are also present. dinocysts and other algae are present albeit sporadically. dinocysts were observed in s2 6.15-6.23 (polysphaeridium zoharyi) and s2 4.30-4.40. a peak of pseudoschizaea is recorded in s2 3.33-3.43 sample. as a summary, with the exception of the three deepest samples, between -5.10 and -4.30 m, for which the arboreal plants percentage is slightly greater than that of herbaceous plants and shrubs, in the above samples is observed a dominance of non-woody plants (up to 80%) which is especially significant for samples s2, 3.33-3.43, 2.00-2.10 and 1.18-1.28. altitudinal arboreal taxa such as abies, betula and fagus (one pollen grain of picea in s2 1.18-1.28 sample), though always with a few grains, are a constant presence throughout the diagram. even pinus, always below 3%, does not show significant variations even in correspondence of the major changes in the depositional environment. starting from 5 m bgs, the palynological record shows a good occurrence of tree taxa largely represented by deciduous and evergreen oaks with values up to about 40%. the amaranthaceae expansion highlights the establishment of a salt marsh at -4.00, -4.30 m (over 20% in s2 4.00-4.10). this is followed at -3.33 to -3.43 m by a phase characterized by a good presence of nap both herbaceous (asteraceae, cistus, poaceae) and shrubs (ericaceae, pistacia), as well as from a minimum in the pollen concentration values and a spike in pseudoschizaea. upwards increasing nap is mainly linked to the expansion of ericaceae, which is sometimes in parallel to that of cyperaceae (s2: 2.00-2.10 and 1.181.28) which marks the establishment of a freshwater environment. to underline two minima in the percent ------------>>>>> fig. 10 detailed palynological diagram of s3. on the left the samples and the sum of arboreal and non-arboreal pollen (ap, nap). *: peak of pseudoschizaea. 20 d’orefice m. et al. ages of both deciduous and evergreen oaks in correspondence of the two phases of expansion of cyperaceae and ericaceae, in s2 2.00-2.10 and s2 1.18-1.28 samples. s3 borehole fourteen samples from s3 were taken for palynological analyses (fig. 10), three of them were barren in palynomorphs. all rich palynomorphs samples come from deposits, mainly consisting of clayey silt and dark clays with sandy silt. the eleven fertile pollen samples exhibit high concentration values, ranging 743 grains/g (s3 7.35-7.40) to 76,684 grains/g (s3 1.80-1.85) (fig. 10). 62 pollen taxa have been detected. the arboreal plants (ap, 20 taxa) mainly consist of deciduous and evergreen oaks (up to about 40%) and alnus (2.75 to 25.9%). pinus ranges between 1.1 and 3.7%. corylus (up 2.8%), olea (up 2.3%) and fagus (up 1.3%) are present, sometimes in good quantities. follow carpinus (c. orientalis and c. betulus), cupressaceae, abies, picea, acer, betula, fraxinus, tilia and ulmus. non-arboreal plants (nap, 42 taxa) are represented by shrubs like pistacia (up 1.5%), hedera, buxus, viburnum e vitis. ericacee range between 9.5 and 42%. among the herbaceous taxa are present asteraceae cichorioideae (1.5 to 37.3%), cyperaceae (2.3 to 25.7%), poaceae (2.8÷7.5%) and amaranthaceae (0.6÷7.6%) followed by asteraceae asteroideae (0.8÷7.3%) and cistus (0.2 to 2.7%). more sporadic: apiaceae, artemisia, centaurea, borraginaceae, campanulaceae, cannabaceae, caryophyllaceae, helianthemum, cuscuta, cf. arbutus, fabaceae, erodium, hypericum, lamiaceae, plantago (p. mayor t. and p. lanceolata t.), cereals, polygonum, rumex, ranunculaceae, scrofulariaceae, rosaceae, galium, alismataceae, liliaceae and sparganium. spores of pteridophyta (trilete and monolete) and algae are also present. dinocysts occur in all samples excepted in s3 5.05 -5.12; pseudoschizaea, never absent, shows a main peak at s3 7.35-7.40 and a secondary one at s3 13.1013.15. the palynological record begins at -13.10 m with a phase dominated by the non-arboreal plants in coincidence with a minimum in the concentration values and a good occurrence of pseudoschizaea. among the nap prevail asteraceae cichorioideae followed by cyperaceae, ericaceae, a. asteroideae and poaceae. cyperacee, in particular, recorded here their main peak of abundance, reaching 26%. trees showed a subsequent increase at 12.20-12.25 m, attested by the presence of several species of quercus and alnus, which are followed by pinus and olea. carpinus (c. betulus and c. orientalis), corylus, acer, tilia and ulmus are also present. among the altitudinal arboreal taxa, although always low, there are abies, fagus and betula. among the nap to remark the abrupt fall of a. cichorioideae (from 37.3% to 4.6%) and the sharp increase of ericaceae from 9.5% to 24.5%. the palynological record, after the barren interval linked to the occurrence of unfavorable sediments for pollen preservation, starts again from -8.10 m. from here up to -1.80 m is observed a dominance, albeit marked by successive fluctuations between arboreal (oaks with peaks in s3: 8.108.18; 5.60-5.70; 5.05-5.12; 4.00-4.08; 2.35-2.40) and non-arboreal plants (ericaceae). ericaceae record a maximum (42%) in 2.95 -3.00 m in correspondence to a phase of decline of the oaks: q. ilex in particular presents here its second minimum value (3.35%), after that characterizing the base of the succession (0.61%). the cyperacee, though still present, are reduced to values ranging between 2.3% and 7%. at -7.30 m a minimum in the pollen concentration values falls in coincidence, again, with a main peak of pseudoschizaea. moreover this level is characterized by a sharp increase in asteraceae, especially cichorioideae, reaching 34% and by a phase of temporary reduction of alnus, oaks and ericaceae. in all s3 samples, pinus and olea, although always present, are never abundant. the same pattern was also observed in s2. 5. discussion 5.1. sedimentary architecture and depositional settings the collected data permitted to detect four main depositional environments and associated facies (figs. 5, 11, 12). 1) fluvial (f) it has been observed throughout s1 and s4, in the lower half of s2, and in the lower and middle portion of s3. it is mainly expressed by an alternation of gravels and sands/silts weakly clayey (su 1a and su 1b in s1, s2, s3); an alternation of silty clayey sands and silts with sandy clay (su 1c in s3); a succession largely consisting of clayey sandy silts, with intercalated, siltyclayey or sandy-silty gravels beds (su 1d in s4). gravels, from matrix support to open work texture, are heterometric, heterogeneous and subangular. gravels sometimes show an inverse gradation; the finer ones are sometimes characterized by yellow-brown mottles and thin sandy plane-parallel laminae with oxidation from ocher to reddish color. alluvial plain deposits depict the occurrence of channel and floodplain facies, with intercalated debris flows. samples are generally barren in both palynomorphs and marine/brackish fossils (interval s2-a, s2-c, s3-a, s3-c). 2) marine (m) a marine depositional environment is only detected in the medium-upper portion of s2 where it rests on fluvial deposits by a sharp and erosive contact. it includes two main facies (m1 and m2). m1-shallow marine. the facies, about up to 80 cm thick (from 11.90 to 11.10 m bgs), consists of fine, silty and clayey sands with abundant fragments of mollusks shells (su 2a). it attests a short-term episode interrupted by the instauration of a fluvial environment, expressed by gravelly deposits (su 1a). the fossil assemblage suggests a very shallow water, probably referable to a submerged beach environment (interval s2-b). m2-marine infralittoral. rich microfossil assemblages were recovered throughout the s2 succession, from 21 latest pleistocene to holocene environmental changes in southern elba island (italy) fig. 11 classification boxes containing core samples (between 15,00 and 0,00 m bgs) from s2 borehole. legend: f = fluvial deposits; m1 = shallow marine deposits; m2 = marine infralittoral deposits (b1-b3 = biocalcarenite strata); l = brackish lagoon deposits; w = freshwater wetland deposits; a = anthropogenic terrains. 22 d’orefice m. et al. 9.70 to 4.60 m bgs. it consists of sands, silty-clay sands, sand with silty clays and clays with sandy silts which alternate with three biocalcarenite levels: the first one between 9.70 and 9.40 m, the second one between 8.50 and 8.40 m and the third one between 7.50 and 6.30 m bgs (su 2b and lower part of su 3). the higher diversified microfossil assemblages, especially benthonic foraminifers (among the most common: ammonia beccarii, asterigerinata mamilla, elphidium spp. and quinqueloculina spp.) as well as the presence of rare planktonics in all the sample of the interval, attest the instauration of more open marine conditions than the previous interval (m1) and possibly of slightly deeper waters starting from 9.309.40 m bgs, referred to infralittoral environment (interval s2-d). it is interesting to note that, anyway, from s2 5.305.40 m (su 3), significant changes in the assemblages are marked by the appearance, among mollusks, of the genera cerastoderma, abra and hydrobia and among ostracods, of a large number of non-ornamented specimens. vegetal remains are abundant, including fruits of ruppia. 3) brackish lagoon (l) the upper portions of both s2 (from 4.60 to 1.60 m bgs) and s3 (from 13.50 to 12.15 and from 8.30 to 1.60 m bgs) consist of organic clay with sandy silt, dark gray in color and very plastic (su 3), associated to a brackish lagoon environment (backdune) as registered by microfossil assemblages. in s2 the passage from marine (m2) to lagoon environment seems to occur gradually, in continuity of sedimentation. in s3 microfossil assemblages, though rather oligotypic and monotonous support the instauration of a predominantly brackish lagoon environment (intervals s3-b and s3-d). the latter, however, was affected by three alluvial events promoting an increase of the detrital input and the sedimentation of three coarser strata from about 50 cm to 385 cm thick (su 1c). in s2 microfossil assemblages depict a predominantly brackish lagoon environment for a total 2.80 m thickness (interval s2-e), with two short phases of increase of detrital input between 4.35 and 4.65 m and between 3.30 and 3.45 m bgs (su 1c). values up to 24% for amaranthaceae attest the larger expansion of the saltmarsh at ~4 m in s2. 23 latest pleistocene to holocene environmental changes in southern elba island (italy) fig 12 sw-ne transect at marina di campo plain: paleoenvironmental reconstruction and attempt of correlation between s2, s3 and s1 sedimentary cores. the repeated interruptions of the lagoon sedimentation matched pseudoschizaea peaks and strong reduction in the concentration values of palynomorphs. this evidence supports an increase of the erosive processes in the surrounding reliefs, during a phase of reduction of the vegetation cover, with a consequent increase in river sedimentation rates in a brackish lagoon subjected, however, to seasonal drying. 4) freshwater wetlands (w) silt with weakly sandy clay in the topmost portion of both s2 (from 1.60 to 0.50 m bgs) and s3 (from 1.60 to 0.87 m bgs) (su 3) contains only very rare characeae and other abundant vegetal remains typical of freshwater coastal ponds (intervals s2-f and s3-e). cyperaceae values up to 29% in s2 (at 2.10 m bgs) attest the extension of freshwater wetlands. 5.2. main environmental changes on southern elba island during the late quaternary climate and sea level changes played an important role on late quaternary aquatic and terrestrial environments in the central mediterranean (e.g. benjamin et al., 2017; vacchi et al., 2017; 2018; antonioli et al., 2018; sadori, 2018 and references therein). the stratigraphic framework reconstructed for the subsurface of marina di campo area shows remarkable similarities with those from several coeval late quaternary successions in the mediterranean area (see amorosi & milli, 2001 and reference therein). in fact, in spite of modest differences at local level, in the mediterranean coastal areas the sedimentary history of the last 125 kyrs is characterized by a series of transgressiveregressive deposits, generally represented, starting from the oldest ones, by: i) marine sediments of the last interglacial (mis 5.5, highstand system tract hst); ii) alluvial deposits of the last glaciation (mis 4-2, lowstand system tract lst); iii) transgressive and highstand post-glacial alluvial, coastal and marine deposits (trasgressive system tract tst and highstand system tract hst) (zaitlin et al., 1994). at ei, the latest pleistocene phases did not leave evident and continuous sedimentary evidence. this is the case of the tyrrhenian transgression during mis 5.5 which is indeed well attested by marine sediments and platforms along the tuscan peninsular coast and in the neighboring island of pianosa (graciotti et al., 2004; antonioli et al., 2011). in the marina di campo hinterlands as well as in the other coastal plains of elba, fluvial terraces, between 10 and 15 m above sea level, suggest a higher base level than the current one, i.e. a sea level highstand of mis 5.5 (d’orefice & graciotti, 2018). the regressive phases during mis 4 and mis 2 promoted the emersion of the tuscan continental platform including the area in front of marina di campo. sea level was significantly lower (lst) compared to today, of about 80÷90 m during mis 4 and even around 120 m during mis 2 (waelbroeck, 2002; peltier & fairbanks, 2006; lambeck et al., 2011). however, during mis 3 (zecchini, 1981), ei returned, after the previous dominant continental phase during mis 4, to be isolated from the italian peninsula as during the tyrrhenian (mis 5.5). during mis 2 (including the lgm) the tuscan continental platform, almost completely emerged, was deeply incised by a hydrographic network (bianchi, 1943; bartolini et al., 1979), which deepened progressively landward because of upstream knickpoint migration. the incised valleys formed during the phases of relative sea level fall have been widely described in the literature (zaitlin et al., 1994), with particular reference to the late pleistocene glacials (e.g. suter & berryhill, 1985; posamentier & allen, 1999). subsequently, in these wide and deep valleys, predominantly fluvial coarse sediments, many meters thick, were deposited as attested in the subsoil of the marina di campo plain by the lower portion of s1-s4. this is also confirmed by numerous boreholes, reported in bencini et al. (1986), that reached the bedrock at depths even greater than 40 m near the present coastline (see also d’orefice & graciotti, 2018). the considerable availability of sediment from river systems possibly related to the overall decrease in the vegetation cover during prevalent dry conditions. short and intense precipitation events were, in their turn, responsible for a large part of the total sediment transport. the absence of datings does not allow to frame these river deposits in a precise chronological interval. however, according to other regional contributions (e.g. amorosi et al., 2003, 2004; aguzzi et al., 2007; milli et al., 2016) it is conceivable to attribute this sedimentary episode to the late phase of low standing (late lowstand system tract llst) of the late pleistocene. between the end of the pleistocene and the beginning of the holocene sea level rose very quickly (an average rate of rise of 15 m/kyr, lambeck et al., 2002, 2014), leading to a rapid retreat of the coastline. in this context, the transgressive deposits (tst), characterized by marine (s2) and lagoon sediments (s3), mainly including fine sands, sandy silts and clays, overlie with a sharp erosional boundary the alluvial gravels and sands. the erosional boundary and the abrupt facies change, suggest the presence of a significant stratigraphic hiatus due to a prolonged erosive phase. this erosional boundary most likely represents the continuation of the late pleistocene erosive surface, identified by geophysical surveys, in the ei offshore (principi et al., 2015b). a similar erosional surface has also been identified in other italian coastal areas; for example in the upper adriatic (amorosi et al., 1999; 2003; 2004 and references therein) or in the lower plains of the arno (aguzzi et al., 2005; 2007; amorosi et al., 2008; 2009), where, probably, it is associated to a stratigraphic hiatus including the late glacial and part of the holocene. during the early phase of the holocene transgression, in the marina di campo area the sea penetrated inside the pre-existing fluvial valleys, as documented at s2, i.e. the closest site to the current coastline compared to s3, s1 and s4. the last two cores, in fact, include only alluvial deposits (fig. 5) being located in a much more internal position with respect to both s2 and s3. in the study area, the first marine evidence can be placed around 7,000 cal. yr bp on the basis of the ams datings (tab. 1) of the dark organic lagoon silts and clays in s3 (about 135 cm thick between 13.50 and 12.15 m bgs). this level probably correlates with the first evidence of marine deposits (m1, figs. 11, 12), between 24 d’orefice m. et al. 11.90 and 11.10 m bgs in s2. indeed, lagoon deposits at s3 possibly represent the lateral landwards equivalent of s2 marine deposits (fig. 12). holocene fine lagoon deposits, characteristic of a low-energy environment, as before mentioned, overlap the coarser late pleistocene alluvial sediments, attesting a sudden sedimentary environment change at s3. they accumulated inside shallow brackish basins, delimited towards the sea by coastal barriers progressively migrating landward during the phase of post-glacial transgressive sea level rise. the absence of marine deposits in s3 can be justified by its position slightly further from the current coastline than s2. this position, during the holocene transgression, could be even more internal due to a different conformation of the coastline, which probably was more advanced in its northern section than the southern one. the hypothesis now formulated is supported by the presence, behind the northern coast, of a much larger catchment basin. it would have ensured, through its hydrographic network, a greater sediment contribution from the hinterland, determining the more advanced position of the northern coastal sector than the southern one. within the holocene transgressive succession, however, there is a brief regressive episode, attested by fluvial deposits (mainly sandy and silty) in both s2 (between 11.10 and 9.70 m bgs) and s3 (between 12.15 and 8.30 m bgs), which interrupt, respectively, the marine and lagoon sedimentation (fig. 12). this episode can be attributed to a minor oscillation of the sea level, possibly due to a relatively small climate changes (pascucci et al., 2018), between ca 6,600 and 5,800 cal. yr bp in s3. the final phases of the holocene transgression (ca 6,000 cal. yr bp) are marked by a second frankly marine episode (m2). slightly deeper waters, in an infralittoral environment, can be reconstructed starting from 9.309.40 m bgs in s2, especially by fossiliferous sands and silts, interbedded to three biocalcarenite layers. starting from about 6,000 cal. yr bp, the eustatic rise became slower (less than 1 mm/yr), as also recorded throughout the mediterranean (anthony et al., 2014; vacchi et al., 2016; ghilardi et al., 2018; melis et al., 2018), and the highstand sea level (hst) began. during this phase, the sediment input from the hinterland took over the creation of sedimentary space; thus, the progradation towards the sea of coastal and river systems began, with consequent depositional regression of the coastline. in s2 this corresponds to a change in faunistic assemblages attesting a decrease of the sea waters depth and a gradual upwards shift, between 5.40 and 4.60 m bgs, to a full brackish lagoon environment. indeed, above this gradual passage, between 4.60 and 1.60 m bgs, the conditions for the development of permanent lagoons in the areas behind a prograding holocene coastal barrier established near the coast. the most recent evidence of the coastal barrier, consisting of beach and dune ridges, is in external position, in correspondence of the present coastline (fig. 4). in the most internal areas, the hst is expressed, from about 8.00 m bgs in s3, by predominantly clayey sediments which deposited in a lagoon environment. in s1 a decrease in the mechanical energy is attested in fluvial deposits by the reduction in the size of the granulometric fraction, represented by weakly sandy silty clays, between 10.40 and 7.00 m bgs (fig. 5). this level corresponds to lagoon deposits in s3 (fig. 12). in s3 and s2 the lagoon sedimentation ends at 1.60 m bgs, but while in the inland areas (s3) it ends shortly after 4,780 – 4,470 cal. yr bp, in the coastal areas (s2) the lagoon sedimentation persisted until about 1.60 m bgs, at about 1,500-1,400 cal. yr bp (fig. 6). during both tst and hst, the sedimentation in the lagoon was rather discontinuous being affected by frequent interruptions, corresponding to episodes of increase in both solid input and coarser granulometric fraction. lagoons were in fact submitted to seasonal drying after high-energy alluvial events as also attested in the palynological record (pseudoschizaea peaks and decrease of palynomorphs concentration). with the definitive closure of the communication with the open sea, attested by the gradual disappearance of the brackish faunas, the lagoons at marina di campo were progressively transformed into freshwater coastal ponds between the end of roman times (at about 1,500 cal. yr bp) and the early middle ages (<ca 1,300–1,200 cal. yr bp). in these low energy depositional environments silts and dark clays accumulated; abundant plant remains (s2 and s3) were also found. in the areas bordering the ancient coastal ponds, fluvial sedimentation persisted up today conditioning the development of the current alluvial plain. the prevalent sandy and silty fluvial sediments covering to some extent the lagoon and freshwater wetlands ones reducing their areas of outcrop. the pilot palynological approach developed in the frame of the geomorphological map survey, despite still lacking adequate resolution, especially for paleoclimate reconstructions, made possible to furnish some additional and complementary evidence on the depositional environments. investigation in s2 and s3 provides, specifically, some paleovegetational and paleoclimatic spots in the interval extending from the upper portion of the neolithic up to the early middle ages which largely center the period characterized by increasing aridification phenomena (mayewski et al., 2004; jalut et al., 2009; roberts et al., 2011; bini et al., 2019). from about 6,000 years bp repeated phases of enlargement and narrowing of the forest vegetal formations are well evident in both marina del campo records, at s2 and s3 (figs 9, 10). the most recent decrease in tree cover at s2, seems connected to the early stages of increasing human activities related to metallurgy (etruscan civilization). magnetic susceptibility studies in marine cores taken from the area between the elba and corsica islands (vigliotti et al., 2003), documented, in fact, an important metallurgical activity during this time with a maximum peak localized around 2,500 years bp. instead, the low abundance of cultivated taxa (e.g. cereals, vitis, juglans and castanea) leads to the exclusion of intense agricultural exploitation of the area. it is clear that higher resolution palynological analyses, now in progress, are indispensable to document the successive phases of increase / drastic reduction of oak trees (both deciduous and evergreen) or rather of non-arboreal plants, as well as changes in the extension of coastal 25 latest pleistocene to holocene environmental changes in southern elba island (italy) wetlands, characterized by the expansion of marsh or swamps. the occurrence of salt (e.g. as attested by the increase of amaranthaceae in s2 at 4-4.1 m) and/or freshwater (as attested by the increase of cyperaceae at the base of s3 or at the upper portion of s2 and/or alnus) wetlands is also well documented during the lagoon phase development. the new ongoing studies on ei cores, integrated by those from the main italian sites, already known in bibliography (e.g. currás et al., 2017; di rita et al., 2018 and references therein; melis et al., 2018; sadori, 2018), possibly, will lead to a more coherent interpretation and reconstruction of the role played by climate and / or man during this crucial time at the middle-late holocene transition in the central mediterranean area. conclusions the multidisciplinary study of 4 continuous core drillings (s1÷s4) provided the unique opportunity, in absence of sedimentary outcrops, to document the late quaternary sedimentary succession of southern ei. noteworthy, the presence of holocene marine deposits in the subsoil of ei is attested, for the first time. three main depositional phases representing the paleoenvironment response to the glacial-eustatic sea level rise starting from lgm, i.e. 1. low stationing phase (lowstand systems tract lst), 2. transgressive phase (transgressive systems tract tst); 3. high stationing phase (highstand systems tract hst) have been described. lst during the lgm lowstand the continental shelf facing the marina di campo area was completely emerged and strongly carved by the hydrographic network. as a result several tens of meters of coarse river sediments accumulated in these valleys, during the latest pleistocene. tst during the transgressive post-glacial phase, between the end of the pleistocene and the beginning of the holocene, the sea level rising promoted a progressive withdrawal of the coastline, the deactivation of river sedimentation and the migration towards the land of a barrier-lagoon system. in this context, around 7,000 cal. yr bp, in the easternmost sector of the marina di campo plain (which extends from the current coastline up to about 400-500 m landwards) a marine shallow water environment developed. brackish lagoon expanded in the innermost coastal sector, while fluvial environments developed in the upper zones. after a brief regressive episode, between ca 6,600 and 5,800 cal. yr bp, attested by fluvial deposits which interrupt the marine and lagoon sedimentation, a slightly deeper marine environment established in the easternmost sector. in the innermost zones, however, the lagoon sedimentation continues, with some interruptions due to the increase of solid input in the lagoon basins, following high-energy alluvial events. lagoons were in fact submitted to seasonal drying following high-energy alluvial events as also attested in the palynological record (pseudoschizaea peaks and decrease of palynomorphs concentration). hst around 6,000 cal. yr bp, the sediment input from the hinterland takes over the creation of sedimentary space, after the transgressive phase and the start of the highstand sea level. the progradation towards the sea of coastal and river systems begins, with consequent depositional regression of the coastline; brackish lagoon sedimentation extends to the eastern sector before being interrupted by alluvial episodes. between about 1,500 cal. yr bp and approximately 1,300–1,200 cal. yr bp, with the definitive closure of the communication with the open sea, the lagoon areas at marina di campo were progressively transformed into freshwater coastal ponds. in the surroundings of the ancient coastal ponds, fluvial sedimentation persists until today as attested by the current floodplain. this contribution provides a geologicalstratigraphic basis for future research on relevant topics and questions still open concerning especially the: i) stratigraphic relationships and chronology of fluviatile and marine deposits which exhibit a sharp erosive contact. at present the occurrence of unreliable ams datings of marine sediments and the absence of chronological references in fluvial sediments prevent any inferences; ii) reconstruction of landscape modifications induced by humans and/or climate during the last 7,000 years in the mediterranean area, including the documentation of the 4.2 kyr event. multidisciplinary and higher resolution investigations, especially palynological ones, are currently underway at marina di campo and in the plains of magazzini and san giovanni (centralnorthern ei). acknowledges this study was supported by the ispra-geological survey of italy carg project, fondi di ateneo 2010-12 (university of florence, italy) assigned to a. bertini and fondi di ateneo 2010-12 (university of siena, italy) assigned to l. foresi. the authors thank the two anonymous reviewers and paolo mozzi (associated editor at amq) for their careful reading of manuscript and for their helpful comments and suggestions. references agi associazione geotecnica italiana (1977) raccomandazioni sulla programmazione ed esecuzione delle indagini geognostiche. edizioni scientifiche italiane, napoli. aguzzi m., amorosi a., sarti g. (2005) stratigraphic architecture of late quaternary deposits in the lower arno plain (tuscany, italy). geologica romana, 38, 1-10. aguzzi m., amorosi a., colalongo m.l., ricci lucchi m., rossi v., sarti g., vaiani s.c. (2007) late quaternary climatic evolution of the arno coastal plain (western tuscany, italy) from subsurface data. sed. geol., 202, 211-229. amorosi a., milli s. (2001) late quaternary depositional architecture of po and tevere river deltas (italy) and worldwide comparison with coeval deltaic successions. sed. geol., 144, 357-375. 26 d’orefice m. et al. amorosi a., colalongo m.l., pasini g., preti d. (1999) sedimentary response to late quaternary sealevel changes in the romagna coastal plain (northern italy). sedimentology, 46, 99-121. amorosi a., centineo m.c., colalongo m.l., pasini g., sarti g., vaiani s.c. (2003) facies architecture and latest pleistocene-holocene depositional history of the po delta (comacchio area), italy. j. geol., 111, 39-56. amorosi a., colalongo m.l., fiorini f., fusco f., pasini g., vaiani s.c., sarti g. (2004) palaeogeographic and palaeoclimatic evolution of the po plain from 150-ky core records. global planet. change, 40, 55-78. amorosi a., sarti g., rossi v., fontana v. (2008) anatomy and sequence stratigraphy of the late quaternary arno valley fill (tuscany, italy). geoacta, special publication 1, 117-129. amorosi a., ricci lucchi m., rossi v., sarti g. (2009) climate change signature of small-scale parasequences from lateglacial–holocene transgressive deposits of the arno valley fill. palaeogeography, palaeoclimatology, palaeoecology, 273, 142-152. amorosi a., bini m., fabiani f., giacomelli s., pappalardo m., ribecai c., ribolini a., rossi v., sammartino i., sarti, g. (2012) mappa cores: an interdisciplinary approach. mappapers 4en-ii, 149-200. https://www.mappaproject.org/report-di-progetto/? lang=en amorosi a., bini m., giacomelli s., pappalardo m., ribecai c., rossi v., sammartino i., sarti g. (2013) middle to late holocene environmental evolution of the pisa coastal plain (tuscany, italy) and early human settlements. quaternary international, 303, 93-106. anthony e.j., marriner n., morhange c. (2014) human in�uence and the changing geomorphology of mediterranean deltas and coasts over the last 6000 years: from progradation to destruction phase? earth sci. rev., 139, 336-361. antonioli f., amorosi a.m., correggiari a., doglioni c., fontana a., fontolan g., furlani s. ruggieri spada g. (2009a) relative sea-level rises and asymmetric subsidence in the northern adriatic. rendiconti online soc. geol., 34-36. antonioli f., ferranti l., fontana a., amorosi a.m., bondesan a., braitenberg c., dutton a., fontolan g., furlani s., lambeck k., mastronuzzi g., monaco c., spada g., stocchi p. (2009b) holocene relative sea-level changes and vertical movements along the italian coastline. quaternary international, 221, 37-51. antonioli f., d’orefice m., ducci s., firmati m., foresi l.m., graciotti r., perazzi p., pantaloni m., principe c. (2011) palaeogeographic reconstruction of northern tyrrhenian coast using archaeological and geomorphological markers at pianosa island (italy). quaternary international, 232, 31 44. antonioli f., ferranti l., stocchi p., deiana g., lo presti v., furlani s., marino c., orru p., scicchitano g., trainito e., anzidei m., bonamini m., sansò p., mastronuzzi g. (2018) morphometry and elevation of the last interglacial tidal notches in tectonically stable coasts of the mediterranean sea. earth-science reviews, 185, 600-623. bartolini c., fanucci f., gabbani g., rossi s., valleri g., lenaz r. (1979) studio della piattaforma continentale medio-tirrenica per la ricerca di sabbie metallifere: 2) dall'isola d'elba a livorno. boll. soc. geol. it., 98, 327-352. bellotti p., calderoni g., dall’aglio p.l., d’amico c., davoli l., di bella l., d’orefice m., esu d., ferrari k. bandini mazzanti m., mercuri a.m., tarragoni c., torri p. (2016) middle-to late holocene environmental changes in the garigliano delta plain (central italy): which landscape witnessed the development of the minturnae roman colony? the holocene, 26 (9), 1457-147. bencini a., giardi m., pranzini g., tacconi b.m. (1986) le risorse idriche dell’isola d’elba. quaderni sull’assetto del territorio della provincia di livorno, nuova serie, 2, 91, tacchi editore, pisa. benjamin j., rovere a., fontana a., furlani s., vacchi m., inglis r.h., galili e., antonioli f., sivan d., miko s., mourtzas n., felja i., meredith-williams m., goodman-tchernov b., kolaiti e., anzidei m., gehrels r. (2017) late quaternary sea-level changes and early human societies in the central and eastern mediterranean basin: an interdisciplinary review. quaternary international, 449, 29-57. bini m., brückner h., chelli a., pappalardo m. (2010) first remarks on the late holocene relative sea level from sedimentological palaeo sea level indicators in the lower magra valley coastal plain. rendiconti online società geologica italiana, 11 (1), 34-35. bini m., pappalardo m., rossi v., noti v., amorosi a., sarti g. (2018) deciphering the effects of human activity on urban areas through morphostratigraphic analysis: the case of pisa, northwest italy. geoarchaeology, 33(1), 43-51. bini m., zanchetta g., per�oiu a., cartier r., català a., cacho i., dean j.r., di rita f., drysdale r.n., finnè m., isola i., jalali b., lirer f., magri d., masi a., marks l., mercuri a.m., peyron o., sadori l., sicre m.-a., welc f., zielhofer c., brisset e. (2019) the 4.2 ka bp event in the mediterranean region: an overview. clim. past, 15, 555-577. bianchi e. (1943) alcuni effetti delle oscillazioni eustatiche del livello marino sulla morfologia dell’elba orientale. atti soc. tosc. sc. nat. mem. pisa, 52 (2), 23-36. blum m.d., törnqvist t.e. (2000) fluvial responses to climate and sea-level change: a review and look forward. sedimentology, 47(suppl. 1), 2-48. bortolotti v., pandeli e., principi g. (con il contributo di d’orefice m. & graciotti r.) (2015) note illustrative della carta geologica dell’isola d’elba scala 1:25.000. dream. italia. boyer j., duvail c., le strat p., gensous b., tesson m. (2005) high resolution stratigraphy and evolution of the rhône delta plain during postglacial time, from subsurface drilling data bank. mar. geol., 222 -223, 267-298. 27 latest pleistocene to holocene environmental changes in southern elba island (italy) bronk ramsey c. (2008) deposition models for chronological records. quaternary science reviews, (1-2), 42-60. bronk ramsey c. (2009) bayesian analysis of radiocarbon dates. radiocarbon, 51, 337-360. bronk ramsey c., lee s. (2013). recent and planned developments of the program oxcal. radiocarbon, 55 (2-3), 720-730. brückner h., vött a., schriever a., handl m. (2005) holocene delta progradation in the eastern mediterranean case studies in their historical context. mediterranée. 104, 95-106. clark p.u., dyke a.s., shakun j.d., carlson a.e., clark j., wohlfarth b., mitrovica j.x., hostetler s.w., mccabe a.m. (2009) the last glacial maximum. science, 325, 710-714. currás a., ghilardi m., peche-quilichini k., fagel n., vacchi m., delanghe d., dussouillez p., vella c., bontempi j.m., ottaviani j.c. (2017) reconstructing past landscapes of the eastern plain of corsica (nw mediterranean) during the last 6000 years based on molluscan, sedimentological and palynological analyses. journal of archaeological science: reports, 12, 755-769. di rita f., fletcher w.j. aranbarri j., margaritelli g., lirer f., magri d. (2018) holocene forest dynamics in central and western mediterranean: periodicity, spatio-temporal patterns and climate influence. scientific reports, 8(1), n. 8929. dini a., innocenti f., rocchi s., tonarini s., westerman d.s. (2002) the magmatic evolution of the late miocene laccolith-pluton-dyke granitic complex of elba island, italy. geol. mag., 139, 257-279. d’orefice m., graciotti r. (2008) aspetti geomorfologici e sedimentologici dei depositi eolici del settore occidentale del promontorio del calamita (isola d’elba). atti del convegno in memoria di lamberto pannuzi, rossano 19-21 maggio 2005. mem. descr. carta geologica d’italia, 78, 113-126. d’orefice m., graciotti r. (2015) rilevamento geomorfologico e cartografia: realizzazione, lettura, interpretazione. dario flaccovio editore s.r.l., pp. 360, palermo. d’orefice m., graciotti r. (eds.) (2018) note illustrative della carta geomorfologica d’italia alla scala 1.50.000, fogli 316-317-328-329 “isola d’elba”. serv. geol. d’it. ispra, pp. 224. d’orefice m., graciotti r., capitanio f. (2007) le eolianiti dell’isola d’elba: i depositi del promontorio del m. calamita e del golfo di viticcio. il quaternario, 20 (1), 21-44. d’orefice m., foresi m.l., graciotti r. (2011) first recovery of marine quaternary deposits from geognostic boreholes of the coastal plain of marina di campo (elba island): preliminary results. il quaternario, 26 (abstract aiqua, roma, 02/2011), 29-31. douka k., higham t. f. g., hedges r. e. m. (2010) radiocarbon dating of shell carbonates: old problems and new solutions. munibe suplemento gehigarria 31, 18-27. fedi m., cartocci a., manetti m., taccetti f., mandò p.a. (2007) the 14c ams facility at labec, florence, nucl. instr. meth. b 259, 18-22. ferranti l., antonioli f., amorosi a., dai prà g., mastronuzzi g., mauz b., monaco c., orrù p., pappalardo m., radtke u., renda p., romano p., sansò p., verrubbi v. (2006) elevation of the last interglacial highstand in italy: a benchmark of coastal tectonics. quaternary international, 145,146, 3054. ferranti l., antonioli f., anzidei m., monaco c., stocchi p. (2010) the timescale and spatial extent of vertical tectonic motions in italy: insights from relative sea-level changes studies. journal of the virtual explorer, electronic edition, issn 1441-8142, 36, paper 30. forzoni a., storms j. e. a., reimann t., moreau j., jouet, g. (2015) non-linear response of the golo river system, corsica, france, to late quaternary climatic and sea level variations. quaternary science reviews, 121, 11-27. ghilardi m., vacchi m., currás a., müller celka s., theurillat t., lemos i., pavlopoulos k. (2018) géoarchéologie des paysages littoraux le long du golfe sud�eubéen (île d’eubée, grèce) au cours de l’holocène. quaternaire, 29(2), 95-120. gischler e., gibson m. a., oschmann w. (2008) giant holocene freshwater microbialites, laguna bacalar, quintana roo, mexico. sedimentology, 55, 1293-1309. graciotti r., foresi l., pantaloni m. (2004) lineamenti geomorfologici dell’isola di pianosa. soc. tosc. scien. nat. atti serie a, 108, 95-111. green o.r. (2001) washing and sieving techniques used in micropalaeontology. in: a manual of practical laboratory and field techniques in palaeobiology. springer, dordrecht, 146-153 ispra-servizio geologico d’italia (2015) carta geologica d’italia alla scala 1:50.000 fogli 316-317328-329 “isola d’elba”. h t t p : / / w w w . i s p r a m b i e n t e . g o v . i t / m e d i a / carg/328_isola_delba/foglio.html ispra-servizio geologico d’italia (2018) carta geomorfologica d’italia alla scala 1:50.000. foglio 316317-328-329 “isola d’elba”. ispra-servizio geologico d’italia. jalut g., dedoubat j.j., fontugne m., otto t. (2009) holocene circum-mediterranean vegetation changes: climate forcing and human impact. quaternary international, 200, 4-18. lambeck k., purcel a. (2004) sea-level change in the mediterranean sea since the lgm: model predictions for tectonically stable areas. quaternary science reviews, 24, 1969-1988. lambeck k., yokoyama y., purcell t. (2002) into and out of the last glacial maximum: sea-level change during oxygen isotope stages 3 and 2. quaternary science reviews, 21, 343-360. lambeck, k., antonioli, f., anzidei, m., ferranti, l., leoni, g. (2011) sea level change along italian coast during holocene and a projection for the future. quaternary international, 232 (1-2), 250257. 28 d’orefice m. et al. lambeck k., rouby h., purcel a., yiying s., sambridge m. (2014) sea-level and global ice volumes from last glacial maximum to the holocene. pnas, 111(43), 15296-15303. maineri c., benvenuti m., costagliola p., dini a., lattanti p., ruggieri g., villa i. m. (2003) sericitic alteration at the la crocetta deposits (elba island, italy): interplay between magmatism, tectonic and hydrotermal activity. mineralium deposita, 38, 6786. mayewski p.a., rohling e.e., stager j.c., karlen w., maasch k.a., meeker l.d., meyerson e.a., gasse f., van kreveld s., holmgren k., leethorp j., rosqvist g., rack f., staubwasser m., schneider r.r., steig e.j. (2004) holocene climate variability. quaternary research, 62, 243255. melis r.t., depalmas a., di rita f., montisa f., vacchi m. (2017) mid to late holocene environmental changes along the coast of western sardinia (mediterranean sea). glob. planet. chang., 155, 29-41. melis r. t., di rita f., french c., marriner n., montis f., serreli g., sulas f., vacchi m. (2018) 8000 years of coastal changes on a western mediterranean island: a multiproxy approach from the posada plain of sardinia. marine geology, 403, 93-108. milli s., mancini m., moscatelli m., stigliano f., marini m., cavinato g.p. (2016) from river to shelf, anatomy of a high-frequency depositional sequence: the late pleistocene to holocene tiber depositional sequence. sedimentology, 63, 18861928. pascucci v., de falco g., del vais c., sanna i., melis r.t., andreucci s. (2018) climate changes and human impact on the mistras coastal barrier system (w sardinia, italy). mar. geol., 395, 271-284. peltier, w.r., fairbanks, r.g. (2006) global glacial ice volume and last glacial maximum duration from an extended barbados sea level record. quaternary science reviews, 25, 3322-3337. posamentier h.w., allen g.p. (1999) siliciclastic sequence stratigraphy concepts and applications. soc. econ. paleontol. miner., concepts in sedimentology and paleontology, 7, pp. 204. posamentier h.w., jervey m.t., vail p.r. (1988) eustatic controls on clastic deposition i: conceptual framework. in: sea level changes: an integrated approach (ed. by wilgus c.k., hastings b.s., kendall c.g.st.c., posamentier h.w., ross c.a., van wagoner j.c.). sepm special publication, 42, 109-124. principi g., bortolotti v., pandeli e., fanucci f., moretti s., innocenti f., d’orefice m., graciotti r. (2015a) carta geologica dell’isola d’elba scala 1:25.000. dream. italia. principi g., fanucci f., bortolotti v., chiari m., dini a., fazzuoli m., menna f., moretti s., nirta g., pandeli e., reale v. (2015b) note illustrative della carta geologica d’italia alla scala 1:50.000 fogli 316-317-328-329 “isola d’elba”. ispradipartimento difesa del suolo-servizio geologico d’italia. http:/ /www.isprambiente.gov.i t /media/carg/ note_illustrative/328_isola_delba.pdf reimer p.j., bard e., bayliss a., beck j. w., blackwell p.g., bronk ramsey c., grootes p.m., guilderson t.p., haflidason h., hajdas i., hatté c., heaton t.j., hoffmann d.l., hogg a.g., hughen k.a., kaiser k.f., kromer b., manning s.w., niu m., reimer r.w., richards d.a., scott e.m., southon j.r., staff r.a., turney c.s. m., van der plicht j. (2013) intcal13 and marine13 radiocarbon age calibration curves 0-50,000 years cal bp. radiocarbon, 55(4), 1869-1887. roberts n., brayshaw d., kuzucuo�lu c., perez r., sadori l. (2011) the mid-holocene climatic transition in the mediterranean: causes and consequences. the holocene, 21(1), 3-13. sadori l. (2018) the lateglacial and holocene vegetation and climate history of lago di mezzano (central italy). quaternary science reviews, 202, 30-44. saupé p., marignac c., moine b., sonet j., zimmerman j.l. (1982) datation par les méthodes k/ar et rb/ sr de quelques roches de la partie orientale de l’ile d’elbe (province de livourne, italie). bull. mineral., 105, 236-245. siddall m., rohling e.j., almogi-labin a., hemleben c., meischner d., schmelzer i. (2003) sea level fluctuations during the last glacial cycle. nature, 423, 853-858. suter j. r., berryhill h.l. (1985) late quaternary shelfmargin deltas, northwest gulf of mexico. aapg bulletin, 69(1), 77-91. vacchi, m., marriner, n., morhange, c., spada, g., fontana, a., rovere, a. (2016) multiproxy assessment of holocene relative sea-level changes in the western mediterranean: sea-level variability and improvements in the de�nition of the isostatic signal. earth sci. rev., 155, 172-197. vacchi m., ghilardi m., spada g., currás a., robresco s. (2017) new insights into the sea-level evolution in corsica (nw mediterranean) since the late neolithic. j. archaeol. sci., report 12, 782-793. vacchi m., ghilardi m., melis r.t., spada g., giaime m., marriner n., lorscheid t., morhange c., burjachs f., rovere a. (2018) new relative sea-level insights into the isostatic history of the western mediterranean. quaternary science review, 201, 396-408. vigliotti l., roveri m., capotondi l. (2003) etruscan archaeo-metallurgy record in sediments from the northern tyrrhenian sea. journal of archaeological science, 30, 809-815. zaitlin b.a., dalrymple r. w., boyd r. (1994) the stratigraphic organization of incised-valley systems associated with relative sea-level change. in: incised-valley systems: origin and sedimentary sequences (ed. by dalrymple r.w., boyd r. & zaitlin b.a.). soc. econ. paleontol. mineral., spec. publ., 51, 45-60. zecchini m. (1981) l’isola d'elba dal paleolitico all’epoca romana. in: “studi sul territorio livornese: archeologia, antropologia, geologia” a cura del centro livornese di studi archeologici. editrice 29 latest pleistocene to holocene environmental changes in southern elba island (italy) la fortezza, livorno, 155-191. waelbroeck c., labeyrie l., michel e., duplessy j.-c., mcmanus j., lambeck k., balbon e., labracherie m. (2002) sea-level and deep water temperature changes derived from benthic foraminifera isotopic records. quaternary science review 21, 295-305. 30 d’orefice m. et al. ms. received: march 21, 2019 revised: january 21, 2020, accepted: january 22, 2020 available online: january 29, 2020 amq 31(1) 21-35 giraudi proofcopy available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 31 (1), 2018, 21 35 the pliocene and early pleistocene drainage network evolution in the monferrato hills (piedmont, nw italy) carlo giraudi enea c.r. saluggia, saluggia (vc), italy corresponding author: c. giraudi <giraudic@libero.it> abstract: the drainage network in the monferrato hills is, in general, quite complex. however, in the western and eastern end of the monferrato there are areas where the drainage is less complex. morphological analysis suggests that the differences in drainage were mainly produced by captures that have affected the catchments of some streams. geological and geomorphological studies have shown that during the early pliocene, a portion of the monferrato, along with part of the torino hill, was an island in which there were some catchment basins draining towards the southern and northern sea. the tectonic evolution caused the capture of rivers that have been dated from the piacenzian onwards using stratigraphic and morphological data. the head of the stura, colobrio, rotaldo and grana valleys, that flowed southwards after the emersion of the island, were captured by headward erosion of streams draining towards the northern basin. the post-zanclean uplift of the western monferrato, some gentle post-zanclean anticlines lying south of the hills, the subsiding basin lying north and the tectonic structures transversal to the monferrato thrust front, played a dynamic role in the evolution of the drainage. on the contrary, the tectonic structures displacing the sediments that form the core of the monferrato hills, active mainly before the pliocene, influenced, mostly passively, the drainage network when the area emerged from the sea. in fact, the initial direction of the streams was conditioned by the different strike, dip and erodibility of the pre-pliocene sediments. keywords: structurally-controlled drainage network, river capture, pliocene, pleistocene, monferrato hills, nw italy 1. introduction the present paper deals with the pliocene-early pleistocene evolution of the drainage network of the monferrato hills. since the paper by sacco (1889), it has been known that during the pliocene the monferrato was an island, and therefore the study of the present drainage network can highlight the structure of the drainage that developed on the just emerged island and the influence of the pliocene and pleistocene tectonic activity on its evolution. the monferrato and torino hills are the northwestern termination of the apennine chain, and are surrounded by the savigliano and alessandria basins, to the south, and by the po basin to the north (fig. 1). the post-messinian geological and tectonic evolution of the hills can be considered fairly similar (irace, 2009; mosca et al., 2010). the drainage network in the monferrato and torino hills is formed by small streams, that are tributaries of the po river north and sw of the hills, and of the tanaro river south of the hills. in the monferrato, the drainage is far more complex than in the torino hills. the geological literature reports various hypotheses regarding the evolution of some portions of the drainage network (biancotti & franceschetti, 1979; carraro et al., 1980; giraudi, 1981; carraro & valpreda, 1991; carraro et al., 1995; dela pierre et al., 2003b; forno & lucchesi, 2005; vezzoli et al., 2010; giraudi, 2015; forno & lucchesi, 2016): the picture that emerges from the morphology of the valleys, the presence of fluvial sediments of alpine origin and the deformation of plio-pleistocene sediments and terraces is clear in indicating that the drainage is strongly influenced by the tectonic evolution connected with the activity of the monferrato thrust front and some transverse strike slips or transtensive faults and deformation zones. the aim of the present paper is to analyze and discuss the morphology of the valleys of the main streams of the monferrato hills in order to recognize the features that originated during the pliocene and the evolution of the drainage network until the early pleistocene, and to hypothesize the forcing factors. 2. material and methods in the present paper it is assumed that, as suggested by the results of the studies of sacco (1889), carraro et al. (1980) and dela pierre et al. (2003a,b), the hills bounded by pliocene sediments of littoral facies indicate approximately the extent of the land surrounded by the sea during the pliocene, in particular during the https://doi.org/10.26382/amq.2018.02 22 giraudi c. zanclean. the stratigraphy and tectonic structures affecting the monferrato hills have been outlined because of their possible impact on the drainage evolution and some interpretations of peculiar geological and morphological features have been discussed. the geology of the area drawn in fig. 2 is based on the geological map of italy at the scale of 1:100,000, sheets 57, 58, 69 and 70 (anfossi et al., 1969; boni & casnedi, 1969; bonsignore et al., 1969; bortolami et al., 1969; braga & ragni, 1969; corsi et al., 1969; montrasio et al., 1969). in fact, only part of the monferrato lies in the trino sheet of the geological map of italy at the scale 1: 50,000 (dela pierre et al., 2003a), which represents an advancement in both the cartography and the interpretation of the stratigraphic and tectonic evolution. however, some tectonic structures identified by dela pierre al. (2003a) and the fontanetto po, trino, salera line, giarole-lu and valenza deformation zones, evidenced by giraudi (2014; 2015; 2016), have been included in fig. 2. the evolution of the drainage network of the monferrato hills was outlined using geomorphological analysis. some morphological features have been used in order to identify areas in which the drainage network has the same characters. the presence of elbows of capture, mostly already reported in literature (biancotti & franceschetti, 1976; carraro et al., 1995; dela pierre et al., 2003; giraudi, 2015; 2016), and strong valley asymmetries have been taken into account in order to establish the most important drainage variations. the drainage network has been interpreted in order to determine the approximate location of the pliocene divide between basins draining to the south and to the north and in order to have some information on the pliocene landscape that was later modified by the geological and geomorphological evolution. 3. geological outline of the hills and buried monferrato detailed knowledge of the geological features of the monferrato hills is limited by the extensive vegetation cover and the scarcity of outcrops. paradoxically, there are more detailed data on tectonic structures that affect the tertiary sediments covered by alluvial deposits of the po plain (the buried monferrato) thanks to the geophysical data and the extensive outcrops along the po riverbed. the geological structure of the monferrato is outlined in fig. 2. 3.1. the monferrato hills the current geological structure of the monferrato hills was determined by the pliocene and pleistocene northward migration along thrust fronts of tertiary sedimentary units already deformed by earlier tectonic phases (dela pierre et al., 2003a,b; galadini et al., 2012; giraudi, 2014; 2015) and by an uplift that lasted, at least in some places, until the late pleistocene (carraro et al., 1980; carraro & valpreda, 1991; carraro et al., 1995; michetti et al., 2012; giraudi, 2014; 2015). according to several authors (costa, 2003; giraudi, 2014; 2016), the thrust front is intersected by transverse strike slip or transtensive faults and deformation zones. the thrust front, buried under quaternary fluvial sediments, is located at a variable distance from the northern slope of the monferrato and torino hills. in general, the core of the monferrato hills consists of strongly deformed pre-messinian sediments and is bounded to the south by gently folded messinian and pliocene sediments. the new stratigraphic studies reported in dela pierre et al. (2003b) have led to the recognition of sediments of littoral facies, pliocene (zanclean) in age, and have demonstrated that, after the zanclean, a marine regression began. the area surrounded by the zanclean sediments corresponds, at least approximately, to the area not submerged by the sea during that period. however in the moncalvo area (fig. 2) there are two small anticlines affecting messinian and pliocene sediments and the pliocene that completely surround the messinian core (sacco, 1889). the post-zanclean anticlines (pieri & groppi,1981; cassano et al., 1986), create a unique case in monferrato, where the messinian sediments always surround unconformably the older marine formations. near san salvatore, the marine sedimentary sequences do not contain the ligurian units, outcropping fig. 1 geological sketch of the monferrato and torino hills and surrounding pliocene basins, with location of the study area. 23 the pliocene and early pleistocene drainage network evolution in the monferrato hills ... in other areas of the monferrato (fig. 2), and the anticline that forms the core of the hills consists of continental and marine messinian and early pliocene marine sediments. elsewhere, except in the moncalvo area, messinian and pliocene sediments outcrop just on the edge of the highest hills. on the northern slope of the hills west of casale monferrato, near verrua savoia, there is just an isolated outcrop of pliocene (zanclean) sediments (martinis, 1954, zappi, 1960; trenkwalder & violanti, 2001; bove forgiot et al., 2005). in the eastern monferrato, between casale monferrato and conzano, pliocene marine littoral sediments are quite extensive and indicate the approximate boundary of the emerged land. regarding the tectonic features, it can be observed that the hills west of the grana valley consist of a series of uplifted complex structures and synclines oriented mainly nw-se and wnw-ese, although some structures lying in the northern portion of the area are oriented approximately w-e and, seldom, sw-ne and approximately n-s. while many of the sediments that form the core of the monferrato hills were already folded and faulted before the pliocene, and partly emerged during the zanclean, the area south of moncalvo, where the anticlines fig. 2 geological map of the monferrato hills (modified from anfossi et al., 1969; boni and casnedi, 1969; bonsignore et al., 1969; bortolami et al., 1969; braga and ragni, 1969; corsi et al., 1969; montrasio et al., 1969). some faults are from dela pierre et al. (2003), while the fontanetto po, trino, salera line, giarole-lu and valenza deformation zone are from giraudi (2014; 2015; 2016). rit, rio, rim and rip indicate the isolated hills of trino, occimano, mirabello and pomaro. with a messinian core involving pliocene littoral sediments are located, was deformed and uplifted later (sacco, 1889; pieri & groppi, 1981; cassano et al., 1986). according to dela pierre et al. (2003b), tectonic movements started during the sedimentation of the deposits of villafranchian facies (piacenzian in age) and caused the uplift of part of the area between moncalvo and asti. also the anticlines that involve messinian and early pliocene marine sediments forming the core of the highest hills near san salvatore were produced by tectonics active during or after the pliocene. according to enel (1984) these sediments lie on a thrust front and their displacement occurred after the lower-middle pliocene. therefore, the deformation of the pliocene marine sediments and the emersion of the areas near moncalvo and san salvatore probably took place at the same time after the zanclean, while the sea was still present in the alessandria and po basins. because the emersion occurred later than in the core of the monferrato, this area from now on will be called neo-monferrato. in the lower cerrina valley (fig. 2) there is a very peculiar syncline, whose axis runs first from nw to se, then w-e and afterwards s-n. the stretch of the syncline oriented nw-se might correspond to the continuation of the syncline having the same direction which extends from the area of cereseto to treville and roncaglia. the syncline of the cerrina valley was also active from the early pleistocene (or late pliocene) to the middle pleistocene and (according to giraudi, 2016) may correspond to a subsiding basin produced by the distension that occurred behind the thrust front (fig. 2) located north of the trino isolated hill (rit in figures). in correspondence with the giarole-lu deformation zone (gldz), some diapiric structures, with wnwese oriented axes, are folded (fig. 2), assuming a swne trend. between the san salvatore area and the pomaro isolated hill (rip in figures), the folds assume a wnw-ese direction and then, at the eastern end of the monferrato, in correspondence with the valenza deformation zone (vdz), a direction approximately n-s. the lithology of the tertiary sediments of the monferrato is predominantly marly and clayey, but the pliocene marine sediments have sandy and calcarenitic facies, the miocene ones contain interbedded calcarenitic horizons and sandstones, while very cemented conglomerates and sandstones are common in the oligocene sediments. in particular, the latter, which generally form the highest hills, are the most resistant to erosion (fig. 2). in the core of the monferrato hills, continental sediments older than the late pleistocene are scarce and outcrop in a patchy fashion, with the exception of the cerrina valley. some alluvial sediments, probably pliocene in age, lie in the area east of the colobrio valley, at an elevation similar to the hilltop, many tens of metres above the lake sediments outcropping in the cerrina valley, dated at the early pleistocene sub-chron olduvai (giraudi, 2016). characteristic of the lower cerrina valley (fig. 2) is the presence of a significant amount of early and middle pleistocene alluvial sediments, formed by clasts of alpine origin, demonstrating the presence of a river flowing from the area sited nw of the valley head (giraudi, 1981; carraro et al., 1995; giraudi et al., 2003; dela pierre et al., 2003a,b; giraudi, 2016). the lithology of some patches of alluvial sediment suggest that the river continued se of the valley reaching the buried monferrato lying north of the easternmost monferrato hills (enel, 1984; carraro et al., 1995; giraudi, 2015; 2016). 3.2. buried monferrato the buried monferrato, located north of the hills between the hill slope and the thrust front, is mainly formed by the same pre-pliocene marine sediments forming the hills, underlying late early pleistocene to holocene fluvial and glaciofluvial deposits of the po plain (enel, 1984; dela pierre et al., 2003 a, b; giraudi, 2014) which, normally, are less than 20 m thick. the marine sediments have been observed in a number of wells and boreholes drilled for oil exploration, or related to studies for a nuclear power plant, and water wells (enel, 1977; 1984; pieri & groppi, 1981; cassano et al., 1986; giraudi, 2014; 2016). pliocene and pleistocene (gelasian) marine deposits of littoral facies have been found not only in the po and the alessandria basins at the top of a thick successions of older pliocene sediments, but also in some places in the buried monferrato lying unconformably on older pliocene neritic and pre-pliocene marine sediments (fig. 2). in general, in the buried monferrato, the pliocene marine sediments lie near the thrust fronts, but north of the eastern monferrato they have been found between the hillside and the pomaro isolated hill, i.e. in an area well south of the monferrato thrust front (pieri & groppi, 1981; cassano et al., 1986). the tectonic structures affecting the buried monferrato, shown in fig. 2, take into account mainly synclines, thrust fronts, faults and deformation zones active also during the pleistocene and which fit better with borehole and well data already discussed in giraudi (2016). in point of fact, such structures could have conditioned the early pleistocene drainage evolution on the buried monferrato. therefore, some thrust fronts active before the late pliocene or of uncertain activity, assumed in geological literature (montrasio et al., 1969; pieri & groppi, 1981; enel, 1984a; cassano et al., 1986; bigi et al., 1990; michetti, et al., 2013; giraudi, 2014; 2015; 2016) have not been drawn in the figure. the area of the buried monferrato (fig. 2) is affected by strike-slip or transpressive faults transverse to the front (costa, 2003) both in the areas west and east of the trino and pomaro isolated hills. according to recent studies (giraudi, 2014; 2015; 2016) in places roughly corresponding to the transpressive faults reported by costa (2003), but also in other areas, there are the fontanetto po (fpdz), trino (tdz), salera line (sldz), giarole-lu (gldz) and valenza (vdz) deformation zones. the deformation zones, active during the pliocene, early and middle pleistocene, are transverse to the thrust fronts, and show left-slip west of the trino and pomaro isolated hills, and rightslip to the east. 24 giraudi c. 3.3. connection between topography of the hills and tectonic structures the connections between the topography and the geological structures seem very clear in the core of the hills. the map of fig. 3 shows the elevations of the study area with 50 m contour lines. the maximum elevations, just below 500 m a.s.l., are reached towards the western end of the area. in the same area the height of the hills often exceeds 400 m a.s.l. the elevations decrease from nw to se. from a comparison between fig. 2 and fig. 3, it is evident that the maximum elevations coincide with the uplifted complex structures and the lower ones with the synclines. it is also easy to observe that the hills lying ne of the head of the stura, grana and rotaldo valleys are, in general, higher than those lying sw and that, just after changing their direction from nw-se and wnwese towards ne, the same valleys lie on sw-ne trending faults and cut deeply through the uplifted structures oriented nw-se (fig. 2). making a comparison between the maximum heights of the hills and the portions where the zanclean sediments of littoral facies are present, next to the divide between the po and the tanaro basins (fig. 3), the difference is of about 100 m in both the western monferrato (400-440 m and 330 m respectively) and the eastern monferrato (250-260 m and 160 m). in fig. 3 it can be observed also that east of moncalvo, the pliocene littoral sediments outcropping north of the potanaro divide sometimes reach elevations higher than the hills forming that divide, but do not reach the elevation of the northernmost hills. 4. preliminary data on the drainage network in the monferrato and torino hills the torino and monferrato hills are affected by a drainage network with different characteristics (fig. 4a). all the streams on the northern slopes are tributaries of the po river , while the streams that drain the southern slopes flow into two different basins: from the torino hills they flow mostly to the e-w trending river banna, which is a tributary of the po, while those draining the monferrato flow to the w-e trending tanaro river or the triversa stream, its tributary. north of the hills, the po river and the small streams flow through the buried monferrato. the drainage network in the hills is shown in fig. 4a. it can be observed that the smaller streams flowing from the hills to the po river are sometimes not drawn in the figures when they reach the alluvial plain. these streams are in fact connected with the network of irrigation ditches and therefore are difficult to follow and their shape and direction are wholly artificial. in the context of fig. 4a, various areas have been highlighted in which the drainage has common features. zone a: corresponds to the torino hills and the portion of monferrato located w and sw of the confluence of the river dora baltea and the river po. the drainage network in this zone has, in general, the following characteristics: the head of the basins of most streams begins at the divide between the northern and southern slopes of the hills, and the streams, with directions transverse to the divide, flow directly into the river po (to the north) or into other streams roughly flowing e-w or w-e, tributaries of the main 25 the pliocene and early pleistocene drainage network evolution in the monferrato hills ... fig. 3 elevations of the monferrato hills and of the surrounding plains, evidenced by 50 m contour lines, and elevation of the pliocene littoral sediments north and south of the po-tanaro divide. rivers (to the south). in zone a, the po-tanaro divide reaches its northernmost point. to the north of the hills, the river po runs close to the hillslope, on the buried monferrato, where tertiary sediments are predominantly pre-pliocene. studies conducted by forno & lucchesi (2005; 2016) in the torino hills indicate the presence of small remnants of terraces on the nw and n hillside. the terraces and the lithology of the alluvial sediments suggest that, in the period between the middle pleistocene and the present time, the drainage at the margin of the hills migrated towards n and nw. zone a1: corresponds to the eastern end of the monferrato. its drainage is similar to that of the zone a, and the head of most basins reaches the divide between the northern and southern slopes of the hills, that is, the po-tanaro divide. the streams have a direction roughly transverse to the divide and flow directly into the po and the tanaro rivers. zone b: corresponds to most of the monferrato hills, except at its western and eastern ends. starting from the western edge of zone b, the po-tanaro divide heads southeast. only the head of the valleys of three streams (stura, colobrio, grana), pertaining to the po basin, reaches the po-tanaro divide. at first, the streams run nw-se or wnw-ese, parallel to the divide, but at some point they abruptly change direction, flowing generally towards n and ne and reach the po river. other small streams lying at the northern slope of the hills flow directly into the po river. in the tanaro basin, several streams having catchments that reach the divide flow into the versa, a tributary of the tanaro, in the area where the stream runs nw-se and therefore is parallel to the divide. on the buried monferrato, the streams are sub-parallel to each other. zone c: includes the hills between the town of valenza and the grana valley. the head of the small catchment basins reaches the po-tanaro divide and the direction of the streams is generally transverse to that of the divide. in the hills the drainage pattern is similar to that of the a1 zone, but on the buried monferrato the streams are sub-parallel to each other and do not drain directly into the po but flow into other tributary streams of the po. the streams of the southern slope of the hills drain directly into the tanaro. in fig. 4b, it can be observed that the boundaries between the a, b, c and a1 zones correspond to or are located in the vicinity of some deformation zones: the rio freddo deformation zone between a and b, the giarole-lu deformation zone between b and c, and the valenza deformation zone between c and a1. the a, a1, b and c zones correspond, roughly, to portions of the hills having different geological features. the portion of the monferrato hills where the drainage is more complex (zones b and c) will be discussed and interpreted below. 5. the drainage network in the monferrato hills the characteristics of the monferrato drainage network have already been partially discussed in a number of papers. one of the major basins, that of the stura stream, was studied by biancotti & franceschetti (1979). also dela pierre et al. (2003b) discussed the characteristics of the drainage in part of the area covered by the present study, while in giraudi (2015) some features of the drainage of the eastern monferrato were taken into account. the studies made it possible to recognize some stream captures or diversions but only some of the variations that occurred in the middle-late pleistocene have been chronologically framed (carraro et al., 1980; giraudi, 1981; carraro & valpreda, 1991; carraro et al., 1995; dela pierre et al., 2003b; giraudi, 2015; 2016). 5.1. drainage network features most of the main streams in the monferrato, north of the divide between the po and the tanaro, show a common trend (fig. 5a): at the head of the valleys the streams flow nw-se and nnw-ese, then they turn toward ne or nne. in the case of the ponara stream, a tributary of the rotaldo, at the head of the valley it flows from nne to ssw, and then takes the same direction as the other streams. a more detailed observation of the drainage network in the monferrato hills and the buried monferrato allows some areas with different features (fig. 5b) to be identified. area 1: the heads of the main valleys are parallel to the divide between the po and tanaro catchments and their southern slopes correspond to the divide. in general, the prevailing direction of the streams is towards south-east and east. the tributary basins of the main valleys are mainly elongated in the directions from nw to se and from n to s. the valleys of the main streams (stura, colobrio, grana, rotaldo) trending from nw and wnw to se and ese at the head, turn n and ne at the boundary of the area. their basins are clearly asymmetric and the tributary basins facing the northern quadrants are much narrower than those facing the southern ones (fig. 5a). the asymmetry of the slopes is very clear near the places where the change in direction of the streams occurs, that is in correspondence with elbows of capture of the upper stura and colobrio valleys reported in previous papers (biancotti & franceschetti, 1979; dela pierre et al.,2003b). the capture of the upper stura valley, which originally drained towards the sw, was assumed by said authors after the evaluation of morphological parameters, while that of the colobrio is represented on a map without any discussion. the capture of the valleys and the abrupt changes in direction occur in correspondence with faults trending mainly sw-ne, as reported in dela pierre et al (2003b). abrupt changes of direction occur also in the high grana and rotaldo valleys, in correspondence with sw-ne trending faults and of strong asymmetries of the valleys. the change of direction of the valleys, from nw-se to sw-ne, takes place in an area formed by pliocene sediments in the alessandria basin. those sediments reach elevations higher then the hills forming the divide between the po and tanaro rivers but lower than that of the hills lying to the north 26 giraudi c. heads of all the basins begin at the divide between the northern and southern slopes of the hills, and the streams flow in directions transverse to the divide. area 2: this includes part of the stura, rotaldo and grana catchments (fig. 5b) where the main streams flow, in general, from sw to ne. the stura stream direction of flow is more complex: it first flows from sw to ne, then w e, and finally forms an elbow and starts heading nne. the main and secondary streams flow in many different directions (fig. 5a;b). the tributaries of the stura stream drain both sesse and ne-nne, i.e. towards the axis of the lower stura valley (cerrina valley). in this area, while the slopes of the main valley are quite symmetrical (fig. 6a), the slopes of the small valleys of the secondary streams can be asymmetrical. the small valleys often have slopes facing west much more extensive than those facing east or vice versa. in area 2, also the (fig, 3). other sharp variations in the direction of the stura and grana valleys (fig. 5a) are present in correspondence with stretches of valley having characteristics very similar to the elbows of capture evidenced in literature area (1): it is located south of the po-tanaro divide (fig. 5b) and corresponds to the catchment of the versa stream, mostly developed on pliocene marine sediments, draining towards south or south-east, and was studied by carraro & valpreda (1991). in area (1) the drainage is more complex than in the other catchments draining south (fig. 4a, 5a): the versa stream flows from nw to se, running parallel to the divide, then turns eastwards, then southwards, and then, once again, flows from nw to se. the heads of some smaller catchments in this area do not reach the divide between the po and the tanaro. all the other basins lying south of the divide have a drainage system similar to that of the a zone (fig. 4a): in fact the 27 the pliocene and early pleistocene drainage network evolution in the monferrato hills ... fig. 4 a: morphological outline of the monferrato and torino hills and the buried monferrato drainage network, showing areas with different drainage patterns. b: geological outline of the main tectonic structures and sediments forming the monferrato and torino hills and the buried monferrato. rotaldo and grana streams flow from sw to ne (fig. 5a). on the left side of the lower catchment of the rotaldo stream, the direction of the tributary streams is from wnw to ese. the tributaries of the ponara stream flow mainly from wnw to ese but some flow from wsw to ene. in the south-eastern portion of 28 giraudi c. fig. 5 drainage network and areas with a different drainage pattern in the monferrato hills and the buried monferrato. a: drainage network and catchment basins. b: areas with different drainage patterns. area 2, the secondary streams flow mainly nw-se and se-nw into the rotaldo and grana streams. both the mouth of the rotaldo valley and the catchments of some secondary streams are very asymmetric (fig. 6a), with slopes facing the western quadrants much less extensive than those facing east. in a few cases the slopes facing the southern quadrants are much narrower than those facing north. a divide separates the major catchments forming area 2: the basin of the stura (to the west) and the portion of the rotaldo basin west of the stream (to the east). however, until the middle pleistocene, the stura basin and a portion of the rotaldo basin were part of a single catchment crossed by a river from its north-western edge to the south-eastern one (enel, 1984; carraro et al., 1995; dela pierre et al., 2003b; giraudi, 2015; 2016). area 3: here the stura flows from ssw to nne, but the main streams of this area run approximately w-e and e-w and their tributaries flow from nw, n, s, sw, and se (fig. 5b). fig. 6a shows that the valley slopes are usually asymmetrical and that generally the sides facing north are narrower than those facing south. in only two cases are the slopes facing east much more extensive than those facing west (fig. 6a). in the final stretch of the cerrina valley, where the stura runs ssw-nne, this kind of asymmetry is in correspondence with a northward elbow of capture of a river, mentioned above, which until the middle pleistocene drained se towards the rotaldo valley, as evidenced before. area 4: here the streams drain mainly towards n, nne and ne and flow directly into the river po. only in the eastern area are there any asymmetries in the valleys (fig. 6a), with slopes facing the eastern quadrants far larger than the opposite ones. also in this area, in two cases out of three, the asymmetry is in correspondence with the elbow of capture of a stream flowing towards nne but draining originally towards ese (carraro et al., 1995; dela pierre et al., 2003b; giraudi, 2015; 2016). area 5: the streams here flow into small valleys in a nne direction, but when they reach the plain, they do not flow directly into the river po, but into a series of secondary streams, tributaries of the river. in this area there are asymmetries in the basins (fig. 6a): the slopes facing south are far less extensive than the opposite ones. area 6: isolated hills with radial drainage that cannot be represented at the scale of the figures. 6. discussion the hypotheses of captures and changes in the drainage network reported in previous papers were based in one case (cerrina valley) on the lithological composition of the alluvial sediments, and in the other cases (stura and colobrio valleys) on morphological features, mainly the presence of elbows of capture. the presence of a different drainage in the lower cerrina valley is indicated by the presence of a significant amount of early and middle pleistocene alluvial sediments (fig. 2), formed by clasts of alpine origin. these sediments demonstrate the presence of a river flowing from the area sited nw of the valley head (giraudi, 1981; carraro et al., 1995; giraudi et al., 2003; dela pierre et al., 2003a,b; giraudi, 2016). the river continued se of the cerrina valley (fig. 6a) reaching the eastern monferrato hills and probably the buried monferrato north of the hills, as suggested by the lithology of some patches of alluvial sediment found in terraces and in boreholes (enel, 1984; carraro et al.,1995; giraudi, 2015; 2016). the old drainage network, mainly elongated in a nw-se direction, and running in drainage area 2, was strongly modified around 600 ka ago. the capture of the upper stura and colobrio valleys which, according to biancotti and franceschetti (1976) and dela pierre et al (2003b), in origin drained towards sw, was assumed from the presence of an elbow of capture. before capture, the divide between the catchments flowing towards the savigliano-alessandia and po basins was near the northern divide of the upper stura and colobrio valleys (fig. 6a). the presence of pliocene sediments in a small portion of the catchment testifies that part of the head of the present colobrio valley was covered by the pliocene sea in the alessandria basin. after emersion, as a consequence of the zanclean regression, the colobrio excavated its bed in the newly emerged marine sediments in a se direction. later, the stream was captured towards the ne. in the same figure, it can be observed that in correspondence with the elbows of capture of the cerrina, stura and colobrio valleys there is pronounced asymmetry of the slopes and therefore also the asymmetry could be linked to the morphological evolution that contributed to or followed the captures. the captures and the abrupt change in direction occur in correspondence with faults (fig. 6a) trending mainly sw-ne reported in dela pierre et al (2003b). abrupt changes of direction occur also in the high grana and rotaldo valleys, in correspondence with swne trending faults and of strong asymmetries of the valleys (fig. 6a; b). having the same geological and morphological characteristics as the stura and colobrio valley elbows of capture, it can be assumed therefore that also the rotaldo and grana valley elbows were due to captures (fig. 6a; b). the elbows of capture of the grana and rotaldo valleys occur in an area formed also by pliocene sediments of the alessandria basin that reach elevations higher than the hills forming the divide between the po and tanaro rivers but lower than that of the hills lying just north (fig. 3). it follows that, before the capture and until a period following the post-zanclean regression, the rotaldo and grana streams flowed towards the alessandria basin and the divide was roughly in correspondence with the hills forming the northern divide of the head of the rotaldo valley. it can be observed also that the stura, colobrio, grana and rotaldo streams show the same trend, both in areas 1 and 2, and therefore a common evolution can be assumed. the former divide between the basins draining 29 the pliocene and early pleistocene drainage network evolution in the monferrato hills ... 30 giraudi c. fig. 6 asymmetry of the valleys and elbows of capture (6a) and relations between the drainage network and major tectonic features (6b). towards the alessandria and the po basins was near the boundary between areas 1 and 2. other sharp variations in the direction of the stura and grana valleys (fig. 6a) are present in correspondence with stretches of valley having characteristics very similar to the elbows of capture evidenced in literature and discussed before. it is likely that said elbows were produced by other captures. 6.1. structural and lithological forcing in the drainage network in fig. 4b, it can be observed that both in the monferrato and torino hills the boundaries between zones a, b, c and a1 correspond to or are located in the vicinity of some deformation zones: the rio freddo deformation zone between a and b, the giarole-lu deformation zone between b and c, and the valenza deformation zone between c and a1. tectonics probably played a role in determining the drainage evolution in the monferrato hills as observed by previous authors (biancotti & franceschetti, 1979; carraro et al., 1980; giraudi, 1981; carraro & valpreda, 1991; carraro et al., 1995; dela pierre et al., 2003b; forno & lucchesi, 2005; vezzoli et al., 2010; giraudi, 2015; forno & lucchesi, 2016). the comparison between the morphology of the valleys, the position of the elbows of capture and the tectonic structures (fig. 6b) suggests the following considerations: the widest valleys correspond to synclines active also during the late miocene and sometimes during the pleistocene; the highest ridges are located in the western hills and in general coincide with the presence of coarse cemented sediments involved in complex uplifted structures active before the pliocene; changes in direction of the valleys and elbows of capture towards the north mostly occur in correspondence with faults trending sw-ne and deformation zones (fpdz; sldz; gldz; vdz) trending sw-ne, wsw-ene, and n-s, active also during and after the pliocene. the tectonic structures and the lithology also affect the boundaries between the areas in which the drainage network shows different characteristics: the boundary between areas 1 and 2 mostly coincides with ridges formed by strongly cemented sediments present in complex uplifted structures; the boundary between areas 2 and 3 corresponds to the transition between hills with pre-pliocene tectonic structures trending from nw to se and hills where we trending structures prevail; the boundary between areas 2 and 4 lies in the southern extension of the fontanetto po deformation zone active also during the pleistocene; part of the boundary between areas 2 and 3 lies in the southern extension of the trino and salera line deformation zones, active also during the pleistocene; the boundary between areas 2 and 5 coincides with the giarole-lu deformation zone active until the pleistocene; the boundary between areas 5 and 4 is in correspondence with the valenza deformation zone active also during the pleistocene. comparing between the maximum heights of the hills and the elevation reached by the zanclean sediments of littoral facies, next to the divide between the po and the tanaro basins (fig. 3), the difference that can be seen is of about 100 m in both the western monferrato (400-440 m and 330 m respectively) and the eastern monferrato (250-260 m and 160 m). it may be concluded that most of the differences in the maximum heights of the hills were due to a differential uplift that occurred after the zanclean, and that the western portion of the study area underwent a greater uplift, estimated at about 150-170 m. the structural and lithological influence on the drainage network seems therefore real. however in the core of the monferrato hills, the directions of the streams, not affected by sw-ne trending faults, follow the trend of the main tectonic structures active before the pliocene. it can be hypothesized that, when the core of the monferrato emerged from the sea, the initial nwse and wnw-ese orientation of the streams was conditioned by the different strike, dip and erodibility of the already deformed pre-pliocene sediments, and therefore the influence of the older tectonic structures was mostly passive. the flow towards se or ese of the streams was also affected by the stronger post-zanclean uplift of the western monferrato hills. 7. the pliocene drainage network and its evolution the pre-zanclean emersion of the monferrato core formed mainly by tertiary marine sediments, already strongly deformed, and the clear structural forcing on the drainage network, allow speculation about the original drainage. fig. 7a shows the possible drainage network on the just emerged lands, before the capture to the north of the main streams. the drainage must have been conditioned by the pre-pliocene tectonic structures and by lithology, with the valley bottoms in correspondence with synclines or formations consisting of softer sediments easy to erode, and the top of the ridges and the main divides lying on strongly cemented sediments forming the uplifted structures. the boundary between areas 1 and 2, lying near the elbows of capture of the main streams and in correspondence with the highest hills formed by strongly cemented uplifted sediments, was probably the divide between the zanclean catchment basins draining towards the saluzzo-alessandria and the po marine basins. this hypothesis is corroborated by the presence of zanclean sediments of the southern basin north of the present-day po-tanaro divide. it can be observed that the head of the grana valley, cut into zanclean marine sediments (fig. 2), was still below the sea during the early pliocene and emerged only during the post-zanclean regression (fig. 7a). during the regression, the colobrio, grana and 31 the pliocene and early pleistocene drainage network evolution in the monferrato hills ... fig. 7 the pliocene and gelasian drainage evolution (a) and uplifted and subsiding areas (b). rotaldo streams, already existing during the pliocene, excavated their beds in the newly emerged marine sediments. south of the hills the streams drained mainly nnw -sse, that is towards the saluzzo-alessandria basin while east of the hills they drained to the east and ne into the po basin. the capture of the high colobrio, grana and rotaldo valleys was probably due to the withdrawal of the heads of streams draining towards the northern basin, in correspondence with faults cutting through the uplifted structures forming the earlier divide. the headward erosion of the stream flowing to the north and the capture of streams flowing towards the south can be explained considering the known geological evolution of the monferrato. the flow of the streams towards the southern basin may have been hindered by the uplift of the neo 32 giraudi c. monferrato with respect to the northern hillslope. this interpretation is supported by the comparison between the elevation of the pliocene sediments of the southern and northern basins (fig. 3). according to the geological map of italy at the scale 1: 100,000, sheets 57, 58, 69, 70 (anfossi et al., 1969; boni & casnedi, 1969; bonsignore et al., 1969; braga & ragni, 1969; corsi et al., 1969; montrasio et al., 1969), the pliocene sediments of the southern basin reach elevations between 290 and 250 m a.s.l. between the colobrio and grana valleys, while those of the northern basin lie between 205 and 150 m a.s.l. in the same period, the headward erosion of the streams flowing northwards was increased by the lowering of the base level due to the subsidence of the northern basin which, until the gelasian, was still covered by the sea (enel, 1977; 1984; pieri & groppi, 1981; cassano et al., 1986; violanti & sassone, 2008; giraudi, 2014; 2016). the subsidence lasted at least until the middle pleistocene (giraudi, 2015; 2016). the uplift of the neo-monferrato and the subsidence of the northern basin could have favoured also the headward erosion of the streams and the capture of the high stura valley. however, also the subsidence of the cerrina valley, which acted as a local base level of the stura and colobrio streams, could have played an important role. the subsidence of the cerrina valley (giraudi, 2016) started before the sub-chron olduvai (age 1.9-1.7 ma). during the olduvai, the sedimentation started as lacustrine silty clay, followed, during the jaramillo subchron and the early matujama chron, by the sedimentation of alluvial deposits consisting mainly of clasts of alpine origin. it can be ruled out that the headward erosion and lake sedimentation were coeval. in fact it is supposed that during the phases of headward erosion the streams had to carry downstream many clasts consisting of marine sediments outcropping in their catchments. but the lacustrine sediments have an extremely fine grain size and no coarse alluvial sediments of local origin, interfingered with lacustrine sediments, have been observed. the alluvial deposits (dated from about 1 to 0.7 ma), contain few clasts of local origin, and it is unlikely that they were contemporary with the phases of headward erosion of the streams. a younger age of the captures is ruled out by the stratigraphy, lithology and grain size of the later alluvial sediments and by the morphological features. we can assume, therefore, that the erosion phase, to which the capture of the heads of the stura and colobrio valleys was connected, was mostly completed during the gelasian, before the olduvai sub-chron. to sum up, the headward erosion that led to the capture of the valleys draining towards the southern basin during the zanclean and the following regression started with the piacenzian uplift of the neo-monferrato and ended, probably, before the olduvai sub-chron. although some important captures and diversions occurred later, during the middle and late pleistocene (giraudi, 1983; carraro et al., 1995; dela pierre et al., 2003; giraudi, 2015; 2016), the middle pliocene-early pleistocene captures shaped the most evident anomalies in the monferrato drainage network. 8. conclusions during the pliocene, a portion of the monferrato emerged as an island on which a drainage network developed. analysis of the morphological and stratigraphic data has made it possible to reach a comprehensive interpretation of the drainage evolution in the monferrato from the pliocene to the early pleistocene. the heads of the basins of the stura, colobrio, rotaldo and grana streams drained southwards, towards the savigliano and alessandria synclines. the flow towards the south of those streams, that followed the post-zanclean regression, was hindered by the piacenzian uplift of the neo-monferrato, south of the core of the hills. the headward erosion of the streams draining towards the po basin, that produced the capture of the heads of said streams, possibly started during the zanclean regression and was strengthened by the subsidence of the northern basin, occupied by the sea until the gelasian. the headward erosion was favoured also by the presence of tectonic structures (faults and deformation zones) cutting into the pliocene divide. according to the stratigraphic data, it can be assumed that the capture of the high valleys of the stura, colobrio, rotaldo and grana streams occurred between the piacenzian and before the early pleistocene olduvai chron. the correlation between the development of the hydrographic network and tectonic structures, assumed by previous authors, is confirmed and even strengthened by the relations between the drainage and the tectonic structures recognized in more recent investigations. tectonic structures played different roles. the gentle post-zanclean anticlines that form the neomonferrato, the pleistocene subsidence of the northern basin and the deformation zones transverse to the monferrato front, played a dynamic role in the evolution of the drainage network. conversely, the complex uplifted structures that form the core of the monferrato hills, active mainly before the pliocene, influenced, generally passively, the drainage network when the monferrato emerged from the sea, the initial direction of the streams being conditioned by the different strike, dip and erodibility of the pre-pliocene sediments. references anfossi g., bruno g.m., casnedi r., mosna s., motta e., perotto g., zezza f. (1969) foglio 70, alessandria, della carta geologica d’italia alla scala 1:100,000. ii ed., servizio geologico d’italia, roma. arpa piemonte (2014) banca dati geotecnica. available at: http://webgis.arpa.piemonte.it/flxview/ geoviewerrisknat/index.aspx biancotti a., franceschetti b. (1979) analisi dell’ambiente fisico del bacino del torrente stura del monferrato. in: studi dell’ires sui piani di si 33 the pliocene and early pleistocene drainage network evolution in the monferrato hills ... stemazione idrogeologica. parte prima: la stura del monferrato. editrice nova, torino: 51-101. bigi g., cosentino d., parotto m., sartori r., scandone p. (1990) structural model of italy, consiglio nazionale delle ricerche (cnr), progetto finalizzato geodinamica, quaderni de "la ricerca scientifica", 114 (3), 1:500.000 scale, firenze, selca. boni a., casnedi r. (1969) note illustrative della carta geologica d’italia alla scala 1:100.000, fogli 69 e 70, asti-alessandria. servizio geologico d’italia, roma. bonsignore g., bortolami g.c., elter g., montrasio a., petrucci f., ragni u., sacchi r., sturani c., zanella e. (1969) note illustrative della carta geologica d’italia, fogli 56 e 57 (torino e vercelli). servizio geologico d’italia, roma. bortolami g., crema g.c., malaroda r., petrucci f., sacchi r., sturani c., tagliavini s., venzo s. (1969) f. 56 “torino” della carta geologica d’italia alla scala 1:100.000. seconda edizione. servizio geologico d’italia, roma. bove forgiot l., trenkwalder s., violanti d. (2005) le associazioni plioceniche a foraminiferi ed ostracodi di verrua savoia (piemonte, italia nw): analisi biostratigrafia e paleo ambientale. rendiconti della società paleontologica italiana, 2, 9-27. braga g.p., ragni u. (1969) note illustrative della carta geologica d’italia alla scala 1:100.000 fogli 44 e 58, novara e mortara. servizio geologico d’italia, 56 pp. carraro f. (1996) revisione del villafranchiano nell’area-tipo di villafranca d’asti. il quaternario, 9 (1), 5-120. carraro f., forno m.g., ricci b. (1980) ricostruzione preliminare dell’evoluzione plio-pleistocenica dell’area corrispondente ai rilievi delle langhe, del monferrato e della collina di torino. contributi alla realizzazione della carta neotettonica d’italia. cnr progetto finalizzato geodinamicasottoprogetto “neotettonica”. pubblicazione n. 356, 315 -330. carraro f., valpreda e. (1991) the middle-upper quaternary of the asti basin. il quaternario, 4: 151172, roma. carraro f., collo g., forno m.g., giardino m., maraga f., perotto a., tropeano d. (1995) l’evoluzione del reticolato idrografico del piemonte centrale in relazione alla mobilità quaternaria in: polino r. & sacchi r. (eds.), atti del convegno: rapporti alpiappennino. acc. naz. sci. sc. doc, 14, 445-461. carraro f. (2012) geologia del quaternario. l’evoluzione geologica degli ambienti superficiali. 393 pp. d. flaccovio editore, palermo, italy. casnedi r. (1975) segnalazione di una successione stratigrafica compresa tra il langhiano e il pliocene inferiore a nw di valenza (monferrato orientale). rendiconti scientifici istituto lombardo, a 109, 178-184. corsi m., gatto g.o., gatto p. (1969) foglio 58, mortara, della carta geologica d’italia alla scala 1:100,000. ii ed., servizio geologico d’italia, roma. cassano e., anelli l., fichera r., cappelli v. (1986) pianura padana: interpretazione integrata di dati geofisici e geologici. 73° congresso della società geologica italiana. 1-27. costa m. (2003) the buried apenninic arcs of the po plain and northern adriatic sea (italy): a new model. boll. soc. geol. it., 122, 3-23. dela pierre f., michailov v., polino r. (1995) the tectonosedimentary evolution of the tertiary basins in the western po plain: kinematics inferred from subsidence curves. in: polino r. & sacchi r. (eds.), atti del convegno: rapporti alpiappennino. acc. naz.sci.sc.doc, 14, 129-146. dela pierre f., piana f., boano p., fioraso g., forno m.g., polino r. clari p. (2003a) carta geologica d'italia alla scala 1:50.000, foglio 157 "trino", apat, agenzia per la protezione dell'ambiente e per i servizi tecnici dipartimento difesa del suolo, roma. dela pierre f., piana f., fioraso g., boano p., bicchi e., forno m.g., violanti d., balestro g., clari p., d’atri a., de luca d., morelli m., ruffini r. (2003b) note illustrative della carta geologica d’italia alla scala 1:50,000, foglio 157 trino. apat, agenzia per la protezione dell’ambiente e per i servizi tecnicidipartimento difesa del suolo, roma, 147 pp. devoti r., esposito a., pietrantonio g., pisani a.r., riguzzi f. (2011) -evidence of large scale deformation patterns from gps data in the italian subduction boundary. earth and planetary science letters, 311, 230-241. enel (1984a) rapporto per la localizzazione di una centrale elettronucleare nella regione piemonte. area po 1. enel direzione delle costruzioni, roma. xix volumes, unpublished. enel (1984b) rapporto per la localizzazione di una centrale elettronucleare nella regione piemonte. area po 2. enel direzione delle costruzioni, roma. xix volumes, unpublished. festa a., boano p., irace a., lucchesi s., forno m.g., dela pierre f., fioraso g., piana f. (2009b) note illustrative della carta geologica d’italia alla scala 1:50,000, foglio 156 torino est. apat, agenzia per la protezione dell’ambiente e per i servizi tecnicidipartimento difesa del suolo, roma, 143 pp. forno m.g., lucchesi s. (2005) la successione fluviale terrazzata pleistocenica dei versanti occidentale e nordoccidentale della collina di torino. il quaternario, 18 (2), 123-134. forno m.g., lucchesi s. (2016) relicts of the pleistocene po plain on the western and southern slope of turin hill (nw italy). journal of maps, 12 (2), 394-306. galadini f., falcucci e., galli p., giaccio b., gori s., messina p., moro m., saroli m., scardia g., sposato a. (2012) time intervals to assess active and capable faults for engineering practices in italy. engineering geology, 139-140, 50-65. gattiglio m., forno m.g., comina c., doglione a., violanti d., barbero d. (2015) the involving of the plio-pleistocene succession in the t. traver 34 giraudi c. sola deformation zone (nw italy). alpine and mediterranean quaternary, 18(1). gibbard p. l., head m. j., walker m. j. c. and the subcommission on quaternary stratigraphy (2010) formal ratification of the quaternary system/ period and the pleistocene series/epoch with a base at 2.58 ma. journal of quaternary science, 25, 96-102. giraudi c. (1981) presenza di depositi mediopleistocenici intensamente deformati in val cerrina (monferrato settentrionale). geogr. fis. din. quat., 4, 69-74. giraudi c., mottura a., sala b., siori m.s., bormioli d. (2003) the castagnone site (cerrina valley, monferrato hills, nw italy): early pleistocene sedimentary record and biochronology. rivista italiana di paleontologia e stratigrafia,109 (3), 517-526. giraudi c. (2014) quaternary studies as a tool to validate seismic hazard potential of tectonic structures: the case of the monferrato thrust front (vercelli plain, nw italy). alpine and mediterranean quaternary, 27(1),5-28. giraudi c. (2015a) quaternary evolution of the plain between casale monferrato and valenza: implications for the tectonics of the monferrato thrust front (piedmont, nw italy). alpine and mediterranean quaternary, 28 (1), 71-92. giraudi c. (2016) the evolution of the northernmost apennine front (piedmont, italy): plio-pleistocene sedimentation and deformation in the po basin and monferrato hills. alpine and mediterranean quaternary, 29(1), 45-65. gsqpgruppo di studio del quaternario padano (1976). studio interdisciplinare del "rilievo isolato" di trino (bassa pianura vercellese, piemonte), quaderno n.3, litografia massaza e sinchetto, torino. irace a., clemente p., natalicchio m., ossella l., trenkwalder s., de luca d.a., mosca p., piana f., polino r., violanti d. (2009) geologia e idrostratigrafia profonda della pianura padana occidentale. 110 pp, 61 allegati. la nuova lito, firenze. livio f., ferrario m.f., frigerio c., michetti a.m. zerboni a., bonadeo l., fioraso g., irace a., brunamonte f. (2015) late pleistocene reverse surface faulting at the pecetto di valenza site (alnorthern italy): preliminary results. conference of the gngts, sessione 1.1, 45-50. martinis b. (1954) ricerche stratigrafiche e paleontologiche sul pliocene piemontese. rivista italiana di paleontologia e stratigrafia, 60, 45-114 and 125194. michetti a. m., giardina f., livio f., mueller k., serva l., sileo g., vittori e., devoti r., riguzzi f., carcano c., rogledi s., bonadeo l., brunamonte f., fioraso g. (2012) active compressional tectonics, quaternary capable faults, and the seismic landscape of the po plain (northern italy). annals of geophysics, 55, 5, 969-1001. montrasio a., ragni u., bonsignore g., borgo a., zanella e., crema g., medioli f., petrucci f. (1969) foglio 57, vercelli, della carta geologica d’italia alla scala 1:100,000. ii ed., servizio geologico d’italia, roma. mosca p., polino r., rogledi s., rossi m. (2010) new data for the kinematic interpretation of the alpsapennines junction (northwestern italy. international journal of earth sciences, 99 (4), 833-849. piana f., polino r. (1994) la zona transpressiva di rio freddo e l’evoluzione convergente del monferrato e della collina di torino. atti ticinesi di scienze della terra, serie speciale, 1, 167-180. piana f., polino r. (1995) tertiary structural relationships between alps and apennines the critical torino hill and monferrato area, northwestern italy. terra nova, 7 (2), 138-143. pieri m., groppi g. (1981) subsurface geological structure of the po plain, italy. quad. cnr. prog. fin. geodinamica, roma, 1-13. sacco f. (1889) il bacino terziario e quaternario del piemonte. atti società italiana di scienze naturali, 31-32, 135-281, 289-398, 331-390. siori m.s., sala b. (2007) the mammal fauna from the late early biharian sito of castagnone (northern monferrato, piedmont, nw italy). geobios, 40, 207 -217. trenkwalder s., violanti d. (2001) il pliocene di verrua savoia (piemonte, italia settentrionale):sintesi dei nuovi dati biostratigrafici e paleoambientali. giornale di geologia, 62 supplemento, 77-82. vezzoli g., forno m.g., ando s., et al. (2010) tracing the drainage change in the po basin from provenance of quaternary sediments (collina di torino, italy). quaternary international, 222 (1-2), 64-71. violanti d., sassone p. (2008) il pliocene del sottosuolo di casale monferrato (piemonte, italia nordoccidentale): dati preliminari. atti museo civico di storia naturale trieste, 53 (supplemento), 233264. zappi l. (1961) il pliocene di castel verrua. atti società italiana di scienze naturali, museo civico di storia naturale milano, 100, 73-204. 35 ms. received: november 22, 2017 final text received: july 25, 2018 the pliocene and early pleistocene drainage network evolution in the monferrato hills ... 36 amq abs furlanetto et al palcom 131-134.pub available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 131 134 alnus viridis a sensitive snowfall indicator for past oceanic timberlines in the alps giulia furlanetto 1,2, cesare ravazzi 2, michele brunetti 3, lorena garozzo 2 1 bicocca, dept. of environmental and earth sciences, university of milano, milano, italy 2 idpa cnr, res. group on vegetation, climate and human stratigraphy, laboratory of palynology and palaeoecology, milano, italy 3 isac cnr, bologna, italy corresponding author: g. furlanetto <g.furlanetto1@campus.unimib.it> abstract: we analyse the modern ecological response of mountain alder (alnus viridis) pollen proportions (%) to climatic parameters along altitudinal gradients in two contrasting climate regions of the european alps and calculate pollen accumulation rates (par) to detect the effect of snowmelt runoff. we also compare independent sediment proxies for alluvial events in a high-altitude site of the outer italian alps (armentarga peat bog, 2345 m a.s.l.), which was selected to investigate alnus viridis response in the last 11000 years. keywords: european alps, holocene, alnus viridis, pollen accumulation rate, ehof models, palaeoclimate 1. introduction reconstructing the climate history of the high altitude alps in the present interglacial relies on a large number of natural archives and proxies. the sedimentary record of glacier activity, the most sensitive proxy of climate change, is well stocked but highly discontinuous, thereby making it difficult to decouple temperature and snowfall contributions triggering glacial advances. hopefully, plant and sediment deposition in high altitude areas, either from speleothems, lakes or peat bogs, provides continuous isotopic and biological records. however, in speleothem isotopic records (fohlmeister et al., 2012) a precipitation signal is difficult to discriminate, while most high altitude biological proxies respond primarily to summer temperature modulations (e.g. chironomids and cembran pine (pinus cembra) timberlines). up to present, available validated precipitation records derive from dendroclimatic series only (büntgen et al., 2011). here we propose to analyse the timberline record of alnus viridis (mountain alder) in the oceanic climate regions of the alps to reconstruct holocene oscillations in precipitation, mostly referred to snowfall. mountain alder is a deciduous shrub needing continuous water supply during the growing season, enhanced either by climatic high annual snowfall rate or by edaphic wetness (richard, 1968,1969; mauri & caudullo, 2016). extensive mountain alder shrublands develop in the subalpine altitudinal belt under oceanic, cool temperate climates that hinder cembran pine fitness. edaphic geodiversity allows mountain alder to compete with dwarf pine (pinus mugo), the latter also tolerating oceanic climates, but escaping edaphic wetness. apart from snowfall, timberline forests formed by these alpine dwarf shrubs are controlled by historical biogeography (range dynamics of refugial populations since the last glaciation) and human impact (human fire set to clear forests for pastoralism and mining). given these ecological constraints, we analyse the modern ecological response of mountain alder pollen proportions (%) to climatic parameters along altitudinal gradients in two contrasting climate regions of the alps, and we calculate pollen accumulation rates (par) to detect absolute pollen changes, which may reflect either population fluctuations or snowmelt runoff. we also compare independent sediment proxies for alluvial events in a high-altitude site of the outer italian alps (armentarga peat bog, 2345 m a.s.l., fig. 1), which was selected to investigate alnus viridis response in the last 11,000 years. fig. 1 map of july climatogy (1961-1990) with 170 empd sites (white dots), la thuile valley training set (black dots), upper brembana valley training set (blue dots) and armentarga fossil site (a) plotted. on the right map of annual precipitation (1961-1990) and the location of the two altitudinal training sets. https://doi.org/10.26382/aiqua.2018.aiquaconference 2. material and methods a modern pollen-climate calibration dataset for alnus viridis was created selecting one hundred and seventy alpine sites from the empd-european modern pollen database (davis et al., 2013) in which alnus viridis was kept distinguished and adding fifty-three plots from the two new altitudinal training sets, respectively in an oceanic, outer district of the chain in the central alps (upper brembana valley training set; furlanetto et al., unpublished data) and in a continental inner valley of the western alps (la thuile training set; badino et al., 2018; furlanetto et al., unpublished data) (fig. 1). sitespecific temperature and precipitation series, covering the 1951-2010 period, were reconstructed for each sampling site, by means of the anomaly method as described in brunetti et al. (2012). from these monthly series, mean temperature of the warmest month (tjuly) and the total annual precipitation (pann) were calculated. alnus viridis individual response (fig. 2) was obtained using the extended huisman-olff-fresco fitting method using r 3.2.3 version and ehof package (jansen & oksanen, 2017). sixty-two fossil samples from a lake peat bog record in an outer oceanic district of central alps (armentarga record, fig. 1) were processed following standard methods at the laboratory of palynology and palaeoecology of cnr-idpa in milano, and identified at the optical microscope, reaching a minimum pollen sum of six hundred pollen grains x sample. eight 14c dates were obtained on upland plants remains samples from the study deposits. radiocarbon ages were calibrated and deposition rates were modelled (fig. 3). the calculation of par values for a specific taxon in a sample is not dependent on other taxa occurring in the same sample (birks & birks, 1980). alnus viridis, one of the main timberline ecotone shrub species in the outer oceanic districts of central alps, shows a specific altitudinal par arrangement under modern climate conditions (tab. 1). these par measurements have been used as a modern reference to estimate past plant population densities. pollen-climate transfer functions were derived from weighted averaging partial least squares (wa-pls) regressions (ter braak & juggings, 1993) using a calibration set of two hundred thirty-three modern pollen samples; a 2-component wa-pls model was selected. 132 fig. 2 diagrams showing the simplest statistically significant response model for alnus viridis from the 233 sites and the two single training sets (la thuile valley and upper brembana valley) in relation to a) annual precipitation and b) july temperature as assessed by a hierarchical set of taxon response models within the framework of generalized linear modelling. furlanetto g. et al. 133 3. results in the calibration dataset of two hundred thirty-three modern pollen samples ehof fitting shows that alnus viridis has a significant relationship with annual precipitation being monotonic (optima of ca. 1800 mm at the gradient extreme) and with july temperature being skewed bimodal, with the main optima at ca. 12 °c (fig. 2a, d). in the la thuile valley training set alnus viridis has an estimated optimum of 10 °c and 1050 mm (fig. 2b, e), while in the upper brembana valley training set it has a double optimum with higher temperature and precipitation (respectively 11.5 and 15 °c, 1810 and 1870 mm) (fig. 2c, f). alnus viridis, the main timberline ecotone shrub species in the upper brembana valley, shows a specific altitudinal par arrangement under modern climate conditions (tab. 1). the highest par values in the upper brembana valley training set are observed in the plots l2 and l5 located at mountain altitude (respectively at 1420 and 1940 m a.s.l.) in river corridors and waterfalls with mountain alder scrub with par values of 2400 and 3100 pollen grains cm-2 yr-1 (tab. 1, tl2 and tl5). in the pollen traps at subalpine altitude (tab. 1, tl15, tl14; respectively 2100 and 2180 m a.s.l.), located at the border of mountain alder scrub with continuous understory of ericaceae, par values are about 700 pollen grains cm-2 yr-1. modern par data from armentarga peat bog show values that range from 100 to 400 pollen grains cm-2 yr-1 (tab. 1, tl10 and tl10 lt). these par measurements have been used as a modern reference to estimate past plant population densities (fig. 3). palaeoecological data from the armentarga peat bog (fig. 3) show a general increase of alnus viridis from ca. 7,000 years cal bp (alnus viridis % and par) and a concurrent increase of lithic fragments concentration and of silicoclastic + oxides contents with an opposed decrease of pinus sylvestris/mugo and pinus cembra type. starting from 1,300 years cal bp a sharp decrease of alnus viridis par values and increase of total p occur till 300 years cal bp. pollen-inferred annual precipitation show a sharp increase from 7,200 years cal bp with short phases of precipitation decrease during the early bronze age and roman period (fig. 3). 4. discussion and conclusion the observed alnus viridis response offset between the paired sites considered is related to variations in local climates (from oceanic external chains to continental inner districts). alnus viridis vegetation needs continuous water supply during the growing season, enhanced by high annual snowfall rate and good soil water balance. accordingly, in alpine oceanic climates, the ecological response of the species expands downstream especially along avalanche corridors but also on northern slopes, due to a general increase in soil moisture. this results in a displacement of its optima towards higher temperature and precipitation (fig. 2c, f, upper brembana valley training set), thus reducing the overall tjuly signal of alder pollen abundance in oceanic climates (fig. 2f). palaeoecological and sedimentary data from armentarga peat bog show an increase of snowmelt runoff from ca. 7,000 to 5,000 years cal bp (alnus viridis par values relative to respective %, lithic fragments concentration and silicoclastic + oxides contents) and decrease of temperature. this humid phase is confirmed by a sharp increase in pollen-inferred annual precipitation since 7200 years cal bp (fig. 3). alnus viridis par values show significant peaks from 6,000 to 1,300 years cal bp, comparable or above the modern absolute par values obtained in the mountain alder scrub (pollen traps tl 15 and tl14), thus arguing for phases of alder timberline rises. starting from 1300 years cal bp, the record of alnus viridis par values is negatively correlated to an increase of total phosphorus, suggesting that the long since wellestablished alder subalpine belt was affected by high human impact since the early middle ages. acknowledgements this extended abstract is a result of a phd research project sponsored by the milano-bicocca university, dept. of earth and environmental sciences, with the co-tutoring and support of the cnr-idpa. we are grateful to parco delle orobie bergamasche for the support to this research program. references badino f., ravazzi c., vallè f., pini r., aceti e., brunetti m., champvillair e., maggi v., maspero f., perego r., orombelli g. (2018) 8800 years of high-altitude vegetation and climate history at the rutor glacier forefield, italian alps. evidence of middle holocene timberline rise and glacier contraction. quaternary science reviews, 185, 41-68. alnus viridis a sensitive indicator for oceanic climate tab. 1 modern alnus viridis par values based on pollen monitoring data in the upper brembana valley, representing the period 2016-2017. the location of the upper brembana valley training set is shown in fig. 1. birks h.j.b., birks h.h. (1980) quaternary palaeoecology. arnold e, london, uk. brunetti m., lentini g., maugeri m., nanni t., simolo c., spinoni j. (2012) projecting north eastern italy temperature and precipitation secular records onto a high-resolution grid. physics and chemistry of the earth, 40-41, 9-22. büntgen u., tegel w., nicolussi k., mccormick m., frank d., trouet v., kaplan j.o, herzig f., heussner k.u, wanner h., luterbacher j., esper j. (2011) 2500 years of european climate variability and human susceptibility. science, 331, 578582. davis b.a.s., zanon m., collins m., mauri a., bakker j., barboni d., barthelmes a., beaudouin c., birks h.j.b., bjune a.e. et al. (2013) the european modern pollen database (empd) project. vegetation history and archaeobotany, 22(6), 521-530. fohlmeister j., vollweiler n., spötl c., mangini a. (2012) comnispa ii: update of a mid-european isotope climate record, 11 ka to present. the holocene, 23 (5), 749-754. jansen f., oksanen j. (2017) extended hof (huisman-olff-fresco) models. r package version 1,8. mauri a., caudullo g. (2016) alnus viridis in europe: distribution, habitat, usage and threats. in: sanmiguel-ayanz j., de rigo d., caudullo g., houston durrant t., mauri a. (eds) european atlas of forest tree species. publication office of the european union, luxembourg, p. 68. richard l. (1968) écologie de l'aune vert (alnus viridis): facteurs climatiques et édaphiques. documents pour la carte de végétation des alpes, 6, 107-158. richard l. (1969) une interprétation éco-physiologique de la répartition de l'aune vert (alnus viridis). documents pour la carte de végétation des alpes, 7, 7-23. ter braak c.j.f., juggings s. (1993) weighted averaging partial least squares regression (wapls): an improved method for reconstructing environmental variables from species assemblages. hydrobiologia, 269/270, 485-502. 134 furlanetto g. et al. fig. 3 fossil alnus viridis par data and pollen inferred annual precipitation from armentarga fossil record compared with other palaeoecological and geochemical data. ms. received: may 4, 2018 final text received: may 17, 2018 available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 93 97 palaeoenvironment and vegetation history in the central po plain (n-italy) between 33-30 ka cal bp under the impact of millennial climate change cesare ravazzi 1 , lorena garozzo 1 , massimiliano deaddis 1,2 , mattia de amicis 3 , mauro marchetti 4 , roberta pini 1 , giovanni vezzoli 3 , andrea zanchi 3 1 laboratory of palynology and palaeoecology, cnr idpa, milano, italy 2 cfp san giuseppe cooperativa sociale onlus, lodi, italy 3 dept. of environmental and earth sciences, university of milano bicocca, milano, italy 4 dept. of education and humanities, university of modena and reggio emilia, reggio emilia, italy corresponding author: c. ravazzi <cesare.ravazzi@idpa.cnr.it> abstract: the last glaciation environmental history of the po plain (northern italy) is still poorly known. here we present a multiproxy record from a compressed peat dated 33-30 ka cal bp, underlying the last glacial maximum fluvio-glacial belt in the adda river catchment. slow river dynamics and subsurface water saturation granted stable surfaces supporting mixed pine-birch forests, including open wetlands marshes and swamps and open drylands, with juniper bushes, connected to sandy river bars. fire phases favoured birch but decreased arboreal pollen, although open lands did not expand. we discuss relationships with millennial climate variability between gi-6 and gs-5.1. keywords: last glaciation, po plain, boreal forest, alluvial plain, radiocarbon dating, millennial climate variability 1. introduction the late pleistocene geological and environmental history of the central po plain in northern italy is driven by phases of aggradation by large alluvial bodies, mostly originating at the pre-alpine margin from the valley outlets of the two major alpine rivers (i.e. adda river, see fig. 1, and oglio river). actually, as far as the adda and oglio glaciers occupied their piedmont end moraine systems, about 27 to 21-18 ka cal bp, several outwash rivers were actively building up a coalescent sandar belt even reaching the axial sector of the po plain (ravazzi et al., 2012), palaeoenvironments being dramatically influenced by fast channel dynamics and persisting high water discharge. here we present a high-resolution palaeobotanical research and coupled alluvial stratigraphy carried out in the underlying deposits dated to late mis 3 and thus shortly preceding the last glacial maximum (lgm) peak aggradation events, depicting a comparatively different environmental framework for the distal adda plain, with forested stable surfaces, millennial-standing pools and low sedimentation rate, suggesting a low-gradient plain. thanks to a robust ams 14c chronology, we examine the effects of the pronounced millennial palaeoclimatic variability which affected northern italy in late mis 3. 2. material and methods a 18 m-thick sediment sequence outcropping at casaletto ceredano (coord. wgs84 45°18'49.75"n, 9°37'21.86"e; province of cremona, 65 m asl, fig. 1), along the scarp of the entrenched postglacial adda river valley, shows the depositional history between > 40 and the local end of the lgm aggradation surface. the complete sections are shown in fig. 2; the study focused on a 40 cm-thick compressed peat and silty peat, sampled through a 50 cm-long metal box. palynology (27 samples), macroscopic charcoal (48) and geochemistry (81) were analyzed. pollen and other microbiological particles were extracted by chemical treatments (acid treatments, koh), microfiltrations and acetolysis, and identified at the optical microscope, reaching a minimum pollen sum of 500 pollen grains. macrocharcoal fragments between 125 µm 1 mm and > 1 mm length were wet-sieved and counted under a stereomicroscope. four samples of wood and charcoal fragments were radiocarbon-dated at the angstrom lab., uppsala university. calibration was carried out using calib version 7.0.4 with the intcal13 calibration curve (reimer et al., 2013). an age-depth model was built up with the bayesian technique in oxcal package. 3. results 3.1. chronology the dated wood and charcoal originate from two sections exposing the compressed peat stratigraphy which could be visually correlated at cm-detail. the composite section yielded ages spanning a nice sequence (tab. 1) between 25975 ±450 and 32950 ±1070 14c a bp (median calibrated ages 30144 37150 cal a bp). we selected in situ wood and large wood charcoal fragments (unweathered compressed wood from tree stems and cm-thick wood charcoal) in order to minimize the effects of either contamination or rielaboration. the latter https://doi.org/10.26382/aiqua.2018.aiquaconference taphonomic process is a cause of age bias in drift peat imbedded in alluvial and glacial deposits. the availability of datable wood tissue from tree stems obviously depends on tree occurrence in contemporary vegetation, a circumstance which favourably compares with the forest persistence in n-italy throughout the last glaciation. a posterior analysis of a bayesian age/depth model designed in software oxcal also supports the reliability of the obtained age sequence between top and base of the compressed peat layer, spanning about three millennia between (29172 -2σ range) 30144 and 33427 (34791 -2σ range) cal a bp. 3.2. pollen, charcoal stratigraphy and vegetation history we obtained a pollen and charcoal record with an average sample resolution (133 and 65 years respectively) suitable to detect centennial-scale secondary ecological successions as well as the effects of millennial climate events which characterized the late mis 3, although our detail is still not appropriate to check fire frequency. the vegetation history is clustered in the following pollen % phases (fig. 3, upper panel): cc01 (91-93 cm) before the onset of organic deposition, sandy sediments are characterized by moderate values of pine pollen (pinus sylvestris/mugo) accompanied by several herbs. low xerophytes (artemisia, ephedra, hippophaë, chenopodiaceae) mark open environments, such as sandy riverbeds. cc02 (93-97 cm) an organic soil rich in charcoal particles developed, recording higher pine pollen percentages (75-88%). the abundance of charcoal, along with cm-size fragments, suggests local fires affecting pine woodlands. indicators of local wetlands are still scanty. cc03 (97-101 cm) a sharp decrease in pine pollen abundance is coupled with increasing values of betula (birch) and the expansion of wetland and herb vegetation (cyperaceae, gramineae). the in situ development of a carex (sedge) fen is shown by the abundance of sedge roots. we infer a withdrawal of pine forests that had previously been affected by fires, while pioneer birches and terrestrial wetlands expanded, favored by increasing water table. cc04 (101-111 cm) pine pollen increases again (values around 70%), juniperus and other xerophytes expand. we reconstruct a rather open pine forest, including sporadic spruce, with open land occupied by juniperus and herbs. a sedge marsh persists locally, its 94 fig. 1 digital terrain model of part of the central po plain in northern italy showing the valley cut by the adda river into the alluvial fan system formed during the last glacial maximum (in dark grey). tributary rivers brembo and serio, as well as inactive post-lgm valleys and ancient oxbow basins are shown. the casaletto ceredano sections are outcropping on the eastern scarp delimiting the post-lgm adda valley. lo = lodi; bg = bergamo; cr = crema. ravazzi c. et al. 95 fluctuations depending on detrital supply. cc05 (111-117 cm) pine stillstand (70%), xerophytes, open vegetation and sedge fen developed (sedges roots are abundant in sediments). the local environment was more drained and partially oxygenated, favoring the activity of some fungi (glomus). last phase (117-119 cm) pine pollen declines and birch expands, as a consequence of a renewed phase of fires. the find of tree birch stems in these peat layers suggests that those trees settled in situ together with sedges (birch swamp). 4. discussion and conclusion the compressed peat deposit at casaletto ceredano formed in a long-lasting wetland occupied by a terrestrial marsh and finally by a swamp forest, subtly fed by silt from the adda river catchment. the radiocarbon sequence robustly points to the persistence of this regime for about three millennia. this requires an overall subsurface water saturation, favoured by a thingrained texture (silty sands), and excludes fast river dynamics and aggradation processes in the area, which would have implied an immediate wetland burial by an actively growing minerogenic plain surface. accordingly, sediment accumulation rate for the underlying minerogenic deposits (0.16 mm/a between 37.1 and 33.4 cal ka bp) is low compared to estimated lgm fluvio-glacial rates. compressed peat layers are common in the lower adda valley alluvial record (casaletto ceredano unit, see ravazzi et al., 2012), but so far dated to > 40 cal ka bp, thus accumulation rates could not be measured yet. an impressive amount of late pleistocene mammal remains, including one neanderthal frontal bone, have been rielaborated, mostly from the casaletto ceredano unit and heteropic units formed in adjacent river catchments, and accumulated downstream in secondary deposition (persico et al., 2015). recent downcutting provides field evidence of post-depositional deformation in these peat seams, suggesting that late pleistocene deformational events may be of importance for the paludification history of the area, e.g. through the development of microrelief and channel diversions. palaeobotanical analysis established that pine and birch forests persisted across the late mis 3 on stable surfaces in the lower adda valley, regardless to intervening millennial climate variability. edaphic and topographic factors and ecological disturbance changes are believed to have modulated the extent of open habitats (open drylands on sandy river channels and bars, treefig. 2 summary logs of sections exposed along the eastern scarp of the adda river valley at casaletto ceredano. compressed peat layer in dark brown. p = root casts marking exposed surfaces in sand layers. labels 1 and 2 show the position of petrographic samples for sediment provenance analysis. tab. 1 radiocarbon ages obtained on terrestrial plant remains from the casaletto ceredano sections. palaeoenvironments of the central po plain 33 30 ka cal bp 96 ravazzi c. et al. less wetlands depending on subsurface water saturation, fire avoiding wetland areas). still, climate variability may have acted as the ultimate factor driving the alluvial geo-ecological system. in fig. 3 (lower panel) we compare isotope and dust proxies from the ngrip core depicting stadial-interstadial sequence between 30 and 34 cal ka bp (rasmussen et al., 2014) with the arboreal pollen and xerophyte pollen % from casaletto ceredano, plotted against their own age-depth model, and propose a tentative correlation. notice that, in our record, fire phases marks enhanced forest phases (gi-6 and gi-5.2). birch expansion occurred at the end of fire phases, mirroring the typical succession of modern boreal forests (sannikov and goldammer, 1996), and also lead to a slight arboreal pollen decrease, although open land did not expand henceforth. stadial phases gs-6 and gs-5.2 might correlate to phases of higher water table, triggered by increased fluvio-glacial discharge. overall, during late mis 3 the central po plain remained under a cold temperate regional climate of middle boreal type (moen, 1999), with tjuly < 15°c, but well within the climatic woodland limits. quantitative climate reconstructions are planned as next research step. references moen a. (1999) national atlas of norway vegetation. norwegian mapping authority, honefoss, n., persico d., billia e.m.e., ravara s., sala b. (2015) the skull of stephanorhinus kirchbergensis (jäger, 1839) (mammalia, rhinocerontidae) from spinadesco (cremona, lombardia, northern italy): morphological analyses and taxonomical remarks an opportunity for revising the three other skulls from the po valley. quaternary science reviews, 109, 28-37. rasmussen s.o., bigler m., blockley s.p., blunier t., buchardt s.l., clausen h.b., cvijanovic i., dahljensen d., johnsen s.j., fischer h. et al. (2014) a stratigraphic framework for abrupt climatic changes during the last glacial period based on three synchronized greenland ice-core records: refining and extending the intimate event stratigraphy. quaternary science reviews, 106, 14-28. ravazzi c., deaddis m., de amicis m., marchetti m., vezzoli g., zanchi a. (2012) the last 40 ka evolution of the central po plain between the adda and serio rivers. géomorphologie: relief, processus, environment, 2, 131-154. reimer p.j, bard e., bayliss a., beck j. w., blackwell p.g., bronk ramsey c., buck c.e., cheng h., lawrence edwards r., friedrich m., grootes p.m. et al. (2013) intcal13 and marine13 radiocarbon age calibration curves 0–50,000 years cal bp. radiocarbon, 55 (4), 1869-1887. sannikov s.n., goldammer j.g. (1996) fire ecology of pine forests of northern eurasia. in (goldammer j.g. & furyaev v.v. , eds.) fire in ecosystems of boreal eurasia. forestry science, 48, 151-167. kluwer academic publishers, dordrecht. 97 palaeoenvironments of the central po plain 33 30 ka cal bp << <<< ------------ fig. 3 (upper panel) palaeobotanical proxies, pollen zonation and radiocarbon ages obtained from the compressed peat layer at casaletto ceredano, lower adda river valley, central po plain, plotted against stratigraphy. (lower panel) summary palaeobotanical proxies (arboreal pollen; sum of xerophytes i.e. artemisia, ephedra, chenopodiaceae, hippophaë; sieved charcoal) plotted against chronology and compared with isotope and dust proxies from the ngrip core. ms. received: may 4, 2018 final text received: may 16, 2018 98 microsoft word 11_furlani + revisori_lm05.doc available online http:/amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 25 (2), 2012, vii-ix the geoswim project: snorkel-surveying along 250 kilometres of the southern and western istrian coast stefano furlani department of mathematics and geosciences, university of trieste, italy corresponding author: s. furlani <sfurlani@units.it> the northeastern adriatic coast is dominated by high limestone plunging cliffs or slopes at wide-ranging angles. several authors (fouache et al., 2000, antonioli et al., 2004, 2007; furlani et al., 2011a) reported the occurrence of a well-carved submerged tidal notch at about -0.5/-0.7 m m.s.l. in the central part of the istrian peninsula, in correspondence of the limski kanal. moreover, furlani et al. (2011b) studied the coastal features of the northwestern sector, in particular the genesis and development of shore grykes. anyway, observation carried out along these rocky coasts, but also in general along all the rocky coasts of the world, are punctual and relative to short coastal sectors. as a consequence, it prevents the possibility to provide a global view of the surveyed coastal area. the geoswim project, of the department of mathematics and geosciences of the university of trieste, allowed to survey the morphological features of the whole southern and western istrian coast (fig. 1), like notches, sea caves, coastal assemblages of pinnacles, potholes, etc., and to collect physical parameters during the surveying. the northwestern istrian coast is dominated by limestones spanning in time spanning in time from the late jurassic to the eocene (velić et al., 2002, ). nearly horizontal or slightly inclined limestone bedding planes outcrop all over the western istria. limestone beds thickness is higher in correspondence of the limski kanal, in the central and most ancient part of istria (vlahović et al., 2005). n departur arrival km 1 sisan liznijan 6 2 liznijan kamp medulin 11 3 kamp medulin pomer 8 4 pomer kamp stupice 8 5 kamp stupice premantura 14 6 premantura banjole 11 7 banjole stoja 12 8 stoja pula 9 9 pula peroj 8 10 peroj bale 13 11 bale rovinj south 8 12 rovinj south rovinj north 10 13 rovinj north valalta 7 14 koversada zelena laguna 11 15 zelena laguna porec 7 16 porec cervar 13 17 cervar mirna 9 18 mirna novigrad 6 19 novigrad daila 8 20 daila sv. pelegrin 7 21 sv. pelegrin umag 8 22 umag savudrija 9 23 savudrija kanegra 7 24 kanegra strunijan 8 25 strunijan koper 12 26 koper san bartolomeo 6 26 san bartolomeo trieste 12 total lenght 250,17 fig. 1 left side: the study area. red and green lines are the laps. right side: the route and the length of the laps. furlani s. viii from a geomorphological point of view, the study area can be classified as a dalmatian coast (holmes, 1965). high plunging cliffs dominate the southwestern and the central part of the western istria, while the northern and southern coast is interested by limestone coastal slopes plunging at wide-ranging angles. the surveying was carried out along 260 km of coast during july 2012 using mask and fins. it can be considered a snorkeling surveying. the route was covered in 27 days (tab. 1), from šišan, in croatia, to trieste, in italy. two cameras, located on a 1.2 m boat specifically adapted for the project (fig. 2a, b), a canon g12 set in an underwater housing and the latter a 3d gopro camera, allowed to collect an ongoing video of large part of the istrian coast, both above and below sea level. moreover, a ctd-diver produced by eijkelkamp was pull in order to collect temperature and conducibility data along the coast. data collected, together with the video acquisition, allowed to accurately map the submerged notch and other coastal features, such as sea caves (fig. 3), potholes, etc, along the whole surveyed coast. data show that the submerged notch is confined to the central part of the istrian peninsula (fig. 4), the area where it was previously pointed out. the preliminary processing of physical data, even if they was strongly affected by the total lacking of rains during the surveying period, seem to indicate the occurrence of few large submarine springs in the same area of the occurrence of the submerged notch. future processing of recorded data and their mutual comparison will allow to precisely define the occurrence of limestone coastal features and their relations to coastal topography and physical seawater parameters. acknowledgements my acknowledgements go to many people who acfig. 2 a) preparation of the boat used during the surveying in southern istria (photo e. zavagno); b) surveying of coastal features and physical parameters of the sea near poreč (croatia). fig. 4 submerged tidal notch along the northeastern adriatic coast. the picture is made as a stereoscopic 3d as the results using filters of different colors, in this case red and cyan. red and cyan glasses are recommended to correctly view this image. fig. 3 a sea cave at premantura (croatia), in the southern sector of the istrian peninsula. the geoswim project: snorkel-surveying along istrian coast   ix tively participated at different stages of the scientific project, in particular prof. franco cucchi of the department of mathematics and geosciences of the university of trieste for the ongoing support, rados furlani for the assistance in the assemblage of the boat, sara biolchi, livio dorigo, giulio guglielmi, gaia cusatelli, federico furlani, roberto odorico, luca terribili, martina zaccariotto and enrico zavagno for the assistance during the swim-survey operations and many others. many thanks to the “riserva marina di miramare”, the “circolo istria” and the “istituto nautico di trieste” for the assistance before and after the survey. references antonioli f., carulli g.b., furlani s., auriemma r., marocco r. (2004) the enigma of submerged marine notches in northern adriatic sea. quaternaria, 8, 27-36. antonioli f., anzidei m., lambeck k., auriemma r., gaddi d., furlani s., orrù p., solinas e., gaspari a., karinja s., kovacic´ v., surace l. (2007) sea level change during holocene from sardinia and northeastern adriatic (central mediterranean sea) from archaeological and geomorphological data. quaternary science reviews, 26, 2463-24. faivre s., fouache e., ghilardi m., antonioli f., furlani s., kovačić v. (2011) relative sea level change in istria (croatia) during the last 5 ka. quaternary international, 232, 132-143. fouache e., faivre s., dufaure j-j., kovačić v., tassaux f. (2000) new observations on the evolution of the croatian shoreline between poreč and zadar over the past 2000 years. zeitschrift für geomorphologie suppl.-bd. 122, 33-46. furlani s., chersicla d., bressan g., biolchi s., cucchi f. (2011) shore grykes along the western istrian coast. acta carsologica, 40/1, 29-42. furlani s., cucchi f., biolchi s. & odorico r. (2011b) notches in the northern adriatic sea: genesis and development. quaternary international, 232, 158-168. furlani s., cucchi f., biolchi s. (in press) late holocene widening of karst voids by marine processes in partially submerged coastal caves (northeastern adriatic). geografia fisica e dinamica quaternaria. in press. holmes a. (1965) principles of physical geology. new york, ronald press. velić, i., vlahović, j., matičec, d. (2002) depositional sequences and palaeogeography of the adriatic carbonate platform. società geologica italiana, memorie, 57, 141-151. vlahović, i., tisljar, j., velić, i., matičec, d. 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<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> 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<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> /ita (utilizzare queste impostazioni per creare documenti adobe pdf adatti per visualizzare e stampare documenti aziendali in modo affidabile. i documenti pdf creati possono essere aperti con acrobat e adobe reader 5.0 e versioni successive.) /enu (use these settings to create adobe pdf documents suitable for reliable viewing and printing of business documents. created pdf documents can be opened with acrobat and adobe reader 5.0 and later.) >> >> setdistillerparams << /hwresolution [1200 1200] /pagesize [396.850 566.929] >> setpagedevice microsoft word 00_indice_bm03 available online http:/amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 25 (1), 2012, 25-33 how homogeneous are microwear patterns on a fossil horse tooth? preliminary test on a premolar of equus altidens from barranco leon 5 (spain) andrea maria francesco valli1,2, maria rita palombo3,2 & maria teresa alberdi4 1 78 rue du pont ginguet, 03000 moulins sur allier (france) 2 istituto italiano di paleontologia umana, rome (italy) 3 dipartimento di scienze della terra, università “sapienza” and cnr, istituto di geologia ambientale e geoingegneria, rome (italy) 4 departamento de paleobiologia, museo nacional de ciencias naturales, csic, madrid (spain) corresponding author: a.m.f. valli <andrea_vallifr@yahoo.fr> abstract: microwear patterns of twenty seven points on the enamel surface of a fossil horse tooth (upper p3-4; equus altidens granatensis, late early pleistocene, barranco leon 5, guadix-baza basin, spain) were analysed by a correspondence analysis test with the dual aim of testing the suitability of this premolar in analysing microwear of horses, and of analysing how consistent the microwear patterns are across different micro-areas on a single cheek tooth. the results obtained stress that remarkable differences in dental scars are restricted to few zones. the microwear patterns of the lingual enamel surface of the paracone, the point classically analysed on upper m2 for studying microwear in ruminants, and of the pli caballin are the most consistent with those of the other analysed micro-areas. the pattern of dental microwear shown at these points by the upper p3-4 of equus altidens granatensis from barranco leon 5 is closer to those shown by seasonal mixed feeders than of those by strict grazers. keywords: equidae, guadix-baza basin, late early pleistocene, microwear analysis, spain. 1. introduction analysis of dental wear, particularly the microscopic marks produced during chewing on occlusal enamel surfaces, both by tooth/food (abrasion) and tooth/tooth (attrition) interaction, is among the most significant tools applied by palaeontologists to infer dietary behaviour and the environmental context of extinct herbivore mammals. during the last forty years studies on this subject studies have more and more enhanced and new methodological approaches have continuously been developing (e.g. gordon, 1984; teaford, 1986; young & marty, 1986; hayek et al., 1991; solounias & moelleken, 1992; franz-odendaal & solounias, 2004; semprebon et al., 2004; merceron & ungar, 2005; merceron et al., 2005, 2006, 2007; palombo et al., 2005; charles et al., 2007; schubert et al., 2006; scott et al., 2006; demiguel et al., 2008; ungar et al., 2008, in press; valli & palombo, 2008, merceron et al., 2010; schulz et al., 2010, and references therein). although the use of microwear analysis undoubtedly is an useful tool in palaeoecological studies, thus far, few or no studies have been performed trying to test differences (if any) in microwear patterns shown by wear facets formed during the different masticator phases (but see for example gordon, 1982; schulz et al., 2010). butler (1972) first described the mastication process of herbivore mammals, and mapped the position of wear facets and the direction of the striae formed during the two phases of the power stroke of the masticatory cycle: phase i, when vertical movements prevail up to centric occlusion and phase ii, when the initial vertical movements become horizontal and finally downward out of the occlusal contact. following butler’s (1972) idea, other authors (see e.g. hiiemae, 1978; janis, 1979, 1990; rensberger et al., 1984; joomun et al., 2008) investigated the progression of the check tooth pattern. they recognized that in phase i, shearing is predominant, while in phase ii, grinding prevails. however, in hypsodont grazing ungulates, shearing becomes predominant and phase ii tends to be lost (janis, 1979). pleistocene equus representatives have generally been regarded as typical grazers, because the microwear pattern of the lingual side of the paracone of the second upper molar (m2), the canonical point to perform analysis (see below), consists of fine, nearly parallel scratches, few pits, and no or very few gouges, and the number of scratches definitively outnumbers to the number of pits. this has been regarded as an important factor in distinguishing grazers from browsers (e.g. solounias & semprebon, 2002). therefore, equus cheek teeth seem to be particularly appropriate to test the consistency of microwear patterns across the whole occlusal enamel surface, because most of its surface is affected by shearing only (e.g. janis, 1979), avoiding disturbances related to the presence of enamel scars produced by differently oriented masticator forces. examination of microwear in equids, as well as in ruminants, has generally been carried out on the enamel surface of the paracone of m2 by means of a either a scanner microscope or stereomicroscope (solounias & moelleken, 1993; mainland, 1998; solounias & semprebon, 2002; rivals et al., 2008, mihlbachler et al., 2011 valli a.m.f. et al. 26 and references in those papers). however, in equids, the attrition/abrasion forces differentially affect the enamel surface of the cheek teeth because chewing pressures may vary along the tooth row. the anterior and posterior edges of the tooth row participate less in food processing, therefore very anterior and posterior teeth are affected by a more pronounced attrition (tooth to tooth contact), with higher pressures on molars than on premolars. taking into account the peculiar development of anterior/posterior tilts characterising cheek teeth in horses, analysing the occlusal surface of p4 and m1 could be particularly appropriate in inferring dietary behaviour because, in these teeth, the main stress is almost perpendicular to the tooth mesio-distal axis, thus the enamel prisms are not much affected by this tooth tilt. this is the reason why we have decided to analyze the microwear patterns on several points of the enamel of an upper premolar in the twofold aim of investigating on the suitability of the p3-4 in inferring dietary behaviour of fossil horse, and testing the consistency of the microwear patterns on the whole enamel occlusal surface of a grazer. we have chosen to carry out the test on an extraordinarily well preserved upper premolar (either p3 or 4) of a stenonoid horse, equus altidens granatensis, from barranco leon 5 (late early pleistocene, guadix-baza basin, spain, alberdi, 2010) (fig. 1). this species has been regarded as a grazer (alberdi, 2010; alberdi & palombo, 2012 and references therein) therefore the arrangement of enamel scars on the whole enamel of the tooth occlusal surface should be roughly constant. although we are aware that, due the intrinsic characteristic of the microwear methods, reliable results can be obtained only by analysing a statistically consistent sample, we consider to preliminarily test the soundness of the method as a first fundamental step before developing and improving the study by means of an adequate number of specimens. 2. materials and methods analysis was performed on a left upper premolar (either p3 or p4 = p3-4; catalogue number: bl02 31 1692) from the latest early pleistocene fossiliferous deposit of barranco leon 5 (gaudix-basin, spain, blain et al., 2011; duval et al., 2009; toro-moyano et al., 2009). the specimen, stored at the museum of orce (granada, spain), has been chosen because of its good preservation status, allowing the whole surface of the enamel to be analysed. observations were done directly on the tooth at 500x magnification, using the quanta200 fei sem at 25 kv (museo nacional de ciencias naturales, madrid). quantitative analysis was performed using the microwear 4.02 software program (ungar, 2001) on a surface of 500x450 µm². scars are categorised as pits if their width to length ratio is > 1/4 and scratches if their width to length ratio is < 1/4 (solounias et al., 1988; teaford, 1988; solounias & hayek, 1993). pits are considered to be “large” or “small” according to their maximum diameter (whether it exceeds 15 μm or not; merceron et al., 2004). scratches are described as “coarse” (=“wide”) or “fine” according to their width (whether it exceeds 15 μm or not; merceron et al., 2004). they are also categorised as “long” or “short” depending on their length (whether it is equal to or longer than 250 μm, or less than this value; the scars which could extend out of the field of the picture have not been considered; valli & palombo, 2008). the number of “gouges” (scars deeper and several times larger than large pits with irregular outlines; solounias & semprebon, 2002), and “cross scratches” (defined as the number of crosses among the scratches, independent of their orientation) were counted. fig. 1 position of the fossil deposit of barranco leon 5 (bl5; guadix-baza basin, spain; modified from alberdi, 2010). the white area represents the guadix-baza basin. fig. 2 left upper p3-4 (bl02 31 1692) of equus altidens granatensis from barranco leon 5, spain. the numbers indicate the points (loci) where the microwear analyses have been carried out. how homogeneous are microwear patterns on a fossil horse tooth? preliminary … 27 pits scratches gouges large small tot length sd width sd % short fine long fine long coarse tot length sd width sd % cross point 1 2 7 9 4.14 2.48 1.87 0.93 13.85 49 6 1 56 31.35 27.71 1.07 0.60 86.15 38 1 point 2 0 41 41 2.78 1.27 1.33 0.35 26.11 116 3 0 116 16.70 19.32 0.82 0.33 73.89 51 0 point 3 0 53 53 2.06 0.80 1.03 0.31 35.33 97 0 0 97 16.65 13.27 0.89 0.41 64.67 46 0 point 4 0 34 34 2.37 1.73 1.12 0.60 15.38 181 6 0 187 16.99 18.99 0.81 0.41 84.62 85 0 point 5 0 31 31 1.98 1.37 1.06 0.43 24.80 91 3 0 94 19.27 17.67 0.94 0.45 75.20 38 0 point 6 0 13 13 1.93 0.78 0.99 0.41 13.00 81 5 1 87 22.18 24.47 0.89 0.56 87.00 28 0 point 7 0 22 22 2.82 1.43 1.34 53,0 17.32 97 8 0 105 22.13 23.26 0.99 0.46 82.68 44 0 point 8 1 5 6 5.00 2.49 2.41 2.19 7.89 64 6 0 70 28.51 27.40 1.03 0.51 92.11 32 0 point 9 3 12 15 3.83 4.34 1.74 1.60 15.00 80 4 1 85 22.35 18.71 0.90 0.71 85.00 26 0 point 10 1 23 24 2.06 0.96 1.05 0.43 27.27 57 4 0 64 26.25 22.69 0.85 0.43 72.73 17 0 point 11 1 43 44 2.54 2.33 1.29 0.76 30.77 95 3 1 99 16.70 18.58 0.86 0.60 69.23 19 0 point 12 1 11 12 1.96 0.94 1.32 1.04 21.43 37 7 0 44 34.28 31.51 0.82 0.33 78.57 29 0 point 13 4 13 17 4.45 2.65 2.79 2.21 27.42 42 1 2 45 24.42 24.70 1.15 1.34 72.58 8 2 point 14 0 10 10 2.47 1.65 1.11 0.45 17.54 47 0 0 47 17.15 11.14 0.92 0.40 82.46 11 0 point 15 2 15 17 3.24 2.42 1.67 1.29 20.99 60 4 0 64 22.81 25.56 0.86 0.33 79.01 24 0 point 16 2 17 19 2.91 3.79 1.53 1.59 22.09 65 2 0 67 15.95 22.32 0.74 0.38 77.91 14 0 point 17 1 23 24 2.99 1.92 1.50 1.12 21.82 81 5 0 86 20.31 20.92 0.99 0.52 78.18 33 1 point 18 0 11 11 2.04 0.74 1.10 0.36 16.18 55 2 0 57 18.98 18.44 0.94 0.52 83.82 15 1 point 19 2 27 29 3.81 3.12 1.70 1.14 33.33 50 7 1 58 27.41 29.17 1.14 1.14 66.67 20 0 point 20 1 22 23 2.46 1.35 1.39 0.59 26.74 56 6 1 63 29.00 28.26 1.00 0.77 73.26 58 0 point 21 0 16 16 2.32 1.54 1.50 1.43 21.33 53 6 0 59 28.10 29.57 0.71 0.45 78.67 35 0 point 22 0 14 14 2.15 1.22 1.31 1.05 17.07 61 6 1 68 29.42 25.33 0.88 0.78 82.93 46 0 point 23 0 25 25 1.77 0.72 0.95 0.37 25.25 69 5 0 74 24.58 24.95 0.74 0.48 74.75 35 0 point 24 1 18 19 3.25 3.46 1.32 1.09 22.89 62 1 1 64 19.38 15.16 0.86 0.66 77.11 18 1 point 25 1 11 12 2.60 3.63 1.48 1.89 16.00 60 3 0 63 24.67 17.23 0.86 0.53 84.00 25 0 point 26 0 35 35 2.03 1.17 1.14 0.55 25.55 97 5 0 102 21.20 21.23 0.74 0.42 74.45 35 0 point 27 0 20 20 2.23 24.31 1.07 0.37 32.26 40 2 0 42 26.93 24.31 0.89 0.59 67.74 19 0 m1-2 36-1520 3 34 37 2.60 1.75 1.41 0.69 39.36 55 1 1 57 13.45 7.98 1.09 0.67 60.64 13 2 m1-2 i54 13 4 51 56 2.47 1.25 1.51 0.99 36.36 95 3 0 98 11.81 12.47 0.74 0.29 63.64 19 0 tab. 1 results of the microwear analysis of three teeth of equus altidens granatensis from barranco leon 5. analyses carried out on 27 enamel points of the left upper p3-4 (bl02 31 1692) and on the lingual side of the paracone of m1-2 (specimens bl02 36-1520, right, and bl03 i54 13, left). photomicrographs of the dental occlusal surface were taken at the following points (loci; fig. 2): 1-2 on the parastyle, 3 to 6 on the labial side of the paracone, 7-8 on the metastyle, 9-10 on the labial side of the metacone, 11-13 on the postfossette, 14 to16 on the prefossette, 17-18 on the lingual side of paraloph, 19-20 on the lingual side of protocone, 21 to 23 on the pli caballin, 24 to 27 on the lingual side of the hypocone. the results of the analyses are shown in table 1. results obtained have been compared with those resulting from the analysis of microwear patterns, of two other specimens of e. altidens granatensis from the same locality, a right (bl02 36-1520) and a left (bl03 i54 13) upper molars (both either m1 or m2 = m1-2). in the present study (because of the preservation of the molar surface), only the locus n° 15 has been analysed. the results are shown in table 1. in order to evaluate the consistency of microwear patterns at different points of the enamel on the occlusal surface, as well as to test the significance of differences in pattern found among the examined micro-areas, six independent variables (number of small and large pits; number of short, long coarse and long fine scratches; and number of gouges) were analysed by means of a multivariate analysis test (sokal & rohlf, 2001). the analysis was performed using the correspondence analysis (ca) test of the past software program (hammer et al., 2001), which is especially appropriate for count data, such as ours. 3. microwear patterns on the lingual side of the paracone (locus 15), the microwear pattern shows parallel fine scratches, located mainly at the centre of the analysed micro-area (fig. 3). the inclination with respect to the lingual-labial axis ranges from about 0° to 15°. small pits and more inclined scratches can be detected on the lateral side of the photomicrograph, but scratches are more abundant than pits on the whole of the examined surface (tab. 1). short or very short scratches (scratches with width to length ratio near to 1/4), sometimes not much different from pits, prevail. a few long scratches (≥ 250 μm) are present. some look like they consist of several shorter marks arranged along the same line. cross scratches are fairly abundant, comprising more than one third of the total number of scratches (24 against 64; tab. 1). the microwear patterns of other analysed microareas are roughly comparable, but some differences are detectable especially with regards to the scratch (always the most numerous) to pit ratio, which varies from 92.11%,on the posterior side of the mesostyle (locus 8), to 64.67% on the labial side of the paracone (locus 3) (tab. 1). short (sometimes very short) scratches and small pits predominate. long scratches are not very abundant. long coarse scratches are scanty, clearly detectable only on about one third of the examined micro-areas particularly on the postfossette and on some loci of the labial and lingual sides of the tooth (tab. 1). gouges, definitely larger than large pits, are rare, with valli a.m.f. et al. 28 only six being found on five points, whilst cross scratches can be locally abundant: their frequency ranges from 52% to 85% (tab. 1). 4. statistical analysis results of statistical analysis are shown in fig. 4 and fig. 5, where the data are plotted into the new coordinates. the eigenvalues and the variance explained for each eigenvector are given in table 2.a. the first three eigenvectors explain 89.06% of the variance. considering new axes 1 and 2 (fig. 4), the position of the loci along axis 1 is directly proportionate to the number of small pits and inversely proportionate to the number of gouges, coarse scratches, large pits, fine and short scratches. the position of the loci on axis 2 is directly proportionate to the number of gouges, coarse scratches, large and small pits and inversely proportionate to the number of short and fine scratches. the more gouges, coarse scratches and large pits are counted in one locus the more it is inclined towards the negative values on axis 1 and the positive values on axis 2 (as for the loci 13, 1 and, in lesser proportion, 24). the more fine scratches and fewer small pits are counted (in the absence of gouges and coarse scratches) the more the locus plots along the negative value of the axis 2 (like locus 8). the central area of the 95% confidence ellipse contains two loci on the prefossette (15 and 16), two on the lingual side of paraloph (17 and 18) and one on the lingual side of protocone (20). very near are positioned loci on the pli caballin (21, 22 and 23), on the lingual side of the hypocone (25), on the prefossette (14, just under locus 15), on the labial side of the metacone (10), and on the lingual side of the hypocone (26). the most peripheral loci from the centre (but still inside the ellipse) are the locus n° 1 (on the parastyle), the n° 3 (on the labial side of the paracone), the n° 8 (on the metastyle), the n° 9 (on the labial side of the metacone), the n° 11 (on the postfossette) and the n°27 (on the lingual side of the hypocone). these loci, except n° 1 and n° 3, fall in the posterior half of the tooth. the locus n° 13, on the postfossette, is the only one falling outside the 95% confidence ellipse. the position of the loci along axis 3 (fig. 5) is directly proportionate to the number of fine scratches, large pits, coarse scratches and small pits and is inversely proportionate to the number of short scratches. the higher the ratio of “fine scratches/short scratches” the more the locus will fall far within the positive values, like loci 12 (which scores “0.19”), 19 (“0.14”), 20(“0.11”), and 21 (“0.11”). the central area of the 95% confidence ellipse contains loci on the labial side of the paracone (5), on the prefossette (15 and 16), on the lingual side of paraloph (17), on the pli caballin (23), on the lingual side of the hypocone (26), and on the parastyle (2). very near are positioned loci on the parastyle (1), on the metastyle (7), on the labial side of the metacone (9 and 10), on the pli caballin (22) and on the lingual side of the hypocone (25). the most peripheral loci are n°12 (on the labial side of the metacone), n°19 (on the lingual side of protocone), and n° 8 (on the metastyle). again, the locus n° 13 is the only one falling outside the 95% confidence ellipse. as in fig. 4, loci 15, 16 and 17 fall within the central area of the ellipse. the loci on the pli caballin (21-23) even if they do not fall within the centre, lie in proximity to the locus n°15, the classical point choose in the microwear analysis, in both fig. 4 and fig. 5. again, some of the most peripheral points are situated on the posterior half of the tooth (8, 11, 13, 24, but not 9, 10). fig. 3 photomicrograph (x500) the point n° 15 (see fig. 2) of the enamel surface of equus altidens granatensis left upper p3-4 (bl02 31 1692). fig. 4 correspondence analysis among 27 points (loci) on a upper p3-4 of equus altidens granatensis. first and second eigenvectors. the 95% confidence ellipse is indicated. how homogeneous are microwear patterns on a fossil horse tooth? preliminary … 29 adding to the multivariate analysis data from specimens bl02 36-1520 and bl03 i54 13, the eigenvectors change slightly (tab. 2.b) but without any substantial change in the general pattern of the setting of analysed loci (fig. 6). in the axis 2 versus axis 3 graphic, the m12 loci fall well inside the 95% confidence ellipse, while in the axis 1 versus axis 2 upper m1-2 (36-1520), it is closer to the border of the 95% confidence ellipse (because of the two gouges found on it). 5. discussions whether the differences in microwear patterns of nearly contiguous enamel areas are related to the intrinsic properties of the food, to the presence of exogenous grit (see inter alios rivals & semprebon, 2006; semprebon & rivals, 2007, 2010), or to stochastic factors connected to the local resistance to tensile and pressure stress during masticatory processes, is a still unsolved question. as equus from barranco leon is concerned, results obtained indicate that the main differences in macrowear patterns (in terms of dental scars among the various areas of enamel on the same tooth) are limited to a few zones of the enamel surface. nonetheless, considering the quite homogeneous masticatory stress across the tooth, its flat occlusal surface, and the processing of a roughly similar food, it is not easy to understand what is producing the inconsistencies among microwear patterns shown by loci close to each other. differences depend mainly on the pits/scratches ratio, but also on presence/absence of coarse scratches, large pits and gouges. the latter two scars are believed to be related to feeding habits that include seeds, hard fruits or even roots (solounias & semprebon, 2002; semprebon et al., 2011) but in the present study, a few gouges and/or large pits might be caused by exogenous grit, swallowed together with food, which locally damaged the enamel surface. indeed, scars herein regarded as “large pits” mainly show a more irregular outline than the outline of the large pits detectable on the teeth of animals whose diet includes seed and hard fruits. on the other hand, the microwear patterns shown by the lingual enamel of the paracone (locus n°15), the point classically chosen for analysing microwear in ruminants, falls very near the central area of the 95% confidence ellipse. as a result, the lingual enamel band of the paracone, can be considered the best point for analysing microwear in equus representatives in m2 as well as in p3-4, according to the results obtained. in addition, on the latter also the pli caballin could be confidently analysed to infer the dietary behaviour of horses. according to our result, if in a sample of horse teeth to be analysed, the number of available m2 is scanty, it is possible to increase the sample size, adding upper p3-4 (see fig. 6). fig. 5 correspondence analysis among 27 points (loci) on a upper p3-4 of equus altidens granatensis. second and third eigenvectors. the 95% confidence ellipse is indicated. fig. 6 correspondence analysis among 27 points (loci) on a upper p3-4 and 2 upper m1-2 of equus altidens granatensis. a) axis 1 versus axis 2. b) axis 2 versus axis 3. the 95% confidence ellipses are indicated. valli a.m.f. et al. 30 fig. 7 bivariate plot of the average number of scratches versus average number of pits for extant browsers, mixed feeders, grazers (data from solounias et al., 2000; aa alces alces, lw litocranius walleri, cd cephalophus dorsalis, be boocercus euryceros, ti tragelaphus imberbis, cn cephalophus niger, ts tragelaphus strepsiceros, oj okapia johnstoni, cs cephalophus sylvicultor, gc giraffa camelopardis, cp capricornis sumatraensis, to taurotragus oryx, gg gazella granti, tr tragelaphus scriptus, gt gazella thomsoni, mm muntiacus muntjak, bt boselaphus tragocamelus, ci capra ibex, ce cervus canadensis, cu cervus unicolor, oc ovis canadensis, ke kobus ellipsiprimnus, ct connochaetes taurinus, tq tetraceros quadricornis, bb bison bison, hn hippotragus niger, ax axis axis, cv cervus duvauceli, oo ourebia ourebi, sc syncerus caffer), left upper p3-4 (bl02 31 1692; 27 loci), right m1-2 (bl02 361520) and left m1-2 (bl03 i54 13) of equus altidens granatensis from barranco leon. numbers = p3-4 loci. tab. 2 eigenvectors of the correspondence analysis test (ca), with respective eigenvalues and % variance, for a) 27 loci on a upper p3-4 of equus altidens granatensis, b) 27 loci on a upper p3-4, and 2 upper m1-2 of equus altidens granatensis. our results are also consistent with those obtained by kaiser t.m. (2002), according to which in hypsodont perissodactyls, like equus, the chewing direction, along the horizontal plane, tends to become exclusively transverse. indeed, the loci which appear as anomalous with respect to the average pattern shown by the microwear of the e. altidens granatensis from baranco leon, are mostly located on the posterior part of the tooth (e.g. loci 11 and 13). despite the reliability of most of the analysed loci with the masticatory stress and movements, some inconsistencies still remain unexplained. for instance, what about loci 24-26, which may possibly fall within the phase ii area, albeit they show a pattern different from that of other loci of the same area? why does locus 3 present a microwear pattern so different from locus 2, which is located on the same enamel band? could these differences have explained by a different orientation relative to the chewing direction? finally, how many stochastic factors, such as the ingestion of sediments particles, may affect microwear patterns? results obtained, albeit preliminary, on the one hand stress once more the individual variation in food assumption and consumption, as well as the need of large samples and the support of complementary analyses – such as mesowear (kaiser et al., 2000; kaiser & forteluis, 2003) and stable isotopes (e.g., cerling et al., 1997; mihlbachler et al., 2011) – to validate inferences drawn by microwear analysis. on the other hand, they indicate the potential efficacy of the additional test herein proposed to better understand the reliability and limits of microwear analysis. 6. palaeodietary interferences as far as the diet of the horse from barranco leon 5 is concerned, plotting the number of scratches of this horse and extant ruminants (data from solounias et al., 2000) versus the number of pits, our data forms a main cloud lying between the grazing and the mixed feeding taxa (fig. 7). a few loci are nested inside the grazers, a few inside the mixed feeders and some are scattered over both groups. only locus 4 (on the labial edge of the paracone) falls far from the others, because of its large number of scratches (tab.1). loci on the prefossette (15 and 16), and on the pli caballin (22 and 23) fall between grazers and mixed feeders, with locus 22 nearest to the second group. all in all, the pattern of dental microwear shown by e. altidens granatensis from barranco leon 5, for upper p3-4, is closer to those shown by seasonal mixed feeders than by strict grazers. adding the two m1-2, one (bl02 36-1520) falls near a grazer taxon, the other (bl03 i54 13) in the range of the mixed feeders. these data, in the first approximation, can be considered consistent with those analysed on the p3-4. in any case, more data are necessary in order to support the hypothesis of any relationship between the increase in moisture between 1.3 and 1.0 my (blain et al., 2011) pointed out for the localities of barranco leon and the dietary behaviour inferred by microwear analysis. 7. conclusions our study is a preliminary work aimed at understanding the consistencies in microwear patterns on the occlusal surface of dental enamel and the use of single locus for palaeodiatary analyses. our data suggest that the differences, at least for horses, are limited to a few zones. in particular, the lingual side of the paracone, the classic locus chosen for microwear analysis in ruminants and equids, falling at the centre of the distribution obtained, considering all the loci on fig. 2. on our sample, the loci on the pli caballin could also be confidently analysed to infer dietary behaviour. they are all judged consistent with the data obtained on m1-2 from the same locality. results obtained also suggest that the use of p3-4 can be useful in inferring palaeodietary behaviour when the number of available m2 is scanty. how homogeneous are microwear patterns on a fossil horse tooth? preliminary … 31 thus, our analysis shows that microwear methodology could be extended to other loci and teeth in addition to the classic one considered. of course, more data and more studies would be necessary in order to further improve the methodology and fully understand its limits. acknowledgements we have to thank to tormo l. (quanta200 fei sem; museo nacional de ciencias naturales, madrid) for her help in analysing samples, hammer ø., for his helpful discussions and advices on statistical analysis, and rivals f. and an anonymous referee for useful comments that contributed to improving the quality of the manuscript. haire s. revised the english text. work supported by the biodiberia project of the european commission human potential programme (2004). references alberdi m.t. (2010) estudio de los caballos de los yacimientos de fuente nueva-3 y barranco león-5 (granada). in: toro i., martínez-navarro b. & agustí j. (eds.): ocupaciones humanas en el pleistoceno inferior y medio de la cuenca de guadixbaza. arqueología monografías, junta de andalucía, consejería de cultura, 6, 291-30. alberdi m.t., palombo m.r. (2011) the late early to early middle pleistocene stenonoid horses from italy. quaternary international, doi:10.1016/j.quaint. 2011.12.005. blain h.g., bailon s., agustí j., martínez-navarro b., toro i. (2011) paleoenvironmental and paleoclimatic proxies to the early pleistocene hominids of barranco león d and fuente nueva 3 (granada, spain) by means of their amphibian and reptile assemblages. quaternary international, 243, 44-53. butler p.m. (1972) some functional aspects of molar evolution. evolution, 26, pp. 474-483. cerling t.e., harris j.m., macfadden b.j., leakey m.g., quadek j., eisenmann v., ehleringer j.r. (1997) global vegetation change through the miocene/pliocene boundary. nature, 389, 153-158. charles c., jaeger j.-j., michaux j., viriot l. (2007) dental microwear in relation to changes in the direction of mastication during the evolution of myodonta (rodentia, mammalia). naturwissenschaften, 94, 71-75. demiguel d., fortelius m., azanza b., morales j. (2008) ancestral feeding state of ruminants reconsidered: earliest grazing adaptation claims a mixed condition for cervidae bmc evolutionary biology, 8, 1-13. duval m., falguères c., bahain j.j., voinchet p., grün r., aubert m., agustí j., martínez-navarro b., toro i. (2009) esr dating of the lower pleistocene sites of orce (guadix-baza basin, andalusia, spain): fuente nueva iii, barranco león and venta micena. abstracts and field trip guide, 2009 annual meeting seqs, the quaternary of southern spain: a bridge between africa and the alpine domain, september 28th-october 3rd, 2009. 24, orce and lucena. franz-odendaal t.a., solounias n. (2004) comparative dietary evaluations of an extinc giraffid (siva-therium hendeyi) (mammalia, giraffidae, sivatheriinae) from langebaanweg, south africa (early pliocene). geodiversitas, 26, 675-685. gordon k.d. (1982) a study of microwear on chimpanzee molars: implications for dental microwear analysis. american journal of physical anthropology, 59, 195-215. gordon k.d. (1984) hominoid dental microwear: complications in the use of microwear analysis to detect diet. journal of dental researches, 63, 10431046. hammer ø., harper d.a.t., rayan p.d. (2001) paleontological statistics software package for education and data analysis. palaeontologia electronica, 4, 1-9. hayek l.-a., bernor r.l., solounias n., steigerwald p. (1991) preliminary studies of hipparionine horse diet as measured by tooth microwear. in: forsten a. (ed.): björn kurtén memorial volume. annales zoologici fennici, 28, 187-200. hiiemae k.m. (1978) mammalian mastication: a review of the activity of the jaw muscles and the movements they produce in chewing. in: butler p.m. & josey k. (eds.): development, function and evolution of teeth. academic press, 359-398. janis c.m. (1979) mastication in the hyrax and its relevance to ungulate evolution. paleobiology, 5, 50-59. janis c.m. (1990) the correlation between diet and dental wear in herbivourus mammals, and its relationship to the determination of the diets in extinct species. in: boucot, a.j. (ed.): evolutionary paleobiology of behavior and coevolution. elsevir science, 241-259. joomun s.c., hooker j.j., collison m.e. (2008) dental wear variation and implications for diet: an example from eocene perissodactyls (mammalia). palaeogeography, palaeoclimatology, palaeoecology, 263, 92-106. kaiser t.m. (2002) functional significance of ontogenetics gradients in the enamel ridge pattern of the upper cheek dentition of the miocene hipparionin horse cormohipparion occidentale (equidae, perissodactyla). senckenbergiana lethaea, 82, 167180. kaiser t.m., fortelius m. (2003) differential mesowear in occluding upper and lower molars: opening mesowear analysis for lower molars and premolars in hypsodont horses. journal of morphology, 258, 67-83. kaiser t.m., solounias n., fortelius m., bernor r.l., schrenk f. (2000) tooth mesowear analysis on hippotherium primigenium from the vallesian dinotherien-sande (germany) a blind test. carolinea, 58, 104-114. mainland i.l. (1998) dental microwear and diet in domestic sheep (ovis aries) and goats (capra hircus): distinguishing grazing and fodder-fed ovicaprids using a quantitative analytical approach. journal of archaeological science, 25, 1259-1271. merceron g., blondel c., de bonis l., koufos g.d., viriot l. (2005) a new method of dental microwear analysis: application to extant primates and ouranopithecus macedoniensis (late miocene of greece). palaios, 20, 551-561. valli a.m.f. et al. 32 merceron g., blondel c., brunet m., sen s., solounias n., viriot l., heintz e. (2004) the late miocene paleoenvironment of afghanistan as inferred from dental microwear in artiodactyls. palaeogeography, palaeoclimatology, palaeoecology, 207, 143163. merceron g., blondel c., viriot l., koufos g.d., de bonis l. (2007) dental microwear analysis of bovids from the vallesian (late miocene) of axios valley in greece: recosntruction of the habitat of ouranopithecus macedoniensis (primates, hominoidea). geodiversitas, 29, 421-433. merceron g., escarguel g., angibault j.-m., verheydentixier h. (2010) can dental microwear textures record inter-individual dietary variations? plos one, 5, 1-9. merceron g., taylor s., scott r.s., chaimanee y., jaeger j.-j. (2006) dietary characerisation of the hominoid kharatpithecus (miocene of thailand): evidence from dental topographic and microwear etxture analyses. naturwissenschaften, 93, 329333. merceron g., ungar p.s. (2005) dental microwear and palaeoecology of bovids from the early pliocene of langebaanweg, western cape province, south africa. south africa journal of science, 101, 365370. mihlbachler m.c., rivals f., solounias n., semprebon g.m. (2011) dietary change and evolution of horses in north america. sciences, 331,11781181. palombo m.r., filippi m.l., iacumin p., longinelli a., barbieri m., maras a. (2005) coupling tooth microwear and stable isotope analyses for paleodiet reconstruction: the case study of late middle pleistocene elephas (palaeoloxodon) antiquus teeth from central italy (rome area). quaternary international, 126-128, 153-170. rensberger j.m., forsten a., fortelius m. (1984) functional evolution of the cheek tooth pattern and chewing direction in tertiary horses. paleobiology, 10, 439-452. rivals f., semprebon g.m. (2006) a comparison of the dietary habits of a large sample of the pleistocene pronghorn stockoceros onusrosagris from the papago springs cave in arizona to the modern antilocapra americana. journal of vertebrate paleontology, 26, 495-500. rivals f., schulz e., kaiser t.m. (2008) climaterelated dietary diversity of the ungulate fauna from the middle pleistocene succession (ois 14-12) at the caune de l’arago (france). paleobiology, 34, 117-127. schubert b.w., ungar p., sponheimer m., reed k.e. (2006) microwear evidence for plio-pleistocene bovid diets from makapansgat limeworks cave, south africa. palaeogeography, palaeoclimatology, palaeoecology, 241, 301-319. scott r.s., ungar p.s., bergstrom t.s., brown c.a., childs b.e., teaford m.f., walker a. (2006) dental microwear texture analysis: technical considerations. journal of human evolution, 51, 339-349. schluz e., calandra i., kaiser t.m. (2010) applying tribology to teeth of hoofed mammals. scanning, 32, 162-182. semprebon g.m., janis c.m., solounias n. (2004) the diets of the dromomerycidae (mammalia: artidactyla) and their response to miocene vegetational change. journal of vertebrate paleontology, 24, 427-444. semprebon g.m., rivals f. (2007) was grass more prevalent in the pronghorn past? an assessment of the dietary adaptations of miocene to recent antilocapridae (mammalia: artiodactyla). palaeogeography, palaeoclimatology, palaeoecology, 253, 332-347. semprebon g.m., rivals f. (2010) trends in the paleodietary habits of fossil camels from the tertiary and quaternary of north america. palaeogeography, palaeoclimatology, palaeoecology, 295, 131-145. semprebon g.m., sise p.j., coombs m.c. (2011) potential bark and fruit browsing as revealed by stereomicrowear analysis of the peculiar clawed herbivores known as chalicotheres (perissodactylla, chalicotherioidea). journal of mammalian evolution, 18, 33-55. sokal, r.r., rohlf, f.j. (2001) biometry. w.h. freeman and company, 3rd ed., 1-887. solounias n., hayek l.-a. (1993) new methods of tooth microwear analysis and application to dietary determination of two extinct antelopes. journal of zoology, 229, 421-445. solounias n., mcgraw m.s., hayek l.-a., werdelin l. (2000) the paleodiet of giraffidae. in: vrba e.s. & schaller g.b. (eds.): antelopes, deer, and relatives. fossil record, behavioral ecology, systematics, and conservation. yale university press, 8495. solounias n., moelleken s.m.c. (1992) tooth microwear analysis of eotragus sansaniensis (mammalia: ruminantia) one of the oldest known bovid. journal of vertebrate paleontology, 12, 113-121. solounias n., moelleken s.m.c. (1993) tooth microwear and premaxillary shape of an archaic antelope. lethaia, 26, 261-268. solounias n., semprebon g. (2002) advances in the reconstruction of ungulate ecomorphology with application to early fossil equids. american museum novitates, 3366, 1-49. solounias n., teaford m.f., walker a. (1988) interpreting the diet of extinct ruminants; the case of a nonbrowsing giraffid. paleobiology, 14, 443-457. teaford m.f. (1986) dental microwear and diet in two species of colobus. in: else j., lee p. (eds.): proceedings of the tenth annual international primatological conference. volume 2: primate ecology and conservation. cambridge university press, 63-66. teaford m.f. (1988) a review of dental microwear and diet in modern mammals. scanning microscopy, 2, 1149-1166. toro-moyano i., de lumley h., fajardo b., barsky d., cauche d., celiberti v., grégoire s., martineznavarro b., espigares m.p., ros-montoya s. (2009) l’industrie lithique des gisements du pléistocène inférieur de barranco león et fuente nueva 3 à orce, grenade, espagne. l’anthropologie, 113, 111-124. ungar p.s. (2001) microwear software, version 4.02. a semi-automated image analysis system for the how homogeneous are microwear patterns on a fossil horse tooth? preliminary … 33 quantification of dental microwear. available on web. ungar p.s., krueger k.l., blumenschine r.j., njau j., scott r.s. (2011) dental microwear texture analysis of hominins recovered by the olduvai landscape paleonthopology project, 1995-2007. journal of human evolution, doi:10.1016/j.jhevol. 2011.04.006. ungar p.s., scott r.s., scott j.r., teaford m. (2008) dental microwear analysis: historical perspectives and new approaches. in: irish j.d. & nelson g.c. (eds.): technique and application in dental anthropology. cambridge university press, 389-425. valli a.m.f., palombo m.r. (2008) feeding behaviour of middle-size deer from the upper pliocene site of saint-vallier (france) inferred by morphological and micro/mesowear analysis. palaeogeography, palaeoclimatology, palaeoecology, 257, 106-122. young w.g., marty t.m. (1986) wear and microwear on the teeth of a moose (alces alces) population in manitoba, canada. canadian journal of zoology, 64, 2467-2479. ms. received: january 31, 2012 final text received: february 21, 2012 available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 73 78 now or never: the study of disappearing ice archives in the time of global warming daniela festi free university of bozen-bolzano, faculty of science and technology, bolzano, italy university of innsbruck, department of botany, innsbruck, austria corresponding author: d. festi <daniela.festi@uibk.ac.at> abstract: mountain glaciers in the alps can provide detailed information on past climatic conditions. regrettably, their persistence is currently threatened by the ongoing warming. this situation generates public concern and the need to recover and preserve ice cores before their stratigraphy is permanently compromised. this contribution reports on recent ice core drillings in the eastern alps implementing new approaches to directly link the climatic signal retained in the ice with the palaeo-environmental component of the ice. keywords: pollen, environmental dna, mountain glacier, cryopalynology, ice cave, timescale 1. introduction since the first signs of global warming have been recognised, the scientific community committed to provide evidence of past and current climate change, as well as an understanding of its causes, to support policymakers and governments in their decisions. in the frame of these investigations, it has been recognised that the warming is particularly severe in the european alps, where temperature is rising at twice the global rate (ipcc 2013). the rapid retreat of alpine glaciers is probably the most striking evidence of the drastic effects of the ongoing climate warming. recent estimations speculate that european glaciers experienced a loss in ice volume of 49% in the period 1900-2011 (huss, 2012). their retreat has a considerable impact on both the scientific community and the public, as it can be witnessed on a timescale as small as a lifetime (diolaiuti et al., 2012). this situation clearly generates public and scientific concern, creating an urgent need for detailed investigation of glacier content, before the ice bodies become permanently compromised. it is, indeed, a “now or never’’ situation, as the increased summer ablation, leading to progressive percolation, is already compromising the integrity of glaciers as palaeo-archives. furthermore, while the vanishing of the surface cryosphere is evident, the decline of the underground cryosphere is less striking, yet equally concerning. ice masses hosted in caves have a great potential for palaeo-environmental studies (e.g. luetscher et al., 2005), providing complementary information to mountain glaciers, as they occur at lower altitudes and generally, where surface glaciation is altogether missing (kern & perşoiu 2013). in the past decades, main efforts of ice cores studies in the alps converged on the western part of the mountain range (i.e. monte bianco and monte rosa massifs, icb, http://geomatic.disat.unimib.it), because of their higher elevation, which let presume the possibility of retrieving intact ice records. in the eastern alps little research has been done (i.e. vernagtferner, von gunten et al., 1982). finally, the approach used to study glacier ice cores considerably resembled that developed for polar ice caps, which was established to obtain quantitative palaeo-climatic reconstructions. this practice has given little attention to the biological proxies present in the ice, e.g. pollen (vareschi, 1934; bortenschlager 1970) and left highly unexplored the possibility of directly linking climatic and environmental evidence enclosed in glaciers. this gap has finally been recognised by both ice core scientists and palaeo-ecologists, who began developing new approaches, to exploit glacier ice in a more comprehensive way, including well established palaeo-environmental proxies, e.g. pollen, as well as new generation proxies, e.g. environmental dna (edna). the present contribution, based on published data and personal engagement in ongoing research projects, reports on: i) filling the gaps in ice core studies in the eastern italian alps; ii) recent advances in pollen as a chronological tool for ice core; iii) the potential of mountain glaciers as palaeo-environmental archives. 2. methods 2.1. filling the gaps in the eastern alps choosing the ideal site is the key of success of every palaeo-climatic and palaeo-ecological study. in a period of climate warming this proves to be a challenging task, especially for ice core drilling in the eastern alps, where glaciers are found at lower elevation. here two drilling sites are presented. the alto dell’ortles glacier is the highest glacier in the eastern alps, with an altitude ranging from 30183905 m a.s.l. the ice body is located close to the border between italy, austria and switzerland (figure 1), on the north-western slope of the mt. ortles, and covers an area of about 1.04 km2 (gabrielli et al., 2012). the features making alto dell’ortles a suitable site for ice core studies in the eastern alps are: i) its high altitude setting; ii) the great thickness of the ice, ca. 75 m; iii) the presence of cold ice (gabrielli et al., 2012); iv) an excellent lamination of the exposed ice layers down to bedrock observed prior to drilling (gabrielli and others, 2010). finally, the glacier is also a good candidate for successful cryopalyhttps://doi.org/10.26382/aiqua.2018.aiquaconference nological analyses, due to the vicinity of the vegetation and the efficient uplift by thermic winds that ensures an effective transport of pollen from the surrounding area. project ortles aims at studying the glacier as an indicator of past and current climate change, and includes the study of pollen, isotopes, major ions, trace elements and levoglucosan as determined in ice cores, as well as the investigation of the glacier physical features and the surrounding permafrost areas. the goal of palynological analysis is to provide a pollen-based timescale of the cores, as well as to explore the potential of pollen analyses in ice core for palaeovegetational and palaeoclimatic reconstructions. the pian di neve glacier covers an 8 km² large plateau located in the adamello massif at an altitude of 3100-3400 m a.s.l. (figure 1). with its ~270 m of depth, it is the deepest italian glacier and, together with the adjacent mandrone glacier, it is also the largest glacier of italy (picotti et al., 2017). pian di neve was chosen as a drilling site for its suitability to study the interactions between climate, biosphere and human activities because of: i) the expected high time resolution due to the mighty ice thickness; ii) the vicinity of vegetation, due to its low altitude, which ensures an input of biological proxies; iii) its vicinity to the high industrialised po plain, which provides a long record of anthropic activity. 2.2. advances in pollen as a chronological tool the classical interpretation of pollen diagrams to detect annual variation in the pollen spectra is not very handy when dealing with thousands of samples, as it is often the case in the analyses of deep ice cores. thus, novel approaches were developed to condense the complex palynological information of the core, and to provide a precise timescale. both methods, hereafter summarised, were developed and tested on a 10 m (459 cm w.e. water equivalent) shallow core retrieved on the alto dell’ortles glacier. the first approach developed by festi et al. (2015) is based on the extraction of the seasonal signal by principal components analysis (pca) of pollen assemblages obtained by high level taxonomical identification (details in festi et al., 2015). this approach allows to extract seasonal components indicative of the original flowering seasons and easily visualise the succession of different seasons (spring, early and late summer) along the core (figure 2 a). the second method is based on a “space-fortime” (or “depth-to-day” substitution) by pollen content of ice samples (depth) and daily pollen monitoring samples (day) of a nearby aerobiological station. by coupling the pollen content of firn/ice samples with the most statistically similar pollen assemblage of the airborne samples, a link can be established between pollen deposition at a specific sample depth on the glacier and a specific day of the year (doy) of the daily monitoring (details on the method in festi et al., 2017). 2.3. ice cores as palaeoenvironmental archives the pian di neve ice core was specifically recovered to obtain environmental information from the ice. calicecalibrating biodiversity in glacier iceis in fact the first ice core project mainly targeting the biological component of the glacier. pollen and plant edna analyses are conducted in order to reconstruct changes in biodiversity during the last 70 years, in relation with climate warming and human impact (changes in land use and practices, industrialisation, etc.). these results will be validated by biodiversity estimates from the region, obtained with remote sensing, historical archives and field surveys. this approach will generate the very first plant diversity record obtained by pollen and dna analyses from an alpine ice core, validated by historical biodiversity assessments. this approach significantly contributes towards the possible exploitation of mountain glaciers as palaeo-ecological archives. however, every palaeo-ecological reconstruction should be established on a deep knowledge on how the proxies are incorporated and build up the signal object of analyses. such processes are poorly investigated for pollen and dna in glaciers. to fill this gap, direct and indirect approaches are possible: i) on site pollen/dna monitoring; ii) combining pollen analyses from ice samples with mass balance modelling. the first approach is currently implemented near the drilling site of pian di neve, where a daily pollen monitoring station has been set up. this data will provide important information on the variations in time of the pollen load transported by the air masses over the glacier, in terms of both quantity and pollen types. this pattern is presumably reflected by changes in pollen spectra and pollen concentration found in the ice. the second and indirect approach was already tested on the alto dell’ortles shallow core (festi et el., 2017) by combining palynological results with the results of mass balance modelling for the drilling site (eismodel, carturan et al., 2012). the mass balance model simulates accumulation and melt processes at hourly time steps. for each snow layer deposited (i.e. the water equivalent that accumulates at the surface of the snowpack during an hourly time step), the model provides its time and date of formation, as well as the air temperature during its deposition (figure 3). for details on eismodel refer to carturan et al. (2012). 74 festi d. fig. 1 map of northern italy showing the location of ice core drilling sites presented: [1] alto dell’ortles glacier; [2] pian di neve glacier, adamello massif. 75 3. results 3.1. filling the gaps in the eastern alps drilling expeditions on both the alto dell’ortles and pian di neve glaciers were successful despite the technical challenges associated with coring temperate glaciers, and a climatic and environmental signal was retained in the ice of both ice bodies. in the frame of the project ortles two coring expeditions led by project leader paolo gabrielli (ohio state university) were conducted. in 2009 a firn core of 10 m (459 cm w.e.) was retrieved, while in 2011 four deep cores of about 75 m (~60 m w.e.) were extracted. the dating of the deep ice cores based on 210pb, tritium, beta activity and 14c analyses, provided a maximum age of the bottom layers of ∼7 ka, during which it is presumed that the drilling site was continuously glaciated on frozen bedrock (gabrielli et al., 2016). pollen analyses have been performed on the short core at 10 cm resolution on 103 samples, and on one of the deep cores (c1) at 10 to 3 cm resolution, leading to ca. 1840 samples. pollen concentration on the long core varied from 0 to 27 grains/ml and about 120 pollen and spore types were identified. the palynological data showed that an annual signal was retained in most of the core. the complete pollen-based timescale is currently being combined with the results of isotopes and dust analyses to accomplish a final multi proxy annual timescale. pian di neve. in the frame of calicecalibrating biodiversity in glacier ice a 42 m core has been retrieved in april 2016 from the centre of the glacier by a drillers team lead by valter maggi (milano bicocca university). first results of pollen analyses on 200 ice samples show a pollen concentration from 0 to about 35 grains/ml. 3.2. advances in pollen as a chronological tool both statistical methods were tested on the alto dell’ortles short core. the pollen content of firn samples (~30ml each) was very variable, and concentration values range from 0 to 47 grains/ml. pollen grains were mostly characterised by an excellent state of preserva the study of ice archives fig. 2 (a) alto dell’ortles firn core 2009 timescale (festi et al., 2015) based on principal component analyses. as every principal component (pc) condenses the seasonal information of the pollen spectrum, scores values should be interpreted as follows: a sample (w.e. depth down) presenting high component scores values for a specific pc is characterised by a pollen content reflecting predominantly the season corresponding to that particular pc. (b) mean date (day of the year ± 1 sigma) obtained by using the depth-to-day method (festi et al., 2017); empty squares represent inversions (c) pollen concentration in the alto dell’ortles 2009 firn core. (d) number and mean thickness (colour scale) of ice lenses per sample (figure from festi et al., 2017). tion, and their identification led to a pollen spectrum of 64 pollen types (for details refer to festi et al., 2015). the seasonal variations reconstructed with both methods are shown in figure 2, together with changes in the concentration of pollen and spores. both methods led to the conclusion that the core includes five years of snow accumulation (2005-2009) and highlight a substantial difference in the pollen distribution patterns in the snow, both within and among flowering seasons. flowering seasons stood out distinctively as layers with high pollen concentration, variable inter-annual thickness and seasonality patterns. according to their thickness and vertical distribution of pollen, the flowering years clustered in two groups: 2005 and 2006 vs. 2007, 2008 and 2009. specifically, the flowering seasons of 2007 and 2008 corresponded to very thick firn layers, into which pollen was distributed with a clear seasonal pattern. in contrast, the flowering seasons of 2005 and 2006 were characterised by a lower firn thickness, the occurrence of a thin lower layer with a distinct spring pollen content, and a thin upper layer containing mixed spring/summer pollen. on the contrary, the “winters” (october to february) were clearly visible as firn layers of different thickness, which are free (or nearly free) of pollen. winter 2007/08 was the thinnest with only 33 cm w.e., followed by 2006/07, 2005/06, and finally 2008/09 with 91 cm w.e. this method allows very precise dating of the time of deposition of snow samples according to their pollen content. ortles deep core. pollen concentration varied from zero to 27 grains/ml and about 120 pollen and spore types were identified. the data show that an annual signal was clearly retained in most the core. the annual timescale is currently under construction by combining the results of pollen, isotopes and dust analyses to refine the depth age model by gabrielli et al. (2016). pian di neve. first results of pollen analyses on 200 ice samples indicate that an annual signal is preserved in the deeper strata of the core. 3.3 ice cores as palaeoenvironmental archives preliminary results of pollen analyses of the pian di neve core indicate a fairly rich palynological diversity, which combined with the ongoing edna analyses will provide a good record of past plant diversity. the pollen spectra were characterised by ca. 80 pollen and spore types, reflecting alpine, subalpine, montane and mediterranean vegetation types. pollen grains of crops (e.g. secale cereale, zea mays) as well as cultivated trees (castanea sativa, juglans regia, olea europaea) and neophytes (ambrosia sp., eucalyptus sp.) also occurred in the analysed samples. diatoms, fungi spores and butterfly scales were among the non-pollenpalynomorphs found in the samples. this supports the hypothesis that analyses of biological proxies on glaciers can generate useful palaeo-environmental record. with respect to the advances in process understanding of the formation of the pollen signal in the ice, comparison between pollen-based timescale and mass balance modelling revealed the great potential of pollen for inferring past climatic conditions at a sub-seasonal resolution in ice core records. based on the pollen content in the alto dell’ortles strata of the shallow core (figure 2), three main types of pollen assemblages could be identified and correlated with the corresponding climatic conditions inferred for by the model for that season: i) thin pollen-rich layers with fairly clear date order but overlapping of principal components (i.e. 2005 and 2006, figure 2). according to the modelling, such layers were the result of intense summer ablation, thus pointing to warm and dry summer conditions; ii) thick layers with substantial pollen concentration and welldistinguished succession of dates (i.e. 2007 and 2008). for these layers the model showed a spring/summer snow deposition generated by copious precipitation and low temperatures, and characterised by negligible melting; iii) thick pollen free layers, reflecting autumn and winter snow deposition. figure 3 shows the comparison of the mass balance reconstructed according to the pollen-based timescale with those by the mass balance model eismodel (festi et al. 2017). remarkably, these are the first results pointing to the potential of pollen to reconstruct not only past vegetation, but also climate conditions and snow deposition patterns. this approach also suggests a high resilience of pollen grains to water percolation, as they seem to persist on the surface of ablation layers. 4. discussion and conclusion the success of the drillings expeditions and ice core analyses on alto dell’ortles and pian di neve glaciers demonstrate that ice bodies in the eastern alps are 76 festi d. fig. 3 comparison of the winter and summer mass balance as obtained by pollen dating and modelling (eismodel). capable of retaining information on past climate, environment and human activities. the date of 7 ka, obtained for the basal ice of the alto dell’ortles, points to the possible presence of ice older than the little ice age, preserved in the deeper parts of the glaciers. in particular, the idea of dating the deepest layers of pian di neve (270 m) is certainly tempting and might lead to unexpected results. the recent advances in pollen-based chronology for ice core prove that accurate analyses can provide reliable annual to sub-seasonal timescales. such studies also indicate that pollen grains are not affected by water percolation like other proxies in the ice (e.g. stable isotopes) and therefore tend to accumulate on the ablation surfaces. future challenges beyond the presented projects include: i) finding new suitable sites for ice core drilling on the alps; ii) recovering endangered ice archives; ii) conserving the ice for future studies; iii) establishing a standard approach including environmental and climatic proxies; iv) expanding the range of investigated ice archives to ice caves as a valid complementary palaeoarchive. the scientific community has already begun to partially address these issues. garzonio et al. (2018) has made the first step towards the development of a methodology to assess the suitability of alpine glaciers for ice core drillings, in order to facilitate the collection of cores with a preserved stratigraphy, while the “protecting ice memory” project has started recovering ice cores from mountain glaciers most at risk (in the alps and the world), and storing them in antarctica for future generations of scientists. finally, the study of ice masses from caves is becoming increasingly important as their suitability for palaeo studies has been recognised. preliminary palynological studies on such ice archives are ongoing in at least two caves located in the eastern alps in the frame of project c3cave’s cryosphere and climate (https:// www.c3project.net) and at the cenote cave (santagata et al., 2017). acknowledgements the author would like to thank all members of the project ortles, calice and pollice consortia, the euregio science fund for financial support to calicecalibrating biodiversity in glacier ice, and the autonome provinz bozen-südtirol, abteilung bildungsförderung, universität und forschung for financial support to the project pamogis (pollen analyses of the mt.ortles ice samples). this is ortles project publication n. 9 and calice publication n 1. references anzidei a.p., bulgarelli g.m., catalano p., cerilli e., gallotti r., lemorini c., milli s., palombo m.r., pantano w., santucci e. (2012) ongoing research at the late middle pleistocene site of la polledrara di cecanibbio (central italy), with emphasis on human-elephant relationships. quaternary international, 255, 171-187. bortenschlager s. (1970) probleme und ergebnisse der untersuchung von pollenspektren im hochgebirge (kesselwandferner, ötztaler alpen, 3240 m). mitteilungen der ostalpin-dinarischen sektion der internationalen vereinigung für vegetationskunde, 10(2), 5-9. carturan l., cazorzi f., dalla fontana g. (2012) distributed mass-balance modelling on two neighboring glaciers in ortles-cevedale, italy, from 2004 to 2009, journal of glaciology, 58, 467-486. diolaiuti g., bocchiola d., d’agata c. smiraglia c. (2012) evidence of climate change impact upn glaciers within the italian alps. theor appl climatol, 109, 429. festi d., carturan l., kofler w., dalla fontana g., de blasi f., cazorzi f., bucher e., mayr v., gabrielli p., oeggl o. (2017) linking pollen deposition and snow accumulation on the alto dell’ortles glacier (south tyrol, italy) for sub-seasonal dating of a firn temperate core. the cryosphere, 11, 93748. festi d., kofler w., buch-er e., carturan l., mair v., gabrielli p., oeggl k. (2015) a novel pollenbased method to detect seasonality in ice cores: a case study from the ortles glacier, south tyrol, italy. journal of glaciology, 61(229), 815-824. gabrielli p., barbante c., bertagna g., bertó m., binder d., carton a., carturan l., cazorzi f., cozzi g., dalla fontana g., davis m., de blasi f., dinale r., dragà g., dreossi g., festi d., frezzotti m., gabrieli j., galos s., ginot p., heidenwolf p., jenk t. m., kehrwald n., kenny d., magand o., mair v., mikhalenko v., lin p. n., oeggl k., piffer g., rinaldi m., schotterer u., schwikowski m., seppi r., spolaor a., stenni b., tonidandel d., uglietti c., zagorodnov v., zanoner t., zennaro p. (2016) age of the mt. ortles ice cores, the tyrolean iceman and glaciation of the highest summit of south tyrol since the northern hemisphere climatic optimum, the cryosphere, 10, 2779-2797. gabrielli p., barbante c., carturan l., cozzi g., dalla fontana g., dinale r., draga g., gabrieli j., kehrwald n., mair v., mikhalenko v.n., piffer g., rinaldi m., seppi r., spolaor a., thompson l.g., tonidandel d. (2012) discovery of cold ice in a new drilling site in the eastern european alps. geografia fisica e dinamica quaternaria, 35, 101105. gabrielli p., carturan l., gabrieli j., dinale r., krainer k., hausmann h., davis m., zagorodnov v., seppi r. and barbante c. (2010) atmospheric warming threatens the untapped glacial archive of ortles mountain, south tyrol. journal of glaciology, 56 (199), 843-853. garzonio r., di mauro b., strigaro d., rossini m., colombo r., de amicis m., maggi v. (2018) mapping the suitability for ice-core drilling of glaciers in the european alps and the asian high mountains. journal of glaciology, 64 (243), 12-26. huss m. (2012) extrapolating glacier mass balance to the mountain-range scale: the european alps 1900-2100, the cryosphere, 6, 713-727. kern z., perşoiu a. (2013) cave ice the imminent 77 the study of ice archives https://www.c3project.net loss of untapped mid-latitude cryospheric palaeoenvironmental archives. quaternary science reviews, 67, 1-7. ippc (2013) climate change 2013: the physical science basis. contribution of working group i to the fifth assessment report of the intergovernamental panel on climate change. stocker t.f. et al eds. cambridge university press, cambridge, uk and new york, usa, pp. 1535. luetscher m., jeannin p., haeberli w. (2005) ice caves as an indicator of winter climate evolution: a case study from the jura mountains. the holocene, 15, 982-993. picotti s., francese r., giorgi m., pettenati f., carcione j. m. (2017) estimation of glaciers thickness and basal properties using the horizontal to vertical spectral ration (hvsr) technique from passive seismic data. journal of glaciology, 63 (238), 229248. santagata t., sauro f., spötl c., festi d., oeggl k., dal molin l., kadded f., camorani m., romeo a. (2017) the cenote project: monitoring a highaltitude ice cave in the dolomites, italy. proceedings of the 17th international congress of speleology, 86-88. vareschi, v. (1934) pollenanalysen aus gletschereis. ber. geobot. inst. rübel, 81-99. von gunten h. r., rössler e., gäggeler h. (1982) dating of ice cores from vernagtferner (austria) with fission products and lead-210. zeitschrift fuer gletscherkunde und glazialgeologie, 1, 37-45. 78 ms. received: may 17, 2018 final text received: may 22, 2018 festi d. amq31 gattiglio comina_22072015 da sostituire.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 28 (1), 2015, 59 70 the involving of the pliocene-pleistocene succession in the t. traversola deformation zone (nw italy) marco gattiglio1, m. gabriella forno1-2, cesare comina1, alfredo doglione1, donata violanti1, diego barbero1 1 earth science department, università di torino, torino, italy 2 natrisk interdipartimental centre, università di torino, grugliasco, italy corresponding author: c. comina<cesare.comina@unito.it> abstract: the n-s trending t. traversola deformation zone (ttdz), developing on the western edge of the asti reliefs, represents one of the most relevant geological features of the piedmont hilly area, in northwestern italy. morphologically this deformation zone corresponds to an evident scarp with, a rectilinear trend in map view, an height up to a hundred meters and a length of about 30 km, delimiting a hilly area (asti reliefs) from a plain area (poirino plateau) developed at averagely higher altitudes. in the western side of the asti reliefs some local differences between the “villafranchian succession” (pliocene-pleistocene) occur across the scarp, together with soft sediment deformations. close to ttdz the sediments (piacenzian and calabrian) are also widely fractured and locally show cataclastic structure. new morphological, stratigraphic, micro-palontological, structural and geophysical data reported in this study better highlight how the ttdz is structurally organized in several n-s trending, sub-vertical right faults with horizontal displacement. in the southern slope of the turin hill the deformation zone probably continues in the moncucco torinese quarry area where it strongly deforms the messinian sediments. the ttdz represents the shallow evidence of a deep right structure that separates the poirino plateau, showing a significant northward shift, from the asti reliefs, where such a shift is less evident. this structure exhibits different deformation magnitude in sediments of different age, suggesting that the tectonic activity took place throughout a long time during post-messinian periods. the ttdz could be also interpreted as part of a structural context related to north-thrusting of the piedmont hills over the po foreland basin. keywords: t. traversola deformation zone, tectonics, piedmont hills, electric resistivity tomography 1. introduction and geological setting this research work regarded two sectors (1 and 2 in fig. 1) located in the central piedmont hilly region (nw italy), where different morphological aspects, plain and reliefs respectively, occur from west to east. in the western side of the asti reliefs (sector 1 in fig. 1) the sedimentary succession is defined by shelf sandy deposits (asti sand), referred to the zanclean, deltaic deposits (“villafranchian” lower complex) and fluvial deposits (“villafranchian” upper complex) separated by the cascina viarengo unconformity (carraro, 1996). the two complexes are referred to the piacenzian and calabrian respectively (dela pierre et al., 2003; forno et al., 2015). above these sediments a widespread silty and locally gravelly fluvial cover of middle and upper pleistocene occurs. these fluvial deposits are linked to the po and tanaro rivers ancient courses (3, 4 and 5 in fig. 2) (forno, 1982). the whole sedimentary sequence is deformed by the asti syncline that consists in a wide e-w regional scale fold developed in the central hilly area (poirino plateau, asti reliefs and alessandria plateau) (boni et al., 1970; carraro et al., 1995) (fig. 1). the axis of this structure is difficult to locate for its different configuration assumed in the time with different locations for the deformed “villafranchian succession” and middle-upper pleistocene fluvial cover (boni et al., 1970; bigi et al., 1990; michetti et al., 2012). in the southern slope of the turin hill (sector 2) the sedimentary succession mainly consists of messinian sediments (fig 1). these are represented by marine sediments and shallow-water primary evaporites, unconformably covered by reworked gypsum deposits and brackish-water to continental sediments (irace, 2004) (see fig. 5). they are overlain by the zanclean deep marine deposits. the messinian succession, gently dipping toward south, displays a severe disruption, due to the occurrence of nnw-sse striking transpressive faults systems, whose activity was related to intra-messinian tectonics (dela pierre et al., 2007). festa et al. (2009) evidenced that also the zanclean sediments appear segmented by sub-vertical faults, nearly n-s oriented, suggesting a possible reactivation of the transpressive fault systems. in both the sectors the sedimentary succession is cut by a major n-s trending morphological scarp elongated for about 30 km and with height up to a hundred meters (fig. 2). this scarp is one of the most representative elements of the entire hilly area. several authors provided different descriptions and interpretations about the origin of this scarp. in the oldest geological literature (castiglioni b., 1934; sacco, 1917) it was referred exclusively to erosional phenomena produced by the tributaries of the tanaro river, resulting from the deepening of the main watercourse in the uppermost pleistocene and holocene (fig. 2). the middle and upper pleistocene deposits outcropping at different elevation on the two sides of the scarp have been related to the vertical displacement of a flexure structure type by forno (1982) and carraro & valpreda (1991). more recently, in the north side of sector 1 the scarp has been interpreted as a major structural discon tinuity, e.g. a deformation zone with prevalent horizontal displacement named t. traversola deformation zone (ttdz) involving the sedimentary succession of the villafranca d’asti type-area (fig. 1) (carraro et al., 1995; carraro, 1996; boano & forno, 1999; doglione, 2011). structures (lineaments and faults) of recent age (pliocene and pleistocene), n-s trending, have been also observed in the monferrato, even if they are not very common. dela pierre et al. (2003) justified the paucity of these structures considering that they are located in an area characterized by few outcrops and many faults and folds with different directions. particularly, in the trino area (north of monferrato) a n-s structure (fault or flexure) has been reported by giraudi (2014) and named salera line. northward, this line interferes with the appennine/padane thrust front and is responsible for differences between the stratigraphic succession on both sides of the line, allowing the lifting of the western area. the movement described along the salera line is connected to oblique deformations or different activity over time. southwards, this structure is testified by a strong tectonic deformation 60 gattiglio m. et al. fig. 1 schematic geologic map of the piedmont hilly region. rfdz: rio freddo deformation zone; ttdz: torrente traversola deformation zone; vv: villalvernia varzi fault; svz: sestri voltaggio zone. the dotted lines represent the sectors of the research (1 and 2) (modified from forno et al., 2015). affecting the monferrato marine succession (giraudi, 2014). in this paper we present new data, deriving from a still in progress multidisciplinary research, which is focused on the ttdz, a regional brittle deformation system evidenced by the morphological scarp (fig. 3). detailed geological surveys and multidisciplinary methodologies such as geophysical, structural, morphological, pedological and micro-paleontological analyses have been undertaken along the n-s deformation zone (fig. 2). these surveys are also aimed to highlight the possible extension of the deformation zone along the whole scarp (sector 1) and northwards up to the southern slope of the turin hill (sector 2). 2. methods in the investigated sectors detailed geological surveys and descriptions of the morphological features have been carried out. the various fracture systems and fault surfaces have been measured, also determining their direction of movement. the difficulties encountered in the field work, related also to the scarcity of outcrops, suggested to integrate the field observations with other analyses. many micro-core hand drilling, up to 2 meters deep, along the whole defor 61 the involving of the plio-pleistocene succession in the t. traversola deformation zone ... fig. 2 aster global dem (nasa-miti, dic. 2009) of the piedmont hilly region. 1) asti syncline axis; 2) ttdz: t. traversola deformation zone; 3) upper pleistocene ancient course of the tanaro river; 4) upper pleistocene ancient course of the po river; 5) upper pleistocene ancient course of the confluent po and tanaro rivers. fig. 3 overview of the scarp delimiting the poirino plateau in the background (260 m) from the asti reliefs in the foreground (240 m). mation zone were performed. these observations permitted to identify the facies of the sedimentary succession underlying an uniform cover of colluvial deposits. the gathered data allowed mapping the succession involved in the deformation at the scale 1:10,000; an example of the results is reported in the detailed map of fig. 4. furthermore an exploratory trench has been executed in the sector 2 (southern slope of the turin hill) into the moncucco torinese quarry (see fig. 5). this trench (1.5 to 3.5 meters deep and about 10 meters long), parallel to the strike of the deformation zone, evinced the brittle deformation involving the messinian deposits. from the same trench 38 samples for micropaleontological analyses have been collected. foraminiferal analyses have been carried out on sieving residues>250 m, 125-250 m and 125-63 μm, prepared following standard techniques (haynes, 1981; violanti, 2012). taxonomy is according to tjalsma (1971), kennet & srinivasan (1983) and iaccarino (1985). two different electrical resistivity surveys (ert 1 and ert 2) have been also executed, in sector 1 (villata in fig. 4) and 2 (moncucco torinese quarry in fig. 5) respectively. both surveys, approximately e-w oriented namely perpendicular to the deformation zone, are aimed to confirm the location of the structures supposed by geological field work. the geophysical acquisitions were performed by means of a syscal-r1 tomograph (iris instruments) with 48 measuring electrodes and 5 m spacing for ert 1 (total legnth of 235 m) and 72 measuring electrodes and 1 m spacing for ert 2 (total length of 71 m). a wenner-schlumberger measuring sequence was used for the two acquisitions in order to obtain both vertical and lateral resolution. acquired data were processed by the commercial inversion code res2dinv® (loke & barker, 1996). a good convergence of the results has been obtained in both the inversions with rms errors below 2 % in ert 1 and below 4 % in ert 2. 3. stratigraphic and structural features of the t. traversola deformation zone in plan view, the examined scarp, very articulated in morphological details, shows a generally rectilinear n-s trend (fig. 1 and fig. 2). this scarp sharply divides a plain area (poirino plateau with altitude between 230 and 325 m) by a hilly area essentially developed at much lower altitudes (asti reliefs with altitude between 130 and 320 m) (fig. 3). 62 fig. 4 detailed geological map of the southern stretch of sector 1 in fig. 1. the location of the geophysical cross section ert 1 near the villata village is reported. the n-s faults are connected to the ttdz. gattiglio m. et al. the deformation of the pliocene-pleistocene succession of sector 1 the pl iocene-pleistocene succession (“villafranchian” lower complex and upper complex) is well exposed in the western sector of the asti reliefs (sector 1). the geological surveys allowed to locally recognize tens of meters height differences between the succession outcropping on the two sides of the scarp (fig. 4). these differences are related to the presence of several n-s trending sub-vertical brittle structures (fig. 6) characterized by prevalent dextral strike-slip displacement. along the scarp, pervasively fractured areas, giving rise to cataclastic sediments, are observed in the surroundings of n-s trending faults (fig. 7). in these areas, mesoscopic “scaly fabric” structures (sensu vannucchi et al., 2003) (fig. 8), essentially with n-s trends, are characterized by anastomosing polished and slickenlines surfaces. the slickenlines show low dip values and s-c geometry of the polished surfaces, confirming the dextral strike-slip displacement. the presence of brittle sediment deformations confirms that the displacement not only took place along the main fault surfaces but is also distributed in numerous less important movement surfaces (“c” planes) widespread along deformation bands and confined close to the major faults (fig. 9). sediments in the deformation bands are also characterized by carbonate distributed along dense networks of cracks (fig. 10) or concentrated in concretions, both n-s trending and sub-vertically dipping, parallel to the major faults (fig. 11). reworked bodies are locally present in these bands, also affected by cataclastic deformation. decimetric thick gravelly bodies are observed, characterized by vertical dip, or centimetric fragments of silty bodies iso-oriented along the minor brittle structures. locally, gravity-induced synsedimentary deformations of sediments are also observed, associated to fractures and faults. in detail, some soft sediments deformations are observed, as slumping and de-structuring of the primary laminations, or chaotic structure connected with the overall reworking of the sediments along the main faults (boano et al., 1997). fractures and normal faults trending n50°e (serra fault, capriglio fault) and n120°e (castelnuovo fault zone, c. fagliaverde fault zone) also affect the villafranchian succession (fig. 12). near buttigliera d’asti the castelnuovo fault zone appears shifted southwards along the eastern side of the ttdz with respect to its location in the western side (fig. 12). the deformation of the messinian succession of sector 2 the ttdz probably extends northwards at the southern limb of the turin hill, where the upper messinian succession appears strongly deformed. in the moncucco torinese quarry (fig. 5) a n-s oriented trench for 63 fig. 5 detailed geological map of the sector 2 in fig. 1 including the moncucco torinese quarry. the n-s faults are probably related to the t. traversola deformation zone. the location of the geophysical cross section ert 2 and the manmade trench are also reported (modified from irace, 2004). the involving of the plio-pleistocene succession in the t. traversola deformation zone ... fig. 6 n-s oriented fracture system in the s. martino unit silt near c. quartino (ne of villata village) connected to the t. traversola deformation zone. 64 fig. 9 pervasive n-s oriented fractures in the s. martino unit silt se of valfenera village, referred to the t. traversola deformation zone. fig. 8 the s. martino unit silt often shows scaly fabric structure along the t. traversola deformation zone. the sample collected indicates a n-s dextral strike-slip fault near the valfenera village. fig. 7 the s. martino silt are locally pervasively fractured similarly to cataclastic rocks (locality near c. quartino) along the t. traversola deformation zone. fig. 10 distribution of carbonate along a dense network of mineralized fractures along the major n-s faults defining the t. traversola deformation zone (south of valfenera village). fig. 11 large carbonate concretions with vertical arrangement according to the n-s fractures trend forming the t. traversola deformation zone (south of valfenera village). gattiglio m. et al. 65 fig. 12 the main faults and deformation zones involving the stratigraphic succession of the western asti reliefs (sector 1 in fig 1). the involving of the plio-pleistocene succession in the t. traversola deformation zone ... paleontological researches was recently excavated and the two eastern overlapping walls observed (angelone et al., 2010). in detail, in the lower wall clay, sandy silt and minor gravel lenses connected to a continental environment are visible (1 in fig. 13). these sediments are cut by a concave articulated discontinuity on which a gravelly and sandy sequence inclined towards south occurs, probably forming a reworked body (2 in fig. 13). the upper wall shows sub-horizontal massive to weakly laminated sand and silt, also likely referred to the continental environment (3 in fig. 13). also these sediments are cut by an articulated discontinuity on which a set of coarse-grained sharp-sided dikes occurs (4 in fig. 13). these dikes, made up of massive gravelly -sand, deform the laminated layers in the host-rock. in the top of the upper wall an anthropic cover is present (5 in fig. 13). the sediments are dissected by faults and minor joints. a n-s striking sub-vertical transcurrent fault occurs in the lower wall. the deposits (1 in fig. 13) are locally verticalised and show an intense stratal disruption, related to the development of this fault. a reverse fault, marked by a major clayey polished and slickensided surface, also involves the sediments in the lower wall, separating the bodies 2 and 3. the sediments below the two discontinuities (bodies 1 and 3) appear lithified, suggesting a strong lithostatic load. these sediments, only deformed, are in site and referred to the messinian succession. the bodies above the discontinuities (bodies 2 and 4) are soft, suggesting a low lithostatic load. this evidence suggests a syn-sedimentary deformation younger than those affecting the underlying messinian sediments. the upper sediments (bodies 2 and 4) are probably referred to reworking phenomena involving sediments of various facies, and possibly of various ages, fillings of depressions essentially along the n-s structure. in this picture the reverse fault probably doubles the stratigraphic succession defined by messinian sediments discontinuously covered by fillings. micro-paleontological analyses confirm a sediment pattern more complex than previously reported. brackish assemblages of the upper messinian lagomare facies, with molluscs, ostracods and rare foraminifers (ammonia tepida), locally occur. most of the sediments cut by the trench yield very abundant planktonic foraminifera of older miocene intervals. assemblages of tortonian age are dominant, documented by rather common globorotalia suterae and gt. menardii form 4 of tjalsma (1971). lower messinian species, such as gt. miotumida and gt. conomiozea, seldom occur. studies are in progress to better delineate the biostratigraphical and palaeoenvironmental interpretation of the succession and verify the possible presence of pliocene deposits involved in the deformation. even if a chronological attribution is still uncertain, these soft-sediment deformations involving the messinian and perhaps pliocene succession in the sector 2 could be likely correlated to similar features recognized within the sediments of “villafranchian” lower complex (piacenzian) in sector 1. in this perspective, the structural framework recognized in the moncucco torinese area could be considered as the evidence of the northwards prolongation of the ttdz. the magnitude difference in the deformation, between the bodies below and above the two unconformities in the two walls of the trench, based on these assumptions, suggests a long-lasting tectonic activity since messinian, throughout the pliocene. 66 fig. 13 eastern wall (a) and interpretation (b) of the n-s oriented trench in the moncucco torinese quarry. the continental sediments (1 and 3) are unconformably covered by filling deposits (2 and 4) and involved by a strike-slip and a reverse fault. an anthropic cover is observed on the top (5). gattiglio m. et al. the deformation of the middle-upper pleistocene succession the silty and locally gravelly fluvial deposits related to the middle and upper pleistocene have different distribution on the poirino plateau in respect to the asti reliefs. these sediments constitute a continuous cover in the poirino plateau with a thickness between a few meters and few tens of meters. on the contrary, they form, a series of thin bodies in the asti reliefs allow on top of the ridges or infilling large meander depressions (forno, 1982; dela pierre et al., 2003). the middle and upper pleistocene sediments overall form e-w trending bodies connected to old watercourses. the petrographic and mineralogical association of fluvial sediments permit to refer these sediments to the paleo-po and paleo-tanaro rivers. these rivers in the middle pleistocene shaped two distinct bands (see 3a and 3b in fig. 17) subsequent confluent into a single collector during the upper pleistocene (see 4 in fig. 17). more recently the po and tanaro rivers have been affected by remarkable diversion river phenomena (carraro et al., 1995). their current courses, outflowing to the nw at the northern edge of the turin hill for the po river and within the asti reliefs for the tanaro river, develop in the uppermost pleistocene. 4. geophisical surveys objective of the surveys was the identification in depth of the presence of incoherent sediments, that can be associated to the ttdz, and differences in the stratigraphic sequence on the two sides of the deformation zone. the reconstructed resistivity section in the asti reliefs near villata (fig. 14, ert 1 in fig. 4 with e-w trend perpendicular to ttdz) shows sediments with 67 the involving of the plio-pleistocene succession in the t. traversola deformation zone ... fig. 14 reconstructed resistivity section along ert 1 near villata in the sector 1 along the t. traversola deformation zone as located in fig. 4. the presence of a low resistivity zone (fractured zone) is evidenced by dotted lines in the west side of the tomography fig. 15 reconstructed resistivity section along ert 2 near moncucco torinese in the sector 2 as located in fig. 5. low resistivity anomalies observed in the exploratory trench. evidence of the area interested by the excavated trench is also reported. different electric resistivity. the presence of a shallow cover (about 5-6 meters) of relatively conductive sediments (resistivities below 15 ohm.m) associable with silty-clay sediments (referred to the maretto unit) is observed in the central and eastern sectors of the section overlying a more resistive (above 400 ohm.m) formation associable with the presence of gravel and sand (referred to the gherba unit) (both units are referred in fig. 4). the western continuity of this succession is however cut by a zone characterized by lower resistivity evident between progressive 40 and 60 m (dotted lines in fig. 14). this zone likely represents a fractured zone well comparable with the map location of a fault connected to the ttdz (fig. 4). the reconstructed resistivity section in the southern slope of the turin hill near moncucco torinese (fig. 15, ert 2 in fig. 5 with trend perpendicular to the section shown in fig. 13) shows a high lateral variability in the resistivities. the more resistive anomaly of this section (200 ohm.m in the ene side of the section) is well comparable with gypsum location in the quarry. two low resistivity zones (5-15 ohm.m) probably associable to clay, silt or sand are evident in the center of the image, vertically separated by a more resistive formation (about 80 ohm.m) potentially correlated to a gravel lens. these low resistivity zones are compatible with sediments involved by n-s oriented fault systems observed in the trench realized for paleontological researches. 5. interpretation of the t. traversola deformation zone the data collected allows us to read the whole scarp separating the poirino plateau from the asti reliefs as the morphologic evidence of an important brittle structure already known in the northern stretch of the sector 1 as the ttdz (carraro, 1996). its geological significance is of complex reading due to the mutual relation between sedimentary succession and deformation development. in the present work, still in progress, this structure has been recognized up to the southern slope of the turin hill. at map scale, this deformation zone is highlighted by a n-s fault systems that cause intense fracturing of the rocks as can be inferred by geophysical cross sections. along the deformation zone the villafranchian succession is affected by horizontal displacement (fig. 16). generally, a structure with predominant horizontal displacement, involving a sub-horizontal sequence represents a tectonic element difficult to be identified. in this case, the structure may become evident only in areas where the horizontal displacement affects either dipping strata (along the limbs of the syncline in fig. 16) or sediments affected by previous faults (i.e. shifting of the castelnuovo don bosco fault in fig. 12). only in these two cases the poorly evident horizontal displacement along the fault is also responsible of more evident vertical stratigraphic differences also without vertical displacement. this structure is also responsible for the different location of the axis of the asti syncline in the poirino plateau (where the axis is shifted northward) in respect to the asti reliefs . the involving of middle and upper pleistocene fluvial deposits in the ttdz is also suggested by several evidence. for this reason, the ttdz became apparent only 68 fig. 16 not to scale pattern of the villafranchian succession shifted along the t. traversola deformation zone (ttdz). 1) villafranchian lower complex (piacenzian); 2) villafranchian upper complex (calabrian); 3) asti syncline axis during the calabrian. fig. 17 not to scale pattern of middle-upper pleistocene fluvial deposits displacement along the t. traversola deformation zone (ttdz). 1) villafranchian lower complex (piacenzian); 2) villafranchian upper complex (calabrian); 3) middle pleistocene fluvial deposits: 3a connected to the paleo-tanaro and 3b connected to the paleo-po ; 4) upper pleistocene fluvial deposits; 5) asti syncline axis during the middle -upper pleistocene. the altitude of the top of fluvial sediments is also reported. gattiglio m. et al. in the marginal areas (asti syncline limbs), while in the wide hinge area (asti syncline axis), where succession exhibits horizontal arrangement, the displacement is poorly evidenced (fig. 16). the middle pleistocene fluvial sediments related to the ancient courses of po and tanaro rivers (fig. 17) are variously located along the asti syncline limbs (southern and northern distributions of sediment relicts related to tanaro and po rivers, respectively) in both poirino plateau and asti reliefs. they appear horizontally shifted, showing height differences (of approximately 25 m) at the two sides of the ttdz, also in this case not related to a vertical shifting. the upper pleistocene fluvial sediments connected to the po and tanaro confluent rivers are located in the hinge area in the poirino plateau, where they form a wide cover (forno, 1982). on the contrary, in the asti reliefs these sediments only locally occur and are located along the northern syncline limb, where they discontinuously infill the incisions connected to the progressively deepening of the watercourse (carraro et al., 1995). the location of the river in the limb of the syncline is interpreted as responsible of its abrupt migration towards south in the asti reliefs. the different sediment distribution between the poirino plateau and the asti reliefs is therefore related to the horizontal displacement along the n-s structure, joining two distinct areas previously not adjacent. the morphological scarp is partly connected to the presence of the deformation zone and partly to the erosion of the tributaries of the tanaro river. the ttdz exhibits different deformation magnitudes in sediments of different age. the continental miocene sediments outcropping at moncucco torinese (sector 2) are strongly deformed in a relatively deep environment. instead, the fillings above the two unconformities are deformed in a relatively shallow environment. the sediments of the “villafranchian” succession lower complex, outcropping at the western edge of the asti reliefs (sector 1) also shows soft sediment deformations and faults developed at shallow environment. the distribution of the middle and upper pleistocene sediments, connected both to the progressive migration of watercourses towards the axis of the growing syncline and to the displacement along the ttdz, proves a further evolution of this structure. these observations are consistent with a long time activity of the deformation zone which was tectonically active during the deposition of the messinian and pliocene succession and continued in more recent times, as testified by the minor displacement of middle and upper pleistocene fluvial deposits. in the regional geological context the ttdz represents the shallow evidence of a deeper structure, subparallel to the rio freddo deformation zone (piana & polino, 1995), but more recently developed. the ttdz allows to kinematically separate the poirino plateau, showing a significant northwards shift, by the asti reliefs area, where the northwards shift is less important. the ttdz is not an isolated case. north of the monferrato hill the salera line exhibits similar trend and apparently similar sense of shear (giraudi, 2014). both of these structures involve the miocene and pliocene succession indicating a tertiary activity. they also probably deform the quaternary deposits indicating a prolongation of the tectonic activity in the recent time. the ttdz prolongation in the northern slope of the turin hill and its relationships with the appenninepadane thrust front are not yet known at present. because the salera line is associated to the appenninepadane thrust front we could hipotyze that also the ttdz could be connected with the development of the same frontal thrust. therefore, t. traversola deformation zone and salera line could be interpreted as part of a structural context related to north-thrusting of the piedmont hills over the po foreland basin. acknowledgment this research was conducted within the project “proactive management of geological heritage in the piemonte region” (www.progeopiemonte.it/en) cofounded by the university of turin-compagnia di san paolo bank foundation “jcapc progetti di ateneo 2011” grant on line b1 "experimental sciences and technology" (project id: orto11y7hr). we thank andrea irace for the pictures 1, 5 and 13 and the useful discussions. we are grateful to stefano gori and to an anonymous referee for reviewing the text and for the useful suggestions. references angelone c., colombero s., esu d., giuntelli p., marcolini f., pavia m., trenkwalder s., w. van den hoehe ostende l., zunino m., pavia g. (2010) moncucco torinese, a new post-evaporitic messinian fossiliferous site from piemont (nw italy). n. jb. geol. paläont. abh., 259/1, 89-104. bigi g., cosentino d., parotto m., sartori m., scandone p. (1990) structural model of italy and gravity map. cnr, progetto finalizzato geodinamica, quaderni de “la ricerca scientifica”, 114(3), 1: 500.000 scale, selca, firenze. boano p., forno m.g., giardino m. (1997) deformazioni sinsedimentarie nella successione villafranchiana presso castelnuovo don bosco (asti). il quaternario it. journ. quat. sci.,10(2), 355-358. boano p., forno m.g. (1999) la successione “villafranchiana” nell’area di castelnuovo don bosco (asti). il quaternario it. journ. quatern. sci., 12(2), 161-194. boni a., boni p., braga g.p., bruno g., casnedi r., corsi m., dal piaz g.v., gatto g.o., gatto p., motta e., perotto g., rampoldi r., mosna s. (1970) foglio 69 “asti” della carta geologica d’italia alla scala 1:100.000 iia ed. servizio geologico d’italia, roma. carraro f. (ed.) (1996) revisione del villafranchiano nell'area-tipo di villafranca d'asti. atti del convegno: "il significato del villafranchiano nella stratigrafia del plio-pleistocene" (peveragno (cn)villafranca d'asti (at), 20-24 giugno 1994). il quaternario it. journ. quat. sci., 9(1), 98-101. carraro f., collo g., forno m.g., giardino m., maraga f., perotto a., tropeano d. (1995) l’evoluzione 69 the involving of the plio-pleistocene succession in the t. traversola deformation zone ... del reticolato idrografico del piemonte centrale in relazione alla mobilità quaternaria. in: r. polino and r. sacchi (eds.), atti del convegno “rapporti alpi-appennino” e guida alle escursioni (may 31-june 1st 1995, peveragno, cn, taly), acc. naz. sc., roma, 14, 445-461. carraro f., valpreda e. (1991) the middle-upper quaternary of the asti basin. il quaternario it. journ. quatern. sci, 4(1), 151-172. carraro f., collo g., forno m.g., giardino m., maraga f., perotto a., tropeano d. (1995) l’evoluzione del reticolato idrografico del piemonte centrale in relazione alla mobilità quaternaria. in: r. polino, r. sacchi (eds.), atti conv. rapporti alpi-appennino. acc. naz. sci., sc. doc., 14, 445-461. castiglioni b. (1934) sulle cause delle deviazioni dei fiumi. zeitsch. geomorph., 8(5), 224-253. dela pierre f., piana f., fioraso g., boano p., bicchi e., forno m. g., violanti d., clari p., polino r., balestro g., d’atri a. (2003) foglio 157 “trino” della carta geologica d’italia alla scala 1: 50.000. apat, dipartimento difesa del suolo, roma. dela pierre f., festa a., irace a. (2007) interaction of tectonic, sedimentary, and diapiric processes in the origin of chaotic sediments: an example from the messinian of torino hill (tertiary piedmont basin, northwestern italy). geol. soc. amer. bull., 119, 1107-1119. doglione a. (2011) evoluzione del reticolato idrografico pleistocenico nel settore astigiano occidentale. unpublished thesis, università di torino, 99 pp. festa a., boano p., irace a., lucchesi s., forno m.g., dela pierre f., fioraso g., piana f. (2009) foglio 156 “torino est” della carta geologica d'italia alla scala 1:50.000. apat, anpa, roma. festa a., dela pierre f., irace a., piana f., fioraso g., lucchesi s.,boano p., forno m.g., bicchi e., violanti d., trenkwalder s., ossella l., bellardone g., campus s., tamberlani f. (2009) note illustrative della carta geologica d’italia alla scala 1:50.000 foglio 156 torino est. ispra, dipartimento difesa del suolo, servizio geologico d’italia. tipografia geda, nichelino, 143 pp. forno m.g. (1982) studio geologico dell'altopiano di poirino (torino). geogr. fis. dinam. quat., 5, 129-162. forno m. g., gattiglio m., comina c., barbero d., bertini a., doglione a., irace a., gianotti f., martinetto e., mottura a., sala b. (2015) stratigraphic and tectonic notes on the villafranca d’asti succession in type-area and castelnuovo don bosco sector (asti reliefs, piedmont). alpine and mediterranean quaternary, 28(1), 5-27. giraudi c. (2014) quaternary studies as a tool to validate seismic hazard potential of tectonic structures: the case of the monferrato thrust front (vercelli plain, nw italy). alpine and mediterranean quaternary, 27(1), 5-28. haynes j.r. (1981) foraminifera. john wiley and sons, new york, 433 pp. kennett j.p., srinivasan m.s. (1983) neogene planktonic foraminifera a phylogenetic atlas. hutchinson ross publishing company, stroudsburg, 265 pp. iaccarino s. (1985) mediterranean miocene and pliocene planktic foraminifera. in: plankton stratigraphy, bolli h.m., saunders j.b., perch-nielsen k. (eds.). cambridge earth science series, cambridge university press, cambridge, 283-314. irace a. (2004) il messiniano piemontese: nuovi dati da due aree campione. unpublished degree thesis, università di torino, 167 pp. loke m.h., barker r.d. (1996) rapid least-squares inversion of apparent resistivity pseudosections using a quasi-newton method, geophys. prospect., 44, 131-152. michetti a.m., giardina f., livio f., mueller k., serva l., sileo g., vittori e., devoti r., riguzzi f., carcano c., rogledi s., bonadeo l., brunamonte f., fioraso g. (2012) active compressional tactonics, quaternary capable faults, and the seismic landscape of the po plain (northern italy). annals of geophysics, 55(5), 969-1001. piana f., polino r. (1995) tertiary structural relationships between alps and apennines: the critical torino hill and monferrato area, northwestern italy. terra nova, 7, 138-143. sacco f. (1917) l’evoluzione del f. tanaro durante l’era quaternaria. at. soc. it. sci. nat., 56, 157178. tjalsma r.c. (1971) stratigraphy and foraminifera of the neogene of the eastern guadalquivir basin (southern spain). utrecht micropalentological bulletins, 4, 1-161. vannucchi p., maltman a., bettelli g., clennell b. (2003) on the nature of scaly fabric and scaly clay. journal of structural geology, 25, 673-688. violanti d. (2012) pliocene mediterranean foraminiferal biostratigraphy: a synthesis and application to the paleoenvironmental evolution of northwestern italy. in: elitok ö. (ed.). stratigraphic analysis of layered deposits, intech, rjecka, 123-160. http://cdn.intechopen.com/dfs -wm/36321.pdf 70 gattiglio m. et al. ms. received: december 23, 2014 final text received: april 10, 2015 amq abs principe et al tepro 235-238.pub available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 235 238 geology of monte amiata volcano (southern tuscany) claudia principe 1, luigina vezzoli 1,2, sonia la felice 1 1 igg cnr, istituto di geoscienze e georisorse, pisa, italy 2 dipartimento di scienza e alta tecnologia, università dell’insubria, como, italy corresponding author: c. principe <c.principe@igg.cnr.it> abstract: a multidisciplinary approach, comprising lithological, petrochemical, volcanological, structural, geometric, and morphological analyses on the monte amiata volcanic rocks and their stratigraphic relationships, has been used to reconstruct the evolutionary history of this quaternary volcano, located in the southern tuscany (italy). keywords: monte amiata, quaternary volcano, geological mapping, stratigraphy, volcano-tectonics 1. introduction in this multidisciplinary study, we describe the geological evolution of the monte amiata volcano based on stratigraphic and volcano-geological methodologies into the framework of a robust field-based work. mount amiata is a silicic quaternary volcano located in the southern tuscany (italy). after the first recognition of the volcanic nature of monte amiata made by micheli in 1733 (principe et al. 2017 cum bib), between the end of the 17th and the 19th centuries, there were numerous reports of naturalistic travels carried out in this territory and descriptions of its rocks. modern scientific studies, essentially of petrographic and geographical characters, were carried out from the twentieth century. from the 1950s to 1970s, the volcanology of monte amiata is marked by the ideas of two great names of italian volcanology: alfred rittmann and giorgio marinelli (see principe et al. 2017 cum bib). rittmann introduced the term "rheomorphic ignimbrite" to describe the extensive sheet of glassy volcanic rocks that seem to form a single body at the base of the volcanic edifice. its interpretation is that the large mass of volcanics at the base of monte amiata would be the result of the repeated emplacement of pyroclastic flows emitted by a linear fracture and in their entirety constituting a sheet of rheomorphic ignimbrite erupted from a deep laccolithic structure. marinelli essentially shared this interpretation. the authority of these two scholars made that all the following volcanological studies and geological mapping of monte amiata adopted their volcanological interpretation for the genesis of acidic lavas and the stratigraphic subdivision into three units. this tri-fold division of the volcanic activity of monte amiata includes: (1) a basal trachydacitic complex (btc), in turn divided into a lower unit and an upper unit; (2) a complex of lava domes and flows (dlc), which groups all the domes that make up the summit of the volcano and some lesser lava flows; and (3) the two, basic, lava flows of macinaie and ermeta. in this view, the major volcanological arguments debated on amiata, during the last 55 years, is the occurrence of explosive eruptions and the emplacement of pyroclastic flow deposits during its activity. in particular, the lower unit was considered, into the volcanological and petrochemical literature, as either a unique sheet of ignimbrite and rheoignimbrite deposits, or a sequence of lava flows, or, more recently, the collapse of an endogenous mega-dome. one of the features that previously restricted the distinction of geological units within the volcano was the apparent lithological uniformity that produced the distinction of only two lithological types of rocks and the consequent aggregation of all the outcrops in a few stratigraphic units. the produced review of the scientific literature on the monte amiata volcano (principe et al. 2017 cum bib) has highlighted the gaps and inaccuracies contained in the past interpretations, as well as numerous insights of investigation and discussion that have been a stimulus for the mass of stratigraphic, geological and petrochemical data collected by the research work carried out for the tuscany region project that we summarized in this contribution. actually, although the monte amiata volcano has been the subject of numerous studies, including the production of geological maps at various scales and different details, there was still not a geological model on which to base a reliable reconstruction of its geological structure and volcanological and magmatological evolution. 2. material and methods we performed a detailed field analysis and collected stratigraphic and petrographic data from outcropping deposits and from a continuous deep core drilling named david lazzaretti that was drilled on the southern flank of monte amiata by regione toscana in 2010. this deep coring intersected the entire volcano sequence, comprising volcanic units older than the outcropping rocks, and https://doi.org/10.26382/aiqua.2018.aiquaconference reached the non-volcanic substratum. the stratigraphic analysis has taken into account lithological, petrochemical, volcanological, structural, geometric and morphological characteristics of the volcanic rocks and their stratigraphic relationships. the surficial volcanic units were identified as lithostratigraphic units (more than 30 formations) and grouped into unconformity bounded stratigraphic units (ubsu) with 2 synthem and 5 subsynthem. 3. results the pre-volcanic sedimentary substratum of monte amiata volcano includes the ophiolitic unit and the santa fiora unit of the ligurian domain. the proposed geological evolution comprises two main period of activity that correspond to the older bágnore synthem and the younger monte amiata synthem. they are separated by a major unconformity corresponding to a surface of erosion, saprolithic weathering and tectonic deformation. into the bágnore synthem, there are two subsynthem. the lower, the bagnólo subsynthem, comprises several great lava flows characterized by a vitrophyric perlitic groundmass. they flowed for very long distances (up to 8 km) in all the directions (e.g. sorgente del fiora fm., marroneto fm., piancastagnaio fm., abbadia san salvatore fm., vivo d’orcia fm.). a surface of erosion and unconformity separates the bagnólo subsynthem from the overlying montearioso subsynthem. it is composed of more confined vitrophyric lava flows (e.g. tre case fm., quaranta fm., castel del piano fm.) and one exogenous lava dome and coulée (poggio pinzi fm.). all the rocks belonging to the bágnore synthem show a well-developed weathering that transformed their uppermost portion in a sandy deposit, yellow and reddish in color. the monte amiata synthem comprises three subsynthems. the lower valle gelata subsynthem is characterized by exogenous lava domes with thick coulées (e.g. poggio lombardo fm., pozzaroni fm.) and by long channelized lava flows (e.g. leccio fm., coderino fm.). the intermediate madonna degli scout subsynthem is composed of several exogenous lava domes with short coulées (e.g. poggio della pescina fm., poggio falco fm., corno di bellaria fm., la vetta fm., rifugio cantore fm.), and minor lava flows. all these units are emplaced upon a morphology that has been moulded by tectonic deformations. the final prato della contessa subsynthem comprises several exogenous lava domes (e.g. la montagnola fm., pianello fm.) and lava flows (e.g. ermeta fm., le macinaie fm., cancelle fm, fosso la cocca fm.) from the volcano summit area, and the lateral exogenous lava dome and coulée of the trauzzolo fm. the main tectonic element affecting the monte amiata area is a set of ne-sw-trending faults belonging to the bágnore and bagni san filippo trans-tensional shear zones, located to the south-west and north-east of the volcano, respectively. in addition to these faults, other three sets of lineaments has been recognized on the volcanic area and surrounding sedimentary rocks. they are the older nne-ssw trend, and the ese-wnw and sse-nnw trends that accommodate the stress produced by the ne-sw prevailing trend. all these tectonic regional trends were repeatedly active during the volcano eruptive history. the interaction of these structural elements with the stratigraphic units and the volcanic morphologies, such as domes, coulées and lava flows that compose the monte amiata edifice, hallowed to assess the presence of several volcano-tectonic graben-like structures that formed at different moments of the volcanic history. the older of these grabens corresponds to a depressed area inside the sedimentary substratum under the south-western portion of the volcanic edifice. this first collapse occurred in relationship with the emplacement of the thick succession of domes and lava flows cored by the david lazzaretti drilling. during the subsequent episodes of monte amiata volcanic activity, other grabens formed. these volcanotectonic structures repeatedly interested trachidacitic lava flows and domes, generating nested narrow structural strip on the summit portion of the volcanic edifice. from a couple of these fractures, the less evolved lavas were emitted during, and not at the end, of the volcanic history of monte amiata. the last emitted volcanics are the exogenous domes of la montagnola and poggio trauzzolo formations, unaffected by graben structures. the presence of these volcano-tectonic collapses gives reason of all the structural elements still visible on the volcano and depicts a new interpretation of the monte amiata volcano grown, that is in agreement with morpho -sructural and stratigraphic findings. petrographic analyses allowed us to distinguish five different types of lavas on the basis of textural, structural, and mineralogical characteristics. all these five lava types occur at various stratigraphic positions in all the subsynthems of montearioso, valle gelata, madonna degli scout and prato della contessa, whereas only lavas of one type are present in the bagnòlo subsynthem. all the available whole-rock chemical data of monte amiata volcanics have been reprocessed, considering the stratigraphic position of each sample, and focusing on the quantification of mixing processes between mafic and acid magmas, which were recognized in previous studies. although the chemical composition of meta-sedimentary xenoliths is poorly known, their percentages resulted to be relatively high, from 30 to 45% in lavas and from 35 to 60 % in mafic magmatic inclusions for all the five subsynthems, composing the monte amiata stratigraphy. the proportions of both the mafic end-member in acid lavas and the acid end-member in mafic magmatic inclusions were evaluated getting rid of the contribution of metasedimentary xenoliths to whole-rock chemistry. in this way, it turned out that the mafic end-member in acid lavas attains maximum values of ~15% in the bagnòlo subsynthem, ~17 % in the montearioso and valle gelata subsynthems, ~36 % in the madonna, degli scout subsynthem, and of ~46 % in the prato della contessa subsynthem. the acid end-member in mafic magmatic inclusions reaches maximum values of ~53 % in the montearioso subsynthem, ~34 % in the valle gelata subsynthem (although this figure is affected by the availability of few data), ~57 % in the madonna degli scout subsynthem, and ~64 % in the prato della contessa subsynthem. 236 principe c. et al. 237 fig. 1 schematic reconstruction of the geological evolution of the monte amiata volcano (from principe et al. 2017, pag.98). monte amiata volcano 4. discussion and conclusions the reconstructed succession is indicative of a rapid aggradation of effusive products and does not evidence pyroclastic deposits or mega-breccia facies. the previously undivided, extensive basal unit comprises different, single, superposed silicic bodies, in which we distinguish structural and morphological features typical of lava flows, such as basal and top autoclastic breccia, front ramp structures and surficial ogive structures. both at microscopic and macroscopic scale, the rock texture is not fragmental. individual flow unit does not show evidence of facies variations from proximal near vent (e.g. co-ignimbrite lithic breccia) to distal areas of deposition that is typical of pyroclastic flow deposits. in the individual flow unit, where is not vertical and/or lateral gradation in welding character from nonwelded, to medium grade (with sparse welded zones) to pervasively rheomorphic textures. individual flow units are of small volume and extension, and show channelized lobe geometry. we suggest that the extensive silicic basal (outcropping) unit of amiata volcano is a sequence of lava flows with a rapid aggradation. the stratigraphic framework reconstructed in this work, thanks to the accurate geological field survey, has made it possible to accurately define the nature of the various volcanic bodies (lava flow, lava dome, coulée), according to their lithological and outcrop characteristics, and to place them in their proper position within the geologic evolution of the volcano. as a whole, the volcanic deposits of monte amiata exclusively consisting of a series of acid lava flows, exogenous domes and associated coulées. large volumes of lava blocks, dispersed at the periphery of the volcano, and interpreted in the past as blocky lavas, are related to pervasive surface alterations of pressure ridges on top of the major lava flows and to collapse landslides occurred at the margin of the volcanic body in contact with the shaly deposits of the sedimentary substratum. despite the apparent homogeneity of mineralogical and chemical composition of monte amiata volcanics, invoked in the previous literature as an obstacle to a clear geological and volcanological interpretation of the volcano, we have shown that each identified and mapped stratigraphic unit has petrographic peculiarities that allow its differentiation and recognition, as well as a set of distinguishable lithological and depositional characters. based on the petrochemical data, the preliminary volcanological framework for the bagnólo subsynthem consists of a magma chamber, initially containing a relatively large mass of acid magma, in which a relatively small fraction of mafic magma entered afterwards. during the subsequent periods of volcanic activity, the acid magma batches stationing below the volcano became progressively smaller and the mafic magma venue became consequently more important, originating the abundant mafic magmatic inclusions found in the volcanic deposits. structures and textures of the volcanic deposits suggest the occurrence of complex mingling and mixing processes during volcanic activity. in particular, the mafic magmatic inclusions abundantly present in the volcanic rocks, especially in the most recent units of the stratigraphic sequence, are characterized by the presence of megacrysts in chemical disequilibrium, that are also consistent with the occurrence of mingling processes. acknowledgements this work derives from a research project on the monte amiata volcano funded by the regione toscana, sistema informativo territoriale ed ambientale branch. references marinelli g. (1961)genersi e classificazione delle vulcaniti recenti toscane. atti soc. tosc. sc. nat., serie a, lxviii, pisa. micheli p. a. (1733) manoscritto citato in lotti b. (1932) appunti fisiografici sul monte amiata. memorie soc. geol., it. 1-8. principe c., lavorini g., vezzoli m.l. (eds) (2017) il vulcano di monte amiata. eds nola, pp.400, isbn 978-88-99742-32-4, pp.399. rittmann a. (1958) cenni sulle colate di ignimbriti. boll. acc. gioenia sc. nat. serie iv, 10, catania. 238 principe c. et al. ms. received: may 3, 2018 final text received: may 21, 2018 base palaeohydrography and early settlements in padua (italy) paolo mozzi1, silvia piovan1, sandro rossato1, maurizio cucato2, tiziano abbà2, alessandro fontana1 1 dipartimento di geografia, università di padova, padova 2 geologist, free-lancer corresponding author: p. mozzi <paolo.mozzi@unipd.it> abstract: mozzi p. et al., palaeohydrography and early settlements in padua (italy). (it issn 0394-3356) this paper concerns the palaeohydrographic and geomorphological evolution of the alluvial plain around padua during the last millennia, and the relative implications for the development of early settlements in the present urban area. the first archaeological evidences in padua date to the late bronze age (1400–1000 bc). since the early iron age (9th century bc) the settlement experienced a progressive expansion and in the 6th century bc it was already an important urban centre. in the 2nd century bc padua became a roman municipium, being one of the most important cities in ne italy. latin historians wrote that it was crossed by a large river, called the meduacus, which was identified with the brenta river in previous archaeological studies. the brenta river is an important alpine river that now flows about 5 km ne of padua. since the middle ages the bacchiglione river, a minor course partly fed by ground-water, has been flowing within the city centre along two characteristic meanders; it was artificially diverted only in the first half of the 20th century in order to protect the city from floodings. as the recent urban expansion limits the possibility to investigate the urban area with remote sensing and field survey, the investigation focuses on the alluvial plain at the western outskirts of padua. a 70 km2 area was analysed through the integrated use of vertical and oblique aerial photographs, satellite images, digital terrain models (dtm), field survey and corings. the most ancient holocene channel belt recognized in the study area is the mestrino-rubano (mr) one, which incised the alluvial plain formed during the late glacial maximum (lgm). it was formed by the brenta river between the lateglacial and 6300 cal bp. a palaeochannel named "la storta" was recognized for a stretch of 13 km; it probably was the last active river bed in the mr channel belt, between 8400 and 6300 cal bp. the present bacchiglione river follows another, more recent brenta river channel belt, named veggiano-selvazzano (vs) channel belt. the meanders in the city centre of padua most probably belong to this channel belt. chronostratigraphic data indicate that the vs channel belt was active in the 2nd millennium bc. this implies that padua was probably crossed by the brenta river during the bronze age. a single radiocarbon dating suggests that the vs brenta river was active also during the 2nd–5th century ad. such indication brings about the possibility that the brenta river may have been flowing through the city also during the iron age and in roman times, and that the bacchiglione river established its present course in early medieval times. this hypothesis has important implications for the reconstruction of the topography of ancient padua, but it is based on a weak chronostratigraphy, which should be better investigated in the future. it contradicts geoarchaeological observations, which indicate no evidences of the sedimentary activity of such a large river in the city centre later than the end of the 2nd millennium bc. moreover, previous geomorphological investigations show that the brenta river was following the present direction since the beginning of the 1st millennium bc, which means that in the iron age and in roman times the river would flow several kilometres east of the city. riassunto: mozzi p. et al., paleoidrografia e insediamenti antichi a padova (italia). (it issn 0394-3356) nella pianura veneta il popolamento umano è stato molto intenso a partire dall'olocene medio e l’evoluzione geomorfologica ha spesso condizionato le modalità insediative. in questo studio si tenta di definire l’assetto paleoidrografico relativo ai primi insediamenti e allo sviluppo urbano antico della città di padova. la recente espansione edilizia limita fortemente la possibilità di attuare tecniche di telerilevamento e di rilevamento di campagna. le ricerche si sono quindi concentrate alla periferia occidentale di padova e nei territori contermini, analizzando i tratti di pianura attivi durante l'olocene medio e superiore. le prime tracce di frequentazione a padova si riferiscono all’età del bronzo recente-finale (xiv-x secolo a.c.). dalla prima età del ferro (ix secolo a.c.) padova fu sede di un importante insediamento, che divenne compiutamente urbano attorno al vi secolo a.c. in epoca romana padova era uno dei maggiori centri dell'italia nord-orientale; nel ii secolo a.c. assunse il titolo di municipium. la città romana era attraversata da un ampio corso d’acqua denominato meduacus dagli autori latini; negli studi archeologici questo fiume è associato al brenta, che attualmente scorre alcuni chilometri a oriente della città (fig.1). fin dal medioevo padova è stata attraversata dal fiume bacchiglione, un corso d’acqua minore alimentato in parte da risorgive, che fu deviato artificialmente al di fuori del centro nella prima metà del xx secolo per limitare il rischio di inondazioni. il bacchiglione nel centro della città segue due ampi meandri, con ogni evidenza ereditati da un precedente percorso del brenta. tramite l'uso combinato di fotografie aeree zenitali e oblique, immagini satellitari, modelli digitali del terreno (dtm), rilevamento sul terreno e carotaggi stratigrafici si è analizzata un'area di 70 km2 situata a ovest del centro storico (fig. 2). nella ricerca sono stati effettuati 17 nuovi carotaggi con una sonda manuale fino ad una profondità di 8,5 m lungo transetti che hanno consentito di ricostruire sezioni stratigrafiche e raccogliere campioni poi datati con il radiocarbonio (figg. 3, 4, 5, 6, 8). questi dati, assieme alle indagini stratigrafiche effettuate nel 1992 in una cava presso santa maria di veggiano (fig. 7), a un nuovo carotaggio meccanico e ad altre informazioni geognostiche precedenti, hanno permesso di ricostruire l'assetto sedimentario del sottosuolo. per definire la cronologia delle diverse direttrici fluviali sono state utilizzate datazioni al radiocarbonio su sedimenti organici e legni, oltre che il materiale archeologico eventualmente inglobato nei sedimenti. nell’area di studio sono state riconosciute due fasce di canali di età olocenica, attribuibili al fiume brenta sulla base delle dimensioni dei paleoalvei, della geometria dei corpi sedimentari e della composizione petrografica delle ghiaie (fig. 2). nei settori di pianura interposti fra le direttrici oloceniche affiorano i sedimenti alluvionali lgm e la superficie è caratterizzata da suoli con orizzonti calcici ben sviluppati, come già documentato in tutta la pianura veneto-friulana. la fascia di canali più antica, chiamata mestrino-rubano (mr), è incisa nei depositi del lgm e ha un’età compresa tra il tardoglaciale e 6300 cal bp; ha una larghezza media di alcuni chilometri e segue un andamento circa wnw-ese. all’interno di questa fascia di canali è presente un paleoalveo particolarmente ben conservato, che si segue con continuità per oltre 13 km, noto come il paleoalveo de "la storta": è probabile che questo sia l’ultimo percorso lungo questa direttrice, attivo tra 8400 e 6300 cal bp. l’altra fascia di canali è attualmente seguita dal fiume bacchiglione ed è in parte mascherata dai sedimenti di quest’ultimo corso d’acqua. si tratta della cosiddetta fascia di canali di veggiano-selvazzano (vs), che era attiva nel ii millennio a.c. una singola datazione su il quaternario italian journal of quaternary sciences 23(2bis), 2010 volume speciale 387-400 388 p. mozzi et al. 1. introduction the geoarchaeological investigation of alluvial environments has received increasing attention in the last two decades (kidder, 1996; brown, 1997; 2008; beach & luzzadder-beach, 2008). in fact, the majority of alluvial plains in the world have been inhabited since early prehistory and important ancient civilizations were rooted in floodplains. the reasons for this are obviously related to the large availability of natural resources for basic human needs, such as drinking water, hunting and fishing grounds, wild crops, pastures and fertile land which, even in dry regions, can be easily irrigated. most important for the development of complex societies has been the role of rivers as local, regional and super-regional commercial routes. alluvial plains are not only attracting areas for human activities, but, in a geomorphic perspective, they are also characterized by the prevalence of depositional processes vs. erosional ones. the archaeological record is often preserved within alluvial sedimentary sequences, which also contain palaeoenvironmental proxies, such as pollens, seeds, wood, microfossils and faunal remains. the interfingering between archaeological and sedimentary archives provides high potentialities for understanding how human activities have been interacting with the dynamics of the natural environment, in terms of both opportunistic use of resources and mitigation of environmental constraints. living in alluvial plains may as well be problematic. riverine settlements are subject to overbank flooding, levee breaches, and banks instability related to lateral channel migration. surface water stagnation may severely limit agriculture and foster diseases such as malaria and cholera. when and where societal organization allowed it, huge efforts were carried out for the protection of settlements and fields from floods and for draining water-logged soils. the impact of these actions on the landscape is comparable to that associated with the opposite strive for irrigating dry lands on river terraces and interfluves. the network of dykes, canals and ditches built for water management “in the vast majority of, if not all, contemporary floodplains” makes them “in part artifacts and as such indicators of the impact of humans on the environment” (brown, 1997, p.1). the venetian plain was inhabited since prehistory. focusing just on postglacial cultures, the transition from the mesolithic to neolithic, chalcolithic and the bronze age is well documented (aspes, 1984). already in the iron age, several settlements in lowland veneto became urban centres (chieco bianchi & tombolani, 1988), which were progressively subject to roman influence since the 3rd century bc and later became incorporated in the roman empire. in the 1st century bc the roman geographer strabo describing the area populated by the venetian people wrote that "some of their cities stand in the midst of water like islands, others are only partially surrounded. such as lie above the marshes in the interior are situated on rivers navigable for a surprising distance" (geographia, v, 1, 5), evidencing the strong relationships existing between surface water and settlements. the origins of padua as a major settlement trace back to the early iron age (de min et al., 2005), with some evidence of bronze age frequentation. it is a fluvial city, presently crossed by the small bacchiglione river but only few kilometres away from a larger river of alpine origin, the brenta river, which has been fundamental for the upbuilding of the alluvial plain (fig. 1). any understanding of the role played by the environment in the foundation and development of the city must rely on the recognition of the palaeohydrographic setting and its evolution. since early investigations, it was evident that the topography of the pre-roman and roman city was moulded by the geometry of the two large meanders which cross it (gloria, 1876; gasparotto, 1951; bosio, 1981a, b). recent geoarchaeological studies have addressed the problem of reconstructing the ancient hydrography in the city centre, mainly through geoarchaeological observations (balista & rinaldi, 2005). though providing interesting and relevant data, the spot nature of these investigations, carried out in a limited number of rescue archaeological excavations, limits palaeohydrographic reconstruction. moreover, the growing of the city since protohistory to medieval and modern times has largely masked and cancelled the original fluvial landforms (ferrarese et al., 2006), and the present urban setting hinders the execution of corings and digging of pits for the analysis of the fluvial sedimentary record. in order to overcome these problems, this investigation focuses on the alluvial plain that extends at the western outskirts of padua, where agricultural areas allow for more effective geomorphological and geological surveys. the new data presented here provide evidence on the holocene evolution of the fluvial network upstream of the city and help in detecting the relations between rivers and early settlements. un frammento di ramo a santa maria di veggiano indica la possibilità che la deposizione delle ghiaie all'interno dell'alveo sia avvenuta anche tra il ii-v secolo d.c. si dimostra dunque che il brenta scorreva lungo la direttrice mr nell'olocene iniziale e medio; invece la fascia di paleoalvei vs, formata anche essa dal brenta, era attiva nell'olocene finale e giungeva fino al centro della città anche durante l'età del bronzo; probabilmente fu questa direttrice a formare i meandri che tutt'oggi caratterizzano il centro di padova. l'eventuale passaggio del brenta per il centro cittadino nel ii-v secolo d.c. è suggerito dall’attivazione dell’alveo ghiaioso a santa maria di veggiano, ma questa indicazione si basa su un’unica datazione al radiocarbonio ed è, pertanto, piuttosto debole e controversa. infatti, l’ipotesi di un corso del brenta per padova nell’età del ferro e in periodo romano non pare supportata dai dati geoarcheologici, che testimoniano una attività di sedimentazione fluviale in città piuttosto limitata, incompatibile con la dinamica di un fiume alpino. inoltre, le ricerche geomorfologiche condotte precedentemente poco a nord e a est di padova sembrano indicare che il brenta scorreva lungo la sua attuale direzione già dall’inizio del i millennio a.c. keywords: palaeohydrography, channel belt, geoarchaeology, alluvial plain, venetian plain. parole chiave: paleoidrografia, fascia di canali, geoarcheologia, pianura alluvionale, pianura veneta. 2. geomorphological setting 2.1. the brenta river alluvial system padua lies in the distal sector of the alluvial system of the brenta river. this river has a large mountain catchment, which extends for about 1800 km2 in the eastern southern alps and comprises part of the dolomites. average water discharge is about 70 m3/s at the exit of the mountain catchment at bassano del grappa. the river presently flows some kilometres east of padua and debouches in the adriatic sea. in the last 20 ka several geomorphic changes occurred in the brenta sedimentary system, mainly in response to changing climatic and environmental conditions (mozzi, 2005; fontana et al., 2008). a major aggradation phase took place during the last glacial maximum (lgm), when the sedimentary discharge supplied by the glacier hosted in the brenta alpine valley brought to the formation of an alluvial megafan in the plain; the brenta megafan lies between the sile river to the east and the astico river to the west, and extends to the present coastal area of venice (mozzi, 2005). in the apical sector, from the piedmont down to the spring belt, the lgm deposits consist of tens of meters of thick amalgamated gravels. in its distal portion, the lgm alluvial sequence is formed by 15–20 m of finedominated deposits, with the intercalation of sandy channel bodies that generally have a thickness of 1–2 m (bondesan et al., 2008); in the centre of padua medium sands are the coarsest lgm sediments (iliceto 389palaeohydrography and early settlements in padua (italy) ... et al., 2001). at the end of lgm, around 17,500 cal bp, fanhead incision started in the brenta megafan in response to glacial decay (mozzi, 2005). this erosive tendency was common to the other megafans of the venetianfriulian plain, namely tagliamento and piave megafans, which developed important fluvial incisions between the end of lgm and early holocene (fontana, 2006; fontana et al ., 2008, in press; carton et al ., 2009). aggradation occurred in these incisions during middle and late holocene, leading them to fill-up almost totally and obscuring their topographic evidence. soil formation took place in the interfluves between the incised valleys; the typical calcic soil that developed on finegrained parent material in the distal reaches of the lgm megafan, known as “caranto”, is a stratigraphic marker of the pleistocene–holocene boundary, which can be traced throughout the venetian-friulian plain (mozzi et al., 2003; fontana et al., 2008). in the apical portion of the brenta megafan, postglacial river downcutting resulted in the formation of 20 m high fluvial scarps. these scarps disappear about 10 km upstream of padua, where the incisions are completely filled by holocene deposits. in the centre of padua (cappella degli scrovegni, see fig. 2 for location), the sedimentary fill of the incised valley consists of a ca. 9 m thick, fining upward sequence, cut in lgm deposits (iliceto et al., 2001). this valley fill shows a transition from coarse-grained sand with common 1–3 cm pebbles to medium-grained sands and sandy silt; a soil fig. 1 study area location map (geomorphology outside of the study area after castiglioni, 1982a; castiglioni et al., 1987; murst, 1997; ferrarese et al., 2006; bondesan et al., 2010). inquadramento dell’area di studio (elementi geomorfologici fuori dall’area di studio da castiglioni, 1982a; castiglioni et al., 1987; murst, 1997; ferrarese et al., 2006; bondesan et al., 2010). 390 with a fairly well developed calcic b horizon closes the sequence. at the surface, abandoned brenta meandering channels have been recognized using aerial photographs in the alluvial plain west of padua. they are likely to continue in the urban area (castiglioni, 1982a, b; baggio et al., 1992; balista, 2004; balista & rinaldi, 2005), where they are masked by buildings, roads and other infrastructures. radiocarbon datings carried out on the infilling of some abandoned channels nw of padua indicate an early to middle holocene deactivation (castiglioni et al., 1987). one of these palaeochannels, known as “la storta” palaoechannel (castiglioni, 1982a, b; castiglioni et al., 1987), was been mapped using remote sensing, high resolution dtms and 19th century topographic maps for a distance of more than 10 km (ferrarese et al., 2006). in the alluvial plain south of padua, several alluvial ridges are present with a nw–se direction, indicating vertical aggradation of the alluvial plain (favero, 1994, bondesan et al., 2010; murst, 1997). the geology of the plain portion that falls within 1:50,000 map 147 monselice has been recently surveyed as part of carg geological cartography of italy (cucato & sedea, in press). the survey indicates that middle holocene aggradation of brenta alluvial deposits occurred on top of the pedogenized lgm alluvial surface, on the interfluve that bounds to the south the post-glacial incision of padua. the caranto palaeosoil at the top of the lgm sequence is usually well preserved at depth of 1 4 m from surface. radiocarbon datings point to a time of deposition of this unit approximately comprised between 6500 and 4500 cal bp. radiocarbon datings of tree trunks embedded in gravelly channel deposits upstream of piazzola sul brenta indicate that in the 1st millenium bc the brenta river was flowing along the same direction as present (pellegrini et al., 1984). the brenta river now follows an approximately nw–se direction until ponte di brenta, ca. 5 km ne of padua (fig. 1). downstream of ponte di brenta, the river formed several alluvial ridges which slope se, with ages comprised between the beginning of the 1st millennium bc and the middle ages (castiglioni et al., 1987; mozzi et al., 2004; bondesan et al. 2008). 2.2. the bacchiglione river alluvial system the bacchiglione river has been flowing through padua since the middle ages; only in the 20th century it was artificially diverted out of the city in order to prevent floodings. in the 1950s, long tracts of the river in the centre of padua were filled and covered by roads. the bacchiglione river about 15 km upstream of padua has an average discharge of 27 m3/s (mozzi, 2008); about one third of the discharge is supplied by groundwater-fed springs located in the plain about 30 km ne of padua. these springs are fed by the groundwater table which crops out along the so-called spring belt; this latter has a width of 5-10 km and marks, almost continuously, the transition between the gravelly permeable piedmont plain and the clayey-siltysandy impermeable lower plain. the main tributary of the bacchiglione river is the astico river, which has a mountain catchment of 623 km2 in the venetian prealps; the junction is located about 25 km upstream of padua (the last reach of the astico river before the junction is called tesina river) (fig. 1). due to its relatively low discharge and sedimentary load, the geomorphic activity of the bacchiglione river has been much lower than the brenta river (castiglioni, 1992). the alluvial plain of the bacchiglione fig. 2 geomorphological sketch of the study area with the location of cross sections, boreholes and sites mentioned in the text. schema geomorfologico dell’area di studio con l’ubicazione delle sezioni, dei sondaggi e dei siti citati nel testo. p. mozzi et al. 391 river near padua consists of a narrow belt, with an average width of less than 1 km (arpav, 2005; ninfo, 2003; mozzi, 2008). at trambacche, about 9 km upstream of padua (fig. 2), sediments attributed to the bacchiglione river were cored in 2 boreholes to the depth of 8 m from surface (bianchin citton, 1993). the lowest unit (8.0–3.5 m from surface, base unknown) consists of two main sequences where sandy channel bars are covered by a residual channel fill (lower sequence) and natural levees (upper sequence). early to middle bronze age archaeological levels embedded in the alluvial sediments indicate that the upper sequence. formed in the second half of the 2nd millennium bc. above lies a fine-grained overbank unit with hydromorphic soils which evidence a period of low aggradation (3.5–2.5 m from surface); the intercalation of anthropic deposits comprised between the final bronze age, the iron age and roman age points to a time of deposition which encompasses the 1st millennium bc. the top unit (2.5 m to surface) consists of a set of silty residual channel fill and sandy-silty crevasse deposits; pottery shards within the deposits indicate medieval to renaissance ages. downstream of padua, the bacchiglione river is confined in a pre-existing depression related to the upbuilding of brenta river alluvial ridges (castiglioni, 1992; arpav, 2005). to be noted that the two meanders of the bacchiglione river in the centre of padua are much larger that those present upstream and downstream of the city. basing on morphometric analysis they have been interpreted as belonging to a former holocene brenta river, later occupied and only slightly modified by the bacchiglione river (castiglioni, 1982a, b; castiglioni et al., 1987). the thick body of coarseto medium-grained sands, with lenses of fine gravels which is present on the northern bank of the western meander at cappella degli scrovegni (iliceto et al., 2001) (fig. 2), is consistent with the sedimentary activity of the brenta river and supports this interpretation. the hypothesis that the brenta river was still flowing through padua during roman times was proposed by archaeologists on the basis of findings of large roman bridges and docks along the river banks and from the interpretation of writings by titus livius (livy) and pliny the elder, who called this river the meduacus (gasparotto, 1951; bosio 1981a, b). recent geoarchaeological investigations carried out in the city centre propose that the main course of the brenta river may have been flowing through padua until the end of the bronze age, but probably not later than the 10th–9th century bc (balista & rinaldi, 2005). 3. archaeological setting the oldest traces of ancient settlements in the alluvial plain west of padua date back to the ancient neolithic (cupitò, 2006). surface scatters of neolithic flint artifacts and bronze age pottery were found few kilometres south of trambacche (monticello area, bianchin citton, 1993) and near via po (cupitò, 2006) (fig. 2). some scattered findings dating between neolithic and the bronze age were collected north of "la storta" palaeochannel, but not associated with important archaeological structures (leonardi, 1993). an early to middle bronze age settlement, with some evidence of pile-dwellings, was found at trambacche with corings and the observation of stratigraphic sections on the present bacchiglione river bed and banks (bianchin citton, 1993); the reconstructed palaeoenvironmental setting suggests that the site was in a humid area near an abandoned meander of the bacchiglione river, at the bottom of a slightly incised valley now filled by sediments. during the late bronze age (1400–1000 bc) human groups inhabitated the area of the city of padua, but traces are poor, mainly sealed by more recent anthropic aggradation (leonardi, 1990; de vanna et al., 1995; groppo, 2005; pirazzini, 2005a, b). padua experienced a major growing phase during the iron age, starting from the 9th century bc; by the 6th century bc it was already a large urban settlement (fogolari & chieco bianchi, 1981; de min et al., 2005). the city developed along the banks of the opposing bends of the meanders that mark the geomorphology of the city centre. since the 2nd century bc padua became a roman municipium named patavium, connected to the main cities of atria (adria), altinum (altino), concordia and aquileia by an important consular road, the via annia (bassani, 2010). after a period of crisis in early medieval times, the city flourished again in the 12th century ad, with important changes in the urban structure; large sectors of the present city still date to the 12th–15th century ad (bonetto, 2009). the stacked layering of different cultural periods resulted in a very complex urban archaeological stratigraphy, with a maximum thickness of 7 m (de min et al., 2005); it also produced an archaeological mound in the core of the city center, along the two meanders, which is up to 5–6 m higher than the surrounding alluvial plain and covers an area of about 1.5 km2 (ferrarese et al., 2006). 4. materials and methods a dtm based on 1 m contour lines derived from regional topographic maps at scale 1:5,000 was used to identify and map the main landforms in the whole study area; a lidar dtm was also processed on a smaller sector centred on padua. satellite images have been processed and analyzed for the detection of the palaeohydrography, as well as different sets of vertical aerial photographs at scales 1:17,000 to 1:33,000 and ortophotos with 1 m resolution. oblique photos, acquired during low-altitude flights, were also used and proved to be very useful in this context (mozzi & ninfo, 2009; mozzi et al., 2010). the map of lgm deposits and of the holocene channel belts in fig. 2 is based on specific field surveys with shallow hand augerings, and geomorphological analysis of the lidar dtm, high resolution satellite images and aerial photographs. the geological units in the urban area of padua have been determined using about 400 unpublished mechanical corings stored in geotechnical archives. during field survey, boreholes were carried out with a hand-auger (edelman combination-type, ejikelkamptm), which allowed the extraction of semi disturbed sediment samples down to a maximum depth of 8.5 m. peats and organic clay and silt were sampled palaeohydrography and early settlements in padua (italy) ... 392 with a cylinder sampler, which prevented contamination; samples for radiocarbon dating were collected from the inner part of the cores. five sections in sand pits in santa maria di veggiano (in this paper: sm veggiano) were described and sampled by g.b. castiglioni and one of the authors (m. cucato) in 1992. these unpublished data were included in the data set, adding to the information obtained from 17 boreholes drilled during the present research. a 20 m deep mechanical coring drilled for geotechnical purposes in selvazzano dentro was also described. these stratigraphic data were supplemented by isolated cores and cross-sections previously examined by castiglioni et al. (1987), in order to extend the data set near rubano (rubano cross-section) and in the nw outskirts of padua (via caporello section, and via po borehole), where urbanization no longer allows field survey. original field notes provided by g.b. castiglioni were used to update the stratigraphic logs. wood and carbonaceous samples were stored in aluminium foil and later dried in oven at 60 °c. conventional radiocarbon ages were obtained on selected samples of organic sediment or wood remains. radiocarbon samples were selected in order to represent the period of channel activity, following recommendations of berendsen & stouthamer (2000). the samples collected in ca’ baggio section were radiocarbon dated at the ångstrom laboratory (uppsala, sweden), whereas those from sm veggiano were analyzed by krueger enterprises inc. (geochron laboratories division, cambridge – massachusetts, usa). radiocarbon ages, including those from castiglioni et al. (1987), were calibrated using calib 6.0 online application (stuiver & reimer, 1993; stuiver et al., 2010) and calibration curve intcal09 (reimer et al., 2009). the available radiocarbon datings and calibrations (2-sigma ranges) are presented in table 1. 5. stratigraphic data 5.1. ca’ baggio and rondinelle cross-sections thirteen hand augerings organized in two perpendicular cross sections (ca’ baggio and rondinelle) have been drilled across the abandoned river bed of the brenta river known as “la storta” palaeochannel, about 2 km sw of the town of rubano (fig. 2). two architectural arrangements are present in the ca’ baggio (cb) cross section (fig. 3a): at the southern end, a sand body is covered by an alternation of silty sand and silt, about 1.5 m thick, intercalated with a 50 cm thick organic layer in the core cb05. this sequence is capped by a calcic horizon observed in cb04 and cb05 corings. in the northern part of the section, a channel sand body, at least 5 m thick, cuts the sequence of finer sediment and the organic layer. the whole sequence is closed by fine-grained sediments (clay, silt and silty-clay). the organic layer sampled at 360 cm depth in cb05 gave an age of 8412-8193 cal bp. the rondinelle (ro) cross section is located perpendicular to the one of ca’ baggio, linking to each other at cb03 borehole. between ro01 and ro03 it shows a fining-upward sand to clay sequence with a calcic horizon at the top (fig. 3b). three sand bodies, interpreted as channel deposits, cut into this sequence. the largest sand body (centred at borehole cb03 and common to the two cross sections), is interpreted as being the channel deposits of la storta palaeochannel, active after 8412–8193 cal bp. the other two minor sand bodies are probably relative to crevasse channels. 5.2. via caporello cross section this cross section cuts la storta palaeochannel in the nw outskirts of padova in via caporello street; it consists of 4 boreholes (fig. 4). a sand body thicker tab. 1 radiocarbon datings mentioned in the text. datazioni al radiocarbonio citate nel testo. p. mozzi et al. than 6 m is present in capor2 core. an organic layer that lies on top of this sand body is interpreted as the residual channel fill after deactivation. two samples of organic sediment were radiocarbon dated by castiglioni et al. (1987), providing ages of 6568–6297 cal bp and 6213–5745 cal bp respectively at the bottom and at the top of the layer. chronostratigraphy thus suggests that the deactivation of la storta palaeochannel took place not long before 6568–6297 cal bp. 5.3. po1 borehole po1 core was drilled in an abandoned meander of the brenta river near la storta palaeochannel, in via po street in the northern outskirts of padua (fig. 5). it shows a 2.5 m thick sand body covered by about 6 m of finegrained sediments (silty clay and silt). three radiocarbon dates were carried out by castiglioni et al. (1987): two wood remains embedded in silty clay at the depth of 470 cm gave ages of 6212–5437 cal bp and 6910–5990 cal bp; a sample of peaty clay at 263 cm depth gave an age of 5797–4828 cal bp. the buried sand deposits are interpreted as channel bars, covered by the mud infilling following deactivation: this suggests that the meander was abandoned before 7000– 6000 cal bp. 5.4. rubano cross section the rubano cross section cuts an abandoned brenta meander which is about 1.5 km n of la storta palaeochannel (fig. 6). the cross section shows a 4–7 m thick sand body, which is partly covered by 2.5 m of fine-grained sediments (clay and silty clay) interlayered 393 fig. 3 ca’ baggio (a) and rondinelle (b) cross sections and location map (c). sezioni stratigrafiche di ca’ baggio (a) e rondinelle (b) e loro ubicazione (c). palaeohydrography and early settlements in padua (italy) ... with two peat layers in the basal part. the radiocarbon dating of a peat sample at 240–270 cm depth gave an age of 12,405–11,306 cal bp (castiglioni et al., 1987). other two radiocarbon datings from peaty clay samples below the sand body, at depths of 800–794 and 940–946 cm, gave the ages of 23,351–19,889 and 23,546–22,304 cal bp respectively. the sand body is interpreted as deriving from channel bar deposition of a meander cut in lgm alluvium. the radiocarbon dating at the base of the top muddy deposit indicates a lateglacial deactivation of this river channel, which is thus much older than la storta palaeochannel. 5.5. sm veggiano cross section sm veggiano cross section runs across the welldefined, approximately n-s depression presently followed by the tesina padovano river, a small river fed by groundwater and local surface runoff (fig. 7). the stratigraphic data derive from 4 stratigraphic sections observed along the walls of sand and gravel pits (sec. 1–4) and 17 manual boreholes. four different stratigraphic units were recognized. the lowest one consists of alternances of silt, clay and fine-grained sands in 30–50 cm thick layers, with the intercalation of peat layers. a radiocarbon dating carried out on peat at 500–515 cm depth in section 2 provided an age of 23,558–22,311 cal bp. this lgm age estimate is coherent with the sedimentary facies, which are typical of the glaciofluvial deposits of the distal brenta megafan (mozzi, 2005; miola et al., 2007; bondesan et al., 2008). a well developed soil is present at the surface of this unit, which has calcic horizons with carbonate concretions up to 20%, often overlain by a leached horizon depleted in carbonate content. these pedofeatures allow to correlate this soil with the “caranto” paleosol which marks the top of the lgm sequence in the distal brenta megafan in the entire venetian area (gatto & previatello, 1974; mozzi et al., 2003; arpav, 2005) as well as in the other megafans of the venetian-friulian plain (fontana et al., 2008). a rather homogeneous sedimentary unit, consisting of medium to coarse sands and gravels with evident cross-bedding, is cut in the lgm deposits. pebbles mainly consist of carbonate rocks, metamorphic rocks, quartz (mainly metamorphic), volcanic 394 fig. 4 – via caporello cross sections (a) and location map (b) (modified from castiglioni et al., 1987). profilo stratigrafico di via caporello (a) e sua ubicazione (b) (modificato da castiglioni et al., 1987). p. mozzi et al. 395 fig. 5 stratigraphic log of po1 borehole in via po street in padua (a) and location map (b) (modified from castiglioni et al., 1987). log stratigrafico del sondaggio po1 di via po a padova (a) e sua ubicazione (b) (modificato da castiglioni et al., 1987). fig. 6 rubano cross section (a) and location map (b) (modified from castiglioni et al., 1987). profilo stratigrafico di rubano (a) e sua ubicazione (b) (modificato da castiglioni et al., 1987). palaeohydrography and early settlements in padua (italy) ... rocks, intrusive rocks and flint, from the most to less abundant respectively. the sediments are interpreted as the amalgamation of channel bars of the brenta river. this unit is at least 4 m thick, but the lower boundary has been reached only in few boreholes and pits. several tree trunks, whose diameters range from 30 to 45 cm, were observed in the pits; various centimetric limb fragments and wood chips were also found. radiocarbon dating of wood fragments located between 80 cm and 130 cm above the unit lower boundary in section 3, gave an age of 5898-5258 cal bp. other radiocarbon datings, carried out on wood fragments in section 1, about 40 cm under the unit upper boundary, gave ages of 4440–4077 and 4090–3437 cal bp respectively. at the top of the layer (10–25 cm from the upper boundary) the radiocarbon dating of a limb fragment embedded in sandy gravel gave an age of 1897–1541 cal bp. some pottery shards, attributed to the early bronze age (indicatively 2200–1800 bc: g. leonardi, personal communication) were found inside these deposits, between 200 and 370 cm from the lower boundary, sometimes imbricated. they show evidence of rounded edges due to fluvial abrasion. an organic-rich silt and clay unit, up to 3 m thick, was recognized in sections 2 and 4. it is interpreted as the residual channel fill after deactivation. a radiocarbon dating from wood fragments, placed 40 cm above the lower boundary, gave 1499–1291cal bp. the uppermost unit is characterized by rather homogeneous fine sands with intercalation of sandy 396 fig. 7 – sm veggiano cross section (a) and location map (b). profilo stratigrafico di sm veggiano (a) e sua ubicazione (b). p. mozzi et al. silt, for an overall thickness of 4–5 m, attributed to the present tesina padovano river. 5.6. s1 borehole this 20 m deep borehole was drilled about 500 m south of the bacchiglione river in the town of selvazzano dentro (fig. 8). starting the description from the bottom, a 3 m thick fine-grained sand body is here covered by 8 m of silty clay, with a peat layer at 16.7 m depth. at 9 m depth, the silty clay sequence is cut by an erosive surface, on which lies a gravelly sand body about 5 m thick. this layer is heterogeneous as for gravel fraction: the coarsest fraction (2–4 cm) is at the bottom, 9.0–7.8 m depth; between 7.8–6.4 m, pebbles reach the maximum size of 1.5 cm; the mean dimensions rise to 2–3 cm between 6.4–5.0 m depth, where common reworked carbonatic nodules are also present; the finest fraction (rare pebbles of 0.5–1 cm) is in the uppermost tract, 5.0– 3.8 m depth. pebbles mainly consist of carbonate rocks, with common flint, metamorphic rocks (gneiss, schists) and porphyry. a fining upward sequence is present from 3.8 m depth to surface, ranging from fine sand to clay. the stratigraphy of this borehole is coherent with that of sm veggiano section and, though no radiometric dating of deposits is here available, the following correlations are proposed: the silty clay sequence is regarded as belonging to the lgm sequence, due to its typical fine-grained lithofacies with common peat layers; the gravelly sand layer correlates with the brenta river coarse sand and gravel unit of sm veggiano. the fine-grained sediments which close the sequence can be attributed to the recent sedimentary activity of the bacchiglione river, and are equivalent to the fine sands and mud deposits of the tesina padovano river at sm veggiano. 6. the holocene channel belts geomorphological and stratigraphic data indicate that the alluvial plain west of padua is characterized by the presence of two holocene channel belts, cut in lgm sediments and locally bounded by low (<2m) erosive fluvial scarps (fig. 2). the lgm deposits are exposed in the northern portion of the study area and in a w–e elongated area just north of the bacchiglione river, on the interfluve between the two channel belts. south of the bacchiglione river, the lgm deposits are mostly buried by middle holocene sediments attributed to the brenta river (cucato & sedea, in press). remote sensing and dtm processing allow good recognition of the northern channel belt, which has a maximum width of ca. 4 km and an overall wnw–ese direction; we refer to it as the “mestrino-rubano” (mr) channel belt. the meander widths, the thickness of the sandy channel bodies and the relative coarse lithofacies and petrography of pebbles indicate that the mr meander belt is the result of the sedimentary activity of the brenta river. radiocarbon datings at ca’ baggio and rubano (see previous paragraph) show that this channel belt was active at the end of lateglacial and in the early holocene. the best preserved palaeohydrographic element is the la storta palaeochannel, which has been mapped for about 13 km (channel length 32 km). available chronostratigraphic data indicate that this palaeochannel was active between 8412–8193 cal bp (ca’ baggio section) and 6568-6297 cal bp (caporello section, castiglioni et al., 1987), bracketing a period of about 2000 years. the remarkable preservation of its morphology is most probably due to the fact that it formed just before the deactivation of mr channel belt, and was thus preserved at surface as a relict fluvial landform. at the western margin of the study area, extensive sand and gravel bodies of the brenta river are found in the sm veggiano cross section, as basal infill of a n-s valley incised in lgm deposits. valley depth was >7 m in respect to the surrounding lgm alluvial plain, and probably averaged around 10 m. some radiocarbon datings on tree trunks and wood fragments embedded in the gravels, as well as the presence of reworked early bronze age pottery shards, indicate channel deposition approximately between 6000–3500 cal bp. one radiocarbon date suggests that the last gravel deposition took place between the 2nd and the 5th century ad, whereas another shows that the residual channel fill was forming between the 6th and 8th century ad. facies assemblages and petrography of pebbles allow to correlate these deposits to the sand-and-gravel sedimentary body cored at selvazzano dentro, few kilometres downstream along the present course of the bacchiglione river. this evidences the existence of a brenta channel belt with a n-s direction down to trambacche along the tesina padovano river valley, which continued ese towards padua following the same direction as the present bacchiglione river. this channel belt, to which we refer as the “veggiano – selvazzano” (vs) channel belt, is significantly younger than mr. its geomorphic evidence is poor, as palaeochannels are mostly buried by the fine sandy and silty deposits of the tesina padovano and bacchiglione rivers. however, about 5 km southwesw of the city centre near volta brusegana, a large abandoned meander is still detectable on aerial photographs, lidar, and 19th century historical maps. the channel width (about 90 m) and the large radius (about 400 m) allow to attribute this meander to the brenta river rather than to the bacchiglione river. it is thus part of vs channel belt, as indicated in map of fig. 2. the meanders of padua city centre were interpreted in previous studies as the downstream continuation of la storta palaeochannel (castiglioni et al., 1987; balista & rinaldi, 2005). detailed mapping with lidar and new remote sensing images indicates that this may not be the case, as la storta palaeochannel runs at the northern outskirts of the city. the meanders in padua are related to a more southern course of the brenta river, which was probably running along the vs channel belt and entered the present urban area along the same direction which was later followed by the bacchiglione river. 7. conclusions the new geomorphological and chronostratigraphic data presented in this paper integrate previous studies on the palaeohydrography of the alluvial plain of padua in relation to early human settlements. 397palaeohydrography and early settlements in padua (italy) ... there are evidences that the last time that the brenta river reached the city centre of padua, it was arriving from the southwesw along the vs channel belt. after deactivation, the bacchiglione river replaced the brenta river along this channel belt. chronostratigraphic data indicate that the vs channel belt was active in the 2nd millennium bc. this implies that padua was crossed by the brenta river during the bronze age. a single radiocarbon dating suggests that the sedimentary activity of the brenta river along vs channel belt may have prolonged as late as the 5th century ad. such indication brings about the possibility that the brenta river may have been flowing through the city also during the iron age and in roman times, and that the bacchiglione river established its present course only in early medieval times. this hypothesis has important implications for the reconstruction of the topography of ancient padua. however, it is based on rather weak chronostratigraphic evidence, which should be better investigated in the future. some controversial points also need to be considered. the presence of such a large river in iron age and roman padua seems to be inconsistent with geoarchaeological data, which point to only minor fluvial activity in the city since the end of the 2nd millennium bc (balista & rinaldi, 2005). another critical issue is that the brenta river is regarded to have followed the present direction since the beginning of the 1st millennium bc (castiglioni et al., 1987; pellegrini et al., 1984), which means that in the iron age and in roman times the river would have been flowing several kilometres east of the city. 8. acknowledgments this investigation has been carried out within the project “padova underground: a geoarchaeological investigation of the city”, funded by fondazione cariparo (department of geography university of padua and soprintendenza per i beni archeologici del veneto). lidar data and historical cartography in the city centre were kindly pro398 fig. 8 stratigraphic log of s1 borehole at selvazzano dentro (a) and location map (b). log stratigrafico del sondaggio s1 a selvazzano dentro (a) e sua ubicazione (b). p. mozzi et al. vided by the municipality of padua. the dem from cartographic data was developed in collaboration with arpav (regional agency for environmental protection in veneto). we gratefully thank g.b. castiglioni for allowing the use of original unpublished data concerning the site of santa maria di veggiano and for contributing to their discussion. 9. references arpav (2005) carta dei suoli del veneto, scala 1:250,000. arpav, osservatorio regionale suolo. aspes a. (ed.) (1984) il veneto nell’antichità. preistoria e protostoria. verona, banca popolare di verona, 2 vol., 897 pp. baggio p., sigalotti g.b. & zamboni c. (1992) analisi territoriale di aree periurbane: il nord-ovest di padova. in: padova nord-ovest. archeologia e territorio, editoriale programma, padova, 19-60. balista c. (2004) il contesto geomorfologico e paleoidrografico. in: ruta serafini a., tuzzato s. (eds.), la necropoli patavina di via umberto i, quaderni di archeologia del veneto, 20, 91–102. balista c. & rinaldi l. (2005) i percorsi pre-protostorici del fiume brenta a padova. in: de min m., gamba m., gambacurta g. & ruta serafini a. (eds.), la città invisibile. padova preromana. trent'anni di scavi e ricerche, tipoarte, bologna, 11–21. bassani m. (2010) pergere viam. da altino a padova. in: rosada g, frassine m. & ghiotto a.r. (eds.), viam anniam influentibus palustribus aquis eververatam, tradizione mito, storia e katastrophé di una strada romana, canova, treviso, 73–84. beach t.p. & luzzadder-beach s. (2008) geoarchaeology and aggradation around kinet höyük, an archaeological mound in the eastern mediterranean, turkey. geomorphology, 101, 416–428. berendsen h.j.a. & stouthamer e. (2000) late weichselian holocene palaeogeography of the rhine-meuse delta. palaeogeogr. palaeoclimatol. palaeoecol., 161, 311–335. bianchin citton e. (ed.) (1993) ricerche interdisciplinari lungo il corso del fiume bacchiglione tra cervarese s. croce e saccolongo. quaderni di archeologia del veneto, 9, 112–129. bondesan a., primon s., bassan v., fontana a., mozzi p., abbà t., vitturi a. (eds.) (2008) carta delle unità geologiche della provincia di venezia. cierre edizioni, verona, 2 sheets, 160 pp. bondesan a., fontana a., mozzi p., piovan s., primon s. (2010) la geomorfologia del territorio dell’annia. in: rosada g, frassine m. & ghiotto a.r. (eds.), viam anniam influentibus palustribus aquis eververatam, tradizione mito, storia e katastrophé di una strada romana, canova, treviso, 25-36. bonetto j. (2009) padova. in: bonetto j. (ed.), veneto. archeologia delle regioni d’italia, istit. poligrafico dello stato, roma, 287–316. bosio l. (1981a) problemi topografici di padova preromana. in: fogolari g. & chieco bianchi a.m. (eds.), padova preromana, antoniana s.p.a industria grafica, padova, 3–9. bosio l. (1981b) padova in età romana. organizzazione urbanistica e territorio. in: bosio l., dei fogolari g., chieco bianchi a.m., pellegrini g.b., sartori f., bassignano m.s., prosdocimi a. & forlati tamaro b. (eds.), padova antica. da comunità paleoveneta a città romano-cristiana, lint, trieste, 229–248. brown a.g. (1997) alluvial geoarchaeology: floodplain archaeology and environmental change. cambridge university press, cambridge, 377 pp. brown a.g. (2008) geoarchaeology, the four dimensional (4d) fluvial matrix and climatic causality. geomorphology, 101, 278–297. carton a., bondesan a., fontana a., meneghel m., miola a., mozzi p., primon s. & surian n. (2009) geomorphological evolution and sediment transfer in the piave river watershed (north-eastern italy) since the lgm. géomorphologie: relief, processus, environnement, 3, 37–58. castiglioni g.b. (1982a) abbozzo di una carta dell’antica idrografia nella pianura tra vicenza e padova. scritti in onore di aldo sestini, società di studi geografici, firenze, 183–197. castiglioni g.b. (1982b) questioni aperte circa l’antico percorso del brenta nei pressi di padova. atti e mem. accad. patav. sc. lett. ed art., 94, 159–170. castiglioni g.b. (1992) esempi veneti relative alla carta geomorfologica (in preparazione) della pianura padana. in: “atti del seminario di studio: tipologia di insediamento e distribuzione antropica nell’area veneto-istriana dalla protostoria all’alto medioevo, asolo, 3-5 novembre 1989”, edizioni della laguna, monfalcone, 292–305. castiglioni g.b., girardi a. & rodolfi g. (1987) le tracce degli antichi percorsi del brenta per montà e arcella nei pressi di padova: studio geomorfologico. mem. sc. geol., 34, 129–149. chieco bianchi a.m. & tombolani m. (eds.) (1988) i paleoveneti. regione del veneto (venezia) and editoriale programma (padova), 149 pp. cucato m. & sedea r. (eds.) (in press) note illustrative del foglio 147 monselice. carta geologica d’italia alla scala 1:50,000, ispra-geological survey of italy and regione del veneto. cupitò m. (2006) l'insediamento neolitico di altichiero padova. notizia preliminare. in: pessina a. & visentini p. (eds.), preistoria dell'italia settentrionale studi in ricordo di bernardino bagolini. atti del convegno udine, 23-23 settembre 2005. museo friulano storia naturale, pubblicazioni varie, 53, 489–494. de min m., gamba m., gambacurta g. & ruta serafini a. (eds.) (2005) la città invisibile. padova preromana. trent’anni di scavi e ricerche. edizioni tipoarte, bologna, 181 pp. de vanna l. & ruta serafini a. (1995) padova, via giustiniani. nuovo padiglione pediatrico. nota preliminare sulle indagini 1993 e 1994. quaderni di archeologia del veneto, 9, 18–25. favero v. (1994) caratteristiche geomorfologiche principali. in: bassan v., favero v., vianello g. & vitturi a. (eds.), studio geoambientale e geopedologico del territorio provinciale di venezia parte meridionale, provincia di venezia, venezia, 55–70. ferrarese p., mozzi p., veronese f. & cervo f. (2006) high resolution dtm for the geomorphological and geoarchaeological analysis of the city of padua (italy). in: campana s. & forte m. (eds.), 399palaeohydrography and early settlements in padua (italy) ... from space to place, 2nd international conference on remote sensing in archaeology, 4-7 november, 2006, british archaeological reports, international series, 1568, 291–296. fogolari g. & chieco bianchi a.m. (eds.) (1981) padova preromana. antoniana s.p.a industria grafica, padova, 307 pp. fontana a. (2006) evoluzione geomorfologica della bassa pianura friulana e sue relazioni con le dinamiche insediative antiche. monografie museo friulano storia naturale, 47, 288 pp. (with enclosed the geomorphological map of the friulian low plain, scale 1:50,000). fontana a., mozzi p. & bondesan a. (2008) alluvial megafans in the venetian–friulian plain (northeastern italy): evidence of sedimentary and erosive phases during late pleistocene and holocene. quat. int., 189, 71–90. fontana a., mozzi p. & bondesan a. (2010) late pleistocene evolution of the venetian–friulian plain. rend. fis. acc. lincei, 21, suppl. 1. gasparotto c. (1951) padova romana. l'erma di brentschneider, roma, 187 pp. gatto p. & previatello p. (1974) significato stratigrafico, comportamento meccanico e distribuzione nella laguna di venezia di una argilla sovraconsolidata nota come “caranto”. c.n.r., laboratorio per lo studio della dinamica delle grandi masse, tech. report 70, venezia. gloria a. (1876) studi intono al corso de’ principali fiumi del territorio padovano dal secolo i a tutto il secolo xi. rivista periodica dei lavori della regia accademia di scienze, lettere e arti, 27, 129–176. groppo v. (2005) abitato: scheda 42. via viii febbraio – via del municipio, ex storione. in: de min m., gamba m., gambacurta g. & ruta serafini a. (eds.), la città invisibile: padova preromana. trent'anni di scavi e ricerche, tipoarte, bologna, 89–91. kidder t.r. (1996) perspectives on the geoarchaeology of the lower mississippi valley. engineering geology, 45, 305–323. iliceto v., meloni f., mozzi p. & rizzetto f. (2001) il sottosuolo della cappella degli scrovegni a padova. geol. tec. ambient., 9, 3–17. leonardi g. (ed) (1990) l’area archeologica del c.u.s.piovego, padova: relazione preliminare della campagna di scavo 1989, con note metodologiche. quaderni di archeologia del veneto, 6, 11–53. leonardi g. (1993) ricerche territoriali a padova nordovest. quaderni di archeologia del veneto, 9, 11–26. miola a., bondesan a., corain l., favaretto s., mozzi p., piovan s. & sostizzo i. (2006) wetlands in the venetian po plain (northeastern italy) during the last glacial maximum: interplay between vegetation, hydrology and sedimentary environment. review of palaeobotany and palynology, 141, 53–81. mozzi p. (2005) alluvial plain formation during the late quaternary between the southern alpine margin and the lagoon of venice (northern italy). geogr. fis. din. quat., suppl. 7, 219–230. mozzi p. (2008) acque di monte, acque di pianura. in: selmin f. & grandis c. (eds.), il bacchiglione, cierre edizioni, sommacampagna (verona), 6–32. mozzi p., bini c., zilocchi l., becattini r. & mariotti lippi m. (2003) stratigraphy, palaeopedology and palynology of late pleistocene and holocene deposits in the landward sector of the lagoon of venice (italy), in relation to the “caranto” level. il quaternario, 16(1bis), 193–210. mozzi p., furlanetto p. & primon s. (2004) capitolo 4.v.1. la geomorfologia tra naviglio brenta e bacchiglione. in: bondesan a. & meneghel m. (eds.), geomorfologia della provincia di venezia, esedra, padova, 269–283. mozzi p. & ninfo a. (2009) la fotografia aerea obliqua per l'analisi geoarcheologica del territorio della via annia. in: veronese f. (ed.), via annia. adria, padova, altino, concordia, aquileia. progetto di recupero e valorizzazione di un'antica strada romana, il poligrafo, padova, 103–120. mozzi p., ninfo a. & piovan s. (2010) nuove evidenze da telerilevamento a sud di padova. in: rosada g, frassine m. & ghiotto a.r. (eds.), viam anniam influentibus palustribus aquis eververatam, tradizione mito, storia e katastrophé di una strada romana, canova, treviso, 85–88. murst (1997) carta geomorfologica della pianura padana. selca, firenze, 3 sheets. ninfo a. (2003) studio geomorfologico della pianura del fiume bacchiglione tra montegalda e selvazzano. unpublished msc thesis, dipartimento di geografia, università degli studi di padova, padova. pirazzini c. (2005a) abitato: scheda 8. piazza castello 8, casa del clero (ex brolo). in: de min m., gamba m., gambacurta g. & ruta serafini a. (eds.), la città invisibile. padova preromana. trent'anni di scavi e ricerche, tipoarte, bologna, 80–82. pirazzini c. (2005b) abitato: scheda 56. via ospedale 20, palazzo vedovotto. in: de min m., gamba m., gambacurta g. & ruta serafini a. (eds.), la città invisibile. padova preromana. trent'anni di scavi e ricerche, tipoarte, bologna, 97–99. pellegrini g.b., paganelli a. & penso d. (1984) aspetti geomorfologici e palinologici dei depositi fluviali nei dintorni di carturo sul brenta (padova). geogr. fis. din. quat., 7, 36–39. reimer p.j., baillie m.g.l., bard e., bayliss a., beck j.w., blackwell p.g., bronk ramsey c., buck c.e., burr g.s., edwards r.l., friedrich m., grootes p.m., guilderson t.p., hajdas i., heaton t.j., hogg a.g., hughen k.a., kaiser k.f., kromer b., mccormac f.g., manning s.w., reimer r.w., richards d.a., southon j.r., talamo s., turney c.s.m., van der plicht j. & weyhenmeyer c.e. (2009) intcal09 and marine09 radiocarbon age calibration curves, 0–50,000 years cal bp. radiocarbon, 51, 1111–1150. stuiver m. & reimer p.j. (1993) extended 14c database and revised calib radiocarbon calibration program. radiocarbon, 35, 215–230. stuiver m., reimer p.j. & reimer r.w. (2010) calib 6.0 radiocarbon calibration . available at: http://calib.qub.ac.uk/calib/. 400 ms. ricevuto il 19 ottobre 2010 testo definitivo ricevuto il 27 ottobre 2010 ms. received: october 19, 2010 final text received: october 27, 2010 p. mozzi et al. imp.digregorio&piras map of the landscape units and geomorphosites of monte arci (sardinia) felice di gregorio & giuseppe piras department of geology, via trentino 51, 09127 cagliari e-mail: geoam@unica.it abstract: f. di gregorio & g. piras, map of the landscape units and geomorphosites of monte arci (sardinia). (it issn 0394-3356, 2005). in the present paper a geomorphosites map is presented in which these sites are inserted in landscape units. the study area is the volcanic complex of monte arci in central-west sardinia. by means of a detailed geomorphological mapping, performed with the aid of photo-interpretation and direct surveys in the field, different types of landscapes have been identified, according to their specific lithological, morphological and evolutive characteristics, that also have determined different types of landuse. it has been possible to distinguish the landscape system of the pliocene volcanites of monte arci that has been further subdivided in the following landscape units: landscape unit of the acid lava’s; landscape unit of the intermediate lava’s; landscape unit of the alkaline trachites; landscape unit of the basic lava’s. the eastern flank is substantially very different and is characterised by the landscape system of the marine miocene sedimentary deposits and the intra-miocene volcanites, with recurrent rounded hills in marly-sandy terrains with discontinuous and sporadic outcropping of infrasedimentary volcanic products mostly in relief. the western flank instead is characterised by the landscape system of the continental plio-quaternary sedimentary deposits, with flat and downhill landforms such as glacis and alluvial mostly inactive cones. inside each of these landscape units several géomorphosites have been identified, mapped and classified according to their genesis, all with own specific scientific, didactic and cultural-tourist interests. this type of analysis and cartographic representation allows to comprise inside these fundamental reference units (landscape units and systems) single punctual geomorphologic elements, showing their genesis in a better way, their spatial distribution and density and the possible relation with their surrounding environment. this kind of map constitutes a valid basic information that allows to evaluate the potential experience of the landscape as a fundamental instrument of knowledge in the territorial and landscape planning and in environmental impact assessment studies. riassunto: f. di gregorio & g. piras, carta delle unità di paesaggio e dei geomorfositi del monte arci (sardegna). (it issn 03943356, 2005). nel presente lavoro viene presentato un esempio di cartografia dei geomorfositi inseriti all’interno delle unità di paesaggio che li contengono. l’area presa in considerazione è quella del complesso vulcanico del monte arci nella sardegna centro-occidentale. tramite un dettagliato rilevamento geomorfologico, condotto con l’uso della fotointerpretazione e di rilevamenti diretti in campo, nell’area sono state identificate alcune tipologie di paesaggio in base agli specifici caratteri distintivi geolitologici, morfologici ed evolutivi, ai quali corrispondono anche ben definite tipologie di utilizzazione del suolo. in sostanza, è possibile distinguere nel monte arci il sistema di paesaggi delle vulcaniti plioceniche che, a sua volta, può essere classificato nelle seguenti unità: unità di paesaggio delle lave acide; unità di paesaggio delle lave intermedie; unità di paesaggio delle trachiti alcaline; unità di paesaggio delle lave basiche. da questo si differenzia sostanzialmente il settore orientale, caratterizzato dal sistema di paesaggi dei depositi sedimentari marini miocenici e delle vulcaniti intramioceniche, contraddistinto dalla ricorrenza di morbide forme collinari concave alla base e convesse verso l'alto, in terreni marnoso-arenacei con affioramento discontinuo e sporadico, generalmente in emergenza, dei prodotti lavici infrasedimentari. il settore occidentale è, invece, caratterizzato dal sistema di paesaggi dei depositi sedimentari continentali plio-quaternari, con forme pianeggianti e pedemontane, quali glacis e conoidi alluvionali, per lo più inattive. all’interno di ciascuna unità di paesaggio sono stati identificati e cartografati i geomorfositi presenti distinti in base al processo genetico e al livello di interesse scientifico, didattico e turistico-culturale. questo tipo di analisi e di rappresentazione consente di ricomprendere all’interno delle unità fondamentali di riferimento (unità di paesaggio e sistemi di paesaggi) i singoli elementi geomorfici puntuali, lineari o areali, di esplicitarne meglio la genesi, la distribuzione e la densità nello spazio geografico. questo metodo di analisi e rappresentazione costituisce una valida base conoscitiva per valutare il potenziale di esperienza del paesaggio, nella pianificazione territoriale e paesaggistica e negli studi di valutazione di impatto ambientale (via). keywords: geomorphosites, landscape units, landscape systems, central-west sardinia, monte arci, valorisation. parole chiave: geomorfositi, unità di paesaggio, sistema di paesaggi, sardegna centro-occidentale, monte arci, valorizzazione. il quaternario italian journal of quaternary sciences 18(1), 2005 volume speciale, 267-273 268 f. di gregorio & g. piras 1. introduction in the present paper a géomorphosites map is presented in which these sites are inserted in landscape units. the study area is the volcanic complex of monte arci in central-west sardinia. the landscape unit represents a fundamental taxonomic unit in a methodological approach of mapping of the resources of a territory based especially on its physical characteristics (clemente, 1987; di gregorio, 1987; piacente et al., 2000; poli et al, 1994; romani, 1994; turri, 1979); this allows to describe with greater detail the areas with a recurrent lithological, morphological and pedological pattern that are genetically related, or else geographical units with specific, distinctive and homogeneous characteristics of formation and evolution (tricart & kilian, 1979; piacente, 1999; romani, 1994; sestini, 1963). this approach also permits to individuate significant elements of the landscape (panizza, 1988), as has clearly been demonstrated by earlier experiences such as the territorial landscape plan of the emilia-romagna region (1987). the landscape units are generally considered singularly or in association with other units forming systems with peculiar genetic or evolutive connections; in other cases the landscape units are subdivided in single components depending on the complexity of the study area and of the desired cartographic detail (fao, 1983). the recognition of landscape units and systems is possible by means of methods for the territorial analysis of vast regions, essentially based on remote sensing techniques or on aerial photo-interpretation. the principal fundament of validity of this type of approach relies on the fact that the landscape configuration, using geomorphologic analysing method, is the easiest characteristic of the physical attributes of a territory to recognise, classify and represent. in particular, according to the lithologic-morphologic criteria it is possible to individuate different fundamental landscape units all of which give birth to spatial entities characterised by a distinct set forms and different from others on the base of the single constituting components. in this manner a classification of the geographic space is configured, principally based on the analysis of the geological constitution and the characterising landforms, considering that these are the expression of the evolution and of a dynamical earth surface that is realised by the interference of natural and human processes and phenomena. regrouping the landscape units with homogeneous genetic and evolution characteristics it is possible to define landscape systems. thanks to the recognition and the classification of these distinct litho-morphological units it is thus possible to make an easier reading of the territory and a more immediate and accurate qualification of the natural resources, in particular of those that constitute the peculiar physical traits because collocated in the same spatial context; in contemporary it is possible to individuate the situations of interference between natural and human factors, or a combination of these, for a more rational use and tutelage of the same resources and a better insertion in eventual settlements and infrastructures in the natural and human existing landscape (clemente, 1987). this methodology has been applied in the monte arci area, in central-west sardinia, collimating particularly the attention on the relationship between geosites and géomorphosites, landscape units and systems (tab. 1). 2. geological and geomorphological aspects of monte arci monte arci is an important tertiary and plioquaternary volcanic complex characterised by a wide variety of effusive rocks and interesting structural or residual landforms derived from ancient palaeogeographic and palaeoclimatic events. the products of the volcanic activity that can be found on monte arci are referable to two different chronological events, each of which have distinct precise volcanologic and geodynamic characters. to the intra-miocene volcanism, referable to the tectonic evolution of the western mediterranean (cherchi & montadert, 1982) are correlated mostly discontinuous outcrops intercalated in the marly-arenaceous miocene sediments of marmilla (maccioni, 1969; 1974), constituted of basic rocks with calco-alcaline affinities, related to a submarine volcanism dated 19÷5 my (savelli, 1975; di paola et al., 1975). such outcrops are constituted, from bottom to top, by submarine pillow lava’s with infrasedimentary hyaloclasts and monogenetic breccia of pillow lava’s with minor presence of hyaloclasts. to the late-pliocene cycle the emission of the lava’s that have originated the volcanic complex of monte arci during distensional phenomena of the continental sardinian plate and the formation of the tectonic graben of campidano are attributed, with basic, intermediate and acid rocks related to subaerial volcanism. radiometric dating (belluomini et al., 1970; belluomini & taddeucci, 1970; savelli, 1975; di paola et al., 1975; bigazzi et al., 1976; beccaluva et al., 1985; montanini, 1992; montanini & villa, 1990, 1993) has allowed to date the pliocene volcanic activity between 5 and 2.6 my. the succession of volcanic products recognised by several authors (di paola et al., 1975; beccaluva et al., 1975, 1977; assorgia et al., 1975; 1976), from bottom to top is represented by: acid lava’s, constituted of rhyolite-rhyodacite flows with transition of lithoid facies to perlite-obsidian facies with associated pyroclastic levels; intermediate lava’s, mainly dacitic and subordinately andesitic, with evident slabby fissuring; alcaline trachites, sometimes passing to vitrophyric facies; basic lava’s, separated in basaltic andesites, basalts with an alkaline chemistry and subalcaline basalts; the plio-quaternary continental sedimentary deposits are mainly composed of: conglomerates, sands and more or less compact clays, mainly composing alluvial cones and glacis (ancient alluvium auct.); recent and present alluvium along river beds. altogether monte arci has a typical form of elliptic ridge elongated in n-s direction that reaches its highest altitude at the neck named trebina longa (812 m a.s.l.). the western sector that overviews the campidano is composed of volcanic flows, mostly rhyolite, deeply cut by valleys that flow into the plain. the eastern sector is characterised by a morphology of plateau with different almost horizontal plains limited by rocky cliffs and steep surfaces that form a clear contrast with the sweet hills of the marmilla. 269map of the landscape units ... 3. the landscape systems and units of monte arci to facilitate the individuation of the géomorphosites, according to the definition given by barca & di gregorio (1991) and by panizza & piacente (1989), on monte arci firstly the territory has been subdivided in landscape units and systems (fig. 1). in more detail, using lithological and morphological criteria the main tab. 1 systems and landscape units of monte arci. sistemi e unità di paesaggio del monte arci. landscape system landscape unit location general morphology summary of main physical features 1 plio-quaternary recent and modern riu florissa, more or less vor enclosed valleys sedimentary-continental alluvium of main river riu tumboi, u-shaped enclosed waterfalls deposits beds gora tappoi valleys glacis and alluvial pranu tiria, pranu forru, largely inactive glacis glacis fans madala, mandronis, and alluvial fans alluvial fans sa giara, pira inferta s’argioledda 2 pliocene volcanic basic lava flows pranu terra, pranu near horizontal or basalt plateaus rocks mallu,pranu santa lucia, gently undulating temporary wetlands su tasureddu, campu basic lava plateaus dykes serrau, apruna, acqua and lava flows necks marzana, arrideli, lava domes benazzeddus, corona column jointing su pardu, pranu murta, pranu pira, pranu sibiriu trachytic lava flows punta quebiois, is benas rugged, porphyry small cavities and serra arruidroxiu, punta and intensely tafoni s’orziada, punta masoni honeycomb-weathered slightly enclosed perdu, rocce su rock outcrops valleys colombariu near vertical walls intermediate lava costa pisu, braxelogu, gently inclined lava lava flows flows (andesite and pranu piccinu, flows often fractured fractures with slab dacite) cuccuru mattivi, conca and slab-like, like geometry mraxi, bruncu su copiu surrounded by near near vertical rock vertical rock walls walls enclosed valleys pseudo-karst cavities waterfalls acid lava flows punta laccu sa vitella, rugged landforms enclosed valleys (rhyolitic, rhyoliticgenna spina, perdas with steeply inclined pyroclastic rhyodacitic) often in urias, punta nicola slopes, sharp breaks sequences perlite-obsidian pani, conca s’ollastu, of slope and obsidian deposits facies, sometimes punta su cantareddu, enclosed valleys tafoni associated with mt. sparau perlite quarries pyroclastic strata 3 miocene sedimentary marly-sandy cea pedrixi, repetitive, gently repetitive rolling marine deposits and sediments sa spendula, rolling hills on hills intra-miocene intercalated with truncheddu, cannisone, marly-sandy terrains enclosed valleys volcanic rocks submarine basic pranu espis, serra with discontinuous pillow lavas pillow or brecciated craboni, pala sa murta, and sporadic outcrops waterfalls lavas, with su entosu, santa maria, of intrasedimentary associated corona fraus lava products hyaloclastites 270 f. di gregorio & g. piras 1 2 3 1 1 1 2 2 2 2 2 2 2 3 3 3 villa verde pau ales pitzu tenuru zeppara pr an u es pi s p.ta pizzighinu apruna corongiu sitzoua rocca tressa is m urus trebina longa conca mraxi trebina lada p.ta trunconi p ar is d e b en as is b en as p.ta perda de pani cuccuru mattivi pranu pira curcuris pompu masullas morgongiori p ra nu is f og ai as conca cannas rocce su colombariu p ra nu s ib iri u siris c orona f raus su p ia li uras villaurbana pr an u m al lu p ra m ar ra da c osta p isu pranu terra monte 'e cresia tiria pranu tiria c am pu t om as u pranu santa lucia campu forru pira inferta masongius b r a x e l o g u p.ta corongiu mela p.ta pranu staddas genna spina genna cruxi perdas urias sant'anna escovedu usellus p ra nu m ur ta 2 1 1 1 2 p.ta su zippiri conca s'ollastu cuc.ru aspru landscape system of the pliocene volcanites acid lava's, constituted of rhyolite-rhyodacite flows with transition of lithoid facies to perlite-obsidian facies with associated pyroclastic levels intermediate lava's, mainly dacitic and subordinately andesitic, with evident slabby fissuring alcaline trachites, sometimes passing to vitrophyric facies basic lava's, separated in basaltic andesites, basalts with an alkaline chemistry and subalcaline basalts landscape system of the continental plioquaternary sedimentary deposits conglomerates, sands and more or less compact clays (ancient alluvium auct.) debris recent and present alluvium along river beds, alluvial cones and glacis landscape system of the marine miocene sedimentary deposits and the intra-miocene volcanites marly-arenaceous miocene sediments of marmilla; submarine pillow lava's with infrasedimentary hyaloclasts and monogenetic breccia of pillow lava's with minor presence of hyaloclasts. limit of landscape system faults and fractures town geomorphosites conventional signs legend 1 2 3 fig. 1 – map of the landscape units and systems of monte arci carta dei sistemi e unità di paesaggio del monte arci. 271 geomorphological units have been identified, all of which give rise to a landscape with precise, distinctive and homogeneous genetic and evolutive characters. following these criteria the landscape systems have been recognised and, for each of these, have been distinguished the landscape units and also the single physiographic components present in them. practically, from the performed research using detailed field work and photo-interpretation, it has been possible to distinguish the landscape system of the pliocene volcanites of monte arci that has been further subdivided in the following landscape units: landscape unit of the acid lava’s, characterised by an articulated and uneven morphology especially where massive rhyolites crop out, with steep sides and clear breaks of slope where the less resistant perlite-obisian facies are surfacing and the presence of a well developed fluvial network, typical of the western flank; landscape unit of the intermediate lava’s, characterised by a plateau morphology on the lava flows recognisable by the slabby fissuration of the rocks; landscape unit of the alkaline trachites with landforms prevalently related to meteoric subaerial processes with hollows and tafoni; landscape unit of the basic lava’s characterised by table-like morphologies bordered by vertical cliffs or steep slopes. from these units the eastern flank is very different, characterised by the landscape system of the marine miocene sedimentary deposits and the intramiocene volcanites, characterised by recurrent rounded hills in marly-sandy terrains with discontinuous and sporadic outcropping of infrasedimentary volcanic products mostly in relief. the western flank instead is characterised by the landscape system of the continental plio-quaternary sedimentary deposits, with flat and downhill landforms such as glacis and alluvial mostly inactive cones. 4. the geomorphosites inside the landscape units of monte arci many géomorphosites have been identified (tab. 2) that represent a high didactic and scientific value, as testimonies of particular past and still ongoing evolutive geological and geomorphological processes (barca et al., 1997; di gregorio & piras, 1997). some of these géomorphosites can be considered as single or isolated elements (sa perda sperrada, the columnar fissuring of is aruttas santas, the andesitic megapillow of gutturu forru and the isolated outcrops of pillow lava’s, the volcanic necks of trebina longa and trebina lada, the waterfalls of sa spendula and su fustiolau) others are better identified as linear morphotypes (the cliffs of conca mraxi and the pyroclastic levels at their foot, the river riu tumboi and its tributaries, the emerging basaltic dykes of is murus, corongiu sitzoua, acquafrida, paris de benas, sa dispensa) or as aerial more or less relevant sites (the basaltic plateau of pranu santa lucia and the temporary wetlands called paulis on its summit, the tafoni of is benas, rocce su colombariu and conca s’ollastu, the steppe-like environments of campu forru and pranu tiria). some of these sites (the hypogean neolithic burial of su segretu de sa conch’e s’omini, the nuragic hypogean temple of sa grutta de is coambus, the obsidian sites of perdas urias, conca cannas and tzipaneas) have a great archaeological interest, as testimonials of the life and the artefacts of the ancient populations that have lived in this territory, founding the seam of the nuragic culture started with the industry of the obsidian that took up the confront with many other mediterranean cultures. 5. conclusions geomorphosites are among the multiple and complex environmental components of the landscape that need to be studied and on which whatever territorial and environmental planning should be based, occupying a fundamental role for their value as a non renewable resource, sometimes unique for their intrinsic characteristics. possible risks for the integrity or the complete destruction of this heritage can be avoided only by a detailed territorial analysis founded on the impact assessment of the projects regarding the occupation of the soil, the use of the natural resources and the urbanisation. by means of a detailed geomorphological mapping, performed with the aid of photo-interpretation and direct surveys in the field, different types of landscapes have been identified at monte arci (central-west sardinia), according to their specific lithological, morphological and evolutive characteristics, that also have determined different types of landuse. inside each of these landscape units several géomorphosites have been identified, mapped and classified according to their genesis, all with own specific scientific, didactic and cultural-tourist interests. this type of analysis and cartographic representation allows to comprise inside these fundamental reference units (landscape units and systems) single punctual geomorphologic elements, showing their genesis in a better way, their spatial distribution and density and the possible relation with their surrounding environment. this kind of map constitutes a valid basic information that allows to evaluate the potential experience of the landscape as an fundamental instrument of knowledge in the territorial and landscape planning and in environmental impact assessment studies. the cartographic work of recognition of the landscape units and systems has allowed to identify various géomorphosites. the adopted analysis and the evaluation of these géomorphosites inside a physiographic reference unit permits to reveal a predominance of sites in the landscape units of the tertiary volcanic rocks, showing a more relevant geodiversity and a higher multiple value (di fidio, 1990) of landscape elements that can be used for e recreational experience of the landscape by geotourism. map of the landscape units ... 272 f. di gregorio & g. piras tab. 2 – geomorphosites of monte arci. i geomorfositi del monte arci. landscape system of the pliocene volcanic rocks name municipality location i.g.m. reference genetic rock type genetic classification definition basalt flows landscape unit 1 trebina longa morgongiori porteddu murus 539 iv mk78300288 volcanic basalt volcanic necks trebina lada 2 pranu santa lucia villav. usellus pranu santa lucia 529 iii mk82450798 volc.-struct. basalt volcanic plateau 3 paulis del pranu santa lucia villav.usellus pranu santa lucia 529 iii mk83050950 lacustrine basalt temporary basins 4 sa perda sperrada masullas perda sperrada 539 iv mj79039546 struct.-meteoric basalt morphosculpture 5 “is murus” dyke marrubiu is murus 539 iv mk76930385 volcanic basalt outcropping dyke 6 “corongiu sitzoua” marrubiu corongiu sitzoua 539 iv mk76930495 volcanic basalt outcropping dyke dyke 7 “acquafrida” dyke ales acquafrida 529 iii mk78200593 volcanic basalt outcropping dyke 8 “paris de benas” morgongiori paris de benas 539 iv mk78340113 volcanic basalt outcropping dyke dyke 9 “sa dispensa” dyke palmas arborea sa dispensa 529 iii mk77810878 volcanic basalt outcropping dyke 10 is aruttas santas villaurbana is aruttas santas 529 iii mk78631228 volc. – struct. and.– basalt. columnar jointed basalt columns basalt intermediate lava flows landscape unit 11 “cliffs” at conca ales pau conca mraxi 539 iv mk80750245 struct. slope rhyolite sheer volcanic mraxi morgongiori dacite walls 12 “sa spendula” ales cadresa 539 iv mk80250338 fluvial – struct. dacite waterfall waterfall 13 riu tumboi and villaurbana riu tumboi 529 iii mk80051245 fluvial – struct. dacite – and. small fluvial valleys affluents 14 sa grutta de is morgongiori punta santu marcu 539 iv mk79950093 anthropogenic dacite natural cavities coambus hypogeum temple ipogeo 15 su segretu de sa villaurbana braxelogu 529iii mk80101043 anthropogenic dacite natural cavities conch’e s’omini hypogeum alkali trachitic lava flows landscape unit 16 is benas morgongiori is benas 539 iv mk79250150 meteoric trachyte honeycombed rock 17 rocce su masullas rocce su 539 iv mj77989695 meteoric trachyte honeycombed rock colombariu colombariu acid lava flows landscape unit 18 conca s’ollastu marrubiu conca s’ollastu 539 iv mk73550217 meteoric rhyolite honeycombed rock morgongiori 19 layers of ales conca mraxi 539 iv mk80750245 volcanic pyroclastic pyroclastic pyroclastic rock morgongiori rock sequences 20 conca cannas masullas conca cannas 539 iv mj77389713 volcanic rhyolite obsidian deposit obsidian deposit 21 perdas urias pau perdas urias 529 iii mj80360621 volcanic rhyolite obsidian deposit obsidian deposit sennixeddu 22 tzipaneas marrubiu tzipaneas 539 iv mk76530371 volcanic rhyolite obsidian deposit obsidian deposit landscape system of the miocene marine sedimentary deposits and intramiocene volcanic rocks 23 “fustiolau” pau truncheddu 539 iv mk80930684 fluvial – struct. marl – aren. waterfall waterfall 24 megapillow at masullas gutturu forru 539 iii mj83509418 volcanic andesite andesitic gutturu forru megapillow 25 – outcrops of masullas siris santa maria 539 iv mj79089557 volcanic basalt – and. pillow lava pillow lava morgongiori pala sa murta landscape system of the plio-quaternary continental sedimentary deposits 26 – steppe palmas arborea campu forru 529 iii mk76111039 fluv. – anthrop. alluvia steppe environments at oristano pranu tiria environments and campu forru and lakes in hills pranu tiria references assorgia a., beccaluva l., di paola g.m., maccioni l., macciotta g., puxeddu m., santacroce r. & venturelli g. (1975) carta geopetrografica del complesso vulcanico del monte arci (sardegna) 1:50.000 grafiche step, parma. assorgia a., beccaluva l., di paola g.m., maccioni l., macciotta g., puxeddu m., santacroce r. & venturelli g. (1976) il complesso vulcanico del monte arci (sardegna centro-occidentale), nota illustrativa alla carta geopetrografica 1:50.000 boll. soc. geol. it., 95, pp. 371-401. barca s. & di gregorio f. (1991) conservation et valorisation du patrimoine géologique de la sardaigne (italie): une proposition methodologique i symposium intern. “protection du patrimoine géologique”, digne-les bains, france, pp. 1-19. barca s. & di gregorio f. & piras g. (1997) la cartografia tematica per il rilevamento dei monumenti geologici e geomorfologici. l’esempio del monte arci (sardegna centro-occidentale) rend. sem. fac. sc. univ. cagliari, suppl., 67, pp. 123-147. beccaluva l., deriu m., maccioni l., macciotta g. & venturelli g. (1975) il massiccio vulcanico di monte arci (sardegna centro-occidentale). nota preliminare rend. soc. it. min. petrol., 31, pp. 1069-1080. beccaluva l., deriu m., macciotta g., savelli c. & venturelli g. (1977) geocronology and magmatic characters of the pliocene-pleistocene volcanism in sardinia (italy) bull. volcanol., 40, pp. 1-15. beccaluva l., civetta l., macciotta g. & ricci c.a. (1985) geochronology in sardinia: results and problems rend. soc. it. min. e petrol., 40, pp. 57-72. belluomini g. & taddeucci a. (1970) studi sulle ossidiane italiane. contenuto e composizione isotopica dell’uranio e del torio period. min., 39, pp. 387-395. belluomini g., discendenti a., maliperi l. & nicoletti m. (1970) studi sulle ossidiane italiane. ii contenuto in 40ar radiogenico e possibilità di datazione period. min., 34, pp. 469-479. bigazzi g., bonadonna f.p., maccioni l. & pecorini g. (1976) research on monte arci (sardinia) subaerial volcanic complex using the fission-track method boll. soc. geol. it., 95, pp. 1555-1570. cherchi a. & montadert l. (1982) il sistema di rifting oligomiocenico del mediterraneo occidentale e sue conseguenze paleogeografiche sul terziario sardo mem. soc. geol. it., 24, pp. 387-400. clemente f. (ed.) (1987) cultura del paesaggio e metodi del territorio janus, cagliari. di fidio m. (1990) architettura del paesaggio pirola ed., milano. di gregorio f. (1987) criteri e metodi per la conoscenza e la conservazione attiva dell’ambiente in: f. clemente (ed.), cultura del paesaggio e metodi del territorio, janus, cagliari. di gregorio f. & piras g. (1997) le carte tematiche per la valorizzazione dell’ossidiana e dei geotopi del monte arci, sardegna” atti della 1a conferenza nazionale a.s.i.t.a.: “le immagini e le informazioni territoriali”, parma 30 settembre 3 ottobre 1997, pp. 360-366. di paola g.m., puxeddu m. & santacroce r. (1975) kar ages of monte arci volcanic complex (centralwestern sardinia) rend. soc. it. min. petrol., 31, pp. 181-190. fao (1983) guidelines on land evaluation for rainfed agriculture. maccioni l. (1969) ialoclastiti e pillow-lave nel miocene della marmilla (sardegna centro-occidentale) rend. sem. fac. sc. univ. cagliari, 39, pp. 207220. maccioni l. (1974) nuovi rinvenimenti di lave a cuscino nel miocene della marmilla (sardegna centro-occidentale) rend. sem. fac. sc. univ. cagliari, 43, pp. 277-282. montanini a. (1992) petrology and geochemistry of monte arci volcanic complex (western sardinia) plinius, 7, pp. 91-96. montanini a. & villa i. m. (1990) new 40ar/39ar dating of monte arci volcanic complex (sardinia, italy) plinius, 3, pp. 77-79. montanini a. & villa i. m. (1993) 40ar/39ar chronostratigraphy of monte arci volcanic complex (western sardinia, italy) acta vulcanologica, 3, pp. 229233 panizza m. (1988) geomorfologia applicata la nuova italia scientifica, roma. panizza m. & piacente s. (1989) cultura del paesaggio e offerta turistica atti conv. int. “turismo e ambiente nella società post-industriale”, milano, 9-10 marzo, pp. 839-844. piacente s. (1999) la conoscenza scientifica, un valore aggiunto in g. poli (ed.), geositi testimoni del tempo , regione emilia romagna, serv. paesaggio, ass. progr., ed. pendragon, bologna, pp. 234-244. piacente s., bertacchini m., coratza p. & malmusi s. (2000) il patrimonio geologico: nuova occasione di sviluppo turistico e culturale. un esempio in emilia romagna atti conv. “sviluppo economico e sostenibilità. il turismo ambientale e culturale, occasione di nuova occupazione”, 2-6 novembre 1999, anacapri, pp. 561-565. poli g., scarelli m. & gisotti g. (1994) i paesaggi geologici italiani (1) verde ambiente, 2, suppl. puxeddu c. (1955) giacimenti di ossidiana del monte arci in sardegna e sua irradiazione studi sardi, 14-15, parte i, pp. 10-66. regione emilia romagna (1987) piano territoriale paesistico regionale relazione generale ass., edil., urban., regione emilia romagna, zanini edizioni, bologna. regione liguria (1986) piano territoriale paesistico, relazione generale. romani v. (1994) il paesaggio, teoria e pianificazione milano, franco angeli. savelli c. (1975) datazioni preliminari col metodo k-ar di vulcaniti della sardegna sud-occidentale rend. soc. min. petrol., 31, pp. 191-198. sestini a. (1963) il paesaggio tci, milano. tricart j. & kilian j. (1979) l’écogéographie et l’aménagement du milien natural libr. francois maspero, paris. turri e. (1979) semiologia del paesaggio italiano longanesi, milano. 273map of the landscape units ... imp.salvini& ricostruzione del paleoalveo del fiume serchio (lucca, italia) tramite rilievi lidar, foto aeree ed immagini quick bird r. salvini 1, e. guastaldi 1, n. coscini 2, n. del seppia 2 1 centro di geotecnologie, università degli studi di siena – salvinir@unisi.it 2 autorità di bacino del fiume serchio, lucca riassunto: r. salvini, e. guastaldi, n. coscini, n. del seppia, ricostruzione del paleoalveo del fiume serchio (lucca, italia) tramite rilievi lidar, foto aeree ed immagini quick bird. (it issn 0394-3356, 2007). in questo lavoro è stata effettuata un’analisi paleomorfologica dell’alveo del fiume serchio partendo da evidenze geomorfologiche attuali e dati storici. a tal fine sono state utilizzate foto aeree di epoche diverse, ortofoto, immagini satellitari quick bird integrate con dati storici biblio-cartografici. l’ortocorrezione geometrica di tutte le immagini è stata effettuata grazie ad un modello digitale del terreno elaborato dalla topografia alla scala 1:10000, dai rilievi topografici disponibili (livellazioni e dgps, ovvero differential global positioning system) e dal rilevo lidar (light detection and ranging) effettuato nel febbraio/marzo 2005. attraverso l’interpretazione di tutti i dati, sono stati ricostruiti a grande scala gli antichi percorsi fluviali nell’area della pianura lucchese. il lavoro è stato condotto in ambiente gis (geographic information system) allo scopo di integrare le informazioni deducibili da dati diversi e rendere evidenti le variazioni spaziali e temporali dell’alveo, con la produzione di una cartografia tematica dedicata. il rilievo aereo lidar ha permesso di generare un ddtm (digital dense terrain model) con passo 1m con il quale sono state effettuate elaborazioni tridimensionali che hanno permesso di evidenziare le aree depresse della pianura lucchese, coincidenti con i vecchi tratti fluviali e con i meandri abbandonati del fiume serchio. abstract: r. salvini, e. guastaldi, n. coscini, n. del seppia, lidar survey, aerial photos and quick bird satellite images for the palaeodrainage reconstruction of serchio river (lucca, italy). (it issn 0394-3356, 2007). in this work the palaeodrainage reconstruction of serchio river has been performed, starting from present and historical geomorphological evidences. for this, aerial photos, orthophotos, quick bird satellite imageries, integrated with historical references have been utilized. the orthorectification of all the imageries have been performed by utilizing a dem (digital elevation model) resulting from the elaboration of numeric topography at a scale of 1:10,000, topographic surveys (dgps and levelling), and lidar aerial survey done in february and march 2005. by the remote sensing data interpretation, the palaeodrainage channels of serchio river have been reconstructed at a large scale for the whole area of lucca plain. through a gis the whole dataset have been managed as geo-database, in order to highlight the spatial and temporal variations of palaeodrainage of serchio river, producing thematic cartography. lidar survey allowed us to generate a ddtm, 1m of spatial resolution, which has been utilized for three-dimensional elaborations, carried out in order to highlight the lowered areas in the lucca plain, which correspond to the palaeodrainage of serchio river. parole chiave: telerilevamento, fotointerpretazione, paleodrenaggio, gis. keywords: ...... il quaternario italian journal of quaternary sciences 19(2), 2006 299-310 1 area di studio il bacino del fiume serchio con una superficie di 1626 km2 è compreso nelle province di lucca, pisa e pistoia (fig. 1). localizzato tra le alpi apuane ed i monti pisani interessa gran parte della piana lucchese e pisana, con una densità di drenaggio di 20.8 km-1, uno sviluppo totale di circa 2194.8 km, con la sola asta principale di lunghezza pari a 105.1 km. le principali caratteristiche morfologiche della piana lucchese unite all’abbondante presenza di acqua sia superficiale che sotterranea e all’intensa azione antropica, hanno contribuito nel tempo alle numerose divagazioni dell’alveo fluviale. al fine di eseguire un’analisi paleomorfologica dell’alveo del fiume, partendo da evidenze geomorfologiche attuali e dati storici, è importante ricostruire le tappe fondamentali dell’evoluzione paleo-geografica dell’area. dopo l’eocene caratterizzato dall’orogenesi appenninica, nel periodo miocenico i fenomeni distensivi hanno determinato una serie di horst e graben, allungati in direzione nw-se, che hanno generato una serie di bacini intermontani tra i quali la depressione tettonica denominata graben del serchio (trevisan et al., 1971). in tale depressione si è sviluppata una serie di bacini lacustri (alta valle del serchio, media valle del serchio e piana di lucca) al l ’ interno dei quali, nel villafranchiano, è cominciata una fase di sedimentazione e colmata. nei bacini dell’alta e media valle, questa fase si è conclusa a causa della modesta entità degli stessi, mentre il vasto lago che occupava la piana di lucca e che si spingeva fino alle pendici del monte albano ha avuto un’evoluzione più complessa (nardi et al., 1987; dallan, 1988). a partire dal pliocene inferiore (rusciniano), l’attuale pianura fu occupata da un vasto bacino lacustre di origine tettonica (semi-graben) formatosi a causa del sollevamento della regione orientale della catena del 300 r. salvini et al. monte albano. il bacino intermontano è stato poi oggetto di un’intensa sedimentazione, rappresentata per lo più da depositi di tipo lacustre, fluviale ed alluviale, che è continuata fino ai tempi storici favorita anche ad una subsidenza tettonica. in questa fase e fino al pleistocene superiore, il sollevamento che si registra ad oriente e i continui episodi di alluvionamento ed impaludamento della pianura dovuti all’innalzamento del letto dell’arno (piazzini 1850), permettono al fiume di bi-partirsi: il bacino viene alluvionato e modellato dal paleoalveo del fiume auser (nome antico del fiume serchio) che, solo tramite il lago di bientina, confluisce nell’arno all’altezza di vico pisano, mentre più ad occidente trova sbocco indipendente un ramo minore, denominato auserculus, che scorre a n di lucca e prosegue verso pisa passando da ripafratta (paderi, 1932). tra il xii e l’viii secolo a.c., il bacino lacustre formatosi nella depressione di bientina raggiunge la quota di 15m s.l.m. lambendo i paesi di capannori, s. filippo e la stessa città di lucca (paderi, 1932) mentre il fiume serchio è ancora bipartito: un ramo, da saltocchio, passa per lammari, lunata e sfocia nella depressione di bientina, mentre l’altro ramo procede verso s, passa ad e di lucca ricevendo le acque della freddana attraverso un collettore a n di m. s. quirico, e scende per la valle di ripafratta (donati, 1784). gli etruschi (v secolo a.c.) incanalano il ramo occidentale del serchio in 2 alvei all’altezza di s. pietro a vico, circondando la città di lucca per scopi difensivi, per poi farli ricongiungere ad occidente, nei pressi di montuolo, e sfociare nell’arno (barsocchini, 1853). in questo periodo, grazie alla sistemazione dei terreni operata da questa civiltà ed all’efficace ruolo drenante svolto più a s dal fiume arno, il livello del lago di bientina diminuisce (circa 6m s.l.m.; paderi, 1932). in epoca pre-romana, sotto la dominazione ligure, a causa dell’abbandono delle opere etrusche e della non curanza del territorio, si ha un impaludamento generale della pianura ad e di lucca e si registrano numerose divagazioni del serchio (barsocchini, 1853). in epoca romana (i secolo a.c. ÷ iv secolo d.c.) vengono ripristinati gli argini artificiali dei 2 rami occidentali del corso del fiume serchio che confluisce nell’arno provocando all’incrocio con questo un evidente fenomeno di “innalzamento” delle acque testimoniato da strabone nel i sec. d.c. (masini, 1956). la pianura ad e di lucca viene bonificata ed i terreni liberati dalle acque della palude vengono centuriati secondo una maglia rettangolare orientata circa nne-ssw. il serchio non alimenta più il lago di bientina, il cui livello torna alla quota di circa 6m s.l.m (paderi, 1932). dopo la caduta dell’impero romano, nel v secolo d.c., il parziafig. 1 ubicazione dell’area di studio (rettangolo nero) su scena landsat5 tm (banda 5): in grigio è visualizzata l'area di competenza dell'autorità di bacino del fiume serchio. location of study area (black box) on landsat5 tm scene (band 5): the grey area represents the serchio river basin authority. le abbandono delle pratiche agricole ed il degrado dei campi innescano nuovi fenomeni di impaludamento e divagazione del fiume verso e (masini, 1956). il serchio, nel nuovo corso principale ormai ad e (barsocchini, 1853) alimenta nuovamente il lago di bientina che risale di livello anche per il contemporaneo aumento di portata delle acque dell’arno (paderi, 1932). dal ramo orientale si dipartono varie divagazioni tra cui una passante per lunata (nome derivante dall’ansa molto pronunciata che il fiume faceva in questa zona), mugnano e parezzana per poi immettersi nel lago di bientina (barsocchini, 1853). il ramo occidentale lambisce a n lucca: fonti storiche testimoniano la distruzione dell’anfiteatro di epoca romana non ancora protetto dalle antiche mura della città risalenti al periodo medioevale (paderi, 1932). testimone dell’impaludamento della pianura e delle divagazioni del fiume è rutilio numanziano che non riesce ad oltrepassare la depressione ad e di lucca per raggiungere da roma la gallia sua patria, né è testimone del fenomeno di “innalzamento” delle acque citato da strabone all’incontro del serchio con l’arno perchè l’acqua non è più convogliata tutta per la stretta di ripafratta, ma tracima in gran parte verso oriente e quindi nel lago di bientina per poi defluire nell’arno a vico pisano (barsocchini, 1853). nel vi secolo d.c., s. frediano vescovo di lucca, ordina la regimazione del serchio presso s. pietro a vico: la massa principale dell’acqua passa nel ramo occidentale a n di lucca, mentre una parte delle acque viene deviata verso e, a formare l’ausere (antico nome dell’attuale ozzeri). questo alveo orientale, all’altezza di antraccoli (dal latino inter aquas) forma un isolotto passando, in parte ad occidente nell’attuale corso del canale ozzeretto fino a pontetetto, e in parte ad oriente dove all’altezza di pieve s. paolo si divide ulteriormente in un ramo secondario che si riversa nel lago di bientina. in seguito, nel viii secolo d.c., il ramo occidentale dell’isolotto di antraccoli volta ad occidente per formare l’ausere e confluisce a montuolo nell’attuale canale ozzeri proveniente più a s da pieve san paolo e pontetetto (paderi, 1932). nel ix secolo d.c. non si hanno più testimonianze dell’ausere (ausere morto); l’ozzeretto confluisce direttamente nell’ozzeri all’altezza di pontetetto e rimane la deviazione nel lago di bientina all’altezza di pieve s. paolo. il serchio in quest’epoca è tripartito nel seguente modo: un ramo segue circa il corso attuale, un secondo ramo si diparte da s. pietro a vico e lambisce a n le mura medioevali di lucca formando un’isola rispetto al rame precedente, mentre il terzo ramo, più orientale, nasce a n di s. pietro a vico, passa per lammari, lunata e antraccoli e poi si riversa nell’ozzeri proseguendo verso montuolo. quest’ultimo ramo, all’altezza di pieve s. paolo, si divide ulteriormente poiché è documentata la presenza di un immissario del lago di bientina (masini, 1956). l’idrografia dell’area si mantiene tale fino a tutto il x secolo d.c.. il lago ha una quota minima (circa 7m s.l.m.) e l’opera di s. frediano ha quindi ancora effetto. dagli inizi dell’xi secolo d.c. l’assetto idrologico peggiora rapidamente con nuove divagazioni del fiume ed impaludamenti della pianura a causa delle lotte tra i lucchesi ed i fiorentini. queste condizioni sfavorevoli si protraggono fino al xiv secolo, quando i lucchesi cominciano ad intraprendere opere di nuova canalizzazione per limitare le esondazioni nella pianura ad e di 301ricostruzione del paleoalveo del fiume serchio ... lucca e convogliare la maggior parte dell’acqua del serchio verso o. nel xv secolo d.c. il livello del lago è più basso (circa 10m s.l.m.) poiché il serchio, in parte regimato con successo, apporta una quantità di acqua inferiore. finalmente nel 1538 i lucchesi riescono a controllare l’andamento del fiume serchio che non defluisce più nel lago di bientina, ma, grazie ad una serie di interventi idraulici, ne viene regimato il corso in modo da scorrere attraverso un alveo arginato e pensile sulla pianura lucchese e su quella pisana fino alla foce presso migliarino (mancini, 1950). il lago di bientina, per le continue lotte tra lucchesi e fiorentini, per tutto il periodo che va dal xvi al xix secolo, subisce numerosi innalzamenti di livello che determinano inevitabili impaludamenti della pianura. a n di vico pisano le lotte riguardano l’apertura di chiuse e cataratte per lo scolo delle acque: nel 1646 le continue diatribe consentono al livello lacustre di raggiungere le porte della città di lucca e capannori. in quest’epoca, durante i periodi di piena, il serchio riesce ancora a rompere gli argini ed a riversarsi nell’ozzeri; contemporaneamente l’acqua del lago di bientina è in grado di tracimare nel canale rogio e quindi procedere anch’essa nell’ozzeri, in senso opposto al serchio, con il risultante impaludamento di tutta l’area a s-se di lucca. la bibliografia testimonia di continue opere di regimazione nel tentativo di limitare le esondazioni del serchio verso e. fonti storiche documentano che il 6 novembre 1623 il fiume rompe gli argini da poco costruiti fra saltocchio e lucca, si rovescia nelle campagne e riprende il naturale corso orientale arrivando a devastare bientina e vicopisano; il 18 novembre 1750 il serchio in piena rompe l'argine sinistro nei pressi di s.anna e un ramo del fiume esce allagando tutta la campagna fino a scaricarsi nel lago di bientina. notizie storiche narrano che gli abitanti di queste zone fuggono terrorizzati verso la città e per dar loro asilo vengono aperte eccezionalmente le porte in mezzo alla notte. nel 1665 viene costruita la nuova serezza, un canale artificiale nella pianura ad e di lucca, realizzato con l’obiettivo di drenare il lago di bientina verso vico pisano; l’opera di per se da buoni risultati, anche se registra alcuni insuccessi relazionati al contemporaneo innalzamento del livello di base del fiume arno dovuto alle grandi quantità di sedimenti depositati ed alle ingenti torbe provenienti dalla val d’era (repetti, 1846). per ordine di leopoldo ii granduca di toscana, nel 1859 viene inaugurata la “botte” sotto il letto dell’arno, un canale artificiale costruito per far defluire l’acqua della serezza nell’emissario verso il mare all’altezza del calambrone. i risultati non sono però del tutto positivi in quanto vaste plaghe di terreno rimangono paludose: i possessori di una parte del terreno da bonificare, unitisi in consorzio verso il 1907, provvedono successivamente all'istallazione di idrovore per il risanamento idraulico dei terreni mediante il sollevamento meccanico delle acque (bracaloni, 1977). 2 analisi per lo studio del paleodrenaggio del fiume serchio sono state utilizzate in maniera integrata varie fonti: modello digitale delle superfici (dsm) e modello 302 digitale del terreno (dtm), con passo uguale a 1m, derivanti da ripresa lidar effettuata ad una quota media di volo di 1500m nel febbraio/marzo 2005 con laser scanner altimetrico (sensore digitale optech altm 3033) di proprietà della cgr (compagnia generale riprese aeree) di parma; foto aeree a colori naturali, alla scala nominale 1:7000, riprese nel febbraio/marzo 2005 dalla cgr, realizzate ad una quota media di volo di 4500m (scansione a 1200 dpi, risoluzione 0.15m al suolo); ortofoto a colori naturali in scala 1:10000 relative al volo italy2000 (sezioni n°261110, 261140, 261150, 273020 e 273030); immagine satellitare quick bird datata 18 marzo 2003 (tipo standard, pancromatica e multispettrale con risoluzione spaziale rispettivamente di 0.61m e 2.44m); cartografia tecnica regionale in formato vettoriale alla scala 1:10.000. per i dati storici è stato fatto riferimento all’archivio di stato della città di lucca, alla biblioteca storica della certosa di calci (pi) ed alle numerose pubblicazioni presenti in letteratura. il lavoro è stato condotto in ambiente gis, mediante il software esri arcmaptm, allo scopo di integrare le informazioni deducibili da dati diversi e rendere evidenti le variazioni spaziali e temporali dell’alveo, con la produzione di una cartografia tematica dedicata. all’interno del geodatabase creato, ogni elemento spaziale relativo ai paleoalvei è stato completato da informazioni morfologiche, evolutive e storiche basandosi anche su fonti bibliografiche passate (barsocchini, 1853; paderi, 1932; masini, 1956; ambrosi, 1967; mazzanti & pasquinucci, 1983, nardi et al., 1987). le foto aeree, in formato digitale, sono state orientate secondo tecniche fotogrammetriche (kraus, 1994) mediante il software erdas imaginetm, utilizzando i dati relativi al volo (certificato di calibrazione della camera wild rc30) ed i gcp (ground control point) rilevati con strumentazione gps in modalità differenziale statica. le foto aeree, orientate con un’accuratezza posizionale di 0.20m e altimetrica di 0.40m, sono state interpretate mediante filtri polarizzanti permettendo così l’osservazione stereoscopica dei paleoalvei e dell’intera piana di lucca. per quanto riguarda l’elaborazione dell’immagine quickbird, essa è stata ortorettificata al fine di eliminare le distorsioni geometriche derivanti dall’orografia della zona e dalla modalità di acquisizione del dato, secondo scansione pushbroom. per questo sono stati utilizzati gcp derivanti dai rilievi dgps integrati al modello digitale del terreno elaborato dalla topografia alla scala 1:10000 e integrato con il rilevo lidar. trattandosi di un prodotto standard, vale a dire non soltanto corretto radiometricamente ma anche geometricamente impiegando informazioni desunte unicamente dalla telemetria ed utilizzando un modello digitale del terreno a bassa risoluzione, l’ immagine quickbird è stata fornita già proiettata secondo il sistema utm, datum wgs84, con un’accuratezza dichiarata in termini ce 90% migliore di 23m, escludendo spostamenti legati alla topografia ed all’angolo di vista offnadir. l’ortocorrezione è stata quindi effettuata mediante una procedura razionale “non-rigorosa” (toutin & cheng, 2002) basata sulla correzione polinomiale a partire dai coefficienti disponibili nel file rpc (rational polynomial coefficient), successivamente raffinati con i gcp derivanti dai rilievi dgps. essendo gran parte dell’area di lavoro di tipo pianeggiante, le correzioni geometriche apportate con il procedimento illustrato sono risultate soddisfacenti; tuttavia, a causa della scarsa accuratezza (alcuni metri) riscontrata nelle zone montuose, si è preferito ricorrere alla utilizzazione di una ulteriore correzione geometrica secondo il metodo cosiddetto rubber sheeting (saalfeld, 1985; white & griffin, 1985; buiten, 1993). peculiarità del metodo è quella di non restituire scarti quadratici medi dell’operazione di correzione, pertanto la verifica dell’accuratezza è stata effettuata mediante check points ed a posteriori sovrapponendo alle immagini pancromatica e multispettrale corrette, i punti rilevati con strumentazione gps. in queste zone l’errore medio di posizionamento è risultato pari a 1.5m. infine, avendo a disposizione separatamente l’immagine pancromatica e quella multispettrale geometricamente corrette e co-registrate, al fine di incrementare la risoluzione spaziale di quest’ultima mantenendo la multispettralità, sono state effettuate operazioni di fusione secondo il metodo di resolution merge a mezzo delle componenti principali (chavez et al., 1991). l’immagine multispettrale quickbird di elevata risoluzione è stata utilizzata in visione monoscopica per l’identificazione dei paleoalvei sfuggiti allo studio delle foto aeree grazie alla disponibilità della banda 4 relativa all’infrarosso vicino (range spettrale 0.76÷0.9 micron). l’identificazione dei paleoalvei è stata effettuata anche grazie alla accurata morfologia prodotta dalle riprese effettuate con il laser scanner altimetrico optech altm 3033 di proprietà della cgr. lo strumento utilizzato, potendo registrare simultaneamente oltre all'intensità del segnale di ritorno le riflessioni "primo impulso" e "ultimo impulso", quando il laser incontra un ostacolo (es. foglie, fili sospesi, cornicioni) viene diviso in più componenti che vengono riflesse verso l'alto in tempi diversi (kraus & pfeiefer, 1998; kraus, 2002). questo consente di separare ciò che è al di sopra del terreno (dsm) da ciò che giace su di esso (dtm). le riprese sono state estese ad un’area di circa 2600ha a sud della città di lucca. l’attività di rilievo lidar si è articolata nelle fasi seguenti: pianificazione del volo, esecuzione del rilievo, elaborazione dei dati, controllo di qualità e creazione dei prodotti finali. in sede di collaudo è stata verificata la precisione di misura dei prodotti forniti dalla cgr in rapporto a quella richiesta nel disciplinare tecnico predisposto dall’autorità di bacino (a.d.b.) del fiume serchio ed è stata valutata l’accuratezza degli stessi prodotti, tramite il confronto con dati a terra rilevati con tecnica topografica tradizionale. i prodotti soggetti al collaudo sono stati il dsm e il dtm riferiti al sistema di nazionale gauss-boaga con quote ortometriche. le attività svolte per il collaudo sono state, nell’ordine, le seguenti: esecuzione di un rilievo topografico con gps e strumentazione tradizionale, su alcune aree-campione interne all’area oggetto del lavoro (fig. 2), da parte di uno studio tecnico-topografico incaricato dalla stessa a.d.b.. il rilievo di verifica ha previsto la predisposizione di una rete di inquadramento dell’area di rilievo r. salvini et al. 303 realizzata con tecnica gps-statica raffinata con operazioni di post-processing rispetto alla stazione gps permanente allestita dalla provincia di lucca di coordinate ellissoidiche note (hofmann-wellenhof et al., 1997; cina, 2000). la rete è stata ricondotta alla quota ortometrica grazie a due capisaldi di livellazione dei quali sono note sia la quota ortometrica che quella ellissoidica. sono stati inoltre rilevati (con tecnica gps-cinematica a partire dai caposaldi di inquadramento) i piani quotati di cinque piazzali dislocati all’interno dell’area oggetto delle riprese lidar, scelti in corrispondenza di superfici topografiche regolari e in assenza di interferenze aeree (che sono fonte di possibili disturbi locali del segnale lidar e che per questo avrebbero potuto falsare il collaudo – fig. 2). considerando i valori di accuratezza altimetrica richiesti nel disciplinare tecnico del lavoro (nell’ordine di 20cm) e la regolarità delle superfici dei piazzali, i punti sono stati battuti con una distanza reciproca media nell’ordine di 5m.: la compensazione dei rilievi è avvenuta vincolando le coordinate geoidiche note dei capisaldi di inquadramento; generazione di un dtm e di un dsm di verifica, con passo uguale a quello prodotto nell’ambito del lavoro da collaudare (1m), sulla base dei dati del rilievo topografico di verifica. a partire dai piani quotati rilevati a terra sono stato generati, con due diverse metodologie, i dati necessari per il confronto con i prodotti da collaudare. in particolare, tramite il software esri arcinfo®, sono stati ricavati modelli digitali raster formato grid con dimensioni della cella pari a 1m e modelli triangolari delle superfici tin (triangular irregular network). il limite esterno delle aree su cui sono stati ricostruiti i modelli digitali è stato mantenuto almeno 1m all’interno del limite geometrico dei piazzali stessi: questo, sia per evitare di confrontare i dati in prossimità di discontinuità altimetriche localizzate come muri perimetrali, scalini o soglie, dove, per sua natura, il dato altimetrico del lidar (che è mediato all’interno della superficie proiettata sul terreno dal fig. 2 area del rilievo lidar e ubicazione dei rilievi topografici di verifica (toponimi sottolineati). lidar survey area and location of topographic check points (bold underlined place-names). ricostruzione del paleoalveo del fiume serchio ... 304 raggio laser) può perdere localmente di precisione, sia per ovviare alle inevitabil i imprecisioni dell’algoritmo di calcolo in prossimità dei bordi. la fig. 3 mostra l’area collaudata presso il piazzale guamo (superficie 2120mq); confronto statistico tra il dtm e il dsm forniti dalla cgr e quelli di verifica generati per il collaudo. i confronti sono stati effettuati secondo tre metodi differenti: con modelli digitali generati a maglia regolare nel formato raster, nel formato triangolare tin e con singoli punti rilevati a terra. sono stati elaborati statisticamente gli scarti altimetrici (intesi come differenza tra il valore di quota ottenuto per interpolazione dei dati gps e quello planimetricamente corrispondente ottenuto con il rilievo lidar) tra i modelli digitali del terreno di verifica e quelli forniti dalla cgr, ottenendo, per ciascuno dei cinque piazzali, i valori di media e deviazione standard degli scarti stessi. il confronto è stato effettuato nel sistema di riferimento roma40, in quote geoidiche. a tale proposito si evidenzia come la conversione dei dati originali del rilievo lidar (espressi in coordinate wgs84 e in quote ellissoidiche) sia stata effettuata dalla cgr sulla base di parametri di adattamento locale del geoide ricavati per conto dell’a.d.b. dall’istituto geografico militare a partire da 44 vertici a quota ortometrica nota. 3 risultati l’interpretazione stereoscopica digitale delle foto aeree, lo studio monoscopico multispettrale dell’immagine quickbird e quelle delle ortofoto, insieme alle informazioni di quota deducibili dal dtm hanno permesso la ricostruzione a grande scala degli antichi percorsi fluviali del fiume serchio. sulla base delle informazioni storiche disponibili e dei rapporti tra gli alvei riconosciuti la ricostruzione della sequenza, dai più antichi ai più recenti, è stata effettuata secondo i seguenti intervalli temporali: epoca pre-romana: intervallo comprensivo di tutte le informazioni riferibili al neogene, all’età del ferro (xii÷viii a.c.), all’epoca etrusca (viii÷iv secolo a.c.) ed alla successiva dominazione ligure (iv÷iii a.c.). epoca romana (i÷iv secolo d.c.): i terreni della pianura ad e di lucca, una volta liberati dalle acque della palude, vengono centuriati con una maglia rettangolare orientata circa nne-ssw. v secolo d.c.: periodo post-imperiale di impaludamento e divagazione verso e del fiume dovuti al parziale abbandono delle pratiche agricole e di difesa territoriale. vi∏viii secolo d.c.: periodo di interventi idraulici e controllo delle corso delle acque in seguito alle disposizioni di s. frediano vescovo di lucca. ix secolo d.c.: periodo del serhio “tripartito” e dell’ausere morto. x÷xiv secolo d.c.: intervallo temporale di nuovo impaludamento e divagazione verso e del fiume come conseguenza della lotta tra lucca e firenze. xiv÷xvi secolo d.c.: periodo di nuovi interventi idraulici e di parziale controllo del corso delle acque verso o. xvi÷xix secolo d.c.: periodo successivo al 1538, quando i lucchesi riescono a regimare il serchio che non defluisce più nel lago di bientina. tale intervallo di tempo è comunque caratterizzato da insuccessi, esondazioni ed impaludamenti della pianura che, comunque, riguardano esclusivamente la parte più meridionale. termina con il 1859 quando viene inaugurata la botte sotto l’arno. l’interpretazione si è estesa a tutta la pianura ad e di lucca anche in aree esterne al dtm prodotto dal rilievo lidar, comunque analizzabili con i dati telerilevati (fig. 4). la fig. 5 mostra alcuni dettagli dell’interpretazione effettuata sovrapposti all'ortofoto n° 261110. nella zona corrispondente al canale ozzeretto, i dati altimetrici ricavabili dal dtm prodotto dal rilievo lidar hanno consentito un’interpretazione di maggiore dettaglio, poiché alle osservazioni telerilevate si sono accostate informazioni di quota di elevata precisione. il dtm (fig. 6) ha, infatti, permesso di evidenziare le aree depresse di questa zona della pianura lucchese coincidenti per lo più con i vecchi tratti fluviali e con i meandri abbandonati del ramo orientale del fiume serchio. il dettaglio del dtm prodotto dalla cgr, oltre a consentire l’interpretazione dei paleoalvei presentata in fig. 3 piazzale guamo rilevato nella zona puntinata con tecnica gps-cinematica a partire dai caposaldi di inquadramento. guamo square: the dotted area represents the gps-kinematics survey related to reference benchmarks. r. salvini et al. 305 fi g. 4 – f ot oi nt er p re ta zi on e d ei p al eo al ve i d el f iu m e s er ch io , s ov ra p p os ta a l d tm . d tm o ve rla id b y th e p ho to in te rp re tio n of s er ch io r iv er p al ae od ra in ag e. ricostruzione del paleoalveo del fiume serchio ... 306 fig. 5 paleoalvei del fiume serchio sovrapposti all'ortofoto 261110. orthophoto 261110 overlaid by the palaeodrainage of serchio river. fig. 6 dtm generato dal rilievo aereo lidar con sovrapposizione dei paleoalvei del fiume serchio. dtm from the lidar aerial survey, overlaid by the palaeodrainage of serchio river. r. salvini et al. questo lavoro, ha permesso all’a.d.b di individuare e perimetrare le aree a rischio idrogeologico per problemi di stabilità dei versanti secondo quanto previsto dal d.l. 11/6/98, n.180. il collaudo del dtm ha infatti dimostrato l’idoneità del dato disponibile. il disciplinare tecnico dei rilievi con sensore lidar prevede un’accuratezza altimetrica statistica delle misure, corrispondente al valore di deviazione standard campionaria (1dev.st.), variabile in funzione della quota di volo dell’aeromobile. alla quota di volo di 1500m (quota media tenuta in occasione del presente rilievo) tale accuratezza corrisponde a un valore di ±20cm. considerando anche le ulteriori fonti di errore, non precisamente quantificabili, introdotte nelle fasi di inquadramento e rilievo gps di verifica, conversione dei sistemi di coordinate sia per i dati lidar che per quelli di verifica, il dato altimetrico relativo ai piazzali per i quali il valore medio dello scarto si mantiene all’interno della fascia di ±30cm, è stato comunque considerato idoneo alle prescrizioni tecniche di capitolato dettate dall’a.d.b.. i risultati dei confronti della coordinata altimetrica in corrispondenza dei cinque piazzali sono riportati nelle tabelle riassuntive 1 e 2. 307 tab. 1 risultati del confronto tra il dsm della cgr e i dati di verifica. results of comparison between cgr dsm and check data. rilievi topografici dsm (cgr) grid ricavato di verifica dsm (cgr) – dsm grid dsm (cgr) – dsm tin dai soli punti topografici guamo punti di verifica 2128 punti di verifica 2126 punti di verifica 63 media [m] -0.46 media [m] -0.47 media [m] 0.46 dev.st. [m] 0.28 dev.st. [m] 0.28 dev.st. [m] 0.14 montuolo 1 punti di verifica 578 punti di verifica 577 punti di verifica 21 media [m] -0.17 media [m] -0.13 media [m] 0.14 dev.st. [m] 0.09 dev.st. [m] 0.18 dev.st. [m] 0.05 montuolo 2 punti di verifica 326 punti di verifica 326 punti di verifica 30 media [m] -0.10 media [m] -0.10 media [m] 0.01 dev.st. [m] 0.20 dev.st. [m] 0.20 dev.st. [m] 0.52 pontetetto punti di verifica 10507 punti di verifica 10502 punti di verifica 0 media [m] 0.10 media [m] 0.60 media [m] 0.19 dev.st. [m] 1.00 dev.st. [m] 1.02 dev.st. [m] 0.16 sorbano punti di verifica 758 punti di verifica 758 punti di verifica 24 media [m] -0.18 media [m] -0.19 media [m] 0.06 dev.st. [m] 0.29 dev.st. [m] 0.29 dev.st. [m] 0.57 tab. 2 risultati del confronto tra il dtm della cgr e i dati di verifica. results of comparison between cgr dtm and check data. rilievi topografici dtm (cgr) grid ricavato di verifica dtm (cgr) – dtm grid dtm (cgr) – dtm tin dai soli punti topografici guamo punti di verifica 2128 punti di verifica 2126 punti di verifica 63 media [m] -0.50 media [m] -0.51 media [m] 0.50 dev.st. [m] 0.04 dev.st. [m] 0.04 dev.st. [m] 0.04 montuolo 1 punti di verifica 578 punti di verifica 577 punti di verifica 21 media [m] -0.17 media [m] -0.19 media [m] 0.16 dev.st. [m] 0.09 dev.st. [m] 0.09 dev.st. [m] 0.06 montuolo 2 punti di verifica 326 punti di verifica 326 punti di verifica 30 media [m] -0.16 media [m] -0.17 media [m] 0.16 dev.st. [m] 0.04 dev.st. [m] 0.04 dev.st. [m] 0.04 pontetetto punti di verifica 10507 punti di verifica 10502 punti di verifica 87 media [m] 0.20 media [m] 0.20 media [m] 0.26 dev.st. [m] 0.10 dev.st. [m] 0.12 dev.st. [m] 0.16 sorbano punti di verifica 758 punti di verifica 758 punti di verifica 24 media [m] -0.24 media [m] -0.24 media [m] 0.24 dev.st. [m] 0.04 dev.st. [m] 0.04 dev.st. [m] 0.04 ricostruzione del paleoalveo del fiume serchio ... nei piazzali montuolo 1 e 2, e sorbano la precisione di capitolato (1 dev.st.) è rispettata sia nel confronto con il dtm che con il dsm; l’accuratezza delle misure è quindi molto elevata. nel piazzale pontetetto i dati di confronto con il dsm (modello che non è privato della vegetazione) evidenziano una prevedibile diminuzione di accuratezza e precisione (std. dev. intorno a 1m – tab. 1); il fenomeno peraltro non si riscontra nel confronto con i singoli punti misurati a terra. l’algoritmo di generazione del dtm riporta il dato entro le tolleranze richieste e assicura anche una buona accuratezza (tab. 2). per il piazzale guamo la precisione richiesta è rispettata in entrambi i confronti, anche se l’accuratezza della misura è inferiore a quella degli altri piazzali e supera i 30cm, evidenziando uno scostamento sistematico dal dato a terra. considerata l’accuratezza del modello digitale disponibile, si è deciso allora di effettuare un calcolo della profondità delle aree occupate dai vecchi tratti fluviali e dai meandri abbandonati del fiume serchio. la distribuzione di frequenza delle differenze di quota rispetto alla pianura circostante ha evidenziato come le aree sopraelevate, essenzialmente legate a cause antropiche, hanno una quota ortometrica mediamente maggiore di 2.5 m, mentre le aree depresse, riferibili ai canali del paleodrenaggio, sono situate a quote ortometriche mediamente inferiori di 3m (fig. 7). 4 conclusioni l’interpretazione di tutti i dati telerilevati ha permesso la ricostruzione a grande scala degli antichi percorsi fluviali del fiume serchio. i dati storici utilizzati si sono dimostrati di fondamentale aiuto nell’attribuire le corrette collocazioni temporali ai vari tratti del paleodrenaggio del fiume; la trama di divagazioni presenti su tutta la zona intorno lucca, ed in particolare nella pianura ad e della città, è talmente fitta e complessa che sarebbe stato impossibile risalire agli antichi corsi ed alle loro successioni senza un supporto di tipo storico. con questo lavoro si è cercato, infatti, di attribuire ai tratti del paleodrenaggio ancora evidenti una collocazione storica conforme con le notizie bibliografiche disponibili. i dati telerilevati utilizzati si sono dimostrati validi sia in termini di risoluzione spaziale sia di accuratezza posizionale. l’integrazione delle informazioni deducibili da dati diversi ha reso evidenti le variazioni spaziali e temporali dell’alveo, ricostruendo la sequenza temporale evolutiva del percorso dell’antico serchio. la gestione in ambiente gis dei dati fotointerpretati si è rilevata fondamentale per il buon esito del lavoro: la sovrapponibilità delle interpretazioni, la possibilità di assegnare ai vari tratti restituiti degli attributi relativi al tempo, all’evidenza e alla fonte storica di riferimento non sono che alcuni dei grandi vantaggi offerti da un database geografico per un lavoro di questo tipo. lo studio mostra come le moderne tecnologie di telerilevamento quali la fotogrammetria digitale ed il rilevo lidar consentono accurate analisi geomorfologiche, utilizzabili qualitativamente e soprattutto quantitativamente sia per scopi cartografici sia per applicazioni di pianificazione territoriale. l’a.d.b. ha recentemente acquisito nuove foto aeree a colori di elevata risoluzione spaziale ed un rilievo lidar di più grande estensione, relativo a zone fotointerpretate in questo lavoro, che, dopo gli orientamenti ed il collaudo, verranno utilizzati per individuare e perimetrare le aree a rischio idrogeologico e per approfondire le conoscenze morfo-metriche della zona riconducendo la morfologia attuale ai fenomeni idrogeologici che l’hanno determinata. 308 fig. 7 calcolo della profondità delle aree occupate dai vecchi tratti fluviali e dai meandri abbandonati del fiume serchio: a vista prospettica delle differenze di quota di una porzione del paleoalveo; b distribuzione di frequenza delle differenze di quota rispetto alla pianura circostante (in grigio scuro: valori positivi corrispondenti alla diminuzione della quota ortometrica) e statistica descrittiva della distribuzione delle differenze. depth of the areas been part of the palaeodrainage of the serchio river: a – three-dimensional view of the height differences within a part of the palaeodrainage of serchio river; b histogram of height differences in respect to the surrounding flatland (the dark grey bars represent positive values corresponding to orthometric elevation decrease) and statistics of the height differences. a b r. salvini et al. bibliografia ambrosi a. (1967) giornale storico della lunigiana. vol. 18. barsocchini o. (1853) sull'antico corso del serchio. atti della reale accademia lucchese, lucca, vol. 14. bracaloni c. (1977) indagini sulle zone umide della toscana: il padule di bientina, situazione ambientale e relativi problemi di gestione. tesi di laurea in scienze agrarie università degli studi di pisa. buiten h.j. (1993) geometrical and mapping aspects of remote sensing. in: buiten, h. g. and j.g.p.w. clevers (eds.), land observation by remote sensing – theory and applications. gordon and breach science publishers. 297-321. chavez p.s. jr., sides s.c. e anderson j.a. (1991) comparison of three different methods to merge multi-resolution and multi-sectoral data: landsat tm and spot panchromatic. photogrammetric engineering and remote sensing, 57(3): 295-303. cina a. (2000) gps principi, modalità e tecniche di posizionamento. celid editore, torino, isbn 887661-417-6, 40-81. dallan l. (1988) inquadramento geografico e geologico della regione montecarlo altopascio-cerbaie – in: ritrovamento di alephis lyrix nelle argille della serie lacustre di montecarlo (lucca) e considerazioni stratigrafiche sui depositi continentali dell'area tra il monte albano e il monte pisano. atti soc. tosc. sci. nat. mem. serie a, 95, 203 – 219. donati s. (1784) notizie istoriche del serchio suoi antichi nomi e differente corso: col ragionamento sopra l’antica situazione della città di pisa, in lucca: presso francesco bonsignori, 6, 55, biblioteca universitaria di pisa fabroni misc. 208.3 hofmann-wellenhof b., lichtenegger h. e collins j. (1997) gps – theory and practice. springer editore, isbn 3-211-82839-7, 131-305. kraus k. & pfeiefer n. (1998) determination of terrain model in area with airborne laser scanner data. isprs journal of photogrammetry and remote sensing, 53 (4). 193-203. kraus k. (1994) fotogrammetria – vol 1 teoria e applicazioni. edizioni levrotto & bella, torino. kraus k. (2002) principles of airborne laser scanning. journal of the swedish society for photogrammetry and remote sensing, nr. 2002:1/stockholm (2002), issn 1104-5825; 53 56. mancini a. (1950) storia di lucca. sansoni, firenze, 358 pp. masini r. (1956) l'idrografia del serchio nell'epoca preistorica e storica. baroni, lucca. mazzanti r. & pasquinucci m. (1983) l’evoluzione del litorale lunense – pisano fino alla metà del xix secolo. boll. soc. geogr. it.,10-12. nardi r., nolledi g., e rossi f. (1987) geologia e idrogeologia della pianura di lucca. geografia fisica e dinamica quaternaria, vol. 10. paderi e. (1932) variazioni fisiografiche del bacino di bientina e della pianura lucchese durante i periodi storici. mem. della r. soc. geogr. ital., roma, vol. 7-17. piazzini f. (1850) memoria intorno ai diversi progetti concernenti la depressione delle acque del lago di sesto, ossia di bientina e la diversione del fiume serchio. pisa, nistri. repetti e. (1846) dizionario geografico, fisico, storico della toscana, contenente la descrizione di tutti i luoghi del granducato, ducato di lucca, garfagnana e lunigiana, firenze, tofani editore. saalfeld a. (1985) a fast rubber-sheeting transformation using simplical coordinates. the american cartographer, 12(2):169-173. toutin t. & cheng p. (2002) quickbird – a milestone for high resolution mapping. earth observation magazine, 11(4): 14-18. trevisan l., brandi g.p., dallan l., nardi r., raggi g., rau a., squarci p., taffi l. e tongiorgi m. (1971) foglio 105, lucca. note 111. carta geol. d'it., arti grafiche di mauro, cava dei tirreni, 52 pp. white m.s. & griffin p. (1985) piecewise linear rubbersheet map transformations. the american cartographer, 12(2), 123-131. 309 ms. ricevuto il 20 febbraio 2006 testo definitivo ricevuto il 31 ottobre 2006 ms. received: february 20, 2006 final text received: october 31, 20036 ricostruzione del paleoalveo del fiume serchio ... evidence of associated deposition of travertine and calcareous tufa in the quaternary carbonates of valdelsa basin (tuscany) enrico capezzuoli, anna gandin & fabio sandrelli dip. scienze della terra, università di siena, via laterina 8, 53100 siena e.mail: capezzuoli@unisi.it abstract: e. capezzuoli et al., evidence of associated deposition of travertine and calcareous tufa in the quaternary carbonates of valdelsa basin (tuscany). (it issn 0394-3356, 2008). the quaternary continental deposits discontinuously exposed in the southern part of the valdelsa basin, represent four orders of terraces corresponding to four late pleistocene-holocene fluvial/palustrine synthems formed as a consequence of the tectonic uplifting of southern tuscany. in most of the elsa river network the terraces are composed of detrital deposits (mixed, siliciclastic-carbonate silty sands with lenticular interbeds of gravels), but locally, along specific segments of the valleys, the detrital sediments are replaced by lenticular bodies of concretionary limestones made of massive, sometimes highly porous, calcareous tufa that, only in the upstream areas, are interbedded with laminated facies with tabular geometry and fabric typical of travertine. the distribution the different facies can be observed in the upstream part of the imbotroni valley in the locality of bagnoli (se of san gimignano siena). their relationships records the development of a complex depositional system controlled by the intermittent outflow of a thermal spring alternated to seasonal/meteoric fresh water input. when the thermal spring was active, the warm waters fed proximal, shallow pools were well laminated travertine facies were deposited while faraway from the spring and/or during the periods of prevailing meteogene, fresh water input, the massive phytoclastic/phytohermal calcareous tufa formed. a similar depositional evolution appears to have developed at the beginning of all the quaternary carbonate synthems formed in the valdelsa basin, thus explaining the anomalous distribution of the concretionary carbonate deposits, limited only to a segment of the elsa fluvial network. riassunto: e. capezzuoli et al., evidenze della deposizione associata di travertino e calcareous tufa nei carbonati quaternari del bacino della valdelsa (toscana). (it issn 0394-3356, 2008). i depositi continentali quaternari della porzione meridionale del bacino della valdelsa registrano una complessa evoluzione paleoambientale segnata da successive fasi deposizionali condizionate dal sollevamento tettonico che ha interessato l'intera toscana meridionale. quattro ordini di terrazzi fluviali, rappresentanti altrettanti fasi deposizionali fluvio-palustri del pleistocene superiore-olocene, sono esposti in maniera discontinua lungo la valle del fiume elsa e dei suoi tributari (torrente foci, torrente staggia, borro degli imbotroni). essi corrispondono a quattro sintemi fluvio-palustri composti, nella maggioranza dei casi, da depositi detritici misti (sabbie siltose e calcareo-silicoclastiche con intercalati livelli lenticolari conglomeratici). localmente, in particolari segmenti del reticolo fluviale, i sedimenti detritici sono sostituiti da corpi lenticolari di calcari incrostanti rappresentati da calcareous tufa massicci, localmente molto porosi. nella loro porzione più a monte queste stesse facies di calcareous tufa risultano intercalate a facies ben laminate con geometria tabulare e strutture tipiche del travertino. la distribuzione delle differenti facies e i loro rapporti possono essere osservati nella parte superiore del botro degli imbotroni, nella località di bagnoli (se di san gimignano siena) dove la successione consiste di tre unità deposizionali sovrapposte, separate da superfici erosive. le tre sequenze, ognuna composta di due intervalli, mostrano un'evoluzione deposizionale laterale e verticale simile. l'intervallo basale delle tre unità è formato da calcari marnosi peloidali con resti fossili (ostracodi e gasteropodi) associati a corpi lenticolari più o meno porosi di calcareous tufa con ciuffi fitoclastici/fitoermali. solo nella parte basale dell'unità inferiore queste litologie coprono lenti di ciottolami e sabbie siltose silico-carbonatiche. questi ciottolami giacciono con contatto discordante sul substrato pliocenico. l'associazione di facies può essere interpretata come l'evoluzione da un sistema fluviale (facies detritiche) a condizioni palustri-lacustri (calcareous tufa). l'intervallo superiore delle tre sequenze è caratterizzato da calcari ben stratificati e laminati. da dettagliate analisi petrografiche e sedimentologiche, questa litofacies risulta essere composta da lamine batteriali/cianobatteriali (“cespugli” micritici e aggregati peloidali). la laminazione tabulare composta esclusivamente da tappeti batteriali, è caratteristica di sedimenti deposti in ambiente termale, in corpi d'acqua stagnante o con poca energia come stagni o laghetti poco profondi. inoltre, l'assenza di macrofite e di elementi faunistici (ostracodi e gasteropodi) indica caratteristiche chimico-fisiche delle acque (alta temperatura, contenuto in h2so4 e bassi livelli di ossigeno) sfavorevoli alla proliferazione di organismi animali e vegetali superiori. la distribuzione delle facies nella sezione di bagnoli registra quindi, la complessa evoluzione di un sistema deposizionale derivante dall'interazione fra un sistema termale ed uno di acque fredde. le acque termali scorrevano intorno alla sorgente e alimentavano vasche poco profonde dove si depositavano le facies travertinose laminate, mentre nelle aree più distali e durante l'interruzione dell'apporto termale si aveva la deposizione delle facies massicce fitoclastiche/fitoermali tipiche dei calcareous tufa. a testimonianza di ciò, una piccola sorgente debolmente termale, con limitato potere incrostante è tuttora attiva a bagnoli. tale tipo di evoluzione deposizionale sembra aver interessato tutti i sintemi tardo pleistocenici della valdelsa, spiegando così l'anomala distribuzione dei depositi carbonatici concrezionari limitati a segmenti definiti del reticolo fluviale. key words: travertine, calcareous tufa, quaternary, sedimentology, valdelsa. parole chiave: travertino, calcareous tufa, quaternario, sedimentologia, valdelsa. il quaternario italian journal of quaternary sciences 21(1b), 2008 113-124 114 e. capezzuoli, a. gandin & f. sandrelli 1. introduction the study of continental carbonates has greatly increased in the last decades, since it has been known that these lithologies are sensible to the environmental conditions and consequently can convey viable palaeoclimatic information. as a matter of fact many studies have demonstrated that extended and detailed paleoclimatic records can be obtained from the sedimentologic/stratigraphic and geochemical analysis (stable isotopes) of speleothems (ba rma t t h e w s et alii, 1997; dr y s d a l e et alii, 2004), calcrete (dw o r k i n et alii, 2005) and lacustrine limestone (mcke n z i e & ho l l a n d e r, 1993; vo n gr a f e nstein et alii, 2000). comparable information in type and quality resulted also from the study of some lithofacies of continental carbonates precipitated under open-air conditions by flowing waters in streams, rivers (garnett et alii, 2004; andrews, 2006) and springs (frank et alii, 2000; minissale et alii, 2005) from calcium-bicarbonaterich waters. however, the different nomenclature and genetic attributions given by the authors to the open-air flowstones (ri d i n g, 1991; ko b a n & sc h w e i g e r t, 1993; pe n t e c o s t, 1995; fo r d & pe d l e y, 1996; ca p e z z u o l i & gandin, 2004) emphasize the present limited knowledge of the genetic processes of these deposits and the absence of a common point of view (ga n d i n & ca p e zzuoli, this volume). the term travertine, which for a long time has been used to designate the ornamental/building stone quarried in the thermal deposits of tivoli, is now generally reserved to calcium carbonate deposits associated to hydrothermal spring systems. this lithology which is relatively enriched in strontium, sulphur (ford & pedley, 1996) and 13c, and as a consequence is characterized by high values (pentecost, 1995) of total dissolved inorganic carbon (tdic), appears to be barely dependent upon climate. it is characterized by high depositional rates, regular bedding and fine lamination, a primary, low-porosity crystalline fabric, and by bacteria and cyanophites as the only organic constituents (gandin & capezzuoli, this volume). on the other hand, the term calcareous tufa, coined in the british literature, refers to calcium carbonate deposits formed under a cool-water regime, around karst spring complexes and/or in a fluvio-palustrine environment. this lithology which is depleted in 13c and shows tdic concentrations more or less in equilibrium with the soil atmosphere (ford & pedley, 1996) appears to be highly dependent upon climatic factors. it is characterized by normally low depositional rates, commonly lenticular, highly porous bodies with poor bedding, and abundant remains of microand macrophytes, invertebrates as well as bacteria. the distinction between these two groups of lithotypes is not univocal since the cool water calcareous tufa deposits can represent the natural lateral prosecution, away from the thermal-spring complex, of cooled thermal waters. the discrimination of the two types of deposits appears to be crucial in the interpretation of the tectonic, climatic and anthropologic meaning of the fossil continental carbonates. however preliminary, compared analyses of the fabric of travertine and calcareous tufa in formation, show the possibility of using petrologic criteria for their distinction. here is an example from the late pleistocene-holocene carbonate deposits of the southern valdelsa basin (southern tuscany, italy). 2. geological setting the valdelsa basin is one of the larger neogenequaternary basins of southern tuscany, bordered to the west and the south by the middle-tuscan ridge and to the east by the chianti ridge (fig. 1). the tuscan ridge mainly consists of formations of the tuscan domain, comprising metamorphic triassic siliciclastics (verrucano facies), late triassic/jurassic carbonates and the “calcare cavernoso”, a carbonate epidiagenetic breccia derived from tectonized triassic evaporitic deposits (ga n d i n et alii, 2000). the chianti ridge is mainly composed of tectonically superposed units of the ligurian domain ranging from middle-late jurassic ophiolites, early cretaceous shales and flinty limestones and late cretaceous eocene flysch successions of sandstones, limestone and shales. the valdelsa basin developed since the late miocene, experienced during the neogene mixed continental-marine conditions represented by a thick sequence of mainly siliciclastic deposits (about 2000 m; ghelardoni et alii, 1968). in the late middle pliocene a general marine regression led the valdelsa basin, as well as the greatest part of southern tuscany, to emersion (bossio et alii, 1995). this event seems to be related to a major tectonic uplifting that affected southern tuscany in successive pulses from middle pliocene up to the present (ca r m i g n a n i et alii, 1994; bo c c a l e t t i e t alii, 1999; bartolini, 2003). the persistent erosional regime acting on this area since the neogene, has been episodically interrupted during quaternary, by recurrent depositional episodes represented by seven synthems locally characterized by terrestrial calcareous deposits (ca p e z z u o l i & sa n d r e l l i, 2004; ca p e z z u o l i et alii, 2007). the oldest, early-middle pleistocene deposits (campiglia dei foci cdf; strove synthems str) consist of lacustrine to palustrine limestones, while the subsequent four, late pleistocene-holocene synthems (abbadia abb; calcinaia cal; torrente foci foc; bellavista bel) are locally characterized by calcareous, fluvial-palustrine deposits. the youngest, holocene poggibonsi synthem (pog) is represented by exclusively siliciclastic, fluvial sediments (fig. 2). all synthems are bounded by basal disconformable contacts and upper subhorizontal aggradational surfaces on which rubefied or brown soils developed (capezzuoli & sandrelli, 2004; capezzuoli et alii, 2007). the late pleistocene-holocene synthems, exposed in a succession of terraces on the slopes of the river valleys, mainly consist of detrital deposits (sands, silts and pebbles) that in some valleys are associated with or replaced by calcareous deposits. the detrital deposits are usually represented by irregular, fining-upward sequences composed of quartz-sands and silt with gravel lenses associated with clastic calcareous sands. the gravel layers, mainly developed in the basal part of the synthems, are composed of well rounded, poorly sorted (max 20 cm) polygenic clasts of ligurian and “calcare cavernoso” provenance, and of a variable amount of sandy matrix. the quartz sand derives from the surrounding pliocene marine sands while the calcareous sands appear to result from the erosional fragmentation of older calcareous deposits. in specific segments of the valdelsa network (fig. 115evidence of associated deposition ... fig. 2 schematic reconstruction of the quaternary stratigraphic units in southern valdelsa (not to scale) (after capezzuoli et alii, 2007, modified). ricostruzione schematica delle suddivisioni stratigrafiche adottate per lo studio dei depositi quaternari del settore meridionale della valdelsa (non in scala) (da capezzuoli et alii, 2007, modificato). fig. 1 geological scheme of the southern valdelsa basin. the abb, cal, foc, bel synthems cannot be mapped separately at this scale. schema geologico semplificato della porzione meridionale del bacino della valdelsa. i sintemi abb, cal, foc, bel non possono essere rappresentati separatamente a questa scala. 1), namely along the elsa river (between gracciano val d'elsa to the south and poggibonsi to the north) and along its tributaries staggia creek (between castellina scalo and poggibonsi), imbotroni creek and foci creek (near san gimignano and campiglia dei foci) the detrital deposits are extensively replaced by poorly stratified, lenticular bodies of encrusting carbonates. the dominant lithofacies include phytoclastic and phytohermal concretionary limestones resulting from the incrustation of macrophytes (rushes, bryophytes and grass stems) associated with calcrete, calcareous sands and occasionally peat clays and/or micritic layers. these facies, characteristic of paludal/fluviatile calcareous tufa (sensu pe d l e y, 1990 and pe d l e y et alii, 2003) can be related to relatively high concentrations of ca-bicarbonate in the flowing waters hence to high water supply and karstic circulation in the carbonate yielding substrate. the age of the continental carbonates of the valdelsa basin, previously referred to the holocene (merla & bortolotti, 1967), has been recently updated. 14c radiometric dating of organic clays occurring in the basal part of the intermediate cal synthem yielded a late pleistocene age of 25.690±180 years b.p. (capezzuoli & sandrelli, 2004). the thickness of the different carbonate successions is variable, progressively decreasing from the oldest (abb) to the youngest (bel) synthem. the peculiar distribution of the concretionary carbonates, limited to specific fluvial tracts of the four carbonate synthems, cannot be understood only in terms of karstic activity/climatic depositional conditions. although the dominant facies represented by poorly bedded/massive chalky limestone can be referred to calcareous tufa, well-bedded, laminated, compact limestone bearing the features of travertine, locally occur at their base in the apical part of the paleovalleys. aim of this paper is the detailed analysis and the definition of the origin and relationships of the apical lithofacies of one of these successions (foc synthem) exposed at bagnoli (fig. 1), a locality se of san gimignano, near siena. 3. the bagnoli succession at bagnoli the carbonate succession located upstream of the imbotroni valley in the apical part of the torrente foci (foc) is well exposed in a section about 15 m thick. there, three superposed depositional units separated by erosional surfaces (fig. 3) can be observed. the three sequences show similar lateral and vertical depositional evolution and comparable calcareous lithofacies. 3.1 lithofacies of the bagnoli section conglomerates and sands: (figs. 4a,a1) the conglomerates are found exclusively at the base of the lower depositional unit (ldu). the subrounded calcareous pebbles mainly derive from the “calcare cavernoso” and ligurian lithologies. subordinate elements made of neogene sandstones and of boulder-size olistoliths of whitish laminated carbonates (fig. 4a2) can be locally observed. most of the grains are enveloped by a thin micritic coating. the abundant matrix is made of mixed sil iciclastic-carbonate silty sand that upwards forms decimetric tabular beds with planar lamination and normal grading, containing fossil remains of ostracods and gastropods. this lithofacies that upwards grades to chalky carbonates, is interpreted to represent the detrital channel infilling of the paleo-imbotroni creek. poorly layered, porous/chalky marly calcareous tufa: composed of irregular, centimetric layers of slightly coherent, porous peloidal mudstone (figs. 4b,c; 6a) with frequent remains of ostracods (fig. 6b) and gastropods. decimetre high phytohermal clusters and tufts (fig. 4d) built by cyanobacteria, or calcite-encrusted bryophytes and lenticular accumulations of calcified fragments of higher plants are irregularly associated. the phytoclastic facies that locally include abundant dissolution voids (fig. 6c), is composed of calcified casts of leaves and small branches. this lithotype representing former lime-muds colonized by bacterial/cyanobacterial mats and small mounds deposited in palustrine/lacustrine conditions is considered characteristic of the phytohermal/phytoclastic facies of 116 fig. 3 stratigraphic log of the foc succession at bagnoli. log stratigrafico del sintema foc presso bagnoli. e. capezzuoli, a. gandin & f. sandrelli 117 fig. 4 a) basal conglomerates and sands of the ldu; a1) detail of a) showing the fu gradation; a2) detail of a) showing a boulder of travertine with sinuous lamination; b) tabular detrital and calcareous tufa beds in the central portion of the ldu; c) planar laminae of the detrital facies alternated with chalky calcareous tufa with small phytohermal clusters; d) phytohermal clusters and phytoclastic lenses in the calcareous tufa. a) conglomerati e sabbie basali della ldu; a1) particolare della gradazione normale del deposito; a2) particolare dei blocchi di travertino laminato e ondulato; b) livelli tabulari detritici e carbonatici della porzione centrale della ldu; c) lamine piane della frazione detritica e intercalazione calcarea con piccoli cespugli fitoermali; d) cespugli fitoermali e lenti fitoclastiche nella facies calcarea. evidence of associated deposition ... the calcareous tufa (fo r d & pe d l e y, 1996; pe d l e y e t alii, 2003). regularly laminated crystalline travertine: consisting of centimetric laminae formed by dense, white calcite crystals perpendicular to the depositional surface. this lithofacies, distinctive of the laminated blocks enclosed in the basal conglomerate (fig. 4a2), can be referred to the "crystalline crust travertine" which, according to guo & riding (1998), is deposited on the slopes and cliffs of thermal systems reflecting rapid precipitation from fast flowing warm waters. regularly laminated bacterial/cyanobacterial travertine: made of centimetric laminae (figs. 5a,b,c,d) built by bacterial shrubs and peloidal aggregates (6d,e) 118 fig. 5 a) well bedded, whitish, laminated limestones of the upper part of the ldu; b) detail of the laminated limestone showing centimetric shrubs; c) detail of the laminated limestone showing the alternation between micritic and shrub laminae; d) the travertine laminae are locally cuspidate, probably reflecting a small paleomorphology; e) erosive surface between the ldu and the mdu enhanced by secondary karst dissolution; f) accumulation of fragments of thin crystalline calcite sheets (paper thin rafts). a) calcari laminati e ben stratificati della porzione superiore della ldu; b) particolare dei calcari laminati con gli shrub; c) particolare dei calcari laminati con l'alternanza di lamine con shrub ed altre micritiche; d) le lamine travertinose sono localmente cuspidate, probabilmente in corrispondenza di piccole morfologie; e) superfice erosiva fra ldu e mdu evidenziata dal carsismo; f) accumulo di frammenti di lamine di calcite cristallina (paper thin raft). e. capezzuoli, a. gandin & f. sandrelli lacking any trace of macrophytes or faunal elements (ostracods and gastropods). fragments of thin, millimetric crystalline calcite sheets corresponding to the paper-thin raft facies (figs. 5f; 6f) are locally found in subhorizontal accumulations associated with bacterially induced micritic mudstone. according to guo & ri d i n g (1998) and ch a f e t z & fo l k (1984) the brittle crystalline sheets of calcite form at the air/water interface of small pools of hot water and subsequently break and fall down at the bottom. bacterial/cyanobacterial aggregates, giving rise to the clotted fabric, develop within the micritic mud at the bottom of basins where high temperature, h2s o4 content, and low levels of oxygen prevent the life of higher vegetal and animal organisms. tabular laminae exclusively formed by bacterial “bushes” and mats, and the occurrence of paper-thin raft suggest the thermal origin of the laminated facies since “bacterial shrubs” and "shrub travertine" facies are known to form in pools or ponds and generally in stagnant/low energy shallow bodies of warm water (gu o & ri d i n g 1 9 9 8 ; chafetz & guidry 1999). 3.2 the depositional units lower depositional unit (ldu) (about 6 m thick) the base of the sequence, resting unconformably on the clays of the pliocene substrate, is represented by about 1,5 m of polymodal conglomerates including cobbleto boulder-size pebbles and sands in lenticular layers up to 30 cm thick. this conglomerate layer is sharply overlain by an alternation, about 2 m thick, of mixed fine sands and chalky marly calcareous tufa, that in turn is sharply overlain by about 2 m of well bedded, regularly laminated whitish, bacterial/cyanobacterial travertine. the ldu facies association can be interpreted to represent the evolution of an original fluvial system from the eroding stage to a palustrine/lacustrine cool-water environment resulting from the progradation of warm waters in pools fed from a thermal complex. this progression is documented by the basal coarse detrital facies derived from the neogene and pre-neogene substrates and the blocks of laminated crystalline travertine removed from more recent continental carbonates, and by the subsequent deposition of calcareous tufa, and of laminated bacterial/cyanobacterial travertine in the upper part of the unit. middle depositional unit (mdu) (about 9 m thick) it overlies the ldu with an irregular, apparently erosive contact, locally enhanced by local accumulations of residual rusty-red silt (fig. 5e). this unit consists of two carbonate intervals similar to those of the ldu. the lower one (max 1 m thick) is represented by well developed phytohermal/phytoclastic facies of calcareous 119 fig. 6 a) thin section of the marly peloidal mudstone (plain light, scale bar of 2 mm); b) section of an ostracod within the marly peloidal limestone of the calcareous tufa (plain light, scale bar of 2 mm ); c) twig-size elliptical sections (plain light scale bar of 2 mm); d) micritic shrub of the laminated limestone (plain light, scale bar of 1 mm); e) bacterial laminae (plain light scale bar of 2 mm); f) paper thin raft of crystalline calcite embedded in a peloidal matrix (plain light, scale bar of 2 mm). a) sezione sottile dei calcari marnosi peloidali (nicol paralleli, barra per scala: 2 mm); b) sezione di un ostracode all'interno dei calcari marnosi peloidali (nicol paralleli, barra per scala: 2 mm); c) cavità ellittiche di sottili steli (nicol paralleli, barra per scala: 2 mm); d) esempio di shrub micritico nei calcari laminati (nicol paralleli, barra per scala: 1 mm); e) lamine batteriali sovrapposte (nicol paralleli, barra per scala: 2 mm); f) sottile lamina cristallina (paper thin raft) immersa in matrice peloidale (nicol paralleli, barra per scala: 2 mm). evidence of associated deposition ... tufa that commonly fill small notches of the erosive basal surface. the transition to the overlying well-bedded travertine interval (about 8 m thick) is rapid. as in the ldu, it is dominantly represented by laminated bacterial/cyanobacterial facies but locally the paper-thin raft facies is found associated with micritic mudstone layers. the top of the mdu largely coincides with the flat surface of the terrace. it is covered by a rather thick brown soil. the facies associations, as in the underlying ldu, represent the evolution from the palustine/lacustrine conditions of a fluvial system (phytohermal/phytoclastic calcareous tufa) to the stagnant conditions in basins fed by a thermal system (laminated bacterial/cyanobacterial facies and paper-thin rafts). upper depositional unit (udu) -mainly exposed in the internal front of an abandoned quarry (fig. 7), it is represented by about 2 m of the poorly layered, porous/chalky marly calcareous tufa alternated with phytohermal/phytoclastic facies. this unit, preserved within a small gully cut in the upper part of the mdu, probably attests the beginning of a third cycle of carbonate deposition. 4. discussion the sedimentological and petrographic analysis of the carbonate facies cropping out at bagnoli in the imbotroni valley documents the inception of the carbonate deposition in the foc synthem. the succession rests on coarse-grained, high-energy fluviatile alluvial deposits (basal conglomerates) attesting a high-energy erosional event that incised the pliocene substrate. the occurrence within these conglomerates of carbonate boulders with an evident travertine fabric, support the hypothesis that they derive from the erosion of previous thermal deposits (probably a cone mound) that can be related to the earlier calcinaia sythem (cal) or to an older now eroded, synthem. the overlying carbonate succession is characterized by two (ldu and mdu), probably three (udu), depositional cycles consisting of the alternation of poorly bedded chalky calcareous tufa and well bedded crystalline, or dense laminated bacterial travertine. this alternation of calcareous tufa and travertine attests the repeated shifting of the environmental conditions probably caused by the intermittent activity of thermal 120 fig. 7 upper part of the foc succession in the abandoned quarry. contact between mdu and udu is enhanced. porzione superiore della successione foc nella cava abbandonata. viene evidenziato il contatto fra la mdu e la udu. fig. 8 schematic palaeoenvironmental reconstruction of the bagnoli spring (not in scale). ricostruzione schematica paleoambientale della sorgente di bagnoli (non in scala). e. capezzuoli, a. gandin & f. sandrelli spring/s. the carbonate-rich waters, flowing in the late pleistocene imbotroni valley, were probably mixed waters in part of meteoric/karstic origin, in part cooled waters derived from a thermal source located upstream and now covered by younger deposits. the thermal spring was building a small travertine depositional system, probably a mound cone (fig. 8). in the proximal terrace slope system (depression depositional system; gu o & ri d i n g 1998) thin bedded crystalline facies, well-bedded shrub facies cyanobacterial laminites and muds with paper-thin raft formed in shallow still-water ponds. these lithologies are indicative of the physico-chemical characteristics of the outflowing thermal water: the high temperature and encrusting capacity, the h2s o4 content and low levels of oxygen, all adverse to the development of higher vegetal and animal life. downstream from the warm water spring/s, calcareous tufa formed in the fluvial valley where a vegetated system with trees, bushes and grass could developed in small cool water ponds and marshes. this system was bounded by shal low barrages colonized by bryophytes and infilled by fine carbonate mud enclosing ostracods, gastropods, in situ small cyanobacterial tufts and/or encrusted fragments of the surrounding vegetation. the erosional surface between the ldu and the mdu may be related to a temporary dry up of the thermal spring, as a consequence of a fluctuation of the pluvial regime (dry period) and/or the obstruction of the thermal conduit. the assumption of the activity of thermal springs during the deposition of the calcareous successions of the quaternary synthems of southern valdelsa is supported by the present activity of few low-thermal resurgences in the area. one of them can be observed at bagnoli near the limestone outcrop described in this paper. the spring is characterized at present by a low water discharge (1 l/s) and temperature of 23°c. its encrusting capacity is now very reduced, limited to a thin carbonate coating forming only at the spring orifice (casagli et alii, 1990). other known springs are the vene di onci, consisting of several emergences with a mean discharge of 800 l/s and a temperature of 21°c and the caldane di 121 fig. 9 simplified geological scheme of the southern valdelsa basin. distinction between detrital and calcareous deposits of abb, cal, foc, bel synthems is evidenced. location of the active thermal springs (bagnoli, vene di onci, caldane di san marziale) supports the assumption that the origin of the calcareous deposits can be related to their presence. schema geologico semplificato della valdelsa meridionale. la posizione delle sorgenti termali attualmente attive (bagnoli, vene di onci, caldane di san marziale) conferma l'ipotesi della loro relazione con i depositi calcarei. evidence of associated deposition ... san marziale, near gracciano d'elsa, consisting of several pools which drain into the elsa river with a total low-flow of abut 80 l/s and a temperature of 22°c (casagli et alii, 1990) (fig. 9). the physical and geochemical features of these low thermal springs suggest that the superficial aquifer is fed by waters coming from the “calcare cavernoso” reservoir (casagli et alii, 1990; barazzuoli et alii, 2002). the slight thermalism of the springs can be related to the local geothermal gradient, which is about 57 °c/km (del chicca et alii, 1988). in all these springs water upwelling seems to be connected to fractures related to the local ne-sw apennine trending fault system, which connects the deeper circulating network with the upper aquifer (capezzuoli & sandrelli, 2006). the assumption that the origin of the continental carbonates of southern valdelsa basin can be related to the activity over time of these thermal springs appears to be supported by their areal distribution. in fact, as it happens for the small bagnoli spring, also the caldane di san marziale and vene di onci springs are located upstream of the segment of the elsa river valley where carbonates were deposited. it is possible to presume that all the pleistocene calcareous deposits occurring in southern valdelsa basin were connected with thermal springs that in part are now dried up or concealed/covered by the overlying calcareous tufa. 5. conclusion the results of a detailed analysis of the carbonates exposed at the bagnoli section provide an interpretation for the genesis and mutual relationships of the different facies and explain the peculiar areal distribution of the calcareous sediments in the late quaternary southern valdelsa basin. accordingly, the anomalous distribution of the calcareous sediments of these synthems can be related to the activity of thermal springs that yielded calcium carbonate-enriched water to the local streams thus supporting also the deposition of cool water continental carbonates. only in the proximity of the spring the physico-chemical proprieties of the water were ideal for the deposition of limestones with the characteristics of travertine. farther away carbonates with the typical features of calcareous tufa were deposited in the fluvial/palustrine system by mixed, cooled and meteoric waters as long as the carbonate concentration was sufficient for the encrusting process. terracing of these late quaternary deposits is the main indication that tectonic activity did play an important role in the sedimentation and erosion of the southern valdelsa synthems. this implication, only supposed by capezzuoli & sandrelli (2004; 2006), can be here confirmed owing to the recognition of the hot water-related lithofacies. in fact it is well known that faults and related fracture networks play a major role in channelling and upwelling of hydrothermal fluids (kerrich, 1986; curewitz & karson, 1997). for this reason, travertine bodies are considered good indicators of the activity of thermal springs and also of tensional tectonic activity (al t u n e l & ha nc o c k, 1993a,b; ha n c o c k et alii, 1999; at a b e y, 2002). consequently the age of faulting may be constrained by the age of travertine (al t u n e l, 2005; ha n c o c k et alii, 1999). in this case the recognition of the occurrence of travertine lithofacies in the apical part of the calcareous tufa bodies confirms the assumed (ca p e z z u o l i & sa ndrelli, 2006), late quaternary-holocene tensional tectonic activity in the valdelsa basin. acknowledgments we would like to thank paola tuccimei for critical reading of the manuscript and constructive suggestions. this work has been financially supported by the university of siena 2006 par grant (f. sandrelli). references altunel e. (2005) travertines: neotectonic indicators. in: ozkul m., yagiz s. & jones b. (eds). travertine, proceedings of 1s t international symposium on travertine, september 21-25, 2005, denizliturkey, 120-127, kozan ofset, ankara. al t u n e l e. & ha n c o c k p.l. (1993a) morphology and structural setting of quaternary travertines at pamukkale, turkey. geological journal, 2 8, 335346. altunel e. & hancock p.l. (1993b) active fissuring and faulting in quaternary travertines at pamukkale, western turkey. z.geomorph.nf, 94, 285-302. andrews j.e. (2006) palaeoclimatic records from stable isotopes in riverine tufas: synthesis and review. earth-science reviews, 75, 85-104. at a b e y e. (2002) the formation of fissure ridge type laminated travertine-tufa deposits microscopical cheacteristics and diagenesis, kir_ehir, central a n a t o l i a. bullettin of the mineral research and exploration, 123-124, 59-65. ba r a z z u o l i p., mo c e n n i b., ri g a t i r. & sa l l e o l i n i m . (2002) studio idrogeologico dei rapporti tra acque superficial i e profonde nel la zona di gracciano dell'elsa (prov. di siena). quaderni di geologia applicata, 9(2), 79-95. ba rma t t h e w s m., ay a l o n a. & ka u f m a n a.s. (1997) late quaternary paleoclimate in the eastern mediterranean region from stable isotope analyses of speleothems at soreq cave, israel. quaternary research, 47, 155-168. bartolini c. (2003) when did the northern apennine become a mountain chain? q u a t e r n a r y international, 101-102, 75-80. boccaletti m., bonini m., moratti m. & sani f. (1999) compressive neogene-quaternary tectonics in the hinterland area of the northern apennines. journal of pet. geol., 22, 37-60. bo s s i o a., co s t a n t i n i a., fo r e s i l.m., la z z a r o t t o a . , mazzanti r., liotta d., mazzei r., salvatorini g. & sandrelli f. (1995) studi preliminari sul sollevamento della toscana meridionale dopo il pliocene m e d i o. studi geol. camerti, volume speciale, 1995/1, 87-91. capezzuoli e., costantini e.a.c., priori s. & sandrelli f. (2007) stratigraphic aspects from the middle pleistocene continental deposits of the southern valdelsa basin. rendiconti della società geologica italiana, 5, nuova serie, 95-99. capezzuoli e. & gandin a. (2004) i “travertini” in italia: proposta di una nuova nomenclatura basata sui 122 e. capezzuoli, a. gandin & f. sandrelli caratteri genetici. il quaternario, 17(2/1), 273-284. capezzuoli e. & sandrelli f. (2004) i sedimenti quaternari del settore meridionale del la valdelsa (provincia di siena). il quaternario, 17(1), 33-40. ca p e z z u o l i e. & sa n d r e l l i f. (2006) neotectonic evidence in the quaternary continental carbonates from southern valdelsa basin (tuscany) . i l quaternario, 19(1), 155-166. carmignani l., decandia f.a., disperati l., fantozzi p.l., la z z a r o t t o, a., li o t t a d. & me c c h e r i m. (1994) tertiary extensional tectonics in tuscany (northern apenines, italy). tectonophisics, 238, 295-315. casagli n., duchi v. & pranzini g. (1990) low temperature thermal springs of col le val d'elsa (tuscany, central italy). memoires of the 22nd congress of iah, xxii, 635-644, losanna. chafetz h.s. & folk r.l. (1984) travertines: depositional morphology and the bacterially constructed constituents. j. sedim. petrol., 54, 289-316. ch a f e t z h.s. & gu i d r y s.a. (1999) bacterial shrubs, crystal shrubs, and ray-crystal shrubs: bacterial vs. abiotic precipitation. sedimentary geology, 1 2 6, 57-74. curewitz d. & karson j.a. (1997) structural settings of hydrothermal outflow: fracture permeability maintained by fault propagation and interaction. journal of volcanology and geothermal research, 79, 149-168. del chicca r., giorgi r., squarci p. & taffi l. (1988) sulle risorse geotermiche a medio-bassa temperatura nella parte meridionale del bacino neoautoctono della val d'elsa. studi preliminari: misure di gradiente. p.f.e. s.e.g., si-5, 563-571. dr y s d a l e r.n., za n c h e t t a g., he l l s t r o m j.c., fa l l i c k a.e., zh a o j., is o l a i. & br u s c h i g. (2004) paleoclimatic implications of the growth history and stable isotope (δ18o and δ13c) geochemistry of a middle to late pleistocene stalagmite from central-western italy. earth and planetary science letters, 227, 215-229. dw o r k i n s.i. , no r d t l. & at c h l e y s. (2005) determining terrestrial paleotemperature using the oxygen isotopic composition of pedogenic carbon a t e . earth and planetary science letters, 2 3 7, 56-68. ford t. d. & pedley h.m. (1996) a review of tufa and travertine deposits of the world. earth sci. rev., 41, 117-175. frank n., braum m., hambach u., mangini a. & wagner g. (2000) warm period growth of travertine during the last interglaciation in southern germany. quaternary research, 54, 38-48. ga n d i n a., gi a m e l l o m., gu a s p a r r i g., mu g n a i n i s. & sabatini g. (2000) the calcare cavernoso of the montagnola senese (siena, italy): mineralogicalpetrographic and petrogenetic features. miner. petrogr. acta, xliii, 271-289. garnett e.r., andrews j.e., preece r.c. & dennis p.f. (2004) climatic change recorded by stable isotopes and trace elements in a british holocene tufa. journal of quaternary science, 19, 251-262. gh e l a r d o n i r., gi a n n i n i e. & na r d i r. (1968) ricostruzione paleogeografica dei bacini neogenici e quaternari nella bassa valle dell'arno sulla base dei sondaggi e dei rilievi sismici. memorie della società geologica italiana, 7, 91-106. guo l. & riding r. (1998) hot-spring travertine facies and sequences, late pleistocene, rapolano terme, italy. sedimentology, 45, 163-180. ha n c o c k p.l., ch a l m e r s r.m.l., al t u n e l e. & ça k i r z . (1999) travitonics: using travertines in active fault studies. journal of structural geology, 2 1, 903-916. ke r r i c h r. (1986) fluid infiltration into fault zones: chemical , isotopic and mechanical effects. pageoph., 124, 225-268. koban c.g. & schweigert g. (1993) microbial origin of travertine fabrics two examples from southern germany (pleistocene stuttgart travertines and miocene riedöschingen travertine). facies, 2 9, 251-264. mckenzie j.a. & hollander d.j. (1993) oxygen-isotope records in recent carbonate sediments from lake greifen, switzerland (1750-1986): application of continental isotopic indicators for evaluation of changes in climate and atmospheric circulation p a t t e r n s . in: climate change in continental isotopic records (ed. by p.k. sw a r t, k.c. lo hm a n n, j. mckenzie and s. sa v i n), geophysical m o n o g r a p h , 7 8, 101-111, american geophisycal union. merla g. & bortolotti v. (1967) note illustrative della carta geologica d'italia alla scala 1:100.000. foglio 113 castelfiorentino. nuova tecnica grafica, roma. mi n i s s a l e a., pa l a d i n i m. & st u r c h i o n.c. (2005) travertine of central italy: relation between genesis, tectonics and paleoclimate. in: oz k u l m . , ya g i z s. & jo n e s b. (ed.): proceedings of i s t international symposium on travertine, 2125/09/2005, pamukkale university, denizli (tr), 106-115, kozan ofset, ankara. pedley m., gonzalèz martìn j.a., ordoñèz delgado s. & garcia del cura m.a. (2003) sedimentology of quaternary perched springline and paludal tufas: criter ia for recognition, with examples from guadalajara province, spain. sedimentology, 5 0, 23-44. pentecost a. (1995) the quaternary travertine deposits of europe and asia minor. quat. sci. rev., 1 4, 1005-1028. ri d i n g r. (1991) classi fication of microbial carbonates. in: riding r. (ed): calcareous algae and stromatolites. 21-51, springer-verlag. von grafenstein, u., eicher, u., erlenkeuser, h., ruch, p., sc h w a n d e r, j. & am m a n n, b. (2000) i s o t o p e signature of the younger dryas and two minor oscillations at gerzensee (switzerland): palaeoclimatic and palaeolimnologic interpretation based on bulk and biogenic carbonates. palaeogeography, palaeoclimatology, palaeoecology, 159, 215-229. 123 ms. ricevuto il 22 febbraio 2008 testo definitivo ricevuto il 19 marzo 2008 ms. received: february 22, 2008 final text received: march 19, 2008 evidence of associated deposition ... pag113_124 capezzuoli et al amq30(1) 3 pandolfi b.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 30 (1), 2017, 25 40 a reassessment of the infills and faunal assemblages of karst cavities known as ventarole in salento (apulia, southern italy): a multidisciplinary investigation on cava donno (corigliano d’otranto, lecce) luca pandolfi 1, marcello a. mannino2,3, sahra talamo3, leonardo salari4, paolo sansò5, sandro sublimi saponetti6, eligio vacca6, deborah vicari4, michael p. richards3,7, carmelo petronio4 1 dipartimento di scienze, sezione di geologia, università degli studi roma tre, roma, italy 2 department of archaeology, school of culture and society, aarhus university, højbjerg, denmark 3 department of human evolution, max planck institute for evolutionary anthropology, leipzig, germany 4 dipartimento di scienze della terra, università sapienza, roma, italy 5 dipartimento di scienze e tecnologie biologiche ed ambientali, università del salento, ecotekne, lecce, italy 6 dipartimento di biologia, università degli studi di bari, bari, italy 7 department of anthropology, university of british columbia, vancouver, canada corresponding author: l. pandolfi <luca.pandolfi@uniroma3.it > abstract: the karstic areas of apulia in se italy are characterized by fissures locally called ventarole, which are known to contain bones of pleistocene mammals. these bone assemblages have been commonly associated to the late pleistocene, based on stratigraphic, geomorphological and biochronological observations. we undertook palaeontological, radiocarbon and isotope analyses to verify whether the animal remains from the quarry of cava donno, near corigliano d’otranto (apulia), were all actually of pleistocene age. our study shows that the infills of the ventarole contain, along with late pleistocene bones attributable to the melpignano faunal unit, holocene vertebrate skeletal remains. the deeper red clay infill at cava donno contains fauna of pleistocene age, whilst the upper dark-reddish clayey sands contain mainly the bones of domestic animals and of a modern human. the ams radiocarbon date, obtained to establish the age of this human from the ventarola, coincides with the neolithic period. carbon and nitrogen isotope analyses on the same bone collagen suggest that the diet of this individual was similar to that of other neolithic humans from italy. the individual from cava donno had a balanced diet, centred upon terrestrial foods, with nutrients acquired both from vegetal and animal resources. the combined palaeontological, radiocarbon and isotopic data presented here suggest that crypto-solution processes occurred at cava donno both in the last interglacial and, to some extent, also around the holocene climatic optimum. this implies that ventarole karst infills may contain vertebrate remains of pleistocene and holocene age and that, therefore, the assemblages from them probably need revising because they may not all date back to the early late pleistocene. keywords: karst cavities; pleistocene; early holocene; neolithic; carbon and nitrogen isotope analyses 1. introduction the salento peninsula (apulia, southern italy) is well-known for the presence of karst cavities containing deposits that preserve rich paleontological and archaeological bone assemblages of pleistocene and holocene age (e.g., mirigliano, 1941; borzatti von löwenstern, 1966; palma di cesnola, 1966; spennato, 1981; de giuli, 1983; cremonesi et al., 1984; corridi, 1987; bologna et al., 1994; rustioni, 1998; vacca, 2006; petronio & pandolfi, 2008; benazzi et al., 2011; pandolfi & petronio, 2011; boscato & crezzini, 2012; pandolfi & tagliacozzo, 2013). this area represents, therefore, an important repository of invaluable data for reconstructing the evolution of past environments during the pleistocene and holocene in southern europe. abundant mammal remains have been recovered in different karstic features of the salento peninsula, such as in cave deposits (e.g., blanc, 1920, 1928; maviglia, 1955; orlandi & cigna, 1956; cardini, 1958a; borzatti von löwenstern, 1966, 1971; giusti, 1979; dantoni & nardi, 1980; campetti, 1986; boscato & crezzini, 2012), in stratified sediments at the bottom of dolines (corridi, 1987), and in sub-vertical or funnel-shaped fissures, locally known as ventarole, filled with reddish sediments (mirigliano, 1941; cardini, 1958b; de giuli, 1983; bologna et al., 1994; rustioni et al., 1994). the ventarole are located within the pietra leccese formation and outcrop in several quarries located in the districts of melpignano, corigliano d’otranto and maglie (lecce; fig. 1). most of the fossil mammal assemblages collected from the karstic fillings of the ventarole have been attributed to the early late pleistocene (bologna et al., 1994; bedetti et al. 2004; cipullo et al., 2006; petronio et al., 2007; petronio & pandolfi, 2008; pandolfi & petronio, 2011). these assemblages include skeletal remains of carnivores (panthera spelaea, crocuta crocuta, canis lupus), elephants (palaeoloxodon antiquus), rhinoceroses (stephanorhinus hemitoechus), horses (equus hydruntinus, equus ferus), hippopotamuses 26 pandolfi l. et al. (hippopotamus amphibius), bovids (bos primigenius, bison priscus), cervids (cervus elaphus, dama dama) and other taxa (mirigliano, 1941; cardini, 1958b; de giuli, 1983; bologna et al., 1994; bedetti et al., 2004; cipullo et al., 2006; petronio & pandolfi, 2008; pandolfi & petronio, 2011). during a paleontological field survey, several fossil remains belonging to oryctolagus cuniculus, lepus corsicanus, c. lupus, p. spelaea, c. crocuta, e. ferus, c. elaphus, d. dama and b. primigenius were collected from several karst fillings exposed at cava donno, a quarry near the town of corigliano d’otranto. in addition to some of the above-mentioned taxa, remains of domestic mammals and of homo sapiens were recovered from an n-shaped karst fissure. the cava donno ventarola investigated in this paper is characterized by red clayey infills in its sub-vertical cavities and by red clayey and dark reddish clayey sands in its oblique cavity (fig. 2). the late pleistocene and holocene mammal remains recovered from this n-shaped fissure are the object of the present paper. the aims of this study were: 1. to study the bone assemblage from cava donno in an attempt to understand its formation and relative chronology; 2. to undertake ams radiocarbon dating and isotope analyses on the bone collagen of the human individual whose remains were recovered from the ventarola to establish its absolute chronology and reconstruct its diet. moreover, the diachrony of the karst fillings from cava donno and from the districts of melpignano, corigliano d’otranto and maglie is discussed. fig. 1 a: location map of the investigated area; b: location map of the cava donno quarry and geological scheme of the s. sidero (melpignano) area. legend: a) calcarenites (lower pleistocene); b) leuca formation and sabbie di uggiano (pliocene); c) pietra leccese (upper miocene); d) calcari di altamura (upper cretaceus); e) fault slope; f) quarry; h) urbanized area; i) investigated area. fig. 2 n-shaped karst cavities of cava donno (melpignano, lecce). the arrows indicate the position of the humerus (1) and coxal bone (2) of homo sapiens. the white line indicates the dark reddish clayey sands that yielded the holocene fauna whilst the red line indicates the red clay with pleistocene fauna. 27 reassessment of the ventarole karst cavities 2. geomorphological and geological framework the landscape of the area between the presentday villages of corigliano d’otranto, melpignano and maglie in apulia is marked by a narrow morphostructural ridge stretching in a nw-se direction and bordered by two low steep scarps (fig. 1). this ridge characterizes the mean axis of southern salento from the area to the south of the village of botrugno to the nw of the village of corigliano d’otranto, where it reaches its maximum relief and acquires the local name of “serra di corigliano” (palmentola, 1987). rocks belonging to the pietra leccese formation (upper miocene) extensively crop out in correspondence to the morpho-structural ridge. they are biomicrites mainly constituted by calcareous plankton, generally yellowish in colour except in the uppermost levels which are greenish, because of the high glauconitic content. this lithostratigraphic unit is composed by indistinct thick strata and characterized by intense bioturbation, as well as by high macrofossil content, mainly of bivalves (above all pectinids) and echinoderms (spatangids). fossils are both dispersed and concentrated in lenses or layers; shark teeth are very frequent (largaiolli et al., 1969; balenzano et al., 2003). the unit is transgressive on the mesozoic basement (calcari di altamura formation, upper cretaceous) by means of a conglomerate layer marked by phosphatized clasts and fossils, as well as apatite nodules. the mesozoic limestones crop out in the northernmost area of the ridge, roughly from the village of corigliano d’otranto to the nw. the contact between mesozoic limestone and miocene calcarenites is well exposed along the salento manufatti s.r.l. quarry cliffs. the north-eastern border of the ridge, constituted by a degraded fault scarp, comprises at its foot a small outcrop of upper pliocene calcarenites belonging to the uggiano la chiesa formation (bossio et al., 1987). smaller outcrops of lower pliocene rocks (“formazione di leuca”), uplifted by faulting, can be recognized at the lowermost part of the scarp (fig. 3). above the ridge is a plain characterized by numerous quarries, given that upper miocene rocks are used for the production of blocks and slabs. sub-vertical karst cavities (i.e. ventarole), are present along the cliff sections of the quarry, infilled with reddish sandy-clayey deposits that cover the plain above the ridge. the transverse section of these cavities is still not well defined. the ventarole are spaced about ten meters from each other and reach depths of more than 10 m from soil surface. their maximum width is generally less than 1 m, although locally, cavities of up to 5-6 meters can be recognized. cavities become narrower downwards, terminating always in a joint plane (fig. 4). the strong structural control in the development of these landforms is testified by the morpho-structural analysis performed fig. 3 schematic geological section of the investigated area. legend: a) calcari di altamura (upper cretaceus); b) pietra leccese (upper miocene); c) leuca formation (lower pliocene); d) sabbie di uggiano (upper pliocene); e) fault; f) supposed fault. fig. 4 longitudinal section of the karst cavities (ventarole) recorded at cava donno (s. sidero, melpignano, lecce). fig. 5 azimuthal distribution of frequency of the ventarole outcropping at cava donno (s. sidero, melpignano). on three adjacent quarry cliffs (the area is marked by a bold circle in fig. 1). this analysis established that the ventarole developed mainly along nw-se and nnessw directions, following the main regional joint system (di bucci et al., 2011) (fig. 5). the karst cavities are completely filled by deeplyweathered dark-reddish clayey sands without definite sedimentary structures. in the wider cavities, reddish clayey sands are covered by less-weathered orange sands with a small clay content first and by greyish sands, about 1 m thick, further up the sequence. 3. materials and methods the human remains collected at cava donno (stored at the department of biology, university of bari) include an incomplete left humerus and an incomplete right os coxae. the morphometric values of the humerus and pelvis are reported in table 1. the methodology adopted follows martin & saller (1957-1962); additional measurements were obtained to estimate the length of the humerus and to evaluate the coxal bone proportions (see caption to table 1 for references). the faunal remains are currently housed at the dipartimento di scienze della terra, sapienza università di roma and are attributable to wild and domestic taxa. the remains were morphologically and morphometrically compared with several specimens from zoological and paleontological collections of the abovementioned department, in order to ascertain their taxonomic attribution. wild and domestic taxa belonging to the same genera (i.e., canis, equus and bos) were identified to species on morphological and morphometric basis, as well as on their conservation status. the specimens collected from the red clayey fillings are, in fact, well fossilized and encrusted with red-coloured soil, whereas the specimens collected from the dark-reddish clayey sands are not mineralized and are brown in colour. human and faunal remains from cava donno were sampled to establish the chronology and diet of the homo sapiens recovered at this site. bone collagen was extracted for this purpose using the pre-treatment method described by talamo & richards (2011), which includes an ultrafiltration step with sartorius “vivaspin 15” 30 kda ultrafilters. abbreviations: i, lower incisor; p, lower premolar; m, lower molar; la, articular width; dapolb, anteroposterior diameter of the oleocranon at the level of the beak; dapol, antero-posterior diameter of the oleocranon over the beak; ddt, distal transverse diameter; ddap, distal antero-posterior diameter; dpt, proximal transverse diameter; l, length; n, number of specimens. 4. palaeontological results and laboratory analyses 4.1. fossil remains from the red clay infill erinaceus europaeus this species is represented by a complete hemimandible with i1, p3, m2 and m3. oryctolagus cuniculus this species is represented by several cranial and postcranial remains. the morphology and morphometry of these remains are in agreement with the general features of the species reported by barone (1974, 1981), iacoangeli (1996) and angelci & spagnesi (2008). lepus corsicanus a fragmented femur, four ulnae, a fifth metatarsal and three fragmented mandibles can be referred to the hare. the anterior lower premolar (p3) does not display the crenulation on the posterior edge of the hypoflexid, which frequently occurs in l. europaeus. in addition, the crenulation on the internal side of the hypoconid in the studied specimens is absent, whereas a deep and oblique entrance on the internal side of the hypoconid can be present on p3 of l. europaeus. the paraflexid on the antero-lingual border is absent on the studied specimens as usually observed in l. corsicanus, whereas a deep paraflexid or parafosetid is usually present in l. europaeus (see palacios, 1996). the postcranial remains can also be assigned to l. corsicanus. microtus (terricola) savii this small rodent is represented by five hemimandibles. the first lower molar on these specimens displays seven triangles, the fourth and the fifth of them are confluent to form the pitymyan rhombus (see nappi & contoli, 2008, and references therein). tab. 1 morphometric values of the human remains from cava donno (melpignano, lecce). *martin and saller, 1957-1962; **estimate (salles et al., 2009); ism: ischium length, modified (novotny, 1986); ismm: ischium length, post-acetabular (schulter-ellis et al., 1983); ss, sa: spino-sciatic and spinoauricular lengths (gaillard 1960); ^cotylo-sciatic index (sauter & privat, 1955). 28 pandolfi l. et al. canis lupus two lumbar vertebrae, a proximal epiphysis of ulna, a first phalanx and an upper canine can be assigned to c. lupus. the remains are large in size, in particular the ulna (la = 22.4 mm; dapolb = 31.3 mm; dapol = 28.2 mm). the morphometry of the ulna and the presence of a strong muscular impression suggest that this specimen is slightly larger than the extant c. lupus from the abruzzi region (salari, unpublished data). equus ferus the following remains are assigned to this taxon: a distal epiphysis of humerus (ddt = 82.1 mm; ddap = 90.0 mm), a first posterior phalanx (la = 89.5 mm; dpt = 58.5 mm; ddt = 49 mm), two fragments of second and fourth vestigial metapodials and a lower deciduous tooth. the morphology and morphometry of these remains resemble those of the equid from tana delle iene (brindisi, southern italy), which is late pleistocene in age (conti et al., 2010). bos primigenius a first upper molar (l = 32; la = 26), which displays a wide and developed entostyle (sala, 1986), and a large first phalanx are referred to the aurochs. cervidae indeterminate cervidae is represented only by a thoracic vertebra of a young individual and an attribution to red deer rather than fallow deer is not possible. 4.2. fossil remains from the dark-reddish clayey sands homo sapiens: humerus this humerus lacks the proximal portion, including the articular head and the surgical neck. the metaphyse preserves part of the bicipital groove and the crests of the greater and lesser tubercles (fig. 6). the residual length of the humerus is of approximately 246 mm. the bone has been reconstructed from two corresponding fragments broken distally to the middle of the shaft. the distal epiphysis is complete, yet slightly damaged on the distal articular surfaces. the estimated length of the humerus (m1) was calculated from the regression, as proposed by salles et al. (2009) on the basis of a recent sex-aggregated sample of adult individuals belonging to various populations. an estimated value of 296.6 mm (±13.5 mm) was obtained from the average values of three different regressions (fig. 7). the method proposed by steele (1970) fig. 6 homo sapiens from cava donno (melpignano, lecce), humerus in anterior (a), posterior (b), lateral (c) and medial (d) views. 29 reassessment of the ventarole karst cavities allowed us to obtain estimated values of between 295.7 and 298.2 mm. a mean value of 282.6 mm was reported by formicola & franceschi (1996) for a neolithic european sample of 27 females (fig. 7). these values do not differ significantly (t-test, p = 0.200) from the mean values obtained for a recent apulian female sample (287 mm ±16.4 mm, n = 40; introna et al., 1994). three sexually dimorphic features of the posterior distal humerus were evaluated (rogers, 1999). the trochlear constriction is intermediate, but the shape of the trochlea tends to be symmetrical with the margin of the capitulum. the shape of the olecranon fossa is oval and the medial epicondyle is angled. taking these features into account, the cava donno humerus could be assigned to a category of “probable female” (falys et al., 2005). considering morphometric values, the last circumference of the shaft (m7 = 52.0 mm) falls within the dimensional range of female individuals from neolithic apulia (fabbri & lonoce, 2011). a discriminant function, calibrated on a recent apulian population (f.n. 10; 90% correctly classified), places the specimen from cava donno within the area occupied by female individuals, thus classifying the humerus as female (introna et al., 1994). two female humeri from malerba (mlt2a, mlt2b, scattarella et al., 1997, 2001) and a male humerus from cala colombo (cc17, pesce delfino et al., 1977) are correctly assigned to gender, based on the discriminant function analysis performed for the specimens from cava donno, in agreement with their morphological features. it is well-known that comparisons between modern and ancient human remains, of which little is known on sexual dimorphism, may be inadequate; such comparisons, hence, represent mere evaluations relative to the modern variability. the stature was estimated based on the method proposed by formicola & franceschi (1996). the values obtained are 154.7 cm for the least squares and 155.8 cm for the major axis formulae respectively. similar values (156 cm) are obtained using the methods of sjøvold (1990) and trotter & gleser (1952, 1977; 156 cm, black females). figure 7 shows the estimated heights for some female individuals from neolithic apulia compared with those of cava donno (humerus least square equation; formicola and franceschi, 1996). according to formicola (1983, 1989), the estimated stature for the neolithic italian sample spans between 148 and 156 cm, whereas the estimated stat ure for ligurian female samples (8 individuals) has an average value of 150.6 cm. an average value of 151.4 cm (± 2.94 cm) was reported for a sample of 11 female individuals from the central apulian area (barbieri et al., in press). the estimated stature for the cava donno specimen is relatively low compared with recent populations (martin & saller, 1957-1962), but relatively high compared with the neolithic sample. the age at death, referable to approximately the fourth decade, is derived from the absence of any residual epiphyseal fusion line, as well as from the presence of moderate signs of lipping on the articular surfaces. the proximal third appears laterally curved in the anterior view, the convexity being accentuated by the attachment of the pectoralis major. the midshaft section of the diaphysis is flattened mediolaterally. according to the robusticity index (m7/1 = 17.2), the bone is relatively gracile, but the attachment of the pectoralis major is hypertrophic, robust and bounded by light, but well defined, radiating lines (mariotti et al., 2007); furthermore, the insertion for the brachioradialis muscle is well expressed. the attachment for the deltoid is, instead, less well-defined, with the surface wrinkled and uneven. this profile may indicate activities requiring considerable involvement of the shoulder joint or intense manipulation. the cross-section index of the shaft demonstrates eurybrachia near the platybrachia (m6/5=77.0). for two female individuals from serra cicora (t6b, t10a) a eurybrachic index is reported (fabbri & lonoce, 2011); eurybrachia is also recorded for passo di corvo (facchini, 1983) and for four female humeri from central apulia (barbieri et al., in press). differences in lifestyles and nutritional deficiencies, especially in early childhood, affect the bone mass and cortical bone thickness. for these reasons, in the long bones, the development of the cortex of the shaft is a reliable indicator of nutritional status (larsen, 1999). in cava donno, the percentage of the cortical area (ca = 79.7%) is higher than the mean values reported for 11 neolithic females from central apulia (69.5 ± 7.9) (barbieri et al., in press). the crosssectional moments of inertia, proportional to the bending rigidity of the bone in the sagittal and medio-lateral planes, are instead among the lowest (imax=4316: imin=1754). in the cava donno humerus, therefore, a relatively low degree of biomechanical stress is associfig. 7 stature (in cm) obtained from the length of the humerus from cava donno (cdonno) and comparison with several neolithic females from central and southern apulia (serra cicora (sct6b, sct10a; fabbri & lonoce 2011); malerba (mat2a, mat2b); polignano madonna di grottole (pmgr; scattarella & de lucia, 1988); palagiano (pal7b, barbieri et al., in press), with a sample of european neolithic females (neoff, formicola e franceschi 1996: mean ±1sd) and with a recent apulian sample (prec, introna et al. 1994; mean ±1sd). 30 pandolfi l. et al. ated with a balanced nutrition (as discussed below). homo sapiens: coxal bone the hipbone lacks the pubis, from the ramus superior to the anterior border of the acetabulum, and from the ramus inferior to the ischial tuberosity (fig. 8). the bone has been reconstructed from two large fragments which include the ilium and part of the ischium with a relatively complete acetabular cavity. two small fragments, one of the ischial tuberosity and one of the iliac spine, also belong to the same specimen. as with the humerus, the hipbone is also reddish-brown and partially covered by soil residues. the bone is relatively short, the maximal height (182.8 mm) falls within the range of the modern apulian female sample, but is considerably smaller than the mean value of the same sample (193.2 ± 8.6, n = 63) (vacca & di vella, 2012). the iliac width (151.0 mm) is comparable, instead, with the average value of the same population (152.4 mm ± 6.5, n = 57). the sigmoid curvature of the iliac crest is rather weak, the iliac fossa is moderately concave and the gluteal lines poorly marked. the muscle attachments on the ischial tuberosity are well defined, the bone surface appears finely wrinkled in relation to the flexion of the leg on the thigh. the iliac tuberosity is well developed and elevated with respect to the auricular facet, a marked post-auricular sulcus separates the two features; on the margin of the facet, moderate lippings of osteophytes can be observed. interosseous groove and iliac tuberosity play an important role in maintaining the stability of the pelvic girdle (andersen, 1986), it is therefore possible that these structures relate to sacroiliac ligament stress and strain. the coxal bone displays at least three morphological characteristics that suggest attribution to a female individual: preauricular sulcus, a composite arch and the form of the sciatic notch. the notch is wide, the anterior and posterior part diverging with a certain degree of asymmetry, yet without recursivity of the posterior ramus. the posterior ramus, normally shorter than the anterior, is instead longer. it is possible that this configuration is due to the same biomechanical stresses discussed in relation to iliac tuberosity and interosseous groove. the cotylo-sciatic index (m15.1/14.1 = 136.4) is comparable with the average values obtained from the recent apulian sample cited above (134.5 ±11.2, n = 82). two discriminant functions calibrated on the same sample (f.n. 7 and 8; vacca & di vella, 2012), suggest that the specimen from cava donno is a female. by fig. 8 homo sapiens from cava donno (melpignano, lecce), coxal bone in lateral (a) and medial (b) views. 31 reassessment of the ventarole karst cavities using the same functions, two coxal bones from malerba (mlt1, male; mt2b, female) are correctly assigned to gender, in agreement with their morphological characteristics. the equations defined by murail et al. (2005) for a worldwide hipbone metrical database also classify cava donno as female (pf ≥0.95). the age at death was estimated from auricular surface morphology: the transverse organization is almost absent, the bone surface has micro and macroporosity and slight retroauricular and apical activity is present. this configuration leads to an estimate of age at death at least in the fourth decade of life (lovejoy et al., 1985). the stature was estimated based on the height of the coxal bones and the diameter of the articular head of the femur (36.8 mm). the latter was obtained from the diameter of the acetabulum and considering the linear regression, as reported by giroux & wescott (2008) and holliday (2000). the values obtained, 153.2 cm (white female) and 153.9 cm (black female), are comparable with those estimated for the humerus of cava donno. based on the femoral head diameter, a body mass of 48.7 kg is estimated for cava donno (ruff et al., 1991). an average value of 55.7 kg (±5.1) (barbieri et al., in press) was obtained for 6 neolithic female individuals from central apulia. microtus (t.) savii this taxon is represented by a hemimandible and a few cranial remains with the third upper molar in simplex morphology (see nappi & contoli, 2008 and references therein). canis sp. a cervical vertebra of a young individual and a fragmented thoracic vertebra can be assigned to this genus. unfortunately, the morphology and morphometry of these specimens are not useful to distinguish between a medium-sized wolf and a domestic dog. bos taurus the morphometric values of an almost complete calcaneum (l = ca. 140 mm) fall within the dimensional range of the neolithic domestic cattle from central and southern italy (wilkens, 1987, 2003). a fragment of horn probably belonging to a female individual, a fragment of skull with the tympanic region, a cervical vertebra, a cuneiform, a sesamoid and a proximal fragment of rib can also be attributed to b. taurus. ovis aries vel capra hircus a few cranial and postcranial remains can be generally referred to ovis vel capra. based on boessnek (1969), barone (1978, 1981) and gudea & stan (2012), a relatively hypsodont third upper molar, a fragmented pelvis and a distal epiphysis of tibia can be attributed to ovis aries (sheep), whereas an almost complete humerus can be referred to capra hircus (goat). 4.3. isotope analyses and radiocarbon dating on bone collagen the human coxal bone sampled for this study yielded an extract that, based on the quality criteria proposed by van klinken (1999), is well-preserved collagen (tab. 2). this extract was ams radiocarbon dated to 6216 ± 23 14c bp (at 95.4% of confidence: 7250-7010 tab. 2 carbon (δ13c) and nitrogen (δ15n) isotope values of bone collagen extracted from human and faunal samples recovered at cava donno. tab. 3 ams radiocarbon date on bone collagen of the human from cava donno, pretreated at the max planck institute for evolutionary anthropology (leipzig). the date was performed at the klaus tschira laboratory of the curt-engelhorn-zentrum archaeometrie in mannheim (mams) and calibrated with the oxcal 4.2 software (bronk ramsey & lee, 2013), using the intcal13 curve (reimer et al., 2013). 32 pandolfi l. et al. animals that feed on these will have higher δ15n values than those grazing in nearby unmanured fields (bogaard et al., 2013). the humans from passo di corvo also have high δ15n values (= 13.3‰), confirming that they fed on plants and/or meat affected by manuring, in the context of a densely populated village the occupants of which were intensively exploiting the landscape around the settlement. this does not appear to have been the case of the human from cava donno, who has an isotopic composition more in line with that of most other neolithic sites in apulia, as well as further afield in the italian peninsula (e.g. giorgi et al., 2005; lelli et al., 2012; goude et al., 2014). 5. discussion 5.1. geomorphological evolution of the karst cavities ventarole are karst landforms that developed along main joints affecting the carbonatic bedrock, because of intense karst processes that occurred below soil cover (crypto-solution processes). these cavities formed mainly in the upper miocene calcarenites of the pietra leccese formation during the late pleistocene, as clearly indicated by fossil fauna. karst landforms due to crypto-solution sharing the same age of ventarole have been recognized in other areas of the salento peninsula (marsico et al., 2003; leucci et al., 2005). in these last cases, solution pipes of cylindrical shape formed because of the isotropy of carbonatic bedrock; pipes are up to 2 m deep and have a diameter length between 0.5 and 1 m. the development of ventarole has been strongly influenced by jointing of miocene carbonatic rocks, so that crypto-solution processes produced the widening of joints forming narrow cavities lengthened downwards. in the scientific literature crypto-solution cavities developed along joints are defined cutters (howard, 1963; palmer, 2009); they have been well studied in indiana (usa), where they are exposed along the quarry cliffs cut into the salem limestone (early carboniferous). the widening of the ventarole causes slow sinking of loose superficial soils, along with fossil remains present inside; these processes turn ventarole into sedimentary traps. 5.2. anthropological and archaeological considerations the biological profile of the human remains from cava donno, represented by a fragmented left humerus and a fragmented right coxal bone, suggest that these two specimens probably belonged to the same individual. this individual was a relatively gracile adult female, of medium stature for the neolithic period, yet with a good level of muscular activity. on the basis of the general features of these human remains and of the comparative data, the bones from cava donno fall within the variability of the neolithic populations of southern italy, similarly to other apulian samples. the lack of artifacts in the infill does not allow us to say more about the cultural attribution and archaeology of the adult female from cava donno. calibrated years bp or 5300-5060 calibrated years bc; tab. 3), a time coinciding with the middle neolithic in apulia (malone, 2003; quarta et al., 2005). of the 11 animal bones sampled, 6 did not yield extracts due to poor preservation. the latter samples are from late pleistocene fauna (i.e. the wolf canis lupus and the auroch bos primigenius), as well as equids and lagomorphs that may also be of similar age. the remaining 5 samples have %c, %n, c:n ratio and % yields (tab. 2) falling within the range for good quality collagen (van klinken, 1999). the δ13c values of the fauna from the site are typical of animals living in terrestrial habitats dominated by c3 plants (mean = -20.4 ± 0.1‰), such as those of the northern mediterranean before the introduction of agriculture (e.g. mannino et al., 2012, 2015). the δ15n values of the large herbivores (i.e. bos taurus and equus ferus) are compatible with those of animals living in temperate environments and of the majority of analyzed domestic fauna from neolithic sites in apulia (e.g. lelli et al., 2012; tafuri et al., 2014). the microtus specimen, on the other hand, lived at a time when the δ15n baseline was relatively high, which likely indicates that this animal was contemporary to a more arid phase than the earlyto-mid holocene. the δ13c value of the human bone collagen indicates that the diet of this individual was based on the consumption of terrestrial dietary protein from c3 plant dominated environments. the δ15n ratio falls within the range of such values obtained for neolithic humans from apulia and the italian peninsula. had the bovids and equids for which we have isotopic data been contemporary to the human specimen analyzed (which is likely given their overlap with values from similar animals from neolithic apulian sites), it could be suggested that this individual had a mixed diet with regular consumption of meat, because its δ15n ratio is ~3.3‰ higher than the mean of the herbivores (= 6.4 ± 0.9‰). however, given the mixed nature of the context of recovery, without dating of each bone we cannot be sure of their exact chronology. for this reason, we compared the isotope values of the human from cava donno with neolithic humans and fauna from apulia (lelli et al., 2012; tafuri et al., 2014). the herbivores from grotta della mura (δ13c = -20.2‰; δ15n = 5.9‰), masseria candelaro (δ13c = -21.1‰; δ15n = 6.3‰) and grotta scaloria (δ13c = -19.9‰; δ15n = 6.0‰), as well as from areas of apulia such as the tavoliere (δ13c = -20.6‰; δ15n = 7.5‰) and the murge (δ13c = -19.9‰; δ15n = 6.9‰), have isotopic compositions similar to those from cava donno (δ13c = -20.4‰; δ15n = 6.4‰). the only neolithic fauna from apulia with a different isotope composition to that of the animals from cava donno and other contemporary sites is that from passo di corvo (tafuri et al., 2014). domestic fauna from this ditched village have mean δ13c ratios of -19.7‰ and mean δ15n ratios of 10.2‰. the nitrogen isotope values of the domesticates from passo di corvo are far higher than those from any other site in se italy and likely a consequence of feeding on plants from manured fields. manuring produces enrichments in the nitrogen isotope composition of intensively-manured plants and, in turn, 33 reassessment of the ventarole karst cavities nevertheless, the radiocarbondate, obtained as part of this study, suggests that the area of cava donno was occupied at least during the middle neolithic, in line with contemporary evidence for intense human occupation in the salento area at sites such as serra cicora, samari, grotta parabita and grotta della trinità (cremonesi, 1978, 1985-86; ingravallo, 1997; quarta et al., 2005; tiberi, 2011; dolfini, 2015). 5.3. palaeontological considerations the mammal assemblages from the ventarole of the study area are known since the nineteenth century (mirigliano, 1941; cardini, 1958b). the vertebrate remains are generally in a good state of preservation and are located at the base and at the top of these karstic infills, without signs of long-distance transport (bologna et al., 1994). in addition, remains are chaotically scattered within these features, lacking specific taphonomic signatures or traces of human activity, and sometimes parts of the same skeletal element occur at different depths (de giuli, 1983; bologna et al., 1994). ventarole karst infills probably accumulated rapidly and the mammalian bone assemblages within them usually appear as coeval in age (bologna et al., 1994). in the first half of the 20th century, several mammalian bone assemblages from different karst cavities in the melpignano area were collected and described by mirigliano (1941) (tab. 4). the presence of several fossiliferous karst infills in the pietra leccese quarries was later also reported by cardini (1958b). however, some of the species reported by cardini (1958b; tab. 4) were recorded in one or a few cavities (e.g., hippopotamus was only recorded at cava motta). de giuli (1983) later described a rich mammalian bone assemblage recovered from a single cavity near maglie at the quarry ‘cava l’, known as san sidero 3 (tab. 4). bologna et al. (1994) described several vertebrate remains, including a tooth of homo cf. neanderthalensis, collected in different ventarole from cava nuzzo near melpignano (tab. 4). the mammal assemblage from cava nuzzo was stratigraphically correlated by bologna et al. (1994) with the fossiliferous levels above the euthyrrenian deposits of several caves along the salento coast (e.g., grotta romanelli, grotta del cavallo, grotta delle striare) and chronologically attributed to the mis 5c-5a, based on stratigraphic, geomorphological and biochronological evidence. in addition, other mammalian assemblages such as those recovered from the districts of melpignano, corigliano d’otranto and maglie, reported by de giuli (1983) and corridi (1987), and those from ossiferous breccias cropping out between 0 and 10 m a.s.l. along the southeastern coast of salento peninsula, from castro marina to otranto (di stefano et al., 1992), were chronologically correlated with mis 5c-5a by bologna et al. (1994). more recently, petronio et al. (2007) established the faunal unit (fu) of melpignano as a new italian biochronological unit for the late pleistocene and proposed the mammal assemblage from cava nuzzo as a local faunal type. the new fu included the classic late pleistocene warm-adapted mammal fauna auctorum, and likely dated back to between ca. 100 and 70 ka (then from 120 to 80 ka; see petronio et al., 2011; pandolfi et al., 2013). the melpignano fu was characterized by the first occurrence of cervus elaphus and dama dama with “evolved” antler morphology, the persistence of large-sized mammals, such as p. antiquus, s. hemitoechus and h. amphibius, and the absence of mammuthus primigenius, coelodonta antiquitatis and other typical cold-adapted mammals auctorum, which defined a new subsequent late pleistocene faunal unit, the ingarano fu (petronio et al., 2007, 2011). in addition, based on the considerations by bologna et al. (1994) and petronio et al. (2007), some authors have also attributed to the early late pleistocene several bird and mammal assemblages from different ventarole at ‘cava l’ near maglie (bedetti et al., 2004) and several fossil remains of carnivores (cipullo et al., 2006), horses (conti et al., 2010) and rhinoceroses (petronio & pandolfi, 2008; pandolfi & petronio, 2011) collected in ventarole from the pietra leccese quarries of the melpignano, corigliano d’otranto and maglie area. in the n-shaped cavity at cava donno, however, the presence of two different faunal associations referable to two distinct epochs (i.e. late pleistocene and holocene) suggest that the mammal assemblages from different karst cavities may not be coeval. in the case of the cavity at cava donno, taxa collected from the red clay deposits (i.e., erinaceus europaeus, oryctolagus cuniculus, lepus corsicanus, microtus (t.) savii, canis lupus, equus ferus, bos primigenius) are in all likelihood older than those collected with the human specimens. a late pleistocene age is suggested for the former taxa, although there is no data to propose a more detailed chronological attribution. the presence of holocene fauna, however, is documented by the occurrence of domestic mammals and, importantly, by the ams radiocarbon date obtained from the human coxal bone (72507010 calibrated years bp). the carbon and nitrogen isotope data from this human specimen fall within the variability recorded for neolithic humans from apulia and italy, suggesting (as discussed above) that the individual in question obtained most of her dietary protein from terrestrial sources that included both vegetal and animal foodstuffs. in addition, the isotopic composition of the well-preserved bone collagen from the fauna, analyzed as part of the present study, is very similar to that of specimens analyzed to date from apulia. this is a further clue that a significant proportion of the vertebrate assemblage from cava donno dates to the holocene. nevertheless, if most of the karst fissures in question were generated and filled with sediments rapidly between the last interglacial (mis 5e) and the early phases of the subsequent climatic deterioration (mis 5c5a, or perhaps up to the beginning of mis 4), we cannot exclude that other cavities in the salento area were also filled during different stages of the late pleistocene. this is probably the case, for instance, of a ventarola at the pietra leccese quarry near sternatia (tab. 4), a locality a few kilometers north of cava donno, the mammal bone assemblage from which was attributed by rustioni et al. (1994) to the second part of mis 4 or to mis 3. 34 pandolfi l. et al. tab. 4 late pleistocene mammalian taxa recorded from the ventarole karst infill discussed in the text. the taxonomy of the recorded species is updated according to several published papers (among others: trocchi & riga, 2005; petronio & pandolfi, 2008; conti et al., 2010; pandolfi & petronio, 2011; petronio et al., 2011; marra et al., 2014; sardella et al., 2014; pandolfi & tagliacozzo, 2015; pandolfi & marra, 2015). 35 reassessment of the ventarole karst cavities 6. conclusions the occurrence of fossil remains belonging to late pleistocene vertebrates suggests that crypto-solution processes at cava donno and in the surrounding area were probably promoted by humid-warm climatic conditions that affected the salento peninsula during the last interglacial period. moreover, the presence of neolithic fauna (attested by this study) could indicate a weak reactivation of crypto-solution processes during the holocene climatic optimum. this likely caused the sinking of the soil cover, constituted by greyish continental deposits that were present at the top of larger ventarole. the presence of holocene and pleistocene mammals in the n-shaped karst fissure from the pietra leccese quarry of cava donno suggests that a critical revision of the chronology of the different bone assemblages recovered within the sediments filling the ventarole scattered throughout the districts of melpignano, corigliano d’otranto and maglie should be undertaken. some fossiliferous deposits could be referred to the early late pleistocene, however, some others could indeed be younger in age. we, therefore, suggest to attribute to the melpignano fu, proposed by petronio et al. (2007), only those deposits that yielded a welldefined association which are analogous in faunal composition and, ideally, abundances with the mammal assemblage of cava nuzzo (e.g., san sidero 3, cava motta). all faunal associations that are not based on mammals useful for establishing biochronological constraints should, therefore, be revised and supported by the application of radiometric dating. an additional outcome of the present study was to obtain carbon and nitrogen isotope data on bone collagen, useful to reconstruct the diet of the neolithic human whose remains were recovered at cava donno. in the absence of information on the settlement and local subsistence economy of the group to whom the individual from cava donno belonged, we can only reach broad conclusions with the data at hand. firstly, we can conclude that neolithic people either intentionally, or not, left traces of their presence at sites such as cava donno. secondly, interpreting the isotope data obtained as part of our study in the context of the database currently available from italian sites, we suggest that the individual from cava donno had a similar diet to that of most of her contemporaries from across italy. the dietary protein consumed by this individual originated overwhelmingly, if not exclusively, from terrestrial sources and both from animals and plants. with the data presented here, we cannot say much more about the proportion of plant to meat consumed. however, given the relatively high δ15n value, it is possible that animal protein acquired by consuming meat and/or dairy products were an important component of the diet of the neolithic human from cava donno. acknowledgements m.a.m., s.t. and m.p.r. thank the max planck society for funding the ams radiocarbon date and the isotope analyses. thanks are due to prof. jean-jacques hublin, director of the department of human evolution, for supporting these analyses and to sven steinbrenner, annabell reiner and lysann rädisch for invaluable technical assistance. we thank the editor a. sposato and the reviewers v. codrea and m. f. rolfo for useful suggestions and comments. references andersen b.c. (1986) parturition scarring as a consequence of flexible pelvic architecture. phd thesis, department of archaeology, simon fraser university, canada. angelici f.m., spagnesi m. (2008) oryctolagus cuniculus (linnaeus, 1758). in: amori g., contoli l. & nappi a. (eds.), fauna d’italia, mammalia ii, erinaceomorpha, soricomorpha, lagomorpha, rodentia, calderini de il sole 24 ore, milano, 292-302. balenzano f., margiotta s., moresi m. (2003) significato di un deposito glauconitico-fosfatico appartenente ad una unità miocenica del salento (puglia). atti della società toscana di scienze naturali, mem., s.a, 108, 7-21. barbieri a., bertini e., de nicola l., panzarino g., sublimi saponetti s. (in press) studio antropologico delle antiche comunità di agricoltori del neolitico pugliese: ricostruzione del modus vivendi e temporal trend delle condizioni nutrizionali, lavorative e di mobilità territoriale. in: atti della xlvii riunione iipp: preistoria e protostoria della puglia, coppola d. (ed.), ostuni 9-13 ottobre 2012. barone r. (1974) anatomia comparata dei mammiferi domestici. 1, osteologia (edizione italiana a cura di bortolami r.), edagricole, bologna. barone r. (1981) anatomia comparata degli mammiferi domestici. 3, splancnologia. (edizione italiana a cura di bortolami r.), edagricole, bologna. bedetti c., pavia m., sardella r. (2004) nuovi dati sull'associazione a vertebrati fossili del pleistocene superiore di san sidero, maglie (puglia, se italia). iv giornate di paleontologia (2004), 21-23 maggio 2004, bolzano, 12. benazzi s., douka k., fornai c., bauer c.c., kullmer o., svoboda j., pap i., mallegni f., bayle p., coquerelle m., condemi s., ronchitelli a., harvati k., weber g.w. (2011) early dispersal of modern humans in europe and implications for neanderthal behaviour. nature, 479, 525-528. blanc g.a. (1920) grotta romanelli. i stratigrafia dei depositi e natura e origine di essi. archivio per l’antropologia e l’etnologia, 50, 64-103. blanc g.a. (1928) grotta romanelli. ii dati ecologici e paletnologici. archivio per l’antropologia e l’etnologia, 58, 365-411. boessneck j. (1969) osteological differences between sheep (ovis aries linné) and goat (capra hircus linné). in: brothwell d. & higgs e. (eds.), science in archaeology, thames and hudson, london, 331 -358. bogaard a., fraser r., heaton t.h.e., wallace m., vaiglova p., charles m., jones g., evershed r.p., styring a.k., anderson n.h., arbogast r.m., bartosiewicz l., gardeisen a., kastrup m., maier u., marinova e., ninov l., schäfer m., stephan e. 36 pandolfi l. et al. (2013) crop manuring and intensive land management by europe’s first farmers. proceedings of the national academy of sciences of the usa, 110, 12589-12594. bologna p., di stefano g., manzi g., petronio c., sardella r., squazzini e. (1994) late pleistocene mammals from the melpignano (le) «ventarole»: preliminary analysis and correlations. bollettino della società paleontologica italiana, 33 (2), 265-274. borzatti von löwenstern e. (1966) alcuni aspetti del musteriano nel salento. rivista di scienze preistoriche, 21, 1-31. borzatti von löwenstern e. (1971) seconda campagna di scavi nella grotta “mario bernardini” (nardò lecce). rivista di scienze preistoriche, 26, 31-92. boscato p., crezzini j. (2012) middle-upper palaeolithic transition in southern italy: uluzzian macromammals from grotta del cavallo (apulia). quaternary international, 252, 90-98. bossio a., guelfi f., mazzei r., monteforti b., salvatorini g., varola a. (1987) precisazioni sull’età dei sedimenti pleistocenici di due cave del leccese (san pietro in lama e cutrofiano). quaderni ricerche centro studi geotecnica e ingegneria di lecce, 11, 147-174. bronk ramsey c., lee s. (2013) recent and planned developments of the program oxcal. radiocarbon, 55, 720-730. campetti s. (1986) il musteriano della grotta di serra cicora a nell’ambito dell’evoluzione del paleolitico nel salento. studi per l’ecologia del quaternario, 8, 85-115. cardini l. (1958a) prime determinazioni delle faune dei nuovi giacimenti costieri musteriani del capo di leuca. quaternaria, 5, 314-315. cardini l. (1958b) prime determinazioni delle ventarole ossifere di s. isidoro e melpignano, maglie. quaternaria, 5, 315-318. cipullo a., pavia m., petrucci m., sardella r. (2006) nuovi resti di carnivori dalle “ventarole” di san sidero (maglie, lecce) (pleistocene superiore). abstracts giornate di paleontologia 2006, trieste 8-11 giugno 2006, 20. conti n., petronio c., salari l. (2010) the equids of the late pleistocene of “tana delle iene” (ceglie messapica, brindisi, southern italy). bollettino della società paleontologica italiana, 49, 227-236. corridi c. (1987) le faune pleistoceniche del salento. 2 la fauna di fondo cattìe, maglie, lecce. quaderni del museo comunale di paleontologia di maglie, 3, 5-74. cremonesi g. (1978) gli scavi nella grotta della trinità (ruffano, lecce). quaderni di ricerca scientifica, 100, 131-148. cremonesi g. (1985-86) samari (gallipoli). rivista di scienze preistoriche, 40, 424-425. cremonesi g., de lorentiis d., ingravallo e. (1984) nota preliminare sull’industria musteriana proveniente dal deposito di cattìe (maglie). quaderni del museo comunale di paleontologia di maglie, 2, 7-26. dantoni g., nardi n. (1980) la grotta riparo “marcello zei” (santa caterina, nardò). studi per l’ecologia del quaternario, 2, 97-119. de giuli c. (1983) le faune pleistoceniche del salento. 1. la fauna di san sidero 3. quaderni del museo comunale di paleontologia di maglie, 1, 45-84. di bucci d., caputo r., mastronuzzi g., fracassi u., selleri g., sansò p. (2011) first evidence of late quaternary tectonics from joint analysis in the southern adriatic foreland (italy). journal of geodynamics, 51, 141-155. di stefano g., petronio c., sardella r., savellom v., squazzini e. (1992) nuove segnalazioni di brecce ossifere nella costa fra castro marina e otranto (lecce). il quaternario, 5, 3-10. dolfini a. (2015) neolithic and copper age mortuary practices in the italian peninsula. studies in funerary archaeology, 7,18-44. fabbri p.f., lonoce n. (2011) serra cicora tra vi e v millennio a.c.: le sepolture. in: tiberi i. (ed.), origines istituto italiano di preistoria e protostoria, firenze, 187-233. facchini f. (1983) reperti antropologici. in: tinè s. (ed.), passo di corvo e la civiltà neolitica del tavoliere, sagep, genova, 134-148. falys c.g., schutkowski h., weston d.a. (2005) the distal humerus, a blind test of rogers’ sexing technique using a documented skeletal collection. journal of forensic science, 50(6), 1-6. formicola v. (1983) stature in italian prehistoric samples, with particular reference to methodological problems. homo, 34, 33-47. formicola v. (1989) la ricostruzione della statura dalle ossa degli arti. valutazioni sull'attendibilita dei risultati in campioni neolitici. rivista di antropologia, 67, 310-313. formicola v., franceschi m. (1996) regression equations for estimating stature from long bones of early holocene european samples. american journal of physical anthropology, 100, 83-88. giorgi f., bartoli f., iacumin p., mallegni f. (2005) oligoelements and isotopic geochemistry: a multidisciplinary approach to the reconstruction of the palaeodiet. human evolution, 20, 55-82. giroux c.l., wescott d.j. (2008) stature estimation based on dimensions of the bony pelvis and proximal femur. journal of forensic science, 53 (1), 65-68. giusti m. (1979) la grotta di capelvenere a s.caterina nardò (campagna di scavo 1974). studi per l’ecologia del quaternario, 1, 19-39. goude g., binder d., del lucchese a. (2014). alimentation et modes de vie néolithiques en ligurie. rivista di studi liguri, 77, 369-379. gudea a., stan f. (2012) the discriminative macroscopical identification of the bones of sheep (ovis aries), goat (capra hircus) and roe deer (capreolus capreolus) 2. elements of the hindlimb skeleton. bulletin uasmv, veterinary medicine, 69, 107-114. holliday t.w. (2000) evolution at the crossroads: modern human emergence in western asia. american anthropologist, 102, 54-6. howard a.d. (1963) the development of karst fea 37 reassessment of the ventarole karst cavities tures. national speleological society bulletin, 25, 45-65. iacoangeli o. (1996) i lagomorfi pleistocenici di melpignano (le). tesi sperimentale inedita in paleontologia dei vertebrati, università “la sapienza” di roma. ingravallo e. (1997) la passione dell'origine: giuliano cremonesi e la ricerca preistorica nel salento. conte editore, lecce. introna f., dragone m., vitale l. (1994) determinazione del sesso scheletrico mediante funzioni discriminanti applicate all’omero. rivista italiana di medicina legale, 16, 673-683. largaiolli t., martinis b., mozzi g., nardin m., rossi d., ungaro s. (1969) foglio 214 gallipoli. note illustrative della carta geologica d’italia alla scala 1: 100.000. servizio geologico d’italia, 64 pp. larsen c. s. (1999) bioarchaeology: interpreting behaviour from the human skeleton. cambridge university press, cambridge. lelli r., allen r., biondi g., calattini m., conati barbaro c., gorgoglione m.a., manfredini a., martínezlabarga c., radina f., silvestrini m., tozzi c., rickards o., craig o.e. (2012) examining dietary variability of the earliest farmers of south-eastern italy. american journal of physical anthropology, 149, 380-390. leucci g., sansò p., selleri g. (2005) studio integrato dei camini di dissoluzione carsica di roca vecchia (salento orientale). geografia fisica e dinamica quaternaria, suppl. vii, 193-199. lovejoy c.o., meindl r.s., pryzbeck t.r., mensforth r.p. (1985) chronological metamorphosis of the auricular surface of the ilium: a new method for the determination of adult skeletal age at death. american journal of physical anthropology, 68, 15 -28. malone c. (2003) the italian neolithic: a synthesis of research. journal of world prehistory, 17, 235312. mannino m.a., catalano g., talamo s., mannino g., di salvo r., schimmenti v., lalueza-fox c., messina a., petruso d., caramelli d., richards m.p., sineo l. (2012) origin and diet of the prehistoric hunter -gatherers on the mediterranean island of favignana (ègadi islands, sicily). plos one, 7 (11), e49802. doi:10.1371/journal.pone.0049802 mannino m.a., talamo s., tagliacozzo a., fiore i., nehlich o., piperno m., tusa s., collina c., di salvo r., schimmenti v., richards m.p. (2015) climate-driven environmental changes around 8,200 years ago favoured increases in cetacean strandings and mediterranean hunter-gatherers exploited them. scientific reports, 5, 16288. doi:10.1038/srep16288 mariotti v., facchini f., belcastro m.g. (2007) the study of entheses: proposal of a standardised scoring method for twenty-three entheses of the postcranial skeleton. collegium antropologicum, 31, 291-313. marra f., pandolfi l., petronio c., di stefano g., gaeta m., salari l. (2014) reassessing the sedimentary deposits and vertebrate assemblages from ponte galeria area (rome, central italy): an archive for the middle pleistocene faunas of europe. earth-science reviews, 139, 104-122. marsico a., selleri g., mastronuzzi g., sansò p., walsh n. (2003) cryptokarst: the case-study of the quaternary landforms of southern apulia (southern italy). acta carsologica, 33(2), 137-149. martin r., saller k. (1957-1962) lehrbuch der anthropologie in systematischer darstellung. 1-4, fischer, stuttgart. maviglia c. (1955) ossami fossili trovati nella grotta delle striare (otranto). natura, 46, 92-95. mirigliano g. (1941) avanzi di vertebrati quaternari di melpignano (lecce). atti della reale accademia delle scienze fisiche e matematiche di napoli, s. iii, 2 (4), 1-46. murail p., bruzek j., houët f., cunha e. (2005) dsp: a tool for probabilistic sex diagnosis using worldwide variability in hip-bone measurements. bulletins et mémoires de la société d’anthropologie de paris, 17(3-4), 167-176. nappi a., contoli l. (2008) indicazioni per un riconoscimento preliminare dei taxa del genere microtus presenti in itali. in: amori g., contoli l. & nappi a. (eds.), fauna d’italia, mammalia ii, erinaceomorpha, soricomorpha, lagomorpha, rodentia, calderini de il sole 24 ore, milano, 475-484. novotny v. (1986) sex determination of the pelvic bone: a system approach. anthropologie, 24(2-3), 197-206. orlandi g., cigna a. (1956) ancora sui reperti fossili della grotta delle striare presso otranto (lecce). natura, 47, 164-166. palacios f. (1996) systematics of the indigenous hares of italy traditionally identified as lepus europaeus pallas 1778 (mammalia: leporidae). bonner zoologische beiträge, 46, 59-91. palma di cesnola a. (1966) il paleolitico superiore arcaico (facies uluzziana) della grotta del cavallo, lecce. rivista di scienze preistoriche, 21, 3-59. palmentola g. (1987) lineamenti geologici e geomorfologici del salento leccese. quaderni ricerche centro del centro studi di geotecnica e di ingegneria (lecce), 11, 7-23. palmer a.n. (2009) cutters and pinnacles in the salem limestone of indiana. in: ginés a., knez m., slabe t. & dreybrodt w. (eds.), karst rock features karren sculpturing, carsologica, 9, 349-58. pandolfi l., petronio c. (2011) the small-sized rhinoceroses from the late pleistocene of apulia (southern italy). rivista italiana di paleontologia e stratigrafia, 117, 509-520. pandolfi l., petronio c., salari l. (2013) catastrophic death assemblages from the late pleistocene of italy: the case of avetrana karst filling (taranto, southern italy). rivista italiana di paleontologia e stratigrafia, 119, 109-124. pandolfi l., tagliacozzo a. (2013) earliest occurrence of wooly rhino (coelodonta antiquitatis) in italy (late pleistocene, grotta romanelli site). rivista italiana di paleontologia e stratigrafia, 119, 125129. 38 pandolfi l. et al. pandolfi l., marra f. (2015) rhinocerotidae (mammalia, perissodactyla) from the chronostratigraphically constrained pleistocene deposits of the urban area of rome (central italy). geobios, 48 (2), 147-167. pandolfi l., tagliacozzo a. (2015) stephanorhinus hemitoechus (mammalia, rhinocerotidae) from the late pleistocene of valle radice (sora, central italy) and re-evaluation of the morphometric variability of the species in europe. geobios, 48 (2), 169-191. pesce delfino v., scattarella v., de lucia a., ferri d., giove c. (1977) antropologia della comunità neolitica di cala colombo presso torre a mare (bari). società di storia patria per la puglia. documenti e monografie, 42, 97-178. petronio c., pandolfi l. (2008) stephanorhinus hemitoechus (falconer, 1868) del pleistocene superiore dell’area di melpignano-cursi e s. sidero (lecce, italia). geologica romana, 41, 1-12. petronio c., bellucci l., martinetto e., pandolfi l., salari l. (2011) biochronology and palaeoenvironmental changes from the middle pliocene to the late pleistocene in central italy. geodiversitas, 33, 485 -517. petronio c., di canzio e., salari l. (2007) the late pleistocene and holocene mammals in italy: new biochronological and paleoenvironmental data. palaeontographica, abt. a, 279, 147-157. quarta g., d’elia m., ingravallo e., tiberi i., calcagnile l. (2005) the neolithic site of serra cicora: results of the ams radiocarbon dating. radiocarbon, 47, 207-210. reimer p.j., bard e., bayliss a., beck j.w., blackwell p.g., bronk ramsey c., buck c.e., cheng h., edwards r.l., friedrich m., grootes p.m., guilderson t.p., haflidason h., hajdas i., hatté c., heaton t.j., hoffmann d.l., hogg a.g., hughen k.a., kaiser k.f., kromer b., manning s.w., niu m., reimer r.w., richards d.a., scott e.m., southon j.r., staff r.a., turney c.s.m., van der plicht j. (2013). intcal13 and marine13 radiocarbon age calibration curves 0-50,000 years cal bp. radiocarbon, 55, 1869-1887. rogers t.l. (1999) a visual method of determining the sex of skeletal remains using the distal humerus. journal of forensic science, 44(1), 57-60. ruff c.b., scott w.w, liu a.y-c. (1991) articular and diaphyseal remodeling of the proximal femur with changes in body mass in adults. american journal of physical anthropology, 86, 397-413. rustioni m. (1998) il cavallo e l’idruntino del salento (puglia, italia meridionale) nel quadro degli equidi del pleistocene superiore dell’italia. i quaderni, museo comunale di paleontologia di maglie, 5, 95 -121. rustioni m., mazza p., abbazzi l., delfino m., rook l., petrucci s., vianello f. (1994) the würmian fauna from sternatia (lecce, apulia, italy). bolletino società palentologica italiana, 33, 279-288. sala b. (1986) bison schoetensacki freud. from isernia la pineta (early mid-pleistocene italy) and revision of the european species of bison. palaeontographia italica, 74, 113-170. salles a.d., carvalho c.r.f., silva d.m., santana l.a. (2009) reconstruction of humeral length from measurements of its proximal and distal fragments. brazilian journal of morphological sciences, 26(2), 55-61. sardella r., bertè d., iurino d.a., cherin m., tagliacozzo a. (2014) the wolf from grotta romanelli (apulia, italy) and its implications in the evolutionary history of canis lupus in the late pleistocene of southern italy. quaternary international, 328329, 179-195. sauter m.r., privat f. (1955) sur un nouveau procédé métrique de détermination sexuelle du bassin osseuse. bulletin de la société suisse d’anthropologie et d’ethnologie, 31, 60-84. scattarella v., de lucia a. (1988) su una duplice sepoltura neolitica a polignano a mare (bari). taras rivista di archeologia, 8/1-2, 39-53. scattarella v., sublimi saponetti s., laraspata l., giove c., simone o., venturo d. (2001) il villaggio neolitico trincerato di malerba (altamura): studio antropologico della tomba 2 e osservazioni sui reperti faunistici. rivista storica-bollettino a.b.m.c. altamura, 42, 9-40. scattarella v., sublimi saponetti s., sallustio c. (1997) l’uomo neolitico di malerba: indagine antropologica sullo scheletro della sepoltura n.1. rivista storica-bollettino a.b.m.c. altamura, 38, 9-21. sjøvold t. (1990) estimation of stature from long bones utilizing the line of organic correlation. human evolution, 5, 431-447. spennato a.g. (1981) i livelli protoaurignaziani della grotta di serra cicora (nardò-lecce). studi per l’ecologia del quaternario, 3, 61-76. steele d.g. (1970) estimation of stature from fragments of long limb bones. in: stewart t.d. (ed.). personal identification in mass disaster. national museum of natural history, washington dc, 8597. tafuri m.a., robb j., belcastro m.g., mariotti v., iacumin p., di matteo a., o’connell t. (2014) herding practices in the ditched villages of the neolithic tavoliere (apulia, south-east italy). proceedings of the british academy, 198, 143-157. talamo s., richards m. (2011) a comparison of bone pretreatment methods for ams dating of samples >30,000 bp. radiocarbon, 53, 443-449. tiberi i. (2011) serra cicora tra vi e v millennio a.c. origines, istituto italiano di preistoria e protostoria, firenze. trocchi v., riga f. (2005) i lagomorfi in italia. linee guida per la conservazione e la gestione. ministero per le politiche agricole e forestali, istituto nazionale per la fauna selvatica, documenti tecnici, 25, pp. 128. trotter m., gleser g.c. (1952) estimation of stature from long bones of american white and negroes. american journal of physical anthropology, 10, 463-514 trotter m., gleser g.c. (1977) corrigenda to “estimation of stature from long limb bones of american white and negroes” american journal of 39 reassessment of the ventarole karst cavities ms. received: july 28, 2016 final text received: november 25, 2016 physical anthropology, (1952). american journal of physical anthropology, 47, 355-356. vacca e. (2006) i resti umani di contrada lamalunga (altamura) nel contesto dei ritrovamenti paleoantropologici pugliesi. ricerche speleologiche, 1, 2854. vacca e., di vella g. (2012) metric characterization of the human coxal bone on a recent italian sample and multivariate discriminant analysis to determine sex. forensic science international, 222, pp. 401. doi:10.1016/j.forsciint.2012.06.014. van klinken g.j. (1999) bone collagen quality indicators for paleodietary and radiocarbon measurement. journal of archaeological science, 26, 687695. wilkens b. (1987) la fauna del villaggio neolitico di s. maria in selva. picus, 7, 169-194. wilkens b. (2003) archeozoologia. cd-rom, schio. 40 pandolfi l. et al. amq abs spadi saccom 193-197.pub available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 193 197 ostracod assemblages from the palaeolake tiberino (piacenzian-gelasian, central italy): a synthesis marco spadi dipartimento di scienze, università roma tre, roma, italy corresponding author: m. spadi <marco.spadi@uniroma3.it> abstract: this research provides a synthesis of the studies on the non-marine ostracods recovered from the early infillings (piacenzian-gelasian) of the tiberino basin. ostracods were collected from the fosso bianco formation, deposited in a huge and deep lake (palaeolake tiberino), and ponte naja fm. that represents alluvial fan deposits that prograded into the lake. the studied ostracods are referable to 23 species, including 8 endemic species. they group in separate assemblages referable to several ecological niches, suggesting a complex lacustrine environment. this contribution permits to enlarge the dataset of non-marine ostracods distribution in central italy during the plio-pleistocene. keywords: non-marine ostracods, quaternary, ancient lake, palaeoenvironmental reconstruction, tiberino basin 1. introduction the present paper aims to provide an updated overview of the non-marine ostracod data available from the pliocene-early pleistocene deposits of the tiberino basin. in detail, ostracods are used as the main proxy for the palaeoenvironmental reconstruction of the different lacustrine palaeoenvironments. the plio-pleistocene basin-fill succession of the south tiberino basin is around 500 m thick and consists of siliciclastic and carbonate lacustrine and fluvial deposits (fig. 1). the infilling started with the fosso bianco fm. that is composed of clays with associated silty -sand laminae, sedimented in a lacustrine environment. according to basilici (1997), three sedimentological facies associations related to different depositional environments compose this formation: 1) facies association a, which is made up by fine-grained clays and marls deposited in a deep lacustrine setting; 2) facies association b that includes sands and silts corresponding to a gilbert-type delta system prograding into the lake; and 3) facies c that mainly consists of clays deposited in a marshy coastal margin with “taxodiaceae” trunks in life position. the former facies association extensively crops out from todi to san gemini, the facies association b outcrops are limited to the eastern border of the palaeolake (martani mts.) whereas the facies c crops out in the dunarobba fossil forest area (basilici, 1997) (fig. 1). the entire formation is aged late piacenzian-gelasian, based on the magnetostratigraphical, palynological and palaeocarpological analyses (abbazzi et al., 1997; pontini & bertini, 2000; napoleone et al., 2003; martinetto et al., 2014). the ponte naja fm. is composed of finegrained sheet flow deposits with palaeosols, and is probably heteropic to the upper portion of the fosso bianco fm. (basilici, 1995; 1997). according to basilici (1997), the ponte naja fm. is characterised by the facies association d, which consists of clayey silts. it corresponds to the deposition of the distal or middle distal end of an alluvial fan dominated by unchannelized flows and immature palaeosols (basilici, 1995). the large and small mammal remains collected in this unit constrain the age of the formation to the late gelasian (coste san giacomo faunal unit) (abbazzi et al., 1997), between 2.1 and 1.9 ma (bellucci et al., 2014). these two formations are unconformably overlain by the s. maria di ciciliano fm., which is composed of sandy beds and interposed laminated clays deposited in an alluvial plain with dispersed swampy areas, dated to the latest gelasian to calabrian (ambrosetti et al. 1995a; fig. 1 location and geological setting of the study area, with the studied sections, fb: fosso bianco section, dff: dunarobba fossil forest area, and ct: cava toppetti section; modified from basilici (1997). https://doi.org/10.26382/aiqua.2018.aiquaconference basilici, 1997; girotti et al., 2003). finally, along the borders of the tiberino basin crops out the acquasparta formation, dated calabrian or middle pleistocene, made of continental limestones and travertines that were deposited in small shallow lakes (ambrosetti et al., 1995a; basilici 1997). 2. material and methods the freshwater ostracods studied in the tiberino basin were collected from four different section: fosso bianco (thickness 86 m, 19 samples) and cava toppetti i (thickness 107 m; 68 samples) (fosso bianco fm., facies association a), dunarobba fossil forest area, (39 scattered samples) (fosso bianco fm., facies association c), and cava toppetti ii section (thickness 150 m; 68 samples) (ponte naja fm., facies association d) (fig. 1). the frequency matrix of the recovered autochthonous species was analysed with the cluster analysis (morisita distance measure and the unweighted pair group method using arithmetic average upgma). 3. results the autochthonous ostracods recovered in the sedimentological facies association a of the fosso bianco fm. includes 6 species: caspiocypris basilicii, caspiocypris perusia, caspiocypris posteroacuta, caspiocypris tiberina, caspiocypris tuderis and paralimnocythere umbra (spadi et al., 2018). the ostracod fauna recovered in the facies association c of the fosso bianco fm. includes 17 species referable to 12 genera: darwinula stevensoni, vestalenula cylindrica, candona (candona) improvisa, candona (neglecandona) angulata, candona (neglecandona) neglecta, candona (neglecandona) paludinica, candonopsis kingsleii, cyclocypris ovum, ilyocypris bradyi, ilyocypris decipiens, cypris granulata mandelstami, zonocypris membranae quadricella, potamocypris fulva, cyprideis crotonensis, cyprideis rectangularis, all well-known species, as well as two species recovered only in this facies, hemicypris lomastroi and paralimnocythere turgida (spadi et al., submitted). the majority of the samples from the ponte naja fm. are barren or gave only juveniles and/or broken adult valves of different species (allochthonous assemblages) pertaining to both shallow and deep waters; 9 scattered samples bore very few autochthonous species (adults and instars): c. (n.) neglecta, i. bradyi, p. umbra, and c. rectangularis 4. discussion and conclusions the ostracod from the tiberino basin, collected in the sediments associated to the deposition of the palaeolake tiberino (fosso bianco and ponte naja formations) were referable to 13 genera split into 23 species, 8 of which have been recovered only in this palaeolake. most of them were collected in the deep lacustrine (facies a) of the fosso bianco fm. (6 endemic species, five of which pertaining to a caspiocypris species flock) (spadi et al., 2018), while in the swampy lacustrine margin of the facies c of the fosso bianco fm., cropping out in the dunarobba fossil forest area, only 2 exclusive species out of 17 were recovered. the cluster analysis performed in q mode divides the samples bearing different ostracod assemblages into four clusters, suggesting that the lake hosted several different palaeobiotopes hosting diverse ostracod assemblages (figs. 2 and 3). cluster 1 comprises all of the samples from the sedimentological facies association a at fosso bianco and cava toppetti i, characterised by the presence of five caspiocypris species and p. umbra, which are typical of a rather deep lacustrine deposits (spadi et al., 2018). all the recovered caspiocypris of the palaeolake tiberino represent a species flock originated from the local speciation of one pioneer species, since they are more similar each other rather than to other known caspiocypris species of similar age (i.e. the gelasian caspiocypris species flock from the san demetrio synthem, l’aquila basin spadi et al., 2016). the peculiar composition of the endemic ostracod association, characterized only by candonidae and limnocytheridae, together with the presence of endemic molluscs 194 spadi m. fig. 2 dendrogram resulting from the cluster analysis in q-mode (samples) using the upgma method and the morisita similarity applied to the ostracods collected from the dunarobba fossil forest area. the dotted line indicates the similarity level of the separation of the four clusters. samples from: fb: fosso bianco section, dff: dunarobba fossil forest area, and ct: cava toppetti section; pnf: ponte naja fm., modified from spadi et al., submitted. (ciangherotti et al., 1998), indicates that the palaeolake tiberino is a fossil “ancient lake” and that its rather deep lacustrine areas acted as an isolated environment in which endemic speciation was enhanced. cluster 2 includes some samples collected from the dunarobba fossil forest as well as from the cava toppetti ii section. the ostracod assemblage indicates a very shallow lacustrine environment with slow waterbody motions. these samples are also characterised by freshwater prosobranchia-dominated associations (ciangherotti et al., 1998). shallow oxygenated waters rich in nutrients, typical of swampy lacustrine margins characterised by weak waves, is inferred for this welldiversified ostracod and mollusc assemblage. all the samples from ponte naja fm. fall in this cluster, pointing to similar shallow coastal environments into which the alluvial fan prograded. moreover, this finding confirms a similar age between the dunarobba fossil forest deposits and the ponte naja fm. cluster 3 is formed by the samples collected within and directly close to the fossil trunks from the dunarobba fossil forest site. the ostracod assemblage is composed of several species that can withstand permanent/temporary very shallow environments and by c. (c.) improvisa, which is typical of temporary waters (meisch, 2000). the same samples contain molluscs mainly related to terrestrial pulmonate gastropods (ciangherotti et al., 1998). the assemblage indicates a transitional environment between the hydromorphic palaeosols (cluster 4) and swampy lacustrine clays (cluster 2), probably deposited in ephemeral ponds onshore of the lake margin, which, according to ambrosetti et al. (1995b), was seldom occupied by small waterbodies. cluster 4 includes only one sample (tr23-24-25m) from the fossil forest site containing the single ostracod species p. fulva. this species is typical of very shallow aquatic environments with standing waters and has been reported in channels with leaf litter (meisch, 2000). in this sample the molluscs are represented only by terrestrial pulmonate gastropods (ciangherotti et al., 1998). these sediments correspond to a hydromorphic fig. 3 3d reconstruction of the palaeolake tiberino palaeobiotopes in late pliocene-gelasian with occurrence of the related ostracod species. legend: cluster 1: 1 caspiocypris basilicii, 2 caspiocypris perusia, 3 caspiocypris posteroacuta, 4 caspiocypris tiberina, 5 caspiocypris tuderis, 6 paralimnocythere umbra. cluster 2: 7 vestalenula cylindrica; 8 darwinula stevensoni, 9 paralimnocythere turgida sp. nov.; 10 ilyocypris bradyi, 11 candona angulata, 12 zonocypris membranae quadricella, 13 ilyocypris decipiens, 14 cypris mandelstami; 15 cyprideis crotonensis, 16 candona neglecta, 17 candona paludinica, 18 cyprideis rectangularis, 19 hemicypris lomastroi sp. nov. cluster 3: 20 candona improvisa; 21 candonopsis kingsleii; 22 cyclocypris ovum. cluster 4: 23 potamocypris fulva, modified from spadi et al., submitted. 195 ostracod record of palaeolake tiberino palaeosol. in the ostracod assemblages that populated the coastal area of the palaeolake tiberino, most of the species are well-known, although some of them are new records for the italian gelasian or have been collected in italy for the first time. for example, the fossil species c. (n.) paludinica was previously recorded only from the lower and middle paludinian beds (zancleanpiacenzian) of serbia; z. membranae quadricella is a fossil species that is widely distributed in the neogene and quaternary of turkey and the paratethys (mazzini, 2011 with references) but it was recovered in italy only in the upper tortonian deposits of the cessaniti basin (calabria) (ligios et al., 2012); v. cylindrica is known, mainly as fossil, from the neogene and quaternary of europe and turkey (minati et al., 2008 with references) and, in italy, only from the piacenzian (spadi et al., submitted). finally, c. (c.) improvisa is a living species known from the fossil record only since the calabrian, thus, the dunarobba record represents its most ancient occurrence. in a palaeobiogeographical perspective, the presence of c. g. mandelstami, c. (n.) paludinica, z. membranae quadricella and, possibly, h. lomastroi in the coastal sediments of the palaeolake tiberino is remarkable. indeed, their pliocene-gelasian distribution is limited to balkans, paludinian beds (serbia) (krstić, 2006) and eastern europe areas. it is possible to speculate that this ostracod group could have reached the tiberino basin by passive dispersal through aquatic birds shuttling back and forth between both sides of the adriatic sea. in conclusion, the palaeontological and sedimentological information provided by the literature and the present study indicate that during piacenzian–gelasian the tiberino basin hosted a huge (minimum surface of 500 km2) and rather deep (at least 50 m) lake, the palaeolake tiberino (basilici, 1997). the presence in the deep lacustrine environment of a low diversity ostracod association made only of candoninae and leptocytheridae, together with the presence of a caspiocypris species flock lead to consider the palaeolake tiberino as a palaeo-ancient lake (medici & gliozzi, 2008; spadi et al., 2018). the ostracods assemblages from the paleolake tiberino were collected in different lacustrine environments from rather deep lake bottoms (fosso bianco fm, facies a) to several diverse shallow coastal areas (fosso bianco fm., facies c and ponte naja fm.) including swampy lacustrine margins occupied by a “taxodiaceae” forest, and humid areas surrounding the lake (ephemeral ponds and hydrosols). references abbazzi l., albianelli a., ambrosetti p., argenti p., basilici g., bertini a., gentili s., masini f., napoleone g., pontini, m. r. (1997) paleontological and sedimentological record in pliocene distal alluvial fan deposits at cava toppetti (todi, central italy). bollettino della società paleontologica italiana, 36 (1-2), 5-22. ambrosetti p., basilici g., capasso barbato l., carboni m. g., di stefano g., esu d., gliozzi e., petronio c., sardella r., squazzini, e. (1995a) il pleistocene inferiore del ramo sud occidentale del bacino tiberino: aspetti litostratigrafici e biostratigrafici. il quaternario, 8(1), 19-36. ambrosetti p., basilici g., ciangherotti a. d., codipietro g., corona e., esu d., girotti o., lo monaco a., meneghini m., paganelli a., romagnoli, m. (1995b) la foresta fossile di dunarobba (terni, umbria, italia centrale): contesto litostratigrafico, sedimentologico, palinologico, dendrocronologico e paleomalacologico. il quaternario, 8(2), 465508. basilici g. (1995) sedimentologia della parte distale di una conoide alluvionale del pliocene superiore (bacino tiberino, umbria). il quaternario, 8(1), 3752. basilici g. (1997) sedimentary facies in an extensional and deep-lacustrine depositional system: the pliocene tiberino basin, central italy. sedimentary geology, 109(1-2), 73-94. bellucci l., bona f., corrado p., magri d., mazzini i., parenti f., scardia g., sardella, r. (2014) evidence of late gelasian dispersal of african fauna at coste san giacomo (anagni basin, central italy): early pleistocene environments and the background of early human occupation in europe. quaternary science reviews, 96, 72-85. ciangherotti a. d., esu d., girotti, o. (1998) review of the history of the late neogene-early quaternary non-marine molluscs of italy. mededelingen nederlands instituut voor toegepaste geowetenschapen, 60, 491-498. girotti o., capasso barbato l., esu d., gliozzi e., kotsakis a., martinetto e., petronio c., sardella r., squazzini, e. (2003) the section of torre picchio (terni, umbria, central italy): a villafranchian site rich in mammals, molluscs, ostracods and plants. rivista italiana di paleontologia e stratigrafia, 109(1), 77-98. krstić n. (2006) pliocene ostracodes of the paludinian beds in the pannonian plain, serbian part. herald of the natural history museum, 1409, belgrade. ligios s., anadón p., castorina f., d’amico c., esu d., gliozzi e., gramigna p., mola m., monegato, g. (2012) ostracoda and mollusca biodiversity and hydrochemical features of late miocene brackish basins of italy. geobios, 45, 351-367. martinetto e., bertini a., basilici g., baldanza a., bizzarri r., cherin m., gentili, s. & pontini m. r. (2014) the plant record of the dunarobba and pietrafitta sites in the plio-pleistocene palaeoenvironmental context of central italy. alpine and mediterranean quaternary, 27(1), 29-72. mazzini i. (2011) the genus zonocypris müller, 1898 (crustacea, ostracoda, cyprididae) from continental miocene deposits of central anatolia (turkey): palaeoecological and palaeobiogeographical implications. johannea geologie und paläontologie, 11, 124-125. medici m. c., gliozzi e. (2008) preliminary data on the freshwater ostracods from the middle-late pliocene tiberino “palaeo-ancient lake” (umbria, central italy). atti del museo civico di storia naturale 196 spadi m. di trieste, 53, 49-66. meisch c. (2000) freshwater ostracoda of western and central europe. spektrum akademischer verlag, 1-522, heidelberg, berlin. minati k., cabral m.c., pipík r., danielopol d.l., linhart j., neubauer, w. (2008) morphological variability among european populations of vestalenula cylindrica (straub) (crustacea, ostracoda). palaeogeography, palaeoclimatology, palaeoecology, 264, 296-305. napoleone g., albianelli a., azzaroli a., bertini a., magi m., mazzini, m. (2003) calibration of the upper valdarno basin to the plio-pleistocene for correlating the apennine continental sequences. ii quaternario, 16(1bis), 131-166. pontini m. r., bertini a. (2000) late pliocene vegetation and climate in central italy: high-resolution pollen analysis from the fosso bianco succession (tiberino basin). geobios, 33(5), 519-526. spadi m., gliozzi e., cosentino d., nocentini m. (2016) late piacenzian-gelasian freshwater ostracods (crustacea) from the l'aquila basin (central apennines, italy). journal of systematic palaeontology, 14(7), 617-642. spadi m., gliozzi e., medici m. c. (2018) a pliopleistocene caspiocypris species flock (candoninae, ostracoda) from the palaeolake tiberino (umbria, central italy). journal of systematic palaeontology, 16(5), 417-434. spadi m., gliozzi e., medici m. c. (submitted) early pleistocene (gelasian) non-marine ostracods from the dunarobba fossil forest (tiberino basin, umbria, central italy). paper in palaeontology. 197 ostracod record of palaeolake tiberino ms. received: may 6, 2018 final text received: may 18, 2018 198 amq64 panarello 3 post corr.pub � �� � �available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 30 (2), 2017, 137-154 fifteen years along the “devil’s trails”: new data and perspectives adolfo panarello 1, maria rita palombo 2, italo biddittu 3, paolo mietto 4 1 dipartimento di scienze umane, sociali e della salute, università studi cassino e lazio meridionale, cassino (fr), italy 2 dipartimento di scienze della terra, sapienza università di roma, igag_cnr, roma, italy 3istituto italiano di paleontologia umana, convitto nazionale regina margherita, anagni (fr), italy 4 dipartimento di geoscienze, università degli studi di padova, padova, italy corresponding author: a. panarello <panarello@unicas.it> abstract: on march 2003, the discovery of human fossil footprints on the volcanic ashes of the north eastern slope of roccamonfina volcano was announced to the world. they were dated to through 40ar/39ar to 349±3 ka. for this reason they are still among the oldest ichnological issues known up to now. furthermore, they are, more specifically, among the rarest ichnological evidence left by middlepleistocene man. these fossil footprints are not randomly located but, on the contrary, they are patterned to form at least two trackways (called "trackway a" and "trackway b") whose general shapes have not found comparisons in the world so far. both trackways branch off from another unique fossil structure, which is the oldest human fossil pathway identified so far. all directly collectable data from these structures has been analysed and published in a series of reports. although the high antiquity of the footprints has been for a long time the leitmotiv and the most attractive element for the media and scientists, its true paleontological power must be seen in its capacity to provide significant clues about the everyday behaviour and the environmental context of homo heidelbergensis during the middle pleistocene and whose remains have been found on very few sites of the same age. unfortunately, despite the worldwide media clamour and the great attention of the scientific world, despite the publication of many reports, the geosite is still not adequately protected and promoted and is at risk of losing a significant part of its paleontological and touristic potential. nevertheless, scientific research, in spite of great difficulties, goes on. here we report about the state of what has already been done by scientists and what still needs to be done, pointing out that no more time can be wasted to preserve one of the most important and ancient human ichnosites ever discovered. keywords: roccamonfina, devil's trails, ciampate del diavolo, fossil footprints, hominids, paleofauna, homo heidelbergensis 1. introduction the “ciampate del diavolo” palaeontological site (n41°19.954’ e14°01.488’) (fig. 1) lies on the northeastern slope of the roccamonfina volcano. before its discovery, on august 4th, 2001, only a legend existed telling the story of an uncanny walker who had left his footprints on the still burning lava after trampling on it. another local historian supposed that they might have been left by some ancient italic people (iulianis, 1986). indeed, local people, probably due to their lack of scientific knowledge, thought that only a supernatural being could have walked on the burning lava without burning itself. actually, the ground is not made up of lava but of tuff and this was the first remarkable evidence, which was noted by the discoverers (adolfo panarello and marco de angelis). as it is well known, tuff is the result of the consolidation of a pyroclastic chaotic deposit. anyway, although not completely convinced, local people accepted this explanation and passed it down from generation to generation, up until 2001. previously some local scholars had tried to find a scientific explanation of those "strange" footprints, but none of them succeeded (panarello, 2005). on march 13th, 2003, after all the necessary surveys, tests and studies, the scientific team led by paolo mietto (university of padua) announced to the world the discovery of what were the oldest fossil footprints attributable to some exemplars of the genus homo so far. they were preserved on a brown leucitic tuff (blt) formation, which was preliminarily dated between 385 and 325 ka (mietto et al., 2003). during the first surveys, carried out during the two preceding years, at least 46 footprints and at least one handprint had been detected. they were organized in at least two trackways (called "trackway a" and "trackway b") and associated with fossil prints of other human body anatomical parts and with a still unspecified number of animal footprints. most of this was published in the first official reports by avanzini et al. (2008). after some fieldwork, from 2005 to 2010, within the main palaeontological site, located near the village of "foresta" (municipality of tora e piccilli, caserta province, central italy) many other signs were detected and they are still under study. in addition to other possible animal footprints, an astonishing structure was also found, which resembled paths left in the snow by walkers moving casually. this structure was partially altered during quarrying activities in historical times, but preserved enough details to be objectively studied. actually, two doctoral works have permitted a rigorous and comprehensive detection and interpretation of the whole geology of the site (santello, 2010), in addition to the morphology and structural evolution of each of the ich� � �� � � 138 panarello a. et al. nites and pseudo-ichnites (panarello, 2016a) found during the field work carried out by the research team led by paolo mietto (university of padua). recently, an official report about the aforementioned structure, which was thought to be a fossil prehistoric path, has been published: it is actually a middle-pleistocene pathway from which at least two trackways of human fossil footprints branch off (panarello et al., 2017b). over the past two years, specific research has started on palaeoanthropological, palaeozoological and palaeo-biomedical aspects. the ichnosite of "foresta" is, in truth, exceptional because it allows to observe and to study on the same site the following aspects: it is possible to carry on a detailed geological, stratigraphical and radiometrical analysis of the substrate; there are a great number of human and animal fossil footprints, which are preserved on a very steep slope (up to 80%); human footprints are organized in gait patterns that cannot be compared to similar ones anywhere else so far; human footprints are associated with fossil prints of other human body anatomical parts (calves, possible gluteus, etc.), which have not been found elsewhere up to now; there is at least one human handprint, which is located in the open air and not in a cultural context; there is the oldest fossil pathway known up to now in the world; it preserves within its length (over 50m) both human and animal fossil footprints oriented in different directions; there are fossil footprints of palaeofauna; finally, the "ciampate del diavolo" ("devil's trails") paleontological site is one the oldest ichnosites of the world and certainly one the most precious for the study of the behaviour and the body structure of european middle-pleistocene, likely homo heidelbergensis as suggested by the presence of remains of this species in the region, i.e. the ceprano skull (ascenzi et al., 1996, 2000; manzi et al., 2000, 2010, 2016; di vincenzo et al., 2017). in this paper we report on the state of the studies to file what has been done during last fifteen years and what must still be done in a scientific perspective and, especially, in the view of the preservation and promotion of this quite unique site (not started as yet), which must be considered as one of the most important in the entire world. 2. a unique site in the world 2.1 state of the art at present, the unearthed surface, made up of brown leucitic tuff (blt) is about 2000 square meters wide. so far, 8 stratigraphic units have been surveyed. they are numbered from ls01 to ls08 and are related to pyroclastic flows of variable magnitude, composition and dating. the trampled level is ls07. it is separated from ls08 by an interstructure formed of thin, variable granular materials that facilitated the preservation of fig. 1 location of the “devil's trails” (“ciampate del diavolo”) paleontological site (roccamonfina volcano area, central italy). � �� � � 139 devil’s trails: the state of art fossil footprints during the following pyroclastic flow which put in place ls08 geological unit (santello, 2010; panarello, 2016a, 2016b) (fig. 2). various dating of ls07 are available. the first of them, at 385-325 ka, was carried out using the k/ar method (luhr & giannetti, 1987; appleton, 1972; giannetti, 1979a, 1979b; radicati of brozolo et al. 1988; ballini et al., 1989a, 1989b, 1990; cole et al., 1992; de rita & giordano, 1996). a more punctual dating at 345 ± 6 ka was provided by scaillet et al. (2008) through 40ar/39ar method. the last and most accurate radiometric 40ar/39ar dating, which was carried out on both ls07 and on ls08 layers, was done by lisa santello together with the scientific team led by paolo mietto. it provided a dating at 349 ± 3 ka (santello, 2010: 68-69). the possibility of having a dating for both the trampled layer and for what sealed it, enables scientists to precisely establish the chronological extremes of footprints within a very narrow range, which is slightly younger than the termination iv (337 ka) and which is correlated with late mis 10. this fact is not common to all the other ichnosites of hominids known in the world up to now and this must be considered as another reason for the uniqueness of the "devil's trails" site. moreover, between ls07 and ls08, no palaeosoils have been found suggesting that not much time passed between the pyroclastic flows, which put these geological units in place. from a taphonomic point of view, the lithification of the layer ls07, which allowed the fossilization of the footprints, is due to a zeolitization process (mietto et al., 2003), which was preceded by a quite common cooling and drying process of the surface. this is well documented by the presence of mud cracks flanking fossil footprints in many places (fig. 2). the trampled surface was also protected by a sort of protective debris blanket, which was created by the fallout materials before the following pyroclastic flow took place. finally, the exploration and analysis of other blt deposits which are distant from the "devil's trails" site and which are located on the eastern and southern sides of the volcano, also allowed the clarification that the zeolitization of the pyroclastic deposit did not occur homogeneously. so that inconsistent levels alternate with others, which have a lithic consistence, and this inhomogeneity has favoured the preservation of fossil footprints and has also provided the chance to see them again after their reexposure caused both by natural and anthropic agents. the human fossil footprints are aligned to form two different trackways (called "trackway a" and "trackway b") (figs. 3, 4), both descending the slope and both generally oriented toward south-east. the very singular shapes of these trackways show evident attempts to manage the steep incline, which sometimes appear successful and sometimes do not. the "trackway a", in fact, has a "z"-shaped pattern because the trackmaker was smart at judging the steep and slippery slope and in choosing the best route to safely descend it. on the contrary, trackmaker b chose a difficult route; therefore, he slipped and fell. during his attempt to regain balance, he left the print of his left hand and of other parts of his body on the still soft and already moderately cooled substrate (avanzini et al., 2008). no other hominid ichnosite has an incline comparable to that of the "devil's trails" site. in some zones, this fig. 2 a zone (red rounded), near trackway a, in which mud-crack are preserved on the original prehistoric surface. � �� � � � fig. 4 trackway b, southern view: 3d generated zenital image, scale bar 2 m (a); contour lines 5 mm (b). 140 panarello a. et al. fig. 3 trackway a, southern view: 3d generated zenital image, scale bar 2 m (a); contour lines 5 mm (b). � �� � � incline exceeds 30° and this means that the two trackmakers had to use good judgement to maintain balance during their risky downhill slope descent. this allows us to infer, through the study of gait patterns, that the trackmakers had the same pelvis structure as ours, that they were habitual bipeds and that they were fully able to make conscious and developed behavioural choices. actually all the footprints belonging to both "trackway a" and "trackway b" clearly point out evident step crossings and other foot adjustments to manage natural constraints or to test the ground in search of more stable support and balance during walking. moreover, the left hand of trackmaker b is cleverly used to regain lost balance by touching the upward sidewall flanking the long slippery slope (avanzini et al., 2008). similar evidence is not known elsewhere in the world nor other findings of handprints are known which can be safely considered completely free from cultural claims and which are located in a subaerial environment like that of the "devil's trails" site. finally, in the distal part of trackway b, the deep prints of calves and of other possible hands and of a possible gluteus are clearly visible. this recent evidence is still under study. the most recent and detailed photogrammetric surveys and the 3d models (fig. 5) created by scientists permitted to confirm the actuality of all the footprints (46, at least) of both trackway a and b. on the contrary, they have highlighted that some stratigraphical problems about trackway c still occur. so this trackway has been put under study (panarello et al., 2016; panarello and mietto, 2017) once again. at least four more human footprints were found in the western end of the site. they are still under study and will be published as soon as their analysis is complete. other partially altered human and animal footprints have been found within the space of the prehistoric pathway that dominates the tuff slope and from which the two trackways a and b branch off. studies about this prehistoric route, already noticed in 2005, has recently been completed: it proved to be, actually, the oldest human fossil pathway ever discovered so far. to date it is not comparable to other similar elements anywhere in the world both for antiquity and for the duration of the settling dynamics it suggests (panarello, 2016a, 2016b; panarello et al., 2017). the footprints of foresta, the so-called "devil's trails" (or "ciampate del diavolo") are among the oldest human fossil footprints ever discovered outside africa. in africa, only the footprints of laetoli (leakey and hay, 1979; meldrum et al., 2011; deino, 2011; masao et al., 2017), those of ileret (bennett et al., 2009), and those of koobi-fora (behrensmeyer & laporte, 1981; bennett et al., 2009) are certainly older, as well as in europe those of happisburg (norfolk, uk) (ashton et al., 2014). recent data suggest that also the single footprint found of terra amata (france) could be older (de lumley et al., 2011). many other ichnosites of hominins are known all over the world (lockley et al., 2008; bennett & morse, 2014; panarello, 2016b) and some of them are very interesting, i.e. that of willandra lakes, southeastern australia (webb et al., 2006; webb, 2007), but none of them has the same antiquity of the aforementioned sites. the sapienza university of rome recently announced the discovery of new ancient hominid ichnosite, dated to about 800 ka, in eritrea (https:// www.uniroma1.it/it/node/26082 2.2. new data contemporaneously with the study of human footprints, new lines of research have been developing over the last couple of years aimed at providing a new radiometric chronological constraint (panarello et al., 2017b) to the site, and to investigate the environmental context. specifically, archaeological surveys were performed to provide further evidence of the presence of homo heidelbergensis inside and around the roccamonfina volcanic area. furthermore, since 2016 new analysis of the palaeosurface has begun to detect vertebrate footprints fig. 5 trackway a: 3d generated depth map (zenital and transversal images) of the human fossil footprint called a25 (right foot); contour lines: 1 mm; scale bar: 10 cm. 141 devil’s trails: the state of art � � �� � � useful to giving some clues about the palaeofauna living in the same area and frequenting the site of "devil's trails" paleontological site. finally, a first analysis about the sex and the body mass of human trackmakers has been started, awaiting more in-depth physical study. 3. trackmaker's identities: new research for new clues 3.1. archaeological investigations since the second half of the nineteenth century there is known evidence of an ancient human presence in northern campania and in molise, which is documented by lithic tools, generically attributed to the "stone age" (nicolucci, 1871). the first citation about the finding of a classic acheulean biface tool in situ was given in 1876 by luigi pigorini (pigorini, 1876). although mistakenly doubting about its belonging to a generic "periodo archeolitico" (“archaeolytic period = lower palaeolithic”) he described one of the most classic italian biface stone tool with quite unusual dimensions (mm 233 x 105 x 75; fig. 6), which had been found «alla profondità di quasi sei metri tra uno strato di argilla e uno di ghiaia, cavandosi le fondamenta di una casa colonica presso il villaggio di ceppagna» ("at a depth of about six meters between a layer of clay and a gravel, breaking the foundations of a farmhouse in the village of ceppagna”) (pigorini, 1876), a small village lying only 17 km far from the “devil’s trails” paleontological site. for this reason, a systematic exploration of the palaeontological site and its surroundings has been started in 2014, in search for evidence able to confirm the first belief that trackmakers could have been some �homo heidelbergensis individuals and thus specifying also their cultural identity. researches carried out up to now have enabled us to identify some artifacts/implements scattered on the soil surface that, at the moment, cannot be attributed to any precise chronological phases. on the contrary, some more interesting data may be provided by one basalt artifact which was found right inside the “devil’s trails” palaeontological site, in the matrix, called �, between the ls07 and ls08 geological layers, i.e. between the trampled surface (ls07) and its sealing layer (ls08) (santello, 2010) (fig. 7, fig. 8). this lithic tool was accidentally uncovered by quarrymen who enlarged, in historical times, the original prehistoric surface which has recently been interpreted as a walking space located upward of the trackways a and b of human fossil footprints (panarello, 2016a; panarello et al., 2017b), but it had not been noted before the most recent field works by paolo mietto’s scientific team during the years 2013-2015. the 142 panarello a. et al. fig. 6 the stone biface from ceppagna (after pigorini, 1876). fig. 7 detail of the position, in geological stratigraphy, in which the basalt core has been found (reworking after santello, 2010). � �� � � � same artifact was left in situ up to june 2016, when it was extracted with the maximum care in order to register its exact stratigraphic location. the entire surface of the lithic tool preserves an altered two-colour patina. the weathered part, which has been exposed to the light and rain, has acquired a dark colour (dark grey hue 5y 4/1) and a slight lustration whereas the side that was embedded in the ls07 sediments has a lighter colour (grey hue 5y 5/1) and a homogeneous patina with some traces of the sediments forming the layer. fresh fractures are not recognizable. the artifact, which can be classified between the cores, has concave surfaces for multidirectional removals. one of its sides (fig. 9) has the negative of 3 removals from a single percussion plane while one comes from the opposite plane. its lower face has centripetal removals on which the impact point is not clearly distinguishable (fig. 10). its section is flat convex. its maximum measurable dimensions are mm 52 x 45.50 x 42. its weight is 94 gr. 143 devil’s trails: the state of art fig. 8 “devil’s trails” paleontological site detail photos of the lithic core from “devil’s trails” paleontological site at the moment of its finding.scale bar: 10 cm. � �� � � � the use of basalt and hard materials of volcanic origin for the manufacture of similar tools is already known from the most ancient phases of palaeolithic technology in africa in the olduvai gorge (leakey 1971) and at melka kunturé (chavaillon & berthelet, 2004; chavaillon & piperno, 2004); in eurasia at dmanisi (celiberti et al., 2004; de lumley et al., 2005); in europe at bois-de-riquet in southern france (bourguignon et al., 2015). a direct comparison with some known evidence from central italy can be made with the stone tools from two palaeolithic sites located in the frosinone province, i.e. fontana ranuccio in anagni and pofi-cava pompi. at fontana ranuccio there is a level of pedogenized tufite with solifluction and ferritic crust containing abundant fossil fauna and lithic tools which have been dated at the lower palaeolithic and attributed to the acheulean facies (ascenzi et al., 1993). k-ar dating made on leucite crystals indicated for this site an age of 458 ka (biddittu et al., 1979). at the fontana ranuccio site remains of fauna are associated with lithic and bone industries: small and medium-sized flint tools are associ 144 panarello a. et al. fig. 9 the exposed side of the lithic core found between geological layers ls07 and ls08 (scale bar: 5 cm). fig. 10 the buried side of the lithic core found between geological layers ls07 and ls08 (scale bar: 5 cm). fig. 11 zenital photo of the space between the original position of the lithic core and the footprints of the middle sized ruminant artiodactyl. � �� � � 2005; hunt and lucas, 2007; lucas, 2007; milàn et al., 2007, 2015; noe-nygaard et al., 2007; oishi et al., 2002; bromley et al., 2 009; kim et al., 2009; neto-decarvalho, 2010; buynevich et al., 2011; aramayo et al., 2015) while tracks associated with volcanic deposits were mainly preserved in volcanic ash, rarely in volcanoclastic sediments (see e.g. johnson, 1937; lucas & schultz, 2007; meldrum et al., 2011). the best preserved mammal footprints found to date at the foresta site have been detected on the subhorizontal surface, used as a route-way by homo heidelbergensis, bordering the pyroclastic flow slope (fig. 13). they belong to a middle sized ruminant artiodactyl (ichno-order artiodactipedida sensu vialov, 1966), as is clearly indicated by the elongated and wedge shape of the concave hyporelief of two hooves (medial digit iii hoof and lateral digit iv hoof), which are mirror images of each other, and show a convex, parabolic external outline, with a broader caudal part and angular distal edge, while the internal one is slightly concave. the ichnotaxonomy and trackmaker identification of artiodactyl tracks, especially those of ruminants, is however difficult because of a basic similar morphology of the foot among different taxa and the large variation in shape of footprints impressed by the same trackmaker in relation to the gait (causing the clouts to flex differently and spread apart) age and gender (affecting size and shape) (see e.g. cervipeda and pecoripeda ichnotaxa). the identification issues increase in the case of foresta footprints due to the presence of only two footprints, which are not placed in succession but side by side, nearly parallel to each other (the right better defined than the left), and show some intriguing features. both footprints show weakly convex clout walls, and markedly convergent hoof tips. subunguinus spaces are not visible, while callus pad impressions are hardly detectable on the right footprint, where the impressions of dewclaws, the small vestigial nails for digits two and five, are visible behind the tracks of the third and fourth digit, while dewclaw impressions are not well-defined in the left footprint. a narrow interdigital space is present in the right footprint, while in the left one the impression of third and fourth digits are superimposed, as the third would slide on the fourth. the size of footprints (length and breadth of about 5 and 3 cm respectively) may be consistent with that of either roe deer or chamois. the size may be consistent too with footprints of fallow deer females of young red deer individuals, though the latter usually show a more convex clout walls. the most intriguing features are, however, the presence of the dewclaw impressions combined with the footprint position, and the lack of divergence shown by lateral and medial hooves. dewclaw impressions may be present when deer slowly walk on a soft substrate, or by jumping roe deer and chamois. in the first case, however, impressions of left and right manus/pes alternate, while footprints left by a jumping roe deer they are not side by side, and impressions of third and fourth digit significantly diverge from each other. the hint feet of chamois, during racing and jumping, touch the ground side by side and in front of the forelegs, but the hooves diverge considerably and dewclaws leave their footprint distant from the third and fourth digit impressions. more data is ated with more rare basalt ones, medium-sized basalt and flint bifaces, numerous artefacts derived from bones of mammals with a particular choice on the use of palaeoloxodon antiquus diaphysis. at the same site four human molars have been found: they show morphological characteristics and chronology matching those of homo heidelbergensis (ascenzi et al. 1993). at the site of pofi cava pompi, during the extraction of "pozzolana" in the 1960s (fedele et al., 1962), human fossil ulna and tibia remains were found. they are associated with fossil fauna and rare lithic tools made up of flint and basalt. despite the absence of bifaces, the site of cava pompi show several similarities with that of fontana ranuccio because of the presence of small-sized flakes and bowls, and because of the use of basalt and animal bones for the manufacture of medium-sized artifacts (passarello and palmieri, 1968; biddittu and segre, 1978). the finding of the basalt tool inside the “devil’s trails” site on the same surface where human fossil footprints are preserved adds an important element which will certainly help to elaborate new hypotheses and to make new assumptions about the possible contemporaneity of the scatter of the precious tool along the prehistoric frequented pathways and about the possible significance of its typological aspect (the existence of a core also implies the presence of a hammerstone). another interesting feature is the position and distance of the core (1,0534 m) compared to the herbivorous footprints described in this work (fig. 11). it is, therefore, evident that more careful studies are necessary about the discovered stone tool with special attention to the micro-traces preserved on its surface. it is also necessary to go on investigating about the location of the finding paying maximum attention to the erosive processes of the layer ls07, in order to try to find other tools and generically cultural evidence strictly related to the trampled layer with the possible demonstration that human presence within the palaeontological site is exclusively proven by the well-known fossil footprints. 3.2. looking for vertebrate footprints the detection and identification of vertebrate footprints on the foresta palaeosurface is challenging due to the characteristics of the pyroclastic flow they are impressed on, and the alteration undergone by the top of the volcanoclastic deposit during its prolonged exposure to weathering agents (fig. 12). the features of footprints left by a trackmaker, indeed, strictly relate to the typology of the substratum (e.g. granulometry, water content, degree of cohesion, inclination of the impressed surface) that affect depth and shape of tracks, as well as to gait, body mass, gender, and age of trackmakers (see e.g. inter alios allen, 1997; bromley, 2001; milàn, 2007; manning, 2004; milàn & bromley, 2006, 2008; fanelli et al., 2007; marty et al., 2009; morse et al., 2013; platt & hasiotis, 2014). most quaternary vertebrate footprints and trackways have been reported from aeolian or coastal sandy deposits, some from swampy, muddy fluvio-lacustrine environments (see inter alios flor, 1989; lea, 1996; allen, 1997; quintana et al., 2001; fornos et al., 2002; lucas et al., 2002; morgan et al., 2002; scott, 145 devil’s trails: the state of art � �� � � needed to properly identify the trackmaker of artiodactipedida footprints found at the foresta site. among the other potential mammal tracks preserved in the study area on the pyroclastic flow slope, a short track way would be tentatively ascribed to a horse (hippipeda ichnotaxon, vialov, 1966). the track way consists of 3 deep rounded buds (fig. 14), crossing the human “trackway b” (avanzini et al., 2008; panarello, 2016c). the footprints are sub-circular in shape (the width is approximately equal to the length of the tracks, with convexly arched anterior (?) part and slightly expanding to nearly parallel outer margins extending posterior (?), but the caudal frog, characterising mot (?) horse footprints, is not detectable, suggesting extreme caution and more investigation before even any hypothetical identification. some problematic, badly preserved tracks, which have still not been analysed in detail, are present in the thin mud layer interbedded between the surface of the pyroclastic flow preserving the human trails and the overlain volcanic deposit. a couple of impressions apparently show some similarities to bear footprints (kowalski, 1961), especially known as regards cave bears ascribed by dietrich (2011) the new ichnogenus 146 panarello a. et al. fig. 12 “devil’s trails” site, images of paleosurface generated from 3d model: southern zenital view (a); close-up zenital photo of the area in the red box showing the alteration of the surface due to the exposure to weathering agents (scale bar: 140 cm) (b). � �� � � and species ursichnus europeus, but rarely reported from italian pleistocene sites (bocchini and coltorti, 1978). a track shows a sub-oval, roughly kidney-shaped large depression that would correspond to the manus with five small oval depressions along its convex edge perhaps corresponding to digit impressions. some pits in front of the “digit impression” would be claw marks that bear footprints usually have in front of the digits, especially when the prints are left on soft surfaces. however, due to the bad preservation and the uneven surface of the muddy layer, any identification of such traces as real footprints is, at the moment, highly speculative (fig. 15). it is worth noting, however, the high potentiality the foresta site has to provide significant clues enhancing our knowledge about the environmental context of homo heidelbergensis that inhabited the area during the middle pleistocene and whose remains have been found in a few sites, encompassing the age of the foresta one (e.g. cava pompi, passarello and palmieri, 1968; rubini et al., 2014; ceprano, manzi et al., 2010, manzi, 2016). 4. fear for the "devil's trails": remarks on the problems of preservation of the palaeontological site a careful and accurate analysis of the fossil footprint bearing surface re-exposed by both anthropic and, especially, by natural agents about 200 years ago (de angelis, 2009), was performed through a highly detailed photogrammetric survey. it revealed, also through 3d techniques, that a severe decay of blt is under way in many places of the "devil's trails" palaeontological site. middle-pleistocene human and animal footprints are very close to some of the most critical points, with a realistic imminent risk that the palaeontological evidence may be irreparably damaged. this aspect has been unambiguously communicated to the authorities responsible for the preservation of the geosite and to the schol 147 devil’s trails: the state of art fig. 13 middle sized ruminant artiodactyl footprints preserved on the surface of the prehistoric pathway: zenital photo (a); depth map (b); contour map � �� � � fig. 14 animal fossil footprints flanking east the trackway b: northern aerial photographic view (a); northern zenital detail photo (b); contour map (0.5 mm) (c); depth map (d). ars who participated to the meeting which took place in the village of tora within the "iv week of the planet earth", under the sponsorship of the italian association of quaternary research (aqua), of the soprintenza archeologia belle arti e paesaggio for the provinces of caserta and benevento and of the municipality of tora and piccilli. although scientists led by paolo mietto (university of padua) have been studying and communicating the risk of permanent loss of fossil footprints for years, no effective plan for the protection and the preservation of this important evidence has been developed by the authorities in charge. this is due to the lack of necessary funding and a bureaucratic maze. the aforementioned research team has, however, conducted a general mapping of the entire site and a high quality 3d modelling of the most important palaeontological details, 148 panarello a. et al. � �� � � in order to preserve at least scientific data and to publish them in the form of a large monographic book about the geosite of the "devil's trails". if, however, the scientific data can be considered already safe, the preservation of the original palaeosurface bearing fossil footprints is still a serious problem, which scholars have, however, presented to scientific and official bodies, providing at the same time a possible solution on which to work. the interventions carried out on the famous laetoli site (agnew & demas, 1996, 1998a, 1998b, 2005; agnew, 2002; bennett et al., 2013) at the south african sites of nahoon point (roberts, 2008, jacobs & roberts, 2009; bennett et al., 2013) and langebaan lagoon (roberts & berger, 1997; roberts, 2008; bennett et al., 2013); and central american cuatro cienegas (gonzalez et al., 2007; lockley et al., 2008; gonzalez et al., 2009; lockley & rodríguez-de la rosa, 2009; morse, 2010; bennett et al., 2013), respectively, showed that the consolidation and/or extraction of parts of the imprinted surface for their preservation inside museums are very risky and unsuitable solutions when other solutions are possible. the isolation and controlled frequentation of icnosites, where possible, seems to be the least risky and the most conservative and applicable solution. a strikingly successful example of this kind of preservation (and promotion) of an ichnosite is the structure created at acahualinca (schmincke et al., 2009, 2010; bennett et al., 2013). if substantially geographical isolation of laetoli site does not make it possible to create and manage a similar structure in that place (dalton, 2008), the extremely favourable position of the "devil's trails" site, which is located close to important communication routes, makes the chance of creating a museum facility able to contain the whole geosite and to effectively control its frequentation not only possible but moreover advisable (panarello, 2016a, 2016b, 2016c). 149 devil’s trails: the state of art fig. 15 a footprint possibly referable to ursichnus europaeus: zenital photo (a); depth map (b); contour map (0.5 mm) (c); southern close -up contoured depth map (1 mm) (d). � �� � � 5. conclusions after extremely thorough analysis and verification of all the evidence, all actual footprints have been separated from the track-like ones. this has been done by applying the most recent and accurate methods (morse et al., 2010; bennett & morse, 2014; panarello, 2016; panarello et al., 2017a; panarello et al., 2017b). a detailed and specific analysis of footprints referable to palaeofauna is underway, both to record specific details of those already known and to identify and to analyse others. this is also in view of a palaeo-environmental and palaeoecological characterization of the general territorial environment in which the "devil's trails" site is located. moss removal from the western part of the trampled tuff slope has also been scheduled, in search of other evidence related to palaeofauna. as already noted, the first palaeoanthropological surveys have already yielded important results and they will be further extended both in the volcanic area and in the surrounding alluvial and carbonate areas, with an increasingly detailed exploration. this survey is expected to provide a decisive aid in specifying the typology and the spread of prehistoric populations throughout the roccamonfina volcano area. a detailed ichnological study of trackway b is in progress with regard also to the presence and relation of fossil prints left by other anatomical parts of the human body. furthermore, as far as permitted by the degree of preservation of the human footprints, some models for the study of locomotion and of other characteristics of the human body of trackmakers are being developed. finally, an ambitious and fascinating project for the preservation, management and international promotion of the entire geosite is going to be completed. it will be submitted to the competent authorities so that it can become a reality and become a museum and a teaching and touristic facility unique in the world, just like the "devil's trails". acknowledgements we thank the two anonymous reviewers for critically reading the manuscript, and warmly acknowledge ms. teresa gray for her kind help in solving all linguistic problems and for her final linguistic revision of the previous version of the manuscript. references agnew n. (2002) methodology, conservation criteria and performance evaluation for archaeological site shelters. conservation and management of archaeological sites, 5, 1-2, 7-18. agnew n., demas m. (1996) the laetoli footprints. science, 271, 1651-1652. agnew n., demas m. (1998a) preserving the laetoli footprints. scientific american, 279, 3, 44-55. agnew n., demas m. (1998b) la conservazione delle orme di laetoli. le scienze, 363, 66-76. agnew n., demas m. (2005) la conservazione delle orme di laetoli, in aa.vv., le origini dell’uomo. viaggio nell’evoluzione dall’australopiteco a homo sapiens, collana “frontiere il meglio di scientific american”, le scienze, roma, 53-65. allen j.r. (1997) subfossil mammalian tracks (flandrian) in the severn estuary, sw britain: mechanics of formation, preservation and distribution. philosophical transactions of the royal society of london b, biological sciences, 352, 481 -518. appleton j.d. (1972) petrogenesis of potassium rich lavas from the roccamonfina volcano, roman region, italy. journal of petrology, 13, 3, 425-456. aramayo s.a., de bianco t.m., bastianelli n.v., melchor r.n. (2015) pehuen co: updated taxonomic review of a late pleistocene ichnological site in argentina. palaeogeography, palaeoclimatology, palaeoecology, 439, 144-165. ascenzi a., biddittu i, cassoli p. f., segre a. g., segre naldini e. (1993). dalla preistoria alla protostoria: dal paleolitico inferiore al bronzo nel bacino di anagni. in: dives anagnia, archeologia nella valle del sacco, mostra 30 maggio-30 giugno 1993, 2550. ascenzi a., biddittu i., cassoli p. f., segre a. g., segre naldini, e. (1996) a calvarium of late homo erectus from ceprano, italy. journal of human evolution, 31, 409-423. ascenzi a., mallegni f., manzi g., segre a.g., segrenaldini e. (2000) a reappraisal of ceprano calvaria affinities with homo erectus, after the new reconstruction. journal of human evolution, 39, 443-450. ashton n., lewis s.g., de groote i., duffy s.m., bates m., bates r., hoare p., lewis m., parfitt s.a., peglar s., williams c., stringer c. (2014) hominin footprints from early pleistocene deposits at happisburgh, uk. plosone, 9, 2, e88329. avanzini m., mietto p., panarello a., de angelis m., rolandi g. (2008) the devil’s trails: middle pleistocene human footprints preserved in a volcanoclastic deposit of southern italy. ichnos, 15, 179-189. ballini a., barberi f., laurenzi m.a., mezzetti f., oddone m., villa i.m. (1990) chrono-stratigraphy of roccamonfina volcanic complex. in genesi e differenziazione del magmatismo potassico del bordo tirrenico: convegno autunnale: ischia, 15-18 ottobre 1990 / societa italiana di mineralogia e petrologia, abstract book, 18-19. ballini a., barberi f., laurenzi m.a., mezzetti f., villa i.m. (1989a) nuovi dati sulla stratigrafia del vulcano di roccamonfina. bollettino gnv, 2, 533-556. ballini a., frullani a., mezzetti f. (1989b) la formazione piroclastica del tufo trachitico bianco («white trachytic tuff»-wtt auctorum) del vulcano di roccamonfina. bollettino gnv, 2, 557-574. behrensmeyer a.k., laporte l.f. (1981) footprints of a pleistocene hominid in northern kenya. nature, 289, 167-169. bennett m.r., falkingham p., morse s.a., bates k., crompton r.h. (2013) preserving the impossible: conservation of soft-sediment hominin footprint 150 panarello a. et al. � �� � � sites and strategies for three-dimensional digital data capture. plosone, 8, 4, e60755 (1-15). bennett m.r., harris j.w.k., richmond b.g., braun d.r., mbua e., kiura p., olago d., kibunjia m., omuombo c., behrensmeyer a.k., huddart d., gonzalez s. (2009) early hominin foot morphology based on 1,5 million year old footprints from ileret, kenya. science, 323, 1197-1201. bennett m.r., morse s.a. (2014) human footprints: fossilised locomotion? springer, cham heidelberg-new york-dordrecht-london, pp. 216. biddittu i., segre a. g. (1978). paleolitico inferiore a cava pompi presso pofi, frosinone. archeologia laziale quaderni per l’archeologia etruscoitalica, 1, 78-79. biddittu i., cassoli p.f., radicati di brozolo f., segre a.g., segre naldini e., villa i. (1979). anagni a kar dated lower and middle-pleistocene site, central italy: preliminary report. quaternaria, 21, 3552. bocchini, a., coltorti m. (1978) unghiate ed impronte di ursus spelaeus nella grotta del fiume nella gola di frasassi (ancona): rassegna speleologia italiana memoria, 12, 138-141. bourguignon l., crochet j-y., capdevila r., ivorra j., antoine p-o., agustí j., barsky d., blain h.a., boulbes n., bruxelles l., claude j., cochard d., filoux a., firmat c., lozano-fernández i., magniez p., pelletier m., rios-garaizar j., testu a., valensi p., de weyer l. (2015) bois de riquet (lézignan-la-cèbe, hérault): a late early pleistocene archeological occurrence in southern france. quaternary international, 393 (2016), 24-40. doi: 10.1016/j.quaint.2015.06.037 bromley r.g. (2001) tetrapod tracks deeply set in unsuitable substrates: recent musk oxen in fluid earth (east greenland) and pleistocene caprines in aeolian sand (mallorca). bulletin of the geological society of denmark, 48, 209-215. bromley r.g., milàn j., uchman a., hansen k.s. (2009) rheotactic macaronichnus, and human and cattle trackways in holocene beachrock, greece: reconstruction of paleoshoreline orientation. ichnos,16, 1-2, 103-117. buynevich i.v., darrow j.s., grimes z.t., seminack c.t., griffis n. (2011) ungulate tracks in coastal sands: recognition and sedimentological significance. journal of coastal research, 64, 334. celiberti v., barsky d., cauche d., notter o., nioradze m., lordkipanidze d., gabunia l.k., de lumley h. (2004). les industries lithiques archaïques du site de dmanisi, géorgie. in: actes du xive congrès du l’u.i.s.p.p., université de liège, 2-8 septembre 2001, 2004. bar international series, 1272, 2936. chavaillon j., berthelet a. (2004) the archaeological sites of melka kunture. in: chavaillon j., piperno m. (eds.), studies on the early paleolithic site of melka kunture, ethiopia. istituto italiano di preistoria e protostoria, firenze: 25-80. chavaillon, j., piperno, m. (eds.), (2004) studies on the early paleolithic site of melka kunture, ethiopia. origines, firenze, 93-101. cole p.d., guest j.e., duncan a.m., chester d.k., bianchi r. (1992) post-collapse volcanic history of calderas on a composite volcano: an example from roccamonfina, southern italy. bulletin of volcanology, 54, 253-266. dalton r. (2008) fears for oldest human footprints. nature, 451, 118. de angelis m. (2009) riscontri archivistici sulla origine del toponimo “ciampate del diavolo”. communication at symposium “ciampate del diavolo: mezzo passo nella leggenda... un passo nella storia”, tora e piccilli, 17 ottobre 2009, in press. de lumley h., nioradzé m., barsky d., cauche d., celiberti v., nioradzé g., notter o., zvania d., lordkipanidze d. (2005) the pre-oldowayen lithic industry from the beginning of the lower pleistocene at the dmanissi site in georgia. l’anthropologie, 109, 1-182. de lumley m.a., lamy p., mafart b. (2011) une empreinte de pied humain acheuléen dans la dune littorale du site de terra amata. ensemble stratigraphique c1b. in de lumley h. (ed.), terra amata: nice, alpes-maritimes, france, vol. 2: palynologie, anthracologie, faunes, mollusques, écologie et biogéomorphologie, paléoanthropologie, empreinte de pied humain, coprolithes. cnrs, paris, 483-507. de rita d., giordano g. (1996) volcanological and structural evolution of roccamonfina volcano (italy): origin of the summit caldera. in mcguire w.j., jones a.p. and neuberg j. (eds.), volcano instability on the earth and other planets. geological society, london, special publications, 110, 209-224. di vincenzo f. profico a., bernardini f., cerroni v., dreossi d., schlager s., zaio p., benazzi s., biddittu i., rubini m., tuniz c., manzi g. (2017) digital reconstruction of the ceprano calvarium (italy), and implications for its interpretation. nature, scientific reports, 7, 13974. doi:10.1038/s41598-017-14437-2. deino a.l. (2011) 40ar/39ar dating of laetoli, tanzania. in harrison t. (ed.), paleontology and geology of laetoli: human evolution in context volume 1: geology, geochronology, paleoecology and paleoenvironment, springer, new york, 77-97. diedrich c.g. (2011) an overview of the ichnological and ethological studies in the cave bear den in ur�ilor cave (western carpathians, romania). ichnos, 18, 1, 9-26. fanelli f., palombo m.r., pillola g.l., ibba a. (2007) tracks and trackways of praemegaceros cazioti (depéret (1897), artiodactyla, cervidae) in the pleistocene coastal deposits from sardinia (western mediterranean, italy). bollettino società paleontologica italiana, 46, 1, 47-54. flor g. (1989) estructuras de deformación por pisadas de cérvidos en la duna cementada de gorliz (vizcaya, n de españa). rev. soc. geol. españa, 2, 1-2, 23-29. fornós j.j., bromley r.g., clemmensen l.b., rodr�guez-perea a. (2002) tracks and trackways of myotragus balearicus bate (artiodactyla, 151 devil’s trails: the state of art � �� � � caprinae) in pleistocene aeolianites from mallorca (balearic islands, western mediterranean). pa laeogeog raphy , pa laeoc l ima to l ogy , palaeoecology, 180, 4, 277-313. giannetti b. (1979a) the geology of roccamonfina caldera (campanian province, italy). giornale di geologia (s. 2), 43, 187-206. giannetti b. (1979b) studio geologico-petrografico della caldera del vulcano di roccamonfina (italia centro-meridionale). bollettino del servizio geologico d’italia, 100, 311-374. gonzalez a.h.g., lockley m.g., rojas c.s., espinoza j.l., gonzalez s. (2007) notes on a re-discovery of a 'lost' hominid footprint site from the cuatro cienegas basin (coahuila), mexico, in lucas s.g., spielmann j.a. and lockley m.g. (eds.), cenozoic vertebrate tracks and traces. new mexico museum of natural history and science bulletin, 42, 11-15. gonzalez a.h.g., lockley m.g., rojas c.s., lopez espinoza j., gonzalez s. (2009) human tracks from quaternary tufa deposits, cuatro cienegas, coahuila, mexico. ichnos, 16, 12-24. hunt a. p., lucas s. g. (2007) late triassic tetrapod tracks of western north america. new mexico museum of natural history and science bulletin, 40, 215-230. iulianis a. (1986) tora e piccilli. storia, tradizioni e immagini, nuove edizioni ci.esse.ti., napoli, pp. 122. jacobs z., roberts d. (2009) last interglacial age for aeolian and marine deposits and the nahoon fossil human footprints, southeast coast of south africa. quaternary geochronology, 4 (2), 160-169. johnston c. s. (1937) tracks from the pliocene of west texas. american midland naturalist, 18, 1, 147-152. kim k.s., kim j.y., kim s.h., lee c.z., lim j.d. (2009) preliminary report on hominid and other vertebrate footprints from the late quaternary strata of jeju island, korea. ichnos, 16, 1-2, 1-11. kowalski, k. (1961) traces of a cave bear. priroda, 2, 110-112 (in russian). lea p.d. (1996) vertebrate tracks in pleistocene eolian sand-sheet deposits of alaska. quaternary research, 45, 2, 226-240. leakey m. 1971. olduvai gorge 1960-1963. in: excavations in bed i and ii, vol. 3. cambridge university press, cambridge. leakey m.d., hay r.l. (1979) pliocene footprints in the laetoli beds at laetoli, northern tanzania. nature, 278, 317-323. lockley m., roberts g., kim j.y. (2008). in the footprints of our ancestors: an overview of the hominid track record. ichnos, 15, 106-125. lockley m.g., rodríguez-de la rosa r.a. (2009) preservation of human tracks in arid environments. ichnos, 16, 98-102. lucas s., schultz g. (2007) miocene vertebrate footprints from the texas panhandle. cenozoic vertebrate tracks and traces. new mexico museum of natural history and science bulletin, 42, 177-183. lucas s.g. (2007) tetrapod footprint biostratigraphy and biochronology. ichnos 14 (1-2), 5-38. lucas s.g., morgan g.s., hawley j.w., love d.w., myers r.g. (2002) mammal footprints from the upper pleistocene of the tularosa basin, doña ana county, new mexico. geology of white sands: new mexico geological society, guidebook, 53, 285-288. luhr j.f., giannetti b. (1987) the brown leucitic tuff of roccamonfina volcano (roman region, italy). contributions to mineralogy and petrology, 95, 420 -436. manning, p.l. (2004) a new approach to the analysis and interpretation of tracks: examples from the dinosauria. in mcilroy, d. (ed.), the application of ichnology to palaeoenvironmental and stratigraphical analysis. geological society of london, special publication, 228, 93-128. manzi g., mallegni f., ascenzi a. (2000) a cranium for the earliest europeans: phylogenetic position of the hominid from ceprano, italy. proceedings of the national academy of science, 98, 17, 10111016. manzi g., magri d., milli s., palombo m.r., margari v., celiberti v., barbieri m., barbieri m., melis r.t., rubini m., ruffo m. (2010) the new chronology of the ceprano calvarium (italy). journal of human evolution, 59 (5), 580-585. manzi g. (2016) humans of the middle pleistocene: the controversial calvarium from ceprano (italy) and its significance for the origin and variability of homo heidelbergensis. quaternary international, 411, 254-261. marty d., strasser a., meyer c.a. (2009) formation and taphonomy of human footprints in microbial mats of present-day tidal-flat environments: implications for the study of fossil footprints. ichnos, 16 (1-2), 127-142. masao f.t., ichumbaki e.b., cherin m., barili a., boschian g., iurino d.a., menconero s., moggicecchi j., manzi g. (2017) new footprints from laetoli (tanzania) provide evidence for marked body size variation in early hominins. elife, 5:e19568, 1-29. doi: 10.7554/elife.19568 meldrum d.j., lockley m.g., lucas s.g., musiba c. (2011) ichnotaxonomy of the laetoli trackways: the earliest hominin footprints. journal of african earth sciences, 60, 1-2, 1-12. mietto, p., avanzini, m., rolandi g. (2003) human footprints in pleistocene volcanic ash. nature, 422, 133. milàn j., bromley r.g. (2006) true tracks, undertracks and eroded tracks, experimental work with tetrapod tracks in laboratory and field. palaeogeography, palaeoclimatology, palaeoecology, 231, 3-4, 253-264. milàn j., clemmensen l.b., buchardt b., noe-nygaard n. (2007) a late holocene tracksite in the lodbjerg dune system, northwest jylland, denmark. in lucas s.g., spielmann j.a., lockley m.g. (2007) cenozoic vertebrate tracks and traces. new mexico museum of natural history and science bulletin, 42, 241-249. milàn j., bromley r. g. (2008) the impact of sediment 152 panarello a. et al. consistency on track and undertrack morphology: experiments with emu tracks in layered cement. ichnos, 15,18-24. milàn j., bromley r. g., titschack j., theodorou g. (2007) a diverse vertebrate ichnofauna from the quaternary eolian oolite, rhodes, greece. sediment-organism interactions: a multi-faceted ichnology, sepm special publication, 88, 333343. milàn j., theodorou g., loope d. b., panayides i., clemmesnsen l. b., gkioni m. (2015) vertebrate tracks in late pleistocene-early holocene (?) carbonate aeolianites, paphos, cyprus. annales societatis geologorum poloniae, 85, 507-514. morgan g.s., lucas s.g., hawle j.w., love d.w., myers r.g. (2002) mammal footprints from pleistocene lake otero. tularosa basin, white sands missile range, dona ana county, new mexico: new mexico. geology, 24, 67. morse s.a. (2010) footprint verification: a new method and case study. a thesis submitted to the graduate school-new brunswick rutgers, the state university of new jersey in partial fulfillment of the requirements for the degree of master of arts graduate program in anthropology written under the direction of dr. j.w.k. harris, pp. 95. morse s.a., bennet m.r., liutkus�pierce, c., thackeray f., mcclymont j., savage r., crompton r.h. (2013) holocene footprints in namibia: the influence of substrate on footprint variability. american journal of physical anthropology, 151(2), 265-279. neto-de-carvalho c. (2010) vertebrate tracksites from the mid-late pleistocene eolianites of portugal: the first record of elephant tracks in europe. geological quarterly, 53, 4, 407-414. nicolucci g. (1871) l’âge de la pierre dans les provinces napolitaines. congrès international d’anthropologie et d’archéologie préhistorique [compte rendu de la 5 e session], 17-48. noe-nygaard n., milàn j., hede m. u., holm j. (2007) a reindeer track from a drill core, and lake basin development of the late glacial lille slotseng kettle-hole basin, south-east jylland, denmark. bulletin of the geological society of denmark, 55, 85-95. oishi m., terasawa h., sakai m., fujii t. (2002) fossil footprints of early pleistocene large mammals from the construction site of the hanamaki city museum, hanamaki city, iwate prefecture. research report of the hanamaki city museum project office, 1, 73-94. panarello a. (2005) le impronte umane fossili di "foresta". per una lettura storica del sito e una corretta interpretazione della scoperta scientifica. intergraphica, vairano scalo, pp. 15. panarello a. (2016a) il sito con impronte umane pleistoceniche di foresta (vulcano di roccamonfina, caserta) quale laboratorio ideale per valutazioni oggettive sulle più antiche direttrici di transito umano e sui condizionamenti geomorfologici nelle logiche insediative. a phd thesis in "storia, letteratura e territorio" (history, literature and lansdcape evolution), università degli studi di cassino e del lazio meridionale, dipartimento di scienze umane, sociali e della salute, pp. 408, + 27 tables ft. panarello a. (2016b) elementi di paleoicnologia degli ominidi. armando caramanica editore, marina di minturno, pp. 228. panarello a. (2016c) l’areale vulcanico interno del roccamonfina: quadri ambientali e analisi di contesto. «terra laboris, itinerari di ricerca», 32, armando caramanica editore, marina di minturno, pp. 79. panarello a., mietto p. (2017) can it be an actual human fossil footprint? the combined method helps to give an answer. alpine and mediterranean quaternary 30, 2, 105-123. panarello a., santello l., farinaro g., bennett m. r., mietto p. (2017a) walking along the oldest human fossil pathway (roccamonfina volcano, central italy)? journal of archaeological science: reports, 13, 476-490. panarello a., santello l., belvedere m., mietto p. (2017b) is it human? discriminating between real tracks and track-like structures. ichnos, 1-10. doi: 10.1080/10420940.2017.1337010. passarello p., palmieri a. (1968) studio sui resti umani di tibia e di ulna provenienti da strati pleistocenici della cava pompi di pofi (frosinone). rivista di antropologia, 55, 139-162. pigorini l. (1876) l’età della pietra nella provincia di molise. bullettino di paletnologia italiana, 2, 119128. platt b.f., hasiotis s.t. (2014) novel neoichnology of elephants: nonlocomotive interactions with sediment, locomotion traces in partially snow-covered sediment, and implications for proboscidean paleoichnology. in: hembree d.i., platt b.f., smith, j.j. (eds.), experimental approaches to understanding fossil organisms, topics in geobiology 41, springer sciences & business, the netherlands, 371-393. quintana c., martínez g., osterrieth m., mazzanti d. (2001) footprints of mammals in a cave of eastern edge of tandilia range, late pleistocene of buenos aires province, argentina. current research in the pleistocene, 18, 110-111. radicati di brozolo f., di girolamo p., turi b., oddone m. (1988) 40ar/39ar and k-ar dating of k-rich rocks from roccamonfina volcano, roman comagmatic region, italy. geochimica cosmochimica acta, 52, 1435-1441. roberts d., berger l.r. (1997) last interglacial (c. 117 kyr) human footprints from south africa. south african journal of science, 93, 8, 349-350. roberts d.l. (2008) last interglacial hominid and associated vertebrate fossil trackways in coastal eolianites, south africa. ichnos, 15, 190-207. rubini m., cerroni v., festa g., sardella, r., zaio p. (2014) a revision of hominin fossil teeth from fontana ranuccio (middle pleistocene, anagni, frosinone, italy). journal of human evolution, 77, 204-216. santello l. (2010) analysis of a trampled formation: the brown leucitic tuff (roccamonfina volcano, 153 devil’s trails: the state of art southern italy). a phd thesis in “scienze della terra” (earth sciences), università degli studi di padova, dipartimento di geoscienze, pp. 136. scaillet s., vita-scaillet g., guillou h. (2008) oldest human footprints dated by ar/ar. earth and planetary science letters, 275, 320-325. schmincke h.u., rausch j., kutterolf s., freundt a. (2010) walking through volcanic mud: the 2,100 year-old acahualinca footprints (nicaragua) ii: the acahualinca people, environmental conditions and motivation. international journal of earth sciences, 99 (suppl. 1), 279-292. schmincke h.u., kutterolf s., perez w., rausch j., freundt a., strauch w. (2009) walking through volcanic mud: the 2,100 year old acahualinca footprints (nicaragua). i: stratigraphy, lithology, volcanology and age of the acahualinca section. bulletin of volcanology, 71, 479-493. scott j.j. (2005) taphonomy of modern and ancient vertebrate traces in the marginal sediments of saline, alkaline and freshwater lakes, baringobogoria basin, kenya rift valley. unpublished msc. thesis, university of saskatchewan, pp. 611. vialov o.s. (1966) sledy zhiznedeyatelnosti organizmow i ikh paleontologicheskoe znachenie. naukova dumka, pp. 219 (in russian). webb s., cupper m.l., robins r. (2006) pleistocene human footprints from the willandra lakes, southeastern australia. journal of human evolution, 50, 4, 405-413. webb s. (2007) further research of the willandra lakes fossil footprint site, southeastern australia. journal of human evolution, 52, 6, 711-715. 154 panarello a. et al. ms. received: july 27, 2017 final text received: december 12, 2017 amq abs fayek et al palcom 125-129.pub available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 125 129 stable isotope stratigraphy of travertine sequences from channel deposits at hierapolis of phrygia (denizli, turkey) asmaa fayek 1, mauro brilli 2, nicolas guyennon 3, francesca giustini 2, mario voltaggio 2 1 geology department, faculty of science, helwan university, cairo, egypt 2 igag, cnr, roma, italy 3 irsa, cnr, roma, italy corresponding author: m. brilli <mauro.brilli@cnr.it> abstract: travertine sequences from petrified channels used in antiquity as water supply canals in the city of hierapolis (denizli, turkey) for irrigation and domestic use were sampled and analyzed for stable isotopes composition. data records from two channels show composite quasi-periodic variations. radium-226 activity was measured to calculate temporal constrains; one of the channels, 182cm thick, deposited in 790±71 years, whereas the other, 644cm thick, in 995±71 years. isotope data, studied through spectral and cross-spectral analysis, indicate that the different oscillation frequencies may be related to surface temperature and rainfall pulses. keywords: isotope stratigraphy, petrified channels, hierapolis of phrygia 1. introduction aerial views and satellite images are definitely the best point to understand how the urban and suburban landscape of hierapolis of phrygia is strongly characterized by the presence of travertine channels (scardozzi, 2013); the dense network that they draw in some areas of the city and outside had already been perceived as an element connoting the topography of the place by the scholars who visited the remains of the city in the nineteenth century and represented it schematically in maps and some views (e.g., trémaux, 1958). the travertine channels of hierapolis originate from thermal springs on the terrace on which the city was founded. they consist of continuous calcareous deposit which has grown over the centuries, often reaching impressive forms today (hancock et al., 2000; özkul et al., 2002). the complex network of travertine channels is divided into two distinct groups from the topographic and chronological point of view (di taranto, 2015). the remains of those canals that descend from the city's terrace towards the fields of the underlying lykos valley can be referred to the oldest group; these channels had the dual function of irrigation and delimitation of agricultural land. they are still preserved today for long distances and with remarkable heights (up to 10 m). the exact location of the springs that fed these canals is not known, but it is possible that they could be found along the edge of the terrace. the most recent group, datable to the middlebyzantine period, is constituted of a network of travertine channels developed within the urban area. the archaeological excavations have confirmed its use between the mid-seventh century ad and about the 1354 ad when an earthquake caused the definitive abandonment of the city. from the urban area the waters flowed towards the valley, partly exploiting the oldest conduits, thus contributing to increase the carbonate accretion, which generated, in the course of the following centuries, the monumental canals we see today. travertine channels are highly interesting constructions, since they are related to human activity. these deposits are often linked to thermal springs. their formation is a consequence of the thermal shock induced by the differences between water and air temperatures that accelerate dissolved carbonate precipitation, producing huge bodies. the kinetics of this cooling are a function firstly of thermal water/air contrast, and secondly of the distance from the spring. jimenez et al. (2006) isotopically studied this peculiar travertine deposits at alicùn de las torres (granada, spain) where active channels are still growing. in the present study, two channels were selected for isotope stratigraphy. their rapid accretion allows evaluation of climatic variations at decadal scale resolution. 2. materials and methods two travertine channels (b and c) were sampled continuously along the central axis of their vertical section where cut surfaces are exposed (fig. 1); before the sampling, a carbonate layer, a few centimeters thick, was scraped to eliminate the external surface exposed to the atmosphere. channel b is located inside the urban area at about 300m away from the closest spring orifice, with a height of 183cm. on contrast, travertine channel c is situated on the steep slopes in the north west side of hierapolis. this channel has grown as high as around 10m; it was sampled for 644cm from the top. oxygen and carbon isotopes measurements were performed on a total of 655 samples from channel b and 182 samples from channel c by using acid digestion technique (gasbench ii (thermo) on line with a delta plus mass spectrometer). results were expressed in delta per mill versus v-pdb standard. https://doi.org/10.26382/aiqua.2018.aiquaconference the sequences were temporally constrained by the dating method based on the decay of radium-226; the details of this method are described by romano et al. (1987). 3. results and discussion dating archaeological information provided some constraints to the time of deposition of the travertine channel bodies. the upper temporal limit of the activity of the channels can be placed around 1354 ad, when a strong earthquake caused the destruction of hierapolis. channel b rests on a pavement of the vii century, whereas the bottom of channel c surely dates back to the roman imperial times (di taranto, 2015). 226ra dating method allows the definition of a time interval between two points selected within the sequence. analyses for 226ra 230th, 232th and 238u activities were run on two samples from channel b (at the top and bottom of the sequence), and on three samples from channel c (at the top, bottom and 380cm from the bottom). formulation of the equations for 226ra method is based on the widely used u-th methods with the further introduction of 230th to 226ra decay. two sources contribute to the activity of 226ra: (i) 226ra originally deposited in the calcite, and (ii) 226ra in equilibrium with 230th, leached from silicatic residue during acid attack (noncarbonatic 226ra). the difference between the total 226ra activity, measured in our samples, and noncarbonatic 226ra activity gives the 226ra excess. the initial activity of 226ra is not known, but assuming it remained constant during the deposition of the travertine sequence it is possible to have the age difference at different levels. the following equation was used to estimate the age difference from 226raexcess ratio between two samples collected at different levels of the sequences: 126 fig. 1 petrified channels at hierapolis. a) panoramic view; b) cut surface along channel c (the bar is 3 m long); c) channel b is the main collector which runs nw – se through the ancient city of hierapolis. fayek a. et al. where 226raexcess (t) is the excess of radium at time t, 226raexcess (o) is the initial activity of 226ra, λ is the 226ra decay constant. the difference between this equation at time t1 and the same equation a time t2, which represent two levels of the sequence, gives the equation of age difference (∆t): 226raexcess is calculated from the difference 226ra 230th, assuming secular equilibrium between 230th and 226ra 127 in the non-carbonatic component. in table 1 are listed the results of the spectrometric analysis and the ∆t calculated in channels b and c. stable isotopes isotope records were converted from data versus thickness to data versus time using the results given by the radium-226 chronology (fig. 2 and b). the relative time vector (t*) associated to the δ18o and δ13c series has been obtained using a linear piecewise interpolation of available durations, under the hypothesis of constant rate of deposition, and setting to 0 the top of the sequences. on initial consideration, the records b and c show low amplitude, composite cyclic variations for both carbon and oxygen records. the main issue is to decipher the various, competing factors that drive oxygen and carbon isotope variations, in order to recover unambiguous paleoclimatic signals. δ18o of travertine calcite reflects the temperature and δ18o of the water where calcite deposited. the δ18o of the water may have been varied in the past for different reasons, namely variation in δ18o of meteoric precipitation, mixing between shallow and deep groundwaters, evaporation occurred from the spring orifice to the sampling locations and consequent isotopic disequilibrium during calcite precipitation (pentecost, 2005; andrews, 2006; and references therein). δ13c reflects the sources of carbon which contribute to the carbon species in solution, the tendency of co2 dissolved in the groundwater to equilibrate with atmosphere and evade at surface emergences, and, subsequently, along the surface flow (pentecost, 2005; andrews, 2006; and references therein). considering the context of channelized flow of thermal waters and the sampling locations at a certain distance from the springs, the temperature drop is an important factor on which the oxygen isotope composition depends; it also influences the amount of co2 evasion (the increase in distance implies a progressive thermal decline). air temperature induces, when lowers or rises, an increase or decrease in δ18o, whereas δ13c behaves oppositely since higher temperature favors co2 evasion leaving behind a residual co2 isotopically “heavier” and vice versa. this implies that the records of carbon and oxygen isotopes will be negatively correlated when temperature is the main factor to influence isotopes in carbonate formation. oxygen isotopes in travertine carbonates may also depend on the variations of oxygen isotope composition of groundwater which is, in turn, derived by meteoric precipitation; isotope ratios in precipitation are averagely lower in cold climates and higher in warm periods, an effect that can be more or less evident in groundwaters according to precipitation intensity. cold humid climatic conditions may promote soil biogenic co2 formation, resulting in isotopically light carbon isotope ratios. the increased introduction of soil co2 into groundwater produces a lowering in the δ13c of the calcite precipitated around the springs. in the case of the area studied this lowering was modulated by heavy carbon co2 sources, generated by decarbonation of local bedrock and mantle degassing, of which the local thermal system is rich (dilsiz, 2006; kele et al., 2011). these mechanisms, however, generate carbon and oxygen isotope records that co-vary positively. on the basis of the isotope record profiles, it seems that the factors described above may have influenced recent past waters at hierapolis thermal springs and the calcium carbonate of the channels. variations in δ13c seem to correlate positively with δ18o at higher frequency oscillations, whereas negatively at lower frequencies. these evidences may be related to the mechanisms above described: δ13c/δ18o positive covariance can be related to the variation in air temperature, whereas negative covariance to the variations in climate and precipitation regime reflected in groundwater isotopes. cross wavelet spectral analysis was applied to study the oscillatory nature of the isotope data records to investigate the different responses in time to climate variations (fig. 2c). the mathematical basis of this technique is given by grossmann & morlet (1984) and a complete description by torrence & compo (1998). the wavelet analysis carried out in this study was performed using the free matlab-software package (wtc-r16) available at the url: http://noc.ac.uk/using-science/crosswaveletwavelet-coherence (grinsted et al., 2004). a physically consistent definition of energy for the wavelet power spectrum has been adopted following liu et al. (2007) to tab. 1 age difference (∆t) in years between the levels where samples of channel b and c were selected. sample collected from the middle of channel c was at 3.80 m from the bottom. 230th, 232th were determined by isotope dilution alpha spectrometry, 226ra and 238u were determined by high resolution gamma spectrometry. stable isotope stratigraphy of travertine sequences allow a direct comparison of the spectral peaks across scales. following guyennon et al. (2014), the associated global cross-wavelet spectrum is defined for amplitude (gxws-amplitude) and phase (gxws-phase) as the time integration of the significant (p value <0.05) wavelet coefficients. the gxws amplitude and phase gives a synthetic description of the main common signals characterizing the time series. wavelet analysis reveals spectral peaks of significant intensity at frequencies corresponding to 7 and 1112 years, especially evident in sequence c which has higher resolution; for these periodicities the c and o records are prevalently in phase. at lower frequencies in sequence c, it is possible to evidence spectral peaks between 25 – 35 and at 65 years, with c and o records prevalently in phase opposition; whereas in sequence b, peak at 50 years with c and o records in phase. the periods from 7 to 12 years can represent the response of the data to the aquifer dynamic pulses which, being influenced by meteoric precipitation, are strongly linked to shallow, fast aquifer circulation and to alternation of not only cold/warm climate but also humid/ arid conditions. at higher periodicities, around 30 yrs and 65 yrs, the surface temperature oscillation seems to have influenced most the record c. the peak at 50 years recorded in the sequence b should be related to climatic variation filtered by the local aquifer system; this peak is not observed in the record of sequence c. the sampling location of the two channels with respect to the spring orifice are surely different and this may have played a role on this discrepancy; the b sampling site is closer to the spring orifice than the c sampling site, as indicated from the average carbon isotopic composition of the two channels δ13c = +6.2‰ in b; δ13c = +6.7‰ in c). the carbon isotopic composition of b lower than c may indicate a larger co2 degassing effect at site c, therefore a shorter distance traveled by the water to reach the site b. an average 0.5‰ difference, considering the magnitude of amplitude variations observable in the carbon records, can be considered significant to obfuscate the co2 evasion effect and recording the co2 variations related to the co2 mixing occurred in the groundwater system. 4. conclusion two sequences reconstructed from travertine channel deposits used at hierapolis of phrygia as water collectors were analyzed for carbon and oxygen isotope stratigraphy. the radium-226 dating method constrained the time interval covered by the sequences revealing that the channel b sequence is shorter in duration (790±71 years) and the channel c sequence is longer (995±71 years). it is likely that the top of both sequences can be dated close to the 1354 ad, when a strong earthquake destroyed the city and led to the abandonment of the area. isotope records show decadal-scale, pseudo-periodic fluctuations related to climatic variations. the study was facilitated by using cross wavelet spectral analysis to evaluate the most powerful frequencies of oscillation. air temperature seems to play an important role in influencing the data records; the fluctuations, which seem related to this factor, show periods around 30 and 65 years. whereas 128 fayek a. et al. fig. 2 panel (a) presents the δ13c (cyan full line, left axis) and δ18o (blue full line, right axis) time series for channel b. panel (b) presents the δ13c (orange full line, left axis) and δ18o (red full line, right axis) time series for channel c. panel (c) presents the global crosswavelet spectrum (gxws) between δ13c and δ18o in terms of phase (dash line) and amplitude (full line) for channel b (blue lines) and channel c (orange lines). higher frequency pulses at periodicities of about 7, 10, 12 years seem to be related to the shallow aquifer dynamics. the sequence b shows that climatic oscillations with periods around 50 years can be attributed to the filtering of the aquifer system to air temperature periodic variations. acknowledgments the authors wish to thank the italian archaeological mission at hierapolis (maier) for having made the access to the archaeological site of hierapolis possible. references andrews j.e. (2006) palaeoclimatic records from stable isotopes in riverine tufas: synthesis and review. earth-science reviews, 75(1-4), 85-104. dilsiz c. (2006) conceptual hydrodynamic model of the pamukkale hydrothermal field, southwestern turkey, based on hydrochemical and isotopic data. hydrogeology journal, 14, 562-572. di taranto i. (2015) la rete dei canali di travertino. in: nuovo atlante di hierapolis di frigia vii. cartogracartografia archaeologica della citta e delle necropoli, scardozzi g. (ed.), 63-69. grinsted a., moore j., jevrejeva s. (2004) application of the cross wavelet transform and wavelet coherence to geophysical time series, nonlinear processes in geophysics, 11, 561-566. grossmann a., morlet j. (1984) decomposition of hardy functions to square integrable wavelets of constant shape. journal on mathematical analysis, 15, 723-736. guyennon n., valerio g., salerno f., pilotti m., tartari g., copetti d. (2014) internal wave weather heterogeneity in a deep multi-basin subalpine lake resulting from wavelet transform and numerical analysis. advances in water resources, 71, 149161. hancock p.l., chalmers r.m.l., altunel, e., çakir z., becher-hancock a. (2000) creation and destruction of travertine monumental stone by earthquake faulting at hierapolis, turkey. in: the archaeology of geological catastrophes (mcguire w.g., griffiths d.r., hancock p.l., stewart i.s., eds.), geological society, london, special publication, 171, 1 -14. jimenez de cisneros c., caballero e., jimenez-lopez c. (2006) δ18o and δ13c of modern/ancient travertines from thermal spring (alicún de las torres, southern spain). geoacta, 5, 13-24. kele s., özkul m., fórizs i, gökgöz a., baykara m.o., alçiçek m.c., németh t. (2011) stable isotope geochemical study of pamukkale travertines: new evidences of low-temperature non-equilibrium calcite-water fractionation. sedimentary geology, 238 (1-2), 191-212. liu y., liang x.s., weisberg r.h. (2007) rectification of the bias in the wavelet power spectrum. journal of atmospheric and oceanic technology, 24, 2093 -2102. özkul m., varol b., alçiçek m.c. (2002) depositional environments and petrography of denizli travertines. mineral res. expl. bul., 125, 13-29. pentecost a. (2005) travertine. springer verlag, berlin, pp. 446. romano r., taddeucci a., voltaggio m. (1987) uranium-series dating of some travertines from the southwestern flank of mt. etna (sicily). rendiconti della società italiana di mineralogia e petrologia, 42, 249-256. scardozzi g. (2013) nuovi dati sulla topografia antica di hierapolis di frigia. rivista di studi di topografia antica, atta 23, 25-59. torrence c., compo g.p. (1998) a practical guide to wavelet analysis. bulletin of the american meteorological society, 79, 61-78. trémaux p. (1858) exploration archéologique en asie mineure, paris. 129 stable isotope stratigraphy of travertine sequences ms. received: may 15, 2018 final text received: may 21, 2018 130 amq30(1) 5 ghinoi 51-67 b available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 30 (1), 2017, 51-67 reappraisal of lateglacial stadials in the eastern alps: the case study of valparola (eastern dolomites, italy) alessandro ghinoi, mauro soldati department of chemical and geological sciences, university of modena and reggio emilia, modena, italy corresponding author: a. ghinoi <alessandro.ghinoi@unimore.it> abstract: this study aims to be a reappraisal of the lateglacial stadials of the dolomites. this has been accomplished by investigating the stadial moraine deposits in the pilot area of valparola, in the light of the most recent techniques to reconstruct paleo-glaciers and to calculate their equilibrium line altitude (ela). the use of these techniques in valparola could rely on a detailed geomorphological survey, in turn aided by the analysis of a lidar dem. the results obtained, in terms of stadial attribution, have been compared to those obtained by a previous author, the last one to study the lateglacial of the area already half a century ago. the comparison has allowed to verify how much improvement these techniques may offer to the knowledge of the local lateglacial and their feasibility to extend the analysis to wider areas. some knowledge gaps have also been highlighted, which should be taken into account in further studies. the analysis procedure tested in valparola is proposed as a possible reference for the reappraisal of the lateglacial over the whole dolomites. possibly, this could stir up new attention towards the study of the lateglacial over the alps, for which a comprehensive picture is still lacking. keywords: glacial landforms, lateglacial stadials, paleo-ela, dolomites, italy. 1. introduction half a century has passed since the publication of the milestone study on the stadial moraine deposits of the dolomites by g.b. castiglioni (1964). the study had the great merit to give a first overall framework of the lateglacial of a large portion of the alpine region, with important implications for its paleo-environmental reconstruction. the scale of the study, however, did not enable the detailed identification of glacial landforms and reconstruction of the respective paleo-glaciers. despite progresses of methods to reconstruct paleo-glaciers and to calculate equilibrium line altitudes (ela) of current and former glaciers, the study has never been updated. the detailed reconstruction of paleo-glaciers (sissons, 1974; porter, 1975; porter & orombelli, 1982; carr & coleman, 2007; ben & hulton, 2010; pellitero et al., 2016) has become increasingly important for calculating the respective ela, the essential element for the relative dating of lateglacial readvances. also the approaches to obtain the ela of current and paleo-glaciers have undergone a remarkable evolution (sissons, 1974; porter, 1975; sissons & sutherland, gross et al., 1977; meierding, 1982; furbish & andrews, 1984; kerschner, 1990; torsnes et al., 1993; benn & gemmell, 1997; benn & lehmkuhl, 2000; benn et al., 2005; osmaston, 2005; rea; 2009). lastly, the possibility to assign absolute dates to the glacial deposits through 14c and, increasingly in the last decades, through cosmogenic nuclides, allows to constrain the classic stadials – in turn frequently modified through time (penck & brückner, 1909; von klebelsberg, 1948; 1950; maisch, 1982; van husen, 1997; 2000; ivy-ochs et al., 2008; heiri et al., 2014) – within gradually more precise temporal bounds (ivy-ochs et al., 2006; 2008; 2009). the aim of this study is to investigate the stadial moraine deposits of the dolomites within the pilot study area of valparola, in the light of the most advanced techniques to reconstruct paleo-glaciers and paleo-elas (benn & hulton, 2010; osmaston, 2005; rea, 2009; pellitero et al., 2015; 2016), which can also be easily implemented within geographical information systems. the research, by comparing the outputs achieved with castiglioni’s interpretations, has also allowed to test how much improvement these techniques may offer to the reconstruction of the local lateglacial and to highlight the knowledge gaps still to be filled for their full applicability. some considerations will be made on the use of absolute dating in the specific geological and geomorphological conditions of the study area, which apply to other areas in the dolomites. the comparison with castiglioni’s results within this small pilot area aims to be an attempt to stir up a renewed attention towards the study of the lateglacial, for which a comprehensive picture is still lacking over the alpine region. the procedure adopted here, along with 52 ghinoi a., soldati m. the uncertainties that have come out from its application in valparola, is proposed as a possible reference for the reconstruction of the lateglacial in other areas. 2. the study area the study area is located within the upper badia valley, at the boundary between the autonomous province of bolzano and the belluno province (veneto region), in the eastern dolomites, italy (fig. 1) (see marchetti et al., 2017). the main orographic features bounding the area are, to the north, piz dles conturines (3064 m), to the south, mount setsas (2571 m) linked to the valparola pass (2187 m), to the east monte de lagazuoi (2718 m) and, to the west, peak les pizades (2255 m) and the torrent rü de störes. the minimum altitude is at locality armentarola (1615 m) while the maximum is at piz dles conturines (3064 m). the extent is about 20 km2. the area lies within the basin of the adige river, next to the watershed of the piave river basin. the drainage network is composed by two main torrents, the rü sciarè and the rü de col dai furns, receiving inputs from many ephemeral streams. water courses are principally fed by rainfall and snowmelt waters and, at the contact between highly fractured dolomite rocks and the underlying marly and clayey rocks, numerous springs originate, scattered all over the basin at a mean altitude of 2000 m. the climate can be classified as “temperatecold” (class “dfc” according to köppen, 1931, as modified by pinna, 1970) through the series of mean monthly air temperatures and precipitations recorded from 1994 to 2014 at the meteorological station of san cassiano (1545 m). the station can be assumed as representative for the valparola’s climate, as the san cassiano valley is the continuation towards north-west of valparola and the distance between the village and the study area about 3 km. winter months have the lowest values of mean precipitations, around 25 mm, and they coincide with the period of snow cover. the rocks outcropping in the area are of sedimentary origin and range from the upper ladinian to the norian. the depositional environments are coral reefs and back-reefs, deep-sea basins, marine margins (paralic) and carbonaceous tidal planes (cf. bosellini, 1996). the mountain groups of mount setsas, piz dles conturines and monte de lagazuoi are mainly formed by massive or stratified dolomites from the mediumupper triassic (dolomia cassiana and dolomia principale formations), with brittle mechanical behaviour and, secondarily, by marls and silts from the ladinian and carnian (pordoi, heiligkreutz and travenanzes formations), with ductile behaviour. the slopes at the cliffbase of the previously cited groups are formed by complex lithologies, composed by pyroclastic sandstones and siltstones from the medium triassic (wengen formation) and by sequences of calcarenites, marls and silts form the medium-upper triassic (s. cassiano formation) (cf. brandner et al., 2007). from the geomorphological point of view, valparola has well preserved lateglacial moraine deposits, despite slope processes have partly hid the till and the glacial landforms since the retreat of the last glaciers (cf. soldati et al., 2004, 2006; soldati & borgatti, 2009; borgatti & soldati, 2010; panizza et al, 2011; ghinoi et al., 2014; marchetti et al., 2017). the oldest traces left by glaciers can be attributed to the lgm, when all valleys of the dolomites were covered by ice until high elevations, sometimes even greater than the current mountain passes (penck & brückner, 1909; mutschlechner, 1933; b. castiglioni, 1940; von klebelsberg, 1948; g.b. castiglioni, 1964; cantelli & vai, 2004). the rounding of mount setsas crest, in the tract from mt. castello to valparola pass, and the saddle-like form of the pass itself represent the most evident traces of a glacier transfluence from the upper badia valley towards south, to the andraz valley and the confluence with the cordevole paleo-glacier. mutschlechner (1933) sustained the hypothesis that during the lgm the upper badia valley fig. 1 location of study area, between the autonomous province of bolzano/ south tyrol and the belluno province (veneto region), dolomites, italy. ____________________________________________________________________ >>>>>> fig. 2 distribution of glacial and periglacial landforms and deposits in the study area. 1: armentarola frontal moraine complex; 2: malghe valparola lateral-frontal moraine; 3: dlira i frontal moraine; 4: dlira ii frontal moraine; 5: pudres frontal moraine. white lines: isolines (50 m equidistance). 53 reappraisal of lateglacial stadials in the eastern alps was reached by a glacier tongue whose feeding area was within the pusteria valley, extending with an e-w direction some 30 km north. according again to mutschlechner (1933), the mount setsas ridge, perpendicular to the flow direction of the glacier tongue, may have acted as a main obstacle to the flow itself, together with the local ice masses on the puez-gherdenacia and sella groups on one side and those on the fanes grande, fanes piccola and monte de lagazuoi on the opposite side (fig. 1). mutschlechner (1933) stated that the southernmost evident traces left by the pusteria glacier tongue in the badia valley are represented by few scattered, small crystalline erratics found around the village of san cassiano and in the main depression of valparola, near malghe valparola (eisenofenalpe in his map). in the latter locality, where a series of w-e trending humps of well-polished clasts of different lithology and size can still be visible (fig. 2), mutschlechner (1933) found a fist -size quartz stone that he took as a proof for the southernmost advance of the pusteria glacier inside the badia valley. this may not necessarily imply the attribution of the deposit to an lgm glacier; more likely, its genesis can be related to a local valley glacier confined within the valparola, which reworked former lgm deposits. although not of crystalline origin, highly rounded pebbles and small blocks of dolomite and calcarenite, found at elevations ranging from 1970 to 2000 m (fig. 2), call for the presence of a glacier occupying the whole valparola. the elevation of the deposits and the more rounded clasts compared to all the other moraine deposits of the valley, lead to hypothesize their chronostratigraphic attribution to the lgm. their preservation seems to have been favoured by their position on top of two stable and gently sloping structural surfaces whose height was likely never reached by successive stadial glaciers. at the onset of the lateglacial, roughly around 19 ka (klasen et al., 2007), the ice tongues within the main alpine valleys were essentially stagnant and downfig. 3 frontal moraines and their stadial attribution as from g.b. castiglioni (1964), drawn on the lidar dem for this study. tab. 1 stadial classifications for the alpine lateglacial based on ela-depression ranges (in metres) from different authors. 1: limit values of ela depressions partly revised by g.b. castiglioni (1961). 2: in ravazzi et al., (2014), for the garda amphitheatre: 16.4±0.16 to 15.5±0.16 cal ka bp. 3: in federici et al., (2008) for the maritime alps: mean 10be age of 11.3±0.4 ka. 4: for the southern alps the same age of 21 cal ka bp is taken as the end of the last lgm advance for the tagliamento amphitheatre (“conodusso maximum advance” in monegato et al., 2007). (s): southern chains closer to the adriatic sea (kerschner et al., 1999; kerschner & ivy-ochs, 2008); (smd): south of alpine main divide (kerschner et al., 2000); (t): at type locality (ivy-ochs et al., 2008). 54 ghinoi a., soldati m. wasting, while in the eastern alps only small local glaciers were active (ivy-ochs et al. 2008). it is likely that during this period the whole valparola was still occupied by a local ice tongue, with lgm inherited ice just at the bottom of the ice mass. the reconstruction of the valley’s paleo-glacier evolution during the lateglacial by g.b. castiglioni (1964) (fig. 3) shows that most of the frontal moraine arcs relate to the gschnitz stadial and are quite close to the accumulation areas of the respective glaciers. going further valleyward, two arcs were attributed to the sciliar stadial, with which the author replaced the bühl stadial following von klebelsberg (1948). the lowest arc in altitude was interpreted as not referable to any stadial (in this case probably comprised between the lgm and the sciliar stadial). more recently, masini (1998) identified, for the nearby fanes grande and fanes piccola areas, more moraine features than those present in the map of lateglacial stadials by g.b. castiglioni (1964) and classified them from the gschnitz to the lia, adding also the egesen stadial which, according to g.b. castiglioni (in leonardi, 1967), is not present in the dolomites. 3. materials and methods the lateglacial evolution of valparola has been reconstructed by calculating the ela of the local paleoglaciers. the difference between the assumed local-lia ela and the calculated paleo-ela (the so called “ela depression”) allowed to attribute each paleo-glacier to a specific lateglacial stadial, according to the most recent stadial classification suggested for the alpine region (ivy -ochs et al., 2008; heiri et al., 2014) and italian alpine valleys (federici et al., 2008, 2012; monegato, 2102; colucci et al., 2014): “gschnitz”, “clavadel/senders”, “egesen” and kartell” (see table 1). to accomplish this, a detailed geomorphological survey has been undertaken, focusing the attention to the glacial deposits and landforms, but also to the abundant landslide deposits which often mask the glacial landforms or sometimes mimic their shape. the survey has been aided by the interpretation of aerial photographs and the boundaries of mapped features could be refined by the analysis of a high-resolution (1.5x1.5 m) lidar digital elevation model (dem) made available by the autonomous province of bolzano and of an even higher-resolution (1x1 m) lidar dem freely made available for the dolomites as wms service by the italian ministry of environment, land and sea. 3.1. paleo-glacier surface and paleo-ela reconstructions the procedure used in this study to calculate the paleo-ela of glaciers in the valley can be described as follows. 1) the theoretical longitudinal glacier surface profiles (from now on “longitudinal profiles”) have been modelled using the method by benn & hulton (2010) within the gis-integrated tool by pellitero et al. (2016), implementing the steady-state model which assumes a “perfectly plastic” ice rheology. altitude of the frontal moraine and topography derived from the dem were used as input data, although having no lateral moraine to validate the output surfaceprofiles. as for the basal shear stress given by the sliding of the glacier on the bedrock surface, the value of 50 kpa has been assigned to the portion of the glacier over the flat and wide valley bottom, while the value of 100 kpa has been assigned to the remaining portion, as suggested by pellitero et al. (2016). as valparola’s paleo-glaciers were valley glaciers, whose flow movement was therefore conditioned also by the side-drag along the valley sides, the “shape factor” was also introduced and calculated at several points along the longitudinal profile. 2) the hypsometry of each paleo-glacier tongue is then reconstructed thanks to the ice thickness calculated in step 1 and corrected by the “shape factor”. hypsometry is the primary input for the osmaston (2005) method with which the paleo-ela can be calculated in an iterative way with the “area x altitude balance ratio method” (aabr), assuming paleo-glaciers at hypothetical balanced state. the br is the ratio between the linear slopes of the mass balance/altitude curves above and below the ela. for our study area we have used a balance ratio (br) of 1.6, which is the mean value found by rea (2009) for current glaciers of the european alps. the same ratio has been used also in the maritime alps by federici et al. (2012). 3) we have also performed a parametric analysis, looking at the change of the reconstructed paleo-ela varying the br value within the confidence interval of the mean 1.6 found in rea (2009) (i.e., ±0.6). 3.2. reconstruction of ela depressions and stadial attribution since the seminal studies by penck & brückner (1909), different authors have tried to reconstruct, also for this sector of the dolomites, the paleo-glacier evolution during the lateglacial by calculating the difference between the ela of paleo-glaciers and the “present-day” 1) (or lia’s) ela. the ela is the altitude corresponding to a mass budget equal to zero. the method is clearly qualitative, but it has one main advantage: it allows to compare paleo-glacier reconstructions over large-scale areas. like all models, it has also drawbacks: the uncertainties related to the reconstruction of paleo-glacier surfaces; the difficulty in selecting the reference ela for certain areas with peculiar topographic and/or climatic conditions. the latter is the case of the dolomites where, in our knowledge, no ela calculation exists neither for the current time, nor for the lia. up to now, the terminology of the lateglacial stadials has undergone frequent changes and even their ela -depression ranges have been revised, making it difficult to compare results achieved in different time periods. looking at tab. 1, it is possible to appreciate the differences between some stadial classifications selected from literature studies which are “geographically close” to our study area. _____________ 1) the term “present-day” is referred to the time period close to when the studies were carried out, therefore the reference elas are likely different from the current (2017) one. 55 reappraisal of lateglacial stadials in the eastern alps as it can be argued from tab. 1, most of the stadial names are persistent through time, while the range of their ela depression shows sometimes strong differences. the term “bühl stadial”, first introduced by penck & brückner (1909, bd.1), was replaced by the “sciliar stadial” (or “schlernstadium”) in von klebelsberg (1948) and never used again until now, except in masini (1998). von klebelsberg (1950) added the “steinach stadial” (still present in van husen, 2000) between the sciliar and the gschnitz ones. the most recent classification, by ivy-ochs et al. (2008), has the “clavadel/ senders stadial” between the gschnitz and daun ones, plus the “kartell stadial” between the egesen and the lia. which ela to select as reference for calculating the ela depression is another critical issue for the comparison of stadials between different authors: most of them have used the “present-day” ela (see annotation 1), and only recently the lia’s ela is becoming the standard reference (gross et al., 1977; maisch, 1982). penck & brückner (1909, bd.1) used the “heute” schneegrenze (variable from valley to valley) as the reference ela: considering the values they found in different valleys (in the north-eastern alps), it could have ranged from 2500 to 2800 m. von klebelsberg (1947) identified the “present-day” ela for the sella group and surrounding areas around 2950 m. g.b. castiglioni (1961) used the “present-day” ela that marinelli (1910) calculated around the sella group, i.e., again 2950 m. masini (1998), using three different methods for calculating the “present-day” ela from the veneto region’s glaciers, obtained three different elas: 2820 m, 2760 m and 2580 m, although the ela at year 1998 should have been in the 2800-2900 m range (as stated by masini), somehow close to the elas estimated by von klebelsberg (1947) and by marinelli (1910). ivy-ochs et al. (2008) took as reference the lia’s ela, since it is considered the holocene maximum glacier advance in most catchments of the alps and more reliable to determine than the “present-day” ela, mainly due to the scarcity of current glaciers in the alps with known current ela (gross et al., 1977). for this study we have selected the local lia’s ela as reference for the ela-depression calculation, in order to compare the results with the most up-to-date classification for the alps by ivy-ochs et al. (2008), which is also associated to a preliminary chronology based on radiocarbon and cosmogenic-nuclides dating. nevertheless, as previously stated, we have used also the “present-day” ela by g.b. castiglioni (1961), in order to compare his findings with ours. having no reference publications to rely on for the local lia’s ela, we considered as local “present-day” ela the range of values reported in masini (1998), i.e., 2800-2900 m, subtracting some 100 m, being that the average depression value found in literature between the lia’s and the “present-day” ela (kerschner et al., 1999 for the gschnitz valley; kerschner et al., 2000; pelfini, 1994 for ortles-cevedale glaciers; masini, 1998 for altopiani di fanes, sennes e fosses). the “presentday” ela values, ranging from 2800 to 2900 m, find a partial validation in the glacieret currently present 2.5 km east of the study area, in the ciadin de fanes corrie, close to peak piza sud (fig. 1), its altitude ranging between 2750 and 2920 m (classified by the world glacier inventory with the code it4l00023005). in the recently published “the new italian glacier inventory” (smiraglia & diolaiuti, 2015), the glacieret is described as “split into many ice bodies, not easily recognizable and almost totally debris-covered”. the validation is only partial because glacierets are not suitable for calculating equilibrium line altitudes, laying most of the times completely within the ablation zone. anyhow, the upper limit of 2900 m is likely to be the closest to the local “present-day” equilibrium line. in baratto et al. (2003) the present day ela for the dolomites is reported, without supporting data, at 2850 m. recently, an analysis has been carried out on the extension of glaciers from the lia to the present for the whole trento region (bertoni & casarotto, 2016). for the marmolada glacier, the lia’s frontal moraines have been precisely identified, at an average altitude of 2300 m. the calculation of the lia’s ela with the tools by pellitero et al. (2015; 2016) has given a value of 2757 m for the lia’s ela at marmolada. the value of 2972 m has been eventually found for the current glacier. this result reinforces the choice we have made in this study for a reference ela of 2800 m: the lower value of 2757 m found using the lia’s moraines can be explained considering the high inclination of marmolada mount (30-35° mean) and its uniform orientation to the north, which are two topographic factors that might favour the lowering of the ela. 4. results results of the lateglacial reconstruction are presented identifying each moraine arc with a progressive number reported in red in fig. 2 and the name of the closest locality, starting from the valley’s lowermost arc to the uppermost one, describing its main geomorphological characteristics and reconstructing the paleosurface of the glacier. ela-depression is then calculated and the stadial assigned to each paleo-glacier. 4.1. paleo-glacier and paleo-ela reconstruction (1) armentarola frontal moraine complex: northwestern sector of the study area, at the junction between torrent rü sciarè and torrent rü de störes, near locality “armentarola”, extending, in altitude, from 1614 to 1622 m. seven moraine ridges composed by dolomite blocks, partly immersed in a mainly coarse matrix and of mean ne-sw direction, have been identified at locality armentarola. they form a frontal moraine complex of a glacier likely hosted within the entire valparola valley, probably with ice contributions from the plateau of monte de lagazuoi and from the alpe di fanes piccola. the longitudinal topographic profiles used to reconstruct the glacier surface have been traced following the main depressions of the valley up to the uppermost ridges bordering the valley. to account for the side-drag along the valley sides (shape factor), cross profiles have been traced at several points along the longitudinal profiles, in order to account for the change of the shape factor itself along the longitudinal profile 56 ghinoi a., soldati m. from the frontal moraine until the watershed. as it can be seen by the modelled surface, the glacier’s accumulation area can be identified with the entire valley, extending laterally towards plan da lega in the ablation zone, where later on, thick debris-flow cones and alluvial deposits have masked all previous till and glacial landforms. worth noticing are the two gentle-sloping areas west of plan de lot and at störes, ice free from the modelling result. these areas match quite well with the findings of highly rounded blocks which we attributed to earlier phases of the local glacial history, possibly lgm related, outlined in fig. 2. the armentarola glacier ela has been calculated at 2000 m, identified by the red line in fig. 4. within the rea’s (2009) confidence interval around the br value of 1.6, the ela ranges from 2040 (br=1) to 1980 (br=2.2), i.e. +40 and -20 m from the elabr=1.6. (2) malghe valparola frontal moraine: central depression of valparola, where torrent rü de pudres becomes torrent rü de col dai furns, near locality “malghe valparola”, at 1750 m mean altitude. a complex of five moraine ridges, composed by dolomite blocks of metric diameters with no significant finer matrix, has been identified from malghe valparola to fontane nere (fig. 5), with a mean w-e trend. the altitude of the ridge tops is the same for the three parallel ridges at malghe valparola and it is only a few metres higher than the mean valley bottom in the same sector. a sw-ne trend characterizes the ridge on the left side of the torrent rü de pudres. its mean altitude is around 1760 m and its orientation suggests to interpret it as a lateral-frontal moraine built by a glacier coming from the valley stretching from the borat-vallone pudres areas to malghe valparola. the similar altitude (among them) of the three lowermost w-e-trending ridges and their relative proximity has led to interpret them as remnants of an ablation till, dissected by successive gully erosion, instead of lateral moraines. the uppermost fifth ridge appears to be another elongated remnant of the same ablation till. this last proxy led to hypothesize the presence of another glacier branch coming from passo valparola to malghe valparola, here joining with the first one. this is why two longitudinal topographic profiles were used to reconstruct the glacier surface profile: one has been traced following the main depression joining malghe valparola with valparola pass, the second one, joining the areas of borat and vallone pudres with malghe valparola. other minor longitudinal profiles, joining with the main one in the borat area, have been traced hypothesizing the presence of an ice mass also within the main concavity of mount setsas. to account for the side-drag along the valley sides (shape factor), cross profiles have been traced at several points along the longitudinal profiles, in order to account for the change of the shape factor itself along the longitudinal profile from the frontal moraine until the watershed. at this moment in time, the valparola glacier was composed by two main tributary glacial bodies, one confined within the passo valparola-malghe valparola valley, and one confined within the bowl-shaped area of vallone pudres-borat-prà de ciàmena. regarding the lateral-frontal moraine at malghe valparola, worth noticfig. 4 modelled armentarola paleo-glacier, represented in semi-transparent blue, with its frontal moraines (violet polygons and ridge in yellow) and paleo-ela (br = 1.6, red line, br=1, green line, br=2.2, orange line). surface of paleo-glacier reconstructed using the “glare” toolbox for arcgis by pellitero et al. (2016). blue isolines are for the paleo-glacier’s surface. white isolines are for the current topography. paleo-ela calculation performed using the “ela calculation” toolbox for arcgis by pellitero et al. (2015). 57 reappraisal of lateglacial stadials in the eastern alps ing is the fact that it is adjacent to a wide block-slide deposit which probably moved from the les pizades slope to the west. this observation leads to infer a relative dating of the landslide which should have occurred before the glacier readvance in the malghe valparola area. the presence of the landslide deposit must have narrowed considerably the valley of rü de pudres, confining the ice mass within a rather small-extent area. this may have favoured the mechanical stabilization of the landslide deposit for as long as the ice mass was in place. nowadays, the left slope of the rü de pudres valley is continuously subject to shallow earth slides. the malghe valparola’s glacier ela has been calculated at 2091 m, identified by the red line in fig. 5. fig. 5 modelled malghe valparola paleo-glacier, represented in semi-transparent blue, with its frontal moraines (violet polygons and ridge in yellow) and paleo-ela (br = 1.6, red line, br=1, green line, br=2.2, orange line). surface of paleo-glacier reconstructed using the “glare” toolbox for arcgis by pellitero et al. (2016). blue isolines are for the paleo-glacier’s surface. white isolines are for the current topography. paleo-ela calculation performed using the “ela calculation” toolbox for arcgis by pellitero et al. (2015). fig. 6 modelled dlira i paleo-glacier, represented in semitransparent blue, with its frontal moraines (violet polygons and ridge in yellow) and paleo-ela (br = 1.6, red line, br=1, green line, br=2.2, orange line). surface of paleo-glacier reconstructed using the “glare” toolbox for arcgis by pellitero et al. (2016). blue isolines are for the paleo-glacier’s surface. white isolines are for the current topography. paleo-ela calculation performed using the “ela calculation” toolbox for arcgis by pellitero et al. (2015). fig. 7 modelled dlira ii paleo-glacier, represented in semitransparent blue, with its frontal moraines (violet polygons and ridge in yellow) and paleo-ela (br = 1.6, red line, br=1, green line, br=2.2, orange line). surface of paleo-glacier reconstructed using the “glare” toolbox for arcgis by pellitero et al. (2016). blue isolines are for the paleo-glacier’s surface. white isolines are for the current topography. paleo-ela calculation performed using the “ela calculation” toolbox for arcgis by pellitero et al. (2015). 58 ghinoi a., soldati m. following the main longitudinal depressions joining the back-arcs with valparola pass and surrounding areas. to account for the side-drag along the valley sides (shape factor), cross profiles have been traced at several points along the longitudinal profiles, in order to account for the change of the shape factor itself along the longitudinal profile from the frontal moraine until the watershed. at the time the frontal arcs of dlira i and dlira ii formed, the valparola ice masses seem to have been definitely separated, with a main glacier tongue stretching from valparola pass to the dlira i-ii frontal arcs (fig. 6 and 7) and a minor ice tongue contained within the pudres valley (see further on in the text) and possibly, partly in the borat and adjacent areas eastward. nevertheless, the lack of glacial landforms do not allow to infer any ice extent for the latter areas. the feeding area of the main tongue is confined to the slopes surrounding the pass, probably with no substantial contributions from the north-facing slopes. the clear sequence of recessing moraine ridges allows to argue that the ice masses had more favourable conditions for their preservation in this part of the valley than on mount setsas slope. the latter, in fact, is wide, gently inclined, with not much shade effect from surrounding peaks, and thus more within the rea’s (2009) confidence interval around the br value of 1.6, the ela ranges from 2111 (br=1) to 2071 (br=2.2), i.e. +20 and -20 m from the elabr=1.6. (3) – (4) dlira frontal moraine sequence (i-ii) – (i): secondary valley stretching almost w-e from malghe valparola to valparola pass, a few metres uphill from fontane nere springs, at 1873 m mean altitude; (ii): secondary valley stretching almost w-e from malghe valparola to valparola pass, at locality “pra de dlira”, just a few metres west of the provincial road nr. 24, at 2004 m mean altitude. a series of two concentric moraine arcs, stretching sw-ne with some 400 m length between malghe valparola and prà de dlira, is formed by dolomite blocks with metric diameters, highly weathered by karst action and largely masked by trees and underwood. uphill, two small back-arc plains are formed by finer colluvium (gravel, mostly) transported by running waters and by debris-flows. these arcs may represent a sequence of stadial readvances quite close to each other in time and they lie within a wide ablation-till deposit occupying the entire depression from valparola pass to malghe valparola. the longitudinal topographic profiles used to reconstruct the two glacier surface-profiles have been traced fig.8 left: distribution of yearly global solar radiation (intensities increasing from dark blue to dark brown). right: distribution of areas with slope angles above 30° (slope angles increasing from green to red). 59 reappraisal of lateglacial stadials in the eastern alps subject to direct solar radiation and ablation (fig. 8, left). on the other hand, the valparola pass malghe valparola valley is narrower, partly shaded by a crest line to the south and richer in sediment production (from rock falls and debris flows) which could form an iceprotecting surficial moraine. moreover, the head of the valparola pass malghe valparola valley appears to be more prone to avalanche events than the setsas valley, as it can be deduced by the spatial distribution of slopes with inclination higher than 30° (fig. 8, right). the dlira i-ii’s glacier elas have been calculated at 2087 and 2169 m respectively, identified by the dashed lines in fig. 6 and fig. 7. within the rea’s (2009) confidence interval around the br value of 1.6, the ela ranges, respectively, from 2107 (br=1) to 2087 (br=2.2) and from 2189 (br=1) to 2169 (br=2.2), i.e. +20 and -0 m from the elabr=1.6 in both cases. (5) pudres frontal moraine: at the outlet of the secondary valley named “vallone pudres”, in the southwestern sector, west of mount setsas, at 2154 m mean altitude. a well preserved frontal moraine arc has been identified at the outlet of the suspended valley of vallone pudres, on the western side of mount setsas. the arc, whose lenght is some 100 m, is composed by dolomite blocks with metre and sub-metre diameters within a gravel-to-sandy matrix, almost completely covered by grass and musk. the longitudinal topographic profile used to reconstruct the pudres glacier surface-profile has been traced following the main depression joining the valley’s headwall and the moraine arc. to account for the side-drag along the valley sides (shape factor), cross profiles have been traced at several points along the longitudinal profiles, in order to account for the change of the shape factor itself along the longitudinal profile from the frontal moraine until the watershed. based on geomorphological evidence, the narrow vallone pudres valley is likely to have hosted the last readvance for the whole valparola. here, the valley altitude, from 2000 m to 2500 m, its narrow shape, northward orientation and the shade effect of the surrounding mountain peaks created favourable conditions for the permanence of ice while, at the same time, the rest of valparola was almost entirely ice-free. contribution from avalanching is relatively high too, especially from the western slope (fig. 8, right). the pudres’s glacier ela has been calculated at 2327 m, identified by the red line in fig. 9. within the rea’s (2009) confidence interval around the br value of 1.6, the ela ranges from 2327 (br=1) to 2307 (br=2.2), i.e. +0 and -20 m from the elabr=1.6. the paleo-elas calculated for all valparola’s glaciers are summarized in tab. 2. 4.2. stadial attribution and comparisons with previous authors analysing the comparison table for ela’s depressions (tab. 3), the difference between the paleo-ela calculated for the armentarola glacier and the hypothefig. 9 modelled pudres paleo-glacier, represented in semitransparent blue, with its frontal moraines (violet polygons and ridge in yellow) and paleo-ela (br = 1.6, red line, br=1, green line, br=2.2, orange line). surface of paleo-glacier reconstructed using the “glare” toolbox for arcgis by pellitero et al. (2016). blue isolines are for the paleo-glacier’s surface. white isolines are for the current topography. paleo-ela calculation performed using the “ela calculation” toolbox for arcgis by pellitero et al. (2015). tab. 2 ela calculations for the valparola paleo-glaciers, performed using the toolbox for arcgis by pellitero et al. (2015). aabr: area x altitude balance ratio method (used in this study). 60 ghinoi a., soldati m. sized local lia’s ela (last column) at 2800 m, allows us to place that readvance phase between the lgm and the gschnitz stadial, if we consider the classification by ivy-ochs et al. (2008). the elas for malghe valparola, dlira-i and dlira-ii glaciers place those glacier readvances within the gschnitz stadial, if the values of 700 m and 650 m are taken as the maximum and minimum values for the gschnitz-stadial’s ela-depression range. the ela depression for the malghe valparola and dlirai glaciers is close to the upper value, while that of the dlira-ii glacier is close to the minimum one. according to kerschner & ivy-ochs (2008), the ela depression for the gschnitz stadial could have been even greater for the southern alpine chains near the adriatic sea, reaching 1000 m; values of 900-1000 m have also been estimated for the northwards trending valleys of the carnian alps (kerschner & ivy-ochs, 2008). taking 1000 m as the upper value for the gschnitz’s ela-depression range would place also the armentarola glacier within the gschnitz stadial. the same ela-depression found with this study, following penck & brückner’s (1909) classification, would place the armentarola readvance between the bühl and the gschnitz stadials and the ones of malghe valparola, dlira-i and dlira-ii in the gschnitz. according to von klebelsberg’s (1948) classification, the armentarola readvance could have taken place during the sciliar, while the malghe valparola, dlira-i and dlira-ii readvances could have been within the steinach stadial. g.b. castiglioni (1961) classification would place the armentarola glacier readvance within the sciliar, while the ones of malghe valparola, dlira-i and dlira-ii within the gschnitz stadial. the classification used by masini (1998) would place all the glacier readvances, except the pudres one, between the bühl and the gschnitz stadials. regarding the pudres glacier readvance, the eladepression found with this study places it, following the ivy-ochs et al. (2008) classification, within the clavadel/ sanders stadial, while penck & brückner’s and von klebelsberg’s classifications would place it between the gschnitz and the daun stadials. g.b. castiglioni (1961) would place it within the gschnitz, while masini (1998) within the daun. comparison of the stadial attributions to valparola’s paleo-glaciers given by this study with those given using former authors’ classifications (fig. 10), despite the great differences between the adopted approaches, shows the clustering of attributions around common stadials. for the armentarola glacier we can see a pregschnitz time; the malghe valparola and dlira i-ii glaciers cluster quite well around the gschnitz stadial, while the pudres glacier is clearly post-gschnitz, clustering well around the clavadel/senders stadial. if we wanted to test the improvement given by the method here applied with respect to the castiglioni’s method, we would need to adopt the author’s parameters: reference ela altitude derived from marinelli (1910) and equal to 2950 m (first column in tab. 3) and stadial classification. before that, differences should be pointed out in the interpretation of some glacial landforms between this study and castiglioni’s. the author interpreted as a series of frontal moraines of the gschnitz stadial what we have identified as a rock glacier (fig. 2), near the valparola pass, thus not allowing any comparison. the frontal arc at plan de lot, assigned by g.b. castiglioni (1964) to the sciliar stadial, is here interpreted as a displaced rock mass due to gravity, while the frontal moraine, cut by the torrent rü sciarè in g.b. castiglioni (1964), has not been recognized in our study as such a landform. the ela-depression calculated with the method selected for this study, but using castiglioni’s reference ela and stadial classification, would place the armentarola glacier between the lgm and the sciliar stadial, confirming castiglioni’s result. the malghe valparola glacier would be placed within the sciliar stadial, again confirming the author’s assignment. the dlira-ii glacier (dlira-i was not identified by the author) would be placed between the sciliar and the gschnitz, while castiglioni assigned it to the gschnitz one. finally, the pudres glacier would be placed within the gschnitz stadial and this is again confirmed also by castiglioni. 4.3. valparola evolution since the end of the lgm throughout the lateglacial considering the mean height of 2000 m of the till found on the two stable and gently sloping structural surfaces, as described in section 2 and fig. 2, the lgm ice may have almost completely covered the valparola topography, leaving out, as nunatak, just the crest of les pizades, to the west. the evidence of a till totally composed by local lithologies confirms the theory by fig. 10 comparison of the stadial attributions to valparola’s paleo-glaciers given by this study with those given using former authors’ classifications. red lines: armentarola paleo-glacier; purple lines: malghe valparola paleo-glacier, dlira-i and dlira-ii paleo-glaciers; ochre lines: pudres palo-glacier. 61 reappraisal of lateglacial stadials in the eastern alps 62 ghinoi a., soldati m. <<<<< ________________________________________________________________________________ tab. 3 stadial attributions of valparola paleo-glaciers, based on different “present day elas” (table’s header) and according to stadial classifications proposed by different authors (last column to the right). the paleo-ela obtained by this study is in blue. the stadial attribution obtained by this study is in bold in the second column. the stadial attribution obtained using the methodology adopted for this study and castiglioni’s data is the one in bold in the first column. mutschlechner (1933) according to which the most surficial portion of the lgm ice, in this sector of the valley, was depleted in crystalline erratics. if we accept the hypothesis that valparola represented the southernmost reach of the val badia glacier, a left branch of the main glacier residing within the pusteria valley, during the lgm (mutschlechner, 1933), we can argue that with the climatic amelioration that followed the last expansion phase of the lgm, the ice flow switched direction, starting its northward dynamics which characterized the local valley glacier from the lateglacial onset until the clavadel/senders stadial, covering a time period that could span, roughly, from 19 ka to 15.5/16 ka (klasen et al., 2007; ivy-ochs et al., 2008). in this period, one glacier stagnation phase can be recognized, marked by the complex of seven frontal moraines classified between the lgm and the gschnitz stadial at armentarola. the first clear readvance phase occurred during the gschnitz stadial, when the local valley glacier was almost completely confined to the upper sectors of the valley, with the lower gschnitz moraine at malghe valparola and the upper gschnitz one at dlira-ii. after the gschnitz readvance phase, the whole accumulation area of valparola may have rapidly become almost ice-free, leaving just one ice body within the well shaded, narrow and deep hanging valley of vallone pudres. there, during the clavadel/senders stadial, the pudres glacier had a small readvance marked by a frontal moraine a little above the slope change between the hanging valley and the rü de pudres valley. the egesen and kartell stadials are absent in valparola. the identification of rock glaciers, extending down slope until some 2000 m, leads to hypothesize that during the egesen stadial (and maybe throughout the whole younger dryas), periglacial conditions characterized the valley. other authors have identified rock glaciers developing during the egesen stadial, indicating a lowering of the permafrost to 2000-1900 m. (kerschner, 1978; sailer & kerschner, 1999; frauenfelder et al., 2001). nowadays, active rock glaciers reach the lowest altitude at 2500 m, in the near valun de ciampestrin nw-facing valley (holzner, 2011), some 3 km ne from the eastern limit of valparola. therefore, the local depression of the permafrost lower limit between the younger dryas and now is around 500 m, 200 m, even lower than the value found in literature (ivy-ochs et al., 2009). at the onset of the holocene, the permafrost reached higher elevations than during the preceding colder stage (ivy-ochs et al., 2009), thus leading to hypothesize that the valparola’s rock glaciers were at that time already inactive. 5. discussion and conclusions the present study has shown how the reconstruction of the local paleo-glaciers and of their paleo-elas, performed taking advantage of the most up-to-date methodologies, has provided results that, in terms of stadial classification, match reasonably well with those obtained by g.b. castiglioni (1964), if his reference ela is used. this proves how the method adopted by g.b. castiglioni (1964) to reconstruct the ela of paleoglaciers adapting the methodology proposed by kurowsky (1891) is able to give results that are comparable to those achievable with much more sophisticated methods, at least in this study area. from this observation it could be deduced that the search for very detailed reconstructions of paleo-surfaces and of refined elacalculations, at least for small valley glaciers, my account for just a small percentage to the improvement of the lateglacial reconstructions. nevertheless, this conclusion cannot be generalized after a first test in a small area like valparola, and needs further validation, comparing the results over the whole territory covered by g.b. castiglioni (1964). the good integration of the tools by pellitero et al. (2015; 2016) within a gis platform has proved to drastically reduce the time of calculation for paleo-ela assessments over large-scale areas, therefore favouring the refinement of g.b. castiglioni’s study for the whole dolomites. a refinement that could also take advantage, within this study, of a more detailed topography and of recent advances in geomorphological interpretation. having selected, for our study, a reference ela which is 150 m lower than the one used by g.b. castiglioni (1964), has inevitably placed the paleo-glaciers of valparola within relatively younger lateglacial phases. therefore, it seems that more crucial than the reconstruction method of paleo-glaciers is the selection of the proper reference ela which, in our case, was only assumed, since no studies are known to us able to define the lia’s ela for the area. the lia’s ela is currently taken as the better reference for ela-depression calculations (gross et al., 1977, confirmed in ivy-ochs et al., 2008). nevertheless, the assumption we have made of a 100 m-lowering of the lia’s ela from the current ela is widely accepted and, anyhow, it should not introduce great variations in ela-depression calculations (and consequently in stadial attribution) with respect to a more accurately defined local-lia’s ela. in fact, even by using different stadial classifications, with different ela depression ranges and reference elas, we have shown that differences seem not that great, clustering results around common stadials. anyhow, we have reconstructed the lia’s ela from the nearby marmolada glacier thanks to results from a recent study (bertoni & casarotto, 2016), in order to cross validate our assumption, despite the peculiar topographic characteristics of 63 reappraisal of lateglacial stadials in the eastern alps the marmolada mount. the resulting 2757 m value fits reasonably well with the 2800 m value taken by us as reference for the ela-depression calculation, although we think that just one value cannot be sufficient for reconstructing the real lia’s ela for the area. therefore efforts should be put in identifying more areas where even approximate calculations of the lia’s ela can be performed, trying to achieve a sufficient number of values to interpolate. with respect to the balance ratio value used, we have tested how its change from 1 to 2.2 (i.e., the lower and upper confidence limits of the 1.6 value assigned by rea (2009) to the european alps) allows for just a +40/20 m maximum difference in the altitude of the equilibrium line of the paleo-glaciers, again not introducing substantial differences in the calculation of the depression line. contribution to the local accumulation zones by snow avalanching has been proved to be of not much relevance, with an avalanche ratio (hughes, 2008) around 0.21. solar radiation, on the other hand, seems to have played a major role in the mass balance of glaciers during the lateglacial, with well exposed areas prevailing on sheltered ones, thus favouring preferential ablation. both observations could explain the limited size of the local paleo-glaciers. the same gis integration of the tools by pellitero et al. (2015; 2016) can favour the statistical analysis of paleo-glaciers’ elas in morphologically different areas (in terms of size of accumulation basins, altitude range, solar exposure, avalanche susceptibility and debris cover). in our opinion, would the analysis be extended to the whole dolomites, we propose to maintain the “classic” lateglacial stadial classification, in its most recent formulation (ivy-ochs et al., 2008), above all to limit the number of local stadials which would make comparisons between different areas more complex; secondly, because stadials have a clear relationship with climatic phases at global scale (the gschnitz with heinrich event 1 and the egesen with the younger dryas). instead, the real effort should be put in the identification of the local lia’s ela, where geomorphological evidence is available or where good estimation can be made of its depression from the current ela. eventually, the stadials identified would need to be dated. cosmogenic-nuclide exposure dating of moraine rocks has still high costs if statistically sound results are to be achieved and, specifically for dolomite rocks, the method has still uncertainties (alfimov & ivy-ochs, 2009). moreover, the confidence intervals in cosmogenic-nuclide exposure dating are often comparable to the length of lateglacial stadials (from ±740 to ±1030 years in moran et al., 2016), creating doubts on which stadial the dated material belongs to. nevertheless, dating methods will quite likely improve their effectiveness while at the same time possibly lower their costs, allowing to constrain the relative dating results achieved so far. aknowledgemnts the paper is part of the prin 2010-11 miur project on the "dynamics of morphoclimatic systems as a response of global changes and induced geomorphological risks" (co-ordinator: c. baroni; research unit responsible: m. soldati). the research benefited from a visit in recently deglaciated areas of the tierra del fuego (patagonia) and discussions with dr. jorge rabassa and his collaborators on the field. references alfimov v., ivy-ochs s. (2009) how well do we understand production of 36cl in limestone and dolomite? quaternary geochronology, 4, 462-474. baratto a., ferraese f., meneghel m., sauro u. (2003) la ricostruzione della glaciazione wurmiana nel gruppo del monte grappa (prealpi venete). in: biancotti a., motta m. (eds.), risposta dei processi geomorfologici alle variazioni ambientali, glauco brigati, genova, 67-77. benn d.i., gemmell a.m.d. (1997) calculating equilibrium-line altitudes of former glaciers: a new computer spreadsheet. glacial geology and geomorphology. https://goo.gl/yco2zv. bennet m., glasser n. (2009) glacial geology. wileyblackwell, pp. 400. benn d.i., hulton n.r.j. (2010) an exceltm spreadsheet program for reconstructing the surface profile of former mountain glaciers and ice caps. computers & geosciences, 36, 605-610. benn d.i., lehmkuhl f. (2000) mass balance and equilibrium-line altitudes of glaciers in high-mountain environments. quaternary international, 65-66, 1529. benn d.i, owen l.a., osmaston h.a., seltzer g.o., porter s.c., mark b. (2005) reconstruction of equilibrium-line altitudes for tropical and subtropical glaciers. quaternary international, 138139, 8-21. bertoni e., casarotto c. (2016) estensione dei ghiacciai dalla fine della piccola età glaciale a oggi. rilevamento sul terreno, digitalizzazione gis e analisi. muse museo delle scienze, pp. 54. borgatti l., soldati m. (2010) landslides as a geomorphological proxy for climate change: a record from the dolomites (northern italy). geomorphology, 120, 56-64. bosellini a. (1996) geologia delle dolomiti. casa editrice athesia s.a.r.l., bolzano, pp. 192. brandner r., keim l., gruber a., gruber j. (2007) geologische karte der westlichen dolomiten carta geologica delle dolomiti occidentali 1:25.000. autonome provinz bozen südtirol provincia autonoma di bolzano alto adige. amt für geologie & baustoffprüfung ufficio geologia e prove materiali, kardaun/cardano (bz). cantelli l., vai g. (2004) legend. in: antonioli f., vai g. (eds.), litho-paleoenvironmental maps of italy during the last two climatic extremes: map 1, last glacial maximum (22 +2 ka cal bp) average air temperature of about 4.5°c lower than today : map 2, holocene climatic optimum (8 +1 ka cal bp) average surface air. museo geologico giovanni capellini, bologna, 4-8. carr s., coleman c. (2007) an improved technique for the reconstruction of former glacier mass-balance 64 ghinoi a., soldati m. and dynamics. geomorphology, 92(1-2), 76-90. carton a., bondesan a., fontana a., meneghel m., miola a., mozzi p., primon s., surian n. (2009) geomorphological evolution and sediment transfer in the piave river system (northeastern italy) since the last glacial maximum. gèomorphologie: relief, processus, environment, 3, 155-174. castiglioni b. (1940) l’italia nell'età quaternaria. in: touring club italiano (ed.), atlante fisico d’italia. milano, map 1:1.200.000. castiglioni g.b. (1961) i depositi morenici del gruppo adamello-presanella con particolare riguardo agli stadi glaciali postwürmiani. memorie degli istituti di geologia e mineralogia dell'università di padova, xxiii, pp. 216. castiglioni g.b. (1964) sul morenico stadiale delle dolomiti. memorie degli istituti di geologia e mineralogia dell'università di padova, 24, 1-16. colucci r., monegato g., žebre m. (2014) glacial and proglacial deposits of the resia valley (ne italy): new insights on the onset and decay of the last alpine glacial maximum in the julian alps. alpine and mediterranean quaternary, 27, 85-104. favilli f., egli m., brandova d., ivy-ochs s., kubik p., cherubini p., mirabella a., sartori g., giaccai d., haeberli w. (2009) combined use of relative and absolute dating techniques for detecting signals of alpine landscape evolution during the late pleistocene and early holocene. geomorphology, 112, 48-66. federici p.r., granger d.e., pappalardo m., ribolini a., spagnolo m., cyr a.j. (2008) exposure age dating and equilibrium line altitude reconstruction of an egesen moraine in the maritime alps, italy. boreas, 37, 245-253. federici p.r., granger d.e., ribolini a., spagnolo m., pappalardo m., cyr a.j. (2012) last glacial maximum and the gschnitz stadial in the maritime alps according to 10be cosmogenic dating. boreas, 41, 277-291. florineth d., schlüchter c. (2000) alpine evidence for atmospheric circulation patterns in europe during the last glacial maximum. quaternary research, 54, 295-308. forno m., gianotti f., racca g. (2010) significato paleoclimatico dei rapporti tra il glacialismo principale e quello tributario nella bassa valle della dora baltea. il quaternario, 23, 105-124. frauenfelder r., haeberli w., hoelzle m., maisch m. (2001) using relict rockglaciers in gis-based modelling to reconstruct younger dryas permafrost distribution patterns in the err-julier area, swiss alps. norsk geografisk tidsskrift, 55, 195202. furbish d.j., andrews j.t. (1984) the use of hypsometry to indicate long-term stability and response of valley glaciers to changes in mass transfer. journal of glaciology, 30(105), 199-211. ghinoi a., freddi r., pasuto a., soldati m. (2014) geomorphological analysis of the historic landslide of sottrù (badia valley, italy) reactivated on december 13, 2012. proceedings international conference “analysis and management of changing risks for natural hazards”, 18-19 november 2014, padua, italy, ap 19 1-8. gross von g., kerschner h., patzelt, g. (1977) methodische untersuchungen über die schneegrenze in alpinen gletschergebieten. zeitschrift für gletscherkunde und glazialgeologie 12(2), 223-251. heiri o., koinig k.a., spötl c., barrett s., brauer a., drescher-schneider r., gaar d., ivy-ochs s., kerschner h., luetscher m., moran a., nicolussi k., preusser f., schmidt r., schoeneich p., schwörer c., sprafke t., terhorst b., tinner w. (2014) palaeoclimate records 60–8 ka in the austrian and swiss alps and their forelands. quaternary science reviews, 186-205. holzner s. (2011) geologie des südlichen fanesgebietes östlich von st. kassian (südtiroler dolomiten) unter besonderer berücksichtigung der blockgletscher. leopold franzens universität innsbruck, institut für geologie und paläontologie, pp. 138. hughes, p.d.(2008) response of a montenegro glacier to extreme summer heatwaves in 2003 and 2007. geografiska annaler: series a, physical geography, 90, 259-267. ivy-ochs s., kerschner h., maisch m., christl m., kubik p.w., schlüchter c. (2009) latest pleistocene and holocene glacier variations in the european alps. quaternary science reviews, 28, 21372149. ivy-ochs s., kerschner h., reuther a., maisch m., sailer r., schaefer j., kubik p.w., synal h.-a., schlüchter c. (2006) the timing of glacier advances in the northern european alps based on surface exposure dating with cosmogenic 10be, 26al, 36cl and 21ne, in: siame, l.l., bourlès, d.l., brown, e.t. (eds.), in situ–produced cosmogenic nuclides and quantification of geological processes. geological society of america, paper 415, 43-60. ivy-ochs s., kerschner h., reuther a., preusser f., heine k., maisch m., kubik p.w., schlüchter c. (2008) chronology of the last glacial cycle in the european alps. journal of quaternary science, 23, 559-573. kerschner h. (1978) paleoclimatic inferences from late würm rock glaciers, eastern central alps, western tyrol, austria. arctic and alpine research, 10, 635-644. kerschner h. (1985) quantitative palaeoclimatic inferences from lateglacial snowline, timberline and rock glacier data, tyrolean alps, austria. zeitschrift für gletscherkunde und glazialgeologie, 21, 363369. kerschner h. (1990) methoden der schneegrenzbestimmung. in: liedtke, h. (ed.), eiszeitforschung. wissenschaftliche buchgesellschaft, darmstadt, 229-311. kerschner h., ivy-ochs s. (2008) palaeoclimate from glaciers: examples from the eastern alps during the alpine lateglacial and early holocene. global and planetary change, 60, 58-71. kerschner h., ivy-ochs s., schlüchter c. (1999) paleoclimatic interpretation of the early late-glacial glacier in the gschnitz valley, central alps, austria. 65 reappraisal of lateglacial stadials in the eastern alps annals of glaciology, 28, 135-140. kerschner h., kaser g., sailer r. (2000) alpine younger dryas glaciers as paleo-precipitation gauges. annals of glaciology, 31, 80-84. klasen n., fiebig m., preusser f., reitner j.m., radtke u. (2007) luminescence dating of proglacial sediments from the eastern alps. quaternary international, 164-165, 21-32. köppen w. (1931) grundriss der klimakunde. walter de gruyter, berlin, pp. 388. kuhlemann j., rohling e.j., krumrei i., kubik p., ivyochs s., kucera m. (2008) regional synthesis of mediterranean atmospheric circulation during the last glacial maximum. science, 321 (5894), 13381340. kurowski l. (1891) die höhe der schneegrenze mit besonderer berücksichtigung der finsteraarhorngruppe. geographische abhandlungen, 5(1), 115160. leonardi p. (1967) le dolomiti. geologia dei monti tra l’isarco ed il piave. volumi 1-2. manfredini ed., rovereto (tn), pp. 1019. maisch m. (1982) zur gletscherund klimageschichte des alpinen spätglazials, geographica helvetica, 37, 93-104. marchetti m., ghinoi a., soldati m. (2017) the dolomite landscape of the alta badia (northeastern alps): a remarkable record of geological and geomorphological history. in: soldati m., marchetti m. (eds.), “landscapes and landforms of italy”, springer, cham, 123-134. marinelli o. (1910) i ghiacciai delle alpi venete. memorie geografiche, 3-291. masini m. (1998) limite delle nevi perenni, oscillazioni frontali tardiglaciali e postglaciali e relazioni con il clima degli altopiani di fanes, sennes e fosses (dolomiti alpi meridionali). studi trentini di scienze naturali acta geologica, 73, 107-117. meierding, t.c. (1982) late pleistocene glacial equilibrium-line altitudes in the colorado front range: a comparison of methods. quaternary research, 18 (3), 289-310. menzies j. (2002) modern & past glacial environments. butterworth-heinemann, oxford, pp. 543. monegato g. (2012) local glaciers in the julian prealps (ne italy) during the last glacial maximum. alpine and mediterranean quaternary, 25, 5 -14. monegato g., ravazzi c., donegana m., pini r., calderoni g., wick l. (2007) evidence of a two-fold glacial advance during the last glacial maximum in the tagliamento end moraine system (eastern alps). quaternary research, 68, 284-302. moran a.p., ivy-ochs s., schuh m., christl m., kerschner h. (2016) evidence of central alpine glacier advances during the younger dryas–early holocene transition period. boreas, 398-410. mozzi p., ferrarese f., fontana a. (2013) integrating digital elevation models and stratigraphic data for the reconstruction of the post-lgm unconformity in the brenta alluvial megafan (north-eastern italy). alpine and mediterranean quaternary, 26, 41-54. mutschlechner g. (1933) geologie des gebietes zwischen st. cassian und buchenstein. (südtiroler dolomiten). jahrbuch der geologischen bundesanstalt, 83, 199-232. orombelli g., tanzi g., ravazzi c. (2004) glacier extent over the italian alps during the lgm. in: lithopalaeoenvironmental maps of italy during the last two climatic extremes: map 1, last glacial maximum (22 +2 ka cal bp) average air temperature of about 4.5°c lower than today: map 2, holocene climatic optimum (8 +1 ka cal bp) average surface air. museo geologico giovanni capellini, bologna, 23-24. osmaston h. (2005) estimates of glacier equilibrium line altitudes by the area×altitude, the area×altitude balance ratio and the area×altitude balance index methods and their validation. quaternary international, 138-139, 22-31. panizza m., corsini a., ghinoi a., marchetti m., pasuto a., soldati m. (2011) explanatory notes of the geomorphological map of the alta badia valley (dolomites, italy). geografia fisica e dinamica quaternaria, 34, 105-126. pelfini m. (1994) equilibrium line altitude (ela) variations recorded by ortles-cevedale glaciers (lombardy, italy) from little ice age to present. geografia fisica e dinamica quaternaria, 17, 197206. pellegrini g.b., albanese d., bertoldi r., surian n. (2005) la deglaciazione alpina nel vallone bellunese, alpi meridionali orientali. geografia fisica e dinamica quaternaria, suppl. vii, 271-280. pellitero r., rea b.r., spagnolo m., bakke j., hughes p., ivy-ochs s., lukas s., ribolini a. (2015) a gis tool for automatic calculation of glacier equilibrium-line altitudes. computers & geosciences, 82, 55-62. pellitero r., rea b.r., spagnolo m., bakke j., ivy-ochs s., frew c.r., hughes p., ribolini a., lukas s., renssen h. (2016) glare, a gis tool to reconstruct the 3d surface of palaeoglaciers. computers & geosciences, 94, 77-85. penck a., brückner e. (1909) die eiszeiten in den nördlichen ostalpen, bd.1. in: die alpen im eiszeitalter. chr. herm. tauchnitz, leipzig, pp. 393. pinna m. (1970) contributo alla classificazione del clima in italia. rivista geografica italiana, lxxvii, 129-152. porter s.c. (1975) equilibrium-line altitudes of late quaternary glaciers in the southern alps, new zealand. quaternary research, 5(1), 27-47. porter s.c., orombelli g. (1982) late-glacial ice advances in the western italian alps. boreas, 11(2), 125-140. ravazzi c., badino f., marsetti d., patera g., reimer p.j. (2012) glacial to paraglacial history and forest recovery in the oglio glacier system (italian alps) between 26 and 15 ka cal bp. quaternary science reviews, 58, 146-161. ravazzi c., pini r., badino f., de amicis m., londeix l., reimer p.j. (2014) the latest lgm culmination of the garda glacier (italian alps) and the onset of glacial termination. age of glacial collapse and 66 ghinoi a., soldati m. vegetation chronosequence. quaternary science reviews, 105, 26-47. rea b.r. (2009) defining modern day area-altitude balance ratios (aabrs) and their use in glacierclimate reconstructions. quaternary science reviews, 28, 237-248. reitner j.m. (2007) glacial dynamics at the beginning of termination i in the eastern alps and their stratigraphic implications. quaternary international, 164-165, 64-84. rossato s., monegato g., mozzi p., cucato m., gaudioso b., miola a. (2013) late qaternary glaciations and connections to the piedmont plain in the prealpine environment: the middle and lower astico valley (ne italy). quaternary international, 288, 8-24. rossato s., mozzi p. (2016) inferring lgm sedimentary and climatic changes in the southern eastern alps foreland through the analysis of a 14c ages database (brenta megafan, italy). quaternary science review, 148, 115-127. sailer r., kerschner h. (1999) equilibrium line altitudes and rock glaciers in the ferwall-group (western tyrol, austria) during the younger dryas cooling event. annals of glaciology, 28, 141-145. sissons j.b. (1974) a late-glacial ice cap in the central grampians, scotland. transactions of the institute of british geographers, 62, 95-114. sissons j.b., sutherland d.g. (1976) climatic inferences from former glaciers in the south-east grampian highlands, scotland. journal of glaciology, 17(76), 325-346. smiraglia c., diolaiuti g. (2015) il nuovo catasto dei ghiacciai italiani. ev-k2-cnr ed., bergamo, pp. 400. soldati m., borgatti l. (2009) paleoclimatic significance of holocene slope instability in the dolomites (italy). geografia fisica e dinamica quaternaria, 32(1), 83-88. soldati m., corsini a., pasuto a. (2004) landslides and climate change in the italian dolomites since the late glacial. catena, 55, 141-161. soldati m., borgatti l., cavallin a., de amicis m., frigerio s., giardino m., mortara g., pellegrini g.b., ravazzi c., surian n., tellini c., zanchi a. (2006) geomorphological evolution of slopes and climate changes in northern italy during the late quaternary: spatial and temporal distribution of landslides and landscape sensitivity implications. geografia fisica e dinamica quaternaria, 29, 165183. tintor w., andrič m. (2014) lateglacial studies in the western valleys of the italian julian alps and in the koritnica valley. acta geographica slovenica, 54, 7 -20. torsnes i., rye n., nesje, a. (1993) modern and little ice age equilibrium-line altitudes on outlet valley glaciers from jostedalsbreen, western norway: an evaluation of different approaches to their calculation. arctic and alpine research, 25, 106-116. van husen d. (1997) lgm and late-glacial fluctuations in the eastern alps. quaternary international, 3839, 109-118. van husen d. (2000) geological processes during the quaternary. mitteilungen der österreichischen geologischen gesellschaft, 92, 135-156. vescovi e., ravazzi c., arpenti e., fisinger w., pini r., valsecchi v., wick l., ammann b., tinner w. (2007) interactions between climate and vegetation during the lateglacial period as recorded by lake and mire sediments archives in northern italy and southern switzerland. quaternary science reviews, 26, 1650-1669. von klebelsberg r. (1947) die heutige schneegrenze in den ostalpen. berichte des naturwissenschaftlich-medizinischen vereines, innsbruck, 47, 9-32. von klebelsberg r. (1948) handbuch der gletscherkunde und glaziologie, bd.1. springer, wien, pp. 1028. von klebelsberg r. (1950) südtiroler geomorphologische studien. das mittlere eisacktal (ii. die höheren tallagen und die einfassende berge). museum ferdin, innsbruck, vol. xxx. 67 reappraisal of lateglacial stadials in the eastern alps ms. received: may 18, 2016 final text received: april 18, 2017 geoarchaeological evidences of changes in the coastline progradation rate of the versilia coastal plain between camaiore and viareggio (tuscany, italy): possible relationships with late holocene high-frequency transgressive-regressive cycles monica bini1, giovanni sarti1, simone da prato1, fabio fabiani2, emanuela paribeni3 & carlo baroni1 1dipartimento di scienze della terra, via s. maria 53, università di pisa bini@dst.unipi.it, sarti@dst.unipi.it 2dipartimento di scienze archeologiche, via s. maria 53, università di pisa 3soprintendenza per i beni archeologici della toscana via s. maria pisa abstract: bini m. et al., geoarchaeological evidences of changes in the coastline progradation rate of the versilia coastal plain between camaiore and viareggio (tuscany, italy): possible relationships with late holocene high-frequency transgressive-regressive cycles. (it issn 0394-3356, 2009) the late holocene progradation of the versilia coastal-plain, between camaiore and viareggio (tuscany, italy), was investigated on the basis of geomorphological, stratigraphical, and archaeological data. five geomorphological units, corresponding to the camaiore alluvial fan, beach-dune ridges, interdune marshes, a back dune marsh (giardo and related massaciuccoli lake area), and the presentday beach, were identified. archaeological data provide some chronological constraints on the timing of late holocene coastal progradation. about 3000 yrs ago, the coastline was located about 2,5 km landward in respect to its present-day position, in the proximity of the migliarina beach dune, behind which a marsh area developed. this marsh extended from the giardo to the present-day massaciuccoli lake. the connection between giardo and massaciuccoli area allows us to reconsider the role of acquarella site in becoming an important centre in commercial communication among sea, coast, and inland areas. around the 12th century the coastline was located in proximity of the dune alignments where motrone fort and the castello vecchio di viareggio were built testifying a progradation of about 1,3 km. during the next four centuries the coastline continued its seaward shifting for 500 m more and was located in proximity of the matilde tower. from the 16th to the present time the progradation of the coastline has been proceeded by of about 0,7 km. these data indicate changes in the progradation rate during that the time and in particular an increase since the 16th century. an irregular progradation rate agrees with stratigraphic and facies analysis based on surface and subsurface data (wells and excavations) that allowed us to define a preliminary framework of the last phases of coastline progradation. the identification of four high-frequency small-scale transgressiveregressive cycles (parasequences) within the succession recording the late holocene phase of progradation points to evidence that the progradation rate of the coastline was subject to cyclic fluctuations. riassunto: bini m. et al., evidenze geoarcheologiche di variazioni nel tasso di progradazione della pianura versiliese nel tratto compreso tra camaiore e viareggio (toscana, italia): possibili relazioni con cicli trasgressivo-regressivi ad alta frequenza tardo olocenici. (it issn 0394-3356, 2009). l’integrazione tra dati geomorfologici, stratigrafici e archeologici ha permesso di analizzare alcune delle tappe di progradazione della pianura costiera versiliese nel tratto compreso tra camaiore e viareggio (toscana, italia). nell’area di studio, sono state individuate cinque unità morfologiche: la conoide alluvionale del torrente camaiore, una serie di cordoni dunali, le aree umide interdunali, la più ampia area umida del giardo e la spiaggia attuale. i dati archeologici hanno permesso di porre alcuni vincoli cronologici riguardo i tempi della progradazione della linea di costa. circa 3000 anni fa la linea di costa, si trovava arretrata di circa 2,5 km rispetto alla sua posizione attuale, ed era localizzata in prossimità della duna della migliarina, alle spalle della quale si estendeva un’area palustre (giardo) in comunicazione verso sud con l’attuale lago di massaciuccoli. la comunicazione tra le due aree permette di riconsiderare in una luce nuova il ruolo del sito dell’aquarella nel divenire un importante centro commerciale di comunicazione tra il mare, la costa e le zone interne. attorno al 12th secolo la linea di costa era avanzata di circa 1,3 km e si trovava in prossimità dell’allineamento di dune dove furono costruiti il forte di motrone e il castello vecchio di viareggio. durante i quattro secoli successivi la progradazione continuò per circa 500 m e, nel 16th secolo, la linea di costa era localizzata all’altezza della torre matilde. dal 16ths ecolo ad oggi il processo di progradazione è proseguito per circa 0,7 km. questi dati indicano variazioni nel tempo del tasso di progradazione ed in particolare un incremento a partire dal 16th secolo. un tasso di progradazione irregolare è in accordo con i dati stratigrafici e di analisi di facies di depositi superficiali e sub-superficiali (carotaggi e scavi) che hanno permesso di definire un quadro preliminare delle ultime fasi della progradazione costiera nell’area di studio. in particolare l’identificazione di quattro piccoli cicli trasgressivi-regressivi (parasequenze) ad alta frequenza all’interno della successione che registra le fasi di progradazione tardo oloceniche suggerisce fluttuazioni cicliche nel processo di progradazione della linea di costa. keywords: coastal plain progradation, parasequences, late holocene, versilia. parole chiave: progradazione pianura costiera, parasequenze, tardo olocene, versilia. il quaternario italian journal of quaternary sciences 22(2), 2009 257-266 introdution this work focuses on the late holocene paleogeographic reconstruction of a sector of the versilia coastal plain (fig.1) between camaiore and viareggio (tuscany, italy). over the last 3000 yr, this area has experienced a coastline progradation of about 2,5 km, but the causes of this process are still not completely explained. many studies support the relationships between high-frequency climatic variations (millennial to centennial scale), probably associated with smallscale sea-level fluctuations, and the development of 258 m. bini et al. small transgressive-regressive cycles (e.g., lo w r i e & ha m i t e r, 1995; bo y e r et al ., 2005; am o r o s i et al., 2005; leorri e t al., 2006). three millennial-scale transgressive-regressive cycles have recently been recognized (amorosi et al., 2009) about 20 kilometers south of the study area (subsurface of the arno coastal plain) within the transgressive deposits late pleistocene-holocene in age (13-8 ky cal b.p.). in the neighbouring archaeological site of pisa, which contains roman ships, stratigraphic and sedimentological studies show that the cause of repeated episodes of river harbor destruction were high-frequency centennial-scale climatic and possibly eustatic changes (be n v e n u t i et al . , 2 0 0 6 ) . based on these data and considering the neighbouring arno and versilia coastal plain, the hypothesis that also the study area may have experienced short phases of stillstand, if not transgressions, seems plausible. the aim of this paper, using a multidisciplinary approach that includes the use of geomorphological, sedimentological, and archeological data, is to define the timing of progradation of the versilia coastal plain over the last 3000 yrs and to discuss the possible key factors that may have been controlled this process. 2. geological setting the study area (fig. 1) is within the communities of viareggio and lido di camaiore, (nw tuscany). the modern arno and versilia coastal plain is part of the onshore portion of the wider viareggio basin, an extensional area oriented nw-se, which has been active since the upper tortonian (ma r i a n i & pr a t o, 1988; ar g n a n i et al., 1997; pa s c u c c i, 2005). this basin is filled with about 2500 m of deposits spanning from late miocene to the present. the uppermost portion (late pleistocene-present, corresponding to seismic sequence 6b of pa s c u c c i, 2005) has been investigated for its chronostratigraphic relevance and specifically for defining the versilian stage (bl a n c, 1937, 1942; fe d e r i c i, 1993). the late quaternary depositional evolution has been recently reconstructed based on data from the enea core (figs. 1, 2) dri lled near the massaciuccoli lake about 10 km se of the study area (an t o n i o l i et al. , 2000; de v o t i et al., 2003; ni s i et al. , 2003). the base of the holocene transgression (10.568 -10.236 cal b.p., see an t o n i o l i et al. , 2000) is identified (fig. 2) at a depth of about 34 m from the surface, at the transition from alluvial to paralic deposits bearing brackish fauna. these deposits grade upwards into marine sands. their top (9 m below ground level) is dated to 5896-5830 cal b.p. (an t o n i o l i et al. , 2 0 0 0 ) and is overlaid by alternating peat layers, sands, and clays bearing brackish fauna. an age of 2627 2129 cal. b.p (2,5 m below ground level) has been attributed to these deposits (an t o n i o l i et al. , 2000). from the apuane foothi l ls to the coast , the outcropping deposits record a variety of depositional environments, such as some small coalescent alluvial fans, marsh areas connected to massaciuccoli lake, coastal dune systems with related interdune areas, and the presentday beaches. methods geomorphologic surveys, field aerial photographs, and stratigraphic analysis were used to develop a detailed geomorphologic and geologic map at 1:10.000. sedimentological and facies analysis, based on surface and subsurface data also allowed us to define a preliminary framework of relationships among the depositional units recognized. subsurface data derive from a working-face about 6 m deep and 100 m wide (a in fig. 3), where a continuously cored borehole (s5) was also drilled (location in fig. 3), and from another excavation (3 m depth and 15 m wide; b in fig. 3) located about 4,5 km northward. moreover, micropaleontologic data lead to a better definition of the depositional environments. twentysix samples were collected from section a and were washed and sieved with an 88 µ mesh. thirty-two ostracods and twelve foraminifera species were recovered. most of these presently live in the mediterranean area (bonaduce et al., 1976; sgarella & moncharmontzei, 1993). the plotting of archeological data, recorded since the 16t h century, on the map provided further chronological constraints for reconstructing the palaeogeographical evolution of the study area with particular attention to coastline variations. fig. 1 map of the study area and location of stratigraphic study sections (a, b). mappa schematica dell’area di studio con ubicazione delle sezioni studiate (a, b). geomorphologic data the geomorphologic data, derived from field surveys and multitemporal aerial photographs analyses, allowed the identification of five geomorphological units: 1) the camaiore alluvial fan, 2) dune ridge, 3) small marshes located in the interdune areas, 4) a major marsh area named giardo, and 5) the present day beach (fig. 3 ). 259geoarcheological evidences of changes in the coastline ... the camaiore alluvial fan is about 4 km long and 2,5 km wide, and records cyclic depositional and quiescent phases during the late pleistocene-holocene (federici, 1993). the alluvial fan reaches an elevation of 20 m in the foothills (apex) and decreases with a uniform and low gradient (<2% average dip) to an elevation of 2 m asl towards its distal area (fig. 3). lateral channel migration from west to east is suggested by the identification of several palaeo-channel traces on fig. 2 stratigraphy of enea core (redraw after antonioli et al., 2000). a and b: study sections. for their location see fig 1 and fig 3. stratigrafia del sondaggio enea (ridisegnato da antonioli et al., 2000). a e b: sezioni studiate. per la loro localizzazione si vedano le figg. 1 e 3. 260 the fan surface. subsurface data available from a working face (bini et al., 2007) carried out on the distal fan area (c in fig. 3), reveal that fine-gravels are intercalated with organic-rich silt and clay related to the giardo marsh. this indicates phases of progradation of the camaiore alluvial fan into the giardo marsh. the giardo marsh, which is late-holocene in age (federici, 1993), is located between the camaiore alluvial fan and the oldest beach ridge dune alignment and was connected in the past with the massaciuccoli lake area. this connection is strongly supported, according to de v o t i e t a l. , 2003, by geomorphological surveys (fig. 3). today it represents a lowland about 1,8 km long, 1,5 km wide, and is relatively depressed (1 m asl) with respect to the surrounding morphological units. it is occupied by a small permanent lake and several ephemeral marshes. its fill is characterized by sands, silts, and peat. the dune ridges, whose alignment records the position of the shoreline during the late holocene, are located between the giardo marsh and the present-day coastline (fig. 3). these dunes belong to an articulate beach-ridge system (ma z z a n t i & pa s q u i n u c c i, 1983) that characterizes the coastal plain from the arno river (south) to the magra river (north). unfortunately, the modern human settlements that developed along the coast makes it difficult to identify the original morphology of each beach ridges. they are normally closely spaced, with interdune marshes employed as fish tanks (benzio, 1986) from the early middle ages up to the 18th century and represented an important economic resource for the local community. the landward dune (migliarina beach ridge dune in fig. 3) is located in front of the massaciuccoli lake area. it is the most elevated (1,5 m asl) and the best preserved. archaeological findings (see § 5) date the migliarina dune to an age not younger than the 7t h century b.c. (bi n i et al., 2007). this implies that the age of development of the related back-ridge marsh area (giardo marsh) can not be older. moving toward the coast, historical buildings permit us to date two other beach-ridge alignments. the motrone fort and the castello vecchio di viareggio (fig. 3, n.7) were built in the 12t h century, while the matilde tower (fig. 3, n.15) was built in the 16th century. these buildings mark the variation of the coast line during this time because the towers were coastal defences and are described as having been built on the beach (mazzanti & pasquinucci, 1983) (see § 5). the younger morphologic unit corresponding to fig. 3 geomorphological map with the location of the most important archaeological sites 1) capocavallo; 2) villa mansi; 3) acquarella; 4) capezzano pianore; 5) trebbiano; 6) bucine; 7) motrone fort; 8) tongo; 9) tombolo; 10) ortacci; 11) migliarina; 12) san rocchino; 13) castello vecchio di viareggio; 14) matilde tower. a and b: study sections. c: location of stratigraphic section reported in bini et al. 2007. carta geomorfologia con l’ubicazione dei principali siti archeologici 1) capocavallo; 2) villa mansi; 3) acquarella; 4) capezzano pianore; 5) trebbiano; 6) bucine; 7) forte di motrone; 8) tongo; 9) tombolo; 10) ortacci; 11) migliarina; 12) san rocchino; 13) castello vecchio di viareggio; 14) torre matilde. a e b: sezioni studiate. c: ubicazione della sezione stratigrafica riportata in bini et al. 2007. m. bini et al. 261 the present-day beach is actually in accretion (1 m per year; ci p r i a n i et al., 2004) due to the influence of viareggio harbour and its piers on the longshore sediment flux. stratigraphic and sedimentological data the stratigraphic and sedimentological data have been collected from a working-face about 6 m deep and 100 m wide (a in fig. 3), where a continuously cored borehole (s5) was also drilled, and from another excavation (3 m depth and 15 m wide; b in fig. 3) located about 4,5 km northward. unfortunately, the s5 core was destroyed and the available data are a log description and a photographic documentation. the stratigraphy of the enea core (antonioli et al., 2000), drilled about 10 km south-east of the study area, was utilized as a reference for interpreting the data collected in this study (fig. 2; see fig. 1 for the location). facies analysis of section a shows an overall regressive trend passing upward from shallow-marine to coastal-dune deposits that also outcrop at the surface. four small transgressive-regressive cycles (a1a4; parasequences s e n s u va n wa g o n e r et al., 1990; kamola & van wagoner, 1995) have been defined within this general trend (fig. 2). the lowest cycle (a1) is characterized by shallow marine sandy-silt bearing a relatively diversified microfauna constitued by ostracods (cytheridea neapolitana, pontocythere turbida, leptocythere ramosa, cytheretta subradiosa, cytheretta adriatica, neocytherideis fasciat a) and foraminifera (haynesina depressula, ammonia beccarii, quinqueloculina seminulum, and rare specimens of florilus boueanum, and elphidium crispum). the presence of vegetal debris associated with some reworked brackish to freshwater ostracods (e.g., cyprideis torosa and candona spp.) indicates the proximity to a paralic depositional environment such as an inner lagoon or a small bay. these deposits pass upward to medium and coarse sands (upper shoreface) with scarce and poorly diversi fied microfauna. accumulation at the top of this sequence of centimetric lenticular layers of coarse vegetal debris, showing evidence of traction processes, has been related to a foreshore environment such as a storm berm. low to highangle cross-beds fine laminated sands interpreted as backshore to dune deposits form the upper portion of parasequence a1 (fig. 4). sands showing chevron stratification related to wave processes indicate the return to subaqueous conditions (a2 parasequence). upward the sands display a progressive increase in microfauna diversification and abundance (pontocythere turbida, palmoconcha turbida, haynesina depressula, ammonia beccarii a n d elphidium crispum) up to 6 m depth (fig. 2) even lower than observed in parasequence a1. we interpret these sediments as having been deposited in a very shallowmarine environment close to the coastline. the nearness of coast is also supported by the occasional presence of vegetal debris. in the uppermost portion of parasequence a2, medium to coarse foreshore-stormberm sands displaying coarse vegetal-rich centimetric levels overlaid by well-sorted backshore fine sands represent the regressive phase (fig. 5). parasequences a3 and a4 show features very similar to those observed in a2, recording the transition from a very shallow-marine to a foreshore-backshore depositional environment (fig. 2). we think plausible the correlation between section a and the upper portion of the enea core, recording the progradational phases wich occurred during the late holocene (fig. 2). even though the lack of detailed facies from this core stratigraphy do not allow the accurate placing of the transition from the retrogradational to progradational depositional phase (maximum flooding surface), we can assume that it occurs between 10 15 m depth, in the uppermost part of the marine siliceous sands (see antonioli et al., 2000) considering the occurrence, few meters above, of a peat layer. indeed it is undoubtedly, according to nisi et al., 2003, that the occurrence of this layer at a depth of 8,50 m indicates the transition from a marine to a paralic depositional environment. similarly, in s5 core the first organic-rich level above the marine sands occurs about 9 m depth (fig. 2) and coincides with the base of section a. for this reason we can correlate section a with the upper part of enea core. fig. 4 uppermost portion of a1 parasequence. from the bottom: centimetric lenticular levels of vegetal debris, displaying evidences of traction processes related to a foreshore storm berm depositional environment. these deposits passes upwards low to high-angle laminated fine sands, interpreted as backshore to dune deposits (see fig. 2 to place the photo within the stratigraphic log) porzione superiore della parasequenza a1. dal basso: livelli lenticolari centimetrici di resti vegetali, che mostrano evidenze di processi trattivi legati ad un ambiente deposizionale di battigia-berma di tempesta. questi depositi passano verso l’alto a sabbie fini con laminazione da basso a alto angolo, interpretate come depostesi in ambienti da spiaggia emersa a duna eolica (si veda la fig. 2 per la posizione della foto nel log stratigrafico). geoarcheological evidences of changes in the coastline ... 262 section b cuts, about 5 km northwards from a, the same sandy coastal dune deposits (fig. 3). from the bottom to the top (fig. 2) the stratigraphic succession consists of i) backshore to upper shoreface deposits, ii) a centimetric layer of peat related to a paralic environment,.and iii) about 2,5 m of pedogenized dune deposits. on the basis of stratigraphic and morphological data, we correlate section b with the uppermost portion of section a, and particularly with the regressive part of parasequence a4 (fig. 2). archaeological data our knowledge of human settlements in the coastal plain of versil ia between camaiore and viareggio is related to some archaeological findings, mostly casual, which have been recorded since the 16th century. the site of acquarella (fig. 3, n. 3), whose archaeological and naturalistic aspects are still under investigation, shows a remarkable continuity of human settlement since the roman archaic period to the early middle-ages (paribeni et al., 2006; bini & fabiani, 2008). the first settlement documented in the acquarella site goes back to the end of the 6th century b.c. at that time, it is possible that the giardo marsh (see § 2) was already connected with the massaciuccoli lake area. acquarella, in addition to contributing to the agricultural exploitation of the plain and the nearby hills, played a strategic role in commerce. it was located at the junction of the coastal routes (terrestrial, maritime, and lagoon) and those which linked the coast to the plain of lucca and to the serchio valley, through the valley of camaiore. the burial site which was found at villa mansi, close to acquarella (fig. 3, n. 2), perhaps part of a necropolis, suggests the existence of a village and demonstrates the vitality of the area since the end of the 7t h century b.c. (ci a m p o ltrini, 1990). (e.p.) on the coast, the intensity of ship traffic is demonstrated by the settlement of san rocchino (fig. 3, n.12). this site was inhabited from the end of the 8t h century b.c. up to the 3r d century b.c., and was situated on the border of the ancient marsh-lake area. since its founding, this settlement was devoted to the commercial economy, and was visited constantly by sailors coming from south-etruria, greece, and the area east of greece. in the earliest period, this site was probably so vital because of the metallic resources mined inland from versilia. this is demonstrated, for example, by a cache containing bronze materials of the protohistoric period located on the hi ll of camaiore (bonamici & fabiani, 2006). the migliarina site (fig. 3, n.11), a productive and specialized settlement of the end of the 7th century b.c., was located on a coastal dune deposit marking the coast line during this time. behind the dune, a marsh area connected to the sea developed (see § 2). one of its purposes was, perhaps, salt production (ci a m p o l t r i n i, 2005). acquarella again gives us the most articulate documentation about the roman period. here, it is possible to follow the phases of construction of a rustic building which was reorganized many times, from the republic age up to late-antiquity (fig. 6). the proximity to the fig. 5 transition from foreshore-storm berm to backshore depositional environments in the uppermost of a2 parasequence. note the abrupt granulometric change from medium to coarse sands displaying organic-rich centimetric levels to a well-sorted fine sands (see fig. 2 to place the photo within the stratigraphic log). passaggio, nella parte alta della parasequenza a2, da ambienti deposizionali di battigia-berma di tempesta a spiaggia emersa. si noti il brusco cambio granulometrico da sabbie medie-grossolane contenenti livelli centimetrici ricchi in materiale organico a sabbie fini ben classate (si veda la fig. 2 per la posizione della foto nel log stratigrafico). fig. 6 view of acquarella archaeological site. veduta del sito archeologico di acquarella. m. bini et al. hill-foot route between pisa and luni, part of the road link on the way to lucca, must have played a role in the prosperity and in the prolonged vitality of the site, which was converted during the early middle-ages into a settlement of huts, possibly fortified. weak traces of centuriation, roman predials, like capezzano and trebbiano, together with occasional discoveries (fig. 3, n.1, 4, 5, 6) on the coastal dune (fig. 3 n. 8, 9, 10; bini et al., 2007), confirm the settlement of the camaiore alluvial fan area . moreover, an important road, which could be identified with the aurelia/aemilia scauri, ran along the coast (fa b i a n i, 2006).the fortress of motrone (fig. 3, n.7), erected in maris littore (giannotti, 2006), and the fortress of viareggio (fig. 3, n.13), which was built during the 12th century a.d., are important reference points for dating the coastal dune deposits in the middle-ages (bini et al., 2007). in viareggio, the building of the new tower matilde (fig. 3, n.14) during the 16t h century, in a more advanced position than the old fortress, demonstrates the gradual advance of the coastline. (f.f) discussion some of the late phases of progradation that affected the coastline of the study area during the last 3000 yrs were detected by the integration of geomorphological, stratigraphical, and archaeological data. the chronostratigraphic framework, derived from archeological data, indicate that the coastline was located i) near the migliarina dune around the 7th century b.c., ii) in the proximity of the motrone fort and the castello vecchio di viareggio (fig. 3, n.7, 13) in 12t h century and iii) near the matilde tower (fig. 3, n.14) during the 16t h century. these buildings were, in fact, built on the beach (ma z z a n t i & pa s q u i n u c c i 1983) as coastal defences. other ages derived from archeological findings give us other information about the landscape of the study area. the acquarella site, located on the camaiore fan, was active since the end of the 6th century b.c. and its role in becoming an important centre in the commercial communication between sea, coast, and inland areas was probably related to its closeness to the back dune marsh area (giardo marsh). indeed, this area, developed around the 7t h century b.c., was in connection with the massaciuccoli lake area southward and thus to the sea also according to the features of the san rocchino site (fig. 3, n.11) settled from the end of the 8th century b.c. up to the 3r d century b.c and devoted to shipping traffic. this demonstrates that if the archeological data play a significant role in defining the timing of the history of the progradation phases in the study area, the geomorphological and stratigraphic study have important implications in the context of the environments where the archeological sites developed. on this basis the landscape, around 3000 yrs ago, was characterized by i) a coastline located about 2,5 km landward in respect to its present-day position near the migliarina beach ridge, ii) a wide protected brackish marsh area (giardo marsh) that was connected southward to the massaciuccoli lake system behind the coast, and iii) an alluvial fan system (camaiore fan) periodically connected with the giardo marsh. afterward, repetitive phases of progradation took place, causing the development of a strandplain characterized by a wide back dune marsh area (giardo marsh). archeological data permit us to state that i) around the 12th centuries the coastline had experienced a progradation of about 1,3 km and was located in proximity of the dune alignments where motrone fort and the castello vecchio di viareggio (fig. 3 n°7, 13) were built and that ii) four centuries later the coastline had again moved seaward of about 500 m and was located near matilde tower (fig. 3, n.14). from the 16th century to the present time the progradation of the coastline has proceeded by about 0,7 km. on this basis, although the available data are sparse, a progradation rate was calculated (fig. 7). the data show a relatively low progradation rate from the 7th century b.c until the 16t h century (about 0,7m/yr), followed by a pronounced increase (1,75 m/yr), still active. actually, this area is currently subject to expansion (1 m/yr) because of the influence of the piers of the viareggio harbor on the longshore sediment transfer (ci p r i a n i et al., 2004). the rapid increase after the 16t h century appears to be significant and agrees with an analogous study carried out on the tuscan coast (sarti & ciulli, 2008; pranzini, 2001) and has been related to an increase of sediment supply due to deforestation (pranzini, 2001). nevertheless, it is worth noting that the average 263 fig. 7 diagram showing the variation of the progradation rate for the verislia coastal plain over time. the rate is calculated starting from the coastline position during the 7th century a.c. (corresponding to the most landward outcropping duneduna della migliarina fig. 3, n. 11) and considering the coastline position in the 12th century a.c. (fig. 3, n.7 e 13), in the 16th century (fig. 3, n.14) till the present-day coastline position (the latter deduced on the basis of cipriani et al. 2004 data). grafico della variazione del tasso di progradazione nel tempo. il tasso viene calcolato considerando come riferimento la posizione della linea di costa nel vii secolo a.c. (corrispondente al cordone dunare più interno affiorante duna della migliarina fig. 3, n.11) e attraverso la posizione della linea di costa nel xii sec. d.c.(fig. 3, n. 7 e 13), nel xvi sec. d.c. (fig. 3, n.14) fino alla posizione della linea di costa attuale (ricavata sulla base dei dati di cipriani et al.,2004). geoarcheological evidences of changes in the coastline ... rate of progradation calculated between the 7th century b.c. and the 16th century a.d., does not consider all the possible (and highly probable) fluctuations that could have occurred during this time (e.g., increase or reductions of the rate of progradation, or even phases of retrogradation of the coastline). the hypothesis that the progradation took place irregularly is also strongly supported by the subsurface stratigraphic data, evidencing four small high-frequency transgressive-regressive cycles within the succession recording the late holocene phase of progradation. high-frequency transgressive-regressive cycles have been documented from late quaternary to holocene successions of mississippi, ebro, rhône and po deltas (lo w r i e & hamiter, 1995; somoza et al., 1998; boyer et al., 2005; amorosi et al., 2005) and, recently, of arno coastal plain about 20 km southward to the study area (amorosi et al., 2009). a combination of small-scale sea-level fluctuations and rapid climatic variations (millennial to centennial scale) has been guessed as the possible major controlling factor of stratigraphic architecture in these areas even if in the arno coastal plain (am o r o s i et al. 2009) pollen characterization evidences the development of parasequences as chiefly the function of highfrequency (millennial scale) climatic variations. a climatic control (centennial-scale) during the late holocene is also suggests by benvenuti et al. 2006, on the basis of detailed sedimentological and stratigraphical study, from an archaeological site near pisa urban area, where a riverine harbour, erected in etruscan age, was discovered. in this study the close relationships between recurring events of harbour destruction and high-magnitude flood episodes due to high-frequency climatic changes is documented. even if no data are at the present available from the study area the neighbouring with the arno coastalplain makes it very probable that high-frequency climatic changes have played an important role in the dynamics of coastline position. further multidisciplinary studies in the area could confirm this hypothesis. concluding remarks the integration of geomorphological, stratigraphical, and archaeological data allows for the reconstruction of the late phases of progradation that affected the study area during the last 3000 yr. the following key points can be highlighted: 1) about 3000 yr ago the coastline was located about 2,5 km landward in respect to its present position in proximity of migliarina dune, and behind the dune, a marsh (giardo marsh) connected to the massaciuccoli lake area developed; 2) the connection between the giardo and massaciuccoli areas allows a better understanding of the characteristics of the archaeological site of acquarella and this played an important role in it becoming an important centre in commercial communication between the sea, coast, and inland; 3) the timing of the coastline position is also constrained to the 12t h and 16t h centuries; during the interval between 3000 yr and the 12th the progradation of the coastline was about of 1,3 km and of about 500 m between the 12th and 16th centuries; 4) the estimate rate of progradation shows a significant increase since the 16t h century to the present day testified by a progradation of the coastline of about 0,7 km; 5) evidence of four small high-frequency transgressive-regressive cycles within the succession recording the late holocene phase of progradation in the subsurface of the study area supports the hypothesis that the progradation took place irregularly. acknowledgements we would like to thank the fondazione cassa di risparmio di lucca a n d museo archeologico di c a m a i o r e for their support. we are grateful to m. benvenuti and to anonymous contributors for their accurate review. thanks are also due to s. giacomelli for her contribution in the discussion of the manuscript. this work has been funded by provincia di pisa of a grant to dr. g. sarti. references amorosi a., centineo m.c., colalongo m.l. & fiorini f. (2005) millennial-scale depositional cycles from the holocene of the po plain, italy. m a r i n e geology, 222–223, pp. 7–18. amorosi a., ricci lucchi m., rossi v. & sarti g. (2009) climatic signature of millenial-scale parasequences from lateglacial-holocene transgressive deposits of arno valley fill (tuscany, italy). in press, palaegeography, palaeoclimatology, palaeoecology. antonioli f., girotti o., impronta s., nisi m.f., pugliesi c. & verrubbi v. (2000) nuovi dati sulla trasgressione marina olocenica e sulla subsidenza della pianura versiliese attraverso in sondaggio di 90 m e t r i. in atti del convegno “le pianure. conoscenza e salvaguardia il contributo delle scienze della terra”. 8-10 novembre 1999, ravenna. regione emilia romagna, bologna, italy, pp. 214–218. argnani a., bernini m., di dio g.m., papani g. & rogledi s. (1997) stratigraphic record of crustal scale tectonics in the quaternary of the northern apennines (italy). quaternario 10, pp. 595–602. be n z i o c. (1986) viareggio. storia di un territorio. le marine lucchesi tra il xv e il xlx secolo. pacini ed., pisa, 240 pp. be n v e n u t i m., ma r i o t t i– li p p i m., pa l l e c c h i p. & sa g r i, m. (2006) late-holocene catastrophic floods in the terminal arno river (pisa, central italy) from the story of a roman riverine harbour. t h e holocene 16, pp. 863–76. bini m., fabiani f. & fornaciari a. (2007) ambiente e popolamento nella pianura costiera di camaiore (lu). primi risultati e prospettive di una ricerca g e o a r c h e o l o g i c a . science and technology for cultural heritage, 16 (1-2), pp. 31-43. bini m. & fabiani f. (2008) indagini geoarcheologiche nel sito pluristratificato dell’acquarella (camaiorel u ) . notiziario della soprintendenza per i beni archeologici per la toscana, in press. 264 m. bini et al. blanc a.c. (1937) la stratigraphie de la plaine côtière de la bassa versilia (italie) et la transgression flandrienne en mediterrannée. rev. géogr. phys. géol. dyn., 9 (2), pp. 129-162. blanc a.c. (1942) variazioni climatiche ed oscillazioni della linea di riva nel mediterraneo centrale durante l ’era glaciale. sond. geologie meere binnenengenwasser, 5, pp. 50-90. bo n a d u c e g., ci a m p o g. & ma s o l i m. (1976) d i s t r ibution of ostracoda in the adriatic sea. p u b b l . staz. zool., napoli, 40 (1), 154 pp. bo n a m i c i m. & fa b i a n i f. (2006) museo archeologico versiliese bruno antonucci, pietrasanta. i n notiziar io della soprintendenza per i beni archeologici per la toscana, 2, pp. 547-548. boyer j., duvail c., le strat p., gensous b. & tesson m. (2005) high resolution stratigraphy and evolution of the rhône delta plain during postglacial time, from subsurface drilling data bank. m a r i n e geology 222-223, pp. 267–98. ci a m p o l t r i n i g. (1990) villa mansi (camaiore). in etruscorum ante quam ligurum. la versilia tra vii e iii secolo a.c. paribeni (a cura di), p o n t e d e r a , bandecchi e vivaldi eds. pp. 119-121. ci a m p o l t r i n i g. (2005) gli etruschi della garfagnana. ricerche nell ’insediamento della murel la a castiglione di garfagnana. polistampa eds. 112 pp. ci p r i a n i l.e., fe r r i s., ia n n o t t a p., ma n n o r i s. & pr a n z i n i e. (2004) evoluzione recente delle spiagge toscane. in il piano regionale di gestione integrata della costa ai fini del riassetto idrogeolog i c o. in erosione costiera. edifir, firenze, pp.7592. devoti s., nisi m. f. & silenzi s. (2003) caratteri geologici ed evoluzione paleogeografica della pianura versiliese. studi costieri, 6, pp. 73-89. fa b i a n i f. (2006) “… stratam antiquam que est per palude set boscos …”. viabilità romana tra pisa e luni. ed. plus pisa, 191 pp. federici p.r. (1993) the versilian transgression of the versilia area (tuscany, italy) in the light of drillings and radiometric data. mem. soc. geol. it., 49, pp. 217-225. giannotti s. (2006) pietrasanta (lu). controllo archeologico a motrone. in notiziario del la soprintendenza per i beni archeologici per la toscana, 2, pp. 22-25. kamola d.l. & van wagoner j.c. (1995) stratigraphy and facies architecture of parasequences with examples from the spring canyon member, blackhawk formation, utah. in van wagoner, j.c., bertram, g.t., editors, sequence stratigraphy of foreland basin deposits. american association of petroleum geologists memories 64, pp. 27–54. leorri e., martin r. & mclaughlin p. (2006) holocene environmental and parasequence development of the st. jones estuary, delaware (usa): foraminiferal proxies of natural climatic and anthropogenic change. p a l a e o g e o g r a p h y , palaeoclimatology, palaeoecology 2 4 1, pp. 590–607. lo w r i e a. & ha m i t e r r. (1995) fifth and sixth order eustatic events during holocene (fourth order) highstand influencing mississippi delta-lobe s w i t c h i n g. journal of coastal research, special issue, holocene cycles: climate, sea levels, and sedimentation, 17, pp. 225–229. ma r i a n i m. & pr a t o r. (1988) i bacini neogenici costieri del margine tirrenico: approccio sismicostratigrafico. mem. soc. geol. it. 41, pp. 519-531. mazzanti r. & pasquinucci m. (1983) l’evoluzione del litorale lunense-pisano fino alla metà del xix secolo. boll. soc. geogr. it., 12, pp. 605-628. nisi m., devoti s., gabellino m., silenzi s. pugliesi c. & verrubbi v. (2003) acquisizione di dati territoriali per la valutazione del rischio da risalita del livello del mare in versilia. studi costieri, 6, pp. 91-131. paribeni e., fabiani f., bini m., boschian g. & cuniglio l. (2006) camaiore (lu). il complesso rustico dell’acquarella: dall’indagine conoscitiva alla valor i z z a z i o n e. notiziario della soprintendenza per i beni archeologici per la toscana, 1, pp. 42-49. pascucci v. (2005). neogene evolution of the viareggio basin, northern tuscany (italy). geoacta, 4, pp. 123-138. pr a n z i n i e. (2001) updrift river mouth migration on cuspate deltas: two examples from the coast of tuscany italy. gemorphology, 48, pp. 125-132. sa r t i g. & ci u l l i l. (2008) carta di sintesi alla scala 1/50000 e revisione bibliografica dei dati esistenti per la definizione dell’evoluzione stratigrafico deposizionale dei sistemi dunali costieri della provincia di pisa. in: “attivita’ di studio e ricerca a supporto degli interventi sperimentali di recupero, protezione e monitoraggio del sistema dunale”. conv. provincia di pisa-università degli studi di pisa. resp. g. sarti, 60 pp. so m o z a l., ba r n o l a s a., ar a s a a., ma e s t r o a., re e s, j.g. & he r n a n d e zmo l i n a f . j. (1998) architectural stacking patterns of the ebro delta controlled by holocene high-frequency eustatic fluctuations, delta-lobe switching and subsidence processes. sedimentary geology 117, pp. 11– 32. sg a r e l l a f. & mo n c h a r m o n t ze i m. (1993) b e n t h i c foraminifera of the gulf of naples (italy): systematics and autecology. boll. soc. paleont. ital. 32, pp. 145– 264. va n wa g o n e r j.c., mi t c h u m r.m., ca m p i o n k.m. & ra h m a n i a n v . d. (1990) siliclastic sequence stratigraphy in well logs, cores and outcrops: concepts for high resolution correlations of time and f a c i e s . american association of american petroleum geologists. methods in exploration, 7, barbara h. lidtz, tulsa, 55 pp. 265 ms. ricevuto il 9 giugno 2008 testo definitivo ricevuto il 16 febbraio 2009 ms. received: june 9, 2008 final text received: february 16, 2009 geoarcheological evidences of changes in the coastline ... amq sr07 martinet al 191-207.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 33 (2), 2020, 191-207 landslides of the western dolomites: case studies from the adige and sarca valleys (ne italy). � silvana martin 1, susan ivy-ochs 2,3, alfio viganò 4, paolo campedel 4, manuel rigo 1,5, christof vockenhuber 3, fabio gabrieli 6, volkmar mair 7, sandro rossato 5 � 1 department of geosciences, university of padova, padova, italy. 2 department of earth sciences, eth zürich, zürich, switzerland. 3 laboratory of ion beam physics, eth hönggerberg, zürich, switzerland. 4 servizio geologico, provincia autonoma di trento, trento, italy. 5 institute of geosciences and earth resources, national research council of italy, padova, italy. 6 department of civil, environmental and architectural engineering, university of padova, padova, italy. 7 ufficio geologia e prove materiali, provincia autonoma di bolzano, cardano (bz), italy. corresponding author: s. rossato <sandro.rossato@igg.cnr.it> abstract: the lavini di marco, marocche di dro and molveno rock avalanches in trentino, and the termeno landslide in south tyrol are here presented as case studies for the western dolomites (adige and sarca valleys, ne italy). their structural predisposition, run-out and timing are discussed, also in consideration of other evidence for the alpine region. the detailed geomorphological mapping of deposits and their release area, combined with regional and local structural analysis, isotopic dating, and numerical modelling, have led to updated interpretations of their mechanisms, timing, and triggering/driving forces. in particular, the major role of structural controls is investigated. intense rock damage and rock fatigue, which are related to tectonic activity along the southern giudicarie and schio-vicenza fault systems, together with high topographic relief energy and local dip slope, all combine to promote detachment of huge rock volumes. besides structural predisposition, other factors like glacial erosion/unloading and climate can exert a primary control. three large rock avalanches occurred between 5-3 ka ago: lavini di marco (200 mm3, 3.0±0.4 ka), marocca principale (1000 mm3, 5.3 ±0.9 ka) belonging to the marocche di dro complex, and molveno (600 mm3, 4.8±0.5 ka). this period has been recognized as one of enhanced slope failure activity in the alps, perhaps related to the climatic transition to cooler and wetter conditions at the beginning of the late holocene. this is particularly valid for the close contemporaneity of the marocca principale and molveno rock avalanches. conversely, younger ages at the kas rock avalanche (marocche di dro complex; 300 mm3, 1.1±0.2 ka) likely imply a close relation with seismic forcing. keywords: landslides, rock avalanches, geomorphological mapping, tectonics, cosmogenic nuclide dating. � 1. introduction the large landslides of the western dolomites are mostly distributed along a narrow area stretching from the northern edge of lake garda to the brenta dolomites, between the sarca and adige valleys (fig. 1). these two valleys are adjacent to each other, running north-south across the southern alps. pleistocene glaciations shaped their landscape entrenching deep glacial troughs and promoting rock instability on their steep flanks. here, many slope failures are developed within the mesozoic sedimentary successions, especially jurassic limestones. the alps and the trentino region are characterized by numerous post-glacial gravitational events (e.g., taramelli, 1881; penck & bru �ckner, 1909; fuganti, 1969; perna, 1974; soldati et al., 2006), which have been interpreted as due to different causes, as climate and seismicity. in fact, strong tectonic events could have triggered landslides during the middle holocene (ambrosi & crosta, 2006; prager et al., 2008). the large landslide deposits of the southern alps mostly made of big boulders were called "marocche". the name “marocca” derives from “mar”, which means stone. perna & sauro (1978) pointed out that this term was used to refer to a landslide that fell onto a glacier, which also transported and deposited the landslide debris. these deposits are often impressive, as the marocche di dro in the sarca valley, and are interpreted as rock avalanche deposits (e.g., ivy-ochs et al., 2017b). according to various authors, a rock avalanche is defined as a large (volume >1 mm3) and very rapid (>40 m/ s) rock mass where debris shows turbulent flow and is sometimes channelized (heim, 1932; hungr et al., 2014; https://doi.org/10.26382/amq.2020.15 192 martin s. et al. aaron & hungr, 2016). here we present four landslide cases in the western dolomites (trentino & south tyrol). lavini di marco and termeno are in the adige valley, while marocche di dro and molveno are located between lake garda and the brenta dolomites. the aim is to reexamine and discuss some data from literature, regarding the rock avalanches of this region, and to present original data on the termeno rockfall study. the landslides discussed in this paper have been also presented in the framework of the sites visited in trentino/south tyrol during the summer school on “historic and prehistoric landslides in the ne italian alps implications for new hazard maps in mountainous areas”, hosted by the university of padua in 2019. the other sites of the veneto region visited during the summer school are presented in a companion paper of this volume (rossato et al., 2020b). 2. landslides of the western dolomites the map of figure 1 shows the distribution of the largest landslide deposits of the western dolomites. the adige valley includes, among others, the lavini di marco (200 mm3; martin et al., 2014), castelpietra (6 mm3; ivyochs et al., 2017a) and termeno (related to several rockfall events) landslide deposits. the adjacent sarca valley and the brenta dolomites include the marocche di dro (>1300 mm3; ivy-ochs et al., 2017b), molveno (600 mm3; von wartburg et al., 2020) and tovel (related to several landslide events with total volume of 300 mm3; oetheimer, 1989) rock avalanche deposits. the famous lavini di marco rock avalanche deposit is located near rovereto, in the middle reach of the adige valley. it was mentioned by dante alighieri in the divina commedia (alighieri, 1314) and was also studied fig. 1 simplified geological map of the sarca and adige valleys (data from the geological survey of trento, carg project database). circle size is proportional to landslide volume (modified from ivy ochs et al., 2017b; elsevier used with permission). the tovel deposits, with an estimated total volume of 300 mm3 (oetheimer, 1989) and shown as a single circle, are due to multiple events. the names of the landslides studied in this work are in red. 193 by many naturalists in the xix century (noriller, 1871; penck, 1886). the termeno landslide is an historical event, located a few kilometers south of bolzano, on the right side of the adige river. it is characterized by isolated gigantic boulders (up to hundreds of cubic meters in volume) detached from the rock walls overhanging the gewürztraminer vineyards. between lake garda and the brenta dolomites, the marocche di dro and molveno rock avalanche deposits are located within the southern giudicarie tectonic realm and have been studied for more than one century (lepsius, 1878; damian, 1890; trener, 1924; abele, 1974; perna, 1974; 1975). these rock failures are located close to the seismically active faults of the nne-trending southern giudicarie and the nw-trending schio-vicenza fault systems, or at the junction of them (castellarin et al., 2005; viganò et al., 2015; 2018). the asymmetric valley configuration is generally characterized by west-dipping bedding planes on eastern valley slopes and tectonic scarps on the western ones. these are due to the regional setting of the giudicarie fault system, which is also responsible of the nne-trending synclines hosting lake garda, the sarca valley and the molveno lake. the lavini di marco, marocche di dro and molveno rock avalanches, as others in the alpine region, were previously ascribed to stress release following downwasting of glaciers at the end of the last glacial maximum, and were thought to have occurred between 18,000 and 12,000 years ago. however, these rock avalanches were much more recent, as shown by isotopic dating, historical records and updated geomorphological observations (martin et al., 2014; carton, 2017; ivy-ochs et al., 2017b; rossato et al., 2020a; von wartburg et al., 2020). 3. rock avalanches and rockfalls of the adige valley 3.1 lavini di marco the lavini di marco rock avalanche deposits consist of the main lavini di marco (ldm in fig. 2) and the minor costa stenda deposits (cs in fig. 2), separated by the costa stenda ridge. other deposits are located on the same flank of the mt. zugna torta (cc, dg, va in fig. 2). these two principal deposits cover a total area of 4.2 km2, with a length of about 4.8 km and a width of about 1.8 km, yielding an estimated volume of 200 mm3 (martin et al., 2014). deposits are located between the adige plain (at 170 m a.s.l.) and the head scarp (at 1260 m a.s.l.; fig. 3). based on an estimated run-out distance of ~4.8 km, abele (1974) calculated a fahrböschung angle of 12°. the rock avalanche involved jurassic carbonate rocks of the calcari grigi group, including the monte zugna, loppio and rotzo formations (see stratigraphic column in fig. 4). detachment occurred on dipslope bedding planes, cut across by nw-trending faults belonging to the schio-vicenza system which (fig. 4). combination of field survey, remote imagery analy landslides of the western dolomites fig. 2 landslide scarps and deposits along the western slope of mt. zugna torta (from martin et al. 2014; elsevier used with permission). stars mark the 36cl dated samples for lavini di marco (ldm) and costa stenda (cs). red triangles mark sites of 14c-dated samples (orombelli & sauro, 1988) (cf. fig. 5). 194 fig. 4 schematic geological section of the lavini di marco and costa stenda rock avalanche deposits. samples collected along the section are also shown (from martin et al., 2014; elsevier used with permission). fig. 3 the sliding surface and the 30 m-high head scarp of lavini di marco (photo by g. griesmeier, 2019). the site is located near the ldm5 sampling site (cf. fig. 2). martin s. et al. sis, and 36cl surface exposure dating allowed to interpret the lavini di marco deposits (martin et al., 2014). the main release scarp extends from the town of marco up to mt. zugna torta, structurally controlled by the lizzana-vallone fault (fig. 4). clear bedding planes (about 20° to nw) acted as sliding planes (fig. 4). upon release, the lavini di marco debris spread out on the adige river flood plain and accumulated deposits with a marked concentric outer ridge made of monte zugna limestone, pushing the adige river to the western side of the valley (fig. 2). the ages obtained by dating the lavini di marco and costa stenda boulders cluster around 3,000 years before present (fig. 5). the two failures occurred almost simultaneously, giving a final age of 3.0 ±0.4 ka (martin et al., 2014). cosmogenic 36cl data show later failures at the head scarp during the middle ages (0.8 ±0.2 ka; samples 7 and 8 in fig. 5). published radiocarbon ages give a middle holocene age for the dosso gardene landslide (orombelli & sauro, 1988; dg in fig. 5). moreover, radiocarbon ages for the varini landslide event are broadly coincident with the younger ages of lavini di marco (orombelli & sauro, 1988; va in fig. 5). these events seem to overlap in time with a catastrophic flood event of the adige river in verona in 883 ad. in the lower part of the lavini di marco sliding surface, strata are buckle folded due to gravity (martin et al., 2014), pushing to a monitoring of the monte zugna torta slope since the 1990s (tommasi et al., 2009). before monitoring started, deformations were believed to be no longer active. this conviction having been strengthened by the high safety factors provided by limit equilibrium analyses (tommasi et al., 2009). sar satellite interferometry performed in the period 1990-2002 and probe inclinometer measures showed a very slow sliding of the slabs located uphill of the buckle folds. to strengthen this observation, buckling was backanalyzed using distinct element method (dem) and discontinuous deformation analysis (dda), and determining rock mass structure, strength and stiffness by extensive in-situ (core logging, geophysical surveys) and laboratory investigations (geotechnical tests). the studies confirmed that buckling deformations are definitely possible, in the presence of water pressure and minor flexures, suggesting that buckling deformation may evolve into failures and should therefore be considered in evaluating the long term slope stability. 3.2 termeno the termeno case study shows an example of monitoring a steep scarp with big boulders rockfall. the site affected by the landslide (freisinger hof) is located between cortaccia and termeno along the right slope of the adige valley (fig. 1). here, the mountain slope rises from the valley bottom (214 m a.s.l.) up to the mendola ridge (1800-2100 m a.s.l.). the bedrock is composed of 195 fig. 5 distribution of 36cl exposure ages (stars) for the lavini di marco and costa stenda rock avalanche deposits (sample number: age ± uncertainty) (from martin et al., 2014; elsevier used with permission). radiocarbon sites and calibrated 14c ages (triangles) from orombelli & sauro (1988) (cf. fig. 2). landslides of the western dolomites carbonate rocks and clastic sediments belonging to permo-triassic sequences (avanzini et al., 2012). uphill of cortaccia-termeno there is a 100 m-high vertical steep wall (fig. 6). here, the dolomitized limestone of the contrin formation shows almost horizontal bedding, which is cut across by pervasive orthogonal fractures. at their base, the presence of silty and clayey metapelites of the giovo formation is responsible for the formation of large carbonate towers and pinnacles over the clay layer. this configuration, reported also for other nearby sectors along the adige valley right side (avanzini et al., 2012), is responsible for systematically falling down cubic rock bodies and, in some cases, for toppling rock towers (several meters in diameter, volume up to 400 m³). for this reason, this area is one of the best examples to reconstruct and understand these types of processes. one of these events, which occurred on 21st january 2014 (at hour 23:56), is well documented by the geological survey of south tyrol (fig. 6). the area, evacuated during the night, was later examined by helicopter and photographically documented, to plan all the security measures. then, yard and power poles were protected by artificial walls, and the remaining portion of the rock tower was blasted. at the same time, a detailed orthophoto map and a digital elevation model of the 196 rockfall area were performed. special attention was paid to map trajectories of the blocks ejected during blasting (fig. 7). these observations were used for a detailed back analysis, testing, and calibrating different rockfall simulations (fig. 8). notably, there was a good agreement between observations and numerical results, not only on the trajectories, but also on the jump distances and heights, on the impact locations, and on the final position of the blocks. thus, we can rely on the accuracy of this reconstruction of the 21st january 2014 event. as a final step, the entire slope was mapped in detail, considering all the necessary parameters to carry out simulations and to adequately plan protection structures. a detailed historical analysis has been carried out in the archives of the benedictine order of freising in bavaria, which owns the farm. the buildings in the area date back to 1661 ad and provided detailed records of the agricultural activities performed since their construction. in these archives there is no mention of any rockfall that reached the buildings or the vineyards, but at least one huge block rolled down to this place along a trajectory analogous to those of the 21st january 2014 event (fig. 7b). it is probable that the impact of this event on the buildings or the vineyards would have registered in the financial records of the farm. henceforth, fig. 6 a) the rockfall in termeno (freisinger hof), occurred on 21st january 2014. b) the niche composed of contrin limestone, with remnants of hanging rocks before blasting. c) final position of a huge boulder, very close to the house. d) freisinger hof and the deep grooves made by rockfall boulders. martin s. et al. we can empirically estimate that the returning period for this event could be about 400 years. 4. rock avalanches of the sarca valley 4.1 marocche di dro the marocche di dro include some of the most impressive rock avalanche deposits in the alps (figs. 9, 10). earlier authors discussed as many as twelve different landslides, including five grouped as marocche di dro (e.g., trener, 1924). based on fieldwork, remote imagery analysis and 36cl surface exposure dating, ivyochs et al. (2017b) delimited the two main deposits, namely the marocca principale and the overlying kas (figs. 9, 11). the largest marocca principale event, when about 1000 mm3 of predominantly rotzo limestones collapsed, occurred 5.3±0.9 ka ago. the release area extends along the vertical wall from mt. casale to mt. granzoline, likely also including mt. brento (fig. 9). the marocca principale blocked the sarca river forming a dam; tens of meters of fluvial and lacustrine sediments accumulated upstream, forming the sarche plain sediments (fig. 11). on the southern side, the marocca principale deposits were covered by the younger kas event. however, the interpretation of core drilling and geophysical data suggest that further blocky deposits are lying buried beneath the plain (ivy-ochs et al., 2017b). the sarca plain remained swampy over centuries, explaining the lack of towns in the valley as testified by historical records. kas deposits show a barren, stark landscape made up of house-sized rotzo boulders, stacked in an open framework deposit (fig. 10). 36cl data show that rock failure (about 300 mm3) from the mt. brento eastern face occurred 1.1±0.2 ka ago (single ages in fig. 9). it should be noted that, within the kas deposits, 5-10 mhigh longitudinal flow ridges extend radially, outward from the release area below mt. brento (fig. 11b). during the kas event the southern portion of the marocca principale deposits was buried. the finding of roof tile fragments (probably roman in age; trener, 1924) between the two rock avalanche deposits suggests the presence of some “kasae” (rustica villae) in the valley. nevertheless, reference to this event cannot be found in any historical document. for both marocca principale and kas, an initial translational failure likely quickly evolved to massive collapse and complex failure, followed by a run-out across the valley and a run-up on the eastern slope. several factors contribute to the prevalence of rock slope failures along this reach of the sarca valley. first, the extreme relief of more than one kilometer along the mt. casale-mt. brento wall. this is attributable to miocene downcutting, amplified by undercutting by the adige glacier during the quaternary (ivy-ochs et al., 2017b 197 fig. 7 a) boulder trajectories of the termeno rockfall. b) a huge boulder located near freisinger hof since before 1661 ad (location in a, red circle). fig. 8 simulation of failures with the planned dam. left jump height. right: reach probability. landslides of the western dolomites 198 martin s. et al. and references therein). second, tectonics play a decisive role in the repeated failures. in fact, fractures and faults reduce rock mass strength. the lower sarca valley is dominated by the nne-ssw oriented, ese-to-se verging giudicarie fold-and-thrust belt. moreover, nwse oriented nearly vertical strike-slip faults, belonging to the schio-vicenza system, cut across the giudicarie faults dislocating originally adjacent structural blocks (cf. fig. 1). post-compressional reactivation of n-s oriented mesozoic normal faults and fractures facilitated backwall detachment. 4.2 molveno the molveno rock avalanche, with a volume of about 600 mm3, is probably the largest single-event rock avalanche in the brenta dolomites and one of the largest in the alps. as shown on figure 12, rock avalanche deposits dammed the valley to the north forming (or raising the level of) the lake of molveno (823 m a.s.l.) (chinaglia & fornero, 1995; sauro & zampieri, 2001). in 1951 (and again recently in spring 2017), the lake was drained and standing tree trunks of a drowned forest buried by delta deposits were discovered. detailed geomorphological mapping, cosmogenic 36cl exposure dating and numerical run-out modelling were used to reconstruct the molveno rock avalanche (von wartburg et al., 2020). due to the complicated morphology of the landslide deposits (e.g., the elevated pian delle gaorne plain in fig. 12), with evidence of internal collapses (secondary scarps within the deposit; fig. 13), the reconstruction of the source location and dynamics of the landslide remain a challenging issue. reflecting as well this complicated setting, some authors suggested that the deposits were produced by several events coming from different source areas on both sides of the valley, mt. gazza to the east and mt. soran to the west (lepsius, 1878; fuganti, 1969; chinaglia, 1992): conversely, other authors described the deposits as one large event coming from a prominent niche on mt. soran (damian, 1890; schwinner, 1912). 199 <<<<<---- -------- ---- fig. 9 geomorphological map of the rock avalanche deposits at marocche di dro, sarca valley. cosmogenic 36cl sampling sites and ages are also shown (from ivy ochs et al., 2017b; elsevier used with permission). fig. 10 the kas blocky deposit, looking southward. boulders in foreground are several meters in diameter. landslides of the western dolomites 200 fig. 11 geomorphology of the marocche di dro deposits. a) slope map. b) aspect map. c) detailed sketch of the dro and ceniga plains, where visible toma likely belong to the marocca principale deposits (from ivy ochs et al., 2017b; elsevier used with permission). martin s. et al. von wartburg et al. (2020) obtained a mean age of 4.8±0.5 ka, based on cosmogenic 36cl surface exposure dating of boulders across the deposits (fig. 12). this indicates emplacement as a single huge landslide at molveno. for this reason, the secondary collapses visible within the deposit (cf. fig. 13) likely occurred (closely) after this main event. among all the studied boulders of molveno, only the two dated ones from nembia gave ages that are about 2000 years younger (2.1±0.3 and 2.4±0.2 ka; fig. 12). it is most likely because them were covered by water until 2000 years ago (von wartburg et al., 2020). to simulate the molveno landslide and to test the reliability about only one event from mt. soran, a numerical run-out model was performed, assuming a prefailure topography (dan3d-flex code; hungr, 1995; mcdougall & hungr, 2004; aaron & hungr, 2016). the basic software (dan3d) is designed to simulate extremely rapid, flow-like, mass movements (mcdougall & hungr, 2004), while its add-in (flex) allows to model initially partially coherent landslides with planar sliding followed by rapid fragmentation (aaron & hungr, 2016). the modelling results are shown in figure 14. they well reproduce the extent of the mapped landslide, despite the predicted thickness locally show significant deviations from observations, such as at pian delle gaorne (von wartburg et al., 2020). 201 fig. 13 slope (on the left) and aspect maps (on the right) for the molveno deposits (from von wartburg et al., 2020). --------->>>>> fig. 12 terrain map of the molveno rock avalanche deposits, with geographical names and 36cl sampling sites and ages (from von wartburg et al., 2020). landslides of the western dolomites 5. discussion during the last decades, several authors have examined spatial and temporal patterns of catastrophic rock slope failures with the aim of understanding predisposing factors and triggering mechanisms, both in the dolomites (fuganti, 1969; abele, 1974; perna, 1996; borgatti et al., 2006; borgatti & soldati, 2010; martin et al., 2014; ivyochs et al., 2017a; 2017b; von wartburg et al., 2020) and generally in the alps (soldati et al., 2006; prager et al., 2008; zerathe et al., 2014; ivy-ochs et al., 2017a; singeisen et al., 2020). three periods of enhanced slope activity have been discussed: 10-9 ka, 5-3 ka, and 21 ka, the latter especially for the southern alps. a summary of all the large (>1 mm3) dated landslides in the alps is shown in figure 15. 5.1 bedrock structure and tectonics the rock avalanches and landslides described herein have clear similarities regarding lithology and structural setting, as they belong to the same tectonic domain: the western trentino crustal block (viganò et al., 2015). the lavini di marco, marocche di dro and molveno rock avalanches are developed in jurassic limestones, specifically rotzo, loppio and tofino formations, which are characterized by the presence of cm-dm thick clay intercalations that can facilitate sliding. numerous rock slope failures are concentrated in this distinctive area which is constrained between two large, deeply rooted rigid domains: the athesian volcanic high (bargossi et al., 1998) to the northeast and the adamello intrusions to the west (fig. 1). between these two domains, late alpine deformation, due to counterclockwise motion of adria, predominantly along the schio-vicenza fault with shortening of the western trentino block, was strongly constrained within the giudicarie belt. most of the deformation was concentrated along the southern giudicarie master fault bordering the adamello but also along minor faults of this system. accordingly, the landslide deposits studied here are concentrated along faults that belong to the nne-trending southern giudicarie and to the nw-trending schio-vicenza fault systems, or lay at the junction of those two systems (castellarin et al., 2005). along the giudicarie, asymmetric folds at the kilometer scale also occur. these generate a geological setting dominated by west-dipping monoclinic surfaces and east-facing tectonic scarps. the associated synclines host respectively lake garda, sarca valley and the molveno lake. within this framework, rock masses detached along the dip slope bedding planes associated with clay-rich interbeds on the west-facing slopes, as for example at lavini di marco. on the east-facing slopes of the sarca valley, toppling and massive collapse are the dominant processes (perna, 1974; 1996), such as the marocca principale rock avalanche. the 202 numerous faults and fractures associated with these major tectonic systems exert strong control on vertical detachment surfaces (i.e. back walls and side walls), as discussed above for the nnw-trending lizzana-vallone fault at lavini di marco and the nw-oriented steep side wall in the molveno release area (cf. figs. 4, 12). finally, in these mountainous areas, rock damage and associated fatigue and reduction in strength due to past tectonics (brideau et al., 2009) and recent active deformation pose the question of the present and future hazards of these inhabited alpine valleys. 5.2 landslide timing and driving forces very few events in the alps have been dated to the lateglacial (18-12 ka). therefore, the concept that the huge landslides in trentino, or the alps overall, occurred during the early lateglacial directly following ice retreat, implicating debuttressing as a driving force, can now be discounted based on the numerous ages presented in figure 15. even for two of the oldest dated landslides in the alps (flims, koefels), it is important to note that glaciers had not occupied those valleys for many thousand years prior to the catastrophic events (ivy-ochs, 2015). two of the largest events in the alps, flims (10-12 km3) and koefels (3 km3), have been dated to the period 10 to 9 ka ago (ivy-ochs et al., 2017b and references therein). early holocene rock slope failure events may be related to marked warming at 10.5-10.0 ka that forced retreat of glaciers to positions perhaps even smaller than today’s and was likely accompanied by rapid permafrost degradation at higher elevations. however, a seismic trigger has been recently suggested for some coeval early holocene landslides in the kander region (grämiger et al., 2016). recent fig. 14 time series of the run-out model for the molveno rock-avalanche. the extent of the observed deposit is well reproduced (from von wartburg et al., 2020). martin s. et al. 36cl dating of the kandersteg deposits (location shown in fig. 15) has revealed that this huge event (1.1 km3) occurred 3.2 ±0.2 ka ago (singeisen et al., 2020) and not 9.6 ka ago as previously proposed. this significantly weakens the concept of an early holocene cluster of major events. no failure events in the lower sarca or adige valleys have yet been dated to the lateglacial or early holocene. nevertheless, in both valleys, the presence of landslide deposits buried beneath alluvial fill cannot be ruled out, especially when one considers to the huge volume of rock missing along the mt. brentomt. casale mountain front (ivy-ochs et al., 2017b). numerous authors identify a period of increased landslide activity between 5 and 3 ka in the alps and specifically in the dolomites (panizza et al., 1996; dapples et al., 2003; prager et al., 2008; borgatti & soldati, 2010; zerathe et al., 2014). in the lower sarca and adige valleys and nearby regions, several mass wasting events have been dated to this period (perna, 1996; baroni et al., 2014). at lavini di marco the most extensive deposit was dated to 3.0 ±0.4 ka with 36cl (martin et al., 2014). both molveno, 4.8 ±0.5 ka (von wartburg et al., 2020), and marocca principale, 5.3 ±0.9 ka, fall as well within the discussed time interval. zerathe et al. (2014) point out that different proxies in the alps suggest a “4.2 ka” wet climatic event with associated enhanced rock slope failure activity. similarly, periods of climate degradation characterized by more frequent flooding episodes and extreme meteorological events have been recorded in the same timeframe (wirth et al., 2013; benito et al., 2015; rossato et al., 2015). under such conditions, stress field changes in the rock due to the added mass of water as well as weakening of clayrich interbeds may have led to catastrophic failure. this agrees with the opinions of soldati et al. (2004) and borgatti & soldati (2010) for rock avalanches of the eastern dolomites. nevertheless, several researchers underline the importance of strong tectonic events as triggers for the middle holocene rock avalanches (ambrosi & crosta, 2006; prager et al., 2008). indeed, fig. 15 compilation of isotopically dated and historical large (>1 mm3) landslides in the alps (modified and updated from ivy-ochs et al., 2017b; elsevier used with permission). updates include the late holocene kandersteg (kan), the middle holocene molveno (mol), the late holocene masiere di vedana (mdv) (rossato et al., 2020a) and the tovel (tov) events. alm almtal; plz pletzachkogel; chi chironico; dgw durchgangwald; rau rautispitz; dau daubensee; klr klein rinderhorn; koe koefels; tam tamins; flm flims; obr obernberg; vv val viola; vig vigaun; wild wildalpen; plt platten; mp marocca principale; lau lauvitel; fp fernpass; eib eibse; bar barwies; tum tumpen; hint hintersee; kan kandersteg; brv brenva; ldm lavini di marco; tsch tschirgant; mol molveno; haim haiming; petz petzer oberloibach; mat matrei; mdv masiere di vedana; fad fadalto; var varini; kas; cp castelpietra; pdl prà da lago; mg mont granier; dob dobratsch; sgn san giovanni nago; bia biasca; bf becca france; dis disentis; plu plurs; bor borta; dia diableret; vf val ferret; lda lago di alleghe; gold goldau; elm; vaj vajont; vp val pola; ran randa; clp la clapiere; pra prättigau; ab alta badia; cor cortina; swa southwestern alps; sec sechiellene; tov tovel. 203 landslides of the western dolomites the notable overlap in the ages of the molveno and marocca principale events which lie no more than 10 km apart (fig. 1), may implicate a common seismic trigger (von wartburg et al., 2020). recent landslide activity in the western dolomites, especially over the last several thousand years, is suggested to be related to seismic activity (borgatti & soldati, 2010; ivy-ochs et al., 2017a; 2017b). numerous catastrophic landslides are reported for postroman times, albeit somewhat schematically (heim, 1932; eisbacher & clague, 1984; abele, 1997 and references therein). sauro & zampieri (2001) suggest a third temporal cluster in the southern alps around 1000 ad, which was strongly related to neotectonics. in the presented data set, this would include, the kas landslide (ivy-ochs et al., 2017b), the youngest dated events at lavini di marco (martin et al., 2014), the varini rockslide (orombelli & sauro, 1988) and the castelpietra landslide (ivy-ochs et al., 2017a). lake garda, the lower sarca and adige valleys are characterized by low-to-moderate magnitude seismicity (moment magnitude <6.0; basili et al., 2008), which is interpreted as mainly due to activity of the southern giudicarie fault system (viganò et al., 2013; 2015). other sources of seismicity are the faults of the schio-vicenza system (viganò et al., 2015), and the thrusts between brescia and verona that also bear evidence of middle pleistocene to holocene activity. compilations of historical seismicity (guidoboni et al., 2018; rovida et al., 2019) allowed to evaluate the earthquakes, especially if intended as seismic sequences, as a possible driving/ triggering factor for landslides and rock avalanches in the study region. based on the available compilations of historical seismicity, two strong earthquakes struck southern trentino and the central po plain around 1000 ad. they are the “middle adige valley” event dated to 1046 ad (estimated epicentral intensity ix mcs, mercalli-cancani-sieberg scale) and the “verona” earthquake in 1117 ad (estimated epicentral intensity ix mcs; guidoboni et al., 2018). although there are significant uncertainties associated with the epicentral coordinates of the 1046 ad “middle adige valley” earthquake, its location (guidoboni & comastri, 2005) is considerably closer to both the kas and castelpietra deposits (location shown on fig. 1) than the 1117 ad earthquake location (about 72 and 80 km, respectively). castelpietra, dated to 1.0 ±0.3 ka ago, and kas sites lie about 6 and 11 km, respectively, epicentral distance from the “middle adige valley” earthquake location (ivy-ochs et al., 2017a). 6. conclusions in this overview, selected landslides of the western dolomites have been discussed and their age compared with other cases in the alps. local active tectonic setting plays a decisive role in the repeated failure along slopes, which is localized along faults of the nnetrending southern giudicarie and the nw-trending schio-vicenza fault systems. west-dipping monoclinic surfaces provide the dip slope and shale interbeds in the limestones facilitate sliding, as for example at lavini di marco. faults and fractures localize backwall detach 204 ment; strike-slip faults focus lateral constraints for detaching blocks. east-facing tectonic scarps promote toppling and massive collapse, as for example at marocche di dro (marocca principale and kas rock avalanches). during both events at marocche, and at molveno, complex failure was followed by run-out across the valley and tens of meters of run-up on the opposite slope. smaller rockfalls may occur due to similar tectonic settings, as in the case of termeno. here, the volume of the debris was smaller, and the mass propagated as single blocks, rolling, and jumping. the ages of the discussed rock avalanches and landslides of the sarca and adige valleys mainly fall in the period 5-3 ka ago. this period broadly coincides with that of increased frequency for failure events, at the transition from the middle to the late holocene, when a shift to a wetter, colder climate occurred. nevertheless, a seismic driving factor is suggested for the landslides of this area. although the verona earthquake (1117 ad) may have had a greater impact regionally, we suggest the “middle adige valley” (1046 ad) seismic sequence, whose epicentral distance is much closer to the sarca valley, as relevant driving force for the kas rock avalanche (1.1 ±0.2 ka). aknowledgements the authors are grateful to prof. mauro soldati and dr. gioachino roberti for their useful comments and suggestions. the authors thank also prof. paolo mozzi, that handled the article. references aaron j., hungr o. (2016) dynamic simulation of the motion of partially-coherent landslides. engineering geology, 205, 1-11. abele g. (1974) bergstürze in den alpen. in: ihre verbreitung, morphologie und folgeerscheinungen. wiss. alpenvereinshefte, münchen, 25, p. 230. abele g. (1997) influence of glacier and climatic variation on rockslide activity in the alps. in: matthews j.a., brunsden b., frenzel b., gläser b., weiss m.m. (eds.), rapid mass movement as a source of climatic evidence for the holocene, palaoklimaforschung, vol. 19. fischer, stuttgart, 1-6. alighieri d. (1314) inferno, divina commedia, xii, 4-9. annales fuldenses. sive annales regni francorum orientalis. hannover: hahnsche buchhandlung, 1978, (ripr. dell’ed.: hannoverae: impensis bibliopolii hahniani, 1891), pp. 100. ambrosi c., crosta g.b. (2006) large sackung along major tectonic features in the central italian alps. engineering geology, 83, 183-200. avanzini m., bargossi g.m., borsato a., cucato m., morelli c., picotti v., selli l. (2012) note illustrative della carta geologica d’italia alla scala 1:50.000, foglio n. 043, mezzolombardo, pp. 252. bargossi g. m., rottura a., vernia l., visonà d., tranne c.a. (1998) guida all'escursione sul distretto vulcanico atesino e sulle plutoniti di bressanonechiusa e cima d'asta. memorie della società geologica italiana, 53, 23-41. baroni c., martino s., salvatore m.c., scarascia mu martin s. et al. gnozza g., schirilò l. (2014) thermomechanical stress-strain numerical modelling of deglaciation since the last glacial maximum in the adamello group (raethian alps, italy). geomorphology, 226, 278-299. basili r., valensise g., vannoli p., burrato p., fracassi u., mariano s., tiberti m.m., boschi e. (2008) the database of individual seismogenic sources (diss), version 3: summarizing 20 years of research on italy's earthquake geology. tectonophysics, 453, 20-43. doi: 10.1016/j.tecto.2007.04.014 benito g., macklin m.g., panin a., rossato s., fontana a., jones a.f., machado m.j., matlakhova e., mozzi p., zielhofer c. (2015) recurring flood distribution patterns related to short-term holocene climatic variability. scientific reports, 5, 16398. doi: 10.1038/srep16398 borgatti l., ravazzi c., donegana m., corsini a., marchetti m., soldati m. (2006) a lacustrine record of early holocene watershed events and vegetation history, corvara in badia, dolomites. italy. j. quaternary sci., 22 (2), 173-189. borgatti l., soldati m. (2010) landslides as a geomorphological proxy for climate change: a record from the dolomites (northern italy). geomorphology, 120, 56-64. brideau m.a., yan m., stead d. (2009) the role of tectonic damage and brittle rock fracture in the development of large rock slope failures, geomorphology, 103(1), 30-49. doi: 10.1016/j.geomorph.2008.04.010 carton a. (2017) large ancient landslides in trentino, northeastern alps, as evidence of postglacial dynamics. in: m. soldati & m. marchetti (eds.), landscapes and landforms of italy. springer international publishing, cham, 113-122. doi: 10.1007/978-3-319-26194-2_9 castellarin a., picotti v., cantelli l., claps m., trombetta l., selli l., carton a., borsato a., daminato f., nardin m., santuliana e., veronesi l., bollettinari g. (2005) note illustrative della carta geologica d’italia alla scala 1:50.000, foglio n. 080, riva del garda, pp. 145. chinaglia n. (1992) le "marocche" della bassa valle del sarca: scivolamenti planari in unità calcaree stratificate. i convegno nazionale dei giovani ricercatori in geologia applicata, 47-56. chinaglia n., fornero e. (1995) ipotesi sulla possibile evoluzione cinematica di un movimento profondo di versante: l'esempio del m. soran (trentino meridionale) memorie della società geologica italiana, 50, 101-108. damian j. (1890) der molvenosee in tirol. a. petermanns mitteilungen aus justus perthes' geographischer anstalt, 262-270. dapples f., oswald d., raetzo h., lardelli t., zwahlen p. (2003) new records of holocene landslide activity in the western and eastern swiss alps: implication of climate and vegetation changes. eclogae geol. helv., 96, 1-9. eisbacher g.h., clague j.j. (1984) destructive mass movements in the high mountains: hazard and management. geol. survey canada, 84/16, p. 229. fuganti a. (1969) studio geologico di sei grandi frane nella regione trentino-alto adige (marco, molveno, prà del finocchio, malgrè, sasso englar, rasciera). mem. mus. tr. sci. nat. 17, 5-69. grämiger l.m., moore j.r., vockenhuber c., aaron j., hajdas i., ivy-ochs s. (2016) two early holocene rock avalanches in the bernese alps (rinderhorn, switzerland). geomorphology, 268, 207-221 guidoboni e., comastri a. (2005) catalogue of earthquakes and tsunamis in the mediterranean area from the 11th to the 15th century. istituto nazionale di geofisica e vulcanologia, storia geofisica ambiente, bologna, italy, pp.1037. guidoboni e., ferrari, g., mariotti d., comastri a., tarabusi g., sgattoni g., valensise g., (2018) cfti5med, catalogo dei forti terremoti in italia (461 a.c.-1997) e nell’area mediterranea (760 a.c.1500). istituto nazionale di geofisica e vulcanologia (ingv). doi: 10.6092/ingv.it-cfti5 heim a. (1932) bergsturz und menschenleben. vierteljahrschr. d. naturf. ges. jg., zürich, 77, pp. 218. hungr o. (1995) a model for the runout analysis of rapid flow slides, debris flows, and avalanches. canadian geotechnical journal, 32, 610-623. hungr o., leroueil s., picarelli l. (2014). the varnes classification of landslide types, an update. landslides, 11(2), 167-194. ivy-ochs s. (2015) glacier variations in the european alps at the end of the last glaciation. cuad. investig. geografica 41, 295-315. ivy-ochs s., martin s., campedel p., hippe k., vockenhuber c., carugati g., rigo m., pasqual d., viganò a. (2017a) geomorphology and age of large rock avalanches in trentino (italy): castelpietra. in: mikoš m., vilímek v., yin y., sassa k. (eds.) advancing culture of living with landslides. wlf 2017. springer, cham, 347-353. ivy-ochs s., martin s., campedel p., hippe k., alfimov v., vockenhuber c., andreotti e., carugati g., pasqual d., rigo m., viganò a. (2017b) geomorphology and age of the marocche di dro rock avalanches (trentino, italy). quat. sci. rev., 169, 188205. lepsius r. (1878) das westliche südtirol: geologisch dargest. hertz, pp. 375. martin s., campedel p., ivy-ochs s., viganò a., alfimov v., vockenhuber c., andreotti e., carugati g., pasqual d., rigo m. (2014) lavini di marco (trentino, italy): 36ci exposure dating of a polyphase rock avalanche. quat. geochron., 19, 106-116. mcdougall s., hungr o. (2004) a model for the analysis of rapid landslide motion across threedimensional terrain. canadian geotechnical journal, 41, 1084-1097. noriller g.b. (1871) i lavini di marco. rovereto, pp. 237. oetheimer c. (1989) etude géomorphologique des éboulements remaniés de la vallée de tovel: contribution à la connaissance des «marocche» du trentin (italie). studi trentini di scienze naturali. acta geologica, 65, 3-47. 205 landslides of the western dolomites orombelli g., sauro u. (1988) i lavini di marco: un gruppo di frane oloceniche nel contesto morfotettonico dell’alta val lagarina (trentino). suppl. geogr. fis., dinam. quater., 1, 107-116. panizza m., pasuto a., silvano s., soldati m. (1996) temporal occurrence and activity of landslides in the area of cortina d’ampezzo (dolomites, italy). geomorphology, 15, 311-326. penck a. (1886) die “slavini di s. marco”. die alpen im eiszeitalter. c.h. tauchnitz leipzig, 3, pp. 1200. penck a., brückner e. (1909) die alpen im eiszeitalter. dritter band. die eiszeiten in den sudalpen und im bereich der ostabdachung der alpen. ed. tauchnitz, lipsia, pp. 1199. perna g. (1974) le frane glaciali e postglaciali nel trentino meridionale (“marocche” e “laste”). boll. com. glaciol. it., 22, 59-66. perna g. (1975) laste e marocche nel basso trentino. economia trentina 4, 37-44, trento. perna g. (1996) itinerari geologici: inquadramento cronologico delle grandi frane quaternarie delle valli dei laghi e del basso sarca (trentino) economia trentina, 3, 55-89 (trento). perna g., sauro u. (1978) atlante delle microforme di dissoluzione carsica superficiale del trentino e del veneto. mem. mus. trident. sci. nat. 22, 1-176. prager c., zangerl c., patzelt g., brandner r. (2008) age distribution of fossil landslides in the tyrol (austria) and its surrounding areas. nat. hazards earth syst. sci., 8, 377-407. rossato s., fontana a., mozzi p. (2015) metaanalysis of a holocene 14c database for the detection of paleohydrological crisis in the venetianfriulian plain (ne italy). catena, 130, 34-45. doi: 10.1016/j.catena.2014.10.033 rossato s., ivy-ochs s., martin s., viganò a., vockenhuber c., rigo m., monegato g., de zorzi m., surian n., campedel p., mozzi p. (2020a) structural and climate drivers of the historic masiere di vedana rock avalanche (belluno dolomites, ne italy), natural hazards and earth system sciences, 20,2157-2174. doi: 10.5194/nhess-2019-413 rossato s., ghirotti m., gabrieli f., livio f., bovo f., brezzi l., campedel p., cola s., ivy-ochs s., martin s., mozzi p., pasuto a., rigo m., simonini p., surian n., viganò a., vockenhuber c., wolter a. (2020b) learning from the past to face the future: landslides in the piave valley (eastern alps, italy). alpine and mediterranean quaternary, 33, 2, 209228. doi:10.26382/amq.2020.14 rovida a., locati m., camassi r., lolli b., gasperini p. (2019) cpti15, the 2.0 version of the parametric catalogue of italian earthquakes. istituto nazionale di geofisica e vulcanologia, italy. doi: 10.13127/cpti/cpti15.2 sauro u., zampieri d. (2001) evidence of recent surface faulting and surface rupture in the fore-alps of veneto and trentino (ne italy). geomorphology, 40, 169-184. schwinner r. (1912) der mte. spinale bei campiglio und andere bergstürze in den südalpen. austrian 206 journal of earth sciences, 5, 127-197. singeisen c., ivy-ochs s., wolter a., steinemann o., akçar n., yesilyurt s., vockenhuber c. (2020) the kandersteg rock avalanche (switzerland): integrated analysis of a late holocene catastrophic event. landslides, 17, 1297-1317. soldati m., corsini a., pasuto a. (2004) landslides and climate change in the italian dolomites since the late glacial. catena 55, 141-161. soldati m., borgatti l., cavallin a., de amicis m., frigerio s., giardino m., mortara g., pellegrini g.b., ravazzi c., surian n., tellini c., zanchi a., in collaboration with alberto w., albanese d., chelli a., corsini a., marchetti m., palomba m., panizza m. (2006) geomorphological evolution of slopes and climate changes in northern italy during the late quaternary: spatial and temporal distribution of landslides and landscape sensitivity implications. geogr. fis. dinam. quat., 29(2), 165-183. taramelli t. (1881) di alcuni scoscendimenti postglaciali sulle alpi meridionali. rendiconti del reale istituto lombardo, s. 11, p. xiv, 111, pp. 7. tommasi p., verrucci l., campedel p., veronese l., pettinelli e., ribacchi r. (2009) buckling of high slopes: the case of lavini di marco (trento-italy). engineering geology, 109 (1-2), 93-108. doi: 10.1016/j.enggeo.2009.02.002 trener g.b. (1924) gli impianti idroelettrici della città di trento, ii. geologia delle marocche, 25-33 con carta geologica 1:25.000 studi trentini sci. nat., 34 (2), 319-340. viganò a., scafidi d., martin s., spallarossa d. (2013) structure and properties of the adriatic crust in the central-eastern southern alps (italy) from local earthquake tomography. terra nova, 25, 504-512. viganò a., scafidi d., ranalli g., martin s., della vedova b., spallarossa d. (2015) earthquake relocations, crustal rheology, and active deformation in the central-eastern alps (n italy). tectonophysics, 661, 81-98. viganò a., zampieri d., rossato s., martin s., selli l., prosser g., ivy-ochs s., campedel p., fedrizzi f., franceschi m., rigo m. (2018) past to present deformation of the central-eastern southern alps: from the foreland to the giudicarie belt. in: geological field trips and maps 2018. periodico semestrale del servizio geologico d’italia ispra e della società geologica italiana 10(1.1) pp. 78. doi: 10.3301/gft.2018.01 von wartburg j., ivy-ochs s., aaron j., martin s., leith k., rigo m., vockenhuber c., campedel p., viganò a. (2020) constraining the age and source area of the molveno landslide deposits in the brenta group, trentino dolomites (italy). frontiers in earth sciences, 8, 164. doi: 10.3389/feart.2020.00164 wirth s.b., glur l., gilli a., anselmetti f.s. (2013) holocene flood frequency across the central alps solar forcing and evidence for variations in north atlantic atmospheric circulation. quaternary science reviews, 80, 112-128. doi: 10.1016/j.quascirev.2013.09.002 zerathe s., lebourg t., braucher r., bourlès d. (2014) martin s. et al. mid-holocene cluster of large-scale landslides revealed in the southwestern alps by 36cl dating. insight on an alpine-scale landslide activity. quaternary science reviews, 90, 106-127. doi: 10.1016/j.quascirev.2014.02.015 207 ms. received: july 21, 2020 revised: november 15, 2020 accepted: december 7, 2020 available online: december 20, 2020 landslides of the western dolomites 208 amq29(2) 1 vai 113-121 nag.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 29 (2), 2016, 113 121 ancient dna studies stefania vai, martina lari, david caramelli dipartimento di biologia, università degli studi di firenze, firenze, italy corresponding author: s. vai <stefania.vai@unifi.it> abstract: about three decades of scientific research confirmed ancient dna as a powerful tool for anthropology, paleontology, molecular evolution, conservation genetics and forensics. a rapid evolution of the methodological approaches in the last ten years led to an important increase of data related both to the number of samples and to the informative genetic markers. paleogenetics analysis has been applied to a wide spectrum of samples, answering to different kind of scientific and cultural questions. in this review, ancient dna characteristics and methodological approaches are presented as well as recent results obtained from samples of bacteria, plants, animals, with a particular focus on the newest discoveries about the homo genus. keywords: ancient dna, adna, paleogenetics 1. introduction the first data obtained from ancient dna samples were published in 1984, when higuchi et al. (1984) presented the results obtained from a tissue samples of a museum specimen of the quagga, a zebra-like species (equus quagga) extinct one hundred years before. in 1985 svante pääbo published the recovering of genetic material from an egyptian mummy (pääbo, 1985). the first results obtained from bone tissue date back to 1989 (hagelberg et al., 1989). in thirty years from these first attempts, huge innovations in methodology, signed by the polymerase chain reaction (pcr) first and the next generation sequencing (ngs) later, allowed researchers to understand the characteristics of the ancient dna, to better recognize it from possible modern dna contaminations and to obtain a large amount of data useful for different kinds of applications. after the first work by higuchi where 299 nucleotides of the mitochondrial genome of the quagga were sequenced, data for the whole nuclear genome of this species were obtained (jonsson et al., 2014). after the first attempt by pääbo, the complexity of recovering authentic ancient molecular data from human remains was better defined and sophisticated experimental procedures and bioinformatics tools were developed in order to obtain reliable results. 2. ancient dna, definition and characteristics despite its name, ancient dna (adna) has no age. this expression defines degraded dna, and degradation of genetic material starts immediately after the dead of the organism or when a biological trace is left in the environment. for this reason, both paleontological and historical samples and more recent traces analyzed in forensic contexts can be considered as adna. the starting material includes samples such as bones, hair, mummified tissues, coprolites, sediments, vegetable remains, and the temporal limits reached so far are about 400,000 years for samples recovered in caves from temperate regions (meyer et al., 2014) and about 700,000 years for samples preserved in permafrost (orlando et al., 2013). adna has particular characteristics due to the degradation of the genetic material mainly occurring by hydrolysis and oxidation led by factors such as temperature, humidity and ph. often, when the genetic material extracted from a degraded sample is analyzed, the majority of the dna can be referred to a microbial origin and only a little percentage belongs to the organism from which the sample comes (fig. 1). dna degradation determines not only the loss of the genetic material, but also the high fragmentation of the surviving component fig. 1 graphical representation of the dna content of an ancient sample (data unpublished). work presented during the aiqua scientific conferences "waiting for the nagoya inqua xix congress", held in florence, june 18 19, 2015 114 vai s. et al. fig. 2. misincorporation pattern for a human sample dated 4700 bp (data unpublished). the four upper mini-plots show the base frequency outside and in the read (the open grey box corresponds to the read). the bottom plots are the positions' specific substitutions from the 5" (left) and the 3" end (right). the c>t substitutions are in red, the g>a substitutions are in blue. the estimation was performed using mapdamage 2.0 (ginolhac et al., 2011). 115 ancient dna studies that is usually characterized by dna fragments of short length (krause et al., 2010a). another typical form of degradation that characterizes the adna is the deamination of the cytosine, that is translated in a misincorporation event during the determination of the dna sequence where an original c (cytosine) is converted in t (thymine), or an original g (guanine) is substituted by a a (adenine) when the damage involves the opposite dna strand (brotherton et al., 2007). these misincorporations occur on the adna molecules following a particular pattern: their frequency increases at the ends of the molecules (briggs et al., 2007) (fig. 2). these characteristics determine the need of a specific experimental workflow designed for recovering highly degraded molecules, but represent in the meantime an informative source that allow to discriminate between authentic ancient endogenous dna from possible modern contaminants. 3. methods for the study of adna specific criteria have been developed for working with adna. a first important advantage is provided by an appropriate behavior in sample recovering in order to avoid the contamination during handling of the remain wearing sterile gloves, masks and special or disposable clothes (pilli et al., 2013). the laboratory where the molecular analysis is performed, has to be exclusively dedicated to adna with a physical separation between the pre-amplification and the post-amplification sections and devices for sterilizing the working areas. some years ago, the only methodological approach available for adna studies was based on pcr, cloning and sanger sequencing. following this strategy, a target dna region is selected and amplified by pcr, obtaining an exponential increase of the number of molecules of interest. the pcr product is cloned using a plasmid vector and bacterial cells. isolating and reproducing single molecules of the pcr product in the bacterial cells, it is possible to sequence independently each amplicon that consists on a bacterial colony carrying several copies of a single original dna molecule obtained by pcr. in this way the sequence of numerous molecules selected by pcr is determined, giving the possibility to observe the possible presence of multiple biological sources and of misincorporations (fulton and stiller, 2012). using this methodological approach, it is necessary to have a prior knowledge of the target sequence in order to design the primers needed for the amplification and the whole target sequence (primers annealing regions included) have to be preserved intact in the ancient sample. furthermore a minimum fragment length of about 60bp is required for the molecules to be recovered by pcr. this requirements represent a limitation for highly degraded samples with really short dna fragments. the so-called golden criteria were developed to assess the authenticity of the results obtained by pcr (cooper and poinar, 2000). with the more recent ngs approach, universal adapters are ligated to the dna fragment, independently from their sequence or length (briggs and heyn, 2012). every kind of dna molecule can be potentially recovered, without modifying its original characteristics that can be then used for assessing its authenticity as ancient. barcodes can be added to the dna fragments together with the adapters, creating the so-called dna library. with this strategy is possible to process numerous samples in parallel producing a large amount of sequence data, even whole genomes, and consequently more information. since the endogenous dna could be represented in a small percentage in the sample, usually the ngs approach is flanked by a strategy of target enrichment using baits complementary to the sequences of interest, in order to increase their relative amount. the hybridization between baits and target molecules is usually performed in solution with a bead-based capture approach (carpenter et al., 2013; maricic et al., 2010). the sequencing of the whole library (shotgun approach) or of the enriched one produces a big amount of data and specific bioinformatics pipelines have been developed for handling them taking into account the characteristic of the adna. software for filtering the data according to quality and length such as fastqprocessing (kircher, 2012), mapping and assembling procedures as mia (green et al., 2008), specific procedures for misincorporation pattern analysis (ginolhac et al., 2011) and contamination estimation (fu et al., 2013), as well as more complete pipelines like paleomix (schubert et al., 2014) or schmutzi (renaud et al., 2015) are available. guidelines for ngs work on ancient dna were also proposed (knapp et al., 2015). 4. ancient dna studies adna data represents an informative source that have application in different fields. the range of possible starting material is wide, and the questions that can receive a contribution from the paleogenetics involve topics related for example to the study of evolution and phylogenesis contributing to anthropological, archaeozoological and archaeobotanical studies and of archaeology, cultural heritage and fauna and flora conservation. adna studies on bacteria as previously described, most of the dna preserved in an ancient sample usually belongs to microorganisms. characterization of the microbial diversity in horse bones from a time span between 200 and 13,000 years ago, consisted in site-specific microbial profiles that allow to characterize the environment from which the samples were recovered (der sarkissian et al. 2014). however, the majority of data belonged to a recent bacterial colonization of the bones. this observation implies that the characterization of authentic ancient microbial remains is a complex process that requires specific methodological devices. in the last years, a particular interest was focused on the analysis of the oral microbiota in human samples, in order to reconstruct its possible variations during time linked to specific subsistence and cultural shifts occurred in human history. the starting material for this kind of studies is the dental calculus (plaque), that showed to preserve a record of the microorganism composition of the oral cavity, including bacteria involved in 116 local and systemic diseases, as well as molecular information about host immunity and diet (warinner et al., 2014; weyrich et al., 2015). the neolithic revolution, began about 10,000 years ago, with the shift toward a carbohydrate-rich diet, and the recent employment of industrial processed sugar and flour started around 1850, determined major changes in the microbial oral community. disease-associated configuration remained constant between neolithic and medieval times, then the cariogenic bacteria became dominant with the industrial revolution, with a general less diverse microbial profile in modern populations (adler et al., 2013). another research field is about the reconstruction of ancient pathogens’ genomes in order to clarify the phylogenesis of such species, to understand the relationship between different strains, and to identify possible polymorphisms related to virulence. the whole genome of mycobacterium leprae was determined from medieval leprosy cases and its comparison with modern strains revealed remarkable genomic conservation during time (schuenemann et al., 2013). differently, the analysis of whole genomes of the medieval strain of yersinia pestis recovered from victims of the black death revealed that this variant of the bacterium may no longer exists, but it is probably ancestral to the modern strains. the epidemiological differences in time seem to be not related to genetic differences, but to other factors such as environment, host susceptibility or vector dynamics (bos et al., 2011; schuenemann et al., 2011). adna studies on plant remains data about adna from vegetable remains are not so numerous, since it is difficult to extract genetic material from ancient plants that often also contain inhibitory substances that interfere with some experimental procedures. despite these difficulties, archaeobotanical samples can provide information about species identification, domestication and evolutive processes. genetic material can be found in different kind of samples: wood, fruits, leaves, seeds and pollen in archaeological or herbarium specimens. dna of vegetable origin can be preserved also in feces (wood et al., 2012) and dental calculus (weyrich et al., 2015) providing information about diet. also sediments are a source for plant dna revealing the vegetation distinctive of past times even in absence of macrofossil evidences (willerslev et al., 2003). paleoenvironmental studies on sedimentary ancient dna permit to reconstruct the plant cover history and to understand the changes during time due to climate or human activities (pansu et al., 2015). with the same approach, it is possible to attest the presence of domestic plants in sediments, better defining the chronology of the neolithic transition (smith et al., 2015). comparing genetic data between different wild and domestic forms, it is possible to identify the original variants from which the domestication occurred, to follow routes of diffusion related with the anthropic exploitation and to give information about both the vegetal and human history. it is also possible to identify genetic loci under selection during domestication for adaptation to climatic and cultural contexts, such as drought and sugar content (allaby et al., 2014; allaby et al., 2015; da fonseca et al., 2015; palmer et al., 2012). adna studies on animals genomes of extinct species is a powerful tool to understand their phylogenetic relationships with extant forms. many paleogenomics studies have been conducted on faunal remains. the nuclear genome of several woolly mammoths was sequenced, defining with higher resolution the phylogenetic tree of the elephantids. some differences with functional effects were found between mammoth and elephant and in some cases variants were probably positively selected in the mammoth lineage. intra-population differences, that were not evident from the fossil records, were also highlighted (miller et al., 2008). the most ancient genome determined so far is from a horse sample preserved in permafrost dated between 560-780 thousand years bp. by comparing this sequence with those of other ancient and modern horse and donkey samples, the most recent common ancestor of the genus equus was dated to 4.0-4.5 million years bp. interestingly, multiple population size fluctuations related to climate changes have been attested in the history of this taxa, as well as particular genomic regions have been found to be possibly selected during domestication (orlando et al., 2013). about domestication process, several researches have been conducted in order to identify the area where it took place, the possible routes followed by the spread of the livestock and the possible admixture with wild local forms. while the history of the domestication of sheep and goat is rather simple to be reconstructed since the wild forms were limited to the fertile crescent before neolithic, the dynamics related to the domestication of cattle and pig could be more complex because the wild forms of bos taurus primigenius and sus scrofa were spread in a wider area. ancient and modern dna data collected from europe, western anatolia and iran, shown that the domestication of cattle occurred as a single process in the near east in the 9th millennium bc. with the neolithic transition, the domestic form spread into europe with no significant interbreeding with the local wild individuals (scheu et al., 2015) even if some haplotype sharing between preand post-neolithic samples in southern europe suggests a possible contribution from the wild local forms in particular areas (bejapereira et al., 2006; lari et al., 2011; mona et al., 2010). several studies on ancient and modern dna were conducted in order to understand the dynamics related to the swine domestication. a phylogeographic approach suggested the origin of the domestic form in the near east, its spread in europe during the neolithic diffusion, then a local domestication of the european wild boar. a later replacement of the eastern lineages by the european ones occurred not only in europe but also in asia minor during the bronze age (larson et al., 2007; ottoni et al., 2013). a recent contribution demonstrated that also natural population dynamics, occurred independently of domestication, can determine the variation in frequency and distribution of such genetic lineages. a so -called near eastern haplotype, previously considered as marker of the neolithization wave from near east, was found in italian samples two thousand years before the arrival of the neolithic culture in that area (vai et al., 2015). this example shows that the reconstructions of vai s. et al. past events are always open to new developments as new samples are analyzed covering new geographical areas and new chronological periods, as well as more genetic markers are considered. adna studies on genus homo particular interest focused on the study of human species, in order to clarify the relationships between different forms that in some cases shared the same geographical areas in the same period, such as neandertals and early anatomically modern humans (emhs). genetic variation of neandertals has been explored in several studies, starting with the methodological approach based on pcr for studying particular loci followed by the sequencing of the whole genome by ngs. genetic discontinuity between this extinct human form and extant and ancient modern humans was already attested analyzing a portion of the mitochondrion (mtdna) (krings et al., 2000; caramelli et al., 2003) and was confirmed when the whole mtdna genome was determined in 2008, confirming that the neandertal mtdna falls outside the variation of modern humans with an estimation of the divergence time around 660,000 years ago (green et al., 2008). analyzing more neandertal individuals, it was possible to identify a possible genetic structure at intra-population level, probably related with the geographical and/or temporal distribution of the samples, with a general low mtdna diversity that may reflect a low effective population size (briggs et al., 2009). in addition, some nuclear genes were studied, since they are involved in phenotypic traits that could highlight possible differences between modern humans and neandertal. for example, a private variant of the mc1r gene was found in two neandertal remains, coding for pale skin color and red hair (laluezafox et al., 2007), representing an example of convergent evolution for adaptation to environments with low solar radiation. with the ngs approach, it was then possible to obtain the whole nuclear genome from neandertal specimens, and to find that a portion around 1-4% of the genome of the extant inhabitants of eurasia is shared with neandertals. the most parsimonious explanations for this sharing are two: i) the neandertals exchanged genes with the ancestors of all non-africans or ii) the presence of an old substructure in africa, whose traces persisted both in the neandertal lineage and in the modern human one (green et al., 2010). recently, the genome of a modern human sample, found in romania and dated to 39,000-42,000 years ago, carrying morphological traits that could indicate admixture with neandertals, was determined. 6-9% of the genome of this individual showed neandertal ancestry compatible with an admixture occurred four to six generation back (fu et al., 2015). a new human species was identified in 2010 thanks to adna analysis: samples from the denisova cave, in southern siberia, dated to 50,300-62,200 years ago, showed a genetic variation that falls outside the range of both modern humans and neandertals. according to the mitochondrial genome, the denisova repre 117 fig. 3 schematic reconstruction of the possible gene flow events occurred between human lineages during late pleistocene (data from prüfer et al., 2014). ancient dna studies sents a human lineage that diverged about 1 million years ago from the branch that carried to h. sapiens and neandertal (krause et al., 2010b). data from the nuclear genome showed that probably denisovans contributed to the 4-6% of the genome of present-day melanesians (reich et al., 2010). the phylogenetic tree reconstructed using nuclear data place denisovans as sister group of neandertals. the difference between the phylogenesis obtained from mitochondrial and nuclear genomes can be explained considering that the mtdna is only maternally inherited, while the nuclear genome carries information from both parents. for this reason the two genetic markers can tell different population histories. the nuclear data from human forms closely related to modern humans represent an important informative source also for understanding which genetic variants characterize the homo sapiens lineage becoming fixed after its separation from the ancestors of neandertals and denisovans. genes that showed derived variants only in the modern humans are involved with brain function and nervous system development, as well as the physiology of skin and eye and dental morphology (meyer et al., 2012; prufer et al., 2014). thanks to the reconstructed ancient genomes, it was possible to recognize several gene flow events, with general low extent or at least with low effect on the extant populations, that have involved neandertals, denisovans and emhs during their coexistence in eurasia during late pleistocene (fig. 3). the research on past human forms is still developing, since new specimens are discovered. a new protagonist of the human history provided genetic information to be added to the already complex reconstruction, representing also the most ancient sample from temperate environment that yielded endogenous dna. the sample, attributed to homo heidelbergensis according to morphology but with some neandertal-derived characteristics, was date over 300,000 years ago. the already determined mitochondrial genome showed to be closely related to the lineage of denisovans, increasing the expectation for the next nuclear data (meyer et al., 2014). adna data gave a big contribution also for understanding the more recent population history of homo sapiens, especially for europe. the presence of emhs in europe is attested since 45,000 bp and particular climatic and cultural changes characterized the population dynamics during time: last glacial maximum, mesolithic with mobile groups and neolithic transition with the appearance of a sedentary lifestyle, copper, bronze and iron ages with the emergence of complex societies. with the ngs technology, several prehistoric human genomes were sequenced, leading to a deeper understanding of such dynamics (olalde and laluezfox, 2015). the first genome to be sequenced was obtained from the the tyrolean iceman (ötzi) lived during the neolithic-copper age transition: the nuclear genomes permitted to determine some phenotypic characteristic and pathogens’ presence as well as information useful for determining the relationship of the sample with modern european, north african and middle eastern popula tions (keller et al., 2012). analyzing other ancient and modern genomes, it was highlighted that most present-day europeans derive from at least three highly differentiated populations: west european hunter-gatherers who probably contributed ancestry to all europeans, upper palaeolithic north eurasians who contributed to europeans and near easterners and early european farmers of near eastern origin with signs also of european huntergatherer ancestry (lazaridis et al., 2014). analysis on 101 ancient humans from eurasia confirmed that the bronze age was a period of big social changes. genomic data showed that large-scale population migrations and replacements occurred, and that probably they are responsible for the major parts of present-day demographic structure in both europe and asia. these migrations could also be related with the spread of indo-european languages hypothesized to be occurred during the early bronze age (allentoft et al., 2015). 5. conclusions for its huge informative power, adna represents a precious resource to support all those disciplines that have the aim to reconstruct past biological events and to use this knowledge for better understand and manage the present variability. major limits are due to different degree of dna preservation in ancient samples, but fast and continuous developing in methodologies, leading to discoveries that were unimaginable three decades ago at the beginning of this discipline, are promising to push beyond the current limitations. references adler c.j., dobney k., weyrich l.s., kaidonis j., walker a.w., haak w., bradshaw c.j., townsend g., soltysiak a., alt k.w., et al. (2013) sequencing ancient calcified dental plaque shows changes in oral microbiota with dietary shifts of the neolithic and industrial revolutions. nat. genet., 45, 450455, 455e451. allaby r.g., gutaker r., clarke a.c., pearson n., ware r., palmer s.a., kitchen j.l., and smith o. (2014) using archaeogenomic and computational approaches to unravel the history of local adaptation in crops. philosophical transactions of the royal society of london b: biological sciences, 370. allaby r.g., kistler l., gutaker r.m., ware r., kitchen j.l., smith o., and clarke a.c. (2015) archaeogenomic insights into the adaptation of plants to the human environment: pushing plant-hominin co-evolution back to the pliocene. j. hum. evol., 79, 150-157. allentoft m.e., sikora m., sjögren k-g., rasmussen s., rasmussen m., stenderup j., damgaard p.b., schroeder h., ahlström t., vinner l., et al. (2015) population genomics of bronze age eurasia. nature, 522(7555), 167-72. beja-pereira a., caramelli d., lalueza-fox c., vernesi c., ferrand n., casoli a., goyache f., royo l.j., 118 vai s. et al. conti s., lari m., et al. (2006) the origin of european cattle: evidence from modern and ancient dna. proc. natl. acad. sci. usa, 103, 8113-8118. bos k.i., schuenemann v.j., golding g.b., burbano h.a., waglechner n., coombes b.k., mcphee j.b., dewitte s.n., meyer m., schmedes s., et al. (2011) a draft genome of yersinia pestis from victims of the black death. nature, 478, 506-510. briggs a.w., stenzel u., johnson p.l., green r.e., kelso j., prufer k., meyer m., krause j., ronan m.t., lachmann m., et al. (2007) patterns of damage in genomic dna sequences from a neandertal. proc. natl. acad. sci. usa, 104, 1461614621. briggs a.w., good j.m., green, r.e. krause, j., maricic t., stenzel u., lalueza-fox c., rudan p., brajkovic d., kucan z., et al. (2009) targeted retrieval and analysis of five neandertal mtdna genomes. science, 325, 318-321. briggs a., heyn p. (2012) preparation of nextgeneration sequencing libraries from damaged dna. in: b. shapiro and m. hofreiter eds., ancient dna methods and protocols, (humana press). brotherton p., endicott p., sanchez j.j., beaumont m., barnett r., austin j., and cooper, a. (2007) novel high-resolution characterization of ancient dna reveals c > u-type base modification events as the sole cause of post mortem miscoding lesions. nucleic acids res., 35, 5717-5728. caramelli d., lalueza-fox c., vernesi c., lari m., casoli a., mallegni f., chiarelli b., dupanloup i., bertranpetit j., barbujani g., et al. (2003) evidence for a genetic discontinuity between neandertals and 24,000-year-old anatomically modern europeans. proc. natl. acad. sci. usa, 100, 6593-6597. carpenter m.l., buenrostro j.d., valdiosera c., schroeder h., allentoft m.e., sikora m., rasmussen m., gravel s., guillen s., nekhrizov g., et al. (2013) pulling out the 1%: whole-genome capture for the targeted enrichment of ancient dna sequencing libraries. am. j. hum. genet., 93, 852-864. cooper a. and poinar h.n. (2000) ancient dna: do it right or not at all. science, 289(5482), 1139. da fonseca r.r., smith b.d., wales n., cappellini e., skoglund p., fumagalli m., samaniego j.a., carøe c., ávila-arcos m.c., hufnagel d.e., et al. (2015) the origin and evolution of maize in the southwestern united states. nature, plants 1, 14003. der sarkissian c., ermini l., jonsson h., alekseev a.n., crubezy e., shapiro b., and orlando l. (2014) shotgun microbial profiling of fossil remains. mol. ecol., 23, 1780-1798. fu q., mittnik a., johnson p.l., bos k., lari m., bollongino r., sun c., giemsch l., schmitz r., burger j., et al. (2013) a revised timescale for human evolution based on ancient mitochondrial genomes. curr. biol., 23, 553-559. fu q., hajdinjak m., moldovan o.t., constantin s., mallick s., skoglund p., patterson n., rohland n., lazaridis i., nickel b., et al. (2015) an early modern human from romania with a recent neanderthal ancestor. nature, 524, 216-219. fulton t. and stiller m. (2012) pcr amplification, cloning, and sequencing of ancient dna. in: b. shapiro and m. hofreiter eds., ancient dna methods and protocols, (humana press). ginolhac a., rasmussen m., gilbert m.t., willerslev e., orlando l. (2011) mapdamage: testing for damage patterns in ancient dna sequences. bioinformatics, 27, 2153-2155. green r.e., malaspinas a.s., krause j., briggs a.w., johnson p.l., uhler c., meyer m., good j.m., maricic t., stenzel u., et al. (2008) a complete neandertal mitochondrial genome sequence determined by high-throughput sequencing. cell., 134, 416-426. green r.e., krause j., briggs a.w., maricic t., stenzel u., kircher m., patterson n., li h., zhai w., fritz m.h., et al. (2010) a draft sequence of the neandertal genome. science, 328, 710-722. higuchi r., bowman b., freiberger m., ryder o., wilson a. (1984) dna sequences from the quagga, an extinct member of the horse family. nature, 312, 282-284. jonsson h., schubert m., seguin-orlando a., ginolhac a., petersen l., fumagalli m., albrechtsen a., petersen b., korneliussen t.s., vilstrup j.t., et al. (2014) speciation with gene flow in equids despite extensive chromosomal plasticity. proc. natl. acad. sci. usa, 111, 18655-18660. keller a., graefen a., ball m., matzas m., boisguerin v., maixner f., leidinger p., backes c., khairat r., forster m, et al. (2012) new insights into the tyrolean iceman's origin and phenotype as inferred by whole-genome sequencing. nat. comm. 3 (698). kircher m. (2012) analysis of high-throughput ancient dna sequencing data. methods mol. biol. 840, 197-228. knapp m., lalueaza-fox c., hofreiter m. (2015) reinventing ancient human dna. investig genet 6:4. krause j., briggs a.w., kircher m., maricic t., zwyns n., derevianko a., paabo s. (2010a) a complete mtdna genome of an early modern human from kostenki, russia. curr. biol. 20, 231-236. krause j., fu q., good j.m., viola b., shunkov m.v., derevianko a.p., paabo, s. (2010b) the complete mitochondrial dna genome of an unknown hominin from southern siberia. nature, 464, 894-897. krings m., capelli c., tschentscher f., geisert h., meyer s., von haeseler a., grossschmidt k., possnert g., paunovic m., and paabo s. (2000) a view of neandertal genetic diversity. nat genet 26, 144-146. lalueza-fox c., rompler h., caramelli d., staubert c., catalano g., hughes d., rohland n., pilli e., longo l., condemi s., et al. (2007) a melanocortin 1 receptor allele suggests varying pigmentation among neanderthals. science, 318, 1453-1455. lari m., rizzi e., mona s., corti g., catalano g., chen k., vernesi c., larson g., boscato p., de bellis g., et al. (2011) the complete mitochondrial genome of an 11,450-year-old aurochsen (bos primigenius) from central italy. bmc evol. biol., 11, 32. larson g., albarella u., dobney k., rowley-conwy p., 119 ancient dna studies schibler j., tresset a., vigne j.d., edwards c.j., schlumbaum a., dinu a., et al. (2007) ancient dna, pig domestication, and the spread of the neolithic into europe. proc. natl. acad. sci. usa, 104, 15276-15281. lazaridis i., patterson n., mittnik a., renaud g., mallick s., kirsanow k., sudmant p.h., schraiber j.g., castellano s., lipson m. et al. (2014) ancient human genomes suggest three ancestral populations for present-day europeans. nature, 513, 409 -413. maricic t., whitten m., paabo, s. (2010) multiplexed dna sequence capture of mitochondrial genomes using pcr products. plos one, 5, e14004. meyer m., kircher m., gansauge m.t., li h., racimo f., mallick s., schraiber j.g., jay f., prufer k., de filippo c., et al. (2012) a high-coverage genome sequence from an archaic denisovan individual. science, 338, 222-226. meyer m., fu q., aximu-petri a., glocke i., nickel b., arsuaga j.l., martinez i., gracia a., de castro j.m., carbonell e., et al. (2014) a mitochondrial genome sequence of a hominin from sima de los huesos. nature, 505, 403-406. miller w., drautz d.i., ratan a., pusey b., qi j., lesk a.m., tomsho l.p., packard m.d., zhao f., sher a., et al. (2008) sequencing the nuclear genome of the extinct woolly mammoth. nature, 456, 387390. mona s., catalano g., lari m., larson g., boscato p., casoli a., sineo l., di patti c., pecchioli e., caramelli d., et al. (2010) population dynamic of the extinct european aurochs: genetic evidence of a north-south differentiation pattern and no evidence of post-glacial expansion. bmc evol. biol., 10, 83. olalde i., lalueza-fox c. (2015) modern humans’ paleogenomics and the new evidences on the european prehistory. star, 1(1). orlando l., ginolhac a., zhang g., froese d., albrechtsen a., stiller m., schubert m., cappellini e., petersen b., moltke i., et al. (2013) recalibrating equus evolution using the genome sequence of an early middle pleistocene horse. nature, 499, 7478. ottoni c., flink l.g., evin a., georg c., de cupere b., van neer w., bartosiewicz l., linderholm a., barnett r., peters j., et al. (2013) pig domestication and human-mediated dispersal in western eurasia revealed through ancient dna and geometric morphometrics. mol. biol. evol., 30, 824-832. pääbo s. (1985). molecular-cloning of ancient egyptian mummy dna. nature 314, 644-645. palmer s.a., clapham a.j., rose p., freitas f.o., owen b.d., beresford-jones d., moore j.d., kitchen j.l., allaby, r.g. (2012) archaeogenomic evidence of punctuated genome evolution in gossypium. mol. biol. evol., 29, 2031-2038. pansu j., giguet-covex c., ficetola g.f., gielly l., boyer f., zinger l., arnaud f., poulenard j., taberlet p., choler p. (2015) reconstructing long-term human impacts on plant communities: an ecological approach based on lake sediment dna. mol. ecol., 24(7), 1485-98. pilli e., modi a., serpico c., achilli a., lancioni h., lippi b., bertoldi f., gelichi s., lari m., caramelli, d. (2013) monitoring dna contamination in handled vs. directly excavated ancient human skeletal remains. plos one, 8, e52524. prüfer k., racimo f., patterson n., jay f., sankararaman s., sawyer s., heinze a., renaud g., sudmant, p.h. de filippo c., et al. (2014) the complete genome sequence of a neanderthal from the altai mountains. nature, 505, 43-49. reich d., green r.e., kircher m., krause j., patterson n., durand e.y., viola b., briggs a.w., stenzel u., johnson p.l., et al. (2010) genetic history of an archaic hominin group from denisova cave in siberia. nature, 468, 1053-1060. renaud g., slon v., duggan a.t., kelso j. (2015) schmutzi: estimation of contamination and endogenous mitochondrial consensus calling for ancient dna. genome biol., 16, 224. scheu a., powell a., bollongino r., vigne j.d., tresset a., cakirlar c., benecke n., burger j. (2015) the genetic prehistory of domesticated cattle from their origin to the spread across europe. bmc genet., 16, 54. schubert m., ermini l., der sarkissian c., jonsson h., ginolhac a., schaefer r., martin m.d., fernandez r., kircher m., mccue m., et al. (2014) characterization of ancient and modern genomes by snp detection and phylogenomic and metagenomic analysis using paleomix. nat. protoc., 9, 10561082. schuenemann v.j., bos k., dewitte s., schmedes s., jamieson j., mittnik a., forrest s., coombes b.k., wood j.w., earn d.j., et al. (2011) targeted enrichment of ancient pathogens yielding the ppcp1 plasmid of yersinia pestis from victims of the black death. proc. natl. acad. sci. usa, 108, e746-752. schuenemann v.j., singh p., mendum t.a., krausekyora b., jager g., bos k.i., herbig a., economou c., benjak a., busso p., et al. (2013) genomewide comparison of medieval and modern mycobacterium leprae. science, 341, 179-183. smith o., momber g., bates r., garwood p., fitch s., pallen m., gaffney v., allaby r.g. (2015) archaeology. sedimentary dna from a submerged site reveals wheat in the british isles 8000 years ago. science, 347(6225), 998-1001. vai s., vilaca s.t., romandini m., benazzo a., visentini p., modolo m., bertolini m., macqueen p., austin j., cooper a., et al. (2015) the biarzo case in northern italy: is the temporal dynamic of swine mitochondrial dna lineages in europe related to domestication? sci. rep., 5, 16514. warinner c., rodrigues j.f., vyas r., trachsel c., shved n., grossmann j., radini a., hancock y., tito r.y., fiddyment s., et al. (2014) pathogens and host immunity in the ancient human oral cavity. nat. genet., 46, 336-344. weyrich l.a., dobney k., cooper a. (2015) ancient dna analysis of dental calculus. j. hum. evol. 79, 119-24. willerslev e., hansen a.j., binladen j., brand t.b., gil 120 vai s. et al. bert m.t.p., shapiro b., bunce m., wiuf c., gilichinsky d.a., cooper a. (2003) diverse plant and animal genetic records from holocene and pleistocene sediments. science, 300, 791-795. wood j.r., wilmshurst j.m., wagstaff s.j., worthy t.h., rawlence n.j., cooper a. (2012) highresolution coproecology: using coprolites to reconstruct the habits and habitats of new zealand’s extinct upland moa (megalapteryx didinus). plos one, 7(6), e40025. ms. received: december 1, 2015 final text received: january 29, 2016 121 ancient dna studies 122 << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /none /binding /left /calgrayprofile (dot gain 20%) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /error /compatibilitylevel 1.4 /compressobjects /tags /compresspages true /convertimagestoindexed true /passthroughjpegimages true /createjobticket false /defaultrenderingintent /default /detectblends true /detectcurves 0.0000 /colorconversionstrategy /cmyk /dothumbnails false /embedallfonts true /embedopentype false /parseiccprofilesincomments true /embedjoboptions true /dscreportinglevel 0 /emitdscwarnings false /endpage -1 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/hrv (za stvaranje adobe pdf dokumenata najpogodnijih za visokokvalitetni ispis prije tiskanja koristite ove postavke. stvoreni pdf dokumenti mogu se otvoriti acrobat i adobe reader 5.0 i kasnijim verzijama.) /hun 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can be opened with acrobat and adobe reader 5.0 and later.) >> /namespace [ (adobe) (common) (1.0) ] /othernamespaces [ << /asreaderspreads false /cropimagestoframes true /errorcontrol /warnandcontinue /flattenerignorespreadoverrides false /includeguidesgrids false /includenonprinting false /includeslug false /namespace [ (adobe) (indesign) (4.0) ] /omitplacedbitmaps false /omitplacedeps false /omitplacedpdf false /simulateoverprint /legacy >> << /addbleedmarks false /addcolorbars false /addcropmarks false /addpageinfo false /addregmarks false /convertcolors /converttocmyk /destinationprofilename () /destinationprofileselector /documentcmyk /downsample16bitimages true /flattenerpreset << /presetselector /mediumresolution >> /formelements false /generatestructure false /includebookmarks false /includehyperlinks false /includeinteractive false /includelayers false /includeprofiles false /multimediahandling /useobjectsettings /namespace [ (adobe) (creativesuite) (2.0) ] /pdfxoutputintentprofileselector /documentcmyk /preserveediting true /untaggedcmykhandling /leaveuntagged /untaggedrgbhandling /usedocumentprofile /usedocumentbleed false >> ] >> setdistillerparams << /hwresolution [2400 2400] /pagesize [612.000 792.000] >> setpagedevice available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 83 87 did elephants meet humans along the devil’s path ? a preliminary report maria rita palombo 1, adolfo panarello 2, paolo mietto 3 1 igag-cnr, c/o dipartimento di scienze della terra, università di roma “sapienza”, roma, italy 2 dipartimento di scienze umane, sociali e della salute, università studi cassino e lazio meridionale, cassino (fr), italy 3 dipartimento di geoscienze, università degli studi di padova, padova, italy corresponding author: m.r. palombo <mariarita.palombo@uniroma1.it> abstract: this research aims to give notice of and provide preliminary information on some elephant footprints recently identified at foresta ichnological site (tora-piccilli, caserta, central italy). the elephant-footprint area was previously poorly investigated because partially affected by anthropic modifications during historical times. the footprints, ascribed to the proboscipeda panfamilia ichospecies, were left by a young strait-tusked elephant, passing the top of the slope formed during the deposition of the roccamonfina brown leucitic tuff (blt), close to the renowned prehistorical devil’s path. the foresta elephant footprints are the unique conceivably belonging to palaeoloxodon recorded in italy and the first elephant tracks reported from the continental italian territory. keywords: palaeoloxodon, footprints, foresta ichnosite, early mis 10, central italy 1. introduction since the time of the first announcement to the scientific community of the identification of the so-called “ciampate del diavolo” as prehistoric hominin tracks and track-ways (mietto et al., 2003), the notoriety of the ichno-site, located on the northeastern slope of the roccamonfina volcano (n41°19.954’ e14°01.488’), has been constantly increasing not only due to its proved antiquity (349-350±3 ka, panarello et al., 2017a), but also because of the unique and rich information the human footprints may provide with regard to the physical characteristic and behaviour of italian hominins (likely homo heidelbergensis) at the beginning of a middle pleistocene glacial phase (early mis 10) (avanzini et al., 2008; panarello et al., 2017 a, b). although few mammal tracks were noted on the surface of the roccamonfina brown leucitic tuff (blt) recording the hominin tracks, initially the research activity at the site mainly focused on hominin footprints and their depositional context. in the last couple of years, archaeological and palaeontological investigations, mainly finalised to investigate the environmental context, started and are still in progress. in particular, an attentive analysis of the palaeosurface led to the detection of a few middle-sized artiodactyl and horse tracks (panarello et al., 2017b). this research aims to give notice of and provide preliminary information on some elephant footprints detected near and roughly along the prehistoric path during a new survey on an area previously poorly investigated because affected, during the last century, by anthropic modifications. 2. materials and method the studied material consists of some isolated impressions (manus and pes), preserved as concave epireliefs, organised in a quite narrow, short track-way developed nearly along the devil’s path. herein we briefly describ only the best preserved footprints where some anatomical details (i.e. toe/nail impressions) are still more or less discernible. different length and width measurements were taken considering, if possible, the outline and the edge of the manus/pes impression, and the extent of sediment deformations (fig. 1). the height at the shoulder of the trace-maker has been estimated following lee & moss (1995), the possible age range has been inferred on the basis of the growth curve (height for age) of extant bush african elephants corrected according to data available for straighttusked elephants (marano & palombo, 2013; larramendi et al, 2017). estimate of body mass was derived by the manus circumference and height at the shoulder, following the method proposed by palombo & giovinazzo (2005, pag. 258, table1). the area recording the elephant fossil footprints was georeferenced with a garmin etrex 10 detector (accuracy ±3 m) and photographed through sony nex6 camera with sony 16-50 lens. a detailed 3d model was then created by processing the pictures with agisoft photoscan pro and kitware paraview software following the procedures proposed by mallison & wings (2014) and belvedere et al. (2013). https://doi.org/10.26382/aiqua.2018.aiquaconference 84 palombo m.r. et al. fig. 1 foresta (roccamonfina volcano): fossil proboscidean track area: a) general photo view with notations; b) detail photo of the footprint m1-l; c) detail photo of the footprint m2-r; d) contour map (interval: 1 mm); e) contoured depth map. 85 3. systematic ichnology ichnogenus proboscipeda panin & avram, 1962 (type ichnospecies proboscipeda enigmatica panin & avram, 1962) proboscipeda panfamilia mc neil, hills, tolman & kooyman, 2007 (fig. 1) the elephant tracks here described consist at least of four well identifiable footprints (m1-l, m2-r, p1 and p2, fig. 1a), nearly rounded to oval in shape, preserved as convex hyporeliefs, bordered by more or less inflated and prominent pressure pads (push up). the footprints are arranged in a short track-way along which some other impressions are present, potentially left by the same trace-maker. the footprints are present in an area modified by anthropic activity in historical time. this which further complicates the detection and identification of the tracks on the palaeosurface, which is challenging, “due to the characteristics of the pyroclastic flow they are impressed on, and the alteration undergone by the top of the volcanoclastic deposit during its prolonged exposure to weathering agents” (panarello et al., 2017b, pag. 145). accordingly, the actual nature of some impressions can only be hypothesised due to their poor preservation status. the best preserved footprints (m1-l, m2-r) (fig. 2e, f) show an oval outline, with the width being the greatest dimension, and evident four toe imprints at the anterior end of the manus impression as a result of the peculiar dynamic of cushion deformation, and the support offered to the limb rotational movement during the limb and foot rotational movements (hutchinson et al., 2006; 2011). interesting to note the sharp edges of the toe impressions that indicate the presence of nails, suggesting that the tracks were left by a young individual because nails are usually worn down in adult elephants and not always shown on their footprints. in both footprints the deepest zone corresponds to the front part, which is opposite of dip, following the typical rotation during the event foot on foot off. the lateral border of the m2-r footprint shows a quite typical “dragging” imprint, likely left during the foot off event. only the medial margin is preserved of the right manus footprint m0-r (fig.1) (measured length =314,76 mm). the impression, indeed, was destroyed in historical time to create a small quadrangular area for placing baskets at the southern verge of the prehistoric path, which was used as a shortcut up to recent time (panarello et al., 2017a). an intriguing, abnormally long track (t and ?, red in fig. 1a) may suggest a hint foot (pes) dragging, although it actually may result from the combination of two different imprints: an imprint left by the trunk digging the surface at the anterior end (t) and an impression of a dragging foot (?). further analysis is needed to support or reject this hypothesis. the estimated dimensions of m1-l and m2-r footprints (length x width = 248.05x277.17 mm and 329.43x334.82 mm respectively) support the hypothesis of a young elephant trace-maker. the inferred age, about 4-9 years if female and 5-8 years if male, suggested it may have had a height at the shoulder in flesh not exceeding 1.9 m. estimates of body mass of about 2600 kg, obtained using as variable the height at the shoulder, and 2350 kg, by using the circumference pad inferred from the dimensions of m1-l, are roughly consistent with the body mass range of adult forest african elephants (loxodonta cyclotis), whose height only exceptionally reaches 2.2 m (e.g. haynes, 1991; morgan & lee, 2003; larramendi, 2016). the estimate of body mass based on the inferred pad circumference of m2-t, affected by the toe dragging, results overestimated (about 4250 kg). the value obtained largely exceeds the average value of loxodonta africana males of a comparable stature, and even that of bush elephant adult females. 4. discussion and conclusion fossil proboscidean tracks and track-ways (ichnogenus proboscipeda), which have been reported from all over the world (except for oceania) although not so frequently, (e.g. lucas et al., 2007 and references therein; matsukawa & shibata, 2015; hunt & lucas, 2016; neto-de-carvalho et al., 2016; pillola & zoboli, 2017; retallack et al., 2018), may provide interesting information about the consistency of the proboscidean fossil record, animal behaviour, locomotor characteristics and social structure (e.g. bibi et al., 2012) also in areas where fossil bones have never been reported. proboscidean footprints, which are known from sites ranging in age from the late eocene (proboscipeda enigmatica and cf. proboscipeda isp., from iran; abbassi et al., 2018) to the latest pleistocene, are rarely associated with human footprints (kim et al., 2010). all the fossil and extant proboscidean tracks are included in the ichnogenus proboscipeda. the ichnogenus was proposed for proboscidean tracks from the miocene of romania (panin & avram, 1962) and, according to the diagnosis, it includes footprints described as large (11.0 62.0 cm in diameter), ovoidal to circular depressions, sometimes showing digit impressions, and, quite frequently, repeated overstepping of manus and pes footprints in trackways. the ichnogenus includes two inchnospecies, proboscipeda enigmatica and proboscipeda panfamilia. p. enigmatica, erected by panin & avram (1962) for miocene proboscidean tracks (likely deinotheres) found in romania, mainly refer to primitive proboscideans, while tfootprints of elephants belonging to the loxodontini and elephantini tribe (sensu shoshani & tassy, 2005) are generally referred to the p. panfamilia ichnospecies, erected by mcneil et al. (2007) for pleistocene mammouth tracks found at st. mary reservoir (alberta, canada). these tracks have been described as averagely larger and more circular than p. enigmatica, usually showing a bilateral symmetry, with toe impressions often visible, though the number of impression could not match the actual number of toes in the foot. in particular, “a short toe impressions at the anterior end is unique to mammuthus and extant proboscideans” (mcneil et al., 2007, pag. 210). toe impressions, however, were reported in a number of footprints left by the endemic japanese species palaeoloxodon naumanni (nojiri-ko fossil footprint research group, elephant footprints at foresta ichnosite 1992), and in palaeoloxodon antiquus tracks (neto-decarvalho et al., 2016). the large footprints recently detected at foresta ichnosite, and herein preliminarily described, can be confidently assigned to the p. panfamilia ichnospecies, as indicated by their overall morphology and size. it is however difficult to identify the species to which the trace-maker belongs, similarly to most animal tracks. the assignment of proboscidean footprints to a proboscipeda ichnospecies and/or to a specific trace-maker is mostly based on the age of the deposits (as regards to the distinction between p. enigmatica and p. panfamilia), and on the known occurrences of fossil bones in the depositional context or in coeval sediments of the region, rather than on the size and morphology of footprints. based on some literature data (i.e. mcneil et al., 2007), however, it would seem reasonable to suppose that the proportion between length and width and the presence vs absence of toe impressions, as well as the possible number of nails if visible, may have some taxonomic relevance and facilitate the identification of the trace-maker. it is worth noting, however, that “the morphology of an elephant footprint can change depending on the type of substrate the maker was walking on”, and “the impression of toes ranged from absent to present depending on the type of substrate, even when made by the same elephant” (pasenko, 2017, pag. 224). accordingly, “the presence or absence of digit impressions should not be used solely to assign a proboscidean footprint to an ichnotaxonomic label … this is most likely a result of differences in substrate rather than specific distinction” (pasenko, 2017, pag. 224). in addition, the foot shapes of elephantinae representatives (elephas, loxodonta, palaeoloxodon, mammuthus) shows a basically similar structure. the differences in foot proportions and general shape among species are not relevant, particularly when the intraspecific variability (e.g. individual variation, ontogenetic growth, gender) are considered. random factors (such as the nature of the substrate, topography, and locomotion dynamics), may, however, affect size, depth and shape of any footprint, making the identification of the trace-maker problematic, especially when the tracks are few and they do not belong to a track-way. there is little doubt, however, that, proboscidean footprints could provide useful information especially when fossil remains are absent. in the case of foresta footprints, for example, they provide evidence for the presence of a proboscideans herd. some support to the hypothetical identification of the trace-maker of foresta footprints could be provided by the fact that during the middle pleistocene straighttusked elephant populations are widely recorded in a number of sites from northern to southern italy. p. antiquus was the dominant species in various local faunal assemblages (lfas), while mammuthus is recorded from a very few localities (palombo & ferretti, 2005). in southern latium, straight-tusked elephant remains are reported from most of the lafs where the presence of lower palaeolithic hominins (homo heidelbergensis) is attested by artifacts and fossil remains. the hypothesis that the elephant trace-maker at foresta was a young p. antiquus, is, therefore, the most plausible, but not demonstrable. p. panfamilia tracks attributable to palaeoloxodon have been reported to date only from the iberian peninsula (portugal, neto-de-carvalho, 2009, 2011; neto-decarvalho et al., 2016; spain, manzanares valley, panera et al., 2014) and in the eastern mediterranean islands (rhodes and cyprus, milàn et al. 2007, 2015). the tracks mostly belong to adult individuals, even if those from rhodes and cyprus, left by endemic smallsized elephants, show dimensions roughly comparable with those of foresta. mammuthus footprints are nearly unknown in the european middle pleistocene. in italy, some tracks likely attributable to the endemic species mammuthus lamarmorai, have been recently described from late pleistocene aeolian deposits in sardinia (pillola & zoboli, 2017). assuming as true that the foresta footprints can be attributed to a young straight-tusked elephant, negotiating the top of the slope formed during the deposition of the roccamonfina brown leucitic tuff (blt) close to the renowned prehistorical devil’s path, they would be the only tracks of palaeoloxodon recorded in italy and the first elephant tracks reported from the continental italian territory. the results present herein have to be regarded as preliminary. the detailed investigation of the imprinted volcanic surface currently in progress at foresta may provide new data and answer a number of still open questions about the mammalian species walking along and in vicinity of the devil’s prehistoric path. references abbassi n., alinasiri s., lucas s.g. (2017) new localities of late eocene vertebrate footprints from the tarom mountains, northwestern iran. historical biology, 29(7), 987-1006. avanzini m., mietto p., panarello a., de angelis m., rolandi g. (2008) the devil’s trails: middle pleistocene human footprints preserved in a volcanoclastic deposit of southern italy. ichnos, 15, 179-189. belvedere m., jalil n.-e., breda a., gattolin g., bourget h., khaldoune f., dyke g.j. (2013). vertebrate footprints from the kem kem beds (morocco): a novel ichnological approach to faunal reconstruction. palaeogeography, palaeoclimatology, palaeoecology, 383/384, 52-58. bibi f., kraatz b., craig n., beech m., schuster m., hill a. (2012) early evidence for complex social structure in proboscidea from a late miocene trackway site in the united arab emirates. biology letters 8, 670-673 kim c.b., kim j.y., kim k.s., lim h.s. (2010) new age constraints for hominid footprints found on jeju island, south korea. journal archaeological science, 37(12), 3338-3343. haynes g. (1991) mammoths, mastodonts, and elephants: biology, behavior and the fossil record. cambridge university press, cambridge, uk, pp. 413. hunt a.p., lucas s.g. (2016) vertebrate trace fossils 86 palombo m.r. et al. from new mexico and their significance. new mex mus nat hist sci bull, 64, 9-40. larramendi a. (2015) shoulder height, body mass, and shape of proboscideans. acta palaeontologica polonica, 61(3), 537-574. larramendi a., palombo m.r., marano f. (2017) reconstructing the life appearance of a pleistocene giant: size, shape, sexual dimorphism and ontogeny of palaeoloxodon antiquus (proboscidea: elephantidae) from neumark-nord 1 (germany). boll. soc. pal. it., 56(3), 299-317. lee p.c., moss c.j. (1995) statural growth in knownage african elephants (loxodonta africana). j. zool., lond. 236, 29-41. lucas s.g., spielmann j.a., lockley m.g. (2007) cenozoic vertebrate tracks and traces. new mexico museum of natural history and science bulletin, 42, 241-249. mallison h., wings o. (2014). photogrammetry in paleontology a practical guide. j. paleont. tech., 12, 1-31. marano f., palombo m.r. (2013) population structure in straight-tusked elephants: a case study from neumark nord 1 (late middle pleistocene?, sachsen-anhalt, germany). boll. soc. paleont. it., 52 (3), 207-18. matsukawa m., shibata k. (2015) review of japanese cenozoic (miocene-modern) vertebrate tracks. ichnos, 22(3-4), 261-290. mcneil p., hills l.v., tolman s.m., kooyman b. (2007) significance of latest pleistocene tracks, trackways, and trample grounds from southern alberta, canada. in lucas s.g., spielmann j.a., lockley m.g. (eds): cenozoic vertebrate tracks and traces. new mexico mus. nat. hist, sc. bull., 42, 209-223. mietto p., avanzini m., rolandi g. (2003) human footprints in pleistocene volcanic ash. nature, 422, 133. milàn j., theodorou g., loope d. b., panayides i., clemmesnsen l. b., gkioni m. (2015) vertebrate tracks in late pleistocene-early holocene (?) carbonate aeolianites, paphos, cyprus. ann. soc. geol. poloniae, 85, 507-514. milàn j., bromley r.g., titschack j., theodorou g. (2007) a diverse vertebrate ichnofauna from the quaternary eolian oolite, rhodes, greece. sediment-organism interactions: a multifaceted ichnology, sepm special publ., 88, 333-343. morgan b.j., leep.c. (2003) forest elephant (loxodonta africana cyclotis) stature in the reserve de faune du petit loango, gabon. j. zool., 259, 337-344. neto-de-carvalho c. (2009) vertebrate tracksites from the mid-late pleistocene eolianites of portugal: the first record of elephant tracks in europe. geol. quarterly, 53(4), 407-414. neto-de-carvalho c.n., figueiredo s., belo, j. (2016) vertebrate tracks and trackways from the pleistocene eolianites of sw portugal. comunicaçõe geológicas, 103, 101-116. nojiri-ko fossil footprint research group (1992) footprint fossils of naumann’s elephants discovered from the upper pleistocene nojiri-ko formation: chikyou kagaku (tokyo), 46, 385-404 (in japanese, english abstract). palombo m.r., ferretti m.p. (2005) elephant fossil record from italy: knowledge, problems, and perspectives. quaternary international, 126, 107-136. palombo m.r., giovinazzo c. (2005) elephas falconeri from spinagallo cave (south-eastern sicily, hyblean plateau, siracusa): a preliminary report on brain to body weight comparison. societat d'història natural de les balears, 12, 255-264. panarello a., santello l., farinaro g., bennett m. r., mietto p. (2017a) walking along the oldest human fossil pathway (roccamonfina volcano, central italy)? j. archaeol. sc. reports, 13, 476-490. panarello a, palombo m.r., biddittu i., mietto p. (2017b) fifthteen years along the “devils2 trails”: new data and perspectives. alpine and mediterranean quaternary, 30 (2), 137-154. panera j, rubio-jara s, yravedra j, blain ha, sesé c, pérez-gonzález a. (2014) manzanares valley (madrid, spain): a good country for proboscideans and neanderthals. quaternary international, 326, 329-343. panin n., avram e. (1962) noi urme de vertebrate in miocenul subcarpatilor rominesti (nouvelles empreintes de vertèbres dans le miocène de la zone subcarpathique roumaine). studii si cercetari de geologie, 7, 455-484. pasenko m.r. (2017) quantitative and qualitative data of footprints produced by asian (elephas maximus) and african (loxodonta africana) elephants and with a discussion of significance towards fossilized proboscidean footprints. quaternary international, 443, 221-227. pillola g.l., zoboli d. (2017) dwarf mammoth footprints from the pleistocene of gonnesa (southwestern sardinia, italy). boll. soc. paleont. it., 56(1), 57-64. remeika p. (2006) fossil footprints of anza-borrego. in: jefferson g.t., lindsay l. (eds.), fossil treasures of the anza-borrego desert. sunbelt publication, san diego, 311-327. retallack g.j., martin j.e., broz a.p., breithaupt b.h., matthews n.a., walton d.p. (2018) late pleistocene mammoth trackway from fossil lake, oregon. palaeogeography, palaeoclimatology, palaeoecology, 496, 192-204. shoshani j., tassy p. (2005) advances in proboscidean taxonomy & classification, anatomy & physiology, and ecology & behavior. quaternary international, 126, 5-20. 87 elephant footprints at foresta ichnosite ms. received: may 2, 2018 final text received: may 16, 2018 https://www.sciencedirect.com/science/journal/00310182/496/supp/c 88 amq30(1) 2 toniato 2.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 30 (1), 2017, 11 23 revised bison skull from the salita di oriolo quarry near faenza, “sabbie gialle”, pleistocene, northern apennines giulia toniato 1, stefano marabini 2, benedetto sala 1, gian battista vai 2 1 museo di paleontologia e preistoria, università di ferrara, italy 2 museo geologico giovanni capellini, dip bigea, alma mater studiorum, università di bologna, italy corresponding author: s. marabini <stemarabini@libero.it> abstract: improvements in the knowledge of middle to late pleistocene terrestrial stratigraphy in the romagna and emilia apennine foothills and new studies on the underlying marine yellow sand deposits have led to reconsider the taxonomy of a fossil bison neurocranium found in the “sabbie gialle” layers of the salita di oriolo quarry, near faenza in the late 1980s. the skull fragment, erroneously associated in the past with a southern mammoth (mammuthus meridionalis) skull found in the same large quarry some distance away from it, was identified as bison aff. schoetensacki. reanalysis of morphometric traits and comparison with other fossil material questions this interpretation and suggests a re-positioning of the oriolo bison among the primitive bison (eobison) forms of the late villafranchian, before the end of the early pleistocene. to test the consistency of the new assignment, an updated review of all available regional and local stratigraphic data is here presented. original and new field data are focused in view of a more precise dating of the top layers of the marine blue clay (argille azzurre) fm underlying the “sabbie gialle” (yellow sand) and of a closer correlation of the different cyclic sand bodies. the outcome is that the bison skull was dug about 25 m below the mammuthus meridionalis, and both mammals were buried into different depositional cycles separated by unconformities. while the mammoth remain was emplaced sometimes after the matuyama/brunhes reversal and may therefore be assigned to the middle pleistocene, the bison is definitely older, and might actually be correlated with a late early pleistocene sicilian age not far from the jaramillo subchron, which is the present target of field research. keywords: late lower and middle pleistocene, marine biostratigraphy, large mammals, cyclostratigraphy, magnetostratigraphy. 1. introduction the classic lithostratigraphy of the plio-pleistocene foothills of the northern apennines, dating back to leonardo da vinci (1452-1519), jacopo bartolomeo beccari (1682-1766), giambattista brocchi (1772-1826), and giuseppe scarabelli (1820-1905) to whom we owe the traditional marine formation names of argille azzurre (blue clay),” sabbie gialle” (yellow sand), and the recognition of terraced alluvial deposits (see also selli, 1949a, 1949b, 1962; ruggieri, 1944; ruggieri & selli, 1949-1950, azzaroli & berzi, 1970, vai, 1988), has been articulated and improved in the last century with the addition of a sequential approach, which resulted crucial in understanding the marginal environment (“sabbie gialle”) and even more the continental (terraced) deposits. in spite of this, some problems remain unresolved. this paper proposes an updated taxonomic and chronological position of the bison skull from the “sabbie gialle” of the salita di oriolo quarry (masini et al., 1995), and contributes to improving the stratigraphic framework of the imola sands (amorosi et al., 1998a, 1998b), as well as discussing some results recently published in a paper by muttoni et al. (2011). 2. previous studies and stratigraphy of “sabbie gialle” in the imola-faenza foothills an increasing use of a sequential approach (ricci lucchi, 1982; vai 1984, 1988; marabini et al., 1987a, 1987b; farabegoli, 1985; farabegoli & onorevoli, 1991; farabegoli et al., 1999; marabini & vai, 1995; marabini et al., 1996; amorosi et al., 1998a, 1998b; capozzi & picotti, 2003) was postulated also by the tectonic pulses (both compressional and extensional) which have affected at different times the various parts of the foothills due to the outward migration of the apennine chain (castellarin & vai, 1986, vai & castellarin, 1992, picotti & pazzaglia, 2008, picotti et al., 2009). in this frame, ricci lucchi (1982) first introduced a sequential framework separating marine (qm) from mainly continental (qc) sequences (fig. 1). later on, vai (1984, 1988) and marabini et al. (1987a, 1987b) emphasized the basic difference between regressive yellow sand (conformably closing the gradual shallowing of the blue clay depositional environment) and transgressive yellow sand bodies (unconformably representing deposits of monoor polycyclic climatically-driven temporary marine ingressions over the uplifting foothill area as already stated by selli, 1949a, 1949b and ruggieri, 1944). an additional distinction was made between yellow sand bodies, marked by cold biotas alternating within the upper blue clay (aa) fm, and yellow sand bodies with warm subtropical biotas characteristic of the transgressive yellow sand cluster (marabini et al. 1996). two different types of midrank cyclicity were singled out in the plio-pleistocene deposits of the apennine foothills separating thrust-top and foreland basins. the shallower thrust-top front-apennine basins, characterized by three main recurrent arctica islandica horizons (fig. 1), are bio-climatically controlled and punctuated by cold peaks within the santernian, emilian, 12 toniato g. et al. and sicilian mediterranean regional substages (with apparent 400 ka eccentricity forcing at about mis 64, 38 -36, 22).the first arctica horizon is developed in clayey facies, part of the second and the third in sandy facies, indicating gradual basin shallowing and infill (blue clay regression). another type of cyclicity is suggested by four main marine sandy bodies intercalated into and topping the blue clay (aa) fm (fig. 1). they are roughly dated around 1.3-1.2 (mis 38-36), 1.05 (mis 30), 0.88 (mis 22), and 0.75 (mis 19-17) (vai 1995, p. 173; marabini et al. 1996, p. 272). the first and third overlap with arctica islandica horizons, consistently with climatically-induced marginal sea-level dropping in a frame of dominating 40 ka obliquity forcing (fig. 1). the fourth instead is provided with warm flora and fauna, suggesting deposition during one or two high sea-level stands of 100 ka eccentricity forcing. the sand bodies appear roughly punctuated by c. 200 and 100 ka recurrence time and were involved in terminal outer apennine folding phases (vai, 1995, p. 173; marabini et al., 1996, p. 272) (fig. 1). both types of lithologic and faunal cyclicity are much better developed in the coeval marginal sicily basins (catalano et al. 1997). the deeper foreland basin presents less or no sand bodies inside the blue clay (aa) fm. a lithostratigraphic formalization (imola sands) and subdivision, required for official geological mapping purposes and suitable for the castel s. pietro to imola area and the related southern po plain core 239-s1, was established by the emilia-romagna geological survey (amorosi et al., 1998a, 1998b; benini et al., 2009). this lithostratigraphy is intimately tied in to a simplified sequence frame. however, both lithoand sequencestratigraphic frames are not straightforwardly correlated outside the imola type area, even in the close wellstudied faenza area, and increasing correlation uncertainty is found outside the foredeep-foreland basin in the nearby thrust-top basins (see also amorosi et al. 1998b, fig. 6). basic tools for dating the “sabbie gialle” have relied upon large mammals and leaves, foraminifera and nannoflora, and palaeomagnetic inversions. continental faunas and leaves that flooded into the coastal sands prompted a villafranchian (equivalent to calabrian) age (scarabelli 1849, 1881) which basically continues into the present age assignment (azzaroli & berzi, 1970, masini et al., 1995, 2013; masini & sala, 2007, ferretti, 1999). in spite of warnings about uncertainty in collecting sites and strata and repeated suggestions that fossils at hand from both past centuries could derive from quite different horizons and rock bodies (vai, 1984, 1988; marabini et al., 1996; torre et al., 1996), vertebrate palaeontologists have steadily assumed the occurrence of a unique yellow sand oriolo fauna of dubious and quite debated late villafranchian or possibly early galerian age (masini et al., 1995) (fig. 1). foraminifera and nannoflora are useful in dating the top of the blue clay (aa) fm and clayey marine fig. 1 lithostratigraphic correlation on a sequential frame tied to geological time, romagna apennine foothills. 13 revised bison skull from the salita di oriolo quarry near faenza, ... intercalations within the overlying transitional sand bodies. unlike biostratigraphic dating of the 1980s, at the end of the century it became clear that, as in the marche area, also in the po plain-adriatic foreland basin continuous blue clay sedimentation reached the late sicilian, above the jaramillo chron, thus placing the imola sands (and other “sabbie gialle”) already within the middle pleistocene (marabini et al., 1996, p. 272; amorosi et al.,1998b, figs 1, 17). reliable magnetostratigraphic sections of reasonable length have been published only by marabini et al., (1996), muttoni et al., (2011) both for the imola-faenza foreland basin and by gunderson et al. (2014) for the front-apennine thrust-top basin in the western part of the northern apennine foothills, beyond the po plain deep core 239-s1 also studied by muttoni et al. (2011). this is mirrored by the lesser thickness and shallower facies of the blue clay fm (aa) in the thrust-top basins and by earlier regression and basin infill, when compared with the imola-faenza basin. an older (~ 100 ka) magnetostratigraphic age of the sabbie di imola in gunderson et al. (2014, fig. 12) vs muttoni et al. (2011, fig. 2) was expected based on the same earlier regression in the western foothills. however, this raises a problem for both lithostratigraphic and chronological correlations. the last two paragraphs above may suggest that the imola sands can be diachronous, as can be expected for any lithostratigraphic unit. but also that not all marine yellow sand bodies nearby must have the same age (and pertain to the same sequence/cycle of the imola sands). only independent and integrated dating tools along with complete and articulated sections can provide reliable answers as to the age of individual sand bodies. within this approach, we try to investigate the stratigraphic significance of the bison skull from salita di oriolo quarry, which was found detached from the remaining skeletal bones and transported by a flood into the marine littoral environment. 3. new field data on some “sabbie gialle” sections s of faenza we examined three quite long “sabbie gialle” sections s of the city of faenza, the two best exposed and well-studied in the past decades, salita di oriolo quarry (marabini et al., 1987a, 1987b; vai, 1988, marabini et al., 1996) and monte coralli trench (not yet published except for some information in amorosi et al. (1998a, 1998b) and vaiani (2000) and unfortunately too superficial to provide magnetostratigraphic response) (fig. 2), and a new unstudied section from the falcona quarry, a presently abandoned quarry with well-preserved walls that could be preserved as geosite with good potential also for further studies. all three sections are strictly part of the same structural-stratigraphic domain, the imolafaenza foreland basin. all are composed by two dominantly sandy marine cycles bounded in outcrop by unconformity surfaces. notice that “two thick sandy layers separated by a muddy interval” were emphasized as the “milazzian” basinward equivalents of the “sabbie gialle” in the po fig. 2 chronological correlation of the salita di oriolo and m. coralli sections in the faenza area. fig. 3 the skull of the salita di oriolo bison in dorsal (a), nuchal (b) and lateral (c) views (maximum width 63 cm). 14 toniato g. et al. plain subsurface studied by selli (1949) in many boreholes. taken together, the two cycles unconformably overlay regressive sandy pelites and mud at the top of the more tectonically deformed blue clay (aa) fm, and are in turn overlain by middle pleistocene mainly pelitic partly pedogenic terrestrial deposits. the two cycles, though more or less yellow and sandy, exhibit common differences in the three sections that are related to lithology, and both lithoand biofacies. the lower (i) cycle (fig. 2) contains some lenticular gravel lags and many thin muddy beds intercalated inside the sand, suggesting alternation of littoral and lagoonal/bay environment with relevant fluvial activity, as indicated also by some layers rich in well-preserved diverse floated leaves accumulation (martinetto & sami, 2001). large mammal fragments are present with juvenile rhinoceros jawbones. the upper (ii) cycle (fig. 2) is more monotonously dominated by medium to coarse well-sorted littoral sand, suggesting a more stable and wider foreshore environment and a dryer climate. if we assume that the two “sabbie gialle” cycles have, at least partly, an orbital climatic forcing (farabegoli & onorevoli, 1991), their individual duration might overlap with one or two obliquity 40 ka intervals (especially the lower) or an eccentricity 100 ka interval (especially the upper cycle) including the erosional-depositional time gap. the salita di oriolo section (fig. 2) is the only out of the three that has provided reliable magnetostratigraphic results (all samples of the other two proved to be remagnetized). as a result, the i cycle is dominantly magnetically reversed and the ii cycle is magnetically normal. according to marabini et al. (1996) top samples of the blue clay (aa) fm and the lower one of the first “sabbie gialle” cycle are reversed. one single normal sample follows (csa 3), which in turn is overlain by a reversed interval up to near the top of the first “sabbie gialle” cycle (csa 4 to 13). the last sample of the lower (i) cycle and the first of the upper (ii) cycle instead are normal. these data have been discussed in detail by marabini et al. (1996, p. 267-270). the normal polarity interval at the top of the cycle (nos. 15, 16) should represent the beginning of the brunhes chron (0.781 ma). in this case, the tiny wiggle (no. 3) could reflect the closest normal event recognized in the matuyama chron, cryptochron kamitsura (0.85, champion et al., 1988; 0.90, coe et al., 2004). worthy to notice, two different magnetostratigraphic campaign (1987 and 1993) have shown a reverse to normal polarity pattern in the same stratigraphic position of sample no. 3, about half a metre beneath the unconformity surface separating the two cycles. alternatively, the no. 3 normal polarity interval is too short to be taken as an evidence for the jaramillo subchron (1.072 0.989). the jaramillo subchrone has been detected in the qm1 member of the aa fm in section a by muttoni et al. (2011, fig. 2) not far from salita di oriolo quarry. it consistently contains nannofossils of “the late early pleistocene part of zone nn 19 (~ 1.02 0.61 ma). however, this small muddy sandy section is interrupted before reaching the “sabbie gialle”. the monte coralli section (fig. 2), some 10 km w of the salita di oriolo section and no longer exposed, is divided into four units by three main unconformity surfaces, all marking minor upward decrease in dip, especially the first and the third ones. the first unit exhibits a transition from massive silty clay (blue clay fm) to finely bedded silty-sandy clay rich in gastropods (mainly turritella layers) and bivalves. the “sabbie gialle” lower (i) cycle contains medium to fine grained foreshore sand with thin clayey to pelitic alternations. the few basal gravel lags are characterized by black-chert pebbles. about 5° dip decrease occurs at the transition to the overlying coastal, coarse-grained “sabbie gialle” upper (ii) cycle, whose basal gravel lags contain common redchert pebbles. the “sabbie gialle” cycle i is much thicker in this section than in the salita di oriolo section, but cycle ii is correspondingly less, giving to the “sabbie gialle” a total thickness of about 48 m. the terrestrial sandy loam topping the “sabbie gialle” is distinctly pedogenic with black mn nodules pervasively developed beneath the present-day land soil (fig. 2). the falcona quarry section, quite close to the m. coralli one, has the great advantage of duplicating most of the features of the monte coralli section, and also represents a well-exposed potential “sabbie gialle” geosite. above the two “sabbie gialle” cycles, the following units were preliminary observed: fluvial deposits of the olmatello fm; heavily pedogenic alluvial plain deposits rich in gilgai periglacial calcic palaeosols (marabini et al. 1987); and possibly late pleistocene alluvial plain deposits with reddish palaeosols (rubinato et al., 2013). these units can be traced physically down to the terrestrial deposits of the alluvial fan belt in the faenza sector of the eastern po plain extensively excavated by pipelines, quarries and wells in the last decades. more generally, the different yellow sand bodies are variously involved in regional tectonics as shown in relevant changes in both thickness and facies sequence (castellarin & vai, 1986, vai, 1989, vai & castellarin, 1993). both “sabbie gialle” cycles in the imola-faenza foreland basin show modest angular unconformity at the base, consistent with vertical uplift tectonics and likely faster uplift rate after the second sandy cycle (fig. 2). earlier sand bodies within the upper part of the aa fm have been hit by the latest early pleistocene (sensu gts 2002) tectonic phase (fig. 1), as shown for the faenza foothills (by the tombe-persolino minor anticline in the rio janna and monte piano area (marabini et al., 1996), and more prominently in the s. mamante section with bed dips over 45° (farabegoli & onorevoli, 1991, farabegoli et al., 1997) not far away from the montoneforlì fault zone. accurate dating of the sand bodies and encasing mudstones is critical to unravel the age of transition from folding (usually occurring still in subacqueous conditions) to uplift (leading to stable emersion) for the different pleistocene basins of the emilia-romagna foothills, and the related yellow sand bodies. 4. the salita di oriolo bison skull the neurocranium, preserved at the civic natural history museum of faenza, was recovered in 1989 by m. diversi and m. sami at the salita di oriolo quarry, near faenza (marabini et al., 1987), one year after the discovery of the mammoth l at the same site. 15 revised bison skull from the salita di oriolo quarry near faenza, ... the fossil land mammals of oriolo all flooded into marine waters were studied in the 1990’s, when the museum’s paleontological collection was completely revised. back then the neurocranium was identified as bison aff. schoetensacki with more primitive features than bison schoetensacki from isernia la pineta (masini et al., 1995). however, recent geological researches on quaternary yellow sands have brought about the need of reconsidering this interpretation by re-examining the fossil bison (fig. 3). 4.1. description and measurements (tab. 1) the bison find from salita di oriolo consists only of the neurocranium. the skull fragment is partially preserved; the left side is slightly more damaged than the right. the horn cores are rather short with a somewhat dorso-ventrally compressed cross section and are lightly furrowed longitudinally. directed laterally and posteriorly at the base, they then bend slightly downwards in ventral direction and curve finally upwards, only to terminate with a rounded tip. this detail can be clearly observed from the right horn core, as the left horn core tip is missing. the frontal bone is quite flat and broken in the orbital region. only the upper margin of the right orbit is preserved revealing rather tubular shaped orbits. the frontal suture is partially fused and extends from the parietal roof down to the level of the supraorbital sulcus. the partial fusion of the frontal suture along with the well-developed horn cores indicate that the specimen was most likely a young-adult. in aboral view, the parietal roof shows a triangular protrusion which culminates in a highly prominent infra temporal bridge. the parietal and temporal crests form a strongly acute angle. the occiput has a trapezoidal, though incomplete, profile. the left condyle is slightly damaged and the left mastoid process as well as both paroccipital processes are missing. 4.2. mammal taxonomy, biostratigraphy, evolution and dispersal into the italian peninsula given that the oriolo specimen likely belonged to a young-adult, the relatively small size of the neurocranium sets it apart from bison menneri, which, according to sher (1997), is characterized by a very large body size. though the discovery of a complete skull of b. menneri has been reported from the site of untermassfeld (kahlke, 2009), no measurements are yet available for comparison; however, the picture of the cranium published by kahlke (2009) seems to display evolved features commonly found in the subgenus bison. likewise, comparison with the cranial cast of the taubach bison priscus and others fragmented ls from settepolesini di bondeno, housed at the ‘piero leonardi’ palaeontological museum of the university of ferrara, confirms the more primitive origin of the oriolo bison. in fact, the b. priscus skull appears much larger and heavier built and differs from the oriolo specimen in that the horn cores are sub-circular and curve readily upwards and the occipit has a rounded arch-like profile as well as a more drawn-back position of the frontal bone. unfortunately, biometric measurements had to be taken principally on horn cores, as most of the comtable 1 (1) least distance between the horn core tips, (2) greatest tangential distance between the outer curves of the horn cores, (3) length of the horn core upper side, (4) length of horn core lower side, (5) taut length (chord) of the horn core, (6) horn core basal circumference, (7) least (dorso-basal) diameter of the horn core base, (8) least (oro-aboral) diameter of the horn core base, (9) narrowness index of the horn core base, 7÷8 x 100, (10) greatest breadth of the occipital condyles, (11) height of the foramen magnum. 16 toniato g. et al. parative material was poorly preserved and lacked of substantial cranial portions. though biometry proved difficult and the results were meagre, it seems evident that the size range of the oriolo neurocranium does not overlap with that of any other species. this is consistent with the results of morphological comparison. considerable differences separate the oriolo bison from bison voigtstedtensis and bison schoetensacki. these principally concern the occipital region, which is wider and more compressed, almost sub-circular, in both b. voigtstedtensis and b. schoetensacki, and the horn cores, which are shorter and directed obliquely backwards in b. voigtstedtensis displaying an array of different morphological characters, being more swollen at the base, less curved and tapering quickly upwards. by contrast, the horn cores of the oriolo bison form an angle of approximately 90 degrees with the frontal plane and curve outwards and slightly downwards before pointing upwards, resembling quite closely those of bison (eobison) tamanensis, especially in the marked dorso-ventral flatness of the base. other striking similarities are to be noted with the subgenus bison (eobison), in particular the deep infratemporal fossae and high occiput. these two features are present in bison (eobison) palaeosinensis(teilhard de chardin & piveteau, 1930) and in the younger bison (eobison) degiulii masini 1989. though, in the latter the constriction between the occipital region and the parieto -frontals is narrower and the occipital region is smaller (masini et al., 2013). direct comparison with the holotype of bison (eobison) degiulii masini 1989, temporarily preserved at the natural science department of the university of firenze, enabled these observations. as opposed to b. (eobison) degiulii, the oriolo specimen also shows a less swollen forehead and a broader occipital region. moreover, in b. (eobison) degiulii the infratemporal fossae are narrower and more elliptical. thus, these features of the oriolo bison seem to indicate a younger age than that of b. (eobison) degiulii of the pirro fu, which is ascribable to the late villafranchian, before the end of the early pleistocene (fig. 1). the genus bison makes its appearance in the italian peninsula during the late early pleistocene, late villafranchian, with bison (eobison) degiulii, first recorded in the karstic fissure fillings of pirro nord, at the western border of the gargano peninsula (de giuli et al., 1986). this species occurs also in the italian fossil record of the late villafranchian (sensu gliozzi et al., 1997, masini & sala, 2007) in various areas, such as the mugello and upper valdarno basins and at capena, near rome (masini, 1989). the use of the subgenus eobison was proposed by flerov (1975, 1979), who decided to group together, on the basis of fossil evidence, all the small lightly built primitive bison forms of the early pleistocene. these include several species, like bison tamanensis vereshchagin, 1957 (taman peninsula, russia), bison palaeosinensis teilhard & pivetau, 1930 (nihowan, china), bison sivalensis lydekker, 1876 (siwalik, pakistan), bison degiulii masini 1989 (pirro nord, italy) and the bison sp. of venta micena (spain). according to bukhsianidze (2005), the remains of dmanisibos georgicus vekua 1995, renamed bison (eobison) georgicus, represent the oldest known bison record in europe, suggesting that the genus originated from leptobos as far back as the middle to late villafranchian transition, but masini et al. (2013) prefer to take this classification cautiously. other bison remains, assigned to the subgenus bison (eobison) (moyà-solà, 1987), were unearthed in the iberian peninsula, at the site of venta micena, which, according to recent comparative studies based on the faunal assemblage (martínez-navarro et al., 2011), could be slightly younger than dmanisi with an estimated age around 1.5-1.6 ma. however, the scantiness and poor preservation of these remains do not allow a secure classification. the earliest representative of the true bison in europe (the subgenus bison) is bison menneri, which is well-attested in the fossil-rich epi-villafranchian (early galerian for the italian biochronology) fluvial sediments of untermassfeld. its large and long-legged structure, probably an adaptation to woodland habitats (sher, 1997), makes it the biggest known european fossil bison. during the middle pleistocene, new bison forms enter the italian fossil record. bison schoetensacki, is attested in the fossiliferous breccia of slivia (ambrosetti et al., 1979) and is believed to belong to the same lineage of bison schoetensacki voigtstedtensis (fischer, 1965), though flerov (1975) considers it a distinct species. the progressive climatic decline and the arrival of the steppe bison, bison priscus, during the late galerian, determined the extinction of b. schoetensacki from the italian peninsula. in this framework, the peculiar mixture of bisontine characters of the oriolo neurocranium makes it a unique find within the italian early pleistocene fossil record. indeed, biometrical and morphological comparison with other cranial remains of early and middle pleistocene bison species does not allow definitive species identification, but accounts for important evolutionary changes in morphology. the trapezoidal profile of the occipit and the narrow constriction between the occipital bone and the parietal roof recall primitive features, similar to those of bison (eobison) degiulii, while the marked flatness of the horn cores, regarded as a distinctive character among early bison forms, resembles that of bison tamanensis. the latter is believed to be the oldest european bison, that appeared in eastern europe at the end of the villafranchian (flerov, 1979). yet, in her recent work, vislobokova (2008) correlates the tamanian faunal assemblage with the early galerian of western europe, specifically with the colle curti and untermassfeld local faunal assemblages, assigning the tamanian bison to the subgenus bison. whatever the opinion of the various authors on the subgenus of the tamanian bison, the morphological features of the oriolo specimen are comparable to those exhibited by the bison (eobison) fossil species of the late villafranchian. yet, the high occipital region and in particular the broader infra-temporal bridge of the oriolo neurocranium are probably advanced characters that indicate a younger age than that of b. (eobison) degiulii. in conclusion, revision of the taxonomic classifica 17 revised bison skull from the salita di oriolo quarry near faenza, ... tion of the bison neurocranium of oriolo adds new elements to our knowledge of the early bison forms that inhabited the italian peninsula. biometrical and morphological comparisons suggest a strong affinity with bison (eobison) fossil species, that are to be observed in the marked flatness of the horn cores near the base, the trapezoidal profile of the occipital region, the deep infra-temporal fossae and the notably constricted infra-temporal bridge. however, certain morphological features such as the high occipital region and broader infra-temporal bridge appear to be more evolved than in b. (eobison) degiulii, implying an age younger than that of the pirro fu, that falls nonetheless within the late villafranchian upper boundary (fig. 1). it is hard to admit the coeval presence of two bisons of different subgenera in northern italy and central europe given that the faunal composition in northeastern italy throughout the whole quaternary comprises species of central european provenience, in opposition to those of the ligurian-tyrrhenian versant and of southern italy. thus, the oriolo bison, which for its morphology is assigned to the eobison subgenus, should be older than bison menneri from untermassfeld, which belongs to the subgenus bison and can be roughly correlated with mis 31. 5. general stratigraphic discussion the new taxonomic assignment of the salita di oriolo skull to bison (eobison) sp. as opposed to its previous identification as bison aff. schoetensacki (masini, 1989, masini et al., 1995), implies an age of the lower “sabbie gialle” cycle (from which it was supposed to come from till now by many authors) possibly older than previously thought. this applies if the large mammal biochronology of central and northern europe, as presently known, may be assumed to be reliable also for southern europe. to correctly answer this question (1) the sampling position of the bison in the salita section must be clarified, and (2) an integrated critical review of the most relevant dating sources of deposits in the imola-faenza “sabbie gialle” basin needs to be performed. at the end of quarrying activities in the mid-1990s the salita di oriolo quarry was buried under tens of m of residual detritus, except for a minor lateral wall of sand and mudstone still exposed up to 2 to 3 m of thickness in the deepest (and stratigraphically oldest) westernmost part of the abandoned quarry, where a small farm lake was excavated. what is left today of these beds was sampled recently by muttoni et al. (2011, fig. 2, section d) and proved to pertain to a reverse palaeomagnetic interval, but was mistakenly placed by these researchers on top of the littoral “yellow sand” containing mammuthus meridionalis according to marabini et al. (1996, fig. 4). to restore a less fanciful and more reliable stratigraphy of the salita section, we have reviewed all our original field data from 1987 to 1993 to better constrain the sampling position of the large mammals (masini, 1989, masini et al., 1995, ferretti, 1999). the updated stratigraphic column of the salita di fig. 4 the westernmost part of salita di oriolo quarry in 1988 (photo by m. sami). white star (top right) indicates the projected stratigraphic position of the elephas (mammuthus) meridionalis skull found in the eastern part of the quarry; geologists are extracting remains of a juvenile rhinoceros from the sand; the digging place of the bison skull is the whitish outcrop just behind the red van. see fig. 2 for the relative stratigraphic position of the large mammal bones. 18 toniato g. et al. fig. 5 western end of the salita di oriolo quarry in 1987 (photo by g.b. vai). main unconformities separating the two marine “sabbie gialle” cycles, and the gilgai rich terrestrial deposits on top are shown. again, white star (top right) indicates the projected stratigraphic position of the elephas (mammuthus) meridionalis skull found in the eastern part of the quarry. fig. 6 digging the elephas (mammuthus) meridionalis skull at the western end of salita di oriolo quarry in 1987 (photo by g.b. vai). an umbrella and a white star indicate the digging and stratigraphic place of the elephas near the top of “sabbie gialle” cycle ii, at an altitude equivalent to the nearby country home roof (about 110 m a.s.l.). 19 revised bison skull from the salita di oriolo quarry near faenza, ... oriolo quarry (fig. 2) basically repeats descriptions and figures given by marabini et al., 1987a, 1987b; vai, 1988, marabini et al., 1996. new features are: (1) the downward extension of the column to incorporate data from an exploration trench of 1988; (2) the revised sampling position of the bison skull in the stratigraphically lowermost trench of the quarry, possibly in the deepest sandy body available to exploitation; it follows that the bison was emplaced at the top of the argille azzurre fm; (3) the replacement of the bison, drawn in wrong position in the column of marabini et al., 1996 (fig. 4), with a juvenile rhinoceros’ jawbone (found by amateurs who mistakenly held that it had been excavated at about the same level of the bison). slides taken in 1988 clearly show the sampling place of bison and rhinoceros in the western part of the quarry (fig. 4), and the sandy layer yielding the mammuthus skull at about 150 metres to the e (figs. 5, 6, 7, 8); (4) the two unconformities separating the lower regressive sands (“sabbie gialle” i cycle) from the upper transgressive littoral sands (“sabbie gialle” ii cycle), and in turn these “sabbie gialle” from the uppermost terrestrial deposits are clearly though slightly angular (especially the upper one) (fig. 3, 5); (5) the terrestrial deposits on top of the salita di oriolo section are now better correlated to the periglacial gilgai deposits (suoli a cuspidi e depressioni in marabini et al. 1987a, p. 33) (fig. 5, 7) rather than to the olmatello fm (vai, 1984, marabini et al., 1996), which instead is probably present on top of the falcona section. according to amorosi et al. (1998a, p. 86) and vaiani (2000), clays and silts of the uppermost argille azzurre (aa) fm based on strontium isotope stratigraphy are associated with a latest early pleistocene (or sicilian) age (qm1 marine sequence); the following transitional to marine (qm2) sequence has an earliest middle pleistocene (or ‘ionian’) age (fig. 1). their biostratigraphic analyses, though consistent with the above dating, have not provided marker fossils of closer resolution. however, a top sicilian age for the uppermost aa fm in the faenza sections is supported by three peaks of “northern guests” in the romagna apennines (marabini et al., 1996, p. 271; vai, 1995, p. 173) which correlate with the three northern mollusc migrations in sicily (raffi 1986). note, however, the quite different ages given by various authors to the top of the sicilian substage (see f.e. amorosi et al., 1998b, fig. 4), waiting for a formal definition of the ‘ionian’ gssp (fig. 1). even more important are the new biostratigraphic data in muttoni et al., 2011 (tab. 1), which report gephyrocapsa sp. 3 from their lower c section (that is correlated with the imo 1 member of the imola sands) suggesting deposition during late early-middle pleistocene part of zone nn19 (about 1.02-0.61 ma) that is latest sicilian to early ‘ionian’. it should be pointed out that all such isotopic and faunal dating elements derive from clayey intercalations in pure muddy or partly sandy aa fm that always fig. 7 tracing the salita di oriolo section from east to west across the quarry in 1987 (photo by g.b. vai). two main unconfomities are shown. the lower separates the marine “sabbie gialle” ii cycle heavily rubefacted on top and gently dipping 9°-10° to ne from the overlying almost flat terrestrial gilgai-rich deposits, in turn deeply incised by late pleistocene fluvial deposits (upper unconformity). lighter coloured layer on top is a detrital nappe artefact. 20 toniato g. et al. underlie our “sabbie gialle” first sandy cycle, except for section c which indeed could perhaps overlap our first sandy cycle. to sum up, revised original field data definitely show that the mammuthus skull of the salita di oriolo quarry was excavated from sands lying stratigraphically about 25 m higher than the revised bison l and some 150 m east of it (fig. 8). new stratigraphic evidence more firmly supports an early middle pleistocene age of the “sabbie gialle” cycle ii in the faenza foothills yielding a mammuthus meridionalis skull. the underlying “sabbie gialle” cycle i is best correlated with the upper part of the matuyama reversed chron, most probably above the jaramillo subchron. as the layers containing the bison sand body have resulted also to be reversed (marabini et al. 1996, muttoni et al., 2011), it follows that the skull might actually correlate with an early pleistocene sicilian age slightly younger or slightly older than the jaramillo subchron. to clarify this uncertainty further investigations are advocated for detecting the jaramillo subchron in the thick, better exposed faenza sections, showing transition from blue clay (argille azzurre) fm to yellow sand bodies, as the falcona and equivalent sections. acknowledgements we are indebted to marco sami (museo di scienze naturali faenza) for providing a colour slide of quarrying operation in 1988, and to the brothers battista and roberto geminiani for technical assistance in the field work. references ambrosetti, p., bartolomei, g., de giuli, c., ficcarelli, g., torre, d. (1979) la breccia ossifera di slivia (aurisinasistiana) nel carso di trieste. bollettino società paleontologica italiana, 18 (2), 207-220. amorosi a., caporale l., cibin u., colalongo m.l., pasini g., ricci lucchi f., severi p., vaiani s.c. (1998a) the pleistocene littoral deposits (imola sands) of the northern apennines piedmont. giornale di geologia, 60, 83-118. amorosi a., barbieri m., castorina f., colalongo m.l., pasini g., vaiani s.c. (1998b) sedimentology, micropaleontology, and strontium-isotope dating of a lower-middle pleistocene marine succession (“argille azzurre”) in the romagna apennines, northern italy. bollettino società geologica italiana 117, 789-806. azzaroli a., berzi a. (1970) on an upper villafranchian fauna at imola, northern italy, and its correlation with the marine pleistocene sequence of the po plain. palaeontographia italica, 66, 1-12. bukhsianidze m. (2005) the fossil bovidae of dmanisi, phd, dissertation. the international doctorate “environmental, humans and compartmental fig. 8 air photo and google map views of large mammal fauna sampling sites in the former salita di oriolo (near faenza) quarry, including bison (red star) and one side and mammoth (yellow star) on the other side. 21 revised bison skull from the salita di oriolo quarry near faenza, ... dynamics” xvi cycle 2001-2004, university of ferrara. pp. 192. castellarin a., vai g.b. (1986) southalpine versus po plain apenninic arcs. in: wezel f.c. (ed), the origin of arcs, amsterdam, elsevier, 253-280. catalano r., di stefano e., infuso s., sulli a., vail p.r., vitale f.p. (1997) sequence and systems tracts c a l i b r a t e d b y h i g h r e s o l u t i o n b i o chronostratigraphy: the centrtal mediterranean plio-pleistocene record. in: catalano r. (ed), time scales and basin dynamics. 8th workshop ilp task force “origin of sedimentary basins”, field guidebook, 107-132. champion d.e., lanphere m.a., kuntz m.a. (1988) evidence for a new geomagnetic reversal from lava flows in idaho: discussion of short polarity intervals in the brunhes and late matyama polarity chtons. journal geophysical research, 93, 1166711680. coe r.s., singer b.s., primgle m.s., zhao x. (2004) matuyama-brunhes reversal and kamikatsura event on maui: paleomagnetic directions, 40ar/39ar ages and implications. earth planetary science letters, 222, 667-684. de giuli c., masini f., torre d. (1986) the latest villafranchian faunas in italy: the pirro nord fauna (apricena, gargano). palaeontographia italica, 74, 56-62. farabegoli e. (1985) note geologiche dul territorio di s. lazzaro di savena. in: lenzi f., nenzioni g., peretto c. (cur), materiale edocumenti per un museo della preistoria. catalogo. nuova alfa editoriale bologna, 13-26. farabegoli e., onorevoli g. (1991) la sezione di s. mamante (faenza) nel quadro evolutivo neotettonico ed eustatico del quaternario dell'appennino romagnolo. mem. descr. carta geol. d’it., 46, 417432. farabegoli e., onorevoli g., ruffino c., costantini b. (1997) struttura del sottosuolo quaternario continentale della pianura padana meridionale (provincia di ravenna italia). università di bologna e agip, 12 tables. ferretti m.p. (1999) mammuthus meridionalis (mammalia, proboscidea, elephantidae) from the" sabbie gialle" of oriolo (cava la salita, faenza, northern italy) and other european late populations of southern mammoth. eclogae geologicae helvetiae, 92(3), 503-515. fischer k.h. (1965) bison reste (bison schoetensacki voigtstedtensis ssp. n.) aus den altpleistozänen tonen von voigtstedt in thüringen. paläontologische abhandlungen, abteilung a. paläozoologie, 2, 2-3, 364-377. flerov c.c. (1975) die bison reste aus der travertinen von weimar-ehrigsdorf. palaeont. abh., 23, 171-99. flerov c.c. (1979) systematic and evolution. in: sokolov, v. f., eds.: european bison, 475 pp, moskow. gliozzi e., abbazzi l., argenti p., azzaroli a., caloi l., capasso barbato l., di stefano g., esu d., ficcarelli g., girotto o., kotsakis t., masini f., mazza p., mezzabotta c., palombo m.r., petronio c., rook l., sala b., sardella r., zanalda e., torre d. (1997) biochronology of selected mammals, molluscs and ostracods from the middle pliocene to the late pleistocene in italy. the state of the art. riv. ital. di paleont. e stratigr., 103, 3, 369388. gunderson k., pazzaglia f.j, picotti v., anastasio d.a., kodama k.p., rittenour t., frankel k.f., ponza a., berti c., negri a., sabbatini a. (2014) unraveling tectonic and climatic controls on synorogenic growth strata (northern apennines, italy). gsa bulletin, 126, 532-552. kahlke r.d. (2009) les communautés de grands mammifères du pléistocène inférieur terminal et le concept d'un biochrone épivillafranchien. quaternaire, 20, 4, 415-427. marabini s., costa g.p., giusberti g., sami m., taviani m., ricci lucchi f., vai g.b. (1987a) rinvenimento di un cranio di elephas nella parte alta delle “sabbie gialle” presso faenza (pleistocene). rendiconti società geologica italiana 10, 55-58. marabini s., taviani m., vai g.b, vigliotti l. (1996) yellow sand facies with arctica islandica: low stand signature in an early pleistocene frontapennine basin. giornale di geologia 57, 259275. martinetto e., sami m. (2001). paleoflora delle “sabbie gialle” medio-pleistoceniche di oriolo, presso faenza (ravenna). quaderno studi notizie storia naturale romagna, 14, 1-28. martínez-navarro b., ros-montoya s., espigares m. p., palmqvist p. (2011) presence of the asian origin bovini, hemibos sp. aff. hemibos gracilis and bison sp., at the early pleistocene site of venta micena (orce, spain). quaternary international, 243, 1, 54-60. masini f. (1989) i bovini villafranchiani dell’italia. phd dissertation, university of modena and florence, pp. 152. masini f., abbazzi l., ferretti m., mazza p. (1995) fauna a mammiferi terrestri dalle «sabbie gialle» quaternarie di imola. in: pacciarelli m., vai g.b. (cur) la collezione scarabelli, 1, 314-318. masini f., palombo m.r., rozzi r. (2013) a reappraisal of the early to middle pleistocene italian bovidae. quaternary international, 288, 45-62. masini f., sala b. (2007) largeand small-mammal distribution patterns and chronostratigraphic boundaries from the late pliocene to the middle pleistocene of the italian peninsula. quaternary international, 160, 43-56. muttoni g., scardia g., kent d.v., morsiani e, tremolada f., cremaschi m., peretto c. (2011) first dated human occupation of italy at 0,85 ma during the late early pleistocene climate transition. earth planetary science letters, 307, 241252. moyà-solà s. (1987) los bóvidos (artiodactyla, mammalia) del yacimiento del pleistocenoinferior de venta micena (orce, granada, españa). paleontologia i evolució, memoria especial, 1, 181-236. 22 toniato g. et al. ms. received: july 5, 2016 final text received: december 5, 2016 picotti v., pazzaglia f.j. (2008) a new active tectonic model for the construction of the northern apennines mountain front near bologna (italy). journal of geophysical research 113, b08412. doi: 101029/2007jb005307. picotti v., ponza a., pazzaglia f.j. (2009) topographic expression of active faults in the foothills of the northern apennines. tectonophysics 474, 285 -294. raffi s. (1986) the significance of marine boreal molluscs in the early pleistocene faunas of the mediterranean area. palaeogeography palaeoclimatology palaeoecology 52, 3-4, 267-289. doi: 10.1016/0031-0182(86)90051-9 ricci lucchi f., colalongo m.l., cremonini g., gasperi g., iaccarino s., papani g., raffi i., rio d. (1982) evoluzione sedimentaria e paleogeografica del margine appenninico. in: cremonini g., ricci lucchi f. (cur), guida alla geologia del margine appenninico-padano. guide geologiche regionali società geologica italiana, bologna, 17-46. rubinato g., sami m., fanti f., marabini s., sala b., vai g.b. (2013) terrestrial vertebrates in mis 6 to mis 5 deposits of the zannona quarry (faenza, italy). alpine and mediterranean quaternary, 26, 55-63. ruggieri g., (1944) il calabriano e il siciliano nella valle del santerno. giornale geologia, 2, 17 (1943 -1944), 95-113. ruggieri g., selli r. (1949, 1950) il pliocene e il pstpliocene dell’emilia. giornale geologia, 20, 114; xviii int. geol. congress, london 1948, 9, 8593, london. sala b. (1986) bison schoetensacki freud from isernia la pineta (early mid-pleistocene, italy) and revision of the european species of bison. palaeontographia italica, 74, 113-170. scarabelli g. (1849) sui depositi delle ossa fossili esistenti nell’imolese. nuovi annali delle scienze naturali, 2, 10, 297-302. scarabelli g. (1881) carta geologica del monte castellaccio e dintorni presso imola. virano e teano roma. selli r. (1949a) smottamenti costieri avvenuti durante il siciliano al margine dell’appennino bolognese. atti xiv congr. geol. it., 387-388. selli r. (1949b) le conoscenze geologiche sul quaternario gassifero del polesine e del ferrarese settentrionale. atti vi convegno nazionale per il metano, succ. penada stampatori padova, p. 515537. selli r. (1962) le quaternarie marin du versant adriatique jonien de la peninsule italienne. quaternaria 6, 391-413. she a.v. (1997) an early quaternary bison population from untermassfeld: bison menneri sp. nov. das pleistozän von untermassfeld bei meiningen (thüringen), teil 1, 101-180. torre d., albianelli a., bertini a., ficcarelli g., masini f., napoleone g. (1996) paleomagnetic calibration of plio-pleistocene mammal localities in central italy. acta zool. cracov., 39, 1, 559-570. teilhard de chardin p., piveteau j. (1930) les mammifères fossiles de nihowan (chine). masson et cie, pp. 136. vai g.b. (1984) quando barrivano sul castellaccio gli ultimi elefanti. in: pagine di vita e storia imolesi, cars imola, 2, 195-219. vai g.b. (1988) a field trip guide to the romagna apennine geology: the lamone valley. in: de giuli c., vai g.b. (eds.), fossil vertebrates in the lamone valley, romagna apennines, int. work. "continental faunas at the miocene/pliocene boundary, 7-37. vai g.b. (1989) migrazione complessa del sistema fronte deformativo-avanfossa-cercine periferico: il caso dell'appennino settentrionale. memorie società geologica italiana 38 (1987), 95-105. vai g.b. (1995) introduzione alla geologia dell’appennino nord-orientale, sulle orme di scarabelli. in: pacciarelli m., vai g.b.(cur.), la collezione scarabelli 1. geologia, musei civ. imola cat. raccolte, grafis ed., 154-177. vai g.b., castellarin a. (1993) correlazione sinottica delle unità stratigrafiche nell'appennino settentrionale. studi geol. camerti, vol. spec. (1992/2) crop 1-1a, 171-185. vaiani s.c. (2000) testing the applicability of strontium isotope stratigraphy in marine to deltaic pleistocene deposits: an example from the lamone river valley (northern italy). journal of geology 108, 585-599. vereshchagin n.k. (1957) mammal remains of the lower quaternary deposits of the taman peninsula, vol. 22, trudy zoological institute, leningrad, 9-49. vislobokova i.a. (2008) the major stages in the evolution of artiodactyl communities from the pliocene-early middle pleistocene of northern eurasia: part 1. paleontological journal, 42, 3, 297-312. 23 revised bison skull from the salita di oriolo quarry near faenza, ... 24 amq 32(1) i-iii zanchetta leone.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 32 (1), 2018, i iii francesco paolo bonadonna: a tale of a quaternarist gabriello leone, giovanni zanchetta francesco paolo bonadonna (known to everyone as “antonello”) passed away on november 2017. born in rome in 1934 and graduated in geological science in 1961 at the local university, he dedicated all his life to scientific research and teaching. notably, during the 60s/80s of the last century, he was considered an actual innovator in the application of the geochemical and geochronological techniques to the quaternary geology. he worked in rome until 1968 starting as a stratigrapher, exemplary for those years are his works on the stratigraphy of the lazio region, on a paleoecological and paleoclimatological base, carried on along with his colleague p. ambrosetti (bonadonna, 1968). moreover, he devoted himself to the study of diatoms and varved deposits within the uppsala university. upon his arrival at the university of pisa with the purpose of studying the geochronology of quaternary successions, he establishes himself as an eclectic researcher within the nuclear geology laboratory, an innovative university institute and a melting pot of ideas and scientific minds created and led by ezio tongiorgi. in this framework, he designs and makes operational, along with colleague claudio arias, a laboratory of palaeomagnetic measures (arias et al., 1980, 1984); he also collaborates, along with giulio bigazzi, to the development of distal tephrostratigraphy and tephrochronology, using the fission tracks method (bigazzi & bonadonna, 1988; bigazzi et al., 1996), a methodology used, with great intuition, also for the identification of exploitation areas of obsidian during the neolithic period (bonadonna & bigazzi, 1973). he publish a summary document of the quaternary chronostratigraphy of the italian regions (ambrosetti et al., 1972), and he works on the construction of magnetostratigraphic scales of neogenic and quaternary sediments of the mediterranean basin. throughout his career he is also active in the reconstruction of the relative sea level variations: for many years he is vice-president of the inqua subcommittee for the mediterranean area (bonadonna & campetti, 1987). it is also remarkable his dedication to work alongside archeologists: he was appointed as the geology expert during several archaeological campaigns in the libyan sahara region during the 70s and the 80s, published several articles with geoarchaeology and archaeometric contributions, and was a lecturer for the prehistoric archeology graduate school in pisa from 1968. starting from halfway in the 80s, he began a long scientific partnership with gabriello leone, who was already active in the field of stable isotopes geochemistry, working intensively on the palaeoclimatic and palaeoenvironmental applications of methodologies based on the isotopic composition of oxygen and carbon. he focuses in particular on the continental successions, in the mediterranean and south american areas (bonadonna & leone, 1995; bonadonna et al., 1999), an activity in which, from the late 90s, he receives great contribution from his former student giovanni zanchetta. during all his career he nurtures and disseminates his belief on the importance of a multidisciplinary approach to scientific research, underlining the importance of a continuous large-scale correlation between geological, biological and climatic events, for a better comprehension of the history of the planet, in particular on the last 5 ma of the earth history in the mediterranean area, but also on a global scale (ambrosetti et al., 1972; bonadonna & alberdi, 1987; alberdi & bonadonna, 1989; zanchetta et al., 1995). in his last years of the academic career he dedicated himself to the study of the successions of the lower valdarno and coastal tuscany areas (zanchetta et al., 2004), and of central and southern italy, in order to find, with his multidisciplinary approach, large scale correlations between the events that characterized the area during the last mya. moreover, it is not possible to forget the long lasting contribution of bonadonna to the debate of the quaternary lower boundary he strongly suggested to be placed at ca. 2.5 ma. the national, and part of the international scientific community, relegated him in a marginal posi ii tion. time has proven him right. he lectured university courses at the university of camerino, adis abeba and finally as an associate professor in the university of pisa: for many years he was academic of quaternary geology and paleontology, then of geology for the environmental sciences degree. he also lectured in geology for the cultural heritage degree, teaching even after his retirement. during his teaching tenure he tried to instill his passion and enthusiasm to all the student, young and not-so-young that crowded the so called “green laboratory” of via s. maria in pisa: passion and enthusiasm that were always moderated by his renowned scientific conscientiousness. a man with a strong personality and strict principles; he was not willing to compromise and showed a considerable polemic and ideological vein, he was all the life an irreducible "companion", antonello was a difficult person. he was a person devoid of sentimentality and expression of affection, nevertheless he was all the time a generous person, always close to the people who needed and always ready to help students and colleagues in need. in difficult times he was always a person to talk to. on the other hand, he never asked for help: when he suffered a heart attack at the university, he went alone walking to the nearby hospital without telling anybody! this harsh and hard character often brought him into sharp contrast with the official academic world and clearly limited his university career. however, he was never worried about the consequences of his convictions. a tireless and attentive reader of the scientific literature, no matter how early we arrived at the university he was already on his desk reading a pile of papers; he was always up-to-date and he was curating meticulously the citations. lastly, he was open-minded to all the innovation brought by the development of analytics and informatics, on the other hand he was also reminding us that in our field technology was only an instrument for getting knowledge of the causes and to reconstruct the events that occurred in an interval of time of the history of our planet. his wide and extensive scientific production, leone g. & zanchetta g. antonello bonadonna in the field. the autcrops is the fluvial gravels at the base of the s. romano formation of probable mis 12 age. the definition of this unit was one of his last field activity. more than one hundred and fifty publications, is there to witness the consistency of his objectives, enriched by the vastness of his interests, the curiosity for new techniques and his rigorous approach. this volume has the purpose of recollecting the contributions by some of the people who had known him or that have beneficiated from his work as a well-rounded “quaternarist”, remembering the scientist and the man, a distinction, which sometimes proves to be very difficult for those who live and breathe this beautiful profession. gabriello leone and giovanni zanchetta * *g. leone and g. zanchetta have been, in different times and modality, scholars and partners of “antonello”, to whose figure as a man of science and a colleague, they owe a lot. references adkins j.f., boyle e.a., curry w.b., lutringer a. (2003) stable isotopes in deep-sea corals and a new mechanism for vital effects. geochimica et cosmochimica acta, 67, 1129-1143. alberdi m.t. bonadonna f.p. (editors) (1989) geología y paleontología de la cuenca de guadix-baza., museo nacional de ciencias naturales, csic, madrid, 79-95. ambrosetti p., azzaroli a., bonadonna f.p., follieri m. (1972) a scheme of pleistocene chronology for the tyrrhenian side of central italy. boll. soc. geol. ital., 91, 169-184. ambrosetti p., bonadonna f.p. (1967) revisione dei dati sul plio-pleistocene di roma 1967. atti accademia gioenia di sc. nat. in catania, 18, 33-70. arias c., bigazzi g., bonadonna f., brunnacker k., urgan b. (1984) correlation of plio-pleistocene deposits of the lower rhine basin (north-west germany) and the valle ricca pits (central italy). quat. sc. rev. 3, 73-89 arias c., azzaroli a., bigazzi g., bonadonna f. (1980) magnetostratigraphy and pliocene-pleistocene boundary in italy. quat. res., 13, 65-74. bigazzi g., bonadonna f.p. (1988) fission track dating of a volcanic ash layer near pisticci (basilicata, italy). alpine and mediterranean quaternary, 1, 127-129 bigazzi g., bonadonna f.p., zanchetta g. (1996) farola monte hermoso: fission-track dating of darwin's mammals deposit in argentina. journal of quaternary science 11, 423-426. bonadonna f.p. (1968) studi sul pleistocene del lazio. v. la biostratigrafia di monte mario e la “fauna malacologica mariana” di cerulli-irelli. mem. soc. geol. it, 7, pp. 261-321. bonadonna f.p., campetti s. (1987) annotated bibliography of italian quaternary shorelines (1970-1984): subcommission on mediterranean and black sea shorelines. f.p. bonadonna editor, pacini editore, pisa, 480 pp. bonadonna f.p., alberdi m.t. (1987) equus stenonis cocchi as a biostratigraphical marker in the neogene-quaternary of the western mediterranean basin: consequence on galerian-villafranchian chronostratigraphy. quaternary science reviews, 6 55-66. bonadonna f.p., bigazzi g. (1973) fission track dating of the obsidian of lipari island (italy). nature 242, 322-323. bonadonna f.p., leone g. (1995) palaeoclimatological reconstruction using stable isotope data on continental molluscs from valle di castiglione, roma, italy. the holocene, 5, 461-469. bonadonna f.p., leone g., zanchetta g. (1999) stable isotope analyses on the last 30 ka molluscan fauna from pampa grassland, bonaerense region, argentina. palaeogeography, palaeoclimatology, palaeoecology 153, 289-308. zanchetta g., bonadonna f.p., marcolini f., ciampalini a., fallick a.e., leone g., michelicci l. (2004) intra-tyrrhenian cooling event deduced by a non-marine mollusc assemblage at villa s. giorgio (livorno, italy). bollettino della societa paleontologica italiana, 43, 331-343. zanchetta g., alberdi m.t., bonadonna f.p., leone g. (1995) escenario de la evolución climática entre la región pampeana y el área del mediterráneo occidental durante el cuaternario. in: alberdi m.t., leone g. y tonni e.p. (editores), evolución biológica y climática de la región pampeana durante los últimos 5 millones de años. un ensayo de correlación con el mediterráneo occidental. monografías del museo nacional de ciencias naturales (csic), madrid, 407-423. iii francesco paolo bonadonna: a tale of a quaternarist iv amq_28(1) coloph 3.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 28 (1), 2015, 71 92 quaternary evolution of the plain between casale monferrato and valenza: implications for the tectonics of the monferrato thrust front (piedmont, nw italy) carlo giraudi enea c.r. saluggia, vercelli, italy corresponding author: c. giraudi <carlo.giraudi@enea.it> abstract: the present paper highlights the quaternary evolution of the plain which lies on the eastern portion of the monferrato thrust front, in order to identify and provide evidence of recent tectonic deformations. the study has made it possible to detect and date late middle pleistocene or early upper pleistocene tectonic deformations related to the activity of the front, and to suggest the hypothesis of more recent ones. it can be observed that some parts of the plain, located north of the thrust fronts and the area corresponding to some buried synclines, mainly subsided during the quaternary. on the other hand the area of the isolated hills and terraces suffered an almost continuous uplift until the late middle pleistocene or early upper pleistocene. the areas where the uplift prevailed were affected by faults both transversal and parallel to the thrust fronts. the overall interpretation of the tectonic structures lying below the plains and on the hills has enabled us to assume that there are two deformation zones where strike-slip or oblique-slip displacements took place. in the first one (giarole-lu deformation zone) some left-slip tectonic deformations should exist, while in the second one (valenza deformation zone) some right-slip displacements may be present. the movements along the two deformation zones would result in an advance towards the north of the thrust front near the isolated pomaro-montevalenza hill. in the eastern monferrato contractional tectonics related to the monferrato thrust front was more recent than in the central and western monferrato. the subsidence of the northern alessandria piggyback basin, that lasted until the late middle pleistocene or the early upper pleistocene, would be a consequence of the shift towards the north of the thrust front. the horizontal and vertical deformation rates obtained by the alessandria gps station seem compatible with the hypothesis of a shift to the north and with a subsidence still in progress. the morphology and distribution of the most recent terraces suggest that part of the po plain may have been affected by upper pleistocene and holocene tectonic movements. these areas include casale monferrato, which underwent a remarkable aseismic uplift during the twentieth century. keywords: terraces, quaternary evolution, monferrato thrust front, transverse fault, po plain, piedmont, italy. 1. introduction recent studies on the buried tectonic structures covered by fluvial sediments of the po plain have suggested that the monferrato thrust front, despite being subject to very low seismic activity, may be considered a seismogenic structure capable of producing earthquakes of high magnitude. according to burrato et al. (2012) and michetti et al. (2012), the present seismicity of the area could be characterized by earthquakes with long return periods. however, according to other authors (costa, 2003; pieri & groppi, 1981; cassano et al., 1986; galadini et al., 2012; galli et al., 2012), the compressive tectonics of the monferrato front ended in the lower or middle pleistocene. in order to verify which of the two hypotheses is more reliable, a detailed study (giraudi, 2014) has already been conducted on the evolution of the vercelli plain, below which the central portion of the monferrato front is present. the data have indicated that the compressive tectonics could have ended before 280-300 ka bp, probably around 400 ka bp, but that tectonic movements, related to structures transversal to the front, probably lasted until the late-holocene. the present paper is intended to highlight the evolution of the plain lying on the eastern portion of the monferrato thrust front (fig. 1), in order to identify and provide evidence of recent tectonic deformations and to check whether tectonic mobility is comparable to that of the vercelli plain. the investigated area is located south of the po river between casale monferrato and the area se of valenza and lies almost entirely between the buried monferrato thrust fronts, to the north, and the monferrato hills to the south. the presence of some large terraces makes the plain of the study area markedly different from the plain lying on the northern slope of the westernmost monferrato-turin hills system. the geomorphological and geological characteristics of the casale monferrato-valenza area, therefore, may have been conditioned by a different tectonic mobility. for this reason, the geological structure of the tertiary bedrock lying below the quaternary cover and some peculiar geomorphological and geological features of the eastern monferrato hills are presented and discussed before the data on quaternary sediments. the interpretation of the evolution of the plain reveals quaternary tectonic deformations, related to the activity of fronts, which are difficult to prove in the monferrato hills because the outcrops are very scarce and of poor quality. 2. geological characteristics of the bedrock the monferrato, together with the turin hills, represents the northernmost part of the apennines and is formed by folded marine tertiary formations. the monferrato hills overlie the plio-quaternary thrust belt separating the tertiary piedmont basin from the mesozoic and cenozoic succession underlying the fluvial po plain (fig. 1). to the north of the monferrato, the po plain corresponds to a foredeep developed as a result of the propagation of north-verging tectonic fronts located on the southern side. according to dela pierre et al. (1995) the po plain foredeep was subject, until the quaternary, to subsidence which reflects the deformation of the front of the apennine thrust belt. the sedimentary sequences lying south of the turin and monferrato hills were deposited inside piggyback basins (irace et al., 2009; mosca et al., 2010). south of the study area, a deep piggyback basin was formed around alessandria. 2.1. stratigraphy and tectonics of the tertiary sediments forming the bedrock of the plain and the isolated hills based on bibliographic data the bedrock lying below the fluvial sediments of the plain, i.e. the sediments that form the buried monferrato thrust front, consists of the same tertiary marine sediments (braga & ragni,1969; corsi et al., 1969) that form the adjacent hills and outcrop in the three isolated hills of occimiano (rio), mirabello (rim), and pomaro-montevalenza (rip). some seismic sections (corsi et al., 1969; montrasio et al.,1969; pieri & groppi, 1981; enel, 1984; cassano et al., 1986) indicate the position of the monferrato thrust fronts buried below the quaternary deposits (fig. 2). the northernmost and oldest front was active during the lower pliocene while others are known to have been active also during the quaternary (enel, 1984). the northernmost front is always placed beyond the po river, that is, outside the study area, except in a small stretch. one of the seismic sections (corsi et al., 1969) shows the presence of a buried (thrust?) fault near occimiano (occimiano fault, fo in fig. 2), linked to the structures of the front. costa (2003) suggests that in the subsurface of the plain of the area studied there is also a sw-ne trending transcurrent or transpressive fault crossing the monferrato front (giarole fault, fg in fig. 2). cassano et al. (1986) show, in their section n. 4, a syncline (called villabella syncline in the present paper, vs in fig. 2) involving tertiary and quaternary sediments lying in the area between the rip and the monferrato hills. the syncline is also proved by the geological structure of the rip, which forms its northern margin (casnedi, 1975), and by the late messinian-early pliocene (?) “conglomerati di cassano spinola” sediments, outcropping on the slope of the valenza plateau at castel menada (ne of valenza; fig. 2), which are part of the southern margin. the studies reported in enel (1984) exclude that the sediments exposed at the base of the escarpment of the valenza plateau, at least from castel menada eastwards, are marine, as supposed in previous papers (martinis, 1954; corsi et al., 1969) but suggest that they are continental and can be correlated to the villafranchian succession. the bedrock of the isolated hills located west and east of the giarole fault is made up of different sediments (corsi et al., 1969). the isolated hills rio and rim, located to the west of the fault, are formed by pliocene marine sediments while the isolated hill rip, located to the east, consists, according to casnedi (1975), of tortonian, messinian and pliocene sediments. the area where pliocene and messinian deposits outcrop at the se slope of the rip is very small and cannot be represented at the scale of fig. 2. from subsurface data, reported in the structural model of italy (bigi et al., 1990), it is possible to estimate the depth of the bottom of the pliocene in the area between the hills of the eastern monferrato and the po river. fig. 3 shows the contour lines of the depth of the pliocene base, modified according to surface data and the interpretation in section 4 of cassano et al. (1986) showing that the pliocene is lacking in the area just 72 giraud c. fig. 1 geological sketch of the monferrato-turin hills and depth of the base of the pliocene (redrawn from dela pierre et al., 2003a). north and ne of the rip. the base of the pliocene reaches a depth of about 3000 m north of the outermost and older thrust front, while the depth slightly exceeds 500 m south of the front. the contour lines reported by bigi et al. (1990) show that the pliocene base is deeper in correspondence with the axis of the villabella syncline and that the axis trends nw-se and w-e. the contour lines assume a sw-ne direction in correspondence with the sw-ne trending giarole fault, which crosses the monferrato front. 2.1.1. extended tectonic interpretation based on the contour lines of the base of the pliocene the trend of the contour lines of the pliocene base (fig. 3) can be interpreted in order to hypothesize the presence of other buried structures. as reported above, the contour lines evidence the thrust fronts, the trends of the villabella syncline and of the giarole fault. it follows that the contour lines showing a depression of the pliocene base indicate the presence of synclines or tectonic troughs, while the contour lines crossing the monferrato front could suggest the presence of faults. near casale monferrato and ne of the rip, the contour lines of the depth of the pliocene base are 73 quaternary evolution of the casale monferrato-valenza plain fig. 2 geological map of the central-eastern monferrato and surrounding plains (modified from: montrasio et al.,1969; corsi et al.,1969). the fronts drawn in the figure are reported in montrasio et al. (1969), corsi et al. (1969), pieri and groppi (1981), enel (1984), cassano et al. (1986). roughly parallel to the hillside and to the thrust front, while in the intermediate area they assume a transversal direction (fig. 3) and indicate the presence of a depression, a syncline (borgo san martino syncline, sbsm in fig. 3) with the axis oriented from sw to ne. the borgo san martino syncline is transversal to the villabella syncline (fig. 3). the eastern edge of the borgo san martino syncline, in position and direction, coincides with the sw-ne trending giarole fault. the western edge of the syncline, which is parallel to the eastern one, could suggest the presence of another fault (roncaglia fault, fr in fig. 3). it cannot be excluded that the tectonic depression called borgo san martino syncline was a trough bounded by the faults trending sw ne. the giarole fault acts as a boundary between the synclines trending sw-ne and nw-se. the change in the direction of the tectonic structures occurring in correspondence with the giarole fault confirms the importance of the fault for the tectonic evolution of the area. the nw-se trend of the isobaths in correspondence with the occimiano fault suggests that south of the (thrust?) fault the base of the pliocene is uplifted. the features of the pliocene base near the occimiano fault are quite similar to those observed near the northernmost thrust fronts (fig. 3) and suggest that the fault is a stretch of a buried front. east of the rip (fig. 3), the contour lines of the depth of the pliocene base assume a direction transversal to the thrust fronts, as in correspondence to the giarole fault: therefore the n-s contour lines may evidence a fault trending n-s (valenza fault). 2.1.2. the “platea” below the po plain fluvial sediments in the plain between casale monferrato and valenza, as in all the whole plain surrounding the northern monferrato, there are areas where the tertiary sediments lie less than 20 m below the ground surface (fig. 3). in those areas, the top of the tertiary bedrock, erosional in origin and shaped by rivers, is represented by a nearly flat surface, or by different surfaces located at altitudes slightly different, known in the italian literature as "platea" (enel, 1984b; carraro et al., 1995; dela pierre et al., 2003a,b; festa et al., 2009). quaternary fluvial sediments of various ages overlie the platea. the stratigraphic data from boreholes indicate the extent of the platea, already partly represented in enel (1984), dela pierre at al. (2003a,b), arpa piemonte (2014) and giraudi (2014). figure 3 shows that north of the monferrato, but also around the turin hills (festa et al., 2009), the limits of the platea are always next to the thrust fronts or structures crossing them. outside the platea, the quaternary fluvial and fluvioglacial sediments become thicker, indicating that the platea edge is a boundary between areas that have undergone a different evolution. hence, during the quaternary, the area outside the platea was mainly in subsidence, as demonstrated by studies on the westernmost plain (enel, 1984a; dela pierre at al., 2003a,b; giraudi, 74 fig. 3 tertiary bedrock covered by quaternary fluvial sediments less than 20 m thick (platea), contour lines of the base of the pliocene, and tectonic structures north of the central and eastern monferrato hills. giraud c. 2014). fig. 3 shows that in the west, from crescentino to tricerro, the platea ends near the thrust front, reaching a distance of 10 km from the northern monferrato hillslope. the eastern margin of the platea lies on the salera line, a complex n-s striking tectonic structure, according to giraudi (2014). in the area of casale monferrato and south of balzola, the platea ends almost in coincidence with a trust front very close to the monferrato hillslope. in the occimiano-giarole area the northern margin of the platea lies on the occimiano fault, while, from giarole to bassignana, the platea ends near the thrust front north of the rip, narrowing toward bassignana. in the area se of casale monferrato, occimiano and giarole, the margins of the platea are also oriented sw-ne, transversal to the direction of the fronts. near giarole, the position of the margin of the platea almost coincides with the ne part of the sw-ne trending giarole fault. 2.1.3. hyphotheses regarding the tectonic origin of the platea boundaries the data reported above show that the platea edge is a boundary between areas that have undergone a different evolution, and that the area outside the platea is mainly in subsidence. moreover, some stretches of the platea edge lie near some buried thrust fronts and correspond to the occimiano and giarole faults. se of casale monferrato, the margin of the platea is parallel to that corresponding to the giarole fault, and lies on the sw-ne striking roncaglia fault, hypothesized using the contour lines of the base of the pliocene. the coincidence between two different data allows us to consider the presence of the roncaglia fault to be very likely. the distance between the outer edge of the platea and the hillslope (fig. 3) indicates a great difference between the areas separated by the giarole fault: to the east of the fault the platea expands strongly northwards beyond the po river, seven kilometres further than in the western area. the activity of the fault, therefore, had an important role in determining the platea boundary. the position of the boundary may have been produced by left-slip displacements along the giarole fault or by the uplift of the area east of the fault. transcurrent or oblique movements may indicate a continuation, even in the quaternary, of the faults activity linked to the northward migration of the front of the monferrato suggested by costa (2003). west of the roncaglia fault, the platea expands and its limit is about 5 km further north than in the area of the isolated hills rio and rim. the position of the edge of the platea is opposite to that produced by the giarole fault. the roncaglia fault could have been characterized by a right-slip activity (fig. 3) and have been involved in the northward migration of the thrust front or could have produced the uplift of the area lying nw of the fault. the giarole and roncaglia faults, thus, coincide with margins of the platea transversal to the direction of the fronts. based on this datum, the correspondence between some stretches of the margin and other buried tectonic structures can be hypothesized. also near the nw margin of the rio, the edge of the platea, west of the rotaldo stream, is about 1 km further south. this suggest the possible presence of a fault directed sw-ne near the streambed corresponding to the rotaldo fault (fdr in fig. 3). given the limited shift, it could be a fault with a left-slip component or a normal fault. overall, the subsurface data indicate that the structures which affect the margins of the platea were active during the quaternary and that the whole area external to the platea has undergone a certain degree of subsidence. 2.2. morphology, stratigraphy and tectonics of the eastern monferrato hills some observations useful to understand and confirm the hypothesized geological structures buried below the quaternary sediments derive from the interpretation of the morphology and the known geological structure of the adjacent hills (fig. 2). the divide between the po and tanaro river basins is arcuate in shape, first running from wsw to ene, then approximately w-e and finally nw-se, and is subparallel to the trend of the boundary between the alessandria plain and the southern slope of the hills. however, the general trend of the divide undergoes noticeable local variations (fig. 2): there are in fact stretches with a sw-ne direction in the west, and a nnw-sse direction in the east. the directions of the valleys of the rotaldo and grana streams are quite peculiar (fig. 2). the high valleys are directed nw-se and wnw-ese, but the rotaldo valley, north of vignale, changes direction toward ne, the same occurs at the grana valley sw of vignale and west of lu. the geological features of the eastern monferrato hills are reported in bonsignore et al. (1969), braga & ragni (1969), corsi et al. (1969) and montrasio et al. (1969). the sediments that form the hills ranging from ssw to w of mirabello (fig. 2) include almost all the formations recognized in the monferrato hills and their age is between upper cretaceous and pliocene. the oldest sediments are attributed to the ligurian units. it should be noted that the scarcity of outcrops in the hills allowed the authors to recognize the general geological features but hardly to analyze in detail the characteristics of the structures. according to braga & ragni (1969) in the lower grana valley there is a fault (the grana fault in the present paper, fdg in fig. 2) having the same direction as the valley (sw-ne), and therefore transversal to the main structures of the monferrato area. on the northern hillslope, between terruggia and the rotaldo stream, the pliocene sediments always overlie the messinian ones, and are folded by synclines having axes trending sw-ne (castello di lignano synclinescl in fig. 4) and nw-se (ponara and terruggia synclines, srp and st in fig. 4). between the rotaldo and grana valleys the pliocene sediments overlap on pre-messinian sediments (fig. 4), their eastern boundary lies near the grana fault and the western one close to the possible southern pro 75 quaternary evolution of the casale monferrato-valenza plain 76 fig. 4 geological map of the po plain, monferrato hills and northern alessandria basin. the geological structures active during the quaternary lie from the po plain to the southern boundary of the monferrato hills, probably reaching the northern alessandria basin. giraud c. longation of the rotaldo fault (fig. 4). the hills to the east of the grana valley (south of mirabello) and as far as the area of valenza are composed mostly of miocene sediments (mainly tortonian and messinian) and there are no outcropping pliocene marine sediments on the northern slopes. in addition, a seismic section through the area, reported in cassano et al. (1986), highlights the lack, even in the subsoil, of the ligurian units outcropping a few kilometres to the west (fig. 4). starting from south of valenza, the hills are formed by eocene to miocene sediments affected by diapirs and by messinian and pliocene marine sediments. the pliocene sediments are lacking on the northern hillslope. according to enel (1984b), nw of rivarone lie also calcareous marls pertaining to the ligurian units. overall, there is a clear difference in the stratigraphy of the areas located sw and w of mirabello, those located from se of mirabello and valenza, and from valenza to rivarone, and the boundaries lie on the possible south-western prolongation of the giarole fault, and southern prolongation of the valenza fault. it can be observed that the stratigraphy of the sediments forming the easternmost hills appears similar to that of the western hills, while the stratigraphic anomaly is restricted to the area between the southern prolongation of the giarole and valenza faults. west of the possible prolongation of the giarole fault a stratigraphic anomaly can be observed also in the southern slope of the monferrato hills, between the area south of vignale and lu. the pliocene sediments outcropping on this stretch of hills overlie pre-messinian sediments (fig. 4), a case almost unique in the whole southern slope of the monferrato and turin hills. only near castelnuovo don bosco and passeranomarmorito, at the southern boundary of rio freddo deformation zone (dela pierre et al., 2003a; festa et al., 2009) a similar contact was observed. the eastern limit of the area of anomalous contact between pliocene and pre-messinian sediments lies on the possible prolongation of the giarole fault while the western one is on the possible southern prolongation of the rotaldo fault. a deviation of the divide of the rotaldo and the change in the direction of the grana and rotaldo valleys, occur in the possible southern prolongation of the rotaldo fault, north and south of vignale. between conzano and lu, according to corsi et al. (1969) and montrasio et al. (1969) the axes of the anticlines, oriented wnw-ese, are folded, assuming a sw-ne direction in correspondence with the possible sw prolongation of the (left transcurrent) giarole fault (fig. 4). to the west of the possible southern prolongation of the giarole fault, the tortonian and messinian sediments surround to the south the oldest sediments that form the monferrato and dip towards the alessandria basin, but east of the possible prolongation of the fault they advance considerably northwards forming also the northern slope of the hills and the southern slope of the rip (fig. 4). east of the possible prolongation of the giarole fault until the area south of valenza, the tortonian and messinian sediments form an anticline with an axis corresponding to the highest part of the hills. in no other sector of the monferrato or the turin hills do late miocene sediments form the highest hills. the anticline has a wsw-ene trend, but to the east it is oriented wnwese. the anticline lying north of montecastello is formed by diapiric structures aligned nnw-sse. this anticline therefore forms a nearly symmetrical structure with respect to the anticlines lying near lu (fig. 4). near the montecastello anticline, the divide between the po and tanaro basins undergoes some noticeable local variations assuming nnw-sse directions. on the northern prolongation of this anticline lies the hypothesized valenza fault having a similar direction. 2.2.1. tectonic interpretation of the geological and morphological features the joint interpretation of the morphological and geological features of the eastern monferrato hills suggests that the hills are interested by the same kind of deformations affecting also the bedrock of the po plain. as a matter of fact the anomalous contacts between pliocene and pre-messinian sediments, the distribution of the tortonian and messinian sediments, the presence or absence of the ligurian units, the folded anticlines, the sudden deviations in the divide and the change in the direction of the grana valley, are consistent with a left-slip displacement produced by tectonic deformations lying on the southern prolongation of the rotaldo and giarole faults and with one or more rightslip faults or plastic deformations lying on the southern prolongation of the valenza fault. but, according to corsi et al. (1969) and montrasio et al. (1969) there are not important surficial faults that produce the tectonic deformations and therefore we can assume the presence in the hills of plastic deformations induced by deep tectonic structures. the giarole fault, and the tectonic deformations lying on its sw prolongation, stretches from the monferrato thrust front ne of the rip to the boundary between the hills and the alessandria basin: acting as a boundary between geologically different areas both below the plain and on the hills it can be considered the most important tectonic structure affecting the area. the complexity of the tectonic deformations observed in this area suggests the presence of a deformation zone (giarole-lu deformation zone, gldf in fig. 4). also the tectonic structure formed by the valenza fault and the associated tectonic deformations lying south of it reaches the boundary between the hills and the alessandria plain and suggests the presence of a deformation zone (valenza deformation zone, vdz in fig. 4). the rotaldo fault probably is a normal fault that starts near the occimiano (thrust) fault, continues toward sw, and reaches the southern slope of the monferrato hills. changes in the axes of the synclines similar to those occurring in correspondence to the giarole fault occur also on a possible southern prolongation of the sw-ne trending roncaglia fault (fig. 4). in fact, the axis of the ponara syncline (lying west of the fault) is 77 quaternary evolution of the casale monferrato-valenza plain oriented wnw-ese, while the axis of the castello di lignana syncline (east of the fault) is sw-ne. the eastern monferrato is not the only place in the monferrato-turin hills where the southern slope is affected by deformation zones transverse to the hills: also the t. traversola deformation zone, shows a strike slip nature (forno et al., 2015; gattiglio et al., 2015). 3. morphological framework and quaternary stratigraphy of the plain between casale monferrato and valenza general indications on the quaternary cover of the study area are shown by anfossi et al. (1969), bonsignore et al. (1969), braga & ragni (1969) and montrasio et al. (1969). during the 80’s of the twentieth century (enel, 1984), the area was also included in a morphostratigrafic study conducted during the research for the seismotectonic characterization of nuclear sites, and the results are partly discussed in carraro (2012). the main streams flowing in the area investigated are the rotaldo and its tributary the ponara, and the grana, which flow into the po river. in the rotaldo and grana valleys, clear remains of fluvial deposits different than those that form the valley floor have not been found. outside the valleys, the streams cut into terraces lying at different altitudes. the presence of some large terraces makes the plain north of the eastern monferrato hills markedly different from the plain lying at the northern slope of the westernmost monferrato-turin hills system (fig. 2). moreover in the area covered by this study, the po lies at some distance from the hills while from turin to casale monferrato it always flows near the foot of the hills. the presence of the isolated hills at the boundary between the belt of high terraces and the po plain is also exceptional. the only other isolated hill to the north of the monferrato area is located further west, near trino. these features thus make the plain to the north of the eastern monferrato peculiar compared with the westernmost plain. the same conclusion was reached observing the stratigraphy and the tectonics of the bedrock. the morphology of the plain makes it possible to identify three areas with different characteristics: the isolated hills, the high terraces, and the lower terraces of the po river. 3.1. the isolated hills the isolated hills of pomaro-montevalenza (rip), mirabello (rim) and occimiano (rio) are small hilly areas, consisting mainly of tertiary sediments, isolated among the fluvial terraces (fig. 2; 4). the isolated pomaro-montevalenza hill (rip) the rip is a hill, elongated in a nw-se direction for about 3.5 km having a width of 1.5 km, reaching an altitude of 165-170 m a.s.l., that is ca. 60-70 m above the surrounding terraced plain. it is located on the northern edge of the villabella syncline (fig. 4) and consists mainly of late miocene marls and clay, of marine origin (casnedi, 1975). the rip is divided into two parts by a valley that separates the hill of pomaro from that of montevalenza (fig. 5 b). the nw area (pomaro) has steep slopes having a nw, sw, se and ne orientation, and a nearly flat top, located at altitudes between 150 and 155 m, and is eroded by small valleys. the valleys are present only in the se and southern slopes. in the summit area some patches of very weathered silty colluvial sediments were found (colour index up to 2.5 yr of the munsell soil colour chart-mscc). in the colluvia, sand and small pebbles have also been observed, and their lithology suggests an alpine origin. in particular the pebbles are lithologically similar to the gravel outcropping in the cerrina valley (enel, 1984), outside of the study area, described by giraudi (1981), carraro et al. (1995), giraudi et al. (2003), dela pierre et al. (2003a,b). the heterogeneous lithology of the deposits, their variable grain size and the presence of a fraction of gravel of alpine origin, indicate that the colluvia derive from sediment of fluvial origin. the nearly flat summit is, therefore, the remnant of a terraced surface, originally shaped by a stream, for which there are no homologous terraces either to the north or on the monferrato hill slope. the part of the rip on which montevalenza lies reaches 165-170 m, and is extremely asymmetrical since it is limited by very steep slopes to the nw, ne and east, while it slopes gently towards the south. the stream network is developed only on the southern slope. the quaternary deposits identified are colluvia consisting of weathered silt, with a colour index reaching 2.5 yr mscc. the silts are present however only at altitudes below 155-150 m, corresponding to the altitude of the top of the pomaro hill. it is possible that at the time of the shaping of the flat top of the pomaro hill the highest part of the montevalenza area was already a small isolated hill. the isolated mirabello hill (rim) the rim, formed by pliocene sediments (corsi et al., 1969), is elongated for about 1.5 km in a w-e direction, about 0.6 km wide, and divided into two parts by a small valley. the largest slopes run w-e, and are exposed to the south and north (fig. 5 a). the western part of the rim reaches a height of 161 m while the eastern one reaches 155 m. some thin patches of weathered fluvial and colluvial silt, whose colour index reaches 2.5 yr mscc, lie on top of the hill. also the surface of the rim could correspond to the remains of a terrace which has no homologous terrace on the monferrato hillslope. according to corsi et al. (1969), the surface of the rim corresponds to the top of the oldest terrace in this area (see below) dated at the mindel. the isolated occimiano hill (rio) the rio is an approximately rectangular hilly area, consisting of pliocene marine sediments, elongated for about 3.5 km in a ne-sw direction, about 1.5 km wide, which reaches a maximum height of 166 m, ca. 25-40 m above the surrounding terraced plain (fig. 5 a). the slopes shaped by the rotaldo and grana 78 giraud c. streams corresponding to the longer sides of the rectangle, are oriented sw-ne like the axis of the castello di lignano and borgo san martino synclines, and the nw slope is parallel and lies near the rotaldo fault (fig. 4); the eastern one is parallel to the grana fault and the ne one is parallel to the occimiano fault. the hill is eroded by small valleys directed mostly towards nw and se, but also to the s and nne, due to a centrifugal drainage pattern. near the summit of the hill discontinuous outcrops of very weathered silty sediments have been observed (colour index up to 2.5 yr mscc). the silt sometimes contains a gravel component and the lithology of the gravel is similar to that of the fluvial sediments of the cerrina valley, alpine in origin (enel, 1984). artefacts from the lower paleolithic were collected towards the base of one of these silty deposits (giraudi & venturino, 1983). some colluvial patches with a different degree of weathering and colour index between 2.5 yr and 10 yr mscc have been observed on the slopes of the rio. the redder colluvia have the same grain size as the summit colluvia having the same degree of weathering. the altitude of the various ridges is fairly constant (between about 160 and 165 m) and indicates that the top of the rio was originally almost flat. if we consider also the fluvial origin of the gravel we can agree with corsi et al. (1969) and braga & ragni (1969) that the summit of the rio is a remnant of a mainly erosional fluvial terrace. depending on the summit altitude, the terrace could have no homologous terrace either north or south. the survey of some artificial exposures has also shown a sequence of colluvial phases (fig. 6). the oldest colluvia, up to 3.5-4 m thick, overlying a nearly flat erosion surface lying at an altitude of approximately 130 m, are very weathered, with a colour index of 2.5-5 yr mscc. an intermediate colluvial layer, with a colour index of 7.5 yr mscc, rests on the older sediments. some colluvial sediments that are little weathered (colour index 10 yr mscc) overlie the intermediate layer. at the foot of the slope another sequence of colluvia was exposed. the oldest colluvia, about 3 m thick, with a colour index of 5yr mscc, lie on an erosional surface about 6 m below the valley floor: they are covered by a second colluvial deposit with a colour index of 7.5 yr mscc, on which lie the last, poorly weathered colluvia. the sequence of erosions and sedimentation of the colluvia, enables us to recognize the evolution of the slope. the stratigraphy indicates that, after the sedimentation of the fluvial deposits preserved at the top of the hill, when the weathering was already very strong (2.5yr mscc), a phase of erosion began which carved up the slope to an altitude of about 130 m a.s.l.. the erosion was followed by the emplacement of the colluvium. later, at the top of the rip, a new paedogenesis took place which produced a soil with a colour index of 5 yr mscc. the soil in turn was colluviated after the 79 fig. 5 map of the terraces lying north of the eastern monferrato hills. 1 monferrato hills; 2 fluvial and lacustrine unit exposures; 3 summits of the rio, rim and rip isolated hills; 4 s1 terrace; 5 s2 terrace (a: covered by aeolian sediments; b: covered by flat fluvial fans); 6 terrace s3; 7 studied colluvial series; 8 river diversion; 9 anomaly in the hillslope-terrace s2 boundary; 10 villafranchian succession outcropping in the s2 terrace scarp; 11 a-a’, b-b’, c-c’, d-d’ cross sections through the terraces s1 and s2, and the top of the rio reported in fig. 8; 12 boundary between hills and terraces. quaternary evolution of the casale monferrato-valenza plain erosion of the slope, produced by the presence of a small stream at its foot. later a soil with a colour index of 7.5 yr mscc evolved; this was eroded and colluviated, and the new colluvium covered the older one. finally the last soil, with a colour index of 10 yr mscc, developed and was later eroded producing the colluvia of the same colour. it is evident that the phase of erosion of the base of the slope (fig. 6) decreased or ceased after the sedimentation of colluvium with a colour index of 5 yr mscc and that the later phases of erosion and aggradation were weaker. 3.2. the quaternary sediments between the eastern monferrato hills and the po river the sequence of quaternary sediments lying between the northern edge of the eastern monferrato area and the po river, in spite of the information derived from water wells, is rather difficult to study and date mainly because of the scarcity of exposures and sections that can provide adequate stratigraphic and chronological data. the sediments will be described starting from the oldest. fluvial-lacustrine unit the poorly exposed sediments that form this unit have been identified in two places: near the castello di lignano and in the area of coppi (the ponara valley fig. 5a). near the castello di lignano, about 140 m a.s.l., clay, silt and sand of fluvial-lacustrine origin, 5-6 m thick, have been identified, surrounded by pliocene marine sediments (sabbie di valleandona, according to montrasio et al.,1969). given the poor quality of the exposure, the nature of the basal surface is not clear but, since the pliocene sediments lie at higher altitudes, it is likely that the base of the fluvial-lacustrine sediments was carved in the underlying marine deposits. the mineralogical composition of the sands is similar to that of the fluvial deposits of the lower and middle pleistocene of the cerrina valley (quartzites of various colours, gneiss and mica schist, fine-grained metabasites) studied by giraudi (1981), enel (1984), giraudi et al. (2001) and dela pierre et al. (2003b). the sediments described above are covered, with a clear erosional contact, by weathered sandy silt, coloured 5 yr mscc, about 1-1.5 m thick. in the area of coppi, at an altitude of about 160170 m, in the ploughed ground gravelly sand is exposed, whose lithology is very similar to that of the sand found near the castello di lignano. also in this area the bedrock is formed of pliocene marine sediments. the fluvial-lacustrine and fluvial sediments of the two areas are isolated and there is no direct dating. however, the lithological composition (quartzites of various colours, gneiss and micaschist, limestone, mediumfine grained calcarenite) shows similarities to fluvial sediments of alpine origin observed in the cerrina valley, whose sedimentation began about 1 ma ago (giraudi et al., 2003). we can therefore assume (in accordance with enel, 1984; carraro et al., 1995) that the sediments were deposited by the same river that flowed through the cerrina valley and continued eastwards reaching the area under consideration. sedimentation would have ceased at the time of the deviation to the north of the river, which occurred in the cerrina valley, around 600 ka bp (dela pierre et al., 2003b). it follows that the sediments of the fluvial unit may be between about 1 and 0.6 ma old. the terrace s1 and its sedimentary succession the terrace s1, recognized in the ponara valley and on the left side of the rotaldo valley (fig. 4; 5a), is the oldest (corsi et al., 1969), heavily eroded and formed by relict surfaces preserved as narrow and elongated ridges covered by strongly weathered sediments. in the ponara valley the surface of the terrace s1 dips from north to south and from nw to se, that is towards the axis of the rio ponara syncline, while on the left side of the rotaldo valley it dips from w to e and from sw to ne, that is, towards the axis of the castello di lignano and borgo san martino synclines. the remnants of the terrace lie at altitudes between about 190 and 135 -140 m a.s.l., ca. 3040 m above the valley floor of the rotaldo and ponara streams. the sediments that form the surface of the terrace s1 consist mostly of weathered silt, with a colour index up to 2.5 yr mscc. horizons of fine gravel are sometimes interbedded in the silt, their lithology being similar to that forming the fluvial-lacustrine unit but mixed with clasts of local origin. the sediments are fluvial and linked to a non-local river, according to corsi et al. (1969). it can be assumed, therefore, that the clasts of alpine origin derive from the erosion of the deposits of the older sedimentary unit. the estimated thickness of the sediments is always less than 2-3 m. colluvia with the same lithology as the fluvial sediments are also present on the terrace scarps. according to corsi et al. (1969) and braga & ragni (1969), fluvial sediments, weathered into a typical “ferretto", are covered by brick-red coloured loess a few metres thick. this results from outcrops no longer visible and indicates the presence of aeolian sediments much more weathered than those recognized further east (see below) described by sacco (1889), enel (1984) and corsi et al. (1969). the heavily weathered loess may be correlated to that found on the higher surfaces of the isolated trino hill (rit in fig. 3), reported by the gruppo di studio del quaternario padanogsqp (1976) and enel (1984), assigned to the mis 8 by giraudi (2014) 80 fig. 6 colluvial deposits on the rio nw slope. giraud c. on the basis of the stratigraphy. therefore, sediments and soils similar to those found on the summit of the isolated hills rio, rim and rip lie on the top of the terrace s1. the altitude of the eastern remnants of the s1 surface is slightly less than that of the rio summit. according to corsi et al. (1969), the sediments of s1 correspond to those found at the top of the isolated hills rio and rim. the age of the fluvial sediments, that date back to the mindel according to corsi et al. (1969), must therefore be more recent than the fluvial-lacustrine unit, dated between about 1000 and 600 ka bp, and older than the weathered loess (mis 8, dated between about 300 and 270 ka bp). according to arduino et al. (1984), soils with a colour index corresponding to 2.5 yr mscc may have developed from the early middle pleistocene. the terrace s2 and its sedimentary succession the terrace s2 is significantly lower than s1 and is divided into three parts (fig. 4; 5), being cut crosswise by the rotaldo and grana streams. the first area where s2 is present (fig. 4; 5a) corresponds to the left side of the ponara and rotaldo valleys. the surface of the terrace dips from sw to ne, from about 160 to 140 m a.s.l., and must have been shaped by rivers that flowed in that direction. on the surface of the s2 terrace some quite extensive patches of weathered fluvial silts are preserved, with a colour index of 5yr mscc, less than 1.5 m in thickness. according to arduino et al. (1994) soils with a colour index of 5 yr mscc would have developed during the middle pleistocene. the second area is between the rio and the hillside, limited to nw and se by the rotaldo and grana streams (fig. 4; 5a). the position and dip of the surface of the terrace suggest that s2 has been shaped by the rotaldo and by smaller hill streams. the altitude of the s2 surface is between 150 and 135 m a.s.l. the surface of the terrace s2 in this area is mainly eroded by streams that drain towards the ne and then, after forming an elbow, flow towards ese. there is also a remnant of the s2 terrace on the western side of the rio indicating that, in the course of the shaping of s2, the rotaldo stream changed direction and began to flow n. the third area where the terrace s2 is present, the largest one, is located east of the grana stream, and corresponds to the area known as the valenza plateau. the plateau is strongly dismembered as a result of the incisions of streams active after its shaping. about the streams, we can distinguish the longitudinal ones (with a bed extending in the direction of elongation of the terrace s2) and the transversal ones. the longitudinal streams form the collectors into which flow the transversal streams. they have approximately a wsw-ene direction in the area south of rim, w-e in the area south of the rip, and then wsw-ene from the rip to valenza. south of the rip some stretches of longitudinal streams overlap almost exactly the axis of the villabella syncline (fig. 4). the transversal streams that cut the terrace from the area south of the rim to the area to the sw of the rip, flow nne and ne, while from the area south of the rip to valenza, they flow n and nnw. the streams on the rip slopes, flow from nnw to sse. east of valenza the small valleys are generally directed ne and nne. among the streams cutting the valenza plateau, the longest one is the rio anda (fig. 4; 5). it flows in a small valley which, sw of the rip, has a flat bottom formed by sandy silty sediments, while starting from s of the rip, it becomes very narrow and deep, as all the streams in the area. overall, the surface of the terrace s2, between the altitudes of 145 and 90 m, indicates a general slope from west to east and towards the northern quadrants. the greater height reached by the surface s2 at the foot of the hills is mainly due to the presence of a belt of flat fluvial fans and a layer of colluvial deposits that stretches from the grana valley to the eastern end of the plateau. one of the most extensive fluvial fans is located on the right bank at the mouth of the grana valley, showing that this stream also took part in the shaping of s2 (fig. 5). however, the presence of s2 at the western and northern edges of the rim and on the right side of the grana stream indicates that, during the shaping of the terrace, the stream changed its bed, heading n, bypassing the rim and flowing eastwards reaching the longitudinal collector, oriented wnw-ese, lying south of the rip. overall, the sector of s2 corresponding to the valenza plateau was therefore shaped by the grana and other smaller streams, but it is possible that, before a diversion, even the rotaldo and its tributary ponara flowed eastwards forming a much longer collector. the boundary between the s2 terrace and the hillslope shows some peculiarity. at the mouth of the rotaldo and grana valleys and of the valley of a minor stream, south of the rim (fig. 5a), in the eastern side of the valleys the boundary between s2 and the hillslope is located 800, 1000 and 500 m, respectively, further north compared to the western side. instead, starting from the area se of the rim till the eastern end of the valenza plateau (fig. 5b), in correspondence with some small valleys, the boundary between surface s2 and the hillside is located, west of the streams, 500 or 600 m further north if compared to the east. hence the position of the boundary between the surface s2 and the hillslope does not seem random; the peculiarities of the boundary observed s and se of the rim, lie in the giarole-lu deformation zone (fig. 4), while those lying near valenza are located in the valenza deformation zone. the sediments that form the terrace s2 consist, from top to bottom, of: coarse yellowish quartz sands of aeolian origin, described by corsi et al. (1969) and enel (1984), which form some small dunes less than 2-3 m high, present at the ne margin of the terrace. the shape of the dunes is no longer visible, probably because of the fields having been levelled for agriculture. the sands lie on the underlying sediments by means of an erosional contact. similar dunes have been reported lying on the fluvial sediments to the east of the po river, a few kilometres from the valenza plateau, and their age is considered as upper pleistocene 81 quaternary evolution of the casale monferrato-valenza plain corsi et al. (1969) although it could reach the holocene (enel, 1984). unstratified silt, close to 2 m thick, already recognized as loess by sacco (1889), which can be divided into two horizons between which there is a fairly sharp boundary (enel, 1984). the more surficial horizon, characterized by porosity and vertical prismatic fissures, is weathered by a soil with an average colour index of 10 yr mscc. in the darker lower horizon, the prismatic structure is lacking, and there are carbonate concretions towards the base. although there are no elements for a direct dating of these sediments, the loess of the valenza plateau can be correlated to that widespread in piedmont in the following areas: the turin hills, the poirino plateau, the rivoli-avigliana moraine amphitheatre, the isolated trino hill, the area near novi ligure, and the cerrina valley (forno, 1979; biancotti & cortemiglia, 1981; giraudi et al., 2003; festa et al., 2009; balestro et al., 2009). the loess is generally attributed to the late pleistocene. on the isolated trino hill (giraudi, 2014) loess with the same features contains some upper paleolithic artifacts while, in the cerrina valley, it contains mousterian artifacts that can be dated to the very late middle pleistocene or to the upper pleistocene. we can therefore assume an upper pleistocene age for the loess of the valenza plateau. silt and sandy silt, from 1.5 to 5 m thick, sometimes containing thin layers of fine gravel at the bottom, of fluvial origin; the lithological composition of the gravel shows that the pebbles have a mixed origin, alpine and local, and that they probably derive also from the reworking of the oldest fluvial sediments. the deposits are weathered and the soil colour index is 7.5 yr mscc. the sediments lie, through an erosion surface, on the tertiary marine and villafranchian succession. having been weathered before the sedimentation of the loess, the fluvial sediments must be significantly older than the aeolian deposits. the greater pedogenesis (5yr mscc colour index) of the sediment lying on s2 in the valley of the ponara and rotaldo streams, where the described loess are lacking, should be connected, according to arduino et al. (1984), to a soil that developed before the end of the middle pleistocene. the fluvial sedimentation in the valenza plateau was followed by a phase of pedogenesis, an erosion phase and finally by the sedimentation of the loess. the evolution of the soil buried by the loess was therefore halted during the upper pleistocene. for this reason, the palaeosol is less evolved than the soil preserved on s2 near the rotaldo stream. it is therefore likely that the fluvial sediments lying on s2 date back to the latest middle pleistocene. the terrace s3 and its sedimentary succession the terrace s3, recognized at the mouth of the rotaldo and grana valleys, is poorly preserved and discontinuous, and its surface lies between 127 and 120 m a.s.l. (fig. 4; 5). no exposures indicate the stratigraphy and facies of the sediments. only observation of the ploughed sediments has allowed us to establish that the top of the terrace is formed of silt, sometimes sandy, weathered by soil with a colour index of 7.5 yr mscc. the sediments of the valley bottoms and the plain south of the po river between the po river and the northern edge of the terraces s1, s2 and isolated hills, is the floodplain to which are connected the valley bottoms of the streams with catchments in the hills. the plain consists, basically, of a main surface (terrace t4) and a set of surfaces located at altitudes very similar to each other (for simplicity grouped under the acronym t5) that correspond to the area shaped in recent times by the po river, and in which abandoned meanders and river beds are clearly visible (fig. 4). the bottoms of the rotaldo and grana valleys are connected with the terrace t4 at the mouth of the valleys, but further downstream the streams cut this surface joining the terrace t5. all the streams that cut the valenza plateau se of the rip are connected to the terrace t5. the morphological and geological features of the terraces, based on a field survey, small artificial exposures, and stratigraphic data from quarries and boreholes, are the following. terrace t4: it forms the largest sector of the area between the po river and the valenza plateau and isolated hills but is not present se of the rip. its altitude ranges from about 120-125 m in the area of casale monferrato, to less than 100 m in the area near the rip. the surface t4 is correlated, according to its altitude, with a terrace lying north of the po river formed by fluvio-glacial deposits, linked to the morainic amphitheatre of ivrea, dated to the late upper pleistocene (montrasio et al., 1969; corsi et al., 1969; giraudi, 2014). the morphology of the terrace and the grain size of the sediments indicate that it has been shaped by the po river. the surface consists of sandy gravel covered by sand and silty sand. it is possible that some of the silty sands that form the surface were deposited by the streams with catchments in the hills, and date back to the holocene. the thickness of gravelly sandy sediments in the subsurface of t4 ranges from less than 10 m in some areas (fig. 4) up to 50-60 m in the area north of the edge of the platea. in the subsurface, two fossil elephant teeth were found which unfortunately do not provide any significant chronological information. in a quarry on the outskirts se of casale monferrato, under the groundwater level, a tooth (right second molar) of e. antiquus was found (determined by v. borselli, pers. comm., 1983, in enel, 1984). the depth is not known, but in the area the thickness of the fluvial sediments is less than 20 m. on the western outskirts of the same town, a few metres below ground level, an upper left molar of e. primigenius (negri, 1884) was instead found in the fluvial sediments. the age of the base of the sediments forming t4 is unknown, but it is very likely that, at least in the area where the sediments are thicker, that is north of the 82 giraud c. edge of the platea, it is considerably older than that of the superficial deposits. the top of the t4 terrace is partially eroded and it is formed by three different surfaces that can be hardly recognized being separated by discontinuous scarplets. se of casale monferrato (fig. 4), there is a flattopped ridge (t4-1), about 2 km long and 500-600 m wide, slightly higher than the t4-2 surface. the ridge is limited by discontinuous very gentle scarps that do not reach one metre in height. in a temporary quarry (enel, 1984) it has been observed that the ridge is formed, at least to a depth of 4 m, by slightly weathered fluvial sandy gravels quite similar to those which form the other sectors of t4. the best preserved portion of the t4 surface (t42) surround the t4-1, but north and south of t4-2 lie surfaces whose altitudes are slightly lower (t4-3n; t43s) (fig. 4). t4-2 is between casale monferrato and borgo san martino-ticineto; it has a nw-se direction and its northern and southern limits, in places, coincide with or are parallel to the buried thrust fronts (fig. 4). a section of the boundary between the t4-2 and t4-3n surfaces corresponds to the northern limit of the buried platea and the width of t4-2 decreases east of the eastern edge of the platea. the boundary between t4-2 and t4-3n is not represented by a real scarp, but just by a hardly noticeable scarplet in the plain having a nearly straight direction. although it is possible that the scarplets in the plain were connected with the erosion of the po river, their morphology is totally different from that of the escarpment, certainly shaped by the po river, that separates t4-3n from the most recent t5 terrace. the latter is, in fact, much more evident and, especially, has been clearly shaped by a meandering river (fig. 4). the erosion of t4-3s is certainly due to the gattola, rotaldo and grana streams. the streams gently eroded t4-2 and deposited surface silty sediments. the southern edge of t4-3s, especially where it reaches the scarp of the terrace s2 (fig. 7), has a curvilinear shape as a consequence of fluvial erosion (fig. 4). the direction of the beds of the gattola and rotaldo streams, now artificially diverted, was from sw to ne, but before they reached the southern edge of the t4-2 surface, they diverged sharply to the se and ese (fig. 4). the mainly silty-sandy deposits of the rotaldo and grana valley bottoms are connected with the t4-3s surface. terrace t5: as noted above, this is formed by a series of low river terraces shaped during the changes of the bed of the po river (fig. 4). in the contiguous vercelli plain and just north of the po river, the sediments that form these terraces contain bronze age, roman and middle age artifacts and remains (tropeano & olive, 1989; giraudi, 1998; giraudi, 2014). therefore, the shaping of t5 took place during the late holocene. from the area of casale monferrato to the rip, the t5 surface develops closely parallel to the current bed of the po river and lies between t4 and a terrace, equivalent to t4, sited n and ne of the po river (fig. 2). only downstream of the rip, where t4 is lacking, does t5 reach the base of the scarp of the valenza plateau and the river flows in an asymmetric position, very close to the scarp. 4. discussion the data presented above will be interpreted and discussed in order to highlight the sedimentary and tectonic evolution of the area during the quaternary. the results will be compared with geodetic data, derived from topographic measurements of precision and gps stations, in order to verify the compatibility between tectonic interpretations and data relating to the ongoing deformation. finally, we will discuss the distribution of the epicentres of earthquakes recorded in the area and the correspondence between epicentres and areas affected by tectonic movements. 4.1. sedimentary and erosive quaternary evolution the data and the interpretations of the succession of phases, erosional, depositional and pedogenetic, enable the evolution of the area between the po and the eastern monferrato hills to be outlined. it should first be pointed out that, apart from the coarse fluvial sediments of the po plain, on the whole the sediments found are quite scarce and lie on planar erosional surfaces shaped on the bedrock, and this suggests that the terraces were mainly erosional. the terraces can be regarded as remnants of an uplifted and eroded platea. the erosional terraces ranging from s1 to s3, therefore, show the different stages of erosion. also the base of the fluvial sediments in the southern area of terrace t4 is erosional. the sediments allow us to assess that the shaping of the erosional terraces occurred during the period between the beginning of the middle pleistocene and the upper pleistocene. the incision of the valleys during the quaternary may be linked to the gradual deepening of the erosion surface north of the hills, while the infilling of the rotaldo and grana valley bottoms may be connected mainly with the aggradation of the fluvial sediments that form the 83 fig. 7 the scarp between the s2 and the t4-3s terraces viewed from the s2 top. the scarp is in the foreground, while in the background lies the pomaro isolated hill (rip). quaternary evolution of the casale monferrato-valenza plain surface of the terrace t4. during the late upper pleistocene or the holocene, the po river, which flowed s and se of casale monferrato (fig. 4), eroded the s2 terrace scarp and captured some stretches of the streams that flowed across the valenza plateau between the rim and the rio (fig. 5). during the late upper pleistocene or the holocene, the river underwent a diversion to the east and began shaping the t5 surface. during the holocene the river eroded the northern side of the rip and the escarpment which limits the valenza plateau to the n, and induced a deepening of the tributary valleys which cut into the plateau in that area. 4.2. evidence of tectonic deformations the existence of quaternary tectonic deformations is proved by the quaternary evolution and by the relations between some morphological features and the structures affecting the bedrock. the monferrato thrust front is the most important tectonic structure having a regional extension that affects the area. since the limits of the buried platea mostly coincide with the younger thrust front or transversal structures (fig. 3) and outside the platea the quaternary sediments become thicker, it can be assumed that compressive tectonics were active during the quaternary. in particular, the stretch of the fronts situated near casale monferrato and ne of pomaro would be the ones most involved in the deformation of the base of the quaternary fluvial sediments, while the giarole and roncaglia faults acted as boundaries of the subsiding borgo san martino syncline or tectonic trough. among other structures, the giarole-lu deformation zone is the one that produced the most evident effects because it separates stretches of plain and hills with different geological and geomorphological features. the interaction between the fluvial and tectonic quaternary evolution could have produced the clearest morphological anomalies that are essentially the hills made of tertiary sediments isolated between quaternary fluvial deposits. the only other isolated hill present north of the arc formed by the monferrato and turin hills is that of trino (rit in fig. 3). it is located in the platea area just south of the monferrato buried front, and it was definitely affected by movements related to compressive tectonics, at least, up to part of the middle pleistocene (gsqp, 1976, enel, 1984; giraudi, 2014) and, according to burrato et al. (2012) and michetti et al. (2012), even in more recent times. in correspondence to the rit, the bedrock is shaped by a series of planar erosion surfaces, covered by fluvioglacial deposits, located at altitudes gradually lower, both to the north and to the south, separated by buried scarps. the topographically higher surfaces are those covered by the older deposits. the isolated hills rip, rio, and rim are also located to the south of thrust fronts (fig. 2; 4) and their edges are sub-parallel to thrust fronts or lie in correspondence of faults transversal to the fronts. also in the area studied, the bedrock is shaped by a series of nearly flat erosion surfaces (corresponding to the top of the isolated hills) lying at different altitudes and separated by scarps. the higher surfaces were most likely produced by the alpine river flowing from the cerrina valley while, after the diversion of that river (see above) dated around 600 ka bp, the erosional terraces s1, s2, s3 were shaped by local streams. there is little doubt, therefore, that the development of the isolated hills is also connected with the quaternary tectonic evolution of the monferrato, as already hypothesized in enel (1984) and carraro (2012). the existence of quaternary tectonic mobility makes it difficult to accept the hypothesis that near-flat surfaces forming the top of the rio and rim isolated hills and the s1 surface were shaped simultaneously as assumed by corsi et al. (1969). the chronological framework of the sediments lying on such surfaces is too loose to support a clear correspondence between them. in the presence of tectonic movements, the erosion surface that was evolving in the area between the thrust front and the hillslope was certainly subject to deformations and these deformations could have been different in areas bordered by the various buried structures. some sectors could have been uplifted and in these the remnants of the erosional surface, covered by thin layers of fluvial sediments, were raised to form terraces higher than the surrounding area. the uplift induced the streams to migrate to topographically lower places where they began to shape new portions of the erosional surface. the interference between tectonics and fluvial erosion would have produced an almost continuous evolution of the erosional surface and the different altitudes at which the erosion terraces lies demonstrate this. a possible confirmation of the continuous erosion is also given by the almost total absence of terraces in the inner portion of the rotaldo and grana valleys. if the modelling of s1, s2 and s3 had occurred during three phases of erosion interrupted by periods of stasis, the three terraces would have formed also within the valleys. thus the continuous down-cutting of the valley bottoms and of the erosion surfaces that formed the terraces allows us to hypothesize a nearly continuous tectonic uplift, common to the hills and to the adjacent terraced plain. figure 8 shows a ssw-nne section (a a’) of s1 on the left of the rotaldo stream and the projection on the same section of the top surface of the rio (section b b’). from the b b’ section we note that the top of the rio, apart from being located at higher altitudes, does not dip towards ne as s1. this situation does not allow for an unambiguous interpretation. one could speculate that tectonic movements have induced changes in the river network. after the shaping of the erosional surface that corresponds to the top of the rio, tectonic deformation induced a diversion towards the ne of the ponara and rotaldo streams that started to shape s1. equally acceptable is the assumption that both the top of the rio and of s1 were shaped by a drainage network having the same direction and that the current slopes of the terraces were pro 84 giraud c. duced subsequently by differential tectonics. in any case, the evolution implies quaternary tectonic deformations. because the rio’s north-western side lies near the rotaldo fault and is parallel to it and other major faults transverse to the monferrato front (terruggia and giarole faults) we can assume that the trend of that side was conditioned by the quaternary activity of the rotaldo fault. the lack of dip towards ne of the top of the rio (fig. 8) may be due to the activity of the occimiano thrust fault, located at the base of the north-eastern slope of the rio, which would have produced the uplift of the area. after the shaping of the top of the isolated hills and of terrace s1, a stream fed at least by the rotaldo and grana valleys flowed to the ese and east, in the area between the hills and the southern slopes of rio, rim and rip, and started to form the s2 terrace. the s2 terrace lies, at least up to valenza, on the axial zone of the castello di lignano and villabella synclines. it can therefore be assumed that the synclines were active and affected the drainage network at least until the late middle pleistocene. the presence of several sectors of the s2 surface, separated by transverse river incisions and located at different altitudes, also suggests that the shaping of the terrace may have been complex, non-uniform and, in detail, not even contemporary in all its extension. in fact, a topographic profile oriented wnw to ese (fig. 8) shows that s2 is located at altitudes not compatible to the west and to the east of the rotaldo and grana faults. the diversion towards the ne of the rotaldo and grana streams shown by the s2 terrace, could evidence that the differential tectonics started to prevail. after the diversions and the sedimentation of the fluvial deposits that form the surface s2, the streams started to downcut the valleys. the colluvia observed on the rio slope confirm the erosion and suggest that the main erosion phase ended with the aggradation of the present valleybottom and the alluvial sediments that occurred during the late upper pleistocene-holocene. the erosion was probably triggered by the uplift of all the area where s2 lies. in fact, if the shaping of s2 and of the older terraces was produced by the climatic cycles, a near continuous belt of terraces having the same age should surround the northern monferrato hillslope, from casale monferrato to turin: as explained before, such terraces do not exist. therefore, the evolution of the drainage network suggests that the phase of deformation, due to structures connected to the thrust front, likely continued after the late middle pleistocene. the tertiary sediments outcropping in the po riverbed (fig. 4) near the thrust front north of the rip (fig. 9), and west of casale monferrato seem to confirm that an erosion surface on the bedrock is evolving even today and that the uplift near the front could still be active. the plain east and south-east of casale monferrato deserves separate discussion because the evidence of tectonic deformation is more ambiguous. the presence of an erosion surface (the platea) also under the sediments of the southernmost t4 terrace could suggest that the erosion, and then the uplift, acted up to the late upper pleistocene. however, since the shaping of this erosion surface is due to the po river, it could be just lateral erosion of tertiary sediments easy to erode. for this area (fig. 4) the coincidence between the 85 fig. 8 cross sections through the terraces s1, s2 and the top of the rio. fig. 9 the po river bed ne of the pomaro-montevalenza isolated hill. the small waterfalls in the river bed (right) evidence the planeparallel layers of tertiary sediments. in the background (left), the northern slope of the isolated hill can be observed. quaternary evolution of the casale monferrato-valenza plain almost straight trend of a stretch of the boundary between t4-2 and t4-3n, and the buried structures at the margins of the platea, have already been highlighted. it is possible that the boundary between t4-2 and t4-3n is the consequence of a tectonic deformation and that the higher surface (t4-1) derives from the tectonic deformation of the top of t4. in this case, one should assume a tectonic mobility more recent that the upper pleistocene. even though it is parallel and in part superimposed on thrust fronts, the possibly uplifted area crosses the roncaglia fault and extends also in an area of prevailing subsidence during the quaternary. the uplift could have been produced by tectonic movements at least in part different from those linked to the monferrato front. the diversion to the east and ne of the po river at casale monferrato (abandoned bed in fig. 4) is compatible with the hypothesis of tectonic deformation of t4. however, there are no clear morphological elements that can confirm the uplift of the area in periods before the upper pleistocene. the absence of traces of an older uplift may be due to river erosion, but it can also be explained by assuming that the tectonic deformation started or intensified during the upper pleistocene. the location of t5 shows some elements worth being discussed. first, from casale monferrato to the area of the rip, t5 is located between t4, to the south, and a terrace, equivalent to t4, to the north of the po river (fig. 2). from the rip area to the se, t4 is lacking and it may have been eroded or it was never formed as a result of the evolution of the hydrographic network. in this area t5 reaches the escarpment of the valenza plateau (s2). precisely in the area where it crosses the monferrato front ne of the rip, the po river, which flowed into the central portion of t5, migrates to the sw following the scarp of the valenza plateau to its end, and then flows to the east, again crossing the front. the distribution of the terraces and the position of the po river suggest that the late pleistocene and holocene river migration could also be influenced by tectonics and that the migration of the river to the s and sw was triggered by the uplift of an area east of the rip. this uplift concerns an area partially outside the buried monferrato front and it is not clear whether the assumed relative uplift is an indication of the ongoing compressive tectonics or if it is linked to other causes. overall, the upper pleistocene and holocene morphological elements that may suggest tectonic mobility are open to more than one interpretation. if they were in fact produced by tectonics, they would not be fully compatible with some older morphological features clearly conditioned by tectonics. the observations about the edge between the terrace s2 and the hillslope, mentioned earlier (fig. 4; 5), can be used in order to prove the relations between the tectonic activity and the morphology. the different position of the boundary between the terrace and the hillslopes at the mouth of some valleys could be due to the displacement of the hillslope produced by transversal tectonics active before and, probably, also after the shaping of the t2 terrace. in correspondence with the giarole-lu deformation zone, at least two of the changes in the position of the boundary between s2 and the hillslope (fig.4) occur ne of two abrupt changes in direction of the divide between the po and tanaro basins and of the deformation of the axes of two anticlines (fig. 4). all these morphological and geological features are compatible with the movements of the left-slip giarole-lu deformation zone (gldz in fig. 4). the deformation zone runs from the thrust front to the hills south of the watershed and reaches at least 15 km in length. the anomalies of the boundary between s2 and the hillslope in the area sse of the rip lie on the valenza deformation zone (fig. 4): the westernmost one lies north of a divide deviation and near the change of the direction of the anticline formed by messinian and tortonian sediments, while the easternmost one lies on the southern prolongation of the valenza fault, on the northwards prolongation of the nnw-sse anticline and north of a noticeable deviation of the divide. these morphological and geological features are all compatible with dislocations produced by right-slip valenza deformation zone (vdz). the length of the deformation zone reaches, at least, 13-14 km. one of the anomalies in the boundary between s2 and the hillslope is at the rotaldo valley mouth and lies on the rotaldo fault. south of this anomaly, on the possible prolongation of the same fault, there is a clear deviation of the divide and the western boundary of the area of anomalous contact between pliocene and premessinian sediments. the joint activity of the giarole-lu (left-slip) and valenza (right-slip) deformation zones would have produced the northward advance of the thrust front north of the rip and of the area located between them. the direction of many streams across the valenza plateau, connected with the holocene t5 terrace, is the same as the geological structures forming the giarolelu and valenza deformation zones. it follows that contractional tectonics may have been still active during the upper pleistocene and holocene or, more likely, that the streams have retained the direction induced by tectonic structures that were active during the late middle pleistocene or early upper pleistocene. in summary, the phase of deformation related to tectonic contraction of the monferrato front lasted, most likely, until the late middle pleistocene or early upper pleistocene. only in the areas of casale monferrato and of frascarolo did some tectonic movements, which may not be linked with certainty to the monferrato front, possibly occur during the upper pleistocene and holocene. even in the adjacent vercelli plain, upper pleistocene and holocene deformations have been observed, partially or totally independent from the monferrato front (giraudi, 2014). in the vercelli plain, where the sedimentary units are much more abundant and better dated, the end of tectonic contraction took place mostly around or before 400 ka bp, and in any case could not be more recent than 280 ka bp, while the deformations independent from the thrust front were particularly intense during the last 140 ka bp. the chronology of the eastern monferrato front seems to indicate a significantly more recent age for the end of tectonic contraction. the morphological differ 86 giraud c. ences between the two zones confirm the different tectonic evolution, excluding the risk that the different chronology of the movements was caused by the approximation of the dating of the sediments and not by a really different evolution. 4.3. tectonic zonation of the po plain and the eastern monferrato area overall, the area where the higher terraces and isolated hills lie could thus be divided into four parts with different quaternary tectonic features (fig. 10). the easternmost area, from the valenza deformation zone to rivarone, is formed only by the terrace s2 and was uplifted at least after the late middle pleistocene or early upper pleistocene. the eastern area, formed by the plain and the hills, situated between the giarole-lu and valenza deformation zones and the thrust front north of the rip, underwent a migration to the north, at least from the lower pleistocene to the end of the late middle pleistocene or early upper pleistocene and an uplift that lasted until the period following the shaping of s2. in this framework, the villabella syncline was able to influence the late middle pleistocene or upper pleistocene drainage network that developed on the s2 terrace. the central area, i.e. the plain located between the giarole-lu deformation zone and the rotaldo valley and the adjacent hills, is affected by the rotaldo, grana and occimiano faults and the borgo san martino syncline, and is disjointed into various sectors. the tectonic activity lasted until the late middle pleistocene or early upper pleistocene. the roncaldo fault forms the western boundary of the area. the grana fault seems a normal fault, because it is not associated with morphological anomalies suggesting horizontal displacements. in this tectonic frame, the occimiano fault may correspond to the thrust front segment that seems to be lacking between the fronts lying near casale monferrato and ne of the rip. the western area, i.e. the plain lying nw of the roncaglia fault and the adjacent hills, would have been subject to an uplift that started around 600 ka bp, after the sedimentation of the fluvial-lacustrine unit dated between 1000 and 600 ka bp. precisely that uplift could have halted the flow of the alpine river that drained the cerrina valley. the uplift continued until the period subsequent to the shaping of s2. even if the roncaglia fault could be of strike-slip or oblique type, in this area there are no morphological features suggesting the activity of strike slip or oblique-slip faults during the late middle pleistocene or later. the disarticulation in tectonic blocks of the area between the giarole-lu deformation zone and the roncaglia fault, and the subsidence of the borgo san martino syncline, may indicate that the central area represents a junction between the nw part, free of late middle pleistocene strike-slip movements and the eastern zone where such movements were active. while the activity of strike-slip faults ended earlier 87 fig. 10 tectonic movements affecting the area studied until the late middle pleistocene or early upper pleistocene. quaternary evolution of the casale monferrato-valenza plain edi evidenziato in the western part (roncaglia fault) and did not occur east of the valenza deformation zone, the uplift of the terraces and the hills seems mainly coeval from west to east. however the presence of the older morphological features (isolated hills and s1 terrace) only in the area west of the valenza deformation zone suggests that the uplift of the (now) terraced plain started in the west and that the deformation zone probably played a role as a boundary of the uplifting area. the po plain, corresponding to the t4 and t5 terraces (fig. 4), shows quaternary subsidence north of the thrust fronts and on the borgo san martino syncline. the subsidence is known to have affected the po basin foredeep during the advance of the thrust fronts (dela pierre et al.,1994). however some morphological features suggest the possibility of late upper pleistocene vertical movements near or outside of some stretches of the thrust fronts. 5. testing the hypothesis of late middle pleistocene or early upper pleistocene thrust front activity: outlines of the quaternary evolution of the alessandria basin in order to test the hypothesis that compressive tectonics continued at least until the late middle pleistocene or early upper pleistocene, we can analyze the quaternary evolution of the alessandria basin suggested by bibliographic data. as noted before, the alessandria piggyback basin subsided as a result of the northward migration of the monferrato thrust. if the migration northward had continued until at least the late middle pleistocene or upper pleistocene, south of the eastern monferrato hills the geological evolution of the basin is expected to show evidence of subsidence up to the same period. the data for the interpretation of the evolution of the alessandria basin are reported in anfossi et al. (1969). observing the terraces in the alessandria basin (fig. 11), one can notice that they were formed by rivers that flowed towards the centre of the basin, that is, towards the area where the thickness of the pliocenequaternary sediments is greater. figure 11 shows that, generally, only the oldest terraces of the tributary rivers of the tanaro (fl1, of undefined pleistocene age, according to anfossi et al., 1969) join the hillsides formed by marine tertiary and villafranchian sediments, and that the lower terraces (fl2, fl3-a1 a2-1; a3) are included between the older terraces and the centre of the basin. this means that the centre of the basin subsided more than its borders. the contact zone between the northern margin of the alessandria basin and the southern slopes of the eastern monferrato, an area which is located just south of the hills lying between the giarole-lu and valenza deformation zones, is an exception. in this area the oldest terrace is lacking and it is the fl2 terrace, attributed to the "middle fluvial", pleistocene in age, by anfossi et al. (1969), that joins the hillslope. the anomaly can be explained by the subsidence of this part of the plain which lasted, at least, until the sedimentation of the fluvial deposits which form the fl2 terrace. the subsidence of the area is also confirmed by the thickness of the quaternary fluvial sediments. according to the maps shown in irace et al. (2009), the thickness of the fluvial sediments forming fl2 south of the hills lying between the giarole-lu and valenza deformation zones is greater than 20 m, while in the adjacent western area the thickness is 10 m or less. the contour lines show that the base of the pliocene reaches its maximum depth se of alessandria, exactly south of the hills lying between the giarole-lu and valenza deformation zones. if the subsidence is due to the northward migration of the monferrato thrust front, we can assume that the thrust was active at least until the shaping of the fl2 terrace. the dating of the terrace fl2, then, is the key to determining the age of the last phases of subsidence. however there is no direct dating of deposits that form the terraces and the chronological framework reported in anfossi et al. (1969) is based on the relative position of the terraces and on the degree of pedogenesis. in a study on the surroundings of asti, just west of the area reported in the present paper, carraro & valpreda (1991) show that the terraces corresponding to fl2 of anfossi et al. (1969) have, at their top, a yellowish soil with a colour index of 7.5 yr mscc. in the area at the northern edge of the alessandria basin according to ajassa et al. (1997), the thickness of the soil does not exceed one metre. according to arduino et al. (1984), this kind of soil can be compared to that which developed in the late middle pleistocene or early upper pleistocene. it follows that the aggradation of the sediments finished before that period. cortemiglia (2012) assumes that the sediments forming the terrace fl2 were deposited between 220 and 128 ka bp and weathered in the period between 128 and 115 ka bp. the age of the sediments fl2, therefore, is not very well determined, ranging from late middle pleistocene to early upper pleistocene, but it is similar to that of the fluvial deposits that form the surface s2 of the valenza plateau. the subsidence of the alessandria piggyback basin in the area south of the giarole-lu and valenza deformation zones continued at least until the late middle pleistocene or early upper pleistocene and seems to confirm the age of the northward compressive tectonics and of the uplift of the area just north of the hills. 6. data on seismicity and aseismic deformations in some areas covered by this study, geodetic measurements have been carried out and stations of the gps network are located. the seismic catalogues (rovida et al., 2011; rsni, 2014 a, b) report the earthquakes recorded in the area. in the paper by arca & beretta (1985), the uplift rate of the casale monferrato area is reported. the uplift rate was obtained by means of a comparison of the data 88 giraud c. fig. 11 terraces surrounding the alessandria basin (redrawn from anfossi et al., 1969) and contour lines of the base of the pliocene (redrawn from bigi et al. (1990). from detailed geodetic measures carried out in 1897 and in 1957 ad. in particular, the points lying on a section from casale monferrato to vercelli, crossing the monferrato thrust front, indicate an uplift rate of 4.32 mm/yr-1 in the town of casale monferrato (south of the front) on the t4 surface, and of 1.37 mm/yr-1 at villanova monferrato, located north of the thrust front. the area south of the monferrato front has an uplift rate three times greater than the area north of it. however, the section does not permit a threedimensional interpretation and it is therefore not possible to determine whether the deformation took place exactly on the front, or along other structures transversal to the front. in any case, between the two surveys no strong earthquakes occurred in the area and thus the deformation was completely aseismic or connected with nonrecorded earthquakes of very low magnitude. the geodetic datum of arca & beretta (1985) would be consistent with the hypothesis of a recent uplift of the area corresponding to the t4 terrace provided by morphological evidence (fig. 10). the same paper also reports the uplift rate (1.2 mm/yr-1) measured in quattordio, on the boundary between the hills and the western edge of the alessandria plain (fig. 10). also in this area no earthquakes occurred between 1897 and 1957, although one of magnitude 4.2, with its epicentre in quattordio, struck the area on july 18, 2001 (rovida et al., 2011; rsni, 2014 a, b). the seismic hazard of the area under investigation is considered low because the earthquakes reported by the catalogues are scarce and of magnitude less than or equal to 5 (rovida et al., 2011; rsni, 2014 a, b). some of the epicentres of earthquakes (fig. 10) of magnitude between 2 and 4.3 are in the giarole-lu deformation zone or their prolongation to the sw, while only three epicentres, including that of the earthquake that struck alessandria in 1369 ad (estimated magnitude around 5, the strongest that occurred in the area) are inside, or 89 quaternary evolution of the casale monferrato-valenza plain near, the valenza deformation zone. some very low magnitude earthquakes occurred near the buried thrust fronts east of the valenza deformation zone. few other earthquakes with magnitude less than 3 occurred in the study area or the surroundings. studies on the data of the gps network (devoti et al., 2011) have shown that the alessandria basin has a negative vertical speed slightly greater than -1 mm/yr-1 and a horizontal speed towards the northern-western quadrant a little less than 2 mm/yr-1. the movements seem compatible with the migration to the n of the area located between the giarole-lu and valenza deformation zones and with the subsidence of the alessandria basin, and could support the hypothesis that tectonic activity still occurs in the monferrato thrust. 7. conclusions the plain between the po river and the eastern monferrato hills consists of fluvial sediments lying on the tertiary marine bedrock. the tertiary sediments are displaced by thrusts and strike-slip or oblique faults produced by the compressive tectonics of the monferrato front, the westernmost of the northern apennine fronts. the presence of a nearly continuous belt of terraces at the base of the northern hillslope, of isolated hills formed by tertiary sediments, and the distance between the po river and the hills are peculiar characteristics of the eastern monferrato and immediately suggest some geological differences between the eastern and the westernmost monferrato-turin hills system. study of the stratigraphy and morphology has enabled us to advance several hypotheses about tectonic mobility during the quaternary. however, the absence of well dated morphological and stratigraphic features suitable for the correlation of the terraces affected by tectonic movements precludes any reliable estimates of the deformation rate. the assumptions regarding the type and age of tectonic deformations are summarized below. the areas located north of the youngest thrust fronts and the area corresponding to the borgo san martino pliocene syncline mainly subsided during the quaternary. on the other hand, starting at about 600 ka bp, the area of the isolated hills rio, rim and rip and s1, s2, s3 terraces suffered an almost continuous uplift until the late middle pleistocene or early upper pleistocene. the dataset makes it possible to assume that compressive tectonics were active at least until that time, and could still be active. the tectonic interpretation of the contour lines of the depth of the pliocene base and the comparison of the altitudes of the top of isolated hills and terraces suggest that the areas where the uplift prevailed were affected by faults transverse to the thrust fronts, and subject to differential movements. the overall interpretation of the tectonic structures lying below the plains and affecting the hills allow us to assume (fig. 4) that there are normal faults (roncaglia, rotaldo and grana faults) and two deformation zones (giarole-lu and valenza deformation zones) where strike-slip or oblique-slip faults that make up the thrust ramps were active until the late middle pleistocene or the early upper pleistocene. in the first deformation zone (giarole-lu deformation zone) ccurred some left-slip displacements, while in the second one (valenza deformation zone) some right-slip deformations would be present. the tectonic movements along the two deformation zones would result in an advance towards the north of the thrust front near the rip. the villabella syncline evolution and the subsidence of the northern alessandria basin between the two deformation zones would be connected with the northward shift of the thrust front. the age of the sediments affected by subsidence in the alessandria piggyback basin corroborate the hypothesis that the activity of the monferrato front continued at least until the late middle pleistocene or the early upper pleistocene. the horizontal and vertical deformation rates obtained by the alessandria gps station seem compatible with the hypothesis of a shift to the north and with a subsidence still in progress. the morphology and distribution of the most recent terraces lying north of the hills suggest that some sectors of the po plain may have been affected by upper pleistocene and holocene tectonic movements. these areas include casale monferrato which underwent a remarkable aseismic uplift during the twentieth century. the possible tectonic mobility of these areas could have been independent from the main structures of the monferrato front. the possible end of the compressive tectonics and the beginning of the deformations related to structures wholly or partly different from those that form the buried monferrato front seem to confirm the findings of the study of the vercelli plain (giraudi, 2014). in the plains north of the eastern monferrato area, however, contractional tectonics would be more recent or still active. it was already known (pieri & groppi, 1981; cassano et al., 1986; costa, 2003; burrato et al., 2012; galadini et al., 2012; galli et al., 2012; michetti et al.,2012) that tectonic activity on the three main fronts of the northern apennines increased from west (monferrato front) to east (emilian and ferrarese fronts). the results of the present study indicate that also in the monferrato front the eastern portion shows greater mobility in a very recent period. aknowledgements: the manuscript has been greatly improved by the suggestions and accurate revision of andrea festa, andrea sposato and maria gabriella forno. references ajassa r., biancotti a., cortemiglia f., cortemilia g.c. (1997) carta geomorfologica della pianura padana (f. 69 and 70). selca, firenze. anfossi g., bruno g.m., casnedi r., mosna s., motta e., perotto g., zezza f. (1969) foglio 70, alessandria, della carta geologica d’italia alla scala 1:100,000, ii ed. servizio geologico d’italia, 90 giraud c. roma. arca s., beretta g.p. (1985) prima sintesi geodeticageologica sui movimenti verticali del suolo nell’italia settentrionale (1897-1957). bollettino di geodesia e scienze affini, 44 (2), 125-156. arduino e., barberis e., carraro f., forno m.g. (1984) estimating relative ages from iron-oxide/totaliron ratios of soils in the western po valley, italy. geoderma, 33, 39-52. arpa piemonte (2014) banca dati geotecnica. available at: http://webgis.arpa.piemonte.it/flxview/ geoviewerrisknat/index.aspx balestro g., cadoppi p., piccardo g.b., polino r., spagnolo g., tallone s., fioraso g., lucchesi s., forno m.g., perrone g., ossella l., campus s., tamberlani f., nocolò g. (2009) note illustrative della carta geologica d’italia alla scala 1:50.000, foglio 155 torino ovest. servizio geologico d’italia, 150 pp. biancotti a., cortemiglia g.c. (1981) ritrovamento di loess sul “fluviale medio” della scrivia presso novi ligure (piemonte, italia). quaderni istituto di geologica dell’università di genova, 2(5), 107 -125. bigi g., cosentino d., parotto m., sartori r., scandone p. (1990) structural model of italy. consiglio nazionale delle ricerche (cnr), progetto finalizzato geodinamica, quaderni de "la ricerca scientifica", 114 (3), 1:500.000 scale, firenze, selca. bonsignore g., bortolami g.c., elter g., montrasio a., petrucci f., ragni u., sacchi r., sturani c., zanella e. (1969) note illustrative della carta geologica d’italia alla scala 1:100.000, fogli 56 “torino” e 57 “vercelli”. servizio geologico d’italia, roma. braga g.p., ragni u. (1969) note illustrative della carta geologica d’italia alla scala 1:100.000 fogli 44 e 58, novara e mortara. servizio geologico d’italia, 56 pp. burrato p., ciucci f., valensise g. (2012) un approccio geomorfologico per la prima individuazione di strutture potenzialmente sismogenetiche nella pianura padana. gngts, atti del 18° congresso nazionale, 18pp. carraro f. (1996) revisione del villafranchiano nell’area-tipo di villafranca d’asti. il quaternario, 9(1), 5-120. carraro f. (2012) geologia del quaternario. l’evoluzione geologica degli ambienti superficiali. 393 pp. d. flaccovio editore, palermo, italy. carraro f., collo g., forno m.g., giardino m., maraga f., perotto a., tropeano d. (1995) l’evoluzione del reticolato idrografico del piemonte centrale in relazione alla mobilità quaternaria. in: polino r. & sacchi r. (eds.), atti del convegno: rapporti alpi-appennino. acc. naz. sci. sc. doc, 14, 445-461. carraro f., valpreda e. (1991) the middle-upper quaternary of the “asti basin”. il quaternario, 4(1a), 151-172. casnedi r. (1975) segnalazione di una successione stratigrafica compresa tra il langhiano e il pliocene inferiore a nw di valenza (monferrato orientale). rendiconti scientifici istituto lombardo, a 109, 178-184. cassano e., anelli l., fichera r., cappelli v. (1986) pianura padana: interpretazione integrata di dati geofisici e geologici. 73° congresso della società geologica italiana. 1-27. corsi m., gatto g.o., gatto p. (1969) foglio 58 “mortara” della carta geologica d’italia alla scala 1:100,000. ii ed., servizio geologico d’italia, roma. cortemiglia g.c. (2012) lineamenti generali della storia climatica del territorio alessandrino (piemonte, italia). atti società toscana di scienze naturali, memorie, serie a, 117-119, 5-16, doi: 10.2424/astsn.m.2012.23. costa m. (2003) the buried apenninic arcs of the po plain and northern adriatic sea (italy): a new model. bollettino società geologica italiana, 122, 3-23. de la pierre f., michailov v., polino r. (1995) the tectonosedimentary evolution of the tertiary basins in the western po plain: kinematics inferred from subsidence curves. in: polino r. & sacchi r. (eds.), atti del convegno: rapporti alpiappennino. acc. naz.sci.sc.doc, 14, 129-146. de la pierre f., piana f., fioraso g., boano p., bicchi e., forno m.g., violanti d., clari p., polino r (2003a) carta geologica d'italia alla scala 1:50.000, foglio 157 "trino". apat, agenzia per la protezione dell'ambiente e per i servizi tecnici, dipartimento difesa del suolo, roma. de la pierre f., piana f., fioraso g., boano p., bicchi e., forno m.g., violanti d., balestro g., clari p., d’atri a., de luca d., morelli m., ruffini r. (2003b) note illustrative della carta geologica d’italia alla scala 1:50,000, foglio 157 trino. apat, agenzia per la protezione dell’ambiente e per i servizi tecnicidipartimento difesa del suolo, roma, 147 pp. devoti r., esposito a., pietrantonio g., pisani a.r., riguzzi f. (2011) evidence of large scale deformation patterns from gps data in the italian subduction boundary. earth and planetary science letters, 311, 230-241. enel (1984a) rapporto per la localizzazione di una centrale elettronucleare nella regione piemonte. area po 1. enel direzione delle costruzioni, roma. xix volumes, unpublished. enel (1984b) rapporto per la localizzazione di una centrale elettronucleare nella regione piemonte. area po 2. enel direzione delle costruzioni, roma. xix volumes, unpublished. festa a., boano p., irace a., lucchesi s., forno m.g., dela pierre f., fioraso g., piana f. (2009b) note illustrative della carta geologica d’italia alla scala 1:50,000, foglio 156 torino est. apat, agenzia per la protezione dell’ambiente e per i servizi tecnicidipartimento difesa del suolo, roma, 143 pp. forno m.g. (1979) il “loess” della collina di torino. geografia fisica e dinamica quaternaria, 2, 105 -124. 91 quaternary evolution of the casale monferrato-valenza plain ms. received: november 25, 2014 final text received: april 07, 2015 forno m.g., gattiglio m., comina c., barbero d., bertini a., doglione a., gianotti f., irace a., martinetto e., mottura a., sala b. (2015) stratigraphic and tectonic notes on the villafranca d’asti succession in type-area and castelnuovo don bosco sector (asti reliefs, piedmont). alpine and mediterranean quaternary, 28(1), 5-27. galadini f., falcucci e., galli p., giaccio b., gori s., messina p., moro m., saroli m., scardia g., sposato a. (2012) time intervals to assess active and capable faults for engineering practices in italy. engineering geology, 139-140, 5065. galli p., castenetto s., peronace e. (2012) may 2012 emilia earthquakes (mw 6, northern italy): macroseismic effects distribution and seismotectonic implications. alpine and mediterranean quaternary, 25(2), 105-123. gattiglio m., forno m.g., comina c., doglione a., violanti d., barbero d. (2015) the involving of the plio-pleistocene succession in the t. traversola deformation zone (nw italy). alpine and mediterranean quaternary, 28(1). giraudi c. (1981) presenza di depositi mediopleistocenici intensamente deformati in val cerrina (monferrato settentrionale). geografia fisica e dinamica quaternaria, 4, 69-74. giraudi c. (1998) l'evoluzione del po nei pressi di trino (prov. di vercelli piemonte) tra l'eta' del bronzo ed il xvii secolo. il quaternario, 11(2), 227-232. giraudi c. (2014) quaternary studies as a tool to validate seismic hazard potential of tectonic structures: the case of the monferrato thrust front (vercelli plain, nw italy). alpine and mediterranean quaternary, 27(1), 5-28. giraudi c., venturino m. (1983) conzano, loc. cascina mongianone (prov. di alessandria). rinvenimento di reperti litici isolati. quaderni della soprintendenza archeologica del piemonte, 2, 144145. giraudi c., mottura a., sala b., siori m.s., bormioli d. (2003) the castagnone site (cerrina valley, monferrato hills, nw italy): early pleistocene sedimentary record and biochronology. rivista italiana di paleontologia e stratigrafia,109 (3), 517-526. gsqp-gruppo di studio del quaternario padano (1976) studio interdisciplinare del "rilievo isolato" di trino (bassa pianura vercellese, piemonte), quaderno n.3, litografia massaza e sinchetto, torino. irace a., clemente p., natalicchio m., ossella l., trenkwalder s., de luca d.a., mosca p., piana f., polino r., violanti d. (2009) geologia e idrostratigrafia profonda della pianura padana occidentale. 110 pp, 61 allegati. la nuova lito, firenze. martinis b. (1954) ricerche stratigrafiche e paleontologiche sul pliocene piemontese. rivista italiana di paleontologia e stratigrafia, 60, 45-114 and 125194. michetti a. m., giardina f., livio f., mueller k., serva l., sileo g., vittori e., devoti r., riguzzi f., carcano c., rogledi s., bonadeo l., brunamonte f., fioraso g. (2012) active compressional tectonics, quaternary capable faults, and the seismic landscape of the po plain (northern italy). annals of geophysics, 55, 5, 969-1001. montrasio a., ragni u., bonsignore g., borgo a., zanella e., crema g., medioli f., petrucci f. (1969) foglio 57 “vercelli” della carta geologica d’italia alla scala 1:100,000. ii ed., servizio geologico d’italia, roma. mosca p., polino r., rogledi s., rossi m. (2010) new data for the kinematic interpretation of the alpsapennines junction (northwestern italy). international journal of earth sciences, 99 (4), 833-849. negri f. (1884) (no-title). l’elettore, 17, 25/4/1884, casale monferrato. pieri m., groppi g. (1981) subsurface geological structure of the po plain, italy. quaderni cnr. programma finalizzato geodinamica. roma:1-13. rovida a., camassi r., gasperini p., stucchi m. (2011) cpti11, the 2011 version of the parametric catalogue of italian earthquakes. milano, bologna, http://emidius.mi.ingv. it/cpti, doi: 10.6092/ingv.it-cpti11. rsni-regional seismic network of northwestern italy database (2014a) mappe di sismicità strumentale 1982-2013. university of genova, http:// www.distav.unige.it/rsni/ita/index.html rsni-regional seismic network of northwestern italy database (2014b) mappe di sismicità storica (1000-2006). university of genova, http:// www.distav.unige.it/rsni/ita/index.html sacco f. (1889) il bacino terziario e quaternario del piemonte. atti società italiana di scienze naturali, 31-32, 135-281, 289-398, 331-390. tropeano d., olive p. (1989) vitesse de la sedimentation holocéne dans la plaine occidentale du po (italie). bulletin de l’association francaise pout l’etude du quaternaire, 2, 65-7. 92 giraud c. amq32(1) 5-13 ragaini et al + ring.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 32 (1), 2019, 5 13 mineralogy and oxygen isotope profile of pelecyora gigas (veneridae, bivalvia) from tuscan pliocene luca ragaini 1, federica ficini 1, giovanni zanchetta 1, eleonora regattieri 1,2, natale perchiazzi 1, luigi dallai 2 1dipartimento di scienze della terra, università di pisa, pisa, italy. 2istituto di geoscienze e georisorse, igg-cnr, pisa, italy. corresponding author: l. ragaini <luca.ragaini@unipi.it> abstract: a specimen with joined valves of pelecyora gigas, an extinct species, was collected in a sandy layer of early pliocene age in the northern part of the siena basin (tuscany, italy). xrd data demonstrated that the original mineralogical composition of the specimen was aragonitic and it maintained substantially the original structure and composition. neglecting possible changes in sea salinity during different seasons, we can estimate, using oxygen isotope composition a maximum seasonal temperature differences of ca. 9 °c experienced during the life of the individual. an approximate estimation of past sea water composition allows to calculate an average temperature of 23.0±2.7 °c for the water where the shell lived, whereas calculated temperature extremes are 18.5 °c for the colder season and 27.6 °c for the warmer. these data are in a good agreement with those proposed on the basis of the pliocene mediterranean taxa nowadays living along the western african shores. keywords: pelecyora gigas, shell mineralogy, isotopic composition, pliocene temperatures, tuscany. 1. introduction many factors may influence the biogeography of shallow marine benthic molluscs such as nutrients, predation, competition, substrate, natural barrier, ocean circulation (monegatti & raffi, 2001; silva et al., 2006). however, it is largely accepted that sea surface temperature (sst) plays the major role in controlling the latitudinal distribution of benthic organisms on the continental slope (hall, 1964; petuch, 2004). in this context the critical factor does not lie as much in the temperatures suitable for the survival of specimens but rather the duration of the time interval in which the sea water is at the temperature required for successful reproduction and early growth (raffi, 1986; raffi et al., 1985; 1989). even though the pliocene period appears to have been, on average, warmer than present (jansen et al. 2007), it is characterized by climatic cooling phases recorded in the northern hemisphere by paleontological and isotopic data (stanley, 1986; stanley & ruddiman, 1995; mudelsee and raymo, 2005; haug et al., 2005; lisiecki & raymo, 2007; lawrence et al., 2009). the two major cooling events occurred at about 3.1 ma and 2.7 ma (the latter just older than the recently revised plio-pleistocene boundary, gibbard et al., 2009) and caused pulses of extinction and local disappearance among the mediterranean mollusc fauna (monegatti & raffi, 2001; monegatti et al. 2002; monegatti & raffi, 2010). this fact results in a pliocene decrease of the mollusc diversity because faunal impoverishment is not balanced by recovery phases, probably owing to an upwelling phenomenon along the northwest african coasts, which appears to have intensified since the middle pliocene (cita & ryan, 1979; sarnthein et al., 1992; monegatti & raffi, 2001). during the early-early middle pliocene the mediterranean basin was populated by a thermophilic malacofauna thriving in a tropical sea with estimated mean maximum ssts over 24–25 °c for at least five to six months every year (monegatti & raffi, 2001; silva et al., 2010); the molluscan fauna is categorized as mpmu1 by raffi & monegatti (1993) and monegatti & raffi (2001). at least as far as molluscan fauna is concerned, this temperature regime remains substantially stable up to about 3.1 ma, when the first cooling event, even though not so severe as that at 2.7 ma, has dramatic results for the early pliocene thermophilic fauna. the disappearance of strombus coronatus and the drastic decrease of the taxonomic diversity of conidae and terebridae are the most relevant events among gastropods whereas bivalves offer a more detailed and quantitative approach thanks to the hundreds of infraand circalittoral species https://doi.org/10.26382/amq.2019.01 6 ragaini l. et al. taken into account by monegatti & raffi (2001). in correspondence to, or just after, the 3.1 ma event, a percentage of bivalves varying from 15% to 23% (more than 50 and no more than 80 species) disappears from the mediterranean (raffi & monegatti, 1993), owing to both regional disappearances and true extinctions (sensu raffi et al., 1985; 1989). among 13 and 17 species typical of mpmu 1 are still living along the west african coasts south of latitude 20-22°n (i.e. the tropical mauritaniansenegalese province of hall, 1964) but this stock appears to be negligible in comparison with that of the extinct taxa. pelecyora gigas is a large, thick-shelled bivalve typical of the early pliocene tropical environments in the mediterranean basin, that becames extinct during, or just after, the 3 ma cooling event. this species has been little studied and research results are restricted to the systematic perspective and are mainly concentrated in the 1960s and 1970s (tavani & tongiorgi, 1963; palla, 1966; malatesta, 1970, among others). the aim of the present study is: to analyze the shell composition of pelecyora gigas to investigate its original mineralogy; to reconstruct the shell growth pattern; to measure the oxygen isotope composition of the shell and to interpret these data with regard to climate conditions of the mediterranean during the early pliocene. concerning the last point, stable isotope analysis of the plio-pleistocene molluscs in tuscany was pioneered in the late 60s to 70s of the last century and then almost completely forgotten (longinelli et al., 1961; vergnaud grazzini, 1968). to better understand and constrain future climate change in a high co2 world, it is essential to study potential co2 concentration analogues in earth’s history and the climate at that time. the pliocene epoch prior to the intensification of northern hemisphere glaciation at about 2.75 ma is a likely candidate for such a high co2 analogue (e.g. bartoli et al., 2011) and this should encourage to a reappraisal of the study of the pliocene marine successions preserved in tuscany. 2. geological and paleontological data the p. gigas specimen was gathered from a pliocene sandy level outcropping near colle d’arbia (monteaperti, siena) in the northern part of the siena basin (tuscany, italy). this is part of a broader tectonic depression, nnw–sse oriented, traditionally interpreted as a half-graben formed in the framework of late miocene-quaternary polyphase extensional tectonics of northern apennines (bossio et. al., 1993; carmignani et al., 2001; brogi, 2011) (fig. 1). the neogene sedimentary infill of the siena basin starts with a miocene (late messinian) succession overlying the pre-neogene bedrock composed of several metamorphic and non-metamorphic tectonic units (brogi, 2011). miocene sediments are in turn overlain by pliocene ones with an intervening angular unconformity (costantini et al., 2009). pliocene deposits of the northern part of this basin, mainly consisting of sands with gravel and mud intercalations, have been recently mapped as a succession of four depositional sequences (martini & aldinucci, 2017; martini et al., 2011) ranging from early zanclean to piacenzian in age. in particular the sequence s3, the fossil bearing unit, ranges within the late zanclean-early piacenzian time span (martini & aldinucci, 2017). from the taphonomic point of view, the fossil speci fig. 1 location map of the fossiliferous outcrop (scale map 1:10.000). fig. 2 p. gigas just after the extraction. note the original horizontal position. 7 mineralogy and oxygen isotope of pelecyora gigas men displays conjoined valves in a nearly horizontal position, which reflects a post mortem dislodging due to wave/current sweeping action (fig. 2) however, the presence of an articulated individual with nearly complete valves displaying one of these with the ventral margin broken but nearly whole (i.e. each piece of the shell is juxtaposed with the surrounding ones) along with the general good state of shell preservation allow us to infer low energy conditions after the exhumation consistent with minimal post-mortem disturbances, very little reworking and negligible transportation. inconspicuous signs of bioerosion and encrustation suggest a rapid burial, which also promotes the conservation with articulated valves. p. gigas is a large and thick-shelled venerid reaching the largest dimensions known within this genus, a characteristic which seems typical of species living in tropical environments (marasti & raffi, 1980). regarding the paleoecological evidence, this species has been frequently recognized in inner subtidal sandy bottoms (bernasconi & robba, 1993; d’alessandro et al., 2004; ferrero et al., 2005), a substrate preference consistent with the grain size (sand 80.07%, silt 17.41%, clay 2.51%) of the siliciclastic sediment of the colle d’arbia outcrop. p. gigas is considered a suspension-feeder, which lived as a sluggish active shallow-burrower, a life habit suggested by the shell thickness, shape and size along with the pallial sinus form (stanley, 1970). however, the relationship between the burrowing depth and the shell/pallial sinus morphology discussed in the pioneering work of stanley (1970) is not sufficient to be used as a clue to reconstruct the burial depth of extinct species. taking into account both the horizontal position displayed by the specimen and the average level of sediment reworking in shallow water sandy bottoms (about 15-20 cm), it seems reasonable to consider the above measure as the burrowing depth attained by our individual of p. gigas. a closer relationship between burrowing depth and pallial sinus length is suggested by kondo (1987) on the basis of the ratio of pallial sinus to shell length (pallial sinus index, psi). this index is very useful in active burrowing, suspension-feeding siphonate bivalves and may be also useful for extinct species. the psi calculated for our p. gigas specimen corresponds to a burrowing depth of 1-2 times the shell length, a result consistent with that previously inferred. in terms of the bionomic model of peres & picard (1964), this venerid is considered an infralittoral species referable to fine well sorted sand (sfbc) biocenosis (bernasconi & robba, 1993; d’alessandro et al., 2004). p. gigas ranges from the early miocene to the middle pliocene. during the pliocene this venerid is widefig. 3 closeup of the x-ray pattern region hosting major diffraction peaks for aragonite and calcite, showing that aragonite is the major phase in the analysed sample. spread over the whole mediterranean basin from the eastern (turkey) to the western (andalusia) part (erunal -erentoz, 1958; vera-pelaez et al., 1995) with a sole atlantic finding along the moroccan coast (lecointre, 1952). 3. shell mineralogy apart from the presence of trace components, the mineralogical composition of bivalve shells ranges from pure aragonite to pure calcite, the latter being a rather rare case. usually calcite secreting bivalves are those with an epifaunal life habit whereas those with an infaunal life habit form wholly aragonitic shells. in particular, calcitic continous layers have been recognized only in some taxa, such as eupteriomorphs, hippuritoida (a group of extinct rudists), some mytiloids and chamoids (carter, 1980; esteban-delgado et al., 2008). within veneridae, the shell mineralogy is generally uniform being composed of minute aragonite crystals, with some exceptions being representatives of saxidomus, protothaca and irus where small calcitic structures, mainly described as “conellae”, are present in the outer part of the outer shell layer (carter et al., 1998). most of the studies concerning veneridae shell mineralogy are focussed on the living taxa (shimamoto, 1986; glover & taylor, 2010) and very few data are available on fossil species, such as p. gigas. in order to identify the mineral phases in the skeleton of this taxon, an x-ray powder diffraction analysis was carried out. the shell sample was crushed into small pieces and then ground in an agate mortar, with subsequent milling under acetone to produce a fine powder (grain size nearly 5-10 μm) which was loaded into a capillary 0.7 mm in diameter. x-ray diffraction data were obtained using a brucker d8 advance diffractometer, equipped with primary ge (111) monochromator and with a braun psd linear detector. the running conditions were: 40 kv, 40 ma, 2θ range 21° to 70°, 2θ step 0.0157°, measurement speed 6 sec/step psd measurement width 4°. experimental data were examined through the eva bruker software: in fig. 3 is shown the diffraction pattern after background subtraction, together with the pdf reference patterns for calcite (blue bars, pdf 83-1762) and aragonite (red bars, pdf 41-1475) one can notice that aragonite (red bars) is clearly the major phase, and that the presence of calcite, if any, is very minor. to precisely evaluate the presence of calcite, the experimental data were elaborated through a rietveld refinement, performed with the topas-academic program (coelho, 2018) for mineralogical quantitative analysis for mixtures including both crystalline and amorphous phases. in a rietveld refinement, the difference between the observed and calculated intensities is minimized at every 2θ point of the observed powder diffraction pattern, namely: the weight fractions of the phases in a mixture can be derived from the refined scale factors of each phase sp, through the expression: where w is the relative weight fraction of phase p in a mixture of n phases, and s, z, m, and v are, respectively, the rietveld scale factor, the number of formula units per cell, the mass of the formula unit (in atomic mass units) and the unit cell volume (in å3). structural models for the rietveld refinement were taken from literature (calcite: effenberger et al., 1981; aragonite: dal negro & ungaretti, 1971), and only aragonite cell parameters were refined. during the refinement, a parameter taking into account asymmetry, determined from the refinement of srm 675 nist standard, was introduced and not refined. background was modelled with a 12-terms chebychev function, and a pseudo-voigt function was used for peak shape. a common lorentzian parameter for crystallite size was introduced and refined for aragonite and calcite to model peak width. final agreement factors for the refinement (fig. 4) were satisfactory, with the figures rwp =2.817 %, rp =2.167 %, gof =1.087. in conclusion, shell mineralogical data based on xray diffraction suggest that our specimen of p. gigas was originally aragonitic and reasonably retained its pristine mineralogy; therefore, it seems very unlikely that diagenesis has reset the shell isotopic composition (dodd & stanton, 1976). 4. oxygen isotope composition the external shells were drilled in an ontogenetic sequence, from the umbo towards the ventral margin (e.g. krantz et al., 1987) using a dremel microdrill equipped with a 1 mm bit, with average distance between the center of the holes of ca. 1.5 mm. 44 samples were obtained (fig.5). stable isotope analysis on the obtained powder was performed using a gas bench ii (thermo scientific) coupled to a delta xp irms (finnigan) at the institute of geosciences and earth resources of the italian national research council (igg-cnr) in pisa (italy). carbonate samples of ca. 0.15 mg of caco3 were dissolved in h3po4 (105%) for one hour at 70°c. sample results were corrected using the international standard nbs-18 and a set of 3 internal standards, previously calibrated using the international standards nbs-18 and nbs-19. isotopic results are reported using the conventional δ‰ notation, with reference to the vpdb standard; δ18o values of water are quoted with the reference to vsmow. analytical uncertainty (±1σ) for δ18o was ±0.20‰. the equilibrium oxygen isotopic composition of marine biogenic carbonates primarily depends on the temperature of carbonate deposition and on the oxygen isotope composition of the surrounding sea-water (epstein et al., 1953). the latter is globally influenced by continental ice volume and locally by salinity variations (i.e. mixing with freshwater and/or evaporation, e.g. 8 ragaini l. et al. shackleton, 1987). with only the δ18o of carbonate, neither the δ18o of water nor paleotemperature can be reliably determined without independent quantification of one or the other. although complex in detail, oxygen isotope composition of samples collected along the shell growth have been demonstrated to be related to changes of seasonal conditions like in change in temperature and salinity (e.g. schöne et al., 2007; leng et al., 1998; collareta et al., 2018). therefore, analysing isotopic composition along the shell growth, it is possible to calculate the seasonal changes in temperature, reasonably assuming constant isotopic composition of sea water during the year. moreover, for most bivalves, precipitation close to equilibrium can be assumed (wefer & berger, 1991) even in absence of calibration of a single species. there is discussion concerning the best equation for calculating paleotemperature (patterson et al., 1993; kim & o’neil, 1997; white et al., 1999; zanchetta et al., 2005) and the ideal would be to have specific equation for each species. however, different calibrations usually differ only slightly in the term of rate of change in dα/dt, where α is the fractionation factor between water and calcite and t is the temperature (white et al., 1999) but can differ for the absolute value of temperature determined. for the reconstruction of the paleotemperatures (sst °c) from shell oxygen isotopes we used the equation for aragonite given by grossman & ku (1986), with a correction for the conversion of v-smow to v-pdb (dettman et al.,1999). sst(ºc)=20.60-4.34[δ18oshell-vpdb-(δ18owater-vsmow-0.27)] (1) this implies that for a constant isotopic composition of seawater the δδ18o/δt ~0.23‰/°c. the average δ18o values measure along the profile is 0.06 ±0.61 ‰ the maximum values and the minimum are 1.12‰ and -0.99‰ respectively. this implies a maximum difference in temperature during the life of the mollusc of ca. 9.2°c. at least three clear seasonal oscillations are visible (fig. 6) in the δ18o profile. at the edge of shells the ontogentic reduction of shells growth (e.g. aguirre et al., 1998) complicate the identification of seasonal cycles at the resolution adopted. however, it seems reasonable to assume that the specimen represents more than 2 yr of δ18o record. to calculate past “absolute temperature” is difficult because of the absence of accurate evaluation of past 9 fig. 4 rietveld refinement plot, closeup of the 2θ range 25-50°; dark blue line represents the observed pattern, red line the calculated pattern. their difference line is represented by the lower trace, with vertical marks showing the calculated positions of bragg reflections for aragonite and calcite. fig. 5 the specimen of p.gigas showing the stable isotope sub-sampling tracks. mineralogy and oxygen isotope of pelecyora gigas sea water isotopic composition. current δ18o values of western mediterranean can range from ca. +1.3 to +1.4‰ (pierre, 1999). mediterranean is today considered a concentration basin due to the deficit in the hydrological budget and this has been probably true already during the pliocene (bianchi et al., 2012). this implies that local isotopic composition is higher than the ocean average owing to evaporation. in addition, it must be considered that pliocene sea level was higher than today associated to lower isotopic composition of seawater for a lower mass of continental ice. multiple lines of evidence suggest that the sea level during the middle pliocene was >20 m above present sea level and a value of +25 m is often adopted in numerical climate model simulations (dwyer and chandler, 2009; miller et al., 2012; rohling et al., 2014 and reference therein). in many estimate for the quaternary period, the relation of ca. 0.009 ‰/m of eustatic sea level variation has been found (rohling et al., 2014). assuming an eustatic component of +25 m, the isotopic water should be on average ca. -0.25 ‰ lower than today. more recently, estimates of isotopic composition of global ocean for the eustatic component suggest an average value ca. -0.5‰ less than today for the pliocene at around ca. 3 ma (rohling et al., 2014). these differences in estimate may insert some incertitude in the final temperature estimate of ca. 1°c or more, if the sea level was higher than assumed. the subdued variance of oxygen isotopic time series on benthic foraminifera during the interval of 3-5 ma (lisieki & raymo, 2005, 2007) suggest a very minor “ice volume effect” (shackleton, 1987); nevertheless this can introduce additional uncertainty to our estimation. assuming a similar relation between salinity and oxygen isotope composition of sea water in western mediterranean, a reasonable estimate using the discussed figures would be ca. +0.9‰ for the oxygen isotopic composition of western mediterranean sea water. this does not account for local changes in salinity and in the following calculation, we neglect seasonal change in salinity. this can introduce further error in the proposed calculation. therefore, the average temperature obtaining from these figures is 23.0±2.7°c, whereas extremes calculated temperature are 18.5°c and 27.6°c respectively. the average maximum temperature obtained for each cycle is 26.6±0.7°c, whereas the minimum is 19.3±0.7°c. p. gigas belongs to the mpmu1 mollusc group including a stock of thermophilic taxa that no longer exist in the mediterranean waters. about fifteen species of this stock (named “ mediterranean pliocene tropical survivors”, mptss) are living along the coast of west tropical africa south of latitude n 21° (cape blanc) (monegatti & raffi, 2001), the northern limit of the northern alternance region of le loeuff & von cosel (1998). taking into account that the areas currently populated by these taxa are characterized by ssts over 24°c for at least five to six months per year and never cooler than 19°c (data from noaa-cires climate diagnostic center) and that the mpts and the most common tropical extinct species were living everywhere in the mediterranean basin before 3.1 ma, an analogous sst pattern has been suggested for mpmu1 time interval (monegatti & raffi, 2001, 2007; silva et al., 2006, 2010). our temperature estimations based on p. gigas isotope composition are in very good agreement with the aforementioned data and strongly support typical tropical conditions in the mediterranean during the zancleanearly piacenzian. this fact confirms the thermophilic character of p. gigas and that its extinction was caused by the first pliocene climatic cooling at around 3.1 ma. 5. conclusion in this paper we describe the mineralogy and the oxygen isotope composition of a fossil shell of pelecyora gigas found in a pliocene sandy layer in central tuscany (central italy). p. gigas is an extinct thermophilic species of the lower pliocene of the mediterranean basin, disappearing during the first cooling step at ca. 3 ma (monegatti & raffi, 2001). new data on mineralogy indicate that the shell was aragonitic as are most bivalves. petrography and xrd indicate that the selected specimen was perfectly preserved and suitable for stable isotope analyses. neglecting possible changes in sea salinity during different seasons, δ18o values allow calculating a maximum seasonal temperature differences during the life of the shell of ca. 9°c. a crude estimation of past sea water composition allows to calculate an average temperature of 23.0±2.7°c, whereas extremes of calculated temperature are 18.5°c for the colder season and 27.6°c for the warmer. these preliminary data indicate that p. gigas would represent an interesting archive to reconstruct seasonal climatic variation during the warmer part of the pliocene, a period which, to some extent, represents a potential analogues for future projection owing to increasing of atmospheric co2 concentration toward values typical of the pliocene (bartoli et al., 2011). acknowledgements this paper is dedicated to the memory of antonello bonadonna, for his dedication to quaternary geology and the paleontology, his important contributions to geology and paleontology will always be remembered. gz wants to dedicate this paper to his unforgettable master and his political passion. this project is partially funded by: project pra (2017/18) “palaeoclimatic palaeoenvironmental evolution of the apuan area since the last glacial maximum”. (leader c. baroni), funded by pisa university. references aguirre m.l., leng m.j., spiro b. (1998) variation in isotopic composition (c, o and sr) of holocene mactra isabelleana (bivalvia) from the coast of buenos aires province, argentina. the holocene, 8, 613-621. bartoli g., hönisch b., zeebe r.e. (2011) atmospheric co2 decline during the pliocene intensification of northern hemisphere glaciations. paleoceanography, 26, pa4213. bernasconi m., robba e. (1993) molluscan paleoecology and sedimentological features: an integrated approach from the miocene meduna section, 10 ragaini l. et al. valves (unionidae). geochimica et cosmochimica acta, 63, 1049-1057. dodd j.r., stanton r.j. (1976) paleosalinities within a pliocene bay, kettlement, california: a study of the resolving power of isotopic and fauna techniques. geological society of american bulletin, 87, 51-64. dwyer g.s., chandler m.a. (2009) mid-pliocene sea level and continental ice volume based on coupled benthic mg/ca palaeotemperatures and oxygen isotopes. philosophical transactions royal society a, 367, 157-168. effenberger h., mereiter κ., zemann j. (1981) crystal structure refinements of magnesite, calcite, rhodochrosite, siderite, smithonite, and dolomite, with discussion of some aspects of the stereochemistry of calcite type carbonates. zeitschrift für kristallographie . 156, 233-244. epstein s., buchsbaum r., lowenstam h. a., urey, h. c. (1953) revised carbonate-water isotopic temperature scale. geological society of america bulletin, 64(11), 1315-1326. erunal-erentoz l. (1958) mollusques du néogène des bassins de karaman, adana et hatay (turquie). publications de l’institut d’etudes et recherches minières de turquie, 4, 1-232. esteban-delgado f.j., harper e.m., checa a.g., rodriguez-navarro a.b. (2008) origin and expansion of foliated microstructure in pteriomorph bivalves. biological bullettin, 214(2), 153-165. ferrero e., merlino b., provera a., martinetto e. (2005) associazione a molluschi marini e vegetali terrestri del pliocene di castellengo, biella, italia nw). rendiconti società paleontologica italiana, 2, 87106. gibbard p.l., head m.j., walker m.j.c., and the subcommission on quaternary stratigraphy (2009) formal ratification of the quaternary system/ period and the pleistocene series/epoch with a base at 2.58 ma. journal of quaternary sciences, 25(2), 96-102. glover e.a., taylor j.d. (2010) needles and pins: acicular crystalline periostracal calcification in venerid bivalves (bivalvia: veneridae). journal of molluscan studies, 76(2), 157-179. grossman e.l., ku t.l. (1986) oxygen and carbon isotopic fractionation in biogenic aragonite: temperature effects. chemical geology, 59, 59-74. hall c. (1964) shallow-water marine climates and molluscan provinces. ecology, 45, 226-234. haug g.h., ganopolski a., sigman d.m., rosell-mele a., swann g.e., tiedemann r., jaccard s.l., bollmann j., maslin m.a., leng m.j., eglinton g. (2005) north pacific seasonality and the glaciation of north america 2.7 million years ago. nature, 433, 821-825. kim s.-t., o’neil j.r. (1997) equilibrium and nonequilibrium oxygen isotope effect in synthetic carbonates. geochimica and cosmochimica. acta, 61, 3461-3475. kondo y. (1987) burrowing depth of infaunal bivalves observation of living species and its relation to shell morphology. transactions and proceedings of the palaeontological society of japan, 148, 306northern italy. palaeogeography, palaeoclimatology, palaeoecology, 100, 267-290. bianchi c.n., morri c., chiantore m., montefalcone m., parravicini v., rovere, a. (2012) mediterranean sea biodiversity between the legacy from the past and a future of change. in: life in the mediterranean sea: a look at habitat changes. nova publisher, 1-55. bossio a., costantini a., lazzarotto a., liotta d., mazzanti r., mazzei r., salvatorini g., sandrelli f. (1993) rassegna delle conoscenze sulla stratigrafia nel neoautoctono toscano. memorie della società geologica italiana, 49, 17 98. brogi a. (2011) bowl-shaped basin related to low-angle detachment during continental extension: the case of the controversial neogene siena basin (central italy, northern apennines). tectonophysics, 459, 54-76. carmignani l., decandia f.a., disperati l., fantozzi p.l., kligfield r., lazzarotto a., liotta, d. meccheri m. (2001) inner northern apennines. in: gian battista, vai, peter martini, i. (eds.), anatomy of an orogen: the apennines and adjacent mediterranean basins,. kluwer academic publications, 197214. carter j.g. (1980) guide to bivalve shell microstructures. in: rhoads, d. c. and lutz, r. a. (eds.), skeletal growth of aquatic organism. plenum press, new york, 645-670. carter j.g., barrera e., tevesz m.j.s. (1998) thermal potentiation and mineralogical evolution in the bivalvia (mollusca). journal of paleontolology, 72, 991-1010. cita m.b., ryan w.b.f. (1979) late neogene environmental evolution. proceedings odp initial reports, 47, 447-460. coelho a.a. (2018) topas and topas academic: an optimization program integrating computer algebra and crystallographic objects written in c++. journal of applied crystallography, 51(1), 210-218. collareta a., regattieri e., zanchetta g., lambert o., catanzariti r., bosselaers m., covello p., varola a., bianucci, g. (2018) new insights on ancient cetacean movement patterns from oxygen isotope analyses of a mediterranean pleistocene whale barnacle. neues jahrbuch für geologie und paläontologie-abhandlungen. 288(2), 143-159. costantini a., decandia f. a., lazzarotto a., liotta d., mazzei r., pascucci v., salvatorini g., sandrelli f. (2009) carta geologica d’italia alla scala 1:50.000, foglio 296-siena, tipografia a.t.i., apat-roma, pp. 129. d’alessandro a., massari f., davaud e., ghibaudo g. (2004) pliocene-pleistocene sequences bounded by subaerial unconformities within foramol ramp calcarenites and mixed deposits (salento, se italy). sedimentary geology, 166, 89-144. dal negro a., ungaretti l. (1971) refinement of the crystal structure of aragonite. american mineralogist, 56, 768-772. dettman d.l., reische a.k., lohmann k.c. (1999) controls on the stable isotope composition of seasonal growth bands in aragonitic fresh-water bi 11 mineralogy and oxygen isotope of pelecyora gigas 323. krantz d.e., williams d.f., jones d.s. (1987) ecological and paleoenvironmental information using stable isotope profiles from living and fossil molluscs. palaeogeography, palaeoclimatology, palaeoecology, 58, 249-266. lambeck k., rouby h., purcell a., sun y., sambridge m. (2014) sea level and global ice volumes from the last glacial maximum to the holocene. proceedings of the national academy of science, 111, 15296-15303. lawrence k.t., herbert t.d., brown c.m., raymo m.e., haywood a. m. (2009) high amplitude variations in north atlantic sea surface temperature during the early pliocene warm period, paleoceanography, 24, pa2218. lecointre g. (1952) recherches sur le néogène et le quaternaire marins de la côte atlantique du maroc. service geologique, notes et memoires. 99, 1 -198. le loeuff p., von cosel r. (1998) biodiversity patterns ofn the marine benthic fauna of the atlantic coast of tropical africa in relation to hydroclimatic conditions and paleogeographic events. acta oecologica, 19(3), 309-321. leng m. j., heaton t. h., lamb h. f., naggs f. (1998) carbon and oxygen isotope variations within the shell of an african land snail (limicolaria kambeul chudeaui germain): a high-resolution record of climate seasonality?. the holocene, 8(4), 407412. lisiecki, l.e., raymo m.e. (2005) a pliocenepleistocene stack of 57 globally distributed benthic δ18o records. paleoceanography, 20, pa1003. lisiecki, l.e., raymo m.e. (2007) plio-pleistocene climate evolution: trends and transitions in glacial cycle dynamics, quaternary science reviews, 26, 56-69. longinelli a., tongiorgi e., trevisan l. (1961) oxygen isotopic composition of some pelecypoda from two calabrian faunas. bollettino della società paleontologica italiana, 1, 1-6. malatesta a. (1970) malacofauna pliocenica umbra. memorie per servire alla descrizione della carta geologica d’italia, 13, pp. 498. marasti i., raffi s. (1980) extinction of polysyringian bivalves in the mediterranean pliocene. in: aavv, volume dedicato a sergio venzo, grafiche step parma, 107-115. martini i., aldinucci m. (2017) sedimentation and basin -fill history of the pliocene succession exposed in the northern siena-radicofani basin (tuscany, italy): a sequence-stratigraphic approach. rivista italiana di paleontologia e stratigrafia, 123(3), 407 -432. martini i., aldinucci m., foresi l.m., mazzei r., sandrelli f. (2011) geological map of the pliocene succession of the northern siena basin (tuscany, italy). journal of maps, 2011, 193-204. miller k.g., wright j.d., browning j.v., kulpecz a., kominz m., naish t.r., cramer b.s., rosenthal y., peltier r., sosdian s. (2012) high tide of the warm pliocene: implications of global sea level for antarctic deglaciation. geology, 40(5), 407-410. monegatti p., raffi s. (2001) taxonomic diversity and stratigraphic distribution of mediterranean pliocene bivalves. palaeogeography, palaeoclimatology, palaeoecology, 165(3-4), 171-193. monegatti p., raffi s. (2007) mediterranean-middle eastern atlantic façade: molluscan biogeography and ecobiostratigraphy throughout the late neogene. in: avila s.p., de frias martins am. (eds) proceedings of the first atlantic islands neogene, acoreana supplements, 5, 132-154. monegatti p., raffi s. (2010) the messinian marine molluscs record and the dawn of the eastern atlantic biogeography. palaeogeography, palaeoclimatology, palaeoecology, 297, 1-11. monegatti p., canali g., bertoldi r., albianelli a. (2002) the classical late piacenzian monte falcone-rio crevalese section (northern italy): palynological evidence and biomagnetostratigraphic constraints for climate cyclicity and local moolusc extinctions. geobios, m.s. 24, 219-227. mudelsee m., raymo m.e. (2005) slow dynamics of the northern hemisphere glaciation, paleoceanography, 20, pa4022. negri a., amorosi a., antonioli f., bertini a., florindo f., lurcock p. c., marabini s., mastronuzzi g., regattieri e., rossi v., scarponi s., taviani m., zanchetta g., vai g.b. (2015) a potential global stratotype section and point (gssp) for the tarentian stage, upper pleistocene, from the taranto area (italy): results and future perspectives. quaternary international, 383, 145-157. palla p. (1966) lamellibranchi pliocenici della bassa val d’elsa. rivista italiana di stratigrafia e paleontologia, 72(2), 397-458. patterson w.p., smith g.r., lohmann k.c. (1993) continental paleothermometry and seasonality using the isotopic composition of aragonite otoliths of freshwater fishes. in: swart, p.k., et al., (eds.), climatic change in continental isotopic records, geophysical monograph series., 78, 191-202. peres j.m., picard j. (1964) nouveau manuel de bionomie bentique de la méditerranée. recent travaux station marine d’endoume, 31, 1-137. petuch e.j. (2004) cenozoic seas: the view from eastern north america. crc press, boca raton, usa, pp. 328. pierre c. (1999) the oxygen and carbon isotope distribution in the mediterranean water masses. marine geology, 153, 41-55. raffi s. (1986) the significance of marine boreal molluscs in the early pleistocene faunas of the mediterranean area. palaeogeography, palaeoclimatology, palaeoecology, 52, 267-289. raffi s., monegatti p. (1993) bivalve taxonomic diversity throughout the italian pliocene as a tool for climatic oceanographic and stratigraphic inferences. ciencias da terra (unl) 12, 45-50. raffi s., stanley s.m., marasti r. (1985) biogeographic patterns and plio-pleistocene extinction of bivalvia in the mediterranean and southern north sea. 12 ragaini l. et al. paleobiology, 11, 368-388. raffi s., monegatti p., marasti r. (1989) east atlantic molluscan province boundaries and mediterranean neogene extinctions. in: di geronimo, i.s. (ed.), atti 3° simposio di ecologia e paleoecologia delle comunita` bentoniche, catania, 321-332. rohling e.j., foster g.l., grant k.m., marino g., roberts a.p., tamisiea m.e., williams f. (2014) sea-level and deep-sea-temperature variability over the past 5.3 million years. nature, 508, 477482. sarnthein m., pflaumann u., ross r., tiedemann r., winn k. (1992) transfer functions to reconstruct ocean palaeoproductivity: a comparison. in: summerhayes, c.p., prell, w.l., emeis, k.c. (eds.), upwelling systems: evolution since the earlymiocene, geologica society special publications, 63, 463-497. schöne b., rodland d.,wehrmann a., heidel b., oschmann w., zhang z., fiebig j., beck l.a. (2007) combined sclerochronologic and oxygen isotope analysis of gastropod shells (gibbula cineraria, north sea): life-history traits and utility as a high-resolution environmental archive for kelp forests. marine biology, 150, 1237-1252. shackleton n.j. (1987) oxygen isotopes, ice volume and sea level. quaternary science reviews 6, 183 -190. shakun j.d., lea d.w., lisiecki l.e., raymo m.e. (2015) an 800-kyr record of global surface ocean δ18oand implications for ice volume-temperature coupling. earth and planetary science letters, 426, 58-68. shimamoto m. (1986) shell microstructure of the veneridae (bivalvia) and its phylogenetic implications. tohoku university science reports, 56(1), 1-39. silva c.m. da, landau b.m., domènech r., martinell j. (2006) pliocene atlanto-mediterranean biogeography of patella pellucida (gastropoda, patellidae): palaeoceanographic implications. palaeogeography, palaeoclimatology, palaeoecology, 233 (3), 225-234. silva c.m. da, landau b.m., domènech r., martinell j. (2010) pliocene atlantic molluscan assemblages from the mondego basin (portugal): age and palaeoceanographic implications. palaeogeography, palaeoclimatology, palaeoecology, 285(3-4), 248254. stanley s.m. (1970) relation to shell form to life habit of bivalvia. geological society american memoirs, 125, pp. 296. stanley s.m. (1986) anatomy of a regional mass extinction: plio-pleistocene decimation of the western atlantic bivalve fauna. palaios, 1, 17-36. stanley s.m., ruddiman w.f. (1995) neogene ice age in the north atlantic region: climatic changes, biotic effects, and forcing factors. in: aavv, effects of past global change on life, national academy press, 118-133. tavani g., tongiorgi m. (1963) la fauna miocenica delle arenarie di ponsano. palaeontographia italica, 58, 1-41. vergnaud grazzini c. (1968) analyses isotopiques de faunes malacologiques plio-pléistocenes des environs de pise. vie et milieu, serie b, océanographie 19(2b), 233-272. vera-pelaez j.l., lozano-francisco m.c., muniz-solis r., gili c., martinell j., domènech r., palmqvist p., guerra-merchan a. (1995) estudio preliminar de la malacofauna del plioceno de estepona (málaga, españa). iberus,13, 93-117. wefer g., berger w.h. (1991) isotope paleontology: growth and composition of extant calcareous species. marine geology, 100, 207-248. white r.m.p., dennis p.f., atkison t.c. (1999) experimetnal calibration and field investigation of the oxygen isotopic fractionation between biogenic aragonite and water. rapid communication in mass spectrometry, 13, 1242-1247. zanchetta g., leone g., fallick a.e., bonadonna f.p. (2005) oxygen isotope composition of living land snail shells: data from italy. palaeogeography, palaeoclimatology, palaeoecology, 223, 20-33. 13 ms. received: july 20, 2018 final text received: january 8, 2019 mineralogy and oxygen isotope of pelecyora gigas 14 amq29(1) 1 zanchetta 05-18.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 29 (1), 2016, 5 17 the so-called “4.2 event” in the central mediterranean and its climatic teleconnections zanchetta giovanni1,2,3,4, regattieri eleonora4, isola iiaria3, drysdale russel n.5,6, bini monica1, baneschi ilaria2, hellstrom john c.7 1dipartimento di scienze della terra, pisa university, pisa, italy 2igg-cnr, pisa, italy 3ingvpisa, italy 4igag-cnr, rome, italy 5school of geography, university of melbourne, victoria, australia 6 université de savoie, laboratoire edytem, pôle montagne, le bourget du lac, france 7school of earth sciences, university of melbourne, victoria, australia corresponding author: g. zanchetta <zanchetta@dst.unipi.it> abstract: high-resolution isotopic analyses were performed on rl4 flowstone from renella cave (alpi apuane, central italy), a speleothem studied previously at low resolution. the new data are discussed together with recently obtained data from corchia and other localities in the central mediterranean, to elucidate the possible origin and regional articulation of a climatic event centred at ca. 4.0 ka. this analyses indicates that central to southern italy between ca 3.8 and 4.3 ka was characterized by drier conditions, whereas in northern italy the event seems less expressed or, as within the alps, marked by cooler and wetter conditions. several lines of evidence suggest that this event could be characterized by longer summer drought and possibly by little impact on precipitation during winter, even if this aspect needs to be explored in more detail. however, the event is particularly prominent in the northern sector of the african monsoon domain, which has been robustly linked to southward shifts in the itcz; whereas its occurrence is uncertain on northern european latitudes. however, many proxies indicate that there aridification probably started some centuries earlier and culminated at ca. 4.0 ka. taken as a whole, these data can be used to clarify the regional articulation of this event, but interpretations based on general circulation are still elusive. keywords: 4.2 event, speleothem, mediterranean, renella cave 1. introduction the mid-holocene was a time of profound worldwide climatic and cultural transformation in the human societies of the old world, particularly within the low latitudes (e.g. roberts et al., 2011; staubwasser and weiss, 2006). the end of the mid-holocene is often considered to be characterized by a widespread climatic event at around 4000 cal. yr bp, and it is used as formal boundary between middle and late holocene (walker et al., 2012). evidence for this climatic deterioration (also known as the “4.2 ka event”) has been widely recognized from the northern hemisphere (e.g. cullen et al., 2000; marchant & hooghiemstra, 2004; booth et al., 2005; drysdale et al., 2006). there is an increasing number of data supporting the notion that this climatic event also played an important role in the “collapse” of major ancient civilizations in india, china, egypt, mesopotamia and the mediterranean (e.g. weiss & bradley, 2001; staubwasser and weiss, 2006; zanchetta et al., 2013; dixit et al., 2014; welc & marks, 2014; and references therein). for instance, catastrophic floods seem to have occurred in the yellow river reaches, accompanied by severe drought that impacted local late neolithic settlements (liu & feng, 2012; huang et al., 2010, 2011), whereas a dramatic reduction in nile discharge and drought may have produced severe conditions in ancient egypt (e.g. welc & marks, 2014 and references therein). the change in nile flow and the channeling and drainage of the delta for agricultural purposes produced a shift from a river-dominated to a more waveinfluenced delta, chronologically placed at ca. 4000 yr cal bp (anthony et al., 2014). more classical is the idea of the “collapse” of the “akkadian empire” as related to drought at this time (weiss et al., 1993; cullen et al., 2000). in this paper we discuss the climatic changes that occurred at around 4 ka in the frame of new evidence recently collected in the central mediterranean and new high-resolution isotopic data from renella cave (apuan alps, northern tuscany, fig. 1). at renella, a lowresolution multiproxy record (drysdale et al., 2006) has already indicated an important phase of decrease cave recharge at ca. 4 ka. thanks to new high resolution data from renella and recently published multiproxy data from nearby corchia cave (regattieri et al., 2014a), we explore the possible correlations with highand lowlatitude proxy records for understanding the mechanisms behind the climatic changes at ca. 4 ka and their impact over the central mediterranean. 2. site description renella cave (44° 05’42’’ n, 10° 11’01’’ e) is a small, shallow cave located at the confluence of canale regolo and the frigido river in the alpi apuane (central italy, fig. 1). the cave, which opens at 275 m a.s.l., has a predominantly horizontal development, for a total 6 zanchetta g. et al. length of ca. 200 m (fig. 2a). it has formed in triassic metadolomite (grezzoni formation), close to the contact with the palaeozoic phyllitic basement. the metadolomite beds dip almost vertically, and cave development follows wsw direction of the strike (fig. 2a). the region experiences a mediterranean climate, with a predominantly north atlantic influence as for most of the apennines (lópez-moreno et al., 2011), and a mean annual precipitation of ca. 2000 mm (piccini et al., 2008). the mean annual temperature is ca. 13°c while mean monthly temperatures range from 23.1°c in july to 7.4°c in january (detailed information on internal cave stratigraphy can be found in zhornyak et al., 2011). 3. material and methods the flowstone rl4 (fig. 2b), collected in the upper level of the renella cave (fig. 2b) and previously studied at low resolution by drysdale et al. (2006), was micromilled at 200 µm increments using a micro-milling method (drysdale et al., 2012). the stable isotope composition of the powders was measured on co2 gas released by reaction with 105% h3po4 at 70°c, which was measured using an ap2003 mass spectrometer at the university of newcastle, australia. isotopic results are reported using the conventional δ-notation in per mille (‰), with reference to the vienna pee dee belemnite (v -pdb) standard. long-term analytical reproducibility (±1σ) was ±0.05‰ and ±0.10‰ for carbon and oxygen, fig. 1 reference map. a) location of palaeoclimatic records discussed in the text. b) geological sketch of the apuan alps. 7 the so-called “4.2 event” in the central mediterranean ... respectively. data are shown in fig. 3. an age model was obtained by interpolation between the previously published, low resolution, age model (drysdale et al., 2006) and the new, high resolution, depth series. more details on dating are available on drysdale et al. (2006) and zhornyak et al. (2011), including age correction for clastic contamination. for data comparison all records discussed in the text are reported to ad 2000. when discussing of the event at “4.2”, we generally intend the occurrence of a clear century-scale change in the proxy considered (i.e. prominent respect to the general trend) between ca. 3.8 and 4.2 ka, basically the range of ages of this event inferred from renella cave (see below). following the study by drysdale et al. (2006), a discontinuous monitoring program was undertaken in the cave including cave water samples (drips, pools) for isotopic analyses. preliminary data that are relevant for the purpose of the present study are also presented. the stable isotopic composition of water samples was determined at the iggcnr stable isotope laboratory in pisa. the δ18o of the water was determined after equilibration with co2 (epstein and mayeda, 1953). the isotopic measurements were made on a thermofinnigan mat-252 mass-spectrometer. the iso fig. 2 a) geological section of the renella cave. the rl4 position is also shown; b) rl4 section with u/th dating position (drysdale et al., 2006; zhornyak et al., 2011). fig. 3 a) carbon isotope composition of rl4 vs age; b) oxygen isotope composition vs age; c) [230th/232th] measured in rl4 (drysdale et al., 2006). 8 tab. 1 isotopic data for waters collected in the renella cave. topic composition of hydrogen (δ2h) was determined by means of the h2 generated by hydrolysis of water using zn (modified after coleman et al., 1982) and analysed by a geo20-20 massspectrometer (europa scientifìc). results are reported as δ values in units of parts per thousand (‰) relative to the vsmow (viennasmow) standard. data are reported in fig. 4 and table 1. 4. results and proxies interpretation figure 3 shows the new highresolution δ18o and δ13c record from rl4 flowstone. δ13c and δ18o show some correlation (r2=0.33). in fig. 3 the [230th/232th] activity ratio is also shown (drysdale et al., 2006; zhornyak et al. 2011). the ratio between radiogenic and detrital th indicates that ages around 4 ka has the lowest amount of clastic contamination. this shows that ages around this period have low correction and can be considered particularly precise and accurate. in addition it suggests a decrease of transport of clastic material from the catchment to the cave. the new record shows a prominent increase in the δ18o centered at ca. 4 ka and lasting ca. 0.5 ka, accompanied by a concurrent increase in δ13c. higher δ18o on the apuan alps calcite speleothem, in absence of large changes in the water composition of the oceans, are interpreted as due to decrease in precipitation (drysdale et al., 2007; zanchetta et al., 2007; regattieri et al., 2014a, b). interpretations of speleothem δ13c records are more challenging because of the complex reactions involving soil co2, bedrock dissolution, and the reaction kinetics in the co2-h2o-caco3 system (e.g. fairchild and baker, 2012). many processes, however, tend to drive the final δ13c of speleothem in the same direction, at least in the middle latitudes. elevated values of speleothems can be due to a decrease in soil-co2 productivity (e.g. genty et al., 2003), usually associated with a reduction in rainfall and cooler climate. reduction in recharge can also produce degassing along the fracture paths, with enhanced calcite precipitation occurring before drip waters reach the cave (e.g. baker et al., 1997). other effects can occur, like changes in the rate in the mineralization of labile vs. recalcitrant organic matter into the soil (rudzka et al., 2011). fig. 4 isotopic composition (hydrogen and oxygen) of renella cave waters. the regional meteoric water line is also reported (mussi et al., 1998) zanchetta g. et al. 5. discussion regional expression of the 4.2 event figure 5 shows the comparison with the corchia mean anomaly record (regattieri et al., 2014a), obtained by combining trace elements (mg/ca molar ratio) and stable isotopes results into an indicator of moisture levels in the cave recharge system. both records indicate a clear decrease in the cave recharge starting at ca. 4.3 and ending at ca. 3.8 ka, therefore, lasting ca. 500 yr. the δ18o from rl4 seems to indicate that drying may have started ca. 2 centuries earlier (ca. 4.5 ka), ending abruptly at 3.8 ka. at corchia the tendency is less evident, and there is no evidence of the abrupt termination (fig. 5). this would be due to the extremely different cave settings, with deep and large corchia cave system slowly responding, compared to smaller and shallower caves like renella, a fact also noted comparing corchia record with that from another small cavity on the apuan alps, the tana che urla cave (regattieri et al., 2014b). interestingly, the event centered at 4 ka is not clearly expressed in the oxygen isotopic composition of cc26, but appears more prominent in the trace element data (regattieri et al., 2014a), a point to which we return later. regionally, the lake record from accesa (southern tuscany, fig. 1, magny et al., 2007) shows a dramatic increase of lake level at ca. 4.6 ka, culminating at ca. 4.2 ka, followed by a short event of lake level drop between ca. 4-4.1 ka (fig. 5). it is worth noting that the age model of accesa record was partly based on tephrochronology (magny et al., 2007). in particular, the pomici di avellino tephra, from vesuvius, was recognized and an age of 4.3 ka was attributed to it. however, considering the current well established age for pomici di avellino eruption, i.e., ca. 3.8 ka (passariello et al. 2009, zanchetta et al., 2011; sevink et al., 2011), a shift of the prominent low lake level centered at ca. 4.6-4.7 ka in the original age model (magny et al., 2007) to ca. 4.1 ka, is required. with this new chronology, the accesa record would show a prominent lake level lowering within the range of age of corchia and renella reduction in cave recharge (fig. 5). several italian pollens succession also record a distinct opening of the forest around this time (sadori & nar 9 fig. 5 a) δ18o records from rl4 flowstone; b) mean anomaly index for cc26 stalagmite from corchia cave (regattieri et al., 2014a); c) lake level from accesa (magny et al., 2007). note the position of avellino tephra, reported with its correct age, and the chronology of the record. d) shkodra δ18o record (zanchetta et al., 2012b); e) pollen from alimini piccolo lake (di rita & magri, 2009). for site location refers to fig. 1. the so-called “4.2 event” in the central mediterranean ... cisi, 2001; magri & parra, 2002; di rita & magri, 2009; sadori et al., 2011), even if the chronology of this event in these pollen records is not always well constrained (di rita & magri, 2009; zanchetta et al., 2012a). as an example, poorly dated pollen successions from alluvial deposits facing the apuan alps indicate an opening of vegetation occurring roughly at this age as well as changes in fluvial activity (bini et al., 2015; sarti et al., 2015). a well-dated pollen record for this period is represented by lake alimini piccolo (di rita & magri, 2009), in southern italy (fig. 1) where a clear opening of the forest accompanied by a strong decrease in quercusdominated evergreen vegetation is recorded between 4.3 and 3.8 ka (fig. 5). interestingly, neither reliable anthropogenic pollen markers nor increasing trends in the charcoal curve are found at this time in the alimini record, suggesting no relationships of this deforestation phase with human activity (di rita e magri, 2009). the δ18o record from lake shkodra (albania/montenegro, zanchetta et al., 2012b, fig. 1) indicates a short and rapid drier phase at ca. 4.1 cal ka bp, preceded by a pronounced wetter period (fig. 5). at shkodra, this drying event is bracket by two tephra layers: avellino from somma-vesuvius and agnano pomici principali from campi flegrei (zanchetta et al., 2012b). this tight tephrostratigraphic constraint has allowed us to define the beginning of this important climatic deterioration over the apennine as coincident with the start of re-growth of the calderone glacier (abruzzo, central italy) (giraudi et al., 2011; zanchetta et al., 2012a). in addition, zanchetta et al. (2000) found a drastic change in the isotopic composition of pedogenic carbonate in the campania region again between agnano mt. spina and avellino tephras, and interpreted this change as a temperature lowering of ca. 2°c. however, the pedogenic carbonate record is, by definition, rather discontinuous and from this record no precise consideration can be made on the duration of this period of climatic deterioration. a short, prominent δ18o positive peak at this time is found also in the record from lake dojran (francke et al., 2015), confirming that this event is also traceable in the balkans region (fig. 5). 10 fig. 6 correlation for δ18o record of rl4 record (a) with soreq δ18o record (data from barmatthews & ayalon 2011) (b); δ18o record sofular cave (göktürk et al., 2011) (d); fe content from marine core md5-27 (revel et al., 2010) (e); percentage of marine warm foraminifera species in core lc21 (rohling et al., 2002). the position of thera tephra (now dated at ca. 3.6 cal ka bp) is also reported. zanchetta g. et al. from the eastern mediterranean, it is interesting the correlation with soreq cave (fig. 6, bar-matthews et al., 1996, 1999; bar-matthews & ayalon 2011). here the δ18o record, which is interpreted similarly to alpuan alps (i.e., affected by strong hydrological imprint), shows a long-term trend with an inferred progressive drying since ca. 4.7 ka, with poorly expressed phases of higher δ18o centered at 4.2, 4 and 3.8 ka. however, in contrast with renella, the isotopic values at soreq never returned at the previous values. in the ne of mediterranean climate boundaries, sofular cave isotopic records (fig. 1, göktürk et al., 2011) show a quite different situation (fig. 6). here the δ13c record, which is considered the best hydrological indicator (göktürk et al., 2011), shows a progressive decreasing since ca. 4.5 culminating at ca. 3.8 ka. according to the interpretation of göktürk et al., (2011) this would indicate a progressive increase of cave recharge (i.e. increasing of precipitation) and/or temperature. towards northern italy, δ18o record from grotta savi (figs. 1, 7) does not show particular changes at that time (frisia et al., 2005), similar to the δ18o record from grotta di ernesto (scholz et al., 2012). at savi, a dependance of δ18o on temperature is suggested (frisia et al., 2005), therefore no significant temperature changes at that time seem to be recorded. similarly no significant changes are observed at grotta di ernesto (scholz et al., 2012), although the dependence of the δ18o with temperature/amount of rainfall is less clear. at spannagel cave, the δ18o record (also called comnispa ii, fig. 1, fohlmeister et al., 2013) shows a long-term trend of increasing values, culminating between ca. 3.9 and 4.2 ka. the δ18o variations during the holocene are seen as principally due to the response in temperature (mangini et al., 2006; vollweiler et al., 2006, fohlmeister et al., 2013), even if this link is probably complex. therefore, it seems to indicate a decrease in temperature over the ne alps for the period considered. at lago di ledro (fig. 1), lake-level oscillations reconstructed by magny et al. (2012) indicate a prominent high stand between 3.8 and 4.5 ka, interrupted by a short and poorly pronounced low lake level at 4.0 ka. at lake frassino, the relatively low resolution of the δ18o records does not allow to infer particular trends at that time (baroni et al., 2006). overall, the presented archives show a regionally complex climate pattern. some archives indicate increasing humidity and probably colder conditions for northern italy and the alps, even if invariant conditions appear to be recorded in other archives in the southern alps. over the alps, glaciers seem to advance in a period roughly centred at ca. 4 ka (see figure 4 of wanner et al., 2008 and references therein), whereas centralsouthern italy and the southern balkans show a marked drier phase. although very few records are considered here, turkey and, in general, eastern mediterranean climatic patterns at that time are more complex. finné et al. (2011) report a compilation of many records from this part of the mediterranean, concluding that although aridity was widespread around 4200 yrs bp in the eastern mediterranean region, there is not enough evidence to support the notion of a single climate event with rapidly drying conditions in the region. part of this complexity can arise from discrepancy in age models. indeed, in some cases it is indisputably demonstrated that differences in age models between archives are too large to ensure the precise correlation of events (zanchetta et al., 2011; 2012ab). this also impacts our estimation on the duration of the event in different records. on the other hand, our understanding of proxy records in some case is incomplete. for instance, there could be an excessive use of pollen data for some regions, like the records used by finné et al. (2011) for inferring past precipitation and temperature regime. this because the human impacts on the natural environment and vegetation since the neolithic likely reduced the reliability of these climatic reconstructions (e.g. roberts et al., 2004, 2008, 2010). connection between lower and high latitudes according to the re-analyses and review of globally distributed proxy records, wanner et al. (2011) failed to clearly identify a prominent event between ca. 3.8 and 4.2 ka. similarly, a compilation and re-analyses of several different proxy data sets from the scandinavia region (seppä et al., 2009) revealed no significant changes for the period considered, whereas a prominent cooling and wetter conditions appear to have occurred between 3800 and 3000 yr cal bp. detailed studies from peat-based records in great britain and ireland suggest no regionally coherent, prolonged phase of wetter and/or colder climatic conditions associated with a 4.2 ka event in great britain and ireland (roland et al., 2014). according to roland et al. (2014), and consistent with the finding of seppä et al. (2009), the lack of a coherent 4.2 ka event in great britain and ireland implies that the dominant forcing mechanisms of the period of change may not lie in the north atlantic, or at least that any atmospheric-oceanic circulation changes in the region may not have been severe enough to register change in the peatland archives. indeed, only a modest increase of ice rafted debris in the subpolar north atlantic occurs at the time (bond et al., 1997). comparison of the renella and corchia records with the hólmsá loess profile in iceland (jackson et al., 2005), where grain size is regarded as a proxy for the strength of westerly flow, indicates that at ca. 4 ka westerly wind strength was generally low in the higher latitudes of europe (fig. 8). this suggests that the portion of vapor originating in the north atlantic and responsible in part for cyclogenesis in the western mediterranean, particularly over genoa gulf and apuan alps (reale and lionello, 2013), was not particularly reduced (fletcher et al., 2013; zanchetta et al., 2014), at least during winter. considering the negative relation between meteoric precipitation over apennine and north atlantic pressure patterns (lópez-moreno et al., 2011), this would indicate that a convincing explanation for a decrease in the recharge in the apuan alps is not related to changes in winter conditions. on the other hand, when westerlies in northern europe are weak (weaker zonal flow), this allows the penetration of arctic air into the middle latitudes and may favor colder conditions in the alps, allowing glaciers to advance. this cooling can also reduce the sea temperatures for a longer period of time, reducing the amount of evaporation in the following seasons. 11 the so-called “4.2 event” in the central mediterranean ... longer summers (basically at the expense of spring and autumn seasons) compared to winter, can affect the isotopic budget of our caves, and can additionally help in explaining our isotopic records. it is well known that, at middle latitudes, summer precipitations have higher isotopic composition (fricke & o’neil 1999), and in these conditions (i.e. enhanced summer heating related to cloud-free weather) it is likely that the western mediterranean can supply a more evaporation-affected component to the precipitation, producing precipitation with higher isotopic composition (celle-jeanton et al., 2001). 12 fig. 8 comparison among renella rl4 δ18o record (a, this paper), cc26 mean anomaly index (regattieri et al., 2014a, b), δ18o record of cc26 (corchia cave, zanchetta et al., 2007, c), and hòlmsà grain-size records (jackson et al., 2005, d). previously, di rita & magri (2009) and zanchetta et al. (2011) have suggested that this event may have been characterized by long summer drought due to a progressive persistence of the azores high over the western mediterranean instead of significant changes during winter. this can be indirectly supported by pollen evidence (di rita & magri, 2009), which suggests changes in the prevailing winds based on the presence of cedrus pollen grains in the latium pollen succession, indicative of a likely source from north africa (magri & parra, 2002). zanchetta g. et al. so, along with a decrease in total precipitation, during summer these resulted 18o enriched. in this frame, we return to the question of why the isotopic composition of cc26 from corchia lacks a significant expression of reduced precipitation, which on the contrary is so evident in the rl4 record and in the corchia multi-proxy index. renella is a small cave where drips show a seasonal variability not evident in the drips of corchia, which has a very deep, well-mixed plumbing system (piccini et al., 2008; baneschi et al., 2011; fig. 4). on the other hand, trace elements at corchia are more affected by re-routing effects, changes in residence time and mixing than by the same factors that affect the isotopic composition of drips (regattieri et al., 2014a). therefore, if for some reason calcite precipitation in renella is skewed towards summer conditions, this will immediately affects the isotopic signal, whereas in corchia this would be dampened by mixing of the plumbing system dominated by winter recharge. it is also possible that higher altitude cave site was less susceptible to reduced rainfall and only records a modest reduction, compared to renella. however, the strong orographic effect offered by apuan alps should prevent this (piccini et al., 2008). indirect evidence that an event at ca. 3.8-4.2 ka in the mediterranean is more pronounced in proxy records susceptible to changes in summer rather than changes in winter precipitation is provided by the paleoclimatic record of core lc21 in the aegean sea (fig. 1, rohling et al., 2002), although the resolution is quite low compared to the interval of interest. in the lc21 record there is no evidence of the 4.2 ka event in the percentage of warm-water foraminifera species, which are interpreted as indicators of winter temperatures affected by the incursion of cold air masses from siberia (fig. 6). the proxy record of fig. 6 is believed to be indicative of the winter temperature (rohling et al., 2002). note that the position of the thera tephra in the lc21 record, now radiocarbon dated at ca. 3.6 cal ka bp (friedrich et al., 2006; manning et al., 2006) rules out the possibility of confusion between the 4.2 ka event and the prominent event at ca. 3.4-3.6 ka bp (zanchetta et al., 2011). this is consistent with the notion that the 4.2 ka event is not particularly prominent in proxies indicating winter temperature. at lower latitudes the presence of dust spikes in the arabian sea and in kilimanjaro ice cores is strongly suggestive of aridification due to changes in the position of the intertropical convergence zone -itcz(cullen et al., 2000; thompson et al., 2002). marshall et al. (2011) reported recently a substantial long-term drying for lake tana, the source of the blue nile, culminating in a low stand at ca. 4.2 ka, interpreted as driven by a progressive southward shift of the itcz during summer. according to the ti concentrations, used as a proxy for the clastic input within the lake and thus as an indirect measure of summer monsoon intensity, detrital influx started to decrease well before at ca. 4.8-4.9 ka. a major dry spell is also documented at 4.2-4.0 ka bp in the northern monsoon domain of africa as reported in lake level and stable isotopes data from many lakes (gasse, 2000). also, the high-resolution fe record from ms27pt marine core recovered in hemipelagic sediments deposited on the nile margin (revel et al., 2010) is considered a proxy for the east african monsoon regime intensity over ethiopia. this record (fig. 6) shows a consistent drop at ca. 4.3 ka, which never recovered afterwards, which indicates a reduction in the monsoon intensity and blue nile recharge at that time. so, generally at ca. 4.3-4.5 ka in africa a progressive southward shift of the itcz seems to occur, reaching a maximum of drying at ca. 4.2-4.0 ka bp. this event seems progressively recorded in the mediterranean and in particular in central mediterranean. the role of the itcz and african monsoon systems onto the summer conditions over the mediterranean is well known from instrumental data and modelling (e.g. gaetani et al., 2011) and it is supposed for millennial-scale events (e.g. tzedakis, 2007; sanchez-goni et al., 2008; regattieri et al., 2015). however, to find a precise mechanisms linking weakening and southward shift of african summer monsoon, evidence of increasing summer drought and/or southern circulation over central mediterranean without significant changes in the north europe is not an easy task. the 4.2 ka event was most likely caused by a complex set of interactions within the global ocean-atmosphere circulation system. booth et al. (2005), starting from current meteorological observation, has noted that widespread midlatitude and subtropical drought, associated with increased moisture at some high latitudes (however, not verified for the 4.2 event), has been linked in the instrumental record to an unusually steep sea-surface temperature gradient between the tropical eastern and western pacific ocean (la niña) and increased warmth in other equatorial oceans. similar sst patterns may have occurred at 4.2 ka, possibly associated with external forcing or amplification of these spatial modes by variations in solar irradiance or volcanism. in particular, booth et al. (2005) suggested a link with multidecadal atlantic oscillation (a mode of variability occurring in the north atlantic ocean that has its principal expression in the sea surface temperature field). however, boundary conditions at that time were probably different, with the oceanic polar front in the north atlantic displaced southwards as suggested by ird distribution (bond et al., 1997). magny et al. (2013) have suggested that the major palaeohydrological oscillation around 4500-4000 cal bp may be a non-linear response to the gradual decrease in insolation, with additional key seasonal and interhemispheric changes. we can conclude that, despite the geographical articulation of the event at 4.2 ka become much clear, the mechanisms behind this event remain elusive. 6. concluding remarks abrupt changes are part of natural climate variability and their investigation is fundamental for understanding the underlying driving factors, their potential impact and the projection of future climatic changes. the so-called “4.2 event” is of particular interest for its possible impact on past ancient civilizations. revision on new data from renella and corchia caves and other data from the central mediterranean indicate that in central to southern 13 the so-called “4.2 event” in the central mediterranean ... italy this event is characterized by drier conditions, whereas in northern italy the event seems less expressed or, for example over the alps, could be characterized by cooler, wetter conditions. several lines of evidence suggest that this event would be characterized by a longer summer drought with possibly little impact on precipitation during winter, even if this aspect needs to be explored in more detail in the future, looking at different proxies. this event is particularly prominent in the african northern monsoon domain, which has been robustly linked to southward shift of the itcz, whereas the presence is uncertain on northern european latitudes. the composition of this climatic puzzle is still open and the mechanism behind this event still remains elusive. acknowledgments we thank federazione speleologica toscana for the long support in the speleothem research in the last 15 years. part of this work has been financially supported by university of pisa (fondi di ateneo, g. zanchetta) and the australian research council (dp0773700), ingv-pisa and igg-cnr-pisa. suggestions from b. giaccio and m. magny improved the final version of the manuscript. we thank d. magri and f. di rita for the pollen data of alimini piccolo. references anthony e.j., marriner n., morhange c. (2014) human influence and the changing geomorphology of mediterranean deltas and coasts over the last 6000 years: from progradation to destruction phase? earth-science reviews, 139, 336-361. baker a., ito e., smart p., mcewan r. (1997) elevated and variable values of δ13c in speleothems in a british cave system. chemical geology, 136, 263270. baneschi i., piccini l., regattieri e., isola i., guidi m., lotti l., mantelli f., menichetti m., drysdale r.n., zanchetta g. (2011) hypogean microclimatology and hidrology of the 800-900 m.a.s.l. in the monte corchia cave (tuscany, italy): prleiminary considerations and implications for paleoclimatological studies. acta carsologica, 40 (1), 175-187. bar-matthews m., ayalon a. (2011) mid-holocene climate variations revealed by high-resolution speleothems records from soreq cave, israel and their correlation with cultural changes. the holocene, 21, 163-171. bar-matthews m., ayalon a., matthews a., sass e., halicz l. (1996) carbon and oxygen isotope study of the active water-carbonate system in a karstic mediterranean cave: implications for paleoclimate research in semiarid regions. geochimica et cosmochimica acta, 60, 337-347. bar-matthews m., ayalon a., kaufman a., wasserburg g.j. (1999) the eastern mediterranean paleoclimate as a reflection of regional events: soreq cave, israel. earth planetary science letters, 166, 85-95. baroni c., zanchetta g., fallick a.e., longinelli a. 2006. molluscs stable isotope record of a core from lake frassino (northern italy): hydrological and climatic changes during the last 14 ka. the holocene, 16, 827-837. bini m., rossi v., amorosi a., pappalardo m., sarti g., noti v., capitani m., fabiani f., gualandi m. l., (2015) palaeoenvironments and palaeotopography of a multilayered city during the etruscan and roman periods: early interaction of fluvial processes and urban growth at pisa (tuscany, italy). journal of archaeological science, 59, 197-210. bond g., showers w., cheseby m., lotti r., almasi p., demenocal p., priore p., cullen h., hajdas i., bonani, g. (1997) a pervasive millennial scale cycle in north atlantic holocene and glacial climates. science, 278, 1257-1266. booth r.k., jackson s.t., forman s.l., kutzbach j.e., bettis iii e.a., kreig j., wright d. k. (2005) a severe centennial-scale drought in midcontinental north america 4200 years ago and apparent global linkages. the holocene, 15, 321-328. celle-jeanton h., travi y., blavoux b. (2001) isotopic typology of the precipitation in the western mediterranean region at three different time scales. geophysical research letters 28, 1215-1218. coleman m.l., shepherd t.j., durham j.j., rous j.e., moore g.r. (1982) reduction of water with zinc for hydrogen isotope analysis. analytical chemistry, 54, 993-995. cullen h.m., demenocal p., hemming s., hemming g., brown f.h., guilderson t., sirocko f. (2000) climate change and the collapse of the akkadian empire: evidence from the deep sea. geology, 28, 379-382. di rita f., magri d. (2009) holocene drought, deforestation and evergreen vegetation development in the central mediterranean: a 5500 year record from lago alimini piccolo, apulia, southeast italy. the holocene, 19, 295-306. dixit y., hodell d.a., petrie c.a. (2014) abrupt weakening of the summer monsoon in northwest india ~4100 yr ago. geology, 42, 339-342. drysdale r.n., zanchetta g., hellstrom j., maas r., fallick a.e., pickett m., cartwright i., piccini l. (2006) late holocene drought responsible for the collapse of old world civilizations is recorded in an italian cave flowstone. geology, 34, 101-104. drysdale r.n., zanchetta g., hellstrom j., fallick a.e., mcdonald j., cartwright i. (2007) stalagmite evidence for the precise timing of the north atlantic cold events during marine isotope stage 5d. geology, 35, 77-80. drysdale r.n., paul b.t., hellstrom j.c., couchoud i., greig a., bajo p., zanchetta g. isola, i., spötl c., baneschi i., regattieri e., woodhead j.d. (2012) precise microsampling of poorly laminated speleothems for u-series dating. quaternary geochronology, 14, 38-47. epstein s., mayeda t. (1953) variation of o18 content of waters from natural sources. geochimica et cosmochimica acta. 4, 213-224. fairchild i.j., baker a. (2012) speleothem science. from processes to past environments. quaternary geosciences series. wiley-blackwell, pp. 370. 14 zanchetta g. et al. finné m., holmgren k., sundqvist h.s., weiberg e., lindblom m. (2011) climate in the eastern mediterranean, and adjacent regions, during the past 6000 years a review. journal of archaeological science, 38, 3153-3173. fletcher w.j., debret m., sanchez goni m.f. (2013) holocene emergence of a low frequency millennial oscillation in western mediterranean climate: implications for past dynamics of the north atlantic atmospheric westerlies. the holocene, 23, 153166. fohlmeister j., vollweiler n., spötl c., mangini a. (2013) comnispa ii: update of a mid-european isotope climate record, 11 ka to present. the holocene, 23(5) 749-754. francke a., wagner b., just j., leicher n., gromig r., baumgarten h., vogel h., lacey j.h., sadori l., wonik t., leng m. j., zanchetta g., sulpizio r., giaccio b. (2015). sedimentological processes and environmental variability at lake ohrid (macedonia, albania) between 640 ka and present day. biogeosciences discussion, 12, 1511115156. fricke h. c., o’neil j. r. (1999) the correlation between 18o/16o ratios of meteoric water and surface temperature: its use in investigating terrestrial climate changeover geologic time. earth and planetary science letters, 170,181-196. friedrich w.l., kromer b., friedrich m., heinemeier j., pfeiffer t., talamo s. (2006) santorini eruption radiocarbon dated to 1627–1600 b.c. science, 312, 548. frisia s., borsato a., spötl c., villa i.m., cucchi f. (2005) climate variability in the se alps of italy over the past 17000 years reconstructed from a stalagmite record. boreas, 34, 445-455. gaetani m., pohl b., douville h., fontaine b. (2011) west african monsoon influence on the summer euro-atlantic circulation. geophysical research letters, 38, l09705, doi:10.1029/2011gl047150. gasse f. (2000) hydrological changes in the african tropics since the last glacial maximum: quaternary science reviews, 19, 189-211. genty d., blamart d., ouahdi r., gilmour m., baker a., jouzel j., van-exter s. (2003) precise dating of dansgaard-oeschger climate oscillations in western europe from stalagmite data. nature, 421, 833 -837. giraudi c., magny m., zanchetta g., drysdale n.r. (2011) the holocene climatic evolution of the mediterranean italy: a review of the geological continental data. the holocene, 21, 105-115. göktürk o.m., fleitmann d., badertscher s., cheng h., edwards r.l., leuenberger m., fankhauser a., tüysüz o., kramers j. (2011) climate on the southern black sea coast during the holocene: implications from the sofular cave record. quaternary science reviews, 30, 2433-2445. huang c.c., pang j.l., zha x.c., zhou y.l., su h.x., li y.q. (2010) extraordinary floods of 4100-4000 a bp recorded at the late neolithic ruins in the jinghe river gorges, middle reach of the yellow river, china. palaeogeography, palaeoclimatoplogy, palaeoecology 289, 1-9. huang c.c., pang j.l., zha x.c., su h.x., jia y. (2011) extraordinary floods related to the climatic event at 4200 a bp on the qishuihe river, middle reaches of the yellow river, china. quaternary science reviews, 30, 460-468. jackson m.g., oskarsson n., tronnes r.g., mcmanus j.f., oppo d.w., grönvold k., hart s. r., sachs j.p.(2005) holocene loess deposition in iceland: evidence for millennial-scale atmosphere–ocean coupling in the north atlantic. geology, 33, 509512. liu f., feng z. (2012) a dramatic climatic transition at ~4000 cal.yr bp and its cultural responses in chinese cultural domains. the holocene, 22, 11811197. lópez-moreno j. i., vicente-serrano s. m., morántejeda e., lorenzo-lacruz j., kenawy a., beniston m. (2011) effects of the north atlantic oscillation (nao) on combined temperature and precipitation winter modes in the mediterranean mountains: observed relationships and projections for the 21st century. global and planetary change, 77 (1), 62-76. magny m., de beaulieu j.l., drescher-schneider r.,vannière b., walter-simonnet a.v., miras y., millet l.,bossuet g., peyron o., brugiapaglia e., leroux, a. (2007) holocene climate changes in the central mediterranean as recorded by lakelevel fluctuations at lake accesa (tuscany, italy). quaternary science reviews, 26, 1736-1758. magny m., joannin s., galop d., vannière b., haas j.n., bassetti m. bellintani p., scandolari r., desmet m. (2012) holocene palaeohydrological changes in the northern mediterranean borderlands as reflected by the lake-level record of lake ledro, northeastern italy. quaternary research, 77, 382-396. magny, m., combourieu-nebout, n., de beaulieu, j. l., bout-roumazeilles, v., colombaroli, d., desprat, s., francke a., joannin s., peyron o., revel m., siani g., sicre m.a., samartin s., simmonneau a., tinner w., vanniere b., wagner b., zanchetta g., anselmetti f., brugiapaglia e., chapron e., debret m., desmet m., didier j., essallami l., galop d., gilli a., haas j.n., kallel n., millet l., stock a., turon j.l., wirth, s. (2013). north-south palaeohydrological contrasts in the central mediterranean during the holocene: tentative synthesis and working hypotheses. climate of the past discussions, 9, 1901-1967. magri d., parra i. (2002) late quaternary western mediterranean pollen records and african winds. earth and planetary science letters, 200, 401408. mangini a., verdes p., spötl c., scholz d., vollweiler n., kromer b. (2006) persistent influence of the north atlantic hydrography on central european winter temperature during the last 9000 years. geophysical research letters, 34, l02704, doi:10.1029/2006gl028600. manning s.w., bronk ramsey c., kutschera w., 15 the so-called “4.2 event” in the central mediterranean ... higham t., kromer b., steier p. et al. (2006) chronology for the aegean late bronze age 1700 -1400 bc. science, 312, 565-569. marchant r., hooghiemstra h. (2004) rapid environmental change in african and south american tropics around 4000 years before present: a review. earth science reviews, 66, 217-260. marshall m.h., lamb h.f., huws d., davies s.j., bates r., bloemendal j., boyle j., leng m.j., umer m., bryant c. (2011) late pleistocene and holocene drought events at lake tana, the source of the blue nile. global and planetary change, 78, 147161. mussi m., leone g., nardi i. (1998) isotopic geochemistry of natural waters from the alpi apuanegarfagnana area, northern tuscany, italy. mineral. petrograph. acta, 41, 163-178. passariello i., albore livadie c., talamo p., lubritto c., d'onofrio a., terrasi f. (2009) 14c chronology of avellino pumices eruption and timing of human reoccupation of the devasted region. radiocarbon, 51, 1-14. piccini l., zanchetta g., drysdale r.n., hellstrom j., isola i., fallick a.e., leone g., doveri m., mussi m., mantelli f., molli g., lotti l., roncioni a., regattieri e., meccheri m., vaselli l. (2008) the environmental features of the monte corchia cave system (apuan alps, central italy) and their effects on speleothems growths. international journal of speleology, 37(3), 153-173. reale m., lionello p. (2013) synoptic climatology of winter intense precipitation events along the mediterranean coasts. nat. hazards earth syst. sci., 13, 1707-1722. regattieri e., zanchetta g., drysdale r.n., isola i., hellstrom j.c., dallai l. (2014a) lateglacial to holocene trace element record (ba, mg, sr) from corchia cave (apuan alps, central italy): paleoenvironmental implications. journal of quaternary science, 29, 381-392. regattieri e., zanchetta g., drysdale r.n., isola i., hellstrom j.c., roncioni a. (2014b) a continuous stable isotopic record from the penultimate glacial maximum to the last interglacial (160 to 121 ka) from tana che urla cave (apuan alps, central italy). quaternary research, 82, 450-461. regattieri e., giaccio b., zanchetta g., drysdale r.n., galli p., nomade s., peronace e., wulf s. (2015) hydrological variability over apennine during the early last glacial precession minimum, as revealed by a stable isotope record from sulmona basin, central italy. journal quaternary science, doi: 10.1002/jqs.2755. revel m., ducassou e., grousset f.e., bernasconi s.m., migeon s., revillon s., mascle j., murat a., zaragosi s., bosch d. (2010) 100,000 years of african monsoon variability recorded in sediments of the nile margin. quaternary science reviews, 29, 1342-1362. roberts n., stevenson a.c., davis b., cheddadi r., brewer s., rosen a. (2004) holocene climate, environment and cultural change in the circummediterranean region. in: battarbee, r.w., gasse, f., stickley, c. (eds.), past climate variability through europe and africa. kluwer, dordrecht, 343 -362. roberts n., jones m.d., benkaddur a., eastwood w.j., filippi m.l., frogley m.r., lamb h.f., leng m.j., reed j.m., stein m., stevens l., valerogarcè b., zanchetta g. (2008) stable isotope records of late quaternary climate and hydrology from mediterranean lakes: the isomed synthesis. quaternary science review, 27, 2426-2441. roberts c.n., zanchetta g., jones m.d. (2010) oxygen isotopes as tracers of mediterranean climate variability: an introduction. global and planetary change, 71, 135-140. roberts n., eastwood w.j., kuzucuoðlu c., fiorentino g., caracuta v. (2011) climatic, vegetation and cultural change in the eastern mediterranean during the mid-holocene environmental transition. the holocene, 21, 147-162. rohling e.j., mayewsky p.a., hayes a., abu-zied r.h., casford j.s.l. (2002) holocene atmosphere– ocean interactions: records from greenland and the aegean sea. climate dynamic, 18, 587-593. roland t.p., caseldine c.j., charman d.j., turney c.s.m., amesbury m.j. (2014) was there a ‘4.2 ka event’ in great britain and ireland? evidence from the peatland record. quaternary science reviews, 83, 11-27. rudzka d., mcdemott f., baldini l.m., fleitmann d., moreno a., stoll h. (2011) the coupled δ13cradiocarbon systematics of three late glacial/early holocene speleothems; insights into soil and cave processes at climatic transitions. geochimica et cosmochimica acta, 75, 4321-4339. sadori l., narcisi b. (2001) the postglacial record environmental history from lago di pergusa. the holocene, 11, 655-670. sadori l., jahns s., peyron o. (2011) mid-holocene vegetation history of the central mediterranean. the holocene, 21, 117-129. sanchez goni m.f., landais a., fletcher w.j., naughton f., desprat s., duprat j. (2008) contrasting 789 impacts of dansgaard–oeschger events over a western european latitudinal transect modulated by 790 orbital parameters. quaternary science reviews, 27, 1136-1151. sarti g., rossi v., amorosi a., bini m., giacomelli s., pappalardo m., ribecai c., ribolini a., sammartino i. (2015) climatic signature of two mid-late holocene fluvial incisions formed under sea-level highstand conditions (pisa coastal plain, nw tuscany, italy). palaeogeography, palaeoclimatology, palaeoecology, 424, 183-195. scholz d., frisia s., borsato a., spötl c., fohlmeister j., mudelsee m., miorandi r., mangini a. (2012) holocene climate variability in north-eastern italy: potential influence of the nao and solar activity recorded by speleothem data climate of the past, 8, 1367-1383. seppä h., bjune a. e., telford r. j., birks h. j. b., veski s. (2009) last nine-thousand years of temperature variability in northern europe. climate of the past, 5, 523-535. 16 zanchetta g. et al. sevink j., van bergen m.j., van der plicht j., feiken h., anastasia c., huizinga a. (2011) robust date for the bronze age avellino eruption (sommavesuvius): 3945 ±10 cal bp (1995 ±10 cal bc). quaternary science review, 30, 1035-1046. staubwasser m., weiss h. (2006) holocene climate and cultural evolution in late prehistoric–early historic west asia. quaternary research, 66, 372387. thompson l.g., mosely-thompson e., davis m.e., henderson k.a., brecher h.h., zagorodonov v.s., mashiotta t.a., lin p., mikhalenko v.n., hardy d.r., beer, j. (2002) kilimanjaro ice core records: evidence of holocene climate change in tropical africa. science, 298, 589-593. tzedakis pc. (2007) seven ambiguities in the mediterranean palaeoenvironmental narrative. quaternary science reviews 26, 2042-2066. vollweiler n., scholz d., mühlinghaus c., mangini a., spötl c. (2006) a precisely dated climate record for the last 9 kyr from three high alpine stalagmites, spannagel cave, austria. geophysical research letters, 33, l20703, doi: 10.1029/2006 gl027662. walker m.j.c., berkelhammer m., bjorck s. et al. (2012) formal subdivision of the holocene series/ epoch: a discussion paper by a working group of intimate (integration of ice-core, marine and terrestrial records) and the subcommission on quaternary stratigraphy (international commission on stratigraphy). journal of quaternary science, 27, 649-659. wanner h., beer j., bütikofer j., crowley t.j., cubasch u., flückiger j., goosse h., grosjean m., joos f., kaplan j.o., küttel m., müller s.a., i. prentice i.c., solomina o., stocker t.f., tarasov p., wagner m., widmann m. (2008) midto late holocene climate change: an overview, quaternary science reviews, 27, 1791-1828 wanner h., solomina o., grosjean m., ritz s.p., jetel m. (2011) structure and origin of holocene cold events. quaternary science reviews, 30, 31093123. weiss h., bradley r.s. (2001) what drives societal collapse? science, 26, 291, 609-610. weiss h., courty m.-a., wetterstrom w., guichard f., senior l., meadow r., curnow a. (1993) the genesis and collapse of third millennium north mesopotamian civilization. science, 261, 9951004. welc f., marks l. (2014) climate change at the end of the old kingdom in egypt around 4200 bp: new geoarchaeological evidence. quaternary international, 324, 124-133. zanchetta g., di vito a., fallick a.e., sulpizio r. (2000) stable isotopes of pedogenic carbonate from somma-vesuvius area, southern italy, over the last 18 ka: palaeoclimatic implications. journal of quaternary science, 15, 813-824. zanchetta g., drysdale r.n., hellstrom j.c., fallick a.e., isola i., gagan, m., pareschi m.t. (2007) enhanced rainfall in the western mediterranean during deposition of sapropel s1: stalagmite evidence from corchia cave (central italy). quaternary science review, 26, 279-286. zanchetta g., giraudi c., sulpizio r., magny m., drysdale r.n., sadori l. (2012a) constraining the onset of the holocene “neoglacial” over the central italy using tephra layers. quaternary research, 78, 236-247. zanchetta g., van welden a., baneschi i., drysdale r.n., sadori l., roberts n., giardini m., beck c., pascucci v. (2012b) multiproxy record for the last 4500 years from lake shkodra (albania/ montenegro). journal of quaternary science, 27, 780-789. zanchetta g., sulpizio r., roberts n., cioni r., eastwood w.j., siani g., caron b., paterne m., santacroce r. (2011) tephrostratigraphy, chronology and climatic events of the mediterranean basin during the holocene: an overview. the holocene, 21, 33-52. zanchetta g., bini m., cremaschi m., magny m., sadori l. (2013) the transition from natural to anthropogenic-dominated environmental change in italy and the surrounding regions since the neolithic: an introduction. quaternary international, 303, 1-9. zanchetta g., bar-matthews m., drysdale r.n., lionello p., ayalon a., hellstrom j.c., isola, i., regattieri e. (2014) coeval dry events in the central and eastern mediterranean basin at 5.2 and 5.6 ka recorded in corchia (italy) and soreq cave (israel) speleothems. global and planetary science, 122, 130-139. zhornyak l.v., zanchetta g., drysdale r.n., hellstrom j.c., isola i., regattieri e., piccini l., baneschi i. (2011) stratigraphic evidence for a “pluvial phase” between ca. 8200-7100 ka from renella cave (central italy). quaternary science reviews, 30, 409-417. 17 ms. received: november 11, 2015 final text received: september 8, 2015 the so-called “4.2 event” in the central mediterranean ... 18 << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /none /binding /left /calgrayprofile (dot gain 20%) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /error /compatibilitylevel 1.4 /compressobjects /tags /compresspages true /convertimagestoindexed true /passthroughjpegimages true /createjobticket false /defaultrenderingintent /default /detectblends true /detectcurves 0.0000 /colorconversionstrategy /cmyk /dothumbnails false /embedallfonts true /embedopentype false /parseiccprofilesincomments true /embedjoboptions true /dscreportinglevel 0 /emitdscwarnings false 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/pdfxoutputintentprofileselector /documentcmyk /preserveediting true /untaggedcmykhandling /leaveuntagged /untaggedrgbhandling /usedocumentprofile /usedocumentbleed false >> ] >> setdistillerparams << /hwresolution [2400 2400] /pagesize [612.000 792.000] >> setpagedevice lithic productions during the first half of the middle pleistocene (mis 19-12) in the italian peninsula: an overview. brunella muttillo 1, giuseppe lembo 2, rosalia gallotti 3,4 1 sez. scienze preistoriche e antropologiche, dipartimento di studi umanistici, università degli studi di ferrara, italy. 2 associazione culturale archeoidea, campobasso, italy. 3 université paul valéry montpellier 3, cnrs, umr 5140 archéologie des sociétés méditerranéennes and labex archimède anr-11-labx-0032-01, montpellier, france. 4 université bordeaux 1 umr 5199 pacea-ppp, pessac cedex, france. corresponding author: b. muttillo <brunella.muttillo@unife.it> abstract: archaeological record of the italian peninsula during the first half of the middle pleistocene is characterised by a limited number of sites. in the last decade, new systematic research allowed to refine chronostratigraphies and to improve the contextual and technological information. here, we report an overview of the italian archaeological sites between mis 19 and mis 12 with the main aim to evaluate the current state of our knowledge on the technological behaviours from the earliest middle pleistocene sites where homo heidelbergensis appears to the emergence of hominins with neanderthal-like morphology. keywords: lower palaeolithic, italian peninsula, middle pleistocene, lithic technology, small flaking and large cutting tools. available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 34 (1), 2021, 33-54. 1. introduction archaeological evidence ascribed to the first half of the middle pleistocene has conspicuously improved over the last decades in western europe. however, notwithstanding increased research and more discoveries, the available information is highly fragmented and insufficient at different levels. from a technological perspective, the early middle pleistocene in western europe is marked by the emergence of the acheulean technology (e.g., barsky & de lumley, 2010; de lumley et al., 1984; desprièe et al., 2010; moncel et al., 2019, 2020; piperno, 1999; scott & gibert, 2009), that some authors linked to the first appearance datum of homo heidelbergensis (e.g., moncel et al., 2019; stringer, 2012). nevertheless, assemblages lacking large cutting tools (lcts1) and multi-layered sites with an alternation of lithic series with or with no or very rare lcts are known in western europe and they do not pattern into a two-phase periodization (abruzzese et al., 2016; ashton et al., 1992; aureli et al., 2015, 2016; biddittu, 1971, 1972; carbonell et al., 1999; cauche et al., 2004; crovetto, 1993; gallotti & peretto, 2015; moncel et al., 2020; nicoud et al., 2015, 2017, 2020; parés & pérezgonzalez, 1999; parfitt et al., 2005; peretto, 1994; piperno, 1999; preece & parfitt, 2012; rocca et al., 2016, 2019, 2020; rose, 1992; santagata, 2016; segre & biddittu, 2009; tuffreau & lamotte, 2010). in the italian peninsula, there are no archaeological sites between marine isotope stage (mis) 19 and mis 17 and sites recorded in an indisputable stratigraphic context between mis 17 and mis 12 are few and fragmented both temporally and spatially. however, different interpretations have been proposed to draw the tempos and modes of the settlement in this time-span and the related technical behaviours (e.g., grifoni & tozzi, 2006; orain et al., 2012). here, we present an update of the data available in scientific literature on those sites systematically investigated and with a constrained chronological framework (fig. 1). our main aim is to draw up an overview of the https://doi.org/10.26382/amq.2021.05 1 lcts are intended here as shaped or retouched tools with a length or width > 10 cm. they include massive scrapers, handaxes, picks, bifaces, and cleavers. bifaces are intended in a technological perspective as lcts whose morphology «résulte de l’aménagement simultané de deux convexités, de manière à ce que l’une soit à l’image de l’autre en fonction d’un plan d’équilibre bifacial […] de l’intersection de ces deux convexités naît une silhouette «lissée» par retouche, qui se distribue par rapport à un plan d’équilibre bilatéral» (roche & texier, 1991: 102). cleavers (sensu tixier, 1956) are intended here as lcts obtained either by flaking only, or by flaking followed by shaping. the cutting edge must be left unretouched, i.e. it is the outcome of the flaking of the blank. bifacial pieces with a bit achieved by shaping or by lateral tranchet blow technique are not cleavers but beveled handaxes (inizan et al., 1999). 34 muttillo b. et al. current state of knowledge on site context, chronostratigraphies, faunal composition, and, in particular, on lithic analyses in the italian peninsula between the early middle pleistocene sites (mis 17/15; piperno, 1999; moncel et al., 2020) where homo heidelbergensis appears and the emergence of hominins with neanderthallike morphology, approximately dated to mis 12 (zanolli et al., 2018). 2. an overview of the middle pleistocene sites in italy during mis 19 mis 12 2.1. notarchirico (basilicata, southern italy) the archaeological site of notarchirico is located in the venosa basin (basilicata), which covers more than 60 km and is known for its prehistoric heritage since the 19th century (bulgarelli et al., 1999). the fluviallacustrine middle pleistocene succession of this basin represents the sedimentary filling of a palaeovalley located between the vulture volcano and the murge massif (apulian foreland) (caruso et al., 2012). the basin fill is composed of three litho-stratigraphic units (lefèvre et al.,1994,1999, 2001, 2002; raynal et al., 1998) which can be correlated with the sequence of eruptive units produced by monte vulture (giannandrea et al., 2006; la volpe & principe, 1989, 1994). the oldest unit, the fonte del comune formation, is contemporary with the initial phases of volcanic activity. it is surmounted by two embedded volcano-sedimentary units, the piano regio and tufarelle formations, contemporary with the major early middle pleistocene phases of the volcanic activity of monte vulture. the site of notarchirico was discovered in 1979 and excavated from 1980 to 1995 by m. piperno (piperno, 1999). the stratigraphic sequence is mainly composed of volcanoclastic sediments deposited and reworked in an alluvial environment belonging to the piano regio formation (lefèvre et al., 2010). during piperno’s excavations in the 1980s, several archaeosurfaces (, a, a1, b, c, d, e, e1, f, g, g1, h, and i) were discovered in a seven-metre thick fluvial-derived sedimentary sequence rich in volcanic materials from the neighbouring monte vulture stratovolcano (lefèvre et al., 2010). above layer f several direct tephra fallouts are located (raynal et al., 1999; vernet et al., 1999), which form the notarchirico tephra complex (levels 2-1 to 2-5), dated to 640±40 ka by thermoluminescence on quartz (pilleyre, 1991; pilleyre et al., 1999). at the top of the site, levels 1-6 are composed of reworked volcanic sands, which geochemical composition highlighted their similarity to a major tephrostratigraphic marker of the tufarelle formation (pereira et al., 2015; raynal et al., 1998). new radio-isotopic data assessed that the whole notarchirico sequence was deposited in probably <70 ka, between 670±4 ka (14 ka) and 614±4 ka (12 ka) (pereira et al., 2015), i.e., mainly during the glacial mis 16, confirming the previous lithostratigraphic analyses (lefèvre et al., 1999). since 2016, new fieldwork at notarchirico, directed by m.-h. moncel, opened a 30-m-long trench on the side of notarchirico hill, at the base of the previously studied sequence. four archaeological layers were identified: three of them correspond to layers f, g, and i of the piperno’s excavations; layer j was discovered at the very base of the sequence (moncel et al., 2020). 40ar/39ar constrain these layers between 668±6 ka and 695±6 ka (moncel et al., 2020). the faunal assemblage belongs to the ‘ponte galeria’ faunal unit. the main species found are elephas (=palaeoloxodon) antiquus, dama clactoniana, bos primigenius and bison schoetensacki. the lower layers (e/e1, f, and g) yielded poorly preserved faunal fragments. fauna from the higher layers (a, sub-a, a/a1, b and d) is in better condition, including new species such as cervus elaphus and megaloceros solilhacus. faunal fig. 1 middle pleistocene italian sites analysed, in relation to the chronology (a) and to the geographical location (b). 1. notarchirico (basilicata); 2. cimitero di atella (basilicata); 3. isernia la pineta (molise); 4. valle giumentina (abruzzo); 5. loreto (basilicata); 6. ficoncella (lazio); 7. visogliano (friuli venezia giulia). see main text for references on archaeological site chronology. chronological chart modified from cohen & gibbard (2019) (graphic processing: g. lembo). 35 lithic productions of the middle pleistocene in the italian peninsula list of the moncel’s excavation is almost similar to that of the youngest layers  and a of notarchirico (cassoli et al., 1999; moncel et al., 2020). two species are newly reported: hippopotamus antiquus in layers g and i1, and macaca sylvanus ssp. in layer g (moncel et al., 2020). several species of micromammals were identified, principally in horizon e1 (pliomys episcopalis, chionomys nivalis, microtus sp. and arvicola cantiana), indicating a cold climate typical of a middle pleistocene glacial period in the italian peninsula (sala, 1999). an open and cold environment is confirmed by palynological analysis (cattani, 1996). in scientific literature, notarchirico is recurrently presented as a site «characterised by repeated periods of occupation, for the most part related to butchery activities, as illustrated by the elephant butchery area […] (piperno & tagliacozzo, 2001)» (pereira et al., 2015: 641). nevertheless, an archaeozoological analysis has been performed only on the faunal remains from layer , showing that faunal remain accumulation evidences a multiple origin (tagliacozzo et al., 1999), and from layers f, g, i1, i2, and j where no clear cut marks or anthropic bone breakages were identified (moncel et al., 2020). the association between artefacts and bones in the elephant butchery area (layers a-a1-b) has been taken as granted than proved, even if lefèvre et al. (1994: 109) asses that: «[…] ces observations conduisent à distinguer la mise en place des sédiments de celle du crâne (pas d’apport en masse), mais ne permettent pas d’aller plus loin en ce qui concerne le mode de dépôt de ce dernier (flotté puis échoué, ou mort sur place), à plus forte raison donc les causes de sa mort […] reste posée la question de la réalité de l’association éléphant/restes lithiques. si association il y a, tous les objets présents dans la lentille de gravier lui appartiennent-ils? sinon, comment les distinguer?». thus, the association between elephant remains and lithic artefacts is still an open issue. in the upper part of the sequence (layer ), a fragment of a human femur, attributed to homo heidelbergensis, was discovered in 1985 (mallegni et al., 1991; pereira et al., 2015). the lithic artifacts recorded during excavations at notarchirico are about 3600, approximately 2500 from piperno’s excavation and 1152 from moncel’s excavation (tab. 1). part of the artefacts belonging to piperno’s excavation were left on the archaeological surfaces for museum purposes (piperno, 1999). notarchirico is well known for the alternance of layers with “bifaces” (a, a1, b, d, f, g/g1, i2) and layers lacking “bifaces” (, c, e, e1, h, i, j). two type of raw materials of local origin, abundantly available in the paleochannels, have been used: silicite2 pebbles, cobbles, nodules and tablets, as well as limestone cobbles and rare boulders. flakes and cores are mainly on silicite and the heavy-duty component (including lcts) mainly on limestone cobbles (piperno, 1999; moncel et al., 2020). the lithic assemblages of the different archaeological layers have not been entirely studied and according to a homogeneous approach (tab. 1). if the lcts have recently been analysed in a technological perspective (moncel et al., 2019; santagata, 2012, 2016), and some of them according to a techno-functional approach (nicoud, 2011), small flaking is known for layers b, e/e1 (santagata, 2016), f, g, i1, i2, j (moncel et al., 2020). only the artefact assemblage from layer  have been entirely analysed following a typo-metrical approach (piperno, 1999). in the basal part of the sequence (layers f, g, i1, i2, j) cores are unifacial, unifacial centripetal-cordal, and multifacial. they are mainly on silicite, very few on limestone. flaking follows the natural shape of the silicite nodules (semi-rotation of the cores to exploit more than one flaking surface), rectification of the striking platform is limited, and the technique is the freehand percussion. according to the flaking methods, flake butts are cortical or plain, rarely dihedral or facetted. flaking products as well as raw nodules are retouched (5 to 20%) on one or several edges by marginal, abrupt or denticulate retouch. convergent tools are rare. the heavy-duty component is composed by unifacial shaped cobbles (chopper-cores), some of which are pointed. several lcts on limestone cobbles or flakes and large silicite nodules were found (tab. 1). the shaping involves a large part of the periphery and surface of the artefacts managing the bifacial volume and the equilibrium of the two faces and producing symmetrical or plano-convex cross-sections. sometimes retouch regularizes the edges. in layer b, small flaking on silicite and limestone includes chopper-cores, multifacial multidirectional cores and bipolar-on-anvil cores. shaping produces: 1) choppers on limestone cobbles, some of them with two convergent edges creating a point; 2) handaxes on limestone and silicite, usually shaped on cobbles, showing a high morpho-technical variation; 3) cleavers-like on cobbles (santagata, 2016). the latter are not cleavers sensu stricto (tixier, 1956), because they do not show an unretouched transversal cutting edge belonging to flaking. in layers e/e1, silicite cores with limited cortex, mainly unifacial unidirectional with a cortical striking platform, are smaller than those in layer b. their size seems more related to the very small size of the blank than to an overexploitation. cores with bifacial and multifacial irregular exploitation are also present and usually overexploited. there are no lcts in these layers and shaping is limited to rare bifacial choppers. some flakes were retouched into denticulated scrapers (santagata, 2016). only data on lcts are available for the other layers. moncel et al. (2019) published the analysis of the lcts identified in the notarchirico sequence and assessed that «hominins had the capacity to manage bifa 2 in scientific literature, the terms flint and chert are controversial depending on whether they are used by geologists, archaeologists, petrographers or sedimentologists. following delvigne et al. (2020), here we use the general term silicite for sedimentary silicified rocks of chemical, biochemical or diagenetic origin of various types including flint, chert, silcrete, and jasperoid. 36 muttillo b. et al. 37 lithic productions of the middle pleistocene in the italian peninsula t a b . 1 m a in c h a ra c te ri s ti c s o f th e m id d le p le is to c e n e i ta lia n s it e s b e tw e e n m is 1 9 a n d m is 1 2 . n . a .= n o t a v a ila b le d a ta . *u n p u b lis h e d d a ta ( d a ta u p d a te d t o t h e 2 0 1 8 e x c a v a ti o n ). cial volumes by alternate or face-by-face shaping during glacial stage mis 16 (676-621 ka), when raw materials were of appropriate quality. several series of removals contributed to rectify the edges and the tip. the tools present sinuous edges despite the sporadic use of final retouch, on account of the use of limestone pebbles instead of flint nodules. we observed a mixture of bifaces sensu stricto and not finished bifacial tools depending on the extension of shaping» (moncel et al., 2019: 20). however, there is no consensus on this interpretation. results of the lcts analysis performed by e. nicoud (2011) adopting a techno-functional approach show that «d’un point de vue techno-morphologique et en comparaison avec le reste de l’outillage, aucun objet relevant d’une conception bifaciale singulière n’a été mis en évidence» and that lithic productions of macrotools are characterised by «[…] une chaîne opératoire courte de confection d’outil(s) sur galets […]» (nicoud, 2011: 324). 2.2. cimitero di atella (basilicata, southern italy) cimitero di atella is an open-air site (ca. 480 m asl) located in the village of atella (potenza, basilicata), about 10 km to the south of the monte vulture and 30 km to the west of loreto and notarchirico. it has been investigated since 1990 under the direction of prof. borzatti von löwenstern università di firenze (borzatti von löwenstern et al., 1990, 1997, 1998) and, since 2014, under the direction of r. rocca in a new project led by the école française de rome (abruzzese et al., 2016; rocca & aureli, 2019; rocca et al., 2020). the site was located on the shores of a lake developed during the middle pleistocene (borzatti von löwenstern et al., 1998). according to geological and geomorphological studies on the atella basin area and on the basis of the presence of handaxes, the site was attributed to the early acheulean (borzatti von löwenstern et al., 1997). two archaeological layers (f and l) were identified within a stratigraphy composed of volcanoclastic and lacustrine sediments. the stratigraphic sequence presents, at the base, several sterile silt layers (a-e), lake deposits composed of limno-volcanic sediment. these are covered by the acheulean layer (f) interpreted as landslides of the lake shores. at the top, there are a sandy deposit of lacustrine origin (i) and a volcanoclastic layer containing a small lithic assemblage (l) (borzatti von löwenstern et al., 1997; abruzzese et al., 2016). these archaeological layers were heavily affected by post-depositional processes (rocca & aureli, 2019; rocca et al., 2020). in 2018 and 2019 several test pits in a new area contiguous to the borzatti’s excavation revealed the existence of a less disturbed layer, at the top of layer f. this new layer, still under study, yielded lithic and faunal remains in a good state of preservation (rocca & aureli, 2019; rocca et al., 2020). the chronology of the site was constrained thanks to the correlation with vulture eruptive events (di muro, 1999). the dating of the acheulean layer f should be comprised between 660-650 ka (uvs masseria boccaglie; layers a-e) and 480 ka (uvs masseria granata; layer l). however, this interpretation needs to be confirmed (abruzzese et al., 2016; rocca et al., 2016). the faunal remains, generally very altered, mainly consist of palaeoloxodon antiquus (borzatti von löwenstern et al., 1997), bos primigenius and cervids (dama, cervus and capreolus) (zucchelli, 2000; 2002). the revision of the historical collections and the preliminary data from the new excavations confirm the presence of palaeoloxodon, fallow deer, and bovid. however, the distinction between bos and bison needs to be demonstrated (rocca & aureli, 2019; rocca et al., 2020). lithic industry (tab. 1) was mainly knapped on silicite pebbles/cobbles collected near the site, and only to a lesser extent on quartzite and porous radiolarite (with a higher degree of alteration) (borzatti von löwenstern et al., 1992; sozzi et al., 2004). previous typometrical analysis recognised a poorly structured lithic industry, composed by small flakes, cores, small tools (difficult to classify), knapping waste, and handaxes. the handaxes (n=50) were manufactured exclusively on porous radiolarite. the small size of the industry was linked to the use of bipolar percussion on anvil (borzatti von löwenstern et al., 1997). the lithic industry of layer f was recently revised with a technological and techno-functional approach. on 7887 pieces, only 638 (8% of the entire set) were analysed due to taphonomical reasons, excluding the nonanthropic items (with a very poor state of preservation) (abruzzese et al., 2016; rocca et al., 2016). the selected sample is composed by few cores (2%) exploited through a ssda method (forestier, 1993), flakes (42%), retouched flakes (25%, the majority are notches), small tools (30%), and few large tools (1%). the presumed handaxes are now interpreted as large tools unifacially shaped (bifacially shaped in only one case) obtained on large flakes of radiolarite (abruzzese et al., 2016). on the other hand, the small tools represent an important part of the assemblage: shaped on natural blanks or flakes, are generally thick, with a flat surface opposed to a convex surface and with different cutting edges (front, convergence, denticulate) (abruzzese et al., 2016; rocca et al., 2016). the whole lithic industry is very altered, mechanically and chemically (mainly pseudo-retouch, smoothness and, to a lesser extent, patina) (abruzzese et al., 2016; rocca et al., 2016). preliminary data from the new recently identified layer confirm the technological revision performed so far: the lithic assemblage is mainly composed by small flakes related to the confection/retouch of few small tools in silicite, lacking lcts (rocca & aureli, 2019; rocca et al., 2020). 2.3. isernia la pineta (molise, central southern italy) isernia la pineta is an open-air site (of about 350 square meters, over two different sectors) located a few kilometers from the town of isernia (molise). the systematic excavations, under the direction of prof. carlo peretto università di ferrara, began in 1979 and are still in progress (e.g., lembo, 2015; peretto, 2013; peretto et al., 2015). at 457 m asl, the site lies inside the main filling of the upper volturno river basin (brancaccio et al., 1997; coltorti & cremaschi, 1983; van otterloo & sevink, 1983). 38 muttillo b. et al. than at present and the environment was characterized by an arboreal steppe, with the presence of pounds of water and deciduous forests in the surrounding area (accorsi et al., 1996). the lithic industry (studied so far ca. 50% of the lithic assemblages, tab. 1) is focused on small-medium flake production, lacking lcts. it is made with local raw materials, mainly different types of silicite tablets and only to a lesser extent limestone cobbles, collected in secondary position in the immediate vicinity of the site. until the first decade of the 2000s, the lithic industry of isernia la pineta was considered unstructured and opportunistic, lacking tools deliberately retouched. based on the ‘80s -‘90s and early 2000s analysis on the lithic assemblages from a small portion of 3a and 3c, it was suggested that the tools were the accidental result of intense bipolar exploitation of silicite tablets (crovetto, 1994; longo et al., 1997; minelli et al., 2004; peretto, 1994). on the contrary, recent techno-economic studies of 3c (gallotti & peretto, 2015) and 3coll layers (peretto et al., 2015; rivera peréz, 2016) considerably reduce the use of bipolar technique on anvil (not documented in 3c layer; gallotti & peretto, 2015) and demonstrate that retouch was a deliberate and specific phase and not the occasional result of intense bipolar exploitation. in general, the silicite lithic industry of isernia la pineta is characterized by relatively long sequences of reduction which show a high degree of planning. the mental templates and the technical criteria employed in small flaking are not opportunistic and unstructured as previously inferred, witnessed by: the use of different methods (unifacial unidirectional, multifacial unidirectional, and discoid; fig. 2); the mastery of the discoid method, regardless of the size and shape of the blank; the selection of specific forms for a specific production; the systematic use of retouch in order to produce small tools (denticulates, notches, and sidescrapers) (gallotti & peretto, 2015). the local limestone cobbles were exploited mainly for flaking and rarely for shaping (arnaud et al., 2017). small-medium flakes were obtained by direct hardhammer percussion through simple and short reduction sequences, mostly using a unifacial unidirectional method (gallotti & peretto, 2015) or by the exploitation of one to three not prepared striking platforms (rufo et al., 2009). few choppers were recovered in the 3a and 3coll layers (rufo et al., 2009); rare retouched flakes were recovered in the 3coll layer (rivera peréz, 2016). 2.4. valle giumentina (abruzzo, central italy) valle giumentina is a pleistocene open-air site, located in a small intermountain basin (at 740 m a.s.l), on the northwestern side of the majella mountain massif, in abruzzo (central italy). several archaeological layers were identified in a ca. 25 m thick sedimentary sequence, made of alluvial and lacustrine/marshy deposits and paleosols. the site was investigated, in the 1950s and 1960s, by prof. radmilli università di pisa, over a surface of approximately 40 m2 (radmilli, 1965). attribution of valle giumentina deposits to the rissian and würmian glacial stades was based on sedimentary data and not on the typology of the lithic industries the stratigraphic sequence is made of fluvial, lacustrine and volcanic sediments. from bottom to top, 5 sedimentary units were recognized (coltorti et al., 2005; peretto et al., 2015): unit 5, lacustrine clays; unit 4, travertines; unit 3, palustrine deposits with sands and thin layers of gravels, subdivided in several sub-units (3f, 3e, 3d); unit 2, gravels with thin layers of sands; unit 1, a colluvium sequence, including a pyroclastic fall dated at 499±13 ka (40ar/39ar, 2; coltorti et al., 2005). four archaeosurfaces (3c, 3a, 3s10 sect. i, 3a sect. ii) have been identified and excavated. 3c is the oldest occupation layer, contemporaneous with unit 4: archaeological and paleontological remains lie at the top of calcareous tufa. 3a is characterised by a high concentration of faunal remains (mostly of large bones) and of silicite and limestone artefacts. above 3a, lies 3coll, a pyroclastic layer (debris-flow) rich in archaeological materials (marrocchino & vaccaro, 2006). previously dated at 610±10 ka (40ar/39ar; coltorti et al., 2005), 3coll was recently dated at 586±2 ka (40ar/39ar; peretto et al. 2015). the most recent chronological analysis constrains the age of the archaeosurfaces to the end of mis 15, more precisely between 583 ka (unit 4 deposition age) and ca. 561 ka, at the beginning of the full glacial mis 14 (peretto et al., 2015). an isolated human deciduous incisor was discovered in 2014 within the archaeological layer 3coll, related to an undetermined homo, i.e. homo sp. (peretto et al., 2015). numerous macro-mammals have been identified, characteristic of the middle galerian, mainly consisting of the following taxa: elephas (palaeoloxodon) antiquus, hippopotamus cf. antiquus, stephanorhinus hundsheimensis, bison schoetensacki, praemegaceros solilhacus, cervus elaphus cf. acoronatus, dama cf. roberti, capreolus sp., sus scrofa, hemitragus cf. bonali. among the carnivores, the most abundant remains belong to ursus deningeri. only one tooth of panthera leo fossilis and a mandible of panthera pardus were identified (ballatore & breda, 2013; breda et al., 2015; channarayapatna et al., 2018; peretto et al., 2015; sala, 1996; thun hohenstein et al., 2004, 2005, 2009). zooarchaeological analysis (anconetani & peretto, 1996; malerba et al., 2000; peretto et al., 2004; pineda et al., 2020; thun hohenstein et al., 2005, 2009) suggests a relative homogeneity in the taxonomic representation models along the sequence. evidence of carcass processing is documented through anthropic breakage (mainly on skulls, jaws and long bones) and in the form of cut marks on bone surfaces. the predominance of bison and, to a lesser extent, rhinoceros and bears, is the result of anthropic selection. the predominance of cranial elements and forelimbs and, among the remains of bison, the predominance of adult and sub-adult individuals is explained by the selective transport of the carcasses (thun hohenstein et al., 2009). among the small mammals, the best represented species are arvicola mosbachensis, sorex aff. runtonensis, pliomys episcopalis and microtus (terricola) arvalidens (sala, 1996). all these data, combined with pollen studies, suggest that the climate was probably more arid and cooler 39 lithic productions of the middle pleistocene in the italian peninsula 40 muttillo b. et al. fig. 2 isernia la pineta, layer 3c. silicite artefacts. 1-6: unifacial unidirectional cores; 7, 8: retouched flakes with unidirectional negative scars on the dorsal face; 9, 13, 15: discoid cores; 10-12, 14, 16: retouched flakes belonging to a discoid flaking. drawings: m. pennacchioni. 41 lithic productions of the middle pleistocene in the italian peninsula fig. 3 1-8: silicite small tools from loreto layer a (modified after crovetto, 1993); 9-18: silicite discoid core (9), silicite small tools (10-15), and limestone flakes (16-18) from visogliano, rockshelter a, levels 40-45 (modified from abbazzi et al., 2000); 19-24: silicite cores (19, 20) and small tools (21-24) from valle giumentina, layer 33 (modified after nicoud et al., 2015). (demangeot & radmilli, 1966). in particular, the archaeological layers were described, from the bottom to the top, as: clactonian (named “evolved clactonian of valle giumentina facies”) (layers 20, 24, 30, 33, 40, 42), according to the presence of tools on thick flakes; acheulean (layer 37), with only five handaxes and handaxe flakes; levalloisian (layer 45, 46), to design a mixed industry (probably not in situ) including levallois products (radmilli, 1982; radmilli, 1965). the presence of the acheulean layer among the layers assigned to the clactonian, confirmed the hypothesis of scholars supporting the coexistence and contemporaneity of these two industries (radmilli, 1982). the rare faunal remains belong to ursus sp. and cervus elaphus (radmilli, 1965). new systematic archaeological excavations and interdisciplinary research started in 2012 and still in progress under the direction of e. nicoud, allowed to acquire new chronostratigraphical, paleoenvironmental, and archaeological data (limondin-lozouet et al., 2017; nicoud et al., 2015, 2016, 2017, 2020; villa et al., 2016a). the new studies have reduced the marshy contribution, recording glaciofluvial-lacustrine sedimentation during glacial periods and pedogenesis and/or alluvial sedimentation during interglacials (villa et al., 2016b). five main litho-pedostratigraphic units, named sedimentary units (su), were recognised and correlated with the radmilli’s excavation. from bottom to top (villa et al., 2016a, b): su5, a thick fluvial gravel deposit, which overlies the miocene limestone bedrock; su4, lacustrine and marshy calcareous sediments, indicating the formation of a shallow lake; su3, clayey organic deposits, attesting the evolution from lacustrine to marshy environments, containing archaeological layer 20; su2, calcareous silt and clay, containing 24, 30, and 33 archaeological layers; su1, sandy/silty sediments, interbedded with four palaeosols, containing 37, 40, 42, 45, and 46 archaeological layers. 40ar/39ar dating, and other palaeoenvironmental and tephrochronological data, assigned the whole succession to the mis 15-mis 12 interval. more precisely, the clactonian layers 24, 30, and 40 (ln-24, lan2-30, and labm-40, according to the new excavations) are dated at 556±6 ka, 531±5 ka, and 456±2 ka, respectively (villa et al., 2016a). therefore, according to the recent dating, the acheulean layer slm-37 should be dated between ~ 530 and 450 ka. with the recovery of the excavations, a technoeconomic approach in the study of lithic industries was introduced and the use of ‘clactonian’ term was dismissed (nicoud et al., 2015). only a small sample of the lithic assemblage excavated in the 1950s has been reviewed (tab. 1; nicoud et al., 2015). therefore, data are partial and must be considered with caution. the lithic industry was made from blocks of different types of silicite, locally available and recovered in secondary position. the state of preservation is generally good. in 20, 30, 33, 40, 42 layers exclusively short flaking sequences are attested. cores are exploited through ssda method (forestier, 1993), producing flakes of a very varied morphology. retouched flakes (mainly sidescrapers and denticulates) are thick, cortical or semicortical, with the retouched cutting edge opposite to a back (nicoud et al., 2015; fig. 3: 19-24). only in the acheulean layer (37) a shaping production coexists with one or more flaking sequences. in this layer, were recovered 11 flakes, three sidescrapers, six notches, two atypical points, five handaxes and 475 debris, of which the majority are thin flakes linked to the bifacial shaping (radmilli, 1965) but also to flaking (nicoud et al., 2015). as the research is still in progress, only preliminary data from excavation’s reports are available for the lithic assemblages from the recently excavated layers labm40, slm-37, and abf-33 (nicoud et al., 2017, 2020) (tab. 1). the lithic assemblages of silicite are composed of cores, small flakes and small tools. a handaxe was recovered in labm-40 (nicoud et al., 2017). complete and detailed data are available only for the recently excavated layer alb-42 (nicoud et al., 2016). a technological approach combined with a techno-functional analysis (böeda, 2001) was used to analyse lithics (n=223) recovered in this layer. the alb-42, investigated over a surface of ca. 48 m2, is the last archaeological layer before the occurrence of levallois and it covers the 456±2 ka dated layer (labm; villa et al., 2016a). the scarce faunal remains (n=32) belong to cervus elaphus and microtus arvalis. striae and chopping evidence were detected on a thoracic vertebral spine (nicoud et al., 2016). the lithic assemblage is mostly composed of flakes (n=183), retouched flakes (n=28), and few cores (n=3), suggesting a fragmentation of the lithic production. however, some refits indicate an in situ production and suggest limited post-depositional disturbances. there are no lcts in this layer. several methods were used, including: a “tranches de saucisson” method (turq, 1989), an alternating surfaces method resembling the ssda method (forestier, 1993), and an orthogonal flaking (sensu ashton et al., 1994). these methods were ascribed to a single concept of core volumetric structure, in which the block selection represents a crucial phase. the accurate selection of surfaces with suitable volumetric characteristics, allowed to exploit the core by a short series of removals without any preparation of the striking platform or the flaking surface. backed flakes are frequent. the scaled retouch creates various types of cutting-edges on different kinds of blanks. tools belong to the typological categories of scrapers (lateral or distal), back knives, notches, and denticulates (nicoud et al., 2016). 2.5. loreto (basilicata, southern italy) since the end of the 19th century, the site of loreto in the venosa basin, located on a hill few kilometers from notarchirico, has been investigated. a.c. blanc conducted the first excavations between 1956 and 1961, directed by g. chiappella. between 1974 and 1981, the musée d’anthropologie préhistorique de monaco carried out new research, directed by l. barral and s. simone with the collaboration of g. chiappella. the archaeological layer a was excavated on a surface of ~20 m2 and yielded faunal remains and lithic artefacts (crovetto, 1993). the faunal list of layer a includes palaeoloxodon cf. antiquus, dicerorhinus etruscus, equus stenonis, 42 muttillo b. et al. equus cf. süssenbornensis, equus hydruntinus, equus altidens, hippopotamus cf. amphibius, bison schoetensacki, megaceros solilhacus, dama nesti, dama dama, capreolus cf. affinis, capreolus cf. süssenbornensis, ursus deningeri, canis cf. arnensis, canis etruscus, hyaenidae sp., felis pardus, homotherium sp., and oryctolagus cuniculus (alberdi et al., 1988; bonifay, 1977). several authors considered loreto stratigraphic sequence and faunal composition older than notarchirico site on the basis of (bio)stratigraphic correlations (e.g., belli et al., 1991; caloi & palombo, 1980). according to bonifay (1977) and caloi & palombo (1979a, 1979b, 1980), this fauna belongs to the günzmindel glacial periods or to the beginning of the mindel; other authors suggested they are of cromerian stage (angelelli et al.,1978); alberdi et al. (1988), based on the study of equidae remains, assessing that fauna belongs to the beginning of the middle pleistocene. new geological research based on a lithostratigraphic approach in the venosa basin allowed a reappraisal of the notarchirico and loreto stratigraphic correlations (lefèvre et al., 1993, 1994, 1999, 2001, 2002; raynal et al., 1998). the succession of loreto deposits from the foot of the hill to the top is as follows (lefèvre et al., 2010): 1) banks of conglomerates with a reverse magnetic polarity (gagnepain, 1996); 2) highly heterometric conglomerates, formed by some hyper-concentrated lahar (sensu lato) flows, corresponding to member a of the tufarelle formation; 3) a succession of reworked tephras and horizontal limestone banks, indicating sedimentary lacustrine environments; two grey scoria fallouts are inserted into this unit which characterize the member b of the tufarelle formation; 4) ascending further uphill, the series gradually becomes less epiclastic in a sensu lato lacustrine environment where archaeological layer a lies on an encrusted emersion surface. these surfaces can be correlated to the base of member c. this member has been dated to 484±8 ka (brocchini et al., 1994), 494±5 ka, and 530±22 ka (villa & buettner, 2009) based on stratigraphic correlations; 5) the upper facies of the basin fill which contains deposits related to the upper acheulean are difficult to characterise due to the absence of outcrops. accordingly, layer a at loreto site is younger than the notarchirico sequence corresponding to the member c of the tufarelle formation and is approximately dated to 500ka on intra-basin stratigraphic correlations (lefèvre et al., 2010). pereira (2017) confirms that this stratigraphic correlation is the most plausible, but the new 40ar / 39ar results unfortunately do not give a precise chronological constraint for this site. layer a yielded 528 lithic objects (tab. 1), analysed by c. crovetto (1993). crovetto’s study represents a pioneering technological analysis of a lower palaeolithic complex in italy. furthermore, it is even more exemplary because it concerns not only the entire artefact assemblage, but also the natural materials recorded during the excavation. artefacts were flaked on silicite cobbles, pebbles, and tablets of small dimensions and larger limestone cobbles. silicite assemblage (n=307) is composed by cores and flakes, most of them retouched (46% of the flakes). silicite cores are unifacial unidirectional or bipolar and multifacial multidirectional irregular or orthogonal, some of them with a preferential flaked surface. striking platforms are usually cortical or rectified by onetwo removals. the flaking method in not related to a specific blank. knappers indifferently used rounded cobbles, angular cobbles, and tablets. reduction sequences are short and cores show remaining cortical surfaces. negative scars on the dorsal face of the flakes are in agreement with the flaking methods identified on the cores, but they are also centripetal. retouched flakes are side-scrapers with denticulated and stepped retouch, denticulates, notches, end-scrapers, becks, and small points (fig. 3: 1-8). limestones assemblage is mainly composed by cobbles with few removals (simple cores sensu delagnes & roche 2005), chopper-cores with unifacial or bifacial removals, few cores and flakes, rarely retouched. limestone cores are multifacial with an orthogonal exploitation. knappers used the flat surface of angular/rounded cobbles as first striking platform and conducted an orthogonal multifacial flaking rotating the core and respecting the original orthogonal angles among the faces. accordingly, this method shows a high capacity of adaptation to the natural blank. s. simone (1980) also classified an “abevillian biface”, not studied by c. crovetto because at the time it was on display in the exhibition “i primi abitanti d’europa” (crovetto, 1993). 2.6. ficoncella (lazio, central italy) the site of ficoncella is located near tarquinia, northern latium (central italy). at ca. 70 m a.s.l., the site is part of the plio-pleistocene tarquinia basin, which extends for almost 40 km along the latium tyrrhenian margin. discovered during the 1990s, it was investigated since 2010 until 2015 under the direction of d. aureli (aureli et al., 2012, 2015, 2016). a small excavation area yielded, in a single archaeological layer (named fic 1), a small lithic industry associated with parts of an elephant carcass, remains of ungulates, and a hyaena coprolite. faunal and lithic remains may have been buried shortly after emplacement by alluvial/floodplain deposits (aureli et al., 2015, 2016; boschin et al., 2018). three main depositional units were identified within a stratigraphic sequence containing floodplain deposits. the lowest unit (fic 1) is made up of sandy to silty sediments, containing several tephra layers and the archaeological horizon. the features of fic 1 are consistent with the ‘fall a pumice unit’, from a plinian eruption in the sabatini volcanic district, dated at ca. 499 ka. a 2-3 m thick ignimbritic deposit (fic 2), dated at 441± 8 ka (40ar/39ar), cover this unit. this dating is consistent with the attribution to the ‘tufo rosso a scorie nere’ from sabatini volcanic complex. fic 3 is the uppermost unit, consisting of silty deposits (aureli et al., 2015, 2016). therefore, the human occupation occurred during the mis 13. more precisely, the archaeological layer is comprised between a tephra layer attributed to a sabatini 43 lithic productions of the middle pleistocene in the italian peninsula eruption (dated to ~499 ka) and an ignimbrite unit (fic 2), dated to 441±8 ka. the faunal assemblage (n=364) is mainly composed by remains of a single elephant carcass (palaeoloxodon antiquus) and largely fragmented bones of cervids and bovids (equus sp., dama sp., and capreolus sp.). an impact notch on bone and some cone and conchoid flakes from intentionally fractured skeletal elements were found. gnawing marks were identified on some elephant bones (boschin et al., 2018). the lithic material was analysed through a technological approach combined with a techno-functional approach and use wear analysis (tab. 1; aureli et al., 2015, 2016; rocca et al., 2016). despite the incompleteness and the fragmentation of the reduction sequence, the presence of refittings (n=10) and the state of preservation indicate that knapping took place in situ. it is a small tool industry, in which lcts are absent. the set (n=409) is composed by a large number of small debris (n=296), initial and production flakes, retouched flakes and cores (aureli et al., 2015). two major reduction sequences were identified: the first one, represented by few pieces, concerns the exploitation of large cobbles of local limestone, in order to obtain medium/large flakes with robust and long cutting­ edges; the second sequence, that represents the majority, is performed on marine/fluvial pebbles of silicite (and occasional on quartz) whose provenance is not known, in order to obtain ‘small­tools’, with several cutting­edges (aureli et al., 2015, 2016). three main groups of tools were identified, i.e. the spina (a small pointed part of the tool with a trihedral section, and a central ridge), the mini-rostrum (small robust bevel with an important angle with a slightly denticulate delineation) and the rectilinear edges (aureli et al., 2016). although the blanks are issued from different stages of the reduction sequence (such as initial flakes and/or residual fragments), tools (n=27) are generally thick, with a flat surface opposite to a convex surface, with one or two backs. these backs, natural or prepared by a blow, may have played an important role in the grip and the transmission of energy (aureli et al., 2015; rocca et al., 2016). the use­wear analysis revealed traces related to action on soft or medium hard materials, especially through cutting, whittling, and scraping (aureli et al., 2016; boschin et al., 2018; rocca et al., 2016). therefore, butchery activities related to skinning or meat exploitation may have taken place at the site, although there is no evidence of cut marks (boschin et al., 2018). ficoncella was interpreted as the result of different occupations in a short time range: between the death of the elephant and its burial, the area was probably frequented alternatively in a very short period of time by animals and humans (aureli et al., 2015, 2016). however, even if we consider that the human occupation was linked to the elephant carcass (scavenging?), it is difficult to know: a) the order of their frequentation (animals/ humans) and their degrees of competition; b) if the human occupation is strictly coeval with the fauna accumulation; c) if the animals died at site due to natural factors or if their carcasses where brought there by hominins (aureli et al., 2015; boschin et al., 2018). 2.7. visogliano (friuli venezia giulia, northern italy) the visogliano shelter (110 m asl) is located in the trieste karst, in north-eastern italy. the site, discovered in 1975, yielded lithic, faunal and human remains in two distinct areas of a karstic doline originated by the collapse of a cave: in a rock shelter (shelter a) and in a cemented breccia outside the rock shelter (breccia b), about 30 m to the west of the shelter (abbazzi et al., 2000; cattani et al., 1991; tozzi, 1994). the infill deposit of the rock shelter a (about 12 m thick) is formed by: 1) an upper horizon (layer 10) formed by colluvia of red soils; 2) an intermediate horizon (layers 11-39), composed of loess or loess-like sediments, deposited during a glacial period with alternating humid-cold and dry-cold phases; 3) a lower horizon (layers 40-46), deposited in non-glacial conditions and characterised by the presence of products of the collapse of an underground karstic system. the deposit of the external breccia (breccia b), about 3m thick, is formed by very cemented layers with sedimentological and paleontological characteristics similar to the lower horizon of the shelter (abbazzi et al., 2000; cattani et al., 1991). however, a direct stratigraphical correlation between the two areas is prevented by an erosion surface, filled up with late pleistocene red soils and calcareous blocks (falguères et al., 2008). combined esr/u-series analyses dated the lower layers to a period between 350-500 ka, in agreement with micromammal and biostratigraphical studies (falguères et al., 2008). however, these dates (obtained on herbivore teeth), must be considered with caution, due to the wide error range of the oldest analysed layers and some discrepancies with faunal, stratigraphic, and pedosedimentary context. the oldest analysed layers (44 and 41) range between 482 ka (482+99/-81) and 356 ka (356+46/-41) with a wide error range of 15-20%. these ages can be compared to the direct u-series age (390+indet./-229 ka) obtained on the vis.2 mandible fragment found in the breccia layers of locus b. however, the correlation between the two areas is not secure. the combined age estimates of the intermediate layers (39-24) range between 445 and 383 ka, suggesting a contemporary deposition with the lower layers. this appears to be in contrast with the abrupt change in pedosedimentary conditions and faunal content recorded between layers 40 and 39. the available data from the uppermost layers (layers 13 and 11) provide too old ages, which are inconsistent with all the other geochronological and stratigraphic data (falguères et al., 2008). the faunal assemblage can be referred to the middle-late galerian. the entire stratigraphic sequence is dominated by microtus cf. arvalinus, and the red deer c. elaphus acoronatus (masini & sala, 2007). while crocidura, terricola, macaca, and fairly abundant fallow deer (dama clactoniana) occur in the temperate climate lower layers (abbazzi et al., 2000). the human remains are represented by five teeth, two fragments of teeth, and a fragment of jaw. four teeth were discovered in the lowest layers (45, 44, 42), which resemble the most ancient specimens of the middle pleistocene (abbazzi et al., 2000; mallegni et al., 2002). more recently, a comparative high resolution 44 muttillo b. et al. endostructural assessment of five teeth from visogliano reveals a neanderthal-like morphological dental template, clearly distinct from the modern humans (zanolli et al., 2018). on the basis of a typological analysis of the lithic industries (tab. 1), different cultural traditions were identified. while the upper horizon is characterised by frequent carinated side scrapers mostly made of silicite, in the intermediate horizon, the tool assemblage is strongly microlithic with a high percentage of denticulates. the set is made of silicite, except some rare limestone artefacts. the lithic assemblage of the oldest layers (46-40 of shelter a and almost all of breccia b) is mainly made on local limestone and more rarely on silicite and volcanic rock. the set is mostly composed of cores, choppers (cores?), flakes, and two protobifaces. the silicite assemblage shows ‘tayacian’ traits: the few tools mainly denticulates, side scrapers, quinson-type tools, and tayac points are small and thick, with a high carinal index, with a simple and semi-abrupt retouch and an often-raised quina-type retouch (abbazzi et al., 2000; grifoni & tozzi, 2006; fig. 3: 9-18). 3. discussion and conclusions this overview of the sites and lithic productions in the italian peninsula between mis 19 and mis 12 shows that archaeological data are dispersed both in time and space. in addition, different theoretical/methodological approaches have been adopted in the study of lithic assemblages, which cannot be simply superimposed to each other without previously discussing them. in some cases, different approaches have been used to study the industries coming from different layers of the same site, in parallel to the methodological changes in the course of the research history (tab. 1). the results of a holistic and homogeneous approach to the technocomplexes are not yet available, despite the efforts made in the last decade. accordingly, the informative potential of technical components may be taken with caution before using it as an index of cultural markers to identify technical traditions. the middle pleistocene opens with an absence of sites. a large chronological gap separates the late early pleistocene sites, pirro nord and ca’ belvedere di monte poggiolo, which yielded core-and-flake based technology (arzarello et al., 2012, 2016; lópez-garcía et al., 2015; muttoni et al., 2011; peretto et al., 1998), from the earliest middle pleistocene site, notarchirico, whose oldest layer is close to 700 ka. it is difficult to evaluate the duration of this interval because the ages of ~1.6-1.3 ma for pirro nord (e.g., arzarello et al., 2012; lópez garcía et al., 2015; pavia et al., 2012) and ~1.0 for monte poggiolo (falguéres, 2003; gagnepain et al., 1998; peretto et al., 1998; peretto, 2006) have been recently criticized by muttoni et al. (2011, 2018) based both on magnetostratigraphical and biochronological data. they proposed an age of >0.78 ma for pirro nord and ~0.85 ma for monte poggiolo (muttoni et al., 2011, 2018). this gap enables to discuss about a local origin of the notarchirico industries, which represent one of the earliest western european acheulean documenting the production of lcts in a period comprised between the mis17/16 transition to the beginning of mis 15 (moncel et al., 2020). moncel et al. (2020) assessed that the ability to manage bifacial volume is therefore observed in other acheulean sites of western europe dated between 700 and 600 ka (antoine et al., 2016; ashton & white, 2003; despriée et al., 2011; hurel et al., 2016; iovita et al., 2017; mcnabb et al., 2018; moncel et al., 2013, 2016a, 2016b, 2018, 2019). accordingly, notarchirico is interpreted not as an isolate case, but as part of a common background documenting a technological shift from preexisting industries. however, e. nicoud (2011, 2013), using a different approach, argued that lcts from notarchirico sequence do not belong to a bifacial shaping procedure, but they are just the products of short chaînes opératoires for cobble tool manufacture. beyond the different interpretations, it is clear that the number of artefacts that can be attributed to the handaxe sensu lato category (to avoid the controversial uses of the term “biface”) is limited compared to the other components of the lithic assemblages (moncel et al., 2019; santagata, 2016; tab. 1). a recent review of the industries of the nearby cimitero di atella site reconsidered the attribution of many artefacts to handaxes, that are very poorly represented (abruzzese et al., 2016). notarchirico and cimitero di atella yielded also archaeological layers without lcts. the alternance of “bifacial” and “non bifacial” units has been interpreted as the co-existence of human species that produced different technologies, or as the outcome of different functional needs (gallotti, 2016; santagata, 2016). at the current state of knowledge, a detailed reconstruction of the early middle pleistocene technical behaviours in this area of the venosa basin is premature. it is equally premature to explain the presence/absence of lcts both from techno -economic, techno-functional, and human biological perspectives. firstly, the partial knowledge of the small flaking systems does not allow: 1) to analyse similarities and/or differences precisely in that production which is present in all layers of the sequence; 2) to identify the number and relationships between the different chaînes opératoires; 3) to interpret the status of the production of lcts in the technical system. the contextual absence of taphonomic and functional data for most part of the archaeological layers does not allow to evaluate the role played by post-depositional processes and functional needs in the composition of the different lithic assemblages. even if the production of lcts from notarchirico shares a common technological background on a western european scale, it remains a sporadic phenomenon on a local scale both at notarchirico and at cimitero di atella. at ~500 ka, the production of lcts disappears in the venosa basin, as documented by the layer a industry of the loreto site (crovetto, 1993). this evidence could be even more significant if we consider that, regardless the approach in lithic studies, lcts production is almost totally absent in lithic assemblages between mis 15 and mis 12, before a surge from mis 11 onwards. many scholars have repeatedly highlighted how the numerically consistent presence of small tools in sites 45 lithic productions of the middle pleistocene in the italian peninsula with core-and-flake based assemblages is a common trait in the italian peninsula between mis 15 and mis 12. following a typological approach in small and large tool analysis, grifoni & tozzi (2006) identified the emergence of cultural traditions in this period: 1) a ‘tayacian’ group, characterised by small lithic industry; 2) a ‘denticulate’ group found exclusively in visogliano a; 3) a ‘clactonian’ group characterised by large, thick, but rarely carinated flakes, a large number of scrapers, few denticulates, absence or exceptionality of handaxes; 4) an ‘acheulean’ group. although this analysis also includes sites without an indisputable stratigraphic context and chronological constraints and although the research advancement has led to the abandonment of terms such as ‘tayacian’ and ‘clactonian’, results show the difficulty of typologically grouping the industries of the first half of the middle pleistocene into a uniform entity. the role played by small tools in drawing technical scenarios was earlier underlined by l. cattani et al. (1991) and c. crovetto (1993), who pointed out their technical similarities among loreto, isernia, visogliano, and penecontemporaneous central european sites. recent techno-functional studies compared assemblages from central europe with italian sites confirming that small tools share the same “tools conception” (aureli et al., 2015, 2016; rocca 2016a, 2016b, rocca et al., 2016). r. rocca (2016a, 2016b) identified in central europe assemblages lacking lcts characterised by a great variability of small tools on different types of blanks and the presence of original technical traditions. however, small tools are also present in western european assemblages containing lcts (nicoud, 2013; rocca, 2013; rocca et al., 2016). a high percentage of small tools has been assessed also at isernia la pineta thanks to a technological revision of the layer t.3c industry (gallotti & peretto, 2015). the technical features described are shared by other western european sites dated between ~0.8 and ~0.6 ma, independently from the occurrence of lcts. this is relevant in cultural terms, as the same technological knowledge seems to be shared by knappers in a specific time period. it is evident that the technical behaviours dated between mis 17/16 and mis 12 in the italian peninsula are extremely diversified. the research of the last decade allowed to refine the chronostratigraphic framework of some sites and to investigate the "non-lcts" component in greater detail. however, a homogeneous and comprehensive study of all lithic series from stratigraphic contexts is still lacking and prevents the possibility of detailed comparisons among the various industries of the italian peninsula and of evaluating them in a european context. acknowledgements we are grateful to the editor and the reviewers for having contributed to the improvement of this paper. special thanks to elisa nicoud who kindly provided drawings of artefacts from valle giumentina. author contributions b.m., r.g. and g.l. conceived and designed the paper. b.m. wrote the paper with the contribution of r.g. and g.l. all authors discussed the results and contributed to the final manuscript. references abbazzi l., fanfani f., ferretti m.p., rook l., cattani l., masini f., mallegni f., negrino f. tozzi c. (2000) new human remains of archaic homo sapiens and lower palaeolithic industries from visogliano (duino aurisina, trieste, italy). journal of archaeological science, 27, 1173-1186. doi: 10.1006/jasc.1999.0541 abruzzese c., aureli d., rocca r. (2016) assessment of the acheulean in southern italy: new study on the atella site (basilicata, italy). quaternary international, 393, 158-168. doi: 10.1016/j.quaint.2015.06.005 accorsi c.a., cremaschi m., mercuri a.m. (1996) qualche dato sul paesaggio dell'accampamento paleolitico di isernia (molise, italia centrale): dati litostratigrafici e spettri pollinici della serie “isernia fiume cavaliere. in: i reperti paleontologici del giacimento paleolitico di isernia la pineta, l’uomo e l’ambiente (ed. by peretto c.). istituto regionale per gli studi storici del molise‘‘v. cuoco’’, cosmo iannone editore, isernia, 7-23. alberdi m.t., caloi l., palombo m.r. (1988) the quaternary fauna of venosa: equids. bulletin du musée d’anthropologie préhistorique de monaco, 31, 5-39. anconetani p., peretto c. (1996) la fratturazione intenzionale delle ossa lunghe e della mandibola come indice di attività umana nel sito di isernia la pineta. in: i reperti paleontologici del giacimento paleolitico di isernia la pineta, l'uomo e l'ambiente (ed. by peretto c.). cosmo iannone editore, isernia, 453-530. angelelli f., caloi l., malatesta a., palombo m.r. (1978) fauna quaternaria di venosa: cenni preliminari. proceedings xx riunione scientifica dell’istituto italiano di preistoria e protostoria, firenze, 133140. antoine p., moncel m.-h., limondin-lozouet n., locht j. -l., bahain j.-j., moreno d., voinchet p., august p., stoetzel e., dabkowsky j., bello s.m., parfitt s.s., tombret o., hardy b. (2016) palaeoenvironment and dating of the early acheulean from the type area of the (river) somme basin (northern france): new discoveries from the high terrace at abbeville-carrière carpentier. quaternary sciences reviews, 149, 338-371. doi: 10.1016/j.quascirev.2016.07.035 arnaud j., arzarello m., lembo g., muttillo b., peretto c., rufo e. (2017) between “vintage” and “avantguard”, the lower palaeolithic settlements in molise region (italy), quaternary international, 450, 511. doi: 10.1016/j.quaint.2016.07.054 arzarello m., pavia g., peretto c., petronio c., sardella r. (2012) evidence of an early pleistocene hominin presence at pirro nord (apricena, foggia, southern italy): p13 site. quatenary international, 267, 56-61. 46 muttillo b. et al. doi: 10.1016/j.quaint.2011.01.042 arzarello m., de weyer l., peretto c. (2016) the first european peopling and the italian case: peculiarities and “opportunism”. quaternary international, 393, 41-50. doi: 10.1016/j.quaint.2015.11.005 ashton n., cook j.m., lewis s.g., rose j. (1992) high lodge: excavations by g. de g. sieveking, 1962-8 and j. cook, 1988. british museum press, london. ashton n.m., mcnabb j., irving b., lewis s.g., parfitt s. (1994) contemporaneity of clactonian an acheulian flint industries at barnham, suffolk. antiquity, 68, 585-589. doi: 10.1017/s0003598x00047074 ashton n.m., white m. (2003) bifaces and raw materials: flexible flaking in the british early palaeolithic. in: multiple approaches to the study of bifacial technology (ed. by soressi m., dibble h.). university museum monography 115, university of pennsylvania, philadelphia, 109-124. aureli d., contardi a., giaccio b., modesti v., palombo m.r., rozzi r., sposato a., trucco f. (2012) straight-tusked elephants in the middle pleistocene of northern latium: preliminary report on the ficoncella site (tarquinia, central italy). quaternary international, 255, 29-35. doi: 10.1016/j.quaint.2011.06.052 aureli d., contardi a., giaccio b., jicha b., lemorini c., madonna s., magri d., marano f., milli s., modesti v., palombo m.r., rocca r. (2015) palaeoloxodon and human interaction: depositional setting, chronology and archaeology at the middle pleistocene ficoncella site (tarquinia, italy). plos one, 10(4), e0124498. doi: 10.1371/journal.pone.0124498 aureli d., rocca r., lemorini c., modesti v., scaramucci s., milli s., giaccio b., marano f., palombo m.r., contardi a. (2016) mode 1 or mode 2? “small tools” in the technical variability of the european lower palaeolithic: the site of ficoncella (tarquinia, lazio, central italy). quaternary international, 393, 169-184. doi: 10.1016/j.quaint.2015.07.055 ballatore m., breda m. (2013) stephanorhinus hundsheimensis (rhinocerontidae, mammalia) teeth from the early middle pleistocene of isernia la pineta (molise, italy) and comparison with coeval british material. quaternary international, 302, 169 -183. doi: 10.1016/j.quaint.2013.02.002 barsky d., de lumley h. (2010) early european mode 2 and the stone industry from the caune de l’arago’s archeostratigraphical levels “p”. quaternary international, 223-224, 71-86. doi: 10.1016/j.quaint.2009.12.005 belli g., belluomini g., cassoli p.f., cecchi s., cucarzi m., delitala l., fornaciari g., mallegni f., piperno m., segre a.g., segre-naldini e. (1991) découverte d’un fémur humain acheuléen à notarchirico (venosa, basilicata). l’anthropologie, 95, 47-88. böeda e. (2001) determination des unités tecnofonctionnelles de pièces bifaciales provenant de la couche acheuléenne c'3 base du site de barbas i. in: les industries à outils bifaciaux au paléolithique moyen d’europe occidentale (ed. by cliquet d.). actes de la table ronde internationale, caen (basse-normandie, france) le 14-15 octobre 1999, eraul, liège, 98, 51-76. bonifay m.f. (1977) liste préliminaire de la grande faune du gisement préhistorique de venosa (basilicata, italie): fouilles 1974-76. bulletin du musée d’anthropologie préhistorique de monaco, 21, 116-125. borzatti von löwenstern e., sozzi m., vanucci s., vianello f. (1990) l’acheuleano del cimitero di atella. prime indagini sulla stratigrafia del sedimento e sulle industrie litiche. studi per l’ecologia del quaternario, 12, 7-13. borzatti von löwenstern e., sozzi m., vanucci s. (1992) i manufatti preistorici in radiolarite porosa del cimitero di atella. studi per l’ecologia del quaternario, 14, 7-13. borzatti von löwenstern e., palchetti a., sozzi m. (1997). témoignages de l'acheuléen inférieur en italie méridionale, le gisement du cimitero di atella (basilicata). l'anthropologie, 101, 617-638. borzatti von löwenstern e. (1998) il bacino di atella nella preistoria. studi per l'ecologia del quaternario, 20, 7-39. boschin f., rocca r., aureli d. (2018) new archaeozoological and taphonomic analysis on macroand megafauna remains from the lower palaeolithic site of ficoncella (tarquinia, central italy). quaternaire, 29(1), 45-51. doi: 10.4000/quaternaire.8607 brancaccio l., cinque a., di crescenzo g., santangelo n., scarciglia f. (1997) alcune osservazioni sulla tettonica quaternaria nell'alta valle del fiume volturno (molise). il quaternario, 10, 321-328. breda m., peretto c., thun hohenstein u. (2015) the deer from the early middle pleistocene site of isernia la pineta (molise, italy): revised identifications and new remains from the last 15 years of excavation. geological journal, 50, 290-305. doi: 10.1002/gj.2646 brocchini d., la volpe l., laurenzi m.a., principe c. (1994) storia evolutiva del monte vulture. plinius, 12, 22-25. bulgarelli g.m., capano a., piperno m. (1999) le ricerche preistoriche nel bacino di venosa. in: notarchirico. un sito del pleistocene medio-antico nel bacino di venosa (basilicata) (ed. by piperno m.). osanna, venosa, 3-135. caloi l., palombo m.r. (1979a) la fauna quaternaria di venosa: canis sp. quaternaria, 21, 115-128. caloi l., palombo m.r. (1979b) megaceros solilhacus (robert) da terranera (bacino di venosa, potenza). quaternaria, 21, 129-138. caloi l., palombo m.r. (1980) la fauna quaternaria di venosa: bovidi. bollettino società geologica d’italia, 100, 101-140. carbonell e., garcía-antòn m.d., mallol c., mosquera m., ollé a., rodríguez x.p., sahnouni m., sala r., vergés j.m. (1999) the td6 level lithic industry from gran dolina, atapuerca (burgos, spain): 47 lithic productions of the middle pleistocene in the italian peninsula https://doi.org/10.1002/gj.2646 production and use. journal of human evolution, 37, 653-693. doi: 10.1006/jhev.1999.0336 caruso c., giannandrea p., perri e. (2012) preliminary observations on continental carbonate clasts in alluvial/volcanoclastic deposits (pleistocene, venosa basin, southern italy). rendiconti online della società geologica italiana, 21, 1035-1037. cassoli p.f., di stefano g., tagliacozzo a. (1999) i vertebrati dei livelli superiori a ed alfa della serie stratigrafica di notarchirico. in: notarchirico. un sito del pleistocene medio-antico nel bacino di venosa (basilicata) (ed. by piperno m.). osanna, venosa, 361-438. cattani l., cremaschi m., ferraris m.r., mallegni f., masini f., scola v., tozzi c. (1991) le gisement du pléistocène moyen de visogliano (trieste): restes humains, industries, environnement. l’anthropologie, 95, 9-36. cattani l. (1996) la ricostruzione dell’ambiente preistorico attraverso lo studio dei pollini. in: notarchirico, 500.000 anni fa (ed. by piperno m.). osanna, venosa, 14. cauche d., celiberti v., barsky d., notter o., bidittu i., de lumley h. (2004) les plus anciennes industries lithiques du latium, italie. in: premiers hommes et paléolithique inférieur (ed. by secrétariat du congrés). bar international series, 1272, 49-57. channarayapatna s., lembo g., peretto c., thun hohenstein u. (2018) preliminary results from application of gis to study the distribution of select taphonomic agents and their effects on the faunal remains from 3 colluvium level of isernia la pineta. quaternaire, 29, (1) 31-38. doi: 10.4000/quaternaire.8660 cohen k.m., gibbard p.l. (2019) global chronostratigraphical correlation table for the last 2.7 million years. quaternary international, 500, 20-31. doi: https://doi.org/10.1016/j.quaint.2019.03.009 coltorti m., cremaschi m. (1983) depositi quaternari e movimenti neotettonici nella conca di isernia. contributi conclusivi per la carta neotettonica d'italia, consiglio nazionale richerche. progresso finalizzato geodinamica, 506, 173-198. coltorti m., feraud g., marzoli a., peretto c., ton-that t., voinchet p., bahain j-j., minelli a., thun hohenstein u. (2005) new 40ar/39ar, stratigraphic and palaeoclimatic data on the isernia la pineta lower palaeolithic site, molise, italy. quaternary international, 131(1), 11­22. doi: 10.1016/j.quaint.2004.07.004 crovetto c. (1993) le paléolithique inférieur de loreto (venosa, basilicata, italie). bulletin du musée d’anthropologie préhistorique de monaco, 36, 3157. crovetto c. (1994) le industrie litiche. analisi tecno tipologica dei reperti di scavo. in: le industrie litiche del giacimento paleolitico di isernia la pineta, la tipologia, le tracce di utilizzazione, la sperimentazione (ed. by peretto, c.). cosmo iannone editore, isernia, 183-353. delagnes a., roche h. (2005) late pliocene knapping skills: the case of lokalalei 2c, west turkana, kenya. journal of human evolution, 48, 435-472. doi: 10.1016/j.jhevol.2004.12.005 de lumley h., de fournier a., park y.c., yokoyama y., demouy a. (1984) stratigraphie du remplissage pléistocène moyen de la caune de l'arago à tautavel. etude de huit carottages effectués de 1981 a 1983. l'anthropologie, 88, 5-18. delvigne v., fernandes p., tuffery c., raynal j.-p., klaric l. (2020) taphonomic methods and a database to establish the origin of sedimentary silicified rocks from the middle-recent gravettian openair site of la picardie (indre-et-loire, france). journal of archaeological science: reports, 32, 102369. doi:10.1016/j.jasrep.2020.102369 demangeot j., radmilli a.m. (1966) le gisement paléolithique de valle giumentina (appennin central) et ses problèmes. eiszeitalt. ggw., 17, 159-199. despriée j., voinchet p., tissoux h., bahain j.-j., falguères c., courcimault g., dépont j., moncel m.-h., robin s., arzarello m., sala r., marquer l., messager e., puaud s., abdessadok s. (2011) lower and middle pleistocene human settlements recorded in fluvial deposits of the middle loire river basin, centre region, france. quaternary science reviews, 30(11-12), 1474-1485. doi: 10.1016/j.quascirev.2011.02.011 di muro a. (1999) inquadramento tefrostratigrafico del sito acheuleano del cimitero di atella (basilicata e italia). studi per l'ecologia del quaternario, 21, 714. falguères c., bahain j.-j., tozzi c., boschian g., dolo j.-m., mercier r., valladas h., yokoyama y. (2008) esr/u-series chronology of the lower palaeolithic palaeoanthropological site of visogliano, trieste, italy. quaternary geochronology, 3, 390-398. doi: 10.1016/j.quageo.2008.01.007 forestier h. (1993) le clactonien: mise en application d'une nouvelle méthode de débitage s'inscrivant dans la variabilité des systèmes de production lithique du paléolithique ancien. paléo, 5, 53-82. gagnepain j. (1996) etude magnétostratigraphique de sites du pléistocène inférieur et moyen des alpesmaritimes et d’italie : grotte du vallonet, marina airport, ca’belvedere di monte poggiolo, isernia la pineta, venosa loreto. thèse du muséum national d’histoire naturelle, paris, 3. gagnepain j., laurent m., bahain j.-j., falguères, c., hedley i.g., peretto c., wagner j.-j., yokoyama y. (1998) synthèse des donnes paléomagnétiques et radiochronologiques du site de ca' belvedere di monte poggiolo (romagne, italie) et de son environment geologique. proceedings xiii uispp congress, 6, 877-888. gallotti r., peretto c. (2015) the lower/early middle pleistocene small débitage productions in western europe: new data from isernia la pineta t.3c (upper volturno basin, italy). quaternary international, 357, 264­281. doi: 10.1016/j.quaint.2014.06.055 giannandrea p., la volpe l., principe c., schiattarella 48 muttillo b. et al. https://doi.org/10.1016/j.jhevol.2004.12.005 m. (2006) unità stratigrafiche a limiti inconformi e storia evolutiva del vulcano medio-pleistocenico di monte vulture (appennino meridionale, italia). bollettino della società geologica italiana, 125, 67 -92. grifoni r., tozzi c. (2006) l’émergence des identités culturelles au paléolithique inférieur: le cas de l’italie. comptes rendus palevol, 5, 137-148. doi: 10.1016/j.crpv.2005.12.004 hurel a., bahain j-j., moncel m-h., vialet a., antoine p., auguste p., charlier p., coye n., favinlévêque j.-c., froment a., lebon m., limondinlozouet n., orliac r., tombret o., vercoutère c., voinchet p., zazzo a. (2016) moulin quignon: la redécouverte d’un site. l’anthropologie, 120(4), 428-438. doi: 10.1016/j.anthro.2016.05.007 inizan m. l., reduron-ballinger m., roche h., tixier j. (1999) technology and terminology of knapped stone (préhistoire de la pierre taillée 5). nanterre: crep. iovita r., tuvi-arad i., moncel m-h., despriée j., voinchet p., bahain j-j. (2017) high handaxe symmetry at the beginning of the european acheulian: the data from la noira (france) in context. plos one, 12(5), e0177063. doi: 10.1371/journal.pone.0177063 la volpe l., principe c. (1989) stratigrafia e storia eruttiva del monte vulture: revisione e aggiornamenti. bullettino del gruppo nazionale per la volcanologia, 2, 889-902. la volpe l., principe c. (1994) il monte vulture. in: geologia delle aree di avampaese. società geologica italiana 77a riunione estiva. congresso nazionale. guida alla escursione generale precongressuale e alla escursione tematica sul cretaceo murgiano, 41-55. lefèvre d., raynal j.p., pilleyre t., vernet g. (1993) contribution à la chronostratigraphie de la série de venosa-notarchirico (basilicata). proceedings xxx riunione scientifica, paleosuperfici del pleistocene e del primo olocene in italia. processi di formazione e interpretazione. istituto italiano di preistoria e protostoria, firenze, 117-128. lefèvre d., raynal j.p., vernet g., pilleyre th, piperno m., sanzelle s., fain s., miallier d., montret m. (1994) sédimentation, volcanisme et présence humaine dans le bassin de venosa (basilicata, italie) au pléistocène moyen: exemple du site di notarchirico. bulletin de la société préhistorique française, 91, 103-112. lefèvre d., raynal j.p., vernet g. (1999) un bassin, un volcan: enregistrements pléistocènes dans le bassin de venosa. in piperno m. (ed), notarchirico. un sito del pleistocene medio-antico nel bacino di venosa (basilicata). osanna, venosa, 139173. lefèvre d., raynal j.p., vernet g., kieffer g., piperno m., tagliacozzo a. (2001) hommes et volcans au pléistocène moyen dans le bassin de venosa (basilicata, italie). in: tephras, chronology, archaeology, les dossiers de l’archéo-logis no 1 (ed. by juvigné, e., raynal, j.p.). cderad éd, 175-182. lefèvre d., raynal j.p., vernet g., piperno m. (2002) volcanisme et premiers peuplements en italie méridionale : l’exemple de notarchirico (venosa, italie). in: hommes et volcans, de l’éruption à l’objet, les dossiers de l’archéo-logis no 2 (ed. by raynal, j.p., albore-livadie, c., piperno, m.). cderad éd, 67-76. lefèvre d., raynal j.p., vernet g., kieffer g., piperno, m. (2010) tephro-stratigraphy and the age of ancient southern italian acheulean settlements: the sites of loreto and notarchirico (venosa, basilicata, italy). quaternary international, 223-224, 360-368. doi: 10.1016/j.quaint.2010.02.020 lembo g. (2015) metodologie informatiche applicate agli scavi archeologici. il caso studio di isernia la pineta, 2g editrice, ferrara, 1-190. limondin-lozouet n., villa v., pereira a., nomade s., bahain j.-j., stoetzel e., aureli d., nicoud e. (2017) middle pleistocene molluscan fauna from the valle giumentina (abruzzo, central italy): palaeoenvironmental, biostratigraphical and biogeographical implications. quaternary science reviews, 156, 135-149. doi: 10.1016/j.quascirev.2016.11.029 longo l., peretto c., sozzi m., vannucci s. (1997) artefacts, outils ou supports épuisés? une nouvelle approche pour l'étude des industries du paléolitique ancien: le cas d'isernia la pineta (molise, italie centrale). l'anthropologie, 101, 579596. lópez garcía j.m., luzi e., berto c., peretto c., arzarello m. (2015) chronological context of the first hominin occurrence in southern europe: the allophaiomys ruffoi (arvicolinae, rodentia, mammalia) from pirro 13 (pirro nord, apulia, southwestern italy). quaternary science reviews, 107, 260266. doi: 10.1016/j.quascirev.2014.10.029 malerba g., thun hohenstein u., díez lomana c., rosell j., giacobini g., peretto c. (2000) cutmarks e pseudocutmarks. il problema del riconoscimento di tracce di origine antropica e non sui reperti faunistici del sito di isernia la pineta. in atti del ii convegno nazionale di archeozoologia (asti, 1997). abaco edizioni, forlì, 91-97. mallegni f., segre a.g., segre-naldini e. (1991) découverte d’un femur acheuléeen à notarchirico (venosa, basilicate). l’anthropologie, 95, 47-88. mallegni f., bertoldi f., carnieri e. (2002) new middle pleistocene human remains from northern italy. homo, 52(3), 233-239. doi: 10.1078/0018-442x-00031 marrocchino e., vaccaro c. (2006) nuove osservazioni sulla caratterizzazione petrografica della serie stratigrafica di isernia la pineta. in: preistoria in molise. gli insediamenti del territorio di isernia (ed. by peretto c. minelli a.). centro europeo di ricerche preistoriche, collana ricerche, 3, aracne editrice, roma, 26-31. masini f., sala b. (2007) largeand small-mammal distribution patterns and chronostratigraphic 49 lithic productions of the middle pleistocene in the italian peninsula boundaries from the late pliocene to the middle pleistocene of the italian peninsula. quaternary international, 160(1), 43-56. doi: 10.1016/j.quaint.2006.09.008 mcnabb j., cole j., hoggard c. s. (2018) from side to side: symmetry in handaxes in the british lower and middle palaeolithic. journal of archaeological science: reports, 17, 293-310. doi: 10.1016/j.jasrep.2017.11.008 minelli a., arzarello m., longo l., olle a., verges j.m., peretto c. (2004) new data on the lithic industry of isernia la pineta: typology, technology and functional analysis. in: proceedings xiv uispp congress, section 4, premiers hommes et paléolithique inférieur (ed. by toussaint, m., draily, c., cordy, j.-m.). bar international series 1272, oxford, 59-68. moncel m.-h., despriée j., voinchet p., tissoux h., moreno d., bahain j.-j., courcimault g., falguéres c. (2013) early evidence of acheulean settlement in northwestern europe la noira site, a 700000 year-old occupation in the center of france. plos one, 8, 1-21. doi: 10.1371/journal.pone.0075529 moncel m.-h., despriée j., voinchet p., courcimault g., hardy b., bahain j.-j., puaud s., gallet x., falguères c. (2016a) the acheulean workshop of la noira (france, 650 ka) in the european technological context, special issue first european peopling, quaternary international 393, 112-136. doi: 10.1016/j.quaint.2015.04.051 moncel m.-h., orliac r., auguste p., vercoutère c. (2016b) la séquence de moulin quignon est-elle une séquence archéologique? l’anthropologie, 120(5), 369-388. doi: 10.1016/j.anthro.2016.05.008 moncel m.-h., arzarello m., boëda é., bonilauri s., chevrier b., gaillard c., forestier h., yinghua l., sémah f., zeitoun v. (2018) assemblages with bifacial tools in eurasia (third part). considerations on the bifacial phenomenon throughout eurasia, cr palevol, special issue eurasian pleistocene (ed. by coppens y., vialet a.) 17 (1-2), 77-97. doi: 10.1016/j.crpv.2015.11.007 moncel m.-h., santagata s., pereira a., nomade s., bahain j.-j., voinchet p., piperno m. (2019) a biface production older than 600 ka ago at notarchirico (southern italy) contribution to understanding early acheulean cognition and skills in europe. plos one, 14(10), e0218591. doi: doi.org/10.1371/journal.pone.0218591 moncel m.-h., santagata c., pereira a., nomade s., voinchet p., bahain j.-j., daujeard c., curci a., lemorini c., hardy b., eramo g., berto c., raynal j.-p., arzarello m., mecozzi b., iannucci a., sardella r., allegretta i., delluniversità e., terzano r., dugas p., jouanic g., queffelec a., d’andrea a., valentini r., minucci e., carpentiero l., piperno m. (2020) the origin of early acheulean expansion in europe 700 ka ago: new findings at notarchirico (italy). scientific reports, 10, 13802. doi: 10.1038/s41598-020-68617-8 muttoni g., scardia g., kent d.v., morsiani e., tremolada f., cremaschi m., peretto c. (2011) first dated human occupation of italy at ∼0.85ma during the late early pleistocene climate transition. earth and planetary sciences letters, 307, 241252. doi: 10.1016/j.epsl.2011.05.025 muttoni g., scardia g., kent d.v. (2018) early hominins in europe: the galerian migration hypothesis. quaternary science reviews, 180, 1-29. doi: 10.1016/j.quascirev.2017.10.031 nicoud e. (2011) le phénomène acheuléen en europe occidentale: approche chronologique, technologie lithique et implications culturelles. these de doctorat, aix marseille université and università sapienza di roma. nicoud e. (2013) le paradoxe acheuléen. paris: école française de rome; comité des travaux historiques et scientifiques. nicoud e., aureli d., pagli m. (2015) comportements techniques au pléistocène moyen en italie. nouvelles recherches sur l’industrie lithique et le site de valle giumentina (abruzzes). mélanges de l'école française de rome antiquité. url: http://mefra.revues.org/2659 nicoud e., aureli d., pagli m., villa v., chaussé c., agostini s., bahain j.-j., boschian g., degeai j.p., fusco f., giaccio b., hernandez m., kuzucuoglu c., lahaye c., lemorini c., limondinlozouet n., mazza p., mercier n., nomade s., peirera a., robert v., rossi m.a., virmoux c., zupancic a. (2016) preliminary data from valle giumentina pleistocene site (abruzzo, central italy): a new approach to a clactonian and acheulian sequence. quaternary international, 409(b), 182-194. doi: 10.1016/j.quaint.2015.08.080 nicoud e., aureli d, pagli m. (2017) valle giumentina (abruzzes, italie). chronique des activités archéologiques de l’école française de rome. url: http://journals.openedition.org/cefr/1656 doi:10.4000/cefr.1656 nicoud e., villa v., guibert-cardin j., davtian g. (2020) valle giumentina (abruzzes, italie), huitième mission: étude des comportements technoéconomiques au pléistocène moyen. chronique des activités archéologiques de l’école française de rome. url: http://journals.openedition.org/cefr/4206 doi:10.4000/cefr.4206 orain r., lebreton v., russo ermolli e., sémah a.-m., nomade s., shao q., bahain j.-j., thun hohenstein u., peretto c. (2012) hominin responses to environmental changes during the middle pleistocene in central and southern italy, climate of the past, 8, 5181-5207. parés j.m., pérez-gonzalez a. (1999) magnetostratigraphy and stratigraphy at gran dolina section, atapuerca (burgos, spain). journal of human evolution, 37, 325-342. doi: 10.1006/jhev.1999.0331 parfitt s.a., barendregt r.w., breda m., candy i., collins m.j., coope g.r., durbidge p., field m., 50 muttillo b. et al. lee j.r., lister a.m., mutch r., penkman k.e.h., preece r.c., rose j., stringer c.b., symmons r., whittaker j.e., wymer j.j., stuart a.j. (2005) the earliest record of human activity in northern europe. nature, 438, 1008-1012. doi: 10.1038/nature04227 pavia m., zunino m., coltorti m., angelone c., arzarello m., bagnus c., bellucci l., colombero s., marcolini f., peretto c., petronio c., petrucci m., pieruccini p., sardella r., tema e., villier b., pavia g. (2012) stratigraphical and palaeontological data from the early pleistocene pirro 10 site of pirro nord (puglia, south eastern italy). quaternary international, 267, 40-55. doi: 10.1016/j.quaint.2010.12.019 pereira a. (2017) apport de la datation 40a/39a à la compréhension de l’évolution culturelle de prénéanderthaliens en italie centrale et méridionale entre 740 et 250 ka. phd dissertation, museum national d’histoire naturelle, paris. pereira a., nomade s., voinchet p., bahain j.-j., falguères c., garon h., lefèvre d., raynal j.-p., scao v., piperno m. (2015) the earliest securely dated hominin fossil in italy and evidence of acheulian occupation during glacial mis 16 at notarchirico (venosa, basilicata, italy). journal of quaternary science, 30(7), 639-650. doi: 10.1002/jqs.2809 peretto c. (1994) le industrie litiche del giacimento paleolitico di isernia la pineta, la tipologia, le tracce di utilizzazione, la sperimentazione. cosmo iannone editore, isernia. peretto c. (2006) the first peopling of southern europe: the italian case. c. r. palevol, 5, 283-290. peretto c., amore f.o., antoniazzi a., antoniazzi a., bahain j.-j., cattani l., callini e., esposito p., falguères c., gagnepain j., hedley i., laurent m., lebreton v., longo l., milliken s., monegatti p., ollé a., pugliese n., renault-miskovsky j., sozzi m., ungaro s., vannucci s., vergés j.m., wagner j.-j., yokoyama y. (1998) l’industrie lithique de ca’ belvedere di monte poggiolo: stratigraphie, matière première, typologie, remontages et traces d’utilisation. l’anthropologie, 102, 343-465. peretto c. (2013) isernia la pineta. cosmo iannone editore, isernia. peretto c., arnaud j., moggi-cecchi j., manzi g., nomade s., pereira a., falguères c., bahain j.l., grimaud-hervé d., berto c., sala b., lembo g., muttillo b., gallotti r., thun hohenstein u., vaccaro c., coltorti m., arzarello m. (2015) a human deciduous tooth and new 40ar/39ar dating results from the middle pleistocene archaeological site of isernia la pineta, southern italy. plos one, 10 (10), e0140091. doi: 10.1371/journal.pone.0140091 pilleyre t. (1991) datation par thermoluminescence. application à la chronologie des retombées volcaniques. thèse de l’université de clermont ii, du, 345. pilleyre t., sanzelle s., fain s., miallier d., montret m. (1999) essai de datation par thermoluminescence des dépôts du site acheuléen de notarchirico. in: notarchirico. un sito del pleistocene medioantico nel bacino di venosa (basilicata) (ed. by piperno m.). osanna, venosa, 235-243. pineda a., channarayapatna s., lembo g., peretto c., saladié p., thun hohenstein u. (2020) a taphonomic and zooarchaeological study of the early middle pleistocene 3colluvio level from isernia la pineta (molise, italy). journal of archaeological science: reports, 33. doi: 10.1016/j.jasrep.2020.102469 piperno m. (1999) paletnologia. in: notarchirico. un sito del pleistocene medio-antico nel bacino di venosa (basilicata) (ed. by piperno m.). osanna, venosa, 259-357. piperno m., tagliacozzo a. (2001) the elephant butchery area at the middle pleistocene site of notarchirico (venosa, basilicata, italy). in: the world of elephants in proceedings of the 1st international congress (ed. by cavarretta g., gioia p., mussi m., palombo m.r.). consiglio nazionale delle ricerche, roma, 230-236. preece r.c., parfitt s.a. (2012) the early and early middle pleistocene context of human occupation and lowland glaciations in britain and northern europe. quaternary international, 271, 6-28. doi: 10.1016/j.quaint.2012.04.018 radmilli a.m. (1965) abruzzo preistorico. il paleolitico inferiore-medio abruzzese. sansoni, florence. radmilli a.m. (1982) il paleolitico inferiore in abruzzo. in atti della xxiii riunione scientifica, il paleolitico inferiore in italia, firenze, 7-9 maggio 1980. istituto italiano di preistoria e protostoria, firenze, 166175. raynal j.p., lefevre d., vernet g., pilleyre t., sanzelle s., fain j., miallier d., montret m. (1998) sedimentary dynamics and tecto-volcanism in the venosa basin (basilicata, italia). quaternary international, 47/48, 97-105. doi: 10.1016/s1040-6182(97)00075-x raynal j.p., lefevre d., vernet g., papy g. (1999) un bassin, un volcan: lithostratigraphie du site acheuléen de notarchirico (venosa, basilicata, italia). in: notarchirico. un sito del pleistocene medio-antico nel bacino di venosa (basilicata) (ed. by piperno m.). osanna, venosa, 175-205. rivera peréz p. (2016) comportamiento, cultura y ambiente: variabilidad en las industrias líticas del paleolítico inferior de la europa meridional. los casos de isernia la pineta, ribeira da ponte da pedra y fonte da moita (phd dissertation), erasmus mundus joint doctorate in quaternary and prehistory, università degli studi di ferrara. rocca r. (2013) peut-on définir des aires culturelles au paléolithique inférieur? originalité des premières industries dans la moitié est de l’europe dans le contexte du peuplement de l’europe. (ph.d. thesis) université paris-ouest nanterre-la défense, france. rocca r. (2016a) depuis l’est? nouvelles perspectives sur les premières dynamiques de peuplement en europe. l’anthropologie, 120, 209-236. doi: 10.1016/j.anthro.2016.05.001 rocca r. (2016b) first settlements in central europe: 51 lithic productions of the middle pleistocene in the italian peninsula between originality and banality. quaternary international, 409(part b), 213-221. doi: 10.1016/j.quaint.2015.08.066 rocca r., abruzzese c., aureli d. (2016) european acheuleans: critical perspectives from the east. quaternary international, 411, 402-411. doi: 10.1016/j.quaint.2016.01.025 rocca r., aureli d. (2019) cimitero di atella. chronique des activités archéologiques de l’école française de rome. url: http://journals.openedition.org/cefr/3329 doi: 10.4000/cefr.3329 rocca r., da costa a., germond l., aureli d. (2020) cimitero di atella: résultats de la mission 2019. chronique des activités archéologiques de l’école française de rome. url: http://journals.openedition.org/ cefr/4436 doi: 10.4000/cefr.4436 roche h., texier p.-j. (1991) la notion de complexité dans un ensemble lithique. application aux séries acheuléennes d’isenya (kenya). in: 25 ans d’études technologiques en préhistoire: bilan et perspectives (ed. by beyries s., meignen l., texier p.-j.). proceedings xième rencontres internationales d’archéologie et d’histoire d’antibes ( 99-108). juan-les-pins: apdca. rose j. (1992) high lodge e regional context and geological background. in: high lodge: excavations by g. de g. sieveking, 1962-8, and j. cook, 1988 (ed. by ashton n.m., cook j., lewis s.g., rose j.). british museum press, london, 13-24. rufo m., minelli a., peretto c. (2009) l'industrie en calcaire du site paléolithique d'isernia la pineta: un modèle interprétatif de stratégie comportementale. l'anthropologie, 113, 78-95. doi: 10.1016/j.anthro.2009.01.001 sala b. (1996) gli animali del giacimento di isernia la pineta. in: i reperti paleontologici del giacimento paleolitico di isernia la pineta, l’uomo e l’ambiente (ed. by peretto c.). istituto regionale per gli studi storici del molise‘‘v. cuoco’’. cosmo iannone editore, isernia, 87-186. sala b. (1999) nuovi dati sulla microteriofauna di notarchirico. in: notarchirico. un sito del pleistocene medio-antico nel bacino di venosa (basilicata) (ed. by piperno m.). osanna, venosa, 439-441. santagata c. (2012) l'utilisation de roches autres que le silex au paléolithique ancien et moyen. choix économiques, techniques et fonctionnels, sur la base de l'étude des gisements de sainte-anne i (haute-loire, france) (mis 5 et 6) et de notarchirico (basilicata, italia) (mis 14 à 17). thèse de doctorat, université de bordeaux i and università sapienza di roma. santagata c. (2016) operating systems in units b and e of the notarchirico (basilicata, italy) ancient acheulean open-air site and the role of raw materials. quaternary international, 411, 284-300. doi: 10.1016/j.quaint.2015.12.074 scott g.r., gibert l. (2009) the oldest hand-axes in europe. nature, 461(7260), 82-5. doi:10.1038/nature08214. simone s. (1980) choppers et bifaces del’acheuléen méditerranéen d’après les matériaux de terra amata (a.-m., france) et de venosa (basilicata, italie). thèse doctorat d’état, université de provence. sozzi m., berna f., vannucci s. (2004) geochemical characterization of the siliceous raw materials from the acheulean site of cimitero di atella (potenza, southern italy). in: acts of the xivth uispp congress, university of liège, belgium, 2-8 september 2001, 75-84. stringer c. (2012) the status of homo heidelbergensis (schoetensack 1908). evolutionary anthropology, 21, 101-107. doi: 10.1002/evan.21311 tagliacozzo a., cassoli p.f., curdi a., fiore i. (1999) analisi tafonomica dei resti ossei del livello alfa. in: notarchirico. un sito del pleistocene medio-antico nel bacino di venosa (basilicata) (ed. by piperno m.). osanna, venosa, 455-520. thun hohenstein u., malerba g., giacobini g., peretto c. (2004) bone surface micromorphological study of the faunal remains from the lower palaeolithic site of isernia la pineta (molise, italy). in: actes du xive congrès de l’union internationale des sciences préhistoriques et protohistoriques, liegi 2-8 settembre 2001. bar international series, 1272, 123-129. thun hohenstein u., di nucci a., peretto c. (2005) lo sfruttamento di ursus deningeri nel sito paleolitico di isernia la pineta. atti iv congresso aiaz, quaderni del museo archeologico del friuli occidentale, 6, 23-29. thun hohenstein u., di nucci a., moigne a.-m. (2009) mode de vie à isernia la pineta (molise, italie). stratégie d’exploitation du bison schoetensacki par les groupes humains au paléolithique inférieur. l’anthropologie, 113, 96 110. doi: 10.1002/evan.21311 tixier j. (1956) le hachereu dans l’acheuléen nordafricain. notes typologiques. in proceedings of the xv session of the congrès préhistorique de france, july 15-22, 1956, poitiers-angoulême, 914 -923. tozzi c. (1994) il paleolitico inferiore e medio del friuli -venezia giulia. atti xxix riunione scientifica istituto italiano di preistoria e protostoria, 19-36. tuffreau a., lamotte a. (2010) oldest acheulean settlements in northern france. quaternary international, 223-224, 455. doi: 10.1016/j.quaint.2010.02.012 turq a. (1989) approche technologique et économique du faciès moustérien de type quina: étude préliminaire. bulletin de la société préhistorique française, 86(8), 244-256. van otterloo r., sevink j. (1983) the quaternary evolution of the upper volturno basin. in: isernia la pineta, un accampamento più antico di 700.000 anni (ed. by coltorti m., terzani c., cremaschi m.). calderini, bologna, 35-39. vernet g., raynal j.p., lefevre d., kieffer g. (1999) un bassin, un volcan: téphras distales dans les dépôts du pléistocène moyen de venosa (basilicata, italia). in: notarchirico. un sito del plei 52 muttillo b. et al. stocene medio-antico nel bacino di venosa (basilicata) (ed. by piperno m.). osanna, venosa, 207-233. villa i.m., buettner a. (2009) chronostratigraphy of monte vulture volcano (southern italy): secondary mineral microtextures and 39ar-40ar systematics. bulletin of volcanology, 71, 1195-1208. villa v., pereira a., chausse c., nomade s., giaccio b., limondin-lozouet n., fusco f., regattieri e., degeai j.-p., robert v., kuzucuoglu c., boschian g., agostini s., aureli d., pagli m., bahain j.-j., nicoud e. (2016a) a mis 15-mis 12 record of environmental changes and lower palaeolithic occupation from valle giumentina, central italy. quaternary science reviews, 151 (2016) 160184. doi: 10.1016/j.quascirev.2016.09.006 villa v., virmoux c., chausse c., degeai j.-p., robert v., kuzucuoglu c., boschian g., agostini s., aureli d., pagli m., nicoud e. (2016b) the long sedimentary succession of the valle giumentina basin (abruzzo, central italy): new evidence from stratigraphic studies and electrical resistivity tomography (ert). alpine and mediterranean quaternary, 29(2), 193-199. zanolli c., martinón-torres m., bernardini f., boschian g., coppa a., dreossi d., mancini l., martínez de pinillos m., martín-francés l., maría bermúdez de castro j., tozzi c., tuniz c., macchiarelli r. (2018) the middle pleistocene (mis 12) human dental remains from fontana ranuccio (latium) and visogliano (friuli-venezia giulia), italy. a comparative high resolution endostructural assessment. plos one, 13(10), e0189773. doi: 10.1371/journal.pone.0189773 zucchelli m. (2000) nuovi ritrovamenti di bos primigenius bojanus nel bacino di atella (potenza). studi per l'ecologia del quaternario, 22, 11-22. zucchelli m. (2002) i cervidi dell'acheuleano antico nel cimitero di atella (potenza). studi per l'ecologia del quaternario, 24, 13-17. 53 lithic productions of the middle pleistocene in the italian peninsula ms. received: january 15, 2021 revised: march 1, 2021 accepted: march 4. 2021 avaiable online: march 23, 2021 54 base an eighteenth century tunnel as possible archive for palaeoclimate studies vincenzo pascucci 1, luigi dallai 2, lelya zhornyak 3, giovanni zanchetta 3 1dipartimento di scienze botaniche, ecologiche e geologiche, università di sassari, sassari (italy) 2cnr-ist. geoscienze e georisorse, pisa (italy) 3dipartimento di scienze della terra, università di pisa, pisa (italy) corresponding author: v. pascucci <pascucci@uniss.it> abstract: pascucci v. et al., an eighteenth century tunnel as possible archive for palaeoclimate studies. (it issn 0394-3356, 2010) the former silva lake (present “pian del lago”, siena, italy) developed during late quaternary and formed as a poljie on the triassic limestones. the depression, nowadays completely drained, is n-s oriented, 4.5 km wide and 12 km long. the lake never exceeded 6 m in depth, and it was mainly a grassy swamp during the dry season. the lake depression is filled with 20 to 30 m of a reddish siltyclayey succession. starting from the middle age till late 18th century, the shallow waters of the lake and the humid area around acted as a swampy area infested by malaria. in 1766 a sienese nobleman, francesco bindi sergardi drained the lake excavating a drainage 2124m-long tunnel in triassic limestones to connect the silva lake with the closeby rigo creek. however, quite often the tunnel was filled with debris and the lake swamped up again. in 1780 pietro leopoldo grand duke of tuscany definitively reclaimed the silva lake and completed the construction of the drainage tunnel by paving and extending it for an additional 197 m. since then, the tunnel is called the ”canale del gran duca”. the entrance altitude of the canal is at 252 m a.s.l., and the exit is at 247 m a.s.l. the altitude difference is therefore of 5 m, and the canal floor has a slope of 0.2 %. the canal is for the most part paved but, in places, solid walls of triassic limestone are still visible. diffuse karst features are forming locally. stalactites have lengths varying from 5 to 10 cm, and flowstones occur along the tunnel walls. the presence of these speleothems has allowed geochemical investigations to establish climatic variations of the last two centuries. the tunnel was probably cleaned and well maintained for sometime after its construction (1780), and it is likely that all the remaining speleothems have developed in the last two centuries with an estimated growth of a 0.5/6 mm per year. a petrographic investigation of a well laminated flowstone with a parasitic stalagmite has been undertaken to determine the growth mechanisms. oxygen and carbon isotope data (δ18o and δ13c values) were used as indirect proxies for palaeoenvironmental reconstructions. preliminary, data show significant variations along the axis of the flowstone possibly related to environmental and climatic variations within and above the “canale”. riassunto: pascucci v. et. al., una galleria artificiale del xviii secolo come possibile archivio per studi paleoclimatici. (it issn 03943356, 2010) l’attuale pian del lago, ubicato circa 5 km a nord di siena, si è sviluppato durante il quaternario nei calcari triassici della serie toscana non metamorfica (noti anche come calcare cavernoso), come un lago di natura carsica (polje). il lago (lacus silva), oggi completamente prosciugato, orientato n-s, largo 4.5 km a lungo 12 aveva una profondità massima di circa 6m ed era utilizzato dalla vicina città di siena come riserva di pesca/caccia e di legno. la modesta profondità del lago faceva sì che nella stagione secca questo si prosciugasse quasi completamente diventando un acquitrino maleodorante infestato dalla malaria. le cronache senesi del xviii secolo parlano dei miasmi che raggiungevano la città, soprattutto durante l’estate. nel 1776 un nobil uomo senese, francesco bindi sergardi, pressato dai continui appelli dei cittadini, decise di prosciugare il lago silva, bonificandone così l’area circostante. il progetto prevedeva la costruzione di una galleria lunga 2124 m da scavare nei calcari triassici, che collegasse il lago con il torrente rigo. il progetto funzionò solo parzialmente: il canale spesso si riempiva di detriti e il lago si impaludava di nuovo. solo con l’intervento del gran duca pietro leopoldo di toscana, nel 1780, che pavimentò e allungò il canale, il lago silva fu definitivamente prosciugato. da allora il canale viene chiamato canale del gran duca. il canale parte da una quota di 252 m slm e la sua uscita si trova a 247 m. la differenza di altitudine è di 5 m con una pendenza dello 0.2%. il canale è per la maggior parte rivestito di mattoni; solo in alcuni tratti è visibile il calcare. molto diffusi sono i fenomeni carsici in formazione sia sulla volta (stalattiti di lunghezza compresa tra i 5 ed i 10 cm, vele), sia sulle pareti (depositi di scorrimento di acqua flowstones) che sul fondo (piccole vasche). la presenza di queste concrezioni (speleotemi) ha permesso di condurre alcune analisi geochimiche sugli isotopi del c e dell’o e di capire se le concrezioni presenti nel canale potessero essere usate come sistema di riferimento per lo studio delle variazioni climatiche degli ultimi due secoli. il canale del gran duca fu pulito e ben mantenuto negli anni successivi alla sua costruzione. pertanto, tutte le concrezioni presenti nel suo interno non sono più vecchie di circa 200 anni. il tasso di crescita massimo stimato è di 0.5/0.6 mm per anno. è stata condotta un‘analisi di dettaglio su di un singola concrezione di flusso con associata una stalagmite parassita. l’analisi petrografica ha mostrato che la crescita della concrezione è stata costante nel tempo e che quindi avrebbe potuto registrare tutte le variazioni climatiche succedutesi negli ultimi due secoli. le lamine dello speleotema sono state campionate ogni mm e la polvere di calcite raccolta analizzata con uno spettrometro di massa per ricavare i valori di δ18o and δ13c. le analisi preliminari condotte hanno indicato sia una buona corrispondenza tra i valori dei due isotopi che una buona correlazione tra questi e i valori di piovosità registrati nell’area senese dal 1836. questi dati dimostrano che le concrezioni presenti nel canale del gran duca hanno registrato le variazioni ambientali e climatiche succedutesi negli ultimi 200 anni e che quindi possano essere utilizzate come sistema di riferimento. keywords: palaeoclimate, stable isotopes, speleothems, lake, canale del gran duca, siena. parole chiave: paleoclima, isotopi stabili, pian del lago, canale del gran duca, siena. il quaternario italian journal of quaternary sciences 23(2bis), 2010 volume speciale 299-310 1. introduction the chronic lack of water that vexed siena during the medieval period explains the town’s preoccupation with gathering and using any available fresh water and retain as a valuable potential resource. the theme of water assumed a central importance in the history of the city of siena and forced the local authorities to construct in the 13th–15th centuries, a subterraneous network of galleries created to collect and send to the 300 v. pascucci et al. city fountains the water retrievable near siena, the so called “bottini” (costantini & martini, 2004; kucher, 2005; martini et al. 2010). the countryside farther from siena, instead, was locally richer in water, especially where, due to the geomorphology and karst features, vast ponds to shallow lakes were formed. lakes allowed the establishment of several communities and, in the middle ages, they represented important economic sources. villages and abbeys such as monteriggioni and s. leonardo al lago (figs. 1, 2) developed thanks to the presence of these lakes. special rules where established for the exploitation of the waters. in time, however, some of these lakes became the breeding grounds of malaria-carrying mosquitoes and several attempts were made to drain them. during the 18th century the lake near san leonardo (silva lake, present pian del lago) was drained with a construction of a large canal (canale del duca) cut through calcareous bedrock (fig. 2). water seeping into the canal further led to the development of several carbonate concretions (flowstones, thin stalactites and stalagmites). although in an artificial environment, these concretions have formed as part of the hydrological cycle, and have the potential to record information on the climate of the last two centuries. this paper reports on how the need for draining the infected ponds north of siena led to the construction of the canale del duca during the 18th century, and how this canal can be used nowadays to reconstruct a record of climatic changes for the last centuries. 2. geological setting the studied area is located in the western inner part of the northern apennines complex chain (vai & martini, 2001) and occupies the northernmost part of the siena graben (si). this depression is bounded to the west by the middle tuscany ridge (mtr) (pascucci et al., 1999; sagri et al., 2004) (fig. 3). this ridge is composed of low grade jurassiccretaceous metamorphic rocks that are tectonically overlain by mid-late triassic limestones and anhydrites. the ridge has played an important structural palaeogeographic role through time. (a) during late miocene it prevented the marine ingression into basins located to its east and provided much of the material of the large alluvial fans developed on its southeastern flank. most of these fans are made of triassic limestones and today they contain the main freshwater resource for the city of siena (capacci et al., 2008). (b) during the pliocene, a widespread marine transgression inundated the whole area and parts of the ridge formed a series of islands along a nw-se lineament. (c) during the quaternary mtr was 700 to 800 m high and separated areas with different climatic conditions: dry to the west and relatively humid to the east. these humid conditions likely led to the development of karst, lakes and river systems (mancini, 1962; ghinassi & magi, 2004). most of the karst features occurring in the studied area developed into the triassic calcare cavernoso limestone. they form a complicate underground system made of various-size caves and connecting tunnels with several sinkholes (some time connected to form a polje) at the surface (pascucci & dallai, 2004). 3. history of usage of water resources since roman times, a careful management of water resources deriving from the presence of ponds fig. 1 schematic map of tuscany with location of the lacus silva (size of the lake not to scale), siena and monteriggioni. mappa schematica della toscana con l’ubicazione del lacus silva (la dimensione del lago non è in scala), siena e monteriggioni. 301an eighteenth century tunnel as possible archive for ... fig. 2. (a) topographic map of the pian del lago plain and reconstruction of the lake size. in the map the trace of the canale del gran duca is shown by solid line. (b) at the bottom the map of the map of the canal (after dei, 1887). (a) carta topografica di pian del lago e ricostruzione dei sui contorni. sulla carta è riportata l’ubicazione del canale del gran duca con linea piena. (b) in basso la pianta del canale (da dei, 1887). (a) (b) 302 was typical both of the coastal and inland areas. coastal lagoons and inland lakes and ponds have strongly influenced the economy of numerous communities such as those of the medieval cities of pisa and lucca (wickham, 2001; sarti et al., this volume). in medieval tuscany, lagoons and ponds were intensely used exploiting, for example, vegetation in agriculture (the ditch reeds were used as a light support for vineyards, shrubs for bedding or as a building material for huts; cammarosano, 1983), and obtaining food by fishing and hunting. these environments were very valuable and they were managed but not drained for a considerable long time, until the 17th and 18th centuries. in the 13th century siena established an area for fish and wood provision close to the city, strictly protected by written rules for its maintenance. this area called “silva lacus”, the (silva lake – lake of wood), corresponds to the current pian del lago plain (figs. 1, 2). the “silva lacus” laws established a strict limit of fishing activities, and the punishments were listed in a specific chapter of the sienese constitution, dating back to 1262, entitled:“de pena piscantium in lacu silve” (about the punishments for fishing in silva lake):“…et in lacu de silva piscari non permittam in toto meo termino; et si quis contra fecerit, totiens xl sol. sibi auferam, quotiens contra fecerit et ibi piscatus fuerit …” the application of this law was entrusted to a special guard corps, called forestarii; “…teneatur dicti forestarii rumpere et frangere tramallium et guadam et rete et omne argumentum, cum quo aliquis piscatur, ita minutatim quod ab inde in antea non possit cumeo piscari;et potestati renunctiare postea teneatur, qualiter et quomodo fecerint …” (zdekauer, 1974; pascucci & dallai, 2004). the rude attitude of the forestarii, so clearly described in the sienese laws is similar to that of the “silvani” or “custodes” which were engaged by the canonicals of the cathedral of santa maria in pisa, in order to dissuade the abbot of the monastery of san rossore from the use of the silva tumulus, the a lagoon located north of the arno river mouth (pisa, fig. 3), the ownership of which was disputed between the two ecclesiastic entities (these documents refer to the years 1155–1156) (wickham, 2001). the silva lake developed during late quaternary and formed as a polje on the calcare cavernoso limestone. the depression is n-s oriented, 4.5 km long and fig. 3 schematic geological map of tuscany (italy) to show major tertiary basins and magmatic centres, with ages of igneous activity in millions of years before present. sl= location of the silva lake. el = elsa basin, mtr = middle tuscany ridge, ra = radicofani basin, si = siena basin, p-f = piombino-faenza line (major transverse lineament), vo = volterra basin. pratomagno corresponds to the apennine crest. inset shows study area within western europe. (modified after pascucci et al. , 2007). carta geologica schematica della toscana (italia) dove sono indicate i principali bacini terziari ed i centri magmatici con le età di attività espresse in milioni di anni. sl= ubicazione del lago silva. el = bacino dell’elsa, mtr = dorsale medio toscana, ra = bacino di radicofani, si = bacino di siena, p-f = linea piombino-faenza (uno dei principali lineamenti trasversali), vo = bacino di volterra. pratomagno corrisponde al crinale appenninico. nell’inserto è riportata l’europa occidentale. (da pascucci et al. , 2007). v. pascucci et al. 303 12 km wide. the lake never exceeded 6 m in depth, and it was mainly a marshy plain during the dry season. the shallow marshy lakes became a breeding ground for malaria-carrying mosquitoes. this combined with the strong bad odour caused by rotting vegetation, which during the dry period reached the city of siena, induced a nobleman (belonging to the contrada della selva), francesco bindi sergardi, to reclaim the lake in 1764. the project presented by bindi sergardi was anomalous for those times because it required the construction of a 2 km long tunnel through the bounding calcare cavernoso hills to drain the water from the lake to the rigo creek (fig. 2a). the 2173 m long tunnel was excavated (fig. 2b) from 1764 to 1777 with a total expense of 36,000 “scudi” that eventually led bindi sergardi to bankruptcy. the lake was temporarily drained, but quite often the tunnel became clogged with debris and the area swamped up again. in 1777 pietro leopoldo grand duke of tuscany, under strong pressure of bindi sergardi and with other 3000 scudi, paved and extended the tunnel for 197 m. in 1780 the silva lake was definitively drained leaving a flat land now called “pian del lago” (figs. 2, 4a).the original depression is filled fig. 4 (a) flat lacustrine terrain of pian del lago as it is today, surrounded by hills. (b) sign marking the entrance to the canale del gran duca and its length; (c) pyramid near the entrance of the canal (location – piramide – is on fig. 2a). (d) the exit of the canal along the rigo creek. (a) il territorio pianeggiante di pian del lago delimitato da rilievi collinari come si presenta oggi. (b) targa indicante l’inizio del canale del gran duca e la sua lunghezza. (c) la piramide che segna l’ingresso del canale (ubicazione in fig. 2a). (d) l’uscita del canale nel torrente rigo. an eighteenth century tunnel as possible archive for ... 304 with 20 to 30 m of a reddish silty-clayey lacustrine succession lying on triassic limestone (calcare cavernoso) and/or miocene conglomerate/breccia mainly made of triassic limestone. the drainage tunnel is called the canale del gran duca (grand duke canal) in honour of the duke (dei, 1887) (fig. 4b). the entrance altitude of the canal is at 252 m a.s.l., and the exit is at 247 m a.s.l. the altitude difference is therefore 5 m, and the floor of the canal has a constant slope of 0.2 %. the canal starts at the se margin of pian del lago plain, a pyramid (masonic symbol to which the grand duke belonged) marks the entrance (cioli et al., 2000) (figs. 2, 4c) and ends in the rigo creek (figs. 2, 4d). the canal was tunnelled following the easier route rather than the straightest, and bends were made (the first after 620 m from the entrance) (fig. 2b) to bypass thick, hard limestone layers. the maximum depth of the tunnel from the surface is 22 meters and 22 wells were used for aeration and to carry out the excavated material (only 10 of them are still visible) (fig. 5a). the canal has a barrel vault, generally 2.85 m high and 2.25 m wide; it is for the most part paved and the walls are covered by bricks (figs. 5b, c). however, in places, solid walls of triassic limestone are still visible. because it has been excavated in limestone, diffuse karst features were formed (figs. 6a, b). speleothems are mostly developed in the central part of the canale del gran duca. they consist of draperies, soda-straw stalactites and flowstones. the first two formed on the vault by water seepage between bricks (fig. 6a). the second formed where drainage holes were purposively left on the brick walls (fig. 6b). some incipient stalagmites may form as well but their growth is limited by the water flowing through the canal (figs. 5c, 6).the tunnel was probably cleaned and well maintained during and after its construction (1780), and it is reasonable to assume that all the still existing speleothems have developed in the last two centuries. 4. climatic proxy records for the last two centuries 4.1 samples and analytical methods a compact well laminated flowstone collected in the central part of the canal has been investigated petrographically and geochemically to determine its growing conditions (fig. 6b). different from most of the flowstones sampled along the canal, it is active and shows poor contamination from detrital material, and moderate to low porosity. petrographic investigations indicate that this flowstone grew continuously through time. it is composed of several aggrading “fan” body-like laminas with a maximum linear thickness of 141 mm (fig. 7). assuming a continuous growth of the speleothem for the 200 years from the time routine cleaning of the canal ceased soon after its final construction and the time of ur sampling (2006), the estimated rate of growth is about 0.5-0.6 mm/yr. fig. 5 (a) one of the wells drilled to remove the excavated material and for aeration. (b) the pavement and vault of the canal close the entrance. (c) water still flowing inside the canal (middle part). (a) uno dei pozzi che servivano per il trasporto in superficie del materiale scavato e per areazione. (b) pavimento e la volta del canale nei pressi dell’ingresso. (c) acqua che scorre sul fondo nella parte intermedia del canale. v. pascucci et al. the internal stratigraphy of the flowstone has been reconstructed using different sections and the best developed surfaces were sampled every 1 mm with a drill of 0.7 mm diameter (fig. 8) for isotopic analyses. this should give an average record resolution of ca. 2.5 yr (figs. 7, 8). powdered samples were first h3po4-digested, and the produced gas was cryogenically purified and then measured for 18o/16o and 13c/12c ratios with a thermofisher delta xp isotope ratio mass spectrometer at the cnr-igg of pisa. isotopic results are reported using the conventional δ notation in per mille (‰), and normalized to the vienna standard mean oceanic water (v-smow) and vienna pee dee belemnite scale (v-pdb) using internal working standards of carrara marble. these latter standards were cross-checked against the international standards nbs18 and nbs19. mean analytical precision for both δ18o and δ13c is usually better than 0.1‰. replicate measurements were made where adjacent sample results differed by ≥0.4‰. to test calcite precipitation and parameters influencing calcite deposition preliminary sampling of calcite-rich dripping waters was carried out during the several visits to the canal. waters were collected from drips form sodastraw stalagmites and from micro-pools formed at the base of brick walls. 5. results and discussion chemical and physical parameters of speleothems, such as lamina thickness, crystal morphology and stable isotopic composition record potential information on palaeoclimate (fairchild et al., 2006). the flowstone isotopic record shows significant variability both in the carbon and oxygen isotopic composition indicating decadal scale environmental variability. noticeably, the carbon and oxygen isotopic trends are substantially matching (fig. 9). this covariance may result from kinetic fractionation during calcite precipitation, but in most cases it is a genuine environmental and climatic signal (mickler et al., 2006). the δ13c values are in good agreement with data from temperate regions, usually between -4‰ and -12 ‰, where a significant soil cover occurs, and the 13c/12 ratios of speleothemic carbonate are influenced by the isotopically light soil co2 produced by plant respiration (lauritzen & lundberg, 1999; mcdermott, 2004). changes in δ13c values could be tentatively related to changes of co2 production in the soil present above the canal. increases in rainfall and 305 fig. 6 (a) stalactites and draperies on the vault of the canal. (b) flowstones on the walls of the canal (bricks are 30x20 cm). (a) stalattiti e vele nella volta del canale. (b) depositi di scorrimento di acqua sui muri del canale (i mattoni sono 30x20 cm). fig. 7 cross section of the study flowstone showing the internal fan body-like (laminar) feature at the top. holes indicate the drilled sampling points. parte superiore del deposito di scorrimento mostrante la sua struttura laminare. i buchi indicano i punti dove è stata eseguita la campionatura con il micro-trapano. an eighteenth century tunnel as possible archive for ... temperature may improve soil co2 productivity (raich & schlesinger, 1992) and reduce speleothem δ13c values (genty et al., 2003). abundant rainfall can also limit the opportunity of prior calcite precipitation during seepage (fairchild et al., 2000), a process that may enrich δ13c along the percolation pathway due to progressive degassing of co2. variations of δ18o values in speleothems can be caused by changes in cave temperature (a proxy for mean annual temperature), o-isotope composition of the source drip waters, and different in-cave physicochemical processes (evaporation due to air currents; mcdermott, 2004). in temperate regions, the δ18o values of cave drip-water reflect those of local rainfall, which in turn may vary according to changes in rainfall amount, air-mass history, condensation temperatures and global ice volumes (mcdermott, 2004). the isotopic composition of speleothem calcite within a 306 fig. 8 internal stratigraphy of the analyzed flowstone shown on different sections and the best developed surfaces. holes are made with drill of 0.7 mm diameter to collect calcite powder for isotopic analyses. stratigrafia interna del deposito di scorrimento analizzato ricostruita attraverso l’uso di diverse sezioni tagliate lungo le superfici meglio sviluppate. i buchi hanno un diametro di 0.7 mm e sono stati fatti per raccogliere polvere di calcite per le analisi isotopiche. v. pascucci et al. mediterranean environment is principally related to the isotopic composition of precipitation (which is in turn strongly related to the amount of the precipitation) rather than average temperature (bar-matthews et al., 1997, 2000; bard et al., 2002; drysdale et al., 2004; zanchetta et al., 2007). however, this relatively simple observation is complicated by several factors like the provenance of precipitation (celle-jeanton et al., 2001). figure 10 shows that the isotopic composition of the canal waters is substantially aligned along the local meteoric water line defined by longinelli & selmo (2003). this figure indicates that evaporation is not a 307 fig. 9 stable isotope compositions (δ18o and δ13c) data from the sampled flowstone. on the x axis the estimated ages are reported. composizione degli isotopi stabili (δ18o and δ13c) derivati dall’analisi del deposito di scorrimento. sull’asse delle x sono riportate le età stimate. fig. 10 relationship between δ18o and δ13c of mean monthly water samples collected in central italy (longinelli & selmo, 2003). grey circles: samples of drip waters collected in the canale del gran duca; black dot: average meteoric waters from the city of siena. relazione tra le medie mensili degli isotopi δ18o and δ13c come ricavate dall’analisi delle acque dell’italia centrale (longinelli & selmo, 2003). i cerchi in grigio sono i campioni di acqua di percolazione raccolti nel canale del gran duca. il cerchio nero è relativo ai valori misurati nelle acque meteoriche raccolte a siena. fig. 11 δ18o values and annual average rainfall as measured in the siena area from 1839 to date. correlazione tra i valori isotopici δ18o e le precipitazioni dell’area di siena misurate dal 1839. fig. 12 global average near-surface temperature annual anomalies, 1860–2003 (after jones et al., 2010). (5y = five-years running average). anomalie delle temperature annuali prossime alla superficie dal 1860 al 2003 (da jones et al., 2010). significant process affecting soil and seepage waters. although some variability may also indicate that seepage water of the grand duke canal system has different routes and residence time within the soil/epikarst zone and that it is recharged by different meteoric events. however, the average isotopic composition (δ18o: 6.0±0.5‰; δd:-39.8 ±2.9) is close to that reported for the city of siena (δ18o: -6.5 ‰; δd: -39.6, longinelli & selmo, 2003). this suggests that seepage waters are relatively well mixed and, as first approximation, the measured δ18o values represent the average local meteoric precipitation waters. accordingly, higher an eighteenth century tunnel as possible archive for ... ‰18o values in calcite are interpreted in terms of decreasing amounts of rainfall (and viceversa; zanchetta et al. , 2007). although our age model is only a preliminary approximation, two main phases of prominent reduction of rainfall (and soil co2 productivity) at ca. ad 1870–1890 and ad 1930–1950 can be envisaged, whereas a very wet phase seems to have persisted between ca ad 1810 and 1830 (fig. 11). it is interesting to note that the sharp rise in isotopic values at ca ad 1860 corresponds to the “classic” end of the little ice age (bradley & jones, 1993). this may be interpreted as an overall reduction in meteoric precipitation. a direct comparison between palaeoclimatic proxies and direct measurements can be performed using the long meteorological record available for siena (annali idrologici toscani, www.idropisa.it). temperature data derived from the siena archives can be compared with those of global average near-surface temperature annual anomalies, 1860–2003 (jones et al., 1999, 2010; parker et al., 1995) (fig. 12). the warmest global years are recorded around 1940, whereas the same period is considered the coldest around siena area (fig. 13). global temperature remained stable until 1980, from where they started to increase continuously until 2003. data relative to siena, however, indicate that temperature increased between 1986 to 1990, to drop down (still remaining 1°c higher than before) from 1991 to 2003 (fig. 14). no significant correlation can be sustained between isotopes and temperature data (even if our age model and the short period of comparison can hide any correlation) (figs. 9, 13). however, using precipitation data (figs. 11, 14) the correlation is clearer (although some relatively few adjustments are needed). periods of low rainfall recorded between 1870–1890 in the flowstone may correspond to the low rainfall period centred at about 1860 in the meteorologi308 fig. 14 rainfall data of the area of siena from 1839. (bold line=5 yr: fiveyears running average) (data from annali idrologici toscani). precipitazioni misurate a siena dal 1839 (la l inea in grassetto indica la media calcolata ogni 5 anni) (dati derivati da annali idrologici toscani). fig. 13 temperature data of the area of siena from 1926. (bold line= 5 yr: five-years running average) (data from annali idrologici toscani). temperature misurate a siena dal 1926 (la linea in grassetto indica la media calcolata ogni 5 anni) (dati derivati da annali idrologici toscani). v. pascucci et al. cal record. a better correlation exists in the recent part of the record where the very low period of rainfall inferred from isotopes between ca. 1930 and 1950 is correlated with the period centred at about 1950 in the meteorological records. it is obvious that an improved age model is essential to provide more accurate conclusions. nevertheless, our isotopic interpretation is robust (as tested in many other cases in central mediterranean even if not for so fine scale resolution; drysdale et al., 2004, 2006, zanchetta et al., 2007), and an improving of our preliminary age model will allow for a transfer function to longer study records. it is also quite clear that the observed isotopic variability cannot only result from changes of average annual climate conditions. this likely reflects a seasonal component, which can have impact on tunnel air flow and temperature, and influence the kinetics of calcite precipitation. for such reasons future research must be addressed to obtain a better constrained age model (coupled with increasing record resolution) and to improve the temperature, precipitation and humidity monitoring of the canal. 6. conclusions between 1760 and 1780 an about 2 km long canal (grand duke canal) was tunnelled to drain lake silva. part of the vault and walls of the canal are now covered by speleothems, mainly stalactites and flowstones, which record past climatic conditions. the tunnel was cleaned and well maintained after the first years of its construction. we have assumed that the speleothems have developed in the last two centuries. one flowstone was selected for study in the central part of the canal for its good quality and absence of significant growth hiatuses. data obtained from this flowstone show interesting covarying isotope trends and large variability in the environmental condition within and above the canal, of potential climatic significance. using consolidate “paradigm” on the interpretation of isotopic composition (oxygen and carbon isotope compositions) in cave carbonates from the central mediterranean, our data show an important isotopic change at about 1860, likely reflecting progressively drier conditions related to the end of the little ice age, with two prominent dry phases at 1870–1890 and 1930–1950. a better numerical geochronology is needed to constrain the correlation of the stable isotope record with the historical instrumental data. the methods here used can be tied back to ancient siena and/or similar cities, to reconstruct past palaeoclimatic conditions through man-made tunnels such as the “bottini” in siena. calibrating the results with whatever historical information are available, one could try to understand particular events that occurred in the old cities or territories possibly related to climatic changes (such as infestation of ponds, famines, floods, sicknesses). generally historical climate archives of the last 200-300 years, although not always easy to understand and to correlate to real climatic events, are relatively precise and quite often available. such as an example, we may argue that 1860 and close years were relatively dry. probably it is not only a case that at the same time around siena, baron ricasoli established the institution of the sant isodoro fest as good hope for rain (addabbo & rasmussen, 1994). 7. acknowledgments special thanks is to associazione la diana (www.ladianasiena.it) who has cleaned and is maintaining the gran duca canal active. i. peter martini, giovanni sarti and joe dewaele with their suggestions strongly improved this manuscript. 8. references addabbo b.k. & rasmussen i.l. (1994) il palio di casole d’elsa, ed. nencini, poggibonsi, 21-47. annali idrologici toscani www.idropisa.it bar-matthews m., ayalon a. & kaufman a. (1997) late quaternary paleoclimate in the eastern mediterranean region from stable isotope analysis of speleothems at soreq cave, israel. quaternary research, 47, 155–168. bar-matthews m., ayalon a. & kaufman a. (2000) timing and hydrological conditions of sapropel events in the eastern mediterranean, as evident from speleothems, soreq cave, israel. chemical geology, 169, 145–156. bard e., delaygue g., rostek f., antonioli f., silenzi s. & schrag d. (2002) hydrological conditions in the western mediterranean basin during the deposition of sapropel 6 (ca. 175 kyr). earth and planetary science letters, 202, 48–494. bradley r.s. & jones p.d. (1993) “little ice age” summer temperature variations: their nature and relevance to recent global warming trends. the holocene, 3-4, 367–376. cammarosano p. (1983) monteriggioni, storia, architettura, paesaggio. milano : electa, 1983, p. 152–156. capacci f., migliorini j. & barazzuoli p. (2008) studio idrogeologico dell’acquifero del luco (toscana, italia). giornale di geologia applicata, 8 (1), 29–39 celle-jeanton h., travi y. & blavoux b. (2001) isotopic typology of the precipitation in the western mediterranean region at three different time scales. geophysical research letters, 28, 1215–1218. cioli l., de sio f., micheli l., ottanelli a. & tognetti a. (2000) la galleria di pian del lago “ il canale del granduca”. talp, 19, 50–55. costantini a. & martini i.p. (2004) siena (central italy): urban geology of a medioeval hilltop town and its bottini (underground aqueduct) and monumental fountains guidebook for field trip d01 of the 32nd international geological congress. apat– italian agency for the environmental protection and technical services, rome. 16 pp. (http://www.apat.gov.it/site/it-it/apat/ fieldtrip guidebooks/during-congress_field_trips/) costantini a. & martini i.p. (this volume) landscape influence on the development of the medieval city-state of siena, italy. il quaternario. dei a. (1887) il prosciugamento del piano del lago. notizie storiche. tipografia all’ insegna dell’ancora, siena. 309an eighteenth century tunnel as possible archive for ... drysdale r.n., zanchetta g., hellstrom j.c., fallick a.e., zhao j-x., isola i. & bruschi, g. (2004) palaeoclimatic implications of the growth history and stable isotope (δ18o and δ13c) geochemistry of a middle to late pleistocene stalagmite from central-western italy. earth and planetary science letters, 227, 215–229. drysdale r.n, zanchetta g., hellstrom j., maas r., fallick a., pickett m., cartwright i. & piccini l. (2006) late holocene draught responsible for the collapse of old world civilizations as recorded in an italian cave flowstone. geology, 34, 101–104. fairchild i.j., borsato a., tooth a.f., frisia s., hawkesworth c.j., huang y., mcdermott, f. & spiro b. (2000) controls on trace element (sr–mg) composition of carbonate cave waters: implications for speleothem climatic records. chemical geology 166, 255–269. fairchild i.j., tuckwell g.w., baker a. & tooth a.f. (2006) modification and preservation of environmental signals in speleothems. earth-science reviews 75, 105–153. genty d., blamart d., ouahdi r., gilmour m., baker a., jouzel, j. & van-exter s. (2003) precise dating of dansgaard-oeschger climate oscillations in the western europe from stalagmite data. nature 421, 833–837. ghinassi m. & magi m. (2004) variazioni climatiche, tettonica e sedimentazione al passaggio pliocene medio-superiore nel bacino del valdarno superiore (apennino settentrionale). bollettino della società geologica italiana, 123, 301–310. jones p. d., new m., parker d. e., martin s. & rigor i. g. (1999) surface air temperature and its changes over the past 150 years. reviews of geophysics, 37, 173–199. jones p.d., parker d.e., osborn t.j. & briffa k.r. (2010) global and hemispheric temperature anomalies—land and marine instrumental records. in trends: a compendium of data on global change. carbon dioxide information analysis center, oak ridge national laboratory, u.s. department of energy, oak ridge, tenn., u.s.a. doi: 10.3334/cdiac/cli.002 (http://cdiac.ornl.gov/ trends/temp/jonescru/jones.html); kucher m.p. (2005) the water supply system of siena, italy. routledge, new york & london, 115 pp. lauritzen s.e. & lundberg j. (1999) calibration of the speleothem delta function: an absolute temperature record for the holocene in northern norway. the holocene, 9(6), 659–669 longinelli a. & selmo e. (2003) isotopic composition of precipitation in italy: a first overall map. journal of hydrology, 270, 75–88. mancini f. (1962) le variazioni climatiche in italia dalla fine del riss all’olocene. bollettino della società geologica italiana, 81, 181–214 martini i.p. & sagri m. (1993) tectono-sedimentary characteristics of late miocene-quaternary extensional basin of northern appennines. earth science reviews, 34, 197–233. martini i.p., sarti g., pallecchi p. & costantini a. (2010) landscape influences on the development of the medieval–early renaissance city-states of pisa, florence, and siena, italy. in: martini i.p. & chesworth w. (eds.) landscapes and societies – selected cases. springer, dordrecht, pp. 202–221. mcdermott f. (2004) palaeo-climate reconstruction from stable isotope variations in speleothems: a review, quat. sci. rev. 23, 901–918. mickler p. j., stern l. a. & banner j. l. (2006) large kinetic isotope effects in modern speleothems. gsa bulletin, 118 (1-2), 65–81. parker d. e., folland c. k. & jackson m. (1995) marine surface temperature: observed variations and data requirements. climatic change, 31, 55–600. pascucci v. & dallai l. (2004) karst and palaeoenvironment of the siena area (central italy). field trip guide book d02, 16 pp. in: guerrieri, l., rischia, i. & serva, l. (series eds). field trip guide books, 32nd international geological conference, florence 20-28 august 2004, memorie descrittive della carta geologica d'italia, lxiii (3), from d01 to p13, apat, roma. pascucci v., merlini s. & martini i.p. (1999) seismic stratigraphy of the miocene-pleistocene sedimentary basins of the northern tyrrhenian sea and western tuscany (italy). basin research, 11, 337–356. pascucci v., martini i. p., sagri m& sandrelli f. (2007) effects of the transverse structural lineaments on neogene–quaternary basins of tuscany (inner northern apennines, italy). in: nichols g., paola c. & williams e.a. (eds.), sedimentary processes, environments and basins – a tribute to peter friend. ias, special pubblication, 37, 155–183. raich j.w. & schlesinger w.h. (1992) the global carbon dioxide flux in soil respiration and its relationship with vegetation and climate. tellus, 44b, 81–99. sarti g., bini m. & giacomelli s. (2010) the growth and decline of pisa (tuscany, italy) up to the middle ages: correlations with landscape and geology. il quaternario, 23 (2bis), 311-322. vai g.b. & martini i.p. (2001) anatomy of an orogen: the apennines and adjacent mediterranean basin. kluwer academic publishers, dordrecht. 632 pp. wickham c. (2001)paludi e miniere nella maremma toscana, xi-xiii secolo. in: martin j.m. (ed.), catrum 7. zones côtières litorales dans le monde méditerranéen au moyen âge: défense, peuplement, mise en valeur. actes du colloque international organisé par l ’école française de rome et la casa de vélasquez, en collaboration avec le collège de france et le centre interuniversitaire d’histoire et d ’archéologie médiévales (umr 5648-université lyon -c.n.r.s.-e.h.e.s.s.), rome,23-26 octobre 1996, rome-madrid, 451 pp. zanchetta g., drysdale r.n., hellstrom j.c., fallick a.e., isola i., gagan m.k. & pareschi m.t. (2007) enhanced rainfall in the western mediterranean during deposition of sapropel s1: stalagmite evidence from corchia cave (central italy) . quaternary science reviews, 26, 279–286. zdekauer l. (1974) il costituto del comune di siena dell’anno 1262. arnaldo forni editore, bologna. 310 ms. ricevuto il 23 agosto 2010 testo definitivo ricevuto il 26 ottobre 2010 ms. received: august 23, 2010 final text received: october 18, 2010 v. pascucci et al. microsoft word 02_amato_lm03.doc available online http:/amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 26 (1), 2013, 15-29 environmental changes in the boiano intramontane basin (molise, italy) since the times of ancient bovianum (ivth century bc) vincenzo amato1, pietro p.c. aucelli2, andrea capozzi3, gianfranco de benedittis4, gerardo pappone2, carmen m. rosskopf1 1 geogislab, dipartimento di bioscienze e territorio, università degli studi del molise, c.da f. lappone, pesche (is), italy 2 disam, università degli studi di napoli “parthenope”, napoli, italy 3 seconda università di napoli, maria capua vetere (ce), italy 4 dipartimento di scienze umanistiche, sociali e della formazione, università degli studi del molise, campobasso, italy corresponding author : vincenzo amato <vincenzo.amato@unimol.it> abstract: the ancient samnitic and roman towns of bovianum, located at the base of the northern slope of the matese mountains and partially extending within one of the most depressed sectors of the boiano intramontane basin, were strongly influenced by historical palaeoenvironmental changes mainly due to climatic and man-induced variations and subordinately to the effects of historical seismicity. these changes influenced the evolution in time of the urban settlement layout extensions, which shifted alternatively towards the matese slope and its piedmont area and the plain. in particular the samnitic-roman municipium (iv century b.c.-i century a.c.) was located mainly within the piedmont area and only partially within the plain, while other smaller settlements were founded at the top of the palaeosurfaces of mt. crocella and civita. from the i to the iv century a.c., the roman colonia expanded both towards the plain and the slope, thanks to the reclamation of the most depressed sectors of the plain, as well as to slope terracing and buildings, respectively. after the iv century a.c. and up until the xix-xx century ad, the plain sector was gradually abandoned, while the urban areas were mainly concentrated at the top of the civita paleosurface and within the piedmont area. within the last two centuries the plain was newly occupied, conversely the civita settlement was gradually abandoned. with the intent of investigating the main palaeoenvironmental changes and their causes, an integrated multidisciplinary analysis of the morpho-stratigraphical and historical-archaeological data was carried out. facies analyses of two core successions, retrieved from the central area of the modern village of boiano, and a critical review of archaeostratigraphical records of older archaeological excavations, allowed for the identification of 10 archaeostratigraphical units. the sedimentary succession intercepted by the core located at the base of the piedmont area base of the matese slope was made up of alternating layers of paleosols, debris cone deposits and man-induced fills, the succession coming from the core located in the plain sector, instead, by alternating layers of paleosols and fluvial marshy-deposits. the tephro-stratigraphic data allowed to chronologically constrain the uppermost 7 to 9 m thick portion of the boiano filling (named boiano upper fill) to the later upper pleistocene-holocene. archaeological data from older excavations and the archaeological remains included in the core successions then allowed to date most of the aggradation and waterlogging phases recognized in the piedmont area and plain sector, respectively. at least three debris cone deposition phases could be recognized which are chronologically constrained prior to the iv century a.c., between the iv century a.c. and the middle age and between the xvi and xix centuries ad, respectively, and can be most likely correlated with the well documented periods of climatic deterioration known as the iron age, the dark age (iv-ix centuries ad) and the little ice age (xvi-xix centuries ad), respectively. likewise debris deposition, as well as waterlogging affected the plain mainly during the above mentioned periods and can be certainly -at least partially -attributed to the mentioned periods of climate deterioration characterized by increased rainfalls and consequent rising of the ground water level. waterlogging events, however but could have been favored also by tectonic subsidence, caused by the earthquakes which affected the boiano area during the iii-ii century b.c. and in 853, 1456 and 1805 ad. keywords: geoarchaeology, archaeostratigraphy, historical environmental changes, climatic controls, molise. 1. introduction the role of climatic changes and human actions in shaping the mediterranean landscapes has been strongly debated as of the study carried out by vita finzi (1969) on the holocene evolution of mediterranean valleys. he argued that climatic changes were the main control factors for the major phases of holocene alluviation and related palaeoenvironmental changes. the fluvial succession which laid down during the most important period of late holocene alluvial aggradation is generally known as younger fill and dates back to a time period that spans from the classical age (2.5 ka bp) to the end of the late antiquity age (1.3 ka bp) (vita finzi, 1969). during this period most of the classical to late roman settlements and towns in the mediterranean were affected by several phases of alluviation which were frequent cause of their destruction or partial burial and the consequent need to rebuild or relocate elsewhere (pope & van andel, 1984; ortolani & pagliuca, 1994; giraudi, 1995; allocca et al., 2000; ortolani & pagliuca, 2003; pope et al., 2003; wilkinson & pope, 2003; giraudi, 2005; amato, 2006; giraudi et al., 2007). a last important period of alluvial aggradation affected the mediterranean valleys from the 16th to the 19th century ad-during the little ice age (lamb, 1995; baroni & orombelli, 1996; orombelli & ravazzi, 1996; bond et al., 2001; cronin et al., 2003; mann, 2003; mayewski et al., 2004; rosskopf et al., 2006; giraudi et al., 2007). during these two periods, within the low-lying amato v. et al. 16 zones of the intramontane basins of the apennine chain, the rise of underground water level led to the formation and expansion of marshy and lake environments (giraudi, 1989; berglund et al., 1996; zolitschka et al., 2000; giraudi, 2004; roberts et al., 2008; magny et al., 2011; magny et al., 2012), while shorelines, especially those including major river mouths, registered a strong progradation (aucelli & rosskopf, 2000; aucelli et al., 2011; pappone et al., 2011; amato et al., 2013; rosskopf & scorpio, 2013). based on other studies (pope & van andel, 1984; messerli et al., 2000; amato et al., 2010b) the above mentioned changes could have been caused by human impact on the environment due to deforestation, cultivation and pasture purposes or, simply, overgrazing. finally, according to other authors (see barker et al., 1978; bintliff, 1982; de menocal, 2001; barker & hunt, 2003; berglund, 2003; amato, 2006; hunt, 2006), land use changes could have contributed to such environmental changes; however, climatic changes are thought to be the most likely primary control factor. one of the zones of the mediterranean area that provide a better record of the possible relationships between human actions and environmental changes are the intramontane basins. their infillings frequently give good evidence of depositional or even erosional events and are often consistent in archaeological remains. this permits integration of geomorphologic, stratigraphic and palaeoenvironmental records with archaeological and historical data. therefore, it allows identifying and chronologically constraining the possible influence of climate changes and human actions on mediterranean landscape evolution, while assessing related possible cause-effect relationship. to improve our knowledge concerning the processes and causes responsible for recent environmental changes, we carried out an integrated study on the boiano basin, named after the major village of boiano therewith located in the central sector of the basin at the base of the northern slope of the matese mountains (fig. 1). the modern village buried archaeological layers of samnitic to roman age (referring to the ancient bovianum) and middle age to modern age. these archeological layers are object of recent and current archaeological research (see ceglia, 2005b; de benedittis et al., 2008) focusing especially on the development and extension of bovianum in historical times, without considering palaeoenvironmental and climatic perspectives. in order to assess historical environmental changes which have affected bovianum in time and, especially, the influence of climatic changes, historical seismicity and human activities, our study focuses on the archaeostratigraphic and facies analysis of the uppermost, ca. 10 m thick, part of the boiano basin infilling, which makes up the substratum of the boiano urban area and surroundings. the latter was investigated by means of two recently drilled core successions (see below) and the sedimentary successions intercepted by some small artificial trenches and archaeological excavations. 2. geological and geomorphological setting the italian apennine chain (fig. 1b) hosts several intramontane basins mainly located along its axial zone and generally nw-se and ne-sw oriented. these basins started to form during the compressional phase of plio-quaternary tectonics (corrado et al., 2000; patacca & scandone, 2007; amato et al., 2011) and subsequently evolved under the control of extensional tectonics, which has been active at least since the middle pleistocene (corrado et al., 1997; di bucci et al., 2002; di bucci et al., 2005; amato et al., 2011). from a structural perspective, these basins can be defined as tectonic depressions (graben or semi-graben), bordered and intersected by strike-slip and normal faults (corrado et al., 2000; galli & galadini, 2003; di bucci et al., 2005; amato et al., 2011). these faults are in part still active and responsible for the historical seismicity and for the overall or partial subsidence of the basins (galli et al., 2002; galli & galadini, 2003; cpti, 2004; galadini & galli, 2004, amato et al., 2012). from a geomorphological perspective, these basins are characterized by flat alluvial plains, many of which have been drained thanks to land reclamation interventions (chouquer et al., 1987; giraudi, 1989; barker & hunt, 2003; giraudi, 2004). the plains are generally located within a mountainous to hilly landscape and are characterized by border slopes whose piedmont areas have undergone huge and widespread aggradation over time, mainly due to alluvial fan deposition and the formation of colluvial, scree talus and cones. the boiano basin is one of the major intramontane tectonic basins of the molise sector in the apennine chain. these basins are located within a narrow nw-se elongated deformation belt, extending for ca. 40 km between the isernia and sepino plains (fig. 1c), and are filled with thick quaternary successions of marshy to lacustrine, volcaniclastic and alluvial deposits (russo & terribile, 1995; brancaccio et al., 2000; di bucci et al., 2002, 2005; coltorti et al., 2005; aucelli et al., 2011; amato et al., 2012; orain et al., 2012). the geological evolution of these basins has been strongly controlled by extensional fault systems since the middle pleistocene (corrado et al., 2000; di bucci et al., 2002; di bucci et al., 2005; patacca & scandone, 2007; amato et al., 2011), some segments of which are currently active (valensise & pantosti, 2001; galli et al., 2002; galadini & galli, 2004) and responsible for the main earthquakes recorded in the molise apennine (galli & galadini, 2003; cpti, 2004). the boiano basin is located at ca. 500 m a.s.l. between the matese and montagnola di frosolone carbonate massifs and the siliciclastic sannio hills (fig. 1c). it is ca. 4 km large and elongated for ca. 20 km in the nw-se direction, and is drained by the biferno river that flows to the adriatic sea (rosskopf & scorpio, 2013). the modern urban area of boiano is located at elevations of 480-500 m a.s.l. in one of the most low-lying sectors of the basin, while remnants of more ancient settlements are located on the matese slope and along its piedmont area, at elevations between 500 and 1000 m a.s.l. (fig. 2). the matese slope is characterized by a step of flat surfaces, located at elevations between 1400 and 700 m a.s.l. these surfaces are interpreted as palaeosurfaces, i.e. remnants of gently-rolling ancient landscapes, mostly carved in bedrock and now hanging at different the boiano basin since the times of ancient bovianum 17 altitudes above the local base-levels of erosion (aucelli et al., 2010; aucelli et al., 2011). their genesis is related either to prolonged periods of relative tectonic stability alternating with periods of uplift, or partially even to the interplay between steady tectonic uplift and climatic fluctuations (aucelli et al., 2011). on top of the civita and mt. crocella palaeosurfaces (fig. 2), located at ca.750 m and 1000 m a.s.l., respectively, important archaeological remnants of samnitic to middle age age (see below) have been discovered. the palaeosurfaces are connected to the plain by steep structural slopes, generated by high-angle faults which were active during the quaternary and responsible for the disarticulation of the northern front of the matese massif. the wnw-ese trending master fault is located at the base of the slope which borders the basin southwards and crosses the sw sector of the urban area of boiano. in addition to extensive tectonics, climatic changes have also contributed to the quaternary evolution of the slopes bordering boiano to the sw. during glacial periods and especially during the last one, carbonate slopes were affected by widespread slope replacement, according to the rectilinear-parallel slope recession model (young, 1972; brancaccio et al., 1979; amato et al., 2010a) and the formation of thick aggradational foot fig. 1 a) the structural sketch map of italy and location of the study area; b ) digital elevation model of the sector of the apennine chain including the boiano basin; c) geologic sketch map derived from sheet 405 (campobasso) of the new geological map of italy at scale 1:50,000 (carg project, geological survey of italy, ispra). 1: continental sediments and volcaniclastic deposits (late pleistocene-holocene); 2: foredeep and piggy-back siliciclastic deposits (miocene); 3: clays, marls and limestones (sannio unit, upper cretaceous-miocene); 4: clays, marls and limestones (molise pelagic successions, oligocene-miocene). 5: limestones, dolomites and marls of carbonate platform (a) and slope facies (b) (triassic-miocene); 6: main thrusts; 7: main extensional faults, dashed when inferred. amato v. et al. 18 slopes. the latter are made of two generations of scree deposits: the lower one, generally well cemented and with openwork texture, and the upper one, generally loose and matrix supported. the latter can be dated most likely to a period that spans from the last glacial maximum to the holocene (pappone et al., 2012), as it contains the neapolitan yellow tuff tephra dated to 15 ka bp (deino et al., 2004). the matese front in the boiano area is dissected by some gully incisions, which have contributed to build small debris cones along the southern border of the basin, and some of these extend to the boiano urban area (fig. 2). several springs feed minor watercourses and are partially captured for drinking water distribution.are situated at the base of the border slope. major watercourses coming from the border slopes have generated gentle alluvial fans extending partially within the plain (fig. 2). as the urban center of boiano is located within one of the most low-lying areas of the plain, it has a very shallow groundwater level and, therefore, is poorly drained. surface waters coming from the mountain slope are mainly drained by the calderari stream -which is also partially fed by the outflows of the maiella springs and crosses directly the urban areaand by the spin channel which is most likely of anthropogenic origins and derives part of the waters in the calderari stream (fig. 3). finally, the se sector of the boiano village is drained by the biferno river which takes its origins from the biferno springs (h in figure 3) and receives the waters of the calderari stream. two recently drilled boreholes in the urban center of boiano allowed to investigate the boiano fill succession up to a depth of 160 m (amato et al., 2012; orain et al., 2012; pappone et al., 2012). the two boreholes s1 and b6 (figs. 2 and 3), 160 m and 73 m deep, respectively, are located at ca. 100 m from each other and at 482 m and 484 m a.s.l., respectively, with the b6 core being located closer to the border slope of the plain. fig. 2 geological-geomorphologic sketch map of the south-eastern sector of the boiano basin including the village of boiano. a: location of the s. erasmo-s. chiara church archaeological excavations, b: location of the calderari archaeological area. the boiano basin since the times of ancient bovianum 19 a detailed stratigraphic and facies analysis was performed on the core successions and the most significant levels were investigated by means of tephrostratigraphy, palinology and 40ar/39ar radiometric dating (aucelli et al., 2011; amato et al., 2012; orain et al., 2012; pappone et al., 2012). the investigated part of the boiano basin infilling reaches the middle pleistocene (marine isotopic stage 13, i.e. mis13) and is made of three units: a lower unit of lacustrine-palustrine origin, chronologically constrained between the mis 13 and the mis 10 (500 ka bp350 ka bp), a middle unit of fluvial-marshy origin, constrained between the mis 10 and the mis 9 (350 ka bp250 ka bp) and an upper unit made of fluvial-marshy sediments and late pleistocene to holocene in age (boiano synthem, according to pappone et al., 2012). thanks to the presence of the neapolitan yellow tuff layer (15 ka bp, deino et al., 2004,) the boiano synthem could be divided into two sub-units that are late pleistocene and late glacial to holocene in age, respectively. a comparison of the two borehole successions allowed identifying a high angle, nw-se oriented fault which passes between the two boreholes and crosses the urban center of boiano (fig. 2). this fault has been active at least during the middle pleistocene, as evidenced by the vertical displacement of the correlated ar/ar dated tephra layers recognized in both cores (amato et al., 2012). instead, it is not clear if it has been active also during late pleistocene and holocene and whether it is currently active. the documented high historical seismicity of the boiano area may support this hypothesis. at least seven historical earthquakes occurred in 346, 848, 1293, 1315, 1349, 1456 and 1805 ad, are documented (cpti, 2004). at least the ones occurred in 346, 848, 1456 and 1805 ad caused damages in several villages located within the boiano and sepino basins (pescatore et al., 2004; de benedittis, 2012). in addition, galadini et al. (2002), galli & galadini (2003) and galadini & galli (2004) identified an earthquake which is chronologically constrained between the iii and ii century b.c. and which damaged the ercole-quirino sanctuary of campochiaro, located circa 3 km se of boiano. 3. material and methods in order to improve the currently available data on chronology and stratigraphy of the younger part of the boiano infilling as well as on the recent palaeoenvironmental evolution of the basin, we investigated in detail its uppermost portion matching it to the abovementioned late glacial-holocene sub-unit. this subunit, 7 m and 9 m thick in the b6 and s1 cores, respectively, is mainly made of alternating fluvial, debris slope and palustrine deposits, and is characterized by several unconformities and soils and is partially rich in archaeological remnants. in particular, we analyzed this sub-unit in order to define color, texture, grain features (size, shape, composition), fossil content, sedimentary and diagenetic structures, according to the methods illustrated in tucker (2011). on the basis of lithofacies, unconformities and soils, the two core successions were subdivided into stratigraphic units (us, sensu tucker, 2011). according to the soil survey staff classification (2010) concerning soils formed in aggradational and, typically, in archaeological contexts (cremaschi, 2000), we defined the soils as buried soils and, in accordance with daniels (2003), as multiple soils. in cases in which such buried soils were only made of very thin pedogenic horizons developed on their parent materials, they have been defined as buried pedogenetic horizons, according to the soil survey staff classification (2010). our palaeoenvironmental interpretations are based on the sedimentary features of the distinguished stratigraphic units and the collected historical and archaeo-stratigraphic data. with reference to the latter, first of all the archaeological content of the two cores has been analyzed from a chronologic and taxonomic perspective in order to detail the chronology of the units and the relative palaeoenvironemental changes. subsequently the archaeo-stratigraphical data coming from the archaeological excavations of s. erasmo -s. chiara church and the archaeological area following part of the calderari stream (hereinafter calderari archaeological area) (ceglia, 2005b; de benedittis, 2012), were analyzed. furthermore, we performed a critical revision of the literature dealing with historical and/or archaeological aspects of the boiano territory paying particular attention to historical sources and epigraphs dealing with the impacts of natural or man-induced changes following earthquakes, flood events, waterlogging and land reclamation. the interpretation of collected archaeostratigraphical data was supported by a detailed geomorphological analysis of the territory of boiano by means of cartographic analysis of 1:5,000 topographic sheets and field surveys. 4. results 4.1. archaeological data while the most ancient settlements discovered in the boiano basin are ascribed to the iron age (capini, 1980; ceglia, 2005a; de benedittis, 2005), the most ancient ones found within and around the modern village of boiano are samnitic in age and date to the iv century b.c. they include important defensive wall systems in polygonal work forming three separate structures (fig. 3): a first small and circle-like wall structure is located at circa 1000 m a.s.l., on top of the mt. crocella palaeosurface (de benedittis, 1995); a second one is found on top of the civita palaeosurface (750 m a.s.l., figures 2 and 3) where the discovery of several black-painted pottery findings allowed to testifying the presence of a permanent settlement that stretched over the entire civita surface (de benedittis, 1977); a third, rectangular wall structure, much larger than the other two, extends within the piedmont area of boiano village and the sector of the plain immediately in front of it and contributes to define the boundaries of the samnitic bovianum (fig. 3). the northern boundary of bovianum is evidenced by wall remains which are located in the largo gentile and palazzo quaranta subsoil (c and d respectively in fig. 3) (de benedittis, 1995; de benedittis et al., 2008), while the southern boundary can be located at the height of the s. michele arcangelo church (550 m a.s.l., e in fig. 3) (de benedittis, 1977). the eastern boundary coincides with the part of the wall structure discovered near the s. biase church (f in fig. 3). finally, the western boundary of bovianum is evidenced by the most im portant samnitic wall remains discovered in the boiano amato v. et al. 20 area up to now: ca. 15 m long, these wall remains have been unveiled during the archaeological excavation (de benedittis, 1995; de benedittis, 2004) carried out within the episcopio of s. erasmo (a in fig. 3). the western boundary of the samnitic settlement could have been influenced by the presence of the little stream which enters the plain immediately to its west, while the eastern boundary may have depended on the presence of the low lying sector of the biferno springs (h in fig. 3). in fact, in this way, the samnitic settlement was partially built on the piedmont area and partially on the plain but without including its very low lying sectors. this settlement layout of bovianum certainly persisted up until the end of the ii century b.c., as recorded by historical sources (appiano, bellum civile, i, 51) that mention the presence of the three wall systems. during this period bovianum was an important center and well connected to the main commercial and economical roads crossing the apennine chain and directed towards the tyrrhenian and adriatic coasts. bovianum was often mentioned in the writings of livio on the three samnitic wars (343-341 b.c., 326-304 b.c., 298-290 b.c.), when the romans conquered the samnitic bovianum without losing its importance (de benedittis et al., 2008). the situation changed after the social war when bovianum lost its political and cultural autonomy as mentioned by historical sources describing the sannio region as almost uninhabited and its settlements and towns as partially destroyed (strabone v, 4, 11; floro, epit., i, 16, 7-8). between the i century b.c. and the i century ad, the ancient bovianum became first a roman municipium (48-46 b.c.), then a colonia triunvirale lege iulia (44-27 b.c.) (lib. col. 231, 259 l) and, finally, a colonia flavia (73-75 ad) (la regina 1966, de benedittis 1977, 1995). during this period the historical sources mention two colonies, named boianum vetus and boianum undecumanorum (plinio, n. h., iii, 107), which could have represented the same settlement with two chronologically different urban layouts (de benedittis, 2004; de benedittis et al., 2008). the republican age settlement (i century b.c-i century ad) seems to have the same urban layout of the samnitic settlement. several archaeological data allow to hypothesize the presence of the urban area extending up to the slope of civita, with the buildings located on artificial terraces (de benedittis, 1995; de benedittis, 2004), and its abandonment during the i century ad. in fact, the archaeological excavations in the s. erasmo area (a in fig. 3) highlight that 2 m-thick debris cone deposits covered the samnitic-roman walls (de benedittis 2004; de benedittis, 2012). consequently, in the years from 73 to 75 ad, the vespasian emperor defined a new urban layout in which the urban area extended within the plain (de benedittis, 1977; de benedittis, 2004), while the low lying area of the plain was reclaimed and geometrically divided (centuratio) in order to distribute the lands to the xi legion veterans (chouquer et al., 1987; de benedittis, 2004). archaeological data related to this second fig. 3 digital elevation model of the boiano area and location of the b6 and s1 cores (green circles) and the archaeological sites (a-i, red circles) mentioned in the text. a: s. erasmo-s. chiara church; b: calderari archaeological area; c: largo gentile; d: palazzo quaranta; e: s. michele arcangelo church; f: s. biase church; g: s. bartolomeo church; h: biferno springs; i: maiella spring. the red lines and the red circle represent the remnants of the samnitic walls structures located on the piedmont area and on the civita palaeosurface, respectively. the third samnitic wall structure, which is located on the mt. crocella palaeosurface (ca. 1000 m a.s.l.), is outside the figure. the yellow dotted grid represents the layout hypothesis of roman colonia age (i-iv centuries ad). the boiano basin since the times of ancient bovianum 21 urban layout have been discovered in the calderari archaeological area (b in fig. 3): here a paved roman road (i century ad) appeared at ca. 3.5 m of depth. considering the width of this road (9.50-9.90 m) it can most likely be identified with the decumanus maximum of the settlement (chouquer et al, 1987; de benedittis, 2004; de benedittis et al., 2008). in addition, several archaeological data allow to suppose that the calderari area was the center (forum?) of the ancient village (de benedittis et al., 2008) and the decumanus maximus was the urban area thouroughfare (de benedittis, 1977; de benedittis, 1998). if this interpretation is correct, the northern boundary of the colonia can be extended north to the location of the s1 core (fig. 3). until the late roman imperial period (iv century ad), the urban layout remained unchanged (de benedittis, 1977; 2004). an epigraph, dedicated to fabio massimo, rector provinciae samnii from 353 to 357 ad, mentions the reconstruction of the secretarium (de benedittis, 1977; 1995). this document has given rise to the hypothesis that bovianum had been strongly damaged by the 346 ad earthquake (camodeca, 1971; russi, 1971; buonocore, 1992; galadini et al., 2002; galadini & galli, 2004). however, as demonstrated recently by soricelli (2009) and de benedittis (2012), it seems that this hypothesis is likely to have been given too much emphasis. after the fall of the roman empire, boiano was affected by a strong political and cultural crisis (de benedittis, 1977), and in the vi century ad the longobards conquered the sannio region. it was during this period that the urban layout gradually shifted from the plain to the slope and to the civita palaeosurface. later the urban area was rapidly relocated on the top of the civita paleosurface, further to the saracen raids and this is where nowadays the ruins dating to the xiii century ad are visible, while only a little sector of the piedmont area remained inhabited (de benedittis, 1977). successively, historical sources mention boiano (de benedittis, 1977; de benedittis, 2012) in relation to the earthquake occurred in 1456 ad, known as s. barbara earthquake. one of the effects of this earthquake was the waterlogging of the urban area, as demonstrated by the s.erasmo-s. chiara church and calderari area archaeological excavations (de benedittis, 2012). in the xvi and xvii centuries, the urban layout didn’t include the most low-lying sectors of the plain and didn’t extend up slope to the s. bartolomeo church (muccilli, 1985). the plain was newly and permanently inhabited starting only from the xix century, while the civita palaeosurface was quickly abandoned (de benedittis et al., 2008). 4.2. archaeo-stratigraphical data the presence of the reworked volcaniclastic products of the neapolitan yellow tuff (nyt in tabs. 1 and 2) dated to 15 ky bp (deino et al., 2004) in cores b6 and s1 at 7 and 9 m, respectively, allowed to constrain the chronology of the upper part of the boiano infilling (hereinafter named boiano upper fill) and to date it to the late glacial-holocene (amato et al., 2012; orain et al., 2012; pappone et al., 2012). sediment attributes and the presence of several erosional unconformities and buried soils later allowed to identify 10 stratigraphic units sensu tucker (2011) (us in fig. 4, tab. 1 and 2) which formed in different palaeoenvironmental contexts and mainly in historical times, as evidenced by diagnostic, well-dated ceramic fragments. the investigated succession of core b6 (tab. 1) is made of alternating debris cone deposits (uss 2a, 3, 6 and 8), multiple buried soils (uss 4, 5 and 7a) and man-made fills (uss 9 and 10). the core s1 succession (tab. 2) instead, is made of alternating marshy deposits (uss 2b, 4 and 7b), multiple buried soils (uss 5 and 9b) and man induced fills (us 10). the presence of diagnostic ceramic fragments within uss 4, 5 and 8 of b6 allowed the chronological constrain of these units to the iv-iii centuries b.c., the i century b.c.-i century fig. 4 stratigraphic logs of cores b6 and s1. for the description of sediment features and relative paleoenvironmental interpretation of the distinguished stratigraphic units see also table 1. amato v. et al. 22 ad and the xv-xvi centuries ad, respectively. in addition, the presence of modern-day finds and contemporary artifacts within the man-made fills of uss 9 and 10 allowed dating them to the last two centuries. the collected chronological and stratigraphic data allow to date most of the boiano upper fill to historical times, testifying a high sedimentation rate for the last 2.5 ka bp, similar to those recorded in many other sectors of the apennine chain and of the mediterranean area (younger fill, after vita finzi, 1969). the archaeo-stratigraphic data is evidence of the fact that the sedimentation was essentially fluvial-gravitational in core b6 and fluvialmarshy in core s1. in addition, two further interesting archaeo-stratigraphic successions described in de benedittis et al. (2008) and in de benedittis (2012) confirm that slope deposits are laterally heteropic to marshy sediments towards the plain. the archaeological excavation in the s. erasmo-s. chiara church area (a in figs. 2 and 3), located in the axial sector of the small debris cone affecting the modern village of boiano, showed that the western samnitic-roman walls (iv century b.c.-i century ad), founded at ca. 3 m beneath the present floor, are covered by 2 m thick debris cone deposits (fig. 5a). these debris deposits are made of two units, which are separated by man-made deposits and by the ruins of the s. chiara church, destroyed in 1456 ad by the s. barbara earthquake (de benedittis, 2012). the two distinguished phases of debris cone deposition are chronologically constrained between the i century ad and the middle age, and after the xv-xvi centuries ad and can be correlated to stratigraphic units us 6 and us 8 of core b6, respectively. conversely, the calderari archaeological area, located in the central sector of the modern village of boiano (b in figs. 2 and 3), showed that the roman colonia paved road (i century ad) (fig. 5b) has been covered by ca. 2 m thick clayey-silty deposits (ceglia, 2005b) which most likely were related to fluvial-marshy environments and testify the waterlogging of the area after the iv century ad. this road is located ca. 1 m below the present groundwater level. according to frezza (1579) and de benedittis (2012) the village of boiano suffered marshy conditions also in 853 ad and after the s. barbara earthquake. the deposits documenting these two waterlogging events form the subunits 7b and 9b of core s1. these data could confirm the hypothesis that the sector located north of the calderari stream subsided also during the middle age and modern ages. fig. 5 figures and photos illustrating some of the most significant archaeo-stratigraphic and archaeological data. a: archaeological cross section of the s. erasmo-s. chiara church archaeological area (modified from de benedittis, 2012); b: roman paved road unveiled in the calderari archaeological area (from ceglia, 2005b); c: upper part of s1 core succession, characterized by fluvial marshy sediments and buried soils with roman ceramic fragments; d: pottery fragments from cores b6 and s1: a) b6: samnitic-roman age (iv-i century b.c.), b) s1: roman age (i century b.c.-i century a.d.), c) b6: xvi century a.d., d) b6: modern and contemporary age. the boiano basin since the times of ancient bovianum 23 age us depth (m) description facies interpretation 10 b 00.60 coarse-medium sands with sub-rounded to sub-angular polygenic gravels, darkbrown clayey-silts matrix supported, especially on the top where several millimeter-sized root fragments are present. soil developed on man-made fills a 0.601.95 sub-rounded to sub-angular polygenic (mainly carbonatic) gravels and coarse sands, brownish and greyish silty-clay matrix-supported. high content of ceramic, charcoal, vegetable and bone fragments, especially concentrated in the bottom part. near the top the matrix is prevailing and the size of the gravels decrease until to 1 cm. the archaeological contents are shown in fig. 5dd. 9a b 1.952.50 coarse and medium sands with sub-rounded to sub-angular carbonatic coarse gravels, brown silts and fine sands matrix supported, especially concentrated in the top part. presence of several ceramic and cement mortar fragments of modern age. buried soil developed on man-made fills a 2.503.05 sub-angular to surrounded carbonatic coarse gravels and coarse sands, dark brown and dark-grey silty sands matrix supported. presence of several ceramics and cement mortar fragments of modern age. xvi cen. ad 8 3.053.65 openwork sub-angular to angular coarse gravels and coarse sands, mainly made by calcareous debris, ceramic and cement mortar fragments of the xvi century ad. the archaeological contents are shown in fig. 5dc. debris cone deposits 7a b 3.654.00 angular to sub-rounded coarse gravels and sands, mainly made of calcareous debris, ceramic and cement mortars fragments, dark-brown clayely silts matrix supported. presence of vegetables and charcoals remains. buried soil developed on fluvial-marshy deposits a 4.004.40 dark grey silty clays with angular to sub-rounded gravels and sands mainly made by calcareous debris and ceramic fragments. presence of charcoals and organic matter 6 4.404.70 sub-rounded to angular gravels and sands mainly made by calcareous debris and ceramic remains, dark-brown silty clays matrix supported. presence of vegetables remains and charcoals. debris cone deposits i cen. b. c. 5 b 4.705.50 dark-brown clayey silts with sub-rounded and angular gravels and coarse sands. several ceramic fragments of i century b.c. are present together with vegetable and charcoal fragments. the archaeological contents are shown in fig. 5da. buried soil developed on fluvial-marshy deposits a 5.505,70 laminated millimeter thick layers of dark-grey clayey silts and sandy-silts. several reddish-oxidized nodular concrections are present iv-iii cen. b. c. 4 b 5.706.00 brown clayey-sandy silts with sub-angular to sub-rounded coarse sands and gravels, mainly made of calcareous debris, potteries and cement mortar fragments of iv-iii centuries b.c. several millimeter to centimeter-sized charcoal and vegetable fragments are present, especially at 5,90-6,00 m. the archaeological contents are shown in fig. 5da. buried soil developed on fluvial-marshy deposits a 6.006.25 laminated millimeter thick layers of brown-grey sandy silts and dark-grey clayely silts. several reddish and dark oxidized nodular concretions are present. 3 6.256.30 open-work angular and sub-angular calcareous gravels debris cone deposits 2a 6.307.00 angular to sub-angular calcareous coarse gravels, clayey silts matrix-supported, mostly concentrated toward the top. debris cone deposits pedogenized at the top < 15 ka bp 1 7.008.30 grey-yellow silty sands mainly made of volcaniclasts (ashes and pumices). reworked neapolitan yellow tuff   tab. 1 description, archaeological constraints and facies interpretation of the stratigraphic units of b6 core succession.   age us depth (m) description facies interpretation 10 b 0-0,50 dark brown clayey silts with angular to sub-angular calcareous gravels mostly concentrated toward the top. soil developed on man-made fill a 0,502,00 sub-rounded to sub-angular polygenic (mainly carbonatic) gravels and coarse sands, brownish and greyish silty-clay matrix-supported. presence of high contents of ceramic, charcoal, vegetable and bone fragments, especially at the base. 9b 2,004,50 laminated dark and grey silty clays very rich in organic matter with veru abundant millimeter-sized root fragments, mostly concentrated toward the top buried soil developed on marshy deposits 7b a 4,505,50 laminated green-grey clays very rich in organic matter and green-orange oxidized nodular and platy oxidations (fig. 5c). marshy deposits i cen ad i cen b.c. 5 5,506,30 green-grey silty clays and sub-angular to sub-rounded calcareous gravels. several ceramic fragments dating from the i century b.c. to the i century ad, and charcoals are present. the archaeological contents are shown in fig. 5db buried soil developed on marshy deposits 4 a 6,306,50 dark-grey silty clays very rich in organic matter, burnt woods and charcoals, mostly concentrated at the top (fig. 5c) marshy deposits and burning layer 2b 6,609,00 laminated green-grey clays very rich in organic matter and green-orange oxidized nodular and platy oxidations. (fig. 5c) marshy deposits < 15 ka bp 1 b 9,009,50 grey-greenish clayey silts very rich in volcanoclasts (pumices and ashes) buried soil developed on reworked neapolitan yellow tuff a 9,509,60 yellow-orange silty sands mainly made of volcanoclasts (ashes and pumices) tab. 2 description, archaeological constraints and facies interpretation of the stratigraphic units of s1 core succession. amato v. et al. 24 5. discussion in order to illustrate the main holocene palaeoenvironmental features and changes recorded by the stratigraphic units that form the boiano upper fill, a ca. swne oriented geological section, crossing cores b6 and s1 and the archaeological excavations of s. erasmo-s. chiara church and of calderari area, has been constructed (fig. 6). starting from the reworked volcaniclastic layer of the neapolitan yellow tuff (us 1), the section crossing the two cores b6 and s1 clearly evidences the repeated lateral heteropy of slope deposits to marshy plain sediments. in the sector located near the southern border of the plain (b6), two generations of debris cone deposits (uss 2a and 3) have been deposited before the iv-iii centuries b.c. while, at the same time, marshy sediments (us 2b of s1) accumulated in the sector located northward, unfortunately these portions of the core successions do not contain chronological constraints allowing to better define the periods of sediment accumulation. the first holocene chronological constraint is found in the us 4a of core b6 (tab. 1) and is related to the iv-iii centuries b.c. the period of the samnitic bovianum, during which the three wall systems described in section 4.2 were constructed. therefore, us 4 most likely represents the buried soil of the samnitic bovianum, the layout of which persisted unchanged until the i century ad, and didn’t extend to the more central sector of the plain, i.e. the sector located northward to core b6. this hypothesis is supported by the fact that the us 4 of core s1 (tab. 2) lacks archaeological remains and is mainly made of a buried soil developed on marshy deposits. in figure 6 the supposed correlation of us 4 with the base of the samnitic walls present in the subsoil of the s.erasmo-s.chiara site, is shown. in addition, the centimeter charcoal rich layer present within the uss 4 of both cores can be interpreted as a burning layer and, by hypothesis, be correlated with the fires documented for the period of the social wars (305 b.c., 89 b.c.), which could have affected also bovianum. between the samnitic age (iv-iii centuries b.c.) and the roman municipium age (i century b.c.), a tendency to waterlogging seems to affect both sectors, as evidenced by the deposition of laminated clayey-silty sediments, very rich in organic matter and oxidized nodular and platy concretions (us 5a of core b6 and us 4 of core s1). this first period of waterlogging could have been caused by natural and/or man-induced changes. considering natural processes as driving cause, the hypothesis of climate changes as possible control factor is not supported by available regional palaeoclimatic data. therefore, rather than invoking climate changes, it is possible to relate by hypothesis this period of waterlogging to the subsidence induced by the earthquake occurred in the iii-ii centuries b.c., which affected the boiano basin and, especially, the ercole sanctuary of campochiaro (galli et al., 2002). alternatively, the social crisis that characterized this period, could also have favored the degradation of surface drainage causing or favoring waterlogging. in fig. 6 geological cross-section through cores b6 and s1 and the archaeological excavations of s. erasmo-s. chiara church and calderari area. for location see figure 2. the boiano basin since the times of ancient bovianum 25 the i century ad the urban and sub-urban areas of bovianum were completely reconstructed and the ancient colonia reached its maximum extension both towards the plain and the slope. more precisely, according to the reconstruction of the boiano roman colonia proposed by ceglia (2005b) and de benedittis et al. (2008), the city layout extended beyond the s1 core (as confirmed by archaeological remains in us 5), with the paved road discovered in the calderari area representing its center., also the low-lying sectors of the plain most likely underwent land reclamation in this period and were geometrically subdivided in parcels for agricultural and social purposes (centuratio), as demonstrated in choquer et al. (1987). the slope and piedmont areas were subjected to strong land-use changes, including terracing and building. the roman colonia layout seems to slowly decline starting from the iv century ad, when the roman empire fell. as a result of land degradations, together with an increase of rainfalls during the vi-ix centuries ad, the debris cone deposits of us 6 (b6 core) were laid down in the s. erasmo church area and buried the samniticroman walls. the coseismic effects related to the 853 ad earthquake may have influenced the debris production. during this period, as also highlighted by historical sources, in the plain sector located northward to the b6 core, also including the calderari area, marshy and fluvial-marshy deposits accumulated (us 7b of s1). this waterlogging event too, could have been caused by an increase of the relative subsidence rate of the plain, possibly linked to seismicity. consequently to the fluvialmarshy conditions that dominated the sector of the plain northward to the calderari stream, starting from this peri fig. 7 location and extension of the urban area of boiano, the waterlogged area and the ongoing debris production along the piedmont area during various periods, reconstructed by means of archaeostratigraphical data coming from cores s1 and b6 (yellow circles) and the examined archaeological excavations (for location see fig. 3). polygons in blue and orange indicate the presumed extension of the waterlogged area and the ongoing debris cone sedimentation, respectively. a) the boiano area before the iv-iii century b.c.; in yellow the aggradational piedmont zone. b) the boundaries of the samnitic bovianum and roman municipium during the time period iv-iii century b.c.-i century ad, marked by the defense walls (red lines). c) the layout hypothesis of the roman colonia (red grid) with its centre, the calderari archaeological area (b), during the i to iv century ad. d) the urban area of boiano in the time period v-ix century ad, partially affected by debris cone sedimentation and waterlogging. e) the hypothetical expansion upslope of the modern village of boiano (red polygon) during the xv to xvi centuries ad. f) the hypothetical extension of the modern village town of boiano (red polygone) during the last centuries. amato v. et al. 26 od and until the xix century ad the boiano settlement was particularly reduced in its urban extension and occupied only the piedmont area and the top of the civita palaeosurface. in the xv century ad the 1456 ad earthquake destroyed the s. chiara church and most of the village of boiano. starting from this date, the more marginal sectors of the plain including the s. chiara church were interested by debris cone deposition (us 8 in b6), while the more central northward-located sector was affected by fluvial-marshy sedimentation (us 9b in s1). the debris cone deposition and the waterlogging of the plain can be related most likely to the increase of rainfalls and the decrease of temperature that characterized the little ice age, which interested the mediterranean area between the xvi-xix centuries ad. these palaeoenvironmental changes could have been also influenced by seismic events (1456 ad and 1805 ad earthquakes), which may have caused coseismic subsidence. the tendency to waterlogging persisted until very recent times as highlights the several meters of man-made fills, which were placed in order to raise the floor during the rebuilding of the modern village of boiano. 6. summary and concluding remarks as the collected archaeo-stratigraphic data highlight, the area of boiano has been affected in historical times by important environmental changes evidenced by the repeated deposition along the piedmont area of scree/debris cone deposits that are laterally heteropic to fluvial marshy deposits of the plain sector in front of it. a synthetic view of main urban and environmental changes occurred within the boiano area in historical times is given in figure 7. this figure illustrates (sketches a-f) the location and extension of the urban area of boiano, the waterlogged area and the ongoing debris production along the piedmont area over various periods. conversely, the evolution of the plain sector inside and around the historical boiano appears to have been mainly controlled by repeated waterlogging, with exception to the roman colonia period (i-iv centuries ad), during which an important land reclamation was carried out (fig. 7c). the waterlogged areas reached major extensions before the iv-iii century b.c. (fig. 7a) and from the v century ad onwards (figs. 7d-f). with regards to the iv century b.c.-i century ad (fig. 7b), instead, waterlogging reached its major extent from the iii to i centuries b.c., when it affected the plain but did not interest directly the samnitic -roman settlement. waterlogging could have been possibly favored by coseismic subsidence induced by the earthquakes that occurred in the iii centuries b.c. -and in 853, 1456 and 1805 ad, respectively. in any case, the historical phases of waterlogging of the boiano area, in our opinion, can be mainly ascribed to the increase of precipitation during the cold dark age and the little ice age, but probably were also influenced by the socio-political crisis that followed the fall of the roman empire. consequently to these environmental changes, the samnitic-roman bovianum, the roman colonia and the middle age age settlement of boiano changed in extension and location. as evidenced by the archaeological finds within the core s1, the roman colonia (i-iv centuries ad) extended towards the plain sector, probably beyond the actually known boundaries, consequently to the land reclamation. subsequently, from the vi century ad to the xix century ad, the village of boiano progressively reduced the extension of its urban layout within the piedmont area and was partially relocated on top of the civita palaeosurface. these changes of the urban layout have been most likely caused both by the deterioration of the plain sector due to waterlogging and the above mentioned social and political crises. a new reoccupation phase of the plain started only in xx-xxi century, when the emplacement of several meters of man-made fills and extensive land reclamation allowed improving the drainage conditions. references allocca f., amato v., coppola d., giaccio b., ortolani f., pagliuca s. (2000) cyclical climatic-environmental variations during the holocene in campania ed apulia: geoarcheological and palaeoethnological evidences. memorie della società geologica italiana, 55, 345-352. amato v. (2006) la risposta di alcuni tipici sistemi morfodinamici della campania (italia meridionale) alle variazioni climatiche oloceniche. phd thesis, website www.fedoa.unina/636/, pp. 405. amato v., aucelli p.p.c., brancaccio l., cesarano m, rosskopf c.m. (2010a) inquadramento geologico-ambientale e geomorfologico. in: colombo c., guida pedologica ai suoli forestali del matese molisano. itinerari pedologici italiani/1, aracne ed., 61-97. amato v., bisogno g., cicala l., cinque a., romano p., ruello m. r., russo ermolli e. (2010b) palaeoenvironmental changes in the archaeological settlement of elea-velia: climatic and/or human impact signatures? in: senatore m. r., ciarallo a., scienze naturali ed archeologia, aracne ed., 13-17. amato v., aucelli p. p. c., cesarano m., pappone g., rosskopf c. m. russo ermolli e. (2011) the sessano intramontane basin: new multi-proxy data for the quaternary evolution of the molise sector of the central-southern apennines (italy). geomorphology, 128, 15-31, doi:10.1016/j.geomorph.2010. 12.019. amato v., aucelli p.p.c., russo ermolli e., rosskopf c.m., cesarano m., pappone g. (2012) quaternary morpho-evolution, tectonic and environmental changes in the boiano intermontane basin (central-southern italy). rend online società geologica italiana, 21, 1225-1227. amato v., aucelli p.p.c., ciampo g., cinque a., di donato v., pappone g., petrosino p., romano p., rosskopf c.m., russo ermolli e. (2013) relative sea level changes and palaeogeographical evolution of the southern sele plain (italy) during the holocene. quaternary international, 288, 112-128, doi:10.1016/j.quaint.2012.02.003. aucelli p.p.c., rosskopf c.m. (2000) last century valley floor modifications of the trigno river (s. italy): a preliminary report. geografia fisica e dinamica quaternaria, 23 (2), 105-115. aucelli p.p.c., robustelli g., rosskopf c.m., scarciglia f., di paola g., lucà f. (2010) geomorphologithe boiano basin since the times of ancient bovianum 27 cal map of the area between frosolone and trivento (molise, italy). journal of map, 423-434, doi: 10.4113/jom.2010.1039. aucelli p.p.c., amato v., cesarano m., pappone g., rosskopf c.m. russo ermolli e., scarciglia f. (2011) new morphostratigraphic and chronological constraints for the quaternary palaosurfaces of the molise apennines (southern italy). geologica carpathica, 62, 1, 17-26, doi:10.2478/v10096-0110002-2. barker g., webley j.l., webley d. (1978) classical landscape in molise. papers of the british school at rome, 46, 35-51. barker g, hunt c. (2003) the role of climate and human settlement in the evolution of the biferno valley (molise, central-southern italy). in albore livadie c., ortolani f., climatic-environmental variations and impact on man in the circummediterranean area. edipuglia ed., 183-191. baroni c., orombelli g. (1996) the alpine iceman and holocene climatic change. quaternary research, 46, 78-83. berglund b.e. (2003) human impact and climate changes: synchronous events and a causal link? quaternary international, 105, 7-12, doi: 10.1016/s10406182(02)00144-1. berglund b.e., birks h.j.b., ralska-jasiewiczowa m., wright h.e. (1996) palaeoecological events during the last 15000 years. regional syntheses of palaeoecological studies of lakes and mires in europe. wiley & son, chichester, pp. 764. bintliff j.l. (1982) palaeoclimatic modelling of environmental changes in the east mediterranean region since the last glaciation. in: bintliff j.l. and van zeist w., palaeoclimates, palaeoenvironments and human communities in the eastern mediterranean region in later prehistory. british archaeological reports, international series 133, oxford, 485-527. bond g., kromer b., beer j., muscheler r., evans m., showers w., hoffmann s., lotti-bond r., hajdas i., bonani g. (2001) persistent solar influence on north atlantic climate during the holocene. science, 294, 2130-2136, doi: 10.1126/science.1065680. borsato a., cucchi f., frisia s., miorandi r., paladini m., piccini l., potleca m., sauro u., spötl c., tuccimei p., villa i.m., zini l. (2003) ricostruzione climatica degli ultimi 17.000 anni da una stalagmite della grotta savi (trieste, italia). studi trent. sci. nat., acta geol., 80, 111-125. brancaccio l., cinque a., sgrosso i. (1979) forma e genesi di alcuni versanti di faglia in rocce carbonatiche: il riscontro naturale di un modello teorico. rendiconti dell’accademia di scienze fisiche e matematiche della società nazionale di scienze, lettere ed arti in napoli, 4, 46, pp. 21. brancaccio l., di crescenzo g., rosskopf c.m., santangelo n., scarciglia f. (2000) carta geologica dei depositi quaternari e carta geomorfologica dell’alta valle del fiume volturno (molise, italia meridionale). note illustrative. il quaternario, italian journal of quaternary science 13 (1/2), 81-94. buonocore m. (1992) una nuova testimonianza del rector provinciae autonius iustinianus e il macellum di saepinum. athenaeum, 80, 484-486. camodeca g. (1971) fabius maximus e la creazione della provincia del samnium. atti accademia pontaniana, 82, 249-264. capini s. (1980) la necropoli di campochiaro. sannio, 1980, 108-112. ceglia v. (2005a) san massimo, il sepolcreto in località noce di massaro, in de benedittis g., prima dei sanniti? la piana di bojano dall’età del ferro alle guerre sannitiche attraverso i materiali archeologici. campobasso, 2005, 97-100. ceglia v. (2005b) boiano (cb). il lastricato stradale. www.fastionline.org/docs/2005-32.pdf. chouquer g., clavel leveque m., favory f., vallat p.j. (1987) structures agraires en italie centromeridionale. cadastres et paysage ruraux, collection de l’ecole francaise de rome, pp. 432. coltorti m., ferand g., marzoli a., peretto c., ton that t., voinchet p., bohain j.j., minelli a., thun hohenstein u. (2005) new 40ar/39ar stratigraphic and palaeoclimatic data on the isernia la pineta lower palaeolithic site, molise, italy. quaternary international, 131, 11-22, doi:10.1016/j.quaint.2004.07.004. corrado s., di bucci d., naso g., butler r.w.h. (1997) thrusting and strike-slip tectonics in the alto molise region (italy): implications for the neogenequaternary evolution of the central apennine orogenic system. journal of the geological society of london, 154, 679-688. corrado s., di bucci d., naso g., valensise g. (2000) the role of pre-existing structures in quaternary extensional tectonics of the southern apennines, italy: the boiano basin case history. journal of the czech geological society, 45 (3/4), 217-231. cpti (2004) catalogo parametrico dei terremoti italiani, versione 2004 (cpti04). ingv, bologna. cremaschi m. (2000) manuale di geoarcheologia. laterza editore, pp. 368. cronin t.m., dwyer g.s., kamiya t., schwede s., willard d. a. (2003) medieval warm period, little ice age, and 20th century climate variability from chesapeake bay. global and planetary change, 36 (1-2), 17-29, doi.org/10.1016/s0921-8181(02)00161-3. daniels j.m. (2003) floodplain aggradation and pedogenesis in a semiarid environment. geomorphology, 56, 225-242, http://dx.doi.org 10.1016/s0169555x(03)00153-3. de benedittis g. (1977) bovianum ed il suo territorio. primi appunti di topografia antica. documenti di antichità italiche e romane, soprintendenza archeologica del molise, vii, pp.53. de benedittis g. (1995) repertorio delle iscrizioni romane del molise: bovianum. iresmo, campobasso, 12-16. de benedittis g. (2004) bovianum, aesernia e monte vairano: considerazioni sull’evoluzione dell’insediamento nel sannio pentro. in: aa.vv., samnium. settlement and cultural change. archeologia transatlantica xxii, brown university 2004, 23-33. de benedittis g. (2005) prima dei sanniti? la piana di bojano dall’età del ferro alle guerre sannitiche attraverso i materiali archeologici. iresmo, campobasso, 19-49. de benedittis g. (2012) ripensando ai terremoti del samnium: alcune note sull’area matesina tra iv sec. ad e iv sec. d.c. considerazioni di storia ed archeologia, 5, 76-82. amato v. et al. 28 de benedittis g., ceglia v., muccilli d., melfi c. (2008) dalla bojano sannitica al palazzo colagrosso, bojano 2008, 8-10. deino, a.l., orsi g., de vita s., piochi m. (2004) the age of the neapolitan yellow tuff caldera forming eruption (campi flegrei caldera italy) by 40ar/ 39ar dating method. journal of volcanology and geothermal research, 133, 157-170, http://dx.doi. org/10.1016/j.bbr.2011.03.031. de menocal p.b. (2001) cultural responses to climate change during the late holocene. science, 292, 667-673, doi:10.1126/science.1059827. di bucci d., corrado s., naso g. (2002) active faults at the boundary between central and southern apennines (isernia, italy). tectonophysics, 359, 4763, doi.org/10.1016/s0040-1951(02)00414-6. di bucci d., naso g., corrado s., villa i.m. (2005) growth, interaction and seismogenetic potential of coupled active normal faults (isernia basin, central-southern italy). terra nova 17, 44-55, doi: 10.1111/j.1365-3121.2004.00582.x. frezza m. (1579) de subfeudis baronum et investituris feudorum, venetiis, lib. i, 1579. galadini f., galli p. (2004) the 346 a.d. earthquake (central-southern italy): an archaeoseismological approach. annals of geophysics, 47, 885-905. galli p., galadini f. (2003) disruptive earthquakes revealed by faulted archaeological relics in samnium (molise, southern italy). geophysical research letters, 30, 1266, 70/1-4. galli p., galadini f., capini s. (2002) analisi archeosismologiche nel santuario di ercole di campochiaro (matese). evidenze di un terremoto distruttivo sconosciuto ed implicazioni sismotettoniche. il quaternario, italian journal of quaternary science, 15, 151-163. giraudi c. (1989) lake levels and climate for the last 30,000 years in the fucino area (abruzzo-central italy). a review. palaeogeography, palaeoclimatology, palaeoecology, 70, 249-260, doi.org/10.1016/ 0031-0182(89)90094-1. giraudi c. (1995) sedimenti eolici, variazioni climatiche ed influenza antropica: considerazioni su alcune piane intermontane dell’appennino abruzzese. il quaternario, italian journal of quaternary science, 8(1), 211-216. giraudi c. (2004) le oscillazioni di livello del lago di mezzano (valentano vt): variazioni climatiche ed interventi antropici. il quaternario, italian journal of quaternary science, 17, 221-230. giraudi c. (2005) the late holocene alluvial events in the central apennine (italy). the holocene, 15(5), 768-773, doi:10.1191/0959683605hl850rr. giraudi c., magny m., zanchetta g., drysdale r.n. (2011) the holocene climatic evolution of the mediterranean italy: a review of the geological continental data. the holocene, 21, 105-117, doi:10.1177/0959683610377531. giraudi c., orombelli g., ortolani f. (2007) variabilità naturale del clima nell’olocene ed in tempi storici: un approccio geologico. quaderni della società geologica italiana, pp. 24. hunt b.g. (2006) the medieval warm period, the little ice age and simulated climatic variability. climate dynamics, 27 (7-8), 677-694, doi:10.1007/s00382006-0153-5. la regina a. (1966) le iscrizioni osche di pietrabbondante e la questione di bovianum vetus. rheinische museum, cix, 1966, 260-286. lamb h.h. (1995) climate, history and the modern world. routledge 2a edition, london, pp. 443. magny m., vanniére b., calo c., millet l., leroux a., peyron o., zanchetta g., la mantia t., tinner w. (2011) holocene hydrological changes in southwestern mediterranean as recorded by lake-level fluctuations at lago preola, a coastal lake in southern sicily, italy. quaternary science reviews, 30, 2459-2475, doi:10.1016/j.quascirev.2011.05.018. magny m., begeot c., guiot j., peyron o. (2012) contrasting patterns of hydrological changes in europe in response to holocene climate cooling phases. quaternary science review, 22, 15891596, doi:10.1002/jqs.1543. mann m. (2003) little ice age. in mac cracken m. m. c. and perry j. s., encyclopedia of global environmental change, volume 1, the earth system: physical and chemical dimensions of global environmental change. john wiley & sons, 297-311. mayewski p.a., rohling e.e., stager j.c., karlefin w, maasch k.a, meeker l.d., meyerson e.a., gasse f., van kreveld s., holmgren k., lee-thorp j., rosqvist g., rack f., staubwasser m., schneider r.r., steig e.j. (2004) holocene climate variability. quaternary research, 62, 243-255, doi.org/ 10.1016/j.yqres.2004.07.001. mcdermott f., mattey d.p., hawkesworth c. (2001) centennial-scale holocene climate variability revealed by a high-resolution speleothem ð18o record from sw ireland. science, 294, 1328-1331. messerli b., grosjean m., hofer t., nunez l., pfister c. (2000) from nature-dominated to humandominated environmental changes. quaternary science reviews, 19, 459-479, doi:http://dx.doi.org/ 10.1016/s0277-3791(99)00075-x. muccilli o. (1985) presenza monastica nel territorio bojanese. note preliminari, conoscenze, 2, 1-25. orain r., lebreton v., russo ermolli e., aucelli p.p.c., amato v. (2012) végétation et climat au pléistocène moyen en italie méridionale (bassin de boiano, molise). quaternaire, 23, 35-46. orombelli g., ravazzi c. (1996) the late glacial and early holocene: chronology and paleoclimate. il quaternario, italian journal of quaternary science, 9(2), 439-444. ortolani f., pagliuca s. (1994) variazioni climatiche e crisi dell’ ambiente antropizzato. il quaternario, italian journal of quaternary science, 7(1), 351-356. ortolani f., pagliuca s. (2003) cyclical climaticenvironmental changes in the mediterranean area (2500 bppresent day). pages, 11(1), 15-17. pappone g., alberico i., amato v., aucelli p.p.c., di paola g. (2011) recent evolution and the present-day condition of the campanian coastal plains (southern italy): the case history of the sele river coastal plain. wit transactions on ecology and the environment, 149, 15-27, doi:10.2495/ cp110021. pappone g., aucelli p.p.c., cesarano m., putignano m. l., ruberti d. (2012) note illustrative della carta geologica d’italia alla scala 1:50.000, foglio 405 the boiano basin since the times of ancient bovianum 29 "campobasso". i.s.p.r.a., servizio geologico d’italia, pp. 160. patacca e., scandone p. (2007) geology of the southern apennines. bollettino società geologica italiana, special issue 7, 75-120. pescatore t.s., cinque a., senatore m.r., rosskopf c. (2004) historical-geological events and their impact on man. field trip guide book p14, 32nd international geological congress, firenze 2004, pp. 44. piva a., asioli a., trincardi f., schneider r., vigliotti l. (2008) late holocene climate variability in the adriatic sea (central mediterranean). the holocene, 18, 1, 153-167, doi:10.1177/0959683607085606. pope k.o., van andel t.h. (1984) late quaternary alluviation and soil formation in the southern argolid: its history, causes, and archaeological implications. journal of archaeological science, 11, 281306, doi:10.1016/0305-4403(84)90012-8. pope r.j.j., wilkinson k.n., millington a.c. (2003) human and climatic impact on late quaternary deposition in the sparta basin piedmont: evidence from alluvial fan systems. geoarchaeology, 18(7), 685-724, doi:10.1002/gea.10089. roberts n., jones m.d., benkaddur a., eastwood w.j., filippi m.l., frogley m.r., lamb h.f., leng m., reed j.m., stein m., stevens l., valero-garcés b., zanchetta g. (2008) stable isotope records of late quaternary climate and hydrology from mediterranean lakes: the isomed sysnthesis. quaternary science reviews, 27, 2426-2441, doi: 10.1016/j.quascirev.2008.09.005. rosskopf c.m., de benedittis g., mauriello m. (2006) indagini geoarcheologiche integrate nel molise centrale (italia meridionale): il ponte romano di tufara. il quaternario, italian journal of quaternary science, 19 (2), 239-250. rosskopf c.m., scorpio v. (2013) geomorphologic map of the biferno river valley floor system (molise, southern italy). journal of maps, doi:10.1080/ 17530350.2012.755385. russi a. (1971) l’amministrazione del samnium nel iv e v secolo d.c. iii miscellanea greca e romana, roma 1971, 307-346. russo f., terribile f. (1995) osservazioni geomorfologiche, stratigrafiche e pedologiche sul quaternario del bacino di boiano (campobasso). il quaternario, italian journal of quaternary science, 8 (1), 239-254. soil survey staff (2010) keys to soil taxonomy. 11th edition. u.s. department of agriculture, natural resources conservation service. http://soils.usda.gov/ technical/classification/tax_keys/. soricelli g. (2009) la provincia del samnium e il terremoto del 346 d.c. interventi imperiali in campo economico e sociale da augusto al tardo antico. edipuglia, bari, pp. 58. tucker m.e. (2011) sedimentary rocks in the field: a practical guide, fourth ed. john wiley and sons, ltd, chichester, england, pp. 275. valensise g., pantosti d. (eds.) (2001) database of potential sources for earthquakes larger than m 5.5 in italy: annali di geofisica 44, suppl., with full database on cdrom (in part available also at www.ingv.it). vita-finzi g. (1969) the mediterranean valleys: geological changes in historical times. cambridge un. press, pp. 140. young a. (1972) slopes. oliver & boyd, edimburgh, pp. 288. wilkinson k.n., pope r.j.j. (2003) quaternary alluviation and archaeology in the evrotas valley, southern greece. in: howard a.j. & passmore d. (eds.), alluvial archaeology in north-west europe and the mediterranean, rotterdam, 187-199. zolitschka b., wulf s., negendank j.f.w (2000) circum-mediterranean lake records as archives of climatic and human history. quaternary international, 73/74, 1-5, doi:0.1016/j.bbr.2011.03.031. ms. received: december 2, 2012 final text received: february 18, 2013 << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /all /binding /left /calgrayprofile (gray gamma 2.2) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /warning /compatibilitylevel 1.4 /compressobjects /tags /compresspages true /convertimagestoindexed true /passthroughjpegimages true /createjobticket false /defaultrenderingintent /default /detectblends true /detectcurves 0.1000 /colorconversionstrategy /leavecolorunchanged /dothumbnails false /embedallfonts true /embedopentype false 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documenti pdf creati possono essere aperti con acrobat e adobe reader 5.0 e versioni successive.) /enu (use these settings to create adobe pdf documents suitable for reliable viewing and printing of business documents. created pdf documents can be opened with acrobat and adobe reader 5.0 and later.) >> >> setdistillerparams << /hwresolution [1200 1200] /pagesize [396.850 566.929] >> setpagedevice amq29(1) 7 gori et al 91-106.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 29 (1), 2016, 91-105 active transpressive surface faulting in north-eastern calabria, southern italy: early results of geomorphological, stratigraphic and paleoseismological analyses stefano gori1, emanuela falcucci1, giandomenico fubelli2, francesco muto3, francesco dramis4 1 istituto nazionale di geofisica e vulcanologia, rome, italy 2 università degli studi di torino, italy 3 università della calabria, italy 4 università degli studi roma tre, rome italy corresponding author: s. gori <stefano.gori@ingv.it> abstract: we here first described field evidence of holocene transpressive faulting in north-eastern calabria, about 15 km east of rossano, in the area of mirto. there, we analysed a stratigraphic sequence exposed along a wnw-ese trending, 4-km-long scarp, anomalous in the local geomorphic context. the sequence was made of marine deltaic sediments with embedded colluvial deposits, daylighted by an excavation for a building. the excavation occurred on top of a fluvial terrace at ~15 m a.s.l., that was embedded in a mis 5a marine terrace. micropaleothological analysis and 14c radiometric dating defined an early(-middle) pleistocene age for the marine sequence and a holocene age for the overlain colluvial deposits. the whole sequence was back-tilted, warped and offset along shear planes showing an evident reverse sense of motion. the uphill sense of displacement, the local geomorphic setting and the available literature allowed to exclude any other cause (e.g. deep-seated or shallow landsliding, salt diapirism) than tectonics for the observed deformations. by considering the current knowledge about the structural and active tectonic framework of the northern calabrian arc, the observed reverse fault planes can be the surface expression of either local active compressional deformations (i.e. restraining bend) along the rossano-cirò marina strike slip shear zone, being part of the regional, left-later strike-slip pollino line, or an inland splay of the active transpressional tectonic structures offshore of the sibari plain and the rossano area. even if at an early stage, our observations can represent a new piece in the active tectonics puzzle of the boundary region between the calabrian arc and the southern apennines. they also provide new hints for seismotectonic evaluations, taking into thorough consideration that the ob-served tectonic features occur in the epicentral area of the 1836 (mw 6.2) earthquake, the causative fault of which is still debated. ultimately, the present study raises new questions about reverse surface faulting hazard assessment for this region. keywords: holocene transpression; surface faulting; paleoseismology; north-eastern calabrian arc; southern italy 1. introduction the calabrian arc is a fragment of european continental crust that drifted towards the southeast since the late oligocene-miocene (e.g. gueguen et al., 1998) and interposed between the southern apennines and the maghrebian chains. it represents an accretionary wedge (amodio morelli et al., 1976; dewey et al., 1989; doglioni, 1991; kastens et al., 1988; malinverno & ryan, 1986; ogniben, 1973; patacca & scandone, 1989; royden et al., 1987) formed by alpine units consisting of a series of mesozoic ophiolite-bearing tectonic units and overlain by crystalline-metamorphic basement nappes (calabride complex; ogniben, 1969). the alpine nappes outcropping in the coastal chain and in the sila massif, during oligocene-early miocene, overthrusted on the mesozoic carbonate terranes belonging to the mesozoic apennine domain. in the middle miocenemiddle pleistocene time, the calabrian arc was affected by a regional nw-se left-lateral transcurrent fault system which dissected the orogenic belt generating transverse and longitudinal structural highs and basins (ghisetti & vezzani, 1981; dewey et al., 1989; turco et al., 1990; van dijk et al., 2000; tansi et al., 2007). the lateral juxtaposition of these different tectonic blocks consists in two complex region-al shear zones, perpendicular to the axis of the arc. these zones seem to reflect two lithospheric tear faults that permitted the south-eastward retreat of the ionian slab subducting towards the nw (e.g. rosenbaum et al., 2008), and onto which the calabrian arc “floats”. the tectonic boundary between the calabrian arc and the southern apennine is commonly referred to as “pollino line” (hereafter pl) (fig. 1). it consists in a nw-se trending tectonic lineament at the transition between the meso-cenozoic carbonate sequences of the southern apennines-lucanian boundary and the metamorphic and igneous basement terrains of the calabrian block. from a structural point of view, left-lateral strike slip sense of motion is commonly attributed to the pl (e.g. tansi et al., 2007) (fig. 1, inset), although its kinematic history, in the framework of the subduction system, is still a matter of discussion. from a seismological point of view, a change in the fast directions of the seismic anisotropy, that shifts from nnw-sse trending, in the southern apennines, to nne-ssw trending, in northern calabria (baccheschi et al., 2008 and references therein) occurs across the pl. moreover, seismic tomography analysis shows that the line corresponds to a 92 gori s. et al. fig. 1 tectonic-structural setting of the calabrian arc (modified from tansi et al., 2007). a detail of the north-eastern portion of the arc (after tansi et al., 2007), inset. the area under investigation, red rectangle. fig. 2 a) digital terrain model onto which the epicentres of the major historical earthquakes that struck the calabrian arc (rovida et al., 2011) are indicated (coloured rectangles); b) intensities distribution (mcs scale) related to the 1836 rossano earthquake. lithospheric discontinuity (totaro et al., 2014; chiarabba et al., 2016). these seismological observations point out to structural-kinematic “separation” of the southern apennines from the calabrian arc along such a crustalscale discontinuity. this boundary zone between the calabrian and the apennines blocks appears quite complex also in a quaternary and active tectonics perspective. the southern tip of the apennines was affected during the quaternary by prevailing extensional deformation, presently active. this is witnessed by the nw-se trending pollino range -castrovillari active normal fault (cinti et al., 2002), even if structural evidence of strike-slip movements has been detected along this structure (e.g. monaco, 1993). comparably, extension seems to affect the northern part of the sila massif, at the northern reach of the calabrian block. normal faulting has been indeed pro-posed along the wnw-ese trending rossano fault (galli et al., 2009), that bounds the sila massif to the northnortheast. nevertheless, evidence of wnw-ese and nw-se trending strike slip movements in the early quaternary has been found along the northern flank of the sila massif, with local transpressive component of motion (and, subordinately, transtensional deformations) (folino gallo, 2010). furthermore, a complex zone of transpressive deformation, about nw-se trending (van dijk et al., 2000; muto et al., 2014) is seen in the coastal and off-shore sector of the sibari plain, and defined as active (ferranti et al., 2009; 2014). in such a tangled region of structural-tectonic transition, the present study provides new field data collected in north-eastern calabria, in the area of rossano. the paper documents and interprets stratigraphic and structural data of a single exceptional outcrop of quaternary deposits exposed during building construction near the coastal sector of the mirto town. in particular, we examine the stratigraphic sequence through sedimentological and paleontological analyses. these data, together with radiometric age determinations (14c method) and with the analysis of the local geomorphic framework, allow to obtain paleo-environmental and chronological information for the examined succession. the data obtained constitute the basis for a comprehensive interpretation of the deformations that the stratigraphic sequence underwent, as for the causative factors, kinematics and chronology. after providing with a general overview of the geological characteristics of the northern calabrian arc and of the area under investigation, the results of our analyses are shown in detail. we took particular care in describing the deformations affecting the stratigraphic sequence. in the discussion, we examine the gathered data with the aim of interpreting them in the framework of the regional tectonic setting. lastly, we unfold the implications that our study, although at an early stage, has in terms of active tectonics and related hazards assessment. 2. geological and seismotectonic background the calabrian arc constitutes an accretionary wedge growing up above a narrow and steeply dipping slab that subducts towards the northwest, resulting from the fragmentation of a wider slab related to the western mediterranean subduction zone (faccenna et al., 2004). the related wadati-benioff zone is enlightened by tomographic studies (e.g. piromallo & morelli, 2003) and by the hypocentres of hundreds of earthquakes (vannucci et al., 2004; chiarabba et al., 2008). since the early miocene, overthrusting of palaeozoic basement nappes on meso-cenozoic basinal sequences occurred through compressive structures that progressively migrated east-and south-eastwards (e.g. parotto & praturlon, 2004), accompanying the progressive opening of the tyrrhenian sea (e.g. faccenna et al., 2001). minelli & faccena (2010) investigated the present structural setting of the calabrian accretionary prism by means of geological investigations and interpreting a large number of industrial seismic reflection profiles. the authors defined that the growth of the belt took place through forward propagation stages of frontal accretion and out-of-sequence internal thrusting of pliocene age (or later). during the eastward and south-eastward migration of the compressive front, the inner portions of the arc began to be affected by extensional deformation (e.g. ghisetti, 1979; 1980; tortorici et al., 1995; monaco et al., 1996; mattei et al., 2002; muto & perri, 2002; rossetti et al., 2004; cifelli et al. 2007; critelli et al., 2013), which is currently active (e.g. d’agostino et al., 2011). this process determined the formation of arc-parallel, n -s and ne-sw trending normal-to-transtensive fault systems and extensional detachments, which dissected the structural edifice inherited by the compressive tectonic phase (monaco et al., 1996). the activity of the extensional structures determined the formation of n-s and ne-sw elongated tectonic basins, such as the crati and mesima valleys and the sant’eufemia, gioia tauro and messina strait basins, that hosted marine and continental sedimentary sequences during the pliocenequaternary. most of the n-s and ne-sw trending extensional faults are interrupted against others almost perpendicularly oriented, i.e. e-w and wnw-ese, as the rossano, catanzaro strait and nicotera-coccorino fault systems (e.g. galadini et al., 2001; tortorici et al. 2003; guarnieri, 2006; tansi et al., 2007; tripodi et al., 2013; brutto et al., 2016). these structures may have played and may still play the role of tear faults that absorb differential motions within the calabrian accretionary prism, and/or of transfer faults that kinematically link different, en-echelon arranged normal fault systems. at the early-middle pleistocene transition, the whole calabrian arc began to undergo uplift (e.g. westaway, 1993; bordoni & valensise, 1998; monaco et al., 1998). this is testified by the presence of flights of marine terraces along both the tyrrhenian and the ionian flanks of the arc (e.g. cosentino & gliozzi, 1988; dumas et al., 1988; miyauchi et al., 1994; carobene, 2003; cucci, 2004; cucci & tertulliani, 2006; robustelli et al., 2009). the uppermost terrace orders occur at more than 1000 m above the present sea level. uplift rate of 0.6-1.3 mm/ yr, increasing southward, has been defined (e.g. molin et al., 2002; dumas & raffy, 2004). from a seismotectonic viewpoint, the calabria region has been the focus of some of the most destructive active transpressive surface faulting in north-eastern calabria, southern italy: ... 93 earthquakes that struck the italian territory over the past millennium, characterised by magnitudes of up to about 7. these include the 1638 and 1783 seismic sequences the two main shocks of the latter had mw 7 and 6.9, respectively and the 1832 (mw=6.5), 1905 (mw=6.7) and 1908 (mw=7.1) earthquakes (rovida et al., 2011) (fig. 2a). more in general, at least 19 earthquakes with m>6 occurred since the 91 b.c. in this region. the sources of these events are commonly attributed to the activation of normal faults either westor east dipping, affecting the innermost sectors of the arc (galli et al., 2009; diss working group, 2015). however, the causative structures of some of these earthquakes are still a matter of debate. one of these is the mw 6.2 event occurred in 1836, that is the strongest known earthquake of north-eastern calabria (fig. 2b). the earthquake determined severe damage to the villages of rossano, crosia, calopezzati and corigliano, which underwent 10, 9, 9 and 8 intensity degree (mcs scale), respectively. different hypotheses yet not conclusive on the causative fault of this event are illustrated in the following paragraph. 3. the rossano sector the area under investigation locates at the northeastern border of the sila massif, which is made of hercynian crystalline basement and a meso-cenozoic sedimentary cover (ogniben, 1973; amodio morelli et al., 1976) (fig. 3), which is made up of palaeozoic basement and its mesozoic sedimentary cover (critelli et al., 2013), unconformably overlain by alluvial to turbiditic deposits of oligocene to miocene age (paludi fm). upsection, serravallian-tortonian basal transgressive sequence consists of alluvial and fan-delta conglomerates, passing upward to cyclic alternations of shale, marls with interbedded arenite turbidites to the biosiliceous clay. then, since late miocene two subsequent depositional cycles were unconformably deposited. these latter are unconformably overlain by two subsequent 94 fig. 3 geological and structural framework of the northern sila massif and of the rossano area (modified from folino gallo, 2010). the area under investigation, red rectangle. gori s. et al. depositional cycles. the lowermost cycle, constituted by two sedimentary sub-cycles, is known as “complesso postorogenico” (ogniben, 1973). the lower sub-cycle is made up of a sandy -conglomeratic formation underlying evaporitic deposits related to the messinian; clay and marly-clay units underlay calcareous and evaporitic limestones (amodio morelli et al., 1976, and references therein), that represent the closure of the sequence. the upper sub-cycle is represented by turbiditic clays and gypsum, that laterally pass to calcareous sands (amodio morelli et al.,1976, and references therein; barone et al., 2008; zecchin et al., 2013). the “argille varicolori” formation unconformably overlays both the subcycles (ogniben, 1962). the “argille varicolori” formation has been involved in a backthrust with an oligocene-miocene succession starting from the upper tortonian in the northern ionian basin (roda, 1967; muto et al., 2014; muto et al., 2015) and during the langhian in the southern ionian basin (cavazza & barone, 2010; tripodi et al., 2013).the second cycle is known as “ciclo suprapliocenico-pleistocenico” (vezzani, 1968) and it is made up of sandy, gravelly and clayey sediments (vezzani, 1968; ogniben, 1973; critelli, 1990; zecchin et al., 2012; 2015). since the middle pleistocene, the interaction between regional uplift, local tectonics, climate and glacioeustatic changes allowed the formation of flights of terraces. four order of terraces have been recognized by carobene (2003) and five by robustelli et al. (2009) along the coastal portion of the trionto river, while cucci & cinti (1998) distinguished seven order of terraces north of the crati river. ferranti et al. (2009) identified eleven orders of terraces in the area comprised between the northeastern border of the sila massif, the crati plain and the coriglianeto river. olivetti et al. (2012) pointed out uplift of the whole sila massif by means of morphometric analysis and incision rate estimation on fluvial systems crossing the massif. different rates of uplift have been estimated: 0.460.69 mm/yr east of the trionto river (carobene, 2003), and 0.64-0.85 mm/yr north of the crati river (cucci & cinti, 1998). corbi et al. (2009) proposed that the uplift rate for rossano-corigliano sector increased through time, 0.52-0.57 mm/yr, based on the elevation of the “first order” of terraces (i.e. the earliest one, related to the mis 9 or 11), to 0.79-0.88 mm/yr, related to the “fifth order” of terraces (i.e. the latest order, related to the mis 5a). the structural setting of the area was the object of several studies in the past. the main tectonic feature of the area is referred to as the rossano fault, as segment of the “cetraro-rossano line” in moretti & guerra, 1997, or “rossano fault” according corbi et al., 2009 and galli et al., 2009; milia et al., 2009. the tectonic structure experienced a complex kinematic history, characterised by normal-to-normal oblique and strike slip kinematics (moretti & guerra, 1997; corbi et al., 2009). van dijk et al. (2000) identified the nw-se oriented 95 fig. 4 a) google earth image of the area comprised between the trionto and the fiumarella rivers. trace of the scarp seen be-tween the cento fontane and marina di calopezzati localities, red line. b) digital terrain model (shaded relief) onto which the three most recent marine terrace of carobene (2003) are indicated active transpressive surface faulting in north-eastern calabria, southern italy: ... cently, galli et al. (2009) described evidence of extensional displacement of holocene slope deposits along the 12 km long rossano fault. conversely, evidence of early quaternary displacement along wnw-ese and nw-se strike slip tectonic structures has been identified, with mainly transpressive components of motion (folino gallo, 2010) (fig. 3). the “corigliano-rossano line” was hypothesised by moretti (2000) to be the causative fault of the 1836 earthquake. the same hypothesis has been proposed by galli et al. (2009) for the rossano normal fault. the authors also suggested the structure as the source of a middle age event, that heavily affected rossano in ~951 ad. however, no conclusive data have been provided thus far. moreover, recent investigation made by ferranti et al. (2014) add information about the recent growth of the amendolara ridge, an anticline located offshore of the sibari coastal plain (fig. 3). the formarossano-san nicola fault zone, extended from the rossano site, to the north west, and san nicola dell’alto to the southeast. the structure is characterized by a sinistral transpressive kinematics along which basement and cover of the sila unit and miocene deposits have been extruded and sheared. according the authors the e-w oriented rossano fault is depicted as a normal fault that interrupts toward the north the nw transpressive fault zone. moreover, this fault is interrupted to the west by the n-s fault system of the eastern crati basin (spina et al., 2011; tansi et al., 2007). as for the activity of this fault system, several minor normal-to-strike slip shear planes affected quaternary marine and continental sequences in the area of rossano (corbi et al., 2009). moretti (2000) hypothesised the late pleistocene-holocene activity of this tectonic structure, even if the author did not provide clear geological evidence supporting this statement. more re 96 fig. 5 google earth image showing a frontal view of the scarp (indicated by red triangles); pictures of the scarp in insets, indicated by white and black triangles. gori s. et al. tion of the anticline is related to a transpressive tectonic structure defined as a potential source of m ~6 seismic events. nevertheless, the authors did not explicitly make hypotheses about the involvement of the amendolara ridge structure in the 1836 earthquake, whose focus remains currently located inland. 4. field data geomorphic field investigations in the coastal area just se of the trionto river mouth allowed the identification of a 6 meters-high scarp, trending about nw-se (figs. 4a, b). although seldom reshaped by anthropic activities, the scarp is roughly detectable from the cento fontane to the marina di calopezzati localities, for a total length of about 4 km (fig. 5), and it tapers down to about 3 m-high moving eastward. noteworthy, in the area of cento fontane, water emission occurred along the scarp (de rosis, 1838). some hundreds of metres northwest of marina di calopezzati, the scarp merges with the toe of a terrace occurring at ~30 m a.s.l., that we can refer to terrace t4 of carobene (2003), attributed by the author to mis 5c5a. this attribution is supported by the presence of a further terrace west of the trionto river, attributed to mis 5a by robustelli et al. (2009), and that occurs at comparable elevation. the terrace is incised towards the southeast by the fiumarella river valley. a narrow almost flat surface is seen along the left flank of this valley (fig. 6a). this landform gently dips towards the north i.e. seawards and occurs at about 15 m over the present coastline. the land surface displays a slightly convex upward longitudinal profile. on top of the terrace, we found an excavation for a building whose walls were up to 2.5 m high and oriented ne-sw, that is roughly parallel to the landsurface elongation (fig. 6b). the excavation exposed a prevailing sandy-clayey sedimentary sequence, that we describe in detail in the following. 4.1. morpho-stratigraphic analyses the succession exposed by the excavation was made of layered yellow-orange fine-to-coarse sands, clayey sands and clay, with rare gravel levels interbedded (fig. 6a). the layers generally displayed a fining upward grading. the gravels were made of rounded and flattened pebbles (whose long axis paralleled the bedding) of limestone, granite and metamorphic rocks, pertaining to the pre-quaternary bedrock sequences that crop out along the inner sectors of the fiumarella catchment. we sampled the clay and clayey-sandy portions of the sequence for micropaleontological analyses (fig. 6b). they provided marine foraminifera of both planktonic and benthic species. the planktonic foraminifera were: globorotalia inflata, neogloboquadrina acostaensis sx, globorotalia crassaformis, globorotalia scitula, globigerinoides obliquus, globigerina bulloides, orbulina universa. the benthic foraminifera were: ammonia tepida, ammonia parkinsoniana, elphidium crispum, elphidium advena, cassidulina carinata, cassidulina crassa, bu limina basispinosa, bulimina elegans marginata, bulimina elongata, cibicidoides kullenbergi, hyalinea baltica, melonis barleeanum, valvulineria bradyana. in terms of chronology, globorotalia inflata appeared at the base of mpl6 biozone, i.e. between the gelasian and calabrian stages. hyalinea baltica appeared at the early emilian substage, i.e. in the middle early pleistocene. bulimina basispinosa disappeared at the end of the emilian substage. such a faunal association and the described sedimentological characteristics indicate that the sequence was deposited during or after the early pleistocene, in a marine environment likely a paleodelta relative to infrato circa-littoral zone. this chronological attribution is corroborated by the fact that towards the southwest, the analysed sequence laterally passed to a clay succession (about 3 m exposed thickness). the geomorphic and stratigraphic framework of the area permits to relate the clay to the marine sequence of the “ciclo suprapliocenico-pleistocenico” of vezzani (1968), described in this area by bigazzi & carobene (2004). the mentioned authors attributed the deposits to the middle pleistocene, based on the presence of an interbedded tephra layer related to this period. the excavation walls also showed colluvial deposit (about 2 m exposed thickness) embedded within and partly overlying the marine sequence through an evident surface of linear erosional (figs. 7a, b) i.e. a channel trending wnw-ese, i.e. roughly perpendicular to the excavation walls. the colluvial sediments were made of sparse rounded pebbles (mainly sandstone, limestone, granite and gneiss) in a brownish-reddish silty-clayey matrix. they were probably fed by a small stream incision, still partly visible along the flank of the fiumarella valley (fig. 6a). the incision sourced from the top of the above mentioned marine terrace at 30 m a.s.l., cutting through the described marine sequence. a sample of organic rich matter collected from the uppermost portion of the colluvial sediment (fig. 7b) gave an age of 8397±47 ka b.p. (radiocarbon age)/7553-7351 b.c. (calibrated, 2σ, with code calib5) (radiocarbon dating performed by circe laboratory, dept. of environmental sciences, caserta, italy; sample dsh612). as the radiocarbon date refers to organic matter contained within the colluvial body, it implies that the obtained age relates to the parent material, the colluvial deposition being inherently subsequent. 4.2. evidence of deformation the whole sedimentary sequence displayed evidence of deformation, which can be distinguished into two different types. first, on a broad scale, the paleodeltaic sequence displayed a 20° to 40° counterslope dipping attitude (i.e. westand south-westward). such geometrical feature is inconsistent with the depositional and paleo-environmental features of the deposits (north to north-eastward), that is, a paleo-delta, which is supposed to have had a ne-ward progradation. such a high angle dipping attitude is geometrically inconsistent even considering the possibility that the observed section affected a lateral portion of the delta, where the layers may have an apparent counterslope dipping but with a much lower degree with respect to that here observed. 97 active transpressive surface faulting in north-eastern calabria, southern italy: ... 5. discussion the sedimentological characteristics, the micropaleontological content and the morphostratigraphic framework (fig. 9) of the analysed marine sequence define a deposition in an infrato circa-littoral paleodeltaic environment, that is a hundred metres below the sea level (or even more) (carobene, 2003). because the investigated early-middle pleistocene deltaic succession has strata steeply dipping to s-sw, i.e. opposite to the expected progradation of the sedimentary body, and is presently located at about 15 m a.s.l., it must have undergone a significant tilting and uplift after the deposition. from the tectonic point of view, tilting and uplift likely stem from superimposition of a major regional component (due to deep-seated thrusts and/or crustalscale folding), that involves large part of this sector of the calabrian arc, and local components likely related to the transpressive observed faults. after landward tilting, the sequence has been cut by inverse fault planes. as for the origin of the observed displacements, the counterslope tilting of the sedimentary sequence and the upslope/top-to-sw sense of motion of the shear planes allow to exclude any possible gravitational cause (i.e. landsliding) of the deformation. salt tectonics can be ruled out as well. indeed, while second, evidence of localised deformation was represented by a series of shear planes, trending (i.e. about n130° to n150°) and dipping towards the northeast (fig. 8a). these faults splay showed a top-to-sw (then landward/uphill) reverse sense of motion, and local curviplanar geometry, determining also folding of the strata. in the core of the observed fold, the deformation was mainly accommodated by the shear planes and bending became less evident. the bent geometry of the lowermost marine layers, marked by the pebbles attitude, also suggested the presence of a deeper reverse shear plane not reached by the excavation (fig. 7b). the colluvial sediment, moreover, was displaced by some minor nearly vertical, about nwse striking (~n130°-150°) conjugate fault planes that showed faint horizontal slickenlines (figs. 7b and 8b), and which seemed to join the uppermost portions of the above described inverse faults. coupled with the reverse shear planes, these structural features suggest that, overall, the observed deformation is to be referred to a transpressive shear zone. this might be also responsible for the gentle upward convex attitude of the terrace. the paleontological determinations and the 14c age obtained by dating the colluvial deposits yields that the fault planes were active over the quaternary, even during the holocene. 98 fig. 6 a) google earth image on which the main geomorphic features of the area under investigation are indicated; mis 5a marine terrace, white triangles; terrace affected by the excavation, yellow triangles; trace of the described scarp (see text), red line; stream incision that fed the colluvial deposits (see text), light-blue arrow. b) picture of the building under construction. gori s. et al. evidence of this phenomenon was identified in other sectors of the outer margin of the calabrian arc (e.g. del ben et al., 2008; minelli & faccenna, 2010), no signature of salt diapirism has been found in this area on the many seismic lines that cross the coriglianorossano onshore and offshore sectors (e.g. van dijk et al., 2000; del ben et al., 2008; ferranti et al., 2014). therefore, a tectonic cause has to be invoked. the radiometric age constraint indicates activation of the reverse fault planes over the past few millennia, resulting in surface faulting. the activation in recent times of the structural features is also corroborated by the morpho-stratigraphic setting of the area: the displaced holocene colluvial deposits are embedded within a terrace that, in turn, is embedded within the mis 5a marine terrace. this fact suggests that the landsurface may be associated to a later isotopic stage, likely mis 3, aged at 60-30 ka. in this perspective, molin et al. (2002) formerly recognised just east of the trionto river a terrace order (name as t5) embedded within mis 5a terraces, at 15-8 m a.s.l., i.e. at the same elevation of the terrace that we are dealing with. moreover, mis 3 terraces (specifically mis 3.3) have been identified by other authors in the area of capo vaticano (tortorici et al., 2003), along the central portion of the western calabrian arc. therefore, a mis 3-related age of the considered terrace is likely. as a result, the incision filled 99 fig. 7 a) picture of the excavation wall. b) stratigraphic scheme of the excavation wall. active transpressive surface faulting in north-eastern calabria, southern italy: ... lateral high angle faults. the presence of a major tectonic feature with prevailing strike slip sense of motion is also supported by low-to-moderate magnitude seismicity (m of up to 4.5-5), consistent with strike slip ruptures, clustered along the “ne-sila seismic zone” (presti et al., 2013). hence, the compressive deformation analysed in the present work may represent local reverse planes associated to a restraining bend. 3. the sole different view of the active tectonics of the area is that proposed by galli et al. (2009), who proposed the rossano fault as an extensional tectonic structure active during the holocene. as a result, a twofold reason makes us lean for the second hypothesis: firstly, the fact that the observed fault planes are aligned with the inland rossano-san nicola fault zone fault zone and, secondly, the distance between the investigated site and the transpressive structure in the near offshore sector of the sibari plain. within this light, the extensional faulting recognised by galli et al. (2009) along the rossano fault can be a local kinematic complexity or an extensional fault associated to the mainly nw-se strike slip regional shear zone. in seismotectonic perspective, our observations provide with insight on the geometry and kinematics of potential seismogenic structures of the area, comprising the causative fault of the 1836 seismic event. the intensity distribution of this large magnitude seismic event appears as rather incomplete, owing to the lack of any intensity datapoint in the ionian sea, evidently (fig. 10). despite such incompleteness, the maps of the highest intensity datapoints (galli et al., 2009; locati et al., 2011) suggest a local origin of the earthquake. in parby the colluvial deposits can be related to the fall of the sea level occurred during the last glacial maximum (mis 2), that is 25-15 ka; and this is concordant with the radiometric age obtained for the uppermost portion of the colluvial body, that postdates the end of mis 2. in terms of active tectonics, the present knowledge about the northern calabrian arc, earlier illustrated, allows making hypotheses on the plausible major structure associated to the observed reverse fault planes, illustrated in the following: 1. on the one hand, they may be the surface expression of the major transpressional shear zone, roughly wnw-ese trending, located in the offshore sector of the rossano area and of the sibari plain, identified by van dijk et al. (2000) and del ben et al. (2008) through the interpretation of reflection seismic lines. the evidence of middle-late pleistocene activity of the transpressional deformation responsible for the growth of the amendolara ridge, shown by ferranti et al. (2014), are indeed consistent with the observed reverse faults, that may represents landward splays of this transpressive shear zone. 2. on the other hand, the identified deformation is also consistent with the occurrence of quaternary strike slip movements, with local transtensional and transpressive kinematics, in the area comprised between rossano (east of the town) and cirò marina (corbi et al., 2009; folino gallo, 2010), referred to as rossanosan nicola fault zone by tansi et al., 2007, muto et al., 2014. the investigated structures are compatible with the offshore nw-se oriented major shear zone provided by ferranti et al. (2009, 2014) and can represent the onshore expression of transpressive left 100 fig. 8 a) detail of the deformation (bending, marked by the dashed blue line; offset, marked by the dashed yellow lines) that affect-ed the sedimentary sequence. b) detail of the sub-vertical shear planes (indicated by black and white triangles) that affected the collu-vial deposit (sub-horizontal slickenlines are indicated). gori s. et al. ticular, it would have been sourced from a roughly nwse to wnw-ese trending structure which, as mentioned above, galli et al. (2009) associated to an activation episode of the rossano normal fault (fig. 10 and inset). nonetheless, the transpressive faulting evidence we collected is compatible both in terms of orientation and of location with a main seismogenic fault located right in the epicentral area of the 1836 earthquake (fig. 10, inset). this is particularly evident in the cases of crosia and calopezzati. these villages are in fact the closest to the identified structures, and they did “suffer” the highest level of damage (10 and 9 intensity degree, mcs scale, respectively). such high degrees of damage were hypothesised by galli et al. (2009) to be caused by a possible eastward directivity of the coseismic rupture, located several kilometres to the west of these villages. instead, it may be more likely due to the activation of a closer fault, in this portion of the ionian coastal area. 6. conclusions we investigated a stratigraphic section exposed about 15 km east of rossano, in north eastern calabria (southern italy), on top of a terrace located at the southeastern tip of an anomalous scarp, a few km long, trending about wnw-ese and dipping nnw-wards. the section revealed that a marine paleo deltaic sequence, aged at the early(-middle) pleistocene by means of 101 fig. 9 schematic reconstruction of the morpho-stratigraphic and structural setting of the examined area. fig. 10 intensities distribution of the 1836 rossano earthquake (rovida et al., 2011); trace of the rossano extensional fault according to galli et al. (2009), black line; probable trace of the tectonic features investigated in the present work, red lines. a detail in inset. active transpressive surface faulting in north-eastern calabria, southern italy: ... micropaleontological analyses, and overlaying colluvial deposits, radiocarbon data at the holocene, were tilted landwards, folded and offset by ne dipping, sw-verging reverse fault planes. the wsw-ward, uphill sense of motion of these structural features and the local geomorphic characteristics allowed ruling out other causes than tectonics (e.g. landsliding or salt tectonics) as cause of the observed deformations. the offset of the holocene colluvial body testified to the activity of the fault planes in very recent times. the tectonic framework of the region allowed us to hypothesise that the observed shear planes are associated to the activity of a mainly left-lateral strike slip regional shear zone that affects the area, whose evidence have been observed by previous works both onshore (muto et al., 2014; 2015) and offshore (ferranti et al., 2009; 2014). the results of the present study, although preliminary, add new information for understanding the active tectonic and seismotectonic setting of the northeastern calabrian arc. indeed, active surface faulting in the inland sector comprised between northeastern calabria and south-western basilicata regions was related only to extensional structures thus far. instead, this study indicates that active transpressive surface faulting is here likely and has to be considered both for deciphering the present structural relationship between apennines and the calabrian blocks and for planning and managing the land use of the region. ultimately, the identified structures can be the surface expression of a major tectonic structure that could be a candidate as causative fault of the 1836 rossano earthquake, of the ~951 ad seismic event and of future moderate to large magnitude earth quakes in the area. although at an initial stage, the promising results of our work show that future efforts in investigating this area are desirable, to gain a more accurate picture of the seismotectonic characteristics of such a tectonically complex region. acknowledgement we warmly thank fabrizio galadini for his useful discussion on the interpretation of the tectonic deformations. micropaleontological determinations have been made by elsa gliozzi at università degli studi roma tre. we thank her very much. the useful and accurate revisions and comments made by the two referees, eliana poli and pietro mosca, allowed a significant improvement of the paper. we thank bebbè for hosting us in her cosy agritourism many times at contrada amica. references amodio morelli l., bonardi g., colonna v., dietrich d., giunta g., ippolito f., liguori v., lorenzoni s., paglionico a., perrone v., piccarreta g., russo m., scandone p., zanettin-lorenzoni e., zuppetta a. (1976) l’arco calabro-peloritano nell’orogene appenninico maghrebide (the calabrian-peloritan arc in the apennine-maghrebide orogen). memorie della società geologica italiana, 17, 1-60. baccheschi p., margheriti l., steckler m.s. (2008) sks splitting in southern italy: anisotropy variations in a fragmented subduction zone. tectonophysics, 462, 49-67. barone m., dominici r., muto f., critelli s. (2008) detrital modes in a late miocene wedge-top basin, north-eastern calabria, italy: compositional record of wedge-top partitioning. journal of sedimentary research, 78, 693-711. bigazzi g., carobene l. (2004) datazione di un livello cineritico del pleistocene medio: relazioni con sedimentazione, sollevamento e terrazzo marini nell’area crosia-calopezzati in calabria (italia). il quaternario (italian journal of quaternary science), 17 (2/1), 151-163. bordoni p., valensise g. (1998) deformation of the 125ka marine terrace in italy: tectonic implications. in: stewart, i.s. and vita finzi, c. (eds), late quaternary coastal tectonics, geological society. london, special publications, 146, 71-110. brutto f., muto f., loreto m. f., tripodi v., critelli s. (2016) transition from strike-slip to extensional tectonics in the plio-pleistocene catanzaro trough (calabria, south italy). rendiconti online della società geologica italiana, 38, 9-12. carobene l. (2003) genesi, età, sollevamento ed erosione dei terrazzi marini di crosia-calopezzati (costa ionica della calabria-italia). il quaternario (italian journal of quaternary science), 16(1), 43-89. cavazza w., barone m. (2010) large scale sedimentary recycling of tectonic mélange in a forearc setting: the ionian basin (oligocene-quaternary, southern italy). geological society of america bulletin. doi: 10.1130/b30177.1. chiarabba c., de gori p., speranza f. (2008) the southern tyrrhenian subduction zone: deep geometry, magmatism and plio-pleistocene evolution. earth and planetary science letters, 268, 408-423. chiarabba c., piana agostinetti n., bianchi i. (2016) lithospheric fault and kinematic decoupling of the apennines system across the pollino range. geophysical research letters, 43, 3201-3207. cifelli f., mattei m., rossetti f. (2007) the tectonic evolution of arcuate mountain belts on top of a retreating subduction slab: the example of the calabrian arc. journal of geophysical research, 112 (b09101), doi:10.1029/2006jb004848. cinti f.r., m. moro, d. pantosti, l. cucci, d'addezio g. (2002) new constraints on the seismic history of the castrovillari fault in the pollino gap (calabria, southern italy), journal of seismology, 6 (2), 199217. corbi f., fubelli g., lucà f., muto f., pelle t., robustelli g., scarciglia f., dramis f. (2009) vertical movements in the ionian margin of the sila massif (calabria, italy). bollettino della società geologica italiana, 128 (3), 731-738. cosentino d., gliozzi e. (1988) considerazioni sulle velocità di sollevamento di depositi eutirreniani dell’italia meridionale e della sicilia. memorie della società geologica italiana, 41, 653-665. critelli s. (1990) geological setting of the trionto river basin. excursion guidebook, igu-comtag and cnr, «symposium on geomorphology of active tectonic areas», cosenza, june 1990, 67-70. 102 gori s. et al. critelli s., muto f., tripodi v., perri f. (2013) link between thrust tectonics and sedimentation processes of stratigraphic sequences from the southern apennines foreland basin system, italy. rend. online della soc. geol. it., 25, 21-42. cucci l. (2004) raised marine terraces in the northern calabrian arc (southern italy): a ~600 kyr long geological record of regional uplift. annals of geophysics, 47(4), 1391-1406. cucci l., cinti f.r. (1998) regional uplift and local tectonic deformation recorded by the quaternary marine terraces on the ionian coast of northern calabria (southern italy). tectonophysics, 292 (1/2), 67-83. cucci l., tertulliani a. (2006) i terrazzi marini nell’area di capo vaticano (arco calabro): solo un record di sollevamento regionale o anche di deformazione cosismica? il quaternario (italian journal of quaternary science), 19(1), 89-101. d’agostino n., d’anastasio e., gervasi a., guerra i., nedimović m. r., seeber l., steckler m. (2011) geophysical research letters, 38, l17304. doi:10.1029/2011gl048270. de rosis l. (1838) descrizione del tremuoto avvenuto in aprile del 1836, in: cenno storico della città di rossano e delle sue nobili famiglie, 1, pp.88-112, napoli. del ben a., barnaba c., taboga a. (2008) strike-slip systems as the main tectonic features in the plioquaternary kinematics of the calabrian arc. mar. geophys. res., 29, 1-12. doi 10.1007/s11001-0079041-6. diss working group (2015) database of individual seismogenic sources (diss), version 3.2.0: a compilation of potential sources for earthquakes larger than m 5.5 in italy and surrounding areas. http:// diss.rm.ingv.it/diss/, istituto nazionale di geofisica e vulcanologia. doi:10.6092/ingv.it-diss3.2.0. dumas b., gueremy p., hearty p.j., lhenaff r., raffy j. (1988) morphometric analysis and amino acid geochronology of uplifted shorelines in a tectonic region near reggio calabria, south italy. palaeogeography, palaeoclimatology, palaeoecology, 68, 273289. dumas b., raffy j. (2004) late pleistocene tectonic activity deduced from uplifted marine terraces in calabria, facing the strait of messina. quaternaria nova, 8, 79-100. dewey j.f., helman m.l., turco e., hutton, d.w.h., knott s.d. (1989) kinematics of the western mediterranean. in m. p. coward d.d., g. park (eds.), alpine tectonics. geological society of london special publication (vol. 45, pp. 265-283). london: geological society of london. doglioni c. (1991) a proposal of kinematic modelling for w dipping subductions. possible applications to the tyrrhenian-apennines system. terra nova, 3, 423-434. faccenna c., funicello f., giardini d., lucente p. (2001) episodic back-arc extension during restricted mantle convection in the central mediterranean. earth and planetary science letters, 187, 105 -116. faccenna c., piromallo c., crespo-blanc a., jolivet l., rossetti f. (2004) lateral slab deformation and the origin of the western mediterranean arcs. tectonics, 23, tc1012. doi:10.1029/2002tc001488. ferranti l., santoro e., mazzella m. e., monaco c., morelli d. (2009) active transpression in the northern calabria apennines, southern italy, tectonophysics, 476(1-2), 226-251, doi:10.1016/j.tecto.2008.11.010. ferranti l., burrato p., pepe f., santoro e., mazzella m. e., morelli d., passaro s., vannucci g. (2014) an active oblique contractional belt at the transition between the southern apennines and calabrian arc: the amendolara ridge, ionian sea, italy. tectonics, 33, 2169-2194. folino gallo m. (2010) caratteri neotettonici del bordo nord orientale dell’arco calabro. ph.d. thesis, xxi cicle, università della calabria. tutor prof. carlo tansi. galadini f., meletti c., vittori e. (2001) major active faults in italy: available surficial data. netherlands journal of geosciences/geologie en mijnbouw, 80 (3-4), 273-296. galli p., spina v., vilardoi., naso g. (2009) evidence of active tectonics in southern italy: the rossano fault (calabria). in: recent progress on earthquake geology. editor: pierpaolo guarnieri, nova science publishers, inc. isbn: 978-1-60876-147-0. ghisetti f. (1979) evoluzione neotettonica dei principali sistemi di faglie della calabria centrale. bollettino della società geologica italiana, 98, 387-430. ghisetti f. (1980) caratterizzazione dei blocchi della calabria meridionale in base alle velocità di sollevamento nel plio-pleistocene: una proposta di zonazione neotettonica. in: contributi alla realizzazione della carta neotettonica d’italia, parte ii. cnr-pfg, sottoprogetto “neotettonica”, pubblicazione n. 356 del progetto finalizzato geodinamica 775-809. ghisetti f., vezzani l. (1981) contribution of structural analysis to understanding the geodynamic evolution of the calabrian arc (southern italy). journal of structural geology, 3, 371-381. guarnieri p. (2006) plio-quaternary segmentation of the south tyrrhenian forearc basin. international journal of earth sciences (geol. rundsch.), 95, 107 -118. gueguen e., doglioni c., fernandez m. (1998) on the post 25 ma geodynamic evolution of the western mediterranean. tectonophysics, 298, 259-269. kastens k., mascle j., auroux c., bonatti e., broglia c., channell j.,… (1988) odp leg 107 in the tyrrhenian sea: insights into passive margin and backarc basin evolution. geological society of america bulletin, 100, 1140-1156. locati m., camassi r., stucchi m. (eds.) (2011) dbmi11, the 2011 version of the italian macroseismic data-base. milano, bologna, http://emidius.mi.ingv.it/dbmi11, doi:10.6092/ingv. it-dbmi11. malinverno a., ryan w.b.f. (1986) extension in the tyrrhenian sea and shortening in the apennines as result of arc migration driven by sinking of the lithosphere. tectonics, 5, 227-245. mattei m., cipollari p., cosentino d., argentieri a., ros 103 active transpressive surface faulting in north-eastern calabria, southern italy: ... setti f., speranza f. (2002) the miocene tectonic evolution of the southern tyrrhenian sea: stratigraphy, structural and paleomagnetic data from the onshore amantea basin (calabrian arc, italy). basin research, 14, 147-168. milia a., turco e., pierantoni p.p., schettino a. (2009) four dimensional tectonostratigraphic evolution of the southern peri-tyrrhenian basins (margin of calabria, italy). tectonophysics 476, 41-56. minelli l., faccenna c. (2010) evolution of the calabrian accretionary wedge (central mediterranean). tectonics, 29, tc4004. doi:10.1029/2009tc002562 miyauchi t., dai pra g., sylos labini s. (1994) geochronology of pleistocene marine terraces and regional tectonics in the tyrrhenian coast of south calabria, italy. il quaternario (italian journal of quaternary science), 7 (1), 17-34. molin p., dramis f., lupia palmieri e. (2002) the pliocene-quaternary uplift of the ionian northern calabria coastal belt between corigliano calabro and capo trionto. studi geologici camerti vol. spec., 2002, 135-145. monaco c. (1993) pleistocene strike-slip tectonics in the pollino mountain range (southern italy). ann. tecton., 8/2, 100-112. monaco c., tortorici l., nicolich r., cernobori l., costa m. (1996) from collisional to rifted basins: an example from the southern calabrian arc (italy). tectonophysics, 266, 233-249. monaco c., tortorici l., paltrinieri w. (1998) structural evolution of the lucanian apennines, southern italy. j. struct. geol. 20, 617-638. moretti a. (2000) il database delle faglie capaci della calabria. in: le ricerche del gndt nel campo della pericolosita` sismica (1996-1999), galadini f., meletti c., rebez a. (eds.), 219-226, cons. naz. delle res., gruppo naz. per la difesa dai terremoti, roma. moretti a., guerra i. (1997) tettonica dal messiniano ad oggi in calabria: implicazioni sulla geodinamica del sistema tirreno-arco calabro. boll. soc. geol. it., 116, 125-142. muto f., critelli s., robustelli g., tripodi v., zecchin m., fabbricatore d., perri f. (2015) a neogenequaternary geotraverse within the northern calabrian arc from the foreland peri-ionian margin to the backarc tyrrhenian margin. geological field trips, 7(2.2), 65. doi:10.3301/gft.2015.04. muto f., perri e. (2002) evoluzione tettonosedimentaria del bacino di amantea, calabria occidentale. boll. soc. geol. it., 121, 391-409. muto f., spina v., tripodi v., critelli s., roda c. (2014) neogene tectonostratigraphic evolution of allochthonous terranes in the eastern calabrian foreland (southern italy). ital. j. geosci., 133, 455-473. ogniben l. (1962) le argille scagliose e i sedimenti messiniani a sinistra del trionto (rossano cosenza). geologica romana, 1, 255-282. ogniben l. (1969) schema introduttivo alla geologia del confine calabro-lucano. mem. soc. geol. it., 8 (4), 453-763. ogniben l. (1973) schema geologico della calabria in base ai dati odierni, geol. romana, 12, 243-585. olivetti v., cyr a.j., molin p., faccenna c., granger d.e. (2012) uplift history of the sila massif, southern italy, deciphered from cosmogenic 10be erosion rates and river longitudinal profile analysis. tectonics, 31, tc3007. doi:10.1029/2011tc003037. patacca e., scandone p. (1989) post tortonian mountain building in the apennines. the role of the passive sinking of a relic lithospheric slab. in boriani, a., bonafede, m., piccardo, g. b., vai, g. b. (eds.), the lithosphere in italy. advances in earth science research. italian nature communication. international lithosphere program, mid term conf. (rome, may 56, 1987). atti conv. lincei 80, pp. 157-176. parotto m., praturlon a. (2004) the southern apennine arc. in: geology of italy, special volume of the italy geological society for the igc32. florence. crescenti v., d’offizi s., merlino s., sacchi l. (eds), roma, 33-58. piromallo c., morelli a. (2003) p wave tomography of the mantle under the alpine-mediterranean area. journal of geophysical research, 108(b2), 2065. doi:10.1029/ 2002jb001757. presti d., billi a., orecchio b., totaro c., faccenna c., neri g. (2013) earthquake focal mechanisms, seismogenic stress, and seismotectonics of the calabrian arc, italy. tectonophysics, 602, 153-175. robustelli g., lucà f., corbi f., pelle t., dramis f., fubelli g., scarciglia f., muto f., cugliari d. (2009) alluvial terraces on the ionian coast of northern calabria, southern italy: implications for tectonic and sea level controls. geomorphology, 106 (3-4), 165169. roda c. (1967) i sedimenti neogenici autoctoni ed alloctoni della zona di cirò-cariati (catanzaro e cosenza). mem. soc. geol. it., 6, 137-149. rosenbaum g., gasparon m., lucente f.p., peccerillo a., miller m.s. (2008) kinematics of slab tear faults during subduction segmentation and implications for italian magmatism. tectonics, 27, tc2008, doi:10.1029/2007tc002143. rossetti f., goffè b., monié p., faccenna c., vignaroli g. (2004) alpine orogenic p-t-t-deformation history of the catena costiera area and surrounding regions (calabrian arc, southern italy): the nappe edifice of north calabria revised with insights on the tyrrhenian-apennine system formation. tectonics, 23, tc6011, doi:10.1029/2003tc001560. rovida a., camassi r., gasperini p., stucchi m. (eds.) (2011) cpti11, the 2011 version of the parametric catalogue of italian earthquakes. istituto nazionale di geofisica e vulcanologia, milano, bologna. doi: http://doi.org/10.6092/ingv.it-cpti11 royden l., patacca e., scandone p. (1987) segmentation and configuration of subducted lithosphere in italy: an important control on thrust belt and foredeep basin evolution. geology, 15, 714-717. spina v., tondi e., mazzoli s. (2011) complex basin development in a wrench-dominated back-arc area: tectonic evolution of the crati basin, calabria, italy. journal of geodynamics, 51, 90-109. tansi c., muto f., critelli s., iovine g. (2007) neogene -quaternary strike-slip tectonics in the central 104 gori s. et al. calabrian arc (southern italy). journal of geodynamics, 43, 393-414. tortorici g., bianca m., de guidi g., monaco c., tortorici l. (2003) fault activity and marine terracing in the capo vaticano area (southern calabria) during the middle-late quaternary. quaternary international, 101-102, 269-278. tortorici l., monaco c., tansi c., cocina o. (1995) recent and active tectonics in the calabrian arc (southern italy). tectonophysics 243, 37-49. totaro c., koulakov i., orecchio b., presti d. (2014) detailed crustal structure in the area of the southern apennines-calabrian arc border from local earthquake tomography. journal of geodynamics, 82, 87 -97. tripodi v., muto f., critelli s. (2013) structural style and tectonostratigraphic evolution of the neogenequaternary siderno basin, southern calabrian arc, italy. international geology review, 4, 468-481. turco, e., maresca, r., & cappadona, p. (1990) la tettonica plio-pleistocenica del confine calabrolucano: modello cinematico. memorie della società geologica italiana, 45, 519-529. van dijk j.p., bello m., brancaleoni g.p., cantarella g., costa v., frixa a., golfetto f., merlini s., riva m., torricelli s., toscano c., zerilli a. (2000) a regional structural model for the northern sector of the ca-labrian arc (southern italy). tectonophysics, 324, 267-320. vannucci g., pondrelli s., argnani a., morelli a., gasperini p., boschi e. (2004) an atlas of mediterranean seismicity. annals of geophysics, 47(1), 247 -306. vezzani l. (1968) i terreni plio-pleistocenici del basso crati (cosenza). atti dell’accademia gioenia di scienze naturali, catania, ser. vi, 20, 28-84. westaway r. (1993) quaternary uplift of southern italy. journal of geophysical research, 98, 21,741-772. zecchin, m., civile, d., caffau, m., muto, f., di stefano, a., maniscalco, r., critelli, s. (2013) the messinian succession of the crotone basin (southern italy) i: stratigraphic architecture reconstructed by seismic and well data. mar. pet. geol. 48, 455-473. zecchin m., praeg d., ceramicola s., muto f. (2015) onshore to offshore correlation of regional unconformities in the plio-pleistocene sedimentary successions of the calabrian arc (central mediterranean). earth science reviews, 142, 60-78. zecchin m., caffau m., civile d., critelli s., di stefano a., maniscalco r., muto f., sturiale g., roda c. (2012) the plio-pleistocene evolution of the crotone basin (southern italy): interplay between sedimentation, tectonics and eustasy in the frame of calabrian arc migration. earth sci. rev., 115, 273303. active transpressive surface faulting in north-eastern calabria, southern italy: ... 105 ms. received: june 20, 2016 final text received: october 10, 2016 106 << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /none /binding /left /calgrayprofile (dot gain 20%) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /error /compatibilitylevel 1.4 /compressobjects /tags /compresspages true /convertimagestoindexed true /passthroughjpegimages true /createjobticket false /defaultrenderingintent /default /detectblends true /detectcurves 0.0000 /colorconversionstrategy /cmyk /dothumbnails false /embedallfonts true /embedopentype false /parseiccprofilesincomments 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can be opened with acrobat and adobe reader 5.0 and later.) >> /namespace [ (adobe) (common) (1.0) ] /othernamespaces [ << /asreaderspreads false /cropimagestoframes true /errorcontrol /warnandcontinue /flattenerignorespreadoverrides false /includeguidesgrids false /includenonprinting false /includeslug false /namespace [ (adobe) (indesign) (4.0) ] /omitplacedbitmaps false /omitplacedeps false /omitplacedpdf false /simulateoverprint /legacy >> << /addbleedmarks false /addcolorbars false /addcropmarks false /addpageinfo false /addregmarks false /convertcolors /converttocmyk /destinationprofilename () /destinationprofileselector /documentcmyk /downsample16bitimages true /flattenerpreset << /presetselector /mediumresolution >> /formelements false /generatestructure false /includebookmarks false /includehyperlinks false /includeinteractive false /includelayers false /includeprofiles false /multimediahandling /useobjectsettings /namespace [ (adobe) (creativesuite) (2.0) ] /pdfxoutputintentprofileselector /documentcmyk /preserveediting true /untaggedcmykhandling /leaveuntagged /untaggedrgbhandling /usedocumentprofile /usedocumentbleed false >> ] >> setdistillerparams << /hwresolution [2400 2400] /pagesize [612.000 792.000] >> setpagedevice microsoft word 00_indice_bm03 available online http:/amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 25 (1), 2012, 35-40 u/th dating of a cladocora caespitosa from capo san marco marine quaternary deposits (sardinia, italy) maurizio d’orefice1, roberto graciotti1, sergio lo mastro2, cristina muraro1, marco pantaloni1, michele soligo2 & paola tuccimei2 1 ispra, servizio geologico d’italia, rome, italy 2 dipartimento di scienze geologiche, università roma tre, rome, italy corresponding author: r. graciotti <roberto.graciotti@isprambiente.it> abstract: a whole specimen, not reworked and well preserved of cladocora caespitosa has been found within the marine quaternary deposits, outcropping along the eastern coast of the capo san marco promontory. the u/th dating of this sample has provided a minimum age of 70 ± 4 ka b.p. this dating allows to state that these marine deposits, containing the coral, are not holocene in age. keywords: marine quaternary deposits, cladocora caespitosa, u/th dating, tyrrhenian, sardinia. 1. introduction the geological survey of italy, concerning the institutional activities related to the realization of the geological map of italy at 1: 50.000 scale (carg project), has done quick geological surveys to check and monitoring some sample areas of the 528 oristano geological sheet (middle-western sardinia), still in progress. in particular, marine and continental quaternary deposits were taken into account. in the middle-western sardinia, sinis peninsula and eastern coast of the capo san marco promontory, these deposits occurred in peculiar outcroppings which have been studied in detail by several authors (maxia & pecorini, 1968; ulzega et al., 1982; carboni & lecca, 1985; davaud et al., 1991; kindler et al., 1997; melis et al., 2001; lecca & carboni, 2007; andreucci et al., 2009; coltorti et al., 2010; thiel et al., 2010). the research has especially addressed marine quaternary deposits, in relation with a scientific debate which has recently risen about the chronological attribution of these deposits (aiqua, 2007; bartolini et al., 2008; catto, 2010). in the 528 oristano geological sheet “the beach and beach ridge deposits” have been chronologically attributed to holocene age, instead of the upper pleistocene age (tyrrhenian) reported in literature and in the official geological map of italy (regione autonoma della sardegna, 1989). during the field activity many fossils have been collected including a specimen of cladocora caespitosa which has been dated with the u-series method. the aim of this note is to give a additional element to dating the quaternary deposits outcropping in this area of the sardinia region, and to provide a useful contribution to the scientific debate in progress. 2. geological setting the capo san marco promontory, which from a fig. 1 location map of the sinis peninsula (melis et al., 2001; modified). d’orefice m. et al. 36 geomophological point of view extends a few kilometers offshore, represents the end of the sinis peninsula (fig. 1). the western coast consists of an high and steep miocene-pliocene cliff, while the eastern coast, gently dipping seaward, is mainly made of marine and continental quaternary deposits. in this area, in fact, the pre-quaternary bedrock crops out only in a few sites along of the coast where the quaternary deposits were dismantled by the intense wave action. the basal portion of the substrate is represented by the capo san marco formation (cherchi et al., 1978), divided into two facies: the lower one consists of “dark grey clays” and the upper one is made of “marly calcareous deposits”. the outcropping thickness is about 50 m, the age is upper tortonian – lower messinian. the nuraghe baboe formation (spano, 1989) overlies the marly calcareous deposits of the capo san marco formation, with a transgressive unconformity surface. this unit consists of a marine succession made of breccias, conglomerates, sandstones, calcareous sandstones, silty-marly clays, calcarenites and marly fig. 2 satellite view (from google earth) with location of outcrops and sampling point of the cladocora caespitosa. table 1 uranium content, uranium and thorium activity ratios and age of the coral. u/th dating of a cladocora caespitosa from capo san marco … 37 mudstone. the thickness is about 35 m, the age is lower pliocene. the golfo di oristano basalt formation (costa randata facies), unconformably overlying on the previous formations, represents the top and the southern cliff of the promontory. these basalts, dated 3.12 ma (beccaluva et al., 1985), are made of several superimposed flows and their maximum thickness is about 30 m; the occurrence of columnar structures suggests a slow cooling of the lavas. 3. observations on quaternary deposits the quaternary deposits widely crop out in the area of the 528 oristano geological sheet. the best and more complete stratigraphic sections occur near the san giovanni di sinis area, within which some authors recognize different facies (maxia & pecorini, 1968; ulzega et al., 1982; carboni & lecca, 1985; davaud et al., 1991; kindler et al., 1997; melis et al., 2001; lecca & carboni, 2007; andreucci et al., 2009; coltorti et al., 2010; thiel et al., 2010). quaternary deposits have been also recognized along the fossil beach ridge that closes the cabras lagoon. these deposits are formed by thyrrenian bioclastic calcarenites (forti & orrù, 1995). the quaternary deposits crop out without interruption all over the eastern coast of the capo san marco promontory, from the southernmost end up to 1 km to the north of tharros archeological site. these deposits are often fractured, disrupted and prone to fall and topple landslides due to the intense marine erosive processes acting along the coasts of the promontory. at the tip of the promontory the basalts are overlapped by aeolian deposits, made of well cemented fig. 3 la caletta site. geometrical relationships between aeolian and marine deposits. a) front view of the outcrop and presentday tidal notch in the aeolian deposits. b) detail of the marine deposit. c) lateral view of the outcrop. d) detail of the marine deposit clearly capped by aeolian deposit. d’orefice m. et al. 38 fig. 5 the specimen of cladocora caespitosa which has been dated using u/th method. quartz-sandstone, characterized by high angle cross stratification with foresets landward dipping. the aeolian deposits continue below sea level and are characterized by a recently formed tidal notch. these deposits are modelled by a flat marine erosional surface, gently sloping seaward, located at about 4 m above sea level, delimited upslope by a notch of about 50 cm of height. this surface is capped by 1 m-thick marine deposit. the lower portion consists on huge prevailing basalt blocks, well rounded, with a diameter up to 50 cm, in a well cemented, gravelly-sandy matrix, with abundant fossils. the upper part consists of a well cemented level of coarse to medium fossiliferous sandstone. the fossils are mostly bivalves (anomia ephipphium, arca noe, fissurella italica, glycimeris sp., cardium sp., ostreids) and gastropods (murex taurinensis, trochocochlea turbinata, purpura haemastoma, patella ferruginea). the age of the aeolian deposits, assigned using osl dating on a sample collected just above the notch, is 174 ± 13 ka, thus referable to the middle pleistocene (thiel et al., 2010). at la caletta site (fig. 2) a marine deposit crops out at present-day sea level. this deposit is composed by huge meter-sized, well rounded basaltic boulders, in a gravelly-sandy supporting matrix, rich in fossils (ostrea sp., arca noe, glycimeris sp., patella ferruginea, etc.). this sedimentary body, dipping 10° seaward, rise upward for a few meters along the slope. it is completely capped by upper pleistocene aeolian quartz-sandstones which deep below sea level. in this site the geometrical relationships between these deposits can be observed in a three-dimensional view. in fact, it is possible to observe the marine deposits underlying the aeolian sandstones through several joints expanded by marine erosion (fig. 3). northward, in the direction of tharros (figs.1-2), a peculiar beach deposit has been found. this 50 cm-thick layer is made of medium to coarse-grained, well cemented sandstone, rich in mytilus galloprovincialis and other bivalves (fig. 4). this marine deposit is very similar to that described by lecca et al. (2007) and by andreucci et al. (2009) in the sinis peninsula, about 1 km away. in this site a planar bedded sandstone overlying the mytilus galloprovincialis layer has been dated using osl method, providing an age of 120 ± 10 ka (andreucci et al., 2009). during the field survey it was noteworthy the finding of one whole specimen of cladocora caespitosa at about 2.5 m above sea level. this fossil has been collected from marine quaternary deposits unconformably lying on the bedrock with an articulated erosional surface. the specimen not reworked and well preserved has been considered suitable for an isotopic dating according to the u/th method. 4. u/th dating corals are considered excellent samples to be dated with u-series disequilibria methods because in most cases they consist of pure calcium carbonate, free from a detrital component that makes problematic the dating of dirty carbonates. the 230th/234u method is the most widely used dating technique applied to corals and is based on the extreme fractionation of the parent isotopes 238u and 234u from their long-lived daughter 230th in the hydrosphere. uranium, markedly more soluble than th in the surface and near-surface environments, is readily mobilised as the highly soluble uranyl ion (uo2 2+) and its complexes, whereas th is easily hydrolyzed and precipitated or adsorbed on detrital particles. uranium is co-precipitated with caco3 on exsolution of co2, fig. 4 view of the mytilus galloprovincialis layer. u/th dating of a cladocora caespitosa from capo san marco … 39 fig. 6 diffractogram showing the aragonitic (ar) nature of the coral with moderate calcite amount (cc) and detrital fraction: quartz , halite gypsum. while th is generally negligible. in the absence of detrital th, 230th only forms in situ by radioactive decay of co-precipitated u. in a closed system the extent to which the 230th/234u activity ratio has returned towards unity is a function of time, taking into account also the state of disequilibrium between 234u and 238u (kaufman & broecker, 1965). moreover, it is important to verify the original aragonitic nature of the coral and check the eventual presence of calcite. the occurrence of relevant calcite indicate that weathering processes have affected the coral after its burial, with consequent opening of the chemical system. in this case, semi-quantitative x-ray diffractometry analysis has evidenced the aragonitic nature of the coral with the presence of moderate calcite amount (fig. 6) that can be estimated around approximately 10%. about 3 g of coral were ultrasonically washed in deionized water and dissolved in nitric acid. few milliliters of hydrogen peroxide were added and heated at 100 °c in order to destroy organic matter. isotopic complexes of uranium and thorium were extracted according to the procedure described in edwards et al. (1986) and alpha-counted using high resolution ion implanted ortec silicon surface barrier detectors. the age, 70 ± 4 ka, was calculated by means of isoplot/ex (version 3·0), a plotting and regression program designed by ludwig (2003) for radiogenic-isotope data. u-series data are reported in table i. errors are quoted as 1σ. 230th/232th activity ratio, higher than 50, indicates that the coral does not contain a significant detrital fraction. furthermore, the uranium content, about 3 ppm, approaches the average value of uranium abundance in corals and the initial 234u/238u activity ratio (234u/238ui) of the carbonate correspond to that of the marine water. these three data are an evidence of the good quality of the obtained age. 5. conclusions the u/th dating on a sample of cladocora caespitosa has provided an age of 70 ± 4 ka b.p. the specimen of cladocora caespitosa, not reworked and well preserved, was sampled at about 2.5 m above sea level within the marine quaternary deposits, overlying the miocene-pliocene bedrock, along the eastern coast of the capo san marco promontory. the diffractometric analysis showed the sample is mainly composed by aragonite. for the u/th dating must be taken into account the occurrence of the calcite which could cause the rejuvenation of the samples. in this case study, considering the modest quantities of calcite, the age of 70 ± 4 ka b.p. represents the minimum age of the sample. based on these considerations and with reference to the isotopic curve related to the last 300 ka (martinson et al., 1987) the examined sample can be located at the end of the isotopic stage 5 even assuming the rejuvenation of the sample for the presence of moderate calcite amount (fig. 6). this finding agrees with the results reported in dorale et al. (2010) and tuccimei et al. (2010), inferred from phreatic overgrowths on speleothems in coastal caves of mallorca (balearic islands spain). these authors assert that the western mediterranean relative sea level stood at about 1m above present sea level during marine isotope stage (mis) 5a, between ~ 82 and 80 ka ago. furthermore, the data of mallorca coastal caves, show good coherence with those observed from tuccimei et al. (2012) in the capo caccia area (north-western sardinia), located not far from capo s. marco. the u/th dating of cladocora caespitosa allows to state that the marine deposits outcropping along the eastern coast of the capo san marco promontory are not holocene in age, as reported in the documents and maps up to now realized for the 528 oristano geological sheet, still in progress. references aiqua (2007) notizie d’interesse. il quaternario, 20 (1), 85. andreucci s., pascucci v., murray a.s., clemmensen l.b (2009) late pleistocene coastal evolution of san giovanni di sinis, west sardinia (western mediterranean). sedimentary geology, 216, 104116. bartolini c., bonfiglio l., carrara c.,carraro f., ciaranfi n., girotti o., vai g. (2008) commenti e repliche. il quaternario, 21 (1b), 375-376. beccaluva l., civetta l., macciotta g.p., ricci c.a. (1985) geochronology in sardinia: results and problems. rend. soc. it. min. petr., 40, 57-72. carboni s., lecca l. (1985) osservazioni sul pleistocene medio-superiore della penisola del sinis (sardegna occidentale). boll. soc. geol. it., 104, 459-477. catto n. (2010) geomorphology, stratigraphy and facies analysis of some late pleistocene and holocene key deposits along the coast of sardinia (italy),” and “geochronology for some key sites along the coast of sardinia (italy)”: a note from the editor-in-chief. quaternary international, 222, 17-18. cherchi a., marini a., murru m., robba e. (1978) strad’orefice m. et al. 40 tigrafia e paleoecologia del miocene superiore della penisola del sinis (sardegna occidentale). riv. it. paleont. strat., 84(4), 973-1036. coltorti m., melis e., patta d. (2010) geomorphology, stratigraphy and facies analysis of some late pleistocene and holocene key deposits along the coast of sardinia (italy). quaternary international, 222, 19-35. davaud e., kindler p., martini r., strasser a. (1991) enregistrement des variations eustatiques dans des dépôts littoraux du pleistocéne supérieur san giovanni di sinis (sardaigne occidentale). bull. soc. géol. fr., 162, 523-533. dorale j.a., onac b.p., fornós j.j., ginés j., ginés a., tuccimei p., peate d.w. (2010) sea-level highstand 81,000 years ago in mallorca. science, 327, 860-863. edwards r.l. (1988) high precision thorium-230 ages of corals and the timing of sea level fluctuation in the late quaternary. ph.d. thesis, california institute of technology, pasadena california, usa. edwards r.l.,chen, j.h., wasseburg g.j. (1986) 238u234u230th-232th systematics and the precise measurement of time over the past 500 000 years. earth planet. sci. lett. 81, 175-192. forti s., orrù p. (1995) geomorfologia costiera e sottomarina della penisola del sinis (sardegna occidentale). boll. soc. geol. it., 114, 3-21. kaufman a, broecker w.s. (1965) comparison of 230th and 14c ages of carbonate materials from lakes lahantan and bonneville. journal of geophysical research 70, 4039-4054. kindler p., davaud e., strasser a. (1997) tyrrhenian coastal deposits from sardinia (italy): a petrographic record of high sea levels and shifting climate belts during the last interglacial (isotopic stage 5e). pal. pal. pal., 133, 1-25. lecca l., carboni s. (2007) the tyrrhenian section of san giovanni di sinis (sardaigne): stratigraphic record of an irregular single high stand. riv. it. paleont. strat., 113(3): 509-523. ludwig k.r. (2003). using isoplot/ex, version 3. a geochronological toolkit for microsoft excel. berkeley geochronology ctr. spec., pub. 4. maxia c, pecorini g. (1968) il quaternario della sardegna. atti x° congresso internazionale di studi sardi, 247-266. melis r.t., palombo m.r., mussi m. (2001) mammuthus lamarmorae (major, 1883) remains in the pretyrrhenian deposits of s. giovanni di sinis (western sardinaia, italy). in: g. cavaretta, p. gioia, m. mussi & m.r. palombo (eds.). “the world of elephants”, pubbl. cnr, roma, 2001, 481-485. martinson d.g., pisias n.g., hays, j.d., imbrie, j.d., moore t.c., shackleton n.j. (1987) age dating and the orbital theory of the ice ages: development of a high-resolution 0 to 300,000-year chronostratigraphy. quaternary research, 27, 1-29. regione autonoma della sardegna (1989) carta geologica d’italia alla scala 1:100.000: fogli 216-217 “capo s. marco – oristano”. spano c. (1989) macrofauna circalitorale del pliocene inferiore di capo s. marco (sardegna occidentale). riv. it. paleont. strat., 95(2), 137-172. thiel c., coltorti m., tsukamoto s., frechen m. (2010) geochronology for some key sites along the coast of sardinia (italy). quaternary international, 222, 36-47. tuccimei p., onac b.p., dorale j.a., fornós j.j., ginés j., ginés à., spada g., ruggieri g., mucedda m. (2012) decoding last interglacial sea-level variations in the western mediterranean using speleothem encrustations from coastal caves in mallorca and sardinia: a field data model comparison. quaternary international. doi: 10.1016/j. quaint 2011.10.032, article in press tuccimei, p., soligo, m., ginés, j., ginés, a., fornós, j., kramers, j., villa, i.g. (2010) constraining holocene sea levels using u-th ages of phreatic overgrowths on speleothems from coastal caves in mallorca (western mediterranean). earth surface processes and landforms 35 (7), 782-790. ulzega a., ozer a., lecca l., leone f., pecorini g. spano c., cordy m.j. (1982) comptes-rendus de l’excursion-tablr ronde sur le tyrrhenien de sardaigne. cagliari 21-28 avril 1980/ inqua (livretguide), 88 pp. ms. received: february 3, 2012 final text received: march 5, 2012 amq59 farina bianucci post 19102017.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 30 (1), 2017, 69-74 the holocene ursus arctos from "abisso oriano coltelli" cave (apuan alps, tuscany, central italy) simone farina 1, giampaolo bianucci 2 1 natural history museum, university of pisa, calci (pi), italy 2 natural history museum of the mediterranean (honorary curator), livorno, italy corresponding author: s. farina <simone.farina@unipi.it> abstract: the study of a prime adult female skeleton of brown bear, ursus arctos, found in "abisso oriano coltelli" cave is here reported. a new bone formation on the thoracic vertebrae was investigated by x-ray examination suggesting a longitudinal ligament injury caused by a circumscribed trauma, with ossified hematoma. the specimen was dated providing a conventional age of 6480 ± 40 14c ka bp (holocene). the bear died from non-violent causes, probably during hibernation. the “abisso oriano coltelli” mammal assemblage also includes capra hircus, martes foina and indeterminate small mammals. standard archaeozoological parameters (nisp, mni) have been used to calculate the relative frequency of each taxon identified in the faunal assemblage. keywords: mammals, brown bear, tuscany, central italy, holocene 1. introduction the fossil record of ursidae from the apuan alps (northern tuscany) includes the exceptionally rich amount of late pleistocene remains of ursus spelaeus from equi cave (ghezzo et al., 2014) and from wind cave (piccini et al., 2003). the "abisso oriano coltelli" cave (44°05'35,0 n, 10°14'47,0" e, labelled t/lu 642 in the tuscan register of caves) (fig.1) opens 1209 m a.s.l on the western slope of "monte alto di sella" (apuan alps). the cave was explored in 1976 to a depth of 730 m by the speleological and archaeological group of leghorn and by the speleological group of lucca. in the early 1990’s the speleological and archaeological group of leghorn explored new branches of this cave and in july 1994 they found the mammal assemblage studied in this paper. the topographic survey of "abisso coltelli" revealed that the extremity of one of its newly explored branches was very close to the exterior of the cave. this new branch was opened in 1998 at 1305 m a.s.l. (fig. 2) and the fossil material was collected in the august of 1998. in this paper the study of the brown bear (ursus arctos) remains retrieved from "abisso coltelli" is presented. fig.1 map of the tuscany. the symbol * represent the geographic position of the "abisso coltelli" cave 2. materials and methods the material is housed at the natural history museum of the university of pisa and consists of 486 investigated specimens, 127 of which belong to an individual skeleton of ursus arctos. the lists of the studied specimens and of the measurements are reported in tables (1-4). the number of specimens is reported in parenthesis. the tables report also the side of the bones (right / left) and the preservation (complete / incomplete / fragment). the measurements (in mm), with the exception of the ulna, tibia and fibula of the brown bear, have been taken on the right bones. the standard quantification units nisp (number of identified specimens) and mni (minimum number of individuals) (lyman, 1994; lyman, 2008; reitz & wing, 2008) have been calculated to evaluate the relative frequency of each taxon identified in the faunal assemblage. mni was assessed both on post-cranial and cranial specimens, taking into account age and size. the measurements of the mammal bones were taken adopting the measuring points indicated by von den driesch (1976). the legend for abbreviations of the measurements are the following: lcr: length of the cheektooh row; lmr: length of the molar row; lrt: length of the tooth row from canine to the first molar; gb: greatest breadth; gl: greatest length; h: greatest height; lapa: greatest length of the arch including the processus articulares caudales; lcde: greatest length of the body including the dens; glp: greatest length of the processus articularis; hs: height along the spine; bp greatest breadth of the proximal end; bd: greatest breadth of the distal end. in the 2000 a specimen of ursus arctos was sent to beta analytic inc. laboratory (miami, florida, usa) for radiometric dating. the collagen was extracted using alkaline solutions. the specimen was subjected to accelerator mass spectrometry (ams) analysis. both the conventional and the calibrated radiocarbon datings that were obtained are reported in the text. the conversion from conventional to calibrated ages was accomplished following stuiver et al. (1998). to assess the ontogenetic age of the brown bear we used the age-scoring technique proposed by stiner (1998). the age-scoring technique is an eruption and wear scheme based on cheek teeth. the scheme recognises nine successive stages of crown growth and wear. stiner (1998) advised clustering the eruption–wear stages into three age categories, juveniles (stages i fig. 2 longitudinal section of "abisso coltelli" cave. the symbol * represent the point where the faunal assemblage was discovered. 70 farina s. & bianucci g. tab. 2 list of martes foina specimens from "abisso oriano coltelli" cave. tab. 4 nisp and mni of identified taxa present in the "abisso coltelli" faunal assemblage. 71 the holocene ursus arctos from "abisso oriano coltelli" cave (apuan alps, tuscany, ... tab. 1 list of ursus arctos specimens from "abisso oriano coltelli" cave with the side, the state of preservation, and measurements (in mm) (explanation of the symbols in text). metacarpals: ii, iv and v right and ii, iii, iv and v left; metatarsal: v right. carpal bones: left trapezoid, left capitate, left pisiform, left pyramidal and left scapho-lunate bone, right trapezium, right and left uncinate. tarsal bones: left navicular bone, right intermediate cuneiform bone. tab. 3 list of capra hircus specimens from "abisso oriano coltelli" cave. iii), prime adults (stages iv vii), and old adults (stages viii ix). the vertebral column of the brown bear studied here presents new bone formation on the 4th and the 11th thoracic vertebrae. the latter in particular shows two lesions, whose features were investigated with x-ray techniques. 3. results the mammal assemblage includes a single individual of ursus arctos (tab. 1), 4 individuals of martes foina (tab. 2), and a single individual of capra hircus (tab. 3). the nisp and mni counts are reported in tab. 4. of the 486 specimens examined here, 6 could be determined only anatomically. the indeterminate fragments are 166 and 88 of them belong to rodents. 3.1. ursus arctos the sagittal crest of the brown bear skull is weak and limited to the nuchal region. the temporal windows are small in size and the zygomathic bones are slender. these characteristics are consistent with a female individual. based on the dental wear stage, the individual is a prime adult (stage vi) (figs. 3-4). the skull is fractured in the nuchal region, lacking part of the right frontal and parietal bones (fig. 5). based on the jagged edges of the fractures surface, the bones were broken in a dry state (villa & mathieu, 1991), suffering a post mortem damage. the postcranial bones are unaltered. the 11th thoracic vertebra shows two elongated, symmetrical lesions, located on the outerventral face of the vertebral body. there is evidence of an ossified hematoma (fig. 6). hence, there was ligament injury, caused by a circumscribed trauma. the xray examination (figs. 7-8) also revealed bone thickening near the neighbouring vertebral endplates, which can be interpreted as a probable reparative bone sclerosis. similarly to the other mammal remains from the cave, the skeleton of the female bear shows no evidence of carnivore ravaging. hence, the animal was not killed during hibernation or transported into the cave by other predators. the specimen (sample beta-143383) sent for radiometric dating gave a conventional radiocarbon age of 6,480±40 14c ka bp (7445-7310 cal ka bp). the 13c/12c ratio was -20.3‰. 3.2. capra hircus and martes foina the most diagnostic bones that permitted to attested the presence of a single individual of capra hircus are the right metatarsal and the right calcaneus. the metatarsal is short and relatively broad (tab. 3) and the sagittal ridges of the distal articular surface converge, whereas in the sheep they run practically parallel (prummel & frisch, 1986). in the right calcaneus, the corpus calcanei is straight to convex and between the sustentaculum tali and the medial articular surface of the processus anterior the fig. 3 ursus arctos l. ventral dorsal view of the skull. the scale bar is 5 cm. fig. 4 ursus arctos l. dorsal view of the mandible. the scale bar is 5 cm. fig. 5 ursus arctos l. dorsal view of the skull. the scale bar is 5 cm. 72 farina s. & bianucci g. fig. 6 ursus arctos l. ventral a and posterolateral b and c views of the 10th12th thoracic vertebrae segment. the scale bar is 5 cm. fig. 7 ursus arctos l. x-ray (ventral b and lateral a view) of the 10th12th thoracic vertebrae segment. fig. 8 ursus arctos l. x-ray (ventral a and lateral b view) of the 11th thoracic vertebra. 73 the holocene ursus arctos from "abisso oriano coltelli" cave (apuan alps, tuscany, ... two articular surfaces are fused with each other (prummel & frisch, 1986). the identification of the beech marten was based on the postcranial bones (baumann & gornetzki, 2017). in particular the shape of the atlas, where both processus transversales were tapered cranially, the axis, where the processus spinosus is markedly thickened and the scapula, where the shape of the metacromion is significant thicker in comparison with the one of the pine marten. the postcranial bones of the goat and the beech marten individuals are unaltered. 4 discussion and conclusion based on its radiocarbon dating the female prime adult brown bear carcass from "abisso coltelli" is of early holocene age. similarly to the ursus spelaeus from chiostraccio cave (martini et al., 2014) the abisso coltelli bear died from non-violent causes, either trapped in the cave, as probably happened also to the other associated mammals, or during hibernation. in the first option, the absence of fractures in the postcranial bones of the bear as well as in those of the other associated species suggests that the animals did not fall into the cave and that the latter was easy to penetrate. the lesion on the 11th thoracic vertebra is an injury that the bear had sustained in the past, but healed before the death in the cave. it was therefore not caused by a fall from height. the absence of carnivore ravaging evidence on the bones gives weight to the second hypothesis, in spite of stiner’s (1998) warning that hibernation-related deaths in wear stages v and vi are usually rare. in this case the young bear would have died from starvation, or disease. the associated occurrence of martes foina and capra hircus indicates that the mammal association was probably accumulated attritionally over a certain period of time. in fact bears make considerable effort to keep secret their hibernation lairs to reduce the risk of intrusion and any minimal disturbance will draw a bear away (stiner, 1998). under this perspective, the goat and marten individuals died the same way as the bear. acknowledgements we wish to thank prof. gino fornaciari for the diagnosis of the lesions on the vertebral column and the speleological and archaeological group of leghorn for the recovery of the fossil material. references baumann c., gornetzki k. (2017) postcranial differendifferences in sex and species of pine marten (martes martes l., 1758) and beech marten (martes foina erxl., 1777). palaeodiversity, 10(1), 7-23. ghezzo e., palchetti a., rook l. (2014) recovering data from historical collections: stratigraphic and spatial reconstruction of the outstanding carnivoran record from the late pleistocene equi cave (apuane alps, italy). quaternary science reviews, 96, 168-179. lyman r. l. (1994) vertebrate taphonomy. cambridge manual in archaeology, usa, pp. 524. lyman r. l. (2008) quantitative paleozoology. cambridge manual in archaeology, usa, pp. 348. martini i., coltorti m., mazza p.p.a., rustioni m., sandrelli f. (2014) the latest ursus spelaeus in italy, a new contribution to the extinction chronology of the cave bear. quaternary research, 81, 117-124. prummel w., frisch h.j. (1986) a guide for the distinction of species, sex and body side in bones of sheep and goat. journal of archaeological science, 13(6), 567-577. piccini l., borsato a., frisia s., paladini r., salzani r., sauro u., tuccimei p. (2003) concrezionamento olocenico e aspetti geomorfologici della grotta del vento (alpi apuane lucca): analisi paleoclimatica e implicazioni morfogenetiche. studi trentini scienze naturali, acta geologica, 80, 127138. reitz e.j., wing e.s. (2008) zooarchaeology. cambridge manual in archaeology, usa, pp. 533. stiner m.c. (1998) mortality analysis of pleistocene bears and its paleoanthropological relevance. journal of human evolution, 34(3), 303-326. stuiver m., reimer p.j., bard e., beck j.w., burr g.s., hughen k.a., kromer b., mccormac g., van der plicht j., spurk m. (1998) intcal98 radiocarbon age calibration, 24,000-0 cal bp. radiocarbon 40 (3), 1041-1083. villa p., mahieu e. (1991) breakage patterns of human long bones. journal of human evolution, 21, 27-48. von den driesch a. (1976) a guide to the measurement of animal bones from archaeological sites. peabody museum of archaeology and ethnology harvard university, usa, pp.137. ms. received: november 1, 2016 final text received: july 18, 2017 74 farina s. & bianucci g. << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /none /binding /left /calgrayprofile (dot gain 20%) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /error /compatibilitylevel 1.4 /compressobjects /tags /compresspages true /convertimagestoindexed true /passthroughjpegimages true /createjobticket false /defaultrenderingintent /default /detectblends true /detectcurves 0.0000 /colorconversionstrategy /cmyk /dothumbnails false /embedallfonts true /embedopentype false /parseiccprofilesincomments true /embedjoboptions true /dscreportinglevel 0 /emitdscwarnings false /endpage -1 /imagememory 1048576 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/pdfxoutputintentprofileselector /documentcmyk /preserveediting true /untaggedcmykhandling /leaveuntagged /untaggedrgbhandling /usedocumentprofile /usedocumentbleed false >> ] >> setdistillerparams << /hwresolution [2400 2400] /pagesize [612.000 792.000] >> setpagedevice amq short notes 26_2 zerboni divito monegato available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 25 (2), 2012, iii v report on the geoevent “discovering volcanoes”, sponsored by aiqua, at the vesuvius observatory museum (ingv) mauro antonio di vito, giovanni ricciardi, tullia uzzo, sandro de vita istituto nazionale di geofisica e vulcanologia, sezione di napoli osservatorio vesuviano, naples, italy corresponding author: m.a. di vito <mauro.divito@ov.ingv.it> abstract: a brief summary of the activities carried out on 20th october 2012 at the vesuvius observatory museum for the geoevent of planet earth week, “discovering volcanoes”, sponsored by aiqua. keywords: osservatorio vesuviano, communication, earth sciences, volcanoes . on october 20th 2012, the planet earth week geoevent “discovering volcanoes”, an event organized under the patronage of the italian association for quaternary research (aiqua), the vesuvius observatory museum (move, fig. 1) played host during an interesting day devoted to instruction about volcanic phenomena. this occasion for awareness-raising was given an enthusiastic reception by members of the public thanks to the communication skills of numerous researchers who were able to combine science, history and art so as to convey important information regarding volcanic hazards, using as a base extraordinary records from the past, some of which are unpublished. in the vesuvius observatory museum’s prestigious luigi palmieri room (fig. 2), several films of vesuvius eruptions were shown, beginning with a short footage from 1898 made by the lumière brothers two years after their invention of the moving picture camera. the two brothers visited naples that year to film scenes of daily life and city landmarks. in the background of their shots of the dock, vesuvius in eruption may be seen. the lumière brothers thus filmed a volcanic eruption for the first time ever, illustrating the activity of vesuvius which in the four years from 1895 had formed colle umberto, a lava dome named after the king of italy, umberto i. pag iii fig. 1 the historic seat of the vesuvius observatory, first home of the oldest volcanological observatory in the world. di vito a. et al. iv fig. 2 moments during the event in the palmieri room of the prestigious seat of the vesuvius observatory in ercolano. fig. 3 the collection of lava medals on display for the occasion in the room that housed the volcano exhibition: multimedia voyage into the world of volcanoes. another footage of great interest and scientific value was that of the 1906 eruption, vesuvius’ largest of the 20th century. the seven-minute-long film was made by two neapolitan photographers, the troncone brothers, who sent it to a cinema exhibition in paris, where the spool was lost. a copy of the footage turned up as part of a popular film about volcanoes and earthquakes produced in america in the 1920s – today part of the patrimony of the vesuvius observatory museum. the recovery of this film was of great importance, since apart from the unique 1906 shots, it also contains footage taken immediately after the 1908 messina earthquake by a sailor on the russian battleship makarov, which intervened to give aid to the populace. the last film screened, in full, was that of the 1944 eruption made by the allied forces during the second world war and donated to the director at the time, giuseppe imbò. more than 300 members of the public took part in the geoevent, showing a keen interest in and appreciation of the initiative, and afterwards participated in the visit to the museum, where expert guides led those present on an extraordinary journey through the world of italian volcanoes and the geothermal energy that can be obtained from them. by means of panels and exhibits on italian volcanoes and geothermal energy, audiovisuals, a multimedia panel and a 3d-movie room, visitors were given information about italy’s active volcanoes and the danger they pose, and the systems adopted by the national institute of geophysics and volcanology (ingv) for monitoring their activities. the visit also permitted an appreciation of what may be considered the vesuvius observatory museum’s treasures, the precious assemblage of rocks, volcanic ash and lava medallions housed in the old bourbon building, and in particular the collections of meteorological and seismological instruments, from the oldest electrometers and seismoscopes to the world’s first electromagnetic seismograph, built by palmieri in 1856, up to more modern versions. the museum also recounts the progress of volcanology and seismology, which owed their birth and much of their development to past directors of the vesuvius observatory, starting with macedonio melloni, luigi palmieri, giuseppe mercalli and alessandro malladra. particular interest was aroused by the collection of medallions in vesuvian lava, the only one of its kind, which bears witness to moments in the social, political and scientific world that surrounded the volcano; they were stamped onto still-fluid lavas (fig. 3) that erupted from vesuvius between 1819 and 1944. the event also provoked considerable interest in the national and international press, which released pictures of the day’s highlights in italy and numerous other countries. ms. received: september 6, 2013 final text received: september 6, 2013 discovering volcanoes v vi amq_28(2) cop e sn 12_2015.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 28 (2), 2015, iii vi in memory of alfredo bini giuseppe orombelli with the help of luisa zuccoli, valter maggi and andrea zerboni department of environmental and earth sciences – university of milano-bicocca, italy corresponding author: g. orombelli <giuseppe.orombelli@unimib.it> there are always sentiments of sadness and regret in remembering those, old masters or colleagues, who have left us, but it is especially sad and moving in commemorating colleagues and friends younger than we are, who have suddenly and unexpectedly departed, leaving in those who remain the painful and unforeseen absence of a person with whom we have shared years, interests, passions, topics of research and discussion. alfredo bini suddenly died on 30 april 2015, in the department of earth sciences of the university of milan, while preparing with the colleagues field excursions for the students. on thinking of his demise, recollections accumulated with the passing of time re-emerge to suggest where to start in a commemoration that would not be a mere, brief description of alfredo bini's scientific results. alfredo bini on a field geological campaign on lake garda with a group of students (courtesy of l. zuccoli) in a short note it is quite difficult to fully and properly describe the amount of work done by alfredo, now to be found in over three hundred of his publications, and come up with the most significant ones. alfredo bini was born in cairo on 8 january 1948. in october 1973, he received his degree in medicine in milan and began a brilliant career as a researcher in the biomedical field. in the years 1974 and 1975, with a grant from the italian national research council, he worked at the pharmacology institute of the university of milan and published the results of his studies with his co-workers in prominent international scientific journals. but for some time his interests were focused on an entirely different world: that of karst caves. as a student, and up to his graduation, he had already published nineteen papers on caves and added another dozen while performing his post-graduate work in pharmacology. i cannot recall the year, but it was around 1975 or 1976, when alfredo appeared before me saying that he wanted to matriculate in geology because he wanted to study caves scientifically and full time as a geologist. i imagine that i tried to dissuade him: leaving such an important scientific sector in which he had already worked so brilliantly for one with few job opportunities seemed to be a folly. i am sure i also said that at that time the institute of geology in milan had no scientific interest in speleology. but then i saw alfredo's character, firm and decided, and i should add obstinate, if this adjective did not have a prevalently negative connotation. alfredo graduated as a geologist in february 1982, with a thesis entitled “geologia e geologia del glaciale del monte san primo” (geology and glacial geology of mount san primo). he had been obliged to accept another subject of study, but at least it was in the area of como's prealps, where he knew every cave and ravine. thus alfredo began his studies on glacial deposits, which he never abandoned, as well as those on subterranean karst and speleogenesis, even trying to connect them. he was admitted to post-graduate courses and received his doctorate in 1987, with a dissertation entitled: "l'apparato glaciale würmiano di como" (the würmian glacial system of como). in the meantime, forging ahead in the same year, he became an associate professor of physical geography (with tenure starting from 1988) in the degree course of geological sciences of the university of milan, thanks to the research activities he had been performing for more than a decade. in his cv he had some eighty papers, mostly on the subject of speleology, but also a few on the quaternary and geomorphology of the como region, among which the note prepared together with m.b. cita and m. gaetani on the hypothesis of the origin of the italian prealpine lakes in connection with the messinian salinity crisis (1978). those were the times! in those years the increase in the number of students made possible the creation of new chairs in the different disciplines and the entry of new professors. in this position of total autonomy alfredo developed his research. starting from his dissertation on the como glacial deposits, he began a systematic survey of the quaternary deposits of the large piedmont glacier systems, from that of verbano to that of garda and then expanded into the prealpine and alpine environments. through a reflection on the stratigraphic criteria applicable to quaternary continental deposits and their experimentation, alfredo bini has certainly made a great contribution to the affirmation in recent italian official geological cartography of the unconformity -bounded stratigraphic units, introduced to provide major objectivity and ductility in the survey of continental deposits, also in response to the acknowledged multiplicity of glacial and interglacial climatic cycles and minor glacial oscillations. these criteria, still in the process of being more accurately defined, were used by bini in the geological map of the province of bergamo at the scale of 1:50,000, published in the year 2000. in his monograph of 2001, “geologia del mendrisiotto (messiniano, pliocene, quaternario)” (geology of the mendrisio region messinian, pliocene and quaternary) with a 1:25,000 geologic map, he clearly delineated the methods he used, described the recognized units and reconstructed the subsequent phases of glacial expansion, with sketches and detailed maps. bini, together with other quaternary scientists, made numerous contributions to the definition of the guidelines and rules for the surveying of quaternary continental deposits for the italian geological service. geological mapping experiments at the scale of 1:10,000 in different prealpine and alpine contexts, as part of the “cartografia geologica (carg)” project, preceded the systematic surveys for the sheets of the 1:50,000 italian geological map. alfredo bini was the director (or supervisor) of surveys on the neogene-quaternary units of as many as eleven 1:50,000 geological maps, from the piedmont to the alpine sectors of lombardy. it is known that the new italian 1:50,000 maps have led to a decisive reassessment of quaternary continental deposits, in the sense that much attention has been devoted to them. they are no longer considered an indistinct cover hiding the bedrock, but rather a complex and sensitive skin, varied and rich in geological information of scientific as well as practical interest. there has been a consequent explosion of units that have been recognized and mapped in the different main watersheds. while this allowed to obtain a much greater detail and objectivity (with advantages in knowledge and proper land use), it has also created difficulties in chronological and stratigraphic iv orombelli g. attributions, correlations and syntheses. the complexity of stratigraphic relations between the different units can be seen for example in a schematic drawing in the lower margin of sheet 099 iseo of the 1:50,000 geological map, which shows graphically and concisely the unconformity-bounded units, the discontinuity surfaces that delimit them, their lithology and morphology. on the iseo sheet, mainly representing a prealpine mountainous area, about sixty bedrock units and forty continental neogene and quaternary units have been mapped. on the nearby clusone sheet, thirty -three bedrock units and sixty units of surficial continental deposits have been mapped. of these, forty-two are attributed to the quaternary and eighteen are considered of mio-pliocene age. and we could continue in this way. in the illustrative notes, the chapters on the surficial deposits are just as voluminous, if not more so, than those devoted to the bedrock units. in more recent years, bini took an interest in the morphology and quaternary deposits in the high alpine valleys as well, in particular in valtellina and val chiavenna, on topics such as the lateglacial, the holocene glacier fluctuations, the deep-seated gravitational slope deformations, the evolution of the relief and so on. it is easy to foresee that the knowledge alfredo accumulated on quaternary deposits and glacial history of the vast sector of the alps he studied and surveyed will remain for a long time as a construction that cannot be overlooked by those who wish to continue these studies. the mass of analytical data that he systematically collected and described awaits a synthesis, which alfredo has several times outlined and progressively implemented: only advances of knowledge and of dating techniques will allow to complete this work. together with his research and interests in the evolution of lombardy's territory in the quaternary, and in particular the reconstruction of the many glacial cycles and phases, alfredo kept alive his passion and study of subterranean karst, especially in the como prealps. if at the beginning his production covered different topics of speleology, ranging from exploration, to morphology, mineralogy, biology, meteorology and so on, his investigations gradually became more sharply focused on the genesis of caves, their relationship with surface karst features and the evolution of regional geomorphology. to be remembered in particular are his studies, together with other colleagues, on the geochemistry and dating of cave concretions, which are important in many fields, such as neotectonic studies. his attention was attracted especially by the karst morphology of the grigne group /(lecco). his monograph on the moncodeno karst is memorable, but these few lines are not sufficient to give a true idea of how much he produced in this sector. i shall cite just one final review paper by several authors on a subject that alfredo studied for many years. i refer to the article by dubois et al. (2014) that appeared recently in earthscience reviews “the process of ghost-rock karstification and its role in the formation of cave systems”. in this article, the development of subterranean karst systems appears not to take place by means of a single process of gradual and total removal through dissolution of carbonate rocks. there is a great deal of field evidence which instead shows a two-stage process, similar to that of deep weathering and denudation acting on insoluble rocks (e.g. granitoids). the first stage is thought to be deep chemical weathering by dissolution of the more soluble components which leaves a “ghost rock” (alterite) made of the less soluble components, separated from the unaltered rock by a sharp weathering front. the second stage, which involves increased energy of the system, is thought to lead to mechanical erosion of the “ghost rock”. this is a new hypothesis which certainly finds corroboration in contexts of impure carbonate rocks such as the moltrasio limestone in the como region, a deeply karstified thick well-bedded formation of clayey-siliceous limestone. alfredo bini also took to heart his teaching and the dissemination of scientific information, with textbooks and popular science writings. it was in his nature to surround himself with friends and organize groups, to urge his students on through his love for his studies and his overflowing cheerfulness. those who knew him still can hear his strong, solid voice and his disarming and loud laugh. i do not know the exact number, but i believe that alfredo assigned and supervised a huge number of fieldgeology master and phd thesis, carefully checking the geologic mapping, with great commitment and assiduity. in the most touching tribute at the last farewell at mandello, on 2 may 2015, with alfredo’s photographs shown in sequence on a screen (he was an excellent photographer of landscapes and portraits), his thoughts, his poems (yes, beautiful poems i would never have imagined it!) and the testimonials of his friends, his wife luisa read a passage from le città invisibili (invisible cities) by italo calvino, one that he loved and that reflects his way of conducting research. here is the passage translated from the italian: marco polo describes a bridge, stone by stone. “but which is the stone that supports the bridge?" kublai khan asks. “the bridge is not supported by one stone or another," marco answers, "but by the line of the arch that they form.” kublai khan remains silent, reflecting. he then adds: “why do you speak to me of the stones? it is only the arch that matters to me.” polo replies: “without stones there is no arch.” i recall that the classic textbook géologie stratigraphique by gignoux (the father of the calabrian v alfredo bini stage), on which the geologists of my generation studied, had at the beginning of the foreword this sentence (in italian): un fatto è come un sacco: vuoto, non si regge. perché si regga, bisogna prima farci entrar dentro la ragione pirandello, sei personaggi in cerca d’autore (a fact is like a bag: empty it cannot stand. so that it can stand it must first be filled with reason – pirandello, six characters in search of an author). stratigraphy is certainly based on the collection of facts, but for them to stand they need an idea that supports them, that holds them together. this was the task that alfredo assigned to himself: that of a slow, tenacious, relentless constructor: the choice of the stones, one by one, to build a bridge that stands. thank you and farewell, alfredo. ms. received: november 16, 2015 final text received: november 19, 2015 vi alfredo bini at work on the alps (courtesy of l. zuccoli) orombelli g. amq103 forno et al.pub deep-seated gravitational slope deformation effects on quaternary deposits in the western alps (nw italy). m. gabriella forno 1, 2, marco gattiglio 1, franco gianotti 1, sandro rossato 4, glenda taddia 3 1dipartimento di scienze della terra, università di torino, torino, italy. 2 natrisk interdipartimental centre, università di torino, grugliasco (to), italy. 3 dipartimento di ingegneria dell'ambiente, del territorio e delle infrastrutture, politecnico of torino, torino, italy. 4 dipartimento di geoscienze, università di padova, padova, italy. corresponding author: m.g. forno <gabriella.forno@unito.it> abstract: deep-seated gravitational slope deformations (dsgsds) are well-known to affect the landscape and the morphology of alpine valleys. in contrast, little is known on their influence on quaternary deposits. this paper, focused on the western italian alps, aims to fill this gap. eight case studies, identified after a long term field experience, are presented, representative of different geological settings. to fully define their distinctive features, such sites have been characterized using various methods: geological surveys, geophysics and geomatic techniques. dsgsd proved to influence the sediment deposition primarily with the continuous supply of centimetric/decimetric angular clasts. this have different consequences on sediments, depending on their features, in some cases deeply modifying their typical facies (i.e., glacial, colluvial and lacustrine sediments), whilst in other cases their influence is less evident (i.e., debris, avalanche and torrential deposits). this paper can be a useful tool when dealing with dsgsd-related deposits, helping avoid misinterpretations. keywords: sedimentological features, quaternary sediments, deep-seated gravitational slope deformation, western alps. � available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 33 (1), 2020, 43-60 1. introduction field sedimentological observations are a valuable tool that can be used to infer the genesis, depositional environment and stratigraphic setting of a sedimentary body (catuneanu et al., 2009; jaboyedoff et al., 2013; shea et al., 2008). the correct identification of facies is of utmost importance and constitutes a basic criterion for geological mapping. the experience gained during numerous geological mapping projects and field survey campaigns performed in the western alps suggests that quaternary sediments located in mountain regions that have been affected by deep-seated gravitational slope deformation (dsgsd) are often atypical, meaning that their sedimentological features can be peculiar and different from those of sediments outside areas of dsgsd (bollati et al., 2019; coviello et al., 2015; polino et al., 2015). although these differences can be significant, the influence of dsgsd on the sedimentological features of sediments has not been previously well investigated. this paper aims to evaluate the influence of dsgsd on the characteristics of quaternary sediments recognized in the field (glacial, torrential, debris, lacustrine, colluvial, avalanche deposits), omitting the landslide sediments already treated by other studies (ostermann et al., 2016). the diagnostic features of various quaternary sediments observed in mountain dsgsd sectors are compared with those found outside areas of dsgsd (see tab. 1). the features described for each facies are those where the deposit developed entirely in dsgsd areas and were therefore essentially influenced by gravitational processes. in contrast, the cases in which the quaternary succession is fed by a wider catchment basin partly outside dsgsd areas and is related to the overall conditions of the basin (lithology, structure, morphology) are not considered here. this research on the dsgsd quaternary cover is based on a field survey of eight case studies, each of which shows a high number of outcrops (up to several hundred). these case studies derived from areas of the western alps characterized by different geological settings (see section 3), comprising the dora baltea valley (la saxe, la salle, fallére southern slope and scalaro basin), the dora riparia valley (bardonecchia and moncellier), and the chisone valley (fenestrelle and rodoretto basin) (fig. 1). the term dsgsd refers to mass movements involving large volumes of rocks, possibly affecting areas larger than 10 km2, that encompass entire valley flanks and are propagated at very low velocities (mm/year) (agliardi et al., 2012; dramis & sorriso-valvo, 1994; radbruch-hall et al., 1976). these moving masses, which are characterized by a minimum thickness of 100 m and are up to several kilometres long (alberto et al., 2008; ambrosi & crosta, 2006; carraro et al., 1979; kojan & hutchinson, 1978; radbruch-hall, 1978), devel https://doi.org/10.26382/amq.2020.03 44 forno m.g. et al. op in regions with high relief-energy (agliardi et al., 2001; agliardi et al., 2009; agliardi et al., 2012). slope deformation usually started during the lateglacial triggered by post-glacial debutressing following the withdrawal of the glaciers and evolved during the holocene (agliardi et al., 2009). the displacement of a dsgsd is small compared to its extent (massironi et al., 2003) and its rate is usually around 4-5 mm/y (agliardi et al., 2001; coquin et al., 2015; varnes et al., 1990). these long-lasting slope deformations have modified glacially-sculpted relief, also reducing slope inclinations, and have significantly contributed to the long-term denudation of active orogens (agliardi et al., 2013). the slope deformation has been linked to the interactions among glacially oversteepened valley flanks, weaknesses in the rock mass, such as schistosity, fractures, faults and high slope values (agliardi et al., 2009; agliardi et al., 2013; crosta, 1996; massironi et al., 2003; morelli et al., 2018; radbruch-hall, 1978; zorzi et al., 2014). clearly-defined failure planes/zones are not necessary for a dsgsd to develop (dramis & sorrisovalvo, 1994), and the lateral margins of these phenomena are often poorly defined (agliardi et al., 2013). a dsgsd will result in the formation of multiple fractures that progressively dilate, inducing very fractured rock volumes and their dislocation. numerous gravitational morpho-structures, such as double ridges, scarps, counterscarps and open trenches, are essentially connected to gravity, although previous tectonic fractures and faults are often reactivated (agliardi et al., 2001; agliardi et al., 2009; forcella & orombelli, 1984). minor landslides may occur inside the deformed rocky mass, especially in its marginal sectors. the toes of many dsgsds lie below the present valley floors, where they are covered by alluvial or lacustrine fills (agliardi et al., 2012). such phenomena are common in mountain belts and have been extensively studied in recent decades (crosta et al., 2013; massironi et al., 2010; ostermann & sanders, 2017). some considerations regarding dsgsd areas also derive from research aimed at the hydrogeological reconstruction of large volumes of unstable intensely fractured and loosened rocks (binet et al., 2009). however, while various studies have focused on the genetic mechanism of dsgsds and the influence on the bedrock and valley flank morphology, the impact on the features of quaternary sediment assemblages has been poorly investigated. the interactions between dsgsd processes and the facies of quaternary sediments in alpine environments have potential relevance in accurate, large scale field geological surveys. this research exclusively considers the sediments of areas already involved in gravitational processes prior to the deposition of quaternary bodies, as their sedimentological features can be influenced by dsgsds. this research intends to contribute to the definition of some guidelines for the field identification, interpretation and mapping of quaternary successions in dsgsd, although taking into consideration the influence of local geological and geomorphological conditions in different areas of the alps. 2. materials and methods the study areas were investigated through detailed geological surveys (1:10,000 or 1:5,000 scale), allowing us to define the sedimentological features of the quaternary sediments recognized in the field. the features of the quaternary successions in different contexts along the western alps (inside and outside dsgsd) were described using the method by baggio et al. (1997). the use of this method is finalized to have rigorous criteria and is also used by the recent piedmont 1:50,000 scale official maps of italy. clasts are described in this paper in terms of their volume, rather than the commonly used mean diameter (e.g., the udden-wentworth grain-size scale; udden, 1914; wentworth, 1922; 1935). the study areas are characterized essentially by schistose lithotypes, that usually form tabular clasts, with a side remarkably smaller than the others. being so, the volume allows to better evaluate the clast grain size without introducing additional terms to describe the clast shape, as suggested by other authors (e.g., terry & goff, 2014). where no significant outcrops were present, geophysical methods, such as combined electric resistivity tomographies (ert), were applied, focusing in particular on the reconstruction of the shallow subsoil, helping to estimate the distribution and thickness of sediments (comina et al., 2015) (see case study 4). aerial photos helped us describe the morphology of dsgsd sectors; these were particularly useful for obtaining an overall view and for examining sectors that were difficult to access. topographic surveys were performed using "unmanned aerial vehicles" (uavs). this tool allowed us to obtain detailed aerial photos of the landscape and to create various types of maps (digital surface models, digital terrain models with 4 cm of resolution and orthophotos) which also provided evidence of the morphological features of quaternary sedimentary bodies in dsgsd areas (piras et al., 2017) (see case study 8). 3. geological setting of case studies the western alps (nw italy) were built during the alpine orogeny. the original rocks formed in oceanic and continental margin environments and now crop out as deeply deformed and metamorphosed rocks. the investigated case studies are located in different valleys of the western alps with various geological settings, which have already been examined by detailed geological surveys (fig. 1). these valleys were deeply carved by glaciers during the last glacial maximum (lgm) and were partly affected by extensive dsgsd phenomena widespread in the alps (agliardi et al., 2009; forno et al., 2013a; 2013b) and other mountain areas (coquin et al., 2015). the quaternary successions in the study areas are essentially fed by metamorphic bedrock consisting of schistose lithotypes, with prevailing calcschist and subordinate micaschist, greenschist and gneiss. in detail, case study 1 (la saxe) regards the phyllite of the ultrahelvetic domain and the gneiss of the mont chetif tectonic slice, which involves brittle deformed rocks ar 45 dgpv effects on quaternary sediments ranged along the penninic frontal thrust (elter, 1987). case study 2 (la salle) concerns an upper carboniferous succession consisting of coal-bearing slate and meta-clastic sediments. here, the effects of gravitational deformation on tributary torrential sedimentation were investigated by polino et al. (2015). case studies 3, 5, 7, and 8 (fallére southern slope, bardonecchia, fenestrelle and germanasca valley) are developed in prevalent calcschist, with minor bodies of mafic and ultramafic rocks (e.g., meta-peridotite, serpentinite, meta-gabbro, and green-schist) strongly deformed along the regional schistosity and referred to the ophiolitic combin-like units of the upper piedmont zone (polino et al., 2015). we focused on the becca france ridge (fallére southern slope, case study 3) where numerous landforms related to dsgsd (i.e., doubled ridges, minor scarps and trenches) were among the predisposing factors of a large historical rock avalanche, dating back to 1564 ad (forno et al., 2012a). the same dsgsd has also been described in the surrounding plan di modzon area (forno et al., 2013a), where the presence of gravitational trenches and the evolution of minor scarps on lacustrine and palustrine sedimentation have been detected by geophysical approaches (comina et al., 2015). some geological information is also reported for the susa valley (bardonecchia, case study 5), where a significant spring is fed by strongly fractured bedrock (calcschist) (de luca et al., 2015). a dsgsd in the chisone valley (fenestrelle, case study 7) is reported as a predisposing factor for the occurrence of thick landslides that hindered the t. chisone flow (carraro & forno, 1981; fioraso & baggio, 2013). dsgsd phenomena were also well investigated in a chisone valley tributary (germanasca valley), also using geomatics techniques, highlighting numerous gravitational morpho-structures that split the glacial sediment bodies, which resulted in numerous isolated flaps (forno et al., 2011; forno et al., 2012b; piras et al., 2017) (case study 8). case study 4 (renanchio basin) is located in eclogite micaschist and gneiss with minor bodies of marble, calcschist and mafic rocks referred to as austroalpine units (sesia-lanzo zone). this area, which is strongly influenced by both dsgsds and the glacial and torrential evolution of the lateral renanchio valley, is significant for the interconnection between gravitational deformation and hydrogeological setting. specifically, a spring with high water discharge (average 160 ls-1) located in the area is supplied by groundwater hosted in the loosened bedrock linked to this deformation (de luca et al., 2015; de luca et al., 2019; lasagna et al., 2013). finally, case study 6 (moncellier) includes micaschist with some meta-conglomeratic levels of the ambin complex in the ambin massif (grand saint bernard nappe). the springs, as in previous cases, have been regarded as connected to an aquifer hosted by the fractured and loosened rocks of a dsgsd (de luca et al., 2009). 4. results 4.1. influences of dsgsds on subglacial sediments a significant example of subglacial sediments (lodgement till) in a dsgsd area is visible on the western slope of the germanasca valley, e of the balma village along the t. rodoretto tributary (case study 8) (a in fig. 2). the outcrop is approximately 70 m wide and 10 m high and does not reach the bedrock (fig. 3a). the top of the outcrop has a regular surface, representfig. 1 the investigated areas are located in the western alps (nw italy) and refer to different geological contexts. case studies (1) la saxe, (2) la salle, (3) fallére southern slope and (4) renanchio basin are located in the dora baltea valley. case studies (5) bardonecchia and (6) moncellier are located in the dora riparia valley. case studies (7) fenestrelle and (8) tributary germanasca valley are located in the chisone valley. ing the side of the glacial valley. these sediments are formed by tabular clasts of various sizes mixed in a subordinate unsorted matrix (fig. 3b). the decimetric clasts (10 cm3-0,5 m3) are numerous in the whole outcrop, while boulders of great size (essentially 0,5-3 m3) are few and more abundant in the lower band of the outcrop, where rare boulders, with up to a 70 m3 volume, are also observed (fig. 3d). the clasts have poor roundness: the centimetric fragments are angular, while the decimetric and metric boulders are from subangular to subrounded. the fragments and boulders show a preferential dip of 30-35°, according to the slope of the glacial valley (fig. 3c). the petrographic composition of the clasts is very monotonous, essentially comprising calcschist (phyllitic and carbonate) with subordinate prasinite, basaltic metabreccia, quartzite and rare marble, according to the local bedrock fed by the high rodoretto valley. some clasts preserve carbonate patinas suggesting poor cementation of sediments. the matrix, which is variably present (10-20%), is mostly subordinate to the clasts, but enough to determine the matrix-supported texture, responsible for the poor permeability (fig. 3e). the matrix essentially consists of very abundant millimetric to centimetric rock fragments (� 10 cm3) with subordinate fine sand and silt. these sediments show high consolidation. the unweathered clasts and matrix (grey colour) and location in the valley floor can agree with the reference to the last glaciation. another example of subglacial sediments in the dsgsd context is visible near saint nicolas village along the gaboè valley, a northern tributary of the dora baltea river, filled by a thick sedimentary succession (case study 3) (b in fig. 4). this gaboè stretch appears entrenched in a previous incision of the dora baltea glacier (fig. 5a). evident badlands on the southern slope allow us to observe a 700 m-wide and 30-35 m-high outcrop, showing a succession of glaciolacustrine (gl, 10 m of visible thickness), subglacial (lodgement till) (sg, 15-18 m thick) and cemented ice-marginal sediments (im, 6 m thick) (fig. 5 b and c). the subglacial sediments are dominated by abundant clasts mixed in a poor matrix (fig. 5d). the body consists of decimetric thick layers of massive sediments, variably inclined 10-30° towards the se (fig. 5c). groups of strata with little difference in orientation and dip are visible, separated by unconformable low to midangle erosional surfaces. the clasts have various sizes mostly comprising centimetric (� 10 cm3) and decimetric fragments (10 cm3-0,5 m3), with rare boulders (up to 1 m3), locally concentrated in the low band of sediments (fig. 5b). the clasts are essentially angular with very subordinate subrounded shapes (fig. 5e). the petrographic composition of the clasts is monotonous, formed by prevailing calcschist with subordinate quartzite. the matrix, which is variably present (10-20%), is mainly formed of millimetric to centimetric rock fragments (� 10 cm3) with a lower silty component and appears subordinate to clasts (fig. 5d). these matrixsupported sediments mostly show high consolidation and not appear cemented, despite the occurrence of surficial carbonate patinas, supplied by the overlying cemented ice-marginal sediments. the prevailing grey colour and the unweathered clasts agree with the refer 46 fig. 2 topographic map of case study 8, in the germanasca valley. location of the examples reported in the text: subglacial sediments (a) and ice-marginal sediments (b). the yellow dotted line marks the edge of the investigated dsgsd area. forno m.g. et al. ence to the last glaciation. the uncommon features of the subglacial sediments in the investigated dsgsd areas can be evaluated comparing them with their analogues outside dsgsd areas, which are characterized by a strong predominance of the sandy-silty matrix (tab. 1). only locally, under some conditions (slightly weathered bedrock with a large amount of available debris for tectonic fracturing), could the matrix be poor. the clasts are 47 normally very subordinate and plunged in the matrix with faceted shapes and are subangular to subrounded. the petrographic composition of the clasts is usually representative of the entire basin, except for the bottom which can be enriched by the local bedrock. typical pebbles (i.e., faceted, polished and striated pebbles) are also common. these sediments are normally overconsolidated due to ice loading (goldthwait & matsch, 1988). fig. 3 outcrop of subglacial sediments (lodgement till) e of balma village (case study 8). a) panoramic view of the outcrop seen from the east: the regular morphology of the original preserved glacial slope is evident at the top of the sediments (slope of 26°). b) the sediments are formed by clasts of various sizes mixed to in a poor matrix. c) the clasts have a poor roundness and show a preferential arrangement according to the glacial slope. d) boulders of great size (volume up to 70 m3) are relatively abundant in the lower band of the outcrop. e) detail of the outcrop in which the relationship matrix/clasts is observed. dgpv effects on quaternary sediments in contrast, the subglacial sediments (lodgement till) in the investigated dsgsd case studies usually show significantly less matrix (fig. 5e), a greater abundance of various size clasts (fig. 3d) and essentially angular clasts with the absence of faceted, polished and striated pebbles. moreover, the clasts show a local and monotonous petrographic composition derived from the bedrock involved in dsgsd phenomena. the typical overconsolidation of subglacial sediments outside dsgsd areas is also less evident in dsgsd areas caused by the scarcity of the sandy-silt matrix. the prevalence of a coarse fraction in the matrix also leads to a greater permeability and consequent local carbonate cementation (fig. 5d). the peculiar features of the described subglacial sediments located in the fallére southern slope (case study 3) (fig. 5), referred to the late lgm, were already described as characterized by the prevailing presence of angular clasts made of local lithotypes (calcschist and marble) with abundant sandy-gravelly matrix. subrounded allochthonous clasts are also present, but in lesser amount than usual glacial sediments (polino et al., 2015 colle san carlo subsynthem). 4.2. influences of dsgsds on ice-marginal and supraglacial sediments an exemplificative and well-exposed outcrop of icemarginal and supraglacial sediments is located on the western slope of the germanasca valley, approximately 700 m sse of bergeria balma along the t. rodoretto tributary (case study 8) (b in fig. 2). this outcrop is approximately 25 m wide and 30 m high (fig. 6a), reaching the bedrock in its southern sector allowing to evaluate the overall thickness of these sediments of approximately 30 m and covered by colluvium in the lower band (fig. 6b). these sediments crop out in the internal flank of the frontal-lateral sector of a right moraine. the ice-marginal sediments are essentially formed by centimetric to decimetric clasts (the clast size essentially varies between 5 cm3 to some dm3) mixed in a sandy-silty matrix (tab. 1) (fig. 6c). the sediments also contain rare boulders up to 1 m3 in size. the clasts display subangular to angular shapes (fig. 6c) and have a monotonous petrographic composition exclusively 48 fig. 4 topographic map of case study 3, located on the northern slope of the aosta valley in the p. leysser dsgsd. locations of the examples reported in the text: lacustrine sediments (a), subglacial sediments (b), debris (c), avalanche sediments (d) and colluvial (e). the yellow dotted line marks the edge of the investigated dsgsd area. forno m.g. et al. colour and the unweathered clasts also suggest a reference to the last glaciation. the uncommon features of the ice-marginal and supraglacial sediments in the investigated dsgsd areas can be evidenced by comparing them with the same sediments outside dsgsd areas. these last areas typically have abundant large and giant boulders of various petrographic compositions (dreimanis, 1988; goldthwait & matsch, 1988), although a remarkable formed by calcschist and subordinate marble, representative of the local bedrock. numerous clasts show arrangement towards the e (fig. 6d), defining inclined bedding according to a right lateral moraine. the poor matrix (essentially ranging from 10% and 20%) is unsorted and rich in millimetric rock fragments with a very subordinate silty component (fig. 6e). the sediments essentially have a matrix-supported texture and are normally consolidated and weakly cemented. the grey 49 fig. 5 glacial succession in the gaboè valley, sw saint nicolas (case study 3). a) the gaboè valley seen from the nw, characterized by evident badlands, entrenched in a dora baltea glacial valley floor (green valley). b) succession of subglacial (lodgement till) (sg, dark grey) and cemented ice-marginal (im, yellow-grey) sediments; the regular morphology of a moraine is evident at the top of the sediments. c) succession of well-stratified glaciolacustrine (gl) and overlying massive to stratified subglacial sediments (sg). d) subglacial sediments formed by prevailing small subangular clasts mixed in a poor matrix. e) details of the clast-rich subglacial sediments. dgpv effects on quaternary sediments local fraction can occur. such boulders are defined as “erratic” and are essentially different than the local bedrock, possibly deriving from remote regions. moreover, these sediments are also characterized by a large amount of sandy-silty matrix, often prevailing. in contrast, the ice-marginal and supraglacial sediments in the dsgsd case studies show a scarcity of large boulders (fig. 6a) caused by the extreme fracturing of the bedrock and a great abundance of millimetriccentimetric clasts. the petrographic composition, which is mainly local, represents another difference with analogous sediments outside dsgsd areas that can also contain many clasts of various lithotypes. the scarcity of matrix favours a carbonate cementation, which increases the differences with the ice-marginal and supraglacial facies outside dsgsd areas. 50 carbonate fluids circulating in the ice-marginal sediments are recognized to promote their cementation and even deposition of travertine. such fluids are common in dsgsd areas characterized by the presence of deeply fractured carbonate bedrock. as an example, the fallére southern slope (case study 3) is characterized by a great concentration of travertine (polino et al., 2015; forno et al., 2016). 4.3. influences of dsgsds on torrential sediments the best outcrop of torrential sediments is on the northern slope of the aosta valley, along the dora baltea fluvial incision into the wide la salle fan (case study 2) (fig. 7a). this outcrop, approximately 200 m wide and 30 m high, is covered by colluvium in the lower band. the typical flat morphology of a large alluvial fan, fig. 6 outcrop of the ice-marginal sediments sse of bergeria balma (case study 8). a) panoramic view of the outcrop seen from the west: the morphology of a moraine is evident at the top of the sediments (white arrows indicate the moraine ridge). b) the upper part of the outcrop shows ice-marginal sediments (im) lying on the bedrock (bd), while these sediments are covered by colluvium in the lower band (c). c) angular shape and arrangement of most clasts towards the east (right). d) details of the abundant clasts. e) poor amount of matrix. forno m.g. et al. despite being supplied by the small d'echarlod basin, develops at the top of sediments (fig. 7a). the torrential sediments are essentially formed by centimetric to decimetric clasts (the clast size varies between 5 cm3 to some dm3) mixed to an abundant matrix (tab. 1) (fig. 7b). the clasts have subangular shapes with smooth edges (fig. 7b) and a petrographic composition exclusively formed by gneiss, grey marble, micaschist, graphitic schist and quartzite, representative of the catchment basin bedrock. the clasts define an inverse graded bedding (fig. 7c), despite not being evident, suggesting an environment also fed by debrisflow phenomena. the relatively abundant matrix, essentially ranging from 20% to 30%, is partly formed by millimetric rock clasts with a subordinate unsorted sandy component. the dark grey colour of the matrix is essentially due to the remarkable graphitic schist component (fig. 7c). these sediments essentially have a matrixsupported texture, appearing normally consolidated and weakly cemented. the peculiar features of the torrential sediments in the investigated dsgsd areas can be highlighted by comparing them with torrential sediments outside dsgsd areas, which usually have abundant rounded to subrounded pebbles and cobbles, centimetric to decimetric in size, mixed in a poor sorted, sandy matrix defining a clast-supported texture (thorne et al., 1987). moreover, the torrential sediments show evident cross bedding with local imbricate clasts. in contrast, the torrential sediments in the dsgsd case studies show a scarcity of rounded pebbles and cobbles (fig. 7b). these sediments are characterized by relatively few sub-angular decimetric clasts, a great abundance of millimetric-centimetric angular clasts and sandy matrix, which also favour carbonate cementation. the scarcity of coarse-grained clasts determines the lack of evident bedding and the texture between clastsupported and matrix-supported. 4.4. influences of dsgsds on debris (scree) the debris in the dsgsd investigated case studies shows some differences compared to the debris outside dsgsd areas. an approximately 300 m wide and 100 m high outcrop of these sediments (fig. 8a) is located on 51 fig. 7 outcrop of the torrential sediments s of la salle village (case study 2). a) morphology of the wide la salle alluvial fan, supplied by a small basin (a), view seen from the sw (outcrop indicated by the white arrow). the yellow dotted line marks the edge of the dsgsd area. b) subangular shape of most clasts forming torrential sediments mixed in an abundant matrix. c) details of the not very evident inverse graded bedding. dgpv effects on quaternary sediments the northern slope of the aosta valley along the t. verrogne tributary, 2 km nw of verrogne village (case study 3) (c in fig. 4). the topographic surface at the top of the outcrop shows a regular sw-sloping morphology, according to a talus slope (fig. 8b). the outcropping debris is formed by centimetric clasts, with rare decimetric elements (tab. 1) (fig. 8c). the clasts and millimetric fragments are angular and essentially display an irregular tabular shape and have a monotonous petrographic composition, formed by prevailing calcschist with rare quartzite, strictly depending on the composition of the upper slope. the debris is characterized by an open texture and structures ranging from a massive to an inclined bedding and appears unconsolidated and locally cemented. the large calcschist component determines the grey colour of the sediments. the increasing of potential debris and small rockfalls also highlighted in the cenischia valley, especially in the uppermost sectors of the catchments, was connected to the presence of well-developed dsgsd resulted in producing debris and torrential deposits up to dozens of meter thick (coviello et al., 2015). the debris in the investigated dsgsd areas is usually formed by centimetric clasts, whereas outside dsgsd areas, debris is usually decimetric in size (tab. 1). 4.5. influences of dsgsds on lacustrine sediments a significant outcrop of lacustrine sediments in the dsgsd areas is located on the northern slope of the aosta valley, 150 m se of avise village, at the confluence between the dora baltea incision and its northern tributary (gaboè r.) (case study 3) (a in fig. 4). this outcrop is exposed in the deep incision due to the current hydrographic network (dora riparia and gaboè rivers), with a depth of approximately 45 m (fig. 9b). the top of the outcrop shows s-sloping flat morphology entrenched in the gaboè r. incision, suggesting a torrential fan of this watercourse (fig. 9a). this outcrop, approximately 40 m high and 200 m long, allows the observation of a succession of three overlapping sedimentary bodies, a glaciolacustrine body (27 m of visible thickness), a lacustrine body (5 m thick) and an alluvial body (6 m thick) (fig. 9b). the lower and the upper bodies contain clasts of various petrographic compositions (comprising the monte bianco granite) referred to the dora baltea valley (interpreted as directly supplied by the dora baltea valley for the lower body and as reworked glacial dora baltea sediments for the upper body) and therefore are essentially not connected with dsgsd areas. the intermediate body is, on the contrary, rich in local clasts, suggesting an exclusively local supply by the gaboè basin, developed into the p. leysser dsgsd. therefore, it can be used as an example of lacustrine sediments supplied by a dsgsd area. the lacustrine body has a basal surface consisting of a weakly n-dipping concave erosional surface, with a counter-slope trend (fig. 9d). these sediments are formed by centimetric to decimetric clasts (the size essentially varies between a few cm3 to a few dm3) mixed in an abundant unsorted matrix, mainly comprising millimetric angular tabular rock fragments and a poor sandysilty component (tab. 1) (fig. 9c). the clasts essentially are subangular to subrounded (fig. 9e) and have a monotonous petrographic composition, formed by prevail 52 fig. 8 outcrop of the debris nw of verrogne village (case study 3). a) panoramic view of the slope seen from the south. b) morphology of the slope at the top of the sediments, consisting of a debris talus, seen from the west. c) angular tabular shape of centimetric clasts forming the debris. forno m.g. et al. 53 ing calcschist with rare prasinite and quartzite, representative of the local bedrock of the gaboè basin. these sediments have matrix-supported texture and bedding weakly inclined towards the south, according to a foreset body deposited in a lacustrine environment, defined by alternating clast-rich and matrix-rich levels. the sediments also appear normally consolidated and have a dark grey colour, resulting from the large calcschist component (fig. 9e). the uncommon features of the lacustrine sediments in the investigated dsgsd areas can be evidenced by comparing them with the same sediments outside dsgsd areas that are usually fine-grained and frequently have a sandy-silty texture, as well as a more varied petrographic composition and high roundness of clasts. in contrast, the lacustrine sediments in the dsgsd case studies are essentially gravel with a great abundance of millimetric angular tabular rock fragments and various amounts of sandy-silty matrix. 4.6. influences of dsgsds on colluvial sediments a valuable outcrop of colluvial sediments, approximately 50 m wide and 3 m high (along an erosional scarp), is located on the northern slope of the aosta valley along the t. verrogne tributary, 2 km nw of verfig. 9 outcrop of the lacustrine sediments 150 m se of avise village (case study 3). a) the top of succession, seen from the west, shows an alluvial fan typical morphology (arrow indicates the outcrop). b) a succession, seen from the south, of dora baltea glaciolacustrine (dgl), gaboè r. lacustrine (gl) and alluvial (ga) bodies. c) details of the sedimentary succession. d) basal surface of lacustrine sediments (gl). e) relatively coarse-grained facies of the gaboè lacustrine sediments formed by angular clasts mixed in a sandy matrix of dark grey colour. dgpv effects on quaternary sediments 54 rogne village (case study 3) (e in fig. 4). the top of the outcrop, which is characterized by a brown cover of other colluvial sediments, likely reworked glacial sediments, shows a regular s-sloping morphology (fig. 10a). the outcropping colluvial sediments, at least 2-3 m thick (fig. 10b), are formed by small clasts mixed in a matrix rich in millimetric rock fragments (tab. 1) (fig. 10c). the clasts, essentially centimetric in size with rare decimetric elements, and millimetric fragments of the matrix are angular and have an irregular tabular shape. the clasts and fragments have a monotonous petrographic composition, with prevailing calcschist and rare quartzite, strictly depending on the lithology of the upper slope. the colluvial sediments are characterized by a clastto matrix-supported texture and structures ranging from massive to inclined bedding according to the slope. the sediments appear unconsolidated, locally cemented and of grey colour connected to their petrographic composition. the colluvial sediments in the investigated dsgsd areas have partly uncommon features with respect to the same sediments outside dsgsd areas, which usually consist of sand, slightly gravelly and silty, with rare clasts and evident matrix-supported textures. in contrast, the colluvial sediments in the dsgsd case studies are silty sandy gravel formed by prevailing centimetric angular clasts of local petrography. the poor unsorted matrix (mainly formed by angular tabular millimetric fragments) is responsible for the various textures, i.e., matrix or clast-supported. 4.7. influences of dsgsds on avalanche sediments a well-exposed outcrop of avalanche sediments (fig 11a) is located on the northern slope of the aosta valley, 3 km nnw of the sarre village, along the upstream scarp of a mountain pasture road in the tributary clusellaz valley (case study 3) (d in fig. 4). the topographic surface at the top of the outcrop shows a regular sw-sloping morphology, according to a t. clusellaz avalanche fan (fig. 11a). this outcrop, which is approximately 12 m high and 60 m long, allows the observation of a succession of two sedimentary bodies, a low subglacial (5 m of visible thickness) and an upper avalanche body (7 m thick) (fig. 11b). in detail, the lower body contains clasts of a various petrographic compositions referred to the dora baltea valley and is therefore essentially not connected with dsgsd areas. the upper body is, on the contrary, rich in local clasts, suggesting an exclusive supply by the clusellaz basin developed into the p. leysser dsgsd, and it can be used as an example of avalanche sediments supplied by a dsgsd area. the avalanche body has a basal surface consisting of a convex surface in the cross-section, visible along the road scarp, connected with a previous ridge shaped in the subglacial sediments (fig. 11b). the avalanche sediments are formed by centimetric to decimetric clasts (the clast size essentially varies between some cm3 to some dm3) mixed in a poor unsorted matrix, essentially formed by millimetric angular tabular rock fragments and a scarce sandy-silty component (tab. 1) (fig. 11b). the clasts essentially have angular to subangular shapes fig. 10 outcrop of the colluvial sediments nw of the verrogne village (case study 3). a) view of the outcrop (arrow) seen from the east and morphology of the slope at the top of the sediments. b) facies of the grey investigated colluvial sediments and of the brown colluvial sediments deriving from reworking of glacial sediments. c) details of angular tabular centimetric clasts mixed in a subordinate matrix. forno m.g. et al. 55 (fig. 11c) and a monotonous petrographic composition (prevailing calcschist and prasinite with rare quartzite and cellular dolomite) representative of the local bedrock outcropping on the upper slope. these sediments have a clast-supported texture and 20° sw dipping bedding, according to the fan surface and defining a body deposited in an avalanche environment. the sediments, which have a grey colour, also appear normally consolidated and weakly cemented. the partly uncommon features of the avalanche sediments in the investigated dsgsd areas can be evaluated by comparing them with the avalanche sediments outside dsgsd areas, which are usually matrixrich with subordinate clasts, defining a matrix-supported texture. in contrast, the avalanche sediments in the dsgsd case studies consist of centimetric up to decimetric angular clasts of local lithotypes with a poor matrix containing millimetric angular tabular rock fragments, forming a clast-supported texture (jomelli & francou, 2000; luckman et al., 1977; matthews et al., 2011). 5. discussion the various facies observed in the investigated dsgsd cases show sedimentological features that are partly very different and partly common to those outside dsgsd areas regarding the grain size, clast shape and roundness, clast abundance and petrographic composition and the amount and texture of the matrix (tab. 1). regarding the anomalous features in the investigated case studies, the subglacial facies is characterized by the great abundance of small subangular to angular clasts mixed in a matrix mainly formed by millimetric rock fragments, resulting in a coarse-grained texture. this lithofacies is very different compared to that of traditional subglacial sediments (outside dsgsd areas), which are characterized by an essentially fine texture, with a prevailing fine sandy-silty matrix, and subrounded, smoothed, polished and striated pebbles. additionally, the ice-marginal sediments have a peculiar texture in the investigated case studies with an abundance of millimetric to metric fragments, scarcity of fine sand and silt in the matrix and absence or rareness of large boulders (larger than metric in size). these characteristics are unusual compared to those of traditional ice-marginal sediments outside dsgsd areas, which generally have many large boulders and an abundant fine matrix. the occurrence of many small angular rocky fragments of local lithotypes also characterizes the colluvial, avalanche, lacustrine and debris sediments outcropping in the investigated dsgsd areas, which are partly coarser than traditional sediments (colluvial, avalanche, lacustrine) or finer (debris) than traditional sediments. finally, the prevalence of small angular rock fragments is observed in dsgsd examples both in the cases in which the traditional sediments are usually fine (subglacial and lacustrine sediments) and in the cases in which the sediments usually contain very large boulders (ice-marginal sediments). this look can be the consequence of high bedrock fracturing despite the fractures not being homogenously distributed throughout the whole rock volume, which has both highly fractured and completely loosened sectors (fig. 12). this conclusion applies only for dsgsds that evolved before or at the same time as the deposition of quaternary successions, which are therefore fed by fractured bedrock, while gravitational phenomena that fig. 11 wide outcrop 3 km nnw of sarre village (case study 3). a) succession of subglacial (sg) and avalanche (av) sediments. this last body forms an extended avalanche fan. b) basal surface of avalanche sediments (arrows) that cover a glacial ridge. c) detail of coarse grained facies of the avalanche body visible above the subglacial sediments. dgpv effects on quaternary sediments 56 evolved subsequently do not affect the sedimentary features but only dislocate and deform the geological bodies, influencing their distribution and conservation degree. fracturing and slackening cause a downgrading of the geo-mechanical properties of the bedrock, favouring the high production of angular rock fragments of local lithotypes. the fragments usually have flattened shapes in loosened schistose rocks, which are the prevalent lithotypes in the study area. it should be emphasized that a fractured bedrock is not exclusive to dsgsds and can also derive from a strong tectonization linked to a brittle deformation zone. furthermore, the production of small rock fragments can be favoured by the occurrence of many gravitational morpho-structures, which are mainly represented by steep rock walls along minor scarps and elongated depressions corresponding to trenches. these slope irregularities favour their strong erosion by various exogenous agents. the removal of bedrock fragments is essentially due to glaciers, during glacial phases, and to watercourses, running water, snow avalanches and gravity during the post-glacial period. moreover, the morphological renewal of these walls, linked to the progressive reactivation of morpho-structures, further increases the availability of centimetric rock fragments. another significant feature of the sediments in the studied dsgsd areas is the monotonous petrographic composition of most of the clasts caused by a prevailing local supply. this composition differs especially for glacial sediments with respect to that of traditional facies (outside dsgsd areas), which are usually rich in various lithotypes representative of the entire glacial basin, although the local component can sometimes be significant for ice-marginal sediments or near the bottom for subglacial sediments. however, if the glacier or the watercourse has a basin upstream of the dsgsd areas, some subordinate allochthonous clasts can be present. the abundance of rock fragments in the dsgsd examples can also promote high permeability in the sediments and consequent carbonate cementation due to the various contents of caco3 in water, depending on bedrock composition. in contrast, in traditional sediments outside dsgsd areas, carbonate cementation can be hindered by normal abundance of silty matrix. the high fracturing of bedrock in dsgsds produces large sectors with juxtaposed centimetric angular fragments that can be confused with quaternary sediments (fig. 12c). for example, the loosened bedrock can be, at first glance, totally mistaken as debris, despite the absence of a source upstream (fig. 12d). more accurate observations indicate that the foliation inside individual fragments appears prevalently aligned with the regional schistosity and that all fragments have the fig. 12 various fracturing of the bedrock in dsgsd areas. fractured (a, moncellier, case study 6) or completely loosened bedrock (b, or village on the fallére southern slope, case study 3). the fractured bedrock can simulate ice-marginal sediments forming a moraine (c) or debris (d) (western side of the becca france ridge, on the fallére southern slope, dora baltea valley, case study 3). forno m.g. et al. 57 tab. 1 sedimentological features of the different facies of quaternary sediments in the mountain areas. dgpv effects on quaternary sediments same attitude of schistosity. consequently, these fractured patches are directly shaped in the bedrock and can be considered “in situ” (fig. 12c). this research started to solve well-known difficulties in the survey and mapping of quaternary successions in dsgsd areas of the western alps since the uncommon facies of some sediments in these areas can hinder their identification. in detail, recognizing the sediments as such is often hard in this context because the sediments can sometimes be confused with loosened bedrock and it is difficult to distinguish between the different types of sediments. for example, subrounded faceted pebbles formed by allochthon lithotypes, which normally characterize subglacial sediments, do not occur, and consequently, these sediments cannot be recognized and mapped. loosened bedrock or soils or colluvia connected to bedrock weathering/reworking are alternatively reported (for example carraro et al., 2002; polino et al., 2002). consequently, some dsgsd areas seem strangely poor in quaternary sediments, while the extreme fracturing of bedrock should have favoured the deposition of surficial sediments (forno et al., 2016). 6. conclusions this research derives from extensive field experience in the survey of quaternary continental successions in the western alps. some case studies suggest that the quaternary sediments located in dsgsd areas are often unusual and partly different from their analogues in successions outside dsgsd areas. the sediments in the reported examples proved to be strongly enriched in centimetric angular rock fragments, their presence being promoted by the high degree of rock fracturing and the numerous gravitational scarps typical of dsgsd areas. the differences between the sedimentological features observed in the investigated case studies and those outside dsgsd areas vary according to the depositional environment. debris, avalanche and torrential sediments, which are typically made of angular clasts, show almost equal facies both inside and outside dsgsd areas. in contrast, sediments that are normally fine (i.e., subglacial, colluvial and lacustrine deposits) or very coarse (i.e., glacial deposits) show low textural variability inside the dsgsd area, giving rise to a sort of “facies convergence”. this research is based on case studies from the western sector of the alps, where the geological context, climate and morphology are relatively homogeneous. although the presented considerations need to be confirmed in different settings, before extending them to other sectors of the alps or to other mountain ranges, geologists working on quaternary successions in alpine areas should be aware that the facies of deposits located in dsgsd areas can differ from those normally found. this paper can be a useful tool to avoid misinterpretations of these deposits using only sedimentological features, regardless of their morphological expression. acknowledgments we are very grateful to the editor paolo mozzi for the useful suggestions for title, text and figures of the paper. references agliardi f., crosta g.b., zanchi a. (2001) structural constraints on deep-seated slope deformation kinematics. eng. geol., 59(1-2), 83-102. doi: 10.1016/s0013-7952(00)00066-1 agliardi f., crosta g.b., zanchi a., ravazzi c. (2009) onset and timing of deep-seated gravitational slope deformations in the eastern alps, italy. geomorphol., 103, 113-12. doi: 10.1016/j.geomorph.2007.09.015 agliardi f., crosta g.b., frattini p. (2012) slow rockslope deformation. in: clague j.j., stead d. (eds.) landslides types, mechanisms and modeling. cambridge univers. press, 207-221. doi: 10.1017/cbo9780511740367.019 agliardi f., crosta g.b., frattini p., malusà m.g. (2013) giant non-catastrophic landslides and the longterm exhumation of the european alps. earth planet. sci. lett., 365, 263-274. doi: 10.1016/j.epsl.2013.01.030 alberto w., giardino m., martinotti g., tiranti d. (2008) geomorphological hazards related to deep dissolution phenomena in the western italian alps: distribution, assessment and interaction with human activities. eng. geol., 99 (3-4), 147-159. doi: 10.1016/j.enggeo.2007.11.016 ambrosi c., crosta g.b. (2006) large sackung along major tectonic features in the central italian alps. engin. geol., 83, 183-200. doi: 10.1016/j.enggeo.2005.06.031 baggio p., bellino l., carraro f., fioraso g., gianotti f., giardino m. (1997) schede per il rilevamento geologico delle formazioni superficiali. il quaternario, it. journ. quatern. sci., 10(2), 655-680. bollati i.m., masseroli a., mortara g., pelfini m., trombino l. (2019) alpine gullies system evolution: erosion drivers and control factors. two examples from the western italian alps. geomorphology, 327, 248-263. doi: 10.1016/j.geomorph.2018.10.025 binet s., spadini l., bertrand c., guglielmi y., mudry j., scavia c. (2009) variability of the groundwater sulfate concentration in fractured rock slopes: a tool to identify active unstable areas. hydrol. earth sys. sci. discuss., 13(12), 2315-2327. doi: 10.5194/hess-13-2315-2009 carraro f., dramis f., pieruccini u. (1979) large-scale landslides connected with neotectonic activity in the alpine and apennine ranges. proceedings of the 15th meeting “geomorphological survey mapping” modena, italy, 213-230. carraro f., forno m.g. (1981) segnalazione di una "paleofrana" in val chisone presso fenestrelle (prov. di torino). geogr. fis. dinam. quatern., 4, 48-54. carraro f., cadoppi p., baggio p., bellino l., castelletto m., giraud v., mensio l. (2002) foglio 154, “susa”. carta geologica d'italia alla scala 1:50.000. serv. geol. it. ispra. catuneanu o., abreu v., bhattacharya j.p., blum m.d., 58 forno m.g. et al. dalrymple r.w., eriksson p.g., fielding c.r., fisher w.l., galloway w.e., gibling m.r., giles k.a., holbrook j.m., jordan r., kendall c.g.st.c., macurda b., martinsen o.j., miall a.d., neal j.e., nummedal d., pomar l., posamentier h.w., pratt b.r., sarg j.f., shanley k.w., steel r.j., strasser a., tucker m.e., winker c. (2009) towards the standardization of sequence stratigraphy. earthsci. rev., 92 (1-2), 1-33. doi: 10.1016/j.earscirev.2008.10.003 comina c., forno m.g., gattiglio m., gianotti f., raiteri l., sambuelli l. (2015) ert geophysical surveys contributing to the reconstruction of the geological landscape in high mountain prehistorical archaeological sites (plan di modzon, aosta valley, italy). it. j. geosc., 134(1), 95-103. doi: 10.3301/ijg.2014.31 coquin j., mercier d., bourgeois o., cossart e., decaulne a. (2015) gravitational spreading of mountain ridges coeval with late weichselian deglaciation: impact on glacial landscapes in tröllaskagi, northern iceland. quat. sci. rev., 107, 197-213. doi: 10.1016/j.quascirev.2014.10.023 coviello v., arattano m., turconi l. (2015) detecting torrential processes from a distance with a seismic monitoring network. nat hazards, 78, 2055-2080. doi: 10.1007/s11069-015-1819-2 crosta g.b. (1996) landslide, spreading, deep seated gravitational deformation: analysis, examples, problems and proposals. geogr. fis. dinam. quatern., 19(2), 297-313. doi: 10.1016/j.tecto.2013.04.028 crosta g.b., frattini p., agliardi f. (2013) deep seated gravitational slope deformations in the european alps. tectonophys, 605, 13-33. doi: 10.1016/j.tecto.2013.04.028 de luca d., cerino e., forno m.g., gattiglio m., gianotti f., lasagna, m. (2019) the montellina spring as example of water circulation in alpine dsgsd context (nw italy). water, 11(4), 700. doi: 10.3390/w11040700 de luca d.a., destefanis e., forno m.g., fratianni s., gattiglio m., masciocco l., menegon a. (2009) studio interdisciplinare per il monitoraggio e la valorizzazione delle sorgenti della valle di susa in previsione di opere a forte impatto ambientale. convegno nazionale aigeo: ambiente geomorfologico e attività dell’uomo: risorse, rischi, impatti. torino 28-30 marzo 2007. mem. soc. geogr. it., 87(i-ii), 189-199. de luca d.a., masciocco l., caviglia c., destefanis e., forno m.g., fratianni s., gattiglio m., lasagna m., gianotti f., latagliata v., massazza g. (2015) distribution, discharge, geological and physicalchemical features of the springs in the turin province (piedmont, nw italy). in: lollino g., arattano m., rinaldi m., giustolisi o., marechal j.c., grant g.e. (eds.) engineering geology for society and territory, switzerland, 3, 253-256. doi: 10.1007/978-3-319-09054-2_52 dramis f., sorriso-valvo m. (1994) deep-seated gravitational slope deformations, related landslides and tectonics. engin. geol., 38, 231-243. dreimanis a. (1988) tills, their genetic terminology and classification. in: goldthwait r.p., matsch c.l. (eds.) genetic classification of glacigenic deposits. balkema, rotterdam, pp. 17-83. elter g. (1987) carte géologique de la vallée d’aoste, échelle 1:100.000. c.n.r. centro studi sui problemi dell’orogeno delle alpi occidentali. edizioni s.e.l.c.a., firenze, italy. fioraso g., baggio p. (2013) geological map of the mount ciantiplagna rock avalanche (chisone valley, italian western alps). j. maps, 9(3), 336-342. doi: 10.1080/17445647.2013.781967 forcella f., orombelli g. (1984) holocene slope deformations in valfurva, central alps, italy. geogr. fis. dinam. quat., 7(2), 41-48. forno m.g., lingua a., lo russo s., taddia g. (2011) improving digital tools for quaternary field survey: a case study of the rodoretto valley (nw italy). envir. earth sci., 64, 1487-1495. doi: 10.1007/s12665-011-0971-6 forno m.g., gattiglio m., gianotti f. (2012a) geological context of the becca france historical landslide (aosta valley, nw italy). alp. mediterr. quatern., 25(2), 125-139. doi: 10.1007/s12665-011-0971-6 forno m.g., lingua a., lo russo s., taddia g. (2012b) morphological features of rodoretto valley deepseated gravitational slope deformations. am. j. envir. sci., 8(6), 648-660. doi: 10.3844/ajessp.2012.648.660 forno m.g., gattiglio m., gianotti f., guerreschi a., raiteri l. (2013a) deep-seated gravitational slope deformations as possible suitable locations for prehistoric human settlements: an example from the italian western alps. quatern. intern., 303, 180-190. doi: 10.1016/j.quaint.2013.03.033 forno m.g., lingua a., lo russo s., taddia g., piras m. (2013b) gstop: a new tool for in field recording of 3d geological data. europ. journ. rem. sens., 46, 234-249. forno m.g., comina c., gattiglio m., gianotti f., lo russo s., sambuelli l., raiteri l., taddia g. (2016) preservation of quaternary sediments in dsgsd environment: the mont fallére case study (aosta valley, nw italy). alp. mediterr. quatern., 29(2), 181-191. goldthwait r.p., matsch c. (1988) genetic classification of glacigenic deposits. balkema, rotterdam, pp. 294. jaboyedoff m., penna i., pedrazzini a., baro� i., crosta g.b. (2013) an introductory review on gravitational-deformation induced structures, fabrics and modelling. tectonophysics, 605, 1-12. doi: 10.1016/j.tecto.2013.06.027 jomelli v., francou b. (2000) comparing the characteristics of rockfall talus and snow avalanche landforms in an alpine environment using a new methodological approach: massif des ecrins, french alps. geomorphology, 35 (3-4), 181-192. doi: 10.1016/s0169-555x(00)00035-0 kojan e., hutchinson j.n. (1978) mayunmarca rock 59 dgpv effects on quaternary sediments slide and debris flow, peru. in: voight b. (ed.) rockslides and avalanches, 1, natural phenomena. elsevier, amsterdam, 316-361. lasagna m., de luca d.a., clemente p., dino g., forno m.g., gattiglio m., gianotti f. (2013) study on the water supply of the montellina spring by the renanchio stream (quincinetto, turin). it. j. groundwat., 131, 75-85. doi: 10.7343/as-020-13-0044 luckman b.h. (1977) the geomorphic activity of snow avalanches. geogr. ann. a, 59 (1-2), 31-48. doi: 10.2307/520580 massironi m., bistacchi a., dal piaz g.v., monopoli b., schiavo a. (2003) structural control on massmovement evolution: a case study from the vizze valley, italian eastern alps. ecl. geol. helv., 96, 85-98. massironi m., genevois r., stefani m., floris m. (2010) how an antiformal structure may influence a large mass movement on foliated metamorphic rocks: the case of passo vallaccia dsgsd (eastern italy alps) investigated through 2d distinct element modelling. bull. eng. geol. envir., 70, 479-501. matthews j.a., shakesby r.a., owen g., vater a.e. (2011) pronival rampart formation in relation to snow-avalanche activity and schmidt-hammer exposure-age dating (shd): three case studies from southern norway. geomorphology, 130 (3-4), 280-288. doi: 10.1016/j.geomorph.2011.04.010 morelli s, pazzi v., frodella w., fanti r. (2018) kinematic reconstruction of a deep-seated gravitational slope deformation by geomorphic analyses. geosciences, 8, 26. doi: 10.3390/geosciences8010026 ostermann m., koltai g., spötl c., cheng h. (2016) deep-seated gravitational slope deformations in the vinschgau (northern italy) and their association with springs and speleothems. geophys. res. abstracts egu general assembly, vienna, 18. ostermann m., sanders d. (2017) the benner pass rock avalanche cluster suggests a close relation between long-term slope deformation (dsgsds and translational rock slides) and catastrophic failure. geomorphology, 289, 44-59. doi: 10.1016/j.geomorph.2016.12.018 piras m., taddia g., forno m.g., gattiglio m., aicardi i., dabove p., lo russo s., lingua a. (2017) detailed geological mapping in mountain areas using an unmanned aerial vehicle: application to the rodoretto valley, nw italian alps. geomat. nat. haz. risk, 8, 137-149. doi: 10.1080/19475705.2016.1225228 polino r., dela pierre f., fioraso g., giardino m., gattiglio m. (2002) foglio 132-152-153, “bardonecchia”. carta geologica d'italia alla scala 1:50.000. serv. geol. it. ispra. polino r., carraro f., martin s., baggio p., baster i., bertolo d., fontan d., gianotti f., malusà m.g., monopoli b., mosca p., perello p., schiavo a., venturini g., vuillermoz r. (2015) foglio 90, “aosta”. carta geologica d'italia alla scala 1:50.000. serv. geol. it. ispra. radbruch-hall d.h. (1978) gravitational creep of rock masses on slopes. develop. geotec. engin., 14, 607-657. doi: 10.1016/b978-0-444-41507-3.50025-8 radbruch-hall d.h., varnes d.j., savage w.z. (1976) gravitational spreading of steep-sided ridges (“sackung”) in western united states. bull. intern. ass. eng. geol., 13(1), 23-35. doi: 10.1007/bf02634754 shea t., van wyk de vries b., pilato m. (2008) emplacement mechanisms of contrasting debris avalanches at volcán mombacho (nicaragua), provided by structural and facies analysis. bull. volcanol., 70, 899. doi: 10.1007/s00445-007-0177-7 terry j.p., goff j. (2014) megaclasts: proposed revised nomenclature at the coarse end of the udden-wentworth grain-size scale for sedimentary particles. j. sediment. res., 84, 192-197. doi: 10.2110/jsr.2014.19 thorne c.r., bathurst j.c., hey r.d. (1987) sediment transport in gravel�bed rivers. wiley, pp. 995. udden j.a. (1914) mechanical composition of clastic sediments. geol. soc. am. bull., 25, 655-744. varnes d.j., radbruch-hall d., varnes k.l., smith w.k., savage w.z. (1990) measurement of ridgespreading movements (sackungen) at bald eagle mountain, lake county, colorado, 1975-1989. u.s. geol. surv. open-file rep., 13, 90-543. doi: 10.3133/ofr90543 wentworth c.k. (1922) a scale of grade and class terms for clastic sediments. j. geol., 30, 377-392. wentworth c.k. (1935) the terminology of coarse sediments. nat. res. counc. bull., 98, 225-246. zorzi l., massironi m., surian n., genevois r., floris m. (2014) how multiple foliations may control large gravitational phenomena: a case study from the cismon valley, eastern alps, italy. geomorphology, 207, 149-160. doi: 10.1016/j. geomorph.2013.11.001 60 forno m.g. et al. ms. received: may 10, 2019 revised: april 1, 2020, accepted: april 3, 2020 available online: april 16, 2020 provenance of the cotignola quarry sands (northern apennines) as a tool for palaeogeographical studies on the action of senio and santerno rivers in the romagna floodplain valentina marconi1, carlotta franceschelli2, stefano marabini2, gianbattista vai1 & gian gaspare zuffa1 1università degli studi di bologna, dipartimento di scienze della terra e geologico-ambientali 2università degli studi di bologna, dipartimento di archeologia e-mail: valentina.marconi@libero.it. abstract: marconi et al.: provenance of the cotignola quarry sands (northern apennines) as a tool for palaeogeographical studies on the action of senio and santerno rivers in the romagna floodplain. (it issn 0394-3356, 2008). palaeogeographic studies on western romagna plain focus on the location of the ancient pattern of santerno river, that nowadays joins reno river before reaching the adriatic sea near ravenna. several authors agree on locating this river in an eastern position during roman age and suggest an overlap of santerno and senio rivers in the cotignola floodplain (fig. 2). outcrops of recent fluvial sediments are exposed at cotignola quarry, near faenza (northern apennines, italy). according to the the present hydrography, the top sediments (age: ca 1.000 yrs) were deposited only by the action senio river. on the contrary, the most ancient alluvial deposits of cotignola quarry display different geological features suggesting a combination of santerno and senio contributions. in the sediment source areas of both rivers there are extensive sandstones and marls outcrops belonging to the “marnoso-arenacea” formation. though, the santerno source area stands out because it also contains basic volcanic and metamorphic rocks, coarse-grained carbonates and cherts (deep oceanic and ophiolithic lithotypes belonging to the “ligurian units”). these rocks can be considered as petrographic tracers of santerno drainage basin provenance. sand samples were collected at cotignola quarry and compared by means of petrographical analysis to the present day fluvial sands of santerno deposits, which are to be considered as compositional standard for sediments resulting from the contribution of this river. at cotignola quarry basic volcanic and metamorphic, coarse-grained carbonate and chert rock fragments occur in the most ancient sediments, whereas they decrease or disappear upward in the more recent sediments. these results prove that the upper sand top of cotignola quarry is due only to sedimentation by senio river, while the lower layers can be considered as the result of contributions from both rivers. furthermore, a sand sample was collected near maiano monti (age: ca 2.200 yrs bp, radiometric dating), which is located in the floodplain included between senio and santerno close to the northern part senio river (fig. 4). the petrographic analyses detect the presence of the ophiolithic tracers in the composition of sands collected at maiano-monti. the sediments provenance implement the hypothesis of an eastern location of roman santerno river in the cotignola floodplain and suggest an overlap of its ancient pattern with that of senio river, according to the archeologic and stratigraphic evidences (fig. 2 and 3). riassunto: marconi et al.: provenienza delle sabbie alluvionali recenti della cava di cotignola e implicazioni sullo studio della paleogeografia dei fiumi senio e santerno nella pianura romagnola (it issn 0394-3356, 2008). gli studi di paleoidrografia storica della porzione occidentale della pianura romagnola sono imperniati, soprattutto, sulla ricerca del tracciato antico del fiume santerno, il quale proviene dall'imolese e attualmente confluisce nel fiume reno poco prima della foce di questo nell'adriatico, a nord di ravenna. la maggioranza degli autori recenti concorda sull'ipotesi che durante l'epoca romana il santerno avesse in pianura un tracciato più orientale di oltre una decina di kilometri rispetto all'attuale, attraversando la zona di cotignola, a nord di faenza, oggi solcata dal solo torrente senio (fig. 2). nella porzione sommitale della cava per laterizi di cotignola affiorano sabbie alluvionali (deposte circa 1.000 anni fa secondo la profondità del piano di calpestio medievale nell'area) geomorfologicamente correlabili con il vicino dosso fluviale del senio. a profondità di oltre 5-6 m affiorano argille e sabbie in facies di piana esondabile sottostanti i piani di calpestio di età romana. allo scopo di verificare la provenienza delle alluvioni di età romana e pre-romana della cava di cotignola, sono stati raccolti dei campioni di sabbie per l'analisi petrografica lungo l'intera sezione stratigrafica e confrontati con un campione di sabbie prelevate nell'alveo attuale del santerno, circa 10 km a valle di imola. infatti, in entrambi i bacini appenninici fonte di sedimento per il senio e il santerno affiorano estesamente le arenarie arcosiche e le marne della formazione “marnoso-arenacea”, ma solamente in quello del santerno affiorano anche rocce basiche vulcaniche e metamorfiche, selci e carbonati a grana grossa, cioè litotipi oceanici profondi e ofiolitici delle “unità liguridi”. questi ultimi (ed in particolare le ofioliti) hanno quindi assunto, ai fini di questo lavoro, il significato di traccianti per discernere la provenienza dei granuli dall'area fonte del santerno. le sabbie basali della cava cotignola risultano ricche in carbonati a grana grossa e selci e contengono frammenti di rocce basiche vulcaniche e metamorfiche, mentre quelle sommitali sono relativamente povere in queste componenti. in sostanza, i risultati dell'analisi modale confermano la deposizione da parte del solo senio per gli strati sommitali della cava, mentre indicano, ragionevolmente, un contributo anche da parte del santerno per la deposizione dei sedimenti profondi e più antichi. un ulteriore confronto è stato eseguito con un campione di sabbie medio-grossolane, per cui la datazione radiometrica (14c) ha indicato un'età compresa tra 2.300-2.110 e 2.200-2.090 anni, prelevato in carotaggio a profondità di circa 11 metri presso maiano monti, località prossima al corso del senio ubicata circa 12 km a nord di cotignola (fig.4). anche la composizione di questo campione di sabbie depostesi in età immediatamente pre-romana mostra un probabile contributo di granuli provenienti dal bacino di drenaggio del santerno, inclusa la presenza dei traccianti ofiolitici, analogamente ai sedimenti basali della cava di cotignola dallo studio sulla provenienza delle sabbie della piana di cotignola si conferma più compiutamente l'ipotesi, in accordo con le ricostruzioni paleoidrografiche su base archeologica descritte in figura 2, della presenza di un tracciato in questa zona del santerno in età romana e pre-romana, al quale, dopo il suo spostamento verso ovest in epoca medievale, si è poi sovrapposto l'attuale dosso fluviale del senio. keywords: geoarcheology, sedimentary petrography, provenance of arenites, western romagna plain, santerno river parole chiave: geoarcheologia, petrografia sedimentaria, provenienza arenarie, pianura romagnola occidentale, fiume santerno il quaternario italian journal of quaternary sciences 21(1b), 2008 139-146 140 marconi et al. 1. introduction palaeogeographic studies on western romagna plain focus on the location of the ancient pattern of santerno river, that nowadays joins reno river before reaching the adriatic sea near ravenna. according to plinio il vecchio, the ancient santerno ended directly in the southern part of the po' delta after crossing spina (fig. 1). several authors discussed on this topic in the last years (gambi, 1949; veggi, 1963; veggi-roncuzzi, 1973; ve g g i a n i, 1968; 1973; 1975; cr e m o n i n i, 1994; 2003; fr a n c e s c h e l l i & ma r a b i n i, 2004; 2007); most of them agree on locating this river in an eastern position during roman age and suggest an overlap of santerno and senio rivers in the cotignola floodplain (fig. 2). in order to investigate on this hypothesis, some outcrops of recent fluvial sediments exposed at cotignola quarry, near faenza were surveyed and sand samples were collected for petrographic analysis (fig. 3). the outcropping sediments show floodplain sedimentary features and their age varies from ca 1.000 yrs at the top to about 3.000-4.000 yrs at the bottom of the quarry section (based on the archeologic source). according to the hypothesis of an eastern location of roman santerno, a change in fluvial contributions could be found between the bottom and the top sediments. the main goal of this study is determining the provenance of the alluvial sediments of the cotignola floodplain: the top layers of cotignola quarry are probably due to the only action of senio river (present days hydrography), whereas the bottom layers can be considered as the result of both rivers contributions. in both senio and santerno sediment source areas arkosic sandstones and marls outcrop extensively, though santerno source area stands out for including oceanic lithotypes (basic volcanic and metamorphic rocks, coarse-grained carbonates and cherts), which characterize sediments due to the action of this river. with this aim, the sand samples collected at cotignola quarry were compared by means of petrographic analysis to the present days fluvial sands of santerno deposits, which are to be considered as compositional standard for sediments resulting from the contribution of this r iver (fig. 4). furthermore, a sand sample was collected near maiano monti (age: 2090-2300 yrs bp, 1 4c), which is located in the floodplain included between present days senio and santerno rivers (fig. 4). fig. 1 geographic location and hydrography of the western romagna plain with the rivers santerno and senio (from franceschelli & marabini, 2004). inquadramento geografico dell'area di studio (da franceschelli e marabini, 2004). fig. 2 hypothetic pattern of roman santerno, location of the main archeologic sites and of paleohydrographic traces, in grey, (from franceschelli & marabini, 2004). ipotetico tracciato del santerno romano e mappa dei principali siti archeologici e delle tracce paleoidrografiche, in grigio,(modificato da franceschelli e marabini, 2004). 141provenance of the cotignola quarry sands... fig. 3 -stratigraphic section of the cotignola floodplain (cq: samples collected at cotignola quarry, faenza). sezione stratigrafica della piana di cot ignola (cq: campioni prelevati presso la cava di cotignola, faenza). fig. 4 the cotignola floodplain: sand samples were collected at the locations idicated by numbers: 1maiano monti (alluvial sands), 2cotignola quarry (alluvial sands), 3santerno river (fluvial sands). ubicazione dei campioni per l'analisi petrografica prelevati nella piana di cotignola: 1maiano monti (sabbie alluvionali), 2cava cotignola (sabbie alluvionali), 3fiume santerno (sabbie fluviali). 2. methods the petrographical analysis is carried out on 350 grains, which are classified between the categories listed in the appendix table. furthermore, about 200 additional rock fragments are investigated for each samples, as those grains are considered especially representative of the sediments source area. in order to keep the compositional data independent from the textural features of the sediments, a point-counting analysis was performed according to the gazzi-dickinson method (zuffa, 1987). as the number of samples collected in some location (e.g. maiano monti) is restricted, standard deviations are not reported in the appendix table. however, the results of petrographic analyses are consistent between samples belonging to homogeneous groups and the conclusions are supported by qualitative differences (presence/absent of discriminative lithotypes). samples col lected at cotignola quarry and maiano monti consist of fine-grained alluvial sands, whereas the present days santerno sediments are fluvial coarse sand. 3. results present days santerno fluvial sands are feldspatic lithoarenites. on the contrary, sands belonging to the top layers of cotignola quarry can be classified as lithic arkose. in the chart cotignola bottom layers and maiano monti samples show an average position between the two compositional standards (fig. 5). the relationship between the provenance index and the percentage of coarse and mixed-grained carbonates for the groups of samples investigated is reported in figure 6. the provenance index (ip= 100*f/f+r) indicates the origin of the source rock. granites and first cycle sandstones produce high ip sediments, whereas sands with low ip derive from volcanic, metamorphic or deep sedimentary oceanic rocks. cotignola top layers are characterized by higher ip (predominance of feldspar grains) and have a low content of coarse and mixed-grained carbonates (scarcity of deep sedimentary oceanic component). on the contrary, santerno fluvial sands show lower ip and a higher 142 fig. 5 main siliciclastic components: quartz, feldspar, finegrained rock fragments. compositional classification from folk et al. (1971). diagramma per la discriminazione dei principali componenti terrigeni: quarzo, feldspati, frammenti di roccia a grana fine. i campi composizionali sono riportati secondo folk et al. (1971). fig. 6 on the x axys percentage of coarse and mixed grained carbonates, on the y axys provenance index ( ip= 100*feldspar/feldspar+rock fragments). indice di provenienza delle sabbie (percentuale del rapporto feldspati/feldspati + frammenti di roccia) in relazione alla percentuale di calcari a grana grossa e mista presente nel sedimento. marconi et al. 143 app. quantitative petrographic analysis, the values are percentages (nce:non carbonate extrabasin, ce: carbonate extrabasin, nci: non carbonate intrabasin, ci: carbonate intrabasin, l: rock fragment, uf: undetermined grain ,x: cement, q:quartz, f:feldspar, p: plagioclase, k: k-feldspar, cq: cotignola quarry). app. analisi modale, i valori sono riportati in percentuale (nce: granuli non carbonatici extrabacinali, ce: carbonati extrabacinali, nci: non carboanti intrabacinali, ci: carbonati intrabacinali, l: litici, uf: granuli indeterminati, x: cementi, q: quarxo, f: feldspati, p: plagioclasio, k: k-feldspato, cq: cava cotignola). provenance of the cotignola quarry sands... percentage of coarse and mixed-grained carbonates. cotignola bottom layers and maiano monti sands have intermediate values of these parameters. the diagram of the fine-grained rock fragments (fig. 7) points out the abundance of sedimentary rock fragments in the cotignola top sands, whereas santerno fluvial sands and maiano monti sample have the highest percentage of volcanic and metamorphic rock fragments. when compared with the others groups of samples, cotignola bottom sands show average content of the three categories of rock fragments. the same trend can be observed in the diagram of figure 8: santerno fluvial sands and maiano monti have the highest percentages of carbonate and siliciclastic fine-grained rock fragments, cotignola top layers has the lowest and cotignola bottom samples still show an intermediate composition. as the average grain size of cotignola sands is much lower then that of santerno fluvial sands, the difference between their contained of coarse-grained rock 144 fig. 7 fine-grained rock fragments ternary diagram. sedimentary, volcanic, metamorphic. diagramma per la discriminazione dei frammenti di roccia a grana fine: sedimentari, vulcanici, metamorfici. fig. 8 rock fragments ternary diagram: carbonate, siliciclastic fine-grained and siliciclastic corse-grained. diagramma per la discriminazione tra frammenti di roccia carbonatici e non carbonatici a grana fine e grossa. fig. 9 rock fragments ternary diagram. siliciclastic sedimentary rock fragments, oceanic lithotypes rock fragments and carbonate rock fragments. confronto tra il contenuto in litotipi dell'unità ligure e quello in frammenti arenitici derivanti dalla marnoso arenacea. fragments is even underevaluated. the diagram of figure 9 considers three groups of rock fragments, selected on the base of the main lithotypes exposed in the source areas of present senio and santerno rivers. as stated before, siliciclastic sedimentary rock fragments outcrop extensively in both drainage basins, whereas oceanic ophiolithic and sedimentary lithotypes (diabase, chert, serpentinite, basic volcanic) characterize santerno source area, where carbonate turbidite deposits are also exposed. it has to be noticed that cotignola bottom layers show average percentages of the rock fragments considered in figure 9, while santerno fluvial sands have the highest content of carbonate and oceanic rock fragments, cotignola top sands result the richest in sandstones, siltstones and argillites. in the diagram of figure 9 maiano monti sands have percentages of the three groups of rock fragments similar to those of santerno sediments. the diagram of figure 10 focus on the relationship between the percentage of sandstones on rock fragments and the percentage of oceanic lithotypes on the sum of all rock fragments. santerno fluvial sands and cotignola samples have the same trend shown in the previous diagram, whereas in this case maianomonti sands have again intermediate values. the volcanic and metamorphic oceanic rock fragments, which are common in santerno source area, can be considered as tracers of this river drainage basin (some chert can be found also in the sandstones outcropping in both river drainage basins). figure 11 clearly shows the absence of the tracers in the samples collected at cotignola top layers, the low percentages in cotignola bottom layers and maiano monti sands, the maximum content in present santerno sediments. all samples groups contain chert, though the percentage of this lithotype gradually increases from the top of cotignola quarry to the santerno fluvial sands. finally, santerno fluvial sands also contain traces of glauconitic sandstone and of cherty limestone. marconi et al. 4. discussion the marnoso-arenacea formation (turbidite deposits of arkosic sandstones) outcrop extensively in both santerno and senio rivers drainage basins. thus, the lithotypes deriving from this formation can be found in the sediments due to the contribution of both rivers. according to cavazza et al. (1993), these lithotypes are: • quartz and feldspar grains • siliciclastic coarse grained sedimentary rock fragments, mainly sandstones • siltstones and argillites deriving from the fine-grained strata of the turbidite deposites • calcite single crystals and fossil single skeleton a deep oceanic sequence, the so-called ligurian units, outcrops only in the inner part of santerno source area. the main lithotypes characterizing this deep oceanic rocks are listed below: • fine-grained volcanic and metamorphic rock fragments, which derive from sill and dykes of the oceanic ridge. • coarse and mixed-grained carbonates, and cherts from the deep oceanic sedimentary sequence • diabase, serpentinite and basic volcanics, which derive from the ophiolitic deposits of oceanic vulcanism and metamorphism • glauconite in sandstone rock fragments and cherty limestone are common in some formation belonging to the ligurian units, such as arenarie di bismantova. present days santerno fluvial sands are to be considered as compositional standard for sediments resulting from the contribution of this river, which drains both the marnoso-arenacea formation and the ligurian units. according to the present hydrography, the sands collected at the top of cotignola quarry were deposited only by the action of senio river, which drains mainly the marnoso-arenacea formation. quantitative analysis show that these sands contain the highest percentage of feldspar, coarse-grained siliciclastic rock fragments and sandstone (fig. 5, 8 and 10 respectively), while the percentage of coarse-grained carbonates and chert are the lowest (fig. 11). qualitative analysis point out the absence of the ophiolithic tracers: serpentinite, diabase and basic volcanics. the results indicate that cotignola quarry top sands derive mainly from marnoso-arenacea formation. thus it is possible to prove that they were deposited only by the action of senio river. cotignola bottom layers are characterized by intermediate composition between the two standards (present days santerno fluvial sands and cotignola top layers), which can be observed in every diagram. the ophiolithic tracers of santerno drainage basin are present in these sands, but the percentages of serpentinite, diabase and basic volcanics are lower then in santerno fluvial sands (fig. 11). the results suggest that the cotignola bottom sands are due to both rivers contribution, which implies some remarkable changes in the hydrographic pattern of cotignola floodplain in the last thousand years. the composition of sands collected at maianomonti (located near senio river, in the northern part of this river fluvial plain) is close to that of santerno fluvial samples: they have similar percentages of both siliciclastic and carbonate rock fragments (fig. 7, 8 and 9 respectively). the relationship between the main siliciclastic components (fig. 5), the provenance index and the contained of coarse and mixed-grained carbonate rock fragments (fig. 6), the percentage of sandstone (fig. 10) and the presence of the ophiolithic tracers (fig. 11) suggest also for these sediments a provenance from both rivers source area. 145 fig. 10 on the x axys: percentage of sandstone rock fragments on the sum of all sedimentary rock fragments; on the y axys: percentage of ophiolithic rock fragments on the sum of all rock fragments. percentuale dei frammenti di arenaria sul totale dei litici sedimentari in rapporto alla percentuale di granuli ofiolitici sul totale dei frammenti di roccia. provenance of the cotignola quarry sands... 5. conclusions at cotignola quarry sands composition changes from bottom to top layers, showing first the presence of basic volcanics, diabase, serpentinite, coarse-grained carbonate and chert rock fragments, and then the decrease or disappearance of those elements. diabase, serpentinite and basic volcanics rock fragments (ophiolitic tracers) characterize present days santerno river sands and can be found also in samples collected at maiano-monti. the results of petrographical analysis pont out that the sand top layers of cotignola quarry are probably due to the only action of senio river, whereas the bottom layers and maiano-monti sands can be considered as the result of both rivers contributions. the sediments provenance implement the hypothesis of an eastern location of roman santerno river in the cotignola floodplain and suggest an overlap of its ancient pattern with that of senio river, according to the archeologic and stratigraphic evidences (fig. 2 and 3). 6. references ca v a z z a w., zu f f a , g. g., ca m p o r e s i, c., fe r r e t t i, c. (1993) sedimentary recycling in a temperate climate drainage basin (senio river, north-central italy): composition of source rock, soil profiles, and fluvial deposits: in johnsson, m. j., basu, a., eds., processes controlling the composition of clastic sediments, boulder, colorado, geological society of america special paper, n. 2 8 4, pp. 247-260. cremonini s. (1994) lineamenti evolutivi del paesaggio fisico del territorio di bagnacavallo nel contesto paleoidrografico romagnolo : in storia di bagnacavallo, i, bologna 1994, pp. 1-140 cr e m o n i n i s. (2003) tra idice e santerno: problemi paleoidrografici in castel guelfo di bologna: un caso di studio. geologia, archeologia e storia dell'insediamento tra idice e sillaro, bologna 2003, pp. 18-55 fo l k r.l., an d r e w s p.b., le w i s d. w. (1971) d e t r i t a l sedimentary rock classification and nomenclature for use in new zealand new zealand journal of geology geophysics, v. 13, pp.937-968. fr a n c e s c h e l l i c., ma r a b i n i s. (2004) assetto paleoidrografico e centuriazione romana nella pianura f a e n t i n a “agri centuriati. journal of landscape archaelogy”, 1, 2004, pp. 87-107 franceschelli c., marabini s. (2007) lettura di un territorio sepolto-la pianura lughese in età romana bologna, 2007, 222 p. ga m b i l. (1949) l'insediamento umano nella regione della bonifica romagnola roma, 1949 veggi l. (1963) gli antichi porti e le trasformazioni idrografiche nel territorio di bagnacavallo bollettino economico camera di commercio di ravenna, 3, 1963, pp. 195-200 veggi l., roncuzzi a. (1973) appunti per la storia antica del fiume santerno nel territorio della bassa pianura ravennate bollettino economico camera di commercio ravenna, 6, 1973, pp. 541-550 veggiani a. (1968) l'influenza delle condizioni geologiche del sottosuolo sull'evoluzione della rete idrografica nell'area di alfonsine (pianura ravennate) studi romagnoli, xix, 1968, pp. 201-208 ve g g i a n i a. (1973) il corso del fiume santerno nel delta padano in epoca roman abollettino economico camera di commercio ravenna, 2 8, 1973, pp. 139-147 ve g g i a n i a., (1975) le vicende idrografiche del santerno da imola al mare nell'antichità studi romagnoli, xxvi, 1975, pp. 3-21 zuffa g.g. (1987), unravelling hinterland and offshore palaeo-geography from deep-water arenites in leggett j.k. and zuffa g.g., eds., marine clastic sedimentology concepts and case studies, graham and trotman, pu., london, p. 39-61. 146 fig. 11 percentage of diabase, basic volcanics, serpentinite and chert in the four samples groups. variazione del contenuto di diabasi , selci, serpentiniti massive e vulcaniti basiche. ms. ricevuto il 1° marzo 2008 testo definitivo ricevuto il 23 maggio 2008 ms. received: march 1, 2008 final text received: may 23, 2008 marconi et al. imp.codici codici di nomenclatura stratigrafica i codici di nomenclatura stratigrafica negli ultimi cinquant'anni maria bianca cita abstract: m. b. cita, the codes or guides of stratigraphic nomenclature in the last fifty years. the first italian code of stratigraphic nomenclature was published in 1968 by the geological survey of italy. co-authored by a. azzaroli and m.b. cita with the collaboration of r. selli, it was realized under the auspices of the “comitato geologico” chaired by a.desio. simple, pragmatic, concise, it was inspired by the international guide authored by the chair of the international subcommission on stratigraphic classification (issc) h.d. hedberg, to be published in 1976. the very rapid development of stratigraphy in the last thirty years with the introduction of new methodologies, an integrated approach to chronocorrelation and the availability of an immense data set deriving from the scientific exploration of the oceans and of remote areas of our planet requires updates and implementations of the guides. the italian commission on stratigraphy, in collaboration with the geological survey, prepared a new version, published in 2003. a new version of the international guide is also under preparation, with a bottom up approach involving specialists of the various subdisciplines currently used in stratigraphy. parole chiave: nomenclatura stratigrafica, guide, codici. keyword : stratigraphic nomenclature, guides, codes. il quaternario italian journal of quaternary sciences 21(1a), 2008 7-8 l'idea di codificare la nomenclatura stratigrafica in modo chiaro, pragmatico e universale si è sviluppata verso la metà del millenovecento negli stati uniti d'america ad opera di hollis d.hedberg, che veniva dall'esplorazione petrolifera e fu per decenni professore di stratigrafia all'università di princeton. a lui si deve la creazione prima del nacsn (north american commission on stratigraphic nomenclature) nel 1950 e dell' international committee on stratigraphic classification (nel 1952) prima ancora che fosse costituita l'unione internazionale delle scienze geologiche (iugs). prima di allora la stratigrafia, sviluppatasi essenzialmente in europa con le forti scuole inglese (vedi schema di lyell 1875 nel logo di questo workshop), francese e tedesca, procedeva per trattati e autori, con qualche influenza esercitata dai congressi geologici internazionali, da quando essi iniziarono ad essere indetti. l'italia non aveva scuole sue proprie a causa della parcellizzazione politica. nell'italia settentrionale si sente l'influenza delle scuole francese e austriaca. in questa situazione mancava un “controllo di qualità” sui prodotti e si faceva a gara nell'istituire nuovi piani geologici mescolando spesso anche inavvertitamente caratteri litologici e cronologici e con scarsa conoscenza del potenziale di correlazione delle faune fossili. hedberg impiegò più di vent'anni e molte decine di circolari distribuite ai numerosi membri della issc (a quei tempi le comunicazioni erano molto più lente, difficili e costose di quanto lo siano oggi) per pubblicare la prima guida internazionale alla classif icazione stratigrafica (hedberg, 1976). in essa viene chiaramente proposta la identificazione di diversi tipi di unità stratigrafiche: litostratigrafiche, biostratigrafiche e cronostratigrafiche e vengono definite le procedure per la loro validazione. si tratta di un approccio semplice e pragmatico, che ha dovuto superare molte difficoltà per essere accettato in diversi paesi, ma che alla fine è stato largamente adottato. prima della pubblicazione del volume da parte di una compagnia privata (hedberg, 1976, john wiley & sons, new york) diverse parti e/o capitoli erano stati stampati su riviste internazionali. la stessa rivista italiana di paleontologia e stratigrafia aveva tradotto le parti essenziali dell'opera nel 1962. quando negli anni sessanta del secolo scorso venne approvata la legge sullo per il completamento della carta geologica d'italia da parte del servizio geologico, con la partecipazione di molte sedi universitarie, il comitato geologico, presieduto da ardito desio, nominò un a commissione italiana di stratigrafia e affidò ad augusto azzaroli e maria bianca cita l'incarico di redigere un codice italiano di nomenclatura stratigrafica nel quale fossero indicate le procedure per la distinzione delle diverse unità stratigrafiche da utilizzare nelle nuove carte (azzaroli & cita, 1968). questo codice italiano uscì dunque diversi anni prima di quello di hedberg, al quale era ispirato. accanto a questa iniziativa, si procedette alla pubblicazione di una serie di fascicoli illustrativi delle diverse formazioni (unità litostratigrafiche) riconosciute in italia. edizioni successive della guida internazionale furono pubblicate da salvador (1994) e da murphy e 8 maria bianca cita salvador (1999). la prima, pubblicata dalla società geologica americana e dall'agi, è sostanzialmente una riproduzione di quella di hedberg con l'aggiunta di due capitoli: uno sulla stratigrafia paleomagnetica, molto primitivo, e uno sulle unità a limiti inconformi, assai discutibile e di difficile applicazione. la seconda è una versione abbreviata, pubblicata sull'organo ufficiale dell'iugs episodes. non è il caso di parlare qui adesso delle numerose guide nazionali, pubblicate in diversi paesi e in diverse lingue. ma ritornando all'italia e ai nostri problemi di classificazione stratigrafica, una nuova edizione aggiornata della guida è stata redatta da daniela germani e lucia angiolini, a cura della rinnovata commissione italiana di stratigrafia e con la supervisione della sottoscritta. il progetto è stato completato nell'ambito di una serie di accordi di programma e di contratti della durata complessiva di sette anni stipulati fra il servizio geologico e il cnr, o l'università di firenze, o l'istituto cnr di pisa. l'iniziativa era partita dall'ultimo comitato 05 del cnr presieduto da piero manetti, che era il contraente. fra i prodotti di questa iniziativa, oltre alla guida (germani & angiolini, 2003) pubblicata sul quaderno serie iii, n. 9, vi sono anche sette fascicoli del quaderno n. 7 della stessa serie, dedicati all'illustrazione delle formazioni validate e di quelle non validate dalla commissione italiana di stratigrafia, nonché dei nomi tradizionali. in campo internazionale infine è iniziato un nuovo progetto nell'ambito della issc (international subcommission on stratigraphic classification), che a partire dal 2003 è presieduta dalla sottoscritta. il primo workshop della issc si è tenuto a firenze nal 2004, nell'ult ima giornata del congresso geologico internazionale. in quella sede si è deciso di seguire un nuovo approccio bottom up invece di top down. infatti la stratigrafia ha avuto tali e tanti sviluppi negli ultimi trent'anni, sviluppando nuove metodiche di ricerca e accumulando una mole incredibile di dati provenienti dalle perforazioni oceaniche e da altri importanti progetti di ricerca da rendere indispensabile un aggiornamento della guida e da consigliare di suddividere la responsabilità fra i migliori specialisti del momento, siano o non siano essi membri della sottocommissione. si tratta di un progetto molto ambizioso e difficile, che darà luogo a un workshop intitolato new developments in stratigraphic classification al congresso geologico internazionale di oslo 2008. tutti gli stratigrafi italiani interessati all'argomento sono invitati a prendervi parte (hps-12 e wss-11). i primi prodotti dell'iniziativa sono appena usciti sulla rivista internazionale newsletters on stratigraphy: si tratta di un articolo introduttivo (cita, 2006) e di un saggio sulla ciclostratigrafia (strasser et al, 2006). bibliografia anonimo (1962) codice di nomenclatura stratigrafica secondo i nord-americani. rivista italiana di paleontologia e stratigrafia, 68(1), pp. 115-148. azzaroli a. & cita m.b. (1968) codice italiano di nomenclatura stratigrafica. boll. serv. geol. it., v. 89, pp. 1-22. cita m.b. (2006) new developments in stratigraphic classification. a project of the international subcommission on stratigraphic classification issc. newsletter on stratigraphy, v. 42(2), pp. 69-74. germani d. & angiolini l (2003) guida italiana alla classificazione e terminologia stratigrafica. apat, dipartimento per la difesa del suolo, quaderni serie iii, n. 9, pp. 1-155. hedberg h. (ed.)(1976) international stratigraphic guide. a guide to stratigraphic classification, terminology and procedure. pp. 1-200. john wiley & sons. new york. lyell c. (1875) principles of geology. xii edition murphy m.a. & salvador a. (1999) international stratigraphic guide an abridged version. episodes, v. 22, pp. 255-271. salvador a. (ed.)(1994) international stratigraphic guide. second edition. pp. 1-214. geol. soc. of america. strasser a., hilgen f.j. & heckel p.h. (2006) cyclostratigraphy concepts, definitions, and applications. newsletter on stratigraphy, v. 42(2), pp. 75-114. ms. ricevuto il 2 aprile 2008 testo definitivo ricevuto il 17 aprile 2008 ms. received: april 2, 2008 final text received: april 17, 2008 amq82 mancini et al proofcopy f available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 31 (2), 2018, 171 194 stratigraphy of the palatine hill (rome, italy): a record of repeated middle pleistocene-holocene paleovalley incision and infill marco mancini1, mattia marini2, massimiliano moscatelli1, francesco stigliano1, gian paolo cavinato1, cristina di salvo1, maurizio simionato1 1 consiglio nazionale delle ricerche, istituto di geologia ambientale e geoingegneria, rome, italy 2 università degli studi di milano, dipartimento di scienze della terra “a. desio”, milan, italy corresponding author: m. mancini <marco.mancini@igag.cnr.it> abstract: the palatine hill in rome (italy) represents a key site for better understanding the middle pleistocene-holocene continental deposits of the rome basin that could be investigated by the numerous boreholes drilled during the last few decades for archeological and cultural heritage conservation. in this study, 12 cores selected for their excellent recovery rate and stratigraphic coverage are described in detail discriminating 23 lithofacies. the stratigraphic data, used in combination with the information from nearby outcrops and additional boreholes provide insights into the depositional architecture of multiple incised fluvial valley infills developed in response to sea-level fluctuations occurred between marine isotope stages (mis) 16 and 1. these infills comprise a range of fluvial deposits of the tiber river system which interfinger with accurately dated pyroclastites from the alban hills and sabatini mts., thus providing important time constraints on the formation of paleovalleys. the paleovalleys correlated to mis 14-13, 12-11 and 5d-1 have particularly well-preserved infills constituting useful analogues of trunk and tributary paleovalleys. because the recognized lithofacies represents the building blocks of the lithostratigraphic, synthemic and sequence stratigraphic units currently in use at basin-scale, we believe their accurate field and core description complemented by graphical logs and photographic plates is important for identifying similar facies in future investigations on nearby paleovalley infills. keywords: fluvial paleovalleys, middle pleistocene, holocene, rome, facies analysis 1. introduction urban geology requires thoughtful integration of geognostic data (borehole lithology, geotechnical tests, geophysics) and information from nearby outcrops, which are often sparse due to cover by man-made deposits and structures. in sedimentary successions, this requires a hierarchical approach entailing prior recognition of key stratigraphic surfaces bounding geneticallylinked deposits, followed by detailed borehole lithology correlation. implementing such an approach is particularly challenging in superimposed unconformity bounded stratigraphic units (usbu), such as multiple fluvial incised valleys lacking a robust stratigraphic reference model. fluvial incised valleys, or paleovalleys (sensu blum et al., 2013) develop in the lower reach of fluvial systems as a result of readjustment of the equilibrium profile following base level changes driven by eustasy, tectonics or a combination of the two. during quaternary, the dynamics governing paleovalley incision and sedimentary infill is primarily modulated by glacioeustatic sea-level fluctuations (wright & marriott, 1993; shanley & mc cabe, 1994; blum et al., 2013), with formation of a basal high-relief unconformity deeply eroded into older deposits (or the bedrock) during base level falls and low-stands, and subsequent backfilling during base level rises and high-stands. understanding the subsurface stratigraphy of urban areas characterized by the presence of paleovalleys is made even more challenging by the poor quality and/ or detail consistency of the typically available subsurface data, which are in general compiled from different sources (technical reports, geological maps, research papers) over time spans of a few to several tens of years. however, several study cases exist where physical-stratigraphy, facies analysis and sequence stratigraphy concepts are used to guide interpretation and modelling of subsurface datasets from urban areas (ellison et al., 2004; sarti et al., 2012; amorosi et al., 2013; bridgland et al., 2013; tanabe et al., 2015; milli et al, 2016; van dinter et al., 2017; marini et al., 2018, among the others). the present contribution reports on the sedimentary facies from middle pleistocene to holocene fluvial paleovalley infills from the palatine hill of rome (italy), a world-class archeological site whose subsurface was deeply investigated over the last decades for cultural heritage preservation purposes (cecchi, 2011). based on detailed logging of cores from 12 boreholes with excellent recovery and stratigraphic record and ancillary observations from nearby outcrops (some of which temporary), this work intends to: i) give insights into the facies architecture of excellent examples of paleovalley infills with a well-established stratigraphic framework owing to intercalation of dated volcanics; ii) refine the existing models of subsurface geology (moscatelli et al., 2012, 2014a, 2015; mancini et al., 2013, 2014), and iii) https://doi.org/10.26382/amq.2018.11 172 fig. 1 a) location of the palatine hill within the historical center of rome; the inset is referred to fig. 1b. b) topographic map of the palatine and surrounding areas. mancini m. et al. 173 a key element of the volcano-sedimentary complex is the stack of paleovalley infills (blum et al., 2013), or fluvial incised valleys, and related interfluves resulting from cyclic, syn-uplift phases of fluvial sedimentation and erosion by the tiber river and tributaries (conato et al., 1980; alvarez et al., 1996; milli 1997; karner & marra, 1998; marra et al., 1998, 2008, 2016; milli et al., 2008, 2016; mancini et al., 2013). at present, the upper pleistocene-holocene drainage network of the tiber river is deeply incised into older deposits as a result of the sea-level fall of marine isotope stages (mis) 5d-2 and hosts up to 65 m of upper pleistocene-holocene (mis 2-1) fluvial sediments forming the present-day fluvial plain (bozzano et al., 2000; milli et al., 2016). finally, an almost continuous cover of anthropogenic deposits is present in the whole urban area, with thicknesses up to 20 m (ciotoli et al., 2015, with references). 3. material and methods in this work we adopt the high-rank unconformity bounded stratigraphic units (ubsu), or synthems, and the lithostratigraphic units that compose them (i.e. formations) of the geological map of italy (map sheet 374 ‘rome’; funiciello & giordano, 2008). bounded by 5 major basal unconformities (unconformities i to v in fig. 3) corresponding to as many phases of fluvial erosion forced by sea level fall and low-stand (even-numbered marine isotopic stages, mis), the above mentioned synthems partly correspond to paleovalleys infills developed during phases of sea level rise and high-stand, which could be correlated with some of the highfrequency low-rank depositional sequences of the composite ponte galeria sequence (fig. 3a; milli, 1997; milli et al., 2008, 2016) well defined w of rome. an additional composite surface (surface vi in fig. 3), locally erosive or depositional, is at the base of the anthropogenic deposits. a sub-set of 12 (most of which double-tube cored) out of 25 continuous-core boreholes (fig. 1) drilled in the 2010 (cecchi, 2011) was selected for their excellent core recovery, stratigraphic record and proximity to key outcrops, and logged in detail recording all relevant sedimentologic, petrographic and pedogenetic information across most of the middle pleistocene-holocene succession. this allowed the distinction of a total of 23 lithofacies (table 1) described in detail in paragraph 4 and illustrated in figs. 4-9 and plate i-iii. after integration with lithostratigraphy from other boreholes and ancillary observations made on nearby key outcrops, including temporary outcrops from archeological excavations and construction sites, the selected core logs were correlated across adjacent sites based on stratigraphic markers (e.g. ignimbrites, fluvial lag deposits, lignite seams, tephras) and used for facies analysis (miall, 1996; orton, 1996; retallack, 2001; amorosi, 2006). 4. results: stratigraphy and sedimentary facies the stratigraphy of the palatine (figs. 3b, 4) includes five of the usbu introduced by funiciello & giordano (2008), namely the flaminia (lmn), villa glori provide detailed descriptions and iconographic material useful for identifying similar facies in future investigations in nearby areas and similar deposits. 2. geological and stratigraphic setting the palatine (fig. 1a) is one of the world-renown “seven hills” of rome, onto which the city was founded (de angelis d’ossat, 1956; heiken et al., 2005; funiciello et al., 2006). it is a 25-ha wide flat-topped hill with an elevation of ca. 50 m a.s.l. composed by a complex stack of sedimentary and pyroclastic rocks. to nw, sw and se the palatine is bounded by the relatively narrow velabro, murcia and labicano alluvial valleys, which separate it from the capitoline, aventine and caelius hills, respectively (fig. 1b). because the palatine hosted the first settlement of ancient rome (brocato & terrenato, 2016), the presentday landscape records a long-lasting history of anthropogenic modifications, witnessed by several superimposed archaeological ruins of different ages. the palatine is bounded to ne by the fori imperiali-roman forum, a mixed natural and anthropogenically-modified depression separating the palatine from the nearby oppius hill. in this specific place, the small former velia hill was present until the 30s of the 20th century (fig. 1b), when it was cut away for the construction of via dei fori imperiali (de angelis d’ossat, 1956; palombi, 1997, 2016; lanzini, 2008; leone et al., 2009). the morphology of the palatine itself was modified. originally, it, featured two culminations to the se and the w of the present-day hilltop referred to by historians as palatium and germalus, respectively (castagnoli, 1980). the seven hills are located at the periphery of the volcano-sedimentary plateau of the alban hills and sabatini mts volcanic districts, whose deposits were incised by the tiber river and its tributaries (fig. 2) (del monte et al., 2016). the pliocene-quaternary succession of the area represents part of the infill of the rome basin, an extensional basin developed since the earliest pliocene as a result of back arc extension in the tyrrhenian sea (patacca et al., 1990; cavinato & de celles, 1999; mattei et al., 2010). the geological bedrock of this succession consists of up to 900 m-thick pliocene marine sediments (comprising the clayey monte vaticano formation), which overlay with angular unconformity the mesozoiccenozoic carbonate and siliciclastic successions of the central apennines (funiciello & parotto, 1978; funiciello & giordano, 2008; giordano & mazza, 2010). the pliocene sediments are in turn overlain by calabrian shallow marine sediments and by a 30-150 m -thick suite of latest early pleistocene-holocene volcanic and sedimentary deposits (conato et al., 1980; milli, 1997; marra et al., 1998, 2008, 2009; giordano et al., 2003, 2006; funiciello & giordano, 2008, 2010; cosentino et al., 2009; luberti et al, 2017). this volcano -sedimentary succession recorded complex phases of syn-uplift, climate-eustatically forced and volcanocontrolled basin infill, with pyroclastites and lavas sourced from the sabatini mts and alban hills districts (fig. 2). stratigraphy of the palatine hill 174 fig. 2 a) simplified geological map of the rome basin. legend: 1) continental and coastal deposits (late early pleistocene-holocene); 2) pyroclastic deposits and lavas of the sabatini mts and alban hills volcanic districts (middle-late pleistocene); 3) marine terrigenous clay and sands (pliocene-early pleistocene); 4) lavas and lava domes of the ceriti mts-tolfa volcanic district (pliocene); 5) marine terrigenous successions of the liguride units, sandstones and marlstones (cretaceous-paleogene); 6) limestone, marls and cherts of the pelagic umbro-sabina succession (trias-miocene); 7) normal fault; 8) buried normal fault. caa is the central archeological area of rome. b) geological map (modified, after mancini et al., 2014) showing the distribution of lithostratigraphic units below the anthropogenic deposits with location of cross-sections of fig. 4, outcrops pictured in figs. 5 and 6, and borehole stratigraphies detailed in figs. 7-9. mancini m. et al. (florindo & marra, 1995) (vgl), torrino (tno), quartaccio (qta) and fiume tevere (sft) synthems, which correspond to as many incised paleovalleys infills and stack spatially to form the volcano-sedimentary multilayer superimposed onto the pliocene marine bedrock. this stack is covered by a thick layer of man-made deposits. in the following paragraphs, the component lithofacies (table 1) and geometrical characters of these units, including the bedrock and the man-made cover, will be described in detail and illustrated with a rich iconographic documentation from 175 fig. 3 a) chronostratigraphic reference scheme for the palatine hill and surrounding areas reporting correlation between (1) sequence stratigraphic units (milli, 1997), (2) lithostratigraphic and unconformity bounded stratigraphic units (funiciello & giordano, 2008) and (3) marine isotope stages (mis; after shackleton et al., 1990). b) simplified sketch of the stratigraphic and facies architecture of the palatine hill and the surrounding labicano and velabro valleys (see a in this figure and text for lithostratigraphic and facies codes). in both figures, stratigraphic surfaces i to v are the unconformities bounding the synthems of funiciello & giordano (2008), and surface vi is at the base of the man-made deposits. stratigraphy of the palatine hill selected core intervals (plates i-iii) and key outcrops (figs. 5, 6). 4.1 pliocene marine bedrock: the monte vaticano formation (mva) in the study area this formation does not crop out but was encountered in numerous boreholes and drilled throughout a total thickness of 500 m by the circo massimo well (cfr with lpa unit in funiciello & giordano, 2008). the formation is represented by a single lithofacies (mva) composed of structureless blue-grey silty clay (plate i a), with rare burrows and marine shells (corbula gibba, venus sp.) and with interbedded dmthick sets of organic-rich cross laminated sands (plate i b). interpretation. the clays of mva are interpreted as the product of fall-out and, subordinately, traction plus fallout deposition by gravity flows in outer shelf to slope offshore marine settings. 4.2 flaminia synthem (lmn) bounded below and above by unconformities i and ii (fig. 3b), respectively, the middle pleistocene synvolcanic flaminia synthem (funiciello & giordano, 2008) can be correlated with mis 16-15 and with the pg3 depositional sequence (milli, 1997). in the study area lmn only comprises the fluvial santa cecilia formation (cil) introduced by marra et al. (1998) and geochronologically constrained by karner & marra (1998). 4.2.1 santa cecilia formation (cil) the santa cecilia formation (cfr. with ‘maremmano’ in de angelis d’ossat, 1956) is up to 20 m thick in the study area and includes two lithofacies, namely channel gravel (cil a) and sand (cil b), occurring respectively below and above a sharp and rather 176 tab. 1 correlation scheme among depositional sequences, synthems, formations and lithofacies. mancini m. et al. >>>>> fig. 4 geological cross-sections (see fig. 2b for location) with distribution of clustered lithofacies described in the text (modified after mancini et al., 2014). the buried normal fault on cross sections 2 and 3 is inferred from the displacement of stratigraphic horizons at the base of and within the fosso del torrino fm; its activity ended before the deposition of the villa senni formation (see mancini et al., 2014, for further details). 177 stratigraphy of the palatine hill capitoline hill capitoline hill palatine hill palatine hill velabro valley labicano valley labicano valley velabro valley aventine hill circo massimo (murcia valley) domus tiberiana roman forum flat intra-formational surface (figs. 8, 9). channel gravel (cil a) this lithofacies is represented by well-sorted, coarse to medium-grained pebbles in a sandy matrix (plate i c) and, subordinately, by sands forming dm-thick lenses with low (m-scale) lateral continuity. clasts are calcareous and subordinately siliceous (up to 10-15%) and typically well-rounded with mainly blade and disc shape. the sandy matrix is fine grained and mainly composed of quartz, feldspar, calcite and, subordinately, volcanic ferro-magnesian minerals. in the study area, cil a forms an 8-20 m-thick wedge-shaped depositional body thickening toward the nw (fig. 4). interpretation. cil a can be interpreted as a stack of longitudinal and transversal bars and bedload sheets infilling the channels of a gravelly braided-type river. major grain-size breaks between pebbles and sands can be interpreted as either bedset boundaries within individual bars and gravel-sand sheets or reflect auto-cyclical reorganization of the channel-network. channel sand (cil b) this facies is composed of silty fine-medium sands (plate i d), typically of a yellow-orange hue, showing either faintly planar-parallel or ripple-drift cross lamination. the mineralogical composition of cil b is the same as the matrix of cil a including relatively abundant chert fragments. locally, dm-thick, normally and inversely graded lamina-sets are observed, which suggests flow velocity fluctuations. in most localities, these sands 178 fig. 5 pictures of key outcrops discussed in the text (see fig. 2b for reference and location). a) roman walls and foundation structures along the north-western side of the palatine. note how these ruins sit directly on top of outcrop 1 (see details in this figure). b) detail of the lowermost part of outcrop 1 showing pedogenized floodplain mud (vgu c) capped by cross-laminated levee sand (vgu b) from the fluvial valle giulia formation. c) detail of outcrop 1 showing cross-laminated levee deposits with a well-developed paleosol on top (vgu b lithofacies) overlain with a sharp but non-erosive contact by the massive ignimbritic palatino unit (pti). note the presence of tree moluds in pti, previously described by de rita et al. (2002). d) from base to top, carbonate-rich silts and concretions (vgu c lithofacies) and the pti and the villa senni formation (vsn) ignimbrites exposed in outcrop a (via della consolazione, southern hillslope of the capitoline hill). e) detail of the pti ignimbrite in outcrop a showing a sub-angular, carbonate lithic fragment, most likely a xenolith (see e.g. funiciello & parotto, 1978). mancini m. et al. 179 fig. 6 a) the superimposed palatino unit (pti), prima porta unit (ppt) and villa senni formation tufo lionato (vsn1a) pyroclastic deposits in outcrop b (via della consolazione). b) detail of outcrop b showing the paleosol separating the palatino unit (pti) from the prima porta unit (ppt). c) epiclastite of the fosso del torrino formation (ftr g) located between the pyroclastites of the prima porta unit (ppt) below and the villa senni formation tufo lionato (vsn1a) above in outcrop 2 (san teodoro church). note the faintly laminated ashy character as well as the pedogenized top of ppt. d) detail of outcrop 3, temporary exposed in april 2015 during the underground line c excavations, showing the fluvial channel sand (ftr b) of the fosso del torrino formation, topped by the villa senni formation tufo lionato (vsn1a) ignimbrites. e) detail of outcrop 4, temporary exposed in may 2018 during the underground line c excavations, showing trough-cross bedded and cross laminated sands (ftr b) of the fluvial fosso del torrino formation. outcrops 3 and 4 are remnants of the former velia hill, cut away in the 30s of the xx century for the construction of via dei fori imperiali (de angelis d’ossat, 1956; lanzini, 2008; leone et al., 2009). f) detail of outcrop 2 showing a columnar gas pipe from the tufo lionato ignimbrite (vsn1a). stratigraphy of the palatine hill 180 grade upward into massive sandy silt (figs. 7-9) bearing rare root traces and mm-to-cm-scale nodules of mn/fe oxides. similar fine-grained facies were reported by florindo & marra (1995) and florindo et al. (2007) from the colosseum core a (fig. 9), which were attributed to the brunhes magnetic chronozone. cil b forms an up to 8 m thick tabular body with an observed minimum lateral continuity of 250 m. interpretation. cil b can be interpreted as a channelfill deposit resulting from amalgamation of subsequent bars and bedload sheets in a sand-dominated river. root traces and nodules can be interpreted to reflect prolonged subaerial exposure and pedogenisation of bar tops. the silty deposits may be related to upper bars and/or abandoned channels. 4.3 villa glori synthem (vgl) the syn-volcanic villa glori synthem (vgl; funiciello & giordano, 2008) is bounded below and above by unconformities ii and iii (fig. 3b) which record the sea level falls occurred between mis 15 and mis 14 and mis 13 and mis 12, respectively. as a result, there is general agreement in correlating vgl with mis 14-13 and the pg4 depositional sequence (milli, 1997; funiciello & giordano, 2008). in the study area, vgl comprises the valle giulia formation (vgu), composing the most of the synthem (figs. 3b, 7), and the palatino (pti) and the prima porta (ppt) pyroclastic units. these units collectively represent of the infill of a nw-se trending paleovalley (mancini et al., 2014). 4.3.1 valle giulia formation, vgu the fluvial valle giulia formation is up to 15 m thick and includes three lithofacies, namely channel gravel (vgu a), channel margin-levee sand (vgu b) and pedogenized floodplain and channel-abandonment silt (vgu c). channel gravel (vgu a) this facies consists of medium to coarse wellrounded blade-shaped pebbles (plates i e, ii a) with an abundant sandy matrix. clast lithology includes limestone, chert and volcanic scoria, whereas the matrix is very rich in calcite, quartz, charcoal debris and volcanic ferro-magnesian minerals (clinopyroxene, biotite and magnetite), which imparts vgu a a dark hue and makes it easily distinguishable from similar lithofacies (e.g. cil a and ftr a). importantly, in the subsurface of the north-eastern hill slope of the palatine, vgu a is intercalated by the pyroclastic palatino unit (pti) (log 11 ms in fig. 7). vgu a exclusively occurs at heights below 15 m a.s.l., infilling the deeper part of unconformity ii (figs. 3 and 4). because of later erosion of unconformity iii, it forms depositional bodies with presumably small lateral continuity and slightly convex erosive base. interpretation. channel-fill fluvial deposits, formed by amalgamation of bars and bedload sheets in a braidedtype river (fig. 7). the abundance of volcanic clasts as well as intercalation of pti testifies syn-volcanic deposition. channel margin-levee sand (vgu b) this facies is represented by light brown to pale fig. 7 correlated sedimentary logs from selected boreholes and key outcrops along the velabro valley and in the north-western palatine (see fig. 2b for location). mancini m. et al. grey, cross-laminated silty fine sand (plates i f, ii b), dominantly composed of quartz, feldspar, muscovite and volcanic ferro-magnesian minerals. vgu b form mthick beds sets (figs. 5 b, c), whose base is locally marked by lags of very fine to fine pebbles. on outcrop, cross bedding and ripple-drift laminations indicate paleoflow direction toward the w (fig. 5 b, c; log 13 ms in fig. 7). locally, root traces and peds are present atop vgu b beds (fig. 5 c). vgu b was encountered at a few sites only (e.g. 181 fig. 8 correlated sedimentary logs from selected boreholes from central palatine hill (see fig. 2b for location). legend as in fig. 7. fig. 9 -. correlated sedimentary logs from selected boreholes in the eastern palatine hill and oppius hill (see fig. 2b). note the internal facies variability of the fosso del torrino formation (ftr) reflecting intercalation of crevasse sandy deposits within floodplain muds. legend as in fig. 7. stratigraphy of the palatine hill fig. 5 b, c; log 13 ms in fig. 7) at elevation above 5 m a.s.l., suggesting it forms laterally discontinuous bodies up to 5 m thick. interpretation. deposition by sand-laden waning flows in channel margin and levee settings. the levee deposits, particularly well exposed along man-made cuts on the nw flank of the palatine hill (fig. 5b), can be differentiated from channel margin deposits based on vertical association with underlying floodplain deposits (i.e. lithofacies vgu c, see log 13 ms in fig. 7) and presence of pedogenic features. pedogenized floodplain and channel-abandonment silt (vgu c) vgu c consists of pale to dark grey-brown, partly calcite-cemented, massive sandy silt (plate i e; figs. 5 b,d), interbedded with dm-thick beds of detrital freshwater tufa and lignite. as previously described for vgu a and b, the sandy fraction is very rich in volcanic ferromagnesian minerals (clino-pyroxene and biotite). in few localities, well-developed clayey paleosols is found atop vgu c (e.g. log 13 ms, see figs. 5 b and 7) containing: prismatic and angular blocky peds (up to 5 cm long) typical of bt soil horizon (illuvial clay, see retallack, 2001), dark brown cutans (fe/mn oxides), calcium carbonate depleted horizons, root traces and abundant shells of the terrestrial gastropod pomatias elegans. interpretation. this facies derives from suspension and traction-fall out processes, characterized by low energy waning flows related to overbanking in floodplains (log 13 ms in figs. 5 b and 7) and abandoned channels (log 11 ms in fig. 7, plate 1 e). pedogenetic characters suggest the establishment of partly drained and oxidizing conditions. the prismatic and angular blocky peds may, in fact, reflect repeated swelling and shrinking resulting from alternation of wetting-drying conditions (retallack, 2001). coarsening upward facies sequences including interbedded vgu c and vgu b (e.g. log 13 ms in fig. 7; figs. 5 b, c) can be interpreted to reflect lateral shifts of the fluvial system axes resulting in progradation of levees onto floodplain mud (brierly et al., 1997; hornung & aigner, 1999). 4.3.2 palatino unit (pti) the palatino unit is an ignimbrite marker-bed representing the product of a single pyroclastic flow sourced from the alban hills (funiciello & giordano, 2008). it partly corresponds to the “cappellaccio” and “tufo granulare” described by de angelis d’ossat (1956) and yielded a 40ar/39ar age of 528 ± 1 ka (karner et al., 2001) and 520 ± 8 ka (karner & renne, 1998). in the study area pti crops out along the velabro valley (figs. 5a; 6a, b), where intercalates into vgu fluvial deposits. it is represented by a dark grey, massive tuff (figs. 5c-d) with a weakly pedogenized top (fig. 6b; plate ii c), made of an ash matrix with floating crystals (leucite, biotite, clino-pyroxene), black scoriae (plates i f, ii a-c), poorly-rounded lithics (fig. 5e) interpreted as xenoliths (funicello & parotto, 1978), and tree moulds (fig. 5d). at some sites (log 13 ms in fig. 7), the lowermost few cm of pti contains abundant wellrounded fine pebbles of limestone and chert (plate ii b). though occurring at different elevations, pti shows small thickness changes (c. 5 m) suggesting mantling of the pre-existing topography. interpretation. pti character suggest deposition by a high density pyroclastic flow onto an articulated topography including interfluves. the lithic pebbles in the lowermost part of pti (fig. 5e) likely represents clasts ripped up from the channel floor and re-deposited in off-axes locations of the vgl valley (log 13 ms in fig. 7). tree moulds represent casts of burned tree trunks and branches (de rita et al., 2002). 4.3.3 prima porta unit (ppt) the pyroclastic prima porta unit crops out along the western flank of the palatine and the south-eastern flank of the capitoline (figs. 6 a-c), overlaying pti and vgu. it corresponds to the “tufo granulare” pro parte in de angelis d’ossat (1956) and to the “tufo giallo di prima porta” in karner et al. (2001) and luberti et al. (2017). sourced from the sabatini mts volcanic district, this unit yielded 40ar/39ar radiometric ages of 514 ± 3 ka (karner et al., 2001) and 514 ± 6 ka (marra et al., 2014). the outcrop of ppt on the capitoline hill (figs. 6 a, b) was attributed to the fosso del cavaliere unit by de rita & fabbri (2009). in the study area, ppt is represented by greengrey tuffs composed of well-sorted, fine ashes (plate ii c; figs. 6 a-c) with faint planar-parallel lamination, containing scattered sub-centimetric pumice. the top of the unit is marked by a yellowish clayey paleosol with root traces. the unit is composed of two superimposed laterally continuous bodies, each up to 4 m thick, separated by a planar amalgamation surface. observed thickness changes of ppt are very small, suggesting tabular geometry over short lengths. interpretation. ppt can be interpreted as the distal product of two pyroclastic flows, originated from highly fragmented magma of phreato-magmatic origin. planarparallel lamination testifies deposition under upper regime conditions by low-density flows. 4.4 torrino synthem (tno) the torrino synthem (funiciello & giordano, 2008) is correlated with mis 12-11 and pg5 depositional sequence (milli, 1997), and is bounded at the base by the high relief unconformity iii. in the study area tno comprises only the fosso del torrino formation (ftr) and represents the infill of a nw-se (north-eastern hillslope of palatine and fori imperiali) to n-s (eastern hillslope of palatine and labicano valley) (figs. 2 and 10) directed paleovalley (mancini et al., 2013, 2014; moscatelli et al., 2015). 4.4.1 fosso del torrino formation (ftr) the fosso del torrino formation (ftr) is up to 40 m thick and comprises several facies including channel gravel (ftr a) and sand (ftr b), poorly and welldrained floodplain mud (ftr d and f, respectively), buried colluvia (ftr e) and epiclastites (ftr g). this formation partly corresponds to the san cosimato formation (conato et al., 1980) and to the san paolo formation, with the latter reported from the subsoil of the nearby quirinale (marra & rosa, 1995) and capitoline hills (corazza et al., 2004). it is noteworthy that the 182 mancini m. et al. 183 stratigraphy of the palatine hill examples of lithofacies from selected cores (bottoms and tops in the lower left and upper right, respectively; core box is 1 m-long), with main facies boundaries marked in red. a) over-consolidated marine clay of the monte vaticano formation (mva; pliocene) overlain by fluvial channel gravel (ftr a) of fosso del torrino formation (middle pleistocene) in borehole 22 p (depth interval 40-35 m); b) dm-thick cross laminated sands intercalating the clays of mva (detail from core of borehole 8 ms). santa cecilia formation (middle pleistocene): c) channel gravel (cil a) from borehole 2 ms (depth interval 15-10 m) and d) cross-laminated channel sand (cil b) from borehole 16 ms (depth interval 30-25 m). e) the valle giulia formation (middle pleistocene) in borehole 11 ms (dept interval 20-15 m): channel gravel (vgu a) passing upward to channel-abandonment fines of vgu c. note the dark-grey hue of the vgu a sandy matrix, rich in ferromagnesian minerals; f) channel sand of the santa cecilia formation (cil b), overlain by grey overbank sand of vgu b lithofacies and by structureless ignimbrite of the palatino unit (pti; middle pleistocene) from borehole 1 ms (depth-interval 30-25 m). plate i sand of ftr b represents the matrix of a vertebrate fossil assemblage (including elephas antiquus, bos primigenius, cervus elaphus, hippopotamus amphibious) unearthed during the excavation of via dei fori imperiali (de angelis d’ossat, 1956). channel gravel (ftr a) this facies is represented by poorly sorted, coarse -medium gravels in an abundant sandy matrix (plates i a and ii d), frequently intercalated with dm-thick beds of beige cross-laminated sands. clasts are carbonate, chert and tuff lithics, generally well-rounded and bladeshaped. the sandy-silty matrix, reddish to dark grey in colour, is very rich in volcanic ferro-magnesian minerals and chert. ftr a occurs at elevations below -2 m a.s.l., infilling the deepest part of unconformity iii and forming a flat-topped channel-fill body up to 10 m-thick and at least 200 m-wide across. interpretation. ftr a represents a stack of longitudinal bars and bedload sheets infilling the channels of a gravelly-sandy braided river. channel and crevasse-splay sand (ftr b) ftr b is represented by yellow to light brown cross-laminated and through-cross bedded sands with quartz, feldspar and muscovite and volcanic ferromagnesian minerals (augite, biotite, magnetite), interbedded with dm-thick beds of silt (plate ii d; fig. 6d-e). sand and silt are vertically arranged to form meter-thick bed-sets with alternated finingand coarsening-upward patterns (e.g. logs 9 ms, 18 ms and 22 ms on figs. 8 and 9); the coarsening-upward pattern typifies those ftr b bed-sets interbedded as isolated lenses within floodplain mud (ftr d, see below), in the subsurface of the eastern palatine. apart from these lenses, ftr b forms a main depositional body up to 30 m thick, which can be tracked from n to s for at least 500 m where the base of ftr is most deeply incised (roman forum and labicano valley, fig. 4). toward the w, ftr b interfingers with mud-prone floodplain deposits (ftr d). interpretation. bedding pattern, sedimentary structures and large-scale geometry suggest that the main depositional body of ftr b might represent the result of a multistorey-multilateral stack within a fluvial channelbelt, composed of sandy bed-load sheets and bars referred to a mixed bed/suspended-load meandering fluvial system. lenticular ftr b bed-sets within floodplain muds are interpreted as crevasse splay deposits (basilici, 2000). poorly-drained floodplain mud (ftr d) this lithofacies is represented by blue-grey to turquoise structureless clay (plate ii e, f), locally interlayered with cm-thick beds of muscovite-rich very fine silty sands with faint planar-parallel lamination. pale grey to yellowish mottles and white-yellow small micritic carbonate nodules (plate ii e) are commonly observed in the clays, especially in the lower part of ftr d (logs 22 p and 9 ms; fig. 9). plant debris is scattered throughout the upper part of ftr d but is particularly abundant at about 20 m a.s.l., forming laterally continuous lignite seams traceable across adjacent boreholes (fig. 8; plate ii f). this lithofacies is up to 25 m thick and can be traced laterally for at least 300 m in the subsoil of the eastern portion of the palatine, before it passes laterally to ftr b northand east-ward. interpretation. lateral association with channel facies suggests that ftr d represents the product of suspension fall-out and, subordinately, traction-fall out deposition by repeated overbanking in a floodplain environment (davies & gibling, 2003; north & davidson, 2012). structureless mud may represent the deposit of either a shallow flood-basin ponds or distal floodplain setting (cfr with fm lithofacies of miall, 1996), whereas thin sand/ mud alternations might reflect weak tractional waning flows in more proximal setting (cfr facies fl by miall, 1996, and lithofacies association sl by ghinassi et al., 2005). the abundance and preservation of plant fragments suggests waterlogged conditions typical of poorly drained floodplain, which might have favoured lignite seams formation via accumulation of reotrophic peat in low-lying swamps (mc cabe, 1984; fielding, 1985). conversely, mottles and carbonate nodules are pedogenic hydromorphic features (gleying) best interpreted to reflect ground-water oscillations (kraus & aslan, 1993) in a partially waterlogged environment. colluvium (ftr e) this facies consists of yellow-brown to grey, poorly sorted and massive silt and fine sand with abundant tuff fragments and ferro-magnesian minerals. it fills two swne trending gullies underneath the domus tiberiana (fig. 4) cutting older pyroclastic rocks. interpretation. ftr e is interpreted as the deposit of multiple gravity-driven mass flows along the flanks of local gullies. well-drained floodplain mud (ftr f) this facies is composed of pale yellow to brown, structureless silty clay with cm-scale sub-spherical iron oxides mottles, calcium carbonate concretions and root traces, intercalated with planar-parallel laminated silts and sands with a typical yellow-reddish hue (plates ii f, iii a-d). particularly noteworthy are two cm-thick tephra occurring in the uppermost part of ftr f (logs 2 a and 3 a in fig. 9; plate iii b). interpretation. as previously discussed for similar mudprone facies, ftr f reflects floodplain deposition. widespread oxidation and pedogenic elements, such as mottles, glaebules and root traces (davis & gibling, 2003) would testify more drained conditions compared to the underlaying ftr d. epiclastite (ftr g) this is a crudely stratified heterometric deposit with coarse-tail normal grading, composed of coarse sand and very fine poorly rounded pebbles (fig. 6c; plate iii a) in a silty matrix with a dark yellow to brown hue. clast composition comprises abundant pyroclastic material with ferro-magnesian juvenile crystals and a range of juvenile to accidental lapilli, including fragmented clasts of violaceous-reddish un-welded ash (pozzolan), chert and carbonate. ftr g intercalates to ftr f facies (figs 8 and 9) forming an up to 4.5 m thick body with a sharp, but not erosive base and a pedogenically modified top, which contains root traces, mottles and terrestrial gastropods (vallonia sp.). interpretation. the features of ftr g, along with its 184 mancini m. et al. 185 stratigraphy of the palatine hill examples of lithofacies from selected cores (bottoms and tops in the lower left and upper right, respectively; core box is 1 m-long), with main facies boundaries marked in red. a) the palatino unit (pti) ignimbrite interbedded to the fluvial channel gravels of the valle giulia formation (vgu a) from borehole 11 ms (depth interval 25-20 m). b) very fine-to-fine limestone well-rounded pebbles embedded within the lowermost part of the palatino unit (pti) and the overlaying ripple-drift laminated levee sand (vgu b) of the valle giulia formation from borehole 13 ms (depth interval 13-15 m). these pebbles occur mostly in off-valley axis settings and are interpreted to reflect entrainment of fluvial deposits by the pti pyroclastic flow from the substrate. c) green-grey, faintly laminated pyroclastic deposit of the prima porta unit (ppt; middle pleistocene), overlaying the dark-grey pti ignimbrite in borehole 16 ms (depth interval 20-15 m). fosso del torrino formation (middle pleistocene): d) channel gravel (ftr a) with heterometric pebbles in an abundant sandy matrix overlain by cross-laminated fluvial sand of ftr b lithofacies from borehole 22 p (depth 35-30 m); e) pale grey, structureless, silty clay with sparse carbonate nodule (red arrow) interpretable as poorly drained floodplain deposit (ftr d) from borehole 22 p (depth interval 25-20 m); f) blue-grey, structureless, organic-rich clay with a lignite seam on the top interpretable as the deposit of poorly drained flooplain (ftr d) followed upward by yellowish clayey deposits of a well-drained floodplain (ftr f) in borehole 9 ms (depth interval 30-25 m). plate ii association with ftr f, suggest deposition by massive, hyper-concentrated and out-of-channel flows (north & davidson, 2012) in floodplain environment. the clast composition, dominated by volcanic particles, suggests a synto slightly post-eruptive epiclastic origin, as well as en-route entrainment of fluvial pebbles from the substrate. 4.5 quartaccio synthem (qta) the quartaccio synthem (funiciello & giordano, 2008) is correlated with mis 10-9 and the pg6 depositional sequence (milli, 1997). in the study area it corresponds to the pyroclastic villa senni formation tufo lionato ignimbrite (vsn1) and to the overlaying fluvial aurelia formation (ael). the quartaccio synthem is bounded at the base by the iv unconformity, recording the sea level fall occurred between mis 11 and mis 10. this surface, corresponding to the base of the villa senni formation tufo lionato ignimbrite (vsn1), is flat on top of the palatine hill and deeply incised in the nearby capitoline hill. 4.5.1 villa senni formation, tufo lionato (vsn1) the tufo lionato is an ignimbrite sourced from the alban hills (de rita et al., 1995; watkins et al., 2002; giordano et al., 2006; giordano and the carg team, 2010) which belongs to the villa senni formation and was 40ar/39ar dated to 355 ± 2 ka using samples from the palatine outcrops (karner & renne, 1998; karner et al., 2001). well-exposed along the velabro valley (figs. 6 a, c), vsn1 is a dark red-orange, massive tuff (figs. 7 -9; plate iii c;) with an ash matrix and sparse crystals (leucite, biotite, clino-pyroxene), lithics (small and rare limestone clasts), and grey to black scoriae, and locally with columnar gas escape pipes up to 40-50 cm long and a few centimeters wide (fig. 6 f). the deposit may be either welded (vsn 1a) as a result of cementation by zeolite minerals or un-welded (vsn 1b), consisting of scoriaceous reddish to dark grey pozzolan (plate iii d). locally, an up to 50 cm thick bed of lapilli occurs below the tuff suggesting that the ignimbrite was preceded by the fall-out of lapilli (plate iii c; logs 14 ms, 9 ms and 3 a, in figs. 8 and 9). tabular with flat base and mean thickness of c. 10 m on the palatine hill top and the orographic left of the velabro valley, the vsn1 rapidly thickens to up to 45 m in the subsurface of the capitoline hill (alvarez et al., 1996; corazza et al., 2004) suggesting it partially fills a ne-sw trending incised valley (see also cross section 1 on fig. 4; fig. 7). interpretation. deposition of a large volume, very hot and dense pyroclastic flow, infilling the pre-existing topography. large-scale geometry suggests the presence of a fluvial paleovalley, located nw of the capitoline hill, related to the quartaccio synthem (fig. 10) and flanked by to the southeast by an interfluve (the present-day palatine hill) superelevated by at least 20 m above the valley floor. 4.5.2 aurelia formation (ael) in the study area this unit (cfr. with the formazione fluvio-lacustre of de angelis d’ossat, 1956) crops out limitedly to the palatino and capitolino hilltop and is represented by a few metres of pale yellow clayey silt with a range of pedogenic features. these include mottles, orange-red fe3+ oxides cutans, sparse subspheroidal carbonate nodules, root traces and caco3depleted horizons (plate iii d). interpretation. ael sediments exposed on the palatine hilltop might represent floodplain mud-prone deposits which have undergone intense pedogenization and illuvial clay enrichment under highly oxidizing conditions. 4.6 fiume tevere synthem (sft) the post-volcanic fiume tevere synthem (funiciello & giordano, 2008) is correlated with mis 5d1 and the pg9 depositional sequence (milli, 1997; tiber depositional sequence of milli et al., 2016). it comprises only the alluvial deposits (sftba) sensu funiciello & giordano (2008), and is bounded at the base by the deeply incised v unconformity, recording the last glacioeustatic sea level fall (mis 5dmis 2). in the study area, the alluvial deposits (sftba) mainly consists of poorly consolidated fine-grained sediments forming the upper pleistocene-holocene (mis 21) infill of the left-bank tributary valleys of the tiber river, namely the velabro, murcia and labicano valleys (bozzano et al., 1995; ammerman et al., 2000; campolunghi et al., 2007; carpentieri et al., 2015; marra et al., 2018). gravel lag (sftba a) this facies is represented by sub-angular to wellrounded very fine to medium pebbles (plate iii e) of limestone, chert and tuff in an abundant dark grey silty sandy matrix rich in ferro-magnesian minerals and plant fragments. interpretation. sftba a forms a coarse basal lag up to about 5 m thick infilling the lower part of the tiber tributary paleovalleys. it represents an early-stage deposit resulting from local erosion and deposition of older gravelly-sandy deposits (e.g. cil a-b, vgu a-b and ftr ab) cut by unconformity v. channel sand (sftba b) this facies is comprised of grey to brown, finemedium silty sands, with quartz, feldspar, muscovite, ferro-magnesian minerals of volcanic origin and scattered peat fragments. sftba b forms lens-shaped bodies up to 8-10 m thick and less than 100 m wide, which pass laterally to mud-prone deposits of facies sftba df (see below). interpretation. sftba b can be interpreted as a channel-fill deposit of streams with a sandy bed-load. organic-rich mud (sftba d) this facies represents most of the infill of sft paleovalleys reaching thickness up to 35 m (e.g. murcia valley, fig. 4). it is composed of dark grey, structureless silty clay (plate iii f), typically plastic and poorly consolidated, interbedded with cm-thick beds of sand compositionally similar to sftba b. the dark grey hue is imparted by the abundance of plant fragments, which in some cases can be concentrated to form dm-thick peat layers. interpretation. sftba d reflects fall-out and, subordinately, traction-fall deposition by fluvial overbanking in an undrained floodplain environment with ponds and 186 mancini m. et al. 187 stratigraphy of the palatine hill examples of lithofacies from selected cores (bottoms and tops in the lower left and upper right, respectively; core box is 1 m-long), with main facies boundaries marked in red. a) the fosso del torrino formation (middle pleistocene): pale yellow, faintly laminated sandy silt (ftr f) interpreted as a well-drained floodplain deposit, interbedded with grey-brown, reworked coarse pyroclastic sand (ftr g) (borehole 9 ms, depth interval 20-15 m). b) detail of a tephra layer from ftr f (borehole 3 a; depth 16.40 m). c) villa senni formation tufo lionato (middle pleistocene): orange-red massive ignimbrite (vsn 1a) with a 40 cm thick basal fallout deposit, composed of dark grey lapilli and coarse ashes. vsn 1a covers overbank silt (ftr f) of the fosso torrino formation (borehole 9 ms; depth interval 15-10 m); d) villa senni formation tufo lionato: reddish pozolan (vsn 1b) overlaying ftr f. vsn 1b is in turn overlain by yellowish, intensely pedogenized clay of the aurelia formation (ael; middle pleistocene) and by anthropogenic landfill material (h) (borehole 2 a; dept interval 15-10 m). e) fiume tevere synthem alluvial deposits (late pleistocene-holocene): dark brown-grey, sandy rich, very fine to fine pebbles of sftba a overlaying the sand of the fosso del torrino formation (ftr b) in borehole 18 p (depth interval 25-20 m); f) fiume tevere synthem alluvial deposits: grey, organic-rich, poorly drained floodplain mud (sftba d lithofacies), overlain by pale brown, pedogenized sandy silt (sftba f) in borehole 18 p (depth interval 20-15 m). plate iii marshes. pedogenically modified mud (sftba f) this facies can be differentiated by sftba d based on its stiffness, its reddish to dark brown-hue and mottled texture reflecting oxidization of abundant plant fragments (plate iii f). at some sites, scattered finepebble sized clasts of limestone and brick fragments are found embedded within the topmost part of sftba f, witnessing man-made excavation and dumping of landfill materials, likely from roman times. interpretation. sftba f is widespread within sft paleovalleys, forming a laterally continuous body up to 7 m thick overlaying sftba d. it can be interpreted to reflect overbank deposition in a drained floodplain environment subject to intense root mottling and pedogenization. 4.7 anthropogenic cover (h) this unit is represented by an almost continuous layer of backfill material (lithofacies hb), and remnants of buildings (lithofacies hm) from the roman age, reaching maximum thickness of 15-20 m. the backfill (hb) is constituted by sand-pebble sized clasts in a silty-clayey matrix of pozzolanic composition, while masonry (hm) is mainly composed by hard concrete and rocky blocks (travertine, lava rocks, marble, etc.). the anthropogenic layer mantles the pre-existing morphology and reaches its maximum thickness in correspondence of buried valleys (moscatelli et al., 2014b). 5. discussion owing to the availability of numerous subsoil investigations carried out over the last few decades mostly for archeological, geotechnical and cultural heritage preservation purposes (de angelis d’ossat, 1956; alvarez et al., 1996; corazza et al., 2004; cecchi, 2011; moscatelli et al., 2012; calabresi et al., 2013; mancini et al., 2014), the palatine hill represents a key site for unfolding the stratigraphic architecture of the volcanosedimentary succession of the rome basin (conato et al., 1980; milli, 1997; karner & marra, 1998; marra et al., 1998, 2008, 2016; giordano et al., 2003; milli et al., 2008; marra & florindo, 2014; luberti et al., 2017, among the others). based on a few classical and wellstudied outcrops (figs. 5 and 6 a, b; see also marra & rosa, 1995; corazza et al., 2004; de rita et al., 2002; de rita & fabbri, 2009), temporary outcrops from archeological excavation and construction sites (figs. 6 ce) and selected boreholes recently drilled in the study area (figs. 7-9), this contribution is aimed at describing the sedimentary facies making up the infills of multiple incised paleovalleys (sensu blum et al., 2013) of the tiber river, developed in response to the middle pleistocene to holocene high-frequency sea level fluctuations affecting the rome basin. the following discussion aims to: 1) show the significance of the palatine hill case study as a depositional analogue for paleovalley development, and 2) comment best practices in geology of urban areas. 5.1 the palatine hill as an analogue for paleovalley development the paleovalley infills preserved in the subsurface of the palatine hill and surrounding areas correspond to some of the synthems introduced by funicello & giordano (2008), namely, from older to younger the flaminia (lmn), villa glori (vgl), torrino (tno), quartaccio (qta) and fiume tevere (sft) synthems. in the study area, the flaminia synthem (lmn; mis 16-15) is characterized by a rather flat basal unconformity (unconformity i), tabular geometry and a finingupward infill represented by the fluvial santa cecilia formation, made of channel gravel (cil a) and sand (cil b) and deposited by a braided river with a coarse bed load. along with the underlying marine sediment of the monte vaticano formation (mva), the flaminia synthem represents the substrate into which younger paleovalleys developed. basing on its almost tabular geometry and stacking of facies, the santa cecilia formation (cil) can be interpreted as a “stacked channel sheet with smooth or near-smooth basal unconformity”, following the valley architectures classification by holbrook (2001). to the east of the study area, however, the cil thickness increases rapidly and its top deepens, suggesting synto postdepositional extensional tectonics controlling locally the basin infill (funicello & giordano, 2008). the villa glori (vgl) and torrino (tno) synthems are by far the best-preserved paleovalley infills documented in the palatine hill subsurface. these show a nw-se to n-s trend (fig. 10), high-relief basal unconformities (unconformities ii and iii) and a common facies motif with a lower gravelly facies grading upward into a suite of channelized sands, channel abandonment fines and floodplain muds. this facies architecture that indicates valley incision was followed by the establishment of an entrenched gravelly braided fluvial system, evolving upward into a mixed, sandy-muddy suspended-load and bed-load river (i.e. channel-levee sands and silt) with laterally continuous and well-developed floodplains (i.e. mud-prone facies). notably, tough partly cannibalized by the younger tno, vgl (mis 14-13) represents a particularly valuable example for constraining the likely morphology of the studied paleovalleys, in that its fluvial infill (the valle giulia fm. vgu) is intercalated by ignimbrites from large volume catastrophic pyroclastic flows (the palatino and prima porta units, pti and ppt) capable of blanking the topography and providing a snapshot of relative location of coeval depositional elements. in fact, for example, the pti ignimbrite covered both the active channel and levee-floodplain belt (logs ms 13 and ms 11, in fig. 7), and was later incised by the re-established active fluvial channel, represented by facies vgu a above pti (fig. 7). a full record of paleovalley morphology and infill development is provided by tno (mis 12-11). the excellent preservation of the dominantly fluvial fosso del torrino fm. (ftr) allows confidently tracking: 1) the stratigraphic replacement of a lower gravel-prone early stage-fill (ftr a) by a sandy multi-storey channel belt fill (i.e. the main depositional body of facies ftr b) along the paleovalley axis (fig. 10); 2) the evolving relation 188 mancini m. et al. ship between the active channel belt and coeval floodplains. regarding the latter aspect, it can be noted how, over most of the paleovalley infill thickness, floodplain muds are intercalated with hydromorphic paleosols suggesting waterlogged conditions (ftr d), whereas in the uppermost ftr they contain oxidized paleosols (ftr f). this stratigraphic and pedogenetic change from poorlyto well-drained floodplains may be interpreted as a progressive lowering of the groundwater table, which can be explained by incipient channel re-incision of floodplain under a general decrease of rate of floodplain accommodation (wright & marriot, 1993; miall, 2014). moreover, in the uppermost ftr the widespread presence of out-of-channel epiclastites (ftr g) and tephra testifies active syn-volcanic alluvial sedimentation. the tephra horizons preserved within the upper floodplain deposits (plate iii b; fig. 9) might correlate to the tephra reported by marra et al. (2016) as part of the san paolo fm. (i.e. fosso del torrino fm.) from the subsurface of the nearby capitoline hill. a sanidine sample (spqr-51sample) from the capitoline tephra was 40ar/39ar dated 416 ± 11 ka (karner & renne, 1998; karner et al., 2001) suggesting a correlation with the vico α horizon sourced from the vico volcanic district of northern latium (luberti et al., 2017) and thus providing important constrain on timing of development of the ftr paleovalley infill. the study area provides only a partial view of the quartaccio synthem (qta, mis 10-9; fig. 10). nonetheless, the geometry and facies character of the pyroclastic villa senni formation-tufo lionato (vsn1) and the aurelia formation (ael) agree with a river system, and the corresponding paleovalley, located to the nw of the capitoline hill (alvarez et al., 1996; corazza et al., 2004), which delivered fines to a left-bank floodplain (i.e. ael) occupying the palatine hill area. if the likely location of the paleovalleys documented in the subsurface of the palatine hill and surrounding areas is compared (fig. 10), a progressive westward shift of the river sys 189 fig. 10 paleogeographic sketch map of the palatine area showing axes and margins of the main buried paleovalleys (modified and adapted after alvarez et al., 1996, and mancini et al., 2014). stratigraphy of the palatine hill tem is apparent starting from tno to qta which may reflect the interplay of the long-term regional tectonic uplift of the western periphery of the central apennines (milli, 1997; giordano et al., 2003; marra et al., 2008; milli et al., 2008; mancini et al., 2013) and the input of volcanic products from the alban hills in subtracting accommodation space to the tiber river fluvial system. one last observation can be made about the significance of the fiume tevere synthem (sft; mis 5d-1) present in the study area, representing the infills of the left-bank velabro and murcia tributary paleovalleys of the tiber river. compared to previously addressed examples, which refer to the ancient main trunk paleovalleys (vgl, tno, qta), the velabro and murcia paleovalley infills are initiated by coarse and poorly organized lags deposited by gravitative processes (facies sftba a), contain a much greater proportion of pedogenized, organic-rich fines (sftba d-f) and appear to be deficient of channel sand (sftba b). this contrasting architecture of tributary vs. trunk paleovalley of the tiber, much richer in channel-belt deposits (see also milli et al., 2016), can be interpreted to reflect the fact that the higher rate of aggradation of the tiber river valley with respect to surrounding areas might have resulted in “passive” backfilling of lateral valleys. 5.2 methodological remarks on urban geosciences finally two aspects concerning the best practice on urban geosciences can be considered, which derive from the present research: 1) the extensive use of photographic illustration for core facies analysis; 2) the documentation of temporary outcrops. on the first aspect, the photographic depiction of cores is well recommended for describing facies of quaternary units within fluvial and urban contexts (amorosi 2006; sarti et al., 2012), and can significantly contribute to solve potential gaps of knowledge on local stratigraphy. however, within the rich scientific literature on the rome basin stratigraphy (luberti et al., 2017, with references) only few examples do exist of core data reported through photographic pictures (marra & florindo, 2014; martino et al., 2015; milli et al., 2016). in our opinion, the core data here illustrated (plates i-iii) can be potentially used as useful reference and comparison material for subsoil reconstructions of nearby areas. the occurrence of temporary shortly-exposed outcrops, related to in-progress city works such as subway construction and archeological excavations, is well documented in this article (figs. 6 c-e). their observation, description and correlation with other field and subsoil data should be emphasized. in fact, the integration of temporary outcrops with other data can be useful for anchoring unsolved stratigraphic reconstructions in densely urbanized contexts, where the widespread presence of pervious surfaces usually impedes the observation of natural outcrops, and where available cores may be insufficient, in some cases, to provide a complete picture of the subsoil. this is particularly true in the ancient historical center of rome, where the anthropogenic modifications and a thick layer of anthropic backfill (moscatelli et al., 2014 b; ciotoli et al., 2015) often prevents detailed palaeo-environmental reconstructions based only on the terrain morphology observation. 6. conclusion the facies analysis of core and outcrop data has allowed to reconstruct with great detail the stratigraphic architecture of the palatine hill. this architecture is represented by a series of nested paleovalley infills related to the tiber river system and encompassing middle pleistocene to holocene intervals (mis 16-9 and mis 21 intervals) of fluvial sedimentation and distal pyroclastic deposition. the paleogeography of the most relevant paleo-valleys, as reconstructed from the present study, can be related to external forcing as uplift, pyroclastic supply and fluvial response to glacio-eustatic changes, as well as to internal reorganization of the fluvial system, which deserve to be investigated on a wider area. nevertheless, thanks to its well detailed stratigraphic reconstruction the palatine can be considered a key area for better understanding trends, characters and continuity of fluvial paleo-valleys within the whole rome basin. acknowlegements the authors thank the reviewers and editors for useful comments and suggestions. references alvarez w., ammerman a.j., renne p.r., karner d.b., terrenato n., montanari a. (1996) quaternary fluvial-volcanic stratigraphy and geochronology of the capitoline hill in rome. geology, 24, 751-754. ammerman a.j., miller j., ramsay s. (2000) the midholocene environment of the velabrum in rome. società preistoria protostoria del friuli venezia giulia, quaderno 8, 9-20. amorosi a. (2006) reading late quaternary stratigraphy from cores: a practical approach to facies interpretation. geoacta, 5, 61-78. amorosi a., bini m., giacomelli s., pappalardo m., ribeai c., rossi v., sammartino i., sarti g. (2013) middle to late holocene environmental evolution of the pisa coastal plain (tuscany, italy) and early human settlements. quaternary international, 303, 93-106. doi: 10.1016/j.quatint.2013.03.030 basilici g. (2000) floodplain lake deposits on an early pleistocene alluvial plain (tiberino basin, central italy). in: gierloski-kordesh e.h., kelts k.r. (eds.) lake basins through space and time, aapg studies in geology 46, 535-542. blum m., martin j., milliken k., garvin m. (2013) paleovalley systems: insights form quaternary analogs and experiments. earth-science reviews, 116, 128-169. bozzano f., funiciello r., marra f., rovelli a., valentini g. (1995) il sottosuolo dell’area dell’anfiteatro flavio in roma. geologia applicata e idrogeologia, 30(1), 405-422. bozzano f, andreucci a, gaeta m, salucci r (2000) a geological model of the buried tiber river valley beneath the historical centre of rome. bulletin of engineering geology and the environment, 59, 12. bridgland d.r., harding p., allen p., candy i., cherry 190 mancini m. et al. c., george w., horne d.j., keen d.h., penkman k.e.h., preece r.c., rhodes e.j., scaife r., schreve d.c., schwenninger j.l., slipper i., ward g.r., white m.j., white t.s., whittaker j.e. (2013) an enhanced record of mis 9 environments, geochronology and geoarchaeology: data from construction of the high speed 1 (londonchannel tunnel) rail-link and other recent investigations at purfleet, essex, uk. proceedings of the geologists' association, 124 (3), 417-476. doi: 10.1016/j.pgeola.2012.03.006 brierly g.j., ferguson r.j., woolfe k.j. (1997) what is a fluvial levee? sedimentary geology, 114, 1-9. brocato p., terrenato n. (2016) nuovi studi sulla regia di roma. luigi pellegrini editore, cosenza (italy), pp. 185. calabresi g., cavalera l., ascoli marchetti v., filetici m.g. (2013) geotechnical aspects in the preservation of the domus tiberiana. in: bilotta e., flora a., lirer s., viggiani c. (eds.) geotechnical engineering for the preservation of monuments and historic sites, taylor & francis group, london, 207-213. campolunghi, m.p., capelli, g., funiciello, r., lanzini, m. (2007) geotechnical studies for foundation settlement in holocenic alluvial deposits in the city of rome (italy). engineering geology, 89 (1-2), 935. carpentieri e., de rita d., della monica g. (2015) geology of the murcia valley and flood plain modifications in the construction of the circus maximus, rome, italy. geoarchaeology, 30(6), 483494. castagnoli f. (1980) topografia di roma antica. società editrice internazionale, pp. 119. cavinato g.p., de celles p.g. (1999) extensional basins in the tectonically bimodal central apennines fold-thrust belt, italy: response to corner flow above a subducting slab in retrograde motion. geology, 27, 955-958. cecchi r. (2011) roma archaeologia. interventi per la tutela e la fruizione del patrimonio archeologico. terzo rapporto, volume secondo. electa, pp. 632. ciotoli g., stigliano f., mancini m., marconi f., moscatelli m., cavinato g.p. (2015) geostatistical interpolators for the estimation of the geometry of anthropogenic deposits in rome (italy) and related physical-mechanical characterization with implications on geohazard assessment. environmental earth sciences, 74 (3), 2635-2658. doi: 10.1007/s12665-015-4284-z conato v., esu d., malatesta a., zarlenga f. (1980) new data on the pleistocene of rome. quaternaria 22, 131-176. corazza a., lombardi l., marra f. (2004) geologia, idrogeologia e approvvigionamento idrico del colle capitolino (roma, italia). il quaternario/italian journal of quaternary sciences, 17 (2/2), 413441. cosentino d., cipollari p., di bella l., esposito a., faranda c., giordano g., mattei m., mazzini i., porreca m., funiciello r. (2009) tectonics, sealevel changes and paleoenvironments in the early pleistocene of rome (italy). quaternary research 72(1), 143-155. doi: 10.1016/j.yqres.2009.03.003 davies s.j., gibling m.r. (2003) architecture of coastal and alluvial deposits in an extensional basin: the carboniferous joggins formation of eastern canada. sedimentology, 50, 415-439. de angelis d’ossat g. (1956) geologia del colle palatino in roma. memorie descrittive della carta geologica d’italia, 32, 4-95. del monte, m., d'orefice, m., luberti, g.m., marini, r., pica, a., vergari, f. (2016) geomorphological classification of urban landscapes: the case study of rome (italy). journal of maps 12(1), 178-189. doi: 10.1080/17445647.2016.1187977. de rita d., fabbri m. (2009) the rupe tarpea: the role of the geology in one of the most important monuments of roma. memorie descrittive della carta geologica d’italia, 87, 53-62. de rita d., faccenna c., funiciello r., rosa c. (1995). stratigraphy and volcano-tectonics. in: trigila, r. (ed.) the volcano of the alban hills. tipografica, s.g.s., rome, 33-71. de rita d., giordano g., esposito a., fabbri m., rodani s. (2002) large volume phreatomagmatic ignimbrites from the colli albani volcano (middle pleistocene, italy). journal of volcanology and geothermal research, 118 (1-2), 77-98. doi: 10.1016/s0377-0273(02)00251-2 ellison r.a., woods m.a., allen d.j., forster a., pharoah t.c., king c. (2004) geology of london. memoir of the british geological survey, sheets 256 (north london), 257 (romford), 279 (south london) and 271 (dartford) (england and wales), pp. 114. fielding c.r. (1985) coal deposition models and the distinction between alluvial and delta plain environments. sedimentary geology, 42, 41-48. florindo f., karner d.b., marra f., renne p.r., roberts a.p., weaver r. (2007) radioisotopic age constraints for galcial terminations ix and vii from aggradational sections of the tiber river delta in rome, italy. earth and planetary science letters, 256, 61-80. doi:10.1016/j.epsl.2007.01.014. florindo f., marra f. (1995) a revision of the stratigraphy for the middle pleistocene continental deposits of rome (central italy): paleomagnetic data. annali di geofisica, 38 (2), 177-188. funiciello r., heiken g., de rita d., parotto m. (2006) i sette colli. guida geologica a una roma mai vista. raffaello cortina editore, milano, pp. 328. funiciello r., giordano g. (2008) note illustrative della carta geologica d’italia alla scala 1:50.000. foglio 374 roma. apat, dipartimento difesa del suolo, servizio geoogico d’italia, pp. 158. funiciello r., giordano g. (2010) the colli albani volcano. iavcei, spec. publ. 3. geological society, london, pp. 392. funiciello r., parotto m. (1978). il substrato sedimentario dei colli albani: considerazioni geodinamiche e paleogeografiche sul margine tirrenico dell’appennino centrale. geologica romana, 17, 191 stratigraphy of the palatine hill 233-287. ghinassi m., abbazzi l., esu d., gaudant j., girotti o. (2005) facies analysis, stratigraphy and paleontology (molluscs and vertebrates) in the upper pliocene sandy flood-basin deposits of the upper valdarno basin (northern apennines). rivista italiana di paleontologia e stratigrafia, 111(3), 467 -487. giordano g., esposito a., de rita d., fabbri m., mazzini i., trigari a., rosa c., funiciello r. (2003) the sedimentation along the roman coast between middle and upper pleistocene: the interplay of eustatism, tectonics and volcanism. new data and review. il quaternario, 16, 121-129. giordano g., de benedetti a.a., diana a., diano g., gaudioso f., marasco f., miceli m., mollo s., cas r.a.f., funiciello r. (2006) the colli albani mafic caldera (roma, italy): stratigraphy, structure and petrology. journal of volcanolology and geoterhmal research, 155, 49-80. giordano g., mazza r. (2010) the geology of rome and urban areas: the legacy of prof. renato funiciello. in: beltrando m., peccerillo a., mattei m., conticelli s., doglioni c. (eds) the geology of italy; tectonics and life along plate margins. journal of the virtual explorer 36, paper 28. doi: 10.3809/jvirtex.2010.00277 giordano g. & the carg team (2010) stratigraphy, volcano tectonics and evolution of the colli albani volcanic field. in: funiciello r. & giordano g. (eds.). the colli albano volcano, iavcei spec. publ. 3, 43-97. geological society, london. heiken g., funiciello r., de rita d. (2005) the seven hills of rome. a geological tour of the eternal city. princeton university press, pp. 245. holbrook j. (2001) origin, genetic interrelationships, and stratigraphy over the continuum of fluvial channel-form bounding surfaces: an illustration from middle cretaceous strata, southestern colorado. sedimentary geology, 144, 179-222. hornung j., aigner t. (1999) reservoir and aquifer characterization of fluvial architectural elements: stuben-sandstein, upper triassic, southwest germany. sedimentary geology, 129, 215-280. karner d.b., marra f. (1998) correlation of fluviodeltaic aggradational sections with glacial climate history: a revision of the pleistocene stratigraphy of rome. geol. soc. am. bull., 110, 748-758. karner d.b., marra f., renne p.r. (2001) the history of the monti sabatini and alban hills volcanoes: groundwork for assessing volcani-tectonic hazards for rome. journal of volcanology and geothermal research, 107, 185-219. karner d.b., renne p.r. (1998) 40ar/39ar geochronology of roman volcanic province tephra in the tiber river valley: age calibration of middle pleistocene sea-level changes. geological society of america bulletin, 110, 740-747. kraus m.j., aslan a. (1993) eocene hydromorphic paleosols: significance for interpreting ancient floodplain processes. journal of sedimentary petrology, 63 (3), 453-463. lanzini m. (2008) scheda n. 22. la collina velia in via dei fori imperiali. geosito urbano perduto. in: fabbri m., lanzini m., mancinella d., succhiarelli c. (eds.), 2014. i geositi del territorio di roma capitale. geologia dell’ambiente suppl. n. 3/2014. leone r., margiotta a., betti f., d’amelio a.m. (2009) via dell’impero. demolizioni e scavi. fotografie 1930/1943. electa, milano, pp. 350. luberti g.m., marra f., florindo f. (2017) a review of the stratigraphy of rome (italy) according to geochronologically and paleomagnetically constrained aggradational successions, glacio-eustatic forcing and volcano-tectonic processes. quaternary international, 438, 40-67. doi: 10.1016/j.quaint.2017.01.044 mancini m., moscatelli m., stigliano f., cavinato g.p., marini m., pagliaroli a., simionato m. (2013) fluvial facies and stratigraphic architecture of middle pleistocene incised valleys from the subsoil of rome (italy). journal of mediterranean earth sciences, special issue, 89-93. mancini m., marini m., moscatelli m., pagliaroli a., stigliano f., di salvo c., simionato m., cavinato g.p., corazza a. (2014) a physical stratigraphy model for seismic microzonation of the central archaeological area of rome (italy). bulletin of earthquake engineering, 12, 1339-1363. doi: 10.1007/s10518-014-9584-2 marini m., felletti f., beretta g. p. terrenghi j. (2018) three geostatistical methods for hydrofacies simulation ranked using a large borehole lithology dataset from the venice hinterland (ne italy). water, 10(7), 844, 1-23. doi: 10.3390/w10070844 marra f., florindo f. (2014) -. the subsurface geology of rome: sedimentary processes, sea-level changes and astronomical forcing. earth sci. rev. 136, 1-20. marra f., rosa c. (1995) stratigrafia e assetto geologico dell’area romana. in: funiciello r. (ed.) la geologia di roma. il centro storico. memorie descrittive della carta geologica d’italia, 50, 49-118. marra f., rosa c., de rita d., funiciello r. (1998) stratigraphic and tectonic features of the middle pleistocene sedimentary and volcanic deposits in the area of rome (italy). quaternary international, 47, 51-63 marra f., florindo f., boschi e. (2008) history of glacial terminations from the tiber river, rome: insights into glacial forcing mechanisms. paleoceanography 23. doi:10.1029/2007pa001543 marra f., karner d.b., freda c., gaeta m., renne p. (2009) large mafic eruptions at alban hills volcanic district (central italy): chronostratigraphy, petrography and eruptive behavior. journal of volcanology and geothermal research, 179, 217232. doi: 10.1016/j.jvolgeores.2008.11.009 marra f., sottili g., gaeta m., giaccio b., jicha b., masotta m., palladino d.m., deocampo d. (2014) major explosive activity in the sabatini volcanic district (central italy) over the 800-390 ka interval: geochronological geochemical overview and 192 mancini m. et al. tephrostratigraphic implications. quaternary science reviews, 94, 74-101. doi: 10.1016/j.quascirev.2014.04.010 marra f., rohling e.j., florindo f., jicha b., nomade s., pereira a., renne p.r. (2016) independent 40ar/39ar and 14c age constraints on the last five glacial terminations from the aggradational successions of the tiber river, rome (italy). earth and planetary science letters 449, 105-117. doi: 10.1016/j.epsl.2016.05.037 marra f., motta l., brock a.l., macrì p., florindo f., sadori l., et al. (2018) rome in its setting. postglacial aggradation history of the tiber river alluvial deposits and tectonic origin of the tiber island. plos one 13(3), e0194838. martino s., lenti l., gélis c., giacomi a.c., santisi d’avila m.p., bonilla l.f., bozzano f., semblat j.f. (2015) influence of lateral heterogeneities on strong-motion shear strains: simulations in the historical center of rome (italy). bulletin of the seismological society of america, 105 (5), 26042624. doi: 10.1785/0120140180 mattei m., conticelli s., giordano g. (2010) the tyrrhenian margin geological setting: from the apennine orogeny to the k-rich volcanism. in: funiciello r. & giordano g. (eds.). the colli albano volcano, iavcei, spec. publ. 3, 7-27. geological society, london. mc cabe p.j. (1984) depositional environments of coal and coal-bearing strata. in: rahmani r.a., flores r.m. (eds.) sedimentology of coal and coal-bearing sequences. ias spec. publ. 7, 1342. miall a.d. (1996) the geology of fluvial deposits. sedimentary facies, basin analysis, and petroleum geology. springer, pp. 582. miall a.d. (2014) fluvial depositional systems. springer, pp. 316. milli s. (1997) depositional setting and high-frequency sequence stratigraphy of the middle-upper pleistocene to holocene deposits of the roman basin. geologica romana, 33, 99-136. milli s., moscatelli m., palombo m.r., parlagreco l., paciucci m. (2008) incised-valleys, their filling and mammal fossil record: a case study from middle-upper pleistocene deposits of the roman basin (latium, italy). geoacta, spec. publ. 1, 6788. milli s., mancini m., moscatelli m., stigliano f., marini m., cavinato g.p. (2016) from river to shelf, anatomy of a high-frequency depositional sequence: the late pleisto cene to holocene tiber depositional sequence. sedimentology, 63 (7), 1886-1928. doi: 10.1111/sed.12277 moscatelli m., pagliaroli a., mancini m., stigliano f., cavuoto g., simionato m., peronace e., quadrio b., tommasi p., cavinato g.p. et al. (2012) integrated subsoil model for seismic microzonation in the central archaeological area of rome (italy). disaster advances, 5, 109-124. moscatelli m., pagliaroli a., cavinato g.p., castenetto s., naso g. (2014 a) seismic microzonation of palatine hill, roman forum and coliseum archaeological area. bulletin of earthquake engineering, 12, 1269-1275. doi: 10.1007/s10518-013-9539-z moscatelli m., piscitelli s., piro s., stigliano f., giocoli a., zamuner d., marconi f. (2014 b) integrated geological and geophysical investigations to characterize the anthropic layer of the palatine hill and roman forum (rome, italy). bulletin of earthquake engineering, 12, 1319-1338. moscatelli m., pagliaroli a., mancini m., stigliano f., marini m., simionato m., cavinato g.p., colombi a. (2015) seismic microzonation of level 1 of the historic center of rome. rendiconti online della società geologica italiana, 33, 63-70. doi: 10.3301/rol.2015.16 north c.p., davidson s.k. (2012) unconfined alluvial flow processes: recognition and interpretation of their deposits, and the significance for paleogeographic reconstruction. earth-science reviews, 111, 199-223. orton g.j. (1996) volcanic environments. in: reading h.g. (ed.) sedimentary environments: processes, facies and stratigraphy. third edition. blackwell science, 485-567. palombi d. (1997) tra palatino ed esquilino: velia, carinae, fagutal. storia urbana di tre quartieri di roma antica. rivista dell’istituto nazionale d’archeologia e storia dell’arte, supplemento 1, roma, pp. 200. palombi d. (2016) i fori prima dei fori. storia urbana dei quartieri di roma antica cancellati per la realizzazione dei fori imperiali. edizioni espera, monte compatri (italy), pp.378. patacca e., sartori r., scandone p. (1990) tyrrhenian basin and apenninic arc: kinematic relations since late tortonian times. memorie della società geologica italiana, 45, 425-451. retallack g.j. (2001) soils of the past. an introduction to paleopedology. second edition. blackwell science, pp, 404. sarti g., rossi v., amorosi a. (2012) influence of holocene stratigraphic architecture on ground surface settlements: a case study from the city of pisa (tuscany, italy). sedimentary geology, 281, 7587, doi: 10.1016/j.sedgeo.2012.08.008 shackleton n.j., berger a., peltier w.r. (1990) an alternative astronomical calibration of the lower pleistocene time scale based on odp site 677. transactions of the royal society of edinburgh, earth sciences, 81, 251-261. shanley k., mccabe p.j. (1994) perpectives on the sequence stratigraphy of continental strata. american association of petroleum bulletin, 78, 544568. tanabe s., nakanishi t., ishihara y., nakashima r. (2015) millennial‐scale stratigraphy of a tide‐ dominated incised valley during the last 14 kyr: spatial and quantitative reconstruction in the tokyo lowland, central japan. sedimentology, 62 (7), 1837-1872. stratigraphy of the palatine hill 193 194 mancini m. et al. doi: 10.1111/sed.12204 van dinter m., cohen k.m., hoek w.z., stouther e., middelkoop h. (2017) late holocene lowland fluvial archives and geoarchaeology: utrecht's case study of rhine river abandonment under roman and medieval settlement. quaternary science reviews. 166, 227-265. doi: 10.1016/j.quascirev.2016.12.003 watkins s.d., giordano g., cas r.a.f., de rita d. (2002) emplacement processes of the mafic villa senni eruption unit (vseu) ignimbrite succession, colli albani volcano, italy. journal of volcanology and geothermal research, 118, 173-203. wright v.p., marriott s.b. (1993) the sequence stratigraphy of fluvial depositional systems: the role of floodplain sediment storage. sedimentary geology, 86, 203-210. ms. received: marz 28, 2018 final text received: october 25, 2018 available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 31 (2), 2018, 235 244 underground exploitation in urban areas by geothermal heat pump systems: the example of turin politecnico test site (nw italy) glenda taddia dipartimento di ingegneria dell'ambiente, del territorio e delle infrastrutture, politecnico di torino, italy corresponding author: g. taddia <glenda.taddia@polito.it> abstract: the turin urban district (nw italy), is a flat area, at about 248 m asl, mainly developed on the outwash plain constituted by several outwash coalescing fans connected to the pleistocene expansion phases of the susa glacier. its geological context is well known with three main stratigraphical units described, i.e. unit 1: miocene molassic sequence; unit 2: pliocene sabbie di asti, argille azzurre formation and villafranchian deposits; unit 3: quaternary deposits (outwash sediments). once these geological features were taken into consideration we focused on the issues related to the impact of geothermal heat pump systems to groundwater in the turin urban context where a significant number of installations of medium and large sized groundwater heat pumps is present. local environmental features may influence the development of low-enthalpy geothermal systems and the choice of the most suitable type of system to install. in the case of open loop heat pumps, water re-injected in the aquifer after its use is characterized by a different temperature with respect to the undisturbed aquifer. this thermal disturbance propagates through the groundwater and may affect the temperature of water withdrawals operated by downstream installations. the analyses of politecnico turin's open loop systems have confirmed that the main factors controlling the thermal affected zone (taz thermal plume) are those related to the advective component of heat flow. the piezometric surface was obtained by means of a well and piezometer survey, during hydrogeological investigations. the turin politecnico test site attests the relevance of the geological and hydrogeological characterization of the subsoil in the design the gwhp systems in urban areas. keywords: gwhp systems, sensitivity analysis, hydrogeological parameters, turin, italy 1. introduction geothermal heat pumps represent an interesting technology expected to contribute significantly to the reduction of primary energy use for heating and cooling. additional benefits of this technology, which also meets the european union targets, are the possibilities of integration with discontinuous energy resources, in particular wind, combining heat and power. the replacement of conventional heating systems such as boilers, with general heat pump systems allows the de-localization of emissions of micropollutants from urban centers to the sites in which thermal power stations are operating. for example the district heating is a system for distributing heat generated in a centralized location for residential and commercial heating requirements such as space heating and water heating (verda & ciano 2005; poma et al. 2010). this also enhances the emissions monitoring and control. furthermore, the use of distributed production systems based on the use of renewable sources reduces also co2 emissions (baccino et al., 2010; lo russo et al., 2011). in this general context, the discharge of water, at different temperatures compared to baseline (warmer in summer and colder in winter), poses a number of problems in relation to the potential functionality of many existing situations of use of the groundwater (drinking water wells, agricultural plants, industrial plants, etc.). in addition, there may be cases of interference between systems, especially in the more densely urbanized areas. in this paper, some fundamental aspects related to the development of open-loop heat pumps have been explored in a typical urban contest (turin city, nw italy). in particular, appropriate hydrogeological investigations and simulation modelling were performed for the characterization of the main hydrogeological parameters of the subsoil at the considered site. the results of the work have allowed to define several fundamental aspects in order to optimize the design choices of groundwater heat pump (gwhp) systems and the importance of geological and hydrogeological surveys. after a general description of the low enthalpy geothermal heat pumps technologies, the analysis and comparison of the current hydrogeology problems in urban area are described, considering the impact of groundwater heat pump system in an urban contest. the conceptual model for the groundwater flow system, the schematization of the aquifer boundaries and the estimation of basic hydrogeological parameters are among the main issues which should be investigated in the development of open-loop heat pumps plants. in particular, some characteristics of urban elements require particular attention if compared to less anthropized areas. https://doi.org/10.26382/amq.2018.18 https://en.wikipedia.org/wiki/space_heating https://en.wikipedia.org/wiki/water_heating 236 taddia g. 2. materials and methods 2.1 low enthalpy geothermal systems the discharge of water at different temperatures compared to baseline (warmer in summer and colder in winter) poses a number of problems in relation to the potential functionality of many existing situations of groundwater use. the successful implementation of very low enthalpy geothermal plants for heating and cooling buildings in several sectors of city has highlighted one such technology. two basic geothermal heat pump systems exist: an earth-coupled (closed-loop) type (gshp) and a groundwater (open-loop) type (gwhp) (rafferty, 2000; lund, 2007). in the first type heat exchangers are located underground: horizontally-type, in various kind of configuration: connection in series (fig. 1a), trench connection (fig. 1b), connection in parallel (fig. 1c) and spiral slinky connection (fig. 1d); vertically (fig. 2), downhole heat exchanger (dhe); obliquely, a heat carrying medium is circulated within the exchanger, transferring the heat from or to the ground via a heat pump and the connection are obliquely respect the surface. the gshp (horizontally configuration) is usually the most cost-effective configuration when adequate yard space is available and trenches are easy to dig, especially while a building is under construction. dhes are widely used when there is a need to install sufficient heat exchange capacity under a confined surface area, such as when the soil is rocky close to the surface or where minimum disruption of the landscape is necessary. open-loop groundwater heat pumps (fig. 3) typically withdraw groundwater to provide heat (pdep, 1996). in winter, the gwhp extracts heat from the water to provide space heating. with reversible heat pumps, the heat-transfer process can be reversed in the summer and the groundwater absorbs heat from the living or working space and cools the air (doe, 1999; banks, 2012). gwhps are suited to regions with extended shallow aquifers, from which it is relatively easy and not very expensive to extract groundwater (drijver & willemsen, 2001). three different configurations of open-loop systems exist as summarized in fig.4. direct open-loop heat pumps (fig. 4a), where the water is passed directly through the heat exchangers of the heat pump, are largely used for residential and very small commercial applications (rafferty, 2001). this system is most suitably applied where low-salinity groundwater is available, because the direct use of highsalinity waters can cause scaling, i.e. the deposition of mineral scales in pipes, valves and/or heat exchangers (pdep, 1996). standing column well systems (scws) (fig. 4b) are used in locations where groundwater wells do not produce sufficient water for a conventional openloop system and where water quality is also good chemical characteristic. in scw systems, groundwater is recirculated from one end of the column well (static water level) to the heat pump, and back to the other end (bottom) of the deep bore. in other words, if consider the figure 4b where we recirculate a carrier fluid (groundwater) down the well bore (extraction and injection well) and up a rising main we obtain that a certain proportion of that flow to waste (following passage through the heat pump). this will have the effect of lowering heads within the borehole fig. 1 closed-loop horizontally system, with ground source heat pump (gshp). various type of configuration are represented: a) connection in series, b) trench connection, c) connection in parallel and d) spiral slinky connection (rafferty, 2000; lund, 2007). 237 exploitation in urban areas by geothermal heat pump systems: the example of turin (nw italy) and inducing the influx of a corresponding amount of new groundwater to the borehole. this groundwater will also transfer a new ‘load’ of heat to the system by advection (banks, 2012). usually, only one well is required for conventional buildings; larger projects may have several wells in parallel. scw systems can be thought of as a cross between closed-loop earth-coupled systems and open-loop groundwater source systems. the indirect open-loop systems (fig. 4c) generally involve a heat exchanger between the building loop and the groundwater, which eliminates exposure of any building components to groundwater (rafferty, 2001). the most important consideration in gwhp design is to fig. 4 several types of open-loop systems: a) direct open loop heat pumps; b) standing column systems (scw); c) indirect open loop systems (rafferty, 2001). fig. 2 closed-loop vertical system with downhole heat exchanger (dhe). fig. 3 open-loop system, with groundwater heath pump gwhp. obtain a plentiful amount of groundwater with a very stable temperature. generally, a highly productive, shallow (within 30 m of surface) aquifer would favor successful and efficient functioning of the gwhp. 2.2 site application: politecnico of turin the site is located in center of the city of turin (piemonte region) where in the last fifteen years territorial changes have produced effects on the intensive urban transformation processes. the latter, mainly represented by the progressive re-organization of the metropolitan transport network (including the construction of a railway link and the first line of the subway system) and by lots of urban regeneration projects, transformed abandoned industrial (polluted) sites in restored new houses and services areas (commercial, cultural and, partly, productive) (lo russo & taddia, 2009; 2010). the dynamic consequences of these intense and rapid transformations affected significantly the environmental conditions of the urban groundwater system. the first experimental results derived by a groundwater monitoring around an injection well of an openloop gwhp has been discussed. this system has been installed in the politecnico of turin (fig. 5) for cooling some of the university buildings, such as offices and laboratories. two 47 m-deep wells, one used for groundwater extraction (p2) and the other for injection (p4), and a piezometer (s2) in placed 35 m downgradient respect to the p4, having the same technical characteristics (fig. 6) are present at the site. the wells have a steel casing diameter of 355 mm. the bridgeslot screens are located below 19 m down to 47 m. the annulus from the surface to 6 m depth is cemented with bentonite grout. the filter pack is represented by calibrated gravel below 6 m down to 47 m depth (fig. 6). the plant was performed during the cooling period (summer) to assess the warm taz development around the injection well. through multiparameter probes (ott ecolog800) (fig. 7) installed in the pumping and injection wells and also inside the piezometer, it is possible to check the water level, temperature and conductivity in groundwater and then the movement of the warm plume over time during the operating period of the heat pump. the multi-temporal thermal logs in s2 highlighted the plume thermal stratification in the aquifer and confirm the hypothesis about the prevailing advective transport component for heat flow. the potential impact of the heat pump groundwater has been assessed according to the features of the site, users, wells and the machine installed through an approach based on numerical simulations. the main software that it was utilized is feflow®. feflow® (finite element subsurface flow system) is a program for simulating groundwater flow, mass transfer and heat transfer in porous and fractured means (diersch 2010). the numerical models were validated by comparison with experimental data from significant open loop heat pumps systems installed in politecnico of turin. the geological and hydrogeological site characteristics in the modeling can be great help to determine the geometry and operating mode. 2.3 geological and hydrogeological context the turin urban area is situated in the northwestern po plain, surrounded by alps. on the outwash plain of several outwash coalescent outwash fans associated to the pleistocene expansion phases of the susa glacier. the turin plain is bounded by the rivoliavigliana morainic amphitheatre on the west side and 238 fig. 5 open loop system (gwhp) installed in the “politecnico di torino” for cooling some of the university buildings. schematic map with location wells and piezometer (a), the heat pump plant (b), p4 is the injection well (c), p2 is the extraction well (d) and s2 is the piezometer located towards respect the wells (e). taddia g. turin hill on the east. the geological setting of this area is quite well known by numerous wells (regione piemonte, 2007) and detailed geological studies (boano et al., 2004; forno & lucchesi, 2005; forno et al., 2018). the geological setting of the plain urban area is characterized by a strong geographical anisotropy. comprehensive geological and hydrogeological studies (civita et al., 2004; regione piemonte, 2005) including the “historical” information, trying to produce integrated geo-referred database and maps, permitted the definition of the subsurface geological setting and the interpretation of the groundwater system. a broad analysis of this database has led to a new explanation of the subsurface stratigraphic relationships among the different (hydro) geological bodies. three main (hydro) stratigraphic units have been distinguished based on depositional age, structural setting, lithological composition and hydrogeological properties. their characteristics and relative relationships are described below (fig. 8). the oldest unit (unit 1-miocene) is constituted by conglomerates, sandstones and marls typical of the terrigenous sequence belonging to the piemonte tertiary basin. the upper part is locally characterized by the presence of evaporites belonging to the messinian gessoso-solfifera formation. unit 1 is stratigraphically overlapped by the subsequent unit 2 (pliocene) or truncated by the main erosional quaternary surface and therefore directly in contact with the upper outwash deposits (unit 3 quaternary). despite the limited deep geological evidence the stratigraphic correlations within unit 1 confirms the presence of the westward buried extension of the asymmetric anticline verging to the nw, with a sw-ne axis characterizing the turin hill sector. unit 2 is characterized by a different sedimentation environment with a lateral heteropic transitional relationship. the unit 2 consists of shallow marine deposits, traditionally defined as sabbie di asti and/or argille azzurre formation, mainly composed of fossiliferous sandy and clayey layers with subordinate barren fine gravely and coarse-grained sandy marine layers or by quartzmicaceous sands. in the other part of the torino area (not in the site area) villafranchian deposits are present. they consist of fine-grained sediments (sand, silt and clay with inter-bedded gravel) which were organized into several sedimentary bodies (forno et al., 2015). typical litho-facies are blue-grayish clayey sands and silts and yellowish to grayish sands and silts, usually with a rhythmic or pseudo-varved structure. at a local level it is possible to recognize fan-delta deposits formed by gravel layers in a sandy matrix and, less commonly, boulders in a sandy-silty-clayey matrix. the top of unit 2 was erod 239 fig. 6 technical scheme of the politecnico wells, utilized for open loop system (gwhp). fig. 7 the ott multiparametric probe, a compact system for monitoring water level, temperature and conductivity. exploitation in urban areas by geothermal heat pump systems: the example of turin (nw italy) ed away and covered by the outwash alluvial deposits characterizing unit 3 (fig. 9). outcrops of unit 2 are to be found on the southern side of turin hill. on the opposite, unit 2 is fully buried under unit 3 in the turin city area and it can be recognized only by analyzing logs data. in detailed the hydrogeological regional setting is strongly influenced by the presence of the rivoliavigliana morainic amphitheatre (rama) on the west side and the turin hill sector on the east (ivy-ochs et al., 2018). the buried lithotypes of unit 1 below units 3 and 2 (figs. 8 and 9) represent the bottom impermeable layer for the unconfined eastward groundwater regional down-flowing mainly developed in the quaternary deposits (unit 3). as a matter of fact, unit 3 represents an important unconfined high productive aquifer hydraulically connected to the main surface water drainage network (sangone, dora riparia, stura di lanzo and po rivers). the permeability can reach high values (k1 = 240 fig. 8 geological sketch map, with the main geological units that represent the turin area. (geological map of italy, scale 1:100000, layout 56, not in scale) where a: unit 3, fluvial deposits; b: unit 3, fluvioglacial deposits; c: unit 1 and unit 2, tertiary succession; rama: rivoli-avigliana morainic amphitheatre. fig. 9 cross-section of the open loop system (gwhp) installed in the “politecnico di torino” for cooling some of the university buildings. taddia g. lic gradient dh/dl, the volumetric heat capacity of fluid (water) ρfcf and solid (aquifer matrix) ρscs, the heat conductivity of the fluid λf and solid λs and the longitudinal αl and transversal αt thermal dispersivity (tab. 1). the simulation results reported in fig. 10 refer to the parameters under sensitivity analysis. the horizontal kxx; kyy and vertical kzz hydraulic conductivity, the hydraulic gradient dh/dl as well as the porosity n, the longitudinal αl and transverse αt thermo-dispersivity condition the size of the taz in an appreciable way. finally the effects on the variations of the values of storativity ε and the heat conductivity of fluid λf and solid λs appear to be almost negligible. the results highlight that the parameters most affecting the taz development are connected to the advective component of the heat flow in the aquifer. another important element which resulted in validate numerical models was the comparison between experimental data and real data from plants with significant heat pumps open-loop of the politecnico of turin. the time variability of the building’s energy demand can affect both the groundwater withdrawal and injection flow rates q = qout= qin and the temperature difference between the injection and extraction wells δt = (tin− tout). pumps may be equipped with inverters so the water mass flow rate can be reduced when heating/ cooling requirements decrease, maintaining high system efficiency during periods of partial load. generally, inverter technology induces variability in both the flow (q) and temperature differential (δt). correct assessment of the taz around the injection well and good correspondence between the simulation results and measured data require an effective numerical model that takes into account the time transient variability of q and δt. however, there is generally a lack of accurate input data concerning the dynamic variability of q and δt parameters over time, particularly during preliminary gwhp plant design phases. in practical engineering, the effects of time variability on the taz calculations are often disregarded, and the subsurface numerical simulation of the taz is developed using q 1×10−3 ¸ 1×10−4 m sec-1) depending on the local sediment granulometry. this aquifer is quite vulnerable to pollution because of its shallowness and the absence of significant natural barriers (clay levels) in the sedimentary body (unit 3 in fig. 9). the potentiometric surface shows generally a w-to-e gradient ranging from 0.61.2% (mean 0.9%) (civita et al., 2004; regione piemonte, 2005). the shallower underground of site area is characterized by two main stratigraphic units (units 3 and 2) with hydraulic properties and the gradient is about 0.3% (fig. 9). 3. results 3.1. the importance of hydrogeological parameters in the numerical modeling proper installation and effective maintenance of gwhp plants requires an appropriate characterization of subsurface heat transport processes such as conduction and convection. during the process, the aquifer temperature is disturbed and cold or warm plumes develop. these disturbances are reduced by lateral conductive heat transport and convection due to moving water (hechtmendez et al., 2010). the use of the well doublets for groundwater-sourced heating or cooling typically results in a thermal plume of cool or warm reinjected groundwater. such a plume may be regarded either as a potential anthropogenic geothermal resource or as pollution, depending on downstream aquifer usage. a thermal plume may pose an external risk to downstream users and environmental receptors or an internal risk to the sustainability of the well doublet, due to the phenomenon of thermal feedback. during the preliminary design of gwhp systems the aquifers are usually investigated to determine the parameters affecting heat flow. these investigations involve hydrogeological measurements both in situ and in the laboratory and are often costly and difficult to perform. physical properties of the aquifer such as the porosity and density of the aquifer framework may be obtained through field and laboratory geotechnical testing. hydrogeological parameters such as hydraulic conductivity and the storativity are usually obtained from pumping test results. hydrothermal parameters such as the specific heat capacities and thermal conductivities of the groundwater and the aquifer framework may be calculated from laboratory tests and heated water injection data (zhou & zhou, 2009). the first issue that was conducted was a sensitivity analysis (lo russo et al., 2012) to test in the site the influence of several parameters on the development of taz. the taz is defined as the area included by the isotherm 16◦ c (i.e. 1°c difference with the undisturbed underground temperature). the subsoil parameters tested using the sensitivity analysis were related to the unconfined aquifer under exploitation and include the hydraulic conductivity (horizontal kxx; kyy and vertical kzz), the porosity n, the storativity ε, the natural hydrau 241 tab. 1 thermal and hydrodynamic parameters used as input data in feflow modelling. exploitation in urban areas by geothermal heat pump systems: the example of turin (nw italy) and δt values that are held constant over an extended time interval (usually a month or an entire season). these time-averaged values of q and δt are usually derived from simulations of building energy needs and are calculated based on the principle of energy equivalence. from a practical stand point, the use of timeaveraged flow rates and temperatures reduces the computational load, but the simplification may also negatively impact the quality of the temperature predictions. during the study, the flow and energy transport simulations were executed using hourly data. using this hourly data set and taking into account the energy conservation principle, we calculated daily, monthly, and seasonal energy equivalent values for q and δt and performed additional subsurface simulations using the averaged data. the results were analyzed using linear regression analysis and statistical testing in order to verify their ability to correctly predict taz development. the simulations were performed during the cooling period to assess the development of a warm taz around the injection well (p4). appropriate feflow® time-varying functions (tvfs) for q and δt were defined based on monitoring data extracted from the heat pump control system. all parameters were measured on an hourly basis. to assess the taz, four computational modeling scenarios were defined and tested. the first (t1) took into account the hourly variable data for q and δt. the tvfs for q and δt were derived directly from the monitoring data. the second scenario (t2) used daily averages calculated from the hourly data. the third (t3) used monthly equivalents, and the last (t4) scenario employed a seasonal equivalent value for q and δt. the equivalent volumetric flow rates and temperature differences used in scenarios t2–t4 were obtained by averaging the quantities in a balanced manner and the time interval was selected period (day in t2, month in t3 and season in t4), δt is the simulation time interval (1h). the reliability of the simulations was obtained by comparing simulated temperatures with the piezometer measurements (s2) plotted in fig. 11. t1, t2, and t3 exhibited the same trend as the measured data, while the fourth (t4) was quite different from the observed groundwater temperature profile (lo russo et al., 2014). in conclusion, in order to obtain a good match between simulated and current groundwater temperatures during modeling of the taz produced by a gwhp plant, it is necessary to model the injection using realistically variable flow rates and injection temperature data. the use of average hourly, daily or monthly injection flow rate and temperature data produced good quality simulation results. in contrast, the use of seasonal average values did not produce good estimates of the taz. this 242 fig. 10 location of 16.0°c isotherms after 60 days of injecting warmer water for various values of horizontal and vertical conductivity, hydraulic gradient and porosity. taddia g. element is particularly important in the design of plants in which it is necessary to assess the extent and dynamics of the underground thermal perturbation to avoid interference with nearby plants or wells used for other purposes. 4. conclusions in conclusion, the territory of the city of turin is well suited to the analysis of issues related to the impact of heat pumps to groundwater. in this area, many installations of medium and large size groundwater heat pump have been performed and this number is still increasing. in the case of open loop heat pumps, water reinjected in the aquifer after its use is characterized by a different temperature than the undisturbed aquifer. this thermal disturbance propagates through the groundwater and may affect the temperature of water withdrawals operated by downstream installations. heat pump efficiency depends on the inlet temperature of water, thus there may be unforeseen changes in performances that often leads to primary energy requirements larger than the initial expectations. the unconfined aquifer that extends over the entire urban plain, including the location of the investigated site, is hydraulically connected to the main surface water drainage network in the area (i.e. the dora riparia and sangone rivers). for this reason, the developed research has shown the existing potential of the low enthalpy geothermal heat pump system, both regionally and locally because in turin area there is a lots of quantity water resource. in this context it is possible to support that the prediction modeling is necessary both to assess the effects on the environment around the plant and to optimize the design choices. the modeling can be very helpful to determine the geometry and operating mode. the analyses of politecnico turin's open loop systems have confirmed that the main factors affecting the development of the thermal affected zone (taz thermal plume) are those related to the advective component of heat flow. in fact, the sensitivity analysis of the main parameters that most influence the development of the thermal plume has been shown that it should be pay attention to the geological and hydrogeological subsurface characterization. the reconstruction of the piezometric surface obtained by means of a well and piezometer survey, also appears to be essential in a correct program of geological and hydrogeological investigations. the determination of the taz around the injection points is a fundamental aspect in the project phase of groundwater open-loop geothermal systems development. in fact, it is important to know in the earlier phase of the project if the exploited aquifer is suitable for the system to be implemented and if the taz is interfering with other previously existing wells or subsurface infrastructures and land uses. then the input data are fundamental to affecting the quality of the simulation. for this reason, the geological and hydrogeological surveys are very important to reconstruct the geothermal heat pump design choices. however, even taking into account all the limitations of the open-loop heat pumps technology, we believe that these systems represent one of the most promising potential clean energy sources especially in the urban areas under transformation in order to reach the important goal of greenhouse-gas emission reduction of the future smart livable cities. references baccino g., lo russo s., taddia g., verda v. (2010) energy and environmental analysis of an open 243 fig. 11 temperatures in piezometer s2. the dotted line corresponds to the measured data exploitation in urban areas by geothermal heat pump systems: the example of turin (nw italy) loop ground water heat pump in a urban area. thermal science, 14, 693-706. banks d. (2012) an introduction to thermogeology ground source heating and cooling. wiley, chichester, uk, pp. 6. boano p., forno m.g., lucchesi s. (2004) pleistocene deformation of the collina di torino inferred from the modeling of their fluvial succession. il quaternario, it. journ. quat. sc., 17, 145-150. civita m., lo russo s., vigna b. (2004) hydrogeological sketch map of piemonte (nw italy) 1:250.000. proceeding of the 32nd international geological congress, aug. 21-28, florence, italy. diersch h.j.g. (2010). feflow® 6 user’s manual. wasy gmbh, berlin. 9-197. doe (1999) renewable energy annual 1998: issues and trends. u.s. department of energy, office of coal, nuclear, electric and alternate fuels, report doe/eia0603(99), washington, dc, usa, pp. 117. http://tonto.eia.doe.gov/ftproot/ renewables/060399.pdf. drijver b., willemsen a. (2001) groundwater as a heat source for geothermal heat pumps. in: international summer school on direct application of geothermal energy, international geothermal association, bad urach, germany, september 17-20, 156166 forno m.g., lucchesi s. (2005) la successione fluviale terrazzata pleistocenica dei versanti occidentale e nordoccidentale della collina di torino. il quaternario, it. journ. quat. sc., 18 123-134. forno m. g., gattiglio m., comina c., barbero d., bertini a., doglione a., irace a., gianotti f., martinetto e., mottura a., sala b. (2015) stratigraphic and tectonic notes on the villafranca d’asti type-area and castelnuovo don bosco sector (asti reliefs, piedmont). alpine and mediterranean quaternary, 28(1), 5-27. forno m.g., de luca d.a., bonasera m., bucci a., gianotti f., lasagna m., lucchesi s., pelizza s., piana f., taddia g. (2018) synthesis on the turin subsoil stratigraphy and hydrogeology (nw italy). alpine mediterranean quaternary, 31(2), 124. hecht-mendez j., molina-giraldo n., blum p., bayer p. (2010) evaluating mt3dms for heat transport simulation of closed geothermal systems. ground water 48(5), 741-756. ivy-ochs s., lucchesi s., baggio p., fioraso g., gianotti f., monegato g., graf a., akcar n., christl m., carraro f., forno m. g., schluchter c. (2018) a first 10be based chronology for glacial extents in the lower susa 1 valley and in the rivoli-avigliana end-moraine system (western alps, nw italy). journal of quaternary science, 2018, 1-13. doi: 10.1002/jqs.3034 lo russo s., taddia g. (2009) groundwater in the urban environment: management needs and planning strategies. am. j. environ. sci., 5(4), 493499. lo russo s., taddia g. (2010) advective heat transport in an unconfined aquifer induced by the field injection of an open-loop groundwater heat pump. american journal of environmental sciences 6(3), 253-259. lo russo s., taddia g., baccino g., verda v. (2011) different design scenarios related to an open loop groundwater heat pump in a large building: impact on subsurface and primary energy 387 consumption. energy and buildings 43, 347-357. lo russo s., taddia g., verda v. (2012) development of the thermally affected zone (taz) around a ground water heat pump (gwhp) system: a sensitivity analysis. geothermics 43, 66-74. lo russo s., gnavi l., roccia e., taddia g., verda v. (2014) groundwater heat pump (gwhp) system modeling and thermal affected zone (taz) prediction reliability: influence of temporal variations in flow discharge and injection temperature, geothermics, 51, 103-112. lund j. (2007) characteristics, development, and utilization of geothermal resources. geo-heat center quarterly bulletin, 28(2), 1-9. pdep (1996) ground source heat pump. pennsylvania department of environmental protection fact sheet, harrisburg, pa, usa, pp. 2. poma c., verda v., consonni s. (2010) design and performance evaluation of a waste-to-energy plant integrated with a combined cycle. energy 35, pp. 93. rafferty k. (2000) scaling in geothermal heat pump systems. geoheat centre quarterly bulletin 21, 11 -15. rafferty k. (2001) design aspects of commercial openloop heat pump systems. geoheat centre quarterly bulletin, 22, 16-24. regione piemonte (2005) idrogeologia della pianura piemontese, mariogros industrie grafiche s.p.a., 2 -45 regione piemonte (2007) piano di protezione delle acque. d.c.r. n. 117-10731, turin, italy. h t t p : / / w w w . r e g i o n e . p i e m o n t e . i t / a c q u a / pianoditutela/pta/aree/ai14/pdf/index.htm verda v., ciano c. (2005) procedures for the search of the optimal configuration of district heating networks. in: international journal of applied thermodynamics, 8, 143-154. zhou y.z., zhou z.f. (2009) simulation of thermal transport in aquifer: a gwhp system in chengdu, china. journal of hydrodynamics, 21 (5), 647-657. 244 ms. received: marz 29, 2018 final text received: august 3, 2018 taddia g. available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 69 71 pollen evidence of vegetation changes and land use on the tropea promontory (calabria, italy) during prehistory halinka di lorenzo, elda russo ermolli dipartimento di scienze della terra, dell'ambiente e delle risorse, università di napoli federico ii, napoli, italy corresponding author: h. di lorenzo <halinka.dilorenzo@unina.it> abstract: pollen analysis was undertaken on a sediment core drilled at the top of the tropea promontory (calabria), an area rich in archaeological evidence from the eneolithic up to the iron age. human impact is clearly detected in the basal portion of the core through deforestation, fires, crops and pasturage activities. the anthropic pressure seems to generally reduce around the core site in the second half of the core, when a significant forest recover is recorded. these local vegetation changes and land use could be ascribed to both a gradual closure of the marsh and a possible abandonment of this area for pastoral and agricultural practices. keywords: palynology, microcharcoals, deforestation, human impact, late holocene 1. introduction archeological surveys of the last years have witnessed a diffuse human presence in the tropea promontory during prehistoric times (pacciarelli, 2004, 2011; lo torto, et al., 2011; jung, et al., 2015). in order to better define the impact that humans exerted on this territory during prehistory, palynological investigations were realized with the main aim of distinguishing the natural and anthropogenic forcing in the evolution of the past landscapes. the results here presented increase the knowledge, already acquired in this area (russo ermolli et al., 2018), on the complex human environment interactions in a key region for the italian prehistory. 2. material and methods a sediment core was drilled at 555 m a.s.l. on top of the tropea promontory, a site rich in archeological evidence dated from the eneolithic up to the iron age. the site was selected on the basis of a previous study (lo torto et al., 2011) highlighting the occurrence of buried layers with eneolithic pottery in the passo murato locality. the coring, realized in 2015 with a small piston corer, intercepted a peat deposit (from 1.10 to 2.40 m depth), covering the pre-quaternary substratum, whose base likely corresponds to the levels analyzed by lo torto et al. (2011). pollen analysis was undertaken on 21 peat samples collected from the core each 5 cm, from 110 to 235 m depth. chemical (hcl 20%, hf 40%, hot hcl 10%, acetolysis) and physical (10 μm ≤ sieving ≤ 200 μm, zncl2 floating) treatments were used to concentrate pollen grains in the residue. slides were mounted in glycerin to permit pollen motion and facilitate taxonomical determination. determinations and counts were carried out under a light microscope at 500x and 1000x magnification, with the support of pollen atlases (reille, 1992-1995; beug, 2015) and reference pollen material. 3. results almost all analyzed samples resulted rich in well preserved pollen grains and only 4 samples resulted poor; 74 taxa were recognized. a synthetic diagram was realized (fig. 1) by selecting taxa, or groups of taxa, among the most representative of man impact. from the left-hand side of the diagram, some selected trees are shown: quercus ilex (mediterranean forest), quercus (deciduous forest) and alnus (floodplain forest), followed by microcharcoals. the arboral pollen (ap) curve indicates the rate of the forest cover. it is assumed that ap percentages over 70% are indicative of a forested landscape while percentages below 40% indicate open environments (favre, et al., 2008). intermediate percentages (from 40 to 70%) indicate a patchy landscape with open spaces and scattered forested areas. the herbaceous taxa are dominated by the poaceae family. the main anthropogenic indicators are displayed with different percentage scales, depending on their amounts. cyperaceae (marsh plants) are listed at the extreme right of the diagram. 4. discussion and conclusion in the basal part of the diagram, high amounts of microcharcoals, recorded in concomitance with the lowering of arboreal pollen percentages, attest to the use of anthropogenic fires to open the landscape for agricultural practices (cereals) and animal husbandry, which is well testified by the high amounts of fungal spores, indicative of pasturage (cugny et al., 2010; ejarque et al., 2011). starting from 165 cm depth, a decrease in the fire practice is coupled with the recovery of the forest cover and an increase in the marsh plants. these vegetation https://doi.org/10.26382/aiqua.2018.aiquaconference changes could indicate both a contraction of the marsh and a partial abandonment of the area. some cereal crops were still present and a peak of trifolium opens up interesting hypothesis on the occurrence of forage crops (miras et al., 2018). another important change is recorded from 130 cm depth, when alnus markedly increases in concurrence with the decrease in cyperaceae. these results could indicate a further contraction and final closure of the marsh, which led to the rapid development of an alder forest on the wet soils. evidence of abandonment is clearly recorded in the last levels even if the topmost sample seems to suggest a possible recolonization, with a slight forest decline and cereal increase. the reconstructed history of vegetation and land use changes on the tropea promontory certainly needs further investigation especially concerning their connection to the presence of prehistoric communities. the detailed dating of the core, which is in progress, will allow such connections to be established. with this perspective, the passo murato core represents an important sedimentary archive that enriches the knowledge of an important territory widely exploited by prehistoric human communities. references anzidei a.p., bulgarelli g.m., catalano p., cerilli e., gallotti r., lemorini c., milli s., palombo m.r., pantano w., santucci e. (2012) ongoing research at the late middle pleistocene site of la polledrara di cecanibbio (central italy), with emphasis on human-elephant relationships. quaternary international, 255, 171-187. beug h.j. (2015) leitfaden der pollenbestimmung für mitteleuropa und angrenzende gebiete. verlag dr. friedrich pfeil, munchen. cugny c., mazier f., galop d. (2010) modern and fossil non-pollen palynomorphs from the basque mountains (western pyrenees, france): the use of coprophilous fungi to reconstruct pastoral activity. vegetation history and archaeobotany, 19, 391408. ejarque a., miras y., riera s. (2011) pollen and nonpollen palynomorph indicators of vegetation and highland grazing activities obtained from modern surface and dung datasets in the eastern pyrenees. review of palaeobotany and palynology, 167, 123-139. favre e., escarguel g., suc j.p., vidal g., thévenod l. (2008) a contribution to deciphering the meaning of ap/nap with respect to vegetation cover. review of palaeobotany and palynology, 148, 13-35. jung r., pacciarelli m., zach b., klee m., thanheiser u. (2015) punta di zambrone (calabria) a bronze age harbour site. first preliminary report on the recent bronze age (2011-2012 camapaigns). archeologia austriaca, band 99/2015, 53-110. lo torto a., rombolà c., rombolà f., starpoli f. (2011) il giacimento di passo murato: scoperta, rilevamento, recupero e segnalazione. origini, 33 (n.s.v.), 293-294. miras y., ejarque a., barbier pain d., corbineau r., ledger m., riera mora s., garreau a., voldoire o., allain e., mangado llach j., sànchez de la torre m., màrtinez grau h., bergadà m.m., smith s. j. (2018) advancing the analysis of past human/plant relationships: methodological improvements of artefact pollen washes. archaeometry. doi: 10.1111/arcm.12375 pacciarelli m. (2004) la prima età del ferro in calabria. atti della xxxvii riunione scientifica dell’istituto italiano di preistoria e protostoria, vol. i (29 settembre-4 ottobre 2002), 447-475. 70 di lorenzo h., russo ermolli e. fig. 1 synthetic pollen diagram of passo murato core 71 pacciarelli m. (2011) l’eneolitico della calabria tirrenica: nuovi dati sull’articolazione cronoculturale. origini 33, n.s.v, 249-302. russo ermolli e., ruello m.r., cicala l., di lorenzo h., molisso f., pacciarelli m., (2018) an 8300-yr record of environmental and cultural&#13; changes in the sant’eufemia plain (calabria, italy). quaternary international. doi:10.1016/j.quaint.2018.01.033 reille m. (1992-1995) pollen et spores d’europe et d’afrique du nord. laboratoire de botanique historique et palynologie, ura cnrs 1152, marseille. pollen evidence of human impact in calabria (italy) ms. received: may 10, 2018 final text received: may 19, 2018 72 imp.coratza&giusti methodological proposal for the assessment of the scientific quality of geomorphosites paola coratza & cecilia giusti dipartimento di scienze della terra, università di modena, largo s. eufemia, 19, 41100 modena (italy) email: coratza.paola@unimore.it abstract: p. coratza & c. giusti, methodological proposal for the assessment of the scientific quality of geomorphosites. (it issn 0394-3356, 2005). the method proposed has been elaborated for assessing the scientific quality of geomorphosites. this method is quantitative, but a series of qualitative guide lines has been elaborated, in order to give a support for the attribution of values. scientific quality is calculated considering a series of parameters: expert’s knowledge (educational value and research value); areal extent; rarity; degree of conservation; exposure and an added value (related to the importance that the asset has for non-geomorphological aspects that nevertheless can increase its scientific value). afterwards, each parameter had to be weighted. this methodology could become a useful tool for optimizing decisional processes within the framework of territorial planning, environmental impact assessment and protection of the natural heritage. riassunto: p. coratza & c. giusti, proposta metodologica per la valutazione quantitativa della qualità scientifica di geomorfositi. (it issn 0394-3356, 2005). viene illustrata una metodologia per la valutazione quantitativa della qualità scientifica dei geomorfositi. questa proposta metodologica vuole essere un esempio di come si possa arrivare a valutazioni di tipo quantitativo, al fine di poter rendere la procedura di valutazione più obiettiva possibile, attraverso ragionamenti logici e espressioni qualitative. in particolare la qualità scientifica (q) del geomorfosito viene calcolata considerando una serie di parametri, alcuni strettamente legati alla connotazione scientifica del bene, altri indirettamente. questi parametri sono: la conoscenza dell’esperto, l’estensione areale, la rarità, il grado di conservazione, l’esposizione e il valore aggiunto. successivamente si procede all’attribuzione di un peso ad ogni parametro e alla quantizzazione della qualità scientifica del bene mediante una formula. la metodologia proposta è uno strumento utile per ottimizzare il processo decisionale nel campo della valutazione d’impatto ambientale (via), della pianificazione territoriale e della salvaguardia del patrimonio geologico. keywords: geomorphosites, assessment, gis. parole chiave: bene geomorfologico, valutazione, gis. il quaternario italian journal of quaternary sciences 18(1), 2005 volume speciale, 307-313 1. introduction according to the definition given by panizza (2001), a geomorphosite is a landform with particular and significant attributes which qualify it as a component of the cultural heritage (in a wide sense) of a given territory. attributes which can confer value to a geomorphosite are the scientific, cultural (in a strict sense), socioeconomic and scenic attributes. therefore, with this meaning geomorphosites make up the landscape, habitat, elements of geodiversity, knowledge of the dynamics of the earth’s past, memory of biological evolution and man’s life from its very beginning, and essential resources for economic and scientific development. as such, geomorphosites deserve to be treated with a correct and appropriate management and conservation policy. in the past few years the ever-growing interest in cultural and environmental assets has underlined the demand for operators possessing adequate tools for the correct assessment, conservation and management of all these assets. hence the need to select those aspects of the landscape that more than any others deserve to be identified, known and safeguarded. indeed, only by recognizing the intrinsic value and hierarchic rank of each single element with respect to all the objects found within the system considered, will it be possible to guarantee the correct policy of environmental management (scarelli & poli, 1999). for this purpose, a quantitative assessment of geomorphological assets must be carried out in order to compare these assets or other environmental and non-environmental assets and select them, especially within the framework of territorial planning or environmental impact assessment (eia) procedures. all these approaches are necessary in order to develop possible strategies and define priorities and scales of values. in literature numerous methods are described for the quantitative assessment of landforms. the earliest go back to the 1970s and were generally developed by scholars from english-speaking countries, in particular from the united states. worthy of note are the assessment procedures by linton (1968), leopold (1969) and fines (1968). some of these propose morphometric measurement methods of diverse landscape components which are considered representative of the scenic quality of a landscape. others are more subjective and concern the perception of a whole landscape in quantitative terms (panizza & piacente, 2003). nevertheless, the limits of these assessment procedures are considerable, because they are either too subjective or based on an unnatural subdivision of geomorphological assets. starting from these preliminary remarks, an experimental methodology for a quantitative assessment of 308 p. coratza & c. giusti the scientific quality of geomorphological assets was defined and applied to a study area of the modena province plain (emilia-romagna region), which was chosen as an example area. the method here illustrated was set up by utilising gis techniques, which are the most suitable instrument for the implementation of a dynamic, updateable and ductile system for the selection, census, mapping and quantitative analysis of geomorphological assets. in addition, this system can be used in specific applications such as environmental impact assessment, territorial planning and conservation of natural heritage (coratza & giusti, 2003). in particular, gis techniques allowed data and attributes relative to the assets described in the study area to be linked to the ctr topographic map at a 1:25,000 scale in raster format. furthermore, by means of this software a new system was created, capable of comprehending the collection, modelling and analysis of data produced in the previous phases. it can therefore be a useful instrument for optimising decisional procedures in the field of territorial planning and safeguard of geological heritage. 2. methodology the proposal here presented is meant to offer an example of how quantitative assessments can be attained by means of logical reasoning and qualitative expressions. in particular, the scientific quality of an asset is evaluated by means of several parameters, some of which are directly linked to the scientific identity of the asset whereas others are only indirectly related to it. the elaboration of this methodology is based on several previous investigations (panizza et al., 1995; barba et al., 1997, rivas et al., 1997; bertacchini et al., 1999; giusti & gonzalez, 2000) and can be considered a useful tool in territorial planning and environmental impact assessment. this methodology, directed to geomorphological assets and applied by using the “ilwis 2.2” and “arcview 3” geographical information systems (gis), can be subdivided into four phases: geograph ic-geomorpho log ica l study of the area considered, selection of assets, assessment of scientific quality, and calculation of impacts. 2.1. geographic-geomorphological setting of the study area the first investigation phase consisted of bibliographic research on the most significant scientific studies carried out on this topic. the research allowed reconstruction of the evolution and transformations occurring in historical t imes in the modena plain. furthermore, the interpretation of multiscalar and multitemporal aerial photographs and field surveys allowed an updated geomorphological map and a digital terrain model (dtm) of the modena plain to be realised. these documents are indispensable for selecting and mapping geomorphological sites. the modena plain is located in the south-central portion of the po plain and is bounded to the north by the province of mantova, to the east by the provinces of ferrara and bologna, to the south by the apennine foothills and to the west by the province of reggio emilia. the study area, which covers a total extension of about 1348 km2 (fig. 1), is represented in the following emilia-romagna ctr sheets at a 1:25,000 scale: 183 ne, 183 se, 183 so; 184 ne, 184 se, 184 so, 184 no; 185 so; 201 ne, 201 se, 201 so, 201 no; 202 ne, 202 so, 202 no; 219 ne, 219 se, 219 no, 219 so; 220 no. the territory under investigation stretches from north to south at elevations between 175 m to 7 m a.s.l. and, from the altitude viewpoint, can be subdivided into high, middle and low plain (various authors, 1997). the high plain is comprised between the apennine foothills and the via emilia, with elevations of 175 m to 50 m and corresponds to the alluvial fans of the main apennine watercourses. the middle plain is comprised between the via emilia and the 20 m contour line. the low plain is comprised between the 20 m and 7 m contour lines. the morphological evolution of the modena plain has mainly been conditioned by the evolution of the two main rivers that cross it: the river panaro, which flows along the eastern extremity of the province’s territory and the river secchia, which flows along the western extremity. indeed, numerous landforms occurring all over the territory result from present hydrography and ancient hydrography: fluvial ridges, ancient riverbeds, inundation fans, terraces, meanders, water springs etc. (castaldini, 1989). however, in more recent decades another element has increasingly conditioned the landscape: man with his various activit ies such as fig. 1 map of the study area. inquadramento dell’area di studio. quarrying, hydraulic works (e.g., meander cuts, artificial canals, flood mitigation structures) and urban development. 2.2. selection of geomorphological assets the selection of geomorphological assets was made by starting from the geomorphological vectorial map of the modena plain and from the dtm. both these documents were elaborated by means of gis ilwis 2.2 and arcview 3 programmes. this dtm, equipped with a shadow filter (fig. 2), can reconstruct the natural relief trend since contour lines (difference in altitude: 1 m) were traced without considering points corresponding to anthropogenetic structures (giusti, 2001). in addition, dtm is an indispensable tool for accurate reconstruction of plain area morphology and for a detailed representation of negative structures, such as hollow areas, and positive ones, such as rises. subsequently, a georeferenced map (coordinate system: utm) was realised with polygons representing the geomorphological assets of the modena plain (fig. 3). finally, a table of attributes containing both the data inherent to the assets’ own characteristics and their quantitative assessment, was associated with this map (fig. 4). thirteen assets were eventually selected: examples of i) fluvial meanders of the rivers secchia and panaro, which are now rare forms of the landscape owing to artificial straightening; ii) fluvial rises (gavello and ramo della lunga), which in most cases were flattened by human activities; iii) ancient, abandoned meanders of the rivers secchia and panaro with vegetation typical of wet areas; iv) water springs found at the boundary between highly pervious deposits and almost impermeable ones; only few of these springs survive owing to the overdraught from groundwater; v) fluvial terraces, both climatic and morphological, found along the boundary between the first apennine reliefs and the upper plain. 2.3. assessment of the scientific quality of geomorphological assets in order to make this assessment procedure as objective as possible, guide-lines are recommended for an easy choice and subsequent assessment of a particular asset. an important starting point is the geological and geomorphological knowledge of the study area. in particular, the scientific quality (q) of a geomorphological assets should be evaluated by means of several parameters, some of which are strictly 309methodological proposal for ... linked to the asset’s scientific specification whereas others are only indirectly connected to it. these parameters are: • experts’ knowledge (ce), which is linked to the geomophosite’s value for scientific research (s) and educational value (d); • area (a), related to the total area occupied by similar geomorphosites present in the stretch of territory considered; • rareness (r), related to the quantity of similar geomorphosites present in the stretch of territory considered; • degree of conservation (c), which depends on both natural and anthropogenetic factors; • exposure (e), in relation to visual impact; • added value (z), which is linked to the importance a geomorphosite assumes owing to non-geomorphological aspects which, nevertheless, increase its scientific value (e.g., tourism, ecological characteristics etc.). eventually, a value will be assigned to each parameter after it has been adequately weighted. scientific quality (q) is calculated by means of the following formula: q = ss + dd + aa + rr + cc + ee + zz where: s, d, a, r, c, e, z are the values and s, d, a, r, fig. 2 digital terrein model (dtm) with shadow filter. modello digitale del terreno (dtm) con filtro shadow. 310 c, e, z the respective weights. the latter, which range from 0 to 1, should be assigned to each parameter according to the guide-lines suggested. 1. experts’ knowledge (ce): experts are requested to express their opinion on two specific aspects which qualify geomorphosites from the scientific standpoint: 1) value for scientific research (s) and 2) educational value (d). 1.1. value for scientific research (s) 0.25 = low 0.50 = medium 0.75 = high 1.00 = very high the geomorphosite value for scientific research (s) can never be nil, otherwise a geomorphosite could not be considered as such. the value for scientific research should be assigned by considering the following guide-lines: • number and quality of the scientific publications concerning a geomorphosite; • whether there are research programmes in progress concerning in some way a specific site; • how representative a geomorphosite can be for the evolutional reconstruction of the territory it is inserted in; • whether a geomorphosite is important for the history of geomorphology in general; • the added value that the study of a geomorphosite can give to scientific research. 1.2. educational value (d) 0.00 = nil educational value 0.25 = low 0.50 = medium 0.75 = high 1.00 = very high the educational value should be determined by considering the following guide-lines: • representativeness of a particular form or process; • whether a given geomorphosite is quoted in educational textbooks as an asset of a certain importance; • whether a given geomorphosite is inserted in some tourist/educational itinerary and which is the educational level of such an itinerary; • whether it is known also outside the scientific world; • a geomorphosite is considered as having an educational value even if no educational material has so far been created on it. 2. area (a) this parameter is calculated as the area of the geomorphosite divided by the total area occupied by all the geomorphosites of the same type in the area considered, expressed as a percentage. 0.25 = <25% of the total area 0.50 = 25 to 50% of the total area 0.75 = 50 to 90% of the total area 1.00 = 90 to 100% of the total area the area value should be attributed by taking into account the following observations: p. coratza & c. giusti fig. 3 distribution of geomorphological sites in the study area. carta dei beni geomorfologi nell’area di studio. 311 • differently from other geological assets, the greater a geomorphosite is, the higher is its value. 3. rareness (r) rareness is assessed according to the quantity of similar elements present in the territory investigated. 0.25 = presence of numerous similar elements in the territory 0.50 = several similar elements in the territory 0.75 = very few similar elements in the territory 1.00 = unique example the rareness value should be assigned by following these guide-lines: • the rareness of a geomorphosite is a very important factor, especially if it is affected by eia or territorial planning procedures; • rareness increases if the geomorphosite bears witness to a morphoclimatic environment different from the present one. 4. degree of conservation (c) this parameter (c) may depend on both natural and anthropogenetic factors. 0.25 = poor state of conservation 0.50 = fair state of conservation 0.75 = good state of conservation 1.00 = excellent state of conservation the degree of conservation should be assigned by considering the following guide-lines: • the natural degree of degradation affecting a geomorphosite; • whether there are anthropogenetic elements which have altered or partially destroyed it; • presence of acts of vandalism; • whether there are structures that protect it from either natural or anthropogenetic agents. 5. exposure (e) exposure is considered as the visibility of a methodological proposal for ... fig. 4 zoom on the map of geomorphological sites and associated table. zoom sulla carta dei beni geomorfologici e tabella associata. 312 geomorphosite. 0.25 = the geomorphosite is heavily penalized 0.50 = the geomorphosite is penalized 0.75 = the geomorphosite is not particularly penalized 1.00 = the geomorphosite is not penalized at all the degree of exposure should be assigned by considering the following guide-lines: • a geomorphosite is suffocated by human development and, in order to see it properly, one must go very close to it; • reaching a geomorphosite may be very difficult; • presence of human structures which disturb the sight of a geomorphosite from far away; • presence of human structures which disturb the sight of a geomorphosite from a close position; • a geomorphosite is visible from all visual angles; • a geomorphosite is located in a panoramic point and emerges over the surrounding landscape. 6. “added value” (z) added value (z) is the “level of awareness” of a geomorphosite as such, owing also to non-geomorphological features, although geomorphology remains the main conditioning factor. 0.00 = nil added value 0.25 = added value of low importance, at a level of local curiosity 0.50 = added value of fair importance 0.75 = added value of high importance 1.00 = added value of fundamental importance, without which a specific asset would lose a considerable amount of its geomorphological value the added value should be assigned by considering the following guide-lines: • the geomorphosite has also a certain ecological and/or naturalistic value; • around the geomorphosite there are geological elements that further “enrich” it; • the geomorphosite has a certain tourist-economic value; • the geomorphosite has a certain historical-cultural value; • the geomorphosite lies within a protected area. the q value thus obtained is therefore normalised in order to obtain values of 0 to 1, according to the formula: q = qn / qmax. where: qn = scientific quality of a geomorphosite and qmax = maximum value that a geomorphosite can express. the values obtained are listed in tab. 1. 3. final remarks the proposed methodology makes use of gis for a quantitative assessment of geomorphological assets because it is a useful tool for optimising the decisionmaking procedure in territorial planning and in safeguarding geological heritage. the method developed in this work can be applied to advantage particularly in plain areas where anthropization has reached extreme levels. it can also counteract the widespread but mistaken belief that the landscape of the plain lacks any kind of interesting morphological elements. it must, however, be said that although the proposed methodology is quantitative, there is inevitably a degree of subjectivity in the assessment and quantification of environmental elements as their true value cannot really be measured. moreover, the allocation of values to the parameters used largely depends on the experience and sensitivity of the expert involved in assessment. the scientific quality of an asset is a purely indicative numerical quantity which can be subject to variations determined by the subjectivity of the operators p. coratza & c. giusti tab. 1quantitative assessment of the scientific quality of the geomorphological sites. valutazione quantitativa della qualità scientifica dei beni geomorfologici. and the general characteristics of the area under examination. but in spite of this, there is a real attempt to express each geomorphological asset’s scientific importance numerically so as to be able to compare them, even when there is some discrimination due to scientific dishomogeneity. in this context, the correct classification of natural and geomorphological assets together with an evaluation of their vulnerability is essential if we want to analyze the relationship between human activities and natural processes involving the modelling of the physical environment. this approach is an indispensable part of environmental impact assessment procedures, especially in the case of territorial priorities. in order to obtain the best results, it is advisable to have the method applied by a group of experts, acting independently, in order to give an estimate of each result, for example, by utilising the delphi method (balkey, 1969). references barba f.j., remondo j., & rivas v. (1997) propuesta de un procedimiento para armonizar la valoración de elementos del patrimonio geológico zubia, n. 15, pp. 11-20. bertacchini m., giusti c., marchetti m., panizza m. & pellegrini m. (eds.) (1999) i beni geologici della provincia di modena artioli editore, modena, 104 pp. coratza p. & giusti c. (2001) gis e valutazione di beni geomorfologici: un esempio nella pianura modenese (emilia romagna) geostorie, bollettino e notiziario del centro italiano per gli studi storicogeografici, università di firenze, cd-rom. castaldini d. (1989) evoluzione della rete idrografica centropadana in epoca protostorica e storica atti del convegno nazionale di studi “insediamenti e viabilità nell’alto ferrarese dall’età romana al medioevo” cento 8-9 maggio 1987. accademia delle scienze di ferrara e centro studi “g. baruffaldi” di cento, pp. 113-134. giusti c. (2001) il modello digitale del terreno (dtm) come supporto alla cartografia geomorfologica: l’esempio della pianura modenese (pianura padana, italia settentrionale in: g. scanu (ed.), cultura cartografica e culture del territorio, atti del convegno nazionale (sassari 12-13 dicembre 2000), bollettino dell’associazione italiana di cartografia, 111-112-113, pp. 409-417. giusti c. & gonzález-díez a. (2000) a methodological approach for the evaluation of impacts on sites of geomorphological interest (sgi),using gis techniques in: k.j. beek & m. molenaar (eds.), international archives of photogrammetry and remote sensing, proc. xix congress of the international society for photogrammetry and remote sensing, amsterdam 2000, vol. 23, part suppl. 7b, pp. 47-53. leopold l.b. (1969) landscape aesthetics nat. history, 10, pp. 35-46. linton d.l. (1968) the assessment of scenary as a natural resource scott. geogr. mag., 84, pp. 218-238. panizza m. (2001a) geomorphosites: concepts, methods and examples of geomorphological survey chinese science bulletin, 46, pp. 4-6. panizza m., marchetti m. & patrono a. (1995) a proposal for a simplified method for assessing impacts on landforms itc journal 1995-4, 324. panizza m. & piacente s. (1999) il concetto di “bene” nel paesaggio fisico in: m. bertacchini, c. giusti, m. marchetti, m. panizza & m. pellegrini (eds.), i beni geologici della provincia di modena, modena, artioli editore, 8 pp. rivas v., rix k., francés e., cendrero a., & brunsden d. (1997) geomorphological indicators for environmental impact assessment: consumable and nonconsumable geomorphological resources, geomorphology, 18, pp. 169-182. scarelli m. & poli g. (1999) quale strategia per una difesa attiva della natura?in: g. poli (ed.), geositi testimoni del tempo, regione emilia-romagna, bologna, pp. 100-103. various authors (1997) 2a relazione sullo stato dell’ambiente nella provincia di modena, provincia di modena, modena, mucchi editore. 313methodological proposal for ... imp.palmentola&lazzari proposal for a thematic itinerary on geomorphological sites along the western coast of the salento peninsula, southern italy giovanni palmentola1 & maurizio lazzari2 1università degli studi di bari dipartimento di geologia e geofisica, via orabona 4, bari g.palmentola@geo.uniba.it 2c.n.r.i.b.a.m., sezione di lagopesole, via federico ii, 85020 lagopesole (pz) lazzari@iisf.pz.cnr.it abstract: g. palmentola & m. lazzari, proposal for a thematic itinerary on geomorphological sites along the western coast of the salento peninsula, southern italy. (it isnn 0394-3356, 2005). researches carried out on the quaternary coastline modifications along the western salento peninsula of apulia, permitted to survey a succession of well-preserved geomorphological sites. these sites testify the events which interested the studied coastal sector during the quaternary time from mid-late pleistocene (mis 9?) to holocene (mis 1). the coastal sector of great landscape value, along which geomorphosites are exposed, is wide some kilometres from gallipoli town toward north as far as the punta d’alto lido promontory (locally known as the “broken mountain”). in particular, a series of landforms is exposed there, shaped by the sea and by sessile organisms which live along the sea cliffs, as well as by aeolian accumulation and deflation landforms. the variety of well-preserved and easy accessible landforms and their concentration in a not wide coastal sector constitute a good opportunity for both didactic and popularization of the processes which characterize the coastal dynamics, as well as the relative diagnostic elements. riassunto: g. palmentola & m. lazzari, proposta per un itinerario tematico attraverso siti geomorfologici lungo la costa occidentale della penisola salentina. (it isnn 0394-3356, 2005). nel corso di ricerche sulle modificazioni quaternarie della linea di riva lungo la fascia costiera della puglia, in corrispondenza della costa occidentale della penisola salentina è stata rilevata una successione di siti geomorfologici nei quali sono conservate chiare testimonianze degli eventi che, nel corso del quaternario dal pleistocene medio-superiore (mis 9?) all’olocene (mis 1), hanno interessato quel settore costiero. il tratto di pregio paesaggistico lungo il quale sono esposti i geomorfositi che si intende descrivere si estende per alcuni chilometri dalla città di gallipoli verso nord, fino al promontorio della punta d'alto lido (localmente nota come "montagna spaccata"). in particolare, lì é presente una serie di forme modellate dal mare e dagli organismi sessili che ne popolano le falesie, e di forme prodotte dalla deflazione e dall'accumulo eolico. la loro varietà, il buono stato di conservazione e la loro concentrazione lungo un settore poco esteso e facilmente percorribile fanno sì che tali siti costituiscano una opportunità per la didattica e la divulgazione dei processi che caratterizzano la morfogenesi costiera, come anche per l’individuazione dei relativi elementi diagnostici. keywords: southern italy, salento peninsula, late pleistocene, holocene, coastal geomorphology, sea-level change, geomorphosites. parole chiave: italia meridionale, penisola salentina, pleistocene superiore, olocene, geomorfologia costiera, variazione del livello del mare, siti geomorfologici. il quaternario italian journal of quaternary sciences 18(1), 2005 volume speciale, 115-123 1. introduction during researches partly supported by the italian ministry of scientific research (murst cofin 1998 and cofin 2000) about sedimentological and morphological evolution of italian beaches, a revision of data previous surveyed (palmentola & fiore, 1985) has been realized concerning middle and late pleistocene holocene sea level highstands along the western coast of salento peninsula (southern italy). due to both its relative tectonic stability from late pleistocene to the present, and its well-preserved lithostratigraphic and geomorphological features specially along its rocky coastal cliffs, salento peninsula represents a good area for the study of past sea level changes. a series of interesting features can be observed in a small area between gallipoli town and punta d’alto lido promontory along the ionian coast of the peninsula, where some sea-level high stands and some associated dune belts are exposed. because of their cultural, scenic and scientific attributes these features can be identify as “geomorphosites”, as well as because of their good state of preservation, peculiarity and patrimonial value (as evidence of the landscape regional evolution and climate variations), the studied area could constitute an example-locality for coastal geomorphology and dynamics studies in southern italy. intense human activity, in addiction to weathering, is presently threatening these sites and hindering their use for scientific and educational purpose. so that, this paper represents a preliminary step for protection of geomorphological sites through a proposal to incorporate them into the italian inventory of geosites, and propose them as a didactic thematic path for educational aims. in this way geomorphological assets becomes a patrimonial and cultural asset easily comprehensible, accessible and useful for both specialists and general public. 2. geological setting the salento peninsula is the southernmost part of the apulian foreland of both the apennines and dinaric 116 g. palmentola & m. lazzari orogenic systems (fig. 1). the foreland is represented by the outer apulian platform consisting of a variscan crystalline basement covered by approximately 6 km of mesozoic carbonate sediments. between the oligocene and miocene the foreland was affected by extensional tectonics (cristofolini et al., 1985; sella et al., 1988), due to its progressive deformation connected with the lithospheric subduction (doglioni et al., 1994), which produced a landscape characterized by a set of carbonate ridges ("serre") alternating with depressed areas. discontinuous pliocene and lower pleistocene transgressive deposits (calcareniti di gravina and calcareniti del salento formations) accumulated on mesozoic substratum into structural depressed areas. the geological history of salento peninsula ends with the deposition of middle and upper pleistocene sandy-clayey calcarenite deposits and aeolianites either on the mesozoic basement or on plio-pleistocene units. the more recent deposit diffusely outcropping in the peninsula is the "sabbie a brachiopodi" formation referred to an indeterminate post-sicil ian age (d'alessandro & palmentola, 1978; palmentola, 1987; d’alessandro et al., 1994). subsequently, other eustatic oscillations produced small and not much wide transgressions along the salento peninsula coastline leaving depositional evidences above all along the western slope. 3. geomorphological sites and thematic itinerary the thematic itinerary from gallipoli town as far as to punta d’alto lido cape towards north (fig. 2) permits to observe six different well-preserved sea level highstands. this last will be described according with an itinerary easy practicable along the main coastal route, starting from punta d’alto lido cliff and running towards gallipoli. the start-point (1st stop) is on the top of punta d’alto lido, on the left of the road to gallipoli, where 70m above s.l. an abrasion surface cut into mesozoic bedrock during early and middle pleistocene, is exposed. this surface is diffusely covered by “post-sicilian” sediments with terebratula scillae seguenza (“sabbie a brachiopodi” formation, d'alessandro & palmentola, 1978; d’alessandro et al., 1994) not older than mis 11, which represent the last wide marine transgression on the salento. with the subsequent regression the coastal zone of the peninsula reached approximately its present day contour being only partially modified, especially along its western side, by the following sea level fluctuations. the itinerary continues going down along a path until to 45-50 m above s.l. (2nd stop) where a successive sea level highstand is testify by a band of lithophaga boreholes and by thin well-cemented remains of a pebbly-sandy beach, in erosive contact on mesozoic limestone (melissano formation). chronostratigraphic position of this highstand can only be deduced from stratigraphic data: it is more recent and altimetrically lower than the "sabbie a brachiopodi" formation and older as well as higher than some calcarenites with strombus bubonius lamarck (mis 5e), both outcropping in the same area, along and near the same cliff. this means that this highstand is younger than mis 11or 9 and older than mis 5e. coming down along the same cliff the 3rd stop can be observed along a road trench, the “broken mountain” trench (fig. 3). the walls of this road cutting show morphological and geological evidences of two other sea level highstands. the first is testified by a well-preserved notch with an associated some meters wide wave-cut platform at 15 m above s.l.. the second, fig. 1 geographic location and schematic geologic map of the studied area. legend: 1) sands and clays locally alternated with bioclastic deposits (pleistocene); 2) calcarenites (plio-pleistocene); 3) cretaceous limestones of mesozoic basement (melissano formation). ubicazione geografica e carta geologica schematica dell’area di studio. legenda: 1) sabbie ed argille localmente alternate a depositi bioclastici pleistocenici; 2) calcareniti (plio-pleistocene); 3) calcari cretacei del basamento mesozoico (formazione di melissano). by sediments accumulated during a brief successive sea-level rise, which buries all the signs of the previous one. this sediments, topping at about 22 m above s.l., are constitute by pebbles and calcarenite mudstones with marine fossils (patella sp.), and are bored by lithophaga. some continental clinostratified coarse breccias, about 1.5 m thick, interbedded with a darkpink, silty-sandy deposit cover all the marine deposits. because of the altitude this last palaeo-sea level is correlable to a hardy eroded and degraded dune belt (fig. 4), which base is at about 35 m above s.l., outcropping in the hinterland of gallipoli on the orographic right of 117proposal for a thematic itinerary ... the canali stream (fig. 2). both the two sea-level highstands of the 3rd stop seem to be referable to two main oscillations of mis 7, where the younger one (mis 7a) is more elevated than the older (mis 7c), as occurs in other places of mediterranean countryes (zazo et al., 1993; 1994) and as is also suggested by the oxygen isotopic curve of shackleton et al. (1990). starting from “broken mountain” and running about one hundred meters towards gallipoli until to lido delle conchiglie, the fourth stop (fig. 5) can be reached where, to the bottom of punta d'alto lido cliff fig. 2 thematic itinerary map along the geomorphological sites. legend: 1) main stops; 2) sea cave; 3) outcrops of calcarenite with strombus bubonius lamarck.; 4) dune belts; 5) saracen tower; 6) active quarry into dunes; 7) dune belts ridge; 8) itinerary; 9) railway; 10) main roads; 11) canali stream; 12) coastline. carta dell’itinerario tematico lungo i siti geomorfologici. legenda: 1) stops principali; 2) grotta marina; 3) affioramento di calcareniti con strombus bubonius lamarck.; 4) cordoni dunari; 5) torre saracena; 6) dune in cava attiva; 7) dorsale del cordone dunare; 8) itinerario; 9) ferrovia; 10) strade principali; 11) torrente canali; 12) linea di costa. 118 g. palmentola & m. lazzari fi g. 3 – r oa d c ut tin g tr an sv er sa l t o p un ta d ’a lto l id o cl iff , w he re m ar in e ca lc ar en iti c m ud st on es (c a) o ut cr op in e ro si ve c on ta ct o n th e m es oz oi c lim es to ne s of m el is sa no f or m at io n (m .f .). th e p al ae o se a le ve l, p ro b ab ly r ef er ab le t o m is 7 a, is e vi d en ce d b y a li th op ha ga b an d (l ith ) t o th e to p o f p eb b ly c al ca re ni tic m ud st on es (c a) , ob se rv ab le o n th e le ft o f p ic tu re . th es e d ep osi ts c ov er a lo w er a nd n ot w el l p re se rv ed n ot ch a nd t he a ss oc ia te d w av ecu t p la tf or m (t hi ck b la ck li ne ) t es tif yi ng a n ol d er s ea le ve l h ig hs ta nd (m is 7 c? ). a ll th e su cc es si on p as se s up w ar d t o cl in os tr at ifi ed c on tin en ta l b re cc ia s (b r) . tr in ce a st ra d al e tr as ve rs al e al la fa le si a d i p un ta d ’a lto l id o, d ov e af fio ra no fa ng hi c al ca re ni tic i ( c a) in c on ta tt o er os iv o su l s ub st ra to m es oz oi co d ei c al ca ri d i m el is sa no (m .f .). il p al eo li ve llo d el m ar e, o ss er va b ile s ul la s in is tr a d el la f ig ur a, è p ro b ab ilm en te r ife rib ile a l m is 7 ° ed è e vi d en zi at o d a un a fa sc ia d i f or i d i l ito fa gi p os ta a l t op d el le c al ca re ni ti ci ot to lo se (c a) . t al i d ep os iti c op ro no u n so lc o d i b at tig ia e la r el at iv a no n b en c on se rv at a p ia tt af or m a d i a b ra si on e m ar in a (li ne a ne ra ) p iù b as sa e p iù v ec ch ia , t es tim on ia nd o co sì u n p iù v ec ch io a lto s ta zi on am en to d el li ve llo d el m ar e (m is 7 c? ). tu tt a la s uc ce ss io ne p as sa v er so l’ al to a d u na b re cc ia c on tin en ta le c lin os tr at ifi ca ta (b r) . 119proposal for a thematic itinerary ... fig. 4 higher and older very degraded dune belt outcropping in the hinterland of gallipoli. cordone dunare degradato più alto e più vecchio affiorante nell’hinterland di gallipoli. fig. 5 aerial photo of lido delle conchiglie punta d'alto lido area. legend: 1) top abrasion surface with remains of “calcareniti del salento formation” (early pleistocene); 2) itinerary; 3) stops with meaningful outcrops of morphological and geological evidences of middle-late pleistocene sea level oscillations. ripresa aerea dell’area del lido delle conchiglie-punta d’alto lido. legenda: 1) superficie d’abrasione marina con lembi della formazione delle calcareniti del salento (pleistocene inferiore); 2) itinerario; 3) stops con i principali affioramenti di evidenze geologiche e geomorfologiche delle oscillazioni del livello del mare del pleistocene medio-superiore. 120 at 8 m above s.l., remains of a fourth highstand are well preserved (fig. 6). they are represented by a band of lithophaga boring the cretaceous limestones of the cliff, and by remains of a proximal pebbly beach deposit, laterally passing to sandy-calcarenite deposits with nests of strombus bubonius lamarck. this calcarenite, corresponding to mis 5e (“tyrrhenian phase”, mirigliano, 1956), can be altimetrically correlated with a thick and well-preserved sandy dune belt, with the base at 15-20 m above s.l., outcropping in the hinterland of gallipoli (fig. 2). these dunes are well exposed in a quarry and along a railway cutting (fig. 7) easy reachable running the road from gallipoli to alezio. the morphological effects of a successive 5th highstand can be studied along the coastal road between punta d’alto lido and gallipoli (5th stop) represented by a seaward surface wave-cut at about 2 m above s.l. into the calcarenites with strombus bubonius lamarck. the age of this abrasion event has been assigned to mis 5a (cotecchia et al., 1971) by mean of a sample of cladocora coespitosa (linnè) found in some coastal sediment over the calcarenites, which showed a radiometric age of 85 ka. this datum was afterwards corroborated by dai pra & hearty (1988; 1989) by means of isoleucine epimerization ratio of some helix sp. (70 ka) collected in a thin red soil level between the abrasion surface and an overlaying holocene yellowish dunes. this last situation is still exposed in the neighbourhood of torre sabea (6th stop), 1.5 km north of gallipoli, where a beautiful saracen watch-tower built of xi century is also observable (fig. 8). after the abrasion of the surface of 2 m a.s.l., a cold climatic phase (about 20 ka) induced a regression of sea-level towards the quaternary eustatic minimum of -120 m below its present position. this retreat was following by a rapid transgression, shown also in the holocene sea-level fluctuation curves reconstructed by dai pra & hearty (1989) and dini et al., (2000) for the coasts of southern apulia. the transgression ended about 6000-7000 years bp with the sea-level highstand corresponding to the peak of mis 1 (versilian transgression). this stage corresponds to the so-called “climatic optimum” (bertolani marchetti, 1985; rossignol-strick et al., 1992; yan & petit maire, 1994) and has been characterized by the warmest and most humid climatic conditions during the holocene (atlantic chronozone). the holocene yellowish dunes elongated roughly parallel to the present coast line, contain several pulmonate gastropods helix spp., radiometrically dated 6700-5300 yr b.p (cotecchia et al. 1969; hearty & dai pra, 1989; dini et al., 2000), have their base here and there submerged and are in many places partially covered or flanked by subactual dunes. g. palmentola & m. lazzari fig. 6 outcrops of pebbly beach and calcarenites deposits (pbd) at the bottom of the "broken mountain" cliff and in a sea cave, in erosive contact on mesozoic basement (melissano formation, mfm). laterally this deposit, corresponding to sea level highstand of mis 5e, grows thin as far as to be replaced by an abrasion marine surface (black striped area). affioramenti di spiaggia ciottolosa e depositi calcarenitici (pbd) nella parte alta della falesia della “montagna spaccata” in una grotta marina, in contatto erosivo sul substrato mesozoico (formazione di melissano, mfm). lateralmente questo deposito, corrispondente allo stage 5e, si assottiglia fino ad essere sostituito da una superficie di abrasione marina (area tratteggiata in nero). 4. conclusions the sites above outlined seem important to be preserved because of the rare and great value evidences they show. it is not usual to find in a relative small area such an important succession of geological and geomorphological events, testifying sea level variations fundamentally due to climatic changes occurred from the mid-pleistocene to holocene. in figure 9 such events are summarized by means of two ideal geomorphological profiles crossing the different landforms and deposits described in the main five stops. in short, after the deposition of the post-sicilian sabbie a brachiopodi formation, six eustatic oscillations produced between 45-50 m and 2 m above s.l. morphological and geological evidences of as many highstands, referable to mid-late pleistocene (mis 11 or 9?, 7c, 7a, 5e and 5a) and holocene (mis 1). 4.1 protection and valorization of geomorphosites all the geological and geomorphological evidences represent an irreplaceable scientific, didactic, environmental and cultural heritage and therefore an added value for this territory, which we believe must be preserved. unfortunately the sites are today seriously threatened by modifications and obliteration due to the anthropic aggression, as quarries in the sandy dune belts, road cuttings, urbanization and other human interventions. their protection is necessary because, with respect to a cultural asset strictu sensu, geomorphosites are not restorable and reproducible. different ways to opposite against their irreversible deleting and submitting the sites to active and pas121proposal for a thematic itinerary ... fig. 7 outcrop of sandy dune belt (db) some meters thick in a railway cutting in the hinterland of gallipoli. the photo shows also the classic curve shape of the dune belt with the axis elongated perpendicularly to the cutting. affioramento del cordone dunare sabbioso (db) spesso alcuni metri in corrispondenza di una trincea ferroviaria nell’hinterland di gallipoli. la foto mostra inoltre il classico profilo curvilineo della duna con l’asse allungato perpendicolarmente alla trincea. fig. 8 the figure evidences the outcrop of the calcarenite with strombus b. lamarck. (castb) near torre sabea, on which an evident and wide wave-cut platform at 2 m a.s.l. was shaped probably during the mis 5a. subsequently, a holocene dune belt with helix sp. was deposited on the same wavecut platform. la figura evidenzia l’affioramento della calcarenite con strombus b. lamarck. (castb) nei pressi di torre sabea, sulla quale si è modellata una evidente ed estesa superficie d’abrasione marina posta a 2 m s.l.m. e probabilmente riferibile allo stage 5°. successivamente un cordone dunare con helix sp. si è depositato su tale piattaforma. sive protection could be adopted. a first conservation strategy (sensu reynard, 2003), could be to propose their inserting in an inventory catalogue of the italian geotopes, binding the sites in order to submit them to active protection limiting the human activity. the itinerary along the main proposed stops should be insert in a context of tourist and educational flow, valorizing still more their scientific and didactic great value also by means of showcases, in which geomorphological landscape evolution during last different climatic phases would be schematically represented and explained. acknowledgements this work has been partially supported by the murst-cofin2000 project (national scientif ic coordinator: prof. g. fierro university of genova; local scientific co-ordinator: prof. g. palmentola university of bari). the authors warmly thank antonio cendrero and emmanuel reynard for their useful suggestions, critical reading and improvement of the manuscript. references bertolani marchetti d. (1985) pollen paleoclimatology in the mediterranean since messinian time in: d.j. stanley & f.c. wezel (eds), geological evolution of the mediterranean basin, springer, new york, pp. 525-543. carton a., cavallin a., francavilla f., mantovani f., panizza m., pellegrini g.b. & tellini c. (1994) ricerche ambientali per l’individuazione e la valutazione dei beni geomorfologici. metodi ed esempi il quaternario, 7(1), pp. 365-372. cotecchia v., dai pra g. & magri g. (1969) oscillazioni tirreniane ed oloceniche del livello del mare nel golfo di taranto corredate da datazioni con il metodo del radiocarbonio geol. appl. e idrog., 4, pp. 93-148. cotecchia v., dai pra g. & magri g. (1971) sul tirreniano della costa ionica salentina (puglia). datazione di un campione di coralli con il metodo del 230th/234u geol. appl. e idrog., 6, pp. 105112. cristofilini r., ghisetti f., scarpa r. & vezzani l. (1985) character of the stress field in the calabrian arc and southern apennines (italy) on deduced by 122 g. palmentola & m. lazzari fig. 9 – geomorphological schematic profile along the main stops of the thematic itinerary from lido conchiglie-punta d'alto lido cliff to gallipoli-torre sabea, in which the more meaningful outcrops of sea level high stands and marine landforms are represented. in a) it is represented the situation of torre sabea (stop 5), while in b) the morphological and geological evidences observable in other three stops (projected from south) are shown. legend: 1) holocene dune belt (mis 1); 2) continental clinostratified breccias; 3a) coarse pebbly and calcarenitc beach deposits (mis 5e); 3b) calcarenites with strombus bubonius lamarck. (mis 5e); 4) calcarenitic mudstones with lithophaga band to the top (mis 7a); 5) pebbly beach and calcarenites remains (mis 9?); 6) cretaceous limestones. profilo geomorfologico schematico lungo i principali stops dell’itinerario tematico dalla falesia di lido delle conchiglie-punta d’alto lido a gallipoli-torre sabea, in cui vengono rappresentati gli affioramenti più significativi delle forme marine e degli alti stazionamenti del livello del mare. in a) viene rappresentata la situazione di torre sabea (stop 5), mentre in b) sono mostrate le evidenze geomorfologiche e geologiche visibili in altri tre stops (proiettati da sud). legenda: 1) cordone dunare olocenico; 2) brecce continentali clinostratificate; 3a) depositi di spiaggia calcarenitici e ciottolosi (mis 5e); 3b) calcareniti con strombus bubonius lamarck. (mis 5e); 4) fanghi calcarenitici con una fascia di litofagi nella parte superiore (mis 7°); 5) lembi residui di calcareniti ciottolose (mis 9?); 6) calcari cretacici. geological, seismological and volcanological information tectonophysics, 117, pp. 39-58. d’alessandro a. & palmentola g. (1978) sabbie a brachiopodi, una nuova unità del salento leccese (aspetti litostratigrafici e paleoambientali rivista italiana di paleontologia e stratigrafia, 84(4), pp. 1083-1120. d’alessandro a., mastronuzzi g., palmentola g. & sanso' p. (1994) pleistocene deposits of salento leccese (southern italy): problematic relationships boll. soc. paleont. it., 33 (2), pp. 257-263. dai pra g. & hearty p.j. (1989) variazioni del livello del mare sulla costa ionica salentina durante l’olocene. epimerizzazione dell’isoleucina in helix sp. mem. soc. geol. it., 42, pp. 311-320. dini m., mastronuzzi g. & sanso' p. (2000) the effects of relative sea level changes on the coastal morphology of southern apulia (italy) during the holocene in: o. slaymaker (ed.): geomorphology, human activity and global environmental change, john wiley & sons, ltd., pp. 43-45. doglioni c., mongelli f. & pieri p. (1994) the puglia uplift (se italy): an anomaly in the foreland of the apenninic subduction due to buckling of a thick continental lithosphere tectonics, 13, pp. 13091321. hearty p.j. & dai pra g. (1992) the age and stratigraphy of middle pleistocene and younger deposits along the gulf of taranto (southern italy) journal of coastal research, 8 (4), pp. 82-105. mirigliano g. (1956) il tirreniano di gallipoli (lecce) atti iv congr. inter. quater. (roma-pisa, 1953), 2. palmentola g. (1987) lineamenti geologici e geomorfologici del salento leccese quad. ric. centro studi ing., lecce, 11, pp. 7-30. palmentola g. & fiore s. (1985) inquadramento geografico e morfologico del salento. in: c. battista, f. boenzi, s. fiore, d. novembre, g. palmentola & l. pennetta (eds.), lineamenti geografici del salento leccese, conv. annuale gruppo nazionale di geografia fisica e geomorfologia, lecce, 41 pp. panizza m. (2001) geomorphosites: concept, methods and examples of geomorphological survey chinese science bullettin, 46, suppl. bd., pp. 4-6. reynard e. (2003) geosite in: a. s. goudie (ed): encyclopedia of geomorphology, london, routledge, pp. 440. rossignol-strick m., planchais n., paterne m. & duzer d. (1992) vegetation dynamics and climate during the deglaciation in the south adriatic basin from a marine record. quarter. sci. rev., 11, pp. 415423. shackleton n.j., berger a. & peltier w.r. (1990) an alternative astronomical calibration on the lower pleistocene time scale based on odp site 677 trans. r. soc. edinburgh, earth science 81, pp. 251-261. sella m., turci c. & riva a. (1988) sintesi geopetrolifera della fossa bradanica (avanfossa della catena appenninica) memorie società geologica italiana, 41, pp. 87-107. yan z. & petit maire n. (1994) the last 140 ka in the afro-asian arid-semiarid transitional zone paleogeogr.paleoclim.paleoecol., 110, pp. 217233. zazo c., goy j.l., dabrio c.j., bardaji t., somoza l. & silva p.g. (1993) the last interglacial in the mediterranean as a model for the present interglacial global and planetary change 7, pp. 109117. zazo c., goy j.l., hillaire-marcel c.l., dabrio c.j., hoyos m., lario j., bardaji t., somoza l. & silva p. (1994) variaciones del nivel del mar: estadios isotopicos 7.5 y 1 en las costas peninsular (s y se) e insulares españolas aequa, monografias 2, pp. 26-35. 123proposal for a thematic itinerary ... sess 1_160211.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 sea level change in italy until 400 ka: comparing global sea level curves with observed data fabrizio antonioli enea casaccia, roma corresponding author: f. antonioli <fabrizio.antonioli@enea.it> abstract: antonioli f. sea level change in italy. (it issn 0394-3356, 2011) this paper report a review of the sea level change data published for italy for the last 400 ka and the markers used to constrain the curves. in particular it is underlined the importance to distinguish between global, local and predicted sea level curves. riassunto: antonioli f. sea level change in italy. (it issn 0394-3356, 2011) in questo lavoro viene effettuata una review di quanto recentemente pubblicato in italia in relazione alle variazioni di livello del mare a partire da 400 ka. viene distinta e spiegata la differenza tra curve globali, locali e predette. le prime basate sui dati provenienti da foraminiferi campionati sul fondo degli oceani e analizzati rispetto al rapporto isotopico dell'ossigeno. le seconde basate sui dati osservati datati e misurati su markers costieri, le ultime ricostruite attraverso complessi modelli geofisici. key words: relative sea level, italy parole chiave: livello relativo del mare, italia 1. introduction sea level change can be reconstructed from dated fossil coral reef terraces, and these data are complemented by a compilation of global sealevel estimates based on deep-sea oxygen isotope ratios at millennial-scale resolution or higher (specmap, imbrie et al., 1988). because of the lack of coral reefs in the mediterranean sea, results on late quaternary sea-level changes have been difficult to obtain in comparison with typical sites such as barbados) the huon peninsula, tahiti florida, and others. on the contrary the very low tidal range of italian seas offers a good opportunity to produce precise palaeo-sea level curves. sea level change along the italian coast during last 10 ka is the sum of eustatic, glacio-hydro-isostatic, and tectonic factors. the first is time-dependent while the latter two also vary with location (lambeck et al., 2004a). this means that at the same time slices the relative sea level (the sum of 3 different movements) should be different in different coastlines. for any palaeo reconstruction of an ancient coastline it is necessary to take into account all components. it is important to distinguish beteween global sea level curves (s.l.c.), local s.l.c. or predicted s.l.c., costrained using geophysical models. aim of the paper is to put together all sea level change data collected for italian seas to be compared with global sea level curves. 1.1. global s.l.c. global s.l.c. are generally constrained analyzing δ18o ratio on fossils foraminifera series, sampled on mud core of the ocean bottom. the δ18o ratio infact, show a direct correlation with sea level variations, and allows to calculate the sea level changes. this kind of curves do not take in account any isostatic component. the most recently published s.l.c. are reported in woalbreak et al. (2002) show that robust regressions can be established between relative sea-level data and benthic foraminifera oxygen isotopic ratios from the north atlantic and equatorial pacific ocean over the last climatic cycle. siddal et al. (2003) s.l.c. came from red sea 1.2. predicted and local s.l.c. to constrain a local s.l.c. it is necessary to collect and date fossils shells, biological markers, living at intertidal environment (i.e. dendropoma reef) or salt marsh lagoon are considered the best: maximum error bars infact is the mean annual tide. precose archaeological markers as fishtanks are also used (lambeck et al., 2004b) predicted slc are buitl from geopysical model (lambeck et al., 2004a) and take in consideration isostatic movements, calculation of tectonic ratea are based on predicted slc checked on stable area (antonioli et al., 2009) 11 13 12 f. antonioli 13 ms. received: testo ricevuto il 2. conclusion a general agreement for the holocene and mis 5.5, 7.1, 7.3, 7.5 italian aged fossil marine deposits or submerged speleothem are found (table 1). discrepancies in sea level observations on stable area with global data are found for mis 5.1-5.3, all that could be explained by the influences of glaciohydro-isostasy (potter et al., 2004). mis 3 are not preserved in cores as marine facies. the first two rows of table 1 shows the differences in isostasy for the same time slice in different stable coastal areas references amorosi a., colalongo m.l., pasini g., preti d. (1999) sedimentary response to late quaternary sea-level changes in the romagna coastal plain (n. italy). sedimentology, 46, 99–121. amorosi a., colalongo m.l., fiorini f., fusco f., pasini g., vaiani s.c., & sarti g. (2004) palaeogeographic and palaeoclimatic evolution of the po plain from 150-ky core records. global and planetary change, 40, 55–78. antonioli f., ferranti l., fontana a., amorosi a.m., bondesan a., braitenberg c., dutton a., fontolan g., furlani s., lambeck k., mastronuzzi g., monaco c., spada g., stocchi p. (2009) holocene relative sea-level changes and vertical movements along the italian coastline. quaternary international 221, 37-51. antonioli f., bard e., silenzi s., potter e. k., improta s. (2004) 215 kyr history of sea level based on submerged speleothems. global and planetary change, 43, 57-78. bard e., antonioli f., silenzi s. (2002) sea-level during the penultimate interglacial period based on submerged stalagmite from argentarola cave (italy). earth and planetary science letters 196/3-4, 135146. belluomini g., caldara m., casini c., cerasoli m., manfra l., mastronuzzi g., palmentola g., sanso p., tuccimei p.,vesica p.l. (2002) the age of late pleistocene shorelines and tectonic activity of taranto area, southern italy. quaternary science reviews 21, 525 –547. carboni g., bergamin l., di bella l., esu d., pisegna e., antonioli f., verrubbi v., (2010 palaeoenvironmental reconstruction of late quaternary foraminifera and molluscs from the enea borehole (versilian plain, tuscany, italy), quaternary research, 74, 265-276 dorale j., p. onac b., fornós j., ginés j., ginés a., tuccimei p., david w. & peate d. (2010) sea-level highstand 81,000 years ago in mallorca, science, 327, 860-863. dutton a., antonioli f., bard e., m. esat t., lambeck k, mcculloch m. (2009) phasing and amplitude of sea level and climate change during the penultimate interglacial. nature geosciences, 355-359. doi: 10.1038/ngeo470. ferranti l., et al. (2006) markers of the last interglacial sea level highstand along the coast of italy: tectonic implications. quaternary international 145146, 30-54. iannace a., romano p., santangelo n., santo a., tuccimei p. (2001) the ois 5c along licosa cape promontory (campania region, southern italy): morphostratigraphy and u/th dating. z. geomorph. n.f. 45 3, 307-319. iannace a., romano p., tuccimei p. (2003) u/th dating and geochenmistry of carbonate concretions associated with upper pleistocene fossils shorelines of the sorrento peninsula (conca dei marini, southern italy). il quaternario 16 bis, 38-49. imbrie j., hays j.d., martinson d.g., mcintyre a., mix a.c., morley j.j., pisias n.g., prell w.l. & shackleton n.j. (1984) the orbital theory of pleistocene climate: support from a revised chronology of the marine d18o record. in: a.l. berger et al. (eds), milankovitch and climate, part 1, reidel pub. co, 269-305. lambeck k., antonioli f., purcell a. & silenzi s. (2004a) sea level change along the italian coast for the past 10,000 yrs. quat. science revue. 23, 15671598. lambeck k., anzidei m., antonioli f., benini a. & esposito a. (2004b) sea level in roman time in the central mediterranean and implications for modern sea level rise. earth and planetary science letter. lambeck k, antonioli f., anzidei m., ferranti l., leoni g., scicchitano g. & silenzi s. (2011, in print) sea level change along italian coast during holocene and a proiection for the future. journal of quaternary international. potter e. k., lambeck k. (2004) reconciliation of sea-level observations in the western north atlantic during the last glacial cycle. earth and planetary science letters 217, 171-181. riccio a., riggio f., romano p. (2001) sea level fluctuations during oxygen isotope stage 5: new data from fossil shorelines in the sorrento peninsula (southern italy). z. geomorph. n. f. 451, 121-137. siddall m., rohling e. j., almogi-labin a., hemleben ch., meischner d., schmelzer i., (2003) sea level fluctuations during the last glacial cycle. nature 423, 853-858. waelbroeck c., labeyrie l., michel e., duplessy j.c., lambeck k., mcmanus j.f., balbon e., labracherie, m. (2002) sea-level and deep water temperature changes derived from benthic foraminifera isotopic records. quaternary science reviews 21, 295-305. sea level change in italy. january 14, 2011 14 gennaio 2011 imp.massoli&novelli the main geomorphosites of the egadi islands (sicily, italy) raniero massoli-novelli via della mendola, 85 00135 roma, email: massoli@tiscali.it abstract: r. massoli-novelli, the main geomorphosites of the egadi islands (sicily, italy). (it issn 0394-3356, 2005). this article describes the main geological and geomorphological features of the three main egadi islands: favignana, levanzo and marettimo. these islands, which are essentially made up of mesozoic carbonate rocks, are considered as the continuation in the sea of the north-western sicilian chain. in addition, the main geomorphosites of these three islands are identified for the first time: these are the numerous, significant coastal caves. particular emphasis is given to natural and anthropogenetic geomorphosites related to the pleistocene bioclastic calcarenite caves present in favignana, an ancient site of intense quarrying activities. riassunto: r. massoli-novelli, i principali geomorfositi delle isole egadi (sicilia, italia). (it issn 0394-3356, 2005). vengono evidenziate le principali caratteristiche geologiche e geomorfologiche delle tre maggiori isole delle egadi, favignana, levanzo e marettimo, costituite essenzialmente da rocce carbonatiche mesozoiche e considerate la prosecuzione in mare verso ovest della catena nordoccidentale della sicilia. vengono poi individuati per la prima volta i principali geomorfositi delle tre isole, in gran parte costituiti dalle numerose e rilevanti grotte costiere. particolare risalto viene anche dato ai geomorfositi, naturali ed antropici, relativi alle cave di calcareniti bioclastiche pleistoceniche esistenti a favignana, luogo di antica ed intensa attività estrattiva. keywords: geomorphosites, calcarenite, egadi islands, italy. parole chiave: geomorfositi, calcarenite, egadi, italia. il quaternario italian journal of quaternary sciences 18(1), 2005 volume speciale, 137-143 1. introduction and general geological setting the egadi archipelago is formed by three main islands – favignana, levanzo and marettimo – and the islets of maraone and formica. all these islands are geologically linked to the adjacent mainland. in other words, the egadi are the continuation in the sea of the backbone chain of northwestern sicily (fig. 1). the basic geological composition of this archipelago corresponds to calcareous-dolomitic rocks, ranging in age from the triassic to the miocene. subsequently, layers of sandstones were deposited on top of the carbonate rocks. in particular, bioclastic calcarenites crop out abundantly on the largest island of favignana. they are typical poorly cemented, easily workable, yellowish calcareous limestones rich in pelecypods, especially the pecten genus. owing to these characteristics, since the 1700s this stone has been called “tufo” (i.e., tuff; a similar wrong definition has been given to the stones of matera in basilicata). these limestones have been intensely quarried through time. no detailed studies have been ever carried out on this interesting stone, although it appears to be quite similar to the proximal bioclastic calcarenite outcrops of the lower pleistocene along the coast of marsala (ruggieri et al., 1975) and in san vito lo capo (antonioli et al., 1994). the presence of compact calcareous-dolomitic rocks explains the two essential geomorphological characteristics of the egadi islands: cliffs and high reliefs in all the islands, especially in the two smaller ones, and many large caves. the highest peak is mt. falcone in marettimo, which reaches a height of 686 m. not only is this island the furthest from the sicilian coast but it is also the one most affected by tectonic processes, with numerous overthrusts and transcurrent faults (abate et al., 1995, 1996). favignana is the largest of the egadi islands. owing to its shape, it is compared to a butterfly: at the centre of the island, a north-south ridge of mesozoic calcareous-dolomitic rocks stands out, reminiscent of a butterfly’s body. at the sides, calcareous marine sediments to the west and arenaceous marine sediments to the east were subsequently deposited on these hard and compact carbonate rocks, forming two small plains: the butterfly’s wings. in the plain to the east, abundant strata of pleistocene bioclastic calcarenites crop out (the “tufo” or favignana stone previously mentioned). these rocks, between a few centimetres to about 30 cm thick, show a generally sub-horizontal bedding. the calcarenite is a marine, very rich in fossils (pelecypods, corals, remains of fish, etc.) calcareous sandstone. the isle of levanzo, which is the smallest of the three main egadi islands, is famous for its rugged land138 r. massoli-novelli scape and absence of beaches. also marettimo, the most mountainous of the egadi islands, has practically no beaches. from the geological standpoint, it is older than the other two islands, since it is mostly composed of triassic-lias limestones and dolostones (incandela, 1996). because of its position in the open sea, surrounded by a deep sea floor, marettimo is often windswept and pounded by westerly and northerly breakers. as a consequence, this island has a much more jagged coastline than levanzo and favignana. 2. the main geomorphosites of the egadi islands the main geomorphosites identified on each island are here below illustrated with progressive numbers, with reference to the map in fig. 1. 2.1 isle of favignana the excursion starts from the south, from the “scindo passo” cliff, where a long vertical rock wall of tectonic origin is found. this area is characterised by fig. 1 – schematic geological map of the egadi islands. numbers refer to the geomorphosites listed in the text. cartina geologico-schematica delle isole egadi: i numeri si riferiscono ai geomorfositi elencati nel testo. the presence of large, unstable limestone boulders which have caused several rock falls. this cliff and the rock fall materials make up an interesting geomorphosite (1), easily observable from the asphalt road. to the south, another geomorphosite is found: the “preveto islet” (2), which is made up of mesozoic limestones. this geosite is the obvious continuation into the sea of the favignana ridge. to the west, the perfectly circular natural inlet of cala rotonda is found. inside it, a small geomorphosite named the “arch of ulysses” (3) is located. this is a remarkable, thin natural arch rising from the sea. all the western coast is made up of vast sub-horizontal outcrops of limestones and calcareous breccias and is an important example of an ancient sub-aerial plain which was later reworked by the sea. it contains innumerable microforms of the karren and pot-hole types, which are particularly visible in the cala grande area. it is therefore possible to identify a karst coastal plain of the cala grande geomorphosite (4). to the north, high on a cliff towards punta faraglione, there are two large karst caves very close to each other. the one known as “grotte dell’ucceria” has two entrances and important prehistoric artefacts were found inside it. this two-cave complex makes up an important karst-type geomorphosite (5). we shall now describe the eastern side of favignana, with its calcarenite sandstones and the previously mentioned “tufo” quarries. for many centuries this “tufo” rock was exploited as the most important economic activity of this island, together with fishing and farming. the quarrying of this material goes back to very ancient times – certainly roman times – but the peak of quarrying activities dates back to the period between the 17th and 19th centuries. many palaces in tunis were built with favignana “tufo”. the same rock was used for the reconstruction of messina after it had been destroyed by the earthquake of 1908. indeed “tufo” has always typified the isle of favignana. apart from making up most of the geological landscape, it can be observed everywhere as building material: numerous houses and stone walls dividing land properties are made of it. there are about 150 existing quarries, of which most are open cast quarries or pit-like ones. on the other hand, other quarries have been dug out underground. four groups of caves, which are the most interesting and representative of several types are here proposed as geomorphosites: “ancient quarries in the village of favignana” (6), in particular those next to the security prison. although there is no certainty about their age, it is 139the main geomorphosites of ... assumed that most of them were excavated between the 17th and the end of the 19th century. these sites are now utilised as gardens and small orchards; “ancient coastal quarries of san nicola” (7), whose floors have now been covered by sea advancement for a depth of about 20 cm, and where the ancient submerged excavation frames are still perfectly visible (fig. 2). the calcarenites are very rich in fossils here, especially in pecten specimens. it is assumed that they were exploited between the middle ages and the last century, in analogy with the nearby coastal quarries of bioclastic calcarenites of san vito lo capo, which are also submerged (antonioli et al., 1994). recently, in the area of san nicola, the skeleton of a cetacean in a horizontal position, embedded in calcarenite, was found, together with layers of pelecypod shells. this large marine mammal was probably grounded on the beach (massoli-novelli, in press); “ancient/modern quarries of cala rossa” (fig. 3), here different types of quarries are found: coastal open cast quarries (8) and underground excavated quarries (9), with the presence of numerous, considerable sedimentation structures, in particular cross-bedding, which were exploited manually in the past centuries; “recent quarries of setteminne-torretta” (10), these are often large pit-type quarries, up to 30 m deep, which have been worked by means of cutting machines. many of them were recently abandoned, although some are still active in order to guarantee the required material for restoring the many old houses built of calcarenite stones. as has been suggested by many authoritative sources, the favignana “tufo” quarries should be reclaimed for cultural and geotourism purposes, as, for example, a quarry museum or an earth museum. furthermore, in setteminne there are two large contiguous quarries which together make up an interesting geomorphosite (11). they are both pit-type quarries; the first one is abandoned but it still has a typical residual fig. 2 – aerial view of the cala rossa ancient “tufo” quarries (pleistocene bioclastic calcarenite), isle of favignana: the resulting landscape is similar to that of an abandoned city (photo by tamagnini). le antiche cave di “tufo” (calcarenite bioclastica pleistocenica) di cala rossa, isola di favignana, osservate dal cielo: il paesaggio che ne deriva risulta simile a quello di una città abbandonata (foto tamagnini). 140 pillar of the excavation activities (fig. 4), whereas the second one has a regular square shape which would be very suitable as a stage for open-air summer shows by night. along the south-eastern coast another natural geomorphosite is found: the “grotta perciata” (12). here the sea hollowed out a cave which has partially collapsed, leaving only an interesting arch and a little shelter for two or three fishing boats. further to the south-east, the “cala azzurra” is found, which is another coastal geomorphosite (13) of great scenic value, with the only sandy beach of the island, which is divided into two parts by an outcrop of compact calcarenite. finally, after this series of prevalently coastal geomorphosites, an outstanding internal site is found on top of the mesozoic carbonate ridge at the centre of the island: mount santa caterina (14), at an altitude of 314 m a.s.l., where the fort bearing the same name rises and from which a spectacular view over the village, the harbour and the calcarenite quarries can be enjoyed. 2.2 isle of levanzo levanzo is a small hamlet located in a very beautiful inlet on the island’s southern coast. as soon as one arrives there, an interesting geomorphosite (1) is immediately noticeable: it is made up of a large, steep, tectonic pinnacle of mesozoic carbonate rock, subsequently modelled by erosion, which hangs over the sea and the hamlet. following the path to the west, another similar geomorphosite (2) is immediately visible: the well-known “faraglione di levanzo”, an imposing block of mesozoic dolomitic limestone, which was first isolated by tectonics and then by sea erosion. proceeding uphill towards the “grotta dei genovesi”, one crosses an area named “la fossa”, which is another geomorphosite (3) corresponding to a karst depression, the only one on the island. this site was cultivated up to a few years ago r. massoli-novelli fig. 3 – the s p e c t a c u l a r pilastro calcarenite quarry, in setteminne of favignana. this is a recently opened quarry, as witnessed by the marks of the digging machines. it has now been abandoned and, hopefully, should be reclaimed and appraised (photo by massoli-novelli). la spettacolare cava di calcarenite del pilastro, in località setteminne di favignana, una cava recente come mostrano i segni delle macchine tagliatrici, abbandonata da poco ed in attesa di una auspicabile va lo r i z zaz ione (foto massolinovelli). fig. 4 – ancient calcarenite coastal quarry in san nicola, isle of favignana. it probably goes back to medieval times and its floor is at present under 20-30 cm of sea water (photo by massoli-novelli). antica cava costiera di calcarenite a san nicola, isola di favignana, di età probabilmente medioevale, dove il pavimento è oggi ricoperto da 20-30 cm di acqua di mare (foto massolinovelli). 141 and the residual soil, with its typical reddish colour, has been subject to fertilisation. the site is surmounted by an ancient homestead of the florio family. the “grotta dei genovesi”, which is located on the island’s western coast, is the main attraction of levanzo. owing to its artistic palaeolithic engravings and neolithic paintings, this cave is to be considered an important geomorphosite (4). another peculiarity of this cave is given by the strange scarcity of stalactite/stalagmite concretions, probably due not only to the scarce rainfall of this island but also to the presence of overlying clayey beds. this cave was formed at the foot of a rock wall made up of monoclinal, seaward-dipping thick beds of mesozoic limestone. these strata show a westward dip-downstream attitude. in proximity of this cave, both on the rock wall overhanging the entrance to the cave and along the underlying coast, the strata crop out extremely well and with considerable regularity. the land journey along levanzo’s western coast is quite difficult but eventually one reaches cala tramontana, which is characterised by a steep calcareous-dolomitic falaise and where a geomorphosite (5) made up of a series of caves named “grotte di cala tramontana” is found. these other caves are all located at nearly the same altitude as the grotta dei genovesi, some 10-20 m above the present sea level (fig. 5). the cala tramontana caves are larger than the more popular grotta dei genovesi and they too contain prehistoric and historic remains. geomorphosite no. 6 is capo grosso, the island’s northern point. this site is particularly interesting because tectonic and erosional processes have shaped it as if it had been cut through, giving origin to a magnificent falaise where thick strata of dolomitic limestone are particularly well exposed. this beautiful outcrop shows west-dipping layers at an angle of about 45°. all the eastern coastline of levanzo is of the falaise type. here, another geomorphosite (7), which is interesting not only from a scenic standpoint, can be admired at capo calcara, where the strata of mesozoic dolomitic limestone were cut by a visible n-s oriented fault which has created this little bay. 2.3 isle of marettimo by sailing from the harbour of marettimo and moving counter-clockwise, it is possible to circumnavigate the whole island and have a good view of the numerous geomorphosites located along the coast. most of these, are coastal caves, whose origin is mainly to be ascribed to the numerous faults which characterise this island (abate et al. 1996). soon after the small beach of bagno di fimmine, the interesting “cave of the camel” (1) appears, whose name is derived from an adjacent rock similar in appearance to the head of this animal. this cave was affected by the collapse of part of its vault, and the sea water inside it is crystal-clear. to the north, one of the most prominent geomorphosites of marettimo is found: the small promontory of “punta troia” (2), well-known for the ancient castle that rises on top of it. this site is also important due to particular geological features, such as the perfect semi-arch which links the promontory to the island, thus creating a particularly striking landscape. behind punta troia, the “cave of thunder” (3) is found, so called after the roar created by the waves that after breaking on the outer wall of the cave, are sucked out through a sort of siphon. adjacent to the cave of thunder, another interesting geomorphosite (4) is found: a gigantic “talus fan”, indeed the largest fan present on the island. this landform stretches from a canyon high on the cliff as far as the sea-shore, with considerable scenic effect. all the island’s north-western coast, with its jagged coastline and spectacular cliffs rising towards the top of mt. falcone (659 m a.s.l.), forms an extremely beautiful and rugged landscape. the “cave of the pipe” (5) is the first to be found. this has a high educational value since, more than any other cave, it clearly shows that the origin of the coastal caves is often due to tectonics. in this case, the cavity was developed along a long, partly collapsed, vertical fault. also “ficarella cave ” (6) was formed at the foot of a long fault: its rock walls also show evident marks of sea breakers at about 5 m a.s.l. shortly afterwards, one arrives at what is considered the most interesting cave, the geomorphosite (7) named “bombarda cave” (fig. 6), near the headland bearing the same name. the cave’s peculiarity is not so much given by the fault stretching across its vault but rather by its geological structure, with thick layers of mesozoic dolomitic limestone in sub-horizontal attitude. practically, the cave shows long, horizontally striated walls, slightly changing in colour. owing to an optical effect the horizontal striae seem to enhance the already considerable depth of this cave. after bassano point – the southernmost tip of the island – and before returning to marettimo, a coastal geomorphosite (8) is found along the regular eastern coast. it consists of one of the very few small beaches of the island, the so-called “praia nacchere”. here, a considerable fault can be observed just at the the main geomorphosites of ... fig. 5 – the steep cala tramontana coastline of the isle of levanzo. it is made up of mesozoic dolomitic limestones and located north of the well-known grotta dei genovesi. the “grotte di cala tramontana” geomorphosite, made up of three main karst caves containing prehistoric finds, is also visible (photo by tamagnini). la ripida costa di cala tramontana, isola di levanzo, composta di calcari dolomitici mesozoici ed ubicata a nord della nota grotta dei genovesi; si nota il gemorfosito “grotte di cala tramontana” dato da tre cavità carsiche principali, anch’esse con reperti preistorici (foto tamagnini). 142 end of the sandy beach. finally, by following a rather demanding trail starting from the village, it is possible to ascend towards geomorphosite (9), which is the island’s highest peak: mt. falcone, rising to an altitude of 686 m a.s.l. 3. conclusions the geomorphosites of the egadi islands are numerous and interesting. they were all formed within two main rock types: i) mesozoic dolomitic limestones, found in the three main islands, and ii) pleistocene bioclastic calcarenites present in favignana. the geomorphosites resulting from carbonate rocks are mainly coastal caves, stacks, pinnacles and talus fans. on the other hand, the geomorphosites formed within calcarenite rocks are both natural – showing considerable examples of cross-bedding and other sedimentation structures – and anthropogenetic, linked to ancient and intense quarrying activities. on the whole, thirty geomorphosites have been identified as examples of major and immediate interest: 14 in favignana, 7 in levanzo and 9 in marettimo. finally it should be noticed that a few years ago the egadi islands were declared a protected marine area (amp) managed at first by the local harbour-office and after by the favignana municipality. however, at present no educational-divulgative material is yet available on the important and interesting geological-geomorphological features of the egadi islands, which should be better understood and appreciated in order to promote sustainable fruition of these natural resources. unfortunately, this is not an isolated situation among the eighteen italian protected marine areas. acknowledgements the author is grateful to professors sandra piacente, from the university of modena and reggio emilia, and francesco torre from the university of trapani, for their critical review of the typescript and useful advice. r. massoli-novelli fig. 6 – la bombarda cave, located along the western coast of marettimo, is characterised by thick layers of mesozoic dolomitic limestones with a sub-horizontal attitude. along the vault, the fault at the origin of the cave is quite evident. a common tectonic origin characterises most of the numerous karst cavities found on this island (photo by massoli-novelli). la grotta bombarda, ubicata lungo la costa occidentale di marettimo, è caratterizzata da bancate di calcari dolomitici mesozoici in giacitura suborizzontale. evidente lungo la volta la faglia all’origine della cavità, una origine tettonica comune alla maggior parte delle numerose cavità carsiche dell’isola (foto massoli-novelli). references abate b., lo cicero g., & renda p. (1982) facies carbonatiche ed evaporitiche del trias superiore di marittimo atti conv. palermo “modelli evolutivi delle zone di cerniera nei sistemi piattaforme carbonatiche-bacini”, rend. soc. geol. it., 5 (1), pp. 71-76. abate b., ferruzza g., incandela a. & renda p. (1995) tettonica trascorrente nelle isole egadi. in: geodinamica e tettonica attiva del sistema tirreno-appennino, camerino, 9-10 febbraio. abate b., bucchieri g., incandela a. & renda p. (1996) le sezioni tirreniane delle località la conca e punta libeccio (isola di marettimo, egadi, sicilia n-o): indagine stratigrafica e paleoecologica boll. soc. geol. it., 115, pp. 145-158. antonioli f., puglisi c., reitano g. & tusa s. (1996) evoluzione geomorfologica pleistocenica del settore costiero di s. vito lo capo (sicilia): rapporti tra neotettonica, eustatismo e comunità preistoriche geosub ‘94, conv. intern. di geologia subacquea, palinuro, 1994, mem. descr. carta geol. it., 52, pp. 337-360. antonioli f., cremona g., immordino f., puglisi c., romagnoli c., silenzi s., valpreda e. & verrubbi v. (2002) new data on the holocenic sea-level rise in nw sicily (central mediterranean sea) global and planetary change, elsevier, 34 (1-2), pp. 121140. colantoni p., lembo p., pantaleone n. a., sacchi l. & spanio f., (1993) morpho-lithological map (1:50.000 scale) of the egadi islands shelf (western sicily) proceedings conf. geological development of the sicilian-tunisian platform, urbino, italy, november 4-6, 1992, unesco reports in marine science, 58, pp. 87-92. d’angelo s., lembo p., marras g., sacchi l. & ventura g. (1996) aspetti geologici ed ambientali dei fondali al largo dell’isola di marittimo geosub ‘94, conv. intern. di geologia subacquea, palinuro, 1994, mem. descr. carta geol. it., 52, pp. 41-52. geremia f. & massoli-novelli r. (2004) il periplo dell’isola di lipari (isole eolie): alla scoperta dei geomorfositi costieri di origine vulcanica (in press). incandela a. (1996) deformazioni neogeniche nelle isole di favignana e levanzo mem. soc. geol. it., 51, pp. 129-135. malatesta a. (1957) terreni, faune e industrie quaternarie nell’arcipelago delle egadi quaternaria, vol. 4, pp. 165-190. massoli-novelli r. (2003) geositi, geoturismo e sviluppo sostenibile conv. naz. sigea “la geologia ambientale: strategie per il nuovo millennio”, in geologia dell’ambiente, 1, sigea, roma. panizza m. & piacente s. (2002) geositi nel paesaggio italiano: ricerca, valutazione e valorizzazione. un progetto di ricerca per una nuova cultura geologica geologia dell’ambiente, 2, sigea, roma. ruggieri g., unti a., unti m. & moroni m.a. (1975) la calcarenite di marsala (pleistocene inferiore) e i terreni contermini boll. soc. geol. it., 94, pp. 1623-1657. torre f. (1980) levanzo la grotta del genovese comune di favignana assessorato regionale beni cultuali e pubblica istruzione. torre f., (1988) notazione a proposito delle oscillazioni del livello del mare nel trapanese durante il pleistocene medio-superiore sicilia archeologica, anno xxiii, no. 74 , trapani. ulzega a. & orru p. (1989) piattaforma continentale delle egadi in: v. agnesi, t. macaluso, a. ulzega, guida alle escursioni, gruppo nazionale geografia fisica e geomorfologia, c.n.r., trapani, 27-30 giugno 1989, università di palermo. 143the main geomorphosites of ... available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 43 48 palaeoecology and taphonomy of the straight-tusked elephant late middle pleistocene site of poggetti vecchi (southern tuscany, italy) chiara capalbo 1,2 , paul p.a. mazza 1 , federico masini 2 , andrea savorelli 1 1 dipartimento di scienze della terra, università di firenze, firenze, italy 2 dipartimento di scienze della terra e del mare (distem), università di palermo, palermo, italy corresponding author: c. capalbo <chiaracapalbo@gmail.com> abstract: works for the construction of thermal pools at poggetti vecchi, near grosseto (tuscany, italy) exposed an accumulation of fossil bones, largely belonging to the straight-tusked elephant palaeoloxodon antiquus, mixed up with stone and wooden tools. the site is radiometrically dated to the late middle pleistocene, and the artefacts were thus created by early neanderthals. palaeobiological and taphonomic analyses of the fauna remains are part of a more general, multiproxy study of the site that provides new information on mis 7-6 transition, as well as on human-animal interactions. keywords: palaeoclimate, palaeoenvironment reconstruction, palaeobiology, taphonomy, elephants 1. introduction poggetti vecchi is an open-air archaeopalaeontological site confined within a narrow valley and located in southern tuscany (central italy), some 5,5 km wnw of roselle and 7 km nw of grosseto (42° 49'8.92" n, 11° 4'19.41" e, fig. 1). the fig. 2 shows the aerial view of the site, from bing map (https:// www.bing.com/maps/?cc=it) with details and annotation concerning the location of the cores s1 and s2 and log a and b. the excavation exposed an about 3 m thick sedimentary succession, deposited in a very narrow bay through alternating phases of accumulation and erosion. all in all, seven lithostratigraphical units, of either terrigenous or carbonate nature, have been recognized (u1u7, fig. 3). vertebrate bones, mixed up with stone tools and wooden multipurpose digging sticks, were discovered mainly in the lower portion of the succession (unit 2). the remains are overlain by thermal carbonates, radiometrically dated to 171 ±3 ka (benvenuti et al., 2017). based on this dating the human artifacts can be assigned to early neanderthals; this sparks interest in the site, especially from a geoarchaeological perspective. the utilization of this multidisciplinary approach at poggetti vecchi provided valuable new insights into the human and animal life in this period of time and in this part of italy where palaeontological and prehistoric discoveries had never been reported before. 2. materials and methods the vertebrate assemblage includes straight-tusked elephant palaeoloxodon antiquus, aurochs, red deer, roe deer, fallow deer, a very advanced transitional speleoid bear ursus deningeri-spelaeus, emys orbicularis, hierophis viridiflavus, and undetermined birds. there are also many small mammals, including watervole arvicola amphibius and several other voles [microtus cf. arvalis, microtus (terricola) ex gr. savii and microtus sp]. most of the bones (a total of 747) were found in unit 2. palaeobiological and taphonomic analyses here presented have been integrated into a geoarchaeological multiproxy study of the site. the relative abundances of the taxa from the different layers were expressed in number of identified specimens (nisp) and minimum number of individual (mni) counts. specimens have been attributed to individuals by side matching, taking into account several characteristics, such as size, relative proportions, the degree of fig. 1 geographical map of southern tuscany showing the https://doi.org/10.26382/aiqua.2018.aiquaconference https://www.bing.com/maps/?cc=it https://www.bing.com/maps/?cc=it ossification, age and state of preservation. to avoid biases induced by different fragmentation potential, the nisp was calculated separately for each of three distinct size classes (<10-100 kg; 100-300 kg; >300 kg). the poggetti vecchi fauna comes from a lacustrine marginal deposit; the susceptibility of the specimens to hydraulic transport and fluvial scattering had to be estimated by adopting vorrhies’ approach (behrensmeyer, 1975; villa & mahieu 1991; voorhies, 1969). bone surface modifications (preand post-depositional) were sought for using conventional analytical approach. the degree of weathering was evaluated following behrensmeyer’s (1978) weathering stages (from stage 0 – non altered to stage 5 – heavily altered). the palaeobiology of the poggetti vecchi mammals (age and sex) have been assessed based on different proxies. ontogenetic ages were calculated from the degree of ossification and epiphyseal fusions (roth, 1984; kangwana, 1996; lister, 1999; reitz & wing 2010; speth, 2000; herridge, 2010), as well as from tooth eruption and wear (laws, 1966; krumrey & buss 1968; brown & chapman 1991; haynes, 1991; hillson, 2005; rasmussen et al., 2005). some of poggetti vecchi’s mammal remains have been tentatively sexed, aiming at assessing the relative frequencies of males and females. palombo & villa (2003) was followed to sex the remains of palaeoloxodon antiquus. 3. results the macromammal assemblage from unit 2 is dominated by very large herbivores: the straight-tusked elephant palaeoloxodon antiquus and the aurochs bos primigenius (39.9% and 19.4% of the largest species, respectively). based on the developmental stages of different skeletal remains (skull, mandible, molar, and tusk) from unit 2, palaeoloxodon antiquus is represented by a total of 7 individuals: three juveniles of 1-8 years, one 14-15-year-old sub-adult, two 20-30-year-old adults, and one individual older than 40 years. the skulls are crushed into splinters; a fairly complete, but poorly preserved, tusk (n.162) belongs to one of the prime adult individuals. based on the criteria proposed by palombo & villa (2003) and lister (1996), the assem 44 fig. 2 aerial view of the site with the location of cores s1 and s2 and logs a and b as reported in fig. 3. (the figure was drawn from benvenuti et al., 2017). capalbo c. et al. 45 blage from poggetti vecchi’s unit 2 includes elements of both males (i.e., the right pyramidal 987 has the articular surface for the unciform largely overlapping the hooked process; the right uncinate 295 bears an elongated and straight joint surface for metacarpal v) and females (i.e., the right coxal bone 5245 with the wing of the ileum shaped like that of female individuals of mammuthus). the bones retrieved from the dark clay sediments of unit 2 had subhorizontal orientation, and were concentrated in a ne-sw-trending strip. they were found juxtaposed with little or no sediment in between. the general state of preservation of the bones is good; almost all, however, are broken and have severely scratched surfaces (37,2%). the relative skeletal frequencies of the site’s best-represented species, i.e., palaeoloxodon antiquus and bos primigenius, gave revealing results. the vertebrae, ribs, basipodial bones, and phalanges of p. antiquus are unexpectedly underrepresented whereas the opposite occurs for b. primigenius (fig. 3). due to their high fragmentation, ribs are generally overestimated in the nisp counts. the analysis of the collection of remains of palaeoloxodon antiquus reveals that easily winnowed bones of the voorhies groups i (i.e., ribs and vertebrae) and i & ii (i.e., phalanges) are under-represented; in contrast, the modestly transportable ones, belonging to voorhies group ii (i.e., humerus, radius, pelvis, femur, tibia, metapodial) and the lag elements of voorhies group iii (i.e., skull, mandible), are quite more numerous. moreover, the elephant bones show relatively low incidence of abrasion/polishing (18.63%). conversely, bos primigenius, cervus elaphus and capreolus capreolus are largely represented by bones that are susceptible to hydraulic transport and most of them are polished and show evidence of abrasion. based on nisp counts, virtually all the hardparts are broken (95%). most (23%) were fractured in dry state and only 6% in fresh state; spiral fractures are rare (3,7%). very few bones (2.5%) have undergone modest weathering (1.7% are in weathering stage 1, and 0.7% in weathering stage 1/2-2: behrensmeyer 1978). root etching (1.9%) was observed on the bone surfaces and, sometimes, also on the fractures. humic corrosion evifig. 3 correlation of stratigraphical data along the cross section showed in fig. 2. (the figure was drawn from benvenuti et al., 2017). men and elephants in prehistoric maremma dence is very low (1.1%). a few bones (5%) show evidence of scavenging. the size of the scoring marks, pits and bites are suggestive of a predator or scavenger with blunt pointed teeth. the occurrence of rare hyena coprolites and of an erratic left second lower premolar of the spotted hyena crocuta crocuta attest to the presence of these carnivores at the site. finally, only three specimens show evidence of human-derived modification: the lateral portion of the diaphysis of a left humerus of bos primigenius, the basal portion of a shed right antler and a fragmental diaphysis of a tibia of cervus elaphus. both humerus and tibia are very polished. 4. discussion and conclusion the radiometric datings from unit 4 locates the whole section at a time period between late mis 7 and late mis 6. the geological and palaeobiological reconstructions of the site are detailed in benvenuti et al. (2017). the evidence accumulated by this multiand interdisciplinary teamwork unraveled the succession of events that occurred during the deposition of the poggetti vecchi sedimentary succession (units 1-6). four different flooding events were detected, separated by regressions. during the flooding episodes, homogeneous organic muds deposited in this shallow, protected lacustrine setting; in contrast, vertebrate remains and human artifacts accumulated on the erosive surfaces that formed during the regressions. the fossil records tell us that at the time when the fossiliferous site was formed, the area was dominated by extensive open grassland inhabited by large herbivores, among which palaeoloxodon antiquus and bos primigenius, whereas the red and roe deer probably browsed in sparse groves. this outline is confirmed by the abundant herbaceous plant pollen, especially of poaceae, which dominates the spectra along all the stratigraphy. the abundant frequency of freshwater fens, together with the high variety of wetland plants and rich mollusk and ostracod assemblages recorded along the whole sedimentary succession, confirm periodic fluctuations of groundwater seeps and freshwater bodies. in particular, palaeooecological insights indicate that the unit 2 fauna was well-tuned with the climatic and environmental fluctuations that occurred within the short time period between the onset of mis 6 (lake lowstand and subaerial erosion at the transition from unit 1 to unit 2) and the next interstadial (lake highstand phase and deposition of sedimentary units 3-4). the palaeobiological inferences from the small and large mammal assemblages are coherent with the succession of palaeoenvironmental signals and sedimentary events and their tuning with the main climatic fluctuations. poggetti vecchi differs from other similar sites in many respects (e.g. stratigraphical age, number of elephants involved, kind of artifacts). the lack of palaeobiological and taphonomic evidence for active hunting suggests that the elephants probably died from some natural, catastrophic event. the presence of females and males of a wide age spectrum and the bone-to-bone contact (with virtually no sediment in between) of their remains suggest that the elephants were components of a family group, which likely died altogether at the same time. a plausible scenario to account for these simultaneous deaths could be a very intense cold snap, beyond the elephants’ thermal tolerance limits and too sudden to flee from. based on these insights, it can be speculated that the narrow valley of poggetti vecchi, with its geothermal hot springs, offered a shelter to the elephant clan during a particularly cold season during the transitional mis 7-6 time span. it can be speculated that by being forced to stay near the only heat source, they consumed all the vegetation in the surrounding area and finally died of starvation. the accumulated evidence indicates that the carcasses lied largely unexposed and inaccessible to predators, presumably at least partially immersed in water. decomposition then progressed in the conservative environment until complete skeletonization. after this, the skeletons were disarticulated, and the bones scattered nearby, presumably by occasional (seasonal) streams of water. palaeobiological and taphonomical data suggest the death of elephants cannot be associated with active hunting, although elephants were butchered soon after their death. the high amount of stone and wooden implements that were found closely interspersed among the bones, all over the area, is an indisputable sign of animal human interaction. hence it likely suggests that 46 fig. 4 frequencies of skeletal parts (observed versus mni-based expected amounts of bones). a) palaeoloxodon antiquus; b) bos primigenius. in a) we notice a marked under-representation of axial bones, basipodial bones and phalanges. a b capalbo c. et al. humans managed to access the great amount of flesh that the lucky circumstances made available. the wear patterns on the edges of stone tools indicate butchering actions on soft animal tissues, but also the scraping or shaving of wood, which suggests that the wooden rods were probably at least partially manufactured directly at the site. it is also likely that humans removed only small amounts of flesh, without reaching the bones with the tools they used for processing the carcasses. the scattering of the bones in a fairly small area, the total lack of anatomical articulation and the virtual absence of specific kinds of bones, such as vertebrae, basipodial and metapodial bones, and phalanges underscore an apparent skeletal selection. whether this occurred before or after the skeletonization and dismembering of the carcasses is yet unclear. the behavior of extant african hunters (crader, 1983; fisher, 1992) may provide insights into the possible patterns of processing and preferential selection of the elephant carcass parts at poggetti vecchi. in general, the proximal parts of the limb bones (humeri and femora) and the extremities (carpals, tarsals and phalanges) are removed from the carcasses and transported to the villages, where the flesh can be stripped off more accurately and the marrow extracted if necessary. a similar behavior could explain the underrepresentation of basipodial and metapodial bones and phalanges in the poggetti vecchi elephant samples. nonetheless, the voorhies (1969) categories of bones represented at the site indicate that the winnowing action of streaming water could also well explain the very low frequencies of easily transportable elements. at the same time, streaming water may account for the occurrence of the remains of other taxa (bos, cervus, capreolus): these bones, which are quite susceptible to hydraulic transport, are largely abraded or polished. they were therefore likely reworked from uphill areas and are allochthonous for the site. the extensive scratching of the bone and tusk surfaces, as well as by the dominance of dry bone breakage is highly suggestive that the skeletons were trampled over, perhaps repeatedly, by bypassing animals, elephants included. hence, trampling and kicking can account for their disarticulation and scattering, at a time when the bones were already in dry state. finally, the root etching and humic corrosion on many bones are probably associated with plant colonization. poggetti vecchi offers the chance to obtain an unprecedented amount of information on how local early neanderthals interacted with the animals of the time, as well as on how skillfully flexible they were in response to contingencies under the challenging environmental and climatic conditions at the mis 7-6 transition. based on the collected evidence, local human hunters benefited from the large accessibility to concentrated resources unexpectedly made available by the fortunate interplay of palaeobiological, geological and climatic factors. the site thus offers critical information on the behavior of early neanderthals, which is still very imperfectly known. contrary to previous belief, early neanderthals appear to have been particularly skilled to deal opportunistically with environmental and climatic adversities, and able to modify over time the scheduling of their exploiting strategies. acknowledgements the study was financially supported by mazza p. fondo ateneo 2015 miur (the italian ministry of education, university and research). we are grateful to all colleagues and experts involved in the geoarchaeological study of poggetti vecchi site. references behrensmeyer a.k. (1975) the taphonomy and paleoecology of plio-pleistocene vertebrate assemblages east of lake rudolf, kenya. bulletin of the museum of comparative zoology, 146, 473-578. behrensmeyer a.k. (1978) taphonomic and ecological information from bone weathering. paleobiology, 4, 150-162. benvenuti m., bahain j. j., capalbo c., capretti c., ciani f., d’amico c., esu d., giachi g., giuliani c., gliozzi e., lazzeri s., macchioni n., mariotti lippi m., masini f., mazza p.p.a., pallecchi p., revedin a., savorelli a., spadi m., sozzi l., vietti a., voltaggio m., aranguren b. (2017) paleoenvironmental context of the early neanderthals of poggetti vecchi for the late middle pleistocene of central italy. quaternary research, 88(2), 327344. brown w.a.b., chapman n.g. (1990) the dentition of red deer (cervus elaphus): a scoring scheme to assess age from wear of the permanent molariform teeth. journal of zoology, 224, 519-36. crader d.c. (1983) recent single-carcass bone scatters and the problem of “butchery” sites in the archaeological record. in: clutton-brock j., grigson c. (eds.) animals and archaeology, hunters and their prey. bar international series 163, vol. 1, oxford. fisher jr. j.w. (1992) -observations on the late pleistocene bone assemblage from the lamb spring site, colorado. in: stanford d.j., day j.s. (eds.) ice age hunters of the rockies. denver museum of natural history and university press of colorado, niwot (co), 51-81. haynes g. (1991) mammoths, mastodonts, and elephants: biology, behavior, and the fossil record. cambridge university press, cambridge, pp. 413. herridge v.l. (2010) dwarf elephants on mediterranean islands: a natural experiment in parallel 531 evolution. phd thesis, university college london. http://discovery.ucl.ac.uk/133456/. hillson s. (2005) teeth. cambridge university press. kangwana k. (1996) studying elephants. in: awf technical handbook series, vol. 7. african wildlife foundation, nairobi, kenya, pp. 178. krumrey w.a., buss i.o. (1968) age estimation, growth, and relationships between body dimensions of the female african elephant. journal of mammalogy, 49(1), 22-31. laws r.m. (1966) age criteria for the african elephant, loxodonta a. africana. east african wildlife journal 47 men and elephants in prehistoric maremma http://discovery.ucl.ac.uk/133456/ 4, 1-37. lister a.m. (1996) sexual dimorphism in the mammoth pelvis: an aid to gender determination. in: shoshani j. & tassy p. (eds.) the proboscidea. oxford university press, oxford, 254-259. lister a.m. (1999) epiphyseal fusion and postcranial age determination in the woolly mammoth, mammuthus primigenius (blum.). deinsea 6, 79-88. (25). deinsea, annual of the natural history museum rotterdam, 6, 79 88. palombo m.r., villa p. (2003) sexually dimorphic characters of elephas (palaeoloxodon) antiquus from grotte santo stefano (viterbo, central italy). in reumer j.w.f., devos j., mol d. (eds.), advances in mammoth research. proceedings of the second international mammoths conference, rotterdam, may 16-20, 1999. deinsea 9, 293 315. rasmussen h. b., wittemyer g., douglas‐hamilton i. (2005) estimating age of immobilized elephants from teeth impressions using dental silicon. african journal of ecology, 43(3), 215-219. reitz e., wing e. (2010) zooarchaeology (third edition), cambridge, cambridge university press. roth v. l. (1984) how elephants grow: heterochrony and the calibration of developmental stages in some living and fossil species. journal of vertebrate paleontology, 4, 1, 126-145. speth j.d. (2000) boiling vs baking and roasting: a taphonomic approach to the recognition of cooking techniques in small mammals. in: rowley-conwy, p. (ed.), animal bones, human societies. oxbow books, oxford, 89-105. villa p., mahieu e. (1991) breakage patterns of human long bones. journal of human evolution 21, 27-48. voorhies m. (1969) taphonomy and population dynamics of an early pliocene vertebrate fauna, knox country, nebraska. university of wyoming contributions to geology special paper no. 1, larmie. 48 ms. received: may 15, 2018 final text received: may 27, 2018 capalbo c. et al. imp.d'argenio la “geologia stratigrafica” di azzaroli e cita a 45 anni dalla sua pubblicazione bruno d'argenio dipartimento di scienze della terra, università di napoli federco ii; l.go s. marcellino 10, 80138 na iamc istituto per l'ambiente marino costiero del cnr calata porta di massa, 80133 na abstract: b. d’argenio, stratigraphic geology by a. azzaroli and m. b. cita, 45 years later. a concise review of a textbook of stratigraphy that was very influential in italy during the late sixties and seventies of the last century; a relevant historical moment of paradigmatic and scientific changes within the international geologic community. parole chiave: stratigrafia, italia, commissione italiana di stratigrafia. keywords: stratigraphy, italy, italian stratigraphy commission. il quaternario italian journal of quaternary sciences 21(1a), 2008 9-10 quando, alcuni mesi or sono, ho scelto questo titolo per commentare, dopo 45 anni, un evento poco valorizzato: la pubblicazione del primo libro di testo moderno di stratigrafia in italia, non mi ero reso conto che non sarebbe stato semplice parlarne adeguatamente nei pochi minuti a mia disposizione. sarò perciò molto schematico, e certo non esauriente, in queste considerazioni. penso che pochi dei presenti erano già attivi nella ricerca nei primi anni 60 dello scorso secolo, per cui mi sembra opportuno iniziare con qualche considerazione sulle conoscenze stratigrafiche di quegli anni. voglio innanzitutto sottolineare la importanza che il testo di augusto azzaroli e maria bianca cita ha avuto in italia non solo per gli studenti (cui formalmente era dedicato) ma anche per quei giovani ricercatori come me che, a quel tempo, avevano ben pochi riferimenti “moderni” in italiano (se si eccettua forse la terra di trevisan e tongiorgi del 1958 in cui peraltro alla stratigrafia formale si faceva appena cenno). tutto ciò soprattutto per gli esempi usati che, salvo per alcuni intervalli (ad es. il quaternario) e per alcune aree (ad es. le alpi meridionali), ci imponevano di destreggiarci tra i classici testi francesi (la geologie stratigraphique di maurice gignoux in primis), alquanto generici nei formalismi propri della stratigrafia codificata, e quelli di lingua inglese, più ricchi di regole anche empiriche, ma privi di riferimenti nostrani (ad es. l'ottimo stratigraphy and sedimentation di w.c. krumbein e l.l. sloss, 1963, ii ed.). c'è quindi un merito “storico” in questo testo: quello di aver proposto un quadro di riferimento sia normativo che esemplificativo adatto alle esigenze italiane degli anni 60. personalmente posso ricordare quanto i primi due volumi della geologia stratigrafica mi furono di aiuto allorché ebbi modo di spendere un anno a princeton tra il 1965 e il 1966. qui, potei seguire un piacevolissimo quanto poco accademico corso di geologia stratigrafica svolto da hollis hedberg: uno dei padri fondatori della stratigrafia formale moderna. un corso tenuto a casa sua, di sera, con birra e patatine fritte e una collezione impressionante di testi, carte geologiche ed estratti originali degli ultimi 200 anni. qui l'aver letto il testo di azzaroli e cita, mi consentì di partecipare con successo ad un processo di acculturamento che era anche una sorta di gara, in cui ciascuno aveva assegnato (o si sceglieva) un argomento su cui di volta in volta riferire, distribuendo poi a tutti un testo che veniva letto, commentato ed emendato seduta stante, consentendo a tutti, dopo una quindicina di incontri, di avere un volume ciclostilato “collettivo”, ricco di definizioni, schemi e figure. ma torniamo alla geologia stratigrafica di azzaroli e cita. i tre volumi (i primi due del 1963 e il terzo del 1967) per un totale di oltre 1000 pagine, contengono una introduzione generale ai “principi di stratigrafia” e una parte “storica” (dal pre cambiano al quaternario) che occupa oltre metà del primo volume e gli interi altri due volumi. mi soffermerò particolarmente sul primo volume giacché contiene la parte più innovativa in cui si presentano le idee moderne per il tempo: gli ambienti di sedimentazione, le variazioni relative de livello del mare e i rapporti tra sedimentazione e tettonica. vi si colgono concetti ispirati ad autori come petti john o twenofel: una discontinuità rispetto ai testi italiani, ma anche a quelli in lingua francese del tempo. mancano purtroppo i riferimenti bibliografici e ciò è forse il limite maggiore alla utilizzazione dei concetti espressi anche attraverso una integrazione con le fonti originali. ciò vale anche per la cronologia numerica in cui si fa riferimento non solo ai metodi basati sul decadimento radioattivo ma anche a quelli di tipo astronomico, con cenni ai calcoli di milankovic (sia pure con una punta di scetticismo). 10 b. d’argenio nel capitolo dedicato agli ambienti di sedimentazione la trattazione è di tipo tradizionale, anche se viene presentata qualche idea moderna, ricordando la dinamica delle “scogliere” così come vista da henson: concetti che apriranno la strada alla stratigrafia sequenziale del decennio successivo. anche la discussione delle variazioni relative del livello marino (“trasgressioni e regressioni”) è ben impostata. manca però ogni cenno all'eustatismo che al tempo non era ancora “di moda”. infine nel capitolo dedicato ai rapporti tra sedimentazione e tettonica si fa ancora riferimento alle geosinclinali, ma è interessante notare diverse note critiche alle generalizzazioni, allora molto di moda, di jean aubouin. classico infine è l'approccio alla stratigrafia formale con chiare distinzioni tra le varie categorie di unità stratigrafiche e una buona discussione sulla problematica degli stratotipi. molto interessante é il riferimento al codice di nomenclatura stratigrafica americano del 1961, che servirà poi di base alle sue versioni successive. ugualmente ampio e approfondito è il capitolo dedicato alle correlazioni stratigrafiche, una delle tematiche che andrà sempre più evolvendo verso l'approccio quantitativo (biostratigrafico o strumentale che sia). mi fermo qui nel commentare questa prima parte del primo volume. i capitoli successivi e quelli degli altri due volumi sono ugualmente pregevoli per la quantità degli esempi italiani utilizzati (anche qui va rammentata l'assenza di riferimenti bibliografici che avrebbe dato ai questi esempi una valenza certamente maggiore). concludo ricordando ancora una volta i primi anni '60, tempi nei quali cominciava una “rivoluzione culturale” nelle scienze della terra, la più importante dai tempi di lyell e darwin, e a circa un secolo da quella, col ritorno ad una concezione unificante della geologia, anche se ispirata ad un pervasivo mobilismo. per la verità va ricordato che nella stratigrafia, intesa nel senso ampio di analisi e correlazione delle successioni di eventi, questi effetti si sono fatti sentire solo negli anni '70, con la utilizzazione rutinaria di concetti come eustatismo e ciclicità di elevata frequenza e l'impiego di metodologie analitico-strumentali “globali”, quali la geochimica isotopica o il palemagnetismo. ci si potrebbe chiedere se questo rapido processo di cambiamento di paradigmi abbia avuto conseguenze rilevanti anche in quella parte della stratigrafia formale che è oggetto delle discussioni di oggi e domani. ed è a questa domanda, credo, che dobbiamo dare una risposta. perché se è vero che nella nomenclatura stratigrafica valgono quei principi generali (correttezza formale, accessibilità dei controlli e salvaguarda delle priorità) che sono validi nella tassonomia botanica, zoologica e paleontologica (pur con le relative specificità), è anche vero che le moderne metodologie analitiche consentono di esercitare controlli che quarant'anni or sono erano appena nel loro stato nascente (si pensi solo ai già ricordati paleomagnetismo e geochimica isotopica). in questo contesto di rapidi avanzamenti metodologici si rischia di dimenticare che vi sono aspetti relativi agli oggetti analizzati: i corpi geologici, e i loro rapporti e i loro fossili, che furono nel tempo, stabiliti da madre natura e risultano pertanto “immodificabili” come ci insegnano le norme della stratigrafia formale. ciò giustifica la necessità impellente, oggi, di avere una commissione italiana di stratigrafia autorevole e fattiva. maria bianca cita, e in piccola parte io stesso, abbiamo cercato di riproporre, con l'aiuto degli altri colleghi della cis, una commissione attiva e vigile, ma é chiaro che senza il contributo convinto della comunità scientifica italiana queste finalità non potranno essere realizzate, anche perché è necessario che altri tra voi prendano il nostro posto per consentire di mantenere l'alto livello scientifico degli scorsi decenni che ha dato al nostro paese una posizione di rilievo nella comunità stratigrafica internazionale. ms. ricevuto il 2 aprile 2008 testo definitivo ricevuto il 17 aprile 2008 ms. received: april 2, 2008 final text received: april 17, 2008 imp. stefanelli ttaapphhoonnoommiicc eeffffeeccttss oonn tthhee ppaalleeooeeccoollooggiiccaall rreeccoorrdd ooff tthhee lloowweerr pplleeiissttoocceennee sshhaallllooww bbeenntthhiicc ffoorraammiinniiffeerraa aasssseemmbbllaaggeess ((wweesstteerrnn eemmiilliiaa,, iittaallyy)) ssiimmoonnaa sstteeffaanneellllii dipartimento di geologia e geofisica, università degli studi di bari, via orabona n° 4, 70125 bari; email: stefanelli@geo.uniba.it. abstract: stefanelli s.,taphonomic effects on the paleoecological record of the lower pleistocene shallow benthic foraminifera assemblages (western italy). (it issn 0394 – 3356, 2004). taphonomic and paleoecological quantitative analyses are drawn from benthic foraminiferal assemblages from four lower pleistocene marine sections (western emilia). then, the data are used to perform the cluster analysis (by means spps program) in order to group samples and benthic foraminifera on the basis of their taphonomic and paleoecological similarities. the sections are arranged in meter to tens-of-meters thick sedimentary cycles. the lower part of each cycle represents the sedimentological transport of shelly material from shallow sandy bottoms to slightly deeper settings (20-40m depth range) due to catastrophic flooding events. the upper part of the cycles represents the return to normal, muddy deposition in an inner shelf setting. for the taphonomic analysis, foraminifera specimens are classified into taphonomic categories on the basis of their state of preservation: (1) fresh tests, (2) opaque tests, (3) light orange to dark brown iron-stained tests, (4) black or black-striped tests filled with or replaced by pyrite (including partial dissolution of the tests), (5) breakage of the tests. in both the lithological intervals of the cycles, the high number of specimens grouped into “breakage tests” category leads to suppose the destruction of the tests as the principal taphonomic process affecting the foraminiferal assemblages. in the mudstone partings of the sandstone interval, the mechanism that caused the destruction of the tests is the transport in a shallow-high hydrodynamic setting where benthic foraminifera are put into suspension in water and collide each other and/or with sediment grains. in the same interval, paleoecological results points out that the specimens grouped into “fresh tests” category belong to displaced taxa coming from shallow sediments due to the transport. as a consequence, a correct paleoecological interpretation from the assemblages of the lower part of the cycles is not possible. in the high-bioturbated mudstones, the “breakage tests” category consists in fragments of hyaline specimens. in these lithological intervals of the cycles, the destruction of the tests may well be due to a strong dissolution activity that causes, in the typical dissolution sequence of pore-boaring species, the corrosion and amplification of the pores and, then, the destruction of the chambers. though the taphonomic activity, a paleoecological interpretation is possible. it reconstructs a sedimentary deposition in a shallow-quite environment and changes in oxygen bottom-water content. riassunto: stefanelli s., effetti tafonomici sul significato paleoecologico delle associazioni a foraminiferi bentonici di mare basso del pleistocene inferiore (emilia occidentale, italia). (it issn 0394 – 3356, 2004). due analisi quantitative, una tafonomica e una paleoecologica, sono state condotte su associazioni a foraminiferi bentonici di quattro sezioni marine. i dati ottenuti sono stati successivamente utilizzati per effettuare l’ analisi cluster (mediante programma spss) per raggruppare i campioni ed i foraminiferi sulla base delle loro analogie tafonomiche e paleoecologiche. le sezioni in esame, affioranti nella parte occidentale dell’emilia romagna, si sono depositate nel pleistocene inferiore e consistono in cicli sedimentari di alcune decine di metri di spessore. la parte inferiore di ciascun ciclo (sabbiosa) rappresenta il trasporto di materiale conchigliare proveniente da aree superficiali e depositatosi in aree profonde (20-40 metri di profondità), in seguito a piene fluviali. la parte sommitale di ciascun ciclo (argillosa) rappresenta, invece, la deposizione di sedimenti in regime marino di maggiore tranquillità. per l’analisi tafonomica, i foraminiferi sono stati raggruppati in categorie sulla base dello stato di preservazione dei gusci: 1) gusci intatti, 2) gusci opachi, 3) gusci ossidati, 4) gusci piritizzati (inclusa la parziale dissoluzione del guscio), 5) gusci rotti. in entrambi gli intervalli litologici dei cicli, la categoria “gusci rotti” raggruppa un numero alto di individui suggerendo, così, la distruzione dei gusci come il principale processo tafonomico che ha interessato le associazioni a foraminiferi. nella porzione basale dei cicli, la distruzione dei gusci è causata dal trasporto in un ambiente poco profondo e di alta energia. in un simile ambiente, i foraminiferi, portati in sospensione e urtandosi l’uno con l’altro e/o con le particelle di sedimento, si distruggono. nello stesso intervallo, l’analisi paleoecologica ha evidenziato che le specie raggruppate nella categoria “gusci intatti” appartengono a foraminiferi alloctoni, trasportati da un ambiente più superficiale a causa di eventi di trasporto. di conseguenza, per questi intervalli, una corretta interpretazione paleoecologica sulla base delle associazioni esaminate non è stata possibile. negli intervalli sommatali e bioturbati dei cicli, la categoria “gusci rotti” raggruppa frammenti di gusci di forme ialine. si ipotizza, quindi, che la distruzione dei gusci possa essere causata da un forte processo di dissoluzione. nella tipica sequenza, la dissoluzione dei gusci porosi comporta la graduale corrosione e allargamento dei pori ed, infine, la rottura delle camere. per questi intervalli l’analisi paleoecologica ha ricostruito un ambiente di deposizione tranquillo e superficiale, nel quale ci sono state variazione del contenuto di ossigeno al fondo. keywords: benthic foraminifera, early pleistocene, taphonomy, paleoecology parole chiave: :oraminiferi bentonici, pleistocene inferiore, tafonomia, paleoecologia il quaternario italian journal of quaternary sciences 1177(1), 2004, 63-74 11.. iinnttrroodduuccttiioonn benthic foraminifera represent an important tool in ecological research. a vast literature established the existence of a strong relationship between the distribution of these organisms and oceanographic properties (phleger, 1960; chierici, busi & cita, 1962; blancvernet, 1969; corliss, 1985; caralp, 1989; hermelin & shimmield, 1990; murray, 1991; barmawidjaja et al., 1992; jorissen et al., 1992). changes in their faunal 64 s. stefanelli composition are dependent on the responsiveness of each particular species, whose presence can be attributed to changes in environmental factors such as dissolved oxygen, nutrient input, water temperature and salinity, and bathymetry. hence, analyses on the composition of benthic foraminiferal assemblages provide information about the properties of the ocean bottom-waters and their variations through time. the modern-day distribution of benthic species is widely used to reconstruct the environmental conditions recorded by the fossil assemblages. murray (1991) argued that the better paleoecological interpretations are extrapolated from the “ideal dead assemblage” that reflects, with fidelity, the living assemblage. however, the dead/fossil assemblage represents many generations accumulated over a long period of time (time averaging, staff et al., 1996). furthermore, through the time, because of the relatively small size of benthic foraminifera, the dead assemblage is, potentially, very susceptible to post-mortem processes, i. e. transport and destruction of the tests, abrasion, dissolution and bioerosion (murray & alve, 1999, martin, 1999). consequently, a fossil assemblage can be relatively modified with respect to a living fauna and important information can be lost, and this may have negative implications in the paleoecological interpretation of the fossil assemblages. hence, it is important to know the manner in which the fossils are preserved, i. e. taphonomy. the type of fossil preservation can, in fact, provide important insights and contribute to a better understanding of past ecology. the present work represents a small contribution to the preservation history of the benthic foraminiferal fauna. still little, in fact, exists on the taphonomy of fossil foraminifera (murray, 1973; 1976a; 1983; douglas et al., 1980; loubere & gary, 1990; murray & alve, 1999; walker & goldstein, 1999; barbieri, 2001) and probably less is known about the rate of taphonomical alteration suffered by tests in modern settings. a quantitative taphonomical analysis is attempted on the benthic foraminiferal assemblages from four lower pleistocene marine sequences. the aim is to compare the taphonomic data with the paleoecological results and to verify to what degree the taphonomic history obliterated the paleoecological signal. moreover, since taphonomic and paleoecological results drawn from the mollusk assemblages are also available, a further purpose is to compare the response of such different tassonomic groups to taphonomic effects and paleoenvironmental changes. 22.. ggeeoollooggiiccaall aanndd ssttrraattiiggrraapphhiiccaall sseett-ttiinngg the lower pleistocene studied sequences outcrop in western emilia, along the external apennine margin and form part of the infill of the po plain-adriatic foredeep (fig. 1a). the northern adriatic is a collisional basin, characterized by active thrusting during the deposition, in which several basin-wide and unconformitybounded sedimentary cycles have been recognized (ricci lucchi et al., 1982; pieri, 1983; ricci lucchi, 1986). sedimentologic data suggest that the lower pleistocene cycles were formed by changes in clastic input, controlled by tectonics and the climate (mutti, 1996; molinari, 1997). in the early pleistocene, a phase of tectonic uplift increased the slope of the nearby mountain front and the sediment availabil i ty. simultaneously, the local climate conditions in the form of heavy rain fall triggered hyperpycnal flows and turbidite currents that caused the delivery of large amounts of sands that deposited in the shallow shelf. this hypothesis is substantiated by data from the modern mediterranean, where turbidity currents generated during river floods are recognized as important means of sediment delivery from the continent, across the shelf, and down to abyssal regions (mulder et al., 2001). conversely, during times of widespread forestal cover of the nearby mountain fronts, in meteorological conditions similar to present ones, the mud deposition prevailed (dominici, 2001). the four lower pleistocene studied sections outcrop along the flanks of the arda river (castell’arquato piacenza area) and the stirone river (salsomaggiore parma area), the enza river (s. polo – reggio area), and the tiepido river (castelnovo modena area). the sequences are arranged in meter to tens-of-meters thick sedimentary cycles (fig. 1b). the lowest part of each cycle is formed by stratified fine and coarse bioclastic sandstones intercalated with thin mudstone beds and flasers, followed upward by thoroughly bioturbated mudstones. taphonomical data (dominici, 2001) based on macrofaunal assemblages from the sandstone intervals are suggestive of the sedimentological transport of shelly material from shallow sandy bottoms (a 0-35m depth range is proposed on the basis of modern occurrences of the characterizing taxa), to slightly deeper settings (20-40m depth range), where these remains got mixed with local bivalves from dysaerobic bottoms. in this context, the upper mudstone part of each cycle represents the return to normal deposition in an inner-shelf setting. the near-monospecific assemblages dominated by arctica islandica from the sandstone intervals are interpreted as diagnostic of dysaerobic condit ions. conversely, assemblages from the mudstone intervals, with a more diverse fauna dominated by venus multilamella, show normal aerobic conditions. 33.. mmaatteerriiaall aanndd mmeetthhooddss ooff aannaallyyssiiss for the benthic foraminiferal study, a total of thirtynine samples were analyzed (see again fig. 1b). the samples were collected in the mudstone beds intercalated in the sandstone intervals and in the bioturbated mudstones forming the upper part of each cycle. for each sample 300 gr. were washed over a set of sieves with mesh widths of 500, 250, 125 and 63 µm. at least 300 individuals were counted. the benthic foraminifera counted belong to the species commonly distributed in the mediterranean basin in the infralitoral zone (0-40m: sgarrella & moncharmont zei, 1993), in accordance with the paleodepth determined through macrofaunal data (dominici, 2001). in appendix a the list of the taxa encountered in this study is shown. for the taphonomic quantitative analysis, the entire washed residue > 125 µm and < 500 µm was examined in its benthic foraminifera content. the specimens were classified in the following taphonomic categories of wang & chappell (2001), slightly modified for this study. these categories are: (1) fresh tests, (2) opaque tests, (3) light orange to dark brown iron-stained tests (including partially corroded tests), (4) black or black-striped tests filled with or replaced by pyrite (including partial dissolution of the tests). to these, another two categories have been added: (5) breakage of the tests (murray & alve, 1999) and (6) pitting (boltovskoy & wright, 1976). ). finally, the percentages of frequency were calculated. for the paleoecological quantitative analysis, the fraction 125-250 µm was examined in its benthic foraminifera content and the percentages of frequency calculated. then, hierarchical cluster analysis, a statistical approach particularly indicated in presence of heteroge65taphonomic effects on ... neous data set, was performed. those taxa with a frequency of more than 2% as well as those of particular environmental significance were selected for this analysis. finally, a raw data matrix, made up of 39 samples (rows) x 19 taxa (columns), was used. hierarchical cluster analysis was performed on the relative percentage of frequencies per sample by means of spss program, version 9.0. the hierarchical clustering routine produces a dendrogram, a two-dimensional plot that shows how the data points (frequencies of taxa) can be clustered. for this work, the q-mode and r-mode clustering were performed. the q-mode clustering obtains a dendrogram that allows the recognition of samples with similar faunal compositions. in the taphonomic analysis the r-mode clustering constructs a dendrogram that allows the grouping of the fig. 1 location of the studied area and stratigraphic correlation of the small-scale sedimentary cycles detected in the four sections. localizzazione dell’area studiata e correlazione stratigrafica dei cicli sedimentari a piccola scala riconosciuti nelle quattro sezioni. 66 taphonomic categories. in the paleoecological analysis the r-mode clustering groups foraminifera with a similar ecological meaning. the most significant dendrograms were obtained using the average-linkage between group, pearson correlation. 44.. rreessuullttss 44..11 ttaapphhoonnoommiicc aannaallyyssiiss in the q-mode dendrogram, the samples are grouped into two big clusters, named cluster i and cluster ii (fig. 2). in the r-mode dendrogram, the taphonomic categories of pitting, dissolution and breakage form one cluster. the other categories are treated as poorly correlated variables and the lower degree of correlation is shown by the fresh tests. cluster i groups together samples that present the highest percentages of fresh tests, most of which come from the sandstone intervals. within this cluster, the subclusters 1a and 1c include samples with the highest values of “breakage” and “pyritization”, up to 40%. common, also, are the light orange to dark brown ironstained tests. moreover, in subcluster 1a the samples show slightly higher percentages of opaque tests. cluster ii groups, above all, samples from the mudstone intervals. within this cluster the subcluster 2a consists of samples that have a high percentage of light orange to dark brown iron-stained tests, all from the enza section. the subcluster 2b groups samples with pyritized, pitted and broken tests. finally, subcluster 2c groups together samples characterized by opaque tests. regarding the traces of oxidation and pyritization, substantial differences emerge between the tests grouped in cluster i (sandstones) and the tests grouped in cluster ii (mudstones). in the mudstones, the tests present an internal pyrite replacement evidenced by the partial dissolution and/or breakage of the shell wall. beautiful dissolution effects manifested by foraminifera are the internal moulds of hyaline perforated calcareous tests, such as valvulineria, elphidium, nonion depressulum and rosalina, and of agglutinated tests, such as textularia and dorothia. also a few individuals of quinqueloculina show internal moulds due to the partial dissolution of the test. this taphonomic feature is particularly evident in the mudstone associations of cycle 2 in arda and stirone sections. in the sandstone associations, the oxidation and/or pyritization are, generally, external. the tests assume an orange-brown and/or black staining and traces of test dissolution are rather rare. exceptions are the base of the sandstone interval of cycle 1, in the arda and enza sections, and the sandstone interval of cycle 3, in stirone section, where internal pyritized moulds of individuals of ammonia beccarii, valvulineria and quinqueloculina are also observable. focusing on the stratigraphic distribution of the different taphonomic categories, the high proportions of intact tests characterize assemblages from the mudstone partings of sandstone intervals when compared with the mudstone intervals (fig. 2). percentages of fresh tests increase eastward, reaching maximum values in samples of the tiepido section. on the contrary, the black or black-striped tests filled with or replaced by pyrite have higher percentages in the arda section, and decrease eastward. opaqueness of the tests is the dominant shell alteration in samples from the mudstone interval of cycle 1 and in basal samples of the mudstone interval of cycle 3 (the arda section). broken tests and/or fragmentation of the tests characterize the whole sedimentary cycles but show major frequencies in the mudstone intervals. a decrease in entity of this feature is observed in cycle 3 and eastward, with the exception s. stefanelli fig. 2 q-mode and r-mode clustering of the samples from the arda, stirone, enza and tiepido sections for the taphonomic analysis. raggruppamento in q-mode e r-mode dei campioni provenienti dalle sezioni arda, stirone, enza e tiepido per l’analisi tafonomica. 67 of the tiepido section. iron-stained tests are more frequent in the mudstone intervals. pitting shows its maximum effect at the base of cycle 1 in the arda area, but is rare in other cycles and in the other sections. 44..22 ppaalleeooeeccoollooggiiccaall aannaallyyssiiss the assemblages are taxonomically homogeneous in all the sections. differences concern the relative frequencies in the intervals of the sedimentary cycles. assemblages from the arda and stirone sections show the strongest affinities. similarity with the other sections, however, decreases eastward, across the enza and tiepido sections. fauna compositions are dominated by species of the genera ammonia, bulimina, elphidium, quinqueloculina, textularia, and by cassidulina carinata, with percentages up to 50%. fursenkoina schrebersiana, nonion depressulum, triloculina gibba and species of genera bolivina, rosalina, and valvulineria are subordinated, with percentages ranging from 0% to 18%. asterigerinata mamilla, bigenerina nodosaria, buccella granulata, cibicides lobutulus, dorothia gibbosa, planorbulina mediterranensis, pyrgo bulloides, reussella spinulosa, sigmoilopsis schlumbergeri and uvigerina of the “forms costate” group are rare, with percentages always lower than 3%. other taxa were scattered in the assemblages: astronion sp., cibicidoides pachydermus, globocassidulina subglobosa, globobulimina affinis, gyroidina umbonata, hanzawaia rhodiensis, hyalinea balthica, lamarkina scabra, lenticulina sp. melonis sp., nonionella turgida, sigmoilina tenuis, spiroloculina excavata, stainforthia complanata, trifarina angulosa. in fig. 3, the q-mode and r-mode dendograms are displayed. the samples arda 35 and arda 36, since they are barren in foraminifera, have been omitted. in q-mode dendrogram we distinguish the large clusters i and ii, and the small subclusters 1, 2 and 3. in r-mode dendrogram, we distinguish the large clusters a and b, and the minor subclusters c, d and e. cluster i groups samples belonging above all to the mudstone intervals. conversely, cluster ii is composed by samples belonging to sandstone intervals. subclusters within cluster i suggest a further subdivision of mudstone assemblages. subcluster 1 groups samples from cycle 2. subcluster 2 consists in tiepido samples. subcluster 3 mostly consists in samples of cycle 3. cluster a includes quinqueloculina gr. (the absolute dominating taxon in samples where it occurs), followed by t. gibba, p. mediterranensis, a. mamilla, and c. lobatulus. in cluster b, subcluster c groups together bulimina gr. and n. depressulum, subcluster d groups together c. carinata, bolivina gr. and s. schlumbergeri and subcluster e groups together textularia gr., taphonomic effects on ... fig. 3 – q-mode and r-mode clustering of the samples from the arda, stirone, enza and tiepido sections for the paleoecological analysis. raggruppamento in q-mode e r-mode dei campioni provenienti dalle sezioni arda, stirone, enza e tiepido per l’analisi paleoecologica. 68 valvulineria gr. and elphidium gr. noteworthy, ammonia gr. is a taxon common to all samples and so it is not associated to particular clusters. 55.. ddiissccuussssiioonn ooff tthhee ddaattaa 55..11 ttaapphhoonnoommyy the “fresh tests” category groups perfectly preserved intact tests (plates, figs. 1d, 3a, 5b, 7a, 8, 10, 12). the highest frequency of the “fresh tests” group is detected in the mudstone partings of the sandstone intervals of the arda, stirone and enza sections. this feature, together with the lesser traces of fragmentation, abrasion and/or dissolution, indicates that the taphonomic processes were not active or their effects were minimized in the lower part of the cycles. therefore, the taphonomic insights recorded may be suggestive of quiet paleoenvironmental settings, in which any transport at the bottom and any chemical process within the sediment involved the fauna. these taphonomic insights can also be suggestive of a different setting, strictly linked to poor oxygenated condition. the low oxygen availability may have, in fact, excluded the predatory fauna from the sediment itself thus limiting mechanical and digestive-chemical destruction. furthermore, the low oxygen availability may also have limited the ph decrease within the sediment pore waters which results from aerobic oxidation, thus limiting pore water carbonate dissolution (loubere, 1997). as a consequence, the tests are perfectly preserved. the quiet environmental scenario seems to contradict the taphonomical results drawn from mollusk fauna of the same stratigraphic intervals (dominici, 2001). the mollusk assemblages had, in fact, indicated catastrophic flooding events. focusing in detail on the shells included in the “fresh tests” category, it is observable that they belong, above all, to the order miliolida. by contrast, the fragments belong, above all, to the infaunal hyaline tests, such as those of ammonia sp., c. carinata, valvulineria sp. and elphidium sp. according to martin (1999), the nature of the tests, i. e. shell mineralogy, architecture of the microstructure and size, well controls the different states of preservation of the tests in the same shallow high-energy regime. therefore, the state of preservation of the microfauna detected in the sandstones may well be plausible with the shallow high-energy paleoenvironment. the porcelain tests of the order miliolida, having thick walls and a low number of pores, resulted to be more resistant than the hyaline tests which, on the contrary, have thin walls and a larger number of pores. different is the taphonomic signal detected in the sandstones of the tiepido section. the intact shells belong above all to the genus bulimina, which has a hyaline and thin test. by contrast, quinqueloqulina group is less frequent. this can suggest that going eastward the hydrodynamic setting changed. no transport involved the lower part of the cycle 3, thus indicating quieter scenario. the other taphonomic categories detected a group of tests coming above all from the mudstone parts of the cycles, whose original aspect is partially or totally modified. in these intervals, the great frequency of altered and broken tests and the lesser frequency of fresh tests could be suggestive of the great activity of the mechanical and chemical processes within the sediment. the alteration of the tests in light orange to dark brown color implies an iron staining process that may be from feso4 or fe(oh)2 derived from oxidation of fes2 (wang & chappell, 2001). the opacity of the tests, typical in forms whose walls were originally transparent, is indicative of the etching of calcite micro crystal edges in the tests under low ph condition (wang & chappell, 2001). pyritized tests indicate a set of chemical reactions, rather common in reduced organic muds (plates, figs. 1b, 5a, 6, 9a, b). the process of pyrizitation, often followed by partial or total dissolution of the tests, indicates strong stressed environmental conditions related, principally, to lack of oxygen (allison et al., 1995). the pitting indicates the bioerosion activity (plate 1, fig. 2), the traces of which are expressed by rounded holes (boltvskoy & wright, 1976). the broken tests and/or fragments are the effects of destruction that can be related to several causes (plates, figs. 1c, 1e, 3 c, d, 7b, 9 a, c). in a high-energy hydrodynamic regime the shell accumulation was put into suspension, the tests battered into each other and/or into the particles of the sediment and, consequently, fragmented. nevertheless, pitting is considered to be the initial phase of the dissolution of the foraminiferal carbonate by bacteria, which can lead, successively, to the disintegration of the chamber walls (freiwald, 1995). the bed preservation of the fauna in the mudstone intervals provides information about a paleoenvironment characterized by strong destructive effects. the presence of internal pyritized moulds is indicative of oxygen-poor marine environments. in low oxygenated muddy bioturbated environments, pyrite does not form in the body of the sediment but forms in anaerobic microenvironments, commonly within shells, where it forms internal moulds (martin, 1999). the absence, total or partial, of shells around the internal pyritized moulds is indicative of a dissolution process within the sediment. the total bioturbation state of the mudstone intervals of each cycle, in fact, supports the hypothesis of this process. dissolution is greatest in areas of high bioturbation since alkalinity is impeded by increased fluid through burrows and this also enhances carbonic acid production mediated by aerobic respiration (aller, 1982). dissolution effects can, therefore, well explain the high degree of fragmentation in the microfauna. the typical sequence of dissolution of pore-bearing taxa consists, in fact, in the gradual increase of corrosion and amplification of the pores and, in the end, the breakage of the chambers (martin, 1999). the relationship between the broken fraction with the dissolution process rather than hydrodynamics is well plausible with the interpretation of the mudstones as representing the return to the normal deposition after the catastrophic flooding events. unlike foraminifera, the mollusks, showing a more diverse fauna and dominated by venus multilamella, suggest normal aerobic conditions at the bottom (dominici, 2001). moreover, bivalves show no traces of pyritization: the only pyrite coatings in bivalves are detected in the sandstone assemblages. the different indications on the oxygen content given by these organisms may well be related to their s. stefanelli diverse style of life. venus multilamella lives on the seafloor, while cassidulina, bulimina, valvulineria, ammonia and elphidium live at a depth of 0.5 – 2 cm in the sediment column (murray, 1991; jorissen et al., 1995). this means that venus multilamella is influenced exclusively by dissolved oxygen content at the sea floor, unlike the infaunal foraminifera which are influenced by the oxygen concentration in sediment pore-water. thus, the coexistence of these micro and macro organisms in the same stratigraphic interval is plausible: the porewater sediment can be less oxygenated independently by the dissolved oxygen regime on the bottom-water. this is the same for the pyrite formation: it does not necessarily imply that the overlying water column was low oxygenated. certain morphologies of pyrite can be formed under broadly oxic conditions within anaerobic micro-environments (allison et al., 1995), as the presence of internal pyritized moulds of foraminifera in the oxygenated mudstones clearly confirms. still, the different effect of pyritization on the benthic organisms could be simply related to their tassonomical characteristics. in foraminifera, the pyrite formation depends on the ini69taphonomic effects on ... plate a different taphonomic aspects identified in the studied assemblages. the bar measures 0.25 mm. fig. 1 elphidium crispum. a: tests partially broken or dissolved showing the internal lining with pyrite; b: black stained test; c, e: broken shell; d: fresh test. fig. 2 tests of quinqueloculina seminulum showing the rounded holes, evident traces of pitting. a: dorsal side; b: ventral side. fig. 3 different states of preservation of tests of miliolids. a, b: fresh test of quinqueloculina seminulum and adelosina mediterranensis; c: deformed test; d: flatted test. differenti aspetti tafonomici riconosciuti nelle associazioni.studiate. la barretta misura 0.25 mm elphidium crispum. a: guscio parzialmente rotto o dissolto, con la cavità interna riempita di pirite; b: guscio nero; c, e: guscio rotto; d: guscio intatto. gusci di quinqueloculina seminulum mostranti i buchi rotondi, tracce evidenti di pitting. differenti stati di preservazione di gusci di miliolidi. a, b: gusci intatti di quinqueloculina seminulum e adelosina mediterranensis; c: guscio deformata; d: guscio schiacciato. tial shell structure and the capacity of access of iron and sulfate ions into shells (fischer, 1986), whilst only living mollusks, which get quickly buried under thick sandy beds, are not exposed to the complete degradation of the organic matter under aerobic conditions, and so, small pyrite coatings can form on the internal surfaces. the higher level of alteration shown by foraminifera, a component of the benthic community, could be explained through a longer residence in the taphonomically active zone recorded in the mudstone intervals (taz; see loubere, 1997; walker & goldstein, 1999). with this hypothesis, the mudstone intervals would represent a longer span of time with respect to muddy strata of comparable thickness from the sandstone intervals, in accordance with the general sedimentological setting (dominici, 2001). mudstones from sandstone intervals are, in fact, interpreted as produced by the waning phase of turbidity currents (dominici, 2001). 55..22 ppaalleeooeeccoollooggyy cluster a association can be considered representative of the mudstone partings of the sandstone intervals of each cycle, with the exception of the tiepido section (fig. 4). the association is formed by diverse and abundant individuals of quinqueloculina spp. and triloculina spp. scattered permanently attached forms 70 s. stefanelli plate b figg. 4, 6 black stained tests of bulimina elegans and valvulineria brayana. fig. 5 dorothia gibbosa. a: shell partially broken or dissolved showing the internal lining with pyrite; b: fresh test. fig. 7 pyrgo bulloides. a: fresh test; b: flatted test. fig. 8 fresh test of spiroloculina excavata. fig. 9 ammonia beccarii. a: broken and black stained test; b: shell partially broken or dissolved showing the internal lining with pyrite; c: fragment of test. gusci neri di bulimina elegans e valvulineria brayana. dorothia gibbosa. a: guscio parzialmente rotto o dissolto, con la cavità interna riempita di pirite; b: guscio intatto. pyrgo bulloides. a: guscio intatto; b: guscio schiacciato. guscio intatto di spiroloculina excavata. ammonia beccarii. a: guscio rotto e nero; b: guscio parzialmente rotto o dissolto, con la cavità interna riempita di pirite; c: frammento di guscio. such as c. lobatulus and p. mediterranensis and facultative mobile species such as asterigerinata sp. are also included. all these species have an epifaunal microhabitat preference commonly in well-oxygenated marine environments (murray, 1991). this fauna composition shows a strong similarity with the seagrass assemblages of the mediterranean, distributed at a depth of 2–40 m (murray, 1991). so, the restriction of the seagrass association to samples coming from sandstone intervals, interpreted as the result of the shallow water turbidity currents triggered by catastrophic flooding events, induces us to consider cluster a association as displaced, transported from shallower environments. this means that, since considered allochthonous, the taxa grouped in the association of cluster a must be subtracted from the paleoecological investigation. consequently, the fauna association is extremely poor, composed only of the taxa grouped in cluster b. the general sedimentologic aspect of the mudstone intervals and the nature of the macrofaunal association that it contains (dominici, 2001), allows, in fact, the interpretation of the fossil association of cluster b as autochthonous or parautochtonous. the scarcity of the fauna could well be related to the strongly stressed environmental condition in consequence of the high input of organic matter from the river that caused the consumption of oxygenation at the sea floor. the stressed environmental conditions, in fact, are hostile to life. in this context, the two samples barren in foraminifera, arda 35 and arda 36, both from cycle 3 of the arda section, would document an anoxic event. thus, the above-mentioned interpretation could be in good accordance with the hypothesis of hypoxic conditions at the bottom as suggested by the analysis of macrofaunal remains in life position from the sandstone interval of cycle 3 (dominici, 2001). however, the scarcity of the fauna could have been caused by the nature of the high hydrodynamic setting rather than the oxygen deficiency. the continuous impacts among the shells could have caused the destruction of a great part of the fossils. as, in fact, the taphonomic analysis indicated, the fragments belong to the delicate hyaline tests. the cluster b association can be considered diagnostic of the upper part of the cycles since it is better represented in mudstones (see always fig. 4). in the tiepido section this association characterizes also the lower part of cycle 3. within cluster b, the distribution of the associations in the subclusters c, d and e allows a further differentiation of the mudstone association from the three 71taphonomic effects on ... fig. 4 stratigraphic distribution of the associations of cluster a and cluster b throughout the sections. distribuzione stratigrafica delle associazioni dei clusters a e b lungo le sezioni. cycles (fig. 5). in the muds of cycle 1 the fauna is dominated, above all, by diverse species belonging to the genus bulimina (subcluster c association). c. carinata characterizes the muds of cycle 2 (subcluster d association). the species of the genus elphidium are abundant in the mud interval of cycle 3 (subcluster e association). ammonia gr. is abundant in samples from the enza section, particularly in sample en16 where its abundance reaches 78%, and in cycle 1 of the arda section. it decreases in the tiepido section. the taxa are common in modern muddy marine substrates from depths of 25 m downwards (murray, 1991). among them, c. carinata, valvulineria sp. bulimina gr., bolivina gr., are shallow infaunal typical of sediments that display low quantity of dissolved oxygen and rich in organic matter (murray, 1991; bergamin et al., 1992). ammonia spp. and elphidium spp. prefer well-oxygenated environments, though some species such as protelphidium granosum and ammonia beccarii var. tiepida show a moderate tolerance of lowered oxygen conditions (jorissen, 1988; murray, 1991). by schematizing the stratigraphic distribution of the subcluster associations, it is possible to reconstruct a fossil fauna replacement throughout the sedimentary cycles (fig. 6). in the upper part of cycles 1 and 2, the fossil association distribution suggests low oxygenated sediment pore-waters in shallow marine environment. in the upper part of cycle 3 the replacement by elphidium spp. and ammonia spp. seems to suggest a change in the environmental scenario, from a strictly shallow marine scenario to a lagoon one. individuals of ammonia and elphidium are, in fact, very abundant in stressed environments such as brackish lagoons and estuaries (murray, 1991). associations characterized by more than 60% of a. beccarii and a. tepida, as the frequency detected in the enza section, have been observed in the venice lagoon (albani & serandrei barbei, 1982). in the tiepido section, the replacement of bulimina spp association by the association rich in individuals of elphidium spp. and quinqueloculina spp. may well provide information about an increased dissolved oxygen content at the bottom-water surface towards the top of cycle 3. 72 s. stefanelli fig. 5 stratigraphic distribution of the associations of subcluster c, subcluster d and subcluster e, and of ammonia gr. throughout the sections. distribuzione stratigrafica delle associazioni dei subclusters c, d e e, e di ammonia gr. lungo le sezioni. 66.. ccoonncclluussiioonnss the foramoniferal taphonomic investigation represents a helpful tool in order to draw a correct paleoecological interpretation of the lower pleistocene. the investigation pointed out, in fact, that traces of paleoecological evidence had been lost over time. the destruction of the tests, the most evident post-mortem process, caused a substantial specimen loss in the fauna. part of the allochtonous or parauthocnous components has been lost. in particular, in the mudstone partings of the sandstone intervals, this loose had negative implications in the reconstruction of the paleoecological history. the fauna detected in the samples from these intervals is not able to support the reconstructed hypoxia condition at the bottom as suggested by the mollusks. the scarcity of the fauna, although typical of a hostile environment, can not be strictly related, in this case, to strong low oxygen availability. the high-energy setting induces, in fact, the hypothesis that the tests might have been totally destroyed, and, hence, no trace of their presence was detected. in the mudstone intervals, the low energy setting allowed the better preservation of the paleoecological signal. although the substantial specimen loss in the fossil association, strictly related to dissolution effects, the paleoecological results drawn from the micro fauna are well in accordance with the paleoecological results drawn from the macro fauna. aacckknnoowwlleeddggeemmeennttss thanks are due to the reviewers’ comments for the improvement of the manuscript. i wish to thank stefano dominici for the sampling of the sections and the discussions during the draft of the manuscript. financial support was provided by university of bari grant ex 60% (2003) to a. d’alessandro concerning the project “paleoecologia e biostratigrafia di successioni quaternarie dell’avanfossa sudappenninica”. rreeffeerreenncceess albani a. d. & serandrei barbero r. 1982 – a foraminiferal fauna from the lagoon of venice, italy. journal of foraminiferal research, 12(3), p. 234241. aller r. c. 1982 – carbonate dissolution in nearshore terrigenous muds: the role of physical and biological reworking. journal of geology, 90, p. 79-95. allison p. a., wignall p. b., brett c. e. 1995 – paleooxygenation: effects and recognition. in: bosence d. w. j. and allison p. a. eds: marine paleoenvironmental analysis from fossils. geological society special publication, 83, p. 97-112. barbieri r. 2001 – taphonomic implications of foraminiferal composition and abundance in intertidal mud flats, colorado river delta (mexico). micropoaleontology, 47, p. 73-86. barmawidjaja d. m., jorissen f. j., puskarics., van der zwaan g. j. 1992 – microhabitat selection by benthic foraminifera in the northern adriatic sea. journal of foraminiferal research, 22(4), p. 297317. bergamin l., di bella l., carboni m. g. 1999 – valvulineria bradyana (fornasini) in organic matter-enriched environment (ombrone river mouth, central italy). il quaternario, 12(1), p. 51-56. blanc-vernet, l., 1969 contribution à l’étude des foraminifers de mediterranée. trav. stat. mar. endoume, 48 (64), p. 1-281. boltovsky & wright 1976 recent foraminifera. w. junk publ., the hague, netherlands, 515 pp. caralp, m. h., 1989 size and morphology of the 73 fig. 6 schematic fauna replacement throughout the small-scale sedimentary cycles. sostituzione schematica delle fauna nei cicli sedimentari a piccola scala. taphonomic effects on ... benthic foraminifer melonis barleanum: relationship with marine organic matter. journal of foraminiferal research, 19 (3), p. 235-245. chierici, busi, cita m. b. 1962 contribution a une étude ecologique des foraminifères dans la mer adriatique. revue de micropaleontologie, 2, p. 123-142. corliss b. h. 1985 microhabitat of benthic foraminifera within deep-sea sediments. nature, 314, p. 435438 dominici s., 2001 – taphomony and paleoecology of shallow marine macrofossil assemblages in a coll isional setting (late pliocene-early pleistocene, western emilia, italy). palaios, 16, p. 336-353. douglas r. g., liestan j., walch c., blake c., cotton m. l. 1980 – the transition from live to sediment assemblage in benthic foraminifera from the southern california borderland. in: field m., bouma a., colburn i., douglas r. c., ingle j. eds: pacific coast paleogeography symposium. pacific station, 4, p. 256-280. fischer i. st. j. 1986 – pyrite replacement of mollusk shells from the lower oxford clay (jurassic) of england. sedimentology, 33, p. 575-585, freiwald a. 1995 – bacteria-induced carbonate degradation: a taphonomic case study of cibicides lobatulus from a high-boreal carbonate setting. palaios, 10, p. 337-346. hermelin, j. o. r. & smimmield, g. b., 1990 the importance of the oxygen minimum zone and sediment geochemistry in the distribution of recent benthic foraminifera in the northwest indian ocean. marine geology, 91, p. 1-29. jorissen f. j. 1988 benthic foraminifera from the adriatic sea: principles of phenotypic variations. utrecht micropaleontological bulletin, 34, 177 pp. jorissen f. j., barmawidjaja, d. m. puskaric, s., van der zwaan, g. j., 1992 vertical distribution of benthic foraminifera in the northern adriatic sea: the relation with the organic f lux. marine micropaleontology, 19, p. 131-146. jorissen f. j., de stigter h. c., vidmark j. g. v. 1995 a conceptual model explaining benthic foraminiferal microhabitats. marine micropaleontology, 26, p. 3-15. loubere p. & gary a. 1990 – taphonomic process and species microhabitats in the living to fossil assemblage transition of the deeper water benthic foraminifera. palaios, 5, p. 375-381. loubere p. 1997 – benthic foraminiferal assemblage formation, organic carbon flux and oxygen concentrations on the outer continental shelf and slope. journal of foraminiferal research, 27(2), p. 931000. martin r. e. 1999 – taphonomy, a process approach. cambridge paleobiology, series 4, p. 508. molinari f. 1997 – analisi di facies e stratigrafia fisica delle successioni plio-pleistoceniche affioranti lungo i torrenti stirone, arda e chero. unpublished tesi di laurea, dip. di scienze della terra, università di parma, parma, 80 p. milder t., migeon s., savoye b., faugèresj. – c. 2001 – inversely-graded turbidite sequences in the deep mediterranean. a record of deposits by floodgenerated turbidity currents? geo-marine letters, 21(2), p. 86-93 murray j. w. 1973 – distribution and ecology of living benthic foraminiferids. heinemann, london, 288 pp. murray j. w. 1976a – comparative studies of living and dead benthic foraminiferal distribution. in: hedley r. h., adams c. g. eds. foraminifera, 2, p. 45-109. murray j. w. 1983 – population dynamics of benthic foraminifera: results from the exe estuary, england. journal of foraminiferal research, 13, p. 1-12. murray, j.w., 1991 ecology and palaeocology of benthic foraminifera. longman scientif ic & technical, 312 pp. murray j. w. & alve e. 1999 – natural dissolution of modern shallow water benthic foraminifera: taphonomic effects on the paleoecological record. palaeogeography, palaeoclimatology, palaeoecology, 146, p. 195-209. mutti e. 1996 – il plio-pleistocene del torrente stirone: evoluzione delle conoscenze. xiii convegno società paleontologica italiana, excursion guide book, università di parma, parma, p. 33-34. phleger f. b. 1960 – ecology and distribution of recent foraminifera. johns hopkins press. baltimora, 297 pp. pieri p. 1983 – three seismic profiles through the po plain: in bally a. w. ed., seismic expression of structural styles. american association of petroleum geologists, studies in geology series, 15, 3.4/8-3.4.1/26. ricci lucchi f. 1986 – oligocene to recent foreland basins of northern apennines: in allen, p. h. and homewood p., eds., foreland basins. international association of sedimentologists, special publication. 8, p. 105-139. ricci lucchi f., colalongo m. l., cremonini g., gasperi g., iaccarino s., papani g., raffi s., rio d. 1982 – evoluzione sedimentaria e paleogeografica del margine appenninico: in cremonini g. and ricci lucchi f., eds., guida alla geologia del margine appenninico padano. guide geologiche regionali società geologica italiana. p. 16-46. sgarella f. & moncharmontt zei m. 1993 benthic foraminifera of the gulf of naples (italy): systematic and autoecology. bollett ino della società paleontologica italiana, 32(2), p. 145-264. staff g. m., stanton r. j., powell e. n., cummins g. 1986 – time-averaging, taphonomy and their impacts on paleocommunity reconstruction: death assemblages in texas bays. bulletin of the geological society of america, 97, p. 428-443. walker s. e & goldstein s. t. 1999 – taphonomic tiering: experimental field taphonomy of mollusks and foraminifera above and below the sedimentwater interface. palaeogeography, palaeoclimatology, palaeoecology, 149, p. 227-244. wang p. & chappel j. 2001 – foraminifera as holocene environmental indicators in the south alligator river, northern australia. quaternary international, 83-85, p. 47-62. 74 ms. ricevuto il 25 novembre 2003 testo definitivo ricevuto il 2 marzo 2004 ms. received: november 25, 2003 final text received: march 2, 2004 s. stefanelli imp.capezzuoli-sand. ii sseeddiimmeennttii qquuaatteerrnnaarrii ddeell sseettttoorree mmeerriiddiioonnaallee ddeellllaa vvaallddeellssaa ((pprroovviinncciiaa ddii ssiieennaa)) eennrriiccoo ccaappeezzzzuuoollii && ffaabbiioo ssaannddrreellllii dipartimento di scienze della terra, via laterina 8, 53100, siena. e.mail: capezzuoli@unisi.it; sandrelli@unisi.it riassunto: capezzuoli e. & sandrelli f., i sedimenti quaternari del settore meridionale della valdelsa (provincia di siena). (it issn 0394 – 3356, 2004). gli studi condotti sul settore meridionale della valdelsa (toscana meridionale) hanno permesso di caratterizzare e definire tramite ubsu i locali depositi quaternari. sono stati così riconosciuti sei sintemi (sintema di campiglia dei foci – cdf, sintema dell’abbadia – abb, sintema di calcinaia – cal, sintema del torrente foci – foc, sintema di bellavista – bel, sintema di poggibonsi – pog) che vengono riuniti sotto un unico supersintema indicato come supersintema del fiume elsa. il sintema di campiglia dei foci, composto da quattro litofacies (litofacies argillosa, litofacies sabbiosa, litofacies conglomeratica, litofacies calcarea), viene interpretato come l’espressione di un episodio palustre/lacustre datato al pleistocene inferiore-medio. i sintemi dell’abbadia, di calcinaia, del torrente foci e di bellavista sono riferiti ad una successione di terrazzi tutti caratterizzati da due litofacies (sedimenti calcarei concrezionari e sedimenti detritici) in proporzioni variabili nei vari sintemi e riferiti ad episodi di sedimentazione fluvio-palustre datati al pleistocene superiore-olocene sulla base di una datazione radiometrica. il sintema di poggibonsi corrisponde alle alluvioni attuali ed è formato da sedimenti detritici e localmente da sedimenti calcarei tuttora in formazione. mediante l’integrazione dei dati sedimentologici-stratigrafici con quelli geomorfologici, viene proposta una ricostruzione paleogeografica della valdelsa meridionale dal pleistocene inferiore-medio ad oggi. abstract: capezzuoli e. & sandrelli f., the quaternary sediments of the southern part of valdelsa basin (province of siena). (it issn 0394 – 3356, 2004). stratigraphic and geomorphological researches allow to characterize the quaternary deposits cropping out in the southern part of the valdelsa basin and previously named “ancient travertines” and “recent travertines”. the valdelsa basin is a segment of a nw-se oriented, tectonic depression extending from the serchio valley to the north, to the upper tiber valley to the south. this extensional structure, developed in late miocene, was filled up during pliocene with thick terrigenous marine sediments. afterwards, in the upper middle pliocene, the area, as well as most of southern tuscany, emerged. during quaternary the southern part of the valdelsa basin was characterized by episodic calcareous sedimentation. detailed geological investigations enable us to distinguish six quaternary synthems. campiglia dei foci synthem (cdf) – a palustrine/lacustrine synthem crops out in wide subhorizontal terraces with comparable altitudes (average quote 230 m). it is composed of four lithofacies: clayley lithofacies grey clay and clayey silt (max 10 m thick), locally characterized by thin, plane laminations and carbonaceous plant remains. the fossil content is represented by sporadic freshwater and terrestrial gastropods (parmacella), stems and oogons of charophyte and ostracods. in the san gimignano area, lignite-bearing beds, included in this lithofacies, were mined in the early xxth century, up to the total exhaustion, with fossil remains of mammals of earlymiddle pleistocene or of galerian. this lithofacies can be referred to a palustrine environment. calcareous lithofacies – compact, micritic limestone, locally rather vacuolar or with bioturbation (roots). the stratification is locally enhanced by thin silty-marly beds. it is interpreted as a lacustrine environment with highly concentrated caco3 waters. sandy lithofacies poorly cemented, fine-grained, quartzcarbonate sands in beds or lenticular layers (up to 50 cm thick), with a sometimes abundant silty matrix and locally scattered centimetric pebbles occur. in some outcrops, vegetable remains (grass stems and roots) encased in carbonate crusts are present. this lithofacies can be referred to the marginal part of the lacustrine/palustrine basin. conglomeratic lithofacies – conglomerates and paraconglomerates in variable amounts in the different areas of the basin. they are characterized by a medium size, sandy matrix and a commonly massive fabric, except for local moderate imbrication. this lithofacies is interpreted as alluvial fan deposit of small rivers. abbadia synthem (abb); calcinaia synthem (cal); torrente foci synthem (foc); bellavista synthem (bel) – four fluvial/palustrine synthems developed in four orders of terraces upon the recent alluvial sediments and localized along the flanks of the valleys of elsa river and torrents foci and staggia. the deposits of these syntems are represented by two lithofacies: calcareous deposits (t1) formed by bodies of concretionary phytoclastic-phytohermal calcareous tufas associated with compact micritic limestone and occasionally dark silty clays with organic matter; detritical deposits (t2) composed of mixed, terrigenous-carbonate silty sands and lenticular beds of gravels. the calcareous lithofacies are located in precise segments of the fluvial valleys; their origin is connected to springs with highly concentrated caco3 waters, perhaps hydrothermal. a radiometric c14 dating of 25690±180 yr bp performed on a peat layer inside the calcinaia synthem (cal) implies a probable late pleistocene-holocene age for these four synthems. poggibonsi synthem (pog) – fluvial synthem corresponding to the recent alluvial deposits and composed of sand and silty-sand with gravels. locally calcareous tufa are still in formation. these deposits are referred to the holocene. the collected data show that this sector of the valdelsa basin, during the early-middle pleistocene, was characterized by an episode of continental sedimentation. the initial clastic palustrine deposits (clayey lithofacies) and the following lacustrine carbonates (calcareous lithofacies) were both deposited in a probably tectonic depression. the uplifting of the area induced the rejuvenation of the local hydrographic system which cut deeply the pliocene sediments and caused a relevant inversion of relief. along this new hydrographic pattern, during the late pleistocene-holocene, the interaction of tectonic uplift and climatic changes caused the formation of four terraced orders (palustrine/fluvial synthems) locally characterized by the deposition of calcareous tufas. parole chiave: unità stratigrafiche a limiti inconformi, quaternario, travertini, valdelsa, italia. keywords: ubsu, quaternary, travertine, valdelsa, italy. il quaternario italian journal of quaternary sciences 1177(1), 2004, 33-40 34 e. capezzuoli & f. sandrelli 11.. iinnttrroodduuzziioonnee nell’ambito della cartografia geologica regionale alla scala 1:10.000 è stato effettuato uno studio multidisciplinare sul settore meridionale del bacino della valdelsa; in tale area compresa tra poggibonsi a nord, monteriggioni a sud, san gimignano a ovest e staggia senese ad est, affiorano sedimenti recenti prevalentemente carbonatici conosciuti in letteratura come travertini della valdelsa (merla & bortolotti, 1967). tale studio, che si è avvalso di indagini sedimentologiche, stratigrafiche, geomorfologiche (fotointerpretazione) e geocronologiche, ha permesso la definizione delle formazioni quaternarie affioranti nell’area ed il loro inquadramento mediante unità stratigrafiche a limiti inconformi (ubsu). gli studi stratigrafico-sedimentologici permettono una caratterizzazione di questi depositi ed un loro inquadramento paleoambientale e paleogeografico. 22.. iinnqquuaaddrraammeennttoo ggeeoollooggiiccoo il bacino della valdelsa coincide con un tratto di una lunga depressione tettonica con orientazione nwse che si estende dalla valle del serchio a nord fino alla alta valle del tevere a sud (fig. 1). tale bacino è interessato trasversalmente da due importanti lineamenti tettonici: la linea livorno-sillaro e la linea piombinofaenza. la prima delimita a nord il bacino, mentre la seconda, che lo attraversa all’altezza di poggibonsi, coincide con una forte diminuzione dell’ampiezza del bacino stesso da circa 25 km nella parte settentrionale a circa 15 km in quella meridionale (costantini et al., 1988). lateralmente il bacino della valdelsa è delimitato ad ovest dalla dorsale medio toscana, dove affiora principalmente il calcare cavernoso ed in misura minore verrucano, marmi, ofioliti, diaspri e argille a palombini, e ad est dalla dorsale del chianti con formazioni del dominio ligure esterno di età cretacica superiore-eocenica (formazione di santa fiora, formazione di monte morello). il bacino della valdelsa, individuatosi in regime distensivo nel miocene superiore (bossio et al., 1995b), è stato colmato da potenti spessori di sedimenti terrigeni continentali del miocene superiore a cui seguono sedimenti terrigeni marini del pliocene; questi ultimi, riferibili a due cicli sedimentari, sono formati principalmente da sabbie medio-fini (sabbie di san vivaldo) ed in misura minore da argille siltose (argille azzurre) (capezzuoli & sandrelli, 2003). nella parte alta del pliocene medio l’area emerge come la maggior parte della toscana meridionale (bossio et al., 1995a) e solo nel pleistoceneolocene è documentata una ripresa della sedimentazione con la deposizione di sedimenti continentali ed, in particolare, dei travertini. i primi autori che si sono occupati di questi depositi recenti sono pantanelli (1875) e del zanna (1901) che ne forniscono una prima generica caratterizzazione. successivamente, negli anni ’20-’30, prima trabucco (1920) e poi de castro & pilotti (1933), all’interno di relazioni sui giacimenti lignitiferi della toscana, trattano marginalmente dei travertini valdelsani. il primo studio si deve a merla & bortolotti (1967) che, nell’ambito della redazione del f°113 della carta geologica nazionale alla scala 1:100.000, distinguono, sulla base del loro contenuto in stronzio, i travertini antichi, di origine lacustre ed attribuiti al pleistocene superiore, dai travertini recenti, formati per idrotermalismo e riferiti ad un generico olocene. berzi (1972) attribuisce i travertini antichi al pleistocene inferiore-medio sulla base di una fauna a mammiferi r invenuta al loro interno, fauna che ambrosetti et al. (1972) collocano nel galeriano. più recentemente fazzuoli et al. (1982) riconoscono cinque diversi ordini di terrazzi con travertini nel bacino idrografico del t. foci, (se di san gimignano). ricerche pedologiche sui suoli e paleontologiche su malacofaune dei travertini antichi sono stati condotti da costantini & carnicell i (1986) e manganell i & giusti (1993). recentemente bossio et al. (2000), nell’ambito di studi condotti nell’area di monteriggioni, hanno studiato i travertini antichi attribuendo loro il nome di calcari di pian del casone. 33.. ssttrraattiiggrraaffiiaa ddeeii ddeeppoossiittii qquuaatteerrnnaarrii ddeellll’’aallttaa vvaallddeellssaa lo studio di fotointerpretazione e la distribuzione dei sedimenti quaternari dell’alta valdelsa, unitamente ai loro caratteri stratigrafico-sedimentologici, hanno permesso il riconoscimento di sei sintemi i cui rapporti sono indicati in fig. 2: un sintema lacustre-palustre (sintema di campiglia dei foci – cdf), quattro fluvio-palustri (sintema dell’abbadia – abb; sintema di calcinaia cal; sintema del torrente foci – foc; sintema di bellavista – bel) ed uno fluviale (sintema di poggibonsi – pog). questi sei sintemi vengono riuniti sotto un unico supersintema definito supersintema del fiume elsa (els). 33..11.. iill ssiinntteemmaa llaaccuussttrree--ppaalluussttrree:: ssiinntteemmaa ddii ccaammppiigglliiaa ddeeii ffooccii ((ffddcc)) si tratta di depositi localizzati principalmente in due placche suborizzontali (area di campiglia dei foci ed area compresa fra colle val d’elsa e staggia) ed altre di dimensioni inferiori, distribuiti a quote comprese tra 240 m (area di campiglia dei foci) e 230 m s.l.m. (area di pian del casone); nelle aree occidentali a ridosso della dorsale medio toscana le quote di affioramento, probabilmente per motivi tettonici, risultano superiori (quota massima 300 m s.l.m.). tali depositi giacciono di norma su sabbie marine plioceniche o direttamente sul substrato preneogenico; i contatti di base sono rispettivamente di tipo disconformity e angular unconformity, mentre a tetto si rinvengono suoli intensamente rubefatti (costantini & carnicelli, 1986). in alcune aree, alla sommità dei rilievi pliocenici, si osservano superfici relitte pseudorizzontali correlabili con la base dei depositi del sintema. la prevalente natura calcarea dei depositi del sintema (litofacies calcarea), meno erodibile dei sedimenti terrigeni pliocenici, ha provocato una erosione selettiva e determinato in quest’area una inversione del rilievo (bartolini & peccerillo, 2002). il sintema di campiglia dei foci presenta spessori variabili, che diminuiscono rapidamente verso nord; le potenze massime sono dell’ordine di 30 m. tale sintema è caratterizzato da quattro litofacies (fig. 2): litofacies argillosa (litofacies a): consiste di argille ed argille siltose grigie, a luoghi con una sottile laminazio35i sedimenti quaternari ... f ig . 1 s ch em a ge ol og ic o de l s et to re m er id io na le d el la v al de ls a. t1 s ed im en ti ca lc ar ei ; t 2 se di m en ti de tr iti ci ; a li to fa ci es a rg ill os a; c g lit of ac ie s co ng lo m er at ic a; s li to fa ci es s ab bi os a; c l lit of ac ie s ca lc ar ea . l e lit of ac ie s de l s in te m a c d f e i de po si ti de i s in te m i a b b , c a l, f o c e b e l, a q ue st a sc al a, n on s on o ev id en zi ab ili s in go la rm en te . g eo lo gi ca l s ch em e of t he s ou th er n v al de ls a b as in . t1 c al ca re ou s se di m en ts ; t2 d et rit ic al s ed im en ts ; a cl ay le y lit ho fa ci es ; c g co ng lo m er at ic li th of ac ie s; s s an dy li th of ac ie s; c l c al ca re ou s lit ho fa ci es . t he li th of ac ie s of th e c d f s yn th em a nd th e de po si ts o f t he a b b , c a l, f o c , b e l sy nt he m s ar e no t s ep ar at el y vi si bl e at th is s ca le . s in te m a di c am pi gl ia de i f oc i ( c d f ) cl s a cg _ _ _ f ir e n z e p is a d ors a le medio m . a lb an o i so la d 'e lb a g r o s s e t o rapolano mon ti pra tomagno s ie n a dell' a miata si c hi an ti cetona dorsa le a re e e m e rs e p ri n ci pa li d e p re ss io n i t e tt o n ic h e in te re ss a te d a b a ci n i m a ri n i e co n tin e n ta li n e o g e n ic i f a g lie f a g lie d i tr a sf e ri m e n to monte vo r a ch ve ca del d or . v e -c a -s i -b a ci n o d e lla v a ld e ls a -c a si n o -s ie n a toscana a re a s tu d ia ta pf ls l s l in e a l iv o rn o -s ill a ro p f l in e a p io m b in o -f a e n za 2 5 k m 0 v o -r a -c h b a ci n o d i v o lt e rr a -r a d ic o n d o lic h iu sd in o p og gi bo ns i c ol le v al d' e ls a s an g im ig na no s ta gg ia g ra cc ia no m on te rig gi on i c as te lli na s ca lo c am pi gl ia de i f oc i f. e lsa s in te m a de ll' a bb ad ia ( a b b ) s in te m a di c al ci na ia ( c a l) s in te m a de l t .f oc i ( f o c ) s in te m a di b el la vi st a (b e l) t2 t1 s in te m a di p og gi bo ns i ( p o g ) f. elsa f. elsa 1 k m u ni tà l ig ur i e t os ca na pr en eo ge ni ch e s ed im en ti m ar in i pl io ce ni ci s ed im en ti co nt in en ta li m io ce ni ci t. s ta gg ia t. f oc i t. foci b. im bo tro ni t. s ta gg ia 36 ne, caratterizzate da estensione variabile e spessore massimo di circa 10 m. lateralmente questa litofacies è eteropica con le sabbie e i conglomerati delle litofacies (cg) e (s) (si veda fig. 2), mentre al tetto è spesso visibile un passaggio graduale alla litofacies calcarea (cl). la sommità delle argille è caratterizzata da un livello pedogenizzato osservabile in due tagli artificiali. il contenuto paleontologico è caratterizzato da frustoli carboniosi, scarsi ostracodi e gasteropodi dulcicoli (lymnea stagnalis l., paludina contecta müll. e planorbis marginatus drap.) e terricoli (parmacella sp.1 sensu manganelli & giusti, 1993). nella zona a sud di san gimignano è stata inoltre segnalata l’esistenza di lenti di lignite, oggetto di coltivazione ai primi del ‘900 fino al totale esaurimento (trabucco, 1920; de castro & pilotti, 1933). queste lenti hanno fornito una fauna a mammiferi (equus caballus l., cervus elaphus l., bos primigenius boj., hippopotamus major cuv., elephas antiquus falc.) e molluschi attribuiti da berzi (1972) al pleistocene inferioremedio. successivamente ambrosetti et al. (1972), in un quadro classificativo più ampio dei depositi pleistocenici dell’italia centrale, hanno riferito questa stessa fauna al galeriano. questa litofacies argillosa viene attribuita ad un ambiente di tipo palustre. litofacies sabbiosa (litofacies s): consiste di sabbie fini calcaree con una frazione detritica silicea più o meno abbondante, ocracee e con occasionali nuvole o lenti di ciottoli centimetrici a basso grado di cementazione. i fossili presenti sono scarsi e rappresentati esclusivamente da resti vegetali incrostati (fitoclasti). le sabbie hanno una stratificazione pianoparallela non sempre evidente con spessori massimi di 50 cm. questa litofacies, che mostra rapporti di eteropia con tutte le altre litofacies (a) (cl) (cg), è riferibile ad aree marginali di lago/palude, nelle quali si avevano probabilmente spiagge legate a piccoli immissari. litofacies conglomeratica (litofacies cg sinonimo dei conglomerati di poggibonsi di merla & bortolotti, 1967): si tratta di conglomerati e paraconglomerati la cui composizione degli elementi varia passando dal settore orientale, dove si hanno soprattutto calcari e calcari marnosi, a quella occidentale a ridosso della dorsale medio toscana dove sono si hanno elementi derivati dal calcare cavernoso, “palombini”, diaspri ed ofioliti. il conglomerato solitamente si presenta massivo ed eccezionalmente si osservano clasti embriciati; la matrice, a luoghi predominante, è sabbiosa. la litofacies cg è interpretabile come l’espressione di piccoli delta posti prevalentemente sui lati occidentale ed orientale del lago/palude. litofacies calcarea (litofacies cl): è rappresentata da un calcare micritico, a grana fine o medio-fine, di colore bianco sporco con sfumature nocciola e/o rosa. la stratificazione è spesso ben visibile ed è messa in evidenza da sottili livelli siltoso-marnosi (max 15 cm nell’area di campiglia dei foci) interposti ai banchi calcarei spessi da 40 cm a circa un metro. a luoghi il calcare micritico è vacuolare, con evidenti bioturbazioni provocate da apparati radicali, oppure è associato a piccole lenti con strutture fitoclastiche. il contenuto paleontologico è sempre scarso; occasionalmente si ritrovano impronte interne di gasteropodi, mentre in sezione sottile si osservano ostracodi, steli ed oogoni di characee. il calcare giace generalmente sulle altre litofacies (a), (s), (cg) del sintema di campiglia dei foci, o, in misura minore, direttamente sui sedimenti pre-quaternari, anche se talvolta mostra rapporti di eteropia con le litofacies (s) e (cg). la litofacies (cl) viene interpretata come una deposizione per decantazione, al disotto del livello di base d’onda, nelle zone più profonde di un lago caratterizzato da acque ricche in carbonato di calcio. i rapporti tra le litofacies del sintema di campiglia dei foci (fig. 2) evidenziano un passaggio, verso l’alto, dalla litofacies argillosa a quella calcarea; questa transizione viene interpretata come una evoluzione da un ambiente palustre, con scarse profondità e sedimentazione prevalentemente terrigena, ad uno lacustre caratterizzato dalla sedimentazione di fanghi calcarei nelle aree centrali (litofacies cl) e la deposizione di materiali più grossolani nelle aree marginali, specialmente nelle vicinanze di piccoli immissari (litofacies s, cg). la variazione di sedimentazione da argillosa a calcarea è legata all’apporto di notevoli quantità di acque ad alto contenuto di caco3, verosimilmente collegata fig. 2 ricostruzione stratigrafica dei sei sintemi quaternari riconosciuti nel settore meridionale della valdelsa (non in scala). stratigraphic relationships of the six quaternary synthems recognized in the southern valdelsa basin (not in scale). e. capezzuoli & f. sandrelli 37 ad una accentuata attività tettonica inserita nell’ambito del generale sollevamento che ha interessato l’intera toscana meridionale dal pliocene medio ad oggi (bossio et al., 1995a). la deposizione del calcare, legata alla saturazione della acque, era favorita probabilmente sia da condizioni di endoreicità del bacino (vedi capitolo 4) che ne permetteva la progressiva concentrazione, sia da condizioni climatiche calde, come documentato dal ritrovamento di parmacella (manganelli & giusti, 1993), che accentuava l’evaporazione delle acque. 33..22.. ii ssiinntteemmii fflluuvviioo--ppaalluussttrrii:: ssiinntteemmaa ddeellll’’aabbbbaaddiiaa ((aabbbb)),, ssiinntteemmaa ddii ccaallcciinnaaiiaa ((ccaall)),, ssiinntteemmaa ddeeii ffooccii ((ffoocc)),, ssiinntteemmaa ddii bbeellllaavviissttaa ((bbeell)) questi sintemi sono riferibili ad una successione di terrazzi presenti sui versanti dei principali corsi fluviali dell’area e formati da depositi detritici prevalentemente di tipo terrigeno (sabbie, silt e ciottolami), che in particolari tratti vallivi (lungo il t.foci ad est di campiglia dei foci, lungo il botro degli imbotroni da pod. polveraria fino alla confluenza con il t.foci, lungo il f.elsa dall’abitato di gracciano fino a poggibonsi e lungo i l t.staggia da castellina scalo fino a poggibonsi; fig. 1) sono caratterizzati da litofacies calcaree (travertini recenti di merla & bortolotti, 1967). i depositi dei vari sintemi presentano estensioni variabili e spessori fino a circa 20 m. fra i diversi ordini di terrazzo, soprattutto nell’area di poggibonsi, affiorano le sabbie marine plioceniche (terrazzi a ripiani), anche se non mancano casi di terrazzi incastrati specialmente nella zona di colle val d’elsa-staggia e fra il sintema di bellavista ed il sottostante sintema di poggibonsi. tutti i sintemi sono caratterizzati da contatti basali erosivi (disconformity) e da una superficie superiore suborizzontale sulla quale si sono sviluppati suoli rubefatti o bruni. le unità più alte risultano in gran parte smantellate dall’erosione, ma restano documentate da numerose superfici relitte senza depositi. i sedimenti sono riconducibili a due litofacies che presentano gli stessi caratteri nei vari sintemi. litologicamente i depositi calcarei (litofacies t1 in fig. 1) si presentano come alternanze di calcare concrezionario fitoclastico e fitoermale incrostato su corpi vegetali (cannucce, arbusti e fili d’erba) e livelli detritici granulari (calcrete, sabbie calcaree) disposti in livelli e lenti di spessori variabili a seconda delle località. a luoghi si rinvengono caratteristici mound di cannucce (fitoermale) dovuti alla crescita degli organismi vegetali su piccoli rialzi del fondo. in associazione a questi litotipi si hanno livelli lenticolari di calcari micritici, calcari laminari cristallini ed occasionali livelli argillitici torbosi. tali caratteristiche permettono di classificare questi depositi come calcareous tufa di tipo “paludal model” o “fluviatile model” sensu pedley (1990) e pedley et al. (2003). i depositi detritici (litofacies t2 in fig. 1) sono solitamente composti da sabbie calcaree e terrigene e silt di norma malstratificati con associati ciottoli che, a seconda del luogo, possono essere presenti in lenti o livelli. le sabbie calcaree derivano dalla disgregazione, in regime turbolento, delle litofacies calcaree, mentre quelle terrigene dalle sabbie marine plioceniche; entrambe mostrano a luoghi banchi con sequenze di tipo fining-upward. i livelli a ciottoli sono presenti principalmente nella parte basale dei vari sintemi dove costituiscono il riempimento di tasche erosionali. sono composti da clasti eterogenei ben arrotondati di varie dimensioni (max 20 cm), che mostrano solo a luoghi una evidente embriciatura cui si accompagna una matrice sabbiosa variabile. lo scarso contenuto paleontologico di entrambe le litofacies è rappresentato da impronte di foglie di quercus ilex l. e populus laecophylla ung. (del zanna, 1901) e da ostracodi con carapace liscio e sottile, oogoni di carofite e calchi di gasteropodi dulcicoli. i sedimenti di questi sintemi sono attribuiti da merla & bortolotti (1967) all’olocene; recenti studi permettono un riferimento anche al pleistocene superiore, poiché una datazione radiometrica c14 su livello argilloso organico del sintema di calcinaia ha fornito un’età radiometrica di 25.690±180 b.p. (capezzuoli & sandrelli, 2003). sintema dell’abbadia (abb): è il più antico fra i fluviopalustri e corrisponde al terrazzo più alto, con una quota media di 30 m sull’attuale fondovalle. nell’area di l’abbadia (est di colle val d’elsa), il sintema è particolarmente sviluppato sia in estensione laterale sia come spessore (circa 18 m). in generale l’unità è ben conservata nelle aree di affioramento dei calcareous tufa, mentre si hanno solo deboli tracce in quelli di deposizione esclusivamente detritica e/o terrigena. sintema di calcinaia (cal): anch’esso è caratterizzato da calcareous tufa e depositi detritici e corrisponde ai terrazzi posti ad una altezza media di 25 m. recenti lavori stradali nell ’area di calcinaia (sud di poggibonsi) hanno evidenziato la presenza di un livello argilloso organico nella parte basale della sezione che ha fornito una datazione radiometrica di 25690±180 b.p.. sintema dei foci (foc): corrisponde ai depositi terrazzati presenti a quote medie di circa 15 m sul fondovalle. buoni esempi si hanno lungo il torrente foci (fig. 3) dove è anche possibile apprezzare una diminuzione nell’estensione dei depositi carbonatici rispetto a quelli presenti nei sintemi fluvio-palustri più antichi. sintema di bellavista (bel): a questo sintema appartengono i depositi terrazzati più recenti posti ad una quota di circa 8 m. anche qui continua il trend di diminuzione dei depositi carbonatici già notato nel sintema dei foci che sono sempre meno presenti in estensione lungo le valli. l’origine dei sintemi fluvio-palustri è probabilmente da riferire sia all’attività tettonica che ha accompagnato il sollevamento neogenico-quaternario della toscana meridionale, sia a variazioni climatiche. infatti alla prima sono da ricollegare la progressiva incisione delle valli fluviali e l’apporto di acque carbonatiche responsabili della sedimentazione dei calcareous tufa, mentre alle seconde vanno imputati i successivi episodi di sovralluvionamento e precipitazione dei calcareous tufa intervallati da fasi erosionali. questa precipitazione si realizzava solo in corrispondenza di alcuni tratti fluviali nei quali erano localizzate le sorgenti, probabilmente idrotermali, associate a faglie, responsabili degli apporti carbonatici. la relazione di questi depositi calcarei con faglie presenti nell’area era già stata ipotizzata da merla & bortolotti (1967), a causa dell’elevato contenuto in stronzio dei travertini recenti della valle del t. staggia, e da costantini et al. (1980). le sorgenti fornivano le i sedimenti quaternari ... 38 acque ad alto contenuto di caco3 che innescavano il processo d’incrostazione lungo il corso d’acqua, dove i sedimenti carbonatici si interdigitavano con quelli terrigeni e detritici dando luogo a frequenti eteropie di facies. lo studio dei depositi permette di individuare una variabilità degli ambienti deposizionali con passaggi da aree caratterizzate da ristagno delle acque (piccoli sbarramenti e stagni isolati con facies fitoermali o argille anche organiche) a zone di deflusso (aree di canale con accumuli fitoclastici, terrigeni o detritici). procedendo verso valle si aveva una progressiva diluizione delle acque calcaree, fino all’esaurimento della capacità incrostante ed alla deposizione solamente di depositi detritici. il minor sviluppo dei sedimenti carbonatici dai sintemi più antichi (sintema dell’abbadia) a quelli recenti (sintema di bellavista) indica, inoltre, una progressiva diminuzione degli apporti di acque carbonatiche che potrebbe essere messa in relazione ad una diminuzione dell’attività tettonica con l’occlusione delle vie di risalita. 33..33.. iill ssiinntteemmaa fflluuvviiaallee:: ssiinntteemmaa ddii ppooggggiibboonnssii ((ppoogg)) corrisponde alle alluvioni recenti, talvolta ben sviluppate nei fondovalle dei vari corsi d’acqua dell’area. sono formate essenzialmente da sabbie e silt sabbiosi con associati ciottoli o lenti di ghiaie. solo a colle val d’elsa (lungo il corso dell’elsa), localmente lungo il torrente staggia (a staggia senese) e in due località nei dintorni di san gimignano (nelle vicinanze di una sorgente idrotermale di esigua portata) sono tuttora in formazione i calcareous tufa. l’età di questo sintema è riferita all’olocene. 44.. iinntteerrpprreettaazziioonnee ppaalleeooggeeooggrraaffiiccaa eedd eevvoolluuzziioonnee ddeell sseettttoorree mmeerriiddiioonnaallee ddeellllaa vvaallddeellssaa nneell pplleeiissttoocceennee iinnffeerriioorree--mmeeddiioo - oolloocceennee con il generalizzato sollevamento della toscana meridionale iniziato nel pliocene medio, vaste aree a sedimentazione marina furono portate in emersione. l’assenza, nella parte meridionale della valdelsa, di depositi compresi fra il pliocene medio ed il pleistocene inferiore-medio, permette di ipotizzare che in tale intervallo l’elevato sollevamento di quest’area abbia dato luogo essenzialmente a processi erosionali legati all’instaurazione di un primo reticolo fluviale (paleo-elsa) probabilmente con andamento nw-se non dissimile dall’attuale. nel pleistocene inferiore-medio sono attualmente documentati i primi depositi continentali dell’area, rappresentati dai sedimenti prima palustri e successivamente lacustri del sintema di campiglia dei foci. una lettura della carta geologica e del reticolo idrografico della porzione meridionale della valdelsa permette una serie di ipotesi sulla paleogeografia dell’area in questa epoca. infatti la posizione degli affioramenti della litofacies calcarea (cl) consente la definizione dell’estensione minima del bacino durante lo stadio lacustre (fig. 4). lo studio dell’attuale reticolo idrografico fornisce ulteriori indizi sull’evoluzione di quest’area. in particolare in riva sinistra del f. elsa si osservano (fig. 4) vari corsi d’acqua tra loro paralleli con percorso in parte rettilineo e orientato in direzione appenninica, ma con verso di scorrimento opposto al f. elsa. al contrario, gli affluenti in riva destra possiedono un andamento circa antiapfig. 4 schema del reticolo idrografico principale del settore meridionale della valdelsa. hydrographic pattern of the southern valdelsa basin. fig. 3 visione da nord della valle del torrente foci ad est di campiglia dei foci. nello schema superiore sono evidenziati i depositi e le superfici relitte dei vari sintemi visibili. view of the torrente foci valley, east of campiglia dei foci. in the upper scheme the deposits and the older surfaces of the quaternary synthems are showed. foc abb cal abb pog cdf cdfcdf foc abb b.ro di vergaia b.ro degli im botroni t. r iguardi t. f oci b.ro del c onio t. f oci t. f oc i t. staggia f. elsa f. elsa f. elsa b.ro delle ferribbie poggibonsi colle val d'elsa certaldo staggia san gimignano t. d ro ve vico d'elsa ulignano linea piombino-faenza soglia ulignano-vico d'elsa cattura fluviale limite alluvioni recenti verso di scorrimento possibile limite paleolago 1 km e. capezzuoli & f. sandrelli penninico, ma anch’essi con una direzione preferenziale opposta al deflusso del f.elsa e quindi diretta verso le aree meridionali. questa peculiarità idrografica è presente fino all’altezza degli abitati di vico d’elsa ed ulignano, oltre i quale gli affluenti sia di destra che di sinistra assumono tracciati e deflussi verso i settori settentrionali. si viene così ad individuare, in corrispondenza di queste due località, un’area a sviluppo antiappenninico trasversale alla valdelsa che di fatto delimita verso nord il bacino lacustre. la conferma di una probabile soglia è avvalorata dal fatto che, coincidente con questa fascia trasversale, si ha una forte diminuzione nell’estensione laterale delle alluvioni recenti (sintema di poggibonsi) ben sviluppate sia a nord sia a sud. una possibile evoluzione di quest’area prevede un iniziale bacino di tipo endoreico formatosi per lo sbarramento del paleo-elsa in corrispondenza dell’area di ulignanovico d’elsa ed il conseguente adattamento dei corsi fluviali a defluire verso i settori meridionali. le cause della formazione di questa soglia, parallela e non molto distante da una importante linea tettonica (linea piombino-faenza; costantini et al., 1980) è da riferire a movimenti tettonici, anche se preliminari rilevamenti geologici svolti in quell’area, caratterizzata da una forte omogeneità dei sedimenti pliocenici, non hanno evidenziato la presenza in superficie di faglie. probabilmente gli stessi movimenti tettonici innescarono anche gli apporti di acque carbonatiche che variarono la sedimentazione del bacino da palustre/terrigena a lacustre/carbonatica. successivamente una probabile erosione regressiva del tratto settentrionale del paleo-elsa incise tale soglia determinando lo svuotamento del bacino lacustre (non sono presenti facies di regressione dei depositi lacustri). conseguentemente anche gli immissari del paleolago, pur mantenendo parziali tratti con l’originale pattern centripeto verso le aree lacustri, avrebbero subìto la cattura da parte di altri corsi d’acqua, variando così il proprio percorso (fig. 4). questa nuova idrografia, impostatasi dopo l’apertura del bacino, ha subìto fino ad oggi un progressivo approfondimento, attuatosi sia per il continuo sollevamento tettonico, sia a causa di variazioni climatiche. in gran parte dell’area si è quindi avuto un’inversione del rilievo con i sedimenti del paleolago, molto competenti, r imasti spesso inalterati in posizione ri levata. l’approfondimento, realizzatosi con meccanismi di sovraimposizione a scapito delle sabbie marine plioceniche, è avvenuto lungo il nuovo pattern idrografico che si era impostato sulla base delle mutate condizioni paleogeografiche (tratti sinuosi incassati del f. elsa fra colle val d’elsa e poggibonsi e del t. staggia fra staggia senese e poggibonsi che documenterebbero estesi ambienti alluvionali successivi al paleolago) e tettoniche (tratti rettilinei del f. elsa a colle val d’elsa in corrispondenza di faglie). negli interstadi delle fasi di approfondimento fluviale si aveva la deposizione di sedimenti terrazzati che in alcuni tratti erano di tipo calcareo (calcareous tufa) grazie ad acque idrotermali carbonatiche risalite lungo alcune faglie. la formazione dei calcareous tufa è diminuita nel tempo, come testimoniato dalla minore presenza di sedimenti calcarei nei sintemi più recenti (sintema del t. foci, sintema di bellavista), f ino ad arrivare ai deposit i attuali (sintema di poggibonsi) dove le acque del f. elsa formano calcareous tufa solo in poche località. la progressiva diminuzione dei depositi “travertinosi” nel tardo olocene è un fenomeno generalizzato sia in italia che in molti siti dell’europa centro occidentale e riconducibile a cause di tipo climatico o antropico (goudie et al., 1993; dramis et al., 1999). tuttavia in valdelsa potrebbe essere legata ad una risposta più locale e riferita ad una diminuzione dell’attività tettonica conseguente ad un possibile progressivo arresto del sollevamento post-pliocene medio. rriinnggrraazziiaammeennttii gli autori ringraziano la prof.ssa a. gandin per la collaborazione nello studio sedimentologico delle facies carbonatiche. lavoro finanziato con fondi p.a.r. 2001 dell’ università degli studi di siena (responsabile prof. f. sandrelli). llaavvoorrii cciittaattii ambrosetti p., azzaroli p., bonadonna f.p. & follieri m. (1972) – a scheme of pleistocene chronology for the tyrrhenian side of central italy. boll. soc. geol. it., 9911, 169-184. bartolini c. & peccerillo a. (2002) – i fattori geologici delle forme del rilievo. lezioni di geomorfologia strutturale. pitagora editrice, bologna, 216 pp. berzi a. (1972) an early middle pleistocene fauna at monte oliveto (s. gimignano, siena, italy). paleont. it. , 6688, 29-33. bossio a., costantini a., foresi l.m., lazzarotto a., mazzanti r., liotta d., mazzei r., salvatorini g. & sandrelli f. (1995a) – studi preliminari sul sollevamento della toscana meridionale dopo il pliocene medio. studi geol. camerti, volume speciale, 1995/1, 87-91. bossio a., foresi l.m., mazzei r., salvatorini g. & sandrelli f. (1995b) evoluzione tettonico-sedimentaria neogenica lungo una trasversale ai bacini di volterra e della val d’elsa. studi geol. camerti, volume speciale, 1995/1, 93-104. bossio a., mazzei r., salvatorini g. & sandrelli f. (2000) – geologia dell’area compresa tra siena, poggibonsi e castellina in chianti (prov. di siena). atti soc. tosc. sc. nat. mem. serie a, 110077, 69-85. capezzuoli e. & sandrelli f. (2003) – inquadramento geologico della porzione meridionale del bacino della valdelsa. guida all’escursione “l’agricoltura che produce paesaggio”; convegno nazionale “qualità del suolo, impatto antropico e qualità dei prodotti agricoli.”, pag. 78-80, siena, 912/06/2003 costantini a., gandin a., guasparri g., lazzarotto a., mazzanti r. & sandrelli f. (1980) – neotettonica dei fogli: 111 livorno – 112 volterra – 113 castelfiorentino – 119 massa marittima – 120 siena – 121 montepulciano – 126 isola d’elba – 127 piombino – 128 grosseto – 129 s.fiora. in: contributi al la realizzazione della carta neotettonica d’italia. pubbl. p.f.g., 1075-1186. costantini a., lazzarotto a. & sandrelli f. (1988) sulle risorse geotermiche a medio-bassa temperatura 39i sedimenti quaternari ... nella parte meridionale del bacino neoautoctono della val d’elsa. studi preliminari: lineamenti geologici. p.f.e. s.e.g., si-5, 489-514. costantini e.a.c. & carnicelli s. (1986) – forme e suoli della superficie strutturale calcarea di campiglia dei foci (siena). annali ist. sper. dif. suolo, 1177, 68-87. de castro c. & pilotti c. (1933) – i giacimenti di lignite della toscana. mem. descr. carta geol. d’it., 2233, 95-103. del zanna p. (1901) – i travertini di colle e le incrostazioni attuali dell’elsa. boll. soc. geol. it., 2200, 2034. dramis f., materazzi m. & cilla g. (1999) – influence of climatic changes on freshwater travertine deposition: a new hypothesis. phys. chem. earth (a), 2244(10), 893-897. fazzuoli m., garzonio c.a., rodolfi g. & vannocci p. (1982) lineamenti geologici e geomorfologici dei dintorni di san gimignano. ist. sper. stud. dif. suolo, firenze, 1133, 169-203. goudie a.s., viles h.a. & pentecost a. (1993) – the late-holocene tufa decline in europe. the holocene, 33(2), 181-186. manganelli g. & giusti f. (1993) – notulae malacologicae, xlv. fossil parmacellidae from italy. arch. molluskenkunde, 112211, 143-156. merla g. & bortolotti v. (1967) – note illustrative della carta geologica d’italia alla scala 1:100.000. foglio 113 – castelfiorentino. nuova tecnica grafica, roma. pantanelli d. (1875) – sui travertini della provincia di siena. soc. tosc. nat., proc. verb., 4-7. pedley h.m. (1990) – classification and environmental model of cool freshwater tufas. sedimentary geology, 6688, 143-154. pedley m., gonzalez martin j.a., ordoñez delgado s. & garcia del cura m.a. (2003) – sedimentology of quaternary perched springline and paludal tufas: criteria for recognition, with examples from guadalajara province, spain. sedimentology, 5500, 23-44. trabucco g. (1920) – stratigrafia, origine, età, applicazioni della lignite torbosa-xiloide del bacino di monte oliveto. boll. soc. geol. it., 5544, 314-324. 40 ms. ricevuto il 4 novembre 2003 testo definitivo ricevuto il 13 gennaio 2004 ms. received: november 4, 2003 final text received: genuary 13, 2004 e. capezzuoli & f. sandrelli 04mcbrideetal subsurface visualization using ground-penetrating radar for archaeological site preparation on the northern slope of somma-vesuvius: a roman site, pollena trocchia, italy j. h. mcbride†1, r. w. keach1, r. t. macfarlane2, g. f. de simone3, c. scarpati4, d. j. johnson5, j. r. yaede1, g. s. macfarlane6, r. w. r. weight1 1department of geological sciences, brigham young university, provo, utah usa, e-mail: john_mcbride@byu.edu 2apolline project, department of classics, brigham young university, provo, utah usa 3st. john’s college, university of oxford, oxford, united kingdom 4dipartimento di scienze della terra, università degli studi federico ii, napoli, italy 5department of anthropology, brigham young university, provo, utah usa abstract: j. h. mcbride et al., subsurface visualization using ground-penetrating radar for archaeological site preparation on the northern slope of somma-vesuvius: a roman site, pollena trocchia, italy. (it issn 0349-3356, 2009). the use of non-invasive geophysical techniques is becoming increasingly important in archaeological site studies as a means to increase the efficiency of excavation and to thereby avoid unnecessary disturbance. ground-penetrating radar (gpr) surveys were performed over an orthogonal grid in order to guide the decision-making process for planning excavation at a roman site in pollena trocchia (italy), located just off the nw flank of somma-vesuvius. archaeological planning for this site is complicated by contextual disruption and intermittent backfill, sometimes exacerbated by its proximity to building sites and by its use as a landfill, and by prior archaeological excavation and subsequent remediation. from a geophysical point of view, the site at pollena trocchia provided an ideal test-bed for visualization experiments (a) because the ground surface was readily cleared and smoothed by earth-moving machinery and (b) because the soil derived from geologically recent volcanic ash was dry at the time of the survey. state-of-the-art geophysical visualization techniques were applied to the pseudo-3d gpr data using conventional displays, seismic attribute analysis, and waveform connectivity schemes as employed in petroleum exploration. in this way, we assess the value of applying strategies adapted from industrial 3d seismic imaging to the problem of defining the effects of previous disturbance at a complex archaeological site. riassunto: j. h. mcbride et al., visualizzazione subsuperficiale tramite ground-penetrating radar per la preparazione di un sito archeologico sul versante settentrionale del somma-vesuvio: un sito romano, pollena trocchia, italia. (it issn 0349-3356, 2009).. l'uso di indagini geofisiche di tipo non-invasivo sta diventando sempre più rilevante nella ricerca archeologica, poiché incrementa l'efficienza dello scavo e riduce le attività non necessarie. l'indagine georadar (gpr) su griglia ortogonale è stata utilizzata per il sito romano nel comune di pollena trocchia (in provincia di napoli, sul versante settentrionale del somma-vesuvio) per la pianificazione delle attività di scavo. l'area oggetto d'indagine risulta di complessa lettura, poiché disturbata da alcuni tagli e riempimenti relativi alla costruzione di edifici nelle vicinanze, alla scoperta del sito, ed al successivo accumulo di materiali. dal punto di vista geofisico, il sito di pollena trocchia può essere considerato un caso-studio ideale per esperimenti di visualizzazione, in quanto: (a) la superficie risultava molto piana e ripulita dalla vegetazione spontanea con mezzo meccanico; (b) il suolo, di origine vulcanica, era particolarmente asciutto durante l'indagine. le più recenti tecniche di visualizzazione geofisiche sono state applicate a dati pseudo-3d grazie all'uso di visualizzazioni convenzionali, analisi degli attributi sismici, e schemi delle onde di connettività simili a quelle utilizzate per le indagini petrolifere. in tale modo, è stato possibile valutare l'applicabilità di visualizzazioni sismiche 3d di tipo industriale per l'analisi di anomalie all'interno di un contesto archeologico keywords: radar, geophysics, roman age, italy, vesuvius, volcanic. parole chiave: georadar, geofisica, età romana, italia, vesuvio, riempimento vulcanico. il quaternario italian journal of quaternary sciences 22(1), 2009 39-52 introduction the past several years have witnessed a steady expansion in using ground-penetrating radar (gpr) to provide images of the remains of human habitation and related building structures at buried archaeological sites (conyers, 2004; conyers, 2007; goodman et al., 2007). with the ready availability of advanced, but easy-to-deploy field acquisition systems, gpr data can be surveyed along parallel lines or grids and processed into a pseudo-3d data volume (for the bistatic case with two bow-tie dipoles separated with a constant offset). much of the published research on 3d gpr visualization has utilized computer applications that have been developed specifically for radar applications. in this study, we present the results of experimenting with state-of-the-art 3d visualization techniques and strategies adapted from petroleum exploration but applied to imaging the effects of previous episodes of excavation and ground disturbance at an archaeological site. the study area is a locale known formally as masseria de carolis, a tract of vacant land in the town of pollena trocchia. beneath the surface of the landscape a roman site lies buried by volcanic deposits from somma-vesuvius. the site was found in 1988 (pagano, 1992) during building excavations for the highrise apartment complex nearby. renewed interest since 2005 has made the site the focus of an ongoing archaeological study undertaken by the università degli studi “suor orsola benincasa” of naples and brigham 40 j.h. mcbride et al. young university, with participating colleagues joining from other institutions. this team, called the apolline project, also includes the administration of the comune di pollena trocchia. most recent excavations were carried out by the apolline team in summer, 2007 (de simone et al., 2007). this archaeological project seeks to add further knowledge to that ascertained by the preliminary excavations at the site by pagano (1992). accurate detection and mapping of previous disturbance of the ground, it was reasoned, would be useful for planning future excavations and for avoiding confusion when interpreting the results of an excavation that may have crossed into an area previously disturbed. in this study we focus mainly on features that represent previous disturbance and not on possible archaeological features. the archaeological aspects of the site are only briefly mentioned here, in order to provide a setting for the gpr visualization analysis. cultural setting of the site discovery and project overview the site at masseria de carolis was discovered accidentally in 1988 and studied in 1991-92. in an admittedly “brief excavation campaign,” without achieving the floor of any space nor fully determining the plan of any complete room nor discovering any dating material, pagano surmised that the site was a granary (“grandi magazzini di ammasso di prodotti agricoli”) constructed in the 2nd century ad. pagano posited, further, that disruption in the parietal fabric might have been caused by mid-18th-century quarrying at the site; perhaps it was the source of 12,000 bricks reportedly extracted from the area of pollena and reused by the bourbon kings in the building of the teatro san carlo in naples. while pagano’s interpretation of the site seems more uncertain, as the apolline project goes forward, his optimism that the site will yet reveal important evidence for the ancient economy on vesuvius’ northern slope seems certain to be confirmed. pagano (1992) refers to a trench measuring 10 x 10 m, which he sunk with earth-moving equipment “a short distance north-east” of the roman walls that comprise the site itself. while his publication does not specify the location of that trench, the negative conclusions he records are important for certifying that the ancient building’s lateral profile did not extend far from the walls he discovered. the location of that trench will be discussed in this article, below. after the brief archaeological campaign reported by pagano, the masseria de carolis was returned nearly to its status quo ante. a wire fence was strung around wooden posts to demarcate the central area of the 1990’s excavation; all other areas in the lot were backfilled with construction rubbish. illegal disposal of more-or-less clean fill occurred over time, and by 2006 even the fenced section had been compromised and filled with trash. nearly all signs of earlier excavation were again buried beneath the landscape’s surface. description of archaeological features field work activities during the 2007 archaeological campaign brought new relevant data for understanding not only the site itself, but also the broader geographical and cultural frameworks, almost unknown until recently (de simone, 2007). the excavation, the analysis of material cultural remains, and more broadly the multidisciplinary project itself are still in a preliminary phase; thus it is impossible to define clearly the character of the site and the phases of its occupation. nevertheless, the description of what is currently visible is fundamental (a) for understanding the reasons for the setting of the gpr test areas and (b) as a comparative data set for what we would (or would not) expect to find in the gpr test areas. the area appears essentially flat and almost at the same level of the archaeological remains, due to the excavations performed in the ‘80s. on the east side, where one of the gpr test areas is, the ground rises for about 1.5 m above the archaeological remains. south of the site, in the area used in the ‘80s as quarry for volcanic ash, the trash illegally dumped there is still present and makes it therefore difficult to define the boundaries of the ancient structures in that area. the visible archaeological remains show at least 7 rooms, most of which are still partially or completely roofed (fig. 1b: a, b, c, d). there are still traces in some points (c, e, f) of the ancient cocciopesto pavement. this information, together with the collapse remains of some walls (g, h), lead us to the conclusion that the structure had an upper floor. the structures now visible are probably built in the 2nd/3rd century ad on the top of a pre-79 ad building, as the presence of fresco fragments and volcanic ash beneath the foundation trenches suggests. the building was used for a few centuries, then buried as much as two thirds of its height by the late-antique 472 ad eruption. the dating of volcaniclastic materials is confirmed by the presence, in the last anthropized context, of a burial of a six-yearold boy with a bronze coin dated to the period of marcian (emperor of the eastern roman empire in 4507). on the top of the 472 volcanic fill are bricks and stones taken from the surrounding walls packed together for raising the floor level. on the top of it is a poorlymade oven (i), sealed together with the surviving remains of the building by the 512 ad and subsequent eruptions (see following paragraph). gpr analysis was set up for hypothesizing, in a non-destructive and time-efficient manner, how and in which direction the building continues underground. the choice of the areas for performing the gpr scanning was determined by several considerations on the surviving structures: the remains of cocciopesto floor on the east side of the site (f) suggest in fact the continuation of the structures beneath the latest fills, with the presence of a probably well preserved room beneath it. the other side of the building seemed a quite promising area as well, for all the rooms are aligned along an e-w axis and therefore we expected more structures along that axis. moreover, the cocciopesto floor e shows no clear boundaries on the north side, therefore the nw corner was the most promising area for performing large-scale gpr analysis. the south side of the site, as explained above, was used in the ‘80s as quarry for construction materials and then filled by illegal dumping. consequently no gpr could be performed along this side of the structure. physical geology of the site general background the pollena trocchia archaeological site is located on the northern slope of somma-vesuvius at an elevation of about 90 m. the site covers an area of almost 400 m2 and has been excavated to 5 m as of summer 2007 (fig. 1). the excavation has revealed a large roman building, which had been buried by pyroclastic and reworked volcaniclastic deposits belonging to the somma-vesuvius volcanic complex. because the gpr surveys were targeting features within the volcanic products, we summarize the stratigraphy of the volcanic succession. the somma-vesuvius volcanic com41subsurface visualization using ... plex results from repeated explosive eruptions, usually from a central vent, that produced stratified pyroclastic deposits and lava flows (santacroce, 1987; sulpizio et al., 2007). the volcanic products erupted by sommavesuvius are not ubiquitously distributed around the volcano but crop out according to their eruptive and emplacement mechanisms and the topography. toward the summit of somma-vesuvius and along the axis of the most deeply excavated valleys, ancient lavas and scoria cones are exposed. the products of this prevailing effusive activity are covered by the products of explosive eruptions ranging from weak strombolian (e.g., 1874 eruption) to extremely powerful plinian (e.g., 79 ad eruption). the products of numerous pyroclastic density currents are well exposed along the volcano’s northern flank. thick and massive deposits are confined in the valleys that flowed from the volcano; conversely, thinly stratif ied deposits crop out on the interfluves and in the plain. heavy rainfall occurring during and after the explosive eruptions generated floods that easily eroded and mixed largely uncompacted primary deposits to form lahars. lahars, which are generated on the steep slopes above, inundated areas far away from their sources. the resulting deposits occur in the valleys and on lowlands (perrotta et al., 2006a; b), including pollena trocchia. volcanic stratigraphy the exposed sequence in the excavation site is made up of seven stratigraphic units (fig. 2). each unit is denoted by a letter from a to g younging upwards. the basal volcaniclastic sequence consists of five, decimeter to about 2 m thick, massive deposits (a1, a3, a5, a7 and a9) interstratified with thin ashy horizons (a2, a4, a6 and a8) (fig. 2). massive deposits are matrix-supported and lithicrich. the matrix is light brown in color. lithic clasts are up to 12 cm in diameter and generally not graded. lithic types include reddish altered lavas, gray aphiric lavas and limestone fragments that range in shape from angular to rounded. thin ashy layers are stratified and show a lateral variation in thickness. scattered whitish pumice clasts are dispersed in these layers. a thin paleosol separates this volcaniclastic sequence figure 1 (a) location map for gpr survey and archaeological excavation underway as of summer 2007 (de simone et al., 2007). the map is rendered as patterns observed from an aerial photograph of the site on which higher intensity mostly represents vegetation and lower intensity mostly represents bare or poorly vegetated ground. [map overlay: massimo manfellotto] (b) schematic map of the archaeological site and gpr survey areas. [drawing: salvatore borrelli; editing: massimo manfellotto]. (a) localizzazione dell’indagine gpr e dello scavo archeologico in corso nell’estate 2007 (de simone et al., 2007). la pianta è realizzata con tematizzazioni tratte dalla foto aerea del sito: il tratteggio più denso rappresenta la vegetazione, quello meno denso le aree povere o prive di vegetazione. [mappa sovrapposta: massimo manfellotto] (b) mappa schematica del sito archeologico e dell’area indagata con gpr. [disegno: salvatore borrelli; edizione: massimo manfellotto]. 42 from a thinly stratified deposit (b1), defined by the alternation of fine-grained, plane-parallel laminae interlayered with coarse ash layers (fig. 2). the upper bed, b2, is comprised of thick, stratified ash layers. a thin reddish paleosol is observed at the top of the succession. unit b is overlain by a stratified deposit (c1 to c3). this horizon is covered by a thick paleosol (p4). the remnant part of the succession is made up by four thin pyroclastic layers (d, e, f and g) interstratified with paleosols. layer d is a laterally discontinuous, fine ash layer. layer e is a massive, well sorted, fine lapilli gray scoria layer. the coarse-ash layer f is discontinuous, with abundant lithic fragments. finally, the fine ash layer g shows rare scoria dispersed in the matrix. the stratigraphic units are tentatively correlated with the historical eruptions of vesuvius on the basis of their lithostratigraphic characteristics. above the roman floor as currently excavated, the products consist of thick volcaniclastic beds (unit a) (fig. 2) associated with the 472 ad vesuvius eruption. as stated above this correlation is strongly supported by the presence of a coin dated 450-457 at the base of this deposit. the 472 ad deposit is capped by a very discontinuous and thin paleosol that is covered by stratified and massive ash-bearing beds (unit b). the presence of a poorly developed soil suggests that the products of unit b were emplaced after a brief quiet period following the 472 ad eruption and are consequently related to the 512 ad eruption. the upper, thin pyroclastic deposits are possibly related to the medieval eruptions of vesuvius; in particular layer f could be associated to the 1631 eruption. as part of this study, we excavated a small trench in the sw corner of the survey area (fig. 3). the results of the trench locally show two layers: (1) an upper layer, between the surface and 0.5 m depth, of modern soil and modern soil mixed with building rubbish (e.g., tiles, rebar, electrical wiring, etc.); and (2) a deeper layer of stratified volcanic ash. figure 2 stratigraphic column for the volcanic succession at the pollena trocchia site with interpreted intervals of eruptions noted. triangles: lithic-rich 472 ad deposits; circles: ash and pumice post-472 ad deposits; gray darkening upwards: paleosol. colonna stratigrafica della successione vulcanica del sito di pollena trochia con annotazione interpretativa degli intervalli eruttivi. triangoli: depositi dell'eruzione del 472 d.c. ricchi in litici; cerchi: ceneri e pomici delle eruzioni post-472 d.c.; campi in grigio che si scuriscono verso l'alto: paleosuoli. figure 3 interpretation of soil and volcanic layering from the trench excavated near the sw corner of the gpr survey site (fig. 1). “1” and “2” refer to layering observed in the gpr vertical views (fig. 5). the patterns on the drawing represent differing materials observed in the trench. [drawing: annie peterson; digitization: massimo manfellotto]. interpretazione della stratificazione vulcanica e del suolo nel saggio scavato nei pressi dell’angolo so del sito indagato (fig. 1). ‘1’ e 2’ si riferiscono alla stratificazione osservata nella sezione verticale del gpr (fig. 5). i motivi nel disegno rappresentano i diversi materiali osservati nel saggio. (disegno: annie peterson; digitalizzazione: massimo manfellotto). j.h. mcbride et al. 43 gpr data data acquisition dry volcanic ash, such as covers our study area, can provide an ideal medium because of its relatively low clay content, low electrical conductivity, and orderly stratification. gpr has been successful in revealing the pre-excavation configuration of archaeological sites buried by volcanic ash or volcaniclastic deposits in many places (e.g., russell & stasiuk, 2000). perhaps the best known example, apart from the wellknown vesuvian sites such as pompeii, is the joya de ceren archeological site in el salvador (sheets, 2005). the rapid burial of the site under several meters of volcanic ash led to the remarkable preservation of the daily life activities, food, and personal belongings of this pre-columbian community. the radar survey at pollena trocchia used a gssi 400-mhz antenna and recording unit in bistatic mode (transmitter and receiver set at a fixed distance within the antenna casing). an orthogonal grid was surveyed over a rectangular areas of ~520 m2 (5600 ft2) with lines spaced at ~0.30 m (1 ft). the survey areas were positioned so as to be as close as possible to the present excavation (de simone et al., 2007) (fig. 1). positioning of the gpr tracks was constrained by exact measurements on the ground and guided by a network of string. the gpr tracks were acquired in continuous mode at 512 samples per scan over a range of 70 ns, ~79 scans/m (24 scans/ft), and 64 scans/s. the field acquisition filter was set to a low-pass of 800 mhz and a high-pass of 100 mhz. data processing the processing of the gpr data was complicated by the presence of modern landfill material, the distribution of which was not known prior to the survey, and by the presence of previous archaeological excavations, which had been back-filled. the 2d processing was performed using radan™ software in which geometry assignment, surface correction, background (direct wave) removal, deconvolution, and constantvelocity migration were performed. the background removal was performed using a horizontal boxcar filter based on a 500-trace width. a predictive deconvolution using an operator length of 31 ns, and prediction lag of 5 ns, and a 10% pre-whitening noise addition was then applied. the purpose of this step was to help eliminate the effects of short-period multiple arrivals from interbed echoes and to compress the waveforms. in order to boost weak amplitudes deeper in the section that suffered loss due to spherical spreading or attenuation, a variable automatic gain control was designed using six points along the travel time record. a bandpass frequency filter was applied between 200 and 400 mhz so as to reduce the effect of noise admitted by the broader bandwidth field filter. this application was accompanied by a 9-trace mix (“running sum”), which was aimed at removing low-apparent velocity noise, especially apparent deeper on the records. such noise typically arises in part from random scattering. for this study, we observed a range of dielectric constants based solely on diffraction hyperbolae with typically high values of 9.17 and as low as 4 (fig. 4). the range of velocities of the material overlying the diffraction apices probably reflects the complexity of material, manmade and geologic, at the site. a dielectric constant of 4 corresponds to a velocity of about 0.15 m/ns, while for a dielectric constant of 9.17, the velocity is 0.099 m/ns. near the sw part of the survey, a buried section of pvc pipe was observed in a trench dug as part of this study (to be discussed below) (fig. 3) at a depth of about 0.89 m, that corresponds to a linear gpr anomaly arriving at 21 ns, which yields a velocity of 0.085 m/ns and a dielectric constant of 12.5. the study of rust et al. (1999) of the dielectric constant for dry volcanic rocks gives values as low as about 2 and as high as about 18. russell & stasiuk (1997) measured a dielectric constant of 9 for a holocene pyroclastic flow in canada. in order to remove the effect of diffractions and correctly position dipping events, we applied a kirchhoff migration with a velocity (0.1 m/ns) corresponding to a dielectric constant of 9, which is within the middle of the range, and broadly consistent with the diffraction modeling, expectations for volcanic ash, and the dry conditions observed at the site. the travel times for the vertical views and the time slices can be converted to depth for a particular velocity assumption. for example, for a dielectric of 12.5, divide the travel time by 2 and multiple by 0.085 to obtain depth in meters. gpr data visualization following the 2d processing, the profiles were arranged into a grid and the amplitudes interpolated between lines to produce a pseudo-3d volume which could be viewed simultaneously as depth slices (maps) and vertical views (cross sections) using conventional 3d viewers as typically supplied by gpr software vendors. in order to provide an alternative viewing strategy, the profiles were next converted into seg-y format and imported into a suite of petroleum exploration industry visualization and post-stack processing software (seisworks3d™ and geoprobe™, halliburton). the profiles 82-152 were imported as “lines” and the individual traces within each profile constituted “traces” 1-1917, using the usual terminology for 3d seismic data processing. in this way, we were able to take advantage of a suite of seismic attribute and other volume processing strategies, usually reserved for exploring for underground petroleum reservoirs. we employed both mapbased volume visualization and volume rendering techniques (ma & rokne, 2004). the former involves generation of traveltime-slices and surfaces mapped from subsurface reflectors and the latter dividing the volume into 3d data elements (“voxels”) that can be assigned a value from a particular mathematical process (e.g., semblance) performed across the entire data volume. volume rendering techniques take advantage of applying varying levels of transparency to the data and thus allow viewing more than one attribute of the data simultaneously. for more background on 3d volume visualization the reader is referred to ma & rokne (2004). conventional views a conventional vertical view cutting across the upper, nw part of the survey area shows a stratigraphisubsurface visualization using ... 44 figure 4 two vertical views (profiles) excerpted from the gpr data set (unmigrated) showing examples of diffractions (circles) used for estimating bulk velocity of the medium above the diffractor. (a) the diffraction collapses optimally for a migration velocity of about 0.15 m/ns, corresponding to a dielectric constant of 4. (b) the diffraction collapses optimally for a migration velocity of about 0.099 m/ns, corresponding to a dielectric constant of 9.17. due sezioni verticali (profili), estratte dai dati gpr (non migrati), mostrano esempi di diffrazioni (circoli) usati per stimare la velocità del mezzo a tetto del diffrattore. (a) la diffrazione è corretta in modo ottimale per una velocità di migrazione di circa 0,15 m/ns, che corrisponde ad una costante dielettrica di 4. (b) la diffrazione è corretta in modo ottimale per una velocità di migrazione di circa 0,099 m/ns, che corrisponde ad una costante dielettrica di 9,17. j.h. mcbride et al. 45 figure 5 (a) top, conventional vertical view for profile 142 (see fig. 6 for location). lighter gray represents positive amplitudes, darker gray negative. “1” and “2” refer to layering observed in the gpr vertical views (fig. 5). bottom, vertical view extracted from the discontinuity attribute volume along the same line of profile. (b) same as above, but for profile 113. (c) same as above, but for profile 82. vertical arrows indicate locations of abrupt lateral reflectivity terminations. a) in alto, profilo verticale convenzionale del profilo 142 (vedi fig. 6 per la localizzazione). il grigio chiaro rappresenta ampiezze positive, il grigio scuro negative. ‘1’ e ‘2’ si riferiscono alla stratificazione osservata nelle sezioni verticali del gpr (fig. 5). in basso, sezione verticale estratta dalla discontinuità del volume attribuito lungo la stessa linea di profilo. (b) come sopra, ma per il profilo 113. (c) come sopra, ma per il profilo 82. le frecce verticali indicano il luogo della brusca terminazione di riflettività laterale. cally well-layered reflective sequence underlain by a boundary reflection that arrives at about 37 ns on the sw end of the profile (142, fig. 5a) and rises up to 23 ns on the ne end. a second such profile across the approximate center of the survey area (113, fig. 5b) shows the same reflective sequence over most of the sw part of the profile, but with abrupt lateral cessations of reflections and intervening zones of poor or chaotic reflectivity. lastly, a profile through the se part of the survey area (82, fig. 5c) depicts a return to a well-stratified reflective sequence beginning on the ne end until about three quarters along the profile where again an abrupt lateral truncation of reflectivity appears. in general, two sequences of reflectivity are observed, an upper sequence from about 1 ns to 9 ns, followed by a deeper and thicker sequence from 10 ns to 31 ns (fig. 5). we have created a conventional time slice view centered at 20 ns travel time with a vertical width of ~11 ns subsurface visualization using ... (or ~1 m and width of ~0.5 m for a dielectric constant of ~9.2) over which all the amplitudes are displayed with a median filter for horizontal smoothing (fig. 6). the broad width of the display zone shows the normalized (by the average amplitude) maximum amplitude for all samples in the “slice”. the broad width was necessary to detect the subtle boundaries and edges as noted by arrows (fig. 6), although this significantly decreases the depth resolution of the image since the display is combining information from a range of depths. if we compare the three vertical views (fig. 5) with the conventional travel time slice (fig. 6), we can see that the disruptions on the vertical views correspond to boundaries between groups of positive and negative amplitude. negative amplitude areas on the time slice (dark gray in fig. 6) tend to correspond to low reflection coherency while positive amplitudes (light gray) usually correspond to higher coherency. several linear and rectangular elements appear on the time slice. here we discuss only the most obvious features, which are (1) the linear, nw-se-trending boundary separating a reflective and an unreflective region to the ne and sw, respectively; and (2) an approximately square feature of low reflectivity near the eastern corner of the study area. these two features, together with the internal reflectivity of the stratigraphically layered sequence, are the focus of advanced seismic attribute and other visualization discussed next. advanced views based on seismic attribute and other strategies discontinuity attribute. because the gpr features of interest in this study appear to be defined by terminations in reflectivity, we first applied a seismic discontinuity detection attribute to the data volume. many different types of discontinuity attribute processes have been developed (e.g., bahorich & farmer, 1995), but all basically seek to quantify the degree to which adjacent waveforms differ between traces. abrupt lateral changes in waveform character that could be due to geological discontinuities (e.g., faults, stratigraphic terminations) are enhanced by this attribute. the technique applied here uses a weighted correlation to establish similarity between two traces based on a moving window that is parameterized according to the number of profile lines, number of traces, and a travel-time gate. for our study, we used a relatively wide spatial and time window (11, 11, 5 samples or ~0.7 ns), which enhanced profile views (fig. 5, bottom sections), producing much cleaner images, but sacrificing some detail due to averaging in the window. the attribute is applied to the entire volume and then vertical views are extracted (fig. 5, bottom sections) and shown along with the three conventional views (fig. 5, top sections) as discussed above. the resulting profiles much more clearly show the positions of lateral reflector terminations as well as show regions of higher coherency, including the two general sequences of reflectivity referred to in the previous section. the terminations tend to affect the volume beginning at a fairly shallow level and continue deeper along a straight vertical line of discontinuity. 3d volume rendering. the 3d volume attribute computations used only one profile direction, ne-sw, and included 71 profiles (~0.3-m (1-ft) spacing), between which amplitudes were interpolated. the first visualization employed (fig. 7) a volume rendering whereby all voxels inside a volume ranging from 18 ns to 24 46 figure 6 conventional time slice using a travel time interval of ~11 ns centered over 20 ns. lighter gray represents positive amplitudes, darker gray negative. arrows indicate boundaries or areas of interest, discussed in the text. compare this and other map views with fig. 1 for orientation and relation to surface features. the locations of the profiles shown in figure 5 are indicated. mappa di tempo convenzionale prodotta usando un intervallo di tempo di percorrenza di circa 11ns centrati su 20 ns. il grigio chiaro rappresenta le ampiezze positive, il grigio scuro le negative . le frecce indicano i confini delle aree di interesse, discusse nel testo. comparare questa e le altre mappe con la figura 1 per l’orientazione e la relazione con le caratteristiche superficiali. sono indicate le localizzazioni dei profili mostrati in figura 5. j.h. mcbride et al. ns are displayed simultaneously as if the space were semi-transparent (castanie et al., 2005). by rendering a volume semi-transparent it is possible to “see” anomalies from a range of travel times (depths) together in such a way that anomalies that remain consistent with depth are emphasized (or “stacked”) and can be projected onto a map view (fig. 7). in the volume rendering shown in figure 7, only the highest positive amplitudes are mapped to black (or opaque within the volume; other amplitudes are mapped to zero or transparent), which emphasizes linear boundaries where amplitude abruptly decreases. however, this strategy mixes amplitudes in the display from a range of travel times, analogous to the conventional display in figure 6, discussed in the previous section. the volume rendering displays several linear and rectilinear elements. near the sw corner of the study area, three parallel nw-se-trending linear elements can be recognized (fig. 7). one of these linear anomalies corresponds to the buried pipe (fig. 3), as discussed above, while the northeasternmost linear anomaly corresponds to a boundary between coherent and poorly coherent reflectivity (from ne to sw, respectively). looking further to the ne, the outline of the approximate square can be easily seen (fig. 7). the boundaries of the square are sharply delineated, suggesting that, since the 3d attribute represents a volume ranging from 18 ns to 24 ns, the sides of the square continue up and down as vertical edges surrounding a mostly incoherent region. this is also indicated by the enhanced vertical views that cut through the square (fig. 5, bottom sections). the appearance of amplitudes (black color) within the square imply the presence of coherent features somewhere within the volume subset defined by the square in 2d. 3d semblance attribute. the semblance attribute (e.g., neidell & taner, 1971) computes a new 3d volume using the similarity of each trace with three neighboring traces with a travel time window length of 48 samples (about 6.6 ns). the relatively long window reduces noise, but may be smearing discontinuities. like the discontinuity tool discussed above, semblance can highlight boundaries related to sudden changes in geological structure (or, in our case, shallow soils and sediments). the results of the computation (fig. 8) indicate an area of low semblance (white in fig. 8) within the square area and within the sw corner of the survey area. the semblance display is somewhat similar to the volume rendering except that the former represents one travel time (in this case, 8 or 18 ns, figs. 8a and 8b, respectively), whereas the latter gathers information from 18 ns to 24 ns, and is thus less precise. the shallow time slice (fig. 8a), which slices through the shallow reflective sequence, shows a comparable expression of low similarity within the square area compared to the previous attribute (cf. figs. 8a and 7), although the edges of the square, especially on the western corner, are less distinct. however, the deeper slice (fig. 8b) indicates a distinct linear element cutting across the sw corner of the survey area. this feature would not be as recognizable from the volume rendering alone (fig. 7). on the other hand, the shallower slice (fig. 8a) shows a narrow band of high coherency just around the nw corner of the square area that is not so apparent on the deeper slice (fig. 8b). the semblance attribute is thus able to extract relatively minute details from the volume at just one time slice, whereas transparent volume renderings (figs. 6 and 7) are averaging information over a range of travel time (i.e., depth). 3d arc length attribute. arc length is a measure of the total excursion of the trace wiggle over a specified travel t ime window length ( in this case, about 2 ns). arc length can be described as a hybrid attribute that combines amplitude and frequency components and is proportional to amplitude, and higher values of arc length represent higher reflectivity (black in fig. 9) 47 figure 7 volume rendering of highest amplitudes for travel time interval of 18 ns to 24 ns. white represents negative amplitudes, black positive amplitudes. faint horizontal striping is an artifact of the data acquisition. restituzione del volume per le ampiezze maggiori per tempi di percorrenza da 18 ns a 24 ns. il bianco rappresenta ampiezze negative, il nero ampiezze positive. le deboli strisce orizzontali sono un artefatto dell’acquisizione dati. subsurface visualization using ... (schultz et al ., 1994; rana et al., 2006). qualitatively, arc length is similar to reflection strength. using the arc length attribute can increase the precision of the processed image because it depends on the phase of the waveform and thus may avoid the smearing of amplitudes due to interference and phase changes (rana et al., 2006). the results for 12 ns (fig. 9a) show a distinctive border of low arc length that defines the square area, which itself is composed of mixed high and low values. this mixed amplitude behavior can be compared with other areas of more consistently high (black) and low (white) arc length as seen, for example, in two north-south-t rending bands of high and low arc length in the sw part of the survey area. at a time slice of 21 ns (fig. 9b), the square anomaly is not well delineated; however, it is now possible with this attribute to isolate in depth the anomaly caused by a pipe as seen in the volume rendering (fig. 7). as applied to this data set, the arc length processor is useful for detailed delineation of subtle boundaries. c o n n e c t i v i t y attribute. an attribute has been developed based the 6-way connectivity between adjacent voxels in the volume. an anomaly will be identif ied and plotted when at least one face of the voxel is connected to a neighboring voxel (see zhou (1993) and gao (2007) for examples). connectivity has been used to produce a texture-based classification of a volume (gao, 2007) that can then be used to delineate or map geological or soil features that 48 figure 8 (a) map of semblance attribute for 8 ns, computed with a window length of 48 samples (about 6.6 ns), and a 3-trace sampling pattern. low semblance is represented by white, high semblance by black. (b) same as above, but for travel time of 18 ns. (a) mappa di ‘semblance attribute’ (vedi testo) per 8 ns, calcolata con una finestra di 48 campioni (circa 6,6 ns), e un campionamento a tre tracce. la basso valore di semblance è rappresentata dal bianco, l’alta dal nero. (b) come sopra, ma per tempi di percorrenza di 18 ns. j.h. mcbride et al. have similar waveform properties in both lateral and vertical dimensions, such as continuous layers of volcanic ash or other sediment. this type of attribute has been used to map potential petroleum reservoirs (gao, 2007). for this study, we have applied 3d connectivity to the two reflective sequences discussed previously (fig. 5) as well as to the entire volume. in order to demonstrate how this attribute works, we show connectivity anomalies from the lower reflectivity sequence (fig. 5) in a perspective “workstation-style” view that visually integrates profiles and maps (fig. 10). as can be seen from figure 10, the map anomalies correlate with individual reflections and terminate at the edges of reflectors. we thus infer that the anomalies are generally responding to lateral stratigraphic coherency. the two anomalous areas of low semblance, amplitude, and coherency that we have been examining affect mainly the lower reflectivity sequence (fig. 5). computing connectivity within just this lower sequence indicates abrupt cessations in connectivity that define the edges of the square area on the ne part of the survey area and the roughly triangular area in the sw part of the survey as seen in perspective view (fig. 10). the linearity of the connectivity terminations is easy to see in a flat map in which all connectivity anomalies from the lower sequence are displayed simultaneously (fig. 11b). showing, in identical format, only the anomalies from the upper reflectivity sequence (fig. 11a) does not show any obvious linear 49 figure 9 (a) arc length time slice, computed with a window length of 15 samples (about 2 ns) at 12 ns. higher values of arc length are shown as black and are proportional to higher reflectivity. (b) same as above, but for a travel time of 21 ns. (a) mappa di ‘arc length time’ (vedi testo) calcolato con una finestra di 15 campioni (circa 2 ns) a 12 ns. valori più alti della ‘arc length’ sono rappresentati in nero e sono proporzionali alla maggiore riflettività. (b) come sopra, ma con tempi di percorrenza di 21 ns. subsurface visualization using ... termination trends, which suggests that this sequence is less affected by the phenomenon (i.e., ground disruption) causing the changes in deeper reflections. conclusion the landfill material and the presumed presence of previous archaeological excavations, which had been back-filled, combine to exacerbate the usual non-uniqueness of a geophysical interpretation of the subsurface. although it was known that previous excavations and other disturbances of the ground had taken place, we did not know their exact locations. the results of 3d processing reveals distinct linear elements in map view that might be related to buried structures, back-filled excavations, or possibly to irregularities in the volcanic layering that f i l ls and covers the site. we fortuitously were able to obtain an aerial photograph of the site that was apparently taken several years before our work commenced, but after previous workings (archaeological and otherwise) at the site. figure 1 shows a rendering from this photograph, along with the boundary of the gpr survey area superimposed. one may clearly see a square area defined by vegetation and bare ground in the interior of the square; and a nw-se-trending boundary defined by vegetation to the sw and bare ground to the ne (fig. 1). a map presented by pagano (1992) indicates an excavation, which was made in the 1980s, in what appears to be about the same place as the square area on the photograph drawing and the square anomaly on the gpr map (time slice) images. we thus interpret the square area as being the site of a previous archaeological excavation (or possibly other disturbance of the ground), which was later back-filled and is represented on aerial photographs as a disturbed ground surface surrounded by low vegetation. the meaning of the line of vegetation cutting across the sw corner of the survey area is less clear, but appears to be the remains of an access road or filled trench. the effect of these two surface features, which were obliterated by the time of our 2007 survey, dominate the gpr data, especially in map (time slice) view. the 3d visualizations thus reveal features that are related to previous, modern archaeological excavations or other disturbances of the ground. these features are expressed as strongly linear and/or rectilinear elements in the vertical views and time slices through the volume. the linear elements are expressed in vertical views as lateral disruptions of volcanic depositional layering, which is itself well expressed as sub-horizontal to wavy reflectivity. on the time slices, these lateral disruptions are evident as straight-line boundaries, which attest to their man-made origin. other, less-well expressed linear elements may be related to archaeological features of interest, which would require confirmation by test-trenching. the effect of previous disturbance or excavation of the ground is so well expressed on the gpr images due in part to the low attenuation of the volcanic sediment sequences and the sharp lateral truncations of these sequences. the volcanic layering is well charac50 figure 10 perspective (“workstation-style”) view of connectivity anomalies from the deeper interval (interval 2 shown in fig. 5a), interpreted as being mainly volcanic ash layers. the vertical view is extracted from the discontinuity volume (as shown in the vertical views depicted in the lower parts of figures 5a, 5b, and 5c). the base of the second volcanic layer (fig. 5) is shown as a gray-level surface. the connectivity anomalies are expressed as patterns above the surface and were computed with an imposed minimum size limit of 1000 voxels (i.e., the minimum number of voxels required to define the anomaly). visione prospettica delle anomalie di connettività dall’intervallo più profondo (l'intervallo 2 è mostrato in fig. 5a), interpretate come dovute principalmente a livelli di cenere vulcanica. la sezione verticale è estratta dal volume di discontinuità (vedi testo) (come si mostra nelle viste verticali presenti nelle sezioni alla base delle figure 5a, 5b, 5c). la base del secondo livello vulcanico (fig. 5) è mostrata come una superficie grigia. le anomalie di connettività sono espresse come andamenti al di sopra della superficie ed sono calcolate con un limite di grandezza imposto di 1000 voxels. j.h. mcbride et al. terized by the gpr data, as shown by the connectivity attribute. the discontinuity attribute responds well to imaging terminations within this layering. the arc length attribute responds particularly well to defining individual boundaries such as the se edge of the square anomaly. the semblance attribute shows less precision than arc length. the volume rendering (18 ns to 24 ns) appears to show a high degree of precision, but this is partly an artifact of stacking anomalies from different depths onto on time slice view. we demonstrate that gpr visualization can be effectively used for detecting subtle disturbances of volcanic soils. the precision of the visualization is improved with the application of processes designed for 3d seismic attribute processing, such as arc length, semblance, discontinuity, and connectivity attributes. from the several visualization examples presented herein, it should be clear that no single attribute will be appropriate for all targets. for example, the volume rendering (fig. 7) reveals a feature as small as a pipe (fig. 3) and the arc length can isolate it to 21 ns (fig. 9); on the other hand, the semblance attribute (fig. 8) is better for delineating bulk changes in reflectivity character, but may not be effective for small individual objects like a pipe. the visualization results will be used to guide future excavation at the site. the radar attribute images will provide constraints on interpreting the information revealed by future excavation and wil l also provide a shallow geological context 51 figure 11 (a) volume-rendered time slice of connectivity anomalies corresponding to the upper reflectivity sequence (fig. 5), 1-9 ns. (b) same as above, but for lower reflectivity sequence (fig. 5), 1031 ns. (a) rappresentazione volumetrica delle anomalie di connettività corrispondenti alla sequenza di riflettività superiore (fig. 5), 1-9 ns. (b) come sopra, ma per la sequenza di riflettività inferiore (fig. 5), 10-31 ns. subsurface visualization using ... for understanding the physical character of the eruptive material that has covered the site episodically for the past two millennia. acknowledgments the authors gratefully acknowledge software grants from the landmark (halliburton) university grant program (geoprobe™, seisworks3d™, and promax2d™). partial financial support for this project was provided by a mentoring environment grant from brigham young university. the authors express their appreciation to the two journal reviewers for their useful and constructive comments. references bahorich m., & farme s. (1995) 3-d seismic discontinuity for faults and stratigraphic features: the coherence cube, the leading edge, v. 14, p. 1053-1058. castanie l., bosquet f., & levy b. (2005) advances in seismic interpretation using new volume visualization techniques, first break, v. 23, p. 69-72. conyers l. b. (2004) ground-penetrating radar for archaeology, altamira press, 203 pp. conyers l. b. (2007) ground-penetrating radar for archaeological mapping, in wiseman j. & el-baz f. (editors), remote sensing in archaeology, springer, p. 329-344. de simone a., scarpati c., macfarlane r. t., de simone g. f., keith j., perrotta a. , & mcbride j. (2007) eruptions and settlements on vesuvius’ northern slope: the apolline project, international congress people/environment relationships from the mesolithic to the middle ages: recent geoarchaeological findings in southern italy, salerno, italy, sept. 4-7, 2007. de simone g. f. (2007) oltre la costa: il problema delle ville nell’entroterra vesuviano, in ciardiello r. (editor), la villa romana, orientale editrice, p. 241-55. gao d. (2007) application of three-dimensional seismic texture analysis with special reference to deep-marine facies discrimination and interpretation: offshore angola, west africa, aapg bulletin, v. 91, p. 1665–1683. goodman d., schneider k., piro s., nishimura y., & pantel a. g. (2007) ground penetrating radar advances in subsurface imaging for archaeology, in wiseman j. & el-baz f. (editors), remote sensing in archaeology, springer, p. 375-394. ma c., & rokne j. (2004) 3d seismic volume visualization, in zhang d. d., kame, m., baciu g., editors, integrated image and graphics technologies, the springer international series in engineering and computer science, springer netherlands, v. 762, p. 241-262. neidell n. s., & taner m. t. (1971) semblance and other coherency measures for multichannel data, geophysics, v. 36, p.482-497. pagano m. (1992) pollena trocchia: scavo in località masseria de carolis e ricognizioni nel territorio comunale , rivista di studi pompeiani 5 (1991/1992), p. 231-36. perrotta a., scarpati c., luongo g., & aoyagi m. (2006a) burial of emperor augustus' villa at somma vesuviana (italy) by post-79 ad vesuvius eruptions and reworked (lahars and stream flow) deposits. journal of volcanology and geothermal research, v.158, p. 445-466. perrotta a., scarpati c., & luongo g. (2006b) volcaniclastic resedimentation on the northern slope of vesuvius as a direct response to eruptive activity. landslides, v. 3, p 295-301 russell j. k., & stasiuk m. v. (1997) characterization of volcanic deposits with ground-penetrating radar, bulletin of volcanology, v. 58, p. 515–527. russell j. k., & stasiuk m. v. (2000) ground-penetrating radar mapping of minoan volcanic deposits and the late bronze age palaeotopography, thera, greece, in mcguire w. j., griffiths d. r., hancock p. l., & stewart i. s., editors, geological society special publications, v. 171, p. 105-121. rana s., burley s., & chowdhury s. (2006) the application of hierarchical seismic attribute combination to high precision infill well planning in the south tapti field, offshore western india, geohorizons, january, p. 32-37. rust a. c., russell j. k., knight r. j. (1999) dielectric constant as a predictor of porosity in dry volcanic rocks, journal of volcanology and geothermal research, v. 91, p. 79–96. santacroce r. (1987) somma-vesuvius. c.n.r. quad. ric. sc. 114/8, p. 1-251. schultz p.s., ronen s., hattori m., corbett c. (1994) seismic-guided estimation of log properties, part 1: a data-driven interpretation methodology, the leading edge, may, p. 305-311. sheets p. d. (2005) the ceren site: a prehistoric village buried by volcanic ash in central america, wadsworth publishing, 168 p. sulpizio r., mele d., dellino p. & la volpe l. (2007) deposits and physical properties of pyroclastic density currents during complex subplinian eruptions; the ad 475 (pollena) eruption of sommavesuvius, italy, sedimentology, vol. 54, p. 607635. zhou h-w. (1993) traveltime tomography with a spatial-coherency filter, geophysics, v. 58, p. 720726. 52 ms. ricevuto il 23 settembre 2008 testo definitivo ricevuto l’8 aprile 2009 ms. received: september 23, 2008 final text received: april 8, 2009 j.h. mcbride et al. << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /none /binding /left /calgrayprofile (dot gain 20%) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /error /compatibilitylevel 1.4 /compressobjects /tags /compresspages true /convertimagestoindexed true /passthroughjpegimages true /createjdffile false /createjobticket false /defaultrenderingintent /default /detectblends true /colorconversionstrategy /leavecolorunchanged /dothumbnails false /embedallfonts true /embedjoboptions true /dscreportinglevel 0 /emitdscwarnings false /endpage -1 /imagememory 1048576 /lockdistillerparams false 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<feff4f7f75288fd94e9b8bbe7f6e521b5efa76840020005000440046002065876863ff0c5c065305542b66f49ad8768456fe50cf52068fa87387ff0c4ee575284e8e9ad88d2891cf76845370524d6253537030028be5002000500044004600206587686353ef4ee54f7f752800200020004100630072006f00620061007400204e0e002000520065006100640065007200200035002e00300020548c66f49ad87248672c62535f0030028fd94e9b8bbe7f6e89816c425d4c51655b574f533002> /cht <feff4f7f752890194e9b8a2d5b9a5efa7acb76840020005000440046002065874ef65305542b8f039ad876845f7150cf89e367905ea6ff0c9069752865bc9ad854c18cea76845370524d521753703002005000440046002065874ef653ef4ee54f7f75280020004100630072006f0062006100740020548c002000520065006100640065007200200035002e0030002053ca66f465b07248672c4f86958b555f300290194e9b8a2d5b9a89816c425d4c51655b57578b3002> >> >> setdistillerparams << /hwresolution [2400 2400] /pagesize [595.000 842.000] >> setpagedevice imp.ruberti& inventory of the geopalaeontological heritage in protected areas of the campania apennines daniela ruberti1°, marco vigliotti1, giuseppe sirna2 & maurizio muselli1 1dipartimento di scienze ambientali, seconda università degli studi di napoli (caserta). e-mail: daniela.ruberti@unina2.it 2via primo acciaresi, 15 – 00157 roma ° “centro regionale di competenza per lo sviluppo ed il trasferimento dell’innovazione applicata ai beni culturali ed ambientali”, u.o. 2 (sviluppo ed applicazioni di metodologie e tecnologie scientifiche avanzate per lo studio ed il monitoraggio dei beni culturali e ambientali), wp 2.4 (laboratorio integrato per il monitoraggio della qualità ambientale) abstract: d. ruberti et al., inventory of the geopalaeontological heritage in protected areas of the campania apennines. (it issn 0394-3356, 2005). goal of the present paper is to select important geopaleontological sites in protected areas of the campania apennines by constructing a geosites database. in particular, following research activities focused on cretaceous rudist benthic communities, areas where fossiliferous horizons occur rich in rudists have been selected. these organisms were widespread in shallow marine settings during the cretaceous time and become extinct at the end of that period. the wide distribution of the rudists during the cretaceous makes them an usefull key to evaluate the paleoecological and sedimentary conditions of the environments they colonized. their study may provide interesting qualitative insight in palaeoecological dynamics of carbonate platforms. geopalaeontological sites from protected areas of the campania apennines have been recognized and listed in order to promote the knowledge of the geological history of these regions not only among specialists. a computerised database of the selected geopaleontological sites has been created on the base of the italian geological survey indications. tabeled data have been imported in a gis project that also contain the administrative boundaries and the limits of regional/national parks and protected areas. other tematic database can be linked to the gis project. such a recognition and inventory may offer a way to make use of such an heritage through naturalistic routes that evidence the geological history of a region. riassunto: d. ruberti et al., censimento del patrimonio geopaleontologico nelle aree protette dell’appennino campano. (it issn 0394-3356, 2005). scopo del presente lavoro è quello di selezionare importanti siti geopaleontologici in aree protette degli appennini campani attraverso la costruzione di un database dei geositi. in particolare sono state selezionate, sulla base delle attività di ricerca sulle comunità bentoniche delle rudiste del cretaceo, aree con orizzonti fossiliferi ricchi in rudiste. questi organismi erano abbandonati nei fondali marini bassi durante il cretaceo e si estinsero alla fine di questo periodo. l’ampia distribuzione di rudiste durante il cretaceo le rende un utile strumento per valutare le condizioni paleoecologiche e sedimentarie degli ambienti che hanno colonizzato. il loro studio può fornire interessanti indicazioni delle dinamiche paleoecologiche delle piattaforme carbonatiche. sono stati riconosciuti ed elencati siti geopaleontologici di aree protette dell’appennino campano con lo scopo di diffondere la conoscenza della storia geologica di queste regioni anche in un pubblico di non specialisti. sulla base delle indicazioni del servizio geologico nazionale si poi è proceduto alla creazione di un database dei siti geopaleontologici selezionati. i dati raccolti nel database sono stati inseriti in un gis, contente anche i confini amministrativi e i confini dei parchi nazionali, regionali e delle aree protette. altri database tematici possono essere collegati al gis. questo censimento può rappresentare un valido strumento di valorizzazione di questo ricco patrimonio attraverso sentieri naturalistici che mettano in evidenza la storia geologica della regione. keywords: geopalaeontological sites; cretaceous; rudists; southern apennines. parole chiave: siti geopaleontologici, cretaceo, rudiste, appennino meridionale. il quaternario italian journal of quaternary sciences 18(1), 2005 volume speciale, 125-136 1. introduction carbonate deposits, that form most of the central-southern apennines, testify to a long and complex geological history. moreover, since carbonates are the direct result of biosphere metabolism, it is important to understand the role played by the biosphere in controlling sedimentation and evolution of carbonate bodies. the genesis and evolution of the latter thus represent the key to recognize changes in climate, oceanic circulation, relative sea level changes, etc., that have affected the development of depositional systems and the delicate biological equilibria of benthic communities, considered as primary carbonate sediment-producers. cretaceous deposits, widespread in the centralsouthern apennines, are particularly interesting. in general, they appear to have originated in shallow water marine environments in which benthic communities (mostly composed by molluscs – bivalves and gastropods – benthic foraminifers, bryozoans and red algae) settled. their study has been fundamental in reconstructing shortand long-term environmental changes (cf. carannante et al., 1995; 1997; 1999; ruberti, 1997; simone et al., 2003, and references therein) and still 126 d. ruberti et al. involves international research groups. among the benthic communities, in particular, rudists (a group of invertebrate metazoa) represent an interesting and complex case history. these organisms, which appeared at the end of the jurassic and lived till the end of the cretaceous, were found throughout the shallow water environments of the old tethys ocean, from its inner shelf to marginal environments. their rapid evolution, as well as their great species diversity, makes them good stratigraphic markers for the cretaceous and a valuable tool to evaluate the paleoecological and sedimentary conditions of the environments they colonized and the factors that controlled their evolution and extinction. at this regard, within the international union on geological sciences (iugs), the cretaceous research working group 4 (crer wg4) and the international research group on rudists have promoted interesting international activities (conferences, scientific volumes, field seminars) focused on cretaceous bioconstructions through time and space (simo et al., 1993; cestari & sartorio, 1995; masse et al., 1995; proceedings of the 2nd, 3rd, 4th, 5th, 6th intern. conference on rudists) in order to provide qualitative insight in palaeoecological dynamics of carbonate platforms. this kind of study has highlighted very descriptive, spectacular, well exposed outcrops, which are wellsuited to becoming geopalaeontological sites of natural interest. in recent years, national institutions (i.e. national geological survey, enea), local administrations, international associations (iugs, progeo) and earth science societies have started to promote geological culture outside the usual specialists. a proposal of a geosite inventory has been proposed to the international earth science communities, especially since the birth of progeo italia, with a view to selecting an international list of the most important sites for geological sciences and identifying what is special and representative in the geology of each country (cf. praturlon, 1996; wimbledon et al., 1996; brancucci et al., 1999; wimbledon, 1999; d’andrea, 2000). it is thus particularly important that public administration converges with the world of geological and environmental research to ensure an increasingly attentive approach to renewable and non-renewable natural resource management. the latter may also be achieved by protecting sites of particular geo-palaeontological interest in the regions concerned. the aim of the present paper is to select the most important geopalaeontological sites in protected areas of the campania apennines by constructing a geosites database. such a recognition and inventory may open up the possibility of exploiting such resources sustainably by mapping out trails that highlight the geological history of the region. 2. rudists rudists are bivalves with more or less modified shells. they can be divided into two groups: those attached by the right valve (monopleura , caprina, hippurites, radiolites genera, among others) and those attached by the left valve (requienia, toucasia genera). during their evolution, rudists were subjected to major changes as a response to ecological factors (fig. 1; based on sirna & laviano, 1989; sirna, unpublished data; see also cestari & sartorio, 1995). the earliest rudists (diceratidae) were only slightly inequivalve genera, the latter characteristic becoming increasingly pronounced. requieniidae evolved at the beginning of the cretaceous from the diceratiidae and were characterized by an inequivalve left valve, attached to the substratum. the right valve was smaller, opercular. the presence of an external ligament caused an accentuated tangential shell growth and the consequent spirogyrate shell-shape (cestari & sartorio, 1995). the ligament invagination produced the uncoiling and rising from the substratum of the shell, as can be observed in the caprotinidae and caprinidae. the latter had an inequivalve shell that reached also wide dimensions. the right fixed valve was small and conical while the left free one was more developed and markedly spirogyrate. the shells of radiolitidae and hippuritidae changed their architecture gradually, achieving a pipe-like shape with an opercular upper valve. in evolutionary terms, radiolitidae are older than hippuritidae; both reached their peak expansion with marked endemism during the late cretaceous. similarly to other important organisms, these bivalves did not survive the great mass extinction that occurred at the end of the cretaceous. 2.1 palaeoecological aspects among the cretaceous sediment producer organisms, rudists play an important role because they occurred in different depositional environments of the tethys ocean. they spread over the carbonate shelves, from the innermost settings to the outermost sectors of the shelf. their rapid evolution and large number of species make rudists good stratigraphic markers in the whole carribean and mediterranean region (cf. pons & sirna, 1992; cestari & sartorio, 1995; sirna & paris, 1999; proceedings of the 2nd, 3rd, 4th, 5th, 6th intern. conference on rudists; among others). they are known from the gulf of mexico, iberian peninsula, southern france, the italian apennines, apulia, the dinarides, romania, hungary, poland, greece, turkey, syria, the lebanon, and north africa. during the cretaceous, rudists inhabited tropical and subtropical belts of the tethys, including those between north and south america and the indopacific. a few highly specialized taxa (mostly radiolitidae), settled in the temperate zones of southern canada and the british isles. as already stated, rudists preferred the neritic realm, adapting to different kinds of sea bottoms: some genera colonized sandy bottoms, others preferred silty-sandy ones, at least the terrigenous ones. nevertheless, as a rule rudists preferentially inhabited carbonate environments. more generally, the main observation is that from the middle-upper cretaceous, rudists spread over all shelf sectors, from more open and external areas to more internal ones, occupying different substrata and furnishing the bulk of the skeletal component by means of bioerosion processes. they colonized mobile sediments giving rise to complex bodies with peculiar characteristics related to the environmental parameters of the different sectors of the shelf (cf. carannante et al., 2001; simone et al., 2003). 2.2 rudists of the southern apennines during the lower cretaceous, the requienidae and caprotinidae are the best represented. the former preferred sheltered environments, characterized by fine-grained, mainly muddy substrata, such as protected lagoons, and only occasionally they can be found associated with silty-sandy sediments. caprotinidae and caprinidae assemblages are common in higher energy environments, such as open shelves (well known in the matese, southern fucino campoli appennino and monti d’ocre successions). nevertheless, owing to vast and complex geologic events occurred in the late aptian-early senonian time (e.g. changes in climate, oceanographic circulation, sea level, tectonic and volcanic activity), the cretaceous carbonate platforms modified the organization of their depositional system resulting in a drastic facies variation. in particular, during cenomanian time, the eustatic oscillations and tectonic events that interested the periadriatic region induced localized emersions and strong physiographic alterations of the carbonate 127inventory of the geopalaeontological ... platforms. even the carbonate platforms of centralsouthern italy were affected by these events. in their evolution it is possible to recognize crisis period in rudist evolution that started during the albian and that was characterized by a decrease of species, genera and family number. an abrupt inversion of tendence is recorded in the lowermost cenomanian through an adaptative radiation of forms and an increase of the biological diversity mainly in the high energy and/or marginal open areas of the shelf. in the cenomanian time carbonate shelves became more articulated, owing to the complex tectonic and eustatic events that characterized the periadriatic region. in this interval several genera of caprinidae developed, in association with radiolitidae and a few corals, especially in the outermost sectors of the shelf. in more protected settings gastropods (nerineids) and radiolitid assemblages flourished togheter with oysters (chondrodonta) and benthic foraminifers. at the end of the cenomanian, in correspondence of the turonian boundary, a new important crisis phase took place in all shallow-water environments. this one knocked mainly the caprinids, among the rudists, but also nerineans, and only few species of them survived. during the upper turonian-senonian interval, rudists spread over all the shelf sectors, from more fig. 1 – evolution of the main rudist families and their distribution in time (based on cestari & sartorio, 1995, and bosellini, 1991). see text for explanations. evoluzione delle principali famiglie di rudiste e relativa distribuzione nel tempo (modificato da cestari & sartorio, 1995, bosellini, 1991). per ulteriori spiegazioni si veda il testo. 128 open and external areas to more internal ones, occupying different substrata and furnishing the bulk of the skeletal component. rudists grew in loose sediments giving rise to limited and scattered rudist-rich bodies. stormand wind-induced currents and waves repeatedly mobilized the rudist-supporting loose sediments; as a consequence toppled shells are very abundant and only in the more internal and protected shelf sectors, the growth-related arrangement of the rudistshells can be easily observed (cf. carannante et al., 1993; 1997; simone et al., 2003). 3. inventory of the geopalaeontological heritage 3.1 identification and inventory of sites of palaeontological importance rudist-bearing cretaceous successions cropping out in the southern apennines have been intensively studied in recent years (cf. § 1) on the basis of research projects dealing with the environmental reconstruction of the cretaceous carbonate platforms and the recognition of the factors influencing growth and development of the biotic communities, primary sediment producers (cf. simone et al., 2003, for a review). particularly interesting, spectacular geopalaeontological sites have been recognized, that can be proposed for preservation. some sites lie within protected areas of campania. two sites are illustrated herein, located in the widest protected areas of the campania region: the matese and cilento mountains (fig. 2). the main purpose is to evidence the geopalaeontological aspects of international importance and make them known through a computerized inventory in order to include the sites along specific nature trails. 3.1.1 regional park of matese the matese mountains represent the eastern part of the southern apennines and straddle the provinces of benevento, isernia, campobasso and caserta. the matese mountain range morphologically forms one of the main axial culminations of the southern apennines (fraissinet & la valva, 2001). it derives from the deformation of a palaeogeographic domain characterized by a carbonate sedimentation from the triassic to the lower miocene, with local and sometimes large stratigraphic gaps. the sedimentary model for the mesozoic is a carbonate platform with scarps of variable inclination and height that came into existence in the upper trias and was deformed by the late miocene tectogenetic events and dissected by plio-pleistocene tectonics. the main outcrops concern the mesozoiccenozoic shallow water-to-slope carbonate platform domain pertaining to the southern tethys. the outcrops relative to transitional facies between these two domains are poorly defined, with no physical continuity and are strongly tectonized. rich and interesting fossiliferous “horizons” are found throughout the mountains, culminating in the real “subaerial museum” of pietraroia. they offer an interesting record of the meso-cenozoic marine life and environments. cretaceous deposits appear particularly interesting: they record the events that characterized the periadriatic region in that period (d'argenio, 1974; channel et al., 1979; d'argenio et al., 1980; radoicic, 1987; accordi & carbone, 1988; cocco & d'argenio, 1988; carannante et al., 1991; d'argenio & mindszenty, 1992; carannante et al., 1994) and show remarkable facies differences in various matese sectors. shallow water deposits characterize the whole cretaceous eastern matese successions, while in the western area late cretaceous margin-to-slope bioclastic limestones d. ruberti et al. fig. 2 – location map of the proposed gepaleontological sites. a) serra delle macchietelle hill, in the regional park of the matese mounts. b) trentinara outcrop in the national park of cilento and vallo di diano. igm topographic map 1:50000, sheet 405, 487, 503. ubicazione dei siti geopaleontologici proposti per la tutela. a) dorsale di serra delle macchietelle, nel parco regionale del matese. b) affioramento di trentinara, nel parco nazionale del cilento e vallo di diano. basi topografiche igm, in scala 1:50000, fogli 405, 487, 503. 129 (better known in the literature as "calcari pseudosaccaroidi bianchi" or "calcari cristallini” selli, 1958; pescatore, 1964; 1965; ietto, 1970; accordi et al., 1982) can be recognized resting on triassic-jurassic shallow water limestones. stratigraphic analysis carried out in this region led to identify in the eastern area the source of sediments accumulating in the western area. the sector proposed for protection comprises the central part of the matese mounts, around the lake of matese, on the southern flanks of m. miletto. this area is characterized by mesozoic shallow-water limestones. cretaceous limestones are well exposed, characterized by large occurrence of rudist facies that represent highly didactic successions, both for scientific and naturalistic/touristic purpose (accordi at al., 1990; ruberti, 1991; carannante et al., 1993; 1997). 3.1.2 national park of cilento and vallo di diano the national park of cilento and vallo di diano is the second largest national park in italy (181,048 ha) and represents one of the largest biogeographic complexes in southern italy. its geographical position, the coasts, the rivers, and the mountains have resulted in a variety of environments. geologically, the area is characterized by limestone mountains in the eastern part, with the alburni range and mt. cervati, and arenaceous reliefs in the western part (mt. stella, mt. sacro, mt. centaurino); the southwestern part is once again limestone (mt. bulgheria). by a geomorphological point of view, the cilento park consists of both smooth hills and high mountains. long, deep valleys cut the mountain flanks; the rivers running over them gave rise to wide and smooth alluvial areas. moreover the cilento has the most extensive karstic system in the southern apennines. by a geopalaeontological point of view, the limestones cropping out in this area offer rich and interesting fossiliferous “horizons” that document mesocenozoic marine and fresh-water life and environments. the sector proposed for protection comprises the mt. soprano-mt. vesole structures and the monti alburni. this area has outcrops of great importance for geopalaeontological studies, which testify to the geological history of the region. the mt. soprano-mt. sottano ridge is a 20 km nw-se belt that crops out south of the sele plain and represents the northern margin of the cilento mountains (cestari, 1971; sgrosso, 1968). this structure may be considered part of a wide anticline pertaining to the stratigraphic-structural unit of alburno-cervati (scandone, 1967; sgrosso, 1968; d’argenio et al., 1973). mesozoic lithologies cropping out in the studied area mainly consist of carbonate platform limestones and, subordinately, dolostones pertaining to the campano-lucanian carbonate platform succession (scandone, 1972; d’argenio et al., 1973) of the upper triassic-to-senonian age. a transgressive palaeocenemiocene succession overlies in paraconformity the upper cretaceous successions. the cretaceous sediments, in particular, were deposited in shallow-water environments that show a change from restricted circulation and tidal settings during the early cretaceous to more open marine conditions in the late cretaceous (cestari, 1971). previous stratigraphic studies have been carried out by sartoni & crescenti (1963), scorziello & sgrosso (1965), sgrosso (1968) and cestari (1971). 3.2 inventory of geopalaeontological data the data were catalogued through computerized inventory tables, created on the basis of the italian geological survey indications (cf. praturlon, 1996; wimbledon et al., 1996; brancucci et al., 1999; wimbledon, 1999; d’andrea, 2000). the microsoft access 97 database was developed with several tables bearing homogeneous information (fig. 3): • geosite identification data (e.g.: country, town, province, locality, utm coordinates, height above sea level, etc.) • geosite quality (scientific importance, interest, state of preservation, etc.) • geological data (e.g.: lithology, age, age of the substratum, etc.) • palaeontological data (e.g.: biotic remains, icnite, etc.) • accessory data (degree of knowledge, presence of areal constraints, etc.) • selected references each table is related to the others through a common field (“num. progressivo”; fig. 4) which allow the unique identification of the geosite through simple queries. each table corresponds to a mask (fig. 5) created with the purpose of reducing data entry mistakes, displaying all the indications to fill in the tables, and showing indicative schemes and pictures. these tables represent a database that can be read in ms access environment and imported in a gis project. a gis prototype was created; the geopalaeontological sites are located as spots on a georeferenced topographic map (sheet 1:50.000 igm, 50/l series, 3 colors), in raster format (fig. 6). the project also contains the administrative boundaries and the limits of regional/national parks and protected areas, as indicated under law 394 of 6.12.1991 and regional law 33 of. 1.9.1993. in particular, for the proposed sites, the zones of integral reserve (zone a), general reserve (zone b) and controlled reserve (zone c) are delimited. the project was set up with geomedia pro of intergraph corporation and published on the web site of the dipartimento di scienze ambientali of the seconda università degli studi di napoli (www.sa.unina2.it). 4. description of the proposed sites as an example, one site was selected from the national park of cilento and vallo di diano and one from the regional park of matese. 4.1 regional park of matese: the serra delle macchietelle outcrop the proposed site is represented by the serra delle macchietelle hill, located at the northwestern end of the matese lake (fig. 2). serra delle macchietelle is a nw-se hill rising from the lake up to 1202 m above sea level. it is mainly made up of ne dipping limestones, well exposed along the southern flank road cut, from nw toward se (ruberti, 1991, 1992; carannante et al., inventory of the geopalaeontological ... 130 d. ruberti et al. fig. 3 – tables from the ms access 97 database concerning identification data, geological data, paleontology, geosite quality. esempi di tabelle relative al database creato in ms access 97, riferite ai dati identificativi, geologici, paleontologici e alle qualifiche del sito. 1993). early cretaceous deposits are rich in bivalves (among which requienidae and oysters), gastropods (mostly nerineids), giving rise to thick beds cyclically alternating with loferitic and stromatolitic limestones (fig. 7a, c). up in the sequence, thanatocoenosis rich in radiolitidae and caprinidae constitute small congregations (sensu gili & skelton, 2000; see also ruberti & toscano, 2002) associated with oysters and gastropods (fig. 7b). the upper cretaceous is characterized by widespread distribution of radiolitidae, locally forming well preserved assemblages supported by bioclastic sands (fig. 7d). the related lithosomes result to be delimitated and often eroded by coarse sandy deposits in which it is possible to recognize transported organisms which are often still undamaged. these lithofacies (mollusc rudstones-floatstones in a matrix of silty packstones) are generally found in more or less silt-rich lens-shaped bodies, which contain a great abundance of poorly sorted bioclastic material. the resulting rudist-rich bodies, that may be 3-10 m thick and for a few tens of meters in diameter, laterally blend into bioclastic talus in which it is common to find cross-lamination, graded beds, isorientation and imbrication of the grains. many bioclastic episodes clearly appear to have originated from storms, on the basis of associated sedimentary structures; others represent the normal breakdown of the organisms which grew developing limited positive structures, with more or less intensive reworking of the grains. deposition, therefore, took place on shelf areas on relatively shallow sea floors which might be periodically exposed, thereby undergoing dissolution phenomena. 4.2 national park of cilento and vallo di diano: the trentinara outcrop the proposed site is located in the northern margin of the cilento, nearby the village of trentinara (fig. 2). the road cut along the southern flank of mt. vesole, starting from the madonna di loreto sanctuary, shows fine outcrops characterized by subhorizontal calcareous strata in which well-preserved rudist-beds offer a bidimensional picture of cretaceous sea beds. detailed taphonomic studies (ruberti & toscano, 2002; carannante et al., 2003) have shown the species distribution in the various fossiliferous beds and the different spatial arrangement of the sedimentary bodies that range from monospecific biostromes to subtidal channelized bodies in which rudists have been found to colonize channel levees. taphonomic characterization enabled hydrodynamic control on lithosome evolution, geometry and spatial distribution to be recognized. the rudist shell beds are characterized by low species diversity, with slight differences in the abundance of a few species belonging to the durania, bournonia, sauvagesia, gorjanovicia and biradiolites genera, that usually form oligoor monospecific con131inventory of the geopalaeontological ... fig. 4 – relationships among tables in the database. esempio di relazioni tra tabelle nel database relazionale creato. 132 d. ruberti et al. fig. 5 – examples of masks supporting the tables in the database. esempio di m a s c h e r e create per l’inserimento dati nel d a t a b a s e realizzato. fig. 6 – screenshot of the gis prototipe created with geomedia 4.0 pro (intergraph) to read the database on the georeferred map. cattura a video del progetto gis realizzato con geomedia 4.0 pro (intergraph) per la visualizzazione su basi cartografiche georiferite delle banche dati relative ai geositi. gregations (fig. 8). the characteristics of the shell beds show, in the first instance, that the recognized rudist species settled and thrived in relation to the grain size and the hydrodynamics, giving rise to different lithosome composition and geometry. the taphonomic attributes of macrofossil associations were broadly categorized on the basis of carannante et al. (1998; 2000) and ruberti & toscano (2002). the internal fabric of these levels (i.e. orientation, arrangement, packing and sorting of the skeletal elements; internal microstratigraphy) allowed two broad shell bed categories to be distinguished: a) shell beds considered as “primary shell concentration” in which the shell concentration is essentially created by the behaviour of local shell producers, preserved in situ and in growth position; b) shell beds considered as “hydraulic shell concentration”, that were deposited under the influence of hydraulic processes and/or input of surrounding bioclastic sediments. all the aspects described, in terms of lithofacies associations, taphonomic aspects of the rudist congregations and their role in the depositional cycles, testify to open shelf settings periodically disturbed by higherenergy events. the latter might have resuspended finegrained sediments and caused the benthos to become unstable, though the fine fractions settled down in situ. the depositional sites were characterized by a large-scale facies polarity. under closer examination, a patchy distribution of the latter appears, often related to channelized systems or current pathways through rudist settlement areas. 5. concluding remarks knowledge and the subsequent census of the geological heritage of a region undoubtedly constitute very important elements for local administration (gisotti & massoli-novelli, 1997; zarlenga, 1996; d’andrea & di leginio, 2002), even if the motivation behind them may be simply knowledge-oriented. the value of such heritage can be enhanced by creating itineraries that highlight the geological history and dynamics of the region. indeed all regional protected areas have a large potential for tourism which has to be organised intelligently. the key to such tourist development is diversification which allows, amongst other things, a broader yearround distribution of tourist flows. hence the importance of targeting school tourism and cultural tourism in general, which is particularly busy in autumn and spring, creating a network of footpaths that allows direct observation of the area’s geological and palaeon133inventory of the geopalaeontological ... fig. 7 – serra delle macchietelle outcrop. a) close-up of a nerineid specimen. b) thicket formed by caprotinidae, closely-spaces in an upright growth position. c) floatstone rich in chondrodonta sp. and gastropods (among with acteonids and nerineids). d) radiolitid limestones. affioramento di serra delle macchietelle. a) dettaglio di un esemplare di nerineide. b) thicket formato da caprotinidi, addensate e in posizione di crescita. c) floatstone ricco in chondrodonta sp. e gasteropodi (tra cui acteonidi e nerineidi). d) calcari a radiolitidi. tological heritage is effective way to conserve and protect its cultural and natural assets. acknowledgements we thank l. simone and g. carannante (university of naples) for helpfull discussion. this contribution present results from research projects supported by italian research ministery (prin 2000 and 2002; responsible d. ruberti) and second university of naples (ex 60% founds to d. ruberti) and has been based on unpublished data of g. sirna. d. ruberti took care with sedimentological and taphonomic aspect; m. vigliotti took care of the gis project and the database organization; m. muselli realized and implemented the computerized database. the authors acknowledge a. russo and an anonymous reviewer for their thoughtful suggestions and comments. references accordi g. & carbone f. (1988) sequenze carbonatiche meso-cenozoiche. c.n.r. quaderni della ric. scientifica, vol. 114, n. 5, pp. 11-92. accordi g., carbone f. & sirna g. (1982) relationships among tectonic setting, substratum and benthonic communities in the upper cretaceous of northeastern matese geologica rom., 21, pp. 755-793. accordi g., carbone f. & sirna g. (1990) rudist communities and substratum in the matese mounts, molise, italy 2nd int. conf. on rudists. rome-bari, oct. 1990, field trip. bosellini a. (1991) introduzione allo studio delle rocce carbonatiche. italo bovolenta editore, ferrara, 317 pp. brancucci g., garton m. & pavia g. (1999) scheda inventario geositi. geoitalia, n, 4 (novembre 1999), pp. 43-49. carannante g., cherchi a. & simone l. (1995) chlorozoan versus foramol lithofacies in late cretaceous rudist limestones: in: j. philip & p.w. skelton (eds.), palaeoenvironmental models for the benthic associations of tethyan cretaceous carbonate platforms, special issue of palaeogeography, palaeoclimatology, palaeoecology, 119, pp. 137-154. carannante g., d'argenio b., ferreri v., ruberti d. & simone l. (1991) lacune stratigrafiche e bauxiti nell'appennino campano-molisano. relazione tra eustatismo e tettonica nel cretacico medio e superiore dell'italia meridionale workshop c.r.o.p. 11 roma, 28-29/11/91, pp. 20-21. carannante g., d'argenio b., mindszenty a., ruberti d. 134 d. ruberti et al. fig. 8 – trentinara outcrop. rudist rich limestones. note the close-spacing of the individuals in the monospecific congregations in a), b) and d). more complex, with moderately higher diversity, rudist beds are represented in c). affioramento di trentinara. calcari ricchi in rudiste. si noti l’addensamento dei gusci nelle associazioni monospecifiche (a, b, d). in c) è rappresentato un livello a rudiste caratterizzato da una moderatamente più elevata diversità specifica e da un organizzazione spaziale degli individui più articolata. & simone l. (1994) cretaceous-miocene shallow water carbonate sequences. regional unconformities and facies patterns ias 15th regional meeting, ischia, april 1994, pre-meeting field trip guide, pp. 25-60. carannante g., graziano r., laviano a., ruberti d., simone l., sirna g., sirna m. & tropeano m. (2001) low energy vs. high energy depositional settings and related sedimentary bodies in early senonian rudist bearing carbonate shelves (centralsouthern italy) in: proceedings of the int. meeting “anatomy of carbonate bodies” international meeting, marseille, 9-12 mai 2001, france. géologie méditerranéenne (annales de l’universite de provence), xxviii, 1-2, pp. 37-40. carannante g., graziano r., pappone g., ruberti d. & simone l. (1999) depositional system and response to ea level oscillation of the senonian foramol-shelves. examples from central mediterranean areas facies 40, pp. 1-24. carannante g., graziano r., ruberti d. & simone l. (1997) upper cretaceous temperate-type open shelves from northern (sardinia) and southern (apennines-apulia) mesozoic tethyan margins in: n.p. james and j.a.d. clarke (eds.), “coolwater carbonates”. sepm spec. publ., 56, pp. 309-325. carannante g., ruberti d. & simone l. (1993) rudists and related sediments in late cretaceous open shelf settings. a case history from matese area (central apennines, italy) giornale di geologia, bologna, v. 55/1, pp. 21-36. carannante g., ruberti d. & sirna g. (1998) senonian rudist limestones in the sorrento peninsula sequences (southern italy) gebios, m. s. 22, pp. 47-68. carannante g., ruberti d. & sirna m. (2000) upper cretacoeous l imestones from the sorrento peninsula (southern appenines, italy): microand macrofossil associations and their significance in the depositional sequences sedimentary geology, 132, pp. 89-123. carannante g., ruberti d., simone l. (2003) sedimentological and taphonomic characterization of low energy rudist-dominated senonian carbonate shelves (southern apennines, italy): a north africa perspective in: e. gili, m.h. negra & p.w. skelton (eds.), north african cretaceous rudist and coral formations and their contributions to carbonate platform development, nato asi series, kluwer, 14 pp. cestari g. (1971) note i l lustrative della carta geologica d’italia. foglio 198 (eboli) servizio geologico d’italia. cestari r. & sartorio d. (1995) rudists and facies of the periadriatic domain agip; 207 pp channel j.e.t., d'argenio b. & horvath f. (1979) adria, the african promontory, in mesozoic mediterranean paleogeography earth science reviews, vol. 15, pp. 213-292. cocco e. & d’argenio b. (1988) l’appennino campano lucano nel quadro geologico dell’italia meridionale. guida alla escursione. 74° congr. soc. geol. it., sorrento 13-17 settembre. d’andrea m. (2000) servizio geologico nazionale: progetto “conservazione del patrimonio geologico italiano”. nota informativa giornale di geologia, ser. 3a, vol. 62, suppl., pp. 121-124. d’andrea m. & di leginio m. (2002) progetto sgn: “conservazione del patrimonio geologico italiano”. i censimenti sui siti di interesse geologico in italia geologia dell’ambiente, anno x, n.2/2002, pp. 9-14. d’argenio b. (1974) le piattaforme carbonatiche periadriatiche. una rassegna di problemi nel quadro geodinamico mesozoico dell’area mediterranea mem. soc. geol. it., v.13, 2 (1974), pp. 28. d’argenio b., horvath f. & channel j.e.t. (1980) paleotectonic evolution of adria, the african promontory xxvi int. geol. congr. mem., b.r.g.m., 115, pp. 331-351. d’argenio b., pescatore t. s. & scandone p. (1973) schema geologico dell’appennino meridionale (campania e lucania atti del convegno “moderne vedute sulla geologia dell’appennino”, acc. naz. lincei, quad. 183, pp. 49-72. d'argenio b. & mindszenty a. (1992) tectonic and climatic control on paleokarst and bauxites giornale di geologia, bologna, se. 3°, 54/1, pp. 207-218. fraissinet m. & la valva v. (2001) i parchi e le riserve naturali terrestri in campania regione campania ass. alle politiche territoriali e ambiente, parchi, risorse naturali, tutela beni paesisticoambientali, ciclo integrato delle acque, difese suolo settore ecologia imago media editrice. gili e. & skelton p. w. (2000) factors regulating the development of elevator rudist congregations in: e. isalaco , p.w. skelton and t.j. palmer (eds.), carbonate platfor system: components and interactions, geological society, london, special publication, 178, pp. 109-116. gisotti g. & massoli novelli r. (1997) i geotopi nella pianificazione territoriale atti ix congr. ord. naz. geol., roma, aprile 1997, pp. 307-311. ietto a. (1970) assetto strutturale e ricostruzione paleogeografica del matese occidentale (appennino meridionale) mem. soc. nat. napoli, suppl. boll., 78, pp. 441-471. igmi (1993) carta topografica d’italia scala 1:50000 foglio 405 campobasso igm firenze, edizione 1. igmi (1993) carta topografica d’italia scala 1:50000 foglio 487 roccadaspide igm firenze, edizione 1. igmi (1993) carta topografica d’italia scala 1:50000 foglio 503 vallo della lucania igm firenze, edizione 1. masse j-p, philip j. & skelton p.w. (eds.) (1995) palaeoenvironmental models for the benthic associations of cretaceous carbonate platforms in the tethyan realm palaeogeography, palaeoclimatology, palaeoecology, 119: 1-2, special issue, 199 pp. pescatore t. (1964) rapporti tra depressione molisano-sannitica e appennino calcareo boll. soc. nat. napoli, 72, pp. 213-227. pescatore t. (1965) ricerche geologiche sulla depressione molisano-sannitica atti acc. sc. fis. mat., s.3,5(4), pp. 101-14. 135inventory of the geopalaeontological ... pons j.m. & sirna g. (1992) upper cretaceous rudist distribution in the mediterranean tethys: comparison between platforms from spain and south-central italy geologica romana, 28, pp. 341-349. praturlon a. (1996) problems of conservation of geotopes in italy in proceedings of the second international symposium on the conservation of the geological heritage, roma, june 1996: mem. descr. della carta geol. d’ital ia, servizio geologico d’italia (2000) vol liv, pp. 23-28. proceedings of the 2nd (rome, 1990), 3rd (mexico d.f., 1993), 4th (marseille, 1996), 5th (erlangen, 1999) and 6th (rovjno, 2002) international conference on rudists. radoicic r. (1987) bauxites of the internal dinarides: stratigraphy and facies of bed rock and cover (bosnia-metonja sector) rend. soc. geol. it., v.9, 2, pp. 277-280. ruberti d. (1991) il cretacico in facies di piattaforma carbonatica del matese: studi stratigrafici e sedimentologici tesi di dottorato inedita; dip. scienze della terra, università "la sapienza" di roma. ruberti d. (1992) le lacune stratigrafiche nel cretacico del matese centro-settentrionale boll. soc. geol. it., 111, pp. 283-289. ruberti d. (1997) facies analysis of a upper cretaceous high-energy rudist-dominated carbonate ramp (matese mts., central-southern apennines, italy): subtidal and peritidal cycles sedim. geol., 103, pp. 81-110. ruberti d. & toscano f. (2002) microstratigraphy and taphonomy of rudist shell concentrations in upper cretaceous limestones, cilento area (southern italy) proceedings of the “international conference on paleobiogeography & paleoecology”. piacenza & castell’arquato, may 31june2, 2001; geobios, mem. spec. n.24, elsevier, pp. 228-240. sartoni s. & crescenti v. (1962) ricerche biostratigrafiche sul mesozoico dell'appennino meridionale giorn. geologia, v.29, pp.161-388. scandone p. (1967) studi di geologia lucana, la serie calcareo-silico-marnosa ed i suoi rapporti con l’appennino calcareo boll. soc. nat. in napoli, 76, 175 pp. scandone p. (1972) studi di geologia lucana: carta dei terreni della serie calcareo-silico-marnosa e note illustrative boll. soc. nat. in napoli, 81, pp. 225300. scorziello r. & sgrosso i. (1965) segnalazione di crostacei decapodi nel paleocene di m. vesole (salerno) boll. soc. nat. in napoli, 74. selli r. (1958) sulla trasgressione del miocene in italia meridionale giorn. geologia, s. 2, 24, pp. 1-54. sgrosso i. (1968) note biostratigrafiche sul m. vesole (cilento) boll. soc. nat. in napoli, 77, pp. 159180. simo j.a.t., scott r.w. & masse j-p (eds.) (1993) cretaceous carbonate platforms aapg mem. 56, 479 pp. simone l., carannante g., ruberti d., sirna m., sirna g., laviano a., & tropeano m. (2003) rudist-rich bodies development and growth in centralsouthern italy early senonian carbonate shelves: high-energy vs low-energy settings palaeogeography, palaeoclimatology, palaeoecology, 200, pp. 5-29. sirna g. & laviano a. (1989) le rudiste. seminario su: "le comunità a grandi bivalvi del mesozoico e gli eventi geodinamici del mediterraneo",cerro veronese, 1-5/10/1989; università di roma e ferrara. unpublished. sirna g. & paris a. (1999) le rudiste del museo di paleontologia del dipartimento di scienze della terra dell’università “la sapienza” di roma geologica romana, 35, pp. 45-87. viescas j.l. (2000) microsoft access '97 per windows. mondadori informatica wimbledon w.a.p. (1999) geosites. an iugs initiative: science supported by conservation geoitalia, n.4, nov.1999, cleup, padova, pp. 40-43. wimbledon w.a.p., andersen s., clean c.j., cowie j.w., erikstad l., gongrijp g.p., johansson c.e., karis l.o. & suomnen v. (1996) geological world heritage: geosites a global comparative site inventory to enable prioritisation for conservation in proceedings of the second international symposium on the conservation of the geological heritage, roma, june 1996: mem. descr. della carta geol. d’ital ia, servizio geologico d’italia (2000) vol liv, pp. 45-60. zarlenga f. (1996) i geotopi, dalla ricerca scientifica alla pianificazione, controllo e gestione geologia dell’ambiente, vol. 4/2, pp. 3-6. 136 d. ruberti et al. amq32(1) 15-30 regattieri et al.pub middle holocene climate variability from a stalagmite from alilica cave (southern balkans)  eleonora regattieri 1,2, ilaria isola 3, giovanni zanchetta 1,3, andrea tognarelli 1, john c. hellstrom 4, russell n. drysdale 5,6, chiara boschi 2, ivica milevski 7, marjan temovski 8 1dipartimento di scienze della terra, university of pisa, pisa, italy. 2istituto di geoscienze e georisorse igg-cnr, pisa, italy. 3istituto nazionale di geofisica e vulcanologia ingv, pisa, italy. 4school of earth sciences, university of melbourne, victoria, australia. 5school of geography, university of melbourne, victoria, australia. 6edytem, umr cnrs 5204, université de savoie-mont blanc, le bourget du lac cedex, france. 7istitute of geography, university of skopje, skopje, republic of macedonia. 8icer, institute for nuclear research, hungarian academy of sciences, debrecen, hungary.   corresponding author: e. regattieri <eleonora.regattieri@unipi.it> abstract: we present a stable isotope (δ13c and δ18o) and growth rate record from a southern balkans stalagmite, lid1, deposited between ca. 8.4 and 4.1 ka. both stable isotope time series show significant changes at the centennial-millennial time scale, which are broadly consistent with variations in growth rate. the δ13c signal and the growth rate appear related to soilvegetation development over the cave catchment, influenced by regional temperature and hydrological variations. also for the δ18o record, a hydrological significance is proposed and particularly a dependence from the amount of precipitation at the cave site appears likely. comparison of the multiproxy record from lid with regional hydroclimatic and temperature records shows both similarities and differences. similarities appear related to the influences of large-scale atmospheric patterns such as the strength of the siberian high and of the north atlantic oscillation, both exerting effects on local climate parameters like temperature, precipitation amount and seasonality. differences arises from the complex interplay of different climatic regimes and of local conditions. frequency analyses of the stable isotope time series shows periodicities similar to those related to solar activity, suggesting a solar modulation for the observed variability. overall, the presented lid1 record adds a piece in the puzzle of the regional paleoclimatic framework for the middle holocene in the mediterranean region. keywords: speleothem, holocene, stable isotope, balkans.  available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 32 (1), 2019, 15 30 1. introduction the climate of the present interglacial, the holocene (11.6 ka to the present, walker et al., 2012), has been characterised by relatively stable conditions compared to the previous glacial period, but also by millennialto centennial-scale fluctuations that affected the high and low latitudes of both hemispheres (e.g. bond et al., 1997; mayewski et al., 2004). a plethora of studies, including several compilations of holocene paleoclimatic records, have aimed to reconstruct the spatial and temporal patterns of this short-term variability (e.g. mayewski et al., 2004; wanner et al., 2008, 2011). from this research, it is apparent that the variability in holocene climate is expressed in a particularly complex regional pattern. many studies particularly focus on the mediterranean region and its surroundings (e.g. roberts et al., 2008; fletcher et al., 2013). in the mediterranean, regional and global climatic change is commonly associated with variations in the amount and seasonality of precipitation (e.g. giorgi & lionello, 2008). these hydrological changes influence water availability, likely a crucial issue for the ancient civilizations that developed in the region. indeed, the assessment of interactions between holocene climate and humans is a classical issue of circum-mediterranean paleoclimatic-archaeological investigations (e.g. cremaschi et al., 2016; magny et al., 2002; bar-matthew & ayalon, 2011). in the mediterranean, lake-levels, lake-isotopes, speleothem and deep-sea sedimentary records (e.g. magny et al., 2002; roberts et al., 2008; piva et al., 2008) suggest a distinction between an early holocene characterized by conditions wetter than present and a later period with a drier climate (e.g. jalut et al., 2009; sadori et al., 2011, giraudi et al., 2011). the transition between these two states seems to be characterized by sharp and short-amplitude climate changes with regards to both temperature and precipitation (e.g. bar-matthews & ayalon, 2011; giraudi et al., 2011). it occurred in a time span, the middle holocene (ca. 8.2 ka to 4.2 ka, following walker et al., 2012), corresponding to continuing high summer insolation in the northern hemisphere, and with the boreal ice sheets no longer large enough to influence climate at hemispheric scale (wanner et al., 2008). comparison of paleoclimate records with climateforcing time series suggests that changes in insolation related both to earth’s orbital variations and to solar variability likely played a role (e.g. mayewski et al., https://doi.org/10.26382/amq.2019.02 16 regattieri e. et al. 2004, debret et al., 2009, wanner et al., 2011). further, changes in north atlantic ocean circulation and variations in strength and direction of northern westerlies, with patterns similar to the atmospheric modes of the modern day north atlantic oscillation (nao), have been proposed as drivers of holocene variability in the mediterranean (e.g. perşoiu et al., 2017; fletcher et al., 2013 domínguez-villar et al., 2008, smith et al., 2016). an influence of low-latitude climate pattern has also been detected (zanchetta et al., 2007). in this work we present a stable isotope (δ13c and δ18o) and growth rate record from a southern balkans stalagmite, lid1, deposited between ca. 8.4 and 4.1 ka. both stable isotope time series show significant changes at the centennial time scale, which are broadly consistent with variations in growth rate. we investigate the climatic and environmental meaning of the proxies, the timing and periodicity of the variability and, through comparison with other records, its regional or local significance. the aim is to reconstruct the climate of the area during the mid-holocene and the potential links with regional and global climatic patterns. 2. study site 2.1. cave setting alilica cave is located on the north side of the tresonechka river valley, in the bistra mountain range, within the mavrovo national park, in the former yugoslavian republic of macedonia (f.y.r.o.m., macedonia hereinafter, fig. 1). the cave is developed in mesozoic limestone of the western macedonian geotectonic unit fig. 1 geographic and geological setting of alilica cave: a location of alilica cave and of other sites mentioned in the text (lid= alilica cave, this study; asi = asiul cave, smith et al., 2016; sor = soreq cave, bar-matthews et al., 2011; scar = scariscoara cave, perşoiu et al., 2017); b geological setting of alilica cave (adapted from petkovski & ivanovski, 1980); c map of alilica cave (adapted from andonovski, 1980) and location of the sampling site. 17 a mid-holocene speleothem record from southern balkans (petkovski & ivanovski, 1980; karamata, 2006). it is 590 m long, with a maximum elevation range of 130 m (andonovski, 1980). the cave is interested by significant speleothem deposition and comprises two different levels (lower and upper alilica), connected by vertical passages ca. 90 m deep. the lower alilica opens at river level, at 1450 m a.s.l. the entrance is characterised by the accumulation of fluvial sand and gravel, which after periods of intense flooding block the entrance to the cave. the catchment of alilica cave is not well defined. however, it is likely that the cave drains the southwestern slope of the bistra mountain, which is covered by a beech (fagus sylvatica) forest up to 1600 m a.s.l. above 1600 m a.s.l, there is a bare karstic plateau, with sparse grassland and the presence of glacial deposits (petkovski & ivanovski, 1980; andonovski et al., 1998). all plants belong to the c3-type vegetation category. stalagmite lid1 (fig. 2) was collected already broken in the lower part of alilica cave. the cave showed active dripping at time of collection and active speleothem growth was apparent. 2.2. local climate the climate in the area is sub-mediterranean (panagiotopoulos et al. 2013), with the greater part of the annual precipitation falling in the colder part of the year (autumn and winter). in the 1300-1650 m a.s.l. altitudinal range, where alilica cave and its catchment are located, the mean precipitation amount is ca. 1050 mm/yr. this altitude belt is the wettest climatic zone in macedonia. the mean annual precipitation in the mavrovo national park is ca. 1250 mm (information from mavrovo park web-site; www. http:// npmavrovo.org.mk). moisture availability is linked mostly to cyclogenesis within the mediterranean, especially occurring in the gulf of genoa. cyclones originating there move southward following the mediterranean storm trajectories (reale & lionello, 2013; dünkeloh & jacobeit, 2003; ulbrich et al., 2012). as winter cyclogenesis in the gulf of genoa is associated with north-westerly storm tracks, an influence of north atlantic atmospheric patterns is observed in the southern balkan region, and there is a well-known negative correlation between the north atlantic oscillation (nao) strength and winter precipitation (ulbrich et al., 2012; lópez-moreno et al, 2011). other large-scale atmospheric patterns also have an influence on mediterranean cyclogenesis. for example, positive anomalies of the siberian high (a semi-permanent and quasi-stationary anticyclonic centre located in northern eurasia, dominant in the boreal winter season) have a relationship with enhanced cyclogenesis and precipitation in the mediterranean. conversely, precipitation has been found to be inversely related to the strength of the siberian high over almost all of eastern europe during the boreal winter, as well as over a large part of continental asia (rogers, 1997; panagiotopoulus et al., 2005). the activity of the siberian high is also positively related to an increase of the snow cover over all of eurasia, especially in the early winter season (cohen & entekhabi, 1999). in spring and summer, the influence of large-scale climatic patterns is low and cyclogenesis over land, where local thermal trough systems play a major role, becomes more frequent and it is related to the local topography (trigo et al., 2002). summer dry conditions are related to the expansion of the azores high, which in turn is influenced by the strength of the boreal monsoon system (xoplaki et al., 2003). the annual cycle of temperature regime shows two distinct separate seasons: warm and dry summer and relatively cold winter connected with transitional spring and autumn. mean summer temperature is of ~25°c. mean winter temperature varies around ~3°c. the mean annual temperature is ca. 16°c. the winter temperature is not significantly correlated with nao index (ulbrich et al., 2012). cold outbursts of north easterly sourced air masses can occur during the winter season and are linked to advection of polar air stimulated by the strengthening of the siberia high (panagiotopolus et al., 2005). 3. material and methods 3.1. sample description and petrography stalagmite lid1 is ca. 28 cm long and 11 cm wide (fig. 2). it is candle-shaped and made up of white to translucent calcite, with no evidence of growth interruptions. it presents continuous, flat laminations, particularly apparent in the growth axis portion of the sample (fig. 2). analyses of thin sections show that the dominant fig. 2 stalagmite lid1 with reported the subsampling for stable isotope analyses and for ages determination. on the right a microphotograph of thin section (2.5x, crossed nicols) is reported. fabric of lid1 is compact columnar calcite, with no evidence of annual lamination (fig. 2). crystals are large (up to 1 mm in length), have a regular shape, flat edges, elongated terminations and few crystal defects (fig. 2). 3.2. subsampling and stable isotope analyses the stalagmite was cut longitudinally and one of the halves was hand-polished and subsampled along the growth axis for stable isotope (δ13c and δ18o) analyses. in some portions, the drilling line was shifted laterally by a few mm, to avoid cracks and holes present on the surface. subsampling was performed at 1-mm increments using a milling machine with a 1 mm-diameter drilling bit at the ingv (insitute of geophysics and volcanology, pisa, italy) laboratory, producing 285 subsamples. for u/th dating, 15 solid prisms of ca. 150 mg (ca. 2 mm wide along the lamina and 1 mm thick on growth axis) were taken with a hand dental drill. stable isotope analyses were made with a gas bench ii (thermo scientific) coupled to a delta xp continuousflow isotope-ratio mass spectrometer at the institute of geosciences and earth resources of the italian national research council (igg-cnr, pisa). samples were digested for one hour in 105% phosphoric acid at 70 °c. measurements were made on the evolved co2 gas. results were normalized to the vienna pee dee belemnite scale using a set of internal working standards, calibrated among different laboratories and against the international standards nbs18 and nbs19. mean analytical precision is 0.15‰ and 0.10‰ (2σ) for δ18o and δ13c, respectively. 3.3. u/th dating and age modelling the u/th dating was performed at the school of earth sciences at the university of melbourne, australia, following the method of hellstrom (2003). briefly, samples were dissolved and a mixed 236u-233u-229th spike was added prior to removal of the carbonate matrix with ion-exchange resin. the purified u and th fraction diluted in nitric acid was introduced to a multicollector inductively coupled plasma mass spectrometer (mc-icpms, nu-instruments plasma). the 230th/238u and 234u/238u activity ratios were calculated from the measured atomic ratios using an internally standardized parallel ion-counter procedure and calibrated against the hu-1 secular equilibrium standard. correction for detrital th content was applied following the method described by hellstrom, 2006. this method stratigraphically constrains the 230th/232th activity ratio (230th/232th)i at the time of sample deposition, i.e. a sequence of true ages down the growth axis of a stalagmite or flowstone must become progressively older regardless of their relative degree of detrital contamination. a default initial activity ratios of detrital thorium (230th/232th)i of 1.5 ±1.5. has been employed here. the median value of 1.5, with a log-normal distribution corresponding to a 95% confidence interval of plus or minus a factor of 10, appears indeed to adequately cover the distribution of all speleothem (230th/232th)i in the compilation of 50 speleothem records presented by hellstrom (2006). all the speleothem ages are expressed as ‘before the year 2000 ce’. an age-depth model was constructed with a bayesian statistical procedure using the software stal-age (scholz & hoffmann, 2011). 3.4. cwt analyses the continuous wavelet transform (cwt, daubechies, 1990) is a multi-resolution method used for time-series analyses. in general, the cwt analysis can be applied to all time or spatial series representing a non -stationary process, with the aim to investigate changes in their periodic components. particularly, studies using wt analysis have indicated its suitability to investigate periodic components of the climatic system and their changes along the time (e.g. debret et al., 2009). cwt was performed on δ18o and δ13c data series for the whole period of lid1 growth, employing a selfimplemented matlab code described in tognarelli et al. (2018) and tognarelli (2018). no filtering was performed before the wavelet analysis in order to preserve the original frequency content of the input data. only a linear interpolation is applied to the data to produce a regular 18 tab. 1corrected (in bold) and uncorrected u/th ages for lid1 stalagmite. the activity ratios have been standardized to the hu-1 secular equilibrium standard, and ages calculated using decay constants of 9.195 ×10−6 (230th) and 2.835 × 10−6 (234u). depths are mm from top. the age* in italics was rejected as an outlier. regattieri e. et al. sampling over time and a default δt of 1 yr is used as sample rate, as this minimum value guarantees that no extraneous frequency components are introduced in the data (tognarelli et al., 2018). the morlet complex wavelet is used to compute the wavelet spectra showed in fig. 5. 4. results 4.1. chronology and growth rate the 15 u/th ages obtained for lid1 stalagmite range from 8.70 ±0.73 ka to 4.42 ±0.78 ka. all the samples display a low u content (average 10 ppb; table 1) and a significant detrital th contamination (average 230th/232th =10.9, table 1). this leads to the rather high temporal uncer 19 fig. 3 age-depth model. the pink shading indicates the 95% confidence interval, dft means distance from top. fig. 4 stable isotope and growth rate results for stalagmite lid1. grey bars indicate coherent intervals of increased isotope composition for both the δ13c and the δ18o record. in the older portion of the record, individual values are reported as lighter line, whereas the thick line is a 3pt moving average. note that y axes for δ18o and δ13c are reversed. a mid-holocene speleothem record from southern balkans tainty associated with the age determinations (table 1). in lid1, ages were almost in stratigraphical order within the associated uncertainties, except for one age which was rejected as an outlier (table 1). according to the age model (fig. 3), the stalagmite grew between 8.36 ±1.18 ka and 4.15 ±0.56 ka. the average temporal resolution of the stable isotope record is ~15 yr, changing from a mean value of ~10 yr before ca. 6.6 ka to ~20 yr afterwards. the growth rate (fig. 4) shows a major change around ca. 6.5 ±0.54 ka. prior to this, it shows an average value of ~100 μm/yr, with a small decrease to ~60 μm/yr between ca. 8.2 ±0.85 ka and 8.0 ±0.9 ka and a spike toward increased growth rate at 6.6 ±0.6 ka. after 6.5 ±0.6 ka, the growth rate is lower, averaging ~35 μm/yr, with an interval of further reduction (~18 μm/ yr) between ca. 5.7 ±1.3 ka and 5.3 ±1.3 ka. after ca. 4.5 ±0.63 ka growth rate slightly increases again, to reach values of ~70 μm/yr toward the end of the record (fig. 4). 4.2. stable isotopes stable isotope time series are shown in fig. 4. the δ18o ranges from -7.61 to -9.16 ‰ whereas δ13c ranges between -6.50 and -9.56 ‰. both stable isotope time series show significant variability at multi-decadal-tocentennial time scales. on the centennial time scale, a certain degree of similarity is apparent between the two isotope series, except for the beginning of the record, where the δ13c shows a trend of decreasing values, which is not present in the oxygen record (fig. 4). the δ13c values decrease from the onset of deposition until ca. 7.6 ±0.7 ka, then values become more stable but with a slight trend toward more positive δ13c. between 6.7 ±0.6 ka and 6.4 ±0.5 ka there is an interval of significantly increased values. afterwards, the δ13c series became again more stable but with significant and abrupt periods of more positive values between 6.0 ±0.9 ka and 5.7 ±1.2 ka, between 5.6 ±1.3 ka and 5.2 ±1.3 ka and between 4.8 ±1.0 ka and 4.6 ±0.7 ka (fig. 4). the δ18o series shows a stronger variability. values greatly oscillate between 8.4 ± 1.2 ka and 6.6 ± 0.5 ka, with significant centennial intervals of more positive values apparent at 7.6 ±0.7 ka, 7.2 ±0.6 ka and 6.9 ±0.5 ka. at ca. 6.6 ±0.6 ka δ18o values abruptly increase to their most positive, then steeply decrease again until ca. 6.2 ±0.7 ka (fig. 4). this interval of enriched δ18o composition corresponds to a similar increase in the δ13c record and to the strongest decrease in the growth rate (fig. 4). since ca. 6.7 ka, the variability of the δ18o record appears more consistent with that of the carbon record, though oxygen values oscillate to a greater extent (fig. 4). 4.3. frequency analyses the real wavelet spectra for the δ18o and δ13c series is shown in figure 5. the black line indicates the 20 fig. 5 interpolated oxygen (a-top panel) and carbon (b-bottom panel) time series of lid1 and respective real wavelet spectra. letters indicate the main trends (see section 5.4 for details) regattieri e. et al. negative carbon isotope values are related to an increase in soil development and productivity and to enhanced recharge, occurring under warmer and wetter conditions. unpredictable fractionation of carbon isotopes can arise also from kinetic effects, when calcite precipitates out of isotopic equilibrium (mickler et al., 2006). however, this is unlikely for lid1, which does not show petrographic features indicating major changes in the condition of precipitation (e.g. frisia et al., 2000). figure 6 shows the comparison between lid1 δ13c and the δ18o record of ice preserved within the scărișoara cave (scar hereinafter), in nw romania (perşoiu et al., 2017). the scar ice provides a welldated and high-resolution winter temperature record for eastern central europe, because the δ18o of cave ice reflects changes in air temperature during ice formation (september through december). noteworthy, there is a general similarity with the lid-1 δ13c record, particularly for the initial trend and for colder intervals centred at ca. 7.1 ka, 6.5 ka, 5.8 ka, 5.4 ka and 4.5 ka which correspond to a trend toward more negative δ13c and to more positive δ13c spikes, respectively (fig. 6). cold conditions in eastern and south europe results from the interplay of northward intrusion of moisture carried by mediterranean cyclones (perşoiu et al., 2017) and by increased frequency of outbreaks of cold air from the northeast over the aegean sea, coincident with strengthening of the siberian high (rohling et al., 2002). strengthening of the siberian high is also related to winter drier conditions and early winter increased snow cover in central and eastern europe (panagiotopolus et al., 2005; cohen & entekhabi, 1999). the k content from a greenland ice core is considered to be positively correlated with pressure anomalies over siberia (meeker & mayewski, 2002). thus, periods with enhanced advection of polar air (i.e. stronger siberian high) and increased southward penetration of north-easterly cold air masses should be marked by increased k concentration (e.g. rohling et al., 2002). comparison of the lid1 δ13c records with potassium content from greenland ice (core gisp2, mayewski et al., 1997, fig. 6) shows interesting similarities, both for the general trend and for some spikes in k content, which appear coincident, within combined uncertainty to cold/dry periods expressed by the lid1 carbon record and to colder intervals in the scar record (fig. 6). this similarity is more remarkable during the second part of the record (after ca. 6.6 ka, e.g. at 5.8 ka and 4.5 ka). overall, the observed similarities suggest that the δ13c signal of lid1 stalagmite is mostly related to soil-vegetation development over the cave catchment, and that the latter is strongly influenced by regional temperature and hydrological variations. this variability is potentially driven by high-latitude atmospheric circulation patterns and particularly by the strength of the siberian high. an increase in its strength indeed can causes colder and potentially drier conditions at the alilica site. accordingly, also increased snow cover during early winter would have shortened the season of plant growth, depressing the soil biological activity and influencing the δ13c record. cone of influence (coi). it delimits the spectrum in two regions: the portion below the black line can be affected by edge effects and may show frequencies that are not significant due to the total length of the record (tognarelli et al., 2018). in our case, periodicities longer than ~1000 yr are not significant (fig. 5). due to the rather large temporal uncertainty associated to the stable isotope record, periodicities shorter that 200 yr also should be considered with caution. from the wavelet spectrum, three main trends can be easily recognized in the analyses of the oxygen time series (fig. 5a). a pervasive and rather constant periodicity centred on approximately 1000 yr is apparent throughout the record (trend a in fig. 5a). it appears stable and intense especially before ca. 5-6 ka, then shifted slowly to longer periodicities of ~1200-1500 yr, though this periodicity is not fully significant as it falls below the coi (fig. 5a). at higher frequencies, a significant periodicity of ~200 yr is apparent (trend b in fig. 5a). this periodicity is stronger for the two extremities of the record, then decreases in the middle portion (i.e. between ca. 7.2 ka and 6 ka), where a lower frequency (~400 yr) is apparent. a third trend (c in fig. 5a), less stable and intense, is centred between frequencies of ~75 100 yr. also this trend shows a shift in the middle portion of the record, where it becomes weaker and slightly shifts to shorter periodicity (fig. 5a). the real wavelet power spectrum for the carbon record shows less defined trends (fig. 5b). similar to the oxygen record, a periodicity of around 1000 yr is present from the beginning of the record to ca. 5000 ka (trend a1 in fig. 5b), though less defined and weaker especially in the middle portion of the record. at higher frequencies, a broad power band of 400-750 yr is apparent from ca. 7200 yr onward (trend d, fig. 5b). as for the oxygen, pervasive and with variable intensity periodicities of 200-250 yr and 75-120 yr can be recognized throughout the record (trends b1 and c1 in fig. 5b). 5. discussion 5.1. the δ13c record speleothem δ13c values arise from the complex interplay of changes in soil co2 production and content, closed versus open system dissolution of carbonates in the soil/bedrock system, hydrological routing of water along the pathway to the drip point and/or solution degassing (e.g. fairchild et al., 2006; bajo et al., 2017). the pollen records from lakes prespa and ohrid, both located in macedonia, show that altitudes comparable to that of alilica cave remained relatively wooded throughout the middle holocene (panagiotopoulus et al., 2013; sadori et al., 2016), thus likely also the lower part of the alilica catchment was characterized by a well-developed forest soil during the whole growth period of stalagmite lid1. in temperate settings with well-developed soil, increasing speleothem δ13c values are often related to a decrease in co2 supply from soil biological activity, due to a reduction in rainfall and/or cooler climate (e.g. genty et al., 2001a; regattieri et al., 2014). reduction in water recharge can also produce degassing along the karst network, resulting in higher δ13c of drip water and speleothem (fairchild et al., 2006). conversely, more 21 a mid-holocene speleothem record from southern balkans 22 regattieri e. et al. 5.2. the growth rate three main factors combine to determine speleothem growth rates: the calcium ion concentration, the temperature of the dripwater, and the water supply rate (e.g. genty et al., 2001b). for time periods of constant vegetation, as assumed for the alilica catchment during the considered time span, growth-rate variations likely depend on soil co2 production, which in turn has the potential to correlate with surface temperature (genty et al., 2001b) and water availability (regattieri et al., 2016a). in lid1 the general pattern of the growth rate broadly resembles that of the δ13c (fig. 4), confirming that they are governed, to some extent, by similar processes, i.e. mostly to the degree of soil development in the catchment. the major growth rate decrease at ca. 6.6 ka also resembles an inflection point in both scar and gisp2 curves (fig. 6), indicating colder temperature/drier conditions. however, both the latter curves as well as the lid1 δ13c record recover afterwards, whereas growth rate remains consistently lower in the second part of the record (fig. 4). interestingly, this major change in accumulation rate is almost coincident with the end of the wettest period identified in speleothem record from the western (corchia cave, zanchetta et al., 2007; renella cave, zhornyak et al., 2011) and the eastern mediterranean (soreq cave, bar-matthews et al., 2000; bar-matthews & ayalon, 2011), partly overlapping with the deposition of sapropel s1 in the eastern mediterranean. this suggests that lid1 growth rate responded sensitively to regional hydrological variations, as well as, potentially, to changes in local temperature. 5.3 the δ18o record the oxygen isotope composition of calcite is by far the most widely used proxy in speleothem studies (e.g. lachniet, 2009). assuming a deposition close to the isotopic equilibrium, as suggested by the compact columnar fabric of lid1 (frisia et al., 2000), and the absence of diagenetic processes, the speleothem δ18o depends on the δ18o composition of the drip water and on the temperature at which the speleothem precipitated. a well-defined coefficient of -0.177‰ °c−1 was empirically derived for speleothem calcite (tremaine et al., 2011) and appears only slightly lower with respect that of -0.206 ‰ °c−1 derived from laboratory experiment by kim & o’neil (1997). the δ18o of the drip water, in relatively deep caves from temperate to arid settings, appears to mostly represent the weighted mean annual δ18o value of precipitation, δ18op, (e.g. mattey et al., 2008; baneschi et al., 2011). in the absence of cave monitoring data, and notwithstanding the limitation of this assumption, we can assume that the same holds for alilica cave. factors driving the δ18op, and thus that of the speleothem calcite (δ18o) are multiple and vary on a spatial and temporal basis (e.g. dansgaard, 1964; lachniet, 2009; drăguşin et al., 2014; perşoiu et al., 2017). in most of the mediterranean region, lower δ18o values during wetter periods are commonly reported from speleothems and also from lacustrine carbonates (e.g. barmatthews et al., 2000; columbu et al., 2017; drysdale et al., 2005, 2006, 2007; finné et al., 2014; regattieri et al., 2015; 2016b, 2017; roberts et al., 2008, zanchetta et al., 2012). this is due to the so-called amount effect, an empirical inverse relationship observed between the amount of precipitation and their δ18op (ca. −2.0‰ per 100 mm/month, bard et al., 2002), and to the negligible effects of temperature during precipitation condensation (which has a gradient of +0.3‰*1°c-1), i.e. similar but opposite to the temperature effect during carbonate deposition (bard et al., 2002). conversely, δ18op in central and northern europe is strongly correlated to temperature (+0.58‰/°c, rozanski et al., 1993), and this leads to a positive relationship between temperature and speleothem δ18o (boch et al., 2011; koltai et al., 2017; constantin et al., 2007; spötl et al. 2006). thus, the two main drivers of speleothem δ18o can be hydrology or temperature, depending mostly on the cave location. however, other effects may influence the final δ18o values. for example, changes in the seasonal distribution of the precipitation may lead to a bias toward more positive (if summer precipitation dominates) or more negative (if most of the recharge occurs during winter) mean annual value of cave water δ18o and thus of the forming calcite. also, changes in the location and/or in the isotopic composition of the source of precipitation may strongly impact the final δ18o values (bar-matthews et al., 2000). the influences of these effects are often difficult to disentangle and may be contrasting or may change during time. this, in some cases, makes it impossible to correctly identify a main driver for the observed δ18o variability and thus to assign a proper paleoclimatic interpretation to speleothem oxygen records (e.g. drăguşin et al., 2014). in the case of lid1 δ18o, the broad similarity observed with the carbon record and the occurrence of the most positive values during the major growth rate reduction (fig. 4), together with the absence of correlation with the general pattern of the scar temperature record (fig. 6) suggest that a dominant influence of temperature variations is unlikely. this is also supported by other speleothem oxygen records from southern balkans (e.g. finné et al., 2014; psomiadis et al., 2018) and specifically from macedonia (regattieri et al., 2018), all showing a negligible influence of temperature and a general dependence from hydrology. to disentangle the potential hydrological implications, it is useful to compare the lid1 δ18o record with other paleo-hydrological records for which a main driver of variability has been already proposed. fig. 6 shows 23 <<<<<< fig. 6 comparison of the lid1 δ13c record (a, this study) with δ18o record of ice from scariscoara cave (b, perşoiu et al., 2017); with k content from greenland gisp2 ice core (c, mayewski et al., 1997), sh is siberian high; with lid1 δ18o (d, this study); δ18o record from soreq cave (e, israel, bar-matthews et al., 2011); δ18o record from cueva de asiul (f, northern spain, smith et al., 2016). grey dashed lines indicate common dry/cold intervals identified among the different records. a mid-holocene speleothem record from southern balkans the comparison with the δ18o record from soreq cave (israel, bar-matthews & ayalon, 2011, fig. 1). at soreq, the amount effect is considered to control speleothem δ18o, with winter precipitation largely dominating the annual mean (bar-matthews et al., 2000; bar-matthews & ayalon, 2011). the main source of precipitation for western israel is local cyclogenesis in the aegean sea, which is linked to the same synoptic system generating cyclogenesis in the gulf of genoa, in turn related to north atlantic storm tracks (trigo et al., 2002). changes in the isotopic composition of the eastern mediterranean surface water play an important role too in the δ18o of soreq speleothem. these changes are particularly prominent during periods of sapropel deposition (barmatthews et al., 2000), as between 10 ka and 6 ka when the sapropel s1 was deposited. during these intervals, enhanced fresh-water discharge from the nile river was induced by strengthening of the african monsoon rainfall over the nile catchment. it caused 18odepleted values in the eastern mediterranean surface water, leading to 18o-depleted composition of soreq speleothem (bar-matthews et al., 2000). the comparison of lid1 and soreq records (fig. 6) shows some interesting features: for the first part of the record, when the growth rate of lid1 was higher and the sapropel s1 was deposited in the eastern mediterranean, the two records do not show any convincing covariation, likely because changes in the surface water δ18o did not affect precipitation at lid site but are prevalent in the case of soreq cave during the sapropel deposition. instead, after ca. 6.6 ka, a broad similarity appears to be present within combined uncertainties (fig. 6), particularly regarding the interval of positive values centred at ca. 6.5 ka and the general pattern of more positive δ18o composition between ca. 6 and 4.5 ka (fig. 6). this adds support to the hydrological interpretation of the lid1 oxygen record. another interesting comparison is with the δ18o record from asiul cave (northern spain, smith et al., 2016, fig. 6). at this site, the speleothem δ18o variability has been interpreted in terms of the amount of precipitation over northern iberia, in turn related to the position and strength of westerly winds bringing moisture from the mid-latitudes of the north atlantic (smith et al., 2016). stronger westerlies/higher precipitation/lower δ18op over iberia are observed when the atmospheric pressure gradients are weaker, and the zonal flow is shifted southward. this atmospheric pattern resembles conditions occurring on shorter time scale during negative nao phases, (nao-like, smith et al., 2016; sánchez-goñi et al., 2016). conversely, nao+ -like periods are characterized by lower precipitation, and thus by higher speleothem δ18o values (smith et al., 2016). the comparison between lid1 δ18o and the asiul records does not show major similarities in their general trends (fig. 6). however, two almost coeval intervals of more positive δ18o values centred at ca. 6.5 ka and 4.6 ka are apparent, within uncertainties, in both records (fig. 6). this suggests that westerly circulation and nao -like patterns of atmospheric variability and associated rainfall variations are not the main driver for δ18o variability observed at the alilica site, though an influence can be inferred during specific periods. overall the lid1 δ18o signal is likely related to hydrological variations, and potentially mostly to the amount effect. however, it is not possible to establish a straightforward link with supra-regional climate patterns, though similarities with the record of westerlies strength and position are apparent during some intervals (e.g. around 6.5 and 4.6 ka). this is due to the complexity of the climate in the balkan peninsula, which is under the influence of both mediterranean and central europe atmospheric dynamics, which may cause changes in source and seasonality of the precipitation. also, these main atmospheric patterns may have a contrasting influence and their boundaries may change over time. for example, as noted above, the strengthening of the siberian high causes dry winter conditions in the balkans, but also stimulates the mediterranean cyclogenensis which brings moisture toward this region. thus, depending on where the boundary between these two contrasting influences is located, the effect on the local hydrology can be opposite. it is also worth noting that at the alilica site (i.e. well within the land interior and located in a rainshadow area within the mountains) the influence of the local topography and the development of local thermal low-pressure centres could trigger cyclogenesis to occur locally, strongly imprinting the mean annual δ18o values of the precipitation (trigo et al., 2002). despite the fact that the interpretation of the oxygen record is complicated by these factors, the similarities observed in specific intervals with the carbon record, as well as with the records used for comparison, may deserve some more attention, and will be addressed in section 6. 5.4. frequency of variability persistent frequencies highlighted by spectral analyses may give some clues on forcing mechanisms behind climate change processes. spectral analyses of holocene records have often identified solar variability as the factor most likely responsible for decadal up to millennial periodicities observed in many records (e.g. bond et al., 2001; fletcher et al., 2013; debret et al., 2009; meeker & mayewsky, 2002). during the early holocene, a 1000-900 yr periodicity has been observed in numerous north atlantic, northern hemisphere and mediterranean palaeoclimate records, as well as in solar irradiance proxies (δ14c and 10be) (fletcher et al., 2013; debret et al., 2009; domínguez-villar et al., 2008). periodicities of ca. 400-500 yr also have been documented in residual atmospheric 14c production data (e.g. stuiver & braziunas, 1993) and were related to solar modulation. on higher frequencies, solar cycles of ~210 yr, ~88 yr, and ~11 yr appear to be strong in holocene records (steinhilber et al., 2012). regarding other potential forcing of variability and their cyclicities, a 1500-year climate cycle appears pervasive in the high latitudes of the north atlantic (bianchi & mccave, 1999; bond et al., 2001), and it is likely linked with internal oscillations of the oceanic circulation (debret et al., 2007). for lid1, the three main trends (a= ~1000 yr; b= ~200 yr, c= ~75-100) identified in the carbon and oxygen cwt spectra (fig. 5) closely approximate main 24 regattieri e. et al. periodicities addressed to solar forcing, although the shorter periodicity may not be fully significant in our record due to the large associated temporal uncertainties and to the temporal resolution of the record. to disentangle the causal relationship which relates the solar forcing to the δ18o variability can be difficult. however, the observed similarities suggest at least an indirect relationship, likely related to solar modulation of large-scale climate patterns and their effects on local climate parameters like temperature, precipitation amount and seasonality (scholz et al., 2012). for example, a highly persistent power close to ~80-110 years in the k record from greenland appears to dominate the strength of siberian high, and was related to solar variability (meeker & mayewski, 2002). interestingly, nonlinear relationships between solar intensity and the magnitude of responses of atmospheric circulation features have been proposed, with higher atmospheric responses when overall solar intensity is lowest (meeker & mayewski, 2002). this may account for changes in intensity observed in trends b and c. instead, the shift between trends a1 and a2 (i.e. from 1000 to 1200-1500 yr), resembles what was observed around 6 ka in many holocene records (fletcher et al., 2013; debret et al., 2009; domínguez-villar et al., 2008), although in the lid1 record it could not be considered fully representative due to the total length of the record and to the influence of edge effects. interestingly, the lower-frequency cyclicity after ca. 6 ka has been related in the mediterranean to shifts between a prevailing strong and weak state of the zonal flow, with impacts similar to the positive and negative modes of the present-day north atlantic oscillation (nao-like patterns, fletcher et al., 2013). 6. regional significance of the lid1 record the comparison of the lid1 record with regional and extra-regional temperature and hydrological records shows both similarities and differences (fig. 6), which can be addressed by considering the interplay of local conditions with large-scale climatic patterns. regarding the general patterns, the δ13c record shows a decreasing trend, which following our interpretation indicates warmer and wetter conditions between the beginning of the record and up to ca. 7.6 ka. this trend resembles the warming trend observed in the temperature record from scar and a decrease in the intensity of the siberian high (fig. 6). we may speculate that this trend towards an amelioration of climate conditions is related to the recovery after the so-called 8.2 event (e.g. alley et al. 1997), a widespread cold and dry interval recognized in many records from the northern hemisphere and specifically in the mediterranean (e.g. pross et al., 2009). instead, the oxygen record does not show any well-defined trend, either in the first and in the second portion of the record. for example, the widespread drying trend reported from speleothems and lakes in the mediterranean since ca. 5-6 ka (e.g. roberts et al., 2008) is not apparent in the lid1 record. up to ca. 6.6 ka the δ18o pattern appears also largely decoupled from the δ13c record, as well as from the regional hydroclimatic framework (fig. 6). this is potentially due to the overriding influence of local orographic/thermal effects and/or to changes in the season of cave recharge. however, a stronger degree of coherency with the δ13c record and with the regional situation is observed in the younger portion of the δ18o record, from ca. 6.7 ka onward, and especially for specific intervals (fig. 6). interestingly, the change in the δ18o pattern between ca. 6.5 and 6.7 ka corresponds to a dramatic and permanent decrease in the growth rate, coincident to the end of the wettest period identified in the speleothem oxygen record at corchia cave (central italy; zanchetta et al., 2007) and related to regional winter precipitation increases during the deposition of sapropel s1. at 6.5 ka all the lid1 proxies indicate a colder and drier interval. this event is also apparent in the hydrological record from soreq cave and potentially relates to an interval of persistent nao+-like conditions, as indicated by the speleothem record from cueva de asiul (northern iberia, smith et al., 2016, fig. 6). interestingly, this event is also present in the romanian temperature record (fig. 6), but it is not prominent at all in the record of siberian high strength (fig. 6), suggesting a prevailing atmospheric forcing originating in the north atlantic region which propagated southward and eastward. interestingly, the drier event at 6.5 ka in the soreq record was also related to an important cultural transition recorded from archeological records in the eastern mediterranean (i.e. from mid to late chalcolithic period, bar-matthews & ayalon, 2011), adding support to its significance in the region. it also corresponds, within combined uncertainties, to a period of rapid climate change (rcc’s), as identified by mayewski et al (2004) from a compilation of 50 globally distributed records. most of the climate change occurring during rcc’s appears characterized by polar cooling, tropical aridity, and major atmospheric circulation changes (mayewski et al., 2004), and thus generally drier conditions within the mediterranean fits well with this general background. also the compilation from wanner et al. (2011) highlights the occurrence of a cold event of global significance centered at ca. 6.3 ka. during this event a remarkable dryness existed in the asian monsoon area between about 6.9 and 6.3 ka and it was argued that east asian monsoon was extremely weak due to a cold north atlantic area and a southward shift of the itcz (wanner et al., 2011). after a brief recovery of precipitation and temperature, another event is coherently expressed by the two stable isotope series of lid1 at ca. 5.8 ka. it appears marked by strong temperature reduction in the scar record, and is associated with a strong increase in the activity of the siberian high (fig. 6), as well as by a reduction of precipitation in the soreq area (fig. 6). interestingly, it does not appear associated with changes in atmospheric conditions related to nao-like patterns (fig. 6). this may suggest a prevailing influence of eastern and high-latitudes atmospheric patterns, with the expansion of the siberian high directly influencing precipitation and temperature in the southern balkans. another interval of reduced temperature and possibly precipitation is apparent at ca. 5.4 ka. it matches, within uncertainties, the 5.6 ka dry event identified in the soreq record but also in the δ18o record from corchia cave (central italy, zanchetta et al., 25 a mid-holocene speleothem record from southern balkans 2014). this event was correlated to a coeval phase of elevated wind strength inferred from the grain-size record from the hólmsá loess profile in iceland (jackson et al. 2005), corresponding to enhanced westerly flows under persistent nao+-like condition (zanchetta et al., 2014). coherently with this interpretation, it also corresponds to a decrease in precipitation expressed by the cueva de asiul record (fig. 6, smith et al., 2016), but not to either a particular decrease in central europe temperature or to a strong increase in the activity of the siberian high (fig. 6), suggesting again a north-atlantic source of hydro-climate variability. the last event, occurring at 4.5 ka, is expressed as colder and drier in the lid1 record and it is associated with a major increase in the siberian high strength and to a strong temperature reduction in the romanian temperature record (fig. 6). it is also marked by persistent nao+-like conditions (fig. 6). this suggests that during this interval the lid site was predominantly under the influence north-atlanticmediterranean circulation, potentially indirectly influenced by the strength of the siberian high. however, it must be noted that this event is not clearly expressed by the soreq record. evidence for a cold period around 4.7 ka was proposed as well from the compilation by wanner et al. (2011). the lid1 records ends at 4.1 ka and immediately before drier and colder conditions appear clearly expressed by the two isotope series. we suggest that this latter period of climatic deterioration at the lid1 site corresponds to the widespread 4.2 event, which has been widely recognized in paleoclimatic record from the northern hemisphere (e.g. cullen et al., 2000; drysdale et al., 2006; zanchetta et al., 2016). it may also be coherent with the end of lid1 deposition, potentially due to colder/drier conditions which inhibits speleothem growth, though speleothems can cease to grow also for causes which are not climate-related (e.g. for obsolescence or closure of the drip-feeding path related to the evolution of the recharge system). 7. concluding remarks in this work we have presented a stable isotope and growth rate record from a stalagmite, lid1, which grew between 8.3 ka and 4.1 ka in the alilica cave, in the f.y.r.o.m (southern balkans). the δ13c record appears to be related to the degree of soil development in the cave catchment. the comparison with a highly resolved temperature record reconstructed from δ18o of ice from scărișoara cave, in western romania, (perşoiu et al., 2017) and with the k content of the greenland gisp ice core (mayevski et al.,1997), a proxy for the strength of the siberian high (a semi-permanent anticyclonic area which influences winter and autumn temperature in a large part of the northern hemisphere as well as precipitation in eastern and central europe, e.g. panagiotopoulos et al., 2005), suggests that the δ13c of lid1 is influenced by regional temperature and hydrological variations, especially since ca. 6.7 ka (fig. 6). intervals of increased δ13c corresponding to temperature reductions in the scărișoara record are apparent at ca. 7.1 ka, 6.5 ka, 5.8 ka, 5.4 ka and 4.5 ka (fig. 6). most of these events also correspond to intervals of increased strength of the siberian high. the proposed mechanism is that such strengthening causes an increase in the occurrence of north-easterly outbursts of cold polar air (rohling et al., 2002), exerting a downstream effect on regional winter temperature and precipitation in the balkan peninsula and depressing the soil biological activity at the lid1 site. this relationship seems to be confirmed by the growth-rate record, which shows a general pattern similar to the δ13c record, both being related to co2 supply from soil. interestingly, the long-term trend of the growth rate, which shows a major and permanent reduction at ca. 6.7 ka, appears to be strongly influenced by regional hydrology, with the major decrease corresponding to the end of the wettest period highlighted by speleothem records from western and eastern mediterranean (zanchetta et al., 2007; barmatthews et al., 2000). the δ18o record broadly resembles that of the carbon, especially for the centennial scale variability and particularly since 6.7 ka (figs. 4 and 6). this, and the absence of positive correlation with the scărișoara record, allows us to rule out a temperature dependency for the δ18o variability, which appears related to overall hydrological variations, and potentially mostly to the amount effect. however, it is not possible to establish an unequivocal link with supra-regional climate patterns, possibly due to the overriding influence of local orographic/thermal effects on the δ18o of precipitation. these effects appear to dominate especially in the first part of the record (i.e before ca. 6.7 ka), where the δ18o record appears largely decoupled from the regional conditions. in this portion it is likely that the δ18o signal is buffered by multiple and contrasting processes, which make the climatic signal difficult to disentangle. later, although a unequivocal forcing for the observed variability is still difficult to constrain, more similarities with the regional situation are observed (fig. 6), and especially more positive δ18o spikes at ca. 6.5 ka, 5.8 ka and 4.5 ka can be linked to regionally-recognized events of reduced precipitation. a combined influence of north atlantic-mediterranean atmospheric patterns versus eastern high-latitude dynamics driven by the siberian high may be suggested, and changes in the boundary between these two influences likely are responsible for the complex pattern observed. overall, the presented lid1 record adds a piece in the puzzle of the regional paleoclimatic framework for the middle holocene in the mediterranean region. finally, the occurrence of periodicities similar to those related to solar activity also suggests a solar modulation of large-scale climate patterns, exerting effects on local climate parameters like temperature, precipitation amount and seasonality. acknowledgments this paper is the result of ccalma (climate from caves and lakes in macedonia) working group, which paralleled the development of the scopsco-icdp project on lake ohrid. this work has been partly funded by the australian research council discovery project dp160102969arc. we thank the mavrovo national park and the speleological society “peoni” from skopje for the warm logistic support during field work. we also thank a. perşoiu for providing scar data. we greatly 26 regattieri e. et al. thank a.e. fallick and another anonymous reviewer for their positive comments. references alley r.b., mayewski p.a., sowers t., stuiver m., taylor k.c., clark p.u. (1997) holocene climatic instability: a prominent, widespread event 8200 yr ago. geology, 25(6), 483-486. andonovski t. (1980) cave system alilica. sedmi jugoslovenski speleološki kongres. speleološko društvo sr crne gore, 21-30 (in macedonian). andonovski t., manakovik d., stojmilov a., stojanovik m., (1998) geomorfološka karta na republika makedonija. prosvetno delo, skopje (in macedonian). bajo p., borsato a., drysdale r., hua q., frisia s., zanchetta g., woodhead j. (2017) stalagmite carbon isotopes and dead carbon proportion (dcp) in a near-closed-system situation: an interplay between sulphuric and carbonic acid dissolution. geochimica et cosmochimica acta, 210, 208227. baneschi i., piccini l., regattieri e., isola i., guidi m., lotti l., zanchetta g. (2011) hypogean microclimatology and hydrology of the 800-900 m asl level in the monte corchia cave (tuscany, italy): preliminary considerations and implications for paleoclimatological studies. acta carsologica, 40(1), 175187. bard e., delaygue g., rostek f., antonioli f., silenzi s., schrag d.p. (2002) hydrological conditions over the western mediterranean basin during the deposition of the cold sapropel 6 (ca. 175 kyr bp). earth and planetary science letters, 202(2), 481494. bar-matthews m., ayalon a., kaufman a. (2000) timing and hydrological conditions of sapropel events in the eastern mediterranean, as evident from speleothems, soreq cave, israel. chemical geology, 169(1-2), 145-156. bar-matthews m., ayalon a. (2011) mid-holocene climate variations revealed by high-resolution speleothem records from soreq cave, israel and their correlation with cultural changes. the holocene, 21(1), 163-171. bianchi g.g., mccave i.n. (1999) holocene periodicity in north atlantic climate and deep-ocean flow south of iceland. nature, 397(6719), 515. boch r., cheng h., spötl c., edwards r.l., wang x., häuselmann p. (2011) nalps: a precisely dated european climate record 120-60 ka. climate of the past, 7(4), 1247-1259. bond g., showers w., cheseby m., lotti r., almasi p., priore p., bonani g. (1997) a pervasive millennial-scale cycle in north atlantic holocene and glacial climates. science, 278(5341), 1257-1266. bond g., kromer b., beer j., muscheler r., evans m. n., showers w., bonani g. (2001) persistent solar influence on north atlantic climate during the holocene. science, 294(5549), 2130-2136. cohen j., entekhabi d. (1999) eurasian snow cover variability and northern hemisphere climate predictability. geophysical research letters, 26(3), 345-348. columbu a., drysdale r., capron e., woodhead j., de waele j., sanna l., bajo p. (2017) early last glacial intra-interstadial climate variability recorded in a sardinian speleothem. quaternary science reviews, 169, 391-397. constantin s., bojar a.v., lauritzen s.e., lundberg j. (2007) holocene and late pleistocene climate in the sub-mediterranean continental environment: a speleothem record from poleva cave (southern carpathians, romania). palaeogeography, palaeoclimatology, palaeoecology, 243(3-4), 322-338. cremaschi m., mercuri a.m., torri p., florenzano a., pizzi c., marchesini m., zerboni a. (2016) climate change versus land management in the po plain (northern italy) during the bronze age: new insights from the vp/vg sequence of the terramara santa rosa di poviglio. quaternary science reviews, 136, 153-172. cullen h.m., demenocal p.b., hemming s., hemming g., brown f.h., guilderson t., sirocko f. (2000) climate change and the collapse of the akkadian empire: evidence from the deep sea. geology, 28 (4), 379-382. dansgaard w. (1964) stable isotopes in precipitation. tellus, 16(4), 436-468. debret m., bout-roumazeilles v., grousset f., desmet m., mcmanus j.f., massei n., trentesaux a. (2007) the origin of the 1500-year climate cycles in holocene north-atlantic records. climate of the past, 3, 569-575. debret m., sebag d., crosta x., massei n., petit j.r., chapron e., bout-roumazeilles v. (2009) evidence from wavelet analysis for a mid-holocene transition in global climate forcing. quaternary science reviews, 28(25-26), 2675-2688. domínguez-villar d., wang x., cheng h., martínchivelet j., edwards r.l. (2008) α highresolution late holocene speleothem record from kaite cave, northern spain: δ18o variability and possible causes. quaternary international, 187(1), 40-51. drăguşin v., staubwasser m., hoffmann d.l., ersek v., onac b.p., vereş d. (2014) constraining holocene hydrological changes in the carpathianbalkan region using speleothem δ18o and pollenbased temperature reconstructions. climate of the past, 10, 1363. drysdale r.n., zanchetta g., hellstrom j.c., fallick a. e., zhao j.x. (2005) stalagmite evidence for the onset of the last interglacial in southern europe at 129±1 ka. geophysical research letters, 32(24). drysdale r., zanchetta g., hellstrom j., maas r., fallick a., pickett m., piccini l. (2006) late holocene drought responsible for the collapse of old-world civilizations is recorded in an italian cave flowstone. geology, 34(2), 101-104. drysdale r.n., zanchetta g., hellstrom j.c., fallick a.e., mcdonald j., cartwright i. (2007) stalagmite evidence for the precise timing of north atlan 27 a mid-holocene speleothem record from southern balkans tic cold events during the early last glacial. geology, 35(1), 77-80. dünkeloh a., jacobeit j. (2003) circulation dynamics of mediterranean precipitation variability 1948-98. international journal of climatology, 23(15), 18431866. fairchild i.j., smith c.l., baker a., fuller l., spötl c., mattey d., mcdermott f. (2006) modification and preservation of environmental signals in speleothems. earth-science reviews, 75(1-4), 105-153. finné m., bar-matthews m., holmgren k., sundqvist h.s., liakopoulos i., zhang q. (2014) speleothem evidence for late holocene climate variability and floods in southern greece. quaternary research, 81(2), 213-227. fletcher w.j., debret m., sánchez-goñi m.f. (2013) mid-holocene emergence of a low-frequency millennial oscillation in western mediterranean climate: implications for past dynamics of the north atlantic atmospheric westerlies. the holocene, 23 (2), 153-166. frisia s., borsato a., fairchild i.j., mcdermott f. (2000) calcite fabrics, growth mechanisms, and environments of formation in speleothems from the italian alps and southwestern ireland. journal of sedimentary research, 70(5), 1183-1196. genty d., baker a., massault m., proctor c., gilmour m., pons-branchu e., hamelin b. (2001a) dead carbon in stalagmites: carbonate bedrock paleodissolution vs. ageing of soil organic matter. implications for 13c variations in speleothems. geochimica et cosmochimica acta, 65(20), 34433457. genty d., baker a., vokal b. (2001b) intra-and interannual growth rate of modern stalagmites. chemical geology, 176(1-4), 191-212. giorgi f., lionello p. (2008) climate change projections for the mediterranean region. global and planetary change, 63(2-3), 90-104. giraudi c., magny m., zanchetta g., drysdale r.n. (2011) the holocene climatic evolution of mediterranean italy: a review of the continental geological data. the holocene, 21(1), 105-115. hellstrom j. (2003) rapid and accurate u/th dating using parallel ion-counting multi-collector icp-ms. journal of analytical atomic spectrometry, 18(11), 1346-1351. hellstrom j. (2006) u-th dating of speleothems with high initial 230th using stratigraphical constraint. quaternary geochronology, 1(4), 289-295. jackson m.g., oskarsson n., trønnes r.g., mcmanus j.f., oppo d.w., gro ̈nvold k., sachs j.p. (2005) holocene loess deposition in iceland: evidence for millennial-scale atmosphere-ocean coupling in the north atlantic. geology, 33(6), 509-512. jalut g., dedoubat j.j., fontugne m., otto t. (2009) holocene circum-mediterranean vegetation changes: climate forcing and human impact. quaternary international, 200(1-2), 4-18. karamata s. (2006) the geological development of the balkan peninsula related to the approach, collision and compression of gondwanan and eurasian units. geological society, london, special publications, 260(1), 155-178. kim s.t., o’neil j.r. (1997) equilibrium and nonequilibrium oxygen isotope effects in synthetic carbonates. geochimica and cosmochimica acta, 61, 3461-3475. koltai g., spötl c., shen c.c., wu c.c., rao z., palcsu l., bárány-kevei i. (2017) a penultimate glacial climate record from southern hungary. journal of quaternary science, 32(7), 946-956. lachniet m.s. (2009) climatic and environmental controls on speleothem oxygen-isotope values. quaternary science reviews, 28(5-6), 412-432. lópez-moreno j.i., vicente-serrano s.m., morán-tejeda e., lorenzo-lacruz j., kenawy a., beniston m. (2011) effects of the north atlantic oscillation (nao) on combined temperature and precipitation winter modes in the mediterranean mountains: observed relationships and projections for the 21st century. global and planetary change, 77(1-2), 62 -76. magny m., miramont c., sivan o. (2002) assessment of the impact of climate and anthropogenic factors on holocene mediterranean vegetation in europe on the basis of palaeohydrological records. palaeogeography, palaeoclimatology, palaeoecology, 186(1-2), 47-59. mattey d., lowry d., duffet j., fisher r., hodge e., frisia s. (2008) a 53 year seasonally resolved oxygen and carbon isotope record from a modern gibraltar speleothem: reconstructed drip water and relationship to local precipitation. earth and planetary science letters, 269(1-2), 80-95. mayewski p.a., meeker l.d., twickler m.s., whitlow s., yang q., lyons w. b., prentice m. (1997) major features and forcing of high-latitude northern hemisphere atmospheric circulation using a 110,000year-long glaciochemical series. journal of geophysical research: oceans, 102(c12), 2634526366. mayewski p.a., rohling e.e., stager j.c., karlén w., maasch k.a., meeker l.d., lee-thorp j. (2004) holocene climate variability. quaternary research, 62(3), 243-255. meeker l.d., mayewski p.a. (2002) a 1400-year highresolution record of atmospheric circulation over the north atlantic and asia. the holocene, 12(3), 257-266. mickler p.j., stern l.a., banner j.l. (2006) large kinetic isotope effects in modern speleothems. geological society of america bulletin, 118(1-2), 6581. panagiotopoulos f., shahgedanova m., hannachi a., stephenson d.b. (2005) observed trends and teleconnections of the siberian high: a recently declining center of action. journal of climate, 18 (9), 1411-1422. panagiotopoulos k., aufgebauer a., schäbitz f., wagner b. (2013) vegetation and climate history of the lake prespa region since the lateglacial. quaternary international, 293, 157-169. perșoiu a., onac b.p., wynn j.g., blaauw m., ionita m., 28 regattieri e. et al. hansson m. (2017) holocene winter climate variability in central and eastern europe. scientific reports, 7(1), 1196. petkovski p., ivanovski t. (1980) geological map and guide book for sheet kičevo (k 34-90), basic geological map of sfrj 1:100000. federal geological survey (in macedonian with english abstract). belgrade, pp. 69. piva a., asioli a., trincardi f., schneider r.r., vigliotti l. (2008) late-holocene climate variability in the adriatic sea (central mediterranean). the holocene, 18(1), 153-167. pross j., kotthoff u., müller u.c., peyron o., dormoy i., schmiedl g., smith a. m. (2009) massive perturbation in terrestrial ecosystems of the eastern mediterranean region associated with the 8.2 kyr bp climatic event. geology, 37(10), 887-890. psomiadis d., dotsika e., albanakis k., ghaleb b., hillaire-marcel c. (2018) speleothem record of climatic changes in the northern aegean region (greece) from the bronze age to the collapse of the roman empire. palaeogeography, palaeoclimatology, palaeoecology, 489, 272-283. reale m., lionello p. (2013) synoptic climatology of winter intense precipitation events along the mediterranean coasts. natural hazards and earth system sciences, 13(7), 1707-1722. regattieri e., zanchetta g., drysdale r.n., isola i., hellstrom j.c., roncioni a. (2014) a continuous stable isotope record from the penultimate glacial maximum to the last interglacial (159-121 ka) from tana che urla cave (apuan alps, central italy). quaternary research, 82(2), 450-461. regattieri e., giaccio b., zanchetta g., drysdale r.n., galli p., nomade s., wulf s. (2015) hydrological variability over the apennines during the early last glacial precession minimum, as revealed by a stable isotope record from sulmona basin, central italy. journal of quaternary science, 30(1), 1931. regattieri e., zanchetta g., drysdale r.n., isola i., woodhead j.d., hellstrom j.c., dotsika e. (2016a) environmental variability between the penultimate deglaciation and the mid eemian: insights from tana che urla (central italy) speleothem trace element record. quaternary science reviews, 152, 80-92. regattieri,e., giaccio,b., galli,p., nomade,s., peronace,e., messina,p., gemelli,m. (2016b) a multiproxy record of mis 11-12 deglaciation and glacial mis 12 instability from the sulmona basin (central italy). quaternary science reviews, 132, 129-145. regattieri e., giaccio b., nomade s., francke a., vogel h., drysdale r.n., boschi c. (2017) a last interglacial record of environmental changes from the sulmona basin (central italy). palaeogeography, palaeoclimatology, palaeoecology, 472, 51-66. regattieri e., zanchetta g., isola i., bajo p., perchiazzi n., drysdale r.n., wagner b. (2018) a mis 9/ mis 8 speleothem record of hydrological variability from macedonia (fyrom). global and planetary change, 162, 39-52. roberts n., jones m. d., benkaddour a., eastwood w.j., filippi m.l., frogley m.r., stevens l. (2008) stable isotope records of late quaternary climate and hydrology from mediterranean lakes: the isomed synthesis. quaternary science reviews, 27(25-26), 2426-2441. rogers j.c. (1997) north atlantic storm track variability and its association to the north atlantic oscillation and climate variability of northern europe. journal of climate, 10(7), 1635-1647. rohling e., mayewski p., abu-zied r., casford j., hayes a. (2002) holocene atmosphere-ocean interactions: records from greenland and the aegean sea. climate dynamics, 18(7), 587-593. rozanski k., araguás-araguás l., gonfiantini r. (1993) isotopic patterns in modern global precipitation. climate change in continental isotopic records, 78, 1-36. sadori l., jahns s., peyron o. (2011) mid-holocene vegetation history of the central mediterranean. the holocene, 21(1), 117-129. sadori l., koutsodendris a., masi a., bertini a., combourieu-nebout n., francke a., peyron o. (2016) pollen-based paleoenvironmental and paleoclimatic change at lake ohrid (south-eastern europe) during the past 500 ka. biogeosciences, 13, 1423-1437. sanchez-goñi m.f., rodrigues t., hodell d.a., polanco-martinez j.m., alonso-garcía m., hernández-almeida i., ferretti p. (2016) tropically-driven climate shifts in southwestern europe during mis 19, a low eccentricity interglacial. earth and planetary science letters, 448, 81-93. scholz d., hoffmann d.l. (2011) stalage-an algorithm designed for construction of speleothem age models. quaternary geochronology, 6(3-4), 369-382. scholz d., frisia s., borsato a., spötl c., fohlmeister j., mudelsee m., mangini a. (2012) holocene climate variability in north-eastern italy: potential influence of the nao and solar activity recorded by speleothem data. climate of the past, 8(4), 13671383. smith a.c., wynn p.m., barker p.a., leng m.j., noble s.r., tych w. (2016) north atlantic forcing of moisture delivery to europe throughout the holocene. scientific reports, 6, 24745. spötl c., mangini a., richards d.a. (2006) chronology and paleoenvironment of marine isotope stage 3 from two high-elevation speleothems, austrian alps. quaternary science reviews, 25(9-10), 1127 -1136. steinhilber f., abreu j. a., beer j., brunner i., christl m., fischer h., miller h. (2012) 9,400 years of cosmic radiation and solar activity from ice cores and tree rings. proceedings of the national academy of sciences, 109(16), 5967-5971. stuiver m., braziunas t.f. (1993) modeling atmospheric 14 c influences and 14 c ages of marine samples to 10,000 bc. radiocarbon, 35(1), 137189. tognarelli a., zanchetta g., regattieri e., isola i., drysdale r.n., bini m., hellstrom j.c. (2018) 29 a mid-holocene speleothem record from southern balkans wavelet analysis of δ18o and δ13c time-series from an holocene speleothem record from corchia cave (central italy): insights for the recurrence of dry-wet periods in the central mediterranean. italian journal of geosciences, 137(1), 128-137. tognarelli a. (2018) the use of continuous wavelet transform for ground-roll attenuation. 80th eage conference. doi 10.3997/2214-4609.201801417 tremaine d.m., froelich p.n., wang y. (2011) speleothem calcite farmed in situ: modern calibration of δ18o and δ13c paleoclimate proxies in a continuously-monitored natural cave system. geochimica et cosmochimica acta, 75(17), 4929-4950. trigo i.f., bigg g.r., davies t.d. (2002) climatology of cyclogenesis mechanisms in the mediterranean. monthly weather review, 130(3), 549-569. ulbrich u., lionello p., belušić d., jacobeit j., knippertz p., kuglitsch f.g., nissen k.m. (2012) climate of the mediterranean: synoptic patterns, temperature, precipitation, winds, and their extremes. in the climate of the mediterranean region (pp. 301346). eds lionello, p. elsevier insights walker m.j., berkelhammer m., björck s., cwynar l.c., fisher d.a., long a.j., weiss h. (2012) formal subdivision of the holocene series/epoch: a discussion paper by a working group of intimate (integration of ice-core, marine and terrestrial records) and the subcommission on quaternary stratigraphy (international commission on stratigraphy). journal of quaternary science, 27(7), 649659. wanner h., beer j., bütikofer j., crowley t.j., cubasch u., flückiger j., küttel m. (2008) mid-to late holocene climate change: an overview. quaternary science reviews, 27(19-20), 1791-1828. wanner h., solomina o., grosjean m., ritz s.p., jetel m. (2011) structure and origin of holocene cold events. quaternary science reviews, 30(21-22), 3109-3123. xoplaki e., gonzalez-rouco j.f., luterbacher j., wanner h. (2003) mediterranean summer air temperature variability and its connection to the large-scale atmospheric circulation and ssts. climate dynamics, 20(7-8), 723-739. zanchetta g., drysdale r.n., hellstrom j.c., fallick a.e., isola i., gagan m.k., pareschi m. t. (2007) enhanced rainfall in the western mediterranean during deposition of sapropel s1: stalagmite evidence from corchia cave (central italy). quaternary science reviews, 26(3-4), 279-286. zanchetta g., van welden a., baneschi i., drysdale r., sadori l., roberts n., sulpizio r. (2012) multiproxy record for the last 4500 years from lake shkodra (albania/montenegro). journal of quaternary science, 27(8), 780-789. zanchetta g., bar-matthews m., drysdale r.n., lionello p., ayalon a., hellstrom j.c., regattieri e. (2014) coeval dry events in the central and eastern mediterranean basin at 5.2 and 5.6 ka recorded in corchia (italy) and soreq caves (israel) speleothems. global and planetary change, 122, 130-139. zanchetta g., regattieri e., isola i., drysdale r.n., bini m., baneschi i., hellstrom j.c. (2016) the socalled “4.2 event” in the central mediterranean and its climatic teleconnections. alpine and mediterranean quaternary, 29(1), 5-17. zhornyak l.v., zanchetta g., drysdale r.n., hellstrom j.c., isola i., regattieri e., couchoud i. (2011) stratigraphic evidence for a “pluvial phase” between ca 8200-7100 ka from renella cave (central italy). quaternary science reviews, 30(3-4), 409417. 30 regattieri e. et al. ms. received: september 19, 2018 final text received: january 8, 2019 amq29(2) 4 palombo 143-168nag.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 29 (2), 2016, 143 168 large mammals faunal dynamics in southwestern europe during the late early pleistocene: implications for the biochronological assessment and correlation of mammalian faunas maria rita palombo dipartimento di scienze della terra, sapienza università di roma, rome, italy corresponding author: m.r. palombo <mariarita.palombo@uniroma1.it> abstract: this research aims to investigate the large mammal faunal dynamics in sw europe during the late early pleistocene. at that time, the climate forcing known as mid-pleistocene revolution (mpr) induced deep, more or less gradual alterations and latitudinal displacements in european terrestrial biomes and exerted great influence on dispersal and dispersion of mammalian species. large mammals did not generally move in multi-species waves of dispersal, rather each species changed its range depending on the suitability of environmental conditions in respect to its own environmental tolerances and ecological flexibility. factors driving the remodelling of the range of a taxon, and time and mode of its dispersal and diffusion into sw europe differed from species to species as from one territory to another, leading to diachronicity/asynchronicity in local first appearances/lowest local stratigraphical occurrences. as a result, correlations and biochronological assessments of local faunal assemblages may be difficult especially when firm chronological constraints are unavailable. whether the peculiar composition of the late early pleistocene fauna, characterised by the persistence of some villafranchian species and discrete new appearances of some taxa that will persiste during the middle pleistocene, may be indicative of any high rank biochronological unit is discussed. evidence from sw europe suggests that the chronological range of the so-called epivillafranchian biochronological unit (whatever its biochronological rank could be) may span from about 1.5 (i.e. lowest local stratigraphical occurrence, llso datum, of, among others, homo, xenocyon lycaonoides, canis ex gr. c. mosbachensis, megantereon whitei, advanced stenonoid horses, praemegaceros, bison) and about 0.85 ma (i.e. highest local stratigraphical occurrence, hlso datum, of x. lycaonoides, m. whitei, p. pardoides). the biochronological unit would tentatively correspond from a biostratigraphical point of view to a virtual “range-zone”, i.e. the hypothetical body of strata representing the known stratigraphical occurrence in w europe of x. lycaonoides-m. whitei. nonetheless, several factors (e.g. the confusing taxonomic treatment of some taxa, the heterogeneous consistency of the fossil record in space and time particularly as regard the number and richness of local faunal assemblages -, taphonomical biases, and the apparent dyachronicity asynchronicity of llso of some species that dispersed toward western europe during the post-olduvai early villafranchian) make it difficult any attempt to “formalise” the “epivillafranchian biochronological unit" as a european land mammal age (elma). all in all, several lines of reasoning suggest an informal use of the term epivillafranchian, pending a complete revision of the villafranchian elma, its subdivisions and of the rank that each subdivision may actually have. keywords: biochronology, bioevents, epivillafranchian, large mammals, late early pleistocene, sw europe 1. introduction disentangling issues dealing with climate changes, mammal faunal dynamics and its implications for long distant correlations in the continental realm, is a challenging task due to a number of hotly debated, unanswered questions behind them (e.g. walsh, 1998; barnoski et al., 2003; gingerich, 2003; van dam, 2003; lindsay, 2003; prothero, 2004, 2012; barnosky, 2005; barnosky & kraatz, 2007; prideaux et al 2007; lawler et al., 2009; stewart, 2009;davies et al., 2011; badgley & finarelli, 2013; blois et al., 2013; fortelius et al., 2014; fernández et al., 2015 and references in those papers). during the evolutionary history of our planet, especially during the cenozoic, climate changes were a recurring phenomenon (zachos et al., 2001) and a number of sequences of ecological and evolutionary events developed on a backdrop of climatic change, both warming and cooling phases (e.g. the oligo-miocene so-called grande coupure by stehlin, 1910), although cooling episodes generally had a major impact at the boreal middle latitudes. some organisms, however, seem to have remained “the same” over thousands to perhaps millions of years in the face of environmental perturbations, highlighting that the biotic response of individuals, species and communities to climate warming and cooling events is a highly complex phenomenon. some other organisms, especially small mammals, rapidly evolved, thus their fossil record could be an important base for the biochronological divisions and regional correlations between distant stratigraphic sequences/successions (see among others e.g. chaline, 1972, 1987; van der meulen, 1973; agustí, 1986; maul & markova, 2007; cuenca bescós et al., 2010; maul & parfitt. s. a., 2010; minwerbarakat et al., 2011; lozano-fernández et al., 2013; mayhew, 2013; palmqvist et al., 2014). the synergistic action of climate and environmental changes, biotic interactions and feedback processes undoubtedly had some effects on the physiology of organisms as well as on changes in the distribution of species and shifts of the limits of their range. during the quaternary, in keeping with the vegetational cover and latitudinal displacement of biomes, large mammals, for work presented during the aiqua scientific conferences "waiting for the nagoya inqua xix congress", held in florence, june 18 19, 2015 144 m.r. palombo instance, more frequently reacted to climate changes by varying the limits of their range than by originating new species in loco (see e.g. magri & palombo, 2013; palombo, 2015a and references therein). as a result, discrete dispersal bioevents, introducing alien species into previously existing large mammal communities, changed their structure, giving rise to new internal dynamics that led to a progressive reorganisation of mammalian faunal complexes. this is the reason why dispersal is not only one among the fundamental processes in biogeography (crucial for understanding the evolutionary dynamics of organism distribution throughout time and across space) but also a factor to carefully consider for making feasible correlations among local faunal assemblages and fossiliferous distant stratigraphic sequences/successions. reconstructing and correlating chronological sequences by means of large mammal fossil record is a problematic task because the continental sedimentary record is highly discontinuous, distribution of sites in time and space is not homogenous, rare species are sparsely represented, and ghost lineages are not so uncommon due to ecological factors and/or taphonomical and sampling biases. in addition, continuous sedimentary sequences are rare and a number of local faunal assemblages lack sound chronological constraints. as a result, the known stratigraphic lowest/ highest occurrence of a taxon within a geographical area does not necessarily reflect the timing of its actual first/last appearances in time (e.g. lindsay, 2003; palombo, 2009 and references therein) and the diachronous appearance of a taxon may not necessarily depict its actual dispersal trajectory. understanding time and mode of biological dispersals and their consequences is therefore of crucial interest for any chronological assessment of local faunal assemblages, as well as for correlations and identification/characterisation of biochronological units. this research aims to investigate whether the peculiar composition of the late early pleistocene fauna (characterised by the persistence of some villafranchian species and discrete new appearances of some taxa that will have persisted during the middle pleistocene) may be indicative or not of any high rank biochronological unit (i.e. european land mammal age, elam). 2. material and methods the database consists of taxonomically revised lists of large mammal species (with a body weight of at least 10 kg) from selected local faunal assemblages (lfas) mainly from sw europe. a few western european lfas, having a particular relevance for a better understanding of changes in the fauna structure in the post-olduvai early pleistocene, were added to the analysis. the analysed lfas range in age from about 1.6 to 0.8 ma (v5a, v5b and g1 faunal complexes in palombo, 2014). besides to lfas with a sound stratigraphic control, also isolated finds having particular taxonomical or chronological relevance were added to the analysis. the lists were compiled by revising and updating those resulting from previous studies on the pleistocene mammals from w europe (see e.g. breda et al., 2010; lister et al., 2010; kahlke et al., 2011; palombo, 2014, 2015a). lutrini were not included in the study because of the scantiness and disproportion of their fossil record in time and space across the studied region. to provide a uniform baseline for the study material, the identifications of species was based on a taxonomical uniform view even for species/specimens whose taxonomy, systematics, and identification are controversial. 3. discrete dispersal events and lowest local stratigraphical occurrences of large mammals during the post-olduvai early pleistocene in sw europe in the post-olduvai early pleistocene, in sw europe discrete bioevents led to a progressive reorganisation of mammalian faunal complexes that lasted during the beginning of the middle pleistocene. the bioevents mainly consist of dispersals of few carnivores that either disappeared by the end of the early pleistocene or were still recorded in the middle pleistocene, and of large herbivores, most of which persisted throughout the middle pleistocene. a few extinctions of some among the most specialized villafranchian species, and originations of new taxa in indigenous phyletic lineages are also recorded. changes in the suitability of environments and the extent of ecological barriers triggered by climate changes affected time and mode of organism dispersal (see e.g. colbert et al., 2012; schlosset al, 2012). during the active diffusion known as secular dispersal (which may take place so slowly that the diffusing species can undergo appreciable evolutionary change during the process), a species range can expand, contract or creep (expand in one direction while contracting in another). sometimes organisms can move across great distances and a population of the original disperser's descendants may successful establishes at the endpoint, whereas no viable populations may be present in the crossed territories. moreover, barriers can either prevent the range of some taxa to reach some regions or cause long delays in dispersal, slowing or hampering the spread of a taxon in some territories. all considered, occasional jump-dispersals, the slow, progressive shift of the range (including translation) and the filtering action of barriers synergistically acted during seculardispersal, leading to the diachronous versus asynchronous local appearances/disappearances of dispersing taxa. as a result, species-specific patterns of secular dispersal and dissimilarities in the interand intra-guild competition (sometimes leading to speciation and extinction events at a local scale) may cause taxonomical composition of faunal assemblages to differ at a local scale even within the same geographical region. in sw europe, discrete dispersal bioevents of taxa originally coming from both asia and africa led to a complex interplay among inter-sub-region dispersals and temporary shifts in the amplitude of the range of some species. the process, merging previously independent taxa in new palaeocommunities, triggered changes in the taxonomic and structural composition of mammalian 145 late early pleistocene mammalian assemblages from sw europe ............ faunal complexes. mammals having a broad niche and high ecological tolerance persisted in face of alien species invasion and environmental changes, whilst the most specialized one disappeared (palombo, 2014, 2015a, b and references therein). available data indicate that during the late early pleistocene, the local lowest stratigraphical occurrence (llso) of a number of large mammal species was asynchronous across most of europe. only a few diachronous liso permit to follow the displacement/ enlargement of the limit of the species’ range throughout time (palombo, 2015b and references therein). several factors (e.g. the different impact of global climate changes in different geographical settings, differences in species resilience and variability in competition and predation patterns within local faunal complexes, heterogeneity of the fossil record in space and time and taphonomical biases) may have caused asynchronous appearances, though their interplaying is challenging to disentangle. as a result, the correct chronological order of lfas and the correlation among fossiliferous stratigraphic sequences may be difficult to ascertain. hence, the successions of sw european fcs here proposed (fig 1) and the resulting chronological assessment of sw european lfas can be regarded as the “best-fit” allowed by available data. 3.1. major bioevents within the large carnivore guild the european carnivore guild was progressively renewed throughout the late early pleistocene, though the lowest and highest stratigraphical occurrences of some species were slightly asynchronous across the region (fig 2). the middle sized canid canis mosbachensis (whose taxonomy and phylogenetic relationships divide scholars, see e.g. thenius, 1954; kurtén, 1968; bonifay, 1971; kurtén & poulianos, 1977; pons-moyà, 1987; palmqvist et al., 1999; sotnikova, 2001; olive, 2006; brugal & boudadi-maligne, 2011), was recorded for the first time in the mediterranean region about 1.5 ma in the ‘ubeidiya lfa (jordan rift valley, israel), and may have dispersed towards sw europe roughly in the same period. the species, indeed, is recorded at about 1.5-1.4 ma (v5a fc) in the iberian (venta micena lfa) and italian (pirro nord lfa) peninsulas, together with the larger, hypercarnivous lycaon-like dog xenocyon lycaonoides, which origined by anagenetic evolution from xenocyon falconeri. in france the two canids are first reported later, shortly before (c. mosbachensis, v5b fc) and during (x. lycaonoides, g1 fg) the jaramillo palaeomagnetic event respectively (cf. martínez-navarro & rook, 2003; moullé et al., 2006; olive, 2006; brugal & boudadi-maligne, 201; palombo, 2015a for contrasting opinions). the african sabre-toothed cat megantereon whitei possibly dispersed towards europe shortly after the olduvai-matuyama paleomagnetic inversion. in spain and italy the species is recorded roughly at the same time at venta micena (spain), pirro nord and argentario promontory (italy). m. whitei is reported in greece (apollonia 1 lfa, =m. cultridens in koufos, 2014) and maybe in france (ceyssaguet “couche 2” =m. cultridens in tsoukala, 2004; argant & bonifay, 2011) for the first time shortly before the jaramillo palaemagnetic event, fig. 1 biochronological setting and chronological scheme for the post-olduvai early pleistocene mammalian record from sw europe. fig. 2 biochronological setting of selected post-olduvai early pleistocene large mammals from sw europe (spain =orange; france =green, italy =bue) the data on which this table is based were established by using first/last historical apparence (fha/lha) bioevents inferred from the lowest/highest occurrences of fossil remains in fossiliferous levels of key iberian, french and italian localities (lsdk/hsdk =lowest/ highest known stratigraphical datum). as discussed in palombo (2009), the lowest and highest stratigraphical records of a taxon, respectively correspond to the “terminus ante quem” and “terminus post quem” of the actual time of the origination and extinction biovents (fha/ lha). hence, new discoveries may substantially change the chronological range of taxa on which the scheme proposed here is based. rt =ranging-through taxa ? =doubtful presence because of uncertain taxononomical identification and/or unsure chronological setting of finding sites and at about 1.1 ma in central europe (e.g. untermassfeld, germany, =m. cultridens adroveri, hemmer, 2001). the time of dispersal of the leopard in eurasia is uncertain. the species is not reported thus far in the early pleistocene of asia, while it presence in europe has been questioned due to the arguable identification of two lower carnassial teeth from le vallonnet, tentatively identified as p. pardus (de lumley et al., 1988; moullé et al., 2005). during the early middle pleistocene p. pardus was certainly present in italy (e.g. valdemino lfa, masini & sala, 2007), while it is doubtfully reported in the iberian peninsula (panthera sp., sima de los huesos lfa, see gracía et al., 1997 for a discussion), where it was present for sure in the late middle pleistocene (cueva del congosto lfa, palombo et al., 2009). remains of cheetah-like cats identified as a. pardinensis were reported from a number of sw european late early pleistocene lfas, though they would not represent the same taxon within the a. pardinensis ‘macrospecies’. their presence may be related to a dispersal event (see hemmer et al., 2008, 2011 for a discussion). the subspecies a. pardinensis pleistocaenicus, descendant of the asian subspecies a. p. linxiaensis, dispersed towards europe during the late early pleistocene climatic worsening and aridification increasing. the llso in weurope (abotut 1.05 ma at untermassfeld, germany, and le vallonnet, france) is slightly younger than that in north china (about 1.25 ma, qiu, 2006) (hemmer, 2001; hemmer et al., 2011; kahlke, 2006; spassov, 2011). the spotted hyaena appeared in europe later, by the end of the early pleistocene. its llso is at atapuerca (trinchera de ferrocarril, northern spain) in the td4w level of gran dolina (garcía & arsuaga, 2001), dated to about 0.9 ma (berger et al., 2008). in italy, the spotted hyaena is first recorded about 0.720.68 ma bp in the ponte galeria 2 lfa (roman basin) (palombo & milli, 2011; sardella & petrucci, 2012), and a bit later in france at about 0.6-0.5 ma bp (grotte xiv, cénac-et saint-julien, langlois, 2002). some members of the large carnivore guild, first recorded in the post-olduvai early pleistocene, likely originated from lineages already present in sw europe. for instance, the hypothesis that the remains from le vallonnet (1.0 ma, france), gran dolina tdw4 (ca. 0.9 ma, northern spain) and vallparadís (cgrd5, evt10, evt7 and evt6, ca. 1.0-0.83 ma, vallés-penedés basin, spain) may belong to the cave bear lineage (ursus ex group u. deningeri) cannot be discounted (dabney et al., 2013; madurell-malapeira et al., 2014 and references therein). tempo and mode of the appearance of extant european lynxes are debated as well as the taxonomic rank of the middle pleistocene south european ones. lynx issiodorensis, a widespread species recorded in a number of early pleistocene sites, is regarded by most authors as the common ancestor of the european (lynx pardinus and asian (lynx lynx) lineages. lynx spelaeus/ lynx pardinus spelaeus (see boscaini, 2014 and references therein for a discusssion) is first recorded in italy at valdemino (? mis15, nocchi & sala, 1997; ghezzo et al., 2014) and in france at l’escale (ca. 0.6-0.5 ma; bonifay, 1971) and arago cave (ca. 0.55 ma; mis14; moigne et al., 2006). the llso of the species, however, may date back to the late early pleistocene, though the identification of the scanty remains found in the french lfas of la sartanette and le vallonnet (respectively dated to about 1.3 and 1.0 ma) is challenging. the disappearance, i.e. the highest local stratigraphical occourence (hlso), of some large villafranchian carnivores was sometimes nearly contemporaneous, sometimes slightly asynchronous across the studied region. pachycrocuta brevirostris is last recorded in spain in the evt7 layer of vallparadís section dated to about 0.86 ma (duval et al., 2015), and in italy in the slivia lfa, believed to be close in age to the early to middle pleistocene transition (palombo, 2009 and references therein). the species seems to have disappeared in france in the post-jaramillo early pleitocene, while is still recorded in central europe during the early middle pleistocene (e.g. süssenborn lfa, turner & anton, 1996). vallparadís estació (layer evt7) records the hlso of the puma-like cat p. pardoides in europe (madurell-malapeira et al., 2010b). in italy the species is last recorded in the pirro nord lfa (petrucci et al., 2013) and in france even earlier [but see hemmer (2001) as regards to the lower carnassial teeth from le vallonnet discussed above]. panthera gombaszoegensis was the villafranchian felid that lasted for the longest time in europe. its disappearance was apparently diachronous. the species is last recorded in italy at the early to middle pleistocene transition (slivia lfa), in spain in the earliest middle pleistocene (gran dolina td8a lfa, van der made, 2013), in france in the early middle pleistocene (grotte xiv lfa cénac-et-saint-julien, ?mis 15, mis 13) (see langlois, 2002), and finally in southern poland in the late middle pleistocene (biśnik cave, mis 9 or mis 10) (marciszak, 2014). the species was also recorded at atapuerca in the sima de los huesos lfa (minimum age 427±12 ka, arnold et al., 2014) by morales et al. (1987), but the poor diagnostic morphology of some metatarsals, intermediate in dimension between the jaguar like cat and the leopard, prevents any firm specific identification (gracía et al., 1997). 3.2. major bioevents within the primary consumer and omnivore guilds changes in the guild of primary consumers recorded in the post-olduvai early pleistocene consist of: i) discrete appearances of herbivores mainly dispersing into sw europe from asia via east europe and africa, ii) some originations of new species within phyletic lineages already present in sw europe, and iii) discrete disappearances of the less ecologically flexible taxa in the face of alien species invasion and the climate instability, forerunner of the mid-pleistocene revolution/ transition (mpr/t) (in its broadest definition between 1.2 and 0.5 ma, head & gibbard, 2005; mcclymont et al., 2013) (fig 2). among biovents believed to be related to the climate worsening and increasing in aridity, the replacement of leptobos representatives (e.g. leptobos (smertiobos) etruscus) by bison species, more gregarious, and adapted to open, somehow arid environment, is regarded as an important event, reflecting the climatic 148 m.r. palombo and environmental change. the llsos of primitive, small bison in sw europe are traced between 1.6-1.2 ma. in spain (venta micena, fuente nueva-3, barranco león-5 and atapuerca sima del elefante te9), and in italy (pirro nord) (martinez navarro et al., 2011; van der made, 2013; masini et al., 2013; palombo, 2015b). in france a more advanced species, bison schoetensacki, is present at the time of jaramillo subchron (le vallonnet) (moullé et al., 2006 and references therein). in the same period a primitive species, bison menneri, with quite long, slender metapodials is recorded in central europe at untermassfeld (germany) (sher, 1997), together with a long-legged large deer eucladoceros giulii. the latter has been regarded as the final, large stage of the eucladoceros lineage in w europe, and one among the epitomes of the “epivillafranchian” biochronological unit (see inter alios kahlke h-d., 1997, 2001; croitor & kostopoulos, 2004; kahlke r-d., 2009). the replacement of eucladoceros representatives by giant deer belonging to the asian tribe megacerini has been regarded as an important component of the the post-olduvai early pleistocene faunal turnover. eucladoceros and large deer belonging to praemegaceros and megaloceros groups (or even avernoceros as claimed by some authors), however, seem to have coexisted in europe during the post-olduvai early pleistocene (see inter alios kahlke h-d., 1997, 2001; croitor & kostopoulos, 2004; croitor, 2009; van der made & dimitrijević, 2015 and references in those papers). authors, for instance, are divided as the identification of the giant deer recorded at about 1.5 ma in the venta micena lfa (v5a fc) [praemegaceros solilhacus in menéndez (1987) and vislobokova, (2013); eucladoceros giulii in van der made (1999); praemegaceros verticornis in espigares (2010)], though the hypothesis that the giant deer from venta micena may belong to the genus praemegaceros seems to be the most parsimonious. at about that time, praemegaceros obscurus is recorded in italy in lfas dating from about 1.5 to 1.3 ma (e.g. val di chiana, selvella, pietrafitta, and pirro nord lfas of v5a fc) (napoleone et al., 2003; abbazzi, 2004; croitor, 2006; petronio & marcolini, 2013 and references therein). in france the llso of p. obscurus is slightly younger (about 1.2 ma, ceyssaguet lfa) (croitor & bonifay, 2001 and reference therein), while the presence of the species in spain is questionable. a part for the disputed presence at venta micena (see above), the appearance of p. verticornis, generally considered as more advanced than p. obscurus, was slightly asynchronous across the studied region. the species is reported shortly before the jaramillo palaeomagnetic event (about 1.4-1.3 ma bp) in spain (barranco léon 5 and fuente nueva 3, v5b fc) (abbazzi, 2010), and during the jaramillo submagnetochron in italy (colle curti, coltorti et al., 1998) and possibly in france (saint prest, guérin et al., 2003; vislobokova, 2013, but see bonifay, 1981; geraads, 1990; lister, 1993 for contrasting opinions). giant deer of the megaloceros lineage appeared shortly after the praemegaceros ones. a giant deer showing some similarities with megaloceros savini may be present about 1.2 ma in greece (libakos lfa) and in northern spain (sima del elefante lfa, atapuerca) (cf. van der made & tong, 2008). the species is identified roughly at the same time at (cal guardiola layer cgrd2(terrassa, catalonia) (madurell-malapeira et al., 2015). specimens identifiable as or closely relate to m. savini (i.e. in spain megaloceros novocarthaginiensis from cueva victoria, van der made, 2015) were present from the jaramillo time to the transition to the middle pleistocene in spain, france and italy, while the species became more common during the early middle pleistocene (see e.g. vislobokova 2011, 2013 and references therein). a further evidence of the progressive, environmental related modifications of the first consumer guild across sw europe is given by the roughly synchronous appearance of the slender, middle-sized equus altidens (whatever related to in loco origination or a dispersal from asia, see alberdi and palombo, 2013 and van del made, 2013 for a discussion), and the slightly asynchronous llso of the larger equus suessenbornensis. e. altidens is recorded, for instance, at about 1.5-1.4 ma in spain (venta micena lfa) and italy (selvella and pirro nord lfas). the species was possibly present in france (lézignan-le-cèbe lfa) slightly later, between 1.3 and 1.1 ma (lézignan-le-cèbe lfa) (bourguignon et al., 2014, 2015). e. suessenbornensis is recorded firstly in italy (selvella and pirro nord), then in spain (barranco león 5 and fuente nueva 3) and maybe even later in france (lézignan-le-cèbe and possibly le vallonnet) (alberdi, 2010; alberdi and palombo, 2013; bourguignon et al., 2015). during the jaramillo submagnetochron, a horse, equus wuesti, slender but quite larger than e. altidens, is recorded in germany in the untermassfeld lfa (musil, 2001). a horse, similar in size to e. altidens, but more robust, with wider distal articular surface and stronger keels (equus apolloninsis) was present roughly at the same time in greece at apollonia (1.2 to 0.9 ma) (koufos et al., 1997; spassov, 2003), and possibly in the slightly older site of tsiotra vryssi (konidaris et al., 2015). the exact taxonomical position of e. wuesti and e. apolloniensis, the later believed to show some ass characters (eisenmann & kuznetsova, 2004), is controversial, although the hypothesis that they represent different local ecomorphotypes (maybe species?) of the same lineage seems quite reasonable. during the mpr, and consistently with the spread of open environments in sw europe, a number of caprini representatives (subtribe caprina and ovibovina sensu ropiquet & hassanin, 2005; hassanin, & ropiquet, 2009) were recorded, whatever their appearance was related to an intraregional dispersal or they came from eastern europe. among others, praeovibos, already reported at the latest gelasian-early calabrian transition from the fonelas lfa (guadixbaza basin, spain) (arribas et al., 2009) and in the caucasus at dmanisi (crégut-bonnoure, 2007) (=ovibovini indet. in buksianidze, 2005), is recorded shortly after the olduvai/matuyama palaeomagnetic inversion first in italy (casa frata lfa, v4 fc) (masini el al., 2013) and then in spain (venta micena and barranco de los conejos, v5a fc) (crégut-bonnoure, 2007). p. mediterraneus is reported around the time of jaramillo palaeomagnetic event also in france (e.g. le vallonnet) and greece (apollonia 1) (crégut-bonnoure, 2002, 2007). 149 late early pleistocene mammalian assemblages from sw europe ............ the “steppe goat” soergelia minor is recorded for the first time in spain (venta micena) and italy (monte argentario) (martinez navarro et al., 2012). whether the geographical distribution range of the more advanced species soergelia brigittae included or not the most of the mediterranean region (at least from france to greece, where the species is recorded in the apollonia 1 lfa, kostopoulos, 1997) is a matter of debate, due to the contrasting identification of the caprini remains found at le vallonnet and tour de grimaldi (see crégutbonnoure 2005; 2007; crégut-bonnoure & dimitrijevic, 2006; van der made, 2013 for a discussion). the remains were ascribed by moullé et al. (2004) to a new species, ammotragus europeus, which was also identified in spain, at fuente nueva 3 (guadiz-baza basin). the presence in spain in the pre-jaramillo early pleistocene of a bovid closely related to the extant barbary sheep ammotragus levia poses a question about the alleged dispersal from africa to europe of the barbary sheep as well as the origin of the extant species, seen as endemic of africa (cf. geraads, 2010). authors also disagree on the identification of ovibovina remains from pirro nord, identified as “ovibovini” indet. by de giuli et al. (1987) and as megalovis cf. m. balcanicus by crégut-bonnoure & dimitrijevic (2006). although some affinities with megalovis cannot be discarded, the orientation of horn cores of an unpublished, badly preserved skull and the rather low hypsodonty index of molars make problematic any firm identification of the ovibovina remains from pirro nord (cf. masini et al., 2013 for a discussion). there are also some divergences about the identification of a number of european early pleistocene caprina remains. in particular scholars disagree about the taxonomy and systematic of thar/goat remains found in the post-olduvai lfas from sw european. a primitive capra, may be descending from capra dalii recorded at dmanisi (caucasus) (bukhsianidze & vekua, 2006), is recorded in the late gelasian fauna of fonelas 1 (spain) (=capra betica n. sp., arribas and garrido, 2008b). during the post-olduvai early pleistocene, primitive caprina remains are reported in a number of spanish lfas, ranging in age from about 1.5 to 0.9 ma (v5a to g1 fc) (venta micena, barranco léon, fuente nueva, quibas, huéscar 1), but their systematic, taxonomy and phylogeny are controversial. some authors consider them as belonging to a goat-like taxon “capra alba”, may be descending from the fonelas 1 goat, for others spanish remains would belong to the genus hemitragus (h. albus), or eventually they might belong to a clade related to pseudovis or ammotragus (cf. crégut-bonnoure, 2007 and van der made et al., 2008 for a discussion). these uncertainties make it difficult to ascertain whether the appearance of capra? alba/hemitragus albus related to anagenetic evolution within an endemic lineage or to any dispersal event. during the post-olduvai early pleistocene hemitragus is confidently recorded at le vallonnet (=hemitragus bonali in moullé et al., 2006; =h. cf. h. orientalis in crégut-bonnoure, 2007). among taxa believed to inhabit open environments, theropithecus, a herbivore primate assumed to inhabit rocky environments as its extant relative t. gelada, is sparsely reported from few eurasian sites. the african baboon appeared in asia (t. oswaldi delsoni) at about 1 ma bp (lower boulder conglomerate, mirzapur, punjab, india) (delson 1993 and references therein), and roughly at the same time in sw europe, where it is only recorded in the cueva victoria lfa (murgia, spain) (gibert et al., 1995), a site dated to about 0.85 ma (from 0.98 to 0.78 ma) (gibert et al., 2015). theropithecus sp. has claimed to be present at ‘ubeidiya (israel) about 1.5 ma (belmaker, 2002). assuming the identification of remains from ‘ubeidiya as correct, it seems rational to suppose that the african pleistocene baboon reached sw asia about 1.5 ma bp, and then the dispersal of small populations (maybe across poorly suitable territories) enlarged the species range towards eurasia. tempo and mode of such a dispersal are, however, difficult to ascertain (cf. hughes et al., 2008). on the one hand, the alleged dispersal towards europe by crossing the strait of gibraltar (cf. ferràndez-cañadell et al., 2014) is hardly probable if not impossible (see o’regan, 2008 for a discussion). on the other, the hypothesis that the species followed a levantine dispersal route and would be unknown in the european intermediate areas because sub-optimal climatic and environmental conditions caused low population densities and a concomitantly extremely sparse fossil record, needs to be fully substantiated. it is worth noting, however, that some other species are recorded in one or just a couple of sw european sites [i.e. among others, the small sized buffalo from venta micena (spain), which shows some similarities with the chinese species hemibos gracilis, (martinez-navarro et al., 2012), and the problematic remains of “ammotragus/soergelia” mentioned above]. therefore, it is conceivable that the scattered distribution of some species depends on taphonomic factors and on the disparity of the fossil record during time and across space in the studied region. the long-term cooling trend and the environmental instability that intensified from about 1.2 ma possibly facilitated the expansion towards sw europe of the limits of the range of some generalist, ecologically flexible species. among others, suids belonging to the so-called “scrofic group” dispersed towards w europe shortly before the jaramillo subchron. suids likely different from the villafranchian sus strozzi [a species reported for the last time at about 1.5 ma in val di chiana (italy) (palombo et al. 2003; napoleone et al., 2003)], is recorded at about 1.2 ma in the layer te9 of sima del elefante (atapuerca, northern spain) (=sus sp. in carbonell et al., 2008; sus gr. scrofa in martinez-navarro et al., 2015). primitive, large wild boars were present shortly later (1.1 to 1.0 ma) in germany (untermassfeld) (sus scrofa priscus, guerin & faure, 1997), in france (le vallonnet) (sus sp. in moullé et al., 2006) and spain (vallparadís estació layer evt12 =sus scrofa priscus, madurell-malapeira et al., 2010; gran dolina td6b =sus scrofa, van der made, 1998) (cf. palombo, 2015a and references therein). elaphine cervids were likely present around the jaramillo submagnetochron in france at saint prest (grossouvre et stehlin, 1912; guérin et al., 2003) (=cervus elaphus acoronatus in di stefano & petronio, 150 m.r. palombo 1992), and in spain at barranc de la boella (about 1.0 ma) (mosquera et al., 2015). red deer lacking at the top of the antler even in adult individuals a multi-pointed “crown”, cervus elaphus acoronatus, appeared by the end of the early pleistocene in spain (atapuerca, gran dolina td6 and tdw4) (van der made, 1999) and italy (slivia) (a lfa estimated to be older than the matuyama -brunhes boundary (bon et al., 1992; gliozzi et al., 1997; palombo et al., 2003; sala & masini, 2007). reddeer representatives are also recorded in germany (dorn-du ̈rkheim) (franzen et al., 2000) and in the levantine corridor (cervus cf. c. elaphus, gesher benot ya’akov) (hooijer, 1959). the achievement of a so large geographical range confirms the ecological flexibility of this “generalist” species, a mixed-feeders, inhabiting a variety of environments, even though red deer prefer open woodlands. the major bioevent in the primary consumer guild recorded at the transition from the early to middle pleistocene is the arrival in sw europe of two elephantini (palaeoloxodon antiquus and mammuthus trogontherii). an isolated but well-preserved molar found at slivia (istria, ne italy) may document the first appearance of straight-tusked elephants in sw europe (palombo, 1995; palombo & ferretti, 2005). palaeoloxodon likely reached europe from africa during the latest early pleistocene, following a dispersal route along the levantine corridor and maybe the balkanic coasts (see palombo 2015a for a discussion). timing and mode of the replacement of m. meridionalis by m. trogontherii in europe during the early to middle pleistocene transition actually depict a complex scenario susceptible to be differently interpreted (e.g. cladogenic evolution, hybridization) (see lister et al., 2005 for a discussion). although a few species mostly inhabiting forest also appeared in the late early pleistocene [e.g. capreolus representatives recorded in germany (untermassfeld) (kahlke, 1997), italy (castagnone), (siori and sala, 2007), and spain (villaluenga del rosarioel chaparral) (pacheco et al., 2011)], the progressive taxonomical and functional change of the herbivore/omnivore guild during the post-olduvai early pleistocene was mainly related to the spread of open landscapes. the synergistic action of cooling, decrease in humidity, the combined effects of forest reduction and grassland extent allowed some large mammals (commonly inhabiting grassland/savannah-like or even mountain environments), to enlarge the limits of their range into the sw european region, though at difference pace and time. 4. the biochronological significance of the progressive modification of the mammalian fauna at the late early to early middle pleistocene transition in sw europe the discrete, sometimes diachronous/ asynchronous appearance of a number of large mammals recorded in sw europe during the post-olduvai early pleistocene resultes from the complex interplay among a few anagenetic evolutionary processes within indigenous phyletic lineages, discrete dispersal bioevents of taxa originally coming from asia and africa, and shifts in the amplitude of the range of some sw european species that triggered intra-regional dispersals (palombo, 2015a). the filtering effects of ecological and physical barriers, the structure of palaeocommunities, and the resilience of resident mammals may have played a critical role in regulating the pace of the appearances of each taxon in each area. the resident most flexible taxa persisted in face of alien species invasion and environmental changes, while the most specialized disappeared, some others were apparently present either in only one locality or within a small geographical area. as a result, the competition/coevolution dynamics and the taxonomical and structural composition of mammalian palaeocommunities changed at a different pace across the studied region. the difference in time and entity of dispersal events and related phenomena (upset of palaeocommunity internal equilibrium, keystone species extirpation, new inter-guild and intra-guild dynamics) at a local scale became more and more evident across the sw european region at the beginning and during the mpr. it is well known that the transition from the early to middle pleistocene marks a fundamental change in the earth’s climate system (maslin & ridgwell, 2005). from about 1.2 to 0.8 ma, fluctuations in δ18o values significantly increased (lisiecki & raymo, 2005) and orbital obliquity at 41-ka cycles was superseded progressively by a rhythm of about 100 ka (berger & jansen, 1994). the amplitude of climatic oscillations significantly increased. glacial-interglacial cycles acquired a more and more marked asymmetric structure (slow ice build-up, fast melting) thought to be associated 151 late early pleistocene mammalian assemblages from sw europe ............ _______________________________________________ >>>>>> fig. 3 chronological assessment and faunal list of selected local faunal assemblages (lfas) ranging in age from about 1.5 to 0.7 ma. ? = doubtful presence; (?) = highly questionable identification; x? = doubtful identification; x(?) = identification possibly correct, although based on weak morphological/biometrical characters; x^ = ew bones identified as hemitragus by van der made (2013), whereas according to crégut-bonnoure (2007) they belong partim to hemitragus, partim to soergelia genus; (?*) and (x?*) =large deer identified as p. verticornis and e. giulii by guérin et al. (2003) and lister (fide breda & marchetti, 2005) respectively. locality, colour of the name: orange = spain, green = france, blue = italy; black = west europe. green square = lowest local stratigrafical occurrence; gray square = lowest/highest local stratigrafical occurrence. (1) the group includes ursus dolinensis, ursus rodei and other specimens possibly belonging to ursus deningeri-ursus spelaeus lineage (see madurell-malapeira et al, 2014); (2) the group includes specimens identified as lynx pardinus spelaeus and lynx spelaeus; (3) including specimens identified as m. cultridens adroveri (hemmer, 2001) and megantereon “advanced form” (sardella, 1998); (4) the identification of specimens from pirro nord, already identified as “ovibovini indet.” (de giuli et al., 1987) has been questioned by masini et al. (2013). with fourth or fifth processional cycles, which have an important control on seasonality. in the course of the mpr, the response of biota was regionally different and vegetation and mammalian taxa varied with different regional timings and modes. as reported by magri & palombo (2013) as regard to sw europe, from about 1.5 ma there was a general change of both forest composition and mammalian community structure: a substantially similar vegetation dynamics were found across the studied region, (e.g. suc and popescu, 2005; tzedakis et al., 2006; leroy et al., 2011; sadori et al., 2013; combourieu-nebout, et al., 2015), while the change in faunal composition and structure show significantly different trends at a local scale (palombo 2014, 2015a, b). the llso/hlso of a number of taxa in selected key early and early middle pleistocene european sites (fig. 3) on the one hand confirms the diachronicity/ asynchronicity of some local appearance/disappearance biovents, on the other puts out that some taxa were present either in only one locality or in a restricted territory. the discrete appearances of species belonging to different taxonomical groups discounts any “migratory wave” model as causal factor for the faunal reorganisation at the time of the mpr, while the scattered record of some species, especially the rare ones, suggests a possible influence of the heterogeneous consistency of the fossil record and taphonomical factors in altering the original composition of each lfa, as well as the actual chronological order of the first/last local appearances. 4.1 the matter of the question available evidence indicates that the faunal transition from the villafranchian to the galerian european elmas (tentatively regarded here as encompassing the time slice from about 1.5 to 0.8 ma during which v5a,b and g1 fcs are recorded in sw europe, see palombo, 2014) was not an “abrupt” phenomenon, but a quite long, progressive transformation phase, which sometimes developed in a diachronous way across the european region. a common trait of many sw european late early pleistocene lfas (v5a,b and g1 fc) is their peculiar taxonomical composition, which includes both long-lasting villafranchian taxa at their latest evolutionary stage and primitive representatives of some lineages, which will characterise the so-called typical galerian fauna (early middle pleistocene, g2 fc in palombo, 2014). the resulting large mammal faunal complex was regarded by some scholars either as formed by a mix of villafranchian and galerian taxa, or the manifestation of a quite short (bonifay, 1978; azzaroli, 1983), thought composite ‘transitional phase’ [e.g. azzaroli et al. (1988) stated that the “end-villafranchian dispersal event”, chronologically close to jaramillo, from 1.0 to 0.9 ma, “did not take place at once”], or a much longer period of a progressive fauna modification, lasting about 0.6 ma (roebroeks & kolfschoten, 1995), or even more. agusti & moyà-solà (1998), for instance, discarded the concept of an “end-villafranchian dispersal event” because in their view the dispersal phase had already started during the olduvai submagnetochron with the arrival in europe of asian small and large mammals, such as m. (allophaiomys) pliocaenicus, lemmus, and “ovibovini”. the agusti & moyà-solà’s “phase” in it original meaning, however, refers to the “modernisation” shown by the classic late villafranchian fauna (as epitomized by the olivola+tasso italian faunal units, sensu gliozzi et al., 1997), ranging in age from about 1.9-2.0 to 1.7-1.6 ma. the faunal transition from the villafranchian to the galerian elmas was seen by other researchers as a “bioevent” (or a sum of bioevents) marking the end of the villafranchian elma (=end-villafranchian event, azzaroli et al., 1988; azzaroli, 1995; latest villafranchian, koufos, 2001; final villafranchian, spassov 2003), or the beginning of the galerian elma (gliozzi, 1997), or also an individual high rank biochronological unit (e.g. protogalerian, caloi and palombo, 1995; epivillafranchian sensu kahlke, 2000, 2007, 2009; epivillafranchian sensu bellucci et al., 2015). the proposed “event/faunal complex/biochron” as defined by scientists differ, however, each other in fauna composition and structure, chronostratigraphical meaning and temporal extent. the “latest villafranchian”, for instance, would correspond to about the whole calabrian stage (from ~1.8 to ~0, 78 ma), the “final villafranchian” would extend from about 1.6 to 1.1 ma (farneta and pirro fu, sensu gliozzi et al., 1997) (spassov, 2003), while caloi & palombo (1995) introduced the term protogalerian as a potential biochronological unit, in the context of a discussion for a reasonable biochronological arrangement for the transition from the villafranchian to galerian elma. the italian authors discussed three hypotheses mainly based on the ltalian mammal fauna: a) the beginning of the galerian corresponds to the climate worsening of mis 22/24, b) the transition from the villafranchian to galerian fauna roughly developed at the time of matuyama-jaramillo inversion, c) the so-called “transitional fauna” represents an individual biochronological unit, i.e. the protogalerian, characterised by the “appearance of the "galerian forms", persisting into the early middle pleistocene (as such or with their descendants)” (caloi & palombo, 1995, pag. 395). the italian authors, in view of the first and last historical appearance (fha-lha) recorded at that time, proposed for the hypothetical protogalerian biochronological unit three alternative definitions and temporal extensions. the protogalerian would correspond to the time slice ranging from about 1.4 (pietrafitta lfa, characterised by the presence of microtus ex gr. m. (aiiophaiomys) ruffoi, small-sized rhinoceroses and primitive megacerines) to 8.0 ma (slivia lfa, characterised by the presence of a number of new “galerian” taxa, typically recorded in the early middle pleistocene fauna, and a significant reduction of the villafranchian ones), or alternatively the slivia lfa would be included in the “true” galeriant, or even the biochronological unit would have a wider temporal extension and would include the lfas characterised by the appearance and persistence of voles belonging to the genus microtus (allophaiomys) (caloi & palombo, 1995, pag. 396, fig. 1). all the terms mentioned above were rarely or not used in literature. conversely, since the 90s the use of the term epivillafranchian (regard as a elma intermediated in time and composition between the villafranchian and galerian ones) has more and more being increasing 154 m.r. palombo accompanying faunal elements [e.g. alces carnutorum (=cervalces carnutorum), panthera onca gombaszoegensis (=p. gombazsoegensis), acinonyx pardinensis pleistocaenicus, megantereon cultridens adroveri (=m. withei), puma pardoides, pachycrocuta brevirostris, ursus cf. dolinensis (=ursus ex gr. u. deningeri), canis (xenocyon) lycaonoides (=x. lycaonoides), and canis mosbachensis] found at the site (fig. 3). whether the epivillafranchian as defined by the kahlke (2007, 2009) satisfies or not the characteristic informally recommended by some researches to individuate/define a lma (see below) it is a still open issue. the question arises, indeed, as regards to the minimum requirements a biochronological unit, i.e. a lma, has to meet. 4.2. what is a land mammal age? loose definition, diverse/ambiguous applications and related issues biochronology, the prime conceptual method for relating biologic events to the geologic time scale, is an important concept for geochronology, but neither the biochronological principles nor the criteria required to create a biochronological unit have been discussed in any stratigraphic code. consequently, the biochronological units, in particular lma, still are loosely defined and diversely/ambiguously used (see lindsay, 2003, pag 213, 220). the lmas’ concept was first introduced in the scientific literature about 75 years ago, but no formal definitions of a lma itself has been published to date. it is however clear that bioevents and characteristics of faunal assemblages are of primary importance in creating a lma, while the characteristics of the rocks that produced the fossil record, though to be considered, have a secondary significance. accordingly, a lma has to be regarded as biochronological entities. it is worth noting, however, that the initial attempt to chronologically order the mammalian fauna (i.e. the north american cenozoic mammals) that led to the development of lmas (i.e. north american land mammal ages, nalmas) based on biostratigraphical principles (e.g. osborn & matthew, 1909). the dawn of the lmas’ concept goes back to the first half of the last century, when a seven-member committee of the american paleontological society headed by h.e. wood introduced in a report published in 1941 the “provincial ages” to chronologically order the north american cenozoic mammal assemblages (wood et al., 1941). the report illustrated the conclusions reached by the seven members of the committee, who had appointed in 1939 for presenting a terminology to be used by vertebrate palaeontologists, consistently with the recently published north american stratigraphic guide (ashley et al., 1933). wood et al. (1941) characterised each “provincial age” (i.e. a faunal association of mammals that lived during that age) by listing 1) ‘‘index fossils’’ restricted to that age, 2) first and last appearances of fossils appearing /disappearing during that age, and 3) the so-called ‘‘characteristic fossils’’ that, even known from earlier or later ages, were commonly found at the time of the “provincial age”. 19 “provincial ages” were defined for the north american cenozoic mammalian in literature. at the time when bourdier (1961) first introduced the epivillafranchian (=epi-villafranchién), the meaning was, however, different. bourdier (1961), analysing the geological and palaeontological context of the quaternary deposits of the rhône basin, informally revised the quadripartite subdivision of the villafranchian as introduced by viret (1954) for the french faunas (villafranchien ancien; villafranchien normal inférieur; villafranchien normal supérieur and villafranchien supérieur). the viret’s subdivision was successively simplified, and the resulting villafranchian three partition (early, middle and late villafranchian) is widely used by scientists even today, although meaning and temporal extension attributed by authors to each lower-rank biochronological unit differ (e.g. heintz, 1970 and azzaroli, 1977). the bourdier’s work hypothesis was, conversely, the facto ignored. bourdier (1961) added to viret’s partition two new subdivisions, the proto-villafranchian” for the most archaic faunas (piacentian in age) and the epivillafranchian for some late early pleistocene faunas, such as the durfort (latest early pleistocene, brugal, 1994; palombo & valli, 2004) and saint-cosme lfas. according to bourdier (1961), the durfort lfa typically represents the “warm” epi-villafranchian (= “postvillafranchién inférieur” in bourdier, 1961, tab. 1), corresponding to the “gu ̈nz-mindel” interglacial, and regarded by some authors as roughly correlatable with the “cromerian”, by others with mis 15. bourdier (1961) reported from the site bison (bos vel bison), an advanced mammuthus meridionalis representative “with more tight lamellae, occurrence“, and horses “already similar to equus caballus“(see fig 3 for an updated list). the saint-cosme lfa was selected to represent the “cold” epi-villafranchian (=“post villafranchien supérieur” in bourdier, 1961, tab. 1), corresponding to the ”mindel glaciation”, by some considered roughly correlatable with mis 12. the faunal list reporded by bourdier (1961) includes “equus stenonis, rangifer tarandus? and semi-archaic molluscs”. whether the “cold feature” of the saint-cosme lfa would be confirmed by the attribution of the saint-cosme formation to a glacial phase, although more recent (“recent riss” in bonvalot et al., 1984) is uncertain. a reappraisal of the term epivillafranchian is due to kahlke (2000, 2006, 2007, 2009), who state that the taxonomical composition of the european lfas, ranging in age from the jaramillo submagnetochron to around the end of the early pleistocene, cannot be regarded as a mixture of “older” (villafranchian) and “younger” (galerian) elements. these lfas belong to a “a separate chronostratigraphical unit” (epivillafranchian elma), lasting from about 1, 2 to 0, 9 ma bp. according to the german palaeontologist, the epivillafranchian biochronological unit is epitomized by the untermassfeld lfa (germany), the richest and most diversified among the late early pleistocene lfas known in west european at that time (kahlke, 2007, 2009). accordingly, the kahlke’s epivillafranchian biochronological unit is identified by the “bison menneri eucladoceros giulii-assemblage (i.e. the association of bison menneri, eucladoceros giulii, cervus s.l. nestii vallonnetensis (=dama vallonetensis), capreolus cusanoides, and stephanorhinus hundsheimensis) and 155 late early pleistocene mammalian assemblages from sw europe ............ fauna, only one referring to the pleistocene. this implies a long persistence in time and a wide geographical extent for each unit. a wide temporal and geographical extent also characterises the “mammal horizons”/”life zones” proposed in the conceptual scheme (life zone concept) developed by osborn & matthew (1909) to chronologically order the nw america cenozoic mammalian assemblages. conversely to “provincial ages”, the “life zones” were based on biostratigraphical more than biochronological principles. each life zone, indeed, was regarded as a complex of strata containing a particular assemblage of mammalian taxa. subsequently, the “life zone” concept was differently applied and acquired a biochronological meaning (matthew, 1924). as highlighted by lindsay (2003, pag. 221) “there was precedent in the historical development of nalmas for the application of both biostratigraphical (e.g., the life zones of osborn and matthew, 1909) and biochronological (e.g., the faunal zones of matthew, 1924) concepts”. this semantic and operational confusion, and the diverse, sometimes ambiguous use of the term “lma” depend on different concurring factors. on the one hand, the unclear use of terms such as biozone, a entity related to strata, and biochron, a temporal entity originally introduced to indicate the total time represented by a biozone (williams, 1901), and then sometimes used to indicate the time corresponding to a biochronological unit or the biochronological unit itself. on the other, the fact that the biochronology, in its attempt to define bioevents and chronologically order lfas actually based on the fossil record available in the continental rocks. to make correlations among lfas, and relate biochronological units to the geologic time scale, indeed, we have to refer to appearance/disappearance bioevents that are recorded in strata by biological crostratigraphical markers (sensu lindsay, 2003, pag. 215). biochronology, however, differs from biostratigraphy because the evolutionary patterns and biological events, which regulate over time the dynamic evolutionary processes leading to taxonomical and structural changes of mammalian fauna, are additional important factors to define any biochronological framework. all in all, the appearance and disappearance bioevents and the biological aspect (taxonomical composition and ecological structure) that make a mammalian fauna different from earlier and later faunal complexes recorded in the same geographical area, are the main factors we have to consider to properly define a biocronological unit. following tedford (1970), for instance, a biochronological unit should be regarded as non-overlapping and "ecologically adjusted groups of animals with specif ic geographical l imits and chronologic range" (tedford, 1970, pag. 602). lindsay (2003, pag. 222) defined more explicitly a lma as “a relatively short interval of geologic time that can be recognised and distinguished from earlier and later such units (in a given region or province) by a characterizing assemblage of mammals” de facto, and correctly, releasing any lma by the deposits from which its characteristic taxa were derived. lmas, therefore, have commonly been considered as biological entities (i.e. the natural associations of fossil species), because “the features of life during lmas are of primary concern; the features of the rocks that produced the record are of secondary concern” (lindsay, 2003, pag. 221). although a lma is, therefore, the period during which a peculiar association of mammalian taxa (usually genera according to most of authors), which differ in composition from the groups of taxa found in any other biochronological unit of the same rank, criteria to create it still remain somehow ambiguous. moreover, given that the mean duration of a large mammal species is about 3 ma (i.e. 3.21 ma for larger north american cenozoic mammals) (prothero, 2014), it turns out that shorter the focal time slice and smaller the geographical area are, more difficult is to properly define a lma. a bioevent, for instance, can only be inferred on the basis of the sum of known, local paleobiological data as documented by the fossil record derived from strata (e.g. walsh, 1998; palombo, 2009 and references therein). the actual duration of a large mammal species at large geographical scale may be obscured by analysing faunal change over geological short time in a small geographical area due to some regionalism, which in turn may depend on the local dispersal dynamics and competition. additional drawbacks concern the number of lfas with unclear or imprecise chronostratigraphic constrains, that may be proportionally higher at small than at large geographical scale, and the fact that an analysis performed on short geological time periods sometimes may force to considered taxa at a low taxonomical rank. this increases the problems related to the different taxonomies applied by authors (sometimes irrespectively of the phenotypic plasticity of taxa, according to which a specie/genotype can produce different phenotypes in different environments) that may mask the actual relationships among lfas. 4.3. the epivillafranchian as a biochronological unit in the attempt to characterise the epivillafranchian as a elma following kahlke’s definition (kahlke, 2007, 2009), some difficulties arise. the main problem relates to the confusing/debated taxonomic treatment of a number of taxa (in particular some among those listed by kahlke (2006, 2009) as “accompanying faunal elements”), the disagreement about their phylogeny and chronological range, and the exclusive presence at untermassfeld of a few species that are either only recorded at the site or also dubitatively reported from few other w european sites, and that may be taxonomically or ecologically vicariant of species commonly recorded in other european lfas. the biochronological assessment of the potential epivillafranchian lfas and long distance correlations are therefore problematic, especially if firm chronological constraints are unavailable. in recent times, the discovery of new rich late early pleistocene fossiliferous sites has been changing the already proposed chronological scenarios, and the term “epivillafranchian” seems to have been acquiring a connotation of “time phase” rather than maintaining the biochronological meaning of “a peculiar association of mammalian taxa differing in composition from the groups of taxa found in any other biochronological unit of the same rank”. bellucci et al. (2015, pag. 87) attempted to formal 156 m.r. palombo accompanying the two “index fossils” [see the definition of the epivillafranchian elma proposed by kahlke (2007, 2009) and emended by bellucci et al. (2015)] possibly appeared before the jaramillo submagnetochron (e.g. scrofic suids reported from sima del elefante te9, and megaloceros savini recorded in the cal guardiola cgrd2 lfa), most were already present at about 1.5 ma (e.g. ursus ex gr. u. deningeri, canis ex gr. c. mosbachensis, m. whitei, xenocyon lycaonoides, e. altidens, e. suessenbornensis, maybe stephanorhinus ex gr. s. hundsheimensis, praemegaceros spp., the italian advanced dama-like deer possibly close to d. vallonetensis, and primitive bison representatives), and some others, including long-lasting late villafranchian taxa (i.e. p. gombaszoegensis), were still present during the early middle pleistocene (fig. 2a-b, 3). all things considered, available data suggest that the taxonomical composition and structure of mammalian palaeo-communities had already been changing in sw europe about 1.5-1.3 ma, roughly in the same time span of the first human dispersal towards europe. the first appearance of genus homo, is a bioevent of undeniable relevance to be considered in proposing any biochronological revision of the villafranchian elma. some other bioevents to take into account are the highest local stratigraphical occurrence (hlso in the latest early pleistocene of some carnivores such as those last recorded in some spainish lfas. the dirk-toothed cat meganteron whitei and the pack-hunting canid xenocyon lycaonoides were reported for the last time in the cueva victoria lfa (guadiz-baza basin), dated to about 0.85 (0.98-0.78) ma (gibert et al., 2015). the lycaonlyke canis and and the puma-like cat p. pardoides had their llso in the post-jaramillo early pleistocene evt7 layer of vallparadis estació section (catalonia, spain) (estimated age ranging from 0.99 to about 0.83 ma, see fig. 2b) (alba et al., 2008; madurell-malapeira et al., 2010; duval et al., 2011b, 2015; lozano-fernández et al., 2015). the evidence from sw europe suggests that the chronological range of the so-called epivillafranchian biochronological unit (whatever its biochronological rank could be) should span from about 1.5 ma (llso datum of, among others, homo, x. lycaonoides, c. ex gr. c. mosbachensis, m. whitei, advanced stenonoid horses, praemegaceros, bison) to about 0.85 ma (x. lycaonoides, m. whitei, and p. pardoides hlso datum). in this way and from a biostratigraphical point of view the epivillafranchian would tentatively correspond to a virtual “range-zone”, i.e. the complex of bodies of strata recording the known lower/higher stratigraphical occurrence and the presence in w europe of x. lycaonoides and m. whitei. the appearance/disapprearance of such carnivores would be regarded as biochronological events that acquire the meaning of “biological chronostratigraphical markers”, because “tied to a discrete stratigraphic sequence and related to other stratigraphic sequences and/or chronostratigraphic markers” (cf. lindsay, 2003, pag. 215 for a discussion). nonetheless, several factors (e.g. the debated taxonomic treatment of some taxa, the heterogeneous consistency of the fossil record in space and time particularly as regard the number and richness of lfas -, ize the epivillafranchian as a biochronological unit (european land mammmal age, elma) valid at a european scale by revising and integrating the definition proposed di by kahlke (2006, 2009) “with data from other european sites to better define the faunal turnover occurred at the end of the jaramillo subchron”. the italian authors defined “the epivillafranchian elma” on the basis of appearance bioevents, regarded as valid at a european scale, which would mark respectively the beginning of the epivillafranchian and galerian elmas. accordingly, the epivillafranchian biochronological unit would chronologically extend between about 1.2 and 0.9 ma, i.e. the time slice encompassed between the appearance of p. verticornis (the galerian beginning event sensu gliozzi et al., 1997) and b. menneri and the appearance of c. crocuta (end of epivillafranchian and beginning of the revised galerian) (bellucci et al., 2015, fig. 2, pag. 87). moreover, the authors stated that “together with the dispersal of p. verticornis and b. menneri, the beginning of the epivillafranchian can be placed in correspondence of the diffusion of m. savini and s. scrofa priscus” (bellucci et al., 2015, pag. 87). there is however some uncertainty related to the chronology of bioevents selected as potential biological chronostratigraphical markes by bellucci et al. (2015). in particular, p. verticornis, identified at venta micena by espigares (2010), was present in the barranco leon 5 and fuente nueva 3 lfa. barranco leon 5 is dated to about 1.4 -1.3 ma (duval et al., 2012; toro-moyano et al., 2013), while fuente nueva 3 may be even older (1.50 ± 0.31 ma in álvarez et al., 2015). likewise, the spotted hyaena is recorded for the fist time at atapuerca (north spain), in the td3-4 level of the gran dolina stratigraphic section, one of the most complete with terrestrial deposits recording the early to middle pleistocene transition in western europe. the td3-4 and td5 levels were dated to about 0.99 and 0.94 ma (berger et al., 2008; moreno-garcía, 2011). in addition, the actual phylogenetic relationships of b. menneri (well known from the rich sample of untermassfeld, but poorly doubtfully recorded in other sites) with the early pleistocene bison relatives reported in western europe, and its actual significance as a ‘‘index fossils’’ are unclear. it still is an open question, for instance, whether the untermassfeld bison was a taxon geographically restricted to the western-central europe, and the putative ancestor of “bison voigdstedensis” [a species recorded in the gran dolina lfas and dubiously reported by cuenca-bescós & gracía (2007) in the sima del elefante lfa (te-lru level, atafu1 faunal unit)] as suggested by van der made (2013). furthermore, e. giuli would be already present at about 1.5 in spain at venta micena (van der made, 1999) (see discussion above) and the species is tentatively reported for from sima del elefante te9-level (te-lru stratigraphic sequence) (cuenca-bescós & gracía, 2007). the actual taxonomical identity of the deer, the identification of some remains ascribed to the species as well is its chronological range are debated, although the presence of slender giant deer during the late early pleistocene is undisputable. moreover, some epivillafranchian taxa being part of the “bison mennerieucladoceros giulii-assemblage” or 157 late early pleistocene mammalian assemblages from sw europe ............ taphonomical biases, and the apparent diachronicity/ asynchronicity of llso of some species that dispersed toward western europe during the post-olduvai early villafranchian) make it difficult any attempt to firmly define the “epivillafranchian” as a “formal biochronological unit" (i.e. elma). moreover, it should also be noted that any attempt to assign to the epivillafranchian a elma rank implies a revision of the biochronological meaning and status of the sub-biochrononological units into which the villafranchian elma is currently subdivided. the early villafranchian, for example, may have a stronger significance as potential elma than the epivillafranchian actually has. all in all, several lines of reasoning suggest an informal use of the term epivillafranchian, pending a complete revision of the villafranchian elma, its subdivisions and the biochronological rank each subdivision may have. 5. remarks the structural and taxonomical changes of large mammalian palaeocommunities that led to the establishment of the so-called epivillafranchian fauna has been regarded as linked to the early phase of the climate forcing known as mid-pleistocene revolution (mis 36 mis15-13). nonetheless, an initially slight intensification in the amplitude of climatic oscillations is detectable after the quite long mis 55 interglacial, in particular since about mis 52, though it progressively increased successively from mis 36 onward. the astronomically-forced climate changes and the developing of a new global climatic regime promoted alterations and latitudinal displacements in european terrestrial biomes and was a critical factor in driving faunal turnovers, removing keystone species, exerting great influence on dispersal and dispersion of mammalian across and between continents, in turn triggering new competition-coevolution dynamics that contributed to either the extirpation of some taxa or to the appearances of others by anagenetic evolution in some phyletic lineages. large mammals did not generally move in multispecies waves of dispersal, rather each species changed the limits of its range depending on the suitability of environmental conditions in respect to its own environmental tolerances and ecological flexibility. therefore, taxa answered to climate stimuli at a dissimilar pace and in a different way. some large mammals, for instance, had already extended the limits of their range to and/or are recorded for the first time in sw europe at about 1.5 ma. some others appeared shortly before or during the early jaramillo submagnetochron, few just after the jaramillo-matuyama palaeomagnetic inversion, some were reported from a number of lfas, others only from small geographical areas or in a single lfa (fig. 2, 3). although few diachronous appearances permit to follow the displacement/enlargement of the limit of a species’ range, the majority of llso (especially but not only that of rare species) documented in the available fossil record are asynchronous at least across the sw european region. it is a challenging task understanding which among several factors (e.g. among others the different impact of global climate changes in different geographical settings, differences in species resilience and variability in competition and predation patterns within local faunal complexes, inadequate availability of long stratigrafical sequences, taphonomical and sampling biases) might have caused the asynchronous appearance of several taxa across w europe in the post -olduvai early pleistocene. as a result, large mammal assemblages may substantially differ in taxonomical composition at regional and local scale, making correlations problematic and the compelling definition of any biochronological unit uncertain. based on available data it would be suggested, as working hypothesis, that the “epivillafranchian biochronological unit” (whatever its biochronological rank could be) should span from about 1.5 ma (e.g. homo, x. lycaonoides, c. ex gr. c. mosbachensis, m. whitei, advanced stenonoid horses, praemegaceros, bison, llso datum) and about 0.85 ma (x, lycaonoides, m. whitei, p. pardoides hlso datum). several lines of reasoning, however, recommend a great caution in formalising this biochronological unit. as said above, a number of factors hamper this attempt. to answer the question on the chronological meaning and the temporal range of the “epivillafranchian” as well as be able to make correlations between distant sequences, the central challenges are: i) to remove disagreements about the taxonomy and phylogeny of some “epivillafranchian taxa”; ii) to scrutinise the factors that cause the restricted geographical distribution of a few others; iii) to appraise the significance of heterogeneous consistency of the fossil record in space and time (e.g. number and richness of lfas); iv) to remove taphonomical biases that may affect the chronological reliability of local first/last appearances especially as regard to rare species; v) to improve the chronostratigraphical constrain of various lfa and understand and eliminate some inconsistencies in absolute geochronological dating provided for others. moreover, any attempt to properly define the biochronological rank of the “epivillafranchian biochronological unit” cannot avoid a reappraisal of the villafranchian elma and of the status and significance of its subdivisions. all in all, available evidence seems to be still inadequate to ascertain whether the late early pleistocene lfas (between 1.5/1.3 to 0.9-0.8 ma) form or not a welldefined biochronological unit (i.e. an ecologically adjusted groups of animals with specific geographical limits and chronologic range, tedford, 1970), and what may be its biochronological rank. concluding, several lines of reasoning suggest an informal use of the term epivillafranchian, pending a complete revision of the villafranchian elma, its subdivisions and the relative rank each subdivision (i.e. the early villafranchian comparatively to a hypothetical epivillafranchian) may have. acknowledgements we wish to thank the two anonymous reviewers for critically reading the previous version of the manuscript. this research was funded by italian murst (sapienza university 2014, project c26a14bnrm led by m.r. palombo) 158 m.r. palombo mammalia) en el registro euroasiático (fonelas p1, cuenca de guadix, españa). in: arribas a. (ed.), vertebrados del plioceno superior terminal en el suroeste de europa: fonelas p-1 y el proyecto fonelas cuadernos del museo geominero, n. 10. instituto geológico y minero de españa, madrid, 2008, 461-473. arribas a., garrido g., viseras c., soria j.m., pla s., solano j.g., garcés m., beamud e., carrión j.s. (2009) a mammalian lost world in southwest europe during the late pliocene. plos one, 4(9), e7127. ashley g.h., cheney m.g., galloway j.j., gould c.n., hares c.j., howell b.f., levorsen a.i., miser h.d., moore r.c., reeside j.b., rubey w.w., stanton t.w., stose g.w., twenhofel w.h. (1933) classification and nomenclature of rock units. geological society of america bulletin, 44, 423-459. azzaroli a. (1977) the villafranchian stage in italy and the plio-pleistocene boundary. giornale geologia, 41(2), 61-79. azzaroli a. (1983) quaternary mammals and the “end villafranchian” dispersal event a turning point in the history of eurasia. palaeogeography, palaeoclimatology, palaeoecology, 44, 117-139. azzaroli a. (1995) the “elephant-equus” and the “endvillafranchian” events in eurasia. in e. s. vrba, g.h. denton, t.c. partridge l.h. burckle (eds.), paleoclimate and evolution, with emphasis on human origins. yale university press, new haven, london, 311-318. azzaroli a., de giuli c., ficcarelli g., torre, d. (1988) late pliocene to early mid-pleistocene mammals in eurasia: faunal succession and dispersal events. palaeogeography, palaeoclimatology, palaeoecology, 66, 77-100. badgle c., finarelli j. a. (2013) diversity dynamics of mammals in relation to tectonic and climatic history: comparison of three neogene records from north america. paleobiology, 39(3), 373-399. barnosky a.d. (2005) effects of quaternary climatic change on speciation in mammals. journal of mammalian evolution, 12(1-2), 247-264. barnosky a.d., hadly e.a., bell c.j. (2003) mammalian response to global warming on varied temporal scales. journal of mammalogy, 84(2), 354-368. barnosky a.d., kraatz b.p. (2007) the role of climatic change in the evolution of mammals. bioscience, 57(6), 523-532. bellucci l., sardella r., rook l. (2015) large mammal biochronology framework in europe at jaramillo: the epivillafranchian as a formal biochron. quaternary international, 389, 84-89. belmaker m. (2002) first evidence of the presence of theropithecus sp. in the southern levant. israel j. zool. 48 (2), 165. berger g.w., pérez-gonzález a., carbonell e., arsuaga j.l., bermúdez de castro j.m., ku t.l. (2008) luminescence chronology of cave sediments at the atapuerca paleoanthropological site, spain. journal of human evolution, 55 (2), 300-311 berger w.h., jansen e. (1994) mid-pleistocene climate shift: the nansen connection. in johannesreferences abbazzi l. (2010) la fauna de cérvidos de barranco león y fuente nueva-3. in: martínez-navarro b., agusti j., toro mojano i. (eds), ocupaciones humanas en el pleistoceno inferior y medio de la cuenca de guadix-baza. junta de andalucía, consejería de cultura, 273-290. abbazzi l. (2004) remarks on the validity of the generic name praemegaceros portis 1920, and an overview on praemegaceros species in italy. rendiconti lincei, 15(2), 115-132. aguilar j.p., antoine p.o., bonnet a., crochet j.y., michaux j. (2009) compléments à la faune pléistocène de durfort (gard, sud de la france). bulletin de la société d'histoire naturelle de toulouse, 145, 55-58. agustí j. (1986) synthèse biostratigraphique du pliopléistocène de guadix-baza 4 (province de granada, sud-est de l’espagne). geobios, 19, 505510. agustí j., moya-sola s. (1998) the early pleistocene mammal turnover in spain: evidence against an 'end-villfranchian' event. in: van kolfschoten t.h., gibbard p.l. (eds), the dawn of the quaternary. (proceedings of the seqs-euromam symposium 1996), mededelingen nederlands instituut voor toegepaste wetenschappen tno, 60, 513-520. alba d.m., aurell-garrido j., madurell j., gómez m., moyà-solà s., beràstegui x. (2008) paleontologia i geologia del jaciment del pleistocè inferior de vallparadís (terrassa, vallès occidental). trib. arqueol., 2007, 29-44. alberdi m.t. (2010) estudio de los caballos de los yacimientos de fuente nueva-3 y barranco león-5 (granada). in: toro i., martínez-navarro b., agustí j. (eds), ocupaciones humanas en el pleistoceno inferior y medio de la cuenca de guadix-baza. arqueología monografías, junta de andalucía, consejería de cultura, 291-306. alberdi m.t., palombo m.r. (2013) the late early to early middle pleistocene stenonoid horses from italy. quaternary international. 288, 25-44 álvarez c., parés j.m., granger d., duval m., sala r., toro i. (2015) new magnetostratigraphic and numerical age of the fuente nueva-3 site (guadixbaza basin, spain). quaternary international 389, 224-234. argant j., bonifay m. f. (2011) les coprolithes de hyène (pachycrocuta brevirostris) de la couche 2 du site villafranchién de ceyssaguet (lavoûte-surloire, haute-loire, france): analyse pollinique et indications paléoenvironnementales. quaternaire. revue de l'association française pour l'étude du quaternaire, 22(1), 3-11. arnold l. j., demuro m., parés j.m., arsuaga j.l., aranburu a., de castro j.m.b., carbonell e. (2014) luminescence dating and palaeomagnetic age constraint on hominins from sima de los huesos, atapuerca, spain. journal of human evolution, 67, 85-107. arribas a., garrido g. (2008) los representantes más antiguos del género capra (bovidae, artiodactyla, 159 late early pleistocene mammalian assemblages from sw europe ............ sen et al. (eds.), the polar oceans and their role in shaping the global environment, washinghton dc, agu geophysical monograph, 84, 295-311. blain h.a., bailon s., agustí j. (2008) amphibians and squamate reptiles from the latest early pleistocene of cueva victoria (murcia, southeastern spain, sw mediterranean): paleobiogeographical and paleoclimatic implications. geologica acta, 6, 345-361. blasco r., rosell j., van der made j., rodríguez j., campeny g., arsuaga j.l., bermúdez de castro j.m., carbonell e. (2011) hiding to eat: the role of carnivores in the early middle pleistocene from the td8 level of gran dolina (sierra de atapuerca, burgos, spain). journal of archaeological science, 38 (1-2), 3373-3386 blois j.l., zarnetske p.l., fitzpatrick m.c., finnegan s. (2013) climate change and the past, present, and future of biotic interactions. science, 341 (6145), 499-504. bon m., piccoli g., sala b. (1992) la fauna pleistocenica della breccia di slivia (carso triestino) nella collezione del museo civico di storia naturale di trieste. atti del museo civico di storia naturale di trieste, 44, 33-51. bonifay m.f. (1971) carnivores quaternaires du sudest de la france. mémoire du muséum national d’histoire naturelle paris. 21, 43-377. bonifay m.f. (1981) les praemegaceros du pleistocene moyen de la grotte de l'escale à saintestève-janson (bouches-du-rhône). bull. ass. fr. et. quat., 3/4, 109-120. bonifay m.f. (1991) archéologie du comportement: remarques sur l'apport des faunes de grands mammifères au pléistocène ancien. actes du congrès national des sociétés savantes. commission de pré-et protohistoire, 114, 111-113. bonifay m.f. (1978) faunes de transition du pléistocène moyen de france. bulletin du museum d’anthropologie et préhistoire de monaco, 22, 515. bonvalot j., courel l., senac p. (1984) etude sèdimentologique du remplissage plio-pléistocène de la bresse. gèologie de la france, 3, 197-220 boscaini a (2014) plio-pleistocene lynxes from the iberian peninsula. taxonomy and phylogenetic relationships with the extant and fossil species. master dissertation, universitat autonoma de barcelona and universitat de barcelona, pp. 106. boudier f. (1961) le bassin du rhône au quaternaire. géologie et préhistoire. tome i. texte. centre national de la recherche scientifique, paris, 364. bourguignon l., crochet j.y., capdevila r., ivorra j., antoine p.o., agusti j., barsky d., blain h.a., boulbes n., claude j., cochard d., de weyer l., filoux a., firmat c., lozano-fernández i., magniez p., pelletier m., ríos j., testu a., valensi p. (2014) the early pleistocene site of bois-deriquet (lézignan-la-cébe, hérault, france): stratigraphy, dating, fauna, and lithics. abstracts xvii world uispp congress 2014, burgos, 1-7 september, a2a the first peopling of europe, burgos, 23-24. bourguignon l., crochet j.y., capdevila r., ivorra j., antoine p.o., agustí j., barsky d., blain h.a., boulbes n., bruxelles l., claude j. (2015) boisde-riquet (lézignan-la-cèbe, hérault): a late early pleistocene archeological occurrence in southern france. quaternary international, 393 24 -40. breda, m., marchetti, m. (2005) systematical and biochronological review of plio-pleistocene alceini (cervidae; mammalia) from eurasia. quaternary science reviews, 24(5), 775-805. brugal j.p. (1994) le bison (bovidae, artiodactyla) du pléistocène moyen ancien de durfort (gard, france). bulletin du muséum national d'histoire naturelle. section c, sciences de la terre, paléontologie, géologie, minéralogie, 16(2-4), 349-381. brugal j.p., boudadi-maligne m. (2011) quaternary small to large canids in europe: taxonomic status and biochronological contribution. quaternary international, 243 (1), 171-182. bukhsianidze m. (2005) the fossil bovidae of dmanisi, phd, dissertation. the international doctorate “environmental, humans and compartmental dynamics” xvi cycle 2001-2004, university of ferrara, pp. 192. bukhsianidze m., vekua, a. (2006) capra dalii nov. sp. (caprinae, bovidae, mammalia) at the limit of pliopleistocene from dmanisi (georgia). courierforshungsinstitut senckenberg, 256, 159. caloi l., palombo m.r. (1995) late early pleistocene mammal faunas of italy: biochronological problems. il quaternario, 8 (2), 391-402. carbonell e., bermúdez de castro j.m., parés j.m., pérez-gonzález a., cuenca-bescós g., ollé a., mosquera m., huguet r., van der made j., rosas a., sala r., vallverdú j., garcía n., granger d.e., martinón-torres m., rodríguez x.p., stock g.m., vergès j.m., allué e., burjachs f., cáceres i., canals a., benito a., díez c., lozano m., mateos a., navazo m., rodríguez j., rosell j., arsuaga j.l. (2008) the first hominin of europe. nature, 452, 465-469. chaline j. (1972) les rongeurs du pléistocène moyen et supérieur de france 3 (systématique, biostratigraphie, paléoclimatologie). cahiers de paléontologie, 4 c.n.r.s., paris, 410, 5 chaline j. (1987) arvicolid data (arvicolidae, rodentia) and evolutionary concepts. evolutionary biology, 21, 237-310. clark p., archer d., pollard d., blum j.d., rial j.a., brovkin v., mix a.c., pisias n.g., roy m. (2006) the middle pleistocene transition: characteristics, mechanisms, and implications for long-term changes in atmospheric pco2. quaternary science reviews, 25, 3150-3184. colbert, j., baguette m., benton t.g., bullock j.m. (eds) (2012) dispersal ecology and evoution, oxford university press, oxford uk, pp. 462. collinge s. e., parfitt s. a., lister a. m. (2010) metric analysis of ungulate mammals in the early middle pleistocene of britain, in relation to taxonomy and biostratigraphy: i: rhinocerotidae and bovidae. quaternary international, 228(1), 136-156. 160 m.r. palombo 119. cuenca-bescós g., gracía n. (2007) biostratigraphic succession of the early and middle pleistocene mammal faunas of the atapuerca cave sites (burgos, spain). courier-forschungsinstitut senckenberg, 259, 99-110. cuenca-bescós g., rofes j., lópez-garcía j.m., blain h-a., rabal-garcés r., sauqué v., arsuaga j.l., bermúdez de castro j-m., carbonell e. (2011) the small mammals of sima del elefante (atapuerca, spain) and the first entrance of homo in western europe quaternary international, 285 (8), 28-35 dabney j., knapp m., glocke i., gansauge m.t., weihmann a., nickel b., valdiosera c., garcía n., pääbo s., arsuaga j.l., meyer m., (2013) complete mitochondrial genome sequence of a middle pleistocene cave bear reconstructed from ultrashort dna fragments. proceedings of the national academy of sciences, 110(39), 1575815763. davies t.j., buckley l.b., grenyer r., gittleman j.l. (2011) the influence of past and present climate on the biogeography of modern mammal diversity. philosophical transactions of the royal society of london b: biological sciences, 366(1577), 25262535. de giuli c., masini f., torre d. (1987) the latest villafranchian faunas in italy: the pirro nord fauna (apricena, gargano). palaeontographia italica, 74, 56-62. de lumley h.d., kahlke h.d., moigne a.m., moulle p.e. (1988) les faunes de grands mammifères de la grotte du vallonnet, roquebrune-cap-martin, alpes-maritimes. l'anthropologie, 92(2), 465-495. delson e. (1993) theropithecus fossils from africa and india and the taxonomy of the genus. in: jablonski n.g. (ed.), theropithecus: the rise and fall of a primate genus. cambridge university press, cambridge, 157-189. di stefano g., petronio c. (1992) nuove osservazioni su cervus elaphus acoronatus beninde del pleistocene europeo. bollettino della societa` paleontolologica italiana, 31(3), 295-315. duval m., aubert m., hellstrom j., grün r. (2011a) high resolution la-icp-ms mapping of u and th isotopes in an early pleistocene equid tooth from fuente nueva-3 (orce, andalusia, spain). quaternary geochronology, 6(5), 458-467. duval m., falguères c., bahain j.j., grün r., shao q., aubert m., hellstrom, j., dolo j.m., agusti j., martínez-navarro b., palmqvist p., toro-moyano i. (2011b) the challenge of dating early pleistocene fossil teeth by the combined uranium serieselectron spin resonance method: the venta micena palaeontological site (orce, spain). journal of quaternary science, 26(6), 603-615. duval m., falguères c., bahain j.j., grün r., shao q., aubert m., dolo j.m., agusti j., martínez-navarro b., palmqvist p., toro-moyano i. (2012) on the limits of using combined u-series/esr method to date fossil teeth from two early pleistocene archaeological sites of the orce area (guadix-baza coltorti m., albianelli a., bertini a., ficcarelli g., laurenzi, m. a., napoleone g., torre d. (1998) the colle curti mammal site in the colfiorito area (umbria-marchean apennine, italy): geomorphology, stratigraphy, paleomagnetism and palynology. quaternary international, 47, 107-116. combourieu-nebout n., bertini a., russo-ermolli e., peyron o., klotz s., montade v., fauquette s., allen j.r.m., fusco f., goring s., huntley b. (2015) climate changes in the central mediterranean and italian vegetation dynamics since the pliocene. review of palaeobotany and palynology, 2018, 127-147. crégut-bonnoure e. (2002) les ovibovini, caprini et ovini (mammalia, artiodactyla, bovidae, caprinae) du plio-pléistocène dʼeurope: systématique, évolution et biochronologie. thèse de doctorat d’etat és sciences. université de lyon i, pp. 430. crégut-bonnoure e. (2005) nouvelles données paléogéographiques et chronologiques sur les caprinae (mammalia, bovidae) du pléistocène moyen et supérieur d’europe. munibe antropolarkeol, 57, 205-219. crégut-bonnoure e. (2007) apport des caprinae et antilopinae (mammalia, bovidae) à la biostratigraphie du pliocène terminal et du pléistocène d’europe. quaternaire. revue de l'association française pour l'étude du quaternaire, 18(1), 7397. crégut-bonnoure e., dimitrijevic, v. (2006) megalovis balcanicus sp. nov. and soergelia intermedia sp. nov.(mammalia, bovidae, caprinae), new ovibovini from the early pleistocene of europe. revue de paléobiologie, 25(2), 723-773. crochet j.y., welcomme j.l., ivorra j., ruffet g., boulbes n., capdevila r., claude j., firmat c., métais g., michaux j., pickford m. (2009) une nouvelle faune de vertébrés continentaux, associée à des artifacts dans le pléistocène inférieur de l’hérault (sud de la france), ver 1, 57 ma. comptes rendus palevol., 8, 725-736. croitor r. (2006) taxonomy and systematics of largesized deer of the genus praemegaceros portis, 1920 (cervidae, mammalia). courierforshungsinstitut senckenberg, 256, 91-116. croitor r. (2009) systematical position and evolution of the genus arvernoceros (cervidae, mammalia) from plio-pleistocene of eurasia. muz. olteniei craiova. studii şi comunic ąri. ştiin ţele natur, 25, 379-381. croitor r., bonifay m.f. (2001) étude préliminaire des cerfs du gisement pleistocène inférieur de ceyssaguet (haute-loire) paleo, 13, 129-144. croitor r., kostopoulos, d.s. (2004) on the systematic position of the large-sized deer from apollonia, early pleistocene, greece. paläontologische zeitschrift, 78(1), 137-159. cuenca-bescós g., rofes j., lópez-garcía m., blain h.a., de marfà r., galindo-pellicena m.a., bennàsar -serra m.l., melero-rubio m., arsuaga j.l, bermúdez de castro j.m., carbonell. e. (2010) biochronology of spanish 17 quaternary small vertebrate faunas. quaternary international, 212, 109 161 late early pleistocene mammalian assemblages from sw europe ............ basin, spain). quaternary research, 77(3), 482491. duval m., bahain j.j., falguéres c., gracía j., guilarte v., grün r., martínez k., moreno d., shao, q., voinchet p. (2015) revisiting the esr chronology of the early pleistocene hominin occupation at vallparadís (barcelona, spain). quaternary international, 389, 213-223. eisenmann v., kuznetsova t. (2004) early pleistocene equids (mammalia, perissodactyla) of nalaikha, mongolia, and the emergence of modern equus linnaeus, 1758. geodiversitas, 26(3), 535-561. espigares m.p. (2010) análisis y modelización del contexto sedimentario y los atributos tafonómicos de los yacimientos pleistocénicos del borde nororiental de la cuenca de guadix-baza. ph. d. dissertation, university of granada (spain), fernández m.h., cantalapiedra j.l., cano a.r.g. (2015) plio-pleistocene climatic change had a major impact on the assembly and disassembly processes of iberian rodent communities. palaeobiodiversity and palaeoenvironments, 95, 387404. ferràndez-cañadell, c., ribot f., gibert l. (2014) new fossil teeth of theropithecus oswaldi (cercopithecoidea) from the early pleistocene at cueva victoria (se spain). journal of human evolution 74, 55-66. fortelius m., eronen j.t., kaya f., tang h., raia p., puolamäki k. (2014) evolution of neogene mammals in eurasia: environmental forcing and biotic interactions. annual review of earth and planetary sciences, 42, 579-604. franzen j.l., gliozzi e., jellinkek t., scholger r., weidenfeller m. (2000) die spätpleistozäne fossillagerstätte dorn-dürkheim 3 und ihre bedeutung für die rekonstruktion der entwicklung des rhenishen flusssystems. senkenbergiana lethaea, 80 (1), 305-353. gracía n., arsuaga, j.l. (2001) les carnivores (mammalia) des sites du pléistocène ancien et moyen d'atapuerca (espagne). l’anthropologie, 105(1), 83-93. garcıa n., arsuaga j.l., torres t. (1997) the carnivore remains from the sima de los huesos middle pleistocene site (sierra de atapuerca, spain). journal of human evolution, 33(2), 155-174. geraads d. (1990) contribution des cervidés à la chronologie des débuts de l'occupation humaine en europe occidentale. quaternaire, 1(3), 167-174. geraads d. (2010) biogeographical relationships of pliocene and pleistocene north-western african mammals. quaternary international, 212(2), 159168. ghezzo e., boscain, a., madurell-malapeira j., rook l. (2014) lynx remains from the pleistocene of valdemino cave (savona, northwestern italy), and the oldest occurrence of lynx spelaeus (carnivora, felidae). rendiconti lincei, 26, 87-95. gibert j., ribot f., gibert l., leakey m., arribas a., martínez-navarro b. (1995) presence of the cercopithecid genus theropithecus in cueva victoria (murcia, spain). journal of human evolution, 28, 487-493. gibert l., scott g. (2015) etad del yacimiento de cueva victoria y su relacion con otros yacimientos de la peninula ibérica. in gibert l., ferrandezcanadell c., (eds), paleontología y geología de cueva victoria, cartagena, españa. mastia, 1113, 85-100 gingerich p.d. (2003) mammalian responses to climate change at the paleocene-eocene boundary: polecat bench record in the northern bighorn basin, wyoming. special papers, geological society of america, 463-478. gliozzi e., abbazi l., ambrosetti p., argenti, p., azzaroli a., caloi l., capasso barbato l., di stefano g., esu d., ficcarelli g., girotti o., kotsakis t., masini f., mazza p., mezzabotta c., palombo m.r., petronio c., rook l., sala b., sardella r., zanalda e., torre d. (1997) biochronology of selected mammals, molluscs, ostracods from the middle pliocene to the late pleistocene in italy. the state of the art. rivista italiana di paleontologia e stratigrafia, 103 (3), 369-388. grossouvre a.d., stehlin h.g. (1912) les sables de rosières, près saint-florent (cher) bulletin de la société géologique de france, 4, 194-212. guérin c. (1990) biozones or mammal units? methods and limits in biochronology. in: lindsay, e.h., fahlbush, v., mein, p. (eds.), european neogene mammalian chronology. nato asi series a life sciences, 180. plenum press, new york, 119-130. guérin c., dewolf y., lautridou j. p. (2003) révision d'un site paléontologique célèbre: saint-prest (chartres, france). geobios, 36(1), 55-82. guérin c., faure m. (1997) the wild boar (sus scrofa priscus) from the post-villafranchian lower pleistocene of untermassfeld. in kahlke, r.d. et al. (eds), das pleistozän von untermassfeld bei meiningen (thüringen), teil 1. monogr. röm.-germ. zentralmus. mainz, 40(1), 375-384. hassanin a., ropiquet a., couloux a., cruaud c. (2009) evolution of the mitochondrial genome in mammals living at high altitude: new insights from a study of the tribe caprini (bovidae, antilopinae). journal of molecular evolution, 68(4), 293-310. head m.h., gibbard, p.o. (eds) (2005) the landocean early-middle pleistocene transitions: evidence. geological society of london special publication 251. the geological society publishing house, bath uk, pp. 336. hedberg h.d. (ed) (1976) international stratigraphic guide. john wiley & sons, new york, pp. 200. heintz e. (1970) les cervidés villafranchiens de france et d'espagne. mémoires du muséum national d’histoire naturelle de paris c 22, pp. 206. hemmer h. (2001) die felidae aus dem epivillafranchium von untermassfeld. monographien des römisch-germanischen zentralmuseum, 40, 699782. hemmer h., kahlke r.d., vekua a.k. (2011) -the cheetah acinonyx pardinensis (croizet et jobert, 1828) s.l. at the hominin site of dmanisi (georgia) a potential prime meat supplier in early pleistocene ecosystems. quat. sci. rev., 30, 2703-2714. 162 m.r. palombo ont. italiana, 40(2), 217-223. koufos g.d. (2014) the villafranchian carnivoran guild of greece: implications for the fauna, biochronology and paleoecology. integrative zoology, 9(4), 444-460. koufos g.d., kostopoulos d.s., sylvestrou i.a. (1997) equus apolloniensis n.sp. (mammalia, equidae) from the latest villafranchian locality of apollonia, macedonia, greece. paleontologia i evoluciò, 3031, 49-76. kurtén b. (1968) pleistocene mammals of europa. weidenfeld and nicolson, london, pp. 317. kurtén b., poulianos a. (1977) new stratigraphic and faunal material from petralona cave with special reference to the carnivora. anthropos athens, 4, 47-130. langlois a. (2002) présence de panthera gombaszoegensis kretzoi, 1938 à la grotte xiv (cénac-et-saint-julien, dordogne). paléo. revue d'archéologie préhistorique, 14, 213-220. lawler j.j., shafer s.l., white d., kareiva p., maurer e.p., blaustein a.r., bartlein p.j. (2009) projected climate-induced faunal change in the western hemisphere. ecology, 90(3), 588-597. leroy s.a.g., arpe k., mikolajewicz u. (2011) vegetation context and climatic limits of the early pleistocene hominin dispersal in europe. quaternary science reviews, 30(11), 1448-1463. lindsay e.h. (1990) the setting. in: lindsay e.h., fahlbush v., mein p. (eds), european neogene mammalian chronology. nato asi series a life sciences, 180. plenum press, new york, 1-14. lindsay e.h. (2003) chapter 10: chronostratigraphy, biochronology, datum events, land mammal ages, stage of evolution, and appearance event ordination. bulletin of the american museum of natural history, 212-230. lindsay e.h., tedford, r.h. (1990) -. development and application of land mammal ages in north america and europa, and comparison. in: lindsay e.h., fahlbusch, w., mein, p. (ed), european neogene mammalian chronology. nato asi series a life sciences, 180. plenum press, new york, 601-624. lisiecki l, raymo m. (2005) a pliocene-pleistocene stack of 57 globally distributed benthic 18o records. paleoceanography, 20, pa1003. lister a.m., parfitt s.a., owen f.j., collinge s.e., breda m. (2010) metric analysis of ungulate mammals in the early middle pleistocene of britain, in relation to taxonomy and biostratigraphy: ii: cervidae, equidae and suidae. quaternary international, 228(1), 157-179. lister a.m., sher a.v., van essen h., wei g. (2005) the pattern and process of mammoth evolution in eurasia. quaternary international, 126-128, 49-64. lister a.m. (1993) the stratigraphical significance of deer in the cromer forest-bed formation. journal of quaternary science, 8 (2), 95-108. lo bello p. (1988) géochronologie par la méthode 39ar -40ar de ponces quaternaires contaminées: exemple des ponces du mont-dore (massif central, france). utilisation d’un laser continu pour la datation des minéraux individuels. thèse de doctorat hemmer h., kahlke r.d., keller t. (2008) cheetahs in the middle pleistocene of europe: acinonyx pardinensis (sensu lato) intermedius (thenius, 1954) from the mosbach sands (wiesbaden, hesse, germany). neues jahrb. geol. paläontol. abh., 249, 345-356 hooijer d.a. (1959) fossil mammals from jisr banat yaqub, south of lake huleh, israel. bulletin of the research council of israel, section g: geosciences, 8(4), 177-199. hughes j.k., elton s., o'regan h.j. (2008) theropithecus and ‘out of africa’dispersal in the pliopleistocene. journal of human evolution, 54(1), 43-77. kahlke h.d. (1997) die cerviden-reste aus dem unterpleistozän von untermassfeld. in kahlke, r.d. et al. das pleistozän von untermassfeld bei meiningen (thüringen), teil 1. monogr. röm.germ. zentralmus. mainz 40(1), 181-275 kahlke h.d. (2001) neufunde von cervidenresten aus dem unterpleistozän von untermassfeld. in kahlke, r.d. et al. (eds), das pleistozän von untermassfeld bei meiningen (thüringen), teil 2. monogr. röm.-germ. zentralmus. mainz 40(2), 185-195 kahlke r.d. (2000) the early pleistocene (epivillafranchian) faunal site of untermassfeld (thuringia, central germany) synthesis of new results. early humans at the gate of europe. eraul, 92, 123 -138. kahlke r.d. (2006) untermassfeld a late early pleistocene (epivillafranchian) fossil site near meiningen (thuringia, germany) and its position in the development of the european mammal fauna. british archaeological reports, international series, 1578, 1-144. kahlke r.d. (2007) late early pleistocene european large mammals and the concept of an epivillafranchian biochron. courier forschungsinstitut senckenberg, 20(259), 265-278. kahlke r.d. (2009) les communautés de grands mammifères du pléistocène inférieur terminal et le concept d'un biochrone épivillafranchien. quaternaire, 20(4), 415-427. kahlke r.d., garcía n., kostopoulos d.s., lacombat f., lister a.m., mazza p.p., spassov n. titov v.v. (2011) western palaearctic palaeoenvironmental conditions during the early and early middle pleistocene inferred from large mammal communities, and implications for hominin dispersal in europe. quaternary science reviews, 30 (11), 1368-1395. konidaris g.e., tourloukis v., kostopoulos d.s., thompson n., giusti d., michailidis d., koufos g., harvati k. (2015) two new vertebrate localities from the early pleistocene of mygdonia basin (macedonia, greece): preliminary results. comptes rendus palevol, 14(5), 353-362. kostopoulos d.s. (1997) the pilo-pleistocene artiodactyls (vertebrata, mammalia) of macedonia 1. the fossiliferous site apollonia-1, mygdonia basin of greece. geodiversitas, 19(4), 845-875. koufos g. (2001) the villafranchian mammalian faunas and biochronology of greece. boll. soc. pale 163 late early pleistocene mammalian assemblages from sw europe ............ de l’université de nice, pp. 122. lo bello p., feraud g., hall c.m., york d., lavina p., bernat m. (1987) 40ar39ar step-heating and laser fusion dating of a quaternary pumice from neschers, massif central, france: the defeat of xenocrystic contamination. chemical geology: isotope geoscience section, 66(1), 61-71. lozano-fernández i., cuenca-bescós g., blain h.a., lópez-garcía j.m., agustí j. (2013) mimomys savini size evolution in the early pleistocene of south-western europe and possible biochronological implications. quaternary science reviews, 76, 96-101. lozano-fernández i., lópez-garcía j.m., aurell-garrido j., alba d.m., madurell-malapeira j. (2015) data review on the small mammals from the late early pleistocene of vallparadís estació layer evt7 (vallès-penedès basin, ne iberian peninsula): biochronological and palaeoenvironmental implications. quaternary international, 389, 159-166. madurell-malapeira j., minwer-barakat r., alba d., garcés m., gómez m., aurellgarrido j., rosmontoya s., moyà-solà, s., berástegui x. (2010a) the vallparadís section (terrassa, iberian peninsula) and the latest villafranchian faunas of europe. quaternary science reviews, 29, 39723982. madurell-malapeira j., alba d. m., espigares m.p., vinuesa v., palmqvist p., martínez-navarro b., moyà-solà s. (2015) were large carnivorans and great climatic shifts limiting factors for hominin dispersals? evidence of the activity of pachycrocuta brevirostris during the mid pleistocene revolution in the vallparadís section (vallès-penedès basin, iberian peninsula), quaternary international (in press), doi:10.1016/j.quaint.2015.07.040 madurell-malapeira j., alba d. m., moyà-solà s., aurellgarrido j. (2010b) the iberian record of the puma-like cat puma pardoides (owen, 1846) (carnivora, felidae). comptes rendus palevol, 9 (1), 55-62. madurell-malapeira j., ros-montoya s., espigares m.p., alba d.m., aurell-garrido j.a. (2014) villafranchian large mammals from the iberian peninsula: paleobiogeography, paleoecology and dispersal events. journal of iberian geology, 40(1), 141155. magri d., palombo m.r. (2013) early to middle pleistocene dynamics of plant and mammal communities in south west europe. quaternary international, 288, 63-72. marciszak a. (2014) presence of panthera gombaszoegensis (kretzoi, 1938) in the late middle pleistocene of biśnik cave, poland, with an overview of eurasian jaguar size variability. quaternary international, 326, 105-113. martínez-navarro b., madurell-malapeira j., rosmontoya s., espigares, m.p., medin t., hortola p., palmqvist p. (2015) the epivillafranchian and the arrival of pigs into europe. quaternary international, 389, 131-138. martínez-navarro b., rook l. (2003) gradual evolution in the african hunting dog lineage systematic implications. comptes rendus palevol, 2(8), 695702. martínez-navarro b., ros-montoya s., espigares m.p., palmqvist p. (2011) presence of the asian origin bovini, hemibos sp. aff. hemibos gracilis and bison sp., at the early pleistocene site of venta micena (orce, spain). quaternary international, 243 (1), 54-60. martínez-navarro b., sardella r., rook l., bellucci l., ros-montoya s. (2012) first occurrence of soergelia (ovibovini, bovidae, mammalia) in the early pleistocene of italy. quaternary international, 267, 98-102. masini f., palombo m.r., rozzi r. (2013) a reappraisal of the early to middle pleistocene italian bovidae. quaternary international, 288, 45-62. masini f., sala b. (2007) large-and small-mammal distribution patterns and chronostratigraphic boundaries from the late pliocene to the middle pleistocene of the italian peninsula. quaternary international, 160 (1), 43-56. maslin m.a., ridgwell a.j. (2005) mid-pleistocene revolution and the ‘eccentricity myth’. geological society, london, special publications, 247(1), 1934. maslin, m.a, ridgwell a.j. (2005) mid-pleistocene revolution and the ‘eccentricity myth’. geological society, london, special publications, 247(1), 1934. maul l.c., markova a.k. (2007) similarity and regional differences in quaternary arvicolid evolution in central and eastern europe. quaternary international, 160(1), 81-99. maul l.c., parfitt s.a. (2010) micromammals from the 1995 mammouth excavation at west runton, norfolk, uk: morphometric data, biostratigraphy and taxonomic reappraisal. quaternary international, 228 91-115. 15 mayhew d.f. (2013) west european arvicolid evidence of intercontinental connections during the early pleistocene. quaternary international, 284, 62-73. mazo a.v., sesé c., ruiz bustos a., peña j.a. (1985) geología y paleontología de los yacimientos pliopleistocenos de huéscar (depresión de guadixbaza, granada). estudios geológicos 41, 467493. mcclymont e.l., sosdian s.m., rosell-melé a., rosenthal y. (2013) pleistocene sea-surface temperature evolution: early cooling, delayed glacial intensification, and implications for the mid-pleistocene climate transition. earth-science reviews, 123, 173-193 menéndes e. (1987) cérvidos del yacimiento del pleistoceno inferior de venta micena_2, orce (granada, españa), paleontol. evolucio, 1, 129181. meon h., ballesio r., guérin c., mein p. (1979) corrélations biostratigraphiques dans le néogène du sud-est de la france. ann. géol. pays hellén., 807 -816. minwer-barakat r., madurell-malapeira j., alba d. m., aurell-garrido j., de estevan-trivigno s., moyàsolà s. (2011) pleistocene rodents from the tor 164 m.r. palombo bailon s. (2005) l'environnement animal des premiers habitants de l'europe méditerranéenne: les grands mammifères contemporains de l'homme du vallonnet, données taxonomiques et biostratigraphiques pour la deuxième moitie du pléistocène inférieur. bar international series, 1364, 105-113. musil r. (2001) die equiden-reste aus dem unterpleistozän von untermassfeld. in: kahlke, r.-d (ed.), das pleistozän von untermassfeld bei meiningen (thüringen), teil 2. monograph. römish-german. zentralmus., 40 (2), 633-658 napoleone g., albianelli a., azzaroli a., bertini a., magi m., mazzini m. (2003) calibration of the upper valdarno basin to the plio-pleistocene for correlating the apennine continental sequences. il quaternario, italian journal of quaternary sciences 16 (1bis), 159-195. nocchi g., sala b. (1997) the fossil rabbit from valdemino cave (borgio verezzi, savona) in the context of western europe oryctolagini of quaternary. palaeovertebrata, 26(1-4), 167-187. nomade s., pastre j.f., guillou h., faure m., guérin c., delson e., debard e., voinchet p., messager e. (2014) 40ar/39ar constraints on some french landmark late pliocene to early pleistocene large mammalian paleofaunas: paleoenvironmental and paleoecological implications, quaternary geochronology 21, 2-15. o'regan h.j. (2008) the iberian peninsula-corridor or cul-de-sac? mammalian faunal change and possible routes of dispersal in the last 2 million years. quaternary science reviews, 27(23), 2136-2144. olive f. (2006) evolution des grands carnivores au plio pléistocène en afrique et en europe occidentale. l'anthropologie, 110(5), 850-869. osborn h.f., matthew w.d. (1909) cenozoic mammal horizons of western north america. u.s. geological survey bulletin, 361, 1-138. pacheco f.g., santiago a., gutiérrez j.m., lópezgarcía j.m., blain h.a., cuenca-bescós g., van der made j., caceres i., garcía, n. (2011) the early pleistocene paleontological site in the sierra del chaparral (villaluenga del rosario, cádiz, southwestern spain. quaternary international, 243 (1), 92-104. palmqvist p., arribas a., martínez-navarro b. (1999) ecomorphological study of large canids from the lower pleistocene of southeastern spain. lethaia, 32(1), 75-88. palmqvist p., gonzález-donoso j.m., de renzi m. (2014) rectilinear evolution in arvicoline rodents and numerical dating of iberian early pleistocene sites. quaternary science reviews, 98, 100-109. palombo m.r. (1995) gli elefanti del pliocene superiore e del pleistocene dell’italia centrale peninsulare. studi geol. camerti, vol. spec. b (1994), 447457. palombo m.r. (2009) biochronology of terrestrial mammals and quaternary subdivisions: a case study of large mammals from the italian peninsula. il quaternario, italian journal of quaternary sciences, 22, 291-306. rent 20 de vallparadís section (terrasa, northeastern spain) and biochronological 21 implications. journal of vertebrate paleontology, 31, 849-865. moigne a.m., palombo m.r., belda v., heriech-briki d., kacimi s., lacombat f., de lumley m.a., moutoussamy j., rivals f., quilès j., testu a. (2006) les faunes de grands mammifères de la caune de l'arago (tautavel) dans le cadre biochronologique des faunes du pléistocène moyen italien. l'anthropologie, 110(5), 788-831. mol d., post k., reumer j.w.f., de vos j., laban c. (2003) het gat: preliminary note on a bavelian fauna from the north sea with possibly two mammoth species. deinsea, 9, 253-266. mol d., post k., reumer j. w., de vos j., laban c. (2003) het gat: preliminary note on a bavelian fauna from the north sea with possibly two mammoth species. advances in mammoth research. deinsea, 9, 253-266. moncel m. h., despriée j., voinchet p., tissoux h., moreno d., bahain j. j., courcimault g., falguères c. (2013) early evidence of acheulean settlement in northwestern europe-la noira site, a 700 000 year-old occupation in the center of france. plos one 8(11), e75529. montoya p., alberdi m.t., barbadillo l.j., morales j., murelaga x., peñalver e., robles f., ruiz bustos a., sánchez a., sanchiz b., soria d., szyndlar z. (2001) une faune très diversifiée du pléistocène inférieur de la sierra de quibas (province de murcia, espagne). comptes rendus de l’académie des sciences paris, 332, 387-393. morales j., soria d., soto e. (1987) los carnívoros del pleistoceno medio de atapuerca. el hombre fósil de ibeas y el pleistoceno de la sierra de atapuerca i. junta de castilla y león, consejería de cultura y bienestar social, soria, 135-152. moreno garcía d. (2011) datation par esr de quartz optiquement blanchis (esr-ob) de la région de atapuerca (burgos, espagne). application au site préhistorique de gran dolina (contexte karstique) et aux systèmes fluviatiles quaternaires de l'arlanzón et l'arlanza.". phd dissertation. universitat rovira i virgili. departament d'història i història de l'art, tarragona, spain, pp. 305. mosquera m., ollé a., saladié p., cáceres i., huguet r., rosas a., villalaín j. j., carrancho a., bourlès d., braucher r., pineda a., vallverdú j. (2015) the early acheulean technology of barranc de la boella (catalonia, spain). quaternary international, 393, 95-111. moullé p.e., echassoux a., martínez-navarro b. (2004) ammotragus europaeus: une nouvelle espèce de caprini (bovidae, mammalia) du pléistocène inférieur à la grotte du vallonnet (france). comptesrendus palevol, 3, 663-673. moullé p.e., lacombat f., echassoux a. (2006) apport des grands mammifères de la grotte du vallonnet (roquebrune-cap-martin, alpes-maritimes, france) à la connaissance du biochronologique de la seconde moitié du pléistocene inférieur d’europe. l’anthropologie, 110, 837-849. moullé p.e., echassoux a., lacombat f., desclaux e., 165 late early pleistocene mammalian assemblages from sw europe ............ palombo m.r. (2014) deconstructing mammal dispersals and faunal dynamics in sw europe. quaternary science reviews, 96, 50-71. palombo m.r. (2015a) discrete dispersal bioevents of large mammals in southern europe in the postolduvai early pleistocene: a critical overview. quaternary international (in press). doi:10.1016/ j.quaint.2015.08.034 palombo m.r. (2015b) to what extent could functional diversity be an useful tool in inferring ecosystem responses to past climate changes? quaternary international. ( in press) doi:10.1016/ j.quaint.2015.07.069 palombo m.r., ferretti m.p. (2005) elephant fossil record from italy: knowledge, problems, and perspectives. quaternary international, 126-128, 107136. palombo m.r., milli s. (2011) mammalian fossil recod, depositional setting, and sequence stratigraphy in the middle upper pleistocene of roman basin. il quaternario, italian journal of quaternary sciences, 23 (2), 243-248. palombo m.r., valli a.m.f. (2004) remarks on the biochronology of mammalian faunal complexes from the pliocene to the middle pleistocene in france. geologica romana, 37(2003-2004), 145163. palombo m.r., azanza b., alberdi m.t. (2003) italian mammal biochronology from latest miocene to middle pleistocene: a multivariate approach. geologica romana 36 (2000-2002), 335-368. palombo m.r., alberdi m.t., azanza b., giovinazzo c., prado j.l., sardella r. (2009) how did environmental disturbances affect carnivoran diversity? a case study of the plio-pleistocene carnivora of the north-western mediterranean. evolutionary ecology, 23(4), 569-589. palombo m.r., mussi m., agostini a., barbieri m., di canzio e., di rita f., fiore i., iacumin p., magri d., speranza f., tagiacozzo a. (2010) human peopling of italian intramontane basins: the early middle pleistocene site of pagliare di sassa (l’aquila, central italy). quaternary international, 223-224, 170-178. parés j. m., duval m., arnold l. j. (2013) new views on an old move: hominin migration into eurasia. quaternary international 295, 5-12. parfitt s. a., barendregt r. w., breda m., candy i., collins m. j., coope g. r., durbidge p., field m.h., lee j.r., lister a.m., mutch r., penkman k.e.h., preece r.c., james r., stringer c.b., symmons r., whittaker j.e., wymer j.j., stuart a. j. (2005) the earliest record of human activity in northern europe. nature, 438(7070), 10081012. parfitt s.a., ashton n.m., lewis s. g., abel r.l., coope g. r., field m.h., gale r., hoare p.g., larkin n.r., lewis m.d., karloukovski v., maher b.a., peglar s.m., preece, r.c., whittaker j.e., stringer c.b. (2010) early pleistocene human occupation at the edge of the boreal zone in northwest europe. nature, 466(7303), 229-233. petronio c., marcolini f. (2013) mammal biochronology at the end of late villafranchian (early pleistocene): pirro faunal unit. palaeontographica abteilung a, 298(1-6), 183-191. petrucci m., cipullo a., martínez-navarro b., rook l., sardella r. (2013) the late villafranchian (early pleistocene) carnivores (carnivora, mammalia) from pirro nord (italy) palaeontographica abteilung a, 298(1-6), 113-145. pons-moya j. (1987) -. los carnivoros (mammalia) de venta micena (granada, espana) paleontologia i evolucio memoir special 1, 109-128. prideaux g.j., roberts r.g., megirian d., westaway k.e., hellstrom j.c., olley j.m. (2007) mammalian responses to pleistocene climate change in southeastern australia. geology, 35(1), 33-36. prothero d.r. (2004) did impacts, volcanic eruptions, or climate change affect mammalian evolution?. palaeogeography, palaeoclimatology, palaeoecology, 214(3), 283-294. prothero d.r. (2012) cenozoic mammals and climate change: the contrast between coarse-scale versus high-resolution studies explained by species sorting. geosciences, 2(2), 25-41. prothero d.r. (2014) species longevity in north american fossil mammals. integrative zoology, 9(4), 383 -393. qiu z.x. (2006) quaternary environmental changes and evolution of large mammals in north china. vertebrata palasiatica, 44, 109-132. raynal j.p., magoga l., bulle t., guadelli j.l., maigne s. (1996) quelle préhistoire ancienne en basse auvergne et velay?. in: tuffreau, a., (éd.), l'acheuléen dans l'ouest de l'europe, actes du colloque de saint riquier, 1989, lille, publications du cerp 4, 115-127. roebroeks w., van kolfschoten t.h. (1995) the earliest occupation of europe: a reappraisal of artefactual and chronological evidence. in roebroeks w., van kolfschoten t. (eds.), the earliest occupation of europe. proceedings of the european science foundation workshop at tautavel (france) (1993). university of leiden press, leiden, 297-315. ropiquet a., hassanin, a. (2005) molecular phylogeny of caprines (bovidae, antilopinae): the question of their oriin and diversification during the miocene. journal of zoological systematics and evolutionary research, 43(1), 49-60. sadori l., bertini a., combourieu-nebout n., kouli k., lippi m.m., roberts n., mercuri a.m. (2013) palynology and mediterranean vegetation history. flora mediterranea, 23, 141-156. sala b., masini f. (2007) late pliocene and pleistocene small mammal chronology in the italian peninsula. quaternary international, 160(1), 4-16. sardella r. (1998) the plio-pleistocene old world dirk -toothed cat megantereon ex gr. cultridens (mammalia, felidae, machairodontinae), with comments on taxonomy, origin and evolution. neues jahrbuch fur geologie und palaontologieabhandlungen, 207(1), 1-36. sardella r., petrucci m. (2012) the earliest middle pleistocene crocuta crocuta (erxleben, 1777) at casal selce (rome, italy). quaternary interna 166 m.r. palombo 358. toro-moyano i., barsky d., cauche d., celiberti v., grégoired s., lebegued f., moncel m.h., de lumley h. (2011) the archaic stone tool industry from barranco león and fuente nueva 3, (orce, spain): evidence of the earliest hominin presence in southern europe quaternary international, 243 (1), 80-91. torres t., cobo r., garcìa alonso p., grun r., hoyos m., julia r., llamas j., soler v. (1995) evolucion del sistema fluvial jarama-lozoya-guadalix durante el plioceno final y el cuaternario. geogaceta, 17, 46-48 tsoukala, e. (2004) the early pleistocene carnivores (mammalia) from ceyssaguet (haute-loire). paléo, 16, 193-242. turner a., antón m. (1996) the giant hyaena, pachycrocuta brevirostris (mammalia, carnivora, hyaenidae). geobios, 29(4), 455-468. tzedakis p. c., hooghiemstra h., pälike h. (2006) the last 1.35 million years at tenaghi philippon: revised chronostratigraphy and long-term vegetation trends. quaternary science reviews, 25(23), 3416 -3430. valli a.m.f., caron j.b., debard e., guérin c. (2006) le gisement paléontologique villafranchien terminal de peyrolles (issoire, puy-de-dôme, france): résultats de nouvelles prospections. geodiversitas, 28, 297-317. vallverdú j., saladié p., rosas a., huguet r., cáceres i., mosquera m., gracía-tabernero a., estalrrich a., lozano-fernández i., pineda-alcalá a., carrancho a., villalaín j.j., bourlès d., braucher r., lebatard a., vilalta j., esteban-nadal m., bennàsar m.l., bastir m., lópez-polín l., ollé, a., vergés, j.m., ros-montoya, s., martínez-navarro, b., garcía, a., martinell, j., expósito i., burjachs f., agustí j., carbonell e. (2014) age and date for early arrival of the acheulian in europe (barranc de la boella, la canonja, spain). plos one, 9(7), e103634. van dam j.a. (2003) european neogene mammal chronology: past, present and future. deinsea, 10, 85-95. van der made j. (1998) ungulates from gran dolina (atapuerca, burgos, spain)[la faune des ongulés de la séquence de gran dolina (atapuerca, burgos, espagne)]. quaternaire, 9(4), 267-281. van der made j., carlos calero j.a., mancheno, m.á. (2008) new material of the goat capra? alba from the lower pleistocene of quibas (spain); notes on sexual dimorphism, stratigraphic distribution and systematics. bollettino della società paleontologica italiana, 47, 13-23. van der made j. (1999) ungulates from atapuercatd6. journal of human evolution, 37(3/4), 389413 van der made j. (2001) les ongulés d'atapuerca. stratigraphie et biogéographie. l'anthropologie, 105 (1), 95-113. van der made j. (2013) first description of the large mammals from the locality of penal, and updated faunal lists for the atapuerca ungulates-equus tional, 267, 103-110. schloss c.a., nuñez t.a., lawler j.j. (2012) dispersal will limit ability of mammals to track climate change in the western hemisphere. proceedings of the national academy of sciences, 109(22), 8606-8611. sher a. (1997) an early quaternary bison population from untermassfeld: bison menneri sp. nov. in kahlke r.d. (ed.), das pleistozuan von untermussfeld bei meiningen (thüringen), teil 1. rudolf habelt verlag, bonn, 101-180. siori m.s., sala b. (2007) the mammal fauna from the late early biharian site of castagnone (northern monferrato, piedmont, nw italy). geobios, 40(2), 207-217. siori m.s., boero a., carnevale g., colombero s., delfino m., sardella r., pavia m. (2014) new data on early pleistocene vertebrates from monte argentario (central italy). paleoecological and biochronological implications. geobios, 47(6), 403418. sotnikova m.v. (2001) remains of canidae from the lower pleistocene site of untermassfeld. in: kahlke, r.d. (ed.), das pleistozan von untermassfeld bei meiningen (thüringen), teil 2. rudolf habelt verlag, bonn, 607-632. spassov n. (2003) the plio-pleistocene vertebrate fauna in south-eastern europe and the megafaunal migratory waves from the east to europe. revue de paléobiologie, 22, 197-229. spassov n. (2011) acinonyx pardinensis (croizet et jobert) remains from the middle villafranchian locality of varshets (bulgaria) and the pliopleistocene history of the cheetahs in eurasia. estud. geol., 67, 245-253. stehlin h.g. (1910) remarques sur les faunules de mammifères des couches éocènes et oligocènes du bassin de paris. bulletin de la societe geologique de france, 9 (4), 488-520. steninger f.f., piller w.e. (eds) (1999) empfehlungen (richtlinien) zur handhabung der stratigraphischen nomenklatur. courier forschungsinstitut senckenberg, 209, 1-19. stewart, j.r. (2009) the evolutionary consequence of the individualistic response to climate change. journal of evolutionary biology, 22(12), 23632375. suc j., popescu, s. (2005) pollen records and climatic cycles in the north mediterranean region since 2.7 ma. geological society, london, special publications, 247(1), 147-154. tedford r.h. (1970) principles and practices of mammalian geochronology in north america. in proceedings of the north american paleontological convention, 1 (part f), 666-703. thenius e. (1954) die caniden (mammalia) aus dem alquartär von hundsheim (niederösterreich) nebst bemerkungen zur stammesgeschichte des gattun cuon. neues jahrbuch fur geologie und paläontologie, 99 (2), 230-286. thouveny n., bonifay e. (1984) new chronological data on european plio-pleistocene faunas and hominid occupation sites. nature, 308(5957), 355 167 late early pleistocene mammalian assemblages from sw europe ............ ms. received: february 8, 2016 final text received: may 19, 2016 altidens, bison and human dispersal into western europe. quaternary international, 295, 36-47. van der made j. (2015) the latest early pleistocene giant deer megaloceros novocarthaginiensis n. sp. and the fallow deer dama cf. vallonnetensis from cueva victoria (murcia, spain). in gibert l., ferrandez-canadell c., (eds), geología y paleontología de cueva victoria. mastia, 11-13, 269-323. van der made j., dimitrijević v. (2015) eucladoceros montenegrensis n. sp. and other cervidae from the lower pleistocene of trlica (montenegro) quaternary international, 389, 90-118. van der made j., tong h.w. (2008) phylogeny of the giant deer with palmate brow tines megaloceros from west and sinomegaceros from east eurasia. quaternary international, 179(1), 135-162. van der meulen a.j. (1973) middle pleistocene smaller mammals from the monte 16 peglia (orvieto, italy) with special reference to the phylogeny of microtus 17 (arvicolidae, rodentia. quaternaria, 17, 1144. vislobokova i.a. (2011) historical development and geographical distribution of giant deer (cervidae, megacerini). paleontological journal, 45(6), 674688. vislobokova i.a. (2013) morphology, taxonomy, and phylogeny of megacerines (megacerini, cervidae, artiodactyla). paleontological journal, 47(8), 833950. walker m.j., lópez-martínez m., carrión-garcía j.s., rodríguez-estrella t., san-nicolás del-toro m., schwenninger j.l., lópez-jiménezm a., ortegarodrigáñezm j., haber-uriartem m., polocamacho j.l., garcía-torre j., campillo-boj m., avilés-fernández a., zack, w. (2013) cueva negra del estrecho del río quípar (murcia, spain): a late early pleistocene hominin site with an “acheulo-levalloiso-mousteroid” palaeolithic assemblage. quaternary international, 294, 135159. walsh s.l. (1998) fossil datum and paleobiological event terms, paleontostratigraphy, chronostratigraphy, and the definition of land mammal “age” boundaries. journal of vertebrate paleontology, 18(1), 150-179. williams h.s. (1901) the discrimination of time values in geology. journal of geology 9(7), 570-585. woodburne m.o. (1977) definition and characterization in mammalian chronostratigraphy. journal paleontology, 51, 220-234. woodburne m.o., goin f.j., bond m., carlini a.a., gelfo j.n., lópez g.m., iglesias a., zimicz a.n. (2014) paleogene land mammal faunas of south america; a response to global climatic changes and indigenous floral diversity. journal of mammalian evolution, 21(1), 1-73. zachos j., pagani m., sloan l., thomas e., billups k. 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can be opened with acrobat and adobe reader 5.0 and later.) >> /namespace [ (adobe) (common) (1.0) ] /othernamespaces [ << /asreaderspreads false /cropimagestoframes true /errorcontrol /warnandcontinue /flattenerignorespreadoverrides false /includeguidesgrids false /includenonprinting false /includeslug false /namespace [ (adobe) (indesign) (4.0) ] /omitplacedbitmaps false /omitplacedeps false /omitplacedpdf false /simulateoverprint /legacy >> << /addbleedmarks false /addcolorbars false /addcropmarks false /addpageinfo false /addregmarks false /convertcolors /converttocmyk /destinationprofilename () /destinationprofileselector /documentcmyk /downsample16bitimages true /flattenerpreset << /presetselector /mediumresolution >> /formelements false /generatestructure false /includebookmarks false /includehyperlinks false /includeinteractive false /includelayers false /includeprofiles false /multimediahandling /useobjectsettings /namespace [ (adobe) (creativesuite) (2.0) ] /pdfxoutputintentprofileselector /documentcmyk /preserveediting true /untaggedcmykhandling /leaveuntagged /untaggedrgbhandling /usedocumentprofile /usedocumentbleed false >> ] >> setdistillerparams << /hwresolution [2400 2400] /pagesize [612.000 792.000] >> setpagedevice base unità a limiti inconformi utilizzate per la cartografia dei depositi quaternari nei fogli carg della sicilia nord-occidentale cipriano di maggio, mauro agate, antonio contino, luca basilone & raimondo catalano dipartimento di geologia e geodesia, università degli studi, palermo, e-mail: dimaggio@unipa.it riassunto: di maggio c. et al., unità a limiti inconformi utilizzate per la cartografia dei depositi quaternari nei fogli carg della sicilia nord-occidentale. (it issn 0394-3356, 2009). sono riportati i risultati di uno studio sui depositi quaternari del settore settentrionale siciliano compreso tra trapani e cefalù. dettagliati rilevamenti di campagna e analisi stratigrafiche condotti in questa area nell’ambito del progetto carg hanno consentito di definire diverse unità a limiti inconformi, del rango di sintema e subsintema, che costituiscono la sintesi regionale degli affioramenti quaternari della sicilia nord-occidentale. sono state riconosciute e studiate numerose successioni di terreni di ambiente da continentale a marino costituite da: depositi fluviali, paralici e marini (conglomerati monogenici o poligenici, areniti e/o peliti sciolte o variamente cementate), accumuli eolici (sabbie e arenarie quarzose o carbonatiche, a stratificazione e laminazione incrociata), terreni colluviali (suoli e detriti rimaneggiati con allineamenti di ciottoli), depositi di falda (detriti sciolti o stratificati e cementati), concrezioni calcaree (travertini, croste calcitiche e depositi di grotta) e macereti di frana. i depositi continentali, tipici di ambienti dominati da erosione, affiorano in piccoli e sottili lembi relitti, spesso discontinui e incompleti; i depositi marini e paralici, caratteristici di ambienti a prevalente sedimentazione, si rinvengono in bacini locali e costituiscono affioramenti più estesi e potenti. il rinvenimento di superfici di discontinuità di importanza regionale che limitano inferiormente e superiormente i corpi rocciosi, ha consentito la proposizione di sette distinti sintemi che ricoprono un periodo di tempo che va dal pleistocene inferiore all’olocene. le discontinuità, marcate a volte da paleosuoli, sono rappresentate da superfici di erosione subacquea (piattaforme di abrasione marina e falesie) o subaerea (superfici, ripe, canali, solchi e cavità prodotti da erosione idrica, processi gravitativi o fenomeni carsici), da superfici di non deposizione o, nel caso del limite superiore, dall’attuale superficie topografica. le datazioni e le correlazioni di depositi e limiti inconformi sono state rese possibile da alcuni elementi vincolanti quali: a) presenza di forme fossili significative; b) datazioni isotopiche di depositi desunte dalla letteratura geologica; c) continuità fisica di alcune superfici di discontinuità; d) significato paleoambientale o paleoclimatico di depositi e superfici di discontinuità; e) rapporti geometrici fra superfici di discontinuità e/o corpi rocciosi. abstract: di maggio c. et al., unconformity-bounded stratigraphic units of quaternary deposits mapped for the carg project in northern and western sicily. (it issn 0394-3356, 2009). quaternary deposits of nw sicily mapped for the carg project (geological survey of italy) during detailed geologic and geomorphologic surveys are made up of: a) fluvial, coastal or marine deposits (mono or polygenic conglomerates, arenites or lutites variously cemented, with plane, inclined or cross-bedded stratification/lamination); b) aeolian deposits (quartzous or carbonate sands/sandstones, with cross-bedded stratification/lamination); c) colluvial terrains (reworked soils and breccias variously cemented, in some case laminated, with stone lines); d) scree slopes (breccias or stratified slope deposits – éboulis ordonné); e) carbonate speleothems (travertines, calcretes and cave deposits); e) landslide debris. lower and upper boundaries of the quaternary rocks consist of unconformity surfaces (marked by palaeosols at places), such as: wave cut platforms and cliffs; gullies and rills; erosion surfaces due to sheet erosion or sheet flood; stream channels, fluvial erosion scarps and fluvial erosion/depositional surfaces; separation or depletion surfaces due to mass movement; non depositional surfaces; topographic surfaces. the detection of some unconformity surfaces of regional extent allowed us to define seven main synthems; they have been mapped in several geologic 1:50.000 sheet maps. the marsala synthem is a lower pleistocene 2-80 m thick body of marine/ coastal conglomerates, arenites and lutites, with abundant corals, algae, bryozoa, mollusca (arctica islandica,chlamys septemradiata), benthic foraminifera and planktonic foraminifera (hyalinea baltica, globorotalia truncatulinoides excelsa); its lower boundary is a marine abrasion surface cut into pre-quaternary rocks. the piana di partinico synthem is made up of 1-5 m thick marine/coastal conglomerates and arenites located on a number of marine terrace surfaces related to sea high stand phases of middle pleistocene (oxygen isotope stages – oiss 17-7); these rocks appear correlatable with 1-3 m thick continental deposits (colluvial terrains and travertines) rich in fossil vertebrates belonging to the early middle pleistocene elephas falconeri sicilian faunal complex; its lower boundary is a wave cut platform carved into marsala synthem or prequaternary rocks. the polisano synthem is 1-10 m thick aeolian sandstones and sands with intercalations of breccias talus; the body deposited in coastal, perched or barrier dune, contains rare terrestrial gastropods shells, late middle pleistocene in age (ois 6); its lower boundary is a non-depositional surface at the top of the piana di partinico synthem or older rocks. the barcarello synthem encompasses 1-2 m thick marine/coastal conglomerates and arenites with a rich warm-temperate “senegalese fauna” including strombus bubonius; they belong to two orders of marine terrace (oiss 5e and 5c or 5a) and laterally pass into 1-5 m thick, welded colluvial deposits; the latter are composed of both lutitic terrains (reworked soil) and breccias with angular rock fragments (reworked scree and sediment) in a abundant silt or fine-grained clay matrix (reworked soil) containing terrestrial mollusc shells and fossil vertebrates of the upper pleistocene elephas mnaidriensis sicilian faunal complex; their age is correlated with the ois 5; the lower boundary of synthem is a marine abrasion surface laterally extending to a continental erosion surface; the latter is cutting the polisano synthem or older rocks. the imera settentrionale synthem is made up of middle – upper pleistocene 1-3 m thick fluvial deposits located on river terrace surfaces lying between about 5 and 100 meters above the valley bottom; its lower boundary is a stream erosion surface. the raffo rosso synthem is composed of 1-2 m thick coastal dune aeolian sandstones and sands, 1-7 m thick colluvial or gravitational deposits with fossil mammals of the late upper pleistocene pianetti and castello sicilian faunal complex, 2-10 m thick stratified slope deposits of the last glacial climatic event (oiss 4-2); the lower boundary is a non-depositional surfaces at the top of the barcarello/imera settentrionale synthems or older rocks. the capo plaia synthem is made up of coastal to continental deposits of the last glacial climatic event end – holocene age (oiss 2-1); its lower boundary is formed by variously originated erosion or non-depositional surfaces; the upper boundary is the present day topographic surface. significant environmental changes during the quaternary, directly or indirectly due to tectonic movements (block faulting or uplifting) and/or climatic fluctuations in their turn triggering erosion / depositional processes, appear to originate both unconformity surfaces of regional extent and deposits. parole chiave: stratigrafia, sintema, quaternario, sicilia nord-occidentale, italia. keywords: stratigraphy, synthem, quaternary, nw sicily, italy. il quaternario italian journal of quaternary sciences 22(2), 2009 345-364 346 c. di maggio et al. 1. introduzione i depositi quaternari della sicilia nord-occidentale sono stati oggetto di numerosi studi. gignoux (1913; 1926) per primo segnala depositi marini e di spiaggia del pleistocene inferiore e superiore. fabiani (1941), tongiorgi & trevisan (1953), ottman & picard (1954), bonifay & mars (1959), buccheri (1966) e ruggieri et al. (1968) concentrano le loro attenzioni sui terreni tirreniani affioranti in diverse località delle coste della sicilia occidentale. sulla base del contenuto paleontologico, ruggieri (1967; 1971; 1973), ruggieri & sprovieri (1975; 1983), ruggieri et al. (1975a), ruggieri et al. (1975b) e ruggieri et al. (1984) forniscono schemi stratigrafici dei depositi pleistocenici marini della sicilia nord-occidentale, corredati da una proposta di suddivisione del pleistocene inferiore nei piani santerniano, emiliano e siciliano. la comprensione delle relazioni esistenti fra terrazzi marini e depositi marino-continentali mediante l’ausilio di analisi paleontologiche e termoluminescenza o di studi integrati a carattere geomorfologico, paleontologico e geologico-strutturale, consente a mauz et al. (1997) e di maggio et al. (1999) di ricostruire l’evoluzione stratigrafica e morfotettonica di alcune aree della sicilia nord-occidentale, dal pleistocene medio all’attuale. numerosi sono gli studi paleontologici sui depositi continentali a vertebrati (scinà, 1831; de gregorio, 1925; vaufrey, 1929; brugal, 1987; burgio et al., 1989; burgio & fiore, 1997), in cui il riconoscimento di specie continentali contribuisce alla definizione di schemi biocronologici basati su dati stratigrafici, aminostratigrafici e geomorfologici (belluomini & bada, 1985; burgio & cani, 1988; bada et al., 1991; bonfiglio & burgio, 1992; di maggio et al., 1999; bonfiglio et al., 2003). gli studi stratigrafici sui depositi continentali sono esigui e limitati a poche e semplici segnalazioni di alcuni corpi sedimentari (gignoux, 1913; tongiorgi & trevisan, 1953; ottmann & picard, 1954; ruggieri & milone, 1974). locali o parziali ricostruzioni di successioni di terreni continentali e dei rapporti esistenti fra queste successioni e depositi marini e di spiaggia sono prodotte da hugonie (1979; 1982), di maggio (1997), agnesi et al., (1998), cottignoli et al. (2002), bonfiglio et al. (2004) e contino (2005; 2007). tecniche e metodi per studiare la stratigrafia dei terreni continentali e le loro relazioni con i depositi paralici e marini, finalizzate alla ricostruzione delle geometrie dei corpi rocciosi e delle successioni sedimentarie, sono offerte dal progetto nazionale di cartografia geologica alla scala 1:50.000 (progetto carg). nell’ambito di questo progetto, particolare attenzione è rivolta al rilevamento dei depositi continentali plio-quaternari, per i quali è espressamente raccomandato l’util izzo di unità stratigrafiche a l imiti inconformi (“unconformity-bounded stratigraphic units”, ubsu); il loro impiego ha trovato campo d’applicazione anche nel caso di depositi marini debolmente deformati. si tratta di unità stratigrafiche formali costituite da corpi rocciosi delimitati al letto e al tetto da ben definite e identificabili superfici di discontinuità. corpi rocciosi e discontinuità devono possedere importanza regionale affiorando, anche se in maniera discontinua o frammentaria, in aree alquanto estese. la loro unità base è il sintema (chang, 1975) che può comprendere due o più subsintemi e/o unità litostratigrafiche; a loro volta due o più sintemi possono costituire un supersintema (issc, 1994). per ciò che concerne il rilevamento dei fogli geologici della sicilia nord-occidentale interessati dal progetto carg, recenti e dettagliati studi hanno consentito di definire, attraverso il riconoscimento di superfici di discontinuità di importanza regionale, sette ubsu del rango di sintema, che ricoprono un intervallo di tempo compreso fra il pleistocene inferiore e l’olocene; esse rappresentano una sintesi complessiva delle successioni di depositi quaternari. 2. l’area studiata l’area studiata ricopre l’intero settore settentrionale della sicilia centro occidentale, dai monti di trapani alle madonie (figg. 1, 2). nelle regioni centrali e orientali del settore in esame sono presenti tre grandi e compatti gruppi montuosi carbonatici (da est verso ovest madonie, monti di termini imerese e monti di palermo), separati fra loro da grandi vallate a sviluppo n-s, incise in depositi argillosi, attraversate dai fiumi imera settentrionale e torto (tra le madonie e i monti di termini imerese) e dal fiume eleuterio (al limite fra i monti di termini imerese e i monti di palermo); le regioni occidentali e centro-meridionali sono caratterizzate da rilievi carbonatici isolati (monte bonifato, monte inici, dorsale n-s della penisola di capo san vito, monte erice e montagna grande nelle aree occidentali; dorsali e-o di monte kumeta e rocca busambra lungo le propaggini meridionali dell’area indagata), cui si frappongono aree collinari argillose o, lungo la fascia costiera, grandi aree pianeggianti. queste ultime si rinvengono, in modo discontinuo, anche lungo la fascia costiera dei settori centrali ed orientali. nel mediterraneo centro-occidentale, la sicilia costituisce un segmento di catena che si sviluppa lungo il limite tra la placca africana e quella europea, collega le maghrebidi africane con la calabria e gli appennini e si estende dalla sardegna fino alla piattaforma pelagiana (canale di sicilia; fig. 1). dopo la fase orogenica alpina paleogenica, i movimenti compressivi più importanti di questo settore del mediterraneo sono dovuti alla subduzione della crosta adriatico-ionica. in questo quadro la collisione del blocco sardo-corso con il margine continentale africano (bellon et al., 1977; channellet al., 1979; dercourt et al., 1986) è considerata comunemente come la causa primaria per la gran parte della deformazione compressiva nella catena sudappenninica-siciliana (catalano & d’argenio, 1978; catalano et al, 1996 con bibliografia). dal miocene superiore, con la fine della rotazione del blocco sardo-corso, parte dell’orogene alpinoappenninico venne interessato da processi distensivi, associati con il progressivo arretramento del piano di subduzione, immergente verso no, della placca adriatico-ionica al di sotto della calabria, responsabili della formazione ed evoluzione del bacino tirrenico meridionale (malinverno & ryan, 1986; rehault et al, 1987; faccenna et al., 1996; gueguen et al., 1998). il complesso collisionale della sicilia e del suo prolungamento offshore (catalano et al., 1996) è caratterizzato da tre elementi tettonici principali: a) un’area di avampaese, affiorante nella sicilia sudorientale e presente nel canale di sicilia a sud di sciacca. la successione sedimentaria autoctona 347unità a limiti inconformi utilizzate per la cartografia dei depositi ... ricopre un basamento cristallino africano ed è costituita da circa 7 km di carbonati di piattaforma e di scarpata-bacino del triassico-liassico, di carbonati pelagici del giurassico-eocene e di depositi clastici di piattaforma aperta del terziario (patacca et al., fig. 1 carta strutturale della sicilia (modificata da catalano & d’argenio, 1982; catalano et al., 1996): 1. unità dell’avampaese ibleo; 2. unità di piattaforma carbonatico-pelagica (trapanese-saccense); 3. unità di monte genuardo (transizione piattaforma-bacino); 4. unità di mare profondo (sicano); 5. unità di piattaforma carbonatica (panormide); 6. unità di scarpata-bacino (imerese-prepanormide); 7. unità dei flysch miocenici (numidico e flysch interni); 8. unità sicilidi; 9. unità cristalline calabro-peloritane; 10. depositi sinorogeni mio-pliocenici; 11) depositi sintettonici plio-pleistocenici;12. vulcaniti plio-quaternarie; 13. depositi pleistocenici; 14. quadro di unione dei fogli geologici carg in scala 1:50.000. la carta raffigurata in b) illustra i differenti settori crostali della regione centrale del mediterraneo (modificata da catalano et al., 2002): 1. crosta oceanica del mar tirreno; 2. crosta oceanica del bacino algerino; 3. crosta continentale assottigliata kabilo e sarda; 4. crosta continentale (5. assottigliata) africana; 6. crosta oceanica del mar ionio; 7. unità tettoniche sarde; 8. unità kabilo-calabridi; 9. unità siciliane-maghrebidi; 10. prisma di accrezione ionico; 11. fronti di sovrascorrimento; 12. faglia con probabile componente transtensiva; 13. isobate (in km) della moho; 14. limite ipotetico della crosta oceanica ionica o limite margine passivo-oceano ionico; 15. batimetria. geological map of sicily (after catalano & d’argenio, 1982; catalano et al., 1996): 1. hyblean foreland units 2. trapanese-saccense pelagic-carbonate platform units; 3. monte genuardo unit (platform-basin transition); 4. sicanian basinal units; 5. panormide carbonate platform units; 6. imerese-prepanormide slope-to-basin units; 7. numidian and internal flysch units; 8. sicilidi units; 9. calabropeloritani crystalline units; 10. miocene-pliocene synorogenic deposits; 11. plio-pleistocene syntectonic deposits;12. plio-quaternary volcanism; 13. pleistocene deposits; 14. location map of the 1:50.000 geological map sheets (carg project). b) simplified structural map of the central mediterranean area showing the different crustal sectors of the region (after catalano et al., 2002): 1. tyrrhenian oceanic crust; 2. oceanic crust of the algerian basin; 3. kabylian and sardinian thinned continental crust; 4. african continental crust (5. thinned); 6. ionian oceanic crust; 7. sardinian tectonic units; 8. kabilo-calabridi units; 9. siculo-maghrebian units; 10. ionian accretionary wedge; 11. thrust fronts; 12. probably strike-slip (transtensional) fault; 13. isobath (in km) of the moho; 14. ionian oceanic crust hypothetical boundary or passive margin-ionian ocean boundary; 15. bathymetry. 348 1979; catalano & d’argenio, 1982; bianchi et al., 1989; antonelli et al., 1991); b) un’avanfossa recente, localizzata nell’offshore meridionale della sicilia (bacino di gela) e nella regione iblea lungo il margine settentrionale dell’avampaese dove è in parte sepolta dal fronte della catena (falda di gela); c) una catena complessa, vergente verso sse, spessa a luoghi più di 15 km, costituita (dall’interno verso l’esterno) da un elemento “europeo” (unità peloritane), un elemento “tetideo” (unità sicilidi) ed un elemento “africano” (unità appenninicomaghrebidi). le unità più interne disposte nell’offshore settentrionale dell’isola sono generalmente collassate verso nord in relazione all’apertura del tirreno centro-meridionale (rehault et al., 1987). recenti lavori, supportati da numerosi profili sismici a riflessione (catalano et al., 2000; bello et al., 2000), descrivono la catena siciliana come il risultato della sovrapposizione, da occidente ad oriente, di unità tettoniche pellicolari (risultanti dalla deformazione di terreni meso-cenozoici appartenenti agli originari domini bacinali sicilide, imerese e sicano) su un cuneo di thrust, spesso 6-7 km (derivante dalla deformazione di terreni meso-cenozoici appartenenti ad un originario dominio di piattaforma carbonatica trapanese, saccense o panormide). l’insieme così strutturato poggia, a sua volta, sull’avampaese non deformato che affiora nel plateau ibleo e si continua nel canale di sicilia (ibleopelagiano). nell’area in studio (fig. 1) le strutture più antiche sono oggi di difficile riconoscimento poiché ad esse spesso si sono sovrapposti gli effetti della successiva tettonica trascorrente e trastensiva correlabile all’apertura del tirreno (plio-pleistocene). i corpi piegati e sovrascorsi, di cui spesso si riconoscono solo i relitti delle strutture originarie, sono oggi dislocati e ribassati, generalmente verso il settore costiero settentrionale. vengono riconosciuti due sistemi di faglie con andamento no-se e ne-so. quest’ultimo appare il più importante anche in ragione dei rigetti riconoscibili che raggiungono il migliaio di metri. nel pliocene inferiore le aree più settentrionali hanno subito una subsidenza differenziale che è stata attiva fino a 2.4 milioni di anni fa, con settori che si approfondivano rapidamente. durante questo intervallo il substrato deformato venne scomposto lungo faglie listriche dirette con crescita che hanno determinato l’apertura di half-graben progressivamente riempiti da sedimenti clastici. negli ultimi 500.000 anni l’area risulta tettonicamente ancora attiva, con faglie dirette e trascorrenti che dislocano anche i depositi del tirreniano, o di età più recente (abate et al., 1998), affioranti a quote differenti lungo la fascia costiera. questi movimenti accompagnano un lento ma prolungato sollevamento che interessa la piattaforma continentale, la costa e anche le aree più interne, lungo tutta la sicilia nord-occidentale (mauz et al., 1997; di maggio et al., 1999). i meccanismi focali compressivi e/o transpressivi ricavati dagli eventi tellurici di bassa intensità e profondità, recentemente verificatisi nell’offshore di capo san vito (agate et al., 2000), suggeriscono come l’attività tettonica nell’area sia attualmente segnata dal succedersi di eventi compressivi e/o traspressivi. i caratteri geomorfologici e morfotettonici di vaste aree della sicilia nord-occidentale sono stati descritti da hugonie (1979; 1982), di maggio (1997; 2000), agnesi et al. (2000a), agnesi et al. (2002) e bonfiglio et al. (2004). dati inediti recenti, cui si aggiungono ricerche specifiche condotte nell’ambito del progetto carg, integrano le informazioni contenute in letteratura. l’assetto geomorfologico della sicilia nord occidentale è contrassegnato da una sostanziale congruenza tra tettonica e morfologia, con una significativa coincidenza fra alti e bassi strutturali e topografici. questa coincidenza è da imputare in alcuni casi a processi tettonici, in altri all’erosione selettiva. infatti: a) nei settori costieri occidentali e settentrionali si rinvengono grandi forme tettoniche (horst, graben e halfgraben) dovute a eventi distensivi ripetutisi nel corso del quaternario, con imponenti scarpate di faglia rielaborate dal mare (falesie di faglia o paleofalesie di faglia degradate); b) nelle aree immediatamente più interne si trovano forme strutturali derivate (brachianticlinali o rilievi di anticlinale e brachisinclinali o valli di sinclinale), delimitate da estese scarpate e versanti di linea di faglia. in questo secondo caso e malgrado l’erosione selettiva, la congruenza fra struttura e morfologia si è realizzata grazie alla sovrapposizione di rocce tenere (coperture terrigene cenozoiche) su rocce dure (carbonati mesozoici). questo assetto ha favorito: 1) lo smantellamento delle coperture più erodibili e la conseguente esumazione del più resistente substrato carbonatico nelle situazioni di alto strutturale, dove il rallentamento dell’erosione ha determinato situazioni di alto topografico (principali rilievi montuosi); 2) il continuo e progressivo approfondimento delle originarie aree di basso strutturale, nelle quali gli spessori delle coperture erano maggiori, con la conseguente formazione di accentuati bassi topografici (principali depressioni vallive). rare sono le situazioni di inversione del rilievo, localizzate nelle aree in cui si è avuta la venuta a giorno di rocce tenere al di sotto di rocce dure. molto diffuse le forme relitte dovute, o conseguenti, a: erosione laterale/spianamento (differenti cicli, ripetuti dalle aree sommitali verso le quote più basse, di superfici di spianamento, glacis di erosione in rocce tenere, piattaforme di abrasione marina e superfici di erosione fluviale); processi di approfondimento (gole fluviali, valli a “v”, valli sospese ed abbandonate); aumento delle energie del rilievo (diverse forme prodotte da erosione selettiva o da deformazioni gravitative profonde di versante). le modificazioni geomorfologiche del rilievo sono indotte da una tendenza all’abbassamento del livello di base dell’erosione (agnesi et al., 2000a; di maggio, 2000; agnesi et al., 2002). questa tendenza sembra essere determinata dal la fase di uplift regionale del quaternario. alla fase di sollevamento si sono sovrimposte oscillazioni ad alta frequenza (1-2.10 2 ky) indotte dalle fluttuazioni glacioeustatiche (catalano et al., 1998), con l’alternarsi di stazionamenti del livello di base ad alte (durante eventi climatici caldi) e a basse quote (durante eventi climatici freddi). la fase di uplift, unitamente alla riduzione areale del settore settentrionale della catena emersa prodotta dalla tettonica distensiva, è quindi responsabile del ripetersi dei processi morfogenetici verso quote via via più basse. c. di maggio et al. 349 3. metodi e tecniche analitiche i depositi quaternari sono stati cartografati alla scala di 1:10.000, con particolare cura anche per gli affioramenti di modesta estensione, separando i differenti litotipi affioranti (fig. 2). sono state ricostruite numerose (più di un centinaio) e dettagliate colonne stratigrafiche che hanno mostrato i rapporti geometrici esistenti fra i litotipi. osservazioni paleontologiche, granulometriche, tessiturali e composizionali dei depositi, hanno consentito il riconoscimento delle strutture sedimentarie principali e le associazioni fossilifere più indicative. studi geomorfologici, condotti tramite indagini dirette e osservazioni fotogeologiche, hanno contribuito sia al riconoscimento delle facies sedimentarie dei depositi (attraverso l’individuazione di forme di accumulo e dei relativi sedimenti), sia all’interpretazione del contesto geomorfologico e morfotettonico in cui le successioni di terreni si sono conservate. di conseguenza le ricerche hanno privilegiato: aree interessate da “rapida” sedimentazione marina o costiera (graben e halfgraben presenti lungo le fasce costiere, sommersi durante i l pleistocene inferiore e, a partire dal pleistocene medio, gradualmente emersi); superfici di terrazzi marini o fluviali; zone al piede di scarpate o di versanti rocciosi fortemente acclivi; versanti argillosi a media o bassa inclinazione; aree di fondovalle; spiagge e aree costiere; depressioni o cavità carsiche; grotte carsiche o marine. particolare cura è stata rivolta allo studio delle superfici di discontinuità. la loro interpretazione è stata possibile grazie ad analisi stratigrafiche (riconoscimento di discordanze angolari, paraconcordanze, lacune), stratigrafico-geomorfologiche (riconoscimento di superfici di erosione/deposizione attraverso la ricostruzione dei processi morfogenetici responsabili della loro genesi) e pedogenetiche (riconoscimento di paleosuoli). per la ricostruzione delle successioni di terreni e la datazione e correlazione di depositi e/o superfici (fig, 3) sono stati utilizzati: 1) metodi geometrici basati sui principi di sovrapposizione (depositi più recenti ricoprono superfici e depositi più antichi), intersezione (superfici di discontinuità tagliano depositi e/o superfici più antichi e risultano sigillate o tagliate, rispettivamente, da depositi o superfici più recenti) e di continuità (prosecuzione fisica, più o meno ininterrotta, di affioramenti e, soprattutto, di superfici di discontinuità), che hanno consentito la ricostruzione di elementi ante e post quem; 2) contenuto fossilifero, che ha permesso il riconoscimento di depositi e superfici “guida” (vincoli cronologici); 3) datazioni di depositi condotte in passato da altri autori con metodi di termoluminescenza (mauz et al., 1997) o di aminostratigrafia (hearty et al., 1986; bada et al., 1991), le cui informazioni sono state ricavate da consultazione bibliografica; 4) affinità fra depositi anche molto distanti, ma con analoghe caratteristiche e uguali relazioni geometriche con altri corpi rocciosi e/o superfici; 5) analisi altimetriche basate sulle quote assolute (per superfici di terrazzi marini e relativi depositi) o sulle differenze di quota rispetto ai fondovalle (per superfici di terrazzi fluviali e relativi depositi), tenendo naturalmente conto delle possibili deformazioni tettoniche; 6) analisi paleoclimatiche e paleoambientali, che hanno vincolato la collocazione di alcuni corpi rocciosi a ben definiti eventi climatici, caldi o freddi, del quaternario. 4. litofacies dei depositi quaternari nell’area studiata sono stati riconosciuti numerosi corpi rocciosi quaternari (fig. 2) caratterizzati da specifiche facies. depositi marini: arenarie calcaree o quarzose a stratificazione piano-parallela, con livelli ruditici, contenenti coralli, briozoi, alghe e molluschi (fra questi ultimi alcuni ospiti nordici), passanti localmente a biolititi a fig. 2 carta dei sintemi quaternari della sicilia nord-occidentale: 1. sintema di capo plaia; 2. sintema di raffo rosso; 3. sintema di barcarello; 4. sintema di polisano; 5 sintema della piana di partinico; 6. sintema dell’imera settentrionale; 7. sintema di marsala; 8. principali scarpate/versanti di faglia e falesie/paleofalesie di faglia. quaternary synthem map of nw sicily: 1. capo plaia synthem; 2. raffo rosso synthem; 3. barcarello synthem; 4. polisano synthem; 5 piana di partinico synthem; 6. imera settentrionale synthem; 7. marsala synthem; 8. main fault scarps or slopes and fault cliffs or abandoned cliffs. unità a limiti inconformi utilizzate per la cartografia dei depositi ... 350 coralli, di ambiente di piattaforma o di scogliera; argille a foraminiferi planctonici e con molluschi ospiti nordici, di ambiente neritico-batiale. questi depositi si r invengono lungo le aree costiere pianeggianti impostate su depressioni tettoniche. depositi di transizione: ghiaie attuali o conglomerati relitti, talvolta bioclastici, generalmente poligenici ed eterometrici, a ciottoli prevalentemente appiattiti, con contenuto fossilifero prevalentemente costituito da ospiti senegalesi, di ambiente intertidale; arenarie calcaree o quarzose a stratificazione e laminazione piano-parallela, inclinata o incrociata, con livelli bioturbati, a luoghi ricche di gusci di molluschi, di ambiente di spiaggia sommersa; sabbie attuali o arenarie relitte a stratificazione o laminazione pianoparallela, di ambiente di spiaggia intertidale ed emersa; arenarie e conglomerati a stratificazione e laminazione piano-parallela o inclinata, di ambiente di delta sommerso; sabbie attuali e arenarie calcaree o quarzose, a stratificazione e laminazione incrociata, in facies di duna di retrospiaggia; blocchi decimetrici (diametro massimo 1 m), da sciolti (attuali) a cementati, organizzati in cordoni paralleli alle attuali o antiche linee di costa, in posizione comunque arretrata e a pochi metri di distanza dalle ripe marine, prodotti dalle mareggiate più intense (depositi di tempesta). i depositi di transizione si ritrovano su antiche superfici di abrasione marina, all’interno di grotte marine, lungo fasce costiere attuali o relitte o alternati ai precedenti depositi marini, testimoniando così antiche oscillazioni del livello marino. depositi fluviali: ghiaie e conglomerati poligenici a ciottoli prevalentemente arrotondati, talvolta con strutture embricate; sabbie e arenarie generalmente monogeniche, con livelli a laminazione incrociata o pianoparallela; rari e sottili livelli pelitici con blanda stratificazione piano-parallela. questi depositi sono solitamente organizzati in livelli ben classati a struttura lenticolare. sono presenti nei principali fondovalle, costituendo le attuali pianure e conoidi alluvionali, e sospesi lungo i versanti vallivi, ove ricoprono superfici di erosione fluviale abbandonate. depositi eolici: sabbie e arenarie di natura quarzosa o carbonatica, a stratificazione e laminazione incrociata, contenenti raramente gusci di polmonati. al loro interno, ma solo nel caso di depositi di duna di ostacolo, si alternano a livelli ruditici a ciottoletti, ciottoli e più rari blocchi rocciosi spigolosi (accumuli di crollo o detriti di falda) derivanti dalla degradazione dei sovrastanti versanti. si rinvengono al piede dei principali versanti montuosi che si affacciano lungo le aree costiere pianeggianti della sicilia nord-occidentale, costituendo così delle dune di ostacolo, o lungo le stesse aree pianeggianti, con caratteri di duna costiera. i depositi di duna di ostacolo, essendo generalmente sepolti da detriti e colluvi più recenti, sono stati spesso riconosciuti grazie a tagli artificiali; i depositi di duna costiera sono più facilmente riconoscibili in quanto preservano l’originaria forma. depositi colluviali: suoli pelitici o sabbiosi rimaneggiati, variamente cementati, contenenti, a luoghi, gusci di gasteropodi terrestri o resti di vertebrati; livelli detritici a clasti da arenitici a ruditici (essenzialmente ciottoli), questi ultimi da angolosi a sub-arrotondati e per lo più fangosostenuti in matrice terrosa o sabbiosa; allineamenti di ciottoli alterati immersi in matrice pelitica (“stone line”, sensu ruhe, 1959; retallack, 1990). affiorano diffusamente in tutta l’area studiata. gli accumuli più consistenti si trovano lungo i versanti in argilla, al piede delle scarpate o dei pendii rocciosi fortemente acclivi (intercalati a depositi di falda detritica) e all’interno di depressioni, cavità e grotte carsiche o marine. generalmente si originano lungo superfici inclinate, dove si hanno materiali sciolti (depositi) o rocce tenere (argille alterate e suoli) che possono facilmente essere presi in carico dalle acque dilavanti, sebbene il loro trasporto e la loro successiva sedimentazione possa per qualche chilometro inoltrarsi, nel caso di inondazioni a coltre o di trasporto in massa, fino alle confinanti zone pianeggianti. fig. 3 rapporti geometrici fra depositi quaternari e/o superfici di discontinuità lungo il versante occidentale di montagna raffo rosso. el suoli attuali. sintema di capo plaia: cpc accumuli di crollo; cpcl detriti di falda e depositi colluviali. sintema di raffo rosso: rrdp detriti stratificati e cementati con intercalazioni di paleosuoli; rrdr detriti stratificati e cementati fortemente rimaneggiati; rrds detriti stratificati e cementati; rrc accumuli di crollo. sintema di barcarello: bc depositi colluviali cementati. sintema di polisano: psc accumuli di crollo; pse depositi eolici. sintema della piana di partinico: pp depositi costieri. sb substrato mesozoico. geometric relationships between quaternary deposits and/or unconformity surfaces along the western slope of montagna raffo rosso. el recent soils. capo plaia synthem: cpc fall accumulations; cpcl breccias talus and colluvial deposits. raffo rosso synthem: rrdp stratified slope deposits with palaeosols; rrdr reworked stratified slope deposits; rrds stratified slope deposits; rrc fall accumulations. barcarello synthem: bc welded colluvial deposits. polisano synthem: psc fall accumulations; pse aeolian deposits. piana di partinico synthem: pp coastal deposits. sb mesozoic substrate. c. di maggio et al. depositi di falda: frammenti rocciosi spigolosi o angolosi, di differente granulometria, sciolti o debolmente cementati, derivanti dalla degradazione dei versanti e accumulatisi alla base dei pendii per processi di caduta di detrito e, occasionalmente, di crollo. seppelliti da materiali più recenti e affioranti solo lungo tagli naturali o artificiali, si hanno anche spessi pacchi di detriti stratificati e cementati (éboulis ordonné), organizzati in livelli solitamente ben classati, tipici di un clima più freddo ed arido dell’attuale. si alloggiano al piede delle scarpate e dei versanti rocciosi subverticali, laddove le condizioni topografiche o l’assenza di agenti erosivi ha consentito la formazione di una falda detritica. depositi di frana: materiali variegati per dimensione e composizione, a giacitura caotica (accumuli di crollo/ribaltamento, colamento e scorrimento traslativo di blocchi) o in qualche modo “ordinata” (accumuli di scorrimento rotazionale o di scorrimento traslativo di roccia in blocco). si raccolgono al piede di scarpate e pendii molto acclivi (macereti di crollo/ribaltamento o, in minor misura, di scorrimento traslativo) o lungo i versanti a componente argillosa (accumuli di scorrimento o di colamento). depositi chimici: locali concrezionamenti, croste calcitiche e depositi di grotta in genere, o di ben più estesi e potenti corpi di travertino. si trovano all’interno di cavità e grotte carsiche o marine e in corrispondenza di attuali o antichi punti di risorgenza, cascata o di turbolenza fluviale. 5. unità stratigrafiche a limiti inconformi i depositi appena descritti si rinvengono isolati e in lembi relitti, oppure costituiscono affioramenti più estesi con spessori significativi di differenti litotipi, con variazioni laterali e verticali di facies. i corpi sedimentari sono limitati da superfici di discontinuità e, per i depositi più recenti, il limite superiore è la superficie topografica attuale. le discontinuità in esame, marcate a volte dalla presenza di paleosuoli, corrispondono tanto a superfici di non deposizione, quanto a superfici di erosione subacquea o subarea. le superfici di erosione individuate costituiscono il risultato di processi di tipo via via marino-costiero, idrico (dovuti alle acque correnti superficiali, incanalate o diffuse), gravitativo o carsico. assumono l’aspetto di: piattaforme di abrasione marina; falesie o ripe di erosione costiera, con relativi solchi e grotte marine; superfici di erosione fluviale; scarpate o ripe fluviali; alvei fluviali; rivoli e solchi di ruscellamento; superfici dilavate prodotte da erosione areale o inondazione a coltre; superfici di distacco di frana; canali di frana o di trasporto in massa; piani di soluzione chimica (superfici di cavità o di depressioni carsiche in genere). alcune di queste superfici sono geneticamente legate a cambiamenti ambientali a vasta scala collegati a variazioni climatiche o ad eventi tettonici, con bruschi passaggi da fasi di sedimentazione (o di erosione) a fasi di erosione (o di sedimentazione): in questo caso esse assumono una importanza regionale. altre sono invece riconducibili a modificazioni ambientali locali, rivestendo un certo interesse solo per aree di limitata estensione. a luoghi la discontinuità-limite fra due o più corpi rocciosi può anche essere verticale e, nel caso di accumuli isolati e discontinui, i depositi più recenti possono ritrovarsi a quote inferiori rispetto a depositi più antichi. l’analisi sedimentaria dei depositi studiati, la geometria dei rapporti fra di loro esistenti e la giacitura delle discontinuità a scala regionale ha consentito di separare vari sintemi, più avanti illustrati. corpi rocciosi e superfici di inconformità sono stati datati e, quando possibile, correlati (fig. 4) con le curve delle variazioni degli stadi isotopici del 18o ‰ (ois, oxygen isotope stage) di shackleton (1995). 5.1 sintema di marsala l’unità sedimentaria consiste di alternanze localmente cicliche di: a) sottili livelli di conglomerati, arenarie e sabbie, con bioclasti (ambiente intertidale o di spiaggia emersa); b) arenarie e conglomerati a stratificazione e laminazione inclinata (fig. 5) o piano-parallela (ambiente di delta sommerso); c) calciruditi e biolititi a coralli (ambiente di scogliera); d) arenarie e sabbie bioclastiche o litoclastiche prevalentemente carbonatiche e in subordine quarzose, a stratificazione e laminazione piano-parallela o incrociata, con livelli bioturbati (ambiente di spiaggia sommersa o infra-circalitorale); e) argille, argille marnose e argille siltoso-sabbiose (ambiente infra-circalitorale). la successione risulta a volte interrotta da locali superfici di abrasione marina ubicate a diverse altezze stratigrafiche. lo spessore varia da 1-2 m fino a più di 90 m. nella piana di palermo questi depositi raggiungono spessori sino a circa 95 m (calvi et al., 2000; contino et al., 2006). i livelli carbonato-clastici sono caratterizzati dalla presenza di coralli, briozoi, spugne, alghe, vermetidi, scafopodi, echinodermi, foraminiferi bentonici, gasteropodi (patella spp.), lamellibranchi (glycimeris spp., pecten jacobaeus, chlamys multistriata, chlamys septemradiata, arctica islandica, ostrea spp.) e molluschi. i depositi argillo-siltoso-marnosi contengono foraminiferi planctonici (globorotalia truncatulinoides excelsa) o bentonici (hyalinea baltica) e ostracodi (di stefano & rio, 1981). diffuso in tutta la sicilia nord-occidentale, affiora in depressioni costiere pianeggianti aperte verso il mare e delimitate verso l’interno da grandi paleofalesie di faglia; queste depressioni coincidono con bassi tettonici. il limite inferiore, laddove è direttamente osservabile sul terreno, è una superficie di abrasione marina intagliata su terreni pre-quaternari e debolmente inclinata verso mare (mediamente 1°-3°), a luoghi interrotta da paleofalesie o scarpate di faglia alte 1-5 m. questa superficie è cartografabile lungo le zone periferiche delle piane, dove affiora tra le quote di 150-200 m (aree più interne) e di 1-2 m s.l.m. (zone costiere marginali). nelle zone costiere centrali il limite inferiore, non direttamente visibile, è stato intercettato, attraverso numerose perforazioni di pozzi, fino ad alcune decine di metri di profondità al di sotto dell’attuale livello marino. l’età dei depositi viene comunemente attribuita al pleistocene inferiore (ruggieri, 1967; 1978; ruggieri et al., 1975b; mauz & renda, 1991) e, precisamente, alle unità informali emiliano p.p. e siciliano (sensu ruggieri et al., 1984) corrispondenti alla parte media e alta del calabriano (nell’accezione di cita et al., 2006; cita et al., 2008); l’età del limite inferiore dovrebbe di conseguenza collocarsi nel calabriano, parte media. 351unità a limiti inconformi utilizzate per la cartografia dei depositi ... la località-tipo proposta è l’area di marsala (estremità occidentale della sicilia) dove si ha una continua ed estesa successione, potente almeno 80 m, di calcareniti litoclastiche e bioclastiche e di argille e argille sabbiose fossilifere, queste ultime presenti nel sottosuolo o intercettate in profondità da alcuni pozzi. depositi colluviali, costituiti da prodotti eluviali e detriti rimaneggiati, contenenti resti di vertebrati appartenenti al complesso faunistico di monte pellegrino (bonfiglio et al., 2002, con bibliografia) del pleistocene inferiore (burgio & fiore, 1997; masini et al., 2008, con bibliografia), sono stati rinvenuti all’interno di cavità carsiche esclusivamente nell’area di monte pellegrino (palermo). essi poggiano su una superficie di dissoluzione carsica che intacca dei calcari mesozoici. considerando la loro età (da 1,6 a 0,9 ma), questi depositi potrebbero appartenere al sintema di marsala, sebbene l’intervallo di tempo ricoperto (santerniano – siciliano, sensu ruggieri et al., 1984), non escluda una loro collocazione più indietro nel tempo rispetto all’età del sintema in oggetto. 5.1.1 considerazioni la deposizione del sintema di marsala è probabilmente da collegare ad un evento tettonico distensivo del pleistocene inferiore che, nelle aree settentrionali della sicilia, avrebbe dato luogo ad una gradinata di faglie, con rigetti di centinaia di metri e il collasso di grandi blocchi al di sotto del livello del mare. in corrispondenza dei blocchi meno ribassati si sarebbero create delle condizioni di mare poco profondo che 352 fig. 4 schema di correlazione cronologico. chronological correlation scheme. fig. 5 piana di castelluzzo. sintema di marsala: calcareniti a laminazione inclinata. piana di castelluzzo. marsala synthem: calcarenites with inclined lamination. c. di maggio et al. avrebbero consentito il modellamento dei fondali ad opera del moto ondoso, con la formazione di piattaforme di abrasione marina progressivamente interessate dalla sedimentazione di depositi costiero-marini. piattaforme di abrasione si sarebbero sviluppate anche ai piedi delle falesie (scarpate di faglia rielaborate dal mare) a causa del loro arretramento parallelo. nei blocchi più dislocati dalla tettonica, con condizioni di mare più profondo e maggiore spazio di accomodamento, si sarebbero rapidamente accumulati notevoli spessori di depositi di piattaforma interna; questi ultimi ricoprirono direttamente una superficie di erosione posta al tetto dei blocchi sprofondati (superficie di erosione subaerea “annegata”?), come è visibile nei profili sismici a riflessione dell’offshore siciliano (agate et al., 1993). il rinvenimento del limite inferiore dislocato a profondità differenti potrebbe comunque essere indicativo di: a) blocchi sprofondati a quote differenti, successivamente colmati dalla sedimentazione marina; b) blocchi dislocati anche successivamente all’inizio della sedimentazione. la prima ipotesi comporta l’esistenza di una fase tettonica più antica dell’inizio della sedimentazione; la seconda ipotesi prevede una prima importante fase tettonica, una fase di sedimentazione e, contemporaneamente o successivamente, una nuova ripresa dell’attività tettonica, con rigetti stavolta dell’ordine di pochi metri (cfr. mauz & renda, 1991). l’alternanza ciclica di depositi paralici e di mare più profondo e la presenza, al loro interno, di superfici di erosione marina di rango inferiore (piattaforme e palofalesie), dovrebbe invece essere collegata alle oscillazioni del livello marino prodotte da fluttuazioni climatiche. i depositi continentali a vertebrati rinvenuti a monte pellegrino intrappolati all’interno di cavità, potrebbero indicare invece la prosecuzione di una lunga fase di continentalità, dominata da processi carsici, pedogenetici e di scorrimento idrico diffuso, relativamente ai settori collinari e montuosi prospicienti le depressioni costiere. 5.2 sintema della piana di partinico i corpi sedimentari del sintema sono costituiti da alternanze di arenarie bioclastiche e biolititi algali (ambiente di piattaforma interna), conglomerati e sabbie con impronte di fondo, depositi di tempesta a laminazione incrociata ed hummocky (ambiente di spiaggia), suoli e brecce rimaneggiati (formati da livelli terrosi e livelli detritici con clasti immersi in abbondante matrice) e concrezioni carbonatiche (ambiente continentale). il contenuto fossilifero è dato da faune marine tipiche di fasi calde del pleistocene (vari ospiti senegalesi) e da associazioni di vertebrati del complesso faunistico siciliano ad elephas falconeri (sensu burgio & cani, 1988; bonfiglio et al., 2002 con bibliografia). i depositi del sintema affiorano nelle depressioni costiere pianeggianti e, in modo discontinuo, lungo l’intera fascia costiera della sicilia nord-occidentale, poggiati su piattaforme di abrasione disposte a varie quote e appartenenti a più ordini di terrazzi marini (fig. 6) o alloggiati all’interno di cavità carsiche o marine. il limite inferiore è una superficie di abrasione marina intagliata su depositi del sintema di marsala o su terreni più antichi e rinvenuta fra circa 150 e 250 m s.l.m. a quota inferiore, da 150-200 m fino a circa 7-26 m s.l.m., tale superficie risulta tagliata da più recenti ripiani di erosione marina (piattaforme di abrasione e paleofalesie) considerati superfici di inconformità di rango inferiore; questi ripiani vanno a costituire una gradinata di terrazzi, prodotta dalle oscillazioni relative del livello marino, su cui si preservano depositi di spiaggia e di piattaforma interna via via più recenti. sulla base del contenuto paleontologico, delle evidenze, stratigrafiche e geomorfologiche e dei risultati ottenuti da datazioni isotopiche, l’età risulta pleistocene medio (mauz et al., 1997; di maggio et al., 1999). località-tipo proposta è l’area tra alcamo e partinico (piana di partinico) dove affiorano limite inferiore e depositi di terrazzo marino disposti a differenti quote e riferibili a più fasi di stazionamento alto del mare nel pleistocene medio. anche nella piana di buonfornello e nei rilievi collinari adiacenti si rinviene una successione ben conservata di depositi essenzialmente costieri, disposti su una gradinata di terrazzi marini, che si sviluppa da 30 fino a circa 250 m s.l.m. sulla base del riconoscimento di una superficie di discontinuità di estensione regionale, correlabile con l’evento climatico caldo immediatamente precedente il tirreniano (ois 7), è stato possibile distinguere due subsintemi. 5.2.1 subsintema di piana di sopra è rappresentato da successioni di depositi continentali, paralici o marini, con geometrie generalmente tabulari, costituite da alternanze di: a) conglomerati poligenici ed eterometrici a supporto granulare, con ciottoli talvolta perforati da spugne clionidi; b) arenarie 353 fig. 6 piana di sopra. sintema della piana di partinico: ppcl suoli e detriti rimaneggiati contenenti resti di vertebrati del complesso faunistico ad elephas falconeri; ppm conglomerati di spiaggia. sm superficie di abrasione marina posta a circa 45 m s.l.m. sb substrato mesozoico. piana di sopra. piana di partinico synthem: ppcl reworked soils and breccias including fossil vertebrates belonging to the elephas falconeri sicilian faunal complex; ppm coastal conglomerates. sm wave-cut surfaces located at about 45 m a.s.l. sb mesozoic substrate. unità a limiti inconformi utilizzate per la cartografia dei depositi ... e sabbie bioclastiche o litoclastiche, a laminazione piano-parallela o, più raramente, incrociata; c) sottili e rari livelli di biolititi algali; d) depositi colluviali variamente cementati, costituiti da suoli terrosi rimaneggiati, con inclusioni di rari clasti da millimetrici a decimetrici, o da livelli detritici di tipo breccia, con frammenti rocciosi talvolta allineati (stone line) immersi in matrice terrosa e/o sabbiosa. i depositi in esame sono localmente deformati da faglie oblique (mauz et al., 1997; di maggio et al., 1999; contino, 2002) il contenuto fossilifero dei depositi marini e di spiaggia è rappresentato da numerosi ospiti senegalesi come spugne, alghe, coralli (cladocora caespitosa), frammenti scheletrici di pesci, lamellibranchi (pettinidi, spondylus spp., glycimeris spp., ostrea spp.), gasteropodi (patella caerulea) e molluschi; quello dei depositi continentali è prevalentemente costituito da gusci di gasteropodi terrestri e da resti di mammiferi appartenenti al complesso faunistico ad elephas falconeri del pleistocene medio (parte inferiore). il limite inferiore del subsintema è costituito dalla piattaforma di abrasione del terrazzo marino più antico conservatosi; questa superficie si rinviene lungo la fascia costiera della sicilia nord-occidentale fra circa 150-250 m s.l.m. nella piana di partinico, in corrispondenza del centro abitato di alcamo a circa 250 m s.l.m., la stessa superficie appare seppellita da un pacco di sabbie e arenarie fossilifere di spiaggia sulle quali poggia un “bancone” di travertino; le datazioni radiometriche delle concrezioni calcaree superiori, ottenute con metodo aminostratigrafico, hanno restituito un’età di circa 455 +/90 ka (bada et al., 1991). all’interno del subsintema sono riconoscibili diverse superfici di inconformità di rango inferiore, costituite da superfici di erosione marina (piattaforme e paleofalesie) appartenenti a più ordini di terrazzi marini, situate a quote inferiori (fino a circa 16-50 m s.l.m.). le alternanze di depositi di spiaggia e continentali descritte sono state riconosciute anche all’interno di numerosi ripari e grotte marini o di solchi di battente, posizionati fra circa 30 e poco più di 100 m s.l.m., a quote correlabili con quelle dei diversi ordini di terrazzi marini in esame. depositi francamente continentali, solitamente detriti o colluvi terrosi di riempimento di grotte, cavità e depressioni di origine carsica, affiorano nelle aree più interne, anche in quelle più lontane dalle zone costiere. banchi di travertino, attribuiti da hugonie (1979) al pleistocene medio, affiorano in vicinanza di zone di risorgenza o lungo aree caratterizzate da flussi idrici laminari. gli spessori di queste successioni continentali sono mediamente di 1-2 m, raramente superano i 5 m; solo nel caso dei depositi di travertino si raggiungono potenze di una decina di metri. considerando le quote relativamente elevate alle quali si rinvengono, i depositi marini o di spiaggia che si trovano sulle superfici di abrasione dei terrazzi marini e all’interno di grotte, ripari e solchi marini, dovrebbero essere correlati a fasi di stazionamento alto del livello del mare. sulla base sia di analisi stratigrafiche, geomorfologiche e paleontologiche condotte da di maggio et al. (1999) nell’area di piana di sopra (penisola di capo san vito, monti di trapani), sia di numerose datazioni effettuate con il metodo della termoluminescenza da mauz et al. (1997) su depositi di terrazzo marino distribuiti fra 18 e 40 m s.l.m. nella piana di partinico, sono state proposte età correlabili agli ois 9, 11 e 1317 (pleistocene medio). sulla base del contenuto faunistico e di datazioni isotopiche (bada et al.,1991; rhodes 1996), i depositi continentali possono invece essere genericamente attribuiti al pleistocene medio (ois che vanno dal 17-19 fino all’8). l’analisi stratigrafica dei dati descritti consente di assegnare all’inizio del pleistocene medio l’età del limite inferiore del subsintema di piana di sopra; quest’ultimo rappresenta anche la superficie basale del sintema di partinico. la località-tipo proposta è l’area di piana di sopra (estremità nord-occidentale della penisola di capo san vito) dove, lungo alcune paleofalesie delimitanti una piattaforma di abrasione marina sommitale, sono intagliati numerosi solchi e grotte contenenti successioni di terreni marini e continentali; cavità e depositi sono distribuiti fra circa 20 e 80 m s.l.m. e sono riferibili a più cicli di stazionamento alto del mare nel pleistocene medio. 5.2.2.subsintema di tommaso natale i corpi sedimentari sono costituiti da: a) conglomerati poligenici di spiaggia; b) brecce cementate, con scheletro granosostenuto costituito da blocchi decimetrici da angolosi a sub-arrotondati, con scarsa matrice ruditica fine e arenitica, a giacitura caotica, prodotti da intense mareggiate (depositi di tempesta); c) calcareniti e sabbie calcaree o, in subordine, quarzose, con livelli bioclastici, a stratificazione piano-parallela e laminazione piano parallela o incrociata. lo spessore medio è di circa 1-2 m. questi depositi appaiono talvolta dislocati da faglie con rigetti verticali di pochi metri e componente di movimento orizzontale (cfr. di maggio et al., 1999; agnesi et al., 2000a; di maggio, 2000). il contenuto fossilifero è costituito da ospiti senegalesi quali brachiopodi (megathiris detruncata), cirripedi, echinodermi (arbacia lixula), coralli (astroides calycularis), lamellibranchi (corbula revoluta, chlamys multistriata, ostrea edulis, pecten jacobaeus), gasteropodi (cymatium ficoides, cantharus viverratus) e molluschi in genere. il limite inferiore è una piattaforma di abrasione marina che può svilupparsi, a seconda dei diversi settori costituenti la fascia costiera della sicilia nord-occidentale, fra 8-26 m s.l.m. (quota minima) e 15-50 m s.l.m. (quota massima); essa è incisa a spese dei depositi del subsintema di piana di sopra (o di terreni più antichi) ed è talvolta contrassegnata da paleosuoli. sulla base del contenuto fossilifero e di datazioni radiometriche effettuate su resti fossili o frammenti quarzosi da hearty et al. (1986) nei pressi dell’abitato di tommaso natale e da mauz et al. (1997) nella piana di partinico, l’età di questi depositi (e della sottostante piattaforma di abrasione marina che costituisce il limite inferiore del subsintema) è correlabile con quella dell’ultima fase di stazionamento alto del livello marino del pleistocene medio (ois 7). la località-tipo proposta è l’area di tommaso natale (monti di palermo) dove, su una piattaforma di abrasione marina localizzata a circa 45-50 m s.l.m., si hanno i depositi costieri datati da hearty et al. (1986). 5.2.3. considerazioni la formazione del sintema di partinico sembra essere collegata all’interazione tra oscillazioni del livello 354 c. di maggio et al. del mare (dovute a variazioni climatiche) e graduale e generalizzata tendenza al sollevamento della sicilia nord-occidentale. la combinazione di questi due fattori ha determinato, lungo le aree costiere, la formazione di superfici di abrasione marina e di falesie che, al succedersi di ogni fase di stazionamento alto del mare, si sono ciclicamente ripetute a quote via via inferiori a causa del progressivo innalzamento tettonico della regione in esame; si è così prodotta una gradinata di più ordini di terrazzi marini emersi, con superfici ricoperte da sedimenti. il ritrovamento a quote differenti, lungo le varie aree di affioramento, della superficie e del margine interno di uno stesso ordine di terrazzo marino (antonioli et al., 1999; di maggio et al., 1999; di maggio, 2000) consente di ipotizzare l’esistenza sia di settori che si sono sollevati con tassi di velocità diversi, sia di blocchi tettonici variamente dislocati. i tassi medi di sollevamento riferibili al pleistocene medio sono generalmente valutati tra 0,11 e 0,14 m/ka (mauz et al., 1997; antonioli et al., 1998; di maggio et al., 1999). il rinvenimento di depositi colluviali pedogenizzati all’interno di cavità carsiche nei settori più interni dell’area studiata, è invece indicativo del proseguimento della fase di continentalità di queste regioni. 5.3 sintema di polisano la successione dell’unità è costituita da arenarie e sabbie eoliche di natura prevalentemente quarzosa e in subordine calcarea, variamente cementate, a stratificazione e laminazione incrociata (fig. 7). tali depositi si rinvengono in facies sia di duna di ostacolo, addossati contro pareti montuose, sia di duna costiera, conservando l’originaria forma. nelle dune di ostacolo gli accumuli sabbiosi mostrano, al loro interno, inclusioni di elementi detritici sparsi, di varie dimensioni, derivanti da processi di degradazione, caduta di detrito e crollo dai sovrastanti versanti montuosi; intercalazioni di livelli ben definiti e relativamente più continui, formate da accumuli caotici di grossi massi frammisti a materiale litoide più fine, a giacitura caotica e dello spessore di qualche metro, sono invece riconducibili a locali fenomeni di crollo. lo spessore varia da pochi ad una decina di metri. il contenuto fossilifero è dato da rari gusci di gasteropodi polmonati. affiora in modo discontinuo, con corpi sedimentari isolati, lungo le aree costiere pianeggianti e a ridosso dei principali versanti montuosi rivolti verso mare. il limite inferiore, ubicato a differenti quote, è in parte una superficie di non deposizione al tetto dei depositi del subsintema di tommaso natale e in parte una superficie di erosione subaerea, incisa su terreni più antichi, marcata da chiare discordanze angolari e talvolta da paleosuoli. lo stesso limite è stato riconosciuto nella piana di castelluzzo, in località case polisano (penisola di capo san vito) e nel versante orientale di monte gallo (monti di palermo). in questi siti affiorano depositi eolici del sintema in oggetto che da una parte ricoprono una superficie (limite inferiore) al tetto di accumuli di terrazzo marino del subsintema di tommaso natale e, dall’altra, sono tagliati da superfici di erosione (piattaforme e falesie, coincidenti con il limite superiore) di età “eutirreniana” (sensu bonifay & mars, 1959), correlabile all’età dell’ois 5e, in quanto queste superfici sono ricoperte da depositi a strombus bubonius. anche nella piana di carini, a sferracavallo e montagna raffo rosso (monti di palermo) i depositi del sintema di polisano sono a luoghi incisi da superfici di erosione marina o subaerea dell’ois 5e. sulla base dei rapporti geometrici, l’età di questi depositi è da riferire all’ois 6, mentre il limite inferiore va collocato fra la fine dell’ois 7 e l’inizio dell’ois 6. la località-tipo proposta è l’area di case polisano (piana di castelluzzo) dove affiorano arenarie di duna costiera che, verso mare, sono intagliate da piattaforme e ripe marine dell’ois 5 e che, verso monte, ricoprono un terrazzo marino e i relativi depositi del subsintema di tommaso natale, questi ultimi correlabili all’ois 7. 5.3.1 considerazioni i depositi eolici del sintema vengono considerati tipici di un evento climatico glaciale e probabilmente arido (cfr. hugonie, 1979; 1982; ulzega & hearty, 1986; cremaschi & trombino, 1998; d’orefice et al., 2007); durante questo evento il vento asportava grandi quantità di materiali fini e sciolti dalle piattaforme appena emerse, accumulandole lungo le aree costiere pianeggianti (dune di retrospiaggia) oppure rilasciandole ai piedi dei versanti prospicienti le fasce costiere (dune di ostacolo). gli accumuli eolici del sintema di polisano ricoprono superfici e depositi del subsintema di tommaso natale (correlabili all’ois 7) e sono incisi da una superficie di erosione dell’ois 5e; la posizione stratigrafica induce a riferire questi depositi al penultimo evento climatico glaciale del quaternario, correlabile 355 fig. 7 versante meridionale di monte gallo. sintema di polisano: arenarie eoliche a laminazione e stratificazione incrociata. southern slope of monte gallo. polisano synthem: aeolian arenites with cross-bedded stratification/lamination. unità a limiti inconformi utilizzate per la cartografia dei depositi ... con l’ois 6. il limite inferiore del sintema (superficie di non deposizione e di erosione subaerea) coincide con segmenti sepolti dell’antica superficie topografica precedente l’evento glaciale in esame; assume quindi un significato climatico. gli accumuli detritici intercalati fra i depositi eolici, prodotti da processi sia di degradazione fisica delle rocce sia gravitativi, ne confermerebbero il significato in quanto indicativi di un evento di recrudescenza climatica. 5.4 sintema di barcarello l’unità raggruppa depositi costieri e continentali. tra gli sporadici depositi costieri si riconoscono: a) arenarie e sabbie fossilifere a laminazione piano parallela o incrociata, di spiaggia sommersa; b) conglomerati poligenici ed eterometrici arrossati, con elementi litoclastici e in subordine bioclastici, a scarsa (o del tutto assente) matrice ruditica fine o arenitica e supporto granulare, di ambiente di spiaggia intertidale; c) biolititi a vermetidi, di mare basso; d) brecce cementate con blocchi e ciottoli angolosi, a giacitura caotica, con scarsa e sporadica matrice arenitica (depositi di tempesta). lo spessore massimo raggiunto è di un paio di metri. i depositi continentali, di natura colluviale, sono: a) arenarie terrose e suoli rimaneggiati da ben cementati a scarsamente coesi, talvolta con tasche di riassorbimento, frequenti tracce di bioturbazione e presenza di aggregati argillosi ricchi in ossidi di ferro; b) livelli a clasti o blocchi angolosi e alterati, immersi in una ricca matrice terrosa e pelitica fine con tracce di pedorelitti (di maggio et al., 1999; boschian, 2002) e con concrezioni carbonatiche nodulari, a supporto fangoso, allineati a formare orizzonti debolmente inclinati (stone line); c) brecce detritiche fossilifere, da scarsamente a ben cementate, ricche di clasti litoidi angolosi di dimensioni da centimetriche a decimetriche e incrostati da ossidi di ferro e/o manganese, a struttura fangosa o granulare, con matrice terrosa o sabbiosa; d) peliti rossastre fini (“terre rosse” rimaneggiate) a laminazione piano-parallela, e) arenarie e sabbie eoliche o di spiaggia rimaneggiate, con inclusioni di elementi ruditici da angolosi a sub-arrotondati, con matrice terrosa. questi depositi sono incisi da locali superfici di erosione subaerea, prodotte dal dilavamento. il loro spessore medio è di circa 2-3 m, con valori massimi dell’ordine dei 5 m. le frequenti interdigitazioni fra i depositi costieri e i terreni continentali, riconosciute in alcune aree costiere come a case ferriato (penisola di capo san vito, fig. 8) e nelle località barcarello e la cala (monti di palermo), testimoniano una loro sostanziale contemporaneità di deposizione. deformazioni da locali faglie a componente trascorrente vengono indicate da abate et al. (1998) e nigro et al. (2000). i depositi marino-paralici contengono faune banali ma anche importanti ospiti senegalesi, quali vermetidi, echinidi, alghe, coralli, lamellibranchi (ostrea edulis, hyotissa hyotis, glycimeris glycimeris, spondylus gaederopus) e gasteropodi (patella ferruginea, cerithium lividulum lividulum, cerithium vulgatum, strombus bubonius, mitra fusca, conus mediterraneus, conus testudinarius, cantharus viverratus). i depositi continentali sono caratterizzati da livelli con abbondanti gusci di gasteropodi polmonati e resti di vertebrati appartenenti al complesso faunistico ad elephas mnaidriensis (sensu burgio & cani, 1988; bonfiglio et al., 2002 con bibliografia) datato al tardo pleistocene medio pleistocene superiore. il sintema si estende nella fascia costiera della sicilia nord-occidentale, lungo le fasce pedemontane delle aree collinari e montuose e all’interno di grotte e depressioni carsiche. il suo limite inferiore è una piattaforma di abrasione marina (fig. 9) pressoché ininterrotta, localizzata fra l’attuale livello del mare e le quote comprese fra 7 e 25 m s.l.m.; nelle aree più interne la stessa passa ad una discontinua superficie di erosione subaerea (fig. 10), elaborata da processi di dilavamento. il passaggio fra la piattaforma di abrasione marina e la superficie di erosione subaerea, non osservabile sul terreno, è stato desunto sulla base delle eteropie laterali fra depositi costieri e depositi continentali. il riconoscimento dei rapporti fra superfici di erosione subaeree / depositi a vertebrati e superfici di erosione marina / depositi a strombus bubonius, consente di riferire sia la parte basale dei depositi marino-paralici e dei depositi colluviali ad essi correlati, sia le sottostanti superfici di erosione subacquee e subaeree (limite inferiore), all’ois 5e. il rinvenimento di più recenti conglomerati e arenarie di spiaggia, poggiati su una piattaforma di abrasione marina di rango inferiore situa356 fig. 8 – case ferriato. sintema di barcarello: bcm arenarie di spiaggia; bccl suoli rimaneggiati con livelli di ciottoli allineati (ca). case ferriato. barcarello synthem: bcm coastal arenites; bccl reworked soils with stone lines (ca). c. di maggio et al. ta fra 0 e 3 m s.l.m. e intagliata su depositi e superfici dell’ois 5e, consente di datare la parte alta dei depositi del sintema al “neotirreniano” (sensu bonifay & mars, 1959), ossia al periodo di tempo correlabile con l’ois 5c o 5a (cfr. buccheri, 1966; di maggio et al., 1999; cottignoli et al., 2002). l’unità dovrebbe quindi ricoprire l’intervallo di tempo correlabile con l’intero ois 5. la località-tipo proposta è l’area di barcarello (sferracavallo), dove affiorano depositi di spiaggia, contenenti strombus bubonius, interdigitati con depositi colluviali e poggiati su una piattaforma di abrasione marina intagliata in calcari mesozoici. 5.4.1 considerazioni la formazione del limite inferiore del sintema di barcarello è riconducibile all’ultimo evento climatico caldo del pleistocene (ois 5e) durante il quale: a) lo stazionamento della superficie del mare nel tempo, ad una quota di circa 5-7 m superiore rispetto al livello marino attuale (bloom & yonekura, 1985; radtke, 1989), ha prodotto una piattaforma di abrasione marina (oggi limite inferiore dei depositi costieri); b) una fase morfogenetica dominata da importanti processi di dilavamento, probabilmente favoriti da un periodo relativamente lungo di semiaridità, ha contribuito alla formazione di una superficie di erosione subarea (oggi limite inferiore dei depositi continentali). l’attuale rinvenimento della piattaforma di abrasione da 0 m s.l.m. fino a quote comprese fra 7 e 25 m s.l.m. (margine interno) è indicativo di aree che, a partire dal tempo corrispondente all’ois 5e, si sono sollevate con tassi differenti compresi fra 0 (aree stabili) e 0,2 m/ka (cfr. cosentino & gliozzi, 1988; mauz et al., 1997; antonioli et al., 1999; di maggio et al., 1999; di maggio, 2000). i depositi colluviali, costituiti da suoli rimaneggiati e materiali detritici più o meno grossolani, testimoniano l’alternarsi di condizioni climatiche ora favorevoli alla pedogenesi, ora favorevoli alla degradazione fisica delle rocce e allo sviluppo di sporadici ma intensi eventi di erosione idrica diffusa. la presenza di superfici di erosione di rango inferiore (piattaforma di abrasione marina fra 0 e 3 m s.l.m. e locali superfici di erosione subaerea) è prova di un successivo stazionamento marino a quote inferiori, rispetto a quello dell’ois 5e, e di eventi di ruscellamento particolarmente intensi. questi ultimi sono responsabili anche del trasporto di materiale colluviale fino alle aree costiere allora sommerse. 5.5 sintema dell’imera settentrionale i corpi rocciosi che costituiscono questo sintema appartengono a più ordini di terrazzi fluviali, ubicati all’’interno delle vallate principali e distribuiti da pochi fino ad un centinaio di metri di dislivello rispetto ai fondovalle attuali. i depositi alluvionali hanno geometria tabulare e sono costituiti da prevalenti livelli di ghiaie e/o conglomerati poligenici e di arenarie, sabbie e silt. gli spessori massimi raggiunti, nel caso dei terreni appartenenti agli ordini più recenti, sono di 3 m. nei depositi alluvionali di un terrazzo fluviale sito in vicinanza della foce del fiume imera settentrionale, sospeso ad una decina di metri di altezza sul fondovalle, sono stati rinvenuti resti di hippopotamus pentlandi (battaglia & ciofalo, 1883) appartenenti al complesso 357 fig. 9 – estremità nord-occidentale della penisola di capo san vito. limite inferiore del sintema di barcarello (sm piattaforma di abrasione marina) situato a 2-3 m s.l.m., intagliato su carbonati mesozoici (sb) e ricoperto da conglomerati di spiaggia (bcm); seguono detriti di falda (cpd) e ciottoli di spiaggia (cpm) del sintema di capo plaia. north-western end of penisola di capo san vito. lower boundary of the barcarello synthem (sm – wave-cut platform) located at 2-3 m a.s.l., carved on mesozoic carbonate rock (sb) and covered by coastal conglomerates (bcm); talus breccias (cpd) and coastal pebbles (cpm) of capo plaia synthem follow. fig. 10 – versante occidentale di montagna raffo rosso. limite inferiore del sintema di barcarello (sc – superficie di erosione idrica), inciso su depositi eolici del sintema di polisano (ps) e ricoperto da detriti e suoli rimaneggiati (bc). western slope of montagna raffo rosso. lower boundary of barcarello synthem (sc – water erosion surface) incised on the aeolian deposits of polisano synthem (ps) and covered by reworked breccias and soils (bc). unità a limiti inconformi utilizzate per la cartografia dei depositi ... faunistico ad elephas mnaidriensis (tardo pleistocene medio pleistocene superiore). mauz et al. (1997) effettuano datazioni con il metodo della termoluminescenza su campioni di un conglomerato sterile. tale conglomerato, erroneamente scambiato da questi autori per un deposito di terrazzo marino, è in realtà un deposito di un terrazzo fluviale. esso è infatti localizzato all’interno della valle fluviale del fiume iato, in un tratto in cui il corso d’acqua attraversa, tagliandola, la piana di partinico; risulta sospeso, lungo il versante in destra idrografica, ad una altezza di circa 15 m rispetto al fondovalle. i risultati di questa datazione restituiscono un’età di 227 +/40 ka. depositi alluvionali, ben conservati su piani di erosione laterale appartenenti a vari ordini di terrazzi di erosione in roccia, affiorano “sospesi” rispetto ai fondovalle lungo alcuni settori dei bacini idrografici dei fiumi pollina, imera settentrionale (fig. 11), san leonardo e belice. il limite inferiore del sintema, riferibile al terrazzo fluviale più antico riconosciuto nella sicilia nord-occidentale, è una superficie di erosione laterale, incisa su rocce pre-quaternarie, localizzata lungo la valle del fiume imera settentrionale, a circa 230 m s.l.m. e a un centinaio di metri di altezza rispetto al fondovalle. discordanze di rango inferiore sono presenti ad altezze inferiori dai fondovalle. l’età del limite inferiore del sintema viene qui correlata alla parte inferiore del pleistocene medio sulla base di alcune considerazioni ed osservazioni: 1) le valli fluviali dei corsi d’acqua tirrenici si sono verosimilmente individuate a causa di processi di approfondimento ed erosione regressiva successivi alla tettonica distensiva del pleistocene inferiore; 2) le superfici dei terrazzi e i relativi depositi appaiono preservati solo nelle porzioni medio basali dei versanti vallivi, costituendo forme relativamente recenti; 3) l’apporto dei dati paleontologici e radiometrici. i depositi dei differenti ordini di terrazzi dovrebbero invece ricoprire un intervallo di tempo che va dal pleistocene medio al pleistocene superiore. sulla base di queste considerazioni, il sintema dell’imera settentrionale è correlabile con i sintemi della piana di partinico, di polisano e di barcarello. tuttavia l’assenza di continuità laterale tra questi sintemi, la difficile identificazione all’interno dei depositi del sintema dell’imera settentrionale dei limiti inferiori dei sintemi di polisano e barcarello e la metodologia di rilevamento suggerita dal servizio geologico d’italia (2001) hanno indotto gli autori a definire questa distinta ubsu. la località-tipo proposta si rinviene lungo il tratto di valle del fiume imera settentrionale tra cozzo gracello e monte riparato, dove si riconoscono almeno tre ordini di terrazzi fluvial i, con i relativi depositi, distribuiti da 5-7 m a poco più di 100 m di altezza rispetto all’attuale fondovalle. 5.5.1 considerazioni la genesi dei diversi ordini di superfici di erosione fluviale (limite inferiore e discontinuità di rango minore) è verosimilmente da ricondurre a fasi di stazionamento alto del livello marino (corrispondente al livello di base fluviale) del pleistocene medio; durante queste fasi (coincidenti con eventi climatici caldi) dovevano svilupparsi processi di sovralluvionamento delle valli, successivamente seguite da fasi di erosione laterale/sedimentazione; durante queste ultime si producevano le pianure di erosione laterale su cui attualmente si rinvengono i depositi alluvionali sospesi. in corrispondenza di fasi di stazionamento basso del mare (durante eventi climatici freddi) dovevano invece prevalere processi di erosione di fondo, con l’abbandono dei vecchi depositi a quote superiori. l’alternarsi di queste fasi e la loro interazione con la tendenza generalizzata al sollevamento della sicilia nord-occidentale, ha fatto sì che i processi di erosione abbiano prevalso sui processi di sedimentazione (predominio dell’approfondimento fluviale sul sovralluvionamento delle valli) e che l’attuale assetto stratigrafico sia caratterizzato da terrazzi fluviali (e relativi depositi) più antichi distribuiti a quote più elevate rispetto a terrazzi fluviali (e relativi depositi) più recenti. 5.6 sintema di raffo rosso il corpo sedimentario è formato da potenti pacchi di detrito stratificato e cementato e da depositi eolici, entrambi tipici di un evento climatico freddo e probabilmente arido, e da isolati accumuli di origine colluviale e gravitativa, con livelli pedogenizzati. i detriti stratificati e cementati, di falda detritica (fig. 12), sono organizzati in più livelli ben classati di spessore variabile da 0,5 a 2 m, con scheletro granosostenuto a clasti da molto angolosi a sub-arrotondati del diametro medio di 0,5-20 cm e massimo di 50 cm, con matrice assente o molto scarsa; a luoghi si riconoscono intercalazioni di blocchi e clasti eterometrici a giacitura caotica, interpretabili come accumuli di crollo. i depositi eolici, di ambiente di duna costiera, sono costituiti da sabbie ed arenarie quarzose o calcaree, con tracce di stratificazione e laminazione incrociata. 358 fig. 11 – versante vallivo del fiume imera settentrionale (pressi di monte riparato): cp depositi colluviali (sintema di capo plaia); im conglomerati fluviali (sintema dell’imera settentrionale); sf superficie di erosione fluviale (posta a circa 10 m dal fondovalle); sb substrato clastico miocenico. valley slope of fiume imera settentrionale (near monte riparato): cp colluvial deposits (capo plaia synthem); im fluvial conglomerates (imera settentrionale synthem); sf stream erosion surface (located at about 10 m above valley bottom); sb miocene clastic substrate. c. di maggio et al. i depositi colluviali e gravitativi sono rappresentati da: a) brecce ad elementi ruditici (detriti di falda rimaneggiati); b) sabbie limose, limi argillosi e limi sabbiosi (suoli rimaneggiati) con presenza di concrezioni carbonatiche nodulari e di livelli a blocchi, ciottoli e ciottoletti allineati (stone line); c) limi sabbiosi con abbondanti pedorelitti; d) livelli a blocchi immersi in limi sabbiosi (depositi da debris flow). gli spessori complessivi sono dell’ordine di una decina di metri per i detriti stratificati e cementati, di circa 1-2 m per le eolianiti e di 1-7 m per i depositi colluviali e gravitativi. il contenuto fossilifero, rinvenuto nei depositi colluviali, è costituito da molluschi continentali e da un’associazione di mammiferi riferibili ai complessi faunistici di pianetti e di castello (bonfiglio et al., 2002 con bibliografia) del pleniglaciale – tardiglaciale (75-10 ka). datazioni con la termoluminescenza condotte da mauz et al. (1997) su sabbie quarzose eoliche affioranti nella piana di partinico, hanno restituito età correlabili con gli ois 4-2. i detriti si rinvengono ai piedi di scarpate e versanti rocciosi fortemente inclinati, i depositi eolici lungo le aree costiere pianeggianti e i depositi colluviali in corrispondenza di versanti o all’interno di grotte carsiche o marine e, più genericamente, di depressioni di varia origine. il limite inferiore del sintema è in parte una superficie di non deposizione, coincidente con il tetto dei depositi del sintema di barcarello, ed in parte una preesistente superficie di erosione subaerea, incisa su terreni ancora più antichi e a luoghi marcata da paleosuoli. all’interno delle successioni detritiche e colluviali si rinvengono discontinuità di rango inferiore, anche queste contrassegnate da paleosuoli. l’età dei corpi sedimentari viene riferita all’ultimo evento climatico freddo del quaternario (ois 4-2) sulla base dei rapporti geometrici fra il sintema di raffo rosso e il sintema di barcarello, dell’ambiente di sedimentazione dei depositi in esame e con l’ausilio delle informazioni paleontologiche e radiometriche. la superficie di non deposizione basale (limite inferiore) viene collocata all’inizio dell’evento climatico citato e, più specificamente, alla base dell’ois 4. la località-tipo proposta è il versante occidentale di montagna raffo rosso dove, all’interno di una grande cava, è stata portata alla luce una spessa successione di detriti stratificati e cementati poggiata sui depositi colluviali del sintema di barcarello. 5.6.1 considerazioni la genesi della superficie basale e dei depositi del sintema di raffo rosso è da ricondurre all’innesco di intensi processi di degradazione, favoriti da condizioni climatiche fredde, e di processi eolici, favoriti dall’abbassamento del livello marino e dall’emergere di accumuli sabbiosi prima sommersi; questi processi hanno prodotto, rispettivamente, l’accumulo di notevoli quantità di detriti ai piedi dei versanti e la deposizione di sabbie eoliche lungo le aree costiere, con il conseguente seppellimento di alcuni tratti dell’antica superficie topografica (limite inferiore del sintema) presente all’inizio dell’ultimo evento glaciale. 5.7 sintema di capo plaia il sintema raggruppa: a) depositi alluvionali che poggiano su piani di erosione laterale o che riempiono parzialmente preesistenti valli a “v” (superfici di erosione fluviale), queste ultime prodotte da processi di approfondimento e di erosione regressiva dei corsi d’acqua a seguito dell’abbassamento del livello marino durante l’ultimo evento climatico freddo del quaternario; b) depositi ciottolosi e/o sabbiosi di spiaggia che ricoprono, lungo le coste, superfici di erosione subaerea o di non deposizione, talvolta pedogenizzate, a seguito della loro sommersione per la risalita olocenica del mare; in altri casi i depositi di spiaggia poggiano sull’attuale piattaforma di abrasione marina, in via di formazione; c) più cicli di depositi colluviali disposti lungo pendii a componente argillosa o in tratti di versante costituiti da detriti, poggiati su superfici di erosione subaerea prodotte dal dilavamento; d) detriti di falda e accumuli di crollo deposti ai piedi dei versanti su superfici di non deposizione o di erosione subaerea; e) corpi di frana e depositi gravitativi in genere poggiati lungo locali superfici di distacco o superfici di separazione. in relazione alla loro recente età (fine pleistocene superiore – attuale), i terreni di questo sintema costituiscono i depositi più diffusi e di maggiore estensione. il limite inferiore è dato da superfici di varia genesi, fra loro comunque correlabili, che hanno avuto origine durante l’ultima fase di risalita del mare, al passaggio fra il pleistocene superiore e l’olocene (ois 2-1). superfici di inconformità di rango inferiore, di età olocenica, interessano a varie altezze stratigrafiche i depositi del sintema. il limite superiore è l’attuale superficie topografica. la località-tipo proposta è una sezione lungo il versante nord-occidentale di poggio maria (area di capo plaia), dove è esposto un pacco di depositi colluviali olocenici. questi depositi si sovrappongono a detriti stratificati e cementati del sintema di raffo rosso lungo una superficie di erosione subaerea scavata dalle acque dilavanti. 359 fig. 12 – versante occidentale di montagna raffo rosso. detriti stratificati e cementati (sintema di raffo rosso). western slope of montagna raffo rosso. stratified slope deposits (raffo rosso synthem). unità a limiti inconformi utilizzate per la cartografia dei depositi ... 6. conclusioni lo studio dettagliato dei depositi marini, paralici e continentali del quaternario della sicilia nord-occidentale condotto nell’ambito del progetto carg, ha consentito sia di definire un quadro organico e sintetico delle successioni di terreni qui affioranti, sia di riconoscere, al loro interno, numerose superfici di discontinuità, alcune delle quali di importanza regionale. le superfici di importanza regionale, alcune essenzialmente continue altre frammentarie ma correlabili anche a grande distanza, hanno a loro volta permesso la definizione di sette ubsu del rango di sintema che ricoprono un arco di tempo che va dal pleistocene inferiore all’attuale (figg. 4, 13). questi sintemi sono rappresentativi dei depositi quaternari della sicilia nord-occidentale; essi sono stati cartografati in numerosi fogli geologici 1:50.000 del progetto carg in fase di allestimento per la stampa (figg. 1 e 2). l’analisi dei corpi rocciosi e dei limiti inconformi suggeriscono importanti cambiamenti ambientali nella sicilia nord-occidentale durante il quaternario (agnesi et al., 1998; agnesi et al., 2000b). questi cambiamenti possono essere ritenuti cause (dirette o indirette) dell’innesco di peculiari processi di erosione e/o sedimentazione responsabili della genesi delle discontinuità di importanza regionale e dei corpi sedimentari riconosciuti. importanti eventi tettonici di fagliazione a blocchi o sollevamento, brusche fluttuazioni climatiche o l’interazione di eventi tettonici e climatici, sono i fattori principali all’origine delle modificazioni ambientali. un evento tettonico del pleistocene inferiore, responsabile della genesi di faglie a forte componente distensiva (rigetti verticali dell’ordine del centinaio di metri) e del conseguente ribassamento, al di sotto del livello del mare, di alcuni grandi blocchi della sicilia settentrionale, sembra il fattore che ha consentito l’innesco di processi di erosione, sommersione e, al tempo stesso, di sedimentazione marina, che hanno prodotto, rispettivamente, la piattaforma di abrasione, l’annegamento di originarie superfici di erosione subaerea e i sovrastanti depositi del sintema di marsala. eventi climatici freddi, con il livello marino stabilizzato a quote inferiori rispetto all’attuale, sono le cause che hanno consentito potenti accumuli di depositi eolici e di detriti stratificati e cementati dei sintemi di polisano e di raffo rosso. in entrambi i casi, questi depositi poggiano su superfici di non deposizione coincidenti con le antiche superfici topografiche della fase iniziale degli eventi freddi. eventi climatici essenzialmente semiaridi hanno favorito lo sviluppo di processi di dilavamento e la produzione di quantità più o meno abbondanti dei depositi colluviali costituenti parte dei sintemi di marsala, della piana di partinico, di barcarello e di raffo rosso; nel caso del sintema di barcarello, il dilavamento ha assunto un’importanza tale da produrre una superficie di erosione subarea di estensione regionale. tali processi hanno anche contribuito allo smantellamento o alla parziale rielaborazione di preesistenti sedimenti ancora sciolti o poco cementati; questo meccanismo spiegherebbe l’assenza di detriti cementati e stratificati e, più in generale, di altri accumuli continentali riferibili a più antichi eventi climatici freddi o caldi del pleistocene medio. l’interazione fra movimenti tettonici di sollevamento e fasi di stazionamento alto del mare è invece responsabile della formazione dei diversi ordini di terrazzi marini e di terrazzi fluviali, che si sviluppano dalle maggiori alle minori quote e sulle cui superfici giacciono i corpi sedimentari dei sintemi della piana di partinico, di barcarello e dell’imera settentrionale. l’ultima risalita del livello del mare e le condizioni climatiche attuali hanno determinato lo sviluppo della superficie limite inferiore e l’accumulo dei depositi del sintema di capo plaia. ringraziamenti ricerca condotta con fondi: prin miur 2006 e carg (r. catalano); prin miur 2007 e fondi di ateneo 2005, 2006 e 2007 dell’università degli studi di palermo (v. agnesi). si ringraziano i referee maurizio d’orefice e un anonimo per l’attenta lettura del manoscritto, le critiche pertinenti, le puntuali osservazioni e gli utili suggerimenti che hanno contribuito alla stesura definitiva del lavoro. 360 fig. 13 rapporti tra le unità a limiti inconformi della sicilia nord-occidentale: 1. sintema di capo plaia (stadi isotopici 2-1); 2. sintema di raffo rosso (stadi isotopici 4-2); 3. sintema di barcarello (stadio isotopico 5); 4. sintema di polisano (stadio isotopico 6); 5. sintema della piana di partinico (pleistocene medio); 6. sintema dell’imera settentrionale (pleistocene medio e superiore); 7. sintema di marsala (pleistocene inferiore); 8. substrato pre-quaternario. geometric relationships among unconformity-bounded stratigraphic units of nw sicily. 1. capo plaia synthem (isotope stages 2-1); 2. raffo rosso synthem (isotope stages 4-2); 3. barcarello synthem (isotope stage 5); 4. polisano synthem (isotope stage 6); 5. piana di partinico synthem (middle pleistocene); 6. imera settentrionale synthem (middle and upper pleistocene); 7. marsala synthem (lower pleistocene); 8. pre-quaternary substrate. c. di maggio et al. lavori citati abate b., incandela a., nigro f. & renda p. (1998) plio-pleistocene strike-slip tectonics in the trapani mts. (nw sicily) boll. soc. geol. it., 117, pp. 555-567. agate m., catalano r., infuso s., lucido m., mirabile l. & sulli a. (1993) structural evolution of the northern sicily continental margin during the pliopleistocene – in: max m. d. & colantoni p. (eds.), geological development of the sicilian-tunisian platform, unesco rep. mar. sci., 58, pp. 25–30. agate m., beranzoli l., braun t., catalano r., favali p., frugoni f., pepe f., smriglio g. & sulli a. (2000) the 1998 offshore nw sicily earthquakes in the tectonic framework of the southern border of the tyrrhenian sea – mem. soc. geol. it., 55, pp. 103-114. agnesi v., macaluso t. & masini f. (1998) l’ambiente e il clima della sicilia nell’ultimo milione di anni – in: tusa s. (ed.), prima sicilia: alle origini della società siciliana, ediprint, siracusa, 1, pp. 31-56. agnesi v., di maggio c., macaluso t., madonia g. & rotigliano e. (2002) schema geomorfologico della penisola di capo s. vito (sicilia nord-occidentale) speleologia iblea, 10, pp. 37-47. agnesi v., de cristofaro d., di maggio c., macaluso t., madonia g. & messana v. (2000a) morphotectonic setting of the madonie area (central northern sicily) mem. soc. geol. it., 55, pp. 373-379. agnesi v., di maggio c., macaluso t., masini f., petruso d. & simonelli c. (2000b) quaternary environmental-climatic changes in sicily mem. soc. geol. it., 55, pp. 339-344. antonelli m., franciosi r., pezzi g., querci a., ronco g. p. & vezzani f. (1991) paleogeographic evolution and structural setting of the northern side of the sicily channel mem. soc. geol. it., 41, pp. 141-157. antonioli f., puglisi c,, reitano c. & tusa s. (1998) evoluzione geomorfologica pleistocenica del settore costiero di s. vito lo capo (tp): rapporti tra neotettonica, eustatismo e comunità preistoriche mem. descr. carta geol. d’it., 52, pp. 251-257. antonioli f., cremona g., puglisi c., silenzi s., valpreda e. & verubbi v. (1999) quantitative assessment of post tyrrhenian differential crustal movements in a mediterranean coastal area (s. vito – sicily – italy) – phys. chem. earth (a), 24 (4), pp. 343-347. bada j. l., belluomini g., bonfiglio l., branca m., burgio e. & delitala l. (1991) isoleucine epimerization ages of quaternary mammals from sicily il quaternario, 4 (1a), pp. 49-54. battaglia a. & ciofalo s. (1883) scoperte paleontologiche presso termini imerese (sicilia). lettera al prof. g. g. gemmellaro. boll. r. comit. geol. d’ it., roma, n. 9-10 (estratto), 3 pp. bello m., catalano r., merlini s. & sulli a. (2000) the apenninic chain in western and eastern sicily. a comparison atti conv. evoluzione geologica e geodinamica dell’appennino in memoria del prof. g. pialli, soc. geol. it., 1, pp. 25-26. bellon h., coulon c. & edel j. (1977) lé deplacement de la sadaigne: synthèse de donneés géocronologiques, magnetiques et paléomagnétiques. bull. soc. geo.fr., 19 (7), pp. 825-831. belluomini g. & bada j. l. (1985) isoleucine epimerization ages of the dwarf elephants of sicily . geology, 13, pp. 451-452. bianchi f., carbone s., grasso m., invernizi g., lentini f., longaretti g., merlini s. & mostardini f. (1989) sicilia orientale: profilo geologico nebrodi–iblei. mem. soc. geol. it., 38, pp. 429-458. bloom a. l. & yonekura n. (1985) coastal terraces generated by sea-level change and tectonic uplift in: woldenberg m. j. (ed.), models in geomorphology, pp. 139-154. bonfiglio l. & burgio e. (1992) significato paleoambientale e cronologico delle mammalofaune pleistoceniche della sicilia in relazione all’evoluzione paleogeografica ii quaternario, 5 (2), pp. 223-234. bonfiglio l., agnesi v., masini f. & di maggio c. (2004) quaternary eustatic fluctuations and biochronology of vertebrate-bearing deposits correlated with marine terraces in sicily 32nd international geological congress, field trip guide book, 1, b07, 36 pp. bonfiglio l., di maggio c., marra a. c., masini f. & petruso d. (2003) bio-chronology of pleistocene vertebrate faunas of sicily and correlation of vertebrate bearing deposits with marine deposits il quaternario, 16 (1bis), pp. 107-114. bonfiglio l., mangano g., marra a. c., masini f., pavia m. & petruso d. (2002) pleistocene calabrian and sicilian paleobioprovinces geobios, mem. sp., 24, pp. 29-39. bonifay e. & mars p. (1959) le tyrrhénien dans le cadre de la chronologie quaternaire méditerranéenne bull. soc. geol. de fr., ser. 7, 1, pp. 62-78. boschian g. (2002) note gearcheologiche sul territorio di himera in: belvedere o., bertini a., boschian g., burgio a., contino a., cucco r. m. & lauro d., himera iii.2. prospezione archeologica nella valle dell’imera. università degli studi di palermo, libreria editrice l’erma di bretschneider, roma, pp. 49-62. brugal j. p. (1987) cas de «nanisme» insulaire chez l’aurochs in: 112th congrès national des sociétés des savants, lyon, 2, pp. 53-66. buccheri g. (1966) contributo alla conoscenza della malacofauna di un terrazzo marino presso palermo atti acc. gioenia di sc. nat. in catania, catania, 142, pp. 329-332. burgio e. & cani m. (1988) sul ritrovamento di elefanti fossili ad alcamo (trapani, sicilia) il naturalista sicil., s. 4, 12 (3-4), pp. 87-97. burgio e. & fiore m. (1997) mustelercta arzilla (de gregorio, 1886) elemento villafranchiano nella fauna di monte pellegrino (palermo, sicilia) il quaternario, 10 (1), pp. 65-74. burgio e., di patti c., fischetti l. & galletti l. (1989) primi ritrovamenti di mammiferi fossili pleistocenici nella penisola di capo s. vito (trapani). in: agnesi v., macaluso t. & ulzega a. (eds.) guida alle escursioni, gruppo nazionale geografia fisica e geomorfologia, pp. 69-72. calvi f., contino a., cusimano g., di cara a., frias forcada a., hauser s. & pellerito s. (2000) hydrostructures related to the piana di palermo 361unità a limiti inconformi utilizzate per la cartografia dei depositi ... aquifers and their hydrogeochemical characteristics mem. soc. geol. it., 55, pp. 473-481. catalano r. & d’argenio b. (1978) an essay of palinspastic restoration across the western sicily – geol. rom., 17, pp. 145-159. catalano r. & d’argenio b. (1982) schema geologico della sicilia occidentale in: r. catalano & b. d’argenio (eds.) guida alla geologia della sicilia occidentale, guide geologiche regionali, mem. soc. geol. it., suppl. a, 24, pp. 9-41. catalano r., merlini s. & sulli a. (2002) the structure of western sicily, central mediterranean. petroleum geoscience, 8, pp. 7-18. catalano r., di stefano p., sulli a., vitale f. p. (1996) paleogeography and structure of the central mediterranean: sicily and its offshore area tectonophysics, 260, pp. 291–323. catalano r., franchino a., merlini s. & sulli a. (2000) central western sicily structural setting interpreted from seismic reflection profiles mem. soc. geol. it., 55, pp. 5-16. catalano r., di stefano e., sulli a., vitale f. p., infuso s. & vail p. r. (1998) sequences and system tracts calibrated by high-resolution bio-chronostratigraphy: the central mediterranean pliopleistocene record – sepm, spec. publ., 60, pp. 115-177. chang k. h. (1975) concepts and terms of unconformity-bounded units of formal stratigraphic units of distinct category – geol. soc. america bull., 86, pp. 1544-1552. channel j. e. t., d’argenio b. & horvath f. (1979) adria, the african promontory, in mesozoic mediterranean paleogeography earth sc. rev., 15, pp. 213-292. cita m. b., capraro l., ciaranfi n., di stefano e., marino m., rio d., sprovieri r. & vai g. b. (2006) calabrian and ionian: a proposal for the definition of the mediterranean stages for the lower and middle pleistocene. episodes, 29 (2), pp. 107114. cita m. b., capraro l., ciaranfi n., di stefano e., lirer f., maiorano p., marino m., raffi i., rio d., sprovieri r., stefanelli s. & vai g. b. (2008) the calabrian stage redefined. episodes, 31 (4), pp. 408419. contino a. (2002) geologia e geomorfologia della bassa valle del fiume imera settentrionale in: belvedere o., bertini a., boschian g., burgio a., contino a., cucco r. m. & lauro d. (eds.), himera iii.2. prospezione archeologica nella valle dell’imera, università degli studi di palermo, libreria editrice l’erma di bretschneider, roma, pp. 25-48. contino a. (2005) – geologia urbana dell’abitato e della zona industriale di termini imerese (sicilia settentrionale) tesi di dottorato di ricerca in geologia, università degli studi di palermo, 214 pp. contino a. (2007) le grotte della rocca del castello in termini imerese (palermo) speleologia iblea, 12, pp. 255-264. contino a., giammarinaro m. s., vallone p., varsalona s. & zuccarello a. (2006) analisi stratigraficogeotecnica del settore meridionale della città di palermo finalizzata alla caratterizzazione di fattori di pericolosità sismica in esso presenti boll. soc. geol. it., 125, pp. 329-343. cosentino d. & gliozzi e. (1988) considerazioni sulla velocità di sollevamento di depositi eutirreniani dell’italia meridionale e della sicilia mem. soc. geol. it., 41, pp. 653-665. cottignoli a., boschian g., di maggio c., masini f. & petruso d. (2002) pedostratigraphic notes on the middle-late pleistocene of capo san vito peninsula (nw sicily) il quaternario, 15 (1), pp. 89-98. cremaschi m. & trombino l. (1998) eolianites, sea level changes and palaeowinds in the elba island (central italy) during late pleistocene – in: busacca a. j. (ed.), dust aerosols, loess soils and global change, washington state university college of agricolture and home economics, pullman, wa, pp. 131-134. de gregorio a. (1925) mammiferi quaternari di sicilia annales de géologie et de paléontologie, 43, pp. 3-18. dercourt j., zonenshain l. p., ricou l. e., kazmin v. g., le pichon x., knipper a. l., grandjacquet c., sbortshikov i. m., geyssant j., lepvrier c., pechersky d. h., boulin j., sibuet j. c., savostin l. a., sorokhtin o., westphal m., bazhenov m. l., lauer j. p. & biju-duval b. (1986) geologic evolution of the tethys belt from the atlantic to the pamirs since the lias tectonophysics, 123, pp. 241-315. di maggio c. (1997) assetto morfostrutturale ed evoluzione geomorfologica di un settore dei monti di palermo tesi di dottorato, università degli studi di napoli “federico ii”, biblioteche nazionali di roma e firenze,175 pp. di maggio c. (2000) – morphostructural aspects of the central northern sector of palermo mountains (sicily) mem. soc. geol, it., 55, pp. 353-361. di maggio c., incandela a., masini f., petruso d., renda p., simonetti c. & boschian g. (1999) – oscillazioni eustatiche, biocronologia dei depositi continentali quaternari e neotettonica nella sicilia nord-occidentale (penisola di s. vito lo capo – trapani) il quaternario, 12 (1), pp. 25-50. d’orefice m., graciotti r. & capitanio f. (2007) le eolianiti dell’isola d’elba: i depositi del promontorio del m. calamita e del golfo di viticcio il quaternario, 20 (1), pp. 21-44. di stefano e. & rio d. (1981) biostratigrafia a nannofossili e biocronologia del siciliano nella località tipo di ficarazzi acta naturalia dell’ateneo parmense, 17, pp. 97-111. fabiani r. (1941) tracce di tirreniano (strati a strombus bubonius lk.) entro la città di palermo boll. soc. sc. nat. e econ. di palermo, 23, pp. 3-8. faccenna c., davy p., brun j. p., funiciello r., giardini d., mattei m. & nalpas t. (1996) the dynamics of back-arc extension: an experimental approach to the opening of the tyrrhenian sea geophys j. int., 126, pp. 781795. gignoux m. (1913) les formations marines pliocènes et quaternaires de l’italie du sud et de la sicile ann. univ. lyon, n. s., 36 pp. gignoux m. (1926) les rivages et les faunes des mers pliocènes et quaternaires dans le méditerranée occidentale 13° congr. géol. intern., liège, 362 c. di maggio et al. compt. rend., 3, pp. 1447-1491. gueguen e., doglioni c. & fernandez m. (1998) lithospheric boudinage in the western mediterranean back-arc basin oceanographic literature review, 45, (7), pp. 1151. hearty p. j., miller g. h., stearns c. e. & szabo b. j. (1986) aminostratigraphy of quaternary shorelines in the mediterranean basin geol. soc. america bull., 97, pp. 850-858. hugonie g. (1979) l’évolution géomorphologique de la sicile septentrionale thése lettres (géomorphologie), univ. de paris-sorbonne, 2, pp. 565-884. hugonie g. (1982) mouvements tectoniques et variations de la morphogenèse au quaternaire en sicile septentrionale revue de géologie dynamique et géographie physique, 23, pp. 3-14. issc international subcommission on stratigraphic classification (1994) international stratigraphic guide: a guide to stratigraphic classification, terminology and procedure – 2nd edition, gsa, boulder, 214 pp. malinverno a. & ryan w. b. f. (1986) extension in the tyrrhenian sea and shortening in the apennines as result of arc migration driven by sinking of the lithosphere tectonics, 5, pp. 227-245. masini f., petruso d., bonfiglio l. & mangano g. (2008) origination an extinction patterns of mammals in three central western mediterranean island from the late miocene to quaternary – quatern. int., 182, pp. 63–79. mauz b. & renda p. (1991) evoluzione tettono-sedimentaria del bacino plio-pleistocenico di castellammare del golfo (sicilia nord-occidentale) mem. soc. geol. it., 47, pp. 167-180. mauz b., buccheri g., zoller l. & greco a. (1997) -middle to upper pleistocene morphostructural evolution of nw sicily coast: thermoluminescience dating and paleontological-stratigraphical evaluations of littoral deposits palaeogeography, palaeoclimatology, palaeoecology, 128, pp. 269-285. nigro f., renda p. & arisco g. (2000) tettonica recente nella sicilia nord-occidentale e nelle isole egadi boll. soc. geol. it., 119 (2), pp. 307-319. ottmann f. & picard j. (1954) contribution à l’étude du quaternaire des régions de palerme et de milazzo (sicile) bull. soc. géol. de france, s. 6, 4 (4-6), pp. 395-407. patacca e., scandone p., giunta g. & liguori v. (1979) mesozoic paleotectonic evolution of the ragusa zone (southeastern sicily) geol. romana, 18, pp. 331-369. radtke u. (1989) – marine terrassen und korallenriffe – das problem der quartären meeresspiegelschwankungen erläutert an fallstudien aus chile, argentinien und barbados düsseldorfer geogr. schr., 27, 245 pp. rehault j.p., moussat e. & fabbri a. (1987) structural evolution of the tyrrhenian back-arc basin marine geology, 74 (1-2), pp. 123-150. retallack g. j. (1990) soils of the past unwinhyman, london, 520 pp. rhodes e. j. (1996) esr dating on tooth enamel in: basile b. & chilardi s. (eds.), siracusa, le ossa dei giganti. lo scavo paleontologico di contrada fuico, pp. 39-44. ruggieri g. (1967) quadro sintetico del quaternario marino fra castellammare ed altavilla (palermo) atti acc. gioenia sc. nat. in catania, suppl. sc. geol., s. 6, 18, pp. 345-355. ruggieri g. (1971) calabriano e siciliano nei dintorni di palermo. parte i riv. min. sic., 130-132, pp. 160-171. ruggieri g. (1973) ostracofauna delle calcareniti bianche quaternarie delle falde (palermo) riv. min. sic., 142-144, pp. 160-170. ruggieri g. (1978) una trasgressione del pleistocene inferiore nella sicilia occidentale il nat. sic., 4 (12), pp. 159-171. ruggieri g. & milone g. (1974) la macrofauna del tirreniano di tommaso natale (palermo) boll. soc. paleont. it., 12, pp. 217-222. ruggieri g. & sprovieri r. (1975) la definizione dello strato tipo del piano siciliano e le sue conseguenze riv. min. sic., 151-153, pp. 8-14. ruggieri g. & sprovieri r. (1983) recenti progressi nella stratigrafia del pleistocene inf. boll. soc. paleont. it., 22 (3), pp. 315-321. ruggieri g., buccheri g. & rendina m. (1968) segnalazione di tirreniano fossilifero a trapani riv. min. sic., 112 114, pp. 1-4. ruggieri g., rio d. & sprovieri r. (1984) remarks on the chronostratigraphic classification of lower pleistocene boll. soc. geol. it., 103, pp. 251-259. ruggieri g., buccheri g., greco a. & sprovieri r. (1975a) un affioramento di siciliano nel quadro della stratigrafia del pleistocene inferiore boll. soc. geol. it., 94, pp. 889-914. ruggieri g., unti a., unti m. & moroni m. a. (1975b) la calcarenite di marsala (pleistocene inferiore) e i terreni contermini boll. soc. geol. it., 94, pp. 1623-1657. ruhe r. v. (1959) stone lines in soils soil science, 84, pp. 223–231. scinà d. (1831) rapporto sulle ossa fossil i di maredolce e degli altri contorni di palermo dalla reale tipografia di guerra, palermo. servizio geologico d’italia (2001) indicazioni per il rlevamento del quaternario continentale. circolare carg, http://www.apat.gov.it/site/it-it/progetti/ progetto_carg_-_cartografia_geologica_e_geotematica/rilevamento_quaternario_continentale/ shackleton n. j. (1995) new data on the evolution of pliocene climatic variability in: vraba e. et al. (eds.) palaeoclimate and evolution, yale university press, pp. 242-248. tongiorgi e. & trevisan l. (1953) – excursion en sicile iv int. congr. inqua, livret guide, 34 pp. ulzega a. & hearty p. j. (1986) geomorphology, stratigraphy and geochronology of late quaternary marine deposits in sardinia zeitschrift für geomorphologie supplement band, 62, pp. 119-129. vaufrey r. (1929) les éléphants nains des iles méditerranéens et la question des isthmes pléistocènes arch. dell’ inst. de paleont. humaine, memoire, 6, 220 pp. 363 ms. ricevuto il 27 aprile 2009 testo definitivo ricevuto il 10 luglio 2009 ms. received: april 27, 2009 final text received: july 10, 2009 unità a limiti inconformi utilizzate per la cartografia dei depositi ... microsoft word 01_bergami_lm02.doc available online http:/amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 26 (1), 2013, 5-14 ionian sea surface temperature during the sapropel s1 deposition inferred from planktonic foraminiferal mg/ca and δ18o caterina bergami1, lucilla capotondi1, daniela salvagio manta2, mario sprovieri2, luigi vigliotti1 1 cnr istituto di scienze marine, ismar, bologna, italy 2 cnr istituto per l’ambiente marino costiero, iamc, capo granitola, trapani, italy corresponding author: caterina bergami <caterina.bergami@ismar.cnr.it > abstract: temperature variations during the holocene sapropel s1 has been investigated by means of a multiproxy study on core et99-m11 collected in the western ionian sea at a water depth of 2800 m. sea surface temperatures (sst) reconstruction has been made by measuring oxygen stable isotopes (δ18o) and mg/ca ratios on the planktonic foraminifers globigerinoides ruber and globigerina bulloides. results indicate that the investigated interval was characterized by water temperature increase, both at surface and in the sub-surface layers. paleotemperature reconstruction based on mg/ca ratios shows higher temperature values during the two sub-units (s1a and s1b) of the sapropel s1, and lower during the sapropel interruption, the latter being synchronous to the well known 8.2 cold event. in addition, a number of several short-term cold oscillations which can be correlated with millennial scale climate events in the north atlantic region is evidenced. this indicates a possible atmospheric connection between the central mediterranean and the north atlantic region and the strong relation between climate and oceanographic changes during the sapropel deposition. keywords: sapropel s1, planktonic foraminifera, paleotemperature, central mediterranean, mg/ca. 1. introduction organic-rich layers, named sapropels, characterize the neogene sediments of the mediterranean sea (olausson, 1961; cita et al., 1977). these sediments contain abundant and well-preserved planktonic microfossils that make these intervals particularly suitable for high-resolution paleoclimatic reconstructions. planktonic foraminifera have proven to be excellent indicators of sea surface temperature, salinity, food availability and they have been used to detect longand short-term climate changes in the mediterranean sea. actually, the isotopic and trace elements composition of foraminifera shells provide a reliable record of seawater chemistry and as such are widely used by palaeoceanographers to reconstruct ocean and climate variability on geological timescales. specifically, the δ18o signal of planktonic foraminifera records the combined effects of global ice volume, sea surface temperature, and regional evaporation/precipitation budgets, while the mg/ca ratio of foraminiferal tests mainly depends on the temperature of the water in which the foraminifer calcifies, as basically deduced from cultivating work and field studies (e.g., nürnberg, 1995, 2000; nürnberg et al., 1996, 2000; lea et al., 1999; mashiotta et al., 1999; elderfield & ganssen, 2000: dekens et al., 2002). foraminiferal mg/ca seawater thermometry is a rapidly developing and increasingly widely used tool for palaeoceanographic reconstructions (nürnberg et al., 1996; rosenthal et al., 1997; lea et al., 1999; elderfield & ganssen, 2000; lea at al., 2000; anand et al., 2003; barker et al., 2005). the exponential increase of bulk test mg/ca composition with seawater temperature is well established from deep-sea sediment core top (rosenthal et al., 1997; hastings et al., 1998; elderfield & ganssen, 2000; lea at al., 2000; rosenthal et al., 2000; dekens et al., 2002; rosenthal & lohmann, 2002). however, the incorporation of mg during shells calcification is a complex and imperfectly known mechanism with potential species‐dependent effects and non‐temperature biases such as those associated to carbonate ion content of seawater (russell et al., 2004; kisakürek et al., 2008) or salinity (nürnberg et al., 1996; lea et al., 1999; kisakürek et al., 2008; mathien‐blard & bassinot, 2009; arbuszewski et al., 2010). although not numerically abundant, studies in the mediterranean evidenced some problems in the application of this method. ferguson et al. (2008) showed a significant response of foraminiferal mg/ca to salinity in the mediterranean sea revealing a clear relationship (16% mg/ca increase per psu) although associated to a large mg/ca data scattering. this result was later confirmed by sabbatini et al. (2011), on the mg/ca ratios characterizing the planktonic species g. ruber from the whole mediterranean sea. hoogakker et al. (2009) and boussetta et al. (2011), who worked on core tops from the red sea and from the mediterranean basin respectively, suggested that anomalously high mg/ca ratios of planktonic foraminifers from the mediterranean sea, could be also related to early diagenetic, high mg‐calcite overgrowths formed from caco3 supersaturated interstitial seawater. also, van raden et al. (2011) suggested that the high mg/ca measured on two planktonic foraminifers (globigerina bulloides and globorotalia inflata) in the western mediterranean sea is due to inorganic calcite coating on the foraminiferal tests. finally, kontakiotis et al. bergami c. et al. 6 (2011) presented new aegean sea results which reveal mg/ca values that were unreasonably high to be explained by temperature or salinity variations alone, confirming that foraminiferal mg/ca is affected by diagenesis. studies regarding foraminiferal mg/ca ratios during sapropels deposition are rare, however ní fhlaithearta et al. (2010) reliably constrained the magnitude and duration of the sapropel s1 interruption and other shortterm cooling events using mg/ca thermometry from the benthonic microfauna in the aegean sea. here we present oxygen isotopes and mg/ca ratios data from planktonic foraminifera globigerina bulloides and globigerinoides ruber from sediments of sapropel s1 in the ionian sea, with the aim to reconstruct paleotemperature and paleoenvironmental changes which occurred during the sapropel s1 deposition in this basin. 2. regional setting the ionian sea is a transition basin influenced by the flow and transformation of the major water masses constituting the intermediate and deep thermohaline cell of the eastern mediterranean conveyor belt (malanotterizzoli et al., 1997; napolitano et al., 2000). moreover, the ionian circulation plays an important role in the redistribution of the different water masses to adjacent seas (gačić et al., 2010). at the near-surface level, which is the most important part of the water column with regard to the biological production, the modified atlantic water (maw) enters the western ionian basin, the intermediate layer is influenced by salty and warm waters coming from the levantine and aegean basins (liw: levantine intermediate waters), whilst dense and oxygenated waters, mainly of adriatic origin, spread into the ionian deep layer. the choice of the ionian basin for this kind of highresolution study is driven by the fact that its oceanographic setting is critical for the deep-water formation of the mediterranean basin and the oceanographic conditions, responsible of the sapropel deposition, are certainly influenced by the deep-sea ventilation. moreover, concerning the planktonic foraminiferal distribution, this basin appears as a transitional area between the southwestern and eastern mediterranean area (pujol & vergnaud grazzini, 1995). 3. material and methods the sedimentary core et99m11 has been collected in the ionian sea (36°44’04”n, 15°50’94”e, 2800 m below sea level; fig 1). in the core, the sapropel s1 interval is characterized by black-grey sediments extending from 54 to 22 cm depth in section iv of the core (fig. 1). 3.1. age model the age model is that provided by vigliotti et al. (2011 and table 2 therein) based on four 14c ams da fig. 1 location map of the core et99m11 and section iv of the core with the indication of the sapropel s1 position. 450 m resolution dtm retrieved from http://portal.emodnet-hydrography.eu/emodnetportal/index.jsf#. the sapropel s1 in the ionian sea 7 tings integrated with tephra layers and planktonic foraminiferal bioevents. on this base sapropel s1, is chronologically confined between 10.4 and 5.7 cal ka bp and appear synchronous with analogous layer reported in the eastern mediterranean sea. in detail, three different time intervals have been recognized: the s1a sub-unit spanning from 10.4 to 8.3 cal ka bp, the sapropel interruption from 8.3 to 7.8 cal ka bp, and the s1b sub-unit from 7.8 to 5.7 cal ka bp (vigliotti et al., 2011). 3.2. foraminiferal species used and their ecological features g. ruber is a species living in the surface mixed layer and occurring in subtropical to tropical latitudes (deuser, 1987; ravelo & fairbanks, 1992; niebler et al., 1999). it is found at the base of the mixed layer (field, 2004) and even has moderate abundances within the thermocline. in contrast to other species, g. ruber has a low-slope response to a deepening isotherm, which makes this species the most suitable to document nearsurface temperatures when other species are living deeper (field, 2004; tedesco et al., 2007). g. bulloides has a wide geographic distribution, ranging from the poles to the low latitudes (niebler et al., 1999; schmidt & mulitza, 2002). this taxon most commonly lives in the surface mixed layer (fairbanks et al., 1982; hemleben et al., 1989), but it also occurs within the thermocline (field, 2004). each species records the temperature variations of the water mass in which it thrives. hence, the warmest water mass is the one in which g. ruber lives, and corresponds to the summer mixed layer (pujol & vergnaudgrazzini, 1995; rohling et al., 2004). the water mass recorded by g. bulloides is assumed to be a mixture between the late spring/early summer surface layer and deeper waters upwelled during those months at 50-100 water depth (pujol & vergnaud-grazzini, 1995; barcena et al., 2004; hernàndez-almeida et al., 2005). 3.3. trace elements analysis (icp-ms/icp-aes) forty to sixty specimens of g. ruber (var. alba) were selected from the > 150 µm size fraction (26 samples) discarding specimens visibly contaminated by ferromanganese oxides. the foraminifera tests were next cleaned using a multistep trace metal protocol including reductive cleaning with buffered hydrazine (boyle & keigwin, 1985). mg/ca ratios were measured on a inductively coupled plasma mass spectrometer varian icp-ms and an inductively coupled plasma atomic emission spectrophotometer varian vista mpx at the geochemistry laboratory of the iamc-cnr (naples). in detail, the tests were gently crushed and then cleaned following procedures modified from lea & boyle (1993). briefly, samples were ultrasonically cleaned four times with ultrapure water (> 18 mω) and twice with methanol. metal oxide coatings were reduced in a solution consisting of anhydrous-hydrazine, citric acid, and ammonium hydroxide and organic matter was oxidized in a solution of hydrogen-peroxide and sodiumhydroxide. all the water samples were treated under a laminar air flow clean bench to minimize contamination risks and the sampling materials were cleaned with high purity grade reagents. the remaining tests material was then dissolved in 0.1n nitric acid and simultaneously analysed for magnesium with the varian icp-ms inductively coupled plasma-mass spectrometer. a multielement standard was prepared with icp-ms grade high-purity standards. based on repeated analyses of the standard and samples over several runs, on different days, the 2s error in the icp analyses is estimated at ±5%. replicate analyses on five samples yielded an average external precision (1σ) of about 5%. calcium was measured with a varian vista mpx inductively coupled plasma-optical emission spectrometer (icp-oes). metal to calcium ratios were determined from intensity ratios with an external matrix-matched standard using the method developed by rosenthal et al. (1999). the cleaning protocol and analytical approach used in this study is also comparable to methods reported by elderfield & ganssen (2000). 3.4. isotopic analyses the oxygen isotopic composition of g. ruber (var. alba) and g. bulloides were obtained from the sediment core. about 10-15 specimens in the > 150 µm size fraction were analyzed per sample (41 samples). samples were measured with an automated continuous flow carbonate preparation gasbench ii device and a thermoelectron delta plus xp mass spectrometer at the laboratory of geochemistry of the iamc-cnr (naples). acidification of the samples was performed at 50°c. an internal standard (carrara marble with δ18o = 2.43‰ vs. vpdb and δ13c = 2.43‰ vs. vpdb) was run every six samples and the nbs19 international standard was measured every 30 samples. standard deviations of carbon and oxygen isotope measures were estimated at 0.1 and 0.08‰, respectively. all the isotope data are reported in δ‰ versus vpdb. 3.5. determination of calcification temperatures 3.5.1. temperature estimates from δ18oforam to obtain the calcification temperatures we have used oxygen isotope data of g. ruber and g. bulloides (δ18oforam) and of the water masses in which they calcify (δ18oseawater). different equations have been proposed to convert δ18oforam in sst but based on what reported on grauel & bernasconi (2010) on sediment surface samples, g. ruber yield the most reliable calcification temperature applying the shackleton (1974) palaeotemperature equation. in fact, according to the authors, who made a core-top study on δ18o temperature reconstructions of g. ruber (white) and u. mediterranea in the central mediterranean, reliable temperatures were produced using the shackleton (1974) equation, whereas too low temperatures compared to the recent temperature conditions (on average ~4.4°c lower than predicted by shackleton (1974) equation) were produced using the mulitza et al. (2003) equation. the equation of shackleton (1974) is: where tiso is the calcification temperature and δ18oforam and δ18oseawater are reported vs. vpdb. δ18oseawater values for sapropel time are those reported in kallel et al. (1997 and table 4 therein). bergami c. et al. 8 values of δ18oseawater have been converted to vienna standard mean ocean water (v-smow)‰ using the following equation:   3.5.2 temperature estimates from mg/ca ratios although in the mediterranean sea seems to be no significant correlation between mg/ca and δ18o‐derived calcification temperatures (ferguson et al., 2008; sabbatini et al., 2011), several studies suggested an exponential correlation between mg/ca ratios from g. ruber shells and sst (e.g. elderfield & ganssen, 2000; anand et al., 2003; dekens et al., 2002). generally, the adopted mg/ca-sst equation is that reported by elderfield & ganssen (2000) based on multispecies calibration:   where tmg/ca is the calcification temperature and mg/ca is measured in mmol/mol. 4. results 4.1. δ18oforam and sst the oxygen isotope data measured on the two species of planktonic foraminifera are illustrated vs. age in fig. 2. the δ18o values from g. ruber and g. bulloides during the investigated period average -0.56‰ and 1.12‰, respectively (fig. 2) with associated variances of 0.46‰ and 0.62‰. g. ruber shows lower values than g. bulloides but the two records show the same trend during the investigated period, with a general lightening during sapropel deposition, and particularly during the s1a subunit. the g. ruber calcification temperature, characterized by a general increase throughout the whole investigated period, ranges between 22.8 and 14.1°c with an average value of 20°c, while g. bulloides records a similar trend with an isotopic temperature ranging between 16.3 and 5.0°c, with an average value of 12.7°c (fig. 2). the heaviest isotopic values throughout the record are observed at 11.6, 10.7, 10.0, 9.5, 8.2, and 6.4 cal ka bp suggesting colder conditions during these intervals. fig. 2 down-core oxygen isotope records (‰ versus vpdb) and calculated isotopic temperature in °c in g. ruber var. alba and g. bulloides for core et99m11 across the sapropel s1. the grey areas, representing the extent of the two sub-units of the sapropel s1, are from vigliotti et al. (2011). b5-b7 label bond cycles (bond et al., 1997; 2001). the sapropel s1 in the ionian sea 9 4.2. mg/ca ratios and sst estimates during the interval of sapropel deposition mg/ca ratios range between 1.8 and 4.7 mmol/mol (fig. 3) with an average value of 3.37 mmol/mol. the estimated sst values range between 22.3 and 15.7°c during the subunit s1a, with an average value of 20°c, and between 22.4 and 18.6°c (average value 18.6°c) during the subunit s1b, while during the interruption the average value is 14.8°c (fig. 4). the warmest period is observed at the beginning of the sapropel s1 deposition, and throughout the interruption a gradual cooling took place, leading to another warming phase during the subunit s1b. 5. discussion 5.1. paleotemperature estimates and difference between the two proxies our results show temperatures comparable to those reported during the sapropel s1 by kallel et al. (1997). in detail, in the investigated period, both proxies record comparable temperatures in terms of average values, however there are some dissimilarities at a smaller scale: in fact, whereas the isotopic temperature after a sharp increase at 10 cal ka bp does not show great fluctuations, paleotemperature reconstruction based on mg/ca ratios shows higher values in the interval from 10 to 8.8 cal ka bp and from 6.6 to 6.3 cal ka bp during the deposition of the two sub-units of sapropel s1, and lower values in the interval from 8.8 to 7.2 cal ka bp, with the lowest temperature recorded at 8.2 cal ka bp corresponding to the sapropel interruption (fig. 4). in detail, based on calculated isotopic temperatures, the sapropel s1 interval was characterized by a general increase in water temperatures at the surface and in the sub-surface layers, as clearly evidenced by g. ruber and g. bulloides, respectively. the mean temperature estimate for g. ruber (20°c) is consistent with the growth temperature proposed by kallel et al. (1997 and table 4 therein) for the same species during the sapropel s1 deposition in the ionian basin. the sapropel sst is also taken to be equivalent to the modern one in the ionian basin and the growth temperature of g. ruber is found to correspond to the mean sst of the summer mixed layer (manca et al., 2004). this datum further supports that, during the sapropel interval, the ssts in the ionian sea were similar to the present ones. the amplitude of the temperature changes recorded by g. ruber is broad, up to 8°c from the warmest to the coldest values and is consistent with paleotemperature variations documented in the same area during the sapropel s1 deposition by emeis et al. (2000). this broad amplitude is due to the very thin summer mixed layer really sensitive to any runoff event or heating anomaly which would have great impact as compared with other thicker water masses (gonzalez-mora et al., 2008). the variability of the g. bulloides data are even wider than those of g. ruber (around up to 10°c of difference between the coldest and the warmest samples), this although the general trends are similar. the mean temperature estimate for g. bulloides (12.7°c) is cooler by about 2°c respect to that of today. as g. bulloides is prolific at depths below the thermocline (pujol & vergnaudgrazzini, 1995), the observed difference in temperature estimate respect to g. ruber suggest the presence of a marked thermocline or an increasing summer thermal gradient. moreover, the large gradient between the temperatures recorded by g. ruber and g. bulloides can be interpreted as related to their seasonality (pujol & vergnaud-grazzini, 1995) suggesting that the two different water masses remained isolated at the seasonal scale, due to a permanent seasonal stratification. the mean temperature estimate, based on mg/ca ratios, for g. ruber is consistent with the isotopic temperature during s1a subunit (20°c) while is cooler by about 1.5°c during s1b subunit (18.6°c). discrepancies between temperature estimates from mg/ca ratios and calculated isotopic temperature may be ascribed to the different variables influencing the two proxies. the oxygen isotopic temperatures are based on biogenic δ18oforam which is affected by δ18owater. the variability between the mg/ca and oxygen isotope temperature reconstructions of g. ruber may, in part, be explained by changes in δ18owater. in our reconstructions, we assumed a constant δ18owater during the entire investigated interval, but it is fig. 3 down-core mg/ca ratios of g. ruber var. alba for core et99m11 across the sapropel s1. the grey areas, representing the extent of the two sub-units of the sapropel s1, are from vigliotti et al. (2011). bergami c. et al. 10 reasonable that during the sapropel deposition the well documented enhanced run-off and the subsequent different evaporation/precipitation budget, and the presence at the surface of freshwater-diluted lenses influenced this value. on the contrary, mg/ca ratios in modern planktonic foraminifera are assumed and have been demonstrated to be predominantly a function of the temperature of the water in which they grew, while salinity is a secondary factors that exert influences on shell mg content, but not in the mediterranean, where several authors (ferguson et al., 2008; sabbatini et al., 2011 and references therein) suggested that mg/ca ratios can be strongly affected by the high salinity values typical of this basin. in detail, measured mg/ca values of planktonic foraminifera, collected in the eastern and central mediterranean basins, correlate poorly with the calcification temperatures but more significantly with calcification salinities, demonstrating that the salinity can be a primarily influencing factor in these environments. however, during the sapropel deposition, surface water salinity decreased and became almost homogeneous over the whole mediterranean basin with an average value for the ionian sea of 35.2 psu (kallel et al., 1997 and table 4 therein), which is close to that of the western mediterranean basin (e.g. alboran sea) where the mg/ca ratios are not influenced by the salinity regime (ferguson et al., 2008). then it is reasonable that, during the sapropel deposition, the salinity did not exert influences on shell mg content, being the mg/ca ratios primarily influenced by sst variations. in addition, we may exclude the possibility that post-deposition process or the presence of a mg‐rich calcite coating influences the results, firstly because sapropel layers are really conservative environments often characterized by the lack of bioturbation and often apparently high sedimentation rates. secondarily, we observed in our samples, that the sapropel microfauna fig. 4 δ18o and mg/ca g. ruber var. alba inferred temperature records from core et99m11. the grey areas, representing the extent of the two sub-units of the sapropel s1, are from vigliotti et al. (2011). open symbols represent mg/ca data, overlain with a line representing a 200 year gaussian smoothing. the sapropel s1 in the ionian sea 11 association was typically characterized, as observed by other authors (capotondi et al., 1999; negri et al., 1999), by the occurrence of specimens showing a very thin test structure, easily observed at the optical microscope, which point to a very good test preservation with no or few secondary calcite overgrowth. concluding, our data show that fluctuations in the mg/ca ratios are more pronounced than in the isotopic values suggesting a promising tool for paleotemperature reconstruction also in the mediterranean, but only when the influence of salinity will be entirely clarified. 5.2. mediterranean connection with the north atlantic ocean climate changes during the holocene have been gathering increasing attention because of the occurrence of millennial‐scale abrupt climate changes, of possible hemispheric extent, during this period (e.g., bond et al., 2001; gupta et al., 2003; mayewski et al., 2004), when the boundary conditions such as co2 concentration and ice volume were relatively constant and similar to the present ones. in the north atlantic, ice‐rafted debris (ird) events exhibit a distinct pacing on millennial‐scale during the holocene (bond et al., 2001). recently, several authors identified the expression of these events also in the sedimentary record of the mediterranean sea (e.g. cacho et al., 2001; frigola et al., 2007; rouis-zargouni et al., 2010; incarbona et al., 2008; 2010; vallefuoco et al., 2011; capotondi & vigliotti, 1999). comparison of our record of δ18oforam with north atlantic holocene millennial scale climatic variability (bond et al., 1997) allowed to highlight several shortterm cold oscillation at around 10.7, 9.5, and 8.2 cal ka bp comparable with the events numbered 7, 6, and 5 by bond et al. (2001; 1997) (fig.2). this indicates a possible atmospheric connection between the central mediterranean and the north atlantic region and the strong relation between climate and oceanographic changes during the sapropel s1 interval. one of these climatic features has been already documented by several authors in other areas of the mediterranean sea (e.g. rohling et al., 1997; de rijk et al., 1999; sangiorgi et al., 2003; vigliotti et al., 2011; asioli et al 1999; ariztegui et al., 2000), and was related to the so-called “8.2 event” (alley et al., 1997) and the associated δ18o increase of greenland ice cores. based on the isotopic temperature signal, during the three events the magnitude of the sea surface cooling is comparable to that proposed by bond et al. (1997) in cores from the north atlantic ocean, and does not exceed 2°c. based on the mg/ca temperature reconstruction, the cooling exceeded 2°c only during the event centred at 8.2 cal ka bp with a decrease in temperature of at least 5°c corresponding to the shift also proposed by alley et al. (1997) during this event. then in the studied core the mg/ca method evidences very sharp short time fluctuations much less evident with the isotope paleotemperature method. then, our data suggest a strong sensitivity of the central mediterranean basin, during the sapropel s1 time interval, to changes occurred in the north atlantic and therefore supports the high low latitude climatic mediterranean interplay also evidenced in colleoni et al. (2012) for the plio-pleistocene time interval. 6. summary a high-resolution investigation on the holocene sapropel s1 in the ionian sea was performed based on planktonic foraminifera geochemical data (stable oxygen isotopes and mg/ca ratios) proxies. this study documents promising results of the mg/ca paleothermometry applied to planktonic species. the first phase of the sapropel s1 was characterized by higher temperature, also consistent with the modern ones in the eastern mediterranean basin, while the second phase registered cooler temperature by about 2°c. during the sapropel interval, several cooling episodes, time equivalent to the millennial climatic variability in the north atlantic, were recognized at 10.7, 9.5, and 8.2 ka bp, the latter corresponding to the well known “8.2 event” and synchronous to the sapropel interruption. the climatic oscillations recorded by our study suggest an hemispheric-scale atmospheric connection in the central mediterranean basin. acknowledgements part of this study was funded by the projects sinapsi and ricerca spontanea a tema libero (rstl n. 154; “sapropels s1 e s5: archivi della variabilità climatica indotta dal regime monsonico”). we thanks m. coltelli, p. del carlo and l. vezzoli to provide core et99m11. we also thank alessandra negri and an anonymous rewiever who greatly improved the manuscript with their comments. this is the ismar contribution 1784. references alley r. b., mayewski p. a., sowers t., stuiver m., taylor k. c., clark p. u. (1997) holocene climatic instability: a prominent widespread event 8200 years ago. geology, 25, 483-486. anandp., elderfield h., conte m. h. (2003) calibration of mg/ca thermometry in planktonic foraminifera from a sediment tap time series. paleoceanography, 18(2), 1050, doi:10.1029/2002pa000846. arbuszewski j., demenocal p., kaplan a., farmer e. c. (2010). on the fidelity of shell‐derived δ18o seawater estimates. earth and planetary science letters, 300, 185-196, doi:10.1016/j.epsl.2010.10. 035.17. ariztegui d., asioli, a., lowe j. j., trincardif., vigliotti l., tamburini f., chondrogianni c., accorsi c.a., mazzanti m.b., mercuri a.m., van der kaars s., mckenzie j.a., oldfield f. (2000) palaeoclimate and the formation of sapropel s1: inferences from late quaternary lacustrine and marine sequences in the central mediterranean region. palaeogeography, palaeoclimatology, palaeoecology, 158(34), 215-240. doi:10.1016/s0031-0182(00)00051-1 asioli a., trincardi f., lowe j. j., oldfield f. (1999) short-term climate changes during the last glacial-holocene transition: comparison between mediterranean records and the grip event stratigbergami c. et al. 12 raphy. journal of quaternary science, 14(4), 373381. barcena m. a., flores j. a., sierro f. j., perez-folgado m., fabrés j., calafat a., canals m. (2004) planktonic response to main oceanographic changes in the alboran sea (western mediterranean) as documented in sediment traps and surface sediments, marine micropaleontology, 53, 423-445, doi:10.1016/j.marmicro.2004.09.009. barker s., cacho i., benway h.m., tachikawa k. (2005) planktonic foraminiferal mg/ca as a proxy for past oceanic temperatures: a methodological overview and data compilation for the last glacial maximum. quaternary science review, 24(7-9), 821-834. bond g., showers w., cheseby m., lotti r., almasi p., de menocal p., priore p., cullen h., hajdas i., bonani g. (1997) a pervasive millennial-scale cycle in north atlantic holocene and glacial climates. science, 278, 1257-1266, doi:10.1126/ science.278.5341.1257. bond g., kromer b., beer j., muscheler r., evans m., showers w., hoffmann s., lottibond r., hajdas i., bonani g. (2001) persistent solar influence on north atlantic climate during the holocene, science. 294, 2130-2136, doi:10.1126/science.1065680. boussetta s., bassinot f., sabbatini a., caillon n., nouet j., kallel n., rebaubier h., klinkhammer g., labeyrie l. (2011) diagenetic mg‐rich calcite in mediterranean sediments: quantification and impact on foraminiferal mg/ca thermometry. marine geology, 280(1-4), 195-204, doi:10.1016/ j.margeo.2010.12.011. boyle e. a., keigwin l. d. (1985) comparison of atlantic and pacific paleochemical records for the last 250,000 years: changes in deep ocean circulation and chemical inventories. earth and planetary science letters, 76, 135-150. cacho i., grimalt j. o., canals m., sbaffi l., shackleton n. j., schönfeld j., zahn r. (2001) variability of the western mediterranean sea surface temperatures during the last 25,000 years and its connection with the northern hemisphere climatic changes. paleoceanography, 16, 40-52, doi:10.1029/ 2000pa000502. capotondi l., borsetti a. m., morigi c. (1999) foraminiferal ecozones, a high resolution proxy for the late quaternary biochronology in the central mediterranean sea. marine geology, 153, 253-274. capotondi l., vigliotti l. (1999) 40. magnetic and microfaunistical characterization of late quaternary sediments in the western mediterranean (odp leg 161). inference on sapropel formation and paleoceanographic evolution. in: zahn, r., comas, m.c., and klaus, a. (eds.) proceedings of the ocean drilling program, scientific results, college station tx, 161: 505-518. cita m.b., vergnaud-grazzini c., robert c., chamley h., ciaranfi n., d’onofrio s. (1977) paleoclimatic record of a long deep sea core from the eastern mediterranean. quaternary research, 8, 205-235. colleoni f., masina s., negri a., marzocchi a., (2012) plio-pleistocene high-low latitude climate interplay: a mediterranean point of view. earth and planetary science letters, 319-320, 35-44. dekens p. s., lea d.w., pak d. k., spero h. j. (2002) core top calibration of mg/ca in tropical foraminifera: refining paleotemperature estimation. geochemistry geophysics geosystems, 3(4), 1022, doi:10.1029/2001gc000200. de rijk s., hayes a., rohling e. j. (1999) eastern mediterranean sapropel s1 interruption: an expression of the onset of climatic deterioration around 7 ka bp. marine geology, 153, 337-343, doi:10.1016/s0025-3227(98)00075-9. deuser w.g. (1987) seasonal variations in isotopic composition and deep-water fluxes of the tests of perennially abundant planktonic foraminifera of the sargasso sea: results from sediment-trap collections and their paleoceanographic significance. journal of foraminiferal research, 17, 14-27. elderfield h., ganssen g. (2000) past temperature and δ18o of surface ocean waters inferred from foraminiferal mg/ca ratios. nature, 405(6785), 442-445. emeis k.-c., struck u., schulz h.-m, bernasconi s., sakamoto t., martinez-ruiz f. (2000) temperature and salinity of mediterranean sea surface waters over the last 16,000 years: constraints on the physical environment of s1 sapropel formation based on stable oxygen isotopes and alkenone unsaturation ratios. palaeogeography, palaeoclimatology, palaeoecology, 158, 259-280. fairbanks r.g., sverdlove m., free r., wiebe p.h., bé a.w.h. (1982) vertical distribution and isotopic fractionation of living planktonic foraminifera from the panama basin. nature 298, 841-844. ferguson j., henderson g., kucera m., rickaby r. (2008) systematic change of foraminiferal mg/ca ratios across a strong salinity gradient. earth and planetary science letters, 265, 153-166, doi:10. 1016/j.epsl.2007.10.011. field d.b. (2004) variability in vertical distributions of planktonic foraminifera in the california current: relationships to vertical ocean structure. paleoceanography, 19, pa2014. doi:10.1029/2003 pa00970. frigola j., moreno a., cacho i., canals m., sierro f. j., flores j.-a., grimalt j. o., hodell d. a., curtis j. h. (2007) holocene climate variability in the westernmediterranean region from a deepwater sediment record. paleoceanography, 22, pa2209, doi:10.1029/2006pa001307. gačić m., borzelli g. l. e., civitarese g., cardin v., yari s. (2010) can internal processes sustain reversals of the ocean upper circulation? the ionian sea example, geophysical research letters, 37, l09608, doi:10.1029/2010gl043216. gonzalez-mora b., sierro f. j., schönfeld j. (2008) temperature and stable isotope variations in different water masses from the alboran sea (western mediterranean) between 250 and 150 ka. geochemistry geophysics geosystems, 9(10). doi:10.1029/2007gc001906. grauel a.l., bernasconi s.m. (2010) core-top calibration of δ13c and δ18o of g. ruber (white) and u. mediterranea along the southern adriatic coast of italy. marine micropaleontology, 77, 175-186. gupta a. k., anderson d. m., overpeck j. t. (2003) abrupt changes in the asian southwest monsoon the sapropel s1 in the ionian sea 13 during the holocene and their links to the north atlantic ocean. nature, 421, 4-7. hastings d.w., russell a.d., emerson s.r. (1998) foraminiferal magnesium in globeriginoides sacculifer as a paleotemperature proxy. paleoceanography, 13(2), 161-169. hemleben c., spindler m., anderson o.r. (1989) modern planktonic foraminifera. springer-verlag, new york. hernàndez-almeida i., barcena m. a., sierro f.j., flores j.a., calafat a. (2005) influence of 1997-98 el niño event on the planktonic communities from the alboran sea (western mediterranean). geogaceta, 38, 183-186. hoogakker b. a. a., klinkhammer g. p., elderfield h., rohling e. j., hayward c. (2009) mg/ca paleothermometry in high salinity environments. earth and planetary science letters, 284, 583-589, doi:10.1016/j.epsl.2009.05.027. incarbona a., di stefano e., patti b., pelosi n., bonomo s., mazzola s., sprovieri r., tranchida g., zgozi s., bonanno a. (2008) holocene millennial-scale productivity variations in the sicily channel (mediterranean sea). paleoceanography, 23(3), 1-18. doi:10.1029/2007pa001581 incarbona a., di stefano e., sprovieri r., bonomo s., pelosi n., sprovieri m. (2010) millennial-scale paleoenvironmental changes in the central mediterranean during the last interglacial: comparison with european and north atlantic records. geobios, 43(1), 111-122. doi:10.1016/j.geobios.2009. 06.008. kallel n., paterne m., duplessy j.c., vergnaud-grazzini c., pujol c., labeyrie l.d., arnold m., fontugne m., pierre c. (1997) enhanced rainfall on mediterranean region during the last sapropel event. oceanologica acta, 20, 697-712. kisakürek b., eisenhauer a., böhm f., garbe‐ schönberg d., erez j. (2008) controls on shell mg/ca and sr/ca in cultured planktonic foraminiferan, globigerinoides ruber (white), earth and planetary science letters, 273, 260-269, doi:10.1016/j.epsl. 2008.06.026. kontakiotis, g., mortyn p. g., antonarakou a.,. martínez‐botí m. a, triantaphyllou m. v. (2011) field‐based validation of a diagenetic effect on g. ruber mg/ca paleothermometry: core top results from the aegean sea (eastern mediterranean). geochemistry geophysics geosystem, 12, q09004, doi:10.1029/2011gc003692. lea d.w., boyle e.a. (1993) determination of carbonate-bound barium in corals and foraminifera by isotope dilution plasma mass spectrometry. chemical geology, 103, 73-84. lea d.w., pak d.k., spero h.j. (2000) climate impact of late quaternary equatorial pacific sea surface temperature variations,.science, 289(5485), 17191724. lea d.w., mashiotta t.a., spero h.j. (1999) controls on magnesium and strontium uptake in planktonic foraminifera determined by live culturing. geochimica et cosmochimica acta, 63(16), 23692379. mayewski p.a., rohling e.e., stager j.c., karlen w., maasch k.a., meeker l.d., meyerson e.a., gasse f., van kreveld s., holmgren k., lee-thorp j., rosqvist g. rack f., staubwasser m., schneider r.r., steig e.j. (2004) holocene climate variability, quaternary research, 62, 243-255, doi: 10.1016/j.yqres.2004.07.001. malanotte-rizzoli p., manca b.b., ribera d’alcalà m., theocharis a., bergamasco a., bregant d., budillon g., civitarese g., georgopoulos d., michelato a., sansone e., scarazzato p., souvermezoglou e. (1997) a synthesis of the ionian sea hydrography, circulation and water mass pathways during poem-phase i. progress in oceanography, 39, 153-204. manca b., burca m., giorgetti a, coatanoan c., garcia m.-j., iona a. (2004) physical and biochemical averaged vertical profiles in the mediterranean regions: an important tool to trace the climatology of water masses and to validate incoming data from operational oceanography. journal of marine systems, 48(1-4), 83-116. doi:10.1016/j.jmarsys.2003. 11.025. mashiotta t.a., lea d.w., spero h.j., (1999) glacialinterglacial changes in subantarctic sea surface temperature and δ18o-water using foraminiferal mg. earth and planetary science letters, 170, 417-432. mathien‐blard e., bassinot f. (2009) salinity bias on the foraminifera mg/ca thermometry: correction procedure and implications for past ocean hydrographic reconstructions, geochemistry geophysics geosystem, 10, q12011, doi:10.1029/2008 gc002353. mulitza s., donner b., fischer g., paul a., pätzold j., rühlemann c., segl m. (2003) the south atlantic oxygen isotope record of planktic foraminifera. in the south atlantic in the late quaternary (eds. g. wefer, s. mulitza, v. ratmeyer). springer, 121-142. napolitano e., oguz t., malanotte-rizzoli p., yilmaz a., sansone e. (2000) simulations of biological production in the rhodes and ionian basins of the eastern mediterranean. journal of marine systems, 24, 277-298. negri, a., capotondi, l., keller, j. (1999) calcareous nannofossils, planktonic foraminifera and oxygen isotopes in the late quaternary sapropels of the ionian sea. marine geology, 157, 89-103. niebler h.s., hubberten h.w., gersonde r. (1999) oxygen isotope values of planktic foraminifera: a tool for the reconstruction of surface water stratification. in: fischer, g., wefer, g. (eds.), use of proxies in paleoceanography: examples from the south atlantic. springer-verlag, berlin, 165-189. ní fhlaithearta s., reichart g.-j., jorissen f. j., fontanier c., rohling e. j., thomson j., de lange g. j. (2010) reconstructing the seafloor environment during sapropel formation using benthic foraminiferal trace metals, stable isotopes, and sediment composition. paleoceanography, 25(4), 1-17. doi: 10.1029/2009pa001869. nürnberg d. (1995) magnesium in tests of neogloboquadrina pachyderma (sinistral) from high northern and southern latitude. journal of foraminiferal research, 25, 350-368. nürnberg d. (2000) taking the temperature of past ocean surface, science, 289, 1698-1699. bergami c. et al. 14 nürnberg, d., bijma, j., hemleben c. (1996) assessing the reliability of magnesium in foraminiferal calcite as a proxy for water mass temperatures. geochimica et cosmochimica acta, 60, 803-814. nürnberg d., müller a., schneider r.r. (2000) paleosea surface temperature calculations in the equatorial east atlantic form mg/ca ratios in planktic foraminifera: a comparison to sea surface temperature estimates form uk 37, oxygen isotopes, and foraminiferal transfert function. paleoceanography, 15, 124-134. olausson e., (1961) studies of deep-sea cores: reports of the swedish deep-sea expedition, 19471948, 8, 323-438. pujol c., vergnaud-grazzini c. (1995) distribution patterns of live planktic foraminifers as related to regional hydrography and productive systems of the mediterranean sea. marine micropaleontology, 25, 187-217. ravelo a.c., fairbanks r.g. (1992) oxygen isotopic composition of multiple species of planktonic foraminifer: recorders of the modern photic zone temperature gradient. paleoceanography, 7, 815-831. rohling e. j., jorissen f. j., de stigter h. c. (1997) 200 year interruption of holocene sapropel formation in the adriatic sea, j. micropalaeontology, 16, 97-108. rohling e.j., sprovieri m., cane t., casford j.s.l., cooke s., bouloubassi i., emeis k.c., schiebel r., rogerson m., hayes a., jorissen f.j., kroon d., (2004) reconstructing past planktic foraminiferal habitats using stable isotope data: a case history for mediterranean sapropel s5. marine micropaleontology, 50, 89-123. rosenthal y., boyle e.a., slowey n.c., (1997) temperature control on the incorporation of magnesium, strontium, fluorine, and cadmium into benthic foraminiferal shells from little bahama bank: prospects for thermocline paleoceanography. geochimica et cosmochimica acta, 61(17), 36333643. rosenthal y., field m.p., sherrell r.m. (1999) precise determination of element-calcium ratios in calcareous samples using sector field inductively coupled plasma mass spectrometry. analytical chemistry, 71, 3248-3253. rosenthal y., lohmann g. p., (2002) accurate estimation of sea surface temperatures using dissolutioncorrected calibrations for mg/ca paleothermometry. paleoceanography, 17(3), 1044, doi:10.1029/ 2001pa000749. rosenthal y., lohmann g.p., lohmann k.c., sherrell r.m., (2000) incorporation and preservation of mg in globigerinoides sacculifer: implications for reconstructing the temperature and 18o/16o of seawater. paleoceanography, 15(1), 135-146. rouis-zargouni i., turon j.-l., londeix l., essallami l., kallel n., sicre m.-a. (2010) environmental and climatic changes in the central mediterranean sea (siculo-tunisian strait) during the last 30 ka based on dinoflagellate cyst and planktonic foraminifera assemblages. palaeogeography, palaeoclimatology, palaeoecology, 285(1-2), 17-29. doi:10.1016/j. palaeo.2009.10.015. russell a. d., hönisch b., spero h. j., lea d. w. (2004) effects of seawater carbonate ion concentration and temperature on shell u, mg, and sr in cultured planktonic foraminifera. geochimica et cosmochimica acta, 68(21), 4347-4361, doi:10.1016/j. gca.2004.03.013. sabbatini a., bassinot f., boussettas., negri a., rebaubier h., dewilde f., nouet j., caillon n., morigi c. (2011) further constraints on the diagenetic influences and salinity effect on globigerinoides ruber (white) mg/ca thermometry: implications in the mediterranean sea. geochemistry geophysics geosystems, 12(10). doi:10.1029/2011gc003675 sangiorgi f., capotondi l., combourieu nebout n., vigliotti l., brinkhuis h., giunta s., lotter a. f., morigi c., negri a., reichart g.-j. (2003) holocene seasonal seasurface temperature variations in the southern adriatic sea inferred from a multiproxy approach. journal of quaternary science, 18(8), 723-732. schmidt g.a., mulitza s. (2002) global calibration of ecological models for planktic foraminifera from coretop carbonate oxygen-18. marine micropaleontology 44, 125-140. shackleton n. j., (1974) attainment of isotopic equilibrium between ocean water and benthonic foraminifera genus uvigerina: isotopic changes in the ocean during the last glacial. in: les méthodes quantitatives d’étude des variations du climat au cours du pleistocène. cent. natl. de la rech. sci., gifsur-yvette, france, 203-209 tedesco k., thunell r.c., astor y., muller-karger f. (2007) the oxygen isotope composition of planktonic foraminifera from the cariaco basin, venezuela: seasonal and interannual variations. marine micropaleontology 62, 180-193. vallefuoco m., lirer f., ferraro l., pelosi n., capotondi l., sprovieri m., incarbona a. (2011) climatic variability and anthropogenic signatures in the gulf of salerno (southern-eastern tyrrhenian sea) during the last half millennium. rendiconti lincei, 23(1), 13-23. doi:10.1007/s12210-011-0154-0 van raden u. j., groeneveld j., raitzsch m., kucera m. (2011) mg/ca in the planktonic foraminifera globorotalia inflata and globigerinoides bulloides from western mediterranean plankton tow and core top samples. marine micropaleontology, 78, 101-112, doi:10.1016/j.marmicro.2010.11.002. vigliotti l., asioli a., bergami c., capotondi l., piva a. (2011) magnetic properties of the youngest sapropel s1 in the ionian and adriatic sea: inference for the timing and mechanism of sapropel formation. italian journal of geoscience (bollettino della società geologica italiana), 130(1), 106-118. ms. received: november 29, 2012 final text received: february 2, 2013 << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /all /binding /left /calgrayprofile (gray gamma 2.2) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /warning /compatibilitylevel 1.4 /compressobjects /tags /compresspages true /convertimagestoindexed true /passthroughjpegimages true /createjobticket false /defaultrenderingintent /default /detectblends true /detectcurves 0.1000 /colorconversionstrategy /leavecolorunchanged /dothumbnails false /embedallfonts true /embedopentype false /parseiccprofilesincomments true /embedjoboptions true 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<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> /ita (utilizzare queste impostazioni per creare documenti adobe pdf adatti per visualizzare e stampare documenti aziendali in modo affidabile. i documenti pdf creati possono essere aperti con acrobat e adobe reader 5.0 e versioni successive.) /enu (use these settings to create adobe pdf documents suitable for reliable viewing and printing of business documents. created pdf documents can be opened with acrobat and adobe reader 5.0 and later.) >> >> setdistillerparams << /hwresolution [1200 1200] /pagesize [396.850 566.929] >> setpagedevice imp.balini gssp definiti in italia stato dell'arte per il triassico marco balini dipartimento di scienze della terra “ardito desio”, università degli studi di milano, via mangiagalli 34, 20133 milano. <marco.balini@unimi.it> abstract: m. balini, the gssp defined in italy. state of the art for the triassic. in the last 10 years the subcommission on triassic stratigraphy increased speed in the definition of the gssp of the triassic standard global chronostratigraphic scale. in 2001 the base of the induan has been defined in china and few years later in 2005 the base of the ladinian has been defined in italy. among the gssp candidate sections which are at the present under discussion there are two sections in italy with a great potential. prati di stuores/stuores wiesen (dolomites) has been finally selected by the task group as the only candidate for the base of the carnian stage and the final ballot is in progress. pizzo mondello (agrigento) is one of the two candidates for the definition of the base of the norian stage and a final decision is expected by 2009. the italian successions exposed in lagonegro and western sicily might also have some potential for the definition of the base of the rhaetian, but more work is necessary to come to a selection of a possible candidate section. parole chiave: trias, gssp, italia. keywords: trias, gssp, italy il quaternario italian journal of quaternary sciences 21(1a), 2008 11-16 la definizione della scala cronostratigrafica del triassico la definizione della scala cronostratigrafica standard globale (standard global chronostratigraphic scale: sgcs) per il sistema triassico è compito della subcommission on triassic stratigraphy (sts, international commission on stratigraphy). la sts, come tutte le altre sottocommissioni della ics, è composta da volontari, che servono in qualità di corresponding members, voting members, task group members, t.g. chairman, ed executives. il task group è un gruppo di lavoro su un problema specifico che viene costituito in modo aperto e gerarchicamente flessibile. all'atto della costituzione di un t.g. l'inserimento è aperto a tutti, anche ai non membri della sts, purchè sia chiaro l'interesse ed il potenziale contributo dei candidati. le relazioni con l'ics sono tenute formalmente dagli executives (chairman, vice-chairman e segretario), il chairman è inoltre di diritto membro votante della ics. la sts nel suo complesso è tenuta a rispettare le scadenze di lavoro imposte dall'ics, e che sono a loro volta legate ai rapporti annuali, ed alle sessioni plenarie dell'iugs. il mandato principale che hanno tutte le subcommission, tranne la issc, è quello di provvedere a proporre i gssp (global stratotype section and point) per le unità cronostratigrafiche di ordine pari o superiore al piano della standard global chronostratigraphic scale non ancora formalmente definite secondo i canoni della international stratigraphic guide (salvador, 1994). task groups attivi nella sts il sistema triassico è suddiviso in 7 piani, ma solo l'induano ed il ladinico sono definiti con un gssp ratificato. l'induano è definito sulla base della comparsa del conodonte hindeodus parvus nello strato 27c della sezione di meishan d (cina: yin et al., 2001). il ladinico è definito in italia, nella sezione di bagolino b, sulla base della comparsa dell'ammonoide eoprotrachyceras curionii (brack et al., 2005). i cinque piani per i quali non è ancora stato definito il gssp rappresentano un problema piuttosto grosso per la sgcs del triassico, su cui la subcommission investe gran parte della sua attività. sono attivi nella sts 5 task group, ognuno dei quali è incaricato di analizzare le migliori successioni in cui è documentato l'intervallo del limite di un piano specifico. i t.g. attivi sono i seguenti: induano/olenekiano, olenekiano/ anisico, ladinico/carnico, carnico/norico, norico/ retico. a questi t.g. si affianca un gruppo di lavoro dedicato alle suddivisioni del triassico non marino. infine alcuni membri della sts partecipano all'enorme gruppo di lavoro sul limite triassico/giurassico (più di cento membri), ma la gestione di questo grossissimo problema (7 sezioni potenzialmente candidate) spetta alla subcommission on jurassic stratigraphy. sezioni stratigrafiche ed eventi marker in discussione per le facies marine del triassico la biocrono12 m. balini stratigrafia a più alta risoluzione è basata sugli ammonoidi ed i conodonti, per cui è tra questi due gruppi che solitamente vengono ricercati gli eventi marker dei gssp. le specie di ammonoidi offrono in assoluto il maggiore potere di risoluzione, con specie che spesso hanno un range inferiore o uguale alla durata di una subzona, mentre le specie di conodonti hanno una distribuzione un pò più lunga, in generale superiore alla durata di una zona. i conodonti peraltro sono più frequenti degli ammonoidi nelle successioni sedimentarie, per cui spesso si definiscono gssp usando bioeventi a conodonti in quanto questi sono più uno strumento piu' pratico. le attività dei task group sono complesse, ed i processi di verifica e discussione delle successioni migliori richiedono molto tempo, variabile da 10 a 20 anni. le motivazioni sono numerose e varie, quali la scarsità di specialisti in tanti settori soprattutto paleontologici e biostratigrafici, la difficoltà di comporre gruppi di lavoro multidisciplinari, la scarsità dei finanziamenti. a queste si devono talvolta aggiungere (purtroppo) personalismi e nazionalismi. il fattore principale che condiziona i tempi delle approvazioni dei gssp, è rappresentato dal fatto che la sezione stratigrafica perfetta, che rispetti tutti i requisiti segnalati da salvador (1994), non esiste, perciò si devono analizzare sezioni “imperfette”, la cui valutazione presenta margini di divergenze. lo stato attuale delle discussioni nei vari task group della sts è illustrato in fig. 1. al momento tre task group sono arrivati al la votazione finale: induano/olenekiano, ladinico/carnico e olenekiano/ anisico. per gli altri t.g. il momento della votazione è prossimo, ma non imminente. vediamo anzitutto lo stato dell'arte per quei limiti che vengono o verranno definiti all'estero (olenekiano ed anisico) e poi esamineremo con maggior dettaglio le possibilità di gssp in italia. il dibattito sul limite induano/olenekiano da tre anni si è focalizzato su due sezioni stratigrafiche: mud nell'himalaya dell'india e chaohu in cina. il t.g. ha raggiunto ormai accordo sul marker event della base dell'olenekiano, che è la comparsa del conodonte neospathodus waageni, però esiste profonda discordia su quale delle due sezioni sia la migliore, tanto che si hanno due proposte di gssp contrapposte. attualmente (ottobre-novembre 2007) è in corso la seconda votazione da parte del t.g., necessaria dato che nella prima votazione nessuna delle due proposte ha raggiunto la maggioranza del 60% di consensi. il t.g. olenekiano/anisico si trova in una altro tipo di difficoltà, pur essendo attesa una votazione per la fine di quest'anno (2007). il t.g. ha individuato già nel 1999 la più completa sezione stratigrafica a desli çaira in romania. questa sezione è stata studiata da un team internazionale, che ha acquisito i dati relativi a conodonti, foraminiferi, magnetostratigrafia e variazione degli isotopi stabili. il t.g. ha già dibattuto sulla scelta del marker event, votando in favore della comparsa del conodonte neogondolella timorensis. con queste premesse ci si aspetterebbe una soluzione facile e rapida dei lavori, invece la definizione del gssp è bloccata da anni sulla difficoltà di conclusione dello studio degli ammonoidi, che rappresentano il gruppo chiave per calibrare l'isocronia della comparsa di n. timorensis. prospettive per gssp definiti in italia le successioni sedimentarie italiane hanno un grande significato per la formalizzazione del triassico superiore, che almeno in buona parte ha ottime possibilità di venire definito con gssp in italia. gssp del carnico la definizione della base del carnico, e quindi della serie triassico superiore, è alla fine della procedura di formalizzazione. il t.g. ladinico/carnico dopo circa 9 anni di lavoro è giunto alla conclusione della sua attività, ed è in corso la votazione finale (novembredicembre 2007) da parte dei membri. la votazione riguarda una sola proposta, ovvero il fad dell'ammonoide daxatina nel livello sw4 della sezione di prati di stuores/stuores wiesen (dolomiti, italia; fig. 2) (mietto et al., in press), per cui si può dire con ragionevole tranquillità, che il carnico verrà definito in italia. la proposta in votazione è sostanzialmente uguale a quella presentata nel 1999 (broglio loriga et al., 1999), ma questa continuità non vuol dire che il t.g. abbia svolto poca attività. al contrario nei 9 anni di lavoro, la necessità di verificare la correlabilità tra le sezioni migliori al mondo, ha costituito uno stimolo fondamentale per l'approfondimento della bioe cronostratigrafia integrata dell'intervallo del limite. le tre sezioni migliori al mondo (prati di stuores, dolomiti; spiti, himalaya e south canyon, nevada, usa) sono state studiate da team interdisciplinari, ed i risultati sezioni significative/candidate marker event decisione retico steinbergkogel (austria) conodonti (2 opzioni) 2009 superiore norico pizzo mondello (it.), black bear ridge (can.) conodonti (4 opzioni) 2008 carnico prati di stuores (italia) fad daxatina 2007 medio ladinico bagolino (italia) fad e. curionii 2005 anisico desli caira (ro.), west pingdinshan (cina) fad ng. timorensis 2007 inferiore olenekiano chaohu (cina), mud (india) fad ns. waageni 2007 induano meishan (cina) fad h. parvus 2001 fig. 1 stato dell'arte della definizione della scala cronostratigrafica standard del triassico. a parte i piani induano e ladinico, definiti con gssp, tutti gli altri piani del triassico sono ancora in via di definizione. state of the art in the definition of the standard chronostratigraphic scale of the triassic. only the induan and ladinian stages are provided by a gssp, while the gssp of the other stages are still in progress. t r ia s s ic o hanno incluso anche la revisione della scala cronostratigrafca nordamericana. le sezioni analizzate erano in una certa misura complementari e non alternative, come spesso capita nell'analisi di candidati gssp. prati di stuores ha un buon record ad ammonoidi, cui si aggiungono gruppi minori, ed un segnale paleomagnetico primario. elementi negativi sono l'influenza paleoambientale sul record a conodonti che probabilmente spiega l'assenza di daonelle ed halobie. spiti ha un ricco record a bivalvi pelagici ed a conodonti, ma presenta una documentazione ad ammonoidi piuttosto limitata, inoltre è rimagnetizzata. in ultimo south canyon presenta sicuramente la migliore documentazione ad ammonoidi e un buon record a bivalvi pelagici, cui si accompagnano purtroppo un'esposizione scadente ed un record a conodonti limitato a una parte della successione, peraltro rimagnetizzata. i punti principali che sono stati approfonditi negli ultimi anni sono la posizione stratigrafica relativa degli ammonoidi frankites, daxatina e trachyceras, che nel 1999 non sembrava corrispondere tra il nord america e le sezioni tetidiane di prati di stuores e spiti, e la posizione del fad del conodonte paragondolella polygnathiformis, che per lungo tempo è stato un possibile candidato marker per la base del carnico, ma che sembrava avere posizioni molto diverse nelle diverse aree paleogeografiche. la scelta finale è stata indirettamente influenzata dagli specialisti di conodonti, che hanno abbandonato il sostegno del fad di p. polygnathiformis come possibile marker event della base del carnico, per cui questo evento è stato ridimensionato ad proxy del limite, insieme alla comparsa di halobiidae primitive. nel complesso la definizione del gssp del carnico rappresenta un successo per l'italia e per la ricerca ital iana. le attività svolte dal t.g. ladinico/carnico hanno visto sempre i ricercatori italiani in primo piano. la direzione del t.g. è stata effettuata da m. gaetani (milano), con la collaborazione dello scrivente nel corso dell'ultimo anno. le sezioni stratigrafiche analizzate dal t.g. sono tre (prati di stuores, spiti e south canyon) e sono state studiate tutte da team condotti da italiani. le fondamentali ricerche a prati di stuores sono state coordinate prima da c. broglio loriga (ferrara), poi da p. mietto (padova), ed hanno visto come protagonisti numerosi ricercatori di padova, ferrara, perugia modena e milano. lo scrivente ha coordinato le ricerche sia in in spiti (himalaya, india) con a nicora (milano) e specialisti austriaci ed indiani, che a south canyon (nevada, usa), in collaborazione con specialisti americani e canadesi. gssp del norico al momento attuale (autunno 2007), i l t.g. carnico/norico è arrivato a selezionare due successioni di per la definizione del gssp del norico: black bear ridge in british columbia (canada) e pizzo mondello nella sicilia occidentale (agrigento). 13gssp definiti in italia. stato dell’arte... la sezione di black bear ridge (orchard et al. 2001) è esposta lungo la riva del bacino artificiale del lago williston, nella parte nord occidentale della british columbia. la sezione è stata studiata da un gruppo molto ben organizzato di specialisti canadesi ed americani, in gran parte facenti capo al geological survey of canada. la successione ha un record a conodonti molto ricco ed una documentazione a bivalvi molto buona. gli ammonoidi sono abbastanza rari e non ben conservati, tuttavia permettono di riconoscere le ultime due cronozone del carnico e la prima del norico. elementi aggiuntivi sono i brachiopodi, e forse le variazioni degli isotopi stabili, mentre non ci sono dati di radiolari, e la magnetostratigrafia non è applicabile in quanto la successione è rimagnetizzata. la sezione di pizzo mondello (monti sicani, sicilia occidentale) presenta numerosi elementi di grande interesse. anzitutto la successione affiorante in questo sito sono i calcari con selce (equivalente alla formazione di scillato), che raggiungono uno spessore di circa 400m. la sezione è molto bene affiorante (fig. 3), essendo sviluppata in una cava attiva negli anni '70, e l'esposizione consente di seguire lateralmente gli strati anche per 100-200 metri. la facies è pelagica-emipelagica, con una costanza e regolarità veramente inusuale per un intervallo di tempo così lungo (carnico superiore-retico basale). la sezione è stata presentata a livello internazionale a metà degli anni '90 (bellanca et al., 1995, gullo, 1996; muttoni et al., 2001; 2004), ed è diventata un riferimento importantissimo per il record magnetostratigrafico e le variazioni del δ18o e δ13c, tuttavia presenta anche delle grossissime potenzialità biocronostratigrafiche (fig. 4). i calcari con selce del bacino sicano, sono noti dal xix secolo (gemmellaro, 1882 e 1904) per il ricco contenuto in ammonoidi e halobie, inoltre la facies è molto interessante per i radiolari. per valorizzare queste grosse potenzialità biocronostratigrafiche ed arrivare ad un proposta formale di gssp per pizzo mondello, si è recentemente costituito un ampio gruppo di lavoro composto da specialisti italiani (università di milano, ferrara, padova, palermo e fig. 2 la sezione di prati di stuores/stuores wiesen. the prati di stuores/stuores wiesen section. perugia) e stranieri (mit e cortland, usa; lausanne, svizzera). i primi dati disponibili sono stati presentati al congresso “the global triassic” di albuquerque (guaiumi et al., 2007) e sono in stampa (nicora et al., in press). i nuovi risultati hanno riscosso un notevole interesse tanto che il t.g. carnico/norico ha dilazionato la votazione sul candidato gssp al 2008, per poter tener conto degli studi in corso a pizzo mondello. nel corso del 2008 il team multidisciplinare che lavora a pizzo mondello programma di selezionare un bioevento a conodonti da presentare come candidato gssp, con il sostegno di biocronostratigrafia ad ammonoidi, halobiidae, radiolari, dinoflagellate, magnetostratigrafia, ciclostratigrafia, variazioni degli isotopi stabili e, probabilmente, datazioni radioisotopiche di tufiti. le speranze di una selezione in italia sono quindi ben fondate. gssp del retico il retico pressoché da sempre è il piano del triassico più difficile e discusso. in italia le successioni norico-retiche sono potenti e diffuse, ed è possibile che il nostro paese possa fornire spunti importanti anche per la soluzione del problema del limite norico/retico. al momento attuale il dibattito sulla definizione della base del retico è poco sviluppato, tuttavia nel 2007 è stata delineata una proposta di gssp (krystyn et al., 2007), sulla sezione di steinberkogel in alpi settentrionali (austria). questa sezione, ubicata nella regione storicamente importante di hallstatt, è molto interessante per la presenza di ammonoidi, conodonti e bivalvi, per la buona qualità del segnale paleomagnetico e le variazioni degli isotopi stabili, però è spessa solo 4 metri e quindi molto probabilmente condensata. il marker event non è ancora stato selezionato ma secondo krystyn va individuato con i conodonti. il team multidisciplinare che lavora a pizzo mondello sul limite carnico/norico sta valutando anche la possibilità di presentare una proposta di gssp per il retico. le sezioni/aree che si stanno esaminando sono pizzo mondello, lagonegro e le alpi orientali. in queste successioni, come a steinberkogel, si lavora principalmente sui conodonti. le sezioni in studio sembrano essere purtroppo un po' carenti per quanto riguarda ammonoidi e bivalvi pelagici, ma ci sono ottime potenzialità per quanto riguarda magnetostratigrafia e variazioni degli isotopi stabili. le indagini programmate per il 2008 sarenno determinanti per chiarire se esistono realmente elementi per una proposta di gssp in italia anche per il retico. bibliografia bellanca a., di stefano p. & neri r. (1995) sedimentology and isotope geochemistry of carnian deep-water marl/limestone deposits from the sicani mountains, sicily: environmental implications and evidence for planktonic source of lime mud. palaeogeography, palaeoclimatology, palaeoecology, 114, 111-129. brack p., rieber, h., nicora a. & mundil r. (2005) the global boundary stratotype section and point (gssp) of the ladinian stage (middle triassic) at bagolino (southern alps, northern italy) and its implication for the triassic time scale. episodes, 28, 233-244. broglio loriga c., cirilli s., de zanche v., di bari d., gianolla p., laghi g.f., lowrie w., manfrin s., mastandrea a., mietto p., muttoni g., neri c., posenato r., reichichi m., rettori r. & 14 fig. 3 i “calcari con selce” affioranti a pizzo mondello in località la cava. la sezione è misurata in due segmenti (a e b) perfettamente correlati lungo strato. l'intervallo critico per la definizione del limite carnico/norico corrisponde alla parte media del segmento b. the “calcari con selce” exposed at pizzo mondello (la cava site). the section is composed of two segments (a and b) overlapping in part and very well correlated following bed along strike. the carnian/norian boundary interval is recorded in the middle part of segment b. m. balini 15 -90 900 vgp lat it ude (°) 0 2 4 δ13c (per mil)δ18o (per mil) -4 -2 0 2 pm1 pm2 pm3 pm4n pm5n pm6 pm7 pm8 pm9 pm10 pm11 pm12 pizzo mondello (mut t oni et al., 2004) magnet ic polarit y pm4r pm5r in t e r v a l o f in t e r e s t in t h is p a p e r fig. 4 la sezione di pizzo mondello con magnetostratigrafia e variazioni degli isotopi stabili (da nicora et al., in press, modificato da muttoni et al. 2004). the pizzo mondello section showing magnetostratigraphy and variation of the stable isotopes (from nicora et al., in press, partly modified from muttoni et al. 2004). gssp definiti in italia. stato dell’arte... roghi g. (1999) the prati di suores/stuores wiesen section (dolomites, italy): a candidate global stratotype section and point for the base of the carnian stage. riv. it. paleont. strat., 105, 37-78. gemmellaro g.g. (1882) sul trias della regione occidentale della sicilia. mem. acc. lincei, s. 3, 12, 451-473. gemmellaro g.g. (1904) i cefalopodi del trias superiore della regione occidentale della sicilia. giornale di scienze naturali ed economiche, 24, 1-319. guaiumi c., nicora a., preto n., rigo m., balini m., di stefano p., gullo m., levera m., mazza m. & muttoni g. (2007) new biostratigraphic data around the carnian/norian boundary from the pizzo mondello section, sicani mountains, sicily. new mexico museum of natural history and science bulletin, 41, 40-42. gullo m. (1996) conodont biostratigraphy of uppermost triassic deep-water calcilutites from pizzo mondello (sicani mountains): evidence for rhaetian pelagites in sicily. palaeogeography, palaeoclimatology, palaeoecology, 126, 309-323. krystyn l., bouquerel h., kuerschner w., richoz s. & gallet y. (2007) proposal for a candidate gssp for the base of the rhaetian stage. new mexico museum of natural history and science bulletin, 41, 189-200. mietto p., andreetta r., broglio loriga c., buratti n., cirilli s., de zanche v., furin s., gianolla p., manfrin s., muttoni g., neri c., nicora a., posenato r., preto n., rigo m., roghi g. & spötl c. (in press) a candidate of the global boundary stratotype section and point for the base of the carnian stage (upper triassic). gssp at the base of the canadensis subzone (fad of daxatina) in the prati di stuores/stuores wiesen section (southern alps, ne italy). albertiana, 36. muttoni g., kent d.v., di stefano p., gullo m., nicora a., tait j. & lowrie w. (2001) magnetostratigraphy and biostratigraphy of the carnian/norian boundary interval from the pizzo mondello section (sicani mountains, sicily). palaeogeography, palaeoclimatology, palaeoecology, 166, 383-399. muttoni g., kent d.v., olsen p.e., di stefano p., lowrie w., bernasconi s.m. & hernandez f.m. (2004) thetyan magnetostratigraphy from pizzo mondello (sicily) and correlation to the late triassic newark astrochronological polarity time scale. gsa bulletin, 116, 1034-1058. nicora a., balini m., bellanca a., bertinelli a., bowring s.a., di stefano p., dumitrica p. , guaiumi c., gullo m., hungerbuehler a., levera m., mazza m., mcroberts c.a., muttoni g., preto n., & rigo m. (in press) the carnian/norian boundary interval at pizzo mondello (sicani mountains, sicily) and its bearing for the definition of the gssp of the norian stage. albertiana, 36. orchard m.j., zonneveld j.p., johns m.j., mcroberts c.a., sandy m.r., tozer e.t. & carrelli g.g. (2001) fossil succession and sequence stratigraphy of the upper triassic of black bear ridge, northeast british columbia, a gssp prospect for the carnian-norian boundary. albertiana, 25, 10-22. yin h., zhang k., tong j., jang z.& wu s. (2001) the global stratotype section and point (gssp) of the permian-triassic boundary. episodes, 24, 102-114. salvador a. (ed.) (1994) international stratigraphic guide. second edition. v. di 214 pp. geol. soc. of america. ms. ricevuto il 2 aprile 2008 testo definitivo ricevuto il 17 aprile 2008 ms. received: april 2, 2008 final text received: april 17, 2008 16 m. balini microsoft word 00_indice_bm03 available online http:/amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 25 (1), 2012, 67-74 an approach to body size fluctuations in quaternary continental mammals: the case of hippopotamuses from western europe paul p.a. mazza & adele bertini dipartimento di scienze della terra, dst, università degli studi di firenze, italy corresponding author: p.p.a. mazza <paul.mazza@unifi.it> abstract: several paleoenvironmental analyses show that community change over geological time is driven by ecological factors which, in turn, are regulated by climate. to most effectively examine the origin of community change researchers need to single out and track specific paleobiological properties and to see how much they depend on local or more general constraints. a suite of proxies have been used to analyze ecologically based community change. body size is one of the most sensitive to ecological factors and is therefore deemed to disclose significant information on past environmental conditions. bergmann’s rule proposes a thermoregulatory explanation to the latitudinal gradient of increasing animal body size. whereas some animals fit the predictions of bergmann's rule, others do not, or even correlate negatively. several critical reviews cast doubts on the “thermal” interpretation of bergmann’s rule, and proposed alternative hypotheses for geographic variation in body size based on various physiological, biological and ecological constraints. the ice age cycling that was set off by the 2.6 ma arctic ice cap expansion led gradually to ever increasing environmental patchiness, and the effects of this habitat fragmentation became particularly evident in the late pleistocene and holocene. megafaunas progressively split up into metapopulations confined into ever smaller and more isolated habitats. this led numerous large mammals to experience endemic evolution in isolation, and body sizes changed in ways similar to those observed in land mammals distributed on true islands. keywords: body size, bergman’s rule, mammals, climate change, quaternary. 1. introduction the processes that cause community change over geological time have been one of the most investigated topics in paleoecology. to most effectively examine these processes researchers need to single out and track paleobiological properties unaffected by local constraints. body size is most sensitive to ecological factors and can disclose significant information on past environmental conditions. the pattern and extent of body size change in quaternary land mammals has often been connected to climatic change (tchernov, 1968; davis, 1977, 1981; klein, 1986). quaternary is actually characterized by particularly unstable conditions, with long-term cooling trends and glacial cycles of ever increasing amplitude. there are two major, relatively abrupt climate transitions: one just before its onset, around 2.7 myr ago, of a major northern hemisphere glaciation, the other is the so-called “mid-pleistocene revolution” (mpr; berger & jansen, 1994) when the dominant periodicity of glacial response switched from 41 to 100 kyr. an equivalence can be established between the body size change of a specific taxon within a community over geological time, on the one hand, and the change of a phenotypic trait of an organism over geological time, on the other. as phenotypic changes reveal specific adaptations, so can body size changes provide information on the environmental modifications that caused them. bergmann’s rule, pros and contras many studies have highlighted the coincidence of climate or latitude change with size changes in various mammals. bergmann (1847) observed a latitudinal increase in animal body size and proposed a thermoregulatory explanation to the phenomenon. climate/latitudeinduced size change is often connected to peculiar allometric responses. in 1877 joel a. allen gave the fundamentals of what was from then on known as allen’s rule observing that land mammals from colder climates usually develop shorter limbs than their counterparts from warmer climates. subsequently re-examined and reformulated, the so-called bergmann’s rule (or mechanism sensu meiri, 2011) was found to apply also to poikilotherm vertebrates, as well as to a number of invertebrate taxa (e.g., ashton, 2002; makarieva et al., 2005, and references therein), which however are not subject to the heat-conservation mechanisms underlying bergmann’s rule. mclean (1991) believes that large mammals store more heat than smaller mammals, but cannot release it as much easily owing to their relatively small surface/volume ratios. the rapid warming at the transition to an interglacial/interstadial phase causes greater embryogenesis dysfunction in larger mammals than in smaller ones (mclean, 1991). in these periods large mammals may therefore either disappear, experience dwarfing if they are given sufficient time to adapt to the new conditions, or otherwise reduce in size before becoming extinct (kurtén, 1972; guthrie, 1984). meiri & dayan (2003) reviewed the occurrence of bergmann’s rule in statistical samples of birds and mammals, observing that over 72% of the birds and 65% of the mammals they examined conform to it. meiri et al. (2007) revised these results finding that the mean variation explained by latitude is 35% for birds and 37% for mazza p.p.a., bertini a. 68 mammals. meiri & dayan (2003) had also found that birds tend to adhere to bergmann’s rule whatever their size, while smaller mammals (<500 g) conform significantly less than larger ones. the latter observation is consistent with the conclusions drawn by mcdonald (1984), martin (1984), merilees (1984), and ashton et al. (2000), who found that large land mammals had been more sensitive to the climatic oscillations than smaller ones. meiri et al. (2004) obtained a significantly positive correlation between skull length and latitude in 50% of 44 carnivore species they examined, and a significantly negative correlation in 11% of those species. diniz-filho fig. 1 curve through estimated average weights of western european hippopotamuses, obtained from odontometric and osteometric data, as well as by using allometric scaling techniques (analysis in progress by the writers). stratigraphic scheme modified from bertini et al. (2010). body size fluctuations in quaternary hippopotamuses 69 et al. (2007) have also analyzed patterns of body size geographic variation in european carnivores. rodríguez et al. (2006) observed nonlinear relationships between body size and temperature, finding a strong association in northern europe, and virtually none in the south. kurtén (1968) and huston & wolverton (2011) propose the idea that mammal size is primarily connected with the amount and nature of food resources. barnosky (2005) actually showed that most body-size reductions at the last glacial/interglacial transition were ecophenotypic rather than genotypic changes. teplitsky et al. (2008) reached similar conclusions. in the light of these results, many authors have cast doubt on the “thermal” interpretation of bergmann’s rule, finding that body size is controlled by many other factors rather than just temperature. some authors advocate various physiological, biological and ecological constraints [(1) vascular control and fur insulation (scholander 1955; steudel et al., 1994); (2) food availability (huston & wolverton, 2011); (3) basal metabolic rate (steudel et al., 1994); (4) energy costs (thompson, 1942); (5) size and nature of food (teplitsky et al., 2008); (6) dominance in a community (hansson & jaarola, 1989); (7) competition (simberloff & boecklen, 1981); (8) mating success (lande & arnold, 1983)]. others suggest additional climatic factors, such as moisture levels, demonstrating that small body size is associated with hot and humid conditions while larger size is connected to cooler and drier circumstances (rosenzweig, 1968; james, 1970). yom-tov & nix (1986) and yom-tov & geffen (2006) observed that body size correlates with moisture and precipitation, and thus with primary production, better than with temperature. blois & hadly (2009) linked body sizes to climatechange-related responses of vegetation and primary productivity. during the last decade, a wealth of studies analyzed the empirical validity of ecogeographic rules (blackburn & gaston, 1998; blackburn et al., 1999; angilletta & dunham, 2003; cruz et al., 2005; millien et species and specimens ortona colle lepre valdarno colle curti untermaßfeld h. gr. h. antiquus (= h. tiberinus) incarcal i h. amphibius (barrington included) upper m2 (janis, 1990) length x breadth (cm) 28.75 30.66 log 1.46 1.48 min length x breadth (cm) 22.56 25.3 23.04 18.49 log 1.35 1.4 1.36 1.26 max length x breadth (cm) 30.24 30.36 34.16 32.48 lower m2 (janis, 1990) length (cm) 5,48 log 0.74 6.32 min length (cm) 5 6.6 5.2 0.8 log 0.7 0.82 0.71 max length (cm) 6.4 7 5.9 log 0.8 0.84 0.77 femur (allometric scaling: schmidtnielsen, 1984; reitz and quitmyer, 1988; prange et al., 1979) dc (cm) 9.5 11.7 log 0.98 1.07 dc min (cm) 9.5 9.5 8.7 7.4 log 0.98 0.98 0.94 0.87 dc max (cm) 10.8 10.2 9.3 8.6 log 1.03 1.01 0.97 0.93 fifth metatarsal (allometric scaling: schmidt-nielsen, 1984; reitz and quitmyer, 1988; prange et al., 1979) length (cm) 9.92 9.3 log 0.99 0.97 min length (cm) 9.5 10 9.9 10.3 log 0.98 1.00 0.99 1.01 max length (cm) 11 10.7 10.8 10.9 log 1.04 1.03 1.03 1.04 estimated weights (kg) 10002100 2200 2100-2750 21002600 2200-3200 1700-2750 2000 1260-3000 tab. 1 body weight estimates mazza p.p.a., bertini a. 70 al., 2006; rodríguez et al., 2006, 2007; gaston et al., 2007; meiri & gavin, 2007; meiri et al., 2007; aragón et al., 2010; gardner et al., 2011). many of these factors suggested as alternatives to bergmann’s rule could be more or less directly correlated, or at least influenced, by the environmental and climatic changes that occurred over the last 2 million years. quaternary climate instability caused changes in the vegetation (e.g., lang, 1994; bertini, 2003, 2010; tzedakis, 2003, 2007; gonzález-sampériz et al., 2010; rodriguez-sanchez et al., 2010; joannin et al., 2011; magri & palombo, 2012), as well as the progressive fragmentation of the ecosystems, with consequences on the fauna that are described further on. 2. body size change in quaternary hippopotamuses: a western european example in western europe, the significant changes in temperature and precipitation ensuing from the maximum expansion of the arctic ice cap that set off the ice age cycling caused the progressive demise of tropical and subtropical forest taxa, while altitudinal arboreal taxa and herbs spread, with the creation of new competition patterns (e.g., suc et al., 1995; bertini, 2010, bertini et al., 2010; fig. 1). vegetational modifications clearly reflect substantial paleoecological and paleoclimatic reorganizations. most commonly, but not exclusively (e.g., bertini, 2010), artemisia and ephedra-dominated open vegetation alternated with interglacial forests characterized by deciduous taxa, such as quercus, carya, carpinus, pterocarya, ulmus and zelkova in response to the early pleistocene 41 kyr climatic cycling. a ca. 100 kyr (eccentricity) cycling, which started since the transition to the middle pleistocene, intensified the glacial phenomena, but also seasonality and aridity. this had disrupting consequences on both flora and fauna. many resident animal taxa became extinct, whereas others were replaced by new incomers from eastern europe, central asia, and africa. some of the western european inhabitants seem to have changed size in coincidence with climatic variations. hippopotamuses might represent a good example (fig.1). if the body sizes of european quaternary hippopotamus are estimated from stratigraphically controlled remains, it seems that these pachyderms grew smaller from the jaramillo subchron onwards (table 1). during the second half of the middle pleistocene these suiforms turned progressively rarer, especially during the coldest phases of this interval (mis 8, 6). at the beginning of the late pleistocene, during the very warm mis 5e, large to very large hippopotamuses dispersed as far north as the british isles. it is worth noting that western european hippopotamuses grew smaller in coincidence with the mpr (~1.2÷0.5 ma) and just after the disappearance of the subtropical vegetal ecosystems from the mediterranean area, around 1.2 ma (e.g. combourieu-nebout & vergnaud-grazzini, 1991; bertini, 2010). the great modifications in the structure and composition of vegetal formations induced by the long lasting glacial phases (up to 85 ka) and short interglacial phases (up to 15 ka) of this time period had significant consequences on the type and availability of food for the fauna. in a working hypothesis in preparation by the writers, hippopotamuses turned smaller under the prevalently cooler middle pleistocene conditions, in contrast to bergmann’s predicted pattern, as an indirect response to climatic change, owing to the unsteadiness in food availability. this would fully agree with kurtén’s (1968) and huston & wolverton’s (2011) idea that mammal size is primarily connected with the amount and nature of food resources. 3. the “insularization” of quaternary continental mammals the mpr caused increasing habitat fragmentation (simakova, 2001; markova et al., 2001; zazula et al., 2003), whose effects became particularly evident in the late pleistocene and holocene. the mosaic evolution of plant communities, as habitats grew smaller and more isolated, turning into habitat islands (lister & bahn, 1994; ward, 1997; reumer, 2007), affected the evolutionnary relationships between herbivores and the vegetation (graham & lundelius, 1984). megafaunas progressively broke down into metapopulations. as interbreeding became ever more infrequent, subpopulations were increasingly exposed to the effects of inbreeding, genetic drift as well as morphological change. when the intensity of interbreeding turned excessively low, evolutionary change tended to resemble that of insular settings (schmidt & jensen, 2003). numerous mammals grew smaller (e.g., edentates, mastodonts, wild boar, gazelle, goat, aurochs, bison, deer, fox, wildcat, spotted hyena, beech marten, burrowing mole rat, hedgehog, porcupine: kurtén, 1965; tchernov, 1968; frenkel, 1970; heller, 1970; mcdonald, 1981; king & saunders, 1984; martin, 1993; martin & barnosky 1993; wilson, 1996; barnosky et al., 2003; blackburn & hawkins, 2004, rodríguez et al., 2006, cooper & purvis, 2010; saunders et al., 2010), with results somewhat fitting the predictions of the so-called island rule (foster, 1964; sondaar, 1977). insular populations, both in true and ecological islands, are in fact under the control of strict genetic and ecological constraints (lomolino et al., 2010). as in true islands, in isolated ecosystems population densities are bracketed between a maximum number of individuals, determined by the carrying capacity of the environment, and a critical minimum number of individuals to prevent extinction. largesized animals seems to be left with no other choice but to decrease their size to lower selective pressure in insular isolation. 4. conclusions because mammal body size is most sensitive to ecological factors, size changes are often considered as a useful proxy indicator to monitor climatic changes, not only in the past. in fact, declining body size has recently been considered the third universal response to climate, together with changes in phenology and distribution of species (gardner et al., 2011). in his pioneer contribution bergmann (1847) stirred debate over the relation between temperature and body size. the controversy peaked over the years, with convinced supporters and opponents both with shrill and convincing arguments on the merits or shortcomings of bergmann’s rule. many body size fluctuations in quaternary hippopotamuses 71 studies have admirably shown that mammalian body size is governed by, and responds to, a number of factors, which include temperature, precipitation and moisture, physiologic constraints, basal metabolic rate and energy costs, environmental carrying capacity (food availability), degrees of environmental stability, interspecific competition, predator-prey interaction, just to mention some. a body size that is thought to be diagnostic of a particular environmental situation may actually arise for different reasons, being the result of the interplay of an array of factors which may be, to various degrees, interdependent. researchers involved with these issues are therefore confronted with a tangled network of related variables, which imposes to inquire each instance individually, on a case-by-case basis: model (“rule”) generalization is not easy to achieve. today, researchers could have the unprecedented opportunity to test the effects of global warming on fast-reproducing animals (e.g., gardner et al., 2011). paleoclimatological analysis and oxygen isotope curves clearly show that, with the outstanding exceptions of particularly warm episodes (e.g., mis 47, 37, 11, 9, 5e), earth’s climate has been progressively deteriorating over time, trending towards increasingly cooler and somewhat drier conditions. the escalating environmental patchiness during the quaternary translated into habitat fragmentation, and this in turn caused the splitting up of populations into subpopulations or metapopulations. owing to this parcelling of habitats and biotas, body size has been ever more under the influence of factors (e.g., food availability) that may not always operate or be accessible latitudinally, but rather areally, in accordance with the habitat specificity of the species (meiri et al., 2007). countless studies show that mammal body size change is a most effective sign of some ecological change, of whatever kind and degree (aragon et al., 2010). and possibly even a predictor of environmental instability. deepening our knowledge and understanding of this phenomenon can therefore be a promising direction for future research aimed at environmental monitoring. acknowledgements we thank e. russo-ermolli and one anonymous reviewer for useful suggestions which improved this paper. this study was funded by ex 60%miur (ministry of education, university and research) grants to p. mazza and a. bertini. references allen j.a. (1877) the influence of physical conditions in the genesis of species. radical review, 1, 108140. angilletta m.j., dunham a.e. (2003) the temperaturesize rule in ectotherms: simple evolutionary explanations may not be general. the american naturalist, 162, 332-342. aragon p., lobo j.m., olalla-tárraga m.a., rodriguez m.a. (2010) the contribution of contemporary climate to ectothermic and endothermic vertebrate distributions in a glacial refuge. global ecology and biogeography, 19, 40-49. ashton k.g. (2002) patterns of within-species body size variation of birds: strong evidence for bergmann’s rule. global ecology and biogeography, 11, 505-523. ashton k.g., tracy m.c., de queiroz a. (2000) is bergmann’s rule valid for mammals? american naturalist, 156, 390-415. barnosky a.d. (2005) effects of quaternary climatic change on speciation in mammals. journal of mammalian evolution, 12 (1/2), 247-264. barnosky a.d., hadly e.a., bell c.j. (2003) mammalian response to global warming on varied temporal scales. journal of mammalogy, 84(2), 354368. bellucci l., mazzini i., scardia g., bruni l., parenti f., segre a.g., segre naldini e., sardella r. (in press) the site of coste san giacomo (early pleistocene, central italy): palaeoenvironmental analysis and biochronological overview. quaternary international (2011), doi: 10.1016/j.quaint.2011.04.006. berger w.h., jansen e. (1994) mid-pleistocene climate shift. the nansen connection. in: johannessen et al., (eds) the polar oceans and their role in shaping the global environment. agu geophysical monograph, 85, 295-311. bergmann c. (1847) über die verhältnisse der wärmeökonomie der thiere zu ihrer grösse. göttinger studien, 3, 595-708. bertini a. (2003) early to middle pleistocene changes of the italian flora and vegetation in the light of a chronostratigraphic framework. il quaternario 16, 19-36. bertini a. (2010) pliocene to pleistocene palynoflora and vegetation in italy: state of the art. quaternary international, 225, 5-24, doi:10.1016/j.quaint.2010. 04.025. bertini a., ciaranfi n., marino m., palombo m.r. (2010) proposal for pliocene and pleistocene land-sea correlation in the italian area. quaternary international, 219, 95-108, doi:10.1016/j.quaint.2009.10. 026. bertoldi r., (1995) palinostratigrafia dei bacini intermontani dell’appennino nord-occidentale. il quaternario, 8(1), 61-70. blackburn t.m., gaston k.j. (1998) some methodological issues in macroecology. american naturalist, 151, 68-83. blackburn t.m., hawkins b.a. (2004) bergmann’s rule and the mammal fauna of northern north america. ecography, 27, 715-724. blackburn t.m., gaston k.j., loder n. (1999) geographic gradients in body size: a clarification of bergmann’s rule. diversity and distributions, 5, 165-174. blois j.l., hadly e.a. (2009) mammalian response to cenozoic climatic change. annual review of earth and planetary sciences 37,181-208 cita m.b. (1975) studi sul pliocene e gli strati di passaggio dal miocene al pliocene, viii. planktonic foraminiferal biozonation of the mediterranean pliocene deep sea record: a revision. rivista italiana di paleontologia e stratigrafia, 79, 503-558. combourieu-nebout n., vergnaud grazzini c. (1991) late pliocene northern hemisphere glaciations: the continental and marine responses in the central mediterranean. quaternary science reviews, 10, 319-334. cooper n., purvis a. (2010) body size evolution in mammals: complexity in tempo and mode. american naturalist,175, 727-738. mazza p.p.a., bertini a. 72 cruz l., cardenas v.m., abarca m., rodriguez t., reyna r.f., serpas m.v., fontaine r.e., beasley d.w., da rosa a.p., weaver s.c., tesh r.b., powers a.m., suarez-rangel g. (2005) serological evidence of west nile virus activity in el salvador. the american journal of tropical medicine and hygiene, 72, 612-615.. davis s. (1977) size variation of the fox, vulpes vulpes in the palaearctic region today, and in israel during the late quaternary. j. zool. lond., 182, 343-351. davis s. (1981) the effects of temperature change and domestication on the body size of late pleistocene to holocene mammals of israel. paleobiology, 7 (1), 101-114. diniz-filho j.a.f., bini l.m., rodríguez m.á., rangel t.f.l.v.b., hawkins b.a. (2007) -seeing the forest for the trees: partitioning ecological and phylogenetic components of bergmann’s rule in european carnivora. ecography, 30, 598-608. foster j.b. (1964) evolution of mammals on islands. nature, 202, 234-235. frenkel h. (1970) hystrix angressi sp. nov. on large fossil porcupine from the levalloiso-mousterian of the geula cave. israel j. zool., 19, 51-82. gardner j.l., peters a., kearney m.r., joseph l., heinsohn r. (2011) declining body size: a third universal response to warming? trends in ecology and evolution, 26(6), 285-291. gaston k.j., davies r.g., david c., orme l., olson v.a., thomas g.h., ding t-s., rasmussen p.c., lennon j.j., bennett p.m., owens i.p.f., blackburn t.m. (2007) spatial turnover in the global avifauna. proceedings: biological sciences, 274 (1618), 1567-1574. gibbard p.h., boreham s., cohen k.m., moscariello a. (2005) global chronostratigraphical correlation table for the last 2.7 million years. boreas, 34(1), unpaginated, modified/updated 2007. gliozzi e., abbazzi l., argenti p., azzaroli a., caloi l., capasso barbato l., di stefano g., esu d., ficcarelli g., girotti o., kotsakis t., masini f., mazza p., mezzabotta c., palombo m.r., petronio c., rook l., sala b., sardella r., zanalda e., torre d. (1997) biochronology of selected mammals, molluscs and ostracods from the middle pliocene to the late pleistocene in italy. the state of the art. rivista italiana di paleontologia e stratigrafia, 103 (3), 369-388. gonzález-sampériz p., leroy s.a.g., carrión j. s., fernández s., garcía-antón m., gil-garcía m.j., uzquiano p., valero-garcés b., figueiral i. (2010) steppes, savannahs, forests and phytodiversity reservoirs during the pleistocene in the iberian peninsula. review of palaeobotany and palynology, 162, 427-457. graham r.w., lundelius e.l.jr. (1984) coevolutionary disequilibrium. in martin p. s., r.g. klein, (eds). quaternary extinctions. university of arizona press, tucson, 223-249. guthrie r.d. (1984) alaskan megabucks, megabulls, and megagrams: the issue of pleistocene gigantism. in: genoways h.h., dawson m.r., (eds) contributions in quaternary vertebrate paleontology: a volume in memorial to john e. guilday. special publication no. 8. carnegie museum of natural history, pittsburgh, pennsylvania, usa, 482-510. hansson l., jaarola m. (1989) body size related to cyclicity in microtines: dominance behaviour or digestive efficiency? oikos, 55 (3), 356-364. heller j. (1970) small mammals of the geula cave. israel j. zool., 19, 1-50. huston m.a., wolverton s. (2011) regulation of animal size by enpp, bergmann’s rule, and related phenomena. ecological monographs, 81(3), 349-405. james f.c. (1970) geographic size variation in birds and its relationship to climate. ecology, 51, 365390. janis c.m. (1990) correlation of cranial and dental variables with body size in ungulates and macropodoids. in: damuth j., macfadden b.j., (eds) body size in mammalian paleobiology: estimation and biological implications. cambridge university press, cambridge, 255-299. joannin s., bassinot f., combourieu-nebout n., peyron o., beaudouin c. (2011) vegetation response to obliquity and precession forcing during the midpleistocene transition in western mediterannean region (odp site 976). quaternary science review, 30, 280-297. king j.e., saunders j.j. (1984) environmental insularity and the extinction of the american mastodont. in: martin p.s., klein r.g., (eds) quaternary extinctions. the university of arizona press, tucson, 315-339. klein r.g. (1986) carnivore size and quaternary climatic change in southern africa. quaternary research, 26, 153-170. kurtén b. (1965) carnivora of the palestine caves. acta zool. fennica, 107, 1-74. kurtén b. (1968) pleistocene mammals of europe. weidenfeld and nicolson, london. kurtén b. (1972) the age of mammals. columbia univ. press, new york. lande r., arnold s.j. (1983) the measurement of selection on correlated characters. evolution, 37, 1210-1226. lang g. (1994) quartäre vegetationsgeschichte europas. gustav fischer, jena. lister a., bahn p. (1994) mammoths. macmillian, new york, ny. lomolino m.v., riddle b.r., whittaker r.j., brown j.h. (2010) biogeography. sinauer associates, sunderland, ma. lourens l., hilgen f., shackleton n.j., laskar j., wilson d. (2004) the neogene period. in gradstein f.m., ogg j.g., smith a.g., (eds) a geological time scale, cambridge university press, cambridge, 409-440. magri d., palombo, m.r. (in press) early to middle pleistocene dynamics of plant and mammal communities in south west europe, quaternary international (2012), doi: 10.1016/j.quaint.2012.02.028 makarieva a.m., gorshkov v.g., li. b.l. (2005) temperature-associated upper limits to body size in terrestrial poikilotherms. oikos, 111, 425-436. markova a.k., simakova a.n., puzachenko a. yu., kitaev l.m. (2001) eastern european mammoth distribution and environments during the middle body size fluctuations in quaternary hippopotamuses 73 valdai briansk interstade (33,000-24,000 bp). in: cavaretta g., gioia p., mussi m., palombo m.r. (eds) the world of elephants. proceedings 1st international congress the world of elephants,16-20 october 2001, rome, 299-304. martin p.s. (1984) prehistoric overkill: a global model. in: martin p.s., klein r.g., (eds) quaternary extinctions, a prehistoric revolution: university of arizona press, tucson, 451-465. martin r.a. (1993) patterns of variation and speciation in quaternary rodents. in: martin r.a., barnosky a.d., (eds) morphological change in quaternary mammals of north america, cambridge university press, cambridge, 226-280. martin r.a., barnosky a.d. (1993) morphological change in quaternary mammals of north america. cambridge university press. 415 pp. mazza p. (1995) new evidence on the pleistocene hippopotami of western europe. geologica romana 31, 61-241. mcdonald j.n. (1981) north american bison: their classification and evolution. university of california press, berkeley, ca. mcdonald j.n. (1984) the reordered north american selection regime and late quaternary megafaunal extinctions. in: martin p. s., klein r. g., (eds) quaternary extinctions, a prehistoric revolution: university of arizona press, tucson, 404-439. mclean d.m. (1991) a climate change mammalian population collapse mechanism. in: kainlauri e., johansson, a., kurki-suonio i., geshwiler m., (eds) energy and environment, atlanta, georgia, ashrae, 93-100. mein p. (1979) vertebrate report activity. vii international congress on the mediterranean neogene, athens. annales géologiques des pays helléniques, 3, 1367-1372. meiri s. (2011) bergmann’s rule – what’s in a name? global ecology and biogeography, 20, 203-207. meiri s., dayan t. (2003). on the validity of bergmann’s rule. journal of biogeography, 30, 331-351. meiri s., gavin h.t. (2007) the geography of body size challenges of the interspecific approach. global ecology and biogeography, 16, 689-693. meiri s., dayan t., simberloff d. (2004) carnivores, biases and bergmann’s rule: biological journal of the linnean society, 81, 579-588. meiri s., yom-tov y. geffen e. (2007) what determines conformity to bergmann’s rule? global ecology and biogeography,16, 788-794. merilees d. (1984) comings and goings of late quaternary mammals near perth in extreme southwestern australia. in: martin p.s., klein r.g., (eds) quaternary extinctions, a prehistoric revolution: university of arizona press, tucson, 629-638. millien v., kathleen l.s., olson l., smith f.a., wilson a.b., yom-tov y. (2006) ecotypic variation in the context of global climate change: revisiting the rules: ecology letters, 9 (7), 853-869. prange h. d., anderson j. f., rahn, h. (1979) scaling of skeletal mass to body mass in birds and mammals. american naturalist 113, 103-122. reitz e.j., quitmyer i.r. (1988) faunal remains from two coastal georgia swift creek sites. southern archaeology 7, 95-108. reumer j.w.f. (2007) habitat fragmentation and the extinction of mammoths (mammuthus primigenius, proboscidea, mammalia): arguments for a causal relationship. in: kahlke r.-d., maul l.c., mazza p.p.a., (eds) late neogene and quaternary biodiversity and evolution: regional developments and interregional correlations: proceedings of the 18th international senckenberg conference (vi international palaeontological colloquium in weimar), 2, 279-286. rio d., raffi i., villa g. (1990) pliocene-pleistocene calcareous nannofossil distribution patterns in the western mediterranean. in: kastens k.a., mascle j. et al., proceedings odp scientific results, 107. college station, 513-533. rodríguez m.á., lópez-sañudo i.l., hawkins b.a. (2006) the geographic distribution of mammal body size in europe. global ecology and biogeography, 15, 173-181. rodríguez m.á., olalla-tárraga m.a., hawkins b.a., (2007) bergmann’s rule and the geography of mammal body size in the western hemisphere. global ecology and biogeography 17, 274-283, doi: 10.1111/j.1466-8238.2007.00363.x rodriguez-sanchez f., hampe a., jordano p., arroyo j. (2010) past tree range dynamics in the iberian peninsula inferred through phylogeography and palaeodistribution modelling: a review. review of palaeobotany and palynology 162, 507-521. rosenzweig m.l. (1968) the strategy of body size in mammalian carnivores. american midland naturalist, 80, 299-315. saunders j.j., grimm e.c., widga c.c., campbell g.d., curry b.b., grimley d.a.,hanson p.r., mccullum j.p., oliver j.s.,treworgy, j.d. (2010) paradigms and proboscideans in the southern great lakes region, usa. quaternary international, 217(1-2), 175-187. schmidt n.m., jensen p.m. (2003) changes in mammalian body length over 175 years – adaptations to a fragmented landscape? conservation ecology, 7(2), 6 (published online). schmidt-nielsen k. (1984) scaling: why is animal size so important? cambridge university press, cambridge. scholander p.f. (1955) evolution of climatic adaptation in homeotherms. evolution, 9, 15-26. simakova a.a. (2001) the vegetation and mammoth distribution during the second half of the late pleistocene on the russian plain (33-17 ka). in: cavaretta g., gioia p., mussi m., palombo m.r., (eds) proceedings 1st international congress the world of elephants,16-20 october 2001, rome, 355-359. simberloff d., boecklen w. (1981) santa rosalia reconsidered: size ratios and competition. evolution, 35, 1206-1228. sondaar p.y. (1977) insularity and its effect on mammal evolution. in: hecht m.k., goody p.c., hecht b.m., (eds) major patterns in vertebrate evolution: plenum press, new york, 671-707. steudel k.l., porter w.p., sher d. (1994) the biophysics of bergmann’s rule: a comparison of the effects of pelage and body size variation on metabolic rate. mazza p.p.a., bertini a. 74 canadian journal of zoology, 72, 70-77. suc j-p., bertini a., combourieu-nebout n., diniz f., leroy s., russo-ermolli e., zheng z., bessais e., ferrier j. (1995) structure of west mediterranean vegetation and climate since 5.3 ma. acta zoologica cracoviense, 38, 3-16. tchernov e. (1968) succession of rodent faunas during the upper pleistocene of israel. paul parey, hamburg and berlin. teplitsky c., mills j.a., alho j.s., yarrall j.w., merilä j. (2008) bergmann’s rule and climate change revisited: disentangling environmental and genetic responses in a wild bird population. proceedings of the national academy of sciences of the usa, 105, 13492-13496. thompson d.w. (1942) on growth and form. cambridge university press, cambridge. tzedakis p.c. (2007). seven ambiguities in the mediterranean palaeoenvironmental narrative. quaternary science reviews, 26, 2042-2066. tzedakis p.c., mcmanus j., hooghiemstra h., oppo d., wijmstra t.a. (2003). comparison of changes in vegetation in northeast greece with records of climate variability on orbital and suborbital frequencies over the last 450,000 years. earth and planetary science letters, 212, 197-212. ward p. (1997) the call of distant mammoths: why the ice age mammals disappeared. copernicus, new york, new york, usa. wilson m.c. (1996) late quaternary vertebrates and the opening of the ice-free corridor, with special reference to the genus bison. quaternary international, 32, 97-105. yom-tov y., geffen e. (2006) geographic variation in body size: the effects of ambient temperature and precipitation. oecologia, 148, 213-218. yom-tov y., nix h. (1986) climatological correlates for body size of five species of australian mammals. biological journal of the linnean society, 29, 245– 262. zazula g.d., froese d.g., schweger c.e., mathewes r.w., beaudoin a.b., telka a.m., harington c.r., westgate j.a. (2003) ice-age steppe vegetation in east beringia. nature, 423, 603. ms. received: january 20, 2012 final text received: march 13, 2012 amq29(1) 5 bartolini 67-76.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 29 (1), 2016, 67 75 lively drainage of the northern apennine * carlo bartolini formerly at dipartimento di scienze della terra, università di firenze, italy corresponding author: c. bartolini <carlo.bartolini@unifi.it> abstract: in the northern apennine nw to sw oriented structures influence not only main water courses, largely hosted in the plio-quaternary basins (mazzanti & trevisan, 1978), but also minor streams located close to the present apennine watershed. because of their location close the drainage divide, where the exhumation rate is at present faster, these minor river segments have developed in recent time (late middle and mostly upper pleistocene), when the litho-structural discontinuities on which presently they are set, became exhumed. river piracies affecting these streams are even more recent events and were triggered by the on-going regional uplift. in the high reggio emilia – modena apennines, the alignment of ozola, dolo, dragone and perticara upper river segments, oriented nw-se, is controlled by weak-impermeable lithologies outcropping on a thrust front. in the frignano area, the evolution of the drainage network was deeply conditioned by the presence of lithologies featuring different erodibilities. the ombrone pistoiese upper basin drainage is presently featuring a series of river piracies driven by the marked asymmetry of the watershed in that area. lithologic discontinuities on the one side and middle-upper pleistocene widespread uplift on the other controlled the drainage evolution in the whole area. key words stream patterns, middle and upper pleistocene, northern apennine. 1. introduction stream patterns are basically controlled by two conflicting constraints: the gradient of the slope where they formerly originated and, if any, a lithostructural control of their path (twidale, 2004). the geologic control is frequently not obvious because the river segment emplacement took place at higher crust levels (eventually wiped away by the erosion) featuring a different geologic frame. the aim of the present paper is to show that water courses flowing in the proximity of the present northern apennine watershed were recently captured, due to the ongoing uplift, by transverse streams, deeply controlled, in their evolution, by lithologic discontinuities. captures occurring close to the watershed, both on the adriatic and on the tyrrhenian side mime, at a larger scale, the events which took place in the middle pleistocene chain uplift (bartolini, 2003) which induced a low relief area, scattered with swamps and ephemeral lacustrine basins to be uplifted and dissected. the intervening increase in the uplift/denudation rates is supported by the onset of a fast prograding sedimentation pattern since 1.0-0.8 ma b.p. on both the padan and the tyrrhenian side of the apennines (argnani et al., 1997; carminati et al., 1999). the uplift resulted in the shift from an internally drained fluvio-lacustrine system to an open, through going (i.e. exorheic) river system (bartolini & pranzini, 1981; d'agostino et al., 2001; bartolini et al., 2003). the along trend rivers, draining the newly formed intermountain depressions, were captured, originating the present, peculiar drainage pattern formerly described by mazzanti & trevisan (1978). namely the arno river upper reaches, the sieve, the lima and others rivers assumed, by capture, their present hook shaped geometry (fig.1). 2. the role of differential uplift the detailed appraisal of drainage rearrangement by capture carried out by bishop (1995) appears to correctly fit the features evidenced in the northern apennine. the middle and upper pleistocene uplift of the northern apennine although ubiquitous, was highly differentiated following the structural setting. the hook shaped lima river course (fig. 2) was since long (camerini, 1942) interpreted as the output of a ------------------------------------- *the present paper lately spread from the oral presentation “bartolini c. & forzoni a. (2009) northwesterly trending river segments of the northern apennine within an uplifting chain.” geoitalia 2009 (abstract). 68 bartolini c. f ig . 1 in ve st ig at ed a re as . r iv er e lb ow s ar e a co m m on fe at ur e of th e t us ca n dr ai na ge . d t m 1 0x 10 m . h ttp :// w w w .r eg io ne .to sc an a. it/ w eb /g eo bl og //o pe nge od at a. t y r r h e n i a n s e a e m i l i a p is a lu c c a p is t o ia f ir e n z e n i n e s a d r i a t i c s e a t y r r h e n i a n s e a p o p la in s tu d ie d a re a 10 0 km t u s c a n y e n a p 69 river paths northern apennine capture. the capture kinematics were, however, only recently investigated (bartolini & fazzuoli, 1998): the detailed appraisal of the quaternary kinematics of the val di lima structural high showed that the lima river, as well as several of his tributaries, are now located within the most uplifted fault blocks (fig. 3). due to the uplift, a former along trend drainage (fig. 4) has been partially redirected at right angles. 3. hydrographic evolution of three areas in the northern apennine driven by the geological frame 3.1. reggio emilia – modena apennine 3.1.1. 1 passo delle radici the drainage of this area, fringing the apennine watershed, is characterized by the alignment of four river segments belonging to ozola, dolo, dragone and perticara (figs. 5, 6 and 7). these segments, which make up river heads, are nw-se oriented. after flowing a few kilometres in this direction, the four streams become deflected towards the ne (i.e. to pianura padana and the adriatic sea). southwest of the alignment made up by the four mentioned streams, the main water courses flow to se towards the serchio basin. the headwaters of one of these, the castiglione river, created a bulge in the watershed, due to its valley extension, which divides the ozola and dolo area from the dragone and perticara one (fig. 5). the valley extension of the castiglione upper river basin was favoured by the ongoing subsidence of the serchio structural basin as well as to the shaly monte modino unit widely outcropping in the upstream castiglione river basin. the regressive erosion prompted by the sinking serchio basin is evidenced by the asymmetry of the apenninic divide in this sector (fig. 7). these four segments are located on shalemarly formations outcropping in front of a thrust (fig. 6a, b) made up of olistosthromes, ramp muds, draping muds, chaotic substratum of fore-trench flysch. as a matter of fact, during a late compressive phase of the apennine chain build up (late miocene-pliocene) they acted as a decollement horizon in the thrust of macigno sandstones over monte modino sandstones. due to the regional fig. 2 the hook shaped and geographic setting of lima river. figs. 3 and 4 ubcation is also shown. fig. 3 middle-upper pleistocene uplift in the lima river basin area. from bartolini & fazzuoli, 1998. fig. 4 the supposed former along strike streams of the lima and serchio region, strongly controlled by the structural setting. from bartolini & fazzuoli, 1998. 1: normal fault; 2: thrust; 3: former tyrrhenian adriatic divide; 4: former fluvial branches, presently wiped out. fig. 4 fig. 3 uplift, these formations became stripped and are presently undergoing rapid erosion. the evolution of the hydrography in this area is here outlined. macigno and mt. modino formations as well as the shale-marly weakness belt (fig. 6 b) became exhumed during middle pleistocene. since the four river segments flow over such lithologies, their onset is coeval with their exhumation. the perticara headwaters stretched out until reaching the shalemarly weakness belt (figs. 6 a,b), there disrupting an along-strike river system approximately located along the present apenninic divide (fig. 5). the upheaval of the chain triggered also the captures by the dolo and the dragone streams (fig. 7). 3.1.2. frignano the south-west side of the area is characterized by thrusts (monte modino and cervarola units) while the middle and the northern sectors were fragmented into blocks by fault systems in a late orogenic phase. the geometric vertical location of lithologies featuring different erodibilities in the uplifted or in lowered blocks conditioned the evolution of the drainage network. in general, the hydrography of the area features an anti-apenninic orientation, as a consequence of the ongoing uplift. a particular feature of the middle modena apennine is however the striking deflection of the scoltenna river (fig. 5). its upper course flows towards ne, therefore perpendicular to the apenninic divide, pushing his river head far beyond the alignement of the former apenninic divide, presently marked by mt. cimone, the highest peak in this sector of the chain (fig. 5). the remarkable erosive energy of this river derives from the largely impermeable lithology of the valley bottom in its lower course (see ahead). upslope from the confluence into the panaro river, the scoltenna river is instead oriented nw-se and aligned with the dardagnola river course. they both lay over a large outcrop of clay and shale dominated ligurids (unità leo), which foster surface runoff (figs. 8, 9). the 1:100.000 geological map of italy (fig. 10) shows that a thin, elongated lacustrine and alluvial body overlies the bismantova group (formazione di pantano and formazione di cigarello, bettelli et al., 2002) slab in the frignano area. the wide valley lying today on top of the epiligurian slab (fig. 11) is a late relict of a former valley bottom of the scoltenna river, subsequently captured by the very active leo – panaro system, mostly located 70 fig. 6a ozola, dolo, dragone and perticara rivers and their geological setting. from carta strutturale 1:200.000 sheet 236 ”pavullo nel frignano”. fig. 6b geological section across ozola river (location in fig. 6a). from carta geologica 1:50.000 sheet 236 ”pavullo nel frignano”. fig. 7 western sector: captures by the dolo and the dragone rivers. in the eastern sector of the dtm, a left tributary of the leo panaro rivers, flowing over the shaly “argille a palombini” auctt. stretched out its headwaters to nw and eventually captured the paleo-scoltenna river. fig. 5 reggio emilia-modena and northern tuscany apennine: ozola, dolo, dragone, perticara rivers then scoltenna and castiglione rivers upper courses in the passo delle radici area; headward enlargment of the castiglione river resulting in a wateshed bulge; scoltenna, leo and panaro rivers drainage pattern in the frignano area. figs. 6, 7, 8 and 10 ubcation is also shown. m. cimone m. cantiere pavullo nel frignano fig. 10 fig. 8 fig. 7 fig. 6 m. cervarola bartolini c. 71 fig. 9 cross section of the scoltenna river (location in fig. 8). from schema tettonico, sheet 236 ”pavullo nel frignano”, modified. on the shaly dominated “argille a palombini” auctt. belonging to the ligurian units. the latter appear separated form the epiligurian slab in section a – a’ (fig. 9) by a subvertical tectonic contact. the epiligurian units are instead plainly overlying the ligurian units on the southeastern margin of the frignano area (fig. 12). during early middle pleistocene times the epiligurids widely outcropped in this area with their uppermost relatively impermeable units (formazione di cigarello) supporting a mostly ne trending drainage. as soon as the epligurids became stripped by erosion, the exposure of the impermeable and incompetent ligurids units, and namely of the shaly “argille a palombini”, promoted a deep rearrangement of the drainage pattern (fig. 13). in the mean time, the frignano area became an upland where karstic processes (fig. 14) slowly obliterated the former fluvial features. panizza (1968) and panizza & mantovani (1974) correctly read the frignano central smooth depression as a polje, and realized that the peculiar lithological setting of the frignano slab had a deep impact on the hydrographic pattern evolution. as a matter of fact, the scoltenna r. after fringing to the east the frignano upland (which is presently disrupted by the regressive erosion of lerna stream, a left hand tributary of panaro river, see figs. 12, 13), farther ahead in its course bends again to the west thus bypassing the epiligurid zocca upland (fig. 9a). the present day altitude drop between the scoltenna river at the piracy elbow (figs. 5, 8, 9, 10, 11, 13) and the southwestern edge of the frignano plate overlooking the scoltenna river valley is 300 m. the river capture sensibly favoured by lithology took place most likely in late middle pleistocene times within a rapidly uplifting mountain chain. the rocks which mostly favoured the entrenching of the rivers are the sedimentary melanges of the ligurids, the weakest and most impermeable of lithologies making up the northern apennine. these events point out the relevant role of the lithological control presently exerted on the chain morphology. the role of lithology in driving the morphological features of the apenninic chain has been recently regarded as marginal or irrelevant by salustri galli et al., (2002) who state that “the lithologies fig. 10 geology of the upland frignano area and setting of scoltenna river. from geological map of italy 1:100.000, sheet 82, modena. river paths northern apennine fig. 8 geological setting of panaro and scoltenna rivers. from schema tettonico, sheet 236 ”pavullo nel frignano”, modified. 72 fig. 11 air view of the frignano axial depression hosting pavullo airport. fig. 12 air view of the geologic contact (red line) between the arenarie di bismantova and the underlying shaly ligurian units. the lerna stream headward erosion (see text) is evidenced. ---------------------------------------------- fig. 13 morphologic evolution of the frignano area in middle to late pleistocene times (courtesy by cristina andreani). during the middlelate pleistocene regional upheaval, the rivers draining towards ne, which were located in the areas where the ligurian units lay closer to the topographic surface, were the first ones who could reach, in their downward erosive path, the melanges horizons; they therefore outweighed, since then, the adjacent water courses located over less actively uplifting areas. the panaro-leo drainage was more favoured, by this configuration, than the paleo-scoltenna one. while the paleoscoltenna river lower course was still flowing on the competent and permeable epiligurids (calcarenites and sandstones) the panaro river down-cutting reached the ligurids melanges, which gave a further impulse to its down-cutting. somewhere south of pavullo a left tributary of panaro river stretched out its headwater to nw and eventually captured the paleo-scoltenna river (see fig. 7). the morphology around the new course of the scoltenna river, which became entirely set on the sedimentary melanges, rejuvenated. bartolini c. 73 fig. 14 karstic processes at ponte del diavolo, 6 km wsw from pavullo. fig. 15 ombrone pistoiese and reno rivers upper reaches. figs. 16 and 17 ubcation is also shown. fig. 17 drainage pattern of the ombrone river upper reach area. fig. 18 drainage pattern and geological sckech map of the reno river upper reach area, modified after dallan et al., (1981). fig. 16 along profile of the reno and the ombrone pistoiese rivers. river paths northern apennine fig. 18 fig. 17 of the outcropping belt are fairly homogeneous”. according to these authors, “the highest peaks are generated by tectonics, minus erosion”. this statement is criticized by bartolini (2012). 3. 2. ombrone pistoiese vs, reno river the baselevel of the ombrone river, a right hand tributary of the arno river (fig.1), is located on a plain to which florence also belongs i.e. on the subsiding floor of an intermountain basin. due the proximity of the plain to the tyrrhenianadriatic watershed, the river profile is quite steep, mostly if compared with the reno river (fig. 16) which has its baselevel on the quite distant adriatic sea. a flysch formation of homogeneous lithology (cervarola fm.) extensively outcrops in this particular sector of the watershed area, hampering any possible control of the lithology on the erosive processes occurring on either side. the asymmetry of the watershed originates, now as well as it did in the in the recent past, a wealth of minor captures (fig. 17). a few of them affected small streams aligned along strike which are remnants of a former drainage, as it has been the case of the upper dolo and ozola reaches. as a result of the captures, the reno river lacks right end tributaries. to the nw, instead, the upper reno river reaches are actively eroding upstream, thus pushing in this sector the watershed to the west and reversing the trend described above (fig. 18). the reno uppermost river profile appears accordingly fairly steep and incongruous with the following profile sector (see fig. 16). here the cause is lithologic, as fig. 18 reveals: the prevailing argillitic lithology of two units interposed between falda toscana and cervarola falterona units drove the captures and thence the southwesterly bulge in the watershed. 4. conclusive remarks in the fringe of the present northern apenninic divide a few river segments trend along strike although in the progress of being beheaded by streams flowing at right angle. the occurrence of such segments, until present unaffected by the orographic consequence of the ongoing uplift, points both to its recent age (bartolini 2003, references therein) and to its fast pace (carminati et al., 1999; zattin et al., 2002; balestrieri et al., 2003). references argnani a., bernini m., didio g.m., papani g., rogledi s. (1997) registrazione stratigrafica di eventi tettonici a scala crostale nei depositi quaternari del nordappennino. abstracts convegno tettonica quaternaria del territorio italiano: conoscenze, problemi, applicazioni. parma, february 25-27. balestrieri m.l., bernet m., brandon m.t., picotti v., reiners p., zattin m. (2003) pliocene and pleistocene exhumation and uplift of two key areas of the northern apennines. quaternary international, 101-102, 67-73. bartolini c. (2003) when did the northern apennine become a mountain chain?. quaternary international, 101-102, 75-80. bartolini c. (2012) is the morphogenetic role of tectonics overemphasized at times?. boll. geofisica teorica e applicata, 53, 459-470. bartolini c., d’agostino n., dramis f. (2003) topography, exhumation, and drainage network evolution of the apennines. episodes, 26 (3), 212-216. bartolini c., fazzuoli m. (1998) ruolo della tettonica e della morfoselezione nell'evoluzione dell'idrografia nel bacino del fiume serchio. il quaternario, 10, 417-426. bartolini c., forzoni a. (2009) northwesterly trending river segments of the northern apennine within an uplifting chain. proc. congresso fist geoitalia, rimini, italy, settembre 9-11, abstracts. bartolini c., pranzini g. (1981) plio-quaternary evolution of the arno basin drainage. zeitschrift für geomorphologie n.f., supplementband 40, 77-91. bettelli g., panini f., pizziolo m. (2002) note illustrative della carta geologica d’italia, foglio 236, pavullo. selca, firenze, pp. 168. bishop p. (1995) drainage rearrangement by river capture, beheading and diversion. progress in physical geography, 19, 449-473. camerini c. (1942) probabile fenomeno di cattura dell'alto reno nell'appennino pistoiese. rivista geografica italiana, 49, 126-137. carminati e., giunchi c., argnani a., sabadini r., fernandez m. (1999) plio-quaternary vertical motion of the northern apennines: insights from dynamic modelling. tectonics, 18, 703718. d’agostino n., jackson j., dramis f., funiciello r. (2001) interactions between mantle upwelling, drainage evolution and active normal faulting: an example from the central apennines (italy). geophysical journal international, 147, 475-497. dallan l., puccinelli a., verani m. (1981) geologia dell’appennino settentrionale tra l’alta val di lima e pistoia. bollettino della società geologica italiana, 100, 567-586. mazzanti r., trevisan l. (1978) evoluzione della rete idrografica nell'appennino centrosettentrionale. geografia fisica e dinamica quaternaria, 1, 55-62. panizza m. (1968) l’evoluzione geomorfologia e idrografica del territorio di pavullo nel frignano. s.t.e.m. mucchi, modena, 14 pp. panizza m., mantovani f., (1974) geomorfologia del territorio di pavullo nel frignano (appennino modenese). atti società naturali 74 bartolini c. sti e matematici di modena, 105, 85-117. salustri galli c., torrini a., doglioni c., scrocca d. (2002) divide and highest mountains vs subduction in the apennines. studi geologici camerti, 1, 143-153. twidale c.r. (2004) river patterns and their meaning. earth-sciencereviews, 67, 159-218. zattin m., picotti v., zuffa g.g. (2002) fissiontrack reconstruction of the front of the northern apennine thrust wedge and overlying ligurian unit. american journal of science, 302, 346-379. ms. received: november 11, 2015 final text received: january 22, 2016 75 river paths northern apennine 76 << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /none /binding /left /calgrayprofile (dot gain 20%) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /error /compatibilitylevel 1.4 /compressobjects /tags /compresspages true /convertimagestoindexed true /passthroughjpegimages true /createjobticket false /defaultrenderingintent /default /detectblends true /detectcurves 0.0000 /colorconversionstrategy /cmyk /dothumbnails false /embedallfonts true /embedopentype false /parseiccprofilesincomments true /embedjoboptions true /dscreportinglevel 0 /emitdscwarnings false /endpage -1 /imagememory 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/hrv (za stvaranje adobe pdf dokumenata najpogodnijih za visokokvalitetni ispis prije tiskanja koristite ove postavke. stvoreni pdf dokumenti mogu se otvoriti acrobat i adobe reader 5.0 i kasnijim verzijama.) /hun 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can be opened with acrobat and adobe reader 5.0 and later.) >> /namespace [ (adobe) (common) (1.0) ] /othernamespaces [ << /asreaderspreads false /cropimagestoframes true /errorcontrol /warnandcontinue /flattenerignorespreadoverrides false /includeguidesgrids false /includenonprinting false /includeslug false /namespace [ (adobe) (indesign) (4.0) ] /omitplacedbitmaps false /omitplacedeps false /omitplacedpdf false /simulateoverprint /legacy >> << /addbleedmarks false /addcolorbars false /addcropmarks false /addpageinfo false /addregmarks false /convertcolors /converttocmyk /destinationprofilename () /destinationprofileselector /documentcmyk /downsample16bitimages true /flattenerpreset << /presetselector /mediumresolution >> /formelements false /generatestructure false /includebookmarks false /includehyperlinks false /includeinteractive false /includelayers false /includeprofiles false /multimediahandling /useobjectsettings /namespace [ (adobe) (creativesuite) (2.0) ] /pdfxoutputintentprofileselector /documentcmyk /preserveediting true /untaggedcmykhandling /leaveuntagged /untaggedrgbhandling /usedocumentprofile /usedocumentbleed false >> ] >> setdistillerparams << /hwresolution [2400 2400] /pagesize [612.000 792.000] >> setpagedevice amq29(1) 4 giraudi 45-66.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 29 (1), 2016, 45-65 the evolution of the northernmost apennine front (piedmont, italy): plio-pleistocene sedimentation and deformation in the po basin and monferrato hills carlo giraudi enea c.r. saluggia, vercelli, italy corresponding author: c. giraudi <carlo.giraudi@enea.it> abstract: the area under investigation includes the southern vercelli plain and the lower cerrina valley, in the northern central monferrato hills. the comparison between the deformation of the sediments of the foredeep basin, north of the monferrato thrust front, and of the cerrina valley syncline, south of the front, enabled our understanding of the pliocene and pleistocene environmental and tectonic evolution to be improved. the study of the plio-pleistocene sedimentary successions allowed the phases of subsidence and deformation produced by the compressive tectonic to be dated. the subsidence involved the po foredeep basin and the cerrina valley syncline during the same periods, but with different intensity. a first phase of subsidence occurred before the sub-chron olduvai, while the second phase can be dated between about 1.5 and 0.5 ma ago, but the maximum subsidence rate occurred around 1.07 and 0.99 ma ago. also the main deformation phases of the cerrina valley syncline are coeval with the activity of the lucedio and cavourrina faults, that correspond to two different buried thrust fronts. the lucedio fault is linked to the gaminella-cerrina valley syncline through the nw-se trending crescentino fault (west) and the n-s trending salera line (east) acting as ramps, while the ramps linking the cavourrina fault to the syncline are the nne-ssw trending fontanetto po (west) and the n-s trending trino (east) deformation zones. the tectonic frame indicates that the syncline corresponds to a trough behind the thrust front. however, the asymmetry of the cerrina valley in its stretch with a w-e orientation, and the presence of a sequence of terraces only on the northern side, suggest that the hills north of the valley were gently uplifted at least until the upper pleistocene. it follows that the syncline may have acted, until very recent times, as a boundary between two hilly areas (north and south of the valley) subject to different tectonic evolution. the results of the research suggest that the river, which entered the cerrina valley during the early and middle pleistocene, was probably fed by the alpine valleys lying sw of the aosta valley, or a collector of the streams that drained the northern monferrato. keywords: vercelli plain, northern monferrato hills, cerrina valley, po foredeep basin, monferrato thrust front, plio-pleistocene marine and continental sediments, geological and tectonic evolution 1. introduction the monferrato and turin hills are extensions to the nw of the northern apennine (fig. 1a). behind the monferrato thrust fronts, active also in plio-quaternary times (fig. 1b), deep piggyback basins are present: the subsidence in the basins was contemporary with the compressional tectonic (dela pierre et al., 1995; irace et al., 2009). the monferrato-turin hills thrust front is formed by three stretches with different characteristics. the eastern monferrato thrust front (fig. 1b) was active until, at least, the late middle pleistocene (giraudi, 2015a) and in the hills south of the front, according to livio et al. (2015), some tectonic deformations occurred also during the holocene. south of the eastern monferrato lies the alessandria basin, which seems to be subsiding also during the present time (devoti et al., 2011). south of the front of the torino hills and the western monferrato (fig. 1b), active in plio-pleistocene times (until early or middle pleistocene, according to pieri & groppi, 1981; cassano et al., 1986; galadini et al., 2012; galli et al., 2012), lies the saluzzo basin, which subsided during the same period. the central monferrato thrust front (fig. 1b), buried under quaternary sediments of the po plain between crescentino and trino, was active in more recent times than the western one (dela pierre et al., 2003a;b). near trino, the compressive tectonic ended before 300 ka bp (probably around 400 ka bp) according to giraudi (2014). according to michetti et al. 2012 and burrato et al. 2012) the compressive tectonic could still be active. the boundary area between the saluzzo and alessandria basins, called the asti basin in the present paper (fig. 1b), lies south of the central monferrato front. the asti basin was subsiding until the early pliocene but from the middle pliocene the area underwent a slow uplift (dela pierre et al. 2003a;b). it is clear that after the early pliocene the asti basin ceased acting as a piggyback basin and no correlation with the later compressional tectonic of the central monferrato thrust front can be assumed. in the hilly area located south of the trino front, however, there is an area where continental sediments, contemporary with the phases of thrust activity, are out 46 giraudi c. cropping: the lower cerrina valley. the preliminary comparison between the tectonic and sedimentary evolution of the basin north of the thrust front and of the lower cerrina valley enabled it to be assumed that the valley, after the lower pliocene, became a tectonic trough produced by the migration of the front (giraudi, 2015b). the aim of the present paper is to discuss the tectonic evolution of the thrust front and to make a more detailed comparison between the evolution of the foredeep basin north of the thrust front and that of the cerrina valley, in order to verify the reliability of some hypotheses reported above and to improve the understanding of the pliocene-pleistocene evolution of the monferrato front and define its chronology. the conclusions reached below are based mainly on data reported in literature supported by the stratigraphy of some boreholes drilled in the cerrina valley and on the presence of tectonic structures affecting tertiary sediments outcropping in the po riverbed. the area under investigation includes the southern vercelli plain and the lower cerrina, valley, that is the valley of the stura di monferrato stream (fig. 2). about the vercelli plain, the present paper will present and discuss mainly the data for the pliocene and pleistocene marine sediments and early pleistocene continental sediments, because in a previous paper (giraudi, 2014) the activity of the front during the past 870 ka was already discussed. fig. 1 geological sketch of the monferrato and turin hills. 1a: main northern apennine thrust fronts. 1b: geological and tectonical outline of the monferrato and torino hills with isobaths of the pliocene base in the saluzzo, asti and alessandria basins (south of the hills) and in the po foredeep basin (north of the hills). modified from dela pierre et al. (2003a). 47 evolution of the northernmost apennine front (piedmont, italy): ... 2. methods in order to achieve the results necessary to improve knowledge of the pliocene-pleistocene evolution of the monferrato front, in the present study is an analysis of the data available in the literature integrated by some new data from field surveys. for the cerrina valley, the bibliographic data are based on field surveys, studies on artificial outcrops and stratigraphies of cores taken in some boreholes, on the fossil content, and on dating with the method of the racemization of the amino acids on the remains of vertebrates (giraudi, 1981; enel, 1984; dela pierre et al., 2003a;b; giraudi et al., 2003; siori & sala, 2007). new field surveys have been carried out in the stura riverbed. for the stratigraphy and tectonics of the pliocene and pleistocene sediments which form the po valley north of the monferrato, the data derive from literature (pieri & groppi, 1981; enel, 1984; cassano et al., 1986; bigi et al.,1990; giraudi, 2014) and from new surveys in the po riverbed. during the researches reported in enel (1977; 1984), in which the author of the present paper also collaborated, dozens of boreholes were drilled up to 200 m deep, trenches were dug and stratigraphic, micropaleontological and palynological analyses were carried out on the sediments. the chronology of the pliocene and early pleistocene sediments is also supported by palaeomagnetic fig. 2 geological map showing the main tectonic structures of the central monferrato hills and of the buried monferrato underlying a thin cover of quaternary sediments. the figure shows only the thrust fronts, faults and flexures affecting the buried monferrato during the pleistocene. in fig. 2a and 2b, all the buried structures according to enel (1984) and bigi et al. (1990) are drawn. analysis on marine, transitional and continental sediments (enel, 1977). some tilted bedding plains recognized in cores, lacking any precise orientation, have been used for the only useful datum, that is the value of the dip. the correlation between stratigraphic sequences in several drillings and the presence in marine and continental sedimentary units of less tilted deposits overlying more tilted ones, have been used in order to evidence some unconformities. the difference between the stratigraphy of the sediments sampled in alignments of boreholes drilled for just a few tens of metres or, in one case, a few metres apart allowed the presence to be inferred of the lucedio and cavourrina faults up to a few metres below ground level (enel, 1977; 1984). also, the direction and the slip of the two faults was evaluated thanks to the alignments of boreholes, without knowing, however, the true dip of the fault planes. many fault planes have been observed in the cored sediments, but it should be noted that the real dip of the planes remains unknown: the only reliable datum is the value of their tilt. it has been assumed that at least a part of the fault planes dipping <30° indicate the presence of thrust faults. as a matter of fact, among the various fault planes, those dipping <30° were lying exclusively in correspondence to, or in areas close to, the thrust fronts reported by geophysical surveys. 3. the pliocene-pleistocene sedimentary sequence of the plain north of the thrust front and its phases of deformation the southernmost portion of the vercelli plain is made up of quaternary sediments, less than 20 m thick, covering tertiary marine sediments. the latter, similar to those outcropping in the hills that limit the plain to the south, are defined as buried monferrato. compared to the plain which extends north of the turin hills and monferrato, the vercelli plain is peculiar. in fact the southern vercelli plain is formed by the isolated trino hill (rit) and by a series of terraces that are not present elsewhere (giraudi, 2014) and the buried monferrato goes much further north than in the western and eastern plains. the buried monferrato ends at the thrust front. the tectonic structures that displace the buried monferrato sediments are known thanks to geophysical and geological studies based on wells and boreholes drilled as part of oil exploration (bonsignore et al.,1969, pieri & groppi, 1981; cassano et al., 1986) and seismotectonic studies (enel, 1977; 1984). the later structural model of italy (bigi et al., 1990) suggested a new interpretation of the same structures. all the papers related to the area of the buried monferrato show the presence of a series of thrust fronts, but with various and important differences. bonsignore et al. (1969) and enel (1984) assume thrust fronts with characteristics that are quite similar. in enel (1984) a first, northernmost, front was highlighted (fig. 2a), active until the initial portion of the middle pliocene, and a second front, very close to the first, dated to the late plioceneearly pleistocene. south of this there are three other smaller fronts, whose activity it is difficult to assess. also bigi et al. (1990) indicate the presence of a large northernmost front (fig. 2b) on which a second front partially overlaps restricted to the area north of trino. bigi et al. (1990) also show other thrust fronts that are less extensive and having different direction. the two interpretations of the tectonic structures of the buried monferrato appear quite different. overall, only the northernmost front and part of the second front located north of the isolated trino hill (rit) are accepted by all authors. however, the data obtained from the boreholes (enel, 1977; 1984) show that the pleistocene tectonic activity is certainly documented only along two stretches of the thrust fronts indicated by the geophysical research, which are known as the lucedio and cavourrina faults, which reach near ground level, being covered by only few metres of middle pleistocene fluvioglacial sediments. therefore in the present paper only the tectonic deformations along the lucedio and cavourrina faults and the northernmost thrust front will be discussed. the interpretation of the geological and stratigraphic data have instead enabled giraudi (2014) to assume that in the crescentino and morano po areas, on the surface projection of the thrust front highlighted by geophysical studies, faults with any great throw may not be present, and the sediments would be deformed mostly by flexures, at least, to a depth of about 200 m below the ground level (fig. 2; 3). the sediments of some cores contain fault planes (enel, 1977;1984). the dip of the planes is variable, from near-vertical to near horizontal. at times the striae suggest strike slip activity. tertiary layers having cataclastic structures have sometimes been observed. the fault planes are affecting both tertiary and quaternary (early pleistocene) sediments (fig. 4a). only in one case is a fault at the contact between sediments of different stratigraphic units. as regards the tilt of the sediments cored in the boreholes, it is observed that the most tilted ones are located near the buried fronts (fig. 4b). near the thrust front also the stratigraphic unconformities are much more evident. to the north of the thrust front is the po (foredeep) basin consisting of thick fluvio-lacustrine, fluvial and fluvioglacial sediments covering mainly slightly deformed quaternary and tertiary marine deposits (fig. 3). in the po basin, thanks to the subsidence, documented during the pliocene and the pleistocene (pieri & groppi, 1981; cassano et al., 1986; dela pierre et al., 1994), sedimentation has prevailed over the erosion. it follows that the sedimentary sequence filling the po basin provides more continuous data and allows for a more reliable interpretation of the geological evolution. 3.1. the po basin sediments the po basin corresponds to the northernmost part of the study area and is filled by continental quaternary sediments overlapping gently folded quaternary and tertiary marine deposits (pieri & groppi, 1981; enel, 1984; cassano et al., 1986). because the subsurface data discussed in the present paper were collected during the enel seismotectonic studies, the chronology of the sediments is the 48 giraudi c. fig. 3 stratigraphic sections through the buried monferrato and the po plain foredeep basin in the southern vercelli plain. 49 evolution of the northernmost apennine front (piedmont, italy): ... same as that adopted in enel (1984), based on micropalaeontological, pollen and palaeomagnetic analyses. the geological sections shown in fig. 3 were obtained using the stratigraphies of the enel boreholes. pliocene and pleistocene marine sediments, sampled with boreholes in the area of the po basin north of the front lying between crescentino and trino, are represented by the following stratigraphic units (fig. 3 and 5): unit m1. this consists of a monotone sequence of silt locally interbedded with thin sandy layers. according to the malacofauna content, the unit has been dated from lower to middle-upper pliocene (enel, 1977; 1984). the sedimentary environment varies from lower neritic, at the bottom of the unit, to upper neritic, at the top. the palaeomagnetic analyses (enel, 1977) have revealed that the top of the unit presents a reverse polarity, and is therefore attributable to the chron matuyama with a consequent age of less than 2.58 ma. while at the time of the studies published in enel (1977; 1984) the bottom of the chron matuyama was considered late pliocene, currently the same period is considered the base of the pleistocene (gibbard et al., 2010), and it follows that the pliocenepleistocene boundary lies in the middle-upper unit m1. unit m2. this consists mainly of sands with interbedded silt horizons and, sporadically, gravelly sand, showing a littoral environment (enel, 1977; 1984). at the top of the unit, some horizons with reworked fauna may indicate the presence of continental facies. the unit m2 appears in continuity of sedimentation on the m1. unit m3. this is formed mainly of sand, generally in centimetres thick laminae which, at their bottom are coarser and interbedded with fine beds of gravelly sand, while upwards they are interbedded with sandy -silt. the facies of the sediments and the fossil content indicate a gradual shift from a littoral marine environment to a brackish water environment (enel, 1977; 1984). the unit m3 is transgressive on the units m1 and m2. the stratigraphic units evidenced by the continental sediments of the po basin are the following (fig. 3, 4): unit abp. this is made up mainly of silt, containing plant remains and wood, and rarely of sand and gravelly sand. peat horizons are common among silt and sand layers. the thickness ranges from a few metres to more than 200 m in areas far from the monferrato thrust front. the palaeomagnetic analysis of the sedimentary sequence indicated that a reverse polarity prevails although there are intervals with normal polarity (enel, 1977). since the unit overlies sediments dated to the chron matuyama (enel, 1984), and older than about 870 ka bp (giraudi, 2014), the sedimentation of the unit abp occurred during the early pleistocene. along a belt lying near the thrust fronts, the sediments of this unit are tilted up to 35-40°, but the tilt value becomes lower north of the fronts (fig. 4b). the only excep fig. 4 tectonic structures and sediment’s deformations below the vercelli plain. 4afault and flexures. 4btilt of the sediments. 50 giraudi c. tion is a small area ne of the san grisante terrace (tsg in fig. 4b), at a distance of a few kilometres from the thrust front. in this area the sediments show an anomalous tilt even though there are no known quaternary tectonic structure that could have produced the tilting. in some areas, the presence of a greater number of boreholes showed that the unit abp includes sediments of two sedimentary facies separated by an unconformity: the lower part (labp) is made up of clayey silt and sandy silt, with some sandy and, less frequently, sandy gravelly horizons. the sedimentary facies is mainly lacustrine and alluvial. at the top of the labp sediments, the pollen content suggests that the sedimentation occurred during a cold period (enel, 1977). the magnetization of the sediments shows a mainly reverse polarity, with two short periods of normal polarity (possibly corresponding to the sub-chron reunion i and ii). according to enel (1977) the sediments of the lower abp unit should be dated to about 2 ma, and therefore to the gelasian. the top of the unit abp (uabp in fig. 5) differs from the bottom by the greater abundance of sandy and gravelly horizons of fluvial environment. the pollen content suggests that the climate was cooler than before. the magnetization of the sediments shows mainly reverse polarity. according to enel (1977), the sediments of the upper abp unit are less than 1.8 ma old. the top of the abp unit, therefore is calabrian in age. the less tilted uabp sediments lie unconformably on the more tilted labp ones (fig. 4b). in the area of crescentino, some sandy-gravel levels found towards the top of the abp unit, at about 40-60 m below ground level, contain brown flint and violet jasper pebbles with a diametre of 7-8 cm. the pebbles of flint and violet jasper were never found in the other boreholes but were present in alluvial gravelly sands of the cerrina valley, described in giraudi (1981) and giraudi et al. (2003), sedimented by a stream, probably alpine in origin, during the early pleistocene (see below). the whole sedimentary sequence that forms the unit abp is displaced by the lucedio and cavourrina faults (fig. 3). moreover, both near such faults and south and south-east of crescentino (fig. 4a), the cored sediments are cut by several fault planes dipping even less than 30°. north of the lucedio fault, the amount of fault planes is inversely proportional to the distance from the thrust fronts. therefore, the presence of several fault planes both sw and ne of the st. grisante terrace (tsg of fig. 4a) is surprising at a distance of some kilometres from the thrust front, to which the faults do not seem connected. unit fa consists mainly of sandy gravel much coarser than the older sediments, fluvioglacial and alluvial in origin, that form a succession of sedimentary bodies and terraces dated from mis 22 to the present (giraudi, 2014). north of the thrust fronts, the base of the fa unit appears deformed by subsidence, while south of the front the sediments are displaced by the lucedio and cavourrina faults. 3.2. sediment deformation and thrust front activity the geological sections, drawn up on the basis of the stratigraphic data (fig. 3), indicate that the area of the basin north of the main thrust fronts was subsiding during the sedimentation of the abp unit and of the older part of the fa unit. the pleistocene sediments (including the oldest part of those in the fa unit) are strongly displaced by the lucedio and cavourrina faults (giraudi, 2014). the faults were certainly active during or after the sedimentation of the lower part of the abp unit (phase f1), and then in the course of sedimentation of the upper part of the same unit (phase f2). in the area between the thrust front and the rit, also the early pleistocene tilted continental sediments of the unit abp have undergone two phases of deformation. the first one (d1), acted before the sedimentation of the upper abp unit, and in fact the sediments of the lower abp unit are more tilted than the top of the same unit. the second deformation phase (d2) was simultaneous with and/or subsequent to the sedimentation of the upper abp unit and caused the tilting of the sediments, the displacements along the lucedio and cavourrina faults and the development of low-angle faults. along the lucedio fault tectonic contact took place between gelasian marine sediments and calabrian continental ones. according to the sedimentary facies, the phases of deformation affecting the upper abp unit in the period before 0.87 ma, certainly related to compressive tectonic, produced no significant changes in the landscape of the po basin. in the period following 0.87 ma, while the compression phase was still in progress, the area north of the monferrato front was subsiding and filled by fluvioglacial and fluvial sediments, but south of the front alternating phases of sedimentation and erosion ocfig. 5 stratigraphic sketch of the plio-pleistocene marine and continental sediments drilled in the po foredeep basin just north of the monferrato thrust front. 51 evolution of the northernmost apennine front (piedmont, italy): ... curred and the oldest terraces of the rit were shaped. depending on the age of the sediments that seal the faults of lucedio and cavourrina, the thrust fronts would have been active up to about 400 ka bp or, in any case, in a period not more recent than about 280 ka bp (giraudi, 2014). 4. the faults displacing the tertiary sediments outcropping in the po riverbed the tertiary marine sediments that form the monferrato hills and the buried monferrato outcrop extensively in the po riverbed, and in particular in the stretch north of the cerrina valley, but have never been adequately studied in terms of stratigraphy and structural setting. some brief remarks on the outcrops of the tertiary substrate in the river are found in sacco (1889), lovari (1912), lupano (1912), beatrizzotti et al. (1964), and in dela pierre et al. (2003 a;b). a small-scale map indicating the tertiary sediments outcropping in the po riverbed and their presence in the buried monferrato, below a thin quaternary cover, is also reported in giraudi (2014) together with the presence of the crescentino fault and the salera line. a description of the outcropping bedrock is outside the scope of this paper; however, during the field surveys faults were observed that may have played a role in linking the cerrina valley syncline with the thrust fronts. the field surveys were carried out mostly n and nw of the head of the valley gaminella-cerrina basin fig. 6 seismic sections trough the monferrato thrust front of the trino isolated hill and east of trino. the sections, modified from enel (1984), reports also the stratigraphy and chronology of the sedimentary units discussed in the text, and atop of the sections are reported stratigraphic and tectonic data obtained studying cores taken from boreholes. 52 giraudi c. the difference among the structures evidenced in the sections po1-3 and tr3 may be due to the presence of the cavourrina fault-trino deformation zone, and the faults lying behind the thrust front in the po1-3 section, could be linked to the salera line, assuming that one of the faults forming the line was trending nne -ssw, like some faults observed in the po riverbed (fig. 4a). the cavourrina fault corresponds to a thrust front and it is expected that the front is bounded by ramps. the fontanetto and trino deformation zones could be the ramps. in the sections tr3 the cavourrina and lucedio faults dipping towards the north seem in contradiction with the thrust fronts dipping south. the resolution of the seismic sections does not indicate the trend of the structures in the interval between the ground level and a deep well below that reached by the boreholes and therefore the connection between the surface and deep faults is not known. the different dip of the faults could be due to the overturning of the thrust fault planes that show a “normal” sense of displacement towards the surface. a similar case is shown in michetti et al. (2012) in a scheme based on the novazzano structure, in the central po plain. 6. the lower cerrina valley the lower cerrina valley (the terminal portion of the stura stream basin) and the gaminella stream valley (fig. 2), its north-western tributary, are situated in the monferrato hills, south of the thrust fronts corresponding to the lucedio and cavourrina faults. the lower cerrina valley shows a number of geological and morphological peculiarities. among the geological peculiarities we can note the following. a part of the hills inside the lower cerrina valley consists of messinian sediments that are isolated among older tertiary ones and are not covered by pliocene marine deposits (montrasio et al., 1969; dela pierre et al., 2003a;b). this is a unique case in the monferrato and turin hills, where messinian sediments outcrop only at the edge of the hills and are always covered by pliocene deposits. in the cerrina valley, the only case in the northern monferrato, there are lake and river sediments dated at the early and middle pleistocene, reaching approximately 30 m in thickness (fig. 7), isolated among tertiary sediments. the river sediments are formed by sandy gravel composed also of pebbles of alpine origin, deposited by a river (nw river) that reached the gaminella-cerrina valley through the gabiano threshold (giraudi, 1981; carraro et al., 1995; giraudi et al., 2003; dela pierre et al., 2003a;b). the morphological peculiarities are the following (fig. 7): the gaminella-cerrina valley is abnormally shaped compared with the surrounding valleys, running from nw to se, then w-e, and finally approximately n-s. the valley from gabiano to pontestura appears too broad compared with the streams running through it. and in the area of the confluence of the cerrina valley in the po plain. the fault planes identified affect layers deformed by folds, which could prove greater tectonic complexity than that hypothesized only on the basis of the few exposures in the adjacent hills. from the area east of the crescentino fault (fig. 4a) to the area north of gabiano, there are several faults that displace the tertiary sediments, oriented approximately ns, nne-ssw and nesw. the faults lie on the theoretical southern extension of the branch of the nne-ssw cavourrina fault. even in the bed of the po, east of camino, on the theoretical southern prosecution of the eastern branch of the same fault, running approximately n-s, there are fault planes that are approximately n-s, along with others from ene to wsw, that do not correspond with the fault observed by dela pierre et al. (2003) in the hills. the above reported new data allow some interpretations that can complete the tectonic framework. the presence of n-s striking faults east of camino and nnessw faults north of gabiano suggests that the cavourrina fault is formed by the short thrust front immediately to the n of the trino isolated hill and by two ramps (fig. 4a) reaching, at least, the edge of the hills. because in the po bed there is a series of parallel faults, lying in areas hundreds of metres wide, probably the ramps correspond to deformation zones (fontanetto po deformation zone, to the west, and trino deformation zone, to the east). the new data on the presence of deformation zones, located in the theoretical prosecution of the two branches of the cavourrina fault, suggest that the fault is a complex tectonic structure, active for a long period, which could have played a role in the post-messinian uplift of the cerrina valley and of the buried monferrato, where there are no pliocene marine sediments. 5. the seismic sections: the cavourrina and lucedio faults and the buried thrust fronts the comparison between the data from boreholes and two seismic sections reported in enel (1984) helps to understand the relationships between the cavourrina and lucedio faults and the buried thrust fronts, and corroborates the hypothesis of the presence of the trino deformation zone and of the salera line. the seismic section tr3 (fig. 4a) and its comparison with data from the boreholes (fig. 6) suggests that the cavourrina fault lies exactly on a buried thrust front. the lucedio fault lies a few hundred metres from a northernmost buried thrust front. the two faults dip towards the north while the thrust fronts dip south. the section po1-3, interesting the area east of the cavourrina fault-trino deformation zone, shows quite different tectonic features, with the thrust fronts covered by thick marine and continental sediments, and absence of faults reaching nearly the ground level. moreover, back of the thrust fronts, a fault produced the subsidence of the southernmost area, and the throw of another fault is uncertain. the comparison between the two sections allows for some interpretations. 53 evolution of the northernmost apennine front (piedmont, italy): ... in the stretch oriented w-e, the valley shows a clear morphological asymmetry: the northern slope dips gently and in some places is formed by a series of five terraces, while the southern slope is very steep and there is only a discontinuous low terrace. the differences between the geological and geomorphological features of the lower cerrina valley and the surrounding hills and those of the other monferrato hills must have been produced by geological evolution. the hypothesis that the valley is very broad because it was shaped by the nw river, which had more energy than the streams currently present, does not appear able to explain all the peculiar characteristics of the cerrina valley. 6.1 considerations on the peculiarity of the marine succession the peculiarity of the tertiary marine succession of the cerrina valley, described above, has never been taken into account. no author has discussed the causes of the presence of messinian sediments isolated among older ones and not covered by pliocene marine deposits. fig. 7 quaternary sediments outcropping in the gaminella/low cerrina valley, alluvial terraces and location of the quarries studied (7a). 7b: scheme of the distribution of the alluvial units a, b, c, the possible bed of the nw river, and area of diversion of the river northwest of the gabiano threshold. 54 giraudi c. a discussion on this point is beyond the scope of this paper, but the presence of messinian sediments suggests that the area, open to the sea until the messinian, emerged during the pliocene, like other areas of the monferrato (bonsignore et al., 1969; dela pierre et al., 2003a;b). probably the connection with the sea occurred in the area near the south-eastern end of the syncline oriented nw-se, located sw of ozzano (fig. 2). the syncline continues outside the area represented in fig. 2. at the cerrina valley divide, the axial zone is made up of tortonian sediments, but, just to the east, the messinian sediments outcrop again. although covered by pliocene marine deposits, as in the whole area of the monferrato and turin hills. 6.2. the lower cerrina valley: site setting and stratigraphy the gaminella-cerrina valley (from now on called the lower cerrina valley), in the stretch between gabiano and pontestura, was carved between hills reaching altitudes of up to just over 400 m asl, and ends up in the po valley at an altitude of about 120 m asl. its catchment basin extends outside the study area towards the southwest (the stura stream) and south (the colobrio stream, a tributary of the stura). the lower cerrina valley mainly corresponds to the axis of a syncline having a peculiar direction. the axis is directed first from nw to se, then w-e, and finally approximately n-s (figure 2): to the west, it crosses tectonic structures having axes mainly oriented from wsw to ene, while to the east it crosses also nw-se structures. just se of pontestura, the axis of the valley continues in a s-n direction, while the axis of the syncline bends sharply towards nw. near the confluence of the stura stream in the po river, the valley floor is carved in the sediments of the casale monferrato formation (eocene) (fig. 2), as shown by the sediment outcrops observed in the bed of the po and the stura rivers during the field surveys. with regard to the quaternary deposits, the presence of fluvial sediments deposited by the nw river (giraudi, 1981; enel, 1984; carraro et al., 1995; giraudi et al., 2003; dela pierre et al., 2003a;b) indicates that the valley was, for a certain period, open towards nw. according to the literature, east of the village of castagnone (fig. 7), the river probably continued to the east or se (enel, 1984; carraro et al., 1995; dela pierre et al. 2003a;b; giraudi, 2015a) following roughly along the axis of a post-messinian syncline located sw of ozzano, and finally reaching the lower rotaldo valley. according to giraudi et al (2003) the hilly area of gabiano and camino, north of the left side of the cerrina valley, was uplifted in the lower and middle pleistocene and, according to dela pierre et al. (2003a;b), the uplift would have been related to the northward migration of the monferrato thrust front. the fluvial deposits, deformed by tectonics and syn -sedimentary landslides, occur only on the left side of the valley and are dated at the early and middle pleistocene (giraudi, 1981; dela pierre et al., 2003a;b; giraudi et al., 2003). also on the left side (giraudi et al., 2003), the slope of the valley is shaped by a series of terraces (fig. 7a) while in the rest of the stura stream catchment only in some places there are remnants of a low terrace at the base of the slopes and the valley bottom is made up of thin layers of recent alluvial sediments. in the literature, the anomalous width of the gaminella-cerrina valley has been attributed to the erosional activity of the high energy nw river, potentially stronger than that produced by the small hill streams. however, the anomalous size of the valley continues also in the stretch heading north, up to pontestura, where there is no evidence of the presence of a high energy river. it is therefore necessary to review and discuss the stratigraphic data and the phases of tectonic deformation of the sediments in order to characterize the tectonic-sedimentary evolution in the detail needed to identify any elements of correlation with events recorded near the buried monferrato front. in this chapter the stratigraphic data collected (fig. 2; 7; 8) at a place near castellino and in two quarries, now abandoned (cascina nuova quarry: giraudi et al., 2003; peratore quarry: giraudi, 1981) will be examined in detail, discussed and compared. fig. 8 stratigraphy of the castellino (a) and cascina nuova (b) sites. a) legend: 1 sand and fine gravel interbedded with clayey silt, 2 reddish colluvial silt; 3 tertiary sandstones; 4 syn-sedimentary fault. b) legend: 1 aeolian unit; 2 gravelly sand of alluvial unit c; 2a sandy silt and silt of alluvial unit c; 3 sandy gravel and silty sand of alluvial unit a; 3a unconsolidated sand of alluvial unit a; 3b calcareous crust of alluvial unit a; 3c dark clay of the alluvial unit a; 4 calcareous crust of the lower complex; 5 gravelly sand and silty clay with patches of a colluviated soil of the lower complex; 6 partially cemented clayey silt of the lower complex; 7 lacustrine unit; 7a calcareous crust interbedded with the lacustrine unit. 55 evolution of the northernmost apennine front (piedmont, italy): ... 6.2.1. the castellino alluvial sediments north of castellino (fig. 2) on the right side of the valley of the colobrio stream, about 250 m asl, a small exposure (a few hundred m2) of continental uncemented sediments was present. the deposit was discovered by the writer in the early 80's thanks to an ephemeral outcrop (fig. 8a) and is described in enel (1984). it is formed of sand and fine gravel interbedded with grey, compact clayey silt. in the north-west, reddish silt is interfingered. gravelly sands are fluvial in origin and their lithological composition (the pebbles are mainly of marl, greenstone and cemented diatomite) clearly indicates that the clasts derive from tertiary sediments forming the bedrock. the reddish silt is colluvial. the pebbles of diatomite most likely derive from the “diatomitic member” of the “marne a pteropodi” formation (aquitanian ppburdigalian pp, according to dela pierre et al., 2003a;b) outcropping a few km west of the site. the sediments, observed only for a thickness of approximately 5 m, are tilted about 10° towards the nw, and lie unconformably on tertiary marine sediments, having a clear-cut contact with sub-vertical strata of sandstones. the base of the fluvial sediment was not exposed but must have been at an altitude of al least 50 m above the base of the cerrina valley gelasian sediments (see below). the sediments are also displaced by a small synsedimentary fault, whose plane dips about 60° towards the se, sealed by the gravelly sands that form the top of the exposure. the ne-sw direction of the fault plane coincides with that of a fault hypothesized by dela pierre et al. (2003a;b) in the adjacent valley bottom of the colobrio stream. the palaeontological study of the sediments indicated the presence of an abundant reworked fauna of marine origin (enel, 1984). there are no data about the age of the sediments, but the presence of alluvial deposits at an altitude next to those of the highest hills of the area lying on the right slope of the colobrio valley allows us to assume that sedimentation took place in a period during which the drainage network was not yet very well developed. according to carraro et al. (1980) and dela pierre et al. (2003a;b) some parts of the monferrato emerged from the sea during the phase of intense tectonic deformations contemporary with the sedimentation of the marine pliocene succession. the syn-sedimentary fault and the tilt of the sediments suggest that the sedimentation occurred during a period characterized by tectonic activity. it is possible, therefore, that the alluvial sediments of castellino date back to the pliocene. 6.2.2. stratigraphy and deformations of the cascina nuova and peratore quarry sediments the sequence described below refers to the cascina nuova (fig. 7a; 8b) and peratore quarries (fig. 7a, 9) and to an ephemeral small quarry, called w quarry (fig. 9). the sediments on which the studies have been based were outcropping or were exposed digging trenches. some boreholes were drilled in order to reach the bottom of the continental sediments and the bedrock. only the stratigraphic data obtained from boreholes drilled in the peratore quarry and surveying the exposures in the w quarry, were not reported in literature. the sediments of the cascina nuova and peratore quarries contained vertebrate remnants and microtine teeth (giraudi, 1981; giraudi, 1983; enel, 1984; giraudi et al., 2003; siori & sala, 2007) and have been fig. 9 stratigraphic sections through the peratore and w quarries 56 giraudi c. analyzed in order to detect their magnetic polarity (enel, 1984; giraudi et al., 2003). some fossil teeth found in the peratore quarry were dated with the method of amino acids racemization (enel, 1984) and some of these datings were also reported in dela pierre et al. (2003a;b). the stratigraphy of the cascina nuova quarry was discussed in giraudi et al. (2003) while that of cava peratore (drawn in fig. 9) was obtained by updating the section reported by giraudi (1981), which also included the deepest part of the stratigraphic succession, no longer visible after the year 1980, with the data obtained through special excavations during the enel (1984) studies. the bedrock the bedrock underlying the continental sediments of the cascina nuova and peratore quarries, according to dela pierre et al. (2003a;b), consists of marine sediments (sant'agata fossil marls) tortonian in age. however, some boreholes drilled inside the peratore quarry, never discussed before, and some ephemeral exposures observed in the 1980s made it possible to detect the presence of other upper miocene sediments. unit avc grey-green compact silt, drilled for 8 m in the peratore quarry. the microscopic observation of the sediments revealed concretions of white clay and gypsum, rounded fragments of gypsum covered with a patina of alteration, and concretions of pyrite. depending on the fauna content (studied by m. sampò in the year 1984), the sedimentary environment is a marine external platform (intermittent anaerobic); the age of the sediments is lower messinian. unit bvc grey to dark grey compact silt, up to 3 m thick, sampled by means of boreholes in the peratore quarry, but observed also in ephemeral exposures at cascina nuova and east of peratore quarry. the sediments lie unconformably on the early messinian avc unit. observation under the microscope showed clasts of gypsum, transparent and otherwise, pyrite concretions and rare glauconite grains. the microfauna, mostly reworked (studied by m. sampò in the year 1984), suggests that the sediments pertain to the upper messinian post-evaporitic “strati a congerie” (conglomerati di cassano spinola formation, in bonsignore et al., 1969). neither of the two units (abc; bvc) corresponds to the valle versa chaotic complex, upper messinian in age, outcropping about 1 km to the west and south of the described area: at the base of the bvc unit, then, there is a hiatus, probably corresponding to the discontinuity surface d6 (younger than the chaotic complex), reported in the adjacent areas by dela pierre et al. (2003a;b). even in the tertiary piedmont basin the last messinian discontinuity separates the valle versa chaotic complex from the “conglomerati di cassano spinola” formation (clari et al., 2008). the lacustrine, alluvial and aeolian sediments the post-messinian sedimentary sequence is best preserved and thickest (20-30 m) between cascina nuova and the area east of peratore quarry. west of cascina nuova, however, the sediments are discontinuous and only a few metres thick. lacustrine unit: this consists of clay and silt sedimented in a low energy environment, lake or marsh. the lowest levels exposed consist of homogeneous silty clay, little or poorly bedded, fissured, and with a patina of iron oxide, containing an intercalation of silt with whitish calcareous concretions. the sediments of the top of the unit are formed of silty clay, greywhitish and yellowish, finely laminated, fissured and with fe oxide patinas in the cracks. the sediments sometimes contain fragments of wood completely mineralized, and are interbedded with thin and discontinuous calcareous crusts and horizons containing calcareous concretions, and can be strongly cemented. about 2.5 m below the top of the unit, associated with strongly cemented silty clay, a fragment of wood was found, transformed into limonite by diagenetic processes. since this is a fragment of considerable size (up to 60 cm long, 25 cm wide and 810 cm thick) and of considerable weight, intercalated between deposits of low energy with plane-parallel fine lamination, it is presumed that diagenesis of the wood took place after sedimentation. among the silty clays of the top of the unit there is a small angular inconformity of about 2°. there are no direct data for the dating of the lacustrine units, but its stratigraphic position and the palaeomagnetic polarity of the sediments indicate a chronological framework. the palaeomagnetic analysis showed that the polarity of the sediments sampled in the upper half of the unit is normal (giraudi et al., 2003). the cava peratore boreholes show that the lacustrine unit lies unconformably on the post-evaporitic upper messinian sediments. the unconformity excludes the chronological attribution of this unit to the upper messinian. lower complex: up to 70-85 cm thick, is exclusively colluvial and patchily preserved in the area and overlies the lacustrine unit. it consists of clayey, massive, light to dark-grey, consolidated silt, up to 40 cm thick, and grey sand, gravel and silty clay, with patches of colluviated soils coloured 2.5 yr of the munsell soil color chart (mscc), up to 20-30 cm thick; a pedogenetic calcareous crust, more or less continuous, up to 10-15 cm thick, occurs on the top of the layer. the colluvial lower complex is unconformity-finished and most likely to be considered much older than the following alluvial unit. according to the palaeomagnetic analysis, the polarity of the sediments is normal (giraudi et al., 2003). the emplacement of the colluvium has not produced a clear erosion surface at the top of the lacustrine units, but the clear-cut contact between the two units suggests the presence of a paraconformity. in the peratore quarry, the lower complex has been found only in the extreme northern portion of the quarry (fig. 9). there are no direct date for the chronology of the unit, but the stratigraphic position and the magnetic polarity suggest that the lower complex was 57 evolution of the northernmost apennine front (piedmont, italy): ... formed still in the course of the same sub-chron during which the lacustrine unit was sedimented. alluvial unit a and chaotic complex: up to 10 m thick, lies unconformably on the lacustrine unit and lower complex. in the cascina nuova quarry; it consists of yellowish-grey sand and gravel, massive or poorly stratified yellowish-grey silt and sandy silt embedding carbonate concretions, and yellowish-grey unconsolidated sand with thin and discontinuous calcrete horizons. unconsolidated sandy bodies are interbedded with silty and sandy silty layers. a heterotopic facies of gravelly sand and dark clay occurs near the top of the sandy silty sediments. for their lithological composition (discussed in giraudi, 1981; carraro et al., 1995; giraudi et al., 2003; dela pierre et al., 2003 a;b) showing the presence of pebbles of rocks outcropping outside the t. stura catchment, including violet jasper and flint with brown patina, the gravel must have been deposited by the nw river having its catchment nw of the gaminella valley. alluvial unit a contains the remains of galerian macrofauna associated with early biharian (rodent age) microtine vole teeth. the faunal content and the normal magnetic polarity enable these sediments to be dated in the sub-chron jaramillo (giraudi et al., 2003; siori & sala, 2007), dated 1.07-0.99 ma, namely in the marine isotope stages (mis) ranging from 31 to 28. in the peratore quarry, in the same stratigraphic position as alluvial unit a, a chaotic complex is present, formed by two members consisting of sediments strongly affected by plastic deformations and displaced by small faults and rotational surfaces. the lower member is formed by silt interbedded with sandy-silt, and layers of sand, and more frequently gravelly sand. the latter are made up almost exclusively of clasts deposited by the nw river. the facies and lithology of the gravelly-sandy sediments are similar to those of the alluvial unit a of cascina nuova. some silt layers are characterized by the presence of scattered pebbles from outside the valley and clayey-marl of local origin, showing a mudsupported structure. the upper member consists of unstratified whitish clay that includes sets of strata formed by laminated silt and clay with horizons of calcareous concretions, clearly corresponding to the sediments of the lacustrine unit. the chaotic complex contains fauna indicating (giraudi et al., 2003) a generic galerian (macro) mammal age (sensu gliozzi et al., 1997) and reworked marine fossils. the sediments that form the chaotic complex have a normal magnetic polarity (enel, 1984), and are older than alluvial unit b, dated at the beginning of the middle pleistocene (see below). the sedimentation of the gravelly sand and most of the deformations thus occurred during the sub-chron jaramillo. alluvial unit b: the sediments that form the unit are mostly sandy and gravelly, and have a facies similar to that of the alluvial sediments of unit a. the lithology of the gravel indicates the prevalence of clasts from outside the valley. among the alluvial sediments some large blocks of clayey silts may be present similar to the tertiary sediments forming the hills around the peratore quarry. the presence of such blocks is due to the sliding of masses of bedrock into the sedimentation basin. the alluvial sediments of unit b lie on an erosion surface, dipping s and se, cutting the top of alluvial unit a. in the sediments of unit b some fossils remnant have been found (giraudi, 1981; enel, 1984; giraudi et al., 2003), indicating a generic galerian (macro) mammal age (sensu gliozzi et al., 1997). study of the racemization of the amino acids in three fragments of teeth found among the sediments indicated ages of 820-780, 750-706, 730-690 ka bp (enel, 1984; dela pierre et al., 2003 a;b) which are consistent with the stratigraphic position of the fossils analyzed. at the top of alluvial unit b are clayey silts, up 1.5-2 m thick, lying in a palaeo-channel. these sediments are palustrine in origin, and contained the remains of elephas indet. (giraudi, 1983). paleomagnetism (enel, 1984), indicating that alluvial unit b is of normal polarity. according to the fauna, the dating and the normal polarity of the sediments, alluvial unit b must have sedimented during the chon brunhes, especially in the oldest part of the middle pleistocene, corresponding to mis 20, 19, and 18. the erosion surface lying at the base of alluvial unit b might then have produced the erosion of sediments possible dated at mis 27-21, corresponding to a chronological interval of about 200 ka. some structures that displaced alluvial unit a and the chaotic complex also affect alluvial unit b. alluvial unit c: (4-5 m thick) has a sharp unconformity with the underlying one and starts with basal siltygravelly sand with diffused clay chips deriving from the erosion of the tertiary bedrock, followed upwards by sandy silt and silt with scant lenses of silty sand and clay. the gravel also contains pebbles from outside the cerrina valley, but the sediments, compared with older units, contain a higher amount of clasts of marl from the marine tertiary formations, and refig. 10 stratigraphic sketch of the upper miocene – middle (upper) pleistocene marine and continental sediments exposed in the cerrina valley. 58 giraudi c. worked marine fossils. the upper part of the unit (h' in fig. 9) shows a gradual decrease in grain size, from sandy silt, alluvial in origin, to clayey silt sedimented in a small lake or marsh. at the top of the unit is a reddish soil coloured 5yr 5/8 mscc. the fossil content is poor, represented by fragmentary teeth of a herbivorous indet. and some arvicolid incisor teeth (giraudi et al., 2003; siori & sala, 2007). a tooth fragment found among these sediments in the northern part of the peratore quarry, dated by the method of racemization of amino acids, indicated an age of between 570 and 600 ka bp (enel, 1984; dela pierre et al., 2003 a;b), corresponding to the intermediate part of mis 15. palaeomagnetic analyses (enel, 1984; giraudi et al., 2003) performed on the sediments at the bottom of alluvial unit c have indicated normal polarity. both in the peratore and w quarries, alluvial unit c overlies, via an erosion surface markedly dipping towards the se (section 2 in fig. 9), the oldest sediments and is displaced to the top by limited movements along structures that have already affected the older units or ones of new generation. alluvial unit d: this is a sequence of silts and sandy silts about 4 m thick (fig. 9) deposited by a low energy stream: at their top lies a reddish yellow soil, coloured 7.5yr 5/8 mscc. the sediments of this unit form the higher fluvial terrace observed in the cerrina valley (t1). aeolian unit: loess formed by aeolian silt, 70-80 cm thick. mousterian scattered lithic artifacts lie inside the deposit and therefore the loess can be dated at the late middle pleistocene or the upper pleistocene (mis 6 or mis 4-3). the soil developed on the loess is coloured 10 yr mscc. the stratigraphy of the tertiary and quaternary cerrina valley sediments described above is represented in fig. 10. the lacustrine unit and the chaotic complex of the alluvial unit a need to be discussed in order to reach a less approximate chronological framework or to establish their origin. the dating of the unconformity lying at the base of the lacustrine unit can be used for a tighter chronological framework of the unit. based on the stratigraphy of the monferrato sediments reported in dela pierre et al. (2003 a;b) the unconformity may correspond chronologically to the discontinuity surfaces d7 (early pliocene) or d8 (early pleistocene). however, it is unlikely that the unconformity corresponds to the discontinuity surface d7 because this discontinuity was observed only among pliocene marine sediments and is covered by marine deposits of the final stages of the foraminiferal zone fpl3 (ending around 4 ma). moreover, the bottom of the lacustrine unit lies at least 50 m below the bottom of the castellino alluvial sediments, probably dating back to the pliocene. it is likely, therefore, that the unconformity at the bottom of the lacustrine unit corresponds to the early pleistocene d8 discontinuity surface. the lake sediments must have been sedimented in a sub-crohn with normal polarity, older than jaramillo (see below), during the chron matuyama (reunion, dated ca. 2140 ka bp; olduvai, dated 1950-1770 ka bp; gilsa, dated ca. 1680 ka bp; cobb mountains, dated 1220-1240 ka bp). the thickness of the sediments and their syn-sedimentary deformation suggest that sedimentation took place over a fairly long time interval and seem to exclude the assignment of the unit to a chron or sub-chron of short duration. the lacustrine unit, therefore, could be dated at the longer sub-chron, i.e. olduvai. about the alluvial unit a, the presence of blocks of older sediments intercalated chaotically between fluviallacustrine deposits, the abundance of plastic or brittle deformations, and the presence of rotational shear surfaces affecting all the sediments of this unit, suggest that the chaotic complex was produced by the collapse of a set of layers of the lacustrine unit that caused the synsedimentary deformation of the fluvial-lacustrine deposits related to the nw river. also during the fluvial sedimentation even greater rotational movements occurred of the already deformed sediments, containing blocks, that had slipped earlier in the basin. 6.2.3. sediment deformation and tectonics the pleistocene deformation phases have been deduced from the dip of the sediments and the age of the plastic and brittle structures observed in the sediments. near cascina nuova, the dip of the units (fig. 8) progressively decreases from the bottom upwards but the inclinations are always southwards, that is towards the axis of the cerrina valley syncline. the lacustrine unit sediments have a bedding inclination of between 14° and 12°. during the sedimentation of the lacustrine unit (olduvai, 1,95-1,77 ma) a tilting of 2° occurred. the lower complex sediments dip about 12°. therefore between the top of the lacustrine unit and the end of the emplacement of the lower complex there was no deformation. the alluvial unit a sediments dip between 10° and 4°. therefore during the interval between the sedimentation of the lower complex (≥ 1,77 ma) and of the base of alluvial unit a (jaramillo, about 1 ma; mis 31-28) a tilting of 2° occurred, while during the sedimentation of alluvial unit a there was a tilting of 6°. during the sedimentation of alluvial unit a the emplacement also occurred of the chaotic complex exposed in the peratore quarry. the alluvial unit c sediments are nearly horizontal. in the period between the sedimentation of the preserved top of alluvial unit a (≥ 0.99 ma) and the base of alluvial unit c (about 0.6 ma; mis 15), namely during a period at least partially contemporaneous with an erosion phase and the sedimentation of alluvial unit b (about 0.78-0.7 ma), a tilting of 4° took place and, at the same time there was a less intense deformation of the peratore quarry sediments. the latest small deformations also affect alluvial unit c in the peratore quarry. the different lithological composition of the sedi 59 evolution of the northernmost apennine front (piedmont, italy): ... ments of alluvial units b and c suggests that the flow to the cerrina valley of the nw river ended after 0.7 and before 0.6 ma, that is, when the sediment deformation had diminished significantly. 6.3. tectonic interpretation one of the peculiarities of the cerrina valley listed above is the presence of the messinian sediments isolated between older formations, and not covered by marine pliocene, but by early pleistocene lake deposits. the late miocene-early pleistocene stratigraphy implies a post-messinian uplift of the area and then a post-pliocene phase of subsidence (phase s1) which produced the depression that, at least during part of the early pleistocene (1.95-1.77 ma), hosted a lake. the syn-sedimentary tilting, towards south and se, of the pleistocene deposits forming the side of the cerrina valley syncline implies the subsidence of the axial zone of the syncline. tectonic deformation began during the sedimentation of the lacustrine unit, but was more intense in the course of the sedimentation of alluvial unit a (fig. 11). it is possible that the subsidence of the syncline before the sedimentation of alluvial unit a (phase s2) created the topographical depression that triggered the diversion of the nw river into the cerrina valley. the strongest phase of subsidence in the syncline occurred during jaramillo (ca 1 ma). also, the orientation of structures described in the chaotic complex (dated at jaramillo) is compatible with a slip towards the south, that is, towards the axis of the syncline. the gravitational phenomena would have occurred, then, in correspondence of the strongest phase of subsidence of the cerrina valley syncline indicated by the tilt of the sediments. the deformation of the sediments continued, although less intense, at least up to about 730-690 ka bp, and then the syncline was active at least until that time. the few deformations that affected alluvial unit c, more recent than 600-570 ka bp, and the dip of the erosion surfaces may indicate that the eastern part of the syncline was the part that subsided most or that only that part was still active. according to giraudi (2014) in the final stretch of the cerrina valley a complex structure was present, the salera line, oriented approximately ns, crossing the monferrato thrust front, active also during the phases of compressive tectonics. the tectonic activity along the salera line could have caused the subsidence of the eastern part of the cerrina valley and, in the stretch where the valley bottom no longer coincides with the axis of the syncline, of the western portion of the casale monferrato formation. later, but before the loess sedimentation, the area was uplifted, and the uplift triggered a phase of incision of the valley (dela pierre et al., 2003 a;b; giraudi et al., 2003). this uplift was already recognized south of the cerrina valley by carraro and valpreda (1991). knowledge of the geological evolution can be completed by analyzing the main erosion surfaces observed between the pleistocene alluvial sediments. a first erosion surface, that produced a gap of about 200 ka in the sedimentary sequence, is interposed between alluvial units a (mis 31-28) and b (mis 20 -18). the erosion of the sediments should therefore have ceased just before mis 20. since then, according to the displacements of the deposits, during the sedimentation of the two alluvial units the style of the deformation has not changed, it can be assumed that the erosion surface was formed mainly as a result of hydrological changes of the nw river related to the climate during the mis 21 interglacial. the second erosion surface lies at the base of alluvial unit c, and it can be dated between 0.73-0.69 and 0.6-0.57 ma. this erosion surface, sloping towards s and se, developed during a period of tectonic change, which coincides with a phase of greater subsidence of the eastern part of the syncline. it is therefore likely that the erosion was triggered mainly by tectonics. in any case the erosion must have been active in a period, following mis 18, probably corresponding to the early mis 15. overall, the only period of tectonic stability older than the sedimentation of alluvial unit c (age <0.6-0.57 ma) corresponds to the sedimentation of the top of the lacustrine unit and the lower complex (about 1.77 ma). fig. 11 correlation between the tectonic activity in the monferrato thrust front and in the nearby foredeep basin, and in the cerrina valley syncline. 60 giraudi c. 7. correlations between the subsidence of the cerrina valley and the deformation along the monferrato thrust front behind the torino hills and the monferrato arcs, deep piggyback troughs developed in plio-quaternary times near saluzzo and alessandria. (dela pierre et al., 1995; irace et al., 2009) that is south-west and southeast of the arcs. according to giraudi (2015a) the subsidence of the northern alessandria basin continued at least until the upper middle pleistocene or early upper pleistocene, in correspondence with the activities of the thrust front lying north of the pomaro-montevalenza isolated hill. in the pliocene basin north of asti, exactly south of the central monferrato front and of the cerrina valley, the subsidence occurred only during the early pliocene and later the area underwent an uplift (dela pierre et al., 2003 a;b). the data reported in dela pierre et al. (1995) indicate that during the pliocene-pleistocene compressional phases there was subsidence both in the piggyback troughs and in the foredeep po basin. during the gelasian and calabrian, while north and sw and se of the front the subsidence continued, in the asti trough it had already ceased. according to dela pierre et al. (2003 a;b), the last stage of the evolution of the monferrato, north of the cerrina valley, would be connected to the northward migration of the thrust front on the po basin. it is therefore necessary to assume that a possible trough behind the most advanced northern monferrato thrust fronts active during the early and middle pleistocene must be placed in an area south of the front, but north in the asti basin: the only area that was subsiding during the same period was the cerrina valley syncline. the syncline probably expanded and deepened gradually as a result of extensional tectonics that occurred behind the thrust front migrating towards north. so, the anomalous width of the valley may not be due to the nw river erosion, but be a consequence of the expansion of the tectonic depression. if the hypothesis is correct, the deformation of the sediments and the unconformities related to the activity of the syncline can, then, be used to frame chronologically the migration towards the north of the monferrato thrust front. it follows that the subsidence of the cerrina valley must be synchronous with the deformation induced by the thrust front and with the phases of subsidence recorded by the sediments of the po basin (fig. 11). the comparison between the sedimentary sequences of the po basin and the cerrina valley shows that, at least from the pliocene to the beginning of the gelasian, the area of the cerrina valley was emerged, while north of the thrust fronts and in the asti basin there was marine sedimentation. pliocene marine sediments are also missing in the bedrock of the alluvial plain between the monferrato hills and the thrust front corresponding to the cavourrina fault (pieri & groppi, 1981; cassano et al., 1986; enel, 1977, 1984; giraudi, 2014). it is assumed that, at least from the late messinian, the evolution of the area limited to the north by the cavourrina fault and to the south by the cerrina valley has begun to differentiate with respect to other areas located near the monferrato-turin hill thrust front. the following subsidence of the cerrina valley, which allowed the establishment of a lake basin between 1.95 to 1.77 ma, started, probably, contemporary to the early stages of deformation of the gelasian sediments of the po basin, and continued until the time of fig. 12 surficial faults and flexures of the monferrato thrust fronts and possible transpressive faults and deformation zones linking the cerrina valley basin to the thrust fronts. 61 evolution of the northernmost apennine front (piedmont, italy): ... deformation of the base of the fluvial and lacustrine sediments of the unit abp. the period of tectonic stability which took place in the cerrina valley during the sedimentation of the top of the lacustrine unit and the lower complex (≥ 1.77 ma) may correspond chronologically to the development of the erosion surface that, in the po basin, occurred before the beginning of the sedimentation of the upper abp unit, dated around 1.8 ma. the stronger phase of subsidence of the cerrina valley syncline happened mainly between 1 and 0.7 ma and therefore it is contemporary to the tectonic phase that caused the displacement along the lucedio fault, the low-angle faults in the upper unit abp of the po basin and the tilt of the sediments. even the deformation of fluvial and fluvioglacial sediments dated between 870 and 400 ka (discussed by giraudi, 2014) is nearly contemporary with the displacements produced by sinsedimentary landslide involving deposits of the alluvial units b and c of the cerrina valley. the interpretation of the data suggests that, during the early pleistocene and the middle middle pleistocene, the subsidence and deformation of the sediments in the cerrina valley and in the po basin were mostly contemporary. the subsidence in the cerrina valley and the activity of the monferrato thrust front north of trino, therefore, seem connected. the hypothesis that the cerrina valley syncline could corresponds to a trough that developed behind the younger central monferrato thrust front, advanced by giraudi (2015b) seems likely, and probably the tectonic depression expanded as the front migrated northwards. the cerrina valley syncline would be connected to the thrust front by two complex tectonic structures, called by giraudi (2014) the salera line, to the east, and the crescentino fault, to the west (fig. 12). the two structures, covered by fluvial and fluvioglacial sediments of the plain, could correspond to the two strike-slip or transpressive faults, assumed by costa (2003), which would have acted as ramps for the movement of the lucedio fault thrust front. however the continuity between the cavourrina fault and the fontanetto po and trino deformation zones seems to suggest that also these tectonic structures were involved in the evolution of the cerrina valley syncline. 8. hypotheses on the catchment basin of the nw river the tectonic evolution outlined above provides some elements in order to discuss the catchment basin of the nw river entering the cerrina valley near gabiano. it is unlikely that the nw river corresponds to the dora baltea river (flowing from the aosta valley). in order to reach the cerrina valley, the dora baltea would have to cross the area in subsidence, then to cut through the uplifting thrust front. the river, most likely, flowed eastwards along the axis of the depression lying north of the front. in the plain north of the hills, the only alluvial sediments having a lithological composition fairly similar to that of the nw river were sampled in a borehole near crescentino (see above), 5 km west of the head of the gaminella-cerrina valley, and described near ostino (between monteu da po and brusasco), about 12 km west of the head of the valley, where sandy gravel (bonsignore et al, 1969; dela pierre et al., 2003 a;b) is poorly exposed on a terrace at the foot of the hill. the lithology of the clasts forming the ostino sandy gravel indicates (dela pierre et al., 2003 a;b) alpine (probably from the valleys of the orco and malone streams) and monferrato hills catchment basins. the first hypothesis, then, is that the nw river came from the alpine valleys lying sw of the aosta valley. some considerations on the evolution of the sedimentation in the po plain suggest another hypothesis. in the plains north of the monferrato hills (giraudi, 2014), but also elsewhere (muttoni et al., 2007), the sediments of the alpine rivers are coarser starting from mis 22 as a result of the stronger erosion caused by the expansion of the alpine glaciers. in contrast, among the alluvial sediments of the cerrina valley, older (alluvial unit a) and younger (alluvial unit b) than mis 22, there is no significant change in grain size. it can be assumed, therefore, that glaciers were absent in the nw river basin, which means that its catchment was outside the alps. the river basin could, therefore, be represented mainly by the northern monferrato. the nw river, lying mainly south of the thrust front, could have been the collector of the waters of the streams currently flowing into the po river between chivasso and crescentino. in this case, in the plain, the boundary between its basin and that of the alpine rivers, was uncertain and/or variable. the northern boundary of the nw river basin could therefore be located, probably, near the torino hills-monferrato thrust front. the clasts of alpine origin, observed in the nw river deposits, could result from the reworking of older alluvial sediments deposited by alpine rivers and from the erosion of conglomerates outcropping between the sediments of the monferrato "ligurian units". the hypothesis of a catchment basin of the nw river mainly limited to the northern monferrato does not exclude, however, the possibility that sometimes an alpine river could have flowed in the southern basin due to the uncertainty of the watershed boundaries. 9. conclusions the study of the plio-pleistocene sedimentary successions and pleistocene deformation phases of the cerrina valley and the southern vercelli plain has enabled the sedimentary and tectonic evolution to be recognized of an area that extended both south and north of the monferrato thrust front, and has also shown that the peculiar geological features of the two areas are not random but due to the correlation between events that have characterized their evolution. in the area north of the thrust fronts, despite the presence of erosion surfaces, sedimentation has prevailed and the sediments are preserved over very wide areas, while south of the fronts, sediments are present 62 giraudi c. only in a small part of the cerrina valley, their thickness is much smaller and the sedimentary sequence show significant gaps. subsidence, linked to thrust front activity, involved both areas, during the same periods, but with different intensity. a first phase of subsidence (s1) occurred in the period before the sub-chron olduvai. for the period immediately following, the lacunae present in the stratigraphy of the po basin do not allow any reliable correlation to be made. the second subsidence phase, subsequent to an erosion phase in the po basin and to a phase of tectonic stability in the cerrina valley, appears chronologically well correlated in the two areas and can be dated between about 1.5 and 0.5 ma bp. as for the main phases of deformation, the tilting of the top of the lacustrine unit (sedimented during the sub-chron olduvai) in the cerrina valley syncline appears to be related to the phase of deformation d1 of the po basin, and to the possible phase of activity of the lucedio and cavourrina faults, while the intense phase of deformation of the sediments of the alluvial units a and b (about 1.07-0.7 ma old) of the cerrina valley syncline is well correlated chronologically with the deformation d2 of the sediments of the po basin and with the phase of activity (f2) of the faults. the interpretation of the data therefore enables it to be assumed that the cerrina valley syncline corresponds to a trough behind the thrust fronts corresponding to the lucedio and cavourrina faults. the set of tectonic deformations that took place during the early pleistocene, due to the evolution of the thrust front and to the subsidence of the cerrina valley syncline, favoured the flow of the nw river to the cerrina valley. between 0.7 and 0.6 ma ago, when the subsidence of the cerrina valley was limited to the eastern part, the flow of the nw river to the valley ended. overall, then, the cerrina valley syncline and the lucedio and cavourrina thrust fronts make the geological situation rather unique within the front that extends from turin to casale monferrato. it follows that, in the area studied, the compressive tectonics not only ceased in a more recent period than in the surrounding area (as suggested also by dela pierre et al., 2003 a;b) but that above the thrust fronts evidenced by seismic lines the faults reach almost ground level, while to the east and west the sediments appear deformed by flexures, at least to a depth of 150200 m below ground level (giraudi, 2014). morphological evidence suggests that, even after the end of the compressive tectonics, the hills north of the cerrina valley underwent an uplift similar to those already reported by carraro and valpreda (1991) in other areas of the monferrato hills and by giraudi (2014) in the vercelli plain, south of the fronts. the uplift probably continued during the late pleistocene and perhaps during the holocene. however, the asymmetry of the cerrina valley in the stretch, orientated w-e, and the presence of a sequence of terraces only on the northern side, suggest that the syncline may have acted, at least until the upper pleistocene, as a boundary between two hilly areas (north and south of the valley) subject to different tectonic evolution. the results of the research suggest that the nw river that entered the cerrina valley probably was a river fed by the alpine valleys lying sw of the aosta valley, or a collector of the streams that drained the northern monferrato. the second hypothesis does not exclude, however, the possibility that, sometimes an alpine river could have flowed in the nw river basin due to the uncertain watershed boundaries. references beatrizzotti g., boni a., vanossi m. (1964) sulla posizione stratigrafica delle septarie nell’estremo nordoccidentale dell’appennino e nelle colline di casale. atti istituto di geologia università di pavia, 15, 24-31. bigi g., cosentino d., parotto m., sartori r., scandone p. (1990) structural model of italy, consiglio nazionale delle ricerche (cnr), progetto finalizzato geodinamica, quaderni de "la ricerca scientifica", 114 (3), 1:500.000 scale, firenze, selca. bonadeo p., brunamonte f., michetti a.m., livio f., fioraso g. (2010) paesaggio sismico dell’arco del monferrato: analisi preliminare. gngts, atti del 16° congresso nazionale, 93-97. bonsignore g., bortolami g.c., elter g., montrasio a., petrucci f., ragni u., sacchi r., sturani c., zanella e. (1969) note illustrative della carta geologica d’italia, fogli 56 e 57 (torino e vercelli). servizio geologico d’italia, roma. burrato p., ciucci f., valensise g. (2012) un approccio geomorfologico per la prima individuazione di strutture potenzialmente sismogenetiche nella pianura padana. gngts, atti del 18° congresso nazionale, 18. carraro f., forno m.g., ricci b. (1980) ricostruzione preliminare dell’evoluzione plio-pleistocenica dell’area corrispondente ai rilievi delle langhe, del monferrato e della collina di torino. contributi alla realizzazione della carta neotettonica d’italia. cnr progetto finalizzato geodinamica sottoprogetto “neotettonica”. pubblicazione n. 356, 315-330. carraro f. & valpreda e. (1991). the middle-upper quaternary of the asti basin. il quaternario, 4, 151-172, roma. carraro f., collo g., forno m.g., giardino m., maraga f., perotto a., tropeano d. (1995) l’evoluzione del reticolato idrografico del piemonte centrale in relazione alla mobilità quaternaria in: polino r. & sacchi r. (eds.), atti del convegno: rapporti alpiappennino. acc. naz. sci. sc. doc, 14, 445-461. cassano e., anelli l., fichera r., cappelli v. (1986) pianura padana: interpretazione integrata di dati geofisici e geologici. 73° congresso della società geologica italiana. 1-27. clari p., bernardi e., cavagna s., dela pierre f., irace a., lozar f., martinetto e., trenkwalder s., violanti d. (2008) alba e tramonto della crisi messiniana. guida all’escursione, alba, 10-11 ottobre 2008. costa m. (2003) the buried apenninic arcs of the po 63 evolution of the northernmost apennine front (piedmont, italy): ... plain and northern adriatic sea (italy): a new model. boll. soc. geol. it., 122, 3-23. dela pierre f., michailov v., polino r. (1995) the tectonosedimentary evolution of the tertiary basins in the western po plain: kinematics inferred from subsidence curves. in: polino r. & sacchi r. (eds.), atti del convegno: rapporti alpiappennino. acc. naz. sci. sc. doc, 14, 129-146. dela pierre f., piana f., boano p., fioraso g., forno m.g., polino r. clari p. (2003a) carta geologica d'italia alla scala 1:50.000, foglio 157 "trino", apat, agenzia per la protezione dell'ambiente e per i servizi tecnici dipartimento difesa del suolo, roma. dela pierre f., piana f., fioraso g., boano p., bicchi e., forno m.g., violanti d., balestro g., clari p., d’atri a., de luca d., morelli m., ruffini r. (2003b) note illustrative della carta geologica d’italia alla scala 1:50,000, foglio 157 trino. apat, agenzia per la protezione dell’ambiente e per i servizi tecnici dipartimento difesa del suolo, roma, 147 pp. devoti r., esposito a., pietrantonio g., pisani a.r., riguzzi f. (2011) evidence of large scale deformation patterns from gps data in the italian subduction boundary. earth and planetary science letters, 311, 230-241. enel (1977) studio geologico della zona di trino vercellese. enel, direzione delle costruzioni, roma, unpublished. enel (1984) rapporto per la localizzazione di una centrale elettronucleare nella regione piemonte. area po 1. enel direzione delle costruzioni, roma. xix volumes, unpublished. galadini f., falcucci e., galli p., giaccio b., gori s., messina p., moro m., saroli m.,scardia g., sposato a. (2012) time intervals to assess active and capable faults for engineering practices in italy. engineering geology, 139-140, 50-65. galli p., castenetto s., peronace e. (2012) may 2012 emilia earthquakes (mw 6, northern italy): macroseismic effects distribution and seismotectonic implications. alpine and mediterranean quaternary, 25(2), 105-123. gibbard p. l., head m. j., walker m. j. c. and the subcommission on quaternary stratigraphy (2010) formal ratification of the quaternary system/ period and the pleistocene series/epoch with a base at 2.58 ma. journal of quaternary science, 25, 96-102. giraudi c. (1981) presenza di depositi mediopleistocenici intensamente deformati in val cerrina (monferrato settentrionale). geogr. fis. din. quat., 4, 69-74. giraudi c. (1983) pontestura, loc. roletto (prov. alessandria). scavo paleontologico. quaderni della soprintendenza archeologica del piemonte, 2, 143 -144. giraudi c., mottura a., sala b., siori m.s., bormioli d. (2003) the castagnone site (cerrina valley, monferrato hills, nw italy): early pleistocene sedimentary record and biochronology. rivista italiana di paleontologia e stratigrafia,109, 3, 517-526. giraudi c. (2014) quaternary studies as a tool to validate seismic hazard potential of tectonic structures: the case of the monferrato thrust front (vercelli plain, nw italy). alpine and mediterranean quaternary, 27, 1,5-28. giraudi c. (2015a) quaternary evolution of the plain between casale monferrato and valenza: implications for the tectonics of the monferrato thrust front (piedmont, nw italy). alpine and mediterranean quaternary, 28, 1, 71-92. giraudi c. (2015b) could the low cerrina valley (piedmont nw italy) be an early and middle pleistocene trough developed behind the monferrato thrust front? in abstracts volume aiqua congress 2015: the plio-pleistocene continental record in italy: highlights on stratigraphy and neotectonics. torino, italy, february 24-26. miscellanea ingv, 26, 24-25. isn 2039-6651. gliozzi e., abbazzi l., argenti p., azzaroli,a., caloi l., capasso barbato l., di stefano g., esu d., ficcarelli g., girotti o., kotsakis t., masini f., mazza p., mezzabotta c., palombo m.r., petronio c., rook l., sala b., sardella r., zanalda e., torre d. (1997) biochronology of selected mammals, molluscs and ostracods from the middle pliocene to the late pleistocene on italy. the status of the art. riv. ital. paleont. strat., 103, 369-388. irace a., clemente p., natalicchio m., ossella l., trenkwalder s., de luca d.a., mosca p., piana f., polino r., violanti d. (2009) geologia e idrostratigrafia profonda della pianura padana occidentale. 110 pp, 61 allegati. la nuova lito, firenze. livio f., ferrario m.f., frigerio c., michetti a.m. zerboni a., bonadeo l., fioraso g., irace a., brunamonte f. (2015) late pleistocene reverse surface faulting at the pecetto di valenza site (alnorthern italy): preliminary results. conference of the gngts, sessione 1.1, 45-50. lovari d. (1912) descrizione dei giacimenti calcareomarnosi delle colline di casale monferrato ed alcuni cenni sulla loro utilizzazione per la produzione della calce idraulica e del cemento. ministero industria e commercio, ispettorato miniere, roma, 54 pp. lupano g. (1912) cenni geologici sui dintorni di camino monferrato. atti società italiana di scienze naturali, 51, 145-190. michetti a. m., giardina f., livio f., mueller k., serva l., sileo g., vittori e., devoti r., riguzzi f., carcano c., rogledi s., bonadeo l., brunamonte f., fioraso g. (2012) active compressional tectonics, quaternary capable faults, and the seismic landscape of the po plain (northern italy). annals of geophysics, 55, 5, 969-1001. montrasio a., ragni u., bonsignore g., borgo a., zanella e., crema g., medioli f., petrucci f. (1969) foglio 57, vercelli, della carta geologica d’italia alla scala 1:100,000. ii ed., servizio geologico d’italia, roma. muttoni g., ravazzi c., breda m., pini r., laj c., kissel c., mazaud a., garzanti e. (2007) magnetostratigraphic dating of an intensification of glacial activity in the southern italian alps during marine isotope 64 giraudi c. stage 22. quaternary research, 67, 161-173. pieri m., groppi g. (1981) subsurface geological structure of the po plain, italy. quad. cnr. prog. fin. geodinamica, roma, 1-13. sacco f. (1889) il bacino terziario e quaternario del piemonte. atti società italiana di scienze naturali, 31-32, 135-281, 289-398, 331-390. siori m.s., sala b. (2007) the mammal fauna from the late early biharian sito of castagnone (northern monferrato, piedmont, nw italy). geobios, 40, 207217. 65 evolution of the northernmost apennine front (piedmont, italy): ... ms. received: march 16, 2016 final text received: july 18, 2016 66 << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /none /binding /left /calgrayprofile (dot gain 20%) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /error /compatibilitylevel 1.4 /compressobjects /tags /compresspages true /convertimagestoindexed true /passthroughjpegimages true /createjobticket false /defaultrenderingintent /default /detectblends true /detectcurves 0.0000 /colorconversionstrategy /cmyk /dothumbnails false /embedallfonts true /embedopentype false /parseiccprofilesincomments true /embedjoboptions true /dscreportinglevel 0 /emitdscwarnings false /endpage -1 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can be opened with acrobat and adobe reader 5.0 and later.) >> /namespace [ (adobe) (common) (1.0) ] /othernamespaces [ << /asreaderspreads false /cropimagestoframes true /errorcontrol /warnandcontinue /flattenerignorespreadoverrides false /includeguidesgrids false /includenonprinting false /includeslug false /namespace [ (adobe) (indesign) (4.0) ] /omitplacedbitmaps false /omitplacedeps false /omitplacedpdf false /simulateoverprint /legacy >> << /addbleedmarks false /addcolorbars false /addcropmarks false /addpageinfo false /addregmarks false /convertcolors /converttocmyk /destinationprofilename () /destinationprofileselector /documentcmyk /downsample16bitimages true /flattenerpreset << /presetselector /mediumresolution >> /formelements false /generatestructure false /includebookmarks false /includehyperlinks false /includeinteractive false /includelayers false /includeprofiles false /multimediahandling /useobjectsettings /namespace [ (adobe) (creativesuite) (2.0) ] /pdfxoutputintentprofileselector /documentcmyk /preserveediting true /untaggedcmykhandling /leaveuntagged /untaggedrgbhandling /usedocumentprofile /usedocumentbleed false >> ] >> setdistillerparams << /hwresolution [2400 2400] /pagesize [612.000 792.000] >> setpagedevice imp.bartolini la morfotettonica ed i suoi limiti come strumento d’indagine neotettonica carlo bartolini dipartimento di scienze della terra – università di firenze riassunto: bartolini c., la morfotettonica ed i suoi limiti come strumenti d’indagine neotettonica. (it issn 0394-3356, 2004). brevi riflessioni su come lo strumento morfotettonica è stato utilizzato nel nostro paese nell’arco degli ultimi trent’anni. abstract: bartolini c., morphotectonics and its limit as a tool of neotectonic investigation. (it issn 0394-3356, 2004). the author describes the way morphotectonic methods have been applied to the study of recent tectonics in italy during the last thirty years. parole chiave: morfotettonica, neotettonica. keywords: morphotectonics, neotectonics. il quaternario italian journal of quaternary sciences 17(2/1), 2004, 251-257 1. introduzione in perfetta consonanza con l’etimo, geomorfologi e geologi strutturali hanno fatto ampio ricorso al metodo soprattutto a partire dagli anni ’60. raramente le ricerche sono state condotte da gruppi di studio ben bilanciati dal punto di vista disciplinare. per questo, alcuni oggetti di studio sono stati differentemente interpretati da ricercatori diversi e di diversa estrazione. di qui alcuni interrogativi che la disciplina suscita riguardo alla sua utilità e validità. un rapido excursus su alcuni significativi contributi pubblicati nel corso degli ultimi 40 anni in italia è il filo conduttore che può essere seguito per valutare come è evoluto l’approccio metodologico nell’ambito della comunità scientifica nazionale. 2. la fase garibaldina a parte alcuni lavori pionieristici (segre, 1950 “nastri di faglia” e biasini, 1966), la morfotettonica come metodo d’indagine è stata sostanzialmente ignorata fino alla metà degli anni ‘70. un decisivo impulso è derivato, in quegli anni, dagli studi inerenti la realizzazione della carta neotettonica d’italia del progetto finalizzato “geodinamica” del cnr. fu allora evidente, infatti, che solo l’approccio morfotettonico era in grado di fornire elementi di valutazione dell’attività tettonica recente laddove, in assenza di depositi quaternari, i tradizionali metodi propri della geologia non sono applicabili. gli studi promossi dal cnr furono in parte anticipati da analoghe indagini promosse dall’enel (1981), nelle quali gli indizi morfotettonici, spesso acriticamente presentati, ebbero un ruolo dominante. a che punto erano, in quel tempo, le conoscenze sul metodo ed i suoi limiti, anche in campo internazionale? preliminari valutazioni morfotettoniche su alcune scarpate di faglia erano state presentate da wallace (1977), anderson (1977) e da bucknam e anderson (1979). tali lavori non erano comunque noti alla maggioranza dei ricercatori impegnati, più o meno negli stessi anni, nel sottoprogetto carta neotettonica. d’altra parte, i precedenti, importanti contributi di bull (1964) e di hack (1973) relativi rispettivamente all’analisi morfotettonica dei depositi di conoide e dei gradienti fluviali erano stati pubblicati in rapporti tecnici di difficile reperibilità. per questo, gran parte dei ricercatori impegnati nel sottoprogetto carta neotettonica utilizzò inizialmente su larga scala uno strumento di indagine di cui nessuno aveva letto (perché non esisteva) il manuale d’impiego. così, in molti casi, determinate forme venivano interpretate come il possibile risultato dell’attività tettonica senza prendere seriamente in esame le cause di tipo morfoselettivo e i processi in grado di dar luogo a forme convergenti. questo approccio fu oggetto di un’approfondita disamina di bosi (1978). nettamente in anticipo sui tempi, apparve, in quegli anni, il contributo di sauro (1978) relativo alle “forme strutturali e neotettoniche nei monti lessini”. laddove erano disponibili anche dati geologici, la disparità delle interpretazioni costituì oggetto di serrati e prolungati dibattiti, non sempre risolti con soddisfazione degli interessati. per questo, nella carta neotettonica a scala 1:500.000 sono evidenti le singolari differenze nella densità degli elementi lineari in aree contermini, affidate a gruppi diversi di ricercatori che avevano considerato o meno come di interesse neotettonico gli elementi emersi in base soltanto ad evidenze morfologiche. 252 c. bartolini 3. la predilezione per le interpretazioni in chiave tettonica e sismotettonica la preferenza che dai ricercatori è stata sempre accordata in buonissima fede alle interpretazioni in chiave tettonica piuttosto che morfoselettiva o imputabile a particolari processi (si pensi al negletto ruolo della gravità) delle evidenze morfologiche, ha una motivazione abbastanza ovvia: l’accertare che una certa forma è espressiva di tettonica recente rappresenta, per il ricercatore, un risultato, mentre non lo è se la forma è riconducibile a cause diverse. citiamo, come esempio fra i tanti, le evidenze morfostrutturali segnalate da a. carton, r. iacuzzi, m. panizza & f. vaia, 1978, a proposito della faglia di nimis (fig. 1): se riconosciute come forme di erosione passiva, esse non avrebbero avuto alcun interesse ai fini della redazione della carta neotettonica. come esempio di eccessivo “peso” attribuito a possibili cause tettoniche senza un’adeguata valutazione del ruolo dei processi, possiamo riferirci al margine sud-orientale delle colline de le cerbaie, interpretato da bartolini e pranzini (1979) come scarpata di faglia (fig. 2). fig. 1 evidenze di tettonica recente lungo la faglia di nimis. tutte le forme segnalate in legenda sono interpretabili anche come forme di erosione selettiva (controllo passivo della struttura sulla morfologia). da carton, iacuzzi, panizza e vaia (1978). evidences of recent tectonic activity along the nimis fault. all features may be also interpreted as due to differential erosion (i.e. passive control exerted by the geologic structure on surface morphology). from carton iacuzzi, panizza and vaia (1978). fig. 2 a, b il margine sud-orientale delle colline de le cerbaie, interpretato da bartolini e pranzini (1979) come scarpata di faglia. in assenza di prove geologiche di un sollevamento differenziale che abbia interessato i depositi “villafranchaini” sui due lati del corso dell’arno, sarebbe stato più prudente imputare la scarpata ad erosione laterale di questo fiume e del suo affluente di destra, il pescia. the southeastern margin of le cerbaie, interpreted by bartolini and pranzini (1979) as a fault scarp. due to the lack of geological evidences of any differential uplift affecting the so called “villafranchian” deposits on the two sides of the arno river, it would have been safer to interpret the scarp as due to the lateral erosion of this river and of his tributary, the pescia river, which flow alongside the scarps. in assenza di prove geologiche di un sollevamento differenziale che abbia interessato i depositi “villafranchiani” sui due lati del corso dell’arno, sarebbe stato preferibile imputare la scarpata ad erosione laterale di questo fiume e del suo affluente di destra, il pescia, che scorrono rispettivamente a se ed est delle faglie che delimitano verso oriente le cerbaie. il ruolo morfogenetico dell’arno è stato invece riconosciuto, da parte degli stessi autori, a proposito delle faccette triangolari, scolpite in calcari, che orlano questo fiume a monte di firenze (fig. 3). dal momento che le faccette si trovano sul lato ribassato della faglia 253la morfotettonica ed i suoi limiti ... che mette a contatto i calcari alberesi, al tetto, con la formazione di sillano (fig. 4), non sarebbero forme tettoniche ma piuttosto imputabili all’erosione al piede esercitata dal fiume. presumibilmente modellate nel corso del pleistocene sup., esse hanno mantenuto una buona evidenza morfologica grazie all’elevata conservatività dei calcari della formazione di m. morello (vulgo alberese). l’interpretazione non è condivisa da boccaletti et alii (2001), che segnalano, al piede di queste faccette, una “major active fault”. la pubblicazione citata riguarda la zonazione sismica dell’area fiorentina. la tettonica recente quale indicatore di sismicità è strumento troppo attraente per non essere coltivato anche con qualche inconsapevole forzatura. come esempio di quanto la prospettiva sismotettonica possa condizionare l’interpretazione morfotettonica, citiamo il caso classico del m. parasano, in abruzzo. uno specchio di faglia affiora sul margine sudoccidentale. il piano appare esposto per erosione del la copertura detrit ica e non a seguito di una recente riattivazione della faglia. l’entità dell’esposizione varia infatti lateralmente fino ad annullarsi. serva et al. (1986), serva (1990) e blumetti et alii (1993) hanno incluso la faglia fra quelle riattivate nel corso del terremoto del fucino (1915) mentre bosi et al. (1993) ritengono che la faglia, benché attiva nel pleistocene superiore (la copertura detritica è infatti fagliata), non abbia rigiocato in occasione del terremoto. l’interpretazione in chiave morfoselettiva della faglia del m. parasano non è certo così scontata quanto può esserlo, ad esempio, quella della faglia di plakias, a creta (fig. 5 a,b), dovuta al grande divario litologico che caratterizza muro e tetto. le vistose variazioni laterali di esposizione del piano di faglia indicano che si tratta di una scarpata erosiva e non tettonica. non è comunque mai facile distinguere le cause morfoselettive da quelle tettoniche: alcune delle forme che keller (1986) nel suo notissimo schema (fig. 6) imputa ad attività recente di una faglia trascorrente possono parimenti prodursi per erosione selettiva. e’ specificamente il caso del piccolo corso d’acqua che attraversa la faglia di san andreas nella carrizo plain (fig. 7). fig. 3 faccette triangolari, scolpite in calcari, sul versante sinistro della valle dell’arno a monte di firenze. triangular facets carved in limestone on the left hand slope of the arno valley, upstream to florence. fig. 4 le evidenze geologiche fanno ritenere che le faccette si trovino sul lato ribassato della faglia (a sin. nella sezione). pertanto non sarebbero forme tettoniche ma piuttosto imputabili all’erosione al piede esercitata dal fiume. presumibilmente modellate nel corso del pleistocene sup., esse hanno mantenuto una buona evidenza morfologica grazie all’elevata conservatività dei calcari della formazione di m. morello (vulgo alberese). da bartolini e peccerillo (2002). the geological evidences show that the facets lay on the downthrown side of the fault (on the left in the geological section). therefore they appear to be originated by the lateral erosion of the river rather than being segments of a fault scarp. although apparently carved during the upper pleistocene, they maintained their shape due to highly conservatory attitude of the limestone relief. 254 4. la fase riflessiva esauriti i lavori inerenti la carta neotettonica d’italia, alcuni (solo alcuni) dei ricercatori che vi avevano contribuito si dedicarono ad approfondire le tematiche che in precedenza avevano utilizzato senza avere la possibilità materiale di effettuarne una ponderata valutazione. sono stati in particolare presi in esame, da parte di molti, i rapporti che intercorrono fra attività tettonica recente e processi erosivi e sedimentari che interagiscono con essa, consentendone un’accurata scansione temporale. fig. 5a, b scarpata di linea di faglia di plakias (isola di creta) dovuta al grande divario litologico che caratterizza muro e tetto. le vistose variazioni laterali di esposizione del piano di faglia indicano che si tratta di una scarpata erosiva e non tettonica. the plakias fault line scarp (crete) is due to the large lithologic difference between the hanging and footwall. the sizable lateral variations of the fault plane exposure point to an erosional rather than tectonic origin of the scarp. a) b) c. bartolini 255 la casistica è assai vasta e non sintetizzabile in questa sede. ci limitiamo a citare qualche esempio. ancora quando i lavori della carta neotettonica erano ancora in corso, brancaccio et al. (1979) analizzarono l’applicazione del modello di lehmann ai versanti di faglia dell’appennino meridionale, concludendo che è “molto difficile valutare la velocità di arretramento di un versante e risalire all’età della faglia che lo ha determinato sulla base di criteri esclusivamente geomorfologici”. relativamente alla cosiddetta “età della faglia”, pervenne invece a risultati incoraggianti qualche anno dopo nash (1986) che tuttavia operava in un contesto assai più favorevole: l’evoluzione erosiva delle scarpate di faglia che interessano le superfici di conoidi alluvionali. venne pubblicato alcuni anni dopo il fondamentale contributo di brancaccio et al. (1986) relativo agli “elementi morfostruttural i ereditati nel paesaggio dell’appennino centro-meridionale”, nel quale si afferma la possibilità che “elementi morfostrutturali ascrivibili al periodo della tettogenesi si trasmettano al paesaggio odierno senza subire dei modellamenti erosionali tali ”da conferir loro “una maturità che ne denunci l’età”. più recentemente, anche ascione e cinque (1995) hanno potuto accertare che gran parte delle morfostrutture associate a faglie sono dovute ad erosione selettiva. a scala di catena, invece, il condizionamento geodinamico del rilievo appenninico è stato recentemente messo in evidenza da salustri galli et al. (2001). la non coincidenza fra cime più alte e spartiacque appenninico ha trovato una convincente risposta, almeno nei suoi termini generali, 75 anni dopo che era stato evidenziato da marinelli. nel 1993 carraro ha sintetizzato la sua ventennale esperienza in materia delineando i criteri utilizzabili per evidenziare l’evoluzione recente di faglie. negli esempi presentati da questo autore, lo strumento ”morfotettonica” appare in molti casi inutilizzabile se non in stretta sinergia con valutazioni geologicostrutturali. di fatto, a partire dagli anni ’90, l’attività recente delle faglie viene principalmente valutata sulla base delle deformazioni indotte nei depositi ad esse associati. studi di dettaglio condotti su trincee in appennino meridionafig. 7 la deflessione del corso d’acqua può essere dovuta sia a cause tettoniche (il corso d’acqua subisce la trascorrenza della faglia di san andreas) che morfoselettive (utilizza la traccia della faglia per superare l’ostacolo e riprendere la direzione originaria del delusso) oppure ad una combinazione di cause. foto c. bosi. .the dextral deflection of the stream may be due to tectonics (the stream is deflected by the dextral slip of the san andreas fault), to differential erosion (the stream follows the fault line in order to be able to overcome the obstacle and then resume its former trend downhill) or to a concurrence of the two causes. fig. 6 -alcune delle forme ritenute indicative di attività recente della faglia (es.: scarpate e anomalie del reticolo) possono prodursi anche per erosione selettiva. da keller, 1986. a few features reported as indicative of recent fault activity (e.g. scarps and drainage anomalies) can be produced also by differential erosion. from keller (1986). la morfotettonica ed i suoi limiti ... 256 le hanno rivelato tassi di attività generalmente maggiori di quanto l’analisi morfologica di superficie avrebbe potuto evidenziare (es. ascione e cinque, 1997). se in alcuni casi tale discrepanza può essere imputata al diverso ambito cronologico cui i due metodi di indagine fanno riferimento, e al fatto che i ritmi dell’attività tettonica non sono costanti, più in generale il divario dovrebbe ricordarci che le evidenze morfologiche dell’attività tettonica recente sono condizionate, in misura diversa e solo parzialmente quantificabile, dall’intensità dei processi erosivi. questi dipendono da fattori climatici, che conosciamo sommariamente nelle loro caratteristiche medie ma rispetto ai quali ignoriamo la dimensione e la cadenza degli eventi estremi così importanti nella morfogenesi e da fattori litologici che crediamo di conoscere ma di cui, per lo più, ignoriamo perfino i termini del problema. prova ne siano le affermazioni del tipo “…si esclude che si tratti di erosione selettiva, dato che l’elemento morfotettonico in discussione è situato nella zona di affioramento di un’unica formazione” che non di rado compaiono sulle riviste specialistiche. 5. conclusione retrospettiva gli approfondimenti metodologici e quindi conoscitivi cui si è pervenuti in questi ultimi anni portano a ritenere che una carta neotettonica d’italia realizzata adesso avrebbe un aspetto assai diverso da quella pubblicata nel 1984 anche, ma non solo, per la maturazione di idee che ha riguardato i metodi della morfotettonica. non è il caso, però, di rinnegare il passato: è stata proprio l’esperienza scaturita da quel progetto a stimolare una maturazione di idee che è oggi in buona parte compiuta. almeno così a noi sembra. 6. prospettive vi sono alcuni metodi propri della morfotettonica che sono stati assai poco utilizzati nel nostro paese. pensiamo per esempio allo studio delle “unpaired strath terraces” in grado di fornire una prova dell’eccesso di capacità erosiva del corso d’acqua in rapporto al tasso di sollevamento regionale, che si traduce in erosione laterale (merritts et al., 1994). il riconoscimento di questo tipo di terrazzi fluviali consente anche una “salutare” riflessione sul fatto che, essendo asimmetricamente posizionati (“unpaired”) sui due lati della valle, i terrazzi fluviali non corrispondono a fasi differenziate nel tempo, come generalmente ci accontentiamo di credere, sono invece il risultato di un processo relativamente continuo di incisione ed erosione laterale (cfr. fig. 1 in santangelo, 2003). in questo ambito, la cronologia radiometrica dei terrazzi costituisce un indispensabile strumento di indagine. l’impiego degli isotopi radiogenici ha aperto, da questo punto di vista, nuove interessanti prospettive. anche lo studio dei dislivelli fra sistemi carsici ipogei e livello di base attuale (piccini et al., 2001 e piccini e drysdale, 2003) attende di essere applicato in numerosi massicci calcarei del nostro paese. lo stesso vale per la possibilità di riconoscere situazioni di sollevamento differenziale in base all’analisi dell’evoluzione del pattern idrografico (bartolini e fazzuoli, 1997, bartolini e peccerillo, 2002, figg. 6.1.4 – 6.1.7). in termini generali, i modelli di evoluzione del rilievo basati sull’integrazione di dati geodinamici, morfotettonici e morfoclimatici sono l’obiettivo più alto cui la nostra disciplina può contribuire. si tratta di avere l’umiltà e la pazienza di mettere in discussione le proprie idee con colleghi di diversa formazione, uscendo dalla autoreferenzialità che ancora caratterizza molti studi di morfotettonica. lo schema pubblicato da santangelo (2003) costituisce un esauriente ed aggiornato pro-memoria. attenzione, però. quasi tutti gli indicatori geomorfologici elencati possono avere anche una causa non tettonica, generalmente di tipo morfoselettivo. ma forse è proprio questa sua intrinseca ambiguità a rendere il metodo intrigante. lavori citati anderson t.c. (1977) compound faceted spurs and recurrent movement in the wasatch fault zone, north central utah. brigham young univ. geol. stud., 24, 83-101. ascione a. & cinque a. (1995) l’età della tettonica trascorrente nell’appennino campano: il contributo dell’analisi geomorfologica. st. geol. camerti, vol. sp., 1995/2. bartolini c. & fazzuoli m. (1997) ruolo della tettonica e della morfoselezione nell'evoluzione dell'idrografia nel bacino del f. serchio. il quaternario, 10, 415 424. bartolini c. e peccerillo a. (2002) i fattori geologici delle forme del rilievo. lezioni di geomorfologia strutturale. ii ed. pitagora editrice bologna, 216 pp. bartolini c. & pranzini g. (1979) dati preliminari sulla neotettonica dei fogli 97 (s. marcello pistoiese), 105 (lucca) e 106 (firenze). contributi preliminari alla realizzazione della carta neotettonica d'italia, pubbl. n. 251 del p.f. geodinamica, 481-523. biasini a. (1966) elementi morfotettonici, tratti da un rilievo fotogeologico, al margine dell’altipiano di ovindoli (abruzzo). geol. romana, 5, 303-312. blumetti, dramis & michetti (1993) fault-generated mountain fronts in the central apennines (central italy): geomorphological features and seismotectonic implications. earth surf. proc. landforms, 18, 203-223. boccaletti m., corti g., gasperini p., piccardi l., vannucci g. & clemente s. (2001) active tectonics and seismic zonation of the urban area of florence (italy). pure appl. geophys., 158, 23132332. bosi c. (1978) relazione introduttiva al tema “neotettonica”. mem. soc. geol. it., 19, 521-534. bosi c., galadini f. & messina p. (1993) neotectonic significance of bedrock fault scarps: case studies from the lazio-abruzzi apennines (central italy). z. geomorph. suppl.-bd. 94, 187-206. brancaccio l., cinque a. & sgrosso i. (1979) forma e genesi di alcuni versanti di faglia in rocce carbonatiche: il riscontro naturale di un modello teorico. rend. accad. sc. fis. mat. serie iv, 46, 21 pp. c. bartolini brancaccio l., cinque a. & sgrosso i. (1986) elementi morfostrutturali ereditati nel paesaggio dell’appennino centro-meridionale. mem. soc. geol. it., 35, 869-874. bucknam r.c. & anderson r.e. (1979) estimation of fault-scarp ages from a scarp-height-slope-angle relationship. geology, 7, 11-14. bull w.b. (1964) geomorphology of segmented alluvial fans in western fresno county, california. u.s. geol. survey prof. paper 352-e, 89-129. carraro f. (1993) criteri per evidenziare l’evoluzione recente di faglie. il quaternario, 6, 15-26. carton a, iacuzzi r., panizza m. & vaia f. (1978) segnalazione di una dislocazione neotettonica nel friuli fra il m. stella e il m. forchiat di reclus (attimis). mem. soc. geol. it., 19, 563-572. enel (1981) elementi di neotettonica del territorio italiano. 95 pp. hack j.t. (1973) stream-profile analysis and streamgradient index. u.s. geol. survey j. res., 1, 421429. keller e.a. (1986) investigation of active tectonics: use of surficial earth processes. active tectonics. nat. acad. press, washington, pp. 136-147. marinelli o. (1926) la maggiore discordanza tra orografia e idrografia nell'appennino. riv. geogr. it., 33, 65-74. merrits d.j., vincent k.r. & wohl e. e. (1994) long river profiles, tectonism, and eustasy: a guide to interpreting fluvial terraces. jour. geoph. res., sp. section on tectonics and topography, part ii, 99, 14031 14050. nash d.b. (1986) morphologic dating and modeling degradation of fault scarps . in: studies in geophysics active tectonics. nat. acad. press, washington, pp. 181-194 ouchi s. (1985) response of alluvial rivers to slow tectonic active movements. geol. soc. am. bull., 96, 504-515. salustri galli c., torrini a., doglioni c. & scrocca d. (2001) divide and highest mountains vs subduction in the apennines. st. geol. camerti, 1 ns, 143-153. piccini l., drysdale r., heijnis h., (2001) karst caves morphology and sediments as indicators of the uplift history in the alpi apuane (tuscany, italy). workshop "uplift and erosion", certosa di pontignano (siena), september 20 and 21, 2001. quaternary international, 101-102 (2003), 219227. piccini l., drysdale r. (2003) vincoli morfologici e cronologici per una ricostruzione dell’evoluzione del carsismo delle alpi apuane. atti 19° congr. naz. spel., bologna, 27-31 agosto 2003, sottoterra, 114, 29-34. santangelo n. (2003) interazione fra tettonica recente e processi geomorfici. il quaternario, 16, 27-34. sauro u. (1978) forme strutturali e neotettoniche nei monti lessini. gr. st. quat. padano, quad. n°4. segre a. (1950) sulla struttura dell’arco abruzzese interno. contributi di scienze geologiche, suppl. ric. scient., cnr, roma, 1-16. serva l. (1990) effetti sui suoli dei terremoti antichi e recenti nella piana del fucino. in: guidoboni e. (ed.): i terremoti prima dell’anno mille. ist. naz. geof., pp. 530-536. serva l., blumetti a.m. & michetti a.m. (1986) gli effetti sul terreno del terremoto del fucino (13 gennaio 1915); tentativo di interpretazione della evoluzione tettonica recente di alcune strutture. mem. soc. geol. it., 35, 256-263. wallace r.e. (1977) profiles and ages of young fault scarps, north-central nevada. geol. soc. am. bull., 88, 1267-1281. 257 ms. ricevutoil 1° giugno 2004 testo definitivo ricevuto l’8 novembre 2004 ms. received: june 1, 2004 final text received: november 8, 2004. la morfotettonica ed i suoi limiti ... amq58 sauro last.pub �� � �available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 30 (1), 2017, 75-85 problematic karst fillings of late lower pleistocene age in a cave of the lessini mountains (venetian fore alps, verona)* ugo sauro 1, federico zorzi 2,3 1 museo etnografico di bosco chiesanuova, bosco chiesanuova (vr), italy 2 dipartimento di geoscienze, università di padova, padova, italy 3 ceasc (centro di analisi e servizi per la certificazione), università di padova, padova, italy corresponding author: u. sauro <ugo.sauro@gmail.com> abstract: the excavation of a small cave in the lessini mountains, north of verona, allowed a study of an archaeological complex attributable to the copper age. a fossiliferous breccia, rich in bones of small mammals and birds has been found below the archaeological levels. during 2005 and 2006, the results of paleontological excavations supervised by benedetto sala provided a faunal assemblage correlated to the late biharian. these excavations stimulated a preliminary study of the geological, geomorphological and morphodynamic context of the cave and its surroundings, in order to understand its genetic context. particular attention was paid to the breccia, containing numerous small exotic pebbles, mostly 5-12 mm in diameter. we consider three different hypotheses for the provenience of the exotic pebbles: i) they have been transported and displaced in the area by morphodynamic agents, such as ancient glaciers, and/or watercourses ii) they derive from a completely eroded geological formation, that has been reworked and deposited in this karst trap, iii) they are the result of "ecofacts" caused by birds. all these possible explanations, have some open issues. the “ecofacts” is the most intriguing hypothesis and perhaps the most likely: pebbles could have been transported by birds which use to swallow them to help digestion, then to expel them in boluses or in the excrements. according to this hypothesis, birds could have chosen the cave, or others connected cavities, as nests or as perches. in fact, in the breccia there are bones of large birds of prey, not jet studied. in time, probably, different species of birds have colonized these natural niches, as: vultures, eagles, owls, ravens, etc. so it is very difficult to state what kind of birds could have brought here their preys (the small mammals of which we find the bones), and what kind of birds could have transported the small pebbles. only further excavations and studies will perhaps allow a full clarification of the processes of site formation. keywords: limestone cliffs, cave deposits, exotic pebbles, slivia faunal assemblage, biharian. 1. introduction the excavation of a small cave, called buso della fadanana, in the lessini mountains, north of verona, has allowed a study of an archaeological complex attributable to the copper age (sauro et al., 2007). below the archaeological levels, a fossiliferous breccia has been found, containing a faunal assemblage referable to the late lower pleistocene (late biharian). these excavations stimulated a preliminary study of the geological, geomorphological and morpho-dynamic context in which the cave is located, in order to understand its genetic context. in particular, the purpose of this note is to analyse a problematic aspect of the fossiliferous breccia, namely the presence of numerous rounded pebbles, referable to lithologies not occurring in this karst system and, in some cases, not even in the pre-alpine group of lessini mountains. based on the current state of knowledge, considering the characters of the pebbles, which fall into a strict dimensional range and largely derive from carbonate rocks, the natural morpho-dynamic processes seem unable to explain this occurrence. on the other hand, the available literature on fossil bearing infillings in karst cavities does not illustrate similar situations. it was therefore decided to analyse this aspect of the breccia searching for its meaning in a paleo-environmental reconstruction. it is hoped that further research on this and other similar cavities will contribute to a deeper understanding of the alpine karst environments during the lower pleistocene. 1.1. a complex karst system and its geomorphological context the entrance of the small cave containing the breccia opens on a rock wall at 752 m a.s.l., hanging about 150 m above the valley bottom, in the upper belt of the right slope of the vajo di squaranto, a canyon-like valley in the lessini mountains (venetian fore-alps), in the municipality of bosco chiesanuova, about 20 km north of the town of verona (ne italy). � ____________________________ *u. sauro coordinated this research work; f. zorzi analysed the small pebbles and took part to the discussion. �� � � 76 sauro u. & zorzi f. the east facing wall is about 400 m long and 1080 m high. it consists of jurassic limestone, with the superimposition of two types of rocks: the rosso ammonitico veronese in the upper part and the oolite di san vigilio in the lower part. the anti-dip slope beds, dipping about 10° wsw (figg. 1, 2, 3) are capped by the rosso ammonitico, acting as a caprock. these structural conditions are favorable to the conservation of the rock wall. only in the southern sector, where rosso ammonitico has been eroded, the wall tends to retreat faster and its height is decreasing; the cave is located in this sector. in the rock wall, it is possible to recognize several types of forms (fig. 2). in particular: sub vertical channel, entrance of cave, sub-horizontal notch, developed either above rock cut terraces and in the vertical surfaces, large half-dome niche, recess with mostly vertical development. all these forms are explainable with the geomorphological environment of the rock wall, and in particular with: a) the characters of the different geological formations, b) their tectonic setting, c) the gravity induced processes, d) the karst and weathering processes resulting from the circulation of the karst waters. with regard to point d), the evolution of the underground karst network is an expression of a downward transition from a horizontal circulation (hanging aquifers hosted in dense lithoclastic networks) to an essentially vertical one (diaclastic circulation), from the maiolica to the rosso ammonitico and to the oolite di san vigilio (mégnien, 1966; sauro, 1973, 1974, 1999) (fig. 3). the maiolica is the rock formation above the rosso ammonitico on the top of the ridge. it is strongly fractured and hosts hanging aquifers which lose waters through the main fractures of the rosso ammonitico, feeding a circulation in the oolite di san vigilio. over time, the water forms shaft cavities inside this rock and bedding plain conduits. the lower part of the oolite di san vigilio is massive and contains thin clayey layers, that can favour the formation of local hanging aquifers. the perched water bodies feed many tiny temporary karst springs, which favour a relatively faster weathering of the rock wall just above the impermeable layers and the consequent development of niches and large horizontal notches (figg. 2, 3). where the wall is still capped by the rosso ammonitico, the notches, the half-dome niches, and the recesses are relatively stable forms. instead, in the areas where the rock is strongly fractured and the caprock has been eroded, sub-vertical channels have formed through the collapse of large blocks. in the faster retreating portions of the rock wall, a hanging rock terfig. 1 geological map of the area (from the “carta geologica d’italia”, f° 49 verona, original scale 1:100.000). rw: rock wall described in the paper, ma: maiolica formation, ra: rosso ammonitico formation, osv: oolite di san vigilio formation. � �� � � 77 problematic karst fillings of late lower pleistocene age in a cave of the monti lessini …. � f ig . 2 p an or am a of th e ro ck w al l a nd o f i ts m ai n la nd fo rm s (t he s ca le is in di ca tiv e) . f ig . 3 s ke tc h of t he s ec tio n of t he r oc k w al l, of i ts s tr uc tu ra l se tti ng , hy dr oge ol og ic al c ha ra ct er is tic s an d ka rs t fe at ur es ( th e sc al e bo th h or iz on ta l a nd v er tica l i s th e sa m e an d it is in di ca tiv e) . �� � � race may develop above the impermeable layers and in front of the notches. two half-dome niches, more than ten meters high, wide and deep, have developed by multiple processes: weathering induced by the karst waters and intersection of vertical karst cavities by the surface of the retreating rock wall. the recesses with mostly vertical development are also the result of the intersection of karst cavities by the retreating rock wall. the entrance of the buso della fadanana cave is located at the base of a sub vertical channel in the wall: a gully which puts it in relation with the gently sloping surfaces of the ridge located upstream. the cave entrance was nearly completely closed by a talus cone, formed by a body of large collapse blocks (sbcb, in fig. 4), covered by fine clastic deposits, mostly composed by soil and small and medium sized blocks (range between centimetres and decimetres) (lhasc, in fig. 4). the accumulation of the cover sediments (lhasc) is the result of human impact on the surrounding environment during protohistoric and historic times, consisting in the deforestation of the area and the uses of soil for grazing and agriculture (sauro et al., 2007). the cavity has, therefore, according with its topographical position, represented a sedimentary trap. beside buso della fadanana, three others caves have been explored and mapped along the rock wall. all of them fit within the above-sketched hydrogeological model (fig. 3). buso della fadanana is the shortest, developing for about 11 m (but it is possible to see an inaccessible prosecution, inside the sedimentary fillings); grotta di squaranto, also called buso del beco, is the longest, about 145 m in development (salzani & sauro, 1986). 2. the fillings of the cave the deposits inside the buso della fadanana have been partly excavated between 2000 and 2003, in order to analyse their archaeological content (sauro et al., 2007). the digging has evidenced that the upper sedimentary complex has accumulated in a time range between copper and modern age. the over 2 meters’ thick deposit is rich in archaeological materials (ceramics, lithic industry, bones). it presents the structure of a sedimentary cone with layers inclined towards the interior of the cavity (fig. 4). at the base of this upper complex, the loess-like sediments found in the not far grotta di squaranto (salzani & sauro, 1986) are completely missing. this could be probably linked to the occurrence of large collapsed blocks (sbcb) completely closing the cave (see fig. 4). the excavations carried out in the years 2005 and 2006 and supervised by benedetto sala have uncovered different sediments below this upper complex and in the inner part of the cave. this “lower complex” mainly consists of a reddish (munsell color: dry 5yr 6/6, moist 4/6) matrix-supported breccia, made up of a red clay containing clasts as stones, pieces of flowstone, pebbles and fossil bones (lmpsc, in fig. 4). inside the breccia, some thin flowstone levels, and other discontinuities, such as levels of pebbles, slope mostly towards the entrance of the cave, i.e., in opposite direction of the upper complex. some sedimentary structures, as flowstones located under a vertical chimney, in which there is an alternation of calcitic levels and thin levels of red soil sediments, would suggest that at least part of the material present within the breccia could come from karst cavities located above, as the occurrence of vertically-developed cavities in all the karst systems of the area seems to indicate. the reddish clayey matrix (munsell color: dry 5yr 6/6, moist 4/6) clearly represents sediments transported from outside the cave by the erosion of terra rossa type paleosols, perhaps of hapludalfs, hapludults and fragiudalfs type (magaldi & sauro, 1982). the main entry routes of the soil sediments were along the underground karst network, which consists of both vertical and sub-horizontal cavities. the cementation of the sediment is discontinuous: alternating portions of the breccia are extremely hard and others are rather fragile. in some parts, the absence of sedimentary structures suggests the occurrence of solifluction episodes during the deposition. probably, the most singular aspect of the sediments of the lower complex (lmpsc, in fig. 4) is the presence of thousands of small pebbles, mostly limefig. 4 sketch of the section of buso della fadanana, of the related rock wall and of the main sedimentary complexes filling the cavity (the scale both horizontal and vertical is the same and it is indicative). 78 sauro u. & zorzi f. � �� � � stone, dispersed in the reddish matrix, or concentrated to form sub-horizontal levels or lenses. 3. lithology of the small pebbles of the lower complex to better understand the lithology of the pebbles and their possible origins, two different approaches were carried out: (a) observations under the polarizedlight microscope of thin sections from 3 representative reddish breccia bulk samples; (b) x-ray powder diffraction (xrpd) of the red matrix and about 20 pebbles, (divided by color) from the same 3 samples. size and shape of clasts in the reddish breccia are heterogeneous, but there is a fraction of the pebbles that is widespread and often concentrated in small beds (fig. 5). these pebbles have a size range from of 0.5 cm to 1.2 cm, generally rounded to well-rounded ellipsoidal, flattened ellipsoidal, or discoidal in shape. clasts with angular and non-spherical shape are also present and their size ranges from 1 mm to 5 cm or more; most of them are fragments of flowstones (especially the larger clasts), bone fragments, micritic limestones and cherts. the sections and the thin sections of the reddish breccia after resin impregnation (fig. 6) revealed a wide lithological variety of the clasts, mainly from carbonate rocks. all clasts are floating within fine-grained or clay matrix (with a size <10 micron), rich in fe oxides. most of the pebbles are attributable to the geological formations of the lessini area (bosellini et al., 1967) (fig. 7). micritic limestones, grainstones and wackestones with ooids, peloids, crinoids and bivalves are very common and can be related to the jurassic formations. many pebbles are cherts and micritic limestone with the typical paleontological content (calpionellids, radiolarians, globotruncanae) of cretaceous formations. also, grainstone-packstone facies with foraminifera and echinoderms are frequent and they can be related to cenozoic formations. some pebbles are clearly exotic, as they are of metamorphic origin: mica-schist, quartz-schists/gneiss and serpentine-schists (fig. 6). it is also possible to macroscopically recognize some of the lithologies described above: jurassic limestones are grey, cherts are pure white with a black or brown external rim, serpentine-shists are pale green, mica-schists and quartz-schists/gneiss are dark grey or almost black. x ray powder diffraction analyses (xrpd) were carried out on pebbles and matrix of the reddish breccia using a panalytical x’pert pro diffractometer, equipped with co anode, bragg brentano hd mirror, sample spinner and solid state detector (x’celerator). the xrpd analysis of the clay matrix (fig. 8) shows a mineralogical composition typical for a soil: the main phases are smectite (montmorillonite-like), quartz and calcite and the minor phases are muscovite/illite, kaolinite goethite and hematite. most of the pebbles (with colors: grey, pale gray, 79 fig. 5 block of the breccia with a pebbles level. in the center of the breccia there is a 5 cm bone fragment and below there is a 7,5 cm flowstone fragment. problematic karst fillings of late lower pleistocene age in a cave of the monti lessini …. �� � � � � fig. 6 sections: a) section with carbonatic clasts; b) section with carbonatic clasts and metamorphic clasts (green and black clasts). pebbles thin sections under crossed polarizers: c) pebbles of micritic limestone; d) bluish pebbles of serpentinite and lighter pebbles of quartzite. scale bar 1 cm. 80 sauro u. & zorzi f. �� � � �� 81 fig. 7 pebbles thin sections under uncrossed polarizers: a) oolitic grainstone; b) micritic limestone with calpionellids; c) wackestone with globotruncana sp.; d) grainstone with cenozoic foraminifera and echinoderms. scale bar 1 mm. problematic karst fillings of late lower pleistocene age in a cave of the monti lessini …. �� � � white, beige and pale yellow) consist of calcite (fig. 9). some pure white pebbles are composed of quartz and moganite, a common mineralogical paragenesis in cherts (fig. 10). black or dark grey pebbles are composed of quartz and mica (quartzite and mica-schist) (fig. 11). pale green pebbles are totally made of antigorite, a mineral of serpentine group, the major constituent of serpentinites (fig. 12). serpentinites occur in different parts of the alps (mainly in the west alps) and they are associated with the penninic ophyolities. the larger serpentinites outcrops are present in the west alps (aosta valley, lanzo valley, susa valley, voltri massif), 200-300 km away from the buso della fadanana. the nearest sources of serpentinites (100-150 km away) are in the vizze valley (pfitschtal), fundres valley and ultimo valley (de vecchi & baggio, 1982; de vecchi, 1989). pebbles of serpentinites derived from these localities are also found in the fluvioglacial fan of the adige river not far form this area (linear distance of about 20 km) (bertola et al., 2013). 4. significance of exotic pebbles in the karst fillings part of the pebbles is certainly exotic in origin (fig. 5). here we consider exotic both the pebbles made up by lithologies not present in this mountain group, and the pebbles consisting in lithologies not existent in the karst system, although present in some areas of the lessini mountains. it should be emphasized that the red clay matrix and the pebbles must belong to different environments. in fact, the small limestone pebbles are not present in the clay paleosols of the external environments, since these are completely decalcified. it is also evident that the flowstone fragments and the carbonate cement of the breccia are the results of processes that have taken place inside the cave, during and after the emplacement of the sediments described above. the occurrence of exotic pebbles in the karst systems is not rare. in the northern calcareous alps, dispersed on the surface or inside the karst fillings pebbles of siliceous rocks with diameters of a few centimetres can be found. they are called “augenstein” for their dimensions similar to that of an eye (fink, 1975; frisch et al., 2002). similar pebbles also occur in some dolomitic plateaux, such as fanes, sennes and fosses (bini et al., 1990, 1997) and in the slovenian alps (audra et al., 2007). exotic pebbles, mostly of siliceous rocks of a relatively large size range (between millimetres and several decimetres) have been found also on the plateau of the berici, to the sse of the lessini mountains (sauro, 2002, 2005; sauro & ferrarese, 2016). 82 fig. 8 xrpd profile of the clay matrix. legend: sm=smectite, m=muscovite/illite, k=kaolinite, qz=quartz, cc=calcite, g=goethite, h=hematite. fig. 9 xrpd profile of grey pebbles. � fig. 10 xrpd profile of white chert pebbles. sauro u. & zorzi f. �� � � (benedetto sala, personal communication). these paleontological remains could be attributed, according to their excellent state of preservation, to the hunting and transport by birds (andews, 1990; denys c., et al, 2017; laudet f., selva n., 2005). probably, the birds used, as diurnal refuges, one or more cavities above the buso della fadanana, and were transporting remains of preyed animals or regurgitating their wads containing small bones. the deposits originated by these processes have been, later, partly removed and re -deposited in the buso de la fadanana as sediments. 6. discussion and conclusions the upper sedimentary complex (lhasc in fig. 4), rich in archaeological recent holocene finds (late neolithic and copper age), is the result of repeated episodes of frequentation by man, with reworking of sediments in relation to periods of use of the cavity for burial, alternating with periods of use as a dwellings site. the accumulation of these sediments is the result of human impact on the surrounding environment during protohistoric and historic times (sauro et al. 2007). considering the cave as a sedimentary trap, the sedimentation gap of about 0.8 1.0 myr, between the there are three possible general explanations for the origin of the exotic pebbles: i) they have been transported and displaced in the area by morphodynamic agents, such as ancient glaciers and/or watercourses; ii) they belong to a completely eroded geological formation, some elements of which have been trapped in the karstic environment; iii) they are the result of "ecofacts" caused by animals. thus, in the case of the dolomites it is known that the pebbles come from a recent geological formation, of which remains a small strip, trapped within a tectonic structure. instead, in the case of the berici mountains, the presence of exotic pebbles has been explained as linked to the activity of a large river, which could have flattened the “plateau” surface by fluvial abrasion and then entrenched its meanders inside the uplifting relief, before the messinian episode of desiccation of the mediterranean (sauro, 2002, 2005). the case of the pebbles of the buso della fadanana lower complex (lmpsc, fig. 4) is different from those previously described for the reduced dimensional range of the pebbles and for the predominance of lithologies referring to soluble rocks completely missing in the other cases described above. therefore, these pebbles could not go through large-scale transport processes by water, that would have caused their dissolution. according to us, a reasonable explanation is that these pebbles are "ecofacts", i.e: pebbles transported by the birds which use to swallow them to help digestion, then to expel them in the form of boluses or excrements (wings, 2004, 2007; laudet f., selva n., 2005; rosin & kwiecinski, 2011; denys c., et al, 2017). 5. the fauna of the lower complex the fauna of the “lower complex” (lmpsc in fig. 4), still under study, contains erinaceomorpha, several soricomorpha among which beremendia sp., chiroptera, a primate, macaca sylvanus, a large sciurid, a glirid, and several arvicolids among which mimomys savini, clethrionomys sp., pliomys episcopalis, pliomys coronensis, dinaromys sp., microtus arvalidens, microtus nivaloides. the small mammals assemblage is characterized by late biharian species: mimomys savini and microtus arvalidens (sensu fejfar ed heinrich, 1990) and m. nivaloides, and the absence of the small m. pusillus and of allophaiomys. the mimomys savini zone corresponds to the large mammals slivia faunal unit, referred to the reversal magneto-stratigraphic sequence between the jaramillo subchron and the brunhes chron (0,78-0,99 ma) (sala & masini, 2007; masini & sala, 2011) 83 fig. 11 xrpd profile of black pebbles. fig. 12 xrpd profile of pale green pebbles. � problematic karst fillings of late lower pleistocene age in a cave of the monti lessini …. �� � � upper and lower sedimentary complex, entails important remarks. since the buso della fadanana lacks loesslike sediments, recognized in other caves of the area, it is possible that the cavity has been sealed by the cone of large collapsed blocks (sbcb, in fig. 4) until recent holocene. a detailed sedimentological study of the sediments of the lower complex has not been carried out yet, and the excavations have involved only the superficial part of such complex, thus only preliminary hypotheses may be developed about the occurrence of pebbles coming both from local geological formations and from lithologies typical of remote areas (alto adige alps or even the western italian alps; but pebbles made up by similar lithologies are present also in the not far fluvial and till deposits of the adige river and garda moraine amphitheatre). as we have seen, the possible hypotheses about the origin of exotic pebbles are: i) the pebbles could have been transported and displaced in the area by morphodynamic agents, such as ancient glaciers, and/or watercourses; ii) the origin of the pebbles is a geological formation of the area, now completely removed by erosion, constituted by a deposit of pebbles from local and exotic provenience; such pebbles were reworked within the underground karst system, until their emplacement in the described sediments; iii) the presence of pebbles is expression of "ecofacts" of animal origin: birds could have swallowed the pebbles to aid digestion, passively transporting them and subsequently expelling them in boluses as pellets, or in excrements. the first hypothesis seems unlikely, because glacial or fluvioglacial deposits are not known in the area (the nearest local glacial deposits are about 8 km north, and consist only of carbonate rocks; the nearest till deposits of the adige system are located more than 10 km east and in different geomorphological contexts), and, in the case of several episodes of reworking, most of the pebbles, formed by soluble rocks would have been dissolved, and besides, based on natural morphodynamic processes, it is very difficult to explain the narrow dimensional range of the pebbles, as well as the fact that most of them are exotic in the context of this local karstic basin. with reference to the second hypothesis, the materials from which the pebbles originate could have been a geologic formation now completely eroded (cenozoic clastic formation of coastal or continental environment related to the lifting and erosion of the inner alps); the metamorphic pebbles of the cenozoic clastic formation could derive from the erosion of exposed rocks of alto adige alps, because ophiolite (serpentine) and gneiss pebbles from penninic units of tauern window already started to be eroded and redeposited by around 13 my (kuhlemann, 2006 and brugel, 1998); nevertheless this hypothesis implies particular conditions: the cenozoic deposit had to be well sorted and loose because the pebbles in the lower complex breccia are always separated and the pebbles reworking had to be very low, otherwise carbonate pebbles should be missing. therefore, at the moment, the third seems to be the only one hypothesis capable of explaining the presence of pebbles in this context and with the features illustrated. the association of animal bones and pebbles is perhaps due to the presence in this rock wall of different environmental niches, frequented by several species of birds: both predatory birds and other birds (as: vultures, eagles, owls, ravens, etc), which may have transported animal remains as food resources; beside this, some birds, not necessarily of the same species of those related to the presence of bones of mammals, could have swallowed up and then expelled the pebbles in the karst cavities; the pebbles' origin areas could have been the nearby torrent beds of the valleys of the lessini mountains, and, for the pebbles in metamorphic and crystalline rocks, the riverbed and the fluvioglacial fan of the not far adige river (linear distance of about 20 km). the extraordinary abundance of small pebbles could, perhaps, be explained by the preferential choice of cavities open on this rock wall by birds for very long time intervals, of the order of several tens of thousands of years. it should, however, be underlined that the described sediments have unique features, very problematic and not described until now in other alpine karst areas, and that further excavations could, perhaps, help to clarify interesting aspects of the paleoenvironmental evolution of this mountain area. acknowlegements the authors heartily thank benedetto sala for basic information about the faunal association and its chronology (personal communication). thanks also to the anonymous referees for the suggested improvements. references andrews p. (1990) owls, caves and fossils. natural history museum publications, london, pp. 231. audra p., bini a., gabrovsek f., häuselmann, p. hobléa f., jeannin p.y., kunaver j., monbaron m., šušterši� f., tognini p., trimmel h., wildberger a. (2007) cave and karst evolution in the alps and their relation to paleoclimate and paleotopography. time in karst, postojna 2007, acta carsologica, 36/1, 69-75. bertola s., broglio a., cristiani e., de stefani m., gurioli f., negrino f., romandini m., vanhaeren m. (2013) la diffusione del primo aurignaziano a sud dell’arco alpino. preistoria alpina, 47, 17-30. bini a., meneghel m., quinif y., sauro u., siorpaes c. (1990) discovery of quartz pebbles on summit surfaces in the altopiani ampezzani dolomites, ne italy). acta carsologica, xix, 197-206. bini a., meneghel m., sauro u. (1997) karst geomorphology of the altopiani ampezzani. zeitschrift für geomorphologie, supplementband 109, 1-21. bosellini a., carraro f., corsi m., de vecchi g.p., gatto g.o., malaroda r., sturani c., ungaro s., zanettin b. (1967) note illustrative della carta geologica d’italia alla scala 1:100.000, foglio 49, “verona”. servizo geoleologico d'italia, pp. 61. denys c., stoetzel e., andrews p., bailon s., rihane a., huchet j. b., fernandez-jalvo y., laroulandie v. (2017) taphonomy of small predators multi-taxa 84 sauro u. & zorzi f. �� � � accumulations: palaeoecological implications. historical biology. de vecchi g.p. (1989) considerazioni sul pennidico dei tauri (settore italiano). studi trentini sci. nat., acta geol. 65, 179-94. de vecchi g.p., baggio p. (1982) the pennine zone of the vizze region in the western tauern window (italian eastern alps). boll. soc. geol. it., 101, 89116. fejfar o., heinrich wolf-dieter (1990) muroid rodent biochronology of the neogene and quaternary in europe. in lindsay e.h., fahlbusch v., mein p. “european neogene mammal chronology”. plenum press, new york, 91-117. fink j. (1975) changes in climate and landforms in the eastern alps. a. acd. brasil cienc. 47, supl. 327336. frisch h., kuhlemann j., dunkl i., székely b., vennemann t., rettenbacher a. (2002) dachsteinaltfläche, augenstein-formation und höhlenentwicklung die geschichte der lezten 35 millionen jahre in den zentralen nördlichen kalkalpen. die höhle, 53, 1, 1-36. laudet f., selva n. (2005) ravens as small mammal bone accumulators: first taphonomic study on mammal remains in raven pellets. in palaeogeography, palaeoclimatology, palaeoecology, volume 226, issues 3–4, 2005, pages 272-286. magaldi d., sauro u. (1982) landforms and soil evolution in some karstic areas of the lessini mountains and monte baldo (verona, northern italy). geogr. fis. dinam. quat., 5, 82-101. masini f., sala b. (2011) considerations on an integrated biochronological scale of italian quaternary continental mammals. il quaternario, italian journal of quaternary sciences, 24(2), 193-198. mégnien c. (1964) observations hydrogéologiques dans le sud-est du bassin de paris. mém. b.r.g.m., 25, pp. 288. rosin z.m., kwiecinski z. (2011) digestibility of prey by the white storck (ciconia ciconia) under experimental condition. ornis fennica, 88, 40-50. sala b., masini f. (2007) late pliocene and pleistocene small mammal chronology in the italian peninsula. quaternary international, 160, 4-16. salzani l. & sauro u. (1986) rinvenimenti archeologici nella grotta squaranto, o "buso del beco", presso corbiolo. quaderno culturale la lessinia ieri oggi domani, 73-82. sauro u. (1973) il paesaggio degli alti lessini. studio geomorfologico. museo civ. di st. nat. di verona, mem. f. s., 6, pp.161. sauro u. (1974) aspetti dell'evoluzione carsica legata a particolari condizioni litologiche e tettoniche negli alti lessini. boll. soc. geol. it., 93, 945-969. sauro u. (1999) towards a preliminary model of a karst geo-ecosystem: the example of the venetian fore-alps. karst 99, etudes de géographie physisque, suppl. n°. 28, cagep, université de provence, 165-170. sauro u. (2002) the monti berici: a peculiar type of karst in the southern alps. acta carsologica, 31 (3), 99-114. sauro u. (2005) the monti berici: guide of the fieldtrip. geogr. fis. din. quat., suppl. vii, 367-372. sauro u., ferrarese f. (2016) montagne in evoluzione e terremoti: alcuni casi nelle prealpi venete, trentine e gardesane. de rerum natura, numero monografico speciale, museo di storia naturale e archeologia montebelluna, pp.100. sauro u., salzani l., salzani p., fasani l., cozza f. (2007) ritrovamenti dell’età del rame sui lessini. indagini archeologiche in due grotticelle del vajo di squaranto (bosco chiesanuova). bollettino del museo civico di storia naturale di verona, 31, geologia paleontologia preistoria, 99128. wings o. (2004) identification, distribution, and function of gastroliths in dinosaurs and extant birds with emphasis on ostriches (struthio camelus): dissertation zur erlangung des doctorgrade (dr.rer.nat.) mathematisch-naturwissenshaflichen fakultät der rheinischen friedrich-wilhelmsuniversität bon, pp. 187. wings o. (2007) a review of gastrolith function with implication for fossil vertebrates and a revised classification. acta palaeontol. pol., 52(1), 1-16. 85 ms. received: october 1, 2016 final text received: october 3, 2017 problematic karst fillings of late lower pleistocene age in a cave of the monti lessini …. �� � � � 86 imp.orrš& submerged geomorphosites in the marine protected areas of sardinia (italy): assessment and improvement paolo orrù1, valeria panizza2 & antonio ulzega1 1dipartimento di scienze della terra, università di cagliari 2dipartimento di teorie e ricerche dei sistemi culturali, università di sassari abstract: p. orrù et al., submerged geomorphosites in the marine protected areas of sardinia (italy): assessment and improvement. (it issn 0394-3356, 2005). inside the studies conducted around the theme of the improvement of the italian geological and geomorphological heritage, studies undertaken in the ambit of different research projects and working groups, we want, with this work, to experiment and to verify the applicability of the methodologies of assessment and census of the sites of geological and geomorphological interest in submerged areas. this with the aim to gather the most greater number of possible data on the characteristics of the physical submerged resources in protected sea areas, both for scientific purpose and for a possible fruition by the public of the scuba divers. further intent is, in fact, that to drive the "tourist" toward a more aware and global knowledge and perception of the underwater world, in all the aspects of any cultural interest, and not only for those aspects tied up to the complex of the living organisms. the experimentation of the methodology and the study on two protected sea areas of the island of sardinia (italy) is proposed: the protected sea area of c. carbonara and the protected sea area of c. caccia. riassunto: p. orrù et al., geomorfositi sommersi nelle aree marine protette della sardegna (italia) . (it issn 0394-3356, 2005). all’interno degli studi condotti intorno al tema della valorizzazione del patrimonio geologico e geomorfologico del territorio italiano, studi intrapresi nell’ambito di diversi progetti di ricerca e gruppi di lavoro, si è voluto, con questo lavoro, sperimentare e verificare l’applicabilità delle metodologie di valutazione e censimento dei siti di interesse geologico e geomorfologico in aree sommerse. questo al fine di raccogliere il maggior numero di dati possibili sulle caratteristiche delle risorse fisiche sommerse di aree marine protette, sia a fini puramente scientifici che per un’eventuale fruizione rivolta al pubblico dei subacquei. ulteriore intento è, infatti, quello di guidare il “turista” verso una percezione e conoscenza più consapevole e globale del mondo subacqueo, in tutti gli aspetti di interesse culturale, inteso nel senso più ampio, e non solo per gli aspetti legati al complesso degli organismi viventi. si propone lo studio e la sperimentazione della metodologia a due aree marine protette dell’isola di sardegna (italia): l’area marina protetta di c. carbonara e l’area marina protetta di c. caccia. key words: geomorphosites, continental shelf, palaeo-shorelines, tourism, sardinia. parole chiave: geomorfositi, piattaforma continentale, paleo-linee di riva, fruizione turistica, sardegna. il quaternario italian journal of quaternary sciences 18(1), 2005 volume speciale, 167-174 1. foreword the present paper has the purpose to extend the already very well established growing interest in geological and geomorphological heritage of continental contexts also to the submerged areas. the marine environment is normally frequented for its biological aspects, and even experienced divers generally have no knowledge at all of the physical aspects, such as geology and geomorphology, that sustain underwater life. more and more attention has been focussed on geological and geomorphological heritage in the past few years, leading to several researches in the framework of conservation projects, both at administrative and at scientific level involving national and international research groups. associations such as progeo (european association for the conservation of the geological heritage) have the purpose of promoting the knowledge and the conservation of the geological heritage at european level, and started the compilation of a list of european geosites. the project geosites of the international union of geological sciences (iugs) started shortly after, with the scope of making an inventory for the collection of all data on the most important geological sites of europe and of the world. this last project has stimulated the formation of other working groups and research projects all aiming at elaborating and improving methodologies for the inventory, selection and assessment of geological and geomorphological sites. this research fits in the framework of such studies that have developed also in italy in the past ten years, and has been performed inside the national project cofin 2001-2003 “geosites in the italian landscape” and in the working group “geomorphosites” of the international association of geomorphologists (iag). the aim is to make the enjoyment of the submerged resource less controlled by emotion and more by awareness through the realisation of guided diving routes. in fact, the submarine environment, more than the terrestrial one, is typically characterised by an emotional approach. to have a complete interpretation of the landscape one needs decoding instruments (bini & poli, 2003), thus capable of guiding the awareness of the entire system through its most significant variables once an evolutional context is identified (panizza & piacente, 2003). a scientific approach aiming to the enjoyment of 168 p. orrù et al. the submerged geomorphological landscape is proposed in this paper taking as example a selection of sites. a geomorphosite, according to panizza m. (2001) is “a landform with particular and significant attributes that qualify the site as part of the cultural heritage (latu sensu) of a territory”. according to this definition the value of a geomorphosite comprises also their relationship with other significant components of their environment, such as biological, historical, archaeological etc. the preliminary study, analysis and census of the most significant sites is followed by the realisation of guided diving routes that give the opportunity to enjoy the different aspects of geology, geomorphology, biocoenosis etc.. similar guided diving routes are lacking in other european marine protected areas where biological themes are normally put in evidence, leaving geology and geomorphology as simple “containers”. it is our purpose to give a central role to these last aspects for the interpretation of the submarine environment that, in many cases, is much more conservative than the terrestrial one. in the submerged environment, in fact, relict landforms, testifying past geological and geomorphological events or paleo-environments, and direct consequences of human interaction are usual better conserved than in a continental environment. in planning submarine diving routes one needs to consider the technical preparation of the divers, differentiating routes according to the different diver’s licences. thus, the choice of the sites is limited to the depth of 40 meters, on the continental shelf, where the variety of present landforms, derived from submarine processes and in equilibrium with the present sea level, and relict landforms, related to continental processes or in equilibrium with sea level low stands, is highest. also the biological aspects are the most interesting and varying in the same ambit, because directly correlated to the variety of the local morphological conditions. the past negative experiences documented in marine reserves of the mediterranean (ribera siguan, 1990; ramos, 1990) and in the tropics (hawkins & roberts, 1993) suggest to devote special attention to the aspects related to the capacity of absorbing tourist presence, the so-called carrying capacity, of certain extremely vulnerable submarine environments (agardy, 1993; di gregorio, 1993). two protected marine areas of sardinia have been chosen for the experimentation of the methodology: the marine protected areas of capo carbonara (south-east sardinia) and of capo caccia (north-west sardinia) (fig. 1). both areas are very different for what concerns geology and present and relict geomorphology. these differences, creating a wide variety of micro-environments, also cause different biocoenosis, adding interest and value to the single sites. 2. methodology 2.1 surveying methods the mapping of the landforms and of the biocoenosis (peres & picard, 1964) has been done by the integrated overlapping of data acquired with different methods: for the shallow underwater environments remote sensing data have allowed to distinguish the limits of the submerged beaches and the rocky coastal abrasion platform up to a depth of 10 meters. satellite images also allow to map the areas occupied by posidonia oceanica up to 20 meters of depth. the survey of submerged landforms with geophysical techniques has involved the proximal continental shelf at depths between 20 and 40 meters, using vertical and side scan sonar technology. these remote sensing data have been verified by direct underwater surveys. the specific oceanographic survey has been planned on the ground of the nautical maps of the italian “istituto idrografico della marina” at scale 1:100.000 and 1:50.000. the main problem in surveying and mapping submerged geomorphosites is the construction of reliable and detailed bathymetric maps in scale 1:10.000, maps that can be also the basis for the tourist and diver’s enjoyment. the following step is the preparation of a geomorphological map that represents the coast and the continental shelf using criteria and legends proposed by the geological service of italy for the geomorphological map of italy in scale 1:50.000. fig. 1 location of the study areas. localizzazione delle aree di studio. 2.2 selection and cataloguing by means of a methodology of selection, study and cataloguing of the geomorphosites, adopted in the framework of the specific research projects mentioned earlier in this paper, several sites have been identified in both study areas. the considered sites possess one or more attributes of scientific value as an essential condition for their choice (panizza 1988; panizza & piacente, 1989; carton et al., 1994; panizza & piacente, 2003). the sites, because of the genetic characteristics of the internal continental shelf, practically always have a high paleo-geomorphological significance besides their ecological valence related to the hosted biocoenosis. in both study areas sites with the following significant valences have been chosen (panizza & piacente, 1989): model of geomorphological evolution (wave notch, karstic caves, slope of the cliff etc.); didactic exemplarity ( fault cl iff, abrasion platform, landslides, sand waves, etc.); paleo-geomorphological testimonial (inselberg and tor formed in continental environment, beach rocks, tafoni, carbonate precipitation forms such as stalactites and stalagmites, etc.); ecological valence (almost vertical walls, tafoni and karstic cavities with development of biocoenosis with porifera and coelenterata, isolated reliefs with concentration of big lair fish). the sheet file, elaborated in the framework of the national project “geosites in the italian landscape” and realised by the national geological service and the centre of documentation on geosites of genova university, has been used for the cataloguing of the sites (fig. 2). this sheet file, being made for the documentation of continental geosites, has been adapted and revised in some of its contents. the location of the site can be done referring to the new edition of the topographical map of italy if the detail of bathymetry is sufficiently reported, otherwise the bathymetric maps of the italian “istituto idrografico della marina” or other bathymetric documents can be used as long as the type of map is referred to in the sheet file. maximum and minimum depth are indicated to know the relative depths to which one has to dive to appreciate the qualifying elements of the chosen site. given the strict interdependence between biocoenosis and geodiversity, this last intended as the variety of morphological and lithological micro-conditions, the submarine geomorphosite will present, in the majority of cases, a secondary naturalistic or ecological interest indicated in the sheet file in field c. other fields of compilation, such as the field i related to the type of soil in the original sheet file, have been enlarged to be able to contain the necessary information of certain marine environments, such as the type of seafloor: sandy, pebbly, outcropping rocks etc.. 3. marine protected area of capo carbonara the marine protected area of capo carbonara is located in the south-eastern most part of sardinia and is comprised in the commune of villasimius in cagliari province. the promontory of capo carbonara closes the gulf of cagliari to the east with the islets of cavoli and serpentara. the crystalline basement of south169submerged geomorphosites in ... east sardinia is tectonically strongly deformed according to nw-se lineations of alpine age (cherchi & montadert, 1984). the same tectonic imprint strongly influences the coastal and the submarine landscape. the development of the coastline is characterised by iso-oriented promontories, dominated by capo carbonara, all of which are aligned along main veins (brotzu & morbidelli, 1974); the promontories of the eastern sector comprise a system of small pocket beaches. the continental shelf is characterised by an eastern sector controlled by tectonic n-s movements and a western sector guided by nw-se alignments, separated by the promontory of capo carbonara. the first researches on the south-eastern continental shelf of sardinia concerned the types of margins and the characteristics of the sedimentary units (lecca et al., 1979). the head of the simius canyon rises up on the border of the continental shelf, southeast of the islet of cavoli, along a nw-se direction (lecca et al., 1998). ancient coastlines, recognisable in beach rocks, have been found at depths of 45 meters (ulzega et al., 1984; orrù et al., 1997). the submarine landscape of the villasimius area is dominated by the outcropping of granite rocks and associated magmatic differentiated rocks; the morphological asset is organised in a system of irregular surfaces that develop at different depths. an ancient, irregular and gently seawards inclining surface of continental erosion is visible at depths between 40 and 60 meters, characterised by relict landforms such as tor and inselberg on the shallows of berni, of libeccio and on the isolated relief south of the islet of serpentara. these landforms are difficult to date, even though their state of evolution does testify very long time of formation, probably related to a pre-quaternary period characterised by warm-wet climate and a much lower sea level than today. more rapidly evolving continental landforms, presently underwater, are the large-sized tafoni with chambers characterised by sub-spherical roofs; these landforms can frequently be found in the whole area at depths comprised between 15 and 30 meters. an irregular erosion surface fossilised by aeolian sandstones with cross-bedding, from a sedimentological point of view similar to the aeolian deposits of the actual coastline, is reported at 15 meters depth in the southern bay of the islet of cavoli (palmerini, 1967). other parts of almost horizontal surfaces with homogeneous characteristics are concentrated in some precise bathymetric intervals: an abrasion surface at average depth of 25 meters is reported at capo boi, in the shallows of s. caterinia, of libeccio and of berni. active marine abrasion surfaces at depths between 1 and 3 meters border all the main promontories of the study area. the veins of acid rocks arise from these surfaces due to differential erosion. many sandy-conglomerate beach-rocks have been preserved on the seafloor of villasimius both on the proximal and the external continental shelf: these are ancient shorelines related to the holocene sea level rise. the deepest of these is located to the north of the islet of serpentara, at 45 meters depth; this ancient shoreline is particularly important because it can be retraced along most of the eastern continental shelf of 170 sardinia right up to the strait of bonifacio (ulzega et al., 1984). the posidinia oceanica meadow colonises most of the upper continental shelf of carbonara for a total surface of over 40 square km. coralligenous or precoralligenous biocoenosis, dominated by gorgonia, coelenterata in general, porifera and calcareous algae facies, develop especially on the cliffs or on isolated blocks. the deepest biocoenosis are represented by carbonate constructions of algae with pseudolithophyllum expansum. the littoral bench of the vermetid dendropoma is the only animal biological construction represented in the area and found in the northern part of the islet of cavoli; this gastropod formation is very important being an indicator of the most recent variations of sea level. this is the northernmost occurrence of this kind of biological constructions along the italian coasts; similar formations are well fig. 2 excerpt of the sheet file for the inventory of the italian geosites, compiled for the cataloguing of the cave of nereo (c. caccia, alghero). stralcio di scheda per l’inventario dei geositi italiani, compilata per la catalogazione della grotta di nereo (c. caccia, alghero). p. orrù et al. 171 developed along the northern coasts of sicily. the submarine surveys have allowed to map the main biotic communities in detail (meinesz et al., 1983), putting also in evidence the tight existing interrelations between geomorphological characteristics, distribution of morpho-sedimentary units and main benthic biocoenosis. in the framework of the geomorphological context of the continental shelf of carbonara the site named “shallow of berni” has been selected according to the previously described criteria. this isolated almost surfacing granite relief is located offshore the simius bay, in an axial position respect to the channel between capo carbonara and the islet of cavoli. the shallow of berni is a tor represented by a central column of 15 meters height, circled by residual peaks and accumulations of big sub-spheroidal tafoni (fig. 3). the ancient, gently seawards inclining continental erosion surface, characterised by a biocoenosis of posidonia oceanica and coralligenous platform reefs with red algae (pseudolithopyllum expansum), locally crops out at the foot of the relief. the dominating valence of this selected geomorphosite is the paleo-geomorphological and paleogeographical one, related to the evolution of a broad continental erosion surface now submerged. also the biological valence related to the strong currents and to the related circulation of nutrients is very important. another important aspect is related to the historical and cultural importance of this site, being a privileged embarkation point for horses and herds from sardinia to other beaches of the mediterranean starting from the roman imperial period; this practice continued during the medieval and arrived up to the xix century. nowadays an exceptional concentration of shipwrecks and ceramics of different ages together with animal remains are found. 4. protected area of capo caccia the promontory of capo caccia is located in northwest sardinia, in the so-called nurra of alghero, in the territory of the commune alghero in sassari province. is characterised by high cliffs that arrive at heights of 170 meters a.s.l., forming, in its southern extremity, a n-s directed promontory that closes the broad gulf of porto conte to the southwest. capo caccia is part of the regional natural park of porto conte, instituted in 1999 and comprising, aside the promontory, the entire peninsula, with the hilly complex of monte timidone (361 m), the bay of porto conte and, towards the east, the vast territory that extends from monte doglia (436 m) up to the rocky promontory of punta giglio. the marine protected area of national interest “capo caccia-porto conte-punta giglio” has been instituted recently and includes the near shore seafloor of the regional natural park up to a depth of 50 meters. the whole mesozoic carbonatic sequence crops out in the area, except for some local quaternary deposits and the permian-triassic alluvial plain sediments (verrucano sardo, pecorini, 1962) that characterise the coastal strip north of cala viola. this mesozoic sequence represents a general transgression of this part of sardinia with the deposition of carbonate platform sediments characterised by limestones, dolomitic limestones, marly limestones and marls. the platform sedimentation is interrupted by a bauxite deposition during meso-cretaceous, representing a period of emersion and thus continental tropical or sub-tropical warm-wet climatic conditions (carmignani et al., 2001). the thick carbonatic sequences of neritic environment of upper cretaceous, attaining their maximum thickness of 140 meters at capo caccia, evidence a general return to typical marine conditions (carmignani et al., 2001). the main tectonic alignments mostly of tertiary age are directed n-s and nwse (cherchi & montadert, 1984) and guide the evolution of the morphologies characterised by scarps in the internal areas and also control the high cliffs that are typical of the entire coastal perimeter of capo caccia (federici et al., 1999; ginesu, 1999). from a geomorphological point of view the whole area is characterised by a wide variety of landforms deriving from intense and differentiated fossil and still active processes of karst dissolution. for what concerns the fig. 3 simius bay – berni shallow. picture of the bottom at -15 m. residual pinnacles and sub-spherical blocks on the border of a tor relief; a network of joints in which archaeological remains are concentrated and conserved develops at the foot of the ridge. baia di simius secca dei berni . foto del fondo a -15 m. guglie residuali e blocchi sub-sferoidali ai bordi del rilievo a tor; alla base delle cornici si sviluppa un reticolo di diaclasi, luogo di concentrazione e di conservazione dei materiali di interesse archeologico. submerged geomorphosites in ... 172 promontory of capo caccia the impressive cliffs that characterise its entire profile and continue along the whole western coast of the peninsula, reaching a height of 203 meters, show active processes of retreat and several levels of wave notches related to the quaternary sea level variations. many and complex natural caves are clearly visible along the calcareous cliffs, and many of these are accessible only by diving. a first karstic phase is related to the continental mesocretaceous period, enhanced by the wet and warm climatic conditions (federici et al., 1999). a paleokarst phase can thus be hypothesised along faults and discontinuities during cretaceous, before the upper cretaceous transgression and marine sedimentation (mucedda et al., 1997). other karst dissolution phases followed the first one in the geological and climatic history of sardinia, and the presence of many caves along the coast testifies a long-during dissolution enhanced by an intense underground circulation (ginesu, 1999). in this particular geological and geomorphological context the methodology for selecting and cataloguing geomorphosites has been directed towards the many submarine caves present along the cliffs of the capo caccia promontory. the nereo cave has thus been chosen, for its genetic characteristics, for its importance in the reconstruction of paleo-environments, for the variety and the differentiation of its ecosystems and for its potential to attract tourists, many of the attributes that can give value to this geological and geomorphological site (panizza & piacente, 2003). the nereo cave is located at the foot of the promontory of capo caccia, hosted in white and compact limestones of lower cretaceous in which many of the caves of the promontory are formed. the cave was discovered in 1957 by two local divers and has become famous especially for the presence of many colonies of red coral (corallium rubrum). today, unfortunately, this coral is present only in small groups in the less exposed sites of the cave (chessa et al., 1991). only recently the cave has been thoroughly explored and surveyed for a total development of more than 400 meters, along a complex series of chambers, tunnels and shafts. the nereo cave, that represents the biggest sea cave of the mediterranean, has 7 communicating entrances located at variable depths between 8 and 31 meters, of which only three can be defined as main entrances (mulas, 2000). the cave, in this case, has a mixed origin, being formed by a combination of karstic and marine erosion phenomena (chessa et al., 1999). the deepest entrance (-31 meters) opens towards the north, corresponding to the cala del sommergibile, and leads into a big chamber which floor is covered with rocks fallen from the roof and sandy patches. many tunnels start from here and lead towards the other two entrances, one to the west one to the south. the most external parts of these tunnels often show clear pebbles modelled by marine abrasion, sandy sediments and fragments of sea shells. from the biggest chambers and from the main branches departs a labyrinth of tunnels and fissures, not always accessible, some of which develop vertically (sumps) and open in subaerial and concretioned parts of the cave, with stalactites and stalagmites (mulas, 2000; chessa et al., 1999). these parts of the cave have been explored only very recently and are accessible only to expert and well equipped cave divers. also the western entrance, at 18 meters depth, leads into a very big chamber characterised by big blocks at the entrance forming a beautiful sight. from here one can proceed towards the south to gain the third entrance that has two openings one above the other, respectively at 9 and at 14 meters depth. one of the few remaining colonies of red coral can be seen in correspondence of this entrance, towards the left. the big blocks, with differing degree of biological colonisation, present at the different entrances are the proof that the cliffs are still retreating and subjected to sporadic rockfall. furthermore, a deep wave notch can be seen at the foot of these active cliffs. aside the evident valence of the cave as a model of geomorphological evolution, the dimensions of the littoral-karstic phenomenon and its relationships with the actively retreating of the cliffs, together with the paleo-geomorphological meaning of this site is of great value and significance. in fact, erosion forms related to the sea level variations and stalactite-stalagmite constructions with submarine and subaerial cements are well conserved. the presence of numerous colonies of coelenterata (ceriantus membranaceus e corallium rubrum), typical of sciophilous environments, gives this site also a great ecological valence. conclusions the tourist offer in marine protected areas and marine national parks in the mediterranean, especially in the submarine field, is related almost exclusively to the ecological valences and the value of the different submerged areas is essentially related to the level of biodiversity. exception is made for some protected areas of sicily, of greece and of turkey where cultural aspects dominate, related to the presence of important submerged archaeological resources. the submerged landscape has thus been relegated to the role of “container” for the other valences. in this paper a different role of the submerged landscape is put forward, following the recently introduced and proposed concepts (panizza, 2001; panizza & piacente, 2003; piacente & poli, 2003) and the application of new methodologies for the selection and the assessment of environmental assets with a high geomorphological relevance. the examples described in this paper, in fact, show that this submerged landscape explains itself in an autonomous way, by its own physical character of great suggestion and by its history and evolution visible in the mosaic of landforms and deposits that compose a geomorphological and paleo-geomorphological picture (fig. 4). also the potentiality expressed by the integration with biological and historical-cultural valences is of great interest. in making submerged geomorphosites enjoyable one has to keep in mind the risk of damaging these sites, especially in the case of very fragile landforms and microforms (tafoni and residual granite blades, wall concretions and stalactites in natural caves, etc.). it is thus very important to plan and control the visits on the basis of a detailed analysis of the carrying capacity of the sites. p. orrù et al. references agardy m. (1993) accomodating ecotourism in multiple use planning of coastal and marine protected areas. ocean and coastal management, 20, 219239. barca s. & di gregorio f. (1991) proposta metodologica per il rilevamento dei monumenti geologici e geomorfologici. boll. a.i.c., 83, 25-35, todi. bini m. & poli g. (2003) modelli e strumanti per “comunicare” la geologia. in “la memoria della terra la terra della memoria”, l’inchiostroblu edizioni, bologna. brotzu p. & morbidelli l. (1974) lineamenti petrografici e geostrutturali di un settore del sarrabus meridionale. atti acc. naz. lincei, ser. 8, 12, 1-78. carmignani l., oggiano g., barca s., conti p., salvadori i., eltrudis a., funedda a., pasci s. (2001) geologia della sardegna. note illustrative della carta geologica della sardegna a scala 1:200.000. mem. descr. carta geol. d'italia, 60, 1-283. carton a., cavallin a., francavilla f., mantovani f., panizza m., pellegrini g. b., tellini c. et al. (1994) ricerche ambientali per l’individuazione dei beni geomorfologici. metodi ed esempi. il quaternario, 7(b), 365-372. cherchi a. & montadert l. (1984) il sistema di rifting oligo-miocenico del mediterraneo occidentale e sue conseguenze paleogeografiche sul terziario sardo. mem. soc. geol. it. 24, 287-400. chessa l. a., vitale l. & scardi m. (1999) descrizione dell'ambiente sommerso con censimento e studio delle grotte sottomarine. in: protezione dell'ambiente e gestione delle risorse naturali, a cura di m. gutierrez. quad. ist. di studi politico-giuridici dell'univ. di pavia, 5, cedam chessa l. a., cossu a., milella i. & pais a. (1991) l'ambiente sommerso. in: falesie, grotte e praterie sommerse, amm. prov. di sassari, pizzi editore. di gregorio f. (1993) problemi di carryng capacity nelle aree costiere sensibili. atti del convegno internazionale "parchi marini del mediterraneo: problemi e prospettive" s. teodoro, 17/19 maggio 1991. olbia federici p. r., ginesu g. & sias s. (1999) lineamenti geomorfologici ed evoluzione recente del paesaggio nella nurra occidentale (sardegna nw). la fascia costiera di porto conte-porto ferro. in: protezione dell'ambiente e gestione delle risorse naturali, a cura di m. gutierrez. quad. ist. di studi 173 fig. 4 palaeo-geographical reconstruction of the capo caccia-punta giglio area and location of the nereo cave, based on the coastal and continental shelf geomorphological surveys. ricostruzione paleo-geografica dell’area capo caccia-punta giglio sulla base di indagini geomorfologiche costiere e in piattaforma continentale e localizzazione della grotta di nereo. submerged geomorphosites in ... politico-giuridici dell'univ. di pavia, 5, cedam. ginesu s. (1999) sardegna. aspetti del paesaggio fisico di un microcontinente, industria grafica poddighe, sassari. hawkins j.p. & robert c.m. (1993) the growth of coastal tourism in red sea: present a possible future effects on coral reefs. in proceeding of the colloquium on global aspects of coral reefs: health, hazards and history. f.l. university of miami, 385-391, miami. lecca l., lenaz r., leone f., rossi s. & ulzega a. (1979) la piattaforma continentale della sardegna sudorientale: indicazioni metodologiche e primi risultati. atti conv. p.f. oceanografia c.n.r. lecca l., panizza v. & pisano s. (1998) the sedimentary framework of cagliari basin: a plio-quaternary underfed rift basin in the southern sardinia margin. il quaternario, 11 (2), 301-318. meinesz a., boudouresque c. f., falconetti c., astier j. m., bay d., blanc j.j., bourcier m., cinelli f., cirik s., cristiani g., di geronimo i., giaccone g., harmelin j. g., laubier l., lovric a. z., molinier r., soyer j. & vamvakas c. (1983) normalisation des symboles pour la representation et la cartographie des biocenoses benthiques littorales de mediterranee. ann. inst. oceanogr., 59 (2), 155172, paris. mucedda m., loru r. & montanaro l. (1997) grotte di capo caccia. la celere editrice, alghero. mulas g. (2000) la grotta di nereo. in: www.geaspeleo.it a cura del grup espeleògic alguerès. oggiano g & virdis g. c. (1991) la varietà geologica e geomorfologia. in: falesie, grotte e praterie sommerse, amm. prov. di sassari, pizzi editore. orrù p., cocco a. & panizza v. (1996) rilevamento geomorfologico subacqueo del settore compreso tra capo boi e punta is cappuccinus, sardegna sud-orientale. atti conv. int. geol. subacquea, geosub 94, palinuro 8-10 giugno. mem. descr. carta geol. d'italia, lii, 163-176. palmerini v. (1967) nuovi lembi tirreniani lungo la costa di capo carbonara. rend. sem. fac. sc. univ. di cagliari, 37, (4), 1-16. panizza m. (1988) geomorfologia applicata. nuova italia scientifica editrice. panizza m. (1989) beni “geologici” e cultura del paesaggio, atti conv. intern. accad. naz. lincei, 2628/6/1989, 85-86. panizza m. (2001) geomorphosites: concepts, methods and examples of geomorphological survey. chinese science bulletin, 46, supp., 4-6. panizza m. & piacente s. (1989) geomorphological asset evaluation. proc. intern. geomorph., z. geomorph. n.f., suppl. bd., 87. panizza m. & piacente s. (2003) geomorfologia culturale. patron editore, bologna. pecorini g. (1962) nuove osservazioni sul permico della nurra (sardegna nord-occidentale). atti acc. naz. lincei, rend. cl. sc. fis. mat. e nat., 32, 377-380. peres j. m. & picard j. (1964) nouveau manuel de bionomie benthique de la mer mediterranee. rec. trav. stat. mar. endoume, 47, (31), 1-137. piacente s. & poli g. (eds.) (2003) la memoria della terra la terra della memoria. l’inchiostroblu edizioni, bologna. poli g. (ed.) (1999) geositi testimoni del tempo. regione emilia romagna. edizioni pendragon, bologna. ramos a. (1990) the marine reserve of nueva tabarca island: management aspects (alicante, spain). atti del conv. intern. sui parchi e le riserve marine del mediterraneo, s. teodoro, 28/30 aprile 1989. ed chiarella, sassari. ribera siguan m. a. (1990) parques y riservas marinas en espana. atti del conv. intern. sui parchi e le riserve marine del mediterraneo, s. teodoro, 28/30 aprile 1989. ed chiarella sassari. servizio geologico d’italia (1961) carta geologica d'italia a scala 1:100.000, f. 192 alghero. ulzega a., leone f. & orrù p. (1984) late quaternary sea-level evidence in sardinia the submerged beach-rock of serpentara. inter. sympos. on late quaternary sea-level changes and coastal evolution, mar de plata, argentina. 174 p. orrù et al. imp.dall'aglio& geomorfologia e popolamento antico nella media valle del fiume cesano (marcheitalia) pier luigi dall’aglio1, giuseppe marchetti2, olivia nesci4, luisa pellegrini3, daniele savelli4 & gilberto calderoni5. 1dipartimento di archeologia dell’università di bologna 2dipartimento di ecologia del territorio dell’università di pavia 3dipartimento di scienze della terra dell’università di pavia 4dipartimento di scienze della terra dell’università di urbino “carlo bo” 5dipartimento di scienze della terra dell’università di roma “la sapienza” riassunto: dall’aglio p. l., marchetti g., nesci o., pellegrini l., savelli d., calderoni g., geomorfologia e popolamento antico nella media valle del fiume cesano (marche, italia).( it issn 0394-3356, 2004) la presente ricerca propone uno studio integrato del territorio, con la sovrapposizione dei dati geomorfologici con quelli storico-topografici, allo scopo di definire le trasformazioni più recenti del paesaggio. l’area studiata ricade nella media valle del fiume cesano (versante adriatico dell’appennino marchigiano), per la quale sono state riconosciute numerose fasi fluviali a cui sono riconducibili vari livelli di terrazzamento fluviale. le analisi effettuate e le testimonianze rinvenute permettono di individuare, soprattutto a partire dai terrazzi del “3° ordine”, fasi deposizionali con regime a canali intrecciati, che si sono intervallate a fasi a canali meandranti. l’assetto fisico del territorio costituisce la base delle scelte insediative del popolamento antico dettate dalla necessità ora di difesa dall’eventuale nemico ora di coltivazione dei campi. in particolare si giustifica l’ubicazione dell’importante città romana di suasa sulla sommità del terrazzo pleistocenico, in destra cesano, con motivazioni di tipo storico e geografico. nel contesto dell’interazione uomo–territorio, rilevante significato assume il periodo caratterizzato da un sensibile deterioramento climatico, riferibile al v-vi sec. a.d.: gli eventi alluvionali, riconducibili a quel periodo, vengono collegati non solo al peggioramento climatico ma anche, probabilmente, allo spopolamento dell’area che comportò l’abbandono dei terreni coltivati e delle opere di controllo idraulico. si può pertanto affermare che, nell’area studiata, i suddetti eventi alluvionali, innescati da fattori naturali, furono notevolmente amplificati dall’attività umana. abstract: dall’aglio p. l., marchetti g., nesci o., pellegrini l., savelli d., calderoni g., geomorphology and ancient settlement in the middle cesano river valley (marche, central italy). (it issn 0394-3356, 2004). this paper reports the preliminary results obtained by comparing geomorphologic, historic and topographic data with the aim of highlighting the most significant geomorphic changes which occurred in the landscape configuration. the study area embraces the middle cesano river valley (adriatic side of the marche apennines), an area where distinct fluvial evolution stages pointed out by individual terrace levels have been identified. starting from the so-called “3rd order” terrace alluvium (upper pleistocene-holocene pp. in age), several cut-and-fill stages have been recognised on the basis of field evidence, 14c dating of wood remnants and archaeological findings. specifically, braid-plain aggradation stages characterise the most part of the upper pleistocene terrace alluvium, whereas both late-upper pleistocene and early holocene deposits and terrace-surface morphology hint at a flluvial activity related to an overall meandering channel pattern. it is only in post-roman times that braiding was at first restored and then replaced by entrenching single straight channels. analogously, it has been verified that the physical features of the territory strictly controlled the settlement of the ancient population. both historical and geographical constraints account for the location of the roman town of suasa atop a pleistocene terrace on the right side of cesano river. as for man-environment interaction, it is worth stressing that through the v-vi centuries a.d. a marked climatic cooling triggered an aggradation pattern in the river valley whose effectiveness was boosted because the population drop was obviously paralleled by a progressive abandonment of agriculture as well as by hydraulic workings. parole chiave: morfologia fluviale, geoarcheologia, suasa, fiume cesano, marche. keywords: fluvial geomorphology, geoarchaeology, suasa, cesano river, marche. il quaternario italian journal of quaternary sciences 17(2/1), 2004, 213-219 1. introduzione gli studi condotti in questi ultimi anni hanno messo sempre più in evidenza la necessità di leggere un territorio in modo integrato e non settoriale. solo così, infatti, è possibile cogliere appieno le caratteristiche dei vari paesaggi e individuare le modificazioni che hanno subito nel tempo, riconoscendo anche le cause, sia fisiche che antropiche, a cui sono riconducibili. l’esperienza maturata in questo settore ha ampiamente dimostrato che i livelli fondamentali per una simile lettura sono essenzialmente quello geomorfologico e quello storico-topografico, perché proprio dal rapporto tra l’uomo e il territorio partono molte delle trasformazioni che hanno prodotto il paesaggio attuale (dall’aglio, 2000). e’ dunque sul risultato della sovrapposizione tra analisi geomorfologica e ricostruzione dell’antico assetto del territorio che potranno inserirsi gli altri tematismi indispensabili per completare lo studio del paesaggio. al fine dell’applicazione di queste metodologie di indagine si è assunta come riferimento la media valle del fiume cesano, indubbiamente assai eloquente sotto questo punto di vista (dall’aglio, 2004). 214 p.l. dall’aglio et al. 2 lineamenti geomorfologici le fasi genetiche che hanno portato all’attuale conformazione della pianura alluvionale del fiume cesano sono varie e complesse (cfr.calderoni et al.,1991; coltorti, 1991). la piana lungo il tratto vallivo tra san lorenzo in campo e san michele al fiume (fig. 1), ampia mediamente 2 km, presenta bordi esterni netti e rettilinei che si raccordano con versanti caratterizzati da un forte dissesto sia superficiale che profondo. sui versanti sono presenti lembi di terrazzi alluvionali riferibili al “1° e 2° ordine dei terrazzi” della letteratura tradizionale (aa.vv., 1991; nesci et al., 1995 cum bibl.). e’ stato verificato che l’età di inizio della deposizione del corpo alluvionale del “3° ordine”, avvenuta su un substrato reso irregolare dalla presenza di alvei sepolti e interposizione di dossi, eccede la possibilità di misura del metodo del 14c (ca. 44.000 anni bp) e sulla base di varie considerazioni potrebbe collocarsi a 55.000/60.000 anni dal presente (calderoni et al., 1991, nesci et al., 1995). la principale incisione sul substrato, desunta dalle stratigrafie dei numerosi sondaggi eseguiti nell’area studio (nesci & savelli, dati inediti), pur essendo situata a sinistra dell’alveo attuale presenta lo stesso andamento rettilineo dell’odierna tratta dell’attuale cesano. la deposizione del principale corpo alluvionale non avvenne per aggradazione continua, ma secondo meccanismi di cutand-fil l con formazione anche di terrazzi sepolti (calderoni et al., 1991). i depositi, prevalentemente costituiti da ghiaie con subordinati livelli e lenti sabbiose e limoso-argillose, sono riferibili a un fiume con canali intrecciati (fb di nesci & savelli, 1986, 1991). la parte alta dei depositi è quasi ovunque reincisa e rimodellata; vi compaiono facies sabbioso-ghiaiose a stratificazione inclinata depositate da canali meandranti in blando approfondimento (fs di nesci & savelli, 1986, 1991, fase 5 di coltorti, 1991), in discontinuità sui sottostanti depositi pleistocenici (fig. 2). l’approfondimento olocenico di alvei meandriformi, molto complesso, accompagnato e/o interrotto da eventi minori di aggradazione, è ben riconoscibile morfologicamente dalla presenza di ampi paleomeandri anche molto prossimi alla piana pleistocenica. questo particolare comportamento ha caratterizzato gran parte dell’olocene ed è continuato fino in fig.1 schema geomorfologico e distribuzione dei depositi alluvionali lungo il tratto del fiume cesano studiato. geomorphologic sketch and distribution of alluvial deposits for the studied reach of the cesano river valley. età romana. i dati geomorfologici, di cronologia isotopica e i reperti di varia natura a tutt’oggi disponibili non consentono tuttavia un’affidabile distinzione delle varie fasi che caratterizzarono l’evento. la città di suasa si estende (fig. 1) tanto sulla 215geomorfologia e popolamento ... sommità delle alluvioni terrazzate del pleistocene superiore che sull’evidente paleomeandro incassato di qualche metro all’interno di questo (coltorti, 1991). al di sotto di quest’ultimo livello terrazzato si riconoscono altri due ripiani, di cui quello superiore è limitato esterfig. 2 sezioni schematiche nei depositi contenenti i campioni datati. sezione 1 = fronte di cava nei pressi di san michele al fiume, sezioni 2 e 3 = sponda rispettivamente di destra e di sinistra di rio freddo (v. fig.1). l’attribuzione al 500-600 a.d. in sezione 1 si basa sulla età 14c di 1490-1820 b.p. di fig. 1; le analoghe attribuzioni nelle sezioni 2 e 3 derivano da correlazioni di terreno (v. testo per una più approfondita discussione). lithostratigraphic setting of the dated samples. section 1 = quarry nearby st. michele al fiume, sections 2 and 3 = right and left rio freddo banks, respectively (see fig.1). 500-600 a.d. age in section 1 is inferred from 1490-1820 14c ages in fig. 1; the same 500-600 a.d. (?) ages in sections 2 and 3 are derived mainly from field evidence. see the text for a more detailed discussion. fig. 3 la città romana di suasa. a: anfiteatro; b: teatro tuttora sepolto ; c: area della domus dei coiedii; d: area del foro. the roman town of suasa. a: excavated amphiteater; b: theater still buried; c: coiedii domus; c: forum. 216 namente da una serie di scarpate semicircolari ricollegabili a paleomeandri più stretti e con più alto indice di sinuosità di quelli prodotti dall’evento precedente. la stratificazione inclinata e le chiare strutture sedimentarie tipiche di un regime a meandri confermano l’evidenza morfologica (coltorti, 1991). nei depositi che affiorano lungo il rio freddo (fig. 1), verosimilmente riferibili a queste fasi, sono stati rinvenuti numerosi macroframmenti vegetali, alcuni identificati come semi e foglie di quercus sp., che hanno fornito un’età 14c di 2970±70 anni bp (1310-1050 cal. a.c., rome-544). la data permetterebbe di ipotizzare una prima fase, pre-romana, in cui il fiume cesano si presentava alquanto sinuoso, con sponde relativamente stabili, facilmente percorribili e attraversabili e ricoperte da vegetazione simile all’attuale. alcuni affioramenti su un vecchio fronte di cava in sponda destra del f. cesano (fig. 2) contenevano una serie di macroresti di quercus sp., la cui datazione ha fornito le età di 1560±65 anni bp, (420-570 cal a.d., rome-540), 1540±65 anni bp (430-600 cal a.d., rome542), 1490±65 anni bp (440-650 cal a.d., rome-543) e 1820±65 anni bp (90-320 cal a.d., rome-541). osserviamo che tre (rome-540, -542 e –543) delle quattro date sono statisticamente indistinguibili e forniscono un’età media ponderata di 1530±40 anni bp (430-600 cal a.d.), mentre l’età di rome-541 è più antica di ca. 300 anni. quest’ultima data potrebbe suggerire una deposizione in più riprese dei sedimenti campionati anche se non può essere escluso un invecchiamento dovuto al fatto che i reperti datati derivano da vegetazione superiore a lunga vita. sempre da affioramenti lungo il rio freddo sono stati campionati framfig. 4 carta della distribuzione del popolamento antico nella media valle del fiume cesano. map showing the estimated distribution of ancient population over the middle cesano river valley. p.l. dall’aglio et al. 217 menti, visibilmente arrotondati per trasporto, di laterizi romani associati a macroframmenti di quercia anch’essi visibilmente fluitati. le due date 14c ottenute per questi ultimi, 4250±75 e 4550±75 anni bp (rispettivamente rome-545 e –539, che calibrano a 2930-2630 e 33703090 cal a.c.) sono in aperto contrasto con l’età attribuita alla ceramica. tenendo presente che tanto i resti vegetali che quelli archeologici non erano in giacitura primaria, la discrepanza di età rivela che la loro associazione è puramente fortuita e non riflette una origine comune e quindi tanto le date isotopiche che quelle archeologiche forniscono dei termini post-quem per l’aggradazione dei sedimenti contenenti i reperti. l’associazione di materiali che si dispongono su di un arco cronologico di circa due millenni indicherebbe un input poligenico proveniente da uno smantellamento di uno, o più, depositi precedenti ovvero la presenza di un ulteriore, sottile orizzonte alluvionale relativamente “antico” (fig. 2), non distinguibile sul terreno a causa delle cattive condizioni di affioramento. le quattro date potrebbero suggerire comunque che la messa in posto dei depositi dell’unità alluvionale campionata è avvenuta almeno in due riprese, circoscritte tra i secoli i e iv e v e vi a.d. il fatto poi che la quasi totalità dei resti datati si concentrino tra il v e vi secolo può essere un indizio di un intensificarsi degli eventi alluvionali, fenomeno del resto in linea con quanto si conosce sull’evoluzione climatica generale. in questo periodo, infatti, tutti gli autori collocano un peggioramento climatico generalizzato, con un aumento della piovosità e una temperatura mediamente più bassa di circa 2° rispetto all’attuale (pinna, 1996). a quote poco inferiori o talora corrispondenti a quelle dei depositi precedentemente descritti, si rilevano le tracce di un più recente percorso fluviale, delimitato da scarpate nette e prevalentemente rettilinee. la presenza di barre longitudinali, laterali e linguoidi ciottolose testimonia un regime a canali intrecciati (coltorti, 1991). successivamente a questa fase il fiume si è incassato profondamente, assumendo un corso prevalentemente rettilineo molto simile all’attuale. la superficie alluvionale, corrispondente alla fase 2 di coltorti (1991), viene datata anteriormente agli anni ’50; successivamente il fiume subì un ulteriore approfondimento di ca. 10 metri raggiungendo la posizione attuale. 3. il popolamento antico i più antichi insediamenti nella media valle del cesano sono testimoniati da ritrovamenti, in siti ubicati sull’alto ripiano terrazzato di miralbello, dell’età del bronzo medio e recente (xvi-xii secolo a. c.) e della piena attestazione del periodo piceno (viii-v secolo a.c.). tuttavia il maggior numero di ritrovamenti archeologici è di età romana, periodo in cui oltre ad un significativo aumento della densità di popolamento dell’area fu fondata la città di suasa sul terrazzo alla destra del fiume. questo centro, sorto nel iii secolo a.c. come praefectura lungo la strada che dalla conca di sassoferrato scende verso la costa, si trasforma quindi in un vero centro abitato nel corso del i secolo a.c.. la nascita del centro abitato si ricollega alle assegnazioni di terre stabilite con la lex flaminia de agro gallico et piceno viritim dividundo del 232 a.c. (dall’aglio et al., 1991). il conseguente sfruttamento di queste terre ne comportò una decisa antropizzazione, con conseguente disboscamento, regimazione dei corsi d’acqua e tracciamento della centuriazione. la guerra gotica prima e l’invasione longobarda poi, portarono nel corso del vi secolo alla scomparsa della città ed allo spopolamento della pianura di fondovalle. il ruolo di centro ordinatore del territorio, già assolto da suasa, venne di seguito assolto dall’abbazia di san lorenzo in campo. questa fu eretta nell’viii secolo sulla riva opposta del fiume, lungo il diverticolo della via flaminia che da cagli arrivava alla costa, all’apice di un conoide di un affluente del cesano, ossia in posizione più alta rispetto alla piana del fondovalle principale e pertanto al sicuro tanto da esondazioni del fiume quanto da impaludamenti (dall’aglio, 1994). 4. conclusioni i risultati dell’analisi comparata dei dati geomorfologici e storico-topografici dimostrano, anche nel caso di questo studio, che i criteri di scelta per l’ubicazione di un insediamento sono legati, soprattutto in età romana, ai risultati di un’attenta lettura dell’assetto fisico del territorio nonché, per quanto poteva essere percepito, della sua evoluzione. non è quindi casuale che i resti delle fattorie romane si rinvengano su quelle unità morfologiche (essenzialmente i terrazzi di fondovalle a ridosso del versante e i pianori situati lungo crinale e versante) che offrono le condizioni più vantaggiose per la pratica dell’agricoltura. viceversa in età preromana, quando la situazione politica era caratterizzata da una maggiore instabilità e insicurezza, gli insediamenti tendono a collocarsi prevalentemente in zone sopraelevate e che quindi potevano essere facilmente difese e consentivano un controllo visivo sul territorio circostante (dall’aglio, 1994). a questo intrecciarsi di motivazioni geografiche e storiche non si sottrae neppure l’ubicazione della città romana di suasa. essa infatti è collocata su di un terrazzo alluvionale di fondovalle alla destra del cesano, denominato pian volpello, che è il primo terrazzo di una certa ampiezza che si incontra provenendo dalla conca di sassoferrato seguendo il solco vallivo di un affluente di destra del cesano, il t. nevola. in altri termini, la città nasce lungo la strada che univa sentinum alla costa correndo parallela all’altro asse stradale che da sentinum raggiungeva sena gallica, la più antica colonia dedotta dai romani nelle marche, seguendo la valle del misa (dall’aglio, 1991). questo legame tra suasa e la viabilità gravitante su sentinum dimostra come il nostro centro sia nato prima della apertura del sistema stradale incentrato sulla via flaminia, aperta, come noto, nel 220 a.c.: il diverticolo che unisce la via flaminia a senigallia passando per cagli e citato nelle fonti itinerarie (it. ant., 315,7-316,5) corre infatti sull’opposta riva del cesano. se dunque suasa fosse nata quando il sistema della flaminia era ormai consolidato, sarebbe sorta sulla sinistra del fiume, nella zona, ad esempio, di san lorenzo in campo e non sulla destra. la scelta del terrazzo di pian volpello, poi, è dovuta da un lato, come si è detto, alla sua ampiezza che consente l’impianto delle strutture proprie di una città, come il foro, il teatro, l’anfiteatro, oltre alle case di abitazione che, come noto, in età romana si sviluppavano più in geomorfologia e popolamento ... 218 ampiezza che in altezza, e all’essere comunque alto rispetto al fiume e quindi al riparo delle normali ondate di piena. la romanizzazione non si concretizzò solo nella nascita di un nuovo centro urbano, ma, ancor prima che suasa divenisse una città, con l’assegnazione delle terre conquistate ai coloni, assegnazione che avvenne nel 232 a.c. in seguito alla lex flaminia de agro gallico et piceno viritim dividundo (paci, 1998). tale operazione comportò il tracciamento della centuriazione al fine di individuare i vari lotti da assegnare ai coloni e, di conseguenza, alla nascita di un paesaggio dominato dal coltivo e da un regolare disegno dei campi. se si analizza l’attuale organizzazione della campagna in questo tratto di valle è facile notare come quella regolarità imposta dagli antichi agrimensori sia pressoché cancellata (bonora & dall’aglio, 1991). dal momento che, di norma, nelle nostre campagne si hanno notevoli persistenze della centuriazione è necessario interrogarsi sulle cause che hanno portato qui alla nascita di un assetto territoriale completamente avulso da quello di età romana. per giustificare una simile cancellazione si invoca spesso il peggioramento climatico di età tardoantica (e.g. veggiani, 1973). in altri termini si dice che l’aumento della piovosità ha causato alluvioni disastrose, come quelle citate da paolo diacono per il 589 e che per questo vanno sotto il nome di “diluvium di paolo diacono” (paul. diac., hist. lang., iii, 23-24), che avrebbero cancellato qualsiasi traccia dell’organizzazione territoriale precedente. in realtà l’aumento della piovosità, per quanto accompagnato da una generale diminuzione della temperatura e da un aumento delle burrasche che, nel caso dei fiumi marchigiani, avrebbero ulteriormente favorito, specie nelle piane costiere, alluvioni e rigurgiti ostacolando il già spesso difficile deflusso delle acque in mare (marabini 1996), non è in grado da solo di determinare variazioni nell’andamento dei corsi d’acqua e stravolgimenti nella geografia e nell’organizzazione del territorio. perché un’organizzazione territoriale perfettamente coerente con la geografia fisica di un territorio com’era la centuriazione venga del tutto o in parte cancellata è necessario che accanto a fenomeni naturali, quale, appunto, il peggioramento climatico, ci siano anche fattori antropici (dall’aglio, 1998). se infatti fosse sufficiente solo il fatto climatico, dovremmo trovare analoghi esiti anche in occasione della c.d. piccola età glaciale, cosa che invece non accade proprio grazie alla forte presenza antropica sul territorio. viceversa a partire dal iv secolo si ha un progressivo calo demografico, che raggiunge il suo culmine alla metà del vi secolo, all’epoca della guerra grecogotica, e che ha come conseguenza il restringimento di quasi tutti i centri urbani e addirittura la scomparsa di molti di questi, come ad esempio avviene per suasa, o la loro riduzione a semplici villaggi (dall’aglio, 2002). questo spopolamento non interessa, ovviamente, solo le città, ma anche le campagne dove si ha prima di tutto il venir meno della normale manutenzione dei canali di drenaggio e di tutte quelle opere che consentivano di controllare i vari corsi d’acqua. sono così possibili variazioni nell’andamento dei corsi d’acqua e l’innesco di fenomeni di impaludamento e di dissesto idraulico, con una ripresa anche dell’incolto, in primo luogo del bosco. il paesaggio coltivato e regolare di età romana, con un fitto popolamento delle campagne, si trasforma progressivamente in un paesaggio più vicino a quello preromano, caratterizzato da boschi, paludi, da corsi d’acqua non più regimati e da un popolamento decisamente più scarso e che nelle vallate marchigiane prediligeva sopratutto le alture lungo i crinali perché naturalmente difese a scapito dei fondovalle, più esposti e quindi non più insediati. anche la cancellazione della centuriazione nella media valle del cesano va dunque inquadrata in questo mutato equilibrio tra uomo e ambiente e quindi come il risultato di un’azione combinata di eventi naturali e antropici, azione alla quale vanno attribuiti anche i cambiamenti di regime e di caratteristiche del cesano (cfr. coltorti 1997). del resto la presenza qui di ampie zone boscate è indirettamente confermata dal nome, san lorenzo in sylvis, del monastero che nel primo medioevo viene costruito sulla sinistra del cesano, lungo l’antico diverticolo della via flaminia (dall’aglio, 1991). sarà questo monastero, per altro collocato all’apice di un conoide di un affluente del cesano in modo da trovarsi in una posizione alta rispetto la pianura circostante, a ereditare, in un certo senso, il ruolo dell’antica e ormai scomparsa suasa, e a favorire la rioccupazione e la rimessa a coltura della media valle. nel pieno medioevo quest’operazione può dirsi conclusa, tanto che il centro sorto attorno al monastero cambia nome per assumere la denominazione attuale di san lorenzo in campo, attributo che chiaramente testimonia l’avvenuta trasformazione del paesaggio (dall’aglio, 1994). tale nuova sistemazione avviene però su di un quadro fisiografico diverso da quello di età romana e questo comporta l’impianto di un disegno differente da quello a suo tempo tracciato dagli agrimensori romani. bibliografia autori vari (1991) l’ambiente fisico delle marche. geologia, geomorfologia, idrogeologia. carta geologica alla scala 1:100.000. s.e.l.c.a. firenze. bonora g. & dall’aglio p. l. (1991) la centuriazione della valli del misa e del cesano. in: dall’aglio p. l., de maria s. & mariotti a. (eds.) “archeologia nelle vallate marchigiane: le valli del misa e del nevola”. electa editori umbri perugia, pp. 28-34. calderoni g., nesci o. & savelli d. (1991) terrace fluvial deposits from the middle basin of cesano river (nothern marche apennines): reconnaissance study and radiometric constraints on their age. geogr. fis. din. quat., 14, 2, pp.201-207. coltorti m. (1991) modificazioni morfologiche oloceniche nelle piane alluvionali marchigiane: alcuni esempi nei fiumi misa, cesano e musone. geogr. fis. din. quat., 14, 1, pp. 73-86. coltorti m. (1997) human impact in the holocene fluvial and coastal evolution of the marche region, central italy. catena, 30 , pp. 311-335. dall’aglio p. l., de maria s. & mariotti a. (1991) archeologia delle valli marchigiane misa, nevola e cesano. electa editori umbri, perugia. dall’aglio p. l. (1991) la viabil ità romana. in archeologia nelle vallate marchigiane: le valli del misa e del nevola, electa editori umbri, perugia, pp. 12-23. dall’aglio p. l. (1994) il popolamento romano dell'ager suasanus: prime considerazioni ed ipotesi. in: "le p.l. dall’aglio et al. marche: archeologia. storia. territorio", v (199193), pp. 151-157. dall’aglio p. l. (1998) il diluvium di paolo diacono e le modificazioni ambientali tardoantiche: un problema di metodo. ocnus, 5 (1997), pp. 97-104. dall’aglio p. l. (2000) geomorfologia e topografia antica. la topografia antica, bologna, pp.177-192. dall’aglio p. l. (2002) l’età romana, in: sulle tracce del passato, stibu, urbania, pp. 17-26. dall’aglio p. l. (2004.) per una “carta del rischio archeologico” della valle del cesano. “atti del convegno sulla carta archeologica regionale”. fiastra, giugno 2002, in stampa. marabini f. (1996) evoluzione dell’ambiente costiero in tempi storici e le variazioni cl imatiche, i l quaternario. 9, pp. 201-204. nesci o. & savelli d. (1986) cicli continentali tardoquaternari lungo i tratti vallivi mediani delle marche settentrionali. geogr. fis. dinam. quat., 9, pp. 192-211. nesci o. & savelli d. (1991) successioni alluvionali terrazzate nell’appennino nord-marchigiano. geogr. fis. din. quat., 14, 1, pp. 149-172. nesci o., savelli d., calderoni g., elmi c. & veneri f. (1995) le antiche piane di fondovalle nell'appennino nord-marchigiano. in: castiglioni g.b. & federici p.r. (eds.) "assetto fisico e problemi ambientali delle pianure italiane". mem. soc. geogr. it., 53, pp. 293-312. paci g. (1998) umbria ed agro gallico a nord del fiume esino, picus, 18, pp.89-118 pinna m. (1996) le variazioni del clima, franco angeli, milano. veggiani a. (1973) prime considerazioni su due periodi di dissesti idrogeologici nella pianura padana in epoca storica, atti 3 conv. naz. studi problemi geologia applicata, firenze, pp. 157-164. 219 ms. ricevuto il 4 maggio 2004 testo definitivo ricevuto il 20 ottobre 2004 ms. received: may 4, 2004 final text received: october 20, 2004. geomorfologia e popolamento ... amq29(2) 2 marino 123-135 nag.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 29 (2), 2016, 123 -135 the montalbano jonico section (south italy) as a reference for the early/middle pleistocene boundary maria marino 1, giuseppe aiello 2, diana barra 2, adele bertini 3, salvatore gallicchio 1, angela girone 1, rafael la perna 1, fabrizio lirer 4, patrizia maiorano 1, paola petrosino 2, ornella quivelli 5, francesco toti 3, neri ciaranfi 1 1 dipartimento di scienze della terra e geoambientali, bari university, italy 2 dipartimento di scienze della terra dell’ambiente e delle risorse, naples university, italy 3 dipartimento di scienze della terra, florence university, italy 4 iamc (istituto per l’ambiente marino costiero)-cnr, naples, italy 5 o.quivelli@gmail.com corresponding author: m. marino <maria.marino@uniba.it> abstract: the most recent data obtained at the montalbano jonico succession (mjs), in the interval including the marine isotope stage (mis) 19, document the occurrence of numerous chronostratigraphic constraints and paleoenvironmental events contributing to the knowledge of a crucial time through the lower-middle pleistocene transition, characterised by major modifications of the earth’s climate system. marine and terrestrial biologic data-sets (pollen, ostracods, benthic and planktonic foraminifera, coccolithophores, teleostean fishes, mollusks) are compared with the high resolution astronomically-tuned benthic oxygen isotope curve in order to provide accurate paleonvironmental reconstruction and acquire additional climatostratigraphic and biostratigraphic constraints within a chronostratigraphic framework which also includes the 40ar/39ar ages of three volcaniclastic layers. environmental and climatic events (e.g. termination ix, substages 19.3, 19.2, and 19.1, maximum flooding and climate optimum, maximum depth) highlight a succession of clear paleoenvironmental changes close to mis 19, showing a remarkable correspondence between the response of marine and terrestrial proxies. such changes have stratigraphic implication and high potential of correlation as they evidence wide scale climate changes, stressing the tight interconnection between the mediterranean region and north atlantic ocean. based on these results the mjs reveals to be an excellent candidate for the lower-middle pleistocene subseries boundary. in fact, at present the mjs fully meets the requirements indicated by remane et al. (1996) for a gssp selection with the sole exception that a paleomagnetic signal is missing. 10be analyses are in progress and should enhance the already rich documentation of several independent age-significant elements, contributing to the recent critical discussion on the significance of the magnetic signal at the matuyama-brunhes boundary as well as its role as a primary marker for the middle pleistocene gssp definition. keywords: montalbano jonico section (south italy), early-middle pleistocene boundary, chronological and climatostratigraphical constraints 1. introduction the montalbano jonico section (mjs) is a candidate for the global boundary stratotype section and point (gssp) of the middle pleistocene subseries (ciaranfi et al., 1997) due to the detailed biostratigraphic, climatostratigraphic and chronological constraints arising from multidisciplinary studies conducted over the past twenty years (ciaranfi et al., 1994; 1996; 1997; 2001; 2010; marino, 1996; girone & varola, 2001; d’alessandro et al., 2003; stefanelli, 2003; 2004; maiorano et al., 2004; 2008; 2010; stefanelli et al., 2005; girone et al., 2013a; sagnotti et al., 2014; aiello et al., 2015; bertini et al., 2015; marino et al., 2015; petrosino et al., 2015) and meets most of the requirements mentioned in remane et al. (1996) for the selection of a gssp. the primary criterion for defining the lower-middle pleistocene boundary was indicated as a point to be selected in a marine succession close to the matuyama-brunhes boundary (mbb) (richmond, 1996; pillans, 2003; head & gibbard, 2005; cita et al., 2006; head et al., 2008; head & gibbard, 2015a). the mbb is a geomagnetic polarity reversal characterised by different age assignments (see syntheses in channell et al., 2010; head & gibbard, 2015b), polarity transition lasting up to 8 kyr (channell & kleiven, 2000; channell et al., 2004; leonhardt & fabian, 2007), associated short-lived precursor (s) (hyodo et al., 2006, 2011; wang et al., 2006; yang et al., 2010; channell et al., 2010; sagnotti et al., 2014), and by a slightly diachronous character also depending on latitudinal and longitudinal places (clement, 2004; leonhardt & fabian, 2007). change in sedimentation rate (and related age-depth model), and the influence of burrowing may produce differences in magnetic recording efficiency and timing (magnetic lock-in depth) of remanence acquisition, possibly introducing uncertainties in the natural magnetization process in marine and continental sediments and age-assignment of the mbb (demenocal et al., 1990; channell et al., 2010; suganuma et al., 2010; roberts et al., 2013; snowball et al., 2013; head & gibbard, 2015b). when correlated to marine oxygen isotope stratigraphy (mis 19, shackleton et al., 1990), in sedimentary successions the mbb may fall at the base, in the middle, or in the upper part of stage 19. on the other hand, climatostratigraphy during mis 19 is revealed to be a critical means to improve work presented during the aiqua scientific conferences "waiting for the nagoya inqua xix congress", held in florence, june 18 19, 2015 124 marino m. et al. knowledge on climate evolution during this stage and to enhance correlation between marine and terrestrial realms at the global scale. moreover, according to some authors, paleointensity minima during mbb seem to have affected change in cosmogenic ray flux and earth’s climate (kitaba et al., 2012; hyodo & kitaba, 2015). this aspect strengthens the widely accepted importance of climate in quaternary stratigraphy, the stage boundaries being characterised by biological/ physical/geochemical documentation of profound changes in the global climate. multiple chrono/ climatostratigraphic constraints are then necessary in the interval including mis 19 and the matuyamabrunhes transition in order to have helpful and constructive tools aiding local/regional/global (possibly land– marine) correlation, which is a crucial feature for the selection of gssp (remane et al., 1996; gradstein et al., 2003). the aim of this paper is to provide a synthesis of recent data sets collected throughout mis 19 at montalfig. 1 location and stratigraphy of the montalbano jonico section. main lithological features of the composite section obtained by correlating several partial sections (fg-m). chrono-biostratigraphic constraints are shown together with benthic δ18o (brilli et al., 2000; ciaranfi et al., 2010; maiorano et al., 2010). marine isotope stages are according to ciaranfi et al. (2010). ages of volcaniclastic layers are according to ciaranfi et al. (2010), maiorano et al. (2010), petrosino et al. (2015). 125 the montalbano jonico section (south italy) ............ bano jonico and supply preliminary new results which improve the reliability of the numerous chronostratigraphic and climatostratigraphic markers recognized in the section close to the early-middle pleistocene boundary. a synthesis of these results was presented at the “scientific days” (florence, june 18-19, 2015) organized by aiqua (italian association for quaternary study). 2. the montalbano jonico section the lower-middle pleistocene composite section of montalbano jonico crops out in the lucania basin (balduzzi et al., 1982), a minor basin of the foredeep (bradano trough, in casnedi, 1988) between the apennines chain and the apulia foreland (fig. 1). the mjs is about 450 m thick and consists of a coarsening upward succession formed by hemipelagic silty clays and, in its upper part, by sandy clays (ciaranfi et al., 2010) (fig. 1). the whole section represents the regressive part of a third-order cycle with several fourth and fifthorder cycles mainly induced by climate changes (ciaranfi et al., 1997; 2001). stable oxygen isotope analyses performed throughout the entire succession on planktonic (globigerina bulloides) and benthic (cassidulina carinata) foraminifer tests (brilli et al., 2000; ciaranfi et al., 2010), combined with high resolution quantitative calcareous plankton biostratigraphy (marino, 1996; maiorano et al., 2004; ciaranfi et al., 2010; maiorano et al., 2010; girone et al., 2013a), 40ar/39ar data on volcaniclastic layers v3, v4 and v5 (ciaranfi et al., 2010; maiorano et al., 2010; petrosino et al., 2015), pollen data (joannin et al., 2008), and sapropel stratigraphy (d'alessandro et al., 2003; stefanelli, 2004; stefanelli et al., 2005; maiorano et al., 2008), have provided the astronomical calibration of the mjs that covers the time interval mis 37–16, i.e., 1.24–0.645 ma (ciaranfi et al., 2010; maiorano et al., 2010). the calcareous plankton biochronology at montalbano (maiorano et al., 2010; girone et al., 2013a) compares well with that in the mediterranean sea and atlantic and pacific oceans, suggesting that the section is valuable for long distance biostratigraphic correlation. the mjs represents a unique on-land continuous succession spanning this long time interval and, together with the astronomically-tuned vrica section, covers the entire calabrian stage (maiorano et al., 2010). furthermore, it encompasses the timing of the matuyama-brunhes transition. the ideale section, is one of several comprising the montalbano jonico composite section, and is the key stratigraphic succession deposited continuously during mis 20-18 (fig. 1). 3. stratigraphic and paleonvironmental constraints through mis 21-mis 18 recent multidisciplinary studies improved knowledge across the interval from mis 21 to mis 18 time (aiello et al., 2015; bertini et al., 2015; marino et al., 2015; petrosino et al., 2015), based on orbital to millennial scale marine and terrestrial biological data set (pollen, ostracod, benthic microand macroinvertebrates), mainly obtained by the analysis of the same samples studied for oxygen isotope stratigraphy (fig. 2). some of the taxa recorded from the rich and diverse microand macrofossil assemblages at mjs are illustrated in plates 1 and 2. chemical studies on juvenile vitric fragments and mineral phases from the volcaniclastic layers allowed these marker levels to be more exhaustively described in terms of their potential source and correlation to other tephra layers in both southcentral italy lacustrine successions and in marine onland and deep-sea cores within a lower-middle pleistocene mediterranean tephrostratigraphic framework. the fine chronostratigraphic and paleoenvironmental outline obtained at the mjs makes the section an excellent candidate for the lower-middle pleistocene gssp in spite of an absent paleomagnetic signal (including the mbb) throughout the section because of remagnetization (sagnotti et al., 2014). the several events recorded in the ideale section have high potential for wide-scale correlation and therefore may provide multiple constraints suitable for the selection of the gssp. focusing on the mis19, it is clearly depicted between mis 20 and mis18 at the mjs by the planktonic and benthic δ18o records (ciaranfi et al., 2010; maiorano et al., 2010). the interval straddling mis 19 is very well chronologically constrained, bracketed by the 40ar/39ar ages of two volcaniclastic layers: v3 (801.2±19.5 ka) in mis 20, and v4 (773.9±1.3 ka) in mis 19. the age of v4 is very close to the age of the mbb, referred to 773 ka according to channell et al. (2010). the beginning and end of the second temporary disappearance of the coccolithophore gephyrocapsa omega, at 829 ka and 752.76 ka respectively (fig. 2e), provide valuable bioevents for long distance correlation as they always enclose mis 19 in mediterranean sea and atlantic ocean records (maiorano & marino, 2004; maiorano et al., 2004). additional higher resolution oxygen isotope studies across mis 19 are in progress at the mjs and support the excellent climate signal in the section (nomade et al., 2015). the main climatostratigraphical constraints are shown in figures 2 and 3 and discussed below. 3.1 the cold climate phase in the uppermost mis 20 and termination ix the inception of mis 19 is preceded by a highamplitude shift to lighter δ18o values at the mis 20/19 deglaciation of about 2‰, between ca. 794 ka and 782 ka, marked by a change in sediment color from light gray (mis 20) to dark gray (mis 19) (figs. 1, 3). pollen data provide evidence of a strong increase of herbs (exceeding 90%) with steppe and halophyte taxa as the main components, centered at about 790 ka (bertini et al., 2015; marino et al., 2015). this event correlates with prominent peaks in the records of north atlantic ice rafted debris (ird, at the ocean drilling program site 980, wright & flower, 2002) and mediterranean aeolian dust (larrasoaña et al., 2003) (fig. 2b-d), suggesting a phase of arid and cold climate (see lowest values in the percentage of arboreal plant-ap curve and in the pollen temperature index-pti at mjs) which marks the collapse of north hemisphere ice-sheet and the end of fig. 2 comparison between the montalbano jonico succession and other reference lower-middle pleistocene records (modified from marino et al., 2015, and this work). a) synthetic reconstruction of greenland temperature variability (glt_syn, barker et al., 2011); b) east mediterranean dust record based on hematite content derived from magnetic properties of sediments from odp site 967 (larrasoaña et al., 2003); c) ice rafted detritus (ird) curve from north atlantic odp site 980 (wright & flower, 2002) versus age according to lisiecki & raymo (2005); d) benthic δ18o curve from site 980 (wright & flower, 2002); e) benthic δ18o at the montalbano jonico section (mjs); f) pollen temperature index in logarithmic scale (pti, i.e. the ratio between mesothermic arboreal taxa and steppe taxa to discriminate warmtemperate from cold phases, according to joannin et al. (2008) and suc et al. (2010); g) arboreal pollen, ap%; h) pollen distality index (pinus vs. halophytes), in logarithmic scale; i) ostracod paleodepth curve; j) benthic foraminifera paleodepth curve (stefanelli, 2003); k) global sea level curve (bintanja & van de wal, 2008). age model of the mjs records is from maiorano et al. (2010) slightly updated in marino et al. (2015). substage nomenclature is according to bassinot et al. (1994). bars on the pti curve represent climate phases: warm and humid phase a, c, g, i (orange); cool phase d, f, h, j (grey); cold and arid phases b, e, ja and jb (blue); minor short-term climate events are indicated as 1 and 2 (cool phases) on the ap% curve. v3 and v4: volcaniclastic layers tm: thermal maximum (girone & varola, 2001); mf (maximum flooding) and md (maximum depth) from d'alessandro et al. (2003); td2: second temporary disappearance of g. omega (sensu maiorano & marino, 2004); tix: termination ix. 126 marino m. et al. glacial mis 20. calcareous plankton data (maiorano et al., 2016) support the prominent cold climate phase recording the higher abundance of arctic-subarctic coccolitus pelagicus ssp. pelagicus and neogloboquadrina pachyderma left-coiling, and the lowest values of the planktonic foraminifera derived sea surface temperature-sst curve (m. kucera, work in progress) in the uppermost glacial mis 20. similar patterns in key calcareous plankton taxa are documented in the mediterranean sea at the glacial-interglacial transition during the mid-brunhes interval (girone et al., 2013b; maiorano et al., 2013; capotondi et al., 2016), demonstrating that the mediterranean signal of short-lived global climate change may be extended down to mis 20/mis 19 deglaciation. such result, in agreement with the δ18o pattern at the transition mis 20/mis 19 (fig. 2e), could represent the younger dryas-like cold and dry event (giaccio et al., 2015); however the ongoing higher resolution oxygen isotope study (nomade et al., 2015) and calcareous plankton and pollen analyses (maiorano et al., 2016) may give more conclusive detail on climate evolution at this time. a minimum in the benthic foraminifera paleodepth pattern (stefanelli, 2003, 2004) is also recorded very close to the cold and arid event highlighting a prominent sea level fall (fig. 2j). the event, combined with the high-amplitude change in benthic foraminifera and ostracod-derived paleodepth curves recorded just above, enables the identification of termination ix (figs. 2, 3) which is considered the most prominent marker in the δ18o record before the mbb in mis 19 (channell et al., 2010). these results together provide the first documentation in mediterranean onland marine sediments of termination ix, a characteristic climate signal in global ocean records (i.e. lisiecki & raymo, 2005). the prominent sea level change associated with termination ix is correlatable with the boundary between the third order cycles tb3.8-tb3.9 (haq et al., 1987) at the major sequence boundary “io1” (ca 0.8 ma, hardenbol et al., 1998; ca. 0.78 ma, snedden & liu, 2010) and is recorded in the curve of global sea level of bintanja & van de wal (2008) (fig. 2k). termination ix may be also recognizable in terrestrial sediments (i.e. florindo et al., 2007) supporting its value in climatostratigraphy. 127 the montalbano jonico section (south italy) ............ 3.2. mis 19.3, maximum flooding, climate optimum, and maximum depth the δ18o pattern and all biological proxies clearly record the onset of mis 19 (fig. 2) which is also visible in the color sediment change at termination ix in the ideale section (figs 1, 3). the deposition of darker sediments characterizes the mis 19 interval as may be expected during an interglacial phase and high sea level, when water column stratification could have reduced oxygen levels and thereby increased organic matter preservation on the sea floor. moreover, the δ18o pattern distinctively describes substages 19.3, 19.2, and 19.1 (figs. 1, 3). all biological data from both marine (i.e. marino et al., 2015) and terrestrial (bertini et al., 2015; toti, 2015) realms support the substage subdivision indicating 19.3 as the warmest, based on the elevated values in pti and ap curves. increases in the warmwater calcareous plankton taxa confirm the peculiar climate behavior of substage 19.3. in detail, calcareous plankton records the highest abundance of warm water plate 1 a-c. benthic foraminifer discopirina italica (costa, 1856) with pyrite infilling, scale bar = 2 mm (a, b), 1 mm (c). d-l. neopycnodonte cochlear (poli, 1795), scale bar = 10 mm.valves and valve fragments from the maximum flooding level in mis 19. note the bioeroded and bioencrusted surface of the large fragment e, suggesting exposure on the sea bottom due to low sedimentation rate. m, n. ostracod species commonly recorded in the montalbano jonico section, typical of the circalittoral zone in the mediterranean. m. semicytherura ruggieri pucci, 1955, left valve, scale bar = 100 µm. n. sagmatocythere concentrica (bonaduce, ciampo & masoli, 1976), left valve, scale bar = 100 µm. 128 marino m. et al. taxa in the lower portion of substage 19.3 (maiorano et al., 2016) in correspondence with the lowest δ18o value (ca. 782 ka), suggesting a climate optimum in the sea surface waters. during the 780.56-777.31 kyr interval, the presence of tropical-subtropical mesopelagic teleostean fish bonapartia pedaliota (girone & varola, 2001) (plate 1, o) suggests warmer conditions deeper in the water column; the highest percentages of quercus (here included among the ap, see bertini et al., 2015 for detail) and pti, are recorded contemporaneously (fig. 2f). concomitantly, the maximum flooding is indicated by the occurrence of a neopycnodonte cochlear community (d’alessandro et al., 2003) (figs. 2e, 3, plate 1, d-l). it is a deep-water oyster forming encrusting clusters, most probably thriving under conditions of low sedimentation rate, as suggested by the ecological data on a congener species (wisshak et al., 2009; gofas et al., 2010). such environmental conditions are possibly related to the rapid sea level rise after deglaciation. the maximum depth follows the maximum flooding (ca. 777.3 ka-ca. 773.2 ka), and it is highlighted by the benthic invertebrate communities (d’alessandro et al., 2003) which record dispersed macrobenthic fauna and the occurrence of bathyal taxa such as discospirina italica (plate 1, a-c), a large miliolid foraminifer from deep waters (gooday et al., 2013), the mollusks dentalium agile, cadulus ovulum, neilonella pusio and delectopecten vitreus, typical of pleistocene bathyal assemblages (di geronimo and la perna, 1997); this phase probably reflects higher sedimentation rate and deeper waters which prevented the development of the neopycnodonte (n. cochlear) community. the occurrence of the bathyal ostracod krithe compressa is consistent with deeper environment. therefore, this paleocommunity indicates a transition to a slope setting (“discospirina, nassarius” communities in d’alessandro fig. 3 main chronological and paleoenvironmental constraints drawn on the outcrop of the ideale section. <<< -------------------------------------- --------------------------------- plate 2 micrographs of representative pollen grains (a-u), organic-walled dinocysts (v-ab) and other palynomorphs (ab, ac) from the mis 20-18 interval of the mjs. a. centaurea (equatorial view). b. artemisia (equatorial view). c. amaranthaceae. d. asteraceae, cichorioideae. e. hippophaë (equatorial view). f. deciduous quercus (equatorial view). g. plantago lanceolata type. h. ephedra distachia type (equatorial view). i. poaceae (distal view). j. cyperaceae (equatorial view). k. alnus (polar view). l. tilia (polar view). m. corylus (polar view). n. fabaceae (equatorial view). o. pterocarya (polar view). p. ericaceae (tetrad in polar view). q. carpinus betulus (polar view). r. calligonum (equatorial view). s. cedrus (proximal view). t. pinus (equatorial view). u. tsuga diversifolia type (proximal view). v. impagidinium patulum (lateral view). w. polysphaeridium zoharyi (apical view). x. spiniferites hyperacanthus type (ventral view). y. lingulodinium machaerophorum (lateral view). z. spiniferites ramosus (lateral view). aa. impagidinium aculeatum (cross section). ab. tectatodinium pellitum (cross section). ac. ophioglossum type (proximal view). ad. classopollis (polar view, reworked). all scale bars are 20 µm. 129 the montalbano jonico section (south italy) ............ et al., 2003) during a sea-level high stand, in good agreement with the major deepening during mis 19 suggested by benthic foraminifera (stefanelli, 2003) and ostracod assemblages (aiello et al., 2015) from ca. 779 ka to 773 ka (marino et al., 2015), close to the increase in the values of pollen distality index (bertini et al., 2015) (fig. 2h). 3.3. end of full interglacial, mis 19.2-19.1 towards mis 18 the end of substage 19.3 is marked by the increase of steppe and halophyte elements associated with the slightly higher values in the δ18o record, during substage 19.2, at about 771.8 ka, just above the v4 layer (fig. 2e-g). the signal of a decrease in seasurface temperature is also recorded in the calcareous plankton assemblage (maiorano et al., 2016), since a distinct drop occurs in the abundance of the warm water taxa. a contemporaneous decrease in the pattern of a synthetic (modeled) reconstruction of greenland temperature (barker et al., 2011) is evident (fig. 2a). upwards, in mis 19.1, again warm and humid conditions are inferred by pollen data (increase in arboreal mesothermic taxa, fig. 2g) (bertini et al., 2015), according to lighter values in δ18o (fig. 2e). an upward decreasing trend in mesothermic arboreal taxa parallels the increase of open vegetation taxa concomitant with heavier δ18o values, thus marking the beginning of the climate deterioration associated with mis 18. distinct fluctuations in isotope curve and biological proxies, and in sediment color as well (figs. 1-3), are also recorded in mjs during this glacial inception. they are in good agreement with the ird and oxygen patterns at the north atlantic site 980 (fig. 2c-d), and with the synthetic reconstruction of greenland temperature variability (fig. 2a), evidencing global features of suborbital climate variation widely documented in oceanic and lacustrine (i.e. wright & flower, 2002; kleiven et al., 2011; giaccio et al., 2015), and ice core (i.e. jouzel et al., 2007; pol et al., 2010; barker et al., 2011) records. a better understanding of climate evolution at the end of the full interglacial mis 19, considered the best analogous of the holocene (tzedakis et al., 2012; yin & berger, 2012), is crucial for evaluating the temporal extent of the current interglacial and for future climate prediction. 4. conclusions the mjs sedimentary succession provides an exceptional data-set to trace the main palaeoenvironmental and climatic changes through mis 37-mis 16 in the central mediterranean, a historical key area for the study of quaternary stratigraphy and climate. the timing and mode of such changes are examined closely in the interval mis 20-mis 18, and correlated with climate fluctuation from globally-distributed records. the integrations of continental (pollen) and marine (ostracods, benthic and planktonic foraminifera, coccolithophores, teleostean fishes, mollusks) proxies allows us to document, up to millennial scale, the nearly contemporaneous response to paleoenvironmental events in the two biological domains, providing an invaluable tool for marine-terrestrial correlation. multiple chronoand climato stratigraphic constraints are recorded and the most important are synthesised in fig. 3: a) coldest phase in the uppermost mis 20; b) termination ix; c) substages 19.3, 19.2, 19.1; d) events of maximum flooding, climate optimum, and maximum depth; e) end of the second temporary disappearance of gephyrocapsa omega; f) radiometric age of volcaniclastic layers v3 and v4 bracketing mis 19. the plethora of data for the mis 20 to mis 18 interval collected in the continuous succession (ideale section) makes it possible to consider the mjs highly suitable for hosting the gssp of the middle pleistocene subseries and its associated stage. in fact, it meets most of the requirements cited in remane et al. (1996) for a gssp: i) geological, i.e. exposure over an adequate thickness, continuous sedimentation, high sedimentation rate, absence of synsedimentary and tectonic disturbances, absence of metamorphism and strong diagenetic alteration (see ciaranfi et al., 2010; maiorano et al., 2010); ii) biostratigraphic, i.e. abundance and diversity of well preserved fossils, absence of vertical facies changes, favourable facies and numerous biovents for long-range biostratigraphic correlations (see marino, 1996; girone & varola, 2001; d’alessandro et al., 2003; stefanelli, 2003, 2004; maiorano & marino, 2004; maiorano et al., 2004; joannin et al., 2008; maiorano et al., 2008; girone et al., 2013a; aiello et al., 2015; bertini et al., 2015; marino et al., 2015); iii) chemostratigraphic and astrochronology (see brilli et al., 2000; ciaranfi et al., 2010; maiorano et al., 2010); iv) radioisotopic dating (see ciaranfi et al., 2010; maiorano et al., 2010; petrosino et al., 2015); v) sapropel stratigraphy (see d’alessandro et al., 2003; stefanelli, 2003; stefanelli et al., 2005; maiorano et al., 2008). finally, accessibility, free access, permanent protection of the mjs site are guaranteed by a regional law (l.r. january 27-2011, n.3) by the basilicata regional administration that established the special nature reserve of the montalbano jonico badlands. panoramic views of the badlands and some details of the ideale section are visible at the link: https://youtu.be/pd8aeiszi4m. the section has been visited by people from many countries during several scientific fieldtrips, the most recent held in bari (italy, field-workshop on the lower-middle pleistocene transition in italy, october 11 -13, 2014) (fig. 4) organised by the dipartimento di scienze della terra e geoambientali (university of bari), and supported by the italian association for quaternary study (aiqua) and international commission on stratigraphy (ics) (ciaranfi et al., 2015). 130 marino m. et al. the mjs is the focus of new investigations even now; supplementary higher temporal resolution analyses on calcareous plankton and pollen, and on mineralogic features of sediments across mis 19 have been recently performed (maiorano et al., 2016). planktonic and benthic oxygen isotope stratigraphy up to the centennial scale is advancing close to mis 19 in the ideale section (nomade et al., 2015) and will provide the best δ 18o record from an onland marine succession known so far. analyses on the cosmogenic radionuclide 10be are in progress; the latter has a distinctive pattern (10be flux anomaly) during the mb transition as documented in the sediments (e.g., frank et al., 1997; christl et al., 2003; suganuma et al., 2010) and ice cores (e.g., wagner et al., 2000; raisbeck et al., 2006; dreyfus et al., 2008). results of these analyses are promising and will likely be compared with other worldwide records, with the aim to provide reliable information on the timing of the paleomagnetic reversal, avoiding the possible effect of postdepositional remanent magnetization lock-in of the geomagnetic signal (suganuma et al., 2011; roberts et al., 2013). acknowledgements valuable comments and suggestions by an anonymous reviewer and by martin j. head significantly improved the manuscript. this research was financially supported by the università degli studi di bari aldo moro: fondi di ateneo r. la perna 2010, and m. marino 2012. financial support was also provided by università degli studi di firenze (fondi di ateneo a. bertini 2011 and 2012, and a ph.d. fellowship to f. toti). special tanks to the montalbano jonico administration and communities which helped our research. the microscope laboratory at the dipartimento di scienze della terra and geoambientali, università degli studi di bari aldo moro, used for pictures of plate 1, was funded by potenziamento strutturale pona3_00369 “laboratorio per lo sviluppo integrato delle scienze e delle tecnologie dei materiali avanzati e per dispositivi innovativi (sistema)”. references aiello g., barra d., parisi r. (2015) lower-middle pleistocene ostracod assemblages from the fig. 4 participants at the field workshop on the lower-middle pleistocene transition in italy (bari 11-13 october, 2014; ciaranfi et al., 2015). the ideale section is visible in the background. 1 p. lombardi; 2 g. miraglia; 3 m. tropeano; 4 f. toti; 5 p. maiorano; 6 c. lin; 7 p. ferretti; 8 h. nirei; 9 a. negri; 10 r. la perna; 11 a. fusco; 12 n. ciaranfi; 13 d. scarponi ; 141 v. de vincenzis (mayor of montalbano jonico, 2014); 15 l. capraro; 16 s. gallicchio; 17 o. kazaoka; 18 y. suganuma; 19 c. turner; 20 m. marino; 21 s. nomade; 22 l. sabato; 23 n. combourieu nebout; 24 a. girone; 25 f. lirer; 26 m. okada; 27 a. sposato; 28 a. bertini; 29 p. petrosino; 30 m. head; 31 m. coltorti; 32 v. rosito. photo by g. vai. 131 the montalbano jonico section (south italy) ............ montalbano jonico section (basilicata, southern italy). quaternary international, 383, 47-73. doi: 10.1016/j.quaint.2014.11.010 balduzzi a., casnedi r., crescenti u., mostardini f., tonna m. (1982) il plio-pleistocene del sottosuolo del bacino lucano (avanfossa appenninica). geologica romana, 21, 89-111. barker s., knorr g., edwards r.l., rarrenin f., putnam a.e., skinner l.c., wolff e., ziegler m. (2011) 800,000 years of abrupt climate variability. science, 334, 347-351. bassinot f.c., labeyrie l.d., vincent f., quidelleur x., shackleton n.j., lancelot y. (1994) the astronomical theory of climate and the age of the brunhes-matuyama magnetic reversal. earth and planetary science letters, 126, 91-108. bertini a., toti f., marino m., ciaranfi n. (2015) vegetation and climate across the early-middle pleistocene transition at the montalbano jonico section (southern italy). quaternary international, 383, 7488. doi: 10.1016/j.quaint.2015.01.003 bintanja r., van de wal r.s.w. (2008) north american ice-sheet dynamics and the onset of 100,000-year glacial cycles. nature, 454, 869-872. doi: 10.1038/nature07158 brilli m., lerche j., ciaranfi n., turi b. (2000) evidence of precession and obliquity orbital forcing in oxygen 18 isotope composition of montalbano jonico section (basilicata, southern italy). applied radiation and isotope, 52, 957-964. capotondi l., girone a., lirer f., bergami c., verducci m., vallefuoco m., afferri a., ferraro l., pelosi n., de lange g.j. (2016) central mediterranean mid -pleistocene paleoclimatic variability and its association with global climate. palaeogeography, palaeoclimatology, palaeoecology, 442, 72-83. casnedi r. (1988) la fossa bradanica: origine, sedimentazione e migrazione. memorie società geologica italiana, 41, 439-448. channell j.e.t., kleiven h.f., 2000. geomagnetic paleointensities and astrochronological ages from the matuyama-brunhes boundaries and the boundaries of jaramillo subchron: paleomagnetic and isotope records from odp site 983. philosophical transaction of royal society of london, 358, 1027-1047. channell j.e.t., curtis j.f., flower b.p. (2004) the matuyama-bruhnes interval (500-900 ka) in north atlantic drift sediments. geophysical journal international, 158, 489-505. channell j.e.t., hodell d.a., singer b.s., xuan c. (2010) reconciling astrochronological and 40ar/39ar ages for the matuyama-brunhes boundary in the late matuyama chron. geochemistry, geophysics, geosystems, 11, q0aa12. doi: 0.1029/2010gc003203 ciaranfi n., d'alessandro a., marino m., sabato l. (1994) the montalbano jonico section in the bradanic foredeep (southern italy): a potential early-middle pleistocene boundary stratotype. contribution in cita & castradori (1994) "workshop on marine sections from the gulf of taranto (southern italy usable as potential stratotypes for the gssp of the lower, middle and upper pleistocene (bari, italy, sept. 29-oct. 4, 1994). il quaternario, 7, 677-692. ciaranfi n., marino m., sabato l., d'alessandro a., de rosa r. (1996) studio geologico stratigrafico di una successione infra e mesopleistocenica nella parte sudoccidentale della fosssa bradanica (montalbano ionico, basilicata). bollettino società geologica italiana, 115, 379-391. ciaranfi n., d'alessandro a., marino m. (1997) a candidate section for the lower-middle pleistocene boundary (apennine foredeep, south italy). in: naiwen w., remane j. (eds.), proceedings 30th international geological congress. 11, 201-211. ciaranfi n., d'alessandro a., girone a., maiorano p., marino m., soldani d., stefanelli s. (2001) pleistocene sections in the montalbano jonico area and the potential gssp for early-middle pleistocene in the lucania basin (southern italy). memorie di scienze geologiche, 53, 67-83. ciaranfi n., lirer f., lirer,l., lourens l.j., maiorano p., marino m., petrosino p., sprovieri m., stefanelli s., brilli m., girone a., joannin s., pelosi n., vallefuoco m. (2010) integrated stratigraphy and astronomical tuning of the lower-middle pleistocene montalbano jonico land section (southern italy). quaternary international, 210, 109-120. ciaranfi n., head m.j., marino m. (2015) report of the field workshop on the lower-middle pleistocene transition in italy. quaternary perspectives, 22(1), 12-14. cita m.b., capraro l., ciaranfi n., di stefano e., marino m., rio d., sprovieri r., vai g.b. (2006) calabrian and ionian: a proposal for a definition of mediterranean stages for lower and middle pleistocene. episodes, 29, 107-114. clement b.m. (2004) geographical distribution of transitional vgps: evidence for non-zonal symmetry during the matuyama-brunhes geomagnetic reversal. earth and planetary science letters, 104, 4858. christl m., strobl c., mangini a. (2003) beryllium-10 in deep-sea sediments: a tracer for the earth's magnetic field intensity during the last 200,000 years. quaternary science reviews, 22, 725-739. d'alessandro a., la perna r., ciaranfi n. (2003) response of macrobenthos to changes in paleoenvironment in the lower-middle pleistocene (lucania basin, southern italy). il quaternario, 16, 167-182. demenocal p.b., ruddiman w.f., kent d.v. (1990) depth of post-depositional remanence acquisition in deep-sea sediments: a case study of the brunhes-matuyama reversal and oxygen isotopic stage 19.1. earth and planetary science letters, 99, 113. di geronimo i., la perna r. (1997) pleistocene bathyal molluscan assemblages from southern italy. rivista italiana di paleontologia e stratigrafia, 103, 389-426. dreyfus g.b., raisbeck g.m., parrenin f., jouzel j., guyodo y., nomade s., mazaud a. (2008) an ice core perspective on the age of the matuyamabrunhes boundary. earth and planetary science 132 marino m. et al. tions, 247, 1-18. head m.j., gibbard p.l. (2015a) formal subdivision of the quaternary system/period: past, present, and future. quaternary international, 383, 4-35. head m.j., gibbard p.l (2015b) early-middle pleistocene transitions: linking terrestrial and marine realms. quaternary international, 389, 7-46. head m.j., pillans b., farquhar a. (2008) the earlymiddle pleistocene transition: characterization and proposed guide for the defining boundary. episodes, 31, 255-259. hyodo m., biawas d.k., noda t., tomioka n., mishima t., itota c., sato h. (2006) millennial to submillennial-scale features of the matuyama-brunhes geomagnetic polarity transition from osaka bay, southwestern japan. journal of geophysical research, 111, b02103. doi: 10.1029/2004jb003584 hyodo m., kitaba i. (2015) timing of matuyamabrunhes geomagnetic reversal: decoupled thermal maximum and sea-level highstand during marine isotope stage 19. quaternary international, 383, 136-144. doi: 10.1016/j.quaint.2015.01.052 hyodo m., matsu'ura s., kamishima y., kondo m., takeshita y., kitaba i., danhara t., aziz a., kurniawan i., kumaig h. (2011) high-resolution record of the matuyama-brunhes transition constrains the age of javanese homo erectus in the sangiran dome, indonesia. proceedings of natural academy of sciences of usa, 108, 19563-19568. doi: 10.1073/pnas.1113106108 joannin s., ciaranfi n., stefanelli s. (2008) vegetation changes during the late early pleistocene at montalbano jonico (province of matera, southern italy) based on pollen analysis. palaeogeography, palaeoclimatology, palaeoecology, 270, 92-101. jouzel j., masson-delmotte v., cattani o., dreyfus g., falourd s., hoffmann g., minster b., nouet j., barnola j.m., chappellaz j., fischer h., gallet j.c., johnsen s., leuenberger m., loulergue l., luethi d., oerter h., parrenin f., raisbeck g., raynaud d., schilt a., schwander j., selmo e., souchez r., spahni r., stauffer b., steffensen j.p., stenni b., stocker t.f., tison j.l., werner m., wolff, e.w. (2007) orbital and millennial antarctic climate variability over the past 800,000 years. science, 317, 793-796. kitaba i., hyodo m., katoh s., matsushita m. (2012) phase-lagged warming and the disruption of climatic rhythms during the matuyama-brunhes magnetic polarity transition. gondwana research, 21, 595-600. kleiven h., hall i.r., mccave i.n., knorr g., jansen e. (2011) north atlantic coupled deep-water flow and climate variability in the middle pleistocene. geology, 39 (4), 343-346. doi: 10.1130/g31651.1 larrasoaña j.c., roberts a.p., rohling e.j., winklhofer m., wehausen r. (2003) three million years of monsoon variability over the northern sahara. climate dynamics, 21, 689-698. leonhardt r., fabian k. (2007) paleomagnetic reconstruction of the global geomagnetic field evolution during the matuyama/brunhes transition: iterative bayesian inversion and independent verification. letters, 274, 151-156. florindo f., karner d.b., marra f., renne p.r., roberts a.p., weaver r. (2007) radioisotopic age constraints for glacial terminations ix and vii from aggradational sections of the tiber river delta in rome, italy. earth and planetary science letters, 256, 61-80. frank m., schwarz b., baumann s., kubik p.w., suter m., mangini a. (1997) a 200 kyr record of cosmogenic radionuclide production rate and geomagnetic field intensity from 10be in globally stacked deep-sea sediments. earth and planetary science letters, 149, 121-129. giaccio b., regattieri e., zanchetta g., nomade s., renne p.r., sprain c.j, drysdale r.n., tzedakis p.c., messina1 p., scardia g., sposato a., bassinot f. (2015) duration and dynamics of the best orbital analogue to the present interglacial. geology, 43, 603-606. doi: 10.1130/g36677.1 girone a., varola a. (2001) fish otoliths from the middle pleistocene deposits of montalbano jonico (southern italy). bollettino società paleontologica italiana, 40, 431-443. girone a., capotondi l., ciaranfi n., di leo p., lirer f., maiorano p., marino m., pelosi n., pulice i. (2013 a) paleoenvironmental change at the lower pleistocene montalbano jonico section (southern italy): global versus regional signals. palaeogeography, palaeoclimatology, palaeoecology, 371, 62-79. girone a., maiorano p., marino m., kucera m. (2013 b) calcareous plankton response to orbital and millennial-scale climate changes across the middle pleistocene in the western mediterranean. palaeogeography, palaeoclimatology, palaeoecology, 392, 105-116. gofas s., rueda j.l., salas c., díaz-del-río v. (2010) a new record of the giant deep-sea oyster neopycnodonte zibrowii in the gulf of cadiz (south -western iberian peninsula). marine biodiversity records, 3, e72, 1-4. doi:10.1017/s1755267210000618 gooday a.j., alt c.h.s., jones d.o.b., shale d., marsden k., brasier m.d. (2013) the ecology and biogeography of discospirina tenuissima (foraminifera) in the atlantic and indian oceans. deep-sea research ii, 98, 301-314. gradstein f. m., finney s. c., lane r., ogg j. g. (2003) ics on stage. lethaia. 36, 371-377. hardenbol j., thierry j., farley m.b., jacquin t., de graciansky p.-c., vail p.r. (1998) mesozoic and cenozoic sequence chronostratigraphic framework of european basins. in: de graciansky, p.c., hardenbol, j., jacquin, t., vail, p.r. (eds.), mesozoic and cenozoic sequence stratigraphy of european basins, sepm special publication, 60, 3-13. haq b.u., handerbol j., vail p. (1987) chronology of fluctuating sea levels since the triassic. science, 235, 1156-1167. head m.j., gibbard p.j. (2005) early-middle pleistocene transition: an overview and recommendation for the defining boundary. in: head m.j., gibbard p.l. (eds.), early-middle pleistocene transitions: geological society of london, special publica 133 the montalbano jonico section (south italy) ............ earth and planetary science letters, 253, 172195. lisiecki l.e., raymo m.e. (2005) a pliocenepleistocene stack of 57 globally distributed benthic δ18o records. paleoceanography, 20, pa1003. maiorano p., marino m. (2004) calcareous nannofossil bioevents and environmental control on temporal and spatial pattern at the early-middle pleistocene. marine micropaleontology, 53, 405-422. maiorano p., marino m., di stefano e., ciaranfi n. (2004) calcareous nannofossil events in the lower-middle pleistocene transition at the montalbano jonico section and odp site 964: calibration with isotope and sapropel stratigraphy. rivista italiana di paleontologia e stratigrafia, 110, 547557. maiorano p., aiello g., barra d., di leo p., joannin s., lirer f., marino m., pappalardo a., capotondi l., ciaranfi n., stefanelli s. (2008) paleoenvironmental changes during sapropel 19 (i-cycle 90) deposition: evidences from geochemical, mineralogical and microplaoentological proxies in the mid pleistocene montalbano jonico land section (southern italy). palaeogeography, palaeoclimatology, palaeoecology, 257, 308-334. maiorano p., capotondi l., ciaranfi n., girone a., lirer f., marino m., pelosi n., petrosino p., piscitelli a. (2010) vrica-crotone and montalbano jonico sections: a potential unit-stratotype of the calabrian stage. episodes, 33, 218-233. maiorano p., tarantino f., marino m., de lange g.j. (2013) paleoenvironmental conditions at core kc01b (ionian sea) through mis 13-9: evidence from calcareous nannofossil assemblages. quaternary international, 288, 97-111. maiorano p., bertini a., capolongo d., eramo g., gallicchio s., girone a., pinto d., toti f., ventruti g., marino m. (2016) climate signatures through the marine isotope stage 19 in the montalbano jonico section (southern italy): a land-sea perspective. palaeogeography, palaeoclimatology, palaeoecology, submitted. marino m. (1996) quantitative nannofossil biostratigraphy of the lower-middle pleistocene montalbano jonico section, southern italy. paleopelagos, 6, 347-360. marino m., bertini a., ciaranfi n., aiello g., barra d., gallicchio s., girone a., la perna r., lirer f., maiorano p., petrosino p., toti f. (2015) paleoenvironmental and climatostratigraphic insights for marine isotope stage 19 (pleistocene) at the montalbano jonico section, south italy. quaternary international, 383, 104-115. doi: 10.1016/j.quaint.2015.01.043 nomade s., bassinot f., ciaranfi n., dewilde f., scao v., girone a., maiorano p., marino m., toti f., giaccio b., combourieu nebout n., bertini a., petrosino p. (2015) high resolution δ18o stratigraphy along the mis 19 in montalbano jonico (basilicata, southern italy): exploring the landocean linkages during a low eccentricity interglacial. nagoya 2015 xix inqua. abstract no. t02206 petrosino p., jicha b.r., mazzeo f.c., ciaranfi n., girone a., maiorano p., marino m. (2015) the montalbano jonico marine succession: an archive for distal tephra layers at the early-middle pleistocene boundary in southern italy. quaternary international, 383, 89-103. doi: 10.1016/j.quaint.2014.10.049 pillans b. (2003) subdividing pleistocene using the matuyama-brunhes boundary (mbb): an australasian perspective. quaternary science reviews, 22, 1569-1577. pol k., masson-delmotte v., johnsen s., bigler m., cattani o., durand g., falourd s., jouzel j., minster b., parrenin f., ritz c., steen-larsen h. c., stenni b. (2010) new mis 19 epica dome c high resolution deuterium data: hints for a problematic preservation of climate variability in the “oldest ice”. earth and planetary science letters, 298, 95-103. doi: 10.1016/j.epsl.2010.07.030, 2010 raisbeck g.m., yiou f., cattani o., jouzel j. (2006) 10be evidence for the matuyama-brunhes geomagnetic reversal in the epica dome c ice core. nature, 444, 82-84. remane j., basset m.g., cowie j.f., gohrbandt k.h., lane h.r., michelsen o., naiwen w. (1996) revised guidelines for the establishment of global chronostratigraphic standards by the international commission on stratigraphy (ics). episodes, 19, 77-81. richmond c.m. (1996) the inqua approved provisional lower-middle pleistocene boundary. in: turner c. (ed.), the early-middle pleistocene in europe. balkema, rotterdam, 319-327. roberts a.p., tauxe l., heslop d. (2013) magnetic paleointensity stratigraphy and high resolution quaternary geochronology: successes and future challenges: quaternary science reviews, 61, 116. doi: 10.1016/j.quascirev.2012.10.036 sagnotti l., scardia g., giaccio b., liddicoat j.c., nomade s., renne p.r., sprain c.j. (2014) extremely rapid directional change during matuyamabrunhes geomagnetic polarity reversal. geophysical journal international, 199,1110-1124. doi: 10.1093/gji/ggu287 shackleton n. j., berger a., peltier w. r. (1990) an alternative astronomical calibration of the lower pleistocene timescale based on odp site 677, trans. r. soc. edinburgh, 81, 251-261. snedden j.w., liu c. (2010) a compilation of phanerozoic sea-level change, coastal onlaps and recommended sequence designations. american association petroleum geologists, 3 pp. h t t p : / / w w w . s e a r c h a n d d i s c o v e r y . c o m / documents/2010/40594snedden/ndx_snedden.pdf. snowball i., mellström a., ahlstrand e., haltia e., nilsson a., ningb w., muscheler r., brauer a. (2013) an estimate of post-depositional remanent magnetization lock-in depth in organic rich varved lake sediments. global and planetary change, 110, 264-277. stefanelli s. (2003) benthic foraminiferal assemblages as tools for paleoenvironmental reconstruction of 134 marino m. et al. ms. received: december 18, 2015 final text received: april 13, 2016 wagner g., masarik j., beer j., baumgartner s., imboden d., kubik p.w., synal h.a., suter m. (2000) reconstruction of the geomagnetic field between 20 and 60 kyr bp from cosmogenic radionuclides in the grip ice core. nucl. instrum. meth. phys. res. b beam interact. mater. atoms, 172, 597604. wang x., yang z., lovlie r., sun z., pej j. (2006) the magnetostratigraphic reassessment of correlation between chinese loess and marine oxygen isotope records over the last 1.1 ma. physics of the earth and planetary interiors, 159, 109-117. wisshak m., lópez correa m., gofas s., salas c., taviani m., jakobsen j., freiwald a. (2009) shell architecture, element composition, and stable isotope signature of the giant deep-sea oyster neopycnodonte zibrowii sp. n. from the ne atlantic. deep-sea research i, 56, 374-407. wright a.k., flower b.p. (2002) surface and deep ocean circulation in subpolar north atlantic during the mid-pleistocene revolution. paleoceanography, 17, 1068. doi: 1029/2002pa000782 yang t., hyodo m., yang z., li h., maeda m. (2010) multiple rapidly polarity switches during the matuyama-brunhes (m/b) transition from two high resolution loess paleosol records. geophysical journal international, 115, b05101. doi: 10.1029/2009jb006301 yin q.z., berger a. (2012) individual contribution of insolation and co2 to the interglacial climates of the past 800,000 years. climate dynamics, 38, 709-724. doi: 10.1007/s00382-011-1013-5 the early-middle pleistocene montalbano jonico composite section. bollettino della società paleontologica italiana, 42, 281-299. stefanelli s. (2004) cyclic stages in oxygenation based on foraminiferal microhabitats: early-middle pleistocene, lucania basin, southern italy. journal of micropaleontology, 23, 81-95. stefanelli s., capotondi l., ciaranfi n. (2005) foraminiferal record and environmental changes during the deposition of early-middle pleistocene sapropels in southern italy. palaeogeography, palaeoclimatology, palaeoecology, 216, 27-52. suc j.p., combourieu-nebout n., seret g., popescu s.a., klotz s., gautier f., clauzon g., westgate j., insinga d., sandhu a.s. (2010) the crotone series: a synthesis and new data. quaternary international, 219, 121-133. suganuma y., yokoyama y., yamazaki t., kawamura k., horng c.s., matsuzaki h. (2010) 10be evidence for delayed acquisition of remanent magnetization in marine sediments: implications for a new age for the matuyama-brunhes boundary. earth and planetary science letters, 296, 443450. doi:10.1016/j.epsl.2010.05.031 suganuma y., okuno j., heslop d., roberts a.p., yamazaki t., yokoyama y. (2011) postdepositional remanent magnetization lock-in for marine sediments deduced from 10be and paleomagnetic records through the matuyama-brunhes boundary: earth and planetary science letters, 311, 39-52. doi:10.1016/j.epsl.2011.08.038 toti f. (2015) interglacial vegetation patterns at the early-middle pleistocene transition: a point of view from montalbano jonico section (southern italy). alpine and mediterranean quaternary, 28(2), 2015, 131-143. tzedakis p.c., channell j.e.t., hodell d.a., kleiven h.f., skinner l.c. 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can be opened with acrobat and adobe reader 5.0 and later.) >> /namespace [ (adobe) (common) (1.0) ] /othernamespaces [ << /asreaderspreads false /cropimagestoframes true /errorcontrol /warnandcontinue /flattenerignorespreadoverrides false /includeguidesgrids false /includenonprinting false /includeslug false /namespace [ (adobe) (indesign) (4.0) ] /omitplacedbitmaps false /omitplacedeps false /omitplacedpdf false /simulateoverprint /legacy >> << /addbleedmarks false /addcolorbars false /addcropmarks false /addpageinfo false /addregmarks false /convertcolors /converttocmyk /destinationprofilename () /destinationprofileselector /documentcmyk /downsample16bitimages true /flattenerpreset << /presetselector /mediumresolution >> /formelements false /generatestructure false /includebookmarks false /includehyperlinks false /includeinteractive false /includelayers false /includeprofiles false /multimediahandling /useobjectsettings /namespace [ (adobe) (creativesuite) (2.0) ] /pdfxoutputintentprofileselector /documentcmyk /preserveediting true /untaggedcmykhandling /leaveuntagged /untaggedrgbhandling /usedocumentprofile /usedocumentbleed false >> ] >> setdistillerparams << /hwresolution [2400 2400] /pagesize [612.000 792.000] >> setpagedevice sess 1_160211.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 new archaeological and geomorphological markers along the istrian coasts (croatia) and their relations with relative sea level changes stefano furlani1,2, sara biolchi2,3, rita auriemma4, giorgio tunis2, franco cucchi2 & fabrizio antonioli5 1dipartimento di geografia “g. morandini”, università degli studi di padova, italy 2dipartimento di geoscienze, università degli studi di trieste, italy 3dipartimento di scienze della terra, università degli studi di modena e reggio emilia, italy 4dipartimento di beni culturali, università di lecce, italy 5enea, acs, roma, italy corresponding author: s. furlani <sfurlani73@gmail.com> abstract: furlani s. et al., new archaeological and geomorphological markers along the istrian coasts (croatia) and their relations with relative sea level changes. (it issn 0349-3356, 2011) new data on archeological remains and coastal morphologies have been used to refine published data on the lateholocene relative sea-level change along the northeastern ardriatic coasts. data have been compared with predicted curves, in order to detail the tectonic evolution of the studied area. riassunto: furlani s. et al., segnalazione di nuovi indicatori archeologici e geomorfologici lungo la costa istriana (croazia) e correlazione con le variazioni relative di livello marino. (it issn 0349-3356, 2011) le variazioni di livello marino tardo-oloceniche lungo le coste nordorientali dell’adriatico sono state dedotte da una serie di nuove misure effettuate su indicatori archeologici e geomorfologici sommersi. i dati raccolti sono stati comparati con le curve predette di risalita del livello del mare. key words: sea level changes, late-holocene, geoarchaeology, istria, northeastern adriatic parole chiave: variazioni di livello marino, tardo-olocene, geoarcheologia, istria, adriatico nordorientale the gulf of trieste and the istrian coasts have been extensively studied during the last decade (fouache et al., 2000; antonioli et al., 2004, 2007; faivre and fouache, 2003; faivre et al., 2011; furlani et al., 2011). neverthless, many sites remain unstudied from the point of view of sea level changes. cited authors reported along the limestone coasts between the gulf of trieste (italy) and istria (croatia) the quasi-continuous occurence of a submerged marine notch at a depth ranging between –0.5 m and –2.8 m, while roman age archaeological remains were measured at depths usually deeper than the altitude of the notch. we aim at detailing the late-holocene, in particular since roman-age, tectonic behaviour of the studied area following the methodological steps suggested first by antonioli et al. (2007). 1. study area from a geodynamical point of view, the study area belongs to the external dinarides. it is characterized by a diffuse nw-se orientation of the tectonic structures. along the northeastern adriatic coast crop out limestones belonging to the adriatic carbonate platform and spanning in time from lower jurassic fig. 1. the study area and the surveyed sites l’area di studio con i siti indagati 35 37 36 (toarcian) to eocene (vlahović et al., 2005). previous works recognized the occurrence in the ne adriatic sector of a nw tilting along different geological time scales: pendulum data (braitenberg et al., 2005), geomorphological markers (antonioli et al., 2004, 2007), archeological markers (degrassi et al., 2008) are evidence of recent tilting, while geophysical data (busetti et al., 2010), structural data (carulli et al., 1980) and gravity modeling (coren et al., 2006), indicate that the tilting is regional and long lasting. moreover, the dataset suggests that the southern side of the gulf has subsided, at least since roman time (about 0.6 mm/y), while the northern side has subsided during the holocene, probably faster than the southern side (up to 1.99 mm/y, even if probably this value is mainly due to high sedimentation rates), following the aforementioned tilting (furlani et al., 2011). 2. the investigated sites and their significance on local tectonics six new submerged archaeological and geomorphological markers have been surveyed, one in italy and the remnants in istria (croatia). in particular: 1) submerged structure at sistiana (trieste, italy). the functionality of the structure is not completely understood yet, since it is inclined toward the sea. since the presence of quarries, which are active since roman age, located just near the site, it could be a “slide” to charge limestone blocks on the ships. its altitude ranges between -1.0 m and 5.0 m; 2) coastal quarry at palud (pula, croatia). the structure shows the proofs of human quarrying on limestone blocks. the base level of the quarry is covered by cementitium (maybe used to level off the pavement) and it is at about -0.2/-0.3 m m.s.l. fig. 2,submerged dock at barbariga il molo sommerso di barbariga s. furlani et al. 37 ms. received: testo ricevuto il offshore there is another human-made basement; 3) submerged “path” at kolone (bale, croatia). a submerged path, at about -1.5 m m.s.l., connects the coast to a small island. it is about 100 m long; 4) submerged dock at barbariga (croatia). the state of conservation is bad. the altitude of the structure is about -1.5 m; 5) submerged beachrock at brijuni. its depth ranges between about -5.0 and about -1.5 m. its morphology suggests that the structure is a beachrock; 6) coastal quarry at sekovac (premantura, croatia). the structure evidences the proofs of human quarrying on limestone blocks. the altitude is similar to the quarry located at palud. the comparison between published and these new data refines the knowledge on late holocene sea level change in istria. the large number of structures already surveyed in the area allows to usefully integrate the available data, despite the bad state of conservation of the studied markers and the large uncertainty on their functionality. the most useful sea level marker is the roman dock at barbariga. the mean values of the tide and pressure-corrected archaeological measurements suggest a depth of -1.6±0.5 m for the 2 ky bp sea level (roman age – i sec. a.d.). considering the recent position of the submerged road at bale, the same relative sea level rise rate seems to affect even the area located toward north. the altitude of the quarries represents an upper limit for the roman age sea level, however values agree with the other considerations. comparison between the position of the submerged markers and the predicted values of sea level rise for the northern adriatic sea details data collected by previous authors and confirms the negative tectonic rate (-0.7/-0.8 mm/yr) for the whole studied area. acknowledgements we are kindly grateful to dr. sandro duijmović and eduard kolić of the brijuni national park (croatia) for the surveyings along the coasts of the park. references antonioli f., carulli g.b., furlani s., auriemma r. & marocco r. (2004) the enigma of submerged marine notches in northern adriatic sea. quaternaria, 8, 27–36. antonioli f., anzidei m., lambeck k., auriemma r., gaddi d., furlani s., orru’ p., solinas e., gaspari a., karinja s., kovacic v. & surace l. (2007) sea level change during holocene from sardinia and northeastern adriatic (central mediterranean sea) from archaeological and geomorphological data. quaternary science reviews, 26, 2463–2486. braitenberg c., nagy i., romeo g. & taccetti q. (2005) the very broad-band data acquisition of the long-base tiltmeters of grotta gigante (trieste, italy), journal of geodynamics, 41, 164-174. busetti m., volpi v., nicolich r., barison e., romeo r., baradello l., brancatelli g., giustiniani m., marchi m., zanolla c., nieto d., ramella r. & wardell, n. (2010) dinaric tectonic features in the gulf of trieste (northern adriatic), proceedings of the “27° convegno nazionale del gruppo nazionale di geofisica della terra solida (gngts)”, trieste (italy), 6-8 october 2008. bollettino di geofisica teorica e applicata, 51 (2, 3), 117-128. carulli g.b., carobene l., cavallin a., martinis, b. & onofri r. (1980) – evoluzione strutturale plioquaternaria del friuli e della venezia giulia, contrib. prelim. realizz. carta neotettonica d’italia, pubbl. 356 del prog. finalizz. geodinamica, unità operat. 6.2.10, 489-545. coren f., marson i., creati n., prodan m., palmieri f. & zanolla, c. (2006) – structural setting of the trieste area from gravity modeling, bollettino di geofisica teorica ed applicata, 47 (4), 549-555. degrassi v., furlani s., scotti f.m., melis r., antonioli f. & fonda, g. (2008) – strutture portuali di via dei cavazzeni (trieste): indicazioni sul livello del mare, terre di mare. l’archeologia dei paesaggi costieri e le variazioni climatiche. a cura di: r. auriemma, s. karinja, udine, atti del convegno interreg internazionale di studi, trieste, 8-10 novembre 2007, 275-281. faivre s. & fouache e. (2003) some tectonic influences on the croatian shoreline evolution in the last 2000 years. zeitschrift für geomorphologie nf 47 (4), 521-537. faivre s., fouache e., ghilardi m., antonioli f., furlani s. & kovacic v. (2011) relative sea level change in istria (croatia) during the last 5 ka. quaternary international, in press. fouache e., faivre s., dufaure j.-j., kovacic v. & tassaux f. (2000) new observations on the evolution of the croatian shoreline between pore_c and zadar over the past 2000 years. zeitschrift für geomorphologie supplement-band, 122, 33-46. furlani s., biolchi s., cucchi f., antonioli f., busetti m. & melis r. (2011) tectonic effects on lateholocene sea level changes in the gulf of trieste (ne adriatic sea, italy). quaternary international. in press. vlahovic i., tisljar j., velic i. & maticec d. (2005) evolution of the adriatic carbonate platform: paleogeography, main events and depositional dynamics, palaeogeography, palaeoclimatology, palaeoecology, 220, 333-360. new archaeological and geomorphological markers along ... january 15, 2011 15 gennaio 2011 imp. guglielmin ppeerrmmaaffrroosstt ee ffoorrmmee ppeerriiggllaacciiaallii nneellllee nnoorrtthheerrnn ffooootthhiillllss ((bbaaiiaa tteerrrraannoovvaa,, tteerrrraa vviittttoorriiaa sseetttteennttrriioonnaallee,, aannttaarrttiiddee)) mmaauurroo gguugglliieellmmiinn11,, hhuunngg mm.. ffrreenncchh22 && ffrraanncceessccoo ddrraammiiss33 1prna, via g. matteotti, 22, 20035 lissone (mi), italia 2department of geography and earth sciences, university of ottawa, ottawa, ontario k1n 6n5, canada 3dipartimento di scienze geologiche, università “roma tre”, largo s. leonardo murialdo, 1, 00146 roma, italia riassunto permafrost e forme periglaciali nelle northern foothills (baia terranova, terra vittoria settentrionale, antartide) le forme periglaciali presenti nel territorio di baia terra nova sono rappresentate essenzialmente da poligoni, fessure da gelo (frost fissures) e coni di iniezione (injection cones). i poligoni, sviluppati su i terreni del younger drift, sono caratterizzati dalla presenza di cunei di ghiaia e sabbia (gravel and sand wedges) mentre su i terreni riferibili all’older drift sono stati rinvenuti cunei e vene di ghiaccio (ice wedges and veins). la contrazione termica responsabile della formazione di ambedue i tipi di cunei risulta attiva anche nelle attuali condizioni climatiche. i coni di iniezione sono comunemente associati a laghi perennemente gelati e vengono interpretati come forme dovute all’iniezione di acqua nel permafrost, così come accade in artico per la genesi dei pingo e dei ghiacciamenti superficiali (icings). notevole importanza per la dinamica morfologica dell’area riveste il numero di cicli di gelo e disgelo che si alternano nel terreno. l’azione del crioclastismo (frost shattering) non è però molto diffusa ed anche il fenomeno di fessurazione per gelo (frost wedging) nel substrato roccioso è limitato all’azione di espansione delle discontinuità naturali preesistenti. abstract permafrost and frozen phenomena of the northern foothills (terranova bay, northern victoria land, antarctica) permafrost-related landforms in the terra nova bay territory are mainly polygons, frost fissures, and injection cones. the polygons developed on younger drift are characterized by gravelly-sandy filling while those affecting older drift show the occurrence of ice wedges and veins. thermal contraction responsible for the genesis of both landforms shows to be active at present. injection cones are commonly associated to perennially frozen lakes. they are interpreted as landforms due to the injection of water into the permafrost as it happens for the genesis of pingos and seasonal icings in the arctic. a relevant role in the morphodynamic context of the area is that plaid by the high number of freezing/thawing cycles in the ground. however, frost shattering is not widespread and even frost-wedging in the bedrock is only restricted to the expansion of the pre-existing natural discontinuities. parole chiave: permafrost, poligoni da fessure da gelo, coni di iniezione, cunei di ghiaccio, antartide. keywords: permafrost, frost fissure polygons, injection cones, ice wedges, antarctica. il quaternario italian journal of quaternary sciences 1166(2), 2003, 151-157 11.. iinnttrroodduuzziioonnee il progetto nazionale di ricerche in antartide (pnra), avviato nel 1985, ha affrontato essenzialmente nelle sue prime fasi di svolgimento temi legati al glacialismo e all’evoluzione delle spiagge oloceniche; solo a partire dal 1996 è stato approvato un progetto focalizzato sulla distribuzione del permafrost e sul suo regime termico nel territorio di baia terranova (terra vittoria settentrionale), sede della base scientifica italiana in antartide. questo territorio è contraddistinto da una alta percentuale di aree deglaciate, una tra più elevate del continente antartico, se si eccettuano le dry valleys e la penisola antartica. i valori della temperatura media mensile variano tra –1,5 °c in gennaio e –22,5 °c in agosto; la temperatura media annua è di -14,7 °c (nel periodo 1987-1994). i venti dominanti provengono dai quadranti occidentali con velocità che spesso superano i 17 nodi (baroni, 1996); le precipitazioni a carattere interamente nevoso vengono stimate attorno i 270 mm/anno (piccardi et al., 1994). nei mesi di novembre e dicembre 1998 è stata svolta, in collaborazione con l’università di ottawa, una campagna di ricerche morfologiche avente come obiettivo principale lo studio della geomorfologia periglaciale nelle northern foothills, in prossimità della base italiana (fig.1). nel presente lavoro vengono illustrati i primi risultati delle indagini suddette con particolare riguardo alle forme generate nell’area da processi criogenici connessi con la presenza di permafrost continuo. 22.. iill ppeerrmmaaffrroosstt aa bbaaiiaa tteerrrraannoovvaa si definisce permafrost un qualsiasi materiale che rimane congelato per almeno due anni consecutivi (muller, 1959) indipendentemente dalla sua natura e dal contenuto o meno di ghiaccio al suo interno. nell’area in esame sono presenti diversi tipi di permafrost: depositi glaciali sovrastanti corpi di ghiaccio relitto massivo (simpson crags; boulder clay glacier); depositi glaciali rimaneggiati da soli/geliflusso sovrastanti il substrato roccioso; 152 m. guglielmin, h.m. french & f. dramis substrato roccioso ricoperto da uno strato sottile e discontinuo di depositi glaciali e ubicato a quote superiori a quelle dell’ultimo massimo glaciale (350-400 m s.l.m); substrato roccioso ubicato a quote più basse di tale limite; cordoni morenici olocenici e rock glaciers; spiagge oloceniche sollevate isostaticamente. a partire dal 1996 è in funzione nell’area una stazione automatica di monitoraggio del regime termico del permafrost (guglielmin & dramis, 1998). la stazione, ubicata sul boulder clay glacier, alla quota di 205 m s.l.m., circa 5 km a sud della base di baia terra nova, registra i valori orari, della radiazione solare incidente, della temperatura dell’aria a 4 m di altezza sul terreno e della temperatura del suolo a sei diverse profondità. i primi due sensori sono posti a 2 e 30 cm di profondità all’interno di un till di ablazione, il terzo è posto a -60 cm, immediatamente al di sotto del limite superiore del ghiaccio massivo che caratterizza il sottosuolo dell’area. i rimanenti tre (posti rispettivamente a -160, -260 e -360 cm) sono ubicati all’interno del ghiaccio, del quale è stata determinata la diffusività termica pari a 0,106 °c/m2. in base a questo valore la profondità della minima variazione termica annua (zero annual amplitude zaa) risulta ubicata a circa -11 m, con una temperatura di -15°c. 33.. rreeggiimmee tteerrmmiiccoo ddeelllloo ssttrraattoo aattttiivvoo lo strato attivo è per definizione la porzione più superficiale del permafrost, interessata da periodici scongelamenti stagionali e ne rappresenta quindi la parte termicamente più dinamica e più efficace sotto l’aspetto morfogenetico. il regime termico dello strato attivo è infatti importante per la genesi e l’evoluzione di diverse forme direttamente legate al permafrost oltre che di alcune forme dovute a meccanismi di geliflussione. nell’area in esame lo spessore dello strato attivo è piuttosto esiguo, essendo in genere compreso tra i 15 e i 20 cm anche se localmente, specie nelle spiagge oloceniche e sui pendii settentrionali più ripidi con roccia affiorante, si ritiene che possa arrivare sino ad 1 m o poco più. in particolare l’andamento del regime termico di boulder clay glacier è mostrato in fig. 2, mentre i valori massimi, minimi e medi delle temperature registrate nel 1996-97 alle diverse profondità sono illustrati in tab. 1a. notevole importanza per la dinamica morfologica del permafrost riveste il numero di cicli di gelo e disgelo che si alternano nel terreno. in tab. 1b è illustrato l’andamento giornaliero dei cicli alla profondità di 2 cm, calcolati rispettivamente per un punto di congelamento pari a 0, -2 e –4 °c (valori legati alla presenza di elevati tenori salini nella neve e nel suolo). come è possibile osservare nella tabella il numero di cicli di gelo e disgelo registrati risulta rilevante e maggiore di quanto misurato nella maggior parte degli ambienti periglaciali (french, 1996). l’azione del crioclastismo (frost shattering) non è però molto diffusa ed anche il fenomeno di fessurazione per gelo (frost wedging) nel substrato roccioso è limitato all’azione di espansione delle discontinuità naturali preesistenti. fig. 1 ubicazione delle forme investigate: suoli strutturati (stelle nere) e cunei di iniezione (triangoli neri) a northern foothills e vicino alla base italiana di baia terra nova, antartide. locations of the i n v e s t i g a t e d landforms: patterned grounds (black stars) and frost heaved mounds (black triangles) of the northern foothil ls and near terra nova bay station, an-tarctica. 153permafrost e forme periglaciali ... t °c t °c t °c t °c t °c t °c t °c -360 cm -260 cm -160 cm -60 cm -30 cm -2 cm aria massimo -10,2 -8,3 -4,4 -2,4 -1,1 10,7 5,4 minimo -23,7 -24,9 -27,7 -29 -30,2 -35,3 -38 media -17,45 -17,28 -17,08 -16,98 -16,83 -16,9 -16,06 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 dic. ’96 >0°c 0 0 0 0 0 0 0 0 1 0 0 0 1 1 2 0 0 0 3 0 0 2 1 1 0 0 0 0 3 1 1 >-2°c 1 1 2 2 0 0 3 0 0 5 0 0 1 2 1 2 1 2 3 1 1 2 0 2 2 2 3 1 4 1 2 >-4°c 2 1 1 0 3 1 1 1 2 0 4 3 1 0 2 2 2 2 1 1 1 2 0 0 0 1 1 0 0 0 0 gen.’97 >0°c 4 0 5 2 0 0 0 0 0 0 0 0 0 2 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 >-2°c 0 3 1 1 1 3 2 0 2 2 2 0 3 2 2 4 3 1 0 2 1 3 2 0 0 0 1 0 0 0 0 >-4°c 0 0 0 0 1 1 1 2 1 0 3 2 1 0 0 1 1 1 2 1 1 2 3 4 2 1 2 0 1 1 1 feb.’97 >0°c 0 0 0 0 0 >-2°c 0 0 0 0 0 >-4°c 1 0 0 1 1 nov.’97 >0°c 0 0 0 0 0 0 0 0 0 0 0 2 3 2 0 0 0 2 1 0 0 0 0 >-2°c 0 0 3 0 0 0 0 0 1 0 0 2 1 2 0 0 0 3 0 1 0 0 0 >-4°c 2 2 1 3 1 0 1 2 1 2 1 0 0 0 3 1 1 0 0 2 0 0 0 tab. 1 temperature del terreno registrate dal 1 dicembre 1996 al 7 novembre 1997 alla stazione di monitoraggio di boulder clay glacier. ground temperatures recorded at boulderclay glacier monitoring site, december 1, 1996 november 7, 1997. 1b) frequenza giornaliera delle oscillazioni termiche attraverso le temperature di 0 c°, -2 c° e –4 °c, usando i valori medi orari: totale > 0°c = 42; >-2°c = 100; > -4°c = 97. 1b) number of daily occurrences per day of ground temperature cycles passing 0 c°, -2 c°, and –4 c°, using hourly data: total > 0 c° = 42; >-2 c° = 100; > -4 c° = 97 1a) valori massimi, minimi e medi (°c). 1a) maximum, minimum and average temperatures (c°). fig. 2 regime termico del permafrost presso la stazione di monitoraggio di boulder clay glacier del periodo 1996-97 (da guglielmin & dramis, 1998). ground temperature regime at boulder clay glacier permafrost monitoring station, 199697 (from guglielmin & dramis, 1998). ggiioorrnnii ((11 ddiicceemmbbrree 11999966 - 11 ddiicceemmbbrree 11999977)) pp rroo ffoo nndd iittàà (( ccmm )) 154 44.. ppoolliiggoonnii ddii ffeessssuurree ddaa ggeelloo una delle forme più diffuse nelle aree deglaciate delle northern foothills è quella dei suoli strutturati poligonali (non sorted polygons). queste forme, già descritte nella letteratura precedente (péwé, 1959; black & berg, 1966, black 1973; bondesan et al., 1997*), interessano sia i depositi glaciali dello younger drift (sovrastanti ghiaccio morto), sia i depositi glaciali dell’older drift (sovrapposti al basamento rocccioso), sia le spiagge oloceniche. i poligoni sono caratterizzati da diametri di 15-20 m e da solchi perimetrali di larghezza compresa tra 1e 2 m e profondità media di 0,5 m. bisogna inoltre sottolineare come non siano in realtà visibili fessure aperte sulla superficie ma solamente allineamenti preferenziali di massi e ciottoli. la rete generata da questi poligoni è essenzialmente di due tipi: random-ortogonale ed esagonale. talora sono stati osservati anche pattern diversi di tipo rettilineo come quello di simpson crags, che sembra essere controllato dalla presenza sottostante di crepacci nel ghiaccio morto massivo. lo stesso tipo di pattern rettilineo è stato osservato anche presso capo sastrugi, dove sono visibili numerose fessure, con una spaziatura regolare tra gli 8 e i 12 m, e ortogonali rispetto alla direzione di elongazione della dorsale rocciosa. con ogni probabilità il pattern delle fessure è in questo caso influenzato dall’assetto strutturale delle fratture nel substrato roccioso uno dei cui set principali presenta una direzione coincidente con quella prevalente delle fessure stesse. in tutte le sezioni eseguite la parte più superficiale delle fessure risulta riempita da ghiaia e ciottoli con struttura openwork. i clasti risultano nettamente isoorientati secondo la direzione delle fessure e spesso verticalizzati. da un punto di vista dinamico è da ritenere che queste forme siano attive anche ai giorni nostri per diverse ragioni. una evidenza dell’attività della fessurazione da gelo (frost cracking) durante la stagione invernale è rappresentata dall’osservazione (con l’ausilio di una sonda metallica) di fessure aperte in profondità (fino oltre 80 cm presso simpson crags e fino a 15 cm presso m. browning). un’altra testimonianza della contemporaneità del processo di fessurazione è data dal ritrovamento della prosecuzione delle fessure attraverso corpi di ghiaccio di rigelo stagionale (simpson crags). la maggior parte dei poligoni osservati non presenta cunei di ghiaccio al di sotto dei solchi mostrando invece cunei di ghiaia e sabbia a sezione triangolare, con larghezza compresa tra 0,5 e 1 m e di analoga profondità. i sedimenti suddetti hanno la stessa composizione litologica dei depositi circostanti anche se, in generale, con un’arricchimento nella frazione sabbiosa. la presenza di cunei di ghiaccio è stata riscontrata solamente sul m. browning, alla quota di 720 m s.l.m., su un till di ablazione sovrastante il substrato roccioso. in questa località sono presenti poligoni poco sviluppati e delineati solamente da piccoli solchi con ciottoli allineati e verticalizzati. in base al colore della matrice del till (5yr 5/6; 2.5 yr 5/6) e tenuto conto dell’assenza di clasti di vulcaniti provenienti dal m. melbourne, si ritiene che questo deposito sia da riferire al “older drift” definito da orombelli et al. (1991). i cunei di ghiaccio sono in genere abbastanza sottili (10-15 cm di larghezza) e si estendono per 30-50 cm al di sotto della tavola del permafrost; anche in questo caso sono presenti nello strato attivo sovrastante cunei di ghiaia e sabbia (fig. 3). 55.. ddiissccuussssiioonnee dalle osservazioni fatte appare chiaro come la maggior parte dei poligoni presenti nel territorio delle northern foothills sia soggetto a processi di fessurazione tuttora attivi ma che l’accrescimento dei cunei sia alquanto limitato come testimoniato dall’eseguità dei “rampart” laterali (20-30 cm di altezza) e dalle ridotte dimensioni dei cunei stessi (1 m al massimo di profondità e larghezza). tali dimensioni sono nettamente inferiori a quelle medie note in artico (6-10 m di profondità e 2-3 m di larghezza). bisogna inoltre sottolineare come gli unici e modesti cunei di ghiaccio rinvenuti presso m. browning non esprimano morfologicamente veri e propri poligoni e siano circoscritti al di sopra di till più antichi suggerendo così condizioni genetiche relativamente più m. guglielmin, h.m. french & f. dramis fig. 3 cuneo di ghiaccio ritrovato all'interno del older drift a m. browning. si noti la forte alterazione del suolo nella parte inferiore della trincea. ice wedge found in older drift at mt. browning. note the high grade of soil alteration in the lower part of the trench. 155 umide di quelle attuali. i poligoni osservati sono per la maggior parte attivi, con cunei costituiti da sabbia e ghiaia, e si rinvengono in tutti i tipi di terreno (specialmente nei drift più recenti e nei depositi di spiaggia). essi sono a luoghi contraddistinti da profili convessi e da ramparts laterali poco accentuati che non sembrano riflettere un processo di “upthrusting” quanto piuttosto una forma di accumulo connessa con l’espansione termica dello strato attivo (mackay, 1980). questo processo di espansione e il relativo movimento laterale del materiale secondo direttrici radiali rispetto al centro del poligono si producono quando esistono rilevanti variazioni termiche nel terreno (anche rimanendo al di sotto di 0 °c). tale fatto è dimostrato dai dati rilevati nella stazione di boulder clay dove si registrano temperature del suolo anche di 10 °c maggiori di quelle dell’aria e variazioni termiche anche superiori all’interno della medesima giornata. per quantificare l’entità del movimento in gioco basta ricordare che mackay (1980) nella regione del mackenzie delta in canada ha misurato movimenti di circa 0.25 cm/anno: considerando che la temperatura dell’aria e del suolo sono certamente più basse nell’area in esame, si può ragionevolmente ritenere che l’entità del movimento sia qui sensibilmente inferiore. in generale appare chiaro che, sotto l’aspetto tipologico, i poligoni osservati non sono riferibili a cunei di ghiaccio ma non risultano neppure riferibili ai tipici cunei di sabbia (sand wedges) quali quelli descritti da carter (1983) e murton & french (1993) nell’artico nordamericano. infatti il riempimento delle fessure non risulta mai costituito dalla sola frazione sabbiosa ma in prevalenza da ghiaie con sabbia e ciottoli in cui si è avuto certamente un arricchimento di sabbia per trasporto eolico. terminologicamente si preferisce però non utilizzare il termine proposto da péwé (1959) “tesselations” (mosaici) in quanto non esprime chiaramente né i processi morfogenetici né le caratteristiche sedimentologiche dei cunei e si propone quindi di utilizzare il termine “poligoni di fessure da gelo” (frost fissure polygons) per enfatizzare soprattutto il processo che genera la fessurazione e non la tipologia del riempimento. bisogna inoltre sottolineare come i piccoli cunei di ghiaccio ritrovati nell’older drift del m. browning sono i primi realmente documentati in antartide in quanto né nei lavori di black né in quelli di péwé è possibile vedere sezioni riferibili a questa tipologia. si vuole sottolineare infine che i poligoni di fessure da gelo sono forme tipicamente connesse al permafrost indipendentemente dalla tipologia del substrato e quindi non attribuibili ad altri processi connessi con la dinamica glaciale. data la discontinuità nel tempo del processo di fessurazione, tali poligoni non possono essere utilizzati per la datazione relativa dei terreni su cui sono sviluppati, ma il loro monitoraggio risulta di grande interesse in quanto connesso con le variazioni di bilancio energetico della superficie e quindi con le variazioni climatiche. 66.. ccoonnii ddii iinniieezziioonnee nell’area in esame sono stati da tempo stati riconosciuti numerosi accumuli detritici di forma conica a base circolare o ellittica, di altezza compresa tra i 2 e 4 m (eccezionalmente fino ai 8-10 m), costituiti per lo più da ghiaia, ciottoli e blocchi con scarsa matrice in superficie e talora contraddistinti (nella parte più superficiale) dalla presenza di mirabilite (chinn et al., 1989). molti degli accumuli sono ubicati in prossimità o nel mezzo di laghi perennemente congelati (fig. 4). questi elementi morfologici sono stati considerati in letteratura come forme di ablazione differenziale associate a ghiacciai ricoperti o a ghiaccio morto (chinn et al., 1989; orombelli et al., 1991; lozej et al., 1992). quattro accumuli conici sono stati analizzati nella zona di boulder clay glacier, attorno alla stazione di monitoraggio del permafrost: due ad enigma lake, uno sull’amorphous glacier e uno a tarn flat. caratteristica comune a tutti i coni osservati in prossimità o in corrispondenza di laghi gelati è la minore alterazione superficiale del deposito rispetto al drift circostante. tale differenza di alterazione è particolarmente evidente nel caso di amorphous glacier e tarn flat. proprio nel caso di tarn flat (fig. 5) è possibile osservare come il fondale dei laghi completamente drenati appaia meno alterato degli affioramenti circostanti analogamente a quanto avviene per la superficie del cono. sulle superfici gelate dei laghi di boulder clay, enigma lake ed inexpressible island sono state osservate anche forme di doming sempre accompagnate da fessurazioni radiali. tali fenopermafrost e forme periglaciali ... fig. 4 cono di iniezione all'interno del lago localizzato presso la stazione di boulder clay glacier. si noti anche il doming del ghiaccio lacustre. the frost-heaved mounds of the pond near the boulder clay glacier station. note the doming of the ice surface of the lake. 156 meni sono del tutto simili a quelle riscontrate nei blister da ghiacciamento superficiale (icing blisters) in molte località del artico canadese e che si formano nella stagione invernale e primaverile. si ricordano, a titolo esemplificativo, gli esempi di churchill, manitoba nel maggio 1981 (french & gilbert, 1982), dello yukon centrale nel marzo 1982 (pollard & french, 1984) e della parte centrale dell’isola di banks nell’aprile 1979 (french, 1996). 77.. iill ccaassoo ddii eenniiggmmaa llaakkee enigma lake è stato oggetto di numerose e dettagliate indagini geofisiche (lozej et al., 1992; 1994) e di indagini geomorfologiche e glaciologiche (chinn et al., 1989; lozej et al., 1992) in quanto presenta la peculiarità di avere nella sua parte centrale una sottile copertura glaciale e due coni detritici, dei quali il maggiore raggiunge i 5 m di altezza ed il minore di circa 2 m. chinn et al., (1989) hanno ipotizzato che tale forma rappresenti la parte visibile di un corpo glaciale risalente al ross sea drift e presente nella depressione prima della formazione del lago. del tutto simile è la spiegazione di lozej et al. (1992) secondo i quali il ghiaccio lacustre avrebbe circondato e in parte sepolto un corpo glaciale relitto. dalle osservazioni effettuate durante il mese di novembre 1998 è stato tuttavia possibile osservare come siano presenti non solo alcune zone di doming con numerose fratture radiali ma anche una rilevante quantità di acqua liquida in superficie ed in tasche al di sotto della superficie. e’ stata inoltre rilevata la presenza di ghiaccio di rigelo, di tipo non colonnare, intruso all’interno del ghiaccio lacustre circostante a dimostrazione dell’esistenza di processi di iniezione idrostatica. in questo contesto appare utile ricordare che gli stessi autori hanno già rilevato l’esistenza di un emissario verso la tethys bay e che la presenza di acqua superficiale e di variazioni areali del bacino lacustre sono documentate anche dall’analisi di fotografie aeree dalle quali r isulta circa i l 5% di aumento di area nella porzione settentrionale nel 1985 rispetto al 1956 (orombelli, 1990). alla luce di queste evidenze è possibile rielaborare i dati prodotti nel corso degli anni dagli autori precedenti seguendo una diversa ipotesi genetica. utili risultano in particolare le analisi del contenuto in trizio riportate in chinn et al. (1989) che evidenziano la presenza a circa 3 m di profondità di un orizzonte riferibi le al periodo postnucleare (1954-1963) interposto tra ghiaccio prenucleare con un valore isotopico di 23 t.u. la presenza di un valore così elevato significa senza dubbio che acqua recente si è intrusa in ghiaccio più antico e che questa si è congelata durante la stagione invernale (mantenendo così un valore isotopico più basso di quello attuale). per tutte le considerazioni sopra esposte si ritiene più semplice spiegare la formazione dei coni detritici come prodotti del medesimo processo che genera il doming nei laghi. la formazione di ghiaccio di iniezione generato dalla presenza di acqua allo stato liquido, congelando nei mesi invernali, può esercitare una pressione idrostatica tale sia da creare il doming, che da rialzare il letto del lago (sul quale è presente uno strato di sedimenti dello spessore di 30-50 cm), dando così origine ai coni detritici stessi. nelle zone artiche, forme analoghe vengono distinte in perenni (come i pingo) e stagionali, note in generale come “seasonal frost mounds” (porsild, 1938; mackay, 1979), entrambe connesse con il processo di iniezione di ghiaccio generato dal rigelo di acque sotterranee circolanti. talvolta però le forme perenni mostrano sui fianchi la formazione di forme stagionali (porsild, 1938) come, per altro verso, alcune forme stagionali (blister da ghiacciamento) possono riprodursi per diversi anni nel medesimo sito (van everdingen, 1978; pollard & french, 1985). si ritiene che nel caso delle forme individuate nelle northern foothills si tratti di forme originate stagionalmente ma di durata perenne dal momento che non vengano smantellate con il disgelo durante la stagione estiva. di rilevante interesse paleoclimatico ed ambientale sarebbe capire se questi episodi di crescita stagionali siano continui oppure discontinui e corrispondenti a stagioni estive particolarmente od eccezionalmente calde tali da generare la quantità di acqua circolante necessam. guglielmin, h.m. french & f. dramis fig. 5 il cono di iniezione di tarn flat. si noti la differenza di alterazione tra il materiale costituente il cono e la circostante copertura detritica. the frost-heaved mound of tarn flat. note the different weathering of the rocks that composed the mounds and the surrounding debris cover. ria all’iniezione del ghiaccio durante il successivo inverno. proprio per questo motivo come indicato da overpeck et al. (1998) si potrebbe utilizzare il monitoraggio di queste forme per evidenziare eventuali cambiamenti climatici globali. rriinnggrraazziiaammeennttii la presente ricerca è stata svolta all’interno del progetto 2a.1.3. del prna (progetto nazionale di ricerca in antartide). si ringraziano i responsabili dell’organizzazione e della logistica della base italiana di baia terra nova ed i pi loti della new zealand helicopters. un particolare ringraziamento a luigi bonetti per l’aiuto sostanziale nella realizzazione delle sezioni criostratigrafiche e delle perforazioni. bbiibblliiooggrraaffiiaa baroni c., 1996 antarctic geomorphological and glaciological 1:250,000 map series. mount melbourne quadrangle (victoria land). pnra. museo nazionale dell’antartide siena, italy. black r.f., 1973 growth of patterned ground in victoria land, antarctica. in: permafrost; north american contribution, second int. permafrost conf., yakutsk, ussr, washington d.c., national academy of science, publ. 2115, 193-203. black r.f. & berg t.e., 1966 patterned ground in antarctica. proceed. first int. permafrost conf., national academy of sciences, national research council of canada, publ. 1287, 121-127. bondesan a., meneghel m., salvatore m.c. & stenni b., 1997 non sorted polygons in the terra nova bay area (victoria land). in: antarctic region: geological evolution and processes, ricci c.a. ed., terra antartica publ., siena, 957-963. carter l.d., 1983 fossil sand wedges on the alaskan arctic coastal plain and their palaeoenvironmental significance. proceed. fourth int. permafrost conf., national academy press, washington d.c., 109-114. chinn t.j., whitehouse i.e. & hofle h.c., 1989 report on a reconnaissance of the glaciers of terranova bay area. geol. jb., ser. e, 3388, 299-319. french h.m., 1996 the periglacial environment, 2nd ed. longman ltd., 341 pp. french h.m. & gilbert r., 1982 periglacial phenomena near churchill, manitoba. can. nat., 110099, 433-444. guglielmin m. & dramis f., 1998 permafrost as a climatic indicator in northern victoria land (antarctica). proceed. seventh int. permafrost conf., yellowknife, n.w.t., canada, vol. 1, 147148. lozej a., tabacco i., meneghel m., orombelli g., smiraglia c. & longinelli a., 1992 radio-echo soundings of enigma lake (northern foothills, victoria land, antarctica). mem. soc. geol. it., 4466, 103-115. mackay j.r., 1979 an equilibrium model for hummocks (non-sorted circles), garry island, northwest territories. geological survey of canada, paper 79-1 a, 165-167. mackay j.r., 1980 the origin of hummocks, western arctic coast. can. j. earth sci., 1177, 996-1006. müller f., 1959 beobachtung uber pingos. meddelelser om gronland, 115533 (3), 127 pp. murton j.b. & french h.m., 1993 sand wedges and permafrost history, crumbling point, pleistocene mackenzie delta, canada. proceed. sixth int. permafrost conf., vol. 1, beijing science press, 482-487. orombelli g., 1990 glaciers and glacial morphology at terra nova bay: an opportunity for significant studies on environmental and climatic global changes. mem. soc. geol. it., 4466, 9-16. orombelli g., baroni c. & denton g.h., 1991 late cenozoic glacial history of the terra nova bay region, northern victoria land, antarctica. geogr. fis. dinam. quat., 1133, 139-163. overpeck j., hughen k., hardy d., bradley r., case r., douglas m., finney b., gajewski k., facoby g., jennings a., lamoureaux s., lasca a., macdonald g., moore j., retelle m., smith s., wolfe a. & zielinski g., 1997 arctic environmental change of the last four centuries. science, 227788, 1251-1256. péwé t.l., 1959 sand wedge polygons (tesselations) in the mcmurdo sound region, antarctica. am. j. sci., 225577, 545-552. piccardi g., udisti r. & casella f., 1994 seasonal trends and chemical composition of snow at terra nova bay (antarctica). int. j. envir. anal. chem., 5555, 219-234. pollard w.h. & french h.m., 1984 the groundwater hydraulics of seasonal frost mounds, northern yukon. can. j. earth sci., 2211, 1073-1081. pollard w.h. & french h.m., 1985 the internal structure and ice crystallography of seasonal frost mounds. j. glaciol., 3311, 157-162. porsild a.e., 1938 earth mounds in unglaciated arctic northwestern america. geogr. rev., 2288, 46-58. van everdingen r.o., 1978 frost mounds at bear rock near fort norman, n.w.t. 1975-1976. can. j. earth sci., 1155,, 263-276. 157permafrost e forme periglaciali ... ms. ricevuto il 21 agosto 2002 testo definitivo ricevuto il 28 gennaio 2003 ms. received: august 21, 2002 final text received: january 28, 2003 amq abs divito et al tepro 205-208.pub available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 205 208 the vesuvius pomici di avellino plinian eruption and related phenomena: effects on the bronze age landscape of campania region (southern italy) mauro antonio di vito1, pierfrancesco talamo 2, ilaria rucco 1, halinka di lorenzo 3 1 istituto nazionale di geofisica e vulcanologia, sezione di napoli osservatorio vesuviano, napoli, italy 2 parco archeologico dei campi flegrei, mibact, napoli, italy 3 distar, università degli studi di napoli, italy corresponding author: m.a. di vito <mauro.divito@ingv.it> abstract: the vesuvian pomici di avellino eruption affected an area densely inhabited by early bronze age human communities and resulted in the long term abandonment of an extensive zone surrounding the volcano. the study of geological and archaeological sequences have yielded an understanding of the eruption local effects and of their duration. the territory was rapidly abandoned during the eruption. only few settlements were found of phases 1 and 2 of the middle bronze age in most of the area affected by the eruption. we interpret this as due to diffuse phenomena of remobilization of the erupted pyroclastics, generating long lasting alluvial processes. a significant resettlement of the territory occurred only hundreds of years after the eruption, during phase 3 of the middle bronze age. keywords: plinian eruption, volcanoclastic mass flow, vesuvius, bronze age, eruption impact 1. introduction plinian eruptions are among the most dangerous natural phenomena for human life and the environment, characterized by very energetic and sustained explosive phases generating convective plumes and whose instability and collapse can generate pyroclastic density currents. they also produce secondary phenomena, not directly connected to the eruption itself, like, volcaniclastic mass flows (lahars) generated by the remobilization of pyroclastic deposits that can occur in areas very far from the vent and even centuries after an eruption. the pomici di avellino eruption (hereafter pda, 3,945 ± 10 cal yr bp) is one of the four plinian eruptions of vesuvius, considered one of the most explosive holocene events in the mediterranean area. the eruption and related phenomena affected a wide and densely inhabited area in the early bronze age (hereafter eba) (di vito et al., 2018 and references therein). in this paper we present the results of volcanological and archaeological investigations concerning the impact of the pda eruption and related volcanoclastic mass flows, in order to reconstruct the human abandonment and resettlement dynamics of the campania region, during the early and middle bronze age. 2. material and methods combined volcanological and archaeological studies has permitted to understand the relationship between human settlements and natural hazards (di vito et al., 2009; di lorenzo et al., 2013; de vita et al., 2013; romano et al., 2013; vingiani et al., 2017; di vito et al., 2018). the integration of volcanological and archaeological data from literature and the analysis of sequences in recent excavations permitted the creation of a dataset with information on more than 300 sites in the campanian plain and in the surrounding apennine valleys. particular attention has been payed to the emplacement mechanisms of volcanic and volcanoclastic deposits, in order to analyse the effects of the eruption and of the secondary environmental processes on the palma campania culture settlements pre-existing to the pda eruption. the integration of stratigraphic and archaeologic investigations also permitted to evaluate the time of reoccupation of the teritory. 3. results the campanian plain, and especially the lowlands surrounding vesuvius, was densely inhabited by communities of farmers and pastoralists belonging to the eba palma campania culture. all of the most important remains of this culture have come from the numerous villages buried by variable deposits of the pda eruption (fig. 1). some of these settlements were of considerable extent. in some places there are evidence of attempts of resettlement soon after eruption (green dots in fig. 1). the pda eruption occurred during the eba and in particular between the end of the twentieth and the beginning of the nineteenth century bc (passariello et al., 2009, 2010; sevink et al., 2011). according to di vito et al. (2009), the eruption can be divided into five eruption units (eus) emplaced during three phases: opening, plinian and phreatomagmatic. the opening phase was characterized by a low eruption column that emplaced thin ash layers (eu1) distributed toward the east of the vent; the plinian phase generated a 23-to-31 km high eruption column, that emplaced widely distributed pumice fallouts deposits (eu2, https://doi.org/10.26382/aiqua.2018.aiquaconference eu3 and eu4 – fig. 1), and ended with a caldera collapse. the last phreatomagmatic phase was dominated by pulsating phreatomagmatic explosions that produced both pyroclastic density currents and minor fallout deposits (eu5 – fig. 1). these deposits can be divided in four subunits (eu5a-d), that correspond to at least four explosive episodes, separated by short pauses during the eruption. human and animal footprints and hoofprints have been found at different heights in eu5 unit and testify to some migration episodes during the final phases of the eruption (di vito et al., 2009). the eruption caused also a general hydrogeological destabilization of the territory, which generated lahars, debris flows and alluvial processes in a wide area. in archaeological excavations and in natural exposures, the presence of soils or unconformities between the primary and secondary deposits, or within the secondary deposit has been used to distinguish among syneruptive (according to the definition of sulpizio et al., 2006) and intereruptive lahars, debris flows and alluvial deposits. in fig. 2 we report only the sites containing syneruptive debris flow deposits. they are composed almost exclusively of fragments from pda eruption. 4. discussion and conclusions the analysis carried out in an area of about 3.000 km2 and on at least 300 investigated sites shows that before the pda eruption campanian plain was more or less occupied by palma campania facies settlements. the first effect of the eruption is that the following facies, that is the proto apennine facies (middle bronze age 1 and 2), is almost completely missing in the area, covered by primary and secondary deposits; instead there are evidence of a continuity of human presence, with the two archaeological facies, in few sites far from the areas interested by the main deposition of the pda primary and secondary products (fig. 2) or along the coastal area of the gulf of naples, where an increase in the settled sites is seen. therefore, from the period immediately following the pda eruption and for at least a couple of centuries, the population declined in almost the entire area affected by the eruption and related phenomena. this seems to have occurred regardless of the distance from the vent and the local impact of the eruption phenomena on the environment and human settlements. this population decline might have also been caused by adverse 206 fig. 1 early bronze age settlements. red dots indicate the sites existing before the pomici di avellino eruption; green dots indicate those sites in which there are also evidences of attempts of resettlement soon after the eruption. the total distribution of the pomici di avellino deposits is reported for reference: pdc deposits in purple; fallout deposits in white. in the inset the total distribution of the pomici di avellino deposits. (modified after di vito et al., 2018). di vito m.a. et al. 207 climatic conditions, which soon after the eruption increased the area's hydrogeological instability, with generation of huge, frequent and widely distributed lahars (fig. 2, see distribution of grey diamonds). this period was followed by a climate deterioration that would not have favored agriculture in the zone (zanchetta et al., submitted). furthermore, all along the coastal area, even though the crisis triggered deep changes, it did not lead to a total de-structuring of the territory and, after a short period, a new equilibrium seems to have been reached. a significant resettlement of the territory occurred only hundreds of years after the pda eruption, during phase 3 of the middle bronze age (apennine facies), during a period of favourable environmental conditions. acknowledgments the presented study has benefited from the financial support of the presidenza del consiglio dei ministri dipartimento della protezione civile dpc-ingv project ob. 4 task 1. the authors are grateful to the archaeological superintendences of campania for allowing the analyses of sequences in excavations. references de vita s., di vito m.a., gialanella c., sansivero f. (2013) the impact of the ischia porto tephra eruption (italy) on the greek colony of pthekoussai. quaternary international, 303, 142-152. di lorenzo h., di vito m.a., talamo p., bishop j., castaldo n., de vita s., nave r., pacciarelli m. (2013) the impact of the pomici di avellino plinian eruption of vesuvius on early and middle bronze age human settlement in campania (southern italy). tagungen des landesmuseums für vorgeschichte halle, 9, 253-265. di vito m.a., talamo p., de vita s., rucco i., zanchetta g., cesarano m. (2018) dynamics and effects of the vesuvius pomici di avellino plinian eruption and related phenomena on the bronze age landscape of campania region (southern italy). quaternary international. doi: 10.1016/j.quaint.2018.03.021 di vito m.a., zanella e., gurioli l., lanza r., sulpizio r., bishop j., tema e., boenzi g., laforgia e. (2009) the afragola settlement near vesuvius, fig. 2 location of the middle bronze age 1, 2 (protoapennine 1 and 2 facies, blue dots) and 3 sites (apennine facies, red dots). the total distribution of the pomici di avellino deposits is reported for reference, as in fig 1. grey diamonds indicate the sites at which the syneruptive volcanoclastic mass flow deposits have been recognized. the total distribution of the pomici di avellino deposits is reported for reference, as in fig.1 (modified after di vito et al., 2018) effects of the human settlements of the pomici di avellino eruption italy: the destruction and abandonment of a bronze age village revealed by archaeology, volcanology and rock-magnetism. earth and planetary science letters, 277, 408-421. passariello i., albore livadie c., talamo p., lubritto c., d'onofrio a., terrasi f. (2009) 14c chronology of avellino pumices eruption and timing of human reoccupation of the devastated region. radiocarbon, 51 (02), 803-816. passariello i., lubritto c., d'onofrio a., guan y., terrasi f. (2010) the somma-vesuvius complex and the phlaegrean fields caldera: new chronological data of several eruptions of the copper-middle bronze age period. nuclear instruments and methods in physics research b, 268, 1008-1012. romano p., di vito m.a., giampaola d., cinque a., bartoli c., boenzi g., detta f., di marco m., giglio m., iodice s., liuzza v., ruello m.r., schiano di cola c. (2013) intersection of exogenous, endogenous and anthropogenic factors in the holocene landscape: a study of the naples coastline during the last 6000 years. quaternary international, 303, 107-119. sevink j., van bergen m.j., van der plicht j., feiken h., anastasia c., huizinga h. (2011) robust date for the bronze age avellino eruption (sommavesuvius): 3945 ±10 calbp (1995 ±10 calbc). quaternary science review, 30 (9), 1035-1046. sulpizio r., zanchetta g., demi f., di vito m.a., pareschi m.t., santacroce r. (2006) the holocene syneruptive volcaniclastic debris flows in the vesuvian area: geological data as a guide for hazard assessment. in: siebe, c., macias, j.l., aguirre-diaz, g.j. (eds.). neogene-quaternary continental margin volcanism: a perspective from mexico, special paper, gsa, 402, 203-221. vingiani s., minieri l., albore livadie c., di vito m.a., terribile f. (2017) pedological investigation of an early bronze age site in southern italy. geoarchaeology, 33, 193-217. zanchetta g., bini m., di vito m.a., sulpizio r., sadori l. (submitted) tephrostratigraphy and synchronization of climatic archives in the central mediterranean during the bronze age. quaternary international. 208 di vito m.a. et al. ms. received: may 7, 2018 final text received: may 21, 2018 imp.bertacchini in search of “underground urban geosites”. the city of modena “upside-down” milena bertacchini department of earth sciences, university of modena and reggio emilia (italy), l.go s. eufemia, 19, 41100 modena (italy); email: bertacchini.milena@unimore.it abstract: m. bertacchini, in search of “underground urban geosites”. the city of modena “upside-down” . (it issn 0394-3356, 2005). a rich cultural heritage is hidden in the subsoil of many italian cities. this underground heritage could tell the story and the evolution of the urban environment through the traces of natural and anthropogenetic components which shaped it in space and time and are now interwoven in the physical landscape that surrounds it. underground urban geosites are the historical and territorial memory of this evolution since they are the buried traces of urban environment components. the aim of the “sottosopra” (upside-down) project is to appraise the cultural heritage buried beneath the city of modena. there is a network of cultural itineraries following the underground town’s canals, inviting visitors to discover and enjoy all the underground urban geosites which have stratified in the subsoil of modena during nearly two thousand years of history. abstract: m. bertacchini, alla ricerca di “geositi sotterranei urbani”. la città di modena “sottosopra” . (it issn 0394-3356, 2005). un ricco patrimonio culturale è nascosto nel sottosuolo di molte città italiane. questo patrimonio sotterraneo è in grado di raccontare la storia e l’evoluzione del paesaggio urbano attraverso le tracce delle componenti naturali e antropiche che lo hanno plasmato nello spazio e nel tempo e che ora sono intessute nel paesaggio fisico che le circonda. i geositi sotterranei urbani rappresentano la memoria storica e territoriale di questa evoluzione, in quanto tracce sepolte delle componenti il paesaggio urbano. il progetto “sottosopra” intende valorizzare il patrimonio culturale sepolto sotto la città di modena grazie ad una rete di itinerari culturali che virtualmente seguono i canali sotterranei cittadini e invitano i visitatori alla conoscenza e alla fruizione di tutti quei geositi sotterranei urbani che si sono andati stratificando nel sottosuolo modenese nel corso di quasi duemila anni di storia. keywords: cultural landscape, natural components, anthropogenetic components, underground urban geosites, appraisal, fruition. parole chiave: paesaggio culturale, componenti naturali, componenti antropiche, geositi sotterranei urbani, valorizzazione, fruizione. il quaternario italian journal of quaternary sciences 18(1), 2005 volume speciale, 163-166 1. foreword the italian landscape – one of the most important components of national cultural heritage (panizza & piacente, 2003) – is an amazing assemblage of nature and history, formed by both natural and human elements which intertwine, condition each other and eventually settle by interacting with the pre-existing environment, albeit in diverse ways and with varying intensity. historical phenomena and human vicissitudes tend to shape the landscape at ground level, whereas natural components – particularly geological components – can affect its evolution through various and sometimes remarkable processes, even involving large rock masses at considerable depths. the memory of past geological events which influenced the landscape’s evolution is preserved in the form of either visible traces above the earth’s surface or as hidden remains buried in the subsoil. therefore, geosites represent the territorial memory of these geological processes. among the various types of geosites found above or below sea level, those located in the subsoil include both geological, geomorphological, pedological etc. elements which are at present below the line of the horizon and many underground cavities which are the object of speleological exploration and research. 2. geosites in the urban context numerous italian, european and non-european cities preserve a rich hidden world in their subsoil; an underground world comprising “unusual, buried environments constructed by man through the centuries” (ardito, 2003) interwoven with the physical landscape that surrounds them. houses, aqueducts, bridges, river quays, streets, necropoles, baths, mosaics, old pavements etc., they all are real buried monuments witnessing the history, life and culture in general of old towns (bertacchini et al., 2001; 2002). all these elements combine and merge with the natural elements of the underground landscape they belong to. together with abandoned river courses, paleosoils, sedimentary sequences etc., they make up considerable “geo-archaeological” complexes, since they are the embodiment of geological, archaeological, historical, artistic and socioeconomic information. the strong and ever-growing public interest in the rediscovery of scientific, historical, tourist and cultural aspects that characterise many italian urban centres, has recently aroused also the interest of the massmedia (fig. 1). the term “urban speleology” has now become commonplace, indicating the discipline which studies caves, tunnels, narrow passages and underground shafts buried under the towns. in order to main164 m. bertacchini tain a connection with the terminology already in use and by analogy with the definition of underground geosites, the natural and anthropogenetic components of the urban landscape which are hidden in the subsoil will be defined as “underground urban geosites”. 3. the “sottosopra” project the city of modena is built on top of the remains of “mutina”, a roman colony whose urban development was strongly influenced and conditioned by the morphological evolution of water courses which in ancient t imes flowed near or even through it (bertacchini, 2003a). geosites are the testimony of this evolution. in order to promote awareness and information regarding the cultural heritage of the city of modena and, in particular, of its buried heritage, the “sottosopra” (upside-down) project has been planned and implemented. this is a virtual cultural pathway which was presented in modena at “the invisible town” congress, during the international day for the environment (bertacchini, 2003b). this project is now fig. 1 – excerpt from an article published on 30th may 2003 in “il venerdì”, supplement of the italian paper “la repubblica”, concerning a new form of urban tourism: “underground tourism”. stralcio di un articolo comparso il 30 maggio 2003 nell’inserto “il venerdì” del quotidiano “la repubblica”, relativo ad una nuova forma di turismo urbano: il “turismo underground”. fig. 2 – “sottosopra” is a virtual cultural pathway composed of a series of interlinked itineraries that wind through the city of modena, following the courses of underground canals. in this initial phase of the project, four itineraries coinciding with the city’s main canals have been identified: 1. naviglio; 2. canal grande; 3. canal chiaro; 4. modenella. the figure shows the areas considered by each itinerary (modified after bertacchini, 2003). “sottosopra” è un percorso culturale e virtuale composto di una serie di itinerari tra loro dialoganti, che si snodano all’interno della città di modena seguendo la traccia dei canali sotterranei. in questa fase iniziale del progetto, sono stati individuati quattro itinerari coincidenti con i principali canali della città: 1. naviglio; 2. canal grande; 3. canal chiaro; 4. modenella. in figura sono visualizzate le aree considerate da ciascun itinerario (modif. da bertacchini, 2003). taking shape, thanks to the collaboration between the department of earth sciences of modena and reggio emilia university and the environmental office of the municipality of modena (bertacchini et al., 2003). it is particularly suitable for spreading basic information about the city’s physical territory and its historical, architectural, artistic, etc. components by means of their appraisal and more immediate fruition. “sottosopra” reconstructs the story that the underground urban landscape can tell us by means of the natural and anthropogenetic remains which have shaped it in time and space (piacente, 1999). in particular, “sottosopra” underlines the presence and evolution of a dense network of natural water courses, springs and artificial canals which have always characterised the territory of modena. these waterways have always controlled and sometimes constrained the development of this city, leaving traces in the urban geosites hidden in the subsoil. for about two thousand years, the action of these waterways was so intense as to cause the accumulation of thick sedimentary sequences, which contributed to hiding and obliterating the remains of roman mutina and the subsequent early medieval and late medieval town, right up to relatively recent times. confirmation of this can be found in lugli et al. (2002) which records that paleosoil from the roman era is found at depths of 2.5 to 11 m below the present ground level in the historical town-centre of modena. in order to learn more about the history of the city of modena and its territory, visitors are invited to follow the path of its underground waterways, discovering and observing selected urban geosites, most of which have contributed to modifying the urban landscape over the years. this is the case of old pavements, streets, houses, mosaics, river quays and city gates, as well as sedimentary sequences rich in remains of daily life, witnessing past environmental conditions and paleosoils with plant remains which point to climatic conditions different from the present ones. from a practical viewpoint, the territory of modena has been subdivided into a series of itineraries (fig. 2) connected to each other. they wind through the underground courses of the main canals that still flow beneath the city centre today: the naviglio (itinerary 1), the canal grande or canale di san pietro (itinerary 2), the canal chiaro ( it inerary 3) and the modenella ( it inerary 4) (bertacchini et al., 2003). a series of sensitive elements, graphically differentiated according to the types of urban geosites identif ied (fig. 3), marks each urban asset found along each itinerary and interactively directs users to specific, detailed descriptions (fig. 4a, b): old pictures, recent photographs, films, reproductions of works of art and archaeological f inds related to a specific geosite and/or to other components of the urban landscape. 165in search of “underground ...” fig. 3 – legend of some sensitive multimedia connection elements between the different forms of detailed description contained in the “sottosopra” project. legenda di alcuni elementi sensibili di collegamento multimediale tra le diverse forme di approfondimento contenute in “sottosopra”. fig. 4 – two examples of specific descriptions found in the virtual pathway. background colours of boxes indicate: a) black = underground urban geosites; b) grey = urban geosites still linked to visible elements appearing at street level (modified after bertacchini et al., 2003). due esempi di schede di approfondimento tra quelle presenti all’interno del percorso virtuale. il diverso colore di fondo delle schede differenzia: a) nero: i geositi sotterranei urbani; b) grigio: i geositi urbani ancora legati ad elementi visibili “sopra” la città (modif. da bertacchini et al. 2003). 166 visitors can navigate through this multi-media hypertext from their computer desks and discover the cultural heritage hidden beneath the city of modena contained in the underground urban geosites that have progressively stratified during nearly two thousand years of history. the continuous possibility to update and implement the project with new data and detailed information makes the “sottosopra” project a multi-medial tool that can be adapted to changing needs and interests (bertacchini et al., 2001; 2002) and that can grow alongside the city and its cultural heritage. references ardito f. (2003) italia sotterranea de agostini ed., 256 pp. bertacchini m. (2003a) la città “sottosopra”: evoluzione geologica recente atti del conv. “la città che non si vede”, abstract, 5 giugno 2003, comune di modena. bertacchini m. (2003b) “sottosopra”: un percorso culturale-virtuale nella città di modena atti del conv. “la città che non si vede”, 5 giugno 2003, comune di modena, 14 pp. bertacchini m., coratza p. & piacente s. (2001) le “pietre del diavolo” tra borghi e castell i nell’appennino emiliano. un percorso culturale e didattico nel paesaggio ofiolitico atti del conv. naz. “le ofioliti: isole sulla terraferma”, 22-23 giugno 2001, riserva naturale monte prinzera, parma, pp. 239-250. bertacchini m., coratza p. & piacente s. (2002) paesaggi culturali. geologia e letteratura nel novecento in emilia-romagna univ. di modena e reggio e., dip. sc. terra, regione emiliaromagna, servizio valorizzazione e tutela del paesaggio. ed. l’inchiostroblù, bologna, 138 pp. bertacchini m., fontana d. & paltrinieri n. (2003) modena si svela alla rete in: “noi & l’ambiente”, modena, pp. 44-46. lugli s., fontana d., giordani n., labate d. & sacco d. (2002) stratigrafia e composizione dei sedimenti sabbiosi del sottosuolo di modena: implicazioni nell’alluvionamento della città romana. risultati preliminari atti del ii congr. naz. di archeometria, bologna, 29 gennaio-1 febbraio 2002, a.i.ar., pàtron ed., bologna, pp. 341-351. panizza m. & piacente s. (2003) geomorfologia culturale pitagora editrice bologna, 350 pp. piacente s. (1999) la conoscenza scientifica, un valore aggiunto in: g. poli (ed.), geositi, testimoni del tempo, regione emilia-romagna, bologna, pp. 234-244. m. bertacchini imp.bedulli& struttura fisica della conoide alluvionale gigante del fiume taro e ricarica degli acquiferi della pianura parmense franco bedulli & renzo valloni dipartimento di scienze della terra, università di parma parco area delle scienze 157a, 43100 parma bedulli@nemo.unipr.it, valloni@unipr.it riassunto: bedulli f. & valloni r., struttura fisica della conoide alluvionale gigante del fiume taro e ricarica degli acquiferi della pianura parmense. (it issn 0394-3356, 2004). i nuovi dati geognostici e stratigrafici di dettaglio raccolti negli ultimi anni hanno consentito di realizzare numerose sezioni geologiche atte a definire la struttura fisica d’insieme della conoide del fiume taro, il suo scheletro sedimentario e le modalità di ricarica degli acquiferi della pianura di parma. l’apparato di conoide è stato diviso in tre settori a struttura fisica nettamente diversa, detti di valle, margine e pianura, con dimensione assiale rispettivamente di 8, 7 e 15 km. i settori di margine e pianura sono separati dalla struttura positiva sepolta di madregolo che controlla la circolazione sotterranea con una soglia imposta a circa -70 m dal p.c. nel settore di pianura si sviluppa un enorme corpo grossolano di sottosuolo, detto anche conoide gigante, con estensione radiale di 15 km e dimensione trasversale massima di quasi 20 km, che giace su un’estesa barriera di permeabilità con tetto a 180.000 anni fa. il controllo tettonico esercitato dai thrust frontali sepolti della catena è a sua volta modulato dal fattore climatico. le principali unità grossolane del corpo di conoide (interpretate come deposte negli stadiali) e le interposte coperture fini (interpretate come deposte negli interglaciali e interstadiali) sono state attribuite agli stadi isotopici marini 1-6 della letteratura. l’alto strutturale di madregolo influenza grandememente le geometrie deposizionali del sottosuolo. sul suo fronte si produce la progressiva espansione del corpo di conoide. sul suo dorso gli acquiferi risultano saldati fra loro a costituire un grande serbatoio che comunica lungostrato con gli acquiferi in pressione posti più all’esterno. la conoide gigante del fiume taro è compartimentata da tre barriere di permeabilità principali che assumono una relativa continuità solo a valle della via emilia e che sulla verticale dell’autostrada a1 vengono intercettate a -40, -80 e -130 metri dal p.c. abstract: bedulli f. & valloni r., physical structure of the taro river giant alluvial fan and parma plain aquifer recharge. (it issn 0394-3356, 2004). using a large set of stratigraphic data, numerous cross-sections of the southern margin of the parma alluvial plain were drawn; they allowed the recognition of the architecture of the taro alluvial fan and the water flow pattern from the surface to the unconfined and confined aquifers. the middle (medesano-madregolo) and outer portion of the alluvial fan system are separated by an anticline, named madregolo high, which controls the groundflow pattern with its impermeable basement uplifted at about -70 m from ground level. in its outer portion the fan has giant dimensions extending up to 15 km axially and up to 20 km normally to the depositional strike. the sedimentation of the middle-late pleistocene alluvium is strongly related to climatic changes. general and local evidence permit the assignment of the tens of meter thick coarse fluvial deposits to cold (glacial) periods and of the meters thick fine alluvium to warm (interglacial) periods. the base of the alluvial fan rests on a laterally continuous confining layer dated 180.000 yr bp. at the intersection taro river autostrada a1 this layer is encountered at -130 m from ground level; confining layers of lesser importance, internal to the alluvial fan body, are encountered at -40 and -80 m from ground level. in front of the madregolo high the coarse sedimentary units (aquifers) of the alluvial fan body are amalgamated. northwards these aquifers expand in thickness and are put under pressure by the intervening confining layers. this indicates that the groundwater flow pattern is from the front of the madregolo high northwards into the unconfined and confined aquifers of the thickest part of the fan. parole chiave: pleistocene superiore, conoide fiume taro, idrostratigrafia, ricarica acquifero parmense. keywords: late pleistocene, taro alluvial fan, hydrostratigraphy, aquifer recharge. il quaternario italian journal of quaternary sciences 17(2/1), 2004, 303-312 1. introduzione il sottosuolo della pianura emiliana è caratterizzato da una successione di apparati di conoide alluvionale, di varia estensione, con apice allo sbocco in pianura dei principali fiumi (idroser spa, 1977). la conoide del fiume taro è di gran lunga la più estesa del margine emiliano e per questo ha assunto la denominazione di conoide gigante (valloni et al., 2003). la presente ricerca ha preso impulso dai recenti lavori a carattere idrostratigrafico sul sottosuolo padano (rer & eni-agip, 1998; regione lombardia & eniagip, 2002), nei quali le alluvioni quaternarie sono ordinate in unità allostratigrafiche padane e poste in relazione ai ben noti cicli astro-climatici del pleistocene medio-superiore. il quadro parmense di tali unità idrostratigrafiche è analiticamente esposto da di dio (2001). la rappresentatività dell’assetto strutturale della pianura di parma e l’imponente raccolta di dati di son304 f. bedulli & r. valloni daggio acquisita dagli scriventi negli ultimi anni rendono oggi utile e possibile dettagliare lo studio della ricarica degli acquiferi freatici e le loro connessioni con gli acquiferi in pressione della media e bassa pianura. 2. inquadramento geografico la superficie della pianura di parma approssima una monoclinale immergente a nord-nordest con pendenza variabile, ovviamente decrescente verso la bassa pianura. la sua porzione sud presenta, in prima approssimazione, pendenze topografiche maggiori del 4,0 per mille dal margine fino alla via emilia e del 1,5-4,0 per mille dalla via emilia all’autostrada a1 (tellini, 2001). il fiume taro bagna il territorio a ovest della città di parma. il suo bacino imbrifero, pari a 1.368 km2 alla chiusura della via emilia, risulta molto più grande di quello dei vicini torrenti baganza e parma. a fornovo termina il tratto intramontano del corso d’acqua che poi prosegue verso nord, stretto dai rilievi collinari, ancora per diversi km (figura 1). nel tratto successivo non esiste evidenza morfologica di una conoide alluvionale proporzionata al rango del bacino di drenaggio del fiume taro. all’altezza di medesano il fiume scorre con lo stile dei canali intrecciati e con una larghezza dell’alveo attuale superiore al km. all’altezza di noceto il talweg diventa pensile sulla pianura adiacente, un carattere che si accentua verso valle. da noceto fino a valle dell’autostrada a1, in sinistra taro si riconoscono le tracce di antichi percorsi del fiume, mentre in destra taro la superficie della pianura è mediamente più bassa di 5 m (perego, 1994). a partire dall’autostrada a1 il fiume cambia stile iniziando a disegnare meandri (petrucci et al., 1983). 3. studi precedenti, impostazione della ricerca i corpi acquiferi della pianura di parma sono stati investigati con particolare intensità a partire dagli anni settanta del secolo scorso. in generale si tratta di studi che soffrono della mancanza di un quadro stratigrafico regionale ed i principali approfondimenti riguardano primariamente gli aspetti idrologici. venzo (1973) presenta i grandi tratti della struttura fisica della conoide del f. taro distinguendo il settore interno (dall’apice di fornovo alla struttura positiva di madregolo), ove il substrato marino è posto a bassa profondità, dal settore esterno ove il substrato marino si abbassa fortemente verso settentrione (cf. figure 2, 3). sulla base di un vasto corpo di dati di pozzo, petrucci et al. (1975) descrivono la complessità geometrica del substrato marino e l’andamento “irregolare degli acquiferi” che solo nella bassa pianura risultano sicuramente compartimentati (cf. figura 3). in alifraco et al. (1992a) è illustrata la geometria del materasso alluvionale controllata dai “corrugamenti del substrato” che determinano una sinclinale interna ed un’anticlinale sull’allineamento monticelli – fontevivo (cf. figure 2, 3). petrucci et al. (1992) trattano a tutto campo l’idrogeologia della pianura parmense e accertano che la ricarica è dovuta “in via prioritaria alle acque di subalveo” che alimentano le ghiaie dell’alta pianura e che distalmente si connettono ad un “sistema acquifero plurifalda”. in ferrarazzo et al. (1997) sono illustrati i risultati di numerose levate piezometriche ed è determinato il volume dell’acquifero che sormonta il substrato marino, considerato come freatico fino all’altezza della via emilia ove, con il progressivo sviluppo di intercalazioni limoso-argillose, ha inizio lo sviluppo di falde semiconfinate. gli studi a respiro regionale degli ultimi anni consentono di formulare un nuovo quadro concettuale dell’evoluzione sedimentaria della pianura parmense che comprende il riconoscimento di un’unità di colmamento della pianura (cf. figura 3), deposta in età pleistocenica terminale ed olocenica (post glaciale), a litologia essenzialmente fine (severi et al., 2002). la deposizione di tale unità comporta la compensazione topografica della pianura tramite “azioni di aggradazione fluviale” (marchetti, 2001) con la conseguenza che la conoide alluvionale del fiume taro manifesta la sua espressione morfologica solo nel sottosuolo. le fasi di forte trasporto di sedimenti grossolani da parte dei corsi d’acqua appenninici sono registrate fig. 1 inquadramento geografico dell’area di studio e traccia delle sezioni delle figure 3 (collecchio-baganzola), 4 (parola-san prospero) e 5 (fontevivo-casalbaroncolo). geographic setting of the study area and trace of the sections of figures 3, 4 and 5. nella struttura fisica dell’edificio di conoide assieme alle fasi di esteso drappeggio della pianura con depositi fini (interglaciali ed interstadiali) che esprimono gli acquitardi più potenti e continui (amorosi et al., 1996; di dio & valloni, 1997). il presente studio si basa su una moltitudine di dati geognostici e stratigrafici di dettaglio che hanno consentito di realizzare numerose sezioni geologiche ad andamento parallelo e trasversale agli assi deposizionali dei corsi d’acqua appenninici del parmense. in particolare il lavoro persegue i seguenti obiettivi: (1) riconoscimento della struttura fisica d’insieme della conoide del fiume taro, (2) definizione del suo scheletro fisico in termini di acquiferi ed acquitardi principali tramite una maglia di sezioni e (3) illustrazione delle modalità di ricarica degli acquiferi della pianura di parma. 4. ricostruzione fisica del sistema di conoide la base dati stratigrafici su cui si fonda la presente ricerca ha tre articolazioni: (1) la banca dati stratigrafici del dipartimento avviata fin dagli anni settanta dal prof. franco petrucci, (2) i sondaggi stratigrafici eseguiti dalla regione emilia-romagna per l’esecuzione della carta geologica 1:50.000 della pianura emiliana e (3) i sondaggi a carotaggio continuo realizzati dal consorzio linea ferroviaria alta velocità. 305struttura fisica della conoide ... 4.1 struttura fisica lo studio del sottosuolo si spinge fino alla superficie di inconformità che identifica il passaggio fra i depositi continentali ed i sottostanti depositi marini, qui definita basamento idrogeologico in senso lato (figure 2, 3, 4, 5), che nei settori alpino ed appenninico viene datata a 800.000 anni fa (carcano et al., 2002). tale superficie, presentata in figura 2 come immagine 3d con vista all’incirca verso est, mette in risalto la caratteristica struttura positiva del basamento idrogeologico che corre sulla verticale dell’allineamento degli abitati di fontevivo, madregolo, stradella e monticelli terme. il database per la costruzione di questa superficie, che può essere intesa anche come “base del continentale”, deriva dai dati di sondaggio per la porzione interna fino al fronte della struttura positiva e, a partire dall’isolinea -200 verso nord, dalla digitalizzazione della superficie base del continentale in scala 1:250.000 (rer & eni-agip, 1998). la deformazione della superficie in questione è congruente con l’allineamento delle strutture sepolte a thrust dell’appennino emiliano (bernini & papani, 1987) e forma una modesta sinclinale allineata sul fronte della catena (figura 3), qui definita “bacino marginale”, sul cui asse i depositi alluvionali hanno uno spessore dell’ordine dei 100-200 m. la delimitazione fisica d’insieme della conoide tardo-pleistocenica del fiume taro è stata principalmente fatta tramite numerose sezioni geologiche origifig. 2 immagine digitale 3d con vista verso est del tetto del substrato marino (pleistocene medio) nell’area di studio. valori di profondità s.l.m. la superficie azzurra approssima il p.c. e interseca la pedecollina all’appoggio delle alluvioni sul substrato marino affiorante. la struttura positiva posta sull’allineamento monticelli terme madregolo fontevivo identifica al suo interno un bacino marginale in cui la copertura alluvionale ha spessore limitato. 3d representation of the top of the marine deposits of middle pleistocene age (depths below s.l.). the monticelli terme madregolo fontevivo tectonic high is related to the thrusting of the apennines front. 306 nali, di cui tre sono parzialmente presentate in questo lavoro (figure 3, 4, 5). in secondo luogo sono state utilizzate alcune sezioni geologiche di letteratura particolarmente significative, i.e., tracciato alta velocità (valloni et al., 2003), tracciati n° 27 e 30 del lavoro irsa (bortolami et al., 1979), tracciato n° 8 dello studio rer & eni-agip (1998) e il tracciato i-i’ del lavoro di petrucci et al. (1975). altre sezioni geologiche utili sono riportate negli studi di alifraco et al. (1992a, b), conti et al. (1999) e sagne (1998). in analogia alla descrizione di beretta et al. (1996) l’apparato di conoide può essere diviso in tre settori, qui denominati di valle, margine e pianura, con dimensione assiale di 8, 7 e 15 km, rispettivamente (figure 1, 2, 3). nel tratto di valle le alluvioni rappresentano un’esile copertura, spessa meno di 10 metri, ampia 1-4 km, mentre nel tratto di margine le stesse colmano la struttura sinclinalica con spessori di 50-100 metri; qui la struttura positiva sepolta di madregolo controlla la circolazione sotterranea con una soglia imposta a circa -70 m dal p.c. nel tratto di pianura si apre il vero e proprio ventaglio di conoide (figura 6) con spessore che supera comodamente i 100 m nell’intorno dell’autostrada a1, spessore che risulta in linea con quelli espressi dai restanti corpi di conoide sudpadani (antolini et al., 1999). 4.2 architettura sedimentaria lo scheletro architetturale della conoide alluvionale è ricavato dalla rappresentazione della distribuzione di due semplici categorie di depositi: sedimenti ghiaiosi, ghiaioso-sabbiosi e sabbiosi (idrogeologicamente poroso-permeabili), che risultano potenziale sede di corpi acquiferi, e sedimenti limosi, limo-argillosi ed argillosi (idrogeologicamente semipermeabili o del tutto impermeabili) che rappresentano barriere di permeabilità (guadagnini et al., 2002). i corpi acquiferi e le barriere di permeabilità principali delle successioni carotate nel sottosuolo della pianura sono stati datati con diversi metodi anche per correlazione con i loro analoghi affioranti (di dio et al., 1997; rer & eni-agip, 1998; sagne, 1998). per le età del pleistocene terminale-olocene sono invece disponibili numerose datazioni assolute col metodo del radiocarbonio (valloni et al., 2003). l’illustrazione del quadro stratigrafico locale si appoggia alla sezione di figura 3, allineata lungo l’asse deposizionale del corpo di conoide tardo-pleistocenico del fiume taro. la successione continentale (allogruppo emilianoromagnolo) è notoriamente suddivisa in due alloformazioni, emiliano-romagnola inferiore ed emilianoromagnola superiore; il passaggio è rappresentato da un’importante superficie di inconformità, affiorante al margine sud della pianura, datata su base biostratigrafica a 470.000 anni fa (di dio et al., 1997). sulla trasversale della sezione collecchio-baganzola di figura 3, l’alloformazione emiliano-romagnola inferiore ha spessore di decine di metri nell’asse del bacino marginale e di ordine metrico al tetto della struttura positiva di madregolo. fig. 3 sezione in destra fiume taro (collecchio baganzola) di inquadramento fisico-stratigrafico del quaternario alluvionale, orientata secondo l’asse deposizionale. il tetto del marino è posto a circa 800.000 a bp mentre il limite fra alloformazione emilianoromagnola inferiore e superiore (gruppo aquifero b ed a, rispettivamente) è datato a circa 470.000 a bp (di dio et al., 1997). i principali acquiferi ed acquitardi della conoide gigante del fiume taro sono attribuibili agli stadi isotopici marini (1-6) di letteratura. hydrostratigraphic longitudinal section (collecchio baganzola) of the taro river giant alluvial fan. major aquifers and aquitards are assigned to the (1-6) marine isotopic stages of the literature. f. bedulli & r. valloni 307 all’interno dell’alloformazione emiliano-romagnola superiore, i corpi acquiferi e le barriere di permeabilità principali che compongono l’architettura della conoide gigante del fiume taro rappresentano l’espressione fisica di una sedimentazione a controllo astro-climatico. le relazioni fra i cicli climatici del pleistocene medio-superiore e i caratteri della sedimentazione fluviale, accertate globalmente (es. mol et al., 2000; vandenberghe, 1995) e localmente (vittori & ventura, 1995; djokic et al., 1999; amorosi et al., 1999; muttoni et al., 2003), consentono di associare la deposizione dei corpi acquiferi e delle barriere di permeabilità principali agli stadi isotopici marini dell’ossigeno. in figura 3 i corpi acquiferi e le barriere di permeabilità principali della pianura parmense, espressi negli ultimi due cicli glaciali (riss e wurm dei vecchi autori), sono stati correlati con gli stadi isotopici marini (si) da 1 (comprendente l’intero olocene) a 6 (martinson et al., 1987). nella sezione di figura 3 risalta la particolare continuità dell’unità fine, su cui si annidano i depositi grossolani dello stadio isotopico 6. da questo momento, in coincidenza con l’instaurazione di un megaciclo sedimentario riconosciuto dal nord al sud europa (kukla & cilek, 1996), nella pianura a ovest di parma si sviluppa un corpo grossolano di particolare imponenza, qui denominato conoide gigante del fiume taro; le unità fini intercalate in tale corpo assumono spessori e continuità significative solo ad una certa distanza dal fronte della struttura positiva di madregolo e comunque a valle del tracciato della via emilia. riassumendo, gli elementi architetturali di particolare rilievo idrostratigrafico sono rappresentati (1) dalla suddetta barriera di permeabilità con tetto a circa 180.000 anni fa, (2) dalla soglia strutturale di madregolo e (3) dalla pendenza delle barriere di permeabilità, che aumenta per quelle via via più profonde. sulla verticale dell’autostrada a1 la barriera di permeabilità deposta al tempo dello stadio isotopico 3 si incontra a circa 40 m di profondità ed ha una pendenza del 0,8 % (0,47 gradi), la barriera di permeabilità deposta al tempo dello stadio isotopico 5 si incontra a circa 80 m di profondità ed ha una pendenza del 1,4 % (0,81 gradi), e la barriera di permeabilità che precede lo stadio isotopico 6 si incontra a circa 130 m di profondità ed ha una pendenza del 1,9 % (1,08 gradi). nelle figure 4 e 5 sono riportate due sezioni fig. 5 sezione immediatamente a sud dell’autostrada a1 (fontevivo casalbaroncolo) trasversale all’asse deposizionale. il corpo di conoide sviluppato all’esterno della struttura positiva di madregolo-fontevivo ha spessore rilevante. all’altezza dell’abitato di fontevivo (ovest) e della città di parma (est) l’accresciuto numero e spessore degli acquitardi esprime un limite di permeabilità. hydrostratigraphic transversal section (fontevivo casalbaroncolo) of the taro river giant alluvial fan. note the relevant thickness of the alluvial fan body and the permeability limits (arrows) to the east and west. fig. 4 sezione lungo la via emilia (parola san prospero) trasversale all’asse deposizionale. il corpo di conoide ha spessore moderato sviluppandosi sul dorso e sul fronte della struttura positiva di madregolo-fontevivo. in corrispondenza dell’abitato di sanguinaro (ovest) e della città di parma (est) il rilevante spessore cumulato degli acquitardi esprime un limite di permeabilità. hydrostratigraphic transversal section (parola san prospero) of the taro river giant alluvial fan. note the moderate thickness of the alluvial fan body and the permeability limits (arrows) to the east and west. struttura fisica della conoide ... 308 distanziate di 3-4 km che illustrano l’architettura della conoide su un taglio pressochè trasversale all’asse deposizionale. risalta in particolare la saldatura dei corpi acquiferi sull’immediato fronte della struttura positiva (figura 4), che genera rapporti di interflow (vigna, 1996) e il vistoso aumento del loro spessore verso nord (figura 5). identicamente, le principali barriere di permeabilità sono sottili e discontinue all’altezza della via emilia e dotate di una certa continuità e spessore, pochi km più a nord, in prossimità dell’autostrada a1. nel settore di massima apertura del ventaglio di conoide, vale a dire sull’allineamento di figura 5 che corre immediatamente a sud dell’autostrada a1, il corpo di conoide del fiume taro presenta un limite ovest all’altezza di fontevivo, ove si chiude in appoggio sulla soglia strutturale (beretta et al., 1999) ed un limite est all’altezza di parma. in corrispondenza di tali limiti i passaggi litologici risultano bruschi e materializzano dei limiti di permeabilità relativamente netti. i depositi sabbiosi di frangia della conoide si interdigitano con quelli di piana alluvionale e di canale dei corsi d’acqua limitrofi che a est sono rappresentati dal paleo-baganza e dal paleo-parma. 5. circolazione idrica dal punto di vista idrogeologico tutta la letteratura è concorde nell’assegnare al subalveo del fiume taro (es. dall’olio et al., 2001; bedulli et al., 2004) un ruolo dominante nella ricarica degli acquiferi della pianura ovest di parma (rossetti, 1976). altrettanto note sono le condizioni dell’entrata in pressione della falda freatica attestate anche da fenomeni di risorgenza delle acque causati da eterogeneità sedimentaria (petrucci et al., 1982). in destra taro la risorgenza avviene immediatamente a nord dell’a1, nell’ intorno di baganzola e viarolo, ove lo sviluppo della copertura fine è assai pronunciato. in sinistra taro la fuoriuscita avviene a sud dell’a1, nell’intorno di fontevivo, a causa dell’effetto ostacolo creato da un corpo ghiaioso sovraconsolidato affiorante in corrispondenza della struttura positiva sepolta. nel settore di margine (da medesano-giarola a madregolo) la conoide esprime un modesto carico piezometrico per l’effetto sfioratore creato dalla struttura di madregolo e il limitato spessore (dell’ordine dei 20 m) dei corpi grossolani poggianti sull’importante barriera di permeabilità, con tetto a 180.000 anni fa (figura 3). anche in termini idrogeologici si può quindi dire che la conoide vera e propria corrisponde al suo tratto di pianura. sul dorso della stuttura positiva di madregolo e sul suo fronte, fino a poco oltre la via emilia, si determinano le condizioni di carico piezometrico e di saldatura ed ispessimento dei corpi acquiferi tali da massimizzare la ricarica dal subalveo del fiume taro. nel settore di pianura della conoide la soglia creata dall’alto strutturale di madregolo rappresenta un controllo primario sulle geometrie deposizionali del sottosuolo e sul campo dei flussi idrici sotterranei. sul fronte dell’alto strutturale si ha la progressiva espansione del corpo di conoide, mentre sul dorso dello stesso i corpi acquiferi risultano saldati fra loro. questi ultimi costituiscono un grande serbatoio che comunica lungostrato con gli acquiferi in pressione posti più a valle (conti et al., 1999). la soglia di madregolo esercita un controllo altrettanto importante sulla circolazione idrica relativa agli acquiferi più profondi e compartimentati (a3 e a4 di fig. 6 schema del contesto strutturale e della dimensione fisica dell’apparato di conoide. in rosso l’inviluppo nel sottosuolo della conoide gigante del fiume taro di età pleistocene medio terminale pleistocene superiore. fronti dei thrust sepolti del substrato marino da di dio et al. (1997), semplificato. assi della struttura positiva del substrato marino da petrucci et al. (1975). sketch map of the subsurface extension (red line) of the taro river giant alluvial fan of latest middle to late pleistocene age. f. bedulli & r. valloni rer & eni-agip, 1998) sottostanti la conoide tardopleistocenica del fiume taro. la figura 3 mostra infatti che in corrispondenza dell’alto strutturale anche l’importante barriera di permeabilità (tetto a 180.000 anni fa), che costituisce la base del corpo di conoide, presenta delle discontinuità che consentono transfert idrico e comunicazione lungostrato con gli acquiferi in pressione più a nord che all’altezza della via emilia si trovano fra -70 e -150 m dal p.c. 6. conclusioni la fitta maglia dei dati di sondaggio rende possibile un approccio fisico-stratigrafico al problema della ricarica degli acquiferi nell’ambito della conoide gigante del fiume taro. nel contesto di margine di pianura qui studiato le forzanti della sedimentazione risultano il controllo tettonico, il cui aspetto più evidente è rappresentato dai thrust frontali della catena sepolta, e la sua modulazione da parte del fattore climatico che, fra l’altro, controlla il tasso degli apporti trasversali dai fiumi appenninici. lo schema d’alimentazione idrica della conoide gigante del fiume taro indica una ricarica remota degli acquiferi profondi della media pianura; tale modello potrà essere esteso agli altri settori del margine sud-padano caratterizzati dallo stesso stile deformativo a thrust sepolti. dalla ricostruzione fisica risulta che l’apparato di conoide può essere diviso in tre settori, detti di valle, margine e pianura. nel tratto di valle, esteso 8 km da fornovo a medesano, le alluvioni sono spesse meno di 10 m. nel tratto di margine, esteso 7 km da medesano a madregolo, le alluvioni hanno spessore limitato e la circolazione è controllata dall’alto strutturale che ne costituisce la soglia nord. nel tratto di pianura si sviluppa un ampio ventaglio alluvionale con estensione radiale di 15 km e dimensione trasversale massima di quasi 20 km. l’alto strutturale che corre all’altezza di madregolo rappresenta un controllo primario sulle geometrie deposizionali del sottosuolo e su quelle dei flussi idrici sotterranei. la conoide gigante del fiume taro, intesa sia in senso sedimentologico che idrogeologico, è propriamente rappresentata dal grande ventaglio sedimentario di pianura con apice sulla soglia di madregolo. più propriamente la conoide è costituita dal corpo grossolano, formatosi negli ultimi 180.000 anni, che comprende gli stadi isotopici fino al 6. l’imponente acquitardo su cui poggia la conoide si trova a meno di -30 m dal p.c. in corrispondenza della soglia di madregolo e a ben oltre 100 m dal p.c. dieci km più a nord. le sezioni idrostratigrafiche tracciate secondo l’asse deposizionale (direzione circa nord-sud) mettono in luce importanti saldature fra corpi grossolani sul dorso e sul fronte della soglia e la loro compartimentazione, progressivamente crescente verso nord, ad opera delle barriere di permeabilità. le sezioni tracciate trasversalmente all’asse deposizionale (direzione circa estovest) individuano importanti limiti di permeabilità in corrispondenza del passaggio al dominio di interconoide. il flusso dal corpo idrico superficiale (fiume taro) alla falda freatica e a quella in pressione è grandemente influenzato dalla struttura positiva di madregolo, in corrispondenza della quale i corpi grossolani, saldati fra loro, offrono un ampio serbatoio alla ricarica dal subalveo del fiume taro. sul fronte nord della struttura, l’accentuata pendenza dei corpi sedimentari determina un rilevante carico idraulico che si esplica su corpi sedimentari anisotropi con prevalenza della componente orizzontale della permeabilità. la conoide gigante del fiume taro è compartimentata da tre barriere di permeabilità principali che assumono una relativa continuità solo a valle della via emilia e che sulla verticale dell’autostrada a1 vengono intercettate a -40, -80 e -130 metri dal p.c. queste barriere consentono di identificare tre unità idrostratigrafiche rappresentate dall’acquifero freatico, che proprio nell’intorno dell’a1 entra in pressione, e da due acquiferi profondi alimentati dal fronte della struttura positiva posta a sud. anche gli acquiferi sottostanti l’importante barriera di permeabilità posta alla base della conoide tardo-pleistocenica (complessi acquiferi padani a3 e a4) possono essere, almeno in parte, ricaricati dalle acque di subalveo del fiume taro per transfert idrico nei corpi grossolani amalgamati sul dorso dell’alto strutturale di madregolo. ringraziamenti gli autori sono riconoscenti al dott. nicola calda per il contributo alla realizzazione dello stereogramma di figura 2. lavori citati alifraco g., beretta g.p., bodria a., cattini z., nespoli m., pecorari m. & zavatti a., (1992a) idrogeologia. in: studi sulla vulnerabilità degli acquiferi 3 alta e media pianura parmense. a cura del consorzio parmense approvvigionamento acqua potabile. pitagora editrice, bologna, 1-35. alifraco g., beretta g.p., bodria a., cattini z., nespoli m., pecorari m. & zavatti a. (1992b) perimetrazione delle zone di rispetto dei campipozzi. in: studi sulla vulnerabilità degli acquiferi 3 alta e media pianura parmense. a cura del consorzio parmense approvvigionamento acqua potabile. pitagora editrice, bologna, 119-152. amorosi a., colalongo m.l., fusco f., pasini g. & fiorini f. (1999) glacio-eustatic control of continental shallow marine cyclicity from late quaternary deposits of the southeastern po plain, northern italy. quaternary research, 52, 1-13. amorosi a., farina m., severi p., preti d., caporale l. & di dio g. (1996) genetically related alluvial deposits across active fault zones: an example of alluvial fan-terrace correlation from the upper quaternary of the southern po basin, italy. sedimentary geology, 102, 275-295. antolini p., carati m., pellegrini m., tomba i., vincenzi d. & zavatti a. (1999) unità idrogeologiche della pianura romagnola ferrarese e bolognese. la vulnerabilità all’inquinamento dell’acquifero principale. atti terzo convegno nazionale sulla protezione e gestione delle acque sotterranee per il terzo millennio, parma 13-15 ottobre 1999. pitagora editrice bologna, quaderni di geologia applicata, 309struttura fisica della conoide ... supplemento 2-1999 (1), 1.149-1.163. bedulli f., conti a., marchi f., rossetti g., valloni r. & zinelli d. (2004) idrodinamica dei flussi dal subalveo alla conoide pleistocenica del fiume taro (parma). riassunti convegno: la geologia del quaternario in italia: temi emergenti e zone d’ombra, roma, 16-18 febbraio 2004 (a cura di giuliana quaglia). aiqua – cnr istituto geologia ambientale e geoingegneria, 98-99. beretta g.p., cattini z., chiari r., pecorari m. & pelosio a. (1996) idrogeologia. in: studi sulla vulnerabilità degli acquiferi 13: pianura parmense (a cura dell'amministrazione provinciale di parma, servizio ambiente e tutela del suolo). pubblicazione gndci-cnr n. 1392, pitagora editrice bologna, 9-28. beretta g.p., chiari a. & gallarati e. (1999) gestione delle aree di salvaguardia di importanti captazioni della provincia di parma: i l campo pozzi di priorato (fontanellato). atti terzo convegno nazionale sulla protezione e gestione delle acque sotterranee per il terzo millennio, parma 13-15 ottobre 1999. pitagora editrice bologna, quaderni di geologia applicata, supplemento 21999 (2), 4.109-4.117. bernini m. & papani g. (1987) alcune considerazioni sulla struttura del margine appenninico emiliano fra lo stirone e l'enza (e sue relazioni con il sistema del f.taro). acta naturalia de l'ateneo parmense, 23 (4), 219-240. bortolami g.c., braga g., dal prà a., francavilla f., giuliano g., manfredini m., pellegrini m., petrucci f., pozzi r., stefanini s. & vuillermin e. (1979) lineamenti idrogeologici della pianura padana. quaderni istituto di ricerca sulle acque del cnr, 28 (2), tipolito cooptip modena, 77 pp (con 56 sezioni geologiche fuori testo). carcano c., di dio g. & piccin a. (2002) architettura del sottosuolo della pianura padana: strumento di conoscenza per lo sviluppo ottimale delle riserve idriche in lombardia e in emilia-romagna. atti del terzo seminario sulla cartografia geologica (a cura di p. barchesi, a. angelelli e s. forni), bologna 26-27 febbraio 2002. servizio geologico sismico e dei suoli regione emilia-romagna, stampa labanti bologna, 32-35. conti a., di dio g., lasagna s. & zinelli d. (1999) approccio idrostratigrafico alla delimitazione delle zone di protezione passiva delle opere di captazione delle acque sotterranee. atti del terzo convegno nazionale sulla protezione e gestione delle acque sotterranee per il terzo millennio, parma 13-15 ottobre 1999. pitagora editrice bologna, quaderni di geologia applicata, 1.183-1.193. dall’olio n., di dio g., & guermandi m. (2001). il percorso metodologico. in: studi sulla vulnerabilità degli acquiferi 15: nuova carta della vulnerabilità del parmense ed indirizzi di tutela delle acque (a cura di g. alifraco, amministrazione provinciale di parma, servizio ambiente e tutela del suolo). pubblicazione gndci-cnr n. 2469, pitagora editrice bologna, 21-32. di dio g. (2001) il quadro delle conoscenze. in: studi sulla vulnerabilità degli acquiferi 15: nuova carta della vulnerabilità del parmense ed indirizzi di tutela delle acque (a cura di g. alifraco, amministrazione provinciale di parma, servizio ambiente e tutela del suolo). pubblicazione gndci-cnr n. 2469, pitagora editrice bologna, 9-20. di dio g., lasagna s., preti d. & sagne m. (1997) stratigrafia dei depositi quaternari della provincia di parma. boll. società paleontologica it. 36 (1-2), 179-187. di dio g. & valloni r. (1997) unità di crescita nei sistemi di conoide alluvionale del tardo quaternario: la risposta dei corsi d'acqua ai cicli climatici e ai movimenti tettonici. riassunti del convegno aiqua: tettonica quaternaria del territorio italiano conoscenze, problemi ed applicazioni, parma 25-27 febbraio 1997, 159-160. djokic d., frassineti g., vasumini i., ravaioli c. & venturelli c. (1999) qualità delle acque sotterranee nel territorio forlivese: conoide del fiume ronco. atti terzo convegno nazionale sulla protezione e gestione delle acque sotterranee per il terzo millennio, parma 13-15 ottobre 1999. pitagora editrice bologna, quaderni di geologia applicata, supplemento 2-1999 (1), 1.195-1.205. ferrarazzo r., ferraresi m. & pacciani m. (1997) l'acquifero della media e alta pianura parmense: analisi geostatistica delle misure piezometriche e interpretazione funzionale del flusso in falda. acque sotterranee, 53, 53-64. guadagnini l., farina m., frontini s. & simoni m. (2002) la funzione degli acquitardi per la determinazione della vulnerabilità geologica – contributo geostatistico e stocastico. atti del terzo seminario sulla cartografia geologica (a cura di p. barchesi, a. angelelli e s. forni), bologna 26-27 febbraio 2002. servizio geologico sismico e dei suoli regione emilia-romagna, stampa labanti bologna, 133-135. idroser spa (1977) progetto di piano per la salvaguardia e l’utilizzo ottimale delle risorse idriche in emilia-romagna: relazione generale. convenzione tra regione emilia-romagna e ente nazionale idrocarburi, coordinamento di progetto tecneco spa, stampa cooptip modena, 10.59 pp. kukla g. & cilek v. (1996) plio-pleistocene megacycles: record of cl imate and tectonics . palaeogeography, palaeoclimatology, palaeoecology, 120, 171-194. marchetti m. (2001) forme e depositi fluviali, fluvioglacial i , lacustri (fluvio, fluvioglacial and lacustrine forms and deposits) . in: note illustrative della carta geomorfologica della pianura padana (a cura di g.b. castiglioni e g.b. pellegrini). suppl. geogr. fis . dinam. quat., iv, 73-104. martinson d.g., pisias n.g., hays j.d., imbrie j., moore t.c. jr., & shackleton n.j. (1987) age dating and the orbital theory of the ice ages: development of a high-resolution 0 to 300.000year chronostratigraphy. quaternary research, 27, 1-29. mol j., vandenberghe j. & kasse c. (2000) river response to variations in periglacial climate in midlatitude europe. geomorphology, 33, 131-148. 310 f. bedulli & r. valloni muttoni g., carcano c., garzanti e., ghielmi m., piccin a., pini r., rogledi s. & sciunnach d. (2003) onset of major pleistocene glaciations in the alps. geology, 31 (11), 989-992. perego s. (1994) evoluzione naturale e antropica del medio e basso corso del f. taro (prov. di parma). acta naturalia de l'ateneo parmense, 30 (1-4), 527. petrucci f., bigi b., cavazzini r., morestori l., panicieri e., pecorari m. & rossetti g. (1975) ricerche sulle acque sotterranee della pianura parmense e piacentina: sezioni interpretative degli acquiferi (parte prima). pubblicazioni istituto di gelogia università di parma, grafiche step editrice parma, 14 pp. petrucci f., bigi b., pecorari m. & vidoni tani m.e. (1982) le risorgive nella pianura parmense e piacentina. geogr. fis. dinam. quat., 5, 277-284. petrucci f., careggio m. & conti a. (1992) le acque nel comune di parma. grafiche step editrice parma, 153 pp. petrucci f., cavazzini r. & conti a. (1983) geologia e morfologia della conoide del f. taro prov. di parma (ed evento alluvionale del 9 novembre 1982). acta naturalia de l'ateneo parmense, 19 (1), 5-23. regione lombardia & eni-agip, (regione lombardia, ente nazionale idrocarburi divisione agip, 2002) geologia degli acquiferi padani della regione lombardia. a cura di c. carcano e a. piccin. s.el.ca. firenze, 130 pp. rer & eni-agip (regione emilia-romagna, ente nazionale idrocarburi divisione agip, 1998) riserve idriche sotterranee della regione emiliaromagna. a cura di g. di dio. s.el.ca., firenze, 120 pp. rossetti g. (1976) le falde freatiche nella pianura parmense tra i fiumi taro ed enza. il frantoio, 8, 12 pp. sagne m. (1998) struttura fisica e aspetti idrogeochimici del bacino idrogeologico dell'alta e media pianura parmense. tesi di dottorato di ricerca in scienze della terra, facoltà di scienze mm.ff.nn. dell'università di parma, 154 pp. severi p., guermandi m., laruccia n. & frassineti g. (2002) cartografia della vulnerabilità degli acquiferi: contributi della geologia dei suoli. atti del terzo seminario sulla cartografia geologica (a cura di p. barchesi, a. angelelli e s. forni), bologna 26-27 febbraio 2002. servizio geologico sismico e dei suoli regione emilia-romagna, stampa labanti bologna, 36-43. tellini c. (2001) altimetria (altimetry). in: note illustrative della carta geomorfologica della pianura padana (a cura di g.b. castiglioni e g.b. pellegrini). suppl. geogr. fis . dinam. quat., iv, 21-32. valloni r., baio m. & bedulli f. (2003) architettura deposizionale del pleistocene superiore nel sottosuolo della media pianura emiliana. riassunti 4° forum italiano di scienze della terra, bellaria 1618 settembre 2003, 125-127. vandenberghe j. (1995) timescales, climate and river development. quaternary science reviews, 14, 631-638. venzo s. (1973) geomorfologia e idrogeologia della zona di fornovo e della paleoconoide del f. taro (parma). cenno all'inquinamento atmosferico in connessione col regime dei venti. acta naturalia de l'ateneo parmense, 9, 183-211. vigna b. (1996) il contributo dell’analisi sedimentologica nella valutazione della vulnerabilità degli acquiferi. atti secondo convegno nazionale sulla protezione e gestione delle acque sotterranee: metodologie, tecnologie e obiettivi, nonantola (mo) 17-19 maggio 1995. pitagora editrice bologna, quaderni di geologia applicata, supplemento 1-1996 (4), 4.129-4.141. vittori e. & ventura g. (1995) grain size of fluvial deposits and late quaternary climate: a case study in the po river valley (italy). geology, 23 (8) 735-738. 311 ms. ricevuto il 1° giugno 2004 testo definitivo ricevuto il 23 luglio, 2004 ms. received: june 1, 2004 final text received: july 23, 2004 struttura fisica della conoide ... microsoft word 00_indice_bm03 available online http:/amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 25 (1), 2012, 41-55 sea level and paleoenvironment during roman times inferred from coastal archaeological sites in trieste (northern italy) romana melis1, stefano furlani2,1, fabrizio antonioli3, sara biolchi1,4, valentina degrassi5 & karin mezgec1 1 dipartimento di matematica e geoscienze, università di trieste, italy 2 dipartimento di geoscienze, università di padova, italy 3 enea, acs, italy 4 dipartimento di scienze della terra, università degli studi di modena e reggio emilia, italy 5 archeotest srl, trieste, italy corresponding author: s. furlani <sfurlani@units.it> abstract: paleoenvironment and sea level markers have been studied from new and published data at two archaeological sites in trieste. results allowed to locate the roman age shoreline, presently buried under the city. archaeological data clearly indicate the presence of a well-organized roman age seaside, which gradually moved offshore. imperial roman age structures have been found at the site located close to the curia building. archaeological finds indicate the subsequent widening of the seafront. during the 1st century bc, a stone wall parallel to the coast already existed at the back of a sandy beach. after the widening of the city, a large quay was built and the seafront moved offshore, covering the former imperial age structures. the quay was used up the 4th century ad. late roman age structures have been found at the site called cavazzeni. the period when the site was abandoned is clearly indicated by the construction of the medieval walls overtopping the roman age structures. the presence of two docks located just in front of the site are reported in several sketches, maps and historical sources dated at the 16th-17th century. microfaunistic composition of sediments indicates that protected sectors of the harbour were built in order to allow the recovering of ships and other coastal activities. archaeological finds together with paleoenvironmental data suggest that vertical tectonic movements in the urban area of trieste are significantly lower in respect of the northern adriatic. in fact, the presence of marine deposits with bad-preserved microfossils at elevations higher than present-day mean sea level is related to the possible occurrence of a violent storm or a tsunami event. for the latter case, radiocarbon date suggests a possible correlation to the 361 ad earthquake occurred along the eastern adriatic coasts. keywords: urban archaeology, microfossils, sea level curves, trieste, italy. 1. introduction archaeological sites along the mediterranean coasts have undergone consistent environmental changes. in particular, the rapid sea level rise occurred during the early holocene has required continuous adaptations of human settlements to the alteration of the natural settings (pirazzoli, 1996; di bella et al., 2011). to this end, several multidisciplinary proxies from archaeological and geological disciplines are generally used to define these changes (lambeck et al., 2004a; marriner & morhange, 2007; antonioli et al., 2009). among them, the study of the coastal bioindicators (microfaunae) recorded in sediments and deposits of archaeological interest allow to reconstruct the ancient coastal paleoenvironments. the microfaunae of these environments consist of foraminifers, ostracods and mollusks (bivalves and gastropods) well known in the mediterranean coastal areas (pérès & picard, 1964; bonaduce et al., 1975; pérès, 1982; jorissen, 1988; cimerman & langer, 1991; sgarrella & moncharmont zei, 1993; montenegro et al., 1998). the coastal geoarchaeology uses these faunae to identify the paleoenvironments (rivers, swamps, marshes, lagoons, marine settings) close to human settlements, as already demonstrated in similar mediterranean coastal archaeological sites (e.g. reinhardt et al., 1994 and sivan et al., 1999 in israel; pugliese et al., 1999 at the aquileia harbour, for italy; goiran et al., 2005; bernasconi et al., 2006; bernasconi et al., 2007; stanley et al., 2008 (a, b) for the coastal settings of egypt; marriner & morhange, 2007, for general mediterranean review; amato et al., 2009 and bernasconi et al., 2010; di bella et al., 2011; mazzini et al., 2011 for italian geoarchaeology; ghilardi et al., 2011 for greece). paleoenvironmental data may integrate or improve data derived from geology and geomorphology and, in the end, they provide useful information to evaluate local sea level changes. sea-level change is the sum of eustatic, glaciohydro-isostatic and tectonic movements (lambeck et al., 2004a). while the first is global and time-dependent, the latter two varies with location, sediment load, compaction and anthropogenic factors; the tectonic factors include all movements that are not eustatic and isostatic (lambeck et al., 2004a), the glacio-hydro-isostatic component of post-glacial sea-level rise has been recently predicted and compared with field data at several coastal sites all over the italian coasts (lambeck et al., 2004a; antonioli et al., 2007, 2009; faivre et al., 2011). the results represent an useful framework for calculating vertical tectonic movements. melis r. et al. 42 the study of the sea-level changes during the late holocene in the northeastern adriatic sea has been studied by a number of authors (degrassi, 1957; d’ambrosi, 1958; fouache et al., 2000; antonioli et al., 2004, 2007; benac et al., 2004, 2008; faivre et al., 2011; degrassi et al., 2008; furlani et al., 2011). several geomorphologic, biological and archaeological markers have been used as source of information from which the relative movements between land and sea can be evaluated. regarding this area, previous studies evidenced that holocene submersion was largely completed about 7 ka (cal) bp and that subsequently the sea level rose slowly up to the current elevation (antonioli et al., 2007, 2009). moreover, marine notches or marine fossils have never been found in this sector at elevation higher than the present mean sea level, excluding a site with marine shells found by antonioli & furlani (2006) nearby pola, at +0.70 m m.s.l. on the whole, recent archaeological, geomorphological and geophysical data indicate for this area a vertical tectonic signal at a rate of about -0.75 mm/yr occurring during the last two millennia. it produces a significant downward displacement of the coastline of about 1.5 m / 1.8 m since roman age (antonioli et al., 2007, 2009). on the contrary, degrassi et al. (2008) and furlani et al. (2011) suggested that, in the same lapse of time, the urban area of trieste should be relatively stable in respect of the northeastern adriatic. the micropaleontological and archaeological results presented in this work aim to refine previous investigations in trieste and both to add more information on the roman age sea-level and the anthropogenic variation of the shoreline. 2. the study area 2.1. geological and geomorphological background the city of trieste (fig. 1) is located in the eastern part of the homonymous gulf (ne italy). the city lies on an eocene turbiditic succession (flysch of trieste), lutetian in age (bensi et al., 2007, tirelli et al., 2008). the area is part of the external dinarides and is affected by a series of thrusts which made the cretaceous-tertiary carbonate succession overlaying the eocene turbiditic one. the compressional tectonics caused by the dinaric orogeny (late jurassic-early oligocene) produced the development of nw-se oriented and sw verging thrusts and the relative foredeep, with flexuring of the mesozoic carbonate and filling by the eocene flysch. late compressional phases also involved the flysch sequence in the thrusts (doglioni & bosellini, 1987; castellarin et al., 1992). a thrust system crossing the gulf of trieste with dinaric orientation, has been recently found from a multichannel seismic survey (busetti et al., 2008, 2010). the system represents the most external dinaric thrusts. it is characterized by intense deformation, in particular within the eocene flysch sequences. it is affected by tectonic activity lasting to the plio-quaternary. the structure deepens toward the northwest, probably due to the offset of ne-sw faults: the monte spaccato fault parallel to the northern istrian coast (cavallin et al., 1978; carobene & carulli, 1981), and a possible fault zone located in the middle of the gulf, separating the northern part from the southern part (busetti et al., 2008, 2010). according to carulli (2011), the monte spaccato and sistiana faults can be responsible for the formation of the gulf of trieste. modelling of gravity data in the gulf of trieste and karst area interpreted the minimum values occurring in the northern corner of the gulf as due to the deepening toward northwest of the limestones and to the increase of flysch thickness (coren et al., 2006). northwestward tilting of the karst area and its surroundings is confirmed also by geodetic data (braitenberg et al., 2005). from a geomorphological point of view, trieste widens on a succession of ridges and valleys, the latter filled by quaternary alluvial and marine deposits. coastal archaeological remains are usually built at the flysch cliff-foot. alluvial deposits are mainly produced by small temporary streams which flow to the sea, sometimes close to the archaeological sites. 2.2. archaeological background regarding the presence of roman age remains in trieste, the archaeological findings discovered in the last decades during urban excavations deeply improved the knowledge of the roman town (maselli scotti, 2008). since 16th century, local historians highlighted the presence of block alignments, wooden poles and harbour structures; coastal remains have been usually fig. 1 study area. geological map of the urban area of trieste (modified from tirelli et al., 2008) with the location of the archaeological sites. on the upper left-hand, a tectonic sketch of the gulf of trieste showing major thrusts and faults in relation to the city of trieste is reported (modified from busetti et al., 2008; carulli et al., 2011; furlani et al., 2011). satellite images have been taken from google maps. sea level and paleoenvironment during roman times inferred from coastal … 43 reported at many sites in trieste. maselli scotti (2008) suggested that the landfills between roman age coastal structures were built at increasing steps, using sandstone blocks for the construction of retaining walls. imperial age structures (late 1st century bc – early 1st century ad) are usually covered by late roman age walls, the latter lying below recent buildings. the maritime vocation of trieste during roman age is proven by the existence of two harbours (maselli scotti, 2008). large remains of two docks (fig. 2a), as part of the so called “porto esterno”, which correspond to the presentday san marco dock basin, were clearly visible during the 18th century, as described by ireneo della croce (1698). they were composed by two large sea walls: the southwestern one was archshaped; it connected the coast to a small island, called "il zucco", now completely covered by the 17th century landfills, while the northernmost is now included in a present-day dock. the architectural project for the construction of the lazaret project of the ökw, wien, 1821describes the presence of an ancient damaged dock which were ruined by storms (fig. 2b). this structure emerged during low tides. the seaside of the inner harbour was found in correspondence of cavana (ventura et al., 2008) and cavazzeni street. local archaeological superintendence found several sandstone blocks belonging to the roman age docks. the existence of a small harbour was suggested from historical maps that show two semi-submerged and ruined piers. they were included in the landfill for the widening of the city and nowadays they lay below modern buildings. archaeological remains are part of the roman age harbour, which presently lies below the 20th century buildings. 3. methods in 2008-2010, during the renovation works carried out in trieste by the “sovrintendenza per i beni archeologici del friuli venezia giulia” (f. maselli scotti and p. ventura excavation director), two archeological sites at “cavazzeni” street and in “piazzetta s.ta lucia”, close to the “curia” palace (fig. 1), were discovered. four bulk samples of sediments, corresponding to different archaeological stratigraphic units (us) were collected at the “cavazzeni” site, along a 1.50 m thick vertical section. additional 10 samples were collected at the “curia” site, along a 1.50 m thick vertical section (fig. 3, 4). the collected samples were washed using respectively 2 mm and 0.063 mm sieves, both to separate the gravelly and the sandy fraction. finally, the sediments were dried in an oven and weighted. the foraminifers were determined in the 0.063 – 2.0 mm sieving fraction. species counts were performed and recorded as number of specimens of each taxon, reported as percentage in tables 1 and 2. selected specimens were examined and photographed by a leica scanning electron microscope at the university of trieste (plate i). identification of foraminifer species follows the mediterranean systematic suggested by le calvez & le calvez (1958), jorissen (1988), cimerman & langer (1991), levy et al. (1992), hottinger et al., (1993) and sgarrella & moncharmont zei (1993). for the consultation of the original taxa description, the ellis and messina online catalogue on for aminifera was used (http://www.micropress. org/). interpretation of the paleoenvironment was established by the comparison of the foraminiferal assemblages examined here and the ecological significance of other associations from several mediterranean coastal areas: tyrrhenian sea (vismara schilling & ferretti, 1987; sgarrella & moncharmont zei, 1993; bellotti et al., 1994), adriatic sea (albani & serandrei barbero, 1990; fig. 2 ancient maps of trieste. a) unknown author, 1745. map from the project for the construction of the borgo dei santi martiri and the new pier “zucco”. two piers are visible just in front of the cavana area (riavez, 1995); b) unknown author, 1821. map from the project for the construction of the lazaret, wien ökw, with the description of an ancient pier “vestigii d’un anticho molo che fu rovinato dagli garbini, e va conducendo fino al zucko, quando il mare e basso resta grande parte al asciuto”. melis r. et al. 44 albani et al., 1991; jorissen, 1988; donnici & serandrei barbero, 2002) and the late quaternary of the po plain near ravenna (fiorini & vaiani, 2001). radiocarbon dates have been provided by the poznan rodiocarbon laboratory, foundation of the adam mickiwicz university (poland). they were calibrated using the calib 5.0 program (stuiver et al., 2005). ostracods were picked directly from sandy fraction and then identified (plate ii). the number of specimens plate i sem photomicrographs of some foraminifer species representative of the studied sites (magnification: bar = 100 µm): 1 elphidium aculeatum; 2 e. pulvereum, side view; 3 e. complanatum, side view; 4 e. crispum, side view; 5 rosalina bradyi, spiral side; 6 r. floridana, spiral side; 7 helenina anderseni, spiral side; 8 nubecularia lucifuga, spiral side; 9 ammonia beccarii, spiral side; 10 discorbis aguayoi, umbilical side; 11 d. aguayoi, spiral side; 12 adelosina carinato-striata, chamber view; 13 triloculina rotunda, chamber side; 14 siphonaperta agglutinans, side view; 15 quinqueloculina nodulosa, side view; 16 quinqueloculina parvula, side view. sea level and paleoenvironment during roman times inferred from coastal … 45 plate ii sem photomicrographs of some ostracod species representative of the studied sites (magnification: bar = 100 µm): 1 pontocythere turbida, right valve; 2 xestoleberis communis, complete carapace in left lateral view; 3 aurila arborescens, right valve; 4 candona neglecta (juvenile specimen), left valve; 5 leptocythere lagunae, complete carapace in left lateral view; 6 neocytherideis fasciata, left valve; 7 hemicytherura videns (juvenile specimen), right valve; 8 schellencandona sp., complete carapace in left lateral view; 9 loxoconcha elliptica, complete carapace in left lateral view; 10 l. stellifera, complete carapace in right lateral view. for each sample was reported in tables 1 and 2; the presence of juveniles was recorded to distinguish autochthonous from allochthonous specimens. the database sources of modern and quaternary ostracods in mediterranean are provided by bonaduce et al. (1975) and breman (1975) for the northern adriatic sea, monmelis r. et al. 46 tenegro et al. (1998) for italian seas and athersuch (1979) and barbeito gonzalez (1971) for cyprus and naxos island, greece. other useful investigations include the nile delta margin core samples that provide information on pre-modern quaternary ostracods (sneh et al., 1986; pugliese & stanley, 1991) and on quaternary ostracods of monastir, tunisia (wouters, 1973). meisch (2000) has been used for fresh-water ostracods. the elevation of dated sea level markers (archaeological remains and sedimentological samples) have been measured by gps surveys. we estimated the elevations and ages of the archaeological benchmarks and evaluated their functional heights on the basis of archaeological interpretations, following lambeck et al. (2004b), antonioli et al. (2007) and auriemma & solinas (2009) advices. elevation errors are calculated from measurements, while the uncertainty in archaeological dating is estimated from the architectural features of the structures and pottery sherds or ceramics found in the archaeological levels. past sea levels are evaluated considering the ‘‘functional height’’ of archaeological structures. it is defined as the elevation of specific architectural parts of the structure with respect to the mean sea level at the time of their construction. it depends on the structure, on its use and on the local tide amplitudes. the functional height also defines the minimum elevation of the structure above mean sea level (antonioli et al., 2007). data have been compared with predicted sea level curve (lambeck et al., 2011) to define the tectonic behaviour of an area. when data are in agreement with the predicted sea level, tectonic stability is suggested. on the contrary, when the elevations of the markers are different from the predicted values, downlift or uplift is suggested. 4. results archaeological and paleoenvironmental data collected in correspondence of two archaeological excavations in trieste, the “curia” site (fig. 3a-c) and the “cavazzeni” site (fig. 4a-c), are hereinafter described. 4.1. the “curia” site the investigations concern the discovery of a luxurious 1st century ad suburban villa overlooking a coastal road. the excavation was carried out under the pavement of the villa. it has revealed a complex stratigraphy, which highlights an impressive arrangement of the shore with a ne-sw trending (usm438). the seaward side was made up of squared blocks which gradually diminish in size upward. excavations indicate the presence of a quay constituted of a 2 m high sea wall (fig. 3a), dated back using ceramics between the 1st century bc and the 1st century ad. it is grounded at -0.3 m a.s.l. on the bedrock of the roman age shore platform (tab. 3). at its base, a sandy beach (us698 us699) occurs. it has been overlaid by sandy levels rich in shell fragments interbedded with plant debris elements. the discovery of abundant ceramic in the stratigraphic sequence permits to date this area at an age ranging between the end of the 1st century bc and the early 1st century ad. later, archaeological structures were covered with filling materials (half of the 1st century ad). in this way, a new coastal road was built on the widened shore. in order to study the microfaunistic composition of this area, seven levels of the archaeological sequence have been selected, from the bottom to the top as follows (fig. 3a): us699: -0.18 m m.s.l., seaward tilted/sloping; us698: -0.15 m m.s.l., tilted/sloping, centimeters sandy level, located only at the base of the quay; us697t: -0.15 m m.s.l., tilted/sloping; blue-gray (alluvial?) clay with abundant rounded sandstone clasts; us696: -0.12 m m.s.l., strongly tilted sloping, levels rich in vegetate materials interbedded with sandy lenses. thickness of this unit increases toward the seaside; us695: -0.10 m m.s.l., sandy levels with centimeter thickness, interbedded with thin organic (vegetate) lenses; us692: +0.40 m m.s.l., plano-convex lens (max thickness 0.5 m) composed by rounded lithic fragments of sandstone. the following units, us691, 690 and 693 are considered as anthropogenic backfilling. the foraminifers of this excavation consist of 24 species pertaining to 12 genera (tab. 1). among them, fig. 3 the archaeological site at curia. a) representative sketch of the site; b) and c) views of the site. sea level and paleoenvironment during roman times inferred from coastal … 47 ammonia beccarii is always present and dominant (frequency from 60.69, us697t to 85.71%, us682), mainly followed by elphidium complanatum and e. crispum, which are absent in the level us692. other species of elphidium are present, such as e. aculeatum, e. jenseni, e. macellum and e. pulvereum, without reaching curia 699 698 697t 696 695 692 depth s.l.m. (m) 0.18 0.15 0.15 0.12 0.10 + 0.40 foraminifers % % % % % % adelosina candeiana (d'orbigny) 0,6 ammonia beccarii (limneo) 71,4 70,6 60,7 62,9 61,9 85,7 ammonia parkinsoniana (d'orbigny) 1,7 1,7 1,8 ammonia tepida (cushman) 4,3 1,4 aubignyna perlucida (heron-allen and earland) 0,5 buccella granulata (di napoli alliata) 0,6 1,4 buliminella elegantissima (d'orbigny) 2,9 elphidium aculeatum (d’orbigny) 2,3 2,3 1,4 0,9 7,1 elphidium complanatum (d’orbigny) 5,7 9,0 12,1 4,3 19,7 elphidium crispum (linneo) 11,4 10,2 4,0 18,6 9,2 elphidium cuvilleri lévy elphidium excavatum (terquem) elphidium incertum (williamson) 0,6 elphidium jenseni (cushman) 1,7 1,2 1,4 7,1 elphidium macellum (fichtel & moll) 1,7 5,2 5,7 1,4 elphidium pulvereum todd 5,7 0,6 4,0 0,5 elphidium punctatum (terquem) 0,6 0,9 nonion pauciloculum cushman 0,6 polymorphina sp. 1,1 1,2 0,5 polymorphina mystriformis williamson 0,0 1,4 quinqueloculina dimidiata terquem 1,2 quinqueloculina lata terquem 0,6 quinqueloculina seminulum (linneo) 0,6 sinuloculina cyclostoma 1,2 siphonaperta aspera (d'orbigny) 1,7 triloculina marioni schlumberger 2,9 0,6 n° of specimens 35 177 173 70 218 14 n° of species 6 11 19 8 12 3 ostracods n° n° n° n° n° n° aurila arborescens (brady) 1 callistocythere sp. x candona neglecta (sars) x candonidae x leptocythere lagunae hartmann 1 loxoconcha stellifera g.w. müller 2 neocytherideis fasciata (brady & robertson) 1 pontocythere turbida (g.w. müller) 1 1x 1 1x xestoleberis communis g.w. müller 1 x tab. 1 curia site: relative abundance of the foraminifera (above) as percentage of each species in respect to the total assemblage; ostracods (below) as number of adult specimens and presence of juveniles is reported with the “x”. melis r. et al. 48 high percentages. ammonia tepida, well preserved, are occasionally present (levels us696 and 695), while quinqueloculina spp. and others miliolids occurs only in the level 697t, where the highest richness of the assemblage is reported. the preservation of the test is generally poor, above all for a. beccarii and e. crispum specimens. the ostracod fauna found in these samples consists of eight species pertaining to eight genera, which are listed in table 1. among them, pontocythere turbida, xestoleberis communis and candona neglecta are the most common species, even if they occur with few specimens; other taxa such as aurila arborescens, leptocythere lagunae, neocytherideis fasciata and loxoconcha stellifera are occasionally present. callistocythere sp. occur only as juveniles. on the whole, the species richness is very limited, up to four species in the level us695, whereas on the levels us696 and us692 the ostracods are absent. the ostracods species identified in this sequence are well-known in the modern mediterranean as representative of freshwater, brackish and marine infralittoral settings; the occurrence of x. communis indicates vegetated bottoms. 4.2. the “cavazzeni” site the archaeological sequence is dominated by an imposing wall structure, usm4 (structural stratigraphic unit, e.g. walls, etc.), carried out with a carefully structured double parament (and bag filling cement), which are recognized as part of the late ancient city walls. its foundational foot, slightly overhanging, which lies at an altitude of 0.0 m m.s.l. with respect to the current sea level, overlies a large terraced structure made of large blocks of sandstone. the latter was recognized as a part of the roman harbour pier (usm77). due to the small size of the excavation, it is impossible to know the structural articulation of this coastal structures: only a small part of the side facing the sea was identified. it consists in minimum two steps about 0.5 m wide. the accurate analysis of the archaeological material, allows to include the us76 in the first half of the 5th century ad. archaeological data is confirmed by radiocarbon dating on bittium reticulatum shell (1550-1580 yrs bp, tab. 4). similarly, some amphorae fragments recovered in the us120 have been dated at an age ranging between the end of 4th and the beginning of the 5th century ad. the radiocarbon date of a b. reticulatum shell found inside the sediment, has pointed out an age of 3250 yrs bp (1250 yrs bc, tab. 4). cavazzeni us120 us76 (bottom) us76 (top) us74 depth s.l.m. (m) -0,35 -0,05 +0,25 +0.50 foraminifers % % % % adelosina carinato-striata wiesner 1,7 adelosina sp. 0,5 ammonia beccarii (limneo) 0,5 9,1 54,5 ammonia parkinsoniana (d'orbigny) 0,6 0,5 9,1 ammonia tepida (cushman) 21,2 20,9 9,1 aubignyna perlucida (heron-allen and earland) 0,8 1,9 buccella granulata (di napoli alliata) 0,3 cibicidella variabilis (d'orbigny) 0,3 cibicides lobatulus (walker & jacob) 0,8 cibicides refulgens monfort 0,5 cornuspira involvens (reuss) 1,1 cribrononion lagunensis albani & serandrei barbero 0,5 discorbis aguayoi bermudez 3,9 11,2 elphidium aculeatum (d’orbigny) 5,3 5,8 18,2 elphidium complanatum (d’orbigny) 3,9 5,8 elphidium crispum (linneo) 18,2 elphidium excavatum (terquem) 0,3 elphidium jenseni (cushman) 2,5 10,2 9,1 elphidium macellum (fichtel & moll) 3,1 5,8 27,3 9,1 elphidium pulvereum todd 28,1 4,4 9,1 elphidium punctatum (terquem) 0,6 haynesina germanica (ehrenberg) 0,6 helenina anderseni (warren) 1,4 9,1 lachlanella compressa (wiesner) 0,6 massilina secans (d’orbigny) 0,5 miliolinella subrotunda (montagu) 1,1 1,9 nonion depressulum (walker & jacob) 1,4 nonion pauciloculum cushman 1,7 nubecularia lucifuga defrance 2,2 1,0 quinqueloculina bosciana d’orbigny 0,3 0,5 quinqueloculina lata terquem 0,8 1,0 quinqueloculina milletti (wiesner) 0,6 quinqueloculina nodulosa wiesner 0,6 3,9 quinqueloculina padana perconig 0,5 quinqueloculina parvula schlumberger 3,1 quinqueloculina seminulum (linneo) 2,8 1,5 quinqueloculina spp. 0,6 1,5 quinqueloculina ungeriana d'orbigny 9,1 rosalina bradyi (cushman) 0,6 0,5 rosalina floridana (cushman) 0,8 14,6 rosalina vilardeboana d'orbigny 1,7 sigmoilina costata schlumberger 0,6 siphonaperta agglutinans (d'orbigny) 0,3 triloculina rotunda d'orbigny 1,9 trochammina inflata (montagu) 4,2 2,4 9,1 n° of specimens 359 206 11 11 n° of species 36 26 8 5 ostracods n° n° n° n° candona neglecta (sars) x x candonidae 2x x x cytherois frequens g.w. müller x hemicytherura videns (g.w. müller) 2 heterocypris salinus (brady) 1x leptocythere lagunae hartmann 1 loxoconcha affinis (brady) 2 loxoconcha elliptica brady x 3 1x loxoconcha rhomboidea (fischer) x 1 loxoconcha sp. x x x schellencandona sp. x 1x 3x x paradoxostoma simile g.w. müller 1 xestoleberis communis g.w. müller 2 xestoleberis plana g.w. müller x tab. 2 cavazzeni site: relative abundance of the foraminifera (above) as percentage of each species in respect to the total assemblage; ostracods (below) as number of adult specimens and presence of juveniles is reported with the “x”. sea level and paleoenvironment during roman times inferred from coastal … 49 in order to study the microfaunistic composition of this paleoenvironments, four levels of the archaeological sequence have been selected, from the bottom to the top as follows (fig. 4a): us120: -0.35 m m.s.l.; us76 (bottom): -0.05 m m.s.l.; us76 (top): +0.25 m m.s.l.; us74: +0.50 m m.s.l. the sedimentary sequence at the “cavazzeni” site is characterized by muddy sands rich in gravel. the latter is more abundant toward the top of the excavation. littoral gastropods are very abundant in the gravelly fraction, in particular well preserved specimens of bittium reticulatum (fig. 4b) and fragments of vegetation in the first three levels (us120, us76-bottom and us76top); moreover they are enriched of carbonized wood fragments and archeological fragments toward the top (us74). the foraminifers found in this excavation account for forty-four species comprised of twenty-three genera, listed in alphabetic order in table 2; ammonia, elphidium and quinqueloculina are the most frequent genera. the recovered taxa are well-known in the modern mediterranean coastal areas, from brackish-water to infralittoral settings (see references reported in the methods). from the bottom (older) to the top (younger) of the vertical section, the number of species strongly decreases from 36 (level us120) to 5 only (us74). in the first level (us120), elphidium pulvereum and ammonia tepida are the dominant species reaching the percentage of 28.13 and 21.17, respectively (tab. 2). other species, such as miliolidae, discorbis aguayoi, e. aculeatum, e. complanatum, e. jenseni, e. macellum and trochammina inflata are well represented, even if in low percentage. in the following level, us76 (bottom), where a slightly decreasing richness is reported (26 species), the presence of a. tepida is nearly constant, while an increasing percentage of d. aguayoi, e. jenseni and rosalina floridana is evidenced. on the contrary, e. pulvereum strongly decreases at a rate consistent with the previous level. in the last two levels, toward the top of the excavation, the foraminiferal assemblage is strongly reduced both in number of species and in number of tests (tab. 2). only few specimens of ammonia beccarii, elphidium crispum, e. macellum and quinqueloculina ungeriana are reported. moreover, these tests are often poorly preserved. it is noted that these samples contain reworked older planktonic foraminifers mixed with autochthonous forms; the reworked foraminifers mainly derive from the eocene flysch bedrock. the ostracod fauna found in these samples consists of fourteen species comprised of nine genera. these are listed in alphabetical order in the table 2. species of candona, schellencandona and loxoconcha are the most frequent taxa, but usually represented by juveniles. in correspondence of the level us76 (bottom), the higher number of species of ostracods is defined by the occurrence of loxoconcha spp., xestoleberis spp., heterocypris salinus and leptocythere lagunae. on the top of the excavation (us74), scattered young specimens of candona spp. occur. these species of ostracods, well-known in the modern mediterranean, are typically representative of freshwater, brackish, brackishinfralittoral and infralittoral conditions (see references reported in the methods). a site name b sample c wgs84 coordinates d elevation (m a.s.l.) e laboratory number f age (14c uncal. bp) g cal age 1sigma (years bp) cavazzeni (us120) bittium reticulatum 45.64861 13.7675 -0.10 poz-15856 3250 ± 55 3074  87 cavazzeni (us76 – bottom) bittium reticulatum 45.64861 13.7675 -0.05 poz-15854 2065 ± 30 1639  48 cavazzeni (us76 – top) bittium reticulatum 45.64861 13.7675 +0.30 poz-15855 2020 ± 30 1576  47 tab. 4 radiocarbon dating. a) site name and archaeological level; b) sample; c) wgs84 centesimal coordinates of the surveyed sites; d) elevation of the sample (m m.s.l.); e) laboratory number of the sample; f) uncalibrated age (years bp); g) calibrated age 1sigma (years bp). a site name b type of marker c wgs84 coordinates d age (years bp) e corrected measured height (m a.s.l.) and reference f functional height (m) g palaeo-sea level (m m.s.l.) h predicted height (lambeck et al. 2011) (m m.s.l.) i vertical tectonic rates (mm/yr) curia sea wall 45.64861 13.7675 200050 -0.30.2 this paper 0.3 -0.60.2 -0.46 -0.07 tab. 3 dated sea level markers in trieste. a) site name; b) type of sea level marker; c) wgs84 centesimal coordinates of the surveyed sites; d) estimated age of archaeological remains (years bp); e) corrected height of the archaeological marker and reference (if published data); f) functional height; g) paleo-sea level (measured + functional height); h) predicted sea level (from lambeck et al., 2011); i) estimated vertical tectonic rate (mm/yr). melis r. et al. 50 5. discussion holocene paleoenvironments of coastal areas are closely related to sea level and its variations. in particular favorable conditions, as in urban environments, the archaeological structures can preserve sedimentological markers which were deposited during their construction or during the employment of coastal artifacts. from a geomorphological point of view, all the coastal structures found out in trieste were roughly located at the flysch cliff foot, which nowadays is completely covered by buildings of the 18th century. the present-day shoreline is, in fact, shifted offshore with respect to the roman age one (fig. 1). two coastal archaeological sites recently found out allowed to reconstruct the roman age sea level and its related environment. moreover, the comparison of surveyed and published data (ventura et al., 2008) concerning the site of cavana provides the trait d’union to support our thesis concerning roman age sea level. moreover, the comparison of their present elevations with predicted sea level curves (e.g. lambeck et al., 2011) allowed to define the tectonic behaviour of the area. the detailed study of archaeological structures and the relative stratigraphic sequences found out at the studied sites highlighted the occurrence of marine deposits at an altitude ranging from -0.35 to +0.50 m m.s.l. since no other marine deposits at altitudes higher than present-day have been found along the whole eastern adriatic coasts, the studied sites are very significant. these marine fossils lay above mean sea level, but they are not directly related to past mean sea levels as they were probably deposited during a storm event or tsunami. even if written historical sources of a tsunami in the gulf of trieste have never been found, marine shells dated in the archaeological level us76 top suggest that they can be related to the 361 ad earthquake occurred in the qvarner area (croatia). a number of authors (pirazzoli, 1980; benac et al., 2004, 2008), in fact, explained the submerged position of the notch along the eastern adriatic coast indicating the co-seismic movement related to this earthquake. archaeological survey in trieste highlights a complex roman age coastal architecture made up of sea walls, docks and piers connected by a coastal road and functional to a wide urban texture. the construction of the waterfront was probably the result of a wide project, gradually started since the 1st-2nd century ad (maselli scotti, 2008) and subsequently modified time after time up to the 5th century ad. the archaeological setting of the curia site highlights that significant land reclamation have been carried out during imperial age too. from a geomorphological point of view, roman age coastal structures have been surveyed in correspondence of the cliff-platform junction. the natural morphology of the shoreline was probably still visible during imperial age, but it was subsequently modified by the following landfills. fig. 4 the archaeological site at cavazzeni. a) representative sketch of the site; b) particular of the level us120 with abundant gastropods and c) view of the site. sea level and paleoenvironment during roman times inferred from coastal … 51 the composition of the foraminiferal assemblage of marine deposits at the base of the wall suggests a high energy shallow marine environment, as highlighted by the dominance of a. beccarii and e. crispum, whom specimens are both well and poorly preserved. the association with some epiphytic forms, such as e. aculeatum and e. pulvereum, indicates some vegetation cover. the stratigraphical sequence seems to indicate the presence of a sandy bar (us699) which separates an inner environment (us696) and an outer one (us697). only level us697t (-0.15 m.s.l.) is indicative of an open marine setting. scattered occurrence of brackish taxa such as a. tepida, e. excavatum, n. pauciloculum suggests a slight influence of freshwater input. the ostracods, which are generally scarce or absent, confirm this paleoenvironmental interpretation. afterward, the imperial age harbour system suffered a widespread crisis during the late roman age (ventura et al., 2008) so important as to remain out of the 5th century defensive system of the city. later, archaeological and micropaleontological data indicate the prograding of the coastline created through the accumulation of filling material (from us692 upward). late roman age coastal structures which overlay an imperial age pier have been discovered at cavazzeni (fig. 4, maselli scotti, 2008; degrassi et al., 2008). the pier could be similar to fluvial dock structures found out at altino (venice, italy, tirelli, 2001), where the fluvial port was terraced, as in trieste, and couplet with wood poles, used for docking and protection of the dock itself (tirelli, 2001). even if the portuality and the harbour environment of trieste was necessarily different, roman age oak poles have been found near the cavazzeni site (ventura, 1996). regarding the cavazzeni site, the microfaunae composition of the levels us120 and us76 (bottom), which are located from –0.35 to –0.05 m m.s.l., represents a shallow-marine infralittoral paleoenvironment, as testified by several species of miliolids and other marine hyaline taxa among the foraminifers, and by species of loxoconcha spp., xestoleberis spp. and hemicytherura videns among the ostracods. the occurrence of epiphytic species such as elphidium spp., rosalina spp. and discorbis aguayoi, indicates the highly vegetate conditions of the bottom, whom remains are abundant in the studied sediments. in particular, d. aguayoi has been frequently found on zoostera noltii leaves (hohenegger et al., 1989). this marine paleoenvironment is influenced by salinity variability, as indicated by the occurrence of a. tepida (> 20% of frequency), a. perlucida, haynesina spp. and t. inflata, which are species of brackish-water affinity characteristic of lagoon, estuarine, or river-mouth environments. the fresh water input is testified also by the presence of ostracods such as candona spp., which is exclusive of lake settings. probably in this shallow coastal environment, highly vegetated, fresh water may also accumulate from small streams or from human harbour activities. considering the good preservation of the microfossils and the abundance of vegetation, it is possible to assume that it was a partially protected environment, maybe a small harbour. in fact, the high occurrence in all the studied levels, but one (us74), of b. reticulatum, which is a marine infralittoral gastropod, could fig. 5 representative sketch of the relations among the archaeological sites at cavazzeni, cavana and curia. fig. 6 predicted sea level curve (lambeck et al., 2011) compared with the elevation of the sea level markers quoted in table 3. melis r. et al. 52 indicate a limited confinement of this area. the accumulation of these shells could be due to the backwash action. 17th century maps (fig. 2) highlight the presence of piers and breakwaters which created sheltered areas behind them along almost the waterfront. dating of pottery sherds and ceramics found out at the studied sites agree with the radiocarbon age on marine shells found out in the same deposits. in the upper part of the sequence (us76 top and us74, from +0.25 to +0.50 m m.s.l.), very few foraminifers always badly preserved are recovered; they are represented by coastal marine taxa of high hydrodynamics such as a. beccarii, a. parkinsoniana and e. crispum, e. macellum, probably transported by violent storm episodes and accumulated in this confined basin or representing a non-protected coastline. ostracods are very scarce and are represented only by juveniles of freshwater species. archaeological materials indicate that the level us74 probably represents a landfill. the archaeological setting of the two sites and the comparison with data collected at cavana (fig. 1, 5; ventura et al., 2008; degrassi et al., 2008) suggests the presence of marine deposits in all the studied sites. thanks to the presence of coastal deposits and the joint analysis of both archaeological remains, micropaleontological data and radiocarbon dating of marine shells, sea level change in the study area was evaluated. regarding the curia site, even if the archaeological structure is poor of information, the presence of a beach deposit located at the base of the coastal wall reduces the errors related to the roman age sea level height. in particular, we compared the archaeological structure to current retaining sea walls scattered along the shoreline northward from trieste. their base is located averagely 0.3 m above mean sea level. according to the hypothetical similarity between present-day and ancient sea walls, we suggest that roman age functionality of the studied sea wall was about 0.3 m (tab. 3). considering an elevation uncertainty of +0.2 m, roman sea level was therefore at about -0.6±0.2 m m.s.l. afterwards, these structures and the related coastal deposits were covered by filling materials, in order to create a new waterfront, moved off-shore (fig. 2). on the contrary, due to the small size of the excavation, it is more difficult to evaluate the role and consequently the functionality of imperial age structures at cavazzeni. therefore it is impossible to evaluate the sea level change which occurred since the time of their construction. degrassi et al. (2008) suggested two hypothesis concerning sea level change in the area. the first hypothesis assumes the tectonic stability, while the latter assumes the vertical downdrop, in agreement with the whole eastern adriatic coast. thank to the availability of new archaeological and micropaleontological data at curia site, we support the first hypothesis. in fact, the comparison of surveyed data and predicted curves (antonioli et al. 2007; lambeck et al., 2011) suggests that limited relative sea level variations occurred since roman age (fig. 6), despite the significant tectonic subsidence of the eastern and northern adriatic coast (antonioli et al., 2007; faivre et al., 2011). data here discussed confirm the tectonic peculiarity of the trieste area suggested by furlani et al. (2011) with respect to the surrounding area. 6. conclusions a detailed analysis of published and new data on archaeological remains and sedimentological deposits at two archaeological sites in trieste allowed to reconstruct the paleoenvironment and the sea level during roman age. at that time, the shoreline was already strongly affected by human activities, as testified by the presence of well-developed coastal structures. afterwards, these structures were covered by 17th century reclamation works. archaeological and micropaleontological data indicate that roman age sea level was 0.6±0.2 m lower than nowadays. therefore the comparison between past sea level and the predicted sea level curve (lambeck et al., 2011) suggests that this sector of the gulf of trieste has been affected by a vertical tectonic downlift of about -0.2 mm/yr since roman age. these data disagree with the higher tectonic subsidence observed along the remaining part of the northern adriatic sea (antonioli et al., 2007). the presence of marine deposits with badpreserved microfossils at elevations higher than current mean sea level suggests the possible occurrence of a violent storm or a tsunami event. radiocarbon dating suggests a correlation with the 361 ad earthquake occurred along the eastern adriatic coasts. this earthquake was considered as the driving factor in the origin of the submerged notch in the same area by pirazzoli (1980) and benac et al. (2004, 2008). acknowledgements we are kindly grateful to prof. nevio pugliese, department of mathematics and geosciences, university of trieste, for micropaleontological advices. moreover we thank two anonymous reviewers for the useful advices. references albani a.d., favero v., serandrei barbero r. (1991) the distribution and ecological significance of recent foraminifera in the lagoon south of venice (italy). revista española de micropaleontologia, 23, 29-45. albani a.d., serandrei barbero r. (1990) i foraminiferi della laguna e del golfo di venezia. memorie di scienze geologiche, 42, 271-341. amato l., guastaferro c., cinque a., di donato v., romano p., ruello m.r., perriello zampelli s., morhange c., russo ermolli e., irollo g., carsana v., giampaola d. (2009) ricostruzioni morfoevolutive nel territorio di napoli. l’evoluzione tardo pleistocenica-olocenica e le linee di riva di epoca storica. méditerranée, 112, 23-31. antonioli f., amorosi a., bondesan a., braitenberg c., dutton a., ferranti l., fontana a., fontolan g., furlani s., lambeck k., mastronuzzi g., monaco c., orrù p. (2009) a review of the holocene sealevel changes and tectonic movements along the italian coastline. quaternary international, 206 (12), 102-133. antonioli f., anzidei m., lambeck k., auriemma r., gaddi d., furlani s., orrù p., solinas e., gaspari a., karinja s., kovacic´ v., surace l. (2007) sea level change during holocene from sardinia and sea level and paleoenvironment during roman times inferred from coastal … 53 northeastern adriatic (central mediterranean sea) from archaeological and geomorphological data. quaternary science reviews, 26, 2463-2485. antonioli f., carulli g.b., furlani s., auriemma r., marocco r. (2004) the enigma of submerged marine notches in northern adriatic sea. quaternaria, 8, 27-36. antonioli f., furlani s. (2006) geomorphological evidences due to recent tsunami (or large storms) in istria. international geological congress on the adriatic area, 19-20 june 2006 urbino, abstract, 4-6. athersuch j. (1979) the ecology and distribution of the littoral ostracods of cyprus. journal of natural history, 13, 135-160. auriemma r., solinas e. (2009) archaeological remains as sea level change markers: a review. quaternary international, 206 (1-2), 134-146. barbeito gonzalez p.j. (1971) die ostracoden des küstenbereiches von naxos (griechenland) und ihre lebensbereiche. mitteilungen hamburg zoologischen museum und institut, 67, 255-326. bellotti p., carboni m.g., di bella l., palagi i., valeri p. (1994) benthic foraminiferal assemblages in the depositional sequence of the tiber delta. bollettino della società paleontologica italiana, 2, 29-40. benac č., juračić m., bacran-petricioli t. (2004) submerged tidal notches in the rijeka bay ne adriatic sea: indicators of relative sea-level change and of recent tectonic movements. marine geology 212 (1-4), 21-33. benac č., juračić m., blašković i., (2008) tidal notches in vinodol channel and bakar bay, ne adriatic sea: indicators of recent tectonics. marine geology 248 (3-4), 151-160. bensi s., fanucci f., pavsic j., tunis g., cucchi f. (2007) nuovi dati biostratigrafici, sedimentologici e tettonici sul flysch di trieste. rendiconti società geologica italiana, 4, 145. bernasconi m.p., melis r., pugliese n., stanley d.j., bandelli a. (2007) faunal analyses in the interpretation of the submergence of substrates beneath herakleion and eastern canopus. in: stanley d.j. et al. (eds.) “underwater archaeology in the canopic region in egypt, geoarchaeology”. oxford centre for marit. archeol.: monogr. 2, univ. of oxford, 59-86. bernasconi m.p., melis r., stanley d.j. (2006) benthic biofacies to interpret holocene paleoenvironmental changes and human impact in alexandria's eastern harbor, egypt. the holocene, 16 (8), 1163-1176. bernasconi m., stanley j.d., caruso c. (2010) sybaris-thuri-copia deltaic settings in calabria, italy: molluscs, associated biogenic components, and ecobiostratigraphy applied to archaeology. journal of coastal research, 26(2), 377-390. bonaduce g., ciampo g., masoli m. (1975) distribution of ostracoda in the adriatic sea. pubblicazioni della stazione zoologica di napoli, 40, 1-304. braitenberg c., nagy i., romeo g., taccetti q. (2005) the very broad-band data acquisition of the longbase tiltmeters of grotta gigante (trieste, italy). journal of geodynamics, 41, 164-174. breman e. (1975) the distribution of ostracodes in the bottom sediments of the adriatic sea. vrije universiteit te amsterdam, academisch preefscrift, 1-165. busetti m., volpi v., barison e., giustiniani m., marchi m., ramella r., wardell n., zanolla c. (2008) cenozoic seismic stratigraphy and tectonic evolution of the gulf of trieste (northern adriatic). proceedings of the “adria 2006 international geological congress on adriatic area”, urbino (italy), 19-20 may 2006, geoacta, special publication, 3, 15-28. busetti m., volpi v., nicolich r., barison e., romeo r., baradello l., brancatelli g., giustiniani m., marchi m., zanolla c., nieto d., ramella r., wardell n. (2010) dinaric tectonic features in the gulf of trieste (northern adriatic). proceedings of the "27° convegno nazionale del gruppo nazionale di geofisica della terra solida (gngts)", trieste (italy), 6-8 october 2008, bollettino di geofisica teorica e applicata, 51(2-3), 117-128. carobene l., carulli g.b. (1981) fogli 40a gorizia e 53a trieste. in: castellarin a. (a cura di), carta tettonica delle alpi meridionali (alla scala 1:2000.000). pubbl.441, p.f. geodinamica (s.p. 5), c.n.r., 813. carulli g.b. (2011) structural model of the trieste gulf: a proposal. journal of geodynamics, 51, 156-165. castellarin a., cantelli l., fesce a.m., mercier j.l., picotti v., pini g.a., prosser g., selli l. (1992) alpine compressional tectonics in the southern alps. relationship with the n-apennines. annales tectonicae, 6(1), 62-94. cavallin a., martinis b., carobene l., carulli g.b. (1978) dati preliminari sulla neotettonica dei fogli 25 (udine) e 40a (gorizia). contributi preliminari alla realizzazione della carta neotettonica d’italia. cnr e progetto finalizzato geodinamica, pubbl. 155, 189-197. cimerman f., langer m.r. (1991) mediterranean foraminifera. slovenska akademija znanosti in umetnosti. opera academia scientiarium et artium slovenica, classis 4, historia naturalis, 30, 118. coren f., marson i., creati n., prodan m., palmieri f., zanolla c. (2006) structural setting of the trieste area from gravity modelling. bollettino di geofisica teorica ed applicata, 47(4), 549-555. cucchi f., pugliese n. (2000) successione stratigrafica, il carso triestino. in: carulli g.b. (ed.) 2000. società geologica 80° riunione estiva, guida alle escursioni, 207-213. d’ambrosi, c. (1958) recenti misure mareografiche confermerebbero il persistere di tendenze epirogenetiche in istria. boll. soc. adriat. sci. nat., 50, 9-25. della croce i. (1698) historia antica, e moderna, e sacra, e profana, della città di trieste, venetia. degrassi a. (1957) i porti romani dell’istria. anthemon, firenze, 119-169. degrassi v., furlani s., scotti f.m., melis r., antonioli f., fonda g. (2008) strutture portuali di via dei cavazzeni (trieste): indicazioni sul livello del mare. terre di mare. l’archeologia dei paesaggi costieri e le variazioni climatiche. auriemma r. & karinja s. (eds), udine, atti del convegno interreg internazionale di studi, trieste, 8-10 novembre 2007, 275-281. melis r. et al. 54 di bella l., bellotti p., frezza v., bergamin l., carboni m.g. (2011) benthic foraminiferal assemblages of the imperial harbor of claudius (rome): further paleoenvironmental and geoarcheological evidences. the holocene, 21 (8), 1243 1257. doglioni c., bosellini a. (1987) eoalpine and mesoalpine tectonics in the southern alps. geologische rundschau 76 (3), 735-754. donnici s., serandrei barbero r. (2002) the benthic foraminiferal communities of the northern adriatic continental shelf. marine micropaleontology, 44 (34), 93-123. faivre s., fouache e., ghilardi m., antonioli f., furlani s., kovačić v. (2011) relative sea level change in istria (croatia) during the last 5 ka. quaternary international, 232, 132-143. fiorini f., vaiani s.c. (2001) benthic foraminifers and transgressive-regressive cycles in the late quaternary subsurface sediments of the po plain near ravenna (northern italy). bollettino della società paleontologica italiana, 40 (3), 357-403. fouache e., faivre s., dufaure j-j., kovačić v., tassaux f. (2000) new observations on the evolution of the croatian shoreline between poreč and zadar over the past 2000 years. zeitschrift für geomorphologie suppl.-bd. 122, 33-46. furlani s., biolchi s., cucchi f., antonioli f., busetti m., melis r. (2011) tectonic effects on late-holocene sea level changes in the gulf of trieste (ne adriatic sea, italy). quaternary international, 232, 144-157. ghilardi m., genc a., syrides g., bloemendal j., psomiadis d., paraschou t., kunesh s., fouache e. (2011) reconstruction of the landscape history around the remnant arch of the klidhi roman bridge, thessaloniki plain, north central greece. journal of archaeological science, 37, 178-191. goiran j.p., marriner n., morhange c., abd el-maguib m., espic k., bourcier m., carbonel p. (2005) évolution géomorphologique de la façade maritime d'alexandrie (égypte) au cours des six derniers millénaires. méditerranée, 104, 61-64. hohenegger j., piller w., baal ch. (1989) reasons for the spatial microdistributions of foraminifers in an intertidal pool (northern adriatic sea). p.s.z.n. i. marine ecology, 10, 43-78. hottinger l., halicz e., reiss z. (1993) recent foraminiferida from the gulf of aqaba, red sea. slovenska akademija znanosti in umetnosti. opera academia scientiarium et artium slovenica, classis 4, historia naturalis, 33, 179. jorissen f.j. (1988) benthic foraminifera from the adriatic sea: principles of phenotypic variation. utrecht micropaleontological bulletin, 37, 174. lambeck k., antonioli f., anzidei m., ferranti l., leoni g., scicchitano g., silenzi s. (2011) sea level change along the italian coast during the holocene and projections for the future. quanternary international, 232, 250-257. lambeck k., antonioli f., purcell a., silenzi s. (2004a) sea level change along the italian coast for the past 10,000 yrs. quaternary science reviews, 23, 1567-1598. lambeck k., anzidei m., antonioli f., benini a., esposito e. (2004b) sea level in roman time in the central mediterranean and implications for modern sea level rise. earth and planetary science letters, 224, 563-575. le calvez j., le calvez y. (1958) repartition des foraminifères dans la baie de villefranche. annales de l’institut océanographique, 35, 159-234. levy a., mathieu r., poignant a., rosset-moulinier m. (1992) foraminifers à arrangement quinqueloculin et triloculin (miliolacea) de méditerranée. revue de paléobiologie, 11 (1), 111-135. marriner n., morhange c. (2007) geoscience of ancient mediterranean harbour. earth science review, 80, 137-194. maselli scotti f. (2008) il porto di tergeste: riflessioni a seguito dei recenti rinvenimenti. terre di mare. l’archeologia dei paesaggi costieri e le variazioni climatiche. auriemma r. & karinja s. (eds), udine, atti del convegno interreg internazionale di studi, trieste, 8-10 novembre 2007, 317-327. mazzini i., faranda c., giardini m., giraudi c., sadori l. (2011) late holocene paleoenvironmental evolution of the roman harbour of portus, italy. journal of paleolimnology, 46, 243-256 meisch c. (2000) freshwater ostracoda of western and central europe. in: schwoerbel j., zwick p. (eds.) sűsswasserfauna von mitteleuropa 8/3. spektrum akademischer verlag, heidelberg, 1522. montenegro m.e., pugliese n., bonaduce g. (1998) shelf ostracods distribution in the italian seas. in: “what about ostracoda? actes 3e congrès européen des ostracodologistes, paris-bierville, france, 1996” bullétin centre recherches elf exploration production, mémoire, pau, 20, 91-101. pérès j.m. (1982) major benthic assemblages. kinne o. (eds) marine ecology. john wiley & sons ltd., chichester, 5 (1), 373-522. pérès j.m., picard j. (1964) nouveau manuel de bionomie benthique de la mer méditerranée. recueil des travaux, station marine d'endoume, 31, 1137. pirazzoli p.a. (1980) formes de corrosion marine et vestiges archeologique submerges: interpretation neotectonique de quelques exemples en grece et en yougoslavie. annals de l’institut de oceanographique, 56, 101-111. pirazzoli p.a. (1996) sea-level changes. the last 20000 years. john wiley and sons ltd., chichester, 211. pugliese n., maselli scotti f., franchini d. (1999) micropalaeontology in archaeology research: draft of late quaternary evolution of the alluvial plain near aquileia (ne italy). revista espanola de micropaleontologia, 31(3), 403-410. pugliese n., stanley d.j. (1991) ostracoda, depositional environments and late quaternary evolution of the eastern nile delta, egypt. il quaternario, 4(2), 275-302. reinhardt e.g., patterson r.t., schröeder-adams c.j. (1994) geoarchaeology of the ancient harbour site of caesarea maritima, israel: evidence from sedimentology and paleoecology of benthic foraminifera. journal of foraminiferal research, 24(1), 37-48. riavez p. (1995) il porto antico di trieste. osservazioni sulle strutture portuali attestate nella zona di sea level and paleoenvironment during roman times inferred from coastal … 55 cavana precedentemente alla costruzione del borgo giuseppino. atti e memorie società istriana di storia patria, 95 della raccolta (xliii nuova serie), 59-89. sgarrella f., moncharmont zei m. (1993) benthic foraminifera of the gulf of naples (italy): systematics and autoecology. bollettino della società paleontologica italiana, 32 (2), 145-264. sivan d., gvirtzman g., sass e. (1999) quaternary stratigraphy and paleogeography of the galilee coastal plain, israel. quaternary research, 51, 280-294. sneh a., weissbrod t., ehrlich a., horowitz a., moshkovitz s., rosenfeld a. (1986) holocene evolution of the northeastern corner of the nile delta. quaternary research, 26, 194-206. stanley j.d., bernasconi m. p., jorstad t. f. (2008a) pelusium, an ancient port fortress on egypt’s nile delta coast: its evolving environmental setting from foundation to demise. journal coastal research, 24 (2), 451-462. stanley j.d., jorstad t.f., bernasconi m.p., stanford d., jordy m. (2008b) predynastic human presence discovered by core drilling at the northern nile delta coast, egypt. geology, 36 (8), 599-602. stuiver, m., reimer, p. j., reimer, r. w. (2005) calib 5.0. calib radiocarbon calibration, execute version, 5.0.2. http://calib.qub.ac.uk/calib. tirelli m. (2001) il porto di altinum. antichità altoadriatiche, 46, 295-316. tirelli t., ravalico m., cucchi f., zini l., pugliese n., fanzutti g.p., fontana a., tunis g., fanucci f., covelli s., marocco r. (2008) carta di sintesi geologica geo-c.g.t. 1:10000. foglio 110 trieste, sezioni 110100, 110130, 11140 disgam_università di trieste & servizio geologico r.a. friuli venezia giulia, trieste. ventura p. (1996) tergeste romana: elementi per forma urbis. archeografo triestino, 56 (4), 13-112. ventura p., degrassi v., petrucci g. (2008) le strutture portuali di via cavana a trieste. terre di mare. l’archeologia dei paesaggi costieri e le variazioni climatiche. auriemma r. & karinja s. (eds), udine, atti del convegno interreg internazionale di studi, trieste, 8-10 novembre 2007, 328-339. vismara schilling a., ferretti l. (1987) analisi semiquantitativa delle microfaune a foraminiferi e ostracodi nella laguna di s. teodoro (sardegna nordorientale). distribuzione delle associazioni in funzione del grado di confinamento. bollettino dell' accademia gioenia di scienze naturali, 20, 45-92. wouters k. (1973) quelques ostracodes du thyrrhenien de monastir (tunisie). annales des mines et de la géologie, 26, 379-399. ms. received: january 23, 2012 final text received: march 8, 2012 imp. dirita-magri ppoolllleenn aannaallyyssiiss ooff uuppppeerr pplleeiissttoocceennee sseeddiimmeennttss aatt ccaammppoo ffeelliiccee,, cceennttrraall iittaallyy ffeeddeerriiccoo ddii rriittaa11 && ddoonnaatteellllaa mmaaggrrii11 1dipartimento di biologia vegetale, università “la sapienza”, p.le aldo moro, 5 – 00185 rome, italy. abstract: di rita f. & magri d., pollen analysis of upper pleistocene sediments at campo felice, central italy. it issn 0394-3356, 2004. the pollen record from the lacustrine sediments of the campo felice plain (abruzzo, central italy) provides the first palaeovegetational data for the mountain belt of the central apennines during the upper pleistocene. the estimated age of the record is 90,000 years, based on the biostratigraphical correlation with the other long pollen records from central and southern italy. a wooded period at the base of the diagram is correlated with the forest phase st germain ii ss..ll.., while a long time interval of steppe vegetation in the upper part of the record is assigned to the last glacial maximum. the presence, appearance or disappearance of tree taxa (juniperus, pinus, fagus, abies, picea and betula) in the region is inferred from the features of the pollen diagram, which provides also information on a number of lake-level oscillations and sedimentological events. riassunto: di rita f. & magri d., analisi polliniche di sedimenti del pleistocene superiore a campo felice, italia centrale. it issn 0394-3356, 2004. il diagramma pollinico della piana di campo felice (abruzzo) fornisce i primi dati paleovegetazionali per la fascia montana degli appennini centrali, al di sopra di 1500 m, durante il pleistocene superiore. l’età stimata della base della sequenza pollinica, correlata stratigraficamente con altri diagrammi dell’italia centrale e meridionale, è di circa 90.000 anni: un periodo con vegetazione arborea alla base del diagramma è correlato con la fase forestale st germain ii s.l., mentre un lungo intervallo di tempo con vegetazione steppica nella parte superiore del diagramma è interpretato come coevo dell’ultimo massimo glaciale. la presenza, comparsa o scomparsa di alcuni taxa arborei (juniperus, pinus, fagus, abies, picea e betula) nella zona di campo felice vengono ricostruite a partire dal diagramma pollinico, che fornisce anche alcune informazioni su cambiamenti dei livelli lacustri ed eventi sedimentari. keywords: pollen, upper pleistocene, apennines, abruzzo. parole chiave: polline, pleistocene superiore, appennini, abruzzo. il quaternario italian journal of quaternary sciences 1177(1), 2004, 117-127 11.. iinnttrroodduuccttiioonn the palynological study on the campo felice plain is part of a programme of palaeoenvironmental investigations carried out in central italy within a special project of cnr, bringing together researchers in the fields of geology, geomorphology, sedimentology, mineralogy, geochemistry, palaeontology and palynology to study the quaternary palaeoclimate as recorded in continental successions. this work complements the geological and geomorphological investigations already carried out in the area (giraudi, 1998; 2001), with the aim of providing new insights into the evolution of the campo felice palaeolake and surrounding landscape. it represents the first palynostratigraphical investigation at high elevation on the central apennines, offering new elements for a better comprehension of the vegetation dynamics in the mountain sectors of central italy, which proves to be rather different from that of middle and low elevations sites at the same latitude. 22.. tthhee ssiittee 22..11.. ggeeoollooggyy aanndd ggeeoommoorrpphhoollooggyy the campo felice plain (fig. 1), located at an altitude between 1520 and 1600 m (lat 42°13’n, long 13°27’e), occupies the ground of a closed basin of tectonic origin situated in the northern portion of the mt velino massif. its catchment basin, covering a surface area of about 40 km2, extending for large stretches above 2000 m and reaching 2271 m at vena stellante, is represented by meso-cenozoic limestone ridges (accordi et al., 1986). the tectonic origin of the plain is documented by an important fault, probably active during the holocene, oriented nw-se in the eastern portion of the plain (the mt cefalone fault) and wnw-ese in the western portion (the mt orsello fault), displacing a limestone monocline raising at the northern edge of the plain. the movement of this fault truncated a valley whose head, lying between mt cefalone and mt serralunga, is represented by the forcamiccia pass. this valley, that was one of the main outflow ways of the campo felice basin, was possibly partly covered by the sediments of campo felice. in fact, the survey of two deep boreholes in the plain, in front of the forcamiccia pass, suggests the existence of the valley underneath the quaternary cover (giraudi, 1998). lacustrine terraces and ridges, between 1527 m and 1540 m, suggest for this basin lake level oscillations of nearly 13 m during the last 30,000 years, which are believed to have been mainly produced by climatic factors, in spite of the presence of small ponors in the plain (giraudi, 2001). 118 f. di rita & d. magri most of the sediments outcropping on the plain represent deposits of glacial, fluvioglacial, alluvial, lacustrine, and aeolian origin, datable to the upper pleistocene and holocene (giraudi, 2001). in a few restricted portions of the plain, more ancient glacial and detritic sediments are found, probably of middle pleistocene age (giraudi, 1998). an extensive area of the basin (cento monti) is occupied by morains and fluvial sediments, dividing the plain into an eastern and a western portions, where two distinct lacustrine basins were located. the present study deals with the lacustrine sediments of the eastern portion (fig. 1), that was occupied by the widest lacustrine body and was fed by a catchment basin of nearly 24 km2. 22..22.. pprreesseenntt cclliimmaattee aanndd vveeggeettaattiioonn no meteorological stations are found in the campo felice plain, providing direct measures for the current temperature and precipitation values. a station working at rocca di mezzo, a few kilometers away at an altitude of 1329 m, recorded a mean annual temperature of 8˚c in the time span of 30 years (ministero lavori pubblici, 1959-1989); this value is supposedly somewhat higher than in the plain, which lies at a higher elevation. the mean annual precipitation recorded at rocca di mezzo during the same time period is 1013 mm (ministero lavori pubblici, 1959-1989). the mean annual precipitation at campo felice may be estimated as approx. 1300 mm (boni et al., 1986). the campo felice basin has never been the subject of detailed and specific botanical studies, but phytogeographic information is available for the nearby massifs of mt velino (avena & blasi, 1980) and mt sirente (veri & tammaro, 1980). the modern vegetation of campo felice is represented by four main features: pastures, beech forest, shrubland and grasslands above the tree-line. the grass-covered ground represents the main vegetational landscape of the campo felice plain, including both the mountain pastures and the grasslands above the tree-line. the mountain pastures extend over most of the quaternary sediments outcropping on the plain. beech represents the main natural arboreal component at campo felice, where it lives at an altitude from 1550 m to above 1800 m. the beech wood most likely belongs to the typical polysticho-fagetum phytosociological association, assessed for the inland regions of the central apennines. this association was also observed on the mt velino (petriccione, 1993) and mt sirente (veri & tammaro, 1980) massifs. the shrubland is mostly costituted by juniperus communis, subsp. alpina (suter) celak. other important species are: daphne oleoides schreber, arctostaphylos uva-ursi (l.) sprengel, cotoneaster nebrodensis (cuss.) c.koch, rhamnus alpinus l., rosa rubrifolia vill., rosa pendulina l., rosa montana chaix, and chamaecytisus spinescens (presl) rothm. (blasi et al., 1990). the shrubland is generally found above the forest, and reaches an altitude of 2300 m. however on the mt velino massif, because of deforestation for pastures, it is situated at much lower elevations, potentially belonging to the forest vegetation belt (blasi et al., 1990). in the campo felice area the shrub woodland is located both above and just below the beech forest, where juniperus forms very wide and dense blankets. above the shrubland, grassland is the dominant vegetational element, characterized by sesleria tenuifolia schrader, gentiana lutea l., pulsatilla alpina (l.) delarbre, festuca violacea gaudin, luzula italica parl., and plantago atrata hoppe. (avena & blasi, 1980). 33.. mmaatteerriiaallss aanndd mmeetthhooddss 33..11.. ccoorriinngg aanndd lliitthhoossttrraattiiggrraapphhyy a number of sediment cores were collected from fig. 1 -– schematic geological map of the eastern portion of campo felice (simplified from giraudi, 1998). 1. meso-cenozoic bedrock, 2. lacustrine sediments, 3. moraines, scree, breccia, 4. alluvial fans, 5. frontal moraine, 6. lacustrine beach ridge, 7. fault active during the quaternary, 8. location of core cf7. carta geologica schematica della porzione orientale di campo felice (semplificata da giraudi, 1998). 1. substrato meso-cenozoico, 2. sedimenti lacustri, 3. morene, detrito di falda, breccia, 4. conoidi alluvionali e fluvioglaciali, 5. morene frontali, 6. cordone litorale lacustre, 7. faglia attiva nel quaternario, 8. localizzazione del sondaggio cf7. the lacustrine plain of campo felice in septembernovember 1997. the upper 47 m of the core named cf7, the deepest core (123 m) in the eastern portion of the plain, located just in front of the forcamiccia pass (fig. 1), have been the subject of the present palynological work. the recovered lacustrine sediments mainly consist of whitish or light brown calcareous silts, intermixed by volcanic, fluvial, organic sediments and palaeosols (giraudi, 1998). in particular, the sediments of core cf7 indicate a drying of the lake at 27.0-21.6 m where paleosols are found. at 43-42 m there is a level of dark organic sediments. from 47 m to ca. 30 m, the lacustrine sediments are frequently very rich of volcanic materials (giraudi, personal communication). 33..22.. ppoolllleenn aannaallyyssiiss the samples for pollen analysis have been selected and prepared at ca. 1 m interval from the top of the core down to 32 m and mostly at 20-30 cm interval from 32 m to 47 m, where arboreal pollen is more abundant. a total of 96 samples was analysed. they were dried and then chemically treated with hcl (37%), hf (40%) and naoh (10%), with the aim of reducing the detrital sediments and concentrate the pollen grains. a few samples, presenting volcanic ashes even after the chemical treatment, were sieved to eliminate the particles coarser than 250 µm and finer than 7 µm. pollen concentration values were estimated by adding lycopodium tablets to known weights of dry sediment. in all, only 55 samples presented concentration values suitable for pollen counting and representation on the pollen diagrams. in the 3 samples where arboreal pollen (ap) exceeds 50% the mean count was 470 terrestrial pollen grains; while in the 52 samples with more than 50% non-arboreal pollen (nap) the mean count was 199 terrestrial pollen grains. the preservation of the pollen grains was generally modest, the mean percentage of indeterminable grains per sample (degraded, corroded and broken) is 8%. excluding the spores, 59 pollen taxa have been identified, the highest number of taxa per sample being 36 and the lowest 9. according to the morphological characters of quercus pollen described by van benthem et al. (1984), two pollen types were distinguished, deciduous and evergreen quercus. the pollen type named ostrya type includes both ostrya carpinifolia and carpinus orientalis. 44.. rreessuullttss 44..11.. tthhee ppoolllleenn ddiiaaggrraamm the results of the pollen analysis are represented in fig. 2. local pollen zones, defined by subjective zonation, are indicated by the site designation prefix cf followed by core number 7, and are numbered from the base upwards. five pollen zones have been defined. zone cf7-1 (46.57-41.70 m) this zone represents a wood expansion, with maximum ap percentages of 64% at the top of the zone. total pollen concentrations are very disomogeneous, ranging from 900 to over 1,600,000 grains/g. abies is the most important tree taxon. several arboreal taxa reach the highest percentage values of the sequence, although not all at the same depth: alnus (2%) at 46.57 m, deciduous oaks (3%) at 119pollen analysis of upper pleistocene ... 44.55 m, ulmus (2%) at 44.05 m, corylus (1.5%) at 43.25 m, fagus (5%) at 43.25 m, abies (26.5%) at 43.05 m, and picea (9%) at 42.85 m. this succession clearly indicates a forest dynamics with elements of mixed oak forest at the beginning, followed by montane tree taxa (beech and fir) and finally by spruce, as it is commonly observed in many european pollen records in the course of an interglacial cycle (birks, 1986). several ap taxa are sporadically present, with percentages <1%: fraxinus, tilia, salix, betula, populus, and zelkova. pinus shows values of 5-12%, which may not indicate a significant local distribution of pine, whose pollen is frequently over-represented in the pollen diagrams. among the herbs, very high percentages of cichorioideae (max. 66%) are recorded at the base of the zone. gramineae (max. 21%), artemisia (mostly 57%) and caryophyllaceae (5%) are also well respresented. zone cf7-2 (41.70-36.67 m) this zone is characterized by sparse presence of deciduous trees pollen, never reaching 2% altogether. two arboreal taxa show important values: pinus, with a peak of 37% at 41.05 m, is the dominant tree in the lower half of the zone, and juniperus, with a sharp peak of 39% at 38.25 m, is the dominant element in the upper part of the zone. among the other gymnosperms, only picea (4%) and ephedra fragilis type (3.5%) at 38.67 m reach appreciable values. the pollen concentration of ap is generally low, except for pinus (with a peak of over 17,000 grains/g) and juniperus (over 12,500 grains/g). herbs are very abundant and diversified: artemisia is the most important nap taxon, increasing from 23% at 41.55 m to 62% at 37.35 m. other important nap are: cichorioideae (220%, with a single sharp peak reaching 44%), gramineae (max. 10%), asteroideae (max. 7%), chenopodiaceae (max. 6%) and thalictrum (max. 3.5%). zone cf7-3 (36.67-34.23 m) this is a new moderate wood expansion, although less important than in zone cf7-1, as ap percentages reach 46%. pollen concentrations range between 3000 and 45,000 grains/g. abies is the most important tree taxon, peaking 18.5% at 35.18 m. other significant tree taxa are: picea, showing a peak (8.7%) at 34.58 m, fagus (3%), quercus (1.8%). moreover, a number of arboreal taxa are present with very low percentages, including zelkova, with its most recent appearance at 35.08 m. similarly to zone cf7-1, in zone cf7-3 it is possible to recognize a pattern of forest dynamics with different trees expanding one after the other: first deciduous quercus peaking at 36.57 m, then fagus, carpinus betulus, populus and abies at 35.18 m, and finally picea at 34.58 m. among the herbs, cichorioideae are very abundant, together with gramineae and artemisia. zone cf7-4 (34.23-32.05 m) this zone is characterized by high nap values. boadleaved trees do not reach 3% altogether. pinus and juniperus are the only arboreal taxa continuously present. in the lower part of the zone there is a very pronounced peak of artemisia (57%), accompanied by cichorioideae (7%); in the upper part of the zone an increase of cichorioideae (up to 40%) corresponds to a decrease of artemisia (max. 120 22aa )) f. di rita & d. magri 121 f ig . 2 – p ol le n di ag ra m o f c am po f el ic e. d ia gr am m a po lli ni co d i c am po f el ic e. 22bb )) pollen analysis of upper pleistocene ... 122 20%). other signif icant nap are asteroideae, gramineae and caryophyllaceae. the mean pollen concentration is 7300 grains/g. the sediments between 32.05 m and 21.82 m have very low pollen concentrations. for this reason the pollen counts cannot be adequately represented on the diagram, that is interrupted even if the sediment core is available. zone cf7-5 (21.82-5.04 m) – this zone represents a period dominated by herbaceous taxa with only very sporadic apparences of broadleaved trees. the mean ap percentage value is around 20%, including pinus and juniperus, that are the only important arboreal taxa. ephedra fragilis type shows appreciable values, reaching 5% at 21.82 m. the whole zone is characterized by a considerable abundance of artemisia, which is the dominant taxon (always >44% with a peak of 68% at 14.94 m). gramineae (max. 16%) and chenopodiaceae (max. 10%) are also important nap. the pollen concentration values are generally very low, being comprised between 800 and 6150 grains /g. 55.. ddiissccuussssiioonn the interpretation of the floristic data and vegetational dynamics recorded in the pollen diagram cannot omit consideration of the geographic characters of the campo felice plain, in particular of its elevation, above 1500 m a.s.l., which also at present is the main factor affecting the vegetation. 55..11.. vveeggeettaattiioonn cchhaannggeess the time period recorded by the pollen diagram of campo felice shows two distinct vegetational phases each characterized by a significant floristic renewal, deeply changing the landscape: zones cf7-1 to cf7-3 display a certain expansion of arboreal vegetation while zones cf7-4 and cf7-5 are typified by steppe and grassland diffusion. zone cf7-1 represents a vegetational phase characterized by a relatively high number of arboreal taxa (22), even if ap exceeds 50% only in the sample at 43.05 m, where also the pollen concentration is high (>600,000 grains/g). as modern palynological studies indicate that real forest conditions are associated to ap percentage values of at least 75% (reille, 1975), zone cf7-1 cannot be considered a real forest phase, with dense tree cover. however, considering the high elevation of the site, which does not allow even at present a full forest expansion, and the clear vegetation dynamics showing a succession of peaks of deciduous tree taxa and conifers, this zone is certainly indicative of dense tree cover at lower elevations. zone cf7-3 is characterized by a number of arboreal taxa (both conifers and broadleaved trees) similar to zone cf7-1, but with lower ap percentages (max 46%), due to generally lower values of abies, fagus, and floristic elements belonging to the “quercetum mixtum”, such as deciduous oaks, carpinus betulus and ulmus. also in zone cf7-3 a clear succession of arboreal taxa, presently belonging to different vegetational belts, can be recognized, starting with few grains of deciduous quercus, living nowadays at an altitude lower than at campo felice, followed by fagus and abies, and finally by picea, which is presently found on the alps beetwen 1000 and 1900 m (pignatti, 1982). this vegetation dynamics is therefore characterized by a progressive diffusion of mountain arboreal taxa, ending with an open vegetation with juniperus and pinus in zone cf7-4. zones cf7-1 and cf7-3 are separated by a period (zone cf7-2) with steppe and grassland diffusion. ap percentages do not undergo a substantial decrease, as juniperus and pinus maintain high values. this zone displays a decrease of deciduous trees and abies and an increase of artemisia and other herbaceous taxa, such as chenopodiaceae, that altogether are typical components of the cold and arid steppes of the pleistocene glacial stages. this vegetation type is also characteristic of zones cf7-4 and cf7-5, when the presence of deciduous trees and fir is further reduced to very rare appearances. very high percentage values of artemisia, gramineae and chenopodiaceae are presently found both in arid regions with very cold winters (e.g. in the mountainous regions of armenia) and in arid areas between desert and mediterranean vegetation in northern africa, where winters are generally mild. in both cases, the dryness of climate appears to be the main limiting factor for tree growth. 55..22.. fflloorriissttiicc ddiivveerrssiittyy a comparison with the present-day flora of the campo felice area may help in defining which taxa have been continuously present in the vicinity of the site and which have immigrated or disappared from the area. apart from grasses, which are abundantly found throughout the diagram and also at present form the main vegetation type of the campo felice plain, it is worth mentioning the presence of juniperus pollen type in all the samples of core cf7, both in the periods with woody vegetation and with open vegetation. this indicates that the modern abundance of juniperus, representing one of the main vegetational elements of the plain both above and below the beech wood belt, has a long history of local persistence, and that the geographic and climatic features of campo felice have been particularly favourable for the maintenance and development of juniper. another taxon which is continuously well represented in the pollen diagram is pinus, which is however very rare in the modern flora of the area. this abundance can reasonably be interpreted as long distance transport, as pine is a huge pollen producer and its pollen is conspicuously found also in all the other italian pollen records (e.g. follieri et al., 1988; watts et al., 1996; magri, 1999; magri & sadori, 1999). the modern diffusion of fagus around the campo felice plain can be shown to be relatively recent. in fact, while beech is present in zones cf7-1 and cf7-3, with values always <6%, it completely disappears in zones cf7-4 and cf7-5. this suggests that the modern beech wood was most likely reintroduced in the course of the postglacial forest expansion, migrating from refuge areas which were presumably located at lower elevations, as indicated by the more or less continuous pref. di rita & d. magri sence of beech at other sites of central italy (follieri et al., 1998). in the pollen diagram from campo felice three pollen taxa are recorded that have presently a broken distribution in central italy: abies, picea and betula. the history of the distribution of these genera during the late quaternary has been highlighted in the palynological works from central italy, including valle di castiglione (follieri et al., 1988), lagaccione (magri, 1999), lago di vico (magri and sadori, 1999), stracciacappa (follieri et al., 1998), and lago lungo near rieti (calderoni et al. 1994). abies alba mill., is the only fir species occurring in the italian peninsula; it is found on the alps, on the southern appenines, and at a few isolated sites on the central and northern appenines (quezel, 1980). in the abruzzo region abies is presently found as a relic, associated with fagus in a few beech-wood stands of very cold sites in the teramo province (zodda, 1967; longhitano & ronsisvalle, 1974). the long pollen records from central italy show that fir was very rare during the eemian, corresponding to marine isotope stage (mis) 5e, while it characterized both the st germain periods which are the last forest phases before the postglacial (mis 5d and 5a) (follieri et al., 1998). after these forest phases, abies pollen is only sporadically recorded, probably from far origin. in fact, abies is continuously represented in pollen diagrams from both southern italy, at lago grande di monticchio in basilicata (watts, 1985; watts et al., 1996), at canolo nuovo in calabria (grüger, 1977), and in a marine core from the tyrrhenian sea (rossignol strick and planchais, 1989), and from northern italy in the apennines (bertoldi, 1980; lowe and watson, 1993; watson, 1996). these pollen data show that the present-day broken distribution of abies is the result of a strong reduction occurred during the last pleniglacial especially in central italy. at campo felice abies shows the typical trend of the other sites from central italy, being an important tree taxon during the wood expansions of zones cf7-1 and cf7-3, and disappearing during the open vegetation zone cf7-5. picea is one of the most characteristic taxa of the campo felice record. according to the present-day pollen-vegetation relationships (huntley & birks, 1983; hicks, 1994), pollen percentage values higher than 5% indicate a local presence of picea. in the campo felice record seven samples show values of spruce above this percentage threshold. in particular, two peaks of picea (attaining 9%) are recorded in zones cf7-1 and cf7-3, indicating that this taxon was one of the main floristic elements of the wooded landscape at the end of the arboreal succession. the late-quaternary history of picea in central italy starts with a spread at the end of the st germain ii forest phase (mis 5a) in all the pollen sites of the lazio region, where a second increase took place during the middle pleniglacial interstadials (follieri et al., 1998). the modest percentage values recorded around 20,000 bp at lago di vico and stracciacappa represent the last expansion of this taxon in the region. in the pollen record from lago grande di monticchio, in basilicata, picea is not recorded (allen et al., 2000). the presence of picea pollen in zones cf7-1 and cf7-3, even if in low percentages, is very remarkable, as its present geographic distribution is very northern: in italy picea abies (l.) karsten lives only on the alps and in very few relic stations in the northern appennines (pignatti, 1982; jalas & suominen, 1973). the sites from lazio provide evidence that, from about 80 ka to 20 ka, the geographical distribution of spruce was definitely more southern than at present. the campo felice record, where picea percentage values are the highest of central italy probably in relation to the high elevation of the mountain ranges, confirms that spruce was also diffused in the abruzzo region. sporadic pollen grains of betula are recorded in 5 samples of zones cf7-1 and cf7-2, never attaining 1%. at present, birch has its range-bulk centered at northern latitudes in europe, but is also present at scattered sites of the italian peninsula (spada et al., 1995). in the abruzzo region small stands of few individuals of betula pendula roth. are found in a few restricted mountain areas. two main hypotheses have been advanced to explain this distribution: agostini (1981) suggests that the present geographic distribution of birch in the italian peninsula is the result of a migration from more northern latitudes during the last pleniglacial. on the contrary, spada et al. (1995) consider the present-day scantiness of birch on the apennines as resulting from an extreme fragmentation of a previously more continuous range, due to reiterated dryness of cl imate during the quaternary glacial cycles. even if it is impossible to state whether the birch pollen of the campo felice diagram was produced by very sparse trees living in the landscape in the vicinity of the lake or by larger stands at a distant location, it clearly appears that the open vegetation of the upper part of the diagram, which is typical of the glacial phases of the quaternary, was unfavourable for the development of betula populations, and that, in the time span recorded by the diagram, there is a general trend towards a decrease of betula, supporting the hypothesis by spada et al. (1995). finally, a taxon is recorded at campo felice which is extinct in the italian peninsula but is present as a relict in sicily (di pasquale et al., 1992). zelkova characterizes the eemian interglacial (mis 5e) at valle di castiglione (follieri et al., 1986). it is continuously recorded during the st germain i and ii forest periods (mis 5d and 5a), but it became rare during the pleniglacial interstadials (mis 3), when it eventually disappared (follieri et al., 1998). a few pollen grains of zelkova are recorded at campo felice in four samples of zones cf7-1 and cf7-3. although these sporadic findings are most likely of far geographic origin, as zelkova is a thermophilous tree, they take on a special value as they may represent an important chronological reference ante quem. 55..33.. bbiioossttrraattiiggrraapphhyy as no radiocarbon data are available for the cf7 core, the chronostratigraphical interpretation of the record can only be based on a comparison of the floristic and vegetational features of the campo felice pollen diagram with the long records from central and southern italy which have an own chronostratigraphical setting. the records from valle di castiglione near rome (follieri et al., 1988), lago di vico (magri & sadori, 1999), lagaccione near lago di bolsena (magri, 1999) and lago grande di monticchio in basilicata (watts et al., 1996, watts et al., 2000, allen et al., 2000) 123pollen analysis of upper pleistocene ... may be particularly useful, even if they are located at much lower elevations (0-700 m a.s.l.) based on the assumption that the studied stretch of core cf7 does not include hiatuses as long as hundred thousand years, the zones at the base of the record, where woodland dominates the landscape, should most likely be correlated with the last forest expansions before the postglacial, that is with phases corresponding to substages of mis 5. however, a correlation with the eemian interglacial (mis 5e) can be definitely excluded, as this was characterized by very termophilous vegetation (follieri et al., 1988), not represented in core cf7. instead, it seems resonable to assign the wooded pollen zones cf7-1 and cf7-3 to the two st germain forest phases (roughly corresponding to mis 5c and 5a, respectively), or with one of the two. the floristic and vegetational features of the st germain periods recorded in the long records of central italy may constitute the basis for this assignment. the st germain i forest period is characterized, both at valle di castiglione (follieri et al., 1988) and at lagaccione (magri, 1999), as well as at lago grande di monticchio (allen et al., 2000) by deciduous oaks and fagus, as the main components of the vegetation, accompanied by carpinus and ulmus. at the end of this forest expansion, abies attains very high percentage and concentration values. the following non-forested phase (melisay ii, mis 5b) is dominated by chenopodiaceae, with very high percentages, not only in the italian sites (valle di castiglione, lagaccione and lago grande di monticchio), but also in other sites of southern europe, such as kopais (tzedakis, 1994) and tenaghi philippon (wijmstra, 1969). the st germain ii sensu lato forest period (fig. 4) is well-represented in the lazio region at lagaccione (magri, 1999) and at lago di vico (magri & sadori, 1999) and partly recorded at valle di castiglione (follieri et al., 1988). in these sites the st germain ii is characterized by two forest oscillations, locally named etruria i and etruria ii, followed by a third minor oscillation (etruria iii) (magri & sadori, 1999). they are separated by two periods in which trees are continuously present, although clearly reduced, as only pinus shows high percentage values. the first two forest phases (etruria i and ii) display very similar vegetation dynamics, starting with deciduous oaks and corylus, followed by an expansion of fagus and carpinus betulus, and ending with an increase of abies, while the third arboreal oscillation (etruria iii) is clearly distinct due to the dominance of deciduous oaks, accompanied by many trees in low percentages, and to the increase of picea, which during the st germain i had very low values. two hypotheses may be advanced to define the biostratigraphical setting of zones cf7-1 and cf7-3. on the basis of the importance of abies, they can be correlated either with st germain i and st germain ii, respectively, or with two different fluctuations of the st germain ii sensu lato forest period. a correlation of zones cf7-1 and cf7-3 with st germain i and st germain ii, respectively, would imply that they are considered to be two remarkable and well distinct wood expansions, separated by a very harsh steppe environment. the presence of picea in zone cf7-1 would not match the floristic characters of st germain i highlighted by the other sites of central italy, where picea pollen is abundantly recorded only during the st germain ii and it is almost absent during the st germain i. the features of the campo felice wood phases correspond to two moderate diffusions of arboreal vegetation separated by a steppe phase in which the elements of the deciduous woodland do not completely disappear and conifers are well represented (fig. 3). for this reason a correlation of zones cf7-1 and cf7-3 with etruria i and etruria ii, respectively, appears much more convincing than a correlation with st germain i and st germain ii. in fact, in the campo felice record, the open vegetation phase (zone cf7-2) between the two wood124 fig. 3 – correlation of the pollen diagrams from lagaccione (magri, 1999), lago di vico (magri & sadori, 1999) and campo felice for the etruria forest phases (partly redrawn from magri & sadori, 1999). correlazione dei diagrammi pollinici di lagaccione (magri, 1999), lago di vico (magri & sadori, 1999) e campo felice per le fasi forestali etruria (in parte ridisegnato da magri & sadori, 1999). f. di rita & d. magri land periods is not as marked as in the melisay ii, between st germain i and st germain ii, in the other long european pollen records. the abundance of picea in zone cf7-1, typical of st germain ii in central italy, is a further evidence in favour of this correlation. the main difference between the wooded zones in the cf7 record (cf7-1 and cf7-3) and those of the coeval other long records from central and southern italy is the scantiness of fagus, which was clearly much more abundant at lower elevations, for example lagaccione (355 m; magri, 1999), lago di vico (510 m; magri & sadori, 1999), and lago grande di monticchio (656 m; allen et al., 2000) than at the high mountain sites. in the long italian records (follieri et al., 1998; allen et al., 2000), soon after the st germain ii there is a steppe phase with no arboreal taxa, excepting pinus and juniperus, corresponding to mis 4, followed by a number of more or less weak forest oscillations corresponding to mis 3, and finally by very marked steppe vegetation during mis 2, before the lateand postglacial reforestation. zone cf7-5 can be easily correlated with the last pleniglacial period, that everywhere in europe is characterized by open vegetation with very high percentage values of artemisia, pinus and gramineae and very low pollen concentrations. also the upper part of the campo felice diagram is represented by samples with very low pollen concentration, indicating a very poor open vegetation, dominated by artemisia, pinus, juniperus, gramineae and chenopodiaceae, and almost lacking in deciduous trees. the floristic features of this period at campo felice are not distinctive enough to individuate the pleniglacial interstadials of mis 3. this may be due either to the high elevation of the site, which did not allow any tree population expansion during those short climate oscillations, or to a lack of record, if the pleniglacial interstadial are chronologically correspond to the sediments from 32 m to 22 m, where the diagram is interrupted. anyway the stratigraphical position of the lacking record would suggest that this could include the sediments corresponding to the middle pleniglacial interstadials. on the basis of these biostratigraphical considerations, the approximate age of the base of zone cf7-1 can be estimated as 90,000 years, that is the age of the beginning of the st germain ii forest period, supported also by the 87±7 ka old ar/ar date of a tephra layer at the base of st germain ii at lago di vico (magri & sadori, 1999). by comparison with the age model proposed for the lago grande di monticchio record (allen et al. 2000), the top of zone cf7-3 may be estimated as approximately 75,000 years old. while it is difficult to define the age of the sediments poor in pollen between 32 m and 22 m, zone cf7-5 can be reasonably assigned to mis 2. holocene sediments, characterized everywhere in italy and southern europe by a rich forest vegetation, are not represented in the cf7 pollen diagram. 55..44.. ppoolllleenn aanndd llaaccuussttrriinnee sseeddiimmeennttaattiioonn the long pollen record of campo felice provides some useful elements for interpreting the sedimentological events occurred in the lacustrine basin of the eastern portion of the plain. the lower part of the cf7 diagram (zones cf7-1 and cf7-3) presents a series of considerable peaks of pollen of cichorioideae. this is often abundant in paleosols or in oxydized sediments, such as cultural layers from caves (bottema, 1975), as it is very resistant to corrosion and its typical morphology can be easily recognized even in deteriorated grains. for this reason high dominance of cichorioideae percentages may be due to differential preservation of pollen grains and may have no value as indicator of steppe or other open vegetation (havinga, 1984). similar resistance has been observed in lycopodium and polypodium spores (havinga, 1984). abundant trilete and monolete spores are recorded in zone cf7-1. in the same levels, very rich in detrital sediments of volcanic origin, signif icant amounts of pseudoschizaea, a bilaterally-symmetrical cell with finger-print-like concentric striations (christopher, 1976; scott, 1992), are recorded. this taxon is considered to be a good indicator for increased soil erosion and possibly also for running water (pantaleón-cano et al., 1996). the contemporary abundance of cichorioideae, pseudoschizaea and spores in zone cf7-1 brings evidence for erosional phases in the catchment basin, possibly accompanied by lowerings of the lake level. several reasons can explain why the sediments between 32 m and 22 m depth are very poor in pollen, including a very scarce pollen production due to sparse vegetation, very fast sediment accumulation rates, drying of the lake, or severe pollen deterioration. in fact, a combination of all these factors may have also occurred, with a drastic lowering of the lake, preventing the conservation of the few pollen grains produced by an open vegetation. this interpretation is also supported by the presence of palaeosols between 23.7 m and 21.0 m depth in core cf7. the stratigraphical position of this stretch of core, between st germain ii and the last glacial stage (corresponding to mis 2) would indicate for this pollen hiatus an age corresponding to mis 3 and maybe part of stage 4. the zone cf7-5, corresponding by and large to the last glacial maximum, shows a continuous and wellrepresented pollen record, with no evidence for important lake lowerings. this result is in agreement with the high level stand demostrated for the campo felice lake by a terrace at 1540 m assigned to mis 2 (giraudi, 2001), and also with the general state of many lakes around the mediterranean region, reaching their highest levels during the last glacial maximum (giraudi, 1989; bartov et al., 2002). 66.. ccoonncclluussiioonnss the pollen record from campo felice offers new insights for a better understanding of the vegetation dynamics occurred in the mountain areas of central italy during the upper pleistocene. in fact, this study represents the first palynostratigraphical investigation at an elevation of over 1500 m a.s.l. in central italy. the chronological interpretation of the record indicates that the age of the sediments at 47 m in core cf7 is approx. 90,000 years. the floristic characters of the lower part of the diagram is correlated with two oscillations of the st germain ii forest period, recorded at four other sites in italy at lower elevations. the upper part of the cf7 diagram is correlated with the last glacial maxi125pollen analysis of upper pleistocene ... mum, characterized by steppe vegetation, as in most of southern europe. several vegetational features of the campo felice plain can be interpreted as an effect of the high elevation of the site, in particular the considerable abundance of juniperus, a taxon always present in the site throughout the last 90,000 years, the infrequency of deciduous tree taxa even during the main wooded phases, the sparse vegetational cover during the last pleniglacial, when campo felice was covered by ice sheets, as documented by the geomorphology of the site (giraudi, 1998; 2001), the significant amount of picea, a tree that during the last glacial period occupied a much more southern position than at present, finding favourable conditions for its growing on the abruzzo mountains. the low abundance of fagus during the wooded zones of the diagram (cf7-1 and cf7-3) is rather unexpected, as nowadays beech represents the main floristic element of the campo felice arboreal cover and is generally the most important tree of the mountain belt of the apennines. a comparison with the other sites in central and southern italy indicates that during the st germain ii phase beech dominated a densely covered vegetation belt at a lower elevation, while the areas over 1500 m were occupied by a more sparse vegetation, in which the most important trees were represented by conifers (abies, picea, juniperus, and pinus). juniperus is currently the only remnant of this vegetation type. the results obtained through this palynological study show that the campo felice plain and the mountain areas of the central apennines deserve further attention. the multidisciplinary integration of geomorphological and sedimentological data with the cf7 pollen record, set in the palynostratigraphical framework established for central italy, allows some inferences to be made on the palaeoenvironmental evolution of the basin and on the reconstruction of lake level variations in relation to climatic events of the upper pleistocene. besides, it would be important to support the chronology of the most significant biostratigraphical events the cf7 core by other sources of evidence, and to study through pollen analysis other sediment records from the campo felice plain. aacckknnoowwlleeddggeemmeennttss we thank maria foll ieri, carlo giraudi and biancamaria narcisi for their helpful comments on the manuscript and quinto fabio nocca for assistance during fieldwork. this work was supported by cnr (progetto speciale: sedimentazione lacustre, paleoambiente, paleoclima) and miur (2002). rreeffeerreenncceess accordi g., carbone f., civitelli g., corda l., de rita d., esu d., funicello r., kotsakis t., mariotti g. & sposato a. (1986) lithofacies map of the latiumabruzzi and neighbouring areas. c.n.r., quaderni della ricerca scientifica,, 111144(5), 223 pp. agostini r. (1981) contributo alla conoscenza della betulla (betula pendula roth.) nell’appennino centro-meridionale e in sicilia e del suo significato fitogeografico. studi trentini di scienze naturali, 5588 (acta biol.), 35-56. allen j.r.m., watts w.a. & huntley b. (2000) weichselian palynostratigraphy, palaeovegetation and palaeoenvironment; the record from lago grande di monticchio, southern italy. quaternary international, 7733--7744, 91-110. avena g.c. & blasi c. (1980) carta della vegetazione del massiccio del monte velino. appennino abruzzese. scala 1:25000. c.n.r., collana programma finalizzato "promozione della qualità dell’ambiente", aq/1/35. roma. bartov y., stein m., enzel y., agnon a. & reches z. (2002) lake levels and sequence stratigraphy of lake lisan, the late pleistocene precursor of the dead sea. quaternary research,, 5577, 9-21. bertoldi r. (1980) le vicende vegetazionali e climatiche nella sequenza würmiana e post-würmiana di lagdei (appennino settentrionale). ateneo parmense, acta naturalia, 1166, 147-175. blasi c., gigli m.p. & stanisci a. (1990) i cespuglieti altomontani nel gruppo del m. velino (italia centrale). annali di botanica (roma), 4488 (suppl. studi sul territorio 7), 243-261. birks h.j.b. (1986) late quaternary biotic changes in terrestrial and lacustrine environments, with particular reference to north-west europe. in berglund b.e. (ed.) handbook of holocene palaeoecology and palaeohydrology. john wiley and sons, chichester, pp. 3-65. boni c., bono p. & capelli g. (1986) schema idrogeologico dell’italia centrale. memorie della società geologica italiana, 3355, 991-1012. bottema s. (1975) the interpretation of pollen spectra from prehistoric settlements (with special attention to liguliflorae). palaeohistoria, 1177, 17-35. calderoni g., carrara c., ferreli l., follieri m., gliozzi e., magri d., narcisi b., parotto m., sadori l., serva l. (1994) palaeoenvironmental, palaeoclimatic and chronological interpretations of a latequaternary sediment core from piana di rieti (central apennines, italy). giornale di geologia, 5566(2), 43-72. christopher r.a. (1976) morphology and taxonomic status of pseudoschizaea thiegart and franz ex r. potonié emend. micropaleontology, 2222(2), 143150. di pasquale g., garfi g. & quezel p. (1992) sur la presence d’un zelkova nouveau en sicilie sudorientale (ulmaceae). biocosme mésogéen, 88(4)9(1), 401-409. foll ieri m., magri d. & sadori l. (1986) late pleistocene zelkova extinction in central italy. the new phytologist, 110033, 269-273. follieri m., magri d. & sadori l. (1988) 250,000-year pollen record from valle di castiglione (roma). pollen spores, 3300, 329-356. follieri m., giardini m., magri d. & sadori l. (1998) palynostratigraphy of the last glacial period in the volcanic region of central italy. quaternary international, 4477--4488, 3-20. giraudi c. (1989) lake levels and climate for the last 30,000 years in the fucino area (abruzzo-central italy) a review. palaeogeography, palaeoclimatology, palaeoecology, 7700, 249-260. 126 f. di rita & d. magri giraudi c. (1998) the late quaternary geologic evolution of campo felice (abruzzo central italy). giornale di geologia, 6600, 67-82. giraudi c. (2001) nuovi dati sull’evoluzione tardo-pleistocenica ed olocenica di campo felice (l’aquila abruzzo). il quaternario, 1144(1), 47-54. grüger e. (1977) pollenanalytische untersuchung zur würmzeitl ichen vegetationgeschichte von kalabrien (süditalien). flora, 116666, 475-489. havinga a.j. (1984) a 20-year experimental investigation into the differential corrosion susceptibility of pollen and spores in various soil types. pollen spores, 2266, 541-558. hicks s. (1994) present and past pollen record of lapland forests. review of palaeobotany and palynology, 8822, 17-35. huntley b. & birks h.j.b. (1983) an atlas of past and present pollen maps for europe: 0-13000 years ago. cambridge university press. cambridge. jalas j. & suominen j. (1973) atlas florae europaeae, 2. gymnospermae. helsinki. longhitano n. & ronsisvalle g.a. (1974) osservazioni sulle faggete dei monti della laga (appennino centrale). notiziario italiano di fitosociologia, 99, 55-82. lowe j.j. & watson c. (1993) lateglacial and early holocene pollen stratigraphy of the northern apennines, italy. quaternary science reviews, 1122, 727-738. magri d. (1999) late quaternary vegetation history at lagaccione near lago di bolsena (central italy). review of palaeobotany and palynology, 110066, 171-208. magri d. & sadori l. (1999) late pleistocene and holocene pollen stratigraphy at lago di vico, central italy. vegetation history and archaeobotany, 88, 247-260. ministero lavori pubblici, servizio idrografico (19591989) annali idrologici. ufficio idrografico di pescara. pantaleón-cano j., pérez-obiol r., yll e.i. & roure j.m. (1996) significado de pseudoschizaea en las secuencias sedimentarias de la vertiente mediterránea de la península ibérica e islas baleares. in: estudios palinológicos. universidad de alcalá de henares, 101-105. petriccione b. (1993) flora e vegetazione del massiccio del monte velino (appennino centrale). ministero agricoltura foreste, collana verde, 9922, 1-126. pignatti s. (1982) flora d’italia. edagricole. bologna. quezel p. (1980) biogéographie et écologie des conifères sur le pourtour méditerranéen. in: pesson, actualités d’écologie forestière. paris, 205-255. reille m. (1975) contribution pollenanalytique à l'histoire tardiglaciaire et holocène de la végétation de la montagne corse. thèse ès sciences, université d'aix-marseille iii, 206. rossignol-strick m. & planchais n. (1989) climate patterns revealed by pollen and oxygen isotope record of a tyrrhenian sea core. nature, 334422, 413416. scott l. (1992) environmental implications and origin of microscopic pseudoschizaea thiergart and frantz ex r. potoinié emend. in sediments. journal of biogeography, 1199, 349-354. spada f., valfrè d., conti f. & isopi r. (1995) longterm dynamics in central apennines (peninsular italy): the case of betula pendula roth. colloques phytosociologiques, 24: 859-871. tzedakis p.c. (1994) vegetation change through glacial-interglacial cycles: a long pollen sequence perspective. philosophical transactions of the royal society of london b, 334455, 403-432. van benthem f., clarke g.c.s. & punt w. (1984) fagaceae. in: punt w. and clarke g.c.s. (eds), the northwest european pollen flora, 44, 87-110. elsevier. amsterdam. veri l. & tammaro f. (1980) aspetti vegetazionali del monte sirente (appennino abruzzese). c.n.r., collana programma finalizzato "promozione della qualità dell’ambiente", aq/1/83. roma. watson c.s. (1996) the vegetational history of the northern apennines, italy: information from three new sequences and a review of regional vegetational change. journal of biogeography, 2233, 805841. watts w.a. (1985) a long pollen record from laghi di monticchio, southern italy: a preliminary account. journal geological society london, 114422, 491-499. watts w.a., allen j.r.m., huntley b. & fritz s.c. (1996) vegetation history and climate of the last 15,000 years at laghi di monticchio, southern italy. quaternary science reviews, 1155, 113-132. watts w.a., allen j.r.m. & huntley b. (2000) palaeoecology of three interstadial events during oxygen-isotope stages 3 and 4: a lacustrine record from lago grande di monticchio, southern italy. palaeogeography, palaeoclimatology, palaeoecology, 115555, 83-93. wijmstra t.a.(1969) palynology of the first 30 metres of a 120 m deep section in northern greece. acta botanica neerlandica, 1188, 511-527. zodda g. (1967) compendio della flora teramana. archivio botanico e biogeografico italiano, 4433, 35101. 127 ms. ricevuto il 20 febbraio 2004 testo definitivo ricevuto il 6 aprile 2004 ms. received: february 20, 2004 final text received: april 6, 2004 pollen analysis of upper pleistocene ... imp. bini & ddeeffiinniizziioonnee ddii aallccuunnii tteerrmmiinnii iinn uussoo nneellllaa ccaarrttooggrraaffiiaa ddeeii ddeeppoossiittii qquuaatteerrnnaarrii ccoonnttiinneennttaallii iinn aammbbiittoo aallppiinnoo aallffrreeddoo bbiinnii11,, aannddrreeaa bboorrssaattoo22,, ffrraanncceessccoo ccaarrrraarroo33,, aallbbeerrttoo ccaarrttoonn44,, ddaanniieellee ccoorrbbaarrii55,, mmaauurriizziioo ccuuccaattoo66,, ggiioovvaannnnii mmoonneeggaattoo77,,88,, && ggiioovvaannnnii bbaattttiissttaa ppeelllleeggrriinnii88 1dipartimento di scienze della terra, università degli studi, via mangiagalli 14, 20133 milano; 2museo tridentino di scienze naturali, via calepina 14, 38100 trento; 3dipartimento di scienze della terra, università degli studi via valperga caluso 35, 10125 torino; 4dipartimento di scienze della terra, università degli studi, via ferrata 1, 27100 pavia; 5ufficio attività generali e di conoscenza del territorio, direzione generale territorio ed urbanistica regione lombardia. via sassetti 32/2, 20124 milano; 6c/o l'ufficio geologia e prove materiali, via val d'ega, n. 48, 39053 cardano (bz); 7dipartimento di georisorse e territorio, università degli studi, via cotonificio, 114, 33100 udine; 8dipartimento di geologia, paleontologia e geofisica, università degli studi, via giotto, 1, 35137 padova. riassunto: bini a. et al., definizione di alcuni termini in uso nella cartografia dei depositi quaternari continentali in ambito alpino. (it issn 0394 – 3356, 2004). in questi anni nuovi approcci metodologici di rilevamento e cartografia dei depositi quaternari continentali hanno consentito l’abbandono del “modello classico” introdotto da penck e brückner (1909) basato sulle quattro glaciazioni, a favore di un approccio che utilizza unità stratigrafiche delimitate da discontinuità e definite secondo ambiti bacinali (idrografici e/o glaciali), inserite in una scala cronologica relativa (unità allostratigrafiche e unità stratigrafiche a limiti inconformi). in questa nota, frutto del confronto tra diversi autori, vengono proposte le definizioni dei termini utilizzati in ambito alpino secondo tale approccio, al fine di chiarirne il significato e precisarne l’utilizzo. in particolare vengono discussi i termini: lgm (last glacial maximum), postglaciale e pre–lgm. il termine lgm indica l'ultimo massimo glaciale locale, senza riferimento alcuno ad unità cronologiche o stratigrafiche. col termine postglaciale si vuole indicare l’insieme di eventi che si succedono a partire dal termine dell’ultima massima espansione glaciale locale, mentre pre-lgm indica l’insieme degli eventi che la precedono. contestualmente alla spiegazione della terminologia introdotta, vengono anche brevemente affrontate le problematiche che ne derivano relativamente alla classificazione di depositi, delle unità ed alle conseguenti ricadute cartografiche, proponendo alcune possibili soluzioni. abstract: bini a. et al., definition of some terms used in the cartography of alpine continental quaternary deposits. (it issn 0394 – 3356, 2004). in the past decade a new approach to cartography and mapping of quaternary continental deposits allowed the abandonment of the now obsolete "classical model" by penck & brückner (1909), which was based on four major glaciations. the new approach utilizes stratigraphic units, which are bounded by discontinuities and defined by following glacial and/or hydrographic basins, framed within a relative chronological scale (allostratigraphic units and unconformity-bounded stratigraphic units). the present paper, which synthesizes different approaches to quaternary continental stratigraphy, proposes a definition of the terminology used in the alpine area, in order to make clear the significance of each term, and assess its proper use. the terms llaasstt ggllaacciiaall mmaaxxiimmuumm ((llggmm)),, ppoosstt--ggllaacciiaall, and pprree––llggmm are here discussed in detail. the term llggmm indicates the last local glacial maximum, without any reference to stratigraphic and chronostratigraphic units. the term ppoosstt--ggllaacciiaall is used to indicate the events which followed the last local glacial expansion. the term pprree––llggmm indicates the events that preceded the last local glacial maximum. furthermore, we here discuss some of the problems of classification that arise following the use of the new terminology, and suggest possible cartographic solutions. parole chiave: lgm, pre-lgm, postglaciale, ubiquitario, indifferenziato, indistinto, keywords: last glacial maximum, pre–lgm, post-glacial, ubiquitary, undifferentiated, indistinct. il quaternario italian journal of quaternary sciences 1177(1), 2004, 75-82 iinnttrroodduuzziioonnee gli studi condotti in questi anni in ambito alpino italiano hanno visto diverse scuole di pensiero affrontare in modo originale le problematiche di rilevamento e cartografia dei depositi quaternari continentali. il confronto che sta avvenendo attualmente fra queste diverse scuole, anche all’interno del progetto carg, mostra come il quadro d’insieme che ne deriva sia sostanzialmente congruente, almeno per quanto riguarda il significato dei corpi cartografati, la cronologia dell’evoluzione quaternaria, e le ricostruzioni paleoambientali che ne conseguono. comune a tutti i differenti approcci è l’abbandono del “modello classico” delle glaciazioni alpine (penck e brückner, 1909), in accordo con quanto sancito nel final report dell’igcp 24 “quaternary glaciations in the northern hemisphere” (s̆ibrava, bowen e richmond, 1986), a favore di un approccio che utilizza unità stratigrafiche inserite in una scala cronologica relativa, secondo i normali principi della geologia. si cartografano cioè corpi sedimentari e non “glaciazioni” o “interglaciali” (ossia eventi climatici), quindi corpi che non vengono più definiti secondo criteri climatici o morfologici, ma sulla base dei caratteri interni e delle discontinuità che li delimitano. a tal fine sono state utilizzate unità stratigrafiche definite fondamentalmente secondo ambiti bacinali 76 a. bini et al. (idrografici e/o glaciali), caratterizzate sulla base delle discontinuità che le delimitano superiormente ed inferiormente, ed ulteriormente dettagliate nelle facies sedimentarie che le compongono (bini et al., 1989; bini, 1997; bini e pellegrini 1998; bini et al., 2001). le unità di riferimento per tale lavoro sono state inizialmente le uunniittàà aalllloossttrraattiiggrraaffiicchhee e, più recentemente, le uunniittàà aa lliimmiitt ii iinnccoonnffoorrmmii (ubsu = unconformity-bounded stratigraphic units), come raccomandato dal servizio geologico nazionale (2001) in considerazione che solo queste ultime risultano formalizzate nella international stratigraphic guide (1994). appare opportuno precisare, tuttavia, che le ubsu non corrispondono in maniera soddisfacente alle caratteristiche delle unità del quaternario continentale in quanto le discontinuità che delimitano queste ultime: 1. non corrispondono necessariamente ad unconformities; 2. hanno solo raramente estensione regionale, come invece è previsto “preferibilmente” per le ubsu; 3. non sono quasi mai “visibili”, come presunto per le ubsu, ma sono più frequentemente solo “tracciabili” per interpolazione. da vari momenti di confronto e scambio di esperienze fra le diverse scuole è emersa l’esigenza comune di precisare il significato di alcuni termini di uso corrente nei vari gruppi che si occupano di rilevamento dei depositi quaternari continentali in ambito alpino; nello stesso tempo la presente nota ha lo scopo di fare conoscere tali termini ed il loro corretto utilizzo anche a quanti non si occupano direttamente di tali problematiche. 11.. llaasstt ggllaacciiaall mmaaxxiimmuumm in senso generale il termine llaasstt ggllaacciiaall mmaaxxiimmuumm (acronimo llggmm) rappresenta l'ultimo massimo glaciale locale. si vuole indicare in questo modo l’ultima grande espansione glaciale llooccaallee, senza riferimento alcuno ad unità cronologiche o stratigrafiche. il termine llooccaallee fa riferimento, in prima approssimazione, a singoli bacini i cui ghiacciai non erano coalescenti e, in seconda approssimazione, all'intero ambito alpino, considerato come locale rispetto al resto dei rilievi europei ed extraeuropei. lo lgm nnoonn iinnddiiccaa ssoollaammeennttee ll''aaccmmee ggllaa-cciiaallee mmaa ll’’iinntteerroo eevveennttoo, comprendendo quindi sia le fasi di avanzata che quelle di ritiro del ghiacciaio (“tardiglaciale” auctorum). dalla definizione sopraesposta derivano alcune considerazioni: a) il termine lgm non va inteso come sinonimo dell’ultima glaciazione a livello globale né deve essere utilizzato come sinonimo di würm, o würm iii; b) lo lgm, come del resto ogni altra glaciazione, non è un evento isocrono, ma la sua durata temporale si riduce progressivamente spostandosi dalle zone più interne della catena alpina agli anfiteatri. 11..11.. ddeeppoossiittii eedd uunniittàà rriiffeerriibbiillii aalllloo llggmm sono essenzialmente riferibili allo lgm i soli depositi glacigenici. nel tracciamento del limite dello lgm devono essere presi in considerazione solamente i depositi glaciali o, in assenza di questi, depositi di contatto glaciale e proglaciali le cui geometrie descrivono il limite della massa glaciale dello lgm (vedi figura 1). la cartografia dei depositi associati allo lgm deve essere impostata secondo una logica di bacini (glaciali e/o idrografici) di pertinenza degli agenti deposizionali che concorrono alla formazione dei depositi, definendo quindi specifiche unità nei vari bacini. in bacini differenti i depositi glaciali legati a tale evento climatico non sono necessariamente sincroni né automaticamente correlabili, da qui la necessità di introdurre il concetto di “massimo glaciale locale”. tale affermazione è valida non solo nel caso di bacini limitrofi, ma si estende all’intero ambito alpino. la contemporaneità degli eventi e la correlabilità dei depositi tra bacini differenti vanno dimostrate mediante l’utilizzo di datazioni o mediante il tracciamento laterale dei limiti nel caso di corpi fra loro in continuità. le unità cartografiche che comprendono i depositi glaciali associati al lo lgm hanno i l rango di sintema/alloformazione. la sigla lgm non deve essere utilizzata per denominare unità; può invece servire per caratterizzarne la descrizione (ad es. nelle note illustrative, sintema di xxx – rappresenta lo lgm). per evitare la possibilità di accorpamenti arbitrari fra aree e bacini differenti, è preferibile che tale caratterizzazione non venga riportata nelle legende delle carte ma solamente all’interno delle note illustrative. la rappresentazione cartografica delle unità riferibili allo lgm dovrebbe privilegiare l’utilizzo di una stessa tonalità di colore estesa su tutti i bacini; le sue suddivisioni nei singoli bacini, ed eventualmente all’interno di questi (es. allomembri/subsintemi), dovrebbero essere evidenziate mediante sigle. le differenze interne, date dalle variazioni laterali di facies, invece andranno rese mediante appositi soprassegni (vedi figura 1). tale scelta di resa cartografica non è vincolante: possono, ad esempio, essere utilizzati colori leggermente diversi per i diversi bacini oppure, colori uguali ma resi con retinature differenti nei diversi bacini, anche per sottolineare la non provata sincronicità delle unità. all'interno delle unità lgm si utilizzano sottounità (subsintemi/allomembri) per definire i depositi glacigenici delle valli secondarie durante la fase di deglaciazione (“tardiglaciale” auctorum). 11..22.. ccoonnssiiddeerraazziioonnii ee pprroobblleemmaattiicchhee iinn ccoorrssoo ddii ddiissccuuss-ssiioonnee il termine llaasstt ggllaacciiaall mmaaxxiimmuumm è diventato di uso corrente da parte di quanti si occupano dello studio del quaternario continentale a livello internazionale (crowley & north, 1991); viene però inteso con diverse accezioni e sfumature1. in considerazione di questo fatto, si è preferito mantenere il termine nella sua dizione inglese, andando però a precisare il significato che tale termine assume nel contesto della ricerca scientifica condotta in ambito alpino italiano. 1il termine lgm nasce, con significato climatico, dalla stratigrafia continentale del nord america, per indicare la massima avanzata della glaciazione wisconsin (würm) nella zona intorno ai grandi laghi, anche se poi viene normalmente utilizzato nella stratigrafia delle carote di ghiaccio ed in quasi tutti i lavori che si occupano dell’ultimo evento glaciale. lgm sensu stricto è stato cronologicamente definito da crowley & north (1991) in base a isotopi e carbonati in oceano e ghiaccio come un intervallo di circa 1500-2000 anni intorno a 18 mila 14c bp e calibrato verso 21 mila cal bp. 77definizione di alcuni termini ... f ig . 1 s ez io ne g eo lo gi ca id ea liz za ta c he e se m pl ifi ca i ra pp or ti st ra tig ra fic i f ra u ni tà q ua te rn ar ie in a re a di a nf ite at ro ; si im m ag in a ch e la s ez io ne s ia t ra cc ia ta p er pe nd ic ol ar m en te a i c or do ni m or en ic i t er m in al i " a" e " b" . i s in te m i x x x e y y y (1 e 2 r is pe tti va m en te ) so no c os tit ui ti da d ep os iti le ga ti a du e di st in te g la ci az io ni ; l ‘u ni tà p os tg la ci al e (3 ) co m pr en de i de po si ti su cc es si vi a ll’ ul tim o ev en to g la ci al e. i de po si ti de l s in te m a y y y so no a ss oc ia ti al l’u lti m o ev en to g la ci al e de ll’ ar ea ( lg m ); ta li de po si ti si s ov ra pp on go no s ol o pa rz ia lm en te a q ue lli d el s in te m a x x x ,s ed im en ta ti da u n pr ec ed en te e ve nt o gl ac ia le ( p re -l g m ). n el la p or zi on e in te rn a de ll’ an fit ea tr o i d ep os iti a llu vi on al i d el l’u ni tà p os tg la ci al e er od on o e ric op ro no i de po si ti flu vi og la ci al i r ife rib ili a llo l g m , m en tr e ne lla p or zi on e es te rn a so no q ue st i u lti m i ad e ro de re e r ic op rir e i d ep os iti f lu vi og la ci al i c or re la ti co l p re ce de nt e ev en to g la ci al e. i li m iti c he d ef in is co no q ue st e un ità s on o di sc on tin ui tà s ig ni fic at iv e; a ll’ in te rn o di o gn i s in te m a, t al i l im iti so no d ia cr on i. il lim ite m as si m o ra gg iu nt o da l g hi ac ci ai o ne ll’ ul tim a gl ac ia zi on e (l im ite l g m ) è m at er ia liz za to d al m ar gi ne in te rn o de lla m or en a te rm in al e b. i n as se nz a di t al e co rd on e, il li m ite d el g hi ac ci ai o pu ò es se re t ra cc ia to , co n m ag gi or g ra do d i a pp ro ss im az io ne , a pa rt ire d al la g eo m et ria d ei d ep os iti d i c on ta tto g la ci al e e/ o pr og la ci al i. la d is tin zi on e fr a le d iv er se f ac ie s de i d ep os iti in u n da to si nt em a è re sa g ra fic am en te m ed ia nt e un a pp os ito s ov ra ss eg no , m en tr e co lo re e s ig la d el s in te m a rim an go no in va ria ti. id ea liz ed g eo lo gi ca l s ec tio n pe rp en di cu la r to t he t er m in al m or ai ne s "a " an d "b " sy nt he si zi ng t he s tr at ig ra ph ic r el at io ns hi p be tw ee n q ua te rn ar y un its in t he a m ph ith ea tr e. s yn th em es x x x an d y y y (1 a nd 2 r es pe ct iv el y) a re m ad e up o f t w o di ffe re nt g la ci at io n de po si ts ; t he p os tgl ac ia l u ni tc om pr is es d ep os its y ou ng er th an th e la st g la ci al m ax im um ( lg m ); t he s yn th em e y y y de po si ts a re r el at ed to th e lo ca l l g m , a nd o ve rli e on ly p ar tia lly th e s yn th em e x x x d ep os its , w hi ch a re r el at ed to a n ol de r gl ac ia l e ve nt ( p re -l g m ). in th e in ne r pa rt o f t he a m ph ith ea tr e th e p os tgl ac ia l u ni t al lu vi al d ep os its e ro de a nd o ve rla p th e flu vi og la ci al l g m d ep os its , w hi le in th e ou te r pa rt th es e la tte r er od e an d ov er la p th e flu vi og la ci al p re -l g m d ep os its . t he b ou nd ar ie s th at d ef in e th es e un its a re s ig ni fic an t d is co nt in ui tie s, a nd w ith in e ac h sy nt he m e th es e bo un da rie s ar e di ac hr on es . t he m ax im um e xt en t r ea ch ed b y th e gl ac ie r du rin g th e la st g la ci at io n (l g m b ou nd ar y) is id en tif ie d by th e in ne r m ar gi n of th e la te ra l m or ai ne " b" . l ac ki ng th is m or ai ne r id ge , t he l g m b ou nd ar y ca n be tr ac ed a pp ro xi m at el y fr om th e ge om et ry o f t he c on ta ct -g la ci al a nd /o r pr og la ci al d ep os its . t he d is tin ct io n be tw ee n di ffe re nt fa ci es w ith in a s yn th em e is g ra ph ic al ly v is ua liz ed b y an o ve rm ar k, w hi le c ol ou r an d sy nt he m e in iti al s re m ai n un ch an ge d. 78 proprio dalle esperienze di rilevamento condotte nell’ambito alpino italiano emerge che quanto è stato cartografato come depositi lgm nelle valli principali si colloca in un intervallo temporale abbastanza ben definito, compreso all’incirca tra 25 e 11 ka bp (date non calibrate), coincidendo quindi con lo stadio isotopico 2. tuttavia, allo stato attuale delle conoscenze, non si è sicuri della stretta contemporaneità degli eventi nei differenti bacini. inoltre, mentre nelle valli principali per i depositi glaciali riferibili allo lgm si osserva questa complessiva convergenza delle età, nelle catene periferiche prealpine (es. monti lessini), contraddistinte da piccoli ghiacciai locali con dinamiche proprie e non necessariamente sincrone con quelle dei grandi ghiacciai vallivi, tale evento può essere antecedente (es. stadio isotopico 4). allo stato attuale dei lavori le unità riferibili allo lgm hanno per la maggior parte i l rango di sintema/alloformazione. il problema del rango si pone però nel caso di bacini molto articolati in cui le valli laterali, nel corso dell’ultimo evento glaciale, hanno ospitato masse glaciali che non sono mai state in relazione diretta con il ghiacciaio vallivo principale e la cui evoluzione non è necessariamente sincrona con questo (e fra di loro). una possibile soluzione potrebbe essere quella di elevare le unità riferibili allo lgm al rango di supersintema/allogruppo. un altro problema si pone per le aree d'alta montagna, dove i distinti ghiacciai vallivi erano uniti in un'unica zona d'accumulo: in questo contesto la suddivisione per bacini delle unità associate allo lgm non ha più significato. in tali contesti sarà necessario individuare soluzioni, sia di nomenclatura delle unità sia di resa grafica, idonee a rappresentare queste peculiari situazioni. 22.. ppoossttggllaacciiaallee per ppoossttggllaacciiaallee si vuole indicare in ambito alpino l’insieme di eventi, che si succedono a partire dal termine dell’ultima espansione glaciale locale. postglaciale non è sinonimo di olocene, ma rappresenta un evento corrispondente ad un arco temporale che va dalla parte terminale del pleistocene superiore all 'olocene. pertanto, il postglaciale così definito non ha il significato di postglaciale presente in taluna letteratura, indicante un intervallo di tempo. 22..11.. ddeeppoossiittii eedd uunniittàà rriiffeerriibbiillii aall ppoossttggllaacciiaallee l’unità postglaciale (acronimo uuppgg) è una unità informale (cfr. 4a) che comprende tutti i depositi che si formano dopo il ritiro del ghiacciaio dello lgm da un data area. è un'unità ubiquitaria (cfr. 4e) ossia, a differenza delle unità associate allo lgm, non viene distinta sulla base dei bacini (idrografici e/o glaciali) di pertinenza degli agenti deposizionali che concorrono alla formazione dei suoi depositi, in quanto il suo limite superiore è l’attuale superficie topografica e può essere seguito con continuità da bacino a bacino. la sua superficie limite inferiore è evidentemente diacrona in quanto coincide con la superficie limite superiore dello lgm. proprio per tale motivo l’unità postglaciale non è equiparabile all’olocene. l’upg possiede il rango di sintema/alloformazione ed è marcatamente diacrona su tutta la sua estensione. in particolari contesti, l’upg potrebbe essere elevata al rango di supersintema/allogruppo. in ambito alpino l’upg può essere suddivisa in sottounità di uso strettamente locale per rappresentare singoli corpi rappresentativi di eventi deposizionali importanti a livello di un dato bacino, o di porzioni significative di questo (es. frane arealmente estese). nelle aree di alta montagna dove si hanno depositi glaciali legati alla piccola età glaciale (peg), evento sincrono per tutti i bacini, sono di uso generale le seguenti sottounità: la sottounità postglaciale inferiore. la sottounità postglaciale peg. la sottounità postglaciale superiore. si precisa che gli aggettivi “inferiore” e “superiore” hanno significato stratigrafico; depositi così denominati, presenti tanto in altri quanto nei medesimi ambiti, non necessariamente sono tra loro sincroni. tale classificazione si riferisce ad un ambito strettamente locale. la rappresentazione cartografica dell ’upg dovrebbe avvenire mediante l’utilizzo di un unico colore esteso su tutti i bacini; le sue eventuali suddivisioni in sottounità andranno evidenziate mediante sigle. le differenze interne, date dalle variazioni laterali di facies, andranno rese mediante appositi sovrassegni. 22..22.. pprroobblleemmaattiicchhee iinn ccoorrssoo ddii ddiissccuussssiioonnee l’unità postglaciale viene trattata in modo specifico a seconda che si operi in ambito alpino o in ambito di pianura; appare evidente come in questi due diversi contesti l’upg abbia necessariamente età differenti. relativamente all ’ambito della pianura, l ’unità postglaciale comprende tutti i depositi di natura prevalentemente fluviale (ma anche lacustri/palustri) più recenti dei depositi fluviali/fluvioglaciali appartenenti ad unità associate allo lgm (vedi figura 1). all’interno di questi possono esser fatte distinzioni, con valenza locale (vedi il significato di sopra). per depositi legati ad eventi significativi, oppure sulla base di evidenze archeologiche o di datazioni, possono essere create delle sottounità assegnando a queste nomi locali. l’utilizzo dell’unità postglaciale pone problemi di logica in tutti quegli ambiti vallivi corrispondenti ad aree non glacializzate. in questi contesti, in assenza di depositi periglaciali correlabili con lo lgm, i depositi cartografabili nell’upg sono quelli che evidenziano rapporti con l’attuale sistema morfoclimatico o per i quali vi siano elementi di datazione numerica o relativa che consentano di differenziarli da quelli più antichi. per la cartografia di questi ultimi si rinvia al § 3.2. 33.. pprree llaasstt ggllaacciiaall mmaaxxiimmuumm pprree llaasstt ggllaacciiaall mmaaxxiimmuumm (pre lgm) indica l’insieme degli eventi che precedono l'ultimo massimo glaciale locale (lgm). i depositi ed unità riferibili al pre – lgm comprendono tutti i depositi legati ad eventi sedimentari precedenti lo lgm. come già visto per i depositi associati allo lgm, il loro studio e cartografia deve avvenire secondo una logica bacinale. inoltre, nello studio di tali depositi, occorre distinguere fra depositi glaciali (o comunque in chiara relazione con un evento glaciale) e depositi non glacigenici, in quanto cambia il a. bini et al. 79 modo in cui vengono inquadrati dal punto di vista stratigrafico e dunque cartografati. 33..11.. ddeeppoossiittii ggllaacciiggeenniiccii iinn aarreeee ddii aannffiitteeaattrroo nelle aree di anfiteatro l’identificazione e la cartografia dei depositi legati agli eventi sedimentari precedenti lo lgm sono attuabili senza problemi particolari. infatti, in questo contesto, caratterizzato da ampie superfici per la deposizione dei sedimenti e da limitata attività erosiva, i depositi sono solitamente ben conservati, permettendo il riconoscimento di diverse unità sulla base sia dei rapporti geometrici sia dei caratteri delle superfici limite superiori (morfologia, presenza di coltri eoliche, alterazione, ecc.). le differenze di caratteri consentono non solo la distinzione dei depositi riferibili allo lgm da quelli precedenti, ma anche il riconoscimento di vari sintemi /alloformazioni derivanti dagli episodi glaciali ad esso precedenti (vedi figura 2). possono però presentarsi casi in cui, pur in presenza di una successione di corpi sedimentari riconoscibili su base morfologica (es. morene e rispettive piane glaciali), non si riesca a distinguerli sulla base dei caratteri oggettivi della superficie limite superiore. in mancanza di tali dati non si riesce ad operare alcuna suddivisione in sintemi/alloformazioni, benché tali corpi siano dovuti ad eventi deposizionali diversi. tuttavia, in questi casi, è possibile istituire localmente delle unità informali (es. unità di…) per poi comprenderle tutte all’interno di un supersintema/allogruppo (vedi figura 2). 33..22.. ddeeppoossiittii ggllaacciiggeenniiccii ddeeggllii aassssii vvaalllliivvii in ambito vallivo e nelle valli tributarie dell’anfiteatro il discorso è più complesso in quanto subentrano due fattori assenti negli anfiteatri. “innanzitutto i sedimenti deposti durante i vari episodi glaciali occupano vaste aree negli apparati, dove i limiti delle massime espansioni raggiunte durante i vari episodi glaciali sono distanziati anche di parecchi chilometri, mentre sui versanti delle valli che afferiscono agli apparati, gli stessi sedimenti occupano aree limitate racchiuse in un piccolo intervallo di quote (spesso poche decine di metri). ossia a grandi variazioni frontali dei ghiacciai negli apparati corrispondono piccole variazioni in quota nelle valli. in secondo luogo sui versanti delle valli l'erosione è molto più intensa e quindi i depositi più antichi sono conservati solo come massi erratici isolati e/o piccoli lembi in luoghi più riparati” (bini et al., 2001). le esperienze di rilevamento hanno evidenziato come nell’ambito vallivo sia sempre riconoscibile l'unità associata allo lgm; inoltre nel tratto inferiore delle valli, a ridosso degli anfiteatri, sono spesso riconoscibili anche la/le unità più antiche relative alle glaciazioni precedenti lo lgm. ma al di fuori di questo limitato ambito, i depositi di ambiente glacigenico precedenti lo lgm si presentano frammentari e oggettivamente non più riconducibili alle unità riconosciute in anfiteatro. per semplificare e risolvere i problemi di cartografia, le esperienze maturate hanno portato a riunire i depositi precedenti lo lgm in un unico supersintema/allogruppo per ogni bacino (es. supersintema di xxx, bacino yyy). ovviamente tale supersintema/allogruppo cessa di esistere passando dall’ambito vallivo a quello dell’anfiteatro (vedi figura 2). dall’utilizzo di questo approccio, tenendo conto che le ubsu sono indipendenti dal concetto di tempo, consegue che l'intervallo temporale rappresentato dai depositi del supersintema/allogruppo vallivo include almeno gli intervalli temporali relativi ai depositi pre lgm compresi nei singoli sintemi/supersintemi dell'anfiteatro, ma non ne costituisce il raggruppamento a rango superiore. il supersintema/allogruppo dei depositi pre-lgm può venire cartografato in modo indistinto (cfr. 4c), oppure si possono riconoscere localmente corpi in successione stratigrafica o importanti per estensione: in questi casi vengono distinte ed istituite unità informali nell'ambito di quel dato supersintema/allogruppo (vedi figura 2). è opportuno sottolineare come tali unità non abbiano il valore di sintemi/alloformazioni (legati ad un singolo evento sedimentario valido a livello bacinale) ma di unità con significato strettamente locale, inglobanti sedimenti quasi sicuramente compresi in uno dei tanti sintemi/alloformazioni (oppure subsintemi/allomembri) presenti in anfiteatro, senza però potere definire univocamente a quali riferirle. 33..33.. ddeeppoossiittii nnoonn ggllaacciiggeenniiccii si tratta generalmente di depositi fluviali, di versante e di frana, talora cementati, ma anche depositi colluviali e, raramente, depositi lacustri. nel complesso si tratta di depositi slegati dalle vicende glaciali o, in ogni caso, non direttamente riconducibili ad esse. questi depositi possono essere cartografati all’interno di un gruppo (unità litostratigrafica), creato ad hoc in ogni bacino e che può essere suddiviso in unità formali (cfr. 4a) (es. formazioni) per corpi estesi e significativi, espressione di eventi sedimentari singoli, ma sempre di valore locale. per singoli affioramenti di piccola estensione è meglio usare il gruppo a livello indistinto. relativamente ai soli depositi cementati, solitamente poco estesi ed appartenenti a più episodi sedimentari, per rimarcarne il significato geologico, può essere conveniente cartografarli in un gruppo a sé stante, invece di istituire delle unità informali all’interno di un unico gruppo che racchiuda tanto i depositi cementati quanto quelli sciolti. l’approccio appena descritto può essere utilizzato anche nelle valli non glacializzate. ogni supersintema/allogruppo o gruppo dovrebbe essere rappresentato cartograficamente mediante l’utilizzo di uno specifico colore diverso da bacino a bacino; le sue eventuali suddivisioni in unità andranno evidenziate mediante sigle. le differenze interne, date dalle variazioni laterali di facies, andranno rese mediante appositi sovrassegni, laddove l’unità non sia indifferenziata (cfr. 4d). 44.. ssiiggnniiffiiccaattii ddeellllaa tteerrmmiinnoollooggiiaa uuttiilliizzzzaattaa a) unità formale/informale: termine relativo ai codici di stratigrafia. una unità formale risponde appieno alle definizioni dei codici; una unità informale non risponde pienamente a tali definizioni. b) unità formalizzata/non formalizzata: una unità formalizzata risponde appieno alle definizioni dei codici ed è stata validata dalla definizione di alcuni termini ... 80 a. bini et al. commissione italiana di stratigrafia. una unità non formalizzata è una unità formale non ancora formalizzata. c) indistinta/o: unità (di qualsiasi rango) non suddivisa in sottounità (es. gruppo non suddiviso in formazioni); rappresenta quindi una non divisione rispetto al tempo ed ai rapporti stratigrafici. d) indifferenziata/o: unità (di qualsiasi rango) non suddivisa al suo interno sulla base delle facies in essa presenti. e) ubiquitaria/o: unità (di qualsiasi rango) non distinta sulla base del bacino di appartenenza. 55.. ccoonncclluussiioonnii nel rilevamento dei depositi quaternari continentali in ambito alpino l’approccio alle tematiche esposte (come pure le di classificazione dei depositi in unità) dipendono dal contesto geologico in cui si lavora; le soluzioni cartografiche che possono essere adottate possono variare in funzione della scala della rappresentazione cartografica e delle possibilità grafiche che si hanno a disposizione. pertanto, il presente documento non vuole imporre soluzioni predefinite o vincolanti, ma fare chiarezza sul significato dei termini, in modo che 81 fig. 2 stralcio semplificato della carta geologia d5a4 “passirano” – scala 1:10.000 (regione lombardia, direzione generale territorio ed urbanistica, 2001). dati derivanti dai rilevamenti eseguiti per il progetto carg regione lombardia, in convenzione con il servizio geologico nazionale. la carta mostra il quadrante ne dell’anfiteatro morenico di franciacorta; tale area presenta sia le problematiche tipiche degli anfiteatri sia quelle degli assi vallivi, in quanto è bordata sul suo lato nne da rilievi montuosi con i quali, nel corso del quaternario, ha interagito il ghiacciaio vallivo camuno al suo sbocco in pianura. per questo motivo sono presenti sia le unità pre – lgm proprie dell’anfiteatro (in questa area sono: il supersintema di monterotondo rroott ed il sintema di monte pianeppii11)) sia le unità pre – lgm dell’asse vallivo (supersintema di monte alto aalloo). nell’area affiorano inoltre i depositi associati allo llggmm (sintema di iseo iiss) e quelli ad esso successivi (unità postglaciale ppgg). la distinzione fra le diverse facies dei depositi in un dato sintema è resa mediante un apposito sovrassegno, mentre colore e sigla del sistema rimangono invariati. osservazioni: 1. depositi glaciali dell’llggmm bordano le torbiere (lliimmiittee llggmm), mentre i suoi depositi fluvioglaciali fuoriescono dalla cerchia morenica lungo il paloeoalveo del t. longherone. tutti i depositi riferibili allo lgm sono stati cartografati come sintema di iseo. 2. nell’area di anfiteatro, all’esterno del sintema di iseo, affiorano le unità pre – lgm che sono state cartografate sia come sintemi (sintema di monte piane) sia come supersintemi (supersintema di monterotondo). quest’ultimo è stato localmente suddiviso in unità informali (dalla più interna alla più esterna, rispettivamente: unità di timoline rti, unità di borgonato rbo e unità di torbiato rto); allo stato attuale delle conoscenze non è possibile stabilire se queste unità corrispondano a pulsazioni di una stessa glaciazione o appartengano a distinti eventi glaciali. dove non è stato possibile operare tale suddivisione, si è cartografato il supersintema come indistinto (rroott). 3. nel settore ne dell’area, dove sono presenti i rilievi in substrato, in posizione esterna al sintema di monte piane si è cartografato il supersintema di monte alto, proprio dell’asse vallivo. tale scelta deriva dal fatto che non è stato possibile correlare i depositi presenti con le unità dell’anfiteatro s.s. anche in questo caso il supersintema è stato localmente suddiviso in unità di significato locale (unità di san pietro in lamosa – ala; unità di madonna del corno – ama; unità di pian delle viti – avi). dove non è stato possibile operare tale suddivisione si è cartografato il supersintema come indistinto (aalloo). 4. all’estremo n dell’area, subito ad e del supersintema di monte alto, è visibile un piccolo lembo del sintema di monte piane che prosegue verso n (per poche centinaia di metri), ormai in area valliva s.s. immediatamente dopo l’unità perde la sua evidenza sia morfologica che dei caratteri della superficie limite superiore. i depositi presenti sono stati fatti rientrare nel supersintema vallivo, data l’impossibilità di riferirli con sicurezza ad una delle unità dell’anfiteatro. simplified sketch from the geological map d5a4 “passirano” at the 1:10.000 scale (regione lombardia, direzione generale territorio ed urbanistica, 2001) derived from surveys made within the "progetto carg regione lombardia" in collaboration with the national geological survey. the map shows the ne part of the franciacorta glacial amphitheatre, where both amphitheatre and valley problems occur, because on the nne side the amphitheatre is bounded by mountain ridges that, during quaternary times, interacted with the val camonica glacier. because of this, within the area are present both pre – lgm amphitheatre units (monterotondo supersyntheme: rroott and monte piane syntheme: ppii11)) and pre – lgm valley units (monte alto supersyntheme: aalloo). furthermore lgm (iseo syntheme:iss) and post-glacial (unità postglaciale ppgg) are presents. the distinction between different facies within a certain syntheme is graphically visualized by an overmark, while colour and syntheme initials remain unchanged. some details: 1. the lgm glacial deposits surround the peat-mosses (lgm boundary), while their fluvioglacial counterparts spread out from the terminal moraine ridge along the longherone paleoriver-bed. all the deposits referred to the lgm were mapped as iseo syntheme. 2. in the amphitheatre, outer from the iseo syntheme, outcrop the pre – lgm units that were mapped both as syntheme (monte piane syntheme) and supersyntheme (monterotondo supersyntheme). the latter was locally subdivided into three informal units (respectively: unità di timoline rti, unità di borgonato rbo e and unità di torbiato rto). at the present state of knowledge it is not clear whether these units correspond to several pulses within the same glaciation or if they represent distinct glacial events. in the areas where it was impossible to distinguish these units the supersyntheme was mapped as indistinct (rroott). 3. in the ne part, where bedrock outcrops, in outer position with respect to monte piane syntheme, the monte alto supersyntheme is mapped within the axial part of the valley. this is due to the impossibility to correlate these deposits with the amphitheatre units. also in this case the supersyntheme was subdivided in local informal units (unità di san pietro in lamosa: ala; unità di madonna del corno: ama; unità di pian delle viti: avi). where it was impossible to distinguish these units the supersyntheme was mapped as indistinct (aalloo). 4. at the far north, just e from monte alto supersyntheme, we can notice a little outcrop of monte piane syntheme which continues northwards for few hundred meters within the valley. far north the unit looses both morphological evidence and the characteristics of the upper bounding discontinuity. because of the impossibility to unambiguously relate these deposits to a amphitheatre units, they were mapped within the valley supersyntheme. ➧ definizione di alcuni termini ... chi li utilizza o li affronta abbia un quadro di riferimento il più possibile chiaro ed univoco. inoltre alcune problematiche affrontate sono ancora in corso di verifica e confronto, e troveranno soluzione solo al termine dei lavori di rilevamento, quando si avrà a disposizione il quadro completo delle unità e si porterà a sintesi l’intero lavoro. e' necessario comunque precisare che il lavoro, in quanto frutto del confronto tra diversi autori con approcci metodologici differenti, rappresenta una piattaforma comune che non necessariamente riflette le idee espresse dai singoli autori in altri lavori pubblicati in precedenza. rriinnggrraazziiaammeennttii lavoro eseguito da componenti del “sottocomitato alpi gruppo di lavoro per il coordinamento del quaternario dei progetti carg dell’arco alpino”. si ringraziano tutte le persone che, a vario titolo, hanno offerto contribuiti utili ad approfondire gli aspetti delle problematiche sopraesposte, ed in particolare r. bersezio, g.b. castiglioni, v. maggi, g. orombelli, e c. ravazzi. bbiibblliiooggrraaffiiaa cciittaattaa:: bini a. (1997) problems and methodologies in the study of the quaternary deposits of the southern side of the alps. geologia insubrica, 22 ((22)). bini a., bosi c., carraro f. & orombelli g. (1989) rapporto novembre 1989. -commissione italiana di stratigrafia, gruppo di lavoro sul quaternario. bini a. e pellegrini a. (1998) geologia del quaternario. geologia insubrica, vol. 33 ((22)). bini a., felber m, pomicino n. & zuccoli l. (2001) geologia del mendrisiotto (canton ticino, svizzera): messiniano, pliocene e quaternario. berichte des bundesamt fur wasser und geologie, 11, 459 pp. crowley t.j. & north g.r., (1991) paleoclimatology. oxford university press, new york, 339 pp. international stratigraphic guide (1994). north american commission on stratigraphic nomencalture (1983) north american stratygraphic code. american association of petroleum geologist bullettin, 6677 (5): 841-875. penck a. & brückner e. (1909) die alpen im esizeitalter. leipzig, bd. 3. servizio geologico nazionale (2001) indicazioni per il r i levamento del quaternario continentale. documento interno sgn, 2001. s̆ibrava v., bowen d.q. & richmond g.m. (1986) quaternary glaciations in the northern hemisphere. report igcp n° 2244, quat. sc. rev., 5(1-4). 82 ms. ricevuto il 9 gennaio 2004 testo definitivo ricevuto il 9 febbraio 2004 ms. received: january 9, 2004 final text received: february 9, 2004 a. bini et al. imp.savelli& la città di forum sempronii e i suoi rapporti con il paesaggio attuale: una discussione basata su evidenze geologico-geomorfologiche e archeologiche daniele savelli1, mario luni2 & oscar mei2 1istituto di geologia, università degli studi “carlo bo”, campus scientifico, loc. crocicchia, 61029 urbino d.savelli@uniurb.it 2istituto di archeologia e storia dell’arte antica “sandro stucchi”, università degli studi “carlo bo”, via del balestriere, n. 2, 61029 urbino – m.luni@uniurb.it riassunto: savelli d., luni m. & mei o., la città di forum sempronii e i suoi rapporti con il paesaggio attuale: una discussione basata su evidenze geologico-geomorfologiche e archeologiche. (it issn 0394-3356, 2004). forum sempronii sorgeva su un vasto terrazzo del metauro a una distanza variabile da 200 a 700 m ca. dall’attuale alveo. sui lati meridionale e occidentale le mura correvano sul ciglio delle scarpate del terrazzo stesso, mentre sul lato settentrionale correvano alla base del versante collinare; più problematica la posizione sul lato orientale, non corrispondente ad alcun elemento dell’attuale fisiografia. alcuni caratteri geomorfologici e depositi recenti mettono in evidenza modificazioni minori, ma importanti, e permettono un tentativo di ricostruzione dell’assetto fisiografico del locale paesaggio in epoca romana. in particolare, due erano gli elementi principali che caratterizzavano il paesaggio in questo periodo: 1. il fiume verosimilmente scorreva sul lato sud a ridosso della cinta muraria, come è testimoniato da un vasto meandro abbandonato, con forme freschissime e depositi contenenti frammenti di terrecotte elaborati dall’azione fluviale all’ingresso del meandro. 2. il lato orientale era con tutta probabilità bordato da un fosso oggi quasi interamente colmato e del quale restano tuttora la sola porzione iniziale, sul versante, e terminale, sulla scarpata del paleomeandro. tale configurazione permetterebbe di superare alcune apparenti incongruenze fra l’attuale paesaggio e le primarie necessità sia difensive che di approvvigionamento idrico e di viabilità dell’insediamento romano. abstract: savelli d., luni m. & mei o., the town of forum sempronii and its relations with the contemporary landscape: a discussion based on geologic, geomorphologic and archaeological evidence. (it issn 0394-3356, 2004). the roman town of forum sempronii, founded between 132 and 126 b.c., is set near the modern village of san martino del piano, ca. 2 km to the east of fossombrone. the ancient settlement rests on the flat surface of a wide upper-pleistocene terrace of the metauro river, ca. 20 m above the modern stream. at least three sides of the roman town walls took advantage of geomorphologic elements. indeed, they were against the foothill to the north; to the west they ran along the edge of a steep scarp on the left of fosso della conserva (a small left-tributary stream of the metauro river), and they rose southwards on the edge of the pleistocene terrace. the eastern side is more problematic as regards both its true position and its relation to some specific landform: in all probability it developed along the bank of a no longer recognisable gully. one of the most important features of the modern landscape in the vicinity of the archaeologic site is a roughly flat-bottomed, broad semicircular depression representing a pronounced relict meander of the metauro river. it is entrenched into the upper pleistocene terrace unit and bounded to the north by the terrace scarp on which the southern wall of the roman town was built. hence, the scarp enclosing the abandoned meander separates the upper-pleistocene terrace alluvium from the holocene one: it is well-preserved, with a sharp upper edge and scarce colluvium/debris accumulation at the toe. furthermore, the abandoned metauro river channel is still well recognisable along almost all the scarp toe. the excellent preservation of such landforms hints at quite a recent cut-off of the meander neck and abandonment of the previous course. moreover, the very occurrence of rounded roman bricks and tiles in alluvial deposits at the mouth of the abandoned meander hints at a recent fluvial activity on at least a sector of the relict fluvial bend. finally, maps dating back to 16th –18th century show that the meander at issue was already inactive and only minor adjustments of the fluvial course did occur at its mouth. on the basis of these considerations, and since important modifications of fluvial-channel patterns in nearby areas can be ascribed to late roman-early medieval times, we can speculate that the “roman” metauro river flowed through the abandoned meander of today, close to the southern walls of the town. the presence of a large fluvial channel just close to the town walls would have enhanced their defensive effectiveness. indeed, its vicinity to the river would have made the southern side of the town the more defensible one as well as a preferential way for watering. moreover, the presence of an active channel at the foot of the scarp would have been able both to improve gully development and to sustain existing gullies free from debris-filling, thus allowing ditches similar to the one which has been hypothesized to border the eastern wall of the town to be sustained. on the contrary, the meander cut-off and the abandonment of the previous river course would have been able both to enhance the filling-up of such gullies and to accelerate their extinction. parole chiave: : modificazioni fluviali, geo-archeologia, forum sempronii, fiume metauro. keywords: fluvial modifications, geo-archaelogy, forum sempronii, metauro river. il quaternario italian journal of quaternary sciences 17(2/1), 2004, 185-193 1. premessa le relazioni dell’uomo con l’ambiente nei suoi vari aspetti e con l’ambiente "geomorfologico" (sensu panizza, 1992, pag. 344) in particolare, sono sempre legate da stretti vincoli di reciprocità e interdipendenza. infatti, in accordo con mansuelli et al. (1957, p. 200) “la capacità selettiva dell’uomo riconosce nell’ambiente in cui si svolge la vita i fattori preferenziali per stabilire la propria sede: clima, possibilità di rifornimenti, sicurezza”. proprio il concorrere di tutti questi fattori va a costituire il cosiddetto optimum ecologico. in tale contesto i fiumi, in quanto vie naturali, oltre che luoghi ricchi d’acqua, hanno costituito i primi assi di sviluppo del 186 d. savelli, m. luni & o. mei popolamento umano. pertanto, la presenza di fiumi, insieme a quella di sorgenti, è sempre stato un elemento determinante per la scelta della località destinata a essere sede di un abitato, sicché è rarissimo il caso di abitati che ne siano lontani. inoltre, l’intrecciarsi di canali naturali spesso incassati fra aspre ripe d’erosione, isola settori di territorio che, oltre a mantenere i vantaggi della vicinanza al corso d’acqua, risultano difesi sia dall’irruenza distruttiva delle piene che da eventuali nemici. le trasformazioni del paesaggio, specie quello fluviale, avendo tempi e ritmi paragonabili con quelli dei cambiamenti storici e culturali (cfr. panizza & piacente, 2003, p.216), possono produrre interazioni e legami talora complessi che rendono necessario un approccio integrato sia per la comprensione degli eventi che per poter delineare i tratti evolutivi di un territorio. in particolare, le trasformazioni recenti e talora intense del territorio obliterano spesso i caratteri fisiografici originari, collocando apparentemente gli insediamenti al di fuori del loro contesto “naturale” e ponendo questioni sul perchè della scelta di ubicazioni apparentemente illogiche. nell’area nord-marchigiana, ne sono un esempio lo spostamento del foglia a pesaro (luni, 1995) e il forte avanzamento della linea di riva a fano (elmi et al., 1994; luni, 2000, pp. 75-77). altrettanto importante è la ricostruzione degli antichi paesaggi e della loro evoluzione al fine di dirimere questioni storiche particolari come ad esempio, nell’area considerata (savelli & nesci, 1994; nesci & savelli, 2002), la controversa questione dell’ubicazione della famosa battaglia del metauro (cfr. luni 2002 cum bibl.). anche forum sempronii mostra apparenti incongruenze fra paesaggio attuale e collocazione del nucleo insediativo o di parti di esso, ponendo l’accento su possibili modificazioni ambientali successive all’abbandono della città. in tale ambito, lo scopo della presente nota è quello di affrontare una discussione integrata di elementi geologico-geomorfologici e archeologici. l’obiettivo è infatti quello di fornire un contributo alla soluzione del problema della evoluzione recente del tratto della val metauro sul quale tale città sorgeva (fig. 1) e mettere in evidenza, in particolare, eventuali migrazioni fluviali o scomparsa di linee di drenaggi preesistenti. 2. elementi archeologici forum sempronii fu fondata, in un’area già frequentata in età preromana, tra 133 e 126 a.c., probabilmente in seguito all’intervento di caio sempronio gracco, la cui presenza nel territorio è documentata da un’iscrizione (cil, i2, 719) rinvenuta nel ‘700 a san cesareo, nella collina di monte giove, presso fano. il cosiddetto “cippo graccano” ricorda l’attività della commissione triumvirale nominata per l’applicazione della lex sempronia del 133 a.c., che portò a una riorganizzazione dell’ager publicus attraverso la divisione e la distribuzione del terreno in lotti (centuriazione). forum sempronii divenne municipium nel corso del i secolo a.c., fu ascritto alla tribù pollia ed è menzionato da strabone (v, 2, 10), plinio (naturalis historia, iii, 113) e tolomeo (ii i , 1, 46), oltre che dagli it ineraria . contraddistinta da una fiorente comunità cristiana già dalla fine del iv o agli inizi del v secolo d.c. e sede vescovile (vernarecci, 1903, pp. 97-116) la città subì gravi danni durante la guerra greco-gotica del 535-553 d.c. successivamente, la maggior parte degli abitanti si spostò su un vicino colle, più facilmente difendibile, originando così il centro di altura che si sviluppò in età medievale e rinascimentale col nome di fossombrone (v. fig. 1). la città originaria venne così quasi completamente abbandonata, ma il nuovo insediamento, pur con alcune modificazioni dovute al trascorrere dei secoli e al mutare della lingua, ne ereditò il nome (luni, 2001, p. 16). il sito dell’antico municipium fu localizzato fin dal xv secolo sulla vasta piana sulla quale sorge l’attuale frazione di san martino del piano, circa 2 km a est di fossombrone (fig. 1), in seguito ai rinvenimenti di manufatti che ripetutamente si verificavano nel corso dei lavori agricoli (vernarecci, 1903, pp. 30-34; mercando, 1983, pp. 83-84; gori & luni, 1983, pp. 9196). la presenza della via flaminia, aperta intorno al 220 a.c., oltre ad aver condizionato l’assetto viario della città, di cui andò a costituire il decumanus maximus, ha rappresentato anche la principale causa di sviluppo economico, almeno per i primi due secoli dell’impero. i limiti dell’area urbana, riconosciuti con sicurezza fig. 1 il tratto inferiore della valle del fiume metauro con l’ubicazione dell’area in studio. the lower metauro river valley and location of the study area. su tre lati, presentavano mura che sfruttavano elementi geomorfologici di notevole rilevanza (figg. 2, 3, 4): a nord si appoggiavano al piede del versante collinare, a ovest correvano lungo il ciglio della ripida scarpata incisa in sinistra idrografica dal fosso della conserva (modesto affluente di sinistra del metauro), a sud si ergevano sul ciglio della scarpata di un vasto terrazzo pleistocenico del metauro stesso. in particolare, in corrispondenza del fosso della conserva il montecchini (1879, p. 94) vide “dalle alte sponde, sporgere dal terreno le fondamenta squarciate di molti fabbricati, e la sezione di pavimenti delle stanze e del selciato delle strade..”, testimoniando così l’erosione delle sponde dovuta al regime torrentizio del corso d’acqua (gori & luni 1983, p. 93). il confine orientale, più problematico sia come ubicazione che come corrispondenza con particolari elementi morfologici, correva verosimilmente sul margine di un fosso attualmente non più riconoscibile. 187la città di forum sempronii ... sono state identificate necropoli di una certa consistenza sia a ovest, oltre il fosso della conserva, sia a est dell’abitato (fig. 2), con rinvenimenti di monumenti sepolcrali utili per delimitare l’estensione dell’antica area urbana. tombe “alla cappuccina” (con letto e copertura di tegole e pochi oggetti di corredo) di piena età romana sono state segnalate proprio sul settore più orientale della scarpata che delimita la città verso sudest (dato inedito, comunicazione orale del prof. g. gori). probabili tratti della cinta muraria sono attualmente visibili lungo il lato meridionale (fig. 2, n. 9), così come i resti di due torri quadrangolari in opus quadratum, inglobati nelle fondazioni di case coloniche (gori & luni, 1983, pp. 92 e 103, fig. 2, n. 16), mentre un tratto di mura in opus tumultuarium (risalente alla metà del vi secolo d.c., direttamente legato alle vicende della guerra greco-gotica) con torre circolare, è stato messo in luce proprio sul lato orientale (fig. 2, n. 11). sempre su fig. 2 pianta di forum sempronii: 1) edificio termale; 2-3) ambienti con impianti di riscaldamento a ipocausto; 4) ambiente con colonne; 5) domus con mosaici; 6) muri; 7) basolato della via flaminia; 8) probabile basilica civile; 9) mura urbiche; 10) trincea di scavo; 11) torre circolare, vi secolo d.c.; 12-17) villa rustica; 13) deposito di anfore; 14-15) resti di edificio; 16) torri quadrangolari in opus quadratum; 18) vie interne all’abitato. plan of forum sempronii: 1) baths; 2-3) rooms with heating system (hypocaust); 4) room with columns; 5) domus with mosaics; 6) walls; 7) via flaminia; 8) probable civil basilica; 9) city walls; 10) trench; 11) round tower, vith century a.d.; 12-17) villa rustica; 13) amphorae’s find; 14-15) building ruins; 16) quadrangular towers in opus quadratum; 18) town street. 188 questo versante strutture forse pertinenti a una porta urbica sono state messe in luce nel 1806 e poi ricoperte, nello stesso luogo in cui il 3 ottobre 1603 si rinvenne un’iscrizione menzionante la porta gallica (cil, xi, 6136; vernarecci 1903, pp. 34-35; gori & luni 1983, p. 103). l’abitato si presenta dunque esteso per circa 35 ettari, con impianto viario a scacchiera, caratterizzato da strade parallele e perpendicolari tra loro che si incrociano ad angolo retto (fig. 2). dal 1974 sono in corso scavi regolari da parte dell’ istituto di archeologia dell’università di urbino, che hanno permesso di individuare e mettere in luce un edificio termale, un tratto urbano della via consolare flaminia e tratti di altre vie interne all’abitato, rendendo così possibile il riconoscimento di almeno un intero quartiere di abitazione rettangolare (insula) di due actus per tre (ca. 70x105 m, luni, 2001, pp. 11-16; luni, 2003). un problema ancora insoluto per quanto concerne il percorso della cinta muraria è quello riguardante i limiti meridionale e orientale della città. a sud infatti le strutture difensive correvano lungo il “ciglio tattico” costituito dalla ripida scarpata attualmente distante da ca. 200 m a ca. 700 m dall’alveo attuale del fiume metauro. la vasta depressione semicircolare che qui si nota (figg. 3, 4) è una delle caratteristiche più salienti del locale paesaggio e, come verrà evidenziato meglio in seguito, è da collegarsi a un meandro abbandonato dal metauro in epoca abbastanza recente. questa particolare forma è stata discussa già dal vernarecci (1903, p. 78) il quale, affermando che in tale area “l’acqua, certo, vi sarà stata introdotta” rigetta tuttavia una precedente, suggestiva ipotesi del morosini, il quale, nelle parole del vernarecci stesso, vedendo l’area “così formata da potere accogliere parte dell’acqua del metauro e averne un lago artificiale per ludi e per pugne navali, immaginò che ivi a’ tempi romani fosse una naumachia”. 3. aspetti geologici e geomorfologici la città romana sorge sulla superficie di un vasto terrazzo della valle del fiume metauro (fig. 3), circa 20 m al di sopra dell’attuale alveo. sui lati sud-occidentale e sud-orientale il perimetro della città coincide con il bordo di scarpate fluviali/fluvio-torrentizie, mentre sul lato nord-occidentale corre alla base del versante di sinistra della valle. il lato nord-orientale attraversa invece la superficie pianeggiante del terrazzo senza alcuna fig. 3 schema geomorfologico e distribuzione dei depositi continentali quaternari nel territorio di forum sempronii. geomorphologic sketch and distribution of quaternary continental deposits in the forum sempronii area. d. savelli, m. luni & o. mei 189 correlazione con elementi dell’attuale fisiografia. l’attuale metauro scorre in direzione circa e-w (fig. 3), allontanandosi progressivamente dalla scarpata fluviale che segna il margine sud-orientale della città, a orientazione circa sw-ne. la città poggia su alluvioni terrazzate prevalentemente ghiaiose (figg. 1, 3, 4), ben correlabili su base morfostratigrafica al "3° ordine" (e.g. savelli et al., 1984; nesci & savelli 1991a, 1991b) dei terrazzi della letteratura tradizionale. tale attribuzione è supportata anche da alcune date (radiocarbonio) relative ad aree non lontane dal sito considerato (alessio et al., 1987; calderoni et al., 1994) che, seppure ante quem, permettono comunque di inserire l’unità esaminata nel quadro delle fasi di terrazzamento note per i fiumi marchigiani (cfr. nesci et al., 1995) e riferirne i depositi al pleistocene superiore. alle spalle della scarpata principale, la superficie del terrazzo pleistocenico è stata rimodellata in modo più o meno intenso dal metauro (fig. 3), come sottolineano (cfr. savelli et al., 1984; nesci & savelli 1991a) sia la blanda inclinazione della superficie del terrazzo verso l’attuale alveo, sia varie scarpate minori e/o semplici rotture di pendio spesso associate a tracce di alvei relitti sinuoso-meandranti. come è logico aspettarsi, le tracce in superficie dei paleoalvei si interrompono all’altezza della città romana, fornendo così un elemento morfologico aggiuntivo, utile alla perimetrazione dell’area archeologica. la scarpata del terrazzo principale è costituita in certi punti da sole alluvioni, in altri alla sommità da alluvione e al piede da roccia in posto. queste differenze, dovute all’irregolarità del substrato, caratterizzato da depressioni alternate a rilievi sepolti (cfr. nesci & savelli 1991a), si riflettono sullo spessore della coltre alluvionale, variabile da minimi di 5÷6 m (p. es. in corrispondenza dell’angolo sud-occidentale della città romana) a oltre 20 m (p. es. scarpate in sponda destra, di fronte alla città). verso sw il substrato roccioso, affiorante sia sulle scarpate dei terrazzi che sul versante collinare, è costituito dai termini pelitico-arenacei della formazione marnoso-arenacea (tortoniano superiore); nel settore centrale compare la formazione gessoso-solfifera (messiniano inferiore-medio), qui rappresentata da marne tripolacee con potenti banchi di calcare di base (cfr. savelli & wezel, 1978); verso ne affiorano facies prevalentemente argilloso-marnose della formazione a colombacci (messiniano superiore). fra l’orlo della scarpata principale e i terrazzi più recenti che coprono con una certa continuità il fondovalle, si riconosce una serie di terrazzi minori, di ampiezza piuttosto modesta (n. 6 in figg. 3, 4). questi, posti a quote di 12÷15 m sull’alveo attuale e corrispondenti ad accumuli alluvionali di 5÷7 m di spessore, ove presenti, interrompono la continuità morfologica della scarpata principale, segmentandola. le corrispondenti unità alluvionali, poggiano sia sulle rocce del substrato (a sw della città romana) che sulle ghiaie del pleistocene superiore e i loro spessori, relativamente consistenti, esprimono una fase di aggradazione minore che va a interrompere temporaneamente il progressivo approfondimento fluviale. questo evento, di difficile inquadramento cronologico, potrebbe riferirsi a un olocene relativamente antico o, addirittura, alla parte fig. 4 sezioni schematiche mostranti la morfologia dell’area esaminata e i rapporti fra i depositi continentali quaternari rappresentati in fig. 3. i numeri sono gli stessi di fig. 3. schematic profiles elucidating the morphology of the study area and the relations among the quaternary continental deposits represented on fig. 3. explanation of numbers on fig. 3. la città di forum sempronii ... 190 finale del pleistocene superiore. in entrambi i casi, tuttavia, la natura prevalentemente ghiaiosa dei depositi, piuttosto disorganizzati e con elementi anche molto grossolani, li rende difficilmente comparabili con i depositi fini che caratterizzano analoghe fasi minori di aggradazione in vari corsi d’acqua delle marche centromeridionali (cilla et al., 1996 cum bibl.). il margine sud-orientale della città corre sull’orlo della scarpata principale del terrazzo pleistocenico, interrotta da un lembo del terrazzo minore sopra descritto nella sua sola estremità sud-orientale. ai piedi della scarpata, a 5-8 m al di sopra dell’attuale alveo (ca. 15÷12 m al di sotto della piana pleistocenica), si apre un’ampia piana fluviale olocenica che descrive un ampio anfiteatro naturale (fig. 5). la presenza di un modesto rilievo che si erge nella porzione centro-meridionale di questa piana, conferisce alla stessa un aspetto in pianta a ferro di cavallo, troncato verso sud dall’attuale alveo del metauro (fig. 3). si tratta di un esempio particolarmente esplicativo di meandro abbandonato, la cui evoluzione ha condotto dapprima alla formazione di uno strettissimo collo in corrispondenza di alcuni banchi di calcare di base, particolarmente resistenti, poi al taglio del collo stesso, con conseguente abbandono dell’antico tracciato e isolamento di un “testimone” roccioso ricoperto da lembi alluvionali di varia età (figg. 3, 4). dal punto di vista morfologico, la piana corrispondente al meandro in oggetto si raccorda con una serie di terrazzi minori distribuiti sull’intero fondovalle dell’area esaminata a quote di 4÷8 m sull’alveo attivo e costituiti da corpi alluvionali molto sottili (2÷3 m) variamente sovrapposti o incastrati. questo particolare assetto (cfr. fig. 6), collegato a modestissime scarpate o semplici irregolarità osservabili sulla superficie dei depositi (fig. 3), testimonia complessi e ripetuti episodi di cut-and-fill e modeste, ma ripetute migrazioni laterali dell’alveo in tempi molto recenti. alcuni affioramenti sulla sponda di sinistra del metauro, in corrispondenza dell’imbocco del meandro abbandonato e affioramenti oggi non più visibili al suo sbocco, mostrano una significativa frequenza di frammenti di terracotta romana (mattoni e tegole) arrotondati dall’elaborazione fluviale e associati alle ghiaie fluviali embriciate (fig. 6.2). questo testimonia da un lato il rimaneggiamento di materiali provenienti da ville rustiche adiacenti all’antica città (depositi a monte) e forse dalla città stessa (depositi allo sbocco del meandro) e, dall’altro, una età da romana a post-romana di almeno una parte dei depositi. a cavallo dell’alveo attuale, si osservano infine depositi fluviali molto recenti, di età verosimilmente di poco anteriore agli anni ’50 (sulla base dei fotogrammi del volo gai 1955), sulla superficie dei quali abbondanti tracce di canali a indice di sinuosità relativamente basso si associano a meno frequenti resti di tracciati sinuoso-meandranti. 4. discussione e conclusioni la non corrispondenza fra importanti elementi dell’insediamento romano di forum sempronii e la fisiografia attuale del luogo pone vari interrogativi su eventuali modificazioni ambientali sopravvenute dopo l’abbandono della città. indiscutibilmente infatti, la perizia fig. 5 il meandro abbandonato con l’ubicazione della città romana. the abandoned meander and location of the roman town. d. savelli, m. luni & o. mei tecnica dei romani e la loro attenzione a ogni singolo elemento morfologico erano tali da ricavarne nella loro attività edilizia e, soprattutto, nelle opere di difesa il maggior utile possibile (adam 1990, cum bibl.). gli aspetti archeologici e quelli geologico-geomorfologici non sono tuttavia trattati congiuntamente da alcun studio interdisciplinare recente; la solo opera del vernarecci (1903, pp. 31-32), fornisce in nota lapidarie informazioni geologiche, dalle quali risulterebbe che “l’antica città era fabbricata su marne e ghiaie plioceniche”. in tale contesto, il confronto interdisciplinare fra i dati storico-archeologici e geologico-geomorfologici relativi all’area su cui sorge forum sempronii ci permette di delineare i caratteri morfoevolutivi del territorio. i dati ottenuti permettono anche di discutere e chiarire alcune problematiche relative ai legami fra l’antico insediamento e l’ambiente fisico del tempo e forniscono nuovi e stimolanti spunti di discussione e di indagine, come a seguito sintetizzato. 1. il tracciato del fiume metauro era con tutta probabilità differente dall’attuale: in particolare il fiume percorreva localmente un ampio meandro che, se attivo in epoca romana, avrebbe permesso alle acque di lambire il lato sud-orientale della città. il modestissimo dislivello rispetto all’attuale alveo e la freschezza delle forme legate al meandro abbandonato (scarpate poco rimodellate, depressione corrispondente al paleocanale ben preservata e scarsamente colmata, scarsità di detriti al piede nonostante le scarpate siano costituite da materiali degradabili) mettono in evidenza un abbandono piuttosto recente. l’abbandono, comunque, è senz’altro precedente al 16°-18° secolo, in quanto la documentazione disponibile mostra per tale periodo una situazione simile all’attuale. in particolare, la documentazione storica, testimonianze orali e le evidenze in foto area del volo gai del 1955 mettono in risalto una serie di oscillazioni minori, con parziale rioccupazione del tratto iniziale del meandro dal 18° secolo a tutta la prima metà del 19° secolo. una attività del canale in antico è avvalorata anche dalla distribuzione di resti archeologici, fra i quali le tombe di piena età romana osservabili in sezione sulla scarpata, ma non presenti sulla piana (prof. g. gori, comunicazione personale). in particolare, il parziale collasso di alcune tombe e l’abbondanza di frammenti di terrecotte, a luoghi blandamente smussati, lungo tutto il piede della scarpata, potrebbe indicare il proseguire di una accentuata erosione di sponda sul lato esterno del meandro anche in età relativamente tarda, forse anche con una blanda ridistribuzione verso valle dei materiali. conclusioni analoghe possono essere tratte dalle sottili sequenze alluvionali con ciottoli costituiti da tegole e mattoni di epoca romana osservabili sia all’imbocco del meandro estinto e documentate in figura 6, che allo sbocco dello stesso. inoltre, lo spessore di ca. 4÷5 m di alluvioni di età da presumibilmente romana a post-romana (cfr. fig. 6.1), evidenzia uno “svuotamento” almeno parziale del solco del meandro abbandonato durante le fasi di vita della città. l’attività del meandro in epoca romana, non è in disaccordo con quanto noto in letteratura per l’evoluzione recente dei tratti medio-bassi delle valli marchigiane. infatti, in queste aree, i tracciati meandranti, che caratterizzano la reincisione dei depositi alluvionali del pleistocene superiore (cfr. nesci & savelli, 1986; nesci et al., 1995 cum bibl.; coltorti, 1991 e 1997 cum bibl.) persistettero verosimilmente fin dopo l’epoca romana, dopo di che vennero soppiantati da canali intrecciati a causa soprattutto di una incisiva azione antropica che produsse una sensibile deforestazione con conseguente incremento dell’erosione del suolo (coltorti, 1997). a prescindere da questi elementi, la datazione della fase di attività e di abbandono del meandro al momento resta tuttavia non meglio precisabile. dal punto di vista archeologico, va infine rimarcato che la presenza di un canale fluviale attivo a ridosso delle mura avrebbe accresciuto notevolmente l’efficacia delle stesse, rendendo il lato sud della città quello meglio difendibile e avrebbe altresì facilitato l’approvvigionamento idrico. 2. il lato sud-occidentale della città correva lungo il ciglio della ripa d’erosione torrentizia che costituisce il fianco di sinistra del fosso della conserva. quest’ultimo è rimasto pressochè invariato; solo alcune strette incavature nella scarpata (elemento peraltro comune con la 191 fig. 6 le alluvioni all’imbocco del meandro abbandonato. 1 = veduta d’insieme mostrante le unità contenenti: a) sporadici frammenti arrotondati di terrecotte (deposito di età romana?); b) abbondanti frammenti arrotondati di tegole e mattoni romani (fase alto-medievale?); c) materiali non anteriori al 20° secolo; d) materiali degli anni ’50-‘60. 2 = particolare dell’intervallo b): la freccia indica un frammento di terracotta romana arrotondata dall’elaborazione fluviale. recent alluvium in the upstream termination of the abandoned meander. 1 = overall view displaying the units containing: a) rare rounded brick fragments (roman times?); b) abundant rounded roman brick/tile fragments (early medieval times?); materials not older than 20th century; c) remnants of years 1950-1960. 2 = detail of the unit b): the arrow indicates a fragment of roman brick rounded by river reworking. la città di forum sempronii ... scarpata fluviale sulla quale corre il lato sud-occidentale delle mura) possono indicare piccoli franamenti locali forse successivi all’abbandono della città, a luoghi connessi anche con l’erosione di sponda in corrispondenza di anse del ruscello (cfr. gori & luni 1983, p. 93). 3. il lato nord-orientale della città era con tutta probabilità bordato da un fosso oggi quasi interamente colmato. l’esatta posizione delle mura su questo lato è tuttora incerta: esse, infatti, attraversavano qui la superficie del terrazzo pleistocenico oggi completamente pianeggiante e privo di particolari elementi morfologici di riferimento, nè i dati archeologici permettono un preciso posizionamento. l’attenzione posta dai romani allo sfruttare elementi fisiografici e la necessità di una adeguata difendibilità, inducono comunque ipotizzare presenza di un antico fosso adiacente a questa porzione della cinta muraria. alcune evidenze geomorfologiche permettono di avvalorare questa tesi. alcuni fossi parzialmente colmati segmentano la porzione settentrionale della scarpata che circonda il meandro abbandonato (fig. 3). il più occidentale di essi cade circa sul prolungamento del confine nord-orientale della città. l’avvallamento si presenta oggi relativamente ampio e arrotondato a causa di un consistente riempimento detritico; il canale attuale è rappresentato da un piccolo fosso vistosamente rettificato e arginato, solo occasionalmente percorso da acque di precipitazione. tuttavia, questa situazione potrebbe essere ben diversa da quella che si poteva riscontrare quando il suo sbocco era lambito dal canale fluviale. in questa fase il fiume poteva agevolmente caricarsi degli apporti prevalentemente limoso-sabbiosi di questo minuscolo tributario, mantenendone sgombro sia lo sbocco che il tratto terminale. in più l’erosione di sponda, arretrando lo sbocco del fosso e abbreviando gradatamente il suo tratto terminale, avrebbe contribuito al mantenimento dei gradienti e favorito il perdurare di una efficace rimozione dei detriti lungo il fosso stesso. sul versante collinare retrostante, sempre sul prolungamento del margine nord-orientale della città, si osserva una piccola valle a orientazione nw-se, sede di ampi fenomeni franosi in parte attivi (fig. 3). la valle è oggi percorsa da un corso d’acqua a regime occasionale che, al suo sbocco sul terrazzo pleistocenico, ha prodotto una zona di accumulo relativamente vasta. l’irregolarità della superficie dovuta a modificazioni antropiche più o meno recenti e, forse, al seppellimento e/o aggiramento di antiche strutture murarie (legate alla necropoli), rendono poco chiara la forma di accumulo naturale, anche se questa è almeno in parte interpretabile come conoide, coalescente sui lati con l’ampia fascia colluviale che verso sw ricopre in parte anche le rovine romane. il segmento terminale del corso d’acqua, che appare regimato e deviato artificialmente verso est, termina oggi al margine della conoide, in direzione di una vallecola che incide la scarpata del terrazzo pleistocenico molto più a valle della città romana. nonostante sia quello principale, questo non è il solo canale presente nel luogo: un altro, più piccolo è tuttora osservabile circa 250 m più a ovest, proprio in corrispondenza di una torre recentemente portata alla luce e riferibile al vi secolo d. c. (fig. 2, n. 11). il canale attuale, fortemente rettificato dall’azione antropica, termina oggi al piede del versante collinare. le mappe catastali della prima metà del ‘900 ne mostrano tuttavia la prosecuzione, attraverso una canalizzazione artificiale con vari gomiti all’interno della città romana, almeno sino all’attuale strada statale. a prescindere da quest’ultimo tratto, il cui andamento può essere il risultato di deviazioni artificiali relativamente recenti, risulta invece piuttosto interessante il segmento iniziale. questo (fig. 3) è stretto fra accumuli di frana in parte tuttora attivi e proprio i vari movimenti franosi possono, con l’andar del tempo, aver occluso una vallecola più lunga e profonda dell’attuale. in definitiva, sul prolungamento verso monte del margine nord-orientale della città, esiste oggi una valle contenente almeno due canali “ciechi”, che in passato potevano raccordarsi con quello osservato sulla scarpata del meandro abbandonato e sopra descritto. non è da escludere che proprio il minore, anche se oggi quasi irriconoscibile, potesse percorrere il lato esterno della cinta muraria collegandosi all’alveo del metauro e costituire un elemento naturale che, seppur modesto, potesse essere sfruttato per delimitare il perimetro abitativo. ringraziamenti gli autori desiderano ringraziare il prof. giancarlo gori, ispettore onorario della soprintendenza archeologica delle marche per la zona di fossombrone, per le proficue discussioni e le utili informazioni riguardanti dati ancora inediti, e la biblioteca passionei di fossombrone, nella persona della dott.ssa antonella cesarini, per la sempre continua disponibilità dimostrata durante la ricerca. lavori citati adam j. p. (1990) l’arte di costruire presso i romani. longanesi, milano, 367 pp. alessio m., allegri l., azzi c., calderoni g., cortesi c., improta s., nesci o., petrone v. & savelli d. (1987) successioni alluvionali terrazzate nel medio bacino del metauro (appennino marchigiano) datazione con il 14c. geogr. fis. dinam. quat., 10, pp. 307-312. calderoni g., nesci o., savelli d. & pergolini c. (1994) last-glacial terrace alluvium in the metauro river basin: new radiometric dates for the beginning of the aggradation stage. il quaternario, 7, pp. 607611. cilla g., coltorti m., dramis f., farabollini p., gentili b. & pambianchi g. (1996) fluvial sedimentation during the early holocene in the marchean valleys (central italy). il quaternario, 9 (2), pp. 459-464. coltorti m. (1991) modificazioni morfologiche oloceniche nelle piane alluvionali marchigiane: alcuni esempi nei fiumi misa, cesano e musone. geogr. fis. dinam. quat., 14, pp. 73-86. coltorti m. (1997) human impact in the holocene fluvial and coastal evolution of the marche region, central italy. catena, 30, pp. 311-335. elmi c., fanucci f., nesci o., beer p. & pignocchi a. (1994) evoluzione della linea di riva dal f. reno al f. potenza (italia centrale). il quaternario, 7(1), pp. 305-310. gori g. & luni m. (1983) note di archeologia e topografia forosemproniense. picus, 3, pp. 87-113. 192 d. savelli, m. luni & o. mei luni m. (1995) topografia storica di pisaurum e del territorio. in: aa.vv., “pesaro nell’antichità”, marsilio, venezia, pp. 85-139. luni m. (2000) studi su fanum fortunae. quattroventi, urbino, 321 pp. luni m. (2001) statue di bronzo a forum sempronii e in città del versante medio adriatico, in luni m. & gori g. (eds.), “i bronzi di forum sempronii”, quattroventi, urbino, pp. 11-67. luni m. (2002) la battaglia del metauro: tradizione e studi. quaderni di archeologia delle marche, 11, 259 pp. luni m. (2003) forum sempronii–fossombrone. in: luni m. (ed.), “archeologia nelle marche. dalla preistoria all’età tardoantica”. nardini, firenze, pp. 190-192. mansuelli g.a., alfieri n., castagnoli f. (1957) geografia e topografia storica. enciclopedia classica, sez. iii, x (iv), sei, torino, pp. 185-307. mercando l. (1983) documenti d’archivio per forum sempronii. bollettino d’arte, 19, pp. 83-110. montecchini p. (1879) la strada flaminia detta del furlo e i luoghi da essa attraversati nel tratto da ponte voragine alla città di fano, pesaro, 143 pp. nesci o. & savelli d. (1986) cicli continentali tardoquaternari lungo i tratti vallivi mediani delle marche settentrionali. geogr. fis. dinam. quat., 9, pp. 192-211. nesci o. & savelli d. (1991a) lineamenti geomorfologici del terrazzo fluviale del "3° ordine" del bacino del metauro (marche settentrionali). geogr. fis. dinam. quat., 14, pp. 141-148. nesci o. & savelli d. (1991b) successioni alluvionali terrazzate nell'appennino nord-marchigiano. geogr. fis. dinam. quat., 14, pp. 149-162. nesci o. & savelli d. (2002) geomorfologia della piana del fiume metauro. in: luni m. (ed.), “la battaglia del metauro: tradizione e studi”, quaderni di archeologia delle marche, 11, pp. 11-20. nesci o., savelli d., calderoni g., elmi c. & veneri f. (1995) le antiche piane di fondovalle nell’appennino nord-marchigiano. in: castiglioni g. b. & federici p. r. (eds.), “assetto fisico e problemi ambientali delle pianure ialiane”; mem. soc. geogr. it., 53, pp. 293-312. panizza m. (1992) geomorfologia pitagora, bologna, 397 pp. panizza m. & piacente s. (2003) geomorfologia culturale pitagora, bologna, 350 pp. savell i d., bartole r. & moretti e. (1984) caratteristiche litostratigrafiche con l'ausilio del sismografo di un terrazzo alluvionale del fiume metauro a fossombrone (marche settentrionali). acta naturalia de "l'ateneo parmense", 20 (1), pp. 63-79. savelli d. & nesci o. (1994) alcuni caratteri geomorfologici del fondovalle nella media e bassa valle del metauro. in: baldelli g., paci e. & tomassini l. “la battaglia del metauro”, minardi editore, fano, pp. 161-180. savelli d. & wezel f.c. (1978) schema geologico del messiniano del pesarese. boll. soc. geol. it., 97 (1-2), pp. 165-188. vernarecci a. (1903) fossombrone dai tempi antichissimi ai nostri, volume primo. mem. pubblicate a cura del municipio di fossombrone, soc. tipografica g. staurenghi & c., fossombrone, 560 pp. 193 ms. ricevuto il 26 aprile 2004 testo definitivo ricevuto il 19 ottobre 2004 ms. received: april 26, 2004 final text received: october 19, 2004. la città di forum sempronii ... available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 17 21 morphodynamics of coastal areas represented in the new geomorphologic map of italy: draw the landforms of the past to outline the future alessandro chelli 1 , domenico aringoli 2 , pietro p.c. aucelli 3 , maurizio a. baldassarre 4 , piero bellotti 4 , monica bini 5 , sara biolchi 6 , sara bontempi 4 , pierluigi brandolini 7 , lina davoli 4 , giacomo deiana 8 , sandro de muro 9 , stefano devoto 6 , gianluigi di paola 10 , carlo donadio 11 , paola fago 12 , marco ferrari 7 , stefano furlani 6 , angelo ibba 9 , elvidio lupia palmieri 4 , antonella marsico 12 , giuseppe mastronuzzi 12 , rita t. melis 8 , maurilio milella 12 , luigi mucerino 7 , olivia nesci 13 , paolo e. orrú 8 , valeria panizza 14 , micla pennetta 11 , daniela piacentini 13 , arcangelo piscitelli 12 , nicola pusceddu 7 , rossana raffi 4 , carmen m. rosskopf 10 , paolo sansó 15 , corrado stanislao 11 , claudia tarragoni 4 , alessio valente 16 1 dip. di scienze chimiche, della vita e della sostenibilità ambientale, università di parma, parma, italy 2 scuola di scienze e tecnologie, sezione di geologia, università degli studi di camerino, camerino, italy 3 dip. di scienze e tecnologie, università degli studi di napoli parthenope, napoli, italy 4 dip. di scienze della terra, università “sapienza”, roma, italy 5 dip. di scienze della terra, università di pisa, pisa, italy 6 dip. di matematica e geoscienze, università degli studi di trieste, trieste, italy 7 dip. di scienze della terra, dell’ambiente e della vita, università degli studi di genova, genova, italy 8 dip. di scienze chimiche e geologiche, università di cagliari, cagliari, italy 9 oss. coste e ambiente naturale sottomarino, dip. di scienze chimiche e geologiche, università di cagliari, cagliari, italy 10 dip. di bioscienze e territorio, università degli studi del molise, pesche (is), italy 11 dip. di scienze della terra, dell’ambiente e delle risorse, università degli studi di napoli federico ii, napoli , italy 12 dip. di scienze della terra e geoambientali, università degli studi di bari “aldo moro”, bari, italy 13 dip. di scienze pure ed applicate, università di urbino, urbino (pu), italy 14 dip. di storia, scienze dell’uomo e della formazione, università di sassari, sassari, italy 15 dip. scienze e tecnologie biologiche e ambientali, università del salento, lecce, italy 16 dip. di scienze e tecnologie, università del sannio, benevento, italy corresponding author: a. chelli <alessandro.chelli@unipr.it> abstract: in the framework of the revision of italian geomorphological legend (carg project) published in 1994 by the national geological service, the aigeo-working group coastal morphodynamic (wgcm) dealt with the revision of the legend concerning the landforms of the coast. the aims of the work were the updating of the symbology on the basis of the post-1994 results in the geomorphological researches and creating a legend more vocated to the solution of the problems of applied geomorphology and more suitable to be managed in gis environment. the wgcm started from the critical analysis of the classifications of coastal landforms proposed during the last century and it continued through a scientific discussion on the work that the members of the group performed by means of 12 case studies in which a correlation between landforms, processes and, dynamics was made. the geomorphological legend proposed by the wgcm has to be considered as a starting point and a work in progress. it remains, indeed, open so that new data can be added and updated as required. besides, the wgcm tried to contribute to the morphodynamic classification of the coasts around the mediterranean basin. keywords: coastal dynamics, coastal geomorphology, geomorphological mapping, mediterranean coast 1. introduction the geomorphological map is the basic tool for the representation of landforms of earth topographic relief and, as such, is currently the document present in most of the activities of environmental planning carried out in italy at the various institutional levels, from the national to the municipal one, with particular reference to the evaluation of geomorphological hazards and the mitigation of the associated risks. the geomorphological mapping in italy has reached high levels of scientific value in the description and analysis of the landscape and in returning correct territorial data from the dimensional point of view, as well as providing the necessary geomorphological information useful for the applied purposes in different scientific sectors, such as hydraulics, forestry sciences, agronomy, environmental engineering, architecture, landscape ecology, etc. besides, thanks to the capability to represent the state of activity of landforms, and of associated processes of course, the geomorphological mapping is the https://doi.org/10.26382/aiqua.2018.aiquaconference primary tool to provide a dynamic view of the landscape. the legend of the geomorphological map of italy (carg project) published in 1994 by the national geological service (brancaccio et al., 1994) represented the first document that summarized the different approaches to the representation of landforms that were developed in italy by different schools, since the sixties of the last century. in fact, the current system of italian geomorphological mapping has its origin from the works of authors such as castiglioni (1964) and panizza (1966) who have also worked in synergy with international groups and from the experience shared through workshops of informal working groups constituted by italian geomorphologists (gsueg, 1978; grg, 1982; gngfg, 1986; 1987; 1993; 1995). since 2015, the italian geomorphologists community has started, as part of the works of the italian association of physical geography and geomorphology (aigeo), the revision of the 1994’ legend, thanks to the work of the working groups (wgs) born within the association. the wg coastal morphodynamic (wgcm), established by aigeo in 2013, dealt with the revision of the legend concerning the landforms of the coast, dealing with the landforms of wave-climate and eolian origin, these latters having, in the morphoclimatic system that characterizes the italian peninsula, the best expressions in correspondence of the morphosedimentary dunebeach systems. the aims of the wgcm were: 1) to implement and update the symbology by introducing the results of the last 25 years of geomorphological research, 2) creating a legend and then a geomorphological map, with a 18 fig. 1 case studies: 1) bonassolalevanto rocky coast and embayed beach; 2) tellaro rocky coast; 3) the franco promontory and the campese bay; 4) isola dei gabbiani tombolo; 5) the coastal area of torre san giovanni capo san marco; 6) the tiber river delta; 7) littoral of the garigliano river mouth; 8) the la vota paralic system; 9) the roca sant’andrea coast; 10) the northen sector of the molise coast; 11) the northern coastal sector of the mt. conero promontory; 12) the rocky coasts of the gulf of trieste (from mastronuzzi et al., 2017). chelli a. et al. 19 greater vocation, compared to the current one, towards the solution of the problems of applied geomorphology, such as the analysis of the geomorphological hazards and risks and the exploitation of the geomorphological heritage, and 3) to think to symbols that can be more suitable, than the current one, for the creation of a cartographic system that is even more manageable through the use of gis tools. 2. the new geomorphologic legend of italian coast in the framework of the activities for the new geomorphological legend of the italian coast, the wgcm, other than the guide to geomorphological mapping of italy at the scale 1:50,000 (brancaccio et al., 1994), considered besides the results of the other important study concerning geomorphological mapping of the coasts of italy, i.e.: the atlas of italian beaches (atlante delle spiagge italiane; aa.vv., 1997) based on the results of the “conservazione del suolo”, “dinamica dei litorali” sub-project. the legend here proposed collects recent research advancements carried out by the community of italian coastal geomorphologists as well as the results of an articulated scientific discussion developed within the wgcm based on the work that the researches performed by means of 12 case studies (fig. 1) in which a correlation between landforms, wave-climate data, and dynamics is presented. the aim has been to summarise the most recent results in mapping the coastal landforms within the context of a long cultural process, involving the italian scientific community. the realization of the geomorphological legend was, indeed, the result of a theoretical approach, based also on the critical analysis of the classifications proposed during the last century (see finkl, 2004 and references therein), and of a coastal landscape analysis, recognising the landform genesis at a regional scale, while considering their evolution and present dynamics (shepard, 1973) in relation to the sea-level history and evolutionary trends of shore/coast line (valentin, 1952). the study focuses, indeed, on the entire coastal perimeter of italy, including different geodynamic areas, ranging from those characterised by high uplift rates to those stable or subsiding, in the mediterranean climate region, considered as a single morphoclimatic zone. the latter aspect considers the sea energy as “homogenous”, being only affected by lithology and exposure/fetch of each area. the role of 1) inherited landforms (i.e. hillslope or karst cave in submerged areas), 2) volcanic processes, which can characterise a coastal area, 3) continental processes in coastal areas (i.e.: landslides triggered by non-marine processes) and, 4) anthropogenic factors has been also considered. in order to address these issues, the primary task of this study has been to create a classification of coastal landforms which, compared to any previous descriptive/ genetic approaches, will be quantitative and dynamic in relation to processes. the coastal landforms are mainly classified in function of the genetic mechanism still active in their dynamics, while also taking into consideration inheritance, spatial and temporal scales, as well as potential changes in the architecture of the coastal landscape (mastronuzzi et al., 2017). the proposed legend has been subdivided into different thematic layers and at different map scales, reporting morphogenetic, morphometric, and morphodynamic data, and thereby facilitating their input into a geographical information system (gis). in this way, data reported on geomorphological map can be used for several purposes by different stakeholders, from researchers to land-use planners. with the adopted approach, the required geomorphological analysis of coastal landscapes has to be integrated using qualitative and quantitative data on landform genesis and dynamics. at first, it appeared fig. 2 theoretical flow-chart explaining the construction of the new geomorphological legend of the italian coast. the legend has been built starting from the analysis of the coastal landscape recognising the landform genesis, while considering their evolution and present dynamics in relation to the sea-level history and evolutionary trends of shore/coast-line (from mastronuzzi et al., 2017). geomorphologic mappping of coastal areas 20 chelli a. et al. b a fig. 3a,b the new geomorphological legend of the italian coast (from mastronuzzi et al., 2017). useful and necessary to maintain a purely descriptive approach of the coastal landforms and landscapes. however, from the perspective of the actual “end users”, it then became clearly evident that it would be much more useful to provide genetic and dynamic data. for this reason, in the legend, the description and the genesis of inherited landforms along with the description of their current dynamism have been included. information about inheritance and dynamism is especially useful in scenarios where a landform may not correlate to modern dynamic environment. landforms occurring in rocky coastal environment, such as sea caves and karst caves, both emerged and submerged, can be found in the same place even if their genesis results from two different morphogenetic systems and processes. for example, a marine cave could be the evolution of a karstic cave shaped in fully continental condition subsequently modified by marine erosive/ depositional or biochemical processes as the sea-level reached it. references aa vv. (1997) atlante delle spiagge italiane: dinamismo, tendenza evolutiva, opere umane. c.n.r. m.u.r.s.t., selca , 108 tavv. brancaccio l., castiglioni g.b., chiarini e., cortemiglia g.c., d’orefice m., dramis f., graciotti r., la posta e., lupia palmieri e., onorati g., panizza m., pannuzi l., papasodaro f., pellegrini g.b. (1994) carta geomorfologica d’italia 1:50.000. guida al rilevamento. quad. serv. geol. naz., ser.3, 4, pp. 42. castiglioni g.b. (1964) osservazioni morfologiche nella conca di bressanone. mem. accad. patav. ss.ll.aa., 76, 88 pp. finkl c.w. (2004) coastal classification: systematic approaches to consider in the development of a comprehensive scheme. journal of coastal research, 20, 1, 166-213. gruppo di ricerca geomorfologia (grg) (1982) geomorfologia del territorio di febbio tra il m. cusna e il f. secchia (appennino emiliano). geogr. fis. din. quat., 5, 2, 285-360. gruppo di studio delle università emiliane per la geomorfologia (gsueg (1978) geomorfologia dell’area circostante la pietra di bismantova (appennino reggiano). boll. serv. geol. d’italia, xcvii (1976), 107-214. gruppo nazionale di geografia fisica e geomorfologia (gngfg) (1986) ricerche geomorfologiche nell’alta val di peio (gruppo del cevedale). geogr. fis. din. quat., 9, 2, 137-191. gruppo nazionale di geografia fisica e geomorfologia (gngfg) (1987) cartografia della pericolosità connessa ai fenomeni di instabilità dei versanti. boll. soc. geol. ital., 106, 199-221. gruppo nazionale di geografia fisica e geomorfologia (gngfg) (1993) proposta di legenda geomorfologica ad indirizzo applicativo. geogr. fis. dinam. quat., 16, 2, 129-152. gruppo nazionale di geografia fisica e geomorfologia (gngfg) (1995) carta geomorfologica del bacino del trionto. selca, firenze. mastronuzzi g., aringoli d., aucelli p.p.c., baldassarre m.a. bellotti p., bini m., biolchi s., bontempi s., brandolini p., chelli a., davoli l., deiana g., de muro s., devoto s., di paola g., donadio c., fago p., ferrari m., furlani s., ibba a., lupia palmieri e., marsico a., melis r.t., milella m., mucerino l., nesci o., orrú p.e., panizza v., pennetta m., piacentini d., piscitelli a., pusceddu n., raffi r., rosskopf c. m., sansó p., stanislao c., tarragoni c., valente a. (2017) geomorphological map of the italian coast: from a descriptive to a morphodynamic approach. geogr. fis e dinam. quat., 40(2), 161-196. panizza m. (1966) carta e osservazioni geomorfologiche del territorio di calopezzati (calabria). riv. geogr. ital., 73, 1, 40 pp. shepard f.p. (1973) submarine geology. harper and row, new york, 519 pp. valentin h. (1952) die küsten der erde. petermanns geographisches mitteilungen ergänzsungheft, 246. pp. 118. 21 geomorphologic mappping of coastal areas ms. received: may 15, 2018 final text received: may 21, 2018 22 sess 1_160211.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 climatic and environmental changes of the santa gilla lagoon (cagliari) during the holocene anna maria porcu, antonietta cherchi, paolo e. orrù & paola pittau dipartimento scienze della terra, università degli studi di cagliari corresponding author: a. m. porcu <anna33146@hotmail.com> abstract: porcu a. m. et al., climatic and environmental changes of the santa gilla lagoon (cagliari) during the holocene. (it issn 0394-3356, 2011) through the study of two boreholes was possible to reconstruct the environmental and climate evolution of the last 10,000 years b.p. of the santa gilla lagoon. the data obtained are based on microfauna and palynomorphs analysis, integrated with geochemical analysis carried out on foraminifera calcareous shells. radiometric analysis were also performed to obtain a well-defined geochronology scale of sedimentary succession. riassunto: porcu a. m. et al.: variazioni climatiche e ambientali della laguna di santa gilla (cagliari) durante l’olocene. (it issn 0394-3356, 2011) attraverso lo studio di due sondaggi a carotaggio continuo è stato possibile ricostruire l’evoluzione ambientale e climatica degli ultimi 10.000 anni b.p. della lagna di santa gilla. i dati ottenuti sono basati sull’analisi della microfauna e dei palinomorfi, integrati con analisi geochimiche effettuate sui gusci calcarei dei foraminiferi. sono state inoltre compiute analisi radiometriche per ottenere una scala geocronologica ben definita della successione sedimentaria. keyword: foraminifera, palynology, stable isotope analyses parole chiave: foraminiferi, palinologia, analisi isotopiche  multidisciplinary study on the marine and continental microfacies from two boreholes of the santa gilla lagoon allowed to reconstruct the environmental, climate and vegetation changes that occurred in the gulf of cagliari during the holocene. palynologic (pollen and spores analyses), micropaleontologic (benthic foraminifers) and isotopic data (δ18o and δ13c) over the past 10.000 years b.p. from this transitional-coastal sequence show a series of shift leading to the establishment of different climatic conditions. the investigated archives included lagoonal organic shales, posidonia peat and coastal, fine and medium sandstone. radiocarbon dating and multiproxy analyses were performed on 30 meters of succession. the radiometric analysis allowed to date the sedimentary series, placing the beginning of the lagoon silting process from moments immediately after the younger dryas (orrù et al., 2004; antonioli et al., 2007) and to compare the sedimentary succession to the northern european chronostratigraphy. the coastal sediments are the reservoir of biological and lithological information on mutual relations continent-sea. any sea level change, both eustatic and isostatic and tectonic, left its marks on the fossil faunal and microfaunal composition. through the foraminifera study and according to the knowledge on their ecology (sgarella & moncharmont zei, 1993; cimerman & langer, 1998; fiorini & vaiani, 2001), have been detected environmental characteristics that have occurred during the lagoon filled. benthic foraminifer association were identified and assembled into five main eco-groups that have shown the transition from lagoonal environment (10.000-9.000 years b.p.) to marine sublittoral with a very close lagoon (9.0003000 years b.p.) and then return to the lagoonal but with marine influences (3.000-250 years b.p.) and re-opened to the sea (250 years b.p.-actual). any climatic change, if it exceeds a certain threshold, gives a change in the vegetation which is recorded in coeval sediments by the palynological record. the sequence of sporo-pollen spectra provides the vegetation evolutionary pattern of the source area of the studied basin. the palynological study allowed the vegetation spectra reconstruction (reille, 1992; reille, 1995; reille, 1999) showing five phases and a sub-phase, marked by an appreciable evolution in terms of frequency curves that represent the stages of the vegetation dynamics of last 10,000 years under the climate influence. the vegetational response to the amelioration of the climate in the early holocene (9.800 -7.600 years b.p.) resulted in the spread of the ericaceae macchia (first phase) and the setting of the quercus forest between 7.700-7.600 years b.p. (sub-phase). this was followed by a shift toward drier and more open vegetation mainly represented by chenopodiaceae (second phase) at 7.600-7.200 years b.p. at 7.200-4.800 years b.p. a more persistent peak in deciduous quercus values signal a reestablishment of wetter conditions and the maximum extension of the quercus forest (third phase). alternated drier (chenopodiaceae) 51 53 52 fi g. 1, g eo ch ro no lo gi ca l, ch ro no st ra tig ra ph ic , o f t he p al eo te m pe ra tu re s, p al eo ve ge ta tio n, p al eo en vi ro nm en ta l, an d pa le oc lim at ic s ch em e of th e st ud ie d su cc es si on s. s ch em a ge oc ro no lo gi co , c ro no st ra tig ra fic o, d el le p al eo te m pe ra tu re , p al eo ve ge ta zi on al e, p al eo am bi en ta le , e p al eo cl im at ic o de lle s uc ce ss io ni s tu di at e a.m. porcu et al. 53 ms. received: testo ricevuto il and wetter phase with developpement of quercus orest even in the coastal plains followed. the last chenopodiaceae arid and cold phase (fifth phase) fitted with the little ice age (216±100 years b.p.). because eustatic changes are not always depend on climate, but climate change almost always produce eustatic changes, the integrated study of microfauna and continental flora provides a much valuable investigation means in the evolution reconstruction of coastal areas and climate evolution of a region. climate change producing water temperature and salinity variations, which are recorded in the lagoon from microfaunas through the relation changes of oxygen and carbon isotopes. the isotopic analysis (δ18o and δ13c) were carried out on the shells of two species of foraminifera, ammonia tepida and elphidium granosum, good indicators of lagoon and estuarine environments (cronin et al., 2005). were obtained two types of scales for each species: a multi-decadal scale and a multi-centennial scale, obtained by the method of 5-point running average. the long-term variability of δ18o values (multi-centennial, 200400 years, time-scales) indicate a variable positive trend from 9.450 to 7.500 years b.p. approximately, and a negative trend from approximately 7.100 to 2.000 years b.p. the multi-centennial time-scale of the δ13c values indicates a variable decreasing negative trend from 10.00to 7.700 years b.p., that we regard reflecting increasing salinity waters culminating with the remarkable marine rising of the holocene optimum climaticum. higher δ13c negative values from 7.500 to 3.850 years b.p. are regarded as indicative of higher precipitation with higher organic influx of terrestrial origin; whereas the succeeding higher δ13c values up to 1.850 a.d. are indicative of increasing water salinity. variable amplitude fluctuations at multi-decadal time-scale, 20-30 years, are superimposed on these long-term trends.     references antonioli f., anzidei m., lambeck k., auriemma r., gaddi d., furlani s., orrù p.e., solinas e., gaspari a., karjnja s., kovačić v. & surace l., (2007) sea level change during the holocene in sardinia and in the north-eastern adriatic (central mediterranean sea) from archaeological and geomorphological data. quarternary science review 26, 2463 –2486. cimerman f. & langer m. r. (1991) mediterranean foraminifera ljubljana, slovenska akademia, 118 pp., 93 pls. cronin t. m., thunell r., dwyer g. s., saenger c., mann m. e., vann c. & seal r. r. (2005) – multyproxy evidence of holocene climate variability from estuarine sediments, eastern north america. paleocenography, 20. fiorini f. & vaiani s. c. (2001) – benthic foraminifers and transgressive-regressive cycles in the late quaternary surface sediments of the po plain near ravenna (northern italy). boll. soc. paleont. ital., 40 (3), 357-403. orrù p. e., antonioli f., lambeck k. & verrubbi v. (2004) – holocene sea-level change in the cagliari coastal plain (southern sardinia, italy). quaternaria nova, 8, 193-212. sgarrella f. & moncharmont zei m. (1993) benthic foraminifera of the gulf of naples (italy): systematics and autoecology boll. soc. paleont. ital., 32 (2), 145-264. reille m. (1992) – pollen et spores d’europe et d’afrique du nord. laboratoire de botanique historique et palynologie, marseille, 544 pp. reille m. (1995) – pollen et spores d’europe et d’afrique du nord. laboratoire de botanique historique et palynologie, marseille, supplémet i, 332 pp. reille m. (1995) – pollen et spores d’europe et d’afrique du nord. laboratoire de botanique historique et palynologie, marseille, supplémet ii, 521 pp. reille m. (1999) – pollen et spores d’europe et d’afrique du nord. laboratoire de botanique historique et palynologie, marseille, 535 pp. climatic and environmental changes of the santa ... january 15, 2011 15 gennaio 2011 amq99 didonato et al.pub compositional regression-based methods for sst reconstruction. valentino di donato 1, joanna jamka 1, josep antoni martín-fernández 2 1 dipartimento di scienze della terra, dell’ambiente e delle risorse, università degli studi di napoli “federico ii”, naples, italy. 2 departament d’informàtica, matemàtica aplicada i estadística, universitat de girona, spain. corresponding author: v. di donato <valedido@unina.it> abstract: the information in modern or fossil foraminifera assemblages is the relative abundance or percentages of species, i.e., they can be considered as compositional data. in this study we deal with coda and regression-based methods as tools to estimate past climatic conditions. we tested standard and robust partial least squares and principal component regression, applied to the log-ratio coordinates of percentage data of atlantic ocean and mediterranean sea planktonic foraminiferal assemblages. due to the presence of groups, it was preferred to model separately high latitude and mid to low latitude assemblages. this approach implies the application of cluster analysis, manova and discriminant analysis to the logratio transformed fossil assemblage’s compositions. the methods were then applied on marine core assemblages to reconstruct past sea surface temperatures. the obtained results were compared with those formerly obtained by means of compositional modern analogue technique and with the information arising from other paleoclimatic proxies. keywords: partial least squares, principal components regression, compositional data analysis, sea surface temperatures, isometric logratio transformation. available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 32 (1), 2019, 31-41 1. introduction in the last decades, several methods were proposed to obtain quantitative estimates of past environmental parameters from counts of fossils assemblages (imbrie & kipp, 1971, hutson, 1979; ter braak & juggins, 1993; pflaumann et al., 1996; waelbroeck et al., 1998; malmgren et al., 2001; among others). most methods are applied to percentage data obtained from counting of specimens. the peculiar properties of relative abundance data represent however a key issue to be taken into account when developing transfer functions based of fossil assemblages. percentage data belong to compositional data (coda) (aitchison, 1986): that is, the information contained in a vector of counts x is the same as in k·x, for any real scalar k>0, property known as scale invariance which indicates that a composition is an equivalence class (barceló-vidal & martínfernández, 2016). this type of data is very common in earth sciences when the constituents and compounds are described in terms their concentration (e.g., buccianti et al., 2006). in a paper recently published (di donato et al., 2018) we revised the modern analogues technique (mat) (hutson, 1979; pflaumann et al., 1996; waelbroeck et al., 1998) according to the coda methodology (aitchison, 1986). in this study, following the same approach, we deal with regression-based methods, such as principal component regression (pcr) and partial least squares regression (plsr). in order to apply plsr to coda, hinkle & rayens (1995) proposed logcontrast partial least squares (lcpls). coda refers to vectors of positive components showing the relative weight of a set of parts in a total. nowadays, there is a general agreement that applying the standard statistical methods to coda may yield misleading results (pawlowsky-glahn et al., 2015). the log-ratio methodology proposed by aitchison (1986) and the following developments (i.e. martín-fernández & thió-henestrosa, 2016a; martín-fernández & thió-henestrosa, 2016b) represent a powerful set of methods and techniques to apply to coda. the approach adopted in this paper follows the principle of working on coordinates (mateufigueras et al., 2011), that is, the standard statistical analysis is conveniently performed after choosing logratio coordinates. in particular, we considered to express each d-vector x = (x1, ..., xd) of percentages of species as: 1) a d-dimensional vector z=(z1, ..., zd) of centred log-ratio coordinates (z =clr(x)) (aitchison, 1986) and 2) a (d−1)-dimensional real vector y=(y1, ..., yd-1) of isometric log-ratio coordinates (y =ilr(x)) (egozcue et al., 2003) (see appendix 1 in di donato et al. (2018) for definitions and details). to develop our approach, the following points were considered: 1) pre-processing techniques; 2) elaboration of regression-based transfer functions 3) evaluation of the results 4) application to fossil assemblages. as case studies, we considered applications based on the estimation of past sea surface temperatures (sst) from planktonic foraminifera assemblages. however, the described methods may be applied to different palaeoecological contexts. the analyses were carried out with matlab codes except for raw-data analysis which was computed with r package rioja https://doi.org/10.26382/amq.2020.02 32 di donato v. et al. (juggins, 2017). matlab routines expressly written to perform coda-regression and codamat are provided in the supplementary materials. the robust partial least squares regression requires the rsimpls.m matlab code included in the libra package (verboven & hubert, 2004), available at https://github.com/ duncombe/matlab/blob/master/libra/rsimpls.m. a workflow of the analysis is shown in table 1. 2. approaching the analysis 2.1. the dataset the dataset on which our applications are computed is represented by a database consisting of 1252 atlantic and mediterranean planktonic foraminifera coretop assemblages, which represent the regressor variables, determined on the >150 μm size fraction (prell et al., 1999; hayes et al., 2004; kucera et al., 2004) (fig. 1). in this paper we considered sst as response variables. the oceanographical data, consisting of mean annual and seasonal sst refer to antonov et al. (2010) and locarnini et al. (2010). seasonal temperatures are 3 months averages, i.e. january–march for northern (southern) winter (summer) and july–september for northern (southern) summer (winter). the sst values at coretop locations were computed by means of ocean data view 4.7.10 (schlitzer, 2018). following kucera et al. (2005), oceanographical data are related to a depth tab. 1 workflow of the analysis fig. 1 location of modern planktonic foraminifera coretop samples adopted for application of coda-mat. drawn with ocean data view software (schlitzer, 2018). 33 coda regression-based sst reconstruction of 10 m. 2.2 data pre-processing: subcomposition, amalgamation and zero replacement the data pre-processing which is needed to accomplish the analysis is fully explained in di donato et al. (2018) and will not be detailed here. in short, our approach requires data to be strictly positive (aitchison, 1986). to reduce the number of zero values to be replaced, rarer species, which carry inevitably low signal to noise ratios (kucera et al., 2005) can be excluded from the assemblages, by considering a subcomposition (aitchison, 1986) of the original assemblages. moreover, an amalgamation of taxa characterised by similar ecological requirements can be also considered (aitchison, 1986). to manage the zeros occurring in the data, we adopted a mixed bayesian-multiplicative estimation approach, which is recommended when the compositional data arise from counts (martín-fernández et al., 2003; martín-fernández et al., 2015) (see also appendix 1 in di donato et al., 2018). after the zero replacement, the clrand ilrcoordinates’ vectors for the fossil and modern data are obtained. thus, fossil assemblages are represented by its logratio-coordinates, whereas the modern database is consisting of logratio-coordinates together with the environmental parameters measured at each location. the ilr coordinates can be computed by means of balances (egozcue et al., 2005). these are logcontrasts obtained by means of a sequential binary partition (sbp) matrix. for each order of the partition, it is possible to define the balance between the two sub-groups formed at that level: if i1, i2,…, ir are the r parts of the subgroup coded by +1, and j1, j2,…, js the s parts of the subgroup (coded by -1), a balance is defined as: from a d part composition, d-1 balances (ilrcoordinates) can be obtained. in our case, for the sake of simplicity, we adopted a matrix of the type: as explained in di donato et al. (2018), two datasets were generated, consisting of respectively 19 and 15 taxonomical groups (see appendix 2 in di donato et al., 2018). order x1 x2 x3 xd-1 xd 1 1 -1 -1 …. -1 -1 2 0 1 -1 …. -1 -1 3 0 0 1 …. -1 -1 …. …. …. …. …. …. … . d-1 0 0 0 …. 1 -1 2.3. multiple regression methods the plsr and pcr methods applied to perform the palaeo-estimates are models recommended to predict a response variable when there are a large number of predictor variables highly correlated (ter braak & juggins; 1993 juggins, 2017). both methods construct new orthogonal, hence not correlated, predictor variables as linear combinations of the original predictor variables. however, while pcr creates components to maximise the observed variability in the predictor variables, without considering the response variable at all, plsr creates components by maximising the covariance between predictors and response variables. for plsr we adopted the simpls algorithm (de jong, 1993). we also tested a robust pcr (rpcr) and robust pls (rsimpls) (hubert & branden, 2003). in order to comply with the coda approach, both analyses should be computed on ilr coordinates. it can be noted, however, that clrand ilr coordinates, provide the same results for both pcr and plsr (filzmoser et al., 2018). hereafter we denoted with coda-plsr and coda-pcr the analysis performed on log-ratio coordinates. the main advantage of clr-coordinates is that they are logcontrasts more easily interpretable. however, ilr-coordinates are advantageous when the analysis requires full rank data, such as discriminant analysis. in order to evaluate the number of pls components to be taken into account, we considered, as usual, the percent of variance explained in the response variable and the mean-squared errors (see section 2.4) as a function of the number of components. for coda-pcr we considered the percent of total variance of regressor variables. the relative variation biplot (rvb) of the planktonic foraminifera assemblages included in the modern dataset is shown in figure 2. a rvb consists of a standfig. 2 relative variation biplot (rvb) of planktonic foraminiferal assemblages included in the modern dataset. row points are grouped according to their latitude. ard principal components biplot applied to the clr coordinates of the assemblages. the first two axes accounts for about 63% of total variability (a total of 71% is reached if a third axis is added). the location of the data points in the rvb highlights the well-known broad latitudinal distribution of assemblages. it can be noted that the origin of the rvb corresponds to a low-density area. moreover, the distribution of data points in the rvb seems to indicate the existence of two groups within the dataset, the first of which is represented by high latitude assemblages. principal components analysis (pca) is properly defined for homogeneous, normally-distributed data from a single population (tolosana-delgado & mc kinley, 2016). thus, we considered evaluating, apart from a regression model built with the whole dataset, two separate models for high latitude and low to middle latitude assemblages. separate regional models were considered, among others, in prell (1995), ortiz & miz (1997) and kucera et al. (2005). for our purposes, a cluster analysis (ward’s method on ilr-coordinates) was applied to the dataset, discarding then some observations that did not belong to either of the two main defined groups. a manova test indicates that the two groups are significantly distinct (with p~0). since at high latitude only few planktonic foraminifera species occur, the regression models for the high latitude group was built by considering a sub-composition of the dataset made of only 5 species. the application of this two-step procedure to fossil assemblages requires to first perform a linear discriminant analysis (lda) in order to classify them into one of the 2 defined groups. apart from theoretical considerations, the application of lda to percentage data faces problems related to the singularity of the within groups variance/covariance matrix. this problem also occurs with clr-coordinates, while ilr-coordinates are not affected by this problem. the lda misclassification rate provided a leave-one-out cross validation method for the two groups defined in the modern dataset is 0.0085. 2.4. evaluation of the quality of the estimates the evaluation of the quality of the estimated results provided by coda-pcr and coda-plsr techniques has been carried out by means of sensitivity analysis of leave-one-out cross validation method (ter braak & juggins, 1993; barrows & juggins, 2005). the indices we took into account were: the coefficient of determination r2 and the mean square error of prediction (msep) (with its square root, the rmsep) (wallach & goffmet, 1989; birks, 1995) and as multivariate counterpart, the root of mean squared distances (rmsd) (e.g., martín-fernández et al., 2003). the msd is a multivariate index of quality of the estimates of k environmental parameters defined as: where n is the number of modern samples, represents the vector of k measured environmenal parameters, and the corresponding vector of estimated values. this approach is equivalent to analyse the mean of the norm of the residual rows (difference between measured and estimated parameters). the best result of rmsd is obtained when rmsd=0, i.e, all the estimates are equal to the measured values. the multivariate approach may be applied when different paleoclimatic parameters are estimated (i.e. temperature, seasonal or annual precipitation, potential evapo-transpiration, as done in pollen analysis). for the evaluation of the results obtained from grouped assemblages, we considered both a “pooled” r2, i.e. for 2 groups, r2=(ssr gr1+ssr gr2)/(sst gr1+sst gr2), together with the squared correlation coefficient r2 obtained by comparing the overall (both groups) measured and fitted sst values. squared correlation coefficients are reported in the supplementary materials. 2.5. application on fossil assemblages probably the most important difficulty of any proxybased reconstruction is represented by the no-analogue problem, occurring when the palaeoenvironmental conditions represented in the fossil assemblages do not have a correspondence in modern environments (hutson, 1977). it can be considered that the application of regression methods to no-analogue samples, may be regarded as extrapolation rather than interpolation (conn et al., 2015). in di donato et al. (2018), we adopted atypicality index (e.g., aitchison, 1986), both standard and robust, and local outlier factor (lof) (breunig et al., 2000) of assemblages as tools to detect noanalogue conditions. details on the computation of atypicality index and robust methods to outlier detection (peña & prieto, 2001) for coda sets (filzmoser & hron, 2008) are reported in di donato et al., 2018. 3. testing the method 3.1. results the number of components from which compute the pls was determined by considering the percent variance explained for the response variables and the mse of response variable as functions of the number of pls components (fig. 3) and, for coda-pcr, the amount of total variance of regressor variables accounted by the principal components (fig. 4). for both the tested datasets, 4 components seem to provide an adequate coda-plsr model. for coda-pcr, we adopted a 6 components model. as regards the two-groups approach, the subcomposition obtained for high latitude assemblages is made of only 6 parts. in the other group, for both coda-plsr and coda-pcr, we considered a full-components model. we tested both annual sst and seasonal sst. the relationships between measured and estimated seasonal sst obtained with pcr and plsr under different conditions are reported in the supplementary materials. in general, the 15 taxa and 19 taxa datasets provided quite similar results. it can be noted, that, for both coda-pcr and coda-plsr, higher squared correlation coefficients and lower rmsep are obtained with a two-groups analysis. the highest r2 of 0.9718, with a rmse of 1.33°c was obtained for mean annual sst with coda-plsr. figure 5 shows the relationship between measured and cross-validation-estimated sst for 34 di donato v. et al. a 1 group and for 2-groups analysis. it can be noted that, the 1-group model, a “plateau” for low sst, which can be also observed, in the imbrie & kipp (1971) method and coda-mat validation, and which becomes much less pronounced, with a 2-groups modelling. for a single group analysis, plsr performs better than pcr. however, for a 2 groups analysis, plsr and pcr provided quite similar results. robust version of coda-plsr and coda-pcr did not improve the fitting with respect to standard coda-plsr and coda-pcr. in comparison with the coda-mat method, coda-plsr and coda-pcr provides slightly lower r2 and higher rmsep. a slightly better performance of mat with respect to a regression method (i.e. the imbrie & kipp transfer function) was also found by ortiz & mix (1997) by working on raw percentage data. as far as the comparison with raw data regression-based methods, on our dataset, the imbrie & kipp (1971) q-mode regression method yields, with 5 components an r2=0.8956 and an rmse=2.47°c. the weighted averaged partial least 35 fig. 3 the figure shows for the 15 taxonomic groups dataset plots (from which 14 predictors represented by ilr-variables are obtained) of a) the percent variance explained for a single response variable (annual sst) and b) the mse of response variable as functions of the number of pls components. fig. 4 plot of cumulative percentage accounted (blue line) and variance contribution of each component (red line) in codapcr. fig.5 plots of observed versus estimated sst (annual and seasonal) obtained with a 1-group (left) and a 2-groups coda-plsr modelling. coda regression-based sst reconstruction squares method (wapls) (ter braak & juggins, 1993) yields an r2=0.9544 and an rmse=1.70°c. 3.2. application examples as an application example, the coda-mat method was applied to planktonic foraminifera records which were also considered to evaluate the performing of coda-mat. the first one is a literature dataset, consisting of the record of planktonic foraminifera assemblages of the core md95-2040 (de abreu et al., 2003; voelker & de abreu, 2011), recovered in the atlantic ocean off the iberian margin, the second is that of gns84-c106 core recovered in the tyrrhenian sea (buccheri et al, 2002; di donato et al., 2008; 2009). for the mediterranean sea, we also considered the planktonic foraminiferal record of the core tea-c6 (di donato et al., 2019), from which an estimate of past sst for the last 15 ka, was obtained with the coda-mat method. all datasets are obtained from >150 μm size fractions. the location of the cores is shown in figure 6. a discussion of the possible drawback represented by the excessive loss of small sized species in the >150 μm size fraction can be found in di donato et al. (2015). it can be noted that >150 micron and >106 μm datasets, if analysed with coda methods, provide the same covariance structure. this suggests that regression-based methods based on coda, may be quite robust with respect to treatment changes such as the analysed size fraction. 3.2.1. atlantic ocean the foraminiferal record of md95-2040 core covers the last 210 ka (de abreu et al., 2003; voelker, & de abreu, 2011). sst for this interval were formerly reconstructed (de abreu et al., 2003) from planktonic foraminifera with simmax28 method (pflaumann et al., 1996). the dataset consists of 732 assemblages. as regards the atypicality of assemblages, in relation to the 99.5 percentile only 4% of the samples have mahalanobis distances are above the xi-square critical value of 31.32 (see figure 6 in di donato et al., 2018). as for the lof it can be noted that glacial assemblages are characterised by higher values of up to 2, while most interglacial assemblages have lof values not exceeding 1.5. on the basis of lda computed on ilr-coordinates, 98 assemblages were classified into the high latitude assemblage group, and 634 assemblages into the low to middle latitude assemblage group. the output of the lda with the indication of the group to which each assemblage was assigned with the posterior probabilities is provided in the supplementary materials. a comparison between the values reconstructed for summer and winter sst by means of simmax28 (de abreu et al., 2003), coda-mat, coda-plsr and codapcr is shown in figure 7. the stronger coherence of coda-mat reconstruction with alkenones and the stable isotope record with respect to simmax28 has been already highlighted in di donato et al. (2018). here we note that coda-plsr and coda-pcr reconstruction are largely overlapping and show a same general trend if compared with coda-mat. several sst minima, which correspond to heinrich events, are also recorded by coda-plsr and coda-pcr with slightly less-deep minima in comparison with coda-mat but more marked in comparison with alkenones record. coda-mat and regression-based methods also provide different sst reconstructions for the mis5: the former provides higher sst estimates, while the latter highlight a decreasing trend during the mis5 which does not appear in the coda-mat reconstruction. the sst reconstructed with the 15 taxa and the 19 taxa datasets, are quite similar, being characterised by a r=0.9865 (r= 0.9868) and by a root mean squared difference of 0.70°c (0.48°c) for summer (winter) sst. the multivariate rmsd between 15 taxa and the 19 taxa reconstructed sst is 0.7177. 3.2.2. mediterranean sea the core gns84-c106 recovered in the gulf of salerno (tyrrhenian sea western mediterranean) covers the last 34 ka (di donato et al., 2009). this dataset is represented by 228 planktonic foraminiferal assemblages determined on the >150-micron size fraction. the quantitative reconstructions of past climatic conditions for the mediterranean basin face several problems related to the peculiar hydrological asset of this semienclosed basin. reconstructions became even more problematic for glacial intervals (sbaffi et al., 2001, among others). as regards the lda, the whole core gns84-c106 dataset was classified into the low to middle latitude group (see supplementary material). however, as shown in figure 8, a significant atypicality index 36 fig. 6 location of cores considered in this paper. -------->>>>> fig. 7 reconstruction of seasonal sst for the last 210 ka off the iberian margin from core md95-2040 and comparison between simmax28 (de abreu et al., 2003, voelker & de abreu, 2011), coda-mat, coda-plsr and coda-pcr reconstructed ssts. a) summer and b) winter simmax28 reconstruction. c) summer and d) winter sst coda-based reconstructions. grey lines indicate the standard deviation of coda-mat estimates e) alkenone based sst reconstruction (pailler & bard, 2002). f) globigerina bulloides stable isotope record and marine isotopic stages (mis) (abreu et al., 2003; schönfeld et al., 2003): grey-shaded dots: distance of fossil assemblages from each of the 6 closest modern analogues. full line: mean values. g) lof values (see di donato et al., 2018) h) atypicality index: 0: not significant; 1: significant. di donato v. et al. 37 coda regression-based sst reconstruction was found for several planktonic foraminiferal assemblages of the core gns84-c106. as in the previous case study, coda-plsr and coda-pcr provide quite similar results. for this core, however, within the same general trend, regression-based methods and codamat provide quite different results. in this case study, raw percentage data mat and, to a lesser degree, coda-mat provided summer sst which seem quite high for the gi-1 interval and for time intervals of the last glacial period centred around 24 and 20 ka bp. this problem is likely partly related to the adopted size fraction (di donato et al., 2015). regression based methods seem to provide a more coherent sst trend, i.e. last glacial period lower than holocene, and intermediate sst values during the late glacial. however, it can be noted that coda-plsr and coda-pcr provide higher sst estimates for the colder intervals of the glacial peri 38 od. as an example, between 15 and 17 ka bp, codamat reconstruct winter sst of even 8.5 °c, while coda -plsr and coda-pcr indicate lower values of about 10°c. for this core, we do not have, at present alternative proxy-based reconstructions. however, the regression based reconstructed ssts seem more coherent with alkenone-based reconstructions obtained for the southern tyrrhenian sea (sbaffi et al, 2001), which provided higher sst values if compared with the mat reconstructions. during the holocene, coda-mat, coda-plsr and coda-pcr indicate an sst rise around 5 ka bp. however, coda-plsr and coda-pcr indicate warmer than present sst for an interval centred around 4 to 3 ka bp, which coincides with a peak in the warm species globigerinoides sacculifer widely recognized in the mediterranean sea (capotondi et al., 1999; among others) and a decreasing trend afterwards. this trend is fig. 8 reconstruction of seasonal sst obtained from gns84-c106 core. a) summer b) winter. the grey error bars indicate the standard deviation of each reconstructed value. c) lof values e) atypicality index: 0: not significant; 1: significant. the intimate greenland event stratigraphy is reported from rasmussen et al. (2014). di donato v. et al. quite similar to the alkenones record of the core bs7938 recovered in the southern tyrrhenian sea (sbaffi et al, 2001). however, alkenones provided higher than present sst values for the early to middle holocene which are not confirmed by planktonic foraminifera. 4. conclusive remarks following out previous paper focused on coda and modern analogue technique, in this article we developed a transfer function based on multivariate regression methods in a fashion coherent with a coda approach. the main advantages of coda-mat, being a non-parametric method (guiot & de vernal, 2011a;b), is its flexibility and the fact that the quality of each single reconstruction can be evaluated by means local outlier factor and mean distances. by contrast, once the model has been built, we must accept the reconstructed sst “as they are”. likely, coda-plsr might be more sensitive than coda-mat to random effects, since limited random effects should not strongly influence the choice of the best modern analogs for a fossil assemblage. however, coda-plsr and coda-pcr, may be more robust with respect to treatment changes such as the size fraction adopted for the analysis, which represent a critical point in the analysis of foraminifera assemblages. whatever the approach, it is important to evaluate the atypicality of the fossil assemblages in comparison with modern ones. in this article we provided application examples for an atlantic ocean and a mediterranean sea core. coda-mat and regression-based methods seem to provide quite coherent reconstructions for the atlantic ocean, while for the mediterranean sea, the obtained reconstructions are, as expected, more problematic. together with coda-mat, coda-plsr and coda-pcr provide the basis for more extensive reconstructions which will be the focus of future investigations. acknowledgements we would like to thank the two reviewers for their careful reading of the paper and their helpful comments and prof. adele bertini for her support in the revision of the article. this work has been supported by the project “codamet” (ministerio de ciencia, innovación y universidades; ref: rti2018-095518-b-c21). references aitchison j. (1986) the statistical analysis of compositional data. monographs on statistics and applied probability. chapman and hall ltd. (reprinted 2003 with additional material by the blackburn press), london (uk), pp. 416. antonov j.i., seidov d., boyer t.p., locarnini r.a., mishonov a.v., garcia h.e. (2010) world ocean atlas 2009 volume 2: salinity. s. levitus, ed., noaa atlas nesdis 69, u.s. government printing office, washington, d.c., pp. 184. barceló-vidal c., martín-fernández j.a. (2016) the mathematics of compositional analysis. austrian journal of statistics, 45(4), 57-71. barrows t.t, juggins s. (2005) sea-surface temperatures around the australian margin and indian ocean during the last glacial maximum. quaternary science reviews, 24, 1017-1047. birks h.j.b. (1995) quantitative palaeoenvironmental reconstructions. in: maddy, d., brew, j.s. (eds.), statistical modelling of quaternary science data. technical guide 5. quaternary research association, cambridge, 116-254. breunig m.m., kriegel h.-p., ng r.t., sander j. (2000) lof: identifying density-based local outliers. in proceedings of the 2000 acm sigmod international conference on management of data (sigmod '00). acm, new york, ny, usa, 93-104. doi: 10.1145/342009.335388 buccheri g., capretto g., di donato v., esposito p., ferruzza g., pescatore t., russo ermolli e., senatore m.r., sprovieri m., bertoldo m., carella d., madonna, g. (2002) a high resolution record of the last deglaciation in the southern tyrrhenian sea: environmental and climatic evolution. marine geology, 186, 447-470. buccianti a., mateu-figueras g., pawlowsky-glahn v. (eds.) (2006) compositional data analysis in the geosciences: from theory to practice. in: special publications, vol. 264. geological society, london. pp. 207. capotondi l., borsetti a.m., morigi c. (1999). foraminiferal ecozones, a high resolution proxy for the late quaternary biochronology in the central mediterranean sea. marine geology, 153, 253-274. conn p.b., johnson d.s., boveng p.l. (2015) on extrapolating past the range of observed data when making statistical predictions in ecology. plos one 10(10): e0141416. doi: 10.1371/journal.pone.0141416 de abreu l., shackleton n.j., schonfeld j., hall m., chapman m. (2003) millennial-scale oceanic climate variability off the western iberian margin during the last two glacial periods. marine geology, 196 (1-2), 1-20. de jong s. (1993) simpls: an alternative approach to partial least squares regression. chemometrics intell. lab. syst., 18, 251-263. di donato v., esposito p., russo ermolli e., scarano a., cheddadi, r. (2008) coupled atmospheric and marine palaeoclimatic reconstruction for the last 35 ka in the sele plain-gulf of salerno area (southern italy). quaternary international, 190, 146-157. di donato v., esposito p., garilli v., naimo d., buccheri g., caffau m., ciampo g., greco a., stanzione d. (2009) surface-bottom relationships in the gulf of salerno (tyrrhenian sea) over the last 34 kyr: compositional data analysis of palaeontological proxies and geochemical evidence. geobios, 42, 561-579. di donato v., martin-fernandez j.a., daunis-i-estadella j., esposito, p. (2015) size fraction effects on planktonic foraminifera assemblages: a compositional contribution to the golden sieve rush. mathematical geosciences, 47(4), 455-470. di donato v., martín-fernández j.a., comas-cufí m., jamka j. (2018) palaeoenvironmental reconstructions through compositional data analysis. 39 coda regression-based sst reconstruction alpine and mediterranean quaternary, 31(1), 5973. di donato v., insinga d.d., iorio m., molisso f., rumolo p., cardines c., passaro s. (2019) the palaeoclimatic and palaeoceanographic history of the gulf of taranto (mediterranean sea) in the last 15 ky. global and planetary change, 172, 278-297. egozcue j.j., pawlowsky-glahn v. (2005) groups of parts and their balances in compositional data analysis. mathematical geology 37(7), 795-828. egozcue j.j., pawlowsky-glahn v., mateu-figueraz g., barceló-vidal c. (2003) isometric logratio transformations for compositional data analysis. mathematical geology 35(3), 279-300. filzmoser p., hron k. (2008) outlier detection for compositional data using robust methods. math. geosciences, 40, 233-248. filzmoser p., hron k. templ, m. (2018) applied compositional data analysis. springer, pp. 280. doi: 10.1007/978-3-319-96422-5 guiot j., de vernal a. (2011a) is spatial autocorrelation introducing biases in the apparent accuracy of paleoclimatic reconstructions? quaternary science reviews 30, 1965-1972. guiot j., de vernal, a. (2011b) qsr correspondence “is spatial autocorrelation introducing biases in the apparent accuracy of palaeoclimatic reconstructions?” reply to telford and birks. quaternary science reviews, 30, 3214-3216. hayes a., kucera m., kallel n., sbaffi l., rohling e. (2004) compilation of planktic foraminifera modern data from the mediterranean sea. pangaea. doi: 10.1594/pangaea.227305 hinkle j., rayens w. (1995) partial least squares and compositional data: problems and alternatives. chemometrics and intelligent laboratory systems 30(1), 159-172. hubert m., branden k.v. (2003) robust methods for partial least squares regression. j. chemometrics, 17, 537-549. doi: 10.1002/cem.822 hutson w.h. (1977) transfer functions under noanalog conditions: experiments with indian ocean planktonic foraminifera, quaternary research, 8, 355-367. hutson w.h. (1979) the agulhas current during the late pleistocene: analysis of modern faunal analogues. science, 207(1), 64-66. imbrie j., kipp n.g. (1971) a new micropaleontological method for paleoclimatology: application to a late pleistocene caribbean core. the late cenozoic glacial ages. new haven, yale university press, 71-181. juggins s. (2017) rioja: analysis of quaternary science data, r package version (0.9-21). http://cran.r-project.org/package=rioja kucera m., weinelt m., kiefer t., pflaumann u., hayes a., weinelt m., chen m.-t., mix a.c., barrows t., cortijo e., duprat j., juggins s., waelbroeck c. (2004) compilation of planktic foraminifera census data, modern from the atlantic ocean. pangaea. doi: 10.1594/pangaea.227322 kucera m., weinelt m., kiefer t., pflaumann u., hayes a., weinelt m., chen m.-t., mix a.c., barrows t.t., cortijo e., duprat j., juggins s., waelbroeck c. (2005) reconstruction of the glacial atlantic and pacific sea-surface temperatures from assemblages of planktonic foraminifera: multi-technique approach based on geographically constrained calibration datasets. quaternary science reviews, 24, 951-998. locarnini r.a., mishonov a.v., antonov j.i., boyer t.p., garcia h.e. (2010) world ocean atlas 2009, volume 1: temperature. s. levitus, ed., noaa atlas nesdis 68, u.s. government printing office, washington, d.c., pp. 184. malmgren b. a., kucera m., nyberg j., waelbroeck c. (2001) comparison of statistical and artificial neural network techniques for estimating past sea surface temperatures from planktonic foraminifer census data. paleoceanography, 16(5), 520-530. doi: 10.1029/2000pa000562. martín-fernández j.a., thió-henestrosa, s. (eds.) (2016a) compositional data analysis: codawork, l’escala, spain, june 2015. springer proceedings in mathematics & statistics, 187. springer international publishing, new york (usa), pp. 209. martín-fernández j.a., thió-henestrosa, s. (guest eds.) (2016b) compositional data analysis. austrian journal of statistics, 45(4), pp.95. martín-fernández j.a., barceló-vidal c., pawlowskyglahn v. (2003) dealing with zeros and missing values in compositional datasets using nonparametric imputation. mathematical geology, 35(3), 253-278. martín-fernández j.a., hron k., templ m., filzmoser p., palarea-albaladejo j. (2015) bayesianmultiplicative treatment of count zeros in compositional datasets. statistical modelling, 15(2), 134158. mateu-figueras g., pawlowsky-glahn v., egozcue j.j. (2011) (pawlowsky-glahn v., buccianti a., eds). john wiley & the principle of working on coordinates, in compositional data analysis: theory and applications sons, ltd, chichester, uk, 29-42. ortiz j.d., mix a.c. (1997) comparison of imbrie-kipp transfer function and modern analog temperature estimates using sediment trap and core top foraminiferal faunas. paleoceanography, 12 (2), 175-190. pailler d., bard é. (2002) high frequency palaeoceanographic changes during the past 140000 yr recorded by the organic matter in sediments of the iberian margin. palaeogeography, palaeoclimatology, palaeoecology, 181(4), 431-452. pawlowsky-glahn v., egozcue j.j., tolosana-delgado r. (2015) modeling and analysis of compositional data. john wiley & sons, chichester, pp. 378. peña d., prieto f. (2001) multivariate outlier detection and robust covariance matrix estimation. technometrics, 43(3), 286-310. pflaumann u., duprat j., pujol c., labeyrie, l.d. (1996) simmax: a modern analogue technique to deduce atlantic sea surface temperatures from planktonic foraminifer in deep-sea sediments. 40 di donato v. et al. 41 paleoceanography, 11, 15-36. prell w.l. (1985) the stability of low-latitude seasurface temperatures: an evaluation of the climap reconstruction with emphasis on the positive sst anomalies, rep. tr025, 60 p., u.s. dep. of energy, washington dc, pp. 60. prell w., martin a., cullen j., trend m. (1999) the brown university foraminiferal data base. igbp pages/world data center-a for paleoclimatology data contribution series # 1999-027. noaa/ ngdc paleoclimatology program, boulder, co, usa. https://www.ncdc.noaa.gov/paleo/metadata/noaaocean-5908.html rasmussen s.o., bigler m., blockley s.p., blunier t., buchardt s.l., clausen h.b., cvijanovic i., dahl-jensen d., johnsen s.j., fischer h., gkinis v., guillevic m., hoek w.z., lowe j.j., pedro j.b., popp t., seierstad i.k., peder steffensen j., svensson a.m., vallelonga p., vinther b.m., walker m.j.c., wheatley j.j., winstrup m. (2014) a stratigraphic framework for abrupt climatic changes during the last glacial period based on three synchronized greenland ice-core records: refining and extending the intimate event stratigraphy. quaternary science reviews, 106, 1428. sbaffi l., wezel f.c., kallel n., paterne m., cacho i., ziveri p., shackleton n. (2001) response of the pelagic environment to palaeoclimatic changes in the central mediterranean sea during the late quaternary, marine geology, 178(1-4), 39-62. schlitzer r. (2018) ocean data view. http://odv.awi.de schönfeld j., zahn. r., de abreu. l. (2003) stable isotope ratios and foraminiferal abundance of sediment cores from the western iberian margin. doi:10.1594/pangaea.733303, supplement to: schönfeld, j., zahn r., de abreu l. (2003): surface to deep water response to rapid climate changes at the western iberian margin. global and planetary change, 36(4), 237-264. doi:10.1016/s0921-8181(02)00197-2 coda regression-based sst reconstruction ter braak c.j.f., juggins s. (1993) weighted averaging partial least squares regression (wa-pls): an improved method for reconstructing environmental variables from species assemblages. hydrobiologia, 269-270(1), 485-502. tolosana-delgado r., mckinley j. (2016) exploring the joint compositional variability of major components and trace elements in the tellus soil geochemistry survey (northern ireland). applied geochemistry, 75, 263-275. verboven s., hubert m. (2004) libra: a matlab library for robust analysis. https://github.com/duncombe/matlab/blob/master/ libra/rsimpls.m voelker a.h.l., de abreu l. (2011) a review of abrupt climate change events in the northeastern atlantic ocean (iberian margin): latitudinal, longitudinal and vertical gradients. in: rashid h., polyak l., mosley-thompson e. (eds), abrupt climate change: mechanisms, patterns, and impacts, geophysical monograph series (agu, washington d.c.), 193, 15-37. waelbroeck c., labeyrie l., duplessy j.-c., guiot j., labracherie m. (1998) improving past sea surface temperature estimates based on planktonic fossil faunas. paleoceanography, 13, 272-283. wallach d., goffmet b. (1989) mean squared error of prediction as a criterion for evaluating and comparing system models. ecological modelling, 44, 299306. ms. received: july 23, 2019 revised: january 25, 2020, accepted: january 26, 2020 available online: february 6, 2020 42 imp.pralong&reynard a proposal for a classification of geomorphological sites depending on their tourist value jean-pierre pralong & emmanuel reynard institute of geography university of lausanne, bfsh 2 dorigny ch-1015 lausanne switzerland jean-pierre.pralong@unil.ch, fax +41 (0) 21 692 30 75 abstract: j.p. pralong & e. reynard, a proposal for a classification of geomorphological sites depending on their tourist value. (it issn 0394-3356, 2005). this paper presents theoretical frameworks concerning the relationships between geomorphological landforms and processes and tourist and recreational activities. firstly, a global model connecting different components of these relationships is proposed. secondly, a particular model analysing how geomorphological landforms and processes are recognised and assessed as geomorphological sites in a context of tourist optimization and exploitation is developed. finally, an ensuing classification of geomorphological sites according to the use of their scenic, scientific, cultural and economic values is developed and illustrated by two case studies in the area of chamonix-mont-blanc (haute-savoie, france). riassunto: j.p. pralong & e. reynard, proposta per la classificazione di siti geomorfologici basata sul loro valore turistico. (it issn 0394-3356, 2005). l’articolo presenta tre quadri teoretici concernenti le relazioni tra forme e processi geomorfologici da una parte e attività ricreative e turistiche dall’altra parte. viene proposto prima un modello globale che mette in evidenza le differenti componenti di tali relazioni. e’ poi sviluppato un modello che analizza come vengono riconosciuti e valutati i siti geomorfologici in un contesto di valorizzazione e di sviluppo turistico. infine, viene sviluppata una classificazione dei siti geomorfologici secondo il loro valore scenico, scientifico, culturale ed economico, che viene poi illustrata con due esempi nella zona di chamonix-mont-blanc (alta savoia, francia). keywords: geomorphological sites, landscape, tourist offer, environmental impacts, natural risks, chamonix-mont-blanc. parole chiave: siti geomorfologici, paesaggio, offerta turistica, impatti ambientali, rischi naturali, chamonix-mont-blanc. il quaternario italian journal of quaternary sciences 18(1), 2005 volume speciale, 315-321 1. introduction the relationships between geomorphology and tourism may be analysed in four ways (reynard et al., 2003) at the interface of the natural and socio-economic systems: 1. first of all, geomorphology may be a tourist resource as part of the primary or original offer, that means as an element of the landscape or as a support for particular activities (e.g. climbing, canyonning, etc.). in this sense, geomorphology is a potential for tourist development, a part of the attraction of a tourist site; 2. geomorphology may also be part of the secondary or derived offer, when tourist infrastructures (e.g. museums, didactic paths), instruments (e.g. pedagogic booklets) or services (e.g. guided visits) are proposed for optimizing the original offer; 3. geomorphological processes may create changes on the tourist and recreational activities and infrastructures (processes, hazards and risks); 4. tourist activities and development may also create impacts on geomorphological processes and forms (e.g. soil erosion, slope instability or landform destruction). the aim of this article is mainly to consider the first three points and also to propose a theoretical reflection about the relationships between geomorphological landforms and processes and tourist and recreational activities. thus, three frameworks will be developed: the first one as a global model at the interface of the natural and socio-economic systems, the second one as a model of optimization and exploitation in a tourist context, the third one as a classification allowing to distinguish various types of geomorphological sites. as application examples, two case studies, related to the mer de glace and bossons glaciers, in the area of chamonix-mont-blanc (haute-savoie, france), will be presented. 2. studied area the chamonix-mont-blanc region (fig. 1) is situated in the arve valley (haute-savoie, france). the studied area concerns the river floor (chamonix area) and the right (massif des aiguilles rouges) and the left sides (massif du mont-blanc) of the valley. chamonix is a small town of 10.109 permanent inhabitants (census 1999) and is one of the largest ski resorts in france with 4.630.000 nights in 1999 (debarbieux, 2000). the major economic income of the region comes from tourism (skiing, golf, hiking). winter tourism is largely predominant, but new forms of summer tourism (trekking, biking) are developing, especially on the right side, beside various natural reserves (aiguilles rouges, carlaveyron). from a geological point of view, the area is situated in the helvetic domain, composed principally by gneiss and granites from the aiguilles rouges and the mont-blanc units (espace mont-blanc, 2001). these two units are separated by the chamonix area situated 316 j.p. pralong & e. reynard in the valley floor and composed principally by limestones, marls and sandstones. morphologically, the valley floor is covered by glacial and alluvial deposits (dorthemonachon, 1986) and the right side presents a lot of famous glaciers (tour, argentière, mer de glace, bossons, bionnassay) whereas the left side is practically deprived of ice and presents a lot of lakes and wetlands. 3. conceptual frameworks 3.1. general framework the figure 2 presents the relationships existing between geomorphology and tourism. tourist use of geomorphological landforms is made through the exploitation of geomorphological sites (1). geomorphological sites (or geomorphological assets) are defined by panizza & piacente (1993; 2003) and quaranta (1993) as geomorphological landforms (and processes) that have acquired a scenic, scientific, cultural/historical and/or social/economic value due to human perception or exploitation. in our case, they can be considered as geomorphological landforms and processes (e.g. geysers, active volcanoes, glaciers) that have acquired a certain tourist value and that are optimized and exploited for tourist purposes. in that sense, geomorphological sites may be considered as part of the original (or primary) tourist offer (2), which can be defined as the whole of natural, social, cultural or historical features that produce the attraction of a site (barras, 1987). according to debarbieux (1995), the primary offer depends on the localisation of the landforms and tourists have to go in situ in order to obtain satisfaction. in the case of geomorphology, the original offer can be completely based on the presence of a geomorphological landform or process. the tourist attraction of the small village of la-chaux-les-passavants in the french jura is for example only due to the presence of an ice cave. on the other hand, geomorphology may represent only one part of the tourist value of a site or a region. to take an example, the sugar loaf is not fig. 1 map of the studied region. chamonix-mont-blanc (haute-savoie, france). carta della regione studiata. chamonix-mont-blanc (alta savoia, francia). fig. 2 relationships between geomorphology and tourism: conceptual framework (adapted from panizza, 2003 and reynard et al., 2003). relazioni tra geomorfologia e turismo: quadro concettuale (adattato da panizza, 2003 e reynard et al., 2003). the only reason for tourists to visit rio de janeiro. however, geomorphology is not only limited to the original offer. a site may become a tourist destination only if amenities (infrastructures, services) are proposed to the visitors (barras, 1987), in order to facilitate their staying and access. thus, the secondary offer depends on the localisation of the population and tourists have to go ex situ in order to gain satisfaction (debarbieux, 1995). that is the derived (or secondary) tourist offer that may be unspecialised (e.g. parking, tourist office, hostels, roads and railways, etc.) or specialised (e.g. guided visits of a cave, presence of ski lifts in a winter resort, etc.). exploitation of geomorphology for tourism needs a specialised secondary offer (3), that means services (e.g. the presence of specialised guides), instruments (e.g. didactic boards, booklets, etc.) or infrastructures (e.g. transportation facilities for accessing specific geomorphological points, museum), that allow the exploitation (4) of the geomorphological sites. thus, these two types of offer create goods and services for material uses (hiking, climbing) and immaterial uses (relaxation, contemplation). relationships between geomorphology and tourism are not limited to the exploitation of a site, based on the original and derived offer. it is also a question of changes, risks and impacts. on the one hand, geomorphological processes may create changes on tourism (5), especially geomorphological hazards as landslides, avalanches, floods, rockfalls, etc., which create a relationship of risks (6). landslides or floods may for example destroy tourist villages. in this sense, tourist offer is in a situation of vulnerability (7). on the other hand, tourist activities create impacts on geomorphological processes and landforms (8) (panizza, 2003). impacts may be negative or positive and direct, induced or indirect (cavallin et al., 1994). 3.2. optimization, exploitation and transformation of geomorphological sites more precisely, in order to understand how the relationships between geomorphology and tourism act in the case of tourist development, a second conceptual framework is proposed in figure 3. according to this model, three steps are considered: optimization, exploitation and transformation. 317a proposal for a classification ... the onset is the existence of landforms and processes, expression of the earth’s history (1), as well as geological items. by human perception, geomorphology is considered (or not considered) as interesting for tourist purposes. thus, landscapes with a certain scenic, scientific, cultural/historical and/or social/economic value are optimized (2) as (tourist) geomorphological sites. the optimization depends of the degree of ecological (or geomorphological) sensibility of the tourist actors. when clear ecological ideas are expressed, optimization of geomorphological sites may happen. as a result of an ecological stimulation, tourist developers have two possibilities of action: protection (3) and/or exploitation (4). protection may happen when geomorphological sites are particularly vulnerable to human presence (e.g. some wetlands). geomorphological sites may also be exploited by the tourist industry1 and in that sense, they become the basis for tourist project conception and implementation (e.g. tourist caves, natural parks, didactic paths, etc.) by social stimulation. the project implementation creates a derived offer and the sustainability of the project depends of the type of management (5), following the use of geomorphological site values (see fig. 4). when the project is fulfilled, it may transform (6) the geomorphology and create direct or indirect impacts and induced hazards, that modify (in a positive or a negative way) the original processes and landforms, as a result of the economic stimulation. examples of transformations are the destruction of speleothems by the opening of caves to tourist visits (direct impact), the decreasing of the intensity of processes responsible for bad-lands formation in the case of the creation of protected areas and parallel reduction of livestock activity (indirect impact), and the increase of erosion (and successive landslides and debris flow hazards) due to the creation of ski tracks in mountain areas (induced hazards). these anthropic modifications are recorded as earth history memory and cultural witnesses (1). geomorphological landforms and processes of a second generation are therefore created and also new geomorphological sites in the sense of “tourist landscape evolution”. we assume that sustainable tourist use of geomorphological sites is reached when they produce sufficient financial incomes without negative environmental impacts and in base of a global consensus between the various actors (tourist actors, visitors, land owners, ngos, etc.). 1 note that protection and exploitation are not exclusive and may happen simultaneously: that is for example the case in natural and national parks. some areas or objects are strictly protected and sometimes human access is prohibited (e.g. the central part of a national park), whereas other parts are open for tourist visits. fig. 3 conceptual model describing the optimization, exploitation and transformation of geomorphology in a context of tourist development. modello concettuale che descrive la valorizzazione, l’uso e la trasformazione della geomorfologia in un contesto di sviluppo turistico. 318 4. classification of geomorphological sites the comprehension of the relationships evidenced in figure 2 and 3 allows the classification of geomorphological sites related to their optimization, exploitation and transformation due to tourist and recreational activities. a typology is therefore presented on figure 4. three categories are proposed: geomorphological sites (in the strict and the broader sense) and geomorphological mediums. according to panizza & piacente (1993), geomorphological sites are created by the contact between geomorphology and society, more precisely by the human perception of the value of geomorphological processes and landforms (a). with this process of optimization, they acquire a certain scenic, scientific, cultural/historical and/or social/economic value due to geological, geomorphological, historical and social factors. three groups of geomorphological sites are possible to be defined according to their value (b): 1. if the scenic, scientific or cultural value is concerned at least, without taking into account the economic value, geomorphological assets are defined as geomorphological sites in the strict sense. these items can be exploited or not (c). in this case, exploitation should be understood in terms of protection (total, with no possibility of human use), which means without any tourist activities in the surrounding of the landforms. therefore, if a geomorphological site (in the strict sense), according to its value, is protected, it becomes a protected geomorphological site. otherwise, it stays a geomorphological site in the strict sense. 2. if the scenic, scientific, cultural or economic value is considered, geomorphological assets are defined as geomorphological sites in the broader sense. in this case, landforms may have a tourist function if they are exploited (c) and sometimes protected (partially, with possibility of human use). thus, geomorphological sites (in the broader sense) are considered as a tourist and cultural resource (with extensive or intensive use). in this case, the question of sustainable management of geomorphology is essential; a toointensive use of geomorphology may dramatically change the value(s) of the resource and therefore its classification. 3. finally, if only the economic value is taken into account, geomorphological assets are simply defined as geomorphological mediums (framework, support), without any cultural value (e.g. rock glacier destroyed by ski tracks creation). in a context of tourist development, the exploitation of this type of feature (c) creates a tourist and economic resource (with extensive or intensive use); without exploitation, landforms can simply be called geomorphological mediums. for all the six classes, natural and/or anthropic transformation (d) may happen due to tourist activities and infrastructures or geomorphological processes and hazards. thus, tourist projects may affect the geomorphological sites and mediums, creating direct, indirect or induced impacts and risks (after cavallin et al., 1994). j.p. pralong & e. reynard fig. 4 classification of geomorphological sites according to their values in a context of tourist development. classificazione dei siti geomorfologici secondo i loro valori in un contesto di sviluppo turistico. 319 5. application examples the proposed classification (fig. 4) may be used for assessing sustainability of tourist use of geomorphological sites. two examples in the area of chamonix-mont-blanc (haute-savoie, france) are proposed here as application examples of differential exploitation: the mer de glace glacier and the bossons glacier (see fig. 1 for location). this comparison may be interesting to illustrate the range between a “tourist and economic resource (with extensive or intensive use)” and a “tourist and cultural resource (with extensive or intensive use)”. 5.1. case study 1: the mer de glace glacier the montenvers is the final station (1930 m) of a mountain train allowing the access to a wonderful viewpoint of the mer de glace glacier (40 km2) which is the third largest glacier in the alps in terms of volume (moreau & vivian, 2000) after the aletsch glacier (120 km2, valais, switzerland) and the gorner glacier (65 km2, valais, switzerland). from the montenvers station, the access to the mer de glace is possible by a cable car, very impressive in terms of visual impact, or on foot by an established path. the tourist attractions linked to the glacier (fig. 5) are a glacial cave (on the right), dug out each spring and autumn for numerous years because of the glacier advance, and an “ice garden” (on the left), a space of pedestrian discovery allowing a walk on a small part of the glacier. in practice, there is a fee to visit the two attractions, which require a daily maintenance in reason of the glacial flow and the abundance of visitors (sometimes near to 6.000 per day according to ballu, 2002). inside the cave, some rooms and elements of the traditional and regional mountain way of life have been carved out (kitchen, bedroom, bathroom, lounge). furthermore, it is possible to have a photo taken with beethoven, a st-bernard dog, with a little typical “chalet savoyard” behind it. the walk is regulated by path boards and ends with the cave. no explanation about the glacial dynamic or the ice structure is proposed during the visit. only a tourist leaflet about the cave and the montenvers site is available at the cash-box, indicated by a signal board only visible after the visit! concerning the “ice garden”, created in summer 2002, the access is possible by the bridge of the cave (fig. 5). then, tourists can walk freely on a part of the glacier measuring about 30 meters by 70 meters, where a lot of glacial forms and micro-forms are visible (erratic blocks, supraglacial moraine, ice sheets, dirt cones, moulin, etc.). as in the cave, there are no explanations (didactic paths, leaflets, or guided visits) about these landforms and the glacier. furthermore, advertisements about this spot are so limited (e.g. just a few brochures are available at the railway station in chamonix), that this new recreational offer is considered by some tourists as a work site! in comparison with the number of people visiting the cave, few people are interested by this spot which, on the one hand, is completely secure (presence of hazard signboards, carpet on the ice, barriers limiting the space) and on the other hand, has not had the entry price to the site enhanced since its making. so, for the actors managing the site (cave and “ice garden” included), the aim of the exploitation is not to give didactic and cultural information, but to welcome a maximum of people in a profit earning logic, especially during the period of high abundance (summer season). in this case, the primary offer (natural glacier) has become less important in terms of exploitation than the secondary offer (artificial glacial cave, “ice garden”, cable car, established paths). the tourist value of the glacier seems to have been emptied of its cultural and scientific values by the economic value in an intensive and “uncultural” manner. but the impacts on the glacier (and not in the surroundings) are not necessarily negative and give a new scenic and cultural value to the mer de glace. thus, by a tourist landscape evolution, these new values have created a geomorphological landform of a second generation. 5.2. case study 2: the bossons glacier the bossons glacier one of the rare large white glaciers in the alps (fig. 6) is the longest glacial slope in europe (3500 m), with a tongue flowing down to 1350 meters (mollier, 2000). a proposal for a classification ... fig. 5 mer de glace glacier with its numerous artificial caves and its “ice garden”. chamonixmont-blanc (haute-savoie, france). ghiacciaio del mer de glace con numerose grotte artificiali e il suo “giardino glaciale” chamonix-mont-blanc (alta savoia, francia). 320 one of the best tourist viewpoints to see the glacier is the “chalet du glacier des bossons” (1425 m) which is a little restaurant accessible by a little cable car or on foot from the bossons village. the restaurant is built on the left lateral little ice age moraine of the bossons glacier, and composed especially by erratic blocks of granite from the mont-blanc unit. in summer, the tourist attraction is the sight of the glacier front, which presents a wonderful white colour and frequent ice avalanches. from the “chalet du glacier des bossons”, two viewpoints (gratis) can be reached; the first one at 1425 meters and the second one at about 1460 meters. a didactic path (with 10 boards) allowing the glacial flow and history and movements of the bossons glacier to be understood embellishes the ascension to the last viewpoint. concerning the didactic path, the pathway is quite inclined and narrow. furthermore, each board is an unprofessional set-up of copies of scientific books (texts and pictures) and the content apparently interests visitors who go to the viewpoint. finally, some didactic leaflets about the bossons glacier, perhaps used as tools for guided and cultural visits, are available for sale at the kiosk of the restaurant. thus, this tourist attraction was not created for an important abundance – as is actually the ice cave of the mer de glace glacier and is an example of extensive and cultural site exploitation. furthermore, visits do not create vulnerability, risk and impacts in relation to the glacier, because it is impossible to access to its (dangerous) front and to walk on and into the glacier2. in comparison with the montenvers site, the bossons glacier is completely different in terms of slope, colour and features, and also in terms of the use of values, risk and impacts, because, for the actors managing the site, the aim of the exploitation is to deliberately propose another way to discover a famous glacier. here, the economic value of the glacial landform is used without trashing its scientific and cultural values. finally, in this case, the primary offer (natural glacier) remains more important in terms of exploitation than the secondary offer (restaurant, pathway, didactic path, viewpoint). the tourist landscape evolution is more natural and the glacier has not really acquired a new scenic and cultural value (no value renewal), and also remains a geomorphological landform of the first generation. 6. conclusion in the relationships between geomorphology and tourist and recreational activities, three main elements are necessary to be studied: geomorphological sites optimization and exploitation, environmental impacts and natural risks. our study has especially considered the first one. for an understanding of the tourist and cultural evolution of landscapes and geomorphological sites, a step-by-step reflection in terms of optimization, exploitation and transformation is relevant. the proposed classification, depending on the scenic, scientific, cultural/historical, and social/economic value of the geomorphological items is based on this idea and shows three categories of geomorphological sites (geomorphological sites in both the strict sense and the broader sense) and geomorphological mediums segregated by the economic value. this method may be interesting for analysing the differential uses of geomorphological sites. we assume that the degree and the modalities of exploitation follow the various values given to geomorphological sites; the comparison between the mer de glace (tourist and economic resource) and the bossons glaciers (tourist and cultural resource) is in this way exemplary. the two examples (both concerning the chamonix area, haute-savoie, france) show that the differences in terms of geomorphological sites optimization and exploitation, environmental impacts and natural risks are not well understood in the simple distinction between soft and hard tourism, because tourist landscape evolution is influenced by a single j.p. pralong & e. reynard 2 before the age of mass tourism, there was a tourist ice cave into the bossons glacier. now, some guided visits are organised for walking on the glacier. fig. 6 front of the bossons glacier from the viewpoint of the “chalet du glacier des bossons”. chamonix-mont-blanc (haute-savoie, france). fronte del bossons ghiacciaio visto dal “chalet du glacier des bossons”. chamonix-montblanc (alta savoia, francia). human perception of the actors. such evolution can create different generations of geomorphological sites, whose values evolve. finally, a statement can be done: when the geomorphological resource becomes just a consumable product, the exploitation seems to be more oriented on the secondary offer and the impacts and risks are higher. also, less the actors managing the geomorphological resource take the scientific and cultural value into account, more the renewal of the resource tends to decrease. acknowledgements we strongly acknowledge our colleagues geomorphologists at the institute of geography of the university of lausanne, especially n. summermatter, for their useful comments, as well as the helpful criticisms of two anonymous reviewers. references ballu y. (2002) drus, montenvers et mer de glace paris, hoëbeke, 141 pp. barras c.v. (1987) le développement régional à motricité touristique. de la région polarisée à la région-système documents économiques, 33, fribourg, editions universitaires, 285 pp. cavallin a., marchetti m., panizza m. & soldati m. (1994) the role of geomorphology in environmental impact assessment geomorphology, 9, pp. 143-153. debarbieux b. (1995) tourisme et montagne paris, economica, 107 pp. debarbieux b. (2000) bilan critique de 50 ans de tourisme à chamonix rapport n° 1, urbanisation aménagement, politiques touristiques, représentation sociales (http://www.sommets-tourisme.org). dorthe-monachon c. (1986) contribution à l'étude de la morphologie glaciaire de la vallée de l'arve (haute-savoie, france) : essai de reconstitution paléogéographique thèse de doctorat présentée à la faculté des lettres de l’université de lausanne, 249 pp. espace mont-blanc (2001) 50 sentiers à thèmes dans l’espace mont-blanc. haute-savoie, savoie, valais, vallée d’aoste, grenoble, glénat, 239 pp. mollier c. (2000) du glacier du mont-blanc au glacier des bossons yens, cabédita, 131 pp. moreau l. & vivian r. (2000) dans le secret des glaciers du mont-blanc grenoble, glénat, 95 pp. panizza m. (2003) géomorphologie et tourisme dans un paysage culturel intégré in: e. reynard, c. holzmann, d. guex & n. summermatter (eds.), géomorphologie et tourisme, actes de la réunion annuelle de la société suisse de géomorphologie (ssgm), finhaut, 21-23 septembre 2001, lausanne, institut de géographie, travaux et recherches, 24, pp. 11-20. panizza m. & piacente s. (1993) geomorphological assets evaluation zeitschr. für geomorphologie n.f., suppl. bd., 87, pp. 13-18. panizza m. & piacente s. (2003) geomorfologia culturale bologna, pitagora, 350 pp. quaranta g. (1993) geomorphological assets : conceptual aspect and application in the area of crodo da lago (cortina d’ampezzo, dolomites) first european intensive course on applied geomorphology, proceedings, modena cortina d’ampezzo 24 june 3 july 1992, pp. 49-60. reynard e., holzmann c. & guex d. (2003) géomorphologie et tourisme: quelles relations? in: e. reynard, c. holzmann, d. guex & n. summermatter (eds.), géomorphologie et tourisme, actes de la réunion annuelle de la société suisse de géomorphologie (ssgm), finhaut, 2123 septembre 2001, lausanne, institut de géographie, travaux et recherches, 24, pp. 1-10. 321a proposal for a classification ... impaginato baioni ddrraaiinnaaggee nneettwwoorrkk aanndd eenneerrggyy rreelliieeff ooff mmaaddeeiirraa iissllaanndd ((ppoorrttuuggaall)):: pprreelliimmiinnaarryy nnootteess ddaavviiddee bbaaiioonnii11,, ddoommiinnggooss rrooddrriigguueess22 && ggiiuulliiaannoo ggaalllleerriinnii11 1università degli studi di urbino,campus scientifico, istituto di dinamica ambientale loc. crocicchia, 61029 italy. 2c.c.b.g. universidade da madeira,campus da penteada, 9000 funchal, portugal. abstract a geomorphological study, integrated with satellite imagery analysis, has been carried out in the madeira island to identify the influence of neotectonics on the landscape. drainage network and energy relief are the main geomorphological indexes used to identify recent uplift. the drainage anomalies and areas of high relief energy, often coincident, are not explainable by means of the local meteoclimatic conditions. some peculiar anomalies, such as hook-like shapes and torsions of the network, distributed on lineaments that coincides with those detectable from satellite images, indicate a differential direction of central block, symptom of a prevailing tectonics of uplift with a probable horizontal component. riassunto reticolato idrografico ed energia del rilievo dell’isola medeira (portogallo): note preliminari. e’ stato affrontato uno studio geomorfologico preliminare integrato con analisi di immagini da satellite nell’isola di madeira per valutare l’influenza della neotettonica sulla morfologia. i principali indicatori per identificare il recente sollevamento si sono rivelati il reticolo idrografico e l’energia del rilievo. le anomalie del drenaggio e le aree ad alta energia del rilievo sono spesso coincidenti e sembrano non essere condizionate dalle condizioni meteoclimatiche dell’isola e risultano essere in relazione ad alcune lineazioni tettoniche evidenziate nelle immagini da satellite. tale situazione morfologica indica un sollevamento differenziale del blocco centrale con una probabile componente orizzontale. keywords: drainage network, energy relief, neotectonics, madeira island. parole chiave: reticolo di drenaggio, energia del rilievo, neotettonica, madeira il quaternario italian journal of quaternary sciences 1155(2), 2002, 271-274 11 iinnttrroodduuccttiioonn a stream channel network analysis has been carried out on the existing cartography available at the 1:50.000 scale (i.g.a. madeira, cf. table attached). on the basis of the detected patterns, network anomalies, that were not justifiable by means of terrain lithology and structural tectonics, were identified. concurrently, the map of relief energy was derived so that further morphotectonic information via an integrated analysis could be obtained. 22 ggeeoollooggiiccaall aanndd ggeeoommoorrpphhoollooggiiccaall sseettttiinngg madeira island is located in the north atlantic, 900 km southeast of lisbon. it has an area of 728 km2 and 265000 inhabitants. it is of volcanic origin, miocene period, and considered as the present location of a hotspot that also originated the desertas islands (which belong to the same volcanic complex), porto santo island and the seamounts seine, unicorn, ampere, coral patch and ormond. madeira has in its central region swarms of vertical dikes, normal faults, graben structures and cinder cones, parallel to the long axes of madeira (ew) an area characteristic of volcanic rift zones (biancotti, 2001; geldmacher & hoernle, 2000). lithostratigraphically the geology of madeira island can be divided into three units. the first, a basal unit, was formed during the late miocene to pliocene and is mainly formed by volcanic breccias and pyroclastic deposits. the second, the middle unit, is composed by basaltic lava flows and formed from the pliocene to the pleistocene. the third, the upper unit, consists of scoria cones and intra-canyon lava flows formed during the renewed volcanic stage of evolution of the island (geldmacher & hoernle, 2000). the orography is characterized by a strong relief with altitudes that reach 1860 m, the average altitude is of 700 m. average rainfall values vary from 600 mm in the southern coast to 3000 mm in the areas of high altitude. the lithology and the structure of the volcanic body, which originated the island itself, mainly influence the morphology of madeira island. climatic changes, the last periods of quaternary volcanic activity (mata, 1996), neotectonics and sea level variations have played an important role in the definition of the morphological configuration. in addition, intensive anthropic impacts, essentially concentrated on coastal areas, have caused further changes to the landscape. the most active processes are coastal erosion (the northern shore faces ne and n winds, hence it is affected by active marine ero272 d. baioni, d. rodrigues & g. gallerini f ig .1 d ra in ag e sy st em o f m ad ei ra is la nd (i .g .a . m ad ei ra , 1 :5 0. 00 0 m od ifi ed a nd re du ce d) . s om e ne tw or k an om al ie s an d m ai n dr ai na ge p at te rn ty pe s ar e hi gh lig ht ed . e ne rg y re lie f m ap (t op ri gh t). s is te m a di d re na gg io d el l'i so la d i m ad ei ra ( i.g .a . m ad ei ra , 1: 50 .0 00 m od ifi ca ta e r id ot ta ). s on o ev id en zi at e al cu ne a no m al ie d el r et ic ol o e le p rin ci pa li tip ol og ie d ei p at te rn d i d re na gg io . c ar ta de ll' en er gi a de l r ili ev o (in a lto a d es tr a) . 273drainage network and energy relief ... sion whereas the southern shore results to be more protected), run off erosion and chemical weathering of pyroclastic lithologies. the drainage network is heavily incised and vertical erosion dominates. 22..11 ddrraaiinnaaggee nneettwwoorrkk aannaallyyssiiss the study of the drainage network (fig.1) indicates at least 2 main patterns, parallel diverging and dendritic ones, and reveals that generally the existing basins are distributed in a centrifugal manner around the central relief. the ribera de janela basin represents an exception; it develops by overlapping in an anomalous way transversally to the dominant drainage direction. it is likely that such a basin represents a more recent formation compared to the surrounding drainage system. a significantly diverging drainage pattern extends in the area south of the main divide, between p.ta do sol and p.to moniz (wnw part), in the area between funchal and machico (sse part) and in the area north of the main divide between the arch of st. gorge and faial. diverging nets are typically derived from previous alluvial fans and/or pediment surfaces (cfr. nesci & savelli, 2001). where it is found, diverging drainage developed independently both from the geological and structural setting and from the age of terrain. sometimes together with diverging patterns a parallel net prevail, especially in the sw coast sector of the island. parallel streams in this diverging net could be derived from the ancient topographic configuration on a more pronounced slope. a dendritic-feathered pattern prevails in the central part of the island, it generally develops on rocks of uniform sedimentary units. this pattern shows a very high drainage density. anthropic modifications affected the channel network around densely populated and intensively cultivated coastal areas. a detailed analysis has allowed the identification of network branches characterised by an anomalous pattern (torsions, elbow-like, rectilinear and barbed segments). the occurrences of such anomalous branches, that can be correlated to lineaments (fig.1, fig.2), have been interpreted as tectonic constraint of the network. in fact, they are not justifiable by other causes (selective erosion, slope gradients, anthropogenic factors, etc.). this is also confirmed by the exceptional correspondence that exists between the majority of the lineaments and those detectable from satellite image interpretation (cf. fonseca & alii,1998 a and b) 22..22 rreelliieeff eenneerrggyy aannaallyyssiiss the relief energy analysis has been conducted by extraction of an energy map. topographic maps (1:50.000 scale) of the madeira island have been divided into 2 by 2 cm. squares (equivalent to a linear scale of 1.000 m on the ground) (cfr. klein & antun, 1983). subsequently the squares have been numbered according to an orthogonal co-ordinate system. for every square minimum and maximum elevation have been estimated using contour lines as references (equidistance equals 25 metres). the relief energy has been obtained by subtracting the minimum from the maximum value. the obtained map presents two areas of high relief energy. one extends essentially on the central region of the island, occupied by the central massif, the other is located in the northern part between p.to moniz fig.2 spot image of madeira island (project corine land cover ilha da madeira.cnig. secretaria regional do equipamento social.governo regional da madeira) immagine da satellite dell'isola di madeira (project corine land cover il ha da madeira.cnig. secretaria regional do equipamento social.governo regional da madeira) 274 and p.ta delgata, where values are certainly enhanced by the ongoing erosion due to its peculiar exposition. to highlight the spatial similarities among all high relief energy areas and the high drainage density, all the most significant anomalies of the drainage network are concentrated in these high relief energy areas. 33 ccoonncclluussiioonnss this study aimed at highlighting the presence of some landscape anomalies in specific areas of madeira island. these areas are separated by main lineaments that are easily detectable from satellite imagery (fig. 2). the diverging/parallel pattern, that corresponds to low energy relief zones, indicates the presence of a palaeo-landscape that has been partially reshaped by erosive processes only in the south and north-east parts of the island. when compared to others, these sectors seem to have been subjected to a minor uplift. in contrast, the central part of the island shows a dendritic drainage pattern with high drainage density and many anomalous tracts of the rivers (captures elbows, torsions, barbed rivers, etc.). this generally indicates drainage in evolution. anomalous trend of the divides shows strong headwater regressive erosion with a clear tendency to hillslope retreats. the high-energy relief is found just in this sector, even though in places (e.g. coastal area) such a situation can result from the high denudation rate of the northerly facing basins. the north-west part of the island is characterised by the anomalous basin of ribera de janela river elongated in nwse direction. the shape of this basin that shows a very low energy relief probably represents the response of this mountain sector to a very recent evolution. this assumption is justified by the anomalous length of the stream when compared to all rivers of the island and by the incomplete erosion of the palaeosurfaces of plan de serra, which is most likely, a remnant of ancient landscape. in conclusion, we identify several areas that present a different tectonic behaviour by means of the geomorphological analyses reported above. in particular, the central area appears to be the most affected by dynamics of uplifting whereas lateral areas seem to be substantially stable or however interested by minor uplifting. torsions of the stream channels in correspondence of the two principal nwse lineaments, might be due to different horizontal components: clock-wise movements in the southern portion and anti clock-wise movements in the northern one. aacckknnoowwlleeddggeemmeennttss our thanks to prof. o. nesci for useful discussions. rreeffeerreenncceess carvalho a.m.g. & brandao j.m. (1991) geologia do arquipelago da madeira. museu nactional de historia natural (univ.lisboa), pp. 170. fonseca p.e., mata j. & domingos r.(1998a) preliminary data on tectonic lineaments from madeira island. geologos revista do dept.de geol.da fac.de cien.da univ.do porto 2, 89-90 fonseca p.e., mata j.& munha j.(1998b) tectonic lineaments from madeira island evidenced from satellite image analysis and preliminary geological data. actas do v congresso nactional do geologia, lisboa comun.inst.geol.min., 84(1), 101-104. geldmacher, j. & hoernle, k., (2000). the 72 ma geochemical evolution of the madeira hotspot (eastern north atlantic): recycling of palaeozoic (£ 500 ma) oceanic crust. earth planet. sci. lett. 183,. 73¯92. klein v. & antun s. (1983) a morphostructural analysis of the adriatic seabed relief energy on the basin of a bathymetrical map on the scale 1:750.000. bulletin of the inqua neotectonics commission, 6,40. mata j. (1996) petrologia e geoquimica das lavas da ilha da madeira:implicacoes para os modelos de evolucao mantelica.tese de doutoramento (univ.lisboa), pp. 471 nesci o. & savelli d. (2001) diverging drainage in the umbria-marche apennines (central italy). convegno "uplift and erosion: driving processes and result ing landforms: dynamic relations between crustal and surficial processes", september 20 and 21, certosa di pontignano (siena). (abstract) d. baioni, d. rodrigues & g. gallerini ms. ricevuto il 20 ottobre 2002 testo definitivo ricevuto il 4 febbraio 2003 ms. received: october 20, 2002 final text received: february 4, 2003 imp.bini glacial landforms in the apuan alps (tuscanyitaly): features in danger of extinction monica bini phd student, università di bologna. research carried out at dipartimento di scienze della terra, università di pisa, email: bini@dst.unipi.it abstract: m. bini, glacial landforms in the apuan alps (tuscany italy): features in danger of extinction. (it issn 0394-3356, 2005). the remaining glacial landforms of the apuan alps are of great scientific interest, but they are not adequately exploited, and even their very conservation is in peril, despite the protective limitations imposed by the regional park of the apuan alps. from a first analysis of remaining glacial landforms, two sites in particular have been identified as being worthy of special attention, for different reasons: the arni moraine and the glacial complex of campocatino. riassunto: m. bini, forme glaciali delle alpi apuane (toscana-italia): elementi a rischio di estinzione. (it issn 0394-3356, 2005). i resti glaciali delle alpi apuane hanno un grande interesse scientifico, ma non sono adeguatamente valorizzati, e addirittura è messa in discussione anche la loro conservazione, nonostante i vincoli imposti dal parco delle alpi apuane. da una prima analisi dei resti glaciali apuani, sono emersi tra gli altri due siti che meritano per ragioni diverse una particolare attenzione: la morena di arni e il complesso glaciale di campocatino. keywords: apuan alps, glacial landforms, geomorphosites. parole chiave: alpi apuane, morfologia glaciale, geomorfositi. il quaternario italian journal of quaternary sciences 18(1), 2005 volume speciale, 175-178 1. introduction the glacial landforms of the apuan alps, dating to the last climatic change of the pleistocene, deserve attention due to their importance in palaeogeographic reconstructions and for the study of glacial processes in the apennines. it is particularly interesting to look into the reasons governing the extension of the apuan glaciers given the altitude of the chain, no higher than 2000 m, the short distance from the sea (10-15 km) and its latitude (44°n) (fig. 1). the apuan glacial remains have very interesting characteristics. in fact, in the apuan chain there are the lowest deposits in the whole of the apennines. the reasons for this are probably to be found in the particular climatic regime of the area, above all its high rainfall, which at the high altitudes reaches 4000 mm of rain per year. this seems to have favoured the formation of glacial deposits at low altitudes. the würm period of permanent snowcover in the apuan alps has been calculated for the internal areas at around 1200-1300 m and this is the lowest recorded in the apennines chain (braschi et al., 1986). palaeogeographic reconstructions have shown that during the last glaciation, on the north eastern sides of the apuan alps there must have been at least 9 glaciers, which extended down as far as the garfagnana piedmont plain. in particular, by 1912 merciai had already identified the presence of the following 9 glaciers: those of orto di donna, gramolazzo, pisanino, campocatino, tambura, arni, altissimo, corchia and pania secca, all on the eastern side. various traces indicating small glaciers on the seaward side were also found (federici, 1981). these are mainly erosional landforms, given that high slope gradients have prevented the conservation of extensive moraine deposits. however, very little remains of the apuan glacial landforms. with time, evidence of their presence has been eliminated by fluvial-glacial or fluvial processes, by the karst processes particularly influential in the apuan area, given the lithology and rainfall regime, but also by the action of man with the centuries-old marble quarrying activities. the latter have destroyed the glacially-modelled slopes, removing both erratics and moraines. it is for this reason that the few remaining forms should be carefully safeguarded. from an initial survey on apuan glaciation, two sites in particular have been identified which deserve, for different reasons, special attention and require a clear policy of sustainable conservation. the first site is that of the arni moraine, which, despite its importance in the history of glacial studies in the apennines, is today in a serious state of degradation. the second is the glacial complex of campocatino, which, on the other hand, is well conserved, easy to interpret and particularly suitable for educational activities associated with glacial processes. 176 m. bini 2. the arni moraine the arni moraine (fig. 2) is a typical example of the degradation undergone by the apuan glacial landforms. it appears in an impressive section near the village of arni at an altitude of 920 m. the deposit reaches a height of 50 m starting from the bed of the turrite secca torent and is made up of a chaotic mass of marble pebbles with subordinate presence of also phyllites and verrucan schists. in the complex there is a well-cemented medium-to-finely grained matrix, and in some pebbles the typical glacial striations can be seen. the moraine was the first glacial deposit of the apennines to be described in 1872 simultaneously by cocchi and stoppani. the two geologists identified the moraine separately and such was the reciprocal respect between the two that neither of them claimed for himself this important discovery. in particular, stoppani described it as a: “…morena composta quasi esclusivamente da massi di bianco saccaroide, roccia che costituisce quasi per intero le montagne dell’ingiro della valle. gli scisti talcosi, talora quarziferi, che si scoprono associati ai calcari ai limiti della morena e si levano verso monte altissimo si scoprono in frantumi nel detrito morenico. alla presenza di queste rocce si deve certamente la striatura dei massi calcarei che si presentò nel modo più evidente alla estremità occidentale precisamente ove dipende dal m. altissimo”. in order to understand how important the discovery of the arni moraine was in the history of glaciation in the fig. 1 the study area at the scale of 1:65.000 (enlarged from foglio 96 –massaof carta topografica d’italia, igm). l’area di studio scala 1:65.000 ( ingrandimento del foglio 96 massa della carta topografica d’italia –igm-). apennines, it is enough to read the few lines that follow: “l’esistenza d’un ghiacciajo nella val d’arni può ritenersi come indizio sicuro dello sviluppo del terreno glaciale nelle apuane, principalmente sui versanti settentrionali e nei bacini dipendenti da montagne più alte di quelle della val d’arni. non manca pure di acquistare valore di somma probabilità d’opinione da me già espressa nel 1865 che antichi ghiacciai debbano scoprirsi nelle regioni più elevate dell’appennino centrale, principalmente nelle dipendenze del gran sasso d’italia, il quale avendo 2899 m di elevazione, supera del doppio quella del m. altissimo, che è di soli 1590.” (the presence of the arni moraine was considered by stoppani to be important evidence suggesting the existence of glaciers elsewhere in the apennine chain). cocchi, from the lunigiana area, who describes the moraine as being a little less extensive than stoppani, remarks how the deposit “…lungi dall’essere isolato è anzi frequente ripetendosi in tutte le vallate principali delle nostre pania”, in this way reinforcing the opinion of stoppani regarding the probable widespread distribution of this type of deposit in the apennines. the arni moraine is at a higher altitude compared to the other apuan moraines, probably because the glacier which generated it was the only one facing south. other small ice masses extended down from monte fiocca towards south, west and south east, whilst a larger mass, which was the largest part of the arni glacier, extended southwards from passo sella and from monte macina. along the channel of burrone at 1050 m we can see some scarce morainic detritus, but the area, as is often the case in this district, has been so disturbed by the marble quarrying that almost all the remaining deposits have been obliterated. the arni moraine remains the only deposit that is still visible and offers a particularly detailed section which can be 177glacial landforms in the ... used to illustrate the salient features of glacial and fluvio-glacial deposits and their interrelationships. the site of the section is easily accessible by car and there are very suitable facilities nearby, such as hotels, restaurants and bars. its exploitive characteristics, together with its high scientific and historical value, make it an ideal geosite. today however the moraine is in a state of serious degradation. to make things worse, close by there is an illegal dumping site and a water purification plant has recently been built in the area. despite the protection afforded by the park of the apuan alps there is no corresponding sustainable exploitation of the site. in fact, there is basically no recognition of the inherent value of the site, either in the local community or among the few tourists who visit the area. unfortunately, it is effectively an area better known for having been ruined by the quarrying activity. recovering and sustainably developing this site would mean a significant contribution to re-evaluation of the area. 3. the glacial complex of campocatino the glacial complex of campocatino (fig. 3) is of great educational interest and is an area recognised as important by the local community, and which is the destination of a certain number of tourists, also because of its location near the well-known medieval village of vagli. campocatino is a veritable jewel in the park of the apuan alps. it is a small glacier, 1 km long, which originated from the monti tombaccia and roccandagia, and extended down to a small glacial hollow with a length of 500 m and width of 250 m, creating a double circular moraine with the typical arched shape in its frontal part (paci, 1935; tongiorgi & trevisan, 1940). the two moraines, about ten metres high and 500 m long, are almost exclusively made up of marble from m. roccandagia. the matrix is scarce, particularly in the external circle, due to the limited transport of these materials. the shape is typical and the deposits, despite their small size, are easy to interpret and very well conserved. using the moraine it is possible to reconstruct, something quite rare in the apuan alps, various glacial stages or frontal oscillations of the glacier. the landscape is made even more impressive by the presence of a small pastoral village, with small stone-built alpine huts standing on the moraines and once used by the shepherds coming from the lower valley of vagli di sopra and neighbouring areas during transhumance. this human element, which reflects one of the typical activities of the apuan area, particularly in the garfagnana valley, adds a cultufig. 2 frontal view of the arni morain deposit. notice the general degrade of the area with poor potential preservation. vista frontale del deposito morenico di arni, da notare il generale degrado dell’area. 178 ral historical value to the natural resource. another anthropic element of a certain historical importance is the hermitage of st. viviano, which can be reached in only 30 minutes on foot. apart from its particular geological, geomorphological and historical-cultural features, the area is also of great interest as regards fauna and flora. in fact, there are rare and endemic species, so much so that the area has been a lipu (italian league for the protection of birds) reserve since 1991. although size is usually an important criterium in recognising the quality of a geomorphosite, in this case it is precisely the fact of being a miniature glacier which makes it possible to find a combination of erosional landforms, like the cirque in the higher part of monte roccandagia, and depositional forms which are easy to interpret and difficult to find elsewhere in a limited area. it is these factors that determine its high educational value. in the plan of the regional park of the apuan alps, the area of campocatino is rightly designated as a unique landscape which combines botanical and geomorphological features with a high historical-cultural value of a still very well conserved rural settlement. the presence of suitable tourist infrastructures makes this site particularly suitable for sustainable exploitation. however, locally there is still essentially a lack of an interpretative process and realisation of the area's intrinsic value. 4. conclusions from an initial analysis of the apuan glacial landforms we can identify two sites worth safeguarding and exploiting. one is the arni moraine, which is currently in a state of degradation and lacking in any form of interpretative initiative or sustainable development of the local landscape. the other site is the glacial complex of campocatino, which, due to its clearly interpretable forms, its state of conservation and its added ecological and historical-cultural value, is an ideal geosite. the easily accessible positions of the two sites make them particularly suitable in terms of educational and informative initiatives, without having to modify the existing physical infrastructure, therefore with a need for limited investments. it is without doubt that a suitable exploitation of these two resources would have positive knockon effects on the economy of not only the park, but also of the local communities. it could contribute to promoting sustainable tourism and a new environmental recognition which, in turn, could generate new forms of protection and respect and consequently long-term conservation of these resources. references braschi s., del freo p. & trevisan l. (1986) ricostruzione degli antichi ghiacciai sulle alpi apuane atti soc. tosc. sc. nat., mem., serie a. 93, pp. 203-219. cocchi i. (1872) del terreno glaciale delle alpi apuane boll. del r. com. geol. vol. 3 n. 7-8. federici p.r. (1981) the quaternary glaciation on the seaward side of the apuan alps riv. geogr. it., an. lxxxviii , fasc. 2. merciai g. (1912) fenomeni glaciali delle alpi apuane atti soc. tosc. sc. nat. mem. vol. 28, pp. 70-89. paci m. (1935) revisione dei terreni morenici quaternari delle alpi apuane atti soc. tosc. sc. nat., proc. verb., 44, pp. 13-30. stoppani a. (1872) sull’esistenza di un antico ghiacciaio nelle alpi apuane rendic. ist. lombardo sc. lett., 5, pp. 1-7 tongiorgi e. & trevisan l. (1940) aspetti glaciali e forestali delle alpi apuane durante l’ultima glaciazione atti soc. tosc. sc. nat. proc. verb., 49 (3), pp. 3-10. fig. 3 overview of the glacial complex of campocatino with the frontal moraine (dashed line) and the backward humid depression. vista panoramica del complesso glaciale di campocatino, con la morena frontale (linea tratteggiata) e la retrostante zona umida. m. bini amq abs toti bertini saccom 199-203.pub available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 199 203 mediterranean pollen stratigraphy across the early-middle pleistocene boundary francesco toti, adele bertini dipartimento di scienze della terra, università degli studi di firenze, firenze, italy corresponding author: f. toti <francesco.toti@unifi.it> abstract: the mediterranean preserves a detailed history of the past climate cycles and brings together an elevated number of gssps. in the recent years, the efforts to establish the gssp for the middle pleistocene in the mediterranean have received substantial assistance from palynology. in the present paper, we compare pollen data from two successions both encompassing the early-middle pleistocene boundary: the montalbano jonico section and odp core 976. other coeval mediterranean and extra-mediterranean records were evaluated to corroborate the climate structure and stratigraphy revealed across the stage boundary. keywords: early-middle pleistocene, gssp, mis 19, pollen, mediterranean, montalbano jonico, odp 976 1. introduction southern italy is a ‘hot-spot’ for the neogene and quaternary stratigraphy hosting, at present, four ratified global boundary stratotype sections and points (gssps; http://www.stratigraphy.org/index.php/icsgssps). the relevance of the southern italian sedimentary archives is enhanced by their rich biostratigraphical content (e.g. calcareous plankton, pollen, ostracods, dinocysts) as well as by the continuous nature of the successions, thereby promoting reliable reconstructions and correlations. pollen records from southern italian sites illustrate the impact of the quaternary glacial-interglacial (g-ig) cyclicity in the central mediterranean (e.g. combourieu nebout et al., 1995, 2015; joannin et al., 2008; bertini et al., 2010, 2015), as revealed by changes in the relative abundances of steppe vs thermophilous forest communities. once pollen records are complemented by other proxy data (e.g. stable isotopes, calcareous plankton), they are highly relevant for the studies consecrated to the establishment of a gssp. the marine succession of montalbano jonico (mj), cropping out in the basilicata region (40°17’n and 16° 34’e, fig. 1), contains the early-middle pleistocene boundary, which approximates the matuyama-brunhes (m/b) boundary and marine isotope stage 19 (mis 19) (channell et al., 2010). the mj section has been under consideration for the gssp of the middle pleistocene subseries/subepochs (marino et al., 2016), after a large number of studies emphasizing the richness of its biological and inorganic proxies, representative of both marine and terrestrial environments (e.g. stable isotopes, calcareous plankton, ostracods, pollen, …). the pollen investigation performed at mj highlights a peculiar structure of climate variability during the mis 19 interglacial complex (e.g. bertini et al., 2015; maiorano et al., 2016). many features of this interglacial are a benchmark for correlations at both regional and global scale, especially regarding the climate records derived by the pollen spectra (bertini et al., 2015; maiorano et al., 2016). below we present a summary of the main palynological phases and events described at mj at the early-middle pleistocene boundary and their significance at regional and extra-regional scale. our analysis emphasizes the correlation between mj and deep-sea cored successions (odp site 976) to enhance the importance of the palynology in the frame of the quaternary stratigraphy. 2. materials and methods palynological data were collected from two marine successions in the mediterranean (fig. 1): the mj section (southern italy) and odp core 976 (alboran sea), both covering mis 19. the strategy of analysis and the complete pollen dataset from the two successions were developed in the frame of a phd thesis (toti, 2018) and also in dedicated papers (bertini et al., 2015; marino et al., 2016; toti et al., in preparation), to which the reader is referred. the chronology of the successions was developed adopting the same orbitally-driven δ18o variability observed in the mediterranean during the last deglaciation (simon et al., 2017; nomade et al. submitted; toti et al., in preparation), on the assumption that mis 1 and mis 19 are very close orbital analogues (e.g. tzedakis et al., 2012; yin & berger, 2012). the timing of the m/b reversal is revealed, at mj, by the peak of 10be/9be, which corresponds to the collapse of the geomagnetic dipole (e.g. simon et al., 2017). in fig. 2 we present selected pollen curves obtained by analyzing 59 samples (mj section) plus 104 samples (odp site 976) that span the interval from late mis 20 to the end of mis 19 (ca. 800-755 ka). percentages of pollen taxa were normalized to a sum excluding pinus, because this taxon is over-represented in both successions. the pollen temperature index (pti), given by the ratio between mesothermic (e.g. deciduous quercus, https://doi.org/10.26382/aiqua.2018.aiquaconference carpinus spp.) and steppic pollen (artemisia, ephedra and amaranthaceae) (suc et al., 2010; joannin et al., 2011) permits to summarize the main climate variability. 3. results pollen records from the mj section and odp site 976 provided a reconstruction of the vegetation and climate in the central and western mediterranean across the early-middle pleistocene boundary (toti, 2018). at both studied locations, the mis 20-19 transition is characterized by a dramatic expansion of steppe and semi-desert taxa, suggesting very (cold-)dry conditions on land. this phase ranges from ca. 795 to 785 ka and approximates the phase of maximum ird deposition in most of the north atlantic sites (fig. 2). the increasing values of the polar water foraminifer n. pachyderma (left-coiling) in the north atlantic (wright & flowers, 2002; alonso-garcia et al., 2011; sánchez goñi et al., 2016) and in the mediterranean (marino et al., 2015; maiorano et al., 2016) also testifies a prominent influence of cold melt-water at the mid-latitudes. during a 5 kyr-long interval centered at 790 ka the regional pollen signal is marked by a large expansion of cupressaceae (fig.2). since 784 ka, the pollen records suggest a major expansion of temperate deciduous taxa, consistent with the main terrestrial interglacial, dominated by relatively high precipitations and temperatures. repeated phases of decline/expansion of the temperate forest taxa are, however, evidenced by the pti curve between 784 and 773 ka. although the different samples resolution at the two sites prevents unambiguous correlations among the temperate deciduous taxa curves, pti can be used to trace at least three short-lived phases of relative precipitation-temperature increase, having regional significance: a1 (ca. 783 ka), a2 (ca. 778 ka) and a3 (ca. 774 ka). such phases seem not to be expressed with the same magnitude at the two sites, probably because of the modulation by some local factors. nonetheless, their systematic pattern within mis 19 suggest that they are a robust feature of the full interglacial phase in the terrestrial realm. at 773 ka, a shortterm, low-amplitude expansion of steppic and semidesert taxa traces the end of the mis 19 full interglacial at both sites. cold conditions are also documented by the first episode of increased n. pachyderma (leftcoiling) percentages and ird deposition in the records from the north atlantic ocean (wright & flowers, 2002; alonso-garcia et al., 2011; sánchez goñi et al., 2016). the analysis of the uppermost part of the sequence reveals higher precipitations and temperatures during two intervals centered around 770 ka (event b) and 762 ka (event c). these intervals are terminated by abrupt cooling-drying phases as well as by concomitant episodes of ird deposition and polar melt-water influx (fig. 2). 4. discussion and conclusions mj exhibits an extraordinary exposure of marine deposits, accumulated in a relatively short time-span (450 m in ca. 600 kyr, from mis 37 to mis 17: ciaranfi et al., 2010 and references therein) and without major sedimentary disturbances such as hiatuses and tectonic deformations. calcareous plankton (foraminifers and nannofossils) records provided one of the primary tools for long-range correlations (e.g. ciaranfi et al., 2010). in order to improve the frequency of chronologically significant events and the overall quality of palaeoclimate reconstructions, the previous data were fruitfully integrated by concomitant registrations, including stable isotopes and pollen (marino et al., 2016). within this framework, the pollen results turned out to be a versatile tool for monitoring the assumed chronostratigraphic 200 fig. 1 location map showing the study successions (mj: montalbano jonico; odp site 976) and other sites cited in the text. toti f., bertini a. correlations. the accuracy of pollen-derived reconstructions relies on the relatively large sensitivity of vegetation to climate perturbations (e.g. tzedakis et al., 1997). in the mediterranean context, pollen results from mj are effectively supported by those obtained from odp site 976, especially in terms of magnitude of long-term changes and timing of suborbital-scale features (fig. 2). specifically, both pollen spectra suggest the development of an open-dry vegetation during mis 20, including a shorter interval marked by the spread of cupressaceae. pollen spectra also highlight strong similarities regarding the main interglacial phase of mis 19 (ca. 784-773 ka) and the following stadial-interstadial oscillations (fig. 2). it is worth mentioning the presence of close similarities in the pollen record from iodp site u1385 atlantic margin of iberia (sánchez goñi et al., 2016), and in the δ18o record from the sulmona lacustrine basin, southern italy (giaccio et al., 2015). coeval records from even more distant sites, like those located in the high-latitude north atlantic (e.g. iodp u1314, ferretti et al., 2015; odp 980, wright & flower, 2002; odp 983, kleiven et al., 2011; channell et al., 2010) corroborate the above described climate variability. within the mis 19 full interglacial, the mj pollen record describes at least three millennial-scale forest expansions (a1, a2 and a3), which are also expressed at odp site 976 (fig. 2). event a3, in particular, should be emphasized as it approximates the timing of the main peak of 10be/9be which, in turn, reflects the geomagnetic field weakening associated to the m/b reversal (simon et al., 2017). the latter event is the main criterion for the definition of the middle pleistocene gssp (head and gibbard, 2015). to conclude, our analysis emphasizes the relevance of the mj section in the frame of the mediterranean and global stratigraphy, on the base of the close similarities in the palaeoclimate and palaeovegetation patterns at the early-middle pleistocene boundary. we can therefore make the following remarks: 1 climate-based correlations are potentially the starting points to produce refined age-models, provided that reliable time-markers are selected and then correlated with radiometrically dated proxy records from different regions (e.g. zanchetta et al., 2016). 2 however, pollen datum is itself a source of timecontrol points (e.g. magri and tzedakis, 2000). peculiar vegetation states could be, in fact, synchronized to precise orbital configurations, based on the relative abundances of taxa sensitive to the seasonal intensity. the mj pollen record documents several phases of expansions/contractions of floristic communities adapted to different temperature and/or seasonality contexts. this climate pattern is in agreement with that proposed by nomade et al. (submitted and reference therein) on the base of the new high resolution calcareous plankton and benthic isotope records. actually, more valuable information may be deduced by examining the odp core 976 pollen dataset (toti et al., in preparation) where there is a higher abundance of those taxa sensitive to seasonality variations, like mediterranean elements and ericaceae (fletcher and sánchez goñi, 2008). 3 the study of the terrestrial vegetation history along a w-e transect in the mediterranean permits definition 201 fig. 2 selected pollen indices against age (ka) obtained from the study of mis 19 at montalbano jonico (left) and odp site 976 (left); pollen temperature index (pti) is calculated as the ratio between mesothermic and steppic taxa. on the right edge, the ird and n. pachyderma left-coiling records from odp site 980 (wright & flower, 2002). early-middle pleistocene mediterranean pollen stratigraphy of a common climate pattern which is, for most, an expression of a global scale variability. the coherent response of the mediterranean ecosystems to climate changes appreciably improves the significance of the mediterranean sites as reference for the quaternary stratigraphy. 4 against this background, the analysis of the mj data rules out problems of vertical sediment continuity. in the context of southern italy, the climate scenario inferred from the mj section (toti, 2018) forms a coherent framework with that obtained from the sulmona section (giaccio et al., 2015). the mj and sulmona sites could, therefore, be regarded as the best reference sections of mis 19 in southern italy. acknowledgements this study was financially supported by a phd fellowship to f. toti, university of florence. we also thank n. combourieu-nebout and the members of muséum national d’histoire naturelle for the assistance in samples preparations, analysis and data processing. we are also grateful to m. marino, p. maiorano and a. girone for the constructive discussion on the interpretation of palaeoecological data from mj and odp site 976. references alonso-garcia m., sierro f.j., kucera m., flores j.a., cacho i., andersen n. (2011) ocean circulation, ice sheet growth and interhemispheric coupling of millennial climate variability during the mid‐ pleistocene (ca 800-400 ka). quaternary science reviews, 30(23-24), 3234-3247. bertini a., ciaranfi n., marino m., palombo m.r. (2010) proposal for pliocene and pleistocene land-sea correlation in the italian area. quaternary international, 219, 95-108. bertini a., toti f., marino m., ciaranfi n. (2015) vegetation and climate across the early-middle pleistocene transition at montalbano jonico, southern italy. quaternary international, 383, 74-88. ciaranfi n., lirer f., lirer l., lourens l.j., maiorano p., marino m., petrosino p., sprovieri m., stefanelli s., brilli m., girone a., joannin s., pelosi n., vallefuoco m. (2010) integrated stratigraphy and astronomical tuning of the lower-middle pleistocene montalbano jonico land section (southern italy). quaternary international, 210, 109-120. channell j.e.t., hodell d.a., singer b.s., xuan c. (2010) reconciling astrochronological and 40ar/39ar ages for the matuyama-brunhes boundary in the late matuyama chron. geochemistry, geophysics, geosystems, 11, q0aa12. combourieu-nebout n. (1995) résponse de la végétation de l'italie méridionale au seuil climatique de la fin du pliocène d'apres l'analyse pollinique haute résolution de la section de semaforo (2,46 à 2.1 ma). comptes rendus de l'académie des science paris, série iia, 321, 659-665. combourieu-nebout n., bertini a., russo-ermolli e., peyron o., klotz s., montade v., fauquette s., allen j., fusco f., goring s., huntley b., joannin s., lebreton v., magri d., martinetto e., orain r., sadori l. (2015) climate changes in central mediterranean and italian vegetation dynamics since the pliocene. review of paleobotany and palynology, 218, 127-147. ferretti p., crowhurst s.j, naafs b.d.a, barbante c. (2015) the marine isotope stage 19 in the mid latitude north atlantic ocean: astronomical signature and intra-interglacial variability. quaternary science reviews, 108, 95-110. fletcher w.j., sánchez-goñi m.f. (2008) orbitaland sub-orbital-scale climate impacts on vegetation of the western mediterranean basin over the last 48,000 yr. quaternary research, 70, 451-464. giaccio b., regattieri e., zanchetta g., nomade s., renne p.r., sprain c.j, drysdale r.n., tzedakis p.c., messina p., scardia g., sposato a., bassinot f. (2015) duration and dynamics of the best orbital analogue to the present interglacial. geology, 43(7), 603-606. head m.j., gibbard p.l. (2015) early-middle pleistocene transitions: linking terrestrial and marine realms. quaternary international, 389, 7-46. joannin s., ciaranfi n., stefanelli s. (2008) vegetation changes during the late early pleistocene at montalbano jonico (province of matera, southern italy) based on pollen analysis. palaeogeography, palaeoclimatology, palaeoecology, 270, 92-101. joannin s., bassinot f., combourieu-nebout n., peyron o., beaudouin c. (2011) vegetation response to obliquity and precession forcing during the mid pleistocene transition in western mediterranean region (odp site 976). quaternary science reviews, 30, 280-297. kleiven h., hall i.r., mccave i.n., knorr g., jansen e. (2011) north atlantic coupled deep-water flow and climate variability in the middle pleistocene. geology, 39(4), 343-346. magri d., tzedakis p.c. (2000) orbital signatures and long-term vegetation patterns in the mediterranean. quaternary international, 73/74, 69-78. maiorano p., bertini a., capolongo d., eramo g., gallicchio s., girone a., pinto d., toti f., ventruti g., marino m. (2016) climate signatures through the marine isotope stage 19 in the montalbano jonico section (southern italy): a land-sea perspective. palaeogeography palaeoclimatology palaeoecology, 461, 341-361. marino m., bertini a., ciaranfi n., aiello g., barra d., gallicchio s., girone a., la perna r., lirer f., maiorano p., petrosino p., toti f. (2015) paleoenvironmental and climatostratigraphic insights for marine isotope stage 19 (pleistocene) at the montalbano jonico section, south italy. quaternary international, 383, 104-115. marino m., aiello g., barra d., bertini a., gallicchio s., girone a., la perna r., lirer f., maiorano p., petrosino p., quivelli o., toti f., ciaranfi n. (2016) the montalbano jonico section (south italy) as a reference for the early/middle pleistocene boundary. alpine and mediterranean quaternary, 29(1), 45-57. nomade s., bassinot f., marino m., simon q., dewilde f., maiorano p., isguder g., blamart d., girone a., 202 toti f., bertini a. scao v., pereira a., toti f., bertini a., combourieu-nebout n., peral m., bourlès d.l., petrosino p., gallicchio s., ciaranfi n. (submitted) high-resolution foraminifer stable isotope record of mis 19 at montalbano jonico, southern italy: a window into mediterranean climatic variability during a low-eccentricity interglacial. quaternary science reviews. sánchez goñi m.f., rodrigues t., hodell d.a., polanco -martínez j.m., alonso-garcía m., hernándezalmeida i., desprat s., ferretti p. (2016) tropically-driven climate shifts in southwestern europe during mis 19, a low eccentricity interglacial. earth and planetary science letters, 448, 81-93. simon q., bourlès d.l., bassinot f., nomade s., marino m., ciranfi n., girone a., maiorano p., choy s., dewilde f., scao v., aster team (2017) authigenic 10be/9be ratio signature of the matuyama-brunhes boundary in the montalbano jonico marine succession. earth and planetary science letters, 460, 255-267. suc j.p., combourieu-nebout n., seret g., popescu s.a., klotz s., gautier f., clauzon g., westgate j., insinga d., sandhu a.s. (2010) the crotone series: a synthesis and new data. quaternary international, 219, 121-133. toti f. (2018) a mediterranean perspective on the early-middle pleistocene transition with emphasis on marine isotope stage 19. unpublished phd thesis, università degli studi di firenze, pp. 388. toti f., bertini a., girone a., maiorano p., marino m., bassinot f., nomade s., combourieu-nebout n., buccianti a. (article in preparation) impact of glacial-interglacial climate variability on marine and terrestrial ecosystems between mis 20 and mis 19: a western mediterranean viewpoint. quaternary science reviews. tzedakis p.c., andrieu v., de beaulieu j.l., crowhurst s., follieri m., hooghiemstra h., magri d., reille m., sadori l., shackleton n.j., wijmstra t.a. (1997) comparison of terrestrial and marine records of changing climate of the last 500,000 years. earth and planetary science letters, 150, 171-176. tzedakis p.c., channell j.e.t., hodell d.a., kleiven h.f., skinner l.c. (2012) determining the natural length of the current interglacial. nature geoscience, 5, 1-4. wright a.k., flower b.p. (2002) surface and deep ocean circulation in subpolar north atlantic during the mid-pleistocene revolution. paleoceanography, 17, 1068. zanchetta g., regattieri e., giaccio b., wagner b., sulpizio r., francke a., vogel h., sadori l., masi a., sinopoli g., lacey j.h., leng m.j., leicher n. (2016) aligning and synchronization of mis5 proxy records from lake ohrid (fyrom) with independently dated mediterranean archives: implications for deep core chronology, biogeosciences, 13, 2757-2768. yin q.z., berger a. (2015) individual contribution of insolation and co2 to the interglacial climates of the past 800,000 years. climate dynamics, 38, 709-724. 203 early-middle pleistocene mediterranean pollen stratigraphy ms. received: may 11, 2018 final text received: may 14, 2018 204 amq34(2) 237-256 bosio et al def immrid.pdf available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 34 (2), 2021, 237-256 1. introduction throughout the cenozoic era, the mediterranean region has been characterized by the presence of coral reefs (esteban, 1996, bosellini & perrin, 2008; perrin & bosellini, 2012; vertino et al., 2014). in particular, the mediterranean can presently boast its own and unique kind of coral bioconstructions: the cladocora caespitosa (linnaeus, 1767) banks. cladocora caespitosa, also known as “cushion coral”, is the largest and most common species of symbiont-bearing, colonial scleractinian coral of the mediterranean (e.g., peirano et al., 2004). although scattered colonies of c. caespitosa are relatively common, large banks (i.e., more than a meter high and several meters wide) consisting of a large number of coalescent colonies are relatively rare, with only about ten of these structures being currently known basinwide (peirano et al., 2001; kersting & linares, 2012; el kateb et al., 2016; chefaoui et al., 2017). these banks do not grow up to the water surface like their tropical counterparts and usually develop in relatively protected settings (with the two largest banks occurring in a marine lake and in an extinct volcanic caldera, respectively), where they are sheltered by violent storm waves (kružić & benković, 2008; kersting & linares, 2012; hadjioannou et al., 2016; chefaoui et al., 2017). similar to their living counterparts, large fossil c. caespitosa banks are also rare (el kateb et al., 2016; coletti et al., 2018b). in the present-day scenario of climate warming, c. caespitosa is severely threatened by heat waves, pollution and human coastal activities (rodolfo-metalpa et al., 2006; kružić & benković, 2008; peirano et al., 2009; kružić et al., 2012; el kateb et al., 2016). as a consequence of that, c. caespitosa is listed as a protected species and its banks are regarded as protected habitats (european community, 1992; casado -amezúa et al., 2015). because of the rarity of c. caespitosa banks, the environmental conditions favorable to their development as well as the associated fauna are relatively poorly known and loosely constrained, with only few studies existing for both recent and fossil occurrences (e.g., conato & dai pra, 1980; fornós et al., 1996; bernasconi et al., 1997; aguirre & jiménez , 1998; koukouras et al., 1998; drinia et al., 2010; amorosi et al., 2014; pitacco et al., 2014; chefaoui et al., 2017; monnier et al., 2021). the investigation of fossil examples poses further difficulties since diagenetic processes have the potential to skew fossil assemblages via the https://doi.org/10.26382/amq.2021.15 exceptionally preserved coral bank and seagrass meadow from the lower pleistocene of fauglia (tuscany, italy). giulia bosio 1, andrea di cencio 2-3, giovanni coletti 1, simone casati 2, alberto collareta 4 1 dipartimento di scienze dell’ambiente e della terra, università degli studi di milano-bicocca, milano, italy 2 gruppo avis mineralogia e paleontologia scandicci, scandicci (fi), italy 3 studio tecnico geologia e paleontologia, san casciano val di pesa (fi), italy 4 dipartimento di scienze della terra, università di pisa, pisa, italy corresponding author: g. bosio <giulia.bosio.giulia@gmail.com> abstract: near the fauglia village (tuscany, italy), a calabrian (lower pleistocene) stratigraphic succession crops out in a sand quarry. this succession is comprised of an alternation of sands and silts featuring an exceptionally preserved posidonia oceanica meadow (preserving in situ rhyzomes and loose leaves) and an abundant and diverse assemblage of fossil invertebrates that also includes the zooxanthellate coral cladocora caespitosa. the latter forms a rare example of a cladocora bank, exhibiting peculiar fossilization modes that range from compound molds to recrystallized corallites, overlain by an oyster reef. paleoenvironmental considerations, based on a comparison with analogue environments from the present-day mediterranean region, indicate a shallow-water, protected marine environment characterized through time by a seagrass meadow (ranging in water depth from 10 to 35 m), a subsequent coral bank (5 to 20 m water depth), and finally by an oyster reef in water shallower than 5-10 m. throughout the 6-m-thick stratigraphic section, five taphofacies are recognized, showing different diagenetic signatures. subsequent stages of aragonite dissolution and calcite re-precipitation are thus hypothesized, revealing a complex and unusual diagenetic history for this remarkable find of exceptionally preserved pleistocene coral bank and seagrass meadow. keywords: cladocora caespitosa, posidonia oceanica, calabrian, fossil diagenesis, taphofacies. 238 bosio g. et al. 239 pleistocene coral bank and seagrass meadow from tuscany preferential dissolution of the aragonitic remains (e.g., cherns & wright, 2000; cherns et al., 2011), and this is quite unfortunate as both c. caespitosa and many of the reef-associated shell-bearing invertebrates feature skeletal parts that consist of aragonite (koukouras et al., 1998; pitacco et al., 2014). similar to c. caespitosa, posidonia oceanica (linnaeus) delile, 1813 is a shallow-water mediterranean endemic species. the meadows formed by this seagrass species comprise one of the most biologically diverse and ecologically relevant ecosystems of the mediterranean sea (duarte & chiscano, 1999; guidetti, 2000; short et al., 2007). further recalling c. caespitosa, p. oceanica is an ecosystem engineer: the meadow stabilizes the seafloor through its roots and rhizomes network, while the leaves baffle floating particles, thus favoring local sedimentation (boudouresque & jeudy de grissac, 1983; moriarty & boon, 1989; de falco et al., 2000; gacia & duarte, 2001). among its roots and canopy, p. oceanica hosts large communities of epiphytes that remarkably contribute to the local production of bioclastic sediment (mazzella et al., 1989; langer, 1993; de falco et al., 2008; mateu-vicens et al., 2014). in addition, by sustaining and providing shelter to a broad variety of large-sized animals, the seagrass meadow comprises a key element of the mediterranean biodiversity (francour, 1997; guidetti, 2000). similar to the cladocora banks, the posidonia meadows are also endangered by human activities and climate change (european community, 1992; francour et al., 1999; burkholder et al., 2007; balata et al., 2010; hendriks et al., 2017; sanchez-vidal et al., 2021). however, while living seagrass meadows can cover tens of thousands of square kilometers, very few indisputable fossil examples of such ecosystems are known as the seagrass organic materials are rarely featured in the fossil record due to their poor preservation potential (brasier, 1975; brunetti & vecchi, 2005; moissette et al., 2007; reich et al., 2015; koskeridou et al., 2019). here, we report on a pleistocene outcrop in tuscany (central italy) that features the exceptional occurrence of both a fossil seagrass meadow and a c. caespitosa bank. moving from sedimentological, taxonomic and taphonomic observations, our preliminary characterization of this outcrop reveals spectacularly preserved examples of both these important mediterranean biocoenoses. this paper aims at documenting the sedimentological features and paleontological content of the outcrop in order to reconstruct the paleoenvironmental and depositional conditions. taphonomic features of the outcrop are also examined and different taphofacies recognized to gain insights into the different styles of preservation and into the fossilization paths behind the preservation of the cladocora bank and the posidonia meadow. the paleoenvironmental reconstruction and taphonomic observations carried out in this study have the common goal of promoting this remarkable paleontological site. 2. geological setting the fossiliferous deposits studied herein are exposed at an active sand quarry located near the fauglia village (pisa province, tuscany, italy), along the left bank of the isola stream (geographic coordinates: 43° 33'52" n, 10°31'56" e). the succession exposed at the fauglia quarry (also known as montalto quarry) takes its place in the northern sector of the tora-fine basin, a post-collisional basin of the northern apennine chain (mazzanti, 2016). comprising one of the most external basins of mainland tuscany, the tora-fine basin was filled by upper miocene to pliocene sediments under extensional control (bossio et al., 1999). during the subsequent early pleistocene, a changing tectonic regime caused a substantial restructuring of the basin borders as well as significant latitudinal differences in deposition, with the surroundings of fauglia acting as the location of conspicuous marine sedimentation (bossio et al., 1999) (fig. 1a). in the study area, the pleistocene units overlie pliocene marine deposits (marroni et al., 1990) and include, in ascending stratigraphic order, the morrona formation, the sabbie di nugola vecchia fm and the casa poggio ai lecci fm (mazzanti, 2016) (fig. 1b), all of which have sometimes been mapped as comprising a single lithostratigraphic unit, namely, the sabbie e argille ad arctica islandica fm (e.g., bossio et al., 1999). the morrona fm (hereinafter, art) includes infralittoral and upper circalittoral sands and clays that have been referred to the lower calabrian (i.e., “santernian” according to the ‘italian marine stages’ regional scheme; gibbard & cohen, 2008), although the top of the formation might belong to the mid-calabrian (i.e., “emilian”) (boschian et al., 2006; catanzariti & da prato, 2020). these deposits are rich in fossil remains of macro-invertebrates, including bivalves, gastropods, brachiopods, echinids, corals, crustaceans and annelids. furthermore, “northern guests” such as arctica islandica (linnaeus, 1767) (whose first occurrence in the mediterranean basin occurs around the base of the calabrian; gibbard & head, 2010; crippa et al., 2019) are typically present (mazzanti, 2016). in the study area, the maximum thickness of the art is estimated at about 50 m (mazzanti, 2016). the sabbie di nugola vecchia fm (hereinafter, < fig. 1 a) simplified geological map of tuscany, showing the areas of mio-pleistocene outcrop, and the location of the study area (modified from carnevale et al., 2008). white: alluvial deposits; yellow: neogene and quaternary marine deposits; green: quaternary continental deposits; brown: substratum; star: study site. b) schematic geological map of the study area, showing the location of the investigated quarry (after regione toscana, 2006-2009). orange; villamagna fm (= vlms; pliocene); green: morrona formation (= art; lower pleistocene); blue: sabbie di nugola vecchia fm (= nug; lower pleistocene); gray: casa poggio ai lecci fm (= qpl; middle pleistocene); white: alluvial and fluvioglacial deposits (= b; recent), and alluvial terraces (= bn; recent); star: study site. c) chronostratigraphic assignment of the lower pleistocene sedimentary units exposed in the vicinities of fauglia (right corner) in the framework of the 2020-updated version of the "global chronostratigraphical correlation table for the last 2.7 million years" (modified from https://stratigraphy.org/icschart/ quaternarychart.pdf) (cohen & gibbard, 2019). see the main text for further details and data sources. nug) consists of fine-grained, ochre-colored sands punctuated by conglomerates and calcarenite lenses. referred by mazzanti (2016) to the mid-calabrian (i.e., emilian), these infralittoral and upper circalittoral deposits are typically poor in macroscopic fossils, although rare bivalves (ostreids and pectinids) are locally present. the nug reaches a maximum thickness of more than 100 m (mazzanti, 2016). the casa poggio ai lecci fm (hereinafter, qpl) consists of conglomerates with subordinate sands and silts that deposited in a transitional environment (including deltaic, limnic and lagoonal settings; barsotti et al., 1974) during the chibanian (middle pleistocene). macro-invertebrates from these strata are very scarce and include rare bivalves and gastropods. the thickness of the qpl ranges between 1 and ca. 30 m (mazzanti, 2016). according to bossio et al. (1993) and tani & gazzerro (1999), the art and nug would respectively represent the transgressive and regressive portions of a single depositional cycle. however, sarti et al. (2007, 2008) argued that these formations represent two distinct depositional cycles. in turn, there is consensus that the overlying qpl represents a subsequent transgression (e.g., bossio et al., 1993; sarti et al., 2008; mazzanti, 2016). the national (mazzanti, 2016), regional (regione toscana, 2006-2009), and local (marroni et al., 1990) geological cartographies agree in indicating that the fossiliferous deposits cropping out at the fauglia quarry belong to the nug (fig. 1b), and such an assignment is embraced herein. however, the abundance of fossils at the study site is not typical for nug and might suggest a different attribution of the strata cropping out therein. in other nearby tuscan basins, c. caespitosa bioconstructions have been observed in deposits that are stratigraphically congruent with the art (sarti et al., 2007), but not in nug-equivalent strata. that said, the cooccurrence of exceptionally preserved coral bank and seagrass meadow at the fauglia quarry is, to the best of our knowledge, unique among the pleistocene outcrops of western tuscany; furthermore, correlations with previously established sections are further hindered by the lateral facies variability that characterizes the aforementioned deposits (see e.g. discussion on the stratigraphic position of the argille e limi di vigna nuova di peccioli in mazzanti, 2016). up to date, published works on the paleontological aspects of the fauglia quarry have assigned the stratigraphic succession cropping out at the fauglia quarry to unnamed lower pleistocene deposits (brunetti et al., 2008; chirli & forli, 2017; cresti & forli, 2020) or to the nug (berta et al., 2015). 3. methods the outcrop studied in the present paper is 6 m high and can be followed along a 66-m-long subvertical surface at the fauglia quarry (figs. 1, 2). a stratigraphic log was measured by using a jacob’s staff and later refined with the support of laser grain-size analyses (see below). in the field, strata were described through observations on their lateral continuity, thickness, color, grainsize, vertical grading, boundaries, sedimentary structures and fossil content. ten sediment samples were collected at different stratigraphic heights (see fig. 3), with a particular attention to the lateral variability of the stratigraphic layers (e.g., the thickness of the c. caespitosa bank varies horizontally from a minimum of 10 cm to a maximum of 200 cm, see fig. 2a). sediment samples were analyzed with a malvern mastersizer 2000e™ laser granulometer at the università degli studi di milano-bicocca for gathering grainsize data. from each sample, three subsamples were obtained, and each subsample was measured three times. grain-size data were processed with the grain bosio g. et al. fig. 2 outcrop views of the lower pleistocene deposits cropping out at the fauglia quarry. a) eastward panoramic view of the analyzed outcrop exposed at the fauglia quarry. b) northward panoramic view of the analyzed outcrop exposed at the fauglia quarry. the red arrow indicates a bluish-grayish sediment lens. note people for scale. 240 3). the lateral variability of the exposed deposits is high, which makes the sedimentological characterization of the outcrop difficult. a detailed stratigraphic log was built on the basis of the laser grain-size analyses, which indicate poorly to very poorly sorted sandy mud and muddy sand, usually displaying a polymodal distribution (table 1). in particular, the percentage of sand varies between 14.8% and 64.8%, with sand being dominant at the bottom and top of the section. the percentage of mud ranges from 35.2% to 85.2%, that is, mud is generally more abundant than the sand-grained sediment. the abundance of mud peaks between 200 and 330 cm above the base of the measured section (hereinafter, abs) (fig. 3, table 1). the sand component decreases through the section up to ca. 330 cm abs, then increases upwards until the top of the stratigraphic log. up to 85 cm abs, the stratigraphic succession consists of yellowish brown sands comprised of coarse-silty medium sand. these sands host decimeter-sized shell lenses with disarticulated bivalves, and a laterally continuous shell bed characterized by articulated infaunal bivalves (fig. 3). following 10 centimeters of a muddier and more cemented deposit, another 44-cm-thick laterally continuous sandy interval is recognized. this is size analysis program gradistat (blott & pye, 2001). this software provides a physical description of the textural group which the sample belongs to, with the term “mud” referring to silt and clay indifferently, and the sediment name after folk (1954) (see table 1). in the field, invertebrate and plant fossil specimens were described according to their stratigraphic position, distribution, orientation, articulation degree, and style of preservation; some macrofossils were also carefully sampled from each stratigraphic horizon. ca. 300 fossil specimens were collected from the field with hammers, chisels and awls. they were subsequently cleaned from the sediment by using a scalpel and a small brush, after which they were stored in the laboratories and collections of the g.a.m.p.s. (gruppo a.v.i.s. mineralogia paleontologia scandicci) permanent exhibition. for paleoecological and paleoenvironmental purposes, we compared our data with known occurrences of invertebrates and plants in modern marine environments (e.g., duarte, 1991; campbell et al., 1998; luckenbach et al., 1999; kružić & benković, 2008; infantes et al., 2009; kersting & linares, 2012; chefaoui et al., 2017; kersting et al., 2017; christianen et al., 2018). for taphonomic investigations, fossil invertebrates and plants were examined under standard optical stereomicroscopes at the università degli studi di milano-bicocca and università di pisa. two thin sections were also prepared from two articulated bivalve specimens featuring internal geopetal structures. bivalves were first embedded in epoxy resin and then cut orthogonal to the hinge and parallel to the shell height. the thin sections were thus observed under a leica leitz laborlux s transmitted light optical microscope at the università degli studi di milano-bicocca for petrographic and microtextural analyses. finally, ca. 100 fossil specimens were also exposed under the long wavelength (300-400 nm) ultraviolet (uv) light of a wood lamp in the g.a.m.p.s. darkroom for studying the phosphorescence phenomena of the calcite shells as well as for enhancing the exhibition impact of the fossil collection. 4. results 4.1. sedimentological description the stratigraphic section measured at fauglia features an alternation of silty sands and sandy silts, devoid of sedimentary structures, and rich of macrofossils (fig. pleistocene coral bank and seagrass meadow from tuscany fig. 3 stratigraphic log measured at the fauglia quarry, with indication of the lithology and fossil content, and associated sand/mud grain-size diagram based on laser granulometer analyses. the stratigraphic position of the collected samples is also indicated. 241 characterized by very-coarse-silty very-fine sand with abundant disarticulated bivalves and common mud chips (fig. 3). up to 287 cm abs, the dominant sediment is a grayish brown very-fine-sandy very-coarse silt; the sand percentage decreases upwards. this interval hosts abundant plant remains that are found ca. 200 cm abs. moving laterally, this sediment is characterized by dark, bluish-grayish, laterally discontinuous lenses. these lenses span from few to few tens of meters of lateral extension (fig. 2b) and are characterized by the presence of common shell material and rare vertical invertebrate burrows (fig. 3). above this deposit, a laterally continuous, 190-cm-thick layer occurs. it consists of yellowish-brownish, coarse silts that become more sandy upwards. these silts host several bivalve specimens, featuring internal geopetal structures, as well as a conspicuous coral bank, up to ca. 200 cm in thickness (fig. 3). the stratigraphic log is topped by a 120-cmthick layer with a sharp base consisting of very-coarsesilty very-fine yellowish sand. this interval is characterized by the presence of clusters of bivalve shells that comprise a true oyster reef (sensu puffer & emerson, 1953). 4.2. faunal assemblage as also observed with respect to the sedimentological traits, the lateral variability of the paleontological content of the studied outcrop is high; nonetheless, different fossil assemblages can be recognized throughout the stratigraphic section. up to 2 m abs, below the seagrass meadow layer, the macrofossil assemblage is dominated by mollusks (mostly bivalves) (fig. 3). at the bottom, the sandy deposit is characterized by decimeter -sized lenses of common disarticulated pectinid valves together with common gastropod, venerid and cardiid specimens preserved as internal molds. the latter belong to the genera chama, pelecyora, and procardium (fig. 4). the overlying sediment hosts a horizon with abundant panopea specimens preserved as both internal and external molds in life position (fig. 4). above this shell bed, the sandy sediment is characterized by abundant bivalve shells, mainly pectinids, and by common isolated, fasciculate, centimeterto decimeter-sized patches of c. caespitosa corallites. ca. 2 m abs, a continuous layer characterized by exquisitely preserved, abundant brownish remains of p. oceanica is present (fig. 5a, b). few large specimens of pinna nobilis linnaeus, 1758 (fig. 5c) and abundant benthic foraminifera were found associated with the posidonia meadow. moving laterally, the sediment changes to dark gray, organic-rich lenses (fig. 3), where few representatives of the genera solen, pinna, and small infaunal bivalves occur. in the overlying silts, abundant mollusk specimens are preserved as completely recrystallized shells or contain geopetal structures. these include rare remains of lutraria oblonga (gmelin, 1791), abundant specimens of pelecyora sp., common mitiloids (among which the genus modiolus has been recognized), and rare gastropods of the families turritelidae and naticidae. a few centimeters above, isolated colonies of c. caespitosa start to crop out (fig. 3), and they are overlain by the cladocora bank, which displays a thickness variable between ca. 10 and 200 cm (fig. 5d-f). the coral bank is associated with abundant pectinids, including specimens of pecten, flexopecten, mimachlamys, anomia (fig. 6a-c) and common ostreids (e.g., ostrea edulis linnaeus, 1758, fig. 6d) that are mostly preserved in life position. regular echinoids also occur in the coral bank. above the bank, a discontinuous oyster reef (sensu puffer and emerson, 1953) is present, being dominated by abundant specimens of o. edulis that are pervasively encrusted by balanid barnacles and vermetid gastropods (figs. 3, 6e, f). during laboratory analyses, benthic and planktonic foraminifera, ostra bosio g. et al. tab. 1 grain-size characterization of the collected sediment samples. 242 cods, and erect bryozoans were also detected within samples from the whole succession. further micropaleontological analyses are definitively needed for providing a comprehensive description of the microscopical fossil assemblage. it is worth noting that “northern guests” such as e.g. arctica islandica were not detected among the fauglia fossil invertebrates, in contrast with previous reports by chirli & forli (2017). although this observation may prove of some litho and chronostratigraphical significance (see e.g. the distribution of the finds of northern guests across the lower pleistocene formations mentioned by mazzanti, 2016), it could also reflect taphonomic or sampling biases as well as the local establishment of unfavourable paleoenvironmental conditions (see e.g. crippa et al., 2019 for an overview of the varying habitat preferences of a. islandica across the italian pleistocene localities). thus, for the moment being, we refrain from discussing the apparent absence of northern guests at the fauglia quarry. a few elasmobranchs teeth are also known from the fauglia quarry. including a carcharhine (carcharhinus plumbeus (nardo, 1827)) and an eagle ray (myliobatidae indet.), these specimens come from displaced quarry debris; therefore, their stratigraphic whereabouts are unfortunately unknown. another vertebrate fossil, consisting of an isolated pinniped calcaneum assigned to an indeterminate genus and species of monachini (monk seals and relatives), was also described from the fauglia quarry by berta et al. (2015). 4.3. taphonomy in ascending stratigraphic order, five different taphofacies (i.e., facies defined on the basis of diagnostic taphonomic traits; speyer & brett, 1986) have been recognized. individuation of the taphofacies followed the criteria proposed by gonҫalves garcia et al. (2021), based on biostratinomic observations (regarding e.g. the degrees of articulation, orientation and fragmentation), the presence or absence of encrusting episkeletozoans, and especially the macroand microscopic evidence for the action of diagenetic mechanisms such as dissolution, cementation, recrystallization, neomorphism and cavity filling. taphofacies 1. found at the base of the studied succession, this taphofacies consists of accumulations of disarticulated, usually fragmented, randomly disposed pectinid shells and calcite internal molds of articulated bivalve shells. fully articulated specimens of the infaunal bivalves panopea are preserved in life position as calcite internal molds and, less abundantly, as external molds (fig. 7a). the internal molds are formed by sedi pleistocene coral bank and seagrass meadow from tuscany fig. 4 examples of the faunal assemblage from below the posidonia-rich interval. a) internal mold of chama sp. b) internal mold of panopea sp. c, d) external views of an internal mold of pelecyora sp. e, f) external and umbonal views of an internal mold of procardium sp. ment cemented by calcite. aragonitic shells are not preserved, whereas the calcite ones retain their original mineralogical composition. shells do not exhibit encrusting organisms, nor traces thereof. this taphofacies also includes isolated, reworked blocks of c. caespitosa preserved as external molds. the associated sediment is constituted by mediumto very fine-grained sands. taphofacies 2. this taphofacies hosts several exceptionally preserved plant remains in form of brownish mineralized remains of p. oceanica, including both rhizomes and leaves (fig. 7b). rhizomes are usually rather complete and preserved in situ, whereas leaves are detached, generally fragmented, and randomly oriented. they do not show any encrusted organisms or traces of encrustation. this taphofacies occurs in very coarsegrained brownish silt and is heteropic with taphofacies 3. taphofacies 3. this facies is characterized by black peaty remains of p. oceanica as well as finely preserved aragonitic shells (fig. 7c). infaunal and semi 243 bosio g. et al. fig. 5 field photos of the posidonia-rich interval and cladocora caespitosa bank. a) posidonia oceanica rhyzomes in life position. b) detail of posidonia oceanica rhyzome and leaves. c) pinna nobilis specimen in life position from a posidonia-rich interval. d) cladocora caespitosa bank preserved as external molds. e, f) cladocora caespitosa clusters preserved with shells found ex situ. 244 pleistocene coral bank and seagrass meadow from tuscany fig. 6 field photos of the faunal assemblage associated to the cladocora caespitosa bank and specimens from the oyster reef. a) articulated specimen of mimachlamys sp. preserved in situ in the coral bank. b, c) disarticulated specimens of flexopecten sp. d) articulated ostreid specimen preserved in situ in the coral bank. e, f) balanid barnacles encrusting ostrea edulis specimens from the oyster reef. 245 bosio g. et al. fig. 7 different preservation styles from the five fauglia taphofacies. a) internal mold of panopea specimen preserved in life position from taphofacies 1. b) exceptionally preserved, brownish posidonia oceanica rhyzomes from taphofacies 2. c) brownish posidonia oceanica remains from taphofacies 2 and adjacent black peaty posidonia oceanica remains in dark gray sediments from the taphofacies 3. d) geopetal calcite filling of a bivalve found in life position from taphofacies 4 (note the large-sized euhedral crystals). e) geopetal structure of a bivalve showing different generations of calcite cements from taphofacies 4. f) fully recrystallized naticid gastropod from taphofacies 4. g) external molds of cladocora caespitosa corallites from taphofacies 5. h) compound molds of the cladocora caespitosa bank from taphofacies 5. 246 infaunal bivalves such as p. nobilis exhibit a well preserved nacreous aragonitic shell and are fully articulated, in life position. the p. nobilis specimens usually display an incomplete upper portion, probably due to the low preservation potential of the fragile nacreous shell exposed to seawater (e.g. bracchi et al., 2020). the surrounding sediment, a very coarse-grained silt, is dark -colored, probably as a consequence of the high amount of organic matter it hosts. taphofacies 4. in this taphofacies, mollusks are partially or completely recrystallized. they often exhibit geopetal structures that are recognizable in both bivalves and gastropods (fig. 7d, e). bivalves are preserved as fully articulated shells, usually in life position, and do not display any evidence of encrustation. cladocora caespitosa, usually preserved in form of isolated in situ patches, is also represented by completely recrystallized corallites. thin sections of the geopetal structures of infaunal bivalves (fig. 8a-d) show at least four stages of mineral precipitation: the cementation of the terrigenous infill; the recrystallization of the shell following aragonite dissolution; and two steps of precipitation of large-sized calcite crystals filling the remaining voids. petrographic analyses and reaction to 5%-diluted hcl reveal a calcite composition for all these phases. all the sampled materials coming from this taphofacies become luminescent under uv light excitation; the light emission fades in a few seconds after cessation of the uv exposition (fig. 9a-e). this taphofacies is associated with coarse-grained silt. taphofacies 5. this taphofacies is dominated by a conspicuous, 66-m-long c. caespitosa bank in which the corallites are only preserved as compound molds or as recrystallized shells (fig. 7g, h). internal molds of articulated infaunal bivalves are also found. no aragonitic skeletons are observed, whereas calcite invertebrates such as pectinids, oysters and barnacles preserve their original shells and are found in life position, with fully articulated valves and mural plates, both in the coral bank and in the oyster reef (see fig. 6). no fragmentation is observed in this facies. the disposition of encrusting organisms, such as balanid barnacles and vermetid gastropods, on the upper outer surface of the oyster shells positively indicates an in-vivo colonization of the pleistocene coral bank and seagrass meadow from tuscany fig. 8 thin section and microphotographs of the geopetal structure of a bivalve from taphofacies 4. note the laminated sediment infill. the microphotographs show a benthic foraminifer and a echinoid spine within the sediment (c), different calcite generations (a, b) and the substitution of the original shell by big calcite crystals (d). 247 latter (luci and lazo, 2014). this taphofacies is associated with coarse-grained silt and, in case of the oyster reef, with very fine-grained sand. 5. discussion 5.1. paleoenvironmental reconstruction the fauglia succession features a high diversity of marine invertebrates (including bivalves, gastropods, barnacles, echinoids, corals, foraminifera, ostracods and erect bryozoans) and well-preserved marine plants. this fossil association can be related to three important coastal biotopes, namely: the cladocora bank, the posidonia meadow, and the oyster reef (fig. 10). the latter, although presently extinct along the european coasts due to overfishing, is known to have been a common feature of coastal areas until one century ago (airoldi & beck, 2007; christianen et al., 2018). the lowermost 1.5 m of the succession are characterized by transported shell fragments and cladocora small clusters, but also feature in situ bivalves, mostly represented by sand-dwelling panopea clams. nowadays, panopea clams (geoducks), the largest burrowing bivalves of the world, are found in a broad spectrum of unconsolidated substrates (from clay to gravel), down to a depth of 1 m below the sediment surface. they range in distribution from the intertidal zone to depths greater than 110 m, but concentrate between 3 m and 20-24 m of water depth (campbell et al., 1998; bureau et al., 2002). therefore, considering the high density of panopea specimens in the lowermost part of the fauglia outcrop, a subtidal seafloor shallower than 24 m is here hypothesized. posidonia oceanica meadows are a major feature of the mediterranean biota, covering a remarkable percentage of the shallow coastal areas (vacchi et al., 2017). they usually extend from 0 to 50 m water depth, but mostly occur between 10 and 35 m, with the upper and lower limits being controlled by hydrodynamic energy and light penetration, respectively (duarte, 1991; piazzi et al., 2000; infantes et al., 2009; vacchi et al., 2017). the wellpreserved in situ rhyzomes and the specimens of p. nobilis preserved in life position (a powerful seagrass meadow indicator; vázquez-luis et al., 2014; reich et al., 2015), unambiguously indicate that the posidonia-rich layer developed at less than 50 m water depth, and most likely between 10 and 35 m. although the grain-size distribution of the sediment associated with the posidonia remains could be related to the baffling effect of the plant leaves (boudouresque & jeudy de grissac, 1983; moriarty & boon, 1989; de falco et al., 2000; gacia & duarte, 2001; reich et al., 2015), the grain-size of the sediment and the high content of organic matter (witnessed by the dark color of the deposit) might suggest a moderate to lowenergy environment where the sedimentation rate was moderately high. actually, marine sediments deposited under oxic conditions are generally characterized by a positive correlation between organic carbon content and sedimentation rate, with moderate amounts of organic carbon (i.e., 0.1-2%) being usually associated with moderately rapid sedimentation rates (i.e., 1-10 cm per 1000 yr.) (müller & suess, 1979; stein, 1990). nowadays, c. caespitosa occurs between 5 and 35 m water depth; however, the largest majority of largesized banks and beds with high densities of colonies occur between 5 and 20 m, and especially between 10 and 15 m (kružić & požar-domac, 2003; kružić & benković, 2008; kersting & linares, 2012; el kateb et al., 2016; kersting et al., 2017; mačić et al., 2019). the development of these bioconstructions seems to be related to a delicate balance between three environmental parameters, namely: i) water circulation and nutrient availability (which must be enough to feed the polyps), ii) adequate sheltering from storm waves that might destroy the delicate structure of cladocora colonies, and iii) conditions of water clarity (necessary for the symbionts of the coral to thrive) (kružić & benković, 2008; kersting & linares, 2012; chefaoui et al., 2017). these requirements are usually attained along coastlines with complex physiographies and sheltered bays characterized by fine-grained sedimentation; this pattern can be observed in both modern and fossil cladocora banks (chefaoui et al., 2017; coletti et al., 2018b). the bank of fauglia is remarkably similar to the large banks that currently occur along the eastern adriatic coast (kružić & benković, 2008), as it is characterized by a remarka bosio g. et al. fig. 9 recrystallized calcite specimens from taphofacies 4 showing phosphorescence under uv light. a, b. recrystallized bivalve specimen. c. recrystallized turritellid gastropod. d. recrystallized naticid gastropod. e. recrystallized bivalve specimen showing large euhedral crystals. 248 ble thickness and especially lateral continuity. further recalling the present-day cladocora banks (koukouras et al., 1998; pitacco et al., 2014, 2017), the fauglia bank occurs associated with a molluscan assemblage dominated by hard-substrate taxa such as pecten, flexopecten, mimachlamys, o. edulis and anomia. for summarizing, in light of the distribution of modern cladocora banks, we suggest that the fauglia bank developed between 5 and 20 m water depth (and possibly between 10 and 15 m), in a relatively sheltered setting. similar conditions were probably common along the pleistocene coastline of central italy, as witnessed by the abundance of c. caespitosa remains in both lower (bonadonna, 1967; conato & dai pra, 1980; sarti et al., 2007; bizzarri & baldanza, 2020) and middle to upper pleistocene deposits (romano et al., 1994; zanchetta et al., 2019). the oyster reef that characterizes the uppermost part of fauglia succession consists of small clusters of shells of o. edulis encrusted by abundant balanid barnacles and less vermetid gastropods. these shell clusters recall the small bioconstructions currently developed by o. edulis along the northern coasts of europe in waters shallower than 5 m (christianen et al., 2018; kregting et al., 2020). more generally, oyster reefs usually occur in very shallow settings, from the intertidal zone up to 10 m of water depth (puffer & emerson, 1953; haven & whitcomb, 1983; luckenbach et al., 1999; boudreaux et al., 2006; la peyre et al., 2014; gain et al., 2017; toscano et al., 2018). oysters can also build reef into deeper waters (e.g., angeletti & taviani, 2020); however, such bioconstructions do not display abundant barnacles like the shallow-water ones (e.g., boudreaux et al., 2006; barnes et al., 2010; lunt et al., 2017). oyster reefs are usually favored by gently sloping, complex coastlines; hydrodynamic energy must be low enough to favor larval pooling (and as such, the clustering of subsequent generations of individuals) while also providing suitable shallow-water settlement substrate (kregting et al., 2020). thus, similar to its modern counterparts, the fauglia oyster reef probably developed in very shallow water (less than 5-10 m) and, possibly, in a shallow bay. the abundant presence of barnacles might suggest elevated nutrient availability, as barnacles are particularly enhanced by plankton abundance (sanford & menge, 2001; coletti et al., 2018a; coletti et al., 2021). overall, the studied succession illustrates a progressive shallowing of the depositional environment. this shallowing-upward trend favored the development of the cladocora bank over an area that was previously colonized by the posidonia meadow. as observed by monnier et al. (2021), large concentrations of c. caespitosa colonies might coexist alongside seagrass meadows, but the former develops near the upper bathymetric limit of the meadows, suggesting that decreasing water depth might induce a shift from a posidonia-dominated environment to a c. caespitosa-dominated environment. further shallowing might have fostered the development of the oyster reef that could have taken advantage from the hard substrate provided by the c. caespitosa bank. the well-preserved, organic-rich, seagrass meadow, the c. caespitosa bank, and the oyster reef are all indicative of a relatively protected setting, not exposed to large pleistocene coral bank and seagrass meadow from tuscany fig. 10 schematic paleoenvironmental reconstruction of the early pleistocene fauglia paleoecosystem. 249 storm-waves. as already mentioned, the stratigraphic whereabouts of the vertebrate finds from fauglia are unfortunately unknown. however, eagle rays such as the widespread myliobatis are nearshore durophagous fishes (e.g., jardas et al., 2004) that might have fed upon the hard-shelled invertebrates of the coral bank and oyster reef. the sandbar shark, c. plumbeus, is also a largely coastal fish. interestingly, in the present-day mediterranean sea, conspicuous numbers of sandbar sharks have been observed in the gulf of gabes, tunisia, in occurrence of the largest posidonia meadow worldwide (enajjar et al., 2015); interestingly, until recent environmental degradation, this area was also characterized by cladocora banks (el kateb et al., 2016). finally, the only living mediterranean pinniped, the monachine monk seal monachus monachus (hermann, 1779), is thought to occasionally include p. oceanica in its diet (salman et al., 2001; pierce et al., 2011). 5.2. a complex taphonomic history what is remarkable of the fauglia fossil site is the co-occurrence of several different preservation modes (fig. 7) that have been used for defining the five aforementioned taphofacies. although taphofacies were originally developed for paleozoic fossil invertebrate associations (brett & baird, 1986; speyer & brett, 1986, 1988), this concept has also been employed for the study of invertebrateand vertebrate-bearing successions of the neogene (e.g., yesares-garcía & aguirre, 2004; hendy et al., 2006; rico-garcía et al., 2008; boessenecker et al., 2014) and of the quaternary (e.g., meldahl & flessa, 1990; kowalewski et al., 1994; parsons-hubbard, 2005). the five taphofacies recognized at fauglia take their place at different stratigraphic heights along the studied succession, but in some cases they also show significant lateral variations (e.g. taphofacies 2 and 3 are heteropic). taphofacies 2 and 3 are characterized by the presence of shells retaining their pristine aragonitic composition, such as specimens of p. nobilis (fig. 5c), as well as by spectacular fossil remains of p. oceanica (figs. 5a, b, 7b). since seagrass has a very low preservation potential, the (rarely reported) discovery of seagrass meadows in the fossil record is puzzling. seagrass remains from fossil meadow settings are very rare and only few examples have been reported worldwide (reich et al., 2015). pleistocene remains of p. oceanica are only known from rhodes, greece (moissette et al., 2007; koskeridou et al., 2019) and emilia, italy (raffi & serpagli, 1993; brunetti & vecchi, 2005, 2012). posidonia oceanica specimens are mostly represented by in situ rhyzomes buried in life position (fig. 5a). abundant leaves do also occur besides the rhyzomes, and this is quite remarkable as posidonia leaves are usually too fragile to be preserved as fossils. the reddish color exhibited by the rhyzomes preserved in taphofacies 2 (fig. 5b) is possibly provided by iron oxides (moissette et al., 2007), whereas the rhyzomes from taphofacies 3 are black and display a peaty consistence as typical of coalified compressions (sensu schopf, 1975) (fig. 7c). the dark gray color of the sediment of this taphofacies indicates abundance of organic material, suggesting oxygen deficiency within the sediment. taphofacies 1, 4 and 5 can be grouped together by virtue of the lack of aragonitic shells, which were subject to preferential dissolution (e.g., cherns & wright, 2000; cherns et al., 2011). these taphofacies are characterized by pristine calcite invertebrate remains (e.g., ostreids and pectinids; fig. 6), fossils preserved as compound molds (fig. 7a, g, h), and geopetal calcite fillings of the voids (fig. 7d, e, f). these diagenetic traits lead to hypothesize a complex taphonomic history for the studied succession, similar to that of other fossil invertebrate assemblages for which different stages of diagenetic mineral precipitation and dissolution are suggested (fernández-lópez, 1997; gioncada et al., 2018; bosio et al., 2021). in addition, all the fossil materials coming from the upper portion of the section and constituted by secondary diagenetic calcite become luminescent under uv light exposition, which suggests a high content of elements that comprise luminescent centers such as manganese (fonda, 1940; aguilar & osendi, 1982). a handful of c. caespitosa banks are known from the quaternary geological record of the mediterranean area (el kateb et al., 2016; coletti et al., 2018b), and an even lower number of fossil posidonia meadows is known (reich et al., 2015). the peculiar setting reconstructed herein for the fauglia paleo-area, consisting of a shallow bay protected from strong storm waves, might have favored the preservation of these structures, similar to what has been hypothesized for the exceptional preservation of bioconstructions such as the cirratulid and reefs that characterize the miocene strata of the east pisco basin of peru (kočí et al., 2021). low turbulence likely inhibited post-burial reworking of the invertebrate remains, thus promoting the in situ preservation of mollusks (e.g., p. nobilis, panopea sp. and pelecyora sp.), phanerogams (i.e., p. oceanica) and corals (c. caespitosa bioconstructions), for which a rapid and undisturbed burial must be hypothesized in case of highquality fossilization and lack of encrusting organisms (aguirre & jiménez, 1998). in particular, the presence of fine-grained sediments, the abundance of organic matter at the seafloor, and the lack of primary porosity could explain both the preservation of aragonitic shells and that of phanerogam remains in taphofacies 2 and 3. in fact, nacreous aragonitic shells, which have a low preservation potential, can be preserved in organic-rich sediments (hall et al., 1967; janiszewska et al., 2018), and unmineralized remains have higher preservation potentials when entombed in fine-grained sediments such as clays (e.g., butterfield, 1995; mccoy et al., 2015). on the contrary, in highly porous sediments, such as sands and/or anywhere primary textural voids occur, aragonitic remains are usually poorly preserved or absent (e.g., cherns & wright 2000; cherns et al., 2011), reflecting their relatively low resistance to changes in the chemical environment introduced by diagenesis (e.g., brand & veizer, 1980, 1981; brett & baird, 1986). in taphofacies 1, 4 and 5, high porosity (both primary and secondary) allowed for a pervasive fluid circulation that greatly impacted on fossil preservation by dissolving aragonite (which should have been very abundant in a coral bank of such dimensions). as a consequence of this, carbonate supersaturation occurred in the diagenet bosio g. et al. 250 ic environment, leading to the re-precipitation of calcite in subsequent stages (e.g., fernández-lópez, 1997 and references therein; mccoy et al., 2015). thus, different generations of cements recognizable in the compound molds and geopetal structures testify to the complex taphonomic history of these remarkable fossil-bearing facies. 6. conclusion exceptionally preserved c. caespitosa bank and p. oceanica meadow are found in the proximities of the fauglia village (tuscany, central italy). this is the only pleistocene succession in which a c. caespitosa bank occur within a vertical distance of a few meters from a p. oceanica meadow. the studied fossil assemblage allows to reconstruct biotopes that have extant analogues in the present-day mediterranean region. sedimentological and paleontological observations concur in suggesting a relatively protected setting, not exposed to large storm-waves, suitable for the development of a seagrass meadow, a c. caespitosa bank, and an oyster reef. the paleontological content of the studied succession also suggests a shallowing-upward trend. the extraordinary nature of this site is to be found in the peculiar fossilization history of this succession, characterized by a rapid burial and the lack of post-burial reworking. taphonomic features allow to recognize five distinct taphofacies, exhibiting peculiar preservation styles and diagenetic imprints. organisms with original calcite shells are usually preserved, whereas aragonitic shells are preserved only in fine-grained, non-porous, posidonia-associated sediments, where plant remains are exquisitely preserved in situ. on the other hand, the high degree of carbonate dissolution that occurred in the highly porous cladocora-bearing sediments was followed by a widespread calcite re-precipitation that allowed the preservation of invertebrates as internal, external and compound molds. the exceptional discovery of body fossils organisms characterized by a lowpreservation potential such as p. oceanica qualify the fauglia outcrop as a remarkable fossiliferous site that undoubtedly merits an adequate geoconservation effort. acknowledgements the authors wish to warmly thank lorena figliuzzi, alice pieri, marco merella, elisa malinverno and luca mariani for their support on the field; nicoletta fusi for her help with grain-size analyses; massimo orti for photos 5e and 5f; silvia sorbi and giovanni bianucci for fruitful discussions on the local geology. the authors would like to thank two anonymous reviewers and the handling editor fabrizio lirer for their useful suggestions. funding this study was supported by a grant from the università degli studi di milano-bicocca (“premio giovani talenti”) to g.b., and by grants from the ias postdoctoral research grant scheme and the systematics research fund (funded by the linnean society of london and the systematics association) to g.c. references aguilar g.m., osendi m.i. (1982) fluorescence of mn2 + in caco3. journal of luminescence, 27(4), 365375. aguirre j., jiménez a.p. (1998) fossil analogues of present-day cladocora caespitosa coral banks: sedimentary setting, dwelling community, and taphonomy (late pliocene, w mediterranean). coral reefs, 17(3), 203-213. airoldi l., beck m. (2007) status of euromediterranean coastal marine habitats: loss and trends. rapp. comm. int. mer médit., 38, 410. amorosi a., antonioli f., bertini a., marabini s., mastronuzzi g., montagna p., negri a., rossi v., scarponi d., taviani m., angeletti l., piva a., vai g.b. (2014) the middle-upper pleistocene fronte section (taranto, italy): an exceptionally preserved marine record of the last interglacial. global planetary change, 119, 23-38. angeletti l., taviani m. (2020) offshore neopycnodonte oyster reefs in the mediterranean sea. diversity, 12(3), 92. balata d., piazzi l., nesti u., bulleri f., bertocci i. (2010) effects of enhanced loads of nutrients on epiphytes on leaves and rhizomes of posidonia oceanica. journal of sea research, 63(3-4), 173179. barnes b.b., luckenbach m.w., kingsley-smith p.r. (2010) oyster reef community interactions: the effect of resident fauna on oyster (crassostrea spp.) larval recruitment. journal of experimental marine biology and ecology, 391(1-2), 169-177. barsotti g., federici p.r., granelli l., mazzanti r., salvatorini g. (1974) studio del quaternario livornese, con particolare riferimento alla stratigrafia ed alle faune delle formazioni del bacino di carenaggio della torre del fanale. memorie della societa geologica italiana, 13, 425-495. bernasconi m.p., corselli c., carobene l. (1997) a bank of scleractinian coral cladocora caespitosa in the pleistocene of the crati valley (calabria, southern italy): growth vs environmental conditions. bollettino della società paleontologica italiana, 36, 53-61. berta a., kienle s., bianucci g., sorbi s. (2015) a reevaluation of pliophoca etrusca (pinnipedia, phocidae) from the pliocene of italy: phylogenetic and biogeographic implications. journal of vertebrate paleontology, 35(1), e889144. bizzarri r., baldanza a. (2020) integrated stratigraphy of the marine early pleistocene in umbria. geosciences, 10(9), 371-395. blott s.j., pye k. (2001) gradistat: a grain size distribution and statistics package for the analysis of unconsolidated sediments. earth surface processes and landforms, 26(11), 1237-1248. boessenecker r.w., perry f.a., schmitt j.g. (2014) comparative taphonomy, taphofacies, and bonebeds of the mio-pliocene purisima formation, central california: strong physical control on marine vertebrate preservation in shallow marine settings. plos one, 9(3), e91419. pleistocene coral bank and seagrass meadow from tuscany 251 bonadonna f.p. (1967) studi sul pleistocene del lazio. iii. linee di costa lungo il litorale di tarquinia (lazio settentrionale). geologica romana, 6, 131135. boschian g., bossio a., dall’antonia b., mazzanti r. (2006) il quaternario della toscana costiera. studi costieri, 12, 1-208. bosellini f., perrin c. (2008) estimating mediterranean oligocene-miocene sea surface temperatures: an approach based on coral taxonomic richness. palaeogeography, palaeoclimatology, palaeoecology, 258, 71-88. bosio g., bracchi v.a., malinverno e., collareta a., coletti g., gioncada a., kočí t., di celma c., bianucci g., basso d. (2021) taphonomy of a panopea ménard de la groye, 1807 shell bed from the pisco formation (miocene, peru). comptes rendus palevolution, 20(8), 119-140. bossio a., costantini a., lazzarotto a., liotta d., mazzanti r. (1993) rassegna delle conoscenze sulla stratigrafa del neoautoctono toscano. memorie della società geologica italiana, 49, 17-98. bossio a., foresi l.m., liotta d., mazzanti r., mazzei r., salvatorini g., squarci p. (1999) riordino delle conoscenze sul bacino neogenico del torafine (toscana-italia). atti della società toscana di scienze naturali, memorie, serie a, 106, 1-16. boudouresque c., jeudy de grissac f.a. (1983) l’herbier à posidonia oceanica en méditerranée: les interactions entre la plante et le sédiment. journal de recherche océanographique , 8(2-3), 99-122. boudreaux m.l., stiner j.l., walters l.j. (2006) biodiversity of sessile and motile macrofauna on intertidal oyster reefs in mosquito lagoon, florida. journal of shellfish research, 25(3), 1079-1089. bracchi v., bulegato s., basso d. (2020) palaeoecology of the pinna nobilis biofacies along the stirone river (early pleistocene, northern italy). bollettino della società paleontologica italiana, 59(1), 41-55. brand u., veizer j. (1980) chemical diagenesis of a multicomponent carbonate system-1: trace elements. journal of sedimentary research, 50, 1219-1236. brand u., veizer j. (1981) chemical diagenesis of a multicomponent carbonate system-2: stable isotopes. journal of sedimentary research, 51, 987997. brasier m.d. (1975) an outline history of seagrass communities. palaeontology, 18, 681-702. brett c.e., baird g.c. (1986) comparative taphonomy; a key to paleoenvironmental interpretation based on fossil preservation. palaios, 1(3), 207-227. brunetti m.m., forli m., vecchi g. (2008) una nuova specie di gibbula per il pleistocene italiano: gibbula (forskalena) sirigui n. sp. (mollusca: gastropoda). bollettino malacologico, 44(7-11), 1-4. brunetti m.m., vecchi g. (2005) rissoa quarantelli, una nuova specie del pleistocene inferiore italiano. bollettino malacologico, (41), 60-65. brunetti m.m., vecchi g. (2012) nuove specie del genere alvania (caenogastropoda: rissoidae) nel pleistocene dell’emilia occidentale (nord italia). bollettino malacologico, 48(1), 42-50. bureau d., hajas w., surry n.w., hand c.m., dovey g., campbell a. (2002) age, size structure and growth parameters of geoducks (panopea abrupta, conrad 1849) from 34 locations, in british columbia sampled between 1993 and 2000. canadian technical report of fisheries and aquatic sciences, 2413, 1-84. burkholder j.m., tomasko d.a., touchette b.w. (2007) seagrasses and eutrophication. journal of experimental marine biology and ecology, 350(1-2), 4672. butterfield n.j. (1995) secular distribution of burgess shale type preservation. lethaia, 28(1), 1-13. campbell a., harbo r.m., hand c.m. (1998) harvesting and distribution of pacific geoduck clams, panopea abrupta, in british columbia. in: proceedings of the north pacific symposium on invertebrate stock assessment and management (ed. by jamieson g.s., campbell a.). canadian special publication of fisheries and aquatic sciences, 125, 349-358. carnevale g., longinelli a., caputo d., barbieri m., landini w. (2008) did the mediterranean marine reflooding precede the mio-pliocene boundary? paleontological and geochemical evidence from upper messinian sequences of tuscany, italy. palaeogeography, palaeoclimatology, palaeoecology, 257(1-2), 81-105. casado-amezúa p., kersting d., linares c.l., bo m., caroselli e., garrabou j., cerrano c., ozalp b., terrón-sigler a., betti f. (2015) cladocora caespitosa. the iucn red list of threatened species, e.t133142a75872554. doi: 10.2305/iucn.uk.2015-2.rlts.t133142a75872554.en catanzariti r., da prato s. (2020) new biostratigraphic and lithological data on the neogene and quaternary of the livorno area (tuscany, central italy). rivista italiana di paleontologia e stratigrafia, 126 (3), 725-749. chefaoui r. m., casado-amezúa p., templado j. (2017) environmental drivers of distribution and reef development of the mediterranean coral cladocora caespitosa. coral reefs, 36(4), 11951209. cherns l., wright v. p. (2000) missing molluscs as evidence of large-scale, early skeletal aragonite dissolution in a silurian sea. geology, 28(9), 791794. cherns l., wheeley j.r., wright v.p. (2011) taphonomic bias in shelly faunas through time: early aragonitic dissolution and its implications for the fossil record. in: taphonomy (ed. by allison p.a., bottjer d.j.). aims & scope topics in geobiology book series, vol 32. springer, dordrecht, 79-105. doi: 10.1007/978-90-481-8643-3_3 chirli c., forli m. (2017) il calabriano della toscana. gasteropodi vol. i. l’informatore piceno, ancona, pp. 90 christianen m.j.a., lengkeek w., bergsma j.h., coolen j.w.p., didderen k., dorenbosch m., driessen f.m.f., kamermans p., reuchlin-hugenholtz e., sas h., smaal a., van den wijngaard k.a., van der have t.m. (2018) return of the native facilitated bosio g. et al. 252 by the invasive? population composition, substrate preferences and epibenthic species richness of a recently discovered shellfish reef with native european flat oysters (ostrea edulis) in the north sea. marine biology research, 14(6), 590-597. cohen k.m., gibbard p.l. (2019) global chronostratigraphical correlation table for the last 2.7 million years, version 2019 qi-500. quaternary international, 500, 20-31. coletti g., bosio g., collareta a., buckeridge j., consani s., el kateb a. (2018a) palaeoenvironmental analysis of the miocene barnacle facies: case studies from europe and south america. geologica carpathica, 69(6), 573-592. coletti g., bracchi v., corselli c., marchese f., basso d., savini a., vertino a. (2018b) quaternary build -ups and rhodalgal carbonates along the adriatic and ionian coasts of the italian peninsula: a review. rivista italiana di paleontologia e stratigrafia, 124(2), 387-406. coletti g., bosio g., collareta a. (2021) lower pliocene barnacle facies of western liguria (nw italy): a peek into a warm past and a glimpse of our incoming future. rivista italiana di paleontologia e stratigrafia, 127, 103-131. conato v., dai pra g. (1980) livelli marini pleistocenici e neotettonica fra civitavecchia e tarquinia. geologica romana, 19, 181-194. cresti m., forli m., (2020) new specimens of tectura rubroradiata chirli & forli, 2017 (gastropoda: lottiidae), little known species from tuscan lower pleistocene. bollettino malacologico, 56, 107-110. crippa g., azzarone m., bottini c., crespi s., felletti f., marini m., petrizzo m.r., scarponi d., raffi s., raineri g. (2019) bio-and lithostratigraphy of lower pleistocene marine successions in western emilia (italy) and their implications for the first occurrence of arctica islandica in the mediterranean sea. quaternary research, 92(2), 549-569. de falco g., ferrari s., canceni g., baroli m. (2000) relationship between sediment distribution and posidonia oceanica seagrass. geo-marine letters, 20, 50-57. de falco g., bartoli m., cucco a., simeone s. (2008) intrabasinal conditions promoting the development of a biogenic carbonate sedimentary facies associated with the seagrass posidonia oceanica. continental shelf research, 28(6), 797-812. drinia h., antonarakou a., tzortzaki e. (2010) benthic foraminifera associated with the zooxanthellate coral cladocora in the pleistocene of the kos island (aegean sea, greece): sea level changes and palaeoenvironmental conditions. bulletin of the geological society of greece, 43(2), 613-619. duarte c.m. (1991) seagrass depth limits. aquatic botany, 40(4), 363-377. duarte c.m., chiscano c.l., (1999) seagrass biomass and production: a reassessment. aquatic botany, 65, 159-174. el kateb a., stalder c., neururer c., pisapia c., spezzaferri s. (2016) correlation between pollution and decline of scleractinian cladocora caespitosa (linnaeus, 1758) in the gulf of gabes. heliyon, 2(11), e00195. enajjar s., saidi b., bradai m.n. (2015) the gulf of gabes (central mediterranean sea): a nursery area for sharks and batoids (chondrichthyes: elasmobranchii). cahiers de biologie marine, 56(2), 143-150. esteban m. (1996) an overiew of of miocene reefs from mediterranean areas: general trends and facies models. in: models for carbonate stratigraphy, from miocene reef complex of the mediterranean area (ed. by franseen e.k., esteban m., ward w.c., rouchy j.m.). concepts in sedimentology and paleontology, 5, 3-53. european community (1992) council directive 92/43/ eec on the conservation of natural habitats and of wild fauna and flora. official journal of the european union, 206, 7-50. fernández-lópez s.r. (1997) ammonites, clinos tafonómicos y ambientes sedimentarios. revista española de paleontología, 12, 102-128. folk r.l. (1954) the distinction between grain size and mineral composition in sedimentary-rock nomenclature. journal of geology, 62, 344-359. fonda g.r. (1940) the preparation of fluorescent calcite. the journal of physical chemistry, 44(4), 435-439. fornós j.j., baron a., pons g.x. (1996) arrecifes de coral hermatípicos (cladocora caespitosa) en el relleno holoceno de la zona de es grau (menorca, mediterráneo occidental). geogaceta, 20(2), 303306. francour p. (1997) fish assemblages of posidonia oceanica beds at port cros (france, nw mediterranean): assessment of composition and long term fluctuations by visual census. marine ecology, 18 (2), 157-173. francour p., ganteaume a., poulain m. (1999) effects of boat anchoring in posidonia oceanica seagrass beds in the port cros national park (north western mediterranean sea). aquatic conservation: marine and freshwater ecosystems, 9(4), 391-400. gacia e., duarte c.m. (2001) sediment retention by a mediterranean posidonia oceanica meadow: the balance between deposition and resuspension. estuarine, coastal and shelf science, 52(4), 505514. gain i.e., brewton r.a., robillard m.m.r., johnson k.d., smee d.l., stunz g.w. (2017) macrofauna using intertidal oyster reef varies in relation to position within the estuarine habitat mosaic. marine biology, 164(1), 1-16. gibbard p., cohen k.m. (2008) global chronostratigraphical correlation table for the last 2.7 million years. episodes, 31, 243-247. gioncada a., petrini r., bosio g., gariboldi k., collareta a., malinverno e., bonaccorsi e., di celma c., pasero m., urbina m., bianucci g. (2018) insights into the diagenetic environment of fossil marine vertebrates of the pisco formation (late miocene, peru) from mineralogical and sr-isotope data. journal of south american earth sciences, 81, 141-152. gonҫalves garcia g.g., henriques m.h., garcia a.j.v., pleistocene coral bank and seagrass meadow from tuscany 253 dantas m.v.s. (2021) petrofacies and taphofacies analyses of coquinas as a tool for the establishment of a stratigraphic evolution model of the morro do chaves formation (sergipe-alagoas basin, ne brazil). facies, 67(1), 1-19. guidetti p. (2000) differences among fish assemblages associated with nearshore posidonia oceanica seagrass beds, rocky-algal reefs and unvegetated sand habitats in the adriatic sea. estuarine, coastal and shelf science, 50(4), 515-529. hadjioannou l., jimenez c., hartingerova j., hayes d. (2016) cladocora caespitosa corals impacted by extreme windstorm generated swells in cyprus. rapp. comm. int. mer médit. 41, 350. hall a., kennedy w.j., taylor j.h. (1967) aragonite in fossils. proceedings of the royal society of london. series b. biological sciences, 168(1013), 377-412. haven d.s., whitcomb j.p. (1983) the origin and extent of oyster reefs in the james river, virginia. journal of shellfish research, 3(2), 141. hendriks i.e., olsen y.s., duarte c.m. (2017) light availability and temperature, not increased co2, will structure future meadows of posidonia oceanica. aquatic botany, 139, 32-36. hendy a.j., kamp p.j., vonk a.j. (2006) cool-water shell bed taphofacies from miocene-pliocene shelf sequences in new zealand: utility of taphofacies in sequence stratigraphic analysis. geological society, london, special publications, 255(1), 283 -305. infantes e., terrados j., orfila a., canellas b., alvarezellacuria a. (2009) wave energy and the upper depth limit distribution of posidonia oceanica. botanica marina, 52, 419-427. janiszewska k., mazur m., machalski m., stolarski j. (2018) from pristine aragonite to blocky calcite: exceptional preservation and diagenesis of cephalopod nacre in porous cretaceous limestones. plos one, 13(12), e0208598. jardas i., šantić m., armin p. (2004) diet composition of the eagle ray, myliobatis aquila (chondrichthyes: myliobatidae), in the eastern adriatic. cybium, 28(4), 372-374. kersting d.k., linares c. (2012) cladocora caespitosa bioconstructions in the columbretes islands marine reserve (spain, nw mediterranean): distribution, size structure and growth. marine ecology, 33 (4), 427-436. kersting d., cebrian e., verdura j., ballesteros e. (2017) a new cladocora caespitosa population with unique ecological traits. mediterranean marine science, 18(1), 38-42. kočí t., bosio g., collareta a., sanfilippo r., ekrt b., urbina m., malinverno e. (2021) first report on the cirratulid (annelida, polychaeta) reefs from the miocene chilcatay and pisco formations (east pisco basin, peru). journal of south american earth sciences, 107, 103042. koskeridou e., thivaiou d., giamali c., agiadi k., mantzouka d. (2019) seagrass-associated molluscan and fish communities from the early pleistocene of the island of rhodes (greece). iop conference series: earth and environmental science, 221(1), 012050. koukouras a., kühlmann d., voultsiadou e., vafidis d., dounas c., chintiroglou c., koutsoubas d. (1998) the macrofaunal assemblage associated with the scleractinian coral cladocora caespitosa (l.) in the aegean sea. annales de l’institut océanographique, 74, 97-114. kowalewski m., flessa k.w., aggen, j.a. (1994) taphofacies analysis of recent shelly cheniers (beach ridges), northeastern baja california, mexico. facies, 31(1), 209-241. kregting l.t., hayden-hughes m., millar r.v., joyce p.w., smyth d.m. (2020) a first record of intertidal ostrea edulis 3d structural matrices in strangford lough northern ireland-an emergent reef? journal of sea research, 163, 101927. kružić p., sršen p., benković l. (2012) the impact of seawater temperature on coral growth parameters of the colonial coral cladocora caespitosa (anthozoa, scleractinia) in the eastern adriatic sea. facies, 58(4), 477-491. kružić p., benković l. (2008) bioconstructional features of the coral cladocora caespitosa (anthozoa, scleractinia) in the adriatic sea (croatia). marine ecology, 29(1), 125-139. kružić p., požar-domac a. (2003) banks of the coral cladocora caespitosa (anthozoa, scleractinia) in the adriatic sea. coral reefs, 22(4), 536-536. langer m.r. (1993) epiphytic foraminifera. marine micropaleontology, 20(3-4), 235-265. la peyre m., furlong j., brown l.a., piazza b.p., brown k. (2014) oyster reef restoration in the northern gulf of mexico: extent, methods and outcomes. ocean & coastal management, 89, 20-28. luckenbach m., mann r.l., wesson j.a. (1999) oyster reef habitat restoration: a synopsis and synthesis of approaches; proceedings from the symposium, williamsburg, virginia, april 1995. virginia institute of marine science, college of william and mary, williamsburg, virginia, u.s.a., pp. 373. luci l., lazo d.g. (2015) living on an island: characterization of the encrusting fauna of large pectinid bivalves from the lower cretaceous of the neuquén basin, west central argentina. lethaia, 48(2), 205-226. lunt j., reustle j., smee d.l. (2017) wave energy and flow reduce the abundance and size of benthic species on oyster reefs. marine ecology progress series, 569, 25-36. mačić v., đorđević n., petović s. (2019) first monitoring of cladocora caespitosa (anthozoa, scleractinia) in the boka kotorska bay (montenegro). studia marina, 32(1), 26-32. marroni m., mazzanti r., nencini c. (1990) geologia e geomorfologia delle colline pisane. quaderni del museo di storia naturale di livorno, 11 (supplement 1), 1-40. mateu-vicens g., khokhlova a., sebastián-pastor t. (2014) epiphytic foraminiferal indices as bioindicators in mediterranean seagrass meadows. journal of foraminiferal research, 44(3), 325-339. mazzanti r. (2016) note illustrative della carta geologi bosio g. et al. 254 ca d’italia alla scala 1:50.000, foglio 284, rosignano marittimo. servizio geologico d’italia, ispra, roma, pp. 189 mazzella l., scipione m.b., buia m.c. (1989) spatio temporal distribution of algal and animal communities in a posidonia oceanica meadow. marine ecology, 10(2), 107-129. mccoy v.e., young r.t., briggs d.e. (2015) factors controlling exceptional preservation in concretions. palaios, 30(4), 272-280. meldahl k.h., flessa k.w. (1990) taphonomic pathways and comparative biofacies and taphofacies in a recent intertidal/shallow shelf environment. lethaia, 23(1), 43-60. moissette p., koskeridou e., cornée j.j., guillocheau f., lécuyer c. (2007) spectacular preservation of seagrasses and seagrass-associated communities from the pliocene of rhodes, greece. palaios, 22(2), 200-211. monnier b., lehmann l., sartoretto s., pergent-martini c., mateo m.á., pergent, g. (2021) long-term dynamics of a cladocora caespitosa bank as recorded by a posidonia oceanica millenary archive. estuarine, coastal and shelf science, 256, 107378. moriarty d.j.w., boon p.i. (1989) interactions of seagrasses with sediment and water. in: biology of seagrass (ed. by larkum a.w.d., mccomb a.j., shepherd s.a.). elsevier, amsterdam, 500535. müller p.j., suess e. (1979) productivity, sedimentation rate, and sedimentary organic matter in the oceans i. organic carbon preservation. deepsea research, 26, 1347-1362. parsons-hubbard k. (2005) molluscan taphofacies in recent carbonate reef/lagoon systems and their application to sub-fossil samples from reef cores. palaios, 20(2), 175-191. peirano a., rodolfo-metalpa r., morri c., bianchi c.n. (2001) the mediterranean coral cladocora caespitosa (anthozoa, scleractinia). biologia marina mediterranea, 8, 259-263. peirano a., morri c., bianchi c.n., aguirre j., antonioli f., calzetta g., carobene l., mastronuzzi g., orrù p. (2004) the mediterranean coral cladocora caespitosa: a proxy for past climate fluctuations? global and planetary change, 40(1-2), 195-200. peirano a., kružić p., mastronuzzi g. (2009) growth of mediterranean reef of cladocora caespitosa (l.) in the late quaternary and climatic inferences. facies, 55, 325-333. perrin c., bosellini f.r. (2012) paleobiogeography of scleractinian reef corals: changing patterns during the oligocene-miocene climatic transition in the mediterranean. earth science reviews, 111, 1-24. piazzi l., acunto s., cinelli f. (2000) mapping of posidonia oceanica beds around elba island (western mediterranean) with integration of direct and indirect methods. oceanologica acta, 23(3), 339-346. pierce g.j., hernandez-milian g., santos m.b., dendrinos p., psaradellis m., tounta e., androukaki e., edridge a. (2011) diet of the monk seal (monachus monachus) in greek waters. aquatic mammals, 37(3), 284. pitacco v., orlando-bonaca m., mavric b., lipej l. (2014) macrofauna associated with a bank of cladocora caespitosa (anthozoa, scleractinia) in the gulf of trieste (nothern adriatic). annales, series historia naturalis, 24(1), 1-14. pitacco v., crocetta f., orlando-bonaca m., mavrič b., lipej l. (2017) the mediterranean stony coral cladocora caespitosa (linnaeus, 1767) as habitat provider for molluscs: colony size effect. journal of sea research, 129, 1-11. puffer e.l., emerson w.k. (1953) the molluscan community of the oyster-reef biotope on the central texas coast. journal of paleontology, 27, 537-544. raffi s., serpagli e. (1993) introduzione alla paleontologia. utet, torino, pp. 654. regione toscana (2006-2009). carta geologica regionale in scala 1:10.000. www502.regione.toscana.it/geoscopio/cartoteca.html reich s., di martino e., todd j.a., wesselingh f.p., renema, w. (2015) indirect paleo-seagrass indicators (ipsis): a review. earth-science reviews, 143, 161-186. rico-garcía a., aguirre j., gonzález-delgado j.á. (2008) taphonomy and taphofacies models of the pliocene deposits of vejer de la frontera (cádiz, sw spain). geobios, 41(4), 543-558. rodolfo-metalpa r., richard c., allemand d., ferrierpagès c. (2006) growth and photosynthesis of two mediterranean corals cladocora caespitosa and oculina patagonica, under normal and elevated temperatures. journal of experimental biology, 209, 4546-4556. romano p., santo a., voltaggio m. (1994) l’evoluzione geomorfologica della pianura del fiume volturno (campania) durante il tardo quaternario (pleistocene medio-superiore-olocene). il quaternario, 7(1), 41-56. salman a., bilecenoglu m., güçlüsoy h. (2001) stomach contents of two mediterranean monk seals (monachus monachus) from the aegean sea, turkey. journal of the marine biological association of the united kingdom, 81(4), 719-720. sanchez-vidal a., canals m., de haan w.p., romero j., veny, m. (2021) seagrasses provide a novel ecosystem service by trapping marine plastics. scientific reports, 11(1), 1-7. sanford e., menge b.a. (2001) spatial and temporal variation in barnacle growth in a coastal upwelling system. marine ecology progress series, 209, 143 -157. sarti g., ciampalini a., consoloni i., cerrina feroni a. (2007) i depositi del pleistocene inferiore della bassa val di cecina (toscana italia): ricostruzione stratigrafico-deposizionale e proposta di suddivisione in unità allostratigrafiche. il quaternario, 20, 151-162. sarti g., testa g., zanchetta g. (2008). a new stratigraphic insight of the upper pliocene-lower pleistocene succession of lower valdarno (tuscany, italy). geoacta, 7, 27-41. schopf j.m. (1975) modes of fossil preservation. re pleistocene coral bank and seagrass meadow from tuscany 255 bosio g. et al. view of palaeobotany and palynology, 20(1-2), 2753. short f.t., carruthers t.j.b., dennison w.c., waycott, m. (2007) global seagrass distribution and diversity: a bioregional model. journal of experimental marine biology and ecology, 350, 3-20. speyer s.e., brett c.e. (1986) trilobite taphonomy and middle devonian taphofacies. palaios, 1(3), 312-327. speyer s.e., brett c.e. (1988) taphofacies models for epeiric sea environments: middle paleozoic examples. palaeogeography, palaeoclimatology, palaeoecology, 63(1-3), 225-262. stein r. (1990) organic carbon content/sedimentation rate relationship and its palaeoenvironmental significance for marine sediments. geo-marine letters, 10, 37-44. tani f., gazzerro m. (1999) nuove osservazioni sui depositi pliopleistocenici nel bacino del torrente cascina. bollettino della società geologica italiana, 118(2), 237-241. toscano a.g., lazo d.g., luci l. (2018) taphonomy and paleoecology of lower cretaceous oyster mass occurrences from west-central argentina and evolutionary paleoecology of gregariousness in oysters. palaios, 33(6), 237-255. vacchi m., de falco g., simeone s., montefalcone m., morri c., ferrari m., bianchi c.n. (2017) biogeomorphology of the mediterranean posidonia oceanica seagrass meadows. earth surface processes and landforms, 42(1), 42-54. vázquez-luis m., march d., álvarez e., álvarezberastegui d., deudero s. (2014) spatial distribution modelling of the endangered bivalve pinna nobilis in a marine protected area. mediterranean marine science, 15(3), 626-634. vertino a., stolarski j., bosellini f.r., taviani, m. (2014) mediterranean corals through time: from miocene to present. in: the mediterranean sea: its history and present challenges (ed. by goffredo s., dubinsky z.). springer, dordrecht, 257-274. yesares-garcıa j., aguirre j. (2004) quantitative taphonomic analysis and taphofacies in lower pliocene temperate carbonate-siliciclastic mixed platform deposits (almerıa-nıjar basin, se spain). palaeogeography, palaeoclimatology, palaeoecology, 207(1-2), 83-103. zanchetta g., bini m., montagna p., regattieri e., ragaini l., da prato s., ciampalini a., dallai l., leone g. (2019) stable isotope composition of fossil ahermatypic coral cladocora caespitosa (l.) from pleistocene raised marine terraces of the livorno area (central italy). alpine and mediterranean quaternary, 32(1), 73-86. ms. received: june 29, 2021 revised: july 26, 2021 accepted: october 27, 2021 available online: november 14, 2021 256 imp.bruschi&cendrero geosite evaluation; can we measure intangible values? viola maria bruschi & antonio cendrero departamento de ciencias de la tierra y física de la materia condensada (citimac), facultad de ciencias, universidad de cantabria. avda de los castros s/n 39005, santander, cantabria (spain). e-mail: bruschiv@unican.es abstract: v.m. bruschi & a. cendrero, geosite evaluation; can we measure intangible values? (it issn 0394-3356, 2005). a discussion on issues to be addressed in the process of cataloguing and assessing geosites is presented. different stages of the process are considered: identification, classification, inventory, evaluation, protection and use. inventories to be elaborated should be satisfactory from different points of view: scientific quality of sites, definition of protection levels, possibility of educational or recreational use, or potential for generating economic activities. a problem that permeates all stages of the process is subjectivity. establishment of ranks of scientific interest for sites in a region, proposals for protection measures or drafting plans for the use of geosites cannot be based exclusively on scientific, objective criteria. subjectivity is an unavoidable (perhaps even desirable) part of all of them. this represents an important difficulty because if protection and use plans for geosites are to be successful, they should be based on transparent criteria that can be subject to external, independent scrutiny and evaluation. this should include some sort of validation to determine to what extent classifications and proposals presented reflect social values, be they expressed by specific stakeholder groups (earth scientists, decision makers, elected officials, conservationists) or general public. if those values are well reflected plans will be socially acceptable and more likely to be useful. an approach is presented based on the definition of three groups of criteria, related to: a) intrinsic quality of sites; b) potential threats and protection needs; c) potential for use. indicators are presented for each criterion. particular efforts have been made to propose indicators that can be expressed by means of continuous variables. when this has not been possible categorical, “objective” variables are used. combination of those indicators into different types of indices can be used as a means to “measure” the type of intangible qualities mentioned above. the advantage of the approach proposed is that numerical classifications of sites obtained using that kind of “quality models”, can be validated through comparison with independent external opinions or evidences. two applications to case studies for cataloguing and assessing are presented. the first one concerns the assessment of geosites using clearly-stated criteria based on observable characteristics. the methodology is applied to an existing geosites inventory; validation is carried out by comparison with a very much appreciated geomorphic landmark in the same region as well as with expenditure on two sites subject to restoration. the second case study refers to the identification and ranking of geosites for a new inventory. ranks obtained directly from surveys among geomorphologists are compared with those derived from the application of the method. the analyses presented indicate that the “quality models” used yield results that coincide quite well with independent assessments or evidences for “clearly good quality sites”. agreement is less satisfactory for sites lower down in the ranks. some inconsistencies between direct subjective assessment by individual experts and systematic assessment based on quality criteria proposed by the same expert have also been found. it is concluded that the method in its present form provides a satisfactory “coarse grain” image of sites’ quality but improvements are needed. riassunto: v.m. bruschi & a. cendrero, la valutazione dei geositi: possiamo misurare valori intangibili? (it issn 0394-3356, 2005). nel presente lavoro si tratteranno i principali aspetti relativi al procedimento della catalogazione e della valutazione dei “geositi” e, più in concreto, si tratteranno i diversi stadi del procedimento generale quali, la identificazione, la classificazione, l’inventario, la valutazione, la protezione e l’uso. gli inventari dei geositi devono esssere elaborati in modo soddisfacente dal punto di vista della qualità scientifica dei beni geologici, della definizione dei diversi livelli di protezione, dei possibili usi educativi e ricreativi e dal punto di vista del potenziale per lo sviluppo di attività economiche. uno dei principali problemi che interessano il trattamento dei “geositi” e i differenti stadi dell’analisi è la soggettività. la determinazione del grado d’interesse scientifico proprio dei beni geologici di una regione, le proposte relative alle misure di protezione o all’uso potenziale dei sopracitati beni non possono essere elaborate unicamente con criteri scientifici o obbiettivi; la soggettività deve essere considerata parte inevitabile del procedimento generale. ciò rappresenta una difficoltà importante dato che, per ottenere una protezione ed un uso soddisfacenti dei geositi, è necessario basare gli studi su criteri trasparenti e che possano essere soggetti a valutazioni e giudizi esterni ed indipendenti. ciò implica la necessità di una valutazione che permetta definire fino a che punto le classificazioni e proposte elaborate riflettono l’opinione pubblica, sia per quanto riguarda gruppi d’esperti che per quanto riguarda un pubblico più ampio. l’unica forma per rendere efficaci ed utili le proposte eleborate per il trattamento dei geositi, è che queste ultime riflettano in modo adeguato l’opinione pubblica. la metodologia che si presenta a continuazione si basa sui tre seguenti pricipali gruppi di criteri quali, la qualità intrinseca dei geositi, le potenziali minacce e necessità di protezione ed il potenziale d’uso, per ognuno dei quali si propongono degli indicatori di misura. é stato prestato un particolare sforzo nel proporre indicatori che possano essere rappresentati con variabili continue, quando non è stato possibile, si è passati a variabili categoriche cercando sempre di mantere l’oggettività dell’analisi. per misurare le qualità descritte anteriormente applicando i relativi modelli di qualità e valutazione, sono state utilizzate varie combinazioni degli indicatori attraverso l’applicazione di indici numerici. il principale vantaggio di questa metodologia risiede nella possibilità di comprovare i risultati e, di conseguenza, il metodo stesso, attraverso opinioni esterne ed indipendenti. il modello iniziale può esssere perfezionato fino ad ottenere una buona corrispondenza con le valutazioni effettuate da chi è preposto a decidere. si presentano due applicazioni relative al processo di catalogazione e di valutazione dei geositi. la prima si riferesce alla valutazione dei geositi attraverso l’uso di criteri definiti basandosi su caratteristiche oggettive e osservabili. la metodologia viene applicata a un inventario di geositi esistente, la validazione del metodo è stata ottenuta attraverso la comparazione con i risultati derivanti dalla valutazione di un geosito, il cui interesse è ampiamente riconosciuto ed accettato nella regione, e di altri due beni soggetti a ripristino e situati in due regioni limitrofe alla zona oggetto dello studio. la seconda applicazione si riferisce alla identificazione e categorizzazione dei geositi per la elaborazione di un nuovo catalogo. la categorizzazione, ottenuta attraverso un sondaggio sottoposto a geomorfologi, è stata confrontata con il “medello di qualità” constatando che i risultati ottenuti dai due metodi (modello di qualità e valutazione indipendente) coincidono abbastanza, soprattutto per quanto riguarda i beni di qualità elevata. per i geositi ritenuti di qualità inferiore, la coincidenza fra i due metodi è decisamente inferiore. inoltre è stato evidenziato un certo disaccordo fra la valutazione dei geositi soggettiva realizzata dagli esperti e la valutazione sistematica elaborata sulla base di criteri di qualità proposti dagli esperti stessi. per concludere, nonstante sia necessario apportare miglioramenti, il metodo presentato rispecchia in modo soddisfacente la valutazione dei geositi di buona qualità. keywords: geosites, cataloguing, evaluation, intangible values, quality indicators, validation, spain. parole chiave: geositi, catalogazione, valutazione, valori intangibili, indicatori di qualità, validazione, spagna. il quaternario italian journal of quaternary sciences 18(1), 2005 volume speciale, 293-306 294 v.m. bruschi & a. cendrero 1. introduction identification, cataloguing and evaluation of geosites is a complex task that stands somewhere between scientific analysis and evaluation of historical, artistic or cultural heritage. this implies the need to combine very different criteria, approaches and, in particular, disciplinary cultural backgrounds. in the process of inventorying and assessing geosites it is necessary to combine scientific criteria with other criteria related to intangible values (panizza & piacente, 1999; poli, 1999) more commonly associated with artistic or historical objects. such values include, for instance, “quality of the natural heritage”, “cultural or educational interest” (reynard et al., 2002), “tourism and recreation potential” or “protection need” (cendrero, 2000). the different tasks to be performed require, on the one hand, data collection and scientific interpretation; that is, activities normally associated with the “objective” natural or experimental sciences. on the other hand, it is necessary to make value judgements, much more common in the subjective realm of artistic object’s assessment. in a scientific environment as the earth sciences it is normally expected that opinions (scientific interpretations) are based on transparent criteria that can be subject to external, independent scrutiny and evaluation. this should include the possibility to replicate, by any operator, results obtained by another one. it is therefore convenient to design and test procedures for cataloguing and evaluation that are based on clearlystated criteria and, as far as possible, quantitative parameters. such criteria and parameters could be used to derive numerical indices obtained through well defined steps and methods (mohr, 1988). the use of that type of approach can help to “validate” the method; that is to determine to what extent assessments by a group of experts are coincident with those by other experts in the discipline. it is also desirable to “validate” what we could name “scientific consensus” against the perception by other stakeholder groups such as experts from other disciplines, decision makers, elected officials, conservationists or general public. if the method, criteria and procedure used yield results that reflect reasonably well social values and interests, the final aim of promoting careful use and conservation of geosites is more likely to be achieved. a series of stages can be identified in the general process that starts with the identification of valuable geosites and leads to their protection and use. those stages are: a) site identification; b) inventory and classification; c) evaluation; d) protection; e) use. it is important to bear in mind that the first three stages should not be the aim of this type of undertaking; they are simply means to achieve the final goal indicated above: conservation and use. it follows that inventories of geosites in general and geomorphosites in particular should be satisfactory from a variety of viewpoints. those include, obviously, quality of sites, but also usefulness for defining protection levels, carrying out educational or recreational activities, or potential to generate economic activities (martini, 2000). that is, establishment of value ranks for geosites within a region, proposals for protection measures or plans for their use should not be based exclusively on scientific criteria. if those proposal and plans are to be successful they should be accepted by local society. comparison with what has happened in many countries with respect to conservation or rehabilitation of historical and artistic heritage provides some interesting lessons. there are many examples of badly deteriorated historical buildings whose restoration and protection was achieved only when they were dedicated to purposes perceived as “useful” by society as a whole (administration or education buildings, hotels and restaurants, museums, etc). this is more difficult in the case of geosites, but it is probably worth making efforts to promote their “social usefulness”, other than the obvious preservation of a part of natural heritage. in what follows below some proposals are presented towards the establishment of systematic procedures for geosite identification, cataloguing and assessment, that try to minimise the problem of subjectivity and, at the same time, help to define protection and development actions. 2. proposed procedure accepting that subjectivity (based on expert’s opinion) is an unavoidable part of the overall inventory and assessment process, the procedure presented is based on the definition of a series of successive steps that facilitate the establishment of clearly-stated criteria. those steps are: • identification of significant criteria (“qualities” of geosites) • definition of indicators to “measure” each criterion • establishment of value ranks for individual indicators • establishment of procedure for the integration of individual qualities (formulation of a “value model”) • validation probably the most important step in the process is the identification of suitable indicators for ranking sites according to the different qualities considered. ideally all such indicators should be based on the use of continuous variables, but this will not always be possible. another important, but difficult, step is validation. contrary to models normally used in geomorphology, that try to represent physical processes, “value models” used in geosite’s assessment try to reflect opinions, be they from experts, other stakeholders groups or general public. in the case of physical models validation can easily be performed by comparing model-predicted and actual process behaviour. validation of “quality or value models” rests on a somewhat more shaky ground; probably the simplest form of validation is comparison between assessment by a study team and those of external expert teams or different social groups. the procedure proposed starts with the identification of a series of criteria that can be grouped into three main categories (cendrero, 2000): a) intrinsic quality of sites (scientific merit) • abundance/rarity • degree of scientific knowledge • usefulness as process model/example • diversity of elements of interest • age • type locality • association with historical, archaeological, artistic heritage • association with other natural heritage • state of conservation b) potential for use (social usefulness) • activities that can be carried out • observation conditions • accessibility • extent 295geosite evaluation ... • proximity to service centres • socio-economic condition of the area c) potential threats and protection needs (urgency to act) • inhabitants in the surroundings • present or potential threats • possibility to collect objects • relationship to existing planning • interest for mineral exploitation • land ownership indicators that can be used to “measure” those criteria are shown in tables 1, 2 and 3. for each indicatab. 1 indicators and ranks for criteria related to intrinsic quality. capital symbols in brackets correspond to the ones used for qi calculation in expression [1]. indicators for which only three levels could be defined are marked with an asterisk (*). indicatori e ranghi definiti per il criterio relativo alla qualità intrinseca. in maiuscolo e fra parentesi i simboli corrispondenti agli indicatori usati per il calcolodella qi secondo l’espressione matematica corrispondente [1]. gli indicatori per i quali è stato possibile definire solo tre ranghi vengono segnalati con un asterisco (*). intrinsic quality indicators ranks abundance/rarity (a) 4 only one example in the region 3 2-4 examples 2 5-10 examples 1 11-20 examples 0 >20 examples degree of scientific knowledge (k) 4 more than 1 ph.d. thesis; several papers in international/national journals 3 1 ph.d.thesis; at least 1 international or several national papers 2 1 national paper 1 some notes in national journals or articles in regional/local journals 0 no publications (*) usefulness as process 4 present, active process clearly visible/interpretable model/example (ex) 2 erosion/deposition features of present processes not clearly defined 0 fossil forms and/or deposits whose use for interpretation of past processes is difficult diversity of elements (geomorphic, 4 5 or more elements stratigraphic, paleontologic, etc) 3 4 elements(d) 2 3 elements 1 2 elements 0 only 1 element age (difficult, disputable criterion; 4 mesozoic or older it can be accepted that “other 3 cenozoicfactors being equal”, the older the 2 lower pleistocenebetter) (ag) 1 upper pleistocene 0 holocene (*) type locality? (t) 4 formally recognised type locality 2 secondary or reference type locality 0 not proposed as type locality association with historical, 4 presence of archaeological and several types of other elements archaeological, artistic heritage 3 archaeological and one additional type of element(ch) 2 archaeological remains 1 other, non-archaeological elements 0 no additional elements (*) association with other natural 4 outstanding landscape and valuable flora and fauna heritage (n) 2 outstanding landscape or valuable flora/fauna 0 valuable landscape state of conservation (c) 4 well preserved; no degradation 3 damage to minor characteristics 2 partially affected by human activities, but character of site remains 1 very affected by human activities; many characteristics degraded 0 intense degradation; loss of the site’s character 296 v.m. bruschi & a. cendrero tab. 2 indicators and ranks for criteria related to potential for use. capital symbols in brackets correspond to ones used for ui calculation in expression [1]. indicators for which only three levels could be defined are marked with an asterisk (*). indicatori e ranghi definiti per il criterio relativo al potenziale d’uso. in maiuscolo e fra parentesi i simboli corrispondenti agli indicatori usati per il calcolo della ui secondo l’espressione matematica corrispondente [1]. gli indicatori per i quali è stato possibile definire solo tre ranghi vengono segnalati con un asterisco (*). potential for use indicators ranks activities that can be carried out 4 5 or more activities (scientific, educational, tourism, 3 4 activitiesrecreation, object collecting, etc.) 2 3 activities(act) 1 2 activities 0 1 activity (*) observation conditions (o) 4 no limitations for entry; no visual obstructions 2 some physical limitations for access and/or viewing 0 physical difficulties for access and views obstructed by constructions vegetation, etc. accessibility (acc) 4 direct access through main road 3 access through local roads 2 access through unpaved roads or tracks 1 no road access but < 1 km from the nearest one 0 > 1 km from the nearest raod access extent (m2) (e) 4 > 106 3 105 106 2 104 105 1 103 104 0 < 103 proximity to service centres (s) 4 centre > 10,000 inhabitants and diversity of lodging and catering facilities within 5 km 3 locality > 10,000 inhabitants and some facilities within 5 km 2 5 – 20 km to lodging/catering facilities 1 20 – 40 km 0 > 40 km (*) socio-economic condition 4 per capita income and education > 15% above national average of the area (se) 2 national average 0 > 15% below national average tor a five-term (0 – 4) rank has been established. thus, indicators initially expressed by means of different, heterogeneous units are transformed into homogeneous categorical units. the following expression provides a “quality model” that can be applied to geosites using indicators presented above. vsgi = (qi+ui+pi)/3 [1] where: vsgi = value or merit of geosite (0-1); qi = intrinsic quality (0-1); ui = potential for use (0-1); pi = protection need (0-1). qi = (a×wa + k×wk + ex×wex + d×wd + ag×wag + t×wt + ch×wch + n×_wn + c×wc) / 4 ui = (act×wact + o×wo + acc×wacc + e×we + s×ws + se×wse) / 4 pi = (i×wi + t×wt + co×wco + p×wp + m×wm + l×wl) / 4 wi = weight of each indicator (σwi=1). the meaning of variables in the expression above is shown in tables 1, 2 and 3. of course, other “quality models” can be considered, such as: vsgi = ci (2qi+pi)/12 [2] where: ci = degree of conservation of geosites (0-4); qi = intrinsic quality of geosites (0-1); pi = potential for use of geosites (0-1). models assume that if a site ranks high with respect to the three qualities considered (scientific merit, social usefulness, urgency to act) can be considered as very valuable and should be included in inventories and protection plans. indicators and models proposed provide a means to express those intangible qualities by means of numerical indices, using transparent models that yield replicable results. the use of such indices should facilitate the incorporation of geosites into a variety of assessments for environmental decision making. 3. application to case studies the concepts and general procedure described above have been applied to two case studies, in order to test the validity of the method proposed. 297 3.1 geosites evaluation within the eia process. one case study deals with the evaluation of an existing inventory of geosites in an area of northern spain (fig. 1), as part of the eia process for a new motorway (bonachea et al., 2003). the procedure described here is an improvement of a former proposal; a more detailed description can be found in rivas et al. (1997). the inventory used is shown in figure 2. the value of each geosite was defined using a “quality model” slightly different to the ones presented above [1, 2]. vsgi = ci (2qi+ pi) / 48 [3] where: ci = degree of preservation (0 – 4); qi = intrinsic quality (0 – 4); pi= potential for use (0 – 4); vsgi = value of site (0-1) quality (q) was defined as: qi = wa × a + we × e + wk× k + wex × ex + wd × d where: a: relative abundance of the site’s type; d: diversity of geological/geomorphological elements; e: extent of the site; ex: value of site as example of geomorphological processes; k: degree of knowledge about site. w: weights of the factors considered; σ w = 1 potential for use (p) was obtained using a similar expression: pi = wac×ac + wo × o + ws × s + wh × h + wacc × acc where: geosite evaluation ... tab. 3 indicators and ranks for criteria related to potential threats and protection needs. capital symbols in brackets correspond to ones used for pi calculation in expression [1]. indicators for which only three levels could be defined are marked with an asterisk (*). indicatori e ranghi definiti per i criteri relativi alle potenziali minacce e alle necessità di protezione. in maiuscolo e fra parentesi i simboli corrispondenti agli indicatori usati per il calcolo della pi secondo l’espressione matematica corrispondente [1]. gli indicatori per i quali è stato possibile definire solo tre ranghi vengono segnalati con un asterisco (*). potential threats and protection needs indicators ranks inhabitants in the surrounding 4 > 100,000 (within a 25 km radius) (i) 3 50,000 – 100,000 2 25,000 – 50,000 1 10,000 – 25,000 0 < 10,000 (*) present or potential threats (t) 4 area with clear urban-industrial development or projects for new infrastructures 2 intermediate area; no immediate development projects but clear expectations for the near future 0 rural area; no expectations of urban-industrial-infrastructure development in the foreseeable future (*) possibility to collect objects 4 fossil, mineral or rock samples can be collected and site damaged (co) 2 objects can be collected without major damage to the site 0 no possibility to collect objects relationship to existing planning 4 area classified for urban, industrial or service uses (p) 3 no existing plans 2 site not protected but in area classified as rural in existing plans 1 site in area with some protection status in local/provincial plans 0 included within national park or other nationally protected space interest for mineral exploitation (m) 4 high mineral interest and current mining permits in the area 3 area with reserves of low-unitary value resources and where quarrying is currently allowed 2 area with reserves of low-unitary value resources but where quarrying is not currently allowed 1 some indications of mineral resources 0 no mining interest (*) land ownership (l) 4 site located in private land 2 both public and private property 0 public property fig. 1 location map. inquadramento geografico dell’area. 298 ac: types of activities that can be carried out on site; o: observation conditions; s: availability of services; h: number of inhabitants in surrounding area acc: accessibility; w: weights of factors considered; σ w = 1. table 4 shows the indicators and ranks (0 – 4 scale) established for the different parameters used to calculate the value of geosites (bonachea et al., 2003). table 5 presents, for all geosites analysed, values of the different factors considered as well as those for c, q, p and vsgi. to validate those results comparison with wellknown and socially appreciated geomorphologic landmarks in the region was made. geosites chosen as standards for comparison are the “ratón de guetaria” (guetaria mouse; fig. 3), probably the best known and most appreciated geomorphic landmark in the province of guipúzcoa, and two sites subject to restoration, one in vizcaya and one in cantabria (fig. 1). values obtained for those geosites using the same procedure are: ratón de guetaria (fig. 3): vsgi = 0.86 coastal area of somorrostro: vsgi = 0.5 karst of cabárceno (fig. 4): vsgi = 0.9 expenditure on restoration for the latter two sites was respectively 3 ×106 € and 12 ×106 € (restoration actions also included non-geomorphic elements). both the “ratón de guetaria” and “karst of cabárceno” are widely known and very much appreciated by local population. the “coastal area of somorrostro”, on the other hand, is less known and not so much valued. that is, informal, subjective perception by local population is coherent with numerical values obtained using the procedure described. moreover, if effort devoted to restoration is used as an additional external indicator of “social appreciation”, we can see that expenditure in cabárceno (vsgi = 0.9) was considerably higher than in somorrostro (vsgi = 0.5). this is also reasonably coherent with the systematic evaluation described, although by no means should be considered as an objective measure of the sites’ value, due to the different cost factors involved in restoration. comparison between vsgi and actual expenditure on restoration provides the basis for a rough translation of the intangible “geosite value” into monetary units. from the figures provided above an average “theoretical value” of about 10 ×106 € can be assumed for an ideal site with vsgi = 1. this can in turn be used to express impact on geomorphosites or geosites in general, using reductions or increases in the dimensionless vsgi as well as the “theoretical monetary loss or gain” implied (bonachea et al., 2003). an example of this is shown in table 5. if monetary values indicated above are accepted, “theoretical losses” would be 3.7 ×106 € and 8.9 v.m. bruschi & a. cendrero fig. 2 distribution of geosites in the study area for the vergara-eibar motorway sector. distribuzione dei punti d’interesse geologico nella zona interessata dal tratto d’autostrada vergara-eibar. fig. 3 the “ratón de guetaria” (guetaria mouse), prominent geomorphological landmark in the region. il “ratón de guetaria” (topo di guetaria), punto d’interesse geomorfologico significativo della regione. ×106 € for alternatives a and b respectively. in brief, although criteria used to obtain vsgi will not necessarily be accepted by everyone and indicators used for “external validation” of the process have a certain degree of uncertainty, it appears that the procedure proposed represents a useful means to obtain, at least, a “coarse-grain” image of the quality of geomorphosites. 299geosite evaluation ... tab. 4 indicators and ranks for the value of each geosite (expression [3]; bonachea et al., 2003). indicators for which only three levels could be defined are marked with an asterisk (*). indicatori e ranghi definiti per il calcolo del valore definitivo di ogni punto d’interesse geomorfologico (espressione matematica [3]; bonachea et al., 2003). gli indicatori per i quali è stato possibile definire solo tre ranghi vengono segnalati con un asterisco (*). criteria indicators rank 4 well preserved; no visible degradation degree of 3 some degradation; damage to minor characteristics preservation degree of preservation 2 part of its characteristics degraded (c) 1 very affected by human activities, many of its characteristics degraded 0 total degradation; loss of the site’s character 4 only one example in the region relative abundance of 3 2 – 4 examples the site’s type 2 5 10 examples (a) 1 10 20 examples 0 > 20 examples diversity of 4 5 or more geological/ 3 4 geomorphological 2 3 elements 1 2(d) 0 only 1 4 > 90% of the greatest sgi of the same kind extent of the site 3 70 – 90% (e) 2 30 – 70% 1 10 – 30% 0 < 10% (*)value of site as 4 present, active processes clearly defined example of 2 erosion/accumulation features of present processes not clearly definedgeomorphological 0 fossil forms and/or deposits whose use for extrapolation of past processes is difficultprocesses (ex) 4 more than one ph.d thesis and numerous articles in refereed national and international journals degree of knowledge 3 at least one ph.d thesis and/or more than one article in refereed international about site journals and/or various in national journals (k) 2 some articles in refereed national journals and/or one article in an international journal 1 some brief notes in national journals or some articles in regional-local journal 0 no existing publications 4 5 types of activities types of activities that 3 4 types of activities can be carried out on site 2 3 types of activities (ac) 1 2 types of activities 0 1 types of activities (*) observation 4 public property of land, no limitations of access, no visual obstructions conditions 2 limitations of access or partial visual obstructions (o) 0 private property or view obstructed by fences, vegetation, etc. 4 good services within 4 km availability of services 3 good services within 45 km (s) 2 incomplete services within 5 km 1 good services within 10 km 0 absence of services within 10 km 4 > 100,000 inhab. in a radius of 25 km number of inhabitants 3 50 – 100,000 inhab. in a radius of 25 km in surrounding area 2 25 50,000 inhab. in a radius of 25 km (h) 1 10 25,000 inhab. in a radius of 25 km 0 < 10,000 inhab. in a radius of 25 km 4 direct access via national/regional roads accessibility 3 direct access via local roads (acc) 2 direct access via tracks 1 < 1 km from a vehicle path 0 > 1 km from a vehicle path potential for use (p) intrinsic quality (q) 3.2 geomorphosite identification and ranking the second case study concerns the application and comparison of criteria to be used for identification and selection of geomorphosites for an inventory in the province of cantabria (fig. 1). identification and selection of geomorphosites are highly subjective tasks, necessarily based on the experience of experts and their familiarity with the area. this is a generally accepted part of the process but it is convenient to analyse the degree of coincidence between different experts, the criteria implicitly or explicitly used for selection and the degree of internal coherence of individual experts’ assessment. in the case study described identification and assessment of sites was carried out in four types of geomorphic systems: coastal, glacial, fluvial and slope. the analysis was performed separately for each one of them, in order to deal with a more homogeneous population of objects and make comparisons easier. the initial step in the identification process was an e-mail questionnaire sent to 24 local experts, in which they were asked to indicate their personal degree of expertise on the different types of geomorphic environments as well as to provide a ranked list of at least 10 sites for each one of them (tab. 6). an “experts database” was elaborated with the 14 replies received. an initial classification of sites was directly derived from those replies, by simple addition of ranks assigned to each site by the different experts, the most important site having a value of 10 and the least important 1. theoretical values would thus rank from 140 (a site identified by all experts and considered by all of them as the most important within its category) to 1 (a site named by only one expert and considered as the least important of its group). obviously, the first case is unlikely to appear. a second e-mail questionnaire was then sent to experts, asking them to indicate, for the two types of geomorphic environments they considered themselves more familiar with, four criteria (ranked by order of importance) they considered relevant for geomorphosite value assessment. values between 1 (least important) and 4 (most important) were assigned and weights derived initially by simple addition, as explained before. weights were then reduced to a 0 – 1 scale (tabs. 7 and 8). the following step was the establishment, by the work team, of indicators that allow the identification of three levels or degrees for each criterion (tab. 9). three levels were used because they can be defined quite objectively. value of geomorphosites was then calculated separately for each category (glacial, coastal, fluvial, slope) using the expression: n vg = σ ci × wi i = 1 where: vg = value of geosite 300 v.m. bruschi & a. cendrero n º. s it e n am e, s g i a e k e x d a c o s h a cc c q p v s g i ( p re ) v s g i ( p o st a ) v s g i ( p o st b ) 1 m eg at ur b id ite s, s an l or en zo 0. 80 0. 40 0. 40 0. 40 0. 00 0. 00 0. 80 0. 80 0. 60 0. 80 4. 00 2. 00 3. 00 0. 58 0. 58 0. 58 2 c re ta ce ou s fl ys ch , a ris tib ur u 0. 80 0. 40 0. 40 0. 40 0. 00 0. 00 0. 80 0. 80 0. 60 0. 80 4. 00 2. 00 3. 00 0. 58 0. 58 0. 58 3 d an ia n m ar ls , s an l or en zo 0. 80 0. 40 0. 40 0. 40 0. 00 0. 00 0. 80 0. 80 0. 60 0. 80 4. 00 2. 00 3. 00 0. 58 0. 58 0. 58 4 p ill ow -l av as , a rg at e 0. 80 0. 40 0. 40 0. 40 0. 20 0. 20 0. 00 0. 80 0. 60 0. 20 4. 00 2. 20 1. 80 0. 52 0. 52 0. 00 5 v ol ca ni c ro ck s, a rz ab al et a 0. 80 0. 40 0. 40 0. 40 0. 20 0. 00 0. 00 0. 80 0. 60 0. 00 4. 00 2. 20 1. 40 0. 48 0. 48 0. 48 6 v ol ca ni c b od ie s, ig ar at e 0. 80 0. 40 0. 40 0. 40 0. 00 0. 20 0. 40 0. 80 0. 60 0. 00 4. 00 2. 00 2. 00 0. 50 0. 50 0. 50 7 tr ac hy te fl ow s, m al za ga 0. 80 0. 40 0. 40 0. 40 0. 40 0. 00 0. 80 0. 80 0. 60 0. 80 4. 00 2. 40 3. 00 0. 65 0. 30 0. 30 8 q ua rr y, m al za ga 0. 80 0. 40 0. 40 0. 40 0. 00 0. 40 0. 80 0. 80 0. 60 0. 80 4. 00 2. 00 3. 40 0. 61 0. 65 0. 65 9 fo ld , u rk o 0. 60 0. 40 0. 40 0. 40 0. 00 0. 20 0. 40 0. 80 0. 60 0. 40 4. 00 1. 80 2. 40 0. 50 0. 50 0. 50 10 fo ld s, e ib ar 0. 60 0. 40 0. 40 0. 40 0. 60 0. 20 0. 40 0. 80 0. 60 0. 40 4. 00 2. 40 2. 40 0. 60 0. 60 0. 60 11 p ill ow -b re cc ia s, l a a sc en si ón 0. 60 0. 40 0. 20 0. 40 0. 60 0. 20 0. 40 0. 80 0. 60 0. 40 4. 00 2. 20 2. 40 0. 56 0. 50 0. 50 12 te ct on ic b re cc ia , u ga rr ia ga 0. 80 0. 40 0. 20 0. 40 0. 20 0. 20 0. 40 0. 80 0. 60 0. 40 4. 00 2. 00 2. 40 0. 53 0. 53 0. 53 13 c re ta ce ou s se ct io n, a ra ne 0. 80 0. 40 0. 20 0. 40 0. 00 0. 20 0. 40 0. 80 0. 60 0. 40 4. 00 2. 00 2. 40 0. 53 0. 53 0. 53 14 p ill ow -b re cc ia s, p la ce nc ia 0. 60 0. 40 0. 20 0. 40 0. 60 0. 20 0. 40 0. 80 0. 60 0. 40 4. 00 2. 20 2. 40 0. 57 0. 57 0. 57 15 o ut cr op , i tu rb e 0. 80 0. 40 0. 20 0. 40 0. 00 0. 00 0. 40 0. 80 0. 60 0. 40 4. 00 1. 80 2. 20 0. 48 0. 48 0. 48 t o ta l v al ue 8. 27 7. 90 7. 38 ta b . 5 in d ic at or v al ue s an d v s g i f or g eo si te s in t he a re a of t he v er ga ra -e ib ar m ot or w ay s ec to r. a : r el at iv e ab un d an ce ; e : e xt en t; k : d eg re e of k no w le d ge ; e x: g oo d e xa m p le o f p ro ce ss es ; d : d iv er si ty ; a c: a ct iv iti es ; o : o b se rv at io n co nd iti on s; s : a va ila b ili ty o f se rv ic es ; h : n um b er o f in ha b ita nt s; a cc : a cc es si b ili ty ; c : s ta te o f co ns er va tio n; q : q ua lit y s g i; p : p ot en tia l f or u se ; v s g i ( p re ): va lu e of s g i b ef or e m ot or w ay c on st ru ct io n, v s g i ( p os t a , b ): va lu e of s g i a ft er m ot or w ay c on st ru ct io n (a lte rn at iv es a a nd b ). in d ic at or i e v s g i p er i p un ti d ’in te re ss e ge ol og ic o ne lle z on a in te re ss at a d al s et to re d ’a ut os tr ad a v er ga ra -e ib ar na . a : ab b on d an za r el at iv a; e : es te ns io ne ; k : gr ad o d i co no sc en za ; e x: b uo n es em p io d i p ro ce ss o; d : d iv er si tà ; a c: a tt iv ità ; o : co nd iz io ni d ’o ss er va zi on e; s : p re se nz a d i s er vi zi ; h : nu m er o d i a b ita nt i; a cc : ac ce ss ib ili tà ; c : st at o d el la c on se rv az io ne ; q : q ua lit à d el p un to d ’in te re ss e ge ol og ic o; p : p ot en zi al e d ’u so ; v s g i ( p re ): va lo re d el p un to d ’in te re ss e ge ol og ic o p rim a d el la c os tr uz io ne d el l’a ut os tr ad a; v s g i ( p os t a , b ): va lo re d el p un to d ’in te re ss e ge ol og ic o d op o la co st ru zi on e d el l’a ut os tr ad a (a lte rn at iv e a e b ). 301geosite evaluation ... tab. 6 questionnaire sent to experts. scheda usata per il primo questionario proposto agli esperti. ci = value of criterion in site (in the three-term scale) wi = weight of criterion i values thus obtained are shown in table 10. a comparison was then made between the rank of geosites obtained directly from the initial evaluation by all experts and the one derived from the application of the expression above. table 11 shows the results obtained for coastal sites. the agreement between both ranks is very good for sites at the top of the scale (figs. 5, 6) and less satisfactory at lower levels, although the difference never exceeds 3 positions in the rank. table 12 presents a comparison between the ranks proposed by one individual expert and the same vg values of table 11. differences, as should be expected, are greater. more or less the same trend was observed when other individual assessments were compared with the vg rank. finally, in table 13 a comparison is presented between the rank initially proposed by one expert and vg obtained using the criteria proposed by that same expert. again, agreement is good at the top of the scale and not so good at lower levels. in this case the agreement is even better than in the other two examples, a logical result considering that we are comparing an expert with himself. however, it is clear that there is a certain inconsistency between the initial synoptic assessment and the one derived from the application of the criteria proposed by the same person. in the other words, when providing the overall assessment of sites the expert does not appear to be using exactly the same criteria he considers important for site evaluation. 4. final comments the examples above show that the analytical procedure described for the evaluation of geomorphosites provides results that are coherent with independent assessments. 302 v.m. bruschi & a. cendrero fig. 4 kárst of “cabárceno”. paesaggio carsico di “cabárceno”. fig. 5 dunes of liencres. sistema dunare di liencres. tab. 7 identification of sgi quality criteria. identificazione dei criteri di qualità per i punti d’interesse geomorfologico. expert no. criteria 1 2 3 4 5 6 is it inventoried? 4 state of conservation 3 4 illustrates active processes 2 3 3 2 3 size 3 2 4 4 4 related to human issues 2 2 2 good example of geomorph. evolution 1 4 3 observation conditions 1 1 1 1 1 that is, the “geomorphosite quality models” proposed can be used to obtain rankings of sites that coincide reasonably well with other, independent “value indicators”. this is the case forinformal appreciation of sites by the general public or expenditure on site rehabilitation. both can be considered as indicators of the value attached to those sites by society. results obtained with the analytical procedure also provide a reasonable coincidence with the subjective evaluation by groups of experts. the agreement is particularly good when high value sites are considered. nevertheless, a certain degree of inconsistency has been observed when it comes to compare what an 303geosite evaluation ... fig. 6 estuary of “san vicente de la barquera”. estuario di san vicente de la barquera. tab. 8 determination of weights for criteria in table 7. determinazione dei pesi per i criteri della tabella 7. criteria σς weight size 17 0.28 illustrates active processes 13 0.22 state of conservation 7 0.12 good example of geomorph. evolution 8 0.13 related to human issues 6 0.10 observation conditions 5 0.08 is it inventoried? 4 0.07 tab. 9 criteria ranks ( th reete rm scale). ranghi definiti per ogni criterio selezionato (scala a tre termini). 3 > 1.000.000 m2 a 2 10.000 – 1.000.000 size 1 < 10.000 m2 b 3 very active, clearly visible illustrates active processes 2 moderately active 1 inactive or barely visible c 3 perfectly preserved, no damage state of conservation 2 partly damaged but main features remain 1 very damaged d 3 main elements for interpreting geomorphological evolution present good example of 2 some features useful for interpreting geomorphological evolution geomorphological evolution 1 very limited or no possibility to interpret past evolution e 3 processes/features directly relevant for human activities related to human issues 2 possible implication with human activities 1 not relevant for human activities f 3 complete access and visibility observation conditions 2 some limitations for access/visibility 1 great difficulty for observation due to physical barriers g 3 in national inventory is it inventoried? 2 in local/regional inventories 1 non inventoried expert considers “should be important” (criteria) with what he “actually values as important” (direct ranking of sites). this type of inconsistency would probably be reduced if an iterative procedure, such as the delphi method, were used (balkey, 1969). in summary, the approach presented makes the procedure transparent, expressing criteria used in clear, unequivocal terms. those criteria are represented by the values (rank, points) for the different conditions each indicator can present as well as their weights (relative importance of indicators). the “quality models” used are based on a series of simple-to-assess categorical variables. results obtained using those models can therefore be replicated by any operator (provided the same criteria are accepted), thus significantly reducing the degree of subjectivity in the evaluation process. as the models provide results in numerical form, validation through comparison with independent assessments or indicators is greatly facilitated. total vsgi or other qualities such as “intrinsic quality”, “potential for use” o “protection need” can thus be represented by numerical values. this numbers do not strictly represent a measure, because they correspond to dimensionless indices, but can be considered as “point values” or “positions in a rank”. going back to the initial question presented in the title, the approached proposed provides a means to roughly “measure” some intangible geomorphosite values. nevertheless, the procedure needs to be improved, refined and more thoroughly validated. 304 tab. 10 value of coastal geomorphosites in cantabria. values in brackets correspond to criteria weights. valori definitivi dei punti d’interesse geomorfologico appartenenti al sistema costiero della cantabria. i valori fra parentesi corrispondono ai pesi definiti per i criteri. criteria a b c d e f g vgsite (0.28) (0.22) (0.12) (0.13) (0.10) (0.08) (0.07) ría de s.v. da la barquera 3 3 2 2 2 3 2 2.58 puntal de somo 3 2 2 2 2 3 2 2.36 ría de ajo 3 3 2 1 1 1 1 2.12 ría de t. menor 3 2 2 2 1 2 2 2.18 dunas de liencres 3 3 2 3 2 3 2 2.71 punta dichoso 2 3 2 1 2 2 2 2.09 plat. abrasión de la arnía 1 3 3 3 3 3 1 2.30 dunas de oyambre 2 3 1 3 2 2 2 2.23 rasas de t. mayor 3 1 3 3 1 3 2 2.29 dunas de sonabia 1 2 3 3 1 3 1 1.98 tab. 11 comparison between initial rank and vg (all experts). comparazione tra i valori iniziali (sondaggio) ed i valori ottenuti applicando il modello di qualità (vg). v.m. bruschi & a. cendrero acknowledgements support for this work was provided by the “fundación marcelino botín” (grant to viola maria bruschi) and project gets (contract erbfmr ct970162, tmr programme, european commission). references balkey n.c. (1969) the delphi method: an experimental study of group opinion the rand corp., santa monica, california. bonachea pico j., bruschi v.m., remondo j., gonzález305 tab. 12 comparison between initial rank (exp. nº. 14) and vg (all experts). comparazione tra i valori iniziali (sondaggio di un solo esperto, il nº 14) ed i valori ottenuti applicando il modello di qualità (vg). tab. 13 comparison between initial rank (exp. nº. 1) and vg (criteria of exp. nº. 1). comparazione tra i valori iniziali (sondaggio di un solo esperto, il nº 1) ed i valori ottenuti applicando il modello di qualità ed i criteri definiti dal medesimo esperto (vg). geosite evaluation ... díez a., salas l., bertens j., cendrero a., otero c., giusti c., fabbri a., ganzález-lastra j.r. & aramburu j.m. (2003) an approach for the incorporation of geomorphologic factors into eia of transportation infrastructures; a case study in northern spain geomorphology (accepted, 2003). cendrero a. (2000) patrimonio geológico; diagnóstico, clasificación y valoración in: jornadas sobre patrimonio geológico y desarrollo sostenible. ministerio de medio ambiente, serie monografías, pp. 23-37. martini g. (2000) patrimonio geológico y geoturismo in: d. barettino, w.a.p. wimbledon, e. gallego (eds), patrimonio geologico: conservación y gestión., pp. 161 170. mohr l.b. (1988) impact analysis for program evaluation pacific grove, brooks & cole, california. panizza m. & piacente s. (1999) il concetto di “bene” nel paesaggio fisico in: m. bertacchini, c. giusti, m. marchetti, m. panizza & m. pellegrini (eds.), i beni geologici della provincia di modena, artioli editore, modena, pp. 8-9. poli g. (1999) geositi testimoni del tempo. fondamenti per la conservazione del patrimonio geologico collana naturalistica del servizio paesaggi, parchi e patrimonio naturale, regione emilia romagna, 264 pp. reynard e., holzman c., guex d., summermatter n. (2002) géomorphologie et tourisme actes de la réunion annuelle de la societé de géomorphologie (ssgm), 21 23 september 2001, finhaut, lausanne. institut de gèographie, travaux et recherches. 24, pp. 1 10. rivas v., rix k., frances e., cendrero a., brunsden d. (1997) geomorphological indicators for environmental impact assessment; consumable and nonconsumable geomorphological resources geomorphology. 18 (3-4), pp. 169-182. 306 v.m. bruschi & a. cendrero amq abs pini et al palcom 155-159.pub available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 155 159 quantitative reconstructions of quaternary climates using pollen: assumptions, numerical techniques and calibration datasets roberta pini 1, federica badino 1,2, mattia de amicis 3, giulia furlanetto 3, valter maggi 3, cesare ravazzi 1, francesca vallè 3 1 idpa cnr, res. group on vegetation, climate and human stratigraphy, laboratory of palynology and palaeoecology, milano, italy 2 university of bologna, dept. of cultural heritage, bologna, italy 3 dept. of environmental and earth sciences, university of milano bicocca, milano, italy corresponding author: r. pini <roberta.pini@idpa.cnr.it> abstract: pollen assemblages are increasingly used for quantitative reconstructions of past climate parameters. estimated temperatures and precipitations can be coupled with palaeoecological records to make their interpretation more robust. although the potential of numerical techniques is suggested by published and ongoing researches, improvements in the calibration datasets used to compare fossil and modern pollen spectra are needed. current limitations within the european modern pollen database concerning data quality and density are discussed. attention is given to altitudinal training sets of modern pollen rain vegetation climate terrain parameters, allowing a better understanding of pollen dispersal and deposition across elevational gradients. keywords: quaternary, northern italy, climate, pollen, quantitative reconstructions, altitudinal training sets 1. introduction pollen is used since the early xxth century as a tool to reconstruct vegetation and environments and their reaction to climate change and human pressure. the potential of pollen spectra as descriptors of past climate conditions is gaining increasing interest in the quaternary community (juggins and birks, 2012). new pollen records are produced every year from different ecological and climatic regions, thanks to the exceptional fossilization potential of palynomorphs and to the possibility of identifying them with high taxonomic resolution. coupling traditional pollen-stratigraphical researches with quantitative climate reconstructions based on the same compilation of data can indeed provide new hints for the interpretation of palaeoecological records and improve our understanding of man-environment interactions. statistical approaches based on regression calibration and modern analogues were developed for different types of microscopic biological remains (chironomid: eggermont and heiri, 2011; chrysophytes: kamenik and schmidt, 2005; cladocera: brodersen et al., 1998; diatoms: birks et al., 1990; pollen: see references cited in seppä et al., 2004) and they are currently used for quantitative estimations of past temperatures, precipitation, chemical and trophic state of water bodies. to do so, the development of transfer functions connecting modern calibration data sets and fossil ones is needed. as far as pollen is concerned, the european modern pollen database (empd; davis et al., 2013) is used as source for statistically-based comparisons between fossil and modern pollen spectra. although the relevance of this dataset is undeniable, several points need to be fixed in order to provide the eurasian pollencommunity with an ecologically sound and complete tool for palaeoclimate reconstructions. this contribution will focus on principles and techniques of quantitative climate reconstructions using pollen, the relevance of such reconstructions for our understanding of past ecological systems and on advantages/ disadvantages of current calibration datasets. 2. methods: a short review on principles and techniques of quantitative climate reconstructions based on pollen some biological assumptions support the use of pollen as a proxy of climate. as regional vegetation is influenced by climate, we might expect that the climate variability plays a relevant role not only in the extent of vegetation communities and their composition, but also on pollen productivity and deposition modes. the validity of this hypothesis was checked by several authors (sjögren et al., 2006 and references therein). pollen proportions and pollen accumulation rates (par) can indeed be considered as a response of vegetation and depositional processes to climate conditions. before using pollen as climate descriptor, a few requirements need to be met: (1) a calibration training set of pollen deposition and associated temperature/precipitation data must be available for a given climate gradient; (2) the relationships between pollen descriptors and modern climate parameters must be modelled; (3) quantitative climate parameters can be estimated through the application of the model (transfer function) to fossil pollen data. requirement #1 may be fulfilled by subsets extracted from the european modern pollen database (fig. 1). requirements #2 and #3 are tackled through numerical techniques of regression-calibration and search for https://doi.org/10.26382/aiqua.2018.aiquaconference modern analogues, namely wa (weighted averaging), wa-pls (weighted-averaging partial least square) and mat (modern analogue technique) (fig. 2). 3. the european modern pollen database: its content and some main limitations more than 4200 modern pollen samples with associated climate data are stored in the current empd version (fig. 1). samples cover a large part of eurasia, from portugal to siberia, from fennoscandia to the near east; a large variety of ecosystems is represented. the effort done by davis et al. (2013) to make this database available to the scientific community is impressive and no progresses in the direction of using pollen as a proxy of climate could be possible without this calibration set. nevertheless, the empd has some limitations; they do not hamper its use, although refinements would greatly increase its potential. the main disadvantages are here listed: 1) uneven quality of the taxonomic identification of pollen grains. unfortunately there is no common rule on the degree to which palynologists identify pollen grains; this results in a great issue when pollen spectra counted by hundreds of different analysts are gathered in a common dataset. just two examples: keeping the pollen of climate-sensitive timberline species such as pinus cembra separated from pinus sylvestris/mugo and alnus viridis from alnus glutinosa/incana can greatly enhance the quality of pollen -reconstructed climate series in the high-altitude alps (furlanetto et al., unpublished data). at an alpine scale, only 68 modern pollen spectra out of the available 270 comply these rules. 2) uneven spatial and temporal distribution of the sampling sites. fig. 1 shows that, despite the wide latitudinal and longitudinal extents covered by the empd, large areas still have poor or no sample coverage. this is the case, for example, of the area between the balkans and the carpathians, the ukrainian plains, western siberia, the mediterranean islands and the po plain. some of the ecosystems represented in these areas (garrigue, steppes, foreststeppe ecotones and taiga) are not sufficiently sampled in the empd, resulting in an incomplete representation of the ecological gradient of several plant 156 fig. 1 geographical extent of the european modern pollen database (empd: davis et al., 2013). red dots indicate the location of the 4270 sampling sites superimposed on the spatial distribution of global ecological zones (gez) proposed by the global forest resources assessments (grfa) of fao (http://www.fao.org/forest-resources-assessment/remote-sensing/global-ecological-zones-gez/en/). metadata, as well as pollen and climate data associated to each empd site shown in the map can be downloaded at http:// www.europeanpollendatabase.net/wiki/doku.php?id=empd_download_database. pini r. et al. 157 species. 3) data stored in the empd do not provide a consistent picture of pollen dispersal along mountain altitudinal gradients of eurasia, given the limited number of samples collected from the same catchment trunk. the issue of long-distance transport of pollen is well known to researchers working in mountain areas and it must be carefully considered when using pollen data for palaeoenvironmental reconstruction and inferences on past climate. to overcome this issue, the development of local altitudinal training sets is needed (see section 4). 4) variations of pollen deposition throughout sedimentary processes and the effects of human activities on the accumulation of microbiological particles are poorly accounted by empd sampling. long-distance floated and airborne associations of alluvial, marine and aeolian environments are almost not represented quantitative climate reconstructions using pollen fig. 2 schematic representations of the materials and methods involved in a quantitative climate reconstruction based on pollen grains (redrawn and modified after juggins and birks 2012). modern pollen deposition can be analyzed in different typologies of samples (mosses, core tops, artificial pollen traps, soil, litter): these data are accompanied by information on site-specific temperature and precipitation. the calibration dataset used for the development of paleoclimate transfer functions is composed by thousand of modern sites. transfer functions are then applied to fossil pollen spectra for the reconstruction of past climate parameters. in the empd. those issues have to be carefully considered when working in archaeological sites and cultural landscapes. 4. altitudinal training sets of modern pollen and climate for proxy calibration along mountain valleys we recently developed two calibration sets of modern pollen rain vegetation cover climate data terrain parameters in the western and central alps (la thuile and brembana valleys, respectively; badino, 2016 and furlanetto et al., submitted); in the same valleys palaeoecological researches on high-altitude mires were in progress. at each sampling site we carried out vegetation surveys and monitoring of modern pollen deposition through the analysis of moss samples. site-specific temperature and precipitation series, covering the 19512015 period, were reconstructed for each sampling site by means of the anomaly method (new et al., 2000; mitchell and jones, 2005) as described in brunetti et al. (2012). the aim of such big efforts was to obtain valleyspecific proxies’ calibration along altitudinal transects and to improve our knowledge on the relationships between the selected parameters. data collected with our two alpine calibration sets were used, along with the empd data, for temperature and precipitation reconstructions of holocene pollen records from two high-altitude sites in the continental western alps (badino et al., 2018) and in the oceanic external alpine chains of lombardy (furlanetto et al., in progress). pollen-inferred climate reconstructions show a significant comparison with independent proxies of climate such as the extent of some alpine glaciers (holzhauser et al., 2005; le roy et al., 2015), pollen and chironomid-inferred temperature records from the swiss and austrian alps (wick et al., 2003; ilyashuk et al., 2011), isotopic records from alpine speleothems (luetscher et al., 2011; fohlmeister et al., 2013) and the sequence of cold periods in the alps (zoller et al., 1966; patzelt and bortenschlager, 1973). 5. conclusion similarly to other biological remains, pollen can be used for quantitative reconstructions of past temperatures and precipitations. in the past decade, progresses were recorded in the numerical techniques employed for this purpose and in the digital platforms where specific software packages are executed. for robust climate reconstructions, a thorough knowledge of the relationships between modern pollen deposition, temperature and precipitation is mandatory. the availability of continental-wide calibration sets (european modern pollen database empd, north american pollen database napd, east asian pollen database eapd, african pollen database apd, etc.) is acknowledged. improvements in the quality and quantity of data stored in these datasets are needed, to increase the performance of the modern-to-fossil transfer functions for past climate reconstructions. acknowledgements this research is partially funded by the cnr-dta project of interest nextdata, a national system for the retrieval, storage, access and diffusion of environmental and climate data from mountain and marine areas (www.nextdataproject.it). references badino f. (2016) holocene vegetation and climate variability as recorded in high-altitude mires (western italian alps). unpublished phd thesis in environmental sciences, univ. milano-bicocca, milano, italy, pp. 145. badino f., ravazzi c., valle' f., pini r., aceti a., brunetti m., champvillair e., maggi v., maspero f., perego r., orombelli g. (2018) 8800 years of high-altitude vegetation and climate history at the rutor glacier foreland, italian alps. evidence of middle holocene timberline rise and glacier contraction. quaternary science reviews, 185, 41-68. birks h.j.b, line j.m., juggins s., stevenson a.c., ter braak, c.j.f (1990) diatoms and ph reconstruction. philosophical transactions of the royal society of london series b, 327, 263-78 brodersen k.p., whiteside m.c., lindegaard c. (1998) reconstruction of trophic state in danish lakes using subfossil chydorid (cladocera) assemblages. can. j. fish. aquat. sci., 55, 1093-1103. brunetti m., lentini g., maugeri m., nanni t., simolo c., spinoni j. (2012) projecting north eastern italy temperature and precipitation secular records onto a high-resolution grid. physics and chemistry of the earth, 40-41, 9-22. davis b.a.s., zanon m., collins m., mauri a., bakker j., barboni d., barthelmes a., beaudouin c., birks h.j.b., bjune a.e. et al. (2013) the european modern pollen database (empd) project. vegetation history and archaeobotany, 22, 521-530. eggermont h., heiri o. (2011) the chironomidtemperature relationship: expression in nature and palaeoenvironmental implications. biological reviews, 87, 430-456. fohlmeister j., vollweiler n., spötl c., mangini a. (2013) comnispa ii: update of a mid-european isotope climate record, 11 ka to present. the holocene, 23 (5), 749-754. holzhauser h., magny m., zumbühl h.j. (2005) glacier and lake-level variations in west-central europe over the last 3500 years. the holocene, 15 (6), 789-801. kamenik c., schmidt r. (2005) chrysophyte resting stages: a tool for reconstructing winter/spring climate from alpine lake sediments. boreas, 34. 477489. ilyashuk e.a., koinig k.a., heiri o., ilyashuk b.p., psenner r. (2011) holocene temperature variations at a high-altitude site in the eastern alps: a chironomid record from schwarzsee ob sölden, austria. quaternary science reviews, 30 (1), 176-191. juggins s., birks h.j.b. (2012) quantitative environmental reconstructions from biological data. in (birks et al., eds.): tracking environmental change using lake sediments. data handling and numerical 158 pini r. et al. techniques. chapter 14, springer, the nedertlands., 431-494. luetscher m., hoffmann d.l., frisia s., spötl c. (2011) holocene glacier history from alpine speleothems, milchbach cave, switzerland. earth and planetary science letters, 302 (1), 95-106. mitchell t.d., jones p.d. (2005) an improved method of constructing a database of monthly climate observations and associated high-resolution grids. international journal of climatology, 25, 693-712. new m., hulme m., jones p. (2000) representing twentieth-century space-time climate variability. part ii: development of 1901-96 monthly grids of terrestrial surface climate. journal of climate, 13, 2217-2238. sjögren p., van leeuwen j.f.n., van der knaap w.o., van der borg k. (2006) the effects of climate variability on pollen productivity, ad 1975-2000 recorded in a sphagnum peat hummock. the holocene, 16(2), 277-286. wick l., van leeuwen j.f., van der knaap w.o., lotter a.f. (2003) holocene vegetation development in the catchment of sägistalsee (1935 m asl), a small lake in the swiss alps. journal of paleolimnology, 30 (3), 261-272. zoller h., schindler c., röthlisberger h. (1966) p o s t g l a z i a l e g l e t s c h e r s t ä n d e u n d klimaschwankungen im gotthardmassiv und vorderrheingebiet. verh. naturforsch. ges. basel, 77 (2), 97-164. 159 quantitative climate reconstructions using pollen ms. received: may 4, 2018 final text received: may 16, 2018 160 imp.farabollini& proposal for preservation and protection of the marche region mud volcanoes (central italy) piero farabollini1, marco materazzi1 & gianni scalella2 1dipartimento di scienze della terra università di camerino 2professional geologist via vezzelli, 1 63025 montegiorgio (ap) abstract: p. farabollini et al., proposal for preservation and protection of the marche region mud volcanoes (central italy). (it issn 0394-3356, 2005). have been in the past the subject of several studies by different authors; mentioned in classical scripts, they have been treated more in detail starting from the 17th century in naturalistic studies published by scientific academies or cultural associations. in the marchean region, these phenomena have been observed only in the peri-adriatic sector where pliocene and pleistocene formations crop out; they are well represented with respect to typology, number and extension. the present paper proposes several strategies for their preservation and protection: in particular these aim to avoid the characteristic morphologies, produced by leaking mud (also several times per year in some cases), being suddenly demolished by anthropic or natural agents. mud leakage generally occurs on a flat surface called “piano della salsa” prevalently on a thalweg or along a very gentle portion of the slope. typical, in mud volcano morphology, is the presence of one or more cones of different height and extension with emission of mud with different fluidity; sometimes natural boundaries exist and the leakage remains confined inside a depression, but in other cases the mud emissions can reach the hydrographic network. the marches region administration, as those of other italian regions, have no rules yet (except for some indications in the pparregional plan for landscape and the environment) for preventing and protecting these geo-sites. the procedure for safeguarding them should start from an analysis of the territory and a study of its resources, in particular defining characteristics, potential risks, and the objectives to be reached; in addition, it should formulate proposals for their use and enhancement, also indicating possible thematic routes (geological and geomorphologic pathways) in particularly significant areas. riassunto: p. farabollini et al., proposte per la conservazione e tutela dei vulcanelli di fango delle marche (italia centrale). (it issn 0394-3356, 2005). i “vulcani di fango” o “vulcanelli di fango” o “salse”, sono stati oggetto, in passato, di studi da parte di numerosi autori; se ne ritrovano tracce a partire dagli scrittori classici e, più diffusamente, dal ‘600 in poi con la ripresa dell’attività conoscitiva degli aspetti naturalistici da parte delle accademie scientifiche e delle associazioni culturali. i vulcanelli di fango, nella loro configurazione tipica, sono stati osservati nella regione marchigiana solamente nell’area periadriatica, caratterizzata dall’affioramento di depositi terrigeni pliocenici, anche se ben rappresentati, sia come tipologia che come numero che come estensione. per citarne solamente i maggiori, si ricordano quelli presenti nelle marche centro-settentrionali, nei pressi di maiolati spontini (an) e san paolo di jesi (an); oppure quelli nelle marche centro-meridionali presenti nei pressi di petriolo e loro piceno (mc), nei pressi di montegiorgio (ap), falerone (ap), offida (ap) e nelle vicinanze del monte dell’ascensione (ap). nel presente lavoro, oltre a riportare alcuni dati desunti da osservazioni effettuate sui vulcanelli di fango dell’area delle marche meridionali (offida), si propongono alcune azioni volte alla loro conservazione e tutela in quanto, nonostante le emissioni si ripetano per diverse volte nell’arco di un anno, anche se in maniera discontinua nel corso di più anni, le forme originate dal fango fuoriuscito, vengono quasi sempre demolite dagli agenti esogeni e, soprattutto, dall’azione dell’uomo, pochissimo tempo dopo la loro formazione. le emissioni fangose avvengono in genere su una superficie pianeggiante chiamata “piano della salsa”; in quasi tutti i casi osservati, esse risultano presenti sul fondovalle e/o su superfici pianeggianti che interrompono il pendio e indipendente dal reticolo idrografico presente; tuttavia non mancano casi, peraltro molto rari, in cui invece è possibile osservarle lungo il talweg del reticolo idrografico secondario. la regione marche, così come la quasi totalità delle regioni italiane, ad eccezione di alcune indicazioni contenute nel cosiddetto ppar (piano paesistico ambientale regionale), non è dotata di norme che prevedano in qualche modo azioni di conservazione e tutela di tali geositi. il procedimento per giungere alla salvaguardia dei geosito dei “vulcanelli di fango”, e delle aree ad esse connesse, dovrebbe prendere inizio dalla fase di analisi del territorio e delle sue risorse, che valuti le aree in base agli aspetti di ogni singolo sito ed alla sua vocazione, individui le minacce e ne definisca gli obiettivi da perseguire e che, infine, indichi le proposte di fruizione e valorizzazione di ogni geosito, includendo anche la possibilità di individuare percorsi tematici specifici (sentieristica geologico-geomorfologica) per zone particolarmente significative. tale piano potrebbe risultare composto dalle seguenti fasi: • fase di analisi; • fase di valutazione e definizione; • fase propositiva (di tutela e di valorizzazione). in particolare, gli strumenti per la tutela e la gestione di questo peculiare geosito potrebbero essere rappresentati da: • ripristino delle condizioni naturali dell’affioramento e promozione di attività di conservazione del geosito; • pannelli di avvicinamento e/o segnalazione del luogo mentre, sul posto, pannelli interpretativi che spiegano il fenomeno che si ha davanti, la sua genesi e la sua evoluzione spazio-temporale, anche con ricostruzioni 3d del suo stato iniziale confrontato con quello attuale; • zona di sosta, supportata da idonea tabellazione esplicativa, strutturata in maniera tale da rappresentare un polo di attrazione alla stessa stregua di un museo naturale all’aperto. key words: mud volcanoes, pliocene sediments, periadriatic area, defence and preservation, marches region. parole chiave: vulcanelli di fango, sedimenti pliocenici, fascia periadriatica, tutela e conservazione, regione marche. il quaternario italian journal of quaternary sciences 18(1), 2005 volume speciale, 179-184 180 p. farabollini et al. 1. introduction mud volcanoes (also known as “vulcanelli di fango”, “salse”, “maccalube”, or “bollitori”) have always been the object of study, both on account of their particular conformation and morphology and of the curiosity and, in some cases, the fear that they can cause in society. mention of them can be found in works by classical writers (marinelli, 1904; biasutti, 1907; bonasera, 1952; damiani, 1964), and more widespread accounts are present beginning from the 17th century with the revival of interest in natural phenomena on the part of scientific academies and cultural associations. to explain the genesis of these phenomena, which can display different morphological aspects and characteristics according to different geological and hydrogeological conditions, various hypotheses have been put forward regarding the regional seismic activity, the presence of gas, the rainfall regime, the morphological and geohydrological conditions of the area surrounding the mud volcanoes, etc. (marinelli, 1904; biasutti, 1907; bonasera, 1952; damiani, 1964; nanni & zuppi, 1986; martinelli, 1999; scalella, 2000). more in particular the presence of these phenomena in the area, has been related (bonasera, 1952; damiani, 1964; nanni & zuppi, 1986), to the uprising of deep hot waters along preferential lines (faults and/or joint systems, structural boundaries, etc.). in their typical configuration, the mud volcanoes in the marches region have been observed only in pliocene sediments; to mention only the major phenomena: those in the central-northern marches are in the neighborhood of maiolati spontini and s. paolo di jesi (in the province of ancona); those in the centralsouthern marches are near petriolo and loro piceno (province of macerata), and montegiorgio, falerone, offida and the monte dell’ascensione (province of ascoli piceno). the mud volcanoes present in offida area (province of ascoli piceno) are studied and described in this paper. moreover it proposes several strategies for the preservation and protection of the marche region mud volcanoes (fig.1). the presence of these mud-emission vents offers a wide view of the different mud volcano morphologies and typologies, which even though not presenting particularly exciting characteristics, all the same are an environmental heritage which is extremely vulnerable, above all since the ever increasing anthropic activity, especially of an agricultural kind, is rapidly canceling it. 2. geological and hydrogeological setting of the marche region mud volcanoes mud volcanoes have only been found in the periadriatic area where pliocene-pleistocene terrigenous deposits exclusively crop out. from the geological standpoint, the peri-adriatic area is characterized by a stratigraphic succession typical of one or more transgressive-regressive cycles, made up of alternations of conglomeratic, arenaceous, and arenaceous-pelitic deposits, often with considerable facies variation, both laterally-vertically and longitudinally in transgressive contact, with frequent onlap joints, with pliocene pelitic and pelitic-arenaceous deposits cropping out in the innermost areas (centamore & deiana, 1986; ori et al., 1991). the thickness of the deposits, also determined during petroleum and hydrogelogical prospecting research (eni, 1972), reaches 1500 to 2000 m in the westernmost portion and 3500 to 4000 m in the easternmost one. this sedimentary succession represents the foredeep filling sediments, migrating little by little eastward, or else piggy-back-type basins (ori et al., 1986; ori et al., 1991). it is affected by small-sized thrusts placed on the top of the carbonatic succession, if not indeed inside the pliocene deposits themselves (argnani et al., 1991). in the majority of cases, these are not outcropping thrusts, and so at the surface the setting is almost always a monoclinal one (fig. 2). however, some positive structures are present, such as the polverigi anticline and the so-called coastal ridge which includes, amongst other things, the conero and porto san giorgio structures (bigi et al., 1995). the quaternary tectonic activity can be identified above all in the quaternary deposits that closed the plio-pleistocene cycle; these, in addition to displaying considerable reduction in the thickness of the series in the proximity of the anticline structures (porto san giorgio), prove to be dislocated both by direct and inverse faults. from the hydrogeological standpoint, the system of folds, faults, thrusts, and fracture zones that characterizes all the peri-adriatic area, gives rise to a complex geological-structural feature from which are derived different smalland large-scale hydrogeological structufig. 1 – location of mud volcanoes in the marches region and in the offida area. black line indicates the stratigraphic transition from the miocene to the plio-pleistocene. white triangles indicate main areas affected by mud vent phenomena. ubicazione dei vulcanelli di fango della regione marche e dell’area di offida. la linea nera rappresenta il passaggio stratigrafico miocene-plio/pleistocene. i triangoli bianchi indicano le maggiori aree di emergenza dei vulcanelli di fango. 181proposal for preservation ... res. the former can give rise to surface-type water circulation, considerably variable both in trend and amount, conditioned by prevalently local morphological and bedding factors; instead, the latter generally generate a deeper regional-type circulation, uniform in direction of flow and amount, and mainly regulated by tectonic and structural factors. with respect to water springs, in the stratigraphic sequences characterized by intercalations of arenaceous, arenaceous-conglomeratic, arenaceous-pelitic, and pelitic-arenaceous units, the numerous perennial water springs testify to the presence of aquifers inside the permeable units and that are mainly filled by rainfall (scalella, 1996; nanni & vivalda, 1998). as for the structural setting, the water circulation in the arenaceous horizons can even reach considerable depths and come into contact with the brackish and salt waters present in the miocene and pliocene deposits (eni, 1972). according to some authors (nanni & zuppi, 1986; nanni & vivalda, 1998), arenaceous bodies belonging to the lower and middle pliocene sequence are frequently saturated with brackish and salt waters, and more rarely with freshwater, while the latter prevails in pleistocene deposits. 3. morphological characteristics of the mud vent phenomena in the offida area the mud vent phenomena and other characteristic morphological features (flows, fractures, cones, etc.) are essentially found in the fosso del lago valley bottom, in the point where the bed widens out and displays a decidedly asymmetric shape due to the monoclinal bedding of the bedrock (fig. 3). generally, this area, notwithstanding the considerable farming activities practiced there, can almost always be recognized by its vegetation which, at the point of mud emission, is always more luxuriant, due to the water permanence. the mud volcano morphology is extremely variable and in continuous evolution. long-term observations, apart from evidencing a more intense activity in the periods of greater rainfall, have shown that with the passing of the years new mud vents can open up, at times with the formation of new small cones. in particular, for almost all the phenomena observed in the marches region, the morphology of the areas with mud volcanoes is characterized by the existence of a zone where one or more emission point(s) are located (with the presence of emitted mud) and by one or more small cones of different height and extent, at the summit of which mud of varying fluidity is emitted (fig. 4). mud emission generally occurs over a flat surface, called “piano della salsa”; in most cases, it occurs on the valley bottom and/or on nearly flat morphologies that interrupt the slope. it generally leads to the formation of a cone, usually circular in shape, to the presence of topographic surfaces with reduced angle of slope, and with a good speed of emission and a fair density of mud emitted. in some cases, when their density is higher, the emission itself, is confined inside a depression that prevents its propagating, whereas in others it develops by means of flows that sometimes ends upfi g. 2 – s ch em at ic g eo lo gi ca l c ro ss s ec tio n of t he p er ia d ria tic a re a: m = m es si ni an ; p 1 = l ow er p lio ce ne ; p 2 = m id d le p lio ce ne ; p 3 = u p p er p lio ce ne ; q = q ua te rn ar y (m od ifi ed fr om s ca le lla , 19 96 ). s ez io ne g eo lo gi ca s ch em at ic a d el l’a re a p er ia d ria tic a: m m es si ni an o; p 1 p lio ce ne in fe rio re ; p 2 p lio ce ne m ed io ; p 3 p lio ce ne s up er io re ; q q ua te rn ar io (m od ifi ca ta d a s ca le lla , 1 99 6) . 182 into the hydrographic network. often, the landforms originating from the mud emitted, above all due to their intermittent nature, are demolished by external agents and above all by the action of man (fig. 3). in addition to displaying varying size, the mud volcanoes in the study area are characterized by an intermittent activity with time intervals even of a few years between one emission and another. this activity means that whenever the phenomenon occurs, it is immediately remodeled by anthropic activity that, for agricultural purposes, tends to restore a surface that can be utilized within a brief period of time. in fact, for many of the situations occurring in the marches region, the immediate actions of man have always prevented the development of these phenomena, and even canceled the least evidence of such activity, and at times not even allowing the formation of new emissions. 4. hypotheses of fencing, management, and safeguarding of the mud volcano areas of marche region in this context of an extremely various typology of mud volcanoes present in the marches region territory, we wish to propose certain actions aimed at preserving and safeguarding them, also on the basis of what has been done for those in the municipality of fiorano modenese, where specific regional regulations in 1982 set up the natural reserve of “salse di nirano”. the marches region, as almost all the other italian regions, with the exception of certain guidelines contained in the law called ppar, is not equipped with legislation that foresees in some way actions of preservation and safeguard for these geosites. however, inspired by the above-mentioned laws, the marches region has published a volume “le emergenze geologiche e geomorphologiche della regione marche” (geological and geomorphologic emergency in the marches) (various authors, 1991) in which the geosites were listed, using very simplified and easy-to-read census forms, as an important characteristic element of the marchean geological and geomorphological landscape, and thus worthy of being “respected”. in addition to these actions of characterizing the geosites, establishing them at a level of geological diversity (bertacchini et al., 1999; farabollini et al., 2002; sampaolesi & farabollini, 2002), and spreading information on them, it is of paramount importance to identify specific actions aimed at: • restoring natural outcrop conditions; • promoting activities to preserve the geosites; • defining specific regional legislation for preserving and safeguarding them. with the aim of attaining a really binding set of legislation for preserving these particular features, a greater awareness of their importance, but above all of their fragility, is obviously needed, not only on the part of technicians and administrators operating in the field of territorial planning, but also on that of the social community itself. the procedure to be followed for achieving an adequate safeguard of the geosites in question should start from the phase of analyses of the territory and its resources, such as to assess the area on the basis of the aspects and utilization potential of each site, identifying the threats and defining the objectives to pursue, and, finally, indicating the proposed means of exploiting and appraising it. the last of these stages would deal with the possibility of identifying specific thematic routes (geological-geomorphological trails) for the particularly significant ones, both from the tourist and educational-scientific standpoints. thus, each individual area characterized by the presence of mud volcanoes could be defined, in zones of various levels of environmental protection: fig. 3 – panoramic view of mud volcanoes area of offida (june 1996). the considerable farming activity should be noted; this led to the disappearance of the mud volcano morphology, even though it can still be recognized by the more luxuriant vegetation due to the water permanence. foto panoramica delle zone dei vulcanelli di fango di offida (giugno 1996); da evidenziare la notevole attività antropica che ha portato alla scomparsa della morfologia del vulcanello di fango, anche se riconoscibile a causa della vegetazione più lussureggiante dovuta a ristagni di acqua. p. farabollini et al. 183 1. areas of total protection: to be set up exclusively in a significant setting where mud volcanoes can evolve naturally; in these areas, all types of activity would be forbidden. 2. areas of planned protection: these areas would include the previous group, and only those activities for conserving, managing and appraising the geosite would be allowed. 3. protected areas: these would include the areas of the previous two groups and aim at a more significant outward-going context in which non-destructive farming activities would be permitted. the above-mentioned proposal to fence the areas implies that the owners of the land where the geosite is located, and all the protected areas, should keep more or less large areas of land uncultivated, and additional farming practices should be carried out with respect to those followed beforehand (for instance, a different drainage pattern for collecting rainwater would be required). therefore, the legislation could contain norms for safeguarding the rights of the owners, with funds aiming at compensating them for any loss of income and/or additional expenses they had to meet due to modified farming practices. in this way, also for the mud volcanoes in the marches, a specific legislation would be set up aimed at safeguarding and preserving, so that these geosites that for years have had the role of being “prodigious natural phenomena”, will not disappear for ever, not even from human memory. references argnani a., artoni a., ori g.c. & roveri m. (1991) l’avanfossa centro-adriatica: stili strutturali e sedimentazione studi geol. camerti, vol. spec. crop 03, pp. 371-381. bertacchini m., giusti c., marchetti m., panizza m. & pellegrini m. (eds.) (1999) i beni geologici della provincia di modena artioli ed., modena, 104 pp. biasutti r. (1907) le salse dell’appennino settentrionale memorie geografiche, 2, pp. 7-255. bonasera f. (1952) i vulcanell i di fango del preappennino marchigiano riv. geogr. it., lix, 1, pp. 16-26. centamore e. & deiana g. (1986) la geologia delle marche studi geol. camerti, vol. spec., 210 pp. damiani a.v. (1964) studio della salsa di offida (ascoli piceno marche) l’universo, xliv, 3, pp. 473488. eni (1972) acque dolci sotterranee. inventario dei dati raccolti dall’agip durante la ricerca di idrocarburi in italia ed. eni, roma. farabollini p., materazzi m. & scalella g. (2002) mud volcanoes in central-southern marche (italy): proposals for their bounding, enhancing, preservation and protection from extinction in: p. coratza & m. marchetti (eds.) (2002), geomorphological sites: research, assessment and improvement, proceedings of the workshop held in modena, italy, on june 19-22, 2002, legoprint, lavis (tn), pp.110. farabollini p., materazzi m. & scalella g. (2002) ifi g. 4 – d et ai l of m ud v ol ca no es i n th e o ff id a ar ea ( ar ea o f th e fig ur e 3) : th e m ud e m itt ed b et w ee n d ec em b er 1 95 9 an d m ar ch 1 96 0 to ge th er w ith t he r el at iv e m or p ho lo gy ( af te r d am ia ni , 19 64 ). d et ta gl io d ei v ul ca ne lli d i f an go d el l’a re a d i o ff id a (a re a d el la fi gu ra 3 ): em is si on e d i f an gh i a vv en ut a tr a il d ic em b re 1 95 9 ed il m ar zo 1 96 0 e re la tiv a m or fo lo gi a (d a d am ia ni , 1 96 4) . proposal for preservation ... 184 “vulcanelli di fango” della regione marche: proposte di perimetrazione, valorizzazione, conservazione e tutela di aree a rischio di estinzione atti conv. genova, 27-29 giugno 2002, geologia dell’ambiente, in stampa. marinelli o. (1904) i bollitori di san paolo di jesi l’appennino centrale, 1, 9 pp. martinelli g. (1999) mud volcanoes of italy: a review. giorn. geol., ser. 3, vol. 61, pp. 107-113. nanni t. & vivalda p. (1998) le acque salate dell’avanfossa marchigiana: origine, chimismo e caratteri strutturali delle zone di emergenza boll. soc. geol. it., 118, pp. 191-215. nanni t. & zuppi g.m. (1986) acque salate e circolazione profonda in relazione all’assetto strutturale del fronte adriatico e padano dell’appennino mem. soc. geol. it., 35, pp. 979-986. ori g.c., serafini g., visentin c., ricci lucchi f., casnedi r., colalongo m.l. & mosna s. (1991) the plio-pleistocene adriatic foredeep (marche and abruzzo, italy): an integrated approach to surface and subsurface geology 3rd e.a.p.g. conf., florence, 85 pp. sampaolesi s. & farabollini p. (2002) la conservazione e la tutela dei geositi: l’esempio della piramide di terra nel parco nazionale dei monti sibillini (marche centro-meridionali) geologia dell’ambiente, 2, pp. 28-37. scalella g. (1996) geomorfologia e geologia ambientale di un tratto del medio bacino del fiume tenna: correlazioni con il medio bacino del torrente tesi di laurea inedita università di camerino. scalella g. (2000) analisi geomorfologiche in aree interessate da neotettonica: appennino umbromarchigiano e fascia periadriatica tesi di dottorato inedita – università di perugia. various authors (1991) le emergenze geologiche e geomorfologiche delle marche regione marchegiunta regionale, ancona. p. farabollini et al. imp. giaccio & ccaarraatttteerriissttiicchhee ggeeoollooggiiccoo--ggeeoommoorrffoollooggiicchhee eedd eeffffeettttii ddii ssiittoo aa ssaann ggiiuulliiaannoo ddii ppuugglliiaa ((ccbb)) ee iinn aallttrrii aabbiittaattii ccoollppiittii ddaallllaa sseeqquueennzzaa ssiissmmiiccaa ddeellll’’oottttoobbrree--nnoovveemmbbrree 22000022 bbiiaaggiioo ggiiaacccciioo11,, ssaabbaattiinnoo cciiaarrcciiaa22,, ppaaoolloo mmeessssiinnaa11,, aallbbeerrttoo ppiizzzzii33,, mmiicchheellee ssaarroollii44,, aannddrreeaa ssppoossaattoo11,, aauugguussttoo cciittttaaddiinnii11,, vvaalleennttiinnoo ddii ddoonnaattoo22,, ppaaoollaa eessppoossiittoo22 && ffaabbrriizziioo ggaallaaddiinnii11--55 1cnr, istituto di geologia ambientale e geoingegneria, sezione di roma “tor vergata”, via del fosso del cavaliere 100, 00133 roma (giaccio@irtr.rm.cnr.it) 2dipartimento di scienze della terra, università di napoli “federico ii”, largo s. marcellino 10, 80134 napoli (sciarcia@unina.it) 3 dipartimento di scienze della terra università di chieti "g. d'annunzio", campus universitario madonna delle piane, chieti scalo, 66013 chieti (pizzi@unich.it ) 4cnr, istituto di geologia ambientale e geoingegneria, sezione di roma “la sapienza”, piazzale aldo moro 5, 00185, roma (michele.saroli@uniroma1.it) 5ingv, via di vigne murate 605, 00143 roma riassunto: giaccio b. (et al.), caratteristiche geologico-geomorfologiche ed effetti di sito a san giuliano di puglia (cb) e in altri abitati colpiti dalla sequenza sismica dell’ottobre-novembre 2002. it issn 0394-3356, 2004. in seguito ai due eventi di ml 5,4 e 5,3 della sequenza sismica del 31 ottobre-1 novembre 2002, sono state osservate significative disomogeneità nella distribuzione del danno. il caso più eclatante è rappresentato dall’abitato di san giuliano di puglia, caratterizzato da un marcato contrasto fra aree con edifici distrutti ed altre solo lievemente danneggiate in contiguità fra loro. anomalie nella distribuzione del danno sono state riscontrate anche in centri attigui prossimi alle zone epicentrali. la massima intensità mcs di viii-ix grado è stata attribuita a san giuliano di puglia, mentre agli abitati di bonefro e colletorto, siti a qualche chilometro da san giuliano di puglia, sono stati assegnati rispettivamente i gradi di vii e vi-vii mcs. in nessun caso sono stati assegnati i gradi intermedi di vii-viii e viii. queste “anomalie” hanno suggerito che alcuni potenziali fattori locali, quali le caratteristiche geologiche del sottosuolo, i dissesti franosi o le caratteristiche del costruito, abbiano fortemente condizionato l’entità e la distribuzione dei danni. al fine di identificare e definire il ruolo di questi potenziali fattori di amplificazione locale, è stata condotta un’indagine geologica multidisciplinare (stratigrafica, biostratigrafica, geologico-strutturale e geomorfologica) che ha interessato il territorio di san giuliano di puglia e altri centri fra i più colpiti dalla sequenza sismica (ripabottoni, morrone del sannio, pietramontecorvino e castellino del biferno). l’esame dei dati acquisiti, ha evidenziato nel caso di san giuliano di puglia, una relazione diretta tra danneggiamento e caratteristiche geologico-strutturali e litologiche dei terreni di fondazione. negli altri centri esaminati gli effetti di sito risultano generalmente moderati e condizionati da fenomeni franosi preesistenti. abstract: giaccio b. (et al.), geological-geomorphological characteristics and site effects at san giuliano di puglia (molise, southern italy) and other localities struck by the seismic sequence of october-november 2002. it issn 0394-3356, 2004. on october 31 and november 1 2002, the eastern molise region (biferno and fortore rivers) of the southern apennines (southern italy) was struck by two seismic events characterised by magnitude ml 5.4 and 5.3, respectively. although the magnitude is definitely lower than that of the largest apennine seismic events (ml>6), in some villages the earthquake caused significant damage, particularly at san giuliano di puglia. preliminary surveys at the damaged localities revealed strong differences in the damage distribution. in some villages, indeed, we observed the coexistence of areas characterised by significant damage (with partial or total collapse of edifices) with areas affected by little damage. the highest intensity of 8-9 mcs has been assigned to san giuliano di puglia, while intensities of 7 and 6-7 mcs have been attributed to bonefro and colletorto (located close to san giuliano di puglia), respectively. intensities of 7-8 and 8 mcs have in no case been attributed. these anomalies suggested that local effects, e.g. related to peculiar geologic and morphologic conditions or landsliding, may have played an important role in determining the damage distribution. this role may have been amplified by the characteristics and age of the edifices, significantly different throughout a single village. in order to asses the site effects at san giuliano di puglia, ripabottoni, morrone del sannio, pietramontecorvino and castellino del biferno, a multidisciplinary geological investigation (stratigraphy, biostratigraphy, structural geology and geomorphology) was performed. such a multidisciplinary approach has allowed an assessment of the contribution that the single local factor(s) eventually had in determining the damage amplification. the detailed geological studies carried out at san giuliano di puglia permitted the definition of the main stratigraphic and structural features of this area, conditioned by a complicated structural style, with thrusts and folds affecting the toppo capuana and flysch di faeto formations (tortonian and langhian-tortonian, respectively). the comparison of the damage distribution with the structural framework permits the definition of a direct relationship between the maximum damage and the foundation of the buildings in the clayey marls of the toppo capuana formation. in contrast, the edifices founded in the marly limestone of the flysch di faeto formation suffered less severe damage. in the other investigated localities, the site effects seem more moderate. the slight damage amplification is mainly due to the coseismic re-activation of pre-existing landslides. parole chiave: terremoto, effetti di sito, molise. keywords: earthquake, site effects, molise, southern italy. il quaternario italian journal of quaternary sciences 1177(1), 2004, 83-99 84 b. giaccio et al. 11.. iinnttrroodduuzziioonnee a partire dalle prime ore del 31 ottobre 2002 una sequenza sismica ha interessato un settore dell’appennino molisano compreso fra i segmenti della media valle del fiume fortore e del biferno. i due principali eventi del 31 ottobre e 1 novembre sono stati localizzati rispettivamente nei pressi dei comuni di bonefro e ripabottoni (istituto nazionale di geofisica e vulcanologia, 2002) (fig. 1). sebbene la magnitudo di questi eventi (ml 5,4 e 5,3) sia stata decisamente più bassa di quella dei grandi terremoti appenninici, nell'abitato di san giuliano di puglia si sono avute anche perdite umane, mentre danni significativi sono stati riscontrati in alcuni altri abitati. i sopralluoghi a san giuliano di puglia hanno evidenziato una forte disomogeneità della distribuzione del danno, che è apparso concentrato in specifiche aree degli abitati. anomalie nella distribuzione del danno sono state riscontrate anche fra centri attigui. la massima intensità mcs di viii-ix grado è stata attribuita a san giuliano di puglia, mentre agli abitati di bonefro e colletorto, siti a qualche chilometro da san giuliano di puglia, sono stati assegnati rispettivamente valori di vii e vi-vii mcs (fig. 1; galli et al., 2003). questi indizi hanno suggerito che alcuni fattori locali, quali le caratteristiche geologiche dei terreni di fondazione, gli eventuali fenomeni di dissesto franoso e/o le tipologie edilizie, abbiano fortemente condizionato l’entità e la distribuzione dei danni. lo scopo di questo studio è l'identificazione dei fattori locali che hanno potenzialmente condizionato la risposta sismica in san giuliano di puglia e, in via preliminare, anche in altri centri fra i più colpiti dalla sequenza sismica (ripabottoni, morrone del sannio, pietramontecorvino e castellino del biferno). gli aspetti legati alle geometrie e ai caratteri litologici dei terreni di fondazione dell’abitato di san giuliano sono stati valutati attraverso un rilevamento geologico di dettaglio (1:5.000) ed analisi biostratigrafiche che hanno permesso di ricostruire i principali lineamenti della stratigrafia locale nonché la distribuzione e l’assetto strutturale delle formazioni affioranti. negli altri centri esaminati lo studio si è limitato a rilevamenti geologici speditivi che in ogni caso hanno permesso di delineare con maggior dettaglio gli aspetti della geologia locale desunti dalla carta geologica d’italia 1:100.000 e/o dalla cartografia tecnica regionale a più grande scala. pertanto, lo studio dei rapporti tra geologia, fenomeni franosi, strutture del costruito e danneggiamento in questi abitati va inteso come preliminare, non comparabile al quadro di dettaglio ricostruito per s. giuliano. l'analisi fotogeologica condotta sul volo italia 1988-89 (scala nominale 1:70.000) e i controlli di terreno hanno permesso di effettuare uno studio morfologico di dettaglio con particolare attenzione al riconoscimento dei fenomeni franosi in prossimità dei centri abitati. in particolare per i fenomeni franosi è stata consultata la banca dati del progetto avi e quella presente sul sito internet della regione molise. osservazioni dirette sui principali caratteri del costruito (qualità e tipo di muratura altezza ed età degli edifici, modifiche strutturali, ...) integrate con alcuni dati preliminari derivati dai rilievi del servizio sismico nazionale (2002) hanno infine permesso di suddividere gli abitati esaminati in aree statisticamente caratterizzate da tipologie edilizie omogenee. l’esame dei dati acquisiti, in seguito restituiti in elaborati cartografici a grande scala, ha permesso di valutare con buon dettaglio il contributo che ognuno dei summenzionati fattori ha avuto nel determinare l’entità e la distribuzione dei danni in s. giuliano. per gli altri centri indagati, viene invece fornito un quadro provvisorio che consente in ogni caso di avanzare alcune ipotesi preliminari. 22.. llaa sseeqquueennzzaa ssiissmmiiccaa il principale evento della sequenza sismica del terremoto del molise (ml 5,4), localizzato a pochi chilometri a sud-ovest di bonefro, è stato registrato dalle rete sismica nazionale alle 11.32 del 31 ottobre 2002 dopo una serie di lievi scosse (mi 3,5) succedutesi a partire dalle 1.25 dello stesso giorno. dopo numerose repliche di bassa magnitudo è seguito alle 16.08 del 1 novembre una seconda forte scossa (ml 5,3) con epicentro localizzato a circa 5 km ad ovest dell'evento principale (istituto nazionale di geofisica e vulcanologia, 2002). i dati sismologici indicano per entrambi gli eventi una profondità di circa 20 km e meccanismi focali con piani trascorrenti rispettivamente n-s sinistra e e-w destra (istituto nazionale di geofisica e vulcanologia, 2002). la distribuzione delle repliche, con una chiara orientazione in direzione e-w, suggerirebbe che le sorgenti sismogeniche responsabili degli eventi principali della sequenza sismica abbiano un orientamento parallelo. 33.. ddiissttrriibbuuzziioonnee ddeell ddaannnnoo il danno in san giuliano di puglia è stato valutato in viii-ix della scala mcs (galli et al., 2003); questo valore è superiore all'intensità attribuita agli altri centri abitati con il rilievo macrosismico aggiornato al 30 fig. 1 ubicazione degli abitati indagati nel quadro della distribuzione delle intensità mcs. location of the investigated localities in the framework of the mcs intensity distribution. novembre 2002. questi dati evidenziano, in effetti, che a bonefro, castellino del biferno, ripabottoni, santa croce di magliano nella provincia di campobasso e casalnuovo monterotaro nella provincia di foggia è riferibile un livello di danneggiamento compatibile con il grado vii della scala mcs. l'intensità vii rappresenta il livello immediatamente sottostante a quello definito per san giuliano; in pratica non sono presenti abitati cui sia riferibile un valore di intensità intermedio tra il grado viii-ix ed il vii. l'area che inviluppa gli abitati caratterizzati da un danno valutabile con i=vii mcs è mediamente allungata in direzione e-w, tra castellino del biferno e santa croce di magliano, per una lunghezza dell'ordine di 20 km (fig. 1). tale distribuzione del danno sembra compatibile con l'attivazione delle sorgenti sismogeniche con direzione e-w, derivabili dai dati strumentali (istituto nazionale di geofisica e vulcanologia, 2002). gli effetti nella provincia di foggia, in particolare casalnuovo monterotaro (vii) e pietramontecorvino (vi), rappresentano, nel contesto di questa distribuzione del danno, delle anomalie (galli et al., 2003). tali forti risentimenti portano ad un significativo ampliamento verso sud dell'area con danni sensibili. come si vedrà nei capitoli successivi, almeno nel caso di pietramontecorvino il danneggiamento risente di fattori geologici locali responsabili di fenomeni di instabilità di pendii in litologia argillosa. 44.. ccaarraatttteerriissttiicchhee ggeeoollooggiiccoo-ssttrruuttttuurraallii ddeellll’’aarreeaa ccoollppiittaa ddaall ssiissmmaa 44..11.. iinnqquuaaddrraammeennttoo ggeeoollooggiiccoo il territorio colpito dal sisma occupa un settore dell’appennino meridionale al confine esterno dei fronti di accavallamento delle falde dell’unità dauna sui terreni autoctoni dell’avanfossa bradanica e dell’avampaese apulo (patacca et al., 1992). lo stile deformativo corrisponde a quello dei settori esterni dell’appennino meridionale, caratterizzato da estese falde alloctone fortemente traslate e plurideformate, al di sotto delle quali l’avampaese apulo sepolto è raccorciato con una geometria di tipo duplex (es. patacca & scandone, 1989). nell’area molisana, secondo di bucci et al. (1999, cum biblio), lo scollamento basale delle falde alloctone è in genere condizionato dalla presenza di argille varicolori, alla quale sono imputabili lo sviluppo di sottili thrust sheet con estesi flat e presenza di retroscorrimenti. la complessità di tale stile deformativo, evidenziato anche in altre località dell’appennino dauno (cfr. pescatore et al., 1998), unitamente ad una complessiva scarsa presenza di affioramenti, critica nei terreni argillosi, ha reso particolarmente problematica la ricostruzione in dettaglio dell’assetto stratigrafico-strutturale degli abitati indagati. 44..22.. ggeeoollooggiiaa ddii ssaann ggiiuulliiaannoo ddii ppuugglliiaa 4.2.1. stratigrafia il substrato pre-quaternario nell’area di san giuliano di puglia è caratterizzato dalla quasi esclusiva presenza di depositi miocenici calcareo-clastici, marnosi ed argillosi riferibili all’unità dauna (senatore, 1988; santo & senatore, 1988; russo & senatore, 1989); soltanto in maniera nettamente subordinata, sono rinvenu85caratteristiche geologico-geomorfologiche ... te isolate placche di sedimenti sabbioso-pelitici pliocenici della formazione del tona (servizio geologico d’italia, 1969). uunniittàà ddaauunnaa la successione dell'unità dauna (langhianomessiniano inf.), affiora con buona continuità nell'area tipo di monte sidone, a nw di castelluccio valmaggiore (fg) ed è costituita dal basso verso l'alto dalle seguenti formazioni: calcareniti, argille e marne di monte sidone (non affiorante nell’area in esame), flysch di faeto e marne argillose del toppo capuana. nel settore orientale dell’area rilevata è stata studiata una sezione stratigrafica, al passaggio dal membro marnoso-argilloso-calcareo del f. di faeto alle marne argillose del toppo capuana; in altre zone del territorio di s. giuliano sono stati prelevati campioni per controlli ad altezze stratigrafiche differenti. flysch di faeto la formazione, istituita da crostella & vezzani (1964), e discussa in lavori successivi (di nocera & torre, 1987; senatore, 1988; santo & senatore, 1988; russo & senatore, 1989; patacca et al., 1990; dazzaro et al., 1992; patacca et al., 1992; sgrosso, 1998; basso et al., 2002), nell’area indagata, è stata distinta su base litologica in due membri, affioranti con trend sedimentario fining-up, costituiti da depositi torbiditici calcareo-clastici, da marne ed argille. il membro calcareo marnoso, in posizione stratigrafica più bassa, è organizzato in alternanze di calciruditi, brecciole e calcareniti bioclastiche (litotamni, briozoi, ecc.) bianche, calcilutiti e marne biancastre, con intercalazioni di argille marnose grigio-azzurre; abbondanti sono i foraminiferi planctonici. buone esposizioni di intervalli di questo membro si hanno lungo il versante meridionale dell’abitato (figg. 2 e 3b) ed in numerosi affioramenti poco al di fuori dell’area esaminata. lo spessore complessivo in quest’area è dell’ordine dei 200 m (fig. 4), con un limite inferiore non riconoscibile a causa della scarsità di affioramenti. i campioni di tale membro sono caratterizzati da associazioni a nannoplancton calcareo e foraminiferi plantonici in cattivo stato di conservazione, tale da rendere talvolta difficoltoso il riconoscimento delle specie. nelle nannoflore si segnala la presenza di discoaster calcaris, mentre nelle associazioni a foraminiferi planctonici si segnala la presenza di individui di neogloboquadrina acostaensis di ridotte dimensioni. nel complesso le associazioni planctoniche indicano un’età non più antica del serravalliano superiore (sottozona a neogloboquadrina continuosa di foresi et al., 1998; biozona cn5b di okada & bukry, 1980). verso l’alto si passa gradualmente al membro marnoso argilloso calcareo (fig. 4) che è costituito da alternanze di calcari marnosi, marne, e subordinate calcilutiti, calcareniti e brecciole bioclastiche e marne argillose biancastre ed argille verdine. tale membro affiora diffusamente ai margini di san giuliano e negli immediati dintorni (fig. 2), in genere deformato secondo pieghe complesse o a stretto raggio di curvatura (fig. 3c), con uno spessore complessivo ricostruibile di ca. 150 m (fig. 4). i numerosi campioni di questo membro presentano associazioni planctoniche in buono stato di conser86 fig. 2 carta geologica e sezioni schematiche dell’area circostante l’abitato di san giuliano di puglia. geological map and schematic sections of the san giuliano di puglia village and surrounding areas. b. giaccio et al. 87 vazione. le nannoflore presentano associazioni ricche e ben diversificate con discoaster surculus, discoaster quinqueramus, calcidiscus leptoporus e calcidiscus macintyrei tra gli altri. nelle associazioni a foraminiferi plantonici si segnala la presenza di globigerinoides obliquus obliquus, globorotalia ventriosa, orbulina universa, neogloboquadrina acostaensis. tali associazioni planctoniche indicano un’età, in particolare per la presenza di d. surculus e d. quinqueramus, non più antica del tortoniano superiore (biozona a globigerinoides extremus di foresi et al., 1998; biozona cn9a di okada e bukry, 1980). nella parte alta del membro si rinvengono intercalazioni decimetriche e pluridecimetriche di arenarie torbiditiche giallastre, a grana media e dalla caratteristica stratificazione “a cogoli”. queste sono esposte in corrispondenza dell’anticlinale a sw dell’abitato ed in località casino di stefano (fig. 2). lungo la sp 40 adriatica, tra s. giuliano e colletorto, in prossimità del ponte sul vallone grande, è possibile inoltre osservare un intervallo di circa 10 metri di depositi sia marnoso-calcarei sia arenitici, intimamente associati e con assemblaggio caotico. questo affioramento rappresenta probabilmente uno dei frequenti fenomeni franosi intraformazionali segnalati in letteratura (selli, 1962; senatore, 1988; dazzaro et al., 1992) a diverse altezze stratigrafiche: nel nostro caso la sua collocazione risulta piuttosto dubbia ma sembra evidente che essa sia da riferire all' ambito fig. 3 (a) visione panoramica della zona occidentale dell’abitato di san giuliano di puglia; (b) dettaglio del membro calcareo marnoso del flysch di faeto affiorante a ovest dell’abitato; (c) dettaglio del membro marnoso argilloso calcareo del flysch di faeto affiorante a sud dell’abitato; (d) visione panoramica della zona meridionale dell’abitato di san giuliano di puglia con indicazione dei rapporti strutturali fra le formazioni del flysch di faeto (ff’= membro calcareo marnoso; ff"=membro marnoso argilloso calcareo) e marne argillose del toppo capuana (atc). (a) panoramic view of the western zone of san giuliano di puglia; (b) limestone marly member of the flysch di faeto formation outcropping in the western sector of the village; (c) marly clayey limestone member of the flysch di faeto formation outcropping in the southern sector of the village; (d) panoramic view of the southern zone of the san giuliano di puglia village, the structural relationship between flysch di faeto (ff’= limestone marly member; ff"=marly clayey limestone member) and marne argillose del toppo capuana (atc) formations is showed. caratteristiche geologico-geomorfologiche ... 88 (o ai margini) del membro marnoso argilloso calcareo del flysch di faeto. gli strati calcareo-clastici del flysch di faeto hanno spessore variabile, da diversi dm ad alcuni mm, e sono più spessi nel membro inferiore (calcareo marnoso) dove la granulometria è più grossolana e dove nella maggior parte dei casi è osservabile la sequenza completa di bouma (1962). talvolta (soprattutto nel membro superiore) le torbiditi debuttano con calcareniti prive dell’intervallo basale gradato (sequenza tb-e) e, verso l'alto, passano gradualmente a calcilutiti e marne calcaree ricche in foraminiferi planctonici, spesso interessate da intensa bioturbazione. il limite tra i due membri, comunque, può essere fissato in corrispondenza della zona di transizione tra i termini basali a dominante calcarea, solitamente in strati spessi (30-50 cm), e quelli sommitali, prevalentemente marnosi ed in strati da sottili a molto sottili (1-10 cm); strati di medio spessore (10-30 cm) sono presenti in entrambi i membri. va segnalato che le microfaune a foraminiferi planctonici del flysch di faeto, in precedenza attribuito all'elveziano-tortoniano inferiore (crostella & vezzani, 1964), indicano, in un’area più a sud, un’età compresa tra il langhiano inferiore ed il tortoniano inferiore (russo & senatore, 1989). secondo patacca et al. (1992) depositi della parte più alta della formazione di faeto hanno rivelato un'età prossima al l imite tortoniano superiore-messiniano per la presenza di a. primus, d. blackstockae e d. triradiatus associati a gb. suterae. marne argillose del toppo capuana verso l'alto il membro marnoso argilloso calcareo del flysch di faeto passa gradualmente alle marne argillose del toppo capuana (crostella & vezzani, 1964). tale formazione è caratterizzata da argille verdi e da marne argillose di colore grigio-azzurro con stratificazione orizzontale o indistinta, con rare intercalazioni di sottili strati calcarenitici torbiditici che ne interrompono occasionalmente la continuità. fig. 4 sezioni s t r a t i g r a f i c h e schematiche rappresentative dell’area investigata. schematic stratigraphic sections of the investigated areas. b. giaccio et al. tali depositi si rinvengono, in modo diffuso, in corrispondenza della parte mediana dell’abitato di san giuliano di puglia e lungo i versanti occidentale ed orientale: ad ovest la presenza delle argille viene interrotta da una fascia di flysch di faeto, in posizione culminante lungo l'asse di un'anticlinale (loc. palazzetto dello sport com), mentre ad est questi depositi sono mobilizzati da fenomeni gravitativi. una sezione stratigrafica ben esposta è visibile da c. cirinalli (presso loc. piano) al fondovalle del vallone, dove è possibile osservare il passaggio graduale dai termini più alti del flysch di faeto. i campioni di questo membro presentano associazioni planctoniche analoghe a quelle del membro marnoso argilloso calcareo del flysch di faeto, e quindi indicano un’età non più antica del tortoniano superiore. lo spessore stimato è di 100-150 m (fig. 4c). nel settore dauno, poco più a sud, alle marne viene attribuita un'età compresa tra il tortoniano inferiore e il tortoniano medio-superiore (russo & senatore, 1989). nelle aree ubicate a nord di monte sidone, al confine molisano abruzzese, la formazione delle marne argillose del toppo capuana ha un'età che raggiunge il messiniano (ciaranfi et al., 1981). secondo patacca et al. (1990; 1992) le marne di toppo capuana nella località tipo costituiscono in realtà la parte altissima di una successione messiniana di bacino piggy-back discordante sulle falde sannitiche e con queste tettonicamente trasportata sulle falde molisane. ffoorrmmaazziioonnee ddeell ttoonnaa tale formazione di età messiniano-infrapliocenica, istituita dai rilevatori del foglio s. severo (boni et al., 1969; servizio geologico d’italia, 1969), viene qui trattata prevalentemente per la sua parte pliocenica, che costituisce la quasi totalità degli affioramenti osservati. si tratta di molasse gialle e giallo-brunastre, in grossi banchi, con livelli fortemente cementati, diffusa malacofauna (panopaea, pecten, solen, ecc.) e rare intercalazioni di argille verdastre. tale formazione giace, trasgressivamente e con discordanza angolare talora notevole, sui terreni dell'unità dauna. la trasgressione è ben esposta in più punti e particolarmente nei dintorni di san giuliano di puglia e di colletorto (servizio geologico d’italia, 1969). gli affioramenti migliori sono esposti nei pressi di loc. piano, nella parte alta del versante sul vallone grande (in prossimità del campo sportivo) (fig. 2) e sul pendio meridionale del rilievo posto a sud di san giuliano. anche presso mass. vallone (piano quadrato), si osservano le sabbie di trasgressione al di sopra delle formazioni dell'unità dauna, fortemente inclinate a sw (boni et al., 1969). la facies argillosa pliocenica della formazione del tona (argille siltose grigio-azzurro) è mancante nell'area esaminata. essa è, però, molto simile alle marne di toppo capuana; perciò quando i due termini sono a diretto contatto, risulta difficoltoso tracciare un limite tra loro con il solo criterio litologico. gli spessori rinvenuti in affioramento non superano la decina di metri. ddeeppoossiittii qquuaatteerrnnaarrii prescindendo dai sedimenti direttamente connessi ai fenomeni franosi di cui si riferisce oltre, le coperture quaternarie si riducono a lembi di alcuni metri di spessore di depositi di versante localizzati soprattutto lungo il fianco occidentale della dorsale di san giuliano. si tratta di ghiaie eterometriche a luoghi ben stratificate ad elementi subangolosi derivanti dallo smantellamento del substrato calcareo marnoso del flysch di faeto. su queste ghiaie poggiano sedimenti colluviali a matrice bruno-grigiastra contenenti abbondanti frammenti ceramici di età medioevale-rinascimentale. depositi colluviali simili e coperture antropogeniche recenti di spessore metrico sono state osservate fino al limite del centro storico e segnalate in sondaggi nel sottosuolo dell’intero abitato (naso et al., 2002) 4.2.2. assetto strutturale nel settore interessato dal rilevamento geologico e nelle aree limitrofe, l’unità dauna, rappresentata in larga misura dal flysch di faeto, risulta in genere deformata secondo pieghe ad andamento assiale nnw-sse, vergenti verso l’avampaese apulo ed aventi fianchi orientali da verticali a rovesciati. tali geometrie, unitamente alla limitata lunghezza d’onda delle pieghe suggeriscono la presenza di un livello di scollamento superficiale, probabilmente costituito da argille varicolori, litologie ampiamente rappresentate in questo settore della catena. le aree che offrono le migliori esposizioni e che hanno consentito di definire con buona approssimazione i principali lineamenti strutturali, corrispondono al versante occidentale del rilievo su cui sorge l’abitato di san giuliano e il fianco occidentale della dorsale allungata in senso appenninico immediatamente ad est di san giuliano (figg. 2 e 3a). l’ampio settore vallivo che separa i due rilievi, inciso nei sedimenti argillosi della fm. di toppo capuana e interessato da diffusi fenomeni franosi, ha restituito scarsissimi affioramenti. lungo il versante occidentale dell’abitato una serie di limitati ma pressoché continui affioramenti del membro marnoso – argilloso – calcareo del flysch di faeto, hanno permesso di riconoscere una struttura anticlinalica con asse orientato in senso appenninico (fig. 2). questa struttura è ben visibile in affioramento in corrispondenza di un taglio stradale a sud dell’abitato dove presenta il suo fianco orientale, da verticale a rovesciato, accavallato verso est sulle argille del toppo capuana (figg. 3c e 3d). sempre lungo il fianco occidentale del rilievo san giuliano, all’altezza del limite del nucleo storico, si distingue un settore caratterizzato da un’improvvisa modificazione che interessa sia la giacitura che la porzione stratigrafica del flysch di faeto affiorante che passa bruscamente dal membro marnoso – argilloso – calcareo al membro calcareo marnoso. tali elementi sono riconducibili ad una scaglia tettonica superiore verosimilmente accavallata sull’anticlinale (figg. 2 e 3d). in particolare, le relazioni geometriche tra queste due unità suggeriscono una messa in posto in fuori sequenza della scaglia tettonica superiore in quanto dislocava l’anticlinale già presente nel suo footwall (fig. 2), inoltre, la generale immersione degli strati verso nw dell’unità superiore potrebbe indicarne una strutturazione non coassiale con le pieghe ad andamento nnw-sse presenti nel blocco di letto. lungo la dorsale opposta che fiancheggia ad est il vallone vailato, affiorano diffusamente i terreni del membro marnoso – argilloso – calcareo del flysch di faeto con giaciture costantemente a reggipoggio o prossime alla verticale (fig. 2). un simile assetto delle 89caratteristiche geologico-geomorfologiche ... giaciture è stato osservato anche nelle rare esposizioni delle argille del toppo capuana che in questo settore affiorano al disotto del flysch di faeto. negli intervalli più grossolani di questa porzione del flysch di faeto sono state inoltre osservate sequenze di bouma a polarità invertita. questi elementi indicano che la successione dell’unità dauna risulta rovesciata e che l’intero settore costituisca un fianco di una sinclinale a vergenza occidentale con asse orientato nnw-sse (fig. 2), verosimilmente collegabile ad un motivo di retroscorrimento posto più ad oriente. l’analisi mesostrutturale ha inoltre evidenziato la presenza di minori motivi di taglio con cinematica normale orientati mediamente nnw-sse caratterizzati da rigetti generalmente inferiori al metro. in conclusione, l’assetto strutturale è caratterizzato da una serie di pieghe da verticali a rovesciate associate probabilmente agli scollamenti ubicati nelle litologie meno competenti delle falde alloctone, da cui si diramano rampe di sovrascorrimento che si propagano nei livelli calcareo-marnosi più competenti del flysch di faeto. le geometrie di tali strutture, nel complesso, definiscono un trend deformativo a principale vergenza nordorientale compatibile con l’assetto tettonico-strutturale tipico dei settori esterni della catena dell’appenino meridionale, complicato tuttavia da motivi di fuori sequenza, retroscorrimenti e deformazioni non-coassiali nei diversi thrust-sheet. per quanto riguarda l’aspetto sismotettonico dell’area, è possibile escludere un ruolo sismogenico connesso all’attività di tali sovrascorrimenti che, dai dati di letteratura esistenti, risultano chiaramente sigillati più ad est dai depositi silicoclastici discordanti del pliocene superiore-pleistocene inferiore (es. patacca et al., 1992). è probabile, invece, che motivi trascorrenti o transtensivi siano all’origine della sismicità dell’area come risulta anche dalla soluzione dei meccanismi focali (istituto nazionale di geofisica e vulcanologia, 2002) che evidenziano piani nodali e-w destro e n-s sinistro. in particolare, la zona epicentrale ricadrebbe sul prolungamento occidentale della faglia di mattinata, la cui attività recente trascorrente destra è stata descritta da vari autori (es., finetti, 1982; guerricchio & wasowski, 1988; piccardi, 1998; chilovi et al., 2000). in questa ipotesi, la struttura sismogenica responsabile del terremoto potrebbe essere confinata nel basamento o nella sovrastante piattaforma apula e non ancora propagatasi in superficie sia a causa della presenza del livello di scollamento “duttile”, sia soprattutto per la bassa magnitudo che non raggiungerebbe la soglia di m>6-6.5 necessaria per sviluppare fagliazione fino alla superficie (wells & coppersmith, 1994). 44..33.. aallttrrii cceennttrrii iinnddaaggaattii indagini geolitologiche preliminari sono state effettuate in altri centri danneggiati dal sisma; in particolare sono state analizzate le aree degli abitati di morrone del sannio, ripabottoni, castell ino del biferno e pietramontecorvino. la geolitologia di questi abitati è schematicamente rappresentata in fig. 5. tali schemi sono stati ricostruiti sulla base di rilievi di campagna speditivi integrati dall’analisi fotogeologica e dallo studio delle stratigrafie dei sondaggi e delle cartografie geologiche comunali esistenti e messe a disposizione dei singoli comuni interessati. sono stati distinti e raggruppati i seguenti terreni con caratteristiche litologiche paragonabili. argille ed argilliti varicolori anche se coinvolge direttamente solo gli abitati di castellino del biferno e ripabottoni (fig. 5), questa è fra le litologie più frequenti delle aree indagate. si tratta di argille ed argilliti con subordinati livelli di marne argillose variamente colorate con struttura scagliosa e con giacitura caotica, che presentano caratteristiche meccaniche generalmente da scadenti a molto scadenti. queste costituiscono il substrato principale dell’area e caratterizzano vistosamente il paesaggio con evidenti forme di forte erosione e con frequenti fenomeni gravitativi trattati in dettaglio nel capitolo successivo. sabbie e sabbie limose si tratta di termini prevalentemente sabbiosi e sabbioso-limosi con intercalazioni marnose che presentano caratteristiche meccaniche variabili tra discrete e scadenti; tali terreni sono generalmente attribuiti alla parte basale del flysch di san bartolomeo o localmente alle formazioni sabbioso-pelitiche plioceniche. calcari, marne e arenarie rappresentano i termini litologici più coesivi costituiti da corpi di calcare, calcare marnoso, arenarie e localmente da arenarie quarzose. lembi di tali litotipi costituiscono frequentemente l’ossatura delle strutture morfologiche principali su cui sono ubicati i centri più antichi degli insediamenti in esame (fig. 5). sedimenti clastici incoerenti comprendono i sedimenti di natura clastica che costituiscono le alluvioni di fondovalle, le coperture detritiche di versante e i colluviali. in figura 5 non sono stati distinte le coperture antropogeniche localmente segnalate nei sondaggi ma generalmente non affioranti e non cartografabili. 55.. aasssseettttoo ggeeoommoorrffoollooggiiccoo ee ffeennoommeennii ffrraannoossii le aree analizzate risultano caratterizzate da settori più rilevati, costituiti da litotipi calcareo e calcareomarnosi competenti, alternati a rilievi con sommità arrotondate e/o subpianeggianti, interrotte da depressioni vallive che evidenziano la presenza di litotipi prevalentemente argillosi. un esempio di tale assetto geomorfologico è rappresentato dalla dorsale di san giuliano delimitata da ampi valloni. le aree di raccordo morfologico sono il più delle volte costituite da coltri eluviali e colluviali miste a materiale rimaneggiato proveniente da aree in frana. la morfologia delle aree analizzate è, in effetti, fortemente condizionata dallo sviluppo di estesi fenomeni franosi che rappresentano il principale fattore di modellamento del rilievo. augelli et al. (2001) per aree limitrofe (bacino del trigno, molise) segnalano come la morfodinamica recente ed attiva appaia nettamente dominata da fenomeni di instabilità gravitativa, sia superficiali che profondi. l’analisi fotogeologica è stata pertanto finalizzata soprattutto all’individuazione e alla classificazione delle frane. per la redazione della legenda (fig. 6) si è fatto 90 b. giaccio et al. riferimento a bosi et al. (1985), carrara et al. (1987a; 1987b) e alla “legenda della carta geomorfologia d’italia” (1994) a cui sono state apportate alcune modifiche in relazione alla finalità del lavoro. la legenda è stata quindi sviluppata tenendo conto del tipo di fenomeno e del suo stato di attività, intendendo attivi quei fenomeni conseguenti alle condizioni morfologiche e climatiche al momento presenti nell’area esaminata (varnes, 1978). caratteristica comune a tutti gli abitati indagati, è la presenza di un settore più rilevato, costituito da materiali più competenti, ai cui margini si sviluppano estesi movimenti gravitativi su litologie prevalentemente argillose (fig. 6). tra questi fa eccezione l’abitato di pietramontecorvino dove si osserva la presenza di blande morfologie e la mancanza di netti stacchi morfologici al passaggio tra litotipi più competenti calcareo-marnosi e litotipi argillosi. per tutte le aree analizzate, lo sviluppo dei settori in frana assume una caratteristica forma radiale-centrifuga, con tipologie di dissesti, morfologie ed evoluzioni che si ripetono in modo quasi costante. partendo dai limiti delle aree urbanizzate, caratterizzate da litotipi più competenti, è possibile riconoscere fenomeni di crollo con nette rotture di pendio. sono essenzialmente i materiali lapidei, incoerenti o semicoerenti, che possono distaccarsi improvvisamente dai versanti e frantumarsi durante il movimento. questi fenomeni si verificano in prossimità dei margini delle aree urbanizzate interessati da preesistenti discontinuità strutturali lungo le quali avvengono i distacchi, come nel settore sud-occidentale di san giuliano, morrone del sannio e a nw di ripabottoni (fig. 6). proprio in prossimità dei margini delle aree urbanizzate, al passaggio da litotipi più competenti a litotipi meno competenti, si sviluppano estesi fenomeni di frana di tipo complesso, caratterizzati al loro interno da frane minori di tipo traslativo e/o rotazionale che evolvono nella parte distale in colate. tale tipo di evoluzione è osservabile in particolare ad est di san giuliano, a est e sud di castellino del biferno, a sw e nw di morrone del sannio a se di ripabottoni (fig. 6). nell’area in studio questi fenomeni interessano superfici molto estese, anche interi versanti, che presentano ondulazioni, rigonfiamenti, depressioni a conca e piccole scarpate. nei casi di fenomeni più complessi, in cui siano state riconosciute forme riconducibili a deformazioni gravitative profonde (sensu chighira, 1992; sorriso valvo, 1995; onida, 2002), l’area coinvolta è stata circoscritta con opportuna simbologia lasciando aperta la parte inferiore come nel settore nord di castellino del biferno e nel settore nw di morrone del sannio (fig. 6). numerose infine sono le aree in cui sono stati riconosciuti fenomeni di dissesto superficiali. si tratta di movimenti lenti e discontinui che interessano versanti caratterizzanti da pendenze anche inferiori a 5°. essi sono stati riconosciuti, nella maggior parte dei casi, per il formarsi di colate, lobi, terrazzette e increspature del 91 fig. 5 carte geolitologiche schematiche delle altre località investigate. legenda: 1) sedimenti clastici incoerenti; 2) argille ed argilliti varicolori; 3) sabbie e sabbie-limose; 4) calcari, marne e arenarie. schematic geo-lithological maps of the other investigated localities. legend: 1) clastic loose sediments; 2) clay and shale; 3) sand and silty sand; 4) limestone, marl and sandstone. caratteristiche geologico-geomorfologiche ... 92 fig. 6 dissesti dei centri abitati interessati dal terremoto del 31-10-2002 e 01-11-2002. slope instability in the localities struck by the earthquake occurred on oct. 31, 2002, nov. 1, 2002. b. giaccio et al. terreno; insieme al materiale fine si spostano gli elementi grossolani presenti nel mantello detritico superficiale. i materiali coinvolti sono per lo più di natura argillosa, sui quali le piogge e l’acqua di imbibizione hanno un ruolo determinante per l’innesco del processo. in particolare, le aree circostanti il centro abitato di pietramontecorvino sono caratterizzate esclusivamente da fenomeni superficiali di non rilevante importanza, riconducibili prevalentemente a deformazioni lente superficiali. in tali settori infatti non sono state riconosciute altre tipologie di frane (fig. 6). i fenomeni di dissesto che interessano i settori interni del costruito negli agglomerati urbani non sono stati individuati da foto aree ma mediante indagini conoscitive e raccolte di materiale presso i comuni. 66.. ssiittuuaazziioonnee uurrbbaanniissttiiccaa ee ttiippoollooggiiee ccoossttrruuttttiivvee nei giorni successivi agli eventi sismici, negli abitati di san giuliano di puglia, ripabottoni, morrone del sannio, pietramontecorvino e castellino del biferno, oltre ad osservazioni sull’assetto urbanistico, sono stati eseguiti rilievi sugli edifici al fine di comprenderne le caratteristiche costruttive (tipo delle murature, altezza degli edifici, presenza di sopraelevazioni successive alla edificazione, ecc.) e di definire l’entità dei danni da essi subiti. a causa delle difficoltà incontrate durante queste operazioni (ad esempio l’impossibilità di accedere all’interno di molte costruzioni e in alcune parti dei centri storici danneggiati), i dati acquisiti sono stati confrontati ed integrati con quelli delle amministrazioni locali (che hanno provveduto a fornire anche le informazioni relative all’età dei fabbricati) al fine di avere un quadro il più possibile omogeneo e confrontabile della distribuzione dei danni nei vari comuni. in base a queste informazioni gli abitati sono stati suddivisi in tre zone a tipologie edilizie mediamente uniformi, caratterizzate dalla presenza di edifici risalenti al medesimo periodo di costruzione. zona a. classe di vulnerabilità a, raramente b (msk-76; braga et al., 1985). in questa zona sono stati inseriti gli antichi centri storici e gli insediamenti costruiti sino al xix secolo. le abitazioni raramente superano i due piani di altezza e sono addossate le une alle altre o sono separate da strade strette e/o tortuose. le murature, generalmente realizzate con struttura a sacco, utilizzano pietrame legato da malte di qualità scadente. il pietrame solo in qualche caso presenta elementi squadrati, concentrati in prossimità degli spigoli e sulla parte esterna dalle murature. non di rado il primo piano è caratterizzato da volte a botte, a crociera o miste ed i solai e le coperture sono spesso in legno. alcune case oggetto di ristrutturazione presentano opere di rinforzo come contrafforti in pietrame, tiranti metallici e putrelle nei solai. zona b. classe di vulnerabilità b, a volte a e raramente c (msk-76; braga et al., 1985). in questa zona sono stati inseriti gli insediamenti relativamente recenti (dal 1900 sino al 1950 circa), caratterizzati da una notevole disomogeneità edilizia sia per quanto riguarda le tecniche costruttive che per i materiali utilizzati. gli edifici sono costituiti al massimo da due o tre piani e sono realizzati in muratura con pietrame, costituito da elementi non squadrati e di dimensioni diverse tra loro, legato da malte di solito molto scadenti. raramente sono state realizzate murature di tufo con elementi squadrati o di mattoni pieni mentre, a volte, pietre lavorate e squadrate sono state utilizzate per i rivestimenti esterni delle facciate. molto spesso i piani superiori degli edifici sono stati realizzati in più fasi costruttive e con tecniche artigianali. e’ stato osservato di frequente come i piani superiori siano stati costruiti con mattoni forati mentre i solai sono realizzati con materiali laterocementizi o in legno o con putrelle di acciaio. solo raramente sono state osservate opere di rinforzo o contenimento o la presenza di tiranti metallici. zona c. classe di vulnerabilità c (msk-76; braga et al., 1985). in questa zona sono state comprese le nuove aree residenziali costruite posteriormente al 1950. essa si estende generalmente all’esterno delle due zone precedentemente descritte ed è caratterizzata da edifici costruiti con tecniche moderne, quasi sempre con telaio in cemento armato e pianta di forma regolare. l’altezza delle costruzioni è molto variabile e va da un piano o due, tipica delle villette residenziali, fino a tre o quattro piani per gli edifici più alti. le tamponature e le tramezzature sono generalmente realizzate con mattoni forati. 77.. ddiissttrriibbuuzziioonnee ddeeii ddaannnnii ee lloorroo rreellaazziioonnee ccoonn ii ccaarraatttteerrii ggeeoolliittoollooggiiccii ddeeii tteerrrreennii ddii ffoonnddaazziioonnee,, llee ttiippoollooggiiee ccoossttrruuttttiivvee ee ii ffeennoommeennii ffrraannoossii i rilievi dei danni subiti dagli edifici durante la crisi sismica dell’autunno 2002 nonché le informazioni reperite presso le amministrazioni locali hanno permesso di suddividere i centri abitati in zone a diverso danneggiamento. il criterio seguito per individuare queste zone è stato quello di incrociare i dati sull’agibilità degli edifici, forniti dai comuni, con quelli derivanti dai rilievi da noi eseguiti (es. messina e sposato, 1985). per la quantificazione del danno sono stati utilizzati i sei livelli di danno (tab. 1) della scala msk-76 (medvedev, 1977). 93 tab. 1 definizione dei livelli di danno secondo la scala msk76 (medvedev, 1977). livello del danno descrizione 0 nessun danno 1 danno lieve: fessure sottili e caduta di piccole parti dell’intonaco 2 danno medio: piccole fessure nelle pareti, caduta di porzioni consistenti di intonaco, fessure nei camini parte dei quali cadono 3 danno forte: formazione di ampie fessure nei muri, caduta dei camini 4 distruzione: distacchi tra le pareti, possibile collasso di porzioni di edifici, parti di edificio separate si sconnettono, collasso di pareti interne 5 danno totale: collasso totale dell’edificio caratteristiche geologico-geomorfologiche ... zona 1 (danno elevato) 0-30 % di edifici con livello di danno compreso tra 0 e 1 40-60 % di edifici con livello di danno compreso tra 2 e 3 20-40 % di edifici con livello di danno compreso tra 4 e 5 zona 2 (danno moderato) 30-60 % di edifici con livello di danno compreso tra 0 e 1 40-60 % di edifici con livello di danno compreso tra 2 e 3 1-20 % di edifici con livello di danno compreso tra 4 e 5 zona 3 (danno lieve) >60 % di edifici con livello di danno compreso tra 0 e 1 <40 % di edifici con livello di danno compreso tra 2 e 3 0 % di edifici con livello di danno compreso tra 4 e 5 77..11.. ssaann ggiiuulliiaannoo ddii ppuugglliiaa l’abitato di san giuliano di puglia è caratterizzato dalla presenza di tutte le tipologie costruttive descritte al punto 6. la distribuzione dei danni e le aree con diversa tipologia edilizia sono schematizzate in figura 7. nella zona a è compreso il centro storico più antico, che risale circa all’xi secolo, e la zona relativa alle espansioni del xiv, xvii e xix secolo. questo insieme occupa la parte più meridionale del paese e corrisponde al nucleo abitativo che comprende la vecchia chiesa in una area leggermente rilevata rispetto al resto del paese. sono presenti scarsi fenomeni franosi, classificati come crollo, che non sembrano creare allo stato attuale particolari problemi di stabilità, innescati dall’azione di richiamo delle incisioni sottostanti e da fenomeni di erosione differenziale sul versante meridionale. nel settore più meridionale della zona a, compreso nelle mura della parte più antica del centro storico, nonostante molte abitazioni non fossero normalmente utilizzate e presentassero importanti carenze di manutenzione, sono stati osservati solo danni modesti. nella parte settentrionale, in prossimità della zona b, i danni agli edifici sono più significativi con fenomeni di distruzione parziale o totale. al margine orientale di questa zona sono presenti estesi movimenti franosi complessi che evolvono in scivolamenti e in localizzati fenomeni di colamento. a questa situazione fa eccezione il settore occidentale dove sono stati riscontrati danni abbastanza lievi e più del 70% delle case sono risultate agibili, sebbene il versante risulti caratterizzato dalla presenza di una frana per scivolamento. 94 fig. 7 quadro urbanistico (a) e distribuzione del danno in relazione alla litologia (b) a san giuliano di puglia (si veda teso per dettagli). urbanistic framework (a) and damage distribution related to the lithology (b) at san giuliano di puglia (see text for details). b. giaccio et al. la zona b si estende, con direzione allungata circa ns, tra il centro storico e la località dove è situato il serbatoio dell’acquedotto. al suo interno sono presenti alcune costruzioni realizzate o ristrutturate di recente con struttura in cemento armato. e’ la zona che, insieme al settore settentrionale della zona a, ha subito i danni più gravi con diffusi crolli sia totali che parziali (livello di danno da 3 e 5) e con la quasi totalità delle abitazioni dichiarate inagibili. sono state notati danni importanti anche ad un edificio in cemento armato. questo settore corrisponde all’area di separazione tra i fenomeni franosi a sviluppo ed estensione nnw-sse e nne-ssw che caratterizzano entrambi i fianchi vallivi che delimitano l’abitato di san giuliano. la zona c si estende nella zona settentrionale esternamente al nucleo del paese ed è rappresentata da edifici sparsi sul territorio. non ha subito danni significativi e quasi tutti gli edifici sono stati dichiarati agibili. dall’analisi dei dati relativi alla distribuzione dei danni si può notare come il settore centrale del paese abbia subito i danni maggiori a parità di tipologie edilizie e nonostante sia la zona con le costruzioni relativamente più recenti. in questa area hanno subito danni anche edifici in cemento armato. le costruzioni della parte più antica del centro storico, edificate nella zona più rilevata del paese, hanno invece subito danni relativamente minori mentre le abitazioni della zona c non hanno riportato danni significativi (galli et al., 2003). se si confrontano queste informazioni con la carta geologica di figura 2 e le aree interessate da frane di fig. 6 si può notare come esista una stretta relazione tra la distribuzione dei danni e le litologie affioranti (fig. 7b). le abitazioni della zona a poggianti sul flysch di faeto hanno riportato danni inferiori rispetto alle costruzioni con le stesse caratteristiche poggianti sulla formazione del toppo capuana e sui colluvi e terreni di riporto. lo stesso fenomeno è osservabile sulle abitazioni della zona b (fig. 7) che, sebbene mediamente presentano qualità costruttive migliori, hanno subito danni molto più gravi di quelli subiti dalle abitazioni della zona a. le costruzioni più recenti della zona c non hanno subito particolari danni indipendentemente dai terreni su cui sono state edificate. 77..22.. rriippaabboottttoonnii l’abitato di ripabottoni, ad esclusione di pochissime costruzioni realizzate di recente e con struttura in cemento armato, è caratterizzato dalla uniformità delle tipologie edilizie, tutte riferibili alla zona a descritta al punto 6. la distribuzione dei danni e le aree con diversa tipologia edilizia sono schematizzate in figura 8. tutto l’abitato risale al xviii-xix secolo tranne una piccola zona più antica (xvii-xviii secolo), ubicata nel settore nordoccidentale. nella parte più antica molte abitazioni non erano normalmente utilizzate e presentano importanti carenze di manutenzione. questa situazione riveste una particolare importanza poiché proprio in quest’area si sono verificati i danni più significativi. un’altra zona dove si sono verificati danni importanti è quella nordorientale dove però è da tempo presente un fenomeno franoso (ufficio tecnico del comune di ripabottoni, com. pers.) che durante la scossa sismica ha avuto una piccola ripresa. dall’esame della situazione geologica illustrata in figura 5 non sembra ipotizzabile alcuna relazione tra le litologie affioranti e i danneggiamenti. sembra invece che la pre-esistenza di fenomeni franosi a contorno possa in questo caso aver influito sulla distribuzione del danno anche con la riattivazione della frana che interessa il costruito all’interno dell’agglomerato urbano nel settore nord. 77..33.. ccaasstteelllliinnoo ddeell bbiiffeerrnnoo l’abitato di castellino del biferno è caratterizzato dalla presenza di due tipologie edilizie riferibili alla zona a e alla zona b descritte al punto 6. la distribuzione dei danni e le aree con costruzioni di diversa età e con diversa tipologia edilizia sono schematizzate in fig. 8. all’interno della zona a è presente una parte più antica (xi-xviii secolo), ubicata nel settore nordoccidentale, e una parte risalente quasi esclusivamente al xix secolo. nella parte più antica molte abitazioni non erano normalmente utilizzate e presentano importanti carenze di manutenzione. questa situazione, unitamente alla presenza di importanti fenomeni franosi già conosciuti e studiati da tempo (ufficio tecnico del comune di castellino del biferno, com. pers.), ha fatto si che i danni più rilevanti si siano verificati proprio sulle abitazioni della zona a. inoltre dall’analisi fotogeologica emerge la presenza di alcune limitate deformazioni gravitative profonde nell’estremo settore nord del centro abitato. tale area è inoltre interessata a ne e a sw da estesi fenomeni franosi complessi di scivolamento e colate. dall’esame della situazione geologica illustrata in figura 5 non sembra ipotizzabile alcuna relazione tra le litologie affioranti e i danneggiamenti, sembra invece probabile un forte condizionamento dovuto allo sviluppo dei fenomeni franosi sopra descritti. 77..44.. mmoorrrroonnee ddeell ssaannnniioo l’abitato di morrone del sannio è caratterizzato dalla presenza di tutte le tipologie costruttive descritte al punto 6. la distribuzione dei danni e le aree con diversa tipologia edilizia sono schematizzate in fig. 8. nella zona a, molte abitazioni erano in disuso e quindi presentano importanti carenze di manutenzione. questa situazione, unitamente alla presenza di importanti fenomeni franosi già conosciuti e studiati da tempo (ufficio tecnico del comune di morrone del sannio, com. pers.), ha fatto si che i danni più rilevanti si siano verificati proprio sulle abitazioni della zona a. il settore a sw della zona a risulta infatti caratterizzato da fenomeni franosi coalescenti, complessi, di crollo e locali scivolamenti e colate. in particolare le frane complesse prendono origine proprio in corrispondenza del passaggio litologico arenarie-argille. anche i danni evidenziati nella zona b possono essere in gran parte addebitati alla riattivazione di un fenomeno franoso all’interno del centro abitato, peraltro già conosciuto, la cui origine va probabilmente imputata all’attività di sottostanti aree in frana. dall’esame della situazione geologica illustrata in figura 5 non sembra ipotizzabile alcuna relazione tra le litologie affioranti e i danneggiamenti, che invece appaiono fortemente condizionati da fenomeni franosi attivi sul versante sw che delimita l’abitato di morrone del sannio. 77..55.. ppiieettrraammoonntteeccoorrvviinnoo l’abitato di pietramontecorvino è caratterizzato dalla presenza di tutte le tipologie costruttive descritte al 95caratteristiche geologico-geomorfologiche ... 96 fig. 8 quadro urbanistico (a, c, e, g) e distribuzione del danno (b, d, f, h) negli altri centri indagati (si veda teso per dettagli). urbanistic framework (a, c, e, g) and damage distribution (b, d, f, h) at other investigated localities(see text for details). b. giaccio et al. punto 6. la distribuzione dei danni e le aree con costruzioni di diversa età e con diversa tipologia edilizia sono schematizzate in figura 8. la maggior parte dei danni è concentrata nel settore centrale della zona a. ciò è molto probabilmente legato sia alle caratteristiche costruttive scadenti che alla presenza di un fenomeno franoso, già da tempo noto e studiato (ufficio tecnico del comune di pietramontecorvino, com. pers.), la cui evoluzione è legata a deformazioni lente superficiali che caratterizzano il sottostante vallone. i danni evidenziati nelle zone b e c sono in gran parte riferibili alla scarsa manutenzione degli edifici. dall’esame della situazione geologica illustrata in figura 5 non sembra ipotizzabile alcuna relazione tra le litologie affioranti e i danneggiamenti. l’influenza diretta del sisma sull’evento di frana ai fini del danneggiamento della zona a sembrerebbe invece la causa più probabile. 88.. ccoonncclluussiioonnii lo studio geologico-geomorfologico e l’analisi delle tipologie costruttive hanno fornito dati per una valutazione degli effetti di sito in san giuliano e in via preliminare in altri fra i centri abitati più colpiti dal terremoto del molise. l’approccio multidisciplinare e la comparazione di questi dati con la distribuzione del danno, hanno inoltre permesso di valutare l’effettivo contributo che ognuno dei fattori geologici, geomorfologici e di qualità del costruito ha avuto nel determinare un eventuale amplificazione locale. i risultati evidenziano, nel caso di san giuliano di puglia, una relazione diretta tra danneggiamento e condizioni geologico-strutturali e litologiche dei terreni di fondazione. infatti, a parità di altre condizioni, nell’area che ha subito i danni più gravi, affiorano i sedimenti argilloso-marnosi della parte alta del membro marnoso argilloso calcareo del flysch di faeto e/o della formazione del toppo capuana, mentre gli edifici solo leggermente danneggiati sono fondati sui sedimenti prevalentemente calcarei delle porzioni più basse flysch di faeto. la distribuzione di queste litologie risulta condizionata da un assetto strutturale caratterizzato da pieghe e sovrascorrimenti a vergenza appenninica, complicato da scaglie tettoniche fuori sequenza. va tuttavia sottolineato che la relazione tra danni e geologia è particolarmente evidente solo per le tipologie edilizie della zona a (fig. 7). questa presenta, infatti, il massimo danneggiamento in corrispondenza dei depositi argillosi o colluviali ed un livello di danneggiamento moderato o lieve per gli edifici fondati sui depositi calcarenitici del flysch di faeto. al contrario le tipologie edilizie della zona c, in larga misura costituite da edifici con struttura in cemento armato, hanno subito danni uniformi e nel complesso decisamente lievi, indipendentemente dalle litologie dei terreni di fondazione (fig. 7b). in altri termini, si registra una risposta differenziata agli effetti di sito legati alla litologia, con massimi risentimenti per le tipologie edilizie più vulnerabili (classe a) ed effetti minimi su edifici realizzati con tecniche moderne. negli altri centri esaminati (castellino del biferno, morrone del sannio, pietramontecorvino e ripabottoni,) nel complesso gli effetti di sito appaiono invece più legati a fenomeni gravitativi e di dissesto franoso preesistenti, ma riattivati dallo scuotimento sismico. simili osservazioni trovano un sostanziale accordo anche con le conclusioni di galli et al. (2003). ciò nonostante, visto il carattere preliminare degli studi condotti in questi centri, le conclusioni qui proposte vanno comunque intese come indicazioni provvisorie che necessitano di ulteriori dati attualmente in corso di acquisizione. decisamente più esaustivo appare invece l’insieme di dati raccolti per s. giuliano. nel quadro delineato, appare infatti plausibile che il forte danneggiamento registrato in alcuni settori dell’abitato, anomalo nell’ambito del rilevo macrosismico complessivo, sia da attribuirsi ad un significativo effetto di sito controllato dalle litologie e dalla struttura dei terreni di fondazione, con forti risentimenti su edifici con scadenti qualità costruttive. lo studio evidenzia quindi l’importanza delle indagini geologiche tradizionali (rilevamento, analisi strutturali e biostratigrafiche) come strumento propedeutico e integrativo per la microzonazione sismica in aree caratterizzate da una sismicità medio-bassa, ma da una edilizia vulnerabile e dalla presenza di corpi litologici argillosi deformati secondo un complesso stile tettonico a pieghe e sovrascorrimenti. rriinnggrraazziiaammeennttii alcuni autori (b.g. e s.c.) dedicano questo lavoro al fraterno amico francesco allocca (1967-2003), per molti anni nostro compagno e complice nel rifiutare ostinatamente la separazione tra i vincoli dell'amicizia e quelli della serietà e correttezza nel lavoro e nella ricerca scientifica. * * * si ringraziano i sindaci ed il personale degli uffici tecnici dei comuni di san giuliano di puglia, castellino del biferno, morrrone del sannio, pietramontecorvino, ripabottoni, ed il com di san giuliano di puglia, per le preziose informazioni e i materiali cartografici forniti; in particolare l’ing. g. angeli, a. fratangelo, e. fratangelo, m. frenza, a. iorio, dott. s. lamarucciola, a. malice, arch. f. mucelli e m. oto. ringraziamo p. lembo e g. naso del dipartimento della protezione civile per le discussioni sul campo. desideriamo infine ringraziare s. di nocera e p. galli per gli utili consigli e le critiche che hanno notevolmente migliorato la prima versione del manoscritto, ed inoltre i. sgrosso e m. torre per le proficue discussioni e i suggerimenti forniti nel corso della ricerca. bbiibblliiooggrraaffiiaa augell i p.c., cinque a. & rosskopf c. (2001) geomorphological map of the trigno basin (italy): explanatory notes. geografia fisica e dinamica quaternaria, 2244, 3-12. basso c., ciampo g., ciarcia s., di nocera s., matano f. & torre m. (2002) geologia del settore irpinodauno dell’appennino meridionale: unità mesocenozoiche e vincoli stratigrafici nell’evoluzione tettonica mio-pliocenica. studi geol. cam., nuova serie 22. boni a., casnedi r., centamore e., colantoni p., 97caratteristiche geologico-geomorfologiche ... cremonini g., elmi c., monesi a., selli r. & valletta m. (1969) note illustrative del foglio 155 – san severo. servizio geologico d’italia, 46 pp. bosi c., dramis f. & gentili b. (1985) carte geomorfologiche di dettaglio a indirizzo applicativo e carte di stabil i tà su base geomorfologia. geologia applicata e idrogeologia, 2200, 53-62. bouma a. h. (1962) sedimentology of same flysch deposits, a graphic approach to facies interpretation. elsevier co., 168 pp. braga f., dolce m. & liberatore d. (1982) a statistical study on damaged buildings an ensuing review of msk/76 scale. proc. 7th european conference on earthquake engineering, vol. 77, 431-450, athens, 1982. carrara a., caton a., dramis f., panizza m. & prestininzi a. (1987a) cartografia della pericolosità connessa con i fenomeni di instabilità dei versanti. boll. soc. geol. it., 110066, 199-221. carrara a., d’elia b. & semenza e. (1987b) classificazione e nomenclatura dei fenomeni franosi. geologia applicata e idrogeologia, 2200, 223243. chighira m. (1992) long-term gravitational deformation of rock by massrock creep. eng. geology. 3322 (3), 157-184. chilovi c., de feyter a. j. & pompucci a. (2000) wrench zone reactivation in the adriatic block: the example of the mattinata fault system (se italy). boll. soc. geol. it., 119, 3-8. ciaranfi n., dazzaro l., pieri p. & rapisardi l. (1981) i depositi del miocene superiore al confine molisano-abruzzese. boll. soc. geol. it., 9999, 103-118. crostella a. & vezzani l. (1964) la geologia dell’appennino foggiano. boll. soc. geol. it., 8833, 121-142. dazzaro l., di nocera s., pescatore t., rapisardi l., romeo m., russo b., senatore m., torre m. (1992) geologia del margine della catena appenninica tra il f. fortore ed il t. calaggio (monti della daunia app. merid.). mem. soc. geol. it., 4411, 411-422. di bucci d., corrado s., naso g., parotto m. & praturlon a., (1998) evoluzione tettonica neogenico-quaternaria dell'area molisana. boll. soc. geol. it., 111188, 13-30. di nocera s. & torre m. (1987) geologia dell'area compresa tra deliceto e scampitella (app. foggiano). boll. soc. geol. it., 110066, 351-364. finetti i. (1982) structure, stratigraphy and evolution of central mediterranean. boll. geof. teor. appl., 2244 (96), 247-312. foresi l.m., iaccarino s., mazzei r. & salvatorini g. (1998) new data on the calcareous plankton stratigraphy of the middle to late miocene (serravallian/tortonian) of the mediterranean area. riv. it. paleont. strat., 110044 (1), 95-114. galli p., molin d., giuliani r., bosi v., mattone m., gruppo quest (2003) i l terremoto del 31/10/2002: sismicità storica di san giuliano, rilievo macrosismico e deformazione superficiale cosismica. ingegneria sismica, 33, 8-18. gruppo di lavoro per la cartografia geomorfologica (1994) legenda della carta geomorfologica d’italia. servizio geologico nazionale, quaderni serie iii, vol. iv, roma. guerricchio a. & wasowski j. (1988) some remarks on the tectonic significance of the paleomagnetic data from gargano. mem. soc. geol. it., 4411, 12631269. istituto nazionale di geofisica e vulcanologia (2002) l'epicentro della scossa del 31 ottobre 2002 ore 11:32 e del 1 novembre 2002 ore 16:08. http://www.ingv.it/~roma/reti/rms/terremoti/italia/m olise/molise.html medvedev s.v. (1977) seismic intensity scale m.s.k.76. publ. inst. geophys. pol. acad. sc. a-6 (117), varsavia. messina p. & sposato a. (1985) osservazioni geologico tecniche sugli abitati più colpiti dal terremoto abruzzese del maggio 1984. geol. appl. e idrogeol., xx (i), 39-61. naso g., tropenscovino s. & sanò t. (2002) assetto geologico ed effetti di amplificazione sismica a s. giuliano di puglia (molise). servizio sismico nazionale, http://www.serviziosismico.it/rt/rrp/ 021031/amplif/amplif.htm. okada h. & bukry d. (1980) supplementary modification and introduction of code numbers to the lowlatitude coccolith biostratigraphic zonation (bukry, 1973; 1975). marine microplaeontology, 5511, 321325. onida m., (2001) deformazioni gravitative profonde di versante: stato della conoscenza e progresso della ricerca in italia. in: g. pasquarè (ed), tettonica recente e instabilità di versante nelle alpi centrali. fondazione cariplo e cnr istituto per la dinamica dei processi ambientali, milano, italy, pp. 35-74. parise m. (1994) il rilevamento geomorfologico a grande scala nell’interpretazione della cinematica dei movimenti gravitativi. geologica romana, 3300, 273282. patacca e., sartori r. & scandone p. (1990) tyrrhenian basin and apenninic arcs: kinematic relations since late tortonian times. mem. soc. geol. it., 45, 425-451. patacca e. & scandone p. (1989) post-tortonian mountain building in the apennines. the role of the passive sinking of a relic lithospheric slab. in: boriani et al. (eds), the lithosphere in italy). atti dei convegni lincei, 8800, 157-186. patacca e., scandone p., bellatalla m., perilli n. & santini u. (1992) la zona di giunzione tra l'arco appenninico settentrionale e l'arco appenninico meridionale nell'abruzzo e nel molise. studi geologici camerti, vol. spec. crop 11 (1991/92), 417-441. pescatore t., russo b., senatore m.r., ciampo g., esposito p., pinto f., staiti d. (1996) la successione messiniana della valle del t. cervaro (appennino dauno, italia meridionale). boll. soc. geol. it. 111155, 369-378. piccardi l. (1998) cinematica attuale, comportamento sismico e sismologia storica della faglia di monte sant'angelo (gargano, italia): la possibile rottura superficiale del "leggendario" terremoto del 493 d.c. geogr. fis. dinam. quat., 2211, 155-166. russo b. & senatore m.r. (1989) ricerche sull’unità dauna: biostratigrafia e sedimentologia della suc98 b. giaccio et al. cessione di monte sidone nell’appennino dauno (italia meridionale). atti acc. peloritana dei pericolanti, classe i di sc. fis., mat. e nat., vol. 6677, suppl. 1, 79-87, messina santo a. & senatore m.r. (1988) la successione stratigrafica dell ’unità dauna a monte sidone (castelluccio valmaggiore, foggia). mem. soc. geol. it., 4411, 431-438. selli r. (1962) il paleogene nel quadro della geologia dell'italia meridionale. mem. soc. geol. it., 33, 738789. senatore m.r. (1988) comparazione tra i depositi pliopleistocenici del bacino di gallipoli (golfo di taranto) e la successione miocenica del flysch di faeto (unità irpine, monti della daunia): confronto tra l ’avanfossa attuale e quella miocenica dell’appennino meridionale (italia). tesi di dottorato, università di napoli, 317 pp. servizio geologico d’italia (1969) foglio 155 “san severo”. carta geologica d’ital ia in scala 1:100.000. servizio sismico nazionale (2002) sintesi del danno agli edifici e delle tipologie edilizie prevalenti. servizio sismico nazionale. http://www.serviziosismico.it/rt/rrp/021031/danni/danni.pdf. sgrosso i. (1998) possibile evoluzione cinematica miocenica nell'orogene centro-sud appenninico. boll. soc. geol. it., 111177, 679-724. sorriso valvo m. (1995) considerazioni sul limite tra deformazione gravitativa profonda di versante e frana. mem. soc. geol. it., 50, 179-185. varnes d.j. (1978) slope movement types and processes. in r.l. schuster & r.j. krizek (eds.), landslides, analysis and control. transportation research board sp. rep. n. 176, nat. acad. of sciences, washington. wells d. & coppersmith k. (1994) new empirical relationships among magnitude, rupture length, rupture width, rupture area and surface displacement. bull. seismol. soc. am., 8844, 974-1002. 99 ms. ricevuto il 15 luglio 2003 testo definitivo ricevuto il 16 marzo 2004 ms. received: july 15, 2003 final text received: march 16, 2004 caratteristiche geologico-geomorfologiche ... available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 89 92 human resilience and the climatic impact of greenland stadial 5 on the landscape of the northern apennine watershed. an assessment based on multidisciplinary data from the piovesello gravettian site marco peresani 1 , cesare ravazzi 2 , roberta pini 2 , davide margaritora 1 , arianna cocilova 1 , davide delpiano 1 , stefano bertola 1 , lorenzo castellano 3 , gabriele martino 4 , cristiano nicosia 5 1 university of ferrara, dipartimento di studi umanistici, sezione di scienze preistoriche e antropologiche, ferrara, italy 2 cnr idpa, research group on vegetation, climate, human stratigraphy lab. of palynology and palaeoecology, milano, italy 3 new york university, institute for the study of the ancient world, new york, usa 4 sopr. archeologia, belle arti e paesaggio città di genova e province di imperia, la spezia e savona, genova, italy (collaborator) 5 university of padova, dipartimento dei beni culturali, padova, italy corresponding author: m. peresani <psm@unife.it> abstract: the gravettian settlements of europe are considered as an expression of the human adaptation to harsh climates. in southern europe, however, favorable vegetation-climate conditions supported hunters-gatherers subsistence and the maintenance of their large-scale networks. this was also the case of the north-adriatic plain and the apennine mountain ridge in italy, where the ephemeral site of piovesello locates at 870 m a.s.l. cultural and palaeobotanical evidence allows to reconstruct human and vegetation ecology at a glaciated area in the northern apennine during greenland stadial 5 and also provides hints for the historical biogeography of petrophytic plants and their orographic relics. keywords: human settlement, palaeoecology, mountain timberline, gravettian, apennine watershed 1. introduction the greenland stadial 5 at the onset of mis2 was an extreme cold phase of the late pleistocene, impacting the gravettian hunter gatherers population across western eurasia. in central-northern europe, ecological contexts on the loess belt during mis2 and especially the lgm were mostly treeless and provided limited resource availability. however, the settlement patterns documented in those periglacial environments are a demonstration of human culturally-mediated capability to overcome conditions of reduced biomass and ecological variability (maier et al., 2016). in southern europe, milder latitudinal conditions and enhanced moisture supply at the northern mediterranean rim allowed the growth and forest ecosystems of boreal type including mountain forests, which supported megaherbivores diffusion, a rather favourable conditions for hunters-gatherers subsistence and their maintenance of large-scale networks. although this general picture has been largely confirmed by lowland open-air and cave sites which record multiple frequentations (bocquetappel et al., 2005), little is known from those potentially inhabitable landscapes situated on the mountain range at extreme conditions. despite the low density of lithic objects, these contexts contribute to reinforce our inferences about the existence of a wider settlement system in which specific anthropic activities were spatiotemporally displaced (foley, 1981). however, whenever investigations are carried out and clusters of sites are disclosed, this pattern may be re-designed to reflect prehistoric reality. it is the case of the following contribution which provides valuable information for the reconstruction of human ecology in the northern italian apennines during a critical period for european human population. the availability of both microscopic plant remains and wood charcoal from a mountain site, connected with traces of anthropic presence, provides a chance to obtain unprecedented insight about terrestrial ecosystems and human activities on the northern apennine watershed at around 30 ka ago (peresani et al., in press). 2. material and methods the main bulk of data here presented has been achieved from interdisciplinary data issued from investigations carried out in the gravettian site of piovesello, situated at 870 m a.s.l. on the mount camolara-ragola close to the northern apennine watershed (fig. 1): archaeological and geoarchaeological field investigation including soil micromorphology; palaeoecological analysis of charcoal, pollen and other microbiological particles from bulk sediments and a core; radiocarbon dating; petrographic and techno-typological analyses of the lithic industry. https://doi.org/10.26382/aiqua.2018.aiquaconference 3. results reconstruction of the pedo-sedimentary processes were based on field features and micromorphology and show that the origin of the piovesello sequence is strictly linked to a series of medium-low energy colluvial processes settling a small basin shaped in an ophiolitic bedrock. four pollen zones are distinguished, with arboreal pollen (ap) values ranging from ca. 30% up to 81%, mostly referred to pinus sylvestris/mugo type, whereas most part of the pollen grains identified belongs to upland herbs (mostly compositae subfam. cichorioideae) with pollen diversity increasing upwards along the core among upland herbs, with the occurrence of four different types of dipsacaceae pollen and the highest concentrations of charcoal fragments related to the human presence. the charcoals from the su7, the only layer yielding archaeological traces shows a monospecific assemblage, as only scots and/or dwarf mountain pine were identified. based on the complete range summing up the two ages obtained from the charcoal (i.e. 29433 – 30681, 2σ calibration interval), the site is falling within the cold stadial phase gs 5.1 according to the intimate event stratigraphic scheme for the north atlantic and europe subcontinent (rasmussen et al., 2014). petrographic and archaeological data prove the local provenance of radiolarite blocks and slabs represented by a rather wide diversity in technological products alongside with many complex refittings, which hint to an on-place exploitation. in addition, a handful of cores and finished artifacts made on flint (chert) prove provenance from haute provence, 300 km to the west. 4. discussion and conclusion the human settlement at piovesello open air site falls in the greenland stadial 5.1, possibly in connection with a culmination of local glaciers, whose late pleistocene frontal moraines lies at only 600 m from the site (fig. 1). this phase, however, predates both the early glacial culmination of the last glacial maximum in the alpine realm (monegato et al., 2017), and precedes the most intense phase of forest withdrawal in n-italy, the latter event being coeval to the lgm onset (fig. 2). although the site was located in the altitudinal open belt above the timberline, meanwhile the stable surfaces in the po plain still supported mixed pine-birch forests (garozzo et al., this volume). the unprecedented palaeobotanical documentation, directly associated to the artefacts-bearing layer, includes pollen of rocky semidesert plants, but also pine wood banches carried up to the site by gravettians and used as fire fuel. in turn, this pine charcoal made possible to obtain high-precision radiocarbon ages. this is not a novelty for the mid-late palaeolithic settlers of europe who have largely demonstrated to adapt to environments well above the timberline and also well inside the limit of continuous permafrost in a largely treeless landscape with semidesert, tundra and steppe prevailing (maier et al., 2016). furthermore, the impact of gs5 to human ecosystems is under the focus of on-going investigations in northern to eastern europe. despite the sparseness of the archaeological record, in some parts of europe from russia to the paris basin seems to be a hiatus in occupation in this time 90 peresani m. et al. fig. 1 a large scale digital terrain model and simplified geological setting of the upper val nure on the northern apennine watershed, showing topographic relationships between the new gravettian site, the location of the upper palaeolithic workshop on monte lama ophiolitic sedimentary body, and the mont ragola ophiolitic massif. notice lgm glacier development on mont ragola and widespread landslides. 91 span suggested by a revised chronology (see peresani et al., in press for references). by contrast, in western mediterranean regions hunter-gatherers lived in cool and cold-temperate, often moister environments, with higher biomass and human population density than in central europe. despite the aforementioned uneven distribution of early gravettian sites in the italian peninsula and the relatively scanty evidences of human presence, estimates of human population size point to the largest regional settlement area in western europe benefiting from suitable conditions for biomass growth (maier et al., 2016). these environments forced wide or altitudinal movements along mountain timberline gradients aimed to cover high range of logistical mobility. acknowledgements research at piovesello is coordinated by the ferrara university and the national research council of italy in the framework of an archaeological project supported by the ministry of culture – emilia-romagna archaeological superintendency and public institutions (ferriere municipality, natural history museum of milano, natural history museum of piacenza). palaeoecological analyses were carried out in the framework of the cnr-idpa palaeoclimatology research line dta.ad001.112. references bocquet-appel j.p., demars p.y., noiret l., dobrowsky d. (2005) estimates of upper palaeolithic metapopulation size in europe from archaeological data. journal of archaeological science, 32, 16561668. giraudi c. (2015) the upper pleistocene deglaciation on the apennines (peninsular italy). cuadernos de investigación geográfica, 41, 337-358. lüetscher m., boch r., sodemann h., spötl c., cheng h., edwards r.l., frisia s., hof f., müller w. (2015) north atlantic storm track changes during the last glacial maximum recorded by alpine speleothems. nature communications, 6. maier a., lehmkuhl f., ludwig p., melles m., schmidt i., shao y., zeeden c., zimmermann a. (2016) demographic estimates of hunter-gatherers during the last glacial maximum in europe against the background of palaeoenvironmental data. quater human resilience during greenland stadial 5 on the northern apennine watershed fig. 2 the chrono-climatic setting of the piovesello site compared with hemisphaeric, alpine and apennine climate proxies. a lake fimon and tenaghi philippon pollen records as summarized by % of woody plants, from wick (2000), pini et al. (2010), muller et al. (2011); panel b greenland ice core intimate chronology from rasmussen et al. (2014); c north atlantic heinrich events; d delta 18o record from speletheme 7h, bernese alps, from lüetscher et al. (2015); e glacier advances in the apennines from giraudi (2015); f glacier advances of garda and tagliamento glaciers in their pedemontane moraine systems, eastern italian alps; distance from the valley outlet in km, modified from monegato et al. (2017). nary international, 425, 49-61. monegato g., scardia g., hajdas rizzini f., piccin a. (2017) the alpine lgm in the boreal icesheets game. nature scientific reports, 7. müller u.c., pross j., tzedakis p.c., gamble c., kotthoff u., schmiedl g., wulf s., christanis k. (2011) the role of climate in the spread of modern humans into europe. quaternary science reviews, 30, 273-279. peresani m., ravazzi c., pini r., margaritora d., cocilova a., delpiano d., bertola s., castellano l., fogliazza f., martino g., nicosia c., simon p. (in press) human settlement and vegetationclimate relationships in the greenland stadial 5 at the piovesello site on the northern apennine watershed. quaternary research. pini r., ravazzi c., reimer p. (2010) the vegetation and climate history of the last glacial cycle in a new pollen record from lake fimon (southern alpine foreland, n-italy). quaternary science reviews, 29, 3115-3137. rasmussen s.o., bigler m., blockley s.p., blunier t., buchardt s.l., clausen h.b., cvijanovic i., dahl-jensen d., johnsen s.j., fischer h., et al. (2014) a stratigraphic framework for abrupt climatic changes during the last glacial period based on three synchronized greenland ice-core records: refining and extending the intimate event stratigraphy. quaternary science reviews, 106, 14-28. wick l. (2000) fullto late-glacial vegetation and climate changes and evidence of glacial refugia in the south-eastern alps (italy). in colombaroli d., kaltenrieder p., vescovi e., tinner w., (eds) xxx international moorexcursion 2006 northern and central italy, 53-55. 92 peresani m. et al. ms. received: april 29, 2018 final text received: may 29, 2018 imp.panizza&piacente geomorphosites: a bridge betwenn scientific research, cultural integration and artistic suggestion mario panizza & sandra piacente dipartimento di scienze della terra, università degli studi di modena e reggio emilia largo s. eufemia, 19 – 41100 modena pit@unimore.it; piacesan@unimore.it abstract: m. panizza & s. piacente, geomorphosites: a bridge betwenn scientific research, cultural integration and artistic suggestion. (it issn 0394-3356, 2005). the authors start with noting that the geological aspects has not yet assumed its proper value as a cultural asset. this seems to derive above all from a static approach and museum-like view of our geological heritage current in society, that have limited its meanings and potentialities considerably. now there is a very important occasion for re-launching geology as a cultural and social discipline though some activities that can be summarised in three main fields. scientific research on geosites which are one of the components of the cultural heritage of a given territory as well as works of art, fauna and flora etc. cultural integration between the geological-geomorphological aspects of a territory and the other landscape components (biological, historical, artistic etc.) within a concept of “integrated cultural landscapes”. artistic suggestion of those geological sites which have been source of literary, pictorial, musical etc. inspiration. for each of the above mentioned fields some different characteristic examples are highlighted. riassunto: m. panizza & s. piacente, geomorfositi tra ricerca scientifica, integrazione culturale e suggestione artistica. (it issn 0394-3356, 2005). gli autori partono dalla constatazione che gli aspetti geologici non hanno ancora assunto il valore di bene culturale. ciò sembra derivare sopratutto da una percezione statica e da una visione museografica con cui il patrimonio geologico viene tuttora percepito, che ne limitano fortemente i significati e le potenzialità. attualmente si sta presentando un’occasione molto importante per il rilancio della geologia che potrebbe e dovrebbe trovare inedite vocazioni culturali e sociali. le attività per tale rilancio possono essere schematicamente raggruppate in tre campi principali. ricerca scientifica dei geositi, che rappresentano una delle componenti del patrimonio culturale di un dato territorio così come monumenti, flora, fauna etc. integrazione culturale tra gli aspetti geologico-geomorfologici di un territorio e le altre componenti del paesaggio (biologica, storica, artistica etc.) nel concetto di “paesaggio culturale intergrato”. suggestione artistica di quei siti geologici che sono stati fonti di ispirazioni letterarie, pittoriche, musicali etc. di ciascuno dei campi sopra citati vengono illustrati alcuni esempi significativi. keywords: geomorphosites, scientific research, cultural integration. parole chiave: geomorfositi, ricerca scientifica, integrazione culturale. il quaternario italian journal of quaternary sciences 18(1), 2005 volume speciale, 3-10 1. forward in a modern society like ours, where environmental problems are usually pressing and urgent, earth sciences still occupy a marginal role. this is hardly justifiable if we consider the importance they have actually had and will have in the history and development of life and civilisation. it is therefore necessary to find new paths and strategies in order to spread better information and communication which can fill this gap. in particular, the geological aspect has not yet assumed its proper value as a cultural asset. therefore, before proposing its conservation and appraisal, its status must first be recognised and new strategies for spreading information must be found, which can reach not so much in the scientific and institutional world but rather society at large. the static approach and museum-like view of our geological heritage current in society so far, have limited its meanings and potentialities considerably. furthermore, the nearly total lack of a tradition of communication and education in geological sciences has contributed to causing a delay both in understanding and in arousing an awareness of the cultural value of geology in society. this is a very important occasion for re-launching geology as a cultural and social discipline. we should therefore define a geological space where nature itself can offer inspirations for finding the best relationship with man, the right “distance” (secchi, 2001): metric, visual, sensorial and symbolic or suggest new practices for territorial management. this need has become ever more felt in the past few years which have been characterised by a marked democratisation of the space around us and its usage. new impulses and expectations are opening up new ways, hardly ever followed before, as confirmed by the activities of ecologist associations, public boards, protection agencies and government norms. all this has 4 m. panizza & s. piacente been accompanied by research programmes carried out at a national and international level, such as the research programme activated by unesco, progeo, the international association of geomorphologists and confirmed in their provisions, in particular in articles nos. 1 and 6 of the “european convention on landscape” (florence, 2000). all the interventions, perspectives and goals of these activities can be summarised in three main fields. scientific research on geosites which are one of the components of the cultural heritage of a given territory as well as works of art, fauna and flora, etc. cultural integration between the geological-geomorphological aspects of a territory and the other landscape components (biological, historical, artistic etc.) within a concept of “integrated cultural landscape”. artistic suggestion of those geological sites which have been the source of literary, pictorial, musical etc. inspiration. the above described points will be developed by making reference to the experiences so far achieved by the authors at a local, national and international level. these experiences have mainly interested sites of geomorphological interest which have been defined as “geomorphosites” (panizza, 2001; panizza & piacente, 2003). 2. scientific research basic investigations have been carried out and applied research projects have been implemented or are still in progress with funds from italian ministries, the european union and by means of conventions with public boards. investigations, which started some 20 years ago, have been developed with the following aims: to emphasise and assess the relationships between physical landscape and quality of the environment and between development of geomorphological knowledge and socioeconomic development (panizza, 1988; panizza, 1989a; panizza, 1990a; panizza, 1990b; panizza, 1990c; panizza & piacente 1991; panizza, 1992b; panizza & piacente, 1993; panizza, pellegrini & pozzi (1993), panizza & piacente, 1999a; panizza & piacente, 1999b; piacente, 1999a; piacente, 1999b; panizza & piacente, 2000; panizza, 2001; panizza, 2003; piacente, 2003; piacente & poli, 2003; panizza & piacente, 2003). to define a methodology for the identification and census of geosites (panizza, 1992b; carton et al., 1994; panizza & piacente, 1999a, 1999b; bertacchini et al., 1999; bertacchini et al., 2001; panizza & piacente, 2003). to present and test in different environmental contexts a catalogue card linked to a computer-based archive (bertacchini et al., 1999; bertacchini et al., 2002a; piacente & poli, 2003). to provide an example of geo-referenced mapping sites within a given regional territory (castaldini et al., 1997; bertacchini et al., 1999; piacente et al., 2001). to set up a thematic itinerary, where a geosite can be transformed from a “geological object” into a “cultural asset” available to the public (panizza & spampani,1988, 1989; panizza 1989a, panizza 1989b; piacente 1989; carton & panizza,1991; piacente et al., 2000; bertacchini et al., 2002b; piacente et al., 2001; panizza & piacente, 2003). to organise educational projects in which the curricula carried out can offer the opportunity to bring students from all levels closer to field geology, during their normal period of cultural formation (piacente & soldati, 1989; piacente & giusti, 2000; panizza & piacente, 2001; bertacchini et al., 2002; piacente & poli, 2003, panizza & piacente, 2003). starting from these observations, our investigations have tried to turn the complex environment-geological asset system into a language accessible to the widest possible public, even in unusual ambits, such as the elderly, the disabled and young children, making use of local forces and resources and involving young and old in a privileged role: the former in the educational and professional phase, and the latter in conveying experiences and values, using the past as a preparation for the future. 3. cultural integration a landscape is to be appreciated with all its physical, biological, historical, architectonic etc. components, it can then be considered a primary cultural asset resulting from complex relationships. there is now the awareness that only an in-depth understanding of all the environmental components of a territory and their history can lead to proper conservation and management initiatives. naturally, the first source of understanding lies in the territory itself, with its geological structure and its morphological features. then we have to consider interventions made by man on the natural elements. lastly the archaeological, historical, socioeconomic, etc. elements must be fully taken in. therefore, the relationships and reciprocal influences between physical landscape and cultural assets (here considered in a strict sense, that is the above mentioned archaeological, historical, architectonic etc. assets) should be identified. as regards research methodology, five operational phases can be identified (panizza & piacente, 2000). the first phase consists of a physical setting of the territory in which the cultural (i.e. historical and architectonic) asset is located, in terms of geological and geomorphological evolution, in terms of resources (raw materials, lithology, morphology, hydrology etc.) and in terms of stability and, therefore, of natural hazards (disarray processes, landslides, floods, earthquakes, volcanic eruptions etc.). subsequently, the geomorphological causes which have conditioned the location of a cultural asset should be taken into account. in fact, if the construction of a historicalarchaeological site generally responds to the socioeconomic needs (housing, religious practices, defence etc.) of a given community over a given territory, at the same time the particular location selected is chosen also on the basis of its environmental characteristics. among these, for example, the lithological characteristics, owing to the availability of building materials, the hydrological characteristics, owing to the presence of a watercourse, the geomorphological characteristics, owing to the presence of a naturally sheltered area or a look-out point and so on. subsequently, it will be necessary to assess whether a given cultural asset may be affected by natural hazards (in our case, geomorphological hazards) and, consequently, subject to risks. in this case, defence and mitigation interventions must be planned. furthermore, it should be assessed whether the possible fruition of a cultural asset – for example following social or tourism initiatives – may bring about negative consequences for the natural, in particular for the geomorphological, environment in terms of environmental impact. finally, it should be taken into account that the correct management of a historical-archaeological asset cannot be separated from its knowledge integrated in the surrounding environment (panizza & piacente, 1991; 1999a). in this way the proper fruition of both aspects will be implemented, with a positive spin-off from the socioeconomic viewpoint, also as regards conservation and appraisal. this sort of activity, including all promoting and protecting initiatives and measures, must necessarily be based on interdisciplinary studies and multiple management of environmental education initiatives. another significant example is offered by montsaint-michel. this is a granite islet, located in the bay bearing the same name near the mouth of the couesnon river. on top of the islet, various monumental buildings were constructed, making it one of the most interesting and typical places of northern france (fig. 1). at the centre of this historical-artistic complex there is a benedictine abbey overlooking the cliff. the original core of this monumental area was an oratory dating from the year 708, which was dedicated to st. michael. later, a carolingian church was built (x century), a romanesque abbey (xi-xii century), a monastery and a gothic cloister and a choir (xiii to xv century). one of the most singular characteristics of this site is its cyclic isolation from the mainland caused by the alternation of low and high tide. this is a magic, constantly transforming landscape, where another “tide” has been flowing in for centuries: first pilgrims, and nowadays, prevalently, tourists. like all bays, even montsaint-michel bay is subject to silting. this natural process has increased with time owing to various human activities carried out through the centuries: dams, canals and locks built on the course of the river couesnon resulted in a decrease of its stream velocity and flow rate. as a consequence, this watercourse lost the energy necessary to evacuate the debris materials deposited at its mouth causing also a decrease of the ebb current. a further consequence of this activity was the development of a particular marine flora which retains 5geomorphosites: a bridge between ... the sediments in the bay. furthermore, the road on an artificial embankment which links the little island to the mainland has modified the original aspect of the area. an interdisciplinary study involving hydraulics, geomorphology, biology etc., and laboratory analysis utilising a model of the environmental situation have allowed a solution to be identified for re-establishing the original conditions. a mobile dam able to control the runoff of the r. couesnon will be built and one of its branches will be diverted in order to decrease the amount of solid load towards mont-saint-michel. in this way the combined sea/river action will be enhanced in order to increase the ebb current which, in turn, would wash away part of the debris. the embankment road will be substituted with an “ecological shuttle” on a footbridge. within forty years, the sea floor between the islet and the mainland should be lowered by about 70 m and the surrounding marine floors should gain some 50 ha. all this should take place without compromising the traditional activities of the inhabitants, such as mussel farming and fishing on foot. the unique landscape of this special site will therefore be recreated “where sea and man have united to give origin to this masterpiece of human heritage”. in order to negotiate more specifically the relationships between geomorphology and cultural assets (in a strict sense), three types of conceptual approaches may be identified and, consequently, three types of methodological approaches (panizza, 2003): an environmental approach, a historical approach and a cultural approach (in a broad sense). these different procedures are strictly derived from the multidisciplinarity of the research; therefore they do not make up factors of discrimination or criticism, since the different points of view are directed to the pursuit of the same goal. fig. 1 the mont saint michel, in northern france, with the benedictine abbey architectonic complex. il mont saint michel, nella francia settentrionale, con il complesso architettonico dell’abbazia benedettina. 6 3.1 environmental approach the environmental approach is based on the relationships between the environment (in particular geomorphological) and archaeological, historical-architectural etc. assets, in conformity with a scheme in which the environment can be considered according to two points of view: on the one hand we have landscape resources (e.g. geomorphosites), and, on the other hand, geomorphological natural hazards (degradation, disarray etc.). in turn, cultural assets (in a strict sense) may be considered as both vulnerability (i.e. susceptible to material damage) and sites for fruition activities (e.g. tourism). these relationships may produce situations of either risk or impact (panizza, 1992a). an example of geomorphological risk is offered by the valley and adjacent hill of the temples of agrigento (cotecchia et al., 2000). the conservation of this site, which is a unique case of world relevance owing to its historical, archaeological, artistic and anthropological value, has been seriously threatened by both geomorphological disarray processes and man’s activity. in particular, the situation of the temples of juno lacinia and concordia, which are aligned along the southern edge of the hill, is very serious since the calcarenites making up the slope are affected by rock falls, topples and rotational slides, with involvement also of the underlying clay shales. examples of risk linked to chemical weathering are those resulting from sulphatization processes, which cause disaggregation of calcareous artefacts through the action of precipitation water made more aggressive by sulphur compounds produced by the combustion of coal. similar processes can occur on the basement of buildings where humidity is higher. in other cases hydrolysis processes may trigger differential erosion in buildings made up of materials with feldspar components and others constructed with more resistant types of materials. a well-known example of environmental risk and impact is offered by the situation of venice: recurrent “high water” has determined risk conditions whereas strong anthropic pressure has caused considerable degradation of the ecological, physical and biological standards of the lagoon environment. another example is mount sinai near the monastery of saint catherine (fig. 2), where there are ever increasing numbers of tourists, owing to the strong appeal of this site where, according to the old testament, moses received the tablets of the law from god. interest in this site is becoming more and more consistent also in relation to tourism infrastructures, which are expanding at a considerable rate near the seaside villages on the red sea, such as sharm el sheik. in this case, progressive remodelling and flattening of the slopes is taking place in order to create areas for building new hotels and related structures, with heavy consequences for environmental impact. 3.2 historical approach this approach is based on history considered as a factor of interpretation, that is on the concepts of continuity and integration between the present landscape and, going back in time, its history, prehistory and, finally, geohistory. for example, we may refer, on the one hand, to the relationships between social, strategic or religious needs and, on the other hand, to the geomorphological constraints of a particular site. our purpose is to analyse the landscape and recognise in it the integrations and relationships which have been established through time, by interpreting in an interdisciplinary manner all its “historical” components (in a broad sense) (panizza & piacente, 2000). examples can be as follows. a first explanatory case is offered by the balzi rossi (= red cliffs) (fig. 3), near ventimiglia (liguria): one can start from its geohistory (dolomite limestones from the upper jurassic, with tectonic joints), geomorphological genesis (sea cliff, karst modelling, littoral erosion and sedimentation, marine regressions and transgressions, reddish weathering of iron minerals, hence the name of “red cliffs” etc.), up to the arrival of man in the lower palaeolithic. in particular, the remains of the most ancient settlements were wiped out by the marine transgressions of the interglacial periods, which stretched as far as the caves, reworking prehistoric artefacts and deposing beach sediments, like those dating from the tyrrhenian (150,000-75,000 years bp). one of the most important discoveries consists of a three-fold burial from the upper palaeolithic (dated between 30,000 and 25,000 years bp). the latest “historical” evidence is given by the remains of military forts from the second world war and the inadequacy of the area for fruition by tourists. m. panizza & s. piacente fig. 2 example of environmental impact in the sinai, near the monastery of st. catherine. various parts of this territory appear remodelled and flattened for the construction of buildings and tourist infrastructures. esempio di impatto ambientale nel sinai, presso il monastero di santa caterina; vari settori del territorio appaiono rimodellati e spianati per la costruzione di edifici e infrastrutture turistiche. 7 another example is offered by the rocky cliff of vallerano in the province of viterbo (margottini, 2002), with a cave-dwelling containing frescoes depicting jesus christ as the saviour. this is a cliff made up of volcanic rocks from the vicus apparatus, dated between 200,000 and 150,000 years bp, in which a human dwelling of probable prehistoric origin was excavated. this site was subsequently remodelled and used by benedictine monks who turned it into a place of worship with rare frescoes, presumably ascribable to the ix-x century a.d. on the cave’s left-side wall the saviour is depicted, flanked by st. peter and an angel, whereas, on the bottom wall, a group of saints is shown. these frescoes, which stand out from a background adorned with multi-coloured frames, seem to be the work of an important byzantine artist. this cave was brought to light in the xix century, following a collapse that destroyed its outermost wall which was probably also frescoed. its rocky wall shows evident signs of geomorphological instability which point to progressive deterioration that could eventually lead to the disappearance of this settlement and the works of art housed in it. geomorphological investigations (margottini, 2002) have also identified several boundary conditions, mainly due to the penetration of tree roots into rock joints and consequent destabilisation, and water infiltration into the rock discontinuities and consequent slope failures. finally, conservation interventions should take into account possible aesthetic impacts on the site. 3.3 cultural approach (in a broad sense) this approach concerns the dialogue and cultural integration between humanistic and scientific disciplines. for example, one can refer to the relationships between construction, degradation and restoration of an architectonic site and the provenance, characteristics and deterioration proneness of the materials used for its construction, also in terms of culturally oriented upgrading policies. more in general, a response should be given to the ever-felt need for a “neo-humanistic” culture, that is for the unity of culture (panizza, 1989a). an example of this is offered by the investigations carried out on the paving of the historical centre of modena (comune – università di modena, 1999), which could be the starting point for a cultural, educational and tourist path. at first, the petrographic nature of the material (e.g., a marble slab or the use of cobbles from different rock types) is examined, by observing its mineralogical characteristics and going back to the area of provenance (for example: a quarry of “ammonitico rosso” in the verona hills for the marble slab; the geomorphological evolution for the cobblestones: from an apennine mountain down to the valley through erosion, fluvial transportation and sedimentation processes). subsequently, the methods of extraction and transport of the materials would be considered, as well as the epoch of these operations and the laying down of the paving. furthermore, the historical, social and cultural motivations for the choice of this type of material would be illustrated, as well as its state of conservation and the causes of possible disarray processes. regarding this, in a chapter of the previously quoted investigation (bertolani et al., 1999), it is pointed out that the state of conservation of the sidewalks in modena depends not only on the resistance of the material used or on the method used for its laying down but also on exceptional events. for example, in the last period of world war 2 street-paving in modena underwent very serious damage owing to the passage and parking of heavy military vehicles of the nazi forces. as regards modern paving interventions on some streets, where cobblestones are used, the construction of a central lane made of rock slabs or concrete would be advisable for the benefit of cyclists; this would in fact avoid unpleasant jerks or the improper use of sidewalks by cyclists (panizza, 2003). finally, we would like to quote the recovery for tourist-cultural purposes of a military fortress built by the soldiers of the italian alpine regiments during the first world war. this appraisal operation was carried out by the well-known mountain climber r. messner, who transformed this stronghold into a “museum amidst the clouds”, the highest in europe, located on mt. rite, at an altitude of 2100 m in the italian dolomites, between cortina d’ampezzo and pieve di cadore (fig. 4). here, reality and representation are intertwined. reality is embodied by the “pale mountains”, with their mythical names such as pelmo, civetta, marmolada, cristallo and tofane, which surround the fortress and break into the space of the museum through small wingeomorphosites: a bridge between ... fig. 3 balzi rossi (red cliffs), near ventimiglia, in the western ligurian coast: cave with prehistoric settlements corresponding to various palaeolithic levels. balzi rossi (red cliffs), vicino ventimiglia, nella riviera ligure di ponente: grotta con insediamenti preistorici di vari livelli del paleolitico. 8 dows. representation is given by the evocative collection of paintings of the dolomites, among which the watercolours of the english painter e.t. compton (1849-1921) stand out, together with many other objects and materials belonging to the history and myths of these mountains. the way to the fortress is an old military track readapted for the use of hikers and closed to motorised traffic, which starts from the xvi century village of cibiana, a small “jewel” of cadore, still showing its original plan and made cheerful by over f ifty coloured, lively murals. 4. artistic suggestion there is no region, no place without natural features, among which the geomorphological aspects, in particular, make a landscape significant, unique for its landforms and the suggestions it conjures up. the features of the landscape are a sort of writing traced on the earth’s surface, an unpublished alphabet, used and reinterpreted by poets and artists who through their sensitivity can convey emotions to the onlookers. on the basis of these observations, a geologicalliterary itinerary was created starting from the assumption of the existence of specific emilia-romagna poetics and culture, linked to the outstanding morphological and geological features of our territory (bertacchini et al., 2002a). each geosite, with its description, has been combined with a literary passage by an author expressing atmospheres and identities of particular sites, further enhanced by the photographs of a great emilian master of the camera lens like franco fontana. this geological-literary itinerary was organised as a sort of guide for a sightseer yearning to meet nature also in its poetical forms by travelling in space and time. this can take place only through the awareness that nature can acquire a value for man only if the latter finds a way to go through the complete range of his/her senses, including those most specifically spiritual. at present, another research project is in progress: it consists of the study of some natural scenes from an artistic and geomorphological viewpoint, describing landscapes which. this approach aims to identify in the landscape the natural features which were painted in a picture. therefore, an art critic will carry out a detailed research on the painting whereas a geomorphologist will study and describe the landforms of the real landscape. it is by now evident that also science can offer itineraries of contemplation and aesthetic emotions which, although different, can be compared to those of the artists. the triggering of emotions comparable to the famous “stendhal’s syndrome” is not rare when particularly sensitive souls admire landscapes rich in specific suggestions. rañada (2003), in his recent book “the one thousand faces of science”, says: “nature shines with different lights and things sing in diverse ways many different songs. artists, poets and philosophers can perceive some of them, whereas scientists can perceive others”. references bertacchini m., giusti c., marchetti m., panizza m. & pellegrini m. (eds.) (1999) i beni geologici della provincia di modena artioli editore, modena, 104 pp. bertacchini m., coratza p. & piacente s. (2002a) la memoria della terra, la terra della memoria. censimento, valutazione e valorizzazione dei beni geologici in emilia romagna cd-rom, univ. modena e reggio e., dip. sc. della terra, regione emilia-romagna, serv. valorizzazione e tutela del paesaggio. ed. l’inchiostroblu, bologna. bertacchini m., coratza p. & piacente s. (2002b) le "pietre del diavolo" tra borghi e castell i nell’appennino emiliano un percorso culturale e didattico nel paesaggio ofiolitico in: a. saccani (ed.), atti del convegno nazionale “le ofioliti: isole sulla terraferma. per una rete di aree protette”, regione emilia-romagna, comune di fornovo taro, comune di terenzo, comunità montana valli taro e ceno, pp. 239-250. bertacchini m., coratza p. & piacente s. (2002c) paesaggi culturali geologia e letteratura nel novecento in emilia romagna regione emilia romagna, servizio tutela del paesaggio, l’inchiostroblu ed. bologna, 137 pp. bertolani m., loschi ghittoni a.g. & guidetti violi l. (1999) pietre (più o meno) preziose dei marciam. panizza & s. piacente fig. 4 “museum amidst the clouds“, military fortress from world war 1, located on mt. rite, at an altitude of 2100 m in the eastern dolomites. “museo nelle nuvole“, fortezza militare della prima guerra mondiale, situato sul mt. rite, 2100 m, nelle dolomiti orientali. piedi modenesi in: comune e università di modena (eds), un tesoro di marciapiedi, nuovagrafica, carpi (mo). carton a., cavallin a., francavilla f., mantovani f., panizza m., pellegrini g.b. & tellini c. with the collaboration of bini a., castaldini d., giorgi g., floris b., marchetti m., soldati m. & surian n. (1994) ricerche ambientali per l’individuazione e la valutazione dei beni geomorfologici. metodi ed esempi il quaternario, 7(1b), pp. 365-372. carton a. & panizza m. (eds.) (1991) itinerario n. 4 rifugio val parola settsass castello di andraz. itinerario n. s. vito di cadore rif. s. marco cadin del doge somadida (auronzo) nuove edizioni dolomiti s.r.l., pieve d’alpago belluno, 190 pp. castaldini d., piacente s., ghiddi e. & vaccari f. (1997) i beni geomorfologici: esempi di valutazione e di rappresentazione cartografica in un’area collinare della provincia di modena in: m. mautone (ed.), giornata di studio in onore di mario fondi. scritti geografici. alfredo guida editore, napoli, pp. 4156. comune & università di modena (1999) un tesoro di marciapiedi nuovagrafica, carpi (modena). cotecchia v., monterisi l. & rana s. (2000) condizioni di stabilità e interventi di consolidamento del tratto di collina dei templi di agrigento in corrispondenza del tempio di giunone lacinia atti conv. “condizionamenti geologici e geotecnici nella conservazione del patrimonio storicoculturale”, cnr gndci, 2133 pp. margottini c. (2002) la stabilità geologica della parete rocciosa contenente l’insediamento rupestre e gli affreschi romanici del ss. salvatore (vallerano vt) enea, roma. panizza m. (1988) beni morfologici e tutela ibc, fasc.1/2, pp. 73-74. panizza m. (1989a) beni "geologici" e cultura del paesaggio atti conv. intern. accad. naz. lincei., 2628/6/1989, pp. 85-86. panizza m. (1989b) beni "geologici" e cultura del paesaggio atti conv. int. "le concezioni attualistiche a due secoli dalla “theory of the earth” di j. hutton. riflessioni su fondamenti e storia delle scienze della terra", roma 26-27-28 giugno 1989, pp. 85-86. panizza m. (1990a) beni geomorfologici nel bacino del fiume panaro in: f. serafini & a. manicardi (eds.), il sistema fluviale scoltenna/panaro: storie d'acque e di uomini. amministrazione comunale di nonantola, pp. 49-54. panizza m. (1990b) dolomiti: risorsa naturale e cultura ambientale in: m. ercolani (ed.), montagna avventura 2000. urss e occidente tradizioni e traguardi a confonto. regione toscana, pp. 7576. panizza m. (1990c) il fascino e le vicende della storia geomorfologica delle dolomiti in: le dolomiti. un patrimonio da tutelare e amministrare . comunità montana agordina, pp. 19-31. panizza m. (1992a) geomorfologia pitagora editrice, bologna, 397 pp. panizza m. (1992b) sulla valutazione dei beni ambientali mem. descr. carta geol. d’it., 42, pp. 479484. panizza m. (2001) geomorphosites: concepts, methods and examples of geomorphological survey chinese science bulletin, 46, pp. 4-6. panizza m. (2003) i geomorfositi in un paesaggio culturale integrato in: s. piacente & g. poli (eds.), la memoria della terra, la terra della memoria. università degli studi di modena e reggio emilia regione emilia-romagna edizioni l'inchiostroblu, bologna, pp. 23-27. panizza m. & piacente s. (1991) relations between cultural resources and the natural environment in: n.s. baer, c. sabbioni & a.i. sors (eds.), proceedings of the european symposium: “ scince, technology and european cultural heritage”, bologna, 13-16 june 1989. butterworth-heinemann ltd., oxford, pp. 787793. panizza m. & piacente s. (1993) geomorphological assets evaluation z. geomorph. n. f., suppl. bd. 87, pp. 13-18. panizza m. & piacente s. (1999a) conoscenza geologica e gestione dei beni architettonici atti del convegno internazionale "archeologia e ambiente". ferrara, 3-4 aprile 1998. istituto per i beni artitstici, culturali, naturali della regione emilia romagna, a.b.a.c.o. edizioni, forlì, pp. 185-190. panizza m. & piacente s. (1999b) le forze della natura generatrici dei paesaggi e dell'aspetto del pianeta in: g. poli (ed.), geositi testimoni del tempo. regione emilia-romagna, bologna, pp. 28-29. panizza m. & piacente s. (1999c) il concetto di "bene" nel paesaggio fisico in: m. bertacchini, c. giusti, m. marchetti, m. panizza & m. pellegrini (eds.), i beni geologici della provincia di modena. artioli editore, modena, pp. 8. panizza m. & piacente s. (1999d) i beni di tipo geomorfologico in: m. bertacchini, c. giusti, m. marchetti, m. panizza & m. pellegrini (eds.), i beni geologici della provincia di modena. artioli editore, modena, pp. 21-45. panizza m. & piacente s. (2000) relazioni tra scienze della terra e patrimonio storico-archeologico in: g. lollino (ed.), condizionamenti geologici e geotecnici nella conservazione del patrimonio storico culturale. atti convegno geoben 2000, torino 7-9giugno 2000. pubbl. gndci n. 2133, pp. 723-730. panizza m. & piacente s. (2001) paesaggi in aula i.b.c., bologna, 9, 2, pp. 45-46. panizza, m. & piacente, s. (2003) geomorfologia culturale pitagora editrice, bologna, 350 pp. panizza m. & spampani m. (eds.) (1988) introduzione all’ambiente naturale e itinerario n. 1 passo giau mondeval croda da lago cortina. edizioni dolomiti, san vito di cadore belluno, 167 pp. panizza m., pellegrini m. & pozzi m. (1993) criteri geologici di costruzione della strada ducale estense da modena a massa del secolo xviii in: m. boriani e a. cazzani (eds.), le strade storiche un patrimonio da salvare, guerini e ass. ed., milano, pp. 79-84. piacente s. (1989) la conoscenza dell'ambiente per una sua tutela dinamica: due esempi nel9geomorphosites: a bridge between ... l'appennino modenese in: a. di blasi (ed.), l'italia che cambia. il contributo della geografia, vol. ii, pp. 499-504. piacente s. (1999a) sensibilità geologica e consenso sociale mem. descr. carta geol. d’it. 54, pp. 451-454. piacente s. (1999b) la conoscenza scientifica, un valore aggiunto in: g. poli (ed.), geositi testimoni del tempo, regione emilia romagna, pp. 234-244. piacente s. (2003) la memoria della terra, la terra della memoria in s. piacente & g. poli (eds), la memoria della terra, la terra della memoria, l’inchiostroblu, bologna, pp. 15-24. piacente s. & soldati m. (1989) i mulini dell'alta valle del panaro: un'occasione di analisi integrata per la conoscenza dell'appennino modenese prov. di modena, provv. agli studi e italia nostra, 131 pp. piacente s. & giusti c. (2000) geotopos, una oportunidad para la difusion y valoracion de la cultura geologica regional in: f.j. barba regidor & j. saiz de omeñaca gonzález (eds.), documentos del xi simposio sobre la enseñanza de la geología, 11-15 september 2000, universidad de cantabria, santander, pp. 134-137. piacente s. & poli g. (2003) la memoria della terra, la terra della memoria l’inchiostroblu, bologna, 159 pp. piacente s., bertacchini m. & coratza p. (2001) la cartografia come strumento di percezione e di gestione dinamica dei beni geologici in: g. scanu (ed.), cultura cartografica e culture del territorio atti del convegno nazionale (sassari 12-13 dicembre 2000) , bollettino della associazione italiana di cartografia, 111-112-113, pp. 401-407. piacente s., bertacchini m. & coratza p. (2003) geomorphological tourism amidst nature and culture: examples from emilia-romagna (italy) in: e. reynard, c. holzmann, d. guex & n. summermatter (eds.), géomorphologie et tourisme, actes de la réunion annuelle de la société suisse de géomorphologie (ssgm), finhaut, 21-23 septembre 2001, institut de géographie de l'université de lausanne (igul), pp. 145-155. rañada a. f. (2003) i mille volti della scienza. cultura scientifica e umanistica nella società contemporanea edizioni dedalo, 224 pp. secchi b. (2001) la città contemporanea e il suo progetto convegno "lezioni di storia urbana", assessorato alla cultura, comune di modena, nov.-dic. 2001, modena, pp. 13-17. 10 m. panizza & s. piacente imp. fusco-riccilucchi ssttoorriiaa ppaalleeoovveeggeettaazziioonnaallee ttaarrddiiggllaacciiaallee--oolloocceenniiccaa nneellll’’aarreeaa ddeell mmaarr ddii mmaarrmmaarraa oorriieennttaallee ffaabbiioo ffuussccoo11 && mmaarriiaannnnaa rriiccccii lluucccchhii11 1dipartimento di scienze della terra e geologico-ambientali, università di bologna, v. zamboni 67, 40127 bologna. (e-mail: fusco@geomin.unibo.it, marianna@geomin.unibo.it) abstract: fusco f. & ricci lucchi m., lateglacial to holocene palaeovegetation changes in eastern marmara sea area (it issn 0394 – 3356, 2004). the history of the vegetation throughout the lateglacial and the holocene is outlined by means of pollen analysis carried out on a core from the eastern marmara sea. six pollen assemblage zones, indicating peculiar vegetation features, have been distinguished and interpreted as the vegetation response to climatic changes. during lateglacial interstadial and younger dryas (corresponding to the lower three zones), only herbaceous and shrubby communities, dominated by artemisia, developed under cold and dry climate conditions. a slight forest expansion characterizes the lower pollen assemblage zone representing the lateglacial interstadial. forest development characterizes the upper three pollen zones and is indicated by both the expansion of arboreal pollen taxa (ap) and increase of pollen concentration. this change is radiocarbon dated to 10,650±40 bp, and is interpreted as the vegetation response to the onset of interglacial climate conditions at the beginning of the holocene. particularly, the first forest phase is characterized by the marked expansion of a mixed deciduous oak forest, which is replaced by a mixed pine-oak forest. the increase of pinus marks the beginning of the mediterranean climate phase. cultivated arboreal taxa (i.e., juglans, castanea, olea and vitis) spread during the upper pollen zone due to human activities. riassunto: fusco f. & ricci lucchi m., storia paleovegetazionale tardiglaciale-olocenica nell’area del mar di marmara orientale. (it issn 0394 – 3356, 2004). viene ricostruita la storia della vegetazione nel tardiglaciale e nell’olocene attraverso l’analisi pollinica di un sondaggio eseguito nel mar di marmara orientale. sono state riconosciute sei zone polliniche corrispondenti a sei differenti fasi vegetazionali, ognuna con proprie caratteristiche di fisionomia e composizione come risposta a peculiari condizioni climatiche. le prime tre comprendono parte dell’oscillazione interstadiale tardiglaciale e il dryas recente e sono caratterizzate da formazioni erbaceo-arbustive dominate da artemisia indicanti un clima generalmente freddo e arido. successivamente si osserva un mutamento molto marcato nella composizione e nella struttura della vegetazione con lo sviluppo di foreste in seguito all’instaurarsi di condizioni climatiche interglaciali. questo cambiamento è datato con un’analisi al radiocarbonio a 10.650±40 anni fa. all’interno dell’olocene si distinguono tre fasi forestali dominate, dapprima, solo da latifoglie decidue (in particolare quercus) e, poi, in associazione con pinus. l’espansione dei pini testimonia un cambiamento nella distribuzione annuale delle precipitazioni in senso mediterraneo. l’ultima fase forestale è caratterizzata dalla diffusione del castagno, dell’olivo, del noce e della vite dovuta presumibilmente all’attività dell’uomo. keywords: palynology, vegetation, lateglacial, holocene, marmara sea parole chiave: palinologia, vegetazione, tardiglaciale, olocene, mar di marmara. il quaternario italian journal of quaternary sciences 1177(1), 2004, 55-61 11.. iinnttrroodduuzziioonnee la ricostruzione della storia vegetazionale del tardo quaternario si basa principalmente sulle analisi palinologiche. in particolare, lo studio del polline fossile in sedimenti marini offre un quadro molto utile perché rispecchia le caratteristiche della vegetazione nelle regioni circostanti il mare, soprattutto dove scarseggiano lunghe e adeguate serie polliniche continentali come l’area adiacente il mar di marmara. lo scopo di questo lavoro è quello di studiare nel dettaglio la storia tardoquaternaria della vegetazione in un’area dalle caratteristiche climatiche peculiari. il mar di marmara, infatti, un piccolo bacino semichiuso nel mediterraneo orientale, si trova interposto tra la fascia delle steppe aride a sud-est e quella delle foreste temperate a nord-ovest, risentendo della loro reciproca vicinanza in relazione alle diverse modificazioni climatiche. esistono pochi studi palinologici di dettaglio in questa zona. koreneva (1971) ha studiato una carota non datata nel mar di marmara occidentale mentre, in un lavoro più recente (mudie et al., 2002), sono state analizzate cinque carote del mar di marmara di età compresa tra 33.500 e 1990 anni fa e una carota del mar nero di età olocenica, mediante le quali viene ricostruita la storia vegetazionale del corridoio mar nero-mar egeo dal pleniglaciale al presente. nel presente lavoro sono riportati i risultati di uno studio palinologico eseguito su una carota prelevata all’imbocco del golfo di i̇zmit a una profondità di -152,6 m, durante una crociera oceanografica organizzata dall’istituto di scienze marine del cnr di bologna. sulla stessa carota sono stati effettuati studi micropaleontologici (foraminiferi e ostracodi), sedimentologici e malacologici i cui risultati sono oggetto di un articolo in preparazione. su frammenti conchigliari rinvenuti all’interno di un intervallo sabbioso alla profondità di 262 cm è stata eseguita una datazione al 14c mediante spettrometria di massa con acceleratore (ams) che ha restituito l’età non calibrata di 10.650±40 anni (c. mchugh, 2002, com. pers.). 56 f. fusco & m. ricci lucchi 22.. llaa vveeggeettaazziioonnee ee iill cclliimmaa aattttuuaallii nel settore orientale del mar di marmara si osservano rilievi che vanno da circa 700 m slm fino a 1600 m slm. il clima attuale è di tipo mediterraneo ma varia in relazione alla distribuzione dei rilievi geografici, passando da zone costiere relativamente umide a zone più interne semiaride. la vegetazione può essere suddivisa in due tipi principali distribuiti per fasce altitudinali (zohary, 1973; roberts & wright, 1993): i) una foresta costiera eu-mediterranea che si spinge fino alla fascia collinare, composta prevalentemente da quercus ilex, q. coccifera, pinus halepensis, p. brutia, olea oleaster var. europea, pistacia lentiscus, con sottobosco ricco di elementi erbacei; le precipitazioni, prevalentemente invernali, variano da circa 300 mm/a a circa 1000 mm/a e la stagione estiva risulta secca; ii) una foresta decidua mesofila a carattere eusinico, in cui gli alberi dominanti sono i faggi, le querce decidue e i pini. le precipitazioni sono distribuite regolarmente nel corso dell’anno con una media superiore ai 600 mm/a. più a est, verso la turchia centrale, si assiste a una graduale transizione verso le steppe aride anatoliche, cioè una vegetazione quasi priva di alberi dominata da artemisia e piante erbacee come asteraceae, poaceae e chenopodiaceae, con le precipitazioni concentrate soprattutto in inverno e mai superiori a 300 mm/a. la zona di transizione verso queste steppe è occupata da una forestasteppa con alberi e arbusti sparsi e precipitazioni comprese tra 300-600 mm/a, concentrate soprattutto d’inverno. 33.. mmaatteerriiaallii ee mmeettooddii la litologia della carota im-5 consiste di peliti grigiastre, a tratti intervallate da livell i mill imetrici più sabbiosi, e interrotte nella porzione inferiore da un livello centrimetrico di sabbie conchigliari. al di sotto di questo livello, le peliti sono organiche e laminate, con alcuni livelli conchigliari, mentre quelle sovrastanti appaiono massive e più povere in sostanza organica. sono stati analizzati 39 campioni, trattati seguendo il metodo di laboratorio classico (cf. faegri & iversen, 1989; moore et al., 1991), che consiste in attacchi con hcl 20%, hf 40%, e koh 10%. per la stima delle concentrazioni polliniche è stato utilizzato il metodo di stockmarr (1971) che prevede l’aggiunta di una pasticca con un numero noto di spore di lycopodium sp. all’inizio del trattamento in ogni campione. vengono qui presentati il diagramma pollinico percentuale di dettaglio (fig. 2), il diagramma per gruppi di taxa ad affinità ecologiche e climatiche (fig. 3), il diagramma pollinico sintetico per alberi-pinus-arbusti-erbacee-igro/idrofite assieme a quello delle concentrazioni totali (fig. 4). 44.. ddiiaaggrraammmmii ppoolllliinniiccii i risultati delle analisi palinologiche hanno permesso di definire 6 zone polliniche numerate dal basso verso l’alto dalla im5-1 alla im5-6 (fig. 2 e fig. 3). zona im5-1. la zona è caratterizzata dalla dominanza di piante non-arboree (nap) e da concentrazioni polliniche basse (intorno ai 6000 granuli/g in media). tra gli alberi, si nota un’espansione delle latifoglie (soprattutto di quercus che raggiunge il 30%) e contemporaneamente una riduzione di pinus. zona im5-2. la zona presenta una marcata riduzione delle latifoglie arboree ed è carattizzata dalla dominanza di artemisia (che qui raggiunge percentuali del 50%) accompagnata da un’espansione di pinus e juniperus. zona im5-3. la zona si differenzia dalle precedenti per il calo di artemisia, la marcata espansione delle poaceae e il picco del t. sparganium. tra gli alberi, si osserva un fig. 1 ubicazione del sondaggio im-5. location of the core im-5. 57storia paleovegetazionale tardiglaciale-olocenica ... f ig . 2 d ia gr am m a po lli ni co p er ce nt ua le d ei p rin ci pa li ta xa d el s on da gg io im -5 . p ol le n pe rc en ta ge d ia gr am o f s el ec te d ta xa fo r th e co re im -5 . 58 calo di pinus e un moderato aumento delle latifoglie, soprattutto di salix e alnus. le concentrazioni polliniche totali restano ancora basse (attorno agli 8000 granuli/g). zona im5-4. la caratteristica più evidente è la marcata espansione di quercus accompagnata dall’incremento delle altre latifoglie del querceto misto come corylus, carpinus t. betulus, tilia, ulmus, quercus t. ilex-coccifera. si osserva, inoltre, l’espansione di fagus. gli elementi non-arborei subiscono una forte riduzione (da circa il 60% della zona precedente a circa il 20% in media). le concentrazioni polliniche registrano un marcato aumento (fino a circa 80.000 granuli/g), ad eccezione della parte basale della zona dove restano ancora basse. zona im5-5. la zona è caratterizzata da una nuova espansione di pinus e una concomitante riduzione di quercus. parallelamente si osserva anche un calo progressivo delle concentrazioni pollinche totali. zona im5-6. questa zona si distingue dalla precedente per l’aumento percentuale di piante legnose coltivate come olea, juglans e castanea. continua l’espansione di pinus e la riduzione di quercus. le concentrazioni sono basse, di poco superiori agli 8000 granuli/g in media. 55.. ddiissccuussssiioonnee e’ possibile suddividere il diagramma pollinico in due porzioni, ognuna comprendente tre biozone. la porzione inferiore è caratterizzata dalla dominanza di elementi non-arborei e da concentrazioni polliniche basse (fig. 4), che indicano un paesaggio non forestato a praterie e steppe. all’interno di questo paesaggio però, si osserva una significativa espansione forestale (im51) a cui segue lo sviluppo di una steppa arbustiva (im5-2) e infine il passaggio a un ambiente più umido indicato dall’espansione delle poaceae e degli elementi acquatici (im5-3). la porzione superiore mostra, invece, la prevalenza degli elementi arborei sulle comunità erbaceo-arbustive con concentrazioni polliniche elevate, testimoniando lo sviluppo di formazioni forestali. in particolare (fig. 4), inizialmente si sviluppa il querceto misto, mentre in seguito esso si riduce per l’espansione di pinus. nell’ultima zona pollinica, la im5-6, tale contrapposizione si accentua e si nota anche l’espansione delle piante legnose coltivate (juglans, castanea, olea, vitis) la cui curva diventa continua. la transizione dalle steppe alle foreste avviene poco più di 10.000 anni fa, cioè all’inizio dell’olocene. le formazioni steppiche delle zone im5-2 e im5-3 sono determinate dalle condizioni climatiche fredde ed aride che si verificarono in europa e nel medio oriente durante il dryas recente. a quel tempo, infatti, in tutta l’area mediterranea orientale e in anatolia si diffusero steppe fredde e aride a dominanza di chenopodiaceae, artemisia, asteraceae e poaceae (bottema, 1995), molto simili per composizione alle steppe delle zone im5-2 e im5-3, come evidenziato anche in altre carote del mar di marmara (mudie et al., 2002; caner e algan, 2002). la modesta ma significativa espansione delle arboree nella zona im5-1 può essere riferita all’«oscillazione interstadiale tardiglaciale» (o complesso allerød/bølling), che segnò la prima ricolonizzazione forestale dopo l’acme glaciale. il passaggio dalle steppe alle foreste segna il drastico mutamento di clima verso condizioni calde e umide dovute all’interglaciale olocenico. il primo segnale di questa trasformazione viene registrato con la culminafig.3 diagramma pollinico sintetico e diagramma delle concentrazioni polliniche totali del sondaggio im-5. synthetic pollen diagram and total pollen concentration diagram for the core im-5. f. fusco & m. ricci lucchi 59 f ig . 4 d ia g ra m m a p o lli n ic o p e r g ru p p i se le zi o n a ti co sì c o m p o st i: q u e rc e tu m m ix tu m : a ce r, b ux us , c ar pi nu s t. be tu lu s, c . t. or ie nt al is , c or yl us , c or nu s cf . m as , f ra xi nu s, h ed er a, p hi lly re a, q ue rc us , q . t. ile xco cc ife ra , t ili a, u lm us , a ln us , s a li x; a lb e ri m o n ta n i: a b ie s, f ag us , p ic ea ; p ia nt e le gn os e co lti va te : c a st a n e a , ju g la n s, o le a , v it is ; a rb u s ti : b e tu la , c u p re s s a c e a e in d if f. , h ip p o p h a e , t. ju n ip e ru s; i g ro -i d ro fi te : c y p e ra ce a e , t. s p a rg a n iu m , l yt h ru m , m yr io p h yl lu m , c f. n ym p h a e a , p ot am og et on . p ol le n di ag ra m o f se le ct ed g ro up s. q ue rc et um m ix tu m : a ce r, b u xu s, c ar pi nu s be tu lu sty pe , c . or ie nt al is -t yp e , c o ry lu s, c o rn u s cf . m a s, f ra xi nu s, h ed er a, p hi lly re a, q ue rcu s, q . ile xco cc ife ra -t yp e , t ili a , u lm u s , a ln u s , s a li x ; m o u n ta in tr ee s: a bi es , f ag us , p ic ea ; c ul tiva te d w o o d y ta xa : c a s ta n e a , j u g la n s , o le a , v it is ; s h ru b s: b e tu la , c u p re ss a ce a e u n in d if f. , h ip po ph ae , ju ni pe ru sty pe ; h yg ro hy dr op hy te s: c yp er ac ea e, s pa rg ani um -t yp e, l yt hr um , m yr io ph yl lu m , cf . n ym ph ae a, p ot am og et on . storia paleovegetazionale tardiglaciale-olocenica ... 60 zione delle piante acquatiche durante l’inizio della ricolonizzazione forestale. la comparsa di specchi d’acqua non effimeri era dovuta probabilmente all’aumento della piovosità o alla deglaciazione. l’espansione del querceto misto (im5-4) indica l’ulteriore aumento dell’umidità e della temperatura. si espandono e si affermano anche gli elementi montani, si raggiunge la massima copertura forestale (indicata dall’aumento delle concentrazioni polliniche) e la vegetazione si organizza in fasce altitudinali. i pini, presenti durante la fase più fredda e arida, ora sono quasi assenti. con la diffusione di pinus e la concomitante riduzione del querceto (zona im5-5), la vegetazione cambia di nuovo e assume una fisionomia molto simile all’attuale, probabilmente a causa di una riduzione e/o di una redistribuzione delle precipitazioni annuali verso un clima di tipo mediterraneo. questo è caratterizzato, infatti, dal forte calo delle precipitazioni nei mesi estivi, che determina la t ipica stagione secca. nel mediterraneo occidentale, tali condizioni si instaurarono nell’arco di alcuni millenni diffondendosi gradualmente in senso latitudinale da sud verso nord (jalut et al., 1997). più precisamente, il clima mediterraneo si stabilì a una latitudine di 39°-40°n circa 7000 anni fa, e raggiunse i 41°n solo attorno ai 5000 anni fa. se lo stesso andamento è valido anche per il mediterraneo orientale, alla latitudine del mar di marmara, compresa tra 40°n e 41°n, il clima mediterraneo potrebbe essersi instaurato attorno a 6000 anni fa. inoltre, nel periodo compreso tra 7000 e 5000 anni fa, si registra un aumento dell’aridità alle medie latitudini e un calo delle temperature nelle regioni polari (cf. steig, 1999, cum bibl.), mentre per l’europa i dati pollinici di numerosi siti attorno a 6000 anni fa evidenziano un aumento delle temperature (huntley & prentice, 1988), anche se i modelli climatici sono ancora contrastanti (cf. prentice et al., 1998). la curva degli alberi montani resta grosso modo invariata indicando che la fascia montana della vegetazione non subisce grandi modificazioni, mentre sono piuttosto le fasce altitudinali inferiori a risentire dei cambiamenti nel regime e nella distribuzione delle precipitazioni. la zona pollinica im5-6 registra l’intervento dell’uomo sul territorio per la diffusione di piante legnose coltivate. un’analoga diffusione delle piante coltivate si registra nella serie pollinica tardo-olocenica ricavata da un sondaggio eseguito nel lago manyas, nelle strette vicinanze del mar di marmara (leroy et al., 2002). nella turchia sud-occidentale, si assiste alla cosiddetta «fase dell’occupazione di beyşehir» (eastwood et al., 1999), durante la quale si affermano da un lato la pastorizia e dall’altro le colture cerealicole e arboricole, quest’ultime a juglans (noce), olea (olivo), castanea (castagno) e vitis (vite). questa fase iniziò circa 3000 anni fa ma conobbe la sua diffusione attorno ai 2600 anni fa, causando soprattutto una forte riduzione della copertura forestale a favore delle colture. essa terminò attorno al 700 d.c., quando i pini diventarono l’elemento forestale dominante. nella turchia nord-occidentale, la stessa fase di riduzione delle foreste dovuta all’azione dell’uomo iniziò invece 3500 anni fa (beug, 1967; bottema et al.., 1995; cf. mudie et al., 2002). analogamente, nel sondaggio im-5, l’espansione degli alberi coltivati è concomitante alla marcata diminuzione delle concentrazioni polliniche, il che potrebbe indicare una riduzione della copertura forestale. nella porzione sommitale del diagramma, pinus si afferma sopra tutti gli altri elementi. 66.. ccoonncclluussiioonnii la ricostruzione dell’evoluzione paleovegetazionale dell’area prospiciente il mar di marmara orientale ha messo in evidenza sia gli effetti e le caratteristiche delle principali oscillazioni climatiche avvenute dal tardiglaciale ad oggi, sia l’impatto delle attività umane sull’ambiente nel tardo olocene. la più importante modificazione climatica è quella avvenuta all’inizio dell’olocene con lo sviluppo di foreste temperate che hanno sostituito completamente le formazioni steppiche presenti precedentemente. queste foreste sono costituite inizialmente da latifoglie decidue a dominanza di querce che testimoniano il passaggio da un clima freddo e arido ad un clima temperato caldo-umido. successivamente, all’interno delle foreste, si osserva un’ulteriore modificazione con l’espansione di pinus e il conseguente ritiro del querceto misto mesofilo: il clima assume un carattere mediterraneo con relativo calo delle precipitazioni nel periodo estivo e un’accentuata stagionalità. infine, la storia della vegetazione e del clima negli ultimi millenni in questa regione documenta il crescente impatto dell’uomo sull’ambiente, evidenziato dallo sviluppo delle colture e dal conseguente calo della copertura vegetazionale. rriinnggrraazziiaammeennttii si ringrazia l’istituto di scienze marine del cnr di bologna per avere messo a disposizione il sondaggio im-5. lo studio è stato finanziato con fondi murst (40%) 2001 (coordinatore: f. massari). si ringraziano, inoltre, la prof. maria luisa colalongo e il prof. franco ricci lucchi per la lettura critica del lavoro, e i revisori per le preziose osservazioni al contenuto del manoscritto. bbiibblliiooggrraaffiiaa beug h.-j. (1967) contributions to the postglacial vegetational history of northern turkey quat. palaeoecol., 77, pp. 349-356. bottema s. (1995) the younger dryas in the eastern mediterranean quat. sc. rev., 1144 (9), pp. 883891. bottema s., woldring h. & aytyǧ b. (1995) late quaternary vegetation history of northern turkey paleohistoria, 1177, pp. 53-143. caner h. & algan o. (2002) palynology of sapropelic layers from the marmara sea marine geology, 119900, pp 35-46. eastwood w.j., roberts n., lamb h.f. & tibby j.c. (1999) holocene environmental change in southwest turkey: a palaeoecological record of lake and catchment-related changes quat. sc. rev., 1188 (4-5), pp. 671-695. faegri k. & iversen j. (1989) textbook of pollen analysis iv ed., john wiley & sons, chichester, 328 f. fusco & m. ricci lucchi pp. huntley b. & prentice c. (1988) july temperatures in europe from pollen data, 6000 years before present science, 224411, pp. 687-690. jalut g., esteban amat a., riera i mora s., fontugne m., mook r., bonnet l. & gauquelin t. (1997) holocene climatic changes in the western mediterranean: installation of the mediterranean climate c. r. acad. sc., paris, s. ii, 332255, pp. 327334. koreneva e.v. (1971) spores and pollen in mediterranean bottom sediments in: funnell b.m., riedel w.r. (eds.), the micropaleontology of the oceans. cambridge university press, cambridge, pp. 361-371. leroy s., kazancii n., i̇ lerii ö, kibar m., emre o., mcgee e. & griffiths h.i. (2002) abrupt environmental changes within a late holocene lacustrine sequence south of marmara sea (lake manyas, n-w turkey): possible links to seismic events marine geology, 119900, pp. 531-552. moore p.d., webb j.a. & collinson m.e. (1991) pollen analysis. ii ed., blackwell scientific publications, 276 pp. mudie p.j., rochon a. & aksu a.e. (2002) pollen stratigraphy of late quaternary cores from marmara sea: land-sea correlation and paleoclimatic history mar. geol., 119900, pp. 233-260. prentice i.c., harrison s.p., jolly d. & guiot j. (1998) the climate and biomes of europe at 6000 yr bp: comparison of model simulations and pollenbased reconstructions quat. sc. rev., 1177 (6-7), pp. 659-668. roberts n. & wright h.e.jr. (1993) vegetational, lake level, and climate history of the near east and southwest asia. in: wright h.e.jr., kutzbach j.e., webb iii, t. ruddiman, w.e., street-perrott f.a. & bartlein p. (eds.), global climate since the last glacial maximum. univ. of minnesota press, st. paul, mn, pp. 194-220. steig, e.j. (1999) mid-holocene climate change science, 228866,, pp. 1485-1486. stockmarr j. (1971) tablets with spores in absolute pollen analysis pollen et spores, 1133 (4), pp. 615621. zohary m. (1973) geobotanical foundations of the middle east. gustav fischer verlag ed., 2 voll., 739 pp. 61 ms. ricevuto l’11 novembre 2003 testo definitivo ricevuto il 2 marzo 2004 ms. received: november 11, 2003 final text received: march 2, 2004 storia paleovegetazionale tardiglaciale-olocenica ... imp.piccini& the italian register of natural hypogean geosites: a preliminary report leonardo piccini1,2, ugo sauro1,3, jo de waele1,4 & paolo mietto1,5 1società speleologica italiana, via zamboni 67 40123 bologna 2dipartimento di scienze della terra, università degli studi di firenze, via g. la pira, 4 – 50121, firenze; email: piccini@geo.unifi.it 3dipartimento di geografia, università degli studi di padova, ugo.sauro@unipd.it. 4dipartimento di scienze della terra, università degli studi di cagliari, geoam@unica.it. 5dipartimento di geologia, paleontologia e geofisica, università degli studi di padova, paolo.mietto@unipd.it. abstract: l. piccini et al., the italian register of natural hypogean geosites: a preliminary report. (it issn 0394-3356, 2005). since a couple of years, the italian speleological society (ssi) is carrying out a project for the realisation of a national inventory of hypogean natural geosites (geositi ipogei naturali = gin). a gin can be defined as "every subterranean natural void that represents exceptional naturalistic and/or cultural value, in the widest sense, in at least one of the following features: its intrinsic characteristics, its geological, geomorphologic or hydrogeological context, its morphodynamic significance, its content of hypogean landscape elements or significant materials or, finally, for the use man has made of it in time". the exceptionality mostly regards the scientific interest of the already performed or potential researches (global, european, national, regional or local relevance of the acquired or acquirable information), the historical and cultural interest and elements such as beauty, dimension, rarity, representativity and didactic or cultural interest. as a gin, entire cave complexes, single caves or single passages of caves can be chosen. five types of gin have been identified. gin for the intrinsic characteristics of the cave: concerns particularly well preserved parts of caves and their morphologies (erosion and corrosion forms), but also caves derived from particular speleogenetic processes (e.g. hyperkarst caves) or formed in special types of rock (e.g. gypsum caves). gin for the interest of the hosting karst area: in this type, caves with no special interest but representing important karst areas can be inserted. gin for the nature of the outcropping rocks: caves that allow a better understanding of petrography, mineralogy, tectonics, stratigraphy or palaeontology of the area. gin for the material contained in them: caves with scientifically important sediments, speleothems, evidences of palaeo-seismicity, palaeo-environmental indicators, archaeological or palaeontological deposits. gin for the importance in man's history: caves used by man in prehistory, but also the ones used more recently as places of cult, or caves important for the development of the speleological and karst explorations and studies. for all these types of gin, which can also coexist in the same site, the exceptional conditions of the phenomena have to be maintained, having different scales ranging from local up to global importance. a first list of italian gin has been compiled by a working group that has been instituted by the italian speleological society, composed of the regional responsibles of the cave registers and several experts. for every italian region no more than 1% of the total amount of natural caves has been identified as gin. in this paper a preliminary overview of some italian gin is given, reporting their names, distribution, type and importance. this provisional list already shows the exceptionality of the italian hypogean heritage on a european and global scale and these results encourage the working group to continue this research that aims for a better understanding and a growth of public awareness of this incredible speleological heritage. riassunto: l. piccini et al., il catasto italiano dei geositi ipogei naturai: risultati preliminari. (it issn 0394-3356, 2005). da alcuni anni la società speleologica italiana sta svolgendo un progetto, nato da un accordo con il servizio geologico nazionale (ora agenzia per la protezione dell’ambiente e per i servizi tecnici – apat), che ha come obiettivo il censimento dei geositi ipogei naturali (gin). sono da ritenere gin tutti quei vani sotterranei di origine naturale, le grotte per intenderci, che per le loro caratteristiche ambientali intrinseche, per i contesti geologici, geomorfologici e idrologici in cui si trovano, per il loro significato morfodinamico ed il loro contenuto d’elementi del paesaggio ipogeo, di materiali significativi o per l’uso che l’uomo ne ha fatto nel tempo, presentano caratteri di eccezionalità naturalistica e/o culturale in senso lato. l’eccezionalità riguarda soprattutto l’interesse scientifico delle ricerche già svolte o potenziali (rilevanza mondiale, europea, nazionale, regionale o locale dei dati acquisiti o acquisibili), l’interesse storico e culturale e i fattori di tipo estetico o dimensionale, di rarità, rappresentatività e interesse didattico-culturale. possono essere definiti gin interi complessi carsici, singole grotte oppure parti di esse. si distinguono cinque tipi di gin. gin per le caratteristiche intrinseche della grotta (ginci): comprende soprattutto cavità (o porzioni di esse) ben preservate con morfologie (forme d’erosione e/o di corrosione) e/o depositi di eccezionale importanza. in questa classe ricadono anche grotte dovute a processi genetici particolari (es. grotte ipercarsiche) oppure formate in rocce peculiari (es. grotte nei gessi). gin per l’interesse dell’area carsica in cui si trovano (ginac): comprende grotte rappresentative per aree carsiche di grande interesse. gin per la natura delle rocce affioranti (ginra): comprende quelle grotte che consentono di osservare le caratteristiche petrografiche, mineralogiche, tettoniche, stratigrafiche, paleontologiche delle rocce da esse attraversate, con un dettaglio e una ricchezza di informazioni non rilevabili all’esterno, in situazioni interessanti da un punto di vista strettamente geologico. gin per i materiali contenuti (ginmc): sono da considerare in questa categoria le cavità che contengono depositi fisici e/o chimici di particolare rilevanza scientifica. gin per l’uso da parte dell’uomo (ginan): rientrano in questa categoria le grotte che sono state utilizzate dall’uomo in tempi preistorici, storici o recenti a fini abitativi, di culto, di studio o altro. per ognuna di queste caratteristiche, che possono ovviamente anche coesistere, dovranno essere rispettate condizioni di eccezionalità dei fenomeni. tale eccezionalità può comunque spaziare da un contesto globale o continentale (gin di valore mondiale o europeo) a regionale o locale (gin di interesse nazionale, regionale e locale). e’ stata compilata una lista preliminare dei gin italiani da un gruppo di lavoro istituito dalla società speleologica italiana, composto dai responsabili regionali dei catasti delle grotte e da vari esperti. per ciascuna regione sono stati definiti come gin circa l’uno percento del totale numero di grotte censite a catasto. in questo lavoro è pubblicato un primo elenco di alcuni gin italiani, che mostra già da ora l’eccezionalità del patrimonio sotterraneo nazionale a livello europeo e mondiale, e questi risultati incoraggiano a proseguire questa ricerca, con l’obiettivo di aumentare le conoscenze e di sensibilizzare maggiormente l’opinione pubblica in modo da tutelare il nostro immenso patrimonio speleologico. keywords: caves, geosites, speleology, italy. parole chiave: grotte, geositi, speleologia, italia. il quaternario italian journal of quaternary sciences 18(1), 2005 volume speciale, 155-162 156 l. piccini et al. 1. introduction the italian speleological society (ssi) and the national geological service (sgn, now agency for the safeguard of environment and technical services apat) have stipulated an agreement for the identification of the hypogean natural geosites (gin) of italy. actually, the exact meaning of the word “geosite” is not yet clear. for some researchers the main characteristic of a geosite is to be enjoyable for tourism and cultural purposes (geo-tourism); in this case a geosite can be regarded as an important element in the framework of economic development of local communities. for other researchers the scientific elements are the most important ones, and thus the geosite becomes an object that has to be studied and protected (brancucci & burlando, 2001; sauro & grandgirard, 1997). enjoying natural caves becomes a secondary fact because not all caves are of easy access, and the tourist adaptation of these difficult environments normally collides with their protection needs. in many cases the cave itself represents a geological site sensu latu, mostly combined with its naturalistic, environmental and/or cultural interest. in the speleological sense a gin could be defined as follows: "every subterranean natural void that represents exceptional naturalistic and/or cultural value, in the widest sense, in at least one of the following features: its intrinsic environmental characteristics, its geological, geomorphologic or hydrogeological context, its morphodynamic significance, its content of hypogean landscape elements or significant materials or, finally, for the use man has made of it in time". the exceptionality mostly regards the scientific interest of the already performed or potential researches (global, european, national, regional or local importance of the acquired or acquirable information), the historical and cultural interest and elements such as beauty, dimension, rarity, representativity and didactic or cultural interest. 2. definitions the following categories of geological and geomorphologic sites can be classified as gin: karst systems (or cave complexes); single caves; more or less important portions of caves. rarely entire karst systems can be considered as gin for the difficulty of their delimitation and their description. in the framework of this work five types of gin have been defined. 1) gin for the intrinsic characteristics of the cave in this category, those caves that contain relevant elements and forms that acquire exceptionality for their quantity, quality, exemplarity, dimension or aesthetic value are considered. these characteristics concern particularly well-preserved parts of caves and their morphologies (erosion and corrosion forms). as examples can be mentioned: caves with extremely well developed phreatic tubes, impressive underground canyon passages, immense underground rooms, extremely well developed erosion or corrosion forms on the ceilings and walls etc. in this category caves derived from particular speleogenetic processes (e.g. hyperkarst caves, thermal caves) or formed in special types of rock (e.g. gypsum caves, conglomerate caves, etc.) are also inserted. the morphologic and speleogenetic aspects acquire particular importance when these are in relation with the evolution of the environment in its multiple aspects (geology, geomorphology, climate, biology etc.). 2) gin for the interest of the hosting karst area in this type, caves with no special interest but representative for important karst areas can be inserted. this category comprises caves that, if evaluated singularly would not be considered gin because of the lack of special interest, but considered on a local scale they become important elements if evaluated in their geomorphologic and environmental context. 3) gin for the nature of the outcropping rocks it regroups caves that allow a better understanding of petrography, mineralogy, tectonics, stratigraphy or palaeontology of the area. in fact, in certain areas, caves can allow a much better and more detailed study of geological sequences, their structure and their mineralogical and/or palaeontological content. especially vertical caves sometimes cross through thick sedimentary sequences, and rocks are sometimes very well exposed. 4) gin for the material contained in them caves are geological traps in which sediments and biological remains are extremely well preserved, enabling the understanding of past morphological, climatic and biological conditions. among the scientifically important deposits the physical (alluvial deposits, detritus infi l l ings, ancient loess-like sediments, palaeokarst deposits, etc.) and the chemical ones (speleothems, secondary minerals, etc.) can be mentioned, at the condition that they are of relevant importance for their characteristics (extension, dimension, representativity, aesthetic value, rareness, etc.) or for the indirect information that they can give on the evolution of the cave itself or of its environment (palaeo-climate, palaeo-geography, palaeo-seismicity, etc.). those caves that have enabled the reconstruction of past conditions thanks to their physical and/or chemical deposits are necessarily inserted in this category. also caves with important palaeontological, palaeo-ethnological or archaeological material refer to this class (fossil woods, guano deposits, prehistoric findings, important human fossils etc.) because these findings are also related to the favourable geomorphologic situation of the caves itself. finally, also those caves of particular biological interest can be inserted in this type of gin because both fossil fauna and flora (e.g. pollen) and cave dwelling fauna can represent testimonials of past biogeographical situations. 5) gin for the importance in man's history this category contains caves used by man in prehistory, but also the ones used more recently as places of cult (hermitage, palaeochristian rupestrian churches, etc.) or caves important for the development of the speleological and karst studies. for all these types of gin, that can also coexist, the uniqueness of the phenomena have to be maintained. this exceptionality can be defined in a global or continental (gin with a global or european value) up to a regional or local context (gin of national, regional or local interest). a single gin, in function also of its interest, can comprise an entire karst system (normally great cave systems with a complex evolution), entire caves for the presently known portions (in the case of caves with a peculiar genesis or the ones that allow a better understanding of geological sequences crossed by the cave itself, etc.) or only parts of caves (e.g. prehistoric and archaeological caves in which often only the entrance halls are of interest). 3. criteria for the definition of gin a first list of gin is now in progress, compiled simply relying on the personal knowledge of every single responsible of the regional cave registers, combined with the information given by local speleological experts. many situations are already well known and well documented even at a national level (piccini et al., 2001). a further selection can be derived from the interrogation of the cave register database (ferrari & piccini, 1996): the simple analysis for the longest and deepest caves, the altitude of the entrances (high mountain or submarine caves), the nature of the rocks (e.g. gypsum caves), the scientific interest (archaeology, biospeleology, mineralogy, etc.) or even the number of bibliographical references, can give rise to a reliable selection of possible gin. this list of “potential gin” needs of course further specific investigation to individuate the cases of real interest. for every region a first list of gin has thus been compiled, inserting the most important and interesting speleological sites, together with an essential reference list. following up every region will have to compile a list of potentially interesting sites that need a more appropriate and detailed study also in loco. for those sites that do not need any further examination a preliminary data base sheet, derived from the one used by the sgn (now apat), has been compiled. the characteristics of a gin are reported on a card which resemble that one proposed by the sgn and the centro documentazione geositi of the dipartimento polis università di genova. the recorded data concern localisation, fields of scientific interests, relevance valutation, description and bibliography. 4. some examples of gin in italy in this initial stage of cataloguing the working group instituted by the ital ian speleological society has already made a preliminary list of gin 157the italian register of ... distributed in several regions. for some of these sites a database sheet has already been compiled and the necessary fieldwork has confirmed its compatibility with the minimum criteria for its classification as a gin. hereunder some of these gin are briefly illustrated. 4.1 gin for the intrinsic characteristics of the cave monte corchia karst complex (caves register number of main entrances: 51, 52, 120, 741, t/lu; apuan alps, tuscany) the corchia cave is presently the longest cave in italy, being about 52 km long and 1195 m deep. the complex has 12 different entrances, from the top of the mountain, at 1637 m a.s.l., to the lower at 930 m a.s.l. (fig. 1). the morphologic setting of this exceptional karst system pertains to many interesting features of several points of view. anywhere, the most peculiar aspect probably concerns the relationship between morphological setting of cave passages and morphotectonic evolution (piccini, 1997). based on the vertical distribution of the phreatic and epiphreatic passages in the caves, four major generations of karst levels can be identified in the corchia complex. the first and most ancient generation lies above 1450 m a.s.l. and probably dates to late pliocene. the second level comprises more than 10 km of phreatic tubes located between 1000 and 1200 m a.s.l. the latter form a wide maze network that was subsequently affected by a major phase of vadose entrenchment. a recent dating (drysdale et al., 2001) suggests that also low levels passed from phreatic to vadose condition in the early pleistocene. the cave is also important for the in-filling deposits, with exotic pebbles related to an ancient hallogenic feeding (piccini, 1991). veja natural arch (caves register: 117, 465, 466, 467, 468 v/vr; monti lessini, venetia) the veja bridge, the most known natural arch in the monti lessini (venetian prealps), represents the remnant of the roof of a large cave chamber (fig. 2). this cavern collapsed mostly to form a karst window, a kind of collapse doline open downward, delimited by fig. 1 – the monte corchia karst complex. the sketch profile shows the vertical pattern of the cave emphasizing the morphological complexity and the policyclic evolution. 1) main cave entrances; 2) relict phreatic passages; 3) vadose passages. il complesso carsico del monte corchia. la sezione schematica mostra l’andamento verticale della grotta mostrandone la complessità morfologica e l’evoluzione policiclica. 1) ingressi principali; 2) condotti relitti d’origine freatica; 3) condotti d’origine vadosa. 158 rocky faces with several entrances of caverns (pasa, 1954; perna & sauro, 1976). this natural monument has been destination of field trips of the dwellers of the town of the po’ plain since middle ages. in 1496 the mantegna painted this bridge, as seen from the valley below and with the enrichment of some fantastic elements, in the camera degli sposi of the ducal palace of mantova. so this form represents one of the first natural monuments ever represented by an artist (mietto & sauro, 2000). from the point of view of its natural history the arch and the related caves are really interesting. the fillings of the karst cavities include very different materials as: a) very old soil sediments, probably of paleogene age, similar to those of the verona hills (latella & zorzin, 1989), b) basaltic lavas intruded inside karst galleries during late oligocene or early miocene (rossi & zorzin, 1993), c) pleistocene age fillings (pasa, 1950, bartolomei & broglio, 1975). the pleistocene age sediments are rich in palaeontological and archaeological remains that have been studied starting from the early xixth century. the presence of prehistoric man in the area is documented since lower palaeolithic. the geosite of veja bridge, which is now part of the natural regional park of the monti lessini, may be considered of global importance according to the coexistence of very different and relevant aspects. 4.2 gin for the interest of the hosting karst area spluga della preta cave (caves register: 1 v/vr; monti lessini, venetia) the spluga della preta in the monti lessini (venetian prealps) is one of the four earlyexplored deepest vertical cave systems in the world (fig. 3), with depths ranging, after the first campaigns, between 300 and 500 m. the early exploration of the preta took place in the years 1925, 1926 and 1927. due to the fact that the first explorers have overestimated the depth, this system was considered for nearly 30 years as the deepest cave in the world (stegagno, 1927; corrà, 1975; mietto & sauro, 2000). during more recent explorations the present bottom has been reached at the depth of 877 m (sauro et al., 1995). in the second half of the 20th century, its old fame attracted tens of expeditions from many different countries. for this reason the cave system was explored and studied and the great scientific importance of the cave itself and of the relative environment has been underl. piccini et al fig. 2 – the natural arc of ponte di veja, in the monti lessini karst area. l’arco naturale del ponte di veja, nell’area carsica dei monti lessini. fig. 3 a view from air of the summit plane of corno d’aquilio. the arrow indicates the entrance-doline of the spluga della preta cave (photo oca). veduta aerea del pianoro sommitale del corno d’aquilio. la freccia indica la dolina d’ingresso della spluga della preta (foto oca). 159 stood (maucci, 1954; sauro, 1974). the preta system is the result of a speleogenetic evolution occurred in a peculiar geological and geomorphologic environment. speleogenesis has been controlled by: a) the lithological sequence, characterised by a hanging aquifer hosted inside the dense network of fractures of a marly limestone (biancone), similar to the chalk, loosing water in the underlying pure limestone, b) the tectonic setting of the area (the cave system is inside a tectonic wedge evolving as a thrust structure), c) the deepening of the large lateral valley of the adige river, very near to the cave. the cave is also of great biological interest. it hosts endemic species of invertebrates discovered in this cave, and among these the largest cave carabid ever found in the world can be mentioned. the geosite of spluga della preta, which is now part of the natural regional park of the monti lessini, may be considered of global importance according to the coexistence of very different and relevant aspects. 4.3 gin for the nature of the outcropping rocks olivifer cave (caves register: 1000 t/lu; apuan alps, tuscany) this typical alpine-like karst system has a depth of 1215 and is one of the deepest caves in italy (fig. 4). the cave has two entrances and develops mainly in metadolomite of triassic age (carnian-norian) (piccini, 1992). the first part of the cave, until the depth of 900 m, follows the overturned stratigraphic contact between dolomitic marble (a heteropic facies of carrara marble) and dolomite. the cave allows an exceptional vision of this geologic passage that is fundamental in the comprehension of the evolution of the tuscan carbonate shelf at the passage between triassic and jurassic. being an active cave, the vertical passages show the petrographic and sedimentological features of the rocks with great detail and, despite the local intensive tectonic deformation, allow to reconstruct the phases of emersion that affected this part of the carbonate shelf. 4.4 gin for the material contained in them santa barbara cave (caves register: 210 sa/ca; iglesiente, sardinia) this cave, open to public since a couple of years, has been discovered in the early fifties during the excavations inside the san giovanni mine at iglesias and has no natural entrance (fig. 5). the importance of this small cave, that has a total development of only about 110 meters (fabbri & forti, 1981), is to be found in its geologic characteristics (forti & perna, 1981); it is probably one of the oldest caves in italy. the natural void has been formed in the l imestone of lower cambrian age and could be related to a triassic karst cycle. the big room is well decorated by great columns, attractive stalactites and stalagmites, while the roof and the walls are completely covered with barite crystals, certainly a rare mineral in the cave environment, testifying its complex genetic history (rossetti & zucchini, 1957; forti & perna, 1982). onice cave (caves register: 234 t/lu; apuan alps, tuscany) the onice cave is a typical example of cave affected by a long and almost continuous phase of chemical and physical in-fi l l ing, fol lowing the first phreatic enlarging phase. it consists of a 150 m long segment of a large phreatic the italian register of ... fig. 4 sketch geologic profile of olivifer cave: note the structure-controlled vertical pattern of the cave. 1) dolomitic marble, 2) phyllite lens, 3) shaly marble, 4) dolomite, 5) palaeozoic basement. (from: piccini, 1992). profilo schematico dell’abisso olivifer: si noti il controllo esercitato dalla struttura sull’andamento verticale della grotta. 1) marmi dolomitici; 2) lenti di filladi; 3) marmi scistosi; 4) dolomie; 5) basamento paleozoico. (da: piccini, 1992). 160 tube, which opens at 573 m a.s.l. along a secondary crest of the frigido basin, near to massa. this cave hosts a flowstone, at least 5 m thick that was quarried in the past for getting ornamental stone. the top bed of the flowstone has an age exceeding the limits of alpha u-th dating (>350 ka), thus, according to these data, we can assert that onice was active as a phreatic conduit in the middle pleistocene, probably before 500 ka bp (piccini et al., 2003). the flowstone is covered by an 8 m thick sediment made up of dolomitic fine sand, probably related to upper pleistocene cold periods characterized by mechanical denudation and removal of soils. the sediment, which shows a varve-like banding, is interlayered with datable calcite crusts. the flowstone, presently under investigation, offers the possibility to get a complete and medium-definition record of environmental changes during middle and late pleistocene. lamalunga cave (caves register: 1295 pu/ba; altamura, apulia) the cave, in the area of the murge of altamura, is made up of a tunnel, which extends not far beneath the surface. the morphologic setting suggests a long evolution from phreatic condition to a phase in which the cave turns into a vadose zone and then progressively undergoes a decrease in the water flow. the cave was then affected by collapsing and concretioning cycles over an unknown time period. it is during this last evolution phase that the palaeontological deposition occurs. the cave of lamalunga rose to the world attention in 1993 thanks to the discovery of a complete skeleton of an archaic man (forti, 1993). the skeleton of the now named man of altamura, is located in a lateral branch of the main gallery. the bones are almost completely covered by calcite, a stalagmitic formation covers part of the maxillary, leaving the supraorbital arch visible (fig. 6). the cranium morphology resembles that of the neanderthal type, and the characteristics of the skeleton indicate that the individual was an adult male. thanks to the completeness and exceptional state of preservation and to the presence of numerous elements of the almost complete post-cranial skeleton, the man of altamura represents one of the most surprising palaeontological discoveries ever made in italy and in europe. 4.5 gin for the importance in man's history la verna caves (caves register: 51and 600 t/ar; arezzo, tuscany) the la verna sanctuary is one of the most famous cult sites of catholic church in italy (vianelli, 1994). the sanctuary stays on a hanging cliff made up of calcareous sandstone lying on shale, of tertiary age. the l. piccini et al. fig. 5 – vertical and plan view of the santa barbara cave, (from: fabbri & forti, 1981). vista verticale ed in pianta della grotta di santa barbara, (da: fabbri & forti, 1981). fig. 6 the skeleton of the man of altamura, partially cemented by speleothems, (reprinted from: forti, 1993). lo scheletro dell’uomo di altamura, parzialmente inglobato da speleotemi, (ristampato da: forti, 1993). relief is affected by de-stressing fractures due to gravitative deformation, which led to the formation of trenches on the top surface and fissures at the base. the site is located along one of the main old ways crossing the northern apennines and thus it is since a long time a site of refuge for man. in may 1213, san francesco made the mountain a site for hermitage and pray. during the work for building the small church of santa maria degli angeli, san francesco and his friars found a refuge in small caves and niches, formed by rock collapses. the morphological relevance of these caves is minimal, but the geological setting, the particular genetic process of the caves and, moreover, the historical events, made this site one of the most important geomorphosites of the northern apennines. san giovanni cave (caves register: 81 sa/ca; iglesiente, sardinia) san giovanni cave is located near the little town of domusnovas in cagliari province, and is characterised by a natural tunnel that crosses monte acqua from north to south for a total length of more than 800 meters (fig. 7). this tunnel has been excavated by the sa duchessa river in the waxy limestone of the so-called "metallifero" (gonnesa group, lower cambrian) (de waele & pisano, 1998). the cave has a partially explored submerged branch from which rises a river with an average discharge of 100 l/s. in roman times this water was conveyed into an aqueduct that supplied cagliari until some decennia ago. known since prehistory, only in the last decades this cave was the subject of intense speleological exploration, bringing its development to about 5 km with the discovery of at least two fossil cave levels testifying a complex speleogenesis (bianco et al., 1992; papinuto & naseddu, 1996; naseddu, 1998). from an archaeological point of view, aside the already mentioned roman aqueduct, a big megalithic wall (ca. 1500 b.c.) is still clearly visible at the southern entrance (alba, 1982). the cave has a historical interest for the presence of a road that crosses the whole natural tunnel. since half the 19th century, in fact, this natural passage enabled horse-carts first, trucks later, to carry the pb and zn mineral mined in the sa duchessa valley and in the mountains to the cixerri valley where a railway brought the ore to the industrial plants or harbours. the cave has also great biospeleological interest, with the presence of an important bat colony and many species of arthropods, several of which are endemic and sometimes of great biogeographical importance (grafitti, 2002) 5. conclusions presently, about 50 gin have been preliminary selected by the working group in the whole italian territory, but we presume that the number of gin will be probably more than 300. for all these sites a sheet will be compiled that will enable the construction of a database. the preliminary data already show the great importance of the speleological heritage in italy, probably representing one of the most important of the european continent. many work is still to be done, such as the raise in public awareness of our important speleological geosites, their sustainable management and their protection where needed, in order to deliver our subterranean heritage to the future generations. 161the italian register of ... fig. 7 the lower entrance of san giovanni cave, close to domusnovas. l’entrata inferiore della grotta di san giovanni, presso domusnovas. acknowledgments a special thank to franco cucchi and paolo forti for their reviews. research supported by società speleologica italiana. references alba l. (1982) i depositi archeologici nelle grotte dell'iglesiente memorie istituto italiano di speleologia 1(1), pp. 35-42. bartolomei g. & broglio a. (1975) risultati preliminari delle nuove ricerche nei depositi quaternari della grotta a di veja boll. museo civ. st. nat. verona, 11, pp. 217-238. bianco l., chessa l., de waele j., naseddu a. & sanna f. (1992) le tentazioni di san giovanni speleologia, 26, pp. 16-21. brancucci g. & burlando m. (2001) la salvaguardia del patrimonio geologico franco angeli ed., 96 pp. corrà g. (1975) la spluga della preta, cinquant'anni di esplorazioni natura alpina, 3, pp. 1-239. de waele j. & pisano m. (1998) interazione fra attività mineraria ed un acquifero carsico: l'esempio di barraxiutta (domusnovas, sardegna sud-occidentale) in: crema & ferrarese (eds.), atti del convegno nazionale sull'inquinamento delle grotte e degli acquiferi carsici e possibili ricadute sulla collettività, ponte di brenta, 26-27 settembre 1998, pp. 195-209. drysdale r., bruschi g., fallick a.e-. heijnis h., isola i., roncioni a. & zanchetta g. (2001) primi dati cronologici ed isotopici di una stalagmite dell’antro del corchia sviluppata durante lo stage isotopico 7 (alpi apuane, italia) atti vii congr. fed. spel. tosc., pp. 99-101. fabbri m. & forti p. (1981) esplorazioni nell'iglesiente sottoterra, 59, pp. 31-35. ferrari g. & piccini l. (1996) the register of the italian caves atti ii° symposium progeo, roma 20-22 maggio 1996, mem descr. carta geol.d’ it., liv (1999), pp. 279-284. forti p. & perna g. (1981) la turisticizzazione della grotta di santa barbara nella miniera di san giovanni e la creazione di un museo minerario ad essa connesso (iglesias sardegna sud occidentale) le grotte d'italia, 4(10), pp. 181-187. forti p. (1993) il babbo del neanderthal abitava in puglia? speleologia, 29, pp. 6-7. forti p. & perna g. (1982) concrezioni e cristallizzazioni nei karst dell'iglesiente (sardegna sw) sottoterra, 63, pp. 39-48. grafitti g. (2002) la biospeleologia in sardegna. storia e prospettive in: j. de waele (ed.), atti del convegno di studio il carsismo e la ricerca speleologica in sardegna, cagliari 23-25 novembre 2001, anthèo, 6, pp. 269-298. latella l. & zorzin r. (1989) studi speleologici su una miniera di “terra gialla” di verona la lessinia ieri oggi domani: quaderno culturale 1999, pp. 47-52. maucci w. (1954) analisi morfogenetica della spluga della preta atti vi congresso naz. speleologia, trieste, 40 pp. mietto p. & sauro u. (2000) le grotte del veneto: paesaggi carsici e grotte del veneto regione del veneto la grafica editrice (vago di lavagno, verona), seconda edizione, 480 pp. naseddu a. (1998) san giovanni di domusnovas è più profonda: lo speleosub enrico saver raggiunge i 80 sardegna speleologica, 14, pp. 2-9. papinuto s. & naseddu a. (1996) grotta di s.giovanni "ramo bobore" speleologia, 35, pp. 57-63. pasa a. (1954) carsismo ed idrografia carsica del gruppo del monte baldo e dei lessini veronesi c.n.r., centro studi geogr. fis., ricerche sulla morfologia e idrografia carsica, 5, pp. 1-150. pasa a. (1950) i depositi quaternari del ponte di veja. parte i: geomorfologia; parte ii: la fauna mem. museo civ. st. nat. verona, 2, pp. 241-308. perna g. & sauro u. (1976) ponti naturali economia trentina, 4, pp. 29-36 piccini l. (1991) ipotesi sulla origine e sulla evoluzione del complesso carsico del monte corchia atti 6° congr. fed. spel. tosc., stazzema (lucca), 13 novembre 1991, pp. 59-82. piccini l. (1992) aspetti geologici e morfologici dell'abisso olivifer (m. grondilice alpi apuane) atti int. congr. "alpine caves: alpine karst system and their environmental context", asiago (vicenza), june 11-14 1992, pp. 313-320. piccini l. (1997) evolution of karst in the alpi apuane (italy): relationships with the morphotectonic history 4th int. conf. on geomorph., bologna, september 1997, suppl. geogr. fis. din. quat., iii, t. 4 (1998), pp. 21-31. piccini l., drysdale r. & heijnis h. (2003) karst caves morphology and sediments as indicators of the uplift history in the alpi apuane (tuscany, italy) workshop “uplift and erosion”, certosa di pontignano (siena), september 20 and 21, 2001. quaternary international, 101-102, pp. 219-227. piccini l., sauro u. & mietto p. (2001) il censimento dei geositi ipogei naturali atti conv. “geositi, tra tutela e valorizzazione della natura” carrara, ottobre, 2001, pp. 27-29. rossetti v. & zucchini a. (1957) baritina della grotta di santa barbara rendiconti seminario facoltà scienze università di cagliari, 26(3-4), pp. 240255. rossi g. & zorzin r. (1993) nuove osservazioni sul complesso carsico del ponte di veja (m.ti lessini vr) atti xvi congr. naz: speleol., udine 1990, le grotte d’italia, s.iv, xv, pp. 41-49. sauro u. (1974) aspetti dell'evoluzione carsica legata a particolari condizioni litologiche e tettoniche negli alti lessini boll. soc. geol. it., 93, pp. 945-969. sauro u. & grandgirad v. (1997) geotopes and their management: results of the discussion on "geotopes" proceedings 12th intern. congr. speleol., 1997, switzeland, v. 6, pp. 109-110. sauro u., menichetti m. & troncon g. (1995) "operazione corno d'aquilio": an example of cleaning operation, exploration and scientific analysis of a karst system acta carsologica, 24, pp. 487-499. stegagno g. (1927) l'abisso più profondo del mondo sinora esplorato l'esplorazione della spluga della preta. grotte d'italia, 1-2, pp. 21-34. vianelli m. (1994) la verna. il monte di san francesco ed. mv, bologna, 64 pp. 162 l. piccini et al microsoft word 00_indice_06lm.docx il quaternario it issn 039-3356 italian journal of quaternary sciences 24 (2), 2011 171-178 il cranio di stephanorhinus hemitoechus (falconer, 1859) di fosso malafede (vitinia, roma) con note sulla prima presenza della specie in italia luca pandolfi dipartimento di scienze della terra, università sapienza, roma dipartimento di scienze geologiche università degli studi roma tre, roma corresponding author: <lpandolfi@uniroma3.it> riassunto: l. pandolfi, il cranio di stephanorhinus hemitoechus (falconer, 1859) di fosso malafede (vitinia, roma) con note sulla prima presenza della specie in italia. in questo lavoro viene descritto un cranio di rinoceronte rinvenuto nei depositi fluviali nei pressi di fosso malafede (vitinia, roma, italia centrale) e conservato nel museo di paleontologia della sapienza, università di roma. l’analisi morfo-comparativa condotta sul cranio ha permesso di attribuire lo stesso alla specie stephanorhinus hemitoechus. il cranio presenta i caratteri tipici della specie, quali, una cresta occipitale relativamente molto sporgente verso l’indietro, la serie dentaria avanzata e l’incisura nasale arretrata. inoltre, sulla base dell’usura dentaria, il cranio viene riferito ad un individuo di età molto avanzata, di circa 30-36 anni. s. hemitoechus descritto per la prima volta in gran bretagna e segnalato in europa a partire dal mis14-13, sembra essere presente nella penisola solo dal tardo pleistocene medio (età a mammiferi aureliano: uf di torre in pietra). infatti, le segnalazioni relative al galeriano inferiore e medio sembrano quanto mai infondate, mentre quelle relative al galeriano superiore risultano al momento dubbie o poco attendibili. abstract: l. pandolfi, the skull of stephanorhinus hemitoechus (falconer, 1859) from fosso malafede (vitinia, rome) with notes on the first occurrence of the species in italy. in this work a well-preserved skull of rhinoceros is described. it has been discovered in the upper middle pleistocene fluvial deposits outcropping at fosso malafede (vitinia, rome, central italy) and it is preserved in the museum of paleontology in sapienza, university of rome. comparative analysis of the morphological characters allow to ascribed the skull to stephanorhinus hemitoechus. the specimen shows a well-developed occipital crest, toothrows shifted forward and an extended nasal groove. the degree of wear of the second and third upper molars suggests an about 30-36 year-old individual. s. hemitoechus has been named for the first time by falconer in 1859 from several remains discovered in great britain. this species is present at about 0.500-0.450 million years in continental europe and it is one of the components of the italian late middle and late pleistocene assemblages (aurelian mammal age). the early middle pleistocene remains from slivia, torrente stirone and ponte galeria which are ascribed here to s. hundsheimensis, had been previously assigned to s. hemitoechus. to the latter can be ascribed a mandible discovered in the tiber river terraces at monte verde, referred to the fontana ranuccio faunal unit. however, the chronological correlation of the site is very doubtful. parole chiave: stephanorhinus hemitoechus, tardo pleistocene medio, vitinia, italia centrale. keywords: stephanorhinus hemitoechus, late middle pleistocene, vitinia, central italy. 1. introduzione i rinoceronti rappresentano un elemento abbastanza comune nelle faune pleistoceniche europee, ciò nonostante, la sistematica di questi pachidermi è ancora fonte di dibattito e discussioni. inizialmente tutti i resti di rinoceronte non ascrivibili al genere coelodonta bronn, 1831 furono riferiti al genere rhinoceros l. e successivamente al genere dicerorhinus gloger, 1841. in particolare guérin (1980) ascrisse tali rinoceronti pleistocenici al genere dicerorhinus e attribuì le specie d. jeanvireti guérin, 1972, d. etruscus (falconer, 1868), d. hemitoechus (falconer, 1859) e d. kirchbergensis (jäger, 1839) (= d. mercki [kaup, 1841] in guérin, 1980) al nuovo sottogenere brandtorhinus; successivamente elevato a rango di genere (guérin, 1989). in accordo con groves (1983), i rinoceronti pleistocenici europei mostrano, comunque, poche similarità con il genere dicerorhinus. infatti, fra gli altri caratteri, la perdita e non funzionalità degli incisivi e il setto nasale parzialmente ossificato li distinguono dal suddetto genere attuale. la nomenclatura utilizzata in questo lavoro si basa su quella proposta da fortelius et al. (1993) ed i rinoceronti pleistocenici europei, tranne le specie dei generi coelodonta e elasmotherium fischer, 1808, sono riferiti al genere stephanorhinus kretzoi 1942 così come utilizzato precedentemente da diversi autori (inter alios heissing 1973, 1981, 1989; cerdeño 1993, 1995, 1998; prothero et al. 1986). il cranio analizzato proviene da depositi fluviali di fosso malafede (vitinia, roma), riferibili alla formazione di vitinia (sezione tipo vitinia, roma), 2. il cranio il cranio rinvenuto a fosso malafede (v. 2832) (fig. 1, 2; tab. 1) si presenta danneggiato nei nasali ed in parte nei palatali. a causa della presenza di superfici di l. pandolfi 172 fig. 1 il cranio di s. hemitoechus di fosso malafede (v. 2832): a) norma dorsale, b) norma laterale destra, c) norma laterale sinistra. la barra è di circa 10 cm. the skull of s. hemitoechus from fosso malafede (v. 2832): a) dorsal view, b) right lateral view, c) left lateral view. the bar is of about 10 cm. fig. 2 il cranio di s. hemitoechus di fosso malafede (v. 2832): a) norma occipitale, b) norma basale nucale. the skull of s. hemitoechus from fosso malafede (v. 2832): a) occipital view, b) basal nuchal view. tab. 1 dimensioni comparative del cranio di fosso malafede (v. 2832) e di s. kirchbergensis, s. hemitoechus (dati da guérin, 1980) e s. hundsheimensis di isernia la pineta (dati da lacombat, 2005). dtin = larghezza presa alla fine dell’incisura nasale; dtpo = larghezza presa a livello della costrizione post-orbitale; dto = diametro trasversale della cresta occipitale; dtm = diametro trasversale al livello delle apofisi mastoidee; dtc = diametro massimo trasversale dei condili occipitali; dtf = diametro trasversale del foramen magnum; hf = altezza del foramen magnum. comparative dimensions of the skull from fosso malafede (v. 2832) and of s. kirchbergensis, s. hemitoechus (data from guérin, 1980) and s. hundsheimensis from isernia la pineta (data from lacombat, 2005). dtin = breadth at the end of the nasal groove; dtpo = breadth at level of the post-orbital constriction; dto = breadth of the occipital crest; dtm = breadth at level of the mastoids; dtc = maximal breadth of the occipital condyles; dtf = breadth of the foramen magnum; hf = height of the foramen magnum. il cranio di stephanorhinus hemitoechus … 173 deformazione e di interventi di restauro, alcuni punti utili per ricavare dati morfometrici non possono essere presi in considerazione. in particolare, è stata ricostruita completamente l’arcata zigomatica destra, parte dei lacrimali, il rhinion, parte della base di attacco del corno nasale, il setto nasale, la parte prossimale dei mascellari e gli intermascellari. inoltre mancano quasi tutti i denti ad eccezione del secondo e terzo molare superiore sinistri, molto usurati. 2.1 norma dorsale appare ben evidente la ricostruzione di parte dell’area rostrale, ma, nonostante questo intervento e l’utilizzo di una tinta unita per l’intero cranio dopo il restauro, è ancora visibile una parte della base di attacco del corno nasale. la base di attacco del corno frontale è relativamente ampia e rugosa mentre le creste parietali e frontali non sono distinguibili (fig. 1a). la cavità orbitale sinistra, non ricostruita, è relativamente ampia e di aspetto ellittico, più larga posteriormente. in questa norma, la cresta occipitale presenta un profilo posteriore rettilineo. 2.2 norma laterale l’angolo fra il profilo parietale e quello fronto-nasale è molto accentuato (fig. 1b, c). il setto nasale non è ossificato posteriormente e questo carattere, fra gli altri, permette di distinguerlo dal genere coelodonta. la cresta occipitale si presenta molto sviluppata e si proietta all’indietro oltre i condili. il profilo è leggermente convesso fra i parietali e la cresta occipitale; la base di attacco del corno frontale è appena visibile. gli occipitali presentano un profilo verticale ed i condili occipitali hanno l’apice rivolto verso il basso. l’opisthion è ben evidente al di sopra del foramen magnum. sul lato destro del cranio la regione otica presenta un’apofisi post-glenoidea ben conservata ed un’apofisi paraoccipitale danneggiata nella parte distale, mentre non c’è evidenza dell’apofisi post-timpanica. l’apofisi post-glenoidea è verticale al cranio con profilo anteriore concavo ed è ben separata e distanziata alla base dall’apofisi paraoccipitale. la parte anteriore della cavità orbitale è sita sopra m3/, mentre l’incisura nasale ha il margine posteriore all’altezza di m1/. l’orbita è alta e l’arcata zigomatica sinistra è relativamente massiccia, inclinata e con profilo superiore regolarmente concavo nella parte prossimale. 2.3 norma nucale la faccia occipitale mostra il classico aspetto trapezoidale (fig. 2a). la cresta occipitale ha andamento leggermente convesso e gli occipitali hanno il diametro massimo in corrispondenza delle apofisi mastoidee. il foramen magnum ha forma quasi circolare ed i condili sono ben sviluppati. 2.4 norma basale i condili occipitali sono ben visibili e relativamente distanziati fra loro. in questa visione la cresta occipitale appare relativamente sporgente verso l’indietro. nessun altro carattere è ben distinguibile. l’area palatale è relativamente danneggiata e sul mascellare sinistro sono presenti un m3/ ed un m2/ il cui stadio di usura è particolarmente avanzato (fig. 3a; tab. 2). sul secondo molare è appena visibile la postfossetta, mentre la prefossetta è particolarmente ridotta; il terzo molare ha aspet fig. 3 comparazione fra gli stadi di usura del secondo e terzo molare superiori del cranio di fosso malafede (v. 2832) (a) la barra è di circa 2 cm) e di diceros bicornis (b) range di età stimato di circa 37±4 anni) (ridisegnato da hitchins, 1978) e ceratotherium simum (c) range di età compreso fra 30-38 anni; d) range di età compreso fra 35-40 anni) (ridisegnato da hillman-smith et al., 1986). comparison between the degrees of wear of the second and third upper molars in the skull from fosso malafede (v. 2832) (a) the bar is of about 2 cm) and in diceros bicornis (b) relative age of about 37±4 years) (redrawn from hitchins, 1978) and ceratotherium simum (c) wear class age between 30-48; d) wear class age between 35-40) (redrawn from hillman-smith et al., 1986). l. pandolfi 174 to triangolare e la mediofossetta appare chiusa. inoltre, nel secondo molare non sono più visibili le pieghe vestibolari, né eventuali cingula. lo smalto, a causa dell’usura, è quasi del tutto assente o è ridotto a sottili e piccole placchette sui lati mesiale e distale del secondo molare. 3. comparazione e stima dell’età alla morte il cranio rinvenuto a fosso malafede presenta caratteri morfologici riscontrabili nel genere stephanorhinus e mostra delle affinità con i crani della specie s. hemitoechus. in particolare: ٠ la morfologia dell’occipitale; in s. hemitoechus, infatti, la cresta occipitale si presenta molto sviluppata verso l’indietro tanto da sporgere ben oltre i condili, la squama occipitale è sub-verticale ed i condili occipitali sono rivolti verso il basso (falconer, 1868; azzaroli, 1962; guérin, 1980). questi caratteri, come sopra esposto, sono tutti presenti nel cranio di fosso malafede. in s. kirchbergensis, invece, i condili occipitali tendono a sporgere verso l’indietro più che la cresta occipitale, molto massiccia (azzaroli, 1962; billia, 2006). in s. hundsheimensis (toula, 1902) la cresta occipitale è leggermente sporgente verso l’indietro con bordo posteriore concavo al centro e la faccia occipitale, inferiormente, è leggermente obliqua verso l’indietro e il basso (lacombat, 2005); ٠ l’incisura nasale arretrata e la serie dentaria in posizione avanzata (azzaroli, 1962; guérin, 1980); nel cranio esaminato, come già visto, la parte anteriore della cavità orbitale è sita sopra m3/, mentre la parte posteriore delle cavità nasali si trova in corrispondenza della porzione distale di m1/; ٠ morfologia della regione otica; come ben illustrato da loose (1975) la regione otica dei rinoceronti fossili europei mostra alcune differenze, in parte riprese anche da guérin (1980). in s. hemitoechus, come nel cranio in studio, l’apofisi post-timpanica non è ben evidente e l’apofisi post-glenoidea e quella paraoccipitale sono più distanziate che nelle altre specie dello stesso genere. ٠ arcata zigomatica e posizione dell’orbita relativamente più alta se paragonato con i crani di s. kirchbergensis; questo carattere, tipico della specie s. hemitoechus, è ben descritto e illustrato da azzaroli (1962), loose (1975) e guérin (1980). in aggiunta a tali caratteristiche morfologiche, i valori morfometrici ricavabili dal cranio in studio si identificano molto ai corrispettivi valori medi dati da guérin (1980) per s. hemitoechus (tab. 1). i valori del diametro trasversale della cresta occipitale e del foramen magnum permettono di distinguere l’esemplare in studio da quelli ascritti a s. hundsheimensis del sito di isernia la pineta, mentre meno netta sembra la distinzione con quelli ascrivibili a s. kirchbergensis. le dimensioni del terzo molare superiore risultano maggiori che in s. hundsheimensis e rientrano nel campo di variazione di s. hemitoechus e s. kirchbergensis. il molare in questione si distingue comunque da quest’ultima specie per una minore ampiezza del lato mesiale in rapporto agli altri valori (tab. 2). infine, lo stadio di usura del secondo e del terzo molare superiore, comparata con i corrispondenti stadi di usura dei denti dei rinoceronti attuali riportati da hitchins (1978) e hillman-smith et al. (1986), in particolare per quelli africani, diceros bicornis l. e ceratotherium simum (burchell, 1817), può essere utile per stimare l’età di morte dell’animale. nel cranio in studio, in particolare, il secondo molare ha un profilo vestibolare quasi rettilineo e le fossette sono isolate e molto ridotte così come nel terzo molare. in diceros bicornis, fra i 30 ed i 36 anni di età, il secondo molare presenta le fossette isolate e molto ridotte, mentre il terzo molare ha uno stadio di usura molto avanzato. in aggiunta, nel secondo molare il profilo dell’ectolofo appare quasi rettilineo, il parastilo è assente ed, in generale, la lunghezza vestibolare tende a ridursi (hitchins, 1978) (fig. 3b). in ceratotherium simum, fra i 30 ed i 38 anni di età, si ha la quasi completa usura del secondo molare con le relative fossette che tendono a scomparire ed un’usura molto avanzata del terzo molare (hillmansmith et al., 1986) (fig. 3c, d). infine, l’età massima raggiunta dal rinoceronte nero (diceros bicornis) in natura è tab. 2 dimensione comparate del terzo molare superiore del cranio di fosso malafede (v. 2832) e di s. kirchbergensis, s. hemitoechus e s. hundsheimensis (dati da fortelius et al., 1993). bl = lunghezza buccale; ll = lunghezza linguale; mb = ampiezza mesiale. comparative dimensions of the third upper molar of the skull from fosso malafede (v. 2832) and of s. kirchbergensis, s. hemitoechus and s. hundsheimensis (data from fortelius et al., 1993). bl = buccal length; ll = lingual length; mb = mesial breadth. il cranio di stephanorhinus hemitoechus … 175 compresa fra i 30 ed i 35 anni, con piccole eccezioni che superano i 35 anni, mentre il rinoceronte bianco (ceratotherium simum) raggiunge solo in cattività i 40 anni (hillman-smith et al., 1986; nowak, 1999; brooks, 2002). da quanto sopra esposto si può attribuire al cranio di fosso malafede, con le dovute precauzioni, un’età compresa fra i 30 ed i 36 anni e desumere che il rinoceronte a cui apparteneva doveva essere un individuo senile, probabilmente deceduto a causa dell’età molto avanzata. 4. discussione e conclusioni rhinoceros hemitoechus fu utilizzato per la prima volta da falconer per identificare alcuni resti di rinoceronte rinvenuti in gran bretagna e solitamente il 1868 viene indicato come l’anno di pubblicazione. una nota nel manoscritto del 1868 afferma però che “the important essay on rhin. hemitoechus was written in 1859, but is now for the first time published” (falconer, 1868, pag. 309). dawkins (1867), tuttavia, riporta il nome della specie di falconer nella sinonimia di rhinoceros leptorhinus owen, 1846 affermando che r. hemitoechus è una specie segnalata da falconer (1860) nelle cave di gower (glamorganshire, galles) e che deve la propria esistenza alla traduzione della definizione di owen “à narines demi-cloisonnées” in un nome specifico in greco (dawkins, 1867). in precedenza gaudin (1859), però, affermava che falconer aveva riconosciuto una nuova specie, r. hemitoechus, nelle cave del glamorganshire e pertanto, in accordo con quanto riportato da van der made (2010), il 1859 viene preso come anno di pubblicazione della specie. alcuni autori hanno delineato un trend evolutivo per s. hemitoechus nel corso del tempo, basandosi sulle variazioni nella morfologia e morfometria dei crani e dei denti e delle variazioni di taglia e/o robustezza degli elementi post-craniali (azzaroli, 1962; guérin, 1980; fortelius et al., 1993; lacombat, 2005). in particolare, azzaroli (1962) istituì due sottospecie, una con caratteri meno evoluti per il pleistocene medio (d. hemitoechus falconeri), basata sui crani di bucine, mosbach e clacton ed una più evoluta per il pleistocene superiore (d. hemitoechus aretinus), basata sui crani di botro maspino, ilford ed altri. guérin (1980) ammette in realtà come nome valido per le forme del pleistocene medio d. hemitoechus hemitoechus, indicando minchin hole (cave di glamorganshire, su cui falconer istituì proprio la specie) come località tipo della specie nominale. secondo sutcliffe & bowen (1973) e sutcliffe (1981), però, i sedimenti di minchin hole, sono riferibili all’interglaciale eemiano, per cui la sottospecie nominale “hemitoechus” andrebbe attribuita alle forme del pleistocene superiore, mentre la sottospecie “falconeri” a quelle del pleistocene medio. inoltre, alcuni dei siti in cui azzaroli (1962) segnalava la presenza della forma più evoluta della specie (botro maspino, ponte alla nave) sono stati successivamente riferiti al tardo pleistocene medio o pleistocene superiore (uf di vitinia sensu gliozzi et al., 1997) (fortelius et al., 1993), per cui, il passaggio dalle forme indicate come “falconeri” a quelle indicate come “hemitoechus” potrebbe essere avvenuto prima dell’inizio del pleistocene superiore, presumibilmente intorno al mis7. d’altronde, anche lacombat (2005), sulla base dei resti post-craniali, riporta durante questo periodo un passaggio da forme di taglia più contenuta a forme di taglia decisamente più grande e robusta ed inoltre crani riferibili alla sottospecie s. h. hemitoechus vengono segnalati nei depositi lacustri del sito di neumarck-nord, correlabile con il mis7 (van der made, 2010). il cranio in esame mostra caratteristiche comparabili con i crani di minchin hole e ponte alla nave, come l’angolo fra il profilo parietale e quello fronto-nasale più accentuato ed un profilo più convesso fra i parietali e la cresta occipitale rispetto ai crani di clacton e bucine. in funzione di quanto detto quindi, il cranio di fosso malafede è ascrivibile alla sottospecie s. h. hemitoechus, in accordo anche con l’età del deposito in cui è stato rinvenuto. resti di s. hemitoechus sono segnalati in buona parte dell’europa centro-meridionale e parte della gran bretagna nonché in nord africa e medio oriente. la presenza di questa specie in asia sembra al momento molto dubbia; guérin (1980) riteneva, comunque, che i resti di rinoceronte di binagad (azerbaidjan), descritti da dzhafarov nel 1955, potessero essere riferiti a dicerorhinus hemitoechus. nell’europa continentale le segnalazioni più antiche riferibili a questa specie sono datate intorno alla seconda metà del pleistocene medio (ad esempio in siti come caune de l’arago; guérin, 1980; lacombat, 2005). in italia la prima presenza di questo rinoceronte veniva segnalata nella breccia ossifera di slivia, riferibile alla uf omonima (compresa fra i 900.000 e gli 800.000 anni bp) (ambrosetti et al., 1979; bon et al., 1992; gliozzi et al., 1997; palombo, 2004; palombo & mussi, 2006). in realtà i reperti presenti nella suddetta breccia meriterebbero un’osservazione più attenta in quanto la morfologia dei denti riportati in bon et al. (1992: fig. 3, pag. 39) si avvicina, a parere dello scrivente, più a quella di s. hundsheimensis che a s. hemitoechus (petronio & pandolfi, 2008). inoltre, tali resti venivano riferiti da ambrosetti et al. (1979) a forme intermedie fra s. etruscus e s. hemitoechus, paragonabili alle popolazioni di voigstedt e süssenborn, successivamente ascritte proprio a s. hundsheimensis. a questa specie sono riferibili anche i resti di rinoceronte provenienti dai depositi pleistocenici del torrente stirone (800-700 mila anni) ed assegnati da cigala fulgosi (1976) a d. hemitoechus. il cranio proveniente da questo sito infatti è comparabile con quello di altri esemplari di s. hundsheimensis e presenta, rispetto a s. etruscus, un angolo fra parietali e frontali più aperto con nasali e frontali più allungati, incisura nasale più lunga e orbite più strette, mentre rispetto a s. hemitoechus presenta una faccia occipitale inferiormente più obliqua verso l’indietro e il basso, con la sommità meno estesa verso l’indietro, un profilo della cresta occipitale concavo e, infine, un allargamento posteriore delle arcate zigomatiche meno marcato. una mandibola, completa di serie dentaria, ed ascritta a s. hemitoechus, viene segnalata nei livelli a sabbie e conglomerati del sito di cava di breccia di ponte galeria (petronio, 1988), correlabili con un intervallo cronologico compreso fra i 750.000 ed i 650.000 anni (petronio & sardella, 1999). la mandibola in questione ed i denti ad essa connessi, presentano però caratteri morfologici e morfometrici comparabili con s. l. pandolfi 176 hundsheimensis. in particolare, il p/2 presenta la sola valle posteriore ed ha dimensioni relativamente grandi, a differenza della specie s. hemitoechus che presenta, nel medesimo dente, anche una valle anteriore e dimensioni più contenute (guérin, 1980; lacombat, 2005). infine, altro elemento morfologico importante, le valli posteriori di m/2 e di m/3 della mandibola di ponte galeria si presentano ad u, mentre in s. hemitoechus la morfologia della valli è quasi esclusivamente a forma di v (guérin, 1980; lacombat, 2005). si può aggiungere che non esistono al momento segnalazioni relative a s. hemitoechus in siti riferibili alla uf di isernia (compresa fra i 650.000 ed i 550.000 anni bp), considerando anche che la segnalazione nel sito di visogliano (bartolomei et al., 1977; fortelius et al., 1993) è stata poi riferita a s. hundsheimensis da abbazzi et al. (2000) e sardella et al. (2006). infine, un frammento di mandibola con m/1 ed m/2 proveniente dai depositi fluviali di monte verde (roma) può essere attribuita a s. hemitoechus per la presenza, nei molari, di valli linguali a forma di v, di cingula linguali e per la differenza quasi nulla in altezza fra le basi delle suddette valli (cfr. lacombat, 2006). per la presenza di bos primigenius ed ursus deningeri, i depositi in questione vengono correlati con la uf di fontana ranuccio (sensu gliozzi et al., 1997; di stefano et al., 1998). in realtà i reperti sono stati raccolti all’inizio del secolo scorso da terrazzi del tevere; di questi rinvenimenti tuttavia non si conosce la posizione stratigrafia e non si è certi nemmeno della precisa provenienza. resti attribuibili a s. hemitoechus sono segnalati a partire dalla uf di torre in pietra (sensu gliozzi et al., 1997). in particolare, questa specie è presente nei livelli inferiori di torre in pietra, a castel di guido, cretone e malagrotta (capasso barbato & petronio, 1981; caloi & palombo, 1978, 1979; di stefano et al., 1998; di canzio et al., 2003). s. hemitoechus risulta ben rappresentato nelle associazioni faunistiche riferite anche alla uf di vitinia (sensu gliozzi et al., 1997) come quelle rinvenute nei depositi di monte sacro, prati fiscali e tor di quinto (di stefano et al., 1998). recentemente, palombo et al. (2003), sulla base di nuove interpretazioni stratigrafiche e datazioni radiometriche di alcuni siti dell’area urbana di roma, suggeriscono di destituire la uf di vitinia e di riferire tutti i complessi faunistici del tardo pleistocene medio del lazio alla uf di torre in pietra. questo perché i bioeventi che caratterizzano la uf di vitinia così come formalizzata da gliozzi et al. (1997) sarebbero predatati e la uf di torre in pietra, nella sua nuova definizione, sarebbe caratterizzata dalle prime comparse di canis lupus l., ursus spelaeus rosenmüller & heinroth, 1794, megaloceros giganteus blumenbach, 1799, dama dama tiberina di stefano & petronio, 1997 e dalla persistenza di dama clactoniana (falconer, 1868) (palombo et al., 2003). la nuova uf di torre in pietra comprenderebbe così tutte le associazioni faunistiche rinvenute nei depositi riferibili alle formazioni aurelia e vitinia o nelle sequenze deposizionali di quarto ordine pg6 (mis10-8) e pg7 (mis8-6) descritte da milli (1997). di conseguenza, l’intervallo temporale definito dalla uf di torre in pietra risulta dilatato rispetto a quanto riportato da gliozzi et al. (1997). fortunatamente, il cranio in esame proviene da depositi riferibili alla formazione vitinia (mis7), per cui, in questo caso, l’età relativa del reperto rimane invariata, così come rimane invariata l’età dei reperti provenienti dai livelli inferiori del sito di torre in pietra, riferibili alla formazione aurelia. diversa è invece la situazione per siti come cretone, tor di quinto e monte sacro, i cui depositi, al momento, non risultano inquadrabili in una delle due formazioni; i siti in questione sono quindi correlabili con un intervallo temporale che va dal mis10 al mis6. probabilmente, ulteriori analisi morfologiche e morfometriche dei resti di rinoceronte provenienti dai suddetti siti permetterà di riferire gli stessi ad uno degli stadi evolutivi di s. hemitoechus che caratterizzano il pleistocene e quindi correlare i siti in questione con un intervallo temporale più ristretto. in accordo quindi con quanto sopra discusso, la comparsa di s. hemitoechus in italia andrebbe, al momento, a collocarsi con certezza all’inizio dell’età a mammiferi aureliano (uf di torre in pietra) in depositi riferibili alla formazione aurelia (mis10-8). bibliografia abbazzi l., fanfani f., ferretti m.p., rook l., cattani l., masini f., mallegni f., negrino f. & tozzi c. (2000) new human remains of archaic homo sapiens and lower palaeolithic industries from visogliano (duino aurisina, trieste, italy) journal of archaeological science, 27, pp. 1173-1186. ambrosetti p., bartolomei g., de giuli f., ficcarelli f. & torre d. (1979) la breccia ossifera di slivia (aurisina-sistiana) nel carso di trieste bollettino della società paleontologica italiana, 18, pp. 207-220. azzaroli a. (1962) validità della specie rhinoceros hemitoechus falconer paleontographia italica, 57, pp. 21-34. bartolomei g., peretto c. & sala b. (1977) depositi a loess con ochotona e rinoceronte nel carso di trieste atti accademia nazionale dei lincei, serie 8, 61 (3-4), pp. 280-283. billia e.m.e. (2006) the skull of stephanorhinus kirchbergensis (jäger, 1839) (mammalia, rhinocerotidae) from irkutsk province, eastern siberia russian journal of theriology, 5 (2), pp. 63-71. bon m., piccoli g. & sala b. (1992) la fauna pleistocenica della breccia di slivia (carso triestino) nella collezione del museo civico di storia naturale di trieste atti del museo civico di storia naturale di trieste, 44, pp. 33-51. brooks m. (2002) proceedings of african rhino specialist group meeting in iucn-ssc-afrsg. emslie, r (ed.). malilangwe, zimbabwe: iucn/ ssc, african rhino specialist group. caloi l. & palombo m. r. (1978) anfibi, rettili e mammiferi di torre del pagliaccetto (torre in pietra, roma) quaternaria, pp. 315-428. caloi l. & palombo m. r. (1979) resti di mammiferi del pleistocene medio di malagrotta (roma) bollettino del servizio geologico d’ italia, 50, pp. 141-188. caloi l., palombo m.r. & zarlenga f. (1998) late middle pleistocene mammal faunas of lazio (central italy): stratigraphy and environment quaternary international, 47/48, pp. 77–86. capasso barbato l. & petronio c. (1981) la mammalofauna pleistocenica di castel di guido (roma) il cranio di stephanorhinus hemitoechus … 177 bollettino del servizio geologico d’italia, 52, pp. 95-108. cerdeño e. (1993) remarks on the spanish plio-pleistocene stephanorhinus etruscus (rhinocerotidae) comptes rendus de l’academie des sciences de paris, 317, pp. 1363-1367. cerdeño e. (1995) changes in western european rhinocerotidae related to climatic variations palaeogeography, palaeoclimatology, palaeoecology, 114, pp. 325-338. cerdeño e. (1998) diversity and evolutionary trends of the family rhinocerotidae (perissodactyla) palaeogeography, palaeoclimatology, palaeoecology, 141, pp. 13-34. cigala-fulgosi f. (1976) dicerorhinus hemitoechus (falconer) del post-villafranchiano fluviolacustre del t. stirone (salsomaggiore, parma) bollettino della società paleontologica italiana, 15, pp. 59-72. conato v., esu d., malatesta a. & zarlenga f. (1980) new data on the pleistocene of rome quaternaria, 22, pp. 131–176. dawkins w. b. (1867) on the dentition of rhinoceros leptorhinus (owen) quarterly journal of the geological society, 23 (1-2), pp. 213-227. di canzio e., bedetti c., petronio c. & sardella r. (2003) middle pleistocene vertebrate fauna from cretone (sabina, latium) bollettino della società paleontologica italiana, 42 (1-2), pp. 129-132. di stefano g., petronio c. & sardella r. (1998) biochronology of the pleistocene mammal faunas from rome urban area -+ il quaternario, 11 (2), pp. 191-199. dzhafarov r.d. (1955) novy predstavitel’ chetvertichnykh nosorogov (rhinoceros binagadensis sp. nova) binagadinskoy fauny [a new representative of the quaternary rhinoceros (rhinoceros binagadensis sp. nova) in the binagad fauna location of quaternary fauna and flora at binagad] trudy estest.-istoricheskogo muzeya im. g. zardaby, iv, pp. 65-88, izd-vo an azerbssr, baku [in russian]. falconer h. (1860) on the ossiferous caves of the peninsula of gower, in glamorganshire, south wales quarterly journal of the geological society, 16, pp. 487-491. falconer h. (1868) on the european pliocene and postpliocene species of the genus rhinoceros paleontological memoires and notes, 2, pp. 309-403. fortelius m. (1982) ecological aspects of dental functional morphology in the plio-pleistocene rhinoceroses of europe in b. kurtén (ed.), teeth: form, function and evolution: 163-181. new york: cambridge univ. press. fortelius m., mazza p. & sala b. (1993) stephanorhinus (mammalia, rhinocerotidae) of the western european pleistocene, with a special revision of stephanorhinus etruscus (falconer, 1868) paleontographia italica, 80, pp. 63-155. gaudin c.t. (1859) modifications apportés par mr. falconer a la faune du val d’arno bullettin de la societe vaudoise de science naturelles, 6, 44, pp. 130-131. gliozzi e., abbazzi l., ambrosetti p., argenti p., azzaroli a., caloi l., capasso barbato l., di stefano g., esu d., ficcarelli g., girotti o., kotsakis t., masini f., mazza p., mezzabotta c., palombo m.r., petronio c., rook l., sala b., sardella r., zanalda e. & torre d. (1997) biochronology of selected mammals, molluscs, ostracods from the middle pliocene to the late pleistocene in italy. the state of the art rivista italiana di paleontologia e stratigrafia, 103 (3), pp. 369-388. groves c.p. (1983) phylogeny of the living species of rhinoceros sonderdruck aus z. f. zool. systematik u. evolutionsforschung, 21, pp. 293-313. guerin c. (1980) les rhinocéros (mammalia, perissodactyla) du miocène terminal au pléistocène supérieur en europe occidentale. comparaison avec les espèces actuelles documents du laboratoire de géologie de lyon, 79 (1-3), pp. 1-1185. guerin c. (1989) la famille des rhinocerotidae (mammalia, perissodactyla): systématique, histoire, évolution, paléoécologie cranium, 6, pp. 3-14. heissig k. (1973) die unterfamilien und tribus der rezenten und fossilen rhinocerotidae (mammalia) säugetierkundl mitt, 21, pp. 25-30. heissig k. (1981) probleme bei der cladistischen analyse einer gruppe mit wenigen eindeutigen apomorphien: rhinocerotidae paläontologische zeitschrift, 55, pp. 117-123. heissig k. (1989) rhinocerotidae in: prothero d.r, schoch, r.m., (eds.), the evolution of perissodactyls. oxford university press, pp. 399-417. hillman-smith, a.k.k., owen-smith, n., anderson, j.l., hall-martin, a.j., selaladi, j.p. (1986) age estimation of the white rhinoceros (ceratotherium simum) journal of zoology london, series a, 210, pp. 355-379. hitchins p.m. (1978) age determination of the black rhinoceros (diceros bicornis linn.) in zululand south african journal of. wildlife research, 8, pp. 7180. jäger g.f. (1839) uber die fossilen saugethiere, welche in wiirtemberg in verschiedenen formationen aufgefunden worden sind, nebst geognostischen bemerkungen iiber diese formationen abtheilung, 2, pp. 71-212. kaup j.j. (1841) akten der urwelt oder osteologie der urweltlichen säugethiere und amphibien darmstadt, publ. by the author. lacombat f. (2005) les rhinocéros fossiles des sites préhistoriques de l’europe méditerranéenne et du massif central. paléontologie et implications biochronologiques bar international series, 1419, 175 pp. loose h. (1975) pleistocene rhinocerotidae of western europe with reference to the recent twohorned species of africa and s.e. asia scripta geologia, 33, pp. 1-59. van der made j. (2010) the rhinos from the middle pleistocene of neumark-nord (saxony-anhalt) in: neumark-nord: ein interglaziales ökosystem des mittelpaläolithischen menschen. veröffentlichungen des landesmuseums für vorgeschichte, band 62, pp. 433-537. malatesta a. & zarlenga f. (1988) evidence of middle pleistocene marine transgressions along the mediterranean coast palaeogeography, palaeoclimatology, palaeoecology, 68, pp. 311315. l. pandolfi 178 marra f. & rosa c. (1995) stratigrafia e assetto geologico dell’area romana memorie descrittive della carta geologica d’italia, 50, pp. 49-118. milli s. (1997) depositional setting and high-frequency sequence stratigraphy of the middle-upper pleistocene to holocene deposits of the roma basin geologica romana, 33, pp. 99-136. nowak r.m. (1999) walker's mammals of the world 6th ed. the johns hopkins univ. press, baltimore. palombo m.r. (2004) guilds of large mammals from the pliocene to the late pleistocene in italian peninsula in baquedano e. & rubio s. (eds.), homenaje a emiliano aguirre, zona arqueologica, 4 (2 paleontologia): 372-391. museo arqueológico regional, madrid. palombo m.r. & mussi m. (2006) large mammal guilds at the time of the first human colonization of europe: the case of the italian pleistocene record quaternary international, 149, pp. 94-103. palombo m.r., milli s. & rosa c. (2003) remarks on the biochronology of the late middle pleistocene mammalian faunal complex of the campagna romana (latium, italy) geologica romana, 37, pp. 135-143. petronio c. (1988) una mandibola di rinoceronte di ponte galeria (roma) atti della società italiana di scienze naturali e del museo civico di storia naturale di milano, 129 (2-3), pp. 173-178. petronio c. & sardella r. (1999) remarks on tha stratigraphy and biochronology of the late pleistocene deposito f ingarano (apulia, southern italy) rivista italiana di paleontologia e stratigrafia, 104 (2), pp. 287-294. petronio c. & pandolfi l. (2008) stephanorhinus hemitoechus del pleistocene superiore dell’area di melpignano-cursi e san sidero (lecce, italia). geologica romana, 41, pp. 1-12. petronio c., bellucci l., martinetto e., pandolfi l. & salari l. (in press) biochronology and palaeoenvironmental changes from the middle pliocene to the late pleistocene in central italy geodiversitas. prothero d.-r., manning e. & hanson c.-b. (1986) the phylogeny of rhinocerotoidea zoological journal of the linnean society, 87, pp. 341-366. sardella r., palombo m.r., petronio c., bedetti c. & pavia m. (2006) the early middle pleistocene large mammal faunas of italy: an overview quaternary international, 149, pp. 104-109. staesche k. (1941) nashörner der gattung dicerorhinus aus dem diluvium württembergs abhandlungen der. preußischen geologischen landesanstalt. hf. 200, 1148 pp. sutcliffe a.j. (1981) progress report on excavations in minchin hole, gower. quaternary newsletter, 33, pp. 1-7. sutcliffe a.j. & bowen d.q. (1973) preliminary report on excavations in minchin hole april-may 1973. newsletter william pengelly cave studies trust, 21, pp. 12-25. wüst e. (1922) beiträge zur kenntnis der diluvialen nashörner europas centralblatt fürmineralogie, geologie und paläontologie, 20, pp. 641-656; 21, pp. 680-688. zeuner f. (1934) die beziehungen zwischen schädelform und lebensweise bei den rezenten und fossilen nashörnern berichte der naturforschenden gesellschaft zu freiburg, 34, pp. 21-80. ms. ricevuto il 27 ottobre 2010 testo definitivo ricevuto il 31 maggio 2011 ms. received: october 27, 2010 final text received: may 31, 2011 base significato paleoclimatico dei rapporti tra il glacialismo principale e quello tributario nella bassa valle della dora baltea maria gabriella forno, franco gianotti & gianluca racca dipartimento di scienze della terra, università, torino corresponding author: f. gianotti <franco.gianotti@unito.it> riassunto: forno m. g., gianotti f. & racca g., significato paleoclimatico dei rapporti tra il glacialismo principale e quello tributario nella bassa valle della dora baltea (alpi occidentali). (it issn 0394-3356, 2010). uno studio condotto nella bassa valle della dora baltea ha permesso di ricostruire una successione terrazzata di lembi di depositi glaciali, legati al ghiacciaio principale; sono inoltre stati individuati significativi apparati morenici, legati ai ghiacciai tributari di sinistra (bacini dei torrenti chiussuma, maroncello e viona). i diversi lembi poggiano su superfici di erosione modellate nel substrato roccioso, rappresentato essenzialmente dai micascisti eclogitici della zona sesia-lanzo (sistema australpino). i depositi legati al ghiacciaio principale sono riferibili in netta prevalenza a facies di margine glaciale (till di colata, depositi fluvioglaciali e glaciolacustri) e subordinatamente subglaciali (till di allogamento e till di fusione): sono caratterizzati da discreta varietà petrografica, connessa con il vasto bacino della dora baltea. i depositi legati ai ghiacciai tributari sono invece più monotoni sia per quanto riguarda le facies osservabili (essenzialmente till di colata di margine glaciale) che per quanto riguarda la composizione petrografica, limitata ai litotipi locali. le forme di accumulo risultano al contrario meglio espresse e diagnostiche per i lembi legati al glacialismo tributario (evidenti cordoni morenici sia laterali che frontali), rispetto a quelli del ghiacciaio principale, rappresentati prevalentemente da coltri sottili e discontinue, con eccezione di rare ma notevoli morene laterali (gorgiasso, chanton). l’insieme degli elementi raccolti ha permesso di distinguere anche in valle, per la successione legata al ghiacciaio principale, quattro alloformazioni di depositi glaciali già riconosciute in anfiteatro (bornasco, serra, piverone e ivrea) databili al pleistocene medio-superiore. l’alloformazione più recente (af di ivrea), riferibile al last glacial maximum (lgm) e al successivo tardoglaciale, è stata ulteriormente suddivisa morfostratigraficamente in allomembri (andrate, quintas, pavone, prà san pietro e torredaniele) geneticamente legati alla locale sequenza di stadi glaciali riferibili al lgm. i depositi dei ghiacciai tributari sono stati invece riuniti prevalentemente in una sola alloformazione (trovinasse), riferibile al lgm e al tardoglaciale, e per la restante parte in un allogruppo (rionca) comprendente i depositi glaciali pre-lgm. per quanto concerne i rapporti tra glacialismo principale e tributario, si possono valutare differenti situazioni nei diversi bacini presi in considerazione. in particolare la distribuzione delle morene terminali prova che il ghiacciaio del chiussuma, con bacino di alimentazione esteso e prevalentemente esposto verso nw, raggiungeva il fondovalle (350 m) nel lgm e si saldava ancora con quello principale, quando quest’ultimo si era ormai ritirato in bassa valle dopo aver abbandonato l’anfiteatro morenico d’ivrea. i depositi del ghiacciaio del viona, riferibili anch’essi al lgm, indicano al contrario che questo ghiacciaio, caratterizzato da un bacino di alimentazione meno esteso e da esposizione verso sud, non giunse a saldarsi a quello principale nell’ultima espansione. i sedimenti del ghiacciaio del maroncello testimoniano, infine, come anche bacini laterali, di piccola estensione, quota non elevata ed esposizione sfavorevole (sw), sviluppassero nel lgm lingue glaciali significative che scendevano al di sotto dei 1000 m, raggiungendo il ghiacciaio principale. la separazione dei ghiacciai del maroncello e del chiussuma dal ghiacciaio della dora baltea avvenne, secondo la presente ricostruzione, rispettivamente nel corso degli stadi di quintas e di torredaniele. per i diversi ghiacciai tributari, ora del tutto scomparsi, si è proceduto al calcolo della quota della linea di equilibrio (equilibrium line altitude ela) con rapporto aar di 0,67. per il ghiacciaio del viona si ottiene una ela di 1535 m nello stadio di massima espansione (andrate); per il chiussuma la ela è di 1480 m in un momento correlabile allo stadio di torredaniele; per il piccolo ghiacciaio del maroncello la ela è di 1430 m durante uno stadio correlabile a quello di quintas. abstract: forno m. g., gianotti f. & racca g., palaeoclimatic interpretation of the relations between the main and the tributary glaciers in the lower dora baltea valley (western alps). (it issn 0394-3356, 2010). a detailed geological survey of the low sector of the dora baltea valley and the proximal sector of the morainic ivrea amphitheatre (ami) was made, to collect new quaternary geological data in this poorly studied area. here the bedrock is mainly composed of eclogite mica schist of the the sesia-lanzo zone, part of the austroalpine system. the research allows us to reconstruct a glacial terraced succession, preserved in relict limbs and connected with the main valley. significant moraines of tributary glaciers (viona, chiussuma and maroncello basins) have also been observed. the various limbs lie on erosional surfaces shaped in the substratum. the sedimentologic characters of various glacial and glaciofluvial facies are also described regarding the clast/matrix relation, the matrix texture, the clast form, the possible stratification, the degree of consolidation of the sediments. the morphologic evidence of limbs (morainic ridges, kame terraces and limbs without morphological evidence) is also traited. the sediments linked to the main glacier are prevalently of glacial margin (flow till, glaciofluvial and glaciolacustrine deposits) and, subordinately, subglacial sediments (lodgement till and melt-out till): they show a significant petrographical variety connected with the wide dora baltea basin. the sediments linked to the tributary glaciers have, instead, a monotonous facies (prevalently marginal flowtill) and a monotonous petrographical composition, limited to local lithotypes. the morphological expression is more significant for limbs linked to the tributary glaciers (evident lateral and end moraines), compared with the main glacier features, consisting prevalently in thin and discontinuous limb, with a few exceptions of lateral moraines (gorgiasso, chanton). the collected elements allow us to distinguish in the valley sector four alloformations of glacial sediments linked with the main glacier (bornasco, serra, piverone e ivrea), referred to the time period of the middle-late pleistocene, already known in the amphitheatre. the younger alloformation (af di ivrea), referred to the last glacial maximum (lgm) and to the subsequent tardoglacial, is morphostratigraphycally further divided in four allomembers (andrate, quintas, pavone, prà san pietro and torredaniele). these allomembers are connected to the local sequence of lgm glacial stages. the tributary basin deposits are, instead, assembled prevalently in a single alloformation (trovinasse), referred to the lgm and tardoglacial, and for the remainder in another allogroup (rionca), comprising the pre-lgm glacial deposits. as far as the relation between the main and the tributary glaciers is concerned, various evidence is provided by different sectors. the morphostratigraphic cross section of the examined area shows the intersection relationship between the tributary glaciers moraines of the chiussuma, maroncello and viona basins and the main dora baltea glacier moraines. il quaternario italian journal of quaternary sciences 23(1), 2010 105-124 106 m.g. forno, f. gianotti & g. racca 1. introduzione lo studio prende in esame il versante sinistro della bassa valle della dora baltea (fig. 1), che conserva un ampio record di episodi glaciali essenzialmente erosivi, al raccordo con l’anfiteatro morenico d’ivrea (ami) (fig. 2), dove si ha una diffusa testimonianza di importanti fenomeni deposizionali accompagnati da un generalizzato approfondimento glaciale. un rilevamento geologico alla scala 1:10.000 (racca, 2002) e la fotointerpretazione di un’area di 55 km2 hanno consentito di ricostruire per quest’area una successione stratigrafica in detail, the end moraines distribution shows that the chiussuma glacier reached the valley floor (350 m of elevation) during the lgm: this glacier connected to the main glacier located in the lower dora baltea valley, after the withdrawal from the ivrea morainic amphitheatre. the viona glacier sediments, referred to lgm, prove, instead, that this glacier has not joined the main glacier in the last glaciation. the maroncello glacier sediments suggest, finally, that short tributary basins, with scarce elevation and unfavourable exposition, experimented significant glaciers, developed below 1.000 m of elevation and joined the main glacier. the separation of the maroncello and chiussuma glaciers from the dora baltea glacier happened in the quintas and torredaniele glacial stages, respectively. for different tributary glaciers, now completely absent, we have calculated the equilibrium line altitude (ela), using a ratio aar of 0,67. in the viona valley we obtained an ela of 1.535 m in the main expansion stadial (andrate); in the chiussuma basin the calculated ela is 1.480 in the torredaniele stadial; in the short maroncello glacier the calculated ela is 1.430 m during the quintas stadial. parole chiave: depositi glaciali, ghiacciai, ela, lgm, valle della dora baltea. keywords: glacial sediments, glaciers, ela, lgm, dora baltea valley. fig. 1 panorama generale del versante sinistro della bassa valle della dora baltea dalla cima cavallaria: sono conservate le tracce del ghiacciaio principale e dei ghiacciai tributari (bacini del chiussuma, maroncello e viona). le linee tratteggiate sulla destra indicano le creste delle morene laterali della serra d’ivrea e della piccola serra. general view of the left slope of the lower dora baltea valley from cima cavallaria: the traces of both the main glacier and the tributary glaciers are well preserved. dottes lines on the right indicate the crests of serra d’ivrea and piccola serra lateral moraines. fig. 2 vista panoramica dello sbocco della valle della dora baltea (a sinistra) dalla depressione interna dell’anfiteatro morenico, con i bacini tributari del maroncello (a) e del viona (b). sulla destra si sviluppano la morena laterale “serra d’ivrea” (c) e i rilievi rocciosi di esarazione noti come colli d’ivrea (d). panoramic view of the dora baltea valley outlet (left), with the maroncello (a) and viona (b) tributary basins, from the morainic amphitheatre internal plain. on the right the serra d’ivrea lateral moraine (c) and the colli d’ivrea glacially-sculpted hills (d) may be observed. pleistocenica legata al glacialismo del bacino della dora baltea e dei bacini tributari, rappresentata in modo frammentario e generico nelle cartografie precedenti soprattutto per quanto riguarda il settore vallivo. il riconoscimento nel bacino della dora baltea di quattro principali unità allostratigrafiche si basa sui rapporti che intercorrono tra i differenti corpi sedimentari, sulla loro distribuzione plano-altimetrica, sull’eventuale interposizione di scarpate modellate in roccia, sui caratteri di alterazione pedogenetica, e, in misura minore, sul grado di rimodellamento delle forme, ed è supportata da alcuni dati cronologici desunti dalla letteratura. un’ulteriore suddivisione dei sedimenti riferiti all’episodio glaciale più recente si basa invece sulla distinzione degli elementi morfologici che scandiscono le tappe del ritiro glaciale, permettendo di differenziare più in dettaglio una successione di unità morfostratigrafiche (cfr. § 5.2). il rinvenimento di diffuse testimonianze glaciali nei bacini tributari, che intersecano quelle relative alla valle principale, hanno permesso di chiarire le relazioni cro107significato paleoclimatico dei rapporti tra ... nologiche esistenti tra la lingua glaciale principale e quelle affluenti (cfr. § 5.3). queste evidenze hanno inoltre consentito di effettuare una ricostruzione delle linee di equilibrio (ela equilibrium line altitude) per i diversi bacini tributari, che tiene conto dei differenti stadi nei quali i ghiacciai raggiunsero la massima estensione altimetrica (cfr. § 7.2). 2. inquadramento geologico l’area in esame si estende al limite tra l’esteso bacino montano della dora baltea, caratterizzato dai rilievi più elevati dell’intero arco alpino e coincidente in gran parte con la regione valle d’aosta, e l’anfiteatro morenico d’ivrea (ami), con estensione di circa 500 km2 e compreso interamente in territorio piemontese (fig. 3). il settore vallivo, attualmente privo di ghiacciai, corrisponde al tratto del versante sinistro, sviluppato tra la sommità della colma di mombarone (2371 m) e il fondovalle della dora baltea tra pont saint martin (310 fig. 3 inquadramento geologico dell’area di studio (riquadro), compresa tra il bacino montano della dora baltea e l’anfiteatro morenico d’ivrea. geological sketch map of the studied area (box), developed between the dora baltea valley and the ivrea morainic amphitheatre. 108 m) e s. germano (255 m). questo settore, inciso dai bacini laterali del t. chiussuma e del t. maroncello, conserva in modo discontinuo i depositi connessi con il glacialismo principale pleistocenico nella fascia altimetrica compresa tra i 1250 m a monte (morena di chanton sul versante destro sopra pont saint martin) e i 940 m a valle (inizio della serra d’ivrea ad andrate) e il fondovalle alluvionale (tra 310 e 250 m) (fig. 1). nel settore vallivo sono anche relativamente diffusi i depositi connessi con il glacialismo tributario pleistocenico, che appaiono confinati entro le incisioni laterali e distribuiti nei settori compresi tra i circhi montani (1800-2100 m) e quote prossime al fondovalle della dora baltea (330 m). il settore di anfiteatro morenico corrisponde alla parte prossimale del settore laterale sinistro dell’ami, sviluppata nella fascia altimetrica compresa tra la sommità della serra d’ivrea (940 m) e il fondo della depressione interna nel tratto tra s. germano (255 m) e borgofranco d’ivrea (250 m): il suo margine esterno è profondamente inciso dal t. viona, tributario del t. elvo. questo settore conserva diffusamente, in tutta la sua estensione altimetrica, i depositi connessi con il glacialismo principale. nella vasta depressione interna dell’ami (circa 200 km2) particolarmente significativo dal punto di vista morfologico è l'areale dei colli d’ivrea, in cui si osserva un gruppo di rilievi montonati, modellati nel substrato e con dislivello fino a oltre 200 m rispetto al fondovalle, che racchiudono cinque bacini lacustri di esarazione glaciale. questi rilievi rappresentano in italia uno dei luoghi dove sono meglio osservabili le forme di modellamento subglaciale a varia scala (forno et al., 2005a, 2005b, 2007). confrontando i due settori di studio, si osserva come nel settore vallivo i depositi glaciali si distribuiscano prevalentemente in lembi discontinui e privi di espressione morfologica diagnostica, con rari relitti di cordoni morenici, mentre in anfiteatro i depositi formano cordoni molto rilevati e continui, soprattutto per quanto riguarda i settori a quota più elevata. il substrato dei depositi legati al glacialismo quaternario è costituito da rocce metamorfiche di pertinenza austroalpina e sudalpina, messi a contatto da un’importante discontinuità tettonica nota localmente come linea del canavese esterna, ad andamento sw-ne, appartenente alla linea insubrica o periadriatica (biino & compagnoni, 1989). la discontinuità separa due settori topograficamente e morfologicamente ben distinti: i rilievi alpini a nw, marcatamente più elevati, costituiti da rocce metamorfiche austroalpine in facies eclogitica (complesso dei micascisti eclogitici della zona sesialanzo; compagnoni et al., 1977; venturini, 1995) e i colli d’ivrea a se, costituiti dal basamento sudalpino a metamorfismo pre-alpino (scisti di basso grado, intrusi da graniti e dioriti, della zona del canavese; granuliti basiche, di alto grado metamorfico, della zona ivreaverbano; zingg et al., 1990) e dalle coperture vulcanosedimentarie non metamorfiche o parzialmente interessate da anchimetamorfismo alpino (sequenza permogiurassica della zona del canavese; baggio, 1965). solo localmente, nell’incisione del t. ingagna a est di donato, poco oltre i limiti dell’area di studio, affiorano ghiaie e sabbie fluviali preglaciali, riferibili verosimilmente al pleistocene inferiore (forno & lucchesi, 2000). 3. studi precedenti la genesi glaciale dell’anfiteatro morenico d’ivrea (ami) fu già riconosciuta da martins & gastaldi (1850). nei primissimi rilievi di gastaldi e di bruno, confluiti nella carta delle alpi occidentali a scala 1:400.000 (franchi et al., 1908) e ripresi successivamente da baretti (1866), da bruno (1877) e da sacco (1888), l’ami venne descritto come costituito da “depositi morenici”, indifferenziati dal punto di vista stratigrafico. penck et al. (1894) e penck & brückner (1909) riconobbero nell’ami due delle glaciazioni alpine (riss e würm) proposte nella loro classica stratigrafia e citarono la serra d’ivrea come “maggiore morena delle alpi”. la stessa stratigrafia venne applicata nella prima edizione del foglio 42 “ivrea” (franchi et al., 1912) e del foglio 43 “biella” (franchi & stella, 1933) della carta geologica d’italia alla scala 1:100.000. i cordoni esterni alla serra d’ivrea sono stati qui indicati come “morene antiche prewürmiane”, mentre quelli interni come “morene würmiane, postwürmiane e recenti”. sacco (1927) distinse nell’ami sedimenti connessi con tre “glaciazioni”, correlate dubitativamente con le glaciazioni mindel, riss e würm di penck & brückner (1909): in particolare la serra d'ivrea e l'intero settore frontale vennero ritenuti rissiani. le suddivisioni di sacco (1927) vennero confermate nella seconda edizione del foglio “biella” della carta geologica d’italia alla scala 1:100.000 (bortolami et al., 1966) e in successivi lavori di sintesi (carraro & petrucci, 1969; carraro et al., 1975). i depositi dell’anfiteatro sono stati più recentemente differenziati in tre gruppi principali, su base pedostratigrafica e morfologica (carraro et al., 1991; carraro, 1992; arobba et al., 1997): il gruppo di s. michele-borgo è costituito dai depositi più antichi, conservati nella parte esterna del settore sinistro dell’ami; il gruppo della serra d’ivrea comprende la quasi totalità delle morene degli apparati laterali e frontale; il gruppo di bollengo-albiano riunisce, infine, ridotti segmenti dell’arco morenico più interno. in ricerche successive, riguardanti la stratigrafia dell’intero anfiteatro, gianotti (2007) ha distinto nell'ami dieci alloformazioni, riferite ad altrettanti episodi glaciali e differenziate su base pedostratigrafica o perchè separate da paleosuoli o da intercalazioni di depositi palustri organici. per quanto riguarda i dati paleoclimatici, porter & orombelli (1982) hanno stimato per il lgm (last glacial maximum) del versante italiano del monte bianco una ela genericamente inferiore a 2400 m. successivamente, utilizzando il metodo aar (accumulation area ratio) con aar = 0,67, sono state calcolate la ela media della piccola età del ghiaccio (peg; anno 1820 ca.) a 2845 ±165 m e la ela media attuale (anno 1975) di 3015 ±197 m (vanuzzo, 2001). 4. caratteri sedimentologici e morfologici delle successioni pleistoceniche i vari tipi di depositi glaciali sono stati classificati in base alla posizione rispetto al ghiacciaio (subglaciale, supraglaciale, di margine glaciale e proglaciale), all’ambiente di sedimentazione (subacqueo o terrestre) e al processo sedimentario (allogamento, fusione, sublimam.g. forno, f. gianotti & g. racca 109 zione, deformazione e colata gravitativa) (goldthwait & matsch, 1988). i depositi legati al ghiacciaio principale sono riferibili in netta prevalenza a facies di margine glaciale, interpretabili come till di colata gravitativa (ice-marginal gravity flowtill): sono ghiaie sabbioso-limose con blocchi, poco selezionate e normal-addensate, solitamente a supporto di matrice e con una grossolana stratificazione inclinata di 10°-25° verso il fianco esterno delle morene, di cui costituiscono l’ossatura; i clasti, fortemente eterometrici, sono prevalentemente subangolosi. alla stessa posizione marginale sono anche associati numerosi lembi di depositi fluvioglaciali e glaciolacustri, che costituivano il riempimento di depressioni sviluppate tra il ghiacciaio e il versante: danno luogo a superfici pianeggianti sospese a più livelli sul fianco interno dei cordoni morenici o direttamente sul versante roccioso (terrazzi di kame). i primi (ice-marginal glaciofluvial deposits) sono rappresentati da ghiaie sabbiose con blocchi, a supporto di clasti, da grossolanamente a ben stratificate con locali accenni di stratificazione incrociata concava; i ciottoli, eterometrici, sono ancora subangolosi ma con spigoli sensibilmente smussati; la matrice è prevalentemente sabbiosa, con tessitura medio-grossolana. i secondi (ice-marginal glaciolacustrine deposits) sviluppano alternanze decimetriche di sabbie fini, caratterizzate da laminazione piano-parallela o incrociata concava (con ripples, climbing ripples e laminazione a drappeggio), di sedimenti eterometrici non stratificati (diamicton) e di ghiaie fini, con stratificazione primaria suborizzontale. spesso mostrano una marcata inclinazione degli strati (fino a 60° e oltre), legata a fenomeni di deformazione glaciotettonica o di collasso da ritiro glaciale, e laminazione convoluta, dovuta a deformazioni sinsedimentarie (soft sediment deformations). risultano subordinati, almeno in affioramento, i depositi di posizione subglaciale, corrispondenti a till di fusione (subglacial melt-out till) e, in misura minore, a till di allogamento (lodgement till). i diversi depositi sono caratterizzati da discreta varietà composizionale, rappresentativa dell’esteso bacino della dora baltea (fig. 4). la composizione petrografica dei clasti mostra però una spiccata differenziazione, considerando facies con differente posizione rispetto al ghiacciaio, marginale o subglaciale. i depositi di margine glaciale comprendono una maggioranza di clasti (oltre il 90%) di gneiss e micascisti eclosignificato paleoclimatico dei rapporti tra ... fig. 4 composizione petrografica eterogenea dei clasti dei depositi glaciali legati alla valle principale, che rispecchia la varietà litologica del vasto bacino della dora baltea (till di colata di margine glaciale dell’allogruppo di s. michele-borgo, donato). heterogeneous petrographic constitution of the main valley glacier sediments, testifying the lithologic variety of the wide dora baltea basin (s. michele-borgo allogroup flowtill, donato). 110 gitici a glaucofane, ortogneiss eclogitici, eclogiti e glaucofaniti, metagraniti, gneiss “minuti” in facies scisti verdi, quarziti di vena e rari marmi dolomitico-calcitici saccaroidi di colore bianco: questo insieme litologico è indicativo di una alimentazione prevalente dai litotipi della zona sesia-lanzo, affioranti estesamente nel tratto vallivo considerato (fig. 3). del tutto subordinati sono invece i clasti di litologie provenienti da altri complessi affioranti più a monte, tra i quali graniti, gneiss granatiferi, prasiniti, metagabbri e serpentiniti. i depositi subglaciali sono invece costituiti in netta prevalenza da clasti di litologie resistenti all’erosione, come serpentiniti, eclogiti, dioriti, quarziti e marmi, provenienti dall’intero bacino idrografico. nei pochi lembi affioranti di till di allogamento risultano particolarmente concentrate le serpentiniti, in piccoli ciottoli levigati, sfaccettati e, talvolta, striati. i depositi legati ai ghiacciai tributari sono più monotoni per quanto riguarda facies e composizione litologica. prevalgono i depositi più o meno ricchi di blocchi subangolosi, interpretabili come till di colata marginale, localmente costituenti morene laterali e più rari archi morenici frontali. la loro composizione litologica è ristretta ai litotipi locali riferibili al complesso dei micascisti eclogitici della zona sesia-lanzo (fig. 5), in cui si sviluppano interamente i bacini tributari. al contrario l’espressione morfologica risulta molto più significativa per i lembi legati al glacialismo locale (evidenti cordoni morenici sia laterali che frontali; fig. 5), rispetto a quelli del ghiacciaio balteo rappresentati in valle da lembi sottili e discontinui, morfologicamente poco diagnostici. nella carta geologica schematica (fig. 6) si è scelto di rappresentare in modo indifferenziato tutti i depositi come di margine glaciale, con l’eccezione dei principali affioramenti di till subglaciale per il bacino della dora baltea e di due significativi lembi fluvioglaciali proglaciali legati ai ghiacciai del chiussuma e del maroncello. 5. stratigrafia della successione pleistocenica 5.1 terminologia e metodo la ricostruzione stratigrafica si è basata sugli elementi raccolti tramite la fotointerpretazione e il rilevamento geologico di circa 55 km2, condotto alla scala 1:10.000 seguendo il metodo allostratigrafico (north american commission on stratigraphic nomenclature, m.g. forno, f. gianotti & g. racca fig. 5 i depositi dei ghiacciai tributari mostrano una costituzione petrografica monotona (micascisti eclogitici) e formano potenti accumuli morfologicamente bene espressi (morene laterali destre del ghiacciaio del chiussuma, alpi pian maglio a 1550 m). tributary glacier sediments show a monotonous petrographic constitution (eclogitic micaschist) and form significant moraines (lateral right moraines of the chiussuma glacier, pian maglio alpage at 1550 m). 1983). la successione pleistocenica è stata pertanto differenziata in alloformazioni, unità di valore stratigrafico che, in questo contesto, hanno significato essenzialmente climatico, comprendendo ognuna i depositi riferibili a una determinata glaciazione. esse sono a loro volta suddivisibili in allomembri, unità di ordine minore, comprendenti ognuno i depositi riferibili a uno stadio glaciale. i raggruppamenti di depositi glaciali individuati sono quindi fondamentalmente riconducibili a unità climatostratigrafiche. la climatostratigrafia si basa sulla dipendenza dei processi erosivo-sedimentari dai fattori climatici e tale rapporto è particolarmente stretto per i depositi glaciali. in particolare la climatostratigrafia alpina (orombelli & ravazzi, 1996; ravazzi, 2003) individua una serie di episodi glaciali (o glaciazioni), definibili come importanti eventi di espansione glaciale, separati da prolungati episodi di marcato ritiro delle masse glaciali (bini et al., 2004). sono invece definiti stadi (in inglese stadial) le oscillazioni climatiche minori all’interno di un episodio glaciale, che, modulate dai fattori locali, comportano riavanzate e stazionamenti del margine glaciale. il termine è stato ampiamente utilizzato per indicare le tappe dell'ultimo ritiro dei ghiacciai alpini nel tardoglaciale (19.000-11.500 anni cal. bp), denominate dalle località di fondovalle in cui sono stati individuati i rispettivi apparati morenici frontali (in parte già da penck & brückner, 1909): in ordine cronologico sono gli stadi gschnitz, clavadel/senders, daun, egesen e kromer/kartell. precedenti fasi di riavanzata glaciale, collocabili a oltre 18-19 cal ka bp alla fine del lgm, sono più problematiche e sono note come stadi bühl e steinach. le datazioni numeriche (radiocarbonio su resti lignei, isotopi cosmogenici su massi erratici e luminescenza su depositi fluvioglaciali) hanno individuato la fase di massima espansione glaciale a partire da 30.000 anni fa e l’inizio del ritiro glaciale ad almeno 20.000 anni fa. in particolare per l’italia settentrionale le datazioni 14c attestano due fasi di massima avanzata (26,5÷23 e 24÷21 cal ka bp) per l’lgm dell’anfiteatro del tagliamento, seguite da un primo stadio cataglaciale tra 21÷18,8 cal ka (monegato et al., 2007), mentre l’età minima della deglaciazione nell’anfiteatro morenico di ivrea è indicata da un’età di esposizione di 20,8±1,5 10be ka bp (gianotti et al., 2008). i primi tre stadi tardoglaciali (gschnitz, clavadel/senders, daun) sono stati riferiti all’intervallo 18÷15 ka e correlati con l’oldest dryas della climatostratigrafia nord-europea (precedente all’interstadio bølling fissato a 14,7 ka); lo stadio egesen, datato tra 13÷11,5 ka circa, è stato correlato allo younger dryas (post-bølling), mentre lo stadio kartell è stato collocato dubitativamente all’inizio dell’olocene (riferimenti in ivy-ochs et al., 2008). per correlare gli apparati morenici stadiali delle diverse valli alpine a quelli delle località-tipo, i vari studiosi hanno fatto ricorso a metodi morfostratigrafici (posizione relativa delle cerchie terminali; morfologia delle morene, con particolare riferimento al grado di rimodellamento e alla rielaborazione periglaciale), pedostratigrafici (grado di evoluzione dei suoli e di alterazione dei massi erratici) e climatostratigrafici (confronto tra le paleo-ela e soprattutto tra le differenze delle ela rispetto alle ela della “piccola età del ghiaccio”). nell’area di studio la distinzione stratigrafica dei depositi è avvenuta facendo ricorso a elementi pedostratigrafici e morfostratigrafici. i dati sono stati confrontati con quelli disponibili in letteratura: questi ultimi sono notevoli per l’anfiteatro morenico di ivrea (carraro, 1992; gianotti, 1993; baio & gianotti, 1996; gianotti, 2007; grosso, 2005; gianotti et al., 2008) e pressoché inesistenti per il settore vallivo (cfr. § 3). i depositi riferibili a differenti glaciazioni sono stati distinti in anfiteatro soprattutto attraverso la pedostratigrafia, che si basa sul confronto dei caratteri pedogenetici dei suoli superficiali (profondità e grado di alterazione; indici di colore dei suoli e dei loro colluvia). lo studio morfostratigrafico ha poi permesso di estendere nel settore a monte la suddivisione in alloformazioni già effettuata in anfiteatro e, inoltre, di effettuare un’ulteriore differenziazione dei depositi dell’ultimo episodio glaciale in subunità (allomembri) collegate a differenti stadi glaciali, sia per il ghiacciaio principale che per quelli tributari. la morfostratigrafia è la suddivisione di depositi in base alla correlazione delle forme primarie cui danno luogo. per la caratteristica capacità dei ghiacciai di edificare in breve tempo forme diagnostiche particolarmente evidenti e continue su vaste aree, la morfostratigrafia ha da sempre giocato un ruolo fondamentale nella ricostruzione stratigrafica di aree glacializzate nel quaternario. nel caso in esame ciò è avvenuto tramite l’individuazione di allineamenti di forme diagnostiche di margine glaciale, corrispondenti a cordoni morenici e a terrazzi di kame, in base alle quali è stato possibile effettuare una ricostruzione delle posizioni del margine glaciale in occasione dei successivi stazionamenti del ghiacciaio. come è noto, le morene laterali e frontali si formano nel corso di stazionamenti della massa glaciale con tendenza a una limitata espansione, accompagnati quindi da un aumento di spessore; i terrazzi di kame si formano invece durante stazionamenti del ghiacciaio con tendenza a un limitato o lento ritiro. i raggruppamenti di depositi così ottenuti, distribuiti ognuno tra due allineamenti successivi di forme, sono da considerarsi unità morfostratigrafiche, strettamente dipendenti da eventi climatici, e permettono una dettagliata suddivisione in unità stratigrafiche. un dato allomembro è quindi costituito dai depositi sedimentati nel corso di uno stadio glaciale, che disegnano l’allineamento di forme altimetricamente più elevato e longitudinalmente più distale, e dai lembi di depositi abbandonati durante il successivo ritiro, distribuiti in posizione via via più interna e a quota inferiore, spesso privi di evidenza morfologica (gianotti, 2007). nel presente lavoro con “stadio di acme glaciale” si indica il momento in cui il ghiacciaio realizza la massima avanzata nel corso di un episodio glaciale, seguito da vari “stadi cataglaciali”, nel corso di ognuno dei quali avviene un sensibile stazionamento del margine glaciale (che verosimilmente fa seguito a una riavanzata), nell’ambito di un più generalizzato ritiro. in conclusione gli elementi geologici, pedostratigrafici e morfostratigrafici a disposizione hanno consentito una differenziazione in dieci unità stratigrafiche di varia tipologia (allostratigrafiche e morfostratigrafiche) e rango gerarchico (allogruppi, alloformazioni, e allomembri, di seguito indicati rispettivamente con ag, af e am), otto delle quali nel bacino della dora baltea e 111significato paleoclimatico dei rapporti tra ... due nel complesso dei bacini tributari. le diverse unità non comprendono però i depositi subglaciali, difficilmente differenziabili dal punto di vista stratigrafico, che vengono provvisoriamente trattati a parte come un’unica unità litostratigrafica. 5.2 unità geneticamente legate al ghiacciaio della dora baltea l’insieme dei dati raccolti, oltre a consentire una rappresentazione cartografica di dettaglio dei depositi e delle forme glaciali, che sarà oggetto di una specifica pubblicazione e che viene qui sintetizzata in fig. 6, ha permesso una più precisa definizione delle unità costituenti la successione legata al ghiacciaio principale e una migliore valutazione delle facies che le caratterizzano. l'ag di s. michele-borgo (1 in fig. 6a) rappresenta il termine più antico della successione investigata e comprende varie alloformazioni (dalla più antica: mongrando, montino, bornasco, zubiena, parogno e torrazzo), di cui solo le prime quattro affiorano nell'area di studio limitatamente al settore di anfiteatro. la successione è riferibile al termine del pleistocene inferiore e a parte del pleistocene medio (carraro et al., 1991). le varie unità sono rappresentate in modo indifferenziato in carta come allogruppo, per la marginalità della loro distribuzione e per il fatto che i corrispondenti depositi del settore vallivo, nel caso in cui risultassero conservati anche a monte dell’anfiteatro, sarebbero verosimilmente privi di elementi di distinzione stratigrafica. nel settore di anfiteatro i depositi, con spessore massimo di 30 m, formano brevi dorsali relitte derivanti dall’erosione di archi morenici di lobo glaciale, ampiamente rimodellate e troncate dalla profonda incisione del t. viona; si sviluppano tra gli 800-700 m e sono sospese fino a circa 500 m sull’attuale fondovalle alluvionale del f. dora baltea. i sedimenti, che corrispondono prevalentemente a depositi di margine glaciale s.l., sono interessati da suoli profondamente troncati di colore rosso (2.5yr 5/8), con patine di argilla spesse e continue, completa alterazione dei clasti e cementazione da parte degli ossidi di ferro. al margine interno questi sedimenti sono sepolti dai depositi dell’af della serra, che li sovrastano anche altimetricamente (fig. 6b). nel settore vallivo le superfici di appoggio in roccia si distribuiscono a quote superiori a 1300 m a monte e a 1100 m a valle, al di sopra del limite altimetrico raggiunto dalle espansioni glaciali successive; tuttavia non risultano conservare depositi glaciali, almeno in affioramento: ad esempio l’esteso piano di serrafredda, sito a 1100 m in posizione prossima allo sbocco vallivo, è modellato in roccia con una ridotta copertura di depositi gravitativi. l’af della serra (2 in fig. 6a) costituisce, nel settore di anfiteatro, una fascia continua e imponente di morene laterali subparallele, poco rimodellate, con altezza relativa di alcune decine di metri, e si distribuisce tra 940 m e 900 m a monte e tra 770 e 650 m a valle, sospesa fino a 700 m rispetto all’attuale fondovalle alluvionale. i depositi, la cui facies prevalente è il till di colata di margine glaciale, raggiungono lo spessore di 60 m circa a est di andrate; sono interessati da suolo di colore bruno-rossastro (7.5 yr 5/8), con spessore conservato di 2 metri e patine di argilla continue; i clasti sono prevalentemente poco alterati. nel settore vallivo l’unità costituisce invece lembi discontinui di depositi a formare cordoni laterali molto rimodellati, distribuiti esclusivamente nel tratto prossimo allo sbocco dell’incisione del t. maroncello tra 1100 e 1040 m, sospesi di oltre 800 m sull’attuale fondovalle alluvionale. l’af di piverone (3 in fig. 6a) nel settore di anfiteatro costituisce, in posizione immediatamente più interna e a quota minore rispetto all’af della serra, un’estesa successione di cordoni morenici laterali poco rilevati e discontinui con lunghezza di poche centinaia di metri e altezza massima di 10 m, bordati sul fianco interno da terrazzi di kame disposti a gradinata. nel settore vallivo questa unità raggruppa i depositi glaciali distribuiti tra 1060 m, a monte, e 600 m, a valle, costituenti lembi discontinui e morfologicamente mal espressi. lo spessore dei sedimenti è in genere di pochi metri nel settore vallivo, mentre in anfiteatro aumenta dalla quindicina di metri, a ne di andrate, a oltre 30 m, più a valle. sono prevalenti depositi di margine glaciale, tra cui till di colata, costituenti cordoni, e depositi glaciolacustri e fluvioglaciali, costituenti terrazzi di kame o riempimenti di scaricatori e di depressioni chiuse. al tetto dell’unità sono osservabili rari relitti di suolo, con spessore compreso tra 1 e 2 m, caratterizzato da un colore bruno-rossastro (7.5yr 6/8) e da una modesta alterazione dei clasti. molto più diffusi sono invece i prodotti colluviali con lo stesso indice di colore. l'af di ivrea (4-8 in fig. 6a) raggruppa i depositi che costituiscono le cerchie più interne dell’anfiteatro, sensibilmente smembrate dall’erosione fluviale o sepolte dai sedimenti lacustri e alluvionali della depressione interna dell’anfiteatro. i depositi, che raggiungono spessori metrici in valle e decametrici in anfiteatro, non mostrano in genere suoli in posto e sono formati da clasti poco alterati; sono invece interessati da un orizzonte c di ossidazione della matrice con spessore fino a 2 m, con colori bruno-giallastri (10yr 6/8). più frequenti sono i lembi di colluvium di suolo, con spessore di alcuni decimetri e colore bruno-rossastro 7.5yr 6/8. recenti datazioni con isotopi cosmogenici su massi erratici dei colli d’ivrea consentono di riferire l’af di ivrea al lgm e collocano il ritiro del ghiacciaio balteo dall’anfiteatro morenico ad almeno 20.8±1.5 10be ka (gianotti et al., 2008). l’af di ivrea è suddivisibile su base morfostratigrafica in una sequenza di allomembri, comprendenti ognuno i sedimenti glaciali deposti tra una fase di stazionamento del margine glaciale (stadio) e quella successiva. il primo allomembro (andrate) è riferibile allo stadio di acme glaciale dell’ultima glaciazione, mentre le unità successive (quintas, pavone, prà san pietro e torredaniele) sono riferibili ad altrettanti stadi cataglaciali, tutti collocabili ancora nel lgm. l’am di andrate (4 in fig. 6a) comprende depositi e forme collegati allo stadio di massima espansione del ghiacciaio nell’ultima glaciazione. nel settore di anfiteatro corrisponde al cordone noto in letteratura come “piccola serra”, che si sviluppa con lunghezza di 9 km nel settore compreso tra il cimitero di andrate e il castello di bollengo, di cui la carta comprende solo il tratto iniziale di circa 3 km. i depositi, prevalentemente till di colata, si distribuiscono in posizione immediatamente più interna e in una fascia altimetrica di poco 112 m.g. forno, f. gianotti & g. racca 113significato paleoclimatico dei rapporti tra ... fig. 6 a. schema geologico del versante sinistro della bassa valle della dora baltea, con evidenziate le successioni stratigrafiche legate al ghiacciaio principale (dora baltea) e ai ghiacciai tributari (chiussuma, viona e maroncello). b. profilo trasversale semplificato dell’area di studio, illustrante lo schema dei rapporti stratigrafici (da forno et al., 2005, mod.). nel settore vallivo le unità glaciali sono terrazzate e distribuite su una fascia altimetrica estesa. a.. geological sketch of the left side of the lower dora baltea valley: the stratigraphic successions linked with the main glacier (dora baltea) and with the tributary glaciers (chiussuma, viona and maroncello) are represented. b. transversal semplified cross section of the studied area, with the stratigraphic relationship between glacial units (from forno et al., 2005, mod.). in the valley sector the different glacial units are terraced on a wide altimetrical band. inferiore rispetto all’af di piverone, compresa tra 850 e 500 m, risultando sospesi fino a 600 m sull’attuale fondovalle alluvionale. nel settore vallivo è distribuita in lembi discontinui sviluppati tra 995 m a monte, in corrispondenza della morena di gorgiasso, e 800 m, a valle. l’espressione morfologica è rappresentata da piccoli cordoni morenici e lembi applicati al versante roccioso. l’am di quintas (5 in fig. 6a) rappresenta il primo termine della locale successione cataglaciale. in anfiteatro l’unità comprende diversi allineamenti di terrazzi di kame, i cui depositi sono applicati al fianco interno della piccola serra, con spessori inferiori alla decina di metri e distribuiti tra 700 e i 650 m, a monte, e tra 650 e i 600 m, a valle, risultando sospesi fino a circa 400 m rispetto all’attuale piana alluvionale. nel settore vallivo lembi discontinui di depositi formano ripiani terrazzati distribuiti tra 1000 m, a monte, e 850 m, a valle. l’am di pavone (6 in fig. 6a) rappresenta il secondo termine della locale successione cataglaciale. nell'ambito del settore in carta l'areale di distribuzione di questa unità, come anche delle successive, si può considerare limitato al solco vallivo. si sviluppa tra 900÷850 m, a monte, e 520÷450 m, a valle presso bienca, risultando sospesa rispetto all’attuale fondovalle alluvionale con un dislivello di circa 600 m, a monte e 250 m, a valle. si compone di pochi lembi discontinui e ridotti, tranne che a nomaglio dove sono conservati quattro segmenti di morena laterale. l'unità risulta prevalentemente costituita da depositi di margine glaciale di spessore metrico, in maggior parte interpretabili come till di colata. l’am di prà san pietro (7 in fig. 6a), penultimo termine della successione cataglaciale considerata, rappresenta lo stadio in seguito al quale si realizza il definitivo ritiro del ghiacciaio balteo dall’anfiteatro morenico d’ivrea. il limite esterno dell'unità è dato da un allineamento di morene poco rilevate, sviluppato tra prà san pietro a 475 m e la soglia che forma il fianco meridionale della piccola torbiera di bienca (390 m). sulle numerose rotture di pendenza del settore vallivo, distribuite in un’estesa fascia altimetrica compresa tra 800 e 450 m di quota sopra carema, sono conservati diversi lembi di depositi glaciali senza particolare espressione morfologica diagnostica. l’am di torredaniele (8 in fig. 6a) corrisponde all’ultimo termine della successione cataglaciale locale. il suo limite distale è individuato da un segmento di arco morenico frontale, che si innalza di una decina di metri sul fondovalle tra settimo vittone e carema (276 m) in corrispondenza dell’abitato di torredaniele, sito su un’emergenza del substrato roccioso in forma di dosso montonato. 5.3 unità geneticamente legate ai ghiacciai dei bacini tributari diffuse testimonianze glaciali sono state riconosciute anche nelle valli laterali, riferibili ai bacini dei torrenti chiussuma, maroncello e viona. nel bacino del viona è distinguibile un raggruppamento più antico (allogruppo di rionca), caratterizzato da una sensibile alterazione pedogenetica. non essendo emersi altri elementi di differenziazione stratigrafica, tutti gli altri depositi glaciali sono stati riuniti in una sola unità più recente (af di trovinasse): questa è riferibile al lgm in quanto le sue forme di modellamento e di accumulo sviluppate a quota più bassa intersecano nettamente i depositi dell’af di ivrea, legati al glacialismo principale. l’ag di rionca (9 in fig. 6a) raggruppa i depositi distribuiti sul versante destro della valle del t. viona in un'ampia fascia altimetrica, distinti in due gruppi di lembi sviluppati a 1200÷970 m e a 1400÷1300 m, separati da un settore più acclive modellato in roccia affiorante. l'ampia distribuzione di questi sedimenti e le diverse caratteristiche morfologiche dei lembi suggeriscono che siano riferibili a differenti episodi glaciali, da cui il nome di gruppo attribuito all'insieme. sono stati cartografati depositi di margine glaciale, con spessore plurimetrico, costituiti da blocchi di composizione litologica relativamente monotona (micascisti eclogiticoglaucofanici, ortogneiss e quarziti di vena della zona sesia-lanzo). allo sbocco della valle, a circa 920 m, questi depositi danno luogo a tre cerchie costituenti un piccolo apparato morenico frontale del ghiacciaio del viona, prossimo all'inizio della serra d’ivrea: il rapporto complessivamente eteropico e i dati pedostratigrafici (suolo di colore bruno-rossastro 7.5yr 5/6) supportano l’ipotesi che i depositi dell'anfiteatro terminale del viona siano coevi a quelli dell’af della serra. l'af di trovinasse (10 in fig. 6a) comprende depositi di margine glaciale, caratterizzati da minor grado di alterazione rispetto ai precedenti, diffusi in tutti i tre bacini tributari. nel bacino del viona questi depositi si distribuiscono tra i due piccoli circhi glaciali alla testata del bacino (2050 m) e l’incisione di fondovalle a 1050 m, dove un raggruppamento di morene latero-frontali e kame associati, circa 1,5 km a monte dell'anfiteatro terminale sopracitato, rappresentano verosimilmente la massima espansione del ghiacciaio del viona nell’ultimo episodio glaciale (lgm) e sono quindi correlabili con l’am di andrate. il più esteso bacino del chiussuma conserva depositi glaciali in tutta la sua estensione, a partire dai notevoli circhi glaciali a gradinata (balmenegre, mombarone e revorsetto) presenti nella parte superiore del bacino (tra i 1800 e i 2300 m), fino a quote molto basse, alla confluenza con il fondovalle principale (circa 350 m). i depositi danno luogo a morene laterali con lunghezza massima di poche centinaia di metri e altezza di alcuni metri, particolarmente numerose e bene espresse nella parte alta del bacino (figg. 5 e 7); un complesso di morene laterali e un conoide fluvioglaciale con blocchi ciclopici si sviluppa allo sbocco sul fondovalle principale presso airale, ad appena una cinquantina di metri sopra l’attuale alveo del f. dora baltea (fig. 8). nel bacino del maroncello si osservano depositi di margine glaciale con composizione litologica particolarmente monotona (micascisti eclogitici e quarziti di vena) e con spessore modesto, in genere non superiore a pochi metri, che costituiscono morene di dimensioni ridotte. in particolare le morene laterali conservate a vernej (intorno ai 900 m) provano che anche questo piccolo bacino, nonostante la sua modesta estensione (2,6 km2), l'altimetria non elevata (quota massima 2179 m) e la sfavorevole esposizione (verso sw), abbia ospitato un ghiacciaio proveniente dalla confluenza di due piccoli ghiacciai di nicchia. allo stesso bacino sono inoltre da riferire i depositi fluvioglaciali attribuibili allo scaricatore sinistro del ghiacciaio del maroncello, 114 m.g. forno, f. gianotti & g. racca 115significato paleoclimatico dei rapporti tra ... fig. 7 arco morenico frontale nella parte alta del bacino del chiussuma (1840 m). end moraine in the high side of chiussuma basin (1840 m a.s.l.). fig. 8 le morene del ghiacciaio del chiussuma si estendono fino al fondovalle principale (350 m), dove intersecano i depositi legati a uno degli stadi glaciali più recenti del ghiacciaio balteo (am di torredaniele). the chiussuma glacier moraines reach the main valley floor (350 m a.s.l.): they cut the sediments linked with a more recent glacial stadial of the dora baltea glacier (torredaniele am). distribuiti tra i cordoni morenici dell’af della serra della valle principale. la cronologia degli stadi glaciali in cui si scandisce il glacialismo laterale può essere parzialmente ricostruita in base ai rapporti di intersezione e di eteropia di facies con le successioni del ghiacciaio principale (fig. 9). i depositi glaciali dei bacini del chiussuma e del maroncello sono attribuibili interamente, per quanto è dato sin’ora a conoscere, all’ultimo episodio glaciale, in quanto le loro morene terminali, sviluppate fino a bassa quota, intersecano i lembi del bacino principale appartenenti alle af della serra, di piverone e di ivrea, quest’ultima riferibile al lgm. in particolare le morene terminali del ghiacciaio del chiussuma hanno rapporto di eteropia con l’am di torredaniele della successione glaciale principale, risultando pertanto ad essa correlabili. le morene terminali del ghiacciaio del maroncello intersecano invece i lembi dell’am di andrate, risultando quindi più recenti: la loro posizione, strettamente confinata nella fascia altimetrica in cui si distribuisce l’am di quintas, indica come il distacco della fronte glaciale dal ghiacciaio balteo sia avvenuta durante lo stadio di quintas e non successivamente, considerato che la tendenza generale è quella del regresso glaciale. nel bacino del viona la netta separazione planoaltimetrica tra i depositi dell’af di trovinasse e quelli dell’am di andrate, nonché l’interposizione di un apparato morenico terminale più antico allo sbocco della valle, provano come nel corso del lgm il ghiacciaio del viona non giungesse a saldarsi con quello principale, come invece risulta essere avvenuto nel corso del precedente episodio glaciale serra. 5.4 la successione post-glaciale comprende depositi di origine sia gravitativa che legata al sistema idrografico, sedimentati in seguito al ritiro del ghiacciaio balteo del lgm e ormai scollegati dai suoi apporti. al periglacialismo del tardoglaciale (se non ancora del lgm) è da riferire la formazione di rock glacier attualmente relitti, distribuiti sopra i 1200 m nel bacino del chiussuma. i loro depositi sono costituiti da blocchi di micascisti eclogitici, con subordinati quarziti di vena ed eclogiti, mescolati a una scarsa matrice sabbiosa poco selezionata, costituenti lobi, con tracce di creste concentriche, prodotti dalla deformazione periglaciale a spese sia di depositi glaciali dell’af di trovinasse sia di 116 m.g. forno, f. gianotti & g. racca fig. 9 profilo morfostratigrafico dell’area in esame: rapporti di intersezione tra le morene dei ghiacciai tributari (chiussuma, maroncello e viona) e quelle legate al ghiacciaio principale (dora baltea). l’af di bornasco (bor), appartenente all’ag di san michele-borgo, si distribuisce in posizione più esterna e a quota inferiore rispetto all’af della serra. viene indicata anche l’am di germano, non differenziata nell’area di studio. la morena di chanton, appartenente all’af della serra, si trova in realtà sull’opposto versante vallivo destro. morphostratigraphic cross section of the examined area: intersection relationship between the tributary glaciers moraines (chiussuma, maroncello and viona) and the main glacier moraines (dora baltea). the bornasco af (bor) of the san michele-borgo group extends in more external and lower positions than those reached by the serra moraines. also the germano am, not recognized in the studied area, is shown. chanton moraine, belonging to the serra af, is actually located on the opposite (right) side of the valley. accumuli detritici. all’interno del circo glaciale sudoccidentale della colma di mombarone è conservato un rock glacier dalla forma particolarmente bene espressa, la cui fronte è scesa a saldarsi con un arco morenico frontale tardoglaciale poggiante sulla soglia del circo: lo sbarramento prodotto ha determinato la formazione di un lago o l’aumento di livello di un precedente lago di circo, poi colmato, di cui l’attuale lago di mombarone (q. 1910) costituisce il relitto (fig. 10). alcune superfici orizzontali sviluppate tra le morene o tra le morene e il versante svelano la presenza di bacini glaciolacustri marginali, sopravvissuti anche in seguito al ritiro glaciale e infine colmati da deposti lacustri e palustri: questi ultimi sono costituiti da sabbie fini limoso-argillose di colore grigiastro o nerastro (gyttja) e da livelli di torbe, di spessore decimetrico. l’esempio più importante è rappresentato dalla successione a gradinata di bacini intermorenici confinati tra l’af della serra e le morene dell’af di piverone, che termina nella vasta piana di salamia ad andrate, confinata a sua volta tra le morene dell'af di piverone e l’am di andrate. nel fondovalle principale i depositi alluvionali del f. dora baltea, prevalentemente sabbiosi, formano un’ampia superficie debolmente incisa dal corso d'acqua, che si salda direttamente alla base dei ripidi versanti rocciosi senza interposizione di terrazzi: questa morfologia si spiega con una prolungata tendenza al sovralluvionamento sull’intero fondovalle nel tratto tra pont saint martin e borgofranco d’ivrea. i depositi legati ai corsi d'acqua tributari costituiscono invece ridotti conoidi alluvionali, tra i quali quello telescopico del t. chiussuma i cui depositi attuali sono incastrati entro quelli del conoide fluvioglaciale pleistocenico (fig. 6a). potenti ed estese falde detritiche a grandi blocchi di micascisti sono strettamente legate al profondo stato di fratturazione e allentamento del substrato roccioso, specialmente all’intersezione tra la valle principale e alcune dorsali rocciose che separano i vari bacini tributari. 6. ricostruzione climato-stratigrafica nell’area esaminata le alloformazioni riunite nell’ag di s. michele-borgo sono riferibili alle prime glaciazioni del pleistocene inferiore-medio; le successive alloformazioni della serra, di piverone e di ivrea sono invece riferibili ai tre episodi glaciali più recenti, occorsi a partire dalla fine del pleistocene medio (gianotti, 2007). per quanto riguarda l’episodio glaciale più recente (af di ivrea, correlabile al lgm e al successivo tardoglaciale: 30÷11,5 ka bp), l’individuazione nell’area di studio di 5 allomembri consente di delineare una storia evolutiva assai più dettagliata che non per le precedenti unità (fig. 9). in particolare, allo stadio di acme dell'ultimo episodio glaciale è riferibile l’am di andrate, con edificazione nel settore laterale sinistro dell’ami di una morena 117significato paleoclimatico dei rapporti tra ... fig. 10 il rock glacier del circo glaciale del lago di mombarone. rock glacier in the mombarone lake glacial cirque. elevata e continua (piccola serra). durante lo stadio di andrate i ghiacciai tributari del chiussuma e del maroncello confluivano in quello principale, mentre la fronte di quello del viona si attestava 200 m più in alto. gli al lomembri alt imetricamente più bassi (quintas, pavone, prà san pietro e torredaniele) sono legati a quattro successivi stadi cataglaciali: questi sono molto probabilmente riferibili ancora tutti al lgm piuttosto che al tardoglaciale, in base all’età minima di esposizione di 20,8±1.5 ka 10be bp di un masso erratico deposto sui colli d'ivrea tra gli stadi di pavone e di prà san pietro (gianotti et al., 2008). gli allomembri di pavone e di torredaniele, i cui limiti distali sono marcati prevalentemente da morene, rappresentano stazionamenti meglio definiti, probabilmente successivi a riavanzate; gli allomembri di quintas e di prà san pietro, con prevalenti terrazzi di kame, corrispondono a stazionamenti meno marcati e duraturi. tra l’edificazione delle due cerchie maggiori (stadi di andrate e di pavone) il ghiacciaio balteo si ritirò velocemente di 8-9 km verso monte (da strambino a ivrea-pavone), come indica la pressoché totale mancanza di depositi glaciali sui rilievi rocciosi tra pavone e bellavista; tale ingente arretramento della fronte glaciale fu interrotto solo dallo stadio di quintas (gianotti, 2007). durante lo stadio di quintas il ghiacciaio tributario del maroncello si separò dal ghiacciaio balteo. l’am di prà san pietro (qui considerato insieme al successivo am di germano, distinto solo più a valle e ancora da investigare nel dettaglio) materializza lo stadio dell'ultimo episodio glaciale in seguito al quale il ghiacciaio ha abbandonato definitivamente l’ami. il suo limite distale è marcato da un allineamento di lembi (morene e kame) lungo il ciglio della scarpata rocciosa con cui i colli dioritici si innalzano sulla piana della dora baltea; queste evidenze indicano una posizione della fronte glaciale da ricercarsi in un settore compreso tra banchette (ivrea) e montalto dora sotto i depositi alluvionali del f. dora baltea. lo sviluppo altimetrico dei depositi dell’am di prà san pietro sul versante vallivo (distribuiti su circa 400 m di dislivello) indica che, in seguito allo stazionamento che definisce il limite superiore e distale dell’unità, la fronte del ghiacciaio balteo si produsse in un ingente ritiro: la mancanza di evidenti forme di margine glaciale a monte dell’allineamento descritto fa ipotizzare un ritiro relativamente lento, di almeno 9 km sul fondovalle, senza stazionamenti marcati o riavanzate, verosimilmente in risposta a una maggiore oscillazione climatica. il ritiro si concluse a monte della posizione dell’arco morenico frontale di torredaniele: quest’ultimo, generato da una successiva riavanzata della fronte glaciale, rappresenta l’ inizio del successivo stadio di torredaniele. durante lo stadio di prà san pietro il ghiacciaio tributario del chiussuma confluiva ancora in quello della dora baltea; la loro separazione si realizzerà nel corso dello stadio di torredaniele. 7. linea di equilibrio durante il lgm 7.1 terminologia, metodi di calcolo e applicazioni delle ela la linea di equilibrio (ela equilibrium line altitude) è il luogo in cui il bilancio di massa di un ghiacciaio risulta uguale a zero, dove cioè gli apporti sono compensati dalle perdite. l’ela, espressa da una quota s.l.m., rappresenta un ottimo indicatore della variabilità climatica, in quanto è il risultato complessivo e quantificabile dei differenti processi che regolano l’alimentazione e l’ablazione glaciale, primi tra i quali le precipitazioni e la temperatura media estiva. per calcolare le paleo-ela si utilizzano numerosi metodi: quello del “rapporto tra area di alimentazione e area totale” (aar – accumulation area ratio; meier & post, 1962) e quello del “rapporto di bilancio” (br – balance ratio; furbish & andrews, 1984) risultano tra i più impiegati nella letteratura recente e necessitano entrambi della ricostruzione della superficie del ghiacciaio. il metodo aar, con un rapporto tra area di ablazione e area totale del ghiacciaio di 0,67, fu originariamente calibrato su un’ampia casistica di ghiacciai delle alpi europee e dunque risulta il più utilizzato nell’area alpina (riferimenti in ivy-ochs et al., 2008). l’interesse del calcolo delle paleo-ela risiede in due tipi di utilizzo: a scopo di correlazione stratigrafica di apparati morenici stadiali e per la determinazione di parametri paleoclimatici quali le temperature medie estive e le precipitazioni medie annue proprie di un particolare stadio glaciale. le correlazioni tra apparati morenici di bacini diversi sono eseguite confrontando le differenze di quota tra la paleo-ela e la corrispondente ela della peg oppure di quella attuale. per il lgm della regione alpina centrale sono stati calcolati valori di abbassamento delle ela, rispetto alle ela della peg, di 1200 m (haeberli, 1991; maisch, 1982) o compresi tra 1000 m e 1500 m (van husen, 1997; keller & krayss, 2005). per il successivo tardoglaciale, basandosi sulle posizioni delle rispettive morene stadiali in alcune località-tipo delle alpi centro-orientali, si sono ottenute ∆ela di 650÷700 m per lo stadio gschnitz, di 400÷500 m per lo stadio clavadel/senders, di 400÷250 m per lo stadio daun, di 450÷180 m per le tre fasi dello stadio egesen e di 120÷60 m per lo stadio/i kromer/kartell (riferimenti in ivy-ochs et al., 2006; 2008). come esempio di applicazione nell’alto bacino della dora baltea (fig. 3), confrontando gli abbassamenti altimetrici delle paleo-ela rispetto a quelle attuali, porter & orombelli (1982) hanno correlato l’avanzata di courmayeur (∆ela = 450±50 m) allo stadio daun o, in alternativa, a una fase antica dell’egesen e l’avanzata di planpincieux (∆ela = 350±50 m) all’egesen delle alpi austriache. nei riguardi dell’uso della ela come indicatore paleoclimatico, il metodo più semplice ma grossolano converte la ∆ela in ∆t moltiplicandola per un tasso medio di abbassamento della temperatura con l’altitudine (porter, 2001). sono inoltre in uso relazioni empiriche tra valori di precipitazioni e di temperatura, derivate da misurazioni dirette di bilancio di massa dei ghiacciai: ad esempio in regioni con precipitazioni abbondanti l’equazione di kuhn (1989) tiene anche conto della variazione delle precipitazioni, di umidità e della perdita di calore con l’altitudine. 7.2 calcolo della ela dei ghiacciai locali nel lgm per i ghiacciai tributari dell’area esaminata, ora del tutto scomparsi, si è proceduto al calcolo della quota delle rispettive antiche linee di equilibrio (paleoela). 118 m.g. forno, f. gianotti & g. racca al fine di operare un confronto con i dati disponibili dalla letteratura (cf. § 3), per il calcolo delle ela del lgm dei ghiacciai del chiussuma, del viona e del maroncello si è utilizzato il medesimo metodo aar già impiegato per i ghiacciai valdostani della peg (vanuzzo, 2001) e con lo stesso rapporto (aar = 0,67), per il quale la ela corrisponde all’isoipsa che divide l’area occupata dal ghiacciaio in 2/3 di bacino alimentatore e 1/3 di bacino ablatore (fig. 11). il margine del settore di ablazione è individuato dalle creste delle morene più distali riconosciute; il margine del settore di alimentazione è invece segnato dagli eventuali lembi di depositi glaciali più esterni e soprattutto dalle trimline riconoscibili nei circhi glaciali. nel caso dei ghiacciai del chiussuma e di maroncello, essendo le morene più distali posteriori allo stadio di acme del ghiacciaio balteo (cf. § 5.3), anche le ela calcolate sono riferibili a un momento successivo all’acme del lgm e pertanto non sono quelle potenzialmente più basse. anche il margine ricostruito del settore di alimentazione deve pertanto venire ridotto rispetto a quello massimo, per tener conto di una sua, sia pur modesta, diminuzione di volume e dunque di estensione areale. il bacino del viona (circa 8,6 km2 con chiusura a priat) è una valle lunga e relativamente stretta, assai incisa, allungata in senso n-s, che presenta alla testata due circhi di piccole dimensioni con soglia intorno ai 2060 m, entrambi esposti a sud: essa ospitò un ghiacciaio vallivo che, insieme a un suo tributario, si abbassò fino a q. 1050 m, raggiungendo nel lgm la lunghezza di 4,6 km e larghezza di 1,5 km su un’area di 4,7 km2. per i l ghiacciaio del viona si ottiene una ela di 1535 m s.l.m. nello stadio di acme glaciale. il bacino del chiussuma (13,5 km2) è completamente differente dal precedente: esposto mediamente verso wsw, nella parte medio-alta esso è costituito da tre ampi valloni, che fanno capo a numerosi circhi di dimensioni ragguardevoli, sviluppati al di sopra dei 1800 m di quota ed esposti in maggioranza verso nw; nella parte bassa del bacino i vari rami confluiscono in una sola incisione profonda e acclive (fig. 12). questo bacino ospitò un ragguardevole ghiacciaio vallivo, che si saldava a quello principale balteo e che successivamente, durante la fase di ritiro, portò la propria fronte fino al fondovalle principale a q. 350 m circa, percorrendo una distanza di 7 km con una larghezza massima di 2,5 km ed estensione di 11,7 km2. per il ghiacciaio del chiussuma la ela risulta di 1480 m s.l.m. in un momento correlabile allo stadio di torredaniele. infine il bacino del maroncello non costituisce una vera e propria valle, ma solo una concavità del ripido versante sw del m. la torretta. qui tuttavia si poterono formare un paio di piccoli ghiacciai di nicchia che, nonostante la sfavorevole esposizione verso sw, si svilupparono unendosi in una vera e propria lingua glaciale saldata al ghiacciaio balteo intorno a 950 m di quota; nella fase di ritiro il ghiacciaio tributario potè abbassarsi sino alla quota di almeno 900 m, raggiungendo una lunghezza di 2,7 km, larghezza di 900 m e superficie di 1,3 km2. la ela misurata per il ghiacciaio del maroncello è di 1430 m s.l.m. durante uno stadio correlabile a quello di quintas (tab. 1). rispetto alla ela relativa alla peg calcolata come media per l’intero bacino valdostano, attestata a 2845 ±165 m (vanuzzo, 2001), gli innalzamenti di ela tra lgm e peg risultano perciò compresi tra 1415 m (ghiacciaio del maroncello) e 1310 m (ghiacciaio del viona). effettuando invece il confronto con il gruppo glaciale attuale più prossimo all’area esaminata (cervino-monte rosa), caratterizzato da ela sensibilmente più elevate di quelle medie dell’intera valle d’aosta (ela-peg = 2903 ±170 m; ela anno 1975 = 3099 ±225 m) (vanuzzo, 2001), i valori di ∆ela vanno aumentati conseguentemente di una cinquantina di metri. 8. conclusioni nel settore vallivo l’individuazione di allineamenti di forme di margine glaciale (morene e terrazzi di kame) legate al ghiacciaio della dora baltea costituisce la base per raggruppare i diversi lembi di depositi glaciali in unità morfostratigrafiche. i depositi, distribuiti in 119significato paleoclimatico dei rapporti tra ... fig. 11 ricostruzione dei ghiacciai pleistocenici dei bacini tributari del t. chiussuma, maroncello e viona, con l’indicazione delle ela calcolate con il metodo aar: sono rappresentate in bianco e in grigio chiaro le aree corrsipondenti al bacino alimentatore e ablatore. pleistocene glaciers reconstruction of the chiussuma, maroncello and viona tributary basins: the elas, calculated with the aar method, are indicated. the alimentation and the ablation zones are represented in white and light grey colour, respectively. modo più o meno discontinuo su un’ampia fascia altimetrica del versante, non potrebbero altrimenti venire stratigraficamente differenziati. tali suddivisioni hanno significato climatico, poiché i loro limiti sono riconducibili agli stadi di stazionamento di un ghiacciaio che, per le sue dimensioni, doveva essere fortemente controllato dal clima regionale e globale. in questo modo i limiti tra le differenti unità allostratigrafiche, distinte nel settore di anfiteatro su base geologica e pedostratigrafica, possono venire tracciati anche nel settore vallivo: nel caso specifico soprattutto le maggiori morene laterali conservate sui versanti (in 120 m.g. forno, f. gianotti & g. racca fig. 12 nel bacino del chiussuma si sviluppava la lingua glaciale tributaria più estesa, alimentata da diversi circhi, i cui depositi si estendono fino a bassa quota (circa 350 m). the widest tributary glacier developed in the chiussuma basin and was fed by different cirques: the glacial sediments extend to a very low elevation (about 350 m a.s.l.). tab. 1 dati sull’altitudine della linea di equilibrio (ela) per i ghiacciai tributari della bassa valle della dora baltea durante differenti stadi del lgm, calcolate con rapporto aar=0,67 e confrontate con i valori medi regionali (da vanuzzo, 2001) della ela della piccola età del ghiaccio (ela-peg = 2845 ±165 m) e della ela attuale (3015 ±197 m). equilibrium line altitude (ela) of the lower dora baltea valley tributary glaciers during different lgm stadials, calculated with aar = 0,67 and compared with the regional mean values (from vanuzzo, 2001) of the little ice age ela (lia ela = 2845 ±165 m) and the modern ela (3015 ±197 m). particolare di chanton e di gorgiasso) rappresentano fondamentali elementi di correlazione tra glacialismo vallivo e anfiteatro morenico di ivrea. la ricostruzione stratigrafica permette inoltre di ottenere una correlazione di dettaglio con le successioni delle valli laterali. tre bacini tributari di sinistra (chiussuma, maroncello e viona) hanno sviluppato ghiacciai vallivi abbastanza estesi da interagire con il ghiacciaio principale. dalla posizione e dai reciproci rapporti di interdigitazione dei depositi e di intersezione delle forme dei bacini laterali con quelli del bacino principale, si desume che durante il lgm (i) il ghiacciaio del viona non arrivò a saldarsi con quello della dora baltea, (ii) il ghiacciaio di maroncello si staccò dal ghiacciaio balteo nel corso del primo stadio cataglaciale (stadio di quintas) e (iii) il ritiro dal fondovalle principale del ghiacciaio del chiussuma si realizzò contemporanenamente a quello del ghiacciaio balteo nel corso del quarto stadio cataglaciale (stadio di torredaniele) distinguibile nel settore di studio. un’immediata applicazione dei dati stratigrafici, ottenuti tramite il rilevamento, consiste nella ricostruzione della forma ed estensione di ghiacciai ora del tutto scomparsi, al fine di calcolare le rispettive paleo-ela nel corso dei primi stadi di riavanzata glaciale successivi all’ultima massima espansione glaciale. dalle paleoela si possono infine ottenere i dati paleoclimatici fondamentali (temperature medie e precipitazioni) relativi alle fasi in cui si scandisce il lgm. il contesto climatico e cronologico è tanto più interessante, in quanto la seconda parte del lgm è un intervallo poco indagato in letteratura, collocandosi tra le più studiate fasi di massima espansione glaciale (max lgm) e la classica successione delle riavanzate del tardoglaciale. il calcolo delle ela durante il lgm per diversi ghiacciai tributari del settore indagato, integrato da analoghi calcoli effettuati sul versante destro (gianotti, 2007), suggerisce che piccole masse glaciali poterono già formarsi a partire dai 1500 m di quota (localmente anche a quote inferiori) anche su versanti sfavorevolmente esposti e mantenersi anche nei primi stadi del lgm. i valori dell’innalzamento dell’ela tra lgm e peg (tra 1310 e 1415 m) sono sensibilmente più elevati rispetto a quelli riportati in letteratura per la regione alpina centrale, compresi tra 1000 e 1200 m, benché siano stati proposti valori massimi di ∆ela fino a 1500 m (riferimenti in ivy-ochs et al., 2008). questa significativa discrepanza tra i due gruppi di dati deriva dal fatto che quelli qui presentati sono confronti tra un valore medio regionale e un dato puntuale locale, seppure entrambi calcolati con lo stesso rapporto aar. il metodo utilizzato assume che il rapporto dei bilanci di massa sul ghiacciaio sia costante, presupposto vero per i bilanci influenzati solo dal clima regionale. il rapporto di bilancio varia invece nei casi in cui esso venga anche influenzato da topografia, attività valanghiva, effetti del vento e copertura detritica, fattori spesso importanti per i ghiacciai alpini di dimensioni mediopiccole, come nei tre casi in esame. la considerevole influenza della topografia e dell’esposizione nel caso di ghiacciai minori è attestata dal fatto che la ela calcolata per piccoli ghiacciai di nicchia esposti a nord presenti sul versante vallivo destro (opposto a quello esaminato) della bassa valle arriva sino a 1000 m (gianotti, 2007). dunque le differenze massime di ∆ela provengono da piccoli bacini con un forte controllo climatico locale (esposizione verso nord) e morfologico (elevata acclività). invece valori di ∆ela (intorno ai 1300 m) confrontabili con quelli regionali alpini sono forniti dal bacino del viona, che ha morfologia più simile a quella delle grandi valli alpine, benchè con estensione di un ordine di grandezza minore. il presente lavoro rappresenta un primo approccio al calcolo delle paleo-ela di ghiacciai estinti di questo settore delle alpi. risultati più significativi potranno derivare dall’applicazione e dal confronto di metodi (quali ad esempio il metodo br; furbish & andrews, 1984) che tengano conto dell’ipsometria delle paleosuperfici glaciali. lavori citati arobba d., calderoni g., caramiello r., carraro f., giardino m. & quagliolo p. (1997) palynological and radiometric evidence of a last glacial-interstadial from peat sediments in the ivrea morainic amphitheatre (nw-italy). geologia insubrica, ser. 2, 2, 143-148. baggio p. (1965) caratteri stratigrafici e strutturali del canavese s.s. nella zona di montalto dora. mem. ist. min. geol. un. padova., 25, 1-25. baio m. & gianotti f. (1996) studio geologico e giacimentologico dell’area della “bessa” (biella, italia). geologia insubrica, 1 (1-2), 29-48. baretti m. (1866) i ghiacciai antichi e moderni. tesi di laurea in scienze naturali, università di bologna, candeletti, torino. biino g. & compagnoni r. (1989) the canavese zone between the serra d’ivrea and the dora baltea river (western alps). eclogae geol. helv., 82 (2), 413-427. bini a., borsato a., carraro f., carton a., corbari d., cucato m., monegato g. & pellegrini g. b. (2004) definizione di alcuni termini in uso nella cartografia dei depositi quaternari continentali in ambito alpino. il quaternario, it. journ. quatern. sc., 17, 75-82. bortolami g., carraro f., friz c., govi m. & sacchi r. (1966) foglio 43 “biella” della carta geologica d’italia alla scala 1:100.000. iiª ed., serv. geol. it., roma. bruno l. (1877) i terreni costituenti l’anfiteatro allo sbocco della dora baltea. tip. f.l. curbis, ivrea, 65 pp. carraro f. (1992) la zona pedemontana da ivrea ad arona. depositi quaternari. in: dal piaz g. v. (ed.), le alpi dal monte bianco al lago maggiore. soc. geol. it., guide geologiche regionali, 3 (a), 186209, bema, milano. carraro f. & petrucci f. (1969) carte géologique de la plaine du piémont à l’échelle du 1:400.000e. viii congrés inqua, paris. carraro f., medioli f. & petrucci f. (1975) geomorphological study of the morainic amphitheatre of ivrea, northwest italy. bull. r. soc. new zealand, 13, 89-93, wellington. carraro f., lanza r., perotto a. & zanella e. (1991) l’evoluzione morfologica del biellese occidentale 121significato paleoclimatico dei rapporti tra ... durante il pliestocene inferiore e medio, in relazione all’inizio della costruzione dell’anfiteatro morenico d’ivrea. boll. museo reg. sc. nat. torino, 9 (1), 99-117. compagnoni r., dal piaz g. v., hunziker j. c., gosso g., lombardo b. & williams p. f. (1977) the sesia-lanzo zone, a slice of continental crust with alpine higt pressure-low temperature assemblage in the western italian alps. rend. soc. italiana mineralogia petrologia, 33, 281-334. forno m. g., gianotti f. & grosso f. (2005a) ârret 3. les collines d’ivrea. affleurements rocheux à modelé glaciaire à l’intérieur de l’ami (biò, borgofranco d’ivrea). in: deline et al. (ed.), le quaternaire des vallées alpines. cahiers de géographie, 3, 144-146, edytem, chambery. forno m. g., gianotti f. & grosso f. (2005b) il modellamento glaciale dei coll i diorit ici di ivrea . convegno naz. aigeo “montagne e pianure: recenti sviluppi della ricerca in geografia fisica e geomorfologia”, padova, 15-17 febbraio 2005, riassunti, 99-101. forno m. g., gianotti f. & grosso f. & pini r. (2007) stratigrafia della sequenza cataglaciale nei colli di ivrea e dati pollinici preliminari sui depositi lacustri di chiaverano (torino). il quaternario, it. journ. quatern. sc., 20 (2), 213-228. forno m. g., gianotti f. & racca g. (2003) il modellamento glaciale del settore di raccordo tra bassa valle d’aosta e anfiteatro morenico d’ivrea. geoitalia, 4° forum italiano di scienze della terra della fist (bellaria, 16-18 settembre 2003), riassunti, 111-113. forno m. g. & lucchesi s. (2000) caratterizzazione dei depositi glaciali del pleistocene inferiore-medio nel settore settentrionale dell’anfiteatro morenico d’ivrea (piemonte). il quaternario, it. journ. quatern. sc., 13 (1), 47-56. franchi s., mattirolo s., novarese v. & stella a. (1912) foglio 42 “ivrea” della carta geologica d’italia alla scala 1:100.000. r. uff. geol. it., roma. franchi s., mattirolo s., novarese v., stella a. & zaccagna d. (1908) carta geologica delle alpi occidentali à l’échelle 1:400.000e. r. uff. geol. it., roma. franchi s. & stella a. (1933) foglio 43 “biella” della carta geologica d’italia alla scala 1:100.000. r. uff. geol. it., roma. furbish d. j. & andrews j. t. (1984) the use of hypsometry to indicate long-term stability and response of valley glaciers to changes in mass transfer. journal of glaciology, 30, 199-211. gianotti f. (1993) ricostruzione dell’evoluzione quaternaria del margine esterno del settore laterale sinistro dell’anfiteatro morenico d’ivrea. tesi di laurea inedita in scienze geologiche, università degli studi di torino, 73 pp. gianotti f. (1996) bessa, paesaggio ed evoluzione geologica delle grandi aurifodine biellesi. quaderni di natura biellese, eventi e progetti ed., biella, 83 pp. gianotti f. (2007) stratigrafia dell'anfiteatro morenico di ivrea. tesi di dottorato di ricerca inedita, università degli studi di torino, 266 pp. gianotti f., forno m. g. & ivy-ochs s. (2006) new cronological and stratigraphical data on the ivrea amphitheatre (piedmont, italy). in: pini r. & ravazzi c. (eds.) quaternary stratigraphy and evolution of the alpine region in the european and global framework. meeting of inqua-seqs, milano, 11-15 september 2006, abstracts, 110112. gianotti f., forno m. g., ivy-ochs s. & kubik p. w. (2008) new chronological and stratigraphical data on the ivrea amphitheatre (piedmont, nw italy). quaternary international, 190, 123-135. goldthwait r.p. & matsch c. l. (1988) genetic classification of glacigenic deposits. taylor and francis, balkema, rotterdam, 304 pp. grosso f. (2005) ricostruzione dell’evoluzione geologica pleistocenica dei colli d’ivrea. tesi di laurea inedita in scienze geologiche, università degli studi di torino, 117 pp. haeberli w. (1991) zur glaziologie der letzleiszeitlichen alpenvergletscherung. in: frenzel b. (ed.), klimageschichtliche probleme der letzten 130000 jahre. paleoklimaforschung, 1, 409-419. keller o. & krayss e. (2005) der rhein-linth gletscher im letzen hochglazial. 1. teil: einleitung: aufbau und abschmelzen des rhein-linth gletschers im oberen würm. vierteljahresschrift der naturforschenden gesellscheft in zürich, 150, 19-32. kuhn m. (1989) the response of the equilibrium line altitude to climate fluctuations: theory and observations. in: oerlemans j. (ed.), glacier fluctuations and climate change. kluwer academic publishers, the netherlands, 407-417. ivy-ochs s., kerschner h., kubik p. w. & schlüchter c. (2006) glacier response in the european alps to heinrich event 1 cooling: the gschnitz stadial. journal of quaternary sciences, 21 (2), 115-130. ivy-ochs s., kerschner h., reuther a., preusser f., heine k., maisch m., kubik p. w. & schlüchter c. (2008) chronology of the last glacial cycle in the european alps. journal of quaternary sciences, 23 (6-7), 559-573. maisch m. (1982) zur gletscher und klimageschichte des alpinen spatglazials. geographica helv., 37, 93-104. martins c. & gastaldi b. (1850) essai sur les terrains superficiels de la vallée du pô, aux environs de turin, comparés a ceux de la plaine suisse. bull. soc. gèol. france, ser. 2, 7, 554-605. meier m. f. & post a. s. (1962) recent variations in mass net budgets of glaciers in western north america. union géodésique et géophysique internationale, association internationale d’hydrologie scientifique, commission de neiges et de glaces. colloque d’obergurgl, 1018/09/1962, association internationale d’hydrologie scientifique, 58, 63-77. monegato g., ravazzi c., donegana m., pini r., calderoni g. & wick l. (2007) evidence of a two-fold glacial advance during the last glacial maximum in the tagliamento end moraine system (eastern alps). quaternary research, 68, 284–302. north american commission on stratigraphic nomenclature (1983) north american stratigraphic code. american association of petroleum geologists 122 m.g. forno, f. gianotti & g. racca bulletin, 67 (5), 841-875. orombelli g. & ravazzi c. (1996) the late glacial and early holocene: chronology and paleoclimate. il quaternario, it. journ. quatern. sc., 9 (2), 439444. penck a., bruckner e. & du pasquier (1894) le système glaciaire des alpes. guide congr. geol. int., zurich. bull. soc. sc. nat. neuchatel, 22, 86 pp. penck a. & bruckner e. (1909) die alpen im eiszeitalter. 3 voll., chr. herm. tauchnitz, leipzig, 1199 pp. porter s. c. & orombelli g. (1982) late-glacial ice advances in the western italian alps. boreas, 11, 125-140, oslo. porter s. c. (2001) snowline depression in the tropics during the last glaciation. quaternary science reviews, 20, 1067-1091. racca g. (2002) ricostruzione geologica quaternaria del settore sinistro della bassa valle della dora baltea tra carema e andrate. tesi di laurea inedita in scienze geologiche, università degli studi di torino, 82 pp. ravazzi c. (2003) an overview of the quaternary continental stratigraphic units based on biological and climatic events in italy. il quaternario, it. journ. quatern. sc., 16 (1bis), 16-18. sacco f. (1888) i terreni terziari e quaternari del biellese. 16 pp., 1 carta geol. 1:100.000, guadagnini & candellero, torino. sacco f. (1927) il glacialismo nella valle d’aosta. min. ll. pp., uff. idrog. po, 66 pp. van husen d. (1997) lgm and late-glacial fluctuations in the eastern alps. quaternary international, 3839, 109-118. vanuzzo c. (2001) the glacier retreat in valle d’aosta (western italian alps) from the little ice age to the second half of the 20th century: linear, areal, volumetric and equilibrium line altitude changes. geogr. fis. dinam. quat., 24, 99-113. venturini g. (1995) geology, geochemistry and geochronology of the inner central sesia zone (western alps, italy). mémoires de géologie (lausanne), 25, 1-148. zingg a., handy m. r., hunziker j. c. & schimd s. m. (1990) tectonometamorphic history of the ivrea zone and its relationship to the crustal evolution of the southern alps. tectonophysic, 182, 169192. 123 ms. ricevuto il 3 giugno 2009 testo definitivo ricevuto il 19 aprile 2010 ms. received: june 3, 2009 final text received: april 19, 2010 significato paleoclimatico dei rapporti tra ... impaginato panizza rreeppoorrtt oonn ““ggllaacciiaall”” ffoorrmmss oobbsseerrvveedd oonn aammbbaa aarraaddaamm mmoouunnttaaiinn ((nnoorrtthheerrnn eetthhiiooppiiaa)) mmaarriioo ppaanniizzzzaa dipartimento di scienze della terra – università di modena e reggio emilia (italy) abstract some geomorphologic characteristics observed on amba aradam mountain (tigray region, northern ethiopia) at altitudes of about 2500 to 2780 m a.s.l. and latitude of about 13°30’ n, are described. these features might be ascribed to glacial modeling: cirques, roches moutonnées, glacial shoulders, moraine deposits and moraine arc and palustrine deposit due to moraine barrage. this framework is strongly in contrast with the fact that in ethiopia the presence of glacial cirques and moraines was reported only in mountain areas at altitudes exceeding 4000 m a.s.l. an alternative assumption is that all these features might constitute a very singular case of “geomorphologic convergence”, that is, landforms that have the same shape and appearance but different genesis. riassunto relazione su forme “glaciali” osservate sul monte amba aradam (etiopia settentrionale). vengono segnalate alcune caratteristiche geomorfologiche sul monte amba aradam (regione del tigrai, nord ethiopia) a quote fra circa 2500 e 2780 m .s.l.m. ed a una latitudine di circa 30°30’ n, che potrebbero far pensare a un modellamento glaciale: circhi, rocce montonate, spalle glaciali, depositi e arco morenici, deposito palustre di sbarramento morenico. questo quadro risulta in contrasto col fatto che in ethiopia la presenza di circhi e morene glaciali sono state segnalati soltanto a quote superiori ai 4000 m s.l.m. un'ipotesi alternativa è che ci si trovi di fronte a un caso molto singolare di “convergenza geomorfologica”, cioè di forme del rilievo che hanno la stessa forma, ma che sono il risultato di processi morfogenetici differenti. keywords: quaternary glaciation, ethiopia, glacial morphology, geomorphological convergence parole chiave: glaciazione quaternaria, etiopia, morfologia glaciale, convergenza geomorfologica. il quaternario italian journal of quaternary sciences 1155(2), 2002, 275-278 during the iag international symposium on “climate changes, active tectonics and related geomorphic effects in high mountain belts and plateaux”, held in ethiopia in december 2002, and, in particular, during an excursion to amba aradam mountain, i had the opportunity to observe some very interesting geomorphologic features which are here described. the area surveyed is located sw of makalè, in the tigray region, in northern ethiopia (fig. 1), at an altitude of 2500 to 2780 m a.s.l. and an latitude of about 13°30’ n. it corresponds to an e-w stretching valley, whose head is formed by two small tributary valleys with a ne to sw arrangement. from the geologic standpoint, it is made up of a silicoclastic sandstone sequence of continental facies with quartz conglomerate, shaly and laterite levels, known as “amba aradam formation” (shumburo, 1968; beyth, 1972; dramis, coltorti and pieruccini, 2002), also known as “upper sandstone” (merla and minucci, 1938; mohr, 1962). the age of this formation is ascribable to the cretaceous (see: dramis, coltorti and pieruccini, 2002; nyssen et al., 2002). from the structural viewpoint, the valley’s lower portion seems to be affected by an e-w oriented tectonic line which might have conditioned the original modelling. this tectonic feature does not seem to be linked to the main fault systems described by arkyn et al. (1971) and by beyth, (1972), which are nnw-sse and nne-ssw oriented (dramis, coltorti and pieruccini, 2002). starting from the double head of the valley, the geomorphologic features are as follows (fig. 1). the head of the little northern valley (1a in the geomorphologic sketch of fig. 1) is modeled within a semi-circular cavity with high and steep flanks, partially affected by rock falls which form debris accumulation at the foot of the rocky slopes. also the head of the little ne valley (1b in the geomorphological sketch of fig. 1) has a similar form, although it is not as clearly defined and looks more degraded by erosion and accumulation processes. immediately downstream of the confluence of the two small valleys, a debris deposit is found (fig. 2 and point 2 in the geomorphological sketch of fig. 1), made up of lithologically homogeneous elements (from the amba aradam formation), though with quite a varied grain-size distribution (from blocks to sand and silt). these elements are mixed, non stratified or smoothed, with no apparent signs of friction. on the flanks of the main valley some sandstone outcrops appear to have been modeled in the form of convex and smoothed surfaces, with traces of sub-horizontal grooves which subsequently were partially sectioned by rock shattering processes (fig. 3 and points 3 in the geomorphological sketch of fig. 1). on the floor of the main valley a palustrine deposit is found (fig. 4a and point 4 in the geomorphological 276 m. panizza fig 1 geomorphologic sketch of the amba aradam south-western slope and location of area surveyed. legend: 1 head of small valleys; 2 –debris deposit; 3 – rocks modeled in form of convex, worn smooth surfaces; 4 – palustrine deposits; 5 – debris deposits (5b: diamicton). schizzo geomorfologico del versante a sud-ovest dell’amba aradam e ubicazione dell'area studiata. legenda: 1 – testata di vallecole; 2 – deposito detritico; 3 – roccia modellata in superfici convesse e levigate, con tracce di scanellature; 4 – deposito palustre; 5 – depositi detritici (5b: diamicton). fig. 2 debris deposit at the confluence of the two small valleys. deposito detritico alla confluenza delle due vallecole sketch of fig. 1 ); its origin is evidently due to the damming of the valley by debris accumulation. two detrital bodies developed on the two sides of the valley (fig. 4), one facing south (b) and the other north (c), appear to be responsible for the valley damming and the afore mentioned palustrine deposit. on the whole these two deposits make up an arc-shaped form of varying clarity; the right-hand side deposit (b in fig. 4 and point 5a in the geomorphological sketch of fig. 1) has been partially terraced by anthropogenetic processes. from the grain-size viewpoint, they are both made up of very heterogeneous materials – up to boulders of about ten cubic meters in volume – resulting from the amba aradam formation. 277report on “glacial” forms ... fig. 3 arenaceous rocks modeled in the form of convex, worn smooth surfaces. rocce arenacee modellate in superfici convesse e levigate fig. 4 palustrine deposits (a) and debris accumulations (b and c); the former (b) have been partial ly modeled as terraces by anthropogenetic processes. deposito palustre (a) e accumuli detritici affacciantisi (b e c), dei quali i l primo (b) parzialmente modellato a terrazzo da processi di antropizzione. fig. 5 diamicton from deposit 5b of the geomorphological sketch of fig. 1. diamicton del deposito 5b dello schizzo geomorfologico della fig. 1. 278 outcrop of the detrital body (fig. 5) (c in fig.4 and 5b in the geomorphological sketch of fig. 1): this is a diamicton-type deposit, that is unsorted with sand and coarse particles dispersed through a mud matrix. it is not stratified and some elements show a certain degree of smoothing. the genetic picture of the area points to glacial modeling. there are very evident indications of this; in fact, from top to bottom, the six geomorphologic units previously described seem to be related respectively to: glacial cirques (points 1 in the geomorphological sketch of fig. 1), moraine deposit from glacial confluence (fig. 2 and point 2 in the geomorphological sketch of fig. 1), roches moutonnées (fig. 3 and points 3 in the geomorphological sketch of fig. 1), moraine barrage pond (fig. 4a and point 4 in the geomorphological sketch of fig. 1 ), small moraine arc (b and c in fig. 4 and points 5a and 5b in the geomorphological sketch of fig. 1) and lateral and frontal moraine deposits (b and c in fig. 4 and points 5a and 5b in the geomorphological sketch of fig. 1). this framework seems to be completed by the presence of less inclined portions of slope, similar to the so called “glacial shoulders”. this picture, though, is in contrast with the fact that in ethiopia the presence of glacial cirques and moraines was reported only in mountain areas at much higher elevations (mts. simien, 4620 m a.s.l.; arsi, 4180 m; bale, 4357 m) (nyssen et al., 2002). some authors, such as nilsson (1940) and hovermann (1954), described glacial traces found at lower altitudes, but subsequent researchers (semmel, 1963; potter, 1976; hastenrath, 1977; messerli and rognon, 1980) refused this hypothesis with different arguments (nyssen et al., 2002). certainly the conformation of this e-w stretching narrow and deep valley, sheltered from the wind, could have favored the persistence of snow and ice during a cold pleistocene period. this possibility, though, needs to be further investigated by means of particularly detailed geomorphologic surveys, correlations with other similar traces in other parts of africa placed at the same latitude, and a precise reconstruction of the climatic conditions (temperature, precipitation and wind regimes etc.) existing in the tigray during the pleistocene. as an alternative hypothesis, all these features might constitute a very singular case of “geomorphologic convergence”, that is, landforms that have the same shape and appearance but different genesis. in this case, the area would be a very good educational example to alert the onlooker to simplistic deductions based mainly on exterior appearances, that is, on prevalently descriptive characteristics (panizza, 1996). aacckknnoowwlleeddggeemmeennttss i wish to thank prof. f. dramis (university of roma tre) and dr. j. nyssen (university of makalè) for the useful exchanges of ideas mainly in the field and for the bibliographic informations. rreeffeerreenncceess arkin y., beyth m., dow d.b., levitte m., temesgen h. and hailu t., 1971. geological map of mekelle sheet nd 37-11 tigre province. min. mines, energy and water res., geol. survey ethiopia, addis ababa. beyth m., 1972. paleozoic-mesozoic sedimentary basin of mekelle outlier. northern ethiopia. amer. ass. petrol. geol. bull., 56, 12, 2426-2439. dramis f., coltort i m. and pieruccini p., 2002. geological and geomorphological framework of the excursion area. iag international symposium, addis ababa, december 2002, 1-12. hastenrath, s., 1977. pleistocene mountain glaciation in ethiopia. j. glaciol. [cambridge], 18/79: 309-313. hövermann, j., 1954. über die höhenlage der schneegrenze in äthiopien und ihre schwankungen in historischer zeit. nachr. akad. wiss. göttingen, 6: 111-137. merla g. and minucci e., 1938. missione geologica nel tigrai. vol. 1 “la serie dei terreni”, rendic. reale accad. italia, centro studi africa orient. ital., 3, 362 pp. mohr p.a., 1962. the geology of ethiopia. addis ababa university press, 268 pp. messerli, b. and rognon, p., 1980. the saharan and east african uplands during the quaternary. in: williams m., faure h. (eds.): 87-132. nilsson, e., 1940. ancient changes of climate in british east africa and abyssinia. a study of ancient lakes and glaciers. geogr. ann., 22: 1-79. nyssen j., poesen j., moeyersons j., deckers j., mitiku h. and lang a., 2002. quaternary glaciations in the ethiopian mountains. earth sc. rev., in press. panizza m., 1996. environmental geomorphology. elsevier, amsterdam, 268 pp. potter, e., 1976. pleistocene glaciation in ethiopia; new evidence. journal of glaciology, 17 (75): 148-150. shumburo m.m., 1968. the amba aradam formation (formely the upper sandstone). mobil petroleum ethiopia inc., unpub. semmel, a., 1963. quartärgeologische untersuchungen im hochland von nordwest-aethiopien. z. dtsch. geol. gesellsch., 115 (2-3): 882. ms. ricevuto il 20 gennaio 2003 testo definitivo ricevuto il 4 febbraio 2003 ms. received: genuary 20, 2003 final text received: february 4, 2003 m. panizza imp.dewaeledigreg.pala karst geomorphosites of monte albo (north-east sardinia) jo de waele, felice di gregorio & aldo pala department of geology, via trentino 51, 09127 cagliari e-mail: geoam@unica.it abstract: j. de waele et al., karst geomorphosites of monte albo (north-east sardinia). (it issn 0394-3356, 2005). in this paper the authors present the results of a study performed on the geomorphosites of the monte albo chain (north-east sardinia), an important karst area elongated in a ne-sw direction for a length of 30 km and a width of 5, starting from 50 m a.s.l. and reaching altitudes of more than 1100 m. this relief consists of middle jurassic-lower cretaceous sometimes intensely karstified dolostones and limestones covering with an unconformity a metamorphic palaeozoic basement. although the geomorphosites of monte albo are not so impressive as in other sardinian karst areas it seems noteworthy presenting them in the framework of this spectacular landscape unit that, in its whole, represents an area of great geomorphological interest. among the described geomorphosites many places with didactic surficial karst phenomena (karren fields of monte turuddò, suspended valley of janna nurai, solution flutes and kamenitza of punta catirina, macro-dolines of campu ‘e susu, sas puntas and altudè, ruin-like landforms of nuraghe litu ertiches, canyon of riu siccu), the structural geosite of punta azza ruja, the overthrusts and the conglomerates of cuile su ramasinu, the vertical cliffs of n-monte albo, the geological landscape of punta cupetti and the landslide of punta ervare 'e chervos and two places of hydrogeological interest can be mentioned (sinkhole of bonaettè and karst spring of fruncu ‘e oche). furthermore many subterranean places are enclosed, two vertical karst shafts (tumba ’e nudorra and tumba 'e nurai), several horizontal caves (sa conca ‘e crapa, omines agrestes, locoli, su santuariu, cane gortoé) and a natural tunnel (listincu). all these geomorphosites should be connected in a local network inserted in the monte albo landscape unit, already part of the geomining, historical and environmental park of sardinia (area 6), through the realisation of equipped pathways and the elaboration of explicative maps and panels and a website in which geology, geomorphology, karst, fauna, flora, archaeology and industrial archaeology are described. the explanation of the chain’s genesis, its evolution, its geodiversity and the single elements it contains can help the visitors in understanding the importance of geology and geomorphology on landscape evolution, flora and human activities, that combine in an educational model of great suggestion and efficiency. this proposal of valorisation of these landscape units and their geomorphosites could well be connected to other areas of the region, and the authors hope that the local and regional stakeholders will commit themselves in the valorisation of their territory, giving an important service to the many tourists that come and visit the monte albo. riassunto: j. de waele et al., geomorfositi carsici del monte albo (sardegna nord-orientale). (it issn 0394-3356, 2005). in questo lavoro gli autori presentano i risultati di una ricerca effettuata sui geomorfositi della catena del monte albo (sardegna nordorientale), un’importante area carsica allungata in direzione ne-sw per una lunghezza di 30 km ed una larghezza di 5, con quote che variano dai 50 m s.l.m. della piana fino ad oltre 1100 sulle cime più alte. la catena è costituita da dolomie e calcari di età giurassico medio-cretaceo inferiore, più o meno carsificati, che poggiano in discordanza sul basamento paleozoico metamorfico. anche se i singoli geomorfositi del monte albo non raggiungono l’importanza di quelli riscontrati in altre aree carsiche sarde, tuttavia essi caratterizzano questa spettacolare unità di paesaggio e ne fanno un’area di grande interesse geomorfologico. tra i geomorfositi scelti riportiamo molte morfologie carsiche di elevato interesse didattico e turistico-culturale (campi careggiati di monte turuddò, la valle sospesa di janna nurai, le scannellature e le vaschette di corrosione di punta catirina, le macrodoline di campu ‘e susu, di sas puntas e di altudè, le città di roccia di nuraghe litu ertiches, la gola di riu siccu), i geositi strutturali di punta azza ruja, di cuile su ramasinu e del versante nord della catena, il paesaggio geologico di punta cupetti, la frana di ribaltamento di punta ervare ‘e chervos e due luoghi di interesse idrogeologico (inghiottitoio di bonaettè e sorgente carsica di fruncu ‘e oche). inoltre, molte sono le grotte incluse nell’elenco, tra cui due voragini (tumba ‘e nurai e tumba ‘e nudorra), molte grotte suborizzontali (sa conca ‘e crapa, omines agrestes, locoli, su santuariu, cane gortoé) ed un traforo naturale (listincu). tutti questi geomorfositi potrebbero essere collegati in una rete locale all’interno dell’unità di paesaggio del monte albo e facente parte del parco geominerario, storico ed ambientale della sardegna (area 6), mediante la realizzazione di sentieri attrezzati, l’elaborazione di carte tematiche e pannelli informativi e la creazione di un sito web con l’illustrazione degli aspetti più significativi del paesaggio naturale ed umano. l’illustrazione del paesaggio e della sua evoluzione, della sua geodiversità e dei caratteri dei singoli geomorfositi che esso contiene può aiutare il visitatore a comprendere l’importanza della geologia e della geomorfologia per l’evoluzione del paesaggio e delle molteplici attività antropiche che vi si svolgono, creando un modello educazionale di grande suggestione ed efficienza. questa proposta di valorizzazione dell’unità di paesaggio e dei geomorfositi in essa contenuti potrebbe essere estesa anche ad altre aree della regione. gli autori auspicano che gli amministratori locali e regionali elaborino proposte di valorizzazione di questo territorio caratterizzato da molteplici valenze, dando un importante servizio non solo ai molti turisti che visitano il monte albo ma anche alla popolazione locale. keywords: jurassic limestones, karst, geomorphosites, monte albo, sardinia. parole chiave: calcari giurassici, carsismo, geomorfositi, monte albo, sardegna. il quaternario italian journal of quaternary sciences 18(1), 2005 volume speciale, 145-153 146 j. de waele et al. 1. introduction the study of geomorfosites in karst areas has already brought our research team in many parts of the island; the gulf of orosei (barca et al., 1995), the iglesiente-sulcis area (de waele et al., 1998), the tacchi area (ardau & de waele, 1999; de waele et al., 2004). furthermore the twenty most important karstic geosites of the island have already been described (de waele et al., 1999) and at the moment one of us (de waele) is working on the inventory of natural hypogean geosites in the framework of a national research program performed together with the national geological survey (piccini et al., 2004). in the framework of the national project cofin 2001-2003 “geomorphosites in the italian landscape” our research team has continued these researches, and in this paper the results of a study on monte albo are presented. 2. geology monte albo is a karst area located in north-east sardinia, elongated from ne to sw for a length of 30 km and a width of 5 and reaching altitudes of more than 1100 m a.s.l.. the outcropping rocks can roughly be subdivided in a palaeozoic mainly metamorphic basement and mesozoic sedimentary sequences (fig.1). the characteristics of the palaeozoic rocks are related to the tectonic and metamorphic events of the hercynian orogeny (carboniferous-permian). in the south-eastern part of monte albo the basement is characterised by hercynian granites of permian age, while to the north the outcropping rocks are more or less metamorphic. petrographical and mineralogical studies have allowed to distinguish two important crystallisation episodes (franceschelli et al., 1982; elter & sarria, 1989) and four complexes of different metamorphic degree. the outcropping metamorphic rocks are, roughly from south to north, constituted of metasandstones, phyllites, micaschists, paragneiss, granodioritic orthogneiss and bird’s eye gneiss. after a long-during continental period, estimated from permian to lower jurassic, the sea started occupying the hil ly hercynian peneplain during bajocian-bathonian. the jurassic-lower cretaceous ocean never reached great depths in the monte albo area, and the different carbonate facies evidence several shallow depositional environments, going from lagoons to coral reefs. this sedimentary sequence starts with dolostones containing limestone lenses, oolithic limestones and massive fossil-rich outer-shelf, reef, interreef and backreef limestones. the jurassic transgression starts with clastic sediments of the genna selole formation, represented by quartz conglomerates and sandstones with plant fossils typical of a fluvial or delta environment influenced by tidal movements (amadesi et al., 1961; fazzini et al., 1974; dieni et al., 1983). traces of this transgressional facies can be found at punta casteddu (south monte albo) (dieni & massari, 1971). upwards this facies becomes marly, typical of a littoral depositional environment, and the alternation of marl and dolostone beds preludes the dorgali formation dolostones (amadesi et al., 1961; calvino et al., 1972; dieni & massari, 1985; 1987). these dolostones are sandy in the basal levels becoming pure brownish dolostones in the upper beds and locally contain brachiopods, echinoids, ammonites, belemnites and foraminifers of bathonian-kimmeridgian. at monte albo this formation reaches a thickness of at least 300 meters in the western part (lula), but reduces to only a couple of meters in the eastern extremity (monte gutturgios). upon these dolostones two heterotopic limestone formations are reported: the s’adde limestones and the monte bardia formation (dieni & massari, 1985). the first formation is characterised by brownish microcrystalline limestones sometimes containing chert nodules, not well stratified at the bottom but extremely well bedded in the upper part. the fossil fauna (ammonites, belemnites, brachiopods, echinoids and foraminifers) gives an age of callovian-kimmeridgian. the monte bardia formation instead is composed of typical reef and bioclastic limestones, with frequent fossil corals (sometimes in life position) and their debris. the age of these l imestones, based on corals, gastropods, algae and foraminifers is kimmeridgianberriasian (upper jurassic-lower cretaceous). the uppermost part of this formation is characterised by marly limestones sometimes with mud cracks and fauna of brackish water environments, introducing the deposition of lower cretaceous purbeckian sediments after a short interruption of sedimentation (massari, 1968). these last sediments, composed of marls and marly limestones locally rich in pyrite and organic material, have been deposited in a relatively deep and confined sea and can be found only in two tectonically disturbed areas southwest of siniscola (dieni et al., 1987). their age has been determined on the basis of foraminifers to valanghinian (dieni & massari, 1966). upper cretaceous is not present in the monte albo region, but the discovery of maastrichtian pebbles in the post-middle eocene conglomerate of cuccuru ‘e flores, outcropping in the central-eastern part of monte albo, indicates that these sediments were eroded in late mesozoic-early cretaceous times (busulini et al., 1984). the syn-tectonic continental cuccuru ‘e flores conglomerate was deposited after middle eocene during a tectonic instable and continental period related to the pyrenean and apennine collision (dieni & massari, 1965). the geological sequence of monte albo is completed with pleistocene gravitational deposits, mainly represented west of siniscola (flanks of punta cupetti) and quaternary deposits (alluvium, debris, etc.). the tectonic situation is dominated by two main transcurrent fault systems, ne-sw and e-w, associated with local transpressive and pull apart sectors caused by the continental collision between the apulian plate and the south-european margin during oligocene-lower miocene. the most important fault system in the monte albo area is directed ne-sw (e.g. nuoro fault), running parallel to the national road that connects nuoro with siniscola (carmignani et al., 1994; pasci, 1997). the movement of the transcurrent nuoro fault is left-handed and is believed to be several kilometres for a vertical displacement of approximately 1000 meters and has lead, in the monte albo area, to impor147karst geomorphosites ... fig. 1 – geological sketch map of monte albo with the location of the geomorphosites. carta geologica schematica del monte albo con l’ubicazione dei geomorfositi. tant overthrusting. along these overthrust surfaces many outcrops of the syn-tectonic cuccuru ‘e flores conglomerate can been found. from a morpho-structural point of view these tectonic movements have determined the typical landform of cuesta or hogback to the entire chain, with the more or less gently dipping back towards se (fig.2). 3. karst geomorphology the mesozoic dolostones and limestones of monte albo have been interested by karst processes since their early emersion (upper cretaceous), even though the major karst landforms can be referred to the plio-quaternary. dolostones (dorgali formation, dogger) are characterised by diffuse fractures and joints and a welldefined bedding causing ruin-like landforms (pinnacles) and scarcely developed micro-forms (essentially solution pans or kamenitze). intense fracturing and jointing leads the meteoric water immediately underground with scarce superficial runoff. caves in dolostones usually consist of vertical shafts in which the tectonic imprint is clearly distinguishable. limestones instead (s’adde limestone and monte bardia formation, dogger-malm) are generally microcrystalline and pure carbonates that are ideal for the development of micromorphologies 148 such as solution flutes, rillenkarren, kamenitze etc. (fig. 3). in these rocks interesting solution caves are also formed (e.g. conca ‘e crapa) characterised by phreatic rounded morphologies and well developed calcite concretions. in areas affected by important tectonics (e.g. the southwestern flank of monte albo) no important caves are known and landforms are very much influenced by the tectonic surfaces and subsequent differential erosion. the north-western flank of the mountain is much more exposed to rain than the south-eastern one, also because here are located the highest altitudes (punta catirina and monte turuddò 1127 m a.s.l.). this difference is also clearly visible in the surface landforms. karren fields are well developed especially on the southern slopes of punta sae mussinu, punta ferulargiu and punta su mutucrone. in many areas of high altitude (e.g. the flanks of punta catirina and monte turuddò) the exposed karren fields are much more rounded, being an ancient covered karst. in fact, deforesting of these areas probably goes back to the early 20th century and the covering soil has been washed away since then (fig. 4). a distinct feature on monte albo is the scarcely developed drainage pattern, meaning that seasonal runoff takes place along small river incisions generally directed towards the northwest and the southeast. between punta gutturgius and punta cupetti the valley s’adde cuts though the monte albo carbonates from nw to se and ends with the canyon of riu siccu located on the vertical walls of the southern flanks. this valley has probably been inherited from a period in which the drainage on the north-western palaeozoic basement was directed towards the se and represents thus the initial stage of the formation of a suspended valley. a beautiful example of this latter type is janna nurai, located between monte turuddò and punta catirina at an altitude of approximately 600 meters. this valley flows towards the east ending up in the macrodoline of altudè. this large and complex depression still reflects an ancient drainage pattern with a southwest-northeast direction, finding its natural outlet in the steep badde viola canyon, probably of a much more recent origin. but the most interesting karst landforms of monte albo are the two macrodolines of campu ‘e susu and sas puntas, located on the northeast flank of punta catirina, at an j. de waele et al. fig. 2 – schematic sections showing the structural and geological settings of: a) the two macrodolines campu ‘e susu and sas puntas; b) the two mountains of punta azza ruja and punta urros. for location see fig.1. sezioni schematiche che mostrano le condizioni geologico-strutturali di: a) le due macrodoline di campu ‘e susu e sas puntas; b) i due rilievi dolomitici di punta azza ruja e punta urros. per la localizzazione vedasi fig. 1. altitude of 950 and 900 m a.s.l. respectively (fig. 5). these large depressions are characterised by relatively steep slopes and an almost flat floor, with considerable dimensions (average width of 500 meters and length of almost 1 km). they are probably formed on a palaeovalley, successively transformed in large depressed areas that take the form o macrodolines: their genesis is thus only partially controlled by dissolution of limestone. a small outcrop of “éboulis ordonnées” on the northern slope of sa puntas would represent a pleistocene debris deposit produced by the breakdown of the valley walls. underground karst phenomena are not very well developed on monte albo, especially comparing this karst area with other neighbouring carbonate outcrops such as supramonte or the gulf of orosei. the majority of caves are characterised by vertical development, mostly fracture-controlled shafts with no horizontal branches. the best example of such type of cave is tumba ‘e nurai, a 100 meters deep karst pit with an elliptical plant of 6x12 meters. much more impressive is the spectacular tumba ‘e nudorra cave, a collapsed sinkhole of 45x30 meters width and a depth of 45 meters. this sinkhole resembles somewhat the famous 149 sil cave passage that crosses the punta listincu limestone ridge from side to side. the two active caves are cane gortoé and locoli. the first is located in the village of siniscola and is characterised by approximately 1 km of narrow horizontal cave passages occupied by two different subterranean rivers that join before emerging from the entrance. the second is located at the foot of the monte albo southern flank and gives rise during heavy rainy periods to the locoli river. this cave is characterised by impressive submerged passages for a total length of more than 1050 meters and a water depth of 80 (perna & murgia, 2002). 4. geomorphosites in the framework of the national project cofin “geomorphosites in the ital ian landscape” we have chosen the most interesting karst geomorphosites of monte albo on the basis of an exhaustive bibliographical research, on the analysis of aerial photographs and on detailed field work, inserting them in a geomorphosite database (tab. 1). karst morphology has previously been described by several authors (altara, 1964; mucedda, 1991; pala, 1998). the largest karst landforms on monte albo are the macrodolines: three of these have been inserted in our geomorphosite database: campu ‘e susu, sas puntas and altudè. all three are located in the southern part of the mountain, the first two northeast of punta catirina at an altitude of 950 and 900 m a.s.l. respectively, and altudè two km east of these about 300 meters lower (pala, 1998). all three have the shape of macrodolines, but are most likely genetically related to a post-tectonic tertiary (miopliocene) palaeo-drainage system that had a general w-e direction and drained a morphological height located to the west, now mostly eroded. especially the plain of altudè still reflects the complex pattern of several converging rivers. smaller dolines are scarcely represented on monte albo, except for the spectacular tumba ’e nudorra collapse doline located right on top of the homonymous mountain. tumba karst geomorphosites ... fig. 4 – geomorphological sketch map of the area of the two macrodolines campu ‘e susu and sas puntas. carta geomorfologica schematica dell’area delle due macrodoline campu ‘e susu e sas puntas. fig. 3 – some examples of karst microforms (monte turuddò and punta catirina). alcuni esempi di microforme carsiche (monte turuddò e punta catirina). “cenotes” of mexico, also for the presence of a luxuriant vegetation on its bottom. the horizontal caves of monte albo can be subdivided in relict and active caves (mucedda, 1991). among the first su santuariu, conca ‘e crapa, omines agrestes and galleria listincu can be mentioned. the first three are relic caves with quite well developed chambers and cave passages characterised by important flowstones, while the fourth is a 20 meter long fos150 j. de waele et al. table 1 – the main characteristics of the geomorphosites of monte albo. le principali caratteristiche dei geomorfositi del monte albo. fig. 5 – the macrodoline campu ‘e susu seen from punta catir ina towards the ne. the whole hogback of monte albo is clearly distinguishable. la macrodolina fotografata da punta catirina verso ne. l’intero hogback del monte albo è chiaramente visibile. n° name commune altitude morphotype access importance m a.s.l. 1 campu ‘e susu lula 980 macrodoline b l 2 sas puntas lula 895 macrodoline b l 3 tumba ‘e nudorra lula 910 collapse sinkhole c* r 4 conca ‘e crapa lula 1.055 cave b* l 5 su santuariu lula 240 cave b* l 6 omines agrestes lula 790 cave b* l 7 cane gortoe’ siniscola 45 cave a* l 8 tumba ‘e nurai lula 670 karst pit b* r 9 locoli lula 70 cave a* r 10 listincu lula 635 cave-tunnel c* l 11 bonaette’ lodè 550 swallow hole a l 12 altude’ lula 575 macrodoline a l 13 janna nurai lula 575 suspended valley b l 14 m.te turuddo’ lula 1.080 karren field b l 15 p.ta urros lula 475 geological structure b l 16 p.ta gurturgius lula 830 palaeo-landslide a l 17 p.ta catirina lula 1.090 karst landforms b l 18 s’adde-riu siccu siniscola 500 canyon c l 19 p.ta cupetti siniscola 1029 karst landscape b l 20 litu ertiches lula-irgoli 200 ruin like landscape a l 21 fruncu ‘e oche siniscola 48 karst spring a r 22 albo n flank lula-lodè 500-700 cliffs a l 23 cuile su ramasinu lula 400 tectonic features a l access: a=easy (close to roads), b=difficult (close to equipped pathways), c=very difficult (far from existing pathways and roads), *speleological; importance: l=local, r=regional ‘e nudorra is a unique example of collapse sinkhole and can be classified as one of the most beautiful ones of sardinia (loru & sechi, 1984). of different nature is the famous tumba ‘e nurai pit, located close to the janna nurai pass, constituted of a 100 meter deep karst pit (mucedda, 1983). this is the deepest pit of monte albo, known since a very long time also to local people who narrate fantastic stories about this hole, and it was explored for the first time by speleologist of trieste in 1955 (guidi, 2002). the nearby suspended valley of janna nurai is the most beautiful example of monte albo and one of the most interesting of sardinia. it is clearly visible from the village of lula and constitutes one of the few natural gateways to the mountain from the west. this ancient valley reflects a palaeo-drainage system, connected to the one of the three macrodolines, that flowed towards the east where it continued in the valley of altudè. the only valley that can occasionally become active on monte albo is the s’adde-riu siccu valley, that starts on the metamorphic rocks south of punta cupetti, directs towards the southeast and becomes a beautiful canyon before leaving the carbonate chain with a succession of vertical falls (loru & dore, 1994). from the southeast this valley is clearly visible and is also characterised by beautiful ruin-like landforms (pinnacles). these typical ruin-like landforms are even more developed and easily accessible close to the nuraghe litu ertiches where they form a labyrinth of dolomite rocks and pinnacles. karst micro-forms are not very well developed on monte albo and they are usually confined to monte bardia or s’adde pure limestone facies where slopes are not too steep and vegetation (thus soil) is not too thick. two places are of special interest and have been chosen as geomorphosites: the monte turuddò karren fields and the punta catirina micro-forms. the first is characterised by uncovered karren fields that have been developed under soil cover. soil has probably been washed away since the early 20th century, when intense deforestation changed the natural landscape of monte albo. at punta catirina, especially along the north-eastern slope, rillenkarren, kamenitze and solution channels are relatively well preserved, representing a good didactic example of small scale karst landforms. similar in shape but located on the other extremity of the chain is punta cupetti from where the entire morphology of monte albo can easily be understood. punta cupetti is also characterised by the presence of rich micro-forms sculpted in the s’adde limestones. many caves have been inserted in the database: conca ‘e crapa, su santuariu, omines agrestes and listincu caves are horizontal relics of an ancient underground and complex karst drainage system. while omines agrestes and galleria listincu are small caves (dore et al., 1996), formed by karst solution along fissures, conca ‘e crapa and su santuariu are much more complex and important testimonials of ancient karst processes. conca ‘e crapa is one of the highest caves of sardinia (1050 m a.s.l.), composed of several chambers connected by crawling passages (dédé, 1976; loru & sechi, 1984), and represents a very important habitat for cave dwelling fauna (grafitti, 1996). su santuariu, instead, is located almost 1000 meters lower and is characterised by the presence of massive and important concretions (dore et al., 1996), probably testimonials of a much wetter and warmer climate. at even lower altitudes, at the foot of the mountain, two active caves are classified as geomorphosites; the cane gortoé and the locoli resurgences. the first, located in the centre of the village siniscola at an altitude of 40 m a.s.l. has a development of almost 1000 meters and is very important for its cave dwelling fauna (grafitti, 1996). cane gortoé contains two slowly flowing underground rivers that meet just before exiting the cave and represents the active base level of the karst acquifer of monte albo (mucedda, 1991). locoli instead has a much more impressive appearance and becomes active only after heavy rain periods. this cave, of great hydrogeological importance (maccioni, 1976; murgia, 1999) is located at an altitude of 100 m a.s.l. and has an important underwater development explored during the 80’s by french cave divers (le guen, 1983; pittalis et al., 1983; isler, 1990). the total at present explored development of this cave system reaches more than 1500 meters (perna & murgia, 2002). the underground river that exits the mountain from the locoli cave is believed to come from the bonaettè sinkhole, located at a distance of approximately 4 km wnw at an altitude of 550 m a.s.l. (sanna, 1990). this sinkhole, although not very beautiful and active only after heavy rains, is nevertheless one of the most didactic ones of the monte albo chain, and for its hydrogeological importance this swallow hole deserves its classification as geomorphosite. the current main outflow from the monte albo aquifer is located close to siniscola, near the san giuseppe chapel, and has been known since a long time as the san giuseppe or fruncu ‘e oche spring. this karst spring, with a mean discharge of 80 l/s, is developed on important fault systems at an altitude of 48 m a.s.l. (perna & murgia, 2002). to explain further geological interest of monte albo four non-karstic geomorphosites have been chosen: the geological and tectonic features of punta azza ruja, the punta gutturgius palaeo-landslides, the cuile su ramasinu overthrust with outcrops of the cuccuru ‘e flores conglomerates and the impressive vertical cliffs of the north-western side of the monte albo chain. at punta azza ruja, in the southern part of the carbonate chain, a thick succession of basal dolomite beds dipping southeast clearly shows overthrusting and faulting, while at the foot of punta gutturgius early-quaternary landslides have determined unusual landforms with impressive isolated dolomite blocks. near cuile su ramasinu, instead, overthrusting has enabled the preservation of the eocene cuccuru ‘e flores conglomerate, important testimony of the cretaceous erosion period. 5. conclusions monte albo is an important landscape unit that constitutes a characteristic landmark in the northeastern part of sardinia. landforms are mainly related to karst processes and subordinately to tectonic features. the twenty-three geomorphosites described in this paper represent most of the morphological processes 151karst geomorphosites ... that this mountain went through in the past millions of years. the connection of these geomorphosites in a local network, comprising the realisation of equipped pathways and the elaboration of explicative maps and panels and a website in which geology, geomorphology, karst, fauna, flora, archaeology and industrial archaeology are described, would be an interesting alternative to the conventional tourist offer of this region based on beaches and one-day trips to single tourist sites (nuraghi, show caves etc.). in fact, the explanation of the landscape, its evolution, its geodiversity and the single elements it contains can help the visitors in understanding the importance of geology and geomorphology on landscape evolution, biology and human activities, that combine in an educational model of great suggestion and efficiency. this valorisation fits also well in the framework of the geomining, historical and environmental park of sardinia of which the monte albo landscape unit, comprising the two abandoned mines of guzzurra and sos enattos, is part (area number 6). furthermore, the evaluation of the geological and geomorphological heritage of monte albo enriches the classification of the area on a pure biological basis (cassola & tassi, 1973) and as a site of comunitary interest (directive habitat 92/43, sic itb001107). this proposal of valorisation of these landscapes and geomorphosites could well be connected to other areas of the region, and the authors hope that the local and regional stakeholders will participate in the valorisation of their territory, giving an important service to the many tourists that come and visit the monte albo acknowledgements this study has been carried out in the framework of the national project cofin 2001-2003 “geomorphosites in the italian landscape”, national coordinator prof. sandra piacente of the university of modena, responsibles of the local research unit prof. antonio ulzega and prof. felice di gregorio of the university of cagliari. the comments of the two referees, leonardo piccini and marco firpo were helpful to enhance this paper. references altara e. (1964) cavità del mont'albo (sardegna) sottoterra, 9, pp. 32-36. amadesi e., cantelli c., carloni g.c. & rabbi e. (1961) ricerche geologiche sui terreni sedimentari del foglio 208 dorgali giornale di geologia, 28, pp. 59-87. ardau f., de waele j. (1999) geosites of the tacchi area (central-east sardinia, italy) in: d. barettino, m. vallejo & e. gallego (eds.), towards the balanced management and conservation of the geological heritage in the new millennium, pp. 87-93. barca s., di gregorio f. & mulas g. (1995) natural rock arches of the orosei gulf, sardinia, italy in: e. ozhan (ed.), medcoast 95: proceedings of the second international conference on the mediterranean coastal environment, 24-27 october 1995, tarragona, spain", middle east technical university, ankara, turkey, vol. 1, pp. 217-229. busulini a., dieni i., massari f., pejovic d. & wiedmann j. (1984) nouvelles données sur le crétacé supérieur de la sardaigne orientale cretaceous research, 5, pp. 243-258. calvino f., dieni i., ferasin f. & piccoli g. (1972) note illustrative della carta geologica d’italia, foglio 195-orosei (sardegna) servizio geologico d’italia, roma. carmignani l., barca s., disperati l., fantozzi p., funedda a., oggiano g. & pasci s. (1994) tertiary compression and extension in the sardinian basement boll. geof. teor. appl., 36, pp. 45-62. cassola f. & tassi f. (1973) proposta per un sistema di parchi e riserve naturali in sardegna bollettino società sarda scienze naturali, 13, pp. 51-129. de waele j., di gregorio f., follesa r. & piras g. (2004) geosites and landscape evolution of the "tacchi": an example from central-east sardinia proceedings of the workshop "geomorphological sites research, assessment and improvement", modena 19-22 giugno 2002 il quaternario (this volume) (in print). de waele j., di gregorio f. & piras g. (1998) geosites inventory in the paleozoic karst region of sulcisiglesiente (south-west sardinia, italy) international congress progeo ‘98, 7-13 june 1998, belogradchik, bulgaria geologica balcanica 28(3-4), pp. 173-179. de waele j., di gregorio f. & piras g. (1999) the twenty most important karstic geosites of sardinia in: d. barettino, m. vallejo & e. gallego (eds.), towards the balanced management and conservation of the geological heritage in the new millennium, pp. 155-161. dédé a.m. (1976) grotta sa conca 'e sa crapa (montalbosiniscola) gruttas e nurras, 3, pp. 11-14. dieni i., fischer j.c., massari f., salard-cheboldaeff m. & vozenin-serra c. (1983) la succession de genna selole (balnei) dans le cadre de la paléogéographie mésojurassique de la sardaigne orientale mem. soc. geol. it., 36, pp. 117-148. dieni i. & massari f. (1965) precisazione sull’età di alcuni conglomerati affioranti presso siniscola, orosei e dorgali (sardegna orientale) rend. acc. naz. lincei, cl. sc. fis. mat. nat., 40, pp. 205211. dieni i. & massari f. (1966) i foraminiferi del valanginiano superiore di orosei (sardegna) palaeontol. ital., 61, pp. 75-186. dieni i. & massari f. (1971) scivolamenti gravitativi ed accumuli di frana nel quadro della morfogenesi plio-quaternaria della sardegna centro-orientale mem. soc. geol. it., 10(4), pp. 310-345. dieni i. & massari f. (1985) mesozoic of eastern sardinia in: a. cherchi (ed.), 19th european micropaleontological colloquium-guide book, agip sardinia, 1-10 october 1985, pp. 66-78. dieni i. & massari f. (1987) le mésozoique de la sardaigne orientale groupe français du crétacé, sardinia 24-29 may 1987, pp. 125-134. 152 j. de waele et al. dieni i., massari f. & proto decima f. (1987) excursion dans le crétacé de la sardaigne orientale. m.te albo: carrière de s’ozzastru (siniscola) groupe français du crétacé, sardaigne 24-29 may 1987, pp. 145-149. dore g., loru r., mucedda m. (1996) monte albo 1995-1996: vecchie e nuove grotte bollettino del gruppo speleologico sassarese, 16, pp. 31-40. elter f.m. & sarria e. (1989) assetto strutturale del basamento ercinico e relazioni fra i vari complessi tettonici nel nord est della sardegna atti soc. tosc. sci. nat., mem., ser. a, 96, pp. 81-105. fazzini p., gasperi g. & gelmini r. (1974) ricerche sul verrucano 2. le successioni basali dei "tacchi" tra escalaplano e jerzu (sardegna sud-orientale) bollettino società geologica italiana, 93, pp. 221243. franceschelli m., memmi i. & ricci c.a. (1982) zoneografia metamorfica della sardegna settentrionale in: l. carmignani, t. cocuzza, c. grezzo, p.c. pertusati & c.a. ricci (eds.), guida alla geologia del paleozoico sardo, società geologica italiana. guide geologiche regionali, pp. 137149. grafitti g. (1996) ricerche biospeleologiche nel monte albo (sardegna nord-orientale) -bollettino del gruppo speleologico sassarese, 16, pp. 4148. guidi p. (2002) una spedizione speleo del 1955 (monte albo, sardegna nord-orientale) in: j. de waele (ed.), il carsismo e la ricerca speleologica in sardegna, anthèo, 6, pp. 261-268. isler o. (1990) grotte du locoli spelunca, 39, 12 p.p le guen f. (1983) sub-novità: la riscossa dei francesi. speleologia, 9, pp. 43-44. loru r. & sechi d. (1984) attività a monte albo 19831984 bollettino del gruppo speleologico sassarese, 8, pp. 14-21. loru r. & dore g. (1994) attività 1994 sul massiccio del monte albo bollettino del gruppo speleologico sassarese, 15, pp. 21-25. maccioni g.f. (1976) osservazioni e proposte di studio geo-idrogeologico sulla grotta di locoli (siniscola) gruttas e nurras, 4, pp. 14-16. massari f. (1968) aspetti sedimentologici in una serie calcarea titanico-berriasiana di bassa profondità della sardegna orientale mem. sci. geol., 26, pp. 1-56. mucedda m. (1983) campo 1981 a monte albo bollettino del gruppo speleologico sassarese, 7, pp. 7-9. mucedda m. (1991) fenomeni carsici superficiali e grotte del monte albo monte albo una montagna tra passato e futuro, a cura di camarda (editore), pp. 63-82. murgia f. (1999) il carsismo profondo nei calcari di monte albo (sardegna nord-orientale) in relazione alla formazione di imponenti bacini idrici sotterranei gruttas e nurras, pp. 5-12. pala a. (1998) studio geomorfologico, ambientale e analisi del dissesto del paesaggio carsico dell'area meridionale del monte albo b.sc. thesis in geological sciences, cagliari university, academy year 1997-98, 266 pp. pasci s. (1997) tertiary transcurrent tectonics of north-central sardinia bull. soc. géol. france, 168, pp. 301-312. perna g. & murgia f. (2002) il carsismo profondo messiniano in sardegna: prospettive per la ricerca di acque profonde in: j. de waele (ed.), il carsismo e la ricerca speleologica in sardegna, anthèo, 6, pp. 107-124. piccini l., sauro u., de waele j. & mietto p. (2004) the italian register of natural hypogean geosites: a preliminary report proceedings of the workshop "geomorphological sites assessment and mapping", cagliari 1-5 ottobre 2003 il quaternario (this volume) (in print). pittalis g., penez p. & chouquet j.c. (1983) spedizione alla grotta di "locoli" gruttas e nurras, pp. 12-13. sanna f. (1990) ipotesi dell'esistenza di una grotta a bonaettè (monte albo) gruttas e nurras, pp. 2021. 153karst geomorphosites ... imp.giraudi le oscillazioni di livello del lago di mezzano (valentano vt): variazioni climatiche e interventi antropici carlo giraudi enea c.r. casaccia, c.p. 2400, 00100 roma a.d. riassunto: giraudi c., le oscillazioni di livello del lago di mezzano (valentano vt): variazioni climatiche e interventi antropici. (it issn 0394-3356, 2004). il lago di mezzano é un lago di origine vulcanica presente all’interno della caldera di latera (vt). lo studio dei sedimenti e delle forme di origine lacustre, l’esecuzione di alcune trincee che hanno attraversato i terrazzi più bassi e la datazione di campioni col metodo del radiocarbonio, hanno permesso di riconoscere l’evoluzione recente del bacino idrografico del lago. in particolare é stato possibile individuare varie oscillazioni di livello e cambiamenti di forma e di estensione del lago, indicate da notevoli variazioni nella distribuzione e nella quota dei sedimenti. la presenza di sedimenti databili alla porzione media e finale dell’olocene ha permesso di ottenere informazioni più dettagliate per gli ultimi millenni. l’individuazione di opere di bonifica antiche e recenti e la correlazione cronologica con le oscillazioni di livello di altri laghi dell’italia centrale hanno permesso di stabilire che il livello del lago di mezzano veniva influenzato prevalentemente da fattori climatici, con l’eccezione degli ultimi 2000 anni, quando a tali fattori si sono aggiunti gli effetti dei tentativi di controllo del livello delle acque. abstract: giraudi c., the lago di mezzano (valentano – viterbo) level oscillations:climatic variations and human impact. (it issn 0394-3356, 2004). lago di mezzano is a lake of volcanic origin situated inside the latera caldera. the surface area is about 0.5 km2, and the catchment area is about 1 km2 with few, very small, surface inflows and one outflow. three submerged settlements of pile-dwellings and numerous metal and pottery artifacts, attributable mainly to the bronze age, have been found near the lake shore. study of the sediments and of the morphological features of lacustrine origin, the escavation of a number of trenches across the lowest terraces, and dating of samples by the radiocarbon method, have revealed the recent evolution of the lake’s drainage basin. the geological and geomorphological studies demonstrate changes in the hydrological balance and in the drainage network discharging into the lake; these data further allows the lake level variations evidenced by archaeological settlements to be framed in a clear palaeogeographic context. various late-pleistocene and holocene oscillations in level and changes in the lake’s shape and extent have been indicated by considerable variations in the distribution and depth of the sediments. the presence of sediments that can be dated from the middle and late holocene has enabled more detailed information to be obtained for the last few millennia. the identification of ancient and recent reclamation works, and chronological correlation with the oscillations in level of other lakes in central italy, have established that the level of lago di mezzano was mainly influenced by climatic factors, with the exception of the last 2000 years, when the effects of attempts to control the level of the water can be observed, in addition to said factors. before the artificial drainage, when the level was very high and the lake larger than at present (e.g. during the xv – xvii centuries), the water reached the sill level forming an outflow towards the olpeta river. at periods of high water level the catchment to lake surface ratio was 2.6 calculated from the approximate catchment size of 3.57 km2 and a lake area of about 1.36 km2. when the lake level was very low, the basin became endorheic and the streams of the northern part of the catchment reached the lake in the southernmost place, flowing through the former lake bed. parole chiave: lago di mezzano, livelli lacustri, pleistocene superiore, olocene, paleoclima, impatto antropico. keywords: lago di mezzano, lake levels, late pleistocene, holocene, palaeoclimate, human impact. il quaternario italian journal of quaternary sciences 17(2/1), 2004, 221-230 introduzione il lago di mezzano (lazio, 42°37’n, 11°56’e, 452 m a.s.l.) é un lago vulcanico ubicato all’interno della caldera di latera (viterbo). l’interno della caldera costituisce il bacino di alimentazione del fiume olpeta ed é diviso in vari bacini secondari: alcuni di questi sono collegati da strette incisioni che hanno tagliato le soglie di antichi bacini lacustri (sadori et al., 2004). il lago di mezzano é il più recente e l’unico rimasto tra i laghi presenti all’interno della caldera: occupa il fondo di un piccolo cratere prodotto da una eruzione freatomagmatica avvenuta nel corso delle ultime fasi di attività vulcanica, circa 100.000 anni fa (nappi et al., 1995). il lago ha diametro di 800 m, profondità massima di 31 m, superficie di circa 0.5 km2, ed il suo bacino di alimentazione si estende per circa 1 km2. l’attuale dimensione del lago é però dovuta a lavori di bonifica e regimazione delle acque. prima dell’intervento antropico il bacino di alimentazione ed il lago erano molto più estesi ed era presente un emissario naturale che defluiva liberamente attraverso una soglia dando origine al fiume olpeta. l’emissario attuale (fosso delle volpi) é artificiale, ed anche i maggiori corsi d’acqua che defluivano verso il lago sono stati deviati artificialmente verso il fiume olpeta (fig. 1). le variazioni ambientali avvenute nel bacino del lago di mezzano sono state oggetto di dettagliate ricerche sedimentologiche e geochimiche da parte di vari autori (ramrath et al., 1999a; ramrath et al., 1999b; wilkes et al., 1999; ramrath et al., 2000); le ricerche condotte su carote di sedimenti prelevate sul fondo del lago non sono state corredate da adeguati studi geologici al contorno. secondo gli autori citati i sedimenti hanno registrano le principali variazioni climatiche avvenute negli ultimi 30.000 anni circa e, a partire dall’età 222 c. giraudi del bronzo, c’è stato un evidente impatto antropico. le variazioni geologiche e geomorfologiche, avvenute tra circa 4000 e 3000 anni fa, nel bacino di alimentazione del lago sono state invece prese in considerazione da sadori et al. (2004). tali autori, che si sono occupati in modo specifico dell’impatto sull’ambiente degli insediamenti dell’età del bronzo attraverso l’analisi di dati sedimentologici, pollinici ed archeologici, hanno stabilito che l’influenza antropica sull’ambiente è stata forte per lo più durante periodi di breve durata databili attorno a 3600, 3400 e 2900 anni cal b.p. molti metri sotto il livello del lago di mezzano sono presenti i resti di palafitte, attribuite a due diverse fasi dell’età del bronzo (alessio et al., 1975; petitti & mitchell, 1993; petitti, 2000; sadori et al., 2004): secondo tutte le evidenze i villaggi palafitticoli furono edificati e occupati nel corso di periodi caratterizzati da livelli lacustri molto più bassi dell’attuale. nel presente lavoro vengono evidenziati i risultati degli studi geologici e geomorfologici condotti sui terrazzi e sui sedimenti tardo-pleistocenici e olocenici presenti sia nelle aree che circondano il lago attuale che nella zona occupata dal lago prima della bonifica. attraverso lo studio delle facies e la datazione dei sedimenti è stato possibile riconoscere che il livello e l’estensione del lago di mezzano hanno subìto forti variazioni nel corso del pleistocene superiore e dell’olocene sia a causa di variazioni climatiche che di interventi antropici. fig. 1 carta geologica del bacino del lago di mezzano legenda: 1 sedimenti lacustri del quinto terrazzo; 2 sedimenti lacustri del quarto terrazzo; 3 sedimenti lacustri del terzo terrazzo; 4 materiali vulcanici; 5 accumulo di frana; 6 conoidi alluvionali; 7 orli di terrazzi lacustri; 8 trincee per impianto di irrigazione; 9 sez. 1,2,3; 10 sezione di fig. 3. geological map of the lago di mezzano basin legend: 1 5th terrace lacustrine sediments; 2 4th terrace lacustrine sediments; 3 3th terrace lacustrine sediments; 4 volcanic materials; 5 landslide deposits; 6 alluvial fan; 7 terrace scarplets; 8 trenches for irrigation pipes; 9 section 1,2,3; 10 fig. 3 section. inquadramento geologico e geomorfologico gli studi geologici e geomorfologici condotti attorno al lago di mezzano hanno evidenziato la presenza di terrazzi lacustri, sia deposizionali che erosionali, di conoidi alluvionali e di sedimenti prevalentemente lacustri che formano la piana posta a nord est del lago (fig. 1). tale piana è situata poco al di sopra del livello dell’acqua: prima dei lavori di bonifica era parte dell’alveo lacustre, come ancora indicato da una carta del 1607 riportata in romeo & urbanetti (1996). secondo sadori et al. (2004) prima delle opere di regimazione delle acque, il lago poteva subire notevoli variazioni di livello ed estensione: nel corso di periodi di bilancio idrologico positivo il lago si espandeva sulla zona pianeggiante posta a ne (fig. 2). in alcuni casi il lago raggiunse livelli così alti da superare la soglia e defluire nel fiume olpeta. in questi casi, il rapporto tra superficie del bacino di alimentazione e superficie del lago poteva essere di 2,6:1, considerando 3,57 km2 l’estensione del bacino di alimentazione e 1,36 km2 la superficie del lago. quando il livello del lago non superava la soglia, il bacino diventava endoreico. i corsi d’acqua presenti nella parte settentrionale del bacino di alimentazione raggiungevano il lago scorrendo sulla zona pianeggiante precedentemente occupata dal lago. quando il livello del lago era sensibilmente più basso dell’attuale, ad esempio nel corso dell’età del bronzo (alessio et al., 1975; petitti & mitchell, 1993; sadori et 223le oscillazioni di livello ... al., 2004) il rapporto tra estensione del bacino di alimentazione e superficie del lago poteva arrivare a 9:1, poichè la superficie del lago poteva ridursi a circa 0,4 km2 (fig. 2). l’esame morfologico mostra che il lago è circondato da una serie di lembi di terrazzi lacustri poco estesi posti a quote di circa 460, 456, 453, 451 e 450 m (figg. 1 e 3). la litologia dei depositi sui quali sono impostati i terrazzi è stata rilevata solo in corrispondenza di scavi artificiali, effettuati per la messa in opera di un impianto per l’irrigazione, in quanto l’area è completamente coperta da vegetazione erbacea. il terrazzo più elevato è impostato al tetto di una successione di limi con livelli di sabbia e ghiaia fine ed è presente, oltre che al margine del lago, anche nella zona della soglia dalla quale defluisce il fosso delle volpi; il secondo terrazzo è impostato sui prodotti vulcanici che formano il cratere ed è quindi interpretabile come un terrazzo di abrasione lacustre; è stato riconosciuto solo ai margini del lago attuale; il terzo terrazzo è impostato al tetto di una successione di sedimenti colluviali e lacustri: la base è formata da colluvi limosi con frammenti di ceramica romana non più antichi del ii secolo d.c.; su questi appoggiano sedimenti limosi pedogenizzati di origine lacustre, contenenti sparsi frammenti di mattoni e di ceramica; il terzo terrazzo è il più esteso, poiché occupa gran parte dell’area pianeggiante posta a ne del lago; fig. 2 variazioni dell’estensione del lago di mezzano nel corso di due periodi estremi e confronto con la situazione attuale. nei secoli xvi – xvii il lago raggiunse livelli molto elevati, mentre nel corso dell’età del bronzo il livelli si abbassò notevolmente. l’estensione del lago attaule è condizionato da lavori di regimazione successivi al xvii secolo. the extension of lago di mezzano size during three characteristic periods: present time, 17th centuries and bronze age. the 20th century extent of the lake was produced by reclamations works. 224 il quarto terrazzo è impostato al tetto di sabbie e ghiaie fini di ambiente lacustre litorale; oltre ad essere presente al margine del lago, esso si estende nella zona pianeggiante fin verso la soglia da cui defluisce il fosso delle volpi; il quinto terrazzo è presente al margine del lago e si estende in parte anche nella piana adiacente: è appena più elevato del livello del lago ed appare interpretabile per lo più come una forma di erosione, sui sedimenti che formano il quarto terrazzo, sviluppata dopo la regimazione del lago. la presenza di scavi artificiali ha permesso anche di rilevare, in varie zone, l’esistenza di lembi di ghiaie sabbiose, interpretabili come depositi di spiaggia, posti ad una quota di circa 454 m; tali sedimenti sono databili al periodo immediatamente pre-bonifica (vedasi oltre) ma non danno luogo ad evidenze morfologiche. la scarsità di dati disponibili ha reso necessario lo scavo di varie trincee, lunghe decine di metri, al fine di studiare i sedimenti presenti ai margini del lago, sulla piana adiacente e sulla soglia dalla quale defluisce il fosso delle volpi. l’ubicazione delle trincee è visibile in fig. 1. la sezione 1 corrisponde ad una trincea, lunga circa 60 m, scavata quasi interamente sulla superficie del quarto terrazzo, fino alla profondità di circa 5 m; essa ha mostrato una complessa successione di sedimenti lacustri separati da nette superfici di erosione. alcuni campioni ricchi di sostanze organiche sono stati datati col metodo del radiocarbonio ed è stato possibile stabilire che i sedimenti sono per la maggior parte databil i al le fasi f inali del pleistocene superiore e all’olocene. la serie rilevata è la seguente (dal basso verso l’alto – fig. 4). a: limi grigio verdastri con sabbia e rari ciottoletti, scavati per circa 40 cm; b: limi grigi con sabbia e ghiaia fine, potenti circa 60 cm; c: limo grigio parzialmente eteropico con i sedimenti che formano l’unità b: verso il lago diventa grigio scuro, organico, ben stratificato; la potenza massima osservata è di circa 1 m; un campione prelevato in tali sedimenti e sottoposto a datazione col metodo del radiocarbonio ha fornito un’età di 18.690±210 bp (23.040-21.380 cal bp – beta 106457); d: sabbie grossolane con ghiaia fine, di ambiente litorale, che raggiungono una potenza di circa 1,5 m e appoggiano su una chiara superficie di erosione che incide i sedimenti dell’unità c; e: limi grigi con frustoli vegetali, potenti fino a 1,5 m, con rare, sottili, intercalazioni di sabbie nella porzione intermedia ed al tetto; un campione prelevato verso la base dei sedimenti e datato col metodo del radiocarbonio ha fornito un’età di 13.090±210 bp (16.51014.410 cal bp – beta 106454); f: torba, potente fino a 1,5 m, che appoggia su una superficie di erosione incisa nei sedimenti dell’unità e; un campione prelevato alla base delle torbe e datato con il metodo del radiocarbonio ha fornito un’età di 7800±70 anni bp (8685-8400 cal bp – beta 106455); g: torba, potente al massimo 50 cm, che appoggia su una superficie di erosione incisa nei sedimenti delle unità e ed f; un campione prelevato nella parte alta della torba, datato col metodo del radiocarbonio, ha fornito un’età di 1730±60 anni bp (160-435 a.d. – beta 106456); tra la torba è stata rinvenuta la punta di un palo che, datato col metodo del radiocarbonio ha fornito un’età di 500±40 anni bp (1400-1450 a.d. – beta 128454); h: limo grigio chiaro che raggiunge la potenza di circa 30 cm; i: limo sabbioso grigio chiaro, potente circa 1 m, con intercalato un livello di sabbia e ghiaia fine di ambiente lacustre litorale; il limo giace su una superficie di erosione posteriore all’unità h; un campione prelevato nella porzione intermedia del deposito e sottoposto a datazione col metodo del radiocarbonio ha fornito un’età di 720±50 anni bp (1235-1390 a.d. – beta 106452); fig. 3 quota e litologia dei terrazzi lacustri che circondano il lago di mezzano. legenda: 1sabbia e ghiaia fine; 2limo; 3colluvio con ceramica romana; 4limo con sabbia e ghiaietto; 5substrato vulcanico. lithology and elevation of the terraces surrounding the lago di mezzano. legend: 1sand and gravel; 2silt; 3colluvium with roman pottery; 4sandy gravelly silt; 5volcanic bedrock. c. giraudi 225 fi g. 4 s ez io ni g eo lo gi ch e 1, 2, e 3 . l e se zi on i c or ris p on d on o a tr in ce e ap p os ita m en te s ca va te p er le in d ag in i g eo lo gi ch e le ge nd a: s ez io ni 1 e 2 = 1 s ab b ia ; 2 s ab b ia e g hi ai a fin e; 3 li m o co n sa b b ia e g hi ai a fin e; 4 li m o; 5 t or b a su p er io re ; 6 t or b a in fe rio re ; 7 li m o; 8 s ab b ia e g hi ai a fin e; 9 li m o; 1 0 sa b b ia li m os a; 1 1 lim o co n sa b b ia ; 1 2 lim o ar gi llo so ; 1 3 ar gi lla li m os a; 14 p rin ci p al i s up er fic i d i e ro si on e; 1 5 fr am m en to d i p al o. s ez io ne 3 = 1 t er re no d i r ip or to ; 2 sa b b ia g hi ai os a; 3 s ab b ia ; 4 lim o co n le nt i d i s ab b ia g hi ai os a; 5 s ub st ra to v ul ca ni co ; 6 ca na le a rt ifi ci al e. g eo lo gi ca l s ec tio ns 1 , 2, 3 . th e se ct io ns s ho w t he s tr at ig ra p hy o f th e se d im en ts e xp os ed in t hr ee t re nc he s le ge nd : s ec tio ns 1 a nd 2 = 1 s an d ; 2 gr av el ly s an d ; 3 sa nd y gr av el ly s ilt ; 4 si lt; 5 u p p er p ea t; 6 lo w er p ea t; 7 s ilt ; 8 s an d a nd g ra ve l; 9 si lt; 1 0 si lty s an d ; 1 1 sa nd y si lt; 1 2 si lt an d c la y; 1 3 si lty c la y; 1 4 un co rf or m iti es ; 1 5 b ro ke n w oo d en p ile . s ec tio n 3 = 1 so il ; 2 g ra ve lly s an d ; 3 s an d ; 4 s ilt w ith s an d y gr av el le ns es ; 5 v ol ca ni c b ed ro ck ; 6 m an m ad e ch an ne l. le oscillazioni di livello ... 226 l: sottili alternanze di sabbie ghiaiose, sabbie grossolane, sabbie limose marroni rossastre, e rare intercalazioni di limi con resti vegetali; tali sedimenti sono potenti fino a circa 1,5 m ed appoggiano su una superficie di erosione incisa nei sedimenti dell’unità i; la stratificazione è evidente nell’area prossima alla sponda lacustre ove appare inclinata sia verso il lago che verso l’esterno: probabilmente il deposito formava un cordone litorale; un campione prelevato in un livello di limi con resti vegetali ha fornito un’età radiocarbonio di 980±80 anni b.p. (895-1235 cal a.d. – beta 106453); m: sabbie fini sciolte, che formano la spiaggia attuale, ed appoggiano su una superficie di erosione che incide l’unità l. in relazione ad alcune datazioni radiocarbonio dei sedimenti, occorre sottolineare quanto segue: la data ottenuta dall’unità i appare più recente di quella relativa alla successiva unità l: tuttavia se si prende in considerazione l’incertezza si può verificare che la differenza può essere considerata minima; la presenza di un legno datato 500±40 anni bp (14001450 a.d.) nella parte sommitale delle torbe dell’unità g può sembrare una contraddizione; trattandosi però della punta di un palo, non è azzardato ipotizzare che rappresenti i resti di un palo infisso in età rinascimentale, scomparso dai sedimenti più superficiali a causa dei processi di ossidazione verificatisi dopo l’emersione. la sezione 1 è stata quella che ha fornito maggiori informazioni su stratigrafia e cronologia dei sedimenti affioranti al contorno del lago. la sezione 2 corrisponde per lo più ad una trincea, scavata parallelamente alla sponda lacustre (fig. 1), che ha interessato il quarto ed il quinto terrazzo. i sedimenti affioranti in tale sezione (fig. 4) sono del tutto analoghi ai più recenti descritti nella sezione 1. tuttavia un sondaggio, eseguito con una trivella a mano, ha indicato che nei pressi dell’emissario artificiale del lago è presente un’incisione, profonda almeno 3 metri, riempita da sedimenti argillosi-limosi, nella parte profonda, e poi limosi-argillosi, aventi litologia, colore e consistenza diversa da quelli rinvenuti nelle trincee. l’incisione indica che durante periodi di basso livello lacustre, il lago era alimentato da un corso d’acqua proveniente dalla porzione settentrionale del bacino e che tale corso d’acqua aveva inciso i sedimenti che formavano la sponda lacustre. la sezione 3 corrisponde ad una trincea, lunga complessivamente circa 80 m e profonda fino a 4 m, scavata attraverso la soglia dalla quale defluisce il fosso delle volpi e dalla quale, in caso di livello lacustre particolarmente elevato, defluiva l’emissario naturale del lago (fig. 1 e 4). la trincea ha permesso di rilevare anche la stratigrafia dei sedimenti che formano il terzo terrazzo e di raggiungere il substrato dei sedimenti lacustri, costituito da materiali vulcanici alterati. i sedimenti presenti sono (dal basso verso l’alto): limi mal stratificati grigio-giallastri con frustoli vegetali, passanti verso l’alto a limi grigio-marroni scuri pedogenizzati, con frequenti intercalazioni lenticolari di ghiaie fini in matrice sabbiosa e sabbiosa-limosa: queste corrispondono chiaramente ad alvei di piccoli corsi d’acqua incisi di 10/20 cm nei sedimenti limosi e poi colmati; sia tra i limi che tra le ghiaie sono stati ritrovati frammenti di mattoni e di ceramica; nella parte più profonda della trincea è stata individuata una incisione netta e regolare (fig. 4), profonda almeno 1,2 m e larga fino a 2,5 m, che taglia il substrato vulcanico: nella parte bassa risulta riempita da limi con sabbia grossolana e ciottoli, quindi da limi; l’aspetto dell’incisione è completamente diverso da quello degli alvei presenti tra i limi successivi e sembra essere dovuta a scavi effettuati nell’antichità; si assume quindi che vi siano stati interventi di regimazione precedenti a quelli moderni; limi sabbiosi e poi sabbie, parzialmente eteropici con i limi descritti in precedenza, che raggiungono la potenza di circa 1 m; alla base di tali sedimenti sono stati rinvenuti resti di carbone che sono stati sottoposti a datazione col metodo del radiocarbonio ed hanno indicato una età di 330±50 anni b.p. (14501665 cal a.d. – beta 106458); sabbie ghiaiose potenti fino a 1,5 m, coperte dal suolo attuale. la stratigrafia dei sedimenti messi in luce dalle trincee comprende quindi depositi lacustri databili agli ultimi 20.000 anni, ma ha evidenziato l’esistenza di importanti lacune di sedimentazione. interpretazione dei dati i dati esposti nel capitolo precedente si prestano ad interpretazioni utili per ricostruire le variazioni ambientali e le oscillazioni di livello del lago. se prendiamo in considerazione i terrazzi lacustri (4 di origine naturale e uno successivo all’intervento di regimazione) possiamo dire che, mentre i più bassi sono molto recenti, databili al ii secolo d.c. (il terzo terrazzo), al xiii-xiv secolo (il quarto terrazzo) e ad un momento successivo al xv-xvii secolo (il quinto), non vi sono dati relativi ai due terrazzi più alti. per tentare di datarli si è fatto ricorso alla correlazione con altre località. al lago di vico, un lago vulcanico posto a distanza di poche decine di chilometri, sempre in provincia di viterbo, è stata rilevata la presenza di un numero di terrazzi pari a quelli del lago di mezzano e, come nel caso in studio, l’ultimo di questi si è prodotto in seguito ad opere di regimazione antropiche (giraudi, 2000). al contrario di quel che accade per il lago di mezzano, i tre terrazzi più recenti che circondano il lago di vico sono stati inquadrati cronologicamente nell’olocene, ma i sedimenti che li formano non sono stati datati con metodi radiometrici. risultano invece datati i due terrazzi più antichi la cui età è compresa tra 28.700 anni b.p. (non calibrato) e 17.000 anni cal b.p. e tra circa 17.000 anni cal b.p. e 13.000 anni cal b.p. poichè anche ai margini del lago del fucino (giraudi, 1998), in situazioni geologiche e topografiche totalmente diverse, è stata rilevata la presenza di terrazzi di età analoga, è stato assunto (giraudi, 2000) che i terrazzi suddetti siano stati prodotti da alti livelli lacustri provocati da variazioni climatiche. in questa ottica possiamo ipotizzare che i terrazzi più elevati presenti al lago di mezzano siano databili agli stessi periodi. l’inquadramento cronologico dei terrazzi non appare smentita dai dati stratigrafici derivanti dalle trincee scavate. nella sezione 1, sedimenti lacustri fini delle unità c ed e contengono le date, rispettivamente, di 23.040-21.380 anni cal b.p. e c. giraudi 16.510-14.410 anni cal b.p. e sono ubicati all’esterno della sponda lacustre attuale; non si tratta certamente di deposti di ambiente litorale: la loro presenza sembra confermare l’esistenza di un lago più esteso dell’attuale contemporaneo alle fasi di alto livello lacustre dei laghi di vico e del fucino. si assume quindi che l’unità c sia contemporanea al modellamento del primo terrazzo e che l’unità e sia correlabile cronologicamente al secondo terrazzo. per quel che riguarda l’interpretazione generale che può essere tratta dai sedimenti messi in evidenza dalle trincee scavate (fig. 4) è possibile osservare quanto segue: le facies dei sedimenti indicano frequenti variazioni ambientali con transizioni da ambiente litorale e di spiaggia ad ambienti di lago più profondo, e quindi dimostrano il verificarsi di variazioni di livello lacustre; i sedimenti presenti nelle trincee prossime alla sponda del lago attuale sono interessati da varie lacune stratigrafiche; queste sono state prodotte dalle erosioni avvenute nel corso delle fasi di emersione provocate dalle diminuzioni di livello del lago; l’incisione profonda almeno tre metri, rappresentata nella sezione 2, deve essere contemporanea ad uno o più abbassamenti di livello, probabilmente quelli verificatisi nel corso dell’età del bronzo; i successivi aumenti di livello ne produssero poi il colmamento; oltre a sedimenti dovuti alle variazioni lacustri, vi sono sedimenti colluviali contenenti resti di ceramica romana in posizione stratigrafica e altimetrica corrispondente a quella del canale artificiale, precedente al xvxvii secolo (sezione 3 – fig.4), rilevato sotto la superficie del terzo terrazzo; per tale motivo si ritiene che siano stati attuati lavori di regimazione del lago in epoca romana; il ritrovamento di depositi di spiaggia a quote elevate databili al periodo posteriore al xv-xvii secolo conferma l’estensione del lago rappresentata nella cartografia storica: i lavori di bonifica successivi hanno modificato notevolmente la dimensione del lago e prodotto una sostanziale stabilizzazione della linea di costa. per il suo inquadramento cronologico, la superficie di erosione che separa i due livelli di torba (unità f e g fig. 4), potrebbe essere contemporanea al forte abbassamento di livello del lago verificatosi nel corso dell’età del bronzo ed essere stata parzialmente rimodellata in età romana, a causa di una diminuzione di livello prodotta dalla regimazione del lago. per quel che riguarda la datazione e la valutazione delle quote raggiunte dal livello del lago, deducibili dalle facies, dall’età e dalla quota dei sedimenti (fig. 4), è possibile notare quanto segue. in corrispondenza della sedimentazione dell’unità c, il lago modellò il primo terrazzo, l’acqua raggiunse un livello di circa 460 m e poi si abbassò notevolmente; infatti la superficie di erosione successiva raggiunge una quota di 447 m; i sedimenti di spiaggia dell’unità d si trovano fino a circa 449 m di quota, e questa può essere considerata, approssimativamente, indicativa del livello raggiunto dalle acque del lago; vi è quindi stata una risalita rispetto al minimo raggiunto al momento del modellamento della superficie di erosione compresa tra le unità c e d; in corrispondenza della sedimentazione dell’unità e il lago modellò il secondo terrazzo e l’acqua raggiunse la quota di circa 458 m, confermando la tendenza alla risalita di livello indicata già dall’unità d; successivamente il livello del lago si abbassò almeno fino alla quota di 448 m, quando si sviluppò la superficie di erosione posta a tetto dell’unità e; le torbe dell’unità f indicano un nuovo aumento di livello fino ad una quota simile o superiore all’attuale; successivamente dovette verificarsi una diminuzione di livello del lago fino a quote inferiori a 448 m, come dimostra la superficie di erosione presente al tetto dell’unità f; tale superficie di erosione deve avere avuto una evoluzione molto complessa poiché i sedimenti che la sigillano (unità g) hanno età notevolmente più recente dei depositi dell’unità f; come detto in precedenza, questa erosione è in parte contemporanea ai bassi livelli lacustri dell’età del bronzo: gli insediamenti palafitticoli, databili a due diversi periodi (le date medie calibrate dei pali datati da alessio et al. (1975) si aggirano attorno a 3400 e 2900 b.p.) si trovano fino a quote di 440-441 m; poiché gli insediamenti erano situati presso l’antica sponda lacustre si assume che le suddette quote siano, anche se non nel dettaglio, rappresentative del livello lacustre del tempo; la stessa superficie di erosione deve essersi evoluta anche al momento della regimazione romana del lago; le torbe dell’unità g indicano un ritorno dell’acqua lacustre a quote superiori alle attuali in un periodo successivo alla regimazione del lago di età romana; i sedimenti dell’unità i indicano una continuazione della tendenza alla risalita di livello del lago fino ad una quota superiore all’attuale, anche se tra i sedimenti limosi vi è una intercalazione di depositi litoranei che indicano una riduzione del livello del lago; la superficie di erosione posta al tetto di tale unità indica poi un nuovo abbassamento di livello lacustre fino a quote inferiori a 449 m; in corrispondenza dell’unità l il livello del lago torna a crescere fino ad una quota prossima o superiore a 451 m; l’aumento di livello del lago continua poi fino alla deposizione dei sedimenti di spiaggia posti a circa 454 m, che rappresentano gli ultimi depositi precedenti alle opere di regimazione moderna. i dati relativi alle età ed alle quote raggiunte dall’acqua del lago nei vari periodi sono rappresentati in fig. 5. discussione anche se la successione sedimentaria presenta molte lacune, l’interpretazione dei dati ha permesso di riconoscere variazioni di livello e di estensione del lago. tali variazioni devono, evidentemente, essere legate a cambiamenti avvenuti nel bacino di alimentazione del lago di mezzano, provocate da fattori naturali o da cause antropiche. la bonifica posteriore al xvii secolo ha ridotto notevolmente l’estensione ed il livello del lago rendendo disponibile per l’agricoltura circa 1 km2 di terreno pianeggiate, precedentemente occupata dalle acque. la 227le oscillazioni di livello ... stessa zona emerse anche in epoca romana quando i lavori di regimazione provocarono la diminuzione di livello dell’acqua. nel corso dell’età del bronzo i villaggi palafitticoli presenti sulla sponda del lago produssero certamente un impatto sull’ambiente, come dimostrato da sadori et al. (2004). la durata dell’impatto antropico è stata però limitata al periodo di presenza degli insediamenti palafitticoli. tuttavia gli insediamenti si svilupparono quando il livello del lago era già sceso a quote molto basse e vennero poi sommersi dalla risalita delle acque. per questo motivo si ritiene che l’attività antropica dell’età del bronzo non sia stata la causa principale delle oscillazioni di livello del lago. le altre oscillazioni registrate dai sedimenti sarebbero invece da attribuire a variazioni del bilancio idrologico indotte dal clima. in fig. 5 sono messe a confronto le variazioni di livello del lago di mezzano e quelle dei laghi fucino e vico: si può osservare che, nonostante le lacune di sedimentazione, le oscillazioni del lago di mezzano tra circa 22.000 e 14000 anni fa possono essere correlate, in generale, con quelle del lago di vico riportate da giraudi (2000). inoltre, le variazioni lacustri avvenute tra circa 10.000 e 4000 anni fa, sono paragonabili, in generale, a quelle del lago fucino riportate in giraudi 228 fig. 5 oscillazioni di livello del lago di mezzano e correlazioni con le variazioni di livello del lago di vico e del fucino. legenda: 1 datazioni radiometriche; 2 livello del lago inferiore alla quota segnalata; 3 livello del lago superiore alla quota segnalata; 4 periodi di bassi livelli lacustri; 5 oscillazioni di livello dovute ad intervento antropico. lake level variations of the lago di mezzano and comparison with the water level oscillations in the vico and fucino lakes. legend: 1 radiocarbon ages; 2 lake level lower that the elevation evidenced; 3 lake level higher than the elevation evidenced; 4 periods of low lake level; 5 lake level oscillations produced by human impact. c. giraudi (1998), basate su un numero molto maggiore di dati. per gli ultimi 4000 anni, avendo a disposizioni più dati, è possibile verificare che le variazioni di livello nei laghi di mezzano e fucino sono pressoché coeve (fig. 5) ed escludere, per le variazioni di livello dell’età del bronzo una causa antropica. infatti, le due forti oscillazioni negative registrate a mezzano attorno circa 3400 e 2900 anni b.p. sono presenti anche al fucino, un lago molto più esteso ed il cui bilancio non poteva essere facilmente influenzato dalle popolazioni preistoriche e protostoriche. in entrambe i laghi sono state eseguite opere di regimazione o bonifica nel corso del periodo romano e in epoca moderna. i forti aumenti di livello raggiunti nelle fasi finali del pleistocene superiore ai laghi di mezzano, fucino e vico, corrispondono a fluttuazioni climatiche avvenute nel corso dell’ultimo massimo glaciale e indicate anche dalle fasi glaciali dell’appennino (giraudi, 1998; giraudi, 2004). secondo ramrath et al. (1999a) l’inizio del tardiglaciale e mezzano è datato circa 14.500 anni cal b.p.: proprio attorno a tale data ha inizio anche la diminuzione di livello lacustre. la fortissima diminuzione di livello databile a poco meno di 4000 anni b.p. coincide con il crollo della concentrazione del polline presente nelle carote studiate da sadori et al. (2004). l’aumento di livello di età compresa tra circa 2900 anni b.p. e l’intervento di regimazione romano sembra correlabile cronologicamente ad un evento registrato nell’appennino: la fase di avanzata del ghiacciaio del calderone che ha provocato la copertura di un suolo datato attorno a 2800 anni cal b.p. (giraudi, 2002; 2004). inoltre gli aumenti di livelli del periodo precedente all’anno 1000 e del xv-xvii secolo possono essere correlati cronologicamente a fasi di avanzata del ghiacciaio del calderone datati al periodo compreso tra vii e x secolo ed alle fasi iniziali della piccola età glaciale (xv-xvi secolo). conclusione lo studio dei sedimenti lacustri e dei terrazzi presenti ai margini del lago di mezzano ha permesso di verificare che nelle fasi finali del pleistocene superiore e nell’olocene si sono verificate numerose variazioni di livello dell’acqua. la maggior parte di tali oscillazioni sembra dovuta a variazioni climatiche che hanno modificato il bilancio idrologico del bacino di alimentazione del lago. vi è una buona correlazione tra le oscillazioni dei laghi di mezzano, vico e fucino ed alcuni eventi climatici registrati in italia centrale, comprese le aree sommitali dell’appennino. durante l’olocene gli aumenti di livello delle acque sono contemporanei a fasi di avanzata neoglaciali del ghiacciaio del calderone, quindi a periodi di clima più fresco e umido. sono altresì evidenti le conseguenze di due interventi antropici: il primo databile all’età romana, il secondo effettuato in epoca successiva al xvii secolo. in entrambe i casi il livello del lago e le dimensioni del suo bacino di alimentazione sono stati fortemente ridotti per recuperare all’agricoltura una vasta zona di terreno pianeggiante in precedenza coperto dall’acqua. ringraziamenti le ricerche sul lago di mezzano sono state condotte in collaborazione con la soprintendenza archeologica per l’etruria meridionale, in particolare con la dott. p. petitti. si ringrazia il dott. e. cerilli per la collaborazione prestata durante parte delle ricerche di campagna. le ricerche sono state condotte con il supporto finanziario del ministero per l’ambiente nell’ambito di un accordo di programma enea – ministero per l’ambiente, progetto 2.4 – variazioni climatiche. riferimenti bibliografici alessio m., bella f., improta s., belluomini g., calderoni g., cortesi c., manelli g.l., vigilante, a. (1975) university of rome carbon 14 dates xiii. radiocarbon 17, 313-327. giraudi c. (2000) le oscillazioni di livello del lago di vico (lazio) nell'ambito delle variazioni climaticoambientali dell'italia centrale. il quaternario, 13 (1/2),21-30. giraudi c. (1998) late pleistocene and holocene lake level variations in fucino lake (abruzzo central italy) inferred from geological, archaeological and historical data. esf workshop "palaeohydrology as reflected in lake-level changes as climatic evidence for holocene times". palaoklimaforschung, 25, 1-17. gustav fisher verlag ed. giraudi c. (2002) le oscillazioni del ghiacciaio del calderone (gran sasso d’italia, abruzzo italia centrale) e le variazioni climatiche degli ultimi 3000 anni. il quaternario, 15 (2), 145-150. giraudi c. (2004) the apennine glaciations in italy. in: ehlers,j., gibbard, p.l. (eds.), quaternary glaciations-extent and chronology, part. i: europe. 215-224. amsterdam. elsevier. nappi g., renzulli a., santi p., gillot p.y. (1995) geological evolution and geochronology of the vulsini volcanic district (central italy). bollettino società geologica italiana 114, 599-613. petitti p. (2000) la caldera di latera: appunti su materiali di nuova scoperta e contatti a lunga distanza. in: negroni catacchio, n. (ed.), preistoria e protostoria in etruria. atti del iv incontro di studi. milano, 141-149. petitti p., mitchell e. (1993) dati preliminari sulla topografia dell’abitato sommerso del lago di mezzano. in: vulcano a mezzano, 17-31. comune di valentano-museo civico. ramrath a., nowaczyk n.r., negendank j.f.w. (1999a) sedimentological evidence for environmental changes since 34,000 years bp from lago di mezzano, central italy. journal of paleolimnology 21, 423-435. ramrath a., zolitschka b., wulf s., negendank j.f.w. (1999b) late pleistocene climatic variations as recorded in two italian maar lakes (lago di mezzano, lago grande di monticchio). quaternary science reviews 18 (7), 977-992. ramrath a., sadori l., negendank j.f.w. (2000) sediments from lago di mezzano, central italy: a 229le oscillazioni di livello ... record of late glacial/holocene climatic variations and anthropogenic impact. the holocene 10 (1), 87-95. romeo l., urbanetti p.e. (1996) la rappresentazione del territorio di vulci e montalto di castro. mostra cartografica, bibliografica, documentaria . catalogo. ed. cooperativa archeologica. 82 pp. arti grafiche giorgi & gambi, firenze. sadori l., giraudi c., petitti p., ramrath a. (2004) human impact at lago di mezzano (central italy) during the bronze age: a multidisciplinary approach. quaternary international,113/1,5-17. wilkes h., ramrath a., negendank j.f.w. (1999) compositional variations of sedimentary organic matter as indicators of environmental changes since 34.000 years bp at lago di mezzano, central italy. journal of paleolimnology 22, 349–365. 230 ms. ricevuto l’11 maggio 2004 testo definitivo ricevuto il 22 giugno 2004 ms. received: may 11, 2004 final text received: june 22, 2004. c. giraudi amq62 giraudi.pub �� � �available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 30 (2), 2017, 93-103 the morphology of the base of the alluvial sediments of the vercelli plain (piedmont, nw italy): an integration of the knowledge on the quaternary geological evolution carlo giraudi enea c.r. saluggia, saluggia (vc), italy corresponding author: c. giraudi <carlo.giraudi@enea.it> abstract: the southern vercelli plain lies on the top of the westernmost apennine thrust front (monferrato thrust front). according to previous studies, it is interested by quaternary tectonics and, despite the absence of historical earthquakes, could be affected by ml 6 earthquakes. however the lack of middle pleistocene river sediments and terraces in the southern part of the plain prevents any knowledge of the geological evolution for a period that lasted about 600-700 ka and limits the data useful to establish the seismo-tectonic characteristics of the monferrato thrust front and to establish the seismic hazard. using the data derived from studies carried out in the 70s and 80s of the 20th century in order to localize a nuclear power plant, including field surveys, the drilling of dozens of boreholes, geophysical surveys, and hydrogeological studies of superficial waters and aquifers, and also data on the base of the unconfined aquifer, it has been possible to evidence the morphological features of the surface that lies at the base of the alluvial sediments. the data indicate that in the southern vercelli plain there are small valleys and ridges covered by alluvial sediments, originated by erosion connected with the alpine rivers and local streams, that do not show any evidence. the pattern of the buried ridges and valleys appears to be influenced by tectonic movements along faults that, only in part, correspond to the monferrato thrust front and transverse deformation zones active until the middle pleistocene. only for a small area, the buried drainage network flowed towards a karst system developed in messinian gypsum. keywords: quaternary, geological evolution, alluvial sediments, buried morphology, salt-karst in gypsum, vercelli plain, piedmont, italy. 1. introduction the present work aims at a more complete definition of the geological evolution of the vercelli plain. the succession and distribution of fluvial terraces in this area indicate the presence of quaternary tectonics (gsqp, 1976; enel, 1984; giraudi, 2014) and the relationship between the hydrographic network and the buried tectonic structures of the apennines thrust front (monferrato thrust front) are similar to those known in the easternmost apennines front (bonadeo et al., 2010; burrato et al., 2012; michetti et al. 2012; livio et al., 2015). however, unlike the other sections of the front, the vercelli plain is characterized by extremely low seismicity, represented by very few earthquakes with local magnitude < 3 and also with their hypocentre located at depths exceeding 50 km (rovida et al., 2011; rsni, 2014a, b). in the southeastern part of the plain, geodetic studies (arca and beretta, 1985) have also documented an uplift rate of more than 4 mm/year-1 between 1897 and 1957 ad, a period without earthquakes. according to michetti et al. (2012), the vercelli plain could be a seismic gap area, where the magnitude of the earthquakes could reach values close to ml6. published studies have provided information on the geological evolution of the area and on the shaping of the fluvial terraces since marine isotopic stadium (mis) 22, according to giraudi (2014). while near the edge of the hills the terraces were formed only during the late pleistocene and holocene, in the northernmost area there are six older terraces dated between the late early pleistocene and the late middle pleistocene. it follows that in the plain near the hills, the age of the terraces allows the evolution to be assessed only since the late pleistocene (fig. 1a). in fact, in the late early pleistocene and the early middle pleistocene, alpine rivers that shaped the oldest terraces abandoned the area nearest to the hills and migrated north, and only in the late pleistocene returned to occupy the southern area (giraudi, 2014). the lack of glaciofluvial and fluvial sediments (from now on “alluvial sediments”) and terraces thus prevents any evaluation of the evolution of the southern plain for a period of about 600-700 ka. the purpose of this study is to fill this knowledge gap and recognize at least some of the phases of the geological and morphological evolution that occurred before the late pleistocene and to outline the evolution of the area since the end of the lower pleistocene. � �� � � 94 giraudi c. 2. methods to achieve the goal of outlining the geological evolution of the area since the end of the lower pleistocene some stratigraphic and morphological data were taken into account. the strong variations in thickness of the sediments of alluvial origin have been evaluated over the vercelli plain lying near the northern edge of the monferrato. the sediment thickness variations are derived from enel (1984) and from the stratigraphic data reported in the data-base of the piedmont region, and in particular from the map of the base of the unconfined aquifer (regione piemonte, 2004). the shape of the surface lying at the base of the alluvial sediments, showing gentle ridges and depressions, was compared with the morphology of the valleys in the adjacent monferrato hills, reported in the carta tecnica of the piedmont region at 1:10, 000 scale, in order to check any similarities, and with the direction of known tectonic structures, definitively active during the early and middle pleistocene (giraudi, 2014; 2016), in order to detect any tectonic constraints. in particular, when the remnants of the depressions have similar directions to those of the main tectonic structures on which, or near which, they are located, or when significant changes occur in the buried drainage in correspondence with tectonic structures, it has been assumed that tectonics have influenced, directly or indirectly, the evolution of the drainage network that shaped fig. 1 morphological and tectonic sketch of the vercelli plain between the rivers dora baltea, po, and sesia. 1a fluvial and fluvioglacial terraces forming the vercelli plain. s1-s3: terraces forming the trino isolated hill (rit); s4-s8 terraces shaped by alpine rivers when their beds were far from the present ones; t9-t11: terraces forming a belt near the present-day alpine river beds; l1-l2: terraces shaped by local streams. � �� � � 95 the morphology of the base of the alluvial sediments of the vercelli plain (piedmont, nw italy): …. the buried surface. the position of the thrust front and of the structures connected with it, assumed in the present paper, have been discussed in giraudi (2014; 2016). in those papers it was observed that the various models, inferred from the geophysical data, if considered in detail, overlap only partially the structures indicated by the field and borehole data: therefore in the present paper are reported only faults and deformation zones that have been evidenced by field researches and borehole data and that show a clear post-pliocene activity. the chronological framework of the erosion phases that shaped the surface on which the alluvial sediments lie is based on the age of the sediments on which the fig. 2 isobaths of the base of the unconfined aquifer and morphological and geological features buried by the alluvial sediments. 2amap of the isobaths of the unconfined aquifer (modified from regione piemonte, 2004) and morphological features buried by alluvial sediments. a1 thickness of the alluvial sediments dated between ca 870 ka bp and the present (from giraudi, 2014). 2b interpretation of the morphological features at the base of the unconfined aquifer, comparison between the direction of the valleys covered by alluvial deposits and of some valleys and streams in the nearby hills, correlations between morphological features and tectonic elements, and age of the sediments that form the buried monferrato. �� � � surface lies and of the sediments that seal it, and on a comparison with the shaping of the oldest terraces, for which we have dating elements. the age of the fluviolacustrine, fluvioglacial and fluvial sediments, discussed in giraudi (2014; 2016), is based on palaeomagnetic data, on the presence of a tephra layer (reported in enel, 1977; 1984), on the correlation with the nearby ivrea morainic amphitheatre, and on archaeological artefacts dating from the lower palaeolthic to the roman age. 3. geological outline of the southern vercelli plain the vercelli plain, mainly formed by sediments of the dora baltea, po and sesia rivers, extends southwards as far as the monferrato hills (fig. 1). in the 70s and 80s of the 20th century, the plain was the subject of thorough geological surveys in order to site a nuclear power plant (enel, 1977; 1984). the researches produced a wealth of data which, integrated with the most recent data, are subject to different interpretations. geological studies carried out between 1975 and 1984 (enel, 1977; 1984) were intended to improve knowledge of the tectonic evolution of the monferrato thrust front, that is, the westernmost of the apennine chain thrust fronts. the studies included geological and geomorphological field surveys, the drilling of dozens of boreholes up to 200 m deep, geophysical surveys using electric (fig. 2a) and seismic methods, and finally, the hydrogeology and the geochemical characteristics of surficial waters and aquifers. in more recent years, the review of the data has suggested some new interpretations that have increased our understanding of the pliocene-pleistocene geological evolution of the area enabling it also to confirm previous interpretations and to assume the presence of tectonic structures transverse to the front (fig. 1b), which sometimes affect also the neighboring hills (bigi et al. 1990; costa, 2003; giraudi, 2014; 2015; 2016). the vercelli plain is made up of a series of terraced sedimentary units, whose origin is mainly glaciofluvial and fluvial, that can be dated between ca. 0.87 ma ago and the present time (fig. 1a). according to the data reported in enel (1976; 1984) and giraudi (2014; 2016), in the southern plain the sediments are less than 20 m thick (fig. 2a) and cover a complex erosional surface that shapes the top of strongly deformed tertiary marine sediments, similar to those forming the monferrato hills (fig. 2b). the marine sedimentary units buried in the vercelli plain will be called, from now on, the buried monferrato. the buried monferrato also includes piacenzian marine sediments and gelasian littoral ones (enel, 1984; violanti and sassone, 2008; giraudi, 2016) that contour the oldest marine sediments and do not outcrop on the adjacent hills (fig. 2b). the sequence of tertiary sediments sampled in boreholes drilled in the buried monferrato deserves special attention because it helps to recognize the displacement produced by some tectonic structures. according to enel (1984), in the area north and south of the rit, the pre-pliocene sediments are represented by the late oligocene-early miocene marne di antognola formation and by late cretaceous and eocene ligurian units (complesso indifferenziato and casale monferrato formation) outcropping also in the neighbouring hills. in the area near fontanetto po, the sediments are messinian (post-evaporitic, evaporitic and pre-evaporitic) consisting also of layers of crystalline gypsum, both compact and laminated, and of conglomerates with pebbles of crystalline gypsum, which do not outcrop in the adjacent hills. the messinian sediments then, although not studied in detail, show a succession similar to that of some stratigraphic sections studied by clari et al. (2008) and dela pierre et al. (2016) in the piedmont tertiary basin, south of the monferrato. the marine sediments that form the buried monferrato (fig. 1b, 2b) and the early pleistocene fluviolacustrine sediments, lying north of the thrust front but close to the tectonic structures, can dip strongly towards the north and be affected by both low-angle and subvertical fault plains, sometimes with striae (giraudi, 2016). the activity of the monferrato thrust front lasted until the lower or middle pleistocene (gsqp, 1976; enel, 1977; 1984; cassano et al., 1986; costa, 2003; galadini et al., 2012; giraudi, 2014). instead, according to some authors the thrust front would still be active (bonadeo et al., 2010; burrato et al., 2012; michetti et al. 2012; livio et al., 2015). in giraudi (2014) it is observed that two areas near crescentino and trino, having their axis oriented approximately n-s, seems affected by a weak late pleistocene and holocene uplift, supporting the hypothesis, advanced by previous authors, that tectonics are still active. the uplift, however, occurred also north of the thrust front, in places subsiding during the main phases of activity of the structure (fig. 1b). the deformation of the sediments is connected to the activity of faults, i.e. the lucedio, cavourrina, and crescentino fault (lf, caf, and crf in fig. 1b), the fontanetto po, trino and salera line deformation zones (fdz, tdz and sldz of fig. 1b), and the crescentino and morano flexures (giraudi, 2014; 2016). according to costa (2003) a first fault, the position of which corresponds to the crescentino fault of the present paper, and a second fault, corresponding to the salera line deformation zone, acted as transpressive structures that cut across the buried fronts. the lucedio and cavourrina faults overlap only in part short stretches of two different thrust fronts evidenced by geophysical researches (enel, 1977; 1984; cassano et al., 1986; bigi et al. 1990), according to giraudi (2014; 2016). the displacement of tertiary and quaternary sediments produced by the faults indicate that, near the surface, they acted as normal faults that moved downward the sediments lying north. in the fontanetto po and trino deformation zones, the vertical component of the displacement produced the subsidence of the areas west of fontanetto po and east of trino. also the flexures lie only on some stretches of thrust fronts. thus, not knowing the real connection between the superficial and deeper tectonic structures, in the present paper, the evolution of the erosion surfaces 96 giraudi c. �� � � that shaped the buried monferrato will be compared only with the activity of faults, deformation zones and flexures, active during the quaternary, that have been characterized using borehole data and field observations, without any reference to the activity of the monferrato thrust front that could be more complex. some analysis of the deformation phases, of the age and sedimentary facies of the early and middle pleistocene lacustrine, fluvio-lacustrine and alluvial units lying north of the lucedio fault and in the cerrina valley syncline, in the monferrato hills (fig. 2b), have been discussed in giraudi (2016). the data enabled it to be hypothesized that the hilly area north of the cerrina valley and the buried monferrato lying between the hills and the lucedio and cavourrina faults, were involved in the same phases of migration toward north of the monferrato thrust front. the review of the stratigraphy of the boreholes reported by enel (1984) has shown that in some cases, in correspondence with the fontanetto po deformation zone (fdz fig. 2b), the tertiary sediments are affected by subvertical fault planes and that, in general, to the west of the deformation zone, the sediments (messinian, pliocene and early pleistocene littoral) are more recent than those located to the east (ligurian units, dated between the upper cretaceous and the lower-middle eocene, and marne di antognola formation, dated between the upper oligocene and the lower miocene). in addition, to the west of the fontanetto po deformation zone, both the contact between the pliocene and pre-pliocene sediments and the northern limit reached by the ligurian units are considerably further south than in the eastern area. these data confirm the presence of that deformation zone, suggested by giraudi (2016) on the basis of the correlation between the cavourrina fault segment oriented nne-ssw and a series of fault lines oriented approximately n-s and nne-ssw identified in the bed of the po, and also probably a left slip component. along the trino deformation zone (tdz in fig. 2b), postulated by giraudi (2016) on the basis of the correlation between the eastern branch of the cavourrina fault segment oriented nnw-sse and a series of fault lines oriented approximately n-s and nnw-sse identified in the bed of the river po, it can be observed that, to the west, the sediments (ligurian units, marne di antognola formation) are older than those located to the east (marine pliocene and early pleistocene). in addition, to the west of the trino defomation zone, the northern limit reached by pre-pliocene tertiary sediments, corresponding to the cavourrina fault, lies considerably further north than in the eastern area, suggesting a possible right slip component. to the north of the lucedio fault (fig. 3a), the oldest continental sediments lying in the area between the crescentino fault and the salera line deformation zone are strongly deformed, while w and e of these structures, the sediments are gently tilted northward (enel, 1984; giraudi, 2016). during the phases of activity of the lucedio fault, the buried monferrato was uplifted while in the subsiding northern basin a syncline evolved having its axis nearly parallel to the fault (pieri and groppi, 1981; enel, 1984; cassano et al., 1986). based on the difference between the elevations of the base, the different thicknesses and the age of the alluvial sediments north and south of the lucedio fault, said fault may have been active up to about 0.4 ma ago and the total deformation of the bottom of these sediments has been estimated as between 80 and 120 m (giraudi, 2014; 2016). the succession of quaternary sediments lying on the buried monferrato is represented by alluvial deposits which chronologically refer from about 0.87 ma ago to the present (giraudi, 2014). these sediments form ten different terraces (s1, s2, s3, s4, s7, s8, t9, l2, t10, t11 fig. 1a). the oldest terraces (s1-s3) form the rit, a ridge which rises 40-50 m above the surrounding plain (fig. 3b). the lower terraces incline mainly from west to east, only those ne of the rit inclining mainly from wnw to ese. north of the lucedio fault, early pleistocene fluviolacustrine deposits lie below alluvial ones that started to sediment during the mis 22 (giraudi, 2014; 2016). in this area, where the terraces s1, s2 and s3 are lacking, rivers formed three terraces (s5, s6, l1), lacking south fig. 3 the trino isolated hill (rit). 3a: geological section through the hill and the surrounding terraces. 3b: morphological features and buried and present-day divides (modified from giraudi, 2016). 97 � the morphology of the base of the alluvial sediments of the vercelli plain (piedmont, nw italy): …. �� � � of the fault, and sloping mainly from nw to se. 4. the buried morphology and the base of the unconfined aquifer since the enel (1984) studies, it is known that in the buried monferrato the base of the unconfined aquifer corresponds indisputably to the top of the marine sediments, mostly marl and clay, while in the area just north of the lucedio fault it generally corresponds to the contact between alluvial and fluvio-lacustrine sediments. the comparison of the thickness of river sediments reported in giraudi (2014), based mostly on the enel (1984) data, and the shape of the base of the unconfined aquifer reported on the piedmont region map (regione piemonte, 2004) confirms the previous data. the two maps (fig. 2a), albeit at a different scale and resulting from the processing of data of different origin, show a substantial accordance for the buried monferrato and the area located immediately to the north. also the data reported in irace et al. (2009), on a less detailed map, show a similar trend. in addition, the set of geophysical surveys and calibration boreholes carried out in the central area of the buried monferrato (enel, 1977; 1984) provided a reconstruction of the top of the marine sediments which confirms, with more detail (fig. 4a), the trend shown by the map of the regione piemonte (2004). the map of the base of the unconfined aquifer is thus taken as the basic document for discussion and interpretation of the main morphological features buried by the alluvial sediments in the southern portion of the vercelli plain, while the more detailed map of the rit and neighbouring areas (fig. 4) is used to discuss some specific features. it should first be noted that in fig. 2 the continuity of the isobaths of the base of the aquifer is interrupted by the presence of the po riverbed, which is eroding the monferrato hills and buried monferrato tertiary marine sediments, and acts as the southern boundary of the unconfined aquifer. in any case, in fig. 2a the stretches of the po riverbed with different characteristics have been highlighted: in the less incised ones the tertiary sediments occasionally outcrop, in the more eroded ones the same marine sediments constitute most of the riverbed; and finally the deeply incised riverbed, where also the river banks consist of tertiary sediments. the map of the depth of the base of the unconfined aquifer (fig. 2a) shows some elements of direct interest such as ridges and depressions covered by alluvial sediments. the most obvious buried ridge is oriented approximately west-east, and lies beneath the alluvial sediments of the rit: towards the east, it becomes less noticeable and takes an approximately nw-se direction, while to the west it takes a north-south direction. the southern edge of this ridge is cut by the po riverbed which, precisely in this area, is more incised. ridges are less evident nw of fontanetto po and near crescentino, but one of them, which lies ne of crescentino, divides into two a buried depression described below. among the depressions covered by alluvial sediments, the most obvious one runs from the area west of crescentino to costanzana, east of the rit, while a second one, the southernmost one, runs from morano po to the area north of casale monferrato. the first of these depressions is complex, with the presence, west of crescentino and north of the rit, of deeper closed basins separated from the rest of the depression by means of some buried ridges. other minor depressions lie near crescentino, fontanetto po, palazzolo and north of the rit. north of fontanetto po there is a small closed depression with its bottom lying some metres below the top of the buried monferrato in the surrounding area. the morphology of the top of the buried monferrato, corresponding to the base of the unconfined aquifer, in the fontanetto po area has been highlighted in detail by the use of a greater number of boreholes and geophysical surveys. fig. 4a, modified from enel (1984), shows that the morphology of the top of the marine sediment is very complex, being affected by gentle ridges and depressions. the more evident ridge is buried under the rit. two other major ridges are lying north of palazzolo, running from nw to se. there are also elongated depressions in various directions and, especially, in the area north of fontanetto po, there is a complex closed depression, corresponding to that observed in fig. 2a. a special case concerns the rit. the base of alluvial sediments which form the terraces s1 and s2, dating from the final stages of the early pleistocene (giraudi, 2014), fills a depression running n-s and then ne-sw, while the sediments that form the s3 terrace fill a depression (only partially preserved due to erosion) that seems oriented from nnw to sse. said direction is not very different, therefore, from that of the southernmost depressions. 5. the buried morphological features: interpretation and discussion the interpretation of the buried depressions and ridges (fig. 2a), is based on the comparison with the direction of the valleys carved by the streams on the hills, and on the relationship between the identified morphological features and the lithology of the tertiary sediments and the tectonic structures affecting the buried monferrato and the northernmost areas (fig. 2b). the comparison allows some immediate interpretations. the two stretches of the depression that extends from west of crescentino to the costanzana area (fig. 2b) nearly overlap a syncline, evidenced by geophysical data and wells for oil research, that was formed in the subsiding basin north of the lucedio fault during the pliocene and early pleistocene (montrasio et al., 1969; pieri and groppi, 1981; enel, 1984; cassano et al., 1986). the westernmost depression is almost parallel to the crescentino flexure, while the remaining stretch is almost parallel to the lucedio fault. the depression west of crescentino is a closed one, therefore it cannot have been produced only by river erosion but also by tectonic deformation. also the depression extending towards 98 giraudi c. �� � � � 99 fig. 4 detailed map of the isobaths of the base of the unconfined aquifer, and interpretation of the morphological features buried by alluvial sediments near the trino isolated hill (rit). 4amap of the isobaths of the base of the unconfined aquifer and buried morphological features. 4binterpretation of the buried morphological features, main tectonic structures active after 870 ka bp, upper cretaceous to early pleistocene marine sediments forming the buried monferrato. the morphology of the base of the alluvial sediments of the vercelli plain (piedmont, nw italy): …. �� � � costanzana, that overlaps a long stretch of the pliocene and early pleistocene syncline, does not correspond only to a river incision, subsequently filled by sediments, because it includes two smaller closed depressions that can be explained only by assuming a tectonic deformation. moreover, the western and eastern boundaries of the same depression lie in correspondence with the extension towards the northwest of the crescentino fault and with the salera line deformation zone. the subsidence of the area lying north of the lucedio fault suggests that between the early and middle pleistocene sedimentation prevailed over the erosion (giraudi, 2016). the second wide depression, which lies north and east of morano po, is almost parallel to the morano flexure, and nearly overlaps a post-pliocene syncline, evidenced by geophysical data and wells for oil research, that was formed in a basin north of the flexure (see geological sections in montrasio et al., 1969). the depression, filled by sediments dated since the mis 22 (giraudi, 2014), ends abruptly to the west and, if it had been produced only by the erosion of a river, it would have to continued toward west or nw. the depression north of the morano flexure starts just east of the salera line deformation zone while, as reported before, the depression that lies north of the rit ends in correspondence with the northern extension of the same deformation zone. therefore, the salera line deformation zone could also have played a role in influencing the evolution of the buried morphologies at its western and eastern edges. other linear depressions, smaller in size and having various orientations, run from marginal areas towards the axis of the main depressions: it follows that the smaller depressions were probably palaeovalleys weakly carved by local streams. in the area north of palazzolo and nw of trino the depressions run from nnw to sse and then bend e. the trend of these depressions appears similar to that of the valleys in the adjacent hills (fig. 2b). it is therefore likely that the shaping of the buried depressions observed in that area and of the valley in the monferrato was conditioned by the same tectonic and morphological forcing factors. the depressions lying between the fontanetto po deformation zone and the crescentino fault, show a sennw trend, while those observed west of the crescentino fault run towards the north, like the valleys in the adjacent hills. figure 2b shows some interpretations of the buried ridges. the main ridge present in the rit area and towards the hills is almost parallel to the cavourrina fault and the fontanetto po deformation zone. however, the ridge has an irregular shape, because it was affected by the erosion produced by the heads of catchment basins of small streams tributary to the main rivers. the secondary ridge located east and north of crescentino is aligned with the extension towards the northwest of the crescentino fault, at the boundary between the sediments gently deformed by the crescentino flexure and the sediments strongly deformed by the lucedio fault (giraudi, 2014; 2016). the more detailed data shown in fig. 4 confirm the presence of a main buried divide trending west-east in the rit area, which is connected to the stretch of the divide running south. that ridge lies at the northern and western margins of the area uplifted by tectonics along the cavourrina fault and the fontanetto po deformation zone, and is almost parallel to these structures. south of the rit, there are smaller buried divides trending nw to se, and separate buried valleys elongated from nw to se, then about west-east and, in some cases, wsw-ene. the valleys are the same already highlighted in the less detailed map of fig. 2, and confirm a trend similar to that of the valleys in the adjacent monferrato hills. in fig. 4 the differences in elevation between the various sections of the main divide can be observed: the divide reaches 180 m a.s.l. under terrace s1 of the rit and 148-146 m a.s.l. under terrace s3, while below the upper pleistocene and holocene sediments, forming the s7, s8, t9, t10 and t11 terraces, its elevation is between 146 and 132 m a.s.l. the buried divide, then, reaches the lower elevation near the margin of the hills, below the alluvial sediments of the most recent terraces, having been subject to fluvial erosion until the late holocene. the present summit elevation of the top of the divide may have been influenced not only by its original height and by the river erosion but also by sub-aerial erosion that occurred before the alluvial fill, and by tectonic uplift. in the absence of any alluvial cover, the divide was subject to sub-aerial erosion, but when covered, it ceased to evolve and its height can only have been influenced by tectonics. for a long time, while the main rivers flowed north of the rit, south of the isolated hill the stretch of the divide running n-s was not covered by river sediments, and thus underwent sub-aerial erosion. only in the initial phase of the late pleistocene, when diversion of the alpine rivers to the south of the rit occurred (giraudi, 2014), this stretch of divide began to be affected by more intense fluvial erosion and was then covered by alluvial deposits. the tertiary sediments that form the buried divide southwest of the rit are clearly cut into by a scarp elongated about w-e located exactly in correspondence with the escarpment between terraces s7 and s8 (fig. 1a; fig. 4b). it is clear that in this area the top of the divide was eroded during the late pleistocene, but that the erosion did not erase entirely the morphology shaped earlier. the small valleys carved in the buried monferrato, including those that drain into the fontanetto po endorheic depression, may have orientations similar to those of tectonic structures even when they are not exactly overlapping these. in any case, the valleys have orientations generally different from those of the alpine rivers (flowing mainly w-e) that shaped the late pleistocene and holocene terraces. the comparison between the shape and direction of the divide in the buried monferrato below the alluvial sediments and the current divide between the basins of 100 giraudi c. �� � � the po and of the stura stream in the adjacent monferrato hills (fig. 2b, box a) shows that they are very similar in shape and that their west-east stretches are parallel to the cavourrina fault, while those oriented approximately north-south are almost parallel to the fontanetto po deformation zones (fig. 2b, box a). this correspondence does not seems to be accidental because the buried monferrato and the monferrato hills consist of the same marine sediments and suffered a common displacement towards the north during the last phase of the thrust front migration (giraudi, 2016). also from fig. 2b (box b), it can be observed that a series of valleys in the monferrato, and the buried divide east of the rit, change direction becoming nw-se, as does the northern edge of the hills. as stated above, the directions of the hill streams and of the current and buried divides have a pattern very similar to that of the cavourrina fault, but fig. 2a (box b) also indicates that the main change of direction of the buried morphological features occurs just south of those affecting the lucedio fault and the axis of the depression parallel to the fault. the buried morphological and tectonic features assume a nnw-sse and nw-se direction on the northern and southern prolongations of the trino deformation zone, which corresponds to the eastern branch of the cavourrina fault (giraudi, 2016). in box c of fig. 2b, it is possible to note that, at the southern continuation of the salera line deformation zone, the northern edge of the hills, the valleys carved in the hills and in the buried monferrato, after a short west-east stretch, change direction, assuming a sw-ne or wsw-ene trend. overall, therefore, the trend of the buried valleys and divides on the buried monferrato is similar to that of the monferrato hills, as can be expected from areas that have undergone a common geological and tectonic evolution. the changes in the direction of the buried morphological features, of the drainage network and of the divides between the catchment basins, lie almost in correspondence with the most important tectonic structures surrounding the area between the lucedio fault and the cerrina valley, that was subject to the common geological evolution until 400 kyr ago, according to giraudi (2016). this general correspondence suggests that the drainage evolution was directly or indirectly conditioned by tectonics affecting the area until, at least, the last periods of activity of the lucedio fault. the most singular buried morphology occurs just north of fontanetto po: it is a closed basin which includes some small valleys that converge towards the deepest part of the depression. the direction of the longer valleys is mostly parallel to the fontanetto po deformation zone (nne-ssw), while two shorter valleys run nw-se. the parallelism between the longer valleys and the direction of the deformation zone suggests that their incision could have been influenced by tectonics. the closed depression, and the small drainage network that it contains, may have originally been a continuation to the nw of the valleys lying east of the buried divide, but later, the continuity of the valleys could have been broken by the activity of the fontanetto po deformation zone that produced the subsidence of the western area. however, the presence of messinian sediments (fig. 4b) with compact gypsum near the deepest part of the closed depression suggests a hypothesis that may be alternative or complementary to that presented above. the closed basin may have formed due to the development of salt-karst in the gypsum. the presence of a karst swallow-hole could have attracted the streams that carved small valleys. the presence of salt-karst in the gypsum and of small closed depressions that drain into the karst systems are known in the southern slope of the monferrato hills (fioraso et al., 2004) and confirms that the hypothesis of the presence of salt karst in the gypsum in the buried monferrato is quite likely. apart from the closed depression possibly produced by karst, the wider and longer buried ridges and depressions are superimposed or lie close to and are parallel to tectonic structures: it is thus assumed that the shaping of the buried morphology was directly or indirectly influenced by the tectonics. 6. age and evolution of the buried drainage network the maximum possible age for the beginning of the shaping of the drainage network of the buried monferrato corresponds to the age of its emersion from the sea. the core of the monferrato hills, being surrounded by pliocene sediments of littoral facies, would have emerged already during the pliocene (sacco, 1889; carraro et al., 1980; dela pierre et al., 2003). the buried monferrato, made up of tertiary marine sediments, is surrounded by littoral sediments dated at the beginning of the gelasian (giraudi, 2016). it follows that during the gelesian the buried monferrato could already have emerged from the sea. other chronological data stem from the rit: the portion of the main divide buried below the oldest continental sediments (mis 22, started 0.87 ma ago) was shaped during the early pleistocene. in its southern part, the main divide lies buried beneath the sediments that form the late pleistocene and holocene terraces, is a very gently sloping ridge and, in theory, could have been formed in the whole period between the gelasian emersion and the late pleistocene-holocene. the differences in elevation between the various sections of the main divide, discussed before, allow it to be hypothesized that the whole divide was formed during the early pleistocene and was partially eroded during the erosional and depositional processes that led to the formation of the pleistocene and holocene terraces. 9. conclusions the morphology of the basal surface of the alluvial sediments that host the unconfined aquifer in the southern vercelli plain allows new hypotheses to be advanced as to the geological evolution of the area north and south of the lucedio and cavourrina faults. the main depressions are located just north and are parallel to the lucedio fault and crescentino and 101 the morphology of the base of the alluvial sediments of the vercelli plain (piedmont, nw italy): …. �� � � morano flexures, they overlap the area subsiding until the first half of the middle pleistocene, and are broken or end in correspondence with tectonic elements transverse to said structures. when the alpine rivers flowed north of the lucedio fault, the small streams, fed by the uplifting area south of the fault, flowed towards the rivers, carving small valleys. south of the lucedio fault, on the buried monferrato, there are ridges covered by alluvial sediments, and small valleys originated by erosion connected to the alpine rivers and local streams. the main buried ridge lies at the northern and western margins of the area uplifted by tectonics along the cavourrina fault and the fontanetto po deformation zone, and is almost parallel to these structures. this ridge can be interpreted as a divide between catchment basins of short streams, that drained to the se, and the po basin. in the area between the lucedio fault and the hills lie other small buried ridges, corresponding to minor divides between the basins of local streams. the buried valleys and ridges were carved mainly during the period between the gelasian and the late early pleistocene, but in part of the area south of the trino isolated hill they were eroded until the late pleistocene and the holocene. the direction of the small buried valleys was similar to that of the present-day valleys in the monferrato hills, to the course of the po and to the belt of its most recent terraces. in addition, changes in the direction of the valleys occur in correspondence with tectonic elements transverse to the lucedio and cavourrina faults and the crescentino and morano flexures. the direct or indirect connection between the shaping of the drainage network and tectonic activity is, therefore, likely. the trend of the main buried features, thus, has been influenced by tectonic movements along the lucedio and cavourrina faults and the transverse deformation zones. the direction of the small buried valleys north of fontanetto po, conversely, was mainly conditioned by the presence of a karst system developed in messinian gypsum. after the late pleistocene diversion of the po south of the trino isolated hill the former divides have been partially eroded, and the alluvial sediments filled the small valleys and shaped low terraces. references arca s., beretta g.p. (1985) prima sintesi geodeticageologica sui movimenti verticali del suolo nell’italia settentrionale (1897-1957). boll. geodes. sc. affini, 44 (2), 125-156. bigi g., cosentino d., parotto m., sartori r. & scandone p. (1990) structural model of italy, consiglio nazionale delle ricerche (cnr), progetto finalizzato geodinamica, quaderni de "la ricerca scientifica", 114 (3), 1:500.000 scale, florence, selca. bonadeo p., brunamonte f., michetti a.m., livio f., fioraso g. (2010) paesaggio sismico dell’arco del monferrato: analisi preliminare. gngts, atti del 16° congresso nazionale, 93-97. bonsignore g., bortolami g.c., elter g., montrasio a., petrucci f., ragni u., sacchi r., sturani c., zanella e. (1969) note illustrative della carta geologica d’italia, fogli 56 e 57 (turin e vercelli). servizio geologico d’italia, rome. burrato p., f. ciucci, g. valensise (2012) un approccio geomorfologico per la prima individuazione di strutture potenzialmente sismogenetiche nella pianura padana. gngts, atti del 18° congresso nazionale, pp. 18. carraro f., forno m.g., ricci b. (1980) ricostruzione preliminare dell’evoluzione plio-pleistocenica dell’area corrispondente ai rilievi delle langhe, del monferrato e della collina di turin. contributi alla realizzazione della carta neotettonica d’italia. cnr progetto finalizzato geodinamicasottoprogetto “neotettonica”. publication no. 356, 315330. carraro f., collo g., forno m.g., giardino m., maraga f., perotto a., tropeano d. (1995) l’evoluzione del reticolato idrografico del piemonte centrale in relazione alla mobilità quaternaria in: polino r. & sacchi r. (eds.), atti del convegno: rapporti alpiappennino. acc. naz. sci. sc. doc, 14, 445-461. cassano e., anelli l., fichera r., cappelli v. (1986) pianura padana: interpretazione integrata di dati geofisici e geologici. 73° congresso della società geologica italiana. 1-27. costa m. (2003) the buried apenninic arcs of the po plain and northern adriatic sea (italy): a new model. boll. soc. geol. it., 122, 3-23. clari p., bernardi e., cavagna s., dela pierre f., irace a., lozar f., martinetto e., trenkwalder s., violanti d. (2008) alba e tramonto della crisi messiniana. guida all’escursione, alba, 10-11 october 2008. dela pierre f., michailov v., polino r. (1995) the tectono-sedimentary evolution of the tertiary basins in the western po plain: kinematics inferred from subsidence curves. in: polino r. & sacchi r. (eds.), atti del convegno: rapporti alpiappennino. acc. naz:sci.sc.doc, 14, 129-146. dela pierre f., piana f., boano p., fioraso g., forno m.g., polino r. clari p. (2003a) carta geologica d'italia alla scala 1:50.000, foglio 157 "trino", apat, agenzia per la protezione dell'ambiente e per i servizi tecnici dipartimento difesa del suolo, rome. dela pierre f., piana f., fioraso g., boano p., bicchi e., forno m.g., violanti d., balestro g., clari p., d’atri a., de luca d., morelli m., ruffini r. (2003b) note illustrative della carta geologica d’italia alla scala 1:50, 000, foglio 157 “trino”, apat, agenzia per la protezione dell’ambiente e per i servizi tecnicidipartimento difesa del suolo, rome, pp. 147. dela pierre f., natalicchio m., lozar f., bonetto s., carnevale g., cavagna s., colombero s., sabino m., violanti d. (2016) the northernmost record of the messinian salinity crisis (piedmont basin, italy). geological field trips, 8 (2.1), pp. 58. doi 10.3301/gft.2016.03). 102 giraudi c. �� � � enel (1977) studio geologico della zona di trino vercellese. enel, direzione delle costruzioni, rome, unpublished. enel (1984) rapporto per la localizzazione di una centrale elettronucleare nella regione piemonte. area po 1. enel direzione delle costruzioni, rome. xix volumes, unpublished. fioraso g., bicchi e., irace a., boano p. (2005) manifestazioni carsiche nelle evaporiti messiniane del monferrato e della collina di turin (italia nordoccidentale): analisi dei meccanismi genetici nel quadro dell’evoluzione pliocenico-quaternaria del bacino terziario piemontese. il quaternario-italian journal of quaternary sciences, 17 (2/2), 453476. galadini f., falcucci e., galli p., giaccio b., gori s., messina p., moro m., saroli m., scardia g., sposato a. (2012) time intervals to assess active and capable faults for engineering practices in italy. engineering geology, 139-140, 50-65. gianotti f., forno m.g., ivy-ochs s., kubik p.w. (2008) new chronological and stratigraphical data on the ivrea amphitheatre (piedmont, nw italy). quaternary international, 190, 123-135. giraudi c. (1981) presenza di depositi mediopleistocenici intensamente deformati in val cerrina (monferrato settentrionale). geogr. fis. din. quat., 4, 69-74. giraudi c. (1998) l'evoluzione del po nei pressi di trino (prov. di vercelli piemonte) tra l'eta' del bronzo ed il xvii secolo. il quaternario, 11(2), 227 -232. giraudi c. (2014) quaternary studies as a tool to validate seismic hazard potential of tectonic structures: the case of the monferrato thrust front (vercelli plain, nw italy). alpine and mediterranean quaternary, 27(1), 5-28. giraudi c. (2015) quaternary evolution of the plain between casale monferrato and valenza: implications for the tectonics of the monferrato thrust front (piedmont, nw italy). alpine and mediterranean quaternary, 28(1), 71-92. giraudi c. (2016) the evolution of the northernmost apennine front (piedmont, italy): plio-pleistocene sedimentation and deformation in the po basin and monferrato hills. alpine and mediterranean quaternary, 29(1), 45-65. giraudi c., mottura a., sala b., siori m.s., bormioli d. (2003) the castagnone site (cerrina valley, monferrato hills, nw italy): early pleistocene sedimentary record and biochronology. rivista italiana di paleontologia e stratigrafia, 109(3), 517-526. gsqp-gruppo di studio del quaternario padano (1976) studio interdisciplinare del "rilievo isolato" di trino (bassa pianuravercellese, piemonte), quaderno n.3, 161-253, litografia massaza e sinchetto, turin. irace a., clemente p., natalicchio m., ossella l., trenkwalder s., de luca d.a., mosca p., piana f., polino r., violanti d. (2009) geologia e idrostratigrafia profonda della pianura padana occidentale. pp. 110, 61 allegati. la nuova lito, florence. livio f., ferrario m.f., frigerio c., michetti a.m. zerboni a., bonadeo l., fioraso g., irace a., brunamonte f. (2015) late pleistocene reverse surface faulting at the pecetto di valenza site (alnorthern italy): preliminary results. conference of the gngts, sessione 1.1, 45-50. maclin m.g., fuller i.c., lewin j., maas g.s., passmore d.g., rose j., woodward j.c., black s., hamlin r.h.b., rowas j.s. (2002) correlation of late and middle pleistocene fluvial sequences in the mediterranean and their relationship to climate change. quaternary science reviews, 21, 16331644. michetti a. m., giardina f., livio f., mueller k., serva l., sileo g., vittori e., devoti r., riguzzi f., carcano c., rogledi s., bonadeo l., brunamonte f., fioraso g. (2012) active compressional tectonics, quaternary capable faults, and the seismic landscape of the po plain (northern italy). annals of geophysics, 55, 5, 969-1001. montrasio a., ragni u., bonsignore g., borgo a., zanella e., crema g., medioli f., petrucci f. (1969) carta geologica d’italia alla scala 1:100, 000, foglio 57 “vercelli”. ii ed., servizio geologico d’italia, rome. pieri m., groppi g. (1981) subsurface geological structure of the po plain, italy. quad. cnr. prog. fin. geodinamica, rome, 1-13. regione piemonte (2004) indagini e studi finalizzati alla predisposizione del piano di tutela delle acque. regione piemonte, direzione pianificazione risorse idriche. pp. 17. rovida a., camassi r., gasperini p., stucchi m. (eds.) (2011) cpti11, the 2011 version of the parametric catalogue of italian earthquakes. milano, bologna. http://emidius.mi.ingv.it/cpti. doi: 10.6092/ingv.it-cpti11. rsni regional seismic network of northwestern italy database (2014a) mappe di sismicità strumentale 1982-2013. university of genova. http://www.distav.unige.it/rsni/ita/index.html. rsni regional seismic network of northwestern italy database (2014b) mappe di sismicità storica (1000-2006). university of genova. http://www.distav.unige.it/rsni/ita/index.html sacco f. (1889) il bacino terziario e quaternario del piemonte. atti società italiana di scienze naturali, 31-32, 135-281, 289-398, 331-390. violanti d., sassone p. (2008) il pliocene del sottosuolo di casale monferrato (piemonte, italia nordoccidentale): dati preliminari. atti mus. civ. stor. nat. trieste, suppl. 53, 233-264. 103 ms. received: february 28, 2017 final text received: october 4, 2017 the morphology of the base of the alluvial sediments of the vercelli plain (piedmont, nw italy): …. �� � � 104 base stratigrafia dei depositi pleistocenico-olocenici dell’area costiera di metaponto compresa fra marina di ginosa ed il torrente cavone (italia meridionale): carta geologica in scala 1:25.000 tullio pescatore1, piero pieri2-3, luisa sabato2, maria rosaria senatore1, salvatore gallicchio2, modestino boscaino1, antonietta cilumbriello2, roberto quarantiello1 & giovanna capretto1 1dipartimento di studi geologici ed ambientali università degli studi del sannio, benevento 2dipartimento di geologia e geofisica università degli studi di bari, bari 3via pisana 313, firenze riassunto: pescatore t. et al., stratigrafia dei depositi pleistocenico-olocenici dell’area costiera di metaponto compresa fra marina di ginosa ed il torrente cavone (italia meridionale): carta geologica in scala 1:25.000. (it issn 0394-3356, 2009) al fine di migliorare le conoscenze geologico-stratigrafiche dell’area costiera metapontina, è stato svolto un rilevamento geologico di dettaglio nella zona compresa fra marina di ginosa (provincia di taranto) ed il torrente cavone (provincia di matera). il rilevamento è stato corredato da osservazioni dei caratteri di facies effettuate sia lungo sezioni stratigrafiche esposte che su sondaggi ottenuti tramite cinque perforazioni a carotaggio continuo che hanno attraversato depositi dell’olocene e del pleistocene medio superiore fino ad una profondità di circa 120 m. i depositi affioranti sono stati distinti in due principali unità: ”depositi sabbioso-conglomeratici dei prismi costieri regressivi” (pleistocene superiore) e “depositi della piana di metaponto” (olocene). i primi depositi, sabbioso-conglomeratici, sono stati suddivisi in tre unità litostratigrafiche; le prime due, spesse al massimo 15 m, e rappresentate da prismi formatisi in seguito ad interazioni fra oscillazioni del livello del mare e sollevamento regionale, sono riferibili alle “sabbie e conglomerati di policoro” e alle “sabbie e conglomerati di masseria ricotta” che, in base all’osservazione dei caratteri di facies, sono state attribuite ad ambienti variabili dal marino poco profondo al continentale. la terza unità, in discordanza sulle precedenti, è formata da un “prodotto eluviale” discontinuo e di esiguo spessore. i “depositi della piana di metaponto”, tutti di età olocenica e spessi in genere pochi metri, sono stati invece suddivisi in “depositi continentali” e “depositi di transizione”. i primi sono rappresentati da depositi da fini a grossolani, di origine eluvio-colluviale, fluviale, lacustre e palustre; i secondi invece, sono rappresentati da depositi sabbiosi e/o siltoso-argillosi di spiaggia-duna (attuali ed abbandonati) e deltizi (attuali ed abbandonati). i depositi sepolti sono stati distinti in tre unità grazie all’individuazione di due nette superfici di discontinuità. l’unità più bassa (denominata “substrato”), attraversata per uno spessore massimo di 76 m e riscontrata a partire da profondità variabili da 13 m a 44 m spostandosi da terra verso mare, è costituita da depositi argilloso-siltosi, con intercalazioni di strati sabbiosi, che verso l’alto passano a depositi sabbiosi e sabbioso-ghiaiosi. tali depositi mostrano caratteri di facies riferibili ad ambienti variabili dalla piattaforma all’avanspiaggia. l’età di questi depositi è pleistocene medio superiore. in contatto erosivo sul substrato si rinviene un’unità definita “depositi della piana sepolta di metaponto”, con geometria cuneiforme, e con spessori perforati variabili da 0 a 7 m spostandosi da terra verso mare. tale unità è formata da depositi sabbioso-ghiaiosi mostranti caratteri di facies variabili dal continentale al marino poco profondo. l’età è riferibile al pleistocene superiore. in erosione su tali depositi, o direttamente sul substrato, si rinviene infine un’unità sabbiosa e sabbioso-ghiaiosa, corrispondente ai “depositi della piana di metaponto”, con geometria cuneiforme, e con spessori che aumentano da terra verso mare, fino ad un massimo misurato di circa 48 m. l’analisi di facies ha permesso di riferire tali depositi alla progradazione di un sistema di spiaggia, a luoghi associato lateralmente ad un sistema deltizio, passante distalmente ad un sistema di piattaforma. grazie ad una datazione radiometrica effettuata su un guscio di lamellibranco rinvenuto in un sondaggio alla profondità di 35 m, è possibile riferire tali depositi all’olocene. l’insieme dei dati raccolti ha permesso di realizzare una carta geologica in scala 1:25.000 nella quale sono state cartografate numerose unità litostratigrafiche che formano un quadro nuovo e maggiormente dettagliato rispetto a quello vigente nella letteratura ufficiale. le sezioni geologiche a corredo, integrate anche con i dati dei sondaggi, consentono di ricostruire la geometria dei depositi sepolti, e di delineare la storia evolutiva del prisma olocenico nel tratto di costa considerato. abstract: pescatore t. et al., stratigraphy of the pleistocene-holocene deposits of the coastal metaponto area between marina di ginosa and cavone river (southern italy): geological map, 1:25.000 scale. (it issn 0394-3356, 2009) in order to improve the geological and stratigraphic knowledge of the metaponto coastal area a detailed geological survey has been performed between marina di ginosa (taranto) and cavone river (matera). furthermore, a facies analysis either along stratigraphic sections or on cores obtained from five continuously-cored boreholes, drilling in the holocene and middle – upper pleistocene deposits up to 120 m of depth, has been carried out. the outcropping deposits have been distinguished in: upper pleistocene “sandy-conglomeratic deposits of the regressive coastal prisms” and holocene “metaponto plain deposits”. the first deposits are subdivided into three lithostratigraphic units. the first two units have a thickness variable up to 15 m, and are represented by sandy-conglomeratic prisms resulting from the interplay between sea-level fluctuations and regional uplift; they are referred to “sabbie e conglomerati di policoro” and “sabbie e conglomerati di masseria ricotta”, showing facies features of shoreface passing upward to continental environments. the third unit, up to 2 m thick, is an “eluvial product”, made up of reddish sands with gravelly layers unconformably and discontinuously overlaying the previous deposits. the holocene “metaponto plain deposits” have been distinguished in: “continental deposits” and “transitional deposits”. continental deposits are represented by mainly some meters thick fineto coarse-grained sediments of eluvial, fluvial, lacustrine and palustrine environments. transitional deposits are represented by some meters thick sandy and silty holocene beach-dune systems (modern and ancient) and sandy and clayey-silty deltaic systems (modern and ancient). the buried deposits of the metaponto coastal area have been distinguished in three units thanks to the facies analysis and mainly to il quaternario italian journal of quaternary sciences 22(2), 2009 307-324 308 t. pescatore et al. 1. premessa nell’ambito del progetto di ricerca prin-miur dal titolo: “storia geologica delle piane costiere di metaponto e di sibari durante il pleistocene superioreolocene. fattori climatici ed eventi catastrofici” di cui è stato coordinatore scientifico nazionale il prof. tullio pescatore, le unità di ricerca delle università di bari e di benevento hanno realizzato una carta geologica in scala 1:25.000 della parte di fascia costiera ionica metapontina ubicata tra l’abitato di marina di ginosa (provincia di taranto) ed il torrente cavone (provincia di matera). l’area rilevata ha un’estensione totale di circa 125 kmq, una lunghezza di circa 21 km (parallelamente alla linea di costa), ed un’ampiezza di 6 km. si tratta di un’area morfologicamente piatta, dove le quote variano dal livello del mare (linea di costa) fino ad un massimo di circa 35 m. i depositi affioranti, di età pleistocene superiore-olocene, sono essenzialmente rappresentati da depositi fini e solo in minore quantità da depositi sabbioso-conglomeratici. l’interesse per quest’area risiede in più di un motivo: presenta una notevole importanza archeologica, in quanto sede di insediamenti della magna grecia; è stata oggetto di complesse opere di bonifica, che hanno determinato la sua trasformazione in un’area a vocazione agricola con colture di grande pregio; è oggetto di ampi interventi di pianificazione e trasformazione territoriale legati ad una significativa espansione dell’offerta turistica con costruzione di villaggi a ridosso dell’area costiera, oltre a porticcioli in corrispondenza delle principali foci fluviali. a tale proposito, qualsiasi intervento venga progettato non dovrebbe prescindere da una dettagliata conoscenza geologica dei depositi affioranti e di quelli dell’immediato sottosuolo, in quanto un’area costiera, come quella metapontina, risulta estremamente sensibile a fenomeni quali eustatismo e/o subsidenza, variazioni climatiche, processi marini estremi (mareggiate e tsunami) ed alluvioni, le cui registrazioni nella serie sedimentaria possono suggerire la naturale tendenza evolutiva del territorio e la potenziale attività di processi geologici non sempre riconoscibili solo da dati storici. al fine quindi di fornire una corretta informazione di base, utile anche a scopi applicativi, e di dettagliare il quadro stratigrafico dei depositi della piana di metaponto, è stato realizzato un rilevamento geologico utilizzando sia basi topografiche alla scala 1:2.000 del consorzio della bonifica di metaponto (ente attualmente compreso nel consorzio di bonifica di bradano e metaponto) che ortofotocarte alla scala 1:10.000 della regione basilicata, riportando poi i dati su materiale cartografico dell’igm alla scala 1:25.000, così come qui presentato. come detto, essendo tale area intensamente antropizzata, l’individuazione di alcune morfologie costiere è stata possibile anche grazie all’ausilio sia di una carta geomorfologica prodotta dalla regione basilicata (boenzi et al., 2002), sia dell’analisi di strisciate di foto aeree alla scala 1:33.000 di differenti annate, dal 1954 al 1998; a tal proposito, fra l’altro, è stato possibile individuare antiche morfologie di alvei abbandonati e i più marcati fenomeni di arretramento costiero localizzati in corrispondenza delle foci dei fiumi cavone, basento e bradano, elementi di analisi che trovano accordo con alcuni dati di letteratura (e.g. cocco et al., 1975; capretto, 2003; spilotro, 2004). l’insieme delle informazioni raccolte ha permesso di realizzare una carta geologica dell’area costiera di metaponto nella quale sono rappresentati anche gli elementi morfologici che insieme a quelli deposizionali documentano la dinamica costiera recente ed attuale. inoltre, al fine di meglio caratterizzare i depositi sepolti della porzione di piana costiera metapontina studiata, e che rappresentano anche i terreni di fondazione di numerose opere, nell’ambito dello stesso progetto sono stati realizzati cinque sondaggi di cui qui si presentano i dati litostratigrafici. lungo uno di questi sondaggi è stata effettuata anche una datazione con il metodo radiometrico 14c al fine di definire l’età dei depositi studiati. l’integrazione dei dati di superficie con quelli di profondità ha permesso di fornire un quadro stratigrafico nuovo e dettagliato dell’area metapontina, di definire i caratteri deposizionali ed evolutivi delle principali unità stratigrafiche individuate, e di contribuire alla conoscenza delle ultime fasi evolutive del bacino della fossa the recognition of two important erosional surfaces. the lower unit (called substratum), found beginning from a depth variable from 13 m to 44 m moving seaward, is at least 76 m thick and made up of clayey-silty deposits, with interbedded sandy beds passing landward and upward to sandy and/or sandy-gravelly deposits. the lower boundary was not found, whilst the upper boundary is represented by an erosional surface (se) highlighted by a lag deposit. the facies features of these deposits can be referred to offshore passing upward to shallow marine environments. the age is middle late pleistocene. the intermediate unit is bounded both on bottom and on top by erosional surfaces (se and st). this intermediate upper pleistocene wedge-shaped unit, called “metaponto buried plain deposits”, pinches out landward, passing from about 7 m to 0 m in thickness. it is made up of sandy-gravelly deposits of continental to shallow marine environments. the third upper unit erosionally overlies both the previous unit and the substratum by the st surface. this unit is made up of sands and gravelly sands, and its thickness varies from 13 m to 48 moving seaward, and has been attributed to the progradation of a beach system, laterally linked to a deltaic system, and passing seaward to an offshore system. a lamellibranch shell yielded a not calibrated 14c age of 7.572±50 yr bp for these deposits. the overall collected data allow us to draw a geological map on 1: 25.000 scale that provides a new stratigraphic framework of the outcropping metaponto plain deposits. furthermore, the geological sections obtained also utilizing the boreholes allow us both to reconstruct the geometry of the buried deposits and to outline the evolutionary history of the holocene transgressive prism along the coastal study area. parole chiave: piana di metaponto, pleistocene superiore-olocene, caratteri stratigrafici, italia meridionale. keywords: metaponto plain, late pleistocene-holocene, stratigraphic features, southern italy. bradanica durante l’intervallo temporale pleistocene superiore-olocene in buon accordo con cilumbriello et al. (in stampa) e sabato et al. (in prep.). si fa presente che simili studi sono già stati condotti da alcuni autori di questa nota per l’analisi di altre piane costiere (barra et al. 1999; pescatore et al., 2001; pescatore & senatore, 2003). 2. inquadramento geologico l’area in oggetto è ubicata nella piana metapontina, prospiciente il golfo di taranto, ed è compresa tra la foce del torrente cavone (in provincia di matera) e l’insediamento di marina di ginosa (in provincia di taranto) (fig. 1). tale area ricade in parte nel f° 201 “matera” (boenzi et al., 1971), ed in parte nel f° 212 “montalbano ionico” (mostardini & pieri, 1967) della carta geologica d’italia alla scala 1:100.000. da un punto di vista geologico-strutturale l’area suddetta corrisponde all’estrema propaggine meridionale della fossa bradanica (e.g. migliorini, 1937), dove affiorano i cosiddetti depositi marini terrazzati (sensu vezzani, 1967) localmente di età pleistocene superiore, e depositi sabbiosi, sabbioso-ghiaiosi e sabbioso-limosi della piana costiera ionica di età olocenica. depositi attribuibili al pleistocene superiore-olocene sono stati individuati anche nella zona marina prospiciente l’area in studio (diplomatico et al., 1985; senatore, 1987; senatore et al., 1988). i primi approfondimenti sui caratteri stratigrafici 309stratigrafia dei depositi pleistocenico-olocenici dell’area costiera ... dei depositi marini terrazzati risalgono alla seconda metà degli anni ‘60 (cotecchia & magri, 1967; vezzani, 1967). in particolare, vezzani (1967) individua 7 ordini di terrazzo, che abbracciano un intervallo di tempo compreso fra il siciliano e il tirreniano; il deposito marino terrazzato del 1° ordine che è il più alto ed il più antico, si ritrova ad una quota di circa 390 m, quello del 7° ordine è il più recente e si rinviene ad una quota di 1015 m s.l.m. successivamente, per gli stessi depositi, altri autori individuano un numero di superfici e di ordini di terrazzi differente, da un minimo di 7 ad un massimo di 11 (neboit, 1975; boenzi et al, 1976; brückner, 1980a, 1980b; amato, 2000). in particolare brückner (1980a; 1980b; 1982) compie uno studio morfologico di dettaglio ed individua nell’area metapontina 11 ordini di depositi identificati con la sigla da t1 a t11 a partire da quello più basso; inoltre brückner (opp. cit.) effettua le prime datazioni dei depositi marini terrazzati, riconoscendo il limite paleomagnetico brunhes/matuyama tra i terrazzi t11 e t10, datando a 500-600 ka bp un livello vulcanoclastico nella parte alta del terrazzo t8, ed infine attribuendo un’età di 63 ka bp (± 3 ka) al terrazzo marino più basso (t1) attraverso il metodo th230/234u. fatta eccezione per bentivenga et al. (2004), che considerano i depositi marini terrazzati come formatisi per fagliamento di un unico ampio originale deposito costiero del pleistocene medio, la maggior parte degli autori interpreta i depositi marini terrazzati, indipendentemente dal loro numero, come la conseguenza del sollevamento dell’area del bacino di avanfossa a partire dal pleistocene medio. tale sollevamento avrebbe profig. 1a) carta strutturale schematica d’italia; b) carta geologica schematica della fossa bradanica; c) carta geologica schematica dei depositi marini terrazzati e della piana costiera metapontina affioranti nella porzione meridionale della fossa bradanica (da cilumbriello et al., 2008, leggermente modificata); d) carta schematica dell’area studiata con ubicazione dei sondaggi e delle sezioni geologiche effettuate. a) schematic structural map of italy; b) schematic geological map of the bradanic trough; c) schematic geological map of the terraced marine deposits and the metaponto coastal plain deposits cropping out in the southern area of bradanic trough (from cilumbriello et al., 2008, slightly modified); d) schematic map of the study area with location of the core-drillings and the geological sections. 310 vocato l’esposizione ed erosione della parte alta della serie di riempimento della fossa bradanica e la formazione, in seguito alle variazioni cicliche quaternarie del livello del mare, di una serie di terrazzi marini in discordanza sulla successione della fossa bradanica affiorante (argille subappennine) (selli, 1962, vezzani, 1967; boenzi et al., 1971; parea, 1986). più recentemente cilumbriello (2008) e cilumbriello et al. (2008) tramite studi stratigraficosedimentologici dettagliati su depositi affioranti in parte nell’area in oggetto hanno evidenziato come ogni deposito marino terrazzato riconosciuto dagli autori precedenti non sia semplicemente relativo ad un unico ciclo trasgressivo-regressivo, come inteso classicamente, ma presenti una ciclicità interna di più alta frequenza. nel complesso quindi, l’intera successione riferita ad un deposito terrazzato non sarebbe geneticamente correlabile alla superficie terrazzata che la delimita superiormente (cilumbriello, 2008). per tali motivi, nei lavori svolti per la realizzazione della nuova carta geologica d’italia alla scala 1:50.000 i depositi marini terrazzati sono stati denominati genericamente come prismi costieri regressivi (sabato et al., in prep). va infine ricordato che studi di carattere stratigrafico regionale (pieri et al., 1994; 1996; tropeano et al., 2002a; 2002b) suggeriscono di non operare più distinzioni fra i depositi di colmamento della fossa bradanica ed i depositi marini terrazzati, e li attribuiscono nel loro insieme ad un’unica unità definita informalmente “depositi costieri regressivi della fossa bradanica” (fig. 1b, c). in questa ottica, i depositi marini terrazzati rappresenterebbero i termini più recenti di riempimento della fossa bradanica. per quanto riguarda l’area di studio, i depositi marini terrazzati affioranti corrispondono a parte del deposito marino terrazzato di 7° ordine sensu vezzani (1967), o a parte del deposito marino terrazzato di i ordine sensu brückner (1980a; 1980b). nell’ambito della realizzazione del foglio geologico n° 508 “policoro” alla scala 1:50.000 sabato et al. (in prep.) attribuiscono gli stessi depositi in parte all’unità delle “sabbie e conglomerati di policoro” ed in parte all’unità delle “sabbie e conglomerati di masseria ricotta”. per quanto riguarda invece i depositi della piana costiera, una loro prima descrizione si deve a vezzani (1967), oltre che a mostardini & pieri (1967) e a boenzi et al. (1971), ed in tempi più recenti a capretto (2003). vezzani (op. cit.), nell’area compresa tra i depositi marini terrazzati più recenti e i cordoni dunari più interni, descrive una successione sedimentaria di sabbie, sabbie argillose e ghiaie, con spessore variabile da 20 m a 40 m, depositatasi sulle “argille marnose azzurre” del calabriano (argille subappennine sensu valduga, 1973) in seguito all’alternanza di condizioni continentali e marine. l’età di questa successione viene riferita al post-tirreniano da vezzani (op. cit.), che inoltre descrive le dune costiere e le spiagge attuali che occupano la fascia litorale. secondo tale autore le dune costiere sono costituite da sabbia fine di colore variabile dal grigio al giallastro e formano una fascia di cordoni paralleli all’attuale linea di costa con ampiezza che aumenta da s verso n fino ad un massimo di 2 km a n di marina di ginosa, dove le dune raggiungono altezze fino a 13 m. l’autore descrive infine una spiaggia sabbiosa attuale di ampiezza variabile da 10 m a 200 m in cui riconosce gli ambienti di avanspiaggia, cordone di spiaggia e retrospiaggia sensu shepard (1948). i caratteri delle dune costiere e delle spiagge attuali sono stati descritti in dettaglio da cocco et al. (1975); questi autori nel tratto di costa compreso tra il torrente cavone e l’abitato di marina di ginosa descrivono un’unità fisiografica rappresentata da spiagge sabbiose delimitate verso terra da una fascia ampia fino a 2 km costituita da cordoni dunari (alti fino ad oltre 10 m) ed aree acquitrinose. le spiagge, rappresentate da sabbie a grana medio fine e a composizione quarzosa, si sviluppano con ampiezza variabile da 20 m a 70 m e sono caratterizzate da una pendenza che per la spiaggia emersa è dell’ordine dei 6° e per la battigia è di circa 9°. localmente vengono segnalati anche tratti in forte arretramento delimitati verso terra da scarpate incise nelle dune con altezza di oltre 3 m. gli elementi morfologici del tratto di piana costiera ionica ricadente nella regione basilicata sono stati rappresentati con estremo dettaglio nell’ambito di uno studio effettuato per un progetto della regione basilicata, finalizzato alla salvaguardia e alla difesa del litorale ionico (boenzi et al., 2002). in particolare è stata prodotta una carta geomorfologica alla scala 1:25.000 in cui si evincono tra l’altro i principali elementi geomorfologici che hanno caratterizzato l’evoluzione della fascia costiera ionica negli ultimi 3.000 anni e i caratteri evolutivi della linea di riva attuale (in arretramento, in equilibrio e in avanzamento) per quanto riguarda invece i caratteri litostratigrafici dei depositi sepolti della piana costiera, questi vengono descritti sulla base di indagini geognostiche effettuate in prossimità della foce del fiume sinni da cotecchia et al. (1969) che, in corrispondenza del paleoalveo il cui riempimento mostra uno spessore di circa 64 m ed un’età non più antica di 11.170 ± 160 anni, descrivono una successione di depositi alluvionali che poggia in discontinuità sul substrato argilloso a hyalinea balthica (argille subappennine). la datazione delle porzioni più recenti della stessa successione si deve al ritrovamento in sondaggi, a circa 3 m di profondità, di resti archeologici che risalgono ad un periodo di tempo compreso tra il vii ed il iii sec. a.c. (boenzi et al., 1987 e citazioni contenute). una prima ricostruzione del tetto del substrato argilloso (argille subappennine) sul quale poggia la successione della piana costiera viene fornita da spilotro (2004) che, attraverso numerosi dati di pozzo, individua una superficie più o meno ondulata posta ad una profondità media di 20÷30 m interrotta, in corrispondenza dei principali corsi d’acqua attuali, da paleoalvei con profondità variabile da poco più di 60 m in corrispondenza del fiume sinni ad oltre 120 m in corrispondenza del fiume bradano. per quanto riguarda l’evoluzione olocenica dei depositi sepolti al di sotto della piana di metaponto capretto (2003), attraverso un rilievo di superficie, l’analisi di nove sondaggi e applicando anche concetti di stratigrafia sequenziale, riconosce una successione spessa al massimo 50 m, in cui sono registrati sia la fase di trasgressione che la successiva fase di stazionamento alto. più recentemente, a seguito dei lavori di aggiornamento della carta geologica d’italia in scala 1:50.000 t. pescatore et al. 311 (foglio 508 “policoro” – progetto carg basilicata) gallicchio et al. (2008) descrivono i nuovi dati di superficie e di profondità ottenuti nell’area compresa tra i fiumi basento e cavone. in base agli stessi dati cilumbriello et al. (in stampa) e sabato et al. (in prep.), grazie anche all’analisi di numerosi sondaggi eseguiti in proprio e recuperati da enti pubblici e di ricerca, propongono una correlazione e suddivisione dei depositi sepolti riconoscendo in particolare un corpo (piana costiera sepolta – pcs) intercalato tra il “substrato” ed il prisma olocenico. tale corpo, irregolare, discontinuo e a geometria complessa, possiede spessori molto variabili, fino ad un massimo di circa 70 m in corrispondenza di paleoincisioni, mentre nelle aree intervallive è spesso pochi metri e mostra geometria cuneiforme. 3. stratigrafia dei depositi affioranti il rilevamento geologico svolto nella piana metapontina ha permesso di individuare e cartografare differenti unità l itostratigrafiche di età variabile dal pleistocene superiore all’olocene. per quanto riguarda i sedimenti riferiti in letteratura al deposito marino terrazzato più basso, quello posto a ridosso dell’area costiera, e di età pleistocene superiore, si è fatto riferimento alla suddivisione stratigrafica utilizzata nella nuova cartografia geologica del f° 508 policoro in scala 1:50.000 (sabato et al., in prep.); pertanto tali depositi risultano riferibili ai “depositi sabbioso-conglomeratici dei prismi costieri regressivi”, suddivisi in tre unità informali indicate con i termini di “sabbie e conglomerati di policoro”, “sabbie e conglomerati di masseria ricotta”, e “prodotto eluviale”. i restanti depositi, indicati come “depositi della piana di metaponto” sono invece stati distinti in “depositi continentali” e “depositi di transizione”. i “depositi continentali” sono di età olocenica, e sono stati suddivisi in: “deposito alluvionale delle aree esondabili”, “deposito lacustre e/o palustre”, “deposito alluvionale recente ed attuale” e “coltre eluvio colluviale”. i “depositi di transizione”, anche questi olocenici, si distinguono in una serie di sistemi deltizi e di spiaggia/duna, dove quelli più antichi sono più interni ed ormai abbandonati, in quanto non più attivi, mentre quelli attuali sono prospicienti alla linea di costa. si sottolinea che, per i nomi attribuiti alle unità e per le sigle utilizzate, si è fatto riferimento alle indicazioni fornite dall’ispra, riportate nei quaderni del servizio geologico d’italia (s.g.n., 1992; 1994; 1995; 1996; 1997; 2003 e successivi aggiornamenti). per le attribuzioni agli ambienti sedimentari si è invece fatto riferimento alle suddivisioni utilizzate da massari (1988) in un lavoro relativo alle facies paraliche. 3.1 depositi sabbioso-conglomeratici dei prismi costieri regressivi come detto, nell’area studiata i “depositi sabbioso-conglomeratici dei prismi costieri regressivi” sono suddivisi in tre unità litostratigrafiche. le prime due sono riferibili alle “sabbie e conglomerati di policoro” (ocr) e alle “sabbie e conglomerati di masseria ricotta” (rit). queste unità presentano una morfologia terrazzata, nel senso che sono delimitate superiormente da una superficie pianeggiante e frontalmente da una scarpata che corre parallelamente alla linea di riva della costa ionica. le unità litostratigrafiche su indicate corrispondono, secondo la cartografia geologica ufficiale al terrazzo marino del 7° ordine sensu vezzani (1967) o al terrazzo marino del i ordine sensu brückner (1980a; 1980b; 1982). in discordanza su entrambe le unità si osserva un “prodotto eluviale” (b6) sabbioso-ghiaioso di esiguo spessore e scarsa continuità laterale. l’età dei depositi che costituiscono i prismi costieri regressivi è riferita in letteratura al pleistocene superiore (opp. cit.). 3.1.1 sabbie e conglomerati di policoro (ocr) questa unità affiora in corrispondenza di una fascia che corre lungo il limite occidentale dell’area rilevata ed è limitata superiormente da un ripiano terrazzato che si sviluppa tra le quote di circa 25 m (verso mare) e 35 m s.l.m. (verso l’entroterra); tale ripiano è interrotto trasversalmente in corrispondenza delle incisioni dei principali corsi d’acqua che sfociano sulla costa ionica. gli affioramenti principali sono rappresentati essenzialmente da depositi sabbioso-conglomeratici, con uno spessore massimo di 15 m. lo studio stratigrafico-sedimentologico effettuato lungo alcune sezioni stratigrafiche (cilumbriello, 2008; sabato et al., in prep.) ha permesso di riconoscere associazioni di facies variabili dal marino poco profondo al continentale e di suddividere la successione delle “sabbie e conglomerati di policoro” in due porzioni: una porzione inferiore costituita essenzialmente da un’alternanza di sabbie e lenti ghiaiose per uno spessore medio di circa 6 m, ed una porzione superiore costituita da un corpo conglomeratico clinostratificato con uno spessore medio di circa 4 m passante a depositi prevalentemente sabbiosi spessi circa 5 m. la porzione inferiore è caratterizzata da sabbie medio-fini a laminazione obliqua concava a piccola e grande scala e rari ciottoli allineati lungo le lamine. localmente le sabbie contengono lenti siltose e/o argillose spesse pochi centimetri. le lenti ghiaiose, a base erosiva e con spessori variabili fino a un massimo di 70 cm, sono a tessitura clasto-sostenuta, e in genere disorganizzate, con ciottoli eterometrici (da piccoli ciottoli a rari massi) e di forma arrotondata (subsferici soprattutto, ma anche appiattiti). sia nei sedimenti sabbiosi che nelle lenti ciottolose, si rinviene una fauna mal conservata, all’interno della quale è possibile riconoscere bivalvi disarticolati, talora come modelli o gusci parzialmente disciolti oltre a modelli di gasteropodi indeterminabil i . i bivalvi sono rappresentati da aequipecten opercularis, acanthocardia tuberculata, ostrea edulis, glycymeris sp., oltre che da specie indeterminabili delle famiglie veneridae e tellinidae. in base ai caratteri di facies questi depositi si possono attribuire ad ambienti di spiaggia sommersa. la porzione superiore si apre con depositi conglomeratici clinostratificati, immergenti verso mare con angoli variabili da un massimo di 25° (parte basale) fino a pochi gradi (parte alta). tali depositi contengono ciottoli ben selezionati, appiattiti ed embriciati; inoltre sono presenti rare intercalazioni di strati sabbiosi, a geometria cuneiforme. i caratteri di facies descritti permettono di attribuire questi depositi ad ambienti di avanspiaggia ghiaiosa. la successione si chiude con sabbie molto stratigrafia dei depositi pleistocenico-olocenici dell’area costiera ... 312 fini, in genere massive con rare intercalazioni di lenti ghiaiose per uno spessore di circa 5 m. questi depositi vengono attribuiti ad ambienti di piana alluvionale. l’età di questa unità può essere genericamente riferita al pleistocene superiore (brückner, 1980a; 1980b; 1982). 3.1.2 sabbie e conglomerati di masseria ricotta (rit) i depositi relativi alle ”sabbie e conglomerati di masseria ricotta” si rinvengono in un’area di limitata estensione a partire dalla destra orografica del torrente cavone fino a no di metaponto (nei pressi della necropoli). costituiscono una stretta fascia che corre circa parallelamente all’attuale linea di costa ed è limitata superiormente da un ripiano terrazzato che si sviluppa tra le quote di 10 m (verso mare) e 15 m s.l.m. (verso l’entroterra). i depositi sottostanti tale ripiano sono costituiti da una successione sabbioso-conglomeratica con spessore massimo di circa 13 m. l’analisi litostratigrafica effettuata lungo alcune sezioni stratigrafiche (cilumbriello, 2008; sabato et al., in prep.) ha messo in evidenza che la successione è costituita da associazioni di facies riferibili ad ambienti variabili dal marino poco profondo al continentale. in particolare, nell’ambito di tale unità, sono state riconosciute una porzione inferiore prevalentemente sabbiosa ed una porzione superiore prevalentemente conglomeratica. la porzione inferiore, di spessore variabile da un paio di metri a circa una decina di metri, è costituita da sabbie a granulometria da fine a molto fine, con laminazione da obliqua a basso angolo (hummocky crossstratification) a piano-parallela, con intercalazioni di strati argillosi, che passano verso l’alto a sabbie mediofini, con lenti ghiaiose a base erosiva. all’interno si rinviene una fauna molto mal conservata. sono presenti modelli di bivalvi (cardiidae, veneridae e tellinidae), oltre a gusci disarticolati di ostreidae. nell’insieme questi depositi sono stati attribuiti ad ambienti di spiaggia sommersa. la porzione superiore è costituita da depositi prevalentemente conglomeratici con rare intercalazioni di strati sabbiosi, con uno spessore variabile da circa 1 m a 5÷6 m. tale porzione è clinostratificata, e caratterizzata da clinoformi inclinati verso mare con angoli variabili dal basso verso l’alto da 22° a 3°. complessivamente questi depositi sono ben organizzati e costituiti da ciottoli ben selezionati, ben appiattiti e ben embriciati. gli strati sabbiosi sono costituiti da sabbie medio-fini, ben selezionate e a laminazione obliqua planare a basso angolo. a luoghi all’interno di questi strati si rinvengono gusci di bivalvi interi (glycymeris sp., ostrea edulis) ed in frammenti. in base all’analisi di facies questi depositi sono attribuiti ad ambienti di avanspiaggia ghiaiososabbiosa. localmente, su questi depositi si rinvengono, con spessore inferiore al metro, depositi argillosi, ricchi di frustoli vegetali, in genere massivi e fortemente alterati, e depositi sabbiosi, con spessori dell’ordine di un paio di metri con rare intercalazioni di strati ciottolosi a base erosiva. nell’insieme tali depositi sono riferibili ad ambienti continentali ed in particolare, i primi possono essere attribuiti ad ambienti lagunari e/o di retrospiaggia mentre i secondi ad ambienti di piana alluvionale. questa unità è stata attribuita al pleistocene superiore (brückner, 1980a; 1980b; 1982). 3.1.3 prodotto eluviale (b6) si rinviene in maniera discontinua nelle aree depresse e/o sub-pianeggianti costituite dalle superfici terrazzate dei depositi sabbioso-conglomeratici delle precedenti unità, sulle quali poggia in erosione; si tratta di sabbie limose di colore rossastro con sottili livelli ghiaiosi. i clasti hanno dimensioni dell’ordine del centimetro, sono poligenici e mediamente arrotondati. lo spessore di tale deposito è al massimo di circa un paio di metri. l’età è riferibile al pleistocene superiore. 3.2 depositi della piana di metaponto i “depositi della piana di metaponto” si sviluppano essenzialmente dalla base della scarpata che delimita inferiormente l’area dei prismi costieri regressivi fino alla linea di riva della costa ionica. si distinguono in: “depositi continentali” e “depositi di transizione”. 3.2.1 depositi continentali la suddivisione dei depositi continentali, eseguita essenzialmente sulla base dei meccanismi genetici e della posizione stratigrafica, ha permesso di distinguere le seguenti unità di età olocenica: “deposito alluvionale delle aree esondabili”, “deposito lacustre e/o palustre”, “deposito alluvionale recente ed attuale” e “coltre eluvio colluviale”. l’origine di tali depositi è dovuta prevalentemente all’attività dei principali corsi d’acqua presenti nell’area (torrente cavone e fiumi basento e bradano), nonché alla presenza di laghetti effimeri ed aree palustri di limitata estensione, che si sviluppano in prossimità delle foci dei fiumi e/o nelle aree interdunari e nelle aree depresse della piana alluvionale; solo in alcuni casi tali depositi derivano da processi di degradazione ed erosione di sedimenti relativamente più interni ed antichi. 3.2.1.1 deposito alluvionale delle aree esondabili (bn) tale deposito occupa le porzioni interne della piana metapontina; verso terra si estende oltre la base della scarpata che delimita i depositi dei prismi costieri regressivi, occupando le incisioni che tagliano trasversalmente i prismi stessi, mentre verso mare si estende fino alle spalle dei cordoni dunari più interni dei sistemi spiaggia/duna abbandonati. il settore occupato da questo deposito è rappresentato da un’area pianeggiante che sebbene più elevata di alcuni metri rispetto all’alveo dei corsi d’acqua, può essere soggetta, anche se parzialmente, ad alluvionamenti in occasione di eventi meteorici eccezionali. i caratteri litostratigrafici sono stati osservati in corrispondenza dei sondaggi effettuati nell’area in oggetto; tale deposito, il cui spessore risulta dell’ordine di pochi metri (da 3÷4 m fino a circa 10 m), è costituito essenzialmente da strati spessi al massimo un paio di metri di sabbie a granulometria molto fine e/o medio-fine, con una caratteristica colorazione giallastra, a cui si intercalano livelli ghiaiosi discontinui e di spessore limitato. al suo interno si riconoscono resti di gusci di gasteropodi terrestri (helicidae) e noduli calcarei. in prossimità dei principali corsi d’acqua (torrente cavone, fiumi basento e bradano) si riconoscono corpi limoso-argillosi. i caratteri di facies permettono di riferire tale deposito ad ambienti di origine alluvionale, ed in particolare i corpi limoso-argillosi sono relativi al riempimento di alvei meandriformi abbandonati. localmente, t. pescatore et al. alla base della scarpata dei depositi sabbioso-conglomeratici dei prismi costieri regressivi il deposito alluvionale delle aree esondabili presenta chiari caratteri morfologici riferibili a corpi di conoide alluvionale, che si sviluppano in corrispondenza dello sbocco nella piana di piccoli affluenti dei principali corsi d’acqua. tali corpi sono stati indicati in carta con l’apposito simbolo suggerito dai quaderni del servizio geologico d’italia (s.g.n., 1992, 1994; 1995; 1996; 1997; 2003 e successivi aggiornamenti). l’età di tale deposito è riferibile all’olocene; in particolare, ad una profondità di 3 m sono stati rinvenuti resti archeologici dell’età greca, riferibili a 3.000 anni fa (boenzi et al., 1987). 3.2.1.2 deposito lacustre e/o palustre (e2, e3) tale deposito si ritrova nelle aree interdunari ed in prossimità delle aree di foce abbandonate (torrente cavone e fiumi basento e bradano). si tratta di sedimenti sabbiosi e/o argilloso-siltosi. le sabbie presentano una colorazione nerastra, granulometria da grossolana a medio-fine e sono ricche di resti vegetali, oltre che di lamellibranchi interi (cerastoderma glaucum) ed in frammenti e di gasteropodi in frammenti. i sedimenti argilloso-siltosi hanno colore grigio scuro, sono molto alterati e da quanto si evince dall’analisi dei sondaggi che li hanno attraversati, costituiscono strati spessi da meno di mezzo metro ad un paio di metri. la porzione affiorante, nel periodo estivo, è caratterizzata da strutture di essiccamento (mud cracks). tali sedimenti rappresentano antichi bacini lacustri prosciugati e bonificati (e2), ma ancora oggi soggetti ad allagamenti durante fenomeni di precipitazioni intense, e/o paludi erbacee stagionali (e3), talvolta presenti tra un cordone litorale e l’altro. lo spessore è di circa 2 m. l’età di questo deposito è riferibile all’olocene. 3.2.1.3 deposito alluvionale recente ed attuale (b) tale deposito, spesso pochi metri, è localizzato lungo le aste dei principali fiumi che attraversano l’area in oggetto (torrente cavone, fiumi basento e bradano) e ne rappresenta le barre e le aree di esondazione. si tratta di sabbie limose e limi con intercalazioni di lenti ghiaiose di modesta estensione. localmente le aree di affioramento risultano antropizzate. l’età è stata riferita all’olocene. 3.2.1.4 coltre eluvio colluviale (b2) si rinviene nella zona di passaggio tra i depositi sabbioso-conglomeratici dei prismi costieri regressivi e i depositi della piana di metaponto. si tratta di limi e sabbie di colore rosso bruno, e di ghiaie costituite da clasti poligenici da arrotondati a spigoli vivi, con dimensioni variabili da pochi millimetri al decimetro. lo spessore è dell’ordine metrico. l’età è stata riferita all’olocene. 3.2.2 depositi di transizione tali depositi rappresentano sistemi costieri legati all’attività dei corsi d’acqua e dei processi marini che hanno agito durante l’olocene, fino all’attuale. si tratta quindi di una serie di depositi deltizi e depositi del sistema spiaggia/duna, che ringiovaniscono procedendo dall’interno verso la costa. insieme rappresentano una fascia stretta ed allungata parallelamente alla costa. in particolare sono state distinte le seguenti unità: “deposito deltizio abbandonato”, ”deposito di spiaggia/duna abbandonato”, “deposito deltizio attuale”, ”deposito di spiaggia/duna attuale”. le prime tre unità sono riferibili alle “sabbie e silt di metaponto”, l’ultima unità al “deposito di spiaggia attuale”, distinti nell’ambito del f° 508 policoro (sabato et al., in prep.). 3.2.2.1 deposito deltizio abbandonato (g1b) tale deposito si riconosce in prossimità delle foci dei principali corsi d’acqua ed è costituito da sedimenti siltoso-argillosi con intercalazioni sabbiose e da sabbie formatisi in seguito a fenomeni di esondazione alla foce dei principali corsi d’acqua (g1b). si distinguono inoltre aree acquitrinose e palustri (e3b) costituite da sedimenti siltoso-argillosi e corpi prevalentemente sabbiosi che rappresentano antiche barre di foce (fb). lo spessore massimo, osservato in trincea, è di pochi metri. l’età è riferibile all’olocene. 3.2.2.2 deposito di spiaggia/duna abbandonato (g2, d)n questa unità caratterizza una fascia di ampiezza variabile da poche centinaia di metri al chilometro, ed è compresa tra il deposito alluvionale delle aree esondabili (bn) e il deposito di spiaggia/duna attuale. si tratta di depositi sabbiosi e siltoso-argillosi (g2, d)n, riferibili ad antichi sistemi deposizionali formati da cordoni dunari sabbiosi e aree retrodunali siltoso-argillose, difficilmente distinguibili gli uni dalle altre a causa dell’intensa antropizzazione. solo localmente è stato possibile distinguere e cartografare diversi ordini di cordoni dunari sabbiosi abbandonati caratterizzati essenzialmente dalla presenza di dune eoliche con altezze dell’ordine di 4÷5 m intervallate da aree depresse, sedi attualmente di acquitrini effimeri; in tal caso ciascun ordine è stato indicato in carta con le sigle (g2, d)b-g, con le lettere a pedice che indicano in ordine alfabetico i cordoni litorali dai più recenti ai più antichi. in genere si tratta di sabbie medio-fini che si alternano a sabbie fini siltose, al cui interno si rinvengono frequenti bivalvi appartenenti alle famiglie cardiidae, veneridae e tellinidae, e rari ciottoli. il deposito di spiaggia/duna abbandonato più interno (g2, d)g è caratterizzato da sabbie medio-grossolane, debolmente arrossate, debolmente cementate (località tufarelle) e ricche in frammenti di gusci di bivalvi. lo spessore è di circa 5 m. l’età è riferibile all’olocene. 3.2.2.3 deposito deltizio attuale (g1a) tale unità si ritrova in corrispondenza delle foci dei principali corsi d’acqua presenti nell’area ed è rappresentata da sedimenti siltoso-argillosi con intercalazioni sabbiose che costituiscono l’attuale zona di esondazione alla foce dei principali corsi d’acqua (g1a). localmente si distinguono sedimenti prevalentemente limosi costituenti aree acquitrinose e palustri (e5) e sedimenti prevalentemente sabbiosi costituenti barre di foce emerse (fa). lo spessore è di pochi metri. l’età è riferibile all’olocene. 3.2.2.4 deposito di spiaggia/duna attuale (g2, d)a tale deposito si ritrova lungo una fascia costiera larga da pochi metri fino ad un massimo di alcune deci313stratigrafia dei depositi pleistocenico-olocenici dell’area costiera ... ne di metri, che corre parallelamente alla linea di riva. la parte più interna è rappresentata da dune eoliche (da) la cui altezza è di circa 1÷2 m; le dune sono costituite da sabbia fine, le cui strutture sedimentarie, osservabili in corrispondenza dei tratti di costa in erosione, sono rappresentate essenzialmente da laminazione obliqua ad alto angolo. verso mare si osserva il tratto di costa rappresentato dalla spiaggia emersa (g2a), caratterizzata da un profilo molto dolce e costituita da sabbia medio-fine ben selezionata, a laminazione da piano-parallela ad obliqua, leggermente inclinata verso terra. in questo deposito si ritrovano concentrazioni di bivalvi delle famiglie cardiidae, veneridae e tellinidae. lo spessore è dell’ordine di un paio di metri. tale deposito è riferibile all’olocene. 4. i depositi sepolti della piana di metaponto nell’ambito del progetto di ricerca richiamato nell’introduzione, sono stati eseguiti cinque sondaggi a carotaggio continuo. due sondaggi sono stati eseguiti dall’unità operativa dell’università di bari nell’area compresa tra il fiume basento ed il torrente cavone, lungo la strada provinciale che collega la ss 106 al “lido quarantotto”, in località “panetta”: sondaggio lazazzera (lz), e sondaggio casa sotto le stelle (cs). tre sondaggi sono stati eseguiti dall’unità operativa dell’università del sannio a nord del fiume bradano: sondaggio ginosa 01 (s1), sondaggio ginosa 02 (s2) e sondaggio ginosa 03 (s3) (fig. 1d). sulle carote recuperate è stata eseguita un’analisi litostratigrafica e sono stati osservati i caratteri di facies; inoltre è stata effettuata una datazione radiometrica con il metodo del 14c lungo il sondaggio cs. 4.1 sondaggio lazazzera (lz) il sondaggio lazazzera (lz) (fig. 2) è stato perforato ad una distanza di circa 3,5 km dall’attuale linea di costa, ad una quota topografica di 6 m s.l.m., e per una profondità di 52 m raggiungendo la quota di -46 m. sulla carota recuperata è stata effettuata un’analisi stratigrafico-sedimentologica che ha permesso di suddividere in due porzioni la successione sedimentaria attraversata. a partire dalla profondità di 52 m fino a quella di 19 m, si rinviene la porzione inferiore, spessa complessivamente 33 m, dei quali i primi 13 m sono costituiti da 314 fig. 2 colonna stratigrafica ricostruita lungo le carote del sondaggio lz; al lato sono riportati i principali caratteri di facies, le associazioni di facies e i principali ambienti deposizionali. per l’ubicazione vedi fig. 1d. la scala granulometrica utilizzata è quella di wentworth (1922) modificata da bosellini et al. (1989). stratigraphic column and interpretation of facies associations from borehole lz; location in fig. 1d. we used the wentworth (1922) granulometric scale, modified by bosellini et al. (1989). t. pescatore et al. depositi siltosi con intercalazioni di livelli sabbiosi nei primi 10 m, mentre i restanti 20 m sono rappresentati da depositi prevalentemente sabbiosi. i depositi siltosi sono perlopiù massivi e raramente laminati, e spesso si presentano intensamente bioturbati. i depositi sabbiosi presentano nei primi 4 m sottili intercalazioni siltose, possiedono granulometria molto fine ed una laminazione piano-parallela, a luoghi interrotta da bioturbazione. complessivamente questa porzione di successione risulta inoltre ricca di gusci di lamellibranchi e di gasteropodi in frammenti, e contiene resti di ostracodi indeterminabili e radioli di echinidi. il contenuto microfossilifero è invece scarso, rappresentato perlopiù da foraminiferi bentonici fra cui ammonia beccarii, elphidium crispum, textularia agglutinans, valvulineria bradyana, e rari esemplari di hyalinea balthica (sabato et al., in prep.). in erosione sui depositi della porzione inferiore si osserva, a partire dalla profondità di 19 m, la porzione di successione superiore, più grossolana, che si apre con un livello di spessore decimetrico costituito in prevalenza da ciottoli delle dimensioni medie di 3÷4 cm, arrotondati, con abbondante matrice sabbiosa e frammenti di macrofossili. i successivi 4 m, rinvenuti fino alla profondità di circa 15 m, sono costituiti da sabbie medio-fini ricche in frammenti di molluschi indeterminabili, con rare intercalazioni di livelli ciottolosi nella parte alta, e passanti ad un sottilissimo livello siltoso. al di sopra si osservano per uno spessore di circa 1 m sabbie e ghiaie cui seguono 9 m di sabbie, rinvenute fino a circa 6 m di profondità, a granulometria da fine a medio-grossolana, laminate, e con intercalazioni di livelli ghiaiosi spessi qualche centimetro. questi ultimi sono costituiti da ciottoli arrotondati (sferici ed appiattiti) e di dimensioni variabili da 1 cm a 7÷8 cm. all’interno di questi depositi sono stati rinvenuti gusci di bivalvi in frammenti. gli ultimi 6 m della porzione superiore sono rappresentati da sabbie da medie a molto fini con ciottoli sparsi, che verso l’alto passano ad argille siltose grigio-verdastre spesse circa 2,5 m, con rari ciottoli e materiale carbonioso. in base ai caratteri di facies descritti, i depositi siltosi e quelli sabbiosi, che costituiscono la porzione inferiore della successione analizzata, possono essere attribuiti rispettivamente ad ambienti di piattaforma e di transizione alla piattaforma, e ad ambienti di spiaggia sommersa. il livello ghiaioso, posto in corrispondenza della superficie erosiva alla base della porzione superiore della successione è stato interpretato come un deposito residuale (lag). per quanto riguarda invece i restanti depositi appartenenti alla porzione superiore, le sabbie medio-fini con rari livelli ghiaiosi presentano caratteri di facies riferibili ad ambienti di avanspiaggia, i successivi depositi ghiaioso-sabbiosi e sabbioso-siltosi mostrano invece caratteri di facies riferibili ad ambienti di spiaggia sommersa-avanspiaggia, ed infine gli ultimi 6 m rappresentati da sabbie passanti ad argille, sono riferibili ad ambienti continentali, di piana alluvionale e/o di palude. 4.2 sondaggio casa sotto le stelle (cs) il sondaggio casa sotto le stelle (cs) (fig. 3) è stato perforato a circa 2,5 km dall’attuale linea di costa, per una profondità di circa 120 m a partire dalla quota topografica di 4 m s.l.m., e raggiungendo la quota di -116 m. in base ai caratteri litostratigrafici e di facies osservati, la successione sedimentaria attraversata da tale sondaggio può essere suddivisa in due porzioni. la porzione inferiore, spessa circa 76 m, e osservata a partire dalla profondità di 120 m fino a quella di 44 m, è rappresentata da strati argilloso-siltosi e siltoso-argillosi, generalmente massivi ed intensamente bioturbati, ai quali si alternano strati sabbiosi spessi da pochi centimetri fino a qualche metro, fittamente laminati. il contenuto macrofossilifero è rappresentato in prevalenza da frammenti di gusci di bivalvi e gasteropodi marini. in questa porzione di successione si sono rinvenuti numerosi foraminiferi, oltre a nannofossili calcarei; in base alla presenza di emiliania huxleyi lohmann è stato possibile riferire tali depositi ad un’età non più antica del pleistocene medio (sabato et al., in prep.). la porzione superiore della successione poggia in erosione sui depositi sottostanti ed ha uno spessore di circa 44 m. nell’ambito di questa porzione è possibile effettuare una ulteriore suddivisione in due parti: una basale ed una sommitale. la parte basale è spessa circa 7 m, e si rinviene a partire dalla profondità di 44 m fino a quella di circa 37 m. e’ costituita in basso da uno strato a ciottoli con matrice sabbioso-argillosa e con incrostazioni di carbonato di calcio che verso l’alto passa a depositi siltosi con sottilissime intercalazioni argillose di colore grigio-scuro per uno spessore complessivo di 1,5 m; su questi depositi si osserva un’alternanza di strati sabbiosi e strati ghiaiosi con frammenti di gusci di lamellibranchi, per uno spessore complessivo di circa 5,5 m. la parte sommitale, spessa circa 37 m, è costituita, per uno spessore di circa 4 m da depositi sabbiosi a granulometria da molto fine a fine con intercalazioni di livelli ghiaiosi e presenza di gusci interi ed in frammenti di bivalvi e gasteropodi marini; seguono, a partire dalla profondità di circa 33 m, circa 6 m di depositi siltosi con intercalazioni di sottilissimi strati sabbiosi a granulometria molto fine che verso l’alto, fino alla profondità di circa 6 m passano a depositi sabbiosi a granulometria da molto fine a fine e con gusci interi ed in frammenti di bivalvi (tellina sp., spisula subtruncata, chamelea gallina, cerithium sp. e fissidentalium rectum); gli ultimi 6 m circa sono rappresentati da depositi sabbiosi con ciottoli sparsi che verso l’alto passano ad un’alternanza di strati argillosi grigio-verdastri e sabbioso-siltosi con una colorazione giallo-ocra, caratterizzati dalla presenza di gasteropodi terrestri (helicidae) e noduli di carbonato di calcio. su un campione di guscio di un bivalve prelevato ad una profondità di 35 m (campione c6 in fig. 3), è stata effettuata una datazione con il metodo radiometrico del 14c; tale campione ha fornito un’età di 7.562±50 non cal bp (8.510-8350 cal bp; δ13c = -27,6±0.3‰) permettendo di attribuire i primi 35 m della successione attraversata dal sondaggio cs alla parte medio-alta dell’olocene. i caratteri di facies descritti permettono di riferire i depositi argilloso-siltosi e sabbiosi della porzione inferiore della successione ad ambienti di piattaforma e transizione alla piattaforma. la porzione superiore invece mostra nella parte basale, spessa 7÷8 m e formata da silt, argille, sabbie e ghiaie, caratteri di facies riferibili ad ambienti variabili dal continentale (canale fluviale-piana alluvionale-palude) al marino poco profondo (avanspiaggia-retrospiaggia); la parte sommitale della porzione 315stratigrafia dei depositi pleistocenico-olocenici dell’area costiera ... 1 2 3 4 5 6 7 8 9 10 11 12 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 316 fig. 3 colonna stratigrafica ricostruita lungo le carote del sondaggio cs; al lato sono riportati i principali caratteri di facies, le associazioni di facies e i principali ambienti deposizionali. per l’ubicazione vedi fig. 1d. stratigraphic column and interpretation of facies associations from borehole cs; location in fig. 1d. t. pescatore et al. superiore invece è formata da sabbie con livelli ghiaiosi di ambiente di avanspiaggia, passanti verso l’alto a depositi siltosi, sabbiosi, ghiaiosi e argillosi che mostrano un trend shallowing upward, con ambienti variabili dal marino poco profondo (transizione alla piattaformaspiaggia sommersa-avanspiaggia-retrospiaggia) al continentale (piana alluvionale-palude) (fig. 3). 4.3 sondaggio ginosa 01 (s1) i l sondaggio ginosa 01 (s1) (fig. 4) è stato eseguito a circa 2 km dalla linea di costa attuale, ad una quota di 4 m s.l.m. e per una lunghezza di 29,5 m raggiungendo la quota di -25,5 m. è caratterizzato dal basso verso l’alto, per i primi 3,4 m da alternanze di strati molto sottili di sabbie fini e silt argillosi (0,3 m) con laminazioni piano-parallele seguite da un livello di argilla siltosa (0,3 m) e, poi, bruscamente da ghiaie sabbiose. queste presentano uno spessore di 0,28 m, la stratificazione e la tessitura originaria non si è preservata, i ciottoli sono spesso scheggiati, frammentati e/o striati in superficie in seguito alle modalità di esecuzione del sondaggio. sulla superficie di alcuni ciottoli si è osservata matrice sabbiosa cementata. da circa 26 m a circa 20 m di profondità si osservano alternanze di strati sottili e molto sottili di sabbie fini siltose (talora laminate e contenenti rari ciottoli con diametro inferiore al centimetro), e di argille siltose. tra 20 m e 15 m, durante l’esecuzione del sondaggio, si sono perse le informazioni sulla stratificazione e le strutture sedimentarie dei depositi, ma le tessiture sembrano essere simili a quelle del livello precedente. tra 15 m e 7,6 m si rinvengono alternanze di strati sottili e molto sottili di sabbie fini siltose (talora laminate e contenenti ciottoli di diametro inferiore al centimetro) e di argille siltose spesso nerastre a causa della presenza di abbondante sostanza organica. piccole valve di lamellibranchi sono presenti da profondità inferiori a 20 m. da 317 fig. 4 colonne stratigrafiche ricostruite lungo le carote dei sondaggi s1 ed s2; al lato sono riportati i principali caratteri di facies, le associazioni di facies e i principali ambienti deposizionali. per l’ubicazione vedi fig. 1d. stratigraphic columns and interpretation of facies associations from boreholes s1 and s2; for location see fig. 1d. stratigrafia dei depositi pleistocenico-olocenici dell’area costiera ... circa 7,5 m a 3,7 m prevalgono depositi ghiaioso-sabbiosi talora con frammenti di gusci di lamellibranchi. il diametro massimo degli elementi ghiaiosi non supera 10 cm e la loro superficie non presenta tracce di cementi o matrice cementata. da 3,7 m al piano campagna si rinvengono sabbie essenzialmente con granulometria media. i depositi osservati da 29,5 m a circa 26 m non si riescono ad interpretare univocamente e, non avendo dati stratigrafici dei depositi sottostanti, potrebbero rappresentare tanto la base della trasgressione quanto includere il passaggio pleistocene-olocene (verosimilmente la parte alta del livello ghiaioso potrebbe includere un conglomerato basale trasgressivo su ghiaie sabbiose debolmente cementate del pleistocene). da 26 m a 20 m di profondità si sono riconosciute associazioni di facies riferibili ad ambienti di spiaggia sommersa inferiore che verso l’alto (da 15 a 3,7 m di profondità dal piano campagna) passano a un sistema deltizio con associazione di facies di fronte deltizio esterno/prodelta prossimale. queste facies a circa 7,5 m di profondità vengono sostituite da quelle di barra rappresentate da depositi ghiaioso-sabbiosi. nella parte alta del sondaggio, a profondità inferiori di 3,7 m, i depositi sabbiosi (sabbie medie ben selezionate) sono stati attribuiti a facies di avanspiaggia. 4.4 sondaggio ginosa 02 (s2) il sondaggio ginosa 02 (s2) (fig. 4) è stato eseguito a circa 100 m dalla linea di costa attuale, a una quota di 4 m s.l.m. e per una lunghezza di 48 m raggiungendo la quota di -44 m. dal basso verso l’alto è caratterizzato, per i primi 6 m, da alternanze in strati molto sottili di sabbie fini siltose e silt argillosi che passano gradualmente a circa 6 m di alternanze in strati molto sottili di silt argillosi e silt da medio a molto fine con una frazione sabbiosa costituita da muscovite. sempre con passaggio graduale da circa 36 m fino a circa 21 m dal piano campagna si osservano strati sottili e molto sottili di sabbie fini si ltose, alternati a strati molto sottili di silt sabbiosi e subordinatamente di si lt argillosi. seguono, da 21 a 14 m, depositi simili ai precedenti in cui a più altezze si osservano livelli costituiti da sabbie medie, livelli argillosi e talora livelli nerastri ricchi di sostanza organica. da 14 m a 4 m si rinvengono sabbie medio-fini che si alternano a sabbie fini siltose. in queste sabbie sono frequenti valve di lamell ibranchi (intere e in frammenti), ciottoletti e laminazione obliqua, laminazione parallela e strati con gradazione normale. tra 4 e 2,9 m seguono sabbie medie ben selezionate. gli ultimi tre metri sono costituiti da sabbie contaminate da materiale antropico. le associazioni di facies riconosciute dal basso sono: di spiaggia sommersa inferiore tra 48 e 42 m, di transizione alla piattaforma tra 42 e 35 m, di spiaggia sommersa tra 35 e 3÷4 m e, infine, di avanspiaggia tra 3÷4 e 0 m. 4.5 sondaggio ginosa 03 (s3) il sondaggio ginosa 03 (s3) (fig. 5) è stato realizzato a circa 2,8 km dalla linea di costa attuale, ad una quota di circa 3 m s.l.m. e per una lunghezza di 45 m raggiungendo una profondità di -42 m. dal basso verso l’alto si osservano, da 45 a 30,5 m dal piano campagna, alternanze di strati sottili e molto sottili di sabbie molto fini, silt debolmente argilloso e silt argilloso in cui si rinvengono frammenti di gusci di lamellibranchi, radioli di echinidi e livelli ricchi in sostanza organica. seguono, da 30,5 m a 19,7 m, alternanze di strati sottili e molto sottili di sabbie fini e sabbie molto fini più o meno siltose. si distinguono laminazioni pianoparallele, spesso si rinvengono resti di lamellibranchi e, a varie altezze, le sabbie sono cementate per spessori di pochi centimetri. da 19,7 m a 13,2 m si osservano sabbie ghiaiose più o meno cementate e arrossate; sulla superficie dei ciottoli oltre alle patine di ossidi di ferro sono presenti resti di cemento bruno microcristallino 318 fig. 5 colonna stratigrafica ricostruita lungo le carote del sondaggio s3; al lato sono riportati i principali caratteri di facies, le associazioni di facies e i principali ambienti deposizionali. per l’ubicazione vedi fig. 1d. stratigraphic column and interpretation of facies associations from borehole s3; for location see fig. 1d. t. pescatore et al. carbonatico a menisco e microstalattitico. da 13,2 m a 12,7 m si osservano sabbie da grossolane a medio-fini ricche in frammenti indeterminabili di lamellibranchi e gasteropodi e di sostanza organica (si distinguono anche resti vegetali). da 12,7 m a 9,7 m, gradualmente, si passa ad argilla e argilla siltosa di colore grigio scuro con valve di lamell ibranchi (cerastoderma glaucum). seguono circa 0,2 m di torba con gusci di gasteropodi terrestri. da 9,5 m a 6,5 m si rinvengono sabbie medie e fini da ben selezionate a moderatamente selezionate. segue un nuovo livello di circa 0,25 m di torba e da 6,2 m a 0 m si osservano argille siltose più o meno ricche di sostanza organica, con resti di gusci di gasteropodi terrestri e, nella parte medio-alta, noduli calcarei. in questo sondaggio la superficie che limita superiormente le sabbie ghiaiose arrossate e cementate di ambiente di avanspiaggia, rappresenta il limite superiore dei depositi del pleistocene superiore, e pertanto sono stati attribuiti all’olocene solo i primi 13,2 m. al di sopra di questa superficie i depositi compresi tra 13,2 m e 9,5 m rappresentano facies principalmente lagunari che si chiudono con un deposito palustre. tra 9,5 m e 6,5 m, le sabbie medie e fini testimoniano facies di avanspiaggia/retrospiaggia. da 6,5 m a 0 m i depositi argilloso-siltosi con alla base un livello ricco di resti vegetali costituiscono dei depositi palustri che, verso l’alto, presentano caratteri di facies di piana alluvionale. 5. correlazione e stratigrafia dei depositi sepolti lo studio dei caratteri litostratigrafici e di facies dei sondaggi eseguiti, nonché la loro correlazione, hanno permesso di suddividere la successione sedimentaria presente nel sottosuolo della piana di metaponto in tre unità sovrapposte (figg. 6, 7), separate da superfici di discontinuità ben riconoscibili, rappresentate da superfici erosive messe in evidenza anche da bruschi contrasti di facies. l’unità in posizione geometrica inferiore è indicata con il termine di “substrato”; quella intermedia, a geometria cuneiforme in base all’interpretazione proposta in cilumbriello et al. (in stampa), poggia in discontinuità sul substrato, ed è indicata con il termine di “depositi della piana sepolta di metaponto” (psm); la terza unità, la cui porzione sommitale rappresenta l’insieme dei depositi affioranti nella piana costiera metapontina, è riferibile ai “depositi della piana di metaponto” (pm), e poggia in discontinuità sia sul substrato che sui depositi della piana sepolta di metaponto (figg. 6, 7). il substrato è stato perforato per uno spessore variabile fino ad un massimo di circa 76 m (sondaggio cs nelle figg. 3, 6, 7), ed è costituito da sedimenti argilloso-siltosi con intercalazioni sabbiose che verso l’entroterra e verso l’alto passano a depositi sabbiosoconglomeratici (nel sondaggio s3) o sabbiosi (nel sondaggio lz) (figg. 5,7). tali depositi sono riferibili ad ambienti variabili dalla piattaforma all’avanspiaggia. il limite inferiore del substrato non è stato ritrovato, mentre il limite superiore è stato individuato grazie al riconoscimento nei sondaggi s3, lz e cs di una chiara superficie di erosione (se in figg. 2, 3, 6, 7) posta ad una profondità variabile da 13 m (s3) a 44 m (cs). questa superficie è evidenziata nel sondaggio s3 (fig. 5) dalla sovrapposizione di depositi sabbiosi e siltosi di ambiente lagunare dell’unità pm sui depositi sabbiosoghiaiosi di ambiente di avanspiaggia del substrato. procedendo verso mare invece, tale superficie è evi319 fig. 6 sezioni geologiche (ab, cd) effettuate nell’area di studio, realizzate sia utilizzando dati di superficie che di sottosuolo. per l’ubicazione vedi fig. 1d. geological sections (ab, cd) performed in the study area, using surface and core-drillings data; for location see fig. 1d. stratigrafia dei depositi pleistocenico-olocenici dell’area costiera ... 320 fi g. 7 c or re la zi on is tr at ig ra fic he e as so ci az io ni d if ac ie s lu ng o le se zi on ig eo lo gi ch e a ’b e c ’d (v ed if ig . 6 e ca rt a ge ol og ic a al le ga ta ) d ei “d ep os iti d el la p ia na se p ol ta d im et ap on to ” (p sm ) d el p le is to ce ne su p er io re e d ei “d ep os iti d el la p ia na d im et ap on to ” (p m ), d ie tà ol oc en ic a. s tr at ig ra p hi c co rr el at io ns an d fa ci es as so ci at io ns al on g th e a ’b an d c ’d ge ol og ic al se ct io ns (s ee fi g. 6 an d ge ol og ic al m ap )p er fo rm ed in th e up p er p le is to ce ne b ur ie d m et ap on to p la in d ep osi ts (p sm )a nd in th e h ol oc en e m et ap on to p la in d ep os its (p m ). t. pescatore et al. denziata dal deposito residuale (lag) individuato nel sondaggio lz (figg. 2, 7) alla profondità di circa 19 m alla base dell’unità pm, in erosione sui sottostanti depositi di spiaggia sommersa del substrato. nel sondaggio cs infine, la stessa superficie mette a contatto depositi siltoso-sabbiosi di ambiente di transizione alla piattaforma appartenenti al substrato, con depositi di ambiente continentale dell’untà psm (fig. 3, 7). l’età di tale substrato è riferibile al pleistocene medio parte alta, in base alla presenza di emiliania huxley lohmann rinvenuta nelle porzioni argillose della carota del sondaggio cs, e dubitativamente al pleistocene superiore, età cui sono riferibili i depositi sabbioso-conglomeratici dei prismi costieri regressivi più recenti (sabato et al., in prep.). in erosione sul substrato, per mezzo della superficie se si rinviene l’unità dei “depositi della piana sepolta di metaponto” (psm), riscontrata esclusivamente nel sondaggio cs (figg. 3, 6), per uno spessore di circa 7 m. tale unità risulta costituita da depositi sabbiosoghiaiosi con associazioni di facies variabili dal continentale al marino poco profondo. dalla correlazione stratigrafica e da altri dati derivanti dalla stratigrafia di numerosi sondaggi si evince che l’unità psm ha una geometria a cuneo con chiusura verso terra (figg. 6, 7). in base alla posizione stratigrafica ed ai dati raccolti, tale unità può essere riferita al pleistocene superiore (cilumbriello et al., in stampa). infine, l ’unità dei depositi della piana di metaponto (pm) viene a contatto con i sottostanti depositi dell’unità psm per mezzo della superficie st che verso monte intercetta il substrato, ponendo a diretto contatto quest’ultimo con l’unità dei “depositi della piana di metaponto” (pm), (figg. 2, 5, 6, 7). tale superficie si abbassa spostandosi verso mare, tanto che nel sondaggio s3 si rinviene a 13 m di profondità, mentre distalmente supera almeno la profondità di 30 m e 48 m rispettivamente nei sondaggi s1 e s2, in quanto non viene intercettata dagli stessi. i depositi dell’unità pm raggiungono uno spessore di almeno 48 m (sondaggio s2 in figg. 4, 6, 7), e sono rappresentati alla base da sabbie ghiaiose (sondaggi cs e s1) riferibili ad associazioni di facies di avanspiaggia, passanti verso l’alto a sedimenti siltoso-sabbiosi e sabbioso-ghiaiosi, di ambiente variabile da piattaforma a continentale (fig 7). nell’ambito dell’unità pm è possibile riconoscere, quindi, un ciclo completo trasgressivo-regressivo e la superficie st che delimita inferiormente tale unità, rappresenta una superficie di trasgressione (fig. 7). inoltre, la datazione effettuata attraverso il metodo radiometrico 14c (7.562±50 bp) sui depositi del sondaggio cs, permette di attribuire all’olocene i depositi dell’unità pm. 6. conclusioni nel tratto di costa compreso tra la foce del torrente cavone e l’abitato di marina di ginosa, lungo l’area costiera di metaponto, sono stati realizzati un rilevamento geologico di dettaglio, oltre a cinque perforazioni a carotaggio continuo che hanno portato alla realizzazione di una carta geologica dell’area, in scala 1:25.000, corredata da importanti informazioni sui depositi sepolti. nell’ambito dei depositi affioranti è stato possibile individuare due principali unità: “depositi sabbioso-conglomeratici dei prismi costieri regressivi” di età pleistocene superiore, e “depositi della piana di metaponto” di età olocene. all’interno di tali unità sono state effettuate ulteriori suddivisioni, permettendo di delineare un quadro stratigrafico dettagliato e differente da quello attualmente vigente in letteratura. i depositi sabbioso-conglomeratici dei prismi costieri regressivi sono stati distinti in tre unità. le prime due rappresentano dei prismi sedimentari con una morfologia terrazzata, formatisi in seguito ad interazioni fra oscillazioni del livello del mare e sollevamento regionale. nell’area studiata tali depositi sono rappresentati da due unità litostratigrafiche riferibili alle “sabbie e conglomerati di policoro” e alle “sabbie e conglomerati di masseria ricotta“. la terza unità, in erosione su entrambe, è formata da un “prodotto eluviale” discontinuo e di esiguo spessore, rappresentato da sabbie limose di colore rossastro con sottili livelli ghiaiosi. in base a dati di letteratura, queste unità sono riferibili al pleistocene superiore. verso mare ed in posizione meno elevata rispetto ai depositi sabbioso-conglomeratici dei prismi costieri regressivi si rinvengono i “depositi della piana di metaponto”, di età olocenica, all’interno dei quali è stato possibile individuare differenti unità litostratigrafiche rappresentative di altrettanti sistemi deposizionali. a partire dall’entroterra verso la costa sono stati distinti i “depositi continentali” ed i “depositi di transizione”. i depositi continentali sono rappresentati da depositi eluviali, fluviali, lacustri e palustri, quelli di transizione sono costituiti da depositi di spiaggia-duna (attuali ed abbandonati) e da depositi deltizi (attuali ed abbandonati). il quadro stratigrafico è stato ulteriormente arricchito dai risultati ottenuti dallo studio di 5 perforazioni, che hanno raggiunto profondità variabili da 30 m a 120 m. in particolare, la presenza di due importanti superfici di discontinuità ha permesso di distinguere tre unità litostratigrafiche sepolte, di cui sono stati delineati i principali elementi geometrici e sono stati descritti i caratteri di facies. l’unità stratigraficamente più bassa di età pleistocene medio superiore, denominata “substrato” e dello spessore di almeno 76 m, è risultata costituita prevalentemente da depositi siltoso-argillosi riferibili ad ambienti variabili dalla piattaforma al marino poco profondo. in base ai dati stratigrafici ottenuti, le porzioni più grossolane del substrato mostrano lo stesso significato genetico-deposizionale delle unità affioranti rappresentate dai “depositi sabbioso-conglomeratici dei prismi costieri regressivi”, mentre le parti più fini sono correlabili alla formazione nota regionalmente con il nome di argille subappennine. la presenza sul substrato di una netta superficie di erosione, rinvenuta nel sondaggio cs alla profondità di 44 m, permette di identificare una seconda unità litostratigrafica denominata informalmente “depositi della piana sepolta di metaponto”. questa unità è costituita da depositi sabbioso-ghiaiosi non più spessi di 7 m e mostranti associazioni di facies variabili dal continentale al marino poco profondo. l’età di tale unità è riferita al pleistocene superiore. infine sia sui “depositi della piana sepolta di metaponto” che sul “substrato” si rinvengono i “depo321stratigrafia dei depositi pleistocenico-olocenici dell’area costiera ... siti della piana di metaponto” costituenti un cuneo sabbioso-ghiaioso che si chiude verso terra passando da circa 48 m a 0 m. i “depositi della piana di metaponto” (parzialmente affioranti) sono costituiti da sabbie e sabbie ghiaiose, che nell’insieme individuano un sistema di spiaggia progradante, lateralmente associato ad un sistema deltizio che passa distalmente ad un sistema di piattaforma. la datazione radiometrica di un guscio di bivalve prelevato alla profondità di 35 m, e che ha restituito un’età non calibrata di 7.562±50 bp, permette di attribuire i “depositi della piana di metaponto” all’olocene. ringraziamenti gli autori desiderano ringraziare i proff. bellotti dell’università di roma la sapienza, longhitano dell’università della basil icata e tropeano dell’università di bari per gli utili suggerimenti e per la lettura critica del manoscritto. un ringraziammento va al sig. piccenna del consorzio di bonifica di bradano e metaponto per aver cortesemente fornito materiale cartografico e al dott. mallardo dell’anas della basilicata per aver messo a disposizione alcuni dati di profondità. il lavoro è stato eseguito e pubblicato con fondi miur (cofin 2003, responsabile nazionale tullio pescatore), e con fondi di ateneo dell’università di bari (ex 60% 2005-2009, responsabile luisa sabato). bibliografia amato a. (2000) estimating pleistocene tectonic uplift rates in the southeastern apennines (italy) from erosional land surfaces and marine terraces. in: slaymaker o. (ed.) geomorphology, human activity and global environmental change. john wiley & sons, chichester, 67-87. barra d., calderoni g., cipriani m., de la geniere j., fiorillo l., greco g., mariotti lippi m., mori secci m., pescatore t., russo b., senatore m.r., tocco sciarelli g. & thorez j. (1999) depositional history and palaeogeographic reconstruction of sele coastal plain during magna grecia settlement of hera argiva (southern italy). geologica romana, 35, 151-166. bentivenga m., coltorti m., prosser g. & tavarnelli e. (2004) a new interpretation of the terraces in the taranto gulf: the role of extensional faulting. geomorphology, 60, 383-402. boenzi f., cherubini c. & giasi c. (1987) dati e considerazioni sull’evoluzione recente e sui caratteri idrogeologici della piana costiera metapontina compresa tra il f. bradano ed il f. basento (basilicata). geogr. fis. dinam. quat., 10, 34-46. boenzi f., gallicchio s. & vitale g. (2002) caratteri geomorfologici della fascia costiera ionica in basilicata. relazione del progetto esecutivo di prima fase relativo allo studio della costa ionica ed un’ipotesi di intervento per la salvaguardia e difesa del litorale, in relazione agli indirizzi di sviluppo socio-economico della regione basilicata, 28 pp., 1 tav., regione basilicata, dipartimento assetto del territorio, potenza. boenzi f., palmentola g. & valduga a. (1976) caratteri geomorfologici dell’area del foglio “matera”. boll. soc. geol. it., 95, 527-566. boenzi f., radina b., ricchetti g. & valduga a. (1971) note illustrative della carta geologica d’italia alla scala 1:100.000, foglio 201 matera. serv. geol. d’it., 48 pp. bosellini a., mutti e. & ricci lucchi f. (1989) rocce e successioni sedimentarie. utet, 395 pp. brückner h. (1980a) marine terrassen in süditalien. eine quartärmorphologische studie über das küstentiefland von metapont. düsserdolfer geographische schriften, 14, 225 pp. brückner h. (1980b) flussterrassen und flusstäler im küstentiefland von metapont (süditalien) und ihre beziehung zu meeresterrassen. düsserdolfer geographische schriften, 15, 5-32. brückner h. (1982) ausmaß von erosion und akkumulation im verlauf des quartärs in der basilicata (süditalien). zeitschrift geomorphologie n. f., 43, 121-137. capretto g. (2003) i depositi olocenici della piana costiera di metaponto in basilicata (italia meridionale). studi di sedimentologia e mineralogia. tesi di dottorato, università degli studi del sannio, 360 pp. cilumbriello a. (2008) stratigrafia sequenziale dei depositi del pleistocene medio-superiore del metapontino nell’evoluzione del bacino di avanfossa appenninico meridionale. tesi di dottorato, università di bari, 105 pp. cilumbriello a., tropeano m., grippa a., sabato l., gallicchio s., mateu-vicens g., rossi c.a. & spilotro g. (2010) sedimentology and stratigraphic architecture of the metaponto subsurface. in stampa su: mem. descr. carta geol. d’it. cilumbriello a., tropeano m. & sabato l. (2008) the quaternary terraced marine-deposits of the metaponto area (southern italy) in a sequencestratigraphic perspective. geoacta, sp. publ. 1, 27-54. cocco e., cravero e., di geronimo s., mezzadri g., parea g. c., pescatore t., valloni r. & vinci a. (1975) lineamenti geomorfologici e sedimentologici del litorale alto ionico (golfo di taranto). boll. soc. geol. it., 94, 993-1051. cotecchia v., dai pra g. & magri g. (1969) oscillazioni oloceniche e tirreniane del livello del mare nel golfo di taranto, corredate da datazioni col metodo del radiocarbonio. geol. appl. e idrog., 4, 93148, bari. cotecchia v. & magri g. (1967) gli spostamenti delle linee di costa quaternaria del mar ionio fra capo spulico e taranto. geol. appl. e idrog., 2, 1-25. diplomatico g., mirabile l., pennetta m., pescatore t., senatore m.r. & tramutoli m. (1985) morfologia e geologia. in: pescatore t. (ed). geologia e oceanografia del golfo di taranto. prog. fin. oceanografia e fondi marini. rapp.tecnico finale, 90-130. gallicchio s., cilumbriello a., grippa a., sabato l., bertini a., calcagnile l., maiorano p., quarta g. & ricci m. (2008) metaponto coastal plain. in: pre-congress field trip guide “plio-pleistocene stratigraphic and tectonic evolution of the 322 t. pescatore et al. southern italy foredeep: key examples from south apennines front and bradanic trough (basilicata region)”. geosed 2008, bari, 118-121, plate 14.i. massari f. (1988) le facies paraliche: confronto fra depositi costieri e fluviali. giornale di geologia, ser. 3a, 50/1-2, 147-161. migliorini c. (1937) cenno sullo studio e sulla prospezione petrolifera di una zona dell’italia meridionale. 2nd petroleum world congress, paris, 1-11. mostardini f. & pieri m. (1967) note illustrative della carta geologica d’italia, f° 212, montalbano ionico. serv. geol. d’it., 47 pp. neboit r. (1975) plateaux et collines de lucanie orientale et des pouilles; “étude morfologique”. thesis, university of lille, 715 pp. parea g. c. (1986) i terrazzi marini tardo-pleistocenici del fronte della catena appenninica in relazione alla geologia dell’avanfossa adriatica. mem. soc. geol. it., 35, 913-936. pescatore t. & senatore m.r. (2003) le variazioni del livello del mare durante l’olocene e i cambiamenti del paesaggio naturale lungo le fasce costiere. atti lxii convegno internazionale di studi sulla magna grecia, taranto, 209-226. pescatore t., senatore m.r., capretto g. & lerro g. (2001) holocene coastal environments near pompeii before the a.d. 79 eruption of mount vesuvius, italy. quaternary research, 55, 77-85. pieri p., sabato l. & tropeano m. (1994) evoluzione tettonico-sedimentaria della fossa bradanica a sud dell’ofanto nel pleistocene. “guida alle escursioni”. 77° congresso nazionale della società geologica italiana, bari. quaderni della biblioteca provinciale di matera 15, 35-54. pieri p., sabato l. & tropeano m. (1996) significato geodinamico dei caratteri deposizionali e strutturali della fossa bradanica nel pleistocene. mem. soc. geol. it., 51, 501-515. sabato l. & cilumbriello a., con contributi di: bertini a., gallicchio s., la perna r., maiorano p., pieri p., spilotro g., tropeano m. (in prep.) note illustrative della carta geologica d’italia alla scala 1:50.000, foglio 508 “policoro” , 61 pagg. sottoposto per la revisione all’ispra (iii sal.). selli r. (1962) il paleogene nel quadro della geologia dell’italia meridionale. mem. soc. geol. it., 3, 737789. senatore m.r. (1987) caratteri sedimentari e tettonici di un bacino di avanfossa. il golfo di taranto. mem. soc. geol. it., 38, 177-204. senatore m.r., normark w.r., pescatore t. & rossi s. (1988) structural framework of the gulf of taranto (ionian sea). mem. soc. geol. it., 41, 533539. s.g.n. (1992) carta geologica d’italia 1:50.000 guida al rilevamento. quaderni s.g.n., serie iii, 1, 203 pp. s.g.n. (1994) carta geomorfologica d’italia 1:50.000 guida al rilevamento. quaderni s.g.n., serie iii, 4, 42 pp. s.g.n. (1995) carta geologica d’italia 1:50.000 guida all’informatizzazione. quaderni s.g.n., serie iii, 3, 130 pp. s.g.n. (1996) carta geologica d’italia 1:50.000 guida alla rappresentazione cartografica . quaderni s.g.n., serie iii, 2, 97 pp. s.g.n. (1997) carta geologica d’italia 1:50.000 guida al rilevamento. quaderni s.g.n., serie iii, 6, 147 pp. s.g.n. (2003) guida italiana alla classificazione e alla terminologia stratigrafica. quaderni s.g.n., serie iii, 9, 155 pp. shepard t. h. (1948) submarine geology. harper and brothers ltd., vol. di 348 pp., 106, new york. spilotro g. (2004) erosion profile of the blu clay bedrock along the ionian coast of the basilicata region. quaternaria nova, viii, 247-261. tropeano m., sabato l. & pieri p. (2002a) filling and cannibalization of a foredeep: the bradanic trough (southern italy). in: jones s.j. and frostick l.e. (eds). sediment flux to basins: causes, controls and consequences. geological society of london special publication 191, 55-79. tropeano m., sabato l. & pieri p. (2002b) the quaternary “post-turbidite” sedimentation in the south-apennines foredeep (bradanic trough southern italy). boll. soc. geol. it., 121, volume speciale 1, 449-454. valduga a. (1973) fossa bradanica. in: a. desio: «geologia dell’italia», u.t.e.t., torino: 692-695. vezzani l. (1967) i depositi plio-pleistocenici del litorale ionico della lucania. atti acc. gioenia sc. nat. in catania s. vi, 18, 159-180. wentworth c. k. (1922 ) a scale of grade and class terms for clastic sediments. journal geology, 30, 377-392. 323 ms. ricevuto il 18 febbraio 2009 testo definitivo ricevuto il 18 luglio 2009 ms. received: february 18, 2009 final text received: july 18, 2009 stratigrafia dei depositi pleistocenico-olocenici dell’area costiera ... imp. mencucci tthhee ffoogglliiaa rriivveerr aalllluuvviiaall ssyysstteemm ((nnoorrtthheerrnn mmaarrcchhee)) aanndd iittss rreellaattiioonn ttoo tthhee llaattee qquuaatteerrnnaarryy eevvoolluuttiioonn ooff tthhee cceennttrraall aaddrriiaattiicc sshheellff ddaanniieellaa mmeennccuuccccii11,, ppaaoolloo ccoollaannttoonnii11 && oolliivviiaa nneessccii22 1università di urbino, istituto di geodinamica e sedimentologia, italy daniela.mencucci@uniurb.it, colantoni@uniurb.it 2università di urbino, istituto di geologia, italy o.nesci@uniurb.it abstract the late quaternary evolution of the mid-adriatic continental shelf and the river foglia (northern marche) related sediments have been chosen as an example for a tentative correlation between marine and continental sequences. the stratigraphic setting of the late quaternary deposits of the adriatic shelf has been defined by many authors and is characterized by a low system tract, present inside the mid-adriatic depression, followed by the transgressive and highstand system tracts formed by the post-glacial sea-level rise. taking into account data from numerous available boreholes, a longitudinal section of the foglia river alluvial plain has been defined that shows four depositional units. these units, supported by radiocarbon ages, correlate with the recognized marine system tracts (i – ii = lst; iii = tst; iv = hst). riassunto il sistema alluvionale del fiume foglia in relazione con l’evoluzione della piattaforma continentale dell’adriatico centrale. l’evoluzione pleistocenico-olocenica della piattaforma continentale del medio-adriatico e gli eventi deposizionali che caratterizzano la piana alluvionale del fiume foglia (marche settentrionali) sono stati esaminati per tentare di correlare le successioni deposizionali marine e quelle alluvionali. la sequenza regressiva-trasgressiva pliocenico-olocenica che caratterizza la piattaforma continentale, è stata ampiamente illustrata da diversi autori che hanno evidenziato che durante l’ultimo glaciale la linea di riva in adriatico era localizzata circa al traverso di san benedetto – pescara. di conseguenza i depositi marini di mare basso (lst) erano limitati alla depressione meso-adriatica, mentre un’ampia pianura fluvio-palustre occupava l’attuale piattaforma. la successiva trasgressione dovuta all’innalzamento eustatico, depositò sulla piattaforma i materiali che caratterizzano la variazione del livello marino (tst e hst). utilizzando diverse perforazioni eseguite soprattutto dalle amministrazioni pubbliche, è stata costruita una sezione longitudinale dei depositi alluvionali del fiume foglia che ha evidenziato la presenza di almeno quattro unità deposizionali che, alla luce di alcune datazioni radiometriche, si correlano con la sequenza marina. in particolare, l’unità i e ii sono riferibili al low stand system tract (lst), l’unità iii con il transgressive system tract (tst) e la quarta con l’high stand system tract (hst) keywords: alluvial deposits, adriatic continental shelf evolution, correlation between marine and continental sequences, upper pleistocene holocene, foglia river. parole chiave: depositi alluvionali, evoluzione della piattaforma adriatica, correlazione tra sequenze deposizionali, pleistocene olocene, fiume foglia. il quaternario italian journal of quaternary sciences 1166(1), 2003, 35-42 11.. iinnttrroodduuccttiioonn the environmental differences and the depositional aspects always make it difficult to correlate the marine and continental sequences because matching environments, processes and facies that control both modern and ancient environments is never easy. fortunately, the late quaternary recent rise of the sea level allows us to develop models of transgressive sedimentation in shallow seas and to know how this relates to the resultant alluvial deposits and organization. as an example of a tentative correlation we have chosen the mid-adriatic continental shelf and the river foglia valley (northern marche italy) related sediments (fig. 1). this is a starting point for investigating the interplay of sediments supply, tectonics and sea-level changes. our study is based on well data, cores, high resolution seismic profiles and radiocarbon dates. such techniques, based on extensive correlative surfaces, allow the definition of a chronostratygraphic framework according to the facies analysis and to the sequence stratigraphy principles. we consider the influence of tectonics to be negligible (the study area is to be considered stable or slowly uplifting according to elmi et al., 2001/2002, also if gori, 1978, taking into account the shoreface profile for the period 1770-1968, has estimated a sinking of the coast of pesaro ranging between 4.8 and 1.9 mm/yr). therefore the sea-level changes caused by eustatism are the more important factors of the evolution. this assumption facilitates correlation and dating. 22.. mmaarriinnee ssttrraattiiggrraapphhiicc sseettttiinngg ((ffiigg.. 22)) the stratigraphic setting of the late quaternary deposits of the adriatic shelf is well known. in particular, during the last glacial maximum (15-18 ka bp) the conti36 d. mencucci, p. colantoni & o. nesci fig. 1 bedrock setting (by elmi et al., 1983, mod.) andamento del substrato (da elmi et al., 1983, mod.) 37the foglia river alluvial system ... f ig .2 a) s ch em at ic s ec tio n (n ot to s ca le ) fr om th e r iv er p o de lta d ow n to th e d m a (m id a dr ia tic d ep re ss io n) , sh ow in g th e di st rib ut io n of li th of ac ie s in a s eq ue nc e fr am ew or k (s ys te m tr ac ts ). s ez io ne s ch em at ic a (n on in s ca la ) de l d el ta p ad an o al la d m a ( d ep re ss io ne m es o a dr ia tic a) m os tr an te la d is tr ib uz io ne d el le li to fa ci es n el l’a m bi to s eq ue nz ia le ( sy st em tr ac ts ). b) t hi ck ne ss ( in m et er s) o f t he m ud b el t ( h s t ) of f t he f og lia r iv er m ou th ( fr om c ol an to ni e t a l., 1 97 9) . s pe ss or e in m et ri de l d ra pp o pe lit ic o al la rg o de lla fo ce d el fi um e f og lia ( da c ol an to ni e t a l., 1 97 9) . 38 nental shelf edge was located down to the mid-adriatic depression (jabuka trough dma) margin (van straaten, 1965 and 1970; rizzini, 1974; colantoni et al., 1979; colantoni, 1981; ciabatti et al., 1986; colantoni et al., 1992; etc.). therefore, marine deposits of the lowstand system tract (lst) can only have developed inside the depression and at present water depths greater than 110 -130 meters. an alluvial plain, characterized by stiff clays and sands, covered the present shelf. subsequently, the post-glacial rise brought the sea to cover the alluvial plain with transgressive deposits (tst), first represented by beach sands and later by lagoonal sandy and pelitic sediments approximately north off ravenna, where a short stillstand of the sea level and an increase of sediment supply favoured the formation of barrier/lagoon systems (colantoni et al., 1990). these deposits were cut by the ravinament surface and covered by a thin veneer of sand and numerous shell remains. finally, when the sea reached its maximum level (flandrian transgression 7-8 kyr bp), the present highstand sedimentation (hst) took place: sand and pebbles formed the coastal wedges and a long mud belt extended offshore overlying the transgressive deposits that remain largely exposed on the shelf (relict sediments). amorosi et al. (1999) have published the more recent contribution on the glacial eustatic control of continental – shallow marine cyclicity of the facies distribution in the lower po plain. in spite of a different context of subsidence the results achieved can be fairly correlated on the continental shelf. between ravenna and cattolica, in an area affected by rapid subsidence, at least three coastlines have been detected (elmi et al., 2001/2002) referred to the boreal, atlantic and sub-boreal/sub-atlantic according to the chronozones of the northern europe (orombelli & ravazzi, 1996) within the last phases of the holocene transgression. conversely, between cattolica and fano a retreating sea cliff up to 200 m high is cut into the miocene bedrock. here, in a gently uplifting context, the three shorelines are external to the present coastline (elmi et al., 2001/2002) and can only be interpreted according to the morphology of the seafloor and by means of historical data (fig. 3). the last coast evolution was then characterized by active northwestward long-shore drift of coarse sediments and thick bars at the river mouths were formed, thus limiting the marine ingression and favouring the deposition of fine alluvial materials in lagoons and coastal ponds. 33.. aalllluuvviiaall sseeddiimmeennttss ((ffiigg.. 44)) the longitudinal section of the alluvial plain, which has been reconstructed taking into account data from boreholes available from the public administration, shows the substratum setting and the depositional events notwithstanding the difficulties to pick the sequence boundaries. the bedrock beneath the alluvial deposits of the foglia river valley shows a flexion (elmi et al., 1983) similar to those observed in the valleys of conca (elmi et al.,1991) and metauro rivers (elmi et al., 1981). in fact, at about 5 km from the river mouth, its slope increases from about 5 ‰ to 12 ‰ reaching a depth of about 50 60 m below the present sea level near the coastline. it is not clear if this flexion is of erosional or tectonic nature. on the most sloping sector of the bedrock we can observe a first conglomeratic unit of non defined facies (unit i): according to the hypothesis on the flexion origin it should be either of a marine or alluvial nature. this first deposit is truncated by an erosional surface that joins up landwards the less inclined substratum. on this surface lies the most continuous and wide conglomeratic unit of the valley (unit ii) that, from about 3 km far from the present shore, shows sandy and muddy bodies. in addition, due probably to a great marine ingression that reached at least 2.5 km from the present shoreline, this unit is truncated by an erosional surface. from this point a marine sedimentation took place seawards, while the river mouth was progressively closed by a retreating conglomeratic bar that caused the landward deposition of widespread alluvial sandy muds of low-level energy (unit iii). finally, the last phases of the holocene transgression (unit iv) brought the coastline to the present level with minor variations. this is due to first prograding and d. mencucci, p. colantoni & o. nesci fig. 3 holocene shorelines detected in the northern adriatic sea. 1 = boreal; 2 = atlantic; 3 = sub-boreal/sub-atlantic (from elmi et al., 2001/2002, mod.). linee di riva oloceniche individuate nell’adriatico centro-settentrionale. 1 = boreale; 2 = atlantico; 3 = sub-boreale/subatlantico (da elmi et al., 2001/2002, mod.). 39the foglia river alluvial system ... f ig .4 f og lia r iv er s ec tio n. s ez io ne lu ng o la v al le d el fi um e f og lia . 40 later retreating beach deposits. in particular, two surfaces seen in the seismic profiles despite the difficulties of interpretation due to the presence of coarse deposits and organic matter, mark the deposition event (transgressive/regressive?). 44.. ddiissccuussssiioonn waiting for paleontological evidence and confirmation, which are still in progress, fluvial facies are currently described in geometrical and lithological terms and we can try to define a tentative stratigraphic framework of the late quaternary sedimentation based only on the available depositional data on land and off-shore. the low topographic gradient of the adriatic continental shelf together with the low sedimentary input to the sea, caused an important shift of the shoreline and transgression-regression, especially near river mouths. such observation is supported by the presence of marine deposits interfingered with alluvial and paralic sediments. however, interfingered layers are rarely continuous in space and time, making the interpretation in terms of sea-level changes sometimes equivocal (pirazzoli, 1996). moreover, we could not relate floodplain deposits with those of the river channels (ori & cremona, 1988). our reconstruction is therefore very preliminary and tentative. it is based on climatic changes, which we regard as the main cause of eustatic variations, and is calibrated on some radiocarbon ages. as reference, a time scale of the isotope stages (δ 18o) defined by woillard & mook, 1982 and reviewed by dansgaard et al., 1993 has been considered (fig. 4). going from land seawards, the first evolutionary phase that can be observed within the foglia river valley is the deep incision into the pre-quaternary substratum. this incision, which probably began with the demolition of previous sediments, must have occurred during a low-stand sealevel and was followed by the deposition of the units i and ii. a sample of wood (ulmus laevis) that was collected within the depositional unit ii at a depth of 20 m below sea level (point a of fig. 5), shows an uncorrected 14c age of 23,5 ± 1.2 ka bp (calderoni et al., 1997). therefore, the unit ii has been deposited during the phase of climatic deterioration recorded between about 29 and 11 ka bp (isotopic stage 2 = würm pleniglacial). as a consequence, we deduce that the unit i and the incision of the substratum took place during the isotopic stages 3 and 4 (about 73-61-29 ka bp) or during an older one. if this assumption is correct, unit iii should be deposited during the isotopic stage 1 (about 11 ka bp to present = holocene). in fact, a 14c date of 3.9 ka bp has been obtained from a trunk of ulmus laevis collected in a quarry at the depth of about -7 m together with d. mencucci, p. colantoni & o. nesci fig. 5 topography of the study area. contour lines in meters. topografia dell’area di studio. isoipse in metri remains of cardium sp. and mytilus sp. (bedosti, 1985). this finding (point b of fig. 5) confirms the presence of lagoons and coastal ponds in the area that extended as far as about 5 km from the present coastal line in which rivers entered protected by littoral barrier beach (coltorti, 1997). the presence of the barrier is testified by another radio-carbon date obtained from wooden fragments of a fossil trunck (cfr. tilia) collected by drilling at a depth of 10 m (5 m below the present sealevel) in the area of miralfiore-pesaro (point d of fig. 5). the plant, if compared with the present day woodlands of the mediterranean zone, greew along a flood-susciptibile plain (coltorti, 1997) about 3,6-3,8 ka b.p. the erosional surface that lies at the base of the unit could be considered as due to the younger dryas climatic change. the suggestion is enhanced by another 14c date. accordingly, gori (1988) reports another finding of ulmus in a fan deposit at a controversial depth that we assume of 11,5 m from the present ground level (point c of fig. 5), dated 10.09 ± 0.8 ka bp ( = younger dryas). this event “probably is the most significant potential producer of global sea-level fluctuation which occurred since the last glacial maximum” (pirazzoli, 1996). it consisted of acceleration and deceleration during a period of rapid sea-level rise and is expected to have caused sea-level oscillation especially at the river mouth. the effects of such a climate change can hardly be detected on the continental shelf. in the north adriatic sea the cold event of the younger dryas (13-11.7 calendar ka bp; 11-10 14c ka bp) is highlighted by peat layers that mark the base of the post-glacial transgression (correggiari et al., 1996). therefore, the preservation of the barrier/lagoon system (about 8 ka bp) that favoured the paralic deposits and the last phase of the flandrian transgression (colantoni et al., 1990), is to be related to the rapid drowning, which in turn is due to the subsequent increased rate of sealevel rise, connected to the climatic amelioration occurred between 11 and 6 calendar ka bp. the maximum marine ingression is recorded at 6ka bp (climatic optimum) by beach deposits, cliffs and barrier beaches (fig. 5). in the central adriatic sea, off the foglia mouth, the event can be tentatively identified by the marker shown in the high resolution seismic profiles at the base of the depositional unit iv. it is only 2-3 ka bp (sub-atlantic) that the marine ingression leaves signs on the foglia alluvial plain and evidence of ~1.5 m high shorelines. from this phase (roman) a regressive and prograding beach caused the retreat of the coastline approximately to the present position (except for minor recent variations). according to coltorti (1997), the coastal aggradation in the marche region started in the middle ages and increased after the renaissance maintaining a barrierlagoon depositional setting. the presence of lagoons and swamps is documentated by peats sampled 5 m below the present beach in the pesaro area (point e of fig. 5). the obtained date is 590 ± 50 yr bp(with a δ 13c of 26%) (courtesy of g. calderoni, 1994). 55.. ccoonncclluussiioonn notwithstanding the many interpretative difficulties, the study of the river mouth sediments provides an unique opportunity of correlation between continental and marine deposits. the most recent depositional bodies can be interpreted as the result of a complex evolution of alluvial plain, wave dominated shorefaces and barrier/lagoon systems that interfinger their products with the transgressive and regressive marine deposits. the numerous surfaces that mark the details of the depositional pulses are not easily correlated on the continental shelf. in fact, many surfaces form downlapping features that end laterally. nevertheless, the limit of sequence that denotes the last phases of the flandrian transgression is very clear. in addition, it is easy to recognize and divide both the lowstand transgressive and the highstand system tracts (lst, tst and hst), while the ravinament surface (rs) and the maximum flooding surface (mfs) are coincident (cfr. correggiari et al., 1996, figg. 3 e 4). from a general point of view, the alluvial units i and ii, that formed the greatest conglomeratic alluvial plain, correspond and laterally blend in stiff clays and sands of the lst of the shelf. unit iii comes into the tst and the unit iv into the hst. 66.. rreeffeerreenncceess amorosi a., colalongo m. l., fusco f. (1999) glacioeustatic control of continental-shallow marine cyclicity from late quaternary deposits of the southeastern po plain, northern italy. quaternary research, 5522, 1-13. bedosti b. (1985) guida alla visita del museo scientifico “l. guidi”. suppl. boll. sism., 3-19. calderoni g., elmi c., nesci o., rondoni p. (1997) datazione di eventi deposizionali e delle linee di riva tardo-pleistocenico-oloceniche nella piana costiera del fiume foglia (marche settentrionali). convegno fist-geoitalia, bellaria, 5-9 ottobre. ciabatti m., curzi p., ricci lucchi f. (1986) sedimentazione quaternaria nell ’adriatico centrale. atti riunione gruppo sedimentologico cnr, ancona 5-7 giugno, 125-139. colantoni p., gallignani p., lenaz r. (1979) late pleistocene and holocene evolution of the north adriatic continental shelf (italy). marine geology, 3333, 41-50, amsterdam. colantoni p. (1981) le recenti acquisizioni sulla geologia della piattaforma continentale ital iana. convegno p. f. oceanografia e fondi marini, 207217, roma. colantoni p., preti m., villani b. (1990) sistema deposizionale e linea di riva olocenica sommersi in adriatico al largo di ravenna. giornale di geologia, 5522, 1-18. colantoni p., asioli a., borsetti a. m., capotondi l., vergnaud-grazzini c. (1992) subsidenza tardopleistocenica ed olocenica nel medio adriatico evidenziata dalla geofisica e da ricostruzioni paleoambientali. mem. soc. geol. it., 4422, 209-220. coltorti m. (1997) human impact in the holocene fluvial and coastal evolution of the marche region, central italy. catena, 3300, 311-335. correggiari a., roveri m., trincardi f. (1996) late pleistocene and holocene evolution of the north 41the foglia river alluvial system ... adriatic sea. il quaternario, 99, 697-704. dansgaard w., johnsen s. j., clausen h. b., dahljensen d., gundestrup n. s., hammer c. u., hvidberg c. s., steffensen j. p., sveinbjornsdottir a. e., jouzel j., bond g. (1993) evidencies for general instability of past climate from a 250-kyr icecore record. nature, 336644, 218-220. elmi c., francavilla f. & merelli p. (1981) ricerche geologiche e idrogeologiche nella bassa valle del f. metauro (marche settentrionali). acta naturalia de l’ateneo parmense, 1177, 53-72. elmi c., didero m., francavilla f., gori u., orazi u. (1983) geologia e idrogeologia della bassa valle del fiume foglia (marche settentrionali). acta naturalia de l’ateneo parmense, 1199, 117-136. elmi c., nesci o. & tentoni l. (1991) la piana del torrente conca e le pianure minori nord-marchigiane: forme, depositi ed evoluzione. geogr. fis. dinam. quat., 1144, 113-117. elmi c., colantoni p., gabbianell i g., nesci o. (2001/2002) holocene shorelines along the central adriatic coast (italy). geoacta, 11, 31-39. gori u. (1978) le variazioni della linea di costa del litorale pesarese ed alcune considerazioni sulla subsidenza della piana alluvionale del fiume foglia. cam. comm. ind. art. agr., pesaro, 1-43. gori u. (1988) contributo alla conoscenza della sedimentazione delle alluvioni quaternarie del fiume foglia (marche). geogr. fis. dinam. quat., 1111, 121-122. ori g. g., cremona m. (1988) facies e geometrie deposizionali dei sedimenti fluviali. giornale di geologia, 5500, 39-67. orombelli g., ravazzi c. (1996) the late glacial and early holocene: chronology and paleoclimate. il quaternario, 99 (2), 439-444. pirazzoli p. a. (1996) sea-level changes – the last 20000 years. wiley, 1-211. rizzini a., (1974) holocene sedimentary cycle and heavy mineral distribution, romagna-marche coastal plain, italy. sedimentary geology, 1111, 17-37, amsterdam. straaten l. m. j. u. van. (1965) sedimentation in the north-western part of the adriatic sea. a symposium. collston pap., 1177, 143-162. straaten l. m. j. u. van. (1970) holocene and late pleistocene sedimentation in the adriatic sea. geol. rundsch., 6600, 106-131. woillard g. m., mook w. g. (1982) carbon 14 dates at grand pile. science, 221155, 159-161. 42 ms. ricevuto il 16 ottobre 2002 testo definitivo ricevuto il 20 maggio 2003 ms. received: october 16, 2002 final text received: may 20, 2003 d. mencucci, p. colantoni & o. nesci imp.bianca-caputo aannaalliissii mmoorrffootteettttoonniiccaa eedd eevvoolluuzziioonnee qquuaatteerrnnaarriiaa ddeellllaa vvaall dd’’aaggrrii,, aappppeennnniinnoo mmeerriiddiioonnaallee mmaarrcceelllloo bbiiaannccaa && rriiccccaarrddoo ccaappuuttoo di.s.g.g., università della basilicata, campus macchia romana, 85100, potenza, italia riassunto sulla base di una dettagliata indagine morfologica dei terrazzi fluviali e marini che caratterizzano la val d'agri (italia meridionale), è stato possibile ricostruire l'evoluzione morfotettonica quaternaria di questo settore dell'appennino meridionale. i risultati ottenuti permettono di suddividere la valle in tre settori a diversa evoluzione morfotettonica, separati da due evidenti soglie morfostrutturali coincidenti con altrettante importanti strutture tettoniche. il settore più occidentale, rappresentato dall’alta val d’agri, è compreso tra la sorgente ed il sovrascorrimento dell’armento. l’evoluzione morfotettonica e sedimentaria tardo-quaternaria di questo tratto vallivo è stata principalmente controllata dalla persistenza, durante il pleistocene, di una soglia rappresentata da un’estesa anticlinale con asse nno-sse, strutturalmente associata al sovrascorrimento dell’armento e responsabile della formazione del 'paleolago' del pertusillo. la presenza, a quote prossime al corso attuale dell’agri, di due ordini simmetrici di terrazzi alluvionali (il più recente dei quali è attualmente sommerso dal lago artificiale del pertusillo), attribuibili al pleistocene superiore-olocene, suggerisce altrettante fasi discrete di sollevamento tettonico che potrebbero essere il risultato dell’attività recente di una o più faglie bordiere dell’alta val d’agri. la media val d’agri è invece impostata sulle successioni clastiche marine e continentali plio-pleistoceniche del bacino di sant’arcangelo ed è confinata tra il sovrascorrimento dell’armento e un’altra soglia, anch’essa di origine tettonica, rappresentata dalla faglia di scorciabuoi. la proiezione longitudinale dei quattro ordini di terrazzi fluviali medio-suprapleistocenici rilevati lungo la riva destra dell’agri, nel settore dell’abitato di sant’arcangelo, evidenzia che questo versante è stato interessato, nel tardo quaternario, da un processo di sollevamento e di piegamento antiforme, che suggerisce un’attività recente della faglia di scorciabuoi o di un’eventuale struttura contrazionale sepolta. infine, la bassa val d’agri, compresa tra la faglia di scorciabuoi e la costa ionica, è caratterizzata dalla presenza di terrazzi sia fluviali che marini. la buona correlazione fisica tra i terrazzi marini, sviluppati trasversalmente alla foce dell’agri, e i terrazzi fluviali presenti lungo il tratto più basso del fiume, conferma l’influenza predominante dell’eustatismo nell’evoluzione morfologica di questa porzione della valle. l’analisi morfotettonica della distribuzione dei terrazzi marini del pleistocene medio-superiore ha evidenziato che il settore costiero della foce dell’agri è stato interessato da un sollevamento tettonico quaternario non uniforme nello spazio e nel tempo, caratterizzato da tassi compresi tra 0,03 mm/a e 2,76 mm/a. abstract the agri river extends for about 100 km from the axial zone of the southern apennines to the ionian coast of the basilicata region, southern italy, flowing with a mean e-w direction and crossing both the internal and external geological domains of the ne-verging fold-and-thrust apennines belt. the agri valley develops along one of the most tectonically active regions of southern italy, which has been struck by recurrent and large seismic events in historical times, such as the 1857 basilicata earthquakes. based on the great sensitivity of the alluvial rivers to the variations in topographical gradient, a morphotectonic analysis has been carried out on the quaternary alluvial, erosional and marine terraces occurring along and at the mouth of the agri river. the preliminary results allow us to divide the agri valley into three reaches (sectors a, b and c), bounded by two major tectonic structures, the armento thrust and the scorciabuoi fault and characterized by different deformation and morphogenic processes. the orders of terraced surfaces have been labelled with roman numbers, starting from the youngest and lowest terrace (i) to the older ones. except terrace i that has been observed throughout most of the valley, all other terraces are followed by a letter, indicating the sector of the agri valley where they occur (a, b or c) if of fluvial origin, or by the letter "m" when they represent marine terraces. the quaternary morphological and sedimentary evolution of high agri valley (sector a) has been controlled mainly by the persistence, until present time, of an important threshold occurring at the nucleus of the anticline associated to the e-verging armento thrust. during the middle-late pleistocene, the beginning of the entrenchment of the threshold caused the progressive outpouring of the ancient pertusillo lake, previously generated by the growing anticline, with the formation of the wide terrace (iii-a) representing the top of the lacustrine deposits. on the other hand, the alluvial terraces i and ii-a are possibly related to as many, probably fault-related, uplifting phases which occurred in late pleistocene-holocene time. the middle agri valley (sector b), crossing the middle pliocene-middle pleistocene s. arcangelo basin, is eastward bounded by the nwse-trending strike-slip scorciabuoi fault. four orders of asymmetrical middle pleistocene-holocene alluvial terraces, showing a clear antiform warping, have been recognized in this sector. the deformed terraces, together with the shifting of the entrenching channel toward the opposite northern bank of the river, suggest that the uplift and the warping processes are likely to be associated to a blind thrust or, alternatively, to the tectonic activity of the scorciabuoi fault. the occurrence of a seismogenic fault in the central part of the agri valley would account for the strong damages (i=x mcs) undergone by the villages of aliano and alianello during the 1857 basilicata earthquake (m=6.5). finally, the low agri valley (sector c) is characterized by the occurrence of both alluvial and marine terraces showing a good morphological correlation. the morphotectonic analysis of the marine terraced sequence, considered as the result of the interaction between tectonic uplift and middle-late quaternary eustatic changes, pointed out a non-uniform tectonic uplifting rate of the coastal area, the magnitude of which clearly decreases toward the front of the apennines orogenic belt. moreover, the vertical distribution of the palaeo-shorelines of the marine terraces allowed us to estimate uplift rates ranging from about 0.2 mm/a to more than 2.5 mm/a, which are more typical of fault activity rather than regional uplift. parole chiave: tettonica quaternaria; val d’agri; terrazzi fluviali e marini; tassi di sollevamento. keywords: : quaternary tectonics; agri valley; fluvial and marine terraces; uplift rates. il quaternario italian journal of quaternary sciences 1166(2), 2003, 159-170 iinnttrroodduuzziioonnee il fiume agri scorre in direzione circa e-o per oltre 100 km lungo il settore meridionale della basilicata, dalla zona assiale dell’appennino lucano fino alla costa del mar ionio, seguendo una direzione diagonale rispetto all’andamento della catena (fig. 1b). la val d’agri è quindi impostata su diversi domini geologici, passando dalle unità geologico-strutturali interne a quelle esterne dell’orogene appenninico fino ad attraversare, nel suo tratto finale, i depositi clastici dell’avanfossa bradanica (fig. 1b). questo settore di catena-avanfossa è stato caratterizzato da una complessa storia deformativa cominciata nel miocene inferiore, con la messa in posto 160 m. bianca & r. caputo marine è stato eseguito mediante l’analisi aerofotogrammetrica di strereocoppie a scala 1:33.000 dell’igm e verificato successivamente con dettagliate e specifiche indagini di terreno. i dati ottenuti sono stati così cartografati sulla base topografica a scala 1:25.000 dell’igm. la scarsa continuità laterale dei terrazzi fluviali, assieme alla mancanza di datazioni assolute, non ha consentito una correlazione univoca tra i diversi ordini terrazzati lungo l’intero corso dell’agri. tuttavia, la distribuzione areale dei dati raccolti mostra una continuità sufficiente per correlare i diversi ordini terrazzati all’interno dei tratti alto (settore a), mediano (settore b) e basso (settore c) della val d’agri (fig. 1). questi tre settori, separati da due importanti soglie coincidenti con altrettante strutture neotettoniche (sovrascorrimento dell’armento e faglia di scorciabuoi), si differenziano in base al diverso ruolo che i principali fattori morfogenici, ovvero i processi tettonici, climatici ed eustatici, hanno giocato nell’evoluzione geomorfologica di questa valle. l’influenza di questi diversi fattori sull’evoluzione della val d’agri dipende fortemente dalla scala cronologica in cui vengono analizzati. infatti, considerando che l’intervallo temporale analizzato abbraccia quasi l’intero quaternario, è possibile affermare che il processo continuo di sollevamento fig. 1 a: localizzazione regionale dell’area attraversata dalla val d’agri. b: schema geologico-strutturale del settore lucano dell’appennino meridionale. legenda: 1 = depositi clastici dell’avanfossa bradanica (pliocene-quaternario); 2 = depositi di flysch (miocene); 3 = unità lagonegresi (triassico inferiore-miocene medio); 4 = unità carbonatiche della piattaforma apula (mesozoicocenozoico); 5 = unità carbonatiche della piattaforma campano-lucana (mesozoico-cenozoico); 6 = sovrascorrimenti; 7 = faglie normali; 8 = faglie trascorrenti. c: carta morfotettonica schematica della val d’agri, in cui sono rappresentate le superfici terrazzate fluviali e marine (aree in grigio) con i rispettivi bordi interni e le due principali strutture tettoniche che segmentano la valle e che permettono di distinguere tre settori. a: southern italy map and location of the investigated area. b: geological-structural sketch of the lucanian apennines. legend: 1 = clastic deposits of the bradanic foredeep (pliocene-quaternary); 2 = flysch deposits (miocene); 3 = lagonegro units (lower triassicmiddle miocene); 4 = carbonates of the apulian platform (mesozoic-cenozoic); 5 = carbonates of the campania-lucania platform (mesozoic-cenozoic); 6 = thrust faults; 7 = normal faults; 8 = strike-slip faults. c: morphotectonic sketch of the agri valley, showing the fluvial and marine terraces (grey-coloured areas) with their inner edges and the main tectonic structures cutting the valley allowing the distinction of three sectors. dell’edificio a falde e-vergenti dell’appennino, e seguita da fasi tettoniche tardo-orogeniche testimoniate da diversi sistemi strutturali sia distensivi che trascorrenti. alcune di queste strutture sono ancora attive, come testimonia la forte sismicità storica di questa regione, colpita da numerosi eventi sismici ad alta energia, come il terremoto della basilicata del 1857. questo lavoro, che rappresenta un tentativo di analisi morfotettonica della val d’agri, è stato suddiviso in due fasi: nella prima fase sono state individuate e interpretate le principali morfostrutture fluviali e marine presenti rispettivamente lungo il corso del fiume agri e lungo il tratto costiero adiacente alla foce; nella seconda fase, invece, questi elementi morfologici sono stati utilizzati come elementi diagnostici degli eventi deformativi quaternari che hanno interessato questo settore della basilicata meridionale. a questo scopo, sono state applicate metodologie d'indagine basate prevalentemente sulla sensibilità dei fiumi alle variazioni del gradiente topografico, e sulla distribuzione dei terrazzi fluviali e marini presenti rispettivamente lungo il corso d’acqua principale e in corrispondenza della foce (schumm et al., 2000; burbank & anderson, 2001). il rilevamento delle superfici terrazzate fluviali e tettonico regionale, sebbene caratterizzato da tassi sicuramente variabili nel tempo, può essere considerato il fattore morfogenico preponderante nell’evoluzione della valle, rispetto ai processi ciclici come le variazioni climatiche ed eustatiche. a questo proposito, è importante sottolineare che un processo ciclico può lasciare una traccia morfologica in un sistema fluviale soltanto se il suo periodo di oscillazione è superiore al tempo di risposta del sistema fluviale stesso, che è generalmente nell’ordine di 103 anni (vandenberghe, 2002). di conseguenza, le variazioni climatiche comprese tra quelle stagionali e quelle millenarie non possono lasciare una traccia morfologica evidente lungo una valle fluviale. un ruolo morfogenico ben diverso hanno invece avuto le principali oscillazioni eustatiche quaternarie, in particolare lungo quei tratti del fiume agri che si trovavano in prossimità della paleolinea di costa. l’impatto morfogenico importante delle oscillazioni eustatiche è legato principalmente al loro lungo periodo di ciclicità (104-105 anni) e alla loro notevole escursione verticale (120-150 m tra un picco glaciale e un picco interglaciale). i diversi ordini di superfici fluviali, marine e continentali sono stati indicati mediante cifre romane, crescenti dagli ordini più bassi e recenti a quelli più elevati 161analisi morfotettonica ... e antichi. ognuno dei settori è ovviamente caratterizzato da una numerazione dei terrazzi fluviali autonoma, evidenziata dalla lettera del settore (a, b o c) che segue il numero romano, mentre i terrazzi d'origine marina sono indicati dalla lettera "m". a questa classificazione fa eccezione la superficie alluvionale più recente (terrazzo i), che è presente con una buona continuità laterale lungo l’intero corso dell’agri. e' da notare che lungo alcuni tratti tale superficie, che rappresenta sempre il tetto dei depositi fluviali più recenti, costituisce l’attuale letto di piena del fiume, mentre lungo altri tratti la stessa superficie appare sospesa rispetto al canale attuale, formando così il terrazzo fluviale più giovane tra quelli rilevati in questo studio. nelle sezioni successive del presente articolo, saranno descritti e discussi separatamente, da un punto di vista dell'evoluzione morfologica e fluviale, i tre settori in cui è stata suddivisa la valle del fiume agri. settore a: alta val d’agri l’alta val d’agri (fig. 2) attraversa il settore interno dell’appennino lucano che è costituito da un sistema a pieghe e sovrascorrimenti (fold-and-thrust system) ne-vergente strutturatosi tra il miocene inferiore fig. 2 carta morfotettonica dell’alta val d’agri (settore a). legenda: 1 = substrato delle superfici terrazzate e dei terrazzi fluviali quaternari; 2 = terrazzo fluviale i; 3 = terrazzo fluviale ii-a; 4 = terrazzo fluviale iii-a; 5 = superficie terrazzata iv-a; 6 = tratto fluviale inforrato; 7 = faglia diretta; 8 = sovrascorrimento; 9 = faglia trascorrente; 10 = traccia assiale di anticlinale; 11 = traccia assiale di sinclinale; 12 = bordo interno di terrazzo. morphotectonic map of the high agri valley (sector a). legend: 1 = substratum of the quaternary terraced surfaces and fluvial terraces; 2 = fluvial terrace i; 3 = fluvial terrace ii-a; 4 = fluvial terrace iii-a; 5 = terraced surface iv-a; 6 = fluvial canyon; 7 = normal fault; 8 = thrust fault; 9 = strike-slip fault; 10 = axial trace of anticline; 11 = axial trace of syncline; 12 = inner edge of terrace. (d’argenio et al., 1973) ed il pleistocene inferiore (carbone et al., 1991; cinque et al., 1993). i terreni coinvolti nella deformazione orogenica, prevalentemente mesozoici, appartengono sia alle unità lagonegresi (scandone, 1967), che alle unità di piattaforma carbonatica (scandone, 1971). nel settore orientale dell’alta val d’agri, il substrato mesozoico è ricoperto dai depositi flyschoidi miocenici delle formazioni di gorgoglione e albidona. questo settore della val d’agri è delimitato verso est da una soglia morfostrutturale rappresentata da una serie di rilievi localizzati tra l’abitato di montemurro e il torrente armento (fig. 2) e litologicamente costituiti dai terreni silicoclastici della formazione di gorgoglione. quest’area di soglia coincide con la zona assiale di una anticlinale con asse orientato nno-sse strutturalmente associata al sovrascorrimento dell’armento. questa struttura fa parte di una serie di sovrascorrimenti principali che caratterizzano il quadro strutturale dell’alta val d’agri e che mostrano una geometria generalmente arcuata con convessità verso est e con una direzione media n150°, coincidente con l’andamento dell’intera dorsale appenninica. il profilo longitudinale del canale attuale del fiume agri, infatti, conferma la presenza di una netta variazione di pendenza (knick-point) in corrispondenza della zona assiale di questa anticlinale (fig. 3), suggerendo che il processo di erosione regressiva, che dovrebbe portare il fiume a raggiungere il profilo di equilibrio ideale, è tuttora in corso. le principali strutture di tipo contrazionale sono dissecate ad alto angolo da diversi sistemi di faglie estensionali e trascorrenti, riferibili alle fasi tettoniche tardo-orogene del pleistocene. il più importante tra questi sistemi strutturali borda il bacino intramontano nel quale si sviluppa l’alta val d’agri ed è formato da faglie a direzione media n 120° (fig. 2), caratterizzate da una cinematica trascorrente sinistra durante il pleistocene inferiore e riattivate come faglie dirette durante il pleistocene medio (giano et al., 2000). il riempimento sedimentario del bacino è costituito da una successione clastica quaternaria, denominata 'complesso val d’agri' (di niro et al., 1992), caratterizzata da argille e limi lacustri alla base, che passano verso l’alto a depositi marcatamente fluviali, per terminare al tetto con uno spessore di depositi caotici di conoide alluvionale. la morfologia dell’alta val d’agri è alquanto differenziata: infatti, mentre lungo il tratto più elevato del suo corso il fiume agri scorre all’interno di un fondo vallivo piatto e alluvionato, a cominciare dagli abitati di villa d’agri e tramutola i versanti della valle cominciano ad essere reincisi e terrazzati dal fiume e dai suoi affluenti. sui versanti del settore centro-orientale dell’alta val d’agri sono stati rilevati quattro ordini di superfici terrazzate (i, ii-a, iii-a e iv-a), sia erosionali che deposizionali, impostate sia sul substrato pre-quaternario che sul tetto dei depositi clastici quaternari del complesso val d’agri (fig. 2). alcuni relitti della superficie più antica (terrazzo iva), costituita da una spianata d’erosione impostata prevalentemente sui depositi terrigeni miocenici del flysch di gorgoglione, sono ubicati su ambedue i versanti vallivi tra montemurro e il torrente armento, ad una quota compresa tra 780 e 850 m circa. questa superficie è stata attribuita al pleistocene medio (di niro et al., 1992) sulla base di una correlazione fisica con una superficie sviluppata a quote analoghe al tetto delle 'sabbie e conglomerati di serra corneta', affioranti a est dell’armento, nel bacino di sant’arcangelo, e attribuite al pleistocene medio (pieri et al., 1994; casciello et al., 2000). se questa interpretazione è corretta, i l pleistocene medio rappresenta, probabilmente nella sua parte inferiore, il limite cronologico inferiore dell’intera successione terrazzata dell’alta val d’agri. il terrazzo iii-a è rappresentato da una superficie ampia e piuttosto continua, riconoscibile sui due versanti dell’agri compresi tra villa d’agri e montemurro ed estesa nella fascia altimetrica compresa tra 560 m e 700 m circa. probabilmente, lungo il versante sinistro della valle la superficie di ordine iii-a è presente anche a quote più elevate, ricoperta da alcuni conoidi alluvionali. la superficie di ordine iii-a è dissecata trasversalmente dai numerosi torrenti che affluiscono nell’asta fluviale principale e che incidono profondamente i sedimenti fluvio-lacustri del complesso val d’agri. una caratteristica peculiare di questo ordine terrazzato è la sua notevole ampiezza, intesa come distanza tra bordo interno e bordo esterno, che varia da un minimo di 3 km circa fino a raggiungere un massimo di 5 km circa sul versante destro dell’agri, ad est di grumento nova. la superficie terrazzata è impostata quasi interamente sul top dei depositi fluvio-lacustri quaternari del complesso val d’agri, per cui la sua età risulta compresa tra l’età del terrazzo iv-a (pleistocene medio basale) e l’età del tetto del complesso val d’agri (pleistocene superiore). la successione terrazzata dell’alta val d’agri termina con due ordini di terrazzi fluviali (terrazzi ii-a e i), anch’essi impostati sui depositi quaternari della valle e rappresentati da due superfici molto meno ampie del terrazzo iii-a, che si estendono tra grumento nova e spinoso sia parallelamente al corso dell’agri, sia lungo alcuni tributari di destra, come il torrente maglia (fig. 2). il bordo interno del terrazzo ii-a si trova ad una quota di circa 550 m, mentre il bordo esterno viene stagionalmente sommerso dalle acque del lago artificiale del pertusillo, il cui livello è stato fissato a circa 530 m sulla base cartografica a scala 1:50.000 utilizzata per questo lavoro. poiché l’analisi aereofotogrammetrica è stata eseguita su stereocoppie scattate in un periodo precedente alla costruzione della diga del pertusillo, è stato possibile individuare anche l’ordine terrazzato più recente (terrazzo i), di solito completamente sommerso dalle acque dell’invaso e quindi non cartografabile attualmente, delimitato a monte da un bordo interno localizzato ad una quota media di circa 520 m. la mancanza di riferimenti cronologici assoluti all’interno della successione di terrazzi fluviali del settore a della val d’agri, non consente di elaborare una precisa interpretazione quantitativa dell’evoluzione morfotettonica di questo settore. tuttavia, la distribuzione e le caratteristiche morfologiche delle superfici terrazzate, assieme all’analisi stratigrafica dei depositi clastici quaternari che riempiono il bacino dell’alta val d’agri, indicano che questo settore ha subito un’evoluzione morfologica e sedimentaria controllata prevalentemente dallo sviluppo della soglia in corrispondenza dell’anticlinale con asse nno-sse associata al sovrascorrimento dell’armento. anche un possibile effetto di morfoselezione ha certamente influito sull'evoluzione di questo tratto del fiume, dove si può tuttora notare (fig. 3) l’esistenza di un knick-point lungo il profilo del fondo valle. e’ 162 m. bianca & r. caputo 163 comunque evidente che, poiché la forra formatasi attraverso l’anticlinale dell’armento incide un’unica litologia (flysch di gorgoglione), quest’ultimo effetto non può da solo giustificare la presenza di terrazzi fluviali. l’attribuzione della superficie di spianamento di ordine iv-a al pleistocene medio (di niro et al., 1992) pone un limite ante quem all’intera successione terrazzata di questo settore. nell’intervallo di pleistocene medio compreso tra la formazione della superficie di ordine iv-a e il terrazzo di ordine iii-a, si è verificato l’episodio di parziale riempimento del settore dell'alta val d'agri che ha portato alla deposizione delle argille lacustri basali del complesso val d’agri (di niro et al., 1992). e’ possibile ipotizzare che questo episodio deposizionale sia collegato con una fase di forte innalzamento relativo della soglia, durante la quale il fiume agri fig. 3 proiezione longitudinale dei bordi interni dei terrazzi fluviali e marini presenti rispettivamente sui versanti della val d’agri e lungo il tratto costiero ionico adiacente alla foce del fiume. sono inoltre schematizzati i principali elementi strutturali che intersecano la valle. si notino la brusca variazione di pendenza (knick-point) lungo il profilo del terrazzo fluviale di ordine i in corrispondenza dell’anticlinale dell’armento (settore a), i terrazzi fluviali deformati in riva destra della media val d’agri (settore b) e la corrispondenza morfologica tra terrazzi fluviali e marini dello stesso ordine nell’ultimo tratto fluviale (settore c). legenda: 1 = asse di anticlinale; 2 = faglia; 3 = traccia longitudinale di bordo interno di terrazzo fluviale; 4 = traccia di bordo interno di terrazzo marino, e relativo ordine. longitudinal projection of the inner edges of the fluvial and marine terraces occurring on the flanks of the agri valley and along the ionian coastal reach of the river mouth. main structural features are also sketched. it is worthy to note the knick-point in the profile of the fluvial terrace i, corresponding to the armento anticline (sector a), the warped fluvial terraces along the right flank of the middle agri valley (sector b) and the morphological continuity of the fluvial and marine terraces of the same order along the last fluvial reach (sector c). legend: 1 = axis of anticline; 2 = fault; 3 = longitudinal trace of the inner edge of fluvial terrace; 4 = trace of inner edge of marine terrace and relative order. analisi morfotettonica ... continua comunque ad incidere un profondo canyon perpendicolarmente alla zona di cerniera dell’anticlinale, ma con una velocità inferiore a quella del sollevamento tettonico della soglia. si è così formato l'attuale profilo a geometria articolata. alla fine del pleistocene superiore, il tasso di sollevamento relativo della soglia diminuisce fino ad essere superato dal tasso di incisione verticale dell’agri, con il conseguente svuotamento graduale del 'paleolago' del pertusillo. il risultato morfologico di questo processo è rappresentato dall’ampia superficie del terrazzo iii-a impostata sul tetto del complesso val d’agri. la continuità del fenomeno, testimoniata dalla particolare ampiezza e regolarità morfologica della superficie del terrazzo iii-a, conferma l’avvenuto arresto del processo di sollevamento tettonico dell’area di soglia e la persistenza di un 'effetto filtro' generato dalla soglia stessa che ha annullato l'influenza delle oscillazioni eustatiche sull’evoluzione morfologica dei versanti sia del lago che del canyon in incisione. in questa ipotesi di modello morfo-evolutivo indipendente dalle oscillazioni eustatiche, i due ordini di terrazzi fluviali più recenti ii-a e i possono essere interpretati come il risultato di altrettante fasi di sollevamento locale che sono state tentativamente attribuite all'attività recente di una o più strutture bordiere dell'alta val d'agri (fig. 2; burrato, 1995). inoltre, anche le variazioni climatiche potrebbero aver giocato un ruolo nella formazione dei terrazzi fluviali. non conoscendo, però, l’età precisa di questi ultimi, non è possibile quantificare il contributo climatico nell’intero processo evolutivo. settore b: media val d’agri questo settore di valle è compreso tra l’armento e un’altra importante soglia di origine tettonica rappresentata dalla faglia di scorciabuoi (lentini & vezzani, 1974), una struttura lunga circa 40 km e caratterizzata da un andamento curvilineo, con direzione variabile da ono-ese a no-se (fig. 4). l’attività di questa faglia, che sembra essere iniziata nel pleistocene medio (pieri et al., 1997), è stata caratterizzata da una cinematica inizialmente di tipo traspressivo sinistro, in quanto tale struttura ha probabilmente agito come rampa lateraleobliqua del sovrascorrimento che ha prodotto l'anticlinale di rotondella (fig. 1). successivamente, nell'attuale regime tettonico estensionale che caratterizza l'asse della catena appenninica, la faglia di scorciabuoi è stata invertita acquisendo così una cinematica trastensiva destra (casciello, 2002). il tratto centrale della val d’agri scorre sulle successioni sedimentarie del bacino di sant’arcangelo, interpretato come thrust-top basin formatosi nel pliocene superiore sui sovrascorrimenti più esterni dell’appennino lucano ed evolutosi a bacino di piggyback nel pleistocene inferiore-medio (pieri et al., 1994; casciello, 1999). questo bacino è prevalentemente caratterizzato da tre sequenze deposizionali marine, d'età compresa tra il pliocene superiore e il pleistocene 164 fig. 4 carta morfotettonica della media val d’agri (settore b). legenda: 1 = substrato dei terrazzi fluviali quaternari; 2 = terrazzo fluviale i; 3 = terrazzo fluviale ii-b; 4 = terrazzo fluviale iii-b; 5 = terrazzo fluviale iv-b; 6 = superficie terrazzata v-b; 7 = immersione delle superfici terrazzate; 8 = traccia delle sezioni trasversali rappresentate in figura 5. morphotectonic map of the middle agri valley (sector b). legend: 1 =? substratum of the quaternary fluvial terraces; 2 = fluvial terrace i; 3 = fluvial terrace ii-b; 4 = fluvial terrace iii-b; 5 = fluvial terrace iv-b; 6 = terraced surface v-b; 7 = dip of the terraced surfaces; 8 = trace of the crosssections represented in figure 5. m. bianca & r. caputo inferiore, ricoperte da una sequenza sedimentaria continentale del pleistocene medio, denominata formazione di serra corneta (pieri et al., 1994). gli elementi morfologici fluviali presenti lungo questo secondo settore si sono quindi sviluppati in un intervallo compreso tra la parte alta del pleistocene medio e l’olocene. in corrispondenza del bordo orientale del bacino di sant’arcangelo, la faglia di scorciabuoi mette in contatto laterale i depositi clastici plio-pleistocenici precedentemente descritti con i terreni bacinali meso-cenozoici e i depositi silicoclastici miocenici delle unità sicilidi, strutturalmente localizzati in corrispondenza della dorsale di rotondella (pieri et al., 1997). la funzione di 'soglia' della faglia di scorciabuoi rispetto all’attività erosiva dell’agri è probabilmente legata alla presenza di litotipi caratterizzati da un grado di erodibilità sensibilmente diverso, in quanto i terreni sicilidi sono generalmente meno erodibil i dei depositi clastici del bacino di sant’arcangelo. lungo la media val d’agri sono stati riconosciuti tre ordini di terrazzi fluviali più alti del terrazzo i, che mostrano una distribuzione notevolmente asimmetrica sviluppata prevalentemente lungo la riva destra dell’agri (fig. 4). la successione terrazzata è ottimamente esposta in corrispondenza di una fascia lunga circa 12 km in prossimità dell’abitato di sant’arcangelo (riva destra), mentre in riva sinistra la serie di terrazzi è visibile solo per una distanza di alcune centinaia di metri a se dell’abitato di missanello. il profilo longitudinale dei bordi interni delle superfici terrazzate (fig. 3) evidenzia un piegamento antiforme dei terrazzi fluviali, compreso l’ultimo terrazzo alluvionale (terrazzo i). sebbene non sia possibile determinare la direzione e l’immersione dell’asse di questa anticlinale, è probabile che il suo orientamento sia analogo all’andamento assiale del sistema di strutture plicative sviluppato sui depositi marini e continentali del bacino di sant’arcangelo (fig. 4). questa analogia strutturale suggerisce che i terrazzi fluviali possano essere stati sollevati e piegati a causa dell’attività tardo pleistocenica di una faglia inversa minore sepolta e parallela alle principali strutture superficiali presenti nel settore della media val d’agri (fig. 4). inoltre, è da notare che, in corrispondenza della sezione 1 (fig. 5) tracciata a circa 3 km ad ovest di sant’arcangelo, i terrazzi fluviali occupano una fascia altimetrica compresa tra 420 m (terrazzo iv-b) e 240 m circa. le sezioni 1 e 2 (fig. 5), tracciate a poche centinaia di metri l’una dall’altra, mostrano la netta asimmetria della distribuzione dei terrazzi fluviali presenti, in questo settore, solo sul versante destro del fiume. risulta quindi evidente, in questo tratto del fiume, uno spostamento verso nord dell'attuale letto. e' probabile che gli apporti sedimentari progressivamente scaricati nell’agri dal suo affluente di destra fiumarella di roccanova abbiano causato tale migrazione dell’asta fluviale principale, favorendo così l'erosione dei terrazzi fluviali che presumibilmente si erano formati anche sul versante settentrionale. in alternativa a tale ipotesi, legata alle normali dinamiche fluviali erosivo-deposizionali, è però verosimile imputare tali variazioni altimetriche (longitudinale e trasversale) a fenomeni deformativi recenti associati alle strutture plicative presenti in questo settore del bacino di sant'arcangelo (fig. 4). le osservazioni eseguite in corrispondenza del tratto vallivo intersecato dalla faglia di scorciabuoi hanno fornito le seguenti indicazioni sull’attività di questa struttura. il profilo longitudinale del letto fluviale attuale (fig. 3) mostra una leggera variazione di pendenza in corrispondenza dell’intersezione con la faglia di scorciabuoi, non permettendo però di separare l'effetto dovuto alla tettonica da quello legato alle diverse litologie incise dal fiume. l'evidente deviazione quasi ad angolo retto del corso dell’agri, che a pochi km a sud della faglia passa da una direzione circa e-w ad una direzione circa nne-sso, sembra invece geometricamente compatibile con una dislocazione cumulativa chilometrica associata alla cinematica trascorrente sinistra, già ipotizzata per questa struttura (casciello, 2002). dall'analisi della morfologia del fiume, comunque, non si hanno elementi per riconoscere l'evidenza di una attività tettonica recente di questa faglia che è stata ipotizzata come struttura sismogenica, potenzialmente associata all'evento sismico della basilicata del 1857 (lizza, 2001). settore c: bassa val d’agri il settore più basso della val d’agri è caratterizzato non solo dalla presenza di tre ordini di terrazzi fluviali ben definiti, ma anche da una sequenza di sei terrazzi marini che si estendono lungo il tratto costiero ionico adiacente alla foce del fiume (fig. 6a). analogamente ai terrazzi fluviali, anche quelli marini vengono indicati con cifre romane crescenti procedendo dall’ordine più 165 fig. 5 sezioni trasversali del fiume agri, eseguite a ovest dell’abitato di sant’arcangelo (ubicazione in figura 4). si noti l’asimmetria dei terrazzi fluviali ii-b, iii-b e iv-b, presenti solo sul fianco meridionale della valle (sezione 1), e la migrazione del fiume verso nord in concomitanza con il sollevamento del terrazzo i (sezione 2). cross-sections of the agri valley, traced west to the sant’arcangelo village (for location, see fig. 4). the asymmetry of terraces ii-b, iii-b and iv-b, occurring only along the southern flank of the valley (section 1), and the northward migration of the agri river in the area where the terrace i is uplifted (section 2) are observed. analisi morfotettonica ... basso e recente verso quello più alto e più antico. dal punto di vista sedimentario, i terrazzi costieri sono costituiti da depositi marini conglomeratico-sabbiosi caratterizzati dalla classica geometria cuneiforme legata all’aumento di spessore che si osserva procedendo dal bordo interno al bordo esterno di ogni singolo terrazzo. questi corpi sedimentari terrazzati poggiano in discordanza sulle argille marnose grigio-azzurre dell’avanfossa bradanica (fig. 1), il cui tetto stratigrafico è attribuito al pleistocene inferiore (carbone et al., 1991). i cinque ordini di terrazzi più bassi (fig. 6b) sono 166 fig. 6 a) carta morfotettonica della bassa val d’agri (settore c). legenda: 1 = substrato dei terrazzi fluviali e marini quaternari; 2 = terrazzo fluviale i e terrazzo marino i-m; 3 = terrazzo fluviale ii-c e terrazzo marino ii-m; 4 = terrazzo fluviale iii-c e terrazzo marino iii-m; 5 = terrazzo marino iv-m; 6 = terrazzo marino v-m; 7 = terrazzo marino di ordine vi-m; 8 = bordo interno di terrazzo marino e/o fluviale con relativa quota in metri s.l.m. b) panoramica da s della serie di terrazzi marini dell’area di montalbano, localizzati lungo il versante sinistro della bassa val d’agri (settore c) e poggianti in discordanza sulle argille azzurre plio-pleistoceniche dell’avanfossa bradanica. in primo piano, il terrazzo fluviale i. il terrazzo marino più basso (i-m) non è visibile. a) morphotectonic map of the low agri valley (sector c). legend: 1 = substratum of the quaternary fluvial and marine terraces; 2 = fluvial terrace i and marine terrace i-m; 3 = fluvial terrace ii-c and marine terrace ii-m; 4 = fluvial terrace iii-c and marine terrace iii-m; 5 = marine terrace iv-m; 6 = marine terrace v-m; 7 = marine terrace vi-m; 8 = inner edge of fluvial and/or marine terrace and its elevation in m a.s.l b) view from s to n of the sequence of marine terraces of the montalbano area, developed along the left flank of the agri valley and overlying the plio-pleistocene clays of the bradanic foredeep. in the foreground, the fluvial terrace i. the lowest marine terrace i-m is not visible. m. bianca & r. caputo delimitati verso monte dalle loro rispettive paleolinee di costa, mentre il terrazzo più alto, sul quale è stata costruita la parte più antica dell’abitato di montalbano, è rappresentato da una superficie isolata che verso l’entroterra si interrompe bruscamente in corrispondenza di un versante calanchivo inciso sulle sottostanti argille azzurre. i tre ordini di terrazzi fluviali presenti su ambedue le rive del fiume (iii-c, ii-c e i), mostrano una chiara continuità fisica con i terrazzi iii-m, ii-m e i-m, rispettivamente. infatti, è facile osservare come ogni coppia di terrazzo fluviale e terrazzo marino correlati sia delimitata a monte dallo stesso bordo interno che, in prossimità della costa, curva ad angolo retto, passando da un’orientazione perpendicolare alla costa ad un’orientazione parallela ad essa. questo tipo di correlazione morfologica è sufficiente per confermare che i tratti di scarpata paralleli alla linea di costa attuale sono sicuramente interpretabili come bordi interni di terrazzi marini, escludendo la possibilità che si tratti di eventuali scarpate di faglie dirette che dislocano verticalmente un singolo terrazzo marino. inoltre, il segnale eustatico assieme al sollevamento tettonico rappresentano evidentemente i fattori morfogenici più importante anche per la formazione dei terrazzi fluviali presenti lungo il tratto finale del fiume agri. per quanto riguarda i terrazzi marini che sono presenti in prossimità della foce dell’agri, si è utilizzato un modello di deformazione basato sull’assunzione generale secondo cui una successione marina terrazzata pleistocenica rappresenta il risultato geomorfologico più evidente dell’interazione tra il sollevamento tettonico di un’area costiera e le oscillazioni glacio-eustatiche globali del livello marino (selli, 1962; lajoie, 1986; westaway, 1993; bosi et al., 1996; armijo et al., 1996; bianca et al., 1999). le oscillazioni glacio-eustatiche quaternarie sono state oggetto di numerosi studi precedenti (chappell, 1974; ward, 1985; chappell & shackleton, 1986; aharon & chappell, 1986; shackleton, 1987; chappell et al., 1996), che hanno consentito l’elaborazione di un modello di curva eustatica (fig. 8), riferita agli ultimi 400 ka e che può essere ormai considerata sufficientemente affidabile e valida a scala globale. la curva eustatica evidenzia come il livello marino abbia subito oscillazioni assolute di circa 120-130 m, tra le fasi glaciali di basso eustatico (picchi 'freddi', indicati con le cifre pari) e le fasi interglaciali di alto eustatico (picchi 'caldi', indicati con le cifre dispari). inoltre, è importante osservare che negli ultimi 400 ka il mare ha superato il livello attuale soltanto durante lo stadio interglaciale 5.5 (125 ka), detto eutirreniano (+6 m; chappell & shackleton, 1986). un singolo terrazzo marino è costituito da un insieme più o meno complesso di elementi erosivi e deposizionali (bordi interno ed esterno, superficie superiore, deposito marino, ecc.) formatosi durante una fase di stazionamento relativo del livello marino rispetto alla terraferma. verso monte, il terrazzo marino è delimitato del bordo interno, che corrisponde alla paleolinea di costa relativa al livello massimo raggiunto dal mare durante la relativa fase di alto stazionamento eustatico (bloom et al., 1974; ota, 1994; bosi et al., 1996). lungo un’ipotetica fascia costiera non soggetta a movimenti tettonici verticali, sarebbe quindi possibile osservare un unico terrazzo marino con la relativa paleolinea di costa, assieme al suo corrispondente terrazzo fluvio-alluvionale lungo l’ultimo tratto degli eventuali corsi d’acqua presenti, tutti correlati allo stadio oit 5.5 (eutirreniano, 125 ka), mentre le eventuali tracce di stazionamento marino degli altri stadi interglaciali sarebbero attualmente sommerse. una paleolinea di costa rappresenta quindi un elemento morfologico, originariamente orizzontale, formatosi ad una quota assoluta deducibile, in seguito ad una sua datazione diretta o indiretta, dalla curva eustatica di riferimento. la quota attuale (qf) di una paleolinea di costa è funzione della sua età, della quota iniziale (qi) alla quale si è formata e della velocità del sollevamento tettonico (st), secondo la formula: qf = (età x st) + qi dalla quale si può ricavare il sollevamento tettonico st= (qf qi) / età. di conseguenza, le quote assolute di una serie di paleolinee di costa datate, misurate lungo sezioni trasversali, consentono di ottenere dei diagrammi di velocità di sollevamento che quantificano la storia deformativa dell’area costiera in esame. e’ importante rilevare che un tasso di sollevamento medio di 0,2-0,3 mm/a è sufficiente per consentire la 'fossilizzazione' dell’intera successione di terrazzi marini relativi ai principali picchi interglaciali della curva eustatica (bianca, 1998), a partire dal terrazzo di età corrispondente all’inizio del processo di sollevamento. tuttavia, perché ciò si verifichi è necessario che il processo di sollevamento sia continuo per un intervallo di tempo dell’ordine di 104-105 anni, corrispondente al periodo delle principali oscillazioni eustatiche (fig. 7a). questo modello di morfogenesi assume una particolare importanza nello studio dei settori costieri terrazzati in cui le evidenze geomorfologiche, possibilmente integrate con almeno un vincolo cronologico assoluto, confermano la persistenza di un processo di sollevamento tettonico quaternario continuo e sufficientemente veloce, in quanto consente la datazione indiretta dell’intera successione di terrazzi marini. gli studi precedenti sulla distribuzione dei terrazzi marini presenti lungo il settore costiero dell’avanfossa bradanica sono concordi nell’attribuire l’intera successione terrazzata al pleistocene medio-superiore (de marco, 1990; amato et al., 1997). la presenza stessa di sei ordini di terrazzi marini medio-suprapleistocenici rappresenta l’evidenza geomorfologica più convincente del fatto che questo settore costiero è stato interessato da un sollevamento tettonico sufficientemente rapido da consentire la registrazione morfologica di una serie continua di alti stazionamenti marini corrispondenti ad alcuni dei principali picchi interglaciali della curva eustatica globale (fig. 7a). sebbene nessuno dei terrazzi marini analizzati in questo lavoro sia stato datato, alcune datazioni assolute sono state eseguite su alcuni terrazzi presenti immediatamente a sud della foce dell’agri. in particolare, nei pressi di rocca imperiale, un terrazzo posto a circa 100 m di quota è stato attribuito allo stadio isotopico 5.3 tendente al 5.5 (fig. 7a), che corrisponde ad un’età compresa tra 100 e 125 ka (amato et al., 1997). poiché la nostra interpretazione del numero di terrazzi marini non concorda con quella di amato et al. (1997), non è possibile correlare il terrazzo datato con uno dei terrazzi analizzati nel presente lavoro. tuttavia, questa datazione costituisce un importante vincolo per l’interpretazione cronologica della successione terrazzata presente lungo il tratto costiero della foce dell’agri. 167analisi morfotettonica ... sulla base del modello morfogenico precedentemente discusso e delle datazioni disponibili in aree limitrofe, abbiamo utilizzato le quote delle cinque paleolinee di costa più recenti, misurate lungo la sezione 3 (fig. 6a), proponendo così quattro ipotetici modelli quantitativi di deformazione verticale (figg. 7b-e). questi modelli sono stati ottenuti ipotizzando quattro diverse età per il terrazzo v-m, corrispondenti rispettivamente agli stadi interglaciali oit 11.1 (410 ka), 9.3 (330 ka), 7.5 (240 ka) e 7.1 (200 ka) della curva eustatica (fig. 7a), attribuendo così ai terrazzi più recenti le età dei picchi interglaciali successivi. i diagrammi così ottenuti descrivono quattro diverse ipotesi di evoluzione morfotettonica del settore costiero della val d’agri, con tassi di sollevamento medi decrescenti all’aumentare dell’età ipotetica del terrazzo v-m (fig. 7b). i relativi diagrammi (figg. 7b, 7c and 7d) mostrano tassi di sollevamento notevolmente variabili durante gli ultimi 200-300 ka, compresi tra circa 0,2 mm/a (fig. 7d) e 2,8 mm/a (fig. 7b). il diagramma rappresentato in figura 7e, ottenuto ipotizzando un’età di 410 ka (oit 11.1) per il terrazzo v-m, indica un tasso di sollevamento più costante, compreso tra 1,1 e 0,8 mm/a fino a 125 ka (oit 5.5), che si riduce quasi a zero da 125 ka ad oggi. nei diagrammi sono anche indicati i tassi medi di sollevamento, che ovviamente decrescono con l'aumentare dell'età ipotetica del terrazzo v-m, variando da 1,35 mm/a a 0,64 mm/a. un altro dato importante sulla deformazione tettonica medio-suprapleistocenica del settore costiero della val d’agri è stato ottenuto dell’analisi della proiezione longitudinale dei cinque ordini di paleolinee di costa (fig. 8) lungo una direzione nne-sso (sezione 4 in fig. 6a), cioè parallela alla linea di riva attuale. la proiezione mostra un basculamento evidente di tutte le paleolinee di costa dall'ordine v-m al ii-m, che, formatesi con una geometria originariamente orizzontale, mostrano attualmente un’inclinazione verso ne. la paleolinea di ordine i-m, al contrario, mostra ancora un andamento suborizzontale. questo tipo di deformazione indica chiaramente un sollevamento tettonico differenziale del settore costiero ionico, verificatosi durante il periodo compreso tra la formazione delle paleolinee v-m e i-m, la cui entità decresce gradualmente verso ne, ovvero verso il fronte di sovrascorrimento più esterno dell’appennino meridionale (figg. 1 e 6a). ccoonnssiiddeerraazziioonnii ccoonncclluussiivvee la presenza di diversi ordini di superfici terrazzate lungo l’intero corso dell’agri, assieme ad una successione di terrazzi marini localizzati in prossimità della foce, tutti riferibili al quaternario, indicano un processo di 168 fig. 7 -a) curva eustatica globale (modificata da shackleton, 1987). i numeri indicano le fasi principali di alto stazionamento del livello marino, corrispondenti agli stadi interglaciali più importanti. – b-e) diagrammi raffiguranti il processo di sollevamento tettonico del settore costiero della val d’agri, basato sulle quote attuali delle paleolinee di costa dall'ordine i-m al v-m, misurate lungo la sezione 3 (fig. 6a). i tassi di sollevamento sono stati calcolati per intervalli compresi tra due paleolinee successive, attribuendo alla paleolinea di ordine v-m quattro diverse possibili età comprese tra 200 e 410 ka. a) global eustatic curve (modified from shackleton, 1987). the numbered peaks represent the marine high-stands corresponding to the main interglacial stages. b-e) diagrams showing the tectonic uplift of the coastal area of the agri valley, based on the present elevation of the palaeoshorelines of order i-m to v-m measured along section 3 (fig. 6a). uplift rates have been calculated for time spans between two consecutive palaeo-shorelines, assuming four different ages for the marine terrace v-m in the interval 200-410 ka. fig. 8 proiezione longitudinale delle paleolinee di costa (tratteggiate quando interpolate) di ordine compreso tra i-m e v-m lungo una direzione parallela alla costa attuale, orientata nnesso (traccia 4 in fig. 6a). il diagramma mostra un evidente basculamento delle paleolinee, originariamente orizzontali, la cui quota decresce verso nne. longitudinal projection of the palaeo-shorelines (dashed where inferred) of order i-m to v-m along a nne-ssw-striking direction, parallel to the present coastline (trace 4 in fig. 6a). a tilting of the coastal area, indicated by north-northeastward decreasing elevations of the palaeo-shorelines, can be observed. m. bianca & r. caputo approfondimento continuo e articolato di questa valle che si è protratto, con l’eccezione del tratto iniziale dell’alta val d’agri, fino all’olocene. il continuo abbassamento del livello di base dell’erosione dell’agri rappresenta la conseguenza più evidente del processo di sollevamento tettonico che ha interessato questo settore di appennino lucano e di avanfossa bradanica durante il quaternario (fig. 1). l’entità dei movimenti verticali positivi deve essere considerata come la risultante del sollevamento tettonico regionale, tipicamente diffuso e generalmente uniforme alle scale ridotte, e della componente di sollevamento localmente legata all’attività di possibili strutture neotettoniche. i risultati di questo studio morfotettonico hanno consentito di elaborare alcuni modelli qualitativi e quantitativi di evoluzione tettonica quaternaria della val d’agri, con la conseguente individuazione di alcuni settori dove le deformazioni recenti sono probabilmente legate alla presenza di strutture recenti o attive. due importanti soglie morfostrutturali, il sovrascorrimento dell’armento e la faglia di scorciabuoi (fig.1), intersecano ad alto angolo il corso dell’agri, suddividendo la valle in tre settori caratterizzati da una evoluzione morfologica quaternaria differenziata. in alta val d’agri, i processi erosivi e deposizionali sembrano regolati principalmente dalle fasi più recenti di sollevamento relativo della soglia posta in corrispondenza dell’anticlinale dell’armento. l’ultima fase di sollevamento di questa soglia, infatti, ha permesso la formazione del 'paleolago' del pertusillo e l’inizio della sedimentazione del complesso val d’agri durante il pleistocene medio-superiore. l'incisione della soglia da parte del fiume agri per erosione regressiva indotta dal sollevamento regionale causa il progressivo svuotamento del lago e l'incisione parziale degli stessi depositi fluviolacustri del complesso val d’agri. i terrazzi fluviali più recenti, probabilmente olocenici, rappresentano il risultato morfologico di fasi di sollevamento episodiche che riteniamo indipendenti dalle oscillazioni eustatiche del livello marino, e che potrebbero quindi essere collegate all’attività recente di una o più strutture bordiere dell’alta val d’agri e, in misura minore, ad effetti climatici. in media val d’agri, i terrazzi fluviali medio-suprapleistocenici e olocenici evidenziano una geometria antiforme che sembra strutturalmente compatibile con le principali strutture fragili e plicative che deformano i terreni plio-pleistocenici del bacino di sant’arcangelo. e’ quindi ipotizzabile che il regime tettonico compressivo orientato circa ne-so sia perdurato fino all’olocene. la possibile presenza di una o più strutture sismogeniche nella media val d’agri (lizza, 2001) potrebbe inoltre spiegare la forte intensità macrosismica (i=x mcs) registrata dai centri abitati di aliano e alianello durante il terremoto della basilicata del 1857 (m=6.5; boschi et al., 1995). infine, in bassa val d’agri, la buona correlazione geometrica tra terrazzi fluviali e marini sottolinea il ruolo determinante delle variazioni eustatiche nei processi morfogenici che hanno modellato questo settore di valle. in base all’ipotesi che la successione terrazzata del pleistocene medio-superiore rappresenti una serie continua di elementi morfologici correlati con alcune delle principali fasi interglaciali indicate dalla curva eustatica di riferimento, sono state elaborate quattro ipotesi alternative che quantificano i tassi di sollevamento del settore costiero della foce dell’agri. la notevole variabilità dei tassi di sollevamento, gli alti valori dei tassi più elevati (~3 mm/a) e l’evidente basculamento delle paleolinee di costa, suggeriscono che il sollevamento di quest’area sia da associare all’attività recente di una o più strutture tettoniche presenti in questo settore esterno di catena appenninica, e non soltanto al sollevamento regionale, che viene normalmente considerato più costante, omogeneo e caratterizzato da velocità meno elevate. rriinnggrraazziiaammeennttii si ringraziano m. schiattarella, i. giano, m. mattei per le numerose discussioni. la ricerca è stata svolta con fondi miur (cofin 2000, resp. m. schiattarella) e dell'università della basilicata (resp. r. caputo). bbiibblliiooggrraaffiiaa aharon p. & chappell j., 1986 – oxygen isotopes, sea level changes and the temperature history of a coral reef environment in new guinea over the last 105 years. paleogeogr. paleoclim. paleoec., 56, 33//44, 337-379. amato a., belluomini g., cinque a., manolio m. & ravera f., 1997 – terrazzi marini e sollevamenti tettonici quaternari lungo i l margine ionico dell’appennino lucano. il quaternario, 1100 ((22)), 329336. armijo r., meyer b., king g.c.p., rigo a. & papanastassiou d., 1996 – quaternary evolution of the corinth rift and its implications for the late cenozoic evolution of the aegean. geophys. j. int., 112266, 11-53. bianca m., monaco c., tortorici l. & cernobori l., 1999 – quaternary normal faulting in southeastern sicily (italy): a seismic source for the 1693 large earthquake. geophys. j. int., 113399, 370-394. bianca m., 1998 – tettonica recente ed attiva del bordo orientale dell’avampaese ibleo. tesi di dottorato, università di camerino, 1998. bloom a.l., broecker w.s., chappell j., matthews r.k. & mesolella k.j., 1974 – quaternary sea level fluctuations on a tectonic coast; new 230th/234u dates from the huon peninsula, new guinea. quat. res., 44,, 185-205. bosi c., carobene l. & sposato a., 1996 – il ruolo dell’eustatismo nella evoluzione geologica nell’area mediterranea. mem. soc. geol. it., 5511, 363-382. boschi e., ferrari g., gasperini p., guidoboni e., smriglio g. & valensise g., 1995 – catalogo dei forti terremoti in italia dal 461 a.c. al 1980. istituto nazionale di geofisica, s.g.a., roma. burbank d.w. & anderson r.s., 2001 – tectonic geomorphology. blackwell science, 274 pp. burrato p., 1995 – tettonica attiva, sismogenesi e caratteri evolutivi del reticolo idrografico: tre esempi dall'italia meridionale. tesi di laurea, università "la sapienza", 69 pp., roma. carbone s., catalano s., lazzari s., lentini f. & monaco c., 1991 – presentazione della carta geologica del bacino del fiume agri (basilicata). mem. soc. geol. it., 4477, 129-143. casciello e., cesarano m., ferranti l., oldow j.s. & 169analisi morfotettonica ... pappone g., 2000 – pleistocene non-coaxial fold development in the northern portion of the s. arcangelo basin (southern apennines). mem. soc. geol. it., 5555, 133-140. casciello e., 1999 – analisi strutturale di un bacino sintettonico plio-pleistocenico dell’appenino meridionale: il bacino di sant’arcangelo (potenza). tesi di dottorato, università di camerino. casciello e., 2002 deformazioni da taglio in materiali argillosi: analisi dei sedimenti deformati dalla faglia di scorciabuoi. studi geologici camerti, 11, nuova serie, 51-62. chappell j. & shackleton n.j., 1986 – oxygen isotopes and sea level. nature, 332244, 137-140. chappell j., omura a., esat t., mcculloch m., pandolfi j., ota y. & pillans b., 1996 reconciliation of late quaternary sea levels derived from coral terraces at huon peninsula with deep sea oxygen isotope records. earth planet. sci. lett., 114411, 227-236. chappell j., 1974 – geology of coral terraces, huon peninsula, new guinea: a study of quaternary tectonic movements and sea-level changes. bull. geol. soc. am., 8855, 553-570. cinque a., patacca e., scandone p. & tozzi m., 1993 – quaternary kinematic evolution of the southern apennines. relationship between surfaces geological features and deep lithospheric structures. ann. geofis., 3366 (2), 249-259. d’argenio b., pescatore t. & scandone p., 1973 – schema geologico dell’appennino meridionale. atti convegno: moderne vedute sulla geologia dell’appennino. acc. naz. lincei, 118833,, 49-72. di niro a., giano s.i. & santangelo n., 1992 – primi dati sull'evoluzione geomorfologica e sedimentaria del bacino dell'alta val d'agri (basilicata): volume speciale 11999922//11, 257-263. de marco a., 1990 – rapporti tra geodinamica e sedimentazione nella fossa bradanica durante il pleistocene: testimonianze mineralogiche. boll. soc. geol. it., 110099, 313-324. giano s.i., lapenna v., piscitelli s. & schiattarella m., 1997 – nuovi dati geologici e geofisici sull’assetto strutturale dei depositi continentali quaternari dell’alta val d’agri (basilicata). il quaternario, 1100((22)), 589-594. lajoie k. r., 1986 – coastal tectonics. studies in geophysics, 95-124, national academy press, washington. lentini f. & vezzani l., 1974 – note illustrative del foglio 506 s. arcangelo. i.r.p.i cnr (cosenza), 46 pp. lizza c., 2001 – il terremoto della basilicata 1857: individuazione della sorgente con tecniche geofisiche. tesi di laurea, università della basilicata, potenza. ota y., 1994 – study on coral reef terraces of the huon peninsula, papua new guinea. yokohama national university, japan, 429 pp. pieri p., sabato l., loiacono f. & marino m., 1994 – il bacino di piggy back di sant'arcangelo: evoluzione tettonico-sedimentaria. boll. soc. geol. it., 111133, 465-481. pieri p., vitale g., beneduce p., doglioni c., gallicchio s., giano s.i., loizzo r., moretti m., prosser g., sabato l., schiattarella m., tramutoli m. & tropeano m., 1997 – tettonica quaternaria nell'area bradanico-ionica. il quaternario, 1100((22)), 535542. scandone p., 1967 – studi di geologia lucana: la serie calcareo-silico-marnosa e i suoi rapporti con l’appennino calcareo. boll. soc. natur. napoli, 7766, 1-175. scandone p., 1971 – note illustrative della carta geologica d’italia alla scala 1:100.000. fogli 199 (potenza) e 210 (lauria). servizio geologico d’italia. schumm s.a., dumont j.f. & holbrook j. m., 2000 active tectonics and alluvial rivers. cambridge university press, 276 pagg. selli r., 1962 – le quaternaire marin du versant adriatique-jonien de la péninsule italienne. quaternaria, 66, 391-413. shackleton n.j., 1987 – oxygen isotopes, ice volume and sea level. quaternary science reviews, 66, 183-190. vandenberghe j., 2002 – the relation between climate and river processes, landforms and deposits during the quaternary. quaternary international, 9911, 17-23. ward w. t., 1985 – correlation of east australian pleistocene shorelines with deep-sea cores stages: a basis for a coastal chronology. geol. soc. am. bull., 96, 99, 1156-1166. westaway r., 1993 – quaternary uplift of southern italy. j. geophys. res., 9988, 21741-21772. 170 ms. ricevuto il 7 gennaio 2003 testo definitivo ricevuto il 24 giugno 2003 ms. received: january 7, 2003 final text received: june 24, 2003 m. bianca & r. caputo amq sr06 reitner et al 165-181.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 33 (2), 2020, 165-181 the early holocene buchwiese rock avalanche (eastern alps, austria): geological conditions, kinematics, morphological and sedimentary legacy. jürgen m. reitner 1, susan ivy-ochs 2, olivia steinemann 2, daniela lattner 3, alexander römer 1 1 geologische bundesanstalt / geological survey of austria, vienna, austria. 2 laboratory of ion beam physics, eth zurich, zurich, switzerland. 3 former member of the geological survey of austria, vienna, austria. corresponding author: j.m. reitner <juergen.reitner@geologie.ac.at> abstract: in this study we reconstructed the buchwiese rock avalanche in the lienz dolomites in eastern tyrol (austria). we used a multi-method approach combining geological field mapping, the analysis of digital elevation model (dem) data, cosmogenic 36cl exposure dating, and a geoelectrical survey to unravel the detachment mechanisms, emplacement processes and timing of the buchwiese rock avalanche. according to the results of the 36cl exposure dating, the event took place at 10.8±0.9 ka during the early holocene. the failure of a rock mass with a volume of 27x106 m3 was enabled by a dip-slope in strata of the kössen formation (limestone, marls, claystone), oberrhätkalk (massive to thickly bedded limestone), allgäu formation (mottled limestone and marl) and rotkalk (red nodular limestone and marl), in combination with n-s to nne-ssw trending brittle faults. we regard fatigue of the fine-grained rocks of the kössen fm. (claystone, marl), typical slaking rocks, since the last glacial maximum as the major cause for this catastrophic rock slope failure. with the reconstructed drop height (h) of 1200 m and runout length (l) of 3.5 km, the buchwiese rock avalanche has a fahrböschung angle α of 19° and h/l ratio of 0.36. due to the geological conditions, the initial failure occurred as a plane slide. in the deposition area, we observe strong control of lithological properties, topographic conditions, and substrate materials along the pathway on the morphology and sedimentology of the rock avalanche deposit. longitudinal ridges, indicating spreading of an unconfined flow, are comprised mostly of massive limestone (oberrhätkalk). the carapace facies consisting of clast-supported boulders is only developed in areas with limestone (mostly oberrhätkalk but also limestone of the kössen fm.). the body facies in the upper parts are dominated by jigsaw subfacies with a subordinate occurrence of fragmented subfacies in the outcrops. even in the middle part of the deposition area, we observe the prevalence of the moderately fragmented jigsaw subfacies within large areas of kössen fm. debris, which consists of alternating claystone, limestone beds. such a finding may indicate preferential deformation within the claystone beds. after partial collision with a bedrock ridge and a small jump, the fragmented subfacies dominates. this collision led to the formation of a fan-like megaboulder cluster consisting of detached and fragmented oberrhätkalk boulders with volumes up to 1000 m3 and a fan-like distribution. the results of geoelectrical surveys reflect different amounts of fragmentation with the carapace facies, showing high resistivity, while the body facies reveals low resistivity. preserved source stratigraphy within the dilated rock mass indicates predominantly laminar rock avalanche movement. all the morphological and sedimentary evidence supports a dynamic fragmentation model as the best mechanical explanation for the buchwiese rock avalanche. keywords: rock avalanche, fragmentation, cosmogenic 36cl exposure dating, holocene, eastern alps. 1. introduction large catastrophic rock slope failures (rock slides, rock avalanches) with volumes of >106 m3 are rare but are nevertheless perhaps the most spectacular forms of mass displacement in high-relief mountains (abele, 1974). they suddenly change landscapes and have been perceived in human history as catastrophes. due to the usually surprising occurrence of such rapid landslides, the enormous amount of energy released as a result and corresponding dust formation, there are no direct observations of the processes like internal and basal facies fragmentation (hewitt et al., 2008). our understanding of catastrophic rock slope failures, their mechanics and kinematics, mostly relies on the study of paleo-events and thus on the morphological and geological legacy of such processes (heim, 1932; abele, 1974; erismann & abele, 2001). among these catastrophic rock slope failures, rock avalanches are the most fascinating features due to high velocities of more than 200 km/h and due to an extremely long runout (heim, 1932; abele, 1974; hewitt et al., 2008). the comprehension of how rock is transformed to a highly fragmented material that acts like a laminar fluid with reduced friction is one of the great challenges in landslide research (hungr et al., 2005; davies & mcsaveney, 2009; imre et al., 2010; aaron & mcdougall, 2019). thus, the description of lithological properties of original and crushed bedrock may, together with that of morphological features, provide a sound basis for a better understanding of the processes involved (dunning, 2004; crosta et al., 2007; weidinger et al., 2014; dufresne et al.; 2016a, b; dufresne & dunning, 2017) and for modelling approaches (e.g. https://doi.org/10.26382/amq.2020.12 166 reitner j.m. et al. 167 aaron et al., 2020; singeisen et al., 2020). in addition, there is great societal interest, especially in countries with increasingly populated alpine valleys, in the potential danger related to such rapid landslides. hence, a better perception of causes and triggers of such hazards ranging e.g. from material fatigue, over earthquakes to climate change and, finally, of the chronology of processes before the failure are of eminent importance (e.g. eisbacher & clague, 1984; zerathe et al., 2014; wood et al., 2015). recent progress in geochronology, especially the application of surface exposure dating with terrestrial cosmogenic nuclides like 10be and 36cl (ivy-ochs & kober, 2008) together with 14c and u/th dating (prager et al., 2008; ostermann et al., 2007, 2017) is enabling a tremendous extension of the dated paleolandslide record in the alps (prager et al., 2008; ivy-ochs et al., 2017; pánek, 2019). bauer (1990) first mentioned a rock avalanche deposit in the study area. reitner (2003a) provided a first detailed map and description of the buchwiese rock avalanche with an estimated volume of c. 22x106 m3. in this paper, we present new geological, geochronological and geophysical data of the reconstructed pre-historical buchwiese rock avalanche, as a contribution to research on catastrophic landslides in the alps. the aim of this study is to show the influence of different lithologies and thus rock properties together with that of topographic conditions and substrate materials along the pathway on the morphology and sedimentology of the rock avalanche deposit. 2. geological setting and previous research the study area is located in eastern tyrol on the northern flank of the lienz dolomites mountain group within the eastern alps, c. 5 km se of the city of lienz in the drau valley (fig. 1, 2). tectonically, the lienz dolomites mountain group is part of the austroalpine superunit and, more specifically, of the drauzug-gurktal nappe system (schmid et al., 2004; schuster et al., 2014). the latter is subdivided in the study area into the lienzdolomites nappe and the kreuzeck-gailtaler-alpen nappe (linner et al., 2013). <<< ------------------ fig. 1 maps showing (a) the location of the study area and (b) the geology (modified after linner et al., 2013). contour interval is 100 m. the bold steepled black line shows the traces of the geological profile in fig. 3. the early holocene buchwiese rock avalanche fig. 2 view from the opposite drau valley flank on the study area and surrounding. the yellow steepled line shows the run of the scarp of the buchwiese rock avalanche followed by the deposition area surrounded by the white line. note the subglacially shaped peaks like rauchkofel and auerlingköpl in contrast to the rugged peaks above like spitzkofel indicating nunataks during the lgm. numbers indicate following locations: 1 weissstein, 2 rossboden, 3 longitudinal ridge with boulders lienz 5 and lienz 6, 4 kreithof, 5 kohlstatt creek, 6 buchwiese. the source area and the upper and middle part of the deposition area of the buchwiese rock avalanche are made up of rocks of the tectonically higher lienzdolomites nappe (figs. 1, 3), which occur in the amlacher wiese syncline (schmidt, 1995; blau & grün, 1995). the lowermost part of the deposition area is underlain by mica schists of the kreuzeck-gailtaleralpen nappe. descriptions of fault systems and their chronology are provided by schmidt (1995), brandner et al. (2001) and, in combination with a hydrogeological characterisation of faults and rocks, by probst et al. (2003). the scarp area is part of the southern limb of the amlacher wiesen syncline with a general dip towards the north. in the following, the lithology of the rocks in the scarp area are characterised according bauer (1990): • the kössen formation (rhätium) in the study area consists of an interbedded up to 350 m thick sequence of black pelites (claystone, marls) and dark limestone with an ochre colour due to weathering (fig. 4a). geotechnically, the fine-grained lithologies (claystone and marl) are classified as slaking rocks showing disintegration upon exposure to air or moisture in combination with an irreversible loss of strength (fig. 4b). a large number of mass movements, mostly slides and mass flows, in the northern calcareous alps in tyrol and bavaria are linked with the occurrence of this lithology (nickmann, 2009; nickmann & thuro, 2013; lotter & gruber 2020). even moderate weathering is sufficient for reaching 168 the critical state for failure (nickmann & thuro, 2013), and in a dip-slope setting the saturated kössen fm. tends to fail at slope angles of 10-15° (lotter & gruber, 2020). • the oberrhätkalk on top of the kössen fm. consists mostly of massive but sometimes thickly bedded limestone with a thickness of up to 25 m (fig. 4c). this brittle lithology makes up cliffs, like weissstein (figs. 1, 2) or bedrock ridges, like north of kreithof (fig. 5). • the allgäu formation (lower jurassic) in the scarp area consists of greenish-grey mottled limestone and marls, partly chert-bearing. the marls are also classified as slaking rocks. rotkalk (red nodular limestone and marl; pliensbachium tithonium) has a thickness of 7 to 17 m (blau & grün, 1995). during the last glacial maximum (lgm; = würmian pleniglacial) the area was covered by the drau glacier, which was part of the large alpine transection glacier complex (reitner et al., 2016). the ice surface was in the range of 2200 m a.s.l. (reitner, 2003b) with only the highest sharp peaks (fig. 2) as nunataks above. subglacial till consisting of a matrix-supported and massive diamicton showing a high consolidation is typical of temperate glaciers of the lgm (reitner & menzies, 2020). glacial erosion is evident in the overdeepened lienz basin with a maximum bedrock depth of c. 600 m below the valley floor just north of the study area (burschil et al., 2019). additional documents of subglacial shaping are the mica schist areas within the small -------------->>>>> fig. 4 images from the field in the scarp (s) area and in the uppermost deposition area (a) : 4a) outcrop s-1 (for location see fig. 1) with the typical appearance of the nortward dipping kössen fm. as an alternation of limestone, marl and claystone beds (1m scale). 4b) close up of claystone showing a disintegration typical for slaking rock (1m scale). 4c) view from east towards the weissstein consisting of massive to thickly bedded oberrhätkalk limestone. 4d) subordinate scarp at s-2 with the northward dipping kössen fm (dip 360/56) in a typical dip-slope situation. note encircled person for scale. 4e) the boulder lienz 5 consisting of massive oberrhätkalk limestone sampled for 36cl exposure dating at the outer flank of uppermost longitudinal ridge. note the rounded edges. 4f) outcrop a-1 at the same ridge as lienz-5 (in fig. 4e) showing clast supported diamicton (lithofacies scc) with very angular oberrhätkalk clasts. note the whitish colour of the surface due a thin, very bright, floury, calcareous precipitation (image: b. imre). 4g) outcrop a-2 with jigsaw facies within oberrhätkalk (1m scale). 4h) outcrop a-2 with fragmented facies consisting of a diamicton with very angular clasts of the kössen fm. limestone (1m scale) (image: b. imre). fig. 3 geological profile of the rock avalanche area and the sequence of processes during rock avalanche formation and emplacement (for location see fig. 1). reitner j.m. et al. 169 the early holocene buchwiese rock avalanche basin of lake tristach (fig.1) as well as rounded peaks like the rauchkofel (fig. 2) and the abraded bedrock ridge north of kreithof (fig. 5). following the climax of the lgm (27-19 ka; monegato et al., 2007; ivy-ochs, 2015), remnants of delta deposits document the brief early lateglacial phase of ice-decay (~19 ka) in the study area (reitner et al., 2016). by 18.5 ka the glacier tongue area (schmidt et al., 2002) and all major alpine valleys (van husen, 2000), like the drau valley at lienz, were free of ice. afterwards no lateglacial advances affected the study area. the following phase was characterised by infill of the overdeepened basin (burschill et al., 2019) and by fluvial erosion. on the surrounding slopes, different types of mass movements occurred ranging from deep-seated slope deformations to rock slides and rock avalanches (bauer, 1990; reitner, 2003 a, b; reitner et al., 2014; reitner & linner, 2009). the area of lienz has low seismicity (cf. reiter et al., 2018) with no faults known to be tectonically active. 3. methods geological mapping at the 1:10,000 scale was performed in the year 2000 (reitner, 2003a) for the geological map sheet lienz (linner et al., 2013). further morphological analysis of the mostly forested terrain benefitted from available high-resolution airborne laser scanning data and a digital elevation model (dem) with 1-m resolution, which were provided by tiris (www.tirol.gv.at/) since 2010. for lithofacies descriptions, we applied the coding of keller (1996). we performed landslide volume estimations by reconstructing a pre-failure surface of the scarp area and calculating the differential volume of this surface and the present surface (dem) in arcmap. 2.5-dimensional models were produced using arcscene. we took four samples from the tops of the largest boulders in the buchwiese rock avalanche deposit for cosmogenic 36cl surface exposure dating in november 2007. all sampled boulders are of oberrhätkalk limestone. sample information is given in tab. 1. sample preparation followed the method of isotope dilution (35cl) described in ivy-ochs et al. (2004). total cl and 36cl were measured in the same target at the eth accelerator mass spectrometry (ams) facility of the laboratory for ion beam physics (lip) with the 6 mv tandem. measured 36cl/cl ratios were normalized to 170 the eth internal standard k382/4n with a value of 36cl/ cl =17.36×10-12, which is calibrated against the primary 36cl standard knstd5000 (vockenhuber et al., 2019). measured ratios were corrected for a full process chemistry blank value of 4.2±3.6×10-15. we calculated 36cl exposure ages with the lip eth in-house matlab tab. 1 sample information and results of 36cl surface exposure dating. fig. 5 dem showing characteristic morphological elements in the lower part of the deposition areas b and c. the most striking features are the bedrock ridge north of kreithof, the fan-like morphology sw of kreithof and the megaboulder cluster surrounded by a black steepled line. the rock avalanche deposit is indicated in orange. pink triangles show the cluster of rotkalk boulder. the red line shows the run of the geoelectrical profile p1. reitner j.m. et al. code based on the parameters presented in alfimov & ivy-ochs (2009 and references therein) and the elemental composition of every rock sample (measured with icp-ms at act labs s.a., ontario, canada) (tab. 2). ages have been corrected for topographic shielding, which was measured in the field using compass and clinometer. shielding corrections were calculated with the topographic shielding calculator in the online calculator at https://hess.ess.washington.edu. ages were corrected using an erosion rate of 5 mm/ka (andré, 2002). no correction was made for snow cover; in general, such corrections are made only on bedrock samples (cf. bichler et al., 2016). final errors on the ages (tab.1) include both analytical and production rate uncertainties. we performed a geoelectrical survey to foster a 2d -image of the rock avalanche structure. landslide investigations with the integration of geoelectrical outcomes for landslide characterization, like description of landslide geometry body, can be found in perrone et al. (2004) and a comparable case study about rock avalanche deposit in ostermann et al. (2012). a good overview about theory and field design and the limitations of the resistivity method is given in aizebeokhai (2010) and loke et al. (2013). three electrical resistivity tomography (ert) profiles (p1, p2, p3; location indicated in fig. 1) were carried out in august 2012 with a geomon4d resistivity meter, an in-house development of the geological survey of austria. 93 electrodes were used with the specific layout parameters listed in tab. 3. for better resolution, we used a gradient electrode array configuration (dahlin & bing, 2006) with 4300 measurements. power input of electrical current was adequate (100 400 ma) and data quality was quite good. sample analysis showed, that electrical noise was sufficiently low and occasional 50 hz crosstalk could be eliminated with sufficient time window length. geoelectrical processing started with raw data filtering, like elimination of outliers, analysis of signal to noise ratio, etc. geoelectrical inversion was carried out with the res2dinv software (©geotomo software, malaysia). following standard procedures, we inverted geoelectrical data with a smooth inversion based on an l2-norm criterion, with an average resistivity starting model and topographic correction incorporated into the inversion (loke, 2019). 4. results 4.1 field description in order to facilitate the field description, the area is subdivided into four domains: scarp area and the deposition areas a-c (from proximal to distal, see fig. 1). scarp area the maximum 800 m wide and 0.7 km2 large detachment niche lies between the limestone bedrock ridge of weissstein (fig. 4c) in the west and the rossboden in the east (fig. 2). in the uppermost detachment area between 1700 m and 1900 m a.s.l., the niche diminishes successively in the upward direction indicating in total a missing rock mass (fig. 3). the majortiy of the detachment niche is made up of kössen fm. which shows a general dip towards north. dip angles are in the range of 30 to 50° but may vary due to small scale folding between 30° towards south and 75° towards north. given the original slope at weissstein with angle of 37° (fig. 3), a dip-slope situation is evident as indicated by large outcrops (s-1, s-2; figs. 1, 4a, 4d). in addition, still ongoing creep movement in the average 25° steep terrain results in an undulating surface (fig. 1), proof of the weak rock mechanical properties of the kössen fm. (claystone, marls). this is also visible in tension gaps and small scarps at the eastern margin of the scarp area. the weissstein is made up of up to 25 m thick oberrhätkalk (figs. 2, 4c), which is overlain on the northern flank by folded dark allgäu fm. and up to 15 m of rotkalk (figs. 1, 3). the southern margin of the detachment area north of auerlingköpfl peak (2026 m a.s.l.) consists of hauptdolomit (thick-bedded, benchforming dolostone). the presence of large dolostone boulders indicates loosening of hauptdolomit after the detachment of the rock mass consisting of kössen fm. at this location. n-s to nne-ssw oriented segments of the western scarp mirror rare minor near vertical brittle faults (at s-1in fig. 1). such a direction is also evident in the joint distribution of the outcrops and as well in lineaments (fig. 1) in the areas consisting of brittle hauptdolomit. deposition area a (schrettiswiese) just 600 m downslope of the limestone cliff of weissstein, a prominent sw-ne trending ridge marks the lateral limit of the rock avalanche deposit. this 350 m long ridge consists on the surface of large limestone boulders of oberrhätkalk (fig. 4e). the height on its outer side is around 5 m. based on the incised creek which did not reach bedrock, the thickness of the rock avalanche deposit is most likely in the range between 20 and 60 m. 171 tab. 2 elemental composition of leached samples. values below detection limit are marked with “<”. cl values are from ams measurements. tab. 3 key parameters of the electrical tomography profiles. the early holocene buchwiese rock avalanche 172 reitner j.m. et al. boulders like the one of the sample sites lienz 5 (fig. 4e) and lienz 6 (fig. 1) with a volume of up to 50 m3 can be classified as subangular to subrounded on the surface. in contrast, rare outcrops, like a-1, exhibit just 0.5 m below the surface a clast-supported scree without matrix (scc) consisting of very angular to angular clasts of gravel to boulder size (fig. 4f). the surface of the clasts is coated by a � 1 mm thick very bright, floury, calcareous precipitation. this observation indicates that the less angular clast boulder shapes on the surface are the result of weathering. outcrops in the deeper part (e.g. a-2) show material of the kössen fm. where the limestone strata are characterised by irregular fractures not in accordance with the joint patterns of the original bedrock (fig. 4g). the amount of fragmentation changes without a sharp boundary from relatively compact limestone outcrops with an extent of some metres to very angular clasts of decimetre-size. thus, this facies shows the characteristics of the “jigsaw-fractured (sub-)facies” described by dufresne et al. (2016a) as part of the body facies. at the same outcrop a-2, a matrix-supported, brownish diamicton with very angular clasts in a silty-sandy matrix displays a more intensive comminution of the “fragmented (sub-)facies” (fig. 4h). again, very angular clasts are fragmented. deposition area b (kreithof ) the middle part of the deposition area is characterised by a change of slope from around 15° above 1100 m a.s.l. to 20-25° between 1100 and 900 m a.s.l. this step occurs in the western prolongation of the bedrock ridge north of kreithof consisting predominantly of oberrhätkalk (figs. 4, 5). due to faulting (fig. 3), this massive white limestone disappears towards the west. however, the occurrence of hauptdolomit seems to be responsible for the increase in steepness. the facies of the outcrops (b-1, b-2; figs. 1, 4) is comparable to that of a-2. large outcrops of kössen fm. (marly limestone to claystone; b-1 in fig. 6a) show the lithological succession of the release area. however, the dip of the strata differs considerably from the scarp area with e.g. 315/45 to 350/52 for b-1 and 220/65 for b-2. again, mechanically competent limestone components show an internal fragmentation with irregular fractures (b-1 in fig. 6b). the occurrence of the fragmented subfacies (fig. 6c) is very restricted. in contrast, the small b-3 outcrop shows a very dense and consolidated matrix-supported diamicton (dmm) with a greyish-green to reddish silty-clayey matrix. based on the lithological characteristics this melange-like deposit represents most likely strongly fragmented allgäu fm. maybe in contact with rotkalk marls. the morphology of the deposition area shows in the central parts s-n-oriented longitudinal ridges with a height of less than 5 m, indicating the flow direction of the rock avalanche (figs. 1, 5). at the eastern limit near kreithof, a fan shaped landform with small channel-like features is evident on the dem (fig. 5). drainage trenches at site b-4 show a maximum 0.5 m thick layer of a clast-rich diamicton with gravel to cobble size clasts overlying strongly commuted dark claystone of the kössen fm., which due to weathering, appears to be a plastic silty clay. hence, this fan-shaped area has been mapped as a rock avalanche area which was finally shaped by a precursor of the kohlstatt creek after the rock avalanche event. deposition area c (buchwiese) with megaboulder cluster nw of the oberrhätkalk bedrock ridge at kreithof, the deposition area is characterised by a cluster of outstandingly large boulders (figs. 6d, 6e) consisting of white limestone (fig. 5). the areal distribution of these megaboulders with a volume between 10 and c. 1000 m3 is best described as a narrow fan with an apex on the southern end near kreithof. no ridge-like structures are evident in this area. the only ridge (max. height 5 m, c. 200 m length) with large but in general smaller boulders of the same lithology in this area is just outside the megaboulder cluster (c4 in figs. 5, 6g). rare outcrops like c-3 along the creek at the northwestern rim show that the rock avalanche deposit is underlain by polymictic delta deposits with subanglular to rounded crystalline and limestone clasts, typical for deposits of the phase of icedecay (reitner et al., 2016). the rock avalanche deposits in the distal part (c-2) comprise diamictons with angular allgäu fm. clasts in a silty-sandy matrix. in the northeastern part a small cluster of 1-2 m3 of subangular to subrounded rotkalk boulders (fig. 6f) can be mapped (c-5 in figs. 1, 5). outcrops close to the limit of the rock avalanche deposit show a < 2 m thick deposit consisting of a matrix-supported diamicton with a silty-sandy matrix on top of mica schists. the clasts consist of lithologies of “rotkalk” and allgäu fm, both originally occurring at the northern (distal) part of the scarp area. the most distal parts of the rock avalanche deposits reach down to the alluvial deposits of the river drau. however, no indications of such deposits further to the north, or of fluvially reworked deposits, have been found so far in this area which is nowadays intensively used for agriculture and a golf resort. 4.2. geophysics profile p1 (fig. 7a) shows a contrast between the bedrock, in this case made of mica schists with an electrical resistivity of > 900 ωm and the rock avalanche <<<<< ------------------ fig. 6 images from the field in middle (b) and lower part (c) of the deposition area. 6a) outcrop b1 showing a fragmented alternation of limestone and claystone beds of the kössen fm. (dip 350/52; 0.6 m long yellow pick for scale) 6b) detail from 6a with a limestone in jigsaw facies. 6c) outcrop b1 with the rare occurrence of the fragmented facies (matrix-supported diamicton with very angular clasts) (hammer length 28 cm).6d) the megaboulder cluster at site c-1. 6e) sample site lienz 7 within the megaboulder cluster. encircled head of a person for scale. note the giant boulder in the background (red x). 6f) the typical maximum size of the rotkalk (red limestone) at site c-5 (yellow hammer for scale) note the subangular shape. 6g) longitudinal ridge at site c-4. direction of view towards nw. 173 the early holocene buchwiese rock avalanche deposit. the latter with a thickness of up to 40 m reveals in general a low resistivity of 50-320 ωm. only the uppermost 10 metres can display resistivities of 900 ωm and higher, especially in the first c. 200 m where the profile crosses the megaboulder cluster (fig. 5). at the se end of the profile the bedrock crops out in accordance with the mapping results (fig. 1).the profile p2 (fig. 7b) reveals a less pronounced contrast between bedrock made of lavant fm. (siliciclactic limestone, marl, siltstone; resistivity 85-200 ωm) and the rock avalanche deposit (30-80 ωm). the interpreted thickness of the latter shows a strong variance of 5 to 30 m. profile p3 (fig. 7c) displays rock avalanche material with a maximal thickness of 10 m on top of two different bedrock lithologies (lavant fm. and allgäu fm.). like at p1, an uppermost high resistivity layer (200-550 ωm) occurs between profile metres 75 and 100 covering thicker rock avalanches deposits with (50-70 ωm). 4.3 area, volume and fahrböschung the mapped rock avalanche deposits cover an area of 2.7 km2. when considering the already eroded parts, an original area of c. 2.8 km2 seems to be reasonable, which is four times larger than the scarp area. the results of geological mapping and geoelectrical surveying (fig. 7) show varying rock avalanche deposit thicknesses of 2-60 m, respectively 5-40 m, and indicate that a precise estimate of the volume of the deposit is challenging. the most reliable approach is the estimate of volume based on the missing volume in the detachment niche. the scenario with a planar surface (fig. 8a) reveals 20x106 m3 whereas the more realistic one with a slightly convex surface (fig. 8b) results in 27x106 m3. this would correspond to an average 10 m thick rock avalanche deposit. however, an increase in volume of the deposit compared to the detached carbonate bedrock of 25-30% (abele, 1974; hungr & evans, 2004) due to the comminution process has to be considered, resulting in a calculated average thickness of c. 13 m. taking into account the modification of the scarp area due to small mass movements after the event, the most reliable estimate for the original maximum scarp altitude is c. 1850 m a.s.l. with the lowermost parts of the deposit at 650 m a.s.l., we have a drop height (h) of 1200 m. in combination with the runout length of the rock avalanche (l) of 3.5 km, the buchwiese rock avalanche has a fahrböschung α (after heim, 1932) of 19° and a h/l ratio of 0.36. in comparison, the average slope angle of the pathway is 16°. 4.4. age the results of the surface exposure dating with 36cl are shown in tab. 1. ages range from 9.8±0.5 ka (lienz 7) to 11.9±0.5 (lienz 5) (figs. 1, 5c, 6b). all four ages overlap within the given uncertainties. there is no spatial pattern with respect to the ages. the spread in ages may be attributable to processes that lead to too old ages, like inheritance, and too young ages, such as post-depositional movement of the boulder or spalling of the surface. as there is no independent means to estab 174 lish which ages are the true ages, we take an average of all four ages. the average age is 10.8±0.9 ka. the uncertainty on the mean reflects both the uncertainty on the individual ages and the spread in the ages. 5. discussion the legacy of the reconstructed buchwiese rock avalanche with an age of 10.8±0.9 ka reveals numerous morphological and sedimentary features that indicate control by both the lithological distribution in the scarp area and the pathway morphology and geology. 5.1 geometry when comparing the geometry of the detachment area with that of the deposition area the fourfold areal extension (0.7 km2 vs. ~2.8 km2) of the latter is evident. this is overwhelmingly the result of an extension in the longitudinal (runout) direction (0.9 m vs. c. 3 km) and not that of a widening (0.8 km vs 1.2 km). in general, such a geometry of the rock avalanche displays the morphological conditions along the pathway with a slope allowing unconfined flow and the absence of a major obstacle with the exception of the bedrock ridge at kreithof in the middle part (figs. 1, 3). the early holocene age provides a reasonable explanation of the sharp limit between the most distal part of the rock avalanche and the alluvial deposits of the river drau. considering the reconstructed progradation phases of an alluvial fan just 4 km down-valley (patzelt & poscher, 1995), the modern valley floor of the river drau seems to have been in an aggradational phase since the younger dryas (12.8-11.7 ka) with only lateral erosion of the originally meandering river drau (burschil et al., fig. 7 the results of the geoelectrical survey at profile p1, p2 and p3 (for location see figs. 1, 5). note the colour bar for restivity of p1 is different from p2 and p3. reitner j.m. et al. 2019). thus, any remnants of the rock avalanche north of the current limit, if they ever existed, must have been reworked. the presence of a thick layer of buchwiese rock avalanche deposits in the centre of the valley can be ruled out (burschil et al., 2019). a limited amount of uncertainty exists regarding the extension in two cases. the fan-like structure of the partly reworked deposit south of kreithof could potentially indicate a branch towards the east. however, no further traces of the rock avalanche have been found in the catchment of the eastward draining creek. the other case concerns the relation between the rock avalanche deposit on the northwestern limits and the lake tristach basin. the latter is the result of subglacial shaping. alluvial fans nowadays constrain the eastern limit of the lake. however, a further extension of this small basin and maybe the lake towards the east, in the range of few hundred metres, into the area now covered by the alluvial fans and parts of the rock avalanche seems to be likely. thus, a subordinate branch of the buchwiese rock avalanche flowing towards the west into the area now covered by the modern lake tristach cannot be ruled out without limnogeological investigations. 5.2. morphology, lithological distribution and facies ridges within the rock avalanche deposit are the most evident morphological indicators of fluid-like runout motion. all mapped features in the study area are best interpreted as longitudinal ridges (dufresne & davies, 2008). the most prominent one in terms of length and height occurs in deposition area a with the lienz 5 boulder on top (fig. 1). according to the lithology of the boulders (massive limestone from oberrhätkalk) its formation started already after around 600 m. the same lithology is evident at ridge at c-4 in the lowermost deposition area c. smaller ridges consist of kössen limestone. considering the topographic conditions enabling unhindered spreading, the presence of ridges in the case of the buchwiese rock avalanche seems to be linked to the availability of sufficient mechanically competent material (dufresne & davies, 2009) such as limestone. in contrast, the less competent materials of the kössen fm. (marl, claystone) were not able to form such ridges. this lithological control is also evident in the facies of the deposits. the occurrence of a blocky, clastsupported carapace facies overlying a body facies (dunning, 2004; weidinger et al., 2014; dufresne et al., 2016a) is a common feature in rock avalanche deposits (e.g. dufresne et al., 2016b; reitner et al., 2018; singeisen et al., 2020). such a carapace facies is only present at the ridges and in other limited areas where limestone especially the massive oberrhätkalk occurs, e.g. in the megaboulder cluster. despite the absence of large outcrops, which would allow tracing the changes of facies and fragmentation with depth, the available outcrop and geoelectrical data show in general the typical succession of a rock avalanche: below a carapace facies, if present, clast-supported diamictons (a-1 in fig. 4e) occur which resemble the blocky facies of dufresne et al. (2016a). outcrops of the interior in the deposition areas a and b consist mostly of strongly fragmented rock (outcrops a-2 and b-1 in figs. 4e, g, h) which represent the jigsaw subfacies of dufresne et al (2016a). in comparison, the occurrence of matrixsupported diamicton, the fragmented subfacies appears to be limited (e.g. lower part of outcrop a-2; fig. 4f). the rare outcrops of the deeper part of deposition area c only show the fragmented subfacies. geophysical data (in fig.7) also display the different amounts of fragmentation. the carapace facies in p1 (megaboulder cluster) and p3 is easy to identify. however, an absolute quantification of the degree of fragmentation via the resistivity values (in ωm) seems to be problematic due to the lithological variations of the fragmented source rocks within the profiles. the megaboulder cluster represents within the distal deposition area c, an outstanding and rather isolated feature. it is the largest coherent area with carapace facies comprising some oberrhätkalk limestone boulders of enormous size of up to 1000 m3. the fanshaped distribution with an apex just below the western edge of the kreithof oberrhätkalk bedrock ridge provides a clue for the provenance of the megaboulders. according to the most likely scenario, the western part of the glacially shaped bedrock ridge was impacted and eventually detached by the rock avalanche. the fan-like distribution and limited fragmentation as shown by the carapace facies support this suspected style of formation. excluding the megaboulder cluster, the distribution of lithologies within the rock avalanche deposit mirrors the sedimentary succession in the detachment area, with the clasts of the rotkalk and allgäu fm. in the most 175 fig. 8 reconstructed paleo-topographies of the scarp area for volume calculations of the detached mass. a) the scenario with a planar surface reveals 20x106 m3 b) the scenario with a slightly convex surface results in 27x106 m3. the early holocene buchwiese rock avalanche distal part. as in other cases (heim, 1932; strom, 2006; hewitt et al., 2008; dufresne et al., 2016a, b; rossato et al., 2020a), the preserved source stratigraphy within the dilated rock mass is a clear argument for a predominantly laminar style of rock avalanche movement. 5.3 the age, chronology of failure, kinematics, and its implications the age of the buchwiese rock avalanche of 10.8±0.9 ka, based on averaging of all four boulder ages, is in accordance with the superposition of the deposit on top of lateglacial delta deposits (phase of ice-decay, reitner et al., 2016) and the evident rounding of the boulders due to carbonate dissolution since deposition. the age also shows that the rock slope failure occurred 8-9 ka after the last glacial shaping and oversteepening of the slope during the lgm. the weakest lithology in the source area are the marls and claystones, i.e. the slaking rocks of the kössen fm. fatigue of this material over some thousand years together with the general dip-slope situation are regarded as the main cause for the slope failure and the detachment of a rock mass as a translational slide (cruden & varnes, 1996) or rock planar slide (hungr et al., 2014). nne-ssw trending faults facilitated the formation of the niche which finally developed with a mostly plane sliding surface (fig. 3), which also cut through the competent oberrhätkalk as well as the allgäu fm. tension gaps, which are still present in the stable margin, most likely were the precursors of the slope failure. in such a setting with alternations of fine-grained aquicludes and fractured aquifer within brittle limestone (probst et al., 2003), variations in the hydrostatic pressure over time were likely an additional driver for the slope failure. currently there is no indication of a trigger like a paleo-earthquake documented in other archives nearby. in addition, the regional seismicity is low (reiter et al., 2018). the slope failure occurred during the preboreal, a stage known for a considerable warming trend and its dryness (schmidt et al., 2006; magny et al., 2007; ilyashuk et al., 2011), which makes in general a higher wetness associated with high hydrostatic pressure in the jointed rocks as a cause / trigger unlikely. nevertheless, magny (2004) reported evidence of a distinctly wetter phase with higher lake-levels in central europe at 10.3-10.0 ka, which does overlap with the buchwiese failure event within the given error range. when comparing the altitude of the source area with the known spatial development in the region (steinemann et al., 2020), permafrost could have occurred for the last time during the younger dryas. permafrost degradation associated with the marked warming around 10.5 ka (ivyochs et al., 2009; protin et al., 2019) may have contributed to the weakening of the slope (krautblatter et al., 2013) as well. in such a geological setting, the detachment occurred in the initial phase as a translational slide. the onset of the first ridge after a travel distance of approx. 600 m shows a nearly instantaneous fragmentation leading to the typical fluid-like behaviour of a rock avalanche. such a strong fragmentation is especially evident in the brittle limestone. in comparison, large out 176 crops of kössen fm. debris upstream of the kreithof ridge with a comparable moderate fragmentation in the middle part of the flow, may indicate a longer sliding phase within this lithology due to the preferential deformation of the weak claystone layers. the pathway shows a slight bending nne to ne at the south-eastern flank of the rauchkofel peak. such a flowline could have been predetermined to some extent by preexisting paleo-valleys. after this, the strongest interference with topography occurred by the collision with at least parts of the western limestone ridge extension at kreithof (fig. 5). on the one hand, this development led to the formation of the megaboulder cluster. due to the break in slope a jump of less than 200 m could have occurred. on the other hand, the rock avalanche smoothed the glacially shaped topography south of the glacially moulded bedrock ridge which explains the greatest thickness in this area (fig. 3). after the assumed short-distance jump, the rockavalanche moved with more or less the same width leading to further fragmentation. the patchy coverage in the areas close to the alluvial deposits of the river drau together with a thinning of the rock avalanche cover indicate the final run-out. the facies and the morphology of the deposits are in accordance with the hypotheses of dynamic fragmentation (mcsaveney & davies, 2006; davies & mcsaveney, 2009) as the main mechanical reason for reducing the internal friction of the moving mass and, eventually, the long run-out. 5.4 comparison with other catastrophic slope failures the buchwiese is one of the rare cases of an unconfined rock avalanche which remained on the slope and did not reach the valley floor. most of the rock avalanches discussed in recent years are characterised either by events which hit the valley floor or had interactions with valley flanks (e.g. hewitt et al., 2008; ostermann et al., 2012; grämiger et al., 2016; ivy-ochs et al., 2017). hence comparison with respect to the kinematics and the influence of topographic obstacles and constraints is not an easy task. based on available data under dip-slope conditions, the kössen fm. tends to fail as slides or relatively slow flows or a combination of these (nickmann, 2009; nickmann & thuro, 2013; lotter & gruber, 2020). in cases with a dip much steeper than the slope, catastrophic rock slides are known, like the two cases (mordbichl, lienzer klause) from the northwestern flank of lienz dolomites in the upper drau valley (puster valley; reitner, 2003a, 2016; linner et al., 2013). such a tectonic setting, different from the buchwiese scarp area, may explain the formation of a listric sliding plane, independent of the bedding in the cases of puster valley. in general, the lienz dolomites, despite their high relief, do not have an abundance of catastrophic rock slope failures. beside the buchwiese and the two rockslides (mordbichl, lienzer klause) with a late holocene age, only the laserz rock avalanche consisting of fragmented dolostone occurred during a younger dryas glacier advance (reitner et al., 2014). within a distance of 25 km there are only two additional cases within crys reitner j.m. et al. talline tectonic units, feld near matrei (reuther et al., 2006) and kals (veit, 1988), which are altogether not linked to one tectonic system as has been noted at other sites (brenner cluster ostermann & sanders, 2017; piave valley rossato et al., 2020b). there has been some discussion of a temporal cluster of large landslides in the alps during the early holocene, which comprised the kandersteg, flims and koefels events (ivy-ochs et al., 2017 and references therein). indeed, the recently presented 36cl exposure age, 3.2±0.2 ka, for the kandersteg event (1.1 km3) weaken this conjecture as the kandersteg event occurred during the late and not the early holocene (singeisen et al., 2020). by comparing the buchwiese age of 10.8±0.9 ka with other dated events in the alps it is evident that dated early holocene catastrophic rock slope failure are rare when comparing with the available records (prager et al., 2008; ivy-ochs et al., 2017). the two largest events in the alps, flims (10-12 km3) and köfels (3 km3) with ages of 9.4 ka (von poschinger & haas, 1997) and 9.5 ka (nicolussi et al., 2015), overlap with the buchwiese event within the age uncertainties. nevertheless, the fact that the sites are distant from each other makes implicating a seismic trigger difficult. the strongest age overlap is with the rather small lenzanger rock avalanche (10.8±1.1 ka) in the hohen tauern mountain range. those deposits overlie both a younger dryas till and the durchgangwald rockslide deposits (12.6±1.0 ka; bichler et al., 2016). the marked warming around 10.5 ka in the alps, expressed as retreat of glaciers back to as small as or smaller than their little ice age extents (schimmelpfennig et al., 2012; protin et al., 2019) and especially as permafrost degradation, may have been the critical factor that led to slope failure at buchwiese. nevertheless, the release area itself is not in an area occupied by a glacier during the younger dryas (reitner et al., 2016). 6. conclusions we present reconstruction of the buchwiese rock avalanche based on geological field mapping, analysis of dem data, 36cl exposure dating, and a geoelectrical survey. based on the results of the 36cl exposure dating, the event took place at 10.8±0.9 ka during the early holocene and, thus, 8-9 ka after the last glacial shaping and oversteepening of the slope during the lgm. the age is the average of all four obtained boulder ages. the failure of a rock mass with a volume of 27x106 m3 was enabled by dip-slope sliding within strata of the kössen fm. (limestone, marls, claystone), oberrhätkalk (massive to thickly bedded limestone), and rotkalk (red nodular limestone and marl) dipping to the north in combination with n-s to nne-ssw running brittle faults. weak layers in the fine-grained rocks of the kössen fm. (claystone, marl) are the major lithological precondition for the mass movement. we consider fatigue of such slaking rocks since the lgm as the major cause for this catastrophic rock slope failure. according to the geological conditions, the initial failure occurred as a translational slide with a mostly plane sliding surface. in the deposition area, strong control of lithology and topography on the development of different facies and morphological features is evident: 1. longitudinal ridges indicate spreading of an unconfined flow. the onset of the first longitudinal ridges shows a strong fragmentation resulting in fluid-like movement after only 600 m of transport. the most prominent ridges with respect to height and length consist of the massive oberrhätkalk. smaller ridges are developed in kössen limestone whereas the other lithologies were not able to form ridges. 2. the carapace facies consisting of clast-supported boulders is only developed in areas with limestone (mostly oberrhätkalk but also limestone of the kössen fm.). 3. the body facies in the upper parts (deposition area a) are dominated by the jigsaw subfacies with a subordinate occurrence of fragmented subfacies in the outcrops. even in the middle part (area b) the prevalence of the moderately fragmented jigsaw subfacies within large soutcrops of kössen fm. consisting of alternating claystone, limestone beds is evident. this may indicate preferential deformation within the claystone beds. 4. after partial collision with a bedrock ridge consisting of massive oberrhätkalk limestone and a small jump, the fragmented facies dominates. 5. this collision led to the formation of megaboulder cluster consisting of detached and fragmented oberrhätkalk boulders with volumes of up to 1000 m3 and a fan-like distribution. the preserved source stratigraphy within the dilated rock mass is a clear argument for a predominantly laminar style of rock avalanche movement. this finding, together with the presence of longitudinal ridges indicating fluidisation, as well as the facies distribution, support the dynamic fragmentation model (mcsaveney & davies, 2006; davies & mcsaveney, 2009) as the best mechanical explanation for the buchwiese rock avalanche. acknowledgements comments provided by jeff moore and an anonymous reviewer helped us to improve the paper. we are grateful for the help of hanns kerschner during sampling in november 2007. discussions with bernd imre in 2011 in the field and with michael lotter and marc ostermann at the geological survey of austria were helpful in refining the interpretation of fragmentation and mechanics. ruth drescher-schneider provided valuable information on the paleoclimatic conditions. we would also like to thank stefanie gruber, stefan pfeiler, ivo baron and anna zöchbauer for support at the geophysical survey, and the accelerator mass spectrometry group at ion beam physics eth zurich and especially to vasily alfimov for ams 36cl measurements. references aaron j., mcdougall s. (2019) rock avalanche mobility: the role of path material. engineering geology, 257, 105126. aaron j., wolter a., loew s., volken s. (2020) understanding failure and runout mechanisms of the 177 the early holocene buchwiese rock avalanche flims rockslide/rock avalanche. frontiers in earth science, 8, 224, 1-19. abele g. (1974) bergstürze in den alpen, ihre verbreitung, morphologie und folgeerscheinungen. wissenschaftliche alpenvereinshefte, 25, 230. alfimov v., ivy-ochs s. (2009) how well do we understand production of 36cl in limestone and dolomite?. quaternary geochronology, 4(6), 462-474. aizebeokhai a.p. (2010) 2d and 3d geoelectrical resistivity imaging: theory and field design, scientific research and essay, 5(23), 3592-3605. andré m.f. (2002) rates of postglacial rock weathering on glacially scoured outcrops (abiskoriksgränsen area, 68° n). geografiska annaler: series a, physical geography, 84(3-4), 139-150. bauer w. (1990) geologische kartierung in den nordöstlichen lienzer dolomiten (tirol). master thesis (diplomarbeit), rheinland westfälische technische hochschule aachen. bichler m.g., reindl m., reitner j.m., drescherschneider r., wirsig c., christl m., hajdas i., ivyochs s. (2016) landslide deposits as stratigraphical markers for a sequence-based glacial stratigraphy: a case study of a younger dryas system in the eastern alps. boreas, 45, 537-551. blau j., grün b. (1995) jura und kreide in der amlacher wiesen-mulde (nördliche lienzer dolomiten). arbeitstagung der geologischen bundesanstalt. geologie von osttirol, lienz, 43-66, geologische bundesanstalt, vienna. brandner r., gruber a., prager c., lutz d., ortner h. (2001) regional extension between meso-alpine and neo-alpine compressional structural systems north and south of the periadriatic lineament (lienz dolomites and eastern southern alps). geologischpaläontologische mitteilungen. lnnsbruck, 25, 52-54. burschil t., tanner d.c., reitner j.m., buness h., gabriel g. (2019) unravelling the shape and stratigraphy of a glacially-overdeepened valley with reflection seismic: the lienz basin (austria). swiss journal of geosciences, 112(2-3), 341-355. christl m., vockenhuber c., kubik p.w., wacker l., lachner j., alfimov v., synal h.a. (2013) the eth zurich ams facilities: performance parameters and reference materials. nuclear instruments and methods in physics research section b: beam interactions with materials and atoms, 294, 29-38. crosta g.b., frattini p., fusi n. (2007) fragmentation in the val pola rock avalanche, italian alps. journal of geophysical research: earth surface, 112(f1). cruden d.m., varnes d.j. (1996) landslides: investigation and mitigation. chapter 3-landslide types and processes. transportation research board special report, 247, 36-75. dahlin t., bing z. (2006) multiple-gradient array measurements for multichannel 2d resistivity imaging, near surface geophysics, 4(2), 113-123. davies t.r., mcsaveney m.j. (2009) the role of rock fragmentation in the motion of large landslides. engineering geology, 109(1), 67-79. dufresne a., davies t.r. (2009) longitudinal ridges in mass movement deposits. geomorphology, 105(34), 171-181. 178 dufresne a., bösmeier a., prager c. (2016a) sedimentology of rock avalanche deposits-case study and review. earth-science reviews, 163, 234-259. dufresne a., prager c., bösmeier a. (2016b) insights into rock avalanche emplacement processes from detailed morpho�lithological studies of the tschirgant deposit (tyrol, austria). earth surface processes and landforms, 41(5), 587-602. dufresne a., dunning s.a. (2017) process dependence of grain size distributions in rock avalanche deposits. landslides, 14(5), 1555-1563. dunning s.a. (2004) rock avalanches in high mountains-a sedimentological approach. unpublished phd thesis university of luton, uk. eisbacher g.h., clague j.j. (1984) destructive mass movements in high mountains: hazard and management, geological survey of canada, vancouver, british columbia, canada. erismann t.h., abele g. (2001) dynamics of rockslides and rockfalls. springer-verlag berlin heidelberg, germany. grämiger l.m., moore j.r., vockenhuber c., aaron j., hajdas i., ivy-ochs s. (2016) two early holocene rock avalanches in the bernese alps (rinderhorn, switzerland). geomorphology, 268, 207-221. heim a. (1932) bergsturz und menschenleben, vierteljahrsschrift der naturforschenden gesellschaft in zürich, 20, beer & co., zürich. hewitt k., clague j.j., orwin j.f. (2008) legacies of catastrophic rock slope failures in mountain landscapes. earth-science reviews, 87(1-2), 1-38. hungr o., evans s.g. (2004) entrainment of debris in rock avalanches: an analysis of a long run-out mechanism. geological society of america bulletin, 116(9-10), 1240-1252. hungr o., corominas j., eberhardt e. (2005) estimating landslide motion mechanism, travel distance and velocity. in landslide risk management (pp. 109138). crc press. hungr o., leroueil s., picarelli l. (2014) the varnes classification of landslide types, an update. landslides, 11(2), 167-194. ilyashuk e.a., koinig k.a., heiri o., ilyashuk b.p., psenner r. (2011) holocene temperature variations at a high-altitude site in the eastern alps: a chironomid record from schwarzsee ob sölden, austria. quaternary science reviews, 30(1-2), 176191. imre b., laue j., springman s.m. (2010) fractal fragmentation of rocks within sturzstroms: insight derived from physical experiments within the eth geotechnical drum centrifuge. granular matter, 12 (3), 267-285. ivy-ochs s., synal h. a., roth c., schaller m. (2004) initial results from isotope dilution for cl and 36cl measurements at the psi/eth zurich ams facility. nuclear instruments and methods in physics research section b: beam interactions with materials and atoms, 223, 623-627. ivy-ochs s., kober f. (2008) surface exposure dating with cosmogenic nuclides. e&g quaternary science journal, 57(1-2), 179-209. ivy-ochs s., kerschner h., maisch m., christl m., kubik reitner j.m. et al. p.w., schlüchter c. (2009) latest pleistocene and holocene glacier variations in the european alps. quaternary science reviews, 28(21), 21372149. ivy-ochs s. (2015) glacier variations in the european alps at the end of the last glaciation. cuadernos de investigación geográfica/geographical research letters, 41(2), 295-315. ivy-ochs s., martin s., campedel p., hippe k., alfimov v., vockenhuber c., andreotti e., carugati g., pasqual d., rigo m,. viganò a. (2017) geomorphology and age of the marocche di dro rock avalanches (trentino, italy). quaternary science reviews, 169, 188-205. keller b. (1996) lithofazies-codes für die klassifikation von lockergesteinen. mitteilungen der schweizerischen gesellschaft für bodenund felsmechanik, 132, 5-12. krautblatter m., funk d., günzel f.k. (2013) why permafrost rocks become unstable: a rock-ice� mechanical model in time and space. earth surface processes and landforms, 38(8), 876-887. linner m., reitner j.m., pavlik w. (2013) geologische karte der republik österreich 1:50.000 blatt 179 lienz. geologische bundesanstalt, vienna. loke m.h. (2019) geoelectrical imaging 2-d & 3-d, manual, geotomo software, malaysia. loke m.h., chambers j.e., rucker d.f., kuras o., wilkinson p.b. (2013) recent developments in the direct-current geoelectrical imaging method, journal of applied geophysics, 95, 135-156. lotter m., gruber a. (2020) ingenieurgeologie geogene naturgefahren. in: gruber a., lotter m., brandner r. (eds.): erläuterungen zur geologischen karte der republik österreich 1:50.000, blatt 88 achenkirch, 200-230, geologische bundesanstalt, vienna. magny m. (2004) holocene climate variability as reflected by mid-european lake-level fluctuations and its probable impact on prehistoric human settlements. quaternary international, 113(1), 65-79. magny m., vannière b., de beaulieu j.l., bégeot c., heiri o., millet l., peyron o., walter-simonnet a.v. (2007) early-holocene climatic oscillations recorded by lake-level fluctuations in west-central europe and in central italy. quaternary science reviews, 26 (15), 1951-1964. mcsaveney m.j., davies t. (2006) inferences from the morphology and internal structure of rockslides and rock avalanches rapid rock mass flow with dynamic fragmentation. in: evans g. e., mugnozza g. s., storm a. hermanns r. l.(eds.): landslides from massive rock slope failure, 285-304, springer, dodrecht. monegato g., ravazzi c., donegana m., pini r., calderoni g., wick l. (2007) evidence of a twofold glacial advance during the last glacial maximum in the tagliamento end moraine system (eastern alps). quaternary research, 68(2), 284-302. nickmann m. (2009) abgrenzung und klassifizierung veränderlich fester gesteine unter ingenieurgeologischen aspekten. münchner geowissenschaftliche abhandlungen, reihe b, band 12, verlag dr. friedrich pfeil, münchen. nickmann m., thuro k. (2013) die veränderlich festen mergelsteine der kössen-formation als schlüsselhorizonte für hangbewegungen im spitzingseegebiet (nördliche kalkalpen). 19. tagung für ingenieurgeologie mit forum für junge ingenieurgeologen, münchen 2013, 229-234. nicolussi k., spötl c., thurner a., reimer p.j. (2015) precise radiocarbon dating of the giant köfels landslide (eastern alps, austria). geomorphology, 243, 87-91. ostermann m., sanders d. (2017) the benner pass rock avalanche cluster suggests a close relation between long-term slope deformation (dsgsds and translational rock slides) and catastrophic failure. geomorphology, 289, 44-59. ostermann m., sanders d., prager c., kramers j. (2007) aragonite and calcite cementation in “boulder-controlled” meteoric environments on the fern pass rockslide (austria): implications for radiometric age dating of catastrophic mass movements. facies, 53(2), 189-208. ostermann m., sanders d., ivy-ochs s., alfimov v., rockenschaub m., römer a. (2012) early holocene (8.6 ka) rock avalanche deposits, obernberg valley (eastern alps): landform interpretation and kinematics of rapid mass movement, geomorphology, 171-172, 83-93. ostermann m., ivy�ochs s., sanders d., prager c. (2017) multi�method (14c, 36cl, 234u/230th) age bracketing of the tschirgant rock avalanche (eastern alps): implications for absolute dating of catastrophic mass�wasting. earth surface processes and landforms, 42(7), 1110-1118. pánek t. (2019) landslides and quaternary climate changes the state of the art. earth-science reviews, 196, 102871. doi: 10.1016/j.earscirev.2019.05.015 patzelt g., poscher g. (1995) neue ergebnisse zur quartärgeologie osttirols: fazies und sedimentations-geschichte des frauenbach-schwemmfächers bei lavant. arbeitstagung der geologischen bundesanstalt. geologie von osttirol, lienz, 67-73, geologische bundesanstalt, vienna. perrone a., iannuzzi a., lapenna v., lorenzo p., piscitelli s., rizzo e. (2004) high-resolution electrical imaging of the varco d’izzo earthflow (southern italy), journal of applied geophysics 56(1), 17-29. prager c., zangerl c., patzelt g., brandner r. (2008) age distribution of fossil landslides in the tyrol (austria) and its surrounding areas. natural hazards and earth system sciences, 8(2), 377-407. prager c., ivy-ochs s., ostermann m., synal h.a., patzelt g. (2009) geology and radiometric 14c-, 36cl-and th-/u-dating of the fernpass rockslide (tyrol, austria). geomorphology, 103(1), 93-103. probst g., brandner r., hacker p., heiss g., prager c. (2003) hyrogeologische grundlagenstudie westliche gailtaler alpen/lienzer dolomiten (kärnten/ osttirol). steirische beiträge zur hydrogeologie, 54, 5-62. protin m., schimmelpfennig i., mugnier j.l., ravanel l., le roy m., deline p., favier v., buoncristiani j.-f., 179 the early holocene buchwiese rock avalanche aumaître g., bourlès d.l., keddadouche k. (2019) climatic reconstruction for the younger dryas/early holocene transition and the little ice age based on paleo-extents of argentière glacier (french alps). quaternary science reviews, 221, 105863. doi: 10.1016/j.quascirev.2019.105863 reitner j.m. (2016) bericht 2001-2003 über geologische aufnahmen im quartär auf blatt 179 lienz und blatt 178 hopfgarten in defereggen. jahrbuch der geologischen bundesanstalt, 156, 289-292. reitner j.m. (2003a) bericht 2000 über geologische aufnahmen im quartär auf blatt 179 lienz. jahrbuch der geologischen bundesanstalt, 143, 391397. reitner j.m. (2003b) bericht 1998-99 über geologische aufnahmen im quartär und kristallin auf blatt 179 lienz. jahrbuch der geologischen bundesanstalt, 143, 514-522. reitner j.m., linner m. (2009) formation and preservation of large scale toppling related to alpine tectonic structures, eastern alps. austrian journal of earth sciences, 102(2), 69-80. reitner j.m., ivy-ochs s., hajdas i., lattner d. (2014) bergstürze in den lienzer dolomiten vom würmspätglazial bis in das jüngste holozän. in: koinig k.a., starnberger r., spötl, c. (eds.): deuqua 2014: 37. hauptversammlung der deutschen quartärvereinigung innsbruck 2014, 24-29 september, abstractband 96, innsbruck (innsbruck university press). reiter f., freudenthaler c., hausmann h., ortner h., lenhardt w., brandner r. (2018) active seismotectonic deformation in front of the dolomites indenter, eastern alps. tectonics, 37(12), 4625-4654. reitner j.m., ivy-ochs s., drescher-schneider r., hajdas i., linner m. (2016) reconsidering the current stratigraphy of the alpine lateglacial: implications of the sedimentary and morphological record of the lienz area (tyrol/austria). e & g quaternary science journal, 65(2), 113-144. reitner j.m., ostermann m., schuster r., bichler m.g., knoll t., robl j., ivy-ochs s. (2018) der bergsturz vom auernig (mallnitz/kärnten), seine altersstellung und folgen. carinthia ll, 208(128), 503-548. reitner j.m., menzies j. (2020) microsedimentology of tills near ainet, austria-were palaeo-ice streams in the european alps underlain by soft deforming bed zones?. austrian journal of earth sciences, 113(1), 71-86. reuther a.u., reitner j.m., ivy-ochs s., herbst, p. (2006) from kinematics to dating the sturzstrom deposit of feld (matrei/eastern tyrol/austria). geophys. res. abstr. 8, 04947. rossato s., ivy-ochs s., martin s., viganò a., vockenhuber c., rigo m., monegato g., zorzi m.d., surian n., campedel p., mozzi p. (2020a) timing, drivers and impacts of the historic masiere di vedana rock avalanche (belluno dolomites, ne italy). natural hazards and earth system sciences, 20, 2157-2174. rossato s., ghirotti m., gabrieli f., livio f., bovo f., brezzi l., campedel p., cola s., ivy-ochs s., martin s., mozzi p., pasuto a., rigo m., simonini p., suri 180 an n., viganò a., vockenhuber c., wolter a. (2020b) learning from the past to face the future: landslides in the piave valley (eastern alps, italy). alpine and mediterranean quaternary, 33, 2, 209228. doi: 10.26382/amq.2020.14 schmidt r., van der bogaard c., merkt j., müller j. (2002) a new lateglacial chronostratigraphic tephra marker for the southeastern alps: the neapolitan yellow tuff (nyt) in längsee (austria) in the context of a regional biostratigraphy and paleoclimate. quaternary international, 88(1), 45-56. schmidt r., kamenik c., tessadri r., koinig k.a. (2006) climatic changes from 12,000 to 4,000 years ago in the austrian central alps tracked by sedimentological and biological proxies of a lake sediment core. journal of paleolimnology, 35(3), 491-505. schmid s.m., fügenschuh b., kissling e., schuster r. (2004) tectonic map and overall architecture of the alpine orogen. eclogae geologicae helvetiae, 97(1), 93-117. schmidt t. (1995) zur tektonik der lienzer dolomiten. arbeitstagung der geologischen bundesanstalt. geologie von osttirol, lienz, 37-42, geologische bundesanstalt, vienna. schimmelpfennig i., schaefer j.m., akçar n., ivy-ochs s., finkel r.c., schlüchter c. (2012) holocene glacier culminations in the western alps and their hemispheric relevance. geology, 40(10), 891-894. schuster r., daurer a., krenmayr h.g., linner m., mandl g.w., pestal g., reitner j.m. (2014) rocky austria; the geology of austria brief and colourful. geologische bundesanstalt, vienna. singeisen c., ivy-ochs s., wolter a., steinemann o., akçar n., yesilyurt s., vockenhuber c. (2020) the kandersteg rock avalanche (switzerland): integrated analysis of a late holocene catastrophic event. landslides, 17, 1297-1317. steinemann o., reitner j.m., ivy-ochs s., christl m., synal h.a. (2020) tracking rockglacier evolution in the eastern alps from the lateglacial to the early holocene. quaternary science reviews, 241, 106424. doi: 10.1016/j.quascirev.2020.106424 strom a. (2006) morphology and internal structure of rockslides and rock avalanches: grounds and constraints for their modelling. in landslides from massive rock slope failure, 305-326. springer, dordrecht. van husen d. (2000) geological processes during the quaternary. mitteilungen der österreichischen geologischen gesellschaft, 92(1999), 135-156. veit h. (1988) fluviale und solifluidale morphodynamik des spätund postglazials in einem zentralalpinen flusseinzugsgebiet (südliche hohe tauern, osttirol). bayreuther geowissenschaftliche arbeiten, 13, 1-167. vockenhuber c., miltenberger k.u., synal h.a. (2019) 36cl measurements with a gas-filled magnet at 6 mv. nuclear instruments and methods in physics research section b: beam interactions with materials and atoms, 455, 190-194. reitner j.m. et al. von poschinger a., haas u. (1997) der flimser bergsturz, doch ein warmzeitliches ereignis?. bulletin für angewandte geologie, 2(1), 35-46. weidinger j.t., korup o., munack h., altenberger u., dunning s.a., tippelt g., lottermoser w. (2014) giant rockslides from the inside. earth and planetary science letters, 389, 62-73. wood j.l., harrison s., reinhardt l. (2015) landslide inventories for climate impacts research in the european alps. geomorphology, 228, 398-408. zerathe s., lebourg t., braucher r., bourlès d. (2014) mid-holocene cluster of large-scale landslides revealed in the southwestern alps by 36cl dating. insight on an alpine-scale landslide activity. quaternary science reviews, 90, 106-127 ms. received: august 25, 2020 revised: october 28, 2020 accepted: december 2, 2020 available online: december 20, 2020 181 the early holocene buchwiese rock avalanche 182 available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 39 42 icno-archeology of a human palaeolithic ecosystem: the human and animal footprints in the grotta della basura (toirano, northern italy) marco avanzini 1 , marco romano 2 , paolo citton 3 , isabella salvador 1 , daniele arobba 4 , rosanna caramiello 4 , marco firpo 5 , ivano rellini 5 , fabio negrino 6 , livia clementi 6 , marta zunino 7 , stefano giannotti 7 , elisabetta starnini 8 , marta conventi 9 1 muse, museo delle scienze, trento, italy 2 evolutionary studies institute (esi), school of geosciences, university of the witwatersrand, johannesburg, south africa 3 instituto de investigación en paleobiología y geología, universidad nacional de río negro, río negro province, argentina 4 museo archeologico del finale, finale ligure borgo (savona), italy 5 dipartimento di scienze della terra, dell’ambiente e della vita (distav), università degli studi di genova, genova, italy 6 dipartimento di antichità, filosofia, storia (dafist), università degli studi di genova, genova, italy 7 grotte di toirano, toirano (savona), italy 8 dipartimento di civiltà e forme del sapere, università di pisa, pisa, italy 9 soprintendenza archeologia belle arti e paesaggio of liguria, genua, italy corresponding author: m. avanzini <marco.avanzini@muse.it> abstract: the footprints of human and animal trackmakers, which around 12,000 years b.p. attended the cave of básura (toirano, liguria, northern italy), were studied through morpho-classificatory and morphometric approaches. first results indicate at least three different human producers, two youths and the third of tender age, bears and wolves (or dogs). analysis of the data demonstrate the power of 3d, of landmark based morphometrics and the utility to use the methods of forensic anthropology in the determination of human footprints. the analysis of the number of trackmakers using the pca analysis on 'multi-trampling' surfaces could represent a model in the study of cave sites. key words: ichnology, cave, upper palaeolithic, human footprints, bear footprints 1. introduction the cave of bàsura (grotta della bàsura), opening at 186 m above sea level (a.s.l.) at the foot of mount carmo in loano (toirano, savona), is known by the 1890, when nicolò morelli highlighted the occurrence of some evidence dating back to the neolithic and late roman period in the outermost portion of the cave. in 1950, the inner rooms of the cave were discovered. soon after, the outstanding evidence of human frequentation, in addition to remains of ursus spelaeus, were brought into the limelight of the italian palaeontological and palaeoanthropological research by virginia chiappella (1952, 1955). in 2014, the “soprintendenza archeologia belle arti e paesaggio per la città metropolitana di genova e le province di imperia, la spezia e savona genova”, promoted and initiated a new multidisciplinary project on the cave. the project is aimed at better understanding and integration of many different data, also consisting of tracks and traces attributable to bears and canids tracks, as well as other traces of different human activities (e.g. footprints, carbons, digital tracks, lumps of clay adhering to the walls). 2. material and methods the substrate of the cavity preserves in many sectors numerous traces with different degree of conservation. most of them are concretioned, differently others are imprinted on a still plastic substrate. recent radiometric datings (2017) confirm the attendance of the cavity in the upper paleolithic at 14420 bp c.a. in the innermost room (i.e. sala dei misteri) where the study was concluded (citton et al., 2017) 54 track and traces were detected among which 35 human footprints and 6 bear footprints (fig.1). numerous other traces are preserved in other portions of the cave and are currently under investigation using new cutting-edge methodology such as high resolution 3d modelling and morphometric analyses. the material under examination comprises a substantial number of human footprints referable to individuals of different gender and age classes, footprint referable to bears (very likely ursus arctos) and footprints left by canids (wolves or dogs). the main sectors of the cave were digitally acquired via laser scanner leica scanstation c10. the scans were performed at 360° (acquisition grid of the point cloud of 2x2 cm probe 7 m and of 0.5x0.5 cm probe 7 m). the recording shows a final alignment error of 2 mm. schematic reliefs were derived from the model where the positions of each single studied footprints are showed. all tracks recognized were analyzed in the field using a classical morphological approach. each track was photographed and designed on site. the dimensional and morphological parameters collected in the field were https://doi.org/10.26382/aiqua.2018.aiquaconference double-checked, using photos and photogrammetric models. the measurements of human footprints are based on both the landmark proposed by robbins (1985), and on studies following the forensics medicine methods. for all the studied footprints, a photogrammetric model was obtained using photos taken with a 24 megapixel canon eos 750d (18 mm focal length). the software used to build the models in this paper is agisoft photoscan pro, (www.agisoft.com), among the most user-friendly programs for photogrammetry’ (mallison and wings, 2014). the accuracy of the obtained models is up to 1 mm for close-range photography (fig. 2). the 13 best-preserved human and animal (canids) footprints, were subject to a principal component analysis (pca). for the analysis, the software past 3.10 was used (hammer et al., 2001). for the correspondence of the log-transform to an isometric null hypothesis and to fit linear models the raw data were logtransformed (see chinnery, 2004; cheng et al., 2009; romano and citton, 2015, 2016). 3. results to date, a first ichnological analysis focused on about thirty footprints of human producers, attending the innermost areas of the cave (sala dei misteri), was carried out. by adopting a morpho-classificatory and morphometric approach applied to the best-preserved footprints, an estimation of the minimum number of trackmakers, as well as their age and height, was reached. the recognition of three well-separated morphotypes indicates a child under 5 years of age and two youth of 40 avanzini m. et al. fig. 1 human footprints, bear footprints and human traces preserved in the 'sala dei misteri' in the grotta della basura sm1, sm6, sm15 human footprints; sm12 adult bear footprint; sm41 immature bear footprint; sm44 human finger traces. 41 6-7 and 11-12 years of age, respectively, as track producers (fig. 3). the ongoing analysis of human footprints, preserved in other areas of the cave, confirms the presence of the subjects identified in the sala dei misteri to which other individuals should be added after the new multidisciplinary analysis still in progress. the relationships between animal and human attendance of the hypogeal environment are currently being defined, even if from a preliminary analysis it seems that the human traces are successive to those of bear and antecedent or contemporary to those left by canids. 4. discussion and conclusion the work in progress in the grotta della bàsura confirms the great archaeological and palaeontological interest of this cavity within the european upper paleo ichno-archeology of the grotta della basura fig. 2 three-dimensional, false coloured photogrammetric models of selected tracks from ‘sala dei misteri in the grotta della basura. sm15) medium sized human footprint with well-developed concave plantar arch (morphotype 3); sm6) medium sized human footprint impressed in thin moist clay (morphotype 3); sm29-sm38) heel prints. lithic panorama. the strongly conservative environment has led to the preservation, on the same level, of a complex ichnological framework whose spatial and temporal relationships will be clarified by ongoing research. as already reported from different european caves, the currently obtained results enable to confirm that children, despite their apparent elusiveness in prehistoric archaeological contexts, were ubiquitous in daily life of the pleistocene populations, constituting a significant demographic component of upper paleolithic communities (see citton et al., 2017). the review of the complex ichnological record of the grotta della bàsura is currently underway and oriented at recognizing any relationships between the different producers that attended the cave, in order to gain a more complete frame of this ancient ecosystem. acknowledgements the authors are grateful to the responsible of the site fiorenzo panizza and the grotta della basura cave guides for logistic support during their stay in the cave. references cheng y.n., holmes r., wu x.c., alfonso n. (2009) sexual dimorphism and life history of keichosaurus hui (reptilia: sauropterygia). j. vertebrate paleontology 29, 401408. chiappella v.g. (1952) orsi e uomini preistorici nella grotta della strega. riv. del comune (genova), xxix, 4, 22 29. chiappella v.g. (1955) grotta della basura a toirano (savona). quaternaria, 2, 282 284. chinnery b. (2004) morphometric analysis of evolutionary trends in the ceratopsian postcranial skeleton. j. vertebrate paleontology, 24, 591609. citton p., romano m., salvador i., avanzini m. (2017) reviewing the upper pleistocene human footprints from the ‘sala dei misteri’in the grotta della bàsura (toirano, northern italy) cave: an integrated morphometric and morpho-classificatory approach. quaternary science reviews, 169, 5064. hammer ø., harper d.a.t., ryan p.d. (2001) past: paleontological statistics software package for education and data analysis. palaeontol. electron., 41, 9. mallison h., wings o. (2014) photogrammetry in paleontology a practical guide. journal of paleontological techniques, 12, 1-31. robbins l.m. (1985) footprints. collection, analysis, and interpretation. charles c. thomas publisher, springfield, il. romano m., citton p. (2015) reliability of digit length impression as a character of tetrapod ichnotaxobase: considerations from the carboniferous permian ichnogenus ichniotherium. geol. j., 50, 827 838. romano m., citton p. (2016) crouching theropod at the seaside. matching footprints with metatarsal impressions and theropod autopods: a morphometric approach. geol. mag., 1 17. 42 avanzini m. et al. fig. 3 principal component analysis based on the best-preserved footprints from 'sala dei misteri'. scatter plot of principal components pc1-pc2 and loadings. in the inset the main morphotypes, to which footprints from 'sala dei misteri' have been referred, are show: a child under 5 years of age (morphotype i) and two youth of 6-7 and 11-12 years of age (morphotypes ii and iii respectively). ms. received: may 4, 2018 final text received: may 16, 2018 imp.carveni-benfatto ll’’eerruuzziioonnee eettnneeaa ddeell 11886655 ((mmoonnttii ssaarrttoorriiuuss)):: aassppeettttii ggeeoommoorrffoollooggiiccii ee iinnqquuaaddrraammeennttoo nneellll’’eevvoolluuzziioonnee ddeell vvuullccaannoo ppiieettrroo ccaarrvveennii11 && ss.. bbeennffaattttoo22 1dipartimento di scienze geologiche dell’università di catania, sezione geologia e geofisica, corso italia 55, 95129 catania, italia. 2geologo, libero professionista, via san marco 91, 95047 paternò, (ct), italia. riassunto: carveni p. & benfatto s., l’eruzione etnea del 1865 (monti sartorius): aspetti geomorfologici e inquadramento nell’evoluzione del vulcano. (it issn 0394 – 3356, 2004). sulla base di una rilettura critica delle relazioni di autori testimoni dell'evento, dell’analisi di aerofotografie e di rilievi geomorfologici di dettaglio, viene ricostruita l’eruzione laterale etnea del 1865, durante la quale si sono formati i monti sartorius. nella zona del vulcano interessata dall’eruzione sono presenti edifici piroclastici preistorici, geneticamente collegati a fratture eruttive con direzione enewsw, con progressiva migrazione verso se delle fratture eruttive. l’eruzione in studio è stata alimentata attraverso due distinte serie di fratture eruttive, una con direzione ene-wsw, concordante con quella delle strutture distensive riconosciute nel settore d’interesse, l’altra con direzioni comprese tra n 10° ÷ 25° w, e coincidenti con quelle delle faglie normali che formano la scarpata ibleo-maltese. la ricaduta balistica dei materiali piroclastici, condizionata dalle condizioni atmosferiche, ha dato luogo ad edifici asimmetrici. l’analisi morfologica mette in evidenza la ripresa dell’attività in corrispondenza di precedenti apparati e una ripresa recente dell’attività da una delle bocche eruttive. abstract: carveni p. & benfatto s., 1865 monti sartorius eruption: morphologic aspects in the frame of mt. etna evolution. (it issn 0394 – 3356, 2004). the eruptive phenomenology and the morphological aspects of 1865, january 28th – june 15th mount etna lateral eruption are described in this paper. mount etna is the largest european active volcano; it is formed by the volcanic products of many eruptive centres. mount etna is located on the margin of the two main structural domains of eastern sicily: the iblean foreland and the apenninesmaghrebian chain; the first belongs to the northern part of the african plate and consists of a mainly carbonate succession of triassic to pleistocene age, with several intercalations of mafic volcanic rocks; the apennines-maghrebian chain consists of several thrust sheets, made up of structural units derived from different palaeogeografic regions. many studies about structural patterns of mount etna identified four tectonic trends: n-s, ene-wsw, ne-sw and nw-se. this eruption occurred along the ne flank of the volcanic edifice; some prehistorical vents were active in this zone: the position and chronology of these cones demonstrate a progressive displacement of eruptive fissures toward se. a trustworthy reconstruction of this etna eruption is based on papers of witnesses, on aerial photo analysis and on geological and geomorphologic surveys. the feeder system of the eruption was characterized by two eruptive fracture systems: the main system, ene-wsw oriented; a cluster of fractures ranging n-s to nnw-sse forms the latter. morphological analysis suggests several volcanic activities at different times; the last is witnessed by undated new vent. parole chiave: etna, eruzione laterale del 1865, morfologia. keywords: 1865 lateral eruption on mount etna volcano (sicily), geomorphology. il quaternario italian journal of quaternary sciences 1177(1), 2004, 41-54 11.. iinnttrroodduuzziioonnee il 29 gennaio 1865 iniziò sull’etna un’eruzione laterale le cui fasi sono state descritte, con diverse lacune temporali causate dalle condizioni atmosferiche, da grassi (1865) e silvestri (1867). la rilettura critica dei documenti bibliografici è stata seguita da un’analisi di fotografie aeree e da un rilievo geologico-geomorfologico di dettaglio, al fine di analizzare la distribuzione delle fratture e delle bocche eruttive, le forme di accumulo dei depositi piroclastici e l’azione morfologica dell’erosione. questa eruzione è già stata oggetto di studio (carveni et al., 1998; 2000): nel presente articolo verranno puntualizzati alcuni aspetti che, per motivi di spazio, non hanno trovato il giusto rilievo nei precedenti. nei primi due articoli sono state distinte tre fasi dell’eruzione, collegate alla fluttuazione del tasso di emissione istantaneo, sono state studiate le morfologie di flusso delle colate, ed è stata riconosciuta l’esistenza di due distinti allineamenti di fratture eruttive. 22.. qquuaaddrroo ggeeoollooggiiccoo--ssttrruuttttuurraallee ddeell-ll’’aarreeaa eettnneeaa l’etna, il vulcano attivo più grande d'europa, è uno stratovulcano risultante dalla sovrapposizione dei prodotti emessi durante gli ultimi 700.000 anni da numerosi apparati eruttivi, poggianti su un substrato in parte alloctono, in parte formato da depositi miocenico-quaternari (romano et al., 1979). l’etna sorge su un’area di debolezza tettonica ubicata all’intersezione di allineamenti tettonici regionali (ogniben et al., 1975), lungo la sutura tra la placca africana e la placca europea, dove la crosta oceanica ionica e la crosta continentale dell’avampaese ibleo si immergono sotto il fronte dell’orogene appenninicomaghrebide (finetti et al., 1996) (fig. 1). l’avampaese ibleo, rappresentante in sicilia orientale il margine della placca africana (burollet et al., 1978), zona considerata stabile verso cui convergono le falde neogeniche dell ’orogene appenninicomaghrebide, confina ad oriente con la crosta oceanica 42 p. carveni & s. benfatto del bacino ionico (finetti, 1982) tramite la scarpata ibleo-maltese, la cui origine tettonica è stata riconosciuta, tramite profili sismici, da finetti & morelli (1972); essa è stata originata da un sistema di faglie normali a gradinata, il cui prolungamento verso settentrione interseca il fianco orientale dell’edificio etneo (lo giudice et al., 1982; carbone et al., 1982 a; 1982 b). per casero et al. (1984) essa rappresenta un sistema strutturale distensivo, raccordante il plateau continentale siculomaltese con la piana abissale ionica; la struttura si sarebbe formata in un’unica grande fase tortoniana, con minori riattivazioni posteriormente al deposito degli infrapliocenici trubi; alla scarpata sono connesse a luoghi importanti attività vulcaniche. l’orogene appenninico-maghrebide si è formato in seguito all’accavallamento della catena kabilocalabride sulla catena appenninico-maghrebide (finetti et al., 1996); questa convergenza ha provocato un accorciamento crostale in direzione n-s valutato tra 29 e 33 chilometri (cassinis et al., 1979). recenti fasi tettoniche hanno causato un’elevata distorsione al margine settentrionale della placca africana, a causa della differente velocità con cui avviene la subduzione al di sotto della catena appenninico-maghrebide (van bemmelen, 1969; morelli, 1970; selli & fabbri, 1971; giese & morelli, 1975), e ciò ha determinato uno stiramento crostale che ha dato luogo a fratture con direzione nw-se, ne-sw ed e-w (ghisetti & vezzani, 1982; scandone, 1982); all’intersezione di tali strutture si è formata una zona di debolezza attraverso la quale avviene la risalita di magmi subcrustali (frazzetta & villari, 1981). l’attività eruttiva, inizialmente sottomarina e fissurale, è diventata in seguito subaerea ed a carattere centrale, a causa di un sollevamento regionale, tutt’ora in atto, che ha determinato una variazione nel meccanismo di risalita dei magmi, con conseguente cambiamento del chimismo: si passa infatti da prodotti subalcalini a prodotti più o meno differenziati della serie alcalinosodica emessi da numerosi centri eruttivi e raggruppati in quattro unità vulcano-stratigrafiche: centri alcalini antichi, trifoglietto s.l., mongibello antico e mongibello recente (romano, 1982). sulla base di datazioni radiometriche del rapporto k/ar, gillot et al. (1994) hanno distinto quattro periodi di attività dell’etna: il primo periodo (da 520.0000 ± 40.000 a 270.000 anni fa) è caratterizzato da vulcanismo tholeiitico, con fasi eruttive separate da lunghi periodi di quiescenza; il secondo periodo (da 168.000 ± 8.000 a 100.000 anni fa) è evidenziato da un radicale cambiamento del tipo di attività (strato-vulcani al posto di fessure eruttive) e del chimismo dei prodotti (da sub-alcalini ad alcalini); durante il terzo periodo (tra 80.000 e 60.000 anni fa) si formò un grande complesso vulcanico poligenico (unità del trifoglietto); il quarto periodo (da 35.000 anni fa ad oggi) corrisponde allo sviluppo di un grande strato-vulcano, il mongibello; un’importante fase esplosiva, caratterizzata da eruzioni pliniane e idromagmatiche, permette di suddividere questo periodo in due parti: mongibello antico e mongibello recente. carapezza (1962) per primo cerca di determinare una relazione tra la tettonica regionale e le zone di minore resistenza del vulcano, dalle quali hanno origine le eruzioni; egli riconosce una zona di rift, che attraversa il fianco orientale dell’edificio vulcanico, e lungo la quale si concentra l’attività vulcanica recente. nel primo studio analitico sulle faglie dell’etna (marchesini et al., 1964) sono stati riconosciuti quattro gruppi principali di allineamenti tettonici, con direzioni ns, ene-wsw, ne-sw e nw-se. romano (1970) e rittmann et al. (1973) confermano l’importanza dei trend n-s e ene-wsw. kieffer (1975) riconosce una zona di rift che attraversa la zona sommitale del vulcano da nord a sud, lungo cui si concentrano le eruzioni recenti. frazzetta & romano (1978) identificano due allineamenti come alimentatori preferenziali per le aree con alta probabilità di nuove eruzioni: la principale è compresa tra ne-sw e ene-wsw, la seconda ha direzione nnw-sse. sulla base delle ipotesi di nakamura (1977) e di nakamura et al., (1977), frazzetta & villari (1981) utilizzano gli allineamenti di fratture e coni piroclastici per determinare i campi di stress dell’etna e riconoscono una zona e-w con trascorrenza sinistra e con σ1 ene e σ3 nnw. per lo giudice et al. (1982), invece σ1 ha orientazione nne e σ3 wnw; essi riconoscono nell'area etnea e nelle zone circostanti varie direttrici di faglie: le più importanti hanno direzione n 60° e, n 30° e, n 15° w e n 60° w. kieffer (1983 a; 1983 b) definisce, in base alle numerose fratture collegate alle eruzioni, un “rift di ne”, un rift meridionale e una serie di assi nw-se e ne-sw; le faglie delle due zone di rift e le faglie della zona delle timpe farebbero parte di una serie di faglie normali che interessano la parte orientale del vulcano e del suo substrato; l’intrusione ripetuta di magma provocherebbe uno scivolamento gravitativo della parte orientale del vulcano. l’ipotesi di uno scivolamento gravitativo di una porzione dell’edificio etneo viene ripresa e sviluppata da azzaro et al. (1989 a) e da neri et al. (1991); questi ultimi distinguono sul versante orientale dell’etna un settore settentrionale, caratterizzato da meccanismi di dislocazione distensiva con componenti orizzontali sinistre, ed uno meridionale, distensivo con componenti orizzonfig. 1 ubicazione dell'area studiata. cckkcc) catena kabilocalabride; ccaamm) catena appenninico-maghrebide; ccss) catena sicana; aaii) avampaese ibleo; ee) edificio vulcanico etneo (da finetti et al., 1996); il quadrato grigio indica la zona dell’eruzione del 1865. localization of studied area. cckkcc) kabilo-calabrian chain; ccaamm)) apenninian-maghrebian chain; ccss) sicanian chain; aaii) iblean foreland; ee) mt etna volcano (after finetti et al., 1996); grey square points out the 1865 etna eruption area. tali destre; tali condizioni di instabilità influenzano la risalita dei magmi in questo settore del vulcano, specialmente lungo il trend nnw-sse (ferrucci et al., 1993). borgia et al. (1992), basandosi sui risultati delle analisi di ferrari et al. (1991) sui dicchi affioranti nella valle del bove, teorizzano uno spreading radiale del 43l’eruzione etnea del 1865 ... sub-strato dell'etna verso se. secondo lo giudice & rasà (1992) si tratta invece di movimenti puramente gravitativi, che provocano uno scivolamento verso sse del settore del versante orientale dell’etna delimitato dalla faglia della pernicana, dal “rift di ne” e dalle faglie di mascalucia-trecastagni (fig. 2). fig. 2 ubicazione dell'area interessata dall'eruzione, in rapporto alle più importanti strutture vulcano-tettoniche del versante nordorientale dell'etna: cccc) cratere centrale; ffmmaa) faglia di mascalucia; ffmmoo) faglia di moscarello; ffmmss) faglia macchia – stazzo; ffpp) faglia della pernicana; ffppvvcc) faglia praiola – villa calanna; ffssll) faglia di san leonardello; fftt) faglia di trecastagni; rrnn) faglia della ripa della naca; rrnnee) rift di ne; rrpp) faglia della ripa di piscio. centri abitati e contrade: aarr) acireale; g) giarre; mm) mascalucia; mmaa) monti arsi; ssaa) sant'alfio; ssgg) san giovanni; tt) trecastagni. i cerchi piccoli indicano l'ubicazione di coni avventizi, le aree contrassegnate dai numeri 11886655, 11992288 e 11997711 indicano le zone coperte dalla lava durante le relative eruzioni. location of area interested by 1865 etna eruption in the frame of the main volcanic-tectonic structures of north-eastern flank of mt. etna volcano: cccc) central crater; ffmmaa) mascalucia fault; ffmmoo)) moscarello fault; ffmmss) macchia – stazzo fault; ffpp)) pernicana fault; ffppvvcc) praiola – villa calanna fault; ffssll) san leonardello fault; fftt)) trecastagni fault; rrnn) ripa della naca fault; rrnnee)) ne rift; rrpp) ripa di piscio fault. towns and districts: aarr) acireale; g) giarre; mm) mascalucia; mmaa) monti arsi; ssaa) sant'alfio; ssgg) san giovanni; t) trecastagni. little circles correspond to cinder cones; the areas marked by the numbers 11886655,, 11992288 and 11997711 correspond to zones covered by lava flows during these eruptions. 44 in una serie di articoli viene analizzata la documentazione storica relativa ai terremoti avvenuti sul basso versante orientale etneo negli ultimi due secoli e le conseguenze dei movimenti tettonici sulla morfologia (adorni & carveni, 1993 a; 1993 b; carveni & bella, 1994; bella et al., 1996; carveni et al., 1996; gresta et al., 1997); sulla base dei dati geoelettrici forniti da cassinis et al. (1970), confrontati con le profondità ipocentrali calcolate per alcuni sismi (postpischl, 1985; azzaro et al., 1989 a; 1989 b; bottari et al., 1989), carveni et al. (1997) ipotizzano che gli ipocentri di alcuni terremoti siano localizzati in corrispondenza del passaggio dalle argille azzurre pleistoceniche ai soprastanti prodotti vulcanici. dall’analisi dei differenti sistemi di faglia che nel corso del pleistocene sono stati attivi in calabria meridionale e nella sicilia orientale, e sulla base di informazioni geologico-strutturali e morfologiche di campagna e dell’analisi di sezioni sismiche a mare, monaco & tortorici (1995) e monaco et al. (1995; 1997) distinguono un “sistema acireale – s. alfio” (formato da faglie normali con componente trascorrente destra nnw-sse) e un “sistema di piedimonte” (faglie normali e fratture d’estensione nne-ssw); entrambi i sistemi, che sono associati ad un’estensione wnw-ese, formano scarpate di età suprapleistocenico-olocenica, le quali esercitano un controllo sulla topografia e sul reticolo idrografico. l’edificio vulcanico etneo è caratterizzato da numerosi apparati eruttivi effimeri, molti dei quali sono concentrati lungo tre trend vulcano-tettonici convergenti verso la sommità del vulcano; il primo (“rift di ne”, kieffer, 1983 a; 1983 b) va dai crateri sommitali verso ne (fig. 2: rrnnee), ed è interessato da fessurazioni estensionali con rare faglie normali (borgia et al., 1992); il secondo, ubicato sul fianco meridionale (kieffer, 1983 a; 1983 b) è formato da faglie transdistensive con abbassamento del blocco orientale (borgia et al., 1992; mc guire et al., 1996); il terzo, sul versante occidentale, è caratterizzato da faglie con strike-slip in direzione ne (ferrucci & patanè, 1993). 33.. tteeaattrroo ddeellll’’eerruuzziioonnee l’eruzione in studio è avvenuta in un’area compresa tra importanti elementi morfostrutturali: la scarpata della faglia della pernicana a settentrione, il “rift di ne” a nw, l’orlo settentrionale della valle del bove a meridione e le scarpate delle faglie della ripa della naca e della ripa di piscio a oriente (fig. 3). questo settore dell’edificio vulcanico presenta caratteri tettonici omogenei, rappresentati da stress di fig. 3 a) ubicazione dell’area studiata. b) schema del teatro dell’eruzione: a) faglie; b) fratture eruttive; c) coni piroclastici: 11) monte corvo; 22) monte baracca; 33 e 44) i due monti; 55) monte zappinazzo e monti conconi; 66) monte frumento delle concazze; 77) edificio anonimo a sud-ovest di monte frumento delle concazze; 88) monti sartorius; 99) bocche del 1928; d) orlo della valle del bove; e) alti morfologici: 1100) monte crìsimo; 1111) monte ragamo; 1122) monte chiovazzi; α) colata principale; β) colata di monte crìsimo; γ) colata di monte ragamo; δ) colata di monte chiovazzi. a) location of the studied area. b) scheme of the eruption zone: a) faults; b) eruptive fractures; c) cinder cones: 11) monte corvo; 22) monte baracca; 33 and 44) i due monti; 55) monte zappinazzo and monti conconi; 66) monte frumento delle concazze; 77) no name cinder cone sw from monte frumento delle concazze; 88) monti sartorius; 99) 1928 eruption’s vents; d) valle del bove rim; e) peaks: 1100) monte crìsimo; 1111) monte ragamo; 1122) monte chiovazzi; α) main lava flow; β) monte crìsimo lava flow; γ) monte ragamo lava flow; δ) monte chiovazzi lava flow. p. carveni & s. benfatto 45 tipo transtensivo a componente orizzontale sinistra (neri et al., 1991); l’area è stata interessata in precedenza da eruzioni laterali che evidenziano un progressivo spostamento verso se delle fratture eruttive; dall’analisi della carta geologica del monte etna (romano et al., 1979) risulta che in epoca preistorica si sono formati, progressivamente, monte corvo (fig. 3: 11), monte baracca (fig. 3: 22), i due monti (fig. 3: 33 e 44), monte zappinazzo e i monti conconi (fig. 3: 55), monte frumento delle concazze (fig. 3: 66) e un edificio anonimo a sw di questo (fig. 3: 77). dall’orientamento delle basi ellittiche degli edifici e dalla forma degli orli craterici si desume che tutti questi edifici sono stati alimentati da fratture con direzioni comprese tra ne-sw e ene-wsw. monte corvo (fig. 3: 11), che poggia su lave dei centri eruttivi del leone, si è formato nel periodo di transizione tra l’attività del mongibello antico e del mongibello recente (romano et al., 1979); non gli sono state attribuite colate laviche. monte baracca (fig. 3: 22), la cui attività risale allo stesso periodo, ha emesso una colata lavica attribuita ai centri del mongibello antico e classificata come “difficilmente delimitabile a morfologia superficiale degradata” (romano et al., 1979). la colata di monte baracca è in parte ricoperta dall’edificio meridionale dei due monti (fig. 3: 33), i quali a loro volta hanno emesso lave classificate come “delimitabili a morfologia superficiale ben conservata” (romano et al., 1979). il gruppo dei monti zappinazzo – monti conconi (fig. 3: 55), che poggiano chiaramente sui prodotti vulcanici già descritti, sono classificati come “colate laviche e piroclastiti recenti, prevalentemente non datate” (romano et al., 1979). infine, monte frumento delle concazze (fig. 3: 66), alla cui attività sono attribuibili delle “colate laviche e piroclastiti recenti, prevalentemente non datate” (romano et al., 1979), sulle quali si sono riversate le lave dell’eruzione in oggetto, e che affiorano in alcune zone come dagale, ricopre parzialmente il fianco meridionale di monte zappinazzo. nel 1928 e nel 1971 sono avvenute altre eruzioni che hanno coinvolto lo stesso settore dell’edificio vulcanico, sempre con una progressiva migrazione verso se delle fratture eruttive (fig. 3); nel 1979 si è avuta una nuova emissione dalla frattura eruttiva del 1928. l’eruzione etnea del 1865, quindi, segna la ripresa dell’attività vulcanica in un settore dell’etna già interessato da eruzioni laterali, con progressiva migrazione dell’asse eruttivo verso se, e, come si vedrà in seguito, geneticamente collegate sia a fratture eruttive con direzioni comprese tra ne-sw e ene-wsw, sia a fratture comprese tra nnw-sse e n-s, direzioni già riconosciute come quelle con maggiore probabilità di riattivazione per questo settore del vulcano (romano, 1970; rittmann et al., 1973; frazzetta & romano, 1978). 44.. ccrroonnaaccaa ddeellll’’eerruuzziioonnee i primi sintomi di un incipiente eruzione laterale si manifestarono alle 14,30 del 28 gennaio 1865: furono osservate nuvole di fumo (emissioni di cenere, secondo romano & sturiale, 1982) sollevarsi da monte frumento delle concazze; durante la notte successiva numerose scosse sismiche allarmarono gli abitanti di san giovanni e sant’alfio e della contrada monti arsi, località ubicate lungo il prolungamento settentrionale delle faglie di moscarello, san leonardello e macchia-stazzo (fig. 2), riconosciute come le più attive tra quelle che interessano il versante orientale dell’etna (carveni & bella, 1994). il giorno dopo le scosse aumentarono in frequenza ed intensità, e la più forte, avvenuta intorno alle 23, fu del v grado della scala mercalli nelle già citate località, e si propagò fino ad acireale, distante circa 16 chilometri dal presunto epicentro, ma non fu avvertita a giarre, che ne dista solo sei; dalla direzione di massima propagazione delle onde sismiche, riteniamo che questi terremoti siano da attribuire a faglie con direzione nnwsse, collegabili ad una o più delle faglie nominate. in coincidenza con quest’ultima scossa iniziò l’emissione di lava dal basso fianco nord-orientale di monte frumento delle concazze, mentre l’attività sismica continuò per alcune ore, con intensità decrescente; nel frattempo il cratere centrale non dava luogo ad alcuna attività. nella fase iniziale dell’eruzione si formarono tre fontane di lava lungo una frattura eruttiva, tra le quote 1800 e 1725 (figg. 4 e 5: iiii); porzioni della relativa colata lavica, che raggiunse 2,6 metri di altezza, come è dimostrato dai tronchi carbonizzati lungo il suo percorso (silvestri, 1867), affiorano al di sotto delle coperture piroclastiche dell’edificio aa (figg. 4 e 5: α); questa prima fase si esaurì in poche ore, e le fontane di lava vennero sostituite da tre bocche esplosive (figg. 4 e 5: 11, 22 e 33; fig. 6). il 30 gennaio, mentre le bocche 11, 22 e 33 erano in piena attività stromboliana, a oriente di monte frumento delle concazze si aprì una fenditura di 400 metri di lunghezza con direzione n 20° w (figg. 4 e 5: iiiiii), lungo la quale si attivarono otto fontane di lava (grassi, 1865), le cui piroclastiti hanno formato altrettanti coni di scorie (fig. 5: 44 ÷ 1111). col procedere dell'eruzione le fratture eruttive continuarono a propagarsi verso oriente, provocando la progressiva migrazione sia dei punti di emissione delle colate, sia delle bocche esplosive che man mano li rimpiazzavano: si formarono così di seguito gli edifici piroclastici aa, bb, cc, dd ed ee (figg. 4 e 5) le cui bocche furono quasi tutte attive contemporaneamente tra il 4 e il 5 febbraio. nella tabella 1 è sinteticamente riportata l'attività relativa alle bocche di ciascun edificio, così come si ricava dalle relazioni di grassi (1865) e silvestri (1867): all’iniziale fase parossistica, caratterizzata dall’attività contemporanea di quasi tutti gli apparati eruttivi, seguì una progressiva diminuzione dell’intensità dei fenomeni, con sporadici rinvigorimenti da parte di uno o più apparati. silvestri (1867) distinse già dai primi giorni di febbraio una colata principale (fig. 3: α) e una colata di monte crìsimo (fig. 3: β); la prima raggiunse il punto più basso della sua corsa il 9 febbraio; da questa data fino ai primi di marzo si assistette ad un arretramento del fronte attivo ed un allargamento del settore mediano del campo lavico; nel frattempo venne emessa una terza colata (colata di monte ragamo, fig. 3: γ), che si fermò il 12 febbraio. infine la colata di monte chiovazzi (fig. 3: δ) venne emessa da tre fratture, ubicate rispettival’eruzione etnea del 1865 ... 46 mente alla base settentrionale del cono bb, tra gli edifici dd ed e, alla base nord-orientale dell’edificio ee (fig. 5); essa raggiunse il suo punto più basso il 4 aprile. l’attività eruttiva si estinse del tutto alla metà di giugno. 55.. aassppeettttii mmoorrffoollooggiiccii 55..11.. ii ssiisstteemmii ddii ffrraattttuurree eerruuttttiivvee dalla rilettura critica delle relazioni dei precedenti autori (grassi, 1865; silvestri, 1867), dalla distribuzione fig. 4 e fig. 5 schema della zona dei monti sartorius: le lettere dell'alfabeto latino indicano gli edifici piroclastici formatisi durante l'eruzione in studio (aa ÷ ee) e quelli preesistenti (ss ÷ zz), le lettere dell’alfabeto greco le colate laviche, le cifre romane i tratti delle fratture eruttive descritti nel testo, le cifre arabe le bocche esplosive (cerchio pieno per quelle certe, cerchio vuoto per quelle presunte). monti sartorius zone scheme: latin alphabet letters designate cinder cones formed during 1865 etna eruption (aa ÷ ee) and prehesistent ones (ss ÷ zz); greek alphabet letters designate lava flows; roman numerals designate segments of eruptives fractures; arab numerals indicate explosive vents (full circles correspond to sure ones, empty circles to probable vents). p. carveni & s. benfatto spaziale di fratture, bocche eruttive e accumuli piroclastici, si ricava che l’eruzione in studio è stata alimentata da due distinti sistemi di fratture: il primo (sistema principale di fratture eruttive) è radiale rispetto al condotto centrale dell’etna e ha direzione ene-wsw; il secondo (sistema secondario di fratture eruttive) è formato da fratture con direzioni comprese tra nnw-sse e n-s (carveni et al., 1998; 2000). parte del primo tratto del sistema principale di fratture eruttive (fig. 4: i) è riconoscibile su una fotografia pubblicata da silvestri (1867): sul fianco nord-orientale di monte frumento delle concazze, a partire dalla profonda svasatura dell’orlo craterico, scende una serie di faglie normali con andamento ad “s”; il graben cui danno luogo ha un’ampiezza massima, in corrispondenza dell’orlo craterico, di 50 metri, mentre verso il basso l’ampiezza diminuisce fino a 2 metri in corrispondenza del punto d’inizio dell’emissione; tracce di questo graben sono tuttora riconoscibili sul terreno, malgrado esso sia impostato su piroclastiti: in occasione di forti precipitazioni atmosferiche, infatti, le acque di ruscellamento si incanalano lungo le linee di faglia. secondo quanto riferito da silvestri (1867), la frattura poteva essere seguita dal crinale della valle del bove fino al cratere di monte frumento delle concazze, per una lunghezza complessiva di circa due chilometri e mezzo. il secondo tratto (fig. 4 e 5: iiii), corrispondente al segmento della frattura eruttiva lungo cui si attivarono le prime tre fontane di lava, è compreso tra 1800 e 1725 metri di quota; la frattura è beante ed ispezionabile per un tratto di circa 350 metri e fino ad una profondità massima di 8 metri circa. un’altra frattura dello stesso sistema è evidenziata dall’allineamento delle bocche eruttive nei crateri degli edifici bb, cc e dd (figg. 4 e 5: iivv). ulteriori allineamenti di bocche eruttive e di depositi piroclastici consentono di riconoscere il sistema secondario di fratture eruttive; alcuni suoi elementi, inoltre, sono stati descritti da grassi (1865) e da silvestri (1867). il primo segmento di questo sistema è quello che disloca il tratto i del sistema principale di fratture eruttive, e corrisponde alla prosecuzione verso meridione della frattura eruttiva dei crateri di monte zappinazzo (fig. 4: vv). il secondo corrisponde alla frattura eruttiva che ha alimentato le 8 fontane di lava descritte da grassi (1865) (figg. 4 e 5: iiiiii). il terzo ha alimentato le bocche dei crateri aa11, aa22 e aa33 (figg. 4 e 5: vvii). silvestri (1867) ha descritto due fessure rettilinee, tangenti all’orlo occidentale del cratere dell’edificio bb, le quali emettevano unicamente vapori (figg. 4 e 5: vviiii). infine, alcune morfosculture parallele alle fratture del sistema secondario sono state individuate tramite l’analisi di fotografie aeree: tre di esse sono piccole scarpate rettilinee assimilabili a faglie con blocco orientale ribassato (figg. 4 e 5: vviiiiii, iixx e xx). 55..22.. ggllii eeddiiffiiccii ppiirrooccllaassttiiccii gli accumuli delle piroclastiti emesse nel corso dell’eruzione in esame formano una serie di coni di scorie a forma di scudo, di spatter cones e di edifici troncoconici con crateri sommitali; forme e dimensioni sono state determinate tramite carte topografiche in scala 1:10.000 e l’analisi di aerofotografie; per alcune morfologie non rappresentate cartograficamente a causa delle ridotte dimensioni sono state effettuate misure speditive in campagna. i coni a scudo 11, 22 e 33 sono tre edifici tra loro coalescenti, ubicati sul basso versante nord-orientale di monte frumento delle concazze (fig. 6); nella già citata fotografia (silvestri, 1867) si vede che questi tre edifici preesistevano all’eruzione in studio: si tratta quindi di edifici poligenici, già collegati ad un’attività preistorica dell’edificio suddetto, e riattivatosi nel corso dell’eruzione del 1865. essi hanno forma a scudo con contorno ellittico, 47l’eruzione etnea del 1865 ... tab. 1 sequenza temporale dell’attività delle bocche eruttive. vents activity sequences. ddaattee ddeellllee oosssseerrvvaazziioonnii 28.1 29.1 30.1 31.1 3.2 4.2 5.2 6.2 20.2 26.2 5.3 19.3 25.3 15.4 28.4 6.5 15.5 1 f l e c i 2 f l e e e e 3 f l e e e e 4-11 f l a 1 e e i o a 2 e e e e e ? c c e i o a 3 e e e e e ? c c e i o b e e e c e c v e e e e c e e e c e o d e e e c d d d o i e e e e e v a v a e e v s s legenda: s) scosse sismiche; f l) fontane di lava; e) esplosioni con lancio di scorie e bombe; c) emissione di ceneri; v a) emissione di vapori ad alta pressione; v) emissione tranquilla di vapore; d) detonazioni; i) bocche inattive; o) condotto ostruito. explanation notes: s) earthquakes; f l) lava fountains; e) explosions with cinder and bombs throwing; c) ash emission; v a) high pressure steam issue; v) calm steam issue; d) detonations; i) inactive vent; o) obstructed duct con l’asse maggiore lungo la frattura eruttiva, la quale permette un’analisi della struttura interna degli edifici; dal basso affiora la seguente successione: scorie e lapilli saldati, di colore rossastro; dalla giacitura si evince che provenivano da diversi punti di emissione; lo spessore in affioramento raggiunge i 3 metri; basalto a fessurazione colonnare, con spessore massimo in affioramento di 2 metri; sulle pareti si trovano scorie saldate, presumibilmente relative all’evento eruttivo in studio; scorie e bombe saldate, di colore grigio, con spessore massimo di 4 metri; scorie e bombe saldate, con spessore massimo di 3 metri, relative all’eruzione in oggetto; uno strato discontinuo di cineriti alterate permette di distinguere questo banco dal precedente. in corrispondenza delle bocche eruttive queste ultime piroclastiti raggiungono il massimo spessore. la presenza, al di sotto delle piroclastiti attribuite all’eruzione in studio di altri due livelli di scorie e bombe saldate, cui si intercala una colata basaltica, conferma l’ipotesi di riattivazione della frattura in oggetto. l’esame delle fotografie aeree evidenzia che gli edifici sono ubicati in una depressione di forma trapezoidale, delimitata da scarpate rettilinee, presumibilmente corrispondenti a piani di faglie dirette (figg. 4 e 5: xxii, xxiiii e xxiiiiii), il cui riscontro sul terreno è problematico, a causa delle coperture piroclastiche ed epiclastiche. le dimensioni dei tre edifici sono riportate nella tab. 2; un calcolo approssimativo del volume del materiale eruttato dalle relative bocche durante la fase iniziale dell’eruzione risulterebbe in difetto, in quanto la parte maggiore dei materiali emessi dalle fontane di lava attive il 29 gennaio alimentò la prima colata lavica, e le scorie e bombe relative all’attività esplosiva protrattasi dal 30 gennaio al 4 febbraio ebbero un’ampia zona di dispersione: secondo silvestri (1867) bombe fino a un metro di diametro vennero scagliate a più di 500 metri di distanza, e le pendici del monte frumento delle concazze furono ricoperte da uno strato di scorie e lapilli spesso fino a 15 centimetri. gli spatter cones 44 ÷ 1111 sono 8 collinette dalla cima tondeggiante (fig. 5: 44 ÷ 1111), formatesi il 30 gennaio 1865 (grassi, 1865) per l’accumulo dei materiali emessi da 8 fontane di lava ubicate lungo una frattura eruttiva con direzione n 20° w (figg. 4 e 5: iiiiii); esse in seguito sono state parzialmente ricoperte da piroclastiti emesse dalle bocche dell’edificio aa (fig. 7). nella tabella 2 sono riportati i loro parametri; l’andamento circolare delle loro basi è da attribuire ad una distribuzione delle piroclastiti poco o per nulla condizionata dagli agenti atmosferici, su una superficie quasi orizzontale; anche qui il calcolo del volume emesso risulta in difetto, considerando che parte del materiale diede luogo ad una colata lavica, attualmente sepolta dall’edificio a. 48 fig. 7 il cono di scorie 1100, parzialmente ricoperto (a destra) dalle piroclastiti dell’edificio aa, visto da meridione. spatter cone 1100 from south. its right flank is covered by cinder cone aa pyroclastics. fig. 6 panoramica sui coni di scorie 11, 22 e 33, visti da oriente, dall’orlo occidentale del cratere aa22. panoramic view on 11, 22 and 33 scoria cones, from western rim of aa22 crater. p. carveni & s. benfatto i coni di scorie aa ÷ ee sono edifici troncoconici con crateri sommitali; i loro crateri, esauritasi l’attività vulcanica, hanno subito, a causa degli agenti atmosferici, l’erosione degli orli con accumulo dei materiali all’interno, e conseguente trasformazione da crateri a imbuto con condotto aperto in cavità a forma di conca, in alcuni casi a fondo piatto: dall’iniziale superficie di accumulo delle piroclastiti, sviluppatasi in funzione dell’attività vulcanica e degli agenti meteorologici (che ne condizionavano la traiettoria balistica e la distribuzione), si è passato ad una superficie di erosione a monte – accumulo a valle, funzione degli agenti esogeni; fa eccezione il cratere bb, come verrà descritto più avanti. l'edificio aa (figg. 4 e 5) è un edificio composito, formato da due tronchi di cono coalescenti (fig. 8), allineati in direzione n 10° w, con 2 crateri maggiori ellittici (fig. 5: aa22 e aa33) con asse maggiore orientato nnwsse; sul versante nw del cono settentrionale si apre un cratere (fig. 9) di minori dimensioni (fig. 5: aa11), il cui edificio è stato quasi del tutto sepolto dalle piroclastiti emesse dalle bocche del cratere aa22. le tre cavità crateriche hanno forma di semisfera e sono interessate da fenomeni erosivi, con conseguente arretramento dell'orlo craterico; sul fondo non c'è traccia delle bocche eruttive che, secondo silvestri (1867), erano una nel cratere aa11, tre disposte in direzione nnw-sse nel cratere aa22, e tre, ai vertici di un triangolo equilatero, nel cratere aa33; il fondo dei crateri aa22 e aa33 è allungato in senso nnw-sse, parallelamente alla frattura eruttiva vvii (figg. 4 e 5; tab. 3). la forma ellittica presentata dalla base dal cono aa22 (tab. 3) è da attribuire all’allineamento delle sue tre bocche eruttive lungo la frattura vvii (fig. 5); la non concordanza con la forma dell’orlo craterico può derivare da fenomeni erosivi che hanno aggredito con maggiore vigore la parte più alta dell’edificio conico, provocando un veloce arretramento dell’orlo craterico. l’asse maggiore della base dell’edificio aa33 ha azimut n 82°, il minore n 172°: ciò può essere spiegato con la distribuzione spaziale delle tre bocche eruttive, ai vertici di un triangolo, che danno luogo a due allineamenti: la frattura iivv e la frattura vvii (fig. 5); la forma ellittica dell’orlo craterico è coerente con quella della base dell’edificio. l'edificio bb presenta ben esposti il versante settentrionale (60 metri di dislivello massimo tra l'orlo del cratere e la base dell'edificio) e quello meridionale (55 metri), mentre quello occidentale è coalescente con l'edificio aa e quello orientale con l'edificio cc. l’orlo craterico ha forma ellittica, diametro massimo di 120 metri in direzione n 60° e; l’andamento altimetrico è caratterizzato da un massimo assoluto ad occidente e un massimo relativo a meridione; il punto più basso è a ene, dove il cratere si apre verso l’edificio c. i parametri relativi alla base dell’edificio non sono indicativi (tabella 3), perché condizionati dagli altri edifici coalescenti; gli assi dell’ellisse dell’orlo craterico sono coerenti con la direzione della frattura eruttiva iv (fig. 5). l’erosione della cavità craterica ha messo in evidenza la struttura interna dell’edificio: lungo alcuni tratti delle pareti quasi verticali affiorano bombe e scorie saldate (fig. 10). i materiali erosi dalle pareti e accumulatisi sul fondo del cratere hanno fatto assumere a questo una forma a semisfera; tre deboli depressioni circolari, corrispondenti ad altrettante bocche eruttive, si trovano sul fondo del cratere; una quarta bocca, situata quasi al centro della cavità craterica, con 8 metri di diametro e 3 di profondità, circondata da un anello di scorie e bombe saldate alto tra 50 e 80 centimetri (fig. 11), in contrasto con tutte le altre bocche dei monti sartorius presenta 49 fig. 8 l’edificio aa con i crateri aa22 e aa33, visto da sw (foto di s. surrentino). aa volcanic building, with aa22 and aa33 craters from sw. l’eruzione etnea del 1865 ... tab. 2 principali parametri degli edifici piroclastici minori. main parameter of little pyroclastic buildings aa bb cc 11 85° 125/50 m 3 m 22 65° 110/60 m 4,5 m 33 65° 170/110 m 6 m 44 30 m 10 m 55 25 m 8 m 66 25 m 8 m 77 32 m 10 m 88 20 m 6 m 99 30 m 10 m 1100 25 m 7 m 1111 15 m 4 m aa = azimut dell'asse maggiore; bb = diametro massimo/minimo della base dell'edificio; cc = altezza dell'edificio. aa = maximum axis azimuth; bb = length of base maximum/minimum axis; cc = building height. un aspetto molto più “giovane”, e testimonia, a nostro avviso, una ripresa dell’attività eruttiva sfuggita all’osservazione per la sua brevità e/o per il momento in cui è avvenuta; la piccola quantità di materiale emesso (circa 20 metri cubi) suggerisce una singola debole esplosione, avvenuta in un periodo in cui il cratere aveva già raggiunto la fase morfologica a semisfera dal fondo piatto. il fatto che una piccola eruzione dell’etna possa essere passata inosservata in tempi recenti non deve destare alcuna meraviglia: la lontananza dalle zone abitate e soprattutto le condizioni atmosferiche possono aver benissimo impedito l’osservazione di un fenomeno di brevissima durata; d’altro canto l’esplosione verificatasi al cratere sub-terminale di se il 5 gennaio 1990, considerata il maggiore evento esplosivo verificatosi sull’etna nel corso degli ultimi due secoli, a causa delle pessime condizioni meteorologiche non è stata osservata da alcun testimone, e la ricostruzione dell’evento è stata effettuata sulla base della distribuzione delle piroclastiti (carveni et al., 1994). un piccolo affioramento di cineriti saldate, ubicato lungo la parte occidentale dell'orlo craterico, rappresenta i resti dell'originario versante interno, e dà la misura dell'intensità con cui ha agito l'erosione (fig. 12). alla base settentrionale dell'edificio bb si trova uno dei punti di emissione della colata 50 fig. 10 interno del cratere del cono bb visto dal culmine dell’orlo meridionale. panoramic internal view of volcanic building bb crater, from its southern crater rim. fig. 9 il cratere aa11 visto da settentrione, dall’alto dei resti di un preesistente edificio (figg. 4 e 5: s). aa11 crater seen from prehesistent building ss (figg. 4 and 5). p. carveni & s. benfatto tab. 3 principali parametri degli edifici piroclastici maggiori. main parameter of big pyroclastic buildings. 11 22 33 44 55 66 77 88 99 1100 1111 1122 1133 aa11 12 123 10 33 146 292 85 aa22 120 172 110 82 95 82 70 172 65 82 50 262 180 aa33 130 82 100 172 95 80 70 172 60 53 40 154 180 bb 115 242 90 358 120 58 100 148 70 245 45 60 30 cc 35 74 30 164 25 330 20 60 60 dd 125 230 55 50 60 138 55 60 35 156 25 50 90 ee 220 105 75 285 125 25 120 115 60 133 11 = diametro massimo della base dell'edificio, in metri; 22 = azimut del diametro massimo della base dell'edificio; 33 = diametro minimo della base dell'edificio, in metri; 44 = azimut del diametro minimo della base dell'edificio; 55 = diametro massimo dell'orlo del cratere, in metri; 66 = azimut del diametro massimo dell'orlo del cratere; 77 = diametro minimo dell'orlo del cratere, in metri; 88 = azimut del diametro minimo dell'orlo del cratere; 99 = altezza massima dell'orlo del cratere, rispetto al preesistente piano di campagna, in metri; 1100 = azimut del punto di massima altezza dell'orlo del cratere, rispetto al centro del cratere; 1111 = altezza minima dell'orlo del cratere, rispetto al preesistente piano di campagna, in metri; 1122 = azimut del punto di minima altezza dell'orlo del cratere, rispetto al centro del cratere; 1133 = azimut della congiungente due selle lungo gli orli craterici. 11 = length of base maximum axis, m; 22 = azimuth of base maximum axis; 33 = length of base minimum axis, m; 44 = azimuth of base minimum axis; 55 = maximum diameter of the crater edge, m; 66 = azimuth of maximum diameter of the crater edge; 77 = minimum diameter of the crater edge, m; 88 = azimuth of minimum diameter of the crater edge; 99 = maximum height of the crater edge, in comparison to the pre-existing ground level; 1100 = azimuth of the point of the maximum height of the crater edge, in comparison to the centre of the crater; 1111 = minimum height of the crater edge, in comparison to the pre-existing ground level; 1122 = azimuth of the point of the minimum height of the crater edge, in comparison to the centre of the crater; 1133 = azimuth of aligned crater edge depressions. di monte chiovazzi. il cono piroclastico cc (figg. 4 e 5) ha sviluppo massimo di 25 metri di altezza lungo il fianco settentrionale, mentre gli altri versanti sono coalescenti con gli edifici limitrofi; esso presenta tracce di tre piccoli crateri, interessati da fenomeni erosivi. con sviluppo altimetrico massimo di 40 metri e diametro di base di 175, il cono dd ha un cratere del diametro di 50 metri, al cui interno sono state attive quattro bocche eruttive, irregolarmente distribuite (silvestri, 1867). il profilo dell’orlo craterico presenta una forte asimmetria, con due culminazioni, la più alta a sse, l’altra a settentrione; l’irregolarità nella distribuzione delle piroclastiti è stata causata dai forti venti che soffiarono dal quadrante settentrionale nella fase iniziale dell’eruzione, e dal quadrante meridionale alla fine, condizionando la ricaduta e l’accumulo dei piroclasti. il cratere presenta forma a semisfera, senza alcuna traccia che permetta di ubicare oggi le bocche descritte da silvestri (1867). il cono piroclastico ee (figg. 4 e 5) presenta una forma fortemente asimmetrica: la base ha un diametro massimo di 400 metri sviluppato in direzione e-w; alla sommità si riconoscono due archi di orli craterici con diametro di 100 metri e tre di minori dimensioni, allineati in direzione ene-wsw; il versante rivolto a occidente è alto meno di 10 metri, mentre quello di ese ha un dislivello di 80 metri e una lunghezza di 275 metri. questa forte asimmetria è da attribuire sia alla ricaduta balistica delle piroclastiti condizionata dalle condizioni meteorologiche, sia alla morfologia degli edif ici preesistenti, in parte distrutti dalle esplosioni, in parte ricoperti dai nuovi materiali piroclastici. l’intero edificio è interessato da profondi fenomeni erosivi, con riempimento delle cavità ed arretramento degli orli craterici. 66.. tteennttaattiivvoo ddii rriiccoossttrruuzziioonnee ddeellllaa mmoorrffoollooggiiaa pprreeeessiisstteennttee in mancanza di carte topografiche precedenti al 1865, la ricostruzione della morfologia preesistente all’eruzione può essere tentata sulla base dello studio delle fotografie aeree e degli scarsi documenti fotografici dell’epoca. un primo documento è la già citata fotografia pubblicata da silvestri (1867): gli edifici 11, 22 e 33 vi appaiono ricoperti da un rado bosco di pini, molti dei quali furono carbonizzati durante l’eruzione; se ne ricava che si tratta di edifici poligenici, collegati ad una fase di attività non datata di monte frumento delle concazze. a settentrione del cratere aa11 si trova una collina (figg. 4 e 5: ss) la cui sommità sovrasta di circa sei metri l’orlo del cratere suddetto; si tratta dei resti di un precedente edificio che si sviluppa per circa 120 metri verso settentrione, e le cui pendici meridionali sono state in parte smantellate dalle esplosioni, in parte ricoperte dalle piroclastiti emesse dalle bocche del cratere aa22. a meridione degli edifici bb, cc e dd affiorano i resti discontinui di tre orli craterici, relativi ad un 51 fig. 12 cineriti rappresentanti l’antico pavimento interno del cratere dell’edificio bb, in corrispondenza dell’orlo occidentale del cratere (m 1760). old crater pavement of volcanic building bb, near western crater rim (m 1760). fig. 11 bocca nuova” nel cratere dell’edificio bb,, vista dall’orlo sud-occidentale del cratere. new vent in volcanic building bb crater, seen from south-western crater rim. l’eruzione etnea del 1865 ... basso edificio quasi completamente ricoperto (figg. 4 e 5: tt, uu e ww). la colata γ è fuoriuscita da una bocca ubicata alla base meridionale del cratere uu (figg. 4 e 5). la forte asimmetria presentata dall’edificio ee è dovuta all’esistenza sotto il suo fianco orientale di un precedente edificio; altri due piccoli edifici allungati in senso e-w affiorano ai suoi piedi (fig. 13; figg. 4 e 5: yy e zz). 77.. ddiissccuussssiioonnee ddeeii ddaattii ee ccoonncclluussiioonnii il versante nord-orientale dell’edificio vulcanico etneo, sul quale si è verificata l’eruzione del 1865, è caratterizzato da faglie transtensive ne-sw e enewsw, con componente sinistra (neri et al., 1991), da alcuni attribuite a movimenti gravitazionali (borgia et al., 1992; lo giudice & rasà, 1992; mcguire et al., 1996), probabilmente agevolati dalle argille pleistoceniche del basamento etneo (carveni & bella, 1994; gresta et al., 1997; carveni et al., 1997). l’eruzione etnea del 1865 è una classica eruzione laterale (sensu rittmann, 1967); contrariamente però a quanto viene in genere segnalato in occasione di simili eruzioni dell’etna, dalle testimonianze dei precedenti autori non risulta che essa sia stata preceduta a breve distanza di tempo da una risalita magmatica lungo il condotto centrale: la precedente attività verificatasi al cratere centrale consistette nelle esplosioni del 7 e 8 luglio 1863 (grassi, 1865). la mancanza di attività al cratere centrale fa quindi supporre che il magma, senza raggiungere la parte sommitale del condotto centrale, si sia insinuato in una frattura radiale, o che la risalita magmatica sia avvenuta direttamente lungo un condotto secondario, indipendente, almeno in parte, da quello centrale. i sismi premonitori dell’eruzione, avvertiti prevalentemente nella zona compresa tra i monti arsi e i paesi di san giovanni e sant’alfio, sono da attribuire, a nostro avviso, a movimenti del tratto più settentrionale della faglia di moscarello e/o della faglia macchia stazzo (carveni & bella, 1994); il sisma concomitante all’ inizio dell’eruzione, avvertito negli stessi luoghi e propagatosi fino ad acireale, ma non a giarre e stazzo, conferma questa ipotesi. questa eruzione segna la ripresa dell’attività vulcanica in un settore dell’etna già interessato da eruzioni preistoriche, con progressivo spostamento verso se delle fratture eruttive; posteriormente al 1865 altre eruzioni sono avvenute nello stesso settore, sempre con spostamento verso se delle fratture di alimentazione (1928 e 1971). dalla distribuzione delle fratture eruttive, delle bocche e dei relativi depositi piroclastici, si evince che l’intrusione magmatica, nell’avanzare lungo la frattura radiale, che in superficie dava luogo al sistema principale di fratture eruttive, man mano che incontrava le fratture del sistema nnw-sse, risaliva anche attraverso queste. il primo sistema è parallelo alle strutture distensive riconosciute nel settore d’interesse (neri et al., 1991), e in special modo alle scarpate delle faglie della ripa della naca e della ripa di piscio. il secondo sistema è evidenziato da: l’allineamento delle fontane di lava (fig. 5: 44 ÷ 1111); l’allineamento delle bocche dei crateri aa11, aa22 e aa33 (figg. 4 e 5); l’analisi delle fotografie aeree che hanno messo in evidenza una serie di allineamenti morfologici con direzione nnw-sse, corrispondenti a faglie normali con labbro orientale ribassato; la testimonianza di silvestri (1867), che descrive fessure rettilinee le quali emettevano esclusivamente vapori (fig. 4 e 5: vviiii). questa serie di allineamenti risulta parallela alle faglie della zona delle timpe, le quali rappresentano, secondo lo giudice et al. (1982) il segmento più settentrionale della scarpata ibleo-maltese; lanzafame & bousquet (1997) attribuiscono un’importanza regionale a questa serie di faglie, che formano una delle più importanti strutture del mediterraneo centrale, il “sistema di faglie eoliano-maltese”. non sempre l’analisi delle caratteristiche morfologiche dei singoli coni fornisce dati inconfutabili per il riconoscimento delle fratture lungo cui è risalito il magma: infatti, mentre l’allineamento delle bocche 11 – 33 (fig. 4), l’allineamento degli spatter cone 44 1111 e l’allineamento dei crateri aa11 aa33 individuano senza ombra di dubbio fratture di alimentazione, le profonde svasature degli orli craterici degli edifici bb, dd ed ee non sono state causate da fenomeni di breaching (sensu tibaldi, 1995). inoltre si è riconosciuto che la morfologia dei coni piroclastici è stata influenzata prevalentemente dalle condizioni atmosferiche: a causa dei forti venti settentrionali che soffiarono per buona parte del mese di febbraio 1865 (silvestri, 1867), la ricaduta balistica delle 52 fig. 13 orlo craterico di un edificio preesistente all’eruzione (figg. 4 e 5: yy), sepolto in parte dall’edificio ee, visto da meridione. crater rim of volcanic building (figg. 4 e 5: yy) partially buried during 1865 eruption by buildind ee pyroclastics, seen from south. p. carveni & s. benfatto piroclastiti provocava una crescita asimmetrica degli edifici. infine, dalla ricostruzione della morfologia preesistente, risulta che i monti sartorius poggiano su un gruppo di edifici antecedenti, verosimilmente alimentati, almeno in parte, dalle stesse fratture eruttive. i risultati conseguiti portano a concludere, contrariamente a quanto affermato da nakamura (1977), che non sempre un vulcano poligenico è alimentato esclusivamente attraverso un condotto centrale: lo studio dell’eruzione etnea del 1865 dimostra inoltre che una risalita magmatica può avvenire attraverso fratture che hanno già dato luogo a precedenti eruzioni. infine, avendo constatato che i monti sartorius fanno parte di un sistema eruttivo poligenico, non si può escludere il verificarsi di nuove risalite magmatiche che diano luogo a ulteriori eruzioni. studio effettuato con i fondi del m.u.r.s.t., nell'ambito della ricerca "morfodinamica di zone vulcaniche e/o sismicamente attive", responsabile p. carveni. rriinnggrraazziiaammeennttii ringraziamo gli anonimi referees per gli utili e costruttivi consigli. rriiffeerriimmeennttii bbiibblliiooggrraaffiiccii adorni g. & carveni p. (1993 a) geomorphology and seismotectonic elements in the giarre area, sicily. earth surf. proc. land., 1188, 275-283. adorni g. & carveni p. (1993 b) anomalie del reticolo idrografico causate da eventi sismotettonici sul basso versante orientale dell’etna. boll. acc. gioenia sc. nat. catania, 2266 (342), 197-206. azzaro r., carveni p., lo giudice e. & rasà r. (1989 a) il terremoto di codavolpe (basso versante orientale etneo del 29 gennaio 1989: campo macrosismico e fratturazione cosismica). boll. g.n.v., 11, 1-12. azzaro r., lo giudice e. & rasà r. (1989 b) – catalogo degli effetti macrosismici e delle fenomenologie da creep nell’area etnea dall’agosto 1980 al dicembre 1989. boll. g.n.v., 11, 13-46. bella d., carveni p., musumeci c. & gresta s. (1996) aspetti geomorfologici conseguenti all'attività sismica locale sul basso versante orientale del vulcano etna. il quaternario, 99 (1), 365-368. borgia a., ferrari l. & pasquarè g. (1992) importance of gravitational spreading in the tectonic and volcanic evolution of mt. etna. nature, 335577, 231-235. bottari a., carveni p., lo giudice e., pietrafesa m., birritta g. & stillitani e. (1989) – criteri di utilizzo e rappresentazione grafica del dato macrosismico nella redazione di una carta sismotettonica. att. 8° conv. ann. gr. naz. geof. terra solida, 191-202. burollet p.f, mugnot g.m. & sweeney p. (1978) the geology of the pelagian block: the margins and basins of southern tunisia and tripolitania. in: nairn a., kanes w. & stelhi f.g., eds., the ocean basins and margins, plenum press, new york, 331-339. carapezza m. (1962) un esempio di eruzione laterale da faglia nell’apparato eruttivo etneo. acta geol. alpina, 8, 249-276. carbone m.s., cosentino m., grasso m., lentini f., lombardo g. & patanè g. (1982 a) elementi per una prima valutazione dei caratteri sismotettonici dell’avampaese ibleo (sicilia sud-orientale). mem. soc. geol. it., 2244, 507-520. carbone m.s., grasso m. & lentini f. (1982 b) considerazioni sull’evoluzione geodinamica della sicilia sud-orientale dal cretaceo al quaternario. mem. soc. geol. it., 2244,, 367-386. carveni p. & bella d. (1994) aspetti geomorfologici legati ad attività sismica su vulcani attivi: il basso versante orientale dell'etna come modello di studio. boll. acc. gioenia sc. nat., 27 (346), 253-285. carveni p., bella d., filetti g., leonardi m.c., musumeci c. & sturiale g. (1996) zonazione sismica del territorio di giarre (catania) mediante l'analisi di sismi locali avvenuti nel periodo 1855-1989. att. conv. lincei, "la stabilità del suolo in italia: zonazione sismica-frane", 113344, 389-393. carveni p., caruso v., pappalardo a. & sturiale g. (1998) aspetti morfo-strutturali e fenomenologie dell'eruzione etnea del 1865 (monti sartorius). att. 79° congr. naz. soc. geol. it., vol. a, 242-245. carveni p., caruso v., pappalardo a. & sturiale g. (2000) morpho-structural features and phenomenology of the 1865 eruption (monti sartorius) of mt. etna (sicily). mem. soc. geol. it., 5555, 389-395. carveni p., filetti g. & bella d. (1997) aspetti geomorfologici e sismologici connessi a fenomeni di tettonica gravitativa nel basso versante orientale dell'etna. geogr. fis. dinam. quat., 2200, 43-49. carveni p., romano r., caltabiano t., grasso m.f. & gresta s. (1994) – the exceptional explosive activity of 5 january 1990 at the se-crater of mt. etna volcano (sicily). boll. soc. geol. it., 111133, 613-631. casero p., cita m.b., croce m. & de micheli a. (1984) – tentativo di interpretazione evolutiva della scarpata di malta basata su dati geologici e geofisici. mem. soc. geol. it., 2277, 233-153. cassinis r., cosentino p., ponzini g.s. & riuscetti m. (1970) – contributo all’esplorazione geofisica lungo la costa etnea. att. conv. int. acque sotterranee, 6-8 dicembre 1970, palermo, 11 pp. cassinis r., franciosi r. & scarascia s. (1979) – the structure of the earth’s crust in italy. a preliminary typology based on seismic data. boll. geof. teor. appl., 8822, 105-126. ferrari l., garduno v.h., neri m. (1991) i dicchi della valle del bove, etna: un metodo per stimare le dilatazioni di un apparato vulcanico. mem. soc. geol. it., 4477, 495-508. ferrucci f. & patanè d. (1993) seismic activity accompanying the outbreak of the 1991-1993 eruption of mt. etna (italy). j. volcanol. geotherm. res., 5577, 125-135. ferrucci f., rasà r., gaudiosi g., azzaro r. & imposa s. (1993) mt. etna: a model for the 1989 eruption. jour. of volc. and geoth. res., 5566,, 35-56. finetti i. (1982) structure, stratigraphy and evolution of central mediterranean. boll. geof. teor. appl., xxvi, 9966, 247-312. finetti i., lentini f., carbone s., catalano s. & del ben a. (1996) il sistema appennino meridionale arco calabro sicilia nel mediterraneo centrale: studio geologico-geofisico. boll. soc. geol. it., 115, 529-559. finetti i. & morelli c. (1972) – wide scale digital seismic 53l’eruzione etnea del 1865 ... exploration of the mediterranean sea. boll. geof. teor. appl., 1144, 291-342. frazzetta g. & romano r. (1978) approccio di studio per la stesura di una carta del rischio vulcanico (etna-sicilia). mem. soc. geol. it., 1199, 691-697. frazzetta g. & villari l. (1981) the feeding of the eruptive activity of etna volcano. the regional stress field as a constraint to magma uprising and eruption. bull. volcan., 4444 (3), 269-282. ghisetti f. & vezzani l. (1982) the recent deformation mechanism of the calabrian arc. in: mantovani e. & sartoni r. (editors): structure, evolution and present dynamics of the calabrian arc. earth evolution sciences, 33, 197-206. giese p. & morelli c. (1975) crustal structure in italy. in: ogniben l., parotto m. & praturlon a. (editors), structural model of italy: maps and explanatory notes. quad. ricerca sci., 9900, 453-489. gillot p.y., kieffer g. & romano r. (1994) the evolution of mount etna in the light of potassium-argon dating. acta vulcanologica, 55, 81-87. grassi m. (1865) relazione storica ed osservazioni sulla eruzione etnea del 1865 e su’ tremuoti flegrei che la seguirono. stab. tipogr. c. galatola, catania, 92 pp. gresta s., bella d., musumeci c. & carveni p. (1997) some efforts on active faulting processes (earthquakes and aseismic creep) acting on the eastern flank of mt. etna (sicily). acta vulc., 99 (1/2), 101-108. kieffer g. (1975) sur l’existence d’une rift zone à l’etna. c.r. acad. sci., paris, 228800, d, 263-266. kieffer g. (1983 a) l’évolution structurale de l’etna (sicile) et les modalités du contrôle tectonique et volcano-tectonique de son activité. faits et hypothèses après les éruptions de 1978 et 1979. rev. géogr. phys. géol. dyn., paris, 2244 (2), 129-152. kieffer g. (1983 b) déplacement progressif vers l’est des voies d’alimentation magmatiques de l’etna (sicile). bull. soc. géol. fr., 2255 (3), 369-378. lanzafame g. & bousquet j.c. (1997) the maltese escarpment and its extension from mt etna to the aeolian islands (sicily): importance and evolution of a lithosphere discontinuity. acta vulcanologica, 99, 121-133. lo giudice e., patanè g., rasà r. & romano r. (1982) the structural framework of mt. etna. mem. soc. geol. it., 2233, 125-158. lo giudice e. & rasà r. (1992) very shallow earthquakes and brittle deformations in active volcanic areas: the etnean region as an example. tectonophysics, 220022, 257-268. marchesini e., conedera c., morabito g. & macii l. (1964) studio fotogeologico dell'etna. riv. min. sic., 8855--8877, 83-95. mcguire w.j., moss j.l., saunders s.j. & stewart i.s. (1996) dykeinduce rifting and edifice instability at mount etna. proc. conf. "etna: fifteen years on", london, february 12, 1996, 20-24. monaco c., petronio l. & romanelli m. (1995) tettonica estensionale nel settore orientale del monte etna (sicilia): dati morfotettonici e sismici. studi geologici camerti, convegno geodinamica e tettonica attiva del sistema tirreno-appennino, 363-374. monaco c., tapponnier p., tortorici l. & gillot p.y. (1997) late quaternary sl ip rates on the acireale-piedimonte normal faults and tectonic origin of mt. etna (sicily). earth planet. sc. lett., 114477, 125-139. monaco c. & tortorici l. (1995) tettonica estensionale quaternaria nell’arco calabro e in sicilia orientale. studi geologici camerti, convegno geodinamica e tettonica attiva del sistema tirreno-appennino, 351-362. morelli c. (1970) physiography, gravity and magnetism of the tyrrhenian sea. boll. geofis. teor. appl., 12: 275-305. nakamura k. (1977) volcanoes as possible indicators of tectonic stress orientation – principle and proposal. j. volcanol. geotherm. res., 22, 1-16. nakamura k., jacob k.h. & davies j.n. (1977) volcanoes as possibile indicators of tectonic stress orientation: aleutians and alaska. pageoph., 111155, 87-112. neri m., garduno v.h., pasquarè g. & rasà r. (1991) studio strutturale e modello cinematico della valle del bove e del settore nord-orientale etneo. acta vulcanologica, 11, 17-24. ogniben l., parotto m. & praturlon a. (1975) structural model of italy. c.n.r., quaderni de “la ricerca scientifica”, 9900, 502 pp. postpischl d., editor, (1985) catalogo dei terremoti italiani dall’anno 1000 al 1980. pr. fin. geod. c.n.r., quaderni de la ricerca scientifica, 111144-2°, bologna. rittmann a. (1967) i vulcani e la loro attività, cappelli, 360 pp. rittmann a., romano r. & sturiale c. (1973) some considerations on the 1971 etna eruption and on the tectonophysics of the mediterranean area. geol. rund., 6622 (2), 418-430. romano r. (1970) tectonic control on magmatic differentiation: an example. bull. volc., 3344 (4), 823-832. romano r. (1982) succession of the volcanic activity in the etnean region. mem. soc. geol. it., 2233, 27-48. romano r., lentini f., sturiale c., amore c., atzori p., carter s.r., cristofolini r., di geronimo i., di grande a., duncan a.m., ferrara v., ghisetti f., guest j.e., hamill h., patanè g., pezzino a., puglisi d., schilirò f., torre g. & vezzani l. (1979) carta geologica del monte etna, scala 1:50.000, litogr. art. cartogr., firenze. romano r. & sturiale c. (1982) the historical eruptions of mt. etna (vol-canological data). mem. soc. geol. it., 2233, 75-97. scandone p. (1982) geology of the calabrian arc. in: mantovani e. & sartori r. (editors): structure, evolution and present dynamics of the calabrian arc. earth evolution sciences, 3: 172-180. selli r. & fabbri a. (1971) tyrrhenian: a pliocene deep sea. rend. cl. fis. mat. nat. accad. lincei, 88, 104-116. silvestri o. (1867) i fenomeni vulcanici presentati dall’etna nel 1863-64-65-66, considerati in rapporto alla grande eruzione del 1865. mem. acc. gioenia sc. nat., serie iii, 11, 53-319. tibaldi a. (1995) morphology of pyroclastic cones and tectonics. j. geophys. res., 110000, 24521-24535. van bemmelen r.w. (1969) origin of the western mediterranean sea. verh. k. -ned. geol. mijnbouwkd. genoot., geol. ser., 2266, 13-52. 54 ms. ricevuto il 1° luglio 2003 testo definitivo ricevuto il 20 gennaio 2004 ms. received: july 1, 2003 final text received: genuary 20, 2004 p. carveni & s. benfatto dinamica recente ed attuale di alvei fluviali: alcuni casi di studio appenninici (italia centro-settentrionale) massimo rinaldi, liliana b.teruggi, cristina simoncini & laura nardi dipartimento di ingegneria civile e ambientale, università di firenze e-mail: mrinaldi@dicea.unifi.it riassunto: m. rinaldi et al., dinamica recente ed attuale di alvei fluviali: alcuni casi di studio appenninici (italia centro-settentrionale) (it issn 0394-3356, 2008). vengono analizzate e discusse le variazioni morfologiche recenti (ultimi 100 anni circa) e le tendenze attuali di tre casi di studio rappresentativi dell'appennino centro settentrionale: (1) fiume magra e suo principale affluente, fiume vara, relativi all'area appenninica compresa tra toscana settentrionale e liguria; (2) fiume panaro, rappresentativo del versante padano dell'appennino toscoemiliano; (3) fiume cecina, rappresentativo della toscana meridionale. tale studio è finalizzato principalmente ai seguenti obiettivi: (1) estendere le attuali conoscenze sull'evoluzione recente di alvei fluviali italiani a nuovi casi di studio dell'appennino centro-settentrionale; (2) confrontare tali casi tra loro per definirne gli aspetti evolutivi comuni e le differenze eventualmente da attribuirsi a particolari contesti geomorfologici e/o ad impatti antropici specifici. sono stati presi in esame i seguenti aspetti: (1) ricostruzione degli interventi antropici diretti ed indiretti per valutare il loro possibile ruolo nei confronti delle variazioni morfologiche degli alvei; (2) analisi delle variazioni morfologiche degli alvei: sono state acquisite ed analizzate tramite gis le cartografie e le foto aeree disponibili, in modo da permettere un confronto degli alvei in diversi anni e consentire la misura dei parametri planimetrici (larghezza dell'alveo, sinuosità, indice di intrecciamento), ed i rilievi topografici esistenti per ricostruire le variazioni di quota del fondo; (3) rilevamento geomorfologico di campo, attraverso l'applicazione di apposite schede focalizzate sull'interpretazione e la classificazione delle variazioni e delle tendenze attuali. i risultati possono essere sintetizzati come segue: (1) tutti i casi di studio sono stati interessati da abbassamento del fondo, con i casi di incisione più intensa (fino a valori di 7-10 m) registrati per il f. panaro e per il f. magra nel suo tratto inferiore; (2) analogamente, tutti i corsi d'acqua analizzati hanno subito un restringimento dell'alveo attivo; (3) si possono generalmente distinguere due fasi di aggiustamento morfologico (restringimento incisione), con la fase più intensa compresa tra gli anni '50 e i primi anni '90; (4) tali variazioni morfologiche sono fortemente correlate a fattori antropici, con rapporti causa effetto chiari e con modifiche di maggiore entità avvenute nei fiumi soggetti a maggiore impatto; (5) durante gli ultimi 10-15 anni circa, si osserva in alcuni casi una inversione di tendenza della larghezza (fase di allargamento, ad eccezione del f. cecina che continua nella sua fase di restringimento), accompagnata talora da situazioni di sedimentazione; (6) gli ultimi dati (2006/07) indicano in alcuni di questi casi una nuova lieve riduzione di larghezza. abstract: m.rinaldi et al., recent and present dynamics of river channels: some study cases from the apennines (central-northern italy. (it issn 0394-3356, 2008). during the last decades and centuries, many fluvial systems of the world have been heavily impacted by various types of human disturbances. regarding the italian rivers, a bibliographic review carried out by surian & rinaldi (2003) pointed out two main types of channel adjustments (incision and narrowing) and proposed a classification scheme of the types and amount of channel adjustments. from more recent studies (surian & rinaldi, 2004) it is emerging that an inversion of trend in width adjustments (widening) and/or in bed-level adjustments (aggradation) have recently occurred in some study cases. notwithstanding recent progress, there still remains the need to describe these processes more accurately and for a larger number of study cases. the research project prin 2005 "present and recent dynamics of river channels in northern and central italy: evolutionary trends, causes and management implications" has this general aim. this paper deals with changes and evolutionary trends of river channels in the northern apennines. the two main objectives of this research are: (1) to extend the knowledge of channel adjustments to new study cases in the northern apennine; (2) to compare such study cases to define common trends of adjustments and differences eventually related to different geomorphic contexts and human impacts. the following study cases have been selected, in order to represent different situations in the geographical context of central-northern apennines: (1) magra river and its main tributary, vara river; (2) panaro river; (3) cecina river, as a representative case of watershed located in southern tuscany. the following main aspects were investigated in detail: 1. reconstruction of human interventions and disturbances in order to verify their possible role on the channel adjustments. 2. analysis of channel changes. most of the available maps and aerial photos were acquired and analysed in gis, with the aim to allow for comparisons and measurements of the planimetric parameters (channel width, sinuosity, braiding index). then, a reconstruction of bed-level changes through the comparison of topographic surveys from different years was carried out. 3. field surveys. a series of forms for geomorphological field surveys were developed and applied to the study cases with a particular focus on the interpretation and classification of channel adjustments. the main results can be summarised as follows: (1) all study cases have been affected by channel bed incision, with the highest bedlevel lowering (up to 7-10 m) recorded along the panaro river and the lower part of the magra river; (2) similarly, all study cases have been affected by channel narrowing; (3) two phases of channel adjustment (incision narrowing) can be distinguished, with the phase of major changes occurring between about '50s and the beginning of '90s; (4) such changes appear strongly connected to human factors, with quite evident cause-effect relations, and with the highest changes occurring along the rivers with strong human impact; (5) during the last 10-15 years, an inversion of trend of channel width is observed (widening phase, except for the cecina river where the phase of channel narrowing is still continuing), coupled in some cases with situations of aggradation; however, during the last years (2006/07) a slightly new reduction in channel width is observed in some cases. parole chiave: variazioni morfologiche di alvei fluviali, fiumi italiani, impatti antropici keywords: channel adjustments, italian rivers, human impacts il quaternario italian journal of quaternary sciences 21(1b), 2008 291-302 292 m. rinaldi et al. 1. introduzione durante gli ultimi secoli, la maggior parte dei fiumi italiani è stata fortemente impattata da vari tipi di disturbi antropici e molti di questi corsi d'acqua stanno tuttora modificando, come risposta a tali impatti, la propria forma e le proprie dimensioni. tale dinamicità morfologica può determinare problemi in termini di rischi da dinamica d'alveo (danni a centri abitati, infrastrutture, perdita di terreni, possibili esondazioni connesse a processi di sedimentazione) ma, in molti casi, può avere effetti benefici per gli ecosistemi, promuovendo spontaneamente la diversificazione di habitat. pertanto la conoscenza delle tendenze evolutive dei corsi d'acqua è fondamentale sia ai fini della protezione e della sicurezza che in termini di gestione e riqualificazione fluviale. per quanto riguarda i fiumi italiani, esiste già una certa conoscenza delle variazioni morfologiche avvenute nel corso degli ultimi 100 150 anni. gli studi al riguardo partono da fine anni '70 inizi anni '80 (ad es. ca s t i g l i o n i & pe l l e g r i n i, 1981) e sono sempre più numerosi negli anni successivi (si veda ad es. braga & ge r v a s o n i, 1989; ca s t a l d i n i & pi a c e n t e, 1995; su r i a n, 1999; marchetti, 2002). surian & rinaldi (2003) hanno effettuato una rassegna di tutte le conoscenze acquisite sull'argomento, delineando i principali tipi di variazioni osservate in fiumi italiani e definendo uno schema generale di evoluzione. in alcuni casi (ad es. rinaldi & simon, 1998; rinaldi, 2003) è stata ben evidenziata l'esistenza di due principali fasi di aggiustamento morfologico: (a) da fine 1800 a metà del 1900, con incisioni e restringimenti meno intensi e legati soprattutto a fattori a scala di bacino; (b) seconda metà del 1900, con modifiche più forti legate soprattutto ad interventi ed attività in alveo. meno approfondite risultano essere invece le conoscenze relative alle attuali tendenze evolutive dei corsi d'acqua italiani. da alcuni autori (su r i a n & ri n a l d i, 2004; ri n a l d i et al. , 2005a), limitatamente a qualche caso di studio, è stata osservata preliminarmente una inversione di tendenza delle larghezze e, in alcuni casi, delle quote del fondo. a seguito di questi studi, è maturata quindi la necessità di un approfondimento, descrivendo più accuratamente le variazioni passate ed attuali e per un numero più ampio di casi di studio, esigenze dalle quali è scaturito il progetto prin 2005 “dinamica recente ed attuale di alvei fluviali in italia centro-settentrionale: tendenze evolutive, cause ed implicazioni applicative”. in questo articolo si riportano sinteticamente i principali risultati relativi a tre casi di studio inclusi in questo progetto (relativamente al l'u.o. di firenze), con i seguenti obiettivi: (1) estendere le attuali conoscenze sull'evoluzione recente di alvei fluviali italiani a nuovi casi di studio dell'appennino centro-settentrionale; (2) confrontare tali casi tra loro per definirne gli aspetti evolutivi comuni e le differenze eventualmente legate a contesti geomorfologici differenti e sia agli impatti antropici specifici. 2. casi di studio 2.1 inquadramento generale dei bacini i tre bacini di studio sono ubicati nell'italia centro settentrionale (fig. 1) e sono stati scelti in modo da essere sufficientemente rappresentativi di aree con condizioni morfologico climatiche relativamente diverse all'interno dell'appennino settentrionale. in tabella 1 sono riepilogate le principali caratteristiche morfologiche ed idrologiche dei tre bacini. il bacino del fiume magra è rappresentativo del versante appenninico ligure e della toscana settentrionale. esso ha una estensione di circa 1698.5 km2 ed è costituito da un sistema di due vallate tra loro parallele: ad occidente la valle del fiume vara, suo principale affluente (la cui area si estende per 572 km2), ad oriente l'alta media valle del fiume magra. le litologie affioranti nel sottobacino del vara sono a costituzione prevalentemente arenacea ed in subordine argillitico-marnosa, alle quali si aggiungono litologie calcaree ed in subordine metamorfiche magmatiche (versante nw delle alpi apuane) nel bacino del magra. il fiume panaro è scelto come rappresentativo del figura 1 bacini e tratti di studio. a: bacino del f. magra; b: bacino del f. panaro; c: bacino del f. cecina. 1: tratti di studio; 2: stazioni di misura idrometriche presenti lungo il f. magra e f. cecina. catchments and study reaches. a: magra r. catchment; b: panaro r. catchment; c: cecina r. catchment. 1: study reaches; 2: gauging stations along magra and cecina rivers. versante padano dell'appennino tosco-emiliano. il bacino ha una estensione di circa 1783 km2, simile quindi a quella del f.magra, con una forma spiccatamente allungata in direzione sw-ne. la fascia collinare e montuosa è interessata da litologie prevalentemente arenacee ed argilloso marnose, mentre la fascia di pianura è costituita da depositi recenti prevalentemente alluvionali. il fiume cecina è scelto come rappresentativo della toscana centro meridionale, e si diversifica dagli altri casi anche per le condizioni climatiche leggermente differenti, presentando caratteristiche più marcate di clima mediterraneo (temperato piovoso con estate asciutta e calda). il bacino ha una estensione di circa 905 km2, quindi è di dimensioni significativamente inferiori rispetto agli altri due casi; presenta un rilievo prevalentemente collinare, con rilievi meno accentuati rispetto alla catena appenninica. le porzioni più alte sono costituite da rocce prevalentemente calcareo argillitiche, mentre la fascia collinare ed il fondovalle sono impostati in litotipi prevalentemente di natura pelitica costituiti da depositi lacustri, marini e fluviali dei complessi neogenico quaternari. 293dinamica recente ed attuale di alvei ... 2.2 caratteristiche morfo-sedimentarie degli alvei fluviali sulla base di una prima osservazione delle foto aeree e di una ricognizione di campo iniziale, ognuno dei tre corsi d'acqua studiati è stato suddiviso in una serie di tratti con caratteristiche morfologiche relativamente omogenee, con particolare riferimento ai due seguenti aspetti: (a) morfologia del fondovalle (ampiezza, direzione della valle e grado di confinamento del fiume); (b) morfologia planimetrica dell'alveo. in particolare, sono stati in primo luogo distinti i principali tratti (ad es. ma, mb, …, me per il f.magra), in base prevalentemente alla morfologia del fondovalle, e successivamente ogni tratto è stato ulteriormente suddiviso in sottotratti (ad es. mb1, mb2, …, me1, me2) considerando con maggior dettaglio la forma planimetrica dell'alveo e le discontinuità idrologiche naturali in relazione alla presenza dei maggiori affluenti. l'analisi delle variazioni morfologiche, in particolare di quelle di larghezza, si è successivamente concentrata solo su alcuni di questi tratti o sottotratti (tab. 2) che presentassero le seguenti caratteristiche: (1) alvei alluvionali a fondo mobile senza significative costrizioni naturali da parte tabella 1 caratteristiche morfologiche ed idrologiche generali dei bacini di studio. a: area del bacino (in parentesi l'area sottesa dalla stazione di misura delle portate); l: lunghezza del fiume; δh: dislivello del bacino; p: precipitazioni medie annue; qmed: portata giornaliera media annua; qmax: portata massima. general morphological and hydrological characteristics of the study basins. a: drainage basin area (in parentheses the drainage basin areas upstream of the gauging stations to which the discharges are referred); l: river length; δh: basin relief; p: mean annual rainfall; qmed: mean annual daily discharge; qmax: maximum peak discharge. fiume a (km2) l (km) δh (m) p (mm) qmed (m3/s) qmax (m3/s) magra 1698.5 (932) 69.5 1639 1707 40.8 1440 vara 572 (205) 65 1603 1770 8.3 518 panaro 1783 (1036) 165 2157 1017 19 1400 cecina 905 (634) 53 1018 944 7.6 1030 tabella 2 caratteristiche morfologico sedimentarie generali dei tratti di studio. general morphological sedimentary characteristics of the study reaches. fiume lunghezza morfologia alveo pendenza fondo d50 sedimenti tipi di sponde tratto di studio (%) fondo (mm) (km) magra superiore 10 transizionale 0.86 0.95 45.3 90.9 principalmente non coesive (mb) (wandering) media: 0.9 media: 62.3 (ghiaia grossolana) magra inferiore 11 transizionale 0.15 0.42 20.9 39.7 principalmente composite (md2-me1) (wandering) media: 0.24 media: 29.4 (ghiaia basale, livello coesivo superiore) vara medio22 sinuoso (vc2-vd) 0.28 0.47 12.4 52.3 da non coesive (ghiaia inferiore transizionale media: 0.37 media: 38.4 grossolana) (vc2-vd) a (vc2-vd, ve) (wandering) (ve) composite (ghiaia basale, livello coesivo superiore) (ve) panaro medio 38 da transizionale 0.05 0.4 27.1 90.0 da composite (ghiaia basale, (pa, pb, pc) (pa) a sinuosomedia: 0.2 media: 49.0 livello coesivo superiore) meandriforme (pc) a coesive cecina medio40 transizionale 0.21 0.5 11.6 34.4 da non coesive (ghiaia) a inferiore (wandering media: 0.3 media: 18.1 composite (ghiaia basale, (cb, cc, cd1) sinuoso con barre livello coesivo superiore) alternate) dei versanti (alvei non confinati); (2) sono stati evitati tratti eccessivamente controllati da opere idrauliche (in particolare i tratti finali di tutti e tre i casi di studio: pd, me2, cd2) per i quali le variazioni planimetriche fossero state condizionate o completamente impedite dalla presenza di sponde fisse. e' stata effettuata una campagna di misura delle granulometrie dell'alveo, ai fini di una caratterizzazione generale delle dimensioni granulometriche e delle loro variazioni spaziali. le misure sono state condotte attraverso il metodo di campionamento statistico (p e bble counts) (wolman, 1954; bunte & abt, 2001), con stendimenti effettuati sulle superfici di barre attive emerse. tali misure hanno riguardato l'intera lunghezza dei fiumi magra, vara e cecina (per lunghezze dell'ordine dei 40-50 km), mentre per il f.panaro i rilievi granulometrici sono stati limitati ai tratti pa e pb (lunghezza di circa 20 km). il principale risultato di tali misure, in termini di variazioni spaziali del diametro mediano dei sedimenti (d50), è riportato in figura 2: si osservano delle oscillazioni relativamente forti, rispetto al trend discendente verso valle, riconducibili principalmente agli apporti laterali e, nel caso del panaro, alla presenza di numerose opere trasversali. il range di variabilità generale è compreso tra i 10 e 90 mm circa, con i sedimenti relativamente più fini presenti lungo il f.cecina (d50 compresi tra 13.7 e 45.3 mm). un riepilogo delle caratteristiche morfologiche e sedimentarie complessive dei tratti di studio è riportato in tabella 2. e' possibile notare come i tratti di studio presentino caratteristiche simili in termini di morfologie, con prevalenza di tipologie transizionali (wandering o sinuoso a barre alternate), eccetto per il tratto inferiore del panaro (pc), caratterizzato da una morfologia a canale singolo sinuoso-meandriforme. le pendenze del fondo sono piuttosto variabili, con valori dell'ordine di 0.004 0.009 nei tratti medio alti (mb, pa, cb) a valori dell'ordine di 0.0005 0.002 nei tratti inferiori (me, pc, cd). 2.3 impatti antropici in tabella 3 si riporta un quadro riepilogativo dei 294 figura 2 andamento spaziale del diametro mediano dei sedimenti lungo i fiumi studiati. spatial trend of median diameter of bed sediments along the study rivers. tabella 3 riepilogo dei principali tipi di impatti antropici e relative epoche per i casi di studio. summary of the main human impacts and relative periods for the study cases. fiume dighe e area del opere trasversali periodo di costruzione di rimboschimenti sistemazioni bacino a monte (soglie, briglie, intensa argini e di nel bacino idraulico(%) traverse) nei tratti escavazione protezioni forestali nel di studio di sedimenti di sponda bacino magra 3 piccole dighe alcune traverse nel anni '60 '70 dagli anni '20 primi decenni primi decenni lungo affluenti tratto inferiore realizzazione di del xx secolo del xx secolo (metà del xx (seconda metà pennelli lungo i secolo) per energia xx secolo) tratti inferiori idroelettrica: area (md2-me1) a monte circa 4 % vara 1 diga nel tratto soglie nel tratto anni '60 '70 dagli anni '20 primi decenni primi decenni medio (anni '30): inferiore (ve) realizzazione di del xx secolo del xx secolo area a monte 43 % (anni '80) pennelli lungo il tratto inferiore (ve) panaro 1 piccola diga numerose briglie nel anni '60 '90 anni '20 '60 primi decenni primi decenni lungo affluente tratto medio (pa, pb) del xx secolo del xx secolo, (metà del xx (principalmente anni continuati fino a secolo): area a '70 '80) e opera fine anni '80 monte circa 3 % derivazione cassa di espansione (pc) (anni '80) cecina alcune traverse nel anni '70 argini e pennelli primi decenni primi decenni tratto medio inferiore discontinui durante del xx secolo del xx secolo (xix e xx secolo) i primi decenni del xx secolo lungo il tratto medioinferiore (cc, cd) m. rinaldi et al. principali tipi di interventi e disturbi antropici che hanno potuto avere influenza sulla dinamica fluviale dei corsi d'acqua studiati nel periodo di indagine. tutti i casi di studio sono stati interessati in linea di massima dagli stessi tipi di impatti, ad eccezione delle dighe e delle opere trasversali lungo i tratti di studio, assenti solo nel caso del f. cecina l'impatto più forte è stato senza dubbio l'intensa escavazione di sedimenti soprattutto lungo il f. panaro, in tutto il tratto di studio, e lungo i tratti inferiori del f. vara e soprattutto del f. magra, a valle della loro confluenza. alcuni dati possono risultare utili per meglio comprendere l'impatto rilevante prodotto da tale attività. per quanto riguarda i fiumi magra e vara, è stato stimato che i quantitativi estratti complessivamente nei loro tratti vallivi tra 1958 e 1973 si aggiri attorno a 24.400.000 m3 (cavazza & pregliasco, 1981), a fronte di un trasporto solido al fondo medio annuo, per il tratto inferiore del f. magra, che è stato stimato essere dell'ordine di 30.000 36.000 m3/anno (cavazza & preglias c o, 1981; ri n a l d i, 2007). nel caso del f. panaro, il periodo di massima intensità delle escavazioni è stato tra il 1960 ed il 1980, con quantitativi estratti, secondo i dati ufficiali, di circa 5.900.000 m3 tra 1962 e 1980, e con il picco annuo raggiunto nel 1973 con 720.000 m3 circa. non esistono stime sul trasporto solido di questo corso d'acqua, ma certamente il rapporto tra tassi di escavazione e di trasporto al fondo, dal quale dipende molto il tipo e l'intensità della risposta morfologica dell'alveo (ri n a l d i et al., 2005b), sono anche in questo caso molto elevati. per quanto riguarda il f. cecina, non esistono dati o informazioni precise relative a questa attività. si può certamente affermare che tale fiume è stato meno interessato dall'escavazione di sedimenti, rispetto ai casi precedenti, e che questa attività si è comunque concentrata durante i primi anni '70, in concomitanza con la realizzazione di varie infrastrutture e vie di comunicazione nelle aree limitrofe. 3. dati raccolti e metodi un riepilogo di tutti i dati e materiali utilizzati è riportato in tabella 4. i metodi impiegati consistono in: (a) confronto di cartografie storiche e foto aeree; (b) confronto dei rilievi topografici; (c) rilevamenti geomorfologici di campo. le foto aeree sono state elaborate attraverso il software arcgis (arcinfo), il quale ha permesso di rettificare e georeferenziare le immagini in modo da poterle sovrapporre tra loro ed effettuare le misure dei parametri di interesse. per ogni anno disponibile, è stato tracciato l'asse dell'alveo attivo e sono state definite sezioni ad esso ortogonali con passo variabile a seconda dei casi di studio. per quanto riguarda i fiumi vara e magra, si sono in parte utilizzate misure già effettuate in studi precedenti (ri n a l d i et al., 2005a; ri n a l d i, 2005) per i quali sono state impiegate le sezioni topografiche del 1989, aventi un passo di 200 250 m circa, pari a circa da 1 a 2 volte la larghezza dell'alveo attuale. per il f. panaro ed il f. cecina si è preferito effettuare le misure con un passo rispettivamente di 50 m e 40 m, cioè pari a circa da 0.5 a 1 volta la larghezza attuale. e' stata misurata sia la larghezza totale, comprensiva cioè di eventuali isole vegetate, che la larghezza dell'alveo attivo, escluse le isole. per tutti i casi di studio sono state utilizzate anche carte storiche le quali, seppure con un margine di errore superiore rispetto alle foto aeree, sono state ritenute sufficientemente attendibili, nonché fondamentali per la comprensione dei trend di larghezza di più lungo termine e soprattutto per ricavare una stima della larghezza iniziale del periodo investigato. per quanto riguarda i dati altimetrici, la ricostruzione delle variazioni di quota del fondo è stata effettuata limitatamente ad alcuni tratti dei fiumi magra e vara per i quali erano disponibili rilievi topografici relativi ad anni diversi. per quanto riguarda i rilievi geomorfologici di campo, sono state utilizzate le schede di rilevamento descritte da rinaldi (2008) o, per i fiumi magra e vara, versioni precedenti delle stesse (ri n a l d i, 2005). tali schede hanno permesso, oltre alla descrizione delle caratteristiche morfologiche generali, anche di classificare le variazioni altimetriche di periodi precedenti, in base a differenze di quota tra superfici omologhe, e di 295 tabella 4 riepilogo dei dati utilizzati. summary of data used. dati f. magra f. vara f. panaro f. cecina cartografie storiche (scala) 1823 (1:50.000), 1852 1890 (1:25.000 1:50.000) 1883 (1:50.000) (1:50.000), 1877 (1:50.000), 1908 (1:25.000) foto aeree o cartografie 1937/38 (1:18.000), 1954 1934/35 (1:25.000) 1954 (1:33.000) (scala) (1:66.000), 1971 (1:66.000), 1954/55 (1:33.000) cd1: 1976 (1:15.000) 1981 (1:66.000), 1992 1962/69 (1:5.000) 1986 (1:15.000) (1:66.000), 1995 (1:40.000), 1981 (1:33.000) 1994 (1:33.000) 1999 (1:40.000) 1997 (1:15.000) 1999 (1:40.000) 2003/04 (1:33.000) 2000 (1:40.000) 2004 (1:7.500) mb, md, me: 2006 (1:8.000) pb: 2007 (1:7.000) rilievi topografici mb: 1989, 2006 1991 2004 md-me: 1914, 1958, 1971, 1989, 1999/200, 2006 vd-ve: 1958, 1971, 1989, 1999/2000 rilievi geomorfologici e 2003/06 2006/07 2005/07 sedimentologici dinamica recente ed attuale di alvei ... valutare le tendenze attuali, in base ad una serie di variabili appositamente definite (quali differenze altimetriche tra superfici, caratteristiche delle barre, corazzamento e caratteristiche tessiturali dei sedimenti, evidenze vegetazionali, ecc.). 4. variazioni morfologiche 4.1 variazioni planimetriche i trend temporali di variazioni di larghezza sono riportati in figura 3a, dove si confrontano tra loro i dati relativi a tutti i sottotratti dei casi di studio analizzati. la prima osservazione di carattere generale che si può effettuare è la progressiva riduzione di larghezza nel tempo, almeno fino alla fine degli anni '90 circa: per i sol i casi del basso magra (md2 ed me1), si nota nel 1954 un temporaneo incremento di larghezza rispetto al dato precedente (1938). dalla fine degli anni '90 in poi si nota qualche caso di inversione di tendenza con un lieve incremento di larghezza, o comunque una situazione di maggiore equilibrio. al fine di rendere meglio confrontabili tra loro i risultati, in un secondo grafico la larghezza è stata adimensionalizzata rispetto al valore massimo registrato nel periodo (fig. 3b) (quest'ultimo associato sempre al primo valore di larghezza misurato sulle carte storiche). da tale grafico è possibile più agevolmente identif icare le fasi di aggiustamento generalizzabili o meno a tutti i casi di studio. infine, nella figura 3c si riportano i tassi medi di variazione per ognuna delle fasi di evoluzione, ed in tabella 5 si riporta un riepilogo delle caratteristiche principali delle varie fasi. si riepilogano di seguito le caratteristiche generali delle varie fasi: (1) prima fase di restringimento (fase 1): caratterizzata da un restringimento molto significativo, verificatosi nella maggior parte dei casi tra fine 1800 inizi 1900 e anni '50 inizi anni '70; (2) seconda fase di restringimento (fase 2): caratterizzata da un restringimento altrettanto 296 figura 3 variazioni di larghezza. a: trend temporali delle larghezze. b: andamento delle larghezze (l) adimensionalizzate rispetto alla larghezza massima (lmax) del periodo di misure. c: tassi di variazione medi (δl/t) per le varie fasi di aggiustamento morfologico. i simboli rappresentano il tasso di variazione attribuito al punto medio dell'intervallo di tempo, quest'ultimo rappresentato dalla linea. changes in channel width. a: temporal trends of channel width changes. b: trend of channel widths (l) nondimensionalised by the maximum width of the period (lmax). c: mean rates of width change (δl/t) for each of the phases of channel adjustments. symbols represent the rates associated to the mean point of the time intervals, the latter represented by the lines. m. rinaldi et al. significativo ma, essendosi manifestato in un intervallo di tempo inferiore, con tassi di variazione in genere più elevati. nella maggior parte dei casi la fase 2 si è manifestata dalla fine della precedente a fine anni '90; (3) fase di allargamento (fase 3): non è sempre presente, in quanto alcuni tratti sono tuttora in restringimento. quando presente, è iniziata a fine anni '90 ed è caratterizzata da un aumento di larghezza, con tassi in alcuni casi anche molto significativi, oppure da un aumento seguito poi da una nuova riduzione (ma il cui valore finale è comunque maggiore rispetto al minimo raggiunto alla fine della fase 2). rispetto a tale modello generale, si rimarcano di seguito alcuni dei principali discostamenti: (1) per il f. panaro nel tratto pb, la fase 2 di restringimento è ancora in atto, dopo una lieve inversione di tendenza tra 1997 e 2000. per i tratti pa e pc non è stato possibile verificare se esistesse tale restringimento in quanto non era disponibile il volo aereo 2007, per questo motivo l'esistenza di una effettiva fase 3 di riallargamento è incerta. (2) il f. cecina rappresenta un caso che si discosta ulteriormente dagli altri, in quanto: (a) la fase 1 si prolunga fino a fine anni '80 inizi anni '90; (b) analogamente al tratto pb, la fase 2 di restringimento è ancora in atto in tutti e tre i tratti di studio (cb, cc e cd1). in sintesi, sembra che le fasi evolutive lungo il f. cecina si siano verificate e si stiano tuttora verificando con un certo sfasamento (ritardo) rispetto al modello generale. 4.1 variazioni altimetriche in tabella 6 si riporta un riepilogo delle variazioni di quota del fondo rispetto a fine 1800, stimate sulla base dei rilievi topografici disponibili (f. magra e f. vara) o valutate in base ad osservazioni di campo. si osserva come i valori più alti di abbassamento si registrano lungo il tratto inferiore del f. magra e lungo tutti i tratti di studio del f. panaro, laddove è stata più forte l'attività di escavazione di sedimenti durante i decenni passati. i valori più contenuti di abbassamento sono invece osservati lungo i tratti medi del f. vara e del f. cecina. per quanto riguarda le tendenze attuali, eccetto per il f. magra per il quale erano disponibili rilievi topografici eseguiti negli ultimi 10 anni, in tutti gli altri casi le valutazioni si sono basate esclusivamente su osservazioni di campo, le quali non sono in grado di fornire delle stime ma solo di classificare la tendenza prevalente. in generale si sono osservate prevalentemente situa297 fiume tratto variazioni stimate rispetto a fine 1800 tendenze attuali (ultimi 10 anni circa) magra mb 2 4 m equilibrio / sedimentazione md2-me1 5 8 m equilibrio / sedimentazione vara vc2-vd 1 3 m equilibrio / sedimentazione ve 2 4 m equilibrio / sedimentazione panaro pa 4 6 m equilibrio pb 6 10 m equilibrio pc 4 6 m equilibrio cecina cb 1 2 m equilibrio (sedimentazione) cc-cd1 2 3 m equilibrio (sedimentazione) tabella 5 riepilogo delle variazioni di larghezza suddivise per fasi evolutive. t1, t2 e t3: intervalli di tempo relativi alle fasi 1, 2 e 3 rispettivamente; δl: variazione di larghezza; δl/(lmax-lmin): rapporto tra variazione di larghezza in una fase evolutiva e differenza tra larghezza massima e minima dell'intero periodo. summary of channel width changes for each phase of evolution.t1, t2, t3: time intervals of the phases 1, 2, and 3 respectively; δl: width change; δl/(lmax-lmin): ratio between width change of a phase of evolution and difference between maximum and minimum width of the entire period. tratto fase 1 fase 2 fase 3 t1 δl δl/(lmaxt2 δl δl/(lmaxt3 δl (m) δl/(lmax(m) lmin) (%) (m) lmin) (%) lmin) (%) mb 1877-1954 -105.9 -47 1954-1995 -120.3 -53 1995-2006 37.1 16 md2 1877-1954 -246.9 -47 1954-1995 -279.5 -53 1995-2006 15.5 3 me1 1877-1954 -268.5 -42 1954-2003 -375.3 -58 2003-2006 10.6 2 vc2-vd 1877-1971 -118.2 -62 1971-1995 -70.9 -38 1995-2004 13.3 7 ve 1877-1954 -301.0 -68 1954-1995 -140.2 -32 1995-2004 9.4 2 pa 1890-1969 -84.1 -47 1969-1997 -94.9 -53 1997-2000 0.8 0.4 pb 1890-1969 -118.3 -41 1969-2007 -167.7 -59 pc 1890-1969 -137.4 -69 1969-1997 -60.5 -31 1997-2000 5.9 3 cb 1883-1986 -68.9 -50 1986-2004 -69.4 -50 cc 1883-1994 -76.6 -81 1994-2004 -18.2 -19 cd1 1883-1994 -116.6 -89 1994-2004 -13.6 -10 tabella 6 riepilogo delle variazioni di quota del fondo (da dati topografici disponibili e rilievi di campo). summary of bed-level changes (from available topographic data and field surveys). dinamica recente ed attuale di alvei ... zioni di equilibrio e/o sedimentazione, quest'ultima spesso localizzata in alcuni punti o sottotratti piuttosto che generalizzata. per quanto riguarda il f. panaro non sono state osservate evidenze generalizzate di sedimentazione o di incisione, pertanto la situazione dominante è stata classificata come di equilibrio. tale situazione di equilibrio del fondo è tuttavia fortemente condizionata dalla presenza di numerose traverse lungo il tratto di studio, in assenza delle quali è possibile che il fondo sarebbe ancora in fase di incisione. anche nel caso del f. cecina la situazione più frequente è stata quella di equilibrio, seppure spesso sono state osservate evidenze di situazioni di sedimentazione piuttosto localizzata in alcuni punti. le informazioni disponibili sull'evoluzione temporale della quota del fondo sono limitate solo ai tratti inferiori dei fiumi magra e vara, per i quali si dispone di un numero relativamente elevato di profili del fondo. a titolo di esempio si riporta in figura 4 il trend evolutivo della quota del fondo (media del tratto) relativa ai due tratti md2 ed me1 del f. magra: è possibile osservare in entrambi i casi un andamento piuttosto simile di abbassamento del fondo tra 1914 e 1989, con un incremento del tasso di abbassamento successivo al 1958 (più evidente nel sottotratto me1). per quanto riguarda gli anni successivi al 1989, si osserva in entrambi i casi una inversione di tendenza, ancora in atto nel sottotratto md2, mentre nel sottotratto me1 l'ultimo rilievo (2006) registra una nuova flessione della quota del fondo. risulta particolarmente interessante riportare sugli stessi grafici l'andamento temporale della larghezza dell'alveo, in modo da poter verificare l'esistenza di interazioni tra i due tipi di aggiustamento morfologico. per quanto riguarda le modifiche precedenti al 1989, si nota come restringimento ed abbassamento procedono in maniera analoga, eccezione fatta per l'incremento di larghezza nel 1954 già osservato precedentemente. successivamente al 1989, è ancora più interessante osservare come ci sia una buona corrispondenza tra inversioni di tendenza del fondo e di larghezza: ad un aumento di larghezza corrisponde un innalzamento della quota del fondo e viceversa, ed è anche interessante notare che le variazioni di quota sono molto più significative, se rapportate alla variazione totale del periodo, rispetto alle variazioni di larghezza. 5. sintesi e discussione dei risultati i risultati di questa ricerca permettono di avere a disposizione un numero più ampio di casi di studio per i quali sono ben definiti i trend di aggiustamento morfologico, rispetto a quanto già noto sull'evoluzione di alvei fluviali dell'appennino settentrionale (ri n a l d i, 2003; rinaldi et al., 2005a). in figura 5 si riporta schematicamente l'evoluzione dei casi di studio analizzati. tale modello di evoluzione ripercorre quello già proposto da surian & rinaldi (2004), il quale si riferiva a cinque tratti di fiumi dell'italia settentrionale (tra i quali il tratto del f. vara qui indicato come ve) a morfologia inizialmente a canali intrecciati. tuttavia il modello proposto è più articolato, volendo evidenziare alcune differenze osservate tra i vari casi di questo studio. in generale, si distinguono quattro stadi di evoluzione, descritti sinteticamente come segue: (1) stadio i: morfologia iniziale di fine 1800 inizi 1900, a canali intrecciati o wandering; (2) stadio ii: alveo parzialmente inciso e ristretto del periodo 1950 1970 circa, a seguito della prima fase di aggiustamento; (3) stadio iii: alveo con incisione e restringimento massimi di fine anni '90 o ancora in atto, a seguito della fase 2 di variazioni più intense; (4) stadio iv: alveo con inizio di inversione di tendenza e parziale recupero morfologico. l'evoluzione dei fiumi magra e vara coincide esattamente con quanto già rappresentato nel modello di su r i a n & ri n a l d i (2003), mentre i f. panaro e f. cecina denotano alcune differenze. il f. panaro subisce una incisione mediamente più forte rispetto ai casi precedenti (in particolare nel tratto pb), presenta nello stadio iii una morfologia solo in alcuni tratti a barre alternate, mentre in altri casi raggiunge una configurazione a canale singolo quasi priva di barre. lo stadio iv di parziale recupero morfologico è possibile per i tratti pa e pc, mentre il tratto pb è tuttora nello stadio iii. nel caso del f. cecina, la morfologia iniziale è meglio descritta come w a n d e r i n g (seppure in periodi ancora precedenti era probabilmente a canali intrecciati e continua ad esserlo localmente nello stadio i) ed evolve verso una configurazione a barre alternate e, soprattutto nel tratto cc, l'ulteriore riduzione di larghezza e l'aumento di sinuosità stanno determinando una possibile evoluzione verso una morfologia meandriforme (con 298 figura 4 trend temporal i delle quote del fondo e delle larghezze dell'alveo lungo il t rat to inferiore del f.magra. a: t rat to md2; b: tratto me1. temporal trends of bed-level changes a long the lower magra. a: md2 reach; b: me1 reach. m. rinaldi et al. barre di meandro). l'indice di sinuosità risulta infatti significativamente aumentato tra il 1986 ed il 2004, soprattutto nel tratto cc, mentre il tratto cb è quello in cui si è avuto un maggiore restringimento accompagnato ad una trasformazione morfologica da w a n d e r i n g (localmente a canali intrecciati) a canale sinuoso a barre alternate. la figura 5b mette schematicamente in evidenza una caratteristica comune ai vari casi di studio. si possono considerare nell'ordine le seguenti quattro morfologie, in senso decrescente di larghezza: (a) canali intrecciati; (b) wandering; (c) sinuoso a barre alternate; (d) meandriforme a barre di meandro. quello che si è osservato è un passaggio di morfologie seguendo una traiettoria comune (da a verso d), con la morfologia finale che è funzione di quella iniziale e dell'entità delle variaz ioni. ad esempio, i f iumi magra, vara e panaro partono tutti da una morfologia a canali intrecciati ma il panaro subisce un grado di trasformazione maggiore, mentre il f. cecina parte da una morfologia wandering e si avvicina ad una morfologia meandriforme. nel caso in cui esiste una fase di parziale recupero morfologico (ad esempio per f. magra e f. vara), la tendenza è quella di ripercorrere la stessa traiettoria in senso contrario. e' opportuno a questo punto porre la questione di quali siano le cause di tali variazioni, ed in particolare quali siano le variabili (ad es. portate liquide e/o solide) dalle cui modifiche dipendano tali tendenze passate ed attuali. l'associazione causa effetto tra variazioni morfologiche osservate ed impatti antropici è evidente (tab. 3 e fig. 6). come già osservato precedentemente (si veda ad es. rinaldi, 2003; surian & rinaldi, 2003), la fase 1 di abbassamento e restringimento è associabile a condizionamenti prevalentemente a scala di bacino, mentre la fase 2 è associabile soprattutto al periodo di intensa escavazione di sedimenti dagli alvei. più difficile è identificare possibili fattori naturali che possano avere contribuito almeno in parte a tali modifiche. se si considerano ad esempio le variazioni climatiche, l'unico parametro che può essere realmente preso in considerazione è la precipitazione, in quanto le portate liquide sono a loro volta influenzate da fattori antropici. per quanto riguarda il bacino del f. magra, sono state analizzate numerose serie storiche di precipitazioni totali annue relative a diverse stazioni pluviometriche (rinaldi, 2005), e da tale analisi non si denotano tendenze significative, osservandosi solo una riduzione molto modesta delle precipitazioni nel tempo. analoghe osservazioni sono state fatte per il bacino del f. arno (billi & rinaldi, 1997; agnelli et al., 1998). non è ancora possibile invece fare considerazioni sulle possibili variazioni climatiche in atto e sul loro eventuale ruolo nei confronti della fase di recupero morfologico. informazioni ancora più limitate sono quelle relative ad una possibile influenza della tettonica attiva, ma sulla base della letteratura esistente (surian & rinaldi, 2003) esiste un sostanziale accordo nel ritenere che tale fattore possa influire solo in piccola parte, ma certamente 299 figura 5 riepilogo delle variazioni morfologiche. a: modello evolutivo dei tre casi di studio. b: variazioni della morfologia d'alveo. le frecce rivolte verso il basso indicano le variazioni di pattern durante le fasi di incisione e restringimento (fasi 1 e 2); la freccia rivolta verso l'alto indica la fase 3 di parziale recupero morfologico (solo per f. magra f. vara). morfologie d'alveo: (a) a canali intrecciati; (b) wandering; (c) sinuoso a barre alternate; (d) meandriforme a barre di meandro. summary of morphological change. a: model of channel evolution for the three study cases. b: changes in channel morphology. the arrows turned down point out the changes in channel pattern during the phases of incision and narrowing (phases 1 and 2); arrow turned up point out the phase 3 of partial morphological recovery (only for magra r. vara r.). channel morphologies: (a) braided; (b) wandering; (c) sinuous with alternate bars; (d) meandering with point bars. dinamica recente ed attuale di alvei ... non può spiegare variazioni morfologiche così significative come quelle osservate negli ultimi 100 anni circa. i fattori antropici hanno potuto determinare le variazioni morfologiche osservate in vari modi: (a) modificando direttamente l'alveo (ad esempio tramite pennelli, canalizzazioni ed in parte escavazione di sedimenti); (b) modificando le variabili guida (portate liquide e solide) le cui variazioni possono avere indotto aggiustamenti morfologici dell'alveo. per quanto riguarda il secondo caso, si può osservare che, nei casi di studio in esame, la gran parte degli impatti antropici ha avuto un effetto prevalentemente sulle portate solide, piuttosto che su quelle liquide. le dighe possono avere avuto una certa influenza riducendo anche le portate di piena (oltre che le portate solide), ma tale effetto potrebbe essere stato significativo solo per il f. vara (negli altri casi i bacini sottesi da dighe sono poco significativi), mentre tutti gli altri t ipi di interventi non hanno significative influenze sulle portate di picco. per le uniche due stazioni di misura (f. cecina e f. magra) che hanno registrato con continuità le portate massime annuali, è stato verificato che non esistono anomalie particolari nell'andamento delle portate nell'intervallo in cui si sono verificate le maggiori variazioni morfologiche (rinaldi, 2005). analoghe osservazioni erano state fatte per il f. arno (ri n a l d i, 2003), per il quale non è osservabile alcuna evidenza di variazioni significative nell'intensità e frequenza di eventi di piena in grado di spiegare l'accelerazione della fase di incisione nella seconda metà del xx secolo. e' pertanto evidente che la variabile guida principale dalle cui variazioni sono dipesi gli aggiustamenti morfologici è rappresentata dalle portate solide. le variazioni di portate solide possono essere principalmente avvenute: (1) a scala di bacino, attraverso variazioni di uso del suolo (rimboschimenti) e realizzazione di briglie; (2) riduzione della quantità di sedimenti disponibili in alveo per il trasporto solido al fondo, a causa dell'asportazione diretta di sedimenti dagli alvei. la relazione tra variazioni di portate solide e di larghezza dell'alveo è consistente con quanto riportato in letteratura: in particolare, il modello di aggiustamenti morfologici proposto da sc h u m m (1977) prevede, seppure solo in termini qualitativi, una riduzione della larghezza in conseguenza di una riduzione delle portate solide e viceversa. la riduzione di portate solide può non essere l'unico fattore che ha determinato le fasi di restringimento: un certo ruolo può essere stato giocato anche dalla realizzazione di pennelli ed altre difese di sponda. questo è particolarmente evidente per il basso magra e basso vara, dove negli anni '30 sono stati realizzati numerosi pennelli. d'altra parte tali interventi non possono essere considerati l’unica causa di restringimento, in quanto la riduzione di larghezza si è registrata anche in numerosi altri casi dove non si sono realizzati pennelli. un approfondimento particolare della discussione va dedicato infine alla eventuale esistenza di una fase di recupero morfologico iniziata negli ultimi anni. e' necessario innanzitutto notare che tale fase, alla luce dei casi di studio qui esaminati, appare meno chiara e meno diffusa di quanto non sembrasse in precedenti studi (su r i a n & ri n a l d i, 2004; ri n a l d i et al., 2005a). i quesiti fondamentali che si pongono sono: (1) quali sono le cause dell'inversione di tendenza, laddove si è verificata; (2) perché non si è verificata in tutti i casi. nell'ambito dei casi di studio analizzati, una inversione di tendenza della larghezza si è verificata con chiarezza nei f. magra e f. vara, seppure ad una fase di riallargamento piuttosto marcato iniziata generalmente intorno al 1995 è quasi sempre seguita una nuova riduzione di 300 figura 6 schema riepilogativo delle variazioni morfologiche complessive (rispetto alla situazione iniziale di fine 1800) in funzione della morfologia iniziale e del grado relativo di impatto antropico. classi di incisione: im) moderata (tra 1 e 2 m); ii) intensa (tra 2 e 4 m); iii) molto intensa (>4 m). classi di restringimento: rm) moderato (tra 20 e 50%); ri) intenso (tra 50 e 70%); rii) molto intenso (>70 %). summary sketch of the overall morphological changes (compared to the initial situation at the end of 1800) as a function of the initial morphology and the relative degree of human impact. classes of incision: im) moderate (between 1 and 2 m); ii) intense (between 2 and 4 m); iii) very intense (>4 m). classes of narrowing: rm) moderate (between 20 and 50%); ri) intense (between 50 and 70%); rii) very intense (>70 %). m. rinaldi et al. larghezza negli ultimi anni. la figura 4 mostra chiaramente come tali oscillazioni di larghezza siano strettamente legate anche a variazioni della quota del fondo. un contributo a tali tendenze recenti può essere certamente legato a due eventi di piena di forte intensità verificatisi nel 1999 e nel 2000, i quali hanno certamente causato la riattivazione di numerosi processi erosivi e di produzione di sedimenti a scala di bacino. va tuttavia notato che l'inversione di tendenza non può essere attribuita esclusivamente a tali piene, in quanto essa era già iniziata tra il 1995 ed il 1999. e' presumibile quindi che tali primi segnali di allargamento siano legati ad un inizio di riattivazione di processi erosivi, avvenuto anche durante piene di non eccezionale intensità verificatesi in quegli anni, che ha fatto seguito, con un certo ritardo, al termine della fase di intensa attività di escavazione di sedimenti. a ciò si aggiunge il fatto che, durante questi ultimi anni, le rimozioni di sedimenti e le protezioni di sponda sono state molto ridotte e limitate a situazioni localizzate. piuttosto inaspettata appare la riduzione di larghezza manifestatasi in gran parte dei casi (seppure talora molto limitata) durante gli ultimi anni. da una attenta analisi da foto aeree delle situazioni in cui tale riduzione si è manifestata, essa appare sostanzialmente legata ad una parziale ricolonizzazione da parte di vegetazione di superfici relativamente meno attive che si erano probabilmente rimodellate durante gli eventi del 1999-2000, a causa dell'assenza di eventi di piena successivi altrettanto intensi. pertanto, si può concludere che per i fiumi magra e vara non si può parlare di una fase attuale univoca di riallargamento, ma piuttosto di una fase di oscillazioni morfologiche nella direzione di un parziale recupero (inversione di tendenza rispetto alla fase precedente), guidate dal verificarsi di eventi di piena di una certa intensità e dall'intervallo di tempo intercorrente tra eventi successivi. per quanto riguarda il f. panaro, per due tratti si è verificata una lieve inversione di tendenza (tra 1997 e 2000) mentre nel caso del tratto pb, per il quale si disponeva anche del volo più recente del 2007, la tendenza risulta essere tuttora in restringimento. l'assenza di una chiara fase di recupero morfologico può essere legata ai seguenti fattori: (1) sostanziale deficit di sedimenti in alveo (si ricorda che in alcuni tratti il corso d'acqua ha eroso tutto il materasso alluvionale andando ad incidere il substrato); (2) discontinuità longitudinali (numerose briglie) che ostacolano il flusso di sedimenti; (3) attività di escavazione, che è continuata (seppure a tassi nettamente inferiori rispetto ai decenni precedenti) e che è ancora in atto. si può pertanto dire che nel caso del f. panaro il mancato recupero morfologico è sostanzialmente legato alla perdurante mancanza o scarsità di sedimenti tali da favorire una inversione di tendenza. il f. cecina per alcuni aspetti si differenzia dai precedenti, in quanto sembra che le risposte morfologiche stiano avvenendo con un certo ritardo rispetto agli altri due casi di studio, presumibilmente perché la fase di escavazione di sedimenti più intensa è stata leggermente successiva. un altro fattore importante può essere legato alle condizioni di energia e di trasporto solido di questo corso d'acqua, che è caratterizzato da minori portate liquide e soprattutto minori portate solide, come testimoniato dalla larghezza iniziale più ridotta e dalla stessa morfologia iniziale. l'energia del corso d'acqua ed il trasporto solido al fondo relativamente bassi rispetto ad altri casi può ritardare la riattivazione di processi erosivi ed il recupero morfologico. l'attuale tendenza sembra verso un ulteriore restringimento ed accentuazione dei processi di sviluppo di meandri, attraverso i quali l'alveo tende ad aumentare la propria sinuosità in risposta di un deficit ancora esistente di portate solide rispetto alla capacità di trasporto. le erosioni di sponda, associate al processo di sviluppo di meandri, stanno tuttavia favorendo un rifornimento di nuovi sedimenti che potrebbero quindi nei prossimi anni invertire la tendenza del fondo e favorire un arresto del processo di restringimento. 6. conclusioni le principali conclusioni che si possono trarre da questo studio sono elencate di seguito. 1. i casi di studio analizzati tendono a confermare alcune delle osservazioni fatte in studi precedenti (surian & ri n a l d i, 2004; ri n a l d i et al., 2005a), consentendo tuttavia di avere una casistica più ampia tale da contribuire ad un maggiore chiarimento di alcuni aspetti. 2. per quanto riguarda l'evoluzione tra fine 1800 e anni '90, si conferma l'esistenza di due fasi successive di evoluzione, dove l'incisione del fondo ed il restringimento dell'alveo attivo sono avvenuti pressoché in contemporanea e con intensità diverse nelle due fasi. 3. la portata solida al fondo appare essere la variabile guida più importante nel determinare queste tendenze evolutive. 4. la fase attuale di allargamento appare invece meno chiara rispetto a quanto ipotizzato precedentemente, ed è piuttosto definibile come una fase di parziale recupero morfologico, caratterizzata da oscillazioni di larghezza piuttosto che da una tendenza univoca all'allargamento. 5. in alcuni casi tale fase di recupero morfologico è assente o tuttora incerta: ciò può essere legato a varie ragioni, quali (a) un intervallo di tempo più breve rispetto alla fase di massima escavazione; (b) una pressione antropica più forte (f. panaro) che in alcuni casi determina una asportazione di sedimenti ancora significativa; (c) caratteristiche naturali dell'alveo (minore energia e minore trasporto solido al fondo) che determinano una più lenta reazione del corso d'acqua. ringraziamenti ricerca finanziata dal miur nell'ambito del progetto prin 2005 “dinamica recente ed attuale di alvei fluviali in italia centro-settentrionale: tendenze evolutive, cause ed implicazioni applicative” (responsabile nazionale: nicola surian, responsabile u.o. firenze: massimo rinaldi) e del programma miur 2003-07 “incentivazione alla mobilità di studiosi stranieri e italiani residenti all'estero” (liliana b. teruggi). si ringraziano g. doretti e l. bellacci per gli importanti contributi relativamente alle misure effettuate su f. magra, f. vara e f. panaro. si ringrazia f. vannacci del laboratorio di sedimentologia del dipartimento di ingegneria civile e 301dinamica recente ed attuale di alvei ... ambientale di firenze per le analisi granulometriche dei sedimenti del fondo. si ringraziano infine m. marchetti e p.c. aucelli per aver contribuito a migliorare l'articolo attraverso i loro commenti costruttivi. bibliografia ag n e l l i a., bi l l i p., ca n u t i p. & ri n a l d i m. (1998) dinamica evolutiva recente dell'alveo del fiume arno monografia cnr-gndci, pubblicazione n° 1739, pacini editore, pisa, 191 pp. billi p. & rinaldi m. (1997) human impact on sediment yield and channel dynamics in the arno river (central italy) in: walling d.e. & probst j.l. (eds), human impact on erosion and sedimentation, iahs publ.no. 245, 301-311. br a g a g. & ge r v a s o n i s. (1989) evolution of the po river: an example of the application of historic m a p s in: petts, g.e., moller, h., roux, a.l. (eds.), historical change of large alluvial rivers: western europe, wiley, pp. 113-126. bunte k. & abt s.r. (2001) sampling surface and subsurface particle-size distributions in wadable graveland cobble-bed streams for analyses in sediment transport, hydraulics, and streambed monit o r i n g. u.s.department of agriculture, forest service, rocky mountain research station, general technical report rmrs-gtr-74, 428 pp. castiglioni g.b. & pellegrini g.b. (1981) two maps on the dynamics of a river bed. erosion and sediment transport measurement proceedings of the iahs symposium, florence, 22-26 june 1981, pp. 223228. castaldini d. & piacente s. (1995) channel changes on the po river, mantova province, northern italy in: hickin, e.j. (ed.), river geomorphology, wiley, pp. 193-207. cavazza s. & pregliasco p. (1981) sulle modificazioni dell'apporto terrigeno alla foce del fiume magra causate dall'uomo. in: antonelli, a., cavazza, s., cortemiglia, g.c., egori , f. , martinel li, m., pellegrini, n., pregliasco, p., raggi, g., tra fiumi, mare e terraferma, tipografia zappa, sarzana, 57128. ma r c h e t t i m. (2002) environmental changes in the central po plain (northern italy) due to fluvial modifications and anthropogenic activit ies geomorphology, 44, 361-373. rinaldi m. (2003) recent channel adjustments in alluvial rivers of tuscany, central italy earth surface processes and landforms, 28 (6), 587-608. rinaldi m. (2005) studio geomorfologico dei principali alvei fluviali nel bacino del fiume magra finalizzato alla definizione di linee guida di gestione dei sedimenti e della fascia di mobi li tà funzionale . relazione finale convenzione di ricerca tra autorità di bacino del fiume magra e dipartimento di ingegneria civile, università di firenze, 160 pp. ri n a l d i m. (2007) approfondimenti dello studio geomorfologico dei principali alvei fluviali nel bacino del fiume magra finalizzato alla definizione di linee guida di gestione dei sedimenti e della fascia di mobilità funzionale. relazione finale convenzione di ricerca tra autorità di bacino del fiume magra e dipartimento di ingegneria civile e ambientale, università di firenze, 154 pp. rinaldi m. (2008) schede di rilevamento geomorfologico di alvei fluviali. il quaternario, questo volume. rinaldi m. & simon a. (1998) bed-level adjustments in the arno river, central italy geomorphology, 22 (1), 57-71. rinaldi m., simoncini c. & sogni d. (2005a) variazioni morfologiche recenti di due alvei ghiaiosi appenninici: il f.trebbia ed il f.vara geografia fisica e dinamica quaternaria, suppl.vii, 313-319. ri n a l d i m., wy z g a b. & su r i a n n. (2005b) effects of sediment mining on channel morphology and environment in alluvial rivers river research and application, 21, 805-828. schumm s.a. (1977) the fluvial system wiley, new york 338 pp. surian n. & rinaldi m. (2003) morphological response to river engineering and management in alluvial channels in italy geomorphology, 5 0 (4), 307326. surian n. & rinaldi m. (2004) channel adjustments in response to human alteration of sediment fluxes: examples from italian rivers in: sediment transfer through the fluvial system, proceedings symposium held in moscow, august 2004, iahs publ.288, 276-282. surian n. (1999) channel changes due to river regulation: the case of the piave river, italy earth surf. process. landforms, 24, 1135-1151. wo l m a n m.g. (1954) a method of sampling coarse river-bed material. am.geophys.union.trans., 35, 951-956. 302 ms. ricevuto il 7 dicembre 2007 testo definitivo ricevuto il 17 marzo 2008 ms. received: december 7, 2007 final text received: march 17, 2008 m. rinaldi et al. imp.cucchi& geology and geomorphology of the “rosandra” valley for a cultural enhancement franco cucchi, alessio mereu, sara oberti, chiara piano, anna rossi & luca zini department of geological, environmental and marine sciences, university of trieste; cucchi@units.it abstract: f. cucchi et al., geology and geomorphology of the “rosandra” valley for a cultural enhancement. (it issn 0394-3356, 2005). the rosandra valley is located near trieste (italy), on the border of classical karst, and is a canyon-like depression excavated in tertiary limestone. the origin of the valley is mainly due to presence of faults and overthrusts and different attitude to erosion between limestone and marls, which makes it a beautiful example of lithological and structural control on morphogenesis. furthermore, its slopes are interested by extended and mature underground karst phenomena that contribute to making the whole hydro-structure more interesting. the valley is also remarkable for its local vegetation, due to its particular climatic conditions, and to its prehistoric and historical value, stemming from its geographic location. riassunto: f. cucchi et al., geologia e geomorfologia della val rosandra per una sua valorizzazione culturale. (it issn 0394-3356, 2005). la val rosandra è ubicata in provincia di trieste, al confine del carso classico, ed è una valle profondamente incisa in calcari terziari. la sua origine è principalmente legata alla presenza di faglie e di sovrascorrimenti ed all’erosione selettiva dovuta alla presenza di litotipi diversi come calcari e marne; tutto ciò ha creato un esempio spettacolare di forme influenzate dalla litologia e dalla tettonica. inoltre i suoi rilievi sono interessati da estesi e maturi fenomeni carsici ipogei così da creare una singolare idrostruttura. la valle è anche attraente per la vegetazione locale, condizionata dalle particolari condizioni climatiche, e per l'interesse preistorico e storico dovuto alla posizione geografica. key words: rosandra valley, karst, geomorphology, geology, geopark. parole chiave: val rosandra, carso, geomorfologia, geologia, geopark. il quaternario italian journal of quaternary sciences 18(1), 2005 volume speciale, 185-196 1. introduction "the valley" – as the triestines call it – opens onto the western side of the trieste classical karst plateau: it is constituted by the intermediate and the final stretch of a creek – the rosandra creek – that originates from the confluence of two water streams – the t. botazzo and the rio griza – whose springs are located in slovenia, a few miles away from the italian border. the initial stretch, now in the slovenian territory, consists of a normal wide verdant valley that, at one point, deeply engraves white bare limestone rocks. after some miles, it results in a plain overlooking the gulf of trieste. the whole area, and in particular m.te stena on the right, is characterised by surface and underground karst. 100 cavities have been surveyed, some of which cover many hundred metres. among them one of the most beautiful cave can be found (the gualtiero savi cave, point 1, fig. 2): it has rich speleothemes (no important concretions dating back to later than 300,000 years ago have been found), an interesting morphology of corrosive and sedimentary origin, and extends over approximately 4,000 metres, thus testifying to the complex geomorphologic and hydrogeological evolution of the “classical karst”. fig. 1 location map. ubicazione. 186 f. cucchi et al. on the left side, the valley was delimited by the so-called “via del sale” (“salt road”), used in roman times and in the middle ages to transport salt to the inland villages. the tracks of the first railway line connecting the hapsburg port of maria theresa to vienna and ljubljana (1887), have now been converted into a cycle track, which means that the old path is still used nowadays (point 3, fig. 2). caves with prehistoric remains, ruins of castles and hill forts, mills, country churches, ruins of the roman aqueduct and abandoned querries prove the intense and ancient settlements in the area (fig. 2). the valley’s peculiar climatic and geomorphologic conditions (closeness to the sea, swift passage from the sea level to an altitude of over 400 metres) and its geographical location (the farthest northern limit of the adriatic sea still belonging to the european continent) provide the valley with utterly peculiar fauna and vegetation. the valley, which has been long regarded as “special” for its outstanding naturalistic value, also presents an important and unique geological and geomorphologic heritage and is worth becoming an interesting geopark. 2. geological considerations as far as the lithostratigraphic succession is concerned, the following items can be found (going from the most ancient to the most recent one): the limestone rocks of the “opicina member” (thanetian-llerdian), belonging to the informal “limestone formation of trieste karst” (cucchi et al., 1989a), the “fucoidi” marls (lower eocene), the flysch (lower and medium eocene) and quaternary deposits. as can be observed from the viewpoint of s. lorenzo (point 4, fig. 2), the most abundant and characterising lithotype is the “opicina member” limestone. it includes compact limestones, usually of light grey but also of black colour, fetid when struck, presenting highly fossiliferous migrated oils (foraminifers, among which alveolinids and nummulites, gastropods ed echinoids) sometimes spathized with fracturing from scalelike to pseudo-conchoidal. limestone stratification is usually sharp and on a decimetre scale but metre-thick limestone banks with indistinct stratif ication are not infrequent. consequently, karstifiability ranges from high to very high and erodibility from low to very low. according to recent studies (drobne, 2003, in press), the above-mentioned limestones were deposited in an “intermediate photic zone” environment (hottinger, 1997), i.e. with bathymetries ranging between 40 and 80 metres. these limestones mainly testify to coastal marine settings. marly limestones characterize the upper-most part of the member, showing an increasing occurrence of planktonic foraminifers. these limestones indicate an increasing depth and the decline of previous taxa, prior to the drowning of the carbonate platform in relation to terrigenous turbidites (flysch). at the top, the increase in terrigenous materials progressively modifies the lithology, to reach facies of grey and hazel marl-limestone with decimetre-scale thickness (cucchi et al., 1989b), thus testifying both to the carbonate platform drowning and to a sharp change in regional paleogeographical conditions. from a stratigraphic point of view, eocene “fucoidi” marls follow: they are basically lamellar argillites whose colour varies from grey to bluish (fig. 3). they reach their maximum 10-metre thickness on m.te stena hillsides along the cycle-track built on the ancient train tracks (point 5, fig. 2). if thickness is definitely modest, remarkable instead are geomorphologic conditionings: due to its plasticity, the horizon is often characterised by lowangle reverse faults, in acts as non-kastifiable level, is impermeable and shows rather high erodibility. at a higher-contact level, the flysch that outcrops is constituted by alternation of marl levels and sandstones with variable thickness. marl thickness ranges from millimetreto centimetre-scale; sandstone thickness from centimetreto decimetre-, sometimes metrescale. sandstones, which are usually predominant, are moderately sorted, with average grain size being approximately 0.1 mm. as they are carbonate-cement quartzo-feldspathic sandstones, they can be defined graywackes. on average, they are composed by minimum 50% silicon oxide (containing 43÷53% quartz and 6÷11% flint) and by feldspars (18÷26%), mainly plagioclase and mica feldspars (4÷6%) with chlorite and muscovite predominating over biotite, carbonates (16÷20%, both cement and often highly altered clasts), and a series of other minerals present in minimum quantities (iron oxides, glauconite, tourmaline, garnets, zircon, rutile: cumulative percentage between 1 and 3%). these mineral constituents are practically sterile, even though some jellyfish rests have been found, alongside rare globigerinae. marls, whose mineral composition is fairly similar to that of graywackes, but for a higher percentage of carbonates than of other mineral constituents, are not very rich in organic residues. the most abundant organic elements are plankton foraminiferans such as globigerinae and globorotaliae. the fossiliferous fraction of basal marls dates back to the middle-high cuisian age (onofri, 1982). this alternation confirms the progressive platform drowning and the appearance in the basin of elements deriving from the alpine orogenesis in european and balkan regions. sedimentary structures such as flutes and burrow casts are frequent. due to its plasticity, flysch presents low-range folds giving it a good level of erodibility, plasticity and substantial impermeability. quaternary deposits are constituted by sometimes-cemented scree slope, by alluvial deposits and by eluvial-colluvial coverings. in the case of slope debris, clasts are elements mainly of limestone nature, belonging to the opicina member: they are sharp-edged and vary in size. only rarely do sandstone clasts, whose shape is more rounded, appear; in the breccias, the cement is calcitic and of reddish-grey colour. its cementation level highly varies from point to point and it sometimes affects the surface layers only: consequently, also permeability and erodibility can vary. some landslide displaced materials are present: they are generated by collapse and rolling of large breccia blocks slid due to undermining to the foot of 187geology and geomorphology ... fi g. 2 l oc at io n on t hr ee -d im en si on al m od el o f v al r os an d ra p ec ul ia rit ie s: 1 – g ua lti er o s av i c av e; 2 o rs i c av e; 3 o ld a us tr ia n ra ilw ay l in e, n ow c on ve rt ed i nt o a cy cl in g tr ac k; 4 v ie w p oi nt n ea r s . lo re nz o; 5 “ fu co id i” m ar l o ut cr op ; 6 p re m ud a m ou nt ai n s he lte r; 7 t ec to ni c lim it; 8 a nt ro d i b ag no li sp rin g; 9 w at er fa ll; 1 0 s . m ar ia in s ia rii s c hu rc h; 1 1 š tu rk sp rin g; 1 2 a nt ro d el le n in fe ; 1 3 o p p ia s p rin g; 1 4 v ie w p oi nt n ea r m oc cò ; 1 5 m ar tin a c uc ch i c av e; 1 6 g al le rie c av e; 1 7 fe ss ur a d el v en to c av e; 1 8 m .t e c ar so h ill fo rt ; 1 9 m .t e s . m ic he le h ill fo rt ; 2 0 r om an a q ue d uc t; 2 1 s al t ro ad ; 2 2 d ra ga c as tle . u b ic az io ne s u m od el lo t rid im en si on al e d el le p ec ul ia rit à d el la v al r os an d ra : 1 g ro tt a g ua lti er o s av i; 2 c av er na d eg li o rs i; 3 tr ac ci at o ve cc hi a fe rr ov ia a us tr ia ca , or a p is ta c ic la b ile ; 4 v ed et ta d i s . lo re nz o; 5 m ar ne a f uc oi d i; 6 r ifu gi o p re m ud a; 7 c on ta tt o te tt on ic o; 8 a nt ro d i b ag no li; 9 c as ca ta ; 10 c hi es a d i s . m ar ia in s ia rii s; 1 1 fo nt e š tu rk ; 12 a nt ro d el le n in fe ; 13 f on te o p p ia ; 14 v ed et ta d i m oc cò ; 15 g ro tt a m ar tin a c uc ch i; 16 g ro tt a d el le g al le rie ; 17 f es su ra d el v en to ; 18 c as te lli er e d el m .t e c ar so ; 19 c as te lli er e d el m .t e s . m ic he le ; 2 0 a cq ue d ot to r om an o; 2 1 v ia d el s al e; 2 2 c as te llo d i d ra ga s . e lia . 188 the side cemented on the surface, and by planar sliding on stratum levels of sometimes-thick and wide limestone banks. the alluvial deposits present along the rosandra torrent are polygenic alluviums, with scarce fine-grained fraction, locally interbedded with sandy or sandysilt lenses. pebble size – pebbles are often rounded in shape and of mainly arenaceous and secondly calcareous nature (calcitic speleothems also) – varies from centimetreto decimetre scale. a coarse diversely interbedded polygenic-alluvium escarpment, located opposite the “rifugio premuda”, bears witness to phases of intense transport (point 6, fig. 2). the eluvial-colluvial coverings are generally silty and clayey, mostly deriving from degradation of sandymarly formations and, limitedly, of carbonate formations. this red clayey soils, rich in iron oxides and known under the name of “red soils”, constitute a thin and discontinuous veil on the karst surface. from a structural point of view, the rosandra valley is part of the “imbricate structure of čičarija”, characterised by thrust wedges in a sequence of reverse faults and overthrusts that follow the dinaric trend (placer, 1981). an excellent panoramic view onto the tectonic structure of the area can be enjoyed from the viewpoint of s. lorenzo (point 4, fig. 2), located at 377 metres above sea level in proximity of the village of the same name. if we assume a geological section oriented n-s, from here the monocline imbricate structure can be observed (m.te stena on the orographic right of the creek): it first follows an apparently synclinal trend, along the axis where the valley has formed, and a clearly anticlinal trend afterwards, thus conditioning m.te carso hillsides (on the orographic left of the creek). the compression stresses coming from the north-eastern sector gave rise to three main overthrusts among the rigid limestone masses and the plastic flysch deposits (fig. 4): the reverse-fault set located on the orographic right of the rosandra creek, on the hillsides of m.te stena; the overthrust known as the “crinale fault” (ridge fault); the “m.te carso overthrust”, lowangle fault stretching towards s-e and originating the tectonically imbricate structure of the cicarija region (slovenia and croatia). the first is a case of a small overthrust family generally connecting palaeocene-eocene limestones on “fucoidi” marls of eocene age. degradation and fracturing (ranging from millimetre to centimetre scale) of the latter lithotype makes this tectonic contact along the route from the viewpoint of s. lorenzo to the village of s. antonio in bosco (point 7, fig. 2) particularly evident. here it is also possible to find flysch sandstones enclosed in the underlying marls. the “crinale fault” and the “m.te carso overthruf. cucchi et al. fig. 3 “fucoidi” marl outcrop. affioramento di marna a fucoidi. fig. 4 lithological and structural scheme: 1reverse thrusts; 2crinale fault; 3m.te carso overthrust; 4m.te carso fault. lithology: light grey = limestone; dark grey = fucoidi marl and flysch. schema litologico strutturale: 1faglie inverse; 2faglia del crinale; 3sovrascorrimento del m.te carso; 4faglia del m.te carso. litologie: grigio chiaro = calcari; grigio scuro = marne a fucoidi e flysch. 189 st”, both advancing towards wsw, identify three welloutlined structural areas. the first block, the main one, is constituted by the lithoid mass underthrusted in the “m.te carso overthrust”. this block presents numerous deformation structures due to hanging walls, many of which are brilliant study cases, such as the hook-pattern of marls and sandstones in vertical contact with the limestones, as the case that is clearly visible in the antro di bagnoli spring (point 8, fig. 2). the second block is constituted by a thrust wedge located between the “m.te carso overthrust” and the “crinale fault”. its main features can be found in two distinct sub-areas: the northern one, mostly characterised by generally reverse faults and corresponding with m.te carso culmination, where the hinge of “m.te carso anticline” has been preserved (martinis, 1971), stopping at another fault located sw – called “m.te carso fault” – oriented sw and with dip direction e, thus identifying the southern sub-area (fig. 4). the third block is delimited by the “crinale fault”, structure with axis nw-se, whose top shows a high level of limestone-rock tectonisation. to summarize, the area is characterised by rigid limestone masses that are either overthrusted, or raised on reverse faults on flysch and on plastic marl rocks, with ne dip-direction fault surface, an aspect that is clearly visible from the numerous panoramic viewpoints the valley is rich in. 3. geomorphological considerations the rosandra valley is a rare example of karst river valley with surface hydrology. the rosandra creek originates from the confluence (occurring in the slovenian territory) of two water streams – the t. botazzo and the rio griza – whose springs are located in slovenia, a few miles away from the italian border. its basin extends over approximately 21 km2, of which 8 upstream of the confluence, 6 from the point of confluence to the plain. its main course extends over 13 km from the sources to the sea, 5.5 before the confluence and 4 between the point of confluence and the access to the plain. along their course, they first erode the flysch silicon-clastic sediments; only afterwards, in proximity of the village of draga s. elia, do they erode the limestones of the opicina member and, finally, the flysch marlsandstone alternations (potleca, 1997). the first stretch erodes a relatively erodible formation, substantially impermeable. its structure presents a wide undulating syncline with upstream dip direction, in whose core the confluence between t. bottazzo and rio griza occurs. downstream of the village of botazzo, near the state border, the passage from turbidites to marls and to the underlying limestones is made apparent by an over 30-metre-high picturesque waterfall (point 9, fig. 2) that constitutes the mouth of the valley. the hillsides become steeper (with wide berms on the right and structural hillside on the left), the creek flows on the rocks, the first seepage phenomena occur and we can see the formation of a deep canyon-like depression of karst origins into the rock, rich in rapids, pot-holes, small waterfalls, enclosed meanders and basins (fig. 5). geology and geomorphology ... fig. 5 enclosed meandering. meandri incassati. 190 on the left, the creek is occasionally fed by a tributary flowing along a reverse fault that borders the north side of the m.te carso anticline. the riverbed is subject to constant diversions along the main discontinuity-set families up to bagnoli della rosandra, where the slopes decrease and the torrent flows on its ancient alluvial deposits until it reaches its mouth into the sea beyond the zaule plain. noteworthy is again the ancient and massive landslide displaced material due to planar sliding over which the small country church of s. maria in siariis rests (point 10, fig. 2; fig. 6). on the right, scattered in the woods, massive breccia blocks can be seen: they testify to the undermining process at the basis of the scree slope, cemented in proximity of the river’s sharp bend towards sw before reaching the village of bagnoli, and conditioned by the local tectonics – if not neo-tectonics – and by a paleolandslide. a system of springs contribute to feeding the torrent: the zroček spring, on the slovenian territory, the šturk spring (point 11, fig. 2), nearby botazzo village, the zaniér spring (point 12, fig. 2), flowing from the antro delle ninfe, the oppia spring (point 13, fig. 2) located by the overthrust of the “crinale” (ridge) and the antro di bagnoli spring (point 8, fig. 2) in proximity of the village of bagnoli della rosandra. the viewpoints of moccò (point 14, fig. 2) and s. lorenzo (point 4, fig. 2) offer a privileged view on the slopes overlooking the rosandra creek. these slopes are all characterised by rocky cliffs, overhanging rocks, aiguilles and mighty scree slopes, expressing a faceted lithology and complex tectonics. the “grize”, karst gravel areas, are the hallmark of the top of the mountains, alongside the rare rocky outcrop and a poor and scarcely developed soil. the small landforms caused by superficial corrosion are widely extended over the whole limestone area, characterised by medium to medium-high “karstifiability”, and particularly on monte carso hillsides, where the outcrop of limestone banks is more continuous and extended, and originates massive solution runnels (rinnenkarren). underground phenomena are equally developed: 100 caves have been discovered so far, and some of them belong to the some of the most widely extended trieste karst systems. m.te stena, in particular, hosts a comprehensive net of articulated and diversely shaped cavities, basically organised on four levels, which stretches totally over 7,000 metres, thus bearing testimony to ancient geological and hydro-geological origins. the best-known cave is the gualtiero savi cave (point 1, fig. 2; fig. 8), which covers an area of almost 4,000 metres and is the widest underground system in the rosandra valley, thus being the second cave for extension in the whole italian sector of the classical karst. it is a series of sub-horizontal galleries, structural gullies and large chambers located at 350 metres above sea level, and of a set of meanders, smaller caves and smaller galleries to be found at a lower level, approximately 50 metres above sea level (cucchi et al., 1998). surveys conducted via air-tracing methodology have ascertained that the gualtiero savi cave is connected to other cavities such as the martina cucchi cave (point 15, fig. 2), the gallerie cave (point 16, fig. 2), the fessura del vento cave (point 17, fig. 2), and numerous minor ones, whose entrances open at different levels on the hillsides of m.te stena. this is one of the most complex and interesting karst drainage systems of the “classical karst”, thus being a privileged observation point on the spelological development not only of the rosandra valley, but also of the entire karst region. caves present highly remarkable chemical and physical fillings. among them, the polygenetic conglomerates that often obliterate galleries can be mentioned; they also bear witness to intense transportation phases along water streams originating from flyschfacies basins present to the east (clasts, mainly of marly and arenaceous origin, frequently present fragments of speleothems). also speleothems are very interesting: some of them are now practically fossilized and date back to over 300,000 years ago but numerous active specimens – through which it is possible to trace recent climate changes – still exist. it should also be noted that on the left side of the rosandra creek we can find the orsi cave (point 2, fig. 2), a fossil gallery whose filling deposits are still covered by concretioned prehistoric animal remains (ursus spelaeus, rosenmuller & hinroth) dating back to at least 120,000 years ago. f. cucchi et al. fig. 6 the paleo-landslide with the church of s. maria in siariis on the orographic right of the rosandra creek. la paleofrana con la chiesa di s. maria in siariis in sinistra orografica del torrente rosandra. 4. climate considerations karst climatic conditions are peculiar due to its geographic position. karst has, in fact, a transition climate between the atlantic and the continental regime. a similar transition exists between the mediterranean and the alpine climate. as happens in all areas characterised by contact between different climatic regimes, here too local topographic influences acquire the utmost intensity (microclimate), thus contributing to the plant landscape diversification. the rosandra valley is a clear example of this phenomenon, as it features particular microclimate and plant conditions. the upper part of the valley (from klanec, 415 metres above sea level, to bottazzo, 186 metres above sea level) has a prevailing continental climate, both due to its altitude and to the distance from the sea. it is marginally exposed to the “bora” wind, and is mostly covered by trees. two hill slopes with different morphological characteristics form the lower part of the valley (from bottazzo to bagnoli, 72 metres above sea level): they have, in fact, different exposure to the “bora” wind and to solar radiation, which leads to a still higher microclimate diversification. the windward left hill slope (sw) is cha191geology and geomorphology ... fig. 7 evolution study of the rosandra valley (taken from cucchi et al., 1998) highlighting selective corrosion and karstification conditioned by lithology, tectonic structures and general geomorphologic evolution. b: beginning of the speleogenesis, conditioned by fault and stratum planes. c: development and expansion of the g. savi cave and of the gallerie cave, while the underlying fessura del vento cave starts to form. the valley deepens and the “solco del vallone” starts to form on the left of the torrent d: current situation with the high-level cavities visible. the karst now evolves with prevalent diffused sub-vertical percolation due to the wideness of the limestone surfaces exposed to atmospheric agents. schizzo evolutivo della val rosandra (tratto da cucchi et al., 1998) con erosione selettiva e carsificazione condizionate da litologia, lineamenti tettonici ed evoluzione geomorfologica e paleo-ambientale generale. in b, si ha l’inizio della speleogenesi guidata da piani di strato e di faglia. in c, la grotta g. savi e la grotta delle gallerie si sviluppano e si ampliano mentre inizia a formarsi la sottostante fessura del vento. la valle si approfondisce e si imposta il “solco del vallone” sul fianco del m. carso in sinistra del torrente. in d, si ha la situazione attuale con le cavità pensili e con prevalente percolazione ipogea subverticale diffusa data l’ampiezza delle superfici calcaree esposte agli agenti atmosferici. fig. 8 enchanting concretions in the gualtiero savi cave (photograph by umberto tognolli, taken from la grotta dei sogni, rafvg & cai). incantevoli concrezioni nella grotta gualtiero savi (foto di umberto tognolli, tratta da: la grotta dei sogni, rafvg & cai). racterised by a brief period of direct insolation; it has a particularly rigid continental climate, due to its limited altitude, with a consequent delay of the beginning of spring and earlier start of winter. the right hill slope (ne) is made up of series of vertical walls, is always leeward and exposed to the sun and, during most of the day, it is characterised by mediterranean climate conditions. when it is not lashed by the wind, the rock heats up, to the point that the air can reach maximum temperatures of 40°c in summer and of 30°c in winter. the temperature difference between the two hill slopes can reach 10°c. 5. considerations on vegetation the rosandra valley is characterised by different types of vegetation, due to the interaction between diverse environmental factors (geomorphology, lithology, microclimates) and flora: scree vegetation, karst heath, steppe vegetation, karst scrub forest, karst wood, riparian vegetation and pinewood. the vegetation that prevails in the rosandra valley is referred to as the north-adriatic “dripeto” (rich in drypetes plants), from the presence of drypis spinosa ssp. jacquiniana, which forms large pulvini scattered on the scree slope. this cenosis is mainly present on the left hillslope, where the scree slope reaches its maximum accumulation: “from a naturalistic point of view, it is probably the most valuable association of the whole valley, if not of the whole trieste karst” (poldini et al., 1978). “another distinctive feature of the northadriatic “dripeto” is the extremely high percentage of endemic iliric-balkanic species, which makes it rank first among all other karst associations in this respect, with a record of 53.3%” (poldini et al., 1980). furthermore, given the severe microclimate conditions characterising this hill slope of the rosandra valley, scree cenosis shows a particularly high presence of orophytes (plant species that grow in mountain areas) at exceptionally low altitudes, probably the lowest recorded in their diffusion area. the presence of alpine elements is highly significant in the rosandra valley, because it bears witness to the past phyto-historical events that occurred in the valley itself. according to the experts, during the quaternary climate oscillations, a penetration of the alpine flora (in cold periods) and of the mediterranean flora (in hot periods) occurred, whose traces were almost completely cancelled by the local illyrian flora that constitutes the current karst vegetation. many of them managed instead to survive in the rosandra valley thanks to its high microclimate variety, thus enhancing the cultural value of the studies on and the protection of the valley. the karst heath develops on monte carso and monte stena banks, where the slope is gentler and rocks appear next to the scree slope. it is a discontinuous herbaceous formation growing between the outcropping rocks, a typically zoogenous association due to the century-long pasturing activity on deforested areas. its origins probably date back to the brass age (approximately 1800-900 bc), which saw the insurgence of pasture farming on the karst territory. given the constant presence of centaurea rupestris and of carex humilis, this pasturing cenosis has been called “cariceto-centaureto”. besides these species, the heath presents the most typical karst elements, among which numerous endemic species can be found, mainly of illyrian origin (such as genista tergestina, pulsatilla montana, jurinea mollis, etc.). where the iron-debris nappe becomes particularly abundant, the heath also features sesleria juncifolia, a gramineae plant with rigid thin leaves and large clumps, particularly suitable to resist to the ice-cold gusts of winter bora. where rocks combine with particularly dry soils, some elements of stipa eriocaulis can be found, an elegant gramineae plant of mediterranean origin with long plumes fluttering in the wind (from which the vulgar italian name of “lino delle fate” (fairy flax). under conditions of exposure to the south, marked steepness and strong substrate permeability, the heath gives way to a steppe-like grass formation, where the illyrian elements decrease in favour of mediterranean species. this association reaches its maximum flowering period between late summer and autumn, and thrives on the rocky hill slopes over the old stone laundry in moccò and, on the hill slope on the orographic right, on the slope dominating the rail tracks at the entrance of the first gallery. the presence of different species of mediterranean origin is highly valuable, because these plants, as the alpine ones, have witnessed past climatic conditions. the typical karst scrub forest is mainly constituted by low-stemmed ostrya carpinifolia and fraxinus ornus trees and, despite being the most frequent cenosis in the trieste karst, in the rosandra valley it acquires some new peculiarities. first of all, it is of primary origin (poldini et al., 1978), whereas on the rest of the karst territory it developed after the cutting down of the great oak forests (which began during hil lforts times, approximately brass age). this association is precious for the consolidation of unstable slopes, thanks to the development of rooting apparatuses, and is enriched by the presence of elements that are typical of fresh and humid habitats where it declines towards the rosandra canyon-like depression. it is worth noticing the presence of abundant blooming of galanthus nivalis and the frequency of polypodium interjectum, species typical of humid and shadowy rocky habitats. the karst wood is a tree formation characterised by the presence of sessile oaks and turkey oaks (cerri) next to the highly developed oak wood that probably covered the karst soil in prehistoric times, prior to its destruction at the hands of man. this association develops in the coolest and most humid small valleys, where colluvial soils accumulate. the fresh habitat, also enhanced by the tree-crown closure, enables the growth of woodland species typical of central europe (such as erythronium dens-canis, hepatica nobilis, asarum europaeum, etc.). this oak wood is mostly developed in the higher part of the valley, on a marlyarenaceous substratum. the rosandra valley is furthermore enriched by the presence of riparian spinneys, which are a rarity for karst soils, poor in surface hydrography. the most abundant species are salix purpurea, alnus glutinosa e populus nigra, as regards trees, and petasites hybridus e viola alba as far as the undergrowth is concerned. the plateau of s. servolo (monte carso) and monte stena are characterised by austrian black pine 192 f. cucchi et al. (pinus nigra) pinewood. these reforestation processes began in the second half of the xix century, when almost the whole karst area was completely bare due to the deforestation started during the brass age with a view to acquiring new pasturelands. in the rosandra valley, pinewoods are now formed by trees of advanced maturity, which are progressively being substituted by the pressing karst scrub forest that has been developing inside the pinewood in the last decades. worth mentioning is also the presence of species that are either rare or scarcely widespread in the adjoining areas: lilium bulbiferum, lilium carniolicum (two out of the three lily regional species), moehringia tommasinii (endemic species, that is species that grow spontaneously only in the area they are native to), asplenium lepidum (most rare fern of mediterranean distribution), digitalis laevigata, platanthera chlorantha, dactylorhiza maculata, gymnadenia conopsea, the most rare genista januensis and genista holopetala. 6. considerations on fauna as far as the local fauna is concerned, the rosandra valley presents almost all the species that populate the karst area. it is furthermore enriched by some of the species that are usually found in humid ecosystems, particularly rare in the karst environment. as for the mammal fauna, the roe deer is quite widespread, so that it can also be directly sighted during the day. this ungulate mammal frequents the karst scrub forests and clearings. another mammal belonging to the cervidae family that can sometimes be found in the valley is the red deer (cervus elaphus), coming from nearby slovenia. near to water ponds, it is possible to find traces of the presence of the wild boar (sus scrofa). among the rodents, it is worth mentioning the edible dormouse (glis glis), the red squirrel (sciurus vulgaris), which regularly frequents the pinewoods, the water vole (arvicola terrestris) and the yellow-necked mouse (apodemus flavicollis). also two hedgehog species can be found: a western (erinaceus europaeus) and an eastern one (erinaceus concolor), probably competing with each other because they share the same diffusion area in the karst environment. the hare (lepus europaeus), once common, is now threatened by the introduction of the common european rabbit (oryctolagus cuniculus) and by the shrubs spreading in the karst area. as far as the carnivores are concerned, one of the most widespread species is the red fox (vulpes vulpes), particularly precious from an environmental point of view because it also feeds on carrion, thus contributing to preventing the onset of various diseases. the badger (meles meles), the beech marten (martes foina), the polecat (mustela putorius) and the weasel (mustela nivalis) are the mustelids present in the rosandra valley: they are difficult to sight, though, because of their nocturnal habits. during the last years, the sporadic presence of great carnivores has been noted. traces and sighting prove the presence, or at least the passage, of the brown bear (ursus arctos) and of the lynx (lynx lynx), whereas during the last ten years the presence of the golden jackal (canis aureus) has been ascertained. as far as bird species are concerned, the valley hosts a few blue rock-thrush (monticola solitarius) couples. the blue rock thrush is a strongly territorial bird belonging to the turdidae family, a rocky species whose diffusion area is limited to the three european peninsulas the iberic, the italian and the balkan peninsula – and whose males have a metallic-blue plumage colour. the rock partridge (alectoris graeca) is a blue-greyish member of the phasianidae family that perfectly camouflages itself thanks to its colour being quite similar to that of limestone rocks. it is a typical species of the karst heath, once largely widespread and now only rarely present, which can be considered on the verge of extinction due to the spontaneous reforestation of the abandoned pasturelands. the progressive disappearance of the species usually associated with grass formations goes hand in hand with the simultaneous diffusion of the species that nest inside low-stemmed trees, such as the rock bunting (emberiza cia), a quite common species, easy to observe. in the winter months, also the wall creeper (tichodroma muraria) and the crested tit (parus cristatus) find shelter in the rosandra valley. in particular, the presence of this tit and of the coal tit seems to be ascribable to the black-pine pinewood reforestation process, which leads species normally nesting on the alps at an altitude of over 800 m to nest at lower altitudes. as far as the diurnal birds of prey are concerned, the following species can be sighted: the common buzzard (buteo buteo ) , the northern goshawk (accipiter gentilis), which nests in the pinewoods close to clearings, the common kestrel (falco tinnunculus), which nests on the rocky walls above the old railway line, and the sparrowhawk (accipiter nisus), which, though only 20-30-centimetre tall, hunts small birds in the thick karst scrub forest. till some years ago, also the eagle owl (bubo bubo), the largest member of the strigiformes order, used to nest on the valley walls. still present now are the barn owl (tyto alba), the scops owl (otus scops), the little owl (athene noctua) and the tawny owl (strix aluco), which frequent and nest by the entrance of cavities. the rosandra valley is also populated by a rich herpetofauna, constituted both by definitely mediterranean species and by illyrian-balkanic and mediterranean ones. as happens for the vegetation, in fact, karst is respectively the eastern and northern expansion threshold of their diffusion area. the different species of reptiles and amphibians spread in the diverse valley habitats according to their trophic and/or reproductive needs. the most turbulent stretches of the rosandra creek are not suitable for the survival of amphibians eggs and larvae, whereas the calmer coves host the larvae of black and yellow fire salamander (salamandra salamandra), common toad adults (bufo bufo), yellow-bellied toad (bombina variegata), agile frog (rana dalmatina) and edible frog (rana esculenta). along the torrent banks, it is possible to find the grass snake (natrix natrix), species that feeds on amphibians larvae, and the minnow (phoxinus phoxinus). terrestrial amphibians such as the black and yellow fire salamander, the common toad, the edible and the agile frog can populate riparian scrub forests; as far as snakes are concerned, it is possible to find the grass snake, the aesculapian snake (elaphe longissima) and the western whipsnake (coluber viridiflavus carbona193geology and geomorphology ... rius). the most humid areas of karst scrub forests host the green lizard (lacerta viridis), the aesculapian snake, the western whipsnake and, rarely, the bulgarian viper (vipera ammodytes). away from the torrent, more thermophilous reptiles can be found, such as the green lizard, the dalmation algyroides (algyroides nigropunctatus) and the bulgarian viper. karst woods are characterised by the presence of the green lizard, the slow worm (anguis fragilis), the aesculapian snake, the western whipsnake, the smooth snake and the bulgarian viper, though the latter species is not particularly abundant due to the excessive insolation and the scarsity of preys. 7. hystorical considerations anthropogenic use of the rosandra valley is linked with environmental, geomorphologic and geological factors. the valley is a natural link between the sea and the inland, and has thus been always exploited for commercial traffic. the remains and antiquities found in the caves demonstrate that man had been present since prehistoric, mesolithic and neolithic ages. these and other peculiarities contributed to its exploitation both at the hands of prehistoric man and of the tourists-excursionists today. the whole area, and in particular m.te stena on the right, is characterised by both epigeal and underground karst phenomena: approximately twenty cavities are quite interesting from an archaeological point of view. in this respect it is probably worth mentioning the orsi cave (point 2, fig. 2) and the gallerie cave (point 16, fig. 2; fig. 9) (catasto, 2003). the first one is located on monte carso and consists of a single gallery that stretches over a total area of 135 m. the cave name comes from the finding – during exploration – of some ten skulls, jaws, femoral bones and vertebrae belonging to the cave bear species (ursus spelaeus), besides skulls and other bones of smaller-size animals. a particularly surveyed cave is the gallerie cave or finestre cave (point 16, fig. 2), located at the bottom of m.te stena, where archaeological excavation, started during last century by the pioneers of karst prehistoric studies, is still ongoing today at the hands of unauthorised researchers and antiquity collectors with no higher aspirations. the quantity of terracotta articrafts discovered here is higher than that found in any other karst cave, thus demonstrating that the cave had always been frequented by large human settlements throughout all prehistoric ages, thanks to the favourable environmental conditions. some specific ceramics findings suggest that vase-making activities were probably carried out in a chamber of the cave, probably the camino cave. two prehistoric constructions have also been recovered. they are two “hillforts”: one is located under monte carso top (point 18, fig. 2), where the ruins of the enclosing wall – probably ascribable to the iron age – are still visible today; the other is located on the top of monte s. michele, and dates back to protohistoric times too (point 19, fig. 2). the first (marini, 1985) appears to be the most widely extended hillforts in the area of trieste, and it also reaches the slovene territory. its safe and easily defendable geographic location made the complete building of the enclosing wall unnecessary, because the area was already partially protected by the impervious nature of the environment. from the hypothetical reconstruction of the hillfort of s. michele (canarella, 1989), it can be argued that three defensive concentric walls surrounded it; the only wall that is still visible today is the one enclosing the top of the mountain. the place is likely to have been frequented also during roman times, as the recovering of fibulae belonging to that period demonstrates. at the mouth of the valley, once left the settlement of bagnoli superiore, it is possible to walk along the line of the ancient roman aqueduct for approximately 700 m (point 20, fig. 2). this aqueduct is the only one present in the region: stretching over 14 km, it used to supply the town of tergeste with drinking water. it fed from the fonte oppia (oppia spring, point 13, fig. 2), a spring of water once flowing from the foot of a rock mass located along the rosandra creek, and now flowing from “stone ruins” located below the torrent level, as the british made the ancient rock mass explode during the occupation of trieste. also the “via del sale” (salt road) dates back at least to roman times: its path can still be walked along today on the orographic right of the torrent (point 21, fig. 2). the road was functioning above all during the hapsburg reign, and it served as a link between zaule salt marshes, near the village of muggia, and the towns and the inland villages. the road followed the ridge and also reached the church of s. maria in siariis (xii cen194 f. cucchi et al. fig. 9 gallerie cave. grotta delle gallerie. tury), which was completely restored in 1955, and which is still interesting today for the peculiarity of its location and for the panoramic view: on the orographic right, it is in fact possible to see the viewpoint of moccò (point 14, fig. 2), which rises on the remains of the medieval castle with the same name. built before 1100, it entirely dominated the rosandra valley and enjoyed the beautiful scenery of the gulf. according to the popular tradition, the castle is supposed to have had a gloomy and threatening atmosphere: it was built on a square plan and enriched by a gallery with merlons dominated by a smaller-size construction and by a tower. the location of the ancient castle, which offered an excellent viewpoint on the surrounding valley, made it a most coveted stronghold, above all during the conflicts waged by venice and trieste for the supremacy on commercial traffic. in 1511, the bishop pietro bonomo succeeded in conquering the castle, seizing it from the hands of the venetians; after a short time, the triestines themselves destroyed it to avoid re-conquering by the enemy. in the xvii century, the materials used for the construction of the castle were re-used to build the new castle, always on a square plan, which was seriously damaged immediately afterwards, during world war two and then irreparably destroyed by a fire: today only the foundations can be seen. another castle present in the valley is the draga castle (point 22, fig. 2), initially belonging to the vincumberg family and whose edification began in 1200 and continued until 1400. after passing from the hands of the venetians to the triestines, it was completely abandoned and destroyed in 1600. the castle, linked with the karst ridge through a drawbridge, was certainly connected with the salt road but the successive excavations and the building of the railway obliterated the initial course. today its ruins can be seen on the rocky spur in slovenia. thinking of recent times, the layout of the old railway line needs mentioning (point 3, fig. 2). the old railway line connected the hapsburg port of maria theresa times to vienna and ljubljana; it was started in 1887 and used until 1959. located on the orographic right of the rosandra creek, it is today a classical and beloved path to walk along, offering a wonderful view of the whole valley and leading from s. antonio in bosco and from s. lorenzo both to the villages of draga s. elia and bottazzo. this path is currently being reevaluated, also thanks to its conversion into a cycle-track linking trieste with draga s. elia and with slovenia as far as erpelle. at present, both the rosandra valley stretch (as far as the border between italy and slovenia) and part of the campanelle s. antonio in bosco stretch have already been completed, whereas the town and the slovene stretches will take longer to complete. to conclude this brief but not exhaustive digression on man and the valley, what still needs to be mentioned is the second cai mountain shelter at the lowest altitude in italy: the “rifugio premuda” (point 6, fig. 2). located at the entrance of the rosandra valley, it was opened in 1940, as a legacy of the mountaineering school founded in the thirties by emilio cornici. the valley is still today an important destination for excursionists and nature-lover tourists, for speleologists and mountaineers. 8. conclusions the physical and environmental peculiarities of the rosandra valley were officially recognised by law in 1996, with the regional law no. 042 of 30/9/1996, chapter ii, concerning parks and reserves, which declares "the establishment of the regional natural reserve of the rosandra valley”, defined by art. 2 as “… a territory characterised by a high-level natural and environmental quality, whose conservation aim prevails over other objectives…” in parallel, in compliance with 79/409 and 92/43 eec directives, put into force by the ministerial decree of 3/4/2000, the area is included both in the special protection areas and in the sites of community interest. special protection areas, disciplined in compliance with 79/409/eec directive, are those areas that are suitable – due to their extension and/or geographical location – for the protection of the endangered bird species as referred to in the annex i of the aforementioned directive concerning the protection of bird wildlife. sites of community interest are defined as follows by 92/43/eec directive: “… sites that, within the bio-geographical area/areas they belong to, significantly contribute to the adequate conservation or restoration of natural habitats as described by annex i, or of a species as described by annex ii, and that can furthermore significantly contribute to the coherent approach stated by nature 2000 as referred to in art. 3, and/or that significantly contribute to the protection of biodiversity in the pertinent bio-geographical area/areas”. so far, the rosandra valley has always been attached “special” importance, due to its high environmental value. as previously stated, its park is also a valuable and unique geological, historical and geomorphologic heritage. this is the reason why the valley can be considered a suitable candidate for the geopark status, according to the definition provided by the 29th unesco general conference (paris, october 24 – november 12, 1997): “a geopark is an area that has a peculiar geological heritage and a sustainable territorial development strategy… it ought to include a certain number of extremely important geological elements, in terms of scientific quality, rarity, aesthetic characteristics or educational value. the majority of the areas included in a european geopark are supposed to be part of the abovementioned geological heritage, but their interest can also reside in archaeological, environmental, historical or cultural values”. references cannarella d. (1989) la val rosandra edizioni itinerari carsici 3 edizioni italo svevo, trieste. chersi c. (1984) itinerari del carso triestino tipografia nazionale, 214 pp.. cucchi f., pirini radrizzani c. & pugliese n. (1989a) the carbonate stratigraphic sequence of the karst of trieste (italy) mem. soc. geol. it., 40, pp. 3544. cucchi f., vaia f. & finocchiaro f. (1989b) the geology of t. rosandra valley (karst of trieste, 195geology and geomorphology ... italy) -mem. soc. geol. it., 40, pp. 67-72. cucchi f., potleca m. & zini l. (1998) origin and development of cave system in the rosandra valley (classical karst italy) acta carsologica, ljubljana, 27/2, pp. 63-74. direzione regionale pianificazione territoriale (2003) catasto regionale delle grotte regione autonoma friuli venezia giulia. gherlizza f. halupca e. (1988) spelaues. monografia delle grotte e dei ripari sottoroccia del carso triestino nelle quali sono stati rinvenuti resti di interesse archeologico club alpinistico triestino (gruppo grotte), trieste. hottinger l. (1997) shallow benthic foraminiferal assemblages as signals for depth of their deposition and their limitations bull. soc. géol. fr., paris, 4, (168), pp. 491-505. marini d. (1985) guida alla val rosandra commissione grotte “e. boegan”, tipolitografia mario cozzi, trieste. onofri r. (1982) caratteristiche geolitologiche e geomeccaniche del flysch nella provincia di trieste studi trentini di scienze naturali, acta geologica, 59, pp. 77-103. placer l. (1981) geologic structure of s.w. slovenia geologija, ljubljana, 24/1, pp. 27-60. poldini l. (1989) la vegetazione del carso isontino e triestino. studio del paesaggio vegetale fra trieste, gorizia e i dintorni adiacenti edizioni lint, trieste, 317 pp. poldini l., goldstein m. & martini f. (1978) guida all’escursione botanica della val rosandra edizioni italo svevo, trieste,. 51 pp. poldini l., gioitti g., martini f. & budin s. (1980) introduzione alla flora e alla vegetazione del carso. carsiana (giardino botanico) edizioni lint, trieste, 307 pp. potleca m. (1997) carsogenesi della val rosandra tesi di laurea in scienze geologiche inedita, università degli studi di trieste, 137 pp. regione autonoma friuli venezia giulia, direzione regionale della pianificazione territoriale, & cai club alpino italiano, società alpina delle giulie, commissione grotte eugenio boegan la grotta dei sogni ufficio stampa e pubbliche relazioni della regione autonoma friuli venezia giulia, graphart snc. various authors (1981) convegno internazionale sulla val rosandra (mednarodni seminar o dolini glinščice) bagnoli (boljunec), pp. 178-195, pp. 300-321, pp. 696-720. 196 f. cucchi et al. imp. cinque-irollo iill ““vvuullccaannoo ddii ppoommppeeii””:: nnuuoovvii ddaattii ggeeoommoorrffoollooggiiccii ee ssttrraattiiggrraaffiiccii aallddoo cciinnqquuee11 && ggiioolliinnddaa iirroolllloo11 1dipartimento di scienze della terra, università degli studi “federico ii”, largo s. marcellino, 10 –80138napoli cinque@unina.it. riassunto: cinque a. & irollo g. – il “vulcano di pompei”: nuovi dati geomorfologici e stratigrafici – (it issn 0394 3356, 2004) lo studio geomorfologico e stratigrafico condotto ha permesso di confermare, in modo definitivo, che la collina su cui sorge l’antica pompei, precedentemente ritenuta una forma impostata su lave discese dal somma-vesuvio, rappresenta il relitto di un edificio vulcanico indipendente. esso è parzialmente sepolto dalla falda meridionale del somma-vesuvio e dai depositi che hanno aggradato la prospiciente piana del sarno, nel corso del tardo quaternario. l’ossatura del rilievo principale (“arco della civita”) che si segue, con andamento planimetrico semicircolare, dalla località sette termini fino al limite se della antica pompei, è formata da colate laviche e prodotti di attività stromboliana (tra cui una tipica foam lava segnalata già da vitruvius) che si sovrappongono ad un rilievo a tufi e piroclastiti sciolte, già all’epoca fagliato ed eroso. all’arco della civita si associano, inoltre, piccoli edifici prevalentemente scoriacei (cratere di via di stabia, rilievo di s. abbondio) che sembrano ubicarsi lungo fratture anulari, più o meno coassiali con l’edificio principale. a punti di emissione analoghi possono, infine, riferirsi almeno parte delle lave ritrovate nel sottosuolo della piana poco a s e se della collina pompeiana. la metà orientale del composito edificio vulcanico (non affiorante) potrebbe essere stata ribassata di alcune decine di metri da una faglia orientata all’incirca nw-se. una importante faglia e-w, che ribassa di un migliaio di metri verso n il substrato pre-quaternario della piana del sarno, sembra, invece, costituire il motivo strutturale che controlla l’ubicazione dell’intero apparato pompeiano. la frazione dell’edificio a tufi e piroclastiti è, al momento, di difficile datazione, anche se l’analisi dei suoi rapporti con altre unità del sottosuolo suggerisce un’età post ignimbrite campana (39 ka) e, forse, posteriore anche ad una fase di dissezione della piana del sarno occorsa durante l’ois 2. la successiva fase ad attività stromboliana ed emissioni laviche ricopre un intervallo temporale che va da oltre 19 ka (lave presso la porta nocera) fino all’olocene antico quando le ultime colate discendenti lungo il fianco s e sw della collina pompeiana si intercalarono ai sedimenti trasgressivi versiliani della bassa piana del sarno. abstract: cinque a. & irollo g. – the “pompeii volcano”: new geomorphological and stratigraphical data – (it issn 0394 3356, 2004) by means of both detailed geomorphological investigations and analysis of pre-existing drilling data, the small hills occurring in the area of pompeii (province of naples; italy) have been definitely recognized as volcanic landforms and attributed to the activity of local vents. the main relict of what we call the pompeii volcano consists in a crescent-shaped ridge (“arco della civita) that is tentatively interpreted as the remnant of an ancient volcanic ring. it stretches from sette termini, near boscoreale, to the archaeological site of the ancient town of pompeii. further to the north, it is buried by lavas and pyroclastics forming the southern piedmont of somma-vesuvius volcano. southwards it is buried by the late quaternary sediments of the sarno rives alluvial coastal plain. the eastern half of the ancient ring, which does not crop out, may have been lowered by some tens of meters because of a se-trending normal fault. a geological section across the arco della civita crescent, shows that the structure has a core of tuffs and loose pyroclastic beds; suggesting that the initial activity of pompeii volcano was essentially explosive. this pyroclastic edifice was then locally covered by lava flows and scoria (leucite bearing tephrites) coming from a number of local vents, among which is the small s. abbondio cone and, probably, the one we named via di stabia crater. their products (such as the typical foam lava, already known to vitruvius) were abundantly utilized as building materials in ancient pompeii. on the base of their relations with other dated formations, the various emissions of lava appear to vary in age from place to place: they are older than 19 ky close to porta nocera and early holocene in age (likely 8÷6 ka) in the sw flank of the pompeian hill where the lava flows interfinger with the transgressive versilian sediments of the lower sarno river plain and appear cut by a sea-cliff to be acribed to the peaking stage of the same post-glacial trasgression. more difficult to date is the explosive activity which occurred before lava and scoria emissions. some sub-surface stratigraphic data prove that it is not older than the tyrrhenian stage (ois 5) and possibly younger than the ois 3. other stratigraphical and palaeomorphological data suggest that the explosive activity of pompeii volcano occurred when the campanian ignimbrite (39 ka) had already been dissected by the sarno river. the existence and the position of the studied volcano can be connected to an important e-w trending normal fault which is perfectly buried by the thick quaternary fill of the sarno plain, but nicely revealed by gravimetric and magnetic anomalies. this fault lowers the substrate of the plain (mesozoic to neogene units of the apenninic chain) by approximately one thousand meters to the north and it can be followed from nocera inf. to torre annunziata. the pompeii volcano could be at the intersection of this fault with another, nw trending regional fault or with a radial fracture of the somma-vesuvius volcano. parole chiave: geomorfologia vulcanica; tardo quaternario; apparato del somma-vesuvio. keywords: volcanic geomorphology; late quaternary; somma-vesuvius volcano. il quaternario italian journal of quaternary sciences 1177(1), 2004, 101-116 102 a. cinque & g. irollo 11 - iinnttrroodduuzziioonnee i resti dell’antica città di pompei, fondata intorno al vi secolo a.c. da popolazioni osche e distrutta dalla celebre eruzione vesuviana del 79 d.c., sorgono su un rilievo collinare che, sebbene di modesta altezza (quota massima 54 m s.l.m.), ben si staglia sulla circostante pianura alluvionale costiera del fiume sarno. verso nw la collina pompeiana si fonde quasi perfettamente col piedimonte dell’edificio vulcanico del somma-vesuvio (fig. 1) e ciò ha a lungo indotto a considerarla come una forma impostata su colate laviche discese da tale edificio. questa interpretazione è indicata anche nel foglio n. 185 “salerno” della carta geologica d’italia, il quale include le lave presenti nell’area pompeiana in un’unità cartografica [β: lave protostoriche, (ottavianiti augitiche), in parte sepolte nella pianura] che raggruppa numerose colate provenienti dal somma-vesuvio. come sarà meglio illustrato nel terzo capitolo, alcuni autori (ippolito, 1962; di girolamo, 1969; cinque, 1991; di vito et al., 1997, 1998a-b) hanno successivamente fornito indicazioni che fanno invece propendere per un’origine locale delle vulcaniti formanti l’ossatura della collina pompeiana. il presente lavoro intende contribuire alla conoscenza geologica dell’area di pompei ed in particolare ad accertare l’esistenza di un edificio vulcanico locale ed a definirne la morfologia. si è tentato, inoltre, di fornire un preliminare inquadramento cronologico delle vulcaniti pompeiane, basandosi sui loro rapporti stratigrafici e geomorfologici con marker piroclastici regionali e con gli episodi eustatici trasgressivi che hanno interessato l’area di studio nel corso del tardo quaternario. la ricerca, svolta senza finanziamenti specifici, non ha potuto avvalersi di sondaggi ed analisi realizzati allo scopo, basandosi, invece, su un attento rilevamento geologico e geomorfologico, nonché sulla raccolta e rielaborazione di preesistenti dati stratigrafici, petrografici, geocronologici e geofisici. l’ampio ricorso a dati di sottosuolo è motivato dalla pressoché totale copertura degli intervalli di interesse da parte di unità sedimentarie e piroclastiche più recenti. nell’area dell’antica pompei, dove la copertura è più esigua, alcune informazioni sui litotipi che formano l’ossatura della collina sono state ricavate da relazioni di scavo e sondaggio archeologici. l’analisi geomorfologica è stata basata, oltre che su osservazioni dirette, sulla interpretazione di foto aeree e sull’esame di carte topografiche in scala 1:5000, 1:2000 e, per l’area degli scavi di pompei, 1:500. 22 - iinnqquuaaddrraammeennttoo ggeeoollooggiiccoo ddeellll’’aarreeaa l'area di studio si colloca nella zona di raccordo tra le pendici sud-occidentali del somma-vesuvio e la piana alluvionale costiera del fiume sarno (fig. 1). essa ricade nella parte meridionale della ampia depressione tettonica nota in letteratura come graben campano (ippolito et al., 1973; ortolani & aprile 1978), la cui parte settentrionale, al di là del somma-vesuvio e dei campi flegrei, è occupata dalla ben più vasta piana del volturno. il graben campano ribassa le unità della catena sud-appenninica fino a circa 3000 m sotto il livello del mare e deve la sua origine a fagliazioni estensionali occorse a partire dal pleistocene inferiore (brancaccio et al., 1991). la subsidenza è stata accompagnata da una attività vulcanica alimentata da magmi inizialmente di tipo calc-alcalino (vulcani profondamente sepolti sotto la pianura) e poi di tipo k-alcalino (edifici tardo quaternari oggi visibili: campi flegrei, somma-vesuvio, vulcani delle isole di nisida, procida, vivara ed ischia) (barbieri et al., 1979; bernasconi et al., 1981; brocchini et al., 2001). oltre che ai prodotti vulcanici, il parziale colmamento della depressione, ovvero la nascita della piana campana, va imputato all’accumulo di una potente successione sedimentaria alimentata dagli apporti dei fiumi appenninici. come mostrano le facies attraversate da alcuni sondaggi profondi (ippolito et al., 1973; barbieri et al., 1979; romano et al., 1994; barra et al., 1996) nel corso del quaternario il graben è stato spesso sede di un golfo marino che, influenzato dalle interferenze tra eustatismo e subsidenza, si è spinto più volte fino alla base, o quasi, dei primi rilievi appenninici. a seguito della regressione dell’ultimo massimo glaciale, la linea di costa avanzò fino al ciglio della piattaforma continentale, che, al largo dell’area di studio (golfo di napoli), si trova a circa 20 km oltre la costa attuale (milia & torrente, 1999). tale ingente avanzamento della linea di riva fu anche favorito dagli accresciuti ritmi di colmamento vulcanico e sedimentario (crescita dell’edificio del somma-vesuvio, eruzione della potente ignimbrite campana, estendersi dei conoidi alluvionali discendenti dai monti lattari). la conseguente aggradazione della piana impedì, quindi, alla trasgressione versiliana di produrre un’ingressione paragonabile a quella del precedente interglaciale. infatti la paleolinea di riva versiliana più interna (associata a torbe datate 5,6 ka; cinque, 1991) si spinge solo fino all’altezza di scafati, mentre successivi lineamenti costieri marcano la progressiva progradazione, avvenuta nel corso dell’olocene recente, nonostante una contemporanea subsidenza al ritmo medio di circa 2 mm/a (cinque, 1991). per la datazione degli eventi che hanno interessato l’area nel corso del tardo-quaternario, particolare utilità rivestono alcuni livelli guida connessi ad eruzioni esplosive di età nota. i più antichi tra questi marker sono l’ignimbrite di taurano (157 ka circa, rolandi et al., 2000) e la potente ed estesa ignimbrite campana, o tufo grigio campano (i. c.) datata recentemente a circa 39 ka (rolandi et al., 2000; de vivo et al., 2001), a composizione trachitica. alcuni autori ne connettono la genesi al collasso della caldera flegrea (rosi & sbrana, 1987; orsi et al., 1996; civetta et al., 1997); altri la attribuiscono, totalmente o parzialmente, ad eruzioni fissurali lungo faglie dissecanti più ampie porzioni della depressione campana (scandone et al., 1991; cinque et al., 1997; rolandi et al., 2003). tra i marker tefro – stratigrafici potenzialmente utili in questo lavoro, vanno poi considerati, il tufo giallo napoletano, datato a circa 12 ka (scandone et al., 1991) ed alcune grandi eruzioni pliniane del somma – vesuvio, quali quelle “di codola” (circa 25 ka, arnò et al., 1987), “di sarno” o delle pomici di base (19 ka, bertagnini et al., 1996), delle “pomici verdoline” (circa 17 ka, arnò et al., 1987), “di ottaviano” o “di mercato” (8 ka, rolandi et al., 1993), “di avellino” (circa 3,6 ka, arnò et al., 1987) e “di pompei” (79 d.c.) (andronico et al., 1995; 96; arnò et al., 1987). 103il “vulcano di pompei”: nuovi dati geomorfologici e stratigrafici fig. 1 schema geomorfologico dell’area pompeiana. main geomorphological features of pompeii area. 104 33 -pprreecceeddeennttii ccoonnoosscceennzzee ssuullllee ffoorrmmaazziioonnii vvuullccaanniicchhee ddeellll’’aarreeaa ppoommppeeiiaannaa un primo riferimento ai materiali lavici affioranti nell’area di pompei, ed utilizzati per la realizzazione di opere murarie, emerge già nel trattato “de architectura” (ii, vi, 2) di vitruvius laddove l’autore parla della “spongia, sive pumex pompeianus”. il termine spongia compare in vitruvius solo in questo passo ed è assente negli autori latini ed in particolare nella “naturalis historia” di plinius1. ruggiero nel 1879 indica, nella città antica, la presenza di una lava compatta nel teatro coperto e nel triclinio della casa 3, reg. 1, ins. 2, (“e” in fig. 2) simile a quella ritrovata in un pozzo, lungo la strada di sette termini, nella vigna cerulli, ad un chilometro circa da pompei, e definita leucitite porfirica, con abbondanti cristalli di augite e più rari di leucite. descrive, inoltre, un termine scoriaceo nella “ripa di mezzogiorno”, sotto il tempio greco, ed in quella occidentale, rilevando le analogie delle scorie pompeiane con i prodotti che si cavavano a pollena, lungo le opposte pendici del vesuvio. nicotera (1950) analizza in dettaglio e classifica le rocce utilizzate a pompei come materiali da costruzione e per i lastricati stradali. sottolinea inoltre l’importanza del substrato lavico della collina per le opere di fondazione degli edifici e l’uso differenziato, in campo edilizio, dei materiali di risulta delle operazioni di scavo e di coltivazione delle cave. in tempi più recenti di girolamo (1968; 1969) descrive lungo la paleofalesia che margina a meridione il sito archeologico (“a” in fig. 2) delle lave vacuolari e scoriacee, di colore rosso e con fenocristalli di leucite, augite ed olivina. l’autore le classifica come “tefriti leucitiche a tendenza basanitica” e vi riconosce i caratteri tipici di foam lava prossimale, da attribuire ad una bocca eruttiva locale. lo stesso di girolamo (1963) segnala, nella zona dell’anfiteatro, (“c” in fig. 2) anche un livello lavico di colore grigio, a tessitura compatta e con composizione affine che evidenzia analogie di carattere chimico, fisico e petrografico con la colata di castello di cisterna, alla base del versante orientale del somma-vesuvio. nella successione stratigrafica ricostruita per pompei la colata dell’anfiteatro è, secondo di girolamo (1968), antecedente alla foam lava. la sovrapposizione di termini lavici scoriacei su quelli compatti, oltre ad emergere da molti dati di sottosuolo qui presentati (vedi oltre), è stata riconosciuta anche da rolandi et al. (1997) lungo il margine meridionale della stessa collina pompeiana. essa è stata rilevata, ancora, all’interno di un pozzo per acqua realizzato nella “casa dei vasi di vetro” nel 1931 (sondaggio "po2a" in fig. 2 e 3) ed in un pozzo di età classica adiacente a porta vesuvio (sondaggio "po2b" in fig. 2 e 3) (ippolito, 1938; 1962; nicotera, 1950; maiuri, 1973). secondo ippolito (1938) le lave di porta vesuvio sono simili a quelle affioranti, in forma più alterata, sotto il foro triangolare e nella “casa di giuseppe ii” (rispettivamente “g” ed “h” in fig. 2), nonché analoghe a quelle di castello di cisterna. tali analogie suggeriscono all’autore una attribuzione all’attività del somma recente. anche secondo bellucci (1998), nell’immediato sottosuolo dell’area di pompeiscafati sarebbe riconoscibile un complesso delle “lave del somma” che l’autrice descrive come una sequenza di colate laviche intervallate da livelli di scorie, che solo presso ottaviano e boscotrecase reca alla base depositi piroclastici riconducibili all’eruzione di codola, mentre altrove risulta direttamente sovrapposta all’ignimbrite campana. come si argomenterà più avanti, l’attribuzione a tale complesso delle lave affioranti sulla collina pompeiana appare poco sostenibile. l’ipotesi di un’origine somma-vesuviana potrebbe, invece, restare valida per almeno parte delle lave che ricorrono nel sottosuolo della piana, ad e e ne della stessa collina (vedi paragrafo 5.3 b). tali lave sepolte sono state segnalate anche da ruggiero, (1879); luongo & rapolla (1964); di girolamo (1969) e di vito et al. (1997; 1998a) i quali forniscono interessanti stratigrafie di sondaggio che hanno contribuito alle ricostruzioni presentate nel capitolo 5. per quanto riguarda i terreni presenti alla base delle lave pompeiane, ippolito, (1962) analizzando la stratigrafia del pozzo della casa dei vasi di vetro (sondaggio “po2a” fig. 2-3), fa notare che l’unità tufacea grigia, che è sottoposta alle due colate laviche, non può essere ascritta all’i. c. per riscontrate differenze chimiche, per l’abbondanza di clasti metamorfosati di calcare (della grandezza di un pugno) e di scorie, di dimensioni e frequenza tali da indurre l’autore a ritenere questo tufo di origine locale (distanza della bocca eruttiva valutabile in pochi chilometri). di diverso avviso sono di girolamo (1968) e rolandi et al. (1997) i quali, pur senza fornire nuovi dati analitici, correlano quel tufo alla ignimbrite campana. quanto ad indicazioni cronologiche, cinque & russo (1986) e cinque (1991) dimostrano che le lave e la collina di pompei precedono cronologicamente l’apice trasgressivo versiliano, mentre rolandi et al. (1997) segnalano che presso la porta nocera (scavi di pompei, “b” in fig. 2) le lave sono coperte da un livello di pomici da fall affini a quelle dell’eruzione “sarno”(19 ka). di vito et al. (1998a) forniscono delle misure di radiocarbonio che datano a circa 18 e 20 ka i paleosuoli intercalati alle lave in alcuni sondaggi effettuati lungo il confine meridionale della collina pompeiana (vedi discussione al capitolo 6). circa i termini che sono sottoposti alle lave in questione, dai quali potrebbero essere ricavati dei limiti di età massima per le stesse, rolandi et al. (1997) ipotizzano che le pomici presenti alla base delle lave nel pozzo della casa dei vasi di vetro (sondaggio “po2a” fig. 2-3) siano attribuibili all’eruzione di “codola” (circa 25 ka), mentre ippolito (1962), riporta l ’attr ibuzione di rittmann al tufo giallo napoletano (circa 12 ka) del livello tufaceo immediatamente sottostante a tali pomici. per quanto concerne la morfologia associata alle vulcaniti pompeiane, il primo lavoro che riconosce nella collina di pompei scavi i resti di un edificio vulcanico distinto dal somma-vesuvio si deve a cinque (1991), il quale presenta tale interpretazione in una carta dedicata all’evoluzione tardo-quaternaria della piana del sarno. successivamente di vito et al. (1997) parlano di un “apparato eccentrico pompeiano” e d’ambrosio et al. (2001) riconducono a centri eruttivi locali le rocce scoriacee con proietti rinvenute in sondaggi sulla piana, effettuati lungo l’autostrada napoli-salerno. gli stessi autori individuano prodotti simili a quelli dell’area pom1secondo l’interpretazione del prof. maurizio bugno (università degli studi di napoli federico ii) quell’aspetto che la faceva riconoscere col termine scientifico e tecnico di pumex poteva localmente essere riconosciuto come spongia. a. cinque & g. irollo 105 f ig . 2 t op og ra fia d i d et ta gl io d el l’a re a ar ch eo lo gi ca d i p om pe i e te nt at iv o di in te rp re ta zi on e ge om or fo lo gi ca . d et ai le d to po gr ap hi c m ap o f p om pe ii ar ch ae ol og ic al s ite w ith a n at te m pt o f g eo m or ph ol og ic al in te rp re ta tio n. il “vulcano di pompei”: nuovi dati geomorfologici e stratigrafici 106 f ig . 3 c ol on ne s tr at ig ra fic he d i a lc un i d ei s on da gg i p re gr es si u til iz za ti ne l p re se nt e st ud io ( la te rm in ol og ia u til iz za ta in le ge nd a è qu el la o rig in al e de lle d es cr iz io ni s tr at ig ra fic he ; v ed i t es to p er la r ei nt er pr et az io ne ). s tr at ig ra ph y of s om e pr eex is tin g w el l-l og s us ed in th e pr es en t s tu dy ( te rm s us ed c or re sp on d to th e or ig in al d es cr ip tio ns o f w el l-l og s; s ee te xt fo r re -in te rp re ta tio ns ). a. cinque & g. irollo peiana nel sottosuolo di scafati, ove ipotizzano l’esistenza di morfologie vulcaniche sepolte. 44 - oosssseerrvvaazziioonnii ggeeoommoorrffoollooggiicchhee come evidenziato in figura 1 l’area in esame può essere suddivisa nelle seguenti unità geomorfologiche principali: a) iill ppiieeddiimmoonnttee ssoommmmaa--vveessuuvviiaannoo, la cui geometria fondamentale ha simmetria radiale e profili trasversali dolcemente concavi (pendenze massime, a monte, intorno al 6%). esso raccorda lo strato-vulcano alla pianura e deriva da accumuli di deiezioni torrentizie alternate a piroclastiti da caduta e da flusso. a luoghi, in particolare nelle sue parti più prossimali, si notano dossi dovuti a colate laviche storiche e, poco fuori dell’area mappata in figura 1 a coni di scorie. b) llaa ppiiaannuurraa aalllluuvviioonnaallee ee ccoossttiieerraa ddeell ffiiuummee ssaarrnnoo, che ha una pendenza media, verso wsw, dello 0.2÷0.3% ed appare priva di sensibili articolazioni morfologiche. nella parte più occidentale della piana si individuano dei modesti dossi allungati in direzione nw-se (attenuati da successive aggradazioni alluvionali e piroclastiche e dalle azioni antropiche), che rappresentano paleocordoni costieri dell’olocene recente e si alternano a fasce sub pianeggianti corrispondenti a depressioni retrodunari. verso s e se, oltre i limiti della mappa di figura 1 la piana passa ai conoidi di deiezione che marcano il piedimonte dei monti lattari. c) ii rriilliieevvii ccoolllliinnaarrii ddeellll’’aarreeaa ppoommppeeiiaannaa, che appaiono come entità distinte dalle due precedenti e la cui geomorfologia è dettagliatamente descritta in seguito. d) llaa ppaalleeooffaalleessiiaa vveerrssiilliiaannaa che, nella zona di torre annunziata, taglia il piedimonte somma-vesuviano (cinque & russo, 1986) mentre, più ad oriente intacca, alla base, i rilievi della unità “c” e, fuori dall’area mostrata in figura 1, i sopra citati conoidi dei m. lattari. modellatasi durante la risalita eustatica postglaciale, essa è stata progressivamente disattivata, da e verso w, con le pulsazioni progradazionali che hanno caratterizzato la piana nel corso della seconda metà dell’olocene (cinque 1991). analizzando più in dettaglio i rilievi collinari pompeiani vi si possono distinguere un elemento nord occidentale, di maggiore altezza ed estensione, che denominiamo “arco della civita” e, ad e ed a se dello stesso, alcuni rilievi di estensione ed altezza più modeste quali il dosso presso il cimitero di pompei, il colle s. bartolomeo e la collinetta di s. abbondio. l’arco semicircolare della civita si estende dalla culminazione di sette termini (54 m s.l.m.) fino all’area archeologica di pompei. esso sovverte il regolare declivio verso sud del piedimonte somma-vesuviano disegnando una modesta risalita topografica (da cui la sella tra boscoreale e sette termini) ed inducendo un deciso cambiamento di orientazione delle isoipse. tale arco è caratterizzato da quote approssimativamente costanti lungo il suo sviluppo, a differenza del piedimonte vesuviano che declina regolarmente verso s. la prominenza del primo sul secondo è quindi chiara verso meridione e diviene progressivamente meno pronunciata in direzione di boscoreale. la geomorfologia della zona di contatto suggerisce abbastanza chiaramente che sono i materiali costituenti il piedimonte somma-vesuviano ad accavallarsi su quelli che formano l’arco della civita, sebbene non sia da escludere che, ad una certa profondità, i termini più antichi dell’edificio somma-vesuviano siano soggiacenti a quelli dell’arco stesso. il fianco esterno di quest’ultimo declina in modo radiale centrifugo con pendenze del 3÷6%. nel tratto compreso tra villa di diomede e porta di stabia (fig. 2) il pendio citato è tagliato alla base da un elemento più ripido -a luoghi sub-verticale-, che corrisponde alla già citata paleofalesia versiliana. per i rapporti con le paleolinee di riva datate nella bassa piana del sarno (cinque, 1991) si può ritenere che questo tratto di paleofalesia sia stato attivo durante l’olocene medio, per divenire poi una falesia morta con la crescita del paleocordone di bottaropioppaino (databile tra circa 3,6 e 2,5 ka). il fianco interno dell’arco ha un andamento all’incirca parallelo a quello esterno e declina in modo centripeto con pendenze del 3÷5%. nel settore tra civita giuliana e pompei scavi, tale fianco discende verso una zona piatta ed a contorno semi-circolare indicata col significativo toponimo di fossa di valle (quota minima 18 m circa s.l.m.). quest’ultima doveva essere in origine più profonda, e forse anche endoreica, essendo stata certamente interessata da recenti fasi aggradazionali, connesse alla potente eruzione del 79 d.c., alla trasgressione versiliana sulla limitrofa piana del sarno ed, infine, alla crescita del piedimonte vesuviano. un’apofisi di quest’ultimo penetra, infatti, da e nella depressione. l’insieme dei dati geomorfologici fin qui esposti appare già sufficiente a far riconoscere, nell’arco della civita, il relitto parziale (la metà occidentale) di un edificio vulcanico sub circolare il cui diametro apparente, misurato lungo l’attaccatura della pianura circostante, che in parte lo seppellisce, è stimabile intorno a 3 km. la reale altezza dell’edificio è certamente superiore al suo aggetto attuale sulla piana (circa 35 m), che ha subito sensibili fasi di aggradazione dopo la crescita dell’edificio stesso (vedi oltre). il basso morfologico di fossa di valle, sottodimensionato e decentrato rispetto all’arco della civita, può interpretarsi come il relitto di una depressione vulcanica minore, piuttosto che come espressione della depressione centrale dell’intero edificio. d’altra parte, la geomorfologia dell’area presenta diversi altri elementi a favore di una polifasicità dell’edificio, accompagnata da migrazioni delle attività costruttive e distruttive. ad esempio, nella zona a nord di fossa di valle, il rilievo isolato che denominiamo colle del cimitero (37 m s.l.m. fig. 1) sembra doversi interpretare come un lembo ribassato ed eroso del substrato a tufi e piroclastiti sciolte dell’edificio principale. a favore di tale ipotesi vi sono sia dati stratigrafici e giaciturali, (vedi capitolo seguente), sia un’incisione che sembra rimarcare, in susseguenza, una faglia nne ssw, tra detto colle e l’arco della civita (fig. 1). la collinetta di s. abbondio (18 m s.l.m. fig. 1) va attribuita all’attività costruttiva di una bocca eruttiva minore, sia per il suo ergersi isolata all’esterno del cerchio ricostruibile estrapolando l’arco della civita, sia in base a evidenze di ordine geologico fornite nel successivo capitolo. tracce di un altro possibile centro eruttivo secondario sono emerse all’interno del perimetro della città antica di pompei, ove è stata preliminarmente ricostruita la morfologia pre-scavo archeologico, su carte topografiche in scala 1:500 (aavv, 1994), sommando ai dati altitudinali lo spessore della coltre piroclastica asportata (5 107il “vulcano di pompei”: nuovi dati geomorfologici e stratigrafici m circa nel settore meridionale dell’area e 4 m circa in quello settentrionale) e considerando le modifiche indotte dagli stessi lavori di scavo (maiuri, 1960). come riportato in figura 2 la topografia così ricostruita evidenzia una forma semicircolare concava che suggerisce l’esistenza di un cratere secondario rispetto al più grande arco della civita (cratere di via stabia), troncato a s dalla falesia versiliana. sempre nell’ambito dell’area che fu occupata dall’antica pompei, si osserva un’ampia forma lobata che si allunga verso ese, con quote che decrescono dai 38 m della zona all’altezza di porta di nola a 22 m nell’area di palestra grande e dell’anfiteatro (rispettivamente“d” e “c” in fig. 2). questo lobo ha la sommità quasi appiattita e, sebbene non si possano escludere spianamenti antropici connessi alle fasi di antica urbanizzazione, si può ritenere credibile l’ipotesi che la sua forma complessiva sia da imputarsi ad espandimento di colate laviche, quali quelle individuate nel pozzo di palestra grande (luongo & rapolla, 1964), a porta di sarno, e presso l’anfiteatro. l’analisi geomorfologica ha consentito di riconoscere, oltre alle forme di origine vulcanica, diversi indizi di fagliazione diretta ascrivibili ad un’attività tettonica esplicatasi dopo la crescita dell’edificio vulcanico pompeiano e probabilmente anche durante la stessa. a tal proposito va citata, in primo luogo, la mancata evidenza morfologica della metà orientale dell’edificio, la quale va verosimilmente imputata ad un ribassamento (seguito da seppellimento) lungo una faglia con orientazione circa nw-se. (fig. 1). un’altra possibile faglia è quella, già citata, che separa il dosso del cimitero dall’arco della civita (fig. 1 e 4). lungo il regolare fianco esterno di quest’ultimo, nella zona di porta ercolano, è stata poi riscontrata una incisione ad andamento anomalo (non radiale) che potrebbe essere impostata lungo una faglia che si allunga da w verso se e ribassante, 108 fig. 4 sezione stratigrafica trasversale all’arco della civita (traccia in fig. 1). i sondaggi utilizzati sono quelli eseguiti dalla geosond soc. coop. a.r.l. nel 1989, ad eccezione di cg 64). geological section across the arco della civita (see fig. 1 for location). all drillings but cg 64 derive from the work carried out by geosond soc coop a.r.l. in 1989. a. cinque & g. irollo probabilmente di pochi metri, verso ne così da catturare e deviare i ruscellamenti centrifughi del pendio vulcanico (fig. 2). infine la faglia anulare che disegna o rinvigorisce il fianco interno dell’arco principale (fig. 1-4). 55 - ddaattii ssttrraattiiggrraaffiiccii sono stati raccolti ed interpretati numerosi dati geologici, relativi sia ad affioramenti, naturali ed artificiali, che a sondaggi meccanici eseguiti in passato sulla collina pompeiana e nei suoi dintorni, per ricerche idriche, per palificazioni e per la realizzazione di opere pubbliche. in totale sono state analizzate più di 200 stratigrafie di sondaggio l’ubicazione della maggior parte delle quali è mostrata nelle figure 1, 2, 7, 8 e 9. le stratigrafie di maggior interesse e complessità sono riportate in figura 3, mentre altre vengono riassunte nel testo. non sono invece citate, per motivi di brevità, quelle stratigrafie di sondaggio risultate utili solo a determinare la presenza di lave sepolte e le loro quote. in questo capitolo si esaminano i dati stratigrafici raccolti, raggruppandoli per aree e per temi. 55..11 - sseezziioonnee aattttrraavveerrssoo ll’’aarrccoo ddeellllaa cciivviittaa utilizzando congiuntamente dati di affioramento, osservazioni geomorfologiche e dati litostratigrafici e giaciturali emersi durante lo studio e la realizzazione di una galleria lungo il canale conte di sarno (cogefar impresit s.p.a.; geosond soc. coop. a.r.l., 1989), è stato possibile costruire una sezione geologica trasversale all’arco della civita (fig. 4). in essa sono riconoscibili, separate da linee di maggior spessore, le unità che disegnano l’ossatura del rilievo (indicate con le sigle ssll e ttpp ed in seguito richiamate anche come “unità di substrato”) e quelle che, invece, lo ammantano in modo isopaco o determinando locali addolcimenti dei pendii e dei dislivelli (indicate con la sigla mm in fig. 4 ed in seguito richiamate anche come “unità di copertura”). il complesso mm, spesso tra gli 8 ed i 10 m, comprende, dall’alto verso il basso: (a) suoli attuali; (b) alluvioni e colluvioni piroclastiche; (c) prodotti in giacitura primaria della eruzione del 79 d.c. sotto questi ultimi si osservano (d) sabbie piroclastiche e cineriti con tetto humificato ed altre tracce di pedogenesi intercalate. esse potrebbero rappresentare più antiche eruzioni pliniane del sommavesuvio, in analogia con quanto segnalato in affioramento da rolandi et al. (1997) presso porta nocera e da mastroroberto (1998) a s. abbondio (vedi capitolo 3). nel basso morfologico che separa la collina della civita dal dosso del cimitero il complesso di copertura poggia su depositi limo-sabbiosi nerastri e pozzolane (e) che sembrano rappresentare un antico riempimento alluvionale. questi depositi appaiono, a loro volta, dissecati e la nuova incisione è riempita dall’unità (d) del complesso di copertura. per quanto concerne il substrato, si osserva che nella parte centrale della sezione (località civita giuliana), la sua parte sommitale è caratterizzata da sabbie sciolte o poco addensate, con lapilli, per lo più di colore rossastro che poggiano in maniera concordante su un’unità a scorie e brandelli lavici immersi in matrice sabbiosa. questa unità fa a sua volta passaggio, per intercalazioni, a sottostanti lave. esse sono descritte generalmente come ricche di fenocristalli, compatte, ma anche con struttura vacuolare. le lave formano due o più colate, inclinate conformemente ai fianchi dell’arco della civita, e mancano nel tratto di sezione a ene del sondaggio cg14. i sondaggi cg22, cg23 e cg64 evidenziano, a letto delle lave, un complesso mai segnalato prima, formato da tufi gialli e grigi a luoghi alterati, sabbie grossolane con pomici e pozzolane (unità ttpp di fig. 4 spessore minimo 20 m circa) la cui base, mai raggiunta, è ad almeno 20 m sotto il livello marino. a nostro avviso, tale complesso potrebbe rappresentare il frutto delle più antiche eruzioni del vulcano pompeiano. esso equivale quasi certamente all’unita tufacea, coperta dalle lave, dei pozzi della casa dei vasi di vetro e porta vesuvio nell’area archeologica pompeiana (po2a-b in fig. 2-3). sia dalla sezione di figura 4 che da altri dati di sottosuolo appare chiaro che il complesso ttpp delinea un antico alto morfologico, al cui andamento si adegua, nel tratto più occidentale della sezione, quello delle colate. nella parte centrale della sezione, invece, le lave immergono in direzione opposta a ttpp, la cui stratificazione continua ad immergere verso occidente anche nel dosso del cimitero. questa uniformità di giacitura consente di interpretare tale dosso come un lembo smembrato dell’arco della civita, piuttosto che come un piccolo edificio a sé. 109 fig. 5 i prodotti del cono di s. abbondio emersi in affioramento lungo l’autostrada napoli-pompei-salerno. the scoria and ejecta of the s. abbondio cone as exposed during the works to enlarge the napoli-pompeii-salerno motorway il “vulcano di pompei”: nuovi dati geomorfologici e stratigrafici 55..22 - ddaattii ssuullllee bboocccchhee eerruuttttiivvee mmiinnoorrii anche per l’area di s. abbondio (fig. 1) sono stati raccolti dati che confermano le ipotesi tracciate su basi geomorfologiche. in particolare, il fatto che questa collinetta sia strettamente collegata ad una locale bocca eruttiva è supportato dai caratteri molto prossimali delle vulcaniti che ne costituiscono l’ossatura, osservate in un taglio effettuato durante i lavori di ampliamento dell’autostrada napoli-pompei-salerno. sono livelli fortemente clinostratificati di scorie schiumose spesso saldate, di colore variabile tra il rossastro ed il nerastro e con frequenti fenocristalli di leucite (fig. 5). vi si rinvengono inglobati sia blocchi rigettati di lave compatte, che giungono fino a diversi decimetri di diametro, sia brandelli di sedimenti marini (limi sabbiosi giallastri poco consolidati) di dimensioni prossime al decimetro. per essere giunti integri alla superficie e per il fatto che recano modesti segni di “cottura”, questi sedimenti sono stati presumibilmente strappati alle formazioni litorali tardo pleistoceniche presenti a poche decine di metri di profondità (capitolo 6 e fig. 3). una provenienza dal complesso versiliano sembra invece da escludersi perché le sabbie litorali oloceniche sono, di norma, nerastre per la grande abbondanza di minerali femici vesuviani. si ricorda, inoltre, che sulla collina di s. abbondio è stata rinvenuta una necropoli dell’età del bronzo con tombe scavate nelle scorie e sepolte poi da prodotti piroclastici attribuiti alla eruzione somma-vesuviana “di avellino” (circa 3,6 ka; mastroroberto, 1998). circa la probabile forma craterica evidenziata nella zona di pompei scavi (“cratere di via stabia”), i dati geologici che avallano questa ipotesi geomorfologica sono in primo luogo le giaciture delle lave leucitiche scoriacee che affiorano nella paleofalesia versiliana. infatti, tra porta marina (inf) e porta di stabia (fig. 6), la lave hanno un’immersione convergente verso il settore ove sorge la casa di giuseppe ii ("h" in fig. 2). a ciò si aggiunge il fatto che il tetto delle lave si deprime verso il centro della forma in questione, come dimostrano i dati emersi dai saggi realizzati nella casa dei postumii2 (viii, 4, 49), nell'area del portico del foro triangolare e nella casa di "giuseppe ii" (viii, 2, 39)3 (rispettivamente "f" "g" "h" in fig. 2). l’analogia tra le lave di porta vesuvio e quelle affioranti, anche in forma più alterata, sotto il foro triangolare e nella “casa di giuseppe ii” era stata già indicata da ippolito (1938). ulteriori dati relativi alla quota del tetto delle lave lungo il margine orientale del cratere si ricavano dai sondaggi eseguiti nell’insula dei casti amanti (ix,12) (patti, 2003) (“l” in fig. 2). lungo il margine settentrionale del cratere le campagne di scavo archeologico, condotte nel 2003 dall’università degli studi di napoli “l’orientale”, sotto la guida del prof. fabrizio pesando, hanno rivelato, nella reg. vi, un paleosuolo di età arcaica (con tracce di frequentazione umana) che marca una paleotopografia inclinata vero n. tale declivio fu mascherato dalle ultime eruzioni protostoriche del somma – vesuvio, da interventi antropici di età classica ed, infine, dall’eruzione del 79 d.c. per ubicazione ed orientazione, questo elemento paleotopografico potrebbe corrispondere alla parte alta del fianco esterno dell’edificio vulcanico di via di stabia, laddove esso si sovrappone all’arco della civita. questo elemento morfologico trova riscontro anche nei saggi di scavo condotti nel 2003 dall’equipe coordinata dal dott. florian seiler (istituto archeologico germanico) a porta vesuvio (“i” in fig. 2). qui sia il tracciato di una strada, preliminarmente ascritta al periodo arcaico, che le sovrastanti strutture collegabili all’acquedotto mostrano una pendenza verso nne. la strada suddetta poggia sui prodotti delle ultime eruzioni protostoriche del somma – vesuvio, che coprono, a loro volta, un paleosuolo con pomici dell’eruzione di “ottaviano” (8 ka) (paola petrosino com. pers.) giacente su lave leucitiche scoriacee. il tetto di queste lave si deprime verso s con un dislivello di circa 5.2 m tra la porta vesuvio ed il pozzo di età classica di porta vesuvio (maiuri 1973), cioè su soli 20m di distanza. il dott. seiler fornisce ulteriori dati interessanti a conferma della ricostruzione mostrata in figura 2 indicando l’esistenza di una pendenza verso via di stabia, quindi verso l’asse nw-se della forma craterica, dei livelli presenti sotto le strutture più antiche messe in luce nei saggi realizzati ad w della strada. 55..33 --mmoorrffoollooggiiaa ddii ssuuppeerrffiiccii ssttrraattiiggrraaffiicchhee sseeppoollttee utilizzando i dati stratigrafici ricavabili da affioramenti, saggi archeologici e perforazioni, abbiamo tentato di ricostruire, almeno nelle linee essenziali e per aree con una certa fittezza di informazioni, la morfologia di alcune superfici stratigrafiche sepolte. in particolare ciò è stato effettuato per il tetto del complesso lavico presente nella collina pompeiana e per quello delle lave individuate nel sottosuolo della pianura. aa)) tteettttoo ddeellllee llaavvee ssuullllaa ccoolllliinnaa ppoommppeeiiaannaa sebbene i dati disponibili abbiano consentito di tracciare solo alcune isoipse (con equidistanze di 5 e 10 m), gli andamenti ottenuti confermano l’esistenza della forma arcuata positiva emersa dall’analisi geomorfologica e da noi denominata “arco della civita”. la ricostruzione del tetto delle lave su tale elemento morfo-vulcani110 fig. 6 affioramenti lavici lungo il margine meridionale dell’area archeologica di pompei. lava outcrops along the southern edge of the archaeological site of pompeii. 2comunicazione verbale del dott. felix pirson, responsabile dello scavo per l’istituto archeologico germanico di roma. 3comunicazione verbale del prof. paolo carafa, responsabile dello scavo per l’università “la sapienza” di roma, e della dott.ssa maria teresa d'alessio. a. cinque & g. irollo co è mostrata in figura 7. verso w e nw, poco fuori dell’area mappata, vi sono altre isolate segnalazioni di prodotti interessanti emersi nei sondaggi realizzati nell’alveo penniniello e lungo la linea torre annunziatapompei della ferrovia circumvesuviana, nei tratti di boscotrecase e boscoreale. si tratta di lave vacuolari e scorie grigio-rosate ritrovate a quote abbastanza congruenti con la paleo topografia di figura 7. i sondaggi realizzati a boscoreale indicano lave con tetto a quote comprese tra 30 e 37 m s.l.m. ed in qualche caso la significativa presenza di minerali secondari fumarolici che ne dimostrano la prossimalità. altre segnalazioni si ricavano dai sondaggi realizzati lungo il tracciato autostradale tra torre annunziata e villa dei misteri (di vito et al., 1998a; sondaggi g5, s17, g6 di fig. 1 e 5 dello stesso lavoro). le isolinee di figura 7 delineano anche l’alto isolato di s. abbondio e la depressione di via di stabia; due forme vulcaniche che trovano conferma e migliore definizione con i dati riportati nel paragrafo 5.2. 111 fig. 7 ricostruzione tentativa del tetto delle lave nell’area dei rilievi di pompei (i punti neri indicano l’ubicazione dei sondaggi utilizzati, le cifre a fianco la quota in m s.l.m. del tetto delle lave). tentative reconstruction of the lavas top surface in the area of pompeii hill (black dots indicate the drilling locations plus elevation data (in meters a.s.l.) of lava top). il “vulcano di pompei”: nuovi dati geomorfologici e stratigrafici per mancanza di sondaggi favorevolmente collocati, non è stato possibile supportare l’ipotesi che la fossa di valle rappresenti una depressione craterica (e/o calderica), come suggerisce la sua posizione e la morfologia del suo fianco occidentale. comunque, se si ipotizza un’antica depressione chiusa, il suo bordo orientale (sepolto da successive fasi aggradazionali della piana) va collocato ad occidente del sondaggio “po5” (fig. 1). infatti se tale sondaggio ricadesse nel perimetro della depressione, risulterebbe difficile spiegare la presenza dei sedimenti marini che il suo log indica tra 64 e -67 m, come pure la totale assenza di lave, che invece affiorano lungo il bordo sw della fossa (presso la porta di sarno, fig. 2) ed immergono verso ne. bb)) tteettttoo ddeellllee llaavvee sseeppoollttee nneellllaa ppiiaannuurraa rocce vulcaniche che, per tipologia e per posizione altimetrica e stratigrafica, potrebbero ascriversi all’edificio pompeiano sono state spesso segnalate in sondaggi effettuati nelle circostanti aree di pianura e di piedimonte vesuviano. molte di queste segnalazioni sono anche riportate nella precedente letteratura (ruggiero, 1879; bakunin, 1907; bassani & galdieri, 1908; luongo & rapolla, 1964; di girolamo, 1969; barra et al., 1989; di vito et al., 1997; 1998a; pescatore et al., 1999). e’ interpretabile come una foam lava anche la “roccia bruciata” segnalata da pescatore et al. (1999) in una serie di sondaggi a nw di porta marina (uniti nella sigla “po178” in fig. 1 e 2). il sondaggio “po4” (fig. 2 e 3), realizzato poco a valle della paleofalesia versiliana, mostra lave con cristalli di leucite e pirosseno augitico di grosse dimensioni, immersi in una massa di fondo vetrosa e vacuolare, ricoperte da depositi litorali del complesso versiliano. nel centro della pompei moderna, la stratigrafia del pozzo che alimenta la fonte salutare (bakunin, 1907; bassani & galdieri, 1908), (“po9” in fig. 1-3) indica prodotti lavici, confrontabili con i termini caratterizzanti le vicine aree di pompei scavi e di s. abbondio, a quote comprese tra -3 e -59 m s.l.m. nel settore ad e e se dei rilievi pompeiani, luongo & rapolla, (1964) segnalano lave sepolte in diversi sondaggi (“po1-5-6-7-8-10-12-13” e “sca11-1415-16-17” fig. 1-3-8). nel sondaggio “po6” ed a palestra grande essi individuano due colate vacuolari sovrapposte: una lava a leucite alterata notevolmente friabile, sovrapposta ad una lava leucitica compatta che nel sondaggio “po6” mostra fenocristalli di leucite non alterati ed una maggiore percentuale di fenocristalli di augite. la lava con leucite alterata è individuata anche nel sondaggio “po8” (s. abbondio) dove ha colore grigio scuro, talvolta rossastro ed aspetto molto scoriaceo; quella leucitica compatta è segnalata anche nel sondaggio “po10”. con la sigla “sca11” abbiamo in realtà indicato una serie di sondaggi ravvicinati che incontrano, sotto il livello leucitico scoriaceo, correlabile alla foam lava dell’area archeologica, una lava compatta non leucitica, priva di fenocristalli e di colore grigio scuro, con sanidino, plagioclasio e pirosseno augitico. utilizzando tutti i dati disponibili abbiamo tentato di ricostruire il tetto delle lave (indistinte), il cui esito è mostrato in fig. 8. dato lo scarso numero di dati e la loro ampia spaziatura, abbiamo preferito tracciare solo poche isolinee, corrispondenti ai valori altimetrici che richiedevano minori estrapolazioni. la morfologia ottenuta non evidenzia nessun marcato alto topografico, arcuato e concavo verso w, che possa interpretarsi come complementare dell’arco della civita. tale situazione suggerisce che le lave sepolte nella parte orientale dell’area di studio si siano messe in posto quando l’edificio testimoniato dall’arco della civita era stato già disturbato da faglie e forse in parte sepolto. d’altra parte, alcune articolazioni altimetriche (tra le quali l’alto morfologico isolato segnalato da di maio & sperandeo (1998), suggeriscono la presenza di più centri di emissione e/o di varie colate indipendenti. la generale pendenza verso se fa invece protendere per una origine somma-vesuviana di almeno alcune delle lave. 66 - ddaattii ee ccoonnssiiddeerraazziioonnii ccrroonnoollooggiicchhee per inquadrare cronologicamente le vulcaniti pompeiane, in mancanza di datazioni dirette, si può far ricorso ai rapporti stratigrafici e geomorfologici che le legano ad altri eventi ed elementi geologici di età nota. in tal senso osserviamo innanzitutto che i livelli scoriacei e lavici del cono secondario di s. abbondio (vedi capitolo 3) sono da ritenere più antichi di circa 3,6 ka, in quanto coperti dalle piroclastiti dell’eruzione “di avellino”. d’altra parte il fianco occidentale della collinetta di s. abbondio sembra essere intaccato dalla paleofalesia versiliana, la quale certamente taglia le lave della collina di pompei scavi (tratto tra porta marina e porta di stabia). tali lave sono quindi da considerarsi anteriori ai paleotrac112 fig. 8 quote del tetto delle lave (in m s.l.m.) nei sondaggi del settore orientale e tentativo di ricostruzione della sua morfologia. si ricorda che nel sondaggio po5 non si hanno lave fino a 65m s.l.m. local values (from drillings) and contour lines describing the top surface of the buried lava flow occurring in the eastern sector of the study area (in metres a.s.l.). note that the drilling po5 reached -65 m a.s.l. without passing any lava body. a. cinque & g. irollo ciati costieri cui corrispondono gli antichi cordoni di bottaro-pioppaino e di messigno, rispettivamente attribuiti agli intervalli 3.6÷2.5 ka e 5.6÷4.5 ka (cinque, 1991). le lave emerse nel saggio archeologico di porta vesuvio (paragrafo 5.2) sono coperte da un paleosuolo che contiene le pomici dell’eruzione di ottaviano per cui risultano più antiche di 8 ka. alcune delle colate laviche che affiorano presso il limite meridionale di pompei antica (zona di porta nocera) sembrano avere più di 19 ka visto che rolandi et al. (1997), analizzando un taglio ora scomparso, vi riconobbero al tetto delle pomici che essi attribuiscono alla eruzione “di sarno” le lave che affiorano lungo il margine sw della collina pompeiana e proseguono nel sottosuolo della antistante pianura, non recano mai in sovrapposizione questo marker. secondo di vito et al. (1998a), alcune delle lave sepolte sarebbero databili a circa 18÷20 ka in quanto, nel sondaggio “po3”, un paleosuolo intercalato alle due colate ha fornito una età radiocarbonio pari a 20.3 ± 0.2 ka, mentre un termine analogo, posto alla base della colata più antica, ha dato una età di 18.7 ± 0.28 ka. riteniamo che questi dati numerici vadano considerati con prudenza, e non solo perché contraddicono l’ordine stratigrafico. in primo luogo si deve osservare che i sedimenti posti tra le due colate e sotto la prima di esse (inclusi tra -14 e -24 m s.l.m.) sono di ambiente transizionale, come confermano le faune di tipo salmastro indicate dagli autori in alcuni livelli. se le datazioni riportate fossero esatte, considerando il livello eustatico di 18÷20 ka, bisognerebbe concludere che questo settore di piana abbia subito un successivo sollevamento di oltre 100 m. tale ipotesi contrasta nettamente con la generale tendenza alla subsidenza che domina nell’area durante il tardo quaternario e non trova riscontro in nessun’altra evidenza geologica o geomorfologica. va quindi presa in considerazione l’ipotesi di un sensibile errore nelle datazioni sopra citate; in particolare un invecchiamento da collegarsi forse alla circolazione di acque molto mineralizzate e ricche di co2 vulcanica, ancora oggi abbondante nelle falde idriche della zona (celico et al., 1998). attribuendo, quindi, a tali datazioni il valore di limiti di età massima e considerando che nella bassa piana del sarno la base del pacco sedimentario versiliano si spinge fino a circa -40 m s.l.m. (cinque, 1991), riteniamo molto probabile che i sedimenti transizionali in questione (e le lave pompeiane che vi si intercalano) risalgano ai primi millenni dell’olocene, inserendosi nella parte mediana di quella successione versiliana cui certamente appartengono i depositi immediatamente post-lave nello stesso sondaggio “po3”. dunque, se questa nostra elaborazione è corretta, l’attività del complesso edificio pompeiano si sarebbe protratta sino a pochi millenni or sono. per attribuire un limite di età massima all’intero edificio pompeiano possiamo poi considerare i depositi marini dei sondaggi “po9” e “po5” (fig. 1-3) compresi tra –64 e –83 m s.l.m. i quali indicano un’ingressione che ben difficilmente avrebbe raggiunto quei luoghi se fosse già stato presente l’apparato vulcanico in questione. essi rilevano un’ingressione marina che si addentra circa 25 km oltre il limite della piattaforma continentale (dove sono stati r iconosciuti i cunei di lst del pleistocene medio e superiore; milia & torrente, 1999), per cui vanno quasi certamente legati ad un periodo di marcato high stand. tale periodo va ricercato nel pleistocene ed, in particolare, in epoca anteriore ai 39 ka, in quanto i sedimenti litorali in questione, nel sondaggio “po5” sono sottoposti a una unità tufacea che, per caratteri e posizione altimetrica, sembra essere l’ignimbrite campana. nella piana del sarno, l’ingressione eustatica dell’ois 7 si spinse circa 12 km più all’interno di pompei, raggiungendo il piede dei monti di sarno (spiagge con tetto a -35m s.l.m. nel sondaggio ssml6 di aprile & toccaceli 2002) mentre le paleolinee di riva dell’ultimo interglaciale si spinsero fino a 10 km più all’interno di pompei (depositi di spiaggia e transizionali nel sottosuolo di s. mauro, con tetto a -23m s.l.m.; barra et al., 1991). durante questi ultimi episodi di massimo eustatico, l’area di pompei dovette ricevere sedimentazione pelitica di piattaforma, mentre i sedimenti tra–64 e –83 m nei sondaggi “po9” e “po5” sono delle sabbie e ghiaie litorali che vanno pertanto ascritte a fasi regressive dell’ois 5 o al picco trasgressivo eustatico dell’ois 3.3 (quando, secondo alessio et al. (1994), il mare raggiunge i -18/-20 m s.l.m.). ovviamente i sedimenti in questione sono ribassati dalla ben nota subsidenza quaternaria della piana. volendo ricavare ulteriori vincoli cronologici dai rapporti tra edificio pompeiano ed ignimbrite campana (i. c.), ci si scontra con la difficoltà che essa non è mai segnalata esplicitamente nei log stratigrafici raccolti. tuttavia alcuni di essi segnalano dei tufi grigi e giallastri più o meno litoidi, ovvero degli spessi intervalli di “sabbie piroclastiche” e/o “pozzolane con pomici”, che in prima ipotesi possono interpretarsi come i c. rispettivamente in facies litoide ed in facies sciolta. ma nelle vicinanze della collina pompeiana sono segnalate, con terminologie non dissimili, anche delle piroclastiti che, per quota e gradiente, sono invece da ascriversi alle prime fasi di attività del vulcano locale. 113 fig. 9 ricostruzione della morfologia del tetto dell’ignimbrite campana nel settore orientale e dei prodotti piroclastici pompeiani. (i valori delle isoipse sono in m s.l.m.). tentative reconstruction of the buried top surface of the campanian ignimbrite and other tuffaceous materials belongin to the pompeii volcano. (contour line values are in m a.s.l.). il “vulcano di pompei”: nuovi dati geomorfologici e stratigrafici una ricostruzione del tetto di queste potenti unità piroclastiche è mostrata in figura 9. all’esterno dell’edificio pompeiano la morfologia del tetto della presunta i. c. mostra articolazioni che ben si accordano, per quote e per andamento, con il tetto dell’i. c. ricostruito da aprile & toccaceli, (2002) per la media ed alta piana del sarno. sia in detta figura 9 che nella figura 3 dei citati autori si nota una forma valliva che disseca l’ignimbrite campana e che giunge a quote di circa -30 m nella zona di pompei. la formazione di questa paleovalle è stata certamente favorita anche da bassi livelli glacioeustatici, ma essa si giustifica soprattutto con l’ondata di erosione regressiva innescatasi sul “gradino” creato, sul plateau ignimbritico, dalla faglia nw-se che ribassa l’area del golfo di castellammare di stabia subito dopo (forse anche durante) l’eruzione della i.c. (cinque et al., 1997; milia, 1998; milia & torrente, 1999). il tentativo mostrato in figura 9 purtroppo non consente di comprendere, per mancanza di punti di controllo nelle zone cruciali, se l’edificio tufaceo pompeiano sia cresciuto quando la valle era già incisa o se, predatandola, sia stato da questa dissecato. tuttavia, il fatto che l’edificio dà luogo ad un brusco restringimento della paleovalle tende ad avvalorare maggiormente la prima ipotesi. passando ai dati stratigrafici, sembra che nel sondaggio “po5” le piroclastiti pompeiane poggino sull’i. c. infatti il tufo che qui si riconosce tra –17 e –31 m s.l.m. è correlabile all’i. c. per i suoi caratteri litologici e per la sua posizione altimetrica ben compatibile con la ricostruzione di aprile & toccaceli (2002). ad esso seguono delle “sabbie” anche grossolane (a nostro avviso di natura piroclastica) che plausibilmente rappresentano i primi prodotti del vulcano pompeiano in questa zona. analoghi rapporti di sovrapposizione dei prodotti pompeiani sull’i. c. sembrano riconoscersi, inoltre, nei sondaggi “sca 11-15-17” di figura 3, ubicati all’esterno dell’arco della civita. l’assenza dei depositi ignimbritici nel sondaggio “po9” potrebbe ascriversi a totale elisione durante la sopra citata fase di incisione tardo-pleistocenica (il foro cade infatti nell’asse della paleovalle sepolta). rimane problematica la interpretazione delle pozzolane rossicce, con alternate lave, che si trovano tra –32 e –59 m nel sondaggio “po9”. sebbene litologicamente simili ad alcuni prodotti emessi dalle bocche pompeiane dopo la fase eruttiva a tufi e piroclastiti sciolte, esse si collocano troppo in profondità; persino più in basso della paleovalle prima discussa. potrebbe trattarsi di antichi prodotti del somma o di vulcaniti legate a un centro locale sensibilmente più antico di quelli presi in esame col presente articolo. 88 - ccoonncclluussiioonnii l’esame complessivo dei dati raccolti delinea nell’area di pompei l’esistenza di un complesso vulcanico che trova espressione morfologica nella collina arcuata che da sette termini, presso boscoreale, si allunga fino all’area archeologica della pompei antica (“arco della civita”), nonché nelle culminazioni topografiche minori individuate poco ad e e se di essa. la motivazione geologico-strutturale di questo complesso vulcanico e della sua ubicazione è da riconoscersi, plausibilmente, in un importante lineamento tettonico profondo che è ben evidenziato sulle carte gravimetriche della letteratura (cassano & la torre, 1987): si tratta della faglia ad andamento e-w che va da nocera inferiore (dove definisce un tratto del fronte n dei monti lattari) fino a torre annunziata. essa ribassa il substrato della piana (unità mesozoico-terziarie della catena) di circa mille metri verso n, costituendo uno di principali elementi che definiscono la porzione meridionale del graben della piana campana. l’edificio pompeiano potrebbe collocarsi all’intersezione di tale faglia diretta con un lineamento di direzione appenninica o con una frattura radiale del somma. la ricostruzione dell’andamento nel sottosuolo delle formazioni vulcaniche pompeiane, particolarmente dettagliata nell’area della sezione di figura 4, ha consentito di evidenziare l’esistenza di un complesso basale prevalentemente piroclastico, fagliato ed eroso, che indica un’attività iniziale di tipo sostanzialmente esplosivo. l’attività più recente del complesso vulcanico pompeiano è data invece da emissioni laviche ed attività stromboliana (con prodotti del tipo foam lava). anche se i dati disponibili sono ancora troppo scarsi per chiarire definitivamente la questione, appare verosimile supporre che le lave siano riconducibili a più punti di emissione, alcuni dei quali periferici all’arco della civita (cratere di via stabia; cono di s. abbondio) ed altri ubicati probabilmente su fessure anulari più o meno coassiali col primitivo edificio piroclastico. circa l’età di queste emissioni laviche e scoriacee, il riesame di tutti i dati esistenti ci induce a concludere che esse hanno età variabile da zona a zona e coprono un intervallo di tempo che va da oltre 19 ka (lave presso la porta nocera) fino all’olocene antico. parte di queste emissioni vulcaniche si diressero verso il solco vallivo scavato dal sarno sulla piana dopo che quest’ultima era stata aggradata dalla ignimbrite campana. esse si intercalarono, quindi, ai sedimenti alluvionali, transizionali e costieri che stavano rapidamente colmando la valle durante la fase finale della trasgressione versiliana. con l’apice di questo evento glacio eustatico, il margine meridionale della collina pompeiana venne, infine, modellato da una falesia successivamente disattivata con le fasi di progradazione della piana degli ultimi 5 ka circa. sebbene alcuni dati stratigrafici e paleomorfologici suggeriscano che l’intero edificio pompeiano sia posteriore alla ignimbrite campana, non si può ancora escludere del tutto che quest’ultima predati solo la fase delle emissioni laviche e stromboliane del complesso vulcanico pompeiano, risultando invece più giovane se non coeva all’attività di più spiccato tenore esplosivo. in ogni caso, l’intero edificio pompeiano poggia su sedimenti di pianura costiera e litorali che, sebbene non datati, possono ascriversi ad una trasgressione glacio – eustatica non più antica dell’ ois 5. rriinnggrraazziiaammeennttii si ringrazia il soprintente archeologo di pompei prof. p. g. guzzo per aver autorizzato lo studio delle sezioni emerse nel perimetro dell’area archeologica, per aver consentito di prelevare campioni di lava e per aver 114 a. cinque & g. irollo permesso l’uso delle stratigrafie di sondaggio disponibili in archivio. l’autorità di bacino regionale sarno per aver fornito numerose stratigrafie da sondaggio ed i responsabili delle missioni di scavo archeologico citate nel testo (prof. p. carafa, prof. f. pesando, dott. f. pirson, dott. f. seiler) per aver fornito dati inediti e per le interessanti discussioni. siamo inoltre grati al prof. m. bugno (università degli studi di napoli federico ii) per le indicazioni filologiche relative ai passi degli autori classici citati, al prof. f. senatore per le indicazioni in merito all’area archeologica di pompei ed alla dott. ssa p. petrosino (università degli studi di napoli federico ii) per il prezioso aiuto fornito nell’identificazione delle vulcaniti sia nelle stratigrafie da sondaggio che sui campioni. ringraziamo, infine, il dott. a. sposato e l’altro referee anonimo della rivista per averci fornito preziosi consigli su come migliorare la stesura finale del testo. bbiibblliiooggrraaffiiaa alessio m., allegri l., antonioli f., belluominii g., improta s., manfra l. & preite martinez m. (1994) la curva di risalita del mare tirreno negli ultimi 43 ka ricavata da datazioni su speleotemi sommersi e dati archeologici – mem. descr. carta geol. d’it., lliiii,, 261-276. andronico d., calderonii g., cioni r., sbrana a., sulpizio r. & santacroce r., (1995) geological map of somma-vesuvius volcano period. mineral., 6644 (1-2), 77-78. andronico d., cioni r., marianelli p., santacroce r., sbrana a. & sulpizio r. (1996) – introduction to sommavesuvius – vesuvius decade volcano workshop handbook, september 1177--2222, napoli, 1-13. aprile f. & toccaceli r. m. (2002) nuove conoscenze sulla stratigrafia e distribuzione dei depositi ignimbritici quaternari nel sottosuolo della piana del sarno (salerno-campania)-italia meridionale il quaternario, 1155, (2), 169-174. arnò v., principe c., rosi m., santacroce r., sbrana a. & sheridan m. f. (1987) eruptive history somma-vesuvius, cnr quad. ric. sci., (r. santacroce editor), roma, 53-103. aavv, (1994) neapolis planimetria della città antica di pompei -, (a cura della soprintendenza archeologica di pompei, in collaborazione con consorzio neapolis), roma. bakunin m. (1907) la sorgente di valle di pompei – mem. acc. pont., xxiiii, anno xxxvii, 1-6. barbieri m., di girolamo p., locardi e., lombardi g. & stanzione g. (1979) – petrology of the calc – alkaline volcanics of the parete 2 well (campania, italy). period. di mineral., 4488, 53-74. barra d., bonaduce g., brancaccio l., cinque a., ortolani f., pagliuca s. & russo f. (1989) evoluzione geologica olocenica della piana costiera del fiume sarno (campania) mem. soc. geol. it., 4422, 255-267. barra d. (1991) studio del pleistocene superiore-olocene delle aree vulcaniche campane – tesi di dottorato università degli studi di napoli “federico ii”. barra d., cinque a., gewelt m. & hurtgen c. (1991) l’ospite caldo silvestra seminis (bonaduce, masoli e pugliese, 1976) (crustacea, ostracoda): un possibile marker dell’ultimo interglaciale dell’area mediterranea il quaternario, 44 (2), 327-332. barra d., romano p., santo a., campajola l., roca v. & tuniz c. (1996) the versilian transgression in the volturno river plain: palaeoenvironmental history and chronological data il quaternario, 1100 (2), 571-578. bassani f. & galdieri p.(1908) la sorgente minerale di valle di pompei: relazione geologica atti acc. sci. fis. mat., xxiivv serie seconda (2), 1-8. bellucci f. (1998) nuove conoscenze stratigrafiche sui depositi effusivi ed esplosivi nel sottosuolo dell’area del somma-vesuvio – boll. soc. geol. it., 111177, 1-21. bernasconi a., bruni p., gorla l., principe c. & sbrana a. (1981) risultati preliminari dell’esplorazione profonda nell’area vulcanica del somma – vesuvio – rend. soc. geol. it., 44, 237-240. bertagnini a., landi p., rosi m. & vigliargio a. (1996) – the pomici di base plinian eruption (19,000 yr b.p.). – vesuvius decade volcano workshop handbook, napoli september 17-22, 1-12. brancaccio l., cinque a., romano p., rosskopf c., russo f., santangelo n. & santo a. (1991) geomorphology and neotectonic evolution of a sector of the tyrrenian flank of the southern appennines (region of naples, italy), z. geomorph. n. f., suppl. bd. b2, 47-58. brocchini d., principe c., castradori d., laurenzi m. a. & gorla l. (2001) quaternary evolution of southern sector of the campanian plain and early somma-vesuvius activity: insights from trecase 1 well – mineral. petrol., 7733, 67-91. carta geologica d’italia foglio 185 – salerno1969. cassano e. & la torre p. (1987) geophisic sommavesuvius cnr quad. ric. sci. (r. santacroce editor) roma, 175-196. celico p., stanzione d., esposito l., ghiara m. r., piscopo v., caliro s. & la gioia p. (1998) caratterizzazione idrogeologica ed idrogeochimica dell’area vesuviana – boll. soc. geol. it., 111177,, 3-20. cinque a. & russo f. (1986) la linea di costa del 79 d.c. fra oplonti e stabiae nel quadro dell’evoluzione olocenica della piana del sarno (campania) – boll. soc. geol. it., 110055, 111-121. cinque a. (1991) la trasgressione versiliana nella piana del sarno (campania) – geogr. fis. dinam. quat., 1144, 63-71. cinque a., aucelli p. p. c., brancaccio l., mele r., milia a., robustelli g., romano p., russo f., russo m., santangelo n. & sgambati d. (1997) volcanism, tectonics and recent geomorphological change in the bay of napoli – geogr. fis. dinam. quat. suppl.., iiiiii (t 2) 123-141. civetta l., orsi g., pappalardo l., fischer r. v., heiken g. & ort m. (1997) geochemical zoning, mingling, eruptive dynamics and depositional process – the campanian ignimbrite, campi flegrei caldera, italy – j. volcanol. geotherm. res. 7755, 183-219. d’ambrosio a., mastroroberto m., stefani g., rota l., melluso l., morra e., santangelo n., di maio g., sperandeo g.& deino a. (2001) – assetto geoarcheologico dell’area pompeiana: nuovi dati per un’ipotesi di ricostruzione paleoambientale – pompei scienza e società (a cura di guzzo p. g.), 115il “vulcano di pompei”: nuovi dati geomorfologici e stratigrafici electa, milano, 207. de vivo b, rolandi g, gans p. b., calvert a., bohorson w. a., spera f. j. & h. e. (2001) new constraints on the pyroclastic eruptive history of the campanian volcanic plain (italy) – mineral. petrol., 7733 (1-3), 47-65. di girolamo p. (1963) la serie piroclastica dell’eruzione di pompei, studio chimico–petrografico, mineralogico e stratigrafico dell’eruzione del 79 d.c. e dei prodotti ottavianitici del somma-vesuvio – ann. oss. ves., vv, (serie vi), 1-69. di girolamo p. (1968) un esempio di lava schiuma (foam lava) in campania. (lava schiuma di pompei scavi) – rend. acc. sci. fis. mat. napoli, xxxxxxvv, 3-12. di girolamo p. (1969) lave orvietitiche da trivellazioni nella zona del somma–vesuvio – rend. soc. it. mineral. petrol., xxxxvv, 317-345. di maio g. & sperandeo g. (1998) geoarcheologia dell'area di pompei. dati preliminari le scienze della terra e l'archeometria (a cura di d'amico c. & a. livadie c.), cuen, napoli, 223-226. di vito m. a., sulpizio r., zanchetta g. & sbrana a. (1997) ricostruzione della geologia del sottosuolo dell’area densamente urbanizzata tra s. giorgio a cremano e pompei (napoli) geologia delle grandi aree urbane, progetto strategico cnr, atti del convegno, bologna. di vito m. a., sulpizio r., zanchetta g. & calderoni g. (1998a) the geology of the south western slope of somma-vesuvius, italy, as inferred by borehole stratigraphies and cores acta vulcanologica, 1100 (2), 383-393. di vito m. a., bella g., sulpizio r. & zanchetta g. (1998b) stratigrafia dei depositi quaternari nel settore sud-orientale della piana campana”, xiv convegno scientif ico annuale del gruppo nazionale per la vulcanologia, catania. geosond soc. coop. a r.l. (1989) indagini geotecniche per la sistemazione del canale conte di sarno. ippolito f. (1938) segnalazione di un pozzo esistente nell’antica città di pompei – boll. soc. natur. napoli xxlliixx, (xv), 3-8. ippolito f. (1962) sulla stratigrafia del somma– vesuvio saggi e studi di geologiamem. note ist. geol. appl. napoli, vviiiiii, 62-318. ippolito f., ortolani f. & russo m. (1973) struttura marginale tirrenica dell’appennino campano: reinterpretazione di dati di antiche ricerche di idrocarburi – mem. soc. geol. it., 2222, .227-250. luongo g. & rapolla a. (1964) su alcune colate laviche precedenti l’eruzione del 79 d.c. – ann. oss. ves., vvii (serie vi) 3-21. maiuri a. (1960) – pompei – sterro dei cumuli e isolamento della cinta muraleboll. arte min. pubb. istr., ii--iiii, 166-179. maiuri a. (1973) – alla ricerca di pompei preromana – soc. ed. napoletana, 15-19. mastroroberto m. la necropoli di s. abbondio: una comunità dell ’età del bronzo a pompei archeologia e vulcanologia in campania, (a cura di guzzo p. g. & peroni r.) napoli, 135-149. milia a. (1998) – le unità piroclastiche tardo-quaternarie nel golfo di napoli – geogr. fis. dinam. quat., 2211, 147-153. milia a. & torrente m. m. (1999) tectonics and stratigraphic architecture of a peri-tyrrhenian half-graben (bay of naples, italy) – thectonophysics, 331155, 301-318. nicotera p. (1950) sulle rocce laviche adoperate nell'antica pompei pompeiana raccolta di studi per il secondo centenario degli scavi di pompei, napoli, 396-424. orsi g., de vita s. & di vito m. (1996) the restless, resurgent campi flegrei nested caldera (italy): constraints on its evolution and configuration – j. volcanol. geotherm. res., 7744, 179-214. ortolani f. & aprile f. (1978) – nuovi dati sulla struttura profonda della piana campana a sud est del fiume volturno boll. soc. geol. it., 9977, 591-608. patti o. (2003) – nuovi dati per la ricerca geo-archeologica dell’insula dei casti amanti (ix, 12) – rivista di studi pompeiani xxiivv,, 320-328. pescatore t., senatore m. r., capretto g., lerro g. & patricelli g. (1999) ricostruzione paleoambientale delle aree circostanti l’antica città di pompei (campania, italia) al tempo dell’eruzione del vesuvio del 79d. c. – boll. soc. geol. it., 111188, 243-254. plinius – naturalis historia – c. mayhoff leipzig, 18751906. rolandi g., maraffi s., petrosino p. & lirer l. (1993) – the ottaviano eruption of somma-vesuvio (8000 y b. p.): a magmatic alternating fall and flow-forming eruption – j. volcanol. geotherm. res., 5588, 43-65. rolandi g., belluccii f. & petrosino p. (1997) the volcanic roots of pompeii and herculaneum volcanism and archaeology in meditarranean area, 89-100. rolandi g., bertolini f., cozzolino g., esposito n. & sannino d. (2000) sull’origine delle coltri piroclastiche presenti sul versante occidentale del pizzo d’alvano (sarno-campania) – quaderni di geologia. applicata, 77 (1), 37-47. rolandi g., bellucci f., heizler m. t. & belkin h. e. (2003) – tectonic controls on the genesis of ignimbrites from the campanian volcanic zone, southern italy – mineral petrol., 7799, 3-31. romano p., santo a. & voltaggio m. (1994) l’evoluzione geomorfologica della pianura del fiume volturno (campania) durante il tardo quaternario (pleistocene medio-superiore – olocene) – il quaternario, 77 (1), 41-56. rosi m. & sbrana a a. (a cura di) (1987) the phlegrean fields. cnr quad. ric. sci.roma, 111144 (9). ruggiero m. (1879) della eruzione del vesuvio nell’anno lxxix, godot, napoli, 5-6. scandone r., bellucci f., lirer l. & rolandi g.(1991) the structure of the campanian plain and the activity of the neapolitan volcanoes (italy) – j. volcanol. geotherm. res. 4488, 1-31. vitruvius – de architectura – f. krohn, lipsiae 1912. 116 ms. ricevuto il 28 ottobre 2003 testo definitivo ricevuto il 6 aprile 2004 ms. received: october 28, 2003 final text received: april 6, 2004 a. cinque & g. irollo microsoft word 00_indice_bm03 available online http:/amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 25 (1), 2012, 57-66 paleohydrographic evolution and its influence on human settlement in the karthaliny basin (georgia) stefano furlani1,2, giovanni monegato3, alberto stinghen4,1, elena rova5, david kuparadze6, giovanni boschian7, matteo massironi1 & aldino bondesan1 1 dipartimento di geoscienze, università degli studi di padova, italy 2 dipartimento di matematica e geoscienze, università degli studi di trieste, italy 3 istituto di geoscienze e georisorse, consiglio nazionale delle ricerche, torino, italy 4 museo tridentino di scienze naturali, trento, italy 5 dipartimento di studi umanistici, università ca’ foscari, venezia, italy 6 caucasian institute of mineral resources, tbilisi, georgia 7 dipartimento di biologia, università di pisa, italy corresponding author: s. furlani <sfurlani73@gmail.com> abstract: two bronze age human settlements of the western karthaliny basin (transcaucasia region, georgia) were studied using a multidisciplinary approach. satellite data (corona, landsat) and aerial images, as well as new archaeological data and a detailed field survey were applied to the study of the hydrographic evolution of the kura (mtkvari) river and of its tributaries; its influence on the archaeological sites scattered between the villages of natsargora and agara was also examined. finally, four stratigraphic profiles were analysed; these are situated along the kura river and on its tributaries flowing from the greater caucasus: the western and the eastern prone. geoarchaeological analyses were carried out in the bronze age settlements: the first one -natsargorais situated on the top of a mound facing a valley, in an area of low hills, and it lies upon the neogene bedrock. the position of the site indicates that the drainage system was already in a phase of deepening during the early bronze age. the second one is located on a terrace of the kura river and corresponds to the mound of aradetis orgora. the reconstruction of the palaeosurfaces and palaeochannels, and a radiocarbon date from the base of this site, allowed to outline the changes in fluvial style and drainage network. keywords: geoarchaeology, geomorphology, late holocene, kura river, georgia. 1. introduction in regions where early human settlements are well preserved, researchers studying the holocene evolution of the landscape can take advantage of archaeological data, which represent specific markers, as well as useful chronological tools. usually, human settlements are closely related to the availability of water. in this perspective, river terraces were valuable locations, close to the river water, and also protected from natural hazards, like river floods. they represented ideal positions also from a strategic point of view, dominating the surroundings areas and improving the protection of the sites from enemies. human traces related to fluvial sediments or morphologies are the key to date alluvial events; they become crucial where river dynamics have changed the landscape through time. this paper aims at outlining the palaeohydrographic evolution of the kura river (mtkvari in georgian) and the related tributaries upstream of gori, to the west of this town; the area lies between the archaeological sites of natsargora and aradetis orgora, whose study explained the evolution of the drainage pattern. 2. study area the karthaliny basin is located in the shida kartli region of central georgia. it consists of very wide basins and valleys confined between the great caucasus to the north and the lesser caucasus to the south (fig. 1). from a geological point of view, the basin belongs to the system of transcaucasian (sensu khain, 1975) sedimentary basins related to the alpine orogenesis. the area is enclosed between two mountain ridges with opposite vergence, i.e. the north-verging lesser caucasus and the south-verging greater caucasus (koçyiğit et al., 2001). the continental collision is still evolving, and it is testified by the high seismicity of the region (adamia et al., 1977; gamkrelidze, 1986; triep et al., 1995; reilinger et al., 2006; tan and taymaz, 2006). the karthaliny basin is 1.200 km2 wide and its geometry is complicated by the internal ridge of the kvernaqi range. the area to the north of the ridge is dominated by alluvial deposition originating from the greater caucasus, while the southern one consists of the middle valley of the kura river. the kura river is 1520 km long, with its upper catchment in eastern turkey; then it crosses the whole georgian territory from west to east, and flows into the caspian sea in azerbaijan. the present level of the caspian sea is about 26 m below mean sea level, and it shows larger and furlani s. et al. 58 faster fluctuations compared to global sea level fluctuations (karpitchev, 1993). the caspian sea is independent from the eustatic sea level of the world’s oceans, thus creating an independent base level. the basin is characterised by foreland basin sedimentary sequences of the greater caucasus, with a thickness of 2 km for the middle miocene – quaternary time span (ershov et al., 2003). the sequence starts with deposits ascribed to shallow-marine facies and shifts towards quaternary continental deposits; these are mostly alluvial and are related to the kura river system and -to the northto rivers flowing from the greater caucasus, i.e. the prone and the liakhvi river (gudjabidze, 2003). these quaternary alluvial deposits mainly consist of sand, with subordinate gravel and clay. the latter is very important from an archaeological perspective, since it was exploited as raw material for bricks and pottery. the petrographic characteristics of the sediments indicate that the alluvial deposits originated from the mountain area of the lesser caucasus: the lithotypes coming from tertiary magmatic rocks are abundant, together with gabbros deriving from the permian magmatic series located westwards of the study area (gudjabidze, 2003). chert fragments originate from carbonate units located in the southern as well as in the northern zones of the basin. the tertiary sedimentary fill of the karthaliny basin is characterised by marls and chalky clays, with interbeddings of quartzitic and micaceous sandstones. the climate of georgia was divided into nine classes, as suggested by davitaia (1970). specifically, the climate of the shida kartli region is partially wet, with cold winters and long, warm summers. maximum temperatures can reach 40°c in summer, while minimum temperatures, usually in january, can reach 16°c, but are usually around -5°c. soil temperatures show similar variations. annual rainfall is around 450500 mm, with minima in winter (with 40-50 days of snow), and maxima in summer, with aspects of subtropical climate. solar radiation is peculiarly intense in summer, since the days are mostly clear and with scarce cloud cover. 3. materials and methods this study was carried out following a multidisciplinary approach, with focus on published data and on new findings. it includes remote sensing and aerial photo analysis, archaeological survey in the area of two archaeological sites (natsargora and aradetis orgora), and geological survey that was carried out during two research missions (2010, 2011). at natsargora, archaeological excavations uncovered the anthropogenic features of the site and the thickness of the quaternary sedimentary sequence. at aradetis orgora, which is located on the scarp of a river terrace, the sedimentary sequence and the lowest levels of the archaeological fig. 1 sketched geological map of the karthaliny basin (modified after gudjabidze, 2003). the karthaliny basin is located in the black frame in the geographical map of georgia, while the study area is framed in black. paleohydrographic evolution and its influence on human settlement in … 59 sequence were observed on outcrops along the river bank. remote sensing analysis was carried out on corona and aster images, upon which the position and the geometry of the major rivers and palaeochannels were reconstructed. the main morphometric features and hydrological elements of the studied area were traced on a digital terrain model (dtm), produced using srtm (shuttle radar topography mission) data with 90 m/pixel resolution (farr et al., 2007). fieldwork on the sedimentary cover was carried out contemporary to the archaeological survey, and several stratigraphic logs were sketched. a wood fragment from aradetis orgora was dated in the radiocarbon dating laboratory of the weizmann institute of science (israel). 4. data field survey data and aerial photo analysis are reported in the following paragraphs. fieldwork was focused on the study of the two bronze age archaeological sites, i.e. the natsargora (fig. 2) and aradetis orgora mounds (fig. 3). an analysis of the relief in the study area and the related hydrographic network have been provided. moreover, the stratigraphic sections of three outcropping profiles were described. 4.1. relief analysis and hydrographic network the southeastern sector of the study area is crossed by the kura river (fig. 4), whose alluvial plain lies at an average altitude of about 630 m a.s.l., gently sloping towards southeast. to the north, the plain is limited by an alluvial terrace extended throughout the study area, from the eastern to the western side (fig. 4, 5c, d); its average elevation is about 650 m a.s.l., and it slopes gently southwards (fig. 6). it is also incised by the western and eastern prone, which are two left-side tributaries of the kura (fig. 1, 4). conversely, the northwestern sector is characterised by a hilly morphology shaped in miocene sedimentary units. these hills are the southernmost fringe of the dzirula massif, and consist of low, rounded ridges, ranging from 600 to 900 m; these are interrupted by small valleys developed along the e-w direction. this relief is characterised by slopes with average gradients lower than 15° (fig. 5a, b); the summits are elongated in a sse/nnw direction and follow the main tectonic structures of the area, fold axes and faults, whose strike is sse/nnw. the southernmost relief is connected to the alluvial terrace through a surface that was interpreted as an erosional glacis (fig. 5b). 4.2. stratigraphic sections in the study area 4.2.1 section 1. stratigraphic section along the eastern prone wgs 84 coordinates: 43°53'11,46"e 42°3'56,083"n, elevation: 670 m a.s.l. (fig. 7a). this 10 m high per 10 m wide section crops out on the slope of the eastern prone left bank, northeast of aradetis orgora. a 5 m-thick gravel body lies upon an erosional surface shaping the tertiary sandstone bedrock. it is made up of roughly bedded, clast-supported and cemented sandy gravels; the clasts are rounded and comprise volcanic and sedimentary rocks. the top of this sedimentary body is an erosional surface, overlain by a 2 m-thick coarse gravel deposit. the pebbles are rounded, with an average size coarser than in the underlying body, and mainly made up of tertiary volcanic rocks, suggesting a lesser caucasus provenance. the scarce matrix is sandy and the structure is clast-supported, with evident imbrications. this deposit is overlain by a 3 m-thick silty unit with gravel lenses occurring in the lower part, while the upper one is a massive reddish brown silt, on which a soil is developed. this includes an a horizon overlying a bk petrocalcic horizon. 4.2.2 section 2. stratigraphic section along the western prone wgs 84 coordinates: 43°47'23,528"e 42°3'58, 119"n, elevation: 650 m a.s.l. this 3 m-high section crops out on the slope of the western prone right bank, northwest of aradetis orgora, (fig. 7b). a 0.50 m-thick layer of cemented gravel lies upon an erosional surface that cuts the bedrock, which is made up of tertiary sandstone. these roughly bedded gravels are clast-supported, with rounded clasts made up of sedimentary rocks. the top of this unit is marked by an erosional surface overlain by 2 m of roughly bedded sandy gravel with rounded pebbles, made up of volcanic and sedimentary rocks, and abundant sandy matrix with matrix-supported structure. the section ends fig. 2 the archaeological site of natsargora. a) view from the southern side. early bronze age remains on the top of the site; b) view of the natsargora mound toward south. furlani s. et al. 60 up with about 0.5 m of massive silt, largely covered by vegetation. 4.2.3 section 3. stratigraphic section along the western prone, left side wgs coordinates: 43°46'27,47"e 42°2'35,663"n, elevation: 650 m a.s.l. this 10 m-thick section (fig. 7c) is located 2 km upstream of aradetis orgora, along the slope of the left bank of the western prone river. the bottom unit is a 6 m-thick plainly bedded sandy gravel layer with small cross-bedded lenses; the structure is clast-supported. the pebbles are rounded, with an average size of 50 mm, and made up of sedimentary and volcanic rocks. an erosional surface shapes the top of this unit, and is overlain by an about 4 mthick coarse gravel body with clastsupported structure; the pebbles are rounded, with an average size of 10-30 mm, and mainly made up of volcanic rocks; the sandy matrix is abundant. 4.3 archaeological data 4.3.1 natsargora the natsargora archaeological site (fig. 2a, b) is located in the khashuri district, at the western border of the shida kartli province, close to the homonymous village (bertoldi et al., in press), at the confluence of the natsargorisghele and pleula (fig. 4) streams. the site was excavated, between 1984 and 1992, by the georgian archaeologist alexander ramishvili, and is presently investigated by a joint georgianitalian archaeological expedition (rova et al., 2010; puturidze & rova, in press). in the surroundings of the site, the relief is shaped into rather soft miocene molasses, and is characterised by smooth hills and valleys mostly developed along the e-w direction. some small outcrops of sandstone and/or marl dipping towards the north can be observed in the surroundings of the site, mostly in spots affected by strong erosion. unfortunately, the topography of the whole area has been strongly reshaped in recent times for agricultural purposes: surfaces were smoothed mechanically, ditches were excavated, wide land extensions were reafforested and then cleared again; therefore, it is now somewhat difficult to reconstruct the features of the original landand soilscape. at present, the area is mostly used for cattle grazing and crop growing, with sparse open wood areas and some scattered scrubby vegetation; the eastern side of the archaeological site is partly covered by scrubs and few trees. the archaeological site lies on the top of a small hill protruding from the side of the gently dipping ridge shaped by the two streams. this hill is about 50 m wide and 90 m long, with its major axis oriented nw-se and fig. 3 the archaeological site of aradetis orgora. a) stratigraphic sequence of the aradetis orgora mound; b) view of the settlement of aradetis orgora built above the natural mound (terrace of the kura). paleohydrographic evolution and its influence on human settlement in … 61 steep sides (up to 40°); the top is flat and almost horizontal, or very slightly dipping towards the se, with a maximum height of 778 m a.s.l. the height of the top above the ridge side is about 10 m on the northern side of the hill, and 25 m on the southern one, because of the dip of the ridge itself. summing up, the hill resembles a smooth cone with a flat top. it must be pointed out that the shape of the hill was modified in the 1980s, during the archaeological excavations carried out by a. ramishvili, who removed part of the original anthropogenic deposit from the top of the hill and dumped debris along its sides: it is likely that some narrow terraces occurring around the top resulted from these activities. the original total thickness of the anthropic accumulation can be estimated to about 3 m, considering that the a. ramishvili’s excavations removed about 2.5 m of sediment from the northern part of the site, and about 0.5 m from the southern one. therefore, the maximum height of the hill was probably around 780.50 m a.s.l. before the beginning of the georgian excavation. at present, the archaeological deposit is rather thin or even absent to the northwest of the hilltop, while it is at least 2.5 m thick to the southeast; this implies that the erosion surface that shapes the marly/sandy bedrock dips towards the south more strongly than the presentday surface, although its precise shape is still unknown, since the southern part of the site has not yet been excavated deeply enough. the natural surface of the mound may have been modified by humans during the first phases of the site use, and future excavations will be aimed to better highlight this aspect. the archaeological deposit includes an early bronze age level, overlain by a thick late bronze/early iron one; traces of classical antiquity frequentation are testified by sparse potsherds. the sediments on the top of the hill are generally silty to loamy, with variable clay percentage and sparse stones; these may originate from the dismantling of complex anthropogenic features, like buildings or pebble pavements, that were also observed in various areas of the excavation. cultural remains, like pottery, chipped stone, animal bones, and charcoal are extremely common. the early bronze age units were uncovered in small areas during the recent archaeological excavations, and their characteristics are still to be fully understood. apparently, the main features are prepared floors made up of compacted yellowish silt, alternating with dark levels made up of poorly sorted fine material, rich in charcoal and generic domestic waste. some other features are also present; these are shallow depressions (0.1 to 0.2 m deep) of roughly rectangular shape, 1.0-1.5 m wide, that are filled up with burned soil and daub, ash and some charcoal. in addition, poor remains of small circular huts were also unearthed. unfortunately, these deposits were intensely reworked and disrupted ab antiquo by the late bronze age people, who excavated a very large number of subcylindrical pits, 0.5 to 1.5 m wide and up to 1 m deep; these often cut other previously refilled pits, so that the underlying sediments were almost completely destroyed throughout wide areas, where only few remains of the older features are preserved. this process has been particularly strong in the nw area of the excavation, where the archaeological deposit is also shallow; as a consequence, the early bronze age levels are largely reworked here. conversely, these levels are probably better preserved in the southern area of the settlement, where some test trenches suggest the presence of thicker deposits. the late bronze age horizons are also characterised by prepared floors alternating with domestic refuse, similar to the early bronze ones; the pits are filled up by more or less homogeneous greyish silty loam, embedding mostly domestic refuse, like sparse stones, daub fragments, pottery sherds, animal bones, charcoal, etc. almost all traces of the post-settlement history were removed from the top of the hill during the ramishvili’s excavations. colluvia occur all around the sides of the hill; they partly look rather fresh and made up of loose and fluffy sediments, so that it cannot be excluded that they are in fact recent (and more recently colluviated?) waste dumps of the previous excavations. 4.3.2 aradetis orgora the aradetis orgora archaeological site hosts a settlement of roman/medieval age, which was ex fig. 4 geological and geomorphological sketch of the study area. furlani s. et al. 62 cavated by georgian archaeologists under the direction of prof. iulon gagoshidze (fürtwängler et al., 2008). it is situated on the right side of the kura river, on its terrace, a few hundred metres to the west of the confluence of the eastern and western prone rivers into the kura, west of the village of doghlauri. the terrace escarpment faces sw and is oriented nw-se; it cuts abruptly the site with a straight and very steep scarp, the foot of which dips almost directly into the prone; this terrace is dissected by two secondary erosion features, i.e. two small valleys. one of these is a deep channel with steep sides, which runs east to west before flowing into the prone; the other one is dry and oriented n-s, its sides are less steep, and it is wider and shorter than the former. the upper parts of these erosion features are connected, so that a sort of continuous channel separates a roughly conical hill with a flat top from the main terrace (fig. 3, 8). the hilltop is 650 m a.s.l. high, and lies about 25 m above the level of the prone river. the stratigraphic observations were carried out on an exposed profile on the southern side of the terrace scarp, where the archaeological levels are superimposed to the alluvial deposits of the kura river and its tributaries (furlani et al., 2011). the sequence exposed on the terrace scarp includes the following units, from bottom to top: 1. finely bedded coarse sandstone/fine gravel with crossed bedding. thickness at least 3 m (the bottom was not observed). 2. well bedded and strongly cemented coarse polygenic conglomerate, with frequently imbricated rounded elements in sandy matrix. thickness 7÷8 m. 3. medium to coarse polygenic conglomerate, somewhat chaotic, well cemented; finer levels (made up of well bedded fine gravel to sand, up to 0.5÷6 m thick, are common. thickness 4÷5 m. 4. light yellowish sandy silt loam, homogeneous and without sedimentary features. thickness about 1.5÷2 m. 5.light greyish to brownish silt loam, with welldeveloped coarse granular structure; the limit with the underlying level is diffuse. poorly developed soil (entisol), probably truncated at the top. thickness ranges between 0.2÷0.4 m. 6. poorly cemented unsorted conglomerate in abundant silty loam matrix; the elements are angular to rounded, randomly scattered throughout the thickness of the unit. thickness about 4 m. the unit is largely covered by recent colluvia, debris, and excavation dump, so that it is not easy to observe its characteristics throughout the thickness; apparently, the cultural remains that occur sparserly on the slope are probably reworked, and fig. 5 views of the studied area: a) view of the valley of the pleula river in eastern direction. the valley is covered by 3 m of alluvial deposits and the river flows on the teritary bedrock. it merges with the western prone at berzenauli; b) view of the glacis, the river terrace and the present-day alluvial deposits of the kura river from sajvare. in the distance the lesser caucasus; c) the terrace slope at khidiskuri; d) view of the terrace slope from samtsevrisi in northern direction. paleohydrographic evolution and its influence on human settlement in … 63 should be ascribed to the overlying archaeological deposit. a handaxe found in the same levels, some hundred metres from the site on the main terrace, may suggest a middle pleistocene age (i. gagoshidze, personal communication, 2011). 7. thick sequence including a very large number of complexly interbedded lithologic units with highly variable characteristics, most of which are anthropogenic. debris deriving from the collapse of walls and other archaeological features, pits filled up with unsorted domestic waste, etc. are common. the lowermost part is made up of finer sediments, mostly silty loam. thickness up to 4÷5 m. within this last horizon, the classical antiquity archaeological levels overlay a long sequence of earlier levels, which date back at least to the late 4th millennium bc and constitute a large archaeological site that is still largely unexplored. starting from the base, three main archaeological levels have been identified (fig. 3): 1) an early bronze age level characterised by a sequence of layers with abundant pottery and ceramics fragments of the kura-araxes and bedeni periods (late 4th-mid 3rd millennium bc) in a muddy matrix. radiocarbon dating of a wood fragment from the base of the sequence yielded an age of 4375±40 14c bp (50504850 cal bp, 3100-2900 cal bc, 2, sample rtk-6134, rehovot laboratory). this level is buried under a 1.5 mthick coarse gravel body which apparently does not include cultural remains; though it may resemble fluvial gravel, its shape and position suggest that it is most probably anthropogenic. it must be pointed out that this body is exposed on a relatively small area, and that further observations should be carried out in order to infer its origin with reasonable confidence. 2) a late bronze age level characterised by muddy matrix with abundant pottery fragments; a roman age and later level in the topmost part of the sequence, characterised by abundant pottery and brick fragments. 5. discussion the studied human settlements are apparently located preferentially on terrace edges or on isolated high spots of the landscape. even if the shape of the sites may often resemble the typical “tell” of the near east and levant, their mound-like shape is in fact for the most part natural, and not the result of continuous rebuilding over previous features and products of their decay. regarding the natsargora site, the original shape of the mound could be related to river erosion processes (e.g., leopold et al., 1995; mills & mills, 2001). in many cases, roughly conical hills were chosen for settling, and only their uppermost part is anthropogenic, as at natsargora and aradetis orgora, and probably at other nearby sites. it is not unlikely that these hills were partly reshaped in order to fit the needs of the settlers, most probably by flattening their top; at natsargora, the relative depth of the bedrock to the northwestern and southeastern ends of the area may suggest that the bedrock was also shaped in wide steps. conversely, it is much more difficult to show if also the sides of these hills were artificially shaped in order to improve their defensive power, as suggested by i. gagoshidze (personal communication, 2011) with reference to the ravine that separates the northern side of aradetis orgora from the adjacent terrace and by a. ramishvili, in his unpublished excavation report, with reference to the depression which separated the natsargora mound from the adjacent ridge. unfortunately, these two sites were more or less extensively excavated in the last decades, so that no information about the late history of the sites -i.e. after their abandonment is available. the anthropogenic shaping of the mound top at aradetis orgora could be inferred by an accurate comparison of the elevation of the tops of the terrace and of the alluvial sediment lying below the archaeological sequence of the mound. nonetheless, it must be observed that the limit between natural and anthropic sediments on the mound is largely covered by anthropogenic features and excavation waste dumps; good quality measurements will hopefully be carried out during future excavations. on the contrary, any intentional reshaping of the sides of the mounds cannot be distinguished from natural erosional processes. assuming that the deposits at the base of the terrace sequence are river sediments deposited by the kura, field analyses indicate that the floodplain of the kura river was much wider in the past, and it reached the hills to the north (kvernaqi range) and the toe of the glacis, south of natsargora. the terrace is 30 m above the present thalweg of the kura, and to its northern edge it is covered by alluvial fans and colluvia deposited by the prone. the kura conglomerates occurring in the lower 15 m of the sequence suggest that the floodplain fig. 6 north-south topographic profile between natsargora and the kura. the profile highlights the presence of relieves at about 650 m a.s.l., a wide erosive glacis, the quaternary terrace and the present-day alluvial course. furlani s. et al. 64 was first interested by strong braided channel stream development; conversely, the upper 3 m-thick silty-sand body points to overbank episodes; this facies change can be ascribed to the evolution of the fluvial system from braided to an increase of sinuosity, with the formation of meanders. these river processes filled up a large part of the valley up to a level of about 18 m above the present-day valley bottom. after the deposition of the silty levels, the depositional processes stopped for a probably short time, allowing the formation of an entisol. later on, alluvial fans started developing from the north to the south, because of the eastern prone activity; the soil and the underlying sediments were covered by about 4-5 m of rather chaotic coarse gravel, and the kura river bed was pushed to the south (left side of the course) by the developing fan (or fans). in this case, the biface found on the terrace surface should be considered just as a terminus post quem, as it may have been transported by the prone from elsewhere in its basin. in a final phase, the kura changed its aggradational trend into deepening, and the formation of the terrace and of the intrenched meander started. the western and eastern prone were flowing 30 m above the present level, and followed the kura base level starting the incision of the terrace edge just at the beginning of is formation. regarding the deepening processes of this phase, it can be observed that the bottom of the trough encircling the northern side of the aradetis orgora site is suspended above the present-day kura floodplain, and that the two short valleys that compose it end towards the kura with evident steps. therefore, it can be inferred that this shape is in fact an abandoned meander, intrenched in the sediments lying below the surface of the terrace. part of these processes may be related to late pleistocene climate changes, but the intense seismicity characterising the area (philip et al., 1989; triep et al., 1995) suggests also some tectonic contribution to the uplift of the area. in this perspective, the early development of the prone rivers alluvial fans, as well as of the glacis, could have been triggered by the uplift of the kvernaqi range. the development of the wide kura floodplain may be ascribed to an increase of river flow connected to the end of the last ice age (18-15 ka), while the incision of the drainage network would have been triggered by the uplift of the kvernaqi range coupled to erosion processes connected with the late pleistocene early holocene climate instability. later on, according to connor and sagona (2007), the period between 6 and 4 ka bp (roughly corresponding to the expansion of the “kura-araxes” communities) was characterised by a climatic improvement, with high rainfall and mild temperatures; this environmental situation would have favoured the development of the wood cover and a general stabilisation of the hillslopes, but it must also be considered that the kura-araxes groups may have contrasted this process starting deforestation processes because of strong wood exploitation for metal processing. in this perspective, if the intrenched meander developed before -or even duringthe prehistoric frequentation, then the gravel layer covering the early bronze age levels (fig. 3, 8) found atop the aradetis orgora hill (cfr. supra, point 1 of the archaeological sequence) cannot be other than anthropogenic. subsequently, the deepening of the kura riverbed and its southward migration, coupled with the energy increase of the local fig. 7 localities of stratigraphic interest in the studied area. section 1) stratigraphic sequence of an alluvial terrace along the eastern prone river. section 2) a: the western prone flow on the bedrock which is composed by tertiary sandstones; b) the river cuts a thin alluvial deposit; section 3) a) view of the slope terrace along the southernmost sector of the western prone, near the site of aradetis orgora; b) detail of the alluvial deposits of the alluvial terrace. paleohydrographic evolution and its influence on human settlement in … 65 streams due to deforestation may have reshaped the intrenched meander changing it into the two small incisions surrounding the site. conversely, if the shape was not identified as an intrenched meander, a late development of the incisions would not be in accordance with the generalised behaviour of the copper-bronze age groups, who apparently preferred naturally isolated hilltops for settling. 6. conclusions fluvial systems react to natural agents like tectonics, climate or sea-level changes (e.g., schumm, 1977; jones et al., 1999) as well as to human modifications, such as agricultural, mining and urban activities. on the other hand, humans and their settlements react to, and adapt themselves to natural environment. in this perspective, the transcaucasian region represents a good case study to assess the relative importance and the overlapping of these factors; here, the interaction of natural and anthropogenic modifications started at least in the middle holocene, when the spread of production economies triggered strong human interference on the environment. detailed archaeological investigations at natsargora and the analysis of the exposed section of aradetis orgora were integrated with identification and analysis of the geomorphological and sedimentary features of the karthaliny basin. the result of this work are a reconstruction of landscape evolution and an outline of the interactions between human settlements and palaeohydrographic setting of the area, since the early bronze age. this research was mainly based on a multidisciplinary fieldwork approach, involving archaeologists, geomorphologists and geologists, and merging together different disciplines to reconstruct a complex landscape evolution. data from satellite images, new and published archaeological data and a detailed field survey allowed to better outline the hydrographic evolution of the kura river and its influence on the archaeological sites, which are distributed between the natsargora and agara villages. geoarchaeological analysis was carried out in two archaeological sites: the first one, at natsargora, was built on the top of a small relief separated from the terrace. the second one, which corresponds to the mound of aradetis orgora, is located on an intrenched abandoned meander of the kura river. in both cases, relatively strong intentional modification of the topography was apparently carried out by the settlers, in order to adapt the areas to the settlement needs. the position of the sites suggests that the drainage system, dominated by the kura river base level, was already in a phase of deepening during the bronze age in the whole karthaliny basin, as also suggested by the incised pattern of the two prones. these data, along with the reconstruction of the palaeosurfaces and palaeochannels, and together with a radiocarbon date from the base of the aradetis orgora site, point to rapid changes in fluvial styles and drainage network, and to fast erosion processes during the late pleistocene and early holocene. acknowledgements we are kindly grateful to prof. iulon gagoshidze and dr. mindia jalabadze (georgian national museum), who accompanied us on the aradetis orgora site during the 2009 and respectively 2011 seasons. moreover we acknowledge giulia de nobili and giorgi khaburzania for field assistance. the field survey in the natsargora and aradetis orgora areas took place in the framework of the “georgian-italian shida kartli archaeological project” of ca’ foscari university of venice in collaboration with the georgian national museum, jointly directed by elena rova, zurab makharadze and marina puturidze. this was funded by ca’ foscari university, ministero degli affari esteri, and the shelby white-leon levy program for archaeological publications. moreover, we acknowledge sara biolchi of the university of trieste for editing the geological and geomorphological map. we are also grateful to luca bertoldi for data collected during the first year of survey and to elisabetta boaretto for carrying out 14c analysis on the aradetis orgora sample. the manuscript received a great improve from the revisions by f. carraro and an anonymous reviewer. references adamia sh.a., lordkipanidze m.b., zakariadze g.s. (1977) evolution of an active continental margin as exemplified by the alpine history of the caucasus. tectonophysics, 40, 183-199. bertoldi l., stinghen a., bondesan a., furlani s., massironi m., monegato g. (in press) geology and geomorphology of the natsargora archaeological site. in m. puturidze & e. rova (eds.), khashuri natsargora: the early bronze age graves (publications of the georgian-italian shida kartli archaeological project i) (subartu 30), turnhout: brepols publishers, 3-5. connor s., sagona a. (2007) environment and society in the late prehistory of southern georgia, caucasus. in: b. lyonnet (éd.), les cultures du caucase (vie-iiie millénaires avant notre ère): leurs relations avec le proche-orient. paris. cnrs editions / editions recherche sur les civilisations. 21-36. davitaia f. (1970) landscape map of georgia. tbilisi, metsnierebe. fig. 8 profile of the terrace and the archaeological settlement of aradetis orgora. furlani s. et al. 66 ershov a.v., brunet m.f., nikishin a.m., bolotov s.n., nazarevich b.p., korotaev m.v. (2003) northern caucasus basin: thermal history and synthesis of subsidence models. sedimentary geology, 15, 95-118. farr t.g., rosen p.a., caro e., crippen r., duren r., hensley s., kobrick m., paller m., rodriguez e., roth l., seal d., shaffer s., shimanda j., umland j., werner m., oskin m., burbank d., alsdorf d. (2007) the shuttle radar topography mission. rev. geophys., 45, rg2004, 33 pp, doi: 10.1029/2005rg000183. furlani s., stinghen a., bertoldi l., boaretto e., bondesan a., kuparadze d., massironi m., monegato g., rova e. (2011) integrating archeological and geomorphological data to evaluate the lateholocene behavior of the kartalini basin (georgia). il quaternario – italian journal of quaternary science, special number, 24, 186-188. fürtwängler a., gagoshidze i., lohr h., ludwig n. (2008) iberia and rome. the excavations of the palace at dedoplis gora and the roman influence in the caucasian kingdom of iberia. langenweissbach 2008. gamkrelidze i.p. (1986) geodynamic evolution of the caucasus and adjacent areas in alpine time. tectonophysics, 127, 261-277. gobejishvili r. (2004) late pleistocene (wurmian) glaciation of the caucasus. in j. ehlers & p.l. gibbard (ed.) quaternary glaciations – extent and chronology, amsterdam, 129-134. gudjabidze g.e. (2003) geological map of georgia, 1:500.000. georgian state department of geology and national oil company “saqnavtobi”. jones s., frostick l.e., astin t.h. (1999) climatic and tectonic controls on fluvial incision and aggradation in the spanish pyrenees. journal of the geological society of london, 156, 761-769. karpytchev y.a. (1993) reconstruction of caspian sea-level fluctuations: radiocarbon dating coastal and bottom deposits. radiocarbon, 35, 409-420. khain v.y. (1975) structure and main stages in the tectonomagmatic development of the caucasus: an attempt at geodynamic interpretation. american journal of science, 275(a), 131-156. koçyiğit a., yılmaz a., adamia s., kuloshvili s. (2001) neotectonics of east anatolia plateau (turkey) and lesser caucasus: implication for transition from thrusting to strike-slip faulting. geodinamica acta, 14, 177-195. leopold l.b., wolman m.g., miller j.p. (1995) fluvial processes in geomorphology. dover publications, 522 pp. mills h.h., mills r.t. (2001) evolution of undercut slopes on abandoned incised meanders in the eastern highland rim of tennessee, usa. geomorphology, 38, 317-336 philip h., cisternas a., gvishiani a., gorshkov a. (1989) the caucasus: an actual example of the initial stages of continental collision. tectonophysics, 161, 1-21. puturidze m., rova e. (in press) khashuri natsargora: the early bronze age graves (publications of the georgian-italian shida kartli archaeological project i) (subartu 30). turnhout: brepols publishers. reilinger r., mcclusky s., vernant p., lawrence s., ergintav s., cakmak r., ozener h., kadirov f., guliev i., stepanyan r., nadariya m., hahubia g., mahmoud s., sakr k., arrajehi a., paradissis d., al-aydrus a., prilepin m., guseva t., evren e., dmitrotsa a., filikov s. v., gomez f., al-ghazzi r., karam g. (2006) gps constraints on continental deformation in the africa-arabia-eurasia continental collision zone and implications for the dynamics of plate interactions. journal of geophysical research, 111(b05411), doi: 10.1029/ 2005jb004051. rova e., puturidze m., makharadze z. (2010) the georgian-italian shida kartli archaeological project: a report on the first two field seasons 2009 and 2010. rivista di archeologia, 34, 5-30. schumm s.a. (1977) the fluvial system. wiley, new yoerk, 338 pp. tan o., taymaz t. (2006) active tectonics of the caucasus: earthquake source mechanisms and rupture histories obtained from inversion of teleseismic body waveforms. in y. dilek & s. pavlides (eds.) postcollisional tectonics and magmatism of the mediterranean region and asia. geological society of america special paper, 531-578. triep e.g., abers g.a., lerner-lam a.l., mishatkin v., zakharchenko n., starovoit o. (1995) active thrust front of the greater caucasus: the april 29, 1991, racha earthquake sequence and its tectonic implications. journal of geophysical research, 100(b3), p. 4011-4033, doi: 10.1029/94jb 02597. ms. received: january 23, 2012 final text received: march 8, 2012 impaginato di donato eeffffeeccttss ooff llaattee pplleeiissttoocceennee--hhoolloocceennee cclliimmaattiicc cchhaannggeess oonn tthhee ppllaannkkttoonniicc ffoorraammiinniiffeerraa iinn tthhee gguullff ooff ggaaeettaa ((ttyyrrrrhheenniiaann sseeaa,, iittaallyy)) vvaalleennttiinnoo ddii ddoonnaattoo dipartimento di scienze della terra università degli studi di napoli “federico ii” tel. 081 5473338 e-mail: valedido@unina.it abstract planktonic foraminiferal assemblages of core g93-c9, recovered in the gulf of gaeta (tyrrhenian sea) at 212 m of depth, were analysed by principal components analysis. the analysis was computed first on raw percentage data and then on logratio transformed data. the most important difference between raw data and logratio data rests in the behaviour of n. pachyderma which in the first case, unlike the second, does not have significant loading on the first component. sea surface temperatures exerted a strong control on foraminiferal assemblages. hydrography and productive system also played an important role in determining composition of assemblages, as shown by the loadings of grazing species on the second component. during the last deglaciation and the early holocene eutrophic conditions allowed globorotalia inflata to expand its distribution toward surface waters of the gulf of gaeta. during the late holocene, planktonic foraminiferal assemblages evidence a tendency towards oligotrophic conditions. riassunto effetti dei cambiamenti climatici tardo pleistocenici-olocenici sui foraminiferi planctonici del golfo di gaeta (mar tirreno, italia). vengono presentati i risultati di una analisi dei componenti principali applicata alle associazioni a foraminiferi planctonici della carota g93-c9, prelevata nel golfo di gaeta a 212 m di profondità. l’analisi è stata effettuata prima sui dati originali e successivamente applicando ad essi una trasformazione logratio per correggere l’effetto della chiusura dei dati percentuali. i risultati ottenuti differiscono principalmente nel carico di neogloboquadrina pachyderma sul primo componente, che risulta quasi nullo con i dati originali e significativo con i dati trasformati. le temperature delle acque superficiali hanno svolto un controllo primario sulle variazioni delle associazioni, in cui si riconoscono chiaramente due gruppi di specie con carichi opposti sul primo componente. i punteggi del primo componente lungo la carota definiscono chiaramente i principali eventi climatici avvenuti durante l’ultima deglaciazione. i carichi sul secondo componente di specie prevalentemente erbivore evidenziano l’effetto di fattori trofici ed idrografici. in particolare tra tardiglaciale e olocene inferiore si instaurano condizioni eutrofiche che consentono a globorotalia inflata, una specie prevalentemente mesopelagica, di proliferare anche in prossimità della costa. viceversa nel corso dell’olocene superiore i risultati evidenziano l’istaurarsi di condizioni oligotrofiche. keywords: planktonic foraminifera, climatic changes, late pleistocene-holocene, tyrrhenian sea, principal components analysis. parole chiave: foraminiferi planctonici, cambiamenti climatici, pleistocene superiore-olocene, mar tirreno, analisi dei componenti principali. il quaternario italian journal of quaternary sciences 1155(2), 2002, 251-257 11.. iinnttrroodduuccttiioonn in the last few decades many studies involving the analysis of foraminiferal assemblages have been carried out on late-pleistocene-holocene sediments in the mediterranean sea, allowing detailed reconstruction of the environmental changes occurred during the last climatic cycles (blanc-vernet et sgarrella, 1989; kallel et al.1997, ariztegui et al. 2000, among others). relatively few studies, however, focus on neritic or coastal environments. an opportunity to study the effect of climatic changes in a neritic milieu was offered by an oceanographic cruise of the o/v urania, in october 1993, during which several cores were collected from the gulf of gaeta continental shelf. the general results of an integrated palaeontological study on three cores (g93c5, g93-c8, g93-c9) involving descriptive analysis of planktonic foraminifera, calcareous nannofossils, pollen and ostracoda, were reported by amore et al. (2000). a detailed analysis of calcareous nannofossil assemblages, involving comparisons with other sectors of the southern tyrrhenian continental shelf, was carried out by esposito (1999). due to its continuous stratigraphical record and good quality of fossil assemblages, core g93-c9 offers the opportunity to examine planktonic foraminiferal assemblages in detail. with a view to examining the responses of foraminiferal assemblages to environmental changes, planktonic foraminifera of core g93-c9 are investigated by principal component analysis (pca). 252 v. di donato 22.. mmaatteerriiaallss aanndd mmeetthhooddss the study area is located within the gulf of gaeta continental shelf, in the southern tyrrhenian sea (fig. 1). the area represents an extension of the volturno river and garigliano river coastal plains. gravity core g93-c9 (lat.41°02’ 4” n, long. 13°32’18”e), 470 cm long, was collected at a depth of 212 m, along an esewsw seismic line. the stratigraphy of core g93-c9, whose sediments consist mainly of clays, is summarised in figure 2. for palaeontological analyses of core g93c9, 47 samples spaced 10 cm apart were collected. samples were washed through a 106 µm sieve. from each sample at least 300 specimens of planktonic foraminifera were collected by using complete splits. the choice of the sieve mesh, which may appear somewhat unusual, requires some explanation. in classical works on oceanic planktonic foraminiferal assemblages large sieve meshes were adopted (i.e. 149 µm) (imbrie & kipp, 1971; among others), obtaining very low percentages of undeterminable specimens. this method, however, also artificially reduces the percentages of small species. at the opposite end, in recent works on mediterranean planktonic foraminiferal assemblages (capotondi, 1999; among others) very small sieve meshes (65 µm) were adopted, obtaining higher (and less biased) abundances of small species. assemblages resulting from treatment with a small sieve mesh, however, contain high percentages of undeterminable specimens and, consequently, a lower number of actual specimens. at the same time the number of censored values (i.e. values below the detection limit) for less abundant larger species distinctly increases, with a negative effect on the accuracy of data (sanford et al., 1993). to avoid such shortcomings it would be necessary to increase the number of specimens counted per sample. by adopting an intermediate sieve mesh (i.e. 106 µm) fewer censored values result, together with only slightly reduced percentages of small species. in order to investigate the relationship among planktonic foraminiferal species, in the present paper assemblages are investigated by means of a pca. the pca was first computed on the raw data and then by applying a logratio transformation (aitchison, 1986; kucera and malmgren, 1998) to the original variables for closure correction. with regards to the foraminiferal species included in the analysis, globoturborotalita tenella and globoturborotalita rubescens were lumped together, while no distinctions were made about neogloboquadrina pachyderma, since it was almost entirely represented by right coiled specimens. no rotations were applied to the components. since in the original data the three most abundant species (turborotalita quinqueloba, globigerina bulloides and globigerinoides ruber) constitute more than the 64% of total assemblages, it was preferred to operate on the correlation matrix rather than the variance-covariance matrix, in order to investigate relationships between less abundant species. the results obtained with logratio transformed data are less affected by the choice of the matrix to be factored. the interpretation of assemblages is based on the present distribution of species (bé & torlderlund, 1971; hembleben et al.1983; pujol and vergnaud grazzini, 1995; among others). the analyses were performed with systat. figure. 1 location map. ubicazione della carota g93-c9. depths in radiocarbon calendar core c9 age source ages ages references (cm) (kyr) (kyr bp) 55 ecozones 2-1 2.8 2.5 capotondi boundary et al. (1999) 75 ecozones 3-2 4.0 3.9 capotondi boundary et al. (1999) 125 ecozones 6-5 10.0 10.9 capotondi boundary et al. (1999) 165 ecozones 7-6 11.4 12.9 capotondi boundary et al. (1999) 170 14c ams dating 12.030±0.100 13.45 (intercept) tab. 1. age sources for core g93-c9. ams c14 dating were calibrated with calib 4.3 (stuiver and reimer, 1994). riferimenti per l’inquadramento cronologico della carota g93c9. la calibrazione delle età radiocarbonio è stata effettuata con calib 4.3 (stuiver and reimer, 1994). 33.. cchhrroonnoossttrraa--ttiiggrraapphhiiccaall ffrraammeewwoorrkk only one ams 14c dating obtained from radiocarbon measurement of globigerinoides spp., globigerina bulloides and orbulina shells, was available for core g93-c9. in order to improve the age model, some events recorded in planktonic foraminifera assemblages were tentatively correlated with the ecozone boundaries of capotondi et al. (1999). the age model is shown in table 1. the climatostratigraphy reconstructed for core g93-c9 by palaeontological proxies (amore et al., 2000) is reported in figure 2. the last glacial period (lg) is represented from the base of the core up to 205 cm. the deglaciation, in which events corresponding with the bølling-allerød and the younger dryas were identified, was recorded in the 205-125 cm interval. the upper part of the core represents the holocene. 44.. rreessuullttss percentages of planktonic foraminifera recorded in core g93-c9 are shown in table 2. tables 3a and 3b show the loadings for the components corresponding to eigenvalues greater than 1, computed respectively from the correlation matrix of the raw and the log transformed data. the most important difference between raw data and logratio data rests in the behaviour of n. pachyderma which in the first case, unlike the second, does not have significant loading on the first component. a minor 253effects of late pleistocene holocene ... 2 6,93 19,1 41,9 7,59 0,33 1,32 0 4,29 0 2,97 8,91 0 1,32 5,28 10 4 21 47,3 5,67 0 2,33 0 1,33 0 5 8,33 0 1 4 20 1,97 24 33,2 6,25 1,64 0,33 0 13,8 0 1,97 4,61 0,66 1,97 9,54 30 8,12 27,9 35,4 6,82 0 3,25 0,65 1,95 0 2,6 1,95 1,95 2,92 6,49 40 4,26 12,8 33,4 5,9 0 0,66 0 10,8 0 5,57 5,25 1,31 5,57 14,4 50 27,2 10,6 27,2 4,32 3,65 8,31 0 6,31 0 2,33 1,99 2,33 1 4,65 60 9,24 19,8 34,3 6,6 0,33 2,31 0 1,32 0 4,95 2,97 12,2 1,32 4,62 70 12,6 27,2 27,5 6,62 0,99 3,31 1,66 0,99 0,33 1,99 2,65 6,62 1,32 6,29 80 5,94 13,2 30,4 11,6 12,9 2,31 1,32 3,63 0 4,62 0,66 1,65 2,64 9,24 90 13,4 21,2 22,7 14 14,3 2,49 0,62 1,56 0 2,8 0 0,93 1,25 4,67 100 9,78 19,9 26,8 18 8,2 0,95 0 2,21 0,95 2,52 0 1,58 0,63 8,52 110 17,4 17,1 22,9 11,3 5,12 4,1 3,41 2,39 2,39 0,68 1,02 1,02 0,34 10,9 120 10 20,7 35 12,3 5 1,33 1 1 0 1 3 0,33 0 9,33 130 26,2 43,7 6,47 9,39 6,47 1,29 0,32 0,65 0,32 0,32 0,32 0 0,32 4,21 140 19,3 19,6 23,5 11,8 8,5 3,59 1,96 0 0 0,33 0 0,98 0,33 10,1 150 27,4 18,2 18,5 7,96 3,18 5,73 8,28 1,27 1,59 0,96 0 0,32 0 6,69 160 24,5 21,2 15,4 13,7 5,23 1,96 3,59 2,61 0,33 0,33 0,65 0 0,65 9,8 170 32,7 14,7 18,7 15 6,67 2,67 0 2,67 0 2 0,33 0,33 0,33 4 180 16,8 22,7 25,3 12,8 1,32 2,63 1,32 1,64 0 2,3 0 0,99 0,33 11,8 190 15,4 19,7 33,1 13,1 0,66 0,98 2,95 0,98 1,31 3,28 0,33 0,66 0,66 6,89 200 20,7 17,7 23 11,7 8,33 1,67 1,33 2,33 0 0,67 0 0 0 12,7 210 28,9 28 9,21 6,58 10,5 5,59 1,32 3,62 1,32 0,66 0,66 0 0 3,62 220 30,8 17,5 8,9 2,05 3,42 9,93 4,45 6,85 5,48 0,68 0 0 0 9,93 230 32 27,5 12 2,27 1,29 5,5 5,5 0 2,59 0 0 0,97 0 10,4 240 33,1 20,4 15,3 5,73 10,5 2,55 2,55 0,96 0,64 0 0 0,32 0 7,96 250 46,5 32,9 1,99 2,99 7,31 1,33 2,33 0,33 1,66 0 0,33 0 0 2,33 260 38,4 22,9 4,52 1,94 1,61 7,42 4,84 4,19 3,87 0,32 0,32 0 0 9,68 270 37,3 26,9 3,57 1,3 5,84 5,84 6,82 0,32 2,27 0 0 0 0 9,74 280 48,4 22,5 3,27 3,59 4,9 0,65 1,96 1,31 0 0 0,33 0 0 13,1 290 42,3 28 6 2,33 4,67 3,33 4,33 0 3,33 0,33 0,33 0 0 5 300 46,4 18,8 0 2,96 1,97 7,89 2,96 1,97 4,93 0 0 0 0 12,2 310 36,2 32,1 2,52 2,83 1,57 6,29 7,23 0,94 1,57 0,31 0 0 0 8,49 320 39,4 38,1 1,28 3,21 7,37 1,92 2,24 0 0,96 0 0 0 0 5,45 330 54 27 1,67 1,67 5,67 4,33 0,33 0,33 2,33 0 0 0 0 2,67 340 31 44,8 5,36 1,53 1,15 5,75 0,77 1,92 2,3 0 0 0 0 5,36 350 34,4 34,1 1,3 1,3 5,19 7,79 6,17 0,97 1,3 0 0 0,32 0 7,14 360 42,7 42,7 1,95 0,65 1,95 2,28 0,98 0 1,3 0 0 0 0 5,54 370 31,9 37,2 7,89 2,84 7,57 5,36 1,26 1,26 0,32 0 0,95 0,63 0 2,84 380 51,5 24,1 0,98 0 1,95 3,58 2,61 0,65 2,28 0 0,33 0 0 12,1 390 34,6 35,9 5,08 0,95 4,44 3,81 7,94 1,59 0,95 0 0 0 0 4,76 400 50,8 31,8 0,66 0,98 5,57 1,31 0,98 0 1,64 0 0 0 0 6,23 410 42,5 31,9 2,66 1,66 6,98 2,66 2,33 1 2,99 0 0 0 0 5,32 420 19,4 37 1,42 2,84 7,11 3,79 1,9 1,42 3,32 0 0 0,47 0 21,3 430 36,5 24,3 2,63 1,64 3,29 15,5 6,25 0,66 3,62 0 0 0,33 0 5,26 440 36,9 39,5 2,33 1,99 7,97 2,66 1,33 0 2,99 0 0 0 0 4,32 450 37,3 38 0,95 2,22 6,65 6,01 0,95 0 3,16 0 0 0 0 4,75 460 31,1 26,2 1,97 5,9 7,54 6,89 0,66 1,31 5,25 0 0 0,66 0,66 11,8 470 47 22,8 0,99 0 2,98 10,6 3,97 1,32 3,97 0 0,33 0 0 5,96 table 2. percentages of planktonic foraminifera within core g93-c9. percentuali dei foraminiferi planctonici della carota g93-c9. cm t ur bo ro ta lit a qu in qu el ob a g lo bi ge rin a bu llo id es g lo bi ge rin oi de s ru be r g lo bo ro ta lia in fla ta n eo gl ob oq ua dr in a pa ch yd er m a g lo bi ge rin ita g lu tin at a n eo gl ob oq ua dr in a du te rt re i g lo bo tu rb or ot al ita g lo bo ro ta lia s ci tu la o rb ul in a un iv er sa g lo bo ro ta lia tr un ca tu lin oi de s g lo bi ge rin oi de s sa cc ul ife r g lo bi ge rin el la s ip ho ni fe ra in de te rm in ab le difference regards the third component obtained with the logratio transformations, which corresponds to the fourth component of the original data. in figure 2 the scores of the first three components computed from the logratio transformed data are plotted along core g93c9. the following discussion is based on the results achieved with the logratio transformation. 55.. ddiissccuussssiioonn the first three components, corresponding to eigenvalues greater than 1, take into account respectively 55.48%, 10.64% and 8.26% of total variance. the cumulative variance retained is 74.38% of the total variance. as shown in table 3b, the first component clearly individualizes two groups of species, the first of which, characterised by high positive loadings, is constituted by warm water species. the second group consists mainly of cold water species, with high negative loadings. this structure suggests a relation between this component and sea surface temperatures (sst). it can be also observed that in core g93-c9 globigerina bulloides and globigerinita glutinata are grouped with cold water species, while globorotalia inflata is grouped with warm species, as a consequence of its absence during the lg. the comparison of first component scores with algebraic climatic curves for pollen and calcareous nannofossils (figure 3), points out a good agreement in the general trends, supporting the interpretation of the first component in terms of changes in sst. the scores of the first component are lower in the interval corresponding to the lg. the following trend in pc scores points out changes in sst corresponding to the bøll ing-allerød and 254 younger dryas events of the last deglaciation. the holocene is characterised by increasing values of first component scores. the second component is characterised by high loadings of grazing species, negative for n. pachyderma and g. inflata and positive for globorotalia truncatulinoides (table 3b). the abundance of n. pachyderma, which is usually considered a polar-subpolar species, has been related in the mediterranean sea to the development of eutrophic conditions and a deep chlorophyll maximum (dcm) (rohling and gieskies, 1989; rohling, 1994). the present distribution within the mediterranean sea of g. inflata appears to be related to a rather cool and deep mixing as well as high primary production levels (pujol and vergnaud grazzini, 1995). moreover although g. inflata is mainly a mesopelagic species, it reaches high abundances in shallow water when phytoplankton blooms occur in the mixed layer (pujol and vergnaud grazzini, 1995). in the fossil record this species reaches high abundances during glacial-interglacial transitions (blanc-vernet et al., 1984). as regards g. truncatulinoides, pujol & vergnaud grazzini (1995) suggest that vertical mixing and winter convection are the primary factors controlling the distribution of this species within the mediterranean. in the gulf of salerno g. truncatulinoides, although its percentages never exceed 13%, it is the only grazing species whose abundance increases during the last 5000 yr, when fossil assemblages evidence a decrease in palaeoproductivity (buccheri et al., 2002). on the basis of the above mentioned remarks, the second component may be likely related to trophic conditions and convection in the water column. in practice the highest negative scores reached during the last deglaciationearly holocene interval (fig. 2) could indicate the establishment of eutrophic conditions in the gulf of gaeta. on the contrary positive scores characterise the late holocene, suggesting a decrease in palaeoproductivity. besides the “open water” system of the modern tyrrhenian sea has oligotrophic characteristics (margalef et al. 1966). the opposite relationship between g. inflata and g. truncatulinoides may appear unexpected, as these species are often associated within the mediterranean sea (pujol & vergnaud grazzini, 1995). the positive loading of g. truncatulinoides does not imply an oligotrophic connotation for this species which does not reach high percentages in the late holocene. rather it evidences that during the early holocene environmental conditions were unfavourable for this species. as regards g. inflata, its abundance during the last deglaciation has also been recorded in the shallow core c5 recovered in the gulf of gaeta at a depth of 111 m bsl (amore et al. 2000). this means that during the last deglaciation, when the sea level was about 80-90 m lower than at present (fairbanks, 1989), this species was also abundant in shallower water in the gulf of gaeta. this behaviour probably derived, in addition to advantageous conditions (such as the presence of transitional water masses), also from enhanv. di donato ced primary productivity levels related to increased continental run-off. this is also supported by the high percentages of braarudosphaera bigelowii, a calcareous nannofossil species related to turbidity of surface water and/or low salinity (müller, 1979), recorded within the same interval (esposito, 1999; amore et al., 2000). the composite effect on sea surface temperature changes and trophic regime is highlighted in a plot of core samples on the space defined by first and second components (fig. 4). the plot allows two groups of samples to be distinguished, the first of which comprises samples from the lg and the deglaciation, with an upward trend towards negative scores for the second component. the second group is represented by late holocene samples, with positive scores for both components. the third component is characterised by high positive loadings of globigerinoides sacculifer and negative loadings of globoturborotalita and does not have a clear interpretation. the results of the standardized pca seem to simply highlight the single peak of g. sacculifer within core g93-c9. at present, this tropical species is uncommon within the mediterranean sea, apart from the gulf of lion where this species is very abundant at the pc1 pc2 pc3 pc4 turborotalita quinqueloba -0,883 0,015 -0,105 0,062 globorotalia scitula -0,686 0,416 0,192 0,077 globigerina bulloides -0,563 -0,190 -0,671 0,017 neogloboquadrina dutertrei -0,544 0,336 0,362 -0,219 globigerinita glutinata -0,517 0,571 0,404 -0,131 neogloboquadrina pachyderma -0,180 -0,742 0,351 0,205 globigerinoides sacculifer 0,456 0,121 -0,127 -0,724 globoturborotalita spp. 0,543 0,421 0,142 0,554 globorotalia inflata 0,631 -0,521 0,434 -0,087 globorotalia truncatulinoides 0,723 0,347 -0,317 0,146 globigerinella siphonifera 0,779 0,238 -0,053 0,203 orbulina universa 0,909 0,133 0,029 -0,118 globigerinoides ruber 0,944 0,025 0,087 -0,111 eigenvalues 5,909 1,857 1,252 1,044 percent of total variance explained 45,452 14,288 9,633 8,032 table 3a component loadings, eigenvalues and percent of total variance for pca computed from raw data. component loadings, autovalori e percentuale della varianza totale per l’analisi dei componenti principali relativa ai dati percentuali pc1 pc2 pc3 turborotalita quinqueloba -0,913 -0,025 0,045 globorotalia scitula -0,867 0,210 0,014 neogloboquadrina dutertrei -0,799 -0,041 -0,066 globigerinita glutinata -0,735 0,279 0,061 globigerina bulloides -0,692 0,076 0,265 neogloboquadrina pachyderma -0,620 -0,584 -0,163 globoturborotalita spp. 0,493 0,351 -0,686 globigerinoides sacculifer 0,538 -0,069 0,638 globorotalia inflata 0,596 -0,678 -0,114 globorotalia truncatulinoides 0,643 0,488 0,025 globigerinella siphonifera 0,806 0,183 0,271 globigerinoides ruber 0,829 -0,228 -0,042 orbulina universa 0,904 0,020 -0,011 eigenvalues 7,083 1,383 1,074 percent of total variance explained 54,481 10,638 8,259 table 3bcomponent loadings, eigenvalues and percent of total variance for pca computed from logratio transformed data. component loadings, autovalori e percentuale della varianza totale per l’analisi dei componenti principali dei dati sottoposti a una trasformazione logratio. 255 end of summer (pujol and vergnaud-grazzini, 1995). according to bé and tolderlund (1971) this species is more abundant in sea surface waters with intermediate salinities, while the maximum abundance of g. ruber occurs at more extreme salinities, as in the present-day mediterranean sea. the highest abundances of g. sacculifer and consequently highest positive scores of the third component in core g93-c9 are reached around 3.5 kyr. this peak, which has been recognised throughout the western mediterranean (capotondi et al. 1999) coincides, in the gulf of salerno, with the re-entry of styliola subula, a halophile pteropod. buccheri et al. (2002) relate this event to the increase in sea surface salinity following the end of the sapropel s1 stagnation phase. the present distribution of g. sacculifer suggests that its abundance peak could be related to an enhanced influx of atlantic waters after the end of the s1 stagnation phase, with sea surface salinities higher compared with the stagnation phase, but lower in comparison to the present. 66.. ccoonncclluussiioonnss the results of a pca of planktonic foraminiferal assemblages of gulf of gaeta, applied first to the raw percentages data and then to the logratio transformed data, differ primarily in the behaviour of n. pachyderma, which has no significant loading on the component related to sst if the pca is computed from the raw data. this result is analogous to that obtained by blancvernet and sgarrella (1989) in tyrrhenian and adriatic sea cores. however if data are corrected for closure the same species achieves a negative loading on the same component. apart from the strong influence exerted by changes in sst, hydrography and trophic regime also play an important role in determining composition of assemblages. in particular second component scores indicate the establishment of eutrophic conditions during the last deglaciation and the early holocene which allowed g. inflata to expand its distribution toward shallow waters of the gulf of gaeta. by contrast the late holocene is characterised by a tendency towards the establishment of oligotrophic conditions. aacckknnoowwlleeddggeemmeennttss i wish to thank prof. giuliano ciampo and dr. paola esposito for their reviews of the work and their constant support. thanks are also due to an anonymous reviewer for his critical and constructive comments. effects of late pleistocene holocene ... figure 2 stratigraphy of core g93-c9 and scores of the first two component of foraminiferal assemblages. carota g93-c9. stratigrafia, climatostratigrafia e punteggi dei primi due componenti principali delle associazioni a foraminiferi planctonici. 256 v. di donato figure 4 plot of core samples on the space defined by first and second components. numbers refer to depth in core g93-c9. grafico dei campioni della carota g93-c9 nello spazio definito dai primi due componenti. figure 3 first component scores of planktonic foraminiferal assemblages compared with algebraic climatic curves for pollen and calcareous nannofossils (from amore at al. 2000). raffronto tra i punteggi del primo componente delle associazioni a foraminiferi planctonici e le curve climatiche algebriche di pollini e nannofossili calcarei. first component s ec on d co m po ne nt rreeffeerreenncceess aitchison, j., 1986. the statistical analysis of compositional data. chapman & hall, new york, 416 pp. aritzegui, d., asioli, a., lowe, j.j., trincardi, f., vigliotti, l., tamburini, f., chondrogianni, c., accorsi, c.a., bandini mazzanti, m., mercuri, a.m., van der kaars, s., mckenzie, j.a. and oldfield, f., 2000. paleoclimate and the formation of sapropel s1: inferences from late quaternary lacustrine and marine sequences in the central mediterranean region. palaeogeogr. palaeoclimatol. palaeocol. 158, 215-240. amore, f.o., ciampo, g., di donato v., esposito, p., russo ermolli, e. and staiti, d., 2000. an integrated micropalaeontological approach applied to late pleistocene-holocene palaeoclimatic and palaeoenvironmental change (gaeta bay, tyrrhenian sea). in: hart, m.b. (editor), climates: past and present. geological society, london, special publications, 118811: 95-111. bé a.w.h. and tolderlund d.s., 1971. distribution and ecology of living planktonic foraminifera in surface waters of the atlantic and indian oceans. in: b.m. funnell and w.r.riedel (editor), the micropaleontology of the oceans. cambridge university press, london, 105-149. blanc-vernet l. and sgarrella f., 1989. assemblages de foraminiferes planctoniques en mer tyrrhénienne et en mer adriatique pendant les derniers 130000 ans. implications paléoécologiques. paleogeogr., paleoclimatol., palaeoecol., 7766: 107-124. blanc-vernet l., sgarrella f. et acquaviva m., 1984. évènements cl imatiques,hydrologie et foraminifères en méditerranée au quaternarie recent. bull. soc. géol. france, xxxxvvii,, 77:12351243. buccheri g., capretto g., di donato v., esposito p., ferruzza g., pescatore t., russo ermolli e., senatore m.r., sprovieri m., bertoldo m., carella d. and madonia g., 2002. a high resolution record of the last deglaciation in the southern tyrrhenian sea: environmental and climatic evolution. marine geology, 118866: 447-470. capotondi, l., borsetti, a. and morigi, c., 1999 foraminiferal ecozones, a high resolution proxy for the late quaternary biochronology in the central mediterranean sea. marine geology, 115533 ((1144)): 253-274 esposito, p., 1999. le associazioni a nannoplancton calcareo del pleistocene superiore-olocene dei golfi di gaeta, pozzuoli e salerno (mar tirreno). biocronologia e ricostruzione paleoclimatica. tesi di dottorato, università federico ii, napoli, 164 pp. fairbanks r.g., 1989. a 17,000 year glacio-eustatic sea level record: influence of glacial melting rates on the younger dryas event and deep ocean circulation. nature, 334422: 637-642. hembleben ch., spindler m. and anderson o.r., 1989, modern planktonic foraminifera. springer-verlag imbrie, j and kipp, n.g. 1971, a new micropaleontological method for quantitative paleoclimatology: application to a late pleistocene caribbean core. in: k. tukerian (editor), the late cenozoic glacial ages. yale univ. press., new haven, 71-191. kallel, n., paterne, m., labeyrie, l., duplessy, j.c. and arnold,m., 1997. temperature and salinity records of the tyrrhenian sea during the last 18 000 years. paleogeogr. paleoclimatol. palaeoecol. 113355:: 97-108. kucera m. and malmgren b.a., 1998. logratio transformation of compositional data – a resolution of the constant sum constraint. marine micropaleontology, 3344: 117-120 margalef r., herrera j., steyaert m. et steyaert j., 1966. distribution et charactéristiques des communautés phytoplanctoniques dans le basin tyrrhénien de la méditerranée en function des facteurs ambiants et à la fin de la stratification estivale de l’année 1963. bull. inst. r. sci. nat. belg., 4422: 1-56 müller c., 1979. les nannofossiles calcaires. la mer pelagienne, 210-220. pujol c. and vergnaud-grazzini c.,1995. distribution patterns of live planktic foraminifers as related to regional hydrography and productive systems of the mediterranean sea. marine micropaleontology, 2255: 187-217 rohling, e.j., 1994. review and new aspects concerning the formation of eastern mediterranean sapropels. marine geology. 112222: 1-28. rohling e.j. and gieskes w.w.c., 1989. late quaternary changes in mediterranean intermediate water density and formation rate. paleoceanography, 44: 531-545. sanford r.f., pierson c.t. and crovelli r.a., 1993. an objective replacement method for censored geochemical data. mathematical geology, 2255 ((11)):: 5979. stuiver, m. and reimer, p. j., 1993. extended 14c database and revised calib radiocarbon calibration program. radiocarbon,, 3355: 215-230. 257effects of late pleistocene holocene ... ms. ricevuto il 30 luglio 2002 testo definitivo ricevuto il 7 gennaio 2003 ms. received: july 30, 2002 final text received: january 7, 2003 imp.albianelli mmaaggnneettoossttrraattiiggrraapphhiicc ddaattiinngg ooff tthhee mmiiddddllee aanndd llaattee pplliioocceennee sseeqquueennccee iinn tthhee mmaarrcchheeaann aappeennnniinneess,, cceennttrraall iittaallyy aannddrreeaa aallbbiiaanneellllii11,, ggiinnoo ccaannttaallaammeessssaa22,, ppeettrrooss ddiiddaasskkaalloouu22,, aauurroorraa mmiiccaarreellllii22,, ggiioovvaannnnii nnaappoolleeoonnee11 && mmaarriiaa ppootteettttii22 1dipartimento di scienze della terra università di firenze (e.mail: albix@geo.unifi.it) 2università di camerino (e.mail: aurora.micarelli@unicam.it) abstract the periadriatic basin of the external apennines is reported for its fermo sector, containing a long sequence of pelites interbedding two major conglomerate complexes, in order to calibrate it to the geomagnetic polarity time scale. the studied succession begins with the 283 meters of mid pliocene pelites in the fosso morignano section, dated from the mammoth magnetochron (3.3 ma) to the latest gauss chron, and calculated by the cyclostratigraphic distribution of its continuous magnetic signal to last until 2.63 ma. the boundary with the matuyama chron (2.58 ma) is placed in the middle of the overlying conglomerate complex of mt. ascensione. the shift from the marl to gravel facies suddenly occurs 50 ky before the gauss/matuyama boundary and is followed in continuity by a new marly sequence lasting nearly 100 ky in the rotella section during the earliest reversed matuyama. a similar depositional cycle, but of shorter duration, is repeated with the offida profile: the 20 m thick basal pelites exposed in the fornace section are dated earlier than the beginning of the olduvai (1.95 ma), while the upper pelites contain almost fully the olduvai split end (1.815-1.785 ma), there included the pleistocene boundary which was dated 1.796 ma in the vrica stratotype. both profiles focused the calibration of the late pliocene and pleistocene boundaries delineated by the microfaunal content, as the globorotalia gr. crassaformis and g. inflata zones were always present throughout the fermo sector, even if their extremes were both missing. this prevented quantifying the stratigraphic relationships between the two sequences, from either the stratimetric or biostratigraphic viewpoints. the present dating revealed a missing time span of roughly 300 ky, including the short normal chron of reunion (2.15-2.14 ma), which may be though represented in other portions of the fermo sector. the correlation of their sequences to one another may be now used as a calibrated signal applied to individual biozones, from the date of nearly 3.3 ma in the mid pliocene through the pleistocene boundary. riassunto e’ stato condotto uno studio magnetostratigrafico sui sedimenti del medio e tardo pliocene della successione pelitica affiorante nel settore fermano del bacino periadriatico (marche meridionali). nella stessa successione già erano state effettuate ricerche stratigrafiche che avevano evidenziato per il suddetto intervallo la presenza delle biozone a globorotalia gr. crassaformis e a globorotalia inflata. a causa delle microfaune talora povere e prive di forme significative, non era stato possibile porre con precisione i limiti biostratigrafici e di conseguenza quelli cronostratigrafici. lo studio magnetostratigrafico ha offerto una maggiore risoluzione con la calibrazione alla scala dei tempi delle polarità geomagnetiche, e ha consentito di verificare nell’appennino centrale quanto evidenziato nello stratotipo della vrica (sulla costa ionica), cioè la presenza del breve intervallo di polarità inversa nell’olduvai terminale nel quale è stato fissato il limite plio-pleistocene. detto evento di polarità inversa è stato già messo in evidenza nella successione continentale del versante tirrenico dell’appennino settentrionale, sicchè nei due versanti la calibrazione di entrambe le serie data le fasi di sollevamento della catena. in particolare, in questa parte esterna dell’appennino, la sedimentazione ha registrato gli eventi di polarità magnetiche nell’intervallo da circa 3.3 ma a 1.7 ma e le variazioni cicliche del segnale magnetico, secondo i periodi di milankovitch, nell’intervallo 3.3-2.6 ma, in base a quanto misurato dalla magnetizzazione residua delle rocce campionate nelle stesse successioni delle analisi biostratigrafiche. nella porzione inferiore della successione, in cui 283 metri di peliti sono stati campionati nel fosso morignano, sono presenti i croni geomagnetici mammoth (3.33-3.22 ma) e kaena (3.11-3.04 ma) a polarità inversa e quello intermedio (3.22-3.11 ma), all’interno della polarità normale gauss che termina all’età di 2.58 ma. infatti, dall’analisi ciclostratigrafica e dalla conseguente velocità di sedimentazione che ne è scaturita, si può ritenere che il crono mammoth sia rappresentato praticamente tutto, mentre superiormente la successione pelitica si arresta circa 50 ka prima del limite gauss-matuyama, misurando il numero di cicli presenti nella durata dei 460 ka del crono c2an.1n. da rilevare che la ciclicità registrata con la maggiore ampiezza ricorre con uno spessore di sedimenti di poco superiore a 40 m che qui è stata interpretata come quella forzata dalle variazioni climatiche legate alla eccentricità breve (100 ka). dalle peliti del fosso morignano si passa con contatto erosivo al complesso conglomeratico del m.te dell’ascensione, che presenta uno spessore di 400 m ed è costituito da cinque corpi grossolani separati da livelli pelitici di modesto spessore. l’analisi magnetostratigrafica ha messo in evidenza che il passaggio dalla polarità normale gauss a quella inversa matuyama, che segna il limite pliocene medio-pliocene superiore a 2.58 ma, avviene nel livello arenaceo-pelitico posto tra il secondo e il terzo corpo conglomeratico. in questo stesso livello si rinviene la prima comparsa di bulimina marginata, la cui calibrazione diretta con il limite pliocene mediopliocene superiore è l’elemento biostratigrafico che caratterizza il limite piacenziano-gelasiano. si può altresì supporre che i primi due corpi del complesso conglomeratico si siano deposti nell’intervallo mancante tra la fine delle peliti e il limite gauss/matuyama, cioè negli ultimi 50 ka; la stessa durata può essere valutata per la deposizione della seconda metà circa del complesso conglomeratico, per cui la durata dell’intero complesso è plausibile in 100 ka. sia la sezione di fosso morignano che quella del monte dell’ascensione sono state riferite alla biozona a globorotalia gr. crassaformis. la sezione delle peliti di rotella, che segue in continuità i conglomerati di m.te dell’ascensione è stata misurata per uno spessore di 45 metri, e ha mostrato una magnetizzazione con polarità inversa. presupponendo anche in questa serie una velocità media di sedimentazione pari a quella calcolata per le peliti della sezione di fosso morignano, si può attribuire a tale sezione una durata dell’ordine di 100 ka. la sezione è riferita alla parte superiore della biozona a globorotalia gr. crassaformis per la presenza del livello a globorotalia puncticulata-inflata, che nel bacino periadriatico marchigiano-abruzzese si rinviene costantemente prima della comparsa di globorotalia inflata. superiormente, continua la successione pelitica con intercalato il complesso conglomeratico di offida dello spessore di 200 m, caratterizzato anch’esso, come quello di m.te dell’ascensione, da cinque corpi conglomeratici. sia le peliti che il complesso di offida sono riferiti alla biozona a globorotalia inflata. quindi, l’analisi magnetostratigrafica ha documentato la presenza del crono olduvai alla base delle peliti immediatamente sopra il complesso conglomeratico di offida. e’ probabile che il passaggio dalla polarità inversa a quella normale olduvai avvenga all’interno del complesso conglomeratico, in corrispondenza del quale non si è potuto effettuare misurazioni. il limite superiore del suddetto crono non è stato raggiunto nella successione esaminata; è stato comunque evidenziato il breve intervallo a polarità inversa, all’interno della parte terminale dell’olduvai, nel quale è stato fissato il limite p/p nello standard della vrica. key words: magnetochronologic calibration, gauss chron, olduvai chron, pleistocene boundary, northern apennines, central italy. parole chiave: calibrazione magnetocronologica, magnetocrono gauss, magnetocrono olduvai, limite plio-pleistocene, appennino settentrionale, italia centrale. il quaternario italian journal of quaternary sciences 1166(1), 2003, 171-183 172 a. albianelli et al. 11.. iinnttrroodduuccttiioonn the magnetostratigraphic study on the middle and late pliocene succession of the external apennines, central italy, was carried out in the fermo sector, one of the three sectors of the periadriatic basin in the marche region, with the aim of calibrating its chronostratigraphic age (fig. 1). in fact, the reconstructions made so far were based on the biostratigraphic correlation between a number of sections, which revealed an essentially continuous sequence, comparable with the best sections where the pliocene to pleistocene stages had been fixed. those studied in the apennines and sicily yielded the last stratigraphic landmarks, formalising the end pliocene with the gelasian stage and the “golden spike” for the pleistocene boundary stratotype by means of their magnetostratigraphic calibrations. for the present stratigraphic assessments, the numerical dates produced by the geomagnetic polarity time scale (gpts), as established by the sea-floor magnetic anomalies, was available according to the revision of the cenozoic and latest mesozoic chronostratigraphy made by berggren et al. (1995) on the magnetic chronology of cande and kent (1992; 1995). another important aim in dating this series was that the present area is closest to the calibrated continental sequences of valdarno and valtiberina of northern apennines, thus leading to the correlation of the main geological events in central italy during some of the most active tectonic phases of their uplift. in particular, this time span, that also witnessed the main climate changes affecting the recent evolution of the geological system and was recognized in the mentioned continental sequences, could be enhanced as a first evidence of the events inferred for the marine sequences by cantalamessa et al. (2002). for this purpose, the magnetic record of the geological time series was processed by cyclostratigraphic treatment, according to the procedures reported elsewhere (napoleone et al., 2003b), while a discussion of magnetostratigraphic correlations between the continental and marine sequences across the central apennines will be reported in a coming paper (napoleone et al., in manuscript). 22.. ggeeoollooggiicc sseettttiinngg aanndd bbiioossttrraattiiggrraapphhiicc aaggeess in the external apennines of central italy, the periadriatic basin was filled by an abundant pile of sediments that concluded the long lasting pelagic deposition. its continuous record in the ital ian peninsula, from the mesozoic platforms through the pelagic carbonates of the umbrian-marchean series, evolved during the neogene to the turbiditic sedimentation. it yielded the asset of the apennine fig. 1 geological sketch-map of the southern marche district. the pliocene and pleistocene deposits outcropping in this portion of the periadriatic basin belong to four sectors: 1) ancona sector 2) macerata sector 3) fermo sector, 4) teramo sector. their three basic units above the pre-pliocene basement are: 1. argille azzurre inferiori; 2. argille azzurre superiori; 3. sabbie e conglomerati di tetto. the sequence of the fermo sector is here investigated. schema geologico del bacino periadriatico marchigiano (settori anconetano, maceratese e fermano) e del settore di teramo. i depositi pliocenici e pleistocenici che affiorano sui terreni pre-pliocenici sono costituiti dalle argille azzurre inferiori, argille azzurre superiori e sabbie e conglomerati di tetto. lo studio ha interessato la successione nel settore di fermo. 173magnetostratigraphic dating ... ridge, and its evolution relative to the fore-deep complex system, during the messinian through the early pliocene (bigi et al., 1995; 1997; cantalamessa et al., 1986; 1997; 2002). while in the eastern side of the apennines the periadriatic basin was affected by marine sedimentation mostly with pelit ic deposits, the late neogene intramontane basins were developed essentially in the western side with continental sediments. in these basins, a major uplift was recorded by the earliest gravel deposits, dated by magnetostratigraphy to have begun at 3.3 ma in the upper valdarno (napoleone et al., 2003a). the evidences leading to the identification of the three sectors of the periadriatic basin in the marche, the sectors of ancona, macerata, and fermo are documented in the studies above quoted. these sectors underwent a differentiate evolution related to the effects, even combined, of tectonic changes and eustatic-climatic changes that conditioned the sedimentary environments, as well as depositional modalities and systems. in the fermo sector the sedimentary sequence is represented, from bottom to top, by the argille azzurre inferiori, argille azzurre superiori, sabbie e conglomerati di tetto (fig. 2). fig. 2 schematic relationships between the plio-pleistocene marine units in the external apennines. the lowermost is montefalcone (a), whose reduced sequence was not examined, overlain by the monte dell'ascensione member (b) and offida member (c). schema dei rapporti stratigrafici tra le unità della successione marina plio-pleistocenica nell’appennino esterno. l’unità di base è quella di montefalcone (a) che non è stata investigata, seguita dai membri di monte dell’ascensione (b) e di offida (c). fig. 3 view of the mt. a s c e n s i o n e gravel complex, exposed for about 400 m above the pelite marl sequence sampled in the fosso morignano section. the 5 marked levels of cong l o m e r a t e s overl ie the pelite marls with a moderate angular unconformity and both are ti l ted to the northeast. p a n o r a m i c a del complesso del m.te dell’ascensione, con circa 400 metri di conglomerati esposti sopra le argille siltose della sezione di fosso morignano. da i a v sono indicati i 5 livelli che insieme alle peliti sono inclinati verso ne e presentano una modesta discontinuità angolare con queste ultime. 174 the argille azzurre superiori, to which the whole examined sequence belongs, are mainly formed by pelitic deposits interbedded at various levels with complex gravel bodies, as the ones of mt. ascensione and offida. three members are recognized in the whole formation: from the bottom, montefalcone, mt. ascensione and offida (fig. 2). the latter two were sampled. the mt. ascensione profile marked the new pelagic deposition after the last turbidites were emplaced in the early pliocene; the sampled section exposed in the fosso morignano is represented by 283 meters of pelites, overlain with an erosive contact by the 400 m thick conglomerates of mt. ascensione which are formed by 5 gravel bodies separated by arenaceous-pelitic thin levels (fig. 3). the end of this profile is represented by ca. 40 m of pelites measured in the rotella section. the offida profile begins with ca. 20 m of pelites sampled in the fornace section, and is overlain with an erosive contact by the 200 m thick offida conglomeratic complex (fig. 4). various authors (pieri & groppi, 1981; cremonini & ricci lucchi, 1982; cantalamessa et al., 1986; 2002) interpreted this discontinuity as the effect of a further major tectonic pulse, which led to the final asset of the apennine range. as for mt. ascensione, the 5 gravel bodies forming it are separated by thin arenaceous-pelitic levels, while the pelitic facies overlying in continuity is represented by nearly 60 m, whose uppermost portion was sampled in the colle tafone section. the ends of both profiles resulted of decisive importance for the interpretation of the biostratigraphic reconstruction, in order to reduce the range of incertitude of the globorotalia gr. crassaformis and globorotalia inflata biozones which defined the age of the sequence with further details provided by several episodes (cantalamessa et al., 2002). at the base of the succession, globorotalia bononiensis is associated with globorotalia crassaformis, and upwards the main events are represented by the onset of bulimina marginata followed by the globorotalia puncticulata-inflata bio-horizon. globorotalia inflata was first noticed in the offida gravel complex, while its absence in the underlying pelites (fornace section) was possibly related to an ecologic exclusion. this interpretation will be clarified after the magnetostratigraphic results be discussed. 33.. pprreevviioouuss ccaalliibbrraattiioonn ooff aappeenn-nniinnee sseerriieess ffoorr tthhee mmiidd aanndd llaattee pplliioocceennee aaggeess the studied marchean series will represent in italy the first calibrated one by direct magnetostratigraphic dating after the stratotype at vrica, southern italy, established for the plio-pleistocene boundary (van couvering, 1997), as both related to the gpts. this tight correlation would add a special relevance to the classical italian areas where the neogene and quaternary ages were investigated since the earliest sedimentologic and biostratigraphic studies, because the asset of the boundary stratotype would be tested throughout a long magnetostratigraphic sequence. the twofold pliocene age was used until less than a decade ago, with its late portion identified as the piacenzian stage. it was fixed in the mid eighteen hundreds in the piacenza area of the northern apennines, on famous sections which still provide detailed evidences of major changes that occurred in proximity of the plio-pleistocene boundary (raffi et al., 1989). among them, two main points were lately emphasized. the first one deals with the pliocene warm-water bivalve taxa and fishes which disappeared before the end of the piacenzian (monegatti & raffi, 2001; sorbini, 1988), as defined by pareto (1865) and used until the mentioned splitting into the gelasian new stage. this disappearence was dated within that of discoaster tamalis and d. fig. 4 an exposure of the erosive contact between the offida gravel complex (a) and the underlying pelites of the fornace section (b), in the outskirts of offida. contatto erosivo tra il complesso conglomeratico di offida (a) e le sottostanti peliti della sezione di fornace (b), alla periferia di offida. a. albianelli et al. 175 surculus confining the nannofossil biozones mnn 16b17, i.e. close to the onset of the glacial-pliocene (ciaranfi & cita, 1975; shackleton et al., 1984; zagwijn, 1992). the second point was that the sections of the area appeared inadequate to represent the transition from the end of the piacenzian to the pleistocene, due to a significant gap. this was fulfilled in the deposits of the gela sequence, southern sicily (cita & castradori, 1994; rio et al., 1994; 1997). the gelasian was there established (van couvering, 1995) for the late pliocene, and thus the best studied series of these critical ages of piacenzian and gelasian resulted in the extremes of the apennine mountain belt. however, the stratigraphic resolution in the present marchean sections was until now devoid of a similar accuracy, because of a lesser resolutive biozonation with planctonic foraminifera and poor nannoplankton preservation. on the other hand, magnetostratigraphy actually failed calibrating the p/p boundary in the northern area because of the incomplete extent of the gelasian stage and the disconformity with the pleistocene series, for the santernian stage in the santerno section (tric et al., 1991; mary et al., 1993). during the interval across these ages, tectonics must have been actively uplifting the northern apennines, and thus most deposits in the end-olduvai chron were eroded, while instead yielded at vrica the key elements to fix the “golden spike” gssp for the p/p boundary (van couvering, 1997). in central italy, in contrast, the pliocene sediments focused special attention since the mid 18 hundreds also on the continental deposits of the intermontane basins (cocchi, 1856; pareto, 1865), mainly because their vertebrate faunas contributed to the development of paleontology (nesti, 1811; 1825; cocchi, 1867), and of its later use for geochronological meanings (azzaroli, 1983; azzaroli et al., 1997). thence, several marine sequences have been studied in the range of ages between the late pliocene and early pleistocene, among which are the thick ones bordering the valdichiana basin (south of the upper valdarno) and farther to the east (beyond the watershed), in the external apennine periadriatic basins. the latter were recently investigated correlating a number of sections (cantalamessa et al., 2002). a long pliocene time span was recognised in the series, as well as its continuation into the pleistocene, but the p/p boundary was not satisfactorily identified with biostratigraphy. the main aim of the present work is for that reason to date, with the high resolution of the gpts numerical scale, one of the longest series studied for the middle and late pliocene, and likely correlate its p/p boundary with the stratotype section. under such conditions, both sides of the northern apennines in central italy would also be correlatable with the highest accuracy, their continental and marine deposits having both been dated with magnetic stratigraphy. 44.. mmaaggnneettoossttrraattiiggrraapphhyy the profiles reconstructed from the paleomagnetic measurements were sampled in the same sections studied for biostratigraphy, in order to directly calibrate the ages of the latter to the magnetochronology of the gpts dates. biostratigraphic characterization of the series was well established by the previous studies, and yielded a long mid and late pliocene sequence (cantalamessa et al., 1986; 2002; bigi et al., 1995; 1997). the magnetic polarity zonation was here established after the rock-magnetic properties had been tested, and the correlations of the biostratigraphy with it represent the main result. therefore, next chapters will mostly report on the magnetic calibrations with discussion of the results which clarify the chronostratigraphic asset of the series with the magnetic polarity zonation. 44..11 mmeetthhooddss aanndd mmaatteerriiaall magnetostratigraphy of the present sequence is in the fermo sector based on the polarity changes of the paleomagnetic vector reconstructed through the profiles, which will be shown below as the conclusive result after a series of analyses. the measurements were carried out at the magnetic laboratory of the eth in zurich, on cubic specimens taken from oriented hand-samples. some specimens were used for the tests on rockmagnetic properties, and most of them to measure the fossil vector of the natural remanent magnetization (nrm), having isolated the primary magnetization. this procedure was used by applying increasing temperatures for cleaning the paleo-vector from possible overprinted magnetizations, and thus recognizing the stable directions carried by a predominantly magnetite composition of the magnetic minerals. for this purpose the magnetic saturation of the samples and its subsequent thermal stepwise demagnetization were applied. two samples of the mt. ascensione unit (fig. 5a) showed a fig. 5 (a) saturation of the isothermal remanent magnetization (irm) in two samples from the pelite sequence of fosso morignano showing the behavior of a low coercivity mineral phase, such as magnetite (b). (a) curve di saturazione della magnetizzazione residua isoterma (irm) di due campioni della serie pelitica di fosso morignano che riportano il comportamento di bassa coercitività di una fase mineralogica come quella della magnetite (b). magnetostratigraphic dating ... 176 low coercivity behavior, typical of minerals as magnetite and sulphides. the latter are though very sensitive to temperature and at nearly 300-350 °c produce a new phase of magnetite, while in the present case all samples passed such steps without any deviations disturbing the identification of the virtual geomagnetic pole (vgp) latitudes. these ultimately led to the interpretation of the magnetic polarity zonation through the sequence, which, moreover, showed a remarkable uniformity in its magnetic mineralogy, because of the parallel trends of the nrm and susceptibility curves (fig. 5b). an example of the straight direction of the nrm decreasing values toward the origin of the axis after heating is shown in figure 6, for the representative units. from the top, two samples of reversed and norfig. 6 the zijderveld polar diagrams show the directions of the paleomagnetic vector pointing straightforward to the origin, unaffected by secondary magnetizations. thermal demagnetization by stepwise increasing temperatures did not enhance mineral changes, thus confirming that the primary magnetization was mainly carried by magnetite. una serie di diagrammi polari che mostrano le direzioni del vettore paleomagnetico puntare direttamente verso l’origine, senza particolari deviazioni indotte da magnetizzazioni secondarie sovrapposte a quella iniziale durante la deposizione. le graduali smagnetizzazioni termiche non hanno evidenziato variazioni mineralogiche, confermando perciò la presenza di magnetite come responsabile della magnetizzazione primaria. a. albianelli et al. mal polarities are shown for the offida profile. on the left diagram a typical change in both directions, inclination and declination, is shown as a field acquired in the present normal polarity which was removed since the initial steps of demagnetization. in the rotella section, only one reversed polarity is recorded, while the graphs for the mt. ascensione indicate that both signals descend from stable magnetizations of well aligned particles. another important analysis, the cyclic stratigraphy of the magnetic signature, was applied to control the magnetic stratigraphy in defining the duration of the long magnetozone at the critical change from the gauss to matuyama chron. its results are illustrated as first, because they relate to the basal sequence for a long time span through the middle pliocene and complete the polarity zonation for the magnetostratigraphic interpretation. 44..22 mmaaggnneettiicc ccyycclloossttrraattiiggrraapphhyy ooff tthhee ppiiaacceennzziiaann ppeelliitteess the paleomagnetic vector parameters, measured for the basal sequence of fosso morignano, revealed, in directions (inclination and declination) and intensities (nrm and susceptibility), a cyclostratigraphic content of the signal in the range of the milankovitch periods. the duration of the latter was well constrained by the magnetic stratigraphy, whose reliability is marked also by the parallel pattern of the nrm and susceptibility, shown in figure 5b as an evidence that the magnetic signal was carried only by all aligned fine particles. in figure 7a, only the susceptibility curve is shown; the power spectra were processed in the whole time series of 283 m, which enhanced in the diagram by the side the period distribution of the milankovitch indexforced sedimentation (fig. 7b). the procedures here applied were used for the coeval series of continental deposits in the intramontane basins, to illustrate the evaluation of the climate changes in the middle and late pliocene and as a further refinement of the magnetostratigraphic dating (napoleone et al., 2003a,b). the results from the present marine series are used straightforward with that aim of better timing the sedimentary events driven by the climate changes, and thus first discussed for the diagram of the bulk time series of the fosso morignano section. its spectrum (fig. 7b) showed only one prominent peak, the 41.8 m cycle, interpreted as the index-forced sedimentation by the short-eccentricity cycle at 100 ky, as inferred from the following magnetochronologic constraints of the polarity sequence. in the gpts (cande & kent, 1995), the late gauss chron extends over 460 ky (see also in the next chapter) and would thus contain 4.6 of such eccentricity cycles. in the actual profile, the uppermost magnetozone of normal polarity extends from top of the kaena, placed at 165 m depth, to the end of the section. at the rate of 41.8 m/100 ky its full time span should extend over a 190 m thick pile, which means that the latest gauss chron was recorded for only 165 m, from the kaena to the top, and therefore a 20-25 m slice was missing before reaching the boundary under the steady sedimentary conditions of pelitic deposition. and this also means that, at the rate just said before, a 50 ky duration was not recorded in the pelitic marls. more discussion should be done on the cyclostratigraphic content of the profile regarding the absence of the short period cycles, because the time resolution of the sampling rate was similar to that used for the continental sediments of the upper valdarno and valtiberina (napoleone et al., 2003a,b) and for the late albian pelagic carbonates of the umbrian series (napoleone & ripepe, 1989). the precession and obliquity index-forced sedimentation there produced distinct peaks, in either susceptibil ity and nrm spectra, or in the directions, also for the shorter periods of obliquity (40 ky) and precession (20 ky). these short period cycles were searched by processing the present 177 fig. 7 cyclostratigraphic analyses on the fosso morignano series. the continuous changes, in the time series of 283 m, of the magnetic signature (a) are processed for the susceptibility signal by the enhancement of the spectra of the period amplitudes. the whole time series evidenced a fundamental period of 41.8 m, as shown in the diagram by the side (b). the split portions, from top to 195 m, to which corresponds a date close to the base of the kaena chron shown in (c), and the lower series from there to the bottom in (d), provided quite different spectra. that one in (c) showed the same basic period at 40 m and the additional peaks at 16 m and 8 m, which coincide with the obliquity and precession-forced sedimentation of the astronomical parameters driving the climate changes, while in the lower section the cyclicities are all represented by the short-eccentricity cycle. analisi ciclostratigrafica della serie di fosso morignano. le variazioni continue del segnale magnetico della suscettività lungo la serie temporale dei 283 m di peliti (a) forniscono gli spettri di ampiezza dei periodi presenti: la serie complessiva contiene un solo periodo dominante, di 41.8 m (b), attribuito all’influsso delle variazioni astronomiche della eccentricità breve sulle condizioni climatiche, mentre, suddivisa in due porzioni, mostra tre picchi ben distinti fino a 195 m (c) corrispondenti ai periodi dell’obliquità e della precessione, e il solo picco di 40 m, fino alla base (d), che aveva dominato in tutta le serie. magnetostratigraphic dating ... series in two steps. first, the upper 195 meters, approximately containing the latest gauss and the kaena magnetochrons, were considered using the same constraints as for the entire series; it yielded the power spectrum shown in figure 7c. the magnitude of the power content was distributed in three strong peaks, at 8 m, 16m, 40m, which are exactly in the ratios of the milankovitch index periods, as recorded by various proxies (see, for example, tiedemann et al., 1994) and despite their variability (shackleton, 1995). the spectrum for the lower section, 195-283 m (fig. 7d), was more confused, and devoid of the short cycle peaks quite closely reproducing the pattern of the bulk profile of the upper spectrum (fig. 7b). such a behavior was also found for the mesozoic turbiditic carbonates of the external apennine sequence, where repeatedly short-term disturbances and well recognized in its sedimentation pattern as continuous resedimentation episodes altered the spectral content in the short period indexes (albianelli et al., 2003). in the present time series, all this is supported by the presence of strong magnetostratigraphic constraints, later shown in figure 8. the three chrons before the latest gauss (c2an.1n) are respectively lasting in the gpts 70 ky, 110 ky, 110 ky, which at the still constant rate of 40 m/100 ky would imply thicknesses of nearly 30 m, 45 m, 45 m. this is not the present case, because already the upper magnetozone, at the kaena chron, contains only a little more than half the thickness required by the fully sedimented sequence: but, even more so the underlying normal chron does. our explanation for their reduced extent is that about a 25 m section, distributed on both magnetozones, is missing and actually obliterated by a slice of sediments slipped undisturbed during the emplacement of the sequence or later. the lower portion, with reversed polarity, is even more effectively altered, up to a duplication of its thickness. the spectral distribution seems to confirm this hypothesis, because the short cycles are more disturbed by the sampling rate at 1m spacing. 44..33 mmaaggnneettoossttrraattiiggrraapphhiicc pprrooffiilleess the interpretation of the magnetic polarity zonation identified two profiles, the mt. ascensione and the offida profiles, both reaching an important boundary, the late pliocene and the pleistocene. for this purpose, all samples were demagnetized as in figure 5; the characteristic direction of each one was taken to indicate the primary magnetization, yielding the directions used to calculate the virtual geomagnetic pole (vgp) latitudes. the full set of samples represented the succession of the fossil-vector directions, and these were used for interpreting the polarity sequence in both profiles, as discussed below. 4.3.1 calibration of the mt. ascensione profile as the earliest gelasian the magnetostratigraphic sampling was scanty in the few silty-sand levels of the 400 m thick conglomerate complex of mt. ascensione. in the fine grained material between the second and third level from the base, one sample recorded a reversed polarity, above one sample with the normal polarity (fig. 8). downwards, the 283 m of the examined fosso morignano sequence, which is separated from the gravel by an erosive surfa178 a. albianelli et al. ce, showed on top a long normal polarity. its duration preceding the middle/late pliocene boundary was calculated since the lower time-marker measuring the milankovitch cycles there recognized with the criteria used for the upper valdarno and valtiberina (albianelli et al., 1999; napoleone et al., 2003a). as aforesaid, the boundary of the matuyama chron (2.58 ma) was found ca. half-way in the conglomerate complex, and the latest gauss was still incomplete in the pelite marls. the estimation of the time span needed for the conglomerate deposition was out of the biostratigraphic resolution, nor was resolved by the comparative analysis of the sedimentary characters discussed in cantalamessa et al. (2002), but provided by the cyclostratigraphic content of the susceptibility record (fig.7). in the present sequence of fosso morignano, a normal polarity was recorded from top to 165 m of stratigraphic depth, followed by nearly 30 m of reversed polarity and 20 m of normal polarity; the end section was again in a reversed magnetozone. the profile is then interpreted as made of two reversed magnetozones, prior to the latest gauss dated 3.04 ma in the gpts geochronology, and correlated with the kaena (3.113.04 ma) and mammoth (3.33-3.22 ma), respectively, with its normal chron (3.22-3.11 ma) there enclosed. these three dates represent tight constraints on the pelite series, whose extremes were also defined with a still high resolution: the upper extreme was found at 2.63 ma with an accuracy better than 10 ky from the cyclostratigraphic resolution (fig. 7c), and the lower extreme being inferred of the same order of magnitude, as the mammoth 110 ky are already represented by a thick pile of sediment. from such markers, a thinning of the short normal and a much larger thickness in the mammoth are evident, if the accumulation rate would have been steady, and accounts were given for the disturbances in sedimentation rates that affected the spectral analysis of the continuous magnetic signal. upward in the profile, above the conglomerate complex, the mt. ascensione profile was completed by the rotella section, which followed in continuity with the pelites measured for nearly 45 m. its magnetic record showed only one reversed polarity, in the earliest matuyama, for a time span which will be discussed later on, and begins 50 ky after the boundary, the normal chron of reunion not being reached. nor was it found in the exposure of the fornace pelites underlying the offida gravel complex, which still continued recording a reversed magnetozone. the sampling in it was more than 2 m spaced. 4.3.2 calibration of the offida profile to the late gelasian the composite profile shown in figure 8 assembles all sections surveyed with the magnetic stratigraphy, which are though discussed individually. for example, the uppermost section of the profile, sampled at a much closer spacing than that used for the others, contains the p/p boundary close to the end of the olduvai, in the short profile measured at the colle tafone section. also the vrica stratotype with its split olduvai is represented for comparison by the side. the p/p boundary, placed just before the end of the olduvai, is one of the most significant tie points marked on the whole profile, together with the late pliocene boundary, which had been calibrated to the gauss-matuyama 179 figure 8 the magnetochronologic conclusive asset of the series of pelitic-and-coarse deposits here studied yielded dates from nearly the base of the globorotalia gr. crassaformis of the early piacenzian to the top of globorotalia inflata biozone in the gelasian stage, concluding the pliocene in the split olduvai. the numerical dates of the gpts are 3.33 ma for the base of the mammoth, 3.22 ma for the base of the normal chron before the kaena at 3.11 ma, and 3.04 ma for the base of the latest gauss. the dates for the succeding matuyama and olduvai are a little less accurate, due to interruptions of the series: the first and longest one of 300 ky in correspondence with the reunion chron (2.15-2.14 ma), is followed by a possibly short one at the onset of the olduvai (1.95 ma). diagramma conclusivo dell’assetto magnetocronologico della serie pelitica con i suoi depositi conglomeratici, a partire quasi dalla base della biozona a globorotalia del gr. crassaformis del piacenziano inferiore fino alla fine di quella a globorotalia inflata del gelasiano, che conclude il pliocene all’interno della breve inversione alla fine dell’olduvai. le date numeriche nella scala dei tempi magnetici gpts partono da circa 3.33 ma alla base del mammoth e toccano 3.22 ma dell’intervallo a polarità normale prima del kaena a 3.11 ma e 3.04 ma dell’inizio del gauss terminale. quelle successive del matuyama e dell’olduvai sono meno accurate a causa delle interruzioni nella serie: la prima è risultata di circa 300 ka in corrispondenza del crono reunion (2.15-2.14 ma) ), e la seconda, più breve, in corrispondenza dell’inizio dell’olduvai (1.95 ma). magnetostratigraphic dating ... boundary of the gpts, at 2.58 ma. therefore, the beginning of the gelasian stage was marked by this date correlated with the middle of the conglomerate section (between its second and third boulder episode), for a time span calculated according to the previously determined tie-points. the date of the top of the underlying pelite resulted only 50 ky older than the gauss/matuyama boundary, as provided by the cyclostratigraphic record. this implies that also the upper half of the conglomerate body may be assigned the same duration of nearly 50 ky, and the overlying pelite of the rotella section would thus begin not later than 2.53 ma, while its duration will be discussed in the next chapter. the gelasian profile, in the surveyed area, was extended into a separate pelite sequence exposed in the fornace section. it still recorded a reversed polarity, interpreted as shortly preceding the onset of the olduvai, while the pelites above the conglomerate recorded a normal polarity, i.e. they were deposited during the olduvai chron. the transition should have occurred in the gravel complex. the smaller thickness of the offida gravel body, compared with that (almost double) of mt. ascensione, would not imply a shorter duration, as the same five episodes of boulder banks separated by the thin pelite levels are recognized. a half rate of deposition would account for the same time span as that in mt. ascensione, and the sedimentary conditions for such a smaller rate may be related to a more distal position from the ridge of the offida body than that of mt. ascensione. with such time constraints, the profiles of mt. ascensione and offida in figure 8 are fully correlated with the gpts, only one tie point remaining less tightly constrained, the un-defined portion of the conglomerates matching the olduvai boundary at 1.95 ma. the underlying and overlying pelites would date few tens of ky earlier and later than the boundary, respectively. the remaining olduvai profile was completed by the new sequence sampled at colle tafone, on the road from offida to castignano. this contains the uppermost olduvai with the same split interval as in the vrica stratotype, whose short reversed portion was dated 1.815 to 1.785 ma. the end of the normal chron (1.770 ma) was there not reached, but only a few meters are lacking to it, considering that nearly 10 ky are missing. 55.. ddiissccuussssiioonn oonn tthhee mmaaggnneettoocchhrroonnoollooggiicc sseettttiinngg an evaluation of dates at great resolution may be now summarized with these magnetostratigraphic details, on which the aforesaid results are based. the mt. ascensione lower profile was, indeed, better specified in its sedimentation rates, as accounted by the spectral processing of the time series. here, only the dates for the sequence above the mt. ascensione gravel complex will be further discussed. the rotella sequence was already dated 50 ky after the gauss/matuyama boundary; its duration would have been ca. 100 ky, if the sedimentation rate was the same as for the earlier pelite deposition, which was averaged at nearly 40 m/100 ky in the spectral analysis, and its date would be placed at 2.53 to 2.43 ma. the next fornace section, in the outskirts of offida, remained poorly constrained between the end-reunion (2.14 ma) and the olduvai onset (1.95 ma). previous lithoand biostratigraphic reconstructions would poorly define the uppermost globorotalia crassaformis biozone passing to the next one of globorotalia inflata, as the zonal marker is present only in the lowermost offida gravel levels. in that scheme, the fornace section would be assigned an age with a wider range of incertitude in the globorotalia crassaformis biozone, which might be reduced by the present magnetostratigraphic date, after some considerations to be pointed out. also this 20 m thick section, underlying the offida gravel body with an evident unconformity (fig. 4), would have lasted ca. 50 ky, if sedimentation remained at the same rate as before. the problem arises when considering that its magnetic signature was in a reversed polarity, and therefore its date somewhat earlier than the transition to the olduvai normal chron at 1.95 ma. this implies that the whole lower matuyama, lasting 630 ky from the boundary placed in the mt. ascensione gravel unit (2.58 ma) to the onset of the olduvai (1.95 ma) in the offida gravel unit, would be represented by less than 80 m of pelites from the rotella and fornace sections. this gap is now considered as covered elsewhere in the fermo sector, e.g. farther away in the colle cilestrino and castignano sequences. the missing part, including the reunion chron (2.15-2.14 ma), and the shortness of the sequences here prevented the spectral analysis for the milankovitch cycles recognition, and the gap could not be much better placed in the gpts. however, a finer magnetostratigraphic assignment may be attempted placing the fornace section close to the olduvai boundary, or at least younger than the reunion, presuming that the slight angular discontinuity of the offida gravel complex on it would not too much differ from the mt. ascensione one on the fosso morignano pelites. in the upper profile, lacking the cyclostratigraphic resolution, the biostratigraphic dating was unable to specify the duration of the missing portion. an upper limit for the date of the bottom of the fornace section would not be younger than 2.0 ma, and a lower limit not older than 2.14 ma. the missing sediments between the rotella and fornace sections would at least extend over 2.43 to 2.14 ma. on the other hand, the 45 m of pelites, overlying the offida conglomerate in continuity, extended over a normal interval spanning between 1.95 ma (at most, if the onset of the olduvai was on top of the conglomerate), but not reaching 1.815 ma. between these limits, its suggested date could average 1.93 ± 0.02 ma to 1.84 ± 0.02 ma, which seems a good compromise for a duration shortly longer than 100 ky within the 1.951.815 ma interval, and the allowance of 20 ky for the error bar. similarly, a duration in the order of 100 ky would not contradict an accumulation rate as the nearly 40 ky interval represented by the next 17 m section, containing the split olduvai on top of the profile. for the end of this profile, the biostratigraphic record indicated the latest gelasian age, marked by the presence of bulimina elegans-marginata, globigerina calabra, g. calida, etc. thus, the normal polarity in the uppermost marls -not in contact with those immediately overlying the offida gravel complexwould indicate the presence of the olduvai chron before its split interval, where the p/p boundary was calibrated in the vrica stratotype. all these olduvai dates provide very sharp time 180 a. albianelli et al. signals, altough that at 1.95 ma in the gpts was impossible to sample in the scanty fine-grained marls within the gravel layers of the offida complex. the overlying section was fully contained in the lower olduvai portion, whose end at 1.815 ma was found in the colle tafone section with the short reversal until 1.785 ma. in this split olduvai portion the p/p boundary was marked at 1.796 ma, and such a tight correlation thus becomes the highest geochronologic resolution ever reached on italian land exposed pliocene series, in spite of the shortness of both sections which prevented the cyclostratigraphic reconstruction. the results of the previous dates, adding to the mt. ascensione dates, summarize more than 1.5 my calibrated by several tie-points to the gpts magnetochronology, thus leading to the cumulative representation of the middle and late pliocene interval in the periadriatic basin deposits (fig. 8). starting from nearly the base of the mammoth, at a date of 3.3 ma, the continuous sedimentation in the pelitic marls recorded the kaena at 3.11 ma and the polarity event between them at 3.22 ma; the following uppermost gauss chron (3.04 ma) almost reached in the marls its end of 2.58 ma, missing only the last 50 ky, as shown in the cyclostratigraphic reconstruction. the magnetostratigraphic reconstruction yielded the occurrence of the gauss/matuyama boundary in the overlying conglomerate, which led to this important result: the mt. ascensione complex represents the stratigraphic continuation of the pelites. the possible gap involving such a deep change in the sedimentary regime would have been confined in a very few ky, which was recognized also in the adjacent intermontane basins (napoleone et al., 2003a) and will be further discussed in a forthcoming paper. at the onset of the matuyama chron, a time span of the same short duration may be lacking in the overlying marls, while a much longer one was measured after these latter of the rotella section of reversed polarity, which did not reach the reunion (2.15 ma). the section just below the offida gravel complex was biostratigraphically placed close to the p/p boundary: although its paleomagnetic vector still recorded the reversed polarity preceding the olduvai, and not necessarily too much close to the boundary from the biostratigraphic age resolution, one may mantain its date younger than the reunion. thus, the profile before the base of the olduvai can likely begin in the fornace section not later than 2.0 ma and only shortly after the reunion, and its estimated time span of nearly 50 ky could be best positioned between 2.1 ma and 2.0 ma. finally, the sampled pelitic marls above the gravel complex can be dated from shortly younger than 1.95 ma to few ky older than the short reversal at 1.815 ma, which is the lower limit of the split end-olduvai; its record would range no more than 1.93 ± 0.02 ma to 1.84 ± 0.02 ma. as already noted, both important markers, the short reunion (2.15-2.14 ma) and the olduvai onset (1.95 ma) were not found, due to interruptions of the series at their occurrence. but the uncertainties on their position are rather reduced. in particular, magnetostratigraphy dated the interruption of the former with the inferences discussed so far, although with lesser accuracy than that yielded by the cyclostratigraphic processing in the lower sequence of mt. ascensione. 66.. ccoonncclluussiioonnss the criteria for correlating the chronostratigraphic units in the pliocene periadriatic basin sequences resulted largely improved by the present magnetostratigraphic asset. occurrences of the various sedimentary events on the apennine sequences, of either marine or continental origins, could actually be detected under variable conditions, and their accurate dating provided. precise dates could be fixed for 1.5 my of the studied sequence in the fermo sector, southern marche, and with several tie-points to the geomagnetic scale gpts. a finer resolution was added by the cyclostratigraphic analysis of the continuous time series for more than 0.6 my in its lowermost interval. two profiles were reconstructed, that of mt. ascensione and that of offida. in the former, the beginning of the polarity zones was in the gauss sequence at nearly 3.3 ma of the mammoth chron, and in the latter the direct calibration to the gpts, extended almost until the end of the olduvai chron at 1.77 ma, including the plio-pleistocene boundary, which was fixed at 1.796 ma in the vrica stratotype. two more time markers in this 180 ky spanning chron added a higher resolution with its splitting, as in the stratotype section, while further increse of dating resolution in the lower sequence were obtained with spectral analysis of the continuous magnetic changes recorded through the gauss. magnetostratigraphy then revealed also polarity events of 70 and 110 ky durations, which accounted for a steady deposition rate of the upper half of these pelites, while in their lower portion the cyclostratigraphic signal was recorded somehow confused in the three polarity zones from kaena through the mammoth. another important result was found in the uppermost levels, because only 50 ky were lacking before the gauss/matuyama boundary, while magnetostratigraphy placed the latter in the mid mt. ascensione gravel complex. therefore, the reduced duration of the pelitic deposition was fully replaced by the nearly 200 meters of conglomerates without implying the removal of a noticeable part of them during the emplacement of the gravel complex. actually, magnetostratigraphy showed that in the gauss chron a slice of sediment was lacking in the kaena reversed magnetozone and in the normal one below it, while the mammoth chron was almost doubled in thickness when comparing the duration of the chrons in the gpts with the thicknesses of the magnetozones recorded in the overall 283 meters of the mt. ascensione marls. such thicknesses, and speciallly that of the mammoth chron, would be related to anomalous synsedimentary accumulation more than to changing sedimentation rates. an important find was dated in correspondence with the gauss-matuyama polarity change with the first occurrence of bulimina marginata; the fact that this form is directly calibrated to the middle-late pliocene boundary represents the biostratigraphic element characterizing the piacenzian-gelasian boundary. one more result was obtained dating the duration of the tectonic activity that shortly interrupted or reduced the deposition. in these marine deposits the first tectonic phase took place at the gauss-matuyama boundary (2.58 ma), spanning 100 ky across it, during which the 400 m thick mt. ascensione body was rapidly emplaced until the 181magnetostratigraphic dating ... earliest matuyama. thus, the new pelitic sequence deposited in continuity over the conglomerate was sampled for its first 100 ky, at rotella, while the following more than 300 ky are not present in the investigated area, and will be likely measured in the colle cilestrino and castignano sections. the basal unit of the offida profile consists of a pelitic facies similar to that exposed at the base of mt. ascensione, and is overlain by a similar gravel complex, made of the same five episodes, but only 200 m thick, with an unconformity present at its base. this phase took place at the olduvai boundary (1.95 ma), spanning 100 ky across it, and was followed in continuity by a fairly thick pelitic succession, referable to the uppermost pliocene and pleistocene. the first 60 m of this sequence were investigated, and the end of the olduvai was almost reached at the colle tafone section, on the road from offida to castignano. this chron was recorded also with the split short reversal which contained the plio-pleistocene boundary at 1.796 ma in the vrica stratotype. finally, the pelite deposition was interrupted soon after the boundary, and this date can be applied to confine the tectonic phase which led the marine sequence moving to the quaternary sandy deposits of the regressive cycle. more details on this new chronicle of the depositional history are under study on both sides of the apennine margins, and will be possibly extended to the santernian-sicilian ages, i.e. calibrated to the jaramillo and late matuyama chrons. however, the asset reconstructed in the present investigation seems sufficient to emphasize the entirety of the correlation potentialities inherent in the numerical dating of magnetostratigraphy, also in presence of fragmentary sequences of the periadriatic basin here presented, like that of the offida profile in the fermo sector. rreeffeerreenncceess albianelli a., 1995 proprietà magnetiche e magnetostratigrafia dei sedimenti anossici fluvio-lacustri e marini coevi. phd. diss., univ. of firenze, 139 pp. albianelli a., bertini a., magi m., g., napoleone g. & sagri m., 1995 il bacino plio-pleistocenico del valdarno superiore: eventi sedimentari, paleomagnetici e paleoclimatici. il quaternario, 88, 11-18. albianelli a., azzaroli a., bertini a., ficcarelli g., napoleone g. & torre d., 1997 paleomagnetic and palynologic investigations in the upper valdarno basin (central italy): calibration of an early villafranchian fauna. riv. it. paleont. strat., 110033, 111-118. albianelli a., bertini a., hinnov l.m., napoleone g. & fischer a.g., 1999 mid pliocene climatic change in the valdarno basin, italy paleomagnetic exploration of lacustrine sediments at the milankovitch scale. gsa ann. mtg, 25-28 oct., 1999, denver (co). (abt) albianelli a., magi m., mazzini m. & napoleone g., 2002 the plio-pleistocene boundary in the northern apennine continental deposits as defined by the faella magnetostratigraphic section in the upper valdarno. mem. soc. geol. it., pialli special vol. 1, 473-479. albianelli a., galli m.t., gorla l., lottaroli f., napoleone g., petrizzo m.r., premoli silva i. & valdisturlo a., 2003 a turbiditic upper cretaceous scaglia dated from integrated cyclostratigraphy of core and well data of a deep bore-hole. aapg int. conf., barcelona, sept. 2003, abt. azzaroli a., 1983 – quaternary mammals and the “endvillafranchian” dispersal event. a turning point in the history of eurasia. pelaeogeogr., palaeoclim., palaeoecol., 44, 117-139. azzaroli a., colalongo m.l., nakagawa h., pasini g., rio d., ruggieri g., sartoni s. & sprovieri r., 1997 the pliocene-pleistocene boundary in italy. in: van couvering j.a., (ed), the pleistocene boundary and the beginning of the quaternary: world and regional geology series, 9, cambridge univ. press: 141-155. berggren w.a., kent d.v., swisher iii c.c. & aubry m.p. (1995) a revised cenozoic geochronology and chronostratigraphy. am. ass. petrol. geol., sepm special publ., 54: 129-212. bigi s., cantalamessa g., centamore e., didaskalou p., micarelli a., nisio s., pennesi t. & potetti m., 1997 the periadriatic basin (marche-abruzzi sector, central italy) during the plio-pleistocene. giornale di geologia, 5599, 245-259. cande s.c. & kent d.v., 1992 a new geomagnetic polarity time scale for the late cretaceous and cenozoic. jour. geophys. res., 9977, 13,91713,951. cande s.c. & kent d.v., 1995 revised calibration of the geomagnetic polarity time scale for the late cretaceous and cenozoic. jour. geophys. res., 110000, 6,093-6,095. cantalamessa g., didaskalou p., micarelli a., pennesi t. & potetti m., 1997 depositional, environmental and microfaunal associations in the sicilian of the periadriatic marche basin (central italy). boll. soc. paleont. it., 3366, 123-134. cantalamessa g., centamore e., didaskalou p., micarelli a., napoleone g. & potetti m., 2002 elementi di correlazione nella successione marina plio-pleistocenica del bacino periadriatico marchigiano. studi geologici camerti, n. ser., 11, 33-49. ciaranfi n. & cita m.b., 1975 paleontological evidence of changes in the pliocene climates. initial rep. deep sea drilling project, 1133, 342-361. cita m.b. & castradori d., 1994 workshop on marine sections from the gulf of taranto (southern italy) usable as potential stratotypes for the gssp of the lower, middle and upper pleistocene. i l quaternario, 77, 677-692. cocchi i., 1856 description des roches ignées et sedimentaires de la toscane dans leur succession géologique. bull. soc. géol. france, 1133, 226-301. cocchi i., 1867 l’uomo fossile nell’italia centrale. studi paleontologici. mem. soc. it. sci. nat., 22, 1-80. milano. lowrie w. & alvarez w., 1980 one hundred million year magnetostratigraphic history of the umbrian series. jour. geophys. res., 8855, 6,093-6,095. mary c., iaccarino s., courtillot v., besse j. & aissaoui d.m., 1993 magnetostratigraphy of pliocene sediments from the stirone river (po valley). geophys. j. int., 111122, 359-380. 182 a. albianelli et al. martini i.p. & sagri m. (1993) tectono-sedimentary characteristics of late miocene-quaternary extensional basins of the northern apennines, italy. earth-science reviews, 3344, 197-233. merla g., 1951 geologia dell ’appennino settentrionale. boll. soc. geol. it. 70, 95-382. monegatti p. & raffi s., 2001 taxonomic diversity and stratigraphic distribution of italian pliocene bivalves. palaeogeogr., palaeoclimat., palaeoecol., 116655, 171-193. napoleone g. & azzaroli a., 2002 a collection of fossil vertebrates from the upper valdarno (central italy) calibrated to span 220,000 years across the olduvai magnetic chron up to the beginning of the quaternary. riv. it. paleont. strat., 110088, 479-492 napoleone, g. & ripepe, m., 1989 cyclic geomagnetic changes in mid-cretaceous rhythmites, italy. terra nova, 11, 437-442. napoleone g., albianelli a., azzaroli a. & mazzini m. (2001) the poggio rosso locality calibrated to the end pliocene and its significance for dating the late villafranchian faunas of the upper valdarno, central italy. riv. it. paleont. strat., 110077: 287-296. napoleone g., albianelli a., azzaroli a., bertini a., magi m. & mazzini m., 2003a calibration of the upper valdarno basin to the plio-pleistocene for correlating the apennine continental sequences. il qaternario, 1166(1bis), 159-195. napoleone g., albianelli a. & fischer a.g. 2003b magnetic susceptibility cycles in lacustrine deposits of northern apennines. am. ass. petr. geol., sepm special publ. (in press) nesti f., 1811 sopra alcune ossa fossil i di rinoceronte. tip. piatti, firenze, 24 pp. nesti f., 1825 – sulla nuova specie di elefante fossile del valdarno. tip. nistri, pisa, 23 pp. pareto m., 1865 sur les subdivisions que l'on pourrait etablir dans les terrains tertiaires de l'appennin septentrional. bull soc. géol. france, 2222, 210-277. raffi s., rio d., sprovieri r., valleri g., monegatti p., raffi i. & barrier p., 1989 new stratigraphic data on the piacenzian stratotype. boll. soc. geol. it., 110088, 183-196. rio d., sprovieri r. & di stefano e., 1994 the gelasian stage: a proposal of a new chronostratigraphic unit of the pliocene series. riv. it. paleontol. strat., 110000, 103-124. rio d., channell j.e.t., bertoldi r., poli m.s., vergerio p.p., raffi i., sprovieri r. & thunell r.c. (1997) – pliocene sapropels in the northern adriatic area; chronology and paleoenvironmental significance. palaeogeogr., palaeoclimat., palaeoecol., 113355, 125. shackleton n.j., 1995 new data on the evolution of climatic variability. in: vrba e.s., denton g.h., partridge t.c. and burckle l.s., eds.: palaeoclimate and evolution, with emphasis on human origins, 311-318. yale university press. shackleton n.j., backman j., zimmerman h., kent d.v., hall m.a., roberts d.g., schnitker d., baldauf j.g., despraisries a., homrighausen r., huddlestun p., keene j.b., kaltenback a.j., krumsiek k.a.o., morton a.c., murray j.w., & westberg-smith j., 1984 oxygen isotope calibration of the onset of the ice-rafting and history of glaciation in the north atlantic region. nature, 330077, 620-623. sorbini l., 1988 – biogeography and climatology of pliocene and messinian fossil fish of eastern central italy. boll. mus. civ. st. nat. verona, 1144, 1-85. tiedemann r., sarnthein m. & shackleton n.j., 1994 astronomic timescale for the pliocene atlantic delta 18o and dust flux records of ocean drilling program site 659. paleoceanography, 99, 619-638. tric e., laj c., jéhanno c., valet j.p., kissel c., mazaud a. & iaccarino s., 1991 high resolution record of the upper olduvai transition from po valley (italy) sediments: support for dipolar transition geometry? phys. earth planet. int., 6655,, 319336. van couvering j.a., 1995 setting pleistocene marine stages. geotimes, 4400, 10-11. van couvering, j.a., (ed.), 1997 the pleistocene boundary and the beginning of the quaternary. world and regional geology series, 9, 296 pp., cambridge univ. press. zagwijn w.j., 1992 the beginning of the ice age in europe and its major subdivisions. quatern. sci. rev., 1111, 583-591. zijderveld j.d.a., hilgen f.j., langereis c.g., verhallen p.j.j.m. & zachariasse w.j., (1991) integrated magnetostratigraphy and biostratigraphy of the upper pliocene-lower pleistocene from the monte singa and crotone areas in calabria, italy. earth planet. sci. lett., 110077, 697-714. 183magnetostratigraphic dating ... ms. ricevuto il 30 ottobre 2002 testo definitivo ricevuto l’1 luglio 2003 ms. received: october 30, 2002 final text received: july 1, 2003 imp.perilli& villafranchian deposits of the barga and castelnuovo garfagnana basins (tuscany, italy): lithostratigraphy and sedimentary features nicola perilli, alberto puccinelli, giovanni sarti & giacomo d’amato avanzi dipartimento di scienze della terra, università di pisa. via s. maria 53 – 56126 pisa – italy sarti@dst.unipi.it perilli@dst.unipi.it abstract: n. perilli et al., villafranchian deposits of the barga and castelnuovo garfagnana basins (tuscany, italy): lithostratigraphy and sedimentary features. (it issn 0394-3356, 2004). based on a refined mapping of the sedimentary wedges accumulated in the so-called barga and castelnuovo garfagnana basins and on a review of previous studies, the distinguished formations are here described. the “argille, sabbie e conglomerati di fornaci di barga” mainly consists of fine grained lithofacies with organic-rich horizons and coarse grained conglomerate. the “conglomerati di barga”, dominated by coarse grained lithofacies, is also characterized by silty to sandy interbeds, whilst organic-rich levels and paleosol horizons are rare. within this formation, the mt. alfonso member is also distinguished, albeit hardly mappable. sedimented in two separated tectonic depressions, connected by the “mt. perpoli high”, this succession has been interpreted in previous studies as ranging from cohesive sediment anabranching (“argille, sabbie e conglomerati di fornaci di barga”) to gravel bed-load braided river deposits (“conglomerati di barga”), roughly flowing from north to south. in the castelnuovo garfagnana area, the mt. alfonso member also records the development of a tributary river flowing from west to east and interpreted as a braided fluvial fan. in this frame, the “mt. perpoli high” acted as a sedimentary by-pass, since the beginning of the sedimentation. riassunto: n. perilli et al., i depositi villafranchiani dei bacini di barga e castelnuovo garfagnana (toscana, italia): litostratigrafia e caratteristiche sedimentarie. (it issn 0394-3356, 2004). sulla base di rilevamenti geologici di dettaglio effettuati nei depositi villafranchiani dei bacini di barga e castelnuovo garfagnana e di una revisione della letteratura, vengono definite le caratteristiche litostratigrafiche delle due formazioni riconosciute. la formazione delle “argille, sabbie e conglomerati di fornaci di barga” giace in discordanza sul substrato costituito da unità toscane metamorfiche (nucleo metamorfico apuano) e non metamorfiche (falda toscana) e, subordinatamente, da unità liguri e subliguri (unità ottone e unità canetolo); essa è caratterizzata prevalentemente da litofacies fini, con livelli di accumulo organico e di orizzonti pedogenetici e intercalazioni di conglomerati. la formazione dei “conglomerati di barga” è invece costituita da litofacies conglomeratiche, con sporadiche intercalazioni siltoso-sabbiose, a cui talvolta si associano paleosuoli e rari livelli di accumulo organico. all’interno di questa formazione, è stato distinto nell’area di castelnuovo garfagnana il membro di m. alfonso, costituito da conglomerati grossolani eterometrici. la formazione dei “conglomerati di barga” giace in possibile discordanza sulle “argille, sabbie e conglomerati di fornaci di barga”, anche se le cattive condizioni di affioramento non permettono di escludere a priori un possibile passaggio stratigrafico. le due formazioni vengono attribuite a due sistemi fluviali riferibili rispettivamente a un cohesive sediment anabranching river (“argille, sabbie e conglomerati di fornaci di barga”) e a un gravel bed-load braided river (“conglomerati di barga”), ambedue ad andamento circa nord–sud. il membro di m. alfonso registrerebbe invece la deposizione, nel bacino di castelnuovo garfagnana, di un sistema tributario attribuibile ad un braided fluvial fan a decorso circa ovest-est e alimentato dalle alpi apuane. in questo quadro, la soglia di monte perpoli avrebbe agito come by-pass sedimentario fin dall’inizio della deposizione villafranchiana. keywords: lithostratigraphy, continental deposits, villafranchian, tuscany, italy. parole chiave: litostratigrafia, depositi continentali, villafranchiano, toscana, italia. il quaternario italian journal of quaternary sciences 17(2/1), 2004, 313-322 1. introduction since the 19th century, the villafranchian succession cropping out in the barga and castelnuovo garfagnana tectonic depressions (tuscany) was investigated due to its fossil record, mainly represented by vegetable and mammal remains. the paleontological data increased as a consequence of the lignite and clay mining, that ended during the first and last decades of the 20th century, respectively. on the basis of few paleontological studies and limited number of vertebrate remains (de stefani, 1887 and 1889; ugolini, 1902; zaccagna, 1932 and masini, 1936), the villafranchian age of this succession is accepted. the main lithological features of these deposits have been described, among the others, by nardi (1961) and calistri (1974), and mapped at 1:10,000 scale by nardi et al. (1986 and 1987). unfortunately, these papers were not supported by detailed lithostratigraphic and sedimentological studies. nevertheless, based on the significant lignite contents of the fine grained basal sediments and the dominant coarse grained overlying deposits, the whole succession was interpreted as a fluvial-lacustrine cycle. recently, lithostratigraphy and facies analysis of these deposits were investigated by puccinelli et al. (in press, a) and landi et al. (2002-2003), respectively. on the basis of these studies, the main lithostratigraphic and sedimentary features of the villafranchian formations, discontinuously exposed in the barga and castelnuovo garfagnana areas, will be described in this paper. a similar succession, dividable in two formations, crops out north-westward in the aulla-olivola and pontremoli tectonic depressions (bertoldi, 1997 and 314 n. perilli et al. bernini et al., 1990). mainly consisting of fine grained lithofacies with medium to thick coarse grained interbeddings, the “argille, sabbie e conglomerati di aulla” (puccinelli et al., in press, b) is characterized by a variable amount of centimetric to decimetric lignite fragments and organic-rich horizons. it is overlain by the coarse grained “conglomerati di olivola” (puccinelli et al., in press, b), characterized by subordinate fine grained interbeddings. 2. geological setting the investigated area (fig. 1) is one of the continental intermontane tectonic depressions, that opened as a consequence of the counter-clockwise migration of the chain-foredeep-foreland system and of the extension of the northern apenninic tyrrhenian margin (meletti et al., 1995 and references therein) during the late ruscinian/early villafranchian time interval (bernini et al., 1990; bertoldi, 1995 and 1997). roughly comprised between the apuan alps and the apenninic watershed, the studied area includes two tectonic depressions, 5 km wide and 10 (barga) to 15 km (castelnuovo garfagnana) long, separated by the so-called “mt. perpoli high” (soglia di monte perpoli of puccinelli, 1987). these depressions are related to the movement of tectonic blocks collapsed and rotated along antithetical faults and interpreted as half-graben, with the master faults plunging towards the tyrrhenian border (martini & sagri, 1973; eva et al., 1978). the villafranchian succession laid down in the barga and castelnuovo garfagnana depressions unconformably overlies sedimentary successions of the apennine thrustand-fold belt, here represented by the falda toscana (mainly with the macigno formation), canetolo and ottone units. along the western sides of both depressions, the falda toscana in turn tectonically overlies the methamorphic core complex of the apuan alps. 3. previous studies and inferred age the sedimentary succession, cropping out in the barga and castelnuovo garfagnana areas, was investigated entirely by few authors. among them, de stefani (1887 and 1889), zaccagna (1917 and 1932), ugolini (1902), masini (1932 and 1936), tongiorgi & trevisan (1953), azzaroli (1955), nardi (1961) and calistri (1974) focused on stratigraphy, even if only this latter studied the entire villafranchian sedimentary succession. the papers of bartolini & bortolotti (1971), nardi (1961 and 1965), nardi et al. (1986 and 1987), d’amato avanzi & puccinelli (1988), puccinelli (1987), dallan et al. (1991) and moretti (1990) mainly deal with neotectonics and/or landslide hazard. fig. 1 tectonic sketch of the northern apennines and location of the main intermontane tectonic depressions nearby the study area (within the square). schema strutturale dell’appennino settentrionale con la localizzazione delle principali depressioni tettoniche limitrofe all’area di studio (nel riquadro). 315villafranchian deposits of the barga ... 4. lithostratigraphy and sedimentary features of the mapped formations as it is well known, the continental successions cropping out in the intermontane, post-collisional basins are usually badly exposed, due to both the large diffusion of the anthropic activities (e.g. agriculture, urbanization) and vegetation cover. consequently, the vertical and/or lateral outcrop extension is often limited, and the geometric and stratigraphic relationships between formations overshadowed. however, based on some well exposed sections, the entire succession has been rather well reconstructed. in the study areas, most significant sections are located in the barga area, where the mapped formations and the boundary between them are also well exposed. according to previous papers (nardi et al., 1986 and 1987; dallan et al., 1991), in the investigated area two formations have been recognized, and named by puccinell i et al. ( in press, a): “argille, sabbie and conglomerati di fornaci di barga” (afb) and “conglomerati di barga” (plb). in the castelnuovo garfagnana area, within plb, the mt. alfonso member is distinguishable. the extension of both formations (afb+plb) is represented in fig. 2. 4.1. argille, sabbie e conglomerati di fornaci di barga (puccinelli et al., in press, a) synonymies argille azzurre lignitifere e sabbie ocracee (nardi, 1961) argille di fornaci di barga pro parte (calistri, 1974) sabbie e argille lignitifere (nardi et al., 1986) argille e sabbie lignitifere (nardi et al., 1987) formazione di fornaci di barga (catanzariti et al., 2002) lithostratigraphic unit 1 (landi et al., 2002-2003) significant outcrops (see tab. 2) barga: rio secco, fornaci di barga, t. loppora, rio zanesi, rio cavo, t. giuvicchia, rio val di lago, le palmente and corsonna. castelnuovo garfagnana: rio la fossa, rio dezza, bamborino, rio valardino, la bottegaccia, villa collemandina, gamberone, antisciana and belvedere. tab. 1 list of vertebrate fossils remains from the “argille, sabbie e conglomerati di fornaci di barga” and “conglomerati di barga” formations. elenco dei resti dei vertebrati fossili provenienti dalle formazioni delle “argille, sabbie e conglomerati di fornaci di barga” e dei “conglomerati di barga”. authors localities fossil remains formations de stefani (1889) barga equus stenonis conglomerati di barga meneghini (1880) ghivizzano tapirus hystrix de stefani (1889) fornaci di barga rhinoceros etruscus rhinoceros etruscus sus arvernensis cervus sp. de stefani (1889) t. loppora felis cfr. isdiorensis meganthereon nestii histrix sp. tapirus sp. mastodon arvernensis ugolini (1902) fornaci di barga tapirus arvernensis cervus pardinensis masini (1936) fornaci di barga mastodon arvernensis emys sp. tapirus sp. la fossa sus sp. felis cfr. isdiorensis cervus sp. mastodon arvernensis de stefani (1887) custia mastodon arvernensis cervus sp. fornaci del ponte mastodon arvernensis castiglione tapirus sp. machiarodus eultridens fornaci del bianchi tapirus sp. sus arvernensis ugolini (1902) t. loppora tapirus arvernensis cervus pardinensis masini (1932) mastodon arvernensis a rg ill e, s ab b ie e c o ng lo m er at i d i f o rn ac i d i b ar g a unfortunately, the paleontological data as well as the age-significant fossil remains are scarce (tab. 1). however, the mammal fragments and the presence (landi et al . 2002-2003) of some molluscs (laminifera villafranchiana, prososthenia paulae, theodoxus cf. groyanus) and characean species (nitellopsis cf. megarensis carnevale et al., 2003) point to (according to azzaroli, 1977 and de giuli & masini, 1983) a lower-middle villafranchian age for the “argille, sabbie e conglomerati di fornaci di barga” and allow to assign the overlying “conglomerati di barga” to late villafranchian. 316 fig. 2 schematic geological map of the barga and castelnuovo depressions and nearby areas, based on the geological map at 1:50,000 sheet 250 castelnuovo garfagnana (puccinelli et al., in press, a) and on some geological maps at 1:10,000 scale (nardi et al., 1986 and 1987; dallan et al., 1991). carta geologica schematica dei bacini di castelnuovo garfagnana e barga e delle aree limitrofe, basata sulla carta geologica a scala 1:50.000 – foglio 250 castelnuovo garfagnana (puccinelli et al., in press, a) e su alcune carte geologiche a scala 1:10.000 (nardi et al., 1986 and 1987; dallan et al., 1991). n. perilli et al. 317 afb mainly consists of fine (clayey to sandy) grained lithofacies interbedded by medium to coarse conglomerate (from channel to wedge or sheetlike shaped), that sometimes can be dominant. the formation is also localities member (mb.) lithofacies (lt.) formations barga area t. loppora lenticular-shaped conglomerate (lt.) channel-shaped conglomerate (lt.) rio latrani sheet-like conglomerate (lt.) rio zanesi sheet-like conglomerate (lt.) corsonna fine grained (lt.) & channel-shaped conglomerate (lt.) le palmente lenticular-shaped conglomerate (lt.) & sandy (lt.) casa volpaia fine grained (lt.) and organic-rich horizons & channel-shaped conglomerate (lt.) pieve di loppia-barga road lenticular-shaped conglomerate (lt.) & sandy (lt.) barga lenticular-shaped conglomerate (lt.) & sandy (lt.) castelnuovo g. area rio dezza mt. alfonso (mb.). poorly sorted conglomerate il colle mt. alfonso (mb.). poorly sorted conglomerate mt. alfonso mt. alfonso (mb.). poorly sorted conglomerate s. lucia lenticular-shaped conglomerate (lt.) & sandy (lt.) castegni lenticular-shaped conglomerate (lt.) & sandy (lt.) soffiana sand and silty (lt.) & rare organic-rich horizons bamborino lenticular-shaped conglomerate (lt.) & sandy (lt.) liana sandy (lt.) & lenticular shaped conglomerate (lt.) barga area rio secco fine grained (lt.) & channel-shaped conglomerate (lt.) cava fornaci fine grained (lt.) t. loppora channel-shaped conglomerate (lt.) & fine grained (lt.) le palmente fine grained (lt.) rio cavo fine grained (lt.) & channel-shaped conglomerate (lt.) rio zanesi fine grained (lt.) & channel-shaped conglomerate (lt.) rio val di lago fine grained (lt.) and organic-rich horizons & channel-shaped conglomerate (lt.) corsonna fine grained (lt.) & channel-shaped conglomerate (lt.) rio della giuvicchia fine grained (lt.) and organic-rich horizons & channel-shaped conglomerate (lt.) casa volpaia fine grained (lt.) & channel-shaped conglomerate (lt.) castelnuovo g. area rio dezza fine grained (lt.) & channel-shaped conglomerate (lt.) rio la fossa fine grained (lt.) and organic-rich horizons & channel-shaped conglomerate (lt.) collemandina fine grained (lt.) & sandy (lt.) bamborino fine grained (lt.) la bottegaccia fine grained (lt.) & organic-rich horizons gamberone fine grained (lt.), organic-rich horizons & sandy (lt.) antisciana fine grained (lt.) & channel-shaped conglomerate (lt.) belvedere fine grained (lt.) & channel-shaped conglomerate (lt.) rio valardino fine grained (lt.) & channel-shaped conglomerate (lt.) c o ng lo m er at i d i b ar g a a rg ill e, s ab b ie e c o ng lo m er at i d i f o rn ac i d i b ar g a tab. 2 most significant outcrops in the barga and castelnuovo garfagnana depressions of the “argille, sabbie e conglomerati di fornaci di barga” and “conglomerati di barga” formations. exposed lithofacies are also synthetically described. affioramenti maggiormente significativi nelle aree di barga e castelnuovo garfagnana delle formazioni delle “argille, sabbie e conglomerati di fornaci di barga” e dei “conglomerati di barga”. sono anche descritte in modo sintetico le litofacies caratteristiche affioranti. characterized by a variable amount of centimetric to decimetric lignite fragments, that in places are abundant and concentrated in organic-rich horizons (fig. 3a). the fine grained deposits, ranging from 0.5 to 3-7 villafranchian deposits of the barga ... 318 m in thickness, are usually organized in centimetric to decimetric rhythmical alternance of grey-dark, grey to bluish or violet clay to silty-clay and yellowish silty or sandy beds, with horizontal to cross or through lamination, in places well evidenced by small lignite fragments. they can be associated with 0.5 to 3.5 m thick massive to horizontal laminated organic-rich clay or silty to sandy interbeddings, that somewhere show soft deformation structures. the organic-rich levels, more abundant in the lower portion of the formation, contain scattered lignite fragments, that can concentrate in 20 to 40 cm thick horizons, with limited (10-15 m) lateral extent. the sandy intervals, usually 10-20 cm thick and up to 1.5-2 m wide, can be up to 1.5 m thick and 10 m wide. in the thickest sandy levels, thin to medium thick lens-shaped conglomerate can be present. at different levels, and mainly within the clay and silty-clay intervals centimetric to decimetric (20-30 cm), dark grey paleosols containing land fossils (landi et al., 2002-2003) are present. unfortunately, the lateral extent of these horizons is limited and their correlation unreliable. the scarce fossil remains of the fine grained lithofacies include ostracods and gastropods, along with extremely rare teeth of fish and charophites oogonia (genus and species names in landi et al., 20022003). fragments of leaves and chunks of trees are also present and in few places the latter are still observable in life position (rio dezza). the isolated channel-shaped, clast-supported polymictic conglomerate, from grey/dark grey to brownish, consist of sub-rounded to well rounded clasts, in places imbricated. this medium to coarse grained massive and well sorted conglomerate shows a low percentage of silt to fine matrix, not always present. this deposit, with weak to strong erosive basal surface and limited (3-5 to 15-20 m) lateral extent, ranges from 1 to 3 m in thickness. the coarse grained lithofacies can also be represented by an alternance of clast-supported, wedgeto sheet-like conglomerate or sandy conglomerate, and medium to coarse sand. this conglomerate, from 1 to 3 m thick and up to 20-40 m wide, lacks any evidence of basal erosive surface. the pebbles and cobbles range from sub-angular to sub-rounded/rounded. the medium to coarse sandy matrix is present in variable amount, that can vary in percentage at metric scale. the sandy interbeds range from massive to cross laminated. in both types of conglomerate, the clasts are mainly represented by unmetamorphosed lithotypes, with the arenaceous clasts (referable to the macigno fm.) slightly more abundant than the carbonatic ones. in places, the arenaceous clasts can be dominant. the metamorphic (landi et al. 2002-2003) ones are more abundant in the barga (up to 15-20%) than in the castelnuovo garfagnana area, where they are extremely rare (below 1%). scattered along the apenninic border, afb is interbedded, at different levels, with medium/coarse to very coarse grained, monomictic, massive conglomerate, mainly made of clasts referable to the macigno fm. (i.e. units 3 and 4 of landi et al., 2002-2003). this unsorted to poorly sorted, matrixto clast-supported conglomerate is nicely exposed at colle buvicchia and mologno. it chiefly consists of sub-angular to rounded cobbles and boulders, in places well imbricated. the medium to coarse sandy matrix is furnished by the macigno fm. weathering. ranging in thickness from few metres up to 100 m, such coarse clastic wedges (in places) can represent the entire villafranchian sedimentary record. according to landi et al. (2002-2003), the association of fine and coarse grained lithofacies with in situ accumulated organic matter (mainly represented by lignite) was sedimented in a braided fluvial system, referable to an anabranching organo-clastic substage (sensu nanson & knighton, 1996), f lowing from castelnuovo garfagnana to barga. it interfingers with the alluvial fan deposits (dominated by debris-flow processes), cropping out along the apenninic border (i.e. units 3 and 4 of landi et al., 2002-2003), and develops transversally to the tectonic depression axis. the thickest exposures range from 10-40 to 80 m in the barga area and from 10 to 30-40 m in the castelnuovo garfagnana area. the maximum thickness of this formation measured near castelnuovo garfagnana, including a drilled portion, can reach 200 m (de marco & caielli, 1995; cancelli et al., 2002). usually, the outcrops are not thicker than 10-30 m in barga as well as in castelnuovo garfagnana areas. the unconformable contact with the underlying formations is exposed in few localities, with bad exposure conditions and very limited lateral extent. along the eastern border of the barga depression, the macigno fm. is topped by the basal coarse grained and poorly sorted conglomeratic lithofacies of afb. in the boreholes drilled near villa collemandina, the substratum (represented by ligurian successions) has been reached below 90-100 m of afb. the afb/plb contact is frequently well exposed and characterized by an abrupt facies change, suggesting a possible disconformity surface. nevertheless, in some places (gallicano and barga areas) the heteropy between the two formations is not excluded. in fact, conglomeratic interbeddings are locally present in the uppermost part of afb; they are similar to those interbedded in the lowermost part of plb. in other areas, afb is topped by the erosive post villafranchian coarse grained terraced deposits. according to the quoted fossil remains, the lowermost portion of this formation could be assigned to the lower villafranchian, whilst its upper portion could reach the middle villafranchian. 4.2. conglomerati di barga (puccinelli et al., in press, a) synonymies ghiaie con prevalenza di rocce mesozoiche e metamorfiche (nardi, 1961) ciottoli e sabbie di loppia (calistri, 1974) conglomerati a ciottoli prevalentemente calcarei (nardi et al., 1986) ghiaie e conglomerati calcarei (nardi et al. 1987) conglomerati di barga (catanzariti et al., 2002) lithostratigraphic unit 2 (landi et al., 2002-2003) significant outcrops (see tab. 2) barga: t. loppora, rio latrani, rio zanesi, le palmente, pieve di loppia-barga road, barga and casa volpaia. castelnuovo garfagnana: bamborino, rio dezza, il colle, s. lucia, castagni, soffiana, mt. alfonso and liana. n. perilli et al. 319 fig. 3 main litholological features of the “argille, sabbie e conglomerati di fornaci di barga” fm. (a) and of the “conglomerati di barga” fm. (b). colonne stratigrafiche mostranti le principali caratteristiche litologiche delle “argille, sabbie e conglomerati di fornaci di barga” (a) e dei “conglomerati di barga” (b). villafranchian deposits of the barga ... plb is characterized by the dominance of medium to coarse (from pebbles to cobbles) grained lithofacies, whilst sandy to silty-clayey levels, with very rare paleosols, are subordinate. though texture, sedimentary structures and shapes of the conglomerate can change even at metric scale, two end-members can be described: one shows sheet-like geometry and significant presence of sand interbeddings, the other is lens-shaped and characterized by erosive basal surface and small amount of matrix (fig. 3b). the sheet-like, clast-supported conglomerate, with massive to crude bedding is interbedded with thin (2-3 to 5-10 cm), massive to horizontally stratified, lenticular yellowish sand. these coarse grained intervals, with very rare sedimentary structures, mainly consist of poorly to moderately sorted conglomerate, with well rounded pebbles and cobbles, rarely imbricated and with a variable amount of sandy-silty to silty matrix; the matrix percentage may change even within the same interval. this disorganized to poorly organized conglomerate, frequently ranging in thickness from 0.5 to 1 m, can be up to 3 m thick and 20-30 m wide. the lens-shaped, medium to coarse conglomerate, is chiefly composed of well sorted clasts and small percentage of silty to sandy matrix. the sub-rounded to rounded clasts are frequently imbricated and the matrix can be, in places, either absent or significantly present. this conglomerate, sometimes channellized, shows weakly erosive basal surface and planar to through cross stratification. ranging in thickness from 0.5 to 3 m, it can be up to 20-30 m wide. within this conglomerate, thin to thick (10-50 cm) interbeddings of massive, brownish to brown-reddish sand, with small lateral extension, are present. in both types of conglomerate, the clasts are chiefly represented by non-metamorphic or metamorphic carbonatic lithotypes; whilst sandstone (referable to the macigno fm.) is subordinate. within the coarse grained lithofacies, interbeddings of silt and fine to medium grained yellowish to reddish sand, up to 1 m thick, are present. more abundant in the sheet-like conglomerate and sometimes bioturbated, silt and sand frequently show through and planar cross-bedding. in places, grey to dark-grey, millimetric to centimetric lenses of clay evidence the sedimentary structures of these fine grained interbeddings. plb is also characterized by the occurrence of centimetric to decimetric rhythmical interbeddings of grey clay or silty-clay to sandy beds, with horizontal to cross or through lamination, similar to those described for the underlying formation. these fine grained lithofacies, usually ranging from few decimetres to 1-2 m (rio latrani, rio sartoiani, t. giuvicchia and t. corsonna), are up to 20 m thick at casa volpaia. in the silty-sandy or sandy beds micro and macro vegetable remains may concentrate and at different levels, centimetric to decimetric dark grey or blackish paleosols are also present. in all quoted localities, the heteropic transitions with the coarse grained deposits are visible. as reported by landi et al. (2002-2003), the described lithofacies association is dominated by conglomerate together with sandy lenses and centimetric to decimetric alternance of fine grained deposits (characterized by organic-rich horizons and paleosols). this association is referable to a gravel bed-load braided river system, flowing from ne to sw (i.e. from castelnuovo garfagnana to barga). as described for afb, along the apenninic border, also plb, interfingers with coarse grained lithofacies (unit 3 of landi et al., 2002-2003), characterized by sub-angular to rounded (the boulders) clasts, chiefly consisting of sandstone (referable to the macigno fm.), and interpreted as coalescent alluvial fan deposits (dominated by debris-flow processes) developed transversally to the tectonic depression axis. plb is superbly exposed along the oriental side of the serchio valley, and ranges in thickness from 70 (gallicano) to 170 m (barga). the better exposures are located between loppia and barga and in the villa collemandina area. usually, the outcrops can be 20-40 m thick and from 100 to 200 m wide. the clearly erosive contact between the conglomerati di fornaci di barga and the post villafranchian coarse grained terraced deposits is frequently well exposed. according to the few listed paleontological remains, this formation could be assigned to the middle to late villafranchian. west of the castelnuovo garfagnana area, plb is represented by medium to coarse clast-supported conglomerati of mt. alfonso member (unit 5 of landi et al., 2002-2003). showing a tabular geometry with thickness ranging from 0.5 to 3 m, these deposits can vary even in a short distance from disorganized to organized sedimentary body. the poorly sorted clasts, with a diameter up to 50 cm, in places imbricated, are mainly composed of carbonate, whilst the presence of sandstone is subordinate, though sometimes it can be significantly present. the 100 (westard) to 40 m (eastward) thick mt. alfonso member is interpreted as a braided fluvial fan, supplied by the apuan alps and developed transversally to the basin axis (landi et al. 2002-2003). 5. conclusive remarks on the basis of the main lithostratigraphic and sedimentological features of the described villafranchian succession, the following points should be emphasized. in the barga and castelnuovo garfagnana areas, afb and plb are characterized by distinctive lithofacies associations, and the boundary between the two formations is quite easily recognizable. within afb, clay and conglomerate are subordinate and the formalized name points out the wide lithological spectrum, that characterizes this formation. nevertheless, lateral and vertical variations between fine grained and coarse grained lithofacies are distinguishable at outcrop scale, but hardly mappable, due to their limited thickness and lateral extent. the clayey intervals of afb are more widespread and thicker in the castelnuovo garfagnana than in the barga depression, whilst sandy intervals are thicker and wider in the barga than in the castelnuovo garfagnana area. thin to very thin and well stratified, clayey-silty to sandy laminated (varve-like) intervals are peculiar of the castelnuovo garfagnana area. the organic-rich horizons within afb are relatively more abundant in the lower portion of the formation. they are usually represented by centimetric to decimetric horizons within the fine grained portions. the largest fragments of lignite and the chunks of trees 320 n. perilli et al. are scattered throughout the formation, and some of these latter are sometimes still in life position. the lignite banks, including the mined ones, are thicker and more continuous than those cropping out or mined in the barga area. in afb the coarse grained intervals are mainly represented by channelized conglomerate interbedded by clayey-silty or sandy dominant lithofacies. likewise, the sheetlike conglomerate (almost absent in the castelnuovo garfagnana area), present in the lower portion of the formation, is associated with clayeysilty or sandy lithofacies. in spite of the lateral and vertical lithological variation of the different lithofacies, the dominance of the coarse grained conglomerate allows the easy mapping of the plb, also characterized by sandy interbeddings. silty-clayey to sandy fine grained lithofacies (with thin organic-rich horizons similar to those present in afb), with reduced thickness as well as lateral extent, are clearly in heteropy to the conglomerate. also in the castelnuovo garfagnana area these lithofacies (including organic-rich horizons) are very limited in thickness and lateral extension. lignite fragments or other biogenic remains, as well as paleosols, are extremely rare and scattered within plb. indeed, large lignite fragments can be present within the coarse grained lithofacies, whilst millimetric to centimetric lignite flakes are relatively more frequent within the finest grained lithofacies. in the castelnuovo garfagnana depression, within the plb, the mt. alfonso member is distinguishable. mainly consisting of polymictic, poorly sorted medium to coarse conglomerate and subordinate coarse grained sand, it can be correlated with the conglomerate cropping out in the gallicano area (d’amato avanzi & puccinelli, 1988) and mapped within the plb. in spite of similar lithologies present in both formations, the lithofacies assemblages point out the superposition of gravel bed-load braided river deposits (plb) on cohesive sediment anabranching river deposits (afb). both successions interfinger with the alluvial fan conglomerate, that in places can represent the entire villafranchian succession. the abrupt facies change between these two clastic successions can be interpreted as a disconformity surface (landi et al., 2002-2003). unfortunately, it is neither supported by paleontological data nor confirmed by other field evidence. however, the conglomeratic lithofacies interbedded within the afb shows neither a polarity towards the top of the formation nor significant similarities with the coarse grained lithofacies of the plb. on the other hand, the erosive contact between afb and plb can be also interpreted as stratigraphic, because erosive surfaces are frequent within this type of deposits (from anabranching to gravel bed-load braided). moreover, the presence of channellized conglomeratic lenses within the uppermost part of the afb, similar to those present in the overlying lowermost part of plb, can support (at least in some places) a quite sharp but transitional boundary between afb and plb (puccinelli et al., in press, a). in summary, though the villafranchian clastic wedges sedimented in two distinct tectonic depressions, connected by the sedimentary by-pass (landi et al., 2002-2003) of the “mt. perpoli high”, active since the beginning of the villafranchian deposition, the lithofacies associations characterizing afb as well as plb are quite similar in both areas. furthermore, the boundary between afb and plb shows the same features in both depressions, even if the field evidence is not helpful to choose between the existence of a disconformity or a stratigraphic transition between afb and plb. although the correlation between continental clastic successions, not supported by sedimentological analysis and paleontological data is difficult, in our opinion the afb and plb can be correlated with the “argille, sabbie e conglomerati di aulla” and the “conglomerati di olivola”, respectively (puccinelli et al., in press, b). both crop out north-westward in the magra valley (aulla-olivola and pontremoli tectonic depressions) and show strong affinities with afb and plb. the “argille, sabbie e conglomerati di aulla” consists of fine grained lithofacies characterized by a variable amount of centimetric to decimetric lignite fragments and organic-rich horizons, with medium to thick coarse grained sandy conglomeratic interbeddings. the overlying “conglomerati di olivola” is represented by coarse grained conglomerate and subordinate fine grained interbeddings. acknowledgements we are grateful to dr. daniele nannini for his collaboration in realizing figures and synthesizing cartographic data. we are also grateful to an anonymous referee for his useful suggestions. references azzaroli a. 1955 la struttura della valle del serchio nei dintorni di castelnuovo di garfagnana. boll. soc. geol. it., 74, 73-78. azzaroli a., 1977 the villafranchian stage in italy and the plio-pleistocene boundary. giorn. geol., 41 (2), 61-79. bartolini c. & bortolotti v., 1971 carta dei depositi continentali dell’alta garfagnana (scala 1:10.000). mem. soc. geol. it., 10 (3). bernini m., boccaletti m., moratti g., papani g., sani f. & torelli l., 1990 episodi compressivi neogeniciquaternari nell’area estensionale tirrenica nordorientale. dati in mare e a terra. mem. soc. geol. it., 44, 577-589. bertoldi r., 1995 palinostratigrafia dei bacini intermontani dell’appennino nord-occidentale. il quat., 8 (1), 61-70. bertoldi r., 1997 lineamenti palinostratigrafici di depositi continentali del pliocene-pleistocene inferiore iniziale dell’italia nord-occidentale. boll. soc. paleont. it., 36 (1-2), 63-73. calistri m., 1974 il pliocene fluvio-lacustre della conca di barga. mem. soc. geol. it., 13, 1-21. cancelli a., d'amato avanzi g., pochini a. & puccinelli a., 2002 caratterizzazione geologica e litologico-tecnica delle piane del serchio e della turrite secca in prossimità di castelnuovo di garfagnana (lucca). riv. it. geot., 3, 17-32. 321villafranchian deposits of the barga ... carnevale g., ravani s. & sarti g., 2003 preliminary biostratigraphy data from castelnuovo garfagnana basin (lucca, tuscany). geoitalia 2003, 4° forum italiano di scienze della terra, 109-110. catanzariti r., ottria g. & cerrina feroni a., 2002 tavole stratigrafiche della carta geologico-strutturale dell’appennino emiliano-romagnolo in scala 1:250.000. selca firenze. dallan l., nardi r., puccinelli a., d’amato avanzi g. & trivellini m., 1991 valutazione del rischio da frana in garfagnana e nella media valle del serchio (lucca). 3) : carta geologica e carta della franosità degli elementi “sillano”, “corfino”, “fosciandora” e “coreglia” (scala 1:10.000). boll. soc. geol. it., 110, 245-272. d'amato avanzi g. & puccinelli a., 1988 la valle villafranchiana della turrite di gallicano e le sue implicazioni neotettoniche. suppl. geogr. fis. dinam. quat. 1, 147-154. de giuli c. & masini f., 1983 a new element in the late villafranchian (tasso unit) faunas of italy: occurrence of ovibovini (bovidae, artiodactyla, mammalia) in the fauna of casa frata (upper valdarno, tuscany). boll. soc. paleontol. ital., 22, (3), 271-280. de marco r. & caielli e., 1995 valutazione sperimentale degli effetti di sito da dati sismici: castelnuovo di garfagnana. cnr-irrs, regione toscana, 29 pp. de stefani c., 1887 le ligniti del bacino di castelnuovo di garfagnana. boll. r. com. geol. it., 18, 212-236. de stefani c., 1889 il lago pliocenico e le ligniti nella valle del serchio; rapporto del prof. c. de stefani al ministero di agricoltura, industria e commercio. boll. r. com. geol. it., 20, 30-352. eva c., giglia g., graziano f. & merlanti f., 1978 seismicity and its relation with surface structures in the north western apennines. boll. geofis. teor. appl., 20, 7-9. landi e., ravani s., sarti g. & sodini m., 2002-2003 the villafranchian deposits of the castelnuovo garfagnana and the barga basins (lucca, tuscany, italy): facies analysis and paleoenvironmental reconstruction. atti soc. tosc. sci. nat., mem. [ser. a], 108, 81-93. martini i.p. & sagri m., 1973 tectono-sedimentary characteristics of late miocene-quaternary extensional basins of northern apennines, italy. earth science rev., 34, 197-233. masini r., 1932 sull’interrimento del lago pliocenico di barga nella vallata del serchio. boll. soc. geol. it., 52, 305-330. masini r., 1936 i due laghi pliocenici di barga e di castelnuovo della garfagnana e i loro rapporti con le direttrici di frattura e le aree sismiche. atti accad. sci. lett. art. lucchese, 4, 3-55. meletti c., patacca e. & scandone p., 1995 il sistema compressione-distensione in appennino. in g. bonari, b. de vito, p. gasparini, a. vallario (eds): “cinquanta anni di attività didattica del prof. felice ippolito”, liguori ed., napoli, 1995, 361-370. meneghini g., 1880 resti di tapiro e d’istrice nella lignite di ghivizzano. atti soc. tosc. sc. nat., proc. verb., 2, 23. moretti a., 1990 evoluzione tettonica della toscana settentrionale tra il pliocene e l’olocene. boll. soc. geol. it., 111, 459-492. nanson g.c. & knighton a.d., 1996 anabranching rivers: their cause, character and classification. earth surf. proc. land. 21, 217-239. nardi r., 1961 geologia della zona tra la pania della croce, gallicano e castelnuovo garfagnana (alpi apuane). boll. soc. geol. it., 80 (2), 257-334. nardi r., 1965 schema geologico dell’appennino tosco-emiliano tra il m. cusna e il m. cimone e considerazioni sulle unità tettoniche dell’appennino. boll. soc. geol. it., 84 (5), 35-92. nardi r., pochini a., puccinelli a., d’amato avanzi g. & trivellini m., 1986 valutazione del rischio da frana in garfagnana e nella media valle del serchio (lucca). 1) : carta geologica e carta della franosità degli elementi “gragnana”, “piazza al serchio”, “casciana” e “ceserana” (scala 1:10.000). boll. soc. geol. it., 104 (1985), 585-599. nardi r., puccinelli a., d’amato avanzi g. & trivellini m., 1987 valutazione del rischio da frana in garfagnana e nella media valle del serchio (lucca). 2): carta geologica e carta della franosità degli elementi “sil l ico”, “castelnuovo garfagnana”, “cascio”, “castelvecchio pascoli”, “gall icano”, “barga”, “fornaci di barga” e “ghivizzano” (scala 1:10.000). boll. soc. geol. it., 106, 819-832. puccinelli a., 1987 un esempio di tettonica recente nella val di serchio: i l sollevamento di monteperpoli. atti soc. tosc. sci. nat., mem. [ser. a], 94, 105-117. puccinelli, a., d’amato avanzi, g. & perilli n., in press (a) carta geologica d’italia a scala 1:50.000 note illustrative del foglio 250 castelnuovo di garfagnana. puccinelli, a., d’amato avanzi, g. & perilli n., in press (b) carta geologica d’italia a scala 1:50.000 note illustrative del foglio 234 fivizzano. tongiorgi e. & trevisan l., 1953 excursion en garfagnana et aux alpes apouanes. iv congrès inqua, roma-pisa, tip. giard., pisa, 1-11. ugolini r.,1902 vertebrati fossili del bacino lignitifero di barga (val di serchio). atti soc. tosc. sc. nat., proc. verb., 13, 32-36. zaccagna, d.,1917 le ligniti di ghivizzano in val di serchio. roma, febbraio 1917. zaccagna, d.,1932 descrizione geologica delle alpi apuane. mem. descr. carta geol. it., 25, 440 pp. 322 ms. ricevuto il 21 maggio 2004 testo definitivo ricevuto il 12 ottobre 2004 ms. received: may 21, 2004 final text received: october 12, 2004 n. perilli et al. amq abs tagliasacchi et al palcom 161-164.pub available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 161 164 palaeoclimate changes in the afyon province, sw-turkey, during the middle-late pleistocene: signals from calcareous tufa pollen and stable isotope records ezher tagliasacchi 1, mine sezgül kayseri-özer 2 1 pamukkale university, geology engineering department, kınıklı, denizli, turkey 2 dokuz eylul university, institute of marine science and technology, haydar aliyev bul, i̇nciraltı-izmir, turkey corresponding author: e. tagliasacchi <egulbas@pau.edu.tr> abstract: the calcareous tufas of sarıkavak located in the northern part of ne-sw trending acıgöl graben in sw-turkey are investigated in detail. for this aim, various analyses (stable isotopes, u/th dating, palynology) have been carried out on samples obtained from both outcrops and drilling logs in and surrounding sarıkavak village. u/th dating shows that these carbonates precipitated from 400 ka up to 80 ka. preliminary pollen data, document climatic variability between mis 11 and mis 8 in the studied area. keywords: calcareous tufa, palynology, palaeoenvironment, palaeoclimate, afyon, sw-turkey 1. introduction terrestrial carbonates such as travertine and calcareous tufa are exposed in several depositional, climatic, and tectonic contexts throughout the world (chafetz & folk, 1984; pedley, 1990; ford & pedley, 1996; pentecost, 2005). their depositional, geochemical, isotopic and palynological signatures are very complex to interpret in terms of paleoenvironmental and palaeoclimatic changes (altunel & hancock, 1993; guo & riding, 1998; bertini et al., 2008; bertini et al., 2014; ricci et al., 2015; toker et al., 2015 and toker, 2017). the purpose of this study is to reveal the sedimentological and depositional processes as well as to approach the palaeoclimatic changes during the middlelate pleistocene in sarıkavak calcareous tufa located in afyon province, sw-turkey. 2. study area the acıgöl graben basin is located approximately 50 km northeast of denizli and southern afyon province in sw-turkey (fig. 1). it is an asymmetric graben, approximately 30 km long and 10 km wide, floored by the mesozoic-paleogene carbonate and ultramafic bedrocks (göktaş et al., 1989; şenel, 1997; konak & şenel, 2002). the upper miocene-pliocene deposits unconformably overlay molasse type deposits known as “çardak-dazkırı basin” and mainly consist of mudstonesandstone alternations and clay-rich limestone (göktaş et al., 1989; şenel, 1997; toker, 2009). the basin is bordered by ne-sw trending faults (i.e. the acıgöl fault in the south and the maymundağı fault in the north) which created a narrow corridor in which lake acıgöl developed during the pliocene (fig.1). the acıgöl graben basin started to form during the neotectonic period and deposits have been uplifted by activated older faults or newly generated younger faults (helvacı et al., 2013). travertine and calcareous tufa deposits overlay on the pliocene sediments and they are very well exposed in the örtülü and sarıkavak villages (fig. 1). 3. material and methods investigations on the sarıkavak calcareous tufa were divided into two steps: field work and laboratory analyses. during the field survey, we carried out facies description and samples collection from the non-marine carbonates and associated sediments. stable carbon and oxygen isotope measurements of the carbonates (sixty-three old tufa samples) for the palaeoenvironmental interpretation of these tufas were performed at the carbonate laboratory of stable isotopes, department of geoscience, university of arizona (usa). carbon and oxygen isotope analyses of bulk carbonate samples were carried out using the continuous flow technique (spötl and vennemann, 2003). 13c/12c and 18o/16o ratios were determined in co2 gases liberated by phosphoric acid using a finnigan delta plus xp mass spectrometer (thermo fisher scientific, bath, uk). u-th disequilibrium analyses were accomplished in low primary porosity twenty-three tufa samples. these samples were analyzed at the geotop research center of the university of quebec (montreal, canada). palynological analyses were conducted in two different laboratories. eight samples from the sarıkavak nonmarine carbonates were analyzed at the laboratory of palynology of the university of florence, italy, and the rest of them was analyzed at the laboratory of palynology of the department of the institute of marine science and technology, i̇zmir, turkey. https://doi.org/10.26382/aiqua.2018.aiquaconference 4. results in the sarıkavak tufas, seven lithofacies were distinguished. they are characterized by the good occurrence of mosses -included bryophytes, and macrophytes. however also other tufa lithofacies are well expressed by the occurrence of phytoclastic, oncolitic, stromatolitic, intra and extra clasts and sapropelitic tufas. all facies represent fluvial and fluvio-palustrine depositional systems (toker, 2017). ostracods and gastropods are the most abundant faunal remains. palynological analyses showed that palaeosol levels are more enriched in palynomorphs than bulk carbonate deposits. pollen of gymnosperms and angiosperms plus nonpollen palynomorphs are scarcely observed in travertine samples, whereas they are abundant in palaeosol samples. palynoflora defined in the palaeosol level is especially characterized by herbaceous taxa (i.e. poaceae, asteraceae asteroideae, artemisia, asteraceae cichorioideae, polygonum persicaria, geraniaceae and chenopodiaceae) but also includes trees taxa (i.e. quercus, castanea, cedrus and other pinaceae). nonpollen palynomorphs and other organic material were also abundantly recorded (fig. 2). pollen and other palynomorphs were detected in the bulk carbonate deposits in the sarıkavak tufas between the mis 8 (291±28ka) and mis 11 (359±21ka). the mis 11 interval is characterized by gymnosperm and angiosperm pollen (pinaceae-pinus spp., cedrus, castanea, oleaceae and chenopodiaceae). the pollen assemblage of mis 10 especially includes abies, pinaceae-pinus spp., oleaceae, fagaceae-quercus evergreen type, as 162 tagliasacchi e., kayseri-özer m.s. fig. 1 location of the study area. the satellite photo shows the sarıkavak and surrounding areas in sw-turkey. 163 teraceae asteroideae, artemisia and chenopodiaceae. palynomorph association of mis 9 was dominated by pinaceae-pinus sp. (haploxylon and diploxylon types), cedrus, pterocarya, oleaceae, fagaceae-quercus evergreen type and artemisia. these changes in the palynomorph association could be related to the climatic changes in the mis periods. δ18o values are in the range −10.83‰ to −7.49‰ vpdb while δ13c values vary from −1.63‰ to +1.5‰ vpdb. u/th dating of the sarıkavak calcareous tufas yielded 474 ka, 333 ka, 291 ka, 188 ka and 80 ka. stable isotope pattern is apparently coherent with the palynological-derived palaeoenvironental reconstruction. 5. discussion and conclusion this study permitted identification of seven tufa lithofacies which represent fluvial to fluvio-palustrine depositional systems. according to radiometric dating, carbonate precipitation occurred continuously across consecutive interglacial (e.g. mis 11 and mis 9) and glacial periods (e.g. mis 10 and mis 8) (fig. 2). the presence of palaeosols land debris flow supports main changes in atmospheric and edaphic humidity. precipitation of terrestrial carbonates started again to the edge of the graben fault (which confined the acıgöl graben, as fluvial tufa deposits), along mis 5, till ca. 80 ka. according to the stable isotopic measurements, δ13c values are between ‰ -1.6 and +1.5 ‰ while those of δ18o are between ‰ -7.4 and ‰ -10.8. the changes of δ18o values could be related to the evaporation in the depositional environment, while the less negative δ13c values could be interpreted as surface water mixing with the co2 transported from deep hydro thermal waters and decreasing the c isotope values. the spores and pollen records give some preliminary clues about the palaeovegetational and palaeoclimate of the region which is especially useful for a better interpretation of the δ13c stable isotopic fluctuations (i.e. arid vs less arid/humid conditions). acknowledgement this study is financially supported by tubi̇tak (the scientific and technological research council of turkey) (project no. 115y493) and pamukkale university scientific research project unit (project no. 2014hzl010). the authors warmly thank to reviewers for the helpful comments and suggestions. references arenas-abad c., vazquez-urbez m., pardo-tirapu g., sancho-marcen c. (2010) fluvial and associated carbonate deposits. in: carbonates in continental settings: facies, environments, and processes (eds a.m. alonso zarza and l.h. taner), dev. sedimentology, 61, 133-175. bertini a., minissale a., ricci m. (2008) use of quaternary travertines of central-southern italy as archives of paleoclimate, paleohydrology and neotectonics, il quaternario, 21 (1b), 99-112. bertini a., minissale a., ricci m. (2014) palynological approach in upper quaternary terrestrial carbonates of central italy: anything but a “mission impossible, sedimentology, 61, 200-220. chafetz h.s., folk r.l. (1984) travertines: depositional morphology and the bacterially constructed constituents. journal sedimentary petrology, 54, 1, 289 316. göktas f., çakmakoğlu a., tan e., sütçü y.f., sarıkaya h. (1989) çivrilçardak arasının jeolojisi. (the geology between çivril-çardak region). mineral research and exploration institute of turkey (mta), report no. 8701, pp. 109. (in turkish with english abstract) guo l., riding r. (1998) hot-spring travertine facies and sequences, late pleistocene rapolano terme, italy. sedimentology, 45, 163-180. helvacı c., alçiçek m.c., gündogan i., gemici ü. (2013) pollen and stable isotopes palaeoclimate record, afyon province fig. 2 palynomorph assemblage in the interval between mis 11 and mis 8. tectono sedimentary development and palaeoenvironmental changes in the acıgöl shallow perennial playa-lake basin, sw anatolia, turkey. turkish journal of earth sciences, 22, 173-190. konak n., şenel m. (2002) geological map of turkey in 1/500.000 scale: denizli sheet. mineral research and exploration institute of turkey (mta) publications. ricci m., bertini a., capezzuoli e., horvatinčić n., andrews j.e., fauquette s., fedi m. (2015) palynological investigation of a late quaternary calcareous tufa and travertine deposits: the case study of bagnoli in the valdelsa basin (tuscany, central italy). review of palaeobotany and palynology, 218, 184-197. spötl c., vennemann t.w. (2003) continuous-flow irms analysis of carbonate minerals. rapid communications in mass spectrometry, 17, 10041006. şenel m. (1997) geological maps of turkey in 1:100.000 scale: denizli k9 sheet. mineral research and exploration directorate of turkey, ankara, pp. 17. toker e. (2009) the investigation of tectonosedimentary evolution of the tertiary deposits in the north of acıgöl çardak (denizli) graben basin). phd thesis, pp. 242. (in turkish with english abstract, unpublished) toker e. (2017) quaternary fluvials tufas of sarıkavak area, southwestern turkey: facies and depositional systems. quaternary international, nonmarine carbonates, special issue, 437, 37-50. toker e., kayseri-özer m.s., özkul m., kele s. (2015) depositional system and palaeoclimatic interpretations of middle to late pleistocene travertines: kocabaş, denizli, sw turkey. sedimentology, 62 (5), 1360-1383. 164 tagliasacchi e., kayseri-özer m.s. ms. received: may 2, 2018 final text received: may 22, 2018 untitled analisi dinamica di colate detritiche nel bacino di terria (appennino umbro, centro italia) diana salciarini & pietro conversini dipartimento di ingegneria civile e ambientale università degli studi di perugia e-mail: diana@unipg.it riassunto: salciarini d.& conversini p.: analisi dinamica di colate detritiche nel bacino di terria (appennino umbro, centro italia). it issn 0394-3356, 2008). in questo articolo viene presentato lo studio condotto a seguito di due eventi di colata detritica avvenuti nel giugno e nell'agosto del 2005 in un piccolo bacino idrografico situato in umbria orientale, nel centro italia. le precipitazioni derivanti da brevi ed intensi temporali di natura convettiva sono state la causa principale di questi dissesti idrogeologici, che si sono propagati per oltre 2 km lungo la rete di drenaggio. in questo articolo, dopo aver brevemente illustrato le analisi topografiche e idrologiche alla base dello studio, mostriamo l'applicazione del modello numerico flo-2d per simulare la fase di propagazione e deposizione degli eventi di colata. il modello è in grado di simulare il flusso di volume mobilitato e le aree di espansione della colata. anche se concettuale, il modello può essere usato per ottenere informazioni per progettare misure di mitigazione del rischio come, ad esempio, opere trasversali in alveo per il controllo dell'erosione ed il rallentamento della velocità di propagazione. in particolare, il lavoro qui presentato mostra una procedura di analisi articolata in due fasi: la prima contiene la fase di acquisizione ed elaborazione dati e le analisi condotte simulando le condizioni originali del bacino prima degli eventi; la seconda contiene le analisi condotte simulando le condizioni modificate dopo la realizzazione delle opere di mitigazione previste. abstrac: salciarini d.& conversini p.: dynamic analysis of debris flows in the terria watershed, (umbria apennines, central italy). it issn 0394-3356, 2008). the paper presents the study of two debris flow events occurred in june and august 2005 in a small watershed located in the eastern umbria region of central italy. brief, intense convective storm precipitations were the main cause for these processes that flowed for more than 2 km along the drainage network. in this paper, after introducing the topographical and hydrological analyses, we present the application of a commercial numerical model to simulate the propagation and the depositional phase of the events. the model is able to simulate the mobilized volume flow and the expansion areas. although conceptual, the model has implications for the design and effectiveness of various mitigation measures, as check dams for the flow speed reduction and erosion control. in particular, this paper presents a procedure constituted of two phases: in the first one, we describe the data collection and elaboration, and the analyses simulating the original condition of the basin before the events occurrences. in the second phase we describe the results obtained from the simulations considering the modified conditions after the countermeasures installations. parole chiave: colate detritiche, pericolosità, conoidi alluvionali. keywords: debris flow, hazard, alluvial fans. il quaternario italian journal of quaternary sciences 21(1b), 2008 183-192 1. introduzione le colate detritiche sono fenomeni caratterizzati da una notevole azione distruttrice lungo il loro percorso e generalmente manifestano segnali premonitori scarsi o nulli (ad es.: ta k a h a s h i, 1981; ar m a n i n i, 1999; cr o z i e r & gl a d e, 2005). in umbria, tali eventi si registrano principalmente nell'area sud-orientale, dove la concomitanza di coperture detritiche ed elevate pendenze dei versanti costituisce la condizione predisponente per il loro innesco, che si verifica in occasione di piogge particolarmente intense o prolungate (guzzetti & cardinali, 1991; conversini et al., 2005; salciarini et al., 2006a). nell'ultimo decennio, uno dei casi di maggior interesse si è verificato nell'estate 2005 (30 giugno e 31 agosto) lungo l'alveo del fosso di terria, nel comune di ferentillo (provincia di terni) (figura 1). i volumi depositati nella fase di arresto hanno provocato l'interruzione della viabilità locale di accesso al nucleo storico dell'abitato omonimo, danneggiando il ponte ed ostruendo il canale di deflusso sottostante. la previsione dei possibili volumi solidi che le colate detritiche possono depositare in un conoide è una problematica di grande importanza nella scelta delle misure da adottare per la gestione del rischio. a questo scopo possono essere di grande utilità dei modelli teorici che, applicati secondo un preciso schema di lavoro, possono fornire risultati importanti per la modellazione della fase pre e post intervento. in quanto segue, si vuole presentare lo studio condotto a seguito degli eventi di colata detritica appena introdotti. 2. inquadramento dell'area di studio: colate detritiche nel bacino del fosso di terria il bacino idrografico in esame è situato nella catena appenninica centrale (figura 2), nella zona della valnerina. l'intera zona è caratterizzata da una morfologia collinare con valli strette e versanti acclivi. il bedrock affiorante è costituito da una sequenza di calcari con frazione marnosa più pronunciata nella parte alta della sequenza (formazioni della serie umbro-marchigiana) (ca l a m i t a & de i a n a, 1986; gu z z e t t i & ca r d i n a l i, 1991; 184 d. salciarini & p. conversini conversini et al., 2005; salciarini et al., 2006a). inoltre è presente una percentuale di territorio in cui affiora una copertura colluviale, con spessori diversi, essenzialmente in funzione dell'acclività dello strato coesivo sottostante (salciarini et al., 2006b). la configurazione climatica dell'appennino centrale deriva dall'interazione tra le caratteristiche morfologiche della catena montuosa e le caratteristiche dei percorsi atmosferici locali. il clima è tipico del la zona appennino mediterranea, con estati secche e inverni miti, con due picchi stagionali di pioggia: uno in tardo autunno (novembre) ed uno in primavera (aprile ) (co r r a d i n i & me l o n e, 1988; sa l c i a r i n i et al., 2006b). i l primo evento importante di colata detritica lungo il fosso di terria di cui si ha memoria risale al 1965. la colata detritica attraversò il centro abitato ed arrivò fino al sottostante fiume nera (circa 2 km a valle), ostruendolo parzialmente. recentemente sono avvenuti due eventi nel bacino di terria, ripetuti a distanza di circa due mesi. il primo si è verificato il 30 giugno 2005, a seguito di un temporale molto intenso e concentrato in un'area molto ristretta. la pioggia è iniziata nel tardo pomeriggio e, dopo due ore, si è innescata la prima onda di colata che ha investito la strada comunale che porta al paese, ostruendo un ponte di attraversamento e interrompendo la circolazione. il secondo evento si è verificato la sera del 31 agosto, a seguito di un temporale altrettanto violento ma di durata leggermente inferiore (circa 1 ora e mezzo). in figura 3 è riportata una planimetria del bacino con l'individuazione delle aree significative per la descrizione del fenomeno. in entrambi i casi, i danni principali hanno riguardato la strada provinciale che porta al centro abitato, che è stata completamente invasa dai sedimenti, restando così impraticabile per alcuni giorni (figura 4a e 4b). inoltre, particolarmente evidente è apparso il canale di erosione scavato dalla colata, in alcuni punti profondo anche fino a 3 metri (figura 5). 2.1 interpretazione qualitativa dei fenomeni avvenuti lungo il fosso di terria nell'estate 2005 a seguito dei due eventi di colata detritica avvenuti nell'estate 2005 lungo l'alveo del fosso di terria, sono stati realizzati rilievi in campagna ed analisi di laboratorio per fornire una caratterizzazione qualitativa dei fenomeni. entrambi gli eventi di colata si sono innescati a seguito dell'apporto idrico proveniente da violenti temporali estivi. le elevate pendenze dei versanti laterali al fosso di terria (oltre 45° per circa il 60% dell'invaso) hanno conferito a questi pendii un comportamento quasi impermeabile, permettendo solo ad una modesta frazione di pioggia di infiltrarsi effettivamente. la frazione preponderante è andata invece a costituire un ruscellamento superficiale che si è rapidamente riversato verso l'alveo del fosso di terria, dove si è accumulata un'onda di piena in grado di prendere in carico volumi di materiale anche notevoli. dai sopralluoghi effettuati e dall'analisi degli eventi avvenuti, è apparso evidente che nel bacino del fosso di terria le colate detritiche sono alimentate dagli apporti detritici che convergono nell'alveo del fosso stesso dai versanti laterali precedentemente all'innesco fig. 1panorama dopo la colata di detrito verificatasi nel giugno 2005. landscape after the debris flow occurence, in june 2005. fig. 2 localizzazione dell'area di studio. localization of the study area. e qui si depositano (figure 6a e 6b). le pendenze del fosso (inferiori ai 13°) non sono sufficienti a generare condizioni critiche in condizioni ordinarie; durante la maggior parte dell'anno, infatti, il fosso di terria non è interessato da deflusso idrico superficiale, se non in modo estremamente limitato; questo può invece verificarsi successivamente ad eventi pluviometrici particolarmente rilevanti. in definitiva, la mobilizzazione di colate detritiche, cioè il meccanismo che ha determinato il passaggio da massa solida a materiale fluido che è scorso lungo la convergenza topografica rappresentata dal fosso di terria, sembra essere stata dominata da un processo di flusso superficiale che ha incorporato progressivamente materiale solido e aumentato la concentrazione. la comparsa di ruscellamento superficiale, e soprattutto di ondate improvvise ha determinato delle rotture localizzate nei tratti più pendenti lungo il letto del canale, che durante il resto dell'anno risultano stabili poiché le pen185analisi dinamica di colate detritiche ... fig. 3 bacino di studio con individuazione delle aree sorgenti di detrito, canale di erosione e deposito della colata. study watershed with localization of debris source areas, erosion channel and f inal deposit. fig. 4 a) deposito finale del fronte della colata, si può osservare che gli alberi sono stati ricoperti per tutta l'altezza del fusto; b) parte di deposito che ha oltrepassato la strada. a) final deposit of the front of the debris flow, notice that trees were partially covered by the sediments; b) portion of deposit that passed the local road. fig. 5 canale di erosione prodotto dalla colata detritica nel fosso di terria. erosion channel produced by the debris flow. denze sono limitate. le masse in movimento si sono poi arrestate in modo naturale in corrispondenza delle locali diminuzioni di pendenza, creando lobi di accumulo sia lungo il canale stesso, che, soprattutto, in corrispondenza della strada di accesso al centro abitato. 3. caratteristiche e funzionamento del modello flo-2d la simulazione numerica di colate detritiche presenta notevoli difficoltà a causa delle complessità del fenomeno fisico e, conseguentemente, delle equazioni necessarie per descriverlo. per questo motivo, i dati provenienti da rilievi e misure eseguiti in sito risultano estremamente importanti sia per quanto attiene gli aspetti teorici del problema (determinazione del comportamento reologico), sia per quelli più strettamente "pratici" (predisposizione delle misure di contenimento o prevenzione, definizione di sistemi di allarme etc..). nella maggior parte dei casi, i codici numerici che simulano il comportamento di una colata detritica considerano la miscela liquido-solido come se fosse un fluido omogeneo equivalente, il cui comportamento è descritto da un'assegnata formulazione reologica. in generale i parametri di input per tali modelli sono costitutiti da: • la topografia della zona in esame; • l'idrogramma della colata; • i parametri reologici della massa instabile. in particolare, l'analisi idrologica di dettaglio e la scelta di una reologia appropriata sono di fondamentale importanza. la calibrazione di questi parametri può essere condotta attraverso una procedura di back analysis sugli eventi conosciuti. allo scopo di valutare le condizioni di rischio dell'area in esame è stato applicato il modello numerico flo-2d (o'br i e n 2002). il codice di calcolo flo-2d è un modello bidimensionale, sviluppato da j. s. o'brien e aggiornato nel 2006, distribuito da flo-2d software inc. e' un modello che può essere usato sia per la simulazione di eventi di piena che per specifiche applicazioni nell'ambito della modellazione delle colate. flo-2d fa parte dei modelli idraulici approvati dalla u.s. fema (u.s. federal emergency management agency) per questo tipo di studi. questo codice di calcolo permette di simulare, in moto vario, la propagazione e la deposizione dell'idrogramma liquido-solido di una colata. la progressione dell'idrogramma liquido-solido avviene su un sistema di elementi quadrati di una griglia a maglia fissa. il metodo di calcolo è basato sull'integrazione numerica alle differenze finite delle equazioni di continuità e di conservazione della quantità di moto. il comportamento del materiale viene descritto da un modello reologico quadratico, che combina le componenti di resistenza dovute a taglio, viscosità, collisioni e turbolenza in funzione della concentrazione del sedimento; in esso al termine viscoplastico del modello di “fluido alla bingham”, viene aggiunto un termine turbolento dispersivo. la viscosità � e la resistenza al taglio �y d e l l a miscela variano principalmente in funzione della concentrazione volumetrica del sedimento cv. per calcolare la viscosità � e lo sforzo di taglio �y della miscela, flo2d utilizza le seguenti relazioni empiriche: �y = �1 e �1cv � = �2 e �2cv dove �1, �2 e �1, �2 sono coefficienti empirici definiti in laboratorio (o'brien e julien, 1988). 186 fig. 6 a) coltre detritica lungo il pendio laterale al fosso di terria, parzialmente vegetata, fotografata prima dell'evento del giugno 2005; b) area di alimentazione laterale, fotografata dopo l'evento. a) colluvial cover along a steep slope in the terria basin, partially vegetated; the picture was taken before the debris flow of june 2005; b)lateral source area of debris material, the picture was taken after the event. a) b) d. salciarini & p. conversini in definitiva, ci sono due passi importanti da affrontare per iniziare una simulazione con flo-2d: ottenere i dati topografici e determinare una colata detritica di progetto associata a un evento meteorologico estremo. 4. modellazione delle colate lungo il fosso di terria 4.1 schema di lavoro la procedura per lo studio degli eventi di colata avvenuti lungo il fosso di terria si articola in due fasi distinte, di seguito brevemente descritte. la prima fase ha previsto i seguenti passi: realizzazione di un modello tridimensionale del terreno per l'individuazione del bacino idrografico di riferimento e delle sotto-aree di drenaggio per poter simulare il contributo che ciascun punto dell'area in esame fornisce al movimento dell'ammasso; stima della pioggia massima attesa sul bacino di terria mediante elaborazione delle registrazioni storiche derivanti da 5 pluviometri circostanti; stima dell'idrogramma di massima piena con il metodo di nash, mediante implementazione di un foglio di calcolo; stima dell'idrogramma di progetto della colata detritica, mediante assegnazione di un valore di concentrazione per la fase solida; scelta di una reologia per la colata di terria, mediante procedure di back-analysis. modellazione delle condizioni pre-intervento, stima delle caratteristiche dinamiche e cinematiche della colata in assenza di strutture di difesa. la seconda fase ha previsto i seguenti passi: modellazione delle condizioni post-intervento, stima delle caratteristiche dinamiche e cinematiche della colata in presenza di strutture trasversali in alveo 4.2 elaborazioni topografiche del territorio di studio la topografia del luogo in esame è un'informazione importante poiché questa influisce sullo spessore della colata, sulla velocità e sul suo deposito finale. allo scopo di ottenere un dato topografico di dettaglio, è stato realizzato un dtm (modello digitale del terreno) del bacino del fosso di terria, mediante elaborazione della cartografia vettoriale regionale in scala 1:10,000 disponibile (sezioni n. 336100, 336110, 336140, 336150). tale dtm fornirà le informazioni topografiche di base per le successive simulazioni ed è costituito da una griglia a maglie quadrate la cui risoluzione al suolo dipende dalla grandezza delle maglie stesse (pari a 10 metri). al modello sono state quindi sovrapposte le sezioni corrispondenti delle ortofoto a colori, per una “lettura” del territorio di studio più immediata. successivamente, è stato delimitato il bacino idrologico di riferimento, che comprende l'asta principale e tutti i corsi minori di apporto laterale (figura 7), per un'area complessiva di circa 4.36 km2. 4.3 analisi idrologica: stima delle piogge massime attese e' ormai consolidato che le colate detritiche si verificano in occasione di eventi pluviometrici intensi preceduti o meno da altre precipitazioni (ad es. bianco, 1999). per poter applicare convenientemente i modelli idrologici di trasformazione afflussi-deflussi cui occorre far ricorso per interpretare i debris flow che si manifestano lungo la rete idrografica in esame, si è proceduto all'analisi del regime delle piogge intense, utilizzando i dati registrati in corrispondenza di cinque pluviometri circostanti il bacino di interesse: stazioni di leonessa (974 m slm), terni (130 m slm), spoleto (317 m slm), monte terminillo (1800 m slm) e posta (750 m slm) (figura 8). 187 fig. 8 pluviometri limitrofi all'area di studio utilizzati per la determinazione della massima pioggia attesa sul bacino. localization of the five rain gauges used for determining the “precipitation-duration-frequency” curves for the terria watershed. fig. 7 delimitazione del bacino del fosso di terria sovrapposto all'ortofoto a colori. aerial photo overlaid to the digital elevation model. analisi dinamica di colate detritiche ... l'analisi, facendo riferimento a serie storiche di dati, è stata finalizzata alla determinazione delle linee segnalatrici di possibilità pluviometrica (lspp) valide per il bacino di terria. una linea segnalatrice di possibilità pluviometrica è una curva che relaziona le coppie precipitazione durata per determinati tempi di ritorno analizzati. in assenza di un pluviometro di riferimento per l'area in esame, il metodo che si è scelto di usare è stato quello di individuare i 5 pluviometri circostanti più vicini e utilizzare le loro registrazioni, effettuando un'operazioni di media pesata rispetto alle distanze dei pluviometri di riferimento dal centroide del bacino di terria. i risultati statistici così ottenuti, che individuano le massime piogge attese per tempi di ritrono pari a 50, 100 e 200 anni, sono mostrati in figura 9. i tempi di ritorno degli eventi pluviometrici del 2005 che hanno innescato le colate sono inferiori ai 200 anni, tuttavia si è scelto di adottare questo valore dalle considerazioni svolte nell'ambito della direttiva pai, in cui il tempo medio di ritorno nelle analisi di rischio viene ipotizzato in base ai beni da proteggere. in questo studio, quindi, l'attenzione è focalizzata sulla lspp relativa ad un tempo di ritorno tr=200 anni, che ben rappresenta le condizioni estreme di pioggia in corrispondenza di cui si possono verificare i fenomeni franosi tipo colata detritica (ad es: caine, 1980; bianco et al., 1999). in tabella 1 si riportano gli spessori di pioggia massima derivanti dall'elaborazione. la relativa linea segnalatrice di possibilità pluviometrica, stimata per un tempo di ritorno (tr) pari a 200 anni, è esprimibile attraverso la seguente funzione: rd = 59.84 . d0,35 dove rd è lo spessore di pioggia atteso e d è la durata della pioggia. 4.4 stima dell'idrogramma di progetto della massima portata liquida attesa per la determinazione degli idrogrammi di massima piena, a partire dalle piogge cinquantennali e duecentennali si deve far riferimento ad opportune relazioni di trasformazione “afflussi deflussi”. in questo studio, si è scelto di ricostruire l'idrogramma di progetto della portata liquida attraverso il metodo di nash, espresso dalla relazione: ab ru t j-1 h(t) = ––––––––– ( ––– ) e-t/k (j 1)!k k dove ab è l'area del bacino, ru la pioggia netta e k e j sono dei parametri funzione delle caratteristiche fisiche del bacino, scelti, rispettivamente, pari 3 (numero dei serbatoi, valore tipico per bacini di dimensioni ridotte) e 0.408 (secondo la formula di nash, 1960). in seguito, a partire dai valori di portata nel tempo, sono stati ricavati i rispettivi valori di picco da utilizzare nelle simulazioni. in tal modo si è in grado di simulare ciò che realmente accade quando un evento pluviometrico particolarmente intenso genera le condizioni critiche per l'innesco di un debris flow. sono infatti gli scrosci violenti e di breve durata ad destabilizzare gli ammassi detritici (ad es: ca i n e, 1980; re i d, 1994; bianco et al., 1999). 4.5 stima dell'idrogramma di progetto della colata detritica per l'assegnazione dell'idrogramma della colata e della sua concentrazione sono state seguite delle linee guida pratiche che suggeriscono come assumere dei valori ragionevoli per le variabili che controllano i processi fisici dei flussi (ju l i e n & o'br i e n, 1997). queste variabili includono, principalmente, la concentrazione dei sedimenti in acqua e le proprietà dei sedimenti e del fluido. la concentrazione dei sedimenti varia durante il percorso della colata, dal suo innesco al suo arresto. essendo un parametro molto variabile, non può mai essere riportato con assoluta certezza; esistono tuttavia delle linee guida da seguire nell'assegnazione della concentrazione di sedimenti in un idrogramma di piena: • in corrispondenza del ramo ascendente dell'idrogramma di piena, determinato con nash (o qualsiasi altra legge di trasformazione afflussi-deflussi) , dovrebbe essere assegnata la concentrazioni di sedimenti più alta, per simulare l'ondata frontale; • alla portata di picco dovrebbe essere assegnata una concentrazione di sedimenti leggermente inferiore all'ondata frontale per tenere conto della diluizione; • i rami ascendente e discendente dell'idrogramma non dovrebbero avere meno del 20% della concentrazione volumetrica dei sedimenti; 188 fig. 9linee segnalatrici di possibilità pluviometrica per diversi tempi di ritorno. rainfall depth duration curves, for different recurrence intervals. tab. 1 spessori massimi di pioggia attesi (in mm) stimati per terria per diversi tempi di ritorno (tr) e per le durate di 1, 3, 6, 12, 24 ore. expected maximum heights of rainfall (mm) in the terria basin, for different recurrence intervals and rainfall durations. 1 ora 3 ore 6 ore 12 ore 24 ore tr 10 38.48 56.41 72.05 92.28 118.51 tr 25 45.20 66.27 84.65 108.44 139.28 tr 50 50.18 73.58 94.00 120.42 154.68 tr 100 55.12 80.84 103.28 132.31 169.97 tr 200 60.05 88.07 112.53 144.17 185.21 d. salciarini & p. conversini • per dare origine ad un debris flow la concentrazione di sedimenti media dell'intero idrogramma dovrebbe rientrare tra il 25% e il 35% del volume con la concentrazione di picco dell'onda frontale compresa tra il 45% ed il 53% della concentrazione volumetrica. nel presente studio, all'idrogramma liquido è stata associata una concentrazione volumetrica variabile da 0.3 a 0.6 nei tratti ascendente e discendente dell'idrogramma. 4.6 stima della reologia della colata di terria le proprietà del fluido equivalente con cui viene schematizzata la colata variano con la concentrazione dei sedimenti e con i valori assegnati di viscosità e resistenza attritiva. per l'assegnazione di questi ultimi sono stati raccolti campioni di deposito, sia lungo l'asta fluviale, in corrispondenza delle aree dove localmente si sono creati lobi di accumulo (ad esempio per allargamenti della sezione dell'alveo o per locali riduzioni di pendenza), sia in corrispondenza dell'accumulo finale. questi sono stati setacciati separando sabbia e ghiaia dalla frazione fine. in base alle linee guida precedentemente citate, infatti, quanto maggiore è la percentuale di sedimenti fini, tanto maggiore è la componente viscosa di comportamento. al contrario, se la matrice più grossolana è preponderante, prevale un comportamento attritivo della massa in movimento, che principalmente giunge all'arresto per le collisioni intergranulari delle particelle. l'analisi granulometrica costituisce dunque un punto di partenza per avere informazioni qualitative sulla tipologia di comportamento. in figura 10 sono riportate alcune delle prove granulometriche condotte lungo la mediana longitudinale del canale per diverse sezioni trasversali. si osserva come la componente ghiaiosa e sabbiosa sia indubbiamente preponderante. si precisa che tali analisi sono state effettuate su campioni di terreno prelevate a 50 80 cm dalla superficie, quindi nello strato superficiale che costituisce, teoricamente, lo strato mobilitato. a partire da queste analisi, ed in mancanza di indagini reologiche specifiche, i valori dei parametri �1 e �1 per il calcolo di � e �y da assegnare alla colata di progetto sono stati stimati attraverso una procedura di calibrazione basata sul confronto con gli spessori dei depositi e sull'estensione dell'area alluvionata rilevati a seguito degli eventi noti. sono state cioè eseguite una serie di simulazioni variando i valori della viscosità e della resistenza a taglio all'interno di un range predefinito di letteratura (o'br i e n, 2002). per la calibrazione, i dati disponibili relativi all'evento del 2005 con cui confrontare i risultati includono attraverso rilievi diretti in situ: l'estensione dell'area alluvionata e la distanza di propagazione il volume del materiale depositato, pari a circa 16000 m3 gli spessori dei depositi osservati, fino a 2.0 m nella zona di deposizione del fronte la miglior corrispondenza è stata ottenuta per i parametri riportati di seguito in tabella 2. 5. risultati della simulazione si riportano di seguito, in forma tabellare (tabella 3), i valori dei parametri principali caratterizzanti il dissesto idrogeologico simulato. per potenziali fenomeni di colate detritiche, associate ad eventi pluviometrici estremi con tempo di ritorno duecentennale, vengono mostrati i seguenti valori, risultati dalla modellazione predittiva svolta con flo-2d: la massima altezza del flusso detritico, l'accumulo detritico depositato all'arre189 fig. 10 analisi granulometriche lungo la mediana longitudinale per diverse sezioni. grain-size analysis for different cross-sections along the center of the channel. tab. 2 parametri assegnati alla colata di progetto a seguito della procedura di back-analysis. values assigned to the rheological parameters after the backanalysis procedure. �y = � e �c � = � e �cv �1 �1 �1 �2 0.000707 29.8 0.00632 19.9 analisi dinamica di colate detritiche ... tab. 3 risultati della simulazione per la colata di progetto. results from the dynamical simulations of the debris flow. tr = 200 anni massima altezza del flusso detritico (m) 2.3 accumulo detritico depositato (m3) 19008.0 volume totale mobilitato (m3) 43800.0 area inondata dal debris flow (m2) 32848.0 spinta dinamica (n/m) 18330.0 spinta statica (n/m2) 23770.0 sto della colata, il volume totale mobilitato, l'area inondata dal debris flow, la massima forza di impatto dinamica (impulsiva) posseduta dalla massa in movimento, e il massimo valore della pressione statica lungo il percorso della colata. dai risultati delle simulazioni si può constatare che, per tempi di ritorno duecentennali, possono verificarsi potenziali debris flow in grado depositare e di ri lasciare in conoide e sull'infrastruttura stradale ai piedi del centro abitato un volume stimato di ol tre 19000 m3 (molto prossimo al valore rilevato in sito immediatamente dopo l'evento) e mobilitare un volume complessivo di oltre il doppio (circa 44000 m3). il primo rappresenta il volume del lobo finale della colata in fase di arresto, quindi le volumetrie che hanno costituito il cumulo di deposito in corrispondenza della riduzione di pendenza. il secondo rappresenta il volume complessivamente preso in carico e trasportato dalla colata che si è ridepositato durante il percorso, ad esempio creando argini laterali, senza raggiungere la zona di riduzione di pendenza. il rapporto esistente tra queste due quantità è ampiamente documentato in letteratura (ad es: ri c k e n m a n n & zi m m e r m a n n, 1993; rickenmann, 1997) in figura 11 è mostrata la visualizzazione grafica dei risultati ottenuti mediante l'utilizzo del post processore mapper, applicativo dello stesso software flo-2d, per quanto riguarda l'estensione e lo spessore dei depositi. l'area di inondazione dei depositi è ben correlabile con quella effettivamente verificatasi in entrambi gli eventi di colata, così come gli spessori massimi raggiunti dal deposito. 6. modellazione delle condizioni postintervento dai recenti sopralluoghi si è osservato come il bacino di terria possieda ancora una notevole disponibilità di materiale potenzialmente mobilizzabile da eventi pluviometrici estremi, posto in zone ad elevata pendenza. nel tratto del fosso di terria localizzato immediatamente a monte dell'infrastruttura viaria, sono stati realizzati degli interventi di somma urgenza dopo l'evento dell'estate del 2005, costituiti da una serie di tre briglie selettive in maglie di acciaio che assolvono il compito di protezione passiva per la strada qualora si dovessero innescare ulteriori dissesti lungo l'alveo (figura 12). per la difesa attiva da tali fenomeni sono in progetto un sistema di briglie che giustifica il secondo set di simulazioni, di cui si parlerà a breve, attraverso cui verranno modellate le condizioni post-intervento modificate dalla presenza di opere di sbarramento in alveo. 190 fig. 11 risultati della simulazione utilizzando la colata detritica di progetto. results of the simulation using the “project” debris flow. fig. 12 briglie selettive in acciaio installate poche settimane dopo gli eventi di colata detritica per proteggere la strada dai sedimenti. selective steel check-dams installed few weeks after the debris flow events to protect the road from the sediment. 6.1 descrizione degli interventi previsti l'intervento in progetto prevede un sistema di briglie che verranno inserite a monte di interventi già esistenti. l'area, cronologicamente, ha visto infatti la realizzazione delle seguenti opere: d. salciarini & p. conversini a seguito di colate detritiche avvenute nel 1965 lungo lo stesso alveo vennero posizionate 4 briglie in gabbioni, poi completamente ricoperte nel corso degli anni da un notevole strato detritico al punto che non era più certa la loro localizzazione; a seguito della colata detritica del 2005, durante gli interventi di somma urgenza, sono state realizzate 3 briglie selettive in rete d'acciaio, posizionate a valle di quelle precedentemente citate, con lo scopo primario di proteggere la strada sottostante. il progetto prevede la realizzazione di otto briglie a monte delle quattro in gabbioni già esistenti, di cui le prime due, nel tratto più in alto dell'alveo, di altezza minore rispetto alle altre, che assolvono una funzione di consolidamento dell'alveo più che di trattenuta (quest'ultima svolta appunto dalle briglie più a valle). 6.2 risultati della modellazione della colata detritica in presenza di opere in alveo tramite flo-2d le briglie possono essere inserite all'interno del modello che schematizza il problema in esame. e' interessante osservare come la presenza di queste opere modifichi le aree di espansione a valle del deposito detritico previste e i suoi spessori. partendo dalla planimetria dell'area di intervento, ciascuna briglia prevista dal progetto viene importata all'interno del gis e inserita nel dtm del bacino di riferimento mediante creazione di uno shapefile. ciascuna briglia va dunque ad interessare una elemento della griglia, all'interno del quale viene così modellata la struttura idraulica. la struttura idraulica da modellare comporta l'interruzione di una o più delle possibili otto direzioni che la colata può intraprendere all'interno di un elemento della griglia. si riportano, pertanto, di seguito i risultati ottenuti dalle simulazioni riguardanti le situazioni pre e post intervento effettuate con i medesimi parametri geometrici e reologici utilizzati in tutte le prove precedentemente discusse (tabella 4). come si può notare i valori risultano estremamente minori nel caso riguardante la situazione post intervento. ciò è anche qualitativamente osservabile nelle visualizzazioni grafiche delle aree interessate dall'espansione dell'ammasso, presentate di seguito (figura 13). 7. discussione conclusiva le colate detritiche sono fenomeni che possono avvenire manifestando scarsi preavvisi ed esercitando una notevole azione distruttiva su tutto ciò che cerca di ostacolarne il moto. la valutazione della pericolosità da colata è un compito molto complesso poiché vi concorrono numerosi fattori: da quelli meteorologici a quel li morfologici e meccanici. per ridurre tale pericolosità possono 191 tab. 4 suddivisione del bacino in nove sottobacini: situazione post intervento. subdivision of the basin into nine drainage areas: situation after the remedial works. tr = 200 anni massima altezza del flusso detritico (m) 1.0 accumulo detritico depositato (m3) 4310.0 volume totale mobilitato (m3) 11510.0 area inondata dal debris flow (m2) 12592.0 spinta dinamica (n/m) 600.0 spinta statica (n/m2) 9397.0 essere usati opere sia strutturali che non strutturali. questi metodi, così come i piani di protezione, richiedono la zonizzazione delle aree deposizionali, che comunemente è condotta attraverso simulazioni con modelli matematici, anche se è ancora attualmente mancante una procedura di riferimento. in termini generali, la valutazione e la gestione della pericolosità richiedono la conoscenza di due argomenti principali: inizialmente deve essere stimata la possibilità che un evento avvenga in una determinata zona e in un determinato momento; in seguito, una volta che l'evento è stato innescato, l'obiettivo è conoscere il comportamento della massa in movimento, sia in termini di localizzazione dei percorsi che di posizioni raggiungibili dai sedimenti. l'attendibilità dei risultati ottenuti è fortemente legata all'accuratezza con cui vengono rilevati i dati che costituiscono l’input per i codici di calcolo (dati pluviometrici ed idrometrici, topografia, osservazione di eventi simili a quelli da simulare, ecc.). pertanto, soprattutto se sono carenti i dati con cui poter fare un'analisi di sensitività e calibrazione dei modelli, i risultati devono essere interpretati in base all'esperienza diretta. fig. 13 risultati della simulazione utilizzando la colata detritica di progetto, nella condizione successiva alla realizzazione delle opere di mitigazione del rischio. results of the simulation using the “project” debris flow in the modified conditions by the planned countermeasures for the risk reductions. analisi dinamica di colate detritiche ... ringraziamenti questo articolo contiene parte dei risultati derivanti dallo studio finanziato dalla convenzione di ricerca tra il dipartimento di ingegneria civile e ambientale dell'università di perugia ed il comune di ferentillo. gli autori desiderano ringraziare il servizio difesa del suolo ed il servizio geologico della regione umbria per il supporto tecnico durante le fasi del lavoro. infine, gli autori ringraziano in modo particolare r. morbidelli e c. saltalippi per il supporto scientifico nella parte idrologica dello studio. bibliografia armanini a. (1999) previsione e prevenzione del rischio da colata di detriti in: il rischio idrogeologico e la difesa del suolo, accademia nazionale dei lincei, atti dei convegni lincei, n. 154, 13-44. bianco g., ruberto g., brochot s. & laigle d. (1999) progetto interreg ii italia-francia 1994-1999; azione 5: condivisione di metodi e conoscenze sui processi di lave torrentizie per la difesa dei centri abitati. ca i n e n. (1980) the rainfall intensity-duration control of shallow landslides and debris flows geogr. ann., ser. a, v. 62, p. 23-27. ca l a m i t a f. & de i a n a g. (1986) g e o d i n a m i c a dell'appennino umbro-marchigiano memorie della società geologica italiana, 35, 311-316. conversini p., salciarini d., felicioni g. & boscherini a. (2005) the debris flow hazard in the lagarelle creek in the eastern umbria region, central italy nhess, vol. 5, p. 275-283. corradini c. & melone f. (1988) spatial distribution of pre-warm front rainfall in the mediterranean area nordic hydrology, 19: 53-64. crozier m.j. & glade t. (2005) landslide hazard and risk: issues, concepts and approach in: glade, anderson and crozier (eds.), landslide hazard and risk. wiley, 824 p. guzzetti f. & cardinali m. (1991) debris-flow phenomena in the central appenines of italy. terra nova, 3: 619-627. o ' br i e n s.j. (2002) flo-2d user manual. flo-2d software inc., usa. re i d e.m. (1997) slope instability caused by small variations in hydraulic conductivity. journal of geotechnical and geoenvironmental engineering 123(8):717-725. sa l c i a r i n i d, co n v e r s i n i p, & go d t jw (2006a) characteristics of debris flow events in eastern umbria, central italy. in: proceeding of iaeg2006, london, uk. sa l c i a r i n i d., go d t j.w., sa v a g e w.z., co n v e r s i n i p . , ba u m r.l. & mi c h a e l j.a. (2006b) m o d e l i n g regional initiation of rainfall-induced shallow landslides in the eastern umbria region of central italy. landslide, vol. 3 n. 3. rickenmann d. (1997) estimation des laves torrentielles, ias ingenieurs et architectes suisses, vol. 19, 386-392. ri c k e n m a n n d. & zi m m e r m a n n m. (1993) the 1987 debris flow in swizerland documentation and analysis, geomorphology, vol. 8, 175-189. takahashi t. (1981) debris flows. annual review of fluid mechanics, vol.13: 57-77. 192 ms. ricevuto il 28 febbraio 2008 testo definitivo ricevuto il 30 maggio 2008 ms. received: february 28, 2008 final text received: may 30, 2008 d. salciarini & p. conversini imp.kalicki& river response to the holocene climatic fluctuations: a case study from zelvianka river valley (belorussia) tomasz kalicki1, gilberto calderoni2 & valentina p. zernitskaya3 1department of geomorphology and hydrology, institute of geography and spatial organization, polish academy of sciences, krakow, poland ph.: +48 124293856 2dipartimento di scienze della terra, università “la sapienza”, p.le a. moro, 5 00185 istituto di geologia ambientale e geoingegneria (cnr) roma, italia. e-mail: gilberto.calderoni@uniroma1.it 3institute of geological sciences, national academy of sciences, kuprevicha str., 7 220141 minsk, belorussia. abstract: kalicki t. (et.al.), river response to the holocene climatic fluctuations: a case study from zelvianka river valley (belorussia). (it issn 0394-3356, 2004). a multidisciplinary research aimed at depicting the evolution of zelvianka river valley (nw belorussia) during the holocene has been carried out. the valley incision started at the local ice-sheet terminus in the young pleniglacial following the pomerian stage of the last glaciation (some 16÷15 ka bp) and, as marked by important changes of the river regime, was virtually over at c. 13.8 ka bp (middle lithuanian stage of deglaciation). detailed geomorphologic survey coupled with stratigraphic analysis, 14c dating and pollen spectra provided sound evidence that the complex structure of the valley bottom resulted from the lateral migration of the river which in turn depended upon large-scale climatic changes. besides of critically reviewing the literature data new, 14c dated pollen chronostratigraphies, fairly consistent with the up to date regional palynologic framework were obtained. actually it has been found that the most important channel and sedimentation changes cluster at the al/yd transition, c. 9300 bp, bo/at transition, middle atlantic, c. 4200 bp, c. 3250-3000 bp, roman time (2100 bp) and 1000-900 bp, thus matching the timing of humid and cool climatic phases recorded by the enhanced activity of belorussian and central european rivers. though the first prehistoric settlements over the study area date back to late neolithic, zelvianka valley was virtually unaffected by the human impact, except from some low intensity, local aeolian processes which developed in the subboreal and subatlantic on the deforested spots riassunto: kalicki t. (et.al.), effetti delle fluttuazioni climatiche oloceniche sull’evoluzione della valle del fiume zelvianka (n-w bielorussia). (it issn 0394-3356, 2004). e’ stata effettuata una ricerca multidisciplinare finalizzata alla ricostruzione dei tratti evolutivi più salienti della valle del fiume zalvianka (bielorussia nord occidentale) durante l’olocene. l’incisione di questa valle, iniziatasi nel pleniglaciale al termine dello stadio pomeriano dell’ultima glaciazione (ca. 16÷15 ka bp) e conclusasi a ca. 13,8 ka bp (media deglaciazione lituana), ha registrato importanti cambiamenti del regime fluviale. i dati geomorfologici, stratigrafici, palinologici unitamente a quelli della cronologia radiocarbonio concordano nell’indicare che la complessa struttura del fondo della valle deriva dalle migrazioni laterali del fiume che, a loro volta riflettono variaizioni climatiche di portata almeno regionale. lo studio ha evidenziato che le maggiori variazioni tanto nel regime di sedimentazione che nella direzione del corso fluviale si sono verificate alla transizione alleröd/dryas iii, a ca, 9300 bp, alla transizione boreale/atlantico inferiore, nel medio atlantico, a ca. 4200 bp, a ca. 3250÷3000 bp, in epoca romana (2100 bp) ed infine dal 1000 al 900 bp. la datazione di tali eventi ne rivela la contemporaneità con fasi climatiche umide e fredde di portata almeno regionale in quanto precedentemente riportate per molte valli fluviali della bielorussia e dell’europa centrale. nonostante la presenza di insediamenti umani nell’area di studio a partire dall’ultimo neolitico, la valle del fiume zelvianka non mostra significative evidenze di impatto antropico, eccezion fatta per modesti processi eolici attivi nel pre-boreale e nell’atlantico inferiore nelle modeste aree soggette a deforestazione da parte dell’uomo. keywords: holocene, belorussia, climate fluctuations, river valley, radiocarbon dating, pollen analysis. parole chiave: bielorussia, olocene, fluttuazioni climatiche, cronologia radiocarbonio, analisi pollinica. il quaternario italian journal of quaternary sciences 17(2/1), 2004, 165-180 introduction the pleistocene development of zelvianka valley (fig.1) resulted from the degradation of neman stream sozhian (moscovian) ice sheet, damming of neman river by valday ice sheet and level changes of the late valday (vistulian) ice-dam skidel lake (vozniachuk and valchik, 1978). zelvianka valley cuts the belorussian upland accordingly to the glacial valley of the kataglacial period of sozhian glaciation (gorecki, 1980). the valley, only 100-200 m wide at a narrow gap section nearby piaski village (piaski gate), where it crosses the northernmost morainic ridge with glaciotectonic features (levkov, 1980), broadens suddenly up to 2.5-3.0 km in the downstream flat upper neman plain (fedenya et al., 1985). the valley evolution during the last glaciation was controlled by the recurrent fluctuations of the ice sheet terminus. following river damming by the ice sheet, fine sands with silt intercalations (usviacha series) accumulated in neman as well as in zelvianka river valleys. then, the whole upper neman plain was overflooded (maximum level: 128-138 m a.s.l.) by the ice-dam skidel lake (vozniachuk and valchik, 1978) and a limnoglacial suite, resembling varve sediments (thin fine sands and sandy silts layers) was deposited (kovbasyuk and ivanov, 1998). the sequence, with ice wedges at the top (levkov et al., 1988), records the progressive shallowing of skidel lake during the recession of the last ice sheet, when terraces were originated 166 t. kalicki, g. calderoni & v. zernitskaya fig. 1 sketch map of the study area. the location of the reference pollen spectra mentioned in the text is as follows:1 – podbarany, 2 – ogorodniki, 3 – kremushovka, 4 morino. by the zelvianka river erosion of the limnological suite. the incision, 4-5 m deep near piaski, deepens gradually downstream up to 10-11 m at the river mouth. at present the lacustrine sediments blanket a very flat plain (116-117 m a.s.l.) and only small relics of the former terraces, barren of organic matter are preserved. despite the numerous companion papers focusing on the zelvianka river valley near piaski village (fedenya et al., 1985, 1992; levkov et al., 1988; ivanov, 1993, 2001; ivanov and yelovicheva, 1997), the overall framework for the lateglacial-holocene development of the valley is still unsatisfactory for relying on palaeobotanical and palaeozoological chronosequences lacking isotope dating and accurate location. this work attempts a detailed reconstruction of the lateglacial-holocene evolution of zelvianka river valley near piaski by considering new data and, following a critical evaluation of the literature. the new established pollen chronostratigraphies are, for the first time in the area, also supported by 14c readings. our results are of regional scale concern, as valleys developed at the ice sheet termini on limnoglacial sediments accumulated in ice-dammed lakes are common features in northern russian (kvasov, 1976, 1987) and masovian plains. methods a preliminary literature survey strongly suggested that further field work was needed for locating, checking stratigraphy and possibly re-sampling the reported profiles as well as selecting and sampling new key outcrops. samples for palynological analyses, collected at 5-8 cm intervals, were submitted to the standard chemical pretreatment (erdtman, 1936; pokrovskaya, 1950). the ap (arboreal pollen) + nap (non-arboreal pollen) sum, shrub species included, were considered. the percentages of other microfossils (pollen of aquatic taxa and spores) were calculated from ap+nap pollen sum. tilia and tilia-graph programs (grimm, 1992) were used for calculation and plotting, respectively. the chronozonal distinction, matching the criteria after mangerud et al. (1974), relied on both 14c dating and correlation with the 14c dated ap spectra from the sites of ogorodniki, morino, kremushovka and podbarany (vozniachuk and valchik, 1978; kalicki et al., 2000) located along the neman river valley near piaski site (fig. 1). radiocarbon dating was run with the liquid scintillation counting (lsc) technique on selected fractions of the organic matter in the sediment samples following decarbonation and removal of the mobile organics (calderoni and turi, 1998). details on the chemical and counting protocols, equipments, 14c decay rate measurement and age calculation were given elsewhere (calderoni and petrone, 1992). present-day environment the c. 170 km long zelvianka river begins between lidziany and kulyavichy villages and drains a 1940 km2 catchment with a 0.41 km/km2 river network density. river slope and annual discharge at the mouth average 0.41‰ and 11 m3/s, respectively. the natural 167river response to the holocene ... high sinuosity meandering channel, 15-20 m wide, is confined between steep, sandy banks. upstream of the study area two river sections (44.2 km long) have been channeled to supply water to the zelva and papiernia reservoirs. the valley broadens from 0.5 to 3-4 km in the lower reach and the flat flood plain, only recently reclaimed, is up to 2.5 km wide except for the middle and lower reaches, where it narrows to 0.4-0.6 km (blakitnaya kniga belorusi, 1994). the study area is 14 km upstream of the zelvianka river mouth to the neman river. at piaski gauge station the drainage basin accounts for 1800 km2 (mean altitude: 166 m a.s.l.), most being currently cultivated, 17% forested and 14% consisting of marshes, swamps and peat bogs. major forests, with pine communities (pinetum callunosum, pinetum vacciniosum) far predominant over fir, hornbeam and oak, spread along the right bank of zelvianka river to the north of piaski village. alnus glutinosa, betula pubescens, corylus avellana, salix lopponum and salix aurita grow in the lowermost swampy areas with peaty soil. dryopteris thelypteris, thelypteris palustris, filipendula ulmaria, comarum palustre, galium palustre and carex are the dominant herbs. fig. 2 shows the mean monthly, maximum and minimum discharge of zelvianka river since 1955 through 1975: the meltwater peak discharge in april points out the nival regime of the river. the mean annual discharge ranged from 18.9 to 6.59 m3/s (mean: 9.42 m3/s) and peaked at 289 m3/s in april 17, 1958. the water level during the spring floods is up to more than 2 m higher (mean: 676 cm) than the mean water stage (mean: 469 cm). the zelvianka river is yearly frozen during some 75 days, as an average from december 25 up to march 11-23 (gosudarstviennyy vodnyy kadastv, 1978). valley bottom structure along the 3 km long bifurcated reach of zelvianka river beginning 2 km upstream of piaski village the valley consists of two subparallel branches separated by an erosional remnant of the limnoglacial deposits on which the village lies at 116 m a.s.l. (fig. 3). the southern branch, narrower and straighter than the northern one, shows, in the left bank of the ending part, one confined paleomeander cutting the limnoglacial series. most of the studies were addressed to the northern valley branch for its well developed, up to 1 km wide flood plains. here fedenya et al. (1992) and kovbasyuk and ivanov (1998) recognized two and three steps, respectively, at 3.5 (4.0)-4.5, 2.0-3.0 and 1.0-1.5 m above river level (a.r.l.). upper flood plain remnants of this level, less than 200 m wide, are recorded on both valley sides by a fining-upward alluvia sequence (fedenya et al., 1992). the new field data, however, pointed out that the step height is morphology-dependent, thus implying that, for instance at piaski-2, the paleochannels are significantly lower (2.53.0 m a.r.l) relative to the point bars (4.5-5.0 m a.r.l.). further, the lag deposits were actually found at c. 1 m 168 a.r.l., not below the river water level as previously reported by kovbasyuk and ivanov (1998).only one among the profiles herein shown originated from the southern branch of the valley. southern valley branch piaski-mill this section (profile 11 after fedenya et al., 1985, 1992) is near the scarp of the valley, where the river cuts the piaski glaciodislocation and thus alluvia, only 3.6 m thick, overlies the chalk (fig. 3 and 4). mammal, amphibia and fish bones were found in the sands at 3.25 m deep. because the mammalian assemblage mirrors mixed and deciduous forests, meadow and aquatic biotopes and the frog bones steppe environment, it has been inferred that the sediment deposited at the southern limit of the forest zone. upward (2-3 m deep), a humified sandy layer contains entomofauna, similar to that of present times, that for including taxa of fast flowing water and stagnant or slowly flowing water (like in oxbow lakes with clay bottom) pinpoints the biotope varieties in the river valley. the occurrence of melolontha sp. suggested that sediments accumulated in the late atlantic, thus under warmer and drier climate than at present. based on the paleozoological data the alluvia was referred to the middle holocene. northern valley branch piaski-2 this new profile, c. 3 m a.r.l. and very close to the right scarp of the valley bottom, shows at the base a paleochannel fill overlain by sandy-silty overbank deposits (fig. 3 and 4). the former feature is made up by two units, the lower one (3.00-2.65 m deep), referred to the beginning of the infilling, consists of clastic sediments (clayey sands with gravels up to 0.5 cm), scattered organic matter and vegetal debris. the overlying organic sediments unit (2.65-1.10 m deep) displays, bottom to top, gyttja and peat. just upward a yellow-gray-green colored, rich in vegetal debris gyttja level is shown. the occurrence of thin layers and lenses of coarse sands and small gravels (up to 0.5 cm) in its lower part points to intermittent river/oxbow lake communication. the pollen spectrum for piaski-2 (fig. 5) shows that the gyttja bottom (2.65-2.45 m deep), dated at 10,670±100 yr bp (rome-1339), belongs to lpaz betula nana–pinus– nap. the high nap (17.5-25.5%), together with betula nana type, alnaster (alnus viridis), juniperus and scant selaginella selaginoides, reflects cold climate and openforest landscape. lemna and polygonum amphibium grew in the oxbow lake and phragmites, epilobium palustris and equisetum in the marshes. in the upward 30 cm of gyttja (2.45-2.15 m deep) lpaz changes into betula–pinus–salix-nap. here betula, pinus and salix increase and nap, attaining 28.5%, is dominated by artemisia. both polygonum amphibium and myriophyllum peaks reflect the ongoing overgrowing of the shallow (less than 3-4 m deep) lake. pollen data are consistent with a yd cooler and drier at the late stage (10,500-10,200 yr bp) than at its beginning. the lowermost 15 cm of the overlying gyttja silts (2.15-2.00 m deep), lpaz pinus, displays pinus predominance, ulmus first appearance and nap decline to a mere 5%. the disappearance of hydrophilous plants, paralleled by a rise of polypodiaceae, dryopteris thelypteris and thelypteris, marks the transition from shallow lake to peat bog. at first glance the comparison between the pollen spectra from piaski-2 and morino in the neman valley (vozniachuk and valchik, 1978) reveals an almost synchronous blooming of pine. in particular, at morino pine predominated prior to 9920±90 fig. 2 monthly maximum, average and minimum discharge of zelvianka river at piaski gauge station during the period 1955-1975 (by t. kalicki) t. kalicki, g. calderoni & v. zernitskaya 169 fig. 3 zelvianka river valley near piaski with study profile and geological section a-b (see fig. 8) (by t. kalicki) river response to the holocene ... 170 fig. 4 study profiles in the zelvianka river valley (by t. kalicki) 1 – chalk, 2 – gravel with sand, 3 – sandy gravel with clay, 4 – sand, 5 – eolian sand, 6 – organic sand, 7 – intercalation of sand and sandy silt,, 8 – sandy silt, 9 – intercalation of peat and sand, 10 – sandy peat, 11 – peaty silt, 12 – peat, 13 – intercalation of gyttja silt and sand, 14 – gyttja silt, 15 – gyttja, 16 – buried soil, 17 – soil, 18 – clayey ball, 19 – peaty ball, 20 – subfossil tree, 21 – detritus, 22 – bones, 23 – shells, 24 – remnant of insects, 25 – older pollen datings (references) reinterpreted by v. p. zernitskaya t. kalicki, g. calderoni & v. zernitskaya 171 fi g. 5 p ol le n d ia gr am o f t he p ia sk i 2 p ro fil e (b y v . z er ni ts ka ya ) 1 – g yt tja , 2 – g yt tja s ilt , 3 – p ea ty s ilt , 4 – p ea t, 5 – s an d , 6 – s an d w ith g ra ve l river response to the holocene ... and 9970±110 yr bp (mig-27 and tln-136, respectively), thus in agreement with the pb-1 (~10,200 – 9800 yr bp) established in zelvianka river valley. the topmost gyttja silts (2.00-1.84 m deep), lpaz betula-pinus-(ulmus), show increase of betula up to 55.3%, further rise of polypodiaceae, thelypteris and stable ulmus. these sediments were assigned to the pb-2 (9800-~9200 yr bp) by analogy with the reference pollen spectra from kremushovka and morino sites (vozniachuk and valchik, 1978), both recording the birch peak between 9920±90 and 9320±100 yr bp (mig-27 and mig-41, respectively). the lower part (1.84-1.70 m deep) of an overlying horizontal-bedded, compact peat layer, lpaz pinusbetula-(corylus), features betula drop, pinus and ulmus rise and appearance of corylus, quercus and alnus along with polypodiaceae predominance among the nap. this implies that the oxbow lake changed into a fern-covered swamp. the timing of a comparable ap spectrum (morino site, vozniachuk and valchik, 1978) spans from 8940±80 to 8590±90 yr bp (mig-28 and mig-29, respectively) and therefore the lpaz has been referred to __ (~9200-8000 yr bp). the upward (1.701.45 m deep) peat, lpaz ulmus-corylus-alnus, exhibits the peaks of ulmus (9.1%), corylus (18.6%) and alnus (20.%), expansion of quercus and tilia and subordinate fraxinus occurrence. the pollen spectrum, typical for at, fairly matches that for podbarany site (zernitskaya, 1999; kalicki et al., 2000). in the middle of the atlantic (1.60-1.55 m deep) the most humid climatic phase is marked by the hydrophiles lemna, thypha latifolia, nuphar lutea, numphaeae and myriophyllum as well as the hygrophiles menta longifolia and menyanthes trifoliata. the organic paleochannel fill ends with severely decomposed clayey peat (1.45-1.10 m deep). the abundant corroded pollen content and the frequent fluctuation of many taxa points to floods and unsteady humidity in the peat bog, now populated by ferns and subjected to pedogenesis. pollen data, though revealing a drop of ulmus and corylus and a rise of pinus, picea, quercus and tilia, were too meagre for any sound chronological assignment. however, the 14c reading (rome1341: 2085±60 yr bp) at the top of these sediments provides an ante quem terminus for their deposition. the bottom of the overbank deposits (1.10 m upward) capping the paleochannel fill displays, bottom to top, two sandy, 2 cm-thick layers overlain by a 12 cm-thick silty-sands layer, that is a suite likely mirroring an abrupt sedimentation change due to a flooding event. pedogenesis overshadowed the primitive structure of the topmost 80 cm of the upward intercalations of horizontally bedded sands and humified silty-sands. data suggest that the paleochannel was cut off at the alleröd/younger dryas transition and then, following fast gyttja accumulation during the younger dryas, the oxbow lake disappeared at the onset of the holocene. the organic paleomeander fill records the humid middle atlantic cl imatic phase. probably, at the subboreal/subatlantic transition the lowering of the ground water table triggered the weathering of the topmost peat. lastly, in response to the important sedimentation changes caused by floodings in roman times, the peat bog was buried by overbank deposits. piaski-10 this new exposure (fig. 3) shows the sandy level at c. 5 m a.r.l. and the paleochannels piaski-10 and -9 on the upper and middle flood plains, respectively (fig. 6). the former meander cut the higher sandy level and in turn was cut by the latter one. the height of the upper flood plain, less than 3 m in the paleomeander, rises to 4.5-5.0 m a.r.l. at the point bar. the bottom of the paleochannel fill is c. 1.5 m a.r.l. and channel medium sands occur at the base of the profile (fig. 6). the organic silty 172 fig. 6 section across the piaski 9-10 sites (by t. kalicki) and piaski 5 (levkov et al. 1988, modified by t. kalicki) 1 – limnoglacial sediments (intercalations of sand and silt), 2 gravel with sand, 3 – sand, 4 –eolian sand, 5– organic sand, 6 – organic silty sand, 7 – intercalation of sand and organic sandy silt,, 8 – sandy silt, 9 – organic sandy silt, 10 intercalation of peat and sand, 11 – sandy peat, 12 – peat, 13 – gyttja, 14 – lacustrine chalk, 15 – buried soil, 16 – soil, 17 – slump, 18 – iron concretion, 19 – subfossil tree, 20 – detritus, 21 – charcoal, 22 – bones, 23 – shells, 24 – flint artifact, 25 – samples for palaeobotanical macroremnant study, 26 – palaeobotanical dating, 27 – radiocarbon dating; al – alleröd, yd – younger dryas, pb – preboreal, at – atlantic, sb – subboreal t. kalicki, g. calderoni & v. zernitskaya sands (meadow ore) at the bottom of paleomeander fill were dated at 9270±90 yr bp (rome-1337). upward, following a level of lacustrine chalk with bithynia tentaculata pointing to an ephemeral oxbow lake, meadow ore accumulated again. the topmost 0.5 m of the profile consists of overbank silty sands. the early holocene abandoned channel was close enough to the zelvianka river to prevent any subsequent organic accumulation in the paleomeander. piaski-5 this exposure (fig. 3) has been reported (levkov et al., 1988) as a thermokarstic depression infilled by two age-distinct series of alluvia capped by aeolian sands (fig. 6). subfossil pine trees, up to 3 m long, were found in the cross bedding sands and gravels at the bottom of the fill (fig. 6, profile 1). based on the vegetal macroremnants both channel deposits and overlying sandy overbank sediments were dated to the late glacial/preboreal transition. in turn, the depression fill (fig. 6, profile 2) made up by gravel with sands and peats was subsequent, as pointed out by preboreal/ boreal mammal bones (ivanov, 2001) at the bottom of the lag deposits and vegetal macro-debris of the middle and late atlantic mixed forest in the overlying sediments (levkov et al., 1988). both alluvial members are topped by aeolian sands that, for containing at least three paleosols, did deposit intermittently. the sands contain flint tools, likely used for quarrying the chert in the glaciodislocated basement close to piaski some 3400-3200 yr bp (gurina, 1976). however, the previously claimed thermokarstic origin of the depression has to be rejected for two sound reasons. first, the limnoglacial deposits could not accumulate during the maximum expansion of the valday ice sheet (thus, while zelvianka river was frozen) and further, a re-examination of the outcrop revealed two age-distinct paleomeanders cut in the limnoglacial series (fig. 6). thus, the channel deposit underlying the paleomeander fill consists of two diachronous alluvial bodies instead of only the one previously claimed. in addition the top of the late glacial channel facies is 2 m a.r.l. and the older paleomeander cut the limnoglacial series. thus, the slumps on the scarp of the river valley do actually record bank erosion, in analogy with that reported from vistula valley (wasylikowa et al., 1985), rather than thermokarstic processes. the pine trees fallen during the late glacial lateral migration of zelvianka river accumulated in the sandy-gravels deposits. the older paleochannel cut off at the late glacial/holocene transition and in the preboreal was quickly infilled by sandy sediments containing a rather homogeneous assemblage of vegetal macroremnants (fig. 6, profile 1). during the early holocene the younger meander undercut and partly destroyed the fill of the older, abandoned channel, then it was cut off in the middle atlantic. in the late atlantic, following its fast infilling by sands (fig. 6, profile 2), the younger oxbow lake changed into a peat bog. during the subboreal and subatlantic both paleomeanders were covered with aeolian sands in a few phases. the flint artifacts in the buried soils could suggest that human impact played some role in the recurrent aeolian activity. piaski-4 the profile (ivanov and yelovicheva, 1997; ivanov, 2001) is located on a narrow, 10 to 50 m wide, remnant of the upper flood plain, 3.5-4.5 m a.r.l. (fig. 3). basal channel sands with gravels contained well preserved, likely in situ, bones of amphibia, fish and mammals (typical of taiga coenoses) with some tundra species probably of the preboreal/boreal transition (fig. 4). the upward sandy paleochannel fill (3.6-2.9 m deep) is overlain by sandy overbank deposits 1.8 m thick. pollen data point to a continuous sedimentation from the second half of the preboreal through the first half of the subboreal. an overlying silty-sandy buried soil (1.1-0.6 m deep) was assigned to the second half of the subboreal and the aeolian fine sands capping the sequence to the subatlantic by the pollen data. in our opinion, however, the above conclusions are puzzling. actually, the claimed continuous sedimentation from the preboreal through the present is ruled out by paleosol occurrences. further, it is also well known that alluvia is deposited by meandering rivers mostly according to an horizontal rather then a vertical pattern. in addition, no firm conclusions can be drawn from the reported pollen spectrum that for having been determined on sands (also including a paleosol) and for lacking the pollen/corroded pollen ratio, prevents any hiatus recognition. by comparing the piaski-2 and -4 palynostratigraphies it results that the latter lacks the lpaz’s betula-pinus-(ulmus), pinus-betula-(corylus) and ulmus-corylus-alnus, despite all of them all of them are quite evident since pb-2 to the end of at in the piaski-2 pollen spectrum. the lpaz’s pinusquercus, betula-quercus with tilia, carpinus and fagus displayed in the piaski-4 pollen spectrum are typical for the subboreal in belorussia (zernickaja, 1998, zernitskaya, 1999), eastern poland (ralskajasiewiczowa and latalowa, 1996) and southerneast lithuania (kabailiene, 2002). both literature and new data (e.g., piaski-1 profile) constrain the deposition of the piaski-4 sediment suite (fig. 4) within the sb (4.11.7 m deep) and sa (1.7 m-upward). piaski-3 this profile (ivanov, 1993), c. 3.0 m a.r.l. shows basal loams overlain by sandy alluvia (fig. 3, 4). the lower portion (2.5-2.8 m deep) of subhorizontal bedding sandy-gravel channel alluvia contains well preserved, likely in situ, mammal bones pointing to widespread humid mixed forest. palaeozoological and palynological data were judged consistent with a continuous sedimentation during the last 8000 yrs (from at-1 to sa-3). however, the previous criticisms for piaski-4 also apply here, as the reported pollen spectrum, besides depicting only the ap trend, does not show the pollen amounts. akin to piaski-4, as the pollen diagram lacks the at (ulmus-corylus-alnus) while showing both sb and sa chronozones, it is reasonable that piaski-3 sequence deposited since the subboreal. this is also supported by new malacological data (predominance of channel species over those of different biotopes) from the 0.75-3.1 m deep sandy deposits, consistent with alluvia accumulation from the atlantic to the subatlantic (a. f. sanko, pers. comm., 2002). 173river response to the holocene ... 174 fi g. 7 p ol le n d ia gr am o f t he p ia sk i 1 p ro fil e (b y v . z er ni ts ka ya ) 1 – g yt tja s ilt , 2 – p ea t, 3 – s an d y p ea t, 4 – s an d y si lt, 5 – s an d , 6 – s an d w ith g ra ve l t. kalicki, g. calderoni & v. zernitskaya middle flood plain according to kovbasyuk and ivanov (1998) the middle flood plain is built of sandy overbank deposits rich in vegetal remnants and detritus and devoid of subfossil tree trunks. the overbank/channel sediments boundary lies below the mean river water level. oxbow lakes were filled with humic sands 0.5-1.5 m thick and, sometimes, with peat intercalations up to 1.5-1.8 m thick. contrasting with the previously stated absence of slope and aeolian deposits, new field work at piaski-1 identified thick aeolian sands covers. all the studied profiles herein reported are from the northern branch of the valley. piaski-1 this exposure (fig. 4, profile 5) was referred to the upper flood plain for lying above the river level (fedenya et al., 1985, 1992). by contrast, the new survey established that the topmost 2 m of the sequence are aeolian sands and thus the shown features do belong to the middle flood plain (fig. 3 and 4). at the base of the channel deposits (4.22-4.67 m deep) an assemblage of likely in situ bones of mammals (mostly of mixed and deciduous forests, 25 and 17% of lake banks and meadows, respectively), amphibia of mixed and deciduous forests of middle holocene age and fish were found. the entomological assemblage from the organic paleochannel fill includes species of fast flowing waters together with those of stagnant or slowly flowing waters (as in oxbow lakes with clay bottom) and mirrors the variety of biotopes in the river valley during the middle holocene. at piaski-1 a new, 14c dated pollen diagram has been determined as that previously available placed at the atlantic-early subboreal the peat in the paleochannel, thus in open contrast with the up to date regional palynologic framework (zernitskaya et al., 2003), the sampled exposure shows, bottom to top, four main members including channel deposits, organic paleochannel fill, sandy-silty overbank deposits and aeolian sands (fig. 3 and 4). the basal member, c. 0.5 m thick, consists of medium and coarse sands and correlates with the layer with fossil bones after fedenia et al. (1992). the transition to the overlying paleochannel fill is marked by a lamina of lag deposits (gravels 0.2-0.3 cm in diameter) covered with a 0.5 cm-thick lamina of peaty silts and a 15 cm-thick layer of medium and coarse sands. the upward organic paleochannel fill, submitted to pollen and 14c analyses, shows a 0.5 m-thick gyttja silts (lpaz pinus-quercus at 3.95-3.85 m deep), overlain by 0.7 m-thick peats (fig. 7). the lowermost 5 cm of the gyttja silts, sandy and densely laminated, suggest some river input into the oxbow lake. the lack of sandy intercalations through the upward c. 10 cm points to low sedimentation energy and rules out flood events. the ap pinus and quercus predominate over picea, tilia and carpinus. nuphar, sparganium and typha latifol ia grew in the oxbow lake and polypodiaceae, sphagnum in the marshes. the bottom of this early subboreal (sb-1) pollen chronozone was dated at 4105±60 yr bp (rome-1338). it is noted that a comparable pollen spectrum was reported from podbarany site (kalicki et al., 2000) for sediments younger than 4645±50 yr bp (igsb-709). the lacustrine episode of the paleochannel with gyttja silts accumulation lasted up to the end of the subboreal (lpaz betula-quercus-carpinus, 3.85-3.35 m deep). a few sandy laminae in the middle of the gyttja silts record episodic oxbow lake/river contacts. pinus drop parallels the rise of betula, alnus, tilia (6.6%), quercus (20%) and carpinus (2.6%) whereas fagus is far subordinate. the rare hydrophyte typha latifolia indicates a water depth less than 0.5 m. a comparison with the ogorodniki pollen diagram, showing that tilia, quercus and carpinus maximize between 3820±100 and 3530±100 yr bp (tln-163 and mig-44, respectively) and decline between 3530±100 and 2720±90 yr bp (mig-44 and mig-43, respectively), dates these sediments to the sb-2 and sb-3 (~4000-2700 bp). at c. 3000 bp the oxbow lake changed into a marsh where the intermittent grow of trees is recorded by subfossil trunks in the peats. the peat layer includes two sandy peat intercalations. the lower one spans through the uppermost part of lpaz betula-quercus-carpinus, characterized by decrease of pinus, expansion of pioneer vegetation (betula and alnus in deforested areas) and viburnum, sambucus and calluna occurrence. nap in sb-3 sediments (3.50-3.35 m deep) reaches 10% and includes scleranthus, helianthemum and brassicaceae. the rise of xerophytes and heliophytes, e.g., artemisia, chenopodiaceae, cichoriaceae, umbelliferea and asteraceae is matched by poaceae, fagopyrum and urtica dioica appearance. despite the lack of cultural species, the apparent deforestation could be accounted for, at least to some extent, by human impact, in that archaeologic sites of the neman and trzciniec cultures (late neolithic and bronze age, respectively) are known nearby piaski village (charnyavski, 1979; arkhialogiya belarusi, 1997). it is reasonable that following the local pine forests clearance for wood exploitation and flint quarrying in the glaciodislocated chalk, the wind blown sands originated from the deforested areas mixed up with the peat growing in the paleomeander. the concomitant humid climate, recorded by rise of polypodiaceae and picea (up to 5%) and abies occurrence, resulted in trees fallen on the peat bog, where subfossil trunks were found at the silty gyttja/peat limit. probably also the sandy intercalation reported by fedenya et al. (1992) in the paleochannel fill were laid down from the same flood phase (fig. 4). the upward sediments of lpaz pinus-quercusalnus (3.35-2.90 m deep), dated to 2700-1200 bp, show pinus rise, high quercus (8.4%) and alnus (47%), tilia decline and carpinus disappearance. nap are dominated by polypodiaceae. some sediment samples from 3.25-3.10 m deep were very low in pollen for the alternating peat and sandy laminae were severely affected by erosion and undulation. at 3.20-3.15 m depth polypodiaceae increases and the hygrophytes sphagnum, mentha longifolia and rubiaceae are weakly, though significantly, represented. the subfossil trunks, 15 to 20 cm in diameter, at the boundary between the laminated layer and the overlying peats (fig. 4) mark a further phase of trees fallen on the peat bog caused by increased humidity. all the above features, along with the lack of human activity pollen 175river response to the holocene ... markers, point out an enhanced flood frequency during the humid climatic phase in roman time (c. 2000 bp). tentatively, also the second sandy intercalation reported from the paleochannel fill by fedenya et al. (1992) could be correlated with this flood phase (fig. 4). the uppermost peats (lpaz pinus-picea-corylus, 2.90-2.75 m deep) display scant ulmus and carpinus, expansion of pinus, picea and corylus, decline of quercus robur and desappearance of q. petraea. the picea peak (11.4% at c. 1000 yr bp) records a cooler and more humid climate. the higher humidity in the peat bog is also supported by the occurrence of sparganium, typha latifolia, nuphar and the algae pediastrum. the re-appearance of artemisia, brassicaceae, cichoriaceae, poaceae, calluna and centaurea cyanus along with the peak of corylus indirectly reflect the human presence. probably the exploitation of the deciduous wood contributed to spread the hazel. frequent floods, triggered by climate fluctuations, significantly changed the sedimentation pattern in the paleochannel and the peat growth, definitely over at 885±50 yr bp (rome-1340), was substituted for by accumulation of horizontal bedding, sandy-silty overbank deposits. these latter, up to 1 m in thickness, were blanketed during the last centuries by c. 1.8 m of aeolian sands and podsol developed at their top (fig. 4). the new findings contrast with some conclusion after fedenya et al. (1985, 1992). based on the mammalian assemblage the channel, active during the late atlantic/subboreal transition, was cut off at c. 4200 bp. despite of that the sandy intercalations in the organic sediments point out that episodic oxbow lake/river channel interactions did last over further hundred years. the signature of two humid climatic phases in the paleochannel organic fill (c. 3000 and c. 2000 bp) is provided by re-appearance of hydrophile taxa, trees fallen and sedimentation change in the peat bog. then, a further flood phase (c. 885 yr bp) caused the peat bog burial by overbank deposits. the forest clearing recorded by pollen data at c. 3000 bp likely reflects the impact of the neman culture settlements. however, it is reasonable that the origin of the thick cover of aeolian sands on the middle flood plain near the valley scarps only depended upon the extensive forest exploitation during the last centuries. piaski-bridge the section (fedenya et al., 1992) displays middle-coarse sands with detritus overlain by peats and sands (fig. 3 and 4). previous palaeobotanical and palaeoentomological data bracket the origin of the paleochannel peats between the second half of the atlantic and the beginning of the subatlantic. the new pollen spectrum for piaski-2 (fig. 5) conflicts with the previously stated timing of betula decline and corylus appearance and set the cut off at the boreal/atlantic boundary. further, the important sedimentation change marked by the sudden appearance of fine, humified sands in the upper part of the sequence (fig. 4, profile 1), previously placed at the subboreal/ subatlantic limit by the picea peak, is more reliably 176 fig. 8 geological section a-b (see fig. 3) of the study area (i) and schematic profile (ii) across the zelvianka river valley near piaski (by t. kalicki) 1 – bedrock (tilt with glaciodislocated chalk), 2 – limnoglacial serie with slump, 3 – gravel with sand, 4 – sand, 5 – eolian sand, 6 – intercalation of sand and sandy silt, 7 – sandy silt, 8 – intercalation of sand and organic sandy silt, 9 – organic sand, 10 – organic sandy silt, 11 – intercalation of peat and sand, 12 – sandy peat, 13 – peat, 14 intercalation of sand and gyttja silt, 15 – gyttja silt, 16 – gyttja, 17 – buried soil, 18 – subfossil trees and detritus, 19 – bones, 20 flint artifacts, 21 – palaeobotanical, palaeozoological and archaeological datings, 22 – radiocarbon datings; al – alleröd, yd – younger dryas, pb – preboreal, bo – boreal, at – atlantic, sb – subboreal, sa subatlantic. t. kalicki, g. calderoni & v. zernitskaya dated at c. 1000 bp by the spruce maximum shown in both the previous pollen diagrams for this profile and in the new one from piaski-1 (fig. 7). piaski-9 the overall features of this new section (2.2.-2.5 m a.r.l.) are as for piaski-10 (fig. 3 and 6). the fine sands at the bottom of the paleochannel fill change upward into organic sediments, with a gyttja layer, dated at 3245±60 yr bp (rome-1342), at the base. through the upward 80 cm a regular alternation of a few mm thick, brown and whitish laminae is shown. the former ones, rich in organic matter, deposited during the vegetational seasons whereas the latter ones, made up by fine sands, during the spring floods. in our knowledge such an evidence of seasonal sedimentation change in paleomeanders was never reported. as the frequency of the laminae pairs is from 5 to 7 cm-1, it can be estimated that the whole member deposited in some 500 yrs. such peculiar lamination is overlain by sands with silty-sands intercalations. paleogeography the origin of zelvianka river valley dates back to the disappearance of the dammed skidel lake in the young pleniglacial, just after the pomeranian stage of the last glaciation dated to 16.2 (kozarski, 1995) and 15.5-15.0 ka bp (valchik, 1992). the incision of neman river and its tributaries on the upper neman plain was over in middle lithuanian stage of deglaciation (13.813.7 ka bp, valchik, 1992), when zelvianka river bifurcated near piaski and meanders, still well preserved downstream of the study site, were confined. the young pleniglacial incision of the limnoglacial sediments was so fast that the bottom level of the late glacial paleomeanders (e.g., piaski-2, -5 and -10) approach those of their holocene analogues (fig. 8). the vegetal macrofossils from the channel deposits (piaski-5) date the upper flood plain at the alleröd. a fast incision, followed by a relative stabilization, was also reported from the main neman river valley, where the terrace t-1 and the upper flood plain formed during the late glacial and the early holocene, respectively (vozniachuk and valchik, 1978). during the younger dryas the highlands were covered by pine-birch-juniper open forests, the humid lows by spruce and dwarf birch (betula nana) and the open lands by xerophyte grass communities. the climate cooling forced changes of zelvianka river course and the cut off occurred at the alleröd/younger dryas transition (e.g., piaski-2, 10,670 bp). evidence of river braiding, lateral migration and valley widening are the relatively shallow paleochannels (with subfossil trunks in their fills) that while undercutting caused slumps on the slope of the northern branch of the valley (piaski-2 and -5). probably some river aggradation took place, as the bottom of the river bed rose from c. 0.5-1.0 to c. 1.5 m a.r.l. from the younger dryas to the end of the preboreal (fig. 8). willows as pioneer taxa grew on the new bars of the alluvial plain and also around the oxbow lakes. these latter experienced a highly variable rate and pattern of sedimentation (e.g., fast gyttja accumulation at piaski-2 or slow deposition of sands with detritus at piaski-5). the overall climate warming at the onset of the preboreal is marked by vegetation changes, e.g., spreading of pine forests on the highlands and elms on zelvianka flood plain. some paleochannels (piaski-5) were filled up quickly with sandy sediments containing detritus. at the end of the preboreal (pb-2) the region was covered with birch, pine-birch and elm forests. the shallow paleochannel piaski-10 was cut off at c. 9270 bp. the evolution of zelvianka river bed, as well as the lack of incision likely depended upon the relatively dry climate. elm rise, oak and hazel first appearance, increased the heterogeneity of the mixed forests and development of alder and fern patches on the humid flood plain took place in the boreal. an incision phase of the river at the beginning of the boreal is suggested by the mammal bone assemblages from the channel deposits of the middle flood plain, dated at the preboreal/boreal transition (piaski-4 and -5) and at the onset of the atlantic (piaski-3). likely, the event was caused by a wave of headward erosion originated in the neman valley on the middle neman plain, about 100 km downstream of the study area, prior to the older dryas (kalicki, 2002; kalicki et al., 2002). however, the middle holocene age of the bones from the channel deposits of the 1.5 m high borodnichanka valley bottom in the volkovysk upland (fedenya and kalinovskiy, 1981) points out that the regressive incision reached the upper section of the zelvianka tributaries just in the neoholocene. the cutting, coupled with the improved drainage of zelvianka upper flood plain, changed the former oxbow lakes into peat bogs at c. 9000 bp (piaski-2). in turn, the ephemeral lakes with gyttja accumulation in the preboreal abandoned channels were substituted for by marshes with meadow ore formation (piaski-10) just after 9270 bp. the oldest paleomeanders of the middle flood plain cut off at the boreal/atlantic transition (piaski-bridge) and the bottom height of their fillings equalled the present river water level (fig. 8). reasonably the channel changes were triggered by the humid and cooler climatic phase at the boreal/atlantic transition previously reported from central european river valleys and other environments (starkel et al., 1996; starkel, 2000). in the atlantic pine forests with birch there were confined in the poorest sandy soils, deciduous forests with hazel, elm and subordinate oak, lime and ash spread on the fertile flood plain. and alder and fern occurred in humid sites. the lateral river migration destroyed, completely or partly, some older paleochannel fills (piaski-5). then, in the middle atlantic the younger piaski-5 paleomeander was cut off and fast infilled with sands. both channel changes and a fast sedimentation rate point to frequent floods during the humid climate phase revealed by piaski-2 pollen diagram. this climate trend is consistent with the c. 6420 bp humid phase in the neman valley (kalicki et al., 2000) and the c. 6500-6000 bp climate cooling and increased river activity in the vistula river valley (kalicki,1991b, 1996a; starkel et al., 1996). the bones of middle holocene age from the channel deposits of the southern branch of zelvianka valley (piaski-mill) suggest that since the end of the atlantic only the northern branch was active. the 177river response to the holocene ... late atlantic drier climate, argued from the palaeozoological data from piaski-mill, accounts for the abandonment of the southern valley branch in response to the decreased river discharge. accordingly, the late atlantic/subboreal bones in the channel river facies of the paleomeander undercutting the valley slope at piaski-1 support a widening of the active northern branch of the river valley. in some paleochannels (e.g., piaski-5) the late atlantic increased fluvial activity changed the sedimentation pattern from organic into clastic. climate cooling at the beginning of the subboreal deteriorated the elm forests which were progressively substituted for by oak-pine forests. despite that at c. 4195 bp the meander was cut off at piaski-1, the sandy layers intercalated in the organic fill of the paleomeander reveal that some river/oxbow lake communication did still last over some hundred years. the modern vegetation subzone (carpineto-querceto-pinetum forest) began to develop during the 4000-2700 bp timespan. hornbeam, spruce, beech, birch and alder expanded whereas pine declined. contemporary is the first evidence of settlements, referred to late neolithic (neman culture) and bronze age (trzciniec culture). likely, the local anthropogenic impact resulted in spreading of bush (sambucus, viburnum, rubus), rural and grasslands taxa (piaski-1) and aeolian processes development. in the subboreal and the subatlantic the deposition of wind blown sands, interrupted by pedogenetic phases, covered both flood plain steps near the edge of the valley bottom (piaski-5, -4 and -1). flint artifacts and charcoal from the paleosols (piaski-5) support that the aeolian activity was triggered by the human impact. a humid climatic phase at c. 3000 bp, implying re-appearance of hydrophilous taxa, fallen trees and sedimentation change in the peat bog, was recognized at piaski-1 in the paleochannel organic fill. despite of some anthropogenic overshadowing, this climatic phase is reliably marked by a rise of spruce, appearance of fir in the forests and also by channel changes at 3245 bp (piaski-9). as this phase of enhanced river activity matches those reported from other river valleys in belorussia (kalicki, 1991a; kalicki et al., 1997a, 2000) and central europe (kalicki, 1991b, 1996b) it is better accounted for by significant, large-scale climatic changes (kalicki, 1995, 1996a) rather than the local forest clearing at c. 3000 bp. in the subatlantic (2700-1200 bp) quercus petraea and carpinus disappeared and declined, respectively, in the carpineto-querceto-pinetum forests, whereas alder spread on the flood plain. the subatlantic incision which formed the lower flood plain also deepened the ground water table and thus pedogenesis developed atop the peat bogs on the upper flood plain (piaski-2). the neighborhood of the river, with steady regime and spring floods since the onset of the subatlantic, is witnessed by a series of laminated sediments in the late subboreal abandoned channel (piaski-9). in the roman time (c. 2000 bp) a distinct humid phase is marked by re-appearance of hydrophyte taxa and occurrence of subfossil trees (piaski 1) in the paleochannel organic fill, while both the flood plain higher steps were inundated. the floods are marked by sandy intercalations in the paleochannel fill on the middle flood plain (piaski-1) and sedimentation changes in the abandoned channel on the upper flood plain. here the peat bog was covered with overbank deposits at c. 2085 bp (piaski-2). a further cool and humid climatic phase at 1200-800 bp is suggested by spruce and hazel rise and oak decline. the hydrophilous taxa in the peats from piaski-1 paleomeander point to some input of flooded pollen: then, at c. 885 bp, the peat bog was buried by overbank deposits. almost contemporary (c. 1000 bp) is the burial of the peats by clastic deposits in the abandoned piaski-bridge channel. these two flood phases, likely triggered by climatic changes (kalicki 1996a), are also known from other belorussian (kalicki 1991a, 1995, kalicki et al., 1997b, 2000, kalicki and sanko, 1998) and central european river valleys (kalicki, 1996b, starkel et al., 1996). their identification relied on channel changes (meander cut-offs and avulsions), sedimentation pattern changes on the flood plains (beginning of peat aggradation, peats and soils burial by overbank deposits, abundant tree trunks in alluvia, etc.). based on the above it is inferred that the local forest clearing can only account for the subatlantic aeolian activity which originated the paleosol at piaski-4. conclusions the new 14c dated pollen diagrams from zelvianka river valley and the up to date palynostratigraphic framework for belorussia (zernickaja, 1998, zernitskaya, 1999) pointed out the need to revise the previous pollen chronostratigraphies (fedenya et al.,1992; ivanov, 1993; ivanov and yelovicheva, 1997). most important, it has been pointed out that the atlantic is hardly recognized only by the deciduous taxa peak, hornbeam and beech included. the rejuvenation of the drainage network on the upper neman plain and the lowering of the level of the skidel dammed lake, caused by the vistulian ice-sheet retreat, were almost coeval . the fast young pleniglacial incision also propagated in other river valleys developed at the ice sheet front (kalicki et al., 1997b). thus, the zelvianka river level was almost steady from the late glacial through the holocene. akin to western dvina river valley on the surash plain (kalicki et al., 1997b), the study area is too far from the sea coast to correlate the young pleniglacial, boreal/atlantic and the subatlantic phases of zelvianka river incision with the baltic sea level changes as previously claimed (kovbasyuk and ivanov, 1998). the first two headward erosion phases caused by deglaciation were delayed and smoothed relative to the main neman river valley, thus resulting in small height differences among the three zelvianka river flood plains. the extremely complex structure of the valley bottom depended mostly on the lateral migration of zelvianka river during the holocene. impressively, almost each morphological level with paleomeanders includes numerous, age-distinct alluvial bodies. both channel and sedimentation changes in zelvianka river valley cluster at al/yd transition, c. 9300 bp, bo/at transition, middle atlantic, c. 4200 bp, c. 3250-3000 bp, roman time (2100 bp) and 1000-900 bp. most of these events, likely triggered by the lateglacial and holocene humid and cool climatic phases, fairly match episodes of enhanced river activity in belorussia and central europe. the only noticeable 178 t. kalicki, g. calderoni & v. zernitskaya effect of the human impact on the evolution of the zelvianka river valley is the activation of aeolian processes in deforested areas during the subboreal and subatlantic. references arkhialogiya belarusi 1997 t. 1, minsk. blakitnaya kniga belarusi. encyklapedyya 1994 belaruskaya encyklapedyya, minsk. calderoni, g. and petrone, v. 1992: department of earth sciences at the university of rome radiocarbon dates i. radiocarbon 34(1), 105-113. calderoni, g. and turi, b. 1998 major constraints on the use of radiocarbon dating for tephrochronology. quaternary international 47/48, 153-159. charnyavski, m.m. 1979 nealit belaruskaga panyamonya. minsk. erdtman, g. 1936 new methods in pollen analysis. sven. bot. tidsskr. 30, 154-164. fedenya, w.m. and kalinovskiy, p.f. 1981 geologicheskiye i paleoteriologicheskiye issledovaniya na territorii volkovysskoy vozvyshennosti, doklady an bssr, 25, 12, 1124-1127. fedenya, w.m., kalinovskiy, p.f. and nazarov w.i. 1985 geologicheskiye i paleozoologicheskiye issledovaniya u d. peski na r. zel’vyanke. doklady an bssr, 29, 3, 260-262. fedenya w.m., kalinovskiy p.f. and rylova t.b. 1992 o vozraste i usloviyakh formirovaniya poymy zel’vyanki. in makhnach, n.a. and jakubovskaya, t.w., editors, flora i fauna kaynozoya belorussii. minsk, 11-22. gorecki, g.i. 1980 osobennosti paleopotamologii lednikovykh oblastey (na primere belorusskogo poneman’ya). minsk. gosudarstviennyy vodnyy kadastr. osnovnyye gidrologicheskiye kharakteristiki. t 5 belorussiya i verkhnieye podneprov’e 1978 gidrometeoizdat. leningrad. grimm, e.c. 1992 tilia and tilia graph: pollen spreadsheets and graphics programs. program and abstract of the 8th international palynological congress. aix-en-provence, france. 1992, 56 p. gurina, n.n. 1976 drevniye kremnedobyvayushchiye shakhty na territorii sssr. leningrad. ivanov, d.l. 1993 novaya nakhodka melkikh mlekopitayushchikh belarusi. in priroda belarusi i problemy ee ochrany, minsk, 118-121. ivanov, d.l. 2001 o faunie melkikh mlekopitayushchikh rannego golocena razreza peski-5 na reke zel’vianka. sovremennyye problemy estestvoznaniya, 106-109. ivanov, d.l. and yelovicheva, j.k. 1997 asablivasci razviccya galacenavykh biyacenozav dalin rek zyal’vyanki i svislachy. vesci belaruskaga dzyarzhavnaga pedagagichnaga universiteta 1, 82-89. kabailiene m. 2002 ozera ugo-vostochnoi litvy i ikh okruzashchaya sreda v pozdnem lednikovie i golocene po dannym diatomovogo i pylcevogo analiza otlozenii. in lopuh, p.s. editor, prikladnaya limnologiya. vyp. 3, minsk, 123-132. kalicki, t. 1991a budowa teras i wiek równiny zalewowej berezyny ko lo borysowa (bia loruś). przeglad geograficzny 63, (3-4), 362-376. kalicki, t. 1991b the evolution of the vistula river valley between cracow and niepo lomice in late vistulian and holocene times. in starkel, l. editor, evolution of the vistula river valley during the last 15 000 years, part iv. geographical studies, special issue no. 6, 11-37. kalicki, t. 1995 lateglacial and holocene evolution of some river valleys in byelorussia. in frenzel, b. editor, european river activity and climatic change during the lateglacial and early holocene . paläoklimaforschung 14, 89-100. kalicki, t. 1996a climatic or anthropogenic alluviation in central european valleys during the holocene. in branson, j., brown, a.g. and gregory, k.j. editors, global continental changes: the context of palaeohydrology. geol. soc. special publ. 115, the geological society, london, 205-215. kalicki, t. 1996b phases of increased river activity during the last 3500 years. in starkel, l. and kalicki, t. editors, evolution of the vistula river valley during the last 15 000 years, part vi. geogr. stud. special iss. 9, 94-101. kalicki, t. 2002 transformacja systemu fluwialnego niemna u schy lku plejstocenu. abstract of symposium transformacja systemów fluwialnych i stokowych w późnym vistulianie i holocenie. 2527.09.2002 lóźdz-uniejów, 15-17. kalicki, t., litwinjuk, g.i., sańko, a.f., szalabuda, w.l., zernickaja, w.p., komarowski, m.e., kalkowski, w.m. and pawlawa, i.d. 2000 dolina niemna na nizinie górnoniemeńskiej. in papers of symposium problemy paleogeografii późnego plejstocenu i holocenu, materialy bia lorusko-polskiego seminarium. wycieczki terenowe 26-29.09.2000, grodno, bialorus, 110-123. kalicki, t. and sanko, a.f. 1998 palaeohydrological changes in the upper dneper valley during the last 20,000 years (belarus). in benito, g., baker, v.r. and gregory, k.j. editors, palaeohydrology and environmental change, chichester, wiley, 125135. kalicki, t., sanko, a.f. and litvinjuk, g.i. 1997a zapis późnoglacjalnych i holoceńskich zmian klimatu i dzia lalności czlowieka w osadach dna i zboczy doliny ptyczy kolo mińska. in kalicki, t. editor, badania ewolucji dolin rzecznych na bialorusi. i, dokumentacja geograficzna 6, 83-104. kalicki, t., sanko, a.f., zernicka, v.p. and litvinjuk g.i. 1997b ewolucja doliny dźwiny na nizinie suraskiej w późnym glacjale i holocenie. in kalicki, t. editor, badania ewolucji dolin rzecznych na bialorusi i, dokumentacja geograficzna 6, 13-52. kalicki, t., zernitskaya, v.p. and simakova, g.i. 2002 late glacial–early holocene development of the niemen valley near goza (belarus). field symposium on quaternary geology and geodynamics in belarus. 20-25.05.2002 grodno, 22-23. kovbasyuk, t.g. and ivanov, d.l. 1998 osobennosti stroyeniya i istoricheskogo razvitiya doliny reki zel’vianki. aktual’nyye problemy estestvoznaniya, 42-47. 179river response to the holocene ... kozarski, s. 1995 deglacjacja pólnocno-zachodniej polski: warunki środowiska i transformacja geosystemu (~20ka ➝ 10ka bp), dokumentacja geograficzna 1. kvasov, d.d. 1976 paleogidrologiya vostochnoy yevropy v valdayskoye vremia. in problemy paleogidrologii, moskwa, nauka, 260-266. kvasov, d.d. 1982 the late quaternary history of the volga river. in paleohydrology of the temperate zone i, rivers and lakes, 43-55, tallin. levkov, e.a. 1980 glaciotektonika, minsk. levkov, e.a., ljudwig, a.o. and karabanov, a.k. 1988: o roli termokarstowykh processov v formirovanii gidroseti i vremeni ischeznoveniya mnogoletnemerzlykh porod na territorii belorussii. doklady an bssr, 32, 4, 343-346. mangerud, j., andersen, s.t., berglund, b.e. and donner, j.j. 1974 quaternary stratigraphy of norden, a proposal for terminology and classification. boreas 3, 109-128. pokrovskaya, i.m. 1950 pyl’tsevoi analiz,. moskva. ralska-jasiewiczowa, m. and lata lowa m. 1996 poland. in: berglund, b.e., birks, h.j.b., ralskajasiewiczowa, m. and wright, h.e. editors, palaeoecological events during the last 15,000 years. chichester, 403-472. starkel, l. 2000 8500-8000 yrs bp humid phase – global or regional? science reports of tohoku university, 7th series, geography, 49, 2, 105-133. starkel, l., kalicki, t., krapiec, m., soja, r., gebica, p. and czyz·owska e. 1996 hydrological changes of valley floor in the upper vistula basin during late vistulian and holocene. in starkel, l. and kalicki, t. editors, evolution of the vistula river valley during the last 15 000 years, part vi, geogr. stud., special iss. 9, 7-128. wasylikowa, k., starkel, l., niedzia lkowska, e., skiba, s. and stworzewicz, e. 1985 environmental changes in the vistula valley at pleszów caused by neolithic man. przeglad archeologiczny 33, 19-55. valchik, m.a. 1992 razvitie dolinno-rechnoy seti belorussii i pribaltiki v sviazi s degradaciey valdayskogo lednikovogo pokrova. in. shirokov l. m. editor, gidrographicheskaya set’ belorussii i regulirovanie rechnogo stoka. minsk, universitetskoye, 3-10. vozniachuk, l.n. and valchik, m.a. 1978 morfologiya, stroyenie i istoriya razvitiya doliny nemana w neoplejstocene i golocene, minsk. zernickaja, w.p. 1998 ogólne i regionalne rozbiez· ności w polodowcowej historii lasów bia lorusi i polski. in kalicki, t. editor, abstract of symposium paleogeografia górnego plejstocenu i holocenu wschodniej polski i bia lorusi, streszczenia referatów, posterów i przewodnik wycieczki, 5-7.10.1998 kraków, 58-59. zernitskaya, v.p. 1999 stratigraphy of the late-glacial and holocene of belorussia. problems and methods of modern regional stratigraphy. abstracts of the 4th baltic stratigraphical conference, 27-30.09.1999, riga , 112-113. zernitskaya v.p., mikhailov n.d., simakova g.i., kolkovsky v.m. and luchina g.i. 2003 radiocarbon dating and palynostratigraphy of late glacial and holocene deposits of belarus. in stratigraphy and palaeontology of geological formation of belarus. minsk, 129-134. 180 ms. ricevuto il 22 giugno 20024 testo definitivo ricevuto il 2 novembre 2004 ms. received: june 22, 2004 final text received: november 2, 2004 t. kalicki, g. calderoni & v. zernitskaya imp.chiarini& le unità stratigrafiche di riferimento nella rappresentazione cartografica dei depositi plio-quaternari continentali nel progetto carg esempi: arco alpino, pianura padana e sardegna edi chiarini*, maurizio d'orefice & roberto graciotti apat servizio geologico d'italia/dipartimento difesa del suolo, roma, italy *corresponding author: e. chiarini, apat servizio geologico d'italia/dipartimento difesa del suolo, via curtatone, 3, 00185 roma, italy. e-mail: <edi.chiarini@apat.it> abstract: e. chiarini, m. d'orefice & r. graciotti, reference stratigraphic units for mapping plio-quaternary continental deposits in the carg project: examples from alps, po plain, sardinia. plio-quaternary continental deposits have an important role in the new geological map of italy at 1:50.000 scale (carg project). the geological survey of italy suggests mapping such deposits through the unconformity-bounded stratigraphic units (ubsu), after adaptations. in this work, examples from different areas in northern italy and sardinia are analysed and compared. the results are: a) a standard rule for use of the ubsu is not applicable; b) the ubsu provide a tool for regional or interregional syntheses only in a few cases (e.g. in the large sedimentary po basin), while for minor basins (e.g. the alpine valleys) they represent a local meaning; c) consequence problems in hierarchy and correlation of units of neighbouring areas occur also. parole chiave: cartografia geologica, unità a limiti inconformi, depositi plio-quaternari continentali, italia. keywords: geological mapping, unconfomity-bounded stratigraphic units, plio-quaternary continental deposits, italy. il quaternario italian journal of quaternary sciences 21(1a), 2008 51-56 1. premessa nella nuova carta geologica d'italia alla scala 1:50.000, che il servizio geologico sta realizzando con il coinvolgimento delle regioni e delle province autonome e con il supporto scientifico delle università e del cnr (progetto carg), è stata riservata una grande importanza al rilevamento dei depositi continentali plioquaternari, almeno rispetto alle precedenti edizioni, per il crescente interesse da parte della comunità scientifica, ma soprattutto per l'importanza applicativa che rivestono. sono state pertanto definite le linee guida per la rappresentazione cartografica ed è stato affrontato il problema della classificazione stratigrafica di tali depositi (c.n.r., 1992; servizio geologico d'italia; 2001; apat, 2005a; cis, 2003). 2. le unità stratigrafiche di riferimento le unità stratigrafiche che meglio si adattano ai depositi continentali plio-quaternari sono le unità a limiti inconformi (ubsu) e le unità allostratigrafiche, delimitate inferiormente e superiormente da discontinuità stratigrafiche significative. l'uso delle unità litostratigrafiche è invece limitato ai corpi geologici caratterizzati da litologie sufficientemente omogenee. le unità istituite devono essere chiaramente identificabili sul terreno e cartografabili alla scala 1:50.000, quindi avere un certo spessore minimo e un'area di affioramento sufficientemente estesa. dopo un primo periodo in cui sono state adottate anche le unità allostratigrafiche, il servizio geologico ha raccomandato a tutti gli operatori del progetto carg la scelta delle unità a limiti inconformi (servizio geologico d'italia, 2001) per la sostanziale equivalenza dei due tipi di unità nell'utilizzazione pratica all'interno del progetto, perché, a differenza delle unità allostratigrafiche, sono previste nella international stratigraphic guide (salvador, 1994) e perché possono includere qualsiasi altro tipo di unità stratigrafica, sia in successione verticale che laterale, ivi comprese le unità litostratigrafiche. con la più recente guida italiana alla classificazione e alla terminologia stratigrafica (cis, 2003) l'uso delle unità allostratigrafiche nella carta geologica è stato definitivamente abbandonato. le ubsu nel progetto carg molto spesso hanno validità locale e non regionale, come preferibilmente previsto nella definizione. inoltre la valutazione del rango delle unità, in base al grado di discordanza angolare, all'intervallo temporale dello hiatus stratigrafico e all'estensione delle discontinuità-limite, risulta estremamente soggettiva. accanto alle ubsu e alle unità litostratigrafiche, nel progetto carg sono spesso adottate le unità informali, per introdurre differenziazioni stratigrafiche di rango inferiore all'interno di subsintemi o in assenza dei requisiti formali. infine altre unità informali, ma prive di specifiche connotazioni stratigrafiche, sono spesso presenti nella parte alta della legenda dei fogli geologici, per raggruppare i depositi più recenti. 52 e. chiarini et al. 3. esempi relativi all'arco alpino, alla pianura padana e alla sardegna dall'esame dei criteri adottati nei fogli realizzati dalle regioni dell'italia settentrionale e dalla regione sardegna, emergono differenze rilevanti nel significato attribuito alle ubsu anche quando i contesti geologici sono paragonabili. la tab. 1 riassume, nell'esempio di uno o più fogli geologici per ogni regione, il tipo, il numero, il rango, l'età e l'estensione delle unità istituite. sintetizzando una casistica molto ampia, emerge come nei fogli della sardegna sud-occidentale, della liguria, dell'emilia-romagna e in parte del veneto le ubsu siano valide nell'ambito di un bacino sedimentario, mentre in tutti gli altri casi, relativi all'arco alpino, siano state generalmente distinte successioni diverse di unità per ogni bacino idrografico o glaciale principale, o per porzioni diverse dello stesso bacino. le ubsu istituite con il primo approccio, in presenza di elementi di correlazione comprendono anche i depositi delle valli collegate al bacino sedimentario, mentre in tutte le altre situazioni si ricorre ai raggruppamenti privi di formali connotazioni stratigrafiche; il secondo approccio, più analitico, prevede un uso estensivo delle ubsu, ma comporta alcune problematiche, non sempre risolte efficacemente, al passaggio dai settori vallivi a quelli di pianura, dove le unità definite per i diversi bacini idrografici possono essere in continuità. in tutti i fogli della sardegna sud-occidentale i depositi pleistocenici sono classificati mediante una sola successione di unità a limiti inconformi (tab. 1), mentre i depositi olocenici sono distinti soltanto in base alla facies. fra i fogli della liguria finora completati solo nel foglio la spezia sono state applicate le ubsu, individuando superfici di inconformità significative a livello di bacino sedimentario. nel bacino di sarzana (bassa val di magra, tab. 1) sono stati distinti due sintemi separati da una discordanza angolare, suddivisi in subsintemi in base alla presenza di discontinuità di rango inferiore. in valle d'aosta i depositi superficiali, principalmente legati al glacialismo, sono riferiti in massima parte all'ultimo episodio glaciale del pleistocene superiore e al successivo periodo post-glaciale, fino all'attuale (carraro & gianotti, in elaborazione). in assenza di elementi di correlazione certi e non essendoci solitamente continuità fisica tra depositi di bacini diversi erano state inizialmente distinte tre successioni (dora baltea, bacini tributari maggiori e bacini tributari minori), ma nella sintesi finale è stata definita una sola successione di unità stratigrafiche (tab. 1), precisando però che il grado di affidabilità delle correlazioni diminuisce all'aumentare dell'età. in piemonte con il progetto carg è stato rilevato tutto il territorio compreso fra l'alta val di susa e la pianura ad est di torino. nei fogli torino est e torino ovest le unità non distinte in base al bacino di pertinenza comprendono sia le cosiddette unità ubiquitarie, sia i depositi recenti ed attuali dei corsi d'acqua, organizzati in unità a limiti inconformi, in evidenti rapporti di continuità fra loro e quindi non distinguibili in unità diverse, sia, infine, i depositi più antichi, precedenti all'impostazione degli attuali bacini idrografici. i depositi glaciali dell'anfiteatro di rivoli-avigliana (bacino della dora riparia) sono stati distinti in 4 sintemi principali, articolati in vari subsintemi, che rappresentano altrettante espansioni glaciali e abbracciano un intervallo temporale che va dal pleistocene medio alla fine del pleistocene superiore (fioraso et al., in elaborazione). anche nei fogli realizzati nell'ambito delle province autonome di trento e bolzano si individuano successioni specifiche di ubsu per i principali bacini glaciali o idrografici. nel foglio malè i depositi relativi a tutti i cicli sedimentari precedenti l'ultima massima espansione glaciale, di scarsissima estensione e difficilmente cartografabili alla scala 1:50.000, sono raggruppati nel supersintema di monte spinale, mentre i depositi glaciali e fluvioglaciali riferiti al last glacial maximum e alle fasi tardoglaciali sono compresi nel sintema del garda (tab. 1). il sintema post-glaciale alpino include i depositi di età compresa tra la fine dell'ultimo glaciale e l'olocene; è un'unità ubiquitaria diffusa in tutto l'ambito alpino, che ritroviamo anche nei fogli del veneto e che corrisponde al sintema del po dei fogli lombardi e della pianura veneto-friulana. nei fogli della regione lombardia le unità a limiti inconformi, istituite tutte le volte che i corpi geologici presentano superfici limite ben riconoscibili, coincidenti con il limite di un ciclo sedimentario, sono integrate dalle unità litostratigrafiche, utilizzate per corpi geologici distinguibili soltanto in base alle caratteristiche interne (bini & corbari, in elaborazione). sintemi e subsintemi sono legati ad un singolo evento sedimentario generalmente valido a livello di bacino idrografico o glaciale, mentre i supersintemi assumono un significato analogo a quello del gruppo delle unità litostratigrafiche; raggruppano sintemi in successione verticale ma anche laterale, quindi possono essere estesi a più bacini. anche nei fogli del friuli venezia giulia le ubsu sono associate alle unità litostratigrafiche. nel foglio maniago (tab. 1) i depositi più antichi sono raccolti nel supersintema del friuli, delimitato alla base e al tetto da superfici di natura erosiva marcatamente diacrone, che raccoglie vari tipi di unità, distinte in base al bacino di appartenenza, in successione sia verticale sia laterale (avigliano et al., in elaborazione). i depositi dell'lgm, raccolti in sintemi diversi per ogni bacino idrografico, sono in evidenti rapporti di eteropia nel settore meridionale del foglio e dovrebbero, quindi, costituire una sola unità. il bacino di riferimento nei fogli della regione emilia-romagna è il bacino sedimentario padano, nell'ambito del quale sono stati già completati molti fogli, definendo delle ubsu (tab. 1) di estensione regionale ed integrando i dati di superficie con quelli di sottosuolo. in genere, i sintemi, cui corrispondono nel sottosuolo spessori dell'ordine delle centinaia di metri, sono delimitati da discontinuità regionali di origine strutturale, evidenti nei profili sismici. i subsintemi sono invece connessi alla ciclicità climatico-eustatica alla scala dei 100.000 anni. le ubsu riconosciute nei settori intravallivi del margine appenninico sono state estese al sottosuolo della pianura. nei fogli delle aree di laguna e della pianura del veneto il supersintema di venezia, di età compresa fra il pliocene e la fine del pleistocene medio, comprende tutti i depositi che poggiano sulla discontinuità messiniana e che sono limitati al tetto da una discontinuità corrispondente al passaggio da sedimenti di ambiente lagunare-deltizio a sedimenti alluvionali. il successivo supersintema di mestre è limitato superiormente da una superficie di tipo erosivo o di “non depo53le unità stratigrafiche di riferimento nella rappresentazione ... regione rango e nome estensione foglio unità utilizzate delle unità e numero età delle unitàdei subsintemi unità informali olocenesardegna f. 557 cagliari ubsu s. portovesme pleistocene superiore s.s. portoscuso pleistocene superiore parte alta s.s cala mosca tirreniano unità informali olocene non distinte in base al bacino liguria ubsu s. di pian di barca pliocene?-pleistocene inferiore paleovalle pian di barcaf. 248 s. b. val di magra 4 subsintemi pleistocene bacino sedimentario sarzanala spezia s. sarzana 4 subsintemi miocene sup.?-pleistocene inf.? unità informali uid (ubiquitarie in formazione) olocene-attuale unità non distinte in base al valle d'aosta uin (ubiquitarie formate) olocene bacino di appartenenza f. 089 courmayeur ubsu s. miage 2 subsintemi olocene s. ivrea 4 subsintemi pleistocene sup.-olocene inferiore bacino dora baltea ss serra di ivrea (penultimo pleistocene mediopleistocene sup. glaciale ed episodi pre-eemiano) unità informali uid pleistocene medio-attuale uin pleistocene medio-olocene 3 unità informali pliocene medio-pleistocene mediopiemonte f. 155 ubsu s. di regia mandria 2 subsint. pleistocene medio-pleistocene sup. bacino stura di lanzo torino ovest sintema di la mandria sintema di fiano s. di magnoletto 2 subsintemi pleistocene medio-pleistocene sup. bacino dora riparia s. di frassinere 2 subsintemi s. di bennale 2 subsintemi sintema di s. gillio sintema di ponte pietra pleistocene inferiore-olocene bacino sangone sintema del sangone sintema di fornello trento e bolzano ubsu sintema post-glaciale alpino 1ss olocene non distinte in base al bacino f. 042 malè ubsu sintema del garda 2 subsintemi pleistocene superiore bacino adige supersintema di monte spinale pliocene-pleistocene superiore unità gruppi, formazioni pliocene?-pleistocene non distinte in base al bacino litostratigrafiche supersistema di palazzago pliocene sup.-pleistocene sup. di appartenenza ubsu sintema del po pleistocene sup.-olocene unità supersintema di stalletto pleistocene superiore litostratigrafiche supersintema del f. mella pleistocene superiore supersintema di sarezzo pleistocene medio supersintema di inzino pleistocene medio ubsu sintema di regne pleistocene medio supersintema di stravignino pleistocene medio bacino val trompia supersintema t. faidana pleistocene medio supersintema di dosso baione pleist. inferiore?, pleist.medio? lombardia gruppo di lavone pleistocene medio f. 099 iseo conglomerato di lodrino pleistocene medio 1:25.000 conglomerato di mamertino neogene post-messiniano conglomerato di ombriano tardo miocene pre-messiniano ubsu supersintema dei laghi pleist. superiore sintema di cantù pleist. superiore supersintema di monterotondo pleist. medio pleist sup.? sintema di m. piane pleist. medio s. di camignone pleist. medio s. di paderno di franciacorta pleist. medio bacino camuno supersintema colma del piano pleistocene sup.? supersintema di m: valenzano pliocene sup.?, base pleist. medio? unità gruppo di foppe pleistocene medio litostratigrafiche ceppo di cremignane pleistocene medio basale? ceppo di poltragno pliocene sup.?-pleist. inf.? unità informali pleistocene-oloceneemilia romagna fogli 179, 199, ubsu ss emiliano-romagnolo pleistocene medio-olocene 219, 223, 237, s emiliano-romagnolo superiore pleistocene medio-olocene bacino sedimentario padano 240-241, 256 s emiliano romagnolo inferiore pleistocene medio da 1 a 5 subsintemi subsintemi: circa 100.000 ciascuno da 1 a 5 unità informali unità informali uin pleistocene medio-olocene ubsu sintema del po olocene distinzioni in base al bacino friuli venezia unità supersintema del friuli pliocene-pleistocene superiore idr. solo per le sottounità del giulia litostratigrafiche formazioni ss del friuli f. 065 ubsu sintema spilimbergo 4 subsintemi pleistocene superiore bacino del tagliamentomaniago sintema di sequals 2 subsintemi pleistocene superiore bacino del meduna sintema di vivaro pleistocene superiore bacino del cellina veneto ubsu sintema del po 2 subsintemi olocene f. 128 supersintema di mestre pleistocene sup. bacino sedimentario padano venezia supersintema di venezia 1 subsin. pliocene-pleistocene med. tab. 1 classificazione stratigrafica dei depositi pliocenici e quaternari continentali nel progetto carg. ss) supersintema/i; s) sintema/i; ss) subsintema/i. stratigraphic classification of plio-quaternary deposits in the carg project. ss) supersinthem(s); s) sinthem(s); ss) subsinthem(s). sizione” caratterizzata dalla presenza di un paleosuolo argilloso, il caranto, che rappresenta in queste aree un ottimo livello guida e segna il passaggio alle unità oloceniche (tab. 1). 4. conclusioni gli esempi mostrano in primo luogo che nella cartografia dei depositi continentali pliocenici e quaternari le ubsu possono essere realmente utilizzate come strumento di sintesi regionale solo in presenza di bacini sedimentari sufficientemente estesi, come il bacino padano. negli altri casi, in ambito alpino, l'estrema diversificazione dell'evoluzione geologica di alcune aree, la discontinuità dei litosomi e soprattutto l'assenza di elementi utili per effettuare delle correlazioni rende necessaria l'istituzione di successioni specifiche di ubsu per ogni bacino idrografico o glaciale o di unità valide soltanto a scala locale. in questi casi le ubsu hanno finalità più analitiche, assumendo in pratica lo stesso significato delle unità allostratigrafiche. nelle aree degli anfiteatri glaciali il loro impiego può ritenersi soddisfacente mentre nelle pianure alluvionali genera problematiche di non facile risoluzione. in secondo luogo occorre sottolineare come nelle varie regioni dell'italia settentrionale non esista un criterio univoco per l'applicazione delle ubsu. ciò in parte dipende dal diverso contesto geologico, in parte da diverse scelte di fondo degli studiosi del quaternario che operano nei fogli. in molti casi non c'è accordo né sui nomi né sull'ordine gerarchico delle unità sintemiche adottate in fogli realizzati da operatori diversi, anche in presenza di livelli di riferimento, condizione molto fortunata. il problema è emerso in maniera evidente nei fogli della pianura padano-veneta, ove i confini amministrativi delle varie regioni tagliano settori dello stesso bacino sedimentario, ed è stato affrontato in una riunione congiunta del comitato d'area per la pianura padana e di quello per le alpi orientali, centrali ed occidentali, tenutasi a padova nel giugno 2004, senza però trovare una vera soluzione, come emerge dallo schema di correlazione tra le unità stratigrafiche più recenti delle regioni emilia-romagna e veneto presentato in fig. 1. bibliografia apat-servizio geologico d'italia/dipartimento difesa del suolo (2005a) indicazioni per la rappresentazione cartografica del quaternario continentale. circolare carg disponibile sul sito web www.apat.it. apat-servizio geologico d'italia/dipartimento difesa del suolo (2005b) carta geologica d'italia alla scala 1:50.000 e relative note illustrative. fogli 128 “venezia”, 179 “ponte dell'olio”, 199 “parma sud”, 219 “sassuolo”, 248 “la spezia”, 256 “rimini” e 557 “cagliari”. apat-servizio geologico d'italia/dipartimento difesa del suolo (in elaborazione) carta geologica d'italia alla scala 1:50.000. fogli 042 “malè”, 065 “maniago”, 089 “courmayeur”, 099 “iseo”, 155 “torino ovest”. disponibil i sul sito web www.apat.it. avigliano r., monegato g. & paiero g. (in elaborazione) successione continentale pliocenica-quaternaria. in dal piaz g., castellarin a., martin s., selli l., carton a., pellegrini g. b., casolari e., daminato f., montresor l., picotti v., prosser g., santuliana e. & cantelli l. note illustrative del f. 042 “malè” della carta geologica d'italia alla scala 1:50.000. apat servizio geologico d'italia/dipartimento difesa del suolo. bini a. & corbari d. (in elaborazione) stratigrafia dei depositi neogenico-quaternari. in cassinis g., corbari d., falletti p. & perotti c. (a cura di) note illustrative del f. 099 “iseo” della carta geologica d'italia alla scala 1:50.000. apat servizio geologico d'italia/dipartimento difesa del suolo. 54 fig. 1 schema di correlazione tra le unità stratigrafiche più recenti delle regioni emiliaromagna e veneto. correlation of the youngest stratigraphic units of the emilia romagna and veneto. e. chiarini et al. carraro f. & gianotti f. (in elaborazione) stratigrafia dei depositi quaternari. in perello p. & gianotti f. (a cura di) note i l lustrative del f. 089 “courmayeur” della carta geologica d'italia alla scala 1:50.000. apat servizio geologico d'italia/dipartimento difesa del suolo. cis-commissione italiana di stratigrafia (2003) guida italiana alla classificazione e alla terminologia stratigrafica. quaderni, ser. iii, 9, 155 pp., apatdipartimento difesa del suolo. c.n.r.-commissione per la cartografia geologica e geomorfologica (1992) carta geologica d'italia1:50.000. guida al rilevamento. quaderni del servizio geologico nazionale, serie iii, 1, 203 pp. fioraso g., lucchesi l. & forno m.l. (in elaborazione) stratigrafia. successione pliocenico-quaternaria. in: polino r., balestro g., cadoppi p., fioraso g., forno m. g., lucchesi s., piccardo g. b., spagnolo g.. & tallone s. note illustrative della carta geologica d'italia alla scala 1:50.000. foglio 155 torino ovest. apat servizio geologico d'italia/dipartimento difesa del suolo, roma. salvador a. (editor) (1994) international stratigraphic guide: a guide to stratigraphic classification, terminology, and procedure. 2nd edition. copublished by the international union of geological sciences and the geological society of america, boulder, colorado, 214 pp. servizio geologico d'italia (2001) indicazioni per il rilevamento del quaternario continentale. circolare carg disponibile sul sito web www.apat.it. servizio geologico d'italia (2002) carta geologica d'italia alla scala 1:50.000 e relative note illustrative. fogli 223 “ravenna”, 237 “sasso marconi”, 240-241 “forlì-cervia”. 55 ms. ricevuto il 2 aprile 2008 testo definitivo ricevuto il 17 aprile 2008 ms. received: april 2, 2008 final text received: april 17, 2008 le unità stratigrafiche di riferimento nella rappresentazione ... imp.antonioli 93 introduzione questa breve nota scaturisce dal dibattito richiesto dal consiglio di presidenza dell’aiqua al dipartimento difesa del suolo, servizio geologico d’italia, e svolto a roma nel marzo del 2007 presso la sede dell’apat. ll dibattito scientifico è scaturito con la pubblicazione del foglio geologico 557 cagliari (distribuito a partire da novembre 2006) dove i depositi fossiliferi marini di età tirreniana (125 ka) r isultavano ringiovaniti all’olocene. queste note vogliono evidenziare come la differenza tra l’attribuzione cronologica tirreniana e quella olocenica implichi una serie di ricadute e problematiche non discusse né approfondite nella legenda della carta. qui vengono riassuntivamente esposti i motivi per i quali, questi depositi fossili non possono essersi sedimentati nel corso dell’ultima trasgressione, quella olocenica. 1.1 dati sui depositi fossiliferi di is arenas l’area costiera in oggetto occupa con i “depositi di spiaggia e dei cordoni dunari antichi” fossiliferi una vasta estensione del foglio 557 (fig. 1). numerosi sono stati i lavori pubblicati su riviste nazionali ed internazionali che hanno preso in considerazione questi depositi fossiliferi marini i depositi tirreniani nell’area di montelargius (cagliari) fabrizio antonioli via a. millos 37, roma fig. 1 l’area costiera nella quale si trovano i depositi di is arenas. viene evidenziata da una freccia la massima distanza (5,2 km) dall’attuale linea di riva. 94 circostanti gli stagni di quartu e di montelargius, area denominata “is arenas”. tra tutti spicca per incisività, chiarezza e contenuti, quello firmato da ulzega e hearty (1986) e da hearty, 1986. gli autori hanno descritto i depositi e li hanno datati con tecniche incrociate (u\th e aminostratigrafie). tutte le analisi concordano nell’assegnare i depositi di is arenas all’ultimo interglaciale (mis 5.5, 125 ka). si rimanda per qualsiasi dettaglio ai lavori in oggetto, di cui viene riportata la tabella (fig. 2). sempre per l’area di is arenas gli autori riportano anche il ritrovamento di strombus bubonius. per meglio dettagliare questa ultima informazione, è stato contattato il prof. ulzega e da lui abbiamo avuto conferma sia del ritrovamento (lo strombus b. è ancora conservato presso l’archivio dell’università) che della quota (+ 4 metri) di rinvenimento, le coordinate sono 39°13’28’’59n, 09°10’36’’ 21e. tutti i lavori pubblicati successivamente (vedi anche bibliografia contenuta nelle note illustrative della carta) concordano con questa interpretazione. non è questo l’unico ritrovamento di fauna calda: alcuni strombus b., rinvenuti nell’area a quote intono al l.m. vengono citati nelle note illustrative e interpretati dagli autori della carta come “rimaneggiati”. 1.2 variazioni di livello del mare nel tirreno ed in sardegna molti sono i lavori che illustrano i meccanismi di risalita del livello dei mari italiani nel corso dell’ultimo ciclo climatico (alessio et al., 1996; antonioli e silenzi 1998; antonioli e leoni 1998; antonioli, 2000; lambeck e bard 2000; lambeck e chappel, 2001; bard et al., 2002; antonioli 2004; lambeck et al. 2004 a, b) tutti concordano che nelle aree considerate stabili il livello del mare più alto mai registrato da 100 ka sia quello odierno. depositi olocenici vengono descritti e rinvenuti fino a 4 metri sopra il livello del mare solamente in aree in attuale sollevamento (antonioli et al., 2003; antonioli et al., 2004; antonioliet all., 2006, ferranti et al., 2007) o fino a qualche metro sotto il livello del mare in aree subsidenti sulla costa del ne (lambeck et al., 2004a). il prof. paolo orrù, direttore del rilevamento dell’area marina del foglio cagliari, nelle note illustrative riporta il risultato dell’analisi di 3 sondaggi carotati a meno di 2 km dai depositi di is arenas: le radiodatazioni sui fossili lagunari campionati nei sondaggi (orrù et al., 2004), se paragonate con le stesse quote della curva di risalita calcolata per cagliari (lambeck et al., 2004a) evidenziano stabilità tettonica per gli ultimi 10 ka bp. infine una recente ricerca (antonioli et al., 2007) prende in considerazione numerosi markers archeologici oggi sommersi nel mare in molte aree della sardegna, prendendo in esame anche siti molto vicini all’area di is arenas. questi dati archeologici confermano la sostanziale stabil ità delle coste meridionali sarde e delle lagune circostanti l’area di cagliari durante gli ultimi 2700 anni. uno dei siti studiati nel lavoro si trova nella laguna di santa gilla (meno di 2 km da is arenas) ed indica molto chiaramente stabilità tettonica. fig. 2 tabella con le datazioni di ulzega e hearty, 2006. 95 1.3 considerazioni i depositi fossiliferi (spiaggia sommersa) di is arenas, raggiungono una quota di circa 4.5 metri sul livello del mare mentre la distanza dalla costa degli stessi depositi arriva a 5,2 km (fig. 1). una quota così alta ed una distanza così rilevante dall’attuale linea di riva sono facilmente spiegabili solo con un livello del mare di 6 metri più alto (lambeck et al., 2004c), come occorso nel mediterraneo circa 125 ka bp. situazioni molto simili a questa sono descritte per l’italia in ferranti et al., 2006, dove vengono illustrati 244 siti di età tirreniana. la quota di depositi tirreniani in sardegna (fig. 3) varia da 2 a 10.5 metri. nel foglio 557 cagliari, i sedimenti fossiliferi di is arenas vengono attribuiti alla trasgressione olocenica. per giustificarne la quota e la distanza dalla costa si potrebbero invocare grandiosi fenomeni di tsunami, ma la sedimentologia (spiaggia sommersa) dei depositi di is arenas esclude questa possibilità. nel corso della discussione il responsabile della stratigrafia del quaternario del foglio 557 (prof. mauro coltorti) ha giustificato la quota dei depositi fossiliferi correlandola ad un recente sollevamento dell’area costiera. anche questa eventualità sembra poco verosimile, sia per motivi topografici che per motivi geodinamici. alla luce infatti del profilo batimetrico del prolungamento a mare dell’area costiera di is arenas e dei tassi di risalita del mare negli ultimi 6 ka (lambeck et al., 2004a), anche con (improbabili) sollevamenti di 2-3 mm\anno la linea di costa non potrebbe trovarsi oggi a più di 5 km di distanza dalla costa. da un punto di vista geodinamico molti sono i motivi che escludono un sollevamento occorso durante l’olocene: fig. 3 quota della massima trasgressione tirreniana in sardegna da ferranti et al., 2006. 96 • assenza di faglie attive presenti sia nelle note illustrative che nel territorio costiero compreso tra is arenas e cala mosca dove affiorano a circa 4 metri s.l.m. i depositi fossiliferi interpretati da gignoux (1913) come tirreniani; • assenza di eventi sismotettonici storici nell’area costiera di cagliari; • assenza di terrazzi sollevati o dei presunti depositi marini del pleistocene superiore; • assenza di riscontri di sollevamento su qualsiasi dato strumentale, sia osservando il mareografo di cagliari (psmsl) che numerosi lavori che analizzano dati gps (caporali et al., 2003; serpelloni et al., 2006). • presenza del solco di battente attuale, contrariamente a quanto avviene su litologie carbonatiche in aree in sollevamento (antonioli et al., 2003) vedi fig. 4. gli autori del foglio cagliari hanno effettuato sui molluschi fossili di is arenas numerose datazioni utilizzando tecniche di radiocarbonio; tutte queste datazioni indicano inequivocabilmente che i depositi non sono olocenici. la presenza di depositi marini olocenici rinvenuti in sondaggi prossimi ad is arenas e datati con 14c (orrù et al., 2004) e archeologici sommersi, di sicura attribuzione cronologica (solinas 1997, solinas orrù 2004, antonioli et al., 2007), markers archeologici che si trovano alla quota eustatica alla quale si devono trovare (fig. 5), esclude sollevamenti nel corso dell’olocene. conclusioni come ampiamente discusso non c’è un solo dato che possa fare pensare che i depositi marini fossil i di is arenas possano essere ascritt i all’olocene. prassi consolidata è quella che i fogli geologici riportino un aggiornato riassunto di quanto scientificamente noto e pubblicato fino al momento della edizione della carta stessa. questo non è accaduto per il foglio cagliari, nella carta infatti è stata scelta una nuova interpretazione (fig. 6a) assai ardita e non suffragata da dati, contro il parere di tutta la bibliografia esistente (fig. 6b). come affermato dal prof. corselli nel corso del dibattito, si attende che gli autori della carta possano inviare a nature una nota che dimostri il sollevamento olocenico della sardegna meridionale, o, alternativamente, che i l servizio geologico riveda quello che appare come una interpretazione personale degli autori. ringraziamenti si ringrazia il dr. leone serva per la grande disponibilità dimostrata e l’organizzazione dell’incontro. fig. 4 il solco di battente attuale scolpito sui carbonati del m. sant’elia (cagliari) 97 references alessio m., allegri l., antonioli f., belluomini g., improta s., manfra l., preite m. (1996) la curva di risalita del mare tirreno negli ultimi 43 ka ricavata da datazioni su speleotemi sommersi e dati archeologici. memorie descrittive del servizio geologico nazionale, 52, 261-276. antonioli f. & leoni g. (1998) siti archeologici e loro utilizzazione quali indicatori per lo studio delle variazioni recenti del livello del mare. il quaternario, italian journal of quaternary sciences 1/98, 122-139. antonioli f. & silenzi s. (1998) rassegna dello stato dell'arte sulle ricerche delle variazioni del livello del mare relative all'ultimo semiciclo glaciale e sul concetto di stabilita' tettonica. i l quaternario, ital ian journal of quaternary sciences 1/98, 139-151. antonioli f. (2000) la risalita del mare nel corso dell’olocene. in: antonioli f., baroni c., camuffo, c. carrara, c, cremaschi, m., frisia, s., giraudi, g., improta, s., magri d., margottini, c., orombelli, g., silenzi s.: “le fluttuazioni del clima nel corso dell'olocene”, il quaternario, italian journal of quaternary sciences 13, 1, 2000, 95-128. antonioli f., kershaw s., rust d. & verrubbi v. (2003) holocene sea-level change in sicily, and its implications for tectonic models: new data from the taormina area, ne sicily. marine geology, 196, 53-71. antonioli f. (2004) sea level change in italy during last 300 ka, a revue. quaternaria nova viii, 15-28. antonioli, f., dai prà, g, segre, a.g. and sylos labini, s. (2004) new data on late holocene uplift rates in the messina strait area, italy. quaternaria nova, viii, 45-68. fig. 5 dati relativi a resti archeologici sommersi e comparati con la curva di risalita del mare (antonioli et al., 2007). la freccia indica il sito di santa gilla. 98 fi g. 6 a p ro fil o id ea le d el l’a re a co st ie ra d i i s a re na s co m e in te rp re ta to d al fo gl io g eo lo gi co 5 57 . 6b l o st es so p ro fil o co n le in te p re ta zi on i d i u lz e g a an d h e a r ty 19 86 . 6a ) 6b ) 99 antonioli f., ferranti l., lambeck k., kershaw s., verrubbi v., dai pra g. (2006) late pleistocene to holocene record of changing uplift rates in southern calabria and eastern sicily (southern italy, central mediterranean sea). tectonophysics, 422 23–40. antonioli f., anzidei m., lambeck k., auriemma r., gaddi d., furlani s., orrù p., solinas e., gaspari, a., karinja, s., kova_i_ v.,surace l. (2007) sea level change during the holocene in sardinia and in the northeastern adriatic (central mediterranean sea) from archaeological and geomorphological data. in press on quaternary science revue bard, e., antonioli, f., silenzi, s., 2002. sealevel during the penultimate interglacial period based on submerged stalagmite from argentarola cave (italy). earth and planetary science letters 196, 135–146. caporali a., martin s., massironi m. (2003) average strane rate in the italian crust inferred from a permanent gps network. geophys. j. int. 155, 255-268. ferranti l., antonioli f., amorosi a., dai prà g., mastronuzzi g., mauz b., monaco c., orrù p., pappalardo m., radtke u., renda p., romano p., sansò p., verrubbi v. (2006) elevation of the last interglacial highstand in italy: a benchmark of coastal tectonics. quaternary international 145-146, 30–54. ferranti l., monaco c., antonioli, f., maschio, l., kershaw, s., verrubbi, v., 2007 the contribution of regional uplift and coseismic slip to the vertical crustal motion in the messina strait, southern italy: evidence from raised late holocene shorelines. in press on: j. geophys. res. gignoux m., (1913) les formations marines pliocenes et quaternaires de l’italie du sud et de la sicilie. annales de l’universite de lyon 36, 693-709. hearty p.j., (1986) an inventory of last interglacial (sensu lato) age deposits from the mediterranean basin: a study of isoleucine epimerization and u-series dating. zeitschrift fur geomorphologie n. f. suppl.bd. 62, 51– 69. lambeck k., chappell j., (2001) sea level change through the lastglacial cycle. science 292, 679–686. lambeck k., bard e., (2000) sea-level change along the french mediterranean coast since the time of the last glacial maximum. earth and planetary science letters 175 (3–4), 202–222. lambeck k., antonioli f., purcell a., silenzi s., (2004a) sea level change along the italian coast for the past 10,000 yrs. quaternary science review, 23, 1567-1598. lambeck k., anzidei m., antonioli f., benini a., esposito e., (2004b) sea level in roman time in the central mediterranean and implications for modern sea level rise. earth and planetary science letters, 224, 563-575. lambeck k., antonioli f., purcell t. and stirling c. (2004c) mis 5.5 sea level in the mediterranean and inferences on the global ice volumes during late mis 6 and mis 5.5. 32° igc abstract volume. orrù p.e., antonioli f., lambeck k., verrubbi v., lecca c., pintus c. & porcu a. (2004) holocene sea level change of the cagliari. quaternaria nova viii, 193-212. serpelloni e., casula g., galvani a., anzidei m., baldi p. (2006) data analysis of permanent gps networks in italy and sourroundings regions: application of a distribuited processing approach. annals of geophysics, 49, 4/5, 1073-1104. ulzega a., and hearty j. p. (1986) -geomorphology, stratigraphy and geochronology of late quaternary marine deposits in sardinia. zeitschrift für geomorphologie n. f., suppl. bd. 62, 119-129. imp.principe_giannandrea ubsu e cartografia geologica: problemi e potenzialità di utilizzo delle unita' a limiti inconformi (ubsu) nell'interpretazione e nella rappresentazione cartografica dei depositi vulcanici quaternari l'esempio dei fogli n.ro 451 “melfi” e n.ro 452 “rionero in vulture” claudia principe1 & paolo giannandrea2 1istituto di geoscienze e georisorse, area della ricerca c.n.r. di pisa, <c.principe@igg.cnr.it> 2dipartimento di geologia e geofisica centro interdipartimentale di ricerca per la valutazione e mitigazione del rischio sismico e vulcanico, università degli studi di bari abstract: c. principe & p. giannandrea, ubsu inside geological mapping: the use of the unconformity bounded stratigraphic units in the chartography of the quaternary volcanic deposits the exemples of melfi (n. 451) and rionero (n.452) areas. by means of the use of the unconformity bounded stratigraphic units the sedimentary and volcanic stratigraphic successions outcropping in the area of mount vulture volcano (n.451 “melfi” and n.452 “rionero in vulture”) has been subdivided in synthematic units. unconformity use hallowed to define two supersynthems and five synthems. the synthematic subdivision over passed the limits of the chartographed area and make possible the correlations of deposits on a wider area. the clear and objective criteria on witch sybthematic units are based resulted in an improvement of geological significance and in the volcanological detail of the chartographed areas parole chiave: cartografia, depositi vulcanici, quaternario. keywords: geological mapping, volcanic deposits, quatenary. il quaternario italian journal of quaternary sciences 21(1a), 2008 61-68 introduzione le regole introdotte per la cartografia dei fogli della nuova carta geolgica d'italia alla scala 1:50.000 (la volpe et al. 1992), impongono per la cartografia del vulcanico le unità a limiti inconformi (ubsu) (salvador, 1987 & 1994). l'applicazione di questi principi cartografici ha, specie in un primo tempo, sollevato un vivace dibattito sulla validità delle unità sintematiche nel descrivere la storia eruttiva di un'area vulcanica, rispetto alle unità lito-stratigrafiche ed alle unità eruttive, più tradizionalmente usate. scopo di questa nota è rendere ragione della positiva esperienza degli autori nell'utilizzo delle ubsu per la cartografia dei depositi vulcanici presenti nei fogli n.ro 451 “melfi” e n.ro 452 “rionero in vulture” e per la comprensione della storia evolutiva del vulcano di monte vulture e dei suoi rapporti con i bacini lacustri e fluvio-lacustri che ad esso sono associati. all'interno di questi due fogli a scala 1: 50.000 affiora il 95% dei depositi del vulcano monte vulture e i depositi epiclastici dei bacini lacustri e fluviolacustri di melfi, atella e venosa. la varietà degli ambienti genetici e di sedimentazione presenti in questa piccola area, ed il lungo intervallo di età invece coperto dall'attività vulcanica, hanno rappresentato un ottimo banco di prova per la rigida applicazione alle vulcaniti delle unità a limiti inconformi, come definite da salvador (1987 & 1994). la presenza all'interno dei due fogli di una gran varietà di litotipi vulcanici in facies di deposizione sia primaria che secondaria e di un bilanciato quantitativo di depositi non solo vulcanici ma anche sedimentari, ha permesso, meglio forse che in altre realtà cartografiche tutte chiuse “dentro” edifici vulcanici di maggiori dimensioni del monte vulture, di verificare come le superfici di discontinuità, non solo superano i limiti litologici fra vulcanico e sedimentario, ma portano effettivamente alla definizione di unità cartografiche “obbiettive e non interpretative” come dichiarato da salvador (1987 & 1994), in grado di essere rapportate con altre realtà geologiche limitrofe e di inserirsi in altre stratigrafie mantenendo compiutamente il loro rango ed il loro significato geologico. in altre parole, parafrasando salvador (1987 & 1994): questo tipo di approccio ha rivelato possedere l'enorme vantaggio, rispetto ad altri più interpretativi, di definire delle unità stratigrafiche “naturali” (o forse sarebbe più corretto dire “geologiche”), frutto di un approccio più completo, più chiaro e più pragmatico alla stratigrafia dei depositi, che ha condotto ad una analisi più descrittiva e più lucida della storia geologica di questa area vulcanica. un'unità stratigrafica a limiti inconformi è definita come un corpo roccioso delimitato a tetto ed a letto da una ben descrivibile, significativa e dimostrabile, discontinuità nella successione stratigrafica, preferibilmente visibile a carattere regionale o interregionale (salvador, 1987 & 1994). un'unità a limiti inconformi è inoltre per sua natura sempre, in maggiore o minore misura, diacrona, (salvador, 1987 & 1994). il corretto utilizzo di questi due semplici criteri comporta che nella cartografia ubsu del vulcanico non possono essere considerate unità sintematiche i singoli corpi vulcanici (esistono per questo facies e litosomi) ed impedisce l'uso come unità cartografica fondamentale delle unità lito-stratigrafiche, relegandole al ruolo di segmenti di un 62 c. principe & p. giannandrea più vasto sintema. la stessa sorte spetta alle “unità eruttive” ed alle “unità crono-stratigrafiche”, che non possono essere assimilate ad unità a limiti inconformi; le prime perché non considerano i depositi epiclastici, le seconde per la tipologia del loro limite. il fatto che “le isocrone non possono oltrepassare le superfici di discontinuità” (salvador,1987 & 1994) impedisce anche l'uso nella cartografia del vulcanico di alcuni “deus ex machina”, talvolta usati nella passata cartografia, come i cosiddetti “ascensori”; cioè la costruzione di unità che raccolgono oggetti simili, ma presenti a diversi livelli stratigrafici. secondo questa regola, ad esempio, non ha validità di sintema un'unità costituita da numerosi coni di scorie morfologicamente indistinguibili ma aventi età diverse o addirittura di età ignota, intercalati a più livelli in una successione stratigrafica nota. i depositi vulcanici sono legati ad eventi geologici di breve durata, con eruzioni che durano pochi giorni, mesi, qualche volta anni, mentre una singola fase d'attività vulcanica può essere separata dalla successiva da lunghi periodi di quiescenza, durante i quali prevalgono le azioni erosive e la formazione di paleosuoli ed epiclastiti. queste discontinuità segnano il ritmo di vita e la storia evolutiva del vulcano. nei bacini sedimentari limitrofi alle aree vulcaniche, invece, i processi di sedimentazione sono più continui nel tempo, ed in larga parte sono alimentati dall'erosione e rideposizione dei depositi vulcanici primari. all'interno di una sequenza di questo tipo, eventuali episodi eruttivi sufficientemente estesi, di provenienza anche distale, possono costituire dei validi markers stratigrafici. nelle aree vulcaniche i limiti stratigrafici delle unità ubsu saranno quindi individuati da superfici erosive, paleosuoli e depositi epiclastici intercalati a depositi primari, mentre nei bacini sedimentari contigui tali limiti corrispondono a superfici d'erosione all'interno di una sequenza epiclastica, a discordanze legate ad effetti della tettonica ed a variazioni eustatiche del livello del mare. queste ultime, se riconosciute anche sulle vulcaniti, consentono di individuare discontinuità tracciabili a grande scala che racchiudono unità stratigrafiche complesse in cui possono coesistere, in rapporto di eteropia di facies, terreni molto differenti sia vulcanici sia sedimentari, di ambiente continentale e marino. e' evidente quindi che, per associare alle differenti fasi eruttive delle variazioni geologiche di valenza più generale, lo studio stratigrafico, sedimentologico e tettonico delle diverse aree da cartografare deve essere indirizzato ad individuare discontinuità che oltrepassino i limiti del singolo edificio vulcanico e del singolo bacino sedimentario. questo genere di discontinuità, individua le unità sintematiche. per gestire una siffatta materia occorre un approccio cartografico multidisciplinare ed integrato. di fatto la stretta collaborazione fra vulcanologi, geologi del sedimentario, stratigrafi, strutturalisti, geomorfologi e geochimici venuta ad attuarsi nel corso del rilievo carg dei fogli n. 451 e n. 452, ha largamente superato l'obbiettivo della produzione degli elaborati cartografici al 50.000, ed ha portato a compiere un notevole balzo in avanti nella comprensione della storia geologica di questa regione vulcanica e della storia evolutiva del vulcano di monte vulture (principe & giannandrea, 2002 & 2006; giannandrea, 2004; schiattarella et al., 2005; giannandrea, 2006a & b; giannandrea et al., 2004 & 2006; principe, 2006). unita' stratigrafiche a limiti inconformi i fogli n. 451 e n. 452 racchiudono la quasi totalità dei prodotti vulcanici del monte vulture, l'unico vulcano quaternario italiano ubicato sul fronte esterno della catena appenninica, ed ampie aree dei bacini sedimentari ad esso associati (fig. 1). il foglio n. 452 “rionero in vulture” include nella sua metà nord-orientale anche terreni della fossa bradanica, mentre il foglio n. 451 “melfi”, racchiude aree di catena e terreni del bacino plio-pleistocenico dell'ofanto (fig. 1). i prodotti vulcanici di monte vulture, con una età compresa tra circa 740 ka e 140 ka (fig. 2) (buettner et al., 2006) si impostano su una paleogeografia alluvionale (giannandrea et al., 2004 & 2006) e sono in rapporto di eteropia di facies con i sedimenti epiclastici e clastici, fluviolacustri dei bacini di melfi, atella e venosa ed alluvionali della fiumara dell'arcidiaconata e del fiume ofanto (fig. 1). tutti questi terreni poggiano con un rapporto di discordanza angolare sulle coltri appenniniche e sui sedimenti del margine orientale del bacino dell'ofanto (fig. 1). solo i terreni del bacino di venosa, costituendo il riempimento di una paleovalle sviluppata in gran parte nelle aree della fossa bradanica, sono discontinui sui sedimenti di colmamento dell'avanfossa (fig. 1). l'area d'affioramento delle vulcaniti è attraversata da faglie ad andamento antiappenninico di importanza litosferica che nel pleistocene medio sono state responsabili del sollevamento della fossa bradanica e dell'avampaese apulo (ciaranfi et al., 1983; pieri et al., 1994; doglioni et al., 1996), causando variazioni del reticolo idrografico del bacino di venosa (piccarreta & ricchetti, 1970; segre, 1978; boenzi et al., 1987; ciaranfi et al., 1983), ed hanno gestito il complesso processo di risalita dei magmi che hanno alimentato l'attività vulcanica (schiattarella et al., 2005; principe, 2006). la successione delle vulcaniti presenta numerose discontinuità stratigrafiche non dovute alle modalità di messa in posto dei singoli depositi primari, e rappresentate da vistose superfici erosive, paleosuoli e depositi epicalstici (che spesso rappresentano variabili della stessa discontinuità e separano successioni discordanti e/o disconformi); talora queste discontinuità fossilizzano strutture tettoniche ed a volte la loro estensione laterale non supera quella dell'affioramento in cui sono osservabili. in quest'ultimo caso, in accordo con i criteri sopra esposti, esse non sono state prese in considerazione nella definizione delle unità ubsu cartografabili. in base ai criteri d'accettabilità precedentemente accennati sono stati individuati in tutta la successione primaria del monte vulture cinque sintemi (foggianello, barile, melfi, valle dei grigi fosso del corbo e laghi di monticchio) (fig. 2), definiti da discontinuità sempre visibili e tracciabili almeno su tutta l'area di distribuzione dei relativi depositi. all'interno dei sintemi sono stati definiti più sub-sintemi (fig. 2), costituiti da singoli corpi geologici o limitate successioni di sedimentazione aventi per limite discontinuità minori ma ancora estese all'intera area d'affioramento dei relativi depositi. i sintemi sono stati raggruppati in due supersintemi (monte vulture e monticchio). il limite che separa questi due supersintemi coincide con un importante paleosuolo (marker m18; la volpe & principe, 1991) che continua ad essere tracciabile anche al di fuori dei terreni vulcanici (fig. 2). il paleosuolo m18 fossilizza una fase tettonica regionale (schiattarella et al., 2005) a seguito della quale si è verificato, probabilmente in più tempi, il ribassamento della metà meridionale del vulcano ed il collasso del suo quarto sud-occidentale (la volpe et al., 1984; la volpe & principe, 1994; ciccacci et al., 1999; giannandrea, et al., 2004 & 2006). questo limite fra i due supersintemi corrisponde anche: ad un importante iatus nell'attività vulcanica, successivo alla messa in posto del sintema di melfi, ad un cambiamento climatico verso un clima più caldo e più umido (bonadonna et al., 1998) e ad un deciso cambio di stile eruttivo, che nel successivo supersintema si esprime non attraverso l'attività di un limitato numero di apparati poligenici ubicati in un intorno della stessa zona di alimentazione, come avvenuto nel supersintema di monte vulture, ma con la creazione di una serie di piccoli centri eruttivi, ubicati in coincidenza delle principali strutture fragili, e talora fuori dell'intera area di distribuzione delle vulcaniti deposte nel corso del precedente supersintema. questi centri a differenza di quelli caratterizzanti il precedente supersintema hanno spesso carattere diatremico (stoppa & principe, 1998) e vedono il costante coinvolgimento di magmi di natura profonda e la presenza di noduli mantellici (stoppa et al., 2006). nel supersintema di monte vulture infine la tettonica prevalente è impostata su strutture ad andamento n30° 40°, con faglie connesse all'importante elemento tettonico regionale noto come “linea del vulture” (fig. 1). durante la messa in posto dei depositi facenti capo al supersintema di monticchio si hanno evidenze dell'atti63ubsu e cartografia geologica: problemi e potenzialità... vazione anche di faglie regionali ad andamento e-o e n120° (schiattarella et al., 2005). il supersintema di monte vulture comprende i sintemi di foggianello, bari le e melfi, mentre i l supersintema di monticchio comprende i sintemi di valle dei grigi fosso del corbo e dei laghi di monticchio (fig. 2). il limite che separa il sintema di foggianello da quello di barile è individuato da una superficie erosiva, da depositi epiclastici, e dalla formazione di una caldera. una superficie erosiva segna la base del sintema di melfi, mentre il limite che separa il sintema di valle dei grigi fosso del corbo da quello dei laghi di monticchio, è un paleosuolo. nella legenda delle unità cartografate (giannandrea, et al., 2004 & 2006), all'interno dello stesso sintema sono presenti sia unità vulcaniche primarie, che unità epiclastiche ed unità sedimentarie. alcuni sub-sintemi, tutti quelli per i quali la presenza di una chiara superficie di discordanza lo imponeva, sono costituiti da un unico corpo vulcanico (ad esempio il duomo di toppo san paolo); altri, come ad esempio i piccoli centri secondari presenti nella successione di vulture -san michele (fontana dei preti, serra di lupo e toppo sant'agata), fanno invece parte integrante di sub-sintemi più complessi. all'interno dei sintemi e/o dei sub-sintemi sono stati individuati dei membri (intesi come insiemi omogenei di depositi aventi caratteristiche litologiche ben definite e diverse, ma non separati da superfici di discontinuità ben tracciabili) solo nel caso delle due successioni a e b del sub-sintema di fig. 1 area d'affioramento delle vulcaniti del monte vulture e dei depositi epiclastici sedimentati nei bacini ad esso limitrofi. nel riquadro carta geologica schematica dell'italia meridionale, con l'ubicazione dell'area di affioramento delle vulcaniti del monte vulture e gli areali dei fogli della nuova carta geologica d'italia (carg), n. 451 “melfi” e n. 452 “rionero in vulture”. areal distribution of vulture volcanics and epiclastites. at left, geological sketch map of the area of interest with the indication of the carthographic unit 451 “melfi” and 452 “rionero”. 64 fig. 2 schema stratigrafico delle unità sintematiche cartografate al monte vulture e nei bacini idrografici del fiume ofanto e della fiumara di venosa. (1) età radiometrica da buettner et al, 2006. stratigraphical sketch of the synthematic chartographic units of mount vulture and hydrographical sedimentary basins of ofanto and venosa rivers. (1) radiometric age (from buettner et al, 2006). rionero (giannandrea, et al., 2004 & 2006). non sono state definite unità litologiche, ma le litologie (lave, travertini, etc..) sono state cartografate attraverso l'inserimento in carta di soprassegni. attraverso i soprassegni e l'inserimento di pedici nella legenda sono state identificate anche le varie facies deposizionali (depositi di caduta o di flusso, depositi lacustri, etc.). in questo modo si è evitata l'inutile proliferazione di colori e di c. principe & p. giannandrea caselle, ma allo stesso tempo è stata preservata l'informazione sulla tipologia dei depositi e quindi anche il legame fra il vecchio ed il nuovo modo di fare cartografia geologica, mantenendo la leggibilità dell'informazione pregressa, quale per esempio quella della vecchia carta essenzialmente litologica di hieke merlin et al. (1967). il sintema di foggianello (fig. 2) è l'unità cartografata stratigraficamente più bassa e comprende i sub-sintemi della spinoritola, di campanile e di fara d'olivo. il sub-sintema della spinoritola è costituito prevalentemente da conglomerati alluvionali e dai filoni trachitici ad haüyna affioranti in località la spinoritola (fig. 1). il sub-sintema di campanile comprende depositi esclusivamente vulcanici, sia di caduta sia derivanti da flussi piroclastici. al sub-sintema di fara d'olivo sono infine riferiti i depositi ignimbritici a composizione trachifonolitica, riconosciuti primieramente da crisci et al. (1983) ed affioranti principalmente alla periferia del vulcano, la formazione di una caldera (giannandrea, et al., 2004 & 2006) verificatasi dopo l'eruzione delle coltri ignimbritiche ed alcuni metri di depositi epiclastici di ambiente alluvionale presenti a tetto delle ignimbriti. nel sintema di barile sono compresi quattro subsintemi. la base dell'unità è il sub-sintema di toppo san paolo composto da un duomo fonolitico (hieke merlin, 1967; de fino et al, 1982 & 1986) affiorante in un'area ristretta a nord di rapolla (fig. 1), che attraversa tutta la precedente successione ed è ricoperto da piroclastiti di caduta e subordinatamente di flusso del sovrastante sub-sintema di rionero (giannandrea et al., 2004 & 2006). il successivo sub-sintema di vulture san michele comprende una spessa successione di prodotti (lave, depositi di flusso concentrato e diluito, con subordinati strati di cenere e lapilli di caduta) che nell'insieme costituiscono l'attuale rilievo morfologico di monte vulture (la volpe et al., 1988; la volpe & principe,1989 & 1991). il sub-sintema di ventaruolo, che chiude la serie di prodotti riferiti al sintema di barile, comprende depositi sia di caduta che di flusso concentrato (guest j.e., et al., 1988) e coincide con una fase distruttiva denunciata dalla formazione di larghi crateri nella zona sommitale dell'edificio vulcanico e dalla messa in posto di depositi dai vistosi caratteri freatomagmatici (giannandrea et al., 2004 & 2006). nel sintema di melfi (fig. 2) sono raggruppate le lave haüynititiche (hieke merlin, 1967) dei sub-sintemi del castello di melfi e di piano di croce, i depositi epiclastici, in facies alluvionale e palustre, del sub-sintema di piano del gaudo e spessi depositi di travertino affioranti lungo la fiumara dell'arcidaconata, distinti come sub-sintema di losagne arcidiaconata (giannandrea et al., 2004 & 2006). il supersintema di monticchio (fig. 2) raggruppa i prodotti vulcanici emessi da numerosi piccoli centri (identificati come sub-sintemi) distribuiti sia su faglie orientate in direzione n30°-40° e raggruppati nel sintema della valle dei grigi fosso del corbo (subsintemi di masseria di cuscito, imbandina e case lopes), che su faglie in direzione n120° e e-o raggruppati nel sintema di monticchio (sub-sintemi di casa rossa, piano comune, lago grande, lago piccolo e serra di bràida) (giannandrea et al., 2004 & 2006). uscendo dall'areale occupato dall'edificio vulcanico e dall'areale di distribuzione in facies primaria dei suoi depositi, si entra nelle valli della fiumara di venosa (giannandrea, 2006a e b) e del fiume ofanto (giannandrea, 2004) dove in aree distali al vulture è stato possibile riconoscere dei depositi primari riconducibili ad alcune delle sue eruzioni più voluminose (depositi di flusso piroclastico e di caduta correlabili con le coltri ignimbritiche di fara d'olivo e depositi di flusso e, più spesso, di caduta facenti parte del sintema di barile) intercalati a sedimenti alluvionali e a luoghi lacustri, terrazzati. tali terrazzi, sono stati correlati mediante profili morfologici longitudinali rettificati, tracciati lungo i fondovalli dei due fiumi. la correlazione delle unità terrazzate a quelle del monte vulture ha interessato solo i livelli gerarchici di sintema e di supersintema (fig. 2) e non i sub-sintemi. difatti nell'operare la correlazione su vaste aree è stata riscontrata una parziale sovrapposizione fra i sub-sintemi ed i litosomi, questi ultimi intesi come edifici o periodi d'attività vulcanica. conclusioni la descrizione oggettiva dei limiti e delle loro caratteristiche è alla base della definizione delle unità stratigrafiche a limiti inconformi. in questo la cartografia del vulcanico non ha motivo per discostarsi dalla cartografia d'altri ambienti di sedimentazione. l'utilizzo delle ubsu non preclude o limita in alcun modo l'informazione sui singoli eventi eruttivi né sulla litologia dei depositi vulcanici. la cartografia sintematica del vulcanico, del monte vulture in questo caso specifico, beneficia invece rispetto ad altri tipi di cartografia d'elementi geologici obbiettivi, evidenza di processi che molto difficilmente possono non avere avuto un ruolo importante nella ricostruzione della storia evolutiva di un vulcano. questi elementi si aggiungono al mero quadro stratigrafico, favorendo l'identificazione d'importanti eventi geologici (stasi, erosioni, cambiamenti climatici, etc.) e diventano evidenze cartografiche dell'evoluzione paleogeografia, delle periodicizzazioni dell'attività vulcanica, degli eventi tettonici e vulcanotettonici. la gerarchizzazione dei limiti consente inoltre di distinguere episodi d'attività di interesse solo stratigrafico da eventi legati a fatti geologici regionali e di maggiore importanza nella ricostruzione dell'evoluzione del vulcanismo. lo studio al monte vulture dei bacini epiclastici associati alle vulcaniti primarie, infine, ha messo in luce come una verifica della corretta attribuzione gerarchica dei limiti tracciati su vulcani che si situano in aree continentali, può essere fatta usando i limitrofi bacini sedimentari. difatti, la giustezza della suddivisione della serie vulcanica primaria in due supersintemi (monte vulture e monticchio), operata sul vulcano, è stata confermata dal ritrovamento nei bacini sedimentari limitrofi al vulture, di una fase di sollevamento regionale successiva alla fase di sedimentazione della porzione superiore di queste epiclastiti, a partire dallo stesso livello stratigrafico riconosciuto come l imite di supersintema sul vulcanico. il limite tracciato sul vulcanico in facies primaria ha mantenuto quindi la sua validità anche al di fuori dell'ambiente di sedimentazione in cui è stato definito, ed è stato possibile estenderlo su scala regionale, come espressamente richiesto dalla normativa ubsu per un limite di supersintema. 65ubsu e cartografia geologica: problemi e potenzialità... riferimenti bibliografici boenzi f., la volpe l. & rapisardi l. (1987) evoluzione geomorfologica del complesso vulcanico del monte vulture (basilicata). boll soc geol it, 106, 673-682. bonadonna f.p., brocchini d., laurenzi m.a., principe c. & ferrara g. (1998) stratigraphical and chronological correlations between monte vulture volcanics and sedimentary deposits of the venosa basin. quaternary international, 47, 87-96. buettner a., principe c., villa i.m. & brocchini d., (2006) geocronologia 39ar-40ar del monte vulture. in: c. principe (a cura di) “la geologia del monte vulture”. grafiche finiguerra lavello, 7386. ciaranfi n., ghisetti f., guida m., iaccarino g., lambiase s., pieri p., rapisardi l., ricchetti g., torre m., tortorici m. & vezzani l. (1983) carta neotettonica dell'italia meridionale. prog. fin. geod. del c.n.r., pubbl. n° 515, 62. ciccacci s., del gaudio v, la volpe l. & sansò p. (1999) geomorphological features of monte vulture pleistocene volcano (basilicata, southern italy). z. geomorph. n.f., 114, 29-48. cortini m. (1975) età k-ar del monte vulture (lucania). riv. it. geof. sc. affini, 2, 45-46. crisci g., de fino m., la volpe l. & rapisardi l. (1983) pleistocene ignimbrites of monte vulture (basilicata, southern italy). n. jb. geol. paläont. mh, 12, 731-746. de fino m., la volpe l. & piccarreta g. (1982) magma evolution at mount vulture (southern italy). bull. volcanol., 45, 115-126. de fino m., la volpe l., peccerillo a., piccarreta g. & poli g. (1986) petrogenesis of monte vulture volcano (italy): inferences from mineral chemistry, major and trace element data. contrib. mineral. petrol., 17, 153-145. doglioni c., tropeano m. mongelli f. & pieri p. (1996) middle-late pleistocene uplift of puglia: an “anomaly” in the apenninic foreland. mem. soc. geol. it. 51, 101-117. giannandrea p., la volpe l., principe c. & schiattarella m. (2004) carta geologica del monte vulture alla scala 1:25.000. lac, firenze, in boll. soc. geol. it, 125. giannandrea p., la volpe l., principe c. & schiattarella m. (2006) unità stratigrafiche a limiti inconformi e storia evolutiva del vulcano medio-pleistocenico di monte vulture (appennino meridionale, italia). boll. soc. geol. it.,125, 67-92. giannandrea p. (2004) i depositi terrazzati affioranti nell'alta valle del fiume ofanto (foglio n. 451 “melfi”, appennino campano-lucano . i l quaternario, 17, (2/2), 511-521. giannandrea p. (2006a) il bacino fluvio-lacustre di venosa. in: c. principe (a cura di) “la geologia del monte vulture”. grafiche finiguerra lavello, 5572. giannandrea p. (2006b) carta geologica del bacino di venosa. in: c. principe (a cura di) “la geologia del monte vulture”. grafiche finiguerra lavello. guest j.e., duncan a.m. & chester d.k. (1988) monte vulture volcano (basilicata, italy): an analysis of morphology and volcaniclastic facies. bull. volcanol. 50, 244-257. hieke merlin o. (1967) i prodotti vulcanici del monte vulture (lucania). mem. ist. geol. mineral. univ. padova, 26, 3-66. hieke merlin o., la volpe l., piccarreta g. (1967) carta geologico-petrografica del gruppo vulcanico del monte vulture (lucania). scala 1: 25.000. mem. ist. geol. mineral. univ. padova, 26, 3-66. la volpe l. & principe c. (1989) stratigrafia e storia eruttiva del monte vulture revisione ed aggiornamenti. gruppo nazionale per la vulcanologia. bollettino 1989, 889-902 la volpe l. & principe c. (1991) comments on "monte vulture volcano (basilicata italy): an analysis of morphology and volcaniclastic facies" by je guest, am duncan and dk chester. bull volcanol, 53, 222-227. la volpe l. & principe c. (1994) il monte vulture. guida all'escursione generale precongressuale, 77° congr. naz. soc. geol. it., bari. la volpe l., patella d., rapisardi l. & tramacere a. (1984) the evolution of the monte vulture volcano (southern italy): inferences from volcanological, geological and deep dipole electrical soundings data. journ. volcanol. geotherm. res., 22, 147162. la volpe l., principe c. & rapisardi l. (1988) monte vulture eruptive history: new stratigraphic and volcanological data. atti del 74° congresso nazionale della societa` geologica italiana, sorrento 13-17 settembre 1988, vol. a, 346-354. la volpe l., pasquarè g., principe c., vezzoli l. (1992) stratigrafia e cartografia del vulcanico. in “guida al rilevamento della carta geologica d'italia alla scala 1:50.000 edito a cura della commissione per la cartografia geologica e geomorfologica del cnr. quaderni del servizio geologico nazionale, serie iii, n.ro1, roma, p. 203. piccarreta g. & ricchetti g. (1970) i depositi del bacino fluvio-lacustre della f iumara di venosamattinelle e del torrente basentello. mem. soc. geol. it., 9, 121-134. pieri p., sabato l. & tropeano m., (1994) evoluzione tettonico-sedimentaria della fossa bradanica a sud del'ofanto nel pleistocene. in guida alle escursioni del 77°congresso nazionale della s.g.i., quad.bib. prov.matera, 15, 35-54. principe c., giannandrea p. (2002) stratigrafia ed evoluzione geologica del vulcano vulture (basilicata, italia) rapporti fra vulcanismo ed ambienti sedimentari. società geologica italiana, torino settembre 2002 principe c. & giannandrea p. (2006) storia evolutiva del monte vulture. in: c. principe (a cura di) “la geologia del monte vulture”. grafiche finiguerra lavello, 49-53. principe c. (a cura di) (2006) la geologia del monte vulture. grafiche finiguerra lavello, 217 pp. salvador a. (1987) unconformity bounded stratigraphic units. geological society of america bulletin 98, 232-237. salvador a. (ed) (1994) international stratigraphic guide. international union of geological sciences, 66 c. principe & p. giannandrea trondheim, norway, and geological society of america, boulder, 214 pp. schiattarella m., beneduce p., di leo p., giano s.i., giannandrea p., principe c. (2005) assetto strutturale ed evoluzione morfotettonica quaternaria del vulcano del monte vulture (appennino lucano). boll. soc. geol. it., 124, 543-562. segre a. g., (1978) il pleistocene ed il paleolitico della basilicata. atti xx riun. scient. ist. it. preist. protost.,15-39. stoppa f. & principe c. (1998) eruption style and petrology of a new carbonatitic suite from the mt. vulture (southern italy): the monticchio lakes formation. journ. volcanol. geotherm. res., 80, 137-153. stoppa f., rosatelli g., principe c (2006) classificazione modale delle vulcaniti del monte vulture. in: c. principe (a cura di) “la geologia del monte vulture”. grafiche finiguerra lavello, 87104. villa i. m. (1986) cronologia 39ar / 40ar del complesso vulcanico del monte vulture. rend. simp, 41, 146-147. ms. ricevuto il 2 aprile 2008 testo definitivo ricevuto il 17 aprile 2008 ms. received: april 2, 2008 final text received: april 17, 2008 67ubsu e cartografia geologica: problemi e potenzialità... imp.paiero-monegato tthhee pplleeiissttoocceennee eevvoolluuttiioonn ooff aarrzziinnoo aalllluuvviiaall ffaann aanndd wweesstteerrnn ppaarrtt ooff ttaagglliiaammeennttoo mmoorraaiinniicc aammpphhiitthheeaattrree ((ffrriiuullii,, nnee iittaallyy)) ggiioovvaannnnii ppaaiieerroo11 && ggiioovvaannnnii mmoonneeggaattoo11 1dipartimento di georisorse e territorio, università di udine, via cotonificio 114, i-33100 udine. abstract the pleistocene evolution of arzino alluvial fan and western part of tagliamento morainic amphitheatre (friuli, ne italy) the geologic survey of the sheet 065 “maniago” (carg project) allowed to gain founded data for attempting a reconstruction of pleistocene evolution of this portion of friuli piedmont plain, located in left hydrographic slope of tagliamento river. units recognised by bounding discontinuity are unconformity-bounded stratigraphic units in the meaning used in carg project. eight units have been distinguished: four related to arzino alluvial fan, three to tagliamento morainic amphitheatre and one to ragogna hill southern slope evolution. these units outcrop along tagliamento left slope and inside ponte brook valley. arzino alluvial fan is made by stratified gravel and sandy deposits, tagliamento basin units are made by glacial (lodgement till and melt-out till) and fluvioglacial sediments (mainly sandy gravel), while the units of ragogna hill southern slope are colluvial (muddy diamicton) and alluvial (sandy gravel and sand). relationships between arzino alluvial fan and tagliamento endmorain system, happened during quaternary age, let to understand the relative chronology of events, erosive and sedimentary, that has interested pinzano narrow area during this time span. during early and middle pleistocene through it arzino stream flew down and built an alluvial fan; then from middle pleistocene glacial advances in tagliamento basin began to interfere with alluvial fan till it was completely covered during last glacial maximum in tagliamento basin, for which a find provided the age 19.075±160 14c yr bp. as regards older units, probably many events are juxtaposed without recognisable and classifiable bounding surfaces, whereas chronological reconstruction becomes more reliable for late pleistocene units. riassunto l’evoluzione pleistocenica del conoide alluvionale dell’arzino e della parte occidentale dell’anfiteatro morenico del tagliamento (friuli, italia ne) la presente nota riguarda la porzione di pianura pedemontana friulana posta in sinistra idrografica del fiume tagliamento presso ragogna, dove affiora una successione di unità di età quaternaria, caratterizzabili in base alle discontinuità che le delimitano ed alla composizione litologica dei clasti. grazie ai nuovi dati acquisiti durante il rilevamento geologico del foglio 065 “maniago” (progetto carg) i depositi di età quaternaria sono stati distinti utilizzando come unità di riferimento le unconformity-bounded stratigraphic units con il significato utilizzato per la cartografia del progetto carg. vengono qui descritte otto unità: quattro relative al conoide alluvionale del torrente arzino, tre dell’anfiteatro morenico del tagliamento ed una legata all’evoluzione del versante meridionale del monte di ragogna. tali unità affiorano con buona continuità nella scarpata sinistra del fiume tagliamento tra san pietro e aonedis e all’interno della valle del rio ponte. i depositi relativi al conoide del torrente arzino sono caratterizzati da ghiaie e sabbie variamente stratificate e classate; quelli relativi al bacino del tagliamento sono di origine glaciale (till di alloggiamento e di ablazione s.l.) e fluvioglaciale (in prevalenza ghiaie sabbiose); mentre quelli del versante meridionale del monte di ragogna sono di origine colluviale (diamicton limosoargilloso) ed alluvionale (ghiaie sabbiose e sabbie). le relazioni tra il conoide alluvionale dell’arzino e i depositi legati alle avanzate glaciali nel bacino del tagliamento hanno favorito la comprensione della cronologia relativa degli eventi, erosivi e sedimentari, che hanno interessato l’area presso la stretta di pinzano durante il quaternario. durante il pleistocene inferiore ed in parte del medio per essa transitavano le acque del torrente arzino, che ha costruito un conoide alluvionale che aveva qui il proprio apice. a partire dal pleistocene medio i depositi legati alle avanzate del ghiacciaio del tagliamento hanno cominciato ad interferire con l’aggradazione del conoide il quale è stato sepolto interamente durante l’ultimo episodio glaciale, per il quale un reperto ha fornito la data 19.075±160 14c a bp. nel caso delle unità più antiche probabilmente si sovrappongono più episodi sedimentari senza superfici limite riconoscibili e classificabili; mentre per le unità del pleistocene superiore la ricostruzione cronologica si fa più affidabile. keywords: alluvial fan, tagliamento morainic amphitheatre, pleistocene, arzino, friuli. parole chiave: conoide alluvionale, anfiteatro morenico del tagliamento, pleistocene, arzino, friuli. il quaternario italian journal of quaternary sciences 1166(1), 2003, 185-193 11.. iinnttrroodduuccttiioonn the study area (fig. 1) includes a part of piedmont plain between tagliamento river, ragogna hill and western ridges of the morainic amphitheatre. tagliamento river flows in the last stretch of the valley northern-side of ragogna hill, where arzino stream flows into tagliamento, that, after crossing pinzano narrow, flows out in the plain where it shaped the late pleistocene plain into a slope 60÷70 m high. here a complex of quaternary units outcrops; this is the main object of this paper. continuity of tagliamento's left slope is cut off by three tributary brooks, namely mordaro, ponte and fos (fig. 1). in particular in ponte brook's slopes, about 2 km long, and in fos brook's ones, about 1.1 km long, many outcrops allow to observe in the third dimension units outcropping in tagliamento's left slope and to correlate them to tagliamento amphitheatre ones. this complex morainic amphitheatre witnessed that, during pleistocene times, tagliamento valley was the site of a glacier that many times flew out southward in the friuli piedmont plain. the portion of the glacier interesting this area corresponded to "san daniele" lobe, that flew inside the sag between ragogna hill and susans hill. morainic ridges, in the southern side of ragogna hill, are set against the versant, then they are continuos eastward as far as san daniele village, where are interrupted by the valley of corno stream, originate by one of the main and lasting meltwater streams of last glacier 186 g. paiero & g. monegato fig. 1 geologic sketch map of the study area and its location (modified after m.u.r.s.t., 1997). carta geologica schematica dell’area studiata e sua ubicazione (modificato da m.u.r.s.t., 1997). (feruglio, 1920; comel, 1955; croce & vaia, 1985). pre-quaternary substratum outcropping in this area is given by montello conglomerate (massari et alii, 1986), an upper tortonian lower messinian terrigenous sequence and by the osoppo conglomerate (dalla vecchia & rustioni, 1996; zanferrari et alii, in prep.), an upper messinian – pliocene continental conglomeratic sequence . study area lies on the sse-verging arba-ragogna thrust (fig. 1), the more external thrust of the eastern southalpine chain front (zanferrari et alii, 2002; zanferrari et alii, in prep.). such structure is characterised by tectonic activity from upper miocene to present (zanferrari et alii, in prep.). this paper is aimed at illustrating the quaternary succession of a part of friuli piedmont plain (ne italy). in particular the complex sequence of existing sedimentary units, so far undervalued by detail stratigraphic studies, was sorted out, in order to reconstruct, downflow of pinzano narrow, the evolution of arzino alluvial fan and its relationships with glacial and fluvioglacial units of tagliamento. this study uses new data gained during cargfvg project's geological survey for the new 065 "maniago" geologic sheet at the scale 1:50.000. 22.. pprreevviioouuss ssttuuddiieess early authors surveyed quaternary deposits of this area since late ‘800 (taramelli, 1875; tellini, 1892; penck & brückner, 1909). first official geological map was "udine" sheet of carta geologica delle tre venezie at the scale 1:100.000 (feruglio, 1925; 1929b). in this map the glacial deposits, located in the study area, have a würm age; older deposits given to riss glacial age are marked in the borgo di mezzo terrace slopes (tellini, 1892; feruglio, 1929a) and recognised by the presence of a strongly weathered level of gravel, called ferretto, between these glacial units. later authors accepted feruglio’s assumptions for amphitheatre glacial units, except of sacco (1937). the latter gave a mindel? age to feruglio's riss one, for the strong reworking of outer morainic ridges; a riss age to higher morainic ridge, that feruglio gave to würm acme, since riss glaciation were considered the longest; and a würm age to inner ridges because less developed. whole tagliamento morainic amphitheatre was studied also by gortani (1959), carraro & petrucci (1977; 1982) 187the pleistocene evolution of arzino ... and croce & vaia (1985). whereas the presence of a pleistocene glacier inside arzino valley was witnessed by glacial deposits only in the head of valley; this glacier was probably a lobe of tagliamento glacier, overflowing through chiampón and chianzután saddles (tellini, 1892; penck & brückner, 1909; zenari, 1927; sacco, 1937; comel, 1956; gortani, 1959). the deposits of tagliamento left slope were generally studied joined with amphitheatre ones. the deposits of amphitheatre are directly related to glacial advances evidenced by morainic ridges; only di bernardo et alii (1998) gave a short stratigraphy of the fluvial succession, ascribing all them to tagliamento basin. 33.. mmeetthhooddss aimed at planning and addressing properly the field work, the study area has been previously studied by interpreting aerial images and analysing the microrelief on topographic maps (scale 1:10.000 and 1:5.000) with 1 m contour lines. each outcrop has been mapped and the observed features were recorded for the geologic data base of carg project (zanferrari et alii, 2000), according to a modified version of the guidelines after baggio et alii (1997). sedimentary facies and discontinuities were examined in detail to distinguish the elements of the sedimentary architecture. the facies classifications, after miall (1996) for fluvial deposits and eyles et alii (1983) for glacial deposits, have been used; for classification of the latter bini & orombelli (1988) review has been adopted. the bounding surfaces classification after miall (1996) (tab. 1), with boyce & eyles (2000) review for glacial deposits, has been used. hierarchization of bounding surfaces was above all obtained using the evolution degree of the soils developed during their shaping. units obtained are unconformity-bounded stratigraphic units (issc, 1994), in the meaning of carg project (zanferrari et alii, in prep.), and they were split up by relationship between bounding surfaces, litofacies, petrographic nature of clasts and sedimentary body alteration and deformation. blair & mcpherson (1999) grain-size scale was adopted, while the given color for sediments, weathered horizons and soils refers to the munsell soil color charts. radiocarbon data were obtained at radiocarbon lab of “dipartimento di scienze della terra” of "la sapienza" university of rome. tab. 1 classification of bounding surfaces by miall (1966) / classificazione delle superfici limite secondo miall (1966). rraannkk ddeeffiinniittiioonn ttiimmee ssccaallee ooff pprroocceessss ((aa)) 1st order set bounding surface; microform, minor erosion 10-5 10-4 10-3 2nd order coset bounding surface; mesoform 10-2 – 10-1 3rd order dipping 5-20° in direction of accretion; macroform growth increment 100 101 4th order minor channel scour, flat surface bounding floodplain elements; immature paleosol 102103 5th order flat to concave-up channel base; mature paleosol 103 104 6th order flat, regionally extensive or base of incised valley 104 105 7th order sequence boundary; flat, regionally extensive, or base of incised valley 105 106 8th order regional disconformity, basin fill complex 106 107 188 a critical element for fixing units was clasts' petrographic analysis, that let to distinguish deposits on their source basin, because the two watercourses whose sediments characterised the area have a lithologic different source basin: light and monochromatic carbonate deposits, with dolomites and limestones more than 95%, as concerning arzino stream; polychromatic carbonates, with remarkable siliceous and volcanic clasts portion and presence of clasts of metamorphics, as concerning tagliamento river. in the investigated area two different main sites can be distinguished: rio ponte section (a-a’ in fig. 1), a glacial sequence heteropic with ragogna hill hillslope sediments, whose most complete sections crop out inside ponte brook valley, where it has an overall thickness of 90 m, even if some isolated boulders were found 50 m higher than morainic ridges. san pietro aonedis section (b-b’ in fig. 1), where an alluvial sequence of 60-70 m thick is exposed in left fluvial slope of tagliamento river from pinzano bridge to aonedis. some stratigraphic units are present in both sections because their deposits are phisically continuous from one to another. 44.. rriioo ppoonnttee sseeccttiioonn the rio ponte section is 500 m long and 150 m high. it is located in the head of ponte brook valley. here many units crop out (zanferrari et alii, in prep.) (fig. 2): the complex rio ponte unit, having source from geomorphologic evolution of southern side of ragogna hill, three different glacial units: plaino, santa margherita and canodusso synthems, related to tagliamento glacier expansions. 44..11.. rriioo ppoonnttee uunniitt ((uurrpp)): this unit outcrops only inside ponte brook incision and it is made by different sedimentary bodies with an average dip of strata of 25-30 degrees southward; unit has been divided in the following facies: massive to stratified gravel (gci-gh), locally cemented; clasts are subangular and carbonate, resulted from montello conglomerate and osoppo conglomerate erosion; texture is clast-supported to matrix-supported; matrix is muddy and weathered, having a strong brown (7.5yr4/6) color. interstratified sandstones are present, laminated to massive, about 50 cm thick. these are deposits related to small fans originated from ragogna hill southern side incisions and active before the deposition of glacial units. muddy massive diamicton, matrix-supported (dmm), made of rounded, strongly alterated clasts; carbonate lithologies are absent; muddy matrix is weathered and has a yellowish red (5y5/6) color. this facies has a variable thickness, from less than 50 cm to some meters, it is interbedded with gravel facies. its origin is probably colluvial from weathering process interesting osoppo conglomerate and early pleistocene tagliamento basin deposits. basal boundary is a disconformity and locally an angular unconformity of 15 degrees with the substratum. boundary existing on the top is a weathered surface on gravel facies, characterised by a paleosol 3.5 m thick, with an 1 m thick argillic horizon with a yellowish red (5yr4/6) color. 44..22.. ppllaaiinnoo ssyynntthheemm ((ppllii)):: this unit is here made by a “loose skeletal till”, characterised by isolated, weathered boulders and cobbles scattered in ragogna hill southern side, between 340 and 310 m a.s.l. this is the evidence of the older glacial expansion so far observed in tagliamento morainic amphitheatre. 44..33.. ssaannttaa mmaarrgghheerriittaa ssyynntthheemm ((ssnnmm)):: this unit, whose morphology was strongly reshaped by late pleistocene sedimentary events, is situated just next to some soft ridges outwardly to the main ridges of the amphitheatre. unit is made by a sequence of glacial deposits; in the study section they can be distinguished in: silty massive diamicton, matrix-supported and heavily consolidated (dmm), rich in chaotic clasts, from subangular to subrounded, striated and glacially shaped (flatiron and bullet shaped). matrix is silt with sand, dark yellowish brown (10yr4/5) to brownish yellow (10yr6/6). the facies presents pods and irregular shaped rafts of sorted sediment, l ikely originated by compression of fine lenses in subglacial environment, and linear or cluster concentration of clasts, pebble to f ine boulder-sized. the whole deposit can be defined as a subglacial lodgment till. fig. 2 schematic cross section of rio ponte section (a-ai in fig. 1). mon: montello conglomerate; osp: osoppo conglomerate; urp: rio ponte unit; pli: plaino synthem; snm: santa margherita synthem; nds: canodusso synthem; a: alluvial deposits; b: lodgment till; c: ablation till; d: “loose skeletal till”; ar: arba–ragogna thrust. sezione schematica della sezione del rio ponte (a-ai in fig. 1). mon: conglomerato del montello; osp: conglomerato di osoppo; urp: unità del rio ponte; pli: sintema di plaino; snm: sintema di santa margherita; nds: sintema di canodusso; a: depositi alluvionali; b: till d’alloggiamento; c: till di ablazione s.l.; d: “morenico scheletrico sparso”; ar: faglia arba-ragogna. g. paiero & g. monegato m a.s.l. 189 massive diamicton, matrix-supported to clast-supported (dmm-dcm), rich in subangular boulders; this deposit is normally consolidated and locally cemented; it is rich of striated clasts in a silty-sandy matrix. it can be classified as an ablation till. lodgment till is about 10 m thick; it is easily observing in ponte brook incision and in the head of fos brook valley, where is heteropic with fluvioglacial gravel (see the further on “santa margherita synthem” in “san pietro aonedis section”). whereas ablation till has maintained a thickness of 15 m, moreover it must taken to account several isolate boulders and pebbles situated at 250÷275 levels on ragogna hill and that can be relate to this unit. lower boundary is an erosion surface on rio ponte unit deposits. upper boundary with canodusso synthem is an erosion surface sometimes marked by a weathered surface having brown to strong brown (7.5yr4/4-5/6) color. 44..44.. ccaannoodduussssoo ssyynntthheemm ((nnddss)):: this unit represents last main sedimentary event in friuli piedmont plain, and is characterised by a glacial-fluvioglacial sequence morphologically evident in the whole morainic amphitheatre. in the study area these glacial deposits make up a double end morainic ridge, the outer more discontinuous and lower (quotes from 250 to 270 m), the inner more defined and higher (quotes from 260 to 300 m). fluvioglacial deposits are made by clast-supported massive gravel (gcm) to crudely bedded gravel (gh), weakly cemented, with subrounded clasts, medium pebble to boulder sized, with silty-sandy matrix. thickness is variable and not exceeding 5 m. the reworked top of these deposits makes the terraced surface on right side of ponte brook. glacial deposits can be distinguished in: silty massive diamicton, matrix-supported and heavily consolidated (dmm), rich of chaotic clasts, from subangular to subrounded, striated and glacially shaped (flat-iron and bullet shaped). matrix is made by silt with sand, dark greyish brown (2.5y5/2) to light olive brown (2.5y5/4). this facies is rich of pods and irregular shaped rafts of sorted sediment, likely originated by compression of fine lenses in subglacial environment, interbeds of thin bedded to massive silty sand and linear or cluster concentration of clasts, pebble to fine boulder-sized, are present. these elements are often glaciotectonically deformed. basal level of this deposit, because of its general deformation, can be classified as a deformation till; it can be defined as a subglacial lodgment till. massive diamicton, matrix-supported to clast-supported (dcm-dmm), normally consolidated; clasts are generally subangular, many of which are striated, granule to boulder sized; they are characteristic of tagliamento basin with very rare exotic pebble of austro-alpine gneiss; rich of striated clasts in a siltysandy matrix pale yellow (2.5y7/3) colored. it is a supraglacial ablation till. lodgment till has a kept thickness of 20 m, while ablation till has a kept thickness of 40 m. the basal boundary consists of an erosion surface over rio ponte unit and santa margherita synthem deposits; near canodusso hamlet, a sample of wood fragment was found in silty-clayey sediments next to basal surface (fig.3); this sample yielded the conventional 14c age of 1199..007755±±116600 yr bp (rome-1393). the upper boundary is the topographic surface marked by a weathered surface having dark yellowish brown (10yr4/4) to brown (7.5yr4/4) color. 55.. ssaann ppiieettrroo - aaoonneeddiiss sseeccttiioonn in san pietro aonedis section (left tagliamento fluvial slope) is displayed a series of pleistocene sedimentary bodies, laid down by watercourses flowing out from pinzano narrow, and fluvioglacial deposits connected with glacial end moraines of tagliamento amphitheatre; in this site, 4300 m long and 60-70 m high, 7 units are distinguishable (fig. 4). 55..11.. bboorrggoo ddii mmeezzzzoo ssyynntthheemm ((bbggmm)):: outcropping from pinzano narrow to ponte brook valley, it is made by a sequence of clast-supported massive gravel (gcm) to crudely-bedded gravel (gh), generally lithified, with carbonate (more than 95% of white or grey carbonate) alterated subrounded clasts, medium pebble to boulder sized. its matrix is muddy sand, altered and fig. 3 canodusso synthem lower boundary with the location of sample dated (rome-1393). snm: santa margherita synthem; nds: canodusso synthem. limite inferiore del sintema di canodusso con l’ubicazione del campione datato (rome-1393). snm: sintema di santa margherita; nds: sintema di canodusso. the pleistocene evolution of arzino ... 190 f ig . 4 a) s ch em at ic c ro ss s ec tio n of s an p ie tr o – a on ed is s ec tio n (b -b i i n f ig . 1 , v er tic al e xa gg er at io n x5 ), n ot e di ffe re nt t hr ow s ca us ed b y a rb a– r ag og na gr ow in g th ru st ( a r ). m o n : m on te llo c on gl om er at e; o s p : o so pp o c on gl om er at e; b g m : b or go d i m ez zo s yn th em ; v m i: v ia d i m ol in s yn th em ; a o n : a on ed is s yn th e m ; p l i: p la in o s yn th e m ; v l z : v il lu zz a s yn th em ; s n m : s an ta m ar gh er ita s yn th em ; n d s : c an od us so s yn th em . 116 : ev ol ut io n ep is od es o f ex am in ed p la in ( fo r de sc rip tio n se e cp t. 6) . b) d et ai l pi ct ur e of v ia d i m ol in s lo pe . a) s ez io ne s ch em at ic a de lla s ez io ne d i s an p ie tr o – a on ed is ( b -b i in f ig . 1, e sa ge ra zi on e ve rt ic al e x5 ), da n ot ar e i di ff er en ti ri ge tt i ve rt ic al i ca us at i da lla fa g li a i n c re sc it a a rb a -r a g o g n a ( a r ). m o n : c on gl om er at o de l m on te llo ; o s p : c on gl om er at o di o so pp o; b g m : s in te m a di b or go d i m ez zo ; v m i: s in te m a di v ia d i m ol in ; a o n : s in te m a di a on ed is ; p li : s in te m a di p la in o; s in te m a di v ill uz za ; s n m : s in te m a d i s a n ta m a rg h e ri ta ; n d s : s in te m a d i c an od us so . 116 : ep is od i de ll’ ev ol uz io ne d el la p ia nu ra i n es am e (p er l a de sc riz io ne v ed i ca p. 6 ). b ) f ot o de lla s ca rp at a di v ia d i m ol in . g. paiero & g. monegato m a .s .l. light reddish brown (5yr6/4) colored. stratification is tilted and has an average dip of 30 degrees southeastward. the basal boundary is characterised by an angular unconformity of 15 degrees with osoppo conglomerate strata. the top of unit is an erosion surface. this unit represents a buried early alluvial fan sequence of arzino stream. 55..22.. vviiaa ddii mmoolliinn ssyynntthheemm ((vvmmii)):: outcropping next to via di molin, this unit is made by crudely-bedded gravel (gh) normally consolidated and clast-supported; clasts are subrounded, carbonate, granule to coarse cobble sized. matrix is silty sand. massive (sm) to planar cross-beds (sp) sandy levels, about 2 m thick, are interbedded. lower boundary does not outcrop; upper boundary is given by a weathered surface, developed on the deposits of this unit, with an argillic horizon about 50 cm thick and strong brown (7.5yr5/6) colored (fig. 5). the unit represents an arzino stream alluvial deposit. 55..33.. aaoonneeddiiss ssyynntthheemm ((aaoonn)):: outcropping from pinzano narrow to aonedis, it is made by stratified sandy gravel (gt), clast-supported to partially open-work, with subangolar to subrounded carbonate clasts (more than 95% of white or gray carbonate), medium pebble to cobble sized; massive sandy levels (sm) are common and have an average thickness of 1 meter. next to these ones some discontinuous horizons, rich of organic matter, are joined; one of these (rome1428) was dated >>4433..000000 yr bp. the lower boundary is an erosion surface, that northernside of ponte brook is emphasized by an angular unconformity that reaches 30° with borgo di mezzo synthem’s strata; the upper boundary is an alluvial erosion surface. unit is 15÷20 m thick and represents an arzino stream alluvial deposit. 55..44.. ppllaaiinnoo ssyynntthheemm ((ppllii)): this unit, outcropping from borgo di mezzo terrace slopes to aonedis slope, is made by crudely bedded (gh) sandy gravels, clast-supported; with subrounded tagliamento's basin clasts (polychromatic carbonates, siliceous sandstones, volcanites and metamorphites), medium pebble to fine boulder sized. deposits of this unit are easily distinguishable from the bottom and top arzino basin's ones for polychromic clasts typical of tagliamento basin. moreover, as notified by feruglio (1929a), in borgo di mezzo terrace slopes a strongly weathered massive and matrix-supported diamicton, rich in striated clasts, is present. both boundaries are erosion surfaces. in villuzza slope of ponte brook valley upper boundary is made by a buried soil 3.2 m thick, with a 180 cm argillic reddish brown (5yr5/4) colored horizon; the soil is developed on the deposits of this unit. average thickness is of 5-7 m. these deposits represent the evidence of the older glacial expansion so far observed in san pietro aonedis section. according to their stratigraphic position they are probably related with glacial ones of rio ponte section and here credited to the same unit. 55..55.. vviilllluuzzzzaa ssyynntthheemm ((vvllzz)): outcropping from pinzano narrow to aonedis, this unit is made by crudely-bedded stratified gravel (gh) to stratified gravel (gt), clast-supported to partially open-work, with some interbedded lenses of massive silty sand (sm); carbonate clasts, fine pebble to cobble sized, point out an arzino basin alluvial deposit. both boundaries are erosion surfaces. villuzza synthem is 5÷10 m thick and represents last alluvial depositional event clearly ascribing to arzino stream. 55..66.. ssaannttaa mmaarrgghheerriittaa ssyynntthheemm ((ssnnmm)): outcropping from rio ponte valley to aonedis slope; this unit is made by clast-supported massive gravel (gcm) to crudely bedded gravel (gh) with sandy matrix; clasts are subrounded, pebble to cobble sized; deposit is normally consolidated and locally weakly cemented. petrography of clasts point out a tagliamento basin origin. boundaries are erosion surfaces; between them the lower is easily locating by petrographic composition of clasts. it has an average conserved thickness of 5 meters. these deposits represent the outwash plain of glacial event, whose glacial deposits were described in santa margherita synthem in rio ponte section. inside ponte and fos incisions physical relationship of these deposits with glacial ones is visible; in these outcrops, gravels are coarser next to glacial deposits. 191 fig. 5 paleosol at aonedis synthem lower boundary in via di molin slope. vmi: via di molin synthem; aon: aonedis synthem. paleosuolo in corrispondenza del limite inferiore del sintema di aonedis sulla scarpata di via di molin. vmi: sintema di via di molin; aon: sintema di aonedis. the pleistocene evolution of arzino ... 55..77.. ccaannoodduussssoo ssyynntthheemm ((nnddss)): this unit outcrops at the top of sequence from san pietro to aonedis; it is made by clast-supported massive gravel (gcm) to crudely bedded gravel (gh) with tagliamento's basin subrounded clasts, medium pebble to boulder sized, with silty-sandy matrix; deposits are normally consolidated. basal boundary is an erosion surface over every present units; upper boundary is the topographic surface marked by a soil having dark yellowish brown (10yr4/4) to brown (7.5yr4/4) color. thickness of this unit increases downstream from 10 to 20 meters. these deposits represent the sandur of last glacial advance and they are heteropic with glacial deposits observed in ponte brook site. 66.. ddiissccuussssiioonn aanndd ccoonncclluussiioonn stratigraphic units and discontinuities recognised during geologic survey, supported by some chronological data, allow to distinguish several depositional and erosion episodes, from which it is possible to go back to the pleistocene evolution of this area. tectonic influence on deposits architecture nowadays visible is not marginal; presence of arba-ragogna thrust (zanferrari et alii, in prep.), traceable next to ponte brook valley (fig. 1), contributed to determine the stratigraphic differences existing between the two slopes of the same valley. a certain dating of ancient units, because of lack of chronological data and tectonic deformation undergone, seems not possible; then a relative chronology is presented; reliability became better for late pleistocene units. sequence of deposits outcropping in left tagliamento slope and its tributaries’ ones is held between two main boundaries: the lower is the erosion surface on osoppo conglomerate, an angular unconformity on which pleistocene sedimentation of arzino alluvial fan began, this boudary can be combined with miall (1996) 8th-order type (episode 1 in fig. 4a); the upper is topographic surface relative to last glacial maximum event in tagliamento basin and the late pleistocene holocene incision (6th-order type). borgo di mezzo synthem represents an apex alluvial fan sequence of arzino stream (episode 2 in fig. 4a), a part of the dip of the strata has probably a tectonic origin (fig. 4a). alteration of deposits, general steepness and its stratigraphic position at the base of the pleistocenic sequence allow to give to this synthem an early-middle pleistocene age. the southern side of ragogna hill has been contemporary interested by early stage of small alluvial fans, according to the classification after blair & mcpherson (1994); these fans were characterised by colluvial slides, debris flows and incised channel flows sedimentary processes (rio ponte unit). afterwards the trenching of borgo di mezzo synthem’s alluvial fan (episode 3 in fig. 4a) an aggradation took place, witnessed by via di molin synthem; it likely represents a distal fan which partially backfilled the shaped valley (episode 4 in fig. 4a); afterwards its deposits were pedogenized during a sedimentary stasis (episode 5 in fig. 4a). then aonedis synthem was deposited (episode 6 in fig. 4a). the sedimentary facies suggests a fan apex located more upstream than borgo di mezzo one, with several sandy beds and more sorted clast average. aonedis synthem lower boundary, clearly diachronic, is an angular unconformity, as to borgo di mezzo deposits, concerning a 7th order bounding surface. whereas weathered surface, that emphasizes boundary with via di molin synthem, can be combine with a 6th order one. stratigraphic position, besides chronological data (>43.000 yr bp), gives to aonedis synthem a middle pleistocene age, when arzino stream was still free to growing up its fan downstream of pinzano narrow. in southern side of ragogna hill went on rio ponte unit deposition. then first documented local glacial advance took place, represented by plaino synthem (episode 8 in fig. 4a); its basal boundary is an erosion surface (episode 7 in fig. 4a) and it does not give any information about relationship with aonedis synthem deposits; consequently the rank of boundary becomes vague. the deep evolution of upper boundary's paleosol and the strong reshaping allow to give a middle pleistocene age to this glacial unit. at the same time rio ponte unit aggradiation was stopped and buried by this glacial event, afterwards evolution of these small brooks have been constrained inside incisions in glacial deposits. later on a likely trenching phase happened (episode 9 in fig. 4a), on the terraced surfaces the weathering growing on; arzino stream probably still flew down pinzano narrow. then the backfilling of arzino and its scattering over the plain (villuzza synthem) represent last documented arzino stream sedimentary event (episode 10 in fig. 4a) out of pinzano narrow (zanferrari et alii, in prep.). lower surface of this synthem, marked by a deep paleosol, can be credited to a 7th order boundary. afterwards santa margherita synthem represents the second local glacial event (episode 12 in fig. 4a) well documented in the whole tagliamento morainic amphitheatre, even though deposits’ morphology is strongly reshaped. its basal erosion surface (episode 11 in fig. 4a) gives unfit informations about the relationships with deposits of villuzza synthem; however these alluvial deposits lay in the same stratigraphic position, then a partial heteropy cannot be excluded. these two synthems can ascribed to middle-late pleistocene for their stratigraphic position. after this another entrenchment took place (episode 13 in fig. 4a), consequently a sedimentary stasis is documented, inside ponte valley, by a paleosol on glacial deposits of santa margherita synthem, that can be related to a 6th order bounding surface. then the last local glacial event (episode 14 in fig. 4a) covered deposits of the whole area (canodusso synthem). this depositional episode represents the last glacial maximum in tagliamento amphitheatre and here its age fits in 14c calibration range 23.040-22.240 (±1σ, yr bp) after stuiver et al i i (1998). westerly, in tagliamento hydrographic right, the relevant sandur is made by deposits that are heteropic with alluvial fan deposits of meduna stream, whose 14c ages give the same time range (aviglianoet alii, 2002). during final times of lower pleistocene and in the whole holocene, after glacial retreat, entrenchment of watercourses permits the formation of the high fluvial slopes (episode 15 in fig. 4a), located southward from pinzano narrow for about 18 km; thin holocene deposits 192 g. paiero & g. monegato are present inside mordaro, ponte and fos brooks valleys (episode 16 in fig. 4a). bbiibblliiooggrraapphhyy avigliano r., calderoni g., monegato g. & mozzi p. (2002) – the late pleistocene-holocene evolution of the cellina and meduna alluvial fans (friuli, ne italy). mem. soc. geol. it., 5577 (1): 133-139. baggio p., bellino l., carraro f., fioraso g., gianotti f. & giardino m. (1997) schede per il rilevamento geologico delle formazioni superficial i. i l quaternario it. j. quat. sc., 1100 (2): 655-680. bini a. & orombelli g. (1988) – considerazioni sulla terminologia dei sedimenti glaciali. “natura bresciana” ann. mus. civ. sc. nat., brescia, 2244: 213-216. blair t.c. & mcpherson j.g. (1994) alluvial fans and their natural distinction from rivers based on morphology, hydraulic processes, sedimentary processes and facies assemblages. j. sed. res., aa6644: 450-489. blair t.c. & mcpherson j.g. (1999) grain-size and textural classification of coarse sedimentary particles. j. sed. res., 6699: 6-19. boyce j.i. & eyles n. (2000) architectural element analysis applied to glacial deposits: internal geometry of a late pleistocene till sheet, ontario, canada. gsa bull., 111122:: 98-118. carraro f. & petrucci f. (1977) geologia dei depositi superficiali: anfiteatro morenico. in: b. martinis (ed.): studio geologico dell’area maggiormente colpita dal terremoto friulano del 1976. riv. it. strat. paleont., 8822: 193-393, milano. carraro f. & petrucci f. (1982) tentative assessment of the deformation of a morainic amphitheatre: the tagliamento amphitheatre (italy). z. geomorph. n. f., 2266: 331-341. comel a. (1955) monografia sui terreni della pianura friulana. ii. genesi della pianura centrale connessa all ’antico sistema fluvioglaciale del tagliamento. n. ann. ist. chim. agr. sperim. gorizia, 66: 1-216. comel a. (1956) monografia sui terreni della pianura friulana. iii. genesi della pianura occidentale costruita dal meduna, dal cellina e da corsi d'acqua minori. n. ann. ist. chim. agr. sperim. gorizia, 77: 5-93. croce d. & vaia f. (1985) aspetti geomorfologici dell'anfiteatro tilaventino (friuli). gortania-atti. mus. friulano st. nat., 77: 5-36. dalla vecchia f.m. & rustioni m. (1996) mammalian trackways in the conglomerato di osoppo (udine, ne italy) and their contribution to its age determination. mem. sci. geol., 4488: 221-232, padova. di bernardo f., florean m. & vaia f. (1998) – i conoidi del tagliamento e del torre: aspetti evolutivi. gortania atti museo friul. storia nat., 2200: 23-39. eyles n., eyles c.h. & miall a.d. (1983) lithofacies types and vertical profile models; an alternative approach to the description and environmental interpretation of glacial diamict and diamictite sequences. sedimentology, 3300: 393-410. feruglio e. (1920) i terrazzi della pianura pedemorenica friulana. uff. idrogr. r. magistrato acque venezia, 107: 1-93. feruglio e. (1925) carta geologica delle tre venezie. foglio 25 udine. uff. idrogr. r. magistr. acque di venezia. venezia. feruglio e. (1929a) nuove ricerche sul quaternario del friuli. giorn. geol., s. 2, 4:1-36, bologna. feruglio e. (1929b) note illustrative della carta geologica delle tre venezie: foglio "udine". uff. idrogr. r. magistrato acque venezia, 77 pp., venezia. gortani m. (1959) carta della glaciazione würmiana in friuli. rend. atti. acc. sci., ist. bologna, s. 11, 66:1-11. issc – international stratigraphic subcommission on stratigraphic classification (1994) – international stratigraphic guide (isg). second edition, pp. 213. massari f., grandesso p., stefani c. & jobstraibizer p.g. (1986) a small polyhistory foreland basin evolving in a context of oblique convergence: the venetian basin (chattian to recent, southern alps, italy). in: allen p. & homewood p. (eds.) foreland basins. spec. public. int. ass. sediment., 8: 141-168, blackwell scientific publ., oxford. miall a.d.(1996) the geology of fluvial deposits. springer-verlag, berlin heidelberg. m.u.r.s.t. (1997) – carta altimetrica e dei movimenti verticali del suolo della pianura padana. 3 sheets, 1:250.000 scale; s.el.ca., firenze. penck a. & brückner e. (1909) die alpen im eiszeitalter. 3 vol., 1199 pp., tauchnitz, leipzig. sacco f. (1937) il glacialismo veneto. l'universo, 77: 1-40, firenze. stuiver m., reimer p.j., bard e., beck w.j.; burr g.s., hughen k.a., kromer b., mc cormac g., van der plicht j. & spurk m. (1998) "intcal98 radiocarbon age calibration, 24,000–0 cal bp" radiocarbon, 4400: 1041-1083. taramelli t. (1875) dei terreni morenici e alluvionali del friuli. ann. r. ist. tecn. udine, 88: 1-91. tellini a. (1892) descrizione geologica della tavoletta "majano". in alto, 33: 18-25, 44-48,76-81. zanferrari a., marchesini a., monegato g. & avigliano r. (2000) – il progetto carg-fvg: la nuova cartografia geologica nazionale nella regione friuli – venezia giulia. rass. tecn. del friuli venezia giulia, llii ((66)): 23-26. zanferrari a., poli m.e. & rogledi s. (2002) the external thrust-belt of the eastern southern alps in friuli (ne italy). mem. sci. geol., 5544: 159-162. zanferrari a., avigliano r., calderoni g., carraro f., grandesso p., marchesini a., monegato g., paiero g., poli m.e., ravazzi c. & stefani c. (in prep.) – note illustrative della carta geologica d’italia alla scala 1:50.000: foglio 065 “maniago”. servizio geologico d’italia – regione autonoma friuli – venezia giulia. zenari s. (1927) carta geologica delle tre venezie, foglio "maniago". uff. idrogr. r. magistrato acque venezia. 193 ms. ricevuto il 6 maggio 2003 testo definitivo ricevuto il 3 settembre 2003 ms. received: may 6, 2003 final text received: september 3, 2003 the pleistocene evolution of arzino ... impaginato carrara eelleemmeennttii ggeeoollooggiiccii ssuullllaa nneeccrrooppoollii eenneeoolliittiiccaa ddeellllaa sseellvviicccciioollaa ((iisscchhiiaa ddii ccaassttrroo - vviitteerrbboo)) ccllaauuddiioo ccaarrrraarraa11,, eeuuggeenniioo cceerriillllii22 && vvllaaddiimmiirroo vveerrrruubbbbii33 1via c. balbo, 35 00184 roma; 2soc. coop. arx, via s. giovanni in laterano 210, 00184 roma; 3enea-c.r. casaccia, via anguillarese 301, 00060 roma riassunto la necropoli eneolitica della selvicciola (metà del iv millennio fine del iii millenio a.c.) è situata a circa 7 km a so di ischia di castro (viterbo) sulla sponda sinistra del fosso strozzavolpe. lo studio dell'area, ancora in corso, è finalizzato alla definizione delle caratteristiche geo-morfologiche dell'ambiente del sito al momento dell'instaurarsi della necropoli e dell'interazione tra l'attività sorgentizia presente nell'area e quella antropica. le tombe della necropoli sono state scavate al di sotto di una copertura di travertino, che funge da tetto, facente parte dell'estesa placca travertinosa di monte doganella-monte canino, di età compresa tra il pleistocene medio e l'olocene, e localmente ancora in via di deposizione.il substrato vulcanico pleistocenico che ospita le tombe è fortemente pedogenizzato ed interessato da una superficie di erosione areale datata tra il pleistocene superiore e l'olocene, presente in tutta l'area. lo studio della stratigrafia del sito ha permesso di identificare livelli di limi calcarei organici contenuti nella parte basale del travertino che copre le tombe, mentre nella porzione superiore, interessata da cavità carsiche, è presente un suolo organico bruno-nerastro. la datazione radiocarbonio di detti livelli (rispettivamente cal bp 13180-11860 e cal bp 2956-2774) suggerisce che il travertino, nel sito, ha iniziato a deporsi verso la fine del tardiglaciale, prima dell'instaurarsi della necropoli, per proseguire fino al tardo olocene a necropoli abbandonata. sulla base dello studio di facies del travertino si può desumere che l'ambiente di deposizione all'inizio fosse fluviale fino a palustre con piccoli laghi e pozze. durante la frequentazione della necropoli doveva essere caratterizzato dalla presenza di sorgenti ancora attive, con locali pozze ed acque correnti canalizzate, probabilmente utilizzate e controllate dall'uomo, come è stato osservato in altre località vicine. i banchi più superficiali del travertino sono interessati da fenomeni carsici, connessi sia a una fase erosiva lineare molto intensa che ha approfondito notevolmente la rete idrografica e ha dissecato la copertura di travertino e il substrato vulcanico, sia a processi pedogenetici che hanno dato luogo al suolo bruno organico. abstract geological elements on the eneolitic necropoli of selvicciola (ischia di castro viterbo). the eneolitic necropoli of selvicciola (middle of the iv millenium end of the iii millenium a.c.) is located at about 7 km sw ischia di castro (viterbo) on the left side of fosso strozzavolpe. the study of the area, still continuing, is aimed at the definition of geo-morphological features of the environment at the time of establishment of the necropoli and of interaction between thermal springs present in the area and anthropogenic activity. the tombs of the necropoli have been dug under a travertine cover, that acted as a roof, and is part of the very extensive travertine plate of canino, of an age ranging between middle pleistocene and holocene and in places still precipitating. the pleistocene volcanic substrate containing the tombs is strongly pedogenized and cut by an irregular erosion surface, occurring in the whole area of canino, dated between upper pleistocene and holocene. the study of stratigraphic sections allowed the recognition of calcareous organic silty levels in the basal part of the travertine cover, whereas in the uppermost portion, affected by karstic cavities, a blackish-brown organic soil occurs. radiocarbon datings of the above-mentioned organic levels and soil (respectively cal bp 13180-11860 and cal bp 2956-2774) suggest that the travertine began to deposit towards the end of lateglacial, before the establishment of the necropoli, and carried on until the late holocene, until its abandonment. the facies analysis of travertine suggests that at the beginning the deposition environment could be fluvial to paludal. during the attendance of the necropoli the environment could be characterized by the occurrence of still active isolated springs, forming small running water resurgences and pools, likely utilized and controlled by human activity, as in other adjoining localities has been observed. the uppermost layers of the travertine cover, moreover, are affected by karstification, connected to a new erosion phase that caused the watertable lowering, the strong deepening of the hydrographic network and the dissection of the travertine cover and the substrate, as well as to pedogenetic processes that gave rise to the brown organic soil. parole chiave: archeologia, stratigrafia, travertino, ambiente di deposizione, pleistocene superiore, olocene, italia centrale. keywords: archeology, stratigraphy, travertine, deposition environment, upper pleistocene, holocene, central italy il quaternario italian journal of quaternary sciences 1155(2), 2002, 221-227 iinnttrroodduuzziioonnee la presente nota vuole illustrare i risultati preliminari di una ricerca geo-archeologica sul sito "la selvicciola" di ischia di castro (viterbo) iniziata alcuni anni or sono e ancora in corso, finalizzata alla definizione delle caratteristiche dell'ambiente geomorfologico e geologico nell'olocene, che ha visto l'instaurarsi e la frequentazione della necropoli eneolitica, nonché degli insediamenti di età romana e più recenti, parzialmente sovrapposti alla stessa. in particolare si é cercato di determinare, anche cronologicamente, i rapporti tra la deposizione del travertino che copre e in parte ingloba le tombe della necropoli, e l'interazione tra attività sorgentizia ed attività antropica. lo studio è stato condotto da ricercatori dell'enea in stretta collaborazione con archeologi della soprintendenza archeologica per l'etruria meridionale ed archeologi e geologi della società cooperativa arx. il presente lavoro è stato pubblicato con il sussidio dell'enea e dell'istituto di ricerche sulla tettonica recente del cnr. 222 c. carrara, e. cerilli & v. verrubbi iinnqquuaaddrraammeennttoo ggeeoollooggiiccoo il sito archeologico della selvicciola è ubicato 7 km circa a so di ischia di castro e 1 km circa a sse di località colle vepre, sulla sponda sinistra del fosso strozzavolpe, aff luente del fiume fiora (foglio topografico 1:100.000, n. 136, tuscania; a cavallo delle tavolette 1:25.000, iv se, ponte s. pietro, e iii ne, riminino). il sito è compreso nell'area più settentrionale di una estesa placca di travertino (fig. 1), che si estende pressoché continua in direzione meridiana per circa 14 km e in direzione longitudinale per 6÷7 km ed è limitata a nord dal fosso strozzavolpe, ad est dal gruppo del monte canino, a sud dal fosso timone e ad ovest dal fiume fiora. la placca travertinosa affiora in parte al di sopra dei prodotti vulcanici dei monti vulsini di età pleistocenica, in parte su sedimenti mesocenozoici. la placca mostra una potenza variabile da pochi metri nelle parti periferiche fino a oltre 100 metri in località poggio olivastro, presso la dorsale monte doganella-monte canino, al cui sistema idrogeologico e strutturale è geneticamente connessa. la deposizione del travertino, infatti, è legata all'emergenza di acque termali ricche di sali di calcio e di anidride carbonica lungo le faglie a direzione appenninica ed antiappenninica, che limitano e suddividono in blocchi la suddetta dorsale (carrara, 1994). la parte più settentrionale della placca è limitata da una evidente scarpata morfologica alta alcuni metri sulla piana antistante, che in direzione grosso modo longitudinale corre da c.se riminino fino ai piedi di poggio olivastro. l'area è compresa tra le quote 120 e 270 m s.l.m. ed è caratterizzata da estesi espandimenti travertinosi a giacitura per lo più orizzontale, sovrapposti gli uni agli altri, e limitati da evidenti scarpate morfologiche. queste forme deposizionali tabulari, solcate da una rete idrografica molto incisa ed irregolare, drenante verso il fosso strozzavolpe e il fiume fiora, sono spesso costituite da più corpi travertinosi lobati, talora interdigitati, progradanti da nne verso sso. nell'area tra il fosso strozzavolpe e il monte fumaiolo si riconoscono, anche se rimodellati, i relativi coni sorgentizi, isolati o in gruppi allineati a formare veri e propri ridges fissurali, che presentano direzioni appenniniche (no-se) e circa-antiappenniniche (nne-sso). probabilmente ricalcano strutture tettoniche sepolte attraverso le quali le acque responsabili della deposizione del travertino raggiungevano la superficie. nel travertino sono diffuse anche forme carsiche tondeggianti che rappresentano inghiottitoi o sono connesse con crolli della volta di cavità e grotte. l'area del sito è situata sulla sponda sinistra del fosso strozzavolpe a poche decine di metri dal fosso fig. 1 localizzazione della necropoli della selvicciola nella placca di travertino di canino (viterbo). 1. formazione dei travertini; 2.substrato; 3. limite di formazione, a: certo, b: presunto; 4. scarpata di travertino su terrazzo fluviale, a:certa, b:presunta; 5. scarpata nei corpi di travertino, a: certa, b: presunta; 6. isoipsa; 7. corso d'acqua; 8. cono sorgentizio; 9. corpo fissurale; 10. cavità carsica e/o inghiottitoio; 11. sorgente; 12. traccia di profilo geologico. localisation of the selvicciola necropoli within the travertine plate of canino (viterbo). 1.travertine formation; 2. substrate; 3. limit of formation, a: evident, b: inferred; 4. scarp of travertine on fluvial terrace, a: evident, b: inferred; 5. scarp in travertine bodies, a: evident, b: inferred; 6. isohypse; 7. stream; 8. cone-type spring deposit; 9. fissure ridge deposit; 10. karst sinkhole and cave; 11. spring; 12. geological section. stesso (fig. 1). la stratigrafia locale è di difficile ricostruzione poiché tutta l'area è stata interessata da intensa attività antropica dalla preistoria ad oggi. particolarmente profonde sono state le modificazioni morfologiche e idrografiche attuate nell'area in seguito all'opera di bonifica iniziata successivamente al secondo conflitto mondiale. durante detta bonifica è stata quasi totalmente asportata la copertura travertinosa che poggiava sul substrato vulcanico, per permettere lo sfruttamento agricolo del suolo sottostante molto fertile, sviluppatosi su parent material vulcanico. lavori di sbancamento di questo genere si effettuano ancora oggi nelle zone di maggiore attività agricola. sono rimasti integri solo pochi lembi di travertino, in particolare quelli troppo spessi per poter essere rimossi o quelli connessi con coni sorgentizi o con canali profondi. nell'area del sito, infatti, sono conservate soltanto due strutture di travertino, distanti 100 m circa l'una dall'altra, allineate in direzione no-se, di forma tondeggiante o mammellonaretabulare. le due strutture, che presentano giacitura periclinale degli strati, più fortemente immergenti verso il fosso strozzavolpe, rappresentano ciò che rimane di due coni sorgentizi, nei quali si riconoscono ancora gli orifizi di emergenza delle acque, allineati secondo due sistemi di fratture verticali, orientati n55e e n60o (fig.2). la struttura orientale è stata quasi completamente smantellata e ridotta ad un ammasso isolato, ora molto vegetato, di blocchi di travertino, mentre quella occidentale ha subito l'asportazione della parte sudoccidentale fino al substrato, esposto lungo un taglio netto, verticale, lungo alcune decine di metri. proprio in questo tratto di substrato "scoperchiato", quasi a ridosso del taglio, è ubicata la necropoli attualmente in via di studio da parte degli archeologi, che secondo datazioni 14c su ossa umane è stata attiva dall'eneolitico fino all'i223elementi geologici sulla necropoli eneolitica ... nizio del bronzo antico (3500-2000 a.c.); mentre sulla parte nord-orientale del cono sorgentizio occidentale fino alla sponda sinistra dello strozzavolpe insiste una villa romana con annesse relative terme attribuita a un periodo repubblicano-imperiale, frequentata fino in tempi paleocristiani ed anche in periodo longobardo. la serie stratigrafica locale, messa in evidenza lungo il fosso strozzavolpe e in alcuni pozzetti conoscitivi scavati nel sito archeologico e profondi 2-4 m, è la seguente dal basso verso l'alto (fig.3a): a1) substrato vulcanico costituito da tufi stratificati con pomici; tufi pisolitici e cineritici predominanti nella parte inferiore, mentre in quella superiore prevalgono tufiti stratificate deposte in ambiente fluvio-lacustre. la parte sommitale del substrato vulcanico è interessata da una superficie di erosione molto incisa ed irregolare, con presenza di canalizzazioni e depressioni più o meno sviluppate. essa è interessata da: a2) sedimenti marnoso-argilloso-tufacei, misti a colluvio di suolo, sui quali si sviluppa un paleosuolo, di spessore molto variabile da pochi decimetri a qualche metro, dove non decapitato, di colore bruno-rossiccio, acalcareo, contenente frammenti di vulcaniti alterate. la parte alta di questo paleosuolo affiora anche sotto al travertino, laddove esso è stato interessato dal taglio netto a ridosso della necropoli e menzionato precedentemente. a3) copertura di travertino, a giacitura orizzontale o leggermente ondulata, di spessore variabile da pochi decimetri ad alcuni metri. presso le strutture sorgentizie e nel fosso strozzavolpe il travertino raggiunge uno spessore di 4-5 m ed oltre. la parte inferiore è costituita prevalentemente da sabbie e limi calcarei stratificati, alla base dei quali, a contatto con il substrato vulcanico, si notano livelli calcarei argilloso-marnosi di colore marroncino fino a nerastro, contenenti abbondante frazione detritica, rappresentata da granuli ossidati di vulcaniti e di minerali vulcanici (pirosseno, miche molto alterate, feldspati), di granuli di calcari e materiale organico. sono sterili, invece, dal punto di vista paleontologico. la parte superiore è costituita da banchi di travertino fitoermale e microermale, molto diagenizzati, compatti, di colore giallastro o marroncino,talora bruniccio, alternati a sottili strati di facies algali e batteriche, piuttosto porose e "sporche", con sviluppo locale di tessiture stromatolitiche a lamine chiare e scure. nei pressi dei coni sorgentizi sono diffuse le tessiture stromatolitiche a lamine sottili, con sviluppo di microvaschette a giacitura periclinale. le facies di travertino presenti nella sezione sembrano indicare per la parte basale un ambiente di sedimentazione prevalentemente fluviale, ad acque correnfig. 2 la struttura sorgentizia occidentale del sito con sistema di fratture verticali orientate n55e e n60o. sullo sfondo i resti della villa con terme di età repubblicanaimperiale. western spring structure affected by vertical fractures oriented n55e and n60w. in the background the remains of a roman villa and baths of republic-imperial age. 224 ti, scarsamente vegetato e sterile, con apporti variabili di materiale detritico allotigeno. la parte alta è caratterizzata da un ambiente prevalentemente palustre, con sviluppo di vasche e pozze ad acque poco mosse, in presenza, tuttavia, anche di locali episodi di acque sorgentizie con flussi correnti su pendio lieve, ben ossigenate e vegetate. in un'altra sezione ubicata a un centinaio di m a se della precedente e rappresentante la parte più superficiale della serie travertinosa, che copre in parte la necropoli, si osservano dal basso in alto (fig. 3b): b1) substrato vulcanico costituito da tufiti e limi tufacei giallastri, localmente cineritici, da fini a grossolani, interessati da una superficie di erosione ondulata che li incide irregolarmente. detti sedimenti sono alquanto rubefatti in superficie; localmente, nelle depressioni più accentuate, è presente lo stesso paleosuolo, bruno-rossiccio, acalcareo, descritto nel punto 2 della sezione precedente (vedere anche in fig. 5, simboli 3 e 4). b2) segue un banco di travertino di 2 m circa di spessore, costituito prevalentemente da facies microe fitoermali di colore marroncino, a strutture vegetali calcificate in posizione di crescita, con sottili alternanze ad andamento lenticolare di limi calcarei a fauna dulcicola, rappresentata da un'associazione a lymnaea stagnalis, lymnaea peregra e pseudoamnicola in proporzioni variabili e scarsi ostracodi. la parte superiore di detto banco di travertino passa verso l'alto a una facies detritica molto "sporca" e frammentata, mentre la parte inferiore è interessata da cavità carsiche irregolari, tappezzate da incrostazioni di cementi calcarei e piccoli speleotemi di deposizione tardiva. dette cavità sono parzialmente o completamente occupate da un suolo calcareo, marnoso-argilloso, bruno-nerastro, organico (fig. 4), contenente resti di fauna dulcicola simile a quella descritta precedentemente e una frazione detritica costituita da elementi spigolosi di travertino e di incrostazioni calcaree su supporto vegetale e da scarsi granuli di feldspato, di pirosseni neri e verdastri e rari granuli subarrotondati di quarzo. l'ambiente di sedimentazione sembra essere prevalentemente palustre ad acque poco mosse, in presenza, tuttavia, di episodi di acque correnti, ben ossigenate, vegetate e colonizzate da malacofauna dulcicola. llaa nneeccrrooppoollii la necropoli preistorica della selvicciola, scoperta nel 1987, è ancora in corso di esplorazione (cerilli et al., 1993; conti, persiani & petitti, 1997; petitti et al., 1999). a tutt'oggi comprende 31 tombe scavate e almeno 3 c. carrara, e. cerilli & v. verrubbi fig. 3 sezioni stratigrafiche nel sito; a) lungo il fosso strozzavolpe, b) nell'area orientale della necropoli. 1. suolo misto a frammenti di travertino; 2. suolo calcareo organico; 3. limi calcarei con fauna dulcicola; 4. travertino fitoermale e microermale; 5. limi e sabbie calcarei con lenti di materiale organico; 6. tufiti stratificate; 6a. paleosuolo 7. superficie di erosione; 8. campioni datati. stratigraphic sections: a) along the fosso strozzavolpe, b) in the eastern area of the site. 1.soil with travertine fragments; 2. calcareous organic soil; 3. calcareous silts with freshwater fauna; 4. phytohermal and microhermal travertine; 5. calcareous silts and sands with lenses of organic material; 6. reworked tuffs; 6a. palaeosol; 7. erosion surface; 8. dated sample. 225 ancora da scavare: si tratta di una delle necropoli più grandi attribuite alla cosiddetta cultura di rinaldone, ovvero alla facies classica dell'età del rame sul versante medio-tirrenico della penisola italiana. in base alle datazioni radiometriche effettuate su resti antropici può essere attualmente inquadrata tra la metà del iv millennio e la fine del iii millennio a.c. le tombe presentano l'aspetto tipico delle strutture funerarie di questo periodo; infatti si tratta delle cosiddette "grotticelle artificiali": pozzetti scavati perpendicolarmente al terreno consentono di accedere a piccoli ambienti ipogei a pianta ovale/circolare con volta arrotondata, la porta tra la camera ed il pozzetto veniva chiusa da lastre di travertino, bloccate da accumuli di pietre sistemati nel pozzetto prima che quest'ultimo venisse reinterrato (fig. 5). elementi geologici sulla necropoli eneolitica ... fig. 4 suolo organico bruno-nerastro nelle cavità della porzione superficiale della copertura travertinosa. the blackish-brown organic soil in the karstic cavities of the uppermost portion of travertine cover. fig. 5 ricostruzione ipotetica del piano di campagna al momento dello scavo delle tombe a "grotticella artificiale" (dall'archivio soprintendenza beni archeologici per l'etruria meridionale, modificata). 1. suolo e materiale detritico; 2. travertino; 3. paleosuolo; 4. tufiti stratificate; 5.vestibolo; 6. tomba sbarrata con lastra di travertino e massi accatastati contro; 7. sbancamento di età romanarepubblicana che ha determinato il fronte della basis villae. hypothetical reconstruction of ground surface at the moment of the excavation of "grotticella artificiale" type tombs (from archives soprintendenza beni archeologici per l'etruria meridionale, modified). 1. soil and detrital material; 2. travertine; 3. palaeosol; 4. reworked stratified tuffs; 5. vestibule; 6. tomb entrance blocked with a travertine slab and boulders; 6.cut from the roman-republic age that determined the front of basis villae. 226 l'elemento di novità apportato dallo scavo e dallo studio della selvicciola è costituito da una visione radicalmente nuova dei rituali di deposizione e quindi dei processi di formazione dei depositi archeologici: infatti puntuali tecniche applicate allo scavo hanno documentato un rituale che prevedeva anche più di un intervento sulle ossa già scarnificate, con il disturbo dell'ordine anatomico, la dislocazione dei resti umani, a volte anche il rimescolamento tra resti di individui diversi. purtroppo le vicissitudini subite non solo dalla selvicciola ma anche da altre necropoli eneolitiche non consentono al momento di capire se, oltre a questa realtà ipogea, la necropoli comprendesse anche strutture e spazi sulla superficie del terreno: la ricostruzione dei processi di deposizione degli inumati induce in realtà ad ipotizzare che la necropoli arrivata fino a noi corrisponda solo ad una parte di un complesso più ampio. eelleemmeennttii ccrroonnoollooggiiccii ee ddiissccuussssiioonnee un campione prelevato dai livelli argilloso-marnosi contenenti materia organica brunastra alla base del travertino affiorante lungo il fosso strozzavolpe, a contatto con il substrato vulcanico, è stato datato con il metodo 14c:l'età convenzionale è risultata 10680+/-260 bp (cal bp 13180-11860, stuiver et al., 1998; beta analytic inc.-145524). si può presumere, quindi, che, nell'area considerata, il travertino abbia cominciato a deporsi sopra il substrato vulcanico più o meno rimaneggiato ed inciso, verso la fine del tardiglaciale. la fase erosiva precedente alla venuta del travertino nell'area della selvicciola può essere correlata con quella messa in evidenza a poggio olivastro e altrove nell'area di canino (carrara, 1994). l'età ottenuta rappresenta, quindi, un ulteriore conferma della presenza, nell'area in studio, di un'importante e lunga fase erosiva che, sebbene non sia esattamente coeva in tutte le parti dell'area, si situa generalmente tra la fine del pleistocene superiore e l'olocene. un campione del suolo bruno-nerastro organico contenuto nelle cavità carsiche della serie travertinosa superficiale che ricopre in parte la necropoli eneolitica (sezione b2) ha dato un'età radiocarbonio di 2770+/-45 bp (cal bp 2956-2774, stuiver et al., 1998; scottish univ.aa-44394). detta datazione indica probabilmente un termine comprensivo della deposizione del travertino alto, che è andato soggetto, durante la deposizione, non solo a fenomeni carsici di dissoluzione e riprecipitazione, ma anche alla formazione del suolo organico datato. generalmente, infatti, i processi di questo tipo iniziano immediatamente dopo la deposizione del travertino o, addirittura, sono contemporanei alla stessa (carrara, 1998) e si influenzano a vicenda. il processo carsico potrebbe essere stato innescato dall'abbassamento della falda causato dall'inizio dell'incisione fluviale ed essere stato favorito, inoltre, dalla pedogenesi. se ne deduce che, all'atto dell'impostazione della necropoli (circa 3500 a.c./ 5500 bp), l'area era già parzialmente ricoperta da travertino, che ha continuato a deporsi fino a prima di 3000 anni bp circa. ciò, da un lato permette di affermare che le tombe della necropoli sono state scavate nelle tufiti stratificate del substrato sotto il travertino, che fungeva da tetto compatto e resistente delle stesse (senza il quale le tombe sarebbero state velocemente cancellate dall'erosione, data la scarsa coesione e compattezza dei sedimenti tufacei), dall'altro lato ci permette di ipotizzare che durante la frequentazione della necropoli e successivamente, in alcune parti dell'area in studio, doveva essere ancora presente una certa attività sorgentizia, che dava luogo a locali e modesti corpi di travertino. non si può escludere, peraltro, che le acque fossero utilizzate e controllate dall'uomo, come è avvenuto in altre località (carrara, ciuffarella & paganin, 1998) e come suggerisce la presenza nell'area della necropoli di una villa con annesse relative terme di età repubblicana-imperiale, poste nelle immediate adiacenze della necropoli. la placca di travertino lungo il fosso strozzavolpe è fortemente dissecata; il torrente ha inciso non solo tutto lo spessore del travertino, ma si è approfondito nel substrato vulcanico nel quale attualmente scorre, a una decina di metri sotto il livello della superficie sommitale della placca. la fase erosiva lineare,che ha interessato l'area di deposizione del travertino, dato il carattere netto, non degradato, subverticale delle pareti delle incisioni, deve essere stata intensa e continua; probabilmente è ancora in corso, visto che sul letto del torrente si osservano soltanto scarsissimi ed esigui depositi alluvionali e che attualmente l ' incisione del fosso strozzavolpe provoca il crollo di una parte delle strutture della villa romana. cronologicamente, quindi, la fase erosiva si colloca nel tardo olocene, in corrispondenza di una fase di notevole diminuzione e/o cessazione completa della deposizione del travertino, già osservata e descritta in altri luoghi nello stesso periodo di tempo (carrara, 1994 e 1998). ccoonncclluussiioonnii le tombe della necropoli della selvicciola, attiva dall'eneolitico al bronzo antico (3500-2000 a.c.), sono state scavate al di sotto di una copertura di travertino, dello spessore variabile da pochi decimetri ad alcuni metri, al contatto del substrato vulcanico pleistocenico dei monti vulsini, costituito da tufi rimaneggiati intensamente pedogenizzati ed interessati da un'evidente superficie di erosione areale, presente in tutta l'area di canino, cronologicamente compresa tra la fine del pleistocene superiore e l'olocene. la deposizione del travertino è iniziata con sabbie e limi calcarei misti a materiale argilloso e detritico più grossolano con sottili livelli di materia organica, per proseguire poi con facies fitoermali e microermali prevalenti. la parte più alta della copertura di travertino è rappresentata da facies microe fitoermali "sporche", alternate a livelli di limi calcarei a fauna dulcicola ed è interessata da cavità carsiche irregolari, tappezzate da incrostazioni di cementi tardivi e riempite da un suolo organico bruno-nerastro. datazioni radiocarbonio sui livelli organici della base e della parte alta della placca di travertino suggeriscono che il deposito nell'area del sito abbia cominciato a formarsi verso la fine del tardiglaciale (cal bp 1318011860) per proseguire fino al tardo olocene (cal bp 2956-2774), allorché subentra una fase di stasi nella deposizione; fase, peraltro, nota in altre località di affioramento di depositi di travertino e connessa con più fattori di carattere idro-geologico e climatico, nonché con c. carrara, e. cerilli & v. verrubbi quello antropico (goudie,viles & pentecost, 1993). più o meno contemporaneamente l'area è soggetta ad un'intensa fase erosiva lineare che approfondisce notevolmente la rete idrografica, disseccando la copertura di travertino ed innescando in essa fenomeni carsici, favoriti oltretutto dal processo pedogenetico. rriinnggrraazziiaammeennttii gli autori ringraziano la s.a.e.m. per il consenso alla pubblicazione e la dr.ssa patrizia petitti per le notazioni archeologiche. aauuttoorrii cciittaattii carrara c.(1994) i travertini di canino (viterbo, italia centrale): elementi di cronolitostratigrafia, di geochimica idotopica e loro significato ambientale e climatico. il quaternario, 77(1), 73-90. carrara c. (1998) i travertini della valle del pescara tra popoli e tor de' passeri (abruzzo, italia centrale). il quaternario, 1111(2), 163-178. carrara c., ciuffarella l. & paganin g.(1998) inquadramento geomorfologico e climaticoambientale dei travertini di rapolano terme (si). il quaternario, 11(2), 319-329. cerilli e;, conti a. m., macchiarelli r., persiani c., petitti p. & salvadei l. (1993) rapporto preliminare sugli scavi eseguiti nella necropoli eneolitica della selvicciola (ischia di castro). preistoria e protostoria in etruria atti del i incontro di studi, la cultura di rinaldone ricerche e scavi, 75-84. conti a. m., persiani c. & petitti p. (1997) i riti della morte nella necropoli eneolitica della selvicciola (ischia di castro, viterbo). origini, 2211, 169-185. goudie a.s., viles h.a. & pentecost a. (1993) the late-holocene tufa decline in europe.the holocene, 33(2), 181-186. petitti p., cerilli e., conti a. m. & persiani c. (2000) la necropoli eneolitica della selvicciola (ischia di castro vt): i nuovi scavi. in: recenti acquisizioni, problemi e prospettive della ricerca sull'eneolitico dell'italia centrale, atti dell'incontro di studio, arcevia 14-15 maggio 1999, a cura di m. silvestrini, 179-189. stuiver m., reimer p. j., bard e., burr g. s., hughen k. a., krome b., mckormac g., van der plicht j. & spurk m. (1998) intcal98 radiocarbon age calibration, 24.000-0 bp. radiocarbon, 4400, 10411083. 227 ms. ricevuto il 1° settembre 2002 testo definitivo ricevuto il 22 ottobre 2002 ms. received: september 1, 2002 final text received: october 22, 2002 elementi geologici sulla necropoli eneolitica ... imp.colorti_barca_melis 87 1. introduction the new sheet “557” cagliari (carg project) produced a map of the quaternary syntems, however the results of the new radiometric datings were not exhaustive and sometimes contradictory. the groups working on continental and marine areas reached different conclusions on the chronology of the deposits: some coastal deposits have been included in the subsynthem of cala mosca (tyrrhenian) although we should refer them to the holocene. however, the distribution of the tyrrhenian deposits was reduced and the is arenas beach ridge grouped within the holocene. we report the elements supporting a holocene age for the coastal deposits. 2. geological setting the campidano is a plio-pleistocene nnw-sse oriented subsiding basin. early pliocene marine sediments crop out on the western side at capo frasca and capo s.marco up to 50 m asl. early pliocene sediments with globorotalia margaritae, puncticulata and crassaformis have been found at depth in the cagliari gulf (murru, 1983) and in the oristano 1 and 2 boreholes (727 and -666 m respectively; (pomesano-cherchi, 1971) (fig.1a). in the oristano 1, these sediments are covered with basalts, similar to those dated at 3 ma in the sinis peninsula. they are in turn overlaid by continental deposits suggesting a great mobility of the campidano. along the cagliari coast, nne-sse normal faults, that in the nearby villacidro sheet cut late pleistocene alluvial fan deposits, drove the river network. 3. litho-, morpho-, bioand pedo-stratigraphic characteristics the quaternary deposits have been subdivided into the late pleistocene porto vesme sinthem (pvm), comprising the cala mosca (pvm1; “tyrrhenian” auct.) and the portoscuso subsynthem (pvm2a), and the holocene sinthem. the pvm2a consists of gravelly alluvial fans, up to ca 10 m in thickness, that are truncated by marine cliffs and river incision. the top of the late pleistocene rio corongiu terraced alluvial fan, to the east of the poetto beach, is preserved for ca 10 km from the apical zone (205 m), to the rear of the coastline (m. 28). soil with well developed argillic horizons and with profiles a-bt-c, a-btc-c and a-btg-cg (typic, ultic e aquic paleoxeralf, apat, 2005) are locally preserved. the argillic horizons in places overlie carbonate-rich horizons but the latter develop also on top of the argillic horizons (a-bt-ck e a-btk-ckm, calcic and petrocalcic paleoxeralf). these are early holocene soils because their degree of weathering is not comparable with the last interglacial soils of the apennines (coltorti & pieruccini, 2005). the pvm1, crop out only at cala mosca (capo s.elia), that is the type locality of the “tyrrhenian”, the penultimate high standing marine stage (issel, 1914; spano, 1980; ulzega et alii, 1982) and at marina piccola (fig.1a). a few decimetres of gravels and bioclastic sands, including strombus bubonius, lay unconformably on a rocky marine platform whose elevation varies from ca + 1 m to + 4 m asl. they are sealed with over 7 m of debris and aeolian sands. at cala mosca, these sediments are also found inside a coastal cave with mussel boreholes up to 3.8 m asl. the holocene deposits that after the recommendations of geologists dealing with the marine areas, have been mapped as “tyrrhenian” in age, crop out at sa illetta and at foxi (fig. 2). at sa illetta sands and calcarenites constitute the remains of an inner beach ridge up to ca. 1,5 m asl while at foxi they crop out along the beach. molluscs are typical of coastal and lagoon environments. small colonies of cladocora coespitosa in living position are present in both sites. incised into the pleistocene terraced deposits, there is a holocene alluvial gravelly terrace locally containing polmonates and thin buried soil (a1c or a1ck profile). it is cut by a coastal cliff sealed with alluvial or beach deposits. nowadays, most rivers are bordered by artificial levees but in the past they had a braided pattern associated with a high solid load due to accelerated slope erosion. laterally, they interlayer with alluvial fan deposits. prior to this braided pattern, air-photos reveal that meanders occupied the plain. close to the coastline the riu corongiu create a small fan delta whilst the flumini mannu generated cuspidate deltas inside the s.gilla lagoon. in the quartu bay the rivers enter the molentargius swamp, originated by the is arenas beach ridge made with even laminated sands and gravels up to ca. 5 m asl,. organic lagoon mud has recently been dredged at a depth of 8 m. we recognised only present-day mollusc fauna but ulzega et alii (1982) mention the presence of strombus bubonius, although it is possible that it was reworked from older layers. stable or mobile sea-level, stable or mobile sardinia during the holocene: evidence from the cagliari gulf mauro coltorti 1, s. barca 2, e. melis 3 1 dipartimento di scienze della terra, via di laterina, 8 53100 siena –coltorti@unisi.it 2 dipartimento di scienze della terra, via trentino, 51 09100 cagliari 3 progemisa s.p.a via contivecchi, 7 cagliari 88 fi g. 1a s ke tc h m ap o f th e si nt he m s of t he c ag lia ri s he et ; 1 . l at e p le is to ce ne t er ra ce d a llu vi al f an ; 2 . h ol oc en e te rr ac ed a llu vi al p la in ; 3 . h ol oc en e al lu vi al d ep os its ; 4 . h ol oc en e b ea ch d ep osi ts ; 5 . l oc at io n of t he s ei sm ic p ro fil e of f ig .2 ; 6 . m ai n si te s in t he t ex t: 1 . s .l or en zo ; 2 . f ox i; 3. is a re na s; 4 .p ra n’ e s ill i; 5. s a m an na m at ta (n ot in t he m ap b ut r ep or te d in t he c lo se r ar ea o ve r th e sa m e un it) ; 6. s .m ic he le c em et er y; 7 . s a ill et ta ; 8. c al a m os ca ; 9. m ar in a p ic co la ; 10 . s ta gn o d i s im b iri zz i; 11 . s ed d a is a m m os tu s; 1 2, p ra ni ‘ e s ill i; 13 . p oe tt o; 1 4; a rc u m ai ni ; 15 , la p la ya ; 1 6. s an ta r ep ar at a: 1 7. c al a s p in os a; 1 8. c ap o s .m ar co ; 1 9; c ap o fr as ca ; 2 0 s .a nt io co ; 2 1. p or to v es m e; 2 2. m at za cc ar a; 2 3. c ix er ri b as in ; 2 4. s am as si ; b , s tr at ig ra p hi c re la tio ns hi p b et w ee n th e d iff er en t si nt he m s. 89 4. chronostratigraphic data a new u/th dating on cladocora found in cala mosca gave 122,11+5,3/-5,01 ka (em-216-6375) but the low isotopic 230th/232thratio suggests contamination. a date of 138 ± 8 ka was obtained by hearthy et alii (1986) but the sample had a percentage of calcite exceeding 9%. when calcite exceeds 5%, the 230th/234uratio or the 230th/238uratio ratio are not measured, samples have to be rejected (kauffmann, 1986). belluomini et alii (1986) utilising the isoleucine epimerization, report an age of over 250 ka. hearty et alii (1986) utilises the ratio between arca/glicimeris, because the results from a single species are unreliable. the last interglacial shells would have a ratio close to 1,31 but at cala mosca it varies between 1,37 (lower part) and 0,86 (top). however, this method is unreliable because the decaying ratio varies with the temperature (mccarroll, 2002; walker, 2005). the chronology of the pvm2a fluvial deposits is based on a date of 34.810 + 2880/-2120 bp (amskia24070) of organic material found 10 m below terraced alluvial fan gravels at samassi. the holocene terraced deposits have been dated at sa matta manna. polmonate shells found in silty layers in the lower part of the sequence gave 8.680 ± 60 bp (ams, beta150624). in the s.lorenzo area and at s.michele cemetery (fig.1a) rolled fragments of pottery testify that the incision occurred after the early neolithic. at foxi the whole rock dating of calcarenites gave 23.140 ± 90 bp (beta-138678) while a u/th of corals gave 53,3 +0,8/-0,7 ka (em-130-6376). at sa illetta, a sample of fig. 2 the seismic profile (a) located to the south of la playa beach ridge (fig.1) used by orrù et al. (2004) to establish an unconformity between holocene and tyrrhenian deposits (b). interlayering is evident in our interpretation (c). 90 shell was dated at 40.420 ± 1.120 bp (ams, beta138680) while the whole rock was 18.880 ± 50 bp (ams, beta-138675). ulzega & hearthy (1986) also obtained an unreliable u/th dating of cladocora of 149 ± 10 ka because stratigraphy, calcite content and isotopic ratios are unknown. at is arenas a sample of shells was dated at 26.740 ± 360 bp (ams, beta-138676). isoleucine epimerization allowed belluomini et alii (1986) and hearthy et alii (1986) to attribute the deposits to the neo-tyrrhenian. ulzega & hearthy (1986) report corals, never published in a comprehensive way, coming from the poetto and la playa beaches, dated respectively at 6,5 and 7 ka. holocene datings also come from marine shells found in the clay filling in front of the cagliari port (orrù et alii, 2004). 5. discussion and conclusions cala mosca and marina piccola constitute the older units cropping out below debris and aeolian deposits (fig.1b). terraced late pleistocene alluvial fans are the older deposits inland. their incision was filled with alluvial deposits later incised and filled with the actual fluvial sediments. the latter unit shows a transition to coastal deposits subdivided into a number of beach ridges and lagoon deposits similar to the adriatic (coltorti, 1997) and tyrrhenian coasts (boschian et al., 2006). the reliability of radiometric dates of organic matter and polmonates in late pleistocene and holocene alluvial deposits is confirmed by the rolled pottery. the dating of the shell remains at sa illetta, is arenas and foxi is evidently unreliable. these are holocene beach ridges lying at the base of marine and fluvial escarpments that affect the late pleistocene terraced deposits (fig.1b). aeolian deposits or paleosoils are absent. shells found in lagoon deposits at + 6 m asl at the vascone site (matzaccara, carbonia sheet) dated to 36.220 ± 730 b.p. (beta-138698) but at the same layer with a few pieces of rolled pottery confirm a systematic error for these holocene deposits. the older ages of the shells could be due to the hard water effect or diagenetic processes. also the marine deposits of santa reparata (fig.1a), attributed to last interglacial with isoleucine epimerization (ulzega & hearthy, 1986), are holocene in age. in fact, they overlie (and not underlie) aeolian deposits that in the nearby cala spinosa contain polmonate shells dated to 20.010 ± 60 bp (ams; beta 138687). the sa illetta and is arenas beach ridges were attributed to the “tyrrhenian” also because, following an eustatic model, a series of deep narrow valleys would have cut the “tyrrhenian” deposits during the last glaciation. however, a deposition dominated by climatic processes follows an eventual erosion as a consequence of sea level fall (plint et al., 1992) and seismic profiles demonstrated a strong sedimentation before 18 ka down to the shelf break (lecca et alii, 1998). in particular is arenas beach ridge completely dams the valley and if it is tyrrhenian in age, no later erosion and limited sedimentation occurred in the basin. the erosional valleys that in the model of pecorini (1986) and orrù et alii (2004) were carved during the cold period in our idea were modelled during the late glacial/early holocene, after the reduction of the solid load resulting from reforestation while the sea level was still low. this is confirmed by the holocene age of the valley filling and by the interlayering visible in our reinterpretation of the orrù’s seismic profile (fig. 2). barrier beaches are the result of long-shore drifting of river sediments after neolithic soil erosion. the high elevations of the sa illetta and is arenas coastal deposits was also used to support a “tyrrhenian age because holocene storm deposits are not expected above 4 m asl (issel, 1914; ulzega et alii, 1982). however, elevation must not aprioristically represent a proof. if elevation and not stratigraphy should be the criteria, new discoveries are impossible. stratigraphy suggests that the holocene sea-level rose higher than the present day and/or that some parts of sardinia are affected by positive tectonic movements. sardegna is considered a stable region but the geological setting and the faults cutting the late pleistocene deposits suggest otherwise. the “tyrrhenian” tidal notches in the orosei gulf (carobene & pasini (1973) also demonstrated differential uplift. moreover, if the dating of cladocora found at the sea level and dated ca 7 ka at la playa and poetto (ulzega & hearthy (1986) are reliable they confirm a higher sea level during the early holocene or tectonic movements. in fact, today cladocora grow between 4 and 10 m bsl. if the holocene sea level never exceeded the present day one (lambeck et alii, 2004) the cagliari area is affected by uplift. however, it is our opinion that the curve of the holocene sea level rise is still far from resolved. acknowledgements the work is the result of the carg project sheet 557, cagliari, legge 305/89, convenzione apat serv.geol.d’it. regione autonoma sardegna. we thank the progemisa for the continued logistic and technical support. references apat, (2005) note illustrative alla carta geologica alla scala 1:50.000 f.557 cagliari. selca ed., 240 pp. belluomini g., branca m., delitala l., pecorini g. & spano c., (1986) isoleucine epimerization dating of quaternary marine deposits in sardinia, italy. z.geomorph., suppl.bd.62, 109-117. boschian g., bossio a., dall’antonia b. & mazzanti e., (2006) il quaternario della toscana costiera. studi costieri, 12, 3-207. carobene l. & pasini g., (1973) contributo alla conoscenza del pleistocene superiore e dell’olocene del golfo di orosei (sardegna orientale) . boll.soc.adriatica di scienze, trieste, 64, 5-36. coltorti m., (1997) human impact in the holocene fluvial and coastal evolution of the marche region. central italy. catena, 30, 311-335. coltorti m. & pieruccini p., (2006) the last interglacial pedocomplexes in the lithoand morpho-stratigraphical framework of the centralnorthern apennines. quaternary international, 156-157, 118-132. hearthy p.j., (1986) an inventory of last interglacial age deposits from the mediterranean basin: a 91 study of isoleucine epimerisation and uranium series dating. z. geomorphologie, n.f., 62, 51-70. hearthy p.j., miller g.h., stearns c.e., & szabo b.j., (1986) aminostratigraphy of quaternary shorelines in the mediterranean basin. geol. soc. am. bull., 97, 850-858. issel a. (1914) lembi fossiliferi quaternari e recenti osservati nella sardegna meridionale dal prof. d. lovisato. rend. acc. naz. lincei, cl. sc. fis. mat. nat., 23, 759-770. lambeck k., antonioli f., purcell a. & silenzi s., (2004) sea level changes along the italian coast for the past 10,000 yr. quaternary science review, 23, 1567-1598. lecca l., panizza v. & pisano s., (1998) the sedimentary framework of cagliari basin: a pliopleistocene underfed rift basin in the southern sardinia margin. il quaternario, 11(2), 301-318. kauffman a., (1986) the distribution of 238th/234u ages in corals and the number of last interglacial high stands. quatern.res., 25, 55-62. muru m. (1983) presenza di pliocene inferiore nel sottosuolo di quartu sant'elena (cagliari). boll. soc. sarda sc. nat., 22, 93-98. mccarroll d, (2002) amino-acid geochronology and the british pleistocene: secure stratigraphical framework or a case of circular reasoning? journ. quat.sci., 17, 647-651. orrù p., antonioli f., lambeck k., verrubi v., lecca c., pintus c. & porcu a. (2004) holocene sea level change of the cagliari. quaternaria nova 8, 193212. pecorini g., (1986) considerazioni geomorfologiche intorno a s.igia, (stagno di s.gilla, cagliari). in s.igia, capitale giudicale. is st. medioevale, 15-20. plint a.g., eyles n., eyles c., walker r.g., (1992) control of sea level change. in walker r. & james n. eds., facies models: response to sea level change,15-25. pomesano cherchi a.,(1971) studio stratigrafico e micropaleontologico del pozzo oristano 1 (sardegna). memorie della società geologica italiana, 10, 1-16. ulzega a., ozer a., lecca f., leone g. pecorini c., spano c. & cordy m.j., (1982) excursion tableronde tyrrhenian de sardaigne. inqua, 88 pp. ulzega a. & hearthy p.j., (1986) geomorphology, stratigraphy and geochronology of late quaternary marine deposits in sardinia . z.geomorp., n.f.suppl. bd., 62, 119-129 walker m., (2005) quaternary dating methods, john wiley & sons, 187 pp. base landscape influence on the development of the medieval city-state of siena, italy armando costantini1 & i. peter martini2 1dipartimento di scienze della terra, università di siena, italy 2school of environmental sciences, university of guelph, guelph, on, n1g 2w1 canada corresponding author: i.p. martini <pmartini@uoguelph.ca> abstract: costantini a. & martini i.p., landscape influence on the development of the medieval city-state of siena, italy. (it issn 0394-3356, 2010) this paper examines how the landscape has influenced the development of the medieval–early renaissance city-state of siena, italy. siena is a hill-top town with a historic ~2 km2 wide core surrounded by ancient city walls. it still preserves the medieval urban plan and gothic architecture, and its inhabitants keep ancient traditions alive. it is built on pliocene, loosely cemented, calcareous, marine, porous sandstone that overlies impermeable marine calcareous silty clay. the town is limited on three sides by steep slopes indented by secondary deep, narrow, small valleys. the forth side to the north is a gently sloping terrain along the hilltop leading to distant highlands. this geomorphologic setting had been beneficial to the development of the town during mediaeval times because readily defendable and, being far from wet, unhealthy, malaria-infested lowlands, it was crossed by a major medieval pilgrimage route (via francigena) to rome. however the hilltop location presented difficulties such as scarce availability of water and limited space to expand. siena tried valiantly to adapt to the demand of expanding population and international markets. two major underground aqueducts were built for a total of about 25 km long tunnels, to bring water both to the centre of the walled town mainly for human consumption and to a major fountain (fonte) complex at the base of the hill that was the major medieval industrial site. however, water was never plentiful and became totally insufficient for the expanded mechanized industrialization of cloth-making that started in mid 14th century. siena could not compete with other towns, like the neighbouring florence, endowed with fluvial hydraulic power. like other hill-towns siena also had the problem of limited space for its growing population inside city walls. within the city the space was and still is maximized in two main ways. one is to level hilltops for constructions, such as the cathedral, or cut terraces into the easily quarried soft sandstone for buildings. the other is to build retaining walls in the upper parts of the secondary, indenting, narrow valleys and partially filing their apex, as it was done during the last century to obtain the stadium and associated athletic facilities, or, in the medieval times, to build the famous palazzo pubblico (town hall) and its antecedent, sloping semi-arcuate (pecten-shell like) public square. riassunto: costantini a.& martini i.p., influenza dell’ambiente sullo sviluppo della città medievale di siena, italia. (it issn 03943356, 2010) questo articolo esamina l’influenza che la geologia e la geomorfologia hanno avuto sullo sviluppo della città-stato medievale di siena. la città antica ha un’estensione di circa 2 km2 ed il suo centro storico si sviluppa sul culmine di tre colline. l’impronta medievale della città è segnalata dall’architettura gotica, dalla planimetria e dalle sue mura. la città è costruita su arenarie calcaree di età pliocenica, poco cementate, porose, deposte principalmente in ambiente litorale, che poggiano su argille marine calcaree ed impermeabili. le arenarie formano delle ripide scarpate (coste) che delimitano la città su tre lati. solo verso nord è presente un crinale piu’ dolce che raccorda la città in modo quasi pianeggiante con il resto del territorio. questa situazione morfologica ha avvantaggiato la città durante il medioevo rendendola praticamente inespugnabile. la posizione collinare di siena costituì, inoltre, un altro vantaggio proteggendola dalla malaria. quando i tratti delle antiche strade romane, che correvano lungo le coste tirreniche ed nelle valli appenniniche interne che divennero infestate dalla malaria perchè impaludate, divennero impraticabili, i pellegrini che viaggiavano verso roma e quelli che dalla città eterna si spostavano verso l’europa, scelsero il percorso (via francigena) piu’salubre che passava per siena. il grande incremento nel numero di pellegrini che sostavano a siena comportò aumento di ricchezza e di popolazione. dalla seconda metà del xiv secolo lo sviluppo della città fu però limitato dalla scarsità di acqua e di spazio disponibile per espandersi. l’aumento del fabbisogno idrico comportò l’escavazione di acquedotti sotterranei per un totale di circa 25 km. l’acqua ottenuta, tuttavia, non fu mai sufficiente per la città e l’industria tessile che stava crescendo, e dentro, la cinta muraria, non vi era spazio per allargare i complessi industriali. siena non poté quindi piu’ competere contro altre città, come firenze, che potevano avvalersi della forza idraulica dei loro fiumi per sviluppare l’industria. siena utilizzò al massimo lo spazio che aveva dentro le mura spianando le colline e le asperità del terreno o accumulando riporti per ubicarvi palazzi e costruzioni. ad interventi del genere si devono la realizzazione, nel medioevo, della piazza del campo, del palazzo pubblico e della piazza del mercato. in tempi moderni la costruzione dello stadio comunale, ubicato all’interno di una delle valli che si insinuano fino al centro della città. il continuo impegno per utilizzare al meglio le caratteristiche morfologiche ed idrogeologiche del proprio territorio sviluppò nei senesi fin dall’antichità, un uso parsimonioso e molteplice delle risorse naturali e dell’acqua in particolare (siena la città con poca acqua sviluppò una vera e propria “cultura dell’acqua”). i senesi, modificando solo in parte e senza deturparla la morfologia del luogo, riuscirono a costruire monumenti unici come il complesso del duomo, e la famosa piazza del campo, la cui forma di conchiglia e’ dovuta all’adattamento della piazza all’apice di una valle. keywords: medieval city-state, underground aqueducts, development with nature, landscape limitations for city development, pilgrimage routes, via francigena. parole chiave: città-stato medievale, acquedotti sotterranei, sviluppo compatibile con la natura, limitazioni ambientali per lo sviluppo urbano, pellegrinaggio, via francigena. il quaternario italian journal of quaternary sciences 23(2bis), 2010 volume speciale 283-298 284 a. costantini & i.p. martini 1. introduction geology and geomorphology affect human activities, and, conversely, humans often modify the environment to adapt it to their needs, differently in different time periods, (martini et al., 2010). the objective of this paper is to analyze relationships between the landscape features (such as geology, geomorphology, climate, and hydrology) and the human activities, and how these contributed to the development of the city-state of siena during the medieval to early-renaissance times. siena is located in the central-north part of italy, in the tuscan region, west of the northern apennines mountains (fig. 1). it is about 70 km from its perennial rival florence, 130 km from pisa/leghorn the main tyrrhenian harbour of the province, and 80 km from grosseto the main centre of the maremma that was one of the main granaries of ancient siena along the tyrrhenian sea. siena was built along a hillcrest. its historical centre is about 2 km2 wide. it is still surrounded by intact ancient city walls, and preserves much of the original medieval urban plan. the modern inhabitants maintain many of the ancient structures and traditions alive. one example is the subdivision of the city into 17 neighbourhoods (contrade). their ancient rivalries are still played out in bareback horse races (called palio) twice a year. 1.1. environmental conditions 1.1.1. geology siena is located at the nw margin of the siena-radicofani basin. this is one of the basins of tuscany that developed in nw–se directed tectonic depressions delimited by major thrust and normal faults (fig. 1) (martini & sagri, 1993; bonini & sani, 2002). the sw flank of the basin is composed of triassic–miocene metamorphic and sedimentary rocks, the ne flank of triassic–oligocene sedimentary rocks, mostly sandstones. the partial f i l l ing of the basins consists of pliocene offshore marine, calcareous, silty clays toward the centre with some intercalations of sandstones and conglomerates, and shallow marine sandstones, conglomerates and lagoonal silty deposits toward the margins. the sedimentary deposits underlying siena are characterized by marine silty clays at the base, overlain by a series (up to seven in places) of shallowing upward parasequences formed mainly by calcareous, fossiliferous, marine shoreface sandstones, coastal conglomerates, and some lagoonal deposits (fig. 2) (terzuoli, 1997; costantini & martini, 2004).the sandstones are poorly cemented (the cement constitutes 5 % in volume of the rock), but sufficiently strong to be a good substrate for buildings and for stability of steep slopes. the conglomerates occur as two major facies. one is characterized by clasts-supported, internally poorly stratified deposits of medium sorted, well rounded clasts up to 15 cm in diameter. they are interpreted as fluvial channel deposits. the other is characterised by clasts-supported, weakly internally stratified deposits with well sorted, well rounded, flat clasts up to 10 cm in diameter. these are interpreted as beach deposits. the substrate of siena is cut by several normal faults oriented nw–se and ne–sw. the faults are still active and they have been responsible for several earthquakes, most of low intensity (v–vi in the mercalli scale: less than 5 in the richter scale; castelli & bernardini, 2006). a series of these earthquakes that started on september 21 and terminated on december 29 of 1697 is famous because reported in the ancient town registers of siena (bicherna) (fusai, 1991). some destructive earthquakes did occur as well, such as those that occurred in 1792 and 1798 (fiorini, 1991). they damaged columns supporting the dome of the cathedral (duomo) (ca, fig. 3), toppled the upper part of the bell tower of the church of s. domenico (sd, fig. 3), other private towers, and damaged several habitations particularly in the area of fontebranda (fb, fig. 3). siena benefitted from various geological resources. among these, clays for ceramic products were obtained from the nearby basin floor (most of siena is built of bricks), carbonates from the hills bounding the basin were used for some early towers and several palaces, sandstone from the near apennines mountains fig. 1 generalized structural maps of the northern apennines. major structural features and neogene–quaternary basins of the northern apennines (si: siena town and siena-radicofani basin). (after pascucci et al., 2007). mappa strutturale schematica dell’appennino settentrionale. strutture principali e bacini neogenico-quaternari. (si: città di siena e bacino di siena-radicofani. (modificata da pascucci et al., 2007). 285landscape influence on the development of the ... fig. 2 schematic cross-section of the pliocene deposits under siena (1: marine silty clay; 2: sandstone; 3: basal argillaceous sandstone; 4: sandy conglomerate lenses; straight inclined line below the cathedral (duomo): normal fault; ca: duomo (cathedral); fb: fontebranda; fo: fortezza (fort); sd: s. domenico; vm: val di montone; see location of cross-section on figure 3). (after lazzarotto & pascucci, 1998). sezione schematica dei depositi pliocenici sui quali poggia siena (1: argille marine; 2: arenarie; 3: arenarie argillose basali; 4: lenti di conglomerati sabbiosi; linea inclinata sotto il duomo: faglia normale; fb: fontebranda). vedi traccia della sezione sulla figura 3. (modificata da lazzarotto & pascucci, 1998). fig. 3 map of siena showing the city walls and sites mentioned in the text. (a–b coss-section shown in figure 2; ca: duomo (cathedral); cm: camollia; cp: il campo (piazza); cv: castelvecchio; dp: due porte; fb: fontebranda; fg: fonte gaia; fl: fonte di follonica; fo: fortezza (fort) ; me: piazza del mercato; mi: viale g. minzoni; pm: pian dei mantelini; pn: ponte di romana; po: piazza della posta (matteotti square); pp: palazzo pubblico (town hall); ps: prato di s. agostino; pv: porta ovile; s: rastrello valley; sa: salicotto; sd: s. domenico; sf: s. francesco; sg: piazza s. giovanni; sm: porta s. marco; st: stadio comunale (soccer field); vf: via francigena; vi: viale dei mille; vm: val di montone; vp: vallepiatta street). mappa di siena che mostra la cinta muraria ed i siti discussi nel testo. ( a–b sezione mostrata in figura 2; ca: duomo (cathedral); cm: camollia; cp: il campo (piazza); cv: castelvecchio; dp: due porte; fb: fontebranda; fg: fonte gaia; fl: fonte di follonica; fo: fortezza (fort) ; me: piazza del mercato; mi: viale g. minzoni; pm: pian dei mantelini; pn: ponte di romana; po: piazza della posta (matteotti square); pp: palazzo pubblico (town hall); ps: prato di s. agostino; pv: porta ovile; s: valle del rastrello; sa: salicotto; sd: s. domenico; sf: s. francesco; sg: piazza s. giovanni; sm: porta s. marco; st: stadio comunale (soccer field); vf: via francigena; vi: viale dei mille; vm: val di montone; vp: via di vallepiatta). 286 were and are still used for street paving, and other ornamental rocks have been used such as marble, travertine, some limestone, and metamorphosed volcanic rocks (balestracci & piccinni, 1977). furthermore during the medieval times siena extracted ore, including silver for its coin, and iron, from the colline metallifere, a chain of low hills located to the sw of siena halfway to the tyrrhenian sea. 1.1.2. geomorphology siena is located on an elongated hill that protrudes southeastward into the siena basin from the chianti–cetona highlands (fig. 1). consequently the ancient town is bounded by very steep slopes on three sides indented diagonally by narrow deep secondary valleys, and a gently northwestward grading hillcrest. this imparts a characteristic birdfoot (reversed y) shape to the city-map (fig. 4). during the medieval and early renaissance times siena was not expugnable from three flanks. the fourth flank was protected by extra fortifications and double city door (antiporto). ancient siena, however, did not have a reliable sufficient supply of water. no permanent streams exist there. two small seasonal creeks are present near the base of the hill and some springs with limited output are present at the boundary between the sandstone aquifer and the underlying impermeable clays. therefore there never was sufficient water supply for the fast growing ancient city and its industries. 1.1.3. climate and agriculture siena has a typical warm mediterranean climate mitigated by moderate windy conditions. maximum temperatures are registered in july and august with a monthly average of 28oc together with the least monthly precipitation of 28 and 30 mm respectively. minimum temperatures are reached between december and february with monthly averages of 3oc to 4oc. maximum monthly average precipitation is reached in november with about 112 mm, and, except for the summer, the monthly average ranges between 60 to 90 mm. this means that during the summer the clayish countryside of the siena basin becomes dry and unproductive. during the spring and autumn, though, the precipitation is sufficient for a good production of cereals (mainly wheat) and grass. very good-quality oil and wine are produced from the surrounding hills. during medieval times siena could also obtain foodstuff from maremma that was a very fertile area, although vexed by lethal malaria. 2. landscape and humans: adaption and limitations the development of societies mostly depends on internal and external sociological, political and economic conditions, but, particularly in emerging entities, it is also greatly affected by the geology, morphology, climate and hydrology of the land; that is, the landscape. the landscape-influence differs from locality to locality, or in the same place from one time period to another as societies evolve and needs change. 2.1. siena pre-medieval times the peopling of siena in antiquity is not well documented. only a few pre-medieval archaeological sites have been found in some hills along the southwestern side of the basin (fiorini, 1991), a possible etruscan tomb has been documented near siena, and some tunnels near springs at the base of the hill have bell-shaped roofs typical of etruscan constructions. the roman occupation of the area is better documented, although siena probably remained a colony of secondary importance. there are several archaeological finding in siena among which a mosaic and a buried pavement that most likely was part of the floor of a street or a cistern. some documents report cavity habitations cut into the sandy substrate (locally called tufo) near the main square of siena (il campo: cp on fig. 3) where there were numerous taverns (tabernae). poorly preserved ruins of roman baths (terme) have been found near siena (bargagli petrucci, 1992). furthermore the colony is mentioned in roman maps as sena julia. the roman occupation has fomented the legend that siena was founded by the mythical sons (aschius and senius) of remus (remus was one the two founders of rome). like the father, they are beliefig. 4 schematic 1965 topographic map of siena with indication of the secondary narrow valleys that indent the main sienese hill. (a: s. ansano; f: fontebranda; g: gavina; n: fontenova; o: follonica; p: pescaia; s: rastrello; t: pispini; vm: montone). carta topogafica del 1965 della zona di siena che mostra le valli secondarie che risalgono fino al centro della città. (vm: montone; g: gavina; a: st ansano; f: fontebranda; s: rastrello; p: pescaia; n: fontenova; o: follonica; t: pispini). a. costantini & i.p. martini 287 ved to have been nursed by a female wolf. it is also said that a statue of venus was found near a spring. this suggests that romans managed the small local springs trying to increase the outflows. 2.2. siena during the medieval to early renaissance times siena is essentially a medieval city. it was one of the first independent city-states (comune), and reached its best period during the xii–first half of the xiv century. the city developed through the agglomeration of early villages/castles located in adjacent slightly higher lands in the siena area (catelvecchio (cv)– duomo:ca), castel montone (castel montorio–s. maria dei servi:ms) and castello del poggio malavolti (~camollia:cm) (fig. 3) (fiorini, 1991; libro dell’istrice, 2004). as the city enlarged, several new wider city walls were built, eventually enclosing most of the bottom-valley fountains (fonti) including those of fontebranda (fb) and follonica (fl), and several agricultural fields (locally called orti) useful during sieges (figs. 3, 5). as new walls were built, the remnants of the older ones became part of the cityscape and were incorporated in habitations. the city-walls were built differently according to the location: they were built at the top of steep, long slopes, such as at s. francesco (sf)–porta ovile (pv), viale don minzoni (vm), porta s. marco (sm) (fig. 3). they, instead, covered the side of smaller scarps and built slightly higher for defence, such as just east of the due porte (dp) along pian dei mantellini (pm). one common way to build the walls was a sacco. that is, two brick walls were raised close to each other and the space between them was filled with loose, pressed gravel (fig. 6). reinforced buttresses were constructed to reinforce the walls where they cross fault zones. fig. 5 maps showing the various city walls built at different times as the city was enlarging. (after bortolotti, 1988; department of archaeology of the university of siena). (a) early medieval age. (b) first half of 12th century. (c) beginning of 13th century. (d) solid line: half of 13th century, dashed line 15th century. mappe di siena che mostrano i vari stadi di costruzione della cinta muraria (da mappe schematiche del dipartimento di archeologia dell’università di siena). (modificate da bortolotti, 1988 e da mappe del dipartimento di archeologia dell’univeristá di siena). (a) etá medievale. (b) prima metà del xii secolo. (c) inizio del xiii secolo. (d) linea continua: metàl del xiii secolo, linea spezzata xv secolo). fig. 6 typical construction “a sacco” of the city walls of siena. costruzione tipica “a sacco” della cinta muraria di siena. landscape influence on the development of the ... 288 2.2.1. houses, palaces and towers many early habitations of siena were caves excavated in the relatively soft sandstone substrate, and wooden buildings. these were progressively substituted, especially staring in the second half of the 13th century, by houses built with wood and bricks (fig. 7). some palaces, towers and churches were made of stones, mainly limestone. the use of the substrate as integral part of habitations lasted through the medieval times as shown by the walls of a house composed of remnant natural strata of conglomerates still visible in piazza s. giovanni (sg, figs. 3, 8a). ornamental stones like marble and serpentinites (weathered ophiolites) were used for churches and some monuments. towers, originally made of stones and later of bricks, had the double function of status symbol (the higher the tower, the higher was the wealth and political status of the family) and defence (fig. 8b). later on, they were remodelled as habitations (case-torri). the use of bricks in siena became eventually predominant for every construction because the clay resource was readily available nearby at low cost (zdekauer, 1896/1980; bortolotti, 1988). during early stages, the furnaces to make bricks were located within the city. however they were a continuous fire risk for the surrounding wooden houses and were eventually moved into the countryside. as the population grew, the habitations were built closer to each other along narrow steep streets within the limited space enclosed by the city walls. it has been estimated that in the first decades of the 14th century siena reached a population of 50,000 people living in a 2 km2 area (bairock et al., 1988; ginatempo & sandri, 1990; pirillo, 1994). siena is primarily characterized by a gothic stile, modified in places by the development of the typical arco senese that is a cuspate high gothic arc enclosing a lower round arc (fig. 9). to preserve the medieval architectonic characteristics, recent restructuration (latest 1900s) of houses of entire neighbourhoods, such as the salicotto (sa, fig. 3), was made utilizing bricks in the same old fashion and similar architecture. 2.2.2. eco-sociologic conditions promoting the expansion of the citystate the city-state of siena reached its golden developmental period toward the end of the 13th and the beginning of the 14th century under the governo dei nove (government of the nine: 1287–1355) when major buildings such as the palazzo pubblico (pp: town hall, fig. 3) were completed, and some ambitious constructions were initiated but never completed, such a huge cathedral of which only an unfinished facade and some columns remain. the development of the city-state was greatly influenced by the via (route) francigena (vf) used by pilgrims travelling from various parts of europe toward rome (fig. 10). this was a route over the hills, which was preferred to the older roman roads that crossed the coastal plains of the tyrrhenian sea (via fig. 7 modern view of the fontebranda street climbing toward the medieval houses of the city centre constructed with bricks. in the background the tower of the town hall (called torre del mangia). fotografia recente della strada di fontebranda che sale verso le case medievali del centro cittadino costruite in mattoni. la torre comunale del mangia si intravvede all’orizzonte. a. costantini & i.p. martini aurelia) and inland valleys, such as the val di chiana (via cassia), infested by malaria. siena catered well to pilgrims in several ways. it offered accommodation, health care, and, importantly, protection from profiteering hosts within the city and, within its territory, from the numerous brigands that preyed on the travellers along the route. it also offered money change (siena at that time had its silver coin) and banking facilities so that the people could leave in safekeeping part of what they owned before adventuring toward the dangerous roman area. the pilgrims brought wealth to the city directly and also by being good ambassadors when they returned to their states. siena at that time was one of the most important traders in the european markets, particularly for wool cloth, and its banks served popes, cardinals and princes. 2.2.3. geo-sociologic conditions hampering development and capability to compete environmental constraints, continuous competition and fighting internally and against the neighbouring rival florence, unwise political and economic decisions, and the terrible tragedy of the pestilence bouts of the 14th century starting with the one of 1348 that reduced the population by 2/3 (to less than 20,000 people), weakened tremendously the city (bowski, 1964, http://www.jstor.org/stable/2850126?seq=1; pinto, 2002). siena was not capable to rebound after the pestilence, adapt to the new world’s conditions, and compete with 289 fig. 8 views of siena. (a) lower part of the battistero and stairs leading up to the cathedral square. note conglomerate layer (arrow) enclosed in the wall of the houses to the left. (b ) ancient tower built with stones.). viste di siena. (a) parte basale del battistero e scalinata che porta in alto a piazza del duomo. nota lo strato di conglomerato (freccia) che è stato incluso nel muro di una casa. (b ) antica torre costruita in pietra. landscape influence on the development of the ... larger cities, like florence, that, instead, experienced strong and fast demographic, economic and political development. the fortunes of siena progressively decreased and the city-state was eventually defeated in 1555 by a spanish-florentine army, and became part of the granducato di toscana of the medici of florence in 1557. a sienese republican government resisted in a nearby fortified small town until 1559 (http://en.wikipedia.org/wiki/siena). low supply of water and insufficient accommodation space were two of the most important landscape features that limited the development of the city-state of siena in the medieval and early-renaissance times although that society tried valiantly to adapt and modify the existent conditions to its advantage. 2.2.3.1. water in medieval siena the water supply from local bottom-valley springs was sufficient for the few early habitants of siena, but as the city enlarged, more water was needed particularly starting in the 1100s. the output of the local springs was augmented by opening the contact between the aquitard and aquifuge layers enlarging local tunnels. as the demand for water increased further, two large underground aqueducts – bottino maestro di fontebranda (fb) and that of fonte gaia (fg) – were built, the latter between 1334 and 1466 (balestracci et al., 1983; balestracci, 1984/85, 1993; kucher, 2005). these aqueducts consist of 25 km long tunnels (fig. 11a). it was possible to readily excavate the tunnels with hand-tools of the time because the calcareous sandstone of the substrate is relatively soft, and naturally maintains vertical walls (fig. 11b). only locally, particularly where fault zones were crossed, brick reinforcing walls were needed. occasionally along 290 fig. 9 gothic architecture in siena: detail view of the santa maria della scala museum fronting the cathedral square. this is a large building used as hospice for medieval pilgrims and as hospital until the last century. note the typical arco senese above the now sealed doors (arrows). architettura gotica senese: dettaglio della facciata del complesso museale di santa maria della scala (ex ospedale). questo grosso edificio ha ospitato un ospedale per pellegrini nel medioevo ed ha svolto le funzioni di ospedale civile fino al 1980. oggi è diventato il principale complesso museale senese. nota il tipo arco senese sulle porte murate basali (frecce). fig. 10 via francigena: major medieval pilgrim route through north-central italy toward rome. the map shows slight variations along the via francigena as wells as the ancient roman roads (via aurelia and via cassia) that crossed malaria-infested lowlands. (after fletcher 2000/2008). via francigena: una strada di pellegrinagio importante attraverso l’italia verso roma. la mappa mostra i vari percorsi e la loro posizione rispetto alle antiche strade romane (via aurelia e via cassia) che attraversavano aree pianeggianti che nel tempo si impaludarono e furono infestate dalla malaria. (modificata da fletcher 2000/2008). a. costantini & i.p. martini the route, harder concretions were encountered, and the tunnels were slightly modified from the standard size of 0.80 m in width and 1.80 m in height. the tunnels were excavated primarily by experienced miners that had worked in the mineral mines of the colline metallifere. to accelerate constructions of the bottino mestro di fonte gaia two crews were used, one working from the aqueduct-end in the main town square (piazza del campo) backward and the other from just outside the city walls toward the centre. some levelling errors were made and they are still recorded by the modifications made to the tunnels (higher and/or wider) at the points of encounter of the two crews (costantini & martini, 2004). the two underground aqueducts get water from various small springs on the nearby northwestern higher lands. these springs have developed at the contact between coastal calcareous argillaceous sandstone layers and silty, clayish lagoonal deposits of the margins of the siena basin (costantini & martini, 2004). one of the aqueducts (bottino mestro di fontebranda) carries the waters to the base of the siena hill were there also is the original larger spring of the area (fig. 11a). the other aqueduct (bottino maestro di fonte gaia) carries the water to the centre of town in the main square, in front of the palazzo pubblico and to other parts of the walled town (fig. 11a; see http://www.italyguides.it/us/siena_italy/piazza_del_campo/fonte_gaia.ht m for interactive detailed view and 360o moving panoramic about these and other sienese localities). originally the aqueducts supplied water only to public fountains (fonti). later, starting in the 1500s, secondary tunnels were built under the city to carry water from the bottino maestro di fonte gaia to wells under palaces and religious buildings. these were not the first underground aqueducts constructed in antiquity in the world. similar underground canals were built mainly for irrigation in china (karezes, ii sec. bc), in the middle east (qanats; 1st millennium bc; kucher, 2005), in north africa (the ancient fogarras) and, of course, the numerous roman aqueducts. however the construction of the aqueduct of siena was a great engineering feat for the times because of the hydraulic innovations implemented. with rudimentary tools the miners succeeded in maintaining a regular slope of 2‰ of the tunnel floors for the water to flow properly. under the city they devised simple strategies, such as locally meandering the small canal (gorello on fig. 11b) carrying the water within the tunnel, to slow and thus deepen the flow and go from the main aqueduct to secondary ones through small holes in a small barrier used to measure the amount of water to be paid by the users. also large decantation pool (fig. 11c ) were built in 1338 near the entrance of the town to settle silt that had entered the system during particularly heavy precipitations, and also to allow for calcite to precipitate from the very hard waters before they were distributed to the public fountains and private wells. public fountains (fonti) were built at the end of the main aqueducts and in front of local tunnels dug to enlarge the outflow from springs at the base of the siena hill. they were built for maximum use of the scanty water resource. some fonti were monumental, such as the fonte gaia in piazza del campo (pc) (figs. 3, 12), but they too were used, for a time, for public needs, such as washing interiors of animals sold in the market held in the main city square. others, like fontebranda (built first in 1198 and rebuilt in 1246), were complex establishments (fig. 13). they consisted of a series of buildings and pools. the first pool was invariably for water for human consumption. in some fonti this was followed by a pool to raise fish, responding to religious diets of the time. in most others, the first pool was followed by others for animals to drink and be washed, then others for washing clothes; the waters were then canalized to run small mills, and finally to irr igate field outside the city walls. the fontebranda complex had some of the pure water from the aqueduct also deviated into additional pools/cisterns to wash wool and manufacture wool cloth, and other water was used in the processing of slaughtered animals. so siena, the city that always suffered from a limited amount of water instituted a ‘culture of water’ fostering conservation and maximum multiuse. nevertheless water was never enough for the enlarging city and for the industry of cloth to satisfy the burgeoning european markets especially from the mid 14th century on. nowadays the ancient underground aqueducts have been partly restructured and water is used mainly for irrigating city gardens. it cannot be used for human consumption because the source area is not protected against potential contaminations and the tunnels are not kept free of calcium carbonate incrustations and pollutants as they were during medieval times. potable water is now obtained for siena through modern aqueducts from the distant volcanic hills of mt. amiata located to the south (fig. 1) and from deep wells dug near the centre of the basin. 2.2.3.2. building space within the medieval walled town the overall original morphology of the siena hill has been little changed throughout the ages, but some local areas within the city have been modified by either removing or adding rocks and sediments to generate flat surfaces to build edifices, squares, roads, or to develop cultivable fields inside the city walls. there are several notable cases where considerable material has been removed from hilltops. one is the removal of about 5 m of sandstone down to a resistant conglomerate layer to build the cathedral (duomo) and the adjacent square (building started in 1226). much more recently, in the first part of the 1900s, the small hill called malavolti was levelled down to build the matteotti square (also called “piazza della posta” (po, fig. 3). several metres of sandstone were removed as shown by the remnant high at the sw corner above which there is the church of the contrada del drago. terraces for construction of edifices have been and are still cut on the flanks of the hill. notable is the cut on the northern side of the hills of the cathedral made in 1317 to build the battistero (christening church) and its small adjacent square of (piazza s. giovanni: sg, fig. 3). of interest is the conglomerate that forms a wall of a house facing such a piazza. this conglomerate is the same that underlies the higher square of the cathedral, except that it has been downfaulted 4.5 m below it (fig. 8a). this fault was active in the past and created problems during the botched construction of 291landscape influence on the development of the ... 292 fig. 11 medieval aqueducts (bottini) of siena. (a) map of the main (maestro) bottini as well as local shorter ones, and the various shapes of the tunnels. (b) typical tunnel of the bottini showing brick layered floor with a central small canal (gorello). in his case, under the city, the gorello is forced to meander to reduce the slopeand deepen the flow to allow water to exit toward private tunnels and wells. (c) large settling tanks built at the northern end of town for settling impurities and crystallization of calcite from hard waters. (from balestracci d., 2004). aquedotti medievali (bottini) di siena. (a) mappa dei bottini mestri e secondari, e schemi delle varie forme dei cunicoli. (b) cunicolo tipico dei bottini pavimentato con mattoni e con un canaletto centrale (gorello). in questo caso il gorello è meandriforme per poter ridurre la pendenza, aumentare la profondita’ del flusso ed invitare l’acqua ad andare verso i pozzi degli utenti. (c) vasche di decantazione costruite all’entrata nord di siena per far sedimentare l’eventuale materiale in sospensione ed abbassare il tenore in calcio delle acque calcaree dei bottini. (da balestracci d., 2004). a. costantini & i.p. martini c the larger cathedral that was planned in the early 1300s, and has also played an import role in the strong late-1700s earthquakes that damaged many buildings and towers (fiorini, 1991; castelli & bernardini, 2006). levelling of terrains was also achieved by dumping material on certain areas. a large artificial plateau is the prato di s. agostino (ps, fig. 3) was formed by dumping on it the material removed to construct the cathedral and its square. of even greater impact is the modification made to construct both viale dei mille (vi) between the church of s. domenico (sd) and the fortezza (fort, built in 1560 by the medici of florence; fo), and the famous sloping, shell-shaped square of the campo (cp, fig. 3). (a) the viale dei mille (vi) and associate football (soccer) field (st) required a causeway to be built across the relatively narrow but deep secondary rastrello valley (s, figs. 3, 4, 14), and partial filling and levelling of the upper part of the valley. the start was the dumping of rubble generated by the destruction of buildings, including the toppled upper part of the bell tower of s. domenico (sd), by the series of earthquakes of the late 1700s. the construction of the actual causeway was done starting toward the end of 1800s (fig. 14a, b). part of the upper valley was filled and levelled, and viale dei mille–football field complex was completed as it is today in mid 1930s (fiorini, 1991). (b) an earlier impressive modification of another secondary valley-head (val di montone:vm, figs. 3, 4, 15) led to the development of the complex of piazza del mercato (me)-palazzo pubblico-piazza del campo (cp) (figs. 3, 15). first a low retaining wall was build across the valley to reduce erosion, and, adding material, a terrace was constructed sufficiently large for piazza del mercato (me, fig. 3). a second retaining wall was later built in 1194 where the palazzo pubblico is now (the initial town hall was built in stages from 1284 to about 1310). the remaining upper part of the valley-head was rather irregular and in part dissected by rill erosion. several modifications were made along the roads running along the hillcrest to divert rainwater away from the square onto the opposite flank toward fontebranda. later, the surface of the valley-head was smoothed out and finally in the early 1300s it was paved with bricks as it is today (http://en.wikipedia.org/wiki/ piazza_del_campo). the semi-arcuate pecten-shell shape of this most famous square thus reflects the smoothed out valley-head. 2.2.3.3. roads like other medieval cities built on hills, siena had, and still has, some difficulty in building good roads, except for the one running along the crest of the hill. this is the route locally followed by the via francigena as well. except for that, the other roads of siena were originally narrow, winding, steep, and dark within the city, being bordered by constructions with protruding upper floors. as the city grew, modifications were made mainly straightening and enlarging the roads and forcing removal of protruding constructions. except for the principal ones, they remained unpaved until recent centuries. secondary roads of siena are still today rather narrows, very steep straight downhill, difficult to be used by modern transport. this has benefited the town helping in preserving its ancient character. the use of private cars is banded from most of the walled city. to satisfy modern people (local inhabitants and tourists) needs, parking facilities have been built either underground in a few places just inside the city walls, or at the foot of the hill. for the people to reach the 293 fig. 12 partial view of the monumental fonte gaia in the piazza del campo at the centre of town. visione parziale di fonte gaia (monumentale) in piazza del campo al centro di siena. landscape influence on the development of the ... 294 fig. 13 fontebranda complex. (a) narrow valley enclosed by medieval walls. the fonte is at the base of the cliff below the church of s. domenico. (b) main building of the fonte with water for human consumption. (c) complex of fontebranda showing arched building containing the main pool for potable water, and, sequentially to the left: drinking pool for animals, pool for washing clothes, pool for washing animals, and farther to the left and outside the walls, water was used for running mills, and finally to water the fields. parallel to this, pools/cisterns (not visible in this figure) were used for washing wools, washing and tanning pelts, for butchering and so on. note gardens on top of the main arched building. in previous times this top was used as tiratorio; that is, an area where to stretch and dry coloured wool-cloth. (from costantini & martini, 2004). complesso di fontebranda. (a) valle stretta di fontebranda. la fonte è alla base della rupe di s. domenico. (b) edificio pricipale della fonte con la vasca di acqua potabile per usi umani. (c) schema generale che mostra il parsimonioso utilizzo in cascata dell’acqua della fonte. l’edifico con archi è quello principale con acqua potabile. l’acqua in esubero della prima vasca passava alla seconda che serviva per abbeverare gli animali, poi alle vasche per lavare i panni ed infine nel guazzatoio che serviva per far rinfrescare e lavare gli animali. l’acqua veniva poi incanalata fuori le mura per far ruotare le macine di sei mulini ed infine per irrigare i campi. altre vasche, non visibili qui, venivano riempite di acqua pulita ed utlizzate per lavare la lana ed il panno (principale industria medievale) e, fino a circa trenta anni fa, per macellare gli animali. notare i giardini nel tetto dell’edificio principale della fonte. in tempi piu’ antichi questo tetto veniva usato come tiratoio, cioe’ dove si poteva stendere il panno di lana ad asciugarsi. (da costantini & martini, 2004). a. costantini & i.p. martini ancient town on top of the hill, impressive movable stair facilities have been built, partly excavated along the hill flanks and hidden such that they are essentially invisible at the surface and do not deturpate the landscape. 3. discussion – a resilient society considering the interaction between space and water availability and changing societal needs through time, some interesting experiences have occurred in siena. one is very recent (last decade) and relates to the building of a parking lot at the foot of the hill near fontebranda. in doing so a large area was exposed at the contact between the impermeable marine clay and the overlying porous sand. the consequence was a relatively large flow of water, and remedies had to be implemented to protect the parking construction. one may say that finally the sieneses had found the mythic underground stream, the “diana”, that they were unsuccessfully seeking since medieval times and for which they were derided by dante in the divine comedy. actually it is not a stream they found, they just opened a spring a bit wider and nowadays a small permanent rivulet flows from under the parking lot. another interesting adaptation during medieval times was dictated by the interaction between the need for defence, lack of water, and viability within the city. to start with, siena had no water to fill the moat of the city walls, particularly along the vulnerable, flatter part of the hillcrest. so they filled parts of the moat with bundles of wood (fascine) to burn in case of attach (fiorini, 1991). these fire-moats were called carbonaie (places where coal was generated or stored), for obvious reasons (fiorini, 1991). holmes were cultivated along the moats as source of wood. once new walls were built the older carbonaie were abandoned. at first they were leased for cultivation and eventually they were levelled off and new city roads were built on them. several roads of modern siena have this origin, such as part of viale don minzoni (mi), pian dei mantellini (pm) and possibly via di vallepiatta (vp) (piatta: flat in italian, but most likely derived from latin platea: large, wide; so via vallepiatta may indicate the road of the wide valley; fiorini, 1991) (fig. 3). furthermore some topo-names still indicate the former existence of moats outside the older, abandoned city walls. one of such names is a locality called “ponte” (pn, fig. 3) inside modern siena, which refers to a bridge that crossed the moat (now a levelled city road) in front of an ancient city-door (a partially preserved arc still marks the of ancient door of porta s. maurizio) (lusini, 1921). siena is just one of the many medieval hilltop citystates that had to cope with the limitations offered by the landscape as their population grew and globalization increased during the difficult, dangerous medieval–early renaissance times. siena like other towns of the region, such as pisa and lucca, flourished during early times but eventually had to surrender to the more powerful, better energy-endowed, rival florence crossed by a relatively large river (arno river). through time, the sienese society reacted to the limitations given by the landscape through maximization and conservation of available resources. after many centuries these early limitations to growth eventually turned out to be beneficial because ancient structures and even the overall urban plan has been preserved and nowadays they are great cultural and touristic assets. 295 fig. 14 maps showing the progressive enclosure of the apex of a small secondary valley (rastrello valley: s) indenting the main sienese hill, and construction of a causeway and of the modern athletic complex (stadio). note that the first map has opposite orientation to the other two. (small arrow indicate the trend of the future causeway). (a) detail of 1595 map by vanni showing the head-valley part of the deep narrow rastrello valley (s) between s. domenico (sd) and the fortezza (fo), crossed by the city walls (cv). (b) 1860 map showing the same site (different orientation) with an incipient pile of refuses from the disruption of several towers and edifices by the late 1790s earthquakes, protruding (arrow) from s. domenico into the rastrello valley, upslope from the city walls. (c) 1965 topomap showing completed causeway between s. domenico e the fortezza with the road (viale dei mille:vi) and the athletic complex (stadio: st, fig. 3) on the partially filled and levelled head-valley part. mappe che mostrano la progressiva chiusura della valle secondaria del rastrello (s), e la costruzione di un terrapieno sul quale è stato realizzato il complesso sportivo (stadio comunale). nota che l’orientazione della prima mappa a sinistra è diversa dalle altre due. (a) dettaglio della mappa del vanni (1595) che mostra la cima non modificata della valle del rastrello fra s. domenico (sd) e la fortezza (fo), attraversata da un muro di cinta cittadino (cv). (b) mappa del 1860 che mostra un inizio di terrapieno che protrude (freccia) nella valle da s. domenico. questo terrapieno iniziale era formato dalle macerie causate dal terremoto del 1798. (c) carta topografica del 1965 che mostra il terrapieno completato con sopra il viale dei mille (vi) fra s. domenico e la fortezza, e parte dell’impianto sportivo (stadio) a no del viale (st, fig. 3). landscape influence on the development of the ... 4. conclusions (a) the overall medieval–early renaissance development of siena can be synthesized into three main periods. a first period (10th –11th centuries) was characterized by a rapid growth, followed by a second period of great wealth during the 12th –13th centuries, up to the apex of its maximum development at the end of the 13th century and first part of the 14th century under the government of the nine. it is during this last period that major monuments of siena were built. amborgio lorenzetti in his fresco in the palazzo pubblico (1338/1339) left us a glimpse of siena and its society of that period. then followed a period of decadence starting in 1348 after the first bout of the black death, when some major projects, such as the new cathedral, had to be abandoned, and siena became uncompetitive in the european market. siena lost its city-state independence to spain and florence in 1555/1557. (b) landscape conditions that favoured the early 296 fig. 15 piazza del campo area. (a) map showing modified headvalley part of the montone valley (vm) and constructions of the mercato square (me), town hall (pp), and the pectenshell shaped main square (piazza del campo: cp). (b) partial view of piazza del campo and of the town hall with its typical belltower. zona di piazza del campo. (a) mappa che mostra l’apice modificato della valle di montone (vm), piazza del mercato (me), palazzo pubblico (pp), e la piazza del campo (cp) a forma di conchiglia che segue l’andamento della la testata della valle. (b) vista parziale di piazza del campo ed il palazzo pubblico con la torre del mangia. a. costantini & i.p. martini development of siena included an easily defensible location on the crest of a steep hill, and the development of a pilgrimage route (via francigena) from central europe to rome, which followed the hills rather than the older lowland tracks that had become infested by deadly malaria. the pilgrims were well treated by siena and brought great wealth to the city, directly by visiting it, and indirectly as good ambassadors to their countries thus opening favourable markets throughout europe. (c) adverse landscape conditions that contributed to the eventual loss of competitiveness of siena in the enlarging european markets were the lack of sufficient water (no streams or large springs occur in the area) and space (on a relatively steep hill indented by small, narrow, deep secondary valleys) for further developing the city and the industry of cloth making. (d) the society of siena valiantly struggled to overcome the adversities by implementing regimes of conservation and multiuse of the available resources. long (25 km total) underground aqueducts (the bottini) were constructed, and the limited amount of water they carried was wisely used, and the city flourished. . (e) the advent of the back death, starting in 1348, brought siena to its knees as about 2/3 of the population died. siena could not revitalize afterwards and could not compete with larger, more resilient cities like florence that was endowed by hydropower from its river allowing it to develop an increasingly more efficient, stronger, and therefore more competitive industry. in addition to economics, political mistakes, and internal family feuds it may have endured, logistic limitations significantly contributed to siena inability to successfully compete in the more industrialized world of the 1500–1600s centuries. 5. acknowledgements we are grateful for the helpful comments to the reviewers, m. sagri, f. sani and v. pascucci. thanks are given to the university of siena for supporting this research and to the natural science and engineering research council of canada (nserc) for a research grants. 6. references bairoch p., batou j. & chevre p. (1988) la population des villes européennes de 800 à 1850: banque de données et analyse sommaire des résultats. droz, genève. 336 pp. balestracci d., lamberini d. & civai m. (1983) i bottini medievali di siena. cassa rurale ed artigiana di sociville, comune di siena. 219 pp. balestracci d. (1984/85) i bottini, acquedotti medievali senesi. gielle, siena. 38 pp. balestracci d. (1993) i bottini medievali di siena. alsaba, siena. 158 pp. balestracci d. & piccinni g. (1977) siena nel trecento. assetto urbano e strutture edilizie. ed. cluef, firenze. 201 pp. bargagli petrucci f. (1992) (first edition 1906) le fonti di siena e i loro acquedotti . edizioni periccioli, siena. vol 1, 356 pp.; vol 2, documenti (some in latin). bonini m. & sani f. (2002) extension and compression in the northern apennines (italy) hinterland: evidence from the late miocene-pliocene sienaradicofani basin and relations with basement structures. tectonics, 21, doi:10.1029/2001tc900024 bortolotti l. (1988) siena. editori g. laterza & figli spa, roma-bari. 246 pp. bowsky w.m. (1964) the impact of the black death upon the sienese government and society . speculum, 39, 1–34 [and in part available in http://www.jstor.org/stable/2850126?seq=1]. castelli v. & bernardini f. (2006) unearthing earthquakes in the sienese crete: how we improved the seismic catalogue of a low-seismicity area. first european conference on earthquake engineering and seismology (a joint event of the 13th ecee & 30th general assembly of the esc), geneva, switzerland, 3-8 september 2006, paper number: 837.[available also in http://www.earthprints.org/bitstream/2122/2565/1/1190.pdf]. costantini a. & martini i.p. (2004) siena (central italy): urban geology of a medioeval hilltop town and its bottini (underground aqueduct) and monumental fountains guidebook for field trip d01 of the 32nd international geological congress. apat– italian agency for the enviromental protection and technical services, rome. 16 pp. (http://www.apat.gov.it/site/it-it/apat/fieldtrip guidebooks/during-congress_field_trips/). department of archaeology of the university of siena (accessed on january, 2009) urban expansion, siena. http://www.paesaggimedievali.it/luoghi/ siena/si18h.html fiorini a. (1991) siena. immagini, testimonianze e miti nei toponimi della città. edizioni alsaba, siena. 406 pp. fletcher a. (2000-2008; accessed on january, 2009) http://www.paradoxplace.com/perspectives/map s/via%20francigena.htm fusai l. (1991) la storia di siena dalle origini al 1559. il leccio. 434 pp ginatempo m. & sandri l. (1990) l’italia delle città: il popolamento urbano tra medioevo e rinascimento (secoli xiiixvi). le lettere: florence, italy kucher m.p. (2005) the water supply system of siena, italy. routledge, new york & london. 225 pp. (check also short summaries in the website: http://faculty.washington.edu/kucher/diana/english/bottini.htm). lazzarotto a. & pascucci v. (1998) aspetti geologici e geomorfologici del territorio senese. in: boldrini m. (ed.), le terre di siena. la storia, l'arte e la cultura di una provincia unica. protagon editori toscani, siena, 151–188. lusini v. (1921) note storiche sulla topografia di siena nel secolo xiii. in: lusini, v. (ed.), dante e siena. tip. lazzeri, siena, 11–92. martini i.p. & sagri m. (1993) tectono-sedimentary characteristic of late miocene-quaternary extensional basin of northern appennines. earth science reviews, 34, 197–233. 297landscape influence on the development of the ... martini i.p., sarti g., pallecchi p. & costantini a. (2010) landscape influences on the development of the medieval–early renaissance city-states of pisa, florence, and siena, italy. in: martini i.p., chesworth w. (eds.), landscapes and societies – selected cases, springer, dordrecht, 203–222. pascucci v., martini i. p., sagri m& sandrelli f. (2007) effects of the transverse structural lineaments on neogene–quaternary basins of tuscany (inner northern apennines, italy). in: nichols g., paola c. & williams e.a. (eds.), sedimentary processes, environments and basins – a tribute to peter friend. ias, special pubblication, 37, 155–183. pinto g. (2002) campagne e paesaggi toscani del medioevo. nardini, firenze, 237 pp. pirillo p. (1994) demografia, città e territori: alcuni esempi toscani ed umbri tra la fine del xii secolo ed i primi del xiv. in: comba r. & naso i. (eds.) demografia e società nell’italia medievale, società per gli studi storici, archeologici ed artistici della provincia di cuneo, cuneo, 293–311. terzuoli a. (1997) sedimentologia, ichnologia e stratigrafi a di alta risoluzione in ambienti marini marginali: a) le sabbie conglomeratiche costiere del bacino di siena (italia), b) i depositi d’estuario del bacino dell’alberta (canada). tesi di dottorato, universita’ di siena. zdekauer l. (1896; reprinted 1980) la vita privata dei senesi nel dugento. arnaldo forni editore, bologna. 228 pp. 298 ms. ricevuto il 21 maggio 2010 testo definitivo ricevuto il 14 ottobre 2010 ms. received: may 21, 2010 final text received: october 14, 2010 a. costantini & i.p. martini dinamica recente ed attuale degli alvei fluviali in italia: stato dell'arte e prospettive nicola surian1 & massimo rinaldi2 1dipartimento di geografia, università di padova, via del santo 26, 35123 padova 2dipartimento di ingegneria civile e ambientale, università di firenze, via s. marta 3, 50139 firenze e-mail: nicola.surian@unipd.it riassunto: surian & rinaldi, dinamica recente ed attuale degli alvei fluviali in italia: stato dell'arte e prospettive. (it issn 0394-3356, 2008). lo scopo del presente lavoro è quello di fare il punto sulle ricerche che riguardano le variazioni morfologiche degli alvei in italia, evidenziando anche gli aspetti cruciali su cui le ricerche dovrebbero concentrarsi nell'immediato futuro. il lavoro si basa su di un'analisi bibliografica di settanta pubblicazioni e sulle ricerche condotte nell'ambito di un progetto nazionale (prin 2005). considerando la distribuzione temporale delle pubblicazioni riguardanti le variazioni morfologiche degli alvei in italia si può notare un aumento del numero di pubblicazioni nel corso del periodo in esame (1963 2007), ma comunque un numero relativamente basso di pubblicazioni per anno. dal punto di vista metodologico si osserva un prevalente approccio qualitativo fino alla fine degli anni '90, quindi l'impiego di approcci più quantitativi, in particolare per la ricostruzione della variazione temporale di parametri come la larghezza dell'alveo o la quota del fondo. la maggior parte dei fiumi italiani è stata interessata da simili variazioni per quanto riguarda la sequenza temporale, mentre l'intensità delle variazioni è dipesa da vari fattori, come, ad esempio, la morfologia originale dell'alveo. inizialmente si è verificata una fase d'incisione e restringimento, iniziata verso la fine del xix sec. e particolarmente intensa fra gli anni '50 e gli anni '80-'90 del xx sec. quindi, negli ultimi 15-20 anni, processi di allargamento dell'alveo sono stati osservati nella maggior parte dei casi. queste modificazioni morfologiche sono imputabili principalmente ad una serie di interventi antropici, quali il prelievo di sedimenti, la costruzione delle dighe, interventi di canalizzazione e variazioni di uso del suolo. un significativo miglioramento nella comprensione della dinamica degli alvei è derivato dalle ricerche più recenti, soprattutto attraverso la ricostruzione delle variazioni temporali della larghezza dell'alveo e più specifiche analisi sulle cause delle variazioni, ma vari aspetti richiedono ad oggi delle indagini più approfondite. un punto cruciale è rappresentato dalle variazioni altimetriche, sia nel medio che nel breve termine. per le variazioni nel medio termine, in mancanza di adeguati rilievi topografici, è determinante ricorrere a specifici rilievi geomorfologici dell'alveo, mentre per le variazioni più recenti è auspicabile l'impiego di tecniche quali gps, lidar e fotogrammetria digitale. infine si sottolinea l'importanza di trasferire le conoscenze acquisite con queste ricerche nella gestione e riqualificazione degli alvei. abstract: surian & rinaldi, present and recent dynamics of river channels in italy: state of the art and perspectives. (it issn 03943356, 2008). during the last centuries, and particularly in the second half of the 20th century, many fluvial systems have been significantly affected by human interventions (e.g. dams, sediment mining and channelization). such interventions have effects on flows, sediment regime and channel morphology, causing channel adjustments that are generally much larger than those that could be expected from natural channel evolution. for instance, most italian rivers have experienced considerable channel adjustments in the last decades, e.g. channel incision up to 10 m or more and channel narrowing up to 85-90 %. the aim of this work is to review the present state of knowledge on channel adjustments in italian rivers and to analyse research needs and perspectives. the work is based on a review of published studies (seventy papers have been collected and analysed) and on the research carried out within a national project (prin 2005) over the last two years. the first studies on channel adjustments in italian rivers date back to the beginning of the 1960s. considering the distribution of publications from such a period to the present (2007), an increase can be observed in the number of publications through time, however the number of publications remains quite low in each year (the highest value, 7 papers, was reached in 1994). concerning the methodologies used in these studies, a qualitative approach was dominant up to the end of the 1990s, then a more quantitative approach. the latter has implied, for instance, the reconstruction of temporal trends for channel parameters such as channel width and bed elevation. most italian rivers have experienced almost the same processes as for temporal trends, though the magnitude of adjustments varies according to several factors (e.g. initial channel morphology). initially, river channels underwent a long phase of narrowing and incision, which started in the late 19th century and was very intense after the 1950s. then, during the last 15-20 years, channel widening has become the dominant process in several cases. such channel changes have been induced mainly by a range of human interventions, specifically sediment mining, dam construction, channelization works and land use changes (e.g. reforestation). a significant advance in the understanding of channel adjustments was obtained recently as for the reconstruction of evolutionary trends (in particular trends of channel width) and causes of channel adjustments, but several issues will require more efforts in the future. one crucial point will be, for instance, the analysis of past and present bed level adjustments. reconstruction of past trends, in the absence or scarcity of topographic surveys, will need specific geomorphological field surveys, whereas the analysis of present trends should be supported by recent topographic technologies, such as gps, lidar and digital photogrammetry. last, but not least, there should be an increasing transfer and application of the results to river management. in fact, it is becoming more and more established among fluvial scientists and practitioners that knowledge of channel evolution in the medium-short term is a key ingredient for the sustainable management of fluvial systems. parole chiave: alvei fluviali, variazioni morfologiche degli alvei, impatto antropico. keywords: alluvial channels, channel adjustments, human impact. il quaternario italian journal of quaternary sciences 21(1b), 2008 233-240 234 n. surian & m. rinaldi 1. introduzione nel corso degli ultimi secoli, ed in particolar modo negli ultimi 50-60 anni, la morfologia e la dinamica della maggior parte dei fiumi italiani hanno subito delle profonde modificazioni, soprattutto a causa di vari interventi antropici (ad esempio costruzione di dighe, prelievo di sedimenti dagli alvei, interventi di canalizzazione, variazioni di uso del suolo). tali interventi hanno infatti modificato il regime dei deflussi e delle portate solide, oltre ad altri aspetti, come la mobilità laterale, fondamentali nella dinamica di un alveo fluviale. l'entità delle variazioni subite dagli alvei è stata considerevole, in quanto in molti casi ha comportato una vera e propria trasformazione morfologica, ossia una modificazione della configurazione planimetrica (ad esempio da un alveo a canali intrecciati ad un alveo di tipo “wandering” o, addirittura, a canale singolo). i processi più diffusi sono stati il restringimento e l'incisione dell'alveo. la larghezza dell'alveo ha subito generalmente una riduzione superiore al 50 %, fino a valori dell' 85-90 %, mentre l'abbassamento del fondo è stato dell'ordine di alcuni metri ma, localmente, anche di 10-12 m (surian & ri n a l d i, 2003; su r i a n et al., 2008a). generalmente queste modificazioni si sono realizzate nel corso di pochi decenni. simili variazioni morfologiche dell'alveo si sono verificate anche in corsi d'acqua di altri paesi europei ed extra-europei, ma raramente l'intensità dei processi è stata così elevata come nei corsi d'acqua italiani (wi l l i a m s , 1978; wi l l i a m s & wo l m a n, 1984; si m o n, 1989; xu ji o n g x i n, 1997; se a r & ar c h e r, 1998; winterbottom, 2000; liebault & piegay, 2001; lu et al., 2007). infatti se non sono rari fenomeni di restringimento come quelli osservati nei fiumi italiani, sono poco frequenti fenomeni di incisione dell'ordine di 10-12 m. le ricerche condotte in ambito nazionale ed internazionale sulle variazioni morfologiche degli alvei hanno lo scopo di quantificare queste variazioni, ma soprattutto di comprenderne i processi e le cause. alcuni aspetti cruciali in queste ricerche sono: a) la ricostruzione temporale delle modificazioni, che implica non solo una valutazione quantitativa della modificazione morfologica, ma anche una valutazione dell'evoluzione temporale del processo; b) l'individuazione delle cause, ossia una dettagliata analisi delle possibili cause, naturali ed antropiche, e dei loro effetti sulle portate liquide, sulla portata solida e sulla morfologia dell'alveo; c) l'analisi delle relazioni spazio-temporali fra cause e variazioni morfologiche. un ulteriore obiettivo della ricerca deve essere quello di fare delle previsioni sull'evoluzione futura di un alveo fluviale instabile. tali previsioni, che si basano sulla conoscenza della dinamica fluviale nel breve e medio periodo, sono infatti fondamentali per la gestione e riqualificazione di un corso d'acqua (do w n s & gregory, 2004; rinaldi, 2006; habersack & piegay, 2008). lo scopo del presente lavoro è quello di fare il punto sulle ricerche che riguardano le variazioni morfologiche degli alvei in italia, evidenziando anche gli aspetti cruciali su cui le ricerche dovrebbero concentrarsi nell'immediato futuro. le considerazioni esposte di seguito si basano sull'analisi bibliografica di settanta pubblicazioni e sulle ricerche condotte nell'ambito di un progetto nazionale (prin 2005 “dinamica recente ed attuale di alvei fluviali in italia centro-settentrionale: tendenze evolutive, cause ed implicazioni applicative”) conclusosi recentemente (gennaio 2008). il lavoro prende spunto da una precedente sintesi sull'argomento (surian & rinaldi, 2003), alla quale si rimanda per alcuni approfondimenti, e vuole pertanto mettere in evidenza anche i progressi di questi ultimi anni. 2. stato dell'arte: la ricerca in italia sulle variazioni morfologiche degli alvei le seguenti considerazioni derivano dall'analisi dei lavori esistenti sull'argomento. sono state reperite e consultate 70 pubblicazioni che comprendono un intervallo di oltre 40 anni (1963-2007). l'elenco completo delle pubblicazioni consultate è riportato in bibliografia. la distribuzione temporale di queste pubblicazioni mostra come, a partire dagli '60 del secolo scorso (si veda ad esempio ro v e r i, 1965; pe l l e g r i n i & ro s s i, 1967) fino ad oggi, ci sia stato un crescente numero di ricerche (fig. 1). negli anni '60 e '70 le pubblicazioni sono state molto limitate, rispettivamente 4 e 5, quindi 11 negli anni '80, 33 negli anni '90 e 17 nel periodo 2000-2007. nonostante l'incremento di pubblicazioni registrato negli ultimi 15-20 anni, il numero complessivo di pubblicazioni nell'intero periodo indica che si tratta di un tema di ricerca che ha suscitato un certo interesse, senza però raggiungere un vera e propria affermazione e collocazione in ambito nazionale. l'analisi bibliografica consente anche alcune considerazioni sui gruppi di ricerca (o i singoli ricercatori) coinvolti e sulla tipologia dei progetti nei quali si inseriscono le indagini sulle variazioni morfologiche degli alvei. alcune sedi universitarie (camerino, firenze, modena, padova, parma, pavia, perugia) ed il cnrfig.1 distribuzione temporale delle pubblicazioni riguardanti le variazioni morfologiche degli alvei in italia. temporal distribution of the publications regarding channel adjustments in italian rivers. irpi di torino risultano aver affrontato queste ricerche con una certa continuità temporale. per quanto riguarda la tipologia di progetti, la maggior parte delle pubblicazioni sono il risultato di singole iniziative ad eccezione del le ricerche che confluivano nel progetto finalizzato “conservazione del suolo” (sottoprogetto “dinamica fluviale”) (pellegrini et al., 1979b; castiglioni & pe l l e g r i n i, 1981a; 1981b), finanziato dal cnr, e di quelle connesse al progetto nazionale sopra citato (prin 2005), del quale cominciano ora ad essere pubblicati i primi risultati (surian & cisotto, 2007; pellegrini et al., 2008; ri n a l d i et al., 2008; su r i a n et al, 2008a; 2008b). da un punto di vista metodologico le ricerche si sono basate fondamentalmente su osservazioni in campo, analisi di cartografia storica, di fotografie aeree e di rilievi topografici. il cambiamento più significativo, percepibile solo nei lavori più recenti (ad esempio rinaldi et al., 2005), è stato probabilmente l'impiego dei gis che consentono un'analisi della cartografia storica e delle fotografie aeree molto più accurata e certamente più aggiornabile nel tempo. come già evidenziato in un precedente lavoro di sintesi (su r i a n & ri n a l d i, 2003), complessivamente le ricerche sono state poco quantitative, mancando ad esempio, nella maggior parte dei casi, ricostruzioni temporali delle variazioni morfologiche. ciò che emerse nel lavoro appena citato era la quasi totale assenza di ricostruzioni della variazione temporale di parametri come la larghezza dell'alveo o la quota del fondo e, pertanto, la definizione di precise relazioni fra le variazioni morfologiche e le relative cause. alcuni recenti lavori di sintesi, nei quali sono stati analizzati i dati relativi a più corsi d'acqua, hanno messo in evidenza la presenza di modificazioni morfologiche e processi molto simili nei fiumi italiani (rinaldi, 2003; su r i a n & ri n a l d i, 2003; 2004; su r i a n, 2006). le variazioni che accomunano gli alvei fluviali sono un restringimento (in alcuni casi anche dell' 85-90 %) ed un abbassamento del fondo (in alcuni casi oltre i 10 m) molto marcati. tali processi si sono manifestati in alcuni corsi d'acqua a partire dal xix secolo, ma sono stati molto intensi per un periodo relativamente breve, ossia tra gli anni '50 e gli anni '80-'90 del secolo scorso. le cause di variazioni così intense nella morfologia degli alvei sono state individuate nel prelievo di sedimenti dagli alvei, generalmente il fattore più rilevante, nella costruzione di dighe, in vari interventi di canalizzazione, in variazioni di uso del suolo a scala di bacino (in particolare l'aumento della copertura boschiva) e nelle sistemazioni idraulico-forestali. mentre la fase principale di aggiustamento, che ha comportato il restringimento e l'incisione degli alvei, è stata documentata in tutti i lavori, la successiva fase, cominciata generalmente alla fine degli anni '80 o nei primi anni '90, è stata individuata ed analizzata solo nelle ultime ricerche (su r i a n & ri n a l d i, 2004; ri n a l d i e t a l., 2005; su r i a n, 2006; ri n a l d i & si m o n c i n i, 2006; su r i a n & ci s o t t o, 2007). questa fase più recente (ultimi 15-20 anni) è stata caratterizzata in molti corsi d'acqua da un riallargamento dell'alveo e da stabilità del fondo o da aggradazione. tali processi non hanno comunque “compensato” le variazioni indotte dalla fase preced e n t e . 235dinamica recente ed attuale ... 3. ricerche recenti e prospettive future come accennato in precedenza, si è ultimamente concluso un progetto nazionale incentrato sulle variazioni morfologiche degli alvei in italia (prin 2005 “dinamica recente ed attuale di alvei fluviali in italia centro-settentrionale: tendenze evolutive, cause ed implicazioni applicative”). il progetto, che ha coinvolto tre sedi universitarie (firenze, padova e pavia) ed il cnr-irpi di torino, si poneva i seguenti obiettivi: 1. revisione delle metodologie comunemente impiegate per l'analisi delle variazioni morfologiche degli alvei fluviali. alla luce degli studi realizzati sui fiumi italiani, è infatti auspicabile definire quali parametri morfologici utilizzare e come questi debbano essere misurati, in modo tale da rendere omogenei i dati provenienti da differenti casi di studio. 2. in riferimento al punto precedente, messa a punto di una metodologia di rilevamento sul terreno che consenta, soprattutto in assenza di dati altimetrici, di valutare le tendenze evolutive nel breve e medio termine. 3. disponibilità di un maggior numero di casi di studio ben documentati rispetto a quelli esistenti (surian & rinaldi, 2003; 2004), ossia di casi di studio per i quali si disponga delle variazioni temporali di alcuni parametri morfologici dell'alveo, quali quota del fondo, larghezza, ecc. 4. monitoraggio e analisi della dinamica recente (ultimi 15-20 anni) ed in atto negli alvei fluviali. 5. affinamento e sviluppo degli schemi/modelli evolutivi recentemente proposti da su r i a n & ri n a l d i ( 2 0 0 3 ; 2004), al fine di definire un modello concettuale in grado di descrivere le tendenze evolutive dei fiumi italiani. 6. individuazione delle cause, antropiche o naturali, che hanno determinato le variazioni morfologiche degli alvei e dei rapporti temporali di causa-effetto. 7. previsione, seppure qualitativa, dell'evoluzione futura degli alvei fluviali; ciò sulla base sia delle tendenze evolutive passate ed in atto, sia di differenti scenari di gestione delle risorse (in particolare dei sedimenti e di uso del suolo) e di cambiamenti climatici. 8. valutazione delle ricadute applicative della dinamica fluviale recente ed in atto; in particolare i riflessi sulla gestione dei corsi d'acqua (manutenzione degli alvei) e sui possibili interventi di riqualificazione fluviale. sulla base dei lavori finora pubblicati o in corso di pubblicazione (ri n a l d i & si m o n c i n i, 2006; su r i a n & ci s o t t o, 2007; pe l l e g r i n i et al., 2008; ri n a l d i et al. , 2008; rinaldi, 2008; surian et al., 2008a; 2008b) si ritiene che per alcuni degli aspetti appena elencati c'è stato un sostanziale avanzamento nelle conoscenze, mentre per altri il contributo del progetto è stato più limitato. riguardo agli aspetti metodologici sono stati fatti progressi su vari fronti (analisi storica da cartografia, foto aeree e immagini satellitari, analisi dei rilievi topografici, rilevamento geomorfologico in campo). ad esempio si è posta molta attenzione nella valutazione degli errori associati alla stima dei vari parametri (ad esempio larghezza dell'alveo, grado d'intrecciamento, quota del fondo), e si è giunti alla definizione di procedure che debbono essere non solo accurate ma anche riproducibili. novità importanti sono state introdotte anche per il rilevamento geomorfologico in campo, in quanto sono state definite una serie di misure ed osservazioni finalizzate alla definizione delle tendenze evolutive di un alveo. questi aspetti relativi al rilevamento geomorfologico e all'utilizzo di apposite schede, sono illustrati in un articolo contenuto in questo volume (rinaldi, 2008). da parte dei ricercatori coinvolti nel progetto prin 2005 è prevista comunque una pubblicazione complessiva che riassuma tutti questi aspetti metodologici, in modo tale da fornire delle “linee guida” per lo studio delle variazioni morfologiche degli alvei. il numero di casi di studio affrontati nel progetto amplia in modo significativo le conoscenze pregresse sulla dinamica recente ed attuale degli alvei (si veda in proposito pe l l e g r i n i et al., 2008; ri n a l d i et al. 2008; su r i a n et al. 2008a; 2008b). per alcune caratteristiche degli alvei, in particolar modo per la larghezza, si dispone infatti di accurate ricostruzioni temporali, mentre rimangono più problematiche le ricostruzioni delle variazioni altimetriche per vari corsi d'acqua. ad esempio per quanto riguarda le variazioni di larghezza, non solo è ben documentata la fase principale di restringimento generalmente verificatasi tra gli anni '50 e gli anni '80-'90 del xx sec., ma anche le variazioni avvenute nel xix sec., nella prima metà del xx sec., e quelle più recenti. per gli ultimi 15-20 anni, come già anticipato, si è riscontrata in vari casi una tendenza all'allargamento dell'alveo, anche se non mancano tratti fluviali che continuano in un processo di restringimento (surian et al., 2008a). anche sui fattori che hanno indotto l'instabilità degli alvei il grado delle conoscenze è progredito in modo significativo, sia attraverso l'acquisizione di maggiori informazioni sugli interventi antropici in alveo e a scala di bacino, che attraverso analisi delle serie idrologiche (precipitazioni e portate). le conoscenze acquisite nel corso del progetto permetteranno quindi di affinare i modelli evolutivi attualmente esistenti (surian & rinaldi, 2003; 2004). sulla base del contesto nazionale ed internazionale della ricerca (a questo ultimo si è fatto cenno nel capitolo introduttivo, ma si veda anche ja m e s & ma r c u s, 2006; br a s i n g t o n & ri c h a r d s, 2007; ha b e rsack et al., 2008) gli aspetti sui quali dovrebbe mirare la ricerca nei prossimi anni sono, a nostro avviso, quelli qui di seguito elencati. 1. tendenze evolutive in atto. considerando che la fase principale di aggiustamento, ossia l'intenso restringimento ed incisione verificatisi generalmente fino agli anni '80-'90 del xx sec., è ormai generalmente esaurita, ed anche abbastanza bene documentata, è importante concentrare l'attenzione sull'ultima fase di aggiustamento in atto da alcuni anni. le variazioni più recenti, molto probabilmente indotte da una forte riduzione dell'attività di prelievo di sedimenti in alveo, sono state analoghe in vari casi (allargamento e sedimentazione) ma è plausibile aspettarsi dinamiche d'alveo differenti in relazione anche ad altre condizioni esistenti a scala di bacino e lungo i corsi d'acqua stessi (ad esempio la presenza o meno di dighe), nonché alla sequenza ed intensità degli eventi di piena. 2. l'impiego del telerilevamento e di tecniche quali lidar e gps. per la ricostruzione delle tendenze evolutive più recenti e per il monitoraggio della dinamica in atto gli strumenti più idonei appaiono le fotografie aeree a grande scala, tecniche topografiche quali lidar, gps e fotogrammetria, oltre al rilevamento geomorfologico in campo (per quest'ultimo aspetto si rimanda al punto successivo). mentre l'impiego delle fotografie aeree è consolidato e consente un'accurata quantificazione delle caratteristiche planimetriche dell'alveo, lidar, gps e fotogrammetria sono state impiegate nello studio della dinamica fluviale solo recentemente (la n e et al., 2003; hi c k s e t al., 2008; lollino et al., 2008; rumsby, et al., 2008), ma hanno notevoli potenzialità. la possibilità di acquisire modelli digitali del terreno (dem), non trascurando i problemi associati alla presenza di aree emerse e sommerse, rappresenta senz'altro un grande salto di qualità nella valutazione dei processi di erosione/sedimentazione in alveo, ma anche per la costruzione di bilanci di sedimenti (fu l l e r et al. , 2003; br a s i n g t o n et al., 2003) e quindi per una migliore comprensione dei processi in atto. 3. il rilevamento geomorfologico dell'alveo. il rilevamento sul terreno, con l'impiego di schede specifiche (rinaldi, 2008), è un aspetto cruciale soprattutto per la valutazione delle variazioni altimetriche. il metodo è essenziale per la ricostruzione delle variazioni passate, infatti raramente si dispone di una documentazione completa di rilievi topografici, ma anche per la valutazione delle tendenze attuali. riguardo quest'ultimo aspetto, il rilevamento geomorfologico può affiancarsi ai rilievi topografici (ad esempio gps e lidar) oppure sostituirsi completamente a questi quando non sussistano le condizioni per poterli realizzare. 4. i modelli e la previsione dell'evoluzione futura degli alvei. le conoscenze acquisite sull'evoluzione passata ed in atto degli alvei fluviali e sulle relative cause consentiranno di mettere a punto dei modelli che dovranno essere impiegati per prevedere l'evoluzione futura degli alvei. un primo passo sarà la messa a punto di modelli concettuali di evoluzione degli alvei, in grado di descrivere, seppure in termini di tendenza e quindi non quantitativi, la dinamica degli alvei italiani. tali modelli andrebbero quindi supportati da una quantificazione delle principali variabili che possono avere influenza sulla dinamica fluviale (ad esempio pendenza del fondo, dimensioni granulometriche, ecc.), in modo da individuare risposte morfologiche diverse al variare di tali parametri. oltre ai modelli concettuali, sarà importante l'utilizzo di modelli matematici, almeno per casi rappresentativi, per consentire una migliore comprensione dei rapporti tra cause ed effetti e per simulare possibili scenari di evoluzione. ad esempio i modelli cellulari, recentemente piuttosto diffusi nell'ambito della geomorfologia fluviale (nicholas et al., 2006; coulthard et al., 2007) potrebbero essere adatti a morfologie fluviali complesse (b r a i d e d o transizionali) come quelle presenti in molti corsi d'acqua italiani. in ogni caso le previsioni dovranno tener conto di possibili scenari di impatto antropico e di condizioni climatiche. 5. applicazione delle conoscenze alla gestione e riqualificazione dei corsi d'acqua. nell'ottica di una gestione sostenibile dei corsi d'acqua e tenendo come ri fer imento i contenuti del la direttiva quadro 2000/60, è evidente l'importanza di trasferire le conoscenze acquisite con queste ricerche nella 236 n. surian & m. rinaldi gestione e riqualificazione degli alvei. da una parte è importante che la gestione/riqualificazione si basi sulle tendenze evolutive dei corsi d'acqua (si veda ad esempio do w n s & gr e g o r y, 2004), dall'altra è essenziale che la gestione dei sedimenti assuma un ruolo più rilevante nei corsi d'acqua italiani considerando che l'alterazione nel regime del trasporto solido è stata una causa fondamentale delle modificazioni recenti ed in atto negli alvei fluviali. una gestione efficace e sostenibile dei sedimenti può realizzarsi anche attraverso l'adozione di nuovi approcci, come la definizione di una fascia di mobilità fluviale (piegay et al., 2005; ri n a l d i, 2006; ha b e r s a c k & pi e g a y, 2008). 4. conclusioni la presente analisi della ricerca sulla dinamica recente ed attuale degli alvei fluviali in italia suggerisce le seguenti considerazioni conclusive. 1. la dinamica recente ed attuale degli alvei ha destato l'interesse di un certo numero di ricercatori sin a partire dagli anni '60 del secolo scorso, in relazione al fatto che gli alvei italiani hanno subito delle notevoli modificazioni morfologiche con rilevanti implicazioni da un punto di vista applicativo. 2. nel corso degli anni si è giunti ad una buona conoscenza delle variazioni morfologiche che hanno interessato gli alvei italiani e delle relative cause, anche grazie ad approcci sempre più quantitativi. 3. i recenti sviluppi della ricerca suggeriscono che in futuro si dovrebbe puntare sull'impiego di tecniche quali gps, lidar, e fotogrammetria digitale per il monitoraggio, sulla modellazione (da quella concettuale a quella numerica), ma anche sul rilevamento geomorfologico dell'alveo che, per quanto problematico, e talvolta non risolutivo, deve comunque mantenere un ruolo di riferimento. infine la ricerca dovrà trovare sempre maggiore applicazione nell'ambito della gestione e della riqualificazione dei corsi d'acqua. ringraziamenti ricerca realizzata nell'ambito del progetto prin 2005 “dinamica recente ed attuale di alvei fluviali in italia centro-settentrionale: tendenze evolutive, cause ed implicazioni applicative” (coordinatore nazionale: n. surian). si ringraziano luisa pellegrini e ornella turitto per i loro commenti e suggerimenti che hanno permesso di migliorare la stesura definitiva di questo articolo. bibliografia adamoli l. & bertini t. (1993) evoluzione geomorfologica recente e processi erosivi in atto nell'alveo del f. vomano proceedings of the 4° geological day, l'impatto degli interventi antropici sulla dinamica fluviale e possibilità di recupero ambientale, ordine regionale dei geologi del l'abruzzo, sigea. ag n e l l i a., bi l l i p., ca n u t i p. & ri n a l d i m. (1998) dinamica evolutiva recente dell'alveo del fiume arno monografia cnr-gndci, pubblicazione n° 1739, pacini editore, pisa, 191 pp. aquater (1982) regione abruzzo. studio generale per la difesa della costa: prima fase rapporto interno, s. lorenzo in campo. ar i n g o l i d., bi s c i c., fa r a b o l l i n i p., fa z z i n i m., ge n t i l i b., materazzi m. & pambianchi g. (2003) recent observations on erosional processes in the potenza and chienti river alluvial plains (central marche, italy) in: castaldini d., gentili b., materazzi m. & pambianchi g. (eds.), geomorphological sensitivity and system response, viii italian romanian workshop on geomorphology, camerinomodena, 4-9 july 2003, pp. 21-34. aucelli p.p.c. & rosskopf c. (2000) last century valley floor modifications of the trigno river (southern italy): a preliminary report geografia fisica e dinamica quaternaria, 23, pp. 105-115. becchi i. & paris e. (1989) il corso dell'arno e la sua evoluzione storica. acqua aria, 6, pp. 645-652. bezoari g., braga g., gervasoni s., larcan e. & paoletti a. (1984) effetto dell'estrazione di inerti sull'evoluzione del l'alveo del fiume trebbia 2° convegno di idraulica padana, parma, 15-16 giugno 1984, pp. 165-182. bi g g i e r o v., fi o r e n t i n o m. & pi a n e s e d. (1994) evoluzione d'alveo del fiume volturno xxiv convegno di idraulica e costruzioni idrauliche, vol. ii, t4-233 t4-246. bi g g i e r o v., ca r g n e l u t t i m., fi o r e n t i n o m. & ol e s e n k.w. (1996) indagini sperimentali sull'evoluzione dell'alveo del volturno proceedings of the xxv convegno di idraulica e costruzioni idrauliche, vol. ii, pp. 158-169. billi p., chiaverini i. & ostuni d. (1994) studi preliminari su degradazione fisica e stabilità dell'alveo del f. cecina il quaternario, 7(1), pp. 311-316. bi l l i p. & ri n a l d i m. (1997) human impact on sediment yield and channel dynamics in the arno river basin (central italy) in: wa l l i n g d.e. & probst j.l. (eds.), human impact on erosion and sedimentation, proceedings of rabat symposium, iahs publications no. 245, pp. 301-311. bisci c., dramis f. & gentili b. (1992) recent and present geomorphological evolution of river beds and mouths in central-southern marche (italy) geooko plus, 3, pp. 83-96. bondesan m., with a contribution by castaldini d. (2001) h y d r o g r a p h y. in: ca s t i g l i o n i g.b. & pe l l e g r i n i g.b. (eds.), illustrative notes of the geomorphological map of po plain (italy), suppl. geogr. fis. dinam. quat., iv, pp. 33-44. br a g a g. & ge r v a s o n i s. (1989) evolution of the po river: an example of the application of historic m a p s in: pe t t s g.e., mo l l e r h. & ro u x a . l . (eds.), historical change of large alluvial rivers: western europe, wiley, pp. 113-126. br a s i n g t o n j. & ri c h a r d s k. (2007) r e d u c e d c o mplexity, physically-based geomorphological modelling for catchment and river management geomorphology, 90, pp. 171-177. br a s i n g t o n j., la n g h a m j. & ru m s b y b. (2003) methodological sensitivity of morphometric estimates of coarse fluvial sediment transport 237dinamica recente ed attuale ... geomorphology, 53, pp. 299-316. brunelli m. & farabollini p. (2005) fenomeni di erosione e dinamica fluviale in alcuni fiumi delle marche centro-meridionali in: br u n e l l i m. & farabollini p. (a cura di), dinamica fluviale, ordine dei geologi delle marche, tipoli tografia c. bellabarba, pp. 31-63. canuti p., cencetti c., conversini p., rinaldi m. & tacconi p. (1992) dinamica fluviale recente di alcuni tratti dei fiumi arno e tevere proceedings of the conference “fenomeni di erosione e alluvionamenti degli alvei fluviali”, univ. of ancona, 14-15 october 1991, pp. 21-35. canuti p., cencetti c., rinaldi m. & tacconi p. (1994) the fluvial dynamics of the arno river. 2. historical evolution of the arno river bed mem. soc. geol. it., 48, pp. 851-864. capelli g., mazza r., raffi r., agostini s. & di benedetto a. (1998) rischio di piena e dinamica fluviale nella piana di castel di sangro (appennino centrale abruzzo) mem. soc. geol. it., 53, pp. 585607. capelli g., miccadei e. & raffi r. (1997) fluvial dynamics in the castel di sangro plain: morphological changes and human impact from 1875 to 1992 catena, 30, pp. 295-309. castaldini d. & piacente s. (1995) channel changes on the po river, mantova province, northern italy in: hickin e.j. (ed.), river geomorphology, wiley, pp. 193-207. ca s t a l d i n i d., pi a c e n t e s. & ma l m u s i s. (1999) evoluzione del f. secchia in pianura nel xix e nel xx secolo (province di reggio emilia, modena e mantova, italia settentrionale) in: or o m b e l l i g . (ed.), studi geografici e geologici in onore di severino belloni, glauco brigati, genova, pp. 169-187. castiglioni g.b. & pellegrini g.b. (1981a) two maps on the dynamics of a river bed erosion and sediment transport measurement, proceedings of the iahs symposium, florence, 22-26 june 1981, pp. 223-228. ca s t i g l i o n i g.b. & pe l l e g r i n i g.b. (1981b) g e o m o rfologia dell'alveo del brenta nella pianura tra bassano e padova in: zunica m. (ed.), il territorio della brenta, amm. prov. di padova università di padova, pp. 12-32. cencetti c., conversini p., martani c. & nejad massoum m. (1992) considerazioni sulla dinamica fluviale del f. tevere nel tratto tosco-umbro compreso tra l' invaso di montedogl io e s. lucia proceedings i convegno nazionale dei giovani ricercatori in geologia applicata, pp. 527-536. ce n c e t t i c., du r a n t i a., fr e d d u z z i a. & ma r c h e s i n i i . (2004) narrowing and bed incision of a cobble bed river in central italy geophysical research abstracts, vol. 6. co c c o e., de ma g i s t r i s m.a. & de pi p p o t. (1978) studi sulle cause dell'arretramento della costa lucano-ionica: 1-l'estrazione degli inerti lungo le aste fluviali mem. soc. geol. it., 19, pp. 421-428. co l t o r t i m., na n n i t. & vi v a l d a p. (1991) la bassa valle del fiume musone (marche): geomorfologia e fattori antropici nell'evoluzione della pianura alluvion a l e geogr. fis. e dinam. quat., 1 4, pp. 101-111. conti a., di eusebio l., dramis f. & gentili b. (1983) evoluzione geomorfologica recente e processi in atto nell'alveo del tenna (marche meridionali) proceedings xxiii congr. geogr. it., catania, vol. ii, iii, pp. 53-66. coulthard t.j., hicks d.m. & van de wiel m.j. (2007) cellular modelling of river catchments and reaches: advantages, limitations and prospects geomorphology, 90, pp. 192-207. cr e m o n i n i s. (2003) alcune considerazioni sul profilo longitudinale del fiume reno (italia) ann. di ric. e studi di geogr., lix, pp. 1-29. do w n s p.w. & gr e g o r y k.j. (2004) river channel management. towards sustainable catchment hydrosystems arnold, london, 395 pp. dutto f. & maraga f. (1994) variazioni idrografiche e condizionamento antropico. esempi in pianura padana il quaternario, 7, pp. 381-390. fa r a v e l l i d. & me i s i n a c. (1997) incidenza dei fattori antropici sull'evoluzione naturale dell'alveo del t. tidone (appennino pavese-piacentino) atti tic. sc. terra, 39, pp. 313-327. fuller i.c., large a.r.g., charlton m.e., heritage g.l. & milan d.j. (2003) reach-scale sediment transfer: an evaluation of two morphological budgeting approaches earth surf. process. landforms, 28, pp. 889-903. gentili b. & pambianchi g. (1987) morfogenesi fluviale ed attività antropica nelle marche centro-meridionali geogr. fis. e dinam. quat., 10, pp. 204-217. giambetti s. (1964) considerazioni sugli effetti provocati dall'estrazione di materiale litoide negli alvei di alcuni corsi d'acqua appenninici atti 1° conv. ing. idraulici del corpo del genio civile, parma, memoria d12, 13pp. gi a m p a n i c. & ra m a s c o m. (1998) analisi comparata dell'evoluzione storica dell'alveo del fiume sesia e delle piene del novembre 1968 e settembre 1993 finalizzata alla prevenzione degli effetti indotti da eventi alluvionali atti del convegno “la prevenzione delle catastrofi idrogeologiche: il contributo della ricerca scientifica”, alba, 5-7 novembre 1996, pubbl. gndci n. 1600, vol. ii, pp. 131-142. govi m. & turitto o. (1993) processi di dinamica fluviale lungo l'asta del po acqua-aria, 6, pp. 575588. ha b e r s a c k h. & pi é g a y h. (2008) river restoration in the alps and their surroundings: past experience and future challenges. in: ha b e r s a c k y h., pi é g a y h. & rinaldi m. (eds.), gravel-bed rivers vi from process understanding to river restoration, developments in earth surface processes, elsevier, pp. 703-738. ha b e r s a c k h., pi é g a y h. & ri n a l d i m. (2008) g r a v e l bed rivers 6, from process understanding to the river restoration series developments in earth surface processes, elsevier, netherlands. hicks d.m., duncan m.j., lane s.n., tal m. & westway r. (2008) contemporary morphological change in braided gravel-bed rivers: new developments from field and laboratory studies, with particular reference to the influence of riparian vegetation in: ha b e r s a c k h., pi é g a y h. & ri n a l d i m. (eds.), gravel-bed rivers vi from process understanding to river restoration, developments in 238 n. surian & m. rinaldi earth surface processes, elsevier, pp. 557-584. ja m e s l.a. & ma r c u s w.a. (2006) the human role in changing fluvial systems: retrospect, inventory and prospect geomorphology, 79, pp. 152-171. lamberti a. (1993) le modificazioni recenti verificatesi nell'asta principale del po e problemi connessi acqua-aria, 6, pp. 589-592. la m b e r t i a. & sc h i p p a l. (1994) studio dell'abbassamento dell'alveo del fiume po: previsioni trentennali di abbassamento a cremona navigazione interna, suppl. of n. 3-4, 23 pp. la n e s.n., we s t w a y r.m. & hi c k s m.d. (2003) estimation of erosion and deposition volumes in a large, gravel-bed, braided river using synoptic remote sensing earth surf. process. landforms, 28, pp. 249-271. liebault f. & piegay h. (2001) assessment of channel changes due to long-term bedload supply decrease, roubion river, france geomorphology, 3 6, pp. 167-186. lollino g., giordan d., baldo m., allasia p. & pellegrin i f. (2008) l'uso di modelli digitali del terreno come strumento per lo studio dell'evoluzione morfologica dei corsi d'acqua: proposte metodologiche e primi risultati il quaternario, questo volume. lu x.x., zhang s.r., xie s.p. & ma p.k. (2007) rapid channel incision of the lower pearl river (china) since the 1990s as a consequence of sediment depletion hydrol. earth syst. sci., 11, pp. 18971906. maraga f. (1989) ambiente fluviale in trasformazione: l'alveo-tipo pluricursale verso un nuovo modellamento nell'alta pianura padana proceedings of the international congress on geoengineering “suolosottosuolo”, torino, 27-30 september 1989, pp. 119-128. maraga f. (1992) riduzione del campo di attività fluviale e disponibilità di sedimento nei tratti d'alveo pluricursali: casi di studio nella pianura padana proceedings of the conference “fenomeni di erosione e alluvionamenti degli alvei fluviali”, univ. of ancona, 14-15 october 1991, pp. 51-62. ma r a g a f. (1999) tagli di meandro sul fiume po geologia dell'ambiente, 7 (1), pp. 3-7. ma r a g a f. & mo r t a r a g. (1981) le cave per inerti lungo i corsi d'acqua: rapporti con la dinamica fluviale boll. assoc. miner. subalpina, 18, 3-4, pp. 385-395. ma r c h e t t i m. (2002) environmental changes in the central po plain (northern italy) due to fluvial modifications and anthropogenic activit ies geomorphology, 44, pp. 361-373. meisina c. (1998) analisi dei processi evolutivi dell'alveo del t. staffora (affluente destro del f. po) atti del convegno “la prevenzione delle catastrofi idrogeologiche: il contributo della ricerca scientifica”, alba, 5-7 novembre 1996, pubbl. gndci n. 1600, vol. ii, pp. 157-167. nicholas a.p., thomas r. & quine t.a. (2006) cellular modelling of braided river form and process in: sa m b r o o k sm i t h g. h., be s t j. l., br i s t o w c. & pe t t s, g. e. (eds.), braided rivers, ias special publication 36, blackwell science, pp. 137-152. pellegrini l., maraga f., turitto o., audisio c. & duci g. (2008) evoluzione morfologica di alvei fluviali mobili nel settore occidentale del bacino padano il quaternario, questo volume. pellegrini m. & rossi a. (1967) la variazione del profilo d'equilibrio del fiume panaro e di alcuni affluenti estratto da atti soc. nat. e mat. di modena, 98, 24 pp. pellegrini m. & zarotti l. (1975) un esempio di erosione accelerata in alveo: il torrente tiepido presso maranello (modena) atti soc. nat. e mat. di modena, 106, pp. 145-156. pe l l e g r i n i m., pe r e g o s. & ta g l i a v i n i s. (1979a) l a situazione morfologica degli alvei degli affluenti emiliani del po convegno di idraulica padana, parma, 19-20 october 1979, 9 pp. pellegrini m., perego s., tagliavini s. & toni g. (1979b) la situazione morfologica degli alvei dei corsi d'acqua emiliano-romagnoli: stato di fatto, cause ed effetti proceedings of the conference “la programmazione per la difesa attiva del suolo e la tutela delle sue risorse: i piani di bacino idrografico”, modena, 28-29 june 1979, pp. 169-195. pe r e g o s., with collaboration of te l l i n i c. (1994) evoluzione naturale e antropica del medio e basso corso del f. taro (prov. di parma) acta naturalia de l'ateneo parmense, 30, pp. 5-27. piegay h., darby s., mosselman e. & surian n. (2005) a review of techniques available for delimiting the erodible river corridor: a sustainable approach to managing bank erosion river research and applications, 21, pp. 773-789. rinaldi m. (1995) dinamica di un alveo fluviale antropizzato: il fiume sieve (toscana) unpublished phd thesis, university of perugia, 223 pp. rinaldi m. (2003) recent channel adjustments in alluvial rivers of tuscany, central italy earth surf. process. and landforms, 28, pp. 587-608. ri n a l d i m. (2006) la prospettiva geomorfologica e le applicazioni nella gestione degli alvei fluviali giornate di studio “nuovi approcci per la comprensione dei processi fluviali e la gestione dei sedimenti applicazioni nel bacino del magra”, sarzana (sp), 24-25 ottobre 2006, autorità di bacino interregionale del fiume magra, pp. 39-58. rinaldi m. (2008) schede di rilevamento geomorfologico di alvei fluviali il quaternario, questo volume. ri n a l d i m. & ro d o l f i g. (1995) evoluzione olocenica della pianura alluvionale e dell'alveo del fiume sieve nel mugello (toscana) geogr. fis. e dinam. quat., 18, pp. 57-75. rinaldi m. & simon a. (1998) bed-level adjustments in the arno river, central italy geomorphology, 22, pp. 57-71. rinaldi m., simon a. & billi p. (1997) disturbance and adjustment of the arno river, central italy. ii: quantitative analysis of the last 150 years in: wa n g s.s.y., la n g e n d o e n e.j., sh i e l d s f.d. jr. (eds.), management of landscapes disturbed by channel incision, stabilization, rehabilitation, restoration, center for the computational hydroscience and engineering, university of mississippi, oxford, ms, pp. 601-606. ri n a l d i m., si m o n c i n i c. & so g n i d. (2005) v a r i a z i o n i morfologiche recenti di due alvei ghiaiosi appenninic i: il fiume trebbia ed il fiume vara 239dinamica recente ed attuale ... supplementi di geogr. fis. e dinam. quat., vii, pp. 313-319. rinaldi m. & simoncini c. (2006) studio geomorfologico del fiume magra e del fiume vara finalizzato alla gestione dei sedimenti e della fascia di mobilità autorità di bacino del fiume magra, giornata di studio “nuovi approcci per la comprensione dei processi fluviali e la gestione dei sedimenti”, sarzana (sp), 24-25 ottobre 2006, pp. 93-109. rinaldi m. & surian n. (2005) variazioni morfologiche ed instabilità di alvei fluviali: metodi ed attuali conoscenze sui fiumi italiani in: br u n e l l i m. & farabollini p. (a cura di), dinamica fluviale, ordine dei geologi delle marche, tipoli tografia c. bellabarba, pp. 203-238. rinaldi m., teruggi l., simoncini c. & nardi l. (2008) dinamica recente ed attuale di alvei fluviali: alcuni casi di studio appenninici (italia centro-settentrionale). il quaternario, questo volume. roveri e. (1965) sul ciclo d'erosione rinnovatosi lungo i corsi d'acqua dell'appennino emiliano boll. soc. geol. it., 84 (1), pp. 290-309. ru m s b y b.t., br a s i n g t o n j., la n g h a m j.a., mcle l l a n d s.j., mi d d l e t o n r. & ro l l i n s o n g. (2008) monitoring and modelling particle and reach-scale morphological change in gravel-bed r ivers: applications and challenges geomorphology, 93(1-2), pp. 40-54. sa b a t o l. (1994) human impact on alluvial environments in calabria (southern italy) mem. soc. geol. it., 48, pp. 935-941. sa b a t o l. (1999) le fiumare: corsi d'acqua ad alto rischio ambientale geologia dell'ambiente, 7, pp. 8-13. sear d.a. & archer d. (1998) effects of gravel extraction on stability of gravel-bed rivers: the wooler water, nothumberland, uk in: kl i n g e m a n p . c . , be s c h t a r.l., ko m a r p.d., br a d l e y j.b. (eds.), gravel-bed rivers in the environment, water resources publications, highlands ranch, colorado, pp. 415-432. si m o n a. (1989) a model of channel response in disturbed alluvial channels earth surf. process. and landforms, 14, pp. 11-26. surian n. (1999) channel changes due to river regulation: the case of the piave river, italy earth surf. process. landforms, 24, pp. 1135-1151. su r i a n n. (2003) impatto antropico sulla dinamica recente del fiume piave (alpi orientali) in: biancotti a. & motta m. (a cura di), risposta dei processi geomorfologici alle variazioni ambientali, m.i.u.r., glauco brigati, genova, pp. 425-440. surian n. (2006) effects of human impact on braided river morphology: examples from northern italy in: sambrook smith g.h., best j.l., bristow c. & pe t t s g.e. (eds.), braided rivers, ias special publication 36, blackwell science, pp. 327-338. su r i a n n. & ci s o t t o a. (2007) channel adjustments, bedload transport and sediment sources in a gravel-bed river, brenta river, italy earth surf. process. and landforms, 32, pp. 1641-1656. su r i a n n., pe l l e g r i n i g.b. & sc o m a z z o n e. (2005) variazioni morfologiche dell'alveo del fiume brenta indotte da interventi antropici suppl. geogr. fis. e dinam. quat., vii, pp. 339-345. surian n. & rinaldi m. (2003) morphological response to river engineering and management in alluvial channels in italy geomorphology, 5 0, pp. 307326. surian n. & rinaldi m. (2004) channel adjustments in response to human alteration of sediment fluxes: examples from italian rivers in: go l o s o v v . , be l y a e v v. & wa l l i n g d.e. (eds.), sediment transfer through the fluvial system, iahs publ. 288, pp. 276-282. surian n., rinaldi m., pellegrini l., audisio c., maraga f., te r u g g i l., tu r i t t o o. & zi l i a n i l. (2008a) channel adjustments in northern and central italy over the last 200 years. geological society of america special paper (in revisione). su r i a n n., zi l i a n i l., ci b i e n l., ci s o t t o a. & ba r u f f i f . (2008b) variazioni morfologiche degli alvei dei principali corsi d'acqua veneto-friulani negli ultimi 200 anni il quaternario, questo volume. tacconi p. & billi p. (1990) indagine sull'abbassamento del fiume po. analisi morfometrica dello stato attuale e tendenza evolutiva dell'alveo po acquagricolturambiente, vol. ii: l'alveo e il delta, società editrice il mulino, bologna, pp. 15-111. tagliavini s. (1975) aspetti e problemi geomorfologici connessi con l'attività estrattiva dell'emilia occidentale atti conv. “cave e assetto del territorio”, regione emilia romagna, studi e documentaz., 7, pp. 75-91. tazioli g.s. (1982) trasporto solido e fenomeni erosivi proceedings convegno conclusivo p.f. conservazione del suolo, cnr, roma, pp. 129134. veggiani a. (1963) ancora un esempio di danni causati dalla ripresa del ciclo erosivo dei fiumi appenninici estratto da boll. camera di commercio i.a.a., forlì, 8 pp. williams g.p. (1978) the case of the shrinking channels the north platte and platte rivers in nebraska u.s. geological survey circular, 781, 48 pp. wi l l i a m s g.p. & wo l m a n m.g. (1984) d o w n s t r e a m effects of dams on alluvial rivers u.s.geological survey professional paper, 1286, 83 pp. wi n t e r b o t t o m s.j. (2000) medium and short-term channel planform changes on the rivers tay and tummel, scotland geomorphology, 34, pp. 195208. xu jiongxin (1997) evolution of mid-channel bars in a braided river and complex response to reservoir construction: an example from the middle hanjiang river, china earth surf. process. and landforms, 22, pp. 953-965. 240 ms. ricevuto il 1° febbraio 2008 testo definitivo ricevuto il 12 maggio 2008 ms. received: february 1, 2008 final text received: may 12, 2008 n. surian & m. rinaldi imp.tertulliani& studio macrosismico del terremoto del gran sasso (italia centrale) del 5 settembre 1950: implicazioni sismotettoniche andrea tertulliani 1, fabrizio galadini 1, fabio mastino 2, antonio rossi 1 & maurizio vecchi 1 1 istituto nazionale di geofisica e vulcanologia, via di vigna murata 605, 00143 roma 2 collaboratore esterno riassunto: a. tertulliani, f. galadini, f. mastino, a. rossi & m. vecchi, studio macrosismico del terremoto del gran sasso (italia centrale) del 5 settembre 1950: implicazioni sismotettoniche. (it issn 0394-3356, 2007). il 5 settembre 1950 alle 4.08 (gmt), un forte terremoto fu avvertito in tutta l’italia centrale e arrecò gravi danni in diversi centri abitati delle province di teramo, pescara, l’aquila e rieti. questo evento è il massimo terremoto storico avvenuto nell’area del gran sasso d’italia, zona che secondo i cataloghi sismici italiani, è caratterizzata da un’attività sismica relativamente modesta. questo lavoro è uno studio di revisione del terremoto del 1950 e del periodo sismico che ne seguì tra il 1950 e il 1951. scopo della ricerca è quello di ampliare il quadro delle conoscenze su questo sisma e di inquadrarlo nel contesto sismotettonico regionale. la ricerca ha condotto al reperimento di molti documenti originali, sinora inediti, sia relativi alla scossa del 5 settembre 1950, che a quella dell’8 agosto 1951, che rappresenta l’evento più forte del periodo sismico successivo alla scossa principale. i risultati consistono in una maggiore completezza delle informazioni sul terremoto, anche relativamente al ruolo delle repliche nel quadro del danneggiamento. il numero dei punti di intensità risulta triplicato rispetto a quanto finora conosciuto. gli elementi di analisi contribuiscono al calcolo di nuovi parametri ipocentrali e a fornire una ipotesi interpretativa riguardo alla sorgente responsabile del terremoto. in base ai dati acquisiti sulla distribuzione del danno è possibile ipotizzare che il terremoto del 1950 sia stato causato da una sorgente con direzione circa eo, situata al di sotto dell’edificio strutturale della laga, tra campotosto e pietracamela. abstract: a. tertulliani, f. galadini, f. mastino, a. rossi & m. vecchi, on september 5, 1950 (04:08 gmt), a strong earthquake struck a large part of central italy, causing heavy damage in the districts of teramo, pescara, l’aquila and rieti. (it issn 0394-3356, 2007). this earthquake is considered, in the italian seismic catalogues, as the largest event which occurred in the gran sasso range area. this area is characterized by an infrequent and moderate seismicity. on the contrary several neighboring areas are prone to a high and frequent seismicity. this paper aims to reappraise the 5 september 1950 earthquake and the following seismic period, deepening our knowledge of this event from the macroseismic and seismotectonic points of view. historical research in public archives allowed us to retrieve many unpublished documents, related to the 1950 earthquake and to the strongest aftershock which occurred in 8 august 1951. very important documents are in particular the “genio civile” folders about damage reconnaissance in the provinces of teramo and rieti. results concern the large increase of intensity points, from 137 to 386 for the 1950 event, and from 33 to 94 for the 1951 event, with respect to the known literature. maximum intensities are i=viii for 1950 earthquake and i= vii for 1951. by means of the boxer code version 3.3 (gasperini et al., 1999) new epicentral parameters have been calculated from macroseismic data, together with the macroseismic magnitude values (maw=5.9±0.2, for the 1950 event and maw=5.2±0.2 for the 1951 aftershock). finally, a hypothesis about the seismogenic source responsible for the mainshock is proposed. according to the damage distribution, an ew oriented source (strike 91,5±18, length 10,7 km, width 7,4 km) can be hypothesized, located below the laga mountains, not related to known tectonic structures of the region. the seismogenic source of the 1950 earthquake could therefore be represented by a blind fault pertaining to a structural level deeper than that of the active normal faults which affects the apennine extensional domain. parole chiave: gran sasso d'italia, terremoto 1950, macrosismica, sismotettonica. keywords: gran sasso d'italia, 1950 earthquake, macroseismics, seismotectonics. il quaternario italian journal of quaternary sciences 19(2), 2006 195 214 1. introduzione la conoscenza delle caratteristiche sismotettoniche della regione abruzzese e, più in generale, dei settori appenninico ed adriatico dell'italia centrale non è omogeneamente distribuita. l'emergenza in superficie delle faglie attive responsabili di terremoti con magnitudo anche superiore a 6.5 e i dati disponibili sugli effetti di un buon numero di terremoti distruttivi hanno consentito, fin dalla fine degli anni '90, di formulare ipotesi sulle caratteristiche sismogenetiche dei settori intermontani (es. barchi et al., 2000). per contro, l'occorrenza di terremoti con magnitudo minore rispetto a quelli avvenuti all'interno della catena, la lacunosità dell'informazione sulla distribuzione del danno di alcuni tra questi terremoti e un quadro di tettonica attiva assai meno chiaro hanno reso più problematica l'elaborazione di sintesi sismotettoniche per il settore adriatico. soltanto in tempi recenti, infatti, è iniziata la pubblicazione di lavori finalizzati alla definizione delle caratteristiche sismogenetiche delle aree cosiddette "esterne" (si veda, per le marche, vannoli et al., 2004). come osservato, uno degli aspetti che ostacola la caratterizzazione sismogenetica del settore adriatico è la non completa conoscenza della distribuzione del danno nei diversi terremoti. ciò vale certamente per alcuni eventi sismici abruzzesi, tra cui vanno annoverati i terremoti che hanno interessato l'area teramana (ma anche le province di l'aquila e rieti) nel 1950 e 1951. in questa ottica, il presente lavoro intende fornire un nuovo quadro conoscitivo sulla distribuzione del danno relativa ai due eventi principali di questo periodo sismi196 a. tertulliani et al. co (5 settembre 1950, riportato con maw=5.7 e io viii=mcs e 8 agosto 1951, riportato con maw=5.3 e io vii mcs, in gruppo di lavoro cpti, 2004, di qui in avanti cpti04). pertanto, dopo un ampio capitolo di inquadramento sulle caratteristiche della tettonica attiva e sulle conoscenze sismotettoniche dei settori appenninico ed adriatico dell'italia centrale, verranno approfonditi gli aspetti della ricerca sulla distribuzione del danno dei terremoti del 1950 e 1951 e discusso il nuovo quadro conoscitivo. infine, saranno fatte alcune ipotesi sulla sorgente sismogenetica responsabile dell'evento del 1950. 2. inquadramento sismotettonico della regione colpita dal terremoto del 1950 le caratteristiche geologico-strutturali della regione abruzzese e dell'area interessata dai terremoti del 1950 e 1951 sono legate all'evoluzione tettonica dell'arco appenninico settentrionale, intendendo con ciò la porzione di catena compresa tra il molise ed il settore ligure-piemontese (es. patacca et al., 1990). in sostanza, la strutturazione sarebbe il risultato della migrazione delle unità meso-cenozoiche verso ne, mediante l'attivazione di thrust progressivamente più recenti che, nel caso abruzzese, portano le formazioni di piattaforma carbonatica o di bacino ad accavallarsi generalmente su quelle di riempimento delle avanfosse. questo motivo cinematico rappresenterebbe la risposta crostale all'arretramento flessurale della placca adriatica in subduzione verso ovest (malinverno & ryan, 1986; patacca et al., 1990; doglioni, 1995). nel corso del quaternario, il fronte compressivo più esterno si sarebbe collocato nei settori costieri o nell'offshore adriatico lungo la penisola (es., cnr-pfg, 1983; patacca et al., 1990; argnani et al., 1991; calamita et al., 1991; bigi et al., 1995a; argnani, 1998; bolis et al., 2003; scrocca, 2006). tuttavia, l'attività recente delle strutture compressive esterne è argomento di discussione. secondo alcuni autori l'attività quaternaria dei thrust esterni potrebbe essere conclusa nel corso del quaternario inferiore (es. di bucci & mazzoli, 2002 e relativa bibliografia). in area abruzzese, viene considerata inattiva dal pleistocene inferiore la struttura definita come thrust costiero, da silvi marina verso sud (bigi et al., 1995a; calamita et al., 2002). di questo fronte compressivo, il bacino di pescara rappresenterebbe l'avanfossa, con deposizione silicoclastica plio-pleistocenica (calamita et al., 2002). tuttavia, la sismica a riflessione disponibile, per motivi legati alla tecnica di acquisizione, non permette di caratterizzare l'attività tettonica pleistocenica. nelle sezioni geologiche, il piegamento della base del pleistocene inferiore, nei punti in cui il pleistocene è sovrapposto alle faglie inverse plioceniche, sarebbe legato all'interpolazione dei differenti spessori di depositi quaternari (nel tetto e nel letto dei sovrascorrimenti) derivabili dai dati di pozzo (es. calamita et al., 2002 e 2003; bolis et al., 2003; scisciani, com. pers., 2006). inattivi sono considerati anche i thrust legati alle strutture della maiella e casoli-bomba (calamita et al., 2002). per contro, l'attività quaternaria (anche tardoquaternaria) nei settori padani dell'arco appenninico settentrionale sembrerebbe più evidente (es. burrato et al., 2003). nell'area adriatica marchigiana, thrust e pieghe quaternarie sarebbero presenti nell'offshore fino a poche decine di chilometri dalla costa o a ridosso di essa (es. argnani, 1998; vannoli et al., 2004). queste evidenze geologiche per il settore padano e marchigiano-adriatico, nonché la sismicità legata a sorgenti compressive nelle aree padana e marchigiana (es. burrato et al., 2003; vannoli et al., 2004), le informazioni sullo stress in atto (montone & mariucci, 1999; mariucci et al., 1999; mariucci & müller, 2003) e l'evidenza di una litosfera in subduzione (es. amato et al., 1998b; di stefano et al., 1999; lucente et al., 1999) sembrano supportare l'ipotesi di attività recente dei fronti compressivi dell'intero arco appenninico settentrionale (o della maggior parte di esso). mentre alla fine del pliocene il fronte compressivo andava ad attestarsi in area adriatica, nelle porzioni più interne iniziava il sollevamento che ha portato alla formazione dell'attuale catena appenninica (d'agostino et al., 2001; galadini et al., 2003). contemporaneamente al sollevamento, i settori assiali dell'appennino hanno subito fagliazione legata al regime tettonico estensionale (galadini et al., 2003; centamore & nisio, 2003). l'attività delle faglie dirette ha portato alla formazione di bacini intermontani con centinaia di metri di spessore di sedimenti plio-quaternari (bosi et al., 2003). la persistenza dell'attività di alcune di tali faglie (es. faglie del fucino, ovindoli-pezza, campo imperatore, norcia, ecc., fig. 1) è testimoniata dalla dislocazione di forme e depositi del pleistocene superiore-olocene. le faglie considerate attive sono organizzate in due o tre sistemi (in funzione delle differenti visioni degli autori es. galadini & galli, 2000 e boncio et al., 2004; fig. 1) con andamento parallelo all'asse della catena e per alcune di esse si hanno evidenze sismologico-storiche e paleosismologiche di attivazione durante terremoti degli ultimi secoli (galadini & galli, 2000 e relativa bibliografia). altre faglie normali ad est della zona interessata da attività nel pleistocene superiore-olocene caratterizzate da elevati rigetti verticali (ad es. i margini occidentali della maiella e della montagna dei fiori), sono probabilmente la testimonianza di ingenti dislocazioni pree/o sin-orogeniche (scisciani et al., 2000; scisciani et al., 2001; fubelli & galadini, 2005). l'attività recente di tali faglie, ipotizzata da alcuni autori (si vedano vezzani et al., 1998 e ghisetti & vezzani, 2002, per la maiella), è probabilmente da escludersi. per quanto riguarda l'area teramana, cioè l'area interessata dal terremoto del 1950, rilevamenti finalizzati alla ricostruzione dell'evoluzione geologica tardo-quaternaria del versante orientale della montagna dei fiori hanno evidenziato l'assenza di tracce di attività recente lungo la faglia normale, a fronte di un rigetto verticale pre-quaternario di svariate centinaia di metri (fubelli & galadini, 2005). depositi di versante probabilmente attribuibili al pleistocene medio sigillano la faglia. tracce di dislocazioni recenti, evidenziate dalla presenza di scarpate di faglia in roccia, sono attribuibili a movimenti gravitativi profondi di versante. queste osservazioni sull'attività delle faglie normali più esterne nell'appennino centrale chiariscono che, probabilmente, la fagliazione normale attiva più orientale, legata a strutture di lunghezza superiore ai 15-20 km, è da riferirsi al sistema m.ti della laga-gran sasso-m. morrone (es. galadini & galli, 2000). le faglie normali più esterne sono da ritenersi inattive. il quadro strutturale dei settori esterni, per quanto 197studio macrosismico del terremoto del gran sasso ... fig. 1 schema sismotettonico dell'area colpita dal terremoto del 1950. l'andamento delle faglie normali è derivato da galadini e galli (2000), con modifiche. gli epicentri dei terremoti con maw≥5.5 sono riportati secondo quanto in gruppo di lavoro cpti (2004), tranne il terremoto del 1997 (14 ottobre, ml 5.5), la cui ubicazione epicentrale è derivata da amato et al. (1998a). il terremoto del 1943, di magnitudo maw inferiore a 5.5 (5.02), è stato inserito nello schema in quanto più volte citato nel testo. la traccia della "struttura costiera" è tratta da calamita et al. (2003). le strutture trasversali all'andamento della catena sono tratte dai lavori di adamoli, (1993) ("b" e "c", valle del tordino e valle del vomano), de alteris, (1995) ("a", definita nel lavoro come "squalo line"), vezzani et al., (1998) ("b" e "c"), bolis et al., (2003) ("a", definita nel lavoro come "roseto line"). faglie interne alla catena appenninica: 1) sistema di faglia di norcia; 2) faglia del monte vettore; 3) faglia dei monti della laga; 4) sistema di faglia dell'alta valle dell'aterno; 5) sistema di faglia assergi-campo imperatore; 6) faglia della valle del salto; 7) sistema di faglia ovindoli-pezza-campo felice-colle cerasitto; 8) sistema di faglia della media valle dell'aterno; 9) faglia del monte morrone; 10) sistema di faglia del fucino; 11) faglia del monte porrara; 12) faglia della valle del liri; 13) faglia aremogna-cinquemiglia; 14) faglia dell'alta valle del sangro. seismotectonic sketch of the 1950 earthquake area. normal faults are redrawn from galadini and galli (2000). epicentres of maw ≥5.5 earthquakes have been derived from working group cpti (2004), excluding 1997 earthquake (october 14, ml=5.5), that is from amato et al. (1998a). 1943 earthquake, maw=5.0, is anyway indicated because it has been cited in the article. the trace of the so called “coastal sstructure” line is byhas been derived from calamita et al. (2003). the faults transverseal structures trendingto the main trend of the apennine chain are have been derived from adamoli, (1993) ("b" e "c", tordino valley and vomano valley), de alteriss, (1995) ("a", defined by the authors as "squalo line"), vezzani et al. (1998) ("b" e "c"), bolis et al., (2003) ("a", defined by the authors as "roseto line"). appenninicfaults of the inner apennine chain internal faults: 1) norcia fault system; 2) mount vettore fault; 3) laga mountainss fault; 4) upper aterno valley fault system; 5) assergi-campo imperatore fault system; 6) salto valley fault; 7) ovindolipezza-campo felice-colle cerasitto fault system; 8) aterno valley fault system; 9) mount morrone fault; 10) fucino fault system; 11) mount porrara fault; 12) liri valley fault; 13) aremogna-cinquemiglia fault; 14) upper sangro valley fault. 198 attiene al regime tettonico in atto, potrebbe essere complicato dalla presenza di faglie ad andamento trasversale alla catena. elementi strutturali con questa geometria sarebbero evidenziati dai dati offshore. in particolare, ci si riferisce ad una faglia ("squalo lineament" in de alteris 1995; "roseto line" in bolis et al., 2003) a cinematica incerta (forse trascorrente destra) in corrispondenza del proseguimento a mare della valle del vomano. in prossimità di tale struttura, i thrust marchigiani in offshore sembrano subire una brusca interruzione e non proseguire verso sud. la presenza di elementi strutturali trasversali alle principali direttrici della catena non sarebbe esclusiva di questo settore (si vedano per esempio la c.d. linea delle tremiti, e le sorgenti sismogenetiche responsabili della sequenza sismica di san giuliano di puglia del 2002; valensise et al., 2004; di luccio et al., 2005; di bucci et al., 2006; scrocca, 2006). da quanto finora evidenziato, emerge una sostanziale differenza delle conoscenze sul quadro strutturale relativo al regime tettonico in atto dell'area in esame. decisamente meglio conosciuto è il contesto strutturale del settore di catena appenninica. le aree esterne sono, invece, meno caratterizzate, sia per quanto attiene alla attività delle strutture compressive ad andamento appenninico (di cui non si può affermare con certezza od escludere l'attività recente), sia per quanto attiene la presenza ed il ruolo delle faglie ad andamento trasversale alla catena. questo quadro conoscitivo si riflette, ovviamente, sulle ipotesi sismotettoniche, in particolare per quanto riguarda la definizione delle sorgenti sismogenetiche dei terremoti principali. in pratica, terremoti al di sopra della soglia del danno interessano sia il settore interno (in particolar modo) che quello esterno della regione abruzzese (es. cpti04). i grandi terremoti storici che hanno interessato la catena, ben caratterizzati per quanto riguarda la distribuzione delle intensità, sono attribuibili a faglie normali con direzione appenninica. ciò vale per i terremoti del 14 gennaio 1703 (galli et al., 2005), 2 febbraio 1703 (es., moro et al., 2002) e 13 gennaio 1915 (galadini & galli, 1999 e relativa bibliografia). il confronto tra schema delle faglie attive e distribuzione della sismicità evidenzia che i terremoti di magnitudo moderata si collocano al tip dei segmenti principali (es. 1461, 1639, 1762, 1904, 1958, 1984) o in corrispondenza dei segmenti minori di più lunghi sistemi di faglia (es. 1328, 1599, 1730, 1799, 1859, 1979, 1997). quest'ultima relazione riguarda soprattutto l'area umbro-marchigiana (es. galadini et al., 1999), mentre la prima è più tipica dell'area abruzzese. sembrerebbero anche definite, grazie ad informazioni paleosismologiche ed archeosismologiche, le sorgenti di due terremoti distruttivi dell'antichità, vale a dire l'evento del ii secolo d.c. (riportato convenzionalmente come 101 d.c. in cpti04) e quello del 508 d.c. il primo è tentativamente attribuito alla sorgente del m. morrone (galadini & galli, 2001), il secondo alla sorgente del fucino, cui è pure riferito il terremoto del 1915 (galadini & galli, 1999). nell'ambito del settore interno della catena, sono invece non definite le sorgenti causative della sequenza del 1349, per i più scarsi dati sulla distribuzione del danno. completamente diverso è il quadro delle conoscenze sismogenetiche per le zone esterne, in particolare per quelle abruzzesi. i l terremoto del 1706 (maw=6.6, in cpti04) ha interessato l'intera regione circostante la montagna della maiella, con gravi danni nella piana di sulmona e nella valle dell'aventino. ma danni significativi sono attribuiti a tutti gli abitati della fascia pedemontana della maiella. l'evento del 1881 (maw=5.6) ha interessato il settore compreso tra la maiella e la costa adriatica con danni notevoli a orsogna, lanciano, guardiagrele, castel frentano. il terremoto del 1933 (maw=5.7) ha un'area di danneggiamento paragonabile a quella del 1706, ma con livello del danno sensibilmente minore. i terremoti del 1950 (maw=5.7) e del 1951 (maw=5.3), oggetto della presente nota, hanno interessato soprattutto un'ampia area dell'abruzzo teramano ed abitati delle province di l'aquila e rieti. per nessuno di questi eventi sono disponibili ipotesi attendibili sulla sorgente causativa. tuttavia, alcune considerazioni possono essere fatte per i terremoti del 1706 e del 1950 in base alla bibliografia disponibile. per il primo dei due, l'utilizzo dell'algoritmo boxer (che definisce la geometria della faglia causativa a partire da una certa distribuzione del danno; gasperini et al., 1999) ha generato una sorgente con direzione no (gasperini et al., 1999) che però non ha avuto, finora, riscontro geologico. secondo meletti et al. (1988) il terremoto del 1706 potrebbe essere attribuito all'attivazione di una parte della c.d. linea ortona-roccamonfina, elemento strutturale con direzione da ne-so a ns che separerebbe l'arco appenninico settentrionale da quello meridionale. tuttavia, evidenze di attività recente lungo questa fascia di deformazione non sono state ancora osservate. per quanto riguarda il 1950, pur mancando ipotesi sismogenetiche conclusive, sembra utile menzionare il meccanismo focale pubblicato da gasparini et al. (1985). questo suggerisce la possibile attivazione di una struttura con direzione trasversale alla catena (neso). va comunque ricordato che i dati sismometrici a disposizione sono qualitativamente e quantitativamente tali da rendere necessario considerare con cautela tale meccanismo focale. a differenza del settore adriatico abruzzese, per quello marchigiano (a nord dell'area rappresentata in figura 1) è disponibile un'interpretazione sismogenetica che lega i terremoti di magnitudo moderata con l'attivazione di sorgenti con meccanismo tipo thrust (vannoli et al., 2004). nel lavoro citato, in sostanza, si ammette il ruolo sismogenetico delle strutture compressive costiere marchigiane. 3. il terremoto del 5 settembre 1950 e l’attività sismica nell’area del gran sasso nel periodo 1950-1951 il biennio 1950-1951 vede l’area del gran sasso – monti della laga sede di un’attività sismica abbastanza intensa, culmine della quale è il terremoto del 5 settembre 1950 (04.08 gmt). secondo i cataloghi sismici nazionali questo evento è il più significativo di quelli con origine nell’area, che nel complesso è sede di una moderata attività sismica. secondo i l catalogo parametrico dei terremoti italiani (cpti04) l’epicentro a. tertulliani et al. 199 ricade alle pendici nord del gran sasso. in precedenza, la zona settentrionale della provincia di teramo era stata colpita dal terremoto marchigiano del 3 ottobre 1943 (epicentro a nord di ascoli piceno, fig. 1), i cui effetti si sommeranno probabilmente ai danni del 1950. la scossa principale fu preceduta di pochi minuti da una forte scossa premonitrice avvertita in molte località (di filippo & marcelli, 1951; ing, 1950). il quadro degli effetti vide due vittime e un centinaio di feriti, oltre ad una estesa area di danneggiamento tra le province di rieti, teramo, pescara e ascoli piceno. alla scossa del 5 settembre 1950 seguirono diverse repliche: tra queste le più significative furono quelle del 18 settembre 1950 con lievi danni nell’area di montereale (monachesi & castelli, 1992), quella dell’8 marzo 1951 con danni nell’area di pizzoli e campotosto (postpischl, 1985) e quella del 21 maggio 1951, sconosciuta alla letteratura sismologica, con lievi danni nell’area di campli. l’8 agosto 1951 (19.56 gmt) un altro forte terremoto colpì le stesse aree provocando nuovi e diffusi danneggiamenti in diverse località. 2.1 stato delle conoscenze l’unico studio specifico pubblicato sul terremoto del 1950 è quello di di filippo e marcelli (1951), che costituisce pertanto il cardine delle conoscenze per tutte le successive revisioni (monachesi & castelli, 1992; monachesi & stucchi, 1997). il database dom4.1 (monachesi & stucchi, 1997), che contiene un piano quotato di 137 località, apporta solo qualche modifica rispetto a quello dello studio succitato. secondo il cpti04, il terremoto del 5 settembre 1950 (04.08 gmt) è caratterizzato da un’intensità epicentrale (io) di viii grado mcs e da un valore di magnitudo (maw) pari a 5.7. nel lavoro di di filippo e marcelli (1951) sono riportati, oltre al campo macrosismico, un elenco di 137 località di segnalazione con la rispettiva intensità assegnata, ma solo per 13 di queste località sono descritti, in modo spesso sommario, gli effetti del terremoto. probabilmente gli autori si avvalsero, senza una specifica citazione, delle cartoline sismiche. queste ultime erano schede prestampate che in caso di terremoto venivano compilate da corrispondenti locali ed inviate all’ufficio centrale di meteorologia ed ecologia agraria che era preposto dallo stato a raccogliere le informazioni inerenti i risentimenti sismici sul territorio. sulle cartoline sismiche il corrispondente descriveva sommariamente gli effetti del terremoto nella località di pertinenza. questo sistema di raccolta di dati macrosismici è stato per circa 70 anni un’importante fonte di informazione sui sismi che avvenivano in territorio italiano. di filippo e marcelli calcolarono la localizzazione ipocentrale, (h < 10 km) (vedi tabella 1) su base strumentale. per dare un’idea delle varie interpretazioni riguardo alla localizzazione del terremoto del 1950, elenchiamo in tabella 1 quelle riportate in letteratura. il terremoto dell’8 agosto 1951 alle ore 21.56 (ora locale) viene parametrizzato in cpti04 con magnitudo maw=5.3 ed intensità epicentrale di vii mcs. i danni più gravi furono riscontrati nella provincia di teramo. secondo il cpti04 l’epicentro ricadrebbe al confine tra marche ed abruzzo. consultando i cataloghi sismici nazionali si evidenzia come la bibliografia relativa a questo evento sia piuttosto limitata. il record del cpti04 ha come fonte di riferimento i l database macrosismico dom4.1 (monachesi e stucchi, 1997), che si limita a valutare l’intensità sulla base di repertori sismologici tradizionali. nella tabella 2 è mostrata l’evoluzione della stima tab. 1 parametri del terremoto del 5 settembre 1950, ore 04.08, come riportati nei principali cataloghi e nelle altre fonti. le localizzazioni ing, iss e di filippo e marcelli sono strumentali, mentre le altre sono epicentri macrosismici. caloi et al. riprendono di filippo e marcelli. epicentral parametres of the september 5, 1950 earthquake, 04:08 gmt, reported in the main seismic catalogues and other sources. ing, iss and di filippo and marcelli are instrumental locations, the others are macroseismic epicentres. caloi et al. followed di filippo and marcelli. coordinate fonte area epicentrale latit. longit. i0 mcs magnitudo ing (1950) 42,508 13,350 m=5.1 iss (1950) gran sasso 42,600 13,500 viii di filippo e marcelli (1951) campotosto 42,513 13,327 viii m=5.4 caloi et al. (1969) gran sasso 42,516 13,327 ix m=7.1 gasparini et al. (1985) 42,600 13,500 m=5.5 pospischl (1985) campotosto 42,516 13,350 viii ml=5.4 camassi e stucchi (1997) gran sasso 42,500 13,600 viii ms=5.6 cpti04 gran sasso 42,516 13,657 viii maw=5.7 tab. 2 parametri epicentrali del terremoto dell’8 agosto 1951, ore 19:56, come riportati nei principali cataloghi e nelle altre fonti conosciute. epicentral parametres of the august 8, 1951 earthquake, 19:56 gmt, reported in the main seismic catalogues and other sources. coordinate fonte area epicentrale latit. longit. i0 mcs magnitudo ing (1951) 42,600 13,500 m=5.1 iss (1951) gran sasso 42,600 13,500 gasparini et al. (1985) 42,600 13,500 vii-viii m=4.9 pospischl (1985) cortino 42,600 13,500 viii ml=4.9 camassi e stucchi (1997) monti della laga 42,750 13,500 viii ms=5.0 cpti04 monti della laga 42,704 13,546 vii-viii maw=5.3 studio macrosismico del terremoto del gran sasso ... 200 dei parametri epicentrali di questo terremoto attraverso i cataloghi sismici e gli autori che ne fanno menzione: pfg (postpischl, 1985), nt4.1 (camassi & stucchi, 1997) e cpti (cpti04). il database dom4.1 fornisce un piano quotato con 33 località (fig. 6). la massima intensità fu assegnata alla sola località di canzano (prov. te), stimata del vii-viii grado, mentre alle altre località furono assegnate intensità comprese tra il ii ed il vi grado. 2.2 ricerca di dati al fine di migliorare e riordinare il quadro delle conoscenze sul terremoto del 5 settembre 1950, nonché fornire elementi utili alla comprensione sismotettonica dell’evento, è stata avviata una ricerca sistematica su fonti bibliografiche e documentarie relativa a tutti gli eventi sismici avvenuti nell’area durante il biennio 19501951. di seguito, viene fornito un quadro delle fonti utilizzate. giornali sono stati consultati i quotidiani nazionali più importanti ed uno locale (vedi elenco in bibliografia). l’indagine ha messo in evidenza come le notizie sul terremoto del 5 settembre 1950 siano presenti sui giornali fino a circa 2 settimane dopo l’evento, prima con le cronache degli inviati speciali, ricche di particolari, e poi con le corrispondenze locali. il terremoto del 8 agosto 1951 scompare molto più rapidamente dalle cronache. per una ventina di località i giornali sono risultati essere la sola fonte disponibile, fornendo quindi un contributo in termini di notizie inedite utili a completare il quadro degli effetti. documenti d’archivio gran parte della ricerca documentale è stata svolta presso gli archivi di stato delle province interessate dagli eventi, l’aquila (asa), rieti (asr), teramo (ast), pescara (asp). sono stati inoltre consultati l’archivio centrale dello stato di roma (acsr), l’archivio del genio civile di teramo (agct) e l'archivio storico dell’istituto nazionale di geofisica e vulcanologia (aingv). la documentazione di interesse è costituita principalmente dalla corrispondenza tra le autorità locali (sindaci, prefetto e sottoprefetto) e centrali (governo e ministeri). questo tipo di documentazione, contenuta nei fondi della prefettura (asa e ast), descrive in modo sintetico la situazione locale post-evento, limitandosi talvolta a far riferimento a documenti non più presenti nelle stesse buste. in alcuni casi, tuttavia, si tratta di resoconti abbastanza dettagliati, come le liste dei danneggiati con la descrizione del danno di cui si richiede il risarcimento; in altri casi sono stati rinvenuti documenti elencanti le somme elargite dai comitati di soccorso o direttamente dai comuni, come primo contributo per le situazioni più gravi. un altro fondo risultato utile è quello del genio civile (asp e asr), contenente le perizie di sopralluogo effettuate dai tecnici del genio civile presso molte località della provincia, e domande di risarcimento dei danni fatte dalla cittadinanza. particolarmente ricche di informazioni sono state alcune relazioni dei tecnici del genio civile della provincia di rieti, riguardanti i comuni di accumoli ed amatrice. una menzione particolare merita l’archivio del genio civile di teramo (agct), per la disponibilità e la quantità del materiale messo a disposizione. si tratta soprattutto delle pratiche istruite per le richieste di sussidi fatte dai proprietari degli immobili per riparazioni dei danni prodotti dal terremoto. la pratica era composta principalmente dalla domanda di sussidio, a cui erano allegati il preventivo dei lavori e la successiva verifica fatta dai tecnici del genio civile. da questi sussidi venivano escluse per legge le case rurali. data la mole documentale, l’indagine ha riguardato preferenzialmente le pratiche istruite dal genio civile, e approvate per il sussidio a conferma dell'avvenuto danno. per alcuni comuni dell'area teramana, le informazioni reperite in questo archivio sono risultate le uniche disponibili. in totale sono state consultate 46 buste relative ai danni avvenuti in 32 comuni, incluso teramo, con informazioni dettagliate anche per molte frazioni. il lavoro ha riguardato migliaia di incartamenti, e ha permesso di estrarre dall’enorme mole di documenti circa 2000 pratiche utili, relative a richieste di risarcimento. l'effettiva utilità dei documenti dell'archivio del genio civile di teramo ai fini di una assegnazione dell'intensità è comunque controversa per motivi legati all’iter burocratico. le pratiche avevano un percorso lungo e tortuoso che veniva spesso concluso dopo molto tempo (anche più di dieci anni). nel computo dei danni veniva sovente tenuto conto del cumulo con quelli dovuti a scosse successive, soprattutto con quelli causati dal terremoto dell’8 agosto 1951 (intensità vii mcs). inoltre era talvolta dichiarato l'intento di procedere alla riparazione anche dei danni di guerra. la mancanza poi, come accennato, della descrizione di danni alle proprietà rurali fa sì che il quadro generale degli effetti deducibile da questo tipo di documentazione sia purtroppo parziale. si tratta tuttavia degli unici documenti che descrivono in dettaglio il tipo di danneggiamento subito dagli immobili, fornendo anche indicazioni sul numero delle abitazioni interessate. e’ stata consultata la collezione delle cartoline sismiche dell’archivio storico dell’istituto nazionale di geofisica e vulcanologia (aingv), che raccoglie le corrispondenze da oltre 170 località, per il terremoto del 1950, e da 45 per il terremoto dell’8 agosto 1951. la consultazione delle cartoline sismiche è risultata basilare in quanto ha consentito di incrementare il numero delle località di risentimento conosciute e di migliorare in generale la qualità dei dati attraverso dettagliate descrizioni dei risentimenti. sono stati infine consultati alcuni manoscritti a carattere sismologico provenienti dalla collezione de panfilis (de panfilis, 1950-1959; de panfilis, sec. xx), che non hanno però fornito informazioni significative. per quanto riguarda il terremoto del 5 settembre 1950, la grande mole di informazioni raccolte e la rilettura critica delle fonti presenti nella letteratura nota hanno contribuito alla valutazione dell’intensità macrosismica, anche se purtroppo non è stato possibile reperire lo stesso tipo di fonte per tutte le località esaminate (vedi fig. 2a). e’ stata inoltre individuata una replica sconosciuta alla letteratura sismologica, avvenuta il 21 maggio 1951, che provocò lievi danni nell’area di campli. nella figura 2a è illustrato il contributo delle varie fonti rispetto al numero di località per le quali le stesse fonti sono disponibili. il documento d’archivio e la a. tertulliani et al. cartolina sismica rappresentano le tipologie di fonte più diffuse. hanno fornito dati rispettivamente per 182 e 175 località su 386 totali esaminate in questo studio. naturalmente la quantità delle fonti non è proporzionale alla loro efficacia nella descrizione degli effetti dovuti all'evento sismico, e quindi ai fini dell'assegnazione dei valori di intensità. inoltre per circa il 52% (201 su 386) delle località abbiamo a disposizione un solo tipo di citazione. per queste località non è stato possibile incrociare informazioni provenienti da diversi tipi di documenti. al termine dell’analisi delle fonti è stato comunque assegnato il valore di intensità a 336 località (vedi appendice a). per il terremoto dell’8 agosto 1951 tra le opere a carattere tecnico-scientifico consultate ve ne è una sola, che aggiunge ulteriori informazioni a quelle conosciute. il lavoro in questione è quello di marcelli e pannocchia (1962-1963) in cui si propone una mappa macrosismica realizzata con le notizie delle cartoline sismiche. nella figura 2b è evidenziato il contributo delle varie fonti rispetto al numero di località per le quali le stesse fonti sono disponibili. in generale, si può affermare che il terremoto del 1951 resta molto meno documentato dell’evento del 1950. 201 fig. 2a istogramma relativo alla distribuzione delle informazioni secondo il tipo di fonte relativa al terremoto del 1950. distribution of the information related to the 1950 earthquake, according to the kind different types of source. fig. 2b istogramma relativo alla distribuzione delle informazioni secondo il tipo di fonte relativa al terremoto del 1951. distribution of information related to the 1951 earthquake, according to the kind different types of source. per avere un quadro più completo della sismicità di riferimento, soprattutto in relazione al possibile cumulo dei danni nel periodo studiato, è stata approfondita la ricerca sull’evento del 12 marzo 1950 (18.15 gmt), segnalato dal bollettino sismico dell’ing (ing, 1950) con l’indicazione “accumoli vii mcs”, per chiarire se avesse potuto influenzare lo scenario del danneggiamento ricostruito. lo spoglio dei giornali ha dato esito negativo non essendovi riportata alcuna notizia su questa scossa. non è stato possibile effettuare una verifica sulle cartoline sismiche essendo mancante la parte della collezione riguardante il mese di marzo 1950. dalla documentazione consultata presso l’archivio di stato di rieti non sono emersi documenti riguardanti questa scossa. i giornali e la documentazione di archivio riportano sempre informazione sui terremoti di particolare rilievo del biennio 1950-1951. il silenzio delle fonti sulla scossa in oggetto fa ritenere pertanto che questa sia stata di intensità alquanto inferiore (≤ v mcs) rispetto a quanto segnalato sul bollettino ing (1950) e successivamente sui cataloghi pfg (postpischl, 1985) e cpti (cpti04). 2.3 assegnazione dell’intensità l’intensità macrosismica è stata stimata utilizzando la scala mercalli-cancani-sieberg (mcs) (mcs, 1930), ritenuta più adatta in riferimento al periodo storico in cui è avvenuto il terremoto ed al tipo di edilizia diffusa nell’area. le costruzioni colpite dal terremoto erano generalmente in pietra semplice, spesso non squadrata, costruite senza ausilio di cordoli. la maggioranza delle abitazioni era costituita al massimo da due piani in elevazione. e’ stata assegnata l’intensità a frazioni e località aventi un nucleo urbano rappresentativo, con l’esclusione di piccoli centri abitati formati da pochissime abitazioni e le case sparse, e sulla base di un corredo di informazioni significative sia qualitativamente (descrizione del risentimento) che quantitativamente (numero di elementi di diagnosi). le località maggiormente danneggiate dal terremoto del 5 settembre 1950 si trovano lungo una fascia a cavallo della catena del gran sasso e dei monti della laga, fra le province di rieti, l’aquila e teramo (fig. 3). a diverse località, sia frazioni che capoluoghi di comune, è stato assegnato l’viii grado mcs (vedi appendice a), in virtù di danni molto gravi alle strutture, muri portanti, tetti e solai, diversi collassi totali e di un diffuso danneggiamento generale alle abitazioni. molto estesa è risultata alla fine l’area di vii, a coprire quasi tutta la provincia di teramo e parte delle province di pescara, l’aquila, rieti e ascoli piceno. in tutta questa regione il danno è risultato largamente diffuso nel territorio, soprattutto sulle strutture portanti e le coperture. in molti casi è stata assegnata un’intensità incerta tra il vii e l’viii grado, a causa dell’incompletezza del quadro diagnostico. molti crolli o danni hanno interessato case isolate o edifici rurali, sparsi nelle campagne. in questi casi, il danno non è stato quantificato in termini di intensità. l’informazione è risultata comunque utile per completare e definire il quadro dell’area di maggior danno. la scarsità di informazioni non ha reso possibile una valutazione del risentimento e di conseguenza l'asstudio macrosismico del terremoto del gran sasso ... segnazione di un valore di intensità ad una serie di località. ad esse è stato assegnato il codice d per segnalare la generica presenza di danni. allo stesso modo la lettera f indica un generico risentimento dell’evento. e’ stato anche ricostruito il piano quotato del terremoto del 8 agosto 1951, avvenuto sempre nella stessa area (io= vii) (vedi appendice b). i danni si sono certamente cumulati a quelli dell’evento dell’anno precedente e pertanto la discriminazione degli effetti non sempre è stata possibile. nelle province di teramo, l’aquila e rieti le condizioni di stabilità degli edifici a circa un anno dal terremoto del 1950 erano ancora precarie. nella provincia di teramo la maggior parte delle domande per la ricostruzione furono accettate, infatti, ad oltre dieci anni dalla scossa. pertanto, gran parte dei lavori di recupero edilizio iniziarono quasi sicuramente dopo il terremoto dell’8 agosto 1951. alla luce di ciò appare manifesta la difficoltà di interpretare con univocità le informazioni relative ai danneggiamenti in termini di valutazione dell’intensità macrosismica. 3. risultati e discussione 3.1 la distribuzione del danno l’evento del 5 settembre 1950 interessò abitati che già avevano subito gli effetti dal forte terremoto di offida (prov. di ascoli piceno) del 3 ottobre 1943. questo ebbe una intensità all’epicentro pari all’ viii-ix mcs, e causò gravi danni anche nel teramano (monachesi & stucchi, 1997) con is pari al vii-viii a teramo ed altre località. inoltre, nell’immediato secondo dopoguerra, la maggior parte degli edifici, per mancanza di manutenzione, non erano in buone condizioni. al proposito, di filippo e marcelli (1951) asseriscono ”… le case sono malsicure ed assolutamente inadatte a resistere ad un terremoto”. dal punto di vista della ricerca macrosismica il quadro di riferimento si presenta quindi abbastanza complesso. tuttavia l’indagine archivistica ha dato risultati soddisfacenti permettendo il reperimento di numerosi nuovi dati che consentono di definire meglio la distribuzione dell’intensità sul territorio per entrambi i terremoti. se confrontiamo il piano quotato del terremoto del 5 settembre 1950, ottenuto nel presente lavoro con quello riportato in dom4.1, possiamo notare un notevole incremento del numero dei punti di intensità. si è passati, infatti, da 137 a 386 località (fig. 4). l’intensità massima risentita è l’viii mcs ed è la stessa di quella riportata da dom4.1 e da di filippo e marcelli (1951). le località con tale intensità sono passate da 10 a 14, mentre a 14 località è stata assegnata una intensità di vii-viii. il quadro del danneggiamento risulta essere stato 202 fig. 3 campo macrosismico del terremoto del 5 settembre 1950. con la d sono indicate in carta le località per le quali vi è segnalazione generica di danno non sufficiente per l’assegnazione dell’intensità. con f sono indicate quelle località per le quali vi è segnalazione generica di risentimento insufficiente per l’assegnazione dell’intensità. intensity map of the 5 september 1950. code d indicates generic damage; this information is not sufficient to assess an intensity value to the locality. code f indicates localities where the shock has been generally felt. a. tertulliani et al. più grave entro una fascia orientata circa eo posta tra il lago di campotosto in provincia di l’aquila e la valle del vomano (fig. 3); in questa area sono concentrate le intensità più elevate. intensità più basse sono state assegnate alle località ubicate verso la costa adriatica dove il terremoto fu avvertito con violenza, senza tuttavia registrare danni significativi (figg. 3 e 5). la magnitudo mw calcolata con il codice boxer 3.3 (gasperini et al., 1999) a partire dal piano quotato risulta pari a 5.9±0.2 lievemente più alta del 5.7 proposto in cpti04. a fronte dell’incremento del numero di località di viii grado, dovuto al grande dettaglio dell’indagine macrosismica, l’area di massima intensità risulta ridotta rispetto a quella delineata nella mappa di di filippo e marcelli (1951). l’apparente contraddizione tra il leggero aumento della magnitudo e la diminuzione dell’area di massimo danneggiamento, se rapportati con cpti04, è probabilmente spiegabile con il maggior numero di punti di massimo grado utilizzati, contestualmente alla loro concentrazione in un’area ridotta. analogamente al terremoto del 1950, anche per quello dell’8 agosto 1951, possiamo notare un notevole incremento del numero dei punti di intensità. si è passati, infatti, da 33 località documentate a 94 (fig. 6). l’intensità massima risentita, attribuita a 4 località, è stata del vii mcs, leggermente inferiore all’intensità massima riportata da dom4.1 (vii-viii mcs), alla sola 203 fig. 5 dettaglio della distribuzione delle intensità del terremoto del 5 settembre 1950 e ipotesi di sorgente sismogenetica (box blu) dall’applicazione dell’algoritmo boxer (gasperini et al., 1999). zoom of the intensity map of the 5 september 1950 with the indication of the seismogenic source (blue box) computed by means of the boxer code (gasperini et al., 1999). fig. 4 terremoto del 1950. confronto del numero di località ricadenti nelle classi di intensità tra i piani quotati di dom4.1 e del presente lavoro. non sono riportate le località per le quali: abbiamo solo segnalazione di danni (d = damage) ed intensità non assegnata e quelle per le quali abbiamo solo l’indicazione di un generico risentimento (f = felt) ed intensità non assegnata. le località per le quali abbiamo una segnalazione negativa sono riportate nel grafico con n. earthquake of 1950. comparison between number of localities, grouped into intensity classes, for dom4.1 and the present issue. the localities quoted as (d = damage) and (f = felt) are not taken into account for this graph. localities where the shock was not felt are reported in the graph with n. studio macrosismico del terremoto del gran sasso ... località di canzano. in appendice b è riportato il piano quotato relativo al terremoto; al termine dell’analisi delle fonti è stato assegnato un valore di intensità a 80 località sulle 94 riportate nel piano quotato. nella figura 7 è riportata la mappa della distribuzione dell’intensità ricavate dal piano quotato. il danneggiamento risulta essere stato più grave entro una fascia orientata circa eo posta tra montereale e isola del gran sasso passando per il massiccio del gran sasso ed interessando le province di l’aquila e teramo. verso la costa adriatica e le province di ascoli piceno e pescara il terremoto causò un forte risentimento senza provocare danni. la magnitudo mw calcolata risulta pari a 5.2 (gasperini et al., 1999). dall’analisi del piano quotato possiamo dire che questo terremoto ha interessato all’incirca la stessa area epicentrale di quello del 5 settembre 1950. questa analogia, insieme alla vicinanza temporale tra i due eventi, ci fa propendere a definire la scossa dell’8 agosto 1951 come una forte replica del terremoto del 5 settembre 1950, diversamente da quanto sinora considerato. 204 fig. 6 terremoto del 1951. confronto del numero di località ricadenti nelle classi di intensità tra i piani quotati di dom4.1 e del presente lavoro. non sono riportate le località per le quali: abbiamo solo segnalazione di danni (d = damage) ed intensità non assegnata e quelle per le quali abbiamo solo l’indicazione di un generico risentimento (f = felt) ed intensità non assegnata. 1951 earthquake. comparison between the number of localities, grouped into intensity classes, for dom4.1 and the present issue. the localities quoted as (d = damage) and (f = felt) are not taken into account for this graph. localities where the shock was not felt are reported in the graph with n. fig. 7 campo macrosismico del terremoto del 8 agosto 1951. con la d sono indicate in carta le località per le quali vi è segnalazione generica di danno non sufficiente per l’assegnazione dell’intensità. con f sono indicate quelle località per le quali vi è segnalazione generica di risentimento insufficiente per l’assegnazione dell’intensità. intensity map of the 8 august 1951. code d indicates generic damage; this information is not sufficient to assess an intensity value to the locality. code f indicates localities where the shock has been generically felt. a. tertulliani et al. 3.2 ipotesi sismogenetiche la ricostruzione del panorama degli effetti ci consente di riflettere sulla questione, sinora non risolta, della sorgente del terremoto del 1950. nel caso della scossa del 5 settembre 1950, il livello del danno è elevato su un'area decisamente ampia. l'asse maggiore della distribuzione dei punti di vii-viii/viii mcs (circa 55 km) è, in effetti, paragonabile a quello proprio di eventi caratterizzati da più elevata magnitudo in italia centrale (es. 14 gennaio 1703, maw=6.8, area di vii-viii mcs allungata, tra visso e cittaducale per circa 60 km). tale considerazione, a fronte della minore energia associata all'evento del 1950 porterebbe ad ipotizzare per esso un'origine più profonda di quella della maggior parte dei terremoti appenninici. inoltre, la distribuzione del danno mostra una sorta di orientamento preferenziale, circa eo, sia per il "campo vicino" che per quello "lontano". nel caso delle maggiori intensità, questo effetto di allungamento del campo macrosismico potrebbe essere dovuto ad una distribuzione degli abitati condizionata dalla morfologia eo del settore settentrionale della catena del gran sasso. tale ipotesi, tuttavia, non può essere avanzata nel caso dei punti di intensità minore, relativi ad abitati lontani dall'area del citato massiccio montuoso. e' pertanto ipotizzabile che la direzione preferenziale della distribuzione del danno sia da considerarsi come l'effetto della geometria della sorgente. l'utilizzo dell'algoritmo boxer vers 3.3 (gasperini et al., 1999) evidenzia che la distribuzione dei punti di intensità è compatibile con una sorgente con direzione ca. eo (azimuth 91,5±18), lunghezza 10,7 km, larghezza 7,4 km. l'andamento trasversale all'asse principale della catena appenninica sembrerebbe confermato dall'unico meccanismo focale disponibile (definito, però, su una ridotta informazione sismometrica) sebbene esso mostri direzioni ne-so dei piani focali (gasparini et al., 1985). in base a quanto sopra, è possibile ritenere che il terremoto del 1950 sia stato causato da una sorgente con direzione ca. eo, o comunque trasversale all'andamento della catena appenninica, ubicata a profondità superiore a quella a cui si originano i terremoti distruttivi dei settori intermontani (in genere fino a 10-15 km). e' da notare, in effetti, che la distribuzione del danno, e la relativa elaborazione con l'algoritmo boxer, suggeriscono una sorgente ubicata trasversalmente all'edificio strutturale dei monti della laga. tuttavia, la catena della laga è interessata da una faglia normale con direzione no-se, attiva nel pleistocene sup.-olocene, considerata come espressione superficiale di una delle sorgenti sismogenetiche appenniniche (galadini & galli, 2000). ciò farebbe pensare, e l'ampiezza dell'area danneggiata lo confermerebbe, che la sorgente eo del terremoto del 1950 si possa collocare ad un livello strutturale più profondo di quello a cui si colloca la sorgente con direzione no-se. come osservato nell'inquadramento sismotettonico, tracce di una faglia trasversale all'asse principale della catena appenninica sono osservabili nel quadro strutturale offshore (de alteris, 1995; bolis et al., 2003), ed una faglia viene dubitativamente ubicata in terra lungo la valle del vomano ed un'altra lungo la valle del tordino da più autori (adamoli, 1981 e 1993; vezzani et al., 1998). l'elemento strutturale che avrebbe originato l'evento del 1950 potrebbe essere una faglia profonda che interessa la litosfera adriatica in subduzione e che limita settori di tale placca caratterizzati da diversa velocità di sprofondamento/arretramento (si vedano ad esempio le varie ipotesi di bigi et al., 1995b; bolis et al., 2003). in tal senso, la sorgente sismogenetica rappresenterebbe un segmento di un sistema di faglia legato al processo di arretramento flessurale in atto. in alternativa, la sorgente potrebbe essere parte di un elemento strutturale passivo, ereditato da un quadro strutturale anche pre-orogenico (si vedano i condizionamenti pre-orogenici alla strutturazione in catena del margine appenninico esterno in calamita et al., 2002) o legato al processo flessurale non più in atto e riattivato nel presente regime tettonico. a tal proposito, si rammenta che questa è una delle ipotesi pubblicate per giustificare l'origine della sequenza di san giuliano di puglia del 2002 (valensise et al., 2004; di luccio et al., 2005), dovuta a sorgenti con direzione eo. per quanto concerne il terremoto del 1951, l'ubicazione dei suoi effetti nella zona danneggiata dall'evento precedente (fatto non desumibile dai piani quotati finora disponibili) fa pensare che esso rappresenti una forte replica del terremoto del 1950. anche per il 1951 si evidenzia, soprattutto per i gradi di intensità minori, un allungamento del piano quotato in direzione trasversale alla catena appenninica. tuttavia, il minor numero dei punti disponibili suggerisce cautela nell'ipotizzare una possibile geometria della sorgente causativa. 4. conclusioni la revisione macrosismica dei terremoti abruzzesi del 5 settembre 1950 e dell’8 agosto 1951 ha portato a modificare sostanzialmente il quadro conoscitivo di questi eventi. il livello di conoscenza è infatti migliorato sia in relazione al numero di punti di intensità, sia rispetto alla qualità dell’informazione in essi contenuta. in tabella 3 vengono elencati i parametri proposti nel presente studio, mentre in figura 8 sono mostrate le localizzazioni proposte nel presente studio rispetto a quelle esistenti in letteratura. i principali risultati ottenuti possono essere così sintetizzati: 205 tab. 3 parametri epicentrali e magnitudo macrosismiche derivati dalla revisione dei terremoti del 1950 e del 1951. epicentral parametres and macroseismic magnitude computed by means of the reappraisal of the 1950 and 1951 earthquakes. terremoto mw imax i0 lat n lon e azimuth lxw (km) 05/09/1950 5.9±0.2 viii viii 42.538 13.390 91.5±18 10.7x7.4 08/08/1951 5.2±0.2 vii vii 42.524 13.436 studio macrosismico del terremoto del gran sasso ... il già citato incremento qualitativo e quantitativo dell’informazione sugli eventi, e quindi l’aumento significativo del livello di conoscenza. al termine dello studio i punti di piano quotato, che sono la fotografia dell’impatto del terremoto sul territorio, risultano triplicati rispetto a quanto noto finora in letteratura per entrambi gli eventi. rispetto al lavoro di di filippo e marcelli (1951), e conseguentemente a cpti (cpti04), l’area dei massimi effetti del terremoto del 1950 viene ridimensionata nell’estensione e risulta decisamente orientata in direzione circa eo, tra le province di l’aquila e teramo. il terremoto dell’8 agosto 1951, nonostante il notevole miglioramento della base informativa, resta poco vincolato. il set di dati è abbastanza disomogeneo, da una parte per effetto dell’oggettivo cumulo dei danni, dall’altra per l’uso, in ambito amministrativo, di indicare l’insieme dei danni subiti a seguito di più eventi (sismici e non). l’impossibilità di distinguere tra gli effetti dei due terremoti, può aver portato ad una sovrastima del danno in alcune località danneggiate nel 1951. la localizzazione del terremoto del 1951 proposta in questo studio è molto prossima a quella del terremoto del settembre 1950, concordemente con quanto mostrano i piani quotati dei due eventi. in sintesi la scossa dell’agosto 1951 si può configurare come una forte replica dell’evento del 1950, avvenuta ad 11 mesi dalla scossa principale, e quindi riferibile ad uno stesso sistema di sorgenti causative. l’intensità massima di questo terremoto viene leggermente ridimensionata, passando da vii-viii a vii. per quanto riguarda gli aspetti sismotettonici, risulta, dalla distribuzione degli effetti e dalla loro modellazione con l’algoritmo boxer (gasperini et al., 1999), una probabile origine su una sorgente sismogenetica con direzione all'incirca eo di cui, peraltro, a tutt’oggi non sono state individuate tracce in superficie riconducibili ad attività tettonica recente. d'altronde, la distribuzione del danno su un'ampia area (comprendente anche territori delle province di rieti e di l'aquila) potrebbe spiegarsi con una profondità ipocentrale maggiore di quella generalmente osservata nel caso di forti terremoti appenninici. ciò suggerisce che il terremoto del 1950 possa essere riferito ad una sorgente con direzione ca. eo, tra il lago di campotosto e pietracamela, attiva in un livello strutturale inferiore a quello degli edifici strutturali della laga e del gran sasso. ringraziamenti un particolare ringraziamento va all’ufficio tecnico del territorio di teramo, nelle persone dell’ing. e. ricci, della d.ssa l. di stefano e del sig. p. perozzi, che hanno permesso la consultazione dell’archivio del 206 fig. 8 confronto tra le diverse localizzazioni presenti in letteratura e quelle proposte nel presente lavoro, relative ai terremoti del 5/9/1950 e 8/8/1951. 1) monachesi e stucchi, 1997; 2) gdl cpti, 2004; 3) postpischl, 1985; 4) gasparini et al., 1985; 5) iss, 1950 e 1951; 6) di filippo e marcelli, 1951; 7) ing, 1950 e 1951; 8) presente lavoro. comparison between the different localizations of the 5/9/1950 and 8/8/1951 earthquakes as reported in literature, and as proposed in this issue. 1) monachesi e stucchi, 1997; 2) gdl cpti, 2004; 3) postpischl, 1985; 4) gasparini et al., 1985; 5) iss, 1950 e 1951; 6) di filippo e marcelli, 1951; 7) ing, 1950 e 1951; 8) present study. a. tertulliani et al. genio civile della provincia di teramo, consentendo l’accesso a documentazione altrimenti irraggiungibile. un nostro grazie va anche al dott. adriano ruggeri per averci concesso la visione di documenti e foto del proprio archivio personale. 5. bibliografia e documentazione adamoli l. (1981) attività sismica e caratteri sismotettonici dell’abruzzo teramano. notizie dell’economia teramana, 1-2-3, 46-56. adamoli l. 1993 studio dell’ambiente geologico, geomorfologico ed idrogeologico della provincia di teramo. assessorato urbanistica e pianificazione territoriale della provincia di teramo, collana territorio e ambiente, vol. 2, 117 pp. amato a., azzara r., chiarabba c., cimini g.b., cocco m., di bona m., margheriti l., mazza s., mele f., selvaggi g., basili a., boschi e., courboulex f., deschamps a., gaffet s., bittarelli g., chiaraluce l., piccinini d., ripepe m. (1998a) the 1997 umbria-marche, italy, earthquake sequence: a first look at the main shocks and aftershocks. geophys. res. lett. 25 (15), 28612864. amato a., azzara r., basili a., chiarabba c., ciaccio m.g., cimini g.b., di bona m., frepoli a., hunstad i., lucente f.p., margheriti l., mariucci m.t., montone p., nostro c., selvaggi g. (1998b) geodynamic evolution of the northern apennines from recent seismological studies. mem. soc. geol. it. 52, 337-343. argnani a. (1998) structural elements of the adriatic foreland and their relationships with the front of the apennine fold-and-thrust belt. mem. soc. geol. it., 52, 647-654. argnani a., artoni a., ori g.g., roveri m. (1991) l’avanfossa centro-adriatica: stili strutturali e sedimentazione. studi geol. cam., vol. spec. 1991/1, 371-381. barchi m., galadini f., lavecchia g., messina p., michetti a.m., peruzza l., pizzi a., tondi e., vittori e. (a cura di) (2000) sintesi delle conoscenze sulle faglie attive in italia centrale. cnr gruppo nazionale per la difesa dai terremoti, 62 pp. bigi s., calamita f., paltrinieri w. (1995a) modi e tempi della strutturazione della catena centroappenninica abruzzese dal gran sasso alla costa adriatica. studi geol. cam., vol. spec. 1995/2, 7785. bigi s., calamita f., cello g., centamore e., deiana g., paltrinieri w., ridolfi m. (1995b) evoluzione messiniano-pliocenica del sistema catenaavanfossa nell’area marchigiano-abruzzese esterna. studi geol. cam., vol. spec. 1995/1, 29-35. bolis g., carruba s., casnedi r., perotti c.r., ravaglia a., tornaghi m. (2003) compressional tectonics overprinting extensional structures in the abruzzo periadriatic foredeep (central italy) during pliocene times. boll. soc. geol. it., 122, 251-266. boncio p., lavecchia g., pace b. (2004) defining a model of 3d seismogenic sources for seismic hazard assessment applications: the case of central apennines (italy). jou.of seism., 8, 407-425. bosi c., galadini f., giaccio b., messina p., sposato a. (2003) plio-quaternary continental deposits in the latium-abruzzi apennines: the correlation of geological events across different intermontane basins. il quaternario, 16, 55-76. burrato p., ciucci f., valensise g. (2003) an inventory of river anomalies in the po plain, northern italy: evidence for active blind thrust faulting. ann geoph, 46, 865-882. calamita f., cello g., centamore e., deiana g., micarelli a., paltrinieri w., ridolfi m. (1991) stile deformativo e cronologia della deformazione lungo tre sezioni bilanciate dall’appennino umbromarchigiano alla costa adriatica. studi geol. cam., vol. spec. 1991/1, 295-314. calamita f., scisciani v., montefalcone r., paltrinieri w., pizzi a. (2002) l’ereditarietà del paleomargine dell’adria nella geometria del sistema orogenico centro-appenninico: l’area abruzzese esterna. mem. soc. geol. it., 57, 355-368. calamita f., paltrinieri w., pelorosso m., scisciani v., tavarnelli e. (2003) inherited mesozoic architecture of the adria continental paleomargin in the neogene central apennines orogenic system, italy. boll. soc. geol. it., 122, 307-318. caloi p., coladonato u., spadea m.c. (1969) sismicità in relazione alla tettonica ed accumulo delle tensioni elastiche nella regione abruzzese nel periodo 1900-1970, ann. geof., 22, 309-357. camassi r., stucchi m. (1997) nt4.1, un catalogo parametrico di terremoti di area italiana al di sopra della soglia del danno. cnr-gndt, vers. nt4.1, luglio 1997, milano, http://emidius.mi.ingv.it/nt/ centamore e., nisio s. (2003) effects of uplift and tilting in the central-northern apennines (italy). quaternary int., 101/102, 93-101. cnr-pfg (1983) structural model of italy and gravity map. quaderni de la ricerca scientifica, 114. d'agostino n., jackson j.a., dramis f., funiciello r., (2001) interactions between mantle upwelling, drainage evolution and active normal faulting: an example from the central apennines (italy). geophys.l jou. int.l 147, 475-497. de alteris g. (1995) different foreland basins in italy: examples from the central and southern adriatic sea. tectonophysics 252, 349-373. di bucci d., mazzoli s. (2002) active tectonics of the northern apennines and adria geodynamics: new data and a discussion. jou. of geodyn. 34, 687707. di bucci d., ravaglia a., seno s., toscani g., fracassi u., valensise g. (2006) seismotectonics of the southern apennines and adriatic foreland: insights on active regional e-w shear zones from analogue modeling. tectonics. 25, tc4015, doi:10.1029/ 2005tc001898. di filippo d., marcelli l. (1951) uno studio del terremoto del gran sasso d’italia del 5 settembre 1950. ann. di geof., iv, 2: 213-239. di luccio f., piscini a., pino n.a., ventura g. (2005) reactivation of deep faults beneath southern apennines: evidence from the 1990-1991 potenza seismic sequences. terra nova, 17, 586-590. di stefano r., chiarabba c., lucente f. p., amato a. (1999) crustal and uppermost mantle structure in italy from the inversion of p-wave arrival times: 207studio macrosismico del terremoto del gran sasso ... geodynamic implications. geophys. j. int. 139, 483-498. doglioni c. (1995) geological remarks on the relationships between extension and convergent geodynamic settings. tectonophysics 252, 253-267. fubelli g., galadini f. (2005) il versante occidentale della montagna dei fiori: caratteristiche geomorfologiche per la caratterizzazione della tettonica attiva. in: f. galadini (a cura di), indagini sismotettoniche per la realizzazione del piano di emergenza provinciale di protezione civile. convenzione prov. teramo-ingv, relazione finale inedita, 5-14. galadini f., galli p. (1999) the holocene paleoearthquakes on the 1915 avezzano earthquake faults (central italy): implications for active tectonic in the central apennines. tectonophysics, 308, 143170. galadini f., galli p. (2000) active tectonics in the central apennines (italy) – input data for seismic hazard assessment. nat. haz., 22, 225-270. galadini f., galli p. (2001) archaeoseismology in italy: case studies and implications on long-term seismicity. jou. of earthq. eng., 5, 35-68. galadini f., galli p., leschiutta i., monachesi g., stucchi m. (1999) active tectonics and seismicity in the area of the 1997 earthquake sequence in central italy: a short review. jou. of seism., 3, 167175. galadini f., messina p., giaccio b., sposato a. (2003) early uplift history of the abruzzi apennines (central italy): available geomorphological constraints. quaternary international, 101/102, 125-135. galli p., galadini f., calzoni f. (2005) surface faulting in norcia (central italy): a "paleoseismological perspective". tectonophysics, 403, 117-130. gasparini c., iannaccone g., and scarpa r. (1985) fault-plane solutions and seismicity of the italian peninsula, tectonophysics, 117, 59-78. gasparini p., bernardini f., valensise g., boschi e. (1999) defining seismogenic sources from historical felt reports. bull. seism soc. am., 89, 94110. ghisetti f., vezzani l. (2002) normal faulting, extension and uplift in the outer thrust belt of the central apennines (italy): role of the caramanico fault. basin res., 14, 225-236. gruppo di lavoro cpti (2004) catalogo parametrico terremoti italiani, versione 2004 (cpti04). ingv, bologna. [consultabile alla pagina web http://emidius.mi.ingv.it/cpti/]. ing (1950) bollettino sismico mensile dell’istituto nazionale di geofisica (ing). [è consultabile online presso il sito di sismos in formato pdf alla pagina web http://sismos.ingv.it/index2.php?bframe=bulletins.php] ing (1951) bollettino sismico mensile dell’istituto nazionale di geofisica (ing). [è consultabile online presso il sito di sismos in formato pdf alla pagina web http://sismos.ingv.it/index2.php?bframe=bulletins.php] iss (1950) international union of geodesy and geophysics (editor), international seismological summary (i.s.c.) for 1950. kew observatory, richmond. iss (1951) international union of geodesy and geophysics (editor), international seismological summary (i.s.c.) for 1951. kew observatory, richmond. lucente f.p., chiarabba c., cimini g.b., giardini d. (1999) tomographic constraints on the geodynamic evolution of the italian region. j. geophys. res. 104, 20,307-20,327. malinverno a., ryan w.b.f. (1986) extension in the tyrrhenian sea and shortening in the apennines as result of arc migration driven by sinking of the lithosphere. tectonics 5, 227-245. marcelli l., pannocchia g. (1962-1963) l’attività sismica nella zona delle sorgenti del peschiera. ann. geof., xv, 4: i° parte, pp. 301-334; xvi, 4, ii° parte, pp. 645-680. mariucci m.t., müller b. (2003) the tectonic regime in italy inferred from borehole breakout data. tectonophysics 361, 21-35. mariucci m.t., amato a., montone p. (1999) recent tectonic evolution and present stress in the northern apennines. tectonics 18, 108-118. mcs (1930) scala macrosismica mercalli-cancanisieberg, in sieberg a. geologie der erdbeben, handbuch der geophysic, 2 (iv), tabb. 102 e 103, 552-554, berlin. meletti c., patacca e., scandone p. and figliuolo b. (1988) il terremoto del 1456 e la sua interpretazione nel quadro sismotettonico dell'appennino meridionale, in: b. figliuolo (ed.), il terremoto del 1456, osservatorio vesuviano, istituto italiano di studi filosofici, storia e scienze della terra, 1, 71108. monachesi g., castelli v. (1992) sismicità dell’area aquilano-teramana dall’analisi “attraverso i cataloghi”. regione abruzzo – gndt, osservatorio geofisico sperimentale di macerata, rapporto riservato. monachesi g., stucchi m. (a cura di) (1997) dom4.1 un database di osservazioni macrosismiche di terremoti di area italiana al di sopra della soglia del danno. cnr-gndt. [consultabile alla pagina web http://emidius.mi.ingv.it/dom] montone p., mariucci m.t., 1999 active stress along the ne external margin of the apennines: the ferrara arc, northern italy. jou. of geodyn. 28, 251-265. moro m., bosi v., galadini f., galli p., giaccio b., messina p., sposato a. (2002) analisi paleosismologiche lungo la faglia del m. marine (alta valle dell'aterno): risultati preliminari. il quaternario, 15, 267-278. patacca e., sartori r., scandone p., (1990) tyrrhenian basin and apenninic arcs: kinematic relations since late tortonian times. mem. soc. geol. it. 45, 425-451. postpischl d. (a cura di) (1985) catalogo dei terremoti ital iani dall’anno 1000 al 1980. consiglio nazionale delle ricerche, progetto finalizzato geodinamica (cnr-pfg). quaderni de “la ricerca scientif ica”, n. 1145, 2b, pp. 239. bologna. scisciani v., calamita f., bigi s., de girolamo c., paltrinieri w. (2000) the influence of syn-orogenic normal faults on pliocene thrust system develop208 a. tertulliani et al. ment: the maiella structure (central apennines, italy). mem. soc. geol. it., 55, 193-204. scisciani v., calamita f., tavarnelli e., rusciadelli g., ori g.g., paltrinieri w. (2001) foreland-dipping normal faults in the inner edges of syn-orogenic basins: a case from the central apennines, italy. tectonophysics, 330, 211-224. scrocca d. (2006) thrust front segmentation induced by differential slab retreat in the apennines (italy). terra nova, 18, 154-161. valensise g., pantosti d., basili r. (2004) seismology and tectonic setting of the 2002 molise, italy, earthquake. earthq. spectra, 20, s23-s27. vannoli p., basili r., valensise g. (2004) new geomorphic evidence for anticlinal growth driven by blind-thrust faulting along the northern marche coastal belt (central italy). jou. of seismol., 8, 297-313. vezzani l., ghisetti f., bigozzi a., follador u., casnedi r. (1998) carta geologica dell’abruzzo alla scala 1:100.000. s.el.ca., firenze. giornali l’avanti di milano 1950 marzo 2-13, settembre 5-19. l’avanti di milano, 1951 maggio 20-30, agosto 3-15. l’avvenire d’italia di bologna, 1950 marzo 3-18, settembre 6-23. l’avvenire d’italia di bologna, 1951 maggio 22-30, giugno 30 – luglio 1, agosto 3-21. corriere del giorno di taranto, 1950 marzo 2-10, settembre 3-20. corriere della sera di milano, 1950 marzo 4-21, settembre 5-21. corriere della sera di milano, 1951 maggio 17-31, giugno 29-30, agosto 1-22. la gazzetta di livorno, 1950 marzo 2-13, settembre 3-30. gazzetta del mezzogiorno di bari, 1950 marzo 2-15, settembre 3-20. gazzetta del mezzogiorno di bari, 1951 maggio 21-30, agosto 3-20. il giornale dell’emilia di bologna, 1950 marzo 2-13, settembre 3-30. il giornale dell’emilia di bologna, 1951 marzo 8-11, maggio 21-30, agosto 2-22, settembre 1-7. il giornale di napoli, 1950 gennaio 1 – dicembre 31. il giornale d’italia di roma, 1950 marzo 4-17, settembre 5-30. il giornale d’italia di roma, 1951 marzo 7-11, maggio 18-31, giugno 27 – luglio 2, agosto 2-15, 17-22, settembre 1-8. il giornale del pomeriggio quotidiano indipendente del mezzogiorno di napoli, 1950 marzo 2/3 – 13/14, settembre 2/3 – 29/30. il giornale del pomeriggio quotidiano indipendente del mezzogiorno di napoli, 1951 marzo 7/8 – 8/9, maggio 7/8-8/9, 21/22-30/31, giugno 28/29 – luglio 2/3, 18/19 – 21/22, agosto 1/2-settembre 8/9. l’italia di milano, 1950 marzo 2-14, settembre 3-22. la libertà d’italia di roma, 1950 marzo 2-14, settembre 5-20. il mattino di napoli, 1950 settembre 3-25. il mattino di napoli, 1951 marzo 8-11, maggio 20-30, agosto 2-21. il mattino dell’italia centrale di firenze, 1950 marzo 221, settembre 3-25. il mattino dell’italia centrale di firenze, 1951 maggio 16-31, giugno 28-30, agosto 2-25. il messaggero di roma, 1950 marzo 2-16, settembre 530. il messaggero di roma, 1951 marzo 8-11, maggio 2031, agosto 1-23, settembre 1-8. il momento di roma, 1950 maggio 21-23, settembre 130. il momento di roma, 1951 marzo 8-10, maggio 20-26, agosto 2-22. il momento sera di roma, 1950 marzo 2-20, settembre 3-26. il momento sera di roma, 1951 marzo 6-11, maggio 20-31, giugno 28-30, agosto 2-23, settembre 1-7. nuova gazzetta del popolo di torino, 1950 marzo 2-15, settembre 3-21 il paese di roma, 1950 marzo 2-20, settembre 5-30. il paese di roma, 1951 marzo 8-11, maggio 21-31, giugno 29 – luglio 1, agosto 2-20, settembre 1-7. il paese sera di roma, 1950 marzo 2-14, settembre 3-30. il paese sera di roma, 1951 marzo 8-10, aprile 20-21, maggio 8, 22-29, settembre 1-7. la nazione di firenze, 1950 marzo 3-18, settembre 5-23. la nazione di firenze, 1951 marzo 8-11, maggio 20-30, giugno 29 – luglio 1, agosto 1-19. la nuova stampa di torino, 1950 marzo 2-21, settembre 3-21. la nuova stampa di torino, 1951 maggio 20 – giugno 2, giugno 29 – luglio 3, agosto 2-23. la nuova stampa sera di torino, 1950 marzo 2/313/14, settembre 2/3settembre 30/ ottobre 1. la nuova stampa sera di torino, 1951 marzo 7/8 – 9/10, maggio 7/8 – 9/10, 21/22 – 30/31, luglio 18/19 – 21/22, luglio 31/agosto 1 – settembre 8/9. il nuovo corriere di firenze, 1950 marzo 2-14, settembre 3-30. l’osservatore romano di città del vaticano, 1950 marzo 2-20/21, settembre 3-20. l’osservatore romano di città del vaticano, 1951 maggio 21/22-27, agosto 3-23. il popolo di roma, 1950 marzo 2-21, settembre 3-22. il quotidiano di roma, 1950 marzo 3-15, settembre 3-20. il quotidiano di roma, 1951 marzo 8-10, maggio 8-29, agosto 2-17, settembre 1-5. il risorgimento – il mattino di napoli, 1950 marzo 2-20. roma di napoli, 1950 settembre 5-30. roma di napoli, 1951 marzo 8-10, maggio 7-8, 23-29, settembre 1-7. il secolo xix di genova, 1950 marzo 3-12, settembre 522. il tempo di roma, 1950 marzo 2-20, settembre 5-30. il tempo di roma. 1951 marzo 8-12, maggio 21-30, giugno 29 – luglio 1, settembre 1-9. il tirreno di livorno, 1950 marzo 2-14, settembre 3-21. l’umbria di perugia, 1950 luglio 1settembre 30. l’unità di roma, 1950 marzo 2-14, settembre 3-30. l’unità di roma, 1951 marzo 8-10, aprile 21, maggio 929, giugno 30, luglio 20-21, agosto 3-17, settembre 2-6. the rome daily american di roma, 1950 marzo 2-14, settembre 3-20. voce adriatica di ancona, 1950 marzo 2-20, settembre 5-30. voce adriatica di ancona, 1951 marzo 8-11, maggio 20-31, giugno 29 – luglio 1, agosto 2-25, settembre 110. 209studio macrosismico del terremoto del gran sasso ... documenti di archivio archivio centrale dello stato: fondo pubblica sicurezza. categorie annali. busta 100. 1950. sezione ii c3. pubblica calamità. fondo pubblica sicurezza. categorie annali. busta 95. 1951. sezione ii c3. pubblica calamità. fondo pubblica sicurezza. categorie annali. busta 92. 1952. sezione ii c3. pubblica calamità. fondo ministero interni. telegrammi ufficio cifra 1950, settembre, arrivo. archivio di stato de l’aquila: fondo “gabinetto prefettura”, busta 146. xxi. 3b. ag. 1950-1958. archivio di stato di pescara: fondo genio civile: buste 1, fasc. 22. fondo genio civile: buste 7, fasc. 110 bis, terremoti e frane 1915-1959. fondo genio civile: buste 8, fasc. 127, terremoto1950. fondo genio civile: buste 15, fasc. 238, terremoto1950. fondo genio civile: buste 48, fasc. 1330, terremoto. fondo genio civile: buste 63, fasc. 1328, terremoto. archivio di stato di rieti: fondo genio civile. busta 1. atti contabili 1950 rimborso terremoto. fondo genio civile. busta 2. atti vari. fondo genio civile. busta 3. atti vari. fondo genio civile. busta 150. lavori urgenti abitati amatrice e accumoli dopo il terremoto del 1950 – altri comuni. archivio di stato di teramo: fondo gabinetto prefettura. busta 146. xxi. 3b. ag. 1950-1958. fondo prefettura. busta 1 servizio ispettivo terremoto 1950. servizio ispettivo nei comuni della provincia. fondo prefettura. busta 12 pubblicazione mensile l’eco di san gabriele. archivio del genio civile di teramo: i documenti consultati, raccolti in cartelle, non sono attualmente catalogati. segue un elenco di cartelle consultate nel quale viene indicata la dicitura presente sul dorso delle cartelle medesime. basciano. t. 50. dal n. 1 al -. pratiche istruite. bisenti. terremoto 5-9-1950. legge 1-10-1951, n. 1133. pratiche istruite dal n. 1 al. campli, arsita. terremoto. t. 50, pratiche istruite. campli. terremoto 5-9-1950. legge 1-10-1951, n. 1133. pratiche istruite dal n. 1 al n. 60. campli. terremoto 5-9-1950. legge 1-10-1951, n. 1133. pratiche istruite dal n. 61 al n. 130. campli. terremoto 5-9-1950. legge 1-10-1951, n. 1133. pratiche istruite dal n. 131 al n. 180. campli. terremoto 5-9-1950. legge 1-10-1951, n. 1133. pratiche istruite dal n. 181 al n. 260. campli. t. 50. legge 1-10-1951, n. 1133. pratiche istruite dal n. 261. castel castagna t. 50. pratiche accertate dal n. 1 al. istruite. castelli. terremoto 5-9-1950. legge 1-10-1951, n. 1133. pratiche istruite dal n. 1 al -. cellino attanasio. terremoto 1950. pratiche istruite. cermignano. terremoto 5-9-1950. legge 1-10-1951, n. 1133. pratiche istruite dal n. 1 al -. civitella del tronto. terremoto 5-9-1950. legge 1-101951, n. 1133. pratiche istruite dal n. 1 al -. cortino. terremoto 5-9-1950. legge 1-10-1951, n. 1133. pratiche istruite dal n. 3 al -. colledara. terremoto 5-9-1950. legge 1-10-1951, n. 1133. pratiche istruite dal n. 1 al 160. colledara. terremoto 5-9-1950. legge 1-10-1951, n. 1133. pratiche istruite dal n. 160 al. -. colledara. terremoto 5-9-1950. legge 1-10-1951, n. 1133. pratiche istruite dal n. 361al. -. comitato comunale t. 50 (civitella, campli, tossicia, cermignano, colledara, isola, teramo, rocca s. m.). crognaleto. terremoto 5-9-1950. legge 1-10-1951, n. 1133. pratiche istruite dal n. 1 al n. 270. crognaleto. terremoto 5-9-1950. legge 1-10-1951, n. 1133. pratiche istruite dal n. 271 al. -. fano adriano, giulianova, mosciano s. a., montefino. terremoto 5-9-1950. legge 1-10-1951, n. 1133. pratiche istruite. montorio al vomano. terremoto 5-9-1950. legge 1-101951, n. 1133. pratiche istruite dal n. 1 al n. 80. montorio al vomano. terremoto 5-9-1950. legge 1-101951, n. 1133. pratiche istruite dal n. 81 al -. nereto. terremoto 5-9-1950. legge 1-10-1951, n. 1133. pratiche istruite. notaresco, penne s. a., pietracamela. terremoto 5-91950. legge 1-10-1951, n. 1133. pratiche istruite. rocca s. m., silvi, roseto, s. omero, torano, tortoreto. terremoto 5-9-1950. legge 1-10-1951, n. 1133. pratiche istruite. isola gran sasso. terremoto 5-9-1950. domande dal n. 72 al n. 141. isola gran sasso. terremoto 5-9-1950. domande dal n. 311 al-. rocca s. m., pietracamela. terremoto 5-9-1950. torricella s. t. 50. pratiche istruite dal n. 1 al n. 137. tossicia. t. 50. pratiche istruite dal n. 1 al n. 70. tossicia. terremoto 5-9-1950. legge 1-10-1951, n. 1133. pratiche istruite dal n. 1 al n. 150. tossicia. t. 50. pratiche istruite dal n. 151 al-. valle castellana. terremoto 5-9-1950. legge 1-101951, n. 1133. pratiche istruite dal n. 1 al n. 50. varie. terremoto 5-9-1950. archivio dell' istituto nazionale di geofisica e vulcanologia “cartoline sismiche” dell' uff. centr. di meteorologia ed ecologia agraria. de panfilis m., 1950-1959. schede relative a terremoti. (manoscritto). de panfilis m., sec. xx. studio sui terremoti italiani dal 1930 al 1952. (manoscritto). peronaci f., 1950-1959. schede relative a terremoti. (manoscritto). 210 a. tertulliani et al. appendice a piano quotato del terremoto del 5 settembre 1950 (ore 04.08 gmt) località prov lat n lon e i mcs accumoli ri 42,694 13,248 80 arsita te 42,501 13,783 80 bisenti te 42,528 13,802 80 capricchia (amatrice) ri 42,622 13,340 80 colledara te 42,540 13,681 80 fano adriano te 42,552 13,538 80 isola del gran sasso d’italia te 42,501 13,661 80 marana (montereale) aq 42,494 13,222 80 mascioni (campotosto) aq 42,529 13,347 80 nocella (campli) te 42,720 13,677 80 pinaco (amatrice) ri 42,608 13,291 80 poggio cancelli (campotosto) aq 42,561 13,327 80 san giovanni (montereale) aq 42,506 13,276 80 tottea (crognaleto) te 42,553 13,467 80 aringo (montereale) aq 42,554 13,268 75 arischia (l’aquila) aq 42,419 13,342 75 campli te 42,726 13,686 75 campotosto aq 42,558 13,369 75 capitignano aq 42,520 13,301 75 castel castagna te 42,544 13,718 75 castelli te 42,489 13,712 75 cellino attanasio te 42,586 13,859 75 montereale aq 42,522 13,246 75 ortolano (campotosto) aq 42,519 13,423 75 pizzoli aq 42,435 13,303 75 poggio delle rose (cermignano) te 42,571 13,810 75 tarignano (barete) aq 42,455 13,280 75 tossicia te 42,545 13,648 75 amatrice ri 42,628 13,290 70 antrodoco ri 42,414 13,076 70 bagnolo (amatrice) ri 42,631 13,232 70 barete aq 42,450 13,283 70 barisciano aq 42,325 13,592 70 basciano te 42,596 13,740 70 battaglia (campli) te 42,714 13,637 70 borbona ri 42,511 13,137 70 cabbia (montereale) aq 42,483 13,199 70 campovalano (campli) te 42,728 13,663 70 casali di sotto (amatrice) ri 42,602 13,190 70 castelnuovo (campli) te 42,727 13,687 70 cermignano te 42,590 13,794 70 cesaproba (montereale) aq 42,498 13,187 70 civitella casanova pe 42,364 13,889 70 civitella del tronto te 42,771 13,668 70 colleminuccio (teramo) te 42,688 13,716 70 colli (amatrice) ri 42,628 13,273 70 configno (amatrice) ri 42,616 13,258 70 cortino te 42,633 13,543 70 faiano (montorio) te 42,564 13,630 70 faiete (rocca santa maria) te 42,661 13,548 70 farindola pe 42,440 13,823 70 fioli (rocca santa maria) te 42,648 13,472 70 frattoli (crognaleto) te 42,575 13,465 70 illica (accumoli) ri 42,702 13,265 70 leonessa ri 42,568 12,963 70 miano (teramo) te 42,618 13,708 70 molviano (campli) te 42,761 13,718 70 montorio al vomano te 42,584 13,629 70 morge (campli) te 42,739 13,704 70 nerito (crognaleto) te 42,547 13,479 70 padula (cortino) te 42,590 13,473 70 paganica aq 42,358 13,473 70 paranesi (rocca santa maria) te 42,687 13,501 70 pellescritta (montereale) aq 42,508 13,205 70 penna s. andrea te 42,594 13,773 70 penne pe 42,457 13,928 70 pietracamela te 42,523 13,554 70 poggio casoli (accumoli) ri 42,687 13,274 70 poggio d'api (accumoli) ri 42,721 13,295 70 posta ri 42,524 13,097 70 preta (amatrice) ri 42,616 13,346 70 riano (rocca santa maria) te 42,663 13,492 70 rocciano (teramo) te 42,626 13,666 70 roiano (campli) te 42,703 13,637 70 s. benedetto (amatrice) ri 42,627 13,264 70 s. capone (amatrice) ri 42,678 13,288 70 s. giusta (amatrice) ri 42,643 13,253 70 s. tommaso (amatrice) ri 42,685 13,292 70 salle pe 42,177 13,961 70 scorrano (cellino attanasio) te 42,592 13,820 70 sommati (amatrice) ri 42,642 13,309 70 spiano (teramo) te 42,607 13,668 70 teramo te 42,659 13,704 70 terzone (leonessa) ri 42,616 13,070 70 tevere (rocca santa maria) te 42,664 13,490 70 tino (accumoli) ri 42,712 13,252 70 torricella sicura te 42,659 13,656 70 tozzanella (tossicia) te 42,543 13,632 70 valle san giovanni (teramo) te 42,621 13,617 70 ville di fano (montereale) aq 42,531 13,198 70 acquasanta terme ap 42,771 13,411 65 alzano (tossicia) te 42,553 13,643 65 appignano (castiglione m.r.) te 42,544 13,850 65 appignano del tronto ap 42,897 13,668 65 aquilano (tossicia) te 42,556 13,624 65 arquata del tronto ap 42,771 13,296 65 assergi (l’aquila) aq 42,414 13,505 65 azzinano (tossicia) te 42,555 13,632 65 bacugno (posta) ri 42,547 13,126 65 borgo velino ri 42,405 13,059 65 cagnano amiterno aq 42,459 13,232 65 camarda (l’aquila) aq 42,391 13,494 65 carpineto della nora pe 42,333 13,860 65 casale (amatrice) ri 42,669 13,286 65 cassino (accumoli) ri 42,679 13,226 65 castel del monte aq 42,364 13,727 65 catignano pe 42,346 13,951 65 civitaquana pe 42,324 13,899 65 colle moresco (amatrice) ri 42,644 13,234 65 collebrincioni (l’aquila) aq 42,398 13,416 65 collecorvino pe 42,459 14,015 65 colleposta (accumoli) ri 42,661 13,205 65 collespada (accumoli) ri 42,665 13,234 65 domo (amatrice) ri 42,657 13,238 65 elice pe 42,518 13,968 65 floriano (campli) te 42,772 13,751 65 211studio macrosismico del terremoto del gran sasso ... folignano ap 42,820 13,633 65 fonte del campo (accumoli) ri 42,694 13,256 65 grisciano (accumoli) ri 42,732 13,269 65 guazzano (campli) te 42,733 13,644 65 loreto aprutino pe 42,433 13,988 65 macchia (accumoli) ri 42,668 13,257 65 montebello di bertona pe 42,419 13,872 65 ornano grande (colledara) te 42,532 13,652 65 ornano piccolo (colledara) te 42,542 13,656 65 palozza (tossicia) te 42,556 13,674 65 pescosansonesco pe 42,242 13,874 65 pianella pe 42,398 14,050 65 poggio vitellino (amatrice) ri 42,651 13,267 65 preturo (l’aquila) aq 42,377 13,295 65 rio (amatrice) ri 42,664 13,290 65 roccafinadamo (penne) pe 42,476 13,825 65 roccasalli (accumoli) ri 42,655 13,195 65 s. giovanni (accumoli) ri 42,693 13,208 65 santa vittoria (montereale) aq 42,549 13,234 65 sassa (l’aquila) aq 42,352 13,299 65 teora (barete) aq 42,425 13,266 65 trimezzo (cittareale) ri 42,645 13,121 65 valle castellana te 42,737 13,499 65 venarotta ap 42,881 13,493 65 villa celiera pe 42,382 13,860 65 alanno pe 42,294 13,971 60 ascoli piceno ap 42,853 13,578 60 avendita (cascia) pg 42,752 13,050 60 bascianella (colledara) te 42,561 13,694 60 bolognano pe 42,217 13,961 60 brittoli pe 42,316 13,861 60 calascio aq 42,325 13,696 60 canestra (castel sant’angelo) ri 42,394 13,031 60 cappelle sul tavo pe 42,464 14,104 60 caramanico terme pe 42,157 14,003 60 castel di lama ap 42,873 13,707 60 castelnuovo (s. pio delle camere) aq 42,295 13,628 60 castignano ap 42,937 13,622 60 castorano ap 42,898 13,727 60 cesaventre (accumoli) ri 42,661 13,215 60 cittaducale ri 42,386 12,949 60 colli del tronto ap 42,876 13,748 60 colonnella te 42,872 13,866 60 controguerra te 42,855 13,818 60 coppito (l’aquila) aq 42,366 13,344 60 fossa aq 42,296 13,487 60 guardia vomano (notaresco) te 42,636 13,884 60 l'aquila aq 42,356 13,396 60 lucoli aq 42,289 13,350 60 micigliano ri 42,451 13,054 60 montefino te 42,545 13,885 60 morro d'oro te 42,665 13,920 60 navelli aq 42,236 13,729 60 nereto te 42,819 13,817 60 nocciano pe 42,334 13,984 60 norcia pg 42,793 13,094 60 notaresco te 42,659 13,895 60 poggio bustone ri 42,502 12,888 60 roccafluvione ap 42,861 13,475 60 s. omero te 42,788 13,803 60 san demetrio ne` vestini aq 42,288 13,558 60 san valentino in abruzzo citeriore pe 42,233 13,987 60 san vittorino (l'aquila) aq 42,397 13,314 60 sarnano mc 43,035 13,298 60 scafa pe 42,266 14,003 60 scoppito aq 42,372 13,256 60 terracino (accumoli) ri 42,679 13,214 60 tocco da casauria pe 42,213 13,913 60 torano nuovo te 42,825 13,778 60 vestea (civitella casanova) pe 42,388 13,886 60 vicoli pe 42,341 13,898 60 villanuova (accumoli) ri 42,691 13,228 60 cascia pg 42,720 13,014 55 castelvecchio calvisio pe 42,310 13,688 55 castiglione a casauria pe 42,235 13,900 55 cepagatti pe 42,363 14,071 55 citta' sant'angelo pe 42,510 14,060 55 comunanza ap 42,958 13,414 55 concerviano ri 42,322 12,986 55 goriano sicoli aq 42,080 13,775 55 marcetelli ri 42,226 13,046 55 montesilvano pe 42,515 14,151 55 moscufo pe 42,428 14,055 55 offida ap 42,935 13,691 55 palmiano ap 42,899 13,458 55 popoli pe 42,171 13,833 55 pratola peligna pe 42,098 13,875 55 preci pg 42,879 13,039 55 rocca di mezzo aq 42,205 13,521 55 santo stefano di sessanio aq 42,343 13,645 55 spoleto pg 42,732 12,736 55 sulmona aq 42,047 13,928 55 tempera (l’aquila) aq 42,366 13,458 55 turrivalignani pe 42,262 14,029 55 aleggia (amatrice) ri 42,639 13,193 d ancarano te 42,839 13,743 d casteltrione (amatrice) ri 42,624 13,343 d castilenti te 42,534 13,918 d cittareale ri 42,617 13,160 d collegentilesco (amatrice) ri 42,624 13,224 d collepagliuca (amatrice) ri 42,634 13,314 d coronella (cascia) pg 42,637 13,064 d cugnoli pe 42,308 13,933 d cupello (cittareale) ri 42,619 13,157 d faiete (cellino attanasio) te 42,609 13,864 d figino (posta) ri 42,539 13,135 d flamignano (tossicia) te 42,545 13,626 d force ap 42,963 13,491 d forcelle (amatrice) ri 42,644 13,198 d giulianova te 42,753 13,958 d montalto ap 42,988 13,609 d montegallo ap 42,841 13,333 d mosciano s. angelo te 42,750 13,889 d pasciano (amatrice) ri 41,288 13,210 d prato (amatrice) ri 42,634 13,303 d retrosi (amatrice) ri 42,623 13,318 d ripaberarda (castignano) ap 42,923 13,599 d rocchetta (amatrice) ri 42,656 13,287 d ronzano 212 a. tertulliani et al. (castel castagna) te 42.554 13.725 d roseto degli abruzzi te 42,676 14,016 d rotella ap 42,954 13,561 d san giorgio (amatrice) ri 42,634 13,246 d scai (amatrice) ri 42,598 13,231 d silvi te 42,557 14,114 d torrita (amatrice) ri 42,619 13,221 d tortoreto te 42,805 13,914 d vallunga (leonessa) ri 42,580 13,002 d vezzano (cittareale) ri 42,613 13,158 d villa pulcini (leonessa) re 42,596 13,924 d volciano (leonessa) ri 42,581 13,022 d anversa degli abruzzi aq 41,993 13,804 50 avezzano aq 42,033 13,426 50 bugnara aq 42,022 13,862 50 camerano an 43,530 13,551 50 camerino mc 43,135 13,068 50 campello sul clitunno pg 42,820 12,778 50 cannara pg 42,994 12,583 50 cantalice ri 42,466 12,904 50 carsoli aq 42,098 13,084 50 casperia ri 42,338 12,670 50 castelbellino an 43,486 13,145 50 castelnuovo di farfa ri 42,231 12,744 50 chieti ch 42,353 14,169 50 corfinio aq 42,124 13,843 50 fabriano an 43,335 12,905 50 fermo ap 43,160 13,716 50 foligno pg 42,955 12,704 50 forano ri 42,297 12,595 50 gioia dei marsi aq 41,953 13,692 50 labro ri 42,525 12,800 50 macerata mc 43,299 13,452 50 magliano de` marsi aq 42,092 13,363 50 massa martana pg 42,776 12,525 50 matelica mc 43,256 13,009 50 montecassiano mc 43,363 13,436 50 montefalco pg 42,893 12,651 50 morro reatino ri 42,527 12,832 50 nocera umbra pg 43,113 12,788 50 orte vt 42,460 12,385 50 ostra an 43,612 13,158 50 pacentro aq 42,050 13,993 50 pescara pe 42,464 14,214 50 pescina aq 42,025 13,657 50 pettorano sul gizio aq 41,972 13,960 50 piediluco tr 42,536 12,755 50 pineto te 42,608 14,067 50 poggio mirteto ri 42,265 12,686 50 porto civitanova (civitanova marche) mc 43,300 13,733 50 potenza picena mc 43,366 13,621 50 raiano aq 42,102 13,813 50 rieti ri 42,404 12,867 50 ripatransone ap 42,999 13,762 50 rivodutri ri 42,515 12,856 50 rocca di cambio aq 42,235 13,490 50 sant'angelo in pontano mc 43,100 13,398 50 staffolo an 43,432 13,186 50 stimigliano ri 42,299 12,565 50 terni tr 42,561 12,648 50 tione degli abruzzi aq 42,203 13,636 50 toffia ri 42,212 12,752 50 turania ri 42,137 13,009 50 visso mc 42,930 13,088 50 vittorito aq 42,125 13,817 50 agugliano an 43,544 13,388 45 ancona an 43,603 13,507 45 arrone tr 42,583 12,768 45 assisi pg 43,070 12,616 45 farfa (castelnuovo di farfa) ri 42,231 12,744 45 filottrano an 43,434 13,351 45 jesi an 43,522 13,245 45 loreto an 43,439 13,610 45 spello pg 42,992 12,668 45 tolentino mc 43,209 13,283 45 viterbo vt 42,421 12,110 45 barbara an 43,579 13,025 40 bolognola mc 42,993 13,228 40 capistrello aq 41,966 13,391 40 calamari (veroli) fr 41,671 13,487 40 castel colonna an 43,679 13,107 40 citta` di castello pg 43,456 12,239 40 fabro tr 42,863 12,013 40 fano pu 43,837 13,018 40 genga an 43,429 12,935 40 guarcino fr 41,799 13,314 40 mergo an 43,472 13,037 40 monteleone d`orvieto tr 42,917 12,051 40 narni tr 42,517 12,521 40 nespolo ri 42,155 13,070 40 perugia pg 43,106 12,386 40 ripe an 43,671 13,107 40 rocca pia aq 41,932 13,977 40 roma rm 41,895 12,482 40 ronciglione vt 42,291 12,217 40 senigallia an 43,714 13,223 40 subiaco rm 41,925 13,095 40 tuscania vt 42,420 11,869 40 urbino pu 43,726 12,636 40 velletri rm 41,688 12,778 40 scanno aq 41,903 13,881 35 sora fr 41,718 13,613 35 alatri fr 41,726 13,344 30 arpino fr 41,649 13,611 30 ceprano fr 41,544 13,517 30 ferentino fr 41,691 13,254 30 fiuggi fr 41,802 13,224 30 montefiascone vt 42,537 12,030 30 rivisondoli aq 41,870 14,066 30 roccaraso aq 41,847 14,079 30 sarteano si 42,989 11,869 30 chiusi si 43,016 11,948 25 acuto fr 41,791 13,176 20 filettino fr 41,889 13,324 20 frosinone fr 41,635 13,340 20 priverno lt 41,473 13,181 20 alviano tr 42,590 12,297 f amandola ap 42,980 13,357 f attigliano tr 42,515 12,294 f castel di sangro aq 41,784 14,108 f castel gandolfo rm 41,747 12,651 f ficulle tr 42,835 12,066 f monteleone di spoleto pg 42,652 12,953 f orvieto tr 42,719 12,113 f ovindoli aq 42,136 13,516 f palestrina rm 41,836 12,889 f scheggino pg 42,712 12,831 f sellano pg 42,888 12,927 f sigillo ri 42,496 13,081 f todi pg 42,782 12,407 f acquafondata fr 41,544 13,953 nf balsorano aq 41,810 13,561 nf 213studio macrosismico del terremoto del gran sasso ... barrea aq 41,758 13,993 nf calenzano fi 43,861 11,165 nf certaldo fi 43,549 11,041 nf cervaro fr 41,482 13,905 nf chianciano si 43,060 11,832 nf collelongo aq 41,886 13,584 nf empoli fi 43,721 10,947 nf fiesole fi 43,807 11,295 nf finale emilia mo 44,834 11,295 nf latina lt 41,468 12,904 nf pelago fi 43,774 11,504 nf piglio fr 41,829 13,145 nf radicofani si 42,897 11,769 nf rufina fi 43,824 11,486 nf sabaudia lt 41,301 13,027 nf sezze lt 41,500 13,060 nf terelle fr 41,554 13,779 nf terracina lt 41,288 13,233 nf vaglia fi 43,907 11,282 nf vinci fi 43,786 11,926 nf appendice b piano quotato del terremoto dell’8 agosto 1951 (ore 19.56 gmt) località prov lat n lon e i mcs cagnano amiterno aq 42,459 13,232 70 isola del gran sasso d`italia te 42,501 13,661 70 nerito (crognaleto) te 42,547 13,479 70 paganica (l’aquila) aq 42,358 13,473 70 arischia (l’aquila) aq 42,419 13,342 65 barete aq 42,450 13,283 65 barisciano aq 42,325 13,592 65 campli te 42,726 13,686 65 campotosto aq 42,558 13,369 65 canzano te 42,646 13,804 65 capitignano aq 42,52 13,301 65 civita di bagno (l’aquila) aq 42,308 13,445 65 montereale aq 42,522 13,246 65 sassa (l’aquila) aq 42,352 13,299 65 senarica (crognaleto) te 42,547 13,515 65 teramo te 42,659 13,704 65 bellante te 42,743 13,806 60 cascia pg 42,720 13,014 60 cermignano te 42,590 13,794 60 cortino te 42,633 13,543 60 l’aquila aq 42,356 13,396 60 pizzoli aq 42,435 13,303 60 rocca santa maria te 42,661 13,548 60 san vittorino (l’aquila) aq 42,397 13,314 60 amandola ap 42,980 13,357 55 basciano te 42,596 13,740 55 colonnella te 42,872 13,866 55 ferentillo tr 42,620 12,791 55 spinetoli ap 42,888 13,773 55 castelli te 42,489 13,712 d cellino attanasio te 42,586 13,859 d colle paganica (montereale) aq 42,507 13,268 d mascioni (campotosto) aq 42,529 13,347 d poggio cancelli (campotosto) aq 42,561 13,327 d valle castellana te 42,7367 13,499 d alanno pe 42,294 13,971 50 amatrice ri 42,628 13,290 50 antrodoco ri 42,414 13,076 50 ascoli piceno ap 42,853 13,578 50 atri te 42,580 13,978 50 cannara pg 42,994 12,583 50 castilenti te 42,534 13,918 50 cittaducale ri 42,386 12,949 50 fano adriano te 42,552 13,538 50 foligno pg 42,955 12,704 50 montelparo ap 43,018 13,536 50 moscufo pe 42,428 14,055 50 muccia mc 43,081 13,044 50 preci pg 42,879 13,039 50 rivodutri ri 42,515 12,856 50 san demetrio ne' vestini aq 42,288 13,558 50 sulmona aq 42,047 13,928 50 terni tr 42,561 12,648 50 trevi (perugia) pg 42,877 12,746 50 venarotta ap 42,881 13,493 50 castignano ap 42,937 13,622 45 giove (terni) tr 42,509 12,324 45 nespolo ri 42,155 13,070 45 pineto te 42,608 14,067 45 rieti ri 42,404 12,867 45 acquasparta tr 42,690 12,546 40 ancona an 43,603 13,507 40 arrone tr 42,583 12,768 40 campello sul clitunno pg 42,820 12,778 40 castelbellino an 43,486 13,145 40 civitella del tronto te 42,771 13,668 40 falerone ap 43,107 13,472 40 fermo ap 43,160 13,716 40 guardea tr 42,622 12,298 40 lugnano in teverina tr 42,573 12,331 40 macerata mc 43,299 13,452 40 matelica mc 43,256 13,009 40 mompeo (rieti) ri 42,248 12,753 40 monterubbiano ap 43,085 13,716 40 narni tr 42,517 12,521 40 pescara pe 42,464 14,214 40 piedipaterno (vallo di nera) pg 42,769 12,863 40 roma rm 41,895 12,482 40 subiaco rm 41,925 13,095 40 pratola peligna pe 42,098 13,875 35 alatri fr 41,726 13,344 30 assisi pg 43,070 12,616 30 rocca di papa rm 41,760 12,710 30 tuoro sul trasimeno pg 43,208 12,071 25 firenze fi 43,777 11,249 20 vallombrosa (reggello) fi 43,731 11,558 20 avezzano aq 42,033 13,426 f castel del monte aq 42,364 13,727 f fiuggi fr 41,802 13,224 f norcia pg 42,793 13,094 f perugia pg 43,106 12,386 f pilonico materno (perugia) pg 43,035 12,270 f spoleto pg 42,732 12,736 f viterbo vt 42,421 12,110 f 214 ms. ricevuto il 3 ottobre 2006 testo definitivo ricevuto il 23 gennaio 2007 ms. received: october 3, 2006 final text received: january 23, 2007 a. tertulliani et al. impaginato moro aannaalliissii ppaalleeoossiissmmoollooggiicchhee lluunnggoo llaa ffaagglliiaa ddeell mm.. mmaarriinnee ((aallttaa vvaallllee ddeellll’’aatteerrnnoo)):: rriissuullttaattii pprreelliimmiinnaarrii mmaarrccoo mmoorroo11,, vviittttoorriioo bboossii22,, ffaabbrriizziioo ggaallaaddiinnii33,, ppaaoolloo ggaallllii22,, bbiiaaggiioo ggiiaacccciioo33,, ppaaoolloo mmeessssiinnaa33,, aannddrreeaa ssppoossaattoo33 1ingv, istituto nazionale di geofisica e vulcanologia, roma (e-mail: moro@ingv.it) 2ssn, servizio sismico nazionale, roma (e-mail: vittorio.bosi@serviziosismico.it, paolo.galli@serviziosismico.it) 3cnr, istituto di geologia ambientale e geoingegneria, sez. di roma-tor vergata, roma (e-mail: f.galadini@igag.cnr.it, p.messina@igag.cnr.it, b.giaccio@igag.cnr.it, a.sposato@igag.cnr.it) riassunto il versante sudoccidentale del m. marine è caratterizzato da una faglia normale ad andamento nw-se, ritenuta responsabile della formazione del bacino intermontano dell’alto aterno. l’area è stata interessata dal terremoto del 2 febbraio 1703 (me=6.7). nel corso delle indagini per la realizzazione di una "cartografia geologica prototipale" sono state individuate alcune scarpate di faglia poste alla base del m. marine, con direzione wnw-ese, da ricondurre all'attività recente della faglia. l'identificazione delle scarpate di faglia ha suggerito di avviare un'analisi paleosismologica nell'area. in particolare, è stata realizzata una trincea attraverso una delle scarpate. i risultati ottenuti hanno evidenziato l'occorrenza di un minimo di cinque eventi di dislocazione nell’ambito degli ultimi ca. 15.000 anni, il più recente dei quali è probabilmente da legare al terremoto del febbraio 1703, come evidenziato dalla presenza di colluvi storici fagliati e delle evidenze storiche relative agli effetti geologici del terremoto nell'area investigata. gli studi paleosismologici hanno fornito maggiori vincoli sull’ipotesi di associazione tra l’evento del 1703 e la faglia del m. marine. attraverso l’applicazione di relazioni empiriche che legano la magnitudo momento con la lunghezza della faglia e considerando la struttura del m. marine come parte del sistema di faglie di l’aquila (circa 25 km di lunghezza), è possibile ipotizzare che l'attivazione della sorgente, la cui espressione superficiale si manifesta con il sistema menzionato, sia in grado di produrre terremoti con mw prossima a 6.7. abstract paleoseismological analyses along the mt. marine fault (high aterno valley): preliminary results.the south-western side of mt. marine is characterized by a nw-se trending normal fault, which has been responsible for the formation of the alto aterno intermontane basin. this area was affected by the earthquake of 2 february 1703 (me=6.7), which represents the last seismic event of a sequence characterized by two other main earthquakes occurred during january 1703. during investigations aimed at realizing a “prototipe geological map”, some fault scarps (wnw-ese trending), have been recognized at the base of mt. marine; these scarps are related to the recent fault activity. the identification of the fault scarps suggested to perform paleoseismological analyses in the area. a trench was dug across the 10-m-high southernmost scarp. on the basis of the sedimentological and paleoenvironmental characteristics, the stratigraphic sequence recognized within the trench was divided in 4 different complexes, separated by 3 fault zones. the different ages of the defined complexes has been confirmed by the results of the radiocarbon analysis. paleoseismological analyses indicate the occurrence of a minimum of five displacement events within the last 15,000 years; the most recent of these events is probably related to the 2 february 1703 earthquake, as indicated by the displacement of historical colluviums and by the historical information on the geological coseismic effects in the investigated area. displacements observed along the secondary faults of the main fault zones vary between 0.10 and 0.60 m. considering the magnitude (me=6.7) associated with the 2 february 1703 earthquake and on the basis of the empirical relationships between earthquake magnitude and surficial displacement, a maximum displacement per event of about 1 m can be expected. paleoseismological studies provided, therefore, further information about the association between the 1703 seismic event and the mt. marine fault. also the magnitude related to this event (me=6.7) is comparable with the mw (6.7) which can be derived from the equations linking this kind of magnitude with the length of the surficial fault expression of the entire l’aquila fault system (about 25 km). parole chiave: scarpata di faglia, italia centrale, fagliazione superficiale, paleoterremoto, paleosismologia keywords: fault scarp, central italy, surface faulting, paleoearthquake, paleoseismology. il quaternario italian journal of quaternary sciences 1155(2), 2002, 259-270 11.. iinnttrroodduuzziioonnee nell'ambito del progetto per la realizzazione di una "cartografia geologica prototipale" (accordo di programma tra servizi tecnici nazionali, servizio geologico nazionale e consiglio nazionale delle ricerche) sono stati eseguiti rilievi di campagna finalizzati alla definizione dell’assetto geologico evolutivo della zona dell’alta valle dell’aterno. nel corso delle indagini sono state riconosciute alcune scarpate di faglia nella fascia pedemontana del m. marine, con direzione wnw-ese. la formazione di tali scarpate è da ricondurre all'attività recente della faglia che borda, per l'intera lunghezza, il versante sudoccidentale del m. marine. questa ha un andamento medio da nw-se a wnw-ese ed è ritenuta responsabile della formazione del bacino intermontano dell’alto aterno (bosi, 1975; blumetti, 1995; blumetti et al.., 1996; basili et al., 1997; 1999). in questo lavoro vengono descritti i primi risultati ottenuti dallo studio di una trincea paleosismologica scavata attraverso una delle scarpate di faglia menzionate associate alla struttura del m. marine. mediante l’osservazione delle foto aeree, la mappatura e il riconoscimento sul terreno della scarpata, sono stati identifica260 m. moro et al. ti siti potenziali per lo scavo di trincee esplorative. la realizzazione di una trincea paleosismologica ha permesso di determinare la natura tettonica della scarpata; quest’ultima è risultata essere l’espressione superficiale di una faglia diretta parallela al versante di faglia e responsabile della dislocazione di depositi alluvionali, di versante e di coltri colluviali recenti (olocene) (fig. 1). l'analisi condotta ha fornito informazioni sulla cinematica della struttura ed ha permesso il riconoscimento di eventi di dislocazione cosismica recenti. a questo proposito va ricordato che l’area è stata interessata da un terremoto distruttivo il 2 febbraio 1703 (me=6.7, gruppo di lavoro cpti, 1999). inoltre blumetti (1995), in base all’osservazione di dislocazioni di depositi colluviali tardo pleistocenici e delle descrizioni storiche degli effetti indotti sul terreno dal terremoto del 1703, ha ipotizzato l’attivazione della faglia del m. marine proprio in occasione di questo terremoto. dopo l'inquadramento geologico dell'area ed alcune indicazioni sulla sismicità, un ampio capitolo del presente lavoro è dedicato ai vari aspetti connessi all'analisi paleosismologica: dall'individuazione e caratterizzazione della scarpata di faglia, alla realizzazione della trincea, descrizione delle varie unità dislocate individuate, interpretazione in termini stratigrafici e inquadramento cronologico dei singoli eventi di fagliazione individuati. alcune implicazioni dei risultati ottenuti saranno evidenziati nelle conclusioni. figura 1. localizzazione ed inquadramento geologico del sito. 1, sedimenti sabbioso-limosi e coltri colluviali; 2, brecce calcaree di versante; 3, successione carbonatica; 4, scarpate di faglia secondarie; 5, faglia diretta (a) e suo probabile prolungamento (b); i trattini indicano la parte ribassata; 6, sito della trincea. geological framework and location of the site. 1, sandy-silty sediments and colluvial deposits; 2, slope-derived calcareous breccias; 3, carbonate succession; 4, secondary fault scarps; 5, normal fault (a) and its probable extension (b); hatching on downthrown side; 6, trench site. 22.. iinnqquuaaddrraammeennttoo ggeeoollooggiiccoo ddeellll’’aarreeaa l'alta valle del f. aterno è una depressione allungata in direzione nw-se all’interno della dorsale appenninica, nel settore più settentrionale dei rilievi abruzzesi. nel tratto tra barete e arischia la valle si immette in un’ampia depressione in gran parte di origine tettonica, bordata dalla faglia del m. marine, che tende a congiungersi verso sud con la conca aquilana. i rilievi che bordano la valle sono costituiti da rocce calcareo-dolomitiche appartenenti alla successione meso-cenozoica laziale-abruzzese, mentre in prossimità del fondovalle affiorano depositi fluviali e lacustri plio-quaternari terrazzati e depositi clastici di versante; solo nel tratto a nord di s. giovanni, il fondovalle dell’aterno è inciso anche nei depositi silicoclastici miocenici. per quanto riguarda gli studi di tettonica plio-quaternaria, i dati geologici disponibili per quest’area sono riportati in bosi (1975), blumetti (1995), bagnaia et al. (1996), blumetti et. al. (1996), basili et al. (1997), basili et al. (1999), galadini (1999) e galadini & galli (2000). più recentemente, bosi et al. (2000) e moro et al. (2001) hanno realizzato una carta geologica in cui sono rappresentati gli eventi sedimentari ed erosivi occorsi durante il plio-quaternario. dall’analisi delle informazioni contenute nella carta emerge un quadro di evoluzione geologica caratterizzato dalla presenza di almeno nove episodi sedimentari e numerosi eventi erosivi. dal punto di vista dell’assetto strutturale, va evidenziato il fatto che la faglia del m. marine fa parte di un sistema composto da quattro segmenti principali (fig. 1) disposti en-echelon con step-over destro (galadini, 1999; galadini & galli, 2000; galadini & messina, 2001) che si sviluppa tra il bacino di capitignano (a nord dell'area studiata) e la città di l'aquila. nell'ambito dell'intero sistema di faglia, tuttavia, le evidenze più marcate di attività tardo-quaternaria riguardano proprio il segmento di m. marine e quello subito a sud, noto come faglia del m. pettino. il primo ha andamento da nw-se a wnwese e si sviluppa tra gli abitati di marana e arischia, mentre il secondo, con andamento da nw-se ad e-w, termina verso nw tra gli abitati di s. vittorino e s. marco e verso sud a ridosso di l'aquila (fig. 1). entrambe le faglie, ritenute attive nel pleistocene superiore-olocene (bosi, 1975; blumetti, 1995; blumetti et al., 1996; basili et al., 1997; basili et al., 1999; galadini & galli, 2000), sono caratterizzate da evidenti scarpate di faglia in roccia e, spesso, da ampie zone cataclastiche laddove tagliano la serie meso-cenozoica. 33.. ssiissmmiicciittàà ddeellll’’aallttoo aatteerrnnoo le informazioni riguardanti la sismicità storica evidenziano che l'area è stata interessata nel 1703 da una delle più distruttive sequenze sismiche che hanno interessato l’italia peninsulare. la sequenza è caratterizzata da tre eventi principali, di cui l’ultimo (2 febbraio), con epicentro nella zona di l’aquila, è risultato di intensità pari a x mcs (gruppo di lavoro cpti, 1999). la cronologia degli eventi principali (14 gennaio, 16 gennaio, 2 febbraio) e l'ubicazione delle aree epicentrali evidenziano l'attivazione progressiva di sorgenti sismogenetiche in direzione appenninica, da nord verso sud. 261analisi paleosismologiche ... le numerose scosse causarono rilevanti effetti sull'ambiente, descritti da grimaldi (1703), uria de llanos (1703) e parozzani (1887): voragini e spaccature nel terreno, fuoriuscita di materiale infiammato e di gas sulfurei, dissesti di vario tipo e modifiche nell'andamento del corso dei fiumi, formazione di laghi di piccole dimensioni. in particolare, nei dintorni di arischia si formarono due aperture nel terreno dalle quali fuoriuscirono pietre e grandi quantità d'acqua, con formazione di un piccolo bacino idrico. nei monti vicini alla località colle vi fu caduta di massi e si aprirono spaccature nel terreno: in una di queste, lunga circa 3 km (2 miglia), precipitarono anche alcune pecore. a pizzoli è ricordata l'apertura di due fenditure, da una delle quali uscì una grande quantità di materiale roccioso e dell’acqua bianca che aveva formato un laghetto. per quanto riguarda altri terremoti distruttivi, l'informazione storica evidenzia che l'area aquilana è stata interessata da una delle scosse della disastrosa sequenza del 1349 (i pari a ix-x mcs a l'aquila, monachesi & stucchi, 1997). prima di questo evento, tuttavia, l'area aveva già subito il terremoto del 1315, i cui effetti sono, tuttavia, poco noti. successivamente, l'aquila e l'alto aterno sono stati interessati dal terremoto del 1461 e da quello del 1762 (i x e ix rispettivamente a l'aquila) con effetti non paragonabili a quelli dei terremoti del 1349 e del 1703. gli unici dati sismologici strumentali relativi alla sismicità minore dell'alta valle dell'aterno sono stati pubblicati da bagnaia et al. (1996). in tale lavoro sono stati analizzati i dati raccolti, a partire dal 1992, da una rete locale gestita dal servizio sismico nazionale in collaborazione con il dipartimento di fisica dell’università di l’aquila. l’attività sismica risulta concentrata in due sequenze, una nell’agosto del 1992 (mmax = 3.9) e l’altra nel giugno 1994 (mmax = 3.7). lo sciame della prima sequenza è localizzato tra il m. san franco ed il m. stabiata con una concentrazione degli ipocentri all’interno di una stretta fascia tra 8 e 12 km. le soluzioni focali indicano meccanismi dip-slip con piani di faglia a direzione prevalente nw-se ed assi t orientati in direzione antiappenninica, compatibili con il regime tettonico distensivo che caratterizza questo settore dell’appennino centrale. nel 1994 l'area è stata interessata da un secondo sciame con un evento principale, il 2 giugno, di magnitudo pari a 3.7. la distribuzione spaziale degli eventi è concentrata in una fascia adiacente le località di barete, pizzoli e m. marine. secondo bagnaia et al. (1996) gli ipocentri proiettati in direzione e-w interessano volumi focali raggruppati nei primi 15 km di crosta, a profondità tipiche dei terremoti appenninici. 44.. iinnddaaggiinnii ppaalleeoossiissmmoollooggiicchhee 4.1 geomorfologia del sito la scelta del sito della trincea è il frutto di analisi morfologiche eseguite nell’ambito degli studi per la realizzazione di una carta geologica prototipale (bosi et al., 2000; moro et al., 2001). oltre alla scarpata principale, ubicata al piede del versante carbonatico, sono state evidenziate tre ulteriori scarpate di altezza variabile tra 10 e 20 metri (fig. 1). queste scarpate sono state ritenute di origine tettonica in base ai seguenti elementi: 262 non sono riferibili alla successione terrazzata dell’alta valle dell’aterno; non sono riferibili ad attività antropica (i muri a secco osservabili lungo alcuni tratti delle scarpate sono di limitata altezza ed hanno il solo scopo di impedire fenomeni franosi di piccola entità in una zona densamente abitata). l’analisi delle foto aeree ed i rilievi sul terreno lungo le scarpate che interessano i depositi di versante hanno mostrato che in generale questi tre elementi morfologici interessano principalmente aree caratterizzate da erosione durante l’olocene. l’esiguità di affioramenti di depositi olocenici ha consentito di identificare in questa fase due soli siti per lo scavo di trincee esplorative. i siti identificati si localizzano sulla scarpata più meridionale rispetto alle tre riconosciute (fig. 1). in questa area la faglia assume una direzione wnw-ese. nella figura 1 sono riportate le unità affioranti in prossimità del sito paleosismologico. oltre alle formazioni calcareo-dolomitiche presenti sul versante di m. marine, sono state evidenziate due unità riferibili al pleistocene superiore olocene: l’unità 1 è costituita da più livelli sabbioso-limosi e da coltri detritiche provenienti dai soprastanti versanti; comprende inoltre i depositi di due conoidi detritiche (pleistocene sup. olocene). l’unità 2 è costituita da brecce calcaree di versante ben stratificate a cui si intercalano alcuni livelli centimetrici sabbioso-limosi ricchi di materiale organico. le datazioni con il metodo del radiocarbonio eseguite su due di questi livelli hanno fornito età rispettivamente di 31.710±760 e 23.330±300 yr b.p. (galadini & galli, 2000). questa unità è dislocata dal sistema di faglie presenti al piede del versante del m. marine e nel settore ribassato della struttura i depositi non affiorano in quanto ricoperti da unità più recenti. 4.2 aspetti tecnici dell'analisi paleosismologica la trincea è stata scavata trasversalmente alla scarpata di faglia (fig. 2) con direzione n25°e, è lunga circa 28 metri, raggiunge una profondità e larghezza media di 2 metri ed interessa depositi alluvionali, colluviali e di versante. allo scopo di cartografare in dettaglio le pareti della trincea, è stato applicato un reticolo a maglie quadrate di un metro di lato e nelle zone in cui necessitava un maggior dettaglio stratigrafico la larghezza delle maglie è stata portata a 0.5 m di lato. i dati desumibili dalle pareti della trincea sono stati trasferiti su carta millimetrata in scala 1:20. sono state altresì effettuate riprese fotografiche di dettaglio delle pareti con fotocamera digitale, a distanza fissa (circa 1 m) per ogni fotogramma. ciò ha permesso di realizzare un fotomosaico delle pareti, grazie alla retrodeformazione delle immagini vincolata dalla geometria del reticolo. l’età dei paleoeventi è stata vincolata sulla base di datazioni radiometriche 14c effettuate su campioni prelevati dalle unità stratigrafiche. le datazioni sono state eseguite presso il laboratorio beta analytic inc. (miami-florida). le età convenzionali sono state calibrate da beta analytic utilizzando il database intcal98 di cui in stuiver et al. (1998). la conoscenza dei processi deposizionali ed erosivi, relativi all’evoluzione geologica del pleistocene superiore-olocene in questo settore appenninico, ha permesso di definire una cronologia relativa per i comm. moro et al. figura 2. veduta panoramica del sito paleosismologico. le linee a tratteggio indicano la parte superiore ed inferiore della scarpata di faglia. le frecce mostrano l’andamento in superficie della scarpata. view of the paleoseismological site. dashed lines indicate the top and the bottom of the fault scarp. arrows shows the superficial pattern of the scarp. 263 plessi sedimentari riconosciuti. come mostrato nel seguito, ciò ha consentito di superare alcune difficoltà legate alla definizione di vincoli cronologici mediante datazioni quantitative. 4.3 contesto stratigrafico e misure radiocarboniche nell’ambito della successione indagata sono state riconosciute 10 unità distinte sulla base dei principali caratteri lito-pedostratigrafici e del loro significato sedimentologico-paleoambientale (tab. 1). i rapporti stratigrafico-tettonici esistenti fra le unità attraversate dalla trincea permettono, inoltre, di suddividere l’intera successione in quattro principali complessi (fig. 3). i principali elementi di discontinuità stratigrafica che consentono una simile suddivisione sono rappresentati dalle tre zone di deformazione a, b e c (fig. 3, 4, 5, 6 e 7). i quattro gruppi di unità, che attraverso tali elementi vengono a contatto fra loro, non mostrano infatti alcun tipo di affinità sedimentologico-stratigrafica; essi pertanto possono essere trattati come complessi discreti stratigraficamente e cronologicamente ben distinti gli uni dagli altri. tale suddivisione è corroborata dalla cronologia radiocarbonica disponibile riportata in tab. 2. 4.3.1 indizi cronologici forniti dal contesto stratigrafico-paleoambientale sebbene in ambito paleosismologico le misure cronometriche siano un requisito essenziale, esse in ogni caso costituiscono solo una parte del complesso di dati necessari per la definizione di una precisa cronologia della sequenza stratigrafica e degli eventi paleosismici riconosciuti. nel caso in esame, il riconoscimento di alcuni elementi di potenziale valenza tefrocronologica nonché l’analisi dell’evoluzione stratigrafico-paleoambientale della successione indagata permettono di migliorare e ridefinire il quadro cronologico fornito dalle misure radiocarboniche. per quanto concerne la parte più antica della successione (complesso 1 fig. 3 e 5), l’elemento più significativo ai fini cronologici è senza dubbio rappresentato dalla sequenza costituita dal tephra ridepositato (unità 8a e 8b) e dal paleosuolo che ne interessa il tetto (unità 7a) la cui frazione organica ha fornito un’età di 30.110±310 yr 14c b.p. la componente vulcanica del tephra rimaneggiato è costituita in larga misura (>90%) analisi paleosismologiche ... figura 3. riproduzione grafica e fotomosaico della parete ovest della trincea. sono indicate con i riquadri a tratteggio le tre zone principali di deformazione a,b,c. le unità stratigrafiche così come le zone principali di faglia vengono descritte nel testo. le faglie sono indicate in nero nello schema grafico ed a tratteggio bianco nel fotomosaico. sketch and photomosaic of the western trench wall. dashed squares indicate the three principal deformation zones a,b,c. stratigraphic units and the principal fault zones are described in the text. faults are indicated with black lines in the sketch and with white dashed lines in the photomosaic. 264 da ceneri molto sottili, dal tipico colore giallastro assunto dai vetri in seguito ad un processo di alterazione, mentre la frazione psammitica si compone di vetro grigio ben vescicolato associato a fenocristalli di mica, pirosseno e plagioclasio in abito discretamente conservato. il paleosuolo limoso, si presenta ben sviluppato (spessore 70-100 cm) con un orizzonte b bruno-nerastro (7,5yr3/2) che, tramite un orizzonte nodulare discontinuo, sfuma gradualmente in c. entrambi gli orizzonti b e c sono ben distinti e rappresentati, mentre l’orizzonte a, troncato al tetto da una superficie di erosione, affiora solo in lembi residui. a completamento di quanto ossservato, va ricordato che a meno di un chilometro ad est della trincea, nell’abitato di frattole, blumetti (1995) ha descritto una sequenza di depositi quaternari recenti interessata da un fitto e complesso sistema di faglie dirette. questa successione presenta nella parte alta un paleosuolo, sviluppato su tephra giallastro, che ha fornito un’età di 29.690±1110 yr 14c b.p. del tutto simile a quella del paleosuolo rinvenuto nella trincea paleosismologica (in seguito pt). un esame delle caratteristiche mineralogico-sedimentologiche del livello pedogenizzato e del parent material del paleosuolo di frattole (in seguito pf) hanno inoltre evidenziato forti analogie lito-pedostratigrafiche fra i due paleosuoli che, in aggiunta ai dati cronometrici, ne confermano la correlazione. sui rilievi carbonatici dell’appennino centrale è stato identificato, in diversi contesti deposizionali subaerei, un pedomarker tardopleistocenico sviluppatosi su un tephra rimaneggiato correlato all’ignimbrite campana (frezzotti & narcisi, 1996). il paleosuolo è classificato come un andosuolo sviluppatosi sotto condizioni climatiche temperato umide, evolutosi a luvisol in seguito ad m. moro et al. tabella 1. descrizione litostratigrafica, interpretazione sedimentologica e cronologia della trincea marruci 1. lithostratigraphic description, sedimentological interpretation and chronology of the marruci 1 trench. unità liv. descrizione interpretazione misure 14c età (ky bp) 10 a-c ghiaie grossolane caotiche con elementi eterometrici e poco elaborati in scarsa sedimenti alluvionali matrice sabbiosa. verso l’alto le ghiaie passano a livelli decimetrici di sabbie fini. 9 a-e ghiaie stratificate (clast-supported) con elementi calcarei subarrotondati passanti sedimenti alluvionali >39,3 verso l’alto a sabbie fini interessate da patine manganesifere. 8 a-b sabbie fini e silt giallastro a prevalente componente vulcanica con intercalazioni tephra rimaneggiato 39,3÷37,81 di ghiaie (8a) in strati decimetrici lenticolari. dell’ignimbrite campana 7 a limo bruno-giallastro a prevalente componente vulcanica. orizzonte b/c di alterazione 37,8÷341 pedogenetica b limo bruno-nerastro (7,5 yr3/2) con abbondante materiale organico, incrostazioni orizzonte b di alterazione 30.310±310 e noduli calcarei . pedogenetica erosione 6 limo sabbioso bruno-nerastro con rari clasti calcarei. colluvio del sottostante <34 paleosuolo (7) 5 a-f alternanze di ghiaie ben stratificate ed embriciatie e sabbie in livelli decimetrici e sedimenti alluvionali 33.580±270 geometria lenticolare e cuneiforme. 4 a-f ghiaie calcaree eterometriche e massive ad elementi subangolosi corrosi, a luoghi depositi di versante 24÷18 stratificate in livelli decimetrici con rari intervalli sabbiosi. 3 a-g ghiaie grossolane mal stratificate con abbondante matrice limosa ed intercalazioni sedimenti 21.090±280 <24 decimetriche di limo sabbioso. alluvio-colluviali >16 2 f-e limi sabbiosi bruno-giallastri amalgamati, mal stratificati con elementi calcarei sedimenti colluviali 12.930±260 <16 eterometrici. 2 a-c limi sabbiosi amalgamati, mal stratificati con rari elementi calcarei eterometrici e sedimenti colluviali 3880±70 <22 frammenti di laterizi di età storica (2c-2a). 1 limo sabbioso bruno suolo attuale 1giaccio et al., 2002; giaccio & isaia submitted; 2età desunta dal contenuto archeologico. tabella 2. età 14c dei campioni prelevati in trincea ottenute sulla base di datazioni radiometriche calibrate e dendrocorrette. la localizzazione dei campioni è riportata in figg. 4, 5, 6, e 7 (esclusi i campioni piz4 e piz7, non rappresentati nel log della trincea). l’intervallo 2σ è dato secondo il programma di calibratura del radiocarbonio di stuiver et al. (1998). measured and dendrochronologically calibrated 14c age of samples collected in the trench. sample location and age are shown in figures 4, 5, 6 and 7 (except for sample piz4 and piz7, which is out of the log of trench). the 2σ interval is given according to the radiocarbon calibration program of stuiver et al. (1998). camp. comp. unità liv. materiale datato cod. lab. tecnica età 14c bp 2σ età cal. bp piz4 1 7 a paleosuolo beta-167950 radiometrica 30.110 310 ~35.0902; ~34.1003 piz3 1 5 e carbone beta-167949 ams 33.580 270 ~38.9002; ~37.4003 piz7 3 3 e silt colluviale beta-167951 radiometrica 21.090 280 ~24.8002; ~24.0003 piz10 4 2 e silt colluviale beta-167952 radiometrica 12.930 260 16.160-14.3401 piz14 4 2 y silt colluviale beta-167953 radiometrica 3890 60 4500-4480/4440-41501 piz12 4 2 a silt colluviale beta-169188 radiometrica 3880 70 4520-4140/4120-41001 1stuiver et al., 1998; 2 bard, 1998; 3voelker et al., 2000 (2 -3calibrazione stimata). 265analisi paleosismologiche ... un successivo peggioramento climatico in senso freddoarido (frezzotti & narcisi, 1996). con l’eccezione di una singola datazione a 38.770±2100 14c yr b.p., numerose misure radiocarboniche indicherebbero che questo pedomarker appenninico (in seguito pma) si sia sviluppato nell’intervallo cronologico di 33.000-29.000 yr 14c b.p. (frezzotti & narcisi, 1996 con riferimenti). le età di 29.690±1110 e di 30.110±310 yr 14c b.p., rispettivamente del pf e del pt, si sovrappongono ampiamente alle misure radiocarboniche attualmente disponibili per il pma suggerendo pertanto una loro correlazione. le più recenti datazioni dei depositi prossimali terrestri dell’ignimbrite campana (in seguito ic), hanno fornito un’età di 39.280±110 yr b.p., ottenuta da 18 misure 40ar/39ar (de vivo et al., 2001), mentre la risedimentazione del tephra (unità 8) e la sua successiva pedogenesi (unità 7) sono state correlate rispettivamente all’heinrich event 4 (ca. 39.300÷37.800 cal yr b.p.) e agli interstadi 8-7 (ca. 37.500÷34.000 cal yr b.p.) della stratigrafia isotopica groenlandese (giaccio et al., 2002; giaccio & isaia, 2002). tramite le zone di deformazione b e c, rappresentate rispettivamente da un sistema di faglie normali e da una faglia diretta antitetica del sistema del m. marine, il complesso 1 è messo a contatto con i più recenti depositi dei complessi 2 e 3 (fig. 3, 5 e 6). i depositi del complesso 2 (unità 4a-f) evidenziano un netto cambiamento di facies rispetto alla sequenza del complesso 1. si tratta di ghiaie calcaree massive mal stratificate e mal classate ad elementi subangolari con scarsa matrice sabbiosa totalmente priva di componente organica e/o di sedimenti di suolo così frequenti nei livelli sottostanti. essi, per la posizione stratigrafica che occupano e le caratteristiche di facies che li contraddistinguono, possono essere dubitativamente correlati alle fasi di gelifrazione e sedimentazione detritica di versante dell’ultimo massimo glaciale ampiamente documentate in appennino centrale fra 21.000 e 18.000 14c yr b.p. (giraudi & frezzotti, 1997). il complesso 3 (unità 3a-g) è invece costituito da alternanze di livelli ghiaiosi e sabbioso-limosi presumibilmente riferibili a processi di sedimentazione alluvionale e colluviale. la frazione organica di un campione di sabbie-limose colluviali (livello 3e) di questo complesso ha fornito l’età di 21.090±280 14c yr b.p. considerando la natura colluviale del materiale datato, per questi sedimenti tale data va intesa come termine post quem per la sedimentazione, mentre si può assumere come età minima la data di 12.930±280 14c yr b.p. della base del complesso 4 riferibile all’intervallo tardiglaciale-olocene recente. l’attribuzione a tale ambito cronologico è suggerita sia dai dati cronometrici (tab. 1) sia dall’evidenza stratigrafica di numerosi frammenti laterizi fluitati di età storica (rolfo, com. pers.) distribuiti nella parte alta della sequenza (livelli 2a-c). la serie tardiglaciale-olocenica si compone di sedimenti colluviali amalgamati e malstratificati, tali da rendere piuttosto arbitraria una precisa individuazione dei limiti di base e tetto delle quattro unità riconosciute che rappresentano, in ogni caso, altrettanti distinti episodi colluviali. nell’ambito di territori caratterizzati da una costante occupazione umana storico-protostorica associata ad una massiccia attività agricolo-pastorale, quale è certamente il caso in esame, è estremamente critica la distinzione degli effetti geologico-ambientali dovuti all’impatto antropico da quelli ascrivibili alle oscillazioni climatiche oloceniche. studi stratigrafici ad alta risoluzione hanno in ogni caso evidenziato un comportamento ciclico del clima olocenico con un periodo di circa 1500±500 yr (bond et al., 1997; mayewski et al., 1997; bond et al., 2001). nell’ambito di questa ciclicità, nel periodo storico (ultimi 2500) si sarebbero verificati due episodi principali di raffreddamento centrati, rispettivamente, intorno a 1400 e 350 yr b.p. che corrispondono a due fasi di dissesto ambientale ben documentate nel territorio italiano (es. cremaschi & gasperi, 1989; ortolani & pagliuca, figura 4. riproduzione grafica della zona di deformazione a della parete ovest della trincea. le unità stratigrafiche e le deformazioni vengono descritte all’interno del testo. le frecce rappresentano gli orizzonti evento relativi agli eventi di dislocazione riconosciuti. sketch of the deformation zone a of the western trench wall. stratigraphic units and deformation zones are described in the text. arrows represent the event horizons related to the recognized displacement events. 266 m. moro et al. figura 5. riproduzione grafica della zona di deformazione b della parete ovest della trincea. le unità stratigrafiche e le deformazioni vengono descritte all’interno del testo. le frecce rappresentano gli orizzonti evento relativi agli eventi di dislocazione riconosciuti. sketch of the deformation zone b of the western trench wall. stratigraphic units and deformation zones are described in the text. arrows represent the event horizons related to the recognized displacement events. 1994; veggiani, 1995; antonioli et al., 2000; giraudi, in stampa ). a questi periodi, noti nella letteratura della climatologia storica come la “fase dei dissesti alto medievali” e la “piccola età glaciale”, sono associati episodi di intensa erosione di suoli e accumulo di sedimenti colluviali . alla luce di quanto precede, e considerando la criticità interpretativa delle misure cronometriche ottenute dai sedimenti colluviali di questo complesso, è possibile correlare dubitativamente la parte alta delle unità oloceniche, contenenti laterizi storici, ad una fra le due ultime fasi di instabilità ambientale dell’alto medioevo e della piccola età glaciale. 4.4 deformazioni osservate ed eventi di dislocazione cosismica riconosciuti i rapporti tra le unità stratigrafiche ed i vari piani di taglio esposti in entrambe le pareti dello scavo hanno portato al riconoscimento delle tre zone di deformazione principali indicate in figura 3 e citate nel paragrafo precedente. le zone sono composte da sistemi più o meno complessi di faglie prevalentemente dirette, ad alto angolo, con orientamento wnw-ese, che ribassano il settore sudoccidentale (tranne la faglia f6 che ribassa il settore settentrionale). le relazioni tra unità stratigrafiche e piani di taglio hanno permesso di riconoscere l'occorrenza di almeno cinque eventi di fagliazione superficiale. la zona di deformazione a (fig. 3, 4 e 7) risulta ampia circa 2 m; è composta da una serie di faglie dirette ad alto angolo (f2) con locale movimento inverso (f1) e mette a contatto due differenti sequenze stratigrafiche (complesso 3 e 4). la sequenza delle unità 2 (da 2c a 2f) risulta costituita da corpi colluviali massivi recenti (presenza al loro interno di frammenti di ceramica storica) mentre la sequenza 3 è rappresentata da depositi alluvio-colluviali mal stratificati che potrebbero costituire il prodotto della rielaborazione delle unità alluvionali più antiche 5-10 (complesso 1). la faglia è sigillata dall’unità 2a che poggia indisturbata sulle sequenze sottostanti. la zona di deformazione b (fig. 3 e 5) presenta un'ampiezza di circa 5 m e risulta costituita da una serie di faglie normali ad alto angolo localmente con movimento inverso. la faglia principale (f5) mette a contatto la sequenza stratigrafica 3 (complesso 3) con la 5-10 (complesso 1), costituita prevalentemente da depositi fluviali a diverso grado di energia deposizionale, con stratificazione suborizzontale, riferibili ad un livello di base antico non corrispondente con l'attuale. tale faglia disloca l’intera sequenza stratigrafica fino alla base del suolo attuale. la struttura f4 che interessa la sequenza 3 presenta una diminuzione dell’entità del rigetto verticale procedendo verso la porzione superiore della sequenza, ad indicare una riattivazione della struttura. in particolare la base dell’unità 3e ed il tetto dell’unità 3c risultano dislocati rispettivamente di circa 0,50 m e 0,30 m. le faglie che interessano la sequenza 5-10 presentano una entità del rigetto costante e tagliano l’intera sequenza fino alla base del suolo attuale mostrando un rigetto massimo osservabile di circa 0,60 m. la zona di deformazione c (fig. 3 e 6) risulta ampia circa 3 m ed è composta da strutture antitetiche e da strutture a movimento inverso. la faglia antitetica f6 mette a contatto i depositi detritici di versante della sequenza 4 (complesso 2) con la sequenza 5-10 (complesso 1) ed è sigillata dal suolo attuale. nella parete est uno degli ultimi livelli dislocati presenta al suo interno un frammento di ceramica storica. sono presenti altre strutture a componente inversa che mostrano rigetti di 0,1-0,15 m. in tutta la trincea si osservano inoltre strutture e fratture secondarie con rigetti minimi o nulli. l’analisi delle sequenze sedimentarie unitamente allo studio delle strutture deformative ha permesso di identificare le evidenze geologiche di almeno cinque eventi di dislocazione cosismica. l’evento più recente (e1) è desumibile dalla dislocazione, nella zona a, dell’intera sequenza stratigrafica fino alla base dell’unità 2a; la dislocazione riguarda unità recenti che contengono frammenti di ceramica storica. nelle zone b e c tutte le unità sono dislocate, ad 267analisi paleosismologiche ... figura 6. riproduzione grafica della zona di deformazione c della parete ovest della trincea. le unità stratigrafiche e le deformazioni vengono descritte all’interno del testo. le frecce rappresentano gli orizzonti evento relativi agli eventi di dislocazione riconosciuti. sketch of the deformation zone c of the western trench wall. stratigraphic units and deformation zones are described in the text. arrows represent the event horizons related to the recognized displacement events. eccezione del suolo attuale. l'evento e1 ha causato la formazione di una scarpata la cui degradazione ha alimentato la deposizione del cuneo colluviale 2b e successivamente 2a, osservabile nella zona a delle pareti. anche nella zona c, così come nella zona a, la dislocazione interessa un livello contenente manufatti storici. tale evento ha prodotto un progressivo ribassamento verso s delle sequenze stratigrafiche. l’entità minima del rigetto calcolata per questo evento è risultata di 0,3 m, considerando la dislocazione dell’unità 2d (fig. 7). nonostante l'analisi col metodo del radiocarbonio dei depositi fagliati (unità 2y) e di quelli sigillanti (2a) fornisca età piuttosto antiche (vedi tabella 2), la presenza di ceramica storica garantisce che tali livelli siano il frutto di colluviamento da riferire ad una fra le due più recenti fasi di instabilità climatica; la deposizione sarebbe pertanto da riferire o all’alto medioevo o alla piccola età glaciale, come detto in precedenza. questa osservazione, unita alle evidenze storiche sugli effetti geologici del terremoto del 2 febbraio 1703, alla localizzazione dell’epicentro e all’intensità di questo evento sismico, permette di associare ad esso l'evento di dislocazione e1. un ulteriore evento (e2) è riconoscibile nella zona a della parete est (fig. 7), a causa della presenza di un probabile cuneo colluviale (unità 2d), che dovrebbe rappresentare il prodotto dello smantellamento di una scarpata di faglia prodottasi durante e2. il cuneo colluviale (unità 2d) verrà successivamente fagliato dall’evento e1, più recente, descritto in precedenza. nella parete est, in corrispondenza della faglia f3 268 m. moro et al. figura 7. riproduzione grafica della zona di deformazione a della parete est della trincea. le unità stratigrafiche e le deformazioni vengono descritte all’interno del testo. le frecce rappresentano gli orizzonti evento relativi agli eventi di dislocazione riconosciuti. sketch of the deformation zone a of the eastern trench wall. stratigraphic units and deformation zones are described into the text. arrows represent the event horizons related to the recognized displacement events. (fig. 7), è possibile riconoscere altri due eventi: il più recente (e3) disloca la parte basale dell’unità 3a (f4 di fig. 5 e f3 di fig. 7), producendo un rigetto di circa 0,30 m; l’evento più antico (e4) interessa l’intera successione 3 fino al tetto dell’unità 3b, con l’unità 3a che ne sigilla il piano di faglia. in base alle considerazioni riportate nel paragrafo 4.3.1, si ipotizza che la porzione superiore del complesso 3 sia riferibile all’intervallo di tempo 15.00012.000 b.p.; l’età di questi due ultimi eventi è quindi attribuibile al periodo tardiglaciale. l’evento più antico (e5) è riconoscibile nella zona b (parete ovest) sulla struttura f4 (fig. 5), a causa dell’aumento del rigetto tra le unità 3c e 3e, che passa da circa 0,30 m a 0,50 m. l’età del campione piz 7 relativo all’unità 3e è risultata di 21.090±280 yr bp; considerando la natura colluviale di tali depositi, l’età di sedimentazione di tale livello potrebbe essere ringiovanita come detto nel capitolo 4.3.1, fino a circa 12.930±280 yr b.p. l’evento riconosciuto sarebbe quindi databile al periodo tardiglaciale (15.000-12.000 b.p.). la mancanza di correlazioni stratigrafiche fra i vari complessi sedimentari non consente di individuare il rigetto complessivo degli eventi individuati. 55.. ccoonncclluussiioonnii l'identificazione di scarpate di faglia formatesi con l'attività recente (pleistocene superiore-olocene) della faglia del m. marine ha suggerito di approfondire le caratteristiche di tale attività mediante analisi paleosismologica. la scarpata attraverso la quale è stata realizzata la trincea paleosismologica si è formata a causa dei movimenti ripetuti di alcuni piani di faglia che costituiscono parte dell'espressione superficiale della struttura del m. marine. l'analisi paleosismologica ha evidenziato l'occorrenza di eventi di dislocazione nel pleistocene superiore e nell'olocene. in particolare la trincea ha esposto evidenze relative a cinque eventi nell'ambito degli ultimi 15.000 anni. il più recente di tali eventi è da riferire con molta probabilità al terremoto del 2 febbraio 1703, come evidenziato dalla fagliazione di colluvi storici e dalle informazioni storiche sugli effetti geologici del terremoto. le dislocazioni osservate lungo le singole faglie presentano rigetti variabili tra 0,10 e 0,60 m; tali valori, alla luce delle osservazioni sulle deformazioni prodotte dall’ultimo evento (e1), potrebbero rappresentare un minimo se si ipotizza la riattivazione contemporanea dei vari piani di faglia durante un singolo evento sismico. nel complesso, l'analisi paleosismologica ha fornito vincoli geologici più affidabili riguardo l’ipotesi di associazione tra l’evento del 1703 e la faglia del m. marine, sebbene i risultati esposti abbiano carattere preliminare e si attenda la realizzazione di ulteriori scavi nell'area indagata. attraverso l’applicazione di relazioni empiriche che legano la magnitudo momento con la lunghezza della faglia (wells & coppersmith, 1994), e considerando la struttura del m. marine come parte del sistema di faglie di l’aquila (circa 25 km di lunghezza) (galadini & messina, 2001), è possibile ipotizzare che il sistema sia in grado di produrre terremoti con magnitudo prossima a 6.7. il riconoscimento di evidenze di deformazione legate con molta probabilità all’evento sismico del 2 febbraio 1703 (me = 6.7) permette di definire per la faglia del m. marine un tempo intercorso dall'ultimo evento di fagliazione di superficie piuttosto ridotto (dell'ordine dei 300 anni). considerando i dati disponibili sui tempi di ritorno delle faglie appenniniche (in genere superiori al millennio, si veda galadini & galli, 2000, per una sintesi sull'argomento), le valutazioni relative al m.marine definiscono una scarsa probabilità di attivazione in un futuro di interesse sociale. infine, l'individuazione di cinque eventi di dislocazione negli ultimi ca. 15.000 anni, sebbene la sequenza dislocativa sia probabilmente incompleta, è congruente con le indicazioni finora acquisite sui lunghi tempi di ritorno che caratterizzano le faglie appenniniche. rriinnggrraazziiaammeennttii il lavoro è stato parzialmente finanziato dal programma cnr agenzia 2000 “strutture attive nel sistema orogenico appenninico: caratterizzazione geomorfologica, geologico-strutturale, sismogenetica e geodetica”. a. cittadini ha partecipato alle attività di rilievo paleosismologiche. m. rolfo ha effettuato determinazioni archeologiche su frammenti ceramici. si ringrazia c. giraudi per le utili discussioni sulla stratigrafia delle unità riconosciute sulle pareti della trincea. si ringrazia infine f. cococcia per l’aiuto logistico fornito. bbiibblliiooggrraaffiiaa antonioli f., baroni c., camuffo d., carrara c., cremaschi m., frisia s., giraudi c., improta s., magri d., margottini c., orombelli g. & silenzi s. (2000) le fluttuazione del clima nel corso dell’olocene: stato dell’arte. il quaternario, 1133 (1/2), 95128. bagnaia r., blumetti a.m., de luca g., gorini a., marcucci s., marsan p., milana g., salvucci r. & zambonelli e. (1996) morfotettonica dei rilievi a nord della conca aquilana. il quaternario, 99(1), 287-292. bard e. (1998) geochemical and geophysical implications of the radiocarbon calibration. geochimica et cosmochimica acta 6622, 2025-2038. basili r., bosi c. & messina p. (1997) la tettonica quaternaria dell ’alta valle del f. aterno (appennino centrale) desunta dall’analisi di successioni di superfici relitte. il quaternario, 1100(2), 621-624. basili r., bosi c. & messina p. (1999) paleo-landsurfaces and tectonics in the upper aterno valley (central apennines). z. geomorph. n.f., suppl.bd. 111188, 17-25 bond g., showers w., cheseby m., lotti r., almasi p., demenocal p., prior, p., cullen h., hajdas i. & bonani g. (1997) a pervasive millennial-scale cycle in north atlantic holocene and glacial climate. science, 227788, 1257-1266. bond g., kromer b., beer j., muscheler r., evans m.n., showers w., hoffmann s., lotti-bond r., hajdas i. & bonani g. (2001) persistent solar influence on north atlantic climate during the holocene. 269analisi paleosismologiche ... science, 229944, 2130-2136. blumetti a.m. (1995) neotectonic investigations and evidence of paleoseismicity in the epicentral area of the january-february 1703, central italy, earthquakes. in “perspectives in paleoseismology” (l. serva, ed.). association of engineering geologist, special pubblication, 66, 83-100. blumetti, a.m., cavinato, g.p. & tallini m. (1996) evoluzione plio-quaternaria della conca di l 'aquila-scoppito: studio preliminare. i l quaternario, 99(1), 281-286. bosi c. (1975) osservazioni preliminari su faglie probabilmente attive nell’appennino centrale. boll. soc. geol. it., 9944, 827-859. bosi c., messina p. & moro m. (2000) carta geologica prototipale del quaternario dell ’alta valle dell’aterno (aq). incontro di studio “progetto carte prototipale”. bologna 27-28 gennaio 2000, 20 cremaschi m., gasperi g. (1989) l’alluvione altomedioevale di modena in rapporto alle variazioni climatiche oloceniche. mem. soc. geol. 4422, 179-190. de vivo b., rolandi g., gans p.b., calvert a., bohrson w.a., spera f.j. & belkin h.e. (2001) new constraints on the pyroclastic eruptive history of the campanian volcanic plain (italy). mineralogy and petrology, 7733, 47-65. frezzotti m. & narcisi b. (1996) late quaternary tephra-derived paleosols in central italy’s carbonate apennine range: stratigraphical and paleoclimatological implications. quaternary international, 3436, 147-153. galadini f. (1999) pleistocene change in the central apennine fault kinematics, a key to decipher active tectonics in central italy. tectonics, 1188, 877-894. galadini f. & galli p. (2000) active tectonics in the central apennines (italy) – input data for seismic hazard assessment. natural hazard, 2222, 225-270. galadini f. & messina p. (2001) plio-quaternary changes of the normal fault architecture in the central apennines (italy). geodinamica acta, 1144, 321-334 giaccio b., fedele f.g., rolfo m.f., galadini f., messina p. & sposato a. (2002) rapid, synchronous geoenvironmental and human responses to the heinrich event 3 in the central apennines: new evidence from the colfiorito plain (central italy). geophysical research abstract 44, egs02-a-04258. giaccio b. & isaia r. (2002) the campanian ignimbrite position in terrestrial and marine mediterranean successions and greenland icecore: implications for paleoclimatic reconstructions of the mid to high latitude ois 3. geophysical research abstract, 44, egs02-a-04515. giaccio b. & isaia r. (submitted) the campanian ignimbrite position (~39,300 yr b.p.) in greenland gisp2 ice-core and mediterranean europe successions: implications for late pleistocene chronology, climate and cultural change. quaternary science reviews. giraudi c. & frezzotti m. (1997) late pleistocene glacial events in the central apennines, italy. quaternary research 4488, 280-290. giraudi c. (in stampa) le oscillazioni del ghiacciaio del calderone (gran sasso, abruzzo – italia centrale) e le variazioni climatiche degli ultimi 3000 anni. il quaternario. grimaldi f. a. (1703) de novo et ingenti in universa provincia umbriae et aprutii citeriosis terremotu: typis a. sambuchi, todi. gruppo di lavoro cpti (1999) catalogo parametrico dei terremoti italiani. ing, gndt, sga, ssn. bologna 1999, 92 pp. mayewski p.a., meeker l.d., twickler m.s., whitlow s., yang q., berry lyons w. & prentice m. (1997) major features and forcing of high-latitude northern hemisphere atmospheric circulation using a 110,000-years-long glaciochemical series. journal of geophysical research 110022, (c12), 26,34526,366. monachesi g. & stucchi m. (1997) dom4.1, un data base di osservazioni macrosismiche di terremoti di area italiana al di sopra della soglia di danno. gndt, rapporto tecnico, milano. internet: http://emidius.itim.mi.cnr.it/dom/home.html moro m., bosi c. & messina p. (2001) a prototipe geological map of the quaternary of the upper aterno valley (central italy). the stephan mueller topical conference of the european geophysical society, quantitative neotectonics and seismic hazard assessment: new integrated approaches for environmental management, balatonfüred (ungheria), 22-26 settembre 2001. sessione poster, 42. ortolani f. & pagliuca s. (1994) variazioni climatiche e crisi dell’ambiente antropizzato. il quaternario, 77(1), 351-356. parozzani g. (1887) notizie intorno al terremoto del 2 febbraio 1703 ricavate dai manoscritti antinoriani precedute da alcune notizie intorno agli attuali terremoti, tip. b. vecchioni, l'aquila. stuiver m., reimer p.j., bard e., beck j.w., burr g.s., hughen k.a., kromer b., mccormac g., van der plicht j. & spurk m. (1998) intcal98 radiocarbon age calibration, 24,000-0 cal bp. radiocarbon, 4400, 1041-1083. uria de llanos a. (1703) relazione overo itinerario fatto dall'auditore d. alfonso uria de llanos per riconoscere li danni causati dalli passati terremoti seguiti li 14 gennaro e 2 febraro mdcciii con il numero de' morti, e ferit i nella provincia dell'aquila, e tutti li luoghi circonvicini per darne di essi distinta notizia al signor vice ré di napoli. stamperia gaetano zenobj, roma. veggiani a. (1995) i deterioramenti climatici dell’età del ferro e dell’alto medioevo. in torricelliana, faenza, 1995. voelker a.h.l., grootes p.m., nedeau m.-j. & sarnthein m. (2000) radiocarbon levels in the iceland sea from 25-53 kyr and their link to the magnetic field intensity. radiocarbon, 4422, 437-452. wells, d., & coppersmith k., (1994) new empirical relationships among magnitude, rupture length, rupture width, rupture area and surface displacement. bull. seismol. soc. am., 8844, 974– 1002. 270 m. moro et al. ms. ricevuto il 27 novembre 2002 testo definitivo ricevuto il 20 gennaio 2003 ms. received: november 27, 2002 final text received: january 20, 2003 imp.giaccio& la risposta ambientale ed umana alle oscillazioni climatiche sub-orbitali dell’ois3: evidenze geoarcheologiche dalla piana di colfiorito (appennino centrale) biagio giaccio1, mario federico rolfo2, simone bozzato2, fabrizio galadini1, paolo messina1, mara silvestrini3 & andrea sposato1 1cnr, istituto di geologia ambientale e geoingegneria, sezione roma “tor vergata” 2dipartimento di storia, università di roma “tor vergata” 3soprintendenza archeologica per le marche, ancona biagio.giaccio@igag.cnr.it riassunto: giaggio b. et al., la risposta ambientale ed umana alle oscillazioni climatiche sub-orbitali dell’ois3: evidenze geoarcheologiche dalla piana di colfiorito (appennino centrale). (it issn 0394-3356, 2004). un ampia trincea ha permesso di investigare una successione stratigrafica del pleistocene recente al margine nord-orientale del bacino intermontano della piana di colfiorito (umbria-marche). lo scavo attraversa lo spartiacque appenninico a circa 760 m s.l.m. (sella di fonte delle mattinate; fdm) lungo una delle principali vie intermontane di questo settore della catena. studi integrati, lito-pedostratigrafici e archeologici, descrivono una dettagliata storia degli eventi geo-ambientali e dell’occupazione umana di quest’area strategica nel corso dell’ultimo bond cycle dello stadio isotopico 3 (ois3; ca. 38-29 gisp2 ka b.p.). la parte più bassa della sequenza è rappresentata da sedimenti di un sistema fluviale costituito da un canale attivo e un’adiacente piana soggetta alternativamente a episodi di esondazione e di pedogenesi, questi ultimi testimoniati da un profondo paleosuolo (vertisuolo) datato a 31.510±860-30.970±31028.910±390-28.300±790 14c anni b.p. il paleosuolo è sepolto da diversi metri di sedimenti ghiaioso-limosi ascrivibili ad un sistema di conoide alluvionale attivo fra 25.930±325 e 24.150±120 14c anni b.p. il paleosuolo e due sottili livelli limosi alla base delle alluvioni hanno restituito manufatti del paleolitico superiore ed altre tracce archeologiche compatibili con brevi, ma ripetuti episodi di occupazioni umana. i dati cronologici e stratigrafici disponibili indicano infatti che l’area del sito fu frequentata, probabilmente in maniera sistematica, durante tutto il periodo di formazione del paleosuolo fino ai primi episodi di sedimentazione alluvionale che ne hanno determinato il seppellimento. in termini di cronologia radiocarbonio questo periodo copre almeno l’intervallo compreso fra ca. 31 e 26 ka b.p. la fase di pedogenesi a fdm, contemporanea ai primi episodi di frequentazione umana, risulta coeva ad un periodo di clima mite che ha visto in un’ampia area dell’appennino centrale la formazione di un diffuso paleosuolo datato nell’intervallo 33-29 14c ka b.p. e correlato ai primi millenni dell’ultimo ciclo di bond dell’ois3 (greenland interstadial 8-7; ca. 38-34 cal ka b.p. in anni gisp2 icecore). la successiva fase di sedimentazione alluvionale e di contemporaneo abbandono del sito può essere invece correlata all’episodio di estremo raffreddamento dell’heinrich event 3 (ca. 30-29 gisp2 ka b.p.) che chiude il summenzionato ciclo climatico di bond. la coincidenza dell’abbandono di quest’area strategica con l’inizio dell’he3 suggerirebbe che durante l’ois3 le modificazioni geoambientali associate a questi eventi condizionarono pesantemente le strategie dei gruppi paleolitici, probabilmente limitando o modificando la mobilità nelle aree montane più interne dell’appennino centrale. abstract: giaccio b. (et al.), geoenvironmental and human response to the sub-orbital climatic oscillations of the ois3: geoarchaeological evidence from the colfiorito plain (central italy). (it issn 0394-3356, 2004). the colfiorito plain is a plio-quaternary tectono-karstic intermontane basin of the central apennines, located at ~750 m a.s.l. a large excavation was recently made across the fonte delle mattinate (fdm) saddle, an important mountain pass along one of the main natural way of the region connecting the tyrrhenian and adriatic side. combined, litho-pedostatigraphic and archaeological analyses describe a detailed geoenviromental evolution and correlated human occupation history of this strategic area in the course of the last bond cycle of the oxygen isotope stage 3 (ois3; ca. 38-29 gisp2 ka b.p.). the lowest part of the succession is related to a fluvial depositional system, represented by an active channel and an adjacent floodplain which was in turn subjected to overbanking episodes and pedogenetic processes testified by an evolved paleosol (vertisol) dated to 31.510±860-30.970±310-28.910±390-28.300±790 14c yr b.p. the paleosol is buried by a thick sequence of gravely silty sediments ascribable to debris-flow-dominated fan depositional system. radiocarbon dates from the base and top of this unit place the this environmental shift between 25,930±325 b.p. and 24,150±120 b.p. the paleosol and the two silty levels at the base of the alluvial fan sediments yielded early upper palaeolithic artefacts and associated features consistent with brief, but frequent episodes of human occupation. the available stratigraphic and radiocarbon data indeed indicate that human occupation at fdm area was probably systematic, and lasted the whole period of the soil formation up until the first alluvial episodes responsible for its burial. in terms of the radiocarbon chronology, this period spans at least the interval between 31,510±860, age of the oldest anthropogenic charcoals embedded in the paleosol, and 25,930±325, date of the uppermost documented archaeological layer of the sequence. the site being definitively abandoned after this latter date. based on lithostratigraphic data and chronology the fdm paleosol has been correlated with a pedomarker well documented throughout central apennine. furthermore, regional pollen information and tephrochronological data suggest that the formation of both fdm and central apennine paleosol(s) occurred during a mild and wet climatic phase corresponding to the firsts millennial of the last bond cycle of the ois3 (greenland interstadial 8-7; ca. 38-34 gisp ka b.p. the subsequent co-occurrence of geoenvironmental change and human abandonment can be correlated with the heinrich event 3 (he3; ca. 30-29 gisp2 ka b.p.), the last coldest episode of the above mentioned bond cycle. such site evidence for synchronous geoenvironmental and human responses to the he3, suggests that during the ois3 the environmental changes related to the hes had a significant impact on palaeolithic communities, probably limiting or modifying their mobility in the central apennine mountains. parole chiave: stadio isotopico 3, oscillazioni climatiche sub-orbitali, modificazioni ambientali, paleolitico superiore, italia centrale. keywords: oxygen isotope stage 3, sub-orbital climatic oscillations, environmental modifications, upper palaeolithic, central italy . il quaternario italian journal of quaternary sciences 17(2/1), 2004, 231-247 232 b. giaccio et al. 1. introduzione l’identificazione della marcata variabilità climatica dell’ultimo glaciale, ben evidenziata per la prima volta dai record nord atlantici e groenlandesi (es. bond et al., 1992; dansgaard et al. 1993; grootes et al., 1993), ha posto da oltre un decennio al centro degli interessi di un vasto campo delle scienze del quaternario lo studio della variabilità spazio-temporale e dell’impatto geoambientale dei cicli climatici suborbitali noti come cicli di dansgaard/oeshger (d/o) e heinrich events (hes) in tutti gli archivi naturali terrestri (voelker, 2002, per una recente ampia sintesi internazionale). nel panorama delle ricerche in corso in questo ambito sono state evidenziate marcate e rapide variazioni anche nei sistemi vegetali e negli ambienti marini della regione mediterranea (es. watts et al., 1996; allen et al., 1999; chaco et al., 1999; paterne et al., 1999); variazioni che in base a più recenti studi risulterebbero in fase con i cicli climatici sub-orbitali delle alte latitudini (roucoux et al., 2001; moreno et al., 2002; sánchez goñi et al., 2000; 2002). nel loro complesso questi studi indicano l’alternanza di periodi relativamente caldo-umidi e freddo-aridi rispettivamente correlati alle fasi interstadiali e stadiali dei cicli di d/o, con estremi di aridità e raffreddamento durante gli hes. ancora largamente incomplete restano invece le attuali conoscenze circa il significato stratigrafico e gli effetti di questi eventi climatici sull’evoluzione degli ambienti subaerei mediterranei (es. giraudi, 1996; mokhtari fard, 2001; giaccio et al., 2004a). solo recentemente inoltre si sta ponendo l’attenzione su questa eccezionale variabilità climatica come potenziale fattore coinvolto nei processi di modificazione bio-culturale del pleistocene recente europeo (es. giraudi & mussi, 1999; d’errico & sánchez goñi, 2003; fedele et al., 2003; giaccio et al., 2004b). una delle principali cause all’origine di queste significative lacune risiede senza dubbio nei limiti intrinseci degli archivi subaerei (scarsa risoluzione, presenza di ampie e frequenti discontinuità, difficoltà di datazione e correlazione con le curve paleoclimatiche regionali e super-regionali ad alta risoluzione, scarsa rilevanza degli indicatori paleoclimatici, ...), che al momento relegano queste sequenze ad un ruolo marginale negli studi della variabilità climatica ad alta frequenza. è innegabile tuttavia che queste rappresentano comunque le uniche fonti di informazione diretta per ricostruire le modificazioni fisiche degli ambienti subaerei e più in generale le dinamiche interattive del sistema uomo-ambiente. in questa prospettiva è stata investigata una successione del pleistocene superiore al margine nordorientale del bacino intermontano della piana di colfiorito (umbria-marche) in corrispondenza dello fig. 1 veduta panoramica e modello tridimensionale del terreno della piana di colfiorito con ubicazione del sito di fonte delle mattinate (fdm). panoramic view and digital elevation model of the colfiorito plain with location of the fonte delle mattinate (fdm) site. spartiacque appenninico (fig. 1). evidenze lito-pedostratigrafiche descrivono la storia dell’evoluzione ambientale locale nel corso dell’intervallo 32-18 14c ka b.p., rivelando con particolare dettaglio e risoluzione stratigrafica gli episodi degli ultimi nove millenni dello stadio isotopico 3 (ois3), un periodo che ha visto in rapida successione le più marcate oscillazioni interstadiali-stadiali dell’ultimo glaciale. la sequenza indagata ha inoltre restituito importanti tracce di ripetute occupazioni umane ascrivibili alle prime fasi del paleolitico superiore. ciò ha permesso di comparare, indipendentemente da ulteriori ed incerte correlazioni cronologiche, dati archeologici e paleoambientali, e quindi di valutare contestualmente le potenziali interazioni fra i processi climatico-ambientali e la frequentazione umana dell’area. dopo una descrizione generale del contesto stratigrafico e archeologico, viene proposta un’ipotesi di correlazione della successione in esame con altre sequenze continentali appenniniche, nonché un primo tentativo di inquadrare l’evoluzione ambientale nell’ambito più generale della ciclicità climatica dell’ois3. il successivo esame combinato di entrambi i gruppi di dati, geologici e archeologici, suggerirebbe una significativa relazione fra occupazione umana e modificazioni ambientali, a loro volta controllate dalle principali oscillazioni climatiche millenarie dell’ultimo bond cycle dell’ois3 ed in particolare dall’he3. i risultati sono infine discussi sia in termini di implicazioni geoarcheologiche locali, sia nella più ampia prospettiva delle evidenze emerse nell’area mediterranea. 2. il quadro geologico e geomorfologico il bacino di colfiorito è una depressione intermontana di origine tettono-carsica formatasi durante la fase estensionale che ha caratterizzato la catena appenninica nel plio-quaternario (calamita et al., 1998; coltorti et al., 1998; messina et al., 2002). la piana si sviluppa ad una quota media di 750 m s.l.m. ed è bordata da rilievi con cime che si elevano a circa 1000-1300 m s.l.m. (fig. 1). sul suo fianco nord-orientale è presente una faglia normale, con direzione nw-se ed attività quaternaria, che rappresenta l’elemento strutturale principale della depressione. questa faglia mette a contatto i calcari meso-cenozoici della dorsale montuosa con i depositi quaternari della piana, costituiti da limi lacustri a cui si intercalano, in prossimità dei versanti, ghiaie di conoide alluvionale. sui versanti e/o alla loro base sono presenti depositi clastici grossolani variamente cementati. la piana di colfiorito è separata dalla valle del fiume chienti dalla sella di fonte delle mattinate (fdm; ca. 770 m s.l.m), costituita in gran parte da un deposito di frana che impedisce il naturale deflusso delle acque verso i l mare adriatico (galadini et al., 2003). attualmente il deflusso è assicurato da una serie di canali drenanti e da una galleria artificiale del xv secolo. questo sistema drenante è stato recentemente sostituito da una nuova galleria che attraversa la sella di fdm. prima della costruzione di tali opere, le prime risalenti al primo/secondo secolo a.d. (galadini et al., 2003), le acque defluivano in una serie di inghiottitoi di origine carsica tuttora in parte attivi ai bordi del bacino (messina et al., 2002). 233la risposta ambientale ed umana ... 3. stratigrafia e contesto paleoambientale 3.1. caratteri pedo-sedimentari la successione stratigrafica della sella di fdm è stata ricostruita attraverso lo studio di un’ampia sezione messa in luce nel corso dei lavori connessi alla realizzazione della nuova galleria drenante. la trincea attraversa il settore meridionale della sella esponendo i depositi per una profondità massima di circa 15 m e per un’estensione laterale di diverse decine di metri. il substrato della successione in esame è costituito da depositi caotici, affioranti esclusivamente in un settore limitato a nord della trincea, riferibili ad una paleofrana che ha fortemente condizionato l’evoluzione geoambientale locale (galadini et al., 2003) (fig. 2). la discreta estensione dell’affioramento ed un accurato esame lito-pedostratigrafico hanno permesso di distinguere nell’ambito della successione cinque diverse unità (fig. 3). una sintetica descrizione delle principali caratteristiche lito-pedologiche e sedimentologiche delle unità è fornita in figura 3. 3.2. sistema ambientale e sua evoluzione unità a-b l’associazione di litofacies e la geometria interna dell’unità a mostrano tutti i principali elementi caratteristici di un deposito di point-bar, ben individuato soprattutto per la presenza dell’elemento architetturale dominante di tipo lateral accrection (fig. 2) (miall, 1988; 1996). tale struttura sedimentaria è tipica dei sistemi fluviali tipo gravel-bed wandering e/o gravelbed meanderig caratterizzati da un singolo canale principale attivo, presenza di isole e scattered bars e una sinuosità da medio-alta (gravel-bed wandering river) ad alta (gravel-bed meandering river) (miall, 1996). questi sistemi sono compatibili con diverse condizioni di gradiente topografico e con regimi di corrente da torrenziale a sluggish (jackson, 1978). i caratteri di litofacies e pedofacies che contraddistinguono l’unità b suggeriscono invece meccanismi deposizionali legati a fenomeni di esondazione. i rapporti stratigrafici fra le unità a e b suggerirebbero inoltre che entrambe rappresentino gli elementi del medesimo sistema deposizionale fluviale costituito da un canale attivo (unità a) e da un’adiacente floodplain soggetta alternativamente a episodiche fasi di sedimentazione pelitica, in occasione dei fenomeni di esondazione, e a processi subaerei pedogenetici (unità b). tale interpretazione è in accordo con il grado di maturità del paleosuolo che aumenta nella direzione opposta a quella di migrazione del canale (figg. 2 e 3) (bown & kraus, 1987). l’insieme dei caratteri del paleosuolo (fig. 3), ed in particolare la diffusa presenza di slickensides, suggerirebbero che si tratti di un vertisuolo. pur considerando le modeste estensioni dell’affioramento, i caratteri pedo-sedimentari dell’insieme delle unità a-b suggeriscono la presenza di un sistema fluviale del tipo appena descritto attivo in un momento successivo all’evento franoso e sub contemporaneo alla formazione del paleosuolo datato nell’intervallo di circa 32-28 14c ka b.p. (figg. 2 e 3; tab. 1). considerando il contesto topografico è possibile interpretare tale segmento fluviale come elemento di una più ampia rete idrografica drenata da uno o più inghiottitoi carsici presenti nel settore settentrionale del bacino di colfiorito (messina et al., 2002). 234 fi g. 2 s ch em a st ra tig ra fic o e p ar tic ol ar i f ot og ra fic i d el la s uc ce ss io ne d i f on te d el le m at tin at e. s tr at ig ra p hi c sc he m e an d s om e p ho to gr ap hi c d et ai ls o f t he f on te d el le m at tin at e se q ue nc e. b. giaccio et al. 235 fi g. 3 p rin ci p al i c ar at te ri p ed ose d im en ta ri d el la s eq ue nz a d i f on te d el le m at tin at e. m ai n p ed ose d im en ta ry c ha ra ct er s of t he f on te d el le m at tin at e se q ue nc e. la risposta ambientale ed umana ... 236 unità c l’associazione di facies di questa unità è in larga misura indicativa di sedimenti generati da flussi di massa. le forme lenticolari dei singoli corpi ghiaiosi, l’assenza di embriciature, lo scarso grado di stratificazione e gradazione e la presenza di abbondante matrice sono compatibili con meccanismi deposizionali da debris flow. le litofacies più frequenti (gcm) indicano la prevalenza di pseudo-plastic debris flow generati da flussi viscosi o turbolenti a bassa energia e più occasionali clast-rich debris flow e plastic debris flow (gci e gmm) generati a più alta energia (miall, 1996). i rari intervalli di litofacies gt suggeriscono la presenza sporadica di flussi trattivi confinati in piccoli canali effimeri, mentre gli intervalli pelitici sono riconducibili a depositi da esondazione confinati, prevalentemente, nelle depressioni esistenti fra i singoli lobi di ghiaia, generate dalle forme biconvesse dei debris flow. questa associazione è compatibile con un sistema deposizionale di conoide alluvionale, classificabile come debris-flowdominated fan (stanistreet & mccarthy, 1993) o “true” fan (blair & mcpherson, 1994) attivo nell’intervallo 25.930±325-24.150±120 b.p. 14c anni b.p (figg. 2 e 3). unità d-e la natura prevalentemente siltosa dell’unità d suggerisce una sedimentazione in ambiente lacustre-palustre. le geometrie interne e la morfologia esterna delle ghiaie gp, intercalate ai limi, sono invece interpretabili come barre trasversali che indicano l’attivazione episodica di correnti trattive e flussi canalizzati diretti verso la soglia. entrambi questi elementi indicano una fase di innalzamento del livello del lago con la formazione di un emissario in un periodo compreso tra 24.150±120 e 18.480±140 14c anni b.p. (figg. 2 e 3). gli indizi di moderati processi di pedogenesi al top dei livelli dell’unità d indicherebbero un abbassamento del livello lacustre e l’instaurarsi di condizioni di sostanziale stabilità intorno a ca. 18 14c ka b.p. questa fase di relativa stabilità è in seguito interrotta dalla ripresa della sedimentazione di conoide alluvionale dell’unità e (figg. 2 e 3). 4. contesto archeologico 4.1. aspetti archeostratigrafici, tafonomici e processi di formazione del sito nell’ambito della successione sono stati riconosciuti tre livelli contenenti chiare tracce di frequentazione umana del paleolitico superiore. questi corrispondono alla parte alta del paleosuolo (unità b) e ai due orizzonti pelitici alla base dell’unità c (figg. 2 e 3). i tre livelli hanno un’età compresa tra 31.510±860, la più antica fra le misure 14c dei carboni antropogenici contenuti nel paleosuolo (tab. 1; fig. 3), e 25.930±325 14c anni b.p., data del più alto livello archeologico accertato della serie. le testimonianze archeologiche insistono lungo buona parte delle pareti della trincea dove si osservano aree ad elevata densità di vestigia (concentrazioni di manufatti, lenti carboniose, resti di fauna e frammenti di ocra) alternate ad altre quasi del tutto prive di testimonianze. i resti presentano la massima concentrazione all’interno del paleosuolo, con un progressivo diradamento nei due livelli dell’unità c. in particolare, a circa dieci centimetri di profondità dal top del paleosuolo il materiale archeologico si presenta concentrato e ben organizzato in un singolo livello centimetrico, all’interno del quale i reperti giacciono con gli assi maggiori paralleli alle superfici di strato. una simile distribuzione dei resti caratterizza anche i due livelli archeologici dell’unità c dove si osservano distinti e sottili orizzonti ricchi di materiale separati da livelli limosi completamente sterili (particolare in fig. 2). tab. 1 misure 14c ed età calibrate dei campioni prelevati lungo la sequenza di fonte delle mattinate (nell’ultima colonna a destra sono riportati gli episodi climatici groenlandesi secondo la cronologia della carota gisp2 [meese et al., 1997]). le misure sono state effettuate su diversi tipi di materiali: carboni antropogenici (b3-27, c3-27 e fdm1); limi associati a carboni antropogenici (fdm3); paleosuolo (orizzonte a, fdm2); livelli limosi (col1 e fdm4); sedimenti colluviali (fdm5). i campioni sono stati analizzati dal scottish universities research and reactor centre (uk) (fdm2, 3, 4 e 5), beta analitic inc. (usa) (fdm1 e col1) e dal laboratorio di datazioni del dipartimento di fisica dell'università di roma “la sapienza” (b3-27 e c3-27). le datazioni più recenti di ca. 20 14c ka b.p. sono state calibrate con il programma calib rev4.4 (database intacal98 [stuiver et al. 1998]). per le misure maggiori di 20 ka è stata invece ottenuta una stima di calibrazione utilizzando i dati riportati in hughen et al (2004) e beck et al. (2002). 14c and calibrated ages of the samples collected at the fonte delle mattinate sequence (the right column reports the greenland climatic events according to the gisp2 time-scale [meese et al., 1997]). the measurements are related to different materials: anthropogenic charcoal (b3-27, c3-27 e fdm1); silt with anthropogenic charcoal (fdm3); paleosol (horizon a, fdm2); silty layers (col1 and fdm4); colluvial deposits (fdm5). the samples were analysed by scottish universities research and reactor centre (uk) (fdm2, 3, 4 e 5), beta analitic inc. (usa) (fdm1 e col1) and by dating laboratory of the dipartimento di fisica dell'università di roma “la sapienza” (italy) (b3-27 e c3-27). the dates younger than ca. 20 14c ka b.p. were calibrate by using the software calib rev4.4 (intacal98 database [stuiver et al. 1998]). the dates older than 20 ka have been calibrated by using the data reported in hughen et al (2004) e beck et al. (2002). camp. unità materiale cod. lab. tecnica età 14c 2σσ età cal (ka bp) greenland fdm5 f colluvio gu-9428 rad. 4970b 70 5773-5594 / 5891-5782+ fdm4 top d silt organico gu-9427 rad. 18.840b 140 23,161-21,611+ g12 col1 top c silt organico rad. 24.150b 120 ~29-27,5*; 29,5-28,5# he3-g14 fdm3 base c silt con carboni gu-9426 rad. 25.930b 330 ~30,5-29*; 31-30# he3 c3-27 top b carbone rad. 28.300a 790 ~34-30,5*; 35,5-32# g17-g15a fdm2 top b paleosuolo gu-9425 rad. 28.910b 390 ~34,5-32*; 35,5-32,5# g17-g15 fdm1 top b carbone beta-185354 ams 30.940b 310 ~36-34,5*; 38-37# g18-g17 b3-27 top b carbone rad. 31.510a 860 ~37-35*; 39,5-38# he4-g17 b. giaccio et al. 237 fig. 4 vista generale e alcuni particolari di una delle aree ad elevata concentrazione di resti culturali al top del paleosuolo (unità b) esplorata nel corso di uno scavo di emergenza. general view and details of one of the areas with high density remains at top of the paleosol (unit b) explored in during an emergence excavation. la risposta ambientale ed umana ... i dati emersi nel corso di un scavo di emergenza, che ha interessato una limitata porzione della superficie del sito, hanno inoltre evidenziato che il livello al top del paleosuolo costituisce un livello di occupazione umana con abbondanti manufatti litici, rari reperti faunistici, frammenti di ocra, carboni ed alcuni massi calcarei decimetrici del tutto isolati nel deposito limoso (fig. 4). indizi forniti sia dalle caratteristiche morfometriche di questi ultimi sia dal contesto sedimentologico del deposito, suggerirebbero che tali elementi siano di apporto antropico. in particolare, il refitting di un nucleo indica che la superficie indagata rappresenta un’area di lavorazione relativa ad un ben distinto episodio di frequentazione umana in condizioni di giacitura primaria pressoché indisturbate (fig. 5). nel loro complesso, questi elementi indicherebbero la probabile presenza di strutture e una certa organizzazione spaziale nell’uso dell’area di fdm (cfr. silvestrini et al., in stampa). sensibilmente diversa è la giacitura dei reperti negli orizzonti più profondi del paleosuolo dove il materiale appare privo di una precisa organizzazione stratigrafica e decisamente disperso fino alla profondità di oltre un metro. sul piano tafonomico, questa marcata differenza può essere verosimilmente addebitata ad un disturbo post-deposizionale legato ai particolari processi pedogenetici propri dei vertisuoli (contrazioni e dilatazioni della componente argillosa con continua dislocazione dei materiali). in termini di processi di formazione del sito, la coesistenza dei resti archeologici indisturbati con quelli coinvolti nei processi vertici implicherebbe che la frequentazione umana sia iniziata nelle fasi di piena attività della pedogenesi e sia perdurata fino al seppellimento del suolo. più precisamente, a partire dai primi momenti di occupazione umana, databili ad almeno 31.510±860 14c anni b.p. (tab. 1), il successivo alternarsi di episodi di frequentazione e di aggradazione dell’unità b, nonché la continuità dei processi pedogenetici in atto, ha determinato la formazione dell’orizzonte archeologico caratterizzato da drastici disturbi postdeposizionali. nel periodo compreso fra 28.910±390/28.300±790 e 25.930±325 14c anni b.p., che ha visto i primi impulsi della sedimentazione alluvionale dell’unità c e gli ultimi episodi di frequentazione umana, si determina invece il seppellimento del suolo con il conseguente arresto dei movimenti vertici e preservazione dei resti archeologici in livelli di occupazione ben distinti e separati da sedimenti sterili. considerando un simile quadro dei processi di formazione del sito, le datazioni delle lenti carboniose al top del paleosuolo (tab. 1) indicherebbero solo l’età minima dell’inizio della frequentazione umana a fdm, che quindi è verosimilmente più antica di 31.510±860 14c anni b.p. 4.2. osservazioni sui manufatti litici e la fauna in generale i manufatti litici mostrano un discreto stato di conservazione. le superfici si presentano infatti prive di abrasioni e corrosione, quasi del tutto assenti sono pure le sbrecciature postdeposizionali, anche su reperti laminari con margini taglienti estremamente sottili e fragili. molto frequenti sono invece le frammentazioni dei prodotti della scheggiatura, siano esse intenzionali o di origine postdeposizionale. sebbene l’esiguità del numero dei pezzi integri non permetta soddisfacenti analisi tipometriche, e quindi precise caratterizzazioni dei tre livelli antropici, alcune differenze negli indici d’allungamento si possono tuttavia notare. il materiale al top del paleosuolo (unità b) si distingue infatti per prodotti tendenzialmente meno laminari rispetto a quelli presenti alla base dell’unità c, mentre l’indice di carenaggio risulta concorde nei tre livelli. sotto il profilo tecnologico-tipologico i reperti si caratterizzano per l’abbondanza di prodotti di scheggiatura grezzi (con margini non modificati debitage) fortemente laminari, associati a schegge spesse ampiamente ricoperte da cortice. molto rari i reperti diagnostici (fig. 6) tra i quali si segnalano: una piccola lama denticolata (d1, secondo la nomenclatura di laplace, 1964), un doppio incavo (d1), un raschiatoio denticolato (d2), una punta denticolata (d3), un raschiatoio denticolato carenoide (d6), un grattatoio (g1), un grattatoio con incavo (g2), un raschiatoio marginale (r1), un raschiatoio su lama (r2), un bulino (b1), due microlamelle a dorso (ld1) inquadrabili nella variante lamella dufour, due lame a dorso (ld1 ld2), una punta a dorso (pd4) inquadrabile nel sottotipo microgravette, una troncatura marginale (t1), una troncatura semplice (t1), una troncatura obliqua (t3), un becco (bc2), una lama a ritocco 238 fig. 5 particolare della paleosuperficie illustrata in figura 4. le frecce indicano i prodotti di scheggiatura rimontati nel nucleo raffigurato in basso. details of the paleosurface of figure 4. the arrows indicate the flakes refitted in the core of the lower panel. b. giaccio et al. denticolato (l2). nel complesso tale associazione suggerisce, in accordo con i dati cronometrici (tab. 1), un ambito culturale del paleolitico superiore antico (early upper palaeolithic come definito da gamble, 1999), ascrivibile, secondo silvestrini et al. (in stampa), all’aurignaziano. i resti di fauna sono decisamente scarsi, molto frammentari e generalmente in cattive condizioni di conservazione. lo stato di alterazione è particolarmente avanzato sui reperti rinvenuti nel paleosuolo, dove le ossa si presentano con superfici corrose, struttura disaggregata e in alcuni casi quasi completamente dissolte dai processi pedochimici. fra i rari reperti determinabili, tutti rinvenuti nel paleosuolo, si segnalano: un frammento di ramo orizzontale di mandibola dx con molari di bos primigenius (aurochs); un molare (3 super. dx) di equus ferus cf germanicus (cavallo selvatico) (f. fedele, com. pers.) e alcuni denti di cervidae. 5. correlazione con alcuni record paleoambientali regionali e super-regionali le successioni tardopleistoceniche di ambiente alluvionale e di versante dell’appennino centrale sono caratterizzate da alternanze di depositi ghiaioso-sabbiosi e di livelli pedogenizzati (es. frezzotti & giraudi, 1992; giraudi & frezzotti; 1997; miccadei et al., 1998). fra questi ultimi si distingue un caratteristico paleosuolo sviluppato su ceneri vulcaniche correlate all’ignimbrite campana che costituisce un importante marker stratigrafico di un’ampia area dell’appennino centrale (frezzotti & narcisi, 1996; giraudi & frezzotti, 1997). le numerose datazioni radiocarbonio disponibili per questo pedomarker (fig. 7) definiscono un picco di massima frequenza compreso tra 32.000 e 30.000 14c anni b.p. (frezzotti & narcisi, 1996, cum biblio; giraudi 239 fig. 6 alcuni reperti selezionati dal sito di fonte delle mattinate: 1-2 punta e lamella (dufour) a dorso marginale; 3 punta a dorso (microgravette); 4-5 bulini; 6 bulino/grattatoio; 7 grattatoio carenato; 8-9 troncature; 10-11 coltelli a dorso; 12-19 lame e lamelle grezze. some selected lithics from fonte delle mattinate site: 1-2 point bladelet (dufour) and bladelet (dufour) point with marginally backed; 3 backed point (microgravette); 4-5 burins; 6 burin/endscraper; 7 carinate endscraper ; 10-11 back-knife; 12-19 unretouched blades and bladelets. la risposta ambientale ed umana ... & mussi 1999, cum biblio; moro et al., 2002, cum biblio) perfettamente compatibile con l’età del paleosuolo di fdm (tab. 1). la correlazione tra il pedomarker e il paleosuolo di fdm è ulteriormente corroborata da forti analogie stratigrafiche che legano la successione di fdm a quelle appenniniche contenenti il pedomarker. molte fra queste successioni mostrano infatti la stessa sequenza di fdm costituita dal pedomarker sepolto da sedimenti ghiaiosi la cui associazione di facies è compatibile con conoidi alluvionali (giraudi & frezzotti, 1997; giaccio et al. 2004b). lo sviluppo di un sistema deposizionale di conoide alluvionale (unità c) a fdm corrisponde dunque ad un fenomeno che ha interessato ampi settori dell’appennino centrale. i prodotti dell’eruzione dell’ignimbrite campana (ic), costituenti il parent material del pedomarker appenninico, sono stati identificati nella sequenza pollinica del lago grande di monticchio (narcisi, 1996), nella carota tirrenica ket 8003 (ton-that et al., 2001) e, come segnale vulcanogenico, nella stratigrafia isotopica groenlandese (fedele et al., 2003) esattamente in corrispondenza dell’inizio dell’heinrich event 4 (he4). i dati radiocarbonio disponibili e la peculiare posizione paleoclimatica dell’ic permettono di identificare, nell’ambito di questi importanti record, la fase climatica in cui si instaurarono le condizioni ottimali per lo sviluppo del pedomarker appenninico e quindi del coevo paleosuolo di fdm. questa corrisponde alla zona pollinica 5b della sequenza di monticchio (es. allen et al., 1999) e alle prime fasi del ciclo di bond (bond et al., 1993; bond & lotti, 1995) che segue con il brusco riscaldamento del greenland interstadial 8 (gi8, sensu walker et al., 1999) la fine dell’he4 (fig. 7). questa correlazione è supportata dalle seguenti osservazioni stratigrafiche e cronometriche: i) il gi8 e la zona pollinica di monticchio 5b (mpz5b) coincidono con il primo sensibile aumento della temperatura ed umidità dopo la deposizione del parent material del pedomarker (ic) e quindi la prima fase favorevole alla pedogenesi; ii) il gi8 e la mpz5b rappresentano rispettivamente l’ultimo ben marcato e prolungato interstadiale e l’ultimo episodio di notevole abbondanza di taxa arborei dell’ultimo glaciale, ovvero l’ultima fase climatica dell’ultimo glaciale compatibile con lo sviluppo di un diffuso e profondo suolo; iii) secondo allen & huntley (2000) e dasgaard et al. (1993) la mpz5b e il gi8 sono correlati all’interstadio di denekamp che nell’europa temperata è rappresentato da un diffuso paleosuolo sviluppatosi nell’intervallo 32.000-28.000 14c anni b.p. (bhere, 1989) coevo quindi al pedomarker e al paleosuolo di fdm; iv) la calibrazione stimata delle misure 14c (beck et al., 2001; hughen et al., 2004) disponibili per il pedomarker definisce un intervallo di massima frequenza di ca. 38-35 cal ka b.p., un periodo che comprende il gi8 e 7 (fig. 7). avvalendosi di tale correlazione e considerando le datazioni radiocarbonio disponibili (tab. 1), è possibile avanzare alcune ipotesi sul significato paleoambientale di altre unità stratigrafiche di fdm, alla luce del dettagliato quadro paleoclimatico e cronologico fornito dal record groenlandese e di monticchio. l’unità alluvionale c, che determina il seppellimento del paleosuolo al tetto dell’unità b, rappresenta la risposta morfologico-sedimentaria di una fase resistatica che segue le precedenti condizioni biostatiche di cui il paleosuolo è chiara espressione. i dati radiocarbonici di fdm indicherebbero che questa modificazione geoambientale, corrispondente alla più importante fase di sviluppo della conoide alluvionale (unità c, figg. 2 e 3), si verificò tra 26 e 24 14c ka b.p. (tab. 1, figg. 2 e 3), un intervallo che secondo numerosi record marini coinciderebbe con l’he3 di (bond et al., 1993; bond & lotti, 1995; cortijo et al., 1997; cacho et al., 1999; thouveny et al., 2000). pur considerando le incertezze cronologiche relative alla differenza tra età radiocarbonio marina e atmosferica, questa fase di peggioramento climatico può essere verosimilmente correlata all’he3. i dati attualmente disponibili sulle fluttuazioni del 14c atmosferico (beck et al., 2001; hughen et al., 2004) permettono infatti di ottenere una stima di calibrazione delle misure radiocarbonio della base e del tetto dell’unità c congruenti con l’età di questo evento (tab. 1; fig. 7). in termini stratigrafici, l’he3 rappresenta inoltre la fase stadiale più acuta dopo la formazione del paleosuolo correlato al gi8-6 (fig. 7) e quindi, anche sul piano paleoclimatico, un episodio perfettamente compatibile con le modificazioni ambientali documentate a fdm da un’importante fase alluvionale. in sintesi, i dati stratigrafici e cronologici di fdm indicherebbero che la successione comprendente le unità a-b-c sia ascrivibile all’intero ciclo di raffreddamento millenario (bond cycle) verificatosi tra il gi8 e l’he3 (ca. 38-29 gisp2 ka b.p.; fig. 7). la fase di impostazione del lago di colfiorito, o di innalzamento del suo l ivello, che segue l’he3 (<24.150±120 e >18.480±140 14c anni b.p.) è correlabile all’alto stazionamento lacustre dell’ultimo massimo glaciale, ben documentato nell’appennino abruzzese (es. giraudi & frezzotti, 1997) e in altre regioni del mediterraneo (prentice et al., 1992). in particolare, nel caso del bacino di colfiorito, l’espansione dello specchio lacustre può essere stata favorita sia dalle generali condizioni idrologiche dell’ultimo massimo glaciale caratterizzate da un bassissimo tasso di evapotraspirazione tale da compensare le scarse precipitazioni di questo periodo (prentice et al., 1992) sia da una probabile ostruzione degli inghiottitoi carsici favorita all’aumento degli apporti detritici grossolani. anche in questa fase di massimo livello lacustre, l’area del sito di fdm conobbe tuttavia solo periodici episodi di completa sommersione alternati a momenti di emersione caratterizzati dalla formazione di un emissario. il successivo periodo che vede il ristabilirsi di condizioni di stabilità, favorevoli allo sviluppo di un suolo intorno ai 18 14c ka b.p., potrebbe invece correlarsi al fornaca interstade: una fase climatica mite che ha interessato l’appennino centrale dopo la massima avanzata dei ghiacciai abruzzesi (giraudi & frezzotti, 1997). questa fase potrebbe corrispondere al gi2 nonché a uno dei picchi di maggiore abbondanza di arboree della zona pollinica 4 di monticchio (fig. 7). l’ultimo episodio di sedimentazione alluvionale (unità d) è difficilmente ascrivibile ad una fase climatica ben definita per l’ampia forchetta cronologica che lo delimita (<18.480±140 e >4970±70 14c anni b.p.). esso tuttavia potrebbe corrispondere alla fase di sedimentazione detritica documentata in italia centrale durante he1 (giraudi, 1996) 240 b. giaccio et al. 241 fi g. 7 c or re la zi on e d el la s eq ue nz a d i f on te d el le m at tin at e (f d m ) c on a ltr e su cc es si on i s ub ae re e (p ed om ar ke r) e la cu st ri (m on tic ch io ; a ll e n et a l., 1 99 9; 2 00 0) d el l’a p p en ni no c en tr om er id io na le e c on u n re co rd p al eo at m os fe ric o gr oe nl an d es e (g is p 2; m a y e w s k i et a l., 1 99 7) . p os iz io ne d eg li h ei nr ic h e ve nt s (h s) n el la s eq ue nz a d i m on tic ch io e d el l’i gn im b rit e c am p an a (ic ) n el la ca ro ta g is p 2 ris p et tiv am en te s ec on d o w a tt s et a l. (1 99 6) e f e d e le et a l. (2 00 3) . c al ib ra zi on e st im at a d el le e tà > 20 .0 00 14 c a nn i b .p . 14 c d i f d m (t ab . 1 ) e d el p al eo su ol o sv ilu p p at o su c en er i d el l’i c (p ed om ar ke r: 2 9. 09 0± 35 0; 2 9. 69 0± 11 10 ; 3 0. 11 0± 31 0; 3 1. 22 0± 14 00 ; 3 1. 50 0± 50 0; 3 2. 51 0± 16 00 ; 3 3. 14 0± 14 00 ; 3 8. 77 0± 21 70 ) s ec on d o h u g h e n et a l. (2 00 4) o , s e < 20 .0 00 14 c a nn i b .p ., s tu iv e r et a l. (1 99 8) . s i n ot i c he le s tim e d i c al ib ra zi on e se co nd o b e c k et a l. (2 00 1) q ui n on r ip or ta te p er u na m ag gi or e ch ia re zz a gr af ic a d ef in is co no u n q ua d ro c ro no lo gi co d i u no o d ue m ill en ni p iù a nt ic o (t ab . 1 ), m a an co ra c om p at ib ile , s e no n ad d iri tt ur a p iù c on gr ue nt e, c on la c or re la zi on e p ro p os ta . c or re la tio n of t he f on te d el le m at tin at e se q ue nc e w ith o th er s ub ae ria l ( p ed om ar ke r) a nd la ke (m on tic ch io ; a ll e n et a l., 1 99 9; 2 00 0) s uc ce ss io ns o f th e ce nt ra lso ut he rn a p en ni ne s an d w ith a g re en la nd p al ae oa tm os p he ric r ec or d ( g is p 2; m a y e w s k i et a l., 1 99 7) . p os iti on o f th e h ei nr ic h ev en ts ( h s) i n th e m on tic ch io s eq ue nc e an d o f th e c am p an ia n ig ni m b rit e in t he g is p 2 co re ac co rd in g to w a tt s et a l. (1 99 6) a nd fe d e le et a l. (2 00 3) , r es p ec tiv el y. e st im at e c c al ib ra tio n of t he 14 c a ge s of f d m > 20 ,0 00 14 c y ea rs b .p . o f f d m (t ab . 1 ) a nd o f t he p al eo so l(s ) d ev el op ed o n c i a sh (p ed om ar ke r: 2 9, 09 0± 35 0; 2 9, 69 0± 11 10 ; 3 0, 11 0± 31 0; 3 1, 22 0± 14 00 ; 3 1, 50 0± 50 0; 3 2, 51 0± 16 00 ; 3 3, 14 0± 14 00 ; 3 8, 77 0± 21 70 ) a cc or d in g to h u g h e n et a l. (2 00 4) o r s tu iv e r et a l. (1 99 8) . n ot e th at a cc or d in g to t he b e c k et a l. (2 00 1) d at ac al ib ra tio ns , w hi ch a re n ot r ep or te d h er e, t he c hr on ol og ic al fr am ew or k sh ou ld b e on e or t w o m ill en ni al o ld er , b ut s til l c on si st en t, o r ev en m or e su ita b le , w ith t he p ro p os ed c or re la tio n. la risposta ambientale ed umana ... 6. ciclicità climatica dell’ois3, modificazioni ambientali e discontinuità archeologiche: alcune considerazioni preliminari sul sito di fdm e sul contesto mediterraneo le tracce materiali ed il contesto tafonomico-stratigrafico della successione indagata indicano che il giacimento di fonte delle mattinate rappresenti un sito primario coincidente con un’area di frequentazione umana ai margini di un canale fluviale, soggetta a pedogenesi e a periodici episodi di inondazione. le caratteristiche e la configurazione spaziale dei resti culturali, con aree ad elevata densità di vestigia dislocate in diversi punti di un’ampia superficie, sono compatibili con brevi ma ripetute e non occasionali occupazioni umane. i dati cronologici e stratigrafici disponibili indicano infatti che l’area del sito fu periodicamente frequentata, probabilmente in maniera sistematica, per almeno sei millenni (ca. 32-26 14c ka b.p.), con i primi episodi di occupazione anteriori a 31.510±860 14c anni b.p. in termini paleoambientali, i dati lito-pedostratigrafici indicherebbero condizioni di marcata stabilità favorevoli allo sviluppo di un suolo profondo durante i primi 4-5 millenni della frequentazione. i successivi millenni di frequentazione vedono l’inizio di una certa instabilità ambientale testimoniata dai primi impulsi di sedimentazione alluvionale dell’unità c (fig. 8). sulla base della correlazione proposta (fig. 7), la fase di frequentazione corrisponderebbe all’intervallo compreso tra il gi8 e l’inizio dell’he3 (almeno 37-30 gisp2 ka b.p.); un periodo caratterizzato dalla rapida successione di quattro marcate oscillazioni di d/o (fig. 7). ciò implicherebbe che le quattro fasi stadiali occorse nel periodo che precede all’he3 non abbiano avuto significativi effetti né sull’ambiente, la cui stabilità è interrotta solo da alcuni sporadici episodi alluvionali, né sui gruppi umani che non sembrano interrompere la frequentazione a fdm (fig. 7). queste evidenze sono in accordo con recenti studi di sequenze mediterranee che indicano moderate variazioni climatico-ambientali associate alle fasi stadiali dei cicli di d/o non connessi agli hes (es. cacho et al., 1999; sánchez goñi et al., 2000). questo lungo periodo di periodiche occupazioni umane testimonia una notevole importanza dell’area di fdm per i gruppi umani paleolitici. ciò può essere addebitato a diversi fattori geografici ed ecologici. una prima osservazione può essere avanzata nei riguardi del potenziale carattere strategico dell’area che cade sullo spartiacque appenninico, lungo una delle principali vie che in questo settore della catena consentono un’agevole comunicazione fra versante adriatico e tirrenico. è verosimile che questo corridoio naturale rappresentò una via preferenziale sia per le reti di comunicazione umana che per i movimenti migratori stagionali dei grandi erbivori. altri elementi che probabilmente hanno influenzato la frequentazione paleolitica, sono rappresentati dalla presenza di un corso d’acqua e di un probabile specchio lacustre. entrambi hanno costituito infatti aree preferenziali per gli insediamenti e le frequentazioni di gruppi umani del paleolitico superiore in diversi contesti geografici dell’europa continentale (gribchenko & kurenkova, 1997; bocquet-appel & demars, 2000; chlachula, 2001). questo millenario interesse dei cacciatori raccoglitori sembra interrompersi in coincidenza con un significativo mutamento ambientale connesso all’episodio di marcato raffreddamento dell’he3. le evidenze stratigrafiche di fdm indicano infatti un radicale cambiamento sia del contesto archeologico (totale scomparsa di qualsiasi traccia di presenza umana) sia del quadro ambientale che registra la più significativa fase di sedimentazione alluvionale (fig. 8). in effetti, la sterilità archeologica dei livelli siltosi, presenti nell’unità c e nelle altre unità che seguono verso l’alto, può essere spiegata sia come evidenza di un’effettiva interruzione della frequentazione umana sia come semplice dislocazione della località di stazionamento. entrambi gli scenari, sia pure con gradi e significati molto diversi tra loro, indicano comunque una certa discontinuità coincidente con l’he3 compatibile sia con un totale abbandono dell’area, sia con cambiamenti meno drastici che potrebbero aver coinvolto aspetti inerenti la frequenza, la durata e la localizzazione delle occupazioni, nonché l’entità numerica dei gruppi paleolitici e il tipo di attività svolta a fdm. i dati paleoambientali di monticchio (es. watts et al., 2000) indicano che in appennino meridionale l’he3 coincise con una brusca contrazione delle foreste che lasciarono il posto ad ampi spazi aperti di steppa arida e fredda dominate da artemisia e chenopodiaceae (allen et al., 2000; fig. 7). in termini paleoecologici umani, le basse temperature e l’estrema aridità associate all’he3 non costituiscono per sé stesse significativi fattori limitanti (cfr. vrba et al., 1995). ciò che invece può rivestire un certo significato è l’eccezionale rapidità con la quale si instaurarono tali condizioni ambientali. nel breve periodo di poche generazioni, forse anche una o due secondo i tempi del cambiamento climatico indicati dal record paleoatmosferico groenlandese (es. mayewski et al., 1997; fig. 7), i gruppi umani si trovarono infatti a fronteggiare un ecosistema radicalmente mutato, sia nella distribuzione dei biomi vegetali ed animali che nel pattern della rete idrica. un simile rapido cambiamento probabilmente si inserì nelle dinamiche dei processi interattivi uomo-ambiente come un poderoso agente, in grado di innescare profondi cambiamenti nei comportamenti e nelle strategie di sussistenza. verosimilmente questi processi agirono in modo particolarmente efficace proprio nelle aree simili a quella di fdm, più interne ed elevate dell’appennino centrale e quindi più sensibili e reattive alle modificazioni climatiche. il risultati emersi dai dati di fdm trovano nell’attuale panorama delle ricerche nazionali e internazionali poche altre evidenze di significative discontinuità archeologiche chiaramente connesse alla ciclicità climatica ad alta frequenza dell’ois3, e più in particolare rispetto ai drastici episodi di raffreddamento e inaridimento degli hes. ad esempio, fedele et al. (2003) hanno recentemente evidenziato una netta discontinuità nel record archeologico dell’italia meridionale e di altre regioni dell’europa sudorientale coincidente con l’he4. in quest’ampia area, l’he4 marca infatti un diffuso abbandono di siti, con una probabile importante dislocazione territoriale dei gruppi umani, nonché segna una netta cesura fra i tecnocomplessi dell’earliest upper palaeolithic e i successivi gruppi di industrie dell’early upper palaeolithic (entrambi i termini sensu 242 b. giaccio et al. 243 fig. 8 ricostruzione delle principali tappe dell'evoluzione ambientale e dell'occupazione umana al sito di fonte delle mattinate nel corso dell'intervallo di 32-18 14c ka b.p. o 38-23 cal ka b.p. reconstruction of the main phases of both environmental evolution and human occupation at fonte delle mattinate site during the 3218 14c or 38-23 cal ka b.p. interval. la risposta ambientale ed umana ... gamble, 1999). alcuni autori (es. kozlowski, 1990; gamble, 1999) vedono in questo passaggio un’importante rottura del record archeologico europeo, caratterizzata dalla definitiva scomparsa di una serie di comportamenti radicati nei millenni e la comparsa di nuovi tratti culturali. secondo fedele et al. (2003), queste importanti discontinuità non sono tuttavia connesse esclusivamente ad un possibile impatto dell’he4, quanto piuttosto ad una profonda e vasta crisi ecologica generata dalla sovrapposizione e muta amplificazione degli effetti della catastrofica eruzione dell’ignimbrite campana e dell’he4 (cfr. sinitsyn, 2003). su una base dati e con un approccio completamente diversi, d’errico & sánchez goñi (2003) hanno analogamente riconosciuto nella penisola iberica una significativa discontinuità coincidente con l’he4, che, secondo gli autori, coinvolse sia la sfera culturale (passaggio paleolitico medio/superiore) quanto quella biologica (scomparsa dei neandertal e arrivo dei gruppi umani di anatomia moderna). in questo caso, tuttavia, il quadro proposto appare molto fragile e decisamente discutibile (cfr. finlayson et al., 2004, per una critica su altri aspetti). d’errico & sánchez goñi (2003) tracciano infatti le loro conclusioni comparando per semplice via cronometrica trascurando cioè ogni evidenza stratigrafica dei singoli contesti archeologici il quadro culturale con un record pollinico del mare di alboran; il primo basato su datazioni 14c mentre il secondo su un modello cronologico completamente diverso. al fine di comparare i due gruppi di dati gli autori convertono la scala temporale del record pollinico in anni 14c assumendo che l’età atmosferica dell’inizio dell’he4 sia di 35.000 anni radiocarbonio, cioè la stessa di quella oceanica delle alte latitudini. è noto tuttavia che le differenze fra età marina e atmosferica dell’he4, il così detto marine reservoir age effect, sia tutt’altro che trascurabile, ed è molto probabile che questo raggiunse alle alte latitudini valori superiori a 2000 anni (es. voelker et al., 1998; 2000, cum biblio). recenti studi hanno inoltre evidenziato che in stretta coincidenza temporale con l’he4 si verificò un marcato aumento del flusso di elementi cosmogenici come 10be, 36cl e 14c (es. voelker et al., 2000; wagner et al., 2000; beer et al., 2002). in termini cronometrici, l’elevato flusso di 14c si traduce in marcate distorsioni della scala del radiocarbonio (forti ringiovanimenti, inversioni, dilatazioni e compressioni temporali) con inevitabili ripercussioni sull’interpretazione cronologica delle serie abbraccianti l’he4. ad esempio, voelker et al. (2000) hanno dimostrato che nel mare del nord, sebbene l’he4 sia effettivamente datato a ca. 35 14c ka b.p., i sedimenti di 1000-2000 anni più antichi dell’he4 hanno restituito età radiocarbonio di ca. 32 ka. in ambiente continentale, è stato inoltre constatato (fedele et al., 2003) che in tutte le sequenze archeologiche contenenti l’ignimbrite campana, dall’italia meridionale all’ucraina, l’età media dei livelli immediatamente ricoperti dal tefra, e quindi più antichi dell’he4 (fig. 7), è di soli 33.000-31.000 anni 14c b.p. queste concrete evidenze stratigrafiche rendono poco appropriata la semplice comparazione cronometrica di dati culturali e paleoambientali adottata da d’errico & sánchez goñi (2003), e dunque minano alla base le ipotesi e le conclusioni proposte dagli autori. altrettanto semplicistica appare l’asserita correlazione tra industrie del paleolitico medio e neandertal, da un lato, e tra complessi del paleolitico superiore e uomini di anatomia moderna, dall’altro. al momento infatti, per le fasi più antiche del paleolitico superiore precedenti a ca. 33-32 14c ka b.p. (earliest upper palaeolithic di gamble [1999] o initial upper palaeolithic di bar-yosef & pilbeam [2000]) i resti fossili umani sono rarissimi, frammentari e di dubbia classificazione (cfr. churchill & smith, 2000; trinkaus et al., 2003). non mancano inoltre casi di probabili associazioni tra resti di neandertal e industrie del paleolitico superiore antico (es. ahern et al., 2004). il quadro delle conoscenze in questo ambito appare dunque ancora largamente frammentario e in parte pesantemente condizionato dai limiti e da un uso disinvolto della scala del radiocarbonio. è più che ovvio inoltre che i fattori climatico-ambientali costituiscono solo una parte degli attori in gioco nei processi di cambiamento dei sistemi culturali paleolitici. ogni generalizzazione sul problema delle discontinuità archeologiche formulata alla luce dei soli eventi climatico-ambientali, sia pure in relazione alle estreme condizioni associate agli hes, risulterebbe quindi prematura e inevitabilmente semplicistica. è tutt’altro che improbabile tuttavia, come le evidenze di fdm sembrerebbero suggerire, che i rapidi e drastici cambiamenti associati agli hes abbiano in qualche modo alterato gli equilibri del rapporto uomoambiente, destabilizzando adattamenti e strategie consolidate in secoli o millenni di conoscenza e prevedibilità dei sistemi ambientali. conclusioni lo studio combinato stratigrafico e archeologico della sequenza di fonte delle mattinate (fdm) ha mostrato una chiara relazione tra processi geo-ambientali e occupazione umana entrambi condizionati dalle principali fasi interstadiali e stadiali dell’ultimo ciclo di bond dell’ois3 (ca. 38-29 gisp2 ka b.p.). il record geologico indica condizioni di notevole stabilità ambientale nella fase iniziale del ciclo bond (gi8-6; ca. 38-33 gisp2 ka b.p.) durante la quale a fdm e in un ampio settore dell’appennino centrale si sviluppa un profondo suolo. tra il gi6 e il gi5, il record di fdm registra invece alcuni eventi alluvionali e l’arresto della pedogenesi; primi sporadici impulsi di una sedimentazione alluvionale che ha la sua più importante fase di sviluppo nel corso dell’heinrich event 3 (he3), l’episodio conclusivo di estremo raffreddamento che chiude l’ultimo ciclo di bond dell’ois3. contrariamente al record isotopico groenlandese, ma in accordo con altri indicatori climatici di questa regione e dell’area mediterranea, queste evidenze indicherebbero che gli hes in italia centrale furono caratterizzati da condizioni climatiche freddo-aride e modificazioni ambientali molto più marcate di quelle associate alle altre fasi stadiali dei cicli di d/o. le tracce culturali di fdm indicano che durante tutto il periodo precedente all’he3 (ca. 38-30 gisp2 ka b.p.) il settore nord-orientale della piana di colfiorito fu sede di brevi soste di gruppi umani fasi del paleolitico superiore antico (aurignaziano), probabilmente nell’ambito di spostamenti stagionali lungo una delle principali 244 b. giaccio et al. vie naturali che, attraverso l’area di fdm, connette il versante tirrenico a quello adriatico. la scomparsa delle tracce archeologiche, a partire dall’inizio dell’he3, indicherebbe un significativo cambiamento nella localizzazione delle occupazioni nella piana di colfiorito o addirittura una definitiva interruzione della millenaria frequentazione di questa area strategica sullo spartiacque appenninico. ciò suggerirebbe che durante l’ois3, le modificazioni geo-ambientali associate agli hes condizionarono sensibilmente le strategie insediative dei gruppi paleolitici, probabilmente limitando o modificando la mobilità nelle aree montane più interne dell’appennino centrale. nel panorama delle ricerche in corso in questo ambito, le evidenze di fdm si inseriscono in un mosaico ancora nebuloso e in parte condizionato da approcci e modelli semplicistici, ma che nel complesso sembrerebbe indicare gli hes come potenziali importanti agenti nelle dinamiche interattive uomo-ambiente del pleistocene recente mediterraneo. ringraziamenti si ringrazia francesco fedele (università di napoli “federico ii) per la determinazione della fauna e le utili discussioni sugli aspetti paleoecologici umani. le analisi sedimentologiche hanno beneficiato di preziose osservazioni sul terreno di sabatino ciarcia (università di napoli “federico ii). il lavoro di ricognizione, scavo archeologico e documentazione fotografica è stato condotto con i contributi di fabio grossi, gianluca reddavide, simona rossell i , alessandro spera (università di roma “tor vergata”) e antonio todero (università di bologna). si ringraziano ernesto e luca santucci con i quali alcuni di noi (b.g. e m.r.) hanno piacevolmente condiviso due settimane di scavo e permanenza a fdm. desideriamo infine ringraziare giuseppe chiodi (soprintendenza archeologica delle marche) per il costante supporto fornito nel corso delle indagini sul terreno. bibliografia ahern j.c.m., karavanić i., paunović m., janković i. & smith f.h. (2004) new discoveries and interpretations of hominid fossils and artifacts from vindija cave, croatia journal of human evolution 46, pp. 25-65. allen j.r.m., brandt u., brauer a., hubbertens a.-w., huntley b., keller j., kraml m., mackensen a., mingram j., negendank j.f.w, nowaczyk n.r., oberhänsli h., watts w.a., wulf s. & zolitschka b. (1999) rapid environmental changes in southern europe during the last glacial period nature 400, pp. 740-743. allen j.r.m. & huntley b. (2000) weichselian palynological records from southern europe: correlation and chronology quaternary international 73/74, pp. 111-125. allen j.r.m., watts w.a. & huntley, b. (2000) weichselian palynostratigraphy, palaeovegetation and palaeoenvironment; the lago grande di monticchio, southern italy quaternary international 73/74, pp. 91-110. bar-yosef o. & pilbeam d. (2000) the geography of neandertals and modern humans in europe and the greater mediterranean peabody museum of archaeology and ethnology, cambridge. beck j.w., richards d.a., edwards r.l., silverman b.w., smart p.l., donahue d.j., hererraosterheld, s., burr g.s., calsoyas l., jull a.j.t. & biddulph d. (2001) extremely large variations of atmospheric 14c concentration during the last glacial period science 292, pp. 2453-2458. beer j., muscheler r., wagner g., laj c., kissel c., kubik p.w. & synal h.-a. (2002) cosmogenic nuclides during isotope stage 2 and 3 quaternary science reviews 21, pp. 1129-1139. bhere k.-e. (1989) biostratigraphy of the last glacial period in europe quaternary science reviews 8, pp. 25-44. blair t.c. & mcpherson j.g. (1994) alluvial fans and their natural distinction from rivers based on morphology, hydraulic processes, sedimentary processes, and facies assemblages journal of sediment. research a64, pp. 450-489. bocquet-appel j.-p. & demars p.-y. (2000) population kinetics in the upper palaeolithic in western europe journal of archaeological science 27, pp. 551-570. bond g., heinrich h., broecker w., labeyrie l., mcmanus j., andrews j., huon s., jantschik r., clases s., simet c., tedesco k., klas m., bonani g. & ivy, s. (1992) evidence for massive discharges of icebergs into north atlantic ocean during the last glacial period nature 360, pp. 245-249. bond g.c. & lotti r. (1995) iceberg discharges into the north atlantic on millennial time scales during the last glaciation science 267, pp. 1005-1010. bond g., wallace b., johnsen s., mcmanus j., labeyrie l., jouzel, j. & bonani g., (1993) correlations between climate records from north atlantic sediments and greenland ice nature, 365, pp. 143147. bown t.m. & kraus m.j. (1987) lower eocene alluvial paleosols (wilwood formation, northwest wyoming, usa) and their significance for paleoecology, paleoclimatology, and basin analysis paleogeography paleoclimatology paleoecology 34, pp. 1-30. cacho i., grimalt j.o., pelejero c., canales m., sierro f.j., abel flores j. & shackleton m. (1999) dansgaard-oeschger and heinrich event imprints in alboran sea paleotemperatures paleoceanography 14, pp. 698-705. calamita f., coltorti m., pierantoni p.p., pizzi a., scisciani v. & turco e. (1998) relazioni tra le faglie quaternarie e la sismicità nella dorsale appenninica umbro-marchigiana: l’area di colfiorito studi geologici camerti 14, pp. 177191 chlachula j. (2001a) pleistocene climate change, natural environments and palaeolithic occupation of the altai area, west-central siberia quaternary international 80-81, pp. 131-167. churchill s.e. & smith f.h. (2000) makers of the early aurignacian of europe yearbook physical anthropology 43, pp. 61-115. 245la risposta ambientale ed umana ... coltorti m., albianelli a., bertini a., ficcarelli g., laurenzi m., napoleone g. & torre. d (1998) the colle curti mammal site in the colfiorito area (umbro-marchean apennine, italy): geomorphology, stratigraphy, paleomagnatism and palynology quaternary international 47/48, pp. 107116. cortijo e., labeyrie l., vidal l., vautravers m., chapman m., duplessy j.-c., elliot m., arnold m., turon j.-l. & auffret m. (1997) changes in sea surface hydrology associated with heinrich event 4 in the north atlantic ocean between 400 and 600n earth and planetary science letters 146, pp. 29-45. dansgaard w., johnsen s.j., clausen h.b., dahljensen d., gundestrup n.s., hammer c.u., hvidberg c.s., steffensen j.p., jouzel j. & bond, g. (1993) evidence for general instability of past climate from 250-kyr ice-core record nature 364, pp. 218-220. d’errico f. & sánchez goñi m.f. (2003) neanderthal extinction and the millennial scale climatic variability of ois 3 quaternary science reviews 22, pp. 769–788. fedele f.g., giaccio b., isaia r. & orsi, g. (2003) the campanian ignimbrite eruption, heinrich event 4 and the palaeolithic change in europe: a highresolution investigation in: a. robock and c. oppenheimer (eds.) “volcanism and earth’s atmosphere”. agu geophysical monograph 139, pp. 301-325. finlayson c., fa d.a., finlayson g., giles pachecoc f. & vidal j.f. (in press) did the moderns kill off the neanderthals? a reply to the comments by d’errico and sánchez goñi quaternary science reviews. frezzoti m. & giraudi c. (1992) evoluzione geologica tardo-pleistocenica ed olocenica del conoide complesso di valle majelama (massiccio del velino, abruzzo) il quaternario 5(1), pp. 33-55. frezzotti m., narcisi b. (1996) late quaternary tephra-derived paleosols in central italy’s carbonate apennine range: stratigraphical and paleoclimatological implications quaternary international 3436, pp. 147-153. galadini f., colini, l., giaccio b., messina p., sposato a. (2003) persisting effects of the colfiorito (central italy) pleistocene paleolandslide in the land use planning: upper palaeolithic and proto-historical coexistence, antique-modern modifications environmental geology 43, pp. 621-634. gamble, c. (1999) the palaeolithic societies of europe cambridge university press, cambridge. giaccio b., galadini f. , messina p. , sposato a. (2004a) cicli di bond, heinrich events e variazioni ambientali nei sistemi di conoide alluvionale tardopleistocenici dell’italia centrale convegno aiqua “la geologia del quaternario in italia: temi emergenti e zone d’ombra”, roma, 2004. programma con riassunti, p. 120. giaccio b., di canzio e. & fedele f.g. (2004b) correlazione tefrostratigrafica e paleoambientale della sequenza “paleolitico medio/superiore” della grotta di castelcivita (italia meridionale) con la carota gisp2: implicazioni cronologiche, paleoclimatiche ed archeologiche convegno aiqua “la geologia del quaternario in italia: temi emergenti e zone d’ombra”, roma, 2004. programma con riassunti, p. 46. giraudi c. (1996) l’impronta del “younger dryas” e degli “heinrich events” nell’evoluzione climatica e ambientale dell’italia centrale il quaternario 9(2), pp. 533-540. giraudi c. & frezzotti m., (1997) late pleistocene glacial events in the central apennines, italy . quaternary research 48, pp. 280-290. giraudi c. & mussi m. (1999) – the central and southern appennine (italy) during ois 3 and 2: the colonisation of a changing environment – préhistorie européenne 15, pp. 113-121. gribchenko y.n. & kurenkova e.i. (1997) the main stages and natural environmental setting of late palaeolithic human settlement in eastern europe. quaternary international 41-42, pp. 173-179. grootes p.m., stuiver m., white j.w.c., johnsen s., jouzel j. (1993) comparison of oxygen isotope records from the gisp2 and grip greenland ice cores nature 366, pp. 552-554. jackson r.g. ii, (1978) preliminary evalutation of lithofacies models for meandering alluvial streams in: miall a.d. (ed) “fluvial sedimentology” can. soc. petrol. geol. mem. 5, pp. 543-576. kozlowski j.k. (1990) a multiaspectual approach to the origins of the upper palaeolithic in europe in: p. mellars (ed) “the emergence of modern humans. an archaeological perspective”, pp. 419438. edinburgh university press, edinburgh. hughen k., lehman s., southon j., overpeck j., marchal o., herring c. & turnbull, j. (2004) 14c activity and global carbon cycle changes over the past 50,000 years science 303, 202-207. laplace g. (1964) essai de typologie systématique annali dell’università di ferrara xv, suppl. ii, pp.1-79. mayewski p.a., meeker l.d., twickler m.s., whitlow s., yang q., berry lyons w. & prentice m. (1997) major features and forcing of high-latitude northern hemisphere atmospheric circulation using a 110,000-years-long glaciochemical series journal of geophysical research 102 (c12), pp. 26,345-26,366. meese d.a., gow a.j., alley r.b., zielinski g.a., grotes p.m., ram m., taylor k.c., mayewsky p.a. & bolzan j.f. (1997) the greenland ice sheet core project 2 depth-age scale: methods and result journal of geophysical research, 102(c12), pp. 26,411-26,423. messina p., galadini f., galli p., sposato a. (2002) quaternary basin evolution and present tectonic regime in the area of the 1997-98 umbria-marche sesmic sequence (central italy) geomorphology 42, pp. 97-116. miall a.d. (1988) architectural elements and bounding surfaces in fluvial deposits: anatomy of the kayenta formation (lower jurassic), southwest colorado sedimentary geology 55, pp. 233-262. miall a.d. (1996) the geology of fluvial deposits springer-verlag, berlin, heidelberg, pp. 582. miccadei e., barberi r. & cavinato g.p. (1998) la geologia quaternaria della conca di sulmona 246 b. giaccio et al. (abruzzo, italia centrale) geologica romana 34, pp. 59-86. mokhtari fard a. (2001) recognition of abrupt climate changes in clastic sedimentary environments: an introduction global and planetary change 28, pp. ix–xii. moreno a., cacho i., canals m., prins m.a., sánchezgoñi m.-f., grimalt j.o. & weltje g.j. (2002) saharan dust transport and high-latitude glacial climatic variability: the alboran sea record quaternary research 58, pp. 318-328. moro m., bosi v., galadini f., galli p., giaccio b., messina p., sposato a. (2002) analisi paleosismologiche lungo la faglia di m. marine (alta valle dell’aterno): risultati preliminari il quaternario 15, pp. 267-278. narcisi b. (1996) tephrochronology of a late quaternary lacustrine record from the monticchio maar (vulture volcano, southern italy) quaternary science reviews 15, pp. 115-165. prentice i.c., guiot j. & harrison s.p. (1992) mediterranean vegetation, lake levels and palaeoclimate at the last glacial maximum nature 360, pp.658-660. paterne m., kallel n., labeyrie l., vautravers m., duplessy j.-c., rossignol-strick m., cortijo e., arnold m. & fontugne m. (1999) hydrological relationship between the north atlantic ocean and the mediterranean sea during the past 15-75 kyr paleoceanography 14, pp. 626-638. roucoux k.h., shackleton n., abreu l., schönfled j. & tzedakis p.c. (2001) combined marine proxy and pollen analyses reveal rapid vegetation response to north atlantic millennial-scale climate oscillations quaternary research 55, pp. 128132. sánchez goñi m.f., cacho i., turon j.-l., guiot j., sierro f.j., peypouquet j.-p., grimalt j.o., shackleton n.j. (2002) synchroneity between marine and terrestrial responses to millennial scale climatic variability during the last glacial period in the mediterranean region climate dynamics 19, pp. 95-105. sánchez goñi m.f., turon j.-l., eynaud f. & gendreau s. (2000) european climatic response to millennial-scale changes in the atmosphere–ocean system during the last glacial period quaternary research 54, pp. 394403. silvestrini m., peresani m. & muratori s. (in stampa) frequentazioni antropiche allo spartiacque appenninico nella fase antica del paleolitico superiore: il sito di fonte delle mattinate (altopiano di colfiorito) atti xxxviii riun. sc. iipp. sinitsyn a. (2003) a palaeolithic ‘pompeii’ at kostenki, russia antiquity 77, pp. 9-14. stanistreet i.g. & mccarthy t.s. (1993) the okavango fan and the classification of subaerial fan system sedimentary geology 85, pp. 115133. stuiver m., reimer p.j., bard e., beck j.w., burr g.s., hughen k.a., kromer b., mccormac g., van der plicht j. & spurk m. (1998) intcal98 radiocarbon age calibration, 24,000-0 cal bp radiocarbon 40, pp. 1041-1083. thouveny n., moreno e., delanghe d., candon l., lancelot y., shackleton n.j. (2000) rock magnetic detection of distal ice-rafted debris: clue for the identification of heinrich layers on the portuguese margin earth and planetary science letters 180, pp. 61-75. ton-that t., singer b. & paterne m. (2001) 40ar/39ar dating of latest pleistocene (41 ka) marine tephra in the mediterranean sea: implications for global climate records earth and planetary science letters 184, 645-658. trinkaus e., moldovan o., milota ş., bîlgăr a., sarcina l., athreya s., bailey s.e., rodrigo r., mircea g., higham t., bronk ramsey c., & van der plicht j. (2003) an early modern human from the pe?tera cu oase, romania pnas 20, 11231–11236. voelker a.h.l., sarthein m., grootes p.m., erlenkeuser h., laj c. mazaund a., nadeau m.-j. & schleischer m. (1998) correlation of marine 14 c ages from the nordic seas with the gisp2 isotope record: implications for radiocarbon calibration beyond 25 ka radiocarbon 40, pp. 517-534. voelker a.h.l., grootes p.m., nedeau m.-j. & sarnthein m. (2000) radiocarbon levels in the iceland sea from 25-53 kyr and their link to the magnetic field intensity radiocarbon 42, pp. 437-452. voelker a. (2002) global distribution of centennialscale records for marine isotope stage (mis) 3: a database quaternary science reviews 21, pp. 1185-1212. vrba e.s., denton g.h., partridge t.c. & burckle l.h. (1995) paleoclimate and evolution, with emphasis on human origins yale university press, new haven, ct. wagner g., beer j., laj c., kissel c., masarik j., muscheler r. & synal h.-a. (2000) chlorine-36 evidence for mono lake event in the summit grip ice core earth and planetary science letters 181, pp. 1-6. walker m.j.c., björck s., lowe j.j., cwynar l.c., johnsen s., knudsen k.-l., wohlfarth b. & intimate group (1999) isotopic ‘events’ in the grip ice core: a stratotype for the late pleistocene quaternary science reviews 18, pp. 1143-1150. watts w.a., allen j.r.m. & huntley b. (1996) vegetation history and palaeoclimate of the last glacial period of lago grande di monticchio, southern italy quaternary science reviews 15, pp.133-153. watts w.a., allen j.r.m. & huntley b. (2000) palaeoecology of three interstadial events during oxygen-isotope stages 3 and 4: a lacustrine record from lago grande di monticchio, southern italy palaeogeography, palaeoclimatology, palaeoecology 155, pp. 83-93. 247 ms. ricevuto l’8 giugno 2004 testo definitivo ricevuto il 12 ottobre 2004 ms. received: june 8, 2004 final text received: october 12, 2004 la risposta ambientale ed umana ... imp.coli& firenze: il suo impatto sull’evoluzione geomorfica dell’area massimo coli, francesco agili, gabriele pini & niccolò coli dipartimento di scienze della terra, università di firenze. riassunto: coli m., agili f., pini g. & coli n., firenze: il suo impatto sull’evoluzione geomorfica dell’area. it issn 0394-3356, 2004 in base ad una revisione critica dei dati di sottosuolo dell’area fiorentina (briganti et al., 2003; coli et al., 2004) è stato possibile addivenire ad una migliore ricostruzione della storia geologica plio-quaternaria dell’area ed ad una dettagliata conoscenza del suo assetto litostratigrafico di sottosuolo. queste nuove conoscenze, integrate con dati archeologici, storici e geomorfologici hanno portato a delineare gli schemi delle variazioni avvenute nel territorio fiorentino negli ultimi 20 secoli in seguito allo sviluppo della città di firenze nella piana alluvionale del medio valdarno. in questo lungo lasso di tempo lo sviluppo urbano della città e l’organizzazione del suo territorio hanno profondamente mutato quelli che erano i caratteri naturali dell’area, arrivando nei tempi attuali ad un “non paesaggio” urbano e territoriale tipico di tutte le grandi conurbazioni urbane. il paesaggio naturale all’epoca pre-romana vedeva la presenza dell’arno divagante lungo il margine meridionale e vaste aree palustri tra questo e la linea pedemontana settentrionale; solo i torrenti maggiori quali il mugnone ed il terzolle arrivavano a buttarsi direttamente in arno, gli altri si perdevano nella zone acquitrinose della piana. dal iii secolo a.c. la colonizzazione romana del territorio portò ad una bonifica pressoché totale dell’area tramite una fitta centuriazione orientata secondo le linee naturali del territorio (nw-se e sw-ne). la fondazione di firenze nel 56 a.c. ad opera di cesare per i suoi veterani avvenne su un alto topografico, chiuso tra l’arno il torrente mugnone ed il fosso scheraggio, in prossimità ed a controllo del principale guado, poi ponte, dell’arno sulla via di collegamento tra tirreno ed adriatico. firenze fu fondata con una struttura quadrata a castrum orientata secondo gli astri (nord-sud ed est-ovest). nel iii secolo d.c.. firenze aveva circa 50.000 abitanti e si era espansa fuori della cinta originaria con una forma pressoché pentagonale. dopo la crisi del basso medioevo (nel vi secolo la firenze bizantina aveva circa 1.000 abitanti!) a partire dal x secolo in avanti firenze si espanse con i borghi cresciuti lungo le principali vie di comunicazione. le tre cerchie di mura medioevali nacquero in progressione per comprendere e proteggere questi popolosi sobborghi. il risultato fu che la iii ed ultima cerchia di mura, costruita nel xiv secolo per una città di circa 100.000 abitanti ed in forte espansione, comprese di necessità un’ampia area pentagonale con incluse ancora molte zone agricole. questa perimetrazione fu superata solo nella seconda metà del xix secolo con firenze capitale e gli ampi progetti di urbanizzazione del poggi; negli ultimi 50 anni il forte sviluppo urbano ha “invaso” la piana in modo anonimo e aggressivo. la storia dell’impatto che questo sviluppo urbano di firenze ha avuto sul territorio può essere sintetizzata in alcuni punti essenziali: • bonifica in epoca romana delle aree palustri tramite la centuriazione; • reimpaludamenti di queste aree dopo la caduta dell’impero romano; • progressivo risanamento con bonifica di queste aree palustri a partire dal x secolo fino al xx secolo, ricalcando il reticolo di strade e fossi della centuriazione romana ancora memorizzato sul territorio; • deviazioni progressive dei vari corsi d’acqua prossimi alla città per essere usati come fossi murari; • rettificazione e canalizzazione, spesso copertura, dei corsi d’acqua; • rettificazione e arginamento dell’arno; • innalzamento dell’area del centro storico dovuta a sostruzioni e riporti; • impermeabilizzazione dell’intera area urbana con raccolta ed allontanamento diretto delle acque metoriche (ma questo non sembra avere influenzato la falda, controllata dall’arno); • obliterazione, nell’intera area urbana, dei caratteri naturali propri del territorio; • impronta reticolata della centuriazione persistente nell’imposta delle nuove periferie nella piana. abstract: coli m., agili f., pini g. & coli n., firenze: its impact on the landscape. it issn 0394-3356, 2004 in this study we have applied computer digital tools in order to show the changes of the florence country area in these last twenty centuries during the development of the city of florence, which was founded by julius caesar in 56 b.c. as colony for his veterans. florence was settled in accordance to the sun with a n-s and w-e street grid. florence was placed in an upraised area, between the arno river and the mugnone creek. that site allowed the control of the ford on the arno river, along the main path from the tyrrhenian coast to the adriatic one. at those times, the natural landscape, constituted by the wandering arno river and its tributaries as by marshlands and bogs, had already been changed by about two centuries of land use by romans. romans used to reclaim marshlands and bogs by means of “centuriazione”: squared grid of ditches and roads which deeply marked the country. traces of the centuriazione are still now visible, it drove and still drives the country and outskirt onsets. centuriazione was oriented according to the ground natural set (nw-se and sw-ne). the development of florence in roman time (in the iii century, florence numbered about 50.000 people, and dropped down to 1.000 in the bizantine age, vi century) and in the late medieval and renaissance time (when florence numbered about 100.000 habitants) was along the suburbs. suburbs where aligned along the outgoing roads and in order to enclose suburbs, the successive rings of the city walls gave to florence a pentagonal shape. the last city walls (xiv century) were mostly destroyed in the late xix century to give space to the ring of the avenues and to new quarters outside. these new quarters were set oriented parallel to the destroyed city walls. the new outskirts built in the last fifty years in the country surrounding florence were still settled according to the old trace of the centuriazione. during this time span, the creeks were put as moat and progressively diverted by their natural path until they were totally channelled or covered. the arno river was progressively rectified, narrowed and banked. after the fall of the roman empire, marshlands and bogs taken newly place which were progressively reclaimed since xi till xx century. in event of large floods the arno river course became as large as it used to be. parole chiave: firenze, geomorfologia, impatto, storia, olocene. keywords: firenze, geomorphology, impact, history, holocene. il quaternario italian journal of quaternary sciences 17(2/1), 2004, 195-211 196 m. coli et al. introduzione il “paesaggio” inteso quale visione omni comprensiva di un certo territorio non è un qualcosa di oggettivo, ma dipende soggettivamente dalla cultura e dalla sensibilità dell’osservatore, nonché dal suo stato d’animo. il “paesaggio” stesso è comunque frutto dell’evoluzione della natura e del lavoro dell’uomo sull’ambiente, pertanto una sua corretta lettura non può prescindere dal rapporto ternario uomo-natura-società e dalla stratificazione di testimonianze che tale rapporto ha lasciato nei secoli. nell’area fiorentina questa stratificazione è molto forte e trova le sue radici prima nell’evoluzione geologica e geomorfica degli ultimi milioni di anni (briganti et al., 2003), e poi, dalla sua fondazione quale municipio romano (56 a.c.), nella storia stessa dell’evoluzione storico-urbana della città di firenze, in cui però il forte accrescimento urbano degli ultimi 50 anni ha messo in crisi l’equilibrio ternario uomo-natura-società spostando la bilancia verso un paesaggio monotematico di tipo urbano. attualmente, per l’area fiorentina il requisito geografico-ambientale che per antonomasia contraddistingue un territorio (valle del medio valdarno, pianura dell’arno ...) è stato sostituito dall’elemento urbanistico legato alla conurbazione risultante dalla crescita e coagulazione di vari centri urbani in una nuova entità urbana-territoriale unica e complessa (fig. 1). questa forte impronta antropica rende difficile immaginare i luoghi come una volta dovevano essere, nel loro divenire naturale legato all’azione di erosione e deposizione dei vari corsi d’acqua che solcano il territorio, e che ne sono stati per millenni i veri plasmatori dell’aspetto geomorfico; l’area fiorentina ha così perso i caratteri naturali che altre aree della toscana, quali il casentino ed il mugello, hanno tuttora in parte conservato. allo stesso tempo però, per firenze, è ancora ben presente l’immagine della città incastonata tra le sue mura nell’ambito della media valle dell’arno (fig. 2), in un contesto territoriale ancora leggibile nei suoi caratteri naturali, splendidamente cristallizzato nei versi del foscolo: ... te beata, gridai, per le felici aure pregne di vita, e pe’ lavacri che da’ suoi gioghi a te versa appennino! lieta dell’aer tuo veste la luna di luce limpidissima i tuoi colli per vendemmia festanti; e le convalli popolate di case e d’oliveti mille di fiori al ciel mandano incensi. ugo foscolo, dei sepolcri (1807) fig. 2 immagine di firenze nel 1735 c. da bellosguardo (f.b. werner), in cui si può ancora apprezzare un equilibrato rapporto tra città e natura. a painting of firenze as it was in 1735 viewed from bellosguardo (f.b. werner) where one can appreciate the balanced relationship between the city and nature. fig. 1 immagine da satellite dell’area fiorentina; si può notare come la conurbazione urbana di firenze rappresenti ormai il principale carattere distintivo del territorio. satellite image of the fiorentina area; the urbanisation of firenze is the principle distinctive characteristic of this territory. il lungo percorso che ha portato il paesaggio a modificarsi in funzione dell’espansione urbana della città, è ricostruibile attraverso la storia dell’espansione stessa del centro abitato, quale causa ed effetto delle variazioni subite dal territorio. il riconoscimento e la definizione dei caratteri naturali propri di un territorio non è solo fine ad un accademico sviluppo delle conoscenze, ma ha dirette ed importanti ricadute sul contesto sociale ed organizzativo di una città, come drammaticamente dimostrato dalle ricorrenti piene d’arno, che in tali occasioni, superando il suo alveo antropico, si riprende quello che era il suo naturale territorio di divagazione. lo stesso vale per le aree ex palustri che in occasioni di piogge particolarmente intense e concentrate mostrano tuttora tendenza al ristagno delle acque, mettendo a dura prova i vari sistemi fognari, forse costruiti con una non completa conoscenza della situazione. medotologia il presente studio, volto a ricostruire le variazioni geomorfiche che lo sviluppo urbano di firenze ha comportato sul territorio, si è appoggiato ad un rilievo geomorfologico originale a scala 1:10.000 riguardante la distribuzione dei depositi superficiali antichi e recenti, delle forme fluviali, delle forme di versante ed antropiche; a cui è seguita una verifica della geomorfologia sia attraverso lo studio di foto aeree, sia tramite una ricognizione aerea eseguita ad hoc. la gran parte dei dati è stata ricavata dall’analisi critica di oltre 1.000 stratigrafie di sondaggio disponibili. tali stratigrafie hanno permesso di delineare nei dettagli l’assetto e lo sviluppo geologico recente dell’area fiorentina (briganti et al., 2003; coli et al., 2003a), parametri indispensabili per una corretta interpretazione del territorio. la ricostruzione geologica si è articolata nello sviluppo di modelli a più livelli, che hanno permesso la sovrapposizione dinamica dei vari corpi geologici presenti, permettendo una forte interpretazione geomorfico-evolutiva dell’intero sistema. di notevole interesse per questa ricerca sono risultati i dati ricavati dall’analisi del primo livello naturale presente nei dati di sondaggio, dati che hanno consentito la ricostruzione dell’assetto litostratigrafico di superficie (agili et al., 2004), portando all’identificazione di aree a depositi granulari identificate come paleo-alvei e di altre caratterizzate da depositi coesivi limoso-argillosi connesse a zone di esondazione o palustri, presenti nel territorio fiorentino dalla preistoria sino al giorno d’oggi. informazioni sul modellamento fluviale e sull’evoluzione urbana della città di firenze sono state ricavate anche da documenti storici, così come da antiche vedute e pitture, in cui vengono descritte le variazioni del corso del fiume arno e dei suoi maggiori affluenti, dovute sia alla dinamica del corso d’acqua stesso, che all’intervento antropico finalizzato alla difesa dalle piene ed al miglioramento della navigazione. partendo dalla cartografia digitale recente a grande scala (ctr in scala 1:10.000 e 1:5.000 e mappali in scala 1:2.000) è stato sviluppato un modello digitale 3d dell’area, dtm (con maglia di 10x10 m), sulla cui base georeferenziata sono state svolte elaborazioni per arri197firenze: il suo impatto ... vare a ricostruzioni virtuali del territorio fiorentino nella sua evoluzione geomorfica recente legata all’azione antropica sul territorio, sinteticamente riportate nell’allegata tav. i. inquadramento geografico il bacino di firenze-prato-pistoia si sviluppa in direzione nw-se per una lunghezza di 45 km ed una larghezza massima di 10 km ad un quota intorno ai 45÷50 m s.l.m.; è delimitato a nord dai monti della calvana (916 m s.l.m.) e dal gruppo di monte morello (892 m s.l.m.) ed a sud dalla dorsale del montalbano (627 m s.l.m.). la depressione morfologica, alimentata dai fiumi ombrone, bisenzio, marina, mugnone, arno e greveema da altri minori, è riempita da sedimenti fluvio-lacustri plio-pleistocenici e fluviali recenti che superano i 600 m di potenza nella zona di prato (capecchi et al., 1975a). tali depositi giacciono in discordanza sul substrato litoide, costituito da formazioni appartenenti alla falda toscana ed all’unità ligure di monte morello (abbate & sagri, 1970; boccaletti & coli, 1982) che affiorano anche sui rilievi di margine del bacino stesso. l’area in esame (fig. 3) comprende la dorsale di fiesole-monte rinaldi, le colline del cionfo e di san domenico, la pianura alluvionale del fiume arno e dei suoi affluenti in destra orografica (torrente affrico, fosso san gervasio, torrente mugnone, torrente pellegrino, torrente lastra, torrente terzolle, fosso del termine, ed altri minori), la zona è delimitata a nord dai rilievi arenacei di fiesole (350 m s.l.m.) e monte rinaldi (280 m s.l.m.), a sud dalle colline di monte alle croci (130 m s.l.m.) e di monte uliveto (90 m s.l.m.). attualmente gran parte dell’area, soprattutto la pianura costituita da alluvioni recenti, è fortemente urbanizzata ed industrializzata; il resto del territorio è interessato da insediamenti privati sparsi e da colture, in particolare dell’olivo e della vite. inquadramento geologico l’area oggetto del presente studio è collocata nel settore orientale del bacino di firenze-prato-pistoia (fig. 4); tale bacino si è individuato a partire dal pliocene superiore come depressione tettonica (dainelli, 1936; azzaroli & cita, 1967; merla et al., 1967) sede di sedimentazione fluvio-lacustre a partire dal pliocene (ambrosetti et al., 1978; bartolini & pranzini, 1979; 1981; 1988; bartolini et al., 1983; briganti et al., 2003) quando il fronte estensivo legato all’apertura del tirreno (elter et al., 1974; boccaletti et al., 1985; 1995), ha raggiunto la futura area fiorentina smembrando per mezzo di una serie di faglie normali ad andamento appenninico (nw-se), ed immergenti verso sw, l’edificio tettonico compressivo preesistente. la parte centro-settentrionale delle colline del cionfo e di san domenico (150 m s.l.m.), così come parte di quelle di bagno a ripoli, è costituita dai depositi continentali lacustri “villafranchiani” (dainelli, 1936; azzaroli & cita, 1967; merla et al., 1967; capecchi et al., 1977), mentre le restanti colline sono impostate 198 sulle formazioni rocciose che costituiscono il substrato litoide del bacino; la zona pianeggiante cittadina (45÷60 m s.l.m.) è costituita invece dalle alluvionali recenti del fiume arno e dei suoi affluenti. il substrato litoide affiora sui rilievi di fiesole e di monte rinaldi a partire da 150 m s.l.m. fino alle quote sommitali di circa 300 m s.l.m., con assetto a monoclinale immergente di valori medi (20÷30°) verso nord, ed è costituito dal macigno, membro modino (coli et al., 2003b) della falda toscana datato all’oligocene (ferrini & pandeli, 1982, cum bib); gli affioramenti delle colline di monte alle croci e di monte uliveto sono invece costituiti da formazioni appartenenti al supergruppo della calvana (formazione di sillano e pietraforte), riferibili al cretaceo superiore-eocene medio, spesso intensamente tettonizzati e caoticizzati (losacco, 1957; abbate & sagri, 1970; boccaletti & coli, 1982). la formazione della depressione tettonica con carattere endoreico, ha richiamato i principali corsi d’acqua antecedenti/sovrimposti (bartolini, 1992, fig. 6.6) alla struttura (torrente bisenzio, torrente mugnone, torrente greve), impostati sulla superficie di regressione del pliocene medio-superiore presente in gran parte dell’area nord-appenninica (bartolini, 1980; bartolini & pranzini, 1979; 1981; 1984), e caratterizzati da un notevole trasporto solido che in precedenza era scaricato nella pianura costiera pliocenica, nelle attuali zone di san casciano e montelupo (canuti et al., 1966; bartolini & pranzini, 1981) (fig. 5). tali corsi d’acqua così intercettati vennero a scaricare i loro materiali all’interno del neo-bacino fluviofig. 4 inquadramento geologico dell’area di firenze (modificata da briganti et al., 2003). depositi continentali: 1) alluvioni recenti, 2) “villafranchiano” fluvio-lacustre; unità liguri: 3) unità di monte morello, 4) complesso caotico, 5) corpi ofiolitici, 6) canetolo; falda toscana: 7) macigno. a geological sketch of the firenze area (modified from briganti et al., 2003). 1) recent alluvial deposits; 2) “villafranchian” fluvio-lacustrine deposits; 3) monte morello unit; 4) caothic complex; 5) ophiolitic bodies; 6) canetolo complex; 7) tuscan nappe. fig. 3 – attuale espansione urbana di firenze, da confrontare con fig. 2 per realizzare il forte incremento urbano degli ultimi due secoli (da touring club italiano). the present urban expansion of firenze, to be compared with fig.2 strong the large urban increment of the last two centuries. m. coli et al. 199 lacustre la cui evoluzione geologica recente (briganti et al., 2003) vede nel pleistocene una ripresa dell’attività delle faglie trasversali all’asse della depressione, faglie di maiano-bagno a ripoli e castello-scandicci, che causò il sollevamento dell’area fiorentina e la conseguente migrazione delle conoidi clastiche verso la zona depressa più occidentale corrispondente all’attuale area di casellina-cascine-careggi. da questo momento l’evoluzione del bacino si differenzia tra l’area occidentale, in cui le condizioni lacustri-palustri permangono fino ad un’epoca recente (dainelli, 1936; guazzone, 1971; capecchi et al., 1975a; 1975b; bartolini & pranzini, 1979; briganti et al., 2003), e l’area fiorentina sollevata, in cui si instaurano condizioni di erosione e deposizione fluviale, ad opera del fiume arno e dei suoi affluenti. in quest’area si sviluppa un reticolo fluviale controllato dal livello di base dell’arno che sfocia nel bacino di prato-pistoia con un’ampia conoide clastica nella zona di casellina-cascine-osmannoro, a cui fanno da corona nella zona di casellina quelle dei torrenti greve ed ema e del torrente vingone, e nella zona di careggi quella del torrente terzolle (bartolini & pranzini, 1988; briganti et al., 2003). in questo periodo nell’area fiorentina si imposta una fase erosiva che porta l’arno ed i suoi principali affluenti ad incidere di circa 100 m i depositi fluvio-lacustri villafranchiani; segue una fase alluvionale con deposizione di sedimenti grossolani in corrispondenza degli alvei dei fiumi principali e di sedimenti più fini nelle zone di esondazione, in relazione all’innalzamento del livello di base del bacino di prato-pistoia per sua graduale colmata. la fase più recente è invece caratterizzata dalla divagazione del corso dell’arno che meandrizzando si è via via spostato da ne verso sw erodendo alla base le colline di san miniato e di bellosguardo, con deposizione di materiali prevalentemente grossolani in corrispondenza del suo alveo e di quelli dei suoi principali affluenti (torrente affrico, fosso san gervasio, torrente mugnone, torrente lastra, torrente terzolle), e con ripetuti impaludamenti di vaste aree, alcuni dei quali documentati in tempi storici (capecchi et al., 1975a; 1975b). il margine nord-orientale dell’area fiorentina è segnato dalla gradinata delle faglie normali di fiesole, con rigetto totale valutabile intorno ai 1.000 m, dei quali circa 200 post-smembramento della superficie di regressione pliocenica. fig. 5 schema dell’evoluzione geologica e geomorfologia dell’area di firenze dal pliocene (da briganti et al., 2003): a÷c) pliocene inferiore; d) pliocene superiore; e) pleistocene inferiore; f) pleistocene medio; g) pleistocene superiore; h) olocene. sketch of the geological and geomorphological evolution of the firenze area since pliocene (from briganti et al., 2003). a÷c) early pliocene; d) late pliocene; e) early pleistocene; f) middle pleistocene; g) late pleistocene; h) holocene. firenze: il suo impatto ... 200 parte di questa gradinata di faglie è attualmente sepolta sotto i depositi fluvio-lacustri ai piedi delle colline del cionfo e di san domenico, ma appare documentata dai dati delle perforazioni disponibili per l’area fiorentina che hanno raggiunto le rocce del paleoinvaso (briganti et al., 2003) e da indagini geoelettriche (guazzone, 1971; capecchi et alii, 1975a, 1975b); il margine sud-occidentale del bacino non sembra invece interessato da faglie. le faglie di castello-scandicci e di maiano-bagno a ripoli, responsabili dei movimenti differenziali dell’area fiorentina, sono attualmente sepolte al di sotto dei depositi fluvio-lacustri. per entrambe le faglie è stata ricostruita la posizione in base ai numerosi dati di sottosuolo disponibili (briganti et al., 2003). quadro geomorfologico l’assetto geomorfologico attuale dell’area fiorentina si è sviluppato dal plio-pleistocene in poi, in seguito alla formazione del bacino di firenze-prato-pistoia; una volta impostata la depressione tettonica si impostò un drenaggio di tipo endoreico (bartolini & pranzini, 1981; 1988; 1984), alimentato da brevi corsi d’acqua spesso a regime sporadico. i depositi alluvionali recenti dell’arno e dei suoi maggiori affluenti hanno dato luogo ad una estesa superficie pianeggiante tuttora in evoluzione, con quote intorno ai 45÷60 m s.l.m., e caratterizzata da una dinamica morfologica attiva, dove i processi di incanalamento delle acque, artificiali e naturali, sono responsabili delle modificazioni apportate al territorio. la pianura fiorentina è quindi di tipo alluvionale, e nei secoli è stata ed è tuttora soggetta a fenomeni di esondazione ed a fenomeni di erosione laterale dei corsi d’acqua, talora anche molto accentuati. l’origine di queste forme è dovuta in parte all’evoluzione naturale ed in parte all’attività antropica che a partire da tempi remoti ha interagito fortemente con l’ambiente naturale, indirizzandone e modificandone l’evoluzione morfologica. ancora nel xvi secolo l’alveo dell’arno nella pianura di firenze era notevolmente più largo di quello attuale con una configurazione divagante a rami intrecciati (fig. 6); durante gli ultimi secoli gli interventi antropici finalizzati alla difesa dalle piene ed al miglioramento della navigabilità interna, hanno contribuito a modificarne profondamente la configurazione morfologica ed il regime delle portate liquide e solide sia dell’arno che dei suoi affluenti. a b fig. 6 carte dell’arno a firenze xvi secolo secondo leonardo da vinci; a) a monte di firenze, b) a valle di firenze (da baratta, 1941) maps of the arno river in firenze during the xvi century drew by leonardo da vinci. a) upstream firenze; b) downstream firenze. m. coli et al. l’arno scorre attualmente nell’area meridionale della pianura, con una marcata linearità artificiale, ed un approfondimento dell’alveo in relazione ad interventi antropici, quali l’attività di estrazione di inerti dal letto del fiume e la costruzione di dighe; tali opere hanno influito sul bilancio tra portate liquide e solide causando una riduzione delle ultime, e di conseguenza una maggiore incisione dell’alveo ed una diminuzione della pendenza. nella pianura di firenze negli ultimi 150 anni, sono stati registrati dai 4 ai 6 m di approfondimento dell’alveo (canuti & tacconi, 1992; rinaldi, 1996). durante gli eventi di piena eccezionale, anche in epoca storica e recente (fig. 7), il fiume arno ha potuto comunque divagare nell’intera pianura incidendo i depositi lacustri “villafranchiani” e la coltre di alluvioni antiche, creando anche dei terrazzi fluviali con altezza di pochi metri (bagno a ripoli, bellariva, viale redi), nonché delle ripe d’erosione alle pendici dei rilievi di monte alle croci e di bellosguardo. il recente abbassamento dell’alveo dell’arno ha innescato sui suoi affluenti un processo di erosione regressiva e quindi di incisione dei depositi alluvionali antichi, delineando anche terrazzi fluviali. la pianura alluvionale, largamente impaludata, era in parte alimentata anche dagli affluenti secondari dell’arno, che ora risultano canalizzati o coperti per quasi tutto il loro percorso nella zona urbana, mentre le antiche aree palustri sono ora bonificate e intensamente urbanizzate. in epoca storica gli interventi di bonifica e di regimazione delle acque divaganti nella pianura avevano creato un complesso sistema di arginature artificiali, orientate secondo la centuriazione romana, che aveva la duplice funzione di contenere le piene e di isolare delle aree al fine di creare delle casse di espansione dove venivano catturate le acque di piena per farle decantare dal loro contenuto solido. la pianura alluvionale risultava pertanto articolata in settori distinti posti spesso a quote diverse, limitati da arginature o scoline. in epoca recente l’espansione urbana ne ha cancellato non solo la presenza, ma spesso anche la memoria stessa. l’intensa urbanizzazione ha alterato questo quadro uniformandolo in un unico contesto urbano che tende a cancellare le precedenti caratteristiche morfologiche e quindi la natura e distribuzione dei depositi alluvionali nell’area, creando invece delle nuove compartimentazioni artificiali per mezzo di rilevati, sottopassi e sbarramenti di costruzioni. nel complesso, al di là del mascheramento urbano attuale, l’arno ed i suoi maggiori affluenti presentano un’elevata dinamica con marcati processi di erosione 201 fig. 7 limiti delle più devastanti alluvioni d’arno a firenze, storicamente documentate. various delineated limits of the most devastating floods cause by the arno river in firenze that have been historically documented. firenze: il suo impatto ... lineare, che tendono a modificare rapidamente l’andamento delle sponde libere, talora arrivando anche a smantellare le opere di difesa. questa situazione di instabilità si aggrava in maniera particolare in coincidenza dei maggiori eventi alluvionali che aumentano l’entità dei dissesti. idrografia il reticolo fluviale è drenante verso sw secondo la massima pendenza, sul fronte della dorsale di monte ceceri-monte rinaldi. il torrente mugnone rappresenta con la sua linearità un tipico caso di antecedenza/sovraimposizione (bartolini, 1992) con mantenimento del suo corso durante il sollevamento della dorsale di monte cecerimonte rinaldi, in seguito all'azione della faglia di fiesole. per i torrenti terzolle e paleo-affrico è più probabile che il loro sviluppo sia legato ad un'azione di "aggiramento" del nucleo di macigno della dorsale di monte ceceri-monte rinaldi favorita dalla maggiore erodibilità dei terreni argillitici delle unità liguri affioranti alle due estremità di detta dorsale; questo anche in connessione con la presenza nelle due zone di disturbi tettonici, legati alle faglie di castelloscandicci e di maiano-bagno a ripoli. gli affluenti in destra d'arno, fatta eccezione per il mugnone, sono tutti di origine recente, lineari e poco gerarchizzati, impostati in erosione sui depositi fluvio-lacustri villafranchiani ed in stretta dipendenza con la faglia di fiesole sulla cui scarpata di faglia, testimoniata da faccette triangolari, si sono attestati in erosione regressiva degradandola; hanno tragitto breve, molto acclive nella parte a monte, carattere torrentizio, e sono attualmente canalizzati, deviati e coperti nell'area cittadina. nell’intera pianura alluvionale sono state individuate le tracce di antichi alvei fluviali attribuibili per la maggior parte all’arno; per il riconoscimento di tali forme sono stati utili alcuni elementi morfologici come i residui di un reticolo idrografico, lievissime differenze di quota, il colore (in foto aeree) generalmente più scuro dell’alveo rispetto alle zone circostanti, la disposizione dei campi e di alcune strade, in alcuni casi la toponomastica stessa. l’analisi da foto aeree (vedi anche conedera & ercoli, 1973) e da documenti storici, confortata dalla distribuzione granulometrica dei primi livelli superficiali, evidenzia una distribuzione dei paleoalvei che conferma un maggior soggiorno dell’arno sul fianco sinistro della valle; inoltre si evidenzia anche una progressione delle età passando da alvei più antichi vicino al bordo collinare settentrionale, ad alvei più recenti verso il centro del bacino dove intersecano l’attuale corso del fiume, rettificato artificialmente. elementi antropici l’impronta dell’uomo sul territorio fiorentino è stata lunga e pesante e ne ha spesso totalmente obliterato i caratteri naturali. le forme antropiche che primariamente interessano ora il territorio fiorentino sono il complesso delle costruzioni e della viabilità urbana, le opere di presidio costruite nei secoli per regimare l’arno ed i suoi affluenti ed i siti di estrazione di materiali da costruzione. in particolare, per i fini di compartimentazione del territorio e di controllo delle acque di esondazione rivestono importanza sia i vari sistemi di arginature e riempimenti, e talvolta anche di tombamenti, che hanno delineato l’attuale percorso dell’arno nell’area fiorentina, o che canalizzano e guidano i vari torrenti dell’area, sia l’insieme dei rilevati ferroviari e stradali che nell’ultimo secolo hanno accompagnato lo sviluppo della rete infrastrutturale in firenze. un altro elemento antropico di rilievo è costituito dai riporti “archeologici” legati alla stratificazione urbana su se stessa, che ha portato nell’area centrale fiorentina ad avere il piano topografico vergine a diversi metri sotto il piano viario attuale (fig. 8); altri riporti “archeologici”, anche se meno consistenti ed importanti, sono quelli legati alle grandi scelte urbanistiche del poggi, che nella seconda metà del xix secolo portarono all’abbattimento della terza cerchia di mura cittadine, ed alla creazione della cerchia dei viali ed all’interramento del vallo della fortezza da basso e quindi dell’espansione urbana “extra moenia” (fig. 9). 202 fig. 8 dati di controllo della superficie topografica vergine nel centro di firenze (soggiacenza della superficie topografica vergine in m dal piano campagna). data showing the virgin topographic surface of the center of firenze (depth in m) below the ground level. m. coli et al. 203 fig. 9 l’espansione urbana recente oltre la terza cerchia di mura, per l’attuale confrontare con fig. 3 (da fanelli, 1980). recent urban expansion pasing over the third ring of the city wall to be confronted with fig. 3 (from fanelli, 1980). 1861 1876 1923 1935 1896 1904 firenze: il suo impatto ... riporti antropici di ordine minore sono costituiti dai vari rilevati ferroviari e stradali che interessano l’area fiorentina e che in vario modo la compartimentano, obbligandone i flussi di spostamento urbano ed anche, in caso di alluvioni, di deflussi idraulici. parlando di riporti, altri elementi di rilievo, anche se di origine recente e dovuti alla sola attività antropica sono i due rilievi artificiali delle discariche di rsu della montagnola all’isolotto e di case passerini nella piana di sesto, nonché le “dune” antirumore a lato dell’autostrada a11 nella zona di peretola. evoluzione recente in base ad alcuni elementi osservabili sul terreno (direttamente, da foto aeree o da ricognizione aerea), ed alle informazioni ricavate da testimonianze storiche e da antiche mappe dell’area fiorentina che precedono l’intensa urbanizzazione subita nell’ultimo secolo, si è cercato di fornire un quadro sufficientemente preciso delle variazioni subite dal fiume arno e dai suoi principali affluenti nella pianura più prossima alla città di firenze (tav.i). le vicende geologiche pleistoceniche avevano portato l’arno a lambire i versanti meridionali del bacino, ma con un corso molto più ampio dell’attuale, con andamento divagante e ramificato. in tempi proto-storici l’arno presentava un alveo libero di divagare e di alluvionare nell’area fiorentina, mentre gran parte della restante pianura doveva essere a prevalente regime palustre, come testimoniato da ritrovamenti nella fascia di margine di pianura di sesto. la presenza di insediamenti italici del x secolo a.c. nella zona dell’attuale via del campidoglio, presumibilmente in corrispondenza di un passo perenne nella zona dell’attuale ponte vecchio (cfr. lopes pegna, 1974), dove poi era i l passo della via etrusca volterra-fiesole (borgi, 1977), nella zona della confluenza del torrente mugnone, depone a favore della presenza di un punto fermo intorno al quale si è poi andata sviluppando la sistemazione idraulica della pianura fiorentina e lo sviluppo stesso della città di firenze la centuriazione romana le prime sistemazioni morfo-idrauliche dell’area fiorentina sono di epoca romana, legate alla conquista dell’area da parte di roma ed al consolidamento della sua presenza nel territorio dopo le guerre puniche; le cronache (strabone; tito livio) riportano infatti che annibale arrivò a fiesole dopo avere attraversato le paludi d’etruria, da molti poste nel medio valdarno. successivamente roma bonificò tramite la centuriazione l’area di pianura. la centuriazione romana ha marcato profondamente il territorio creando un’ereditarietà ancora presente; tale centuriazione fu organizzata su un reticolo orientato secondo “naturae loci”, cioè nw-se ed sw-ne con i cardi ed i decumani orientati secondo l’andamento dell’arno e della pianura (marinelli, 1921) (fig. 10). nel 56 a.c. cesare dedusse per i suoi veterani la città di florentia (lopes-pegna, 1974); la nuova città fu costruita su base quadrilatera, in “terreno alquanto elevato e di buona esposizione, protetto dalle modiche alture circostanti e situato in posizione di facile difesa sul cuneo di confluenza formato dall’incontro delle acque dell’arno e del mugnone”, in prossimità di un facile e perenne passo dell’arno (lopes-pegna, 1974). questa localizzazione consentiva anche il controllo dell’incrocio tra le due principali via di comunicazione: una nord-sud ed una tirreno-adriatico, attive già in epoca etrusca (tracchi, 1971; borgi, 1977). la scelta del luogo era probabilmente legata anche al fatto che all’epoca romana l’arno era navigabile fino alla confluenza con l’affrico (lopes-pegna, 1974), ancora nel 825 vascelli vichinghi arrivarono fino a firenze, e gli equipaggi devastarono la badia fiesolana (davidsohn, 1907); in epoca medioevale ne è documentata la navigabilità solo fino a porto di mezzo a signa. a differenza della centuriazione, la città fu costruita con i decumani ed i cardi orientati secondo i punti cardinali; lo sviluppo di florentia fu tale che nel iii secolo d.c. fu necessario ampliarne le mura per proteggere i suoi circa 50.000 abitanti, molti insediati nei borghi extramura sviluppati lungo le principali vie di comunicazione convergenti in città. l’impatto della sistemazione territoriale morfoidraulica conseguente alle opere di centuriazione (regimazione idraulica e viabilità) operate dai romani, è stato 204 fig. 10 la città romana, la centuriazione dell’agro e le principali vie di traffico (da fanelli, 1980). the roman city, the “centuriazione” of the countryside and the pnciple roads (from fanelli, 1980). m. coli et al. dirompente per l’area fiorentina, marcandone per sempre l’organizzazione territoriale, a tal punto che anche i più recenti piani regolatori ne seguono le linee essenziali (fig. 11). solo l’espansione urbana pianificata dal poggi per firenze capitale rompe questo schema, prevedendo una città orientata secondo la iii cerchia muraria; ma al di fuori di quest’area persiste ancora l’organizzazione centuriata, cristallizzata nei mappali catastali. dal medioevo in poi in seguito alla caduta dell’impero romano ed al degrado delle condizioni sociali che ne seguì, l’alto medioevo fu un periodo di oscurantismo che comportò abbandoni e re-impaludamenti legati al forte calo demografico ed alla diffusa insicurezza sociale. nel vi secolo d.c., al periodo delle guerre tra bizantini e goti, firenze aveva solo un migliaio di abitanti, la cerchia muraria era attestata sui principali edifici romani dell’area centrale ed il territorio non più mantenuto si era naturalmente ampiamente re-impaludato; a questo contribuì anche la costruzione di pescaie a sbarramento del corso principale dell’arno, costruzione di pescaie vietata in epoca romana e confermata ancora nel vi secolo dall’imperatore teodorico (lopespegna, 1974). la ripresa della città di firenze, con nuove e sempre più ampie cinte murarie e recupero progressivo del territorio a funzioni antropiche, avvenne prima con carlo magno e poi con la contessa matilde, infine dopo l’anno mille firenze, eletta a libero comune, ebbe un rapido incremento demografico (circa 100.000 abitanti nel xv secolo) e sociale che comportò allargamenti urbani ed ulteriori recuperi e bonifiche delle funzioni sociali del territorio circostante. questa crescita urbana e di riantropizzazione del territorio, più intensa dal rinascimento, implicò la realizzazione di opere di sistemazione idraulica e di difesa dagli eventi di piena; pertanto, da allora, e specialmente nel xviii secolo, sono state apportate modifiche nel tratto urbano dell’arno e dei suoi affluenti, essenzialmente tramite rettificazioni e canalizzazioni (morozzi, 1762; targioni tozzetti, 1767; repetti, 1833-46; villani, 1845; carocci, 1907; marinelli, 1921; ciullini, 1924; mori & boffito, 1926; natoni, 1944; piccardi, 1958; losacco, 1962; mazzotta, 1998). l’arno le tracce più persistenti delle variazioni del corso dell’arno sono oggi riconoscibili in alcuni toponimi (pantano, pantanino, bisarni, isola, lame, ripa/ripoli, ...); sia a monte che a valle della iii cerchia di mura della 205 fig. 11 planimetria generale del piano regolatore generale di firenze dell’ing. bellincioni, 1915-1924 (da fanelli, 1980). a map of the general master-planof firenze by eng. bellincioni, 1915-1927 (from fanelli, 1980). firenze: il suo impatto ... città si sviluppavano varie isole fluviali ancora presenti nel xvi secolo e ben rappresentate nelle carte di leonardo da vinci (baratta, 1905; 1941) (fig. 6). tra queste le più importanti erano quelle del bisarno e dell’isola delle stinche a monte della città ed a valle quelle delle cascine dell’isola, nella zona oggi occupata dal parco, e di un’altra situata nella zona del quartiere dell’isolotto. in generale nelle vecchie rappresentazioni al di fuori della zona urbana, l’arno appare ripetutamente ramificato, a testimonianza della rettificazione artificiale del suo alveo imposta dalla progressiva espansione urbana; queste ramificazioni erano particolarmente diffuse nel tratto compreso tra il limite della zona urbana e la confluenza con il torrente greve, come testimoniato anche dalla distribuzione dei paleo-alvei nel tratto compreso tra porta san frediano e le cascine, su entrambi i lati del fiume. secondo le fonti storiche citate l’unificazione e la rettificazione del corso sarebbe stata effettuata durante il xvii secolo. anche i torrenti minori, ed in particolare i l torrente mugnone, appaiono ancora nel xv secolo liberi di divagare a monte delle mura cittadine, lungo le quali sono stati poi via via deviati come fossi lungo le mura (fig. 12). nonostante i numerosi interventi di sistemazione idraulica effettuati in epoche diverse sul corso dell’arno, gli eventi di piena e le conseguenti divagazioni del fiume in gran parte della pianura alluvionale, si sono ripetuti con grande frequenza fino ad oggi (tab. i); in tali eventi l’arno tende a rimpadronirsi di quello che era il sua naturale ambito di divagazione (losacco, 1967; principe & sica, 1967). tra le modifiche apportate all’arno nel tratto urbano è stato documentato anche lo spostamento progressivo verso valle della foce del torrente mugnone, a causa dei successivi ingrandimenti della città. il torrente mugnone, che prima della fondazione della città romana, sfociava probabilmente a valle del ponte vecchio, presso l’attuale ponte a santa trinita, fu poi canalizzato e deviato per alimentare i fossati delle varie cerchie di mura, finché ampliandosi ulteriormente la città nel xvi secolo venne unito al torrente terzolle, che prima aveva foce direttamente in arno nella zona delle cascine. sulla destra dell’arno un canale si staccava dal fiume delimitando un’isola in parte racchiusa entro le mura della terza cerchia; il canale in seguito venne deviato a costituire l’attuale fosso macinante, convogliando, in una via navigabile, una parte delle acque dell’arno dalla pescaia santa rosa fino verso san donnino ed oltre con un percorso ora in gran parte coperto. secondo un progetto di leonardo da vinci (baratta, 1905) tale via d’acqua doveva arrivare fino a pistoia e montecatini, superando il valico di serravalle con una galleria a chiuse multiple (!). numerosi dati archeologici entro l’area urbana fiorentina, hanno permesso di stabilire che il piano della città romana si trovava ad una profondità media di -4÷5 m rispetto al piano urbano attuale. per molti autori anti206 fig. 12 carta della catena (1472) , particolare, il mugnone, proveniente dalla gola tra monte rinaldi e san francesco di fiesole, divaga libero nella piana fuori di porta a san gallo (da fanelli, 1980). “carta della catena” (map of the chain) of the 1472; of particular notice is the mugnone creek which comes from the gorge between monte rinaldi and san francesco, and flows freely on the plane outside the area of porta san gallo (from fanelli, 1980). m. coli et al. chi (viviani, 1688; bellincioni, 1940) il rialzamento del suolo di firenze dall’epoca romana fino ad oggi, è attribuibile a fenomeni di alluvionamento; in realtà lo spessore di terreno interposto tra il piano romano e quello attuale non è costituito da alluvioni, ma essenzialmente da materiale di riporto e da antiche discariche di epoca medievale. solo nella zona più prossima all’arno, gli scavi eseguiti in via por santa maria hanno riportato alla luce uno strato di 50 cm di terreno alluvionale grossolano, deposto dal fiume al di sopra di un pavimento di marmo; si tratta comunque di un fenomeno locale, che non dimostra il completo abbandono della città, come ritenuto da alcuni. in base allo studio eseguito è stato possibile ricostruire, per periodi storici principali, le variazioni subite a seguito dell’attività antropica dai vari corsi d’acqua affluenti dell’arno nell’area fiorentina (tab. ii; tav. i). la falda idrica l’insieme delle alterazioni portate dallo sviluppo di firenze sul territorio e la canalizzazione e deviazione di gran parte della rete idrografica dell’area di sicuro ha abbassato la falda idrica portandola a pochi metri sotto il piano campagna, mentre in origine nelle aree palustri era a pelo o superiore al piano campagna. i dati disponibili sulla falda freatica dell’area fiorentina e sul suo andamento nel tempo (capecchi et al., 1975b; 1975c; 1977; guazzone & pranzini, 1979; pranzini & de rosa, 2003) evidenziano un livello piezometrico superficiale, posto a pochi metri sotto il piano campagna, sensibile alle variazioni stagionali ed ai grandi eventi pluviometrici localizzati, direttamente influenzato localmente dai prelievi da pozzi per usi vari (idropotabili, agricoli, industriali); negli ultimi 30 anni (1975-2002) il livello piezometrico risulta in risalita grazie al progressivo abbandono del prelievo da pozzi; l’andamento idrodinamico della falda mostra tuttora un deflusso sotterraneo legato all’assetto geomorfico naturale dell’area. nel complesso le acque del sottosuolo fiorentino (bencini et al., 1995a; 1995b; pranzini, 1997a; 1997b; gargini & pranzini, 1999) risultano ampiamente inquinate, salvo per situazioni puntuali locali. conclusioni riassumendo, l’impatto che la nascita e lo sviluppo urbano di firenze ha avuto sull’evoluzione geomorfica dell’area è sintetizzabile nei seguenti punti: 1. primariamente va rimarcato il nuovo e permanente assetto geometrico introdotto nell’area con la centuriazione romana, ancora cristallizzato e presente nelle ripartizioni catastali; 2. le originarie aree palustri sono state ormai quasi totalmente bonificate ed obliterate; rimangono due zone umide che ne preservano la tipologia: l ’oasi wwf di focognano e meglio ancora l’area di caccia protetta di sesto; 3. la progressiva espansione del contesto urbano ha portato alla obliterazione dei caratteri geomorfici propri dell’area, con loro totale alterazione e mascheramento; 4. l’idrografia dell’area risulta ormai totalmente regimata tramite canalizzazioni, rettificazioni, tombamenti e deviazione dei vari corsi d’acqua, e loro allontamento dall’area urbana; 5. l’area urbana è quasi totalmente impermeabilizzata con intercettazione delle acque meteoriche, loro convogliamento nel sistema fognario e loro allentamento dall’area urbana tramite l’idrografia deviata di cui al punto 2; 6. la superficie topografica naturale è stata alterata tramite riporti e accumuli antropici; 7. attualmente il territorio si presenta artificialmente compartimentato tramite la creazione di rilevati che interferiscono con il naturale deflusso delle acque di superficie. tutto quanto sopra espresso è ordinariamente valido nel contesto ambientale normale, ed in genere non ha grossi impatti nell’attività antropica corrente, ma viene sconvolto dalla periodica occorrenza di eventi naturali di ordine superiore quali le ricorrenti piene secolari dell’arno, che in queste occasioni tende a riappropriarsi del suo “alveo naturale” alluvionando ampiamente l’area urbana. 207 tab. 1 le alluvioni storiche dell’arno a firenze dal 1177 al 1966 (dati da autorità di bacino del fiume arno). historical floods of the arno river in the firenze area from 1177 to 1966 (data from the arno river bank authority). firenze: il suo impatto ... in conclusione si può affermare che nel complesso l’impatto che lo sviluppo urbano di firenze ha avuto sui processi e sull’assetto geomorfico naturali dell’area è stato rilevante, ma sostanzialmente non ha comportato l’insorgere di grandi negatività né per il territorio né per le attività umane, mentre al contrario i fenomeni naturali di ordine superiore, quali le ricorrenti piene secolari dell’arno, hanno un pesante impatto sulle attività antropiche, non rispettose delle necessità di spazio di tali fenomeni naturali. va al proposito rimarcato come la rettificazione generalizzata dell’alveo d’arno entro argini artificiali ristretti comporti alluvioni più catastrofiche. d’altra parte le precedenti massicce escavazioni in alveo e le dighe di levane e la penna, e gli effetti della rettif icazione, hanno determinato un cospicuo approfondimento dell’alveo che garantisce una accresciuta sezione idraulica. riferimenti bibliografici abbate e. & sagri m. (1970) development of the northern apennines eugeosinclinal sequence. sedimentary geology, 4 (3-4), 1970. ambrosetti p., carboni m.g., conti m.a., costantini a., esu d., gandin a., girotti o., lazzarotto a., mazzanti r., nicosia u., parisi g. & sandrelli f. (1978) evoluzione paleogeografica e tettonica nei bacini tosco-umbro-laziali nel pliocene e nel pleistocene inferiore. mem. soc. geol. it., 19, 573-580. agili f., coli., cecchi m., pini g. & rubellini p. (2004) firenze carta litotecnica, tav.i. comune di firenze, s.el.ca, firenze. autorità di bacino del fiume arno (1994) rischio idraulico nel bacino dell’arno. quaderni, 2. azzaroli a. & cita m.b. (1967) geologia stratigrafica, 3. la goliardica, milano. baratta u. (1905) leonardo da vinci negli studi per la navigazione dell’arno. boll. r. soc. geogr. it., ser. iv, vol. v, xlii, 739-921. baratta u. (1941) i manoscritti e i disegni di leonardo da vinci pubblicati dalla reale commissione vinciana sotto gli auspici del ministero della educazione nazionale. i disegni geografici conservati nel castello di windsor. roma, libreria dello stato. bartolini c. (1980) su alcune superfici sommitali dell’appennino settentrionale (prov. lucca e pistoia). geogr. fis. din. quat., 3, 42-60. bartolini c. (1992) i fattori geologici delle forme del rilievo. lezioni di geomorfologia strutturale. pitagora, bologna, 193 pp.. bartolini c. & pranzini g. (1979) dati preliminari sulla neotettonica dei fogli 97 (s. marcello pistoiese), 105 (lucca) e 106 (firenze). estratto da: contributi preliminari al la realizzazione della carta neotettonica d’italia, pubbl. n. 251, 1979. bartolini c. & pranzini g. (1981) plio-quaternary evolution of the arno basin drainage. z. geomorph. n. f. 40, dezember 1981, pp. 77-91. bartolini c. & pranzini g. (1984) l’antecedenza dei corsi d’acqua che attraversano la dorsale m.albano-poggiona nel quadro dell’evoluzione plio-quaternaria del valdarno. boll. soc. geol. it., 103, 1984, pp. 271-278. bartolini c. & pranzini g. (1988) evoluzione dell’idrografia nella toscana centro-settentrionale. boll. mus. st. nat. lunigiana 6-7, aulla (1986-1987), pp. 79-83. bartolini c., bernini m., carloni g.c., costantini a., federici p.r., gasperi g., lazzarotto a., marchetti g., mazzanti r., papani g., pranzini g., rau a., sandrelli f., vercesi p.l., castaldini d. & francavilla f. (1983) carta neotettonica dell'appennino settentrionale: note illustrative. boll. soc. geol. it., 101, 523-549. bellincioni g. (1940) il mistero della firenze romana. atti accad. colomb. di firenze, 1939-1940. bencinia., pranzini g. , santini f. & vaselli m. (1995a) i nitrati, i nitriti e i metalli pesanti nelle acque di falda di firenze. atti ii conv. naz. sulla protezione e gestione delle acque sotterranee. nonantola (modena), maggio 1995, quaderni di geologia applicata, 1, 1995, vol.3, 327-330. bencini a., cazzaroli g., gargini g. & pranzin g. (1995b) la qualité des eaux souterraines et sa relation avec la vulnerabilité à la pollution des aquifères. un exemple en toscane (italie): la plaine de florence . hydrogeologie 1995 n° 3, b.r.g.m. orléans (france), 59-72. boccaletti m. & coli m. (eds.) (1982) carta strutturale dell’appennino settentrionale. c.n.r., prog. fin. geodinamica, s.el.ca. firenze, 4 fogli. boccaletti m., coli m., eva g., ferrari g., giglia g., lazzarotto a., merlanti f., nicolich r., papanig. & postpischl d. (1985) considerations on the seismotectonics of the northern apennines. tectonophysics, 117, 7-38. boccaletti m., bonini m., moratti g. & sani f. (1995) nuove ipotesi sulla genesi ed evoluzione dei bacini post-nappe in relazione alle fasi compressive neogenico-quaternarie dell’appennino settentrionale. in: atti del convegno “rapporti alpiappennino”. polino r. & sacchi r. (editori). scritti e docum. accad. naz. delle scienze, 14, pp.229262. borgia. (1977) la rete stradale della toscana nei suoi caratteri attuali, nella sua evoluzione storica, nelle sue esigenze di sviluppo – parte i. l’universo, pp. 969-1032. briganti r., ciufegni s., coli m., polimeni s. & pranzini g. (2003) plio-quaternary evolution of the firenze area. boll. soc. geol. it.,122. canuti p., pranzini g. & sestini g. (1966) provenienza ed ambiente di sedimentazione dei ciottoli del pliocene di s. casciano (firenze). mem. soc. geol. it., 5, pp. 340-364. canuti p. & tacconi p. (1992) la dinamica fluviale dell’arno: profilo longitudinale. atti 76° riunione estiva della società geologica italiana, firenze, 21-23/9/1992, mem. soc. geol. it. 48. capecchi f., guazzone g. & pranzini g. (1975a) il bacino lacustre di firenze-prato-pistoia. geologia del sottosuolo e ricostruzione evolutiva. boll. soc. geol. it., 94, 1975, pp. 637-660. capecchi f., guazzone g. & pranzini g. (1975b) ricerche geologiche ed idrogeologiche nel sottosuolo della pianura di firenze. boll. soc. geol. it., 94, 1975, pp. 661-692. 208 m. coli et al. capecchi f., guazzone g. & pranzini g. (1975c) l'osservatorio freatime-trico sperimentale di firenze. geologia tecnica, 1975 (2), 65-71. capecchi f., guazzone g. & pranzini g. (1977) inquadramento idrogeologico dell’area di bagno a ripoli (firenze). boll. ing. prov. fi, 1, pp. 1-10. carocci g. (1907) i dintorni di firenze. firenze, tip. galletti e cocci, 1906-1907. ciullini p. (1924) di una raccolta di antiche carte e vedute della città di firenze. l’universo, v, 1924. coli m., agili f. & pranzini g. (2003a) geological setting of the firenze underground. 4th europ. congr. on reg. cartography and inf. system, bologna, 17-20/6/03. coli m., livi e., pandeli e. & tanini c. (2003b) pietra serena mining in fiesole: part ii – geological setting of quarry. j. mining sciences, 39, 56-62 conedera c. & ercoli a. (1973) elementi geomorfologici della piana di firenze dedotti da fotointerpretazione. l’universo, pp. 255-262. dainelli g. (1936) il bacino di firenze e il suo antico lago. melangé de geographie. tip. ricci, firenze, 13 pp. davidsohn r. (1907) storia di firenze. le origini. firenze. elter p., giglia g., tongiorgi m. & trevisan l. (1975) tensional and compressional areas in the recent (tortonian to present) evolution of the northern apennines. boll. geof. teor. appl., 17, 3-18. fanelli g. (1980) firenze. laterza, 296 pp. ferrini g. & pandeli e. (1982) depositi differenziati di conoide sottomarina nel macigno di fiesole (firenze). boll. soc. geol. it., 101, 77-84. gargini a. & pranzini g. (1999) pollution risk to groundwater beneath florence (italy) . “groundwater in urban environment. selected city profiles”, balkema, rotterdam, 131-138. guazzone g. (1971) ricerca sulle falde acquifere profonde tra firenze e pistoia. parte ia, indagine geologica. quaderni dell’istituto di ricerca sulle acque, 6, 1971, pp. 42-53. guazzone g. & pranzini g.(1979) correlazioni idrodinamiche fra la falda freatica di firenze, il fiume arno e gli apporti meteorici. geol. appl. e idrogeol., xiv (2), 299-327. guerrieri f. & mazzoni p. (1990) la fortezza da basso: un monumento per la città. ed. ponte alle grazie, 223 pp. lopes-pegna m. (1974) firenze, dalle origini al medioevo. del re, firenze, 459 pp. losacco u. (1957) costituzione geologica e franosità dei colli fiorentini a sud dell’arno. boll. soc. geol. it., 76, 1957, pp. 15-48. losacco u. (1962) variazioni di corso dell’arno e dei suoi affluenti nella pianura fiorentina. l’universo, luglio 1962, pp. 557-686. losacco u. (1967) notizie e considerazioni sulle inondazioni d’arno in firenze. l’universo, settembreottobre 1967, pp. 720-820. marinelli o. (1921) la carta topografica e lo sviluppo di firenze. rivista geografica italiana, 28, pp. 1838. mazzotta d. (1998) firenze, l’immagine urbana dal xiv al xix secolo. capone, lecce, 48 pp. merla g., bortolotti v. & passerini p. (1967) note illustrative della carta geologica d’italia. foglio 106, firenze. min. ind. comm. e art., roma. mori a. & boffito g. (1926) firenze nelle vedute e nelle piante. monsignori, roma, ristampa anastatica, 174 pp. morozzi f. (1762) dello stato antico e moderno del fiume arno, delle cause e de’ rimedi alle sue inondazioni. parte prima contenente la storia delle inondazioni. in firenze, stamp. g.b. stecchi, mdcclxii. natoni e. (1944) le piene dell’arno e i provvedimenti di difesa. firenze, le monnier, 1944. piccardi s. (1958) variazioni storiche del corso dell’arno. riv. geogr. it., 63, pp. 15-33. pranzini g. (1997a) indagine idrogeologica per un caso di inquinamento da solventi clorurati. quaderni di geologia applicata, 4, 1 (1997), 105-116. pranzini g. (1997b) geologia urbana di firenze: premessa (con m. boccaletti). geologia del bacino di firenze (con m. boccaletti e g. moratti). vulnerabilità e rischio di inquinamento della falda idrica (con a. gargini). atti conv. geologia delle grandi aree urbane. bologna, 5/5 non. 1997. 4993 pranzini g. & de rosa g. (2003) the florence groundwater and its historical variations. atti 4th european congress on regional geoscientific cartography and information systems. bologna, 17-20 june 3003, 593-595. principe i. & sica p. (1967) l’inondazione di firenze del 4 novembre 1966. i.g.m., 32 pp. repetti f. (1833-46) dizionario geografico fisico storico della toscana, contenente la descrizione di tutti i luoghi del granducato, ducato di lucca, garfagnana e lunigiana. voll. 6, firenze, 1833-46. rinaldi m. (1996) variazioni morfologiche recenti dell’alveo del fiume arno. atti conv. “la difesa dalla alluvioni”, firenze 4-5/11/1996. targioni tozzetti g. (1767) disamina di alcuni progetti fatti nel secolo xvi per salvare firenze dalle inondazioni dell’arno. in firenze, stamp. cambiagi, mdcclxvii. tracchi a. (1971) di alcune antiche strade dell’etruria settentrionale. l’universo, 337-368. villani g. (1845) cronica. firenze. villani v. (1688) discorso al serenissimo cosimo iii granduca di toscana intorno al difendersi de’ riempimenti e dalle correnti de’ fiumi. applicato ad arno in vicinanza della città di firenze. firenze, stamp. all’insegna del lion d’oro, mdclxxxviii. 209 ms. ricevuto il 26 aprile 2004 testo definitivo ricevuto il 7 fuglio 2004 ms. received: april 26, 2004 final text received: july 7, 2004 firenze: il suo impatto ... 210 tabella ii – variazione degli affluenti d’arno affluenti in destra d’arno gli affluenti in destra d’arno, a parte i torrenti terzolle, mugnone e mensola, sono impostati in erosione sui depositi fluvio-lacustri villafranchiani ed in stretta dipendenza con la faglia di fiesole sulla cui scarpata degradata si attestano in erosione regressiva. hanno tragitto breve, molto acclive nella parte a monte, e carattere torrentizio; attualmente sono canalizzati, deviati o coperti nell'area cittadina. il loro ciclo deposizionale ha alternato eventi ad alta energia con deposizione nella pianura fiorentina di sedimenti grossolani, ed eventi a bassa energia con sedimentazione fine, le loro conoidi possono essere localmente interdigitate e coalescenti tra di loro; da monte e valle sono. torrente mensola: sfocia in arno fra rovezzano e varlungo nei pressi della manifattura f.lli franchi, nelle carte del 1817 (losacco, 1962) mostra ancora un andamento tortuoso, ma ora è canalizzato e forzato nel suo alveo da ponte a mensola fino alla linea ferroviaria firenze-roma, a valle della quale è stato tombato; in epoca recente ha inglobato nel suo bacino idrografico, per cattura dovuta ad erosione regressiva, il bacino di vincigliatamaiano sottraendolo così al torrente affrico. torrente affrico: fino a metà del secolo scorso aveva un alveo libero e tortuoso (losacco, 1962), successivamente è stato raddrizzato e canalizzato, e recentemente (anni ’60 del xx secolo) tombato; da dati storici risulta che avesse un forte trasporto solido e che nel suo tratto meridionale, a valle di filarocca, fosse spesso in commistione con le divagazioni d’alveo dell’arno. a monte è stato privato per erosione e cattura regressiva, da parte del torrente mensola, del bacino di vincigliata-maiano. fosso di san gervasio: scende dai rilievi villafranchiani di san domenico, a partire da piazza edison è ormai coperto e canalizzato da tempo sotto viale volta, da dove, dopo avere raccolto anche le acque del fosso delle forbici è stato condotto dal poggi (2^ metà del xix secolo) a sfociare nel torrente mugnone alle cure all’altezza del ponte ferroviario delle linea faentina. dai dati storici (losacco, 1962) risulta avesse andamento tortuoso, con arginature pensili, con frequenti esondazioni limose e variazioni di corso; in origine prima di essere deviato lungo le mura cittadine, passava a monte dell’alto di piazza signoria come fosso scheraggio e sfociava in arno presso ponte vecchio nella zona di piazza castellani. torrente mugnone: risulta coevo allo sviluppo stesso del bacino di firenze; molta parte dei sedimenti fluvio-lacustri villafranchiani presenti nell'area fiorentina sono suoi depositi di conoide. durante il sollevamento dell'area fiorentina, il torrente mugnone ha mantenuto la sua linearità, reincidendo i suoi depositi prima, e rialluvionando successivamente. il torrente mugnone è di gran lunga il più importante tributario d’arno nell’area fiorentina, ha un ampio bacino imbrifero che porta a firenze le acque di monte senario e della valle delle caldine; raccoglie anche le acque del fosso della querce e del fosso del pellegrino. a valle della forra di monte rinaldi-fiesole il torrente mugnone, ancorché arginato e sistemato, conserva il suo alveo naturale fino circa alle cure, da dove è canalizzato in un alveo artificiale fino a sfociare in arno a valle delle cascine. in origine il suo corso si sviluppava secondo l’attuale direttrice di via san gallo-piazza san marco-piazza dell’unità-croce al trebbio e sfociava in arno verso il ponte a santa trinita (losacco, 1962). la superficie freatica ben evidenzia ancora il percorso originario del mugnone. nei secoli è stato poi deviato lungo le mura cittadine e nel xvi secolo, con la costruzione della fortezza di san giovanni (o da basso), venne condotto a circuire la fortezza per gli attuali viali strozzi-belfiore. varie relazioni storiche (vedi in: guerrieri & mazzoni, 1990) riportano suoi eventi alluvionali nella zona della fortezza per cui, sempre nel xvi secolo, fu deviato nel canale attuale per polverosa fino alle cascine, con l’accortezza di lasciare la sponda destra, verso i campi del romito-arcovata più bassa in modo da dare libero sfogo alle piene verso l’esterno della città; tale situazione idraulica si è preservata nei tempi fino ad oggi, indipendentemente dall’urbanizzazione che nell’ultimo secolo ha interessato quella zona di designata esondazione e che non ha previsto alcun intervento di bonifica idraulica. nei 20 anni passati dall'ultima ripulitura del suo alveo canalizzato (1982), il torrente mugnone ha deposto alcuni decimetri di ciottolami, in genere ben arrotondati e mediamente sferici, con diametro medio di circa 10 cm, a litologia prevalentemente carbonatica; durante tali lavori di ripulitura nella tratta ponte rosso-ponte fs del romito dalla zona di alveo fuori canaletta furono asportati circa 5 m di ciottolami sotto il p.c. e sostituiti con terreni limoso-argillosi, impermeabilizzandone così l’alveo. durante l'alluvione del 1992 le acque del torrente mugnone hanno raggiunto in tale tratta velocità dell'ordine di 4÷6 m/s. fosso di montughi: ha percorso breve, inciso nei terreni villafranchiani dal cionfo fino alla zona di via vittorio emanuele ii, da qui risulta tombato e canalizzato sotto tale strada fino al torrente mugnone. fosso dell’arcovata: scende dalle colline villafranchiane del cionfo, ha percorso breve ed effimero, ma in epoca storica ha causato vari alluvionamenti nella zona dell’attuale via circondaria dove è testimonianza del suo alveo l’attuale via dell’arcovata; agli inizi del secolo è stato tombato e canalizzato per via romagnosi e via pisacane nel torrente terzolle. m. coli et al. 211firenze: il suo impatto ... segue tabella ii – variazione degli affluenti d’arno fosso della lastra: questo fosso secondario scende da monte rinaldi, incidendo profondamente i rilievi villafranchiani del cionfo e di poggio secco; ormai canalizzato e tombato nell’area urbana, era tributario del torrente terzolle in cui confluiva nella zona santo stefano in pane. torrente terzolle: scende da careggi dove appare subito arginato e canalizzato fino a confluire nel torrente mugnone all’altezza del ponte di mezzo; prima delle sistemazioni rinascimentali sfociava nell’ampio alveo d’arno a valle della città nella zona del ponte alle mosse; in epoca preistorica alimentava ancora i paduli della zona del lippi, tre pietre ed olmatello-gondilaghi. affluenti in sinistra d’arno degli antichi affluenti di sinistra dell’arno, tralasciando i fossi secondari, rimane testimonianza solo di alcuni: fosso di gamberaia: scende dal pian dei giullari verso ricorsoli, è tombato e canalizzato lungo il viale michelangelo fino all’arno. fosso di carraia: scende da arcetri verso san niccolò, dalla zona dei serbatoi dell’acquedotto è tombato e canalizzato. fosso di san rocco: scendeva da san gaggio lungo la vallecola compresa tra le colline arenacee di boboli e bellosguardo, dove ora si sviluppano via de’ serragli e via maggio. originariamente lo sbocco in arno doveva trovarsi presso l’attuale ponte alla carraia, più tardi il corso d’acqua alimentò i fossati della seconda cerchia di mura della città; con la costruzione della terza cerchia di mura fu deviato lungo di essa fino all’arno; con il recente sviluppo urbano extra mura è confluito nel sistema fognario. fiume greve: proviene dal chianti, inizialmente sfociava nel bacino di firenze nella zona dell’antella dove, insieme al torrente ema, ora suo tributario, ha costituito un’ampia conoide nel bacino “villafranchiano” (capecchi et al., 1977; bartolini & pranzini, 1981). successivamente deviato dagli eventi geologici recenti dietro le colline di arcetri-bellosguardo sfociava, già con il torrente ema suo tributario, nella pianura nella zona di legnaia-scandicci, dove ha costituito un’ampia conoide. in seguito al totale alluvionamento della pianura, il fiume greve andava a sfociare in arno nella zona di mantignano-san bartolo a cintola; ora il suo tratto in pianura risulta regimato e rettificato. imp.marocco& il sottosuolo del castrum di grado (adriatico settentrionale): studi preliminari per una ricostruzione paleogeografica ruggero marocco1, franca maselli scotti 2, romana melis1 & ennio vio3 1dipartimento di scienze geologiche, ambientali e marine, università di trieste, via e. weiss, 2 34127 trieste. (e-mail: marocco@units.it; melis@units.it) 2soprintendenza per i b.a.a.a.a.a.s. del friuli venezia giulia, p.za libertà, 7, 32100 trieste 3dipartimento di biologia, università degli studi di trieste, via l. giorgeri, 9/10 34127 trieste. riassunto: marocco r., maselli scotti f., melis r. & vio e., il sottosuolo del castrum di grado (adriatico settentrionale): studi preliminari per una ricostruzione paleogeografia. (it issn 0394-3356, 2005). un sondaggio geognostico (12 m di profondità dal p.c.) eseguito sul sagrato della basilica tardo romana di santa maria delle grazie di grado ha permesso di ricostruire l’evoluzione paleogeografia del sottosuolo insulare. emerge che il centro fortificato dell’isola fu costruito (indicativamente a metà del iv sec d.c.) su un cordone litorale sabbioso, formatosi in seguito alla progradazione di un lobo deltizio di un fiume di notevole trasporto solido. l’analisi lito-biostratigrafica dei terreni attraversati attesta la presenza alla base del sondaggio di depositi paralici, che passano progressivamente a sabbie pelitiche di ambiente circalitorale franco, per poi ritornare alla condizione paralica iniziale. la successione descrive così un micro emiciclo trasgressivo-regressivo che si attua totalmente in ambito marino, in brevi lassi temporali e che non ha eguali nel circondario se non nel sottosuolo dell’attuale delta del f. tagliamento. i frammenti di manufatti ceramici individuati da -1,6 a -3,6 m e da -4,6 a -6,2 m di profondità dal l.m.m. attuale fanno supporre l’esistenza di uno scalo o di altre attività antropiche costiere che, almeno nel livello più superficiale, risalgono indicativamente a un periodo compreso tra il i sec. a.c. e il i sec. d.c., subito dopo la fondazione della colonia romana di aquileia (181 a.c.). il secondo orizzonte con resti archeologici, segnalato anche in un altro sondaggio prossimo a quello analizzato, induce a ritenere che anche prima della fondazione della celebre colonia romana l’area gradese fosse frequentata, grazie alla prossimità ad una foce di un fiume navigabile (paleo isonzo?). i risultati conseguiti permettono di ritoccare l’evoluzione costiera dell’area del litorale veneto-friulano fino ad oggi tratteggiata da r. marocco (1991) e di attestare l’importanza dei fiumi e delle loro continue diversioni nella definizione dell'assetto plani-topografico dell’antica linea di costa dell’adriatico nord-orientale. abstract:: marocco r., maselli scotti f., melis r. & vio e., the subsoil of the castrum of grado (northern adriatic sea): a preliminary palaegeographic reconstruction. (it issn 0394-3356, 2005). a 12 m deep exploration well drilled on the church-square of the palaeochristian basilica of santa maria delle grazie in grado allowed a reconstruction of the palaeogeographic evolution of the barrier island. the results indicate that the castrum of the island of grado was built around 4th century ad on the ridge of a prograding delta lobe of a river with intense solid transport. the litho-biostratigraphic analysis of the subsoil testifies to the presence of paralic deposits at the bottom of the well, which gradually pass to muddy sands of fully circumlittoral environment, and back to the original paralic environment. the sequence, in fact, represents a micro transgressiveregressive hemicycle entirely developed in a marine environment and has corresponding events only in the subsoil of the current tagliamento river delta. ceramic fragments recovered from -1,6 m to -3,6 m depth and from -4,6 to -6,2 m depth allow us to suppose the existence of a port or other human coastal activities (villas?) dating back, at least in the top interval, to the 1st century bc 1st century ad, soon after the foundation of the roman colony of aquileia (181 bc). the second interval with archaeological remains, which was discovered also in another well very close to the investigated one, let us believe that the area of grado was settled well prior to the famous roman colony foundation, due to its proximity to the outlet of a navigable river (palaeo isonzo ?). the results obtained from our data highlight a slightly different coastal evolution of the littoral area of veneto and friuli venezia giulia, already described by r. marocco (1991), and testify to the importance of ancient river diversions in reconstructing palaeocoastlines of northeastern adriatic sea parole chiave: : lito-biostratigrafia, ricostruzione paleogeografica, reperti archeologici romani, grado, alto adriatico. keywords: litho-biostratigraphy, palaeogeographic reconstructions, roman archaeological remains, grado, northern adriatic sea. il quaternario italian journal of quaternary sciences 18(2), 2005 135-146 1. introduzione le informazioni sul sottosuolo del castrum di grado e, più in generale, sul territorio ove ora si estende l’importante centro turistico adriatico, sono legate essenzialmente alle stratigrafie dei pozzi per acqua realizzati agli inizi del secolo scorso (tra i primi eseguiti nella bassa pianura veneto-friulana), rendicontate dai più importanti geologi dell’epoca (penk & brückner, 1909; sacco, 1912) e riprese poi da martinis (1953) e comel (1954). più recentemente, altri pozzi per acqua (corredati da stratigrafie generiche) si sono aggiunti ai primi e, oggi, il primo sottosuolo (fino a 10 m di profondità) è documentato da numerose prove penetrometriche statiche e sondaggi meccanici eseguiti a seguito del progressivo sviluppo urbanistico dell’ isola. l’insieme di questi dati permette di delineare, con apprezzabile precisione, la litologia e i caratteri geotecnici dei depositi incoerenti che formano il substrato dell’isola, senza però specificare in modo esaustivo la loro genesi. ciò è particolarmente avvertito per il centro storico, che presenta strutture abitative d’epoca romana e chiese paleocristiane, costruite su un cordone di sabbia litorale (il dosso di rena di biagio marin) che poggia su 136 r. marocco et al. depositi d’origine ignota. la conoscenza del sommerso dell’isola, tra l’altro, oltre alla notevole importanza ai fini geoarcheologici, assume estremo interesse paleogeografico anche per completare il quadro evolutivo della formazione della laguna di grado e del suo litorale, tratteggiato da marocco et al. (1984) e da marocco (1991). secondo l’ipotesi formulata da questi autori (desunta dall’analisi di sondaggi stratigrafici eseguiti nei dintorni dell’isola) il territorio si sarebbe formato per trasgressione del mare su una piana alluvionale, a seguito dell’innalzamento eustatico olocenico. anche autori precedenti e soprattutto brambati (1970) erano giunti ad analoga conclusione, essenzialmente sulla base di considerazioni morfologiche dell’assetto costiero (convessità del litorale) e da riscontri sedimentologici sui depositi e sul regime litorale attualmente in atto, arricchite da notizie storiche e archeologiche del territorio, attinte da de grassi (1950; 1952). la possibilità di verificare ulteriormente il quadro paleogeografico prospettato nei lavori precedenti e raffinarlo ulteriormente, colmando la lacuna locale rappresentata dal sottosuolo dell’isola d’oro, ci sono state offerte dalla soprintendenza per i beni a.a.a.a.a e storici del friuli venezia giulia che ha promosso l’analisi di un sondaggio geognostico, effettuato di fronte alla chiesa paleocristiana di santa maria delle grazie, spinto fino a 12 m di profondità dall’attuale piano di calpestio (figg. 1 b e c). 2. litostratigrafia dell’ immediato sottosuolo di grado la gran parte dei sondaggi eseguiti nelle vicinanze del centro storico di grado (dove, per ovvi motivi, le perforazioni nel sottosuolo sono molto rade), mostra una litostratigrafia definita, essenzialmente, da corpi sedimentari sabbiosi, disgiunti da livelli poco potenti di depositi più fini. segnatamente, gli strati di sabbia si rinvengono con una certa regolarità fra 3 e 7, 10 e 11 e 14 e 16 m di profondità dal piano campagna e sono intercalati da peliti più o meno sabbiose. questo abbastanza regolare assetto del substrato sedimentario è puntualmente interrotto in due sondaggi che palesano la presenza di livelli ghiaiosi. il primo (fig. 1b) è ubicato nella piazza duca d’aosta (uno dei primi pozzi per acqua, eseguito nel 1900 e in posizione immediatamente ad occidente del castrum), con la seguente stratigrafia dei primi 10 m (profondità riferite al piano campagna e al l.m.m. attuale quote u.i.m.a., ufficio idrografico del magistrato alle acque; + 1,6 m): piano campagna l.m.m. • 0,0 – 0,9 m +1,6 / + 0,7 m terreno rimaneggiato; • 0,9 – 2,3 m + 0,7 / 0,7 m torba mista a ghiaia; • 2,3 – 5,1 m 0,7 / -3,5 m sabbia fine, grigia; • 5,1 – 5,6 m 3,5 / 4,0 m ghiaia a grossi elementi; • 5,6 – 7,8 m 4,0 / -6,2 m argilla grigiastra mista a sabbia ed a ghiaia con inclusi resti ossei; • 7,8 – 9,0 m 6,2 / -7,4 m ghiaia; • 9,0 10,5 m 7,4 / -8,9 m argilla nerastra più o meno sabbiosa. di questo sondaggio si possiedono anche alcune preziose informazioni bio-stratigrafiche riferite da comel (1954): a 7,8 m (-6,2 m dal l.m.m.) si rinvenne il primo rappresentante della fauna marina (cerithiopsis), mentre a 10,5 m (-8,9 dal l.m.m.) furono ritrovati piccoli bivalvi a guscio sottile (loripes lactea) e cardium insieme a frammenti di gasteropodi (cerithium, cerithiopsis). più a settentrione, a poche centinaia di metri dall’estremità nord del centro fortificato si colloca il pozzo dell’ospedale, che manifesta ancora livelli di ghiaia nella seguente stratigrafia (sempre riferita al p.c. e al l.m.m. + 1,4 m; collocazione planimetrica in fig. 1b): piano campagna l.m.m. • 0,0 – 6,0 m +1,4 / -4,6 m terreno rimaneggiato, in prevalenza sabbioso, con resti di gusci di molluschi marini; • 6,0 – 6,5 m -4,6 / -5,1 m ghiaia mista a sabbia; • 6,5 – 9,0 m -5,1 / -7,6 m argilla torbosa; • 9,0 – 11,0 m -7,6 / -9,6 m sabbia con abbondanti frammenti di conchiglie. di là dalla variazione delle litologie presenti (da torbe a ghiaie) che palesano (se autoctone) una deposizione in ambienti con bruschi salti d’energia, rimane d’eccezionale importanza la presenza dei livelli ghiaiosi che risultano porsi in posizione più meridionale e meno profonda dell’intera area lagunare e in possibile continuità di sedimentazione con gli analoghi depositi rinvenuti a est di aquileia (paleoalvei del torre-natisone e isonzo; fassetta et al., 2003). in termini molto stringati, ammessa l’autoctonia delle ghiaie (che non è stato possibile analizzare), queste dovrebbero essere state deposte da un corso d’acqua di notevole trasporto solido. l’ipotesi dell’origine e della deposizione fluviale di questi sedimenti sembra essere suffragata da più indizi, tra cui la loro continuità in due sondaggi (posti a circa 300 m di distanza), e soprattutto dalla successione stratigrafica della terebrazione di piazza duca d’aosta. qui, a un deposito lagunare-litorale (con faune tipiche) succedono episodi di sedimentazione a ghiaie, intercalati da sedimenti “sporchi” (pelite, sabbia e ghiaia mescolate insieme), con una sequenza caratteristica di alveo fluviale in fase di occlusione o avulsione. l’unico sondaggio eseguito all’ interno del castrum (a sud del campanile; quota 1,7 m dal l.m.m.; fig. 1b) mostra, dopo ca. 3,5 m di sabbia e ghiaia con ciottoli e frammenti di cotto (riporto), sabbie medio-fini di colore grigio con frammenti conchigliari (da -1,8 a 5,3 m), poi sabbie debolmente limose, grigie, sempre con gusci rotti e minuti pezzi di cotto (da -5,3 a -9,3 m), alternanze di limi e sabbie fini, grigie (fino a -12,3 m) e, infine, sabbie medio-grosse, sempre grigie (da -12,3 a 15,3 m; comune di grado, 1995). al di fuori dell’abitato insulare (a ca. 2 km a occidente), alle spalle del banco dei tratáuri (s12 in marocco et al., 1984; fig. 1a), è stata appurata la contiguità dei terreni del sottosuolo con un corso fluviale capace di trasportare ghiaie. dall’analisi del sondaggio emerge una sequenza definita da peliti (-13,9 / -10,9 m), chiuse al tetto da sabbie medie, laminate (ambiente di sedimentazione continentale, posto in relativa vicinanza di un ambiente deltizio), seguite da un intervallo di sedimenti pelitici bioturbati (9,9 / -6,5 m) con all’interno dispersi ciottoli di rocce calcaree (di ambiente deltizio-lagunare) e da peliti con ciottoli di fango più 137ricostruzione paleogeografica ... fig. 1 il territorio della laguna e dell’isola di grado (adriatico settentrionale). a) ubicazione dei sondaggi s11 e s12. b) sondaggi stratigrafici eseguiti in prossimità del castrum (area in rigato): 1. s.m. delle grazie; 2. p.za duca d’aosta; 3. ospedale; 4. campanile; 5. torre quadrata del castrum. c) sezione trasversale della chiesa di s.m. delle grazie (la freccia indica l’ubicazione del sondaggio sul sagrato). the lagoon and the island of grado (northern adriatic sea). a) location of the wells s11 and s12. b) stratigraphic wells (1 to 5) drilled around the castrum (black lines): 1. ancient basilica of santa maria delle grazie; 2. piazza duca d’aosta; 3. hospital; 4. bell-tower; 5. square tower of the castrum. c) transversal section of the church of santa maria delle grazie (the projection of the well on the churchsquare is indicated by the arrow). a b c 138 specificatamente lagunari, troncate al tetto da una superficie erosionale. sopra questa superficie si depongono sabbie litorali e peliti sabbiose di retrobanco (situazione attuale). più a nord (sondaggio s11, fig. 1a) in un’isola della laguna di grado si sono rinvenuti 30 m di depositi continentali (totalità del sondaggio), erosi a 6,0 m di profondità da sabbie fluviali. questi dati portano a ritenere che ad occidente del castrum (ritenuto costruito nella seconda metà del iv sec. d.c.; cuscito, 1969) dovesse scorrere un fiume di notevole trasporto solido che, in seguito, si spostò verso oriente fino a lambire la costituenda città fortificata. ciò spiegherebbe alcuni problemi molto ribattuti, ma sostanzialmente ancora aperti, circa l’antico abitato di grado (vedi mirabella roberti, 1974-75; marchesan & marocco, 1994). secondo le ricostruzioni paleogegrafiche fino ad oggi prodotte, l’orientazione nw-se del castrum mal si combina con le direzioni delle presunte linee di riva dell’epoca (grossomodo e-w) e un centro fortificato in riva al mare di solito si allinea alla costa. un altro indizio, poi, viene suggerito dalla forma planimetrica del centro fortificato: la configurazione stretta ed allungata con dimensioni a trapezio (320 x 48-80 m), si adatta bene ad un lembo di terra proteso o falcato verso mare, come le sponde di un delta digitato. 3. il sondaggio della chiesa di s. maria delle grazie santa maria delle grazie (16,8 x 11,5 m; fig. 1c) è una delle più importanti chiese paleocristiane dell’italia settentrionale. edificata probabilmente alla metà del sec. v, fu restaurata e sopraelevata (di circa 1,1 m) dal patriarca elia (571-586 d.c.). anche se rinnovata più volte (gli ultimi lavori risalgono al 1920 e poi al ‘57), presenta un notevole degrado sia nelle opere murarie sia nelle strutture interne, tanto da richiedere urgentemente un ulteriore intervento di consolidamento e restauro. nell’ambito delle indagini odierne si sono eseguiti più sondaggi verticali a carotaggio continuo, di cui uno a raggiungere la profondità di 12 m dal piano piazzale (+1,4 m dal l.m.m; quota u.i.m.a.). le carote estratte (di cui si possiede una prima descrizione di cantiere) sono state ridefinite in termini lito-biostratigrafici, quindi campionate per la definizione dei caratteri sedimen-tologici, biologici e archeologici del sottosuolo. in sintesi, i depositi sotto l’anteportico della chiesa sono costituiti da sabbie mescolate in diverse proporzioni a peliti (classificazione di nota, 1958) e a ghiaie (riporto). sono presenti, inoltre, una variegata frazione archeologica costituita da frammenti di mattoni, laterizi e di intonaci e una componente organogena, definita da gusci di molluschi (malacofauna), di foraminiferi e di ostracodi (microfauna). 3.1 litostratigrafia prendendo in considerazione la sola frazione granulometrica priva delle ghiaie (depositi con ø < 2000 µm) si osserva nei campioni di sedimento una netta polimodalità, con picchi principali nel campo delle sabbie e secondari in quello delle pelit i (fig. 2). segnatamente, dal basso verso l’alto si riconosce una prima “unità” (informale) litostratigrafica (da -10,6 a 4,5 m dal l.m.m.), definita da una sequenza costituita da pelite molto sabbiosa, con contenuti di sabbie e pelite altalenanti che passa poi gradualmente, a circa -6,0 m, a sabbia pelitica, facendo assumere all’unità un tipico motivo deposizionale a energia crescente o negativo (coarsening upward). la sequenza è chiusa al tetto da un contatto netto planare. segue una seconda “unità” (da -4,5 a -0,3 m), caratterizzata sempre da pelite molto sabbiosa che diviene via, via più sabbiosa (sabbia pelitica) sempre con un motivo negativo. verso l’alto tra la sabbia pelitica si rinvengono resti di murature e quindi, attraverso un passaggio graduale, depositi più fini. la sommità della seconda “unità” è interrotta da uno scavo (testimoniato da un contatto netto, irregolare) riempito da materiale di riporto (“terza unità”, da -0,3 a +1,4 m). nell’insieme la frazione sabbiosa del sondaggio mostra, dal basso verso l’alto, dopo una fase altalenante, da -6,0 m di profondità una chiara tendenza all’aumento delle dimensioni medie dei granuli che segnala un graduale incremento dell’energia di trasporto dell’ambiente, anche se rimane in termini assoluti ad un livello relativamente basso (classazione moderata). il confronto di alcuni parametri statistici elementari (mz δi; folk & ward, 1957; fig. 3) dei depositi attraversati dal sondaggio con quelli dei sedimenti della spiaggia di grado, del litorale più prossimo a questa località e con le sabbie di piattaforma che caratterizzano i fondali centrali del golfo di trieste, mostra diversità significative che in altri lavori sono state attribuite a una genesi fluviale (gordini et al., 2002). in sostanza, sedimenti con caratteri analoghi a quelli del sottosuolo della chiesa gradese si rinvengono solamente in vicinanza di foci fluviali protette (attuale situazione dei fondali del delta dell’isonzo alla profondità -5 m) o alla bocca della laguna di grado (ancora profondità -5 m). in entrambi questi bracci di mare l’idrodinamismo ambientale viene determinato da correnti di trasporto fluviale o mareale che coesistono con l’energia di classazione del moto ondoso. ad analoga conclusione si arriva anche applicando il diagramma c-m di passega (1964) (fig. 4). l’elevata dimensione del parametro c rispetto ai diversi valori di m segnala l’esistenza di due famiglie di sedimenti: una a, costituita da depositi che si muovono essenzialmente per sospensione, ed una b, ove si mescolano sedimenti trasportati al limite tra sospensione e saltazione. nella prima area trovano spazio i depositi ubicati al letto e quelli al tetto del sondaggio, prima della superficie d’erosione antropica; nella seconda, tutti i rimanenti. 3.2 biostratigrafia l’analisi delle malacofaune è stata eseguita sulla frazione >2000 µm di tutti i campioni di sedimento prelevato; quella quali-quantitativa sulle microfauna, invece, sulla sola frazione sabbiosa (2000 ÷ 50 µm) dei campioni, escludendo quelli sommitali, chiara-mente rimaneggiati. 3.2.1 malacofaune lo scarso detrito conchigliare rinvenuto nel sondaggio ha messo in risalto: • la presenza di fibre vegetali che indicano una copertura dei fondali marini ad opera di praterie di fanerogame (alla sommità del sondaggio, -0,6 m, e al letto, -10,6 m); • la presenza da -3,5 m a -7,8 m di bittium reticulatum, r. marocco et al. 139 fig. 2 log stratigrafico e curve di frequenza dei depositi del sondaggio di s.m. delle grazie. stratigraphic log and grain-size frequency distributions of the deposits drilled by the well of s. maria delle grazie. ricostruzione paleogeografica ... 140 indicatore della biocenosi ad alghe fotofile che attualmente, in alto adriatico, si insediano da 3 a 6 m di profondità; • la comparsa di donax trunculus (a -0,6 e a -3,5 m), che è una specie componente la biocenosi delle sabbie fini ben calibrate (peres & picard, 1964), insieme a gibbula leucophaea, jujubinus striatus, rissoina bruguierei, triconia, cerithium vulgatum, aequipecten opercularis, lentidium mediterraneum (presenti in forma discontinua da -3,5 m di profondità, al letto del sondaggio) che indicano chiaramente un ambiente marino di acque basse; • alla associazione con le specie sopra elencate di loripes lacteus (da -3,5 a -7,8 m di profondità), lucinella divaricata (-6,6 m), chamelea gallina (-7,8 m), ostrea sp, che sono indicatori di un ambiente costiero riparato; • rari frammenti di glycymeris sp e di veneridae che suggeriscono la provenienza delle faune da sabbie costiere. in sintesi, seguendo lo schema di peres & picard (1964), la fauna a molluschi individuata nel sottosuolo della chiesa è rappresentativa della biocenosi delle sabbie costiere poste in prossimità di una bocca lagunare o di una foce fluviale. altre analisi malacologiche condotte su un unico campione di sedimento prelevato sotto la torre quadrata del castrum (piazza della corte, oggi b. marin; vedi fig. 1b, sondaggio 5), hanno evidenziato un’associazione tassonomica costituita da chamelea gallina, loripes lacteus, plagiocardium papillosum, divaricella divaricata, chama gryphoides, lentidium mediterraneum, donax sp (cfr d. semistriatus), glycymeris sp., bittium reticulatum e auriculinella bidentata. tutte queste specie sono tipicamente litorali (piano infralitorale) e costituiscono la biocenosi delle “sabbie fini di modo calmo” (peres & picard, 1964), rappresentativa dell’epifauna delle fanerogame (vedi bittium) e dell’endofauna del sedimento sciolto. a questa associazione si aggiunge auriculinella, un gasteropode polmonato che vive nel piano sopralitorale sabbioso e lentidium (indicativo della biocenosi delle sabbie fini superficiali) che segnala un dinamismo più marcato del fondo marino rispetto alle prime. nel complesso, l’associazione malacologia è quella tipica delle forme “spiaggiate”, dove l’unica specie in posizione fisiologica è data dal gasteropode polmonato. le faune presenti, anche se più numerose rispetto a quelle rinvenute nel sondaggio, portano a ritenere che i depositi sotto la chiesa e sotto il castrum siano molto simili e rappresentativi delle condizioni ambientali dell’attuale litorale di fronte a grado. 3.2.2 microfaune a) foraminiferi nei campioni di sedimento della carota sono presenti 48 specie di foraminiferi bentonici, appartenenti a 17 generi (tab. 1), con prevalenza di miliolina (27 specie) su rotaliina (21 specie). quattro specie sono state mantenute in nomenclatura aperta. in generale, si registra una diminuzione della ricchezza specifica spostandosi dalla parte centrale del sondaggio verso le estremità. più in particolare, alla base della perforazione (-10,6 m) si riscontra una limitata presenza di specie che aumenta soprattutto da -9,2 m di profondità e si mantiene più o meno costante fino a -4,7 m. dal successivo livello fino alla superficie del sondaggio il numero delle specie diminuisce drasticamente. per quanto riguarda il numero d’individui per specie, normalizzato in percentuale, si ritrova una netta predominanza di rotaliina, con percentuali di presenza che variano da 52% a 100%. i miliolina, sebbene presenti con un numero maggiore di specie, sono numericamente inferiori, con percentuali dei gusci variabili fino a 47,5%. inoltre, spostandosi dalla base del sondaggio verso la parte più superficiale, assistiamo ad una diminuzione, non solo della ricchezza specifica, ma anche del numero degli individui/grammo (tab. 1). fig. 3 diagramma mz-σi relativo ai sedimenti del sondaggio di s.m. delle grazie, messi a confronto con le sabbie di spiaggia, i depositi del litorale di grado e con le sabbie di piattaforma del golfo di trieste. mz vs. σi diagram of the sediments from the exploration well of s. maria delle grazie, compared with grado beach sands (squares) and littoral sediments (triangles), and sands from the continental shelf of the gulf of trieste (crosses). fig. 4 diagramma c-m dei depositi del sottosuolo della chiesa di s.m. delle grazie. campo a: trasporto per sospensione; campo b: trasporto per saltazione-sospensione. c-m diagram of the deposits from the subsoil of s. maria delle grazie. a: suspension transport field; b: saltation-suspension transport field. r. marocco et al. 141 tab. 1 frequenza percentuale dei foraminiferi rinvenuti nel sondaggio di s.m. delle grazie; gli asterischi indicano i taxa tipicamente paralici. distribution of foraminifers collected in the s. maria delle grazie borehole (in %); paralic taxa are indicated by an asterisk. specie prof. (m): 10.6 9.2 7.8 6.6 4.7 3.8 3.5 2.5 1.6 0.9 0.6 adelosina carinata-striata 0.0 1.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 adelosina dubia 0.0 0.0 0.4 1.9 1.4 0.0 2.5 0.0 0.0 0.0 0.0 adelosina elegans 0.0 0.0 0.0 0.0 0.9 3.4 0.0 0.0 0.0 0.0 0.0 adelosina ferussacii 0.0 0.0 0.4 1.9 3.2 0.0 0.0 0.0 0.0 0.0 0.0 adelosina longirostra 0.0 5.1 3.0 9.3 3.2 0.0 2.5 0.0 0.0 0.0 0.0 ammonia beccarii 24.1 7.0 24.6 6.0 15.4 13.8 15.0 46.2 53.8 0.0 5.0 ammonia inflata 41.0 5.1 7.5 12.6 14.9 3.4 22.5 7.7 15.4 0.0 40.0 ammonia papillosa 9.6 0.0 15.7 7.0 10.9 48.3 20.0 0.0 23.1 33.3 0.0 ammonia parkinsoniana 0.0 0.0 8.2 6.5 5.0 6.9 7.5 23.1 0.0 0.0 0.0 ammonia tepida* 6.0 9.5 0.7 2.8 0.9 0.0 0.0 0.0 0.0 0.0 35.0 aubignyna perlucida* 4.8 5.1 0.0 0.0 2.7 0.0 0.0 0.0 0.0 0.0 0.0 buccella granulata 2.4 0.0 1.1 1.4 2.3 3.4 2.5 0.0 0.0 0.0 0.0 cribroelphidium granosum* 8.4 3.8 2.6 5.1 1.8 0.0 0.0 0.0 0.0 0.0 0.0 cycloforina villafranca 0.0 0.0 2.2 3.7 3.6 0.0 0.0 0.0 0.0 0.0 0.0 discorbis sp. 0.0 3.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 elphidium aculeatum 0.0 0.0 0.7 0.5 0.9 0.0 0.0 0.0 0.0 0.0 0.0 elphidium gerthi 0.0 3.2 0.7 1.9 0.5 0.0 0.0 0.0 0.0 0.0 0.0 elphidium incertum 0.0 2.5 0.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 elphidium jenseni 0.0 0.0 0.4 1.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 elphidium macellum 2.4 0.0 2.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 elphidium maioricense 0.0 3.2 1.9 5.1 5.4 3.4 2.5 7.7 7.7 0.0 0.0 massilina gualtieriana 0.0 0.0 1.5 0.9 1.8 0.0 0.0 0.0 0.0 0.0 0.0 massilina secans 0.0 0.0 0.7 1.4 1.4 0.0 0.0 0.0 0.0 0.0 0.0 neoconorbina terquemi 0.0 0.6 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 nonion depressulum 0.0 4.4 0.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 nonion pauciloculum* 0.0 5.1 0.0 0.5 0.5 0.0 0.0 0.0 0.0 33.3 20.0 polymorphina sp. 0.0 0.0 1.9 2.8 0.5 0.0 7.5 7.7 0.0 0.0 0.0 quinqueloculina berthelotiana 0.0 0.6 0.0 0.0 0.5 0.0 0.0 0.0 0.0 0.0 0.0 quinqueloculina jugosa 0.0 0.0 1.1 1.9 1.4 0.0 0.0 0.0 0.0 0.0 0.0 quinqueloculina lata 0.0 0.0 0.7 1.4 1.8 0.0 0.0 0.0 0.0 0.0 0.0 quinqueloculina milletti 0.0 1.9 1.1 1.4 0.5 0.0 0.0 0.0 0.0 0.0 0.0 quinqueloculina parvula 0.0 1.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 quinqueloculina pygmaea 0.0 0.0 0.4 0.9 1.4 0.0 0.0 0.0 0.0 0.0 0.0 quinqueloculina seminulum 0.0 10.1 0.4 0.0 0.9 6.9 0.0 7.7 0.0 16.7 0.0 quinqueloculina sp. 1 0.0 1.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 quinqueloculina stelligera 0.0 10.1 0.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 quinqueloculina vulgaris 0.0 0.0 0.4 0.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 rosalina bradyi 0.0 0.0 0.4 0.5 0.5 0.0 0.0 0.0 0.0 0.0 0.0 rosalina obtusa 0.0 0.0 0.0 0.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 sigmoilina costata 0.0 1.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 siphonaperta agglutinans 0.0 0.0 0.4 0.0 0.9 3.4 7.5 0.0 0.0 16.7 0.0 siphonaperta aspera 0.0 0.0 11.6 12.1 10.4 3.4 7.5 0.0 0.0 0.0 0.0 spiroloculina sp. 0.0 0.0 0.4 0.0 0.5 0.0 0.0 0.0 0.0 0.0 0.0 triloculina marioni 1.2 1.3 0.7 1.9 0.9 0.0 0.0 0.0 0.0 0.0 0.0 triloculina schreiberiana 0.0 0.0 3.0 3.7 2.7 3.4 2.5 0.0 0.0 0.0 0.0 triloculina tricarinata 0.0 0.0 0.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 triloculina trigonula 0.0 11.4 1.5 1.9 0.9 0.0 0.0 0.0 0.0 0.0 0.0 si gl a ca m p io ne 10 (9 598 ) 10 (0 810 ) 9 (4 044 ) 8 (3 538 ) 7 (2 024 ) 6 (2 024 ) 5 (7 479 ) 4 (7 580 ) 3 (2 730 ) 3 (8 890 ) 2 (8 789 ) totale individui : 83 158 268 215 221 29 40 13 13 6 20 gusci/peso frazione sabbiosa : 14.3 27.9 39.3 25.4 53.8 4.2 4.7 1.3 1.0 0.5 3.2 ricchezza specifica : 9 23 36 30 33 11 12 6 4 4 4 ricostruzione paleogeografica ... i principali taxa rinvenuti in percentuale sono ammonia beccarii, a. inflata, a. papillosa, a. tepida, nonion pauciloculum, elphidium maioricense, quinqueloculina agglutinata, q. seminulum e siphonaperta aspera. segnatamente a. beccarii, a. inflata e a. papillosa sono presenti quasi costantemente lungo tutto il sondaggio, mentre gli altri si rinvengono in modo variabile lungo la colonna stratigrafica. la maggior parte dei taxa rinvenuti sono caratteristici del piano marino infralitorale come adelosina carinata-striata, a. dubia, a. ferrusacii, elpfidium spp., quinqueloculina jugosa, q. milletti, q. stelligera, q. vulgaris e triloculina trigonula. molte di queste specie possono vivere in substrati vegetati: buccella granulata (principalmente su cymodocea), elphidium aculeatum, e. jenseni, e. macellum (in foglie di cymodocea e posidonia), e. maioricense (su posídonia), massilina secans, rosalina bradyi (su posidonia), r. obtusa, quinqueloculina lata, triloculina marioni e t. trigonula. alcune specie fra quelle rinvenute, oltre che nel piano infralitorale, sono segnalate anche in quello circalitorale superiore, come adelosina elegans, ammonia beccarii, a. papillosa, a. inflata, cycloforina villafranca, elphidium incertum, sigmoilinita costata e triloculina marioni (cimerman & langer, 1991; sgarrella & moncharmont zei, 1993; fiorini & vaiani, 2001). alcune specie, inoltre, sono vincolate da particolari tipi di substrato: adelosína elegans e cycloforina villafranca a detrito; siphonaperta aspera ed elphidium incertum a sabbie fini; buccella granulata ed elphìdium macellum a sabbie fini con copertura vegetale; ammonia parkinsoniana e a. beccarii a sabbie; ammonia papillosa a sabbia e detrito fangosi; cribroelphidium granosum a sabbia fine e fango. importante è segnalare che diversi taxa rinvenuti nel sondaggio sono tipicamente caratteristici degli ambienti paralici lagunari, come ammonia parkinsoniana, a. tepida, aubignyna perlucida, cribroelphidium granosum e nonion pauciloculum e, in minor misura, adelosina elegans e quinqueloculina seminulum. da un punto di vista quantitativo, nel sondaggio indagato si osserva una netta dominanza delle specie tipicamente marine, in particolar modo nei livelli centrali (da -4,7 a -1,6 m), dove queste raggiungono anche valori del 100%. nella parte basale e in quella più superficiale, viceversa, aumenta la presenza percentuale delle specie tipicamente paralico-lagunari (tab. 1 e fig. 5). dall'analisi qualitativa e quantitativa dei foraminiferi riscontrati lungo la carota in esame è possibile quindi ipotizzare la sequenza dei paleoambienti che si sono avvicendati nel sottosuolo della chiesa di santa maria delle grazie. dal basso verso l'alto, questa si può così riassumere: • parte basale della carota (intervallo -10,6 / -9,2 m) che rappresenta un ambiente di dominio marino infralitorale con influenze d’acque più dolci o salmastre, testimoniate da una discreta percentuale di specie caratteristiche quali aubignyna perlucida, cribroelphidium granosum e nonion pauciloculum. oltre a queste si riscontrano anche rappresentanti dei taxa comunemente rinvenuti anche nei livelli sovrastanti (es. ammonia spp.) e specie in grado di tollerare condizioni di salinità variabile (es. quinqueloculina seminulum e q. stelligera) (amorosi et al., 1999). si tratta, presumibilmente, di un ambiente marino costiero poco profondo, come testimoninato dalla buona presenza di ammonia beccarii soprattutto nel livello di base. la scarsa diversificazione specifica è probabilmente imputabile all'instabilità ambientale data dall’ingresso d’acque a minor salinità; • nei livelli superiori, tra -7,8 m e -4,7 m di profondità, si registra un’evoluzione verso un dominio più francamente marino. la presenza di specie paraliche è inferiore rispetto al livello sottostante, mentre dominano le forme legate ad ambiente marino infralitorale, soprattutto definite da rappresentanti del genere ammonia e da miliolidae, qui particolarmente diversificate; rimane però la testimonianza di una leggera influenza da parte d’acque dolci. si può pensare si tratti di un ambiente anche a discreto idrodinamismo, soprattutto date le dimensioni e lo spessore di molti gusci, in particolare di adelosina longirostra e ammonia spp. sono molto diffusi anche i foraminiferi tipicamente epifiti: ciò potrebbe testimoniare anche la presenza di una copertura vegetale. l’associazione 142 fig. 5 andamento della frequenza percentuale dei principali gruppi di foraminiferi con la profondità nel sondaggio della chiesa di s.m. delle grazie. per ammonia spp. (costiere) si intende la somma percentuale di a. beccarii, a. inflata e a. papillosa. main foraminifer groups frequency log (%) in the s. maria delle grazie borehole. ammonia spp. indicates the percent sum of a. beccarii, a. inflata e a. papillosa. r. marocco et al. rinvenuta bene si confronta con l’associazione md definita da amorosi et al. (2004) nell’ambito dello studio paleoambientale del delta del fiume po. • dalla profondità di -3,8 m si assiste, come già precedentemente descritto, ad una diminuzione sia del numero delle specie sia degli individui presenti. drasticamente ridotta è anche la quantità degli epifiti. l'ambiente è ancora marino, ma mostra ancora una certa instabilità. il forte aumento percentuale di ammonia beccarii, a. inflata e a. papillosa, indicano ambienti molto costieri, con paleoprofondità valutabili nell’ordine di pochi metri, come suggerito da sgarrella & moncharmont-zei (1993). • la situazione muta nei livelli più superficiali (da -0,9 a -0,6 m), in quanto si ritorna ad una situazione simile a quella descritta per i livelli più profondi, in quanto aumenta nuovamente la componente paralica (anche se costituita esclusivamente da ammonia tepida e nonion pauciteoculum) e sono del tutto assenti i foraminiferi porcellanacei. il deposito costituito da sabbie scarsamente organogene, dove il contenuto di gusci varia da 0.5 a 3.2 individui/grammo, rende comunque difficile un'interpretazione certa, sebbene si sia propensi a interpretarlo come un ambiente spostato verso una spiaggia. probabilmente le forme presenti sono state oggetto di trasporto eolico o di episodi di mareggiata. b) ostracodi l’analisi qualitativa eseguita sulle ostracofaune presenti nel sondaggio ha permesso di distinguere i seguenti intervalli: • la base del sondaggio (-10,6 / -7,8 m) presenta una buona percentuale (circa 40%) di individui giovani e adulti di pontocytere turbida e rarissimi individui di loxoconcha ovulata, leptocythere sp. e cythereis sp., che generalmente vivono in ambiente infralitorale (montenegro et al., 1998; amorosi et al., 1999); • una parte centro-finale del sondaggio (da -6,6 a -1,6 m), con un intermedio di assenza di forme (da -4,7 a 3,8), dove si riscontrano sempre esemplari adulti di specie più specificatamente marine (semicytherura incongruens e neocytherideis fasciata, loxoconcha ovulata e pontocytere turbida) con una certa influenza d’acque salmastre, segnalata da cyprideis torosa; • la parte finale del sondaggio (da -1,6 a -0,6 m) con la sola presenza di cytheretta adriatica e loxoconcha ovulata, di ambiente infralitorale. in buona sostanza le ostracofaune confermano quanto appurato dalle precedenti indicazioni sedimentologiche e biostratigrafiche e cioè la presenza nel sottosuolo di grado di ambienti sedimentari tipicamente marini (infralitorali e marino franco) con una leggera influenza di acque salmastre imputabili alla vicinanza di un delta fluviale o di una bocca lagunare. 3.3 la componente archeologica dei sedimenti nel sondaggio sono presenti diffusi minuti frammenti di laterizi arrotondati, frammisti a scaglie calcaree, mattoni e pezzi d’intonaco fino a circa -6,0 m di profondità. i resti archeologici sono abbondanti nei primi metri (fino a -2,6 m dal l.m.m.) e poi diminuiscono in modo consistente procedendo verso il letto, rimanendo comunque presenti come frazione minoritaria del sedimento fino alla profondità indicata. in particolare, a -1,0 / -1,1 m dal l.m.m. si rinvengono un pezzo di mattone carotato dalla perforazione e grossi frammenti di cotto e d’anfora, insieme a scaglie di calcare grigio, con intonaci misti a sabbia. il tutto sembra indicare un livello antropico che potrebbe essere indicativo di resti di muretti a secco o di fondazioni. a circa -2,2 m, invece, sono presenti, ben inglobati nel sedimento, laterizi, pezzi di una piccola ciotola (i sec. a.c. ÷ i sec. d.c.) e frammenti di intonaco. questi dovrebbero rappresentare le prime testimonianze di un insediamento romano (ostium) nel territorio gradese (foto 1). anche in almeno tre metri di carota sotto questo livello si rinvengono rari frammenti minuti di laterizi, arrotondati e ben omogeneizzati nel sedimento sabbioso. analoga situazione è stata segnalata anche più a sud nel sondaggio del campanile (comune di grado,1995). al momento non sono disponibili datazioni radiometriche su questi depositi che, vista sia la tipologia di prelievo (carotaggio a secco con rivestimento del foro), sia l’appurata differenza granulometrica dei sedimenti e dei detriti antropici rispetto ai depositi superiori, sono da ritenersi in situ. la profondità di rinvenimento e l’ambiente marino dei sedimenti che li inglobano fanno ritenere che questi siano precedenti alla fondazione della colonia romana d’aquileia (181 a.c.) e risalenti, indicativamente, al periodo veneto. da registrare che questi tritumi si ritrovano specialmente nei depositi relativamente più sabbiosi, quelli che nell’ambiente marino-cosiero si posizionano più verso riva (spiaggia sottomarina) e che hanno subito un maggior rimaneggiamento dal moto ondoso. si spiega anche così la loro forma arrotondata e minuta. ipoteticamente, la provenienza di questi frammenti di cotto e laterizi può essere imputata a materiali persi da navi in rada in vicinanza di un attracco o porto commerciale che gravitava sull’antico litorale gradese. 4. considerazioni conclusive lo studio lito-biostratigrafico dei terreni attraversati dal sondaggio eseguito sul sagrato della chiesa di s. maria delle grazie di grado ha permesso di ricostruire i principali paleoambienti sedimentari del sottosuolo dell’isola fino alla profondità di -10,6 m dal livello del mare attuale. resti di manufatti ceramici inglobati in questi, poi, hanno consentito di abbinare all’evoluzione naturale del territorio la presenza antropica, determinata dalla frequentazione stabile o da una residenza vera e propria in terraferma (periodo romano a cavallo del i sec.) o da una frequentazione sporadica in mare, a ridosso della costa. ipotesi questa anche se non suffragata da evidenze consistenti, resa plausibile dalla funzione portuale di grado nell’antichità (gradus = scalo), dal ritrovamento al largo di grado di diverse navi tra cui una di età greco-italica (tortorici, 2000) e dalla presenza nel retroterra da venezia a trieste di numerosi manufatti greci, anche di pregevole fattura (soprintendenza del f.v.g., 1996-97). a completare questo quadro, si registra che diversi pescatori del posto segnalano nei fondali del golfo di trieste la presenza di manufatti litici (soprattutto ossidiane, scambiate per pezzi di carbone) che fanno almeno ipotizzare l’esistenza di una via commerciale transadriatica, utilizzata dall’età neo-eneolitica. 143ricostruzione paleogeografica ... sotto il profilo stratigrafico i depositi del sottosuolo gradese sono, dal basso verso l’alto (da -10,6 a -4,5 m dal l.m.m.), peliti molto sabbiose di ambiente marinolitorale, che passano gradualmente a sabbie pelitiche infralitorali (da -4,5 a -0,3 m) inglobanti al top resti di murature e quindi, gradualmente, a depositi più fini con accentuata bimodalità. la parte terminale del sondaggio (da -0,3 m a +1,4 m dal l.m.m.) è costituita da materiali vari (ghiaie, mattoni ecc.) che iniziano da uno scavo (testimoniato da un contatto netto, irregolare) riempito da riporti d’origine antropica, probabilmente connessi anche all’elevazione del piano di calpestio dell’isola a seguito dell’innalzamento del livello del mare da un lato e dalla subsidenza dall’altro (marocco, 2004). i dati sedimentologici, e soprattutto i log delle curve di frequenza dei sedimenti, disegnano nel sottosuolo, dopo una fase alternante basale, un progressivo innalzamento del fondale marino (che rimane in ogni modo sempre poco profondo e nell’ambito di una spiaggia sottomarina) che si attua con una sovrapposizione di depositi marini, quindi litorali e poi di spiaggia emersa. le analisi eseguite sulla malacofauna e microfauna a foraminiferi ed ostracodi si sono rivelate particolarmente sensibili per la definizione dell'evoluzione dei paleoambienti sedimentari. soprattutto in base alle microfaune a foraminiferi emerge che nell’ambito dell’ambiente marino si riconoscono, dal basso verso l’alto, momenti determinati da condizioni infralitorali, seguiti da altri più tipicamente circalitorali (parte intermedia del sondaggio), per poi ritornare a situazioni più prossime alla linea di riva (fase iniziale del processo). si evince, anche, che nelle associazioni microfaunistiche esiste una costante presenza di forme salmastre che palesano una relativa vicinanza alla costa o di un apporto d’acqua dolce fluviale. la situazione che si ricava dall’actuopaleontologia perfeziona la ricostruzione eseguita sulle sole basi sedimentologiche e fa risaltare un motivo stratigrafico determinato da un emiciclo trasgressivo-regressivo che si attua in ambiente marino poco profondo. ciò non ha riscontri nelle sequenze stratigrafiche appurate nel sottosuolo dei dintorni di grado, dove è presente una generale fase trasgressiva che interessa depositi continentali e, via, via, lagunari e marino-litorali, anche con sviluppi parziali o incompleti. in questa situazione di progressiva invasione del mare sulla terraferma, determinata dall’innalzamento del mare olocenico (e dalla subsidenza dei sedimenti sciolti), non contrapposta da una apprezzabile progradazione costiera, si inserisce la sequenza stratigrafica riscontrata a grado, che ha un valore locale. in realtà, una condizione abbastanza simile a quella qui individuata si trova sull’attuale delta del f. tagliamento (da -14,7 a -4,4 m di profondità; marocco, 1988) e viene determinata dal progressivo aggetto deltizio del fiume in un ambiente marino-litorale che si è attuato in circa 2.000 anni. come precedentemente detto, diversa è invece la situazione del sondaggio s12, poco ad est di grado, dove depositi lagunari e deltizi si sovrappongono da -9,9 a -6,5 m di profondità e di quello più a nord s11 (sempre in laguna di grado), in cui si rinvengono solamente sedimenti continentali (ca. 30 m) chiusi al tetto da depositi sabbiosi di genesi fluviale. 144 foto 1 resti di mattoni e ceramiche varie di epoca romana carotati nel sondaggio. il diametro del resto di mattone è 70 mm. brick and pottery remains of roman age drilled in the well. diameter of the brick remain is 70 mm. r. marocco et al. la sequenza stratigrafica individuata nel sottosuolo della chiesa di s.m. delle grazie rende manifesta la vicinanza di un delta fluviale e si allinea con la segnalazione di livelli di ghiaia sotto l’isola, posti a breve distanza dal sondaggio analizzato. con tutta probabilità l’emersione del “dosso di rena” è stata determinata dalla progradazione di un fiume che aveva messo foce a poca distanza dal castrum e che si è contrapposto all’innalzamento del mare olocenico (trasgressione versiliana). ciò modifica lievemente lo scenario raffigurato da marocco (1991) per il litorale gradese nella scansione temporale 4000 b.p. (fig. 6) e approfondisce l’insenatura tra i due lobi deltizi, sostenuti da differenti fiumi, a occidente e a oriente di grado. questa nuova situazione sposta leggermente più a nord la linea di costa dell’epoca, che si doveva ubicare all’interno dell’attuale laguna, ben prima della posizione del sondaggio s11 (isola di gorgo; fig. 1a), senza modificare di molto la posizione dell’antico fiume che sosteneva questo lobo. i risultati della presente ricerca aprono così una serie di scenari riguardanti la piana aquileiese e, specifica-tamente, l’annosa connessione tra i percorsi fluviali del natiso cum torre individuati a oriente di aquileia (fassetta et al., 2003) e quelli che gravitavano sul litorale gradese. sembra possibile, almeno su basi sedimentologiche – non confortate da dati cronologici – che il fiume (o i fiumi) che scorreva a est di aquileia in epoca romana abbia posto foce immediatamente a occidente del castrum gradese. ipotesi questa che verrà meglio indagata con ulteriori e mirate ricerche sul sottosuolo dei terreni intermedi a queste località. i pochi dati archeologici ricavati dal sondaggio eseguito sul sagrato della chiesa aprono un capitolo di storia non ancora scritto per questa parte terminale del grande emporio romano della colonia di aquileia. si è sempre ritenuto che lo scalo di grado (dal nome gradus) sia sorto in funzione della colonia romana al fine di garantire il controllo del mare prospiciente, sede dei più importanti traffici commerciali dell’alto adriatico. al di là da considerazioni talassocratiche che presumono sempre un’espansione delle popolazioni da mare a terra e non viceversa, i resti di costruzioni e i frammenti di ceramiche individuati nel sottosuolo palesano che il litorale era abitato almeno a partire dal i sec. a.c. ÷ i sec. d.c., dopo la fondazione della colonia romana. ma nel sondaggio sotto la chiesa di s. maria delle grazie si riscontrano minuti tritumi di ceramiche anche alla profondità di -4,6 / -6,2 m dal l.m.m., inglobati in depositi di un ambiente marino poco profondo. l’unico collegamento con possibili attività antropiche in questo contesto sembra poter essere ricercato nella rielaborazione del moto ondoso di materiali provenienti da navigli in rada, oppure dal trasporto litoraneo di materiale eroso dalla costa. non si esclude però una derivazione dalla terra via fiume come starebbero a dimostrare gli analoghi frammenti individuati sui letti dei fiumi che lambivano aquileia. nei primi due casi rimane implicita la presenza dell’uomo (sporadica o stanziale) in queste aree ben prima della fondazione della colonia romana. ciò appare plausibile se si tiene conto dei fiorenti insediamenti dei veneti nel retroterra (nella stessa aquileia pre-romana) e degli intensi scambi commerciali che via mare rifornivano queste popolazioni dell’alta italia. in questa cornice storica la costa nord adriatica doveva assumere un’importanza di posizione ben superiore a quella dell’immediato retroterra, collocazione questa degna di essere controllata attivamente, con insediamenti fissi. ma questo riguarderà il seguito della ricerca, che dovrà coinvolgere archeologi, storici e geologi in comunità d’intenti. ringraziamenti gli autori desiderano ringraziare il prof. n. pugliese per la determinazione degli ostracodi e per tutti i suggerimenti durante la stesura del testo e i neodottori e. lotti e a. toffoli, che con le loro rispettive tesine e tesi ci hanno affiancato in questa ricerca. grazie anche al dott. e. gordini dell’o.g.s. di trieste e al dott. t. quaia e c. landucci del disgam per le elaborazioni grafiche. il sondaggio analizzato in questo lavoro è stato eseguito dalla tecno futur services di modena, a seguito delle indagini preliminari per il progetto di restauro e di consolidamento della chiesa. la ricerca è stata condotta nell’ambito del progetto miur 60% “tutela, gestione e ripristino ambientale delle zone costiere”, coordinato da r. marocco. 145 fig. 6 – paleogeografia del litorale gradese 4.000 anni fa (modificata da fassetta et al., 2003): 1. presunti percorsi fluviali; 2. paleolinea di riva; 3. idrografia attuale; 4. attuale linea di riva; 5. paleolinea di riva proposta. palaeogeography of the grado littoral area at 4000 b.p. (modified after fassetta et al., 2003): 1. supposed palaeochannels; 2. palaeocoastline; 3. present hydrographic network; 4. present coastline; 5. paleaocoastline herein suggested. ricostruzione paleogeografica ... bibliografia albani a.d. & serandrei barbero r. (1990) i foraminiferi della laguna di venezia. università di padova, memorie di scienze geologiche, 42, 271-341. albani a.d., favero v. & serandrei barbero r. (1998) distribution of sediment and benthic foraminifera in the gulf of venice, italy. estuarine, coastal and shelf science, 46, 251-267. amorosi a., colalongo m.l., fasini g. & preti b. (1999) sedimentary response to late quaternary sealevel changes in the romania coastal plain (northern italy). sedimentology, 46, 99-121. amorosi a., colalongo m.l., fiorini f., fusco f., pasini g., vaiani s.c., & sarti g. (2004) palaeogeographic and palaeoclimatic evolution of the po plain from 150-ky core records. global and planetary change, 40 (1-2), 55-78. brambati a. (1970) provenienza, trasporto e accumulo dei sedimenti recenti nelle lagune di marano e grado e nei l itorali tra i f iumi isonzo e tagliamento. mem. soc. geol. it., 9, 281-329. cimerman f. & langer r.m. (1991) mediterranean foraminifera . slovenska akad. znanosti in umetnosti. opera acad. sc. art. slov. cl.4, hist. nat., 30, 118 pp. comel a. (1954) monografia sui terreni della pianura friulana. i) genesi della pianura orientale costruita dall’isonzo e suoi affluenti. n. ann. ist. chim. agr. sper., gorizia, 5, 228 pp. comune di grado (1995) studio geologico del territorio comunale per la valutazione di compatibilità con il p.r.g. l.r. 27/88. cuscito g. (1969) il nucleo antico della città di grado. appunti per un’indagine storico-bibliografica. aquileia nostra, xi, 143-182. de grassi v. (1950) esplorazioni archeologiche nel territorio della laguna di grado. aquileia nostra, xxi, 6-24. de grassi v. (1952) le rovine subacquee di san gottardo a grado. aquileia nostra, xxiii, 2736. fassetta g. a., carre m.b., marocco r., maselli scotti f., pugliese n., zaccaria c., bandelli a., bresson v., manzoni g., montenegro m.e., morhange c., pipan m., prizzon a. & siché i. (2003) the site of aquileia (northeastern italy): example of fluvial geoarchaeology in a mediterranean deltaic plain. geomorphologie: relief, processus, environnement. 4, 227-246. fiorini f. & vaiani s.c. (2001) benthic foraminifers and transgressive-regressive cycles in the late quaternary subsurface sediments of the po plain near ravenna (northern italy). boll. soc. paleont. it., 40, 357-403. folk r.l. & ward w.c. (1957) brazos river bar: a story in the significance of the grain size parameters. jour. sed. petr., 43, 224-237. gordini e., marocco r., vio e. (2002) stratigrafia del sottosuolo della “trezza grande” (golfo di trieste, adriatico settentrionale). gortania. atti museo st. nat., 24, 31-63. marchesan m. & marocco r. (1994) un dosso di rena… in: grado e la provincia isontina, 6, 19-24. marocco r. (1988) considerazioni sedimentologiche sui sondaggi s19 e s 20 (delta del f. tagliamento). gortania, atti museo st. nat., 10, 101-120. marocco r. (1991) evoluzione tardopleistocenica-olocenica del delta del fiume tagliamento e delle lagune di marano e grado (golfo di trieste). aiqua il quaternario, 4 (1b), 223-232. marocco r. (2004) le quote delle costruzioni romane e paleocristiane del castrum di grado in relazione al livello del mare. aquileia nostra, lxxv, 375-388. marocco r., pugliese n. & stolfa d. (1984) some remarks on the origin and evolution of the grado lagoon (northern adriatic sea). boll. ocean. teor. appl., 2, 11-17. martinis b. (1953) le formazioni quaternarie del sottosuolo di grado (gorizia). riv. ital. paleont. strat., 59, 3-19. mirabella roberti m. (1974-75) il castrum di grado. aquileia nostra, xlv-xlvi, 565 –574. montenegro m.e., pugliese n. (1996) autecological remarks on the ostracod distribution in the marano and grado lagoons (northern adriatic sea, italy). boll. soc. paleont. it., spec.vol. 3, 123-132. nota d.j.g. (1958) sediments of the western guiana shelf. thesis. mededel, landbouwhoge-school, wageningen, 98 pp. passega r. (1964) grain size representation by cm patterns as a geological tool. journ. sed. petr., 34, 830-847. penk a. & brückner e. (1909) die alpen in eizeitalter, vol iii, tauchnitz, leipzig. peres j.m. & picard j. (1964) nouveau manuel de bionomie benthique de la mer méditerranée. rec. trav. st. mar. endoume, 31, 137 pp. sacco f. (1912) geoidrologia dei pozzi profondi della valle padana (parte iii). ann. r. acc. agricoltura di torino, liv-lv, 387 pp. soprintendenza ai b.a.a.a.s. del friuli venezia giulia (1996-1997) prima dei romani. scoperte di preistoria e protostoria fra colline e mare. 32 pp. sgarella f. & montcharmont zei m. (1993) benthic foraminifera of the gulf of naples (italy): sistematics and autoecology. boll. soc. paleont. it., 32 (2), 145-264. tortorici e. (2000) un nuovo relitto di età repubblicana nel mare di grado. archeologia delle acque, 4, 91-98. 146 ms. ricevuto il 27 aprile 2005 testo definitivo ricevuto il 27 luglio 2005 ms. received: april 27, 2005 final text received: july 27, 2005 r. marocco et al. imp.carraro_giardino considerazioni sui criteri di correlazione tra unita’ stratigrafiche continentali quaternarie francesco carraro1 & marco giardino1 1dipartimento di scienze della terra, università degli studi di torino – francesco.carraro @unito.it riassunto: carraro f. & giardino m., considerazioni sui criteri di correlazione tra unità stratigrafiche continentali quaternarie. (it issn 0394-3356, 2004). nella letteratura geologica italiana sul quaternario continentale vengono spesso proposte correlazioni tra unità stratigrafiche l.s. (intese come corpi sedimentari o superfici di erosione) presenti in aree diverse, tra successioni di più unità stratigrafiche l.s. presenti in aree diverse o, infine, tra unità stratigrafiche s.l. ed “episodi” (intesi come intervalli di tempo, di durata molto variabile, durante i quale si sono instaurate e sono persistite determinate condizioni) climatici o tettonici. le correlazioni possono essere basate sulla litofacies, sulla posizione stratigrafica o su elementi cronologici di riferimento. dall’analisi dello sviluppo logico dei lavori in cui vengono avanzate proposte di correlazione si può ricavare che queste sono spesso supportate da uno o più di uno assunti. nel lavoro vengono analizzati criticamente tali assunti, giungendo alla seguente serie di considerazioni. nella maggior parte dei casi le successioni continentali sono decisamente lacunose, nel senso che non vi sono rappresentati tutti gli episodi sedimentari o erosivi in cui è consistita l’evoluzione geologica di cui rappresentano il riscontro; diverse unità di rango stratigrafico confrontabile possono corrispondere ad intervalli di tempo apprezzabilmente diversi. la durata dei diversi episodi climatici che controllano la sedimentazione o l’erosione può essere molto diversa. gli studi sulla tettonica recente ed in atto stanno dimostrando che lo stesso vale per le deformazioni sinsedimentarie. in contesti geodinamici caratterizzati da mobilità fra i fattori che controllano il sistema sedimentario continentale, oltre al ruolo “dinamico” dei fattori esogeni ed endogeni va aggiunto quello “statico” della diversa erodibilità delle formazioni rocciose via via esumate dall’erosione. quest’ultimo è responsabile della forte inerzia con cui il sistema risponde ai primi due gruppi di fattori. ne deriva la forte diacronicità che può caratterizzare nel loro sviluppo complessivo la base ed il tetto di un’unità sedimentaria o una superficie di erosione in tutta la sua estensione e la probabile confrontabilità di questa con la durata dei singoli episodi. viene poi esaminato il reale significato delle datazioni numeriche: queste possono essere affette da tre tipi di condizionamenti, il più importante dei quali è quello della effettiva associazione dell’elemento che si data con l’episodio che si intende datare. il secondo è rappresentato dalla possibile apertura del sistema chimico. il terzo condizionamento è quello, inevitabile, del margine di errore delle misure di laboratorio. da tutto quanto esposto sembra dovrebbe risultare sufficientemente documentato che correlazioni basate su un basso numero di datazioni sono molto deboli e discutibili. nel tentare delle correlazioni appare perciò opportuno spingersi, solo in presenza di un numero significativo di elementi di datazione, unicamente al livello o ai livelli che contengono gli elementi stessi e non all’intera unità sedimentaria, meno che meno alla successione in cui questa è compresa. qualsiasi altro tentativo resterà tale e come tale è opportuno sia presentato in eventuali lavori di sintesi. abstract: carraro f. & giardino m., a few remarks on the use of correlation criteria among quaternary continental stratigraphic units. (it issn 0394-3356, 2004). starting from a general definition of the term “correlation” (“demonstration of the lithological or chronological equivalence of two or more geological phenomena in different areas, by means of paleontological or physical evidence”) a discussion will be developed on the topic of stratigraphic correlations, which can be considered a “blind area” in the field of modern quaternary geology. in the italian geological literature concerning continental quaternary, correlation are frequently presented between stratigraphic units l.s. (meant as sedimentary bodies or erosional surfaces) of different areas, or between stratigraphic units s.l. and climatic or tectonic “episodes” (events meant as time intervals of various length, during which certain conditions started and persisted). correlations can in turn be based on lithofacies, stratigraphic position or chronological elements of reference. by analysing the logical development of scientific papers presenting correlation hypothesis, it can be drawn that correlations are often based on one or more than one of some arguments: a stratigraphic succession is an almost continuous record of geological evolution of an area, in the sense of a series of sedimentary bodies and erosional surfaces representing the whole group of sedimentary and erosional events taken place through time in that area; the time interval of formation of a stratigraphic unit can be compared by duration to the time interval of a climatic or tectonic event; the diacronicity (i.e. the difference between the minimum and maximum age) of the whole lenght of bottoms and tops of a stratigraphic unit s.l. is much shorter than time interval of a climatic or tectonic event; the stratigraphical units trace back to a single distinct climatic or tectonic event, in the sense of an event excluding the other; the available chronological elements are always characterized by absolute values and good resolution. in this paper arguments are critically analysed, and some consideration are derived. in the majority of cases, continental successions are quite full of lacunae, in the sense they do not represent a complete collection of sedimentary or erosional events describing the whole geological history of the area; stratigraphic units of different rank can correspond to quite different time intervals. also the duration of different climatic events controlling depositional or erosional processes can be quite different. up to date studies on recent and active tectonics are now showing the validity of the above considerations also for interpreting syn-sedimentary deformations. in geodynamic environments characterized by a mobility of factors controlling the continental sedimentary system, in addition to the dynamic role of exogenetic and endogenetic factors, a “static” control has to be considered, due to different erodibility of the through-time outcropping rock and sediment units. this latter is responsible for the strong inertia of the system response to the inputs from the first groups of conditioning factors. it derives a strong diacronicity along the whole lenght of bottoms and tops of sedimentary units and erosional surfaces; it also derives that stratigraphic units of the same rank can correspond to very different time intervals. in the paper field data and interpretations are presented and graphically illustrated to show how very different climatic or tectonic events can be testified by stratigraphic units of the same rank.then the real significance of numerical datings is analysed: these can be affected by three types of conditionings, the most important being the effective associations of dating elements to the events to be dated. the second is represented by the possible openings of the geochemical system. the third conditioning is the unavoidable errors of laboratory measures. from the above presented arguments it can be sufficiently documented that correlations based on a low number of dating elements are weak and open to challenge. in the tentative correlations is therefore suitable to go further only to the correlation of single sedimentary bodies containing dating elements, not to the whole sedimentary units, less than ever to the whole succession that comprises it. any other effort will remain an attempt and it is opportune to be presented as such in synthesis papers. parole chiave: correlazione, stratigrafia, continentale, forme, depositi, quaternario. keywords: correlation, stratigraphy, continental environment, landforms, deposits, quaternary. il quaternario italian journal of quaternary sciences 17(2/1), 2004, 293-300 294 f. carraro & m. giardino 1. introduzione fra le attuali “zone d’ombra” della geologia del quaternario vanno sicuramente annoverate le problematiche relative alla correlazione fra unità stratigrafiche continentali quaternarie. a partire da una definizione generale di “correlazione” come “la dimostrazione dell’equivalenza di due o più fenomeni geologici in aree differenti”1, equivalenza che può essere di diversa natura (litologica, cronologica, di posizione stratigrafica, ecc.) e supportata da vari tipi di evidenze (paleontologiche, fisiche, ecc.)2, verranno svolte alcune considerazioni sul tema che risulta di fondamentale interesse non solo per una corretta ricostruzione dell’evoluzione geologica di un’area, ma anche per una sua adeguata rappresentazione cartografica geologica di base e geotematica. nella letteratura geologica italiana sul quaternario continentale vengono spesso proposte correlazioni: tra “unità stratigrafiche s.l.” distribuite in aree diverse. nel testo che segue con l’espressione “unità stratigrafiche s.l.” si intenderanno, oltre ai corpi sedimentari, anche le superfici di discontinuità che ne segnano la base o il tetto; tra successioni di più “unità stratigrafiche s.l.” presenti in aree diverse; tra “unità stratigrafiche s.l.” ed “episodi” climatici o tettonici (intesi come intervalli di tempo, di durata molto variabile, durante i quale si sono instaurate e sono persistite determinate condizioni). le correlazioni possono essere basate su: litofacies; posizione stratigrafica; elementi di riferimento (cronologici o di altra natura). dall’analisi dello sviluppo logico dei lavori in cui vengono avanzate proposte di correlazione si può ricavare che queste sono spesso supportate da uno o più di uno della seguente serie di assunti, non espressi esplicitamente ma facilmente desumibili: a) una successione stratigrafica costituisce un record continuo dell’evoluzione geologica, cioè la successione di corpi sedimentari e di superfici di erosione (unità stratigrafiche s. l.) rappresenta il riscontro di tutti gli episodi sedimentari o erosivi succedutisi nell’area; b) l’intervallo di tempo corrispondente alla realizzazione di un’unità stratigrafica s.l. è confrontabile per durata con quello di un episodio climatico o tettonico; c) il grado di diacronicità (cioè la differenza tra l’età minima e l’età massima) della base o del tetto di un’unità stratigrafica s.l. nel suo sviluppo complessivo è molto minore della durata di un episodio climatico o tettonico; d) le unità stratigrafiche s.l. sono riconducibili o a un solo episodio climatico o a uno tettonico, in ogni caso distinti tra loro nel senso che si ammette che quando agisce uno non agisca l’altro; e) gli elementi cronologici disponibili sono caratterizzati da un valore assoluto e da un buon grado di risoluzione. nell’analizzare criticamente gli assunti sopra riportati verranno presentate una serie di considerazioni, di volta in volta documentate da dati ed interpretazioni tratte da diversi casi di studio. 2. presunta completezza delle successioni stratigrafiche si prenda ad esempio una successione costituita dal corpo a dalla superficie di erosione b dal corpo c e della superficie di erosione d: in una ricostruzione generica tale successione rappresenterebbe il record dell’episodio sedimentario a seguito dall’episodio erosivo b, seguito a sua volta dall’episodio sedimentario c seguito infine dall’episodio erosivo d. come già ricordato, si tende cioè a considerare una successione di corpi sedimentari e di superfici di erosione come il riscontro di tutti gli episodi sedimentari ed erosivi succedutisi in una determinata area, anche se ci si rende conto della presenza di lacune che possono elidere parte degli stessi. a prescindere dal fatto ben noto che le successioni continentali presentino per loro natura lacune sedimentarie, la storia evolutiva ricostruita dalle successioni continentali quaternarie documenta che l’assunto “semplicistico” di cui sopra non sempre si verifica. si veda ad esempio la fig. 1: i numeri indicano gli episodi sedimentari o erosivi ed i corpi o le superfici corrispondenti. le diversi tonalità di grigio aiutano a contraddistinguerli. si notino le superfici di erosione di rango inferiore all’interno dei singoli corpi sedimentari che, assieme a quelle di rango maggiore, testimoniano gli episodi erosivi conservati. dall’esame della fig. 2 si deduce che naturalmente non è possibile una correlazione a priori tra una successione stratigrafica ed una successione di “episodi”. dall’evoluzione reale della colonna stratigrafica si osserva che nella successione stratigrafica finale mancano completamente i termini corrispondenti agli “episodi” 2, 3, 4 e 5: 3. presunta confrontabilità unità stratigrafica episodio tettonico o climatico circa il punto b), riguardante la “confrontabilità” della durata della realizzazione di un’unità stratigrafica s.l. con quella di un “episodio” tettonico o climatico, è altresì facilmente verificabile che diverse unità di rango stratigrafico confrontabile possono corrispondere ad intervalli di tempo apprezzabilmente diversi. o meglio: episodi tettonici o climatici di rango diverso possono avere come riscontro unità stratigrafiche s.l. dello stesso rango. ad esempio un corpo alluvionale di modesto spessore può rappresentare il riscontro di un unico 1correlation: demonstration of the equivalence of two or more geologic phenomena in different areas; it may be lithologic or chronologic. also, the condition or fact of being correlated (dictionary of geological terms. american geological institute r. b. bates & j.a. jackson (ed.s), 3rd ed., 1983, anchor books.). 2correlation: parallelization, the determination, on paleontological or physical evidence, of the equivalence in geologic age and stratigraphic position of two formations or other stratigraphic units in separate areas. geological nomenclature. royal geological and mining society of the netherlands, a. a. g. schieferdecker ed., 1959, gornichem. 295considerazione sui criteri di correlazione ... sedimentarie e sinmorfogenetiche: esse possono dare le stesse manifestazioni su intervalli di tempo di durata molto diversa. ad esempio, nel caso di zone di taglio regionali come quelle che interessano la catena alpina nel settore occidentale, sul lungo termine possono verificarsi prolungati episodi deformativi, in grado di caratterizzare in modo alquanto omogeneo estese aree (es. susa-chisone shear zone; giardino & polino, 1997). sul breve termine, singoli episodi locali possono determinare l’attivazione di singoli segmenti di faglia (fig. 3; es. aosta-ranzola, carraro et alii, 1994). queste manifestazioni non hanno carattere eccezionale e locale come si riteneva in passato, ma fanno parte delle normale evoluzione geologica e interagiscono e si sovrappongono agli effetti delle variazioni climatiche. e’ questo il caso delle ripetute deformazioni sinsedimentarie registratesi a vari livelli della successione “villafranchiana” dell’areatipo (carraro, 1996; fig. 4). 4. diacronicità delle unità stratigrafiche ed episodi climatici e tettonici a completamento delle considerazioni sopra esposte e per analizzare i punti c) e d) dell’introduzione, occorre ricordare che in contesti geodinamici caratterizzati da mobilità tettonica (es. catena in sollevamento) fra i fattori che controllano il sistema sedimentario continentale, oltre al ruolo “dinamico” dei fattori esogeni ed endogeni va aggiunto quello “statico” fig. 1 tappe (da sinistra a destra) della costruzione di un’ipotetica successione stratigrafica costituita dalla composizione di “episodi” deposizionali ed erosionali. i numeri indicano i singoli “episodi” e la corrispondente “risposta” geologica (corpo sedimentario o superficie di erosione); t1, t2 … t7 gli intervalli di tempo. a, b e c superfici di erosione di rango da superiore a inferiore. nota: non c’è alcune relazione tra lo spessore dei corpi sedimentari ed i corrispondenti intervalli di tempo; la completa obliterazione dei corpi 3, 3a, 4 e 5 dovuta all’episodio erosionale 6, dimostra che, anche senza tener conto delle altre motivazioni indicate nel testo, non c’è diretta confrontabilità tra la successione stratigrafica conservata (1, 6 e 7) e la successione degli eventi (1…7); vedi fig. 2. chronological steps (from the left to the right) of the construction of an imaginary stratigraphic succession deriving from the composition of depositional and erosional episodes. numbers indicate the single episodes and their corresponding geological answer (sedimentary body or erosional surface); t1, t2,.... t7 the time spans. a, b and c: decreasing rank of erosional surfaces note: there is no relation between the thickness of the sedimentary bodies and the corresponding time spans; the complete obliteration of 3, 3a, 4 and 5 bodies due to erosional episode 6 demonstrates that, even without taking into account the others motivations mentioned in the text, there is no direct comparability between the stratigraphic succession preserved (1, 6 and 7) and the sequence of episodes (1.....7); see fig 2. fig. 2 possibile correlazione tra la successione stratigrafica finale di fig. 1 e la relativa successione di “episodi”. si noti la non esatta corrispondenza cronologica e la mancata rappresentazione di alcuni “episodi”. possible correlation between the final stratigraphic succession of fig. 1 and the related succession of episodes. note the not exact chronological correspondence and the lack of representation of some episodes evento estremo della durata di qualche ora oppure l’effetto cumulato di un episodio climatico di stabilità. ciò può dipendere in prima analisi dalle caratteristiche fisiche dei diversi ambienti di sedimentazione (es. fluviale, glaciale, lacustre, ecc.). anche la durata dei diversi “episodi” climatici che controllano la sedimentazione o l’erosione può essere molto diversa: si pensi alle variazioni a brevissimo, breve, medio e lungo periodo. gli studi sulla tettonica recente ed in atto stanno dimostrando che lo stesso vale per le deformazioni sin296 della diversa erodibilità delle formazioni rocciose via via esumate dall’erosione. quest’ultimo è responsabile della forte inerzia con cui il sistema risponde ai primi due gruppi di fattori (fig. 5). i tempi di reazione e di rilascio dei sistemi naturali successivi agli eventi che hanno introdotto la perturbazione possono essere molto diversi, così come i tempi di persistenza delle forme e dei depositi che li testimoniano. il geologo del quaternario si trova pertanto di fronte a sistemi naturali complessi nei quali i singoli fattori sono caratterizzati da velocità estremamente variabili (fig. 6): • le velocità con cui avvengono i cambiamenti climatici, • quelle con cui molto probabilmente avvengono anche le variazioni dell’attività geodinamica e, infine, • quelle con le quali si verifica l’esumazione di formazioni rocciose con diversa erodibilità. da ciò deriva la forte diacronicità (in genere purtroppo non verificabile) che può caratterizzare nel loro sviluppo complessivo la base ed il tetto di un’unità sedimentaria o una superficie di erosione in tutta la sua estensione. ad esempio la base dell’unità che rappresenta l’ultima massima espansione glaciale (lgm) in tutto lo sviluppo di una valle alpina ha una età molto diversa da valle verso monte. il divario cronologico tra l’età di una superficie nei vari punti della sua estensione può giungere fino ad essere di durata confrontabile con quella degli eventi climatici o tettonici che l’hanno determinata (un esempio in questo senso è fornito dal fatto che il numero di ordini di terrazzi che altro non sono che una successione di corpi sedimentari e di superfici di erosione presenti allo sbocco di una valle fluviale è diverso da quello presente in un’altra valle anche contigua). questa constatazione, del resto, non è altro che la trasposizione all’ambiente continentale e al quaternario di quanto riconosciuto per l’ambiente marino e per il pre-quaternario negli anni ’50, quando si è compreso che le unità sedimentarie che si riconoscono sul terreno sono unità litostratigrafiche e non hanno necessariamente una valenza cronologica. l’unica differenza, almeno apparente, sta nel fatto che le dimensioni degli episodi climatici o tettonici quaternari che si vogliono fig. 4 soft sediment deformations nei depositi “villafranchiani” (cava rdb, villafranca d’asti, asti). soft sediment deformations of the “villafranchian” deposits (rdb quarry, villafranca d’asti, asti). f. carraro & m. giardino fig. 3 deformazioni recenti del complesso fluviolacustre olocenico di st. vincent (cava zerbion, chatillon, aosta) (da carraro & alii, 1994). recent deformation of the st. vincent holocene fluviolacustrine complex (zerbion quarry, chatillon, aosta) (from carraro & alii, 1994). correlare con i vari termini della successione stratigrafica sono in assoluto minori di quelle degli episodi prequaternari, mentre il grado di diacronicità di una unità sedimentaria o di una superficie di erosione è indipendente dall’età. il grado di scansione che viene utilizzato nella cronologia del quaternario è però anch’esso molto più dettagliato per cui, se la diacronicità delle unità stratigrafiche è trascurabile nella stratigrafia del prequaternario non lo è invece in quella del quaternario. ne consegue la validità del punto d), cioè la non correlabilità corpo-episodio climatico o tettonico. 297 fig. 5 applicazione all’ambiente fluviale del concetto di “inerzia” nella risposta del sistema naturale alle sollecitazioni esterne (da bull, 1997). rt tempo di risposta = ra tempo di reazione + ra tempo di attenuazione. ps tempo di persistenza delle nuove condizioni di equilibrio. t ed e, condizioni di soglia e di equilibrio rispettivamente. application to the fluvial environment of the “inertia” concept in the response of the natural environment to the external stresses (from bull, 1997). rt , response time, is the sum of the reaction time, ra, and relaxation rime, ra. ps is the time of persistence of new equilibrium conditions, and t and e are threshold and equilibrium conditions, respectively. fig. 6 confronto fra velocità di diversi processi geologici esogeni ed endogeni (da summerfield 1991, modificato). comparison of rates of various endogenic and exogenic geomorphic precesses (from summerfield 1991, modified). considerazione sui criteri di correlazione ... 298 5. valore “assoluto” e buon grado di risoluzione degli elementi cronologici per quanto riguarda il reale significato delle datazioni numeriche (punto e), verranno prese in esame tre tipi di situazioni che posso rendere problematiche le correlazioni: • l’effettiva associazione dell’elemento che si data con l’“episodio” che si intende datare; • la possibile apertura del sistema chimico di riferimento per le datazioni geochimico-isotopiche; • il margine di errore nelle datazioni per effetto delle misure di laboratorio. il più importante è quello della effettiva associazione dell’elemento che si data con l’“episodio” che si intende datare. l’esempio che si cita di solito al riguardo è quello di un tronco fluitato ripreso da un deposito preesistente, la cui età non rispecchia quella del sedimento fluviale che lo contiene ma quella del deposito primario. ma accanto a questa si possono citare altre situazioni, ben più insidiose, nelle quali il divario di età può essere molto superiore. si prendano ad esempio i casi illustrati nelle figg. 7a e 7b. il disegno a esemplifica la situazione che può venirsi a creare, nel corso dell’evoluzione geologica superficiale (i singoli “episodi” della quale vengono indicati con una successione di numeri ordinali a partire dal substrato contrassegnato con 0) quando un suolo, sviluppatosi sul substrato nell’“episodio”, poniamo, n. 27 può essere ripreso da processi di colluvionamento durante l’“episodio”, poniamo, n. 104, ed i suoi prodotti colluviali, in molti casi assai difficilmente distinguibili dal suolo in posto, simulino l’età dell’elemento 27 per l’intercalazione 104. la stessa situazione può determinarsi nel caso di un deposito piroclastico depostosi sul substrato. tale circostanza è ancor più difficilmente riconoscibile nei casi (non infrequenti) in cui l’evoluzione geologica successiva ha portato ad un’inversione del rilievo (come rappresentato nella figura b) con la totale obliterazione dell’elemento 27. e’ da sottolineare che la verifica della effettiva associazione dell’elemento che si data con l’“episodio” che si intende datare non è di competenza del geocronologo ma dell’autore del prelievo, cioè del geologo di campagna. il secondo tipo di condizionamento è quello, che tutti hanno ben presente, dell’apertura del sistema chimico: ricordiamo a titolo di esempio la perdita di ar nelle datazioni k/ar oppure la presenza di th detritico che falsa i risultati delle datazioni degli speleotemi o di corallari con il metodo u/th. il terzo condizionamento è quello, inevitabile, del margine di errore delle misure di laboratorio. a questo proposito, in fig. 8 vengono richiamati i risultati di un test di affidabilità delle datazioni con il metodo del 14c, effettuato da alcuni tra i principali laboratori di geochimica isotopica del mondo. dai risultati di questo check, sponsorizzato dall'iaea, finalizzato alla valutazione dello stato dell'arte della misura della radioattività 14c e, di conseguenza, dei dati di cronologia radiometrica che da questa derivano, è emerso che gli errori (presupposto che il campione fosse ideale, totalmente rappresentativo dell’“episodio” che si voleva datare) sono derivati dalle seguenti operazioni previste per l'ottenimento del dato cronologico: fig. 7 situazione che può derivare dalla rielaborazione colluviale di un livello databile, in grado di falsare l’interpretazione stratigrafica. a e b rappresentano due differenti casi, nel secondo dei quali è intervenuto un fenomeno di inversione del rilievo. situation eventually derived from the colluvial reworking of a datable layer, able to alter the stratigraphic interpretation. a and b are two different cases, the second one being the effect of a relief inversion. f. carraro & m. giardino a) procedimenti chimici preliminari (tipo, modalità, grado di completezza degli stessi); b) processo di conversione del campione nel composto chimico scelto per eseguire la misura della radioattività 14c; c) misura della radioattività 14c. il test al quale si riferiscono i risultati prevedeva una valutazione complessiva, quindi le incertezze relative ai punti a), b) e c). inoltre, poiché nelle misure sperimentali ha anche importanza la riproducibilità (un dato campione deve fornire la stessa età se rimisurato più volte), il campione oggetto dei due check era unico ed è risultato avere circa 5.000 anni b.p. questo è stato fornito a circa 70 laboratori nel mondo, inclusi quelli più prestigiosi; di questi solo una trentina eseguirono e quindi trasmisero i risultati delle misure. osservando i risultati, si nota che il numero dei laboratori accomunati dalla stessa dispersione nelle due prove è variabile. l’unico dato con una dispersione di –500 anni è imputabile a un errore, mentre gli altri possono considerarsi “fisiologici”. 299 fig. 8 rappresentazione grafica dei risultati di un test di affidabilità sulle datazioni al radiocarbonio (dati iaea). la dispersione tra -6 e +6% nei risultati delle datazioni di laboratorio è da considerarsi “fisiologica”. il valore di -10% è imputabile ad errore. graphical representation of a reliability test of radiocarbon datings (iaea data). the data dispersion between –6 and +6 has to be considered “physiological”. the –10% value is due to an error. fig. 9 eta' geologica" di un'unita' litoo allostratigrafica. sulla base dei dati disponibili l'età dell'unità risulta compresa tra 470.000 e 150.000 anni b.p., quindi tra la parte media e la parte superiore del pleistocene medio. in base ai dati reali (non noti) l'età è invece compresa tra 650.000 e 112.000 anni b.p. e quindi si estende tra la parte inferiore del pleistocene medio ed il pleistocene superiore. geological age of a lithoor allostratigraphic unit. based on available data, the unit age fits into an age interval between 470.000 and 150.000 years b.p.. (middle middle pleistiocene – upper middle pleistocene). in fact, based on real data (unknown), the unit age fits between 650.000 ande 112.000 years b.p. (lower middle pleistocene – upper pleistocene). considerazione sui criteri di correlazione ... 6. l’età di un’ “unità stratigrafica l. s.”. considerazioni conclusive nei casi fortunati in cui si disponga di elementi di datazione, va però tenuto presente il possibile forte divario esistente tra l’intervallo di tempo definito dagli elementi di datazione disponibili e l’età effettiva dell’unità stratigrafica. naturalmente il divario tra età indicata dagli elementi disponibili e l’età reale esiste anche nelle datazioni del pre-quaternario ma in questi casi è in genere trascurabile dato il basso grado di scansione cronologica utilizzato. da tutto quanto esposto ci sembra risulti sufficientemente documentato che correlazioni basate su un basso numero di datazioni sono molto deboli e discutibili. nel tentare delle correlazioni appare perciò opportuno spingersi, solo in presenza di un numero significativo di elementi di datazione, unicamente al livello o ai livelli che contengono gli elementi stessi e non all’intera unità sedimentaria, meno che meno alla successione in cui questa è compresa. qualsiasi altro tentativo resterà tale e come tale è opportuno sia presentato in eventuali lavori di sintesi. lavoro pubblicato nell’ambito del progetto di ricerca cofin-miur 2002 “frane e clima”, coordinatore nazionale prof. m. soldati 7. lavori citati bull w. b. (1991) geomorphic responses to climatic change. 326 pp. oxford univ. press, new york. carraro f. (ed.) (1996) revisione del villafranchiano nell'area-tipo di villafranca d'asti. il quaternario, vol. 9, fasc. 1, 5-120, 66 ff., 2 tt. (1 carta geol. 1:20.000). carraro f., ghibaudo g., giardino m. & perotto a. (1994) intense deformazioni in depositi fluviolacustri olocenici nella media valle d'aosta. atti ticinesi sc. terra, ser. spec., vol. 1, pp. 123-136, 6 ff, 1994. carraro f. & lucchesi s. (in stampa) application of integrated allostratigraphy in the geological survey of the central piedmontese plain. in: pasquarè g. & venturini c.: geological mapping in italy, selca, firenze. giardino m. & polino r. (1997) le deformazioni di versante dell’alta valle di susa in relazione con l’evoluzione tettonica recente. dati preliminari. il quaternario, 10 (2): 31-38. summerfield m. a. (1991) global geomorphology: an introduction to the study of landforms. 537 pp. longman scientific and technical, essex. 300 ms. ricevuto il 20 luglio 2004 testo definitivo ricevuto il 30 novembre 2004 ms. received: july 20, 2004 final text received: november 30, 2004 f. carraro & m. giardino travertine versus calcareous tufa: distinctive petrologic features and stable isotopes signatures anna gandin & enrico capezzuoli dip. scienze della terra, università di siena, via laterina 8, 53100 siena e.mail: gandin@unisi.it abstract: a. gandin & e. capezzuoli, travertine versus calcareous tufa: distinctive petrologic features and stable isotopes signatures. (it issn 0394-3356, 2007). terrestrial limestones, mainly deposited as calcite crusts by carbonate-rich waters flowing in subaerial settings, originate from warmto-hot waters of hydrothermal provenance (travertines) or from cool waters of karstic derivation (calcareous tufa). the two groups of concretionary carbonates are actively forming in different geomorphologic settings such as cool-water springs and fluvial valleys, or in the surroundings of the emergence of thermal springs. fossil remains of these rocks are frequently found in calcareous areas as well as in areas where carbonate rocks are not exposed. however the recognition on the field of their genetic derivation when connections with the feeding source are no more evident, is often uncertain since the definition of the specific litofacies are not yet completely elucidated. the detailed analysis of the lithofacies of calcareous tufa and travertines as well as the critical elaboration of existing geochemical data, shows that the petrologic features and stable isotopic signatures reflect the contrasting environmental conditions of deposition deriving from physico-chemical properties of the feeding waters that, although mostly of meteoric provenance, experienced different circulation/recharge history. travertines are well bedded, often finely laminated compact limestones, composed in the proximal part of the thermal system by peculiar crystalline crusts and in the distal part by bacterial/cyanobacterial laminites often associated with thin crystalline crusts, lenses of calcified-bubbles and paper-thin rafts. in this system the carbonate deposition mainly derives from intense outgassing of the emerging supersaturated waters, and evaporation, concomitant with the rapid drop in temperature along the drainage network. travertine mineral content originates in deep geothermal/hydrothermal conditions where hot waters charged with hco3 of meteoric and hypogean derivation, are able to dissolve high quantities of carbonate and/or evaporitic bedrock. the circulation of hot waters, allowed by open fractures/faults is ultimately controlled by extensional tectonics. calcareous tufa are poorly bedded, porous/chalky deposits containing frequent remains of macrophytes and invertebrates. they are made up of dominantly microcrystalline calcite of abiotic and biotic precipitation, forming phytohermal, stromatolitic or phytoclastic facies. it is commonly found in fluvial/palustrine depositional systems fed by carbonate-rich waters mostly deriving from karstic springs. the carbonate deposition deriving from mainly mechanical (vaporization/evaporation) and less significant biologic removal of co2 from flowing or standing waters, results to be controlled by the availability of meteoric water and ultimately by local and/or global climatic conditions. the comparison of petrofacies and the critical elaboration of the related stable isotopic signatures of deposits still connected with the parent water and source systems, provide criteria for the univocal lithologic identification of their fossil counterparts so that the mainly climate-controlled calcareous tufa and the mainly tectonics-controlled travertines can be easily detected even on the field. riassunto: a. gandin & e. capezzuoli, travertini e calcareous tufa: caratteristiche petrologiche e isotopiche. (it issn 0394-3356, 2007). tra i carbonati continentali sono compresi i sedimenti prevalentemente formati da croste calcaree derivati da acque dolci scorrenti ricche in carbonato di calcio. in base alle caratteristiche fisiche di queste acque, è possibile distinguere i depositi originati da acque “calde” di provenienza idrotermale (travertini) da quelli precipitati da acque “fredde” di derivazione carsica (calcareous tufa). questi due gruppi di calcari concrezionari sono caratteristici di sistemi deposizionali e geomorfologici molto differenti: sorgenti termali i primi, ambienti fluvio-palustri i secondi. affioramenti fossili di questi depositi si trovano comunemente, ma il riconoscimento sul terreno della loro derivazione genetica è spesso incerta a causa dell'assenza di una precisa definizione specifica delle relative litofacies. l'analisi dettagliata delle litofacies dei travertini e dei calcareous tufa e la contemporanea elaborazione critica dei dati geochimici ricavati dalla letteratura mostra che le loro caratteristiche petrologiche e isotopiche riflettono le caratteristiche fisico-chimiche delle acque di origine le quali, anche se hanno la stessa derivazione meteorica, testimoniano di una differente ricarica e circolazione idrogeologica. i travertini sono carbonati compatti, ben stratificati e in genere fittamente laminati. essi si originano esclusivamente nelle vicinanze di sistemi idrotermali. nella zone prossimali la fuoriuscita e lo scorrimento di acque calde sovrassature in carbonato di calcio determina la formazione di peculiari croste cristalline, mentre nelle porzioni più distali divengono predominanti le lamine batteriali/cianobatteriali spesso associate con sottili lamine cristalline, lenti di bolle gassose incrostate e impronte di vegetali. gli alti tassi di accrescimento dei travertini sono condizionati dal veloce degassamento delle acque supersature e dall'evaporazione. il contenuto minerale delle acque riflette la natura delle condizioni idrotermali/geotermali nelle quali acquisiscono calore durante il loro percorso profondo. la temperatura di queste acque, ricche di hco3 di derivazione meteorica o anche magmatica, infatti, permette la dissoluzione di grandi quantità di carbonati o solfati contenuti nelle rocce del substrato. la loro circolazione, intimamente connessa alla presenza di faglie/fratture beanti, è strettamente controllata dalla tettonica principalmente di tipo estensionale. i calcareous tufa sono depositi generalmente porosi e scarsamente stratificati, contenenti abbondanti tracce di macrofite e invertebrati. essi sono composti principalmente da calcite microcristallina di precipitazione abiotica e biotica che forma facies fitoermali, stromatolitica o fitoclastica caratteristiche di ambienti deposizionali fluvio-palustri con acque carbonatate derivanti da sistemi carsici. la deposizione, in genere lenta e con bassi tassi di accrescimento, è principalmente controllata dalla rimozione meccanica (vaporizzazione/evaporazione) e biologica (fotosintetica) della co2 da acque scorrenti o stagnanti. tale processo risulta ovviamente condizionato dalla disponibilità di acqua meteorica e, di conseguenza, dalle condizioni climatiche. il confronto delle diverse petrofacies e l'elaborazione critica dei relativi contenuti isotopici derivati da depositi ancora connessi con le loro acque madri, fornisce un criterio per un'univoca identificazione litologica dei depositi fossili. in tal modo i calcareous tufa ed i travertini possono essere facilmente riconosciuti anche sul terreno, allo scopo di discernere quelle strette relazioni con il clima (calcareous tufa) e con la tettonica (travertini) che li caratterizza e che li ha posti al centro della ricerca internazionale nell'ultimo decennio. key words: travertine, calcareous tufa, sedimentology, petrology, stable isotopes. parole chiave: travertini, calcareous tufa, sedimentologia, petrografia, isotopi stabili. il quaternario italian journal of quaternary sciences 21(1b), 2008 125-136 126 a. gandin & e. capezzuoli 1. introduction continental carbonates are vulnerable rocks that in the geologic record rarely survive erosion and dissolution but are extensively recorded in the quaternary continental successions of areas where the exposed and/or buried carbonate bedrock acts as calcium reservoir for the circulating groundwaters. however terrestrial limestones are presently forming on the earth surface, in different geomorphologic/geodynamic settings under a wide range of conditions and are controlled by contrasting physico-chemical properties of the waters. remnants of their fossil counterparts are frequently found in calcareous areas as well as in areas where carbonate rocks are not exposed, and disconnected from their primary setting. consequently their origin and paleoenvironmental meaning can be difficult to assess since most of the published data do not account for the lithologic and petrographic features of the different types of terrestrial carbonates. continental limestones deposited as primary calcite crusts by flowing carbonate-rich waters are also known as flowstones. lacustrine alike marine pelagic carbonates, settles in standing body of water below the high-energy zone (wave base). they are mostly represented by lime-mudstone composed of microcrystalline calcite (micrite). flowstones include speleothems, deposited in the subsurface environment of the karst system, and spring related carbonates deposited in open-air conditions but in different geomorphologic settings and contrasting physico-chemical properties of the waters. groundwaters mostly of meteoric origin acquire, during more or less deep geothermal circulation pathway, different temperatures and saline concentrations rising at the spring as supersaturared/saturated carbonate waters, warmer (thermal) or cooler (karstic) than the ambient temperature. in the current nomenclature the appellation of thermogene and meteogene travertines proposed by pentecost & viles (1994) that however does not take in account the genetic sedimentary and environmental processes, is sometimes still used (mi n i s s a l e et al. , 2002; pentecost, 1995; 2005 and reference herein). the more realistic terminology of travertines, calcareous tufa and speleothems, proposed by ri d i n g (1991) and ford & pedley (1996), is based on the litho-genetic features of terrestrial flowstone carbonates and takes also in account the historical term of travertine. travertine is the long time appellation of a compact laminated calcareous lithology quarried since etruscan times in etruria (present-day tuscany and northern latium; ga n d i n et al., 2006) and in roman times near the town of tibur (present name is tivoli) where it is formed ("lapis tiburtinus") by hot waters rising from tectonically controlled presently active hydrothermal springs (faccenna et al., 1994), still called acquae albulae (latin for "whitish waters"). thus the tivoli area must be considered the geological typelocality of the thermal-related terrestrial limestone, the travertine. calcareous tufa is the recent denomination of highly porous massive limestone deposited from cool or ambient temperature waters of karstic and/or meteoric derivation, in climate controlled alluvial/palustrine systems (pedley, 1990; ford & pedley, 1996). speleothems, mainly stalactites, stalagmites and flowstones, are finely laminated macrocrystalline hypogean deposits bui lt by successive rows of acicular/radiaxial, often ferroan calcite (fr i s i a, 2003). it slowly precipitates from water drops in the dark subsurface, vadose conditions of the cave systems. in many of the thermal or cool water spring-related subaerial sites where active deposition occur, older, often terraced deposits, even if affected by post-depositional processes (diagenetic cementation and/or karstic epigenetic dissolution and erosion), attest to the continuity of the sedimentation and show evidence of the different depositional pattern of the respective carbonate bodies. however since the meaning of the specific petrologic features of these sediments are not well known, they are often mixed up under the all-comprising term of travertine (julià, 1983; turi, 1986; cilla et a l. 1994; ch a f e t z & la w r e n c e, 1994; pe n t e c o s t, 2005; du b a r, 2006 and references therein), disregarding detailed lithologic descriptions already published (ford & pe d l e y, 1996; gu o & ri d i n g, 1998; 1999) and the potential information that their dissimilar depositional settings imply (capezzuoli & gandin, 2004). the purpose of this article is to investigate on the relationships between the specific petrologic features and fabrics of "living" travertines and calcareous tufa and their distinctive physico-chemical properties and isotopic signature. the results of the critical elaboration of new and existing data will provide petrologic criteria supported by isotopic data, for the genetic, climatic or tectonic/geologic identification of “old” terrestrial carbonate deposits no more connected with their primary source systems. 2. depositional and isotopic characteristics of travertines and calcareous tufa subaerial flowstones originate in depositional systems characterized by contrasting environmental and physico-chemical properties and different sources of the mineral content of the waters. the specific petrologic features of spring-related calcareous deposits and the rate of crystal growth, results from the physico-chemical characteristics of precipitation processes that ultimately are controlled by the conditions of the flowing fluids, such as velocity of the flux, outgassing, ionic concentration and temperature. temperature of spring and stream waters in turn, is controlled by the temperature the groundwater reaches in the hypogean circulation. source of the ca-bicarbonate-rich waters are shallow (karstic) or deep (geothermal) subsurface circulation networks where waters charged of dissolved co2 of soil and/or meteoric derivation interact with the carbonate/evaporitic and/or magmatic bedrock and outflow from hydrothermal or karstic springs, as warm/hot or cool waters. the hco3 and ca+ 2 ions dissolved in more or less concentrated solutions are of mixed provenance mostly meteoric, partially recycled (dissolution of bedrock carbonates and/or evaporites) locally magmatic. the hydrothermal system develops in areas where deep tensional fractures (hancock et al., 1999; shipton et al., 2004; altunel, 2005; brogi & capezzuoli, 2008) or volcanic intrusions promote the hypogean circulation and heating of waters of meteoric and/or juvenile derivation. the mineral content of the outflowing thermal waters (min 20°c up to 90°c, pentecost, 2005) originates from the dissolution of high quantities of carbonate and/or evaporitic bedrock that often is not exposed on 127travertine versus calcareous tufa ... the surface. the subaerial circulation of the warm, sulphur/sulphate-rich thermal waters appears to be adverse to the vegetation, giving rise to an arid/desert white landscape (capezzuoli & gandin, 2005) (fig. 1a). fig. 1 -examples of the thermal, "white desert" environment and related travertine deposits: a) shallow pools barred by crystalline rimstones along a low-gradient slope (pamukkale, turkey); b) the steep slope of a dried waterfall covered by micro terraces and larger/deeper bowl-like basins (terme san giovanni, rapolano terme, italy); c) well bedded, laminated body of travertine showing a low-angle unconformity and dark intervals (black arrows) corresponding to lacustrine/pedogenetic episodes (serre di rapolano, italy); d) transversal flexure-like section of a dam rimstone composed of regularly laminated crusts of crystal fans (bagno vignoni, italy). microfabrics of crystalline crust travertine: e) crystal fans made of finely laminated cloudy fibrous calcite (rapolano terme, italy); f) feather-like bacterial/crystal shrubs partially growing on encrusted gas bubbles (rapolano terme, italy). esempio di ambiente termale desertico "il deserto bianco ", e dei relativi depositi travertinosi; a) pendio poco acclive con vasche disposte a terrazzo delimitate da bordi cristallini (pamukkale, turchia); b) porzione acclive di una cascata inattiva coperta da microe macroterrazzi a forma di scodella (terme san giovanni, rapolano, italia); c) corpi di travertino laminato e ben stratificato. sono evidenti una discordanza a basso angolo e intervalli scuri (frecce nere) corrispondenti a episodi lacustri e/o pedogenetici (serre di rapolano, italia); d) sezione trasversale del bordo di una vasca formato da croste incurvate di calcite cristallina a ventaglio ben stratificata (bagno vignoni, italia). microfabric delle croste cristalline di travertino: e) ventagli di calcite aciculare finemente laminata con concentrazioni di impurezze (rapolano terme, italia); f) cespugli batteriali/cristallini a forma di piuma in parte accresciuti su bolle di gas incrostate (rapolano terme, italia). the karstic system, a shallow subsurface vadose network, developed in areas where carbonate rocks are exposed and the supply of meteoric water is rather abundant, yields mineralised waters which outflow at the spring with temperatures commonly cooler than the surrounding ambient but more or less stable throughout the year within the cave system (ho r v a t i n c i c et al., 2003). the ca-rich waters giving rise to carbonate deposits, at the same time promote the establishment of a well developed riverine/palustrine depositional system and the growth of luxuriant vegetation (fig. 2a, b). notwithstanding the extremely different physico128 fig. 2 examples of well vegetated fluvial/palustrine environment and related calcareous tufa deposits: a) diborrato, dam and pool system (colle val d'elsa, italy); b) yenice, cascade system (meander river valley, turkey); c) massive, phytohermal tufa composed of staked cushion-like elements (diborrato, colle val d'elsa, italy); d) transversal flexure-like section of a dam rimstone composed of irregularly superposed biostromal layers (diborrato, colle val d'elsa, italy). microfabrics of calcareous tufa: e) organic remains (white arrows) alternated with rows of limpid crystalline calcite (“stromatolitic” facies; colle val d'elsa, italy); f) rivularia filaments enclosed in limpid sparite (phytohermal facies, la pigna falls, monticiano, italy). esempi di ambienti fluviali/palustri ben vegetati e dei relativi depositi di calcareous tufa: a) sistema di vasche e bordi rialzati (rimstones) presso il diborrato (colle val d'elsa, italia); b) sistema di cascata presso yenice (fiume meandro, turchia); c) calcareous tufa fitoermali mal stratificati composti da elementi a cuscino sovrapposti (diborrato, colle val d'elsa, italia); d) sezione trasversale del bordo di una vasca formato da croste biostromali incurvate e irregolarmente sovrapposte (diborrato, colle val d'elsa, italia). microfabric di calcareous tufa: e) alternanza di livelli scuri con residui organici (frecce bianche) e di livelli di calcite cristallina limpida (facies “stromatolitica”, colle val d'elsa, italia); f) filamenti di rivularia inclusi in cristalli di calcite spatica (facies fitoermale, cascata de la pigna, monticiano, italia). a. gandin & e. capezzuoli chemical properties of the waters of the two spring systems, some of the physical processes connected with the precipitation of calcium carbonate give rise to similar depositional structures in the carbonate bodies that however are characterized by completely different fabrics and biologic involvement (fig. 1, 2). precipitation of calcium carbonate mainly derives from the removal of co2 from carbonate-rich waters and its amount is consistent with the concentration and temperature of the parent water. abiotic/physical precipitation is dominant under turbulent flow regime whereas evaporation and effective biomediation/photosynthetic action requires sluggish flow or static water (pedley, 1990). vaporization and outgassing, largely dominant processes connected with falls, rapids and the presence of obstructions on the stream paths, contribute to the passive encrustation of every object vegetal, animal or rock the flow runs into. the rapid removal of co2 acting during the water drift or within static waters of intervening basins, moreover, induces the precipitation of solid encrusting calcite in a succession of arcuate rims/barrages/terraces (r imstones) that delimit pools/ponds of variable sizes and depths (fig. 1a,b; fig. 2a,b), depending on the amount of flowing water and the gradient of the drainage path (ha m m e r et al, 2007; pedley et al., 1996; pentecost, 2005). evaporation is also a physical process induced by higher temperatures of the water at the air/water interface of shallow small or large basins. consequent, occasional whitenings result in abiotic microcrystalline calcite that, together with possible biotic micrite produced by the photosynthetic activity of aquatic organisms, settle as lime mud on the bacterial biofilms supports made of extracellular polymeric substances (eps) at the bottom of the basin. growing evidence indicates that active biologic/photosynthetic contribution to the carbonate precipitation results to be effective even if actually negligible, mostly in the fluvial/palustrine system where dominant macrophytes prosper because of the cool and humid conditions of the environment (merzpreiss & riding, 1999). in the hot waters of thermal springs and in their arid surroundings, conditions of life are extreme and the organisms involved, mostly heat-loving bacteria, play a passive role of support to the precipitating calcite. bacterial colonies are commonly found in both systems; they settle in lower-energy microhabitats/ niches sheltered from the tractive flow on the bottom of the basins, or on the sides of channels, and passively incorporate carbonate particles in the mucilaginous biofilm (eps) they produce (merz-preiss & riding, 1999). the sediment that settles within the floodbasins is in part carbonate sand transported by the flow but most of it has specific features that reflect the original concentration of the water and the difference between water and ambient temperatures. in the assumption that the δ13c and δ18o values of subaerial flowstones must reflect the different physicochemical properties of the parent waters, a survey has been carried out of the published stable isotope data on recent deposits of well known origin collected in the most significant present day sites of formation (fig. 3, 4) with the intent to find the possible relationships between the overall depositional conditions of each spring system and the resulting sedimentary and petrologic features. the geochemical ratio of the stable isotope pairs of carbon and oxygen (1 2c, 1 3c and 1 6o, 1 8o) depends mostly on the physico-chemical conditions of water (temperature and saline/co2 concentration) that promote isotopic fractionation. ratios compared to a standard sample (pdb = a cretaceous belemnite; smow = standard mean ocean water, only for oxygen) are expressed in the δ pdb or smow (‰) notation providing an expanded scale for the comparatively small differences observed. fractionation, resulting from the loss for evaporation, degassing or metabolic consumption of the lighter isotopes during the (bio)geochemical cycle, induces discrete changes of c and o ratios. their values therefore provide information about the physico-chemical conditions of the precipitation events (rate and temperature) and the influence of potential metabolic processes, hence about the sources of water and carbon dioxide as well. it also provides information on the temperature at which deposition occurred and assists in radiometric dating (more references in: fouke et al., 2000; andrews, 2005; pentecost, 2005). 3. travertine present day hydrothermal systems where travertine is forming (the san giovanni terme spring system at rapolano near siena fig. 1b,c,d is an excellent example; ba r a z z u o l i et al., 1988), are fed by warm to hot carbonate-rich waters, often charged with other ionic compounds such as sulphate/sulphide, chlorine, etc., surfacing from linear or punctiform vents. the mineral content of the hot waters originates in deep geothermal/hydrothermal conditions where heated waters charged with hco3 of meteoric and hypogean/magmatic derivation, are able to dissolve high quantities of carbonate and/or evaporitic bedrock. their circulation, allowed by open fractures/faults, is ultimately controlled by extensional tectonics (si b s o n, 2000; hancock et al., 1999; brogi et al., 2005; brogi & capezzuoli, 2008). in this system carbonate deposition, marked by a high-rate production, mainly derives from intense outgassing of co2 and evaporation of the emerging waters which concurs to the rapid drop in temperature of the supersaturated waters flowing along the drainage network. the biological contribution in the thermal spring environment is not relevant since the subaerial circulation of warm/hot, unhealthy carbonate-saline waters prevents the development of macrophytes. only heatloving bacteria develop on humid surfaces or warm water puddles and pools (ch a f e t z & fo l k, 1984). moreover, precipitation of calcite is so rapid that even bacteria and cyanobacteria have no time/possibility to colonize the carbonate surface that remains a bare white desert landscape (fig. 1). in the desert thermal landscape the rapid removal of co2 results from the simultaneous processes of outgassing, vaporizing/cooling combined with the surface flow characteristics that in turn are controlled by the morphologic gradient of pre-existing or self-built slopes 129travertine versus calcareous tufa ... (fig. 1a,b). velocity and turbulence of the flow control the shape and distribution of the sedimentary bodies. smooth flows running on flat to inclined surfaces, where obstructions are rare and commonly of small size (fig. 1a), gives rise to plane, regularly laminated beds, locally showing a large scale lenticular trend (fig. 1c). the resulting carbonate edifices vary in shape from suspended channels to cones and ridges made up of coalescing smaller cones or vents. conversely turbulent flows give rise to waterfalls and rimstones (fig. 1b) of any size (large rimmed terraces to microterraces) made of calcite beds arranged in a succession of structural flexures (fig. 1d) producing arcuate barrages that delimit shallow floodbasins (fig. 1a,b). the sedimentary architecture resulting from this depositional system defines the carbonate lithotype designated as travertine. it is characterized by well bedded, finely laminated limestones, composed in the proximal part of the thermal system by peculiar macrocrystalline crusts and in the distal part by bacterial/cyanobacterial microcrystalline/mud-supported sediment (guo & riding, 1998; 1999; özkul et al., 2002). the specific petrologic features are represented by regularly laminated, commonly flat bodies built up by a compact, laminated crystalline fabric composed of feather-like crystals (fig. 1f) or crystal bushes grown from smooth flows along low gradient drainage channels or of crystal fans (fig. 1e) deriving from turbulent flood in waterfalls. interbedded lenticular bodies of microcrystalline, granular or mud supported deposits correspond to the backfill of ponds and puddles that varies in texture and content depending on their distance from the vent, hence on the temperature and concentration of the water. on the standing waters of proximal basins, whitenings related to evaporation hence rapid removal of co2, induce the precipitation of microcrystalline calcite on bacterial biofilm supports (eps) at the bottom of the basin, giving rise to a characteristic spongy fabric (see fig. 4c in gandin et al., 2006). brittle crystalline crusts often form on the hot water surface floating pack-like until, under the increasing load of calcite and cyanobacterial growth, sink at the bottom in stacks of slabs, giving rise to the paperthin raft fabric described by gu o & ri d i n g (1998). in secluded parts of channels the combined actions of bacterial/biological activity outgassing and evaporation induce the formation of peculiar foam-like structures made of gas bubbles coated by a microcrystalline calcite film and sometimes encrusted also by feather-like crystals (fig. 1f). in the more distal basins the lime mud-fill contains remains of ostracods, gastropods, c h a r a and diatoms attesting the presence of life and consequently of cooler less mineralised waters. associated with the lacustr ine-l ike facies, more or less developed pedogenetic/root concretions, document episodic desiccation and pedogenetic processes deriving from the interruption and/or diversion of the water flux. geochemical analyses of presently forming travertines have been performed on samples collected from several thermal localities as the yellowstone park hydrothermal springs systems (fr i e d m a n, 1970; fo u k e et al., 2000); in italy le zitelle springs near viterbo and bagni san filippo on the monte amiata (siena), related to volcanic complexes (gonfiantini et al., 1968; chafetz & la w r e n c e, 1994) and the rapolano/acqua borra (siena) geothermal springs (guo et al., 1996); in spain near granada (jimenez de ci s n e r o s et al., 2006). the temperature of the parent groundwaters at the emergence of the studied thermal springs (fig. 3) vary from 34°c (spain) up to 60°c (le zitelle) and 73°c (yellowstone). stable isotopic data obtained from calcite precipitated from hot/warm waters in these localities, have been plotted on a cartesian coordinate system where it is possible to observe that the δ1 3c versus δ1 8o pdb values falls in the same field of distribution characterized by dominantly positive δ13c values (fig. 3). the δ18o (pdb) range from -4‰ to -30‰, appears to be influenced by high temperatures and supersaturation levels of the outflowing waters (fr i e d m a n, 1970; gu o et al., 1996; fo u k e et al., 2000). the increase of δ18o values indicates evaporation of the lighter isotope 1 6o and cooling of the waters, whereas heavier values of δ1 3c reflect removal of the lighter isotope 1 2c, and consequent outgassing of co2 (gonfiantini et al., 1968; usdowski et al., 1979; turi ,1986; chafetz & lawrence, 1994). the typical range from -2‰ to +8‰, of δ1 3c values in travertines, is interpreted to reflect the contamination of the isotopic composition of groundwater by the bedrock marine limestones or juvenile/magmatic waters (go n f i a n t i n i et al., 1968; fr i e d m a n, 1970; tu r i, 1986; guo et al., 1996). it is worth noting that soil derived carbon has never been reported from thermal groundwater composition (pentecost, 2005). the contribute of recycled isotopes is also supported by the proximity of the distribution field of the isotopic values of travertines and recent marine carbonate sediments and older limestones (fig: 5), which records similar evaporative conditions of calcium carbonate precipitation in warm marine waters and also the recycling through dissolution, of the heavier fossil 13c isotope. this specific distribution of stable isotopic values of travertine, while attesting the thermal imprint of the carbonate parent fluids, register dominantly physico-chemical precipitation of carbonates and a relevant contribution of ions deriving from carbonate bedrock and/or juvenile/magmatic waters. 4. calcareous tufa present day riverine/palustrine systems where calcareous tufa are actively forming (the diborrato water system fig. 2a, c, d in colle val d'elsa area, near siena is an instructive example), are fed by carbonate-rich waters of meteoric derivation mostly rising from karstic springs, or in some cases resulting at least in part, from diluted and cooled, originally thermal waters (capezzuoli et al., 2008). the mean temperature of groundwaters at the emergence of karstic springs is on average, cooler (2°c lower in the dinaric karst; horvatincic et al., 2003) than the flowing waters from which tufa precipitates. however it rapidly equilibrates with the local atmospheric temperature that is influenced by seasonal changes and controlled by the latitudinal position and global climatic regime. the subaerial circulation of cool/ambient temperature waters, promote the development of vegetation and subsequent precipita130 a. gandin & e. capezzuoli 131 fig. 3 combined plot of δ18o (smow/pdb) and δ13c (pdb) values derived from travertine sampled in selected active thermal localities of the world. data sources: yellowstone (angel terrace fouke et al., 2000; main spring friedman, 1970); bagni san filippo (siena, italy) (gonfiantini et al., 1968); le zitelle (viterbo, italy) (chafetz & lawrence, 1994); terme san giovanni (siena, italy) (guo et al., 1996); acqua borra (siena, italy)(unpublished data); alicun de la torres (spain) (jimenez de cisneros et al., 2006). diagramma combinato dei valori di δ18o (smow/pdb) e δ13c (pdb) di travertini campionati in alcune località termali attive nel mondo. dati ricavati da: yellowstone (angel terrace fouke et al., 2000; main spring friedman, 1970); bagni san filippo (siena italia) (gonfiantini et al., 1968); le zitelle (viterbo, italia) (chafetz & la w r e n c e, 1994); terme san giovanni (siena, italia) (gu o et al., 1996); acqua borra (siena, italia) (dati originali); alicun de la torres (spain) (jimenez de cisneros et al., 2006). tion of calcium carbonate that however show a low-rate production. the removal of co2 from flowing or standing waters is controlled by the dominant action of physical processes as vaporization/evaporation combined with a minor contribution from the biologic/photosynthetic activity of the emerged vegetation. in places where the energy of the waters is higher, the tumultuous and more copious release of co2 stimulates the development of luxuriant vegetation. emergent as well as aquatic plants and reeds, colonies of microbes, mosses and algae settle preferentially on raised irregularities of the stream bottom and on dam/barrages rims. vaporization/outgassing processes enhanced by the irregularly scattered vegetal clusters and thickets acting as obstacles to the current flux (fig. 2a,b), lead to the gradual, more or less pervasive calcification of massive pillow-like phytohermal/stromatolitic edifices (fig. 2a, b, c). filaments, stems and rows of green organic matter progressively encrusted by microcrystalline or larger crystals of limpid prismatic calcite can be detected within “ancient” as well as in “living” (fig. 2e,f) phytohermal deposits. in the backward floodbasins delimited by phytohermal barrages, rather quiet palustrine/lacustrine-like conditions of sedimentation occur. chara meadows and concentrations of diatoms sometimes develop on the bottom floored by lime mud with a characteristic peloidal fabric. the typical porous/chalky fabric consists of microcrystalline, low-mg calcite and peloidal aggregates of abiotic and biotic production. abundant vegetal remains are preserved mainly as casts of fragments and parts of macrophytes or as filaments encased within limpid calcite spar (fig. 2e, f). remains of invertebrates are frequently found. many of the vegetation components are organisms such as diatoms and characeans that favour cool fresh-waters and mosses/bryophytes that cannot tolerate temperatures higher than 20°c (gl i m e & vi t t, 1984). therefore the biologic contribution in the precipitation of carbonates in the riverine/palustrine system where macrophytes prosper, results to be mainly a passive role of support controlled by the availability of meteoric water. the sedimentary architecture resulting from this travertine versus calcareous tufa ... depositional system defines the carbonate lithotype designated as calcareous tufa. it consists of highly porous, poorly bedded, irregularly staked lenticular bodies of massive phytohermal or stromatolitic buildups (fig. 2c) associated with thin lenticular layers of unsorted phytoclastic sands and/or mud-supported pond-related sediments (bu c c i n o et al., 1978; d'ar g enio et al., 1983; ferreri 1985; brancaccio et al., 1986; d'argenio & ferreri, 1988; violante et al., 1994; 1996). the environmental requirements for the deposition of calcareous tufa are ultimately regulated by climatic local or global conditions (ho r v a t i n c i c et al. , 2003). geochemical analyses of presently forming calcareous tufa have been performed on samples collected from several riverine/stream systems in central-northern europe. the parent water temperatures of the studied carbonate samples (fig. 4), range from average 10°c in northern/central europe up to 20°c in the mediterranean area (9°c in poland and uk, thorpe et al., 1980; pazdur et al., 1988; andrews et al., 1994; garnett et al., 2004; 10°c in germany and belgium, an d r e w s et al. , 1994; janssen & swennen, 1997; 15°c in spain, sancho et al., 1997; andrews et al., 2000; arenas et al., 2000; peña et al., 2000). stable isotopic data obtained from the calcite precipitated from cool spring/stream waters in these localities, have been plotted on a cartesian coordinate system where it is possible to observe that the δ13c versus δ18o pdb values all falls in the same field of distribution characterized by negative δ13c values (fig. 4). the typical range of δ1 3c values in calcareous tufa, from -11‰ to -5‰, reflect the outgassing of already light 12c of meteoric and soil derivation (pentec o s t, 2005), since the preferential uptake of 1 2c by green plants through photosynthetic action does not appear to affect the overall carbon distribution and removal in a freshwater system (usdowski et al., 1979; chafetz & lawrence, 1994; andrews et al., 2000). the δ18o (pdb) values ranging from -3‰ to -12‰, register cool temperature and saturation levels of the spring waters (gonfiantini et al., 1968; usdowski et al., 1979; turi ,1986; chafetz & lawrence, 1994) and consequently record the properties of the local climatic regime (horvatincic et al., 2003). stable isotopes value of the calcareous tufa essentially reflects the composition of the parent karstic water which ionic content mainly results from isotopically light, soil derived co2 contained in recharging meteoric waters. a minor input of heavier recycled 1 3c derives from dissolution of the marine carbonate bedrock (ho rv a t i n c i c et al., 2003), but has no influence in the isotopic distribution (fig. 5). consequently, the specific distribution of the stable isotopic values of calcareous tufa, while attesting the cool, fresh-water karstic and ultimately meteoric imprint of the carbonate parent fluids, corroborates also the dominantly passive biological contribution to the precipitation of calcium carbonate, and cool climatic conditions at the time of deposition. 5. conclusion travertine and calcareous tufa are flowstones that form under open-air conditions at the emergence of thermal springs or along fluvial valleys/cool water springs systems: two distinct geomorphologic settings fed from groundwaters that after a non comparable recharge/circulation pathway, emerge with different mineral content and different temperatures. on the surface the flow of warm-to-hot or cool/ambient temperature waters produce contrasting biological responses: a bare white desert around thermal springs or luxuriant vegetation along the stream valley. the lithologic features and isotopic signature of travertine and calcareous tufa, closely record the specific physico-chemical composition and biologic imprint of the related depositional environments. criteria for the univocal definition of calcareous tufa and travertines can be acquired through the comparison of the characteristics of the respective present day depositional settings, the lithologic/petrographic features and related isotopic signature of the carbonates in formation. travertines deposited in thermal spring systems, are characterized by warm-to-hot water supersaturated with calcium bicarbonate and free co2. outgassing and vaporizing/cooling processes combined with turbulence and velocity of the flow control the shape and distribution of the sedimentary bodies. they consist of well bedded, finely laminated, dominantly crystalline crusts often associated with calcified-bubble facies, paperthin rafts, and in the distal part, with peloidal aggregates and bacterial/cyanobacterial laminites. travertine depositional features and the positive field of distribution of δ13c register the dominant control of the physico-chemical parameters: temperature, evaporation and outgassing, on calcite precipitation. the hot, supersaturated carbonate waters rising from deep subsurface circulation through a network of extensional faults are in part of meteoric derivation and in part of recycled, juvenile geothermic/magmatic provenance. calcareous tufa develop in fluvio-palustrine systems fed by cool, carbonate-rich waters mainly of karstic and meteoric origin. in evident contrast with the thermal system where life is limited to mainly heatloving bacteria, in the fluvio/palustrine conditions luxuriant vegetation of microand macrophytes results from the opportunistic colonization of water-rich environments where large amounts of co2 are available. the irregular distribution of the sedimentary bodies along the valleys and their petrologic features, reflect the physico-chemical properties of the water and hydrodynamics of the flow. highly porous, poorly bedded, irregularly staked phytohermal or stromatolitic buildups and lenticular layers of unsorted phytoclastic sands and/or mud-supported pond-related sediments, characterize the tufa lithofacies. microcrystalline calcite, peloidal aggregates and/or limpid spar are the dominant fabrics. the negative field of distribution of stable isotopes values of calcareous tufas essentially reflects the parental relationships with the meteoric and soil-derived karstic waters and a minor input of heavier recycled carbon. the vegetation involvement in the formation of calcareous tufa appears to be limited to a passive role of support more than an active involvement in the chemical biogenic precipitation of calcium carbonate. accordingly, the development of calcareous tufa appears to be controlled by the availability of meteoric water and ultimately by local/global climatic conditions. facies analysis and petrographic characterization 132 a. gandin & e. capezzuoli of the present day terrestrial limestones forming from flowing waters in subaerial settings, evidence the unmistakable differences in fabrics, lithofacies and biologic involvement in the deposition of travertine and calcareous tufa. likewise, the fields of distribution of the δ13c and δ1 8o isotopic values of recent deposits of well known origin appear to be rather well correlated with the distinctive environmental conditions and petrographic features of each group: they reflect unrelated physico-chemical conditions of the fluids feeding the two depositional systems. the distribution field of the stable isotopes of tra133 fig. 4 combined plot of δ18o (smow/pdb) and δ13c (pdb) values derived from tufa and speleothems in formation, sampled in selected localities of central-north europe. data sources: poland (pazdur et al., 1988); dinaric area (horvatinč ić et al., 2003); uk/belgium (andrews et al., 1994; thorpe et al., 1980; janssen & swennen, 1997; garnett et al., 2004); spain (peña et al., 2000; sancho et al., 1997; arenas et al., 2000; andrews et al., 2000); trentino (italy) (frisia, 2003); postojna karst (horvatinčić et al., 2003); westerhof (germany) (usdowski et al., 1979). diagramma combinato dei valori di δ18o (smow/pdb) e δ13c (pdb) ricavati da calcareous tufa e speleotemi in formazione, campionati in alcune località dell'europa centro-settentrionale. dati ricavati da: polonia (pazdur et al., 1988); area dinarica (horvatinčić et al., 2003); gb/belgio (andrews et al., 1994; thorpe et al., 1980; janssen & swennen, 1997; garnett et al., 2004); spagna (peña et al., 2000; sancho et al., 1997; arenas et al., 2000; andrews et al., 2000); trentino (italia) (frisia, 2003); grotte di postumia (horvatinčić et al., 2003); westerhof (germania) (usdowski et al., 1979). travertine versus calcareous tufa ... vertine appears to be wider than that of calcareous tufa. it probably reflects the more ample range of temperature, dept of circulation, volcanic or groundwater sources of the travertine-related waters, while the karstic-meteoric waters of the calcareous tufa records more uniform climate-related conditions. acknowledgments we would like to thank the anonymous reviewers for pertinent suggestions that improved the final version of this paper. this work has been financially supported by the university of siena 2005 par grant (a. gandin). 134 fig. 5 combined plot of δ18o (smow/pdb) and δ13c (pdb) values derived from carbonates presently forming in terrestrial (travertine, calcareous tufa, speleothems) and marine (skeletal-ooid sediments and pelagic muds) environments and from lithified marine limestones. data sources for travertine see fig. 2. data sources for tufa and speleothems see fig. 4. data sources for marine limestones, recent calcareous sediments and meteoric cements: nelson & smith (1996 with references therein). diagramma combinato dei valori δ18o (smow/pdb) e δ13c (pdb) dei carbonati attualmente in formazione in ambiente continentale (travertini, calcareous tufa, speleotemi), e marino (depositi scheletrici, ad ooidi e fanghi pelagici): sono inclusi per confronto anche i valori dei calcari marini litificati e dei cementi di origine meteorica. per dati sui travertini vedi fig. 2. per i dati sui calcareous tufa e gli speleotemi vedi fig. 4. per i carbonati marini, e i cementi meteorici vedi nelson & smith (1996) cum bibl. a. gandin & e. capezzuoli references altunel e. (2005) travertines: neotectonic indicators. in: özkul m., yagiz s., jones b. (eds). travertine, proceedings of 1s t international symposium on travertine, september 21-25, 2005, denizliturkey, 120-127, kozan ofset, ankara. andrews j.e. (2005) paleoclimatic records from stable isotopes in riverine tufas: synthesis and review. earth-science reviews, 75, 85-104. andrews j.e., pedley h.m. & dennis p.f. (1994) stable isotope record of palaeoclimate change in a british holocene tufa. holocene, 4, 349-355. an d r e w s j.e., pe d l e y h.m. & de n n i s p.f. (2000) palaeoenvironmental records in holocene spanish tufas: a stable isotope approach in search of reliable climatic archives. sedimentology, 4 7, 961978. arenas c., gutiérrez f., osàcar c. & sancho c. (2000) sedimentology and geochemistry of fluvio-lacustrine tufa deposits controlled by evaporite solution subsidence in the central ebro depression, ne spain. sedimentology, 47, 883-909. barazzuoli p., costantini a., fondi r., gandin a., ghezz o c., la z z a r o t t o a., mi c h e l u c c i ni m., sa l l e o l i n i m. & salvadori l. (1988) i travertini di rapolano sotto il profilo geologico e geologico-tecnico. in co l i v. (a cura di): il travertino di siena, ed. al.sa.ba grafiche, siena, 26-35. brancaccio l., d'argenio b., ferreri v., preite martinez m., stanzione d. & turi b. (1986) caratteri tessiturali e geochimica dei travertini di rocchetta a volturo (molise) . bollett ino della società geologica italiana, 105, 265-277. brogi a. & capezzuoli e. (2008) travertine deposition and faulting: the fault-related travertine fissureridge at terme s. giovanni, rapolano terme ( i t a l y ). int. j. earth sci. (geol rundsch), doi 10.1007/s00531-007-0290-z brogi a., capezzuoli e., costantini a., gandin a. & lazzarotto a. (2005) tectonics and travertines relationships in the rapolano terme area (northern apennines, italy). in: özkul m., yagiz s., jones b. (eds). travertine, proceedings of 1s t i n t e r n a t i o n a l symposium on travertine, september 21-25, 2005, denizli-turkey, 142-148, kozan ofset, ankara. bu c c i n o g., d'ar g e n i o b., fe r r e r i v., br a n c a c c i o l . , ferreri m., panichi c. & stanzione d. (1978) i travertini della bassa val tanagro (campania): studio geomorfologico, sedimentologico e geochimico. bollettino della società geologica italiana, 9 7, 617-646. capezzuoli e. & gandin a. (2004) i “travertini” in italia: proposta di una nuova nomenclatura basata sui caratteri genetici. il quaternario, 17(2/1), 273-284. ca p e z z u o l i e. & ga n d i n a. (2005) facies distribution and microfacies of thermal-spring travertine from t u s c a n y. in: m. ozkul, s. yagiz, b. jones eds., travertine, proceedings of 1s t i n t e r n a t i o n a l symposium on travertine, september 21-25, 2005, denizli-turkey, 43-49, kozan ofset, ankara. ca p e z z u o l i e., ga n d i n a. & sa n d r e l l i f. (2008) evidence of associated deposition of travertine and calcareous tufa in the quaternary carbonates of valdelsa basin (tuscany). il quaternario, 21(1b), 113-124. chafetz h.s. & folk r.l. (1984) travertines: depositional morphology and the bacterially constructed costituents. j. sedim. petrol., 54, 289-316. ch a f e t z h.s. & la w r e n c e j.r. (1994) stable isotopic variability within modern travertines. géographie phys. et quatern., 48(3), 257-273. cilla g., coltorti m. & dramis f. (1994) holocene fluvial dynamics in mountain areas: the case of the river esino (appennino umbro-marchigiano). geografia fisica e dinamica quaternaria, 17, 163174. d'argenio b. & ferreri v. (1988) ambienti deposizionali e litofacies dei travertini quaternari dell'italia c e n t r o m e r i d i o n a l e . memorie della società geologica italiana, 41, 861-868. d'argenio b., ferreri v., stanzione d., brancaccio l. & fe r r e r i m. (1983) i travertini di pontecagnano (campania): geomorfologia, sedimentologia, geoc h i m i c a . bollett ino della società geologica italiana, 102, 123-136. du b a r m. (2006) recherche et interpretation climatique des microcycles du concretionnement travertineux de l 'aqueduc romain de frejus (var, france). quaternaire paris, 17, 79-85. faccenna c., funiciello r., montone p., parotto m. & vo l t a g g i o m. (1994) an example of late pleistocene strike-slip tectonics: the acque albule basin (tivoli, latium). memorie descrittive della carta geologica d'italia, xlix, 63-76. ferreri v. (1985) criteri di analisi di facies e classificazione dei travertini pleistocenic i dell 'i ta lia m e r i d i o n a l e. rend. acc. scienze fis. e mat., 5 2, napoli. 47 pp. ford t. d. & pedley h.m. (1996) a review of tufa and travertine deposits of the world. earth sci. rev., 41, 117-175. fo u k e b.w., fa r m e r j.d., de s ma r a i s d.j., pr a t t l . , sturchio n.c., burns p.c. & discipulo m.k. (2000) depositional facies and aqueous-solid geochemistry of travertine-depositing hot spring (angel terrace, mammoth hot spring, yellowstone national park, u.s.a.). journal of sedimentary research, 70(3), 565-585. friedman i. (1970) some investigation of the deposition of travertine from hot springs-i. the isotopic chemistry of a travertine-depositing spring. geoch. cosmoch. acta, 34, 1303-1315. fr i s i a s. (2003) le tessiture negli speleotemi. studi trent. sci. nat., acta geol., 80, 85-94. gandin a., capezzuoli e. & ciacci a. (2006) the stone of the etruscan inscribed steles from the valdelsa area (siena, italy). in: ma g g e t t i m. & me s s i g a b . (eds.). geomateria ls in cultural heri tage. geological society, london, special publications, 257, 273-282. garnett e.r., andrews j.e., preece r.c. & dennis p.f. (2004) climatic change recorded by stable isotopes and trace elements in a british holocene tufa. journal of quaternary science, 19, 251-262. glime j.m. & vitt d.h. (1984) the physiological adaptations of aquatic musci. lindbergia, 10, 41-52. go n f i a n t i n i r., pa n i c h i c. & to n g i o r g i e. (1968) 135travertine versus calcareous tufa ... isotopic disequilibrium in travertine deposition. earth and planetary science letters, 5, 55-58. guo l., andrews j., riding r., dennis p. & dresser q. (1996) possible microbial effects on stable carbon isotopes in hot-spring travertines. j. sed. res., 66(3), 468-47. guo l. & riding r. (1998) hot-spring travertine facies and sequences, late pleistocene, rapolano terme, italy. sedimentology, 45, 163-180. gu o l. & ri d i n g r. (1999) rapid facies change in holocene fissure ridge hot spring travertines, rapolano terme, italy. sedimentology, 46, 11451158. hammer o. dysthe d.k. & jamtveit b. (2007) the dynamics of travertine dams. earth and planetary science letters, 256, 258-263. ha n c o c k pl., ch a l m e r s rml, al t u n e l e., ça k i r z . (1999) travitonics: using travertines in active fault studies. journal of structural geology, 2 1, 903-916. ho r v a t i nčić n., br o nić i .k. & ob e lić, b. (2003) differences in the 1 4c age, δ1 3c and δ1 8o o f holocene tufa and speleothems in the dinaric k a r s t . palaeogeography, palaeoclimatology, palaeoecology, 193, 139-157. janssen a. & swennen r. (1997) petrography and geochemistry of the travertine deposit at treignes (s. b e l g i u m ) . bulletin de la societe belge de geologie, 106, 97-115. jimenez de cisneros c., caballero e. & jimenez-lopez c. (2006) δ1 8o and δ13c of modern/ancient travetines from a thermal spring (alicun de las torres, southern spain). geoacta, 5, 13-24. ju l i à r. (1983) t r a v e r t i n e s . in: p.a. sc h o l l e , d . g . be b o u t, c.h. mo o r e (eds): carbonate depositional environments. aapg memoir, 33, 62-72. merz-preiss m. & riding r. (1999) cyanobacterial tufa calcification in two freshwater streams: ambient environment, chemical thresholds and biological processes. sedimentary geology, 126 (1-4), 103124. minissale a., kerrik d., magro g., murrell m.t., paladin i s., ri h s s,. st u r c h i o n., ta s s i f. & va s e l l i o . (2002) structural hydrogeological chemical and climatic parameters affecting the precipitation of travertines in the quaternary along the tiber valley, north of rome. earth planet. sci. lett., 2 0 3, 709-728. ne l s o n c.s. & sm i t h a.m. (1996) stable oxygen and carbon isotope compositional fields for skeletal and diagenetic components in new zealand cenozoic non tropical carbonate sediments and limestones: a synthesis and review. new zealand journal of geology and geophysics, 39, 93-107. özkul m., varol b. & alçiçek m.c. (2002) depositional environments an petrography of denizli travertine. bullettin of the mineral research and exploration, 125, 13-29. pazdur a., pazdur m.f. starkel, l. & szulc j. (1988) stable isotopes of holocene calcareous tufa in southern poland as palaeoclimatic indicators. quaternary research, 30, 177-189. pe d l e y h.m. (1990) classification and environmental models of cool freshwater tufas. sedim. geol., 68, 143-154. pedley h.m., andrews j., ordòñez delgado s., garcia del cura m.a., gonzàlez martìn j.a. & taylor d. (1996) does climate control the morphological fabric of freshwater carbonates? a comparative study of holocene barrages tufas from spain and b r i t a i n. paleogeography, paleoclimatology, paleoecology, 121, 239-257. pe ñ a j.l., sa n c h o c. & lo z a n o m.v. (2000) c l i m a t i c and tectonic significance of pleistocene and holocene tufa deposits in the mijares river canyon, eastern iberian range, northeast spain. earth surface processes and landforms, 2 5, 1403-1417. pentecost a. (1995) the quaternary travertine deposits of europe and asia minor. quat. sci. rev., 1 4, 1005-1028. pentecost a. (2005) travertine. 445 pp. springer pe n t e c o s t a. & vi l e s h.a. (1994) a review and reassessment of travertine classification. geographie physique et quaternaire, 48, 305-314. ri d i n g r. (1991) classi fication of microbial carbonates. in: riding r. (ed) : calcareous algae and stromatolites. 21-51, springer-verlag. sancho c., peña j.l. & melendez a. (1997) controls on holocene and present-day travertine formation in the guadalaviar river (iberian chain, ne spain). zeitschrift für geomorphologie, 41, 289-307. sh i p t o n z.k., ev a n s j.p., ki r s c h n e r d., kolesar p . t . , wi l l i a m s a.p. & he a t h j.e. (2004) analyses of c o2 leakage through “low-permeability” faults from natural reservoirs in the colorado plateau, east-central utah. journal of geological society of london, special publication, 233, 43-58. si b s o n r.h. (2000) fluid involvement in normal faulting. journal of geodynamics, 29, 469-499. th o r p e p.m., ot l e t r.l. & sw e e t i n g m.m. (1980) hydrobiological implications of 14c profiling of uk tufa. radiocarbon, 22, 897-908. turi b. (1986) stable isotope geochemestry of travertines. in: p. fritz & j.c. fontes (eds) handbook of environmental isotope geochemestry. 2 . terrestrial environment, b. elsevier, amsterdam, pp. 207-238. us d o w s k i e. , ho e f s j. & me n s c h e l g. (1979) relationship between 13c and 18o fractionation and changes in major element composition in a recent calcite-depositing spring a model of chemical variations with inorganic caco3 p r e c i p i t a t i o n. earth and planetary science letters, 42, 267-276. vi o l a n t e c., fe r r e r i v. & d'ar g e n i o b. (1996) modificazioni geomorfiche controllate dalla deposizione di travertino. il quaternario, italian journal of quaternary sciences, 9(1), 213-216. vi o l a n t e c., fe r r e r i v. & d'ar g e n i o b. & go l u b i c s . (1994) quaternary travertines at rocchetta a volturno (isernia, central italy). facies analysis and sedimentary model of an organogenic carbonate system. i.a.s. 15th reg. meet., april, 1994, ischia, guide book to the field trip, 3-23. 136 ms. ricevuto il 22 febbraio 2008 testo definitivo ricevuto il 21 marzo 2008 ms. received: february 22, 2008 final text received: march 21, 2008 a. gandin & e. capezzuoli pag125_136 gandin capezz imp.girotti pplliioo--pplleeiissttoocceennee ssttrraattiiggrraapphhyy aanndd rreellaattiioonnss bbeettwweeeenn mmaarriinnee aanndd nnoonn--mmaarriinnee ssuucccceessssiioonnss iinn tthhee mmiiddddllee vvaalllleeyy ooff tthhee ttiibbeerr rriivveerr ((llaattiiuumm,, uummbbrriiaa)) ooddooaarrddoo ggiirroottttii11--22 && mmaarrccoo mmaanncciinnii11 1 dipartimento di scienze della terra, università degli studi di roma “la sapienza” piazzale aldo moro 5, 00185 roma odoardo.girotti@uniroma1.it; marco.mancini@uniroma1.it 2 cnr igag co dipartimento di scienze della terra, università degli studi di roma “la sapienza”. abstract the middle valley of the tiber river (mvt) corresponds to the “paglia-tevere graben”, a “neoautochthonous” basin developed since the latest early pliocene. the basin is in part linked with the intrapenninic tiberino and rieti basins to the east, and with the roman basin to the south. the filling is mostly made up of plio-pleistocene marine deposits, unconformably overlaying the meso-cenozoic substratum. two outcropping 3rd order depositional sequences have been recognised: 1) the older is composed of lower pliocene-earliest upper pliocene shelfal clays and sands (g. puncticulata and g. aemiliana chronozones) and rarer continental deposits; 2) the younger is late gelasian-santernian in age (g. inflata and g. cariacoensis-b. elegans marginata chronozones) and mostly corresponds to the “chiani-tevere formation”, composed of neritic clayey-sandy sediments interfingered with fluvial-deltaic gravelly-sandy deposits. the correlation between marine and non-marine deposits is based both on physical-stratigraphic observations and data (lithostratigraphy, facies analysis, sequence stratigraphy) and on their integration with biostratigraphic (foraminifera) and magnetostratigraphic data and with the numerical values of the 87sr/86sr ratio measured on mollusc shells, for the marine deposits, and with biochronological data (freshand brackish-water molluscs and ostracods, mammals) for the non-marine and transitional deposits. as for the younger successions from the latest early pleistocene to holocene, which are characterised by travertines and gravelly fluvial terraced deposits, the correlation with the marine successions of the roman basin is indirect and mostly based on biochronology and on relations between sedimentary and volcanic units. riassunto la media valle del fiume tevere (mvt) tra orvieto e fiano rappresenta un’area ideale per lo studio delle correlazioni tra depositi marini e continentali plio-pleistocenici. infatti essa corrisponde al “bacino del paglia-tevere”, a prevalente sedimentazione marina, parzialmente contiguo ad est ai bacini intrappenninici di rieti e tiberino e al bacino romano a sud. viene intodotto un nuovo schema stratigrafico, che aggiorna il precedente di ambrosetti et al. (1987) e pone in evidenza la presenza di cicli sedimentari di iii e iv ordine controllati dall’evoluzione tettonico-regionale tramite fasi di subsidenza e di sollevamento. la correlabilità tra bacini si basa su: 1) dati stratigrafico-fisici ottenuti mediante rilevamenti litostratigrafici e analisi di facies; 2) biostratigrafia a foraminiferi; 3) biocronologia a mammiferi e molluschi continentali; 4) magnetostratigrafia delle successioni marine e datazioni ar/ar e k/ar di unità vulcaniche; 5) nuovi dati stratigrafico-isotopici ottenuti mediante misure del rapporto 87sr/86sr su gusci di molluschi e idrozoi. la fase di subsidenza è caratterizzata da due cicli sedimentari marino-continentali di iii ordine. il primo ciclo (tardo zancleanogelasiano iniziale) è composto dai depositi terrigeni marini delle “unità di fabro”, “formazione di tenaglie-fosso san martino” e “unità di città della pieve”, cui localmente si intercalano sedimenti fluvio-lacustri. il secondo ciclo (tardo gelasiano-santerniano) è caratterizzato dalla eteropia tra i depositi marini di piattaforma e transizionali della “formazione del chiani-tevere” e i depositi fluviali della “formazione di santa maria di ciciliano” e della “formazione di poggio mirteto”. in particolare all’interno della formazione marina, sono stati riconosciuti tre grandi episodi progradazionali intercalati a fasi trasgressive ed evidenziati dai sedimenti ghiaiosi deltizi dei “membri di civitella san paolo”, “torrita tiberina”, “vasanello”. il primo episodio progradazionale ricade al passaggio gelasiano-santerniano, mentre i successivi sono di età santerniana. la fase regionale di sollevamento (emiliano-olocene) è caratterizzata dai depositi misti carbonatico-terrigeni della “unità di giove” (pleistocene inferiore pp.), da vulcaniti, e dai depositi terrazzati fluviali ghiaioso-sabbiosi delle “unità di civita castellana” (pleistocene inferiore pp.-pleistocene medio pp.), “graff ignano” (pleistocene medio), “rio fratta” (tardo pleistocene medio) e “sipicciano”(pleistocene superiore). sulla base dei dati di terreno (biocronologia, rapporti con unità vulcaniche) e di interpretazioni paleogeografiche si ipotizzano correlazioni tra le unità continentali della mvt e le unità marino-transizionali dell’area romana, per il tardo pleistocene inferiore e l’inizio del pleistocene medio. keywords: late pliocene, early pleistocene, latium, umbria, stratigraphy, paleogeography, sr isotope stratigraphy. parole chiave: pliocene superiore, pleistocene inferiore, lazio, umbria, stratigrafia, paleogeografia, stratigrafia isotopica dello sr il quaternario italian journal of quaternary sciences 1166(1bis), 2003, 89-106 11.. iinnttrroodduuccttiioonn the middle valley of the tiber river (mvt) represents a good example of how to correlate marine with non-marine successions, using both direct field observations and analytical techniques like facies analysis, paleontologic and isotope-stratigraphic analyses and their integration, for chronologic and paleoevironmental purposes. the mvt is located at the border between latium and umbria and widens up to 60 km, between the orvieto and fiano towns (fig. 1). structurally it corresponds to the “paglia-tevere graben” (funiciello et al., 1981), a nnw-sse trending extensional basin developed since the late early pliocene, in concomitance with the globorotalia puncticulata chronozone (barberi et al., 90 o. girotti & m. mancini fig. 1 geological map of the mvt. legend: a) rreecceenntt aalllluuvviiaall ddeeppoossiittss (holocene). b) ssiippiicccciiaannoo uunniitt: iv order fluvial terrace of the tiber river (late pleistocene). c) rriioo ffrraattttaa uunniitt:: iii order fluvial terrace (middle pleistocene). d) ggrraaffffiiggnnaannoo uunniitt: ii order fluvial terrace (middle pleistocene). e) vvoollccaanniicc aanndd vvoollccaannoo--sseeddiimmeennttaarryy ssuucccceessssiioonnss ooff tthhee 22nndd vvoollccaanniicc pphhaassee (middle pleistocene). f) cciivviittaa ccaasstteellllaannaa uunniitt:: i order fluvial terrace (early-middle pleistocene). g) ppyyrrooccllaassttiitteess aanndd llaavvaass ooff tthhee 11sstt vvoollccaanniicc pphhaassee (early pleistocene). h) ggiioovvee aanndd aaccqquuaassppaarrttaa ffoorrmmaattiioonnss: travertines (early pleistocene). i) cchhiiaannii--tteevveerree ffoorrmmaattiioonn: marine, fine-grained terrigenous deposits (late pliocene-early pleistocene). j) cchhiiaannii--tteevveerree ffoorrmmaattiioonn: transitional, coarse-grained terrigenous (cciivviitteellllaa ss.. ppaaoolloo,, ttoorrrriittaa ttiibbeerriinnaa and vvaassaanneelllloo mmeemmbbeerrss) and carbonatic deposits (late pliocene-early pleistocene). k) ppooggggiioo mmiirrtteettoo ffoorrmmaattiioonn: fluvial deposits (late pliocene-early pleistocene). l) iinnttrraammoonnttaannee llaaccuussttrriinnee aanndd aalllluuvviiaall ddeeppoossiittss (middle pliocene-early pleistocene). m) tteennaagglliiee--ffoossssoo ss.. mmaarrttiinnoo ffoorrmmaattiioonn: marine deposits (middle-late pliocene). n) ccaarrbboonnaattiicc aanndd ssiilliicciiccllaassttiicc ssuucccceess-ssiioonnss (trias-miocene). o) normal fault. p) thrust. q) stratigraphic log. 1994). it is bordered to the east by the mt pegliaamerini-narni-sabini-lucretili mts ridge, where triassic to miocene marine, carbonatic and siliciclastic successions crop out. the western borders of the basin are the castell’azzara-mt razzano ridge (barberi et al., 1994), almost totally overlain by the quaternary volcanites of the vulsini, cimini and sabatini mts volcanic districts, and the mt soratte horst. the basin is prevalently filled with plio-pleistocene marine terrigenous deposits. however, coeval non-marine and transitional terrigenous and carbonatic deposits extensively crop out along the western margin of the mt peglia-lucretili mts ridge (ambrosetti et al., 1987; barberi et al., 1994; girotti & piccardi, 1994), while pleistocene volcano-sedimentary successions are well exposed west of the tiber river (fig. 1). the present paper represents an update on the information about the neogene-quaternary stratigraphy of the mvt, both derived from the re-examinations of previously collected and published data and from new geological mapping and stratigraphic, sedimentologic and paleontologic analyses (mancini, 2000; mancini et al., 2001). in particular this work deals with: 1) the introduction of a new stratigraphic scheme; 2) detailed analyses of the relationships among late pliocene-early pleistocene marine, transitional and non-marine deposits; 3) paleogeographic reconstructions of the mvt and surrounding areas during the late pliocene-earliest middle pleistocene. 22.. pprreevviioouuss wwoorrkkss the study of the relations between pliopleistocene marine and non-marine deposits in the umbria-latium region was a topic for geologists since the late xix century, with particular interest in the stratigraphic, paleontologic and geomorphic features (tuccimei 1888; 1889; 1891; 1895; clerici 1895; 1929). in fact the “villafranchiano” stage was introduced for the first time in central italy just in the mvt, near poggio mirteto (tuccimei, 1889), after the discovery of a rich mammalian and molluscan fauna characterising that period (1). the non-marine deposits bearing such an assemblage were considered pliocene in age and overlaying, with angular unconformity, “astian” marine deposits (tuccimei, 1888; 1895). on the other hand, clerici (1895) disproved the angular unconformity proposing the lateral continuity between the villafranchian and the marine deposits. the heteropic relations between non-marine and marine deposits were recurrently considered in order to understand the geology of the tiber river’s valley and its surrounding areas. in particular, discoveries of marine and transitional sediments within fluvial and lacustrine successions near terni (terrenzi, 1886) and todi (principi, 1922), based on malacological observations, should be mentioned. therefore, the possibility of correlating marine and non-marine deposits was later put in evidence by discoveries of fresh-water molluscs and mammals within marine and nearshore successions and of brackish-water assemblages into non-marine successions, in particular in the roman area (bonadonna, 1968; girotti, 1972) and in the south-western tiberino basin (ippolito 1947; girotti, 1967; conti & girotti, 1977; ambrosetti et al., 1987), which are laterally continuous to the mvt southward and eastward respectively. progress in the stratigraphical knowledge of the mvt, mainly due to micropaleontological studies (ambrosetti et al., 1987; buonasorte et al., 1991), led to the introduction of two marine sedimentary cycles (fig. 2): 1) the first cycle developed during the latest early pliocene and the earliest late pliocene, between the g. puncticulata and g. aemiliana zones. it includes the “argille di fabro”, the “sabbie a flabellipecten” and the “conglomerato di città della pieve” units (ambrosetti et al., 1987). 2) the second cycle is chronologically limited to the santernian and corresponds to the “argille sabbiose del chiani-tevere” unit (asct), which indicates marine and brackish-water environments, laterally continuous with the “complesso argilloso-sabbioso” unit 91plio-pleistocene stratigraphy ... (cas), of fluvial and lacustrine environment (ambrosetti et al., 1987). the two cycles are separated by an unconformity of regional importance known as the “fase erosiva dell’acquatraversa” (bonadonna, 1968) coinciding with the g. inflata zone. as a result of the new stratigraphic setting and mapping, most of the marine deposits, previously thought of pliocene age, are actually early pleistocene, while the heteropic relations among fully marine, transitional and non-marine units were detected only within the second sedimentary cycle (ambrosetti et al., 1987; piccardi, 1993). 33.. mmeetthhooddoollooggyy thirty surface stratigraphic sections (fig. 1) have been analysed using the standard methods of field geology and facies analysis (miall, 2000), examining in particular their lithologic, textural and paleontologic features. micropaleontologic data have been obtained by collecting 73 samples of pelite or sand (mancini, 2000), for qualitative analyses on micro-molluscs and forams, and have been added to the bibliographic data about the same topic (ambrosetti et al., 1987; carboni et al., 1993; piccardi, 1993; di bella, 1994; carboni & di bella, 1994; carboni & di bella, 1996; ciangherotti et al., 1998). each sample, having a 200 cm3 volume, was treated with a h2o and h2o2 solution, and washed through a 125 µm sieve. the >125 µm size fraction of the wash residue was considered for the collection and recognition of the microfauna; up to 300 specimens for sample were counted. the biostratigraphic scheme used is from cita (1975) and iaccarino (1985), while the chronostratigraphic scheme is based on sprovieri (1993) and cita & castradori (1995). twelve measures of the 87sr/86sr ratio on fragments of marine molluscs and hydrozoa have been carried out by prof. mario barbieri, at the “istituto di geologia ambientale e geoingegneria” (cnr-rome), for chronostratigraphic purposes; the analytical method is described in barbieri et al. (1998). several radiometric (arias et al., 1980; borghetti et al., 1981; sollevanti, 1983; laurenzi & villa, 1987; cioni et al., 1993; barberi et al., 1994; perini et al., 1997) and magnetostratigraphic (florindo & sagnotti, 1995; borzi et al., 1998) data were used to directly date several volcanic and sedimentary units. 44.. ssttaattiiggrraapphhiicc sseettttiinngg ooff tthhee mmvvtt the sedimentary units decribed below are of the lithostratigraphic and of the ubsu type (salvador, 1994). in part they have already been introduced, while the others are presented here for the first time; in both cases they are going to be formalised. such units are separated on the basis of their ages, also considering the sedimentary cyclicity previously introduced (ambrosetti et al., 1987; bossio et al., 1998) and the regional geological evolution with reference to the latial volcanism and its cyclicity (barberi et al., 1994; mancini, 2000). consequently, these units are grouped into: latest early pliocene-earliest late pliocene units, latest late 92 o. girotti & m. mancini f ig . 2 s tr at ig ra ph ic s ch em e of th e m v t 93 pliocene-earliest early pleistocene units, middle early pleistocene-earliest middle pleistocene units, middle pleistocene-holocene units. 44..11.. llaatteesstt eeaarrllyy pplliioocceennee--eeaarrlliieesstt llaattee pplliioocceennee uunniittss these units crop out along the western margin of the mt peglia and of the northern amerini mts, south of orvieto, and near the mt soratte (fig. 1). they constitute the first mvt “neoautochthonous” sedimentary cycle and are: the fabro formation, the tenaglie-fosso san martino formation and the città della pieve unit. 44..11..11.. tthhee ffaabbrroo ffoorrmmaattiioonn the fabro formation, already known as argille di fabro (ambrosetti et al., 1987), crops out in the northernmost mvt along the paglia river banks. it is composed of blue-grey, marine, sandy clays, mostly massive or tabular bedded. the strata, which are tectonically tilted, gently dip toward east, 8-10°. the thickness of the formation is up to 100 metres. the malacologic content, which was fully detailed by malatesta (1974), indicates the neritic circalittoral stage. the presence of g. puncticulata and g. aemiliana is indicative of the early-middle pliocene age. non-marine and presumably transitional deposits were recently discovered near orvieto, in the camorena site (barberi et al., 1994), and near fabro (petronio et al., in press). these deposits are interlayered with the marine ones, at the base of the g. aemiliana zone (about 3.0 ma). the malacologic content suggests that such sediments are of fluvial and lacustrine environments and of early villafranchian age (2) (ciangherotti et al., 1998; petronio et al., in press). 44..11..22.. tthhee tteennaagglliiee--ffoossssoo ssaann mmaarrttiinnoo ffoorrmmaattiioonn the tenaglie-fosso san martino formation crops out in the mt peglia and northern amerini mts areas, where it corresponds to the sabbie a flabellipecten formation (ambrosetti et al., 1987), and west of mt soratte. it unconformably overlays the meso-cenozoic substratum, vertically continuous above the fabro formation. its maximum thickness is up to 200 m. the formation is commonly composed of massive or tabular stratified sands, in some cases well cemented by calcium carbonate. structures like hummocky and swaley cross stratification and gravelly lenses, few metres thick, are common. in the mt soratte area the sands laterally pass to well cemented, oligomittic, poorly sorted conglomerates and breccias, almost exclusively calcareous. the clast size ranges from a few centimetres up to 1 metre. the paleontologic content is very rich and composed of pecten (flabellipecten) flabelliformis, chlamys (gigantopecten) latissima, terebratula ampulla, ostrea spp., balanidae, bryozoa and rhodophyceae. the foraminifer assemblage is characterised by g. aemiliana, bulimina marginata and amphistegina spp., typical of the late middle pliocene and of the earliest late pliocene. the sedimentologic and paleontologic data indicate the shoreface and the offshore-shoreface transition environments. 44..11..33.. tthhee cciittttàà ddeellllaa ppiieevvee uunniitt this unit, already known as conglomerato di città della pieve (ambrosetti et al., 1987), crops out in few sites of the northern mvt. it is composed of well cemented cobblestones, up to 10 metres thick, conformably overlaying the tenaglie-fosso san martino formation. these rudites are interpreted as gravelly beach deposits (ambrosetti et al., 1987). 44..22.. tthhee llaatteesstt llaattee pplliioocceennee--eeaarrlliieesstt eeaarrllyy pplleeiissttoo--cceennee uunniittss such units, which form the second “neoautochthonous” marine and non-marine cycle, widely crop out in the entire mvt. the units described below are: the chiani-tevere formation, the poggio mirteto formation and the santa maria di ciciliano formation. 44..22..11.. tthhee cchhiiaannii--tteevveerree ffoorrmmaattiioonn the chiani-tevere formation, which corresponds to the argille sabbiose del chiani-tevere (ambrosetti et al., 1987), is composed of marine, transitional and more limited non-marine deposits. it unconformably overlays the tenaglie-fosso san martino formation and the meso-cenozoic substratum (fig. 3). its maximum thickness in outcrop is up to 350 m, but as the base rarely crops out the formation may be thicker. the marine deposits are composed of blue-grey sandy clays, commonly massive or planar bedded, vertically passing to massive sandy silts and fine silty sands, where structures like hummocky cross stratification and turbiditic beds are common. such fine lithofacies vertically pass to coarse grained sands, with frequent amalgamated hummocky and swaley cross stratifications and trace fossils like scolicia and thalassinoides. strata are commonly sub-horizontal. the entire succession of lithofacies described above, which is well exposed in the northern mvt, indicates a regressive trend from inner shelf to shoreface deposits (mancini, 2000). east of mt soratte a few metres thick, bioclastic calcarenitic level (fig. 4), almost totally composed of chaotically amalgamated nearshore molluscs, echinids and corals, and well rounded pebbles, covers the underlaying coastal and fluvial deposits (see the discussion below). it is interpreted as a transgressive lag deposit, which is laterally continuous to the cemented sands, very rich in forams, that crop out at vallericca (carboni et al., 1993) few km far from the mvt southward (fig. 4). still in the vallericca section, a several decimetres thick horizon of resedimented pyroclastites also crops out (arias et al., 1980) (fig. 4), which is placed within the b. marginata zone (carboni et al., 1993). this level is dated 2.1 ± 0.2 ma by fission track analyses on volcanic glass shards (arias et al., 1980), and 1.8 ± 0.3 ma by analyses on zircons (arias et al., 1990). furthermore, recent magneto-stratigraphic analyses (florindo & sagnotti, 1995; borzi et al. 1998), carried out several metres above and below the volcanoclastic level, suggest that the investigated section may be placed at the c2r.1r polarity subchron of the geomagnetic polarity time scale (cande & kent, 1992), between the reunion and olduvai subchrons. this horizon is the only dated layer and one of the lowermost outcropping beds of the formation. the microfauna is abundant and contains: bulimina marginata and globorotalia inflata, only found in the lower part of the formation (piccardi, 1993; carboni & di bella, 1996), and bulimina elegans marginata, bulimina etnea, cassidulina carinata, valvulinerina bradyana, bolivina alata, uvigerina peregrina, globigerina cariacoensis, globigerinoides tenellus, globigerina calabra, plio-pleistocene stratigraphy ... 94 o. girotti & m. mancini f ig . 3 – s tr at ig ra ph ic a nd s ed im en to lo gi c re la tio ns hi ps a m on g pl io -p le is to ce ne m ar in e, tr an si tio na l a nd n on -m ar in e de po si ts a lo ng th e w es te rn m ar gi n of th e a m er in i m ts . l eg en d (s ym bo ls a re th e sa m e as in fi gu re s 4 an d 5) : 1 = tr an si tio n of fs ho re -s ho re fa ce s an dy s ilt s an d of fs ho re c la ys ; 2 = u pp er a nd lo w er s ho re fa ce s an ds ; 3 = p ro gr ad in g be ac h gr av el s; 4 = b io cl as tic c al ca re ni tic le ve l; 5 = c em en te d ca rb on at ic s an ds ; 6 = la go on al a nd d el ta -f ro nt s an dy c la ys ; 7 = t ra ve rt in es ; 8 = la cu st rin e an d flo od pl ai n cl ay s; 9 = f lu vi al c ro ss b ed de d gr av el s; 1 0 = f lu vi al c ro ss b ed de d sa nd s; 1 1 = li gn ite ; 12 = p yr oc la st ite s; 1 3 = m ol lu sc s sa m pl ed f or is ot op ic a na ly se s; 1 4 = s ec tio n in ve st ig at ed f or m ag ne to -s tr at ig ra ph ic a na ly se s; 1 5 = l ith op ha ga b or in gs ; 16 = m ar in e m ol lu sc s; 1 7 = b ra ck is h w at er m ol lu sc s; 1 8 = fr es h w at er m ol lu sc s; 1 9 = la nd s na ils ; 2 0 = v er te br at e re m ai ns . 95plio-pleistocene stratigraphy ... fig. 4 stratigraphic and sedimentologic relationships among marine, transitional and fluvial deposits in the central and southern part of the mvt. (1) = data after arias et al. (1980); (2) = arias et al. (1990); (3) = florindo & sagnotti (1995). globigerina aff. calida calida (carboni et al., 1993; di bella, 1994; carboni & di bella, 1994; mancini, 2000). it indicates the late gelasian-santernian age, in concomitance with the g. inflata-g. cariacoensis and the b. marginata-b elegans marginata zones. the macrofauna is characterised by corbula (vericorbula) gibba, natica tigrina, archimediella spirata, amyclina semistriata, sinodia brocchii, panopaea glycimeris, venus (ventricoloidaea) multilamella, pinna tetragona, cladocora coespitosa (piccardi, 1993; mancini, 2000). the analysis of the 87sr/86sr ratio carried out on several fragments of molluscs and hydrozoa (mancini, 2000) provided numerical values between 0.709068 and 0.709083 (tab. 1), which correspond to 1.5 and 1.7 ma. the chiani-tevere formation’s transitional and non-marine deposits extensively crop out along the eastern sector of the basin and are represented by the lithofacies assemblages described below. 1) fine clayey sands of brackish-water environment. these deposits are widespread along the western margin of the amerini-narni mts and correspond to the “facies salmastra” of the “asct” (am-brosetti et al., 1987). they are mainly composed of tabular stratified sands, which are laterally continuous westward to marine pelitic sands, and to the sandy fluvial deposits of the santa ma-ria di ciciliano formation (see below) to the east. a rich brackish water fauna has been found: cera-stoderma glaucum, bittium deshayesi, potamides tricinctus, thericium vulgatum, anadara darwini, trunculariopsis truncula conglobata, ammonia tepida. such deposits may be considered of the delta front environment (mancini, 2000). 2) travertines and c a l c a r e o u s silts. these n o n m a r i n e deposits crop out near the top of the formation and c o m m o n l y overlay the carbonatic substratum. they constitute tabular or lenticular bodies, few metres to several decametres thick (fig. 3), that are alternated with the brackish-water clayey sands. these lithofacies are rich in l a t e villafranchian fresh water molluscs and pulmonates like m e l a n o p s i s a f f i n i s , t h e o d o x u s g r o y a n u s , viviparus belluccii, emmericia umbra, neumayria priscil lae, bithynia tentaculata, b. leachi, micromelania (goniochilus) zitteli, prososthenia meneghiniana, valvata cristata. 3) cross bedded coarse grained sands alternated with clinostratified gravels. they are coarsening-up alternances of sands and gravels interpreted as parasequences, marked at the base by a flooding surface. each parasequence is generally 2 to 10 metres thick. the lower sands are cross bedded and of the shoreface environment; they vertically and landward pass to clinostratified, westward prograding gravels, overlain by planar bedded gravels of the beachface environment (massari & parea, 1988). rarely at the top, thin horizons of massive clay bearing brackish water molluscs have been found. the gravels are commonly well sorted, rich in sandy matrix and composed of well rounded calcareous, cherty and arenaceous cobbles and pebbles; in many cases the clasts are perforated by lithophaga. balanids, anomia ephippium, and ostrea spp. are the most frequent fossils. three, very thick (50 to 100 metres), gravelly-sandy bodies, composed of several vertically stacked parasequences, crop out in the orte-amelia area and east of mt soratte. each of them represents a set of parasequences that interfingers with the nearshore marine deposits to the west and with fluvial deposits to the east. they correspond to the civitella san paolo member, the torrita tiberina member and the vasanello member (figs. 2, 4). 4) cross bedded talus. these deposits crop out at the 96 o. girotti & m. mancini tab. 1 top of the formation in several sites along the western margin of the amerini-lucretili mts, where they ovelay the mesozoic substratum and are in part covered by nearshore sands. this lithofacies is composed of poorly sorted rudites, rich in sandy and clayey matrix, and subangular clasts. the depositional architecture is characterised by alternated channelized and tabular bodies, seaward interfingering with the marine and transitional sands. the total thickness ranges between 50 and 80 metres. such deposits are interpreted as fan-delta deposits (girotti & piccardi, 1994; mancini et al., 2001). 5) breccias and conglomerates with abundant sandyclayey matrix. they are poorly sorted rudites, with subangular clasts commonly borrowed by lithophaga. such rudites crop out in many sites of the amerini-lucretili mts western margin, directly onlapping the meso-cenozoic substratum, and laterally continuous seaward to shoreface sands. they are interpreted as transgressive beach deposits and cliff breccias (girotti & piccardi, 1994). 44..22..22.. tthhee ppooggggiioo mmiirrtteettoo ffoorrmmaattiioonn the poggio mirteto formation is heteropic to the chiani-tevere formation’s transitional deposits. it crops out in the south-eastern mvt along the western margin of the sabini mts and in the lower farfa river valley, areas historically known as valli sabine (tuccimei, 1889). the formation is up to 300 m thick and is composed of cross bedded, well sorted gravels, alternated with lenses of trough cross stratified silty sands. at a large scale the gravels and sands are arranged into multistorey-multilateral channel-bodies and are interpreted as fluvial deposits filling active channels. they are also interbedded with tabular bodies of massive or thinly laminated clays, the thickness of which ranges between 1 and 20 m. the clays, which commonly contain lignite, may be interpreted as fluvial-overbank or lacustrine deposits. such fine sediments are rich in fresh water molluscs like m. affinis, t. groyanus, viviparus ampullaceus, prososthenia etrusca, p. meneghiniana, negulus villafranchianus, e. umbra, m. (g.) zitteli, belgrandia sp. (ciangherotti et al., 1998; mancini, 2000; petronio et al., in press); in several cases sandy and clayey horizons that bear brackish water molluscs have been found (see logs 28 and 29 in fig. 4). vertebrate fossils are rarer: few remains of equus stenonis were discovered at filacciano (di bella, 1995) (fig. 4), bocchignano and castel s. pietro (tuccimei, 1891, 1893), and bones of anancus arvernensis and stephanorinus etruscus at castel s. pietro (tuccimei, 1891; petronio et al., in press). the malacologic and mammal content indicates the olivola-tasso faunal units (ciangherotti et al., 1998; petronio et al., in press). 44..22..33.. ssaannttaa mmaarriiaa ddii cciicciilliiaannoo ffoorrmmaattiioonn the santa maria di ciciliano formation (basilici, 1993) crops out very limitedly in the amelia-narni area, where the mvt basin is directly linked with the southwestern branch of the tiberino basin. this formation is composed of cross bedded silty sands, that laterally pass to the transitional sands of the chiani-tevere formation. more detailed data are dealt with in ambrosetti et al. (1995). 44..33.. tthhee mmiiddddllee eeaarrllyy pplleeiissttoocceennee ––eeaarrlliieesstt mmiiddddllee pplleeiissttoocceennee uunniittss the units of this period are in the chronological order: the giove formation, the mt cimino volcanic and volcano-sedimentary successions, the civita castellana unit. 44..33..11.. tthhee ggiioovvee ffoorrmmaattiioonn the giove formation limitedly crops out along the western margin of the amerini mts, where it corresponds to the travertini antichi (ambrosetti et al., 1987). it unconformably overlays the chiani-tevere formation and laterally rests on the meso-cenozoic substratum. its base is generally subplanar, although it is locally incised for a few tens of metres into the chiani-tevere formation (see logs 4, 5 and 9, in fig. 3). its planar top surface gently dips toward sw from 350 to 280 metres a.s.l., providing a terraced appearence to the formation. the maximum thickness is 60 m. the lower part of the giove formation, which is 25 m thick, is composed of cross bedded, calcareous or quartz-bearing sands and gravels, commonly cemented by calcium carbonate and interspersed with lenses of travertines. such mixed carbonatic and silicilcastic facies vertically pass to thick layers of well cemented travertines or, more rarely (see log 11, fig. 3), to planar bedded calcareous silts bearing v. belluccii, m. affinis, t. groyanus, carychium minimum, e. umbra, hauffenia minuta, bithynia spp., lymnaea spp. (piccardi, 1993). at bandita di giove (see log 8, fig. 3) several remains of late villafranchian mammals have been found (petronio et al., in press): stephanorhinus etruscus, leptobos sp., elephantidae indet.. the sedimentologic and paleontologic data indicate that the giove formation deposited firstly in a fluvial environment of relatively high energy, and successively in little lakes and swamps dominated by carbonatic production. the probable age is middle early pleistocene. 44..33..22.. tthhee mmtt cciimmiinnoo vvoollccaanniicc aanndd vvoollccaannoo--sseeddiimmeennttaarryy ssuucccceessssiioonnss these deposits crop out in the western bank of the tiber river near orte and viterbo. they form a wide tabular body with undulate base placed at 200 to 220 metres a.s.l., about 150 m above the modern tiber river’s plain. they are mostly riodacitic pyroclastic flow deposits, locally interlayered with lavas and travertines. the maximum thickness exceedes 100 m. the activity of the mt cimino complex ranges between 1.35 and 0.95 ma (borghetti et al., 1981; sollevanti, 1983), and the most widespread formation is the “peperino” formation auct., a 1.30 ma old latitic ignimbrite (barberi et al., 1994). 44..33..33.. tthhee cciivviittaa ccaasstteellllaannaa uunniitt the civita castellana unit partly corresponds to the paleotiber gravels (alvarez 1972; 1973). it is an unconformity-bounded unit, mostly composed of fluvial gravels (mancini, 2000) overlaying the chiani-tevere formation; its unconformable base may be correlated to the “cassia erosional phase” (bonadonna, 1968; alvarez, 1972). no direct stratigraphic relationships with the giove formation and the mt cimino volcanites are evident. in the northern mvt as far as orte, this unit forms the highest fluvial terraced deposits, which represents 97plio-pleistocene stratigraphy ... the i order terrace of the tiber river. its tread gently decreases southward from 280 to 170 metres a.s.l., while the thickness is up to 80 m. south of orte and west of the mt soratte the civita castellana unit fills a deep incision carved into the chiani-tevere formation (fig. 5); there, the base is at 50 metres a.s.l. and the thickness reaches 120 m. the most frequent lithofacies are tabular and cross bedded gravels (gh, gt and gp facies sensu miall (1996)), while trough cross-bedded sands are rarer. the gravels, in general well rounded and lamellar or discoidal in shape, are mainly of calcareous nature, although arenaceous and siliceous clasts are also present. frequent imbricate structures indicate prevalent southward-directed flows. the sandy matrix is abundant and rich in quartz and muscovite, although the calcite may locally dominate. in some cases the sandy lenses are rich in biotite and sanidine, probably supplied after the erosion of the mt cimino volcanites; furthermore volcanic clasts belonging to the peperino formation were also found (brandi et al., 1970). the textural data and the depositional architecture, which shows multistorey-multilateral channel bodies, suggest that the civita castellana unit was deposited in a braidplain environment. the gravels and sands are rarely interbedded with few metres thick, tabular or lenticular, pelitic beds of the floodplain environment (fig. 5), and with travertines, lignites and buried paleosols. the pelitic levels are rich in fresh water molluscs like valvata piscinalis, bithynia spp., planorbis planorbis and more rarely m. affinis and t. groyanus (logs 18 and 21, fig. 5), characteristic of the early pleistocene. in the lowermost part of the formation few remains of bison cfr. b. degiulii, which indicates the farneta and pirro faunal units (latest late villafranchian) (gliozzi et al., 1997; di stefano et al., 1998), have been discovered (log 18, fig. 5). this unit is late early pleistocene-earliest middle pleistocene in age, as it is overlain by the initial products of the vulsini and sabatini mts volcanic complexes, placed at around 600-500 ka (barberi et al., 1994). 44..44.. tthhee mmiiddddllee pplleeiissttoocceennee--hhoolloocceennee uunniittss a staircase of fluvial terraced deposits borders the modern course of the tiber river. the graffignano unit (middle pleistocene), rio fratta unit (late middle pleistocene), sipicciano unit (late pleistocene) and the recent alluvial deposits (holocene) (figs 1 and 2) represent the ii, iii and iv order terraces. their respective treads decrease southward: 1) from 210 to 65 m a.s.l.; 2) from 150 to 40 m a.s.l.; 3) from 100 to 35 m a.s.l.; 4) 98 o. girotti & m. mancini fig. 5 stratigraphic relationships among pleistocene fluvial deposits in the western part of the mvt. g.u. = graffignano unit; r.f.u. = rio fratta unit. from 70 to 25 m a.s.l. all the terraced deposits are mostly composed of cross bedded gravels and sands of the braided river environment; overbank deposits, paleosols and travertines are less frequent. the volcanic and volcano-sedimentary successions of the vulsini mts, vico and sabatini mts are widely exposed along the western bank of the tiber, and are mainly composed of pyroclastites interbedded with lavas and travertines. the stratigraphic relationships between some dated volcanic formations and the terraced deposits provide a fairly precise chronological framework for the fluvial units (mancini, 2000) (fig. 2). the graffignano unit, indeed, is more recent than the tufo giallo della via tiberina formation, dated 550 ± 10 ka (cioni et al., 1993), but it precedes the lake vico lava formation (perini et al., 1997), with ages between 305 ± 9 e 258 ± 2 ka. the rio fratta unit is younger than the above mentioned lavas, but it is older than the tufo rosso a scorie nere vicano formation, 151 ± 3 ka old (laurenzi & villa, 1987). finally, the sipicciano unit is younger than the tufo rosso a scorie nere vicano formation. 55.. ddiissccuussssiioonn 55..11.. iinnffeerreenncceess oonn sseeddiimmeennttaarryy ccyycclliicciittyy dduurriinngg tthhee pplliioocceennee aanndd tthhee eeaarrlliieesstt eeaarrllyy pplleeiissttoocceennee.. the sedimentary units of the mvt are separated into two main groups. 1) the first group spans from late zanclean to santernian and is characterised by the preponderance of marine deposits on transitional and continental ones. it represents a subsidence-dominated stratigraphic domain as the basin fill occurred during phases of subsidence (ambrosetti et al., 1987; barberi et al., 1994; bossio et al., 1998). 2) the second group, which ranges from middle early pleistocene to holocene, is solely characterized by terraced continental deposits interlayered with volcanic and volcano-sedimentary successions, and indicates an uplift-dominated stratigraphic domain. the subsidence-dominated domain is composed of the two main marine-non-marine cycles described above (fig. 2): 1) the first cycle (late zanclean-early gelasian), which started at about 3.6 ma, corresponds to the i and ii sedimentary cycles described in barberi et al. (1994) and to the p2 and p3 units of bossio et al. (1998), spanning 1.2-1.3 ma; 2) the second cycle corresponds to the iii cycle of barberi et al. (1994) and to the unit q1 (bossio et al., 1998). it spans 0.65 ma (bossio et al., 1998) and probably began at 2.1 ma. the first cycle is up to 300 m thick, while the second cycle is 350 m thick. the time spans and thicknesses therefore suggest that the two cycles may be considered as iii order depositional sequences (vail et al., 1990). the acquatraversa erosional phase, which separates the two cycles, spans 0.2-0.3 ma (bossio et al., 1998). the related unconformable surface indicates a sea level drop probably due to local infra-gelasian tectonism, that caused the emersion and the eastward tilting of i cycle’s units, in the northern mvt and near mt soratte. the acquatraversa erosional phase may also be correlated to the global eustatic sea level fall that occurred at 2.4 ma, when a major event of cooling was recorded (haq et al., 1987; bossio et al., 1998). similarly, the older fluvial and lacustrine deposits interfingered with marine sediments at camorena (barberi et al., 1994) and fabro (fig. 2) may be interpreted as a sedimentary response to the global cooling event that occurred at about 3.0 ma (channel et al., 1992; bossio et al., 1998). in the central mvt, the acquatraversa unconformable surface may be present in the subsoil, below the lowermost outcropping levels of the ii sedimentary cycle. it may be possible that the unconformity laterally passes to a conformable surface as well. the few subsurface data from the mvt do not verify any hypotheses, as the drilled sediments only belong to the ii cycle (di bella, 1994; carboni & di bella, 1994). nevertheless, subsurface data from the bordering sabatini mts area, at bracciano (carboni & palagi, 1998)), and from vallericca (arias et al., 1990; carboni et al., 1993) in the lower tiber valley indicate the stratigraphic continuity from late zanclaean to santernian (figs 6 and 7). 55..22.. rreellaattiioonnss bbeettwweeeenn mmaarriinnee aanndd nnoonn--mmaarriinnee ssuucccceess-ssiioonnss aanndd llaattee ggeellaassiiaann--ssaanntteerrnniiaann ppaalleeooggeeooggrraapphhyy the mvt ii sedimentary cycle is characterized by the heteropic relations between the chiani-tevere and poggio mirteto formations, east of mt soratte, and between the chiani-tevere and santa maria di ciciliano formations near amelia. the main architectural feature is represented by three large clastic wedges interfingering with the chiani-tevere formation’s shelf deposits. the clastic wedges are composed of the gravelly-sandy beach deposits of the civitella san paolo, torrita tiberina and vasanello members, and of their laterally continuous fluvial deposits (figs 2-4). each wedge indicates a phase of basinward progradation of fluvial, deltaic and coastal sediments alternated with transgressive phases, that are evidenced by the shelf deposits (fig. 4). the first prograding wedge may have developed at the gelasian-santernian transition; this is suggested by the correlation with those marine successions where the plio-pleistocene boundary is present or inferred, like lugnano, orte scalo, vallericca (carboni et al. 1993; carboni & di bella 1994; borzi et al. 1998) (fig. 4). the younger wedges are santernian in age. such progradational phases are also evidenced by other transitional and continental lithofacies: 1) the “fine clayey sands of brackish water environment” and the “travertines and calcareous silts” are related to the ii and iii progradational episodes (fig. 3); 2) the fan deltas occurring at fosso marutana, camartana, montasola, poggio catino and marcellina (fig. 7) are only related to the iii episode. the transgressive phases are evidenced not only by the rapid deepenig of facies, but also by the progressive onlap of the “breccias and conglomerates with abundant matrix” above the substratum, and by alignements of lithophaga borings and notches (fig. 7a). such depositional and erosive elements indicate shortterm sea level stands that punctuated the transgressions. the latter also caused an eastward shifting of the transitional facies, that reached the southwestern tiberino basin, as it is indicated by the discovery of brackish water molluscs (fig. 7a). the paleogeographic thresholds linking the mvt and the tiberino basin were located east of amelia at the san pellegrino pass and, perhaps, at the forello gorge near todi and at configni in sabina (fig. 7); they are considered as outlets of ancient fluvial systems (ambrosetti et al., 1987; girotti & piccardi, 1994; d’agostino et al., 2001). the rieti basin 99plio-pleistocene stratigraphy ... 100 o. girotti & m. mancini f ig . 6 c or re la tio n be tw ee n th e m v t a nd s ur ro un di ng s ba si ns ( da ta p ar tly m od ifi ed a fte r b on ad on na ( 19 68 ), b as ili ci ( 19 93 ), c ar bo ni e t a l. (1 99 3) , b ar be ri et a l. (1 99 5) , m ar ra e t a l. (1 99 5) , m ill i (1 99 7) , c ar bo ni & p al ag i ( 19 98 ), b er ga m in e t a l. (2 00 0) . 101plio-pleistocene stratigraphy ... f ig . 7 p al eo ge og ra ph y of t he l at iu m -u m br ia r eg io n du rin g th e la te g el as ia ns an te rn ia n: ( a ) tr an sg re ss iv e an d (b ) pr og ra da tio na l p ha se s. l eg en d: a ) ca rb on at ic a nd s ili ci cl as tic m es oce no zo ic s ub st ra tu m , b) a llu vi al a nd la cu st rin e de po si ts , c) p lio -q ua te rn ar y no nm ar in e de po si ts s ub je ct ed t o er os io n, d ) de lta ic a nd c oa st al d ep os its , e) e m er ge d m ar in e de po si ts , f) t ra ve rt in es , g) vo lc an ite s, h ) ve rt eb ra te r em ai ns , i) br ac ki sh -w at er m ol lu sc s, j ) ol ig oh al in e os tr ac od s, k ) li th op ha ga b or in gs ( w ith a lti tu de a .s .l. ), l ) fa nde lta a nd a llu vi al l-f an , m ) di re ct io n of a nc ie nt r iv er , n) di re ct io n of d el ta ic p ro gr ad at io n, o ) di re ct io n of p yr oc la st ic fl ow , p ) no rm al fa ul t, q) s tr ik esl ip fa ul t, r) m ai n cr at er . was probably affected indirectly by transgessions too, as it is evidenced by the presence of olighoaline ostracods in its northern sector, at fosso filundici and madonna della torricella (barberi et al., 1995; gliozzi & mazzini, 1998) (fig. 7a). it would be likely that the rieti basin was linked with the mvt basin through the terni sub-basin and/or the farfa valley (figs 1 and 7). on the other hand, the paleocoastline’s seaward shiftings, which occurred at the progradational phases, may be estimated at 12-15 km with respect to the western margin of mt peglia-lucretili mts ridge. such progradations are clearly evident in the vasanello-orteamelia and mt soratte-sabini mts areas in front of the deltaic systems of the paleo-nera and paleo-farfa rivers, that respectively drained the tiberino and rieti basins (fig. 7b). each progradation is related to periods of increased sedimentary supply coming down from the intramontane basins and their surrounding mountainous areas. this increment may be due to: 1) tectonics, that caused differential uplifts of the inner areas with respect to the subsiding marine basin. this twofold movement may have led to an increment of relief energy and consequent erosion in the emerged areas, and to an increase of accomodation space in the mvt basin. 2) climate changes, that may have been characterised by alternations between temperate and cold phases. in fact cooling episodes, if coupled with rainy periods and limited vegetation covers, may produce a great amount of eroded sediments and facil i tate their transport. furthermore, they are in general associated with eustatic sea level falls. in the chiani-tevere formation the effects of climatically-induced sea level falls have been detected only within the fan-delta deposits (iii progradational episode). the related base level drop is estimated at 70 m, although neither the tectonic nor the eustatic component have been fully distinguished (girotti & piccardi, 1994). as for the older progradational episodes, no erosive or depositional elements linked to sea level falls, like incisions or downward shifts of coastal facies, have been observed. in fact, it seems likely that the progradational and transgressive deposits progressively filled the basin in concomitance with the subsidence throughout the entire late gelasian-santernian. therefore, negative eustatic movements have not been recorded by erosive surfaces, as their rates were of the same magnitude or slower than the subsidence rate. on the other hand, the sedimentologic and erosive effects of periodical sea level rises and transgressions are clearly evident, as it is discussed above. although the triggering mechanism that control the alternating progradational and transgressive phases is not clear at all, each couple of main progradation-transgression may suggest a iv order cyclicity within the main iii order cycle. 55..33.. sseeddiimmeennttaarryy aanndd ppaalleeooggeeooggrraapphhiicc eevvoolluuttiioonn dduurriinngg tthhee mmiiddddllee eeaarrllyy pplleeiissttoocceennee--eeaarrll iieesstt mmiiddddllee pplleeiissttoocceennee.. the regional uplift started at the earliest-middle early pleistocene between 1.5 and 1.3 ma (ambrosetti et al., 1987; cavinato et al., 1994) and continued throughout the rest of quaternary, determining the alternance of erosional and depositional phases in concomitance with climate changes. each sedimentary unit deposited during this period represents a cycle of degradationaggradation. in particular, the late middle pleistoceneholocene terraced units were cyclically deposited every 100 ka, with a recurrence due to global climatic changes related to variations of the orbital eccentricity (imbrie, 1985). as for the middle early pleistocene-earliest middle pleistocene units, chronological data are less precise, so making uncertain the linkage between the alternances of depositional and erosional phases and the 100 ka spanning cyclicity. however, all the sedimentary units may indicate a iv order cyclicity, although the inferred time span of the civita castellana unit is about 600 ka, a bit longer than a iv order cycle. the most evident paleogeographic change after the early uplift was the south-westward shifting of the coastline for more than 30 km away from the mt peglialucretili mts ridge. in this way the roman area was reached, where coastal facies developed (fig. 8a). during the emilian, the developing juvenile tiber river caused at first the incision of the just emerged gelasiansanternian sediments, and then the deposition of the giove formation in concomitance with the mt cimino volcanic activity. the ancient river flowed parallel to the axis of the paglia-tevere graben west of mt soratte (alvarez, 1972; 1973). the ancient tiber mouth may be represented by the transitional deposits of the “sabbie gialle di monte mario” (bonadonna, 1968); the latter crops out at monte mario in rome, covers santernian sediments and bears late villafranchian molluscs and vertebrates (girotti, 1972; caloi & palombo, 1988; petronio et al., in press) (figs. 6 and 8a). the tiber’s upper catchment was mainly affected by erosion, although local sedimentation persisted with the deposition of the lacustrine pelites of the “case strinati-madonna della torricella unit” in the northern rieti basin (cavinato et al., 2000), and of the travertines of the “acquasparta formation” in the southwestern tiberino basin (basilici, 1992) (figs. 6 and 8a). during the sicilian-earliest middle pleistocene, the coastline continued to migrate westward reaching the ponte galeria area, where fluvial-deltaic sediments were deposited (conato et al., 1980; milli, 1997; karner et al., 2000) (figs 6 and 8b). in the mvt the ongoing uplift caused a renewal of the fluvial incision the “cassia erosional phase” auct. – which may be estimated at more than 100 m (mancini, 2000). such an incision cuts the chiani-tevere and giove formations and caused the “cannibalization” of the oldest tiber river’s deposits. this downcutting also affected the mesocenozoic substratum at the forello and stifone gorges (fig. 8b), where the activity of local antiapennic-trending faults may have caused captures and deviations of the tiber and nera river courses (cattuto et al., 1997) (figs. 8a-b). the erosional phase was followed by the aggrading civita castellana unit. this unit may be correlated with the fluvial deposits outcropping at marcigliana in the lower tiber valley (basili, 1996), and with those filling the small ongoing “paleotiber graben” in the northern roman area (karner et al., 2001) (fig. 8 b). the correlation is suggested by both the lateral continuity between fluvial units, detected below the middle pleistocene sabatini mts volcanites (funiciello et al., 1994), and by biochronological data after the discove102 o. girotti & m. mancini 103plio-pleistocene stratigraphy ... f ig . 8 p al eo ge og ra ph y of th e la tiu m -u m br ia r eg io n du rin g: ( a ) th e e m ili an ; ( b ) th e s ic ili an -e ar lie st m id dl e p le is to ce ne . ries of vertebrates belonging to the farneta-pirro faunal units (late early pleistocene) in several sites as rio fratta, capena, redicicoli 1 (di stefano et al., 1998; petronio et al., in press). 66.. ccoonncclluussiioonnss the stratigraphic data and the consequent interpretation of the paleogeographic evolution of the mvt and surrounding basins delineate a late pliocene-earliest early pleistocene subsidence-dominated tectono-sedimentary phase and a middle early pleistocene-holocene uplift-dominated phase. the first phase provides direct chronostratigraphic elements, based on biostratigraphic, biochronologic, physical-, isotopicand magneto-stratigraphic analyses and observations which are of great relevance in correlating the interfingered marine, transitional and non-marine successions, widely outcropping at the borders of the mvt, tiberino and rieti basins. for the second phase, the new biochronologic data, the relations between fluvial and volcanic deposits and the inferred regional paleogeography provide indirect tools for the correlation between the fully non-marine mvt basin and the roman area, characterised by marine, transitional and fluvial successions, in particular for the emilian-early middle pleistocene interval. nnootteess:: (1) recent and exhaustive re-examinations of the ancient paleontologic findings in the valli sabine are published in kotsakis (1988), esu & girotti (1991), gliozzi et al. (1997), ciangherotti et al. (1998), petronio et al. (in press). (2) pareto (1865) introduced the villafranchian stage and attributed to it those non-marine sediments that were deposited above the pliocene marine successions as a consequence of a general withdrawal of the sea. he applied the term villafranchian to all the non-marine deposits of northand central-italy and considered it as quaternary in age. hürzeler (1967) recognized a pliocene age for the vertebrates of villafranca d’asti (the type locality of the stage) and azzaroli (1977) subdivided the villafranchian into early (middle pliocene), middle (late pliocene) and late (early pleistocene). most of the non-marine sediments ranging from middle pliocene to early pleistocene are actually mapped as villafranchian on the geologic map of italy. the succession of the type locality is middle pliocene. in recent times some doubt was expressed about the validity of the villafranchian as chronostratigraphic unit (carraro, 1996), whereas gliozzi et al. (1997) introduced and defined the villafranchian in the biochronological scale of the mammal ages. nevertheless, the pliopleistocene non-marine successions are so widespread in italy that, in our opinion, they need to be classified in an independent chronostratigraphical scale; in fact, an attribution to the marine one is rarely possible. therefore, we think that, in order to classify the huge amount of non-marine successions outcropping in italy, the villafranchian should not be abandoned and a formalization is to be hoped for. the lower boundaries of early and late villafranchian, at least, may be defined on sections at villafranca d’asti and in the upper valdarno respectively, where continuous sedimentation occured and litostratigraphy as well as palaeontological and magnetostratigraphical data are available. aacckknnoowwlleeddggeemmeennttss we would like to thank prof. mario barbieri for the isotopic analyses and dott. carlo bosi for the useful comments that have improved our manuscript. this research was supported by murst (60%) and by cnr igag. rreeffeerreenncceess alvarez w. (1972) the treia valley north of rome: volcanic stratigraphy, topographic evolution, and geological influences on human settlement. geol. romana, 1111, 153-176. alvarez w. (1973) ancient course of the tiber river near rome: an introduction to the middle pleistocene volcanic stratigraphy of central italy. geol. soc. am. bull., 8844, 749-758. ambrosetti p., basilici g., capasso barbato l., carboni m.g., di stefano g., esu d., gliozzi e., petronio c., sardella r., & squazzini e. (1995) i l pleistocene inferiore nel ramo sud-occidentale del bacino tiberino (umbria): aspetti litostratigrafici e biostratigrafici. il quaternario, 88, 19-36. ambrosetti p., carboni m.g., conti m.a., esu d., girotti o., la monica g.b., landini b., & parisi g. (1987) il pliocene ed il pleistocene inferiore del bacino del fiume tevere nell’umbria meridionale. geogr. fis. dinam. quat., 1100,, 10-33. arias c., azzaroli a., bigazzi g., & bonadonna f.p. (1980) magnetostratigraphy and pliocenepleistocene boundary in italy. quaternary res., 1133, 65-74. arias c., bigazzi g., bonadonna f.p., iaccarino s., urban b., dal molin m., dal monte l., & martolini m. (1990) valle ricca late neogene stratigraphy (lazio region, central italy). paleobiol. cont., 1177, 61-80. azzaroli a. (1977) the villafranchian stage in italy and the plio-pleistocene boundary. giorn.geol., s.2, 4411, 61-79. barberi f., buonasorte g., cioni r., fiordelisi a., foresi l., iaccarino s., laurenzi m.a., sbrana a., vernia l., & villa i.m. (1994) plio-pleistocene geological evolution of the geothermal area of tuscany and latium. mem. descr. carta geol. it., 4499, 77-134. barberi r., cavinato g.p., gliozzi e., & mazzini i. (1995) late pliocene-early pleistocene palaeoenvironmental evolution of the rieti basin (central apennines). il quaternario, 88, 515-534. barbieri m., castorina f., colalongo m.l. pasini g., & vaiani c. (1998) worldwide correlation of the pliocene/pleistocene gssp at vrica (southern italy) confirmed by strontium isotope stratigraphy. newsl. stratigr., 3366, 177-187. basil i r. (1996) i l quaternario della zona di monterotondo (roma). il quaternario, 99, 167-178. basilici g. (1993) il bacino continentale tiberino: analisi sedimentologica e stratigrafica. phd. diss., v cycle, università di bologna, 323 pp., bologna. bergamin l., carboni m.g., di bella l., marra f., & palagi i. (2000) stratigraphical and paleoenvironmental features of the pleistocene sediments of monte mario (rome). eclogae geol. helv., 9933, 265-275. bonadonna f.p. (1968) studi sul pliocene del lazio. la biostratigrafia di monte mario e la "fauna malacologica mariana" di cerulli irelli. mem. soc. geol. it., 77, 261-321. borghetti g., sbrana a., & sollevanti f. (1981) vulcano-tettonica dell’area dei monti cimini e rapporti cronologici tra vulcanismo cimino e vicano. rend. soc. geol. it., 44, 253-254. 104 o. girotti & m. mancini borzi m., carboni m.g., cilento g., di bella l., florindo f., girotti o., piccardi e., & sagnotti l. (1998) bioand magneto-stratigraphy in the tiber valley revised. quatern. int., 4477//4488, 65-72. bossio a., costantini a., foresi l.m., lazzarotto a., mazzanti r., mazzei r., pascucci v., salvatorini g., sandrelli f., & terzuoli a. (1998) neogenequaternary sedimentary evolution in the western side of the northern apennines (italy). mem. soc. geol. it., 5522, 513-525. brandi g.p., cerrina feroni a., decandia f.a., giannelli l., monteforti b., & salvatorini g. (1970) il pliocene del bacino del tevere fra celleno (terni) e civita castellana (viterbo). stratigrafia ed evoluzione tettonica. atti soc. toscana sc. nat., 7777, 308-326. buonasorte g., carboni m.g., & conti m.a. (1991) il substrato plio-pleistocenico delle vulcaniti sabatine: considerazioni stratigrafiche e paleoambientali. boll. soc. geol. it., 111100, 35-40. caloi l. & palombo m.r. (1988) le mammalofaune plio-pleistoceniche dell’area laziale, problemi biostratigrafici e implicazioni paleoclimatiche. mem. soc. geol. it., 3355, 99-126. cande s.c. & kent d.v. (1992) a new geomagnetic polarity time scale for the late cretaceous and cenozoic. j. geophys. res., 9977, 13917-13951. carboni m.g. & di bella l. (1994) la successione pleistocenica del sottosuolo di orte. boll. soc. geol. it., 111155, 85-94. carboni m.g. & di bella l. (1996) the pleistocene section of podere palombaro (umbria). geol. romana, 3322, 97-108. carboni m.g., di bella l., & girotti o. (1993) nuovi dati sul pleistocene di valle ricca (monterotondo, roma). il quaternario, 66, 38-48. carboni m.g. & palagi i. (1998) biostratigrafia del sottosuolo plio-pleistocenico a sud del lago di bracciano: il sondaggio sabatini 9. il quaternario, 1111, 107-114. carraro f. (1996) revisione del villafranchiano nell’area tipo di villafranca d’asti. il quaternario, 99, 5-120. cattuto c., cencetti c., & gregori l. (1997) un vistoso esempio di controllo strutturale e di morfogenesi fluviale tra todi e baschi (fg. 130 carta d’italia). il quaternario, 1100, 181-190. cavinato g.p., cosentino d., de rita d., funiciello r., & parotto m. (1994) tectono-sedimentary evolution of intrapenninic basins and correlation with the volcano-tectonic activity in central italy. mem. descr. carta geol. it., 4499, 63-76. cavinato g.p., gliozzi e., & mazzini i. (2000) two lacustrine episodes during the late plioceneholocene evolution of the rieti basin (central apennines, italy). in: lake basins through space and time (eds. gierlowski-kordesch e.h. and kelts k.r.) aapg studies in geology 4466, 527-534. channell j.e.t., di stefano e., & sprovieri r. (1992) calcareous plankton biostratigraphy, magnetostratigraphy and paleoclimatic history of the pliopleistocene monte s. nicola section (southern sicily). boll. soc. paleont. it., 3311, 351-382. ciangherotti a.d., esu d., & girotti o. (1998) review of the history of the late neogene-early quaternary non-marine molluscs of italy. meded. ned. inst. toegepaste geowetensch. tno, 6600, 491-498, amsterdam. cioni r., laurenzi m., sbrana a., & villa i.m. (1993) 40ar/39ar chronostratigraphy of the initial activity in the sabatini volcanic complex. boll. soc. geol. it., 111122, 251-263. cita m.b. (1975) planktonic foraminiferal biozonation of the mediterranean pliocene deep sea record. a revision. riv. it. paleont. stratigr., 8811, 527-544. cita m.b. & castradori d. (1995) rapporto sul workshop “marine sections from the gulf of taranto (southern italy) usable as a potential stratotypes for the gssp of the lower, middle and upper pleistocene” (29 settembre-4 ottobre 1994). boll. soc. geol. it., 111144, 319-336. clerici e. (1895) presentazione di fossili della regione fra monti corniolani e lucani, e digressione sulla pretesa epoca villafranchiana di detta regione. boll. soc. geol. it., 1144, 315-320. clerici e. (1929) osservazioni geo-mineralogiche sulle sabbie del soratte. boll. soc. geol. it., 4488, 317-321. conato v., esu d., malatesta a., & zarlenga f. (1980) new data on pleistocene of rome. quaternaria, 2222, 131-176. conti m.a. & girotti o. (1977) il villafranchiano nel “lago tiberino”, ramo sud-occidentale: schema stratigrafico e tettonico. geol. romana, 1166,, 67-80. d’agostino n., jackson j.a., dramis f., & funiciello r. (2001) interactions between upwelling, drainage evolution and active normal faulting: an example from the central apennines (italy). geophys. j. int., 114477, 475-497. di bella l. (1995) le associazioni a foraminiferi del plio-pleistocene della media e bassa valle del tevere. stratigrafia e paleoecologia. phd diss., vii cycle, università di modena, 315 pp, modena. di stefano g., petronio c., & sardella r. (1998) biochronology of the pleistocene mammal faunas from rome urban area. il quaternario, 11, 191-199. florindo f., & sagnotti l. (1995) paleomagnetism and rock magnetism in the upper pliocene valle ricca (rome, italy) section. j. geophys. int., 112233, 340-354. funiciello r., giuliani r., marra f., & salvi s. (1994) the influence of volcanism and tectonics on plioquaternary regional landforms in the southeastern sabatinian area (central italy). mem. descr. carta geol. it., 4499, 323-332. funiciello r., parotto m, & praturlon a. (1981) carta tettonica d’italia. cnr pfg, publ. 269, rome. girotti o. (1967) considerazioni geologiche sul pliopleistocene del bacino inferiore della nera. atti acc. gioenia sc. nat., 1188, 27-32. girotti o. (1972) correlabilità, mediante molluschi di acqua dolce, del calabriano di monte mario (roma) col villafranchiano superiore. geol. romana, 1111, 229-235. girotti o. & piccardi e. (1994) linee di riva del pleistocene inferiore sul versante sinistro della media valle del fiume tevere. il quaternario, 77, 525-536. gliozzi e., abbazzi l., argenti p., azzaroli a., caloi l., capasso barbato l., di stefano g., esu d., ficcarelli g., girotti o., kotsakis t., masini f., mazza p., mezzabotta c., palombo m.r., petronio c., rook l., sala b., sardella r., zanalda e., & 105plio-pleistocene stratigraphy ... torre d. (1997) biochronology of selected mammals, molluscs and ostracods from middle pliocene to the late pleistocene in italy. the state of the art. riv. it. paleont. strat., 110033, 369-388. gliozzi e. & mazzini i. (1998) paleoenvironmental analysis of early pleistocene brackish marshes in the rieti and tiberino intrapenninic basins (latium and umbria, italy) using ostracods (crustacea). paleogeog., paleoclimat., paleoecol., 114400, 325-333. haq b.u., hardenbol j., & vail p.r. (1987) chronology of the fluctuating sea levels since the triassic. science, 223355, 1156-1167. hürzeler j. (1967) nouvelles découvertes de mammifères dans les sédiments fluvio-lacustres de villafranca d’asti. colloques internat. c.n.r.s. 116633 “problèmes actuels de paléontologie (évolution del vertébrés)”. 633-636, paris, 6-11 juin 1966. imbrie j. (1985) a theoretical framework for the pleistocene ice ages. j. geol. soc. london, 114422,, 417-432. ippolito f. (1947) contributo alla conoscenza della malacofauna delle ligniti di colle dell’oro, presso terni. rend. acc. sc. fis. matemat. soc. scienze, lettere ed arti, 1155, 1-10. karner d.b., marra f., florindo f., & boschi e. (2001) pulsed uplift estimated from terrace elevations in the coast of rome: evidence for a new phase of volcanic activity? earth planet. sci. lett., 118888, 135-148. kotsakis t. (1988) biostratigraphy of plio-pleistocene arvicolids of italy. modern geology, 13, 163-175. laurenzi m.a. & villa i.m. (1987) 40ar/39ar chronostratigraphy of vico ignimbrites. per. mineral., 56, 285293. malatesta a. (1974) malacofauna pliocenica umbra. mem. descr. carta geol. d’it., 1133, 464. mancini m. (2000) stratigrafia dei depositi fluviali e costieri pleistocenici nella media valle del tevere. ph.d. diss., xii cycle, università di roma “la sapienza”, 209 pp., rome. mancini m., girotti o., & cavinato g.p. (2001) carta geologica della media valle del tevere. un. roma “la sapienza” dip. sc. terra, cnr csqea, autorità di bacino del fiume tevere, rome. marra f., carboni m.g., di bella l., faccenna c., funiciello r., & rosa c. (1995) il substrato pliopleistocenico nell’area romana. boll. soc. geol. it., 111144,, 195-214. marra f., rosa c., de rita d., & funiciello r. (1998) stratigraphic and tectonic features of the middle pleistocene sedimentary and volcanic deposits in the area of rome (italy). quatern. int., 4477--4488, 51-63. massari f. & parea g.c. (1988) progradational gravel beach sequences in a moderateto high-energy, microtidal environment. sedimentology, 3355, 881-913. mattias p.p. & ventriglia u. (1970) la regione vulcanica dei monti sabatini e cimini. mem. soc. geol. it., 99, 331-384. miall a.d. (1996) the geology of fluvial deposits: sedimentary facies, basin analysis and petroleum geology. springer verlag, berlin, 528 pp. miall a.d. (2000) principles of sedimentary basin analysis. 3rd, updated and enlarged edition. springer verlag, berlin, 616 pp. milli s. (1997) depositional setting and high-frequency sequence stratigraphy of the middle-upper pleistocene to holocene deposits of the roman basin. geol. romana, 3333, 99-136. nappi g., renzulli a., santi p., & gillot p.y. (1995) geological evolution and geochronology of the vulsini volcanic district (central italy). boll. soc. geol. it., 111144, 599-613. nicoletti m. (1969) datazioni argon-potassio di alcune vulcaniti delle regioni vulcaniche cimina e vicana. per. mineral., 3388, 1-20. pareto m. (1865) note sur la subdivision que l’on pourrait établir dans les terrains de l’apennin septentrional. bull. soc. géol. fr., s.2, 2222, 210-277. perini g., conticelli s., & francalanci l. (1997) inferences of the volcanic history of the vico volcano, roman magmatic province, central italy: stratigraphical, petrographic and geochemical data. mineral. petrogr. acta, 4400, 67-93. petronio c., argenti p., caloi l., esu d., girotti o., & sardella r. (in press) updating villafranchian mollusc and mammal faunas of umbria and latium (central italy). geol. romana, 3366. piccardi e. (1993) il plio-pleistocene in sinistra del tevere dal lago di corbara a magliano in sabina. phd. diss., v cycle, università degli studi di roma "la sapienza", 210 pp, rome. principi p. (1922) alcune osservazioni sul quaternario dell’umbria centrale. atti dell’acc. naz. dei lincei, 3311, 56-59. salvador a. (1994) international stratigraphic guide, second edition. international union of geological sciences, trondeheim, and geological society of america, boulder, 214 pp. sollevanti f. (1983) geologic, volcanologic and tectonic setting of the vico-cimino area, italy. j. volcanol geotherm. res., 1177, 203-217. sprovieri r. (1993) pliocene-early pleistocene astronomically forced planktonic foraminifera abundance fluctuations and chronology of mediterranean plankton bio-events. riv. it. paleont. strat., 9999, 371-414. terrenzi g. (1886) il pliocene nei dintorni di narni. boll. soc. geol. it., 55, 321-336. tuccimei g. (1889) il villafranchiano nelle valli sabine e i suoi fossili caratteristici. boll. soc. geol. it., 88, 95-132. tuccimei g. (1891) alcuni mammiferi fossili delle provincie umbra e romana. mem. pontif. acc. nuovi lincei, 77, 89-152. tuccimei g. (1893) resti di arvicola nel pliocene lacustre della sabina. mem. pontif. acc. nuovi lincei, 99, 1-13. tuccimei g. (1895) il villafranchiano e l’astiano nella valle tra i cornicolani e i lucani. atti acc. pontif. naz. lincei, 1133, 1-30. vail p.r., audemard f., bowman s.a., eisner p.n., & perez-cruz g. (1990) the stratigraphic signatures of tectonics, eustasy and sedimentation. in “cycles and events in stratigraphy” ed. einsele g., ricken w., & seilacher a., 617-659, elsevier, amsterdam. 106 o. girotti & m. mancini imp. muto & ggeeoommoorrpphhoollooggyy,, tteeccttoonniiccss aanndd sseeddiimmeennttoollooggyy ooff llaattee qquuaatteerrnnaarryy ffaannss bbeettwweeeenn gguuaarrddiiaa ppiieemmoonntteessee aanndd ppaaoollaa ((ttyyrrrrhheenniiaann ccooaasstt ooff ccaallaabbrriiaa,, ssoouutthheerrnn iittaallyy)) ffrraanncceessccoo mmuuttoo,, ggaaeettaannoo rroobbuusstteellllii ((**)),, ffaabbiioo ssccaarrcciigglliiaa,, vviinncceennzzoo ssppiinnaa && ssaallvvaattoorree ccrriitteellllii dipartimento di scienze della terra, università della calabria. (*) corresponding author, e-mail robustelli@unical.it abstract an integrated geomorphological, preliminary structural and sedimentological study has been carried out, in order to investigate the role of tectonic and geological setting on the late quaternary evolution of the landscape. the study area represents a portion of the onshore belt located on the eastern margin of the tyrrhenian extensional basin (coastal range). this sector of calabria consists of a thrust-pile (calabrian arc auct.), including both metamorphic and non-metamorphic rocks. structural analysis evidences four sets of major fault systems; they affect a monocline consisting of a complex folded morphostructure. the nnw-sse trending faults are dip-slip and oblique extensional faults, as suggested by superimposition of the striations. the relative chronology suggests that the youngest kinematics is represented by right-lateral normal faults. the ne-trending faults are oblique normal and dip-slip faults; the latter are compatible with the kinematics of the right-lateral nnw trend. geomorphological analysis allows three generations of alluvial-fans to be distinguished; furthermore, valley-side perched alluvial terraces occur in the lower reaches of the valley descending from the coastal range. the three generations of alluvial fans are telescopically arranged, and the apexes of the piedmont fans (1st generation) are entrenched in respect to perched alluvial terraces. the fans at issue derived from steep catchments, developed as consequent and/or subsequent river valleys debouching from the mountain front. the piedmont zone comprises the 1st generation of alluvial-fans, bordered to the west by a nearly n-s striking scarp commonly reaching up to 80 m in height to the south. the present-day coastal plain comprises the 2nd generation of alluvial-fans which lie upon and interfinger with late pleistocene coastal and eolian deposits; the latter sail the foot-zone scarp of piedmont fans. a tephra layer has been recognised within eolian deposits. on the basis of preliminary structural and morphotectonic data, the last tectonic phase responsible for the latest landscape fragmentation, was probably characterised by a nw-se trending extension direction. moreover, morphometric measurements and pre-existing offshore data support the hypothesis that, since middle-late? pleistocene time, weak tectonic subsidence, coupled with marine base level rise, constitute the main mechanisms promoting the creation of the accommodation space for fan aggradation. the quaternary alluvium is characterised by a variety of coarse-grained facies coming to be regarded as alluvial-fan facies. in particular, detailed facies analysis revealed the presence of 4 facies associations, mainly represented by debris flow, debris avalanche deposits and sheetflood facies; facies associations also allow different alluvial fan evolutionary stages to be outlined. in addition, the lithology of the bedrock outcropping within fan catchments, have been also identified as the main factors which played important roles in controlling the different depositional processes and consequently facies assemblages. riassunto è stato condotto uno studio integrato di carattere geomorfologico, strutturale e sedimentologico al fine di investigare il ruolo svolto dalla tettonica e dall’assetto geologico sull’evoluzione tardo-quaternaria di una porzione della catena costiera. essa rappresenta il margine orientale del bacino estensionale tirrenico. questo settore della calabria consiste in una struttura a falde (arco calabro auct.), comprendente rocce sia metamorfiche sia non metamorfiche. l’analisi strutturale evidenzia quattro principali sistemi di faglie, che interessano una complessa morfostruttura. le faglie nnw-sse presentano cinematismi di tipo diretto ed estensionali obliqui, come suggerisce la sovrapposizione delle strie sui piani di faglia. la loro cronologia relativa mostra che la cinematica più recente è rappresentata dalle faglie normali a componente destra. le faglie ne-sw risultano normal trascorrenti e dirette; le ultime sono compatibili con la cinematica dei sistemi nnw-sse a componente destra. l’analisi geomorfologica permette di distinguere tre generazioni di conoidi alluvionali. inoltre, terrazzi fluviali sospesi si rinvengono incastrati morfologicamente nelle porzioni più basse e più distali (verso la costa) delle valli che dissecano la catena costiera. le due generazioni di conoidi sono incastrate a cannocchiale l’una nell’altra, e gli apici dei quelle di prima generazione si incastrano tra i lembi dei terrazzi sospesi. i bacini di drenaggio che alimentano i conoidi, derivanti da un sistema di corsi d’acqua conseguenti e/o susseguenti che sboccano dal fronte montuoso, sono piuttosto acclivi. la zona pedemontana comprende le conoidi di prima generazione ed è limitata ad ovest da una scarpata a direzione circa n-s che verso sud raggiunge anche gli 80 m di altezza. la piana costiera attuale comprende le conoidi di seconda generazione, che si sovrappongono e si interdigitano con i depositi costieri ed eolici tardo-pleistocenici; questi ultimi, nei quali è intercalato un livello vulcanoclastico, suturano la scarpata che limita, verso mare, i conoidi della zona pedemontana. sulla base di dati strutturali preliminari e morfotettonici è stato possibile individuare l’ultima fase tettonica responsabile della frammentazione del paesaggio nell’area indagata, caratterizzata probabilmente da una direzione di estensione nw-se. inoltre, la misura di alcuni parametri morfometrici e la rilettura di dati sismici relativi alla piattaforma continentale sommersa consentono di ipotizzare che, a partire dal pleistocene medio-superiore?, una debole subsidenza, accompagnata dalla risalita eustatica del livello del mare, doveva costituire il principale meccanismo per la creazione dello spazio di accomodamento utile alla crescita dei conoidi. i depositi quaternari affioranti nell’area sono rappresentativi di sistemi deposizionali di conoide alluvionale. in particolare sono state distinte 4 associazioni di facies, tra cui le principali sono rappresentate da conglomerati massivi (debris-flow e debris-avalanche) e da depositi di lame di piena (sheetflood); le associazioni di facies hanno consentito, inoltre, di definire differenti stadi evolutivi nella crescita dei conoidi alluvionali. inoltre, la litologia del substrato, sottesa ai vari bacini idrografici, rappresenta un’ulteriore fattore di controllo nello sviluppo dei differenti processi deposizionali. key words: geomorphology, tectonics, sedimentology, coastal alluvial-fans, tyrrhenian coast, calabria, southern italy parole chiave: geomorfologia, tettonica, sedimentologia, conoidi alluvionali costieri, costa tirrenica, calabria, italia meridionale. il quaternario italian journal of quaternary sciences 1166(2), 2003, 217-229 218 f. muto et al. 11.. iinnttrroodduuccttiioonn the study area is located along the western coast of calabria, on the eastern margin of the tyrrhenian basin (fig. 1a). this basin developed since late tortonian times (kastens et al., 1990) as back-arc basin of the southern apennine thrust and fold belts (patacca & scandone, 1989; patacca et al., 1990). since middlelate pliocene the tyrrhenian basin was affected by extensional tectonics, responsible for the formation of perityrrhenian depressions, such as the paola slope basin (barone et al., 1982; fabbri et al., 1981; rehault et al., 1987), and the uplift of the coastal range (sorriso-valvo & sylvester, 1993). the plio-quaternary evolution of the paola slope basin has been investigated in detail by analysis of offshore data (barone et al., 1982; gallignani, 1982; argnani & trincardi, 1988; 1993; chiocci et al., 1989; chiocci, 1995; chiocci & orlando 1995). conversely, few studies have been carried out on the reconstruction of the onshore basin margin, due to the dearth of geomorphological and stratigraphical data. robustelli et al. (2002) represent the first attempt to reconstruct a middle-late pleistocene geomorphological evolution. furthermore, the only available literature on the geomorphological features of the coastal range has focused on the assessment and estimation of uplift rates (verstappen 1977; carobene et al., 1986; carobene, 1987; carobene & ferrini, 1993; bordoni & valensise, 1998) and of hillslope degradation processes (sorrisovalvo & sylvester, 1993; sorriso-valvo et al., 1998). quaternary continental and marine deposits associated with erosional landforms coexist in the study area. an integrated structural, stratigraphical and geomorphological study has been carried out in order to reconstruct the late quaternary evolution, and to state the role of tectonic and geological setting which, coupled with eustacy (robustelli et al., 2002), influenced alluvial fan development. these authors have proposed a model of evolution, according to which quaternary fan development was mainly related to phases of climate amelioration following glacial periods, but just before interglacial highstands were approached; progressively increasing moisture and temperatures allowed bio-chemical rock degradation, and consequent increased runoff favoured removal of slope-waste materials, which promoted alluvial-fan development, mainly by gravity processes. sea level highstand induced coastal erosion of fan toes, resulting in foreshortened longitudinal profiles and fan dissection (e.g. harvey et al., 1999); sediment input was probably channelled away from subaerial basins, enabling progradation over the shelf. the subsequent lowering of sea level promoted fan-trenches lowering and the progressive emergence and dissection of the paola basin shelf; products of slope degradation during glacial periods, probably, had to be conveyed from the mountain catchments to fill paleovalleys, detected by means of seismic profiles analysis (chiocci et alii, 1989; chiocci, 1995; chiocci & orlando, 1995), thus disabling fan-development. fig. 1 a northwestern sector of the calabrian arc (after tortorici et. al., 1982, modified) with the location of the study area; b geological sketch map of the study area. a settore nord-occidentale dell’arco calabro, (da tortorici et al., 1982, modificato) ed ubicazione dell’area di studio; b carta geologica dell’area di studio. 219geomorphology, tectonics and sedimentology... 22.. ggeeoollooggiiccaall sseettttiinngg the northwestern sector of the calabrian chain consists of a flat-lying nappe (calabrian arc auct.) which constitutes the morphostructural height of the coastal range (fig. 1a); in particular it consists of highgrade metamorphic rocks of the polia copanello unit, tectonically overlapping low-grade metamorphic rocks of the castagna unit and bagni formation (amodio morelli et al., 1976; dietrich, 1976; colonna & compagnoni, 1982); these units overlapped the ophiolitic complex (liguride complex, ogniben, 1973; messina et al., 1981, boullin, 1984; knott, 1987; dewey et al., 1989), and the carbonatic units (amodio morelli et al., 1976). thrust-sheets were cut by four sets of major faults, the relative ages of which have been determined by sylvester et al. (1987). in the study area, a miocene sedimentary sequence rests on the crystalline-metamorphic basement of the coastal range; it constitutes the sedimentary infilling of the correlative amantea basin, dated to upper tortonian by di nocera et al. (1974), outcropping to the south (mattei et al., 2002; muto & perri, 2002). in the study area, the miocene deposits consist (fig. 1b) of two unconformable sequences. the first one is characterised by conglomerates and sandstones, underlying the 2nd sequence constituted by yellow calcarenites and grey-blue clays; the latter have been recognised in boreholes along the coastline. this succession exhibits a general monoclinalic attitude, with a growing dip towards west. late quaternary continental deposits rest unconformably on the basement and the miocene sedimentary sequence. the coastal range is a horst which started to uplift since plio-pleistocene time (tortorici, 1982a; 1982b), and produced the progressive isolation of the crati valley from the tyrrhenian sea, accompanied by the formation of the paola basin. this basin extends along the n-s direction, on the west side of the study area, from the sangineto zone to the capo vaticano zone. the paola basin has an architecture controlled by extensional tectonic phases and contractional events (canu & trincardi, 1989); moreover, it exhibits a depocenter localised immediately behind the continental slope, and is characterised by high depositional gradients (fabbri et al., 1981; gallignani 1982; barone et al., 1982; finetti & del ben, 1986; chiocci, 1995). 33.. pprreelliimmiinnaarryy ssttrruuccttuurraall aannaallyyssiiss the northwestern sector of the tyrrhenian margin is characterised by a complex structural arrangement which is limited by the falconara fault zone (turco et al., 1990) to the south and the guardia piemontese morphostructure to the north. the oldest structures are represented by thrust faults and by two generations of folds, with axes oriented roughly from nnw-sse to nne-ssw. these folds, which involve all the tortonian deposits, are asymmetric and verging to the east. these structures are cut by transtensive fault systems, that represent the result of the latest tectonic phases related to the tyrrhenian basin quaternary spreading. fault-slip data were collected in 8 measurement sites, for a total amount of 120 measures. measurement sites were positioned in miocene deposits, whereas quaternary deposits do not display any signs of deformation. nevertheless, quaternary tectonics is clearly demonstrated by evidence of uplifted tyrrhenian strandlines (sea caves at about 12 m a.s.l. located near to cetraro, close to the north of the study area, carobene et al., 1986; carobene, 1987; bordoni & valensise, 1998), and by cross-cut relationships between marine terraced deposits and fault systems (tortoricii et al., 2002); furthermore, from a geomorphological point of view, the fact that remnants of perched alluvial terraces are not related to any present-day or past landform and are located close to the escarpment bounding the mountain front support the quaternary tectonic activity. literature data (tortorici et al., 2002; muto & perri, 2002; tortorici et al., 1995) were used to constrain the chronology and the stress field of the last fault activity. a strong fit exists between the orientation of the main meso-faults and macro-fault systems, plotted in fig. 2 structural data collected in the miocene deposits. a rose diagram of the main meso-faults collected; b rose diagram of the macro-fault systems mapped in the study area; c lower hemisphere stereographic projection of the nnw trending fault system with the latest kinematic indicators on the planes; d lower hemisphere stereographic projection of the ne trending fault system with the latest kinematic indicators on the planes; e, f lower hemisphere stereographic projection of the nw-se and e-w trending fault systems. dati strutturali rilevati nei depositi miocenici. a rose diagram relativo alle principali mesofaglie misurate. b rose diagram relativo alle macro strutture cartografate; c proiezione stereografica, emisfero inferiore, del sistema di mesofaglie nnw-sse con gli ultimi indicatori cinematici rilevati sui piani; d proiezione stereografica, emisfero inferiore, del sistema di mesofaglie ne-sw con gli ultimi indicatori cinematici rilevati sui piani; e, f proiezione stereografica, emisfero inferiore, del sistema di mesofaglie nw-se e e-w. 220 rose diagrams (figs. 2a and 2b), suggesting that fault slip data well clarify the last kinematics of macro-faults. the main system faults are nnw-, ne-, nwand e-trending. the occurrence of overlapping kinematic indicators on the same fault plane, along with the presence of different slip directions on fault planes having the same strike and dip, allow multiphase tectonics to be outlined. the latest fault kinematics is showed in figs. 2c-f. in particular, fault slip data of the ne-trending systems suggest that their kinematic chronology shifts from left-lateral normal to normal dip-slip faults. the nnw-trending system faults show dip-slip and oblique normal movements; the superimposition of the striations allows a relative chronology of their movement to be fixed, i.e. from dip-slip to right-lateral normal faults. the left lateral ne-trending faults system, compatible with the nnw-trending dip-slip system, is older than the latest phase of movement characterised by dip-slip netrending normal faults and relative nnw-trending right lateral normal faults. the eand nw-trending fault system are oblique normal faults and are characterised by a kinematics which is locally superimposed to left strike-slip ones. the latest kinematic indicators are consistent with an ese-wnw extension interpretation, which represents the main mode of deformation of the calabrian arc since middle pleistocene times (e.g. tortorici et al., 1995). 44.. ggeeoommoorrpphhoollooggyy quaternary deposits of the study area, representing mainly marine and alluvial environments (argnani & trincardi, 1993; sorriso-valvo & sylvester, 1993; sorriso-valvo et al., 1998; robustelli et al., 2002), are hosted in a narrow coastal strip, which can be considered the onshore counterpart of the paola basin infilling. these deposits are limited inland by the coastal range, essentially evolved by slope replacement mechanisms and river dissection. as a consequence of this evolution the west-facing slope of this mountain ridge shows welldefined triangular facets as isolated remnants of the n-s trending fault scarp, partly dismantled. the hydrographic network formed as a response to the coastal range uplift, producing steep catchments debouching seaward from the mountain front, which led to the emplacement of three generations of alluvial fans. as a general rule the drainage pattern follows the main fault system (sylvester et al., 1987; sorriso-valvo & sylvester 1993) and shows several asymmetric valleys. geomorphic evidence suggest that the e-w consequent streams were interrupted and deflected by neand n-s trending subsequent streams, at least in the northern sector of the study area. some morphometric data of the main stream catchments have been calculated, such as the mean drainage basin slope (ds) and the drainage basin area (da), the sweep angle, as (sensu viseras et al., 2003) and the mean slope (fs) of the fans. from these data it can be observed that the source catchments of the major rivers are very steep: the mean slope of the drainage basins, in fact, ranges from 31.43 to 40.65%. on the contrary, the fans are gentler, with mean slopes approximately around 10-14% or lower, except in the case of the t. laponte (fs = 15.48%). on the basis of data provided by robustelli et al. (2002), three generations of alluvial-fans, telescopically arranged, have been distinguished. from a geomorphological point of view, the study area consists of different, narrow geomorphological zones, parallel to the coast and limited by approximately n-s trending scarps probably not related to faults (fig. 3). the piedmont zone comprises the 1st generation of alluvial-fans which are telescopically inset in respect to remnants of perched alluvial terraces (fig. 4a), gently sloping seaward but apparently not related to any present-day or past landform, which hang in some of the main river valleys dissecting the coastal range. a nearly n-s striking scarp borders the piedmont zone; local remnants of eolian deposits, with continental fauna, are well preserved on the basal portion of the foot-zone scarp. quite a similar stratigraphic situation characterises the piedmont zone of the central coastal range (sorriso-valvo & sylvester, 1993), where sandy eolian deposits outcrop along the foot-zone scarp and underlie the youngest alluvial fans. amino-acid racemization dating on helix sp. fix the emplacement of eolian sands at about 70 kyr b.p. (sorriso-valvo, pers. comm.). furthermore, they rest on buried gravel deposits that constitute the bulk on which post-eolian sedimentation took place, as inferred by boreholes data, and are commonly capped by thin layers of slope deposits produced by scarp retreat. hence these eolian sands clearly postdate the 1st generation of alluvial fans (middle-late? pleistocene) and predate the 2nd one (upper pleistocene-holocene) (fig. 4b). the most recent alluvial-fans, late holocene to recent in age, develop close to the present-day coastline, and are substantially inactive and subject to very slight river dissection. they lie upon and are entrenched within late pleistocene–holocene coastal deposits, consisting of beach sands and gravels as well as eolian sands (fig. 3). the bulk of the piedmont zone, reaching an elevation of about 130 m a.s.l., consists of the oldest generation of coalescent alluvial-fans, which show a sweep angle 60°. a particular attention must be given to a huge fan developed at the mouth of t. laponte, which is entrenched in – and partly rests on – the dissected t. maddalena alluvial fan. from the geomorphic relationships between the two alluvial bodies, the laponte fan is obviously younger. although its drainage basin is not the widest (da = 6.32 km2), it is extremely large, with an as value close to a square angle and the feeder channel filled with great amounts of sediments (cf. sorriso-valvo et al., 1998), assuming a typical “mushroom” shape (viseras et al., 2003) in plan view. in the sector between valle santa maria and the t. maddalena, at the toe of the piedmont zone, the lower and younger alluvial fans occur. their sweep angles commonly vary from 30-40°, reaching higher values for the t. mercaudo (60°) and the t. trappeto (about 90°). the above mentioned eolian sands, which taper upslope the nearly n-s striking scarp bordering the piedmont zone, are quartzolithic in composition; they have abundant lithic grains, and mostly equal amounts of quartz and feldspar (qm20 f18 lt62). feldspar is dominantly plagioclase. aphanitic lithic fragments (lm86 lv0 ls14) include abundant metamorphic lithic fragments, represented by phyllite, fine-grained schist and minor fine-grained gneiss and amphibolite; sedimentary f. muto et al. 221 fig. 3 geomorphological sketch map of the study area. schema geomorfologico dell’area di studio. geomorphology, tectonics and sedimentology... 222 lithic fragments are subordinate and include micritic and sparitic limestone, dolostone and metalimestone lithic fragments. coarse–grained rock fragments include plutonic (mostly granodiorite and minor granite) and gneiss rock fragments. the abundant metamorphic detritus is derived from the diverse tectonostratigraphic units of the coastal range, bagni, castagna and polia copanello units (amodio morelli et al., 1976; dietrich, 1976; colonna & compagnoni, 1982), whereas the sedimentary detritus is derived from mesozoic to miocene sedimentary strata of the san donato and verbicaro units (amodio morelli et al., 1976) and the miocene sedimentary successions (di nocera et al., 1974; mattei et al., 2002; muto & perri, 2002). a fine-textured, greyish tephra layer, about 20 cm thick, is interbedded within their upper portion and consists of impure volcanoclastic sands. volcanic detritus includes pumice fragments, having vitric texture, and sometimes including plagioclase, pyroxene and biotite crystals. rare volcanic lithic fragments exhibiting microlitic texture consist of particles having plagioclase, biotite and pyroxene microlithes, and a vitric groundmass. in addition to volcanic detritus, the sample contains various non-volcanic detritus, which includes single quartz and feldspars, metamorphic and carbonate lithic fragments, and coarse-grained plutonic rock fragments. micrite and microsparite interstitial component constitutes matrix and early cement of the sample. 55.. aalllluuvviiaall--ffaann ssttrraattiiggrraapphhyy on the basis of geomorphic analysis, described in the previous section, the quaternary alluvium consists of perched valley-side terraced deposits and alluvial fan deposits; the latter comprise two generations of alluvial fans, telescopically arranged. alluvial-fan deposits are characterised by the dominance of conglomerates; finegrained facies were not observed. the clast lithology slightly varies over the study area; dominant clasts include ophiolitic units, phyllites, gneiss, schists, granites and sedimentary rocks. because of the dearth of exposures which affect valley-side terraced deposits, sedimentary facies analysis has concerned only alluvial-fan facies. in particular a number of stratigraphic sections have been measured in order to give the sedimentary logs of fig. 4, because of the vertical cliffs which confine the piedmont zone allufig. 4 overviews showing the morphologic relationships among the perched alluvial terraces, the mountain front and the piedmont alluvial fans (a) and between the piedmont and the coastal alluvial fans (b). foto panoramiche che illustrano i rapporti tra i terrazzi fluviali sospesi ed il fronte montuoso ed i conoidi pedemontani (a), e tra i conoidi pedemontani e costieri (b). f. muto et al. vial fan; therefore sections were obtained along river incision and road cuts and extend parallel to fan-slope up to 9 m in width, and are representative of the uppermost portion of alluvial fans. as far as coastal-plain alluvial fans are concerned, thanks to excavations for the foundation of buildings located in the middle portion of t. trappeto coastal fan, the relative sedimentary log (fig. 4) is given; unfortunately no sections are available for t. mercaudo and t. maddalena coastal fans, because of the lack of artificial and natural exposures, the latter owing to slight river dissection. the base of both generations of alluvial fans is not exposed; the maximum thickness, provided by well log data, is 45 m and 35-40 m for the coastal and piedmont alluvial deposits, respectively. according to robustelli et al. (2002), the latest phases of fan development occurred during climate amelioration following glacial periods, when increasing moisture and temperatures, enabling bio-chemical rock degradation, and increasing run-off allow slope-waste materials to be removed, mainly by gravity and subordinately tractive processes. 55..11 ffaacciieess aannaallyyssiiss the quaternary alluvium is characterised by a variety of coarse-grained lithofacies coming to be regarded as alluvial-fan facies. in particular detailed facies analysis revealed the presence of 5 sedimentary facies, discussed below, which are described on the basis of clast-size, bedding, sedimentary structures and shape of the units. three sedimentary logs are given in fig. 4; they are representative of the uppermost part of the t. trappeto piedmont fan, t. maddalena piedmont fan and t. trappeto coastal fan. ffaacciieess 11 - ssttrruuccttuurreelleessss,, ccoobbbbllee ttoo bboouullddeerr--ssiizzee ccoonngglloo-mmeerraattee no good exposures of this facies occur in the study area; a number of very small outcrops occur along roads ascending t. laponte alluvial-fan apex zone, and as subordinate facies alternating in t. maddalena alluvial-fan deposits. the latter allows facies analysis to be made. this facies consists of massive, monomictic, matrix to clast supported conglomerates of cobble to boulder grade. basal surfaces of these beds, up to 1.8 m thick, are sharp and display fairly erosional features. matrix content is locally abundant; it consists of a mixture ranging from silt to pebble, seemingly of the same composition as the largest clasts; the latter are angular to subangular in shape, and it is worth noting the presence of shattered ones. fabric is disorganized, although uncommon, crudely coarse-tail inverse grading occurs. ffaacciieess 22 - ssttrruuccttuurreelleessss,, ccllaasstt--ssuuppppoorrtteedd ccoonngglloommeerraattee massive, poorly sorted, sheet conglomerates comprise this facies. bed thickness varies between 0.4 and 1.2 m. basal bedding contacts are sharp and slightly irregular, with relief of up to 0.15 m; scour surfaces may be observed, but they are very uncommon. the debris consists of pebble to cobble-size clasts, ranging from angular to subrounded in shape. matrix in an unsorted mixture varying between silt and fine-grained pebble, and is rarely sufficiently abundant to support clasts. fabric is disorganized, although the longest a-axes of some elongate clasts may be seen parallel to paleoflow and imbricated a(p), a(p)a(i). grading is absent or basal inverse grading locally occurs. ffaacciieess 33 - iinnvveerrsseellyy ggrraaddeedd,, ccllaasstt--ssuuppppoorrtteedd ccoonngglloommee-rraattee inversely graded, clast-supported, poorly to moderately sorted sheet conglomerates characterise this facies. basal surfaces of the beds, up to 0.5 m in thickness, are sharp and non erosive. pebble to cobble-size clasts comprise this facies, ranging from angular to subrounded in shape. matrix, varying between sand to fine pebble, is never sufficiently abundant. inverse-grading is well developed; inverse to normal grading is uncommon (fig. 5a). clast fabric locally displays a preferred a(p)a(i) clast orientation. ffaacciieess 44 –– hhoorriizzoonnttaallllyy,, ccrruuddeellyy ssttrraattiiffiieedd ccllaasstt--ssuuppppoorr-tteedd ccoonngglloommeerraattee this facies is characterised by vertically alternating couplets of clast-supported sheet conglomerates (fig. 5b); beds of this facies, up to 0.4 m thick, have sharp, non erosive basal bedding contacts. the debris consists of subangular to subrouded pebble to cobble grade and pebble to pebbly granule gravels. the coarse gravel units, occasionally clast-thick, are massive and moderately sorted; crude normal gradind may occur. imbrication, locally well developed, is variable, showing a(p)a(i) and a(t)b(i) fabric modes. the finer grained beds seem to be more extensive than the coarse grained ones; they are moderately to well sorted and no grading has been observed. pebblesize clasts show a local a(t) b(i) fabric mode. outsized clasts, of coarse pebble to fine cobble grade, are sparsely present and their long axis are aligned both parallel and normal to bedding planes. ffaacciieess 55 –– lleennttiiccuullaarr,, ccllaasstt--ssuuppppoorrtteedd ccoonngglloommeerraattee this facies rests on facies 2 and 3; it consists of moderately to well sorted, clast-supported, lenticular gravel units up to 0.2 m thick and varying between 0.6 and 1.1 m in width. granule to fine pebble-size clasts comprise this facies. grading is absent, although crudely normal grading locally occurs. imbrication may be well developed, showing a(t)b(i) fabric mode. 55..22 iinntteerrpprreettaattiioonn aanndd ffaacciieess aassssoocciiaattiioonnss detailed facies analysis revealed the presence of five facies, the interpretation of which has been described accordingly as follows. lateral and vertical facies associations, coarse-grained texture, disorganized fabric, together with geomorphic analysis suggest that the depositional events were of very high-energy and consistent with an alluvial-fan depositional system. ffaacciieess 11:: ddeebbrriiss--aavvaallaanncchhee ddeeppoossiittss the conglomerates of facies 1 are massive, monomictic, matrix to clast supported and cobble to boulder grade; these features suggest high-energy depositional events. furthermore, the angular nature of the gravel clasts, locally shattered, their monomictic composition and their poor sorting are interpreted as deposition by debrisavalanche events (sorriso-valvo, 1988; yarnold & 223geomorphology, tectonics and sedimentology... lombard, 1989; yarnold, 1993; blair & mcpherson, 1994). this facies results from failure of a large fractured and weathered bedrock cliffs which, during downward fall was characterised by partial disintegration; in fact shattered boulders, but also very weathered angular clasts, may be observed. a clayey reddish-brown paleosol layer, with wavy upper and lower boundaries, rests on this facies association (robustelli et al., 2002). ffaacciieess 22:: ddeebbrriiss--ffllooww ddeeppoossiittss the massive, sheet-like, non erosive based, poorly sorted, clast-supported nature of this facies suggest that depositional events were of high-energy, i.e. unconfined debris-flow. according to shultz (1984), this facies is interpreted as depositional evidence of pseudoplastic debris flow; in particular these units may represent the deposits of cohesionless debris-flow (smith & lowe, 1991; sohn et al., 1999) dominated by frictional grain interactions in which clast collision is hampered, resulting in the lack of inverse grading and clast imbrication. the local a(p)a(i) clast fabric indicates that brief or transient laminar shear affected debris flow (e.g. nemec & postma, 1993). beds with coarse-tail basal inverse grading are indicative of non-shearing rigid plugs resting on the basal part of flows affected by intense laminar shear (nemec & postma, 1993; johnson & rodine, 1984; sohn et al., 1999). ffaacciieess 33:: ccllaasstt--rriicchh ddeebbrriiss--ffllooww ddeeppoossiittss facies 3 is interpreted as the deposits of high-concentration flows. the low matrix content, the framework support, the a(p)a(i) clast imbrication and the upward coarsening trend are thought to be evidence of clast-rich debris flow (shultz, 1984). generally the above described features are consistent with deposition of unconfined, cohesionless debris flows (nemec & steell, 1984; shultz, 1984; smith, 1986; smith & lowe, 1991), and the inverse grading being representative of granular flows in which a dispersive pressure dominates during motion (lowe, 1982; todd, 1989; sohn et al, 1999). this facies may also be interpreted as representative of very high sediment-concentration dispersions, such as hyperconcentrated flood-flows, i.e. dilution of debris flows (pierson, 1980; pierson & scott, 1985; ridgway & decelles, 1993; smith & lowe, 1991 among others). ffaacciieess 44:: sshheeeettfflloooodd ddeeppoossiittss the dominance of horizontally stratified conglomerates, characterised by vertically alternating couplets of coarse and fine grained beds, indicates that high-energy tractional processes were involved. in particular, the tabular conglomerate sheets suggest that deposition was laterally extensive. as a whole this facies is interpreted as being formed by deposition of unconfined sheetflood pulses well testified by the alternating couplets of different clast-size (e.g. blair & mcpherson, 1994). high-density flood-flow interpretations, in particular hyperconcentrated flood flows (sensu smith, 1986; smith & lowe, 1991), may also be suggested by the clast fabric, including the outsized ones within the finergrained beds. ffaacciieess 55:: ssttrreeaamm--ffllooww ddeeppoossiittss facies 5 is thought to be deposited by low-energy stream flow. evidence for stream-flow processes include 224 fig. 5 logs of the alluvial fan conglomerates. numbers refer to l i thofacies. letters refer to facies associations (see the text for details). sezioni stratigrafiche dei c o n g l o m e r a t i al luvionali. le lettere si riferiscono alle litofacies. le sigle si riferiscono alle associazioni di facies (si veda il testo per i dettagli). f. muto et al. framework-support, a(t)b(i) imbrication, sorting and the lenticular geometries of individual units. this facies is associated with beds of facies 2 and 3, on which it commonly rests, and are representative of deposition in small channels that developed over fan-slope after debris-flow deposition; in particular these lenticular gravel beds are thought to be produced by fine-fraction winnowing on the debris-flow by overland water flows (blair & mcpherson1994). ffaacciieess aassssoocciiaattiioonnss lateral and vertical facies association, coarsegrained texture, disorganized fabric, together with geomorphic analysis suggest that the depositional events were of very high-energy and consistent with an alluvialfan depositional system. four facies associations have been distinguished and discussed below. ffaacciieess aassssoocciiaattiioonn aa is restricted to the base of the upper portion of t. maddalena piedmont fan and t. laponte fan; the few and scattered road-cut sections and observations of the cliffs from a distance indicate that this facies association consists of vertically alternating debris flow and, subordinately, debris avalanche deposits. very uncommon beds of facies 5 may occur. ffaacciieess aassssoocciiaattiioonn bb characterised the upper portion of t. maddalena piedmont fan. the most common facies is the massive, poorly sorted, clast-supported sheet conglomerates (facies 2). subordinate facies are represented by inversely graded conglomerates (facies 3) and clast-supported, lenticular units (facies 5) of granule-pebble grade. ffaacciieess aassssoocciiaattiioonn cc constitutes the bulk of the upper portion of t. trappeto piedmont fan. it consists of alternating debris flow (facies 2, 3) and sheetflood (4) facies; lenticular units (facies 5) produced by fine-fraction winnowing on the debris-flow are also common. ffaacciieess aassssoocciiaattiioonn dd is restricted to the upper portion of t. trappeto coastal fan and consists of debris flow deposit (facies 2) usually capped by conglomerate lenses of facies 5. sheetflood facies are uncommon. this facies association, though analogous to facies association c, is characterised by a decrease in clastsize. for instance debris-flow deposits of pebble to cobble grade and pebble to fine cobble grade characterised t. trappeto piedmont and coastal fan, respectively (robustelli et al., 2002). 66.. ddiissccuussssiioonn aanndd ccoonncclluussiioonn on the basis of all data collected by means of an integrated geomorphological, structural and sedimentological approach, interesting issues can be addressed to discuss the late quaternary fan evolution along the northwestern sector of the coastal range. a strong structural control of drainage pattern is highlighted. to the north of the study area stream directions follow strikes and fold axes trends of the miocene sedimentary cover. moving southward the drainage network, although following faults pattern, is superimposed over the fold limb of the miocene succession. as resulting from structural and morphotectonic studies addressed to paleostress reconstruction in an area close to the south (muto & perri, 2002; tortorici et al., 2002), the last tectonic phase was probably characterised by a nw-se trending extension direction and was responsible for the creation and re-activation of netrending faults; furthermore, it caused the reactivation of the nnw-trending ones with right lateral transtensive kinematics. this tectonic phase can be ascribed to middle-late? pleistocene on the basis of cross-cut relationships between marine terraced deposits and fault systems (tortorici et al., 2002); it could have been the cause of landscape fragmentation, by interrupting the continuity of a possible pre-existing coastal plain and producing valley-side perched alluvial terraces, as also testified by the lack of landforms related to the perched terraces (figs. 3 and 7a). the following development of the 1st generation of alluvial fans tapered upslope the triangular facets and sealed the fault scarps (fig. 7b) created by the previous block-faulting. since that time fan development was mainly related to eustacy, as suggested by robustelli et al. (2002) and briefly reported in section 1. the bathymetric maps of the continental shelf 225 fig. 6 alluvial fan facies. a inverse grading sheet conglomerates interpreted as pseudoplastic debris flow (see the text for details); b alternating couplets of sheetflood facies; a(p) fabric mode is well noticeable. particolari delle facies che caratterizzano i conoidi alluvionali. a conglomerati a gradazione inversa interpretati come la deposizione ad opera di debris flow pseudoplastici; b alternanza di coppie di livelli conglomeratici a differente granulometria interpretati come depositi di lame di piena (sheetflood); risulta ben evidente la disposizione dell’asse maggiore dei clasti, parallela alla superficie di stratificazione (a(p)). geomorphology, tectonics and sedimentology... (present seafloor isobaths; argnani & trincardi, 1988; chiocci et al., 1989), as well as the maps reporting the reconstruction of the last glacial erosional surface and the total thickness of holocene deposits provided by chiocci et al. (1989) and chiocci & orlando (1995), show patterns of seafloor dip and slope scarps orientation, which widely match with the strikes of the main fault system observed onshore, i.e. ne-, nnw-, nwand e-trending faults as the well-known falconara fault (turco et al., 1990) it may suggest that the above mentioned tectonic phase has lasted at least till late upper pleistocene. moreover, offshore from capo bonifati (just a few kilometres northwest of the study area) and from guardia piemontese, sharp breaks in slope approximately at depths of 75-90 m b.s.l. can be clearly recognised. these scarps border offshore two flat surfaces, which chiocci et al. (1989) simply interpret as erosional terraces related to sea-level stillstands. the complete lack of late pleistocene marine terraces in the study 226 fig. 7 main stages of late quaternary morphotectonic evolution of the study area (see the text for details). principali fasi dell’evoluzione morfotettonica tardo-quaternaria dell’area in esame (si veda il testo per i dettagli). f. muto et al. area, which, on the contrary, developed during pleistocene times and were tectonically uplifted to different heights both in the northern and the southern sector of the tyrrhenian coast of calabria (carobene & dai pra, 1990; carobene & ferrini, 1993; tortorici et al., 2002) could be explained in two different ways: (i) the rates of sea-level rise and tectonic uplifts were substantially equal in the study area, so that the terraces never formed (cinque et al., 1993); (ii) the terraces really did form indeed and were subsequently submerged for subsidence phenomena involving this onshore sector of the paola basin. in the latter case, it could be hypothesised that the flat surfaces, occurred on continental shelf and identified from seismic data, would tentatively be related to the above mentioned wave-cut marine platforms (buried by holocene deposits), and be the submerged counterpart of the adjacent, raised late pleistocene terraces. what is more, the presence of huge bioherm structures, up to several tens of metres high, just close to the slope break of these flat morphologies (chiocci et al., 1989) supports this idea: in addition, encrusting marine organisms of this kind usually develop in limpid and relatively shallow water (photic zone) and their relics often outcrop at the top of marine terraces of different ages all along the south tyrrhenian sea coast (e.g. brancaccio et al., 1990; carobene & dai pra, 1990; iannace et al., 2001; riccio et al., 2001; scarciglia et al., 2003). their extreme vertical extension could be related to their rapid growth upwards concurrently with the progressive land subsidence and relative sea-level rise, just to maintain their suitable life environment. furthermore, the landward migration of holocene depositional depocenters (chiocci et al., 1989; chiocci, 1994) and their location at the mouth of the major streams dissecting the coastal range and debouching along the west coast (argnani & trincardi, 1988; 1993), which clearly indicate a strong control by sediment input from continental feeding sources, could have also been favoured by subsidence. some parameters used in the morphometric analysis of alluvial fans (e.g. viseras et al., 2003) may support this hypothesis; in fact weak tectonic subsidence, coupled with marine base level rise, may constitute the main mechanisms promoting the creation of the accommodation space for fan aggradation. in fact, it is worth noting that to the north of the study area uplift rates are very low (0.05 mm/yr, carobene et al., 1986; bordoni & valensise, 1998). in addition, robustelli et al. (2002) already highlighted that important fan development occurred in the study area during transitions toward interglacial periods, characterised by climatic amelioration and significant sea-level rise. both the peculiar “mushroom” shape and the high sweep angle values measured for late pleistoceneholocene fans (fig. 3), can be interpreted as due to low subsidence and sea-level rise, combined with high sediment input, which produce a retrograding stacking pattern, with a mountain embayment associated with an expansion of the fan (viseras et al., 2003). furthermore, the lack of fault evidence within the alluvial fan successions could be related just to the low rates of subsidence. as far as facies analysis are concerned, factors that control alluvial fan facies assemblages have been identified. moving northward, t. maddalena and t. trappeto alluvial fan deposits consist of slightly different facies associations (fig. 5). t. maddalena piedmont fan was built solely by sediment gravity flows (debris avalanche and debris flow processes), whereas t. trappeto piedmont fan deposits consist of alternating sediment gravity flows (debris flow processes) and fluid gravity flows (sheetflooding). in both cases, secondary processes, i.e. overland flows, caused locally winnowing of the top surfaces. some features, such as climate, vegetation types, tectonic setting etc. are thought to have been approximately the same during fan construction. even though the t. maddalena catchment area is larger than the t. trappeto one (12.02 km2 vs. 6.26 km2), this feature, as other fan and catchment morphometric data, are not prerequisites to promote different facies assemblages (e.g. blair, 1999). according to blair (1999) and blair & mcpherson (1994), lithology of the bedrock underlying fan catchments is thought to control the slight differences in depositional processes and relative facies associations, i.e. weathering caused differences in sediment particle-size, influencing permeability, which may promote sediment gravity flows vs. fluid gravity flows. although the bulk of the bedrock underlying fan catchments at issue comprises quite similar lithologies, major exposures of schists and phyllites of the ophiolitic units in the t. maddalena fan catchment (28% vs. 15%) may be considered as the main key factor in the differences among facies assemblages. furthermore, the finer-grained facies, characterising coastal fans in respect to piedmont ones (robustelli et al., 2002), may be interpreted as the sedimentary response to different alluvial fan evolutionary stages, reflecting the progressive increase of drainage basins size, coupled with the decrease of drainage basins slope (e.g. blair & mcpherson, 1994). aacckknnoowwlleeddggmmeennttss the authors are grateful to mr. francesco colonnese for the preparation of thin sections. they also wish to thank prof. l. carobene and prof. t. pescatore for their comments and suggestions helpful for the improvement of the manuscript. this work is financially supported by murst 60% (prof. s. crivelli). rreeffeerreenncceess amodio-morelli l., bonardi g., colonna v., dietrich d., giunta g., ippolito f., liguori v., lorenzoni s., paglionico a., perrone v., piccarretta g., russo m., scandone p., zanettin-lorenzonii e. & zuppetta a. (1978) – l’arco calabro-peloritano nell’orogene appenninico-maghrebide. mem. soc. geol. it., 1177, 1-60. argnani a. & trincardi f. (1988) – paola slope basin: evidence of regional contraction on the eastern tyrrhenian margin. mem. soc. geol. it., 4444, 93-105. argnani a. & trincardi f. (1993) – growth of a slope ridge and its control on sedimentation: paola slope basin (eastern tyrrhenian margin). spec. pubbl. int. ass. sediment., 2200, 467-480. 227geomorphology, tectonics and sedimentology... barone a., fabbri a., rossi s. & sartori r. (1982) – geological structure and evolution of the marine areas adjacent to the calabrian arc. earth evolution sciences, 33, 207-221. blair t.b. (1999) – cause of dominance by sheetflood vs. debris-flow processes on two adjoining alluvial fans, death valley, california. sedimentology, 4466,, 10151028. blair t.b. & mcpherson j.g. (1994) – alluvial fans and their natural distinction from rivers based on morphology, hydraulic processes, sedimentary processes and facies assemblages. j. sedim. research, a64, 33, 450-489. bordoni p. & valensise g. (1998) – deformation of the 125ka marine terraces in italy: tectonic implications. in: stewart i., vita-finzi c. (eds), “coastal tectonics”, geol. soc. london, spec. pubbl. 114466, 71-110. boullin j.p. (1984) – nouvelle interpretation de la liason apennine-maghrébides en calabre: consequences sur la paléogéographie téthysienne entre gibraltar et les alpes. rev. geol. dyn. geogr. phys., 2255, 321-338. brancaccio l., cinque a., russo f., belluomini g., branca m., delitala l. (1990) – segnalazione e datazione di depositi tirreniani sulla costa campana. boll. soc. geol. it., 110099, 259-265. canu m. & trincardi f. (1989) – controllo eustatico e tettonico sui sistemi deposizionali nel bacino di paola (plio-quaternario), margine tirrenico orientale. giornale di geologia, 5511, 41-61. carobene l. (1987) – antiche linee di riva ed aspetti di geologia del quaternario. guida alle escursioni nella calabria settentrionale tra marina di maratea e cetraro. 25-30 maggio, 66pp.. carobene l., dai pra g. & gewelt m. (1986) – niveaux marins du pleistocene moyen-superieur de la cote tyrrhenienne de la calabrie (italie meridionale). datations 230th/234u et tectonique recente. z. geomorph. n. f., suppl. bd. 6622, 141-158. carobene, l. & dai pra, g. (1990) – genesis, chronology and tectonics of the quaternary marine terraces of the tyrrhenian coast of northern calabria (italy).their correlation with climatic variations. il quaternario, 33, 75-94. carobene l. & ferrini g. (1993) – morphological, sedimentological and tectonic features of diamantemt. carpinoso marine terrace flight (tyrrhenian coast of the northern calabria, italy). earth surf. proc. landforms, 1188,, 225-230. chiocci f.l. (1995) very high-resolution seismics as a tool for sequence stratygraphy applied to outcrop scaleexamples from eastern tyrrhenian margin olocene /pleistocene deposits. aapg bulletin, vol. 7788, no 3 (march 1994), 378-395. chiocci f.l., d’angelo s., orlando l. & pantaleone e a. (1989) – evolution of the holocene shelf sedimentation defined by high-resolution seismic stratigraphy and sequence analysis (calabro-tyrrhenian continental shelf). mem. soc. geol. it., 4488, 359-380. chiocci f.l. & orlando l. (1995) – effects of high frequency pleistocene sea level changes on a highly deforming continental margin: calabrian shelf (southern tyrrhenian sea, italy) bollettino di geofisica teorica ed applicata, 3377, 39-58. cinque a., de pippo t., romano p., 1995 coastal slope terracing and relative sea-level changes: deductions based on computer simulations. earth surf. process. landforms, 2200,, 87-103. colonna v., & compagnoni r. (1982) guida all’escursione sulle unità cristalline della catena costiera (calabria). rend. soc. geol. it. min. e petrol., 3388 (3), 1141-1152. dewey j.f., helmann m.l., turco e., hutton d.h.w. & knott s.d. (1989) kinematics of the western mediterranean. in alpine tectonics, coward, m.p., d. dietrich and r.g. park. (ed.s), geol. soc. spec. publ., 4455, 265-283. di nocera s., oortolani f., russo m., & torre m. (1974) successioni sedimentarie messiniane e limite miocene-pliocene nella calabria settentrionale. boll. soc. geol. it., 9933, 575-607. dietrich d. (1976) la geologia della catena costiera calabra tra cetraro e guardia piemontese. mem. soc. geol. it., 1177, 61-121. fabbri a., gallignani p. & zitellini n. (1981) – geologic evolution of the peri-tyrrhenian sedimentary basins. in: wezel f.c. (ed), “sedimentary basins in mediterranean margins”, tecnoprint, bologna, 101-126. finetti i. & del ben a. (1986) geophisical study of the tyrrhenian opening. boll. gef. teor. appl, 2288, 75155. gallignani p. (1982) recent sedimentation processes of the calabria continental shelf and slope (tyrrhenian sea, italy). oceanologica acta, 55, 493-500. harvey a.m., silva p.g., mather a.e., goy j.l, stokes m. & zazo c. (1999) – the impact of quaternary sea-level and climatic change on coastal alluvial fans in the cabo de gata ranges, southeast spain. geomorphology, 2288, 1-22. iannace a., romano p., santangelo n., santo a. & tuccimei p. (2001) the ois 5c along licosa cape promontory (campania region, southern italy): morphostratigraphy and u/th dating. zeit. geomorph., 4455(3), 307-319. kastens k.a. & mascle j. (1990) – proc. ocean drilling program, scientific results 107, ocean drilling program, college station, tx. knott s.d. (1987) the liguride complex of souther italy. a cretaceous to paleogene accretionary wedge. tectonophysics, 114422, 217-226. lowe d.r. (1982) – sediment gravity f lows ii: depositional models with special reference to the deposits of high-density turbidity currents. j. sediment. petrol., 5522, 279-297. major j.j. & pierson t.c. (1992) debris flow rheology: experimental analysis of fine-grained slurries. water resources research, 2200, 3, 841-857. mattei m., cipollari p., cosentino d., argentieri a., rossetti f., speranza f., & di bella l. (2002) the miocene tectono-sedimentary evolution of the southern tyrrhenian sea: stratigraphy, structural and paleomagnetic data from the onshore amantea basin (calabrian arc, italy). basin research, 1144, 147-168. messina a, barbieri m., compagnoni r., de vivo b., perrone v., russo s., & scott b. (1981) geological and petrochemical study of the sila massif plutonic rocks (northern calabria, italy). boll. soc. geol. it., 111100,165-206. 228 f. muto et al. muto f. & perri e (2002) – evoluzione tettono-sedimentaria del bacino di amantea, calabria occidentale. boll. soc. geol. it., 112211, 391-409.. nemec w. & postma g. (1993) – quaternary alluvial fans in southwestern crete: sedimentation processes and geomorphic evolution. in marzo m., puigdefabregas c. (eds) alluvial sedimentation. int. assoc. sedimentol. spec. publ., 1177, 235-276. nemec w. & steel r.j. (1984) – alluvial and coastal conglomerates: their significance features and some comments on gravelly mass-flow deposits. in: koster e. h., steel r. j. (ed.s). sedimentology of gravels and conglomerates. can. soc. petrol. geol. mem., 1100, 1-31. ogniben l. (1973) schema geologico della calabria in base ai dati odierni. geol. romana, 1122, 243-585. patacca e., sartori r. & sscandone p. (1990) tyrrhenian basin and appenninic arcs: kinematic relations since late tortonian times. mem. soc. geol. it., 4455, 425-451. patacca e. & scandone p. (1989) post tortonian mountain building in the appennines. the role of passive sinking of a relic lithospheric slab. in: boriani a., bonafede m., piccardo g.b. & vai g.b. (eds), “the lithosphere in italy. advances in earth science research” atti conv. accad. lincei, 8800, 157-176. pierson t.c. (1980) – erosion and deposition by debris flows at mt. thomas, north canterbury, new zealand. earth surf. processes, 55, 227-247. pierson t.c & scott k.m. (1985) – downstream dilution of a lahar: transition from debris flow to hyperconcentrated streamflow. water resour. res., 2211, 1511-1524. rehault j.p., moussat e. & fabbri a. (1987) – structural evolution of the tyrrhenian back-arc basin. marine geology, 112222, 5-21. riccio a., riggio f., romano p. (2001) sea level fluctuations during oxygen isotope stage 5: new data from fossil shorelines in the surrento peninsula (southern italy). zeit. geomorph., 4455(1), 121-137. ridgway k.d. & decelles p.g. (1993) – stream-dominated alluvial fan and lacustrine depositional systems in cenozoic strike-slip basins, denali fault system, yukon territoty, canada. sedimentology, 4400, 645-666. robustellii g., muto f., scarciglia f., spina v. (2002) late quaternary fan development and sea level change along the tyrrhenian sea coast of calabria (southern italy). studi geologici camerti, nuova serie, 22, 135-145. scarciglia f., terribi le f., colombo c. (2003) micromorphological evidence of paleoenvironmental changes in northern cilento (south italy) during the late quaternary. catena, 5544 (3), 515-536. shultz a.w. (1984) – subaerial debris-flow deposition in the upper paleozoic cutler formation, western colorado. j. sediment. petrol., 5544, 759-772. smith g.a. (1986) – coarse-grained nonmarine volcanoclastic sediment: terminology and depositional processes. geol. soc. am. bull., 9977, 1-10. smith g.a. & lowe d.r. (1991) – lahars: volcanohydrologic events and deposition in the debris flow-hyperconcentrated flow continuum. in: fisher r. v., smith g. a. (ed.s) sedimentation in volcanic settings. sepm, spec. pubbl., 4455, 59-70. sohn y.k., rhee c.w. & kim b.c. (1999) – debris flow and hyperconcentrated flood-flow deposits in an alluvial fan, northwestern part of the cretaceous yongdong basin, central korea. j. geol., 110077, 111-132. sorriso-valvo m. (1988) – landslide-related fans in calabria. catena suppl.,, 1133, 109-121. sorriso-valvo m., antronico l. & le pera e. (1998) – controls on modern fan morphology in calabria, southern italy. geomorphology, 2244, 169-187. sorriso-valvo m. & sylvester a.g. (1993) – the relationship between geology and landforms along a coastal mountain front, northern calabria, italy. earth surf. proc. landforms, 18, 257-273. sylvester a.g., zeck s.e.a.,& sorriso-valvo m. (1987) tectonogeomorphic response to neotectonics, southern italy. international symposium on the tectonic evolution and dynamics of the crustal lithosphere, ii beijing, china, 1-3. todd s. p. (1989) – stream-driven, high-density gravelly traction carpets: possible deposits in the trabeg conglomerates formation, sw ireland and some theoretical considerations of their origin. sedimentology, 3366, 513-530. tortorici l. (1982a) analisi delle deformazioni fragili dei sedimenti postorogeni della calabria settentrionale. boll. soc. geol.it., 110000(3), 291-380. tortorici l. (1982b) lineamenti geologico strutturali dell ’arco calabro-peloritano. rend. soc.it. mineral.e petrol., 3388(3), 927-940. tortorici g., bianca m., monaco c., tortorici l., tansi c. de guidi g. & catalano s. (2002) – quaternary normal faulting and marine terracing in the area of capo vaticano and s. eufemia plain (southern calabria). studi geol. camerti, 11, 155-171. tortorici l., momano c., tansi c. & cocina o. (1995) – recent and active tectonics in the calabrian arc (southern italy). tectonophysics, 224433,, 37-55. turco e., maresca r. & cappadona p. (1990) – la tettonica plio-pleistocenica del confine calabro-lucano: modello cinematica. mem. soc. geol. it., 4455, 519-529. verstappen h.t. (1977) – a geomorphological survey of the nw cosenza province, calabria, italy. itc journal, 44, 578-594. viseras c., calvache m.l., soria j.m. & fernandez j. (2003) differential features of alluvial fans controlled by tectonic or eustatic accommodation space. geomorphology, 5500,181–202. yarnold j.c. (1993) – rock-avalanche characteristics in dry climates and the effect of flow into lakes: insights from the mid-tertiary sedimentary breccias near artillery peak, arizona. geol. soc. am. bull., 110055,, 345-360. yarnold j.c. & lombard j.p.(1989) – facies model for large block avalanche deposits formed id dry climates. in colburn i.p., abbott p.l. and minch j. (ed.s), conglomerates in basin analysis. sepm pacific section symposium book, 6622, 9-32. 229 ms. ricevuto il 6 maggio 2003 testo definitivo ricevuto il 19 settembre 2003 ms. received: may 6, 2003 final text received: september 19, 2003 geomorphology, tectonics and sedimentology... imp.narcisi qquuaatteerrnnaarryy ddiissttaall tteepphhrraa llaayyeerrss iinn iittaallyy aanndd tthhee aaddjjooiinniinngg sseeaass:: ccuurrrreenntt kknnoowwlleeddggee aanndd pprroossppeeccttss ffoorr ffuuttuurree rreesseeaarrcchh bbiiaannccaammaarriiaa nnaarrcciissii enea c.r. casaccia, c.p. 2400, 00100 roma, italy narcisi@casaccia.enea.it abstract tephrochronological studies on quaternary sedimentary successions of the central mediterranean area are reviewed and critically evaluated, with emphasis on the use of distal ash layers for land-sea correlations. the longest tephra records are provided by the deep-sea sediments from the basins adjoining italy, which have been extensively studied in the last 30 years. shorter (<100 ka), yet still significant records of ash layers have been recovered in lacustrine basins of the italian peninsula. the longest successions show that the tephra layers increase toward the top of the quaternary record. the dominant pliocene and lower pleistocene tephra sources were likely represented by the volcanoes of the pontine islands and the aeolian arc, while in the middle-upper pleistocene and holocene times aeolian and campanian products have been predominant. tephra correlation is made difficult by the fact that the volcaniclastic products are extensively reworked by epiclastic processes, even in the marine setting. inconsistent analytical approaches used in the old and recent work (bulk sample versus grain-discrete analysis) hinder integration of the available evidence. the regional tephrostratigraphy of early and middle pleistocene ages is not established yet, because data are scarce and fragmentary and ages of tephra are poorly defined. tephra correlation is frequent in the late quaternary time span, in which several widespread marker-tephras have been identified. recent findings extend the known distribution of the main late pleistocene markers and suggest complex dispersal patterns, including deposition towards north and northeast. occurrence of quaternary tephra layers of probable italian origin in sites of central and eastern europe opens the prospect for precise correlation of sedimentary records across the european continent. finally, reliable linking of chemical spikes in north polar records to italian explosive eruptions could be critical for a better understanding of palaeoenvironmental issues. riassunto tephra distali quaternari in italia e nei mari adiacenti: stato delle conoscenze e prospettive di ricerca. questo lavoro prende in rassegna gli studi tephrocronologici effettuati sulle sequenze sedimentarie dell’area centro-mediterranea ed effettua una sintesi delle conoscenze disponibili, particolarmente per quanto concerne le informazioni utili per correlazioni fra successioni marine e successioni continentali. le tephro-sequenze più rilevanti per continuità stratigrafica ed estensione temporale riguardano i sedimenti di mare profondo, i quali sono stati diffusamente campionati e analizzati nel corso degli ultimi 30 anni. in ambiente continentale, i risultati più significativi provengono dallo studio di lunghe sequenze lacustri dell’italia peninsulare, campionate per indagini paleoclimatiche. i dati delle sequenze più lunghe indicano che i livelli piroclastici aumentano nel quaternario superiore. relativamente alle sorgenti vulcaniche, durante il pliocene ed il pleistocene inferiore prevalgono prodotti dei vulcani delle isole pontine e dell’arco eoliano, mentre nel pleistocene mediosuperiore e nell’olocene sono preponderanti i prodotti eoliani e quelli campani. la correlazione tra livelli di tephra, compresi quelli contenuti nelle sequenze di ambiente marino profondo, è complicata dal rimaneggiamento del materiale piroclastico. la disomogeneità dei dati analitici, soprattutto di quelli relativi alla composizione geochimica del materiale piroclastico, non consente di integrare i risultati pubblicati di recente con quelli dei vecchi lavori. a causa dell’esigua disponibilità di osservazioni e delle scarse informazioni sull’inquadramento cronostratigrafico degli orizzonti piroclastici, non è stata ancora definita la tephrostratigrafia regionale per i periodi più antichi del quaternario. la correlazione dei livelli di tephra è invece frequente nel pleistocene superiore, nel quale sono stati individuati alcuni livelli guida per accurate correlazioni stratigrafiche fra successioni marine e continentali. sulla base di nuovi ritrovamenti, la distribuzione areale di alcuni di questi livelli risulta alquanto complessa e comprende la dispersione anche verso i quadranti settentrionali. recenti segnalazioni di tephra di probabile origine italiana in successioni continentali dell’europa centrale aprono la prospettiva di future correlazioni su scala continentale. infine, la corrispondenza tra alcuni segnali geochimici nelle carote di ghiaccio del polo nord ed eruzioni esplosive italiane, tuttora da dimostrare, potrebbe contribuire alla soluzione di importanti quesiti paleoclimatici. keywords: airfall tephra, deep-sea cores, long-distance correlation, quaternary, italy, central mediterranean parole chiave: piroclastiti di caduta, carote di mare profondo, correlazione, quaternario, italia, mediterraneo centrale. il quaternario italian journal of quaternary sciences 1166(1bis), 2003, 3-9 iinnttrroodduuccttiioonn compiling of an exhaustive review on quaternary airfall tephra layers in the central mediterranean area is an arduous task, due to the massive published information pertaining to this topic. suffice it to mention that the first record of the greek term “tephra” (τεφρα) for volcanic ash, dated back to about 360 b.c., concerns just a central mediterranean explosive eruption, whose account was made by aristotle in his book meteorologia. thus, while the modern term “tephrochronology” is less than 60 years old (in thorarinsson, 1974), bibliography on mediterranean tephra spans over two and half millennia of naturalistic and historical literature. even when focusing on the geoscientific bibliography of the last decades, and excluding findings in the proximal setting (< 50 km from source), reports on quaternary volcaniclastic deposits in the central mediterranean sediments are exceptionally numerous. attempts to collect all the published documentation are hampered by the fact that it is dispersed through literature of disciplines as diverse as geoarchaeology, marine micropalaeontology, palynology, stable isotope geochemistry and sedimentology. although publications are so numerous, a part of the published information is not suitable for the development of the quaternary regional tephrostratigraphy. in 4 b. narcisi fact in many cases reports of tephra deposits are not provided with appropriate laboratory data for characterisation of the volcaniclastic material, or fail in reporting details on the used analytical methods. in other cases tephra reworking is either apparent or not properly considered, or the chrono-stratigraphical framework of the tephra and of the tephra-bearing deposits is poorly defined. despite the aforementioned problems and limitations, a few contributions have been published that aim at reviewing the main evidence for quaternary distal tephra layers in the mediterranean region (keller, 1981a; narcisi & vezzoli, 1999) and the italian context (narcisi, 1994) or at collecting systematically data on volcaniclastic deposits in the apennine region (guerrera & veneri, 1989). the present paper represents advancement and updating of the previous reviews carried out by the author. in particular, it is intended to focus on the published tephra information that is of interest for correlation between continental and marine successions. in addition, a few case studies of widely dispersed italian tephra layers are presented and prospects for future research in the field of long-distance correlations are outlined. tthhee pprriinncciippaall aavvaaiillaabbllee ddaattaa marine successions the most significant tephra records of the central mediterranean region, in terms of stratigraphic continuity, ash preservation and time span, are provided by the abyssal sediments. since the late 1940’s several deep-sea investigations have been carried out in the frame of international drilling programs and national enterprises (fig. 1). tephra studies have often been associated with micropalaeontological, sedimentological, stable isotope and magnetic investigations, and radioisotope dating of fossil shells, providing the chronostratigraphic framework of the recorded ash layers. very recently, direct isotopic datation has been attempted on marine ash layers from tyrrhenian core sequences (bogaard et al., 1999; ton-that et al., 2001). due to the difficulty of recovering long records, information on the early pleistocene tephra layers in deep-sea cores is rather sparse. the longest successions, extending back up to miocene, have been retrieved within the deep sea drilling project/ocean drilling program (dsdp/odp), which has dedicated several cruises (i.e. legs 13, 42, 107, 160 and 161) to the central mediterranean area (fig. 1). in addition to the dsdp/odp cores, many shorter, but still important tephra records are available from the tyrrhenian (e.g. paterne et al., 1986; 1988), the adriatic (calanchi et al., 1998), and the ionian seas (keller et al., 1978). from the analysis of the most significant records some general trends can be traced, both in time and in space. the content of volcaniclastic material increases toward the top of the quaternary succession. although each core shows its own tephrostratigraphy reflecting the dominance of the closest tephra source, the data acquired in the recent odp cruises performed in the tyrrhenian sea (mccoy & cornell, 1990; calanchi et al., 1994; bogaard et al., 1999) show that the dominant pliocene and lower pleistocene tephra sources were likely represented by the volcanoes of the pontine islands and the aeolian arc, while in the middle-upper pleistocene and in the holocene aeolian and campanian products were the most frequent. the content of volcaniclastic material in each core depends on the distance of the coring sites from the volcanic sources and on the influence by subaerial (i.e. transport of ash particles by dominant winds) and subaqueous (i.e. reworking before the final deposition) physical agents. indeed, the role of reworking of volcaniclastic sediments in tyrrhenian pelagic records had been emphasized by the earlier studies on cores collected in the abyssal plain (e.g. bartolini et al., 1974). recently, detailed sedimentological and geochemical investigations on odp core sequences have clearly demonstrated that tephra layers originating from ash fallout are rare in the tyrrhenian sea; remobilisation of pyroclastic material by turbidite currents and debris flows is a common phenomenon and it may lead to significant displacement of the tephra from its original stratigraphic position (mccoy & cornell, 1990; calanchi et al., 1994; bogaard et al., 1999). erosion of the thinner layers by sea-bottom currents and bioturbation may represent further factors influencing the record of tephra fall layers. in fig. 2 striking differences can be observed in the frequency of primary tephras, up to one order of magnitude, in late quaternary tyrrhenian cores drilled in close sites with comparable physiographic conditions, as is the case of figure 1 map of the central mediterranean showing the location of quaternary volcanoes (triangles) and seamounts (stars), and of significant deep-sea tephra records. core ket8004 (paterne et al., 1988) and odp site 650 sequence (mccoy & cornell, 1990). these differences may be due to the different sampling resolution or may reflect different constraints applied by the various investigators on the definition of a “non-reworked tephra”. integrating the recent deep-sea findings with evidence from old coring would certainly increase knowledge of stratigraphy and areal distribution of mediterranean ash layers. however, attempts to collate these data are hindered by inconsistent methodological approaches (narcisi & vezzoli, 1999). specifically, the earlier investigations were mainly descriptive; the few geochemical data presented were obtained from wholerock analysis and are clearly influenced by weathering of the volcanic material and contamination by detrital clasts (see for example nesteroff et al., 1973). in the recent tephra studies, bulk sample analysis has been fully replaced by grain-discrete electron microprobe (emp) analysis. due to these differences, few correlations can be attempted between the central mediterranean tephrostratigraphy, resting on emp data, and the well-defined tephra framework of the ionian and levantine seas (keller et al. 1978), which was developed in the late 1970’s on the basis of bulk analysis. reports of findings of tephra in terrestrial exposures of marine sediments are numerous. in southern peninsular italy, some volcaniclastic layers have origin from the nearby vulture volcano (ciaranfi et al., 1996) while others derive from more distant sources (spadea, 1986). in this region, marine ash layers have been 5quaternary distal tephra layers ... extensively used for local correlation purposes (ciaranfi et al., 2001), for reconstruction of the magmatic evolution of the pleistocene volcanism (cello et al., 1983; spadea, 1986), and for inferring relationship between volcanism and tectono-sedimentary processes (cortesogno et al., 1984). some layers have been subject to direct dating (obradovich et al., 1982). petrographic and mineralogical evidence suggests that only few pyroclastic layers are coeval to deposition of bracketing sediments and/or are free from weathering (d’elia et al., 1987). continental successions compared with the deep-sea records, land sequences of tephra are less significant due to intensive erosion and reworking processes acting on the continental realm. in italy, the best continental successions of ash layers are provided by the lacustrine sediments, which have extensively been studied in the last two decades for palaeoclimatic purposes (calanchi et al., 1996; karner et al., 1999; narcisi, 1996; 2002). results worthy to be mentioned have been obtained also on other clastic sequences (narcisi, 1993; bigazzi at al., 1994) and on volcanic palaeosols and related parent materials (frezzotti & narcisi, 1996). cases of direct datation of continental ash layers are common (e.g. bigazzi et al., 1994; 2000; karner et al., 1999). the findings of continental ash layers so far published are almost exclusively located in peninsular italy. to some extent, this distribution reflects proximity of the sites to the explosive volcanic sources; certainly, it is strongly influenced by non-uniform surveying. in fact, entire continental sub-regions that most probably were repeatedly blanketed by ash fallout during the quaternary, are still unexplored from the tephra point of view. similarly, knowledge on land distribution of the identified ash markers is still very patchy as it is defined by casual findings rather than by geographic systematic studies. consequently, an unequivocal and continuous quaternary reference stratigraphy of the distal tephras in the various land regions is still lacking. lloonngg--ddiissttaannccee ccoorrrreellaattiioonn aanndd wwiiddeellyy ddiissppeerrsseedd tteepphhrraa llaayyeerrss in the older quaternary record, correlations of individual tephra layers from marine cores have been achieved in a limited number of cases (cita et al., 1973; bogaard et al., 1999). in theory, regional-scale correlation of tephra in early pleistocene records would be facilitated by the fact that ash layers in this period are not so abundant as in the late quaternary (cita et al., 1973; calanchi et al.., 1994). in practice, identification of older marker tephras is made difficult by the scarce and fragmentary available information, and by uncertainties in the age of the tephra. thus, although chemical and mineralogical features of the 0.6 ma tephra occurring in tuscan continental deposits (nencini, 1983; bigazzi et al., 1994) resemble those of two middle pleistocene ash layers encountered at the tyrrhenian dsdp site 373 (ssp, 1978; keller, 1981a), their correlation cannot be demonstrated because the age of these marine layers is poorly constrained. besides, whilst generic comparison between deep-sea ash layers and volcaniclastic depofigure 2 frequency of recorded primary tephra layers (per 1000 years) in selected late quaternary deep-sea records of the central mediterranean. data of frequency have been calculated from the tephra information reported in cita et al. (1973); keller et al. (1978); keller (1981b); paterne et al. (1988); fontugne et al. (1989); mccoy & cornell (1990); kallel et al. (1997); calanchi et al. (1998). 6 b. narcisi sits in land exposures can be attempted (e.g. calanchi et al., 1994), correlation of specific tephra horizons is more difficult. as an example, on the basis of the sapropel correlation proposed by de kaenel et al. (1999) and of biostratigraphic and palaeomagnetic evidence, the chrono-stratigraphic position of ash turbidite vt-7539/vt7538 from tyrrhenian odp site 974 (bogaard et al., 1999) matches well that of the ash layer m at vrica, southern italy (selli et al., 1977; pasini & colalongo, 2001). according to spadea (1986) and bogaard et al. (1999) both tephras can be classified as high-k rhyolite; close analysis of the data however reveals significant mineralogical and geochemical differences that make correlation between these two layers problematic. while there are few identified early and middle pleistocene marker-tephras (bogaard et al., 1999) and consequently correlation among sites is rarely attained, tephra correlation becomes frequent when late quaternary records are considered (paterne et al., 1986; 1988; narcisi, 1996; calanchi et al., 1998). identification of marker-tephras in this time interval is facilitated by both preservation of deposits and more rigorous age control. main features and chronology of the principal distal tephras of the last 200,000 years are reported elsewhere (narcisi & vezzoli, 1999). recent advances in the knowledge of some late pleistocene tephra markers are worthy to be mentioned in this contribution. layer y-5 – the most widespread tephra layer of the mediterranean related to the eruption of the campanian ignimbrite from the phlegraean fields area – has recently been the subject of radiometric assay (ton-that et al., 2001). ar/ar analysis of sanidine crystals from this layer cored in the tyrrhenian abyssal plain (site ket8004) indicate a most probable age of 41 ka, which is at least 2-3 ka older than estimates on both proximal land exposures (deino et al., 1992; de vivo et al., 2001) and the distal ash in marine and lacustrine cores (thunell et al., 1979; narcisi, 1996; watts et al., 1996). the presence into the dated tephra layer of crystal populations older than 41 ka deserves notice. in marine cores collected not far from ket8004 this campanian marker is represented by a few metres-thick volcaniclastic debris flow comprising vitric particles of heterogeneous origin and also shallow-water mollusc shells (mccoy & cornell, 1990; calanchi et al., 1994; cini castagnoli et al., 1995). however, ton-that et al. (2001) reject a turbiditic origin of the dated tephra and opt for mixing of xenocrysts into the juvenile ash fraction to explain the observed age heterogeneity. currently, the areal distribution of y-5 is defined by some hundred of recovery sites, mainly related to the eastern mediterranean marine setting (fig. 3 of narcisi & vezzoli, 1999); however, a broader, and more complex dispersal is strongly suggested by occurrence in eastern europe of a tephra layer with age and composit ion similar to y-5 (melekestzev et al., 1984). surprisingly, this tephra has not been recovered or identified in the newly studied piston cores drilled in the eastern mediterranean within the known y-5 dispersal area (clift & blusztajn, 1999). given its wide distribution, speculations have been made on the potential interference of the y-5 related eruption with the mediterranean ecological and social system (fedele et al., 2002). increasing attention has recently been deserved to the two marker-tephras that characterise the tephrostratigraphy of the lateglacial period. recent findings of the older marker y-1 (et-1 according to paterne et al., 1988) extend the areal distribution of this tephra far beyond the previously recognised dispersal. in fact, current knowledge indicates that this marker, which is related to the 14 uncal. ka etna multiple eruption that produced the ellittico caldera collapse (coltelli et al., 2000), is distributed towards southeast in the eastern mediterranean and towards north in central italy and adjoining seas (narcisi, 1999a). new occurrences of the younger marker c-2 dated 12.5 uncal. ka and related to the neapolitan yellow tuff from the phlegraean fields area (scarpati et al., 1993), have enabled to trace with more confidence its dispersal area. findings in central italy and in the tyrrhenian and adriatic seas suggest a north-easterly distribution (narcisi, 1999b) and the recent discovery of a lateglacial tephra correlated on geochemical grounds to c-2 in lacustrine records of the northern apennines (davies et al., 2002) and in austria (schmidt et al., 2002) confirms this pattern besides extending significantly dispersal of this tephra. while earlier studies in the mediterranean showed an overall south-easterly ash dispersal ascribed to supposed persistent north-westerly palaeowind directions over the last 200,000 years (mccoy, 1980), the presented examples, together with increasing findings in very remote european sites (see below), suggest that some italian airfall tephra layers might have complex distribution patterns, including also dispersal towards north and northeast. support of evidence of northward aeolian dust transport is provided by recent palynological studies that have pointed out the significance over the western mediterranean of air masses coming from the south, at least during the upper pleistocene and holocene (magri & parra, 2002). previously reconstructed south-easterly distribution of mediterranean tephra might, at least in some cases, be an artefact due to inadequate surveying and non-uniform spatial distribution of sampling sites. ccoonncclluuddiinngg rreemmaarrkkss aanndd pprroossppeeccttss ffoorr ffuuttuurree rreesseeaarrcchh distal tephra layers are powerful tools for unambiguous linking of sites from different environmental settings, and across regions and even continents. the central mediterranean represents one of the most suitable regions of our planet for quaternary tephra investigations, due to the following features (fig. 1): a) abundance of volcanic sources that are quite scattered over the whole region, b) occurrence throughout the quaternary of large-scale explosive volcanism producing significant pyroclastic sheets, c) favourable location of the volcanoes in relation to the land-sea distribution, enabling distal ash fallout to involve simultaneously marine and continental environments, d) marked differences in geochemical signatures from province to province (peccerillo, 2001) that make it possible to discriminate among tephra sources. on the whole, knowledge of quaternary distal tephra in italy has advanced significantly over the last two decades. however, the potential for establishing a detailed tephrostratigraphy is not fully exploited yet. 7quaternary distal tephra layers ... stratigraphical and analytical problems remain in some reports. integration of stratigraphic data with radiometric and palaeomagnetic information is recommended for future work. in addition, more rigorous protocols of characterisation of the identified tephra horizons should be applied, including careful investigation of sedimentary features and detailed microstructural, petrographic and petrochemical studies (westgate & gorton, 1981). in addition to studies on future tephra records, re-examination of ash layers studied in old work might be carried out by means of both routine analysis of grain discrete shards for geochemical characterisation and radioisotopic dating. there is the need to enhance knowledge of dispersal of the identified marker tephras, which is still incomplete and non-uniform in space. as for dispersal in very distal areas, a further hint for future research is suggested by the increasing findings of quaternary tephra likely originated in italy within continental successions of middle and eastern europe (jahns & bogaard, 1998; pyle et al., 1998; pouclet et al., 1999; horvath, 2001; pinti et al., 2001; schmidt et al., 2002). together with earl ier evidence (melekestzev et al., 1984; harkovska et al., 1990), they strongly suggest that some italian ash layers might have enormous areal distribution. future tephra studies could be addressed towards investigation of distal sequences so far considered free of tephra layers. new analytical techniques are available to this purpose that enable identification and characterisation of tephra horizons that are not detectable by visual inspection (e.g. rose et al., 1996). extension of ital ian ash layers to regions external to the mediterranean would open the prospect for precise correlation of palaeoenvironmental records across the european continent. reliable reconstruction of ash dispersal might also contribute to infer the atmospheric circulation patterns over the past. finally, the huge explosive character of the quaternary mediterranean volcanoes suggests that the largest eruptions might have produced significant atmospheric perturbation, even on a global scale. actually, a few sulphate peaks in an ice core record collected in greenland are thought to be related to italian eruptions occurred in historical and prehistoric times (zielinski, 1995; zielinski et al., 1994; 1997). matching of these chemical signals with italian events is still to be demonstrated by the occurrence in the ice of the related volcanic glass. when this relationship will be proved unambiguously, then firm correlation will become possible between sedimentary successions of the central mediterranean and climate records from the north polar region. this will represent a substantial advance towards investigating still open palaeoenvironmental issues as for example the relationship between the north atlantic millennial scale climate variability (i.e. dansgaardoeschger cycles and heinrich events; broecker, 1994) and the mediterranean climate and environment. rreeffeerreenncceess bartolini c., de giuli c. & gianelli g. (1974) turbidites of the southern tyrrhenian sea. bollettino della società geologica italiana, 9933, 3-22. bigazzi g., bonadonna f.p., cioni r., leone g., sbrana a. & zanchetta g. (1994) nuovi dati geochimici, petrografici e geocronologici su alcune cineriti plio-pleistoceniche del lazio e della toscana. memorie descrittive della carta geologica d’italia, 4499, 135-150. bigazzi g., zanchetta g., bonadonna f.p. & leone g. (2000) nuovi dati cronologici sui depositi cineritici del valdarno inferiore (toscana). bollettino della società geologica italiana, 111199, 121-124. bogaard van den p., mocek b. & stavesand m. (1999) chronology and composition of volcaniclastic ash layers in the central tyrrhenian basin (site 974). in r. zahn, m.c. comas & a. klaus (eds.), proceedings of the ocean drilling program, scientific results, 116611, 137-156. broecker w.s. (1994) massive iceberg discharges as triggers for global climate change. nature, 337722, 421-424. calanchi n., cattaneo a., dinelli e., gasparotto g. & lucchini f. (1998) tephra layers in late quaternary sediments of the central adriatic sea. marine geology, 114499, 191-209. calanchi n., dinelli e., lucchini f. & mordenti a. (1996) chemostratigraphy of late quaternary sediments from lake albano and central adriatic sea cores (paliclas project). memorie dell'istituto italiano di idrobiologia, 5555, 247-263. calanchi n., gasparotto g. & romagnoli c. (1994) glass chemistry in volcaniclastic sediments of odp leg 107, site 650, sedimentary sequence: provenance and chronological implications. journal of volcanology and geothermal research, 6600, 59-85. cello g., spadea p., tortorici l. & turco e. (1983) plio-pleistocene volcanoclastic deposits of southern calabria. bollett ino della società geologica italiana, 110022,, 87-93. ciaranfi n., marino m., sabato l., d'alessandro a. & de rosa r. (1996) studio geologico stratigrafico di una successione infra e mesopleistocenica nella parte sudoccidentale della fossa bradanica (montalbano ionico, basilicata). bollettino della società geologica italiana, 111155, 379-391. ciaranfi n., pasini g. & rio d. (eds.) (2001) the meeting on the plio-pleistocene boundary and the lower/middle pleistocene transition: type areas and sections (bari, 25-29 september 2000). memorie di scienze geologiche, 5533, 67-123. clift p. & blusztajn j. (1999) the trace-element characteristics of aegean and aeolian volcanic arc marine tephra. journal of volcanology and geothermal research, 9922, 321-347. cini castagnoli g., albrecht a., beer j., bonino g., shen ch., callegari e., taricco c., dittrichhannen b., kubik p., suter m. & zhu g.m. (1995) evidence for enhanced 10be deposit ion in mediterranean sediments 35 kyr bp. geophysical research letters, 2222, 707-710. cita m.b., chierici m.a., ciampo g., moncharmont zei m., d'onofrio s., ryan w.b.f. & scorziello r. (1973) the quaternary record in the tyrrhenian and ionian basins of the mediterranean sea. in w.b.f. ryan, k.j. hsü et al., initial reports of the deep sea drilling project, 1133,, 1263-1339. coltell i m., del carlo p. & vezzoli l. (2000) 8 b. narcisi stratigraphic constraints for explosive activity in the past 100 ka at etna volcano, italy. international journal of earth sciences, 8899, 665-677. cortesogno l., guerrera f., franchi r., vannucci r. & vannucci s. (1984) le successioni “tripolacee” plio-quaternarie del versante ionico dell’appennino: una possibile interpretazione dei processi vulcano-tettonici e sedimentari. rendiconti della società italiana di mineralogia e petrologia, 3399,, 535-554. davies s.m., branch n.p., lowe j.j. & turney c.s.m. (2002) towards a european tephrochronological framework for termination 1 and the early holocene. philosophical transactions of the royal society of london, aa 336600, 767-802. de kaenel e., siesser w.g. & murat a. (1999) pleistocene calcareous nannofossil biostratigraphy and the western mediterranean sapropels, sites 974 to 977 and 979. in r. zahn, m.c. comas & a. klaus (eds.), proceedings of the ocean drilling program, scientific results, 116611, 159-183. d’elia g., di girolamo p. & guida m. (1987) geological and petrological characters of some quaternary calcalkaline tuff i tes of cilento (southern italy). bollettino della società geologica italiana, 110066, 699-716. deino, a., curtis, g. & rosi m. (1992) 40ar/39ar dating of campanian ignimbrite, campanian region, italy. 29th international geological congress, kyoto, abstracts, 33, 633. de vivo b., rolandi g., gans p.b., calvert a., bohrson w.a., spera f.j. & belkin h.e. (2001) new constraints on the pyroclastic eruptive history of the campanian volcanic plain (italy). mineralogy and petrology, 7733,, 47-65. fedele f.g., giaccio b., isaia r. & orsi g. (2002) ecosystem impact of the campanian ignimbrite eruption in late pleistocene europe. quaternary research, 5577, 420-424. fontugne m.r., paterne m., calvert s.e., murat a., guichard f. & arnold m. (1989) adriatic deep water formation during the holocene: implication for the reoxygenation of the deep eastern mediterranean sea. paleoceanography, 44,, 199-206. frezzotti m. & narcisi b. (1996) late quaternary tephra-derived paleosols in central italy's carbonate apennine range: stratigraphical and paleoclimatological implications. quaternary international, 3344-3366,, 147-153. guerrera f. & veneri f. (1989) evidenze di attività vulcanica nei sedimenti neogenici e pleistocenici dell’appennino: stato delle conoscenze. bollettino della società geologica italiana, 10088, 121-160. harkovska a.v., zlatkova m.j., chochov s.d. & vergilova z.i. (1990) campanian area tephra on the territory of bulgaria. iavcei international volcanological congress, mainz, abstracts. horváth e. (2001) marker horizons in the loesses of the carpathian basin. quaternary international, 7766//7777, 157-163. jahns s. & bogaard van den c. (1998) new palynological and tephrostratigraphical investigations of two salt lagoons on the island of mljet, south dalmatia, croatia. vegetation history and archaeobotany, 77, 219-234. kallel n., paterne m., labeyrie l., duplessy j.-c. & arnold m. (1997) temperature and salinity records of the tyrrhenian sea during the last 18,000 years. palaeogeography, palaeoclimatology, palaeoecology, 113355, 97-108. karner d.b., juvigné e., brancaccio l., cinque a., russo ermolli e., santangelo n., bernasconi s. & lirer l. (1999) a potential early middle pleistocene tephrostratotype for the mediterranean basin: the vallo di diano, campania, italy. global and planetary change, 2211, 1-15. keller j. (1981a) quaternary tephrochronology in the mediterranean region. in s. self & r.s.j. sparks (eds.), tephra studies. d. reidel publishing company, dordrecht, 227-244. keller j. (1981b) alkalibasalts from the tyrrhenian sea basin: magmatic and geodynamic significance. bulletin volcanologique, 4444,, 327-337. keller j., ryan w.b.f., ninkovich d. & altherr r. (1978) explosive volcanic activity in the mediterranean over the past 200,000 yr as recorded in deep-sea sediments. geological society of america bulletin, 8899, 591-604. magri d. & parra i. (2002) late quaternary western mediterranean pollen records and african winds. earth and planetary science letters, 220000, 401-408. melekestzev i.v., kirianov v.yu. & praslov n.d. (1984) catastrophic eruption in the phlegrean fields region (italy) possible source for a volcanic ash in late pleistocene sediments of the european part of the ussr. (in russian). vulcanologia i seismologia, 33, 35-44. mccoy f.w. (1980) the upper thera (minoan) ash in deep-sea sediments: distribution and comparison with other ash layers. in c. dumas (ed.), thera and the aegean world. proceedings 2° international scientific congress on the volcano of thera, greece, 22,, 57-78. mccoy f.w. & cornell w. (1990) volcanoclastic sediments in the tyrrhenian basin. in k.a. kastens, j. mascle et al.: proceedings of the ocean drilling program, scientific results, 110077, 291-305. narcisi b. (1993) segnalazione di un livello piroclastico di provenienza etnea nell'area del fucino, italia centrale. il quaternario, 66, 87-92. narcisi b. (1994) tefracronologia in aree non vulcaniche: principi, metodi di indagine e stato dell'arte nel contesto italiano. il quaternario, 77, 545-554. narcisi b. (1996) tephrochronology of a late quaternary lacustrine record from the monticchio maar (vulture volcano, southern italy). quaternary science reviews, 1155, 155-165. narcisi b. (1999a) nuovi ritrovamenti del tephra tardiglaciale etneo in italia centrale. il quaternario, 1122, 69-78. narcisi b. (1999b) neapolitan yellow tuff tephra in the lacustrine sediments of the valle di castiglione crater (alban hills). acta vulcanologica, 1111, 265269. narcisi b. (2002) tephrostratigraphy of the late quaternary lacustrine sediments of lago di pergusa (central sicily). bollettino della società geologica italiana, 112211,, 211-219. narcisi b. & vezzoli l. (1999) quaternary stratigraphy of distal tephra layers in the mediterranean an overview. global and planetary change, 2211, 31-50. nencini c. (1983) il passaggio plio-pleistocene e i sedimenti pliocenici e pleistocenici delle colline di monte castello (pisa). bollettino della società geologica italiana, 110022, 391-398. nesteroff w.d., wezel f.c. & pautot g. (1973) summary of lithostratigraphic findings and problems. in w.b.f. ryan, k.j. hsü et al., initial reports of the deep sea drilling project, 1133, 1021-1040. obradovich j.d., naeser c.w., izett g.a., pasini g., & bigazzi g. (1982) age constraints on the proposed plio-pleistocene boundary stratotype at vrica, italy. nature, 229988, 55-59. pasini g. & colalongo m.l. (2001) the pliocene/ pleistocene boundary-stratotype and the proposed santernian/emilian boundary-stratotype (lower pleistocene) at the vrica section (calabria, southern italy). in n. ciaranfi, g. pasini & d. rio (eds.), the meeting on the plio-pleistocene boundary and the lower/middle pleistocene transition: type areas and sections (bari, 25-29 september 2000). memorie di scienze geologiche, 5533,, 113123. paterne m., guichard f. & labeyrie j. (1988) explosive activity of the south italian volcanoes during the past 80,000 years as determined by marine tephrochronology. journal of volcanology and geothermal research, 3344, 153-172. paterne m., guichard f., labeyrie j., gillot p.y. & duplessy j.c. (1986) tyrrhenian sea tephrochronology of the oxygen isotope record for the past 60,000 years. marine geology, 7722, 259-285. peccerillo a. (2001) geochemistry and petrogenesis of quaternary magmatism in central-southern italy. geochemistry international, 3399, 521-535. pinti d.l., quidelleur x., chiesa s., ravazzi c. & gillot p.-y. (2001) k-ar dating of an early middle pleistocene distal tephra in the interglacial varved succession of piànico-sèllere (southern alps, italy). earth and planetary science letters, 118888, 1-7. pouclet a., horvath e., gabris g. & juvigné e. (1999) the bag tephra, a widespread tephrochronological marker in middle europe: chemical and mineralogical investigations. bulletin of volcanology, 6600,, 265-272. pyle d.m., andel van t.h., paschos p. & bogaard van den p. (1998) an exceptionally thick middle pleistocene tephra layer from epirus, greece. quaternary research, 4499,, 280-286. rose n.l., golding p.n.e. & battarbee r.w. (1996) selective concentration and enumeration of tephra shards from lake sediments cores. the holocene, 66, 243-246. scarpati c., cole p. & perrotta a. (1993) the neapolitan yellow tuff a large volume multiphase eruption from campi flegrei, southern italy. bulletin of volcanology, 5555, 343-356. schmidt r., bogaard van den c., merkt j. & müller j. (2002) a new lateglacial chronostratigraphic tephra marker for the south-eastern alps: the neapolitan yellow tuff (nyt) in längsee (austria) in the context of a regional biostratigraphy and palaeoclimate. quaternary international, 8888, 45-56. selli r., accorsi c.a., bandini mazzanti m., bertolani marchetti d., bigazzi g., bonadonna f.p., borsetti a.m., cati f., colalongo m.l., d’onofrio s., landini w., menesini e., mezzetti r., pasini g., savelli c. & tampieri r. (1977) the vrica section (calabria, italy). a potential neogene-quaternary boundary stratotype. giornale di geologia, 4422, 181-204. shipboard scientific party (ssp) (1978) site 373: tyrrhenian basin. in k.j. hsü, l. montadert et al., initial reports of the deep sea drilling project, 4422, 151-163. spadea p. (1986) volcanogenic deposits in fossa bradanica (southern italy): records of calc-alkaline and alkaline volcanism during the pliocene and pleistocene in the mediterranean. neues jahrbuch fur mineralogie abh., 115533,, 217-244. ton-that t., singer b. & paterne m. (2001) 40ar/39ar dating of latest pleistocene (41 ka) marine tephra in the mediterranean sea: implications for global climate records. earth and planetary science letters, 118844, 645-658. thorarinsson s. (1974) the terms tephra and tephrochronology. in j.a. westgate & c.m. gold (eds.), world bibliography and index of quaternary tephrochronology, xvii-xviii. thunell r., federman a., sparks s. & williams d. (1979) the age, origin, and volcanological significance of the y-5 ash layer in the mediterranean. quaternary research, 1122, 241-253. watt, w.a., allen j.r.m. & huntley b. (1996) vegetation history and palaeoclimate of the last glacial period at lago grande di monticchio, southern italy. quaternary science reviews, 1155, 133-153. westgate j.a. & gorton m.p. (1981) correlation techniques in tephra studies. in self s. & sparks r.s.j. (eds.), tephra studies. d. reidel publishing company, dordrecht, 73-94. zielinski g.a. (1995) stratospheric loading and optical depth estimates of explosive volcanism over the last 2100 years derived from the greenland ice sheet project 2 ice core. journal of geophysical research, 110000,, d10, 20937-20955. zielinski g.a., mayewski p.a., meeker l.d., grönvold k., germani m.s., whitlow s., twickler m.s. & taylor k. (1997) volcanic aerosol records and tephrochronology of the summit, greenland, ice cores. journal of geophysical research, 110022, c12, 26625-26640. zielinski g.a., mayewski p.a., meeker l.d. whitlow s., twickler m.s., morrison m., meese d.a., gow a.j. & alley r.b. (1994) record of volcanism since 7000 b.c. from the gisp2 greenland ice core and implications for the volcano-climate system. science, 226644, 948-952. 9quaternary distal tephra layers ... amq abs vallè et al palcom 165-168.pub available online http://amq.aiqua.it issn (online): 2279-7335 alpine and mediterranean quaternary, vol. 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 165 168 testing pollen-climate models over the last 200 years in n-italy using instrumental data francesca vallè 1, michele brunetti 2, roberta pini 3, valter maggi 1, cesare ravazzi 3 1 dept. of environmental and earth sciences, university of milano bicocca, milano, italy 2 institute of atmospheric sciences and climate, cnr, bologna, italy 3 idpa cnr, research group on vegetation, climate and human stratigraphy, laboratory of palynology and palaeoecology, milano, italy corresponding author: f. vallè <francesca.valle@unimib.it> abstract: we evaluated pollen-climate models developed for past temperature reconstruction in northern italy by comparing polleninferred temperature series with site-specific instrumental series in two records covering the last 200 years and provided with a pollen sample resolution of 5/9 years. moderate to good correlation is found. we discuss the methodological approach and the possible influence of human activities in the pollen-inferred reconstructions. keywords: north italy, pollen data, instrumental temperature, pollen-climate models, quantitative summer temperature, last 200 years 1. introduction during the last 50 years, different procedures were developed to quantitatively estimate past environmental and climate variables from stratigraphical microfossil assemblages, including pollen data (brewer et al., 2007, juggins & birks, 2012). the validation of pollen-climate models and the climate reconstructions obtained from palynological data for intervals older than the instrumental data are only possible using statistical tests and procedures (e.g. juggins & birks, 2012 and reference therein). so far, only one paper presented climate reconstructions based on pollen spectra and their validation against instrumental data (st. jacques et al., 2015). no attempts have been done in italy. in this paper we present the first results concerning the development and testing of pollen-climate models to reconstruct summer temperatures over the last 200 years in northern italy. we use two previously published highresolution pollen records, discuss methodological issues and validate the pollen-inferred reconstructions based on the direct comparison with instrumental data obtained for the same sites. 2. materials and methods 2.1 study sites and pollen data the two study sites are located at different altitudes and are characterized by different mean climatological conditions (fig. 1). lago grande di avigliana (353 m a.s.l.) lies at the foothills of the western alps: mean july temperature (reference period 1961-1990) is around 22° c. lago di lavarone (1115 m a.s.l.) is located in the prealpine region: mean july temperature is around 16°c. sediment cores covering part of the late glacial and the whole holocene were extracted from both lakes and studied for their pollen content to reconstruct the vegetation history, also including land-use changes in the two pollen source areas. pollen records covering the last 200 years from lago grande di avigliana and lago di lavarone are presented respectively in finsinger et al. (2006) and in arpenti & filippi (2007). the sequence from lago grande di avigliana has a good chronological control, based on varves counting, 210pb and 137cs dates: mean temporal resolution of the pollen record is fig. 1 map showing the location of the two study sites on t july climatology (1961-1990), adapted from brunetti et al. (2014). lga: lago grande di avigliana (353 m a.s.l.) at the foothills of the western alps and lav: lago di lavarone (1115 m a.s.l.) in the eastern side of the pre-alpine region. https://doi.org/10.26382/aiqua.2018.aiquaconference ~4 years for the last 200 years. a good age control is available also for the lago di lavarone sequence: its pollen record has a mean sample resolution of ~9 years for the last 200 years with higher temporal resolution after ~1900 ad. 2.2 site-specific temperature series for the last 200 years to overcome the lack of representativeness at the local scale of the commonly-used global climatological datasets, monthly instrumental temperature series have been reconstructed for lago grande di avigliana (18332010) and lago di lavarone (1807-2010). series were obtained by means of the anomaly method (new et al., 2000; mitchell & jones, 2005), as described in brunetti et al. (2012), and benefit from the availability of several long instrumental temporal series for northern italy (brunetti et al., 2006). specifically, the procedure consists in the independent reconstruction of the climatological normals over a given reference period (i.e. the climatologies) and the anomalies (i.e. the departures from the climatologies): the former, characterized by remarkable spatial gradients, require a high spatial density of stations (even if with a limited temporal coverage) and a sophisticated interpolation procedure (brunetti et al., 2014; crespi et al., 2018) to be reconstructed. anomalies are more coherent being linked to climate variability and, therefore, a low spatial density is enough but long temporal coverage and accurate homogenization (i.e. the procedure that removes the non-climatic signals introduced by stations and instruments relocation, changes in measurement practices and so on) is mandatory. finally, absolute values of temperature monthly series for each site can be obtained by the superimposition of the two fields. the summer temperature series have been calculated by averaging june, july and august series. in order to highlight the temperature trends and to facilitate the comparison and the correlation between the instrumental records and the pollen-inferred reconstructions, the instrumental summer temperature series were smoothed with loess regression (for lga span=0.05, for lav span=0.1) following the pollen resolution. past statistical software version 3.3 (hammer et al., 2001) was used. 2.3 pollen-based quantitative temperature reconstructions a three-steps approach (juggins and birks, 2012) was applied to obtain quantitative estimates of summer temperature. as a first step we developed an italian modern pollen-climate calibration set that could cover the summer temperature gradients displayed during the last two centuries. 265 modern pollen samples have been selected from the european modern pollen database (empd, davis et al., 2013); each sampling location was associated to site-specific instrumental temperature data, reconstructed for the period 1951-2000 following the same procedure described above. pollen taxonomy has been harmonized, both in the calibration set samples and in the fossil records. the specific training set is the base for the second step, i.e. modeling the modern pollen-temperature relationship and create the 166 fig. 2 a) comparison between instrumental t summer series (grey curves) and the pollen-inferred t summer reconstructions (red dotted curves) obtained for lga and lav with the wa method. the instrumental summer t series were smoothed with loess regression (for lga span=0.05, for lav span=0.1) according to the pollen resolution (black curves). coefficient of determination between the two series are also shown. b) percentages of two anthropogenic pollen taxa, cannabaceae from lga and ostrya from lav, which might influence the pollen-inferred temperature reconstructions. vallè f. et al 167 transfer functions by means of two numerical methods: the weighted-averaging (wa) regression and calibration (ter braak & barendregt, 1986; juggins and birks, 2012 and reference therein) and the weighted-averaging partial least square regression and calibration (wapls) (ter braak & juggins, 1993). we finally applied the transfer functions to fossil pollen records to estimate the summer temperature values for the last 200 years. before applying the transfer functions to the fossil records the statistical performances of the developed models were checked in cross-validation. the goodness of the calibration set in terms of availability of modern analogues for each fossil pollen sample was also evaluated using the modern analogue technique (mat) and its diagnostics. the “real” validation of the pollen-inferred reconstructions has been obtained by comparing the pollen-based temperature series with the instrumental data. the development of wa and wapls models, the evaluation of their performances, the temperature reconstructions and the mat diagnostics were carried out using r software (r core team, 2017) and the rioja, r package (juggins, 2017). 3. results pollen-inferred summer temperature reconstructions obtained for lago grande di avigliana and lago di lavarone are shown together with the instrumental series (fig. 2). wa pollen-inferred summer temperature values obtained for lga are almost constantly underestimated if compared to the instrumental series. they are instead slightly overestimated for lav but, considering the sample specific errors (not shown in fig. 2), they include the instrumental values. despite the shift in the absolute values at lga, the decadal variability and the long-term trend in summer temperature instrumental series are also detectable in the pollen-inferred reconstructions, and this is true for both sites. interestingly, the lga pollen-inferred summer t reconstruction recognizes the warmer interval recorded between 1940 and 1950 ad. the direct comparison of the wa pollen-inferred summer temperatures with the instrumental series yielded a moderate correlation for lga (r2=0.41) and a good correlation for lav (r2=0.7). 4. discussion and conclusion during the last two centuries mean air temperature in italy shows an increasing trend of 1°c per century with an intensification occurred in the last decades (brunetti et al. 2006, 2013). beside this century-long temperature increase, negative trends over shorter periods have been observed at the beginning of the 19th century and between 1950-1970 ad (brunetti et al. 2006, 2013). pollen-inferred summer temperature reconstructions capture the general warming of the last centuries. fig. 2 also presents the pollen percentages of two important pollen-productors which were affected by human land use changes, i.e. cannabaceae from the pollen record of lago grande di avigliana (finsinger et al., 2006) and ostrya from the pollen record of lago di lavarone. cannabis sativa was cultivated in northern piedmont in the 19th century until ~1950 ad (finsinger et al. 2006 and reference therein). whether this taxon is included or not in the pollen sum used for the temperature reconstructions, it influences the reconstructed absolute values. this issue needs to be carefully considered because this pollen taxon is not well represented in the used calibration set. concerning ostrya, this species is today the main component of forest vegetation in the pollen source area of lago di lavarone. its expansion started around 1965 ad, favoured by decreased human activities in the area (arpenti and filippi, 2005). we are aware that wa methods are able to solve the “non-analogues” problems but suffer from the “edge effects” (juggins & birks, 2012 and reference therein). being lago grande di avigliana summer temperature values at the end of the calibration set summer temperature gradient, the constant underestimation of the lga pollen-inferred summer temperature might be due to this reason. this rigid shift in absolute values (which does not affect the long-term variability) is reduced by using wapls model (not shown in fig. 2). our results show that pollen records obtained from lacustrine sediment cores can be used to obtain polleninferred reconstructions with trends comparable to instrumental data over the last 200 years, provided that: 1) pollen records have a robust age control and high sample resolution (ideally less than a decade), 2) proper calibration sets and adequate numerical techniques are used to develop pollen-climate models and transfer functions to be applied to fossil pollen records. the human activities and their effects in the pollen relative abundances must be considered and evaluated in the process of taxa selection before applying quantitative methods. a further perspective after the calibration of pollenbased reconstructions with instrumental data will involve the comparison between the pollen-inferred summer temperature reconstructions and the dendrochronological-based summer temperature reconstructions for common temporal intervals in the alpine region. if the climate signals from both proxies are comparable, those proxies might be combined to build an integrate multiproxy temperature reconstruction for northern italy. acknowledgements this research is funded by the cnr-dta project of interest nextdata, a national system for the retrieval, storage, access and diffusion of environmental and climate data from mountain and marine areas (www.nextdataproject.it). pollen data for lago grande di avigliana were extracted from the european pollen database (epd, http://www.europeanpollendatabase.net/). the work by data contributors and the epd community is gratefully acknowledged. references arpenti e., filippi m.l. (2007) evoluzione della vegetazione nei pressi del lago di lavarone (tn) negli ultimi 2200 anni. studi trent. sci. nat., acta geol., 82, 317-324. pollen-climate models over the last 200 years in n-italy brewer s., guiot j., barboni d. (2007) pollen data as climate proxies. in: elias sa (ed) encyclopedia of quaternary science, (4). elsevier, new york, 24982510. brunetti m., maugeri m., monti f., nanni t. (2006) temperature and precipitation variability in italy in the last two centuries from homogenized instrumental time series. international journal of climatology, 26, 345-381. brunetti m., lentini g., maugeri m., nanni t., simolo c., spinoni j. (2012) projecting north eastern italy temperature and precipitation secular records onto a high resolution grid. physics and chemistry of the earth, 40-41, 9-22. brunetti m., maugeri m., nanni t., simolo c. (2013) variazioni climatiche in italia negli ultimi due secoli. in: il mutamento climatico. processi naturali e intervento umano. bologna, ed. il mulino, pp. 357. brunetti m., maugeri m., nanni t., simolo c., spinoni j. (2014) high-resolution temperature climatology for italy: interpolation method intercomparison. international journal of climatology, 34, 12781296. crespi a., brunetti m., lentini g., maugeri m. (2018) 1961-1990 high-resolution monthly precipitation climatologies for italy. international journal of climatology, 38, 878-895, doi: 10.1002/joc.5217. davis b.a.s., zanon m., collins m., mauri a., bakker j., barboni d., barthelmes a., beaudouin c., birks h.j.b., bjune a.e. et al. (2013) the european modern pollen database (empd) project. vegetation history and archaeobotany, 22, 521-530. finsinger, w., bigler c., krähenbühl u., lotter af., ammann b. (2006) human impacts and eutrophication patterns during the past ~200 years at lago grande di avigliana (n. italy). journal of paleolimnology, 36, 55-67. hammer, ø., harper, d.a.t., ryan, p.d. (2001) past: paleontological statistics software package for education and data analysis. palaeontologia electronica 4(1), 9. juggins s., birks h.j.b. (2012) quantitative environmental reconstructions from biological data. in (birks et al., eds.): tracking environmental change using lake sediments. data handling and numerical techniques. chapter 14, 431-494. springer. juggins s. (2017) rioja: analysis of quaternary science data, r package version (0.9-15.1) (http:// cran.r-project.org/package=rioja). mitchell t.d., jones p.d. (2005) an improved method of constructing a database of monthly climate observations and associated high-resolution grids. international journal of climatology, 25(6), 693712. new m., hulme m., jones p. (2000) representing twentieth-century space-time climate variability. part ii: development of 1901–96 monthly grids of terrestrial surface climate. journal of climate, 13, 2217-2238. r core team (2017) r: a language and environment for statistical computing. r foundation for statistical computing, vienna, austria. url https:// www.r-project.org/. st. jacques j.m., cumming b.f., sauchyn d.j., smol j.p. (2015) the bias and signal attenuation present in conventional pollen-based climate reconstructions as assessed by early climate data from minnesota, usa. plos one 10(1), e0113806. doi:10.1371/journal.pone.0113806. ter braak, c.j.f., barendregt, l.g. (1986) weighted averaging of species indicator values: its efficiency in environmental calibration. mathematical biosciences, 78, 57-72. ter braak c.j.f., juggins s. (1993) weighted averaging partial least squares regression (wa-pls): an improved method for reconstructing environmental variables from species assemblages. hydrobiologia, 269/270, (1), 485-502. 168 vallè f. et al ms. received: may 7, 2018 final text received: may 16, 2018 imp. bertacchini-cenciaioli uunnoo ssgguuaarrddoo ssuullllaa cciittttàà rroommaannaa ddii ooccrriiccuulluumm ((uummbbrriiaa,, iittaallyy)) mmiilleennaa bbeerrttaacccchhiinnii11 && lluuaannaa cceenncciiaaiioollii22 1d.to di scienze della terra, università di modena e reggio emilia, modena, italy 2soprintendenza per i beni archeologici dell’umbria, perugia, italy riassunto otricoli è un centro abitato nel sud dell’umbria, situato in un territorio limitato ad est dai rilievi della catena appenninica e ad ovest dal ”fiume di roma”, il tevere. arroccato su una rupe, domina dall’alto le vestigia di quella che fu, in epoca romana, otricoli “apud tiberim” (al tevere) nota come ocriculum. ocriculum sorse e si sviluppò in età augustea, tra il i sec. a.c. e il ii sec. d.c, in una zona pianeggiante e degradante verso il tevere e divenne presto un fiorente centro commerciale. la città crebbe difesa naturalmente da due contrafforti in tufo, sopra e a ridosso dei quali furono costruiti importanti edifici e ville patrizie. nell’area affiora una successione sedimentaria del pliocene sup.-pleistocene inf., medio di ambiente marino passante ad ambiente fluviale e una copertura, variamente estesa, di rocce piroclastiche del pleistocene medio prodotte dal vulcano di vico. tra la fine del vi e il vii sec. d.c. l’azione sinergica di fattori naturali e antropici (caratteristiche litologiche e morfologiche, deterioramento climatico e situazione di degrado conseguente alla crisi dell’impero romano) costrinse gli abitanti ad abbandonare l’antica città di ocriculum. abstract otricoli is a village located in the south of the umbria region (central italy). it is perched in a territory limited on the eastern side by the apennines chain and the west by the tiber river. from the top of a hill otricoli dominates the ruins of the roman village of ocriculum. ocriculum was founded in the 1st century b.c. and developed during the 2nd century a.d. it was placed in a flatten area declining towards the tiber river and soon it became a prosperous commercial centre. marine sediments of the late pliocene-early pleistocene and fluvial sediments of the early-middle pleistocene covered by middle-late pleistocene pyroclastic rocks cropping out in the area. in the early times of the roman village two barrier-walls were built to widen the plain area. the romans filled in and levelled the valley at various times in order to obtain a wide plain area while the substructures were built as foundations of public buildings and to stabilise the slope under the forum. in the first phase a barrier-wall was built in the lower part of the stream (close to the r. tiber). consequently the san vittore stream began wandering and accumulating sediments. later a second barrier-wall had to be built, on the upper side of the stream, beside the baths. the san vittore stream was also channelled between the two barrier-walls for about 300 m in order to better control the flood plain. natural factors and human activities caused ocriculum’s deterioration that forced the inhabitants to abandon the town in the period between the end of the 6th and 7th centuries a.d., during the climatic minimum of the early middle ages. the cold, wet climatic conditions certainly facilitated the decline of the territory, already worsened by the consequences of the fall of the roman empire. the transfer of the inhabitants of ocriculum to the upper village is not clearly described in historical documents, although it is certain that there was no life in this roman village after the 7th century a.d parole chiave: città romana, sedimenti marini, rocce piroclastiche, caratteristiche litologiche, morfologiche, deterioramento climatico. keywords: roman village, marine sediments, pyroclastic rocks, natural factors, deterioration, climatic minimum. il quaternario italian journal of quaternary sciences 1166(2), 2003, 207-216 11.. iinnttrroodduuzziioonnee il territorio di otricoli, in provincia di terni, al confine tra l’umbria e il lazio, è limitato ad oriente dai rilievi montuosi dei monti di amelia e narni e ad occidente dal “fiume di roma”: il tevere (fig. 1). la radice greca del nome ocris (monte) suggerisce la posizione rilevata e arroccata su una rupe del paese, all’ombra del quale si ergono le vestigia di quella che fu, in epoca romana, otricoli “apud tiberim” (al tevere) nota come ocriculum. le fonti storiche riportano come ocrea il nome del primo insediamento sorto nella zona più rilevata, situato al confine tra il territorio umbro e quello sabino. la posizione dominante che ocrea occupava sull’alveo del tevere era accentuata ancor più dalla presenza di un castello (martinori, 1929), del quale oggi non rimangono tracce. ocriculum sorse in età augustea nel i sec. a.c. e si sviluppò nel ii sec. d.c, in una zona pianeggiante e degradante verso il tevere, occupando un’area di 36 ettari circa. in periodo tardo imperiale il nome cambiò in utriculum da cui derivò la forma medievale utricoli. l’insediamento di epoca romana divenne presto un nodo strategico tra varie vie di comunicazione e un fiorente centro commerciale. attraversato dalla via flaminia, ocriculum costituiva una sosta importante nel lungo collegamento tra roma e ariminum (rimini); mentre l’approdo di ocriculum sul tevere, noto come “porto dell’olio”, rappresentava uno dei principali porti fluviali 208 m. bertacchini & l. cenciaioli tiberini. le cause che portarono gli abitanti di ocriculum ad abbandonare l’area posta a quota inferiore e a fare ritorno alla “ocris” sono controverse. secondo pietrangeli (1978) l’abbandono avvenne nell’alto medioevo, forse nella seconda metà del vii sec., per “sfuggire all’aria malsana della zona soggetta a inondazioni e a cambiamenti del letto del tevere”. secondo bonomi ponzi (1995) lo spostamento verso l’altura sarebbe avvenuto tra viii e ix sec., per cause legate non tanto ad un diffuso senso di insicurezza quanto allo stato di impaludamento e di conseguente incuria del territorio (scomparsa di cariche statali quali curatores viarum e riparum). tali condizioni di degrado accentuarono lo stato di distruzione in cui l’umbria peraltro già si trovava, perché colpita da carestie e pestilenze nel v-vi sec. d.c. e soggetta a devastazioni e saccheggi durante le invasioni barbariche. in particolare, nel 772, desiderio re dei longobardi, dirigendosi verso roma, espugnò ocriculum, portando devastazione all’abitato e causando l’abbandono dell’antico tracciato della via flaminia che fu spostata più verso monte (martinori, 1929). 22.. ddaattii aarrcchheeoollooggiiccii 22..11 llaa cciittttàà i resti più antichi che rimangono dell’abitato “di monte” sono rappresentati da tratti di mura risalenti alla fine del iv sec. a.c. primi decenni del iii sec. a.c., rimasti inglobati nelle mura castellane dell’attuale otricoli. inoltre, nelle immediate vicinanze del sito archeologico di ocriculum, in località querciacupa e nel podere lupacchini, sono state individuate alcune cavità artificiali utilizzate come tombe, ricavate sul fronte di affioramento dei rilievi di tufo; altre sepolture sono del tipo a fossa. queste necropoli arcaiche, attribuibili al viivi sec. a.c., attestano nell’area, insieme a materiali frammentari, la presenza di insediamenti appartenenti alla prima età del ferro (cenciaioli, 2001). un’altra tomba arcaica di pregevole architettura è stata rinvenuta all’ inizio dell ’anno 2003 da cenciaioli in località querciacupa, sempre nel coronamento esterno del tavolato in tufo; sono attualmente in corso studi di carattere archeologico e geologico per caratterizzare e documentare l’area di rinvenimento. tra i resti di età arcaica rinvenuti nel pod. civitelle è presente una terracotta architettonica con fregio figurato in rilievo che rappresenta una teoria di armati. dall’area centrale della città antica provengono inoltre sporadiche terrecotte architettoniche, tra le quali un busto di figura maschile nudo (fig. 2) databile tra il iv e il iii sec. a.c. (cenciaioli, 2001), che attestano uno sviluppo della città in età classica ed ellenistica. dal i sec. a.c. in poi la storia di ocriculum si può leggere attraverso i monumenti, molti dei quali costruiti tra il i sec. a.c. ed il i sec. d.c. in opera reticolata (tecnica muraria del periodo repubblicano) e come raccolti intorno al torrente s. vittore. le terme furono costruite nel ii sec. d.c. e sono, per ovvie ragioni, il monumento più vicino al corso d’acqua; mentre il teatro, le grandi e le piccole sostruzioni, alle spalle delle terme, si affacciano ad una cinquantina di metri dall’alveo. la città doveva essere ricca di edifici splendidamente decorati e il suo centro, dove sorgevano la basilica e il foro, dei quali si è persa ogni traccia, era probabilmente posto nel pod. civitelle (cenciaioli, 2002b). gran parte delle fabbriche cittadine erano costruite in tufo e alcune strutture come l’anfiteatro (fig. 3) e il teatro erano, in parte, scavate direttamente nel tavolato tufaceo. 22..22 llaa vviiaa ffllaammiinniiaa la città era attraversata dalla via flaminia che, fiancheggiata da querce e monumenti funerari (cenfig. 1 ubicazione dell’antica città romana di ocriculum e dell’attuale centro di otricoli. location of the roman town of ocriculum and the present-day town of otricoli. fig. 2 terracotta raffigurante figura maschile (da cenciaioli, 2001). terracotta of male figure (by cenciaioli, 2001). ciaioli, 2000), si snodava tra la dolce morfologia dell’area, assecondando ondulazioni e sinuosità del rilievo. la via consolare, realizzata dal console c. flaminio nel 220-219 a.c., oltrepassato il tevere presso la località pile di augusto, entrava in umbria circa un chilometro a sud di ocriculum, dopo un percorso di 44 209uno sguardo sulla città romana di ocriculum miglia da roma. una volta superato il castello delle formiche, attraversava il tavolato di tufo meridionale con un percorso rettilineo, circa parallelo a quello dell’attuale via flaminia, mantenendosi sempre intorno a 94 m di quota, e raggiungeva le località pianacci ed essiccatoio (messineo, 1993). lungo questo tratto, accompagnato da numerosi monumenti funerari, il tracciato appare ora coperto da un manto di ciottoli arrotondati e appiattiti (usati come fondo stradale) che scompaiono a pochi metri ai lati della strada. la “via publica” continuava fiancheggiando l’anfiteatro, guadava il torrente s. vittore in corrispondenza del monumento funerario a torre (fig. 4) e giungeva finalmente verso l’area urbana di ocriculum. è all’ingresso della città che uno scavo condotto dalla soprintendenza per i beni archeologici dell’umbria ha rinvenuto un tratto della via flaminia basolato con lava leucitica (fig. 5), delimitato da una fonte pubblica e da un monumento funerario rotondo a tamburo, rivestito di blocchi di travertino (cenciaioli, 2000, 2002a, b). la strada doveva poi proseguire verso il foro, seguendo un percorso che saliva prima blandamente alle spalle delle piccole sostruzioni, quindi più ripidamente verso la chiesa di s. fulgenzio o del buon consiglio f ino a raggiungere l ’abitato di monte (cenciaioli, 2000; 2002a). a testimonianza di questo percorso, nel versante sotto di esso e rivolto a nord, nei pod. cisterna e carpineto, si rinvengono frammenti e blocchi di lava leucitica sino a veri e propri basoli, che un tempo dovevano formare il basolato stradale. 22..33 ggllii ssccaavvii aarrcchheeoollooggiiccii i primi scavi della città romana furono condotti nella seconda metà del settecento, sotto il pontificato di pio vi. la direzione dei lavori fu affidata all’architetto giuseppe pannini che, nel testo pubblicato da g.a. guattani (1784-1805), definì questi scavi “senz’alcun dubbio tra i più fecondi del secolo”. sempre il guattani pubblicò i disegni del pannini relativi alla pianta della città e ad alcuni monumenti, in parte integrati con deduzioni personali dell’autore (pietrangeli, 1978). un esempio è fornito dal disegno delle “grandi sostruzioni”, rappresentate dal pannini come un edificio simmetrico rispetto ad un’asse centrale e, per questa simmetria, interpretato come un antico alloggiamento militare. al contrario pietrangeli (1978), rilevando un’accentuata asimmetria tra le due ali delle grandi sostruzioni, perché probabilmente costruite in epoche diverse, motivò la costruzione del complesso con due esigenze. innanzi tutto, vi era la necessità di sostenere il terreno immediatamente alle spalle del complesso e a valle del foro così da migliorarne la stabilità riducendone la pendenza, e per creare, al contempo, un fronte monumentale verso roma e il tevere. l’imponente costruzione, pertinente probabilmente ad un santuario del tipo di giove anxur a terracina, doveva sostenere un edificio pubblico, forse un tempio (cenciaioli, 2000), di cui non rimane traccia. nel corso dell’ottocento ocriculum fu soggetta a sporadici interventi di scavo, anche sostenuti dalla sensibilità artistica dell’epoca a rappresentare rovine archeologiche in dipinti e litografie, la stessa ocriculum fu usata come soggetto, interpretato in stile romantico, in una litografia francese (papi, 2001). fig. 3 uno scorcio dell’anfiteatro e sullo sfondo il paese di otricoli. the amphitheatre and the village of otricoli in the background. fig. 4 due monumenti funerari lungo la via flaminia, a nicchia (sulla destra) e a torre (sulla sinistra). tower and nich tombs along the flaminia road. fig. 5 tratto della via flaminia basolato con blocchi di lava leucitica. the flaminia road’s paved stretch with leucitic lava blocks 210 gli scavi r ipresero nella seconda metà del novecento, condotti dal dott. u. ciotti, furono indagati l’anfiteatro, le terme, il teatro e, in parte, le grandi sostruzioni. negli ultimi decenni le ricerche sono state riprese dalla soprintendenza per i beni archeologici dell’umbria (a cura della dott. a.e. feruglio), con scavi e saggi in alcuni punti della città romana, con lo scopo soprattutto di ricostruire esattamente il sito archeologico. di recente le indagini hanno interessato la zona appena al di fuori dell’area urbana, mettendo in luce il monumento funerario rotondo e il tratto della via flaminia descritti in precedenza. l’importanza di ocriculum come centro di commercio e di transito è suggerita dall’assenza di mura difensive intorno alla città e dalla presenza di monumenti di rappresentanza e di strutture di prestigio, come attestano le tracce di ville rustiche e di residenze estive appartenenti ai “nobilis” romani, tra i quali, ad esempio, tito annio milone (uccisore di clodio, 53 a.c.), pompea celerina (suocera di plinio il giovane) e la famiglia manlia (11-84 a.c.) (cenciaioli, 2000; martinori, 1929). le ville rustiche, sorte con la centuriazione dei terreni agricoli nella seconda metà del i sec. a.c., corrispondono spesso a proprietà sorte in questa parte dell’umbria per la mitezza del clima e la bellezza del paesaggio (“ville d’otium”); sono aziende agricole produttrici di cereali e vino, o artigianali, produttrici di laterizi (bonomi ponzi, 1995). le “coppe di popilio”, ad esempio, sono stati famosi manufatti in terracotta rossa non verniciata prodotti in ocriculum, mentre, in età imperiale, la presenza di cave di argilla a poca distanza dalla città romana ha favorito lo sviluppo di importanti fabbriche di tegole e mattoni. 33.. aassppeettttii mmoorrffoollooggiiccii il territorio che ospita il sito archeologico di ocriculum presenta una morfologia abbastanza morbida e dolce, interrotta talvolta da pareti scoscese. l’insediamento è situato in un’ampia conca, che si restringe e approfondisce avvicinandosi al tevere, mentre è racchiusa ai lati tra due contrafforti naturali in tufo, dall’evidente carattere difensivo, che si elevano a quote di poco superiori a 80 m. il potere erosivo delle acque superficiali, unitamente alla facile erodibilità dei terreni affioranti, sono la chiave per comprendere l’evoluzione morfologica di questo sito archeologico. il tevere e il torrente s. vittore sono gli elementi morfologici che più hanno influenzato lo sviluppo della città di ocriculum: il tevere in quanto importante via di comunicazione fluviale e il torrente s. vittore perché direttrice attorno alla quale è cresciuta la città. l’antico percorso del fiume di roma è suggerito, oltre che da vecchi toponimi testimoni di situazioni passate, dalla presenza di terrazzi fluviali che delimitano le sponde dell’antico alveo, in parte celati da una vegetazione rigogliosa. il toponimo fiume morto, ad esempio, assegnato ad un’ansa fluviale attualmente interrata e bonificata, ricorda come il tevere lambisse con un ampio meandro il versante sotto all’abitato di monte (otricoli), dove sorgeva il “porto dell’olio”, mentre scorreva ad una ventina di metri di distanza rispetto all’attuale riva del versante su cui sorse ocriculum. nel corso del tempo l’impetuosità del tevere ha modellato i versanti che delimitano il suo tracciato, innescando fenomeni di erosione talvolta anche molto intensa per scalzamento al piede del pendio. esempi riconducibili a questi fenomeni franosi si osservano tuttora al margine dei tavolati di tufo che si affacciano sul fiume, o si rilevano nella zona del “porto dell’olio” a testimoniare l’antico tracciato fluviale. in particolare nel 1688, in seguito al verificarsi di fenomeni franosi nella zona del porto, la congregazione del buon consiglio inviò sul posto l’architetto francesco sforzini. sforzini suggerì una nuova sistemazione della zona portuale, durante la quale il porto fu spostato provvisoriamente sotto il tavolato di tufo di s. vito (il tavolato che delimita a nord la valle di ocriculum). la strada che scendeva al porto e si distaccava dalla via flaminia in località crocefisso, fu rifatta nel 1720 con un percorso analogo a quello attuale (pietrangeli, 1978). il “porto dell’olio” fu utilizzato con frequenza fino alla fine del ’700, a conferma che il percorso del tevere, in questo tratto, è rimasto pressoché invariato per secoli. olio, vino, grano e altri generi commestibili erano tra i prodotti più commerciati e, soprattutto, legna tagliata nei boschi circostanti otricoli; come attesta un recente rinvenimento avvenuto nell’area archeologica, relativo ad un addetto alla pesatura dei carichi di ligna (cenciaioli, 2000). dalla fine del ’700 in poi il transito fluviale si arrestò in seguito ad un aumento progressivo del livello del fiume (pietrangeli, 1978) che rendeva impossibile il traino delle imbarcazioni (è solo a partire dal 1804, chirografo del 17 ottobre 1804 di pio vii, che per il tiro dei “navicelli” si cominciarono ad usare bufali anziché uomini). il tracciato del torrente s. vittore ha subito anch’esso dei mutamenti nel corso dei secoli determinati principalmente da interventi di natura antropica che bertacchini (2002), sulla base di rilevamenti effettuati sul terreno, di osservazioni geologico-geomorfologiche e dei resti di manufatti di età romana ancora osservabili, ha ipotizzato essere stati effettuati in fasi successive, attribuendo all’opera dei romani una serie di oculati interventi di ingegneria idraulica. in particolare bertacchini (2002) ha supposto che in epoca romana, antecedente o contemporanea la costruzione delle terme, possa essere stata realizzata una deviazione del torrente s. vittore con il proposito sia di impedire un approfondimento erosivo dell’alveo, sia di stabilizzare e sanare l’area valliva che era stata prescelta per costruire l’abitato di ocriculum. il corso d’acqua fu per questo imbrigliato e incanalato in un condotto sotterraneo in muratura, per una lunghezza di circa 300 m (cenciaioli, 2000). la canalizzazione attraversava la zona delle terme e delle grandi sostruzioni sino al teatro, all’altezza del quale il torrente riprendeva il suo alveo sino a sfociare nel tevere, non lontano dalla chiesa di s. vittore. le terme poterono essere costruite nel ii sec. d.c. su un’area pianeggiante, livellata e sistemata artificialmente. l’articolata opera di livellazione fece uso di due spessi muri di sostegno disposti normalmente all’asse della valle con la funzione di briglia (bertacchini, 2002). un primo muro fu posto a valle verso il tevere (fig. 6a), quasi di fronte al teatro, il successivo invece a monte a fianco alle terme (fig. 6b). m. bertacchini & l. cenciaioli 211 44.. aassppeettttii ggeeoollooggiiccii ee ggeeoommoorrffoollooggiiccii nella zona oggetto di studio affiora una successione del pliocene sup.-pleistocene inf., medio recentemente descritta da mancini et al. (2001a, b) e composta da sedimenti inizialmente di ambiente marino passanti a depositi di ambiente fluviale continentale, ai quali si sovrappongono materiali piroclastici prodotti dal vulcano di vico (fig. 7). la successione sedimentaria di ambiente marino inizia con argille e argille sabbiose di colore grigio, grigio piombo, con abbondante malacofauna, di ambiente di piattaforma e di transizione infra-litorale, dell’unità delle “argille sabbiose di ambiente marino” del pliocene sup.pleistocene inf. (mancini et al., 2001a, b). caratteristico è l’affioramento in prossimità della confluenza tra il torrente san vittore ed il tevere: le argille grigiastre appaiono variegate da sottili livelli chiari dovuti a concentrazioni di resti di organismi bentonici di ambiente marino di piattaforma e spiaggiati che, a luoghi, sottolineano la blanda stratificazione debolmente inclinata verso est-nord est. verso il tetto di quest’unità la componente sabbiosa diviene progressivamente più abbondante sino a prevalere. segue l’unità delle “sabbie siltose e silt di ambiente marino” di ambiente di piattaforma del pliocene sup.pleistocene inf. (mancini et al., 2001a, b); sono formate da sabbie a laminazione incrociata contenenti orizzonti più cementati tipo beach rock e conglomerati (fig. 7). quest’ultimi sono generalmente costituiti da ciottoli poligenici di piccole e medie dimensioni, provenienti dalle formazioni della successione umbro-marchigiana, discretamente arrotondati e immersi in abbondante matrice limoso-sabbiosa. all’unità delle “sabbie siltose e silt di ambiente marino” si sovrappone l’unità continentale di “civita castellana” di ambiente fluviale del pleistocene inferiore terminale-pleistocene medio iniziale (mancini et al., 2001a, b). l’unità di civita castellana si presenta come un conglomerato a scarsa matrice sabbiosa, a luoghi ben cementato, con ciottoli ben arrotondati, anche appiattiti, di diversa natura, ma prevalentemente calcarea e selciosa (selce nera e rossa). la dimensione dei ciottoli varia da centimetrica a pluricentimetrica. all’interno di quest’unità sono presenti lenti siltose gradate e poco cementate con spessore dell’ordine del decimetro. i rilievi più elevati del territorio otricolano (quote di poco superiori a 200 m) sono formati dai depositi ghiaiosi dell’unità di civita castellana (fig. 7); mancini et al. (2001a, b) indicano per detta unità uno spessore massimo di 120 m che si riduce a poco più di 20 m nell’area di studio. la successione sedimentaria continua con un deposito ghiaioso a cemento calcareo potente qualche metro, formato da elementi calcarei, selciosi e vulcanici anche decimetrici della “unità di rio fratta” (fig. 7) del pleistocene medio terminale (mancini et al., 2001a, b). questo deposito ghiaioso affiora in ottima esposizione lungo tutto il versante affacciato verso i l tevere a sud di ocriculum, al di sotto del bancone tufaceo, e a tetto passa ad un intervallo formato da sabbie grossolane a cemento calcareo spesso circa 30 cm, forse correlabile con la “unità di fiano” della fine del pleistocene medio (mancini et al., 2001a, b). il materiale vulcanico che ricopre i sedimenti descritti in precedenza è associato all’attività dell’apparato vicano situato ad un centinaio di chilometri a sud ovest di otricoli. questo materiale, indicato come “tufo rosso a scorie nere” (fig. 7), è riconducibile alle ultime fasi eruttive del complesso vulcanico vicano che mancini, et al. (2001a, b) riferiscono all’ignimbrite c vicana di 155.000 anni fa. i tavolati in tufo rendono particolare il paesaggio che qui si osserva. le superfici pianeggianti dei tavolati, tra 82 e 90 m di quota, se da un lato fianchegfig. 6 i romani colmarono e livellarono la conca di ocriculum in diverse fasi con lo scopo di ottenere un’ampia zona pianeggiante. a) nella prima fase fu costruito un muro di sostegno con la funzione di briglia nella parte inferiore del torrente s. vittore, in prossimità del teatro. b) nella fase successiva fu costruita una seconda briglia più a monte del corso d’acqua, vicino alle terme. the romans filled and levelled the valley of ocriculum in different phases to obtain a wide plain area. a) in the first phase a barrier-wall was built in the lower part of the stream (close to the tiber river). b) in the next phase the second barrier-wall was built in the upper side of the stream (close to the baths). uno sguardo sulla città romana di ocriculum 212 giano le discontinue creste dell’unità di “civita castellana”, dall’altro scendono bruscamente con pareti subverticali, per svariati metri, verso morfologie più dolci e depresse, impostate nelle litologie a sabbie e argille sottostanti. il materiale tufaceo è a composizione tefriticofonolitica (baldi et al., 1974; mancini et al., 2001a, b) ed è generalmente di colore grigio scuro con inclusi nerastri di dimensione variabile da centimetrica a decimetrica. i depositi descritti sino ad ora, sia quelli di origine sedimentaria sia quelli di origine vulcanica, sono caratterizzati da uno scarso grado di cementazione che, unitamente all’inclinazione, pur non eccessiva, dei versanti dove affiorano, facilita una loro mobilizzazione in concomitanza di eventi piovosi intensi e/o prolungati. la diversa permeabilità di questi depositi e dei loro prodotti di alterazione, giustifica la presenza di numerose sorgenti nella zona, come ricordano, ad esempio, i toponimi fontana, fontana cannella, alcune delle quali ad uso civile come la sorgente della fonte acquabona, ben nota anche nel passato come recita una lapide del 1500, posta sulla fonte (pietrangeli, 1978). i depositi superficiali che ricoprono il territorio di ocriculum sono prodotto dell’interazione perdurata nel tempo delle acque superficiali e della forza di gravità. lunghi nastri di terrazzi coronano il percorso attuale e storico del fiume di roma, mentre i terrazzi originati dal torrente s. vittore sono, per ovvie ragioni, meno estesi. al contrario, la recente attività erosiva del s. vittore ha portato ad affiorare la coltre alluvionale che il torrente aveva deposto in epoche passate. si possono osservare depositi di spessore decimetrico contenenti resti di manufatti ceramici e laterizi del ii-i sec. a.c. e del i-iv sec. d.c. gli intervalli più antichi sono formati da ciottoli eterometrici non classati e matrice sabbiosa di colore giallo ocra; quelli più recenti sono gradati e costituiti da ciottoli centimetrici arrotondati e orientati, immersi in abbondante matrice limoso-sabbiosa giallastra. depositi sempre prodotti dall’azione delle acque superficiali si rinvengono nella zona del foro, a contatto con il tufo, nei pressi delle piccole sostruzioni. sono sedimenti poco potenti e di ridotta estensione, caratterizzati da conglomerati ben selezionati, formati in prevalenza da ciottoli centimetrici calcarei, silicei, arenacei e vulcanici, con matrice sabbiosa, riferibili all’unità fluviale di “spicciano” del pleistocene sup. (mancini et al., 2001a, b). la deposizione di questi materiali suggerisce la presenza di fasce preferenziali di scorrimento e incanalamento delle acque e di successivo accumulo. tali depositi sono coperti e, talvolta, incisi da materiale più ricco in matrice, costituito da ciottoli simili a quelli del deposito sottostante, anche se di minori dimensioni e dispersi in una matrice limoso-sabbiosa più abbondante a tetto dello strato. nella sezione affiorante immediatamente sopra il fig. 7 successione stratigrafica del territorio di ocriculm (da: mancini et al., 2001a, b, modif.). stratigraphic sequence of ocriculum area (modif. by mancini et al., 2001 a, b). m. bertacchini & l. cenciaioli tratto di basolato (fig. 8) si osserva una successione di diversi episodi di dilavamento formati da strati di spessore decimetrico di sabbie grossolane e ciottoli centimetrici, contenenti resti di vita quotidiana del i-ii sec. d.c. al loro interno è possibile rinvenire resti di manufatti di piccole e medie dimensioni, frammenti di ossa animali (cervi, cinghiali, ecc.) e frustoli carboniosi prodotti delle attività antropiche, oltre a frammenti di ostree, a segnalare apporti da sedimenti marini. la sezione, che nel tratto esposto ha uno spessore complessivo di circa un metro, presenta alla base due intervalli decimetrici: quello inferiore contiene frammenti di marmi e di laterizi, quello superiore, di spessore variabile, ingloba frammenti di intonaci, laterizi e vetri del i sec. d.c. gli episodi soprastanti sono gradati con un accenno di orientazione e sono costituiti da ciottoli centimetrici passanti a sabbie grossolane, immersi in una matrice limoso-sabbiosa di color ocra contenente frustoli carboniosi concentrati in letti e frammenti di ossa. tutta l’area archeologica è ricoperta da uno spessore elevato di materiale formato da abbondante matrice, scarso ciottolame e privo di tracce di orientazione. a conferma di ciò, i risultati dei sondaggi commissionati alcuni anni fa dalla soprintendenza per i beni archeologici dell’umbria nell’area delle terme, hanno rilevato uno spessore di diversi metri di detrito sopra le rovine archeologiche, con una profondità di 4-5 m dal p.c. per le fondazioni dell’impianto termale. un altro sondaggio, realizzato alcuni metri sotto la base di queste fondazioni, campionò materiale che per i suoi aspetti litologici fu assimilato a terreno di riporto (dati inediti cenciaioli). i sedimenti che hanno sepolto la città di ocriculum si possono ricondurre a due diverse ipotesi evolutive: possono essere interpretati come deposito colluviale oppure come materiale prodotto da eventi franosi di colata. non è facile stabilire quale di questi due processi abbia prevalso nell’interrimento della città, è più probabile ritenere che si sia verificata un’azione combinata di entrambi i processi. 55.. eevvoolluuzziioonnee rreecceennttee ddeellll’’aarreeaa la notevole quantità di detrito che ha sommerso le rovine archeologiche di ocriculum si suppone sia provenuta da più settori del versante che domina ad oriente la città romana (fig. 9). le aree di svuotamento sono ben visibili sia da fotografie aeree sia da osservazioni sul terreno e, in generale, si presentano come aree concave impostate al contatto tra i sedimenti marini dell’unità delle “argille sabbiose” e quelli dell’unità delle “sabbie siltose e silt”. la scarsa vegetazione che ricopriva a tratti i versanti, in occasione di periodi freddi e piovosi, può avere favorito l’innescarsi di processi di degrado che si possono essere rapidamente evoluti in movimenti franosi, oppure si possono essere sviluppati in tempi più lunghi quando associati alla formazione di depositi colluviali. il deposito colluviale si sarebbe formato durante periodi di intenso ruscellamento superficiale. la conseguente mobilizzazione dei sedimenti incoerenti presenti avrebbe trasformato i versanti in zone di transito di materiale verso l’area pianeggiante, arrivando a coinvolgere ingenti quantità di terreno. il ripetersi di questo processo in più fasi successive può aver causato l’accumulo di una potente coltre detritica nella zona di pianura, dove sorgeva la città romana. viceversa, gli stessi materiali incoerenti o scarsamente cementati a componente sia sedimentaria, sia piroclastica, presenti nel territorio intorno a ocriculum, possono essere stati interessati da fenomeni franosi in concomitanza di intensi eventi meteorici giornalieri, soprattutto se preceduti da prolungati periodi piovosi. in particolare, sul versante a est di ocriculum, tra il pod. s. francesco e la loc. fontana, si individuano alcune possibili zone di innesco di eventi franosi, contornate da nicchie o balze rocciose. l’estensione delle zone di innesco è limitata, ma la discesa del materiale lungo il versante, sfruttando la sua pendenza e, dove presente, la superficie strutturale a franapoggio del tufo, può avere amplificato il fenomeno coinvolgendo gran parte del materiale più disgregato presente sulla superficie. la convergenza delle zone di accumulo di questi movimenti franosi verso la conca della città romana, fornirebbe altresì una valida giustificazione all’elevato spessore di sedimenti che hanno ricoperto il sito archeologico. l’assenza di tracce o elementi morfologici che confermino il fenomeno franoso porta a dubitare di quest’ultima ipotesi; anche se, solitamente, dissesti di questo tipo coinvolgono spessori limitati di terreni molto erodibili che l’azione del tempo può avere cancellato. 213 fig. 8 sezione sopra il tratto basolato della via flaminia. “flaminia basolato” section. different decimetric beds of coarse sand and centimetric beds of fine to medium grained pebbles mixed in a silty-sandy matrix can be observed. these beds are frequently graded with a weak orientation. remains from the 1st and 2nd century a.d. are often found: pieces of glass, marble, bricks, plaster and animal bones, as well as carbonaceous fragments of domestic fires and ostrea fossils. uno sguardo sulla città romana di ocriculum 214 fig. 9 stralcio della carta geologico-geomorfologica del territorio di ocriculum (base topografica fornita per conc. reg. umbria, 11864/’u2001). a particular of the geological-geomorphological map of the ocriculum area (licence from reg. umbria, ref. n. 11864/’u2001). m. bertacchini & l. cenciaioli 66.. ccoonnssiiddeerraazziioonnii ccoonncclluussiivvee la città di ocriculum sorse nel i sec. a.c. in un’area a poche decine di chilometri di distanza da roma, alla quale era collegata attraverso due importanti vie di comunicazione: la via flaminia e il tevere. la città si sviluppò intorno al torrente s. vittore, difesa naturalmente da due contrafforti in tufo sopra e a ridosso dei quali furono costruiti importanti edifici e ville patrizie. in origine l’area doveva presentarsi come una piccola conca moderatamente incisa dal torrente s. vittore; al fine di creare superfici pianeggianti ampie e stabili, i romani si affidarono alla costruzione di terrazzamenti e di notevoli opere murarie, come le sostruzioni. il problema di colmare e livellare la conca fu probabilmente affrontato dai romani con un progetto articolato in più fasi (bertacchini, 2002). in una prima fase fu costruito un muro di sostegno verso valle, intorno a quota 70 m e trasversale al torrente, con lo scopo di portare ad una diversa altezza il livello di riferimento del tevere. conseguentemente il torrente cominciò a divagare e a ristagnare nella zona a monte della briglia e a depositare i sedimenti trasportati, colmando progressivamente la valle (fig. 6a). una volta colmata la conca si rendeva necessario regolarizzare il corso d’acqua per evitare fenomeni di erosione e di alluvionamento e, per questo scopo, fu costruito un secondo muro a monte e canalizzato il torrente (fig. 6b) per una lunghezza di 300 m circa. nell’area otricolana affiora una successione sedimentaria del pliocene sup.-pleistocene inf., medio (mancini et al., 2001a, b) composta da argille, argille sabbiose e sabbie di ambiente marino passanti a conglomerati di ambiente fluviale, a cui si sovrappongono depositi tufacei del pleistocene medio terminale (mancini et al., 2001a, b) legati all’attività del vulcano di vico. lo scarso grado di cementazione che caratterizza tutti questi depositi può aver favorito l’innesco di fenomeni di dissesto in concomitanza di eventi piovosi intensi e/o prolungati. l’area archeologica fu infatti sepolta sotto una spessa coltre di materiale formato da abbondante matrice con ciottoli sparsi e privo di tracce di orientazione, proveniente da diversi settori del versante ad est di ocriculum e riconducibile a due diverse tipologie di processi: a depositi di tipo colluviale o a depositi prodotti da eventi franosi di colata. entrambi i processi hanno contribuito al seppellimento della città romana. è plausibile pensare che l’abbandono di ocriculum sia avvenuto tra la fine del vi e il vii sec. d.c., anche in analogia con altri siti noti in letteratura, proprio in concomitanza con il periodo indicato come minimo climatico dell’alto medioevo (camuffo & enzi, 1994), o anche noto come “piccola età glaciale alto medievale” (ortolani & pagliuca, 2000). le condizioni climatiche frescoumide che interessarono il bacino del mediterraneo provocarono sicuramente un aggravamento delle condizioni di degrado del territorio otricolano, già peraltro provato da uno stato di incuria e abbandono che succedette al declino della civiltà romana. le fonti storiche non riportano dati a conferma di un probabile trasferimento degli abitanti di ocriculum nel paese di monte durante questo periodo di degrado ambientale; ma, successivamente, a partire dal vii sec. d.c., è solo l’abitato di otricoli ad essere citato nei documenti storici mentre termina qualunque tipo di attività umana nell’antica città di ocriculum. rriinnggrraazziiaammeennttii la ricerca esposta in queste pagine è frutto della collaborazione avviata dal compianto prof. paolo fazzini tra il dipartimento di scienze della terra dell’università degli studi di modena e reggio emilia e la soprintendenza per i beni archeologici dell’umbria, in particolare con la dott. a.e. feruglio soprintendente fino al 2000, e con la dott. l. bonomi ponzi, attuale soprintendente reggente. un ringraziamento particolare per gli utili consigli di carattere geologico è rivolto a d. castaldini, d. fontana e m. panizza del dipartimento di scienze della terra dell’università di modena e reggio emilia. rriiffeerriimmeennttii bbiibblliiooggrraaffiiccii ambrosetti p., conti m.a., parisi g., kotsakis t. & nicosia u. (1977) – neotettonica e cicli sedimentari plio-pleistocenici nei dintorni di città della pieve (umbria). boll. soc. geol. it., 9966, 605-635. ambrosetti p., carboni m.g., conti m.a., esu d., girotti o., la monica g.b., landini b. & parisi g. (1987) – il pliocene e il pleistocene inferiore del bacino del fiume tevere nell’umbria meridionale. geogr. fis. dinam. quat., 1100, 10-33. baldi p., decandia f.a., lazzarotto a. & calamai a. (1974) – studio geologico del substrato della copertura vulcanica laziale nella zona dei laghi di bolsena, vico e bracciano. mem. soc. geol. it., 1133, 575-606. bertacchini m. (2002) – a glance at the roman town of ocricolum (central italy). iv reunión nacional de geoarqueologia. almazán, soria – spain, 16-18 settembre 2002, in stampa. bonomi ponzi l. (1995) – l’umbria meridionale dalla protostoria all’alto medioevo. in: viae publicae romanae. provincia di terni, terni, 128 pp. camuffo d. & enzi s. (1994). cambiamenti climatici negli ultimi 2000 anni. il quaternario, 77(1), 257266. cenciaioli l. (2000) – ocriculum. guida ai monumenti della città antica. ministero per i beni e le attività culturali. soprintendenza archeologica per l’umbria. lab. tip. la fratta, umbertide (pg), 47 pp. cenciaioli l. (2001) – il territorio di otricoli tra umbri e sabini. annali della fondazione per il museo “claudio faina”, orvieto, 88, 293-318. cenciaioli l. (2002a) – nuovi scavi a otricoli lungo la via flaminia. conv. forum sempronii e la via flaminia, fossombrone, urbino, 25-27 giugno 1999, 89-101, in stampa. cenciaioli l. (2002b) – ocriculum. in: umbria antica. vie d’acqua e di terra. sopr. beni arch. dell’umbria, elemond s.p.a., città di castello, 45 pp. 215uno sguardo sulla città romana di ocriculum conti m.a., parisi g. & nicosia u. (1983) – un orizzonte ad amphistegina nel pliocene di orvieto e sue implicazioni tettoniche. boll. soc. geol. it., 110022, 113-122. guattani g.a. (1784-1805) – monumenti antichi inediti per l’anno mdcclxxxiv. vol 11, roma. mancini m., girotti o. & cavinato g.p. (2002a) – carta geologica della media valle del tevere (appennino centrale). settore settentrionale. scala1:40000. centro di studio per il quaternario e l’evoluzione ambientale-cnr, autorità di bacino del fiume tevere, dipartimento di scienze della terra, università di roma “la sapienza”. mancini m., girotti o. & cavinato g.p. (2002b) – carta geologica della media valle del tevere (appennino centrale). settore meridionale. scala1:40000. centro di studio per il quaternario e l’evoluzione ambientale-cnr, autorità di bacino del fiume tevere, dipartimento di scienze della terra, università di roma “la sapienza”. martinori e. (1929) – via flaminia studio storico-topografico. stab. tip. regionale, roma, 233 pp. messineo g. (1993) – via flaminia. istituto poligrafico e zecca dello stato, roma, 185 pp. ortolani f. & pagliuca s. (2000) variazioni climatiche del periodo storico e la prevedibilità delle prossime modificazioni ambientali. geoitalia. forum italiano di scienze della terra. fist. 6, dicembre, mediaprint livorno 39-41. papi l. (2001) – analisi delle problematiche e tecniche di recupero per la tutela e conservazione della chiesa tiberina di san vittore in otricoli. d.u. in materiali per la manutenzione del costruito antico e moderno, facoltà di ingegneria, università di perugia, a.a. 2000-2001. tesi di laurea inedita, 141 pp. pietrangeli c. (1978) – otricoli, un lembo di umbria alle porte di roma. roma, 383 pp. questo lavoro, consegnato alla rivista nel febbraio 2003, è stato revisionato e aggiornato grazie ai dati di bibliografia gelogica recente fornita dai referees. m. bertacchini ha curato gli aspetti descrittivi ed evolutivi del territorio insieme alle osservazioni di collegamento ai dati archeologici-bibliografici forniti da l. cenciaioli. imolto materiale proveniente dall’antica città di ocriculum è stato riutilizzato in numerose abitazioni dell’odierna otricoli. passeggiando per le strette vie del centro, in parte lastricate con blocchi di lava leucitica, è possibile osservare case e palazzi, come quello settecentesco dei conti squarti perla, ornati con fregi a girali, architravi e fregi dorici. 216 ms. ricevuto il 27 febbraio 2003 testo definitivo ricevuto il 15 luglio 2003 ms. received: february 27, 2003 final text received: july 15, 2003 m. bertacchini & l. cenciaioli sess 1_160211.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 erosion and sedimentary processes in the metaponto offshore (north ionian sea) maria rosaria senatore1, agostino meo1, modestino boscaino1 & francesco latino chiocci2 1 dipartimento di studi geologici ed ambientali università degli studi del sannio, benevento 2 università degli studi di roma ‘sapienza’, roma corresponding author: m. r. senatore <senatore@unisannio.it> abstract: senatore m.r. et al., erosion and sedimentary processes in the metaponto offshore (north ionian sea). (it issn 0394-3356, 2011) this study is based on surveys carried out to realize the sheet n° 42 metaponto of the magic project and pertain to the analysis of the morpho-dynamic processes acting on the seafloor by means of multibeam data and seismostratigraphyc interpretation of chirp and sparker 1 kj profiles. the active recognized sedimentary processes have allowed to define morphological units and to distinguish three sectors with different erosional and depositional forms. riassunto: senatore m.r. et al., erosione e processi sedimentari nell’offshore di metaponto (mare ionio settentrionale). (it issn 0394-3356, 2011) questo studio si basa su indagini svolte per realizzare il foglio n° 42 metaponto del progetto magic e riguarda l'analisi dei processi morfo-dinamici che agiscono sul fondale marino utilizzando dati multibeam e l’interpretazione sismo-stratigrafica di profili chirp e sparker 1 kj. i processi attivi sedimentari riconosciuti hanno permesso di definire le unità morfologiche e di distinguere tre settori con differenti forme di erosione e deposizione. key words: marine geology, basilicata offshore, submarine landslide, canyon parole chiave: geologia marina, settore marino della basilicata, frane sottomarine, canyon  this study is based on surveys carried out to realize the sheet n° 42 metaponto. of the magic project (marine geohazards along the italian coasts). the project, funded by the national civil protection department, aims to define geological hazard features along the italian coasts through the analysis of seafloor geomorphology. the metaponto offshore is part of the gulf of taranto, located between the apennine thrust sheets to the west and the apulia foreland to the east, representing the plio-pleistocene southern extension of the chain foredeep (bradanic foredeep) (pescatore & senatore, 1986). the western sector of the gulf of taranto is characterized by the presence of two thrust fronts: the most recent one is the edge of the allochthonous units, while the second, which is deep-seated and older than the previous one, is located in a more internal position and affects the western inner apulia platform (senatore et al, 1988). corigliano and amendolara basins, located in the zone behind the two thrust fronts and unconformably lying on the deformed units, can be interpreted as piggyback basins. the gulf of taranto central sector is occupied by the taranto valley, located between the front of the allochthonous units and the apulia foreland; it represents the present foredeep of the southern apennine chain. the eastern sector of the gulf of taranto represents the present southern apennine foreland (belfiore et al., 1981, rossi et al., 1982; tramutoli et al., 1984; pescatore & senatore, 1986) mainly affected by normal sub-vertical faults. the analysis of the morpho-dynamic processes acting on the seafloor of the metaponto offshore, was performed by means of multibeam data and seismo-stratigraphyc interpretation of chirp and sparker 1 kj profiles. the physiographic domains identified are the continental shelf, that, from north to south, shows different morphological features, and the continental slope, with a very uneven morphology. the active sedimentary processes acting in the two recognized domains have been represented through suitable morpho-bathimetric elements allowing to define different morphological units. thus the study area has been divided into three sectors (fig. 1) defined by means of erosional and depositional identified forms: the north-eastern sector; the north-western sector; the southern sector. the north-eastern sector corresponds to very northern part of the apulia ionian continental slope. the sea-floor shows the typical concave-convex form linked to widespread gravitational instability probably extending beyond the study area. the headscarps are identified from a depth of 300 m and have a maximum width of 4 km. the deposit area occurs from a depth of 550 m and reaches 63 65 64 50 km2. the heads carve the edge of the shelf very deeply, shaping it in a morphology defined as "cauliflower". many linear incisions have been identified where the average sloping is of 7 8%. they in part disappear down dip where the sloping decreases significantly reaching values of about 4%. at greater depths, between 500 m and 800 m, the northern canyon system reaches the depressed area of the valley of taranto, stretching along the toe of the continental slope. the valley, that represents the main sediments collector of this canyon system, is both a bypass and depositional zone of sediment. the southern canyon system, is located from the mouths of the basento river and agri river. at depth of 550 m, the canyon has width about 8 km; in this area the phenomena of transport and temporary deposition of sediments coming from the head occur. at the end of the canyon a strip parallel to the slope develops, sloping less than 4%, in which depositional bodies have been identified, stretched according to the axis of the canyon, probably linked to the last lowstand of the sea level and covered by a sediment drape . the southern sector comprises both the continental shelf and slope and extends from the mouth of the agri river up to the rocca imperiale marina offshore. the continental shelf is well developed, has an average width of 8 km with an almost flat trend up to the edge, located at a depth of 130 m. the shelf marginal zone, for a length of 17 km and an width of 2 km, presents at the bottom undulations almost parallel to the margin itself. they have heights ranging from 3 to 6 m and wavelengths between 250 m and 500 m. the undulations greatest development occur between the offshore of lido di policoro and agri river. according to rebesco et al., (2009), which identified the same forms, in the southern part of gulf of taranto, both on the shelf and at greater depths, these undulations could represent either deposition of sediments from hyperpicnal flows or deformations due to slow sediment movements (creep). according to petruccione et al. (2010) iorio et al. (2010); senatore et al. (2010), the undulations, very common on continental shelves, are linked to slow sediment deformation triggered by the combined effect of high sedimentation rate, typical of the prodelta areas, and gas trapped in the sediment, which weakening the cohesion trigger the sliding process. the continental slope develops from a depth of 130 m, extending toward east for about 15 km, to a depth of 1400 m. the sloping is not constant; values of 7% gradually decrease up to 2% from a the eastern edge of the taranto valley, where shows a width ranging from 3.5 km to 1.7 km. the total area occupied by this gravitational process is of about 25 km2, with an average length of about 6 km and an estimated volume of mobilized sediment approximately of 245 km3, assessed by means of seismic reflection profiles. the north-western sector comprises both the continental shelf and slope and extends from marina di ginosa to the mouth of the river agri. the shelf from north to south shows a progressive increase in width, from 2 km off metaponto lido, 5 km near the town of scanzano ionico, up to 6 km off the mouth of the river agri. the identified morpho-bathimetric elements are erosional furrows carving increasingly toward the shelf margin the bottom sediments. they achieve their maximum development in the offshore of the rivers mouths of bradano, basento, cavone and agri. the continental slope extends from a depth of 30 m to 600 m. its upper part, up to an average depth of 450 m, is characterized by the presence of two canyon systems, which cover a total area of about fig. 1, study area; the different indicated sectors are described in the text. area di studio; i diversi settori indicati, sono descritti nel testo. m.r. senatore et al. 65 ms. received: testo ricevuto il (italy). spec. publ. int. ass. sediment., 8, 169182. petruccione e., aiello g., capretto g., senatore m.r.,marsella e., iorio m. (2010) – late pleistocene and holocene geomorphology of a channel and sediment marine deformation process on the cuma outer shelf (eastern tyrrhenian sea, italy): an integrated approach. cnr, rassegna delle attività marine e marittime, accettato per la stampa . rebesco m., neagu r.c., cuppari a., muto f., accettella d., dominici r., cova a., romano c., caburlotto a. (2009) morphobathymetric analysis and evidence of submarine mass movements in the western gulf of taranto (calabria margin, ionic sea). int. j. earth sci. (geol. rundsch), 98, 791805. rossi s., auroux c., & mascle j., (1983) – the gulf of taranto (southern italy) : seismic stratigraphy and shallow structure. mar. geol., 51, 327346. senatore m.r. (1987) – caratteri sedimentari e tettonici di un bacino di avanfossa. il golfo di taranto. mem. soc. geol. it., 38, 177204. senatore m.r., normark w.r., pescatore t. & rossi s. (1988) – structural framework of the gulf of taranto (ionian sea). mem. soc. geol. it., 41, 533539. senatore m.r., chiocci f. l., pescatore t., di nocera s. et al. (2010) – note illustrative al f. 508 “policoro” della carta geologica d’italia alla scala 1:50.000. ispra – servizio geologico d’italia. tramutoli m., pescatore t., senatore m.r. & mirabile l. (1984) – interpretation of reflection high resolution seismic profiles through the gulf of taranto (ionian sea, eastern mediterranean. the structure of apennine and apulia deposits. boll. oceanol. teor. appl., 2, 3352  depth of 400 m to 600 m; from 600 m, the slope increases again up to 22% at about 1000 m. the slope is characterised: between 130 and 400 m by a narrow-spaced network of gullies with small incision, between 400 m to 600 m by a depositional area which has been interpreted as intraslope basin between 600 m to 1400 m, by an area affected by landslides, cutting the sediments of the intraslope basin and carrying them to the taranto valley. the rough morphology of the slope must be linked to the complex structure of the substrate that corresponding to the front of the chain. references belfiore a., bonaduce g., garavelle g., mascellaro p., masoli m., mirabile l., moncharmont m., moretti m., nuovo g., pennetta m., pescatore t., placella b., pugliese n., russo b., sansone e., sanatore m.r., sgarella f., spezie g., thorez j., tramutoli m., & vultaggio m. (1981) – la sedimentazione recente del golfo di taranto (alto ionio, italia). ann. ist. navale, napoli, 49-50, a 3, 1196. iorio m., capretto g., petruccione e., marsella e., senatore m.r. (2010) defining sedimentary and gravitative processes in highstand prodelta deposits by means of multiproxy analysis: an example from the phlaegrean offshore, eastern tyrrhenian margin, sottomesso per la stampa. pescatore t. & senatore m.r. (1986) – a comparison between a presentday (taranto gulf) and a miocene (irpinian basin) foredeep of the southern apennines january 20, 2011 20 gennaio 2011 erosion and sedimentary processes in the ... imp.carveni&solleva sollevamenti a grande scala e conseguenti fenomeni gravitativi: l’esempio del versante orientale dell’etna (sicilia) pietro carveni 1, domenico bella 2, santo benfatto3, rosanna maniscalco1, maria salleo puntillo4 & giovanni sturiale1 1università di catania, dipartimento di scienze geologiche, corso italia 57 95129 catania, italia; e.mail: carveni@unict.it; 2geologo, centro studi sull’ambiente, via nino martoglio 13, 95024 acireale, catania, italia; 3geologo, libero professionista, via san marco 91, 95047 paternò, catania, italia; 4naturalista, via san marco 91, 95047 paternò, catania, italia. riassunto: carveni p., bella d., benfatto s., maniscalco r., salleo puntillo m. & sturiale g., sollevamenti a grande scala e conseguenti fenomeni gravitativi: l’esempio del versante orientale dell’etna. (it issn 0394-3356, 2005). nell’ambito di un generale sollevamento che interessa la costa orientale della sicilia, un settore dell’edificio vulcanico etneo è caratterizzato da fenomeni di abbassamento; le zone interessate dai due fenomeni contrastanti sono facilmente riconoscibili lungo la costa. sulla base di una rilettura critica della letteratura reperita, cui hanno fatto seguito rilievi geologico-geomorfologici di dettaglio, sono state ricostruite le variazioni relative del livello marino medio in alcuni siti ubicati lungo la costa orientale della sicilia, tra torre archirafi a settentrione e la baia di ògnina (catania) a meridione; i dati evidenziano movimenti differenziali con un arretramento della linea di costa nella zona tra torre archirafi e stazzo ed un innalzamento della costa tra aci castello e catania. per meglio caratterizzare i fenomeni di abbassamento, è stata studiata la sismicità di tre importanti faglie con direzione nnw-sse per il periodo compreso tra il 1805 e il 1989, mediante la ricostruzione dei campi macrosismici dei terremoti più significativi relativi alle strutture in oggetto; l’entità complessiva del movimento lungo i piani di faglia durante il periodo considerato è la somma delle dislocazioni avvenute in relazione ai sismi e di fenomeni di creep asismico; dai dati ottenuti risulta che le dislocazioni lungo i singoli piani di faglia considerati sono compresi tra 0,2 e 1,5 cm/anno; l’analisi delle curve isosisme ha fatto ipotizzare la presenza di faglie sinora non riconosciute, ma la cui esistenza è ipotizzabile anche su basi morfologiche e geofisiche. i risultati sono in accordo con i dati di letteratura relativi alla dinamica del versante orientale etneo, il quale risulta soggetto ad un progressivo scivolamento verso ese tramite lo svincolo costituito dalla faglia della pernicana a settentrione e le faglie di mascalucia e di trecastagni a se. abstract: carveni p., bella d., benfatto s., maniscalco r., salleo puntillo m. & sturiale g., regional uplift and consequent gravitational phenomena: the example of eastern slope of mt etna volcano. (it issn 0394-3356, 2005). mt. etna is the largest active volcano in europe; it is a volcanic complex, formed by products of several eruptive centres, which were active in different times. it is located on the margin of two main structural domains of eastern sicily: the hyblaean foreland and the apennine-maghrebian chain. the hyblaean foreland belongs to the northern part of the african plate; it is formed by a very thick triassic to pleistocene carbonate succession, with several intercalations of mafic volcanic rocks. the apennine-maghrebian chain consists of several thrust sheets, made up of structural units derived from different palaeogeographical domains; they were overthrusted upon each other during several tectonic phases from eocene to pleistocene. eastern sicily is interested by a general uplift but a sector of the etna volcanic building is characterized by lowering. along the ionian sea coast we recognized uplift movements between catania and aci castello and subsidence between stazzo and torre archirafi. the lower eastern slope of mt. etna volcano is a high seismic hazard zone; it is characterized by superficial hypocentres earthquakes with little mesoseismic area. information is available about earthquakes which happened in this region during the last two centuries. the seismic activity of three faults was studied in the time span between 1805 and 1989. tectonic movements also caused very important landscape variations, like waterfalls and river piracies. our studies demonstrate that the subsidence along the coast is the result of the total amount of displacement measured along the fault planes (moscarello, san leonardello and macchia-stazzo faults). the analysis of the isoseismal lines suggests the presence of not yet known faults, whose existence is also testified on morphological and geophysical bases. the results of this paper agree with the data of literature related to the dynamics of the eastern slope of mt. etna; it is subject to a progressive sliding toward ese. parole chiave: versante orientale del monte etna, tettonica, geomorfologia, variazioni della linea di costa. keywords: eastern slope of mt. etna volcano, tectonics, geomorphology, changes of coast line. il quaternario italian journal of quaternary sciences 18(2), 2005 157-171 1. introduzione e scopo del lavoro il monte etna è un vulcano composito, localizzato lungo la costa orientale della sicilia. il suo basso versante orientale è interessato da un fascio di faglie normali con direzione generale nnwsse, con movimento prevalentemente verticale, la cui attività, che si manifesta attraverso terremoti con ipocentro superficiale e fenomeni di creep asismico, ha dato luogo ad una fossa tettonica conosciuta come graben di san leonardello. queste faglie hanno provocato variazioni del paesaggio, influenzando l’andamento della rete drenante e della linea di costa (platania, 1905 a; 1922; adorni & 158 p. carveni et al. carveni, 1993 a; 1993 b; carveni & bella, 1994; bella et al., 1996; carveni et al., 1997). recenti studi (gironi, 2003) hanno evidenziato che, mentre la maggior parte dell’edificio etneo è solidale con le zone circostanti, e si solleva con un tasso di circa 15 mm/anno, il settore delimitato dalla faglia della pernicana a settentrione e dall’arco congiungente il cratere centrale con aci castello a meridione è interessato da un movimento di abbassamento. nel presente articolo viene studiata in dettaglio l’attività di alcune delle suddette faglie, attraverso la rielaborazione dei dati reperibili in letteratura, rilievi geologico-geomorfologici di dettaglio e campagne di misurazioni realizzate attraverso l’utilizzo di estensimetri nel periodo 1994 – 2004. in particolare, vengono ricostruiti i campi macrosismici di alcuni terremoti che hanno interessato l’area, confrontando i risultati con i già esistenti dati di letteratura; il trattamento dei dati permette di ricostruire il movimento medio delle singole faglie per il periodo compreso tra il 1805 e il 1989; la sommatoria dei movimenti lungo i piani di faglia viene messa in relazione con i fenomeni di variazione del livello del mare registrati nell’area costiera sottoposta geograficamente alle strutture tettoniche. dato il breve intervallo di tempo considerato, si ritiene che la maggior parte delle variazioni del livello marino riconosciute siano svincolate da fenomeni di eustatismo e collegate essenzialmente alla dinamica del basso versante orientale etneo. 2. inquadramento geologico-strutturale il monte etna, con la sua altitudine di poco superiore ai 3.300 metri e col diametro massimo di 44 chilometri, è il maggiore vulcano attivo del continente europeo; esso è uno strato-vulcano complesso, risultante dalla sovrapposizione di prodotti emessi da diversi edifici (gemmellaro, 1858; lyell, 1859) poggianti su un basamento in parte alloctono, formato da rocce di età compresa tra il cretaceo ed il pleistocene (cristofolini et al., 1979; romano et al., 1979; lentini, 1982). il bacino del mediterraneo centrale, nel quale si inserisce l’etna, è caratterizzato da differenti domini strutturali, la cui genesi è da inquadrare nel contesto collisionale tra la placca africana e la placca europea; le due masse continentali si scontrano e si saldano tra loro formando l’orogene appenninico – maghrebide, una catena corrugata che forma la dorsale appenninica e, attraversando l’arco calabro, la sicilia ed il canale di sicilia, prosegue lungo le coste nord-africane del maghreb. l’edificio vulcanico etneo sorge al limite tra diversi domini strutturali della sicilia orientale, dove la crosta oceanica ionica e la crosta continentale dell’avampaese ibleo si inflettono sotto i l fronte dell’orogene appenninico maghrebide (finetti et al., 1996) (fig. 1). l’avampaese ibleo costituisce il margine della placca africana (burollet et al., 1978), zona stabile verso cui convergono le falde neogeniche dell’orogene appenninico maghrebide. esso è costituito da una potente successione prevalentemente carbonatica compresa tra il triassico ed il pleistocene medio; vi si intercalano, a vari livelli, prodotti effusivi basici cretacei, miocenici e plio-pleistocenici, la cui risalita è stata provocata da intense fasi tettoniche distensive (cristofolini, 1966; di grande, 1967; 1969; 1972; patacca et al., 1979; carbone et al., 1982 c; lentini et al., 1986; carbone et al., 1987; carveni et al., 1991 a; 1991 b; 1993; carveni & sturiale, 1999). esso confina ad oriente con la crosta oceanica del bacino ionico (finetti, 1982), tramite la scarpata ibleo-maltese, di origine tettonica (finetti & morelli, 1972), originata da un sistema di faglie normali a gradinata, il cui prolungamento verso settentrione interseca il fianco orientale dell’edificio etneo (lo giudice et al., 1982; carbone et al., 1982 a; 1982 b); la scarpata ibleomaltese si sarebbe formata in un’unica grande fase tortoniana, con riattivazioni di minore entità posteriormente al deposito degli infrapliocenici trubi; a luoghi sono state individuate importanti emissioni vulcaniche connesse alla scarpata (casero et al., 1984). lanzafame & bousquet (1997) ritengono che la scarpata ibleo-maltese sia solo un segmento di un importante sistema di faglie con direzioni comprese tra nnw-sse e nw-se, che, attraversando la sicilia nordorientale e il tirreno meridionale, raggiunge vulcano, lipari e salina. l’orogene appenninico-maghrebide si è formato in seguito all’accavallamento della catena kabilocalabride, costituita da falde di basamento cristallino interessate da metamorfismo ercinico con resti dell’originaria copertura sedimentaria meso-cenozoica, sulla catena appenninico-maghrebide, edificio orogenico formato dalla sovrapposizione di falde sud-vergenti, il cui corrugamento ha interessato, deformandole, le coperture sedimentarie della tetide e dei paleodomini minori ad essa associati, originariamente ubicati tra il margine della placca europea ed il margine della placca africana (finetti et al., 1996). fig. 1 schema strutturale della sicilia (da finetti et al., 1996). ai) avampaese ibleo; cam) catena appenninico-maghrebide; ckc) catena kabilo-calabride; cs) catena sicana; e) edificio vulcanico etneo; agc) avanfossa gela – catania; sim) scarpata ibleo-maltese; smf) sistema di faglie messina – fiumefreddo; il rettangolo indicato dalla freccia corrisponde alla zona in studio. structural scheme of sicily (after finetti et al., 1996). ai) hyblaean foreland; cam) apennine-maghrebian chain; ckc) kabilo-calabrian chain; cs) sicana chain; e) mount etna volcano; agc) gela – catania foredeep; sim) hyblaean-malta escarpment; smf) messina – fiumefreddo fault system; narrow indicates position of studied area. l’avanfossa gela-catania è un bacino subsidente formatosi in seguito alla flessione dell’avampaese ibleo sotto le coltri alloctone della catena appenninicomaghrebide; essa è stata colmata da sedimenti pliopleistocenici che coprono in parte la falda di gela, la quale rappresenta il fronte più avanzato della catena (lentini, 1982). ad iniziare dal pleistocene inferiore, in questo quadro geodinamico compressivo, intense fasi tettoniche hanno causato un’elevata distorsione lungo il margine settentrionale della placca africana, a causa della differente velocità con cui avviene la subduzione al di sotto della catena appenninico maghrebide (van bemmelen, 1969; morelli, 1970; selli & fabbri, 1971; giese & morelli, 1975), e ciò ha determinato uno stiramento crostale che ha dato luogo a fratture con direzione nwse, ne-sw ed e-w (ghisetti & vezzani, 1982; scandone, 1982); all’intersezione di tali strutture si è formata una zona di debolezza attraverso la quale avviene la risalita di magmi sub-crustali (frazzetta & villari, 1981). sulla genesi del vulcano e sul quadro strutturale sono reperibili in letteratura numerosi modelli: 1) intersezione tra due importanti lineamenti strutturali: la scarpata ibleo-maltese e il sistema di faglie messina fiumefreddo (ogniben et al., 1975; mcguire et al., 1997); 2) risultato di una tettonica estensionale che ha portato alla formazione di un graben in corrispondenza dell’attuale piana di catania (di geronimo et al., 1978); 3) processi di rifting tra il blocco maltese siciliano ed il bacino ionico (gillot et al., 1994; continisio et al., 1997); 4) deformazione al footwall di una faglia normale appartenente al sistema distensivo siculo-calabro ad andamento wnw-ese (monaco et al., 1997); 5) risalita di magmi dal mantello a causa di un hot spot (tanguy et all., 1997); 6) roll-back di una porzione di litosfera subdotta al di sotto del mar tirreno (gvirtzman & nur, 1999). a causa di un sollevamento regionale, l’attività eruttiva dell’etna, inizialmente sottomarina e fissurale, è diventata in seguito subaerea ed a carattere centrale; ciò ha causato una variazione nel meccanismo di risalita dei magmi, con conseguente cambiamento del chimismo: da lave subalcaline si è passati a prodotti più o meno differenziati della serie alcalino-sodica (romano, 1982). sulla base di datazioni radiometriche del rapporto k/ar, sono stati distinti quattro periodi di attività dell’etna, intervallati da periodi di quiescenza (gillot et al., 1994): il primo periodo (da 520.000 ± 40.000 a 270.000 anni fa) è caratterizzato da vulcanismo tholeiitico (fig. 2: 6), con fasi eruttive separate da lunghi periodi di quiescenza; il secondo periodo (da 168.000 ± 8.000 a 100.000 anni fa) è evidenziato da un radicale cambiamento del tipo di attività (strato-vulcani al posto di fessure eruttive) e del chimismo dei prodotti da subalcalini ad alcalini (fig. 2: 5); durante il terzo periodo (tra 80.000 e 60.000 anni fa) si formò un grande complesso vulcanico poligenico chiamato trifoglietto (fig. 2: 4); il quarto periodo (da 35.000 anni fa ad oggi) corrisponde allo sviluppo di un grande strato-vulcano, il mongibello; un’importante fase, caratterizzata da eruzioni pliniane e idromagmatiche, permette di suddividere questo periodo in due parti: mongibello antico (fig. 159sollevamenti a grande scala ... 2: 2) e mongibello recente (fig. 2: 1). tra l’attività del trifoglietto e quella del mongibello si inserisce un episodio di parziale smantellamento dell’edificio etneo, con il trasporto di ingenti masse detritiche che diedero luogo ad un deposito ghiaioso (fig. 2: 3), localmente conosciuto col nome di chiancone (romano & sturiale, 1981; romano, 1982; guest et al., 1984; kieffer & tanguy, 1993); contemporaneamente all’estinzione dei vecchi centri eruttivi si verificava uno spostamento del condotto principale verso nw (romano, 1982). 3. assetto strutturale del versante orientale etneo platania (1922), basandosi sui movimenti registrati lungo alcuni piani di faglia in occasione di forti terremoti (1865, 1879, 1881, 1911 e 1920), teorizza un’origine sismotettonica per alcune scarpate ubicate sul versante orientale dell’edificio vulcanico etneo; la conferma gli viene fornita da puglisi (in platania, 1922); questi, direttore della società acque di casalotto, in base a rilievi di superficie e dati provenienti da pozzi e gallerie drenanti, descrive quattro faglie con direzione circa ns, comprese tra la periferia occidentale di aci sant’antonio e l’alta falesia della timpa di acireale (fig. 3: sas); questo autore ipotizza che le faglie si siano formate come reazione di una parte dell’edificio etneo al graduale sollevamento della zona; in particolare egli rileva, lungo alcune gallerie drenanti, sia il rigetto verticale, sia lo spostamento orizzontale verso il mare, e su queste basi ipotizza l’esistenza di un fenomeno franoso che inizia nella zona di aci bonaccorsi e si propaga verso la costa; il fatto che egli descriva una “stratificazione inclinata verso monte” lungo i piani di fratturazione, suggerisce che si tratti di faglie listriche. carapezza (1962), nel tentativo di determinare una relazione tra la tettonica regionale e le zone di minore resistenza dell’etna, identifica un rift lungo il fianco orientale dell’edificio vulcanico. marchesini et al. (1964) riconoscono quattro principali allineamenti tettonici, con direzioni n-s, enewsw, ne-sw e nw-se. frazzetta & romano (1978) identificano due allineamenti alimentatori preferenziali per le aree ad alta probabilità di eruzioni: una nel settore circolare compreso tra ne-sw e ene-wsw, la seconda con direzione nnw-sse. lo giudice et al. (1982) riconoscono nell’area etnea e nelle zone circostanti varie direttrici di faglie: le più importanti hanno direzione n 60° e, n 30° e, n 15° w e n 60° w. kieffer (1983 a; 1983 b) ipotizza scivolamenti gravitativi di parte del versante orientale dell’edificio vulcanico, ed attribuisce il fenomeno alla ripetuta intrusione di magma attraverso un rift di ne e un rift meridionale. l’ipotesi di uno scivolamento gravitativo viene ripresa da azzaro et al. (1989 a) e da neri et al. (1991). borgia et al. (1992), sulla base dei risultati ottenuti da ferrari et al. (1991) sui dicchi affioranti nella valle del bove, ipotizzano uno spreading radiale del substrato dell’etna verso se. lo giudice & rasà (1992) ritengono invece che si tratti di movimenti puramente gravitativi, che provocano 160 fig. 2 schema lito-stratigrafico del versante orientale dell’edificio vulcanico etneo e ubicazione delle località con tracce morfologiche e/o geologiche di antichi livelli del mare. cc) cratere centrale; 1) vulcaniti del mongibello recente; 2) vulcaniti del mongibello antico; 3) ghiaie del chiancone; 4) vulcaniti dei centri eruttivi del trifoglietto; 5) vulcaniti dei centri eruttivi alcalini antichi; 6) lave sub-alcaline di base; 7) unità post-orogene; 8) unità calabridi ed antisicilidi; 9) unità sicilidi. litho-stratigraphical scheme of etna eastern flank and location of morphological and/or geological sea level changes evidences. cc) central crater; 1) recent mongibello volcanic rocks; 2) ancient mongibello volcanic rocks; 3) chiancone gravels; 4) trifoglietto eruptive centres volcanic rocks; 5) ancient alkaline eruptive centres volcanic rocks; 6) basement sub-alkaline lava flows; 7) post-orogenetic units; 8) calabridi and antisicilidi units; 9) sicilidi units. p. carveni et al. 161 fig. 3 ubicazione delle più importanti faglie del versante orientale dell'etna: fcm) faglia capo schisò – foce del torrente macchia; ff) faglia di fondachello; fg) faglia di giardini; fm) faglia di moscarello; fma) faglia di mascalucia; fmg) faglia milo – giarre; fmr) faglia macchia – riposto; fms) faglia macchia – stazzo; fn) faglia di naxos; fp) faglia della pernicana; fpvc) faglia praiola – villa calanna; frn) faglia della ripa della naca; frp) faglia della ripa di piscio; fsl) faglia di san leonardello; ft) faglia di trecastagni; ftm) faglia del torrente minissale; sp) sistema di piedimonte. centri abitati: a) acireale; ab) aci bonaccorsi; ac) acicatena; as) aci sant’antonio; fi) fiumefreddo; fo) fondachello; g) giardini; m) mascalucia; ma) mascali; s) stazzo; sa) sant’alfio; st) santa tecla; t) trecastagni. centri eruttivi: cc) cratere centrale; mi) monte ilice; rne) rift di ne. i triangoli indicano zone in cui sono stati misurati sollevamenti e abbassamenti fino a 15 mm/anno (da gironi, 2003; carveni et al., 2005). location of the main faults on eastern flank of mt. etna volcano: fcm) cape schisò – macchia stream mouth fault; ff) fondachello fault; fg) giardini fault; fm) moscarello fault; fma) mascalucia fault; fmg) milo – giarre fault; fmr) macchia – riposto fault; fms) macchia – stazzo fault; fn) naxos fault; fp) pernicana fault; fpvc) praiola – villa calanna fault; frn) ripa della naca fault; frp) ripa di piscio fault; fsl) san leonardello fault; ft) trecastagni fault; sp) piedimonte system. towns: a) acireale; ab) aci bonaccorsi; ac) acicatena; as) aci sant’antonio; fi) fiumefreddo; fo) fondachello; g) giardini; m) mascalucia; ma) mascali; s) stazzo; sa) sant’alfio; st) santa tecla; t) trecastagni. eruptive centres: cc) central crater; mi) monte ilice; rne) ne rift. triangles indicate uplift or lowering zones up to 15 mm/y (after gironi, 2003; carveni et al., 2005). sollevamenti a grande scala ... 162 lo scivolamento verso sse della porzione dell’edificio etneo delimitata a settentrione dalla faglia della pernicana e dal rift di ne, e a se dalle faglie di mascalucia e trecastagni (fig. 3). la documentazione storica relativa ai terremoti avvenuti sul basso versante orientale etneo negli ultimi due secoli e le conseguenze morfologiche dei movimenti tettonici sono analizzate in una serie di articoli (adorni & carveni 1993 a; 1993 b; carveni & bella, 1994; bella et al., 1996; carveni et al., 1996; 1997; gresta et al., 1997). dall’analisi dei sistemi di faglie che nel pleistocene sono stati attivi in sicilia orientale, sulla base di informazioni geologico-strutturali e morfologiche e dell’analisi di sezioni sismiche a mare, monaco & tortorici (1995) e monaco et al. (1995; 1997) distinguono un sistema acireale – sant’alfio (faglie normali con componente trascorrente destra nnw-sse) e un sistema di piedimonte (faglie normali e fratture d’estensione nne-ssw); entrambi i sistemi, associati ad un’estensione wnw-ese, formano scarpate di età suprapleistocenico-olocenica, le quali esercitano un controllo sulla topografia e sul reticolo idrografico. ricerche basate su rilievi effettuati da satelliti (gironi, 2003) evidenziano un sollevamento in atto di tutta la zona etnea con punte massime di 15 mm/anno, con eccezione del settore delimitato a settentrione dalla faglia della pernicana e sua prosecuzione verso oriente, e a sw dalle faglie di mascalucia e trecastagni: questa zona risulta essere interessata da un fenomeno di abbassamento con un tasso massimo di circa 15 mm/anno a stazzo, frazione di acireale, dove un molo costruito nel 1949 e alto circa 90 centimetri, attualmente si trova al livello del mare (figg. 3 e 4). 4. variazioni del livello marino: dati di letteratura già a partire dalla prima metà del xix secolo sono reperibili in letteratura dati inerenti a movimenti differenziali della linea di costa nel tratto di mare jonio compreso tra taormina a settentrione e catania a meridione (fig. 2); la lacuna di informazioni riguarda la correlazione tra i vari dati esistenti in letteratura. la loro correlazione evidenzia la presenza di un’area centrale localizzata nel sito di torre archirafi (fig. 2: g) soggetta a fenomeni di abbassamento, confinata a nord e a sud, lungo la linea di costa, da due aree in sollevamento. per quanto riguarda i fenomeni di sollevamento, dalle ricerche bibliografiche risulta che il primo a riconoscere tracce di variazioni del livello marino lungo la costa ionica della sicilia è stato gemmellaro (1837), il quale ha descritto il solco di battente esistente attorno ai promontori di capo sant’alessio e capo sant’andrea, nei pressi di taormina (fig. 2: a). gemmellaro (1859) determina un sollevamento della costa compresa tra catania e aci trezza, in base al ritrovamento di depositi di origine marina tra 0,4 e 1 metro sul livello marino nella baia di ògnina (fig. 2: b), di una sabbia conchiglifera a 1 metro di quota sul lato settentrionale della rupe di aci castello (fig. 2: c) e di incrostazioni conchigliari comprese tra 4 e 13 metri di quota sull’isola lachea (fig. 2: d). platania (1905 a) osserva che le argille pleistoceniche affioranti a 700 metri di quota presso santa maria la vena (fig. 2: e) costituiscono l’indizio di un recente sollevamento del versante orientale dell’etna; inoltre, in base all’esistenza di incrostazioni di conchiglie a 5,4 metri di quota sulla falesia di aci castello (fig. 2: f), formata da una colata di lava datata al 1169 da sartorius von waltershausen (1880), calcola un sollevamento della zona costiera di 8 millimetri all’anno; è chiaro comunque che il calcolo è errato per difetto: le incrostazioni di conchiglie allora osservate a 5,4 metri d’altezza non si saranno formate sulla superficie della colata appena raffreddata, ma su una superficie d’erosione, diversi anni dopo la fine dell’eruzione: ne deriva una maggiore velocità di sollevamento. platania (1905 b; 1912; 1915) descrive una serie di marmitte dei giganti presenti sull’isola lachea (fig. 2: d) e nel porto di aci trezza (fig. 2: h); attribuendone la genesi ad onde di tempesta, non si rende conto della prova di un abbassamento relativo del livello del mare che tali morfologie testimoniano. platania (1922) riconosce il recente sollevamento generale della regione etnea, comprovato dalle argille quaternarie affioranti a presa (fig. 2: i), santa maria la vena (fig. 2: e) e santa venera (fig. 2: l); egli inoltre segnala l’esistenza di incrostazioni calcaree, contenenti frammenti di stoviglie di epoca romana, ubicate intorno a 14 metri sul livello del mare lungo la costa di aci castello (fig. 2: m); tracce di erosione marina riconosce egli stesso intorno a 80 metri di quota sulla timpa di santa maria la scala (fig. 2: n). de fiore (in zambonini, 1925) descrive le argille con faune calabriane affioranti sulla coll ina di vampulieri, presso aci trezza, a 120 metri di quota (fig. 2: o). secondo romano & sturiale (1981) la colata lavica che circonda ad occidente la rupe di aci castello, e che presenta tracce di abrasione marina e fori di litodomi a 6 metri di quota, è stata emessa tra il 122 a.c. e il 252-253 d.c., testimoniando un sollevamento della zona costiera di circa 3 mm/anno. per quanto riguarda i fenomeni di abbassamento l’unica testimonianza ci viene tramandata da platania (1905 a) il quale rileva tale fenomeno lungo la costa in corrispondenza dell’abitato di torre archirafi (fig. 2: g), dove i ruderi dell’eponima torre, eretta nel 1594 (scarlata, 1993), si trovavano, al momento in cui egli fece le fig. 4 il molo nuovo e il molo vecchio di stazzo. new and old docks in stazzo port. p. carveni et al. indagini, a due metri di profondità; se il disegno attribuito da scarlata (1993) a camillo camiliani è fedele, la torre in oggetto sorgeva su una falesia alta circa 4 metri: se ne deduce un abbassamento della costa di circa 6 metri nell’arco di poco più di 300 anni, con un tasso medio calcolato di 2 centimetri all’anno. 5. variazioni del livello marino: nuovi dati sulla scorta di rilievi, e sulla base di una rilettura critica della letteratura, sono state riconosciute altre testimonianze geomorfologiche di variazioni del livello marino. 5.1. la rupe di aci castello nella zona di aci castello affiorano alcuni dei prodotti vulcanici più antichi emessi nella zona etnea (gillot et al., 1994); nel complesso, la rupe su cui sorge il castello è formata in prevalenza da lave a cuscini e brecce vulcanoclastiche (corsaro & cristofolini, 2000) facenti parte delle lave sub-alcaline di base (romano et al., 1979); a sw della rupe (fig. 5) si trova una colata lavica subaerea, emessa tra il 122 a.c. e il 252-253 d.c. (romano & sturiale, 1981), poggiante su una piattaforma d’abrasione marina ubicata a circa 4,5 metri di altezza, costituita da lave a cuscini, con chiare tracce di metamorfismo da contatto (fig. 6). tutt’intorno alla rupe esiste un’altra piattaforma d’abrasione marina impostata su lave a cuscini, ubicata a un metro circa di quota (fig. 5); nella zona orientale della rupe si vedono 3 nicchie assimilabili a solchi di battente, rispettivamente alle quote 1,5, 6 e 8,7 metri circa. l’insieme delle testimonianze morfologiche consente la seguente ricostruzione: 1) il moto ondoso scava il solco di battente attualmente ubicato a 8,7 metri di quota (fig. 7 a: a); 2) in seguito ad un sollevamento della zona si forma il solco di battente di quota 6 metri (fig. 7 b: b); 3) un secondo sollevamento è testimoniato dalla piattaforma di quota 4,5 metri (fig. 7 b: c); 4) in occasione di un terzo sollevamento la rupe, precedentemente isolata, si unisce alla terraferma; la piattaforma d’abrasione di cui al punto precedente emerge e questa, tra il 122 a.c. e il 252-253 d.c., viene ricoperta da una colata di lava (fig. 7 c); 5) in seguito ad un innalzamento relativo del livello del mare, la colata lavica viene interessata dall’erosione marina che vi forma una falesia, presto colonizzata da litodomi (fig. 7 d); 6) un nuovo abbassamento relativo del livello marino porta alla formazione del solco di battente di quota 1,5 metri e della piattaforma di quota 1 metro (fig. 7 e); 7) un ulteriore sollevamento della zona porta alla configurazione attuale (fig. 7 f). 5.2. il porto di stazzo stazzo, frazione del comune di acireale, è stata costruita lungo la costa (fig. 3), all’estremità di una colata lavica del 1329 emessa da una fessura eruttiva ubicata al margine sud-orientale dell’edificio piroclastico di monte ilice (romano & sturiale, 1982); l’erosione marina ha prodotto una falesia con numerose piccole insenature. al limite meridionale della colata, al contatto con le preesistenti vulcaniti, attribuite all’attività del mongibello recente (romano et al., 1979), esiste una piccola rada, utilizzata come riparo per barche da pesca, con un molo di recente costruzione; accanto a questo se ne trova uno più antico, inutilizzabile in quanto il suo pavimento si trova a fior d’acqua (fig. 4); da informazioni assunte in loco, risulta che il molo vecchio è stato costruito nel 1949, e che esso era alto circa 1 metro sul livello del mare; ciò consente di calcolare un abbassamento della zona costiera di circa 1,8 cm/anno per il periodo considerato. 6. analisi della sismicità storica dell’area al fine di trovare le cause che spieghino il fenomeno di abbassamento registrato a torre archirafi e a stazzo, in contrasto con il generale sollevamento dell’intera area etnea, si sono studiate le più importanti faglie presenti sul basso versante orientale dell’etna e la relativa sismicità; la zona è interessata sia da un’attività sismica “lontana”, dovuta a risentimenti di importanti eventi con epicentri ubicati lungo l’arco calabropeloritano o nel plateau ibleo, sia da una frequente sismicità locale con profondità ipocentrali comprese tra 0,5 e 2 chilometri (patanè, 1975; benina et al., 1984; lo 163 fig. 6 il contatto tra la colata sub-aerea emessa tra il 122 a.c. e il 252-253 d.c. e quella sub-marina sottostante. stratigraphic boundary between subaerial lava flow (122 b.c. – 252-253 a.d.) and underlying submarine lava. fig. 5 panoramica della rupe di aci castello. panoramic view on aci castello castle rock. sollevamenti a grande scala ... 164 fig. 7 ipotizzata evoluzione morfologica della falesia a meridione della rupe di aci castello. hypothetic morphological evolution of southern cliff of aci castello castle rock. p. carveni et al. giudice, 1985; bottari et al., 1989; azzaro et al., 1989 a; 1989 b; lo giudice & rasà, 1992; carveni et al., 1996; gresta et al., 1997), con modesto raggio di avvertibilità e campo macrosismico di pochi chilometri quadrati. nella zona è stata inoltre individuata l’esistenza di lenti scorrimenti asismici (creep asismici) lungo alcuni piani di faglia (lo giudice, 1985). le faglie presentano meccanismi distensivi; è stato evidenziato che gli epicentri dei sismi sono localizzati prevalentemente lungo i segmenti settentrionali delle relative faglie, mentre lungo i tratti meridionali delle stesse si registrano solo fenomeni di creep asismico (carveni & bella, 1994). l’integrazione tra dati provenienti da indagini geoelettriche (cassinis et al., 1970) e dati relativi alle profondità ipocentrali di alcuni sismi (patanè, 1975; postpischl, 1985; azzaro et al., 1989 a; 1989 b; bottari et al., 1989) ha fatto ipotizzare una genesi di tipo gravitativo profondo per i movimenti sismici in oggetto (carveni & bella, 1994). per quanto di magnitudo relativamente modesta, alcuni dei terremoti avvenuti in quest'area hanno provocato ingenti danni alle costruzioni e la perdita di numerose vite umane; fra gli effetti cosismici sono stati segnalati spostamenti reciproci dei blocchi lungo i piani di faglia e l'apertura di fessure nel terreno (grassi, 1865; silvestri, 1865; 1866; 1867; 1883; platania & platania, 1894; platania, 1908; 1920; riccò, 1911; 1912; sabatini, 1914; castorina, 1920; cumin, 1954; riuscetti & distefano, 1971; azzaro et al., 1989 a). in occasione del sisma del 29 gennaio 1989 è stato registrato un movimento transtensivo destro (azzaro et al., 1989 a); altri autori hanno descritto slickenside sui piani delle faglie della timpa di moscarello e della timpa di santa tecla (bousquet et al., 1987). i dati relativi ai sismi con intensità maggiore al vii grado della scala ems-98 sono riportati in tabella 1. 6.1. attività della faglia di moscarello la faglia di moscarello è una faglia diretta con direzione complessiva n 20° w, geologicamente e sismicamente attiva (sensu bosi & carraro, 1979), sviluppo lineare di 10 chilometri circa, blocco orientale ribassato con piano quasi verticale; i suoi movimenti hanno provocato una scarpata che raggiunge lungo il tratto settentrionale un dislivello di 200 metri (timpa di moscarello). ferreri et al. (2000), tramite trincee esplorative, hanno riconosciuto i risultati di una fagliazione a scatti, con abbassamenti relativi compresi tra 2 e 4 mm/anno. 6.1.1. sisma del 19 luglio 1865 tra tutti i terremoti verificatisi sul fianco orientale dell'etna di cui si hanno notizie, quello avvenuto il 19 luglio 1865 è stato certamente il più forte. il villaggio di fondo macchia, costituito da almeno 90 edifici tra case e magazzini, distribuiti in un'ampia area, fu letteralmente raso al suolo: caddero a terra, verso ponente, tutte i manufatti, compresi i muri a secco alti meno di un metro (silvestri, 1865). lungo il piano di faglia fu osservato un abbassamento del blocco orientale variabile, a luoghi, da un minimo di 30 a un massimo di 60 centimetri; si formarono crepe parallele alla frattura principale con espulsione dal terreno di blocchi lavici e radici di alberi; il sisma provocò anche la caduta di massi lungo la timpa di moscarello (silvestri, 1865; grassi, 1865). nella figura 8 è rappresentato il campo macrosismico. 6.2. attività della faglia di san leonardello la faglia di san leonardello è una faglia diretta, geologicamente e sismicamente attiva, parallela alla faglia di moscarello (n 20° w), con sviluppo lineare di 5,5 chilometri e blocco orientale ribassato; essa si estende da macchia fino alla costa compresa tra 165 tab. 1. * cpti = catalogo parametrico dei terremoti italiani; 1) grassi, 1865; 2) riccò, 1911, 1912; 3) silvestri, 1865; 4) riuscetti & distefano, 1971; 5) patanè, 1975; 6) castorina, 1920; 7) platania, 1920; 8) cumin, 1954; 9) postpischl, 1985; 10) azzaro et al., 1989; 11) baratta, 1900. data epicentro faglia i0 (ems-98) mm d (km) rv (m) t rif 11 luglio 1805 fondo macchia moscarello viii-ix (?) 1, 2 26 gennaio 1855 fondo macchia moscarello viii 4.24 (*) dx 1 19 luglio 1865 fondo macchia moscarello xi 4.94 (*) 1.6±16% (9) 0,6 dx 1, 3 12 febbraio 1881 san matteo macchia – stazzo viii 3.8 8, 11 15 ottobre 1911 fondo macchia moscarello x 1.0 0,9 dx 2 26 settembre 1920 codavolpe san leonardello x 4.42 (*) 0.5±3.4% (9) 0,6 6, 7 8 aprile 1950 codavolpe san leonardello ix 4.0 0.7±13.6% (9) 8, 9 21 aprile 1971 sciara moscarello x 3.90 (*) 4 19 agosto 1973 mangano moscarello vii 5 29 gennaio 1989 codavolpe san leonardello viii 0.5±7.7% (9) 0,3 dx 10 sollevamenti a grande scala ... stazzo e santa tecla, ed è evidenziata da tratti di scarpate rettilinee con dislivelli massimi di 30 metri. mentre lungo i l settore settentrionale della faglia si sono verificati sismi di una certa intensità, il tratto meridionale è interessato da movimenti lenti (creep asismici); sono stati da noi misurati spostamenti di 1,2 cm/anno lungo alcune crepe in edifici di san leonardello. 6.2.1. sisma del 26 settembre 1920 gli effetti del terremoto del 26 settembre 1920 sono stati descritti da castorina (1920) e da platania (1920); il relativo campo macrosismico e rappresentato nella figura 9. a codavolpe crollarono molte case e tutte le altre furono danneggiate; si formarono nel terreno numerose fessure con direzione nnw-sse e fu notato lo spostamento di pesanti mobili verso nw, come reazione inerziale al movimento di trascorrenza destro. a san leonardello rimasero lesionate parecchie case (castorina, 1920). lungo la scarpata della faglia furono misurati rigetti verticali compresi tra un minimo di 30 e un massimo di 60 centimetri; la frattura beante poteva essere seguita sul terreno per diversi tratti, ognuno lungo centinaia di metri; furono segnalate fessure parallele alla faglia, a volte riunite in coppie; presso l'abitato di san leonardello si riaprì una frattura già formatasi in occasione del sisma del 1865 (castorina, 1920). 6.3. attività della faglia macchia-stazzo la faglia macchia stazzo è una faglia antitetica rispetto alle due precedenti: con direzione n 20° w, sviluppo lineare di poco più di 8 chilometri e blocco occidentale ribassato, essa delimita ad oriente il graben di san leonardello. gli indizi morfologici che ne fanno riconoscere l'esistenza sono meno evidenti di quelli relativi al le due faglie già descritte, a causa di una minore attività sismica: essa è eviden166 fig. 8 campo macrosismico del terremoto di fondo macchia del 19 luglio 1865. fondo macchia 1865, 19th july earthquake macroseismic field. fig. 9 campo macrosismico del terremoto di codavolpe del 26 settembre 1920. codavolpe 1920, 26th september earthquake macroseismic field. p. carveni et al. ziata da una scarpata quasi rettilinea, più evidente lungo il tratto meridionale dove ha causato diversi fenomeni di cattura di piccoli corsi d'acqua (adorni & carveni, 1993 a; 1993 b) carveni & bella, 1994; bella et al., 1996; carveni et al., 1997). l'unico sisma collegato a questa faglia di cui si abbiano notizie è avvenuto il 12 febbraio 1881; fratture e dislocazioni in manufatti costruiti in epoca posteriore al sisma evidenziano l'esistenza di fenomeni di scorrimento asismico tra i blocchi (creep asismici). da baratta (1900) si evince che i maggiori danni provocati dal sisma del 12 febbraio 1881 non sono stati subiti dal villaggio di codavolpe, fino ad oggi considerato epicentro relativo a questo sisma, ma dalla frazione di san matteo, dove si verificarono crolli totali di piccole case rustiche; tutto ciò porta a riconoscere la faglia macchia stazzo come responsabile di tale sisma, e non, come finora si era creduto, la faglia di san leonardello; ciò è confermato da quanto riportato da cumin (1954), secondo il quale in occasione di questo terremoto si sarebbe formata una frattura proprio alla base della scarpata della faglia macchia stazzo. il relativo campo macrosismico è stato ricostruito nella figura 10. a questo sisma è stata attribuita un'intensità epicentrale dell'viii grado, con mm 3,8 (postpischl, 1985), e del vi-vii grado (gresta et al., 1997). 7. discussione dei dati e conclusioni lo studio morfo-tettonico qui presentato, integrato con i risultati ottenuti da numerosi autori precedenti, permette di dare una spiegazione del fenomeno di abbassamento riscontrabile sul versante orientale etneo, e in particolare lungo il tratto di costa compreso tra la spiaggia di torre archirafi a settentrione e stazzo a meridione. le testimonianze geologico-geomorfologiche di un sollevamento generalizzato del territorio etneo sono note: basti citare gli affioramenti di argille marnose azzurre infrapleistoceniche di santa venera, presa e vena già individuati da platania (1905 a) e i numerosi terrazzi fluviali lungo le valli dei fiumi simeto e alcantara (romano et al., 1979); inoltre, nel già citato articolo di gironi (2003) risulta che il sollevamento dell’edificio etneo è solidale con le circostanti zone; fa eccezione il settore grossolanamente triangolare col vertice in corrispondenza del cratere centrale e la base lungo la costa ionica, delimitato a settentrione dalla faglia della pernicana, a nw dal rift di ne, a occidente e sw da una fascia di fratture eruttive e faglie dirette che, partendo dai crateri sommitali, scendono lungo il fianco meridionale dell’edificio vulcanico e giungono alla costa ionica tra la baia di ògnina e aci castello. il territorio compreso all’interno di questo settore è interessato dall’attività di alcune faglie dirette, appartenenti al sistema con direzione nnw-sse che ha dato luogo alla scarpata ibleo-maltese; esse, formando tra l’altro i l graben di san leonardello, sono responsabili della sismicità locale e hanno giocato un ruolo fondamentale nel condizionare l’idrografia superficiale e l’andamento della linea di costa (adorni & carveni, 1993 a; 1993 b; carveni & bella, 1994; bella et al., 1996; carveni et al., 1997). dalla testimonianza di puglisi (in platania, 1922) risulta inoltre l’esistenza di un movimento traslativo verso oriente lungo i piani delle faglie con direzione n-s che interessano la zona di aci sant’antonio (fig. 3: sas). questo versante presenta un particolare assetto geologico-strutturale, in quanto vi affiorano prevalentemente lave, con subordinati prodotti piroclastici e depositi alluvionali, poggianti su un substrato di argil le marnose azzurre infrapleistoceniche. in alcune zone il passaggio dalle argille del basamento preetneo alle soprastanti vulcaniti è stato determinato da cassinis et al. (1970); essi evidenziano l’esistenza di un orizzonte conduttivo assimilato alle argil le marnose azzurre infrapleistoceniche a profondità variabile al di 167 fig. 10 campo macrosismico del terremoto di san matteo del 12 febbraio 1881. san matteo 1881, 12th february earthquake macroseismic field. sollevamenti a grande scala ... sotto della superficie di campagna. dal confronto di questi dati con i risultati di alcuni studi sulla sismicità locale, risulta che le profondità ipocentrali dei terremoti avvenuti a codavolpe il 26 settembre 1920 (km 0,5 ± 3,4%, postpischl, 1985) e il 29 gennaio 1989 (km 0,5 ± 7,7%, azzaro et al., 1989 a) corrispondono al passaggio dalle argille infrapleistoceniche alle soprastanti lave; analogamente, per il sisma di san giovanni bosco del 2 febbraio 1986, azzaro et al. (1989 b) hanno calcolato una profondità ipocentrale poco inferiore a 1 chilometro, e cassinis et al. (1970) individuano in questa zona il passaggio argille/vulcaniti a 950 metri o poco più. sulla base di questi dati è stata ipotizzata l’origine gravitativa profonda per i movimenti della faglia di san leonardello (carveni & bella, 1994; carveni et al., 1997); il particolare assetto geologico-strutturale del versante, il diverso comportamento meccanico dei due complessi litologici e le notevoli precipitazioni meteoriche, che raggiungono 1.300 mm/anno a zafferana (ferrara, 1975), possono essere considerati cause concomitanti all’instaurarsi di condizioni di instabilità. l’andamento delle curve isosisme dei terremoti attribuiti alla faglia di moscarello evidenzia un forte tasso di assorbimento dell’energia sismica in direzione nord: ciò aveva fatto ipotizzare l’esistenza di una faglia con direzione circa e-w in corrispondenza della valle del torrente macchia (carveni & bella, 1994; carveni et al., 1997). questa faglia, sinora non riconosciuta in letteratura, può corrispondere ad un lineamento morfologico con andamento wnw–ese (faglia milo – giarre, fmg in figura 3), identificato tramite l’analisi del modello digitale del terreno (dem, favalli et al., 1999). dall’esame del catalogo dei terremoti dell’etna (azzaro et al., 2000) si rileva che all’attività di questa presunta faglia possono essere attribuiti cinque sismi verificatisi tra il 7 ed il 28 marzo 1910. una serie di 71 piccoli terremoti, distribuiti tra il 1874 e il 1920 (azzaro et al., 2000), con epicentri localizzati lungo un segmento compreso tra il porto di riposto e macchia di giarre, evidenzia l’esistenza di un’altra faglia, anch’essa non descritta in letteratura; questa ipotizzata struttura tettonica è anche evidenziata da una colata ad andamento rettilineo (romano et al., 1979), riversatasi lungo una valle impostatasi, presumibilmente, in corrispondenza del piano di faglia (fig. 3: fmr). in conclusione risulta evidente che la sommatoria dei movimenti di abbassamento lungo i due lati del settore in studio e lungo il sistema delle faglie che formano il graben di san leonardello può essere considerato come un cedimento gravitativo profondo, reazione al movimento generale di sollevamento della regione, che si manifesta, principalmente, nel rigetto verticale delle faglie che formano il graben di san leonardello. i rigetti misurati in occasione di alcuni tra i più forti terremoti generati dalle faglie in esame (tabella 1), permettono di valutare, con buona approssimazione, un rigetto medio pari a 50 centimetri, e considerando un periodo di 200 anni, dal 1805 ad oggi, si è calcolato un tasso di abbassamento di circa 2,5 cm/anno per la zona di stazzo (2 cm/anno nel più breve periodo 1949-2005) e di 2 cm/anno per la zona di torre archirafi. studio effettuato con i fondi del m.i.u.r., nell’ambito delle ricerche “morfodinamica di zone vulcaniche e/o sismicamente attive” e “morfodinamica di zone costiere sismicamente attive”, responsabile pietro carveni. ringraziamenti ringraziamo gli anonimi referees per gli utili e costruttivi consigli. lavori citati adorni g. & carveni p. (1993 a) geomorphology and seismotectonic elements in the giarre area, sicily. earth surf. proc. land., 18, 275-283. adorni g. & carveni p. (1993 b) anomalie del reticolo idrografico causate da eventi sismotettonici sul basso versante orientale dell’etna. boll. acc. gioenia sc. nat. catania, 26 (342), 197-206. azzaro r., barbano m.s., antichi b. & rigano r. (2000) macroseismic catalogue of mt. etna earthquakes from 1832 to 1998. acta vulcanologica, 12 (1-2), 3-36, con cdrom. azzaro r., carveni p., lo giudice e. & rasà r. (1989 a) il terremoto di codavolpe (basso versante orientale etneo) del 29 gennaio 1989: campo macrosismico e fratturazione cosismica. boll. g.n.v., 1, 112. azzaro r., lo giudice e. & rasà r. (1989 b) catalogo degli effetti macrosismici e delle fenomenologie da creep nell'area etnea dall'agosto 1990 al dicembre 1989. boll. g.n.v., 1, 13-46. baratta m. (1900) i terremoti d'italia. saggio di storia, geografia e bibliografia sismica italiana. arnaldo forni editore, torino, 950 pp. bella d., carveni p., musumeci c. & gresta s. (1996) aspetti geomorfologici conseguenti all'attività sismica locale sul basso versante orientale del vulcano etna. il quaternario, 9 (1), 365-368. benina a., imposa s., gresta s. & patanè g. (1984) studio macrosismico e strumentale di due terremoti tettonici avvenuti sul versante meridionale dell'etna. att. 3° conv. g.n.g.t.s., 2, 931-940. borgia a., ferrari l. & pasquarè g. (1992) importance of gravitational spreading in the tectonic and volcanic evolution of mt. etna. nature, 357, 231-235. bosi c. & carraro f. (1979) considerazioni terminologiche in campo sismotettonico. geogr. fis. dinam. quat., 2, 21-28. bottari a., carveni p., lo giudice e., pietrafesa m., birritta g. & stillitani e. (1989) criteri di utilizzo e rappresentazione grafica del dato macrosismico nella redazione di una carta sismotettonica. att. 8° conv. ann. gr. naz. geof. terra solida: 191-202. bousquet j.c., gresta s., lanzafame g. & paquin c. (1987) il campo degli sforzi attuali e quaternari nella regione dell'etna. mem. soc. geol. it., 38, 483-506. burollet p.f, mugnot g.m. & sweeney p. (1978) the geology of the pelagian block: the margins and basins of southern tunisia and tripolitania. in: nairn a., kanes w. & stelhi f.g., eds., the ocean basins and margins, plenum press, new york, 331-339. 168 p. carveni et al. carapezza m. (1962) un esempio di eruzione laterale da faglia nell’apparato eruttivo etneo. acta geol. alpina, 8, 249-276. carbone m.s., cosentino m., grasso m., lentini f., lombardo g. & patanè g. (1982 a) elementi per una prima valutazione dei caratteri sismotettonici dell’avampaese ibleo (sicilia sud-orientale). mem. soc. geol. it., 24, 507-520. carbone m.s., grasso m. & lentini f. (1982 b) considerazioni sull’evoluzione geodinamica della sicilia sud-orientale dal cretaceo al quaternario. mem. soc. geol. it., 24, 367-386. carbone s., grasso m. & lentini f. (1982 c) elementi per una valutazione degli eventi tettonico-sedimentari dal cretaceo al quaternario nella sicilia sud-orientale. in catalano r. & d’argenio b., eds., guida alla geologia della sicilia occidentale. soc. geol. it., palermo, 103-109. carbone s., grasso m. & lentini f. (1987) lineamenti geologici del plateau ibleo (sicil ia s.e.). presentazione delle carte geologiche della sicilia sud-orientale. mem. soc. geol. it., 38, 127-135. carveni p. & bella d. (1994) aspetti geomorfologici legati ad attività sismica su vulcani attivi: il basso versante orientale dell'etna come modello di studio. boll. acc. gioenia sc. nat., 27 (346), 253-285. carveni p., bella d., filetti g., leonardi m.c., musumeci c. & sturiale g. (1996) zonazione sismica del territorio di giarre (catania) mediante l'analisi di sismi locali avvenuti nel periodo 1855-1989. att. conv. lincei, "la stabilità del suolo in italia: zonazione sismica-frane", 134, 389-393. carveni p., benfatto s., maniscalco r., salleo m. & sturiale g. (2005) controllo tettonico sulla morfologia del basso versante nord-orientale dell’etna (sicilia). il quaternario, in stampa. carveni p., filetti g. & bella d. (1997) aspetti geomorfologici e sismologici connessi a fenomeni di tettonica gravitativa nel basso versante orientale dell'etna. geogr. fis. dinam. quat., 20, 43-49. carveni p., grasso m.f., romano r. & tricomi s. (1991 a) vulcanismo del margine settentrionale ibleo. mem. soc. geol. it., 47, 417-429. carveni p., leonardi a. & romeo m. (1993) rapporti tra vulcaniti submarine e depositi plio-pleistocenici dei dintorni di palagonia (avampaese ibleo, sicilia). boll. acc. gioenia sc. nat., vol. 26, 342, 207-237. carveni p., romano r., capodicasa a. & tricomi s. (1991 b) geologia dell’area vulcanica di capo passero (sicilia sud-orientale). mem. soc. geol. it., 47, 431-447. carveni p. & sturiale g. (1999) fasi tettoniche, fenomeni vulcanici e geomorfologia della zona di monte casale di san basilio, lungo il margine settentrionale dei monti iblei (sicilia orientale). il quaternario, 12 (1), 85-98. casero p., cita m.b., croce m. & de micheli a. (1984) tentativo di interpretazione evolutiva della scarpata di malta basata su dati geologici e geofisici. mem. soc. geol. it., 27, 233-153. cassinis r., cosentino p., ponzini g.s. & riuscetti m. (1970) contributo all’esplorazione geofisica lungo la costa etnea. atti del convegno internazionale sulle acque sotterranee, 6-8 dicembre 1970, palermo, 11 pp. castorina g. (1920) sul terremoto di codavolpe (26 settembre 1920). tipografia "dante alighieri", riposto, 16 pp. continisio r., ferrucci f., & gaudiosi g. (1997) malta escarpment and mt etna: early stages of an asymmetric rifting process? evidences from geophysical and geological data. acta vulcanologica, 9, 45-53. corsaro r.a. & cristofolini r. (2000) subaqueus volcanism in the etnean area: evidence for hydromagmatic activity and regional uplift inferred from the castle rock of aci castello. journ. volc. geoth. res., 95, 209-225. cristofolini r. (1966) le manifestazioni eruttive basiche del trias superiore nel sottosuolo di ragusa. per. min., 35, 1-38. cristofolini r., lentini f., patanè g. & rasà r. (1979) integrazione di dati geologici, geofisici e petrologici per la stesura di un profilo crostale in corrispondenza dell’etna. boll. soc. geol. it., 98, 239-247. cumin g. (1954) il terremoto di codavolpe (versante orientale dell'etna) dell'8 aprile 1950. boll. sed. acc. gioenia sc. nat. catania, s. iv, 2, 473-483. di geronimo i., ghisetti f., lentini f. & vezzani l. (1978) lineamenti neotettonici della sicilia orientale. mem. soc. geol. it., 19, 543-549. di grande a. (1967) i sedimenti pleistocenici del margine settentrionale dell’altipiano ibleo. att. acc. gioenia sc. nat., catania, serie vi, 18 (suppl. sc. geol.), 247-263. di grande a. (1969) l’alternanza neogenico-quaternaria di vulcaniti e sedimenti al margine nord-occidentale dell’altipiano ibleo. att. acc. gioenia sc. nat., catania, 4, 36 pp. di grande a. (1972) geologia dell’area a nord di augusta francofonte (sicilia se). att. acc. gioenia sc. nat., s. 7, 4, 1-32. favalli m., innocenti f., pareschi m.t., pasquarè g., mazzarini f., branca s., cavarra l. & tibaldi a. (1999) the dem of mt. etna: geomorphological and structural implications. geodinamica acta, 12 (5), 279-290. ferrara v. (1975) idrogeologia del versante orientale dell’etna. att. 3° conv. intern. acque sotterranee, 91-144. ferrari l., gardun‚o v.h. & neri m. (1991) i dicchi della valle del bove, etna: un etodo per stimare le dilatazioni di un apparato vulcanico. mem. soc. geol. it., 47, 495-508. ferreri l., azzaro r., bella d., filetti g., michetti a.m., santagati f., serva l. & vittori e. (2000) analisi paleosismologiche ed evoluzione olocenica della fagliazione superficiale lungo la timpa di moscarello, m. etna (sicilia). boll. soc. geol. it., 119 (2), 251-256. finetti i. (1982) structure, stratigraphy and evolution of central mediterranean. boll. geof. teor. appl., 96, 247-312. finetti i., lentini f., carbone s., catalano s. & del ben a. (1996) il sistema appennino meridionale arco calabro sicilia nel mediterraneo centrale: studio geologico-geofisico. boll. soc. geol. it., 115, 529-559. finetti i. & morelli c. (1972) wide scale digital seismic 169sollevamenti a grande scala ... exploration of the mediterranean sea. boll. geof. teor. appl., 14, 291-342. frazzetta g. & romano r. (1978) approccio di studio per la stesura di una carta del rischio vulcanico (etna-sicilia). mem. soc. geol. it., 19, 691-697. frazzetta g. & villari l. (1981) the feeding of the eruptive activity of etna volcano. the regional stress field as a constraint to magma uprising and eruption. bull. volcan., 44 (3), 269-282. gemmellaro c. (1837) sopra il terreno giurassico di sicilia. memoria prima sul terreno giurassico di tauromina. att. acc. gioenia sc. nat., 12, 353375. gemmellaro c. (1858) la vulcanologia dell’etna. la topografia, la geologia, la storia delle sue eruzioni, la descrizione e lo esame de’ fenomeni vulcanici. tipografia dell’accademia gioenia di c. galatola, catania, 267 pp. gemmellaro g.g. (1859) sul graduale sollevamento di una parte della costa di sicil ia dal simeto all’onobola. att. acc. gioenia sc. nat. catania, serie ii, 14, 86-98. ghisetti f. & vezzani l. (1982) the recent deformation mechanism of the calabrian arc. in: mantovani e. & sartoni r. (editors): structure, evolution and present dynamics of the calabrian arc. earth evolution sciences, 3, 197-206. giese p. & morelli c. (1975) crustal structure in italy. in: ogniben l., parotto m. & praturlon a. (editors), structural model of italy: maps and explanatory notes. quad. ricerca sci., 90, 453489. gillot p.y., kieffer g. & romano r. (1994) the evolution of mount etna in the light of potassium-argon dating. acta vulcanologica, 5, 81-87. gironi f. (2003) cosa c’è sotto. quark, 23, 50-57. grassi m. (1865) relazione storica ed osservazioni sull'eruzione etnea del 1865 e su' tremoti flegrei che la seguirono. stabil imento tipografico di crescenzio galatola, catania, 92 pp. gresta s., bella d., musumeci c. & carveni p. (1997) some efforts on active faulting processes (earthquakes and aseismic creep) acting on the eastern flank of mt. etna (sicily). acta vulc., 9 (1/2), 101108. guest j.e., chester d.k. & duncan a.m. (1984) the valle del bove, mount etna: its origin and relation to the stratigraphy and structure of the volcano. jour. volc. geoth. res., 21, 1-23. gvirtsman z. & nur a. (1999) the formation of mount etna as the consequence of slab rollback. nature, 401, 782-785. kieffer g. (1983 a) l’évolution struttural de l’etna (sicile) et les modalités du contrôle tectonique et volcano-tectonique de son activité. faits et hypothèses après les éruptions de 1978 et 1979. rev. géogr. phys. géol. dyn., paris, 24 (2), 129152. kieffer g. (1983 b) dèplacement progressif vers l’est des voies d’alimentation magmatiques de l’etna (sicile). bull. soc. géol. fr., 25 (3), 369-378. kieffer g. & tanguy j.c. (1993) l’etna: évolution structurale, magmatique et dynamique d’un vulcan “poligenic”. mem. soc. géol. france, 163, 253-271. lanzafame g. & bousquet j.c. (1997) the maltese escarpment and its extension from mt etna to the aeolian islands (sicily): importance and evolution of a lithosphere discontinuity. acta vulcanologica, 9, 121-133. lentini f. (1982) the geology of the mt. etna basement. mem. soc. geol. it., 23, 7-25. lentini f., carbone s., cucno c., grasso m., scamarda g. & sciuto f. (1986) carta geologica del settore nord-orientale ibleo (sicilia s.e.). scala 1:50.000, s.e.l.ca., firenze. lo giudice e. (1985) particolari aspetti del rischio sismico nell'area etnea. att. conv. int. assoc. geogr. it.: "l'organizzazione territoriale delle aree sismiche e vulcaniche", 59-85. lo giudice e., patanè g., rasà r. & romano r. (1982) the structural framework of mt. etna. mem. soc. geol. it., 23, 125-158. lo giudice e. & rasà r. (1992) very shallow earthquakes and brittle deformations in active volcanic areas: the etnean region as an example . tectonophysics, 202, 257-268. lyell c. (1859) on the structure of lavas which have consolidated on steep slopes; with remarks on the mode of origin of mt. etna, and on the teory of "center of elevation". phil. trans. roy. soc., 703785. marchesini e., conedera c., morabito g. & macii l. (1964) studio fotogeologico dell'etna. riv. min. sic., 85-87, 83-95. mcguire w.j., stewart i.s. & saunders s.j. (1997) intra-volcanic rifting at mount etna in the context of regional tectonics. acta vulcanologica, 9, 147156. monaco c., petronio l. & romanelli m. (1995) tettonica estensionale nel settore orientale del monte etna (sicilia): dati morfotettonici e sismici. studi geologici camerti, convegno geodinamica e tettonica attiva del sistema tirreno-appennino, 363-374. monaco c., tapponnier p., tortorici l. & gillot p.y. (1997) late quaternary slip rates on the acirealepiedimonte normal faults and tectonic origin of mt. etna (sicily). earth planet. sc. lett., 147, 125139. monaco c. & tortorici l. (1995) tettonica estensionale quaternaria nell’arco calabro e in sicilia orientale . studi geologici camerti, convegno geodinamica e tettonica attiva del sistema tirreno-appennino, 351-362. morelli c. (1970) physiography, gravity and magnetism of the tyrrhenian sea. boll. geofis. teor. appl., 12: 275-305. neri m., gardun‚o v.h., pasquarè g. & rasà r. (1991) studio strutturale e modello cinematico della valle del bove e del settore nord-orientale etneo. acta vulcanologica, 1, 17-24. ogniben l., parotto m. & praturlon a. (1975) structural model of italy. c.n.r., quaderni de “la ricerca scientifica”, 90, 502 pp. patacca e., scandone p., giunta c. & liguori v. (1979) mesozoic paleotectonic evolution of the ragusa zone (se sicily). geol. romana, 18, 331-369. patanè g. (1975) i terremoti di s. m. ammalati e di guardia dell'agosto 1973. riv. min. sic., 154-156, 170 p. carveni et al. 199-206. platania g. (1905 a) su un moto differenziale della spiaggia orientale dell'etna. att. 5° congr. geogr. it., 2, sez. i, scientifica, 214-219. platania g. (1905 b) l’erosione marina all’isola di aci trezza. mem. cl. sc. r. acc. zelanti, s. iii, 5, 3543. platania g. (1908) il terremoto del 7 dicembre 1907. rend. e mem. r. acc. zelanti di acireale, s. 3, 6, 13-20. platania g. (1912) marmitte dei giganti di erosione marina. sunto della comunicazione al x congresso geografico internazionale. 4 pp., tipografia orario delle ferrovie, acireale. platania g. (1915) marmitte dei giganti di erosione marina. att. x congr. int. geografia, 27 marzo-3 aprile 1913, roma, 5 pp. platania g. (1920) terremoto di codavolpe (etna) del settembre 1920. boll. r. osserv. geodin. catania, 8 pp. platania g. (1922) origine dei terrazzi dell’etna. pubbl. ist. geogr. fis. r. univ. catania, (19), 11 pp. platania g. & platania g. (1894) note sui terremoti etnei. rendic. acc. sc. lett. e art. zelanti di acireale, 6, 5 pp. postpischl d., editor (1985) catalogo dei terremoti italiani dall'anno 1000 al 1980. pr. fin. geodin. cnr, quaderni de la ricerca scientifica, 114-2a, bologna. riccò a. (1911) terremoto di fondo macchia del 15 ottobre 1911. boll. sed. acc. gioenia sc. nat. catania, n.s., (19), 6-23. riccò a. (1912) fenomeni geodinamici consecutivi all'eruzione etnea del settembre 1911. boll. soc. sismol. it., 16, 11-32. riuscetti m. & distefano r. (1971) il terremoto di macchia (catania). boll. geof. teor. appl., 13 (51), 150-164. romano r. (1982) succession of the volcanic activity in the etnean region. mem. soc. geol. it., 23, 2748. romano r., lentini f., sturiale c., amore c., atzori p., carter s.r., cristofolini r., di geronimo i., di grande a., duncan a.m., ferrara v., ghisetti f., guest j.e., hamill h., patanè g., pezzino a., puglisi d., schilirò f., torre g. & vezzani l. (1979) carta geologica del monte etna, scala 1:50.000, litogr. art. cartogr., firenze. romano r. & sturiale c. (1981) geologia del versante sud-orientale etneo, f°. 270 iv (no, ne, so, se). boll. soc. geol. it., 100 (1), 11-40. romano r. & sturiale c. (1982) the historical eruptions of mt. etna (volcanological data). mem. soc. geol. it., 23, 75-97. sabatini v. (1914) note sul terremoto di linera dell'8 maggio 1914. boll. r. comit. geol. it., 44, 245293. sartorius von waltershausen w. (1880) der aetna. 2 voll., 371+548 pp., leipzig. scandone p. (1982) geology of the calabrian arc. in: mantovani e. & sartoni r. (editors): structure, evolution and present dynamics of the calabrian arc. earth evolution sciences, 3: 172-180. scarlata m. (1993) l'opera di camillo camiliani. istituto poligrafico e zecca dello stato, libreria dello stato, 686 pp. selli r. & fabbri a. (1971) tyrrhenian: a pliocene deep sea. rend. cl. fis. mat. nat. accad. lincei, 8, 104-116. silvestri o. (1865) relazione sopra i terremoti dell'etna. stabilimento tipografico "la fenice", catania, 12 pp. silvestri o. (1866) sull'eruzione dell'etna del 1865. studii geologici e chimici. "nuovo cimento", tomo xxi-xxii, pisa: 20 pp. silvestri o. (1867) i fenomeni vulcanici presentati dall'etna nel 1863-64-65-66 considerati in rapporto alla grande eruzione del 1865. mem. acc. gioenia sc. nat., 3 (1), 53-319. silvestri o. (1883) sulla esplosione etnea del 22 marzo 1883 in relazione ai fenomeni vulcanici (geodinamici ed eruttivi) presentati dall'etna durante il quadriennio compreso dal gennaio 1880 al dicembre 1883. osservazioni e studi. att. acc. gioenia sc. nat., 3 (18), 237-421. tanguy j.c., condomines m. & kieffer g. (1997) evolution of the mount etna magma: constraints on present feeding system and eruptive mechanism. jour. volc. geot. res., 75, 221-250. van bemmelen r.w. (1969) origin of the western mediterranean sea . verh. k. -ned. geol. mijnbouwkd. genoot., geol. ser., 26, 13-52. zambonini f. (1925) sopra un rapporto del prof. o. de fiore intorno ad un sollevamento delle coste orientali dell’etna. rend. r. acc. sc. fis. e mat., ser. iii, 31, 5 pp. 171 ms. ricevuto il 17 maggio 2005 testo definitivo ricevuto il 21 ottobre 2005 ms. received: may 17, 2005 final text received: october 21, 2005 sollevamenti a grande scala ... imp.boano& pleistocene deformation of the collina di torino inferred from the modelling of their fluvial succession paola boano1, m. gabriella forno2 & stefania lucchesi3 1libero professionista, via asti 13, tonco (at) 2dipartimento di scienze della terra, università di torino 3c.n.r. istituto di geoscienze e georisorse, sez. di torino abstract: boano p., forno g., lucchesi s., pleistocene deformation of the collina di torino inferred from the modelling of their fluvial succession. (it issn 0394-3356, 2004). the modelling of the po plain adjoining the collina di torino by alpine watercourses, now tributaries of the po, is evidence of the extremely recent setting of the present river po. suspended traces of an earlier collector have been preserved on the western and north-western slopes of the collina di torino, where remains of a terraced succession of surfaces with local fluvial deposits can be find out along the present watersheds. differentiation and correlation of the individual surfaces according to their elevation and the alteration degree of their sediments has provided a chronological record of the middle pleistocene-holocene. this succession is the result of the progressive deformation of the distal sectors of the alpine fans involved in the uplift of the collina di torino, which has resulted in deep erosion of the ancient hydrographic pattern as shown by the scarps tens of metres high between the surfaces. it may be supposed that the progressive uplift of the relief and the nw migration of their outer edge brought initially flat areas into the relief and led to a differential deformation of ancient relief forms and deposits of different ages. comparison between the chronology of these surfaces and their distribution within an approximately 400-metres difference of level shows that the rate of uplift from the middle pleistocene to the holocene was of the order of 1mm/yr riassunto: boano p., forno g., lucchesi s., deformazione pleistocenica della collina di torino dedotta dal modellamento della successione fluviale. (it issn 0394-3356, 2004). il modellamento del tratto di pianura padana antistante la collina di torino da parte dei corsi d’acqua alpini, attuali affluenti del f. po, consente di ipotizzare l’impostazione estremamente recente del collettore principale nella pianura piemontese. le tracce di un precedente collettore risultano invece conservate, sensibilmente sospese, sui versanti occidentale e nordoccidentale del rilievo collinare. in questi settori sono osservabili, sulla sommità delle attuali dorsali spartiacque, i relitti di una successione di forme fluviali pianeggianti, a cui sono localmente associati depositi fluviali: i diversi lembi sono stati distinti tra loro e correlati in base alla differente quota e alla diversa alterazione dei sedimenti, consentendo un riferimento cronologico complessivo all’intervallo di tempo compreso tra il pleistocene medio e l’olocene. la successione terrazzata in esame è connessa alla progressiva deformazione del settore distale dei conoidi alpini, coinvolti nel sollevamento della collina di torino: tale deformazione ha comportato un sensibile approfondimento erosionale dell'antico reticolato idrografico evidenziato dal modellamento delle scarpate, con altezza di alcune decine di metri, che separano i diversi lembi terrazzati. il progressivo sollevamento dell’area collinare e la migrazione verso nw del suo margine esterno avrebbero determinato l’inglobamento nel rilievo di aree inizialmente pianeggiati e la deformazione differenziale delle forme e dei depositi riferibili ai diversi intervalli di tempo. in particolare, confrontando il riferimento cronologico dei diversi elementi morfologici e dei sedimenti ad essi associati con la loro distribuzione altimetrica e quindi con il dislivello di circa 400 m che essi presentano, è possibile stimare che tra il pleistocene medio e l’olocene si sia verificato un sollevamento con tasso medio di circa 1 mm/anno. key words: collina di torino, fluvial sediments, deformation, pleistocene. parole chiave: collina di torino, depositi fluviali, deformazione, pleistocene. il quaternario italian journal of quaternary sciences 17(2/1), 2004, 145-150 the terraced fluvial succession previous studies the collina di torino forms a relief that rises to an altitude of some 700 m, 500 m above the adjacent po plain (figs. 1-2). in geological terms, the collina di torino is composed of a succession of eocene to pliocene terrigenous marine sediments that rests on an alpine substratum and has been involved in the apennine deformation. the relief is separated from the plain by buried tectonic structures known as the "padan thrust" (piana & polino, 1994) (fig. 3). the relief and the plain beside it had a different geodynamic evolution: it corresponds for the collina di torino to a marked uplift during the plio-quaternary and for the plain to a moderate lowering in early pliocene and weak to moderate uplift in the middle and late pliocene and quaternary (carraro et al., 1987). the different evolution of these two areas is responsible for considerable changes in the hydrographic pattern during the quaternary. in particular the absence of the po sediments in the present po plain and the wide distribution of the left tributaries sediments point out the absence of this collector during most of the pleistocene (carraro, 1976). on the other hand on the southern slope of the relief and in the adjacent altopiano di poirino are preserved remains of a middle upper pleistocene watercourse with a high discharge (a in fig. 2): this evidence can be ascribed to a previous course of the po river and suggests a deformation of 146 p. boano, m.g. forno & s. lucchesi the area (forno, 1980; 1982; compagnoni & forno, 1992). furthermore, recent preliminary studies on the morphology of the western slope of the relief reveal a middle-upper pleistocene terraced succession of fluvial surfaces with a broad altimetric distribution connected with the deformation of the relief (boano & forno, 1997). this succession suggests the modelling of the western slope by important ancient watercourses (b in fig. 2). locally, on the villa gualino surface, some boreholes have disclosed the discontinuous conservation of lenses of sandy-silty fluvial deposits unconformable with the marine substratum. the results obtained indicate that the succession was shaped by one or more collectors that conveyed the northern alpine rivers, especially with the contribution of the dora riparia (forno et al., 2002). aim of the work and new data the aim of the work is to carry out a geological study of forms and deposits of the terraced succession of the western slope of the collina di torino, to extend the research to the north-western slope and to find a preliminary reconstruction of the recent deformation of the area. difficulties were encountered owing to the loess cover (forno, 1979) and because the area is extensively built up and shows local anthropic modifications. however it was found that the modifications thus introduced are generally confined to the widening of existing surfaces and have not led to the creation of man made surfaces. surveys carried out in the present preliminary study have shown that both slopes carry the remains of a terraced succession of fluvial surfaces modelled in either the tertiary substratum or in a thin cover of fluvial sediments and separated by scarps some tens of metres high (fig. 4). these surfaces are distributed on the western and the north-western slopes in the secondary ridges separating the present valleys. each fluvial surface covers an area of 5,000 200,000 m2; they are widespread at different altitudes between 630 and 240 m a.s.l. and mostly have a n-s or ne-sw trend, parallel to the main watershed. their morphology and distribution have thus no link with the current w or nw drainage fig. 1 geographical location of the collina di torino. inquadramento geografico della collina di torino. fig. 2 former trend of the po river to the south of the collina di torino (a); former path of the watercourse that modelled the terraced succession on the western slope (b). antico percorso del f. po a sud della collina di torino (a); antico andamento del corso d'acqua responsabile del modellamento della successione terrazzata del versante occidentale (b). fig. 3 structural diagram of the piedmont hill reliefs: the northern boundary of the collina di torino is represented by the “padan thrust front” (ptf). legend: a) buried overthrusts; b) strike slip faults; c) anticlinal axes (modified from piana & polino, 1994). the square represents the studied area. schema strutturale dei rilievi collinari piemontesi: il margine settentrionale della collina di torino è delimitato dal “thrust padano” (ptf). legenda: a) sovrascorrimenti sepolti; b) faglie trascorrenti; c) assi di anticlinali (modificato da piana & polino, 1994). il riquadro rappresenta l’area in esame. 147pleistocene deformation of the collina di torino ... fig. 4 transverse cross-section of the western and north-western slopes of the collina di torino (height scale exaggerated). the surfaces are numbered from the most recent and in the upper altimetric sector differentiated between the two slopes (w for the western slope and n for the north-western one). for each surface is shown the most significant toponym together with its altitude and munsell soil colour value. profili trasversali dei versanti occidentale e nordoccidentale della collina di torino, con scala delle altezze esagerata. le diverse superfici sono numerate a partire dalla più recente e differenziate tra i due versanti nella fascia altimetrica superiore (w per il versante occidentale e n per quello nordoccidentale): per ognuna sono precisati il toponimo più significativo, lo sviluppo altimetrico e l’indice di colore del suolo che le caratterizza. fig. 5 simplified longitudinal profile of the terraced succession of the western and north-western slopes. a and b are the upper and lower altimetric sectors. the dashed line indicates a former watershed between the two slopes. the arrows show the drainage direction of the stream net that modelled the succession. surfaces are indicated as in fig. 4. profilo longitudinale semplificato della successione di forme terrazzate dei versanti occidentale e nordoccidentale della collina di torino nelle fasce altimetriche a e b. la linea tratteggiata indica la presenza di un precedente spartiacque tra i due versanti; le frecce indicano la direzione di drenaggio del reticolato idrografico responsabile del modellamento. per le diverse superfici sono indicati gli stessi riferimenti di fig. 4. 148 pattern but are connected with the modelling by ancient watercourses during the uplift of the relief. the surfaces clearly differ in function of their altitude. those at high levels are considerably deformed, and have been remodelled, dissected and mostly deprived of their original fluvial deposits, whereas those located at the lower altitudes are less deformed, more continuous, better preserved, and most have retained their deposits. there is also a difference between the two slopes. the north-western slope displays extensifig. 6 progressive evolution of the stream net that modelled the succession. in the upper altimetric sector (a) there are two watercourses draining in opposite directions, in the lower sector (b) there is only one. the dotted line shows the principal current watershed. the hatched area indicates the former watershed between the two sectors. surfaces are indicated as in fig. 4. evoluzione progressiva del reticolato idrografico responsabile del modellamento della successione terrazzata collinare: nelle fasce altimetriche superiori (a) è rappresentato l’andamento di due corsi d’acqua drenanti in direzione opposta, in quelle inferiori (b) è indicato lo sviluppo di un corso d'acqua unico. la linea tratteggiata rappresenta l’attuale spartiacque principale; l’area tratteggiata corrisponde al precedente settore spartiacque tra i due versanti in esame. per le diverse superfici sono indicati gli stessi riferimenti numerici di fig. 4. p. boano, m.g. forno & s. lucchesi 149 ve terraces, all inclined to the ne, whereas the western slope shows a greater variety of forms corresponding to wide meanders and smaller surfaces inclined in opposite directions (north and south). the altimetric distribution of the terraces on the two slopes is also different (figs. 4 5). the fluvial deposits, where visible, form lenses some metres thick with a clear erosional base. they mainly consist of an unstratified sandy-silty succession, whereas gravelly sediments appear only locally, particularly in the remains of meanders. the pedogenetic evolution of sediments gradually decreases towards the lower surfaces. the munsell colour index of the soils on the substratum and on fluvial deposits ranges from 2.5 yr to 10 yr (figs. 4 5). mapping of the terraces has been followed by their correlation, account being taken of possible changes in the original altimetric setting due to erosion by run-off waters and tectonic deformation. two criteria were used: the pedostratigraphic criterion for the deposits, and the altimetric criterion for the erosional surfaces supporting the fluvial lenses. they both show that there is a clear correlation between the lower terraced surfaces of the two slopes (b in figs. 5-6), but none between the upper surfaces (a in figs. 5 6). conclusions the quaternary evolution of the western and north-western slopes of the collina di torino can be preliminarly deduced from data collected in this study. the preferential n-s and ne-sw trend of the terraces parallel to the main watershed and the fact that their distribution differs from that of the present watercourses suggest that they were shaped by a markedly different hydrographic pattern. although the distribution of the succession is close to the present trend of the po, it cannot be referred to this watercourse because its modelling is roughly contemporary with the passage of the river to the south of the collina di torino (a in fig. 2). in fact application of the local pedostratigraphic scale (arduino et al., 1984) to the soils developed on the examinated fluvial sediments has shown that the entire succession of terraces was formed between the middle pleistocene and the holocene. the upper pleistocene loess cover is in agreement with this chronological reference (forno, 1979). the different morphological features and setting of the upper terraces (a in fig. 5), particularly the differences in the number of surfaces on the two slopes and their dipping (s and ne respectively), suggest that during the lower part of the middle pleistocene the western slope hosted a s-draining and the northwestern slope a ne-draining basin (fig. 6). the same features and inclination of the lower terraces of the two slopes (b in fig. 5) and the same number of surfaces, show that during the upper part of the middle pleistocene the whole area was part of a single basin drained by a ne-flowing watercourse (fig. 6). the particular distribution of the fluvial succession of the collina di torino over a 400 metres difference in elevation is the result of the progressive deformation of the distal sectors of the alpine fans involved in the uplift (fig. 6). the considerably vertical erosion of the relief by the ancient hydrographic pattern in response to the geodynamic activity is responsible for the formation of scarps some tens of metres high between the surfaces, modelled in the tertiary substratum. the erosional surfaces at the base of the deposits, on the other hand, were worn down by lateral erosion episodes associated with local sedimentation that interrupted the dominant erosional trend. in the po plain instead are preserved the proximal sectors of the alpine fans, made of a thicker and weakly terraced or superposed alluvial succession that preserves its original geometry. lateral erosion episodes interrupted by more conspicuous depositional episodes have formed wide erosional surfaces that mark the base of the various sedimentary bodies. the deepening episodes responsible for the low scarps that separate these bodies are reduced with respect to those of the relief. this different behaviour of the plain is the result of its relative stability during the quaternary by contrast with the marked uplift of the collina di torino. the described terraced succession thus came into being in a sector of the po plain that lost its primary shape after its progressive embedding in the relief. this is in agreement with the progressive uplift of the area and the nw migration of the outer buried edge of the relief. it may be supposed that the present tributary watercourses were set up at the same time in these “new” hill sectors. their evolution has been responsible for the cutting off of the originally continuous shapes (surfaces and meanders) linked to the previous collectors and then for their preservation only on the watersheds (fig. 7). some conclusions can also be drawn concerning the rate of the deformation during the quaternary. comparison of the chronological reference of the morphological elements and the associated sediments with their altimetric distribution (difference in level of about 400 m), shows that the rate of uplift between the middle pleistocene and the holocene was of the order of 1 mm/year. fig. 7 view of the terraced surfaces of the superga ridge from valle mongreno: are recognizable three surfaces separated by hight scarps. successione terrazzata della dorsale di superga vista da valle mongreno: sono riconoscibili tre superfici terrazzate separate da alte scarpate. pleistocene deformation of the collina di torino ... 150 this rate is in agreement with the values drawn from the geodetic levellings undertaken in the period 1897-1957 (arca & beretta, 1985), which identify the present maximum uplift values of the entire piedmont area in the collina di torino (> 3 mm/yr). the presence of erosional scarps with different heights in function of their altitude suggests that the uplift was not constant, but characterized by moments of greater or lesser geodynamic activity. for a better definition of the ancient watercourses pattern that modelled the fluvial succession examined, mineralogical and petrographic investigation of the sediments associated is still in progress. acknowledgments the authors would like to thank prof. bartolini for his comments and useful suggestions on a previous draft. lavoro realizzato con il contributo finanziario dell’istituto di geoscienze e georisorse del cnr, sezione di torino. references arca s. & beretta g. (1985) prima sintesi geodeticageologica sui movimenti verticali del suolo nell’italia settentrionale (1897-1957). boll. geod. sc. aff. , 2, 125-156. arduino e., barberis e., carraro f. & forno m. g. (1984) estimating relative ages from ironoxide/total-iron ratios of soils in the western po valley, italy. geoderma, 33, 39-52, amsterdam. boano p. & forno m. g. (1997) evoluzione morfologica quaternaria del versante occidentale della collina di torino. geoitalia, 1° forum fist, bellaria 5-9 ottobre, 1997. riassunti, 2, 221-222. carraro f. (1976) diversione pleistocenica nel deflusso del bacino piemontese meridionale: un’ipotesi di lavoro. gr. st. quat. pad., 3, 89-100. carraro f., forno m. g., ricci b. & valpreda e. (1987) neotectonic map of italy (scale 1: 500.000): foglio 1 in: ambrosetti p., bosi c., carraro f., ciaranfi n., panizza m., papani g., vezzani l. & zanferrari a. (eds.) neotectonic map of italy. c.n.r., progetto finalizzato geodinamica. litografia artistica cartografica, firenze. compagnoni r. & forno m. g. (1992) significato geologico di depositi fluviali ghiaiosi pleistocenici medi nella collina di torino. il quaternario, it. journ. quat. sc., 5, 105-122. forno m. g. (1979) il “loess” della collina di torino: revisione della sua distribuzione e della sua interpretazione genetica e cronologica. geogr. fis. dinam. quatern., 2, 105-124. forno m. g. (1980) evidenza di un drenaggio abbandonato nel settore settentrionale dell'altopiano di poirino (torino). geogr. fis. dinam. quatern., 3, 61-65. forno m. g. (1982) studio geologico dell'altopiano di poirino. geogr. fis. dinam. quatern., 5, 129-162, 1 carta geol. 1: 50.000. forno m. g., ben g., boano p., bocca p., boero v. & compagnoni r. (2002) lembi di depositi fluviali provenienti dai bacini alpini nordoccidentali sulla collina di torino presso villa gualino (nw italy). il quaternario, it. journ. quat. sc., 15, 175-185. piana f. & polino r. (1994) la zona transpressiva di rio freddo e l’evoluzione convergente della collina di torino e del monferrato durante il terziario. atti tic. sc. terra, ser. spec., 1, 167-180. ms. ricevuto il 25 maggio 2004 testo definitivo ricevuto l’8 settembre 2004 ms. received: may 25, 2004 final text received: september 8, 2004 p. boano, m.g. forno & s. lucchesi clima e attività umane come cause dei cambiamenti fluviali il caso del fiume po mauro marchetti dipartimento di scienze della terra università di modena e reggio emilia, largo s. eufemia 19, 41100 modena, italia. e-mail: mauro.marchetti @unimore.it riassunto: marchetti m., clima e attività umane come cause dei cambiamenti fluviali il caso del fiume po (it issn 0394-3356, 2008). i cambiamenti nella dinamica fluviale possono essere imputati a cause diverse; tra queste le principali sono sicuramente quelle climatiche e quelle antropiche. spesso i cambiamenti sono repentini anche se la loro preparazione è avvenuta in tempi molto lunghi; di fatto in queste fasi preparatorie, il sistema fluviale si è avvicinato a soglie limite che una volta superate hanno provocato una brusca accelerazione nei processi di erosione o di sedimentazione fluviale. i più conosciuti effetti sull'ambiente fluviale che si manifestano in queste occasioni sono, infatti, inversioni di tendenza tra fasi di sedimentazione e fasi di erosione. l'incisione o la sedimentazione nei corsi d'acqua dipendono dal rapporto tra portata solida e portata liquida nel fiume pur non dovendosi trascurare altri fattori come ad esempio variazioni del livello di base o cause tettoniche. quando il rapporto è spostato verso la portata solida risulta fondata la possibilità che si verifichino processi di aggradazione, mentre se il rapporto è spostato verso la portata liquida aumentano le probabilità che si manifestino processi erosivi. durante l'evoluzione recente della pianura padana si assiste a momenti contraddistinti da forte sedimentazione, ad esempio quello verificatosi durante l'ultimo massimo glaciale, e da momenti di intensa erosione, come ad esempio ai nostri giorni oppure durante il tardiglaciale. alcuni di questi eventi sono chiaramente influenzati da cause climatiche (fasi glaciali e deglaciazione) altri da cause diverse tra cui quelle antropiche sono spesso preponderanti. in questo lavoro si cercherà di definire alcuni di questi momenti significativi nell'evoluzione postglaciale della pianura padana e di analizzare anche situazioni in cui entrambe le cause si sovrappongono e si mascherano reciprocamente. abstract: marchetti m., climate and human activities as causes of fluvial modifications the case of the po plain. (it issn 03943356, 2008). changes of fluvial dynamics in a plain are due to many causes. it is so difficult to evaluate one as the main cause of the environmental changes in a fluvial plain and in its hydrographic network. rivers, in fact, can suffer rapid and significant changes in their behavior as a consequence of also moderate but extended variations of hydrological parameters that can be recognized only by instrumental measures. perhaps the fluvial system, as many other natural systems, can maintain, between characteristic thresholds, a certain energetic inertia in its behavior. when a threshold is exceeded fluvial processes change quickly and fluvial landforms may be strongly modeled. in the fluvial system events that produce more rapid and disturbing transformations there are those that induce erosion rather than sedimentation. historically in fact, exaggerated sedimentation problems have been impossible to manage during several decades when man has constrained rivers in fixed tracks between narrow embankments. before systematic human management of the fluvial system, aggradation phases spread out into large areas while erosion phases are always concentrated along riverbeds. incision or aggradation depends on ratio solid/water discharge in a riverbed. the more the ratio is unbalanced towards sediment availability, the higher the sedimentation rate is; on the contrary, scarceness sediment availability induces a tendency to erosion. obviously, total discharge and velocity play an important role. in fact a river inclined to erosion processes but characterized by scarce total discharge and velocity is not able to evacuate large gravels or large amounts of sediment in a short time. the present day generalized erosion phases in northern italy are considered the consequence of the growing human impact after the unity of italy. on the contrary in the past, when human impact was less important, fluvial dynamic was principally controlled by natural causes. among them, climatic changes have been the most common cause of fluvial modifications. in the po plain, the climatic change at the end of the last glacial maximum (lgm), which caused the changes in fluvial dynamics, was the last largest formative event. in the northern foothills, late pleistocene palaeochannels indicate several cases of underfit streams among the northern tributaries of the po river. on the other hand, on the southern side of the po plain no geomorphological evidence of similar discharge reduction has been found. here stratigraphic sections, together with archaeological remnants buried under the fluvial deposits, show a reduction in the grain-size of fluvial sediments after the 10th millennium b.c. during the holocene, fluvial sedimentation became finer, and was characterised by minor fluctuation in the rate of deposition, probably related to shorter and less intense climatic fluctuations. given the high rate of population growth and the development of human activities since the neolithic age, human influence on fluvial dynamics, especially since the roman age, prevailed over other factors (i.e. climate, tectonics, vegetation, etc.). during the holocene, the most important changes in the po plain were not modifications in water discharge but in sediment supply. at present, abandonment of the mountainous region leading to reafforestation and artificial control in the mountain sector of the basins but also in-channel quarrying (now illegal but very intense in the 1960s and 1970s) are causing erosion along rivers and large sectors of the adriatic coast. these changes are comparable to those occurring in basins of other mediterranean rivers. parole chiave: erosione fluviale, aggradazione fluviale, pianura padana, variazioni climatiche, impatto antropico. keywords: channel degradation, fluvial aggradation, po plain, climatic change, human impact. il quaternario italian journal of quaternary sciences 21(1b), 2008 241-250 1. introduzione i problemi di erosione fluviale, sono di solito affrontati in modo puntuale, a prescindere dal contesto generale delle dinamiche in atto nell'intero bacino. un'analisi della situazione generale dei corsi d'acqua dimostra in realtà cambiamenti generalizzati nel loro stato idrodinamico in ben determinati momenti della storia geologica recente o ancor più negli ultimi millenni. dagli anni '60, ad esempio, molti corsi d'acqua che scorrono in pianura padana, soprattutto i tributari di destra del fiume po, hanno fatto registrare una sensibile diminuzione del loro carico solido (castiglioni & pell e g r i n i g.b., 2001). a questo proposito, idroser 242 m. marchetti (1983) stima tra gli anni '40 e '70 una riduzione media della torbidità nel po pari all'1% annuo, pur rimanendo invariato il regime dei deflussi liquidi, nonché una riduzione totale del trasporto torbido a mare tra il 1945 (8.4 x 106 m3/anno) e il 1972 (6.4 x 106 m3/anno) del 25%. numerosi studi realizzati nell'ultimo trentennio rilevano tra l'altro, oltre alla sensibile riduzione del trasporto solido totale (pellegrini m., 1969; pellegrini m. et al., 1979; da l ci n, 1983; vi t t o r i n i, 1991), anche una variazione nello spettro granulometrico del sedimento trasportato e una significativa prevalenza del trasporto torbido su quello di fondo idroser (1994). la ragione di questa generalizzata diminuzione nel trasporto solido nei corsi d'acqua registrata dopo la fine della seconda guerra mondiale è stata attribuita a cause prevalentemente antropiche sia dirette (estrazione di inerti dagli alvei, costruzione di dighe e traverse, etc.) sia indirette (sistemazione di bacini montani, riduzione dell'agricoltura nelle aree marginali etc.). le conseguenze di queste azioni si sono dimostrate particolarmente rilevanti, a volte con costi economici considerevoli; in particolare, si è notata una generalizzata tendenza all'approfondimento degli alvei (surian & rinaldi, 2003) che ha compromesso la stabilità di vari manufatti, soprattutto ponti oltre a consistenti erosioni di sponda (fig. 1). più indietro nel tempo, sicuramente prima del progressivo popolamento umano nella pianura padana (almeno dal neolitico), quando le attività umane sul territorio potevano considerarsi trascurabili, le cause dei principali cambiamenti idrodinamici dovevano essere direttamente da ricollegarsi alle variazioni climatiche e, nelle aree più distali della pianura, in parte anche con le variazioni eustatiche comunque a loro volta in parte influenzate dalle variazioni climatiche globali. il passaggio da condizioni climatiche glaciali a condizioni postglaciali ha indubbiamente provocato grandi cambiamenti nel regime idraulico dei corsi d'acqua della pianura padana. tali cambiamenti si possono studiare in termini di corpi sedimentari (guzzetti et al., 1997; avigliano et al., 2002; monegato et al., 2007), soprattutto grandi conoidi alluvionali e forme di erosione, ad esempio i vasti terrazzi in aree interne alla attuale pianura. nel periodo compreso tra il neolitico e l'età moderna si assiste ad un sempre maggiore peso del fattore umano rispetto a quello climatico come responsabile di modificazioni entro i bacini idrografici e conseguentemente anche entro i f iumi stessi. oltre a queste due variabili principali (clima e uomo) dobbiamo ricordare anche la situazione tettonica generale e locale nei vari bacini idrografici che comunque partecipa, seppur con minor intensità, a determinare l'evoluzione idrografica della pianura padana. a questo proposito è sufficiente ricordare la situazione del f. lambro che subisce un'apparente deviazione verso ne rispetto all'andamento naturale degli affluenti di sinistra del f. po verso s e se (pellegrini l. et al., 2003). la presenza di analoghe culminazioni di thrust tuttora in sollevamento poco sotto la superficie della piana è anch'essa responsabile di qualche anomalia nei fiumi dell'emilia orientale e della romagna. in generale, l'influsso tettonico sui grandi cambiamenti idrografici della pianura padana non si manifesta in modo diretto, poiché l'entità dei movimenti in atto risulta lento e facilmente compensato dalle azioni dirette dei corsi d'acqua. 2. le cause di erosione e aggradazione nei corsi d'acqua i corsi d'acqua presentano condizioni energetiche estremamente variabili sia nello spazio e sia nel tempo, per questo risulta difficile identificare tratti soggetti esclusivamente ad azioni erosive o ad azioni di sedimentazione. più spesso nello stesso tratto si alternano fasi di erosione a fasi di sedimentazione e allo stesso modo in tratti adiacenti dello stesso fiume si possono rilevare condizioni idrodinamiche anche alquanto diverse. per questo quando si considera un tratto di corso d'acqua o una sponda dello stesso, potremo asserire che essi sono in erosione o in sedimentazione se nell'arco di un tempo sufficientemente lungo prevale un fenomeno rispetto all'altro. le condizioni responsabili della sedimentazione o dell'erosione in alveo sono direttamente collegate all'energia del corso d'acqua, e quindi fondamentalmente alla cosiddetta stream power (bagnold, 1966; knighton, 1999). la potenza della corrente (stream power) per unità di lunghezza (ω=γqs) è espressa in w/m, sapendo che: γ è il peso specifico dell'acqua in movimento nel canale, q è la portata e s il gradiente di pendio. questa quantità rappresenta l'energia in gioco nei processi fluviali, variabile durante l'anno essenzialmente in rapporto alle diverse portate, velocità e torbidità della massa d'acqua in transito. gli effetti di questa disponibilità di energia si traducono in processi erosivi o deposizionali sulla base di fig. 1 erosione dell'alveo del fiume secchia, poco a valle di sassuolo (modena). channel degradation in the secchia river, downvalley sassuolo (modena). un altro importante fattore costituito dalla quantità di detrito trasportabile effettivamente disponibile. anche questo fattore, teoricamente di semplice definizione è in realtà un parametro difficile da quantificare perchè non indipendente dalla stream power. esso infatti è influenzato da velocità e portata delle acque che fluiscono nel canale, da rapportarsi comunque alla granulometria dei detriti entro il canale. e' inoltre dipendente da svariati altri eventi nell'intero bacino idrografico, nel caso si considerino gli effetti della piovosità, il contributo di detrito verso il canale differisce da corso d'acqua a corso d'acqua in relazione soprattutto alla litologia prevalente, alla morfologia, all'uso del suolo, agli interventi diretti in alveo etc. incrementi generalizzati di portata in un corso d'acqua dovuti ad eventi di natura diversa (variazioni climatiche, azioni dell'uomo etc.) che si manifestano nel bacino di alimentazione, possono portare indistintamente a condizioni di erosione o di sedimentazione generalizzata. allo stesso modo una diminuzione di portata può causare indifferentemente erosione o sedimentazione (starkel, 1983). a questo proposito, il grafico di figura 2 consente, nella sua semplicità, di individuare condizioni di sedimentazione sia durante periodi di portata crescente e sia durante periodi di portate meno abbondanti. allo stesso modo, anche l'erosione può verificarsi durante periodi sia di maggior portata idrica sia di scarsa disponibilità d'acqua. ciò che determina lo spostamento da aggradazione ad erosione o viceversa è il rapporto tra disponibilità di acqua e disponibilità di detrito. se il rapporto si sbilancia verso la portata liquida a discapito della portata solida si manifestano a processi erosivi, mentre se lo sbilancio è a favore della portata solida i processi prevalenti diven243clima e attività umane ... gono di sedimentazione (lane, 1955). stream power e disponibilità di detrito trasportabile sono influenzati sia dalle variazioni climatiche sia dalle attività umane. infatti, l'uomo può agire sulle portate dei fiumi derivando o immettendo nuovi apporti o anche solo regolando il regime degli stessi, può agire sulle pendenze con opportune opere idrauliche (es. le briglie) ma può anche intervenire direttamente sulla disponibilità di detrito ad esempio asportandolo (es. cave in alveo) o agire indirettamente modificando l'uso del suolo su vaste aree del bacino idrografico. in questo ultimo caso si producono cambiamenti che possono assumere aspetti parossistici ma che in realtà discendono da lunghi periodi di quiescenza che servono a raggiungere il disequilibrio e a superare una soglia limite (brunsden, 1993). la trasformazione di aree incolte in aree coltivate, periodicamente scoperte e libere da vegetazione, comporta generalmente un aumento di detrito in grado di affluire ai corsi d'acqua mentre l'abbandono della campagna ma ancora di più della montagna, soprattutto se accompagnato da riforestazione e risistemazione idraulica, diminuisce drasticamente il trasporto solido dei corsi d'acqua. i cambiamenti climatici producono effetti simili essendo in grado di modificare direttamente o indirettamente le portate, la produzione di detrito e la stabilità del detrito nel bacino idrografico. i corsi d'acqua alimentati da calotte glaciali, infatti, tendono ad avere portate formative decisamente maggiori degli stessi fiumi in condizioni non glaciali (ma r c h e t t i, 1990). le stesse condizioni glaciali nel bacino di alimentazione sono in grado di produrre enormi volumi di detrito non comparabili con i processi attivi in periodi di clima temperato. in aggiunta a questo, durante le fasi interglaciali, la crescita più rigogliosa della vegetazione è responsabile di un aumento della resistenza alla mobilità dei detriti disponibili nel bacino. a questo scopo si ricordi che il trasporto solido dei corsi d'acqua tropicali si riduce a ben poca cosa, essendo il materiale coinvolto costituito prevalentemente da sostanza organica e detr it i f inissimi. questi sono in genere il prodotto del dilavamento dei potenti suoli ricchi di minerali argillosi formatisi in conseguenza dei rilevanti processi di alterazione chimica del substrato. 3. i processi di modellamento fluviale a media scala in pianura padana di seguito saranno analizzati tre momenti di intenso disequilibrio registrati negli ultimi 12000 anni. il primo è rappresentato dai cambiamenti ambiental i conseguenti al ritiro dei ghiacciai dopo l 'ult imo massimo glacia le, probabilmente già fig. 2 situazioni di aggradazione (a) ed erosione (e) fluviale, su di un profilo longitudinale in condizioni di equilibrio, al variare del rapporto tra portata solida (qs) e portata liquida (qw) , rispetto alla sinuosità (p). l'erosione si può manifestare sia quando le portate diminuiscono (q-) (cfr. qs > qw) sia quando aumentano (q+) (cfr. qs + < qw +) (modificato da starkel, 1983). aggradation (a) and erosion (e) along the longitudinal profile of a river at change of ratio between bedload (qs) and discharge (qw). p represents sinuosity. erosion occurs when discharge is both lowering (q-) (qs > qw) and growing (q+) (qs + < qw +) (modified from starkel, 1983). durante il tardiglaciale (ra v a z z i et al., in stampa), il secondo intervenuto più gradualmente coevo alla colonizzazione umana della pianura padana a partire dal neolitico e il terzo attualmente in corso e costituito dall'erosione accelerata dei corsi d'acqua a partire dal dopoguerra. l'aumento del popolamento così come i sempre più pesanti interventi umani sul territorio hanno prodotto conseguenze sui corsi d'acqua della pianura padana simili a quanto si può osservare anche in altre aree industrializzate dell'europa sudoccidentale (la nd o n & pi e g a y, 1994; br a v a r d et al., 1997; ri n a l d i & simon, 1998). la pianura padana è la più grande piana alluvionale italiana occupando un'area di circa 46000 km2 (15% del territorio nazionale). e' attraversata dal fiume po, fiume di 652 km che drena un bacino di oltre 75000 k m2. lo studio dell'evoluzione geomorfologica della pianura padana ci rivela diverse fasi di aggradazione avvenute durante più momenti del quaternario, alternate a meno durature crisi caratterizzate da intensi processi di erosione fluviale. tali alternanze di sedimentazioni ed erosioni fluviali sono testimoniate dalla presenza di vaste unità fisiografiche costituite per lo più da estesi terrazzi fluviali di difficile datazione radiometrica per la scarsità di campioni databili in prossimità della superficie, ma ricche di elementi in grado di chiarirne l'evoluzione generale. le superfici più estese che compaiono rispettivamente a nord e a sud del po presentano età differente e quella settentrionale è la più antica (cremaschi & marchetti, 1995). sul bordo settentrionale della pianura padana centrale si affacciano larghi anfiteatri morenici (unità 5 di figura 3) che testimoniano la discesa fino in pianura di imponenti lingue glaciali che si distaccavano dalla grande calotta alpina durante l'ult imo massimo glaciale. l'ultima grande avanza glaciale si manifestò tra 24 e 18 1 4c ka bp (or o m b e l l i, 1983; cr e m a s c h i, 1987; monegato et al., 2007; ravazzi et al., in stampa) mentre dagli appennini nessuna lingua glaciale riuscì a giungere fino in pianura (castiglioni et al., 1997). lungo il bordo della pianura sono presenti superfici terrazzate quasi continue, contraddistinte da suoli rubefatti profondi e inglobanti coperture policicliche di loess (cr e m a s c h i, 1987; 1990). queste superfici sono testimoni sul bordo alpino di piane fluvioglaciali e/o fluviali più antiche e sul bordo appenninico di un penepiano coevo alle precedenti costituito da una serie continua di conoidi fluviali coalescenti (unità 4 di figura 3). 244 fig. 3 schema delle principali unità fisiografiche presenti nella pianura padana centrale: 1) unità delle alluvioni oloceniche, 2) unità tardopleistocenica “bajada pedeappenninica”, 3) unità tardopleistocenica “livello fondamentale della pianura pedealpina”, 4) unità dei terrazzi antichi, 5) unità degli anfiteatri morenici, 6) substrato pre-quaternario. map of the main physiographic units in the central po plain: 1) holocene alluvial unit, 2) late pleistocene “bajada” at the apennine boundary, 3) late pleistocene “livello fondamentale della pianura” (main level of the plain), 4) old terraces, 5) moraine amphitheatres, 6) bedrock. m. marchetti isolati nella piana, emergono inoltre alcuni lembi relitti di tal i superfici (terrazzi isolati di romanengo, casalpusterlengo e, poco ad ovest dell'area rappresentata in figura 3, novara). esternamente alle superfici terrazzate delle unità antiche, si presenta nelle aree della pianura pedealpina una grande unità costituita da m e g a f a n coalescenti (guzzetti et al., 1997) prodotti dalla sedimentazione durante l'ultimo massimo glaciale (ma r c h e t t i, 1992; 1996). la superficie sommitale di tale unità (unità 3 di figura 3), conosciuta in letteratura con il nome di “livello fondamentale della pianura” (petrucci & tagliavini, 1969), è interessata dalla presenza di tracce di antica idrografia sovradimensionata rispetto all'attuale (fig. 4) e da tracce di idrografia abbandonata braided localizzate ben più a meridione di quanto si può riscontrare per l'attuale idrografia (marc h e t t i, 1996; 2001). lungo il bordo appenninico (unità 2 di figura 3), può essere identificata una superficie meno estesa e correlabile in età a quella del “livello fondamentale della pianura” dovuta alla coalescenza di conoidi alluvionali (b a j a d a) accresciutisi principalmente durante le fasi fredde e secche del l'ult imo massimo glaciale. entrambe queste unità risultano interessate da profonde incisioni generatesi durante il tardiglaciale che hanno costretto i principali affluenti del po entro “valli a cassetta” caratterizzate da versanti subverticali, costituiti da scarpate di altezza decrescente da monte a valle (fig. 5). gli affluenti alpini permangono tuttora in tale situazione mentre gli affluenti appenninici, dopo aver subito fasi di sedimentazione olocenica che hanno favorito il colmamento delle precedenti incisioni vallive, hanno cominciato a divagare sulla piana caratterizzando quest'ultima con una fitta rete di dossi fluviali a testimoniare frequenti cambi di tracciato durante l'olocene più recente (ca s t a ldini, 1989; marchetti, 2001). le modalità del la fase di incisione f luviale tardiglaciale devono essere state rapide e drammaticamente intense poiché gli orli di scarpata delle valli a cassetta presentano intatte le curvature di corsi d'acqua sovradimensionati rispetto agli attuali, in generale congruenti con le tracce abbandonate presenti al la superficie del “livello fondamentale della pianura”. le fasi di rapida incisione possono giustificarsi solamente ammettendo un brusco calo di portata solida in concomitanza con scarse variazioni di portata liquida dei fiumi avvenuta durante la deglaciazione. tale situazione deve essersi sviluppata in occasione della liberazione da parte dei ghiacci dei grandi bacini lacustri pedealpini. tali bacini accolsero in questa fase la maggior parte dei sedimenti provenienti dalle aree alpi245 fig. 4 relazione tra la lunghezza d'onda dei meandri (l) espressa in metri e la portata di alveo pieno (qb) espressa in m3/s. le aree grigie indicano il campo di variazione delle portate e delle lunghezze d'onda dei meandri dell'attuale fiume mincio e delle tracce di un suo tracciato tardopleistocenico (modificato da marchetti, 2002). i cerchi rappresentano misure tratte da schumm (1977) mentre la retta è frutto di un'interpolazione proposta da dury (1964). relation between length (metres) of meanders and discharge (cubic metres per second). gray areas represent range of length and discharge of the present r. mincio and of its late pleistocene palaeocourse (modified from ma r c h e t ti, 2002). dots are measures from schumm (1977) while the line is an interpolation due to dury (1964). fig. 5 rappresentazione della pianura mantovana a sud dell'anfiteatro morenico benacense. in evidenza le aree grigie delimitate da scarpate plurimetriche che contraddistinguono la valle a cassetta del mincio e la più piccola valle del tione. map of the northern mantova plain, south of the moraine amphitheatre of l. garda. gray areas, bounded by metric scarps, are the deep valleys of the r. mincio (larger) and r. tione (narrower). clima e attività umane ... ne, abbattendo a valle degli stessi la quantità di detrito trasportabile. per tale motivo tutti i corsi d'acqua che defluiscono da un grande lago prealpino scorrono entro queste profonde valli a cassetta (a volte veri e propri canyon nell'alta pianura) ancora definite a pochi chilometri dalla confluenza in po. i corsi d'acqua che non hanno mai avuto relazione diretta con un bacino lacustre (ad esempio il serio e il mella) non evidenziano tracce evidenti di tale fase d'incisione, similmente a quanto si può intravedere sul lato appenninico della pianura padana. tale situazione si accorda in buona parte con le fasi di aggradazione oloceniche della pianura, fino ad ora ben evidenziate sul lato appenninico (castaldini, 1989; gasperi et al., 1989; bondesan et al., 1995) e da poco individuate anche su quello alpino (de addis et al., 2007). l'influsso antropico comincia ad essere apprezzabile con il neolitico risultando considerevole già a partire dal bronzo medio, da quando la pianura padana comincia a subire disboscamenti sempre più intensi ( sc h n e i d e r, 1985). durante il periodo romano circa il 60% dell'area padana era già deforestata e convertita alle coltivazioni e a partire dal secondo secolo a.c. iniziava la suddivisione agraria centuriale (to z z i, 1972). come conseguenza di questo intensa colonizzazione, i suoli della pianura padana subirono importanti fasi di erosione e infatti la maggior parte di quelli olocenici sono profondi meno di un metro. essi risultano troncati dall'erosione, mostrando a volte i resti basali dell'orizzonte bt argillico più antico su cui si è evoluto un più recente orizzonte a, mentre nella maggior parte dei casi tale orizzonte a è direttamente sovrapposto agli originari depositi non pedogenizzati (fig. 6). l'intensa e generalizzata erosione nei bacini di alimentazione (anche nella parte montana) è registrata anche nei corrispondenti depositi correlativi presenti nel delta del po e nei li toral i del l'al to adriatico in progradazione più spinta rispetto ai secoli precedenti (favero, 1984; bo n d e s a n et al. , 1995). la sedimentazione, forse interrotta o rallentata per un breve periodo in seguito allo spopolamento post romano, riprese intensa in concomitanza di una sopraggiunta fase di maggior umidità (ve gg i a n i, 1974). tale fase di sedimentazione si manifestò soprattutto nelle aree depresse di bassa pianura delimitate da dossi che ne rendevano difficile il drenaggio. alcune aree precedentemente centuriate subirono il seppellimento (cr e m a s c h i et al. , 1980; ravazzi, 1989). nella pianura modenese, le tracce di centuriazione romana appaiono perciò discontinue, ben rappresentate in alcune aree e completamente cancellate dalla superficie in altre ma presenti a profondità variabile, fino a diversi metri (ca r d a r e l l i et al., 2003; 2004). in questa fase storica la causa climatica e quella antropica si distinguono con difficoltà, spesso, infatti, agirono simultaneamente interagendo e mascherandosi vicendevolmente. l'inerzia del sistema fluviale inoltre favorisce il proseguire dei processi in atto anche per molto tempo dopo eventuali variazioni sopraggiunte entro il bacino. ciò contribuisce a rendere ancora più problematica una piena comprensione, non tanto degli effetti, quanto delle cause che regolano la dinamica dei sistemi fluviali nel tempo. e' a partire dal xvi secolo, con l'inizio dell'età moderna che i processi fluviali subiscono pesanti condizionamenti da parte dell'uomo. i fiumi della media e bassa pianura sono infatti tutti costretti entro stretti corridoi arginati che causano una generale aggradazione localizzata e una amplificazione della magnitudine delle piene. ad esempio, la predisposizione di un sistema di argini continuo del fiume po iniziata nel xii secolo si concluse nel xix secolo e prosegue tuttora con continui lavori di sopraelevazione. durante la piccola età glaciale (1550-1850) i processi di aggradazione in pianura divennero più intensi a causa di una maggior quantità di detrito disponibile. la maggior disponibilità di detrito era in parte dovuta ad una seppur lieve maggiore produzione dello stesso in ambiente montano e in modo più significativo ad una maggior capacità degli agenti del modellamento di trasferire i detriti distribuiti lungo le aste fluviali dalle aree più distali, ancora ricche di sedimenti accumulatisi nella maggior parte dei casi durante l'ultimo massimo glaciale (umg), verso i tratti intermedi e prossimali dei corsi d'acqua. a questo proposito si consideri la maggior estensione delle aree glacializzate alpine, l'effetto 246 fig. 6 a sinistra alfisuolo di età tardopleistocenica nell'area di fontanella grazioli (cremona), caratterizzato da un orizzonte argillico di circa 20 cm. a destra suolo di recente formazione sul livello fondamentale della pianura nei pressi di udine. on the left, late pleistocene alfisol near fontanella grazioli (cremona). the argillic horizon is about 20 centimetres. on the right a young soil on the “main level of the plain” near udine. m. marchetti di processi crionivali più intensi e in aree montane più vaste (soprattutto valanghe e frane su ghiaccio), la maggior portata idrica e probabilmente più numerosi processi gravitativi incanalati o sui versanti, assimilabili a debris flow. attualmente molte delle forme individuabili sulla superficie della piana olocenica sono costituite da forme di aggradazione (ca s t a l d i n i, 1989) non più in equilibrio con le attuali condizioni morfoclimatiche. i casi più evidenti sono costituiti dagli attuali corsi d'acqua in forte erosione che percorrono dossi pensili sulla piana circostante. il po ne è l'esempio più significativo poiché negli ultimi decenni ha subito un'incisione di alcuni metri come testimoniato anche dai dati ricavabili dalle sezioni brioschi (fig. 7). in italia centro-settentrionale la tendenza all'approfondimento dei corsi d'acqua è divenuto un serio problema per la gestione dei fiumi a partire dagli anni '60 (pellegrini m. et al., 1979; idroser, 1983; vi t t o r i n i, 1991; ri n a l d i & si m o n, 1998). in particolar modo tutti i tributari di destra del fiume po risentono di una forte erosione in alveo, similmente ai corsi d'acqua dell'emilia romagna e delle marche che sfociano direttamente in adriatico (co l t o r t i, 1997). la scarsità di trasporto solido, responsabile dell'erosione in alveo, si riflette ovviamente anche nei processi costier i. a loro volta, infatti, anche le spiagge dell'adriatico settentrionale risultano in situazione di generalizzata erosione (simeoni & bondesan, 1997). 4. conclusioni l'alternarsi di momenti di aggradazione e di erosione in pianura padana è testimoniata dalla presenza di grandi forme di accumulo di età tardopleistocenica interessate da evidenze di intensa erosione durante la deglaciazione. tali forme sono testimonianza di eventi dominati da cause climatiche. a partire dall'olocene medio i processi fluviali sono influenzati oltre che dalle condizioni climatiche anche all'azione dell'uomo le cui azioni divengono col tempo sempre più intense. la letteratura tende a privilegiare le cause antropiche rispetto a quelle climatiche per spiegare i processi fluviali intervenuti nell'ultimo secolo, probabilmente confondendo cicli evolutivi di medio periodo legati al clima con cicli meno estensi, in grado di mascherare in un lasso di tempo breve gli effetti del ciclo più duraturo. i motivi addotti in letteratura ad esempio per giustificare l'insorgere di intense erosioni post belliche dei corsi d'acqua padani sono stati negli anni passati imputati al prelievo diretto di inerti dall'alveo dei fiumi (roveri, 1960; rossetti, 1970; pellegrini m., 1978) e in misura altrettanto importante al cambiamento d'uso del suolo nel periodo post bellico (ma r c h e t t i, 2002). tali modelli si adattano a quanto è avvenuto nel periodo post-bellico in molti paesi dell'europa occidentale in cui oltre ad una diminuzione dl trasporto torbido si produsse anche una generalizzata attenuazione delle portate di piena (piegay & bravard, 1997). tale effetto fu presumibilmente la conseguenza di un progressivo spopolamento della montagna con progressiva riforestazione dei bacini di ordine inferiore (ro d o l f i, 1988; vi t t o r i n i, 1991) e in misura minore per la realizzazione di bacini montani per la produzione di energia elettrica e per la regimazione delle acque. processi erosivi analoghi, dovuti in gran parte all'intesa azione dell'uomo sono iniziati con qualche decennio di ritardo anche in paesi in cui lo sviluppo economico si sta manifestando impetuosamente in questi anni (rawat & rawat, 1994; sharma, 1996; lu & higgit, 1998). le spiegazioni fino ad ora addotte per giustificare le recenti fasi di incisione fluviale hanno perciò privilegiato fino ad ora la causa antropica su quella climatica. quest'ultima alla luce delle imponenti trasformazioni del territorio e dell'uso del suolo da imputare all'uomo è stata trascurata fino quasi a scomparire dall'elenco delle possibili cause dei processi erosivi entro i fiumi padani. nella realtà le cause antropiche hanno sicuramente accelerato e aggravato una situazione precaria forse già oltre la soglia critica oltre la quale i processi deposizionali si devono tramutare in erosivi. i forti prelievi in alveo sono sicuramente documentati, si pensi ad esempio ai volumi di inerti che in seguito alla ricostruzione post bellica vennero estratti nell'alta pianura mantovana (ba r a l d i & za v a t t i, 1990; am m i n i s t r a z i o n e pr o v i n c i a l e ma n t o v a, 1996), passando da 0,17 x 106 metri cubi anno circa nel decennio 194050 a 1,15 x106 metri cubi anno nel decennio 1980-90 (fig. 8), fino ad una quantità superiore a 2 x 106 metri cubi anno stimati attualmente. analizzando i processi fluviali olocenici in pianura padana appare comunque interessante notare che la ripresa di sedimentazione nella parte distale della piana si attua a partire dal periodo del bronzo, prosegue con 247 fig. 7 sezione di livellazione lungo l'alveo del fiume po presso ostiglia (mantova). le quote sono espresse in metri e l'esagerazione verticale è di 25 volte. la linea puntinata si riferisce alla livellazione del 1873, la tratteggiata a quella del 1954 e la linea continua quella del 1979. topographic sections through the po river near ostiglia (mantova). altitude is exaggerated 25 times and expressed in metres. the dotted line is referred to the 1873 measure, the segmented line to the 1954 measure and continuous line to the 1979 measure. clima e attività umane ... maggior intensità durante il periodo romano e permane attiva ma meno vigorosa fino al periodo bellico. tale situazione si colloca in periodi di intenso popolamento e gestione della pianura durante fasi di miglioramento climatico oltre che nei periodi di spopolamento e mancata gestione post romana del territorio, accoppiata a peggioramenti climatici culminati con la piccola età glaciale. tali momenti di sedimentazione si accordano con quanto documentato anche nei fiumi marchigiani (co lt o r t i, 1997) che appaiono meno soggetti al controllo antropico rispetto a quelli padani. nei fiumi marchigiani si rivela inoltre una tendenza al progressivo approfondimento del profilo longitudinale nonostante si alternino ad intense fasi di erosione anche prolungate fasi di stabilità e/o sedimentazione (fig. 9). in pratica, i momenti di sedimentazione potrebbero definirsi periodi di correzione di un trend erosivo molto più duraturo (millenario) che episodi di sedimentazione plurisecolare non sono in grado di invertire. in tal modo si assiste dalla deglaciazione ad un progressivo deficit di detrito trasportabile che ciclicamente si attenua durante fasi ben definite ma che si traduce nel medio periodo in erosioni generalizzate dei corsi d'acqua. ciò induce a ritenere la supremazia delle cause climatiche come motore dei processi di sedimentazione e d'erosione influenzati fino ad ora solo marginalmente da cause antropiche. la supposta supremazia delle cause antropiche sulle altre è giustificata dal desiderio di assegnare all'uomo un ruolo chiave in grado di condizionare o addirittura sovvertire i processi naturali. in questo caso probabilmente si è rinunciato ad analizzare i processi fluviali in pianura come effetti di cicli di periodo maggiore. i processi condizionati dalle azioni dell'uomo con cicli decennali e secolari hanno perciò mascherato i ben più duraturi cicli naturali. tale situazione potrebbe riconoscersi anche in molti altri processi di modellamento tipici della aree montane dove il detrito accumulato lungo i principali bacini si deve essere principalmente formato durante le f a s i fredde del l ' u l t i m o massimo glaciale e da quel momento ridistribuito da monte verso valle entro tali bacini. in tal modo si può ipotizzare che la produzione di detrito durante l'olocene è limitata e comunque non in grado di compensare i volumi che vengono costantemente evacuati dai vari bacini ad opera dei diversi agenti di modellamento. a tal proposito si auspica uno studio di dettaglio degli accumuli gravitativi che costituiscono le falde e i coni di detrito delle aree più elevate dei bacini idrografici o delle aree soggette all'accumulo dei coni da debris flow per verificare il bilancio di massa nelle aree sorgente durante l'olocene finale. ringraziamenti lavoro eseguito con finanziamento far (fondi ateneo per la ricerca) 2006 dell'università di modena e reggio emilia: ricerche geomorfologiche nelle alpi orientali, nell'appennino emiliano, nella pianura padana centrale e nell'isola di malta. responsabile prof. mauro marchetti. 248 fig. 8 quantità di inerti estratti nell'alta pianura mantovana nei decenni dal 1940 al 1990 in metri cubi anno. amount of gravels and sands extracted in the higher mantova plain from 1940 to 1990 (cubic metres per year). fig. 9 profili longitudinali del tratto finale del fiume musone. la linea continua più marcata rappresenta il profilo al 1997. la linea continua sottile si riferisce al profilo del pleistocene superiore. il tracciato punteggiato è relativo al profilo alla fine del xix secolo, quello a piccolo tratteggio i profili di età romana o precedenti. le frecce indicano la posizione di briglie (modificato da coltorti, 1997). longitudinal profiles of the terminal r. musone (marche region). continuous larger line represents profile of 1997. continuous narrower line represents the profile of late pleistocene. dotted lines represent profiles at the end of 19th century, segmented lines represent profiles of roman age or older. arrows show the location of checkdams (modified from coltorti, 1997). m. marchetti bibliografia am m i n i s t r a z i o n e pr o v i n c i a l e di ma n t o v a (1996) revisione del piano cave provinciale mantova: assessorato programmazione. av i g l i a n o r., ca l d e r o n i g., mo n e g a t o g. & mo z z i p . (2002) the late pleistocene-holocene evolution of the cellina and meduna alluvial fans (friuli, ne italy) mem. soc. geol. it., 57, pp. 133-139. ba g n o l d r.a. (1966) an approach to the sediment transport problem from general physics geological survey prof. paper, 422 (1), pp. 11137. ba r a l d i f. & za v a t t i a. (1990) carta di vulnerabilità degli acquiferi a media scala: ii. la provincia di mantova. in a. zavatti (ed.): studi sulla vulnerabilità degli acquiferi. pitagora, bologna, pp. 83-94. bondesan m., ferri r. & stefani m. (1995) rapporti fra lo sviluppo urbano di ferrara e l'evoluzione idrografica, sedimentaria e geomorfologica del territor i o in vi s s e r tr a v a g l i a.m. (ed.): ferrara nel medioevo topografia storica e archeologia urbana. grafis, bologna, pp. 27-42. br a v a r d j.p., am o r o s c., pa u t o u g., bo r n e t t e g . , bo u r n a u d m., creuze des ch a t e l l i e r s m., gi b e r t j., pe i r y j.l., pe r r i n j.f. & ta c h e t h. (1997) river incision in south-east france: morphological phenomena and ecological effects regulated rivers: research & management, 13, pp. 75-90. br u n s d e n d. (1993) the persistance of landforms zeitschrift für geomorphologie, 93, pp. 13-28. cardarelli a., cattani m., giordani n., labate d., muss a t i r. za n a s i c. (2003) atlante dei beni archeologici della provincia di modena, vol. i, pianura. all'insegna del giglio, firenze, 227 pp. cardarelli a, ca t t a n i m., la b a t e d. & pe l l e g r i n i s . (2004) archeologia e geomorfologia. un approccio integrato applicato al territorio di modena in: ma z z e r i c. (ed.): per un atlante storico ambientale urbano. comune di modena, ufficio ricerche e documentazione sulla storia urbana. nuovagrafica, carpi, pp. 65-77. ca s t a l d i n i d. (1989) evoluzione delle rete idrografica centropadana in epoca protostorica e storica proceedings: insediamenti e viabilità nell'alto ferrarese dall'età romana al medioevo, cento 8-9 may 1987, pp. 115-134. ca s t i g l i o n i g.b. & pe l l e g r i n i g.b. (2001) (eds.) n o t e illustrative della carta geomorfologica del la pianura padana suppl. geg. fis. din. quat., iv, 207 pp. ca s t i g l i o n i g.b., aj a s s a r., baroni c., bi a n c o t t i a . , bondesan a., bondesan m., brancucci g., castald i n i d., ca s t e l l a c c i o e., ca v a l l i n a., co r t e m i g l i a f., co r t e m i g l i a g.c., cr e m a s c h i m., da ro l d o . , elmi c., favero v., ferri r., gandini f., gasperi g., gi o r g i g., ma r c h e t t i g., ma r c h e t t i m., ma r o c c o r., me n e g h e l m., mo t t a m., ne s c i o., or o m b e l l i g., pa r o n u z z i p., pe l l e g r i n i g.b., pe l l e g r i n i l . , ri g o n i a., so m m a r u g a m., so r b i n i l., te l l i n i c . , tu r r i n i m.c., va i a f., ve r c e s i p.l., ze c c h i r. & zo r z i n r. (1997) carta geomorfologica della pianura padana 3 sheets, 1:250.000 scale. selca, firenze. coltorti m. (1991) modificazioni morfologiche oloceniche nelle pianure alluvionali marchigiane: alcuni esempi nei fiumi misa, cesano e musone geog. fis. dinam. quat., 14 (1), pp. 73-86. coltorti m. (1997) human impact in the holocene fluvial and coastal evolution of the marche region, central italy catena, 30, pp. 311-335. cr e m a s c h i m. (1987) paleosols and vetusols in the central po plain (northern italy) ed. unicopli, studi e ricerche sul territorio, milano, 28, 305 pp. cr e m a s c h i m. (ed.) (1990) the loess in northern and central italy: a loess basin between the alps and the mediterranean region quad. geodinamica alpina e quaternaria, 1, 187 pp. cremaschi m. & marchetti m. (1995) changes in fluvial dynamics in the central po plain (italy) between lateglacial and early holocene in: fr e n z e l b . (ed.): european river activity and climatic change during the lateglacial and early holocene . palaeoclimate research / paläoklimaforshung, 14, pp. 173-190. cremaschi m., bernabò brea m., tirabassi j., d'agostini a., dall'aglio p., magri s., marchesini a. & nepoti s. (1980) l'evoluzione della pianura emiliana durante l'età del bronzo, l'età romana e l'alto medioevo: geomorfologia ed insediamenti padusa, 16 (1), pp. 53-158. dal cin r. (1983) i litorali del delta del po e alle foci dell'adige e del brenta: caratteri tessiturali e deposizione dei sedimenti, cause dell'arretramento e previsioni sull'evoluzione futura boll. soc. geol. it., 102, pp. 9-56. da l l' ag l i o p, ma r c h e t t i g., pe l l e g r i n i l., ne s c i o . , savelli d. & calderoni g. (2004) geomorfologia e popolamento antico nella media valle del fiume cesano (marche italia) il quaternario, 17(2/1), pp. 213-220. de a d d i s m., do n e g a n a m., pi n i r., ra v a z z i r., wi c k l . , de amicis a., marchetti m. & monegato m. (2007) the onset of the last glacial maximum in northern italy: chronostratigraphical and palaeoecological evidences from alluvial plain and lacustrine successions geophysical research abstracts, 9, 11648. dury g.h. (1964) principles of underfit streams us geol. surv. prof. paper, 452-a, pp. 1-67. fa v e r o v. (1984) evoluzione delle linee di costa dell'alto adriatico in: aspes a. (ed.) . banca pop. verona, 53-68. ga s p e r i g., cr e m a s c h i m., ma n t o v a n i ug u z z o n i m . p . , ca r d a r e l l i a., ca t t a n i m., & la b a t e d. (1989) evoluzione plio-quaternaria del margine appenninico modenese e dell'antistante pianura. note illustrative alla carta geologica mem. soc. geol. it., 39, pp. 375-431. gu z z e t t i f., ma r c h e t t i m. & re i c h e n b a c h p. (1997) large alluvial fans in the north-central po plain (northern italy) geomorphology, 1 8, pp. 119136. idroser (1983) il trasporto solido fluviale nei bacini tributari dell'adriatico regione emilia romagna, piano progettuale per la di fesa della costa emiliano-romagnola, 429 pp. idroser (1994) aggiornamento e integrazione del piano progettuale per la difesa della costa adriatica emiliano-romagnola regione emilia-roma249clima e attività umane ... gna. relazione generale, 276 pp. knighton a.d. (1999) downstream variation in stream power geomorphology, 29, pp. 293-306. la n d o n n. & pi e g a y h. (1994) l'incision d'affluents méditerranéens du rhône, la drôme et l'ardèche riv. géogr. lyon, 69(1), pp. 63-72. lane e.w. (1955) the importance of fluvial morphology in hydraulic engineering am. soc. civil eng. proc., 81 (1), pp. 1-17. lu x. & hi g g i t d.l. (1998) recent changes of sediment yield in the upper yangtze, china environmental management, 22, pp. 697-709. marchetti m. (1990) cambiamenti idrologici nella pianura padana centrale a nord del fiume po i casi di "underfit streams" dei fiumi mincio, oglio e adda geog. fis. dinam. quat. 13(1), pp. 53-62. ma r c h e t t i m. (1992) geomorfologia ed evoluzione recente della pianura padana centrale a nord del fiume po phd thesis, milano university, 164 pp. marchetti m. (1996) variazioni idrodinamiche dei corsi d'acqua della pianura padana centrale connesse con la deglaciazione il quaternario, 9 ( 2 ), pp. 465-472. marchetti m. (2001) forme e depositi fluviali, fluvioglaciali, lacustri. in: castiglioni g.b. & pellegrini g.b. (eds.): note illustrative della carta geomorfologica della pianura padana suppl. geg. fis. din. quat., iv 2001, pp. 73-104. ma r c h e t t i m. (2002) environmental changes in the central po plain (northern italy) due to fluvial modifications and man's activi t ies geomorphology, 44(3-4), pp. 361-373. monegato g., ravazzi c., donegana m., pini r., calder o n i g. & wi c k l. (2007) evidence of two-fold glacial advance during the last glacial maximum in the tagliamento end moraine (eastern alps) quaternary research, 68(2), pp. 284-302. orombelli g. (1983) il pleistocene superiore in italia geog. fis. dinam. quat., 6, pp. 174-195. pellegrini l., boni p. & carton a. (2003) hydrographic evolution in relation to neotectonics aided by data processing and assessment: some examples from the northern apennines ( italy) quaternary international, 101-102, pp. 211-217. pe l l e g r i n i m. (1969) la pianura del secchia e del panaro atti soc. nat. e mat. di modena, 100, pp. 1-50. pe l l e g r i n i m. (1978) riflessi idrogeologici dell'attività estrattiva di materiali inerti in alveo ed extra-alveo nel le aree di conoide proc. conf. on, pp. “attività estrattive dei materiali inerti da costruzioni; effetti sugli ambienti e risorse alternative, cavriago, 6 pp. pe l l e g r i n i m., pe r e g o s. & ta g l i a v i n i s. (1979) l a situazione morfologica degli alvei degli affluenti emiliani del po. mucchi, modena, 9 pp. petrucci f. & tagliavini s. (1969) note illustrative della carta geologica d'italia, foglio 61, cremona geol. surv. of italy, roma, 43 pp. pi e g a y h. & br a v a r d j.p. (1997) response of mediterranean riparian forest to a 1 in 400 year flood, ouveze river, drome-vaucluse, france earth surf. processes and landforms, 22, pp. 31-43. ra v a z z i c. (1989) analisi polliniche del riempimento del fossato. dati paleoecologici sulle variazioni ambientali in: bernabò brea m. & cremaschi m. (eds.): la terramara di poviglio. coopsette, reggio emilia, pp. 31-36. ravazzi c., peresani m., pini r. & vescovi e. (in stampa) il tardoglaciale nelle alpi e in pianura padana. evouzione stratigrafica, storia della vegetazione e del popolamento antropico. il quaternario, 10(2). rawat j.s. & rawat m.s. (1994) accelerated erosion and denudation in the nana kosi watershed, central himalaya, india. part i: sediment load mountain research and development, 14, pp. 25-38. rinaldi m. & simon a. (1998) bed-level adjustments in the arno river, central italy geomorphology, 22, pp. 57-71. rodolfi g. (1988) geomorphological mapping applied to land evaluation and soil conservation in agricultural planning. some examples from tuscany (italy) z. geomorph. n.f., 68, pp. 155-174. ro s s e t t i m. (1970) la decadenza morfologica degli alvei dei corsi d'acqua della regione padana il frantoio, 4, pp. 29-42. roveri e. (1960) indagine sulle cause che hanno provocato il cedimento del ponte sul secchia della via emilia a rubiera asfalti, bitumi, catrami, 29(6), pp. 7-9. sc h n e i d e r r. (1985) palynologic research in the southern and souteastern alps between torino and trieste dis. bot., 87, pp. 83-103. schumm s.a. (1977) the fluvial system wiley & sons, new york. sharma k.d. (1996) soil erosion and sediment yield in the indian arid zone in: wa l l i n g d.e. & we b b b.w. (eds.): erosion and sediment yield: global and regional perspective. proceedings of intern ass. hydrol. sciences, 15-19 july 1996. iahs, 236, pp. 175-182 simeoni u. & bondesan m. (1997) the role and responsability of man in the evolution of the italian adriatic coast bull. inst. oceanographique, 1 8, pp. 111-132. starkel l. (1983) the reflection of hydrologic changes in the fluvial environment of the temperate zone during the last 15.000 years in gregory k.j. (ed.) background to palaeohydrology. wiley & sons, pp. 213-235. surian n. & rinaldi m. (2003) morphological response to river engineering and management i alluvial channels in italy geomorphology, 5 0, pp. 307326. to z z i p. (1972) storia padana antica, il territorio fra adda e mincio ceschina ed., milano, 173 pp. veggiani a. (1974) le variazioni idrografiche del basso corso del fiume po negli ul timi 3000 anni padusa, 1-2, pp. 39-60. vittorini s. (1991) la diminuzione del trasporto torbido nei fiumi italiani tra il periodo prebellico e quello attuale geog. fis. dinam. quat., 14(2), 251-258. 250 m. marchetti ms. ricevuto il 23 novembre 2007 testo definitivo ricevuto il 18 aprile 2008 ms. received: november 23, 2007 final text received: april 18, 2008 imp.lirer_iaccarino lo sviluppo e il futuro della time scale del neogene: un breve riassunto fabrizio lirer1 & silvia iaccarino2 1istituto per l'ambiente marino costiero (iamc) cnr sede di napoli, calata porta di massa, interno porto di napoli, 80133 napoli. e-mail: <fabrizio.lirer@iamc.cnr.it> 2dipartimento di scienze della terra, università di parma, parco area delle scienze, 157 a, 43100 parma. abstract: f. lirer & s. iaccarino, development and future of the neogene time scale: a brief summary. during the last years, much progress has been made in the standardization of the neogene global chronostratigraphic scale by defining gssps. all late neogene stage boundaries are by now defined in astronomically or paleomagnetically tuned land-based marine sections in the mediterranean. at present, seven gssps are formally defined: base of the pleistocene (neogene/quaternary boundary), base of the gelasian, base of the piacenzian, base of the zanclean (miocene/pliocene boundary), base of the messinian, base of the tortonian, base of the neogene (oliogocene/miocene boundary) and the definition of the gssp of the serravallian is submitted. parole chiave: neogene, mediterraneo, gssp. keywords: neogene time scale, mediterranean, gssp. il quaternario italian journal of quaternary sciences 21(1a), 2008 17-22 la geological time scale (gts) rappresenta la principale sintesi di dati stratigrafici (magneto-bio-cronostratigrafici) derivanti da studi su depositi marini. la complessità nella creazione della time scale risiede principalmente nella difficoltà di utilizzare la grande quantità di dati presenti nella letteratura scientifica, derivanti da studi che non necessariamente avevano come obiettivo la cronologia. il concetto tempo e la sua definizione rappresenta il punto chiave che ha modificato profondamente la visione della time scale classica di berggren et al. (1985) e di harland et al. (1990). nella scala tempo di berggren et al. (1985) la cronologia avveniva attraverso la correlazione dei vari bioeventi con la geomagnetic polarity time scale (gpts) calibrata in area oceanica con l'ausilio di pochi livelli datati con metodi radiometrici. e' chiaramente ovvio che il grado di affidabilità e/o di precisione dei dati presenti nella scala tempo varia molto, specialmente in relazione allo sviluppo di tecniche di datazione che attualmente hanno raggiunto un grado di alta precisione. all'inizio degli anni '90 i lavori pionieristici di hilgen (1991a, b) e shackleton et al. (1990), hanno mutato profondamente il concetto di tempo nella gts. si deve infatti a loro attraverso studi ad alta risoluzione, l'introduzione della ciclostratigrafia applicata per fini geocronologici, hilgen per l'area mediterranea e shackleton per l'ambiente oceanico. la validità di questi studi è stata tale che i dati prodotti sono stati immediatamente adottati nella gts da berggren et al. (1995) per l'intervallo temporale relativo al pliocene e al pleistocene. uno dei principali pregi della ciclostratigrafia è quello di valutare con maggiore precisione e affidabilità il grado di sincronia o diacronia degli eventi biostratigrafici, che rappresentano la base della scala tempo. negli ultimi venti anni la letteratura scientifica basata su studi ciclostratigrafici ad alta risoluzione per l'intervallo compreso tra il pleistocene e il miocene medio (hilgen, 1991a,b; hilgen et al., 1999, 2000a,b, 2003, 2006; hilgen & krijgsman 1999; sierro et al., 2001, 2003; aziz et al., 2003, 2004, 2007; iaccarino et al. 2004; krijgsman et al. 2002, 2004; abels et al., 2005; husing et al., 2007), su sedimenti marini e continentali del mediterraneo, hanno dimostrato che l'accuratezza e la precisione della classica magneto-bio chronostratigraphic scale poteva e doveva essere migliorata. l'applicazione della ciclostratigrafia ha portato alla costruzione della astronomical time scale (ats) per parte del neogene che è oggi evoluta nella astronomical tuned neogene time scale (atnts2004) (lourens et al., 2004), presentata durante l’international geological congress 2004 a firenze, che è più accurata e più precisa delle precedenti time scale. il principale risultato del continuo evolversi della time scale è la definizione del global stratotype section and point (gssp), la base del pleistocene (aguirre e pasini 1985) (fig. 1), dei piani gelasiano (pliocene superiore, rio et al., 1998) (fig. 1), piacenziano (pliocene medio, castradori et al.,1998) (fig. 1), zancleano (pliocene inferiore, van couvering et al., 2000) (fig. 1), messiniano, il piano più giovane del miocene (miocene superiore, hilgen et al., 2000b) (fig. 2), tortoniano (miocene superiore, hilgen et al., 2005) (fig. 2), della 18 f. lirer, s. iaccarino fig. 1 a: sezione della vrica (calabria). la linea tratteggiata indica la posizione del gssp della base del pleistocene in corrispondenza del ciclo di insolazione i-176; b: sezione di monte s. nicola (sicilia). la linea tratteggiata indica la posizione del gssp del gelasiano in corrispondenza del nicola bed. b1: dettaglio della sezione di monte s. nicola con la posizione del nicola bed in corrispondenza del ciclo di insolazione ì-250; c: sezione di punta piccola (sicilia). la linea tratteggiata indica la posizione del gssp della base del piacenziano; d: sezione di eraclea minoa (sicilia). la linea tratteggiata indica la posizione del limite messiniano/zancleano. d1: la freccia indica la posizione del gssp dello zancleano. a: vrica section (calabria). the dashed line indicates the position of the pleistocene gssp in correspondence of insolation cycle i-176; b: monte s. nicola section (sicily). the dashed line indicates the gelasian gssp in correspondence of the nicola bed. b1: position of nicola bed in correspondence of insolation cycle i-250; c: punta piccola section (sicily). the dashed line indicates the piacenzian gssp; d: eraclea minoa section (sicily). the dashed line indicates the messinian/zanclean boundary. d1: the arrow indicates the zanclean gssp. 19lo sviluppo e il futuro della time scale... fig. 2 e: sezione di qued akrech (marocco). la linea tratteggiata indica la posizione del gssp del messiniano; f. sezione di monte dei corvi (conero, marche). la linea tratteggiata indica la posizione del gssp del tortoniano in corrispondenza del ciclo 76; g: sezione di ras il pellegrin (malta). la linea tratteggiata indica la posizione del gssp del serravalliano; h: sezione di lemme-carrosio (sud piemonte, italia). la linea tratteggiata indica la posizione del gssp della base del neogene. e: qued akrech section (morocco). the dashed line indicates the messinian gssp in correspondence of insolation cycle i-176; f: monte dei corvi section (conero, marche). the dashed line indicates the tortonian gssp in correspondence of cycle 76; g: ras il pellegrin section (malta). the dashed line indicates the serravallian gssp; h: lemme-carrosio section (southern piedmont, italy). the dashed line indicates the gssp for the base of the neogene. 20 f. lirer, s. iaccarino base del neogene (miocene inferiore, steininger et al., 1995) (fig. 2) e più recentemente i l gssp del serravalliano (fig. 2) che è stato approvato dalla subcommission neogene stratigraphy (sns) e recentemente ratificato dalla international commission on stratigraphy (ics). per quanto riguarda la base del langhiano (miocene inferiore), f. hilgen (quale presidente della subcommision neogene stratigraphy) ha indicato come possibile sezione per il gssp del langhiano la sezione della la vedova (monti del conero, marche) attualmente in studio da iaccarino e collaboratori (web-site della commissione internazionale di stratigrafia http://www.stratigraphy.org). la base del burdigaliano è ancora un oggetto sconosciuto. e' in essere un progetto nazionale prin (responsabile prof.ssa silvia iaccarino) finalizzato al reperimento di sezioni che potenzialmente possono avere i requisiti per la definizione del gssp del burdigaliano. oggi nella letteratura scientifica e nelle varie versioni della time scale sono proliferate versioni, più o meno rigorose, di schemi biostratigrafici a foraminiferi planctonici e a nannofossili calcarei. come noto gli schemi biostratigrafici adottati in oceano non sono utilizzabili per il neogene del mediterraneo, e se nel primo caso gli schemi adottati sono fortemente accettati dalla comunità scientifica internazionale (anche se recentemente turco et al. 2002, ha dimostrato che nel miocene medio anche in oceano ci sono molti problemi nell'applicazione dei vigenti schemi biostratigrafici a foraminiferi planctonici), nel secondo caso, non esiste un generale consenso. e' attualmente in corso una revisione della time scale per il neogene, sotto l'egida della regional committee on mediterranean neogene stratigraphy (rcmns), che rappresenta uno dei documenti conclusivi del progetto europeo “environments and ecosystem dynamics of the eurasian neogene” (eeden) sponsorizzato dalla european science foundation. global stratotype section and point's (gssp’s) del neogene base del pleistocene (aguirre e pasini 1985) 1.800 ma base del gelasiano (pliocene superiore, rio et al., 1998) 2.588 ma base del piacenziano (pliocene medio, castradori et al.,1998) 3.600 ma base del zancleano (pliocene inferiore, van couvering et all., 2000) 5.332 ma base del messiniano (miocene superiore, hilgen et al., 2000b) 7.251 ma base del tortoniano (miocene superiore, hilgen et al., 2005) 11.600 ma base del serravalliano (miocene medio, hilgen et al., submitted) 13.820 ma base del neogene (miocene inferiore, steininger et al., 1995) 23.030 per il geological congress di oslo del 2008 era prevista (gradstein e ogg, 2004) la definizione dei gssps di tutti i piani del neogene. purtroppo il langhiano ed il burdigaliano sono ancora in studio. bibliografia abels h.a., hilgen f.j., krijgsman w., kruk r.w., raffi i., turco, e., zachariasse w.j., 2005. long-period orbital control on middle miocene global cooling: integrated stratigraphy and astronomical tuning of the blue clay formation on malta, paleoceanography, 20, pa4012, doi 10.1029/2004pa001129, 11 pp. aguirre e., and pasini g., 1985. the pliocenepleistocene boundary. episodes, 8, pp. 116-120. abdul aziz h., krijgsman w., hilgen f. j., wilson d. s., and calvo j. p. (2003a). an astronomical polarity timescale for the late middle miocene based on cyclic continental sequences. journal of geophysical research, 108, no. b3, 2159, doi:10.1029/2002jb001818, abdul aziz h., van dam j., hilgen f.j., wout krijgsman (2004). astronomical forcing in upper miocene continental sequences: implications for the geomagnetic polarity time scale. earth and planetary science letters 222, pp. 243258. abdul aziz h., di stefano a., foresi l. m., hilgen f.j., iaccarino s. m., kuiper k.f., lirer f., salvatorini g. and turco e. (2007). integrated stratigraphy and40ar/39ar chronology of early middle miocene sediments from dsdp leg 42a, site 372 (western mediterranean). palaeogeography, palaeoclimatology, palaeoecololy, 257, pp. 125-138. berggren w.a., kent d.v., van couvering j.a., (1985). the neogene: part 2. neogene geochronology and chronostratigraphy. in: snelling, n.j. (ed.), the chronology of the geological record, geol. soc. lond. mem., 10, pp. 211 -260. berggren w.a., kent d.v., swisher c.c., aubry m.-p., 1995. a revised cenozoic geo¬chronology and chronostratigraphy. in: geochronology, time scales and global stratigraphic correlation, sepm spec. publ., 54, pp. 129-212. castradori d., rio d., hilgen f.j. and lourens l.j., 1998. the global standard stratotype-section and point (gssp) of the piacenzian stage (middle pliocene). episodes, 21, pp. 88-93. gradstein f.m. and ogg j.g. (2004). geological time scale 2004why, how and where next!. lethaia 37 (2), pp. 175-181. krijgsman w., blanc-valleron m.m., flecker r., hilgen f. j., kouwenhoven t.j., merle d., orszagsperber, f. and rouchy, j.-m., 2002. the onset of the messinian salinity crisis in the eastern mediterranean (pissouri basin, cyprus). earth and planetary science letters, 194, pp. 299-310. krijgsman w., gaboardi s., hilgen f.j., iaccarino s., de kaenel e., and van der laan e. (2004). revised astrochronology for the ain el beida section (atlantic morocco): no glacio-eustatic control for the onset of the messinian salinity crisis. stratigraphy, 1, no. 1, pp. 87-101. harland et al., a geologic time scale, cambridge university press, 1982. harland et al., a geologic time scale 1989, cambridge university press, 1990 hilgen f.j., 1991a. astronomical calibration of gauss to matuyama sapropels in the mediterranean and implication for geomagnetic polarity time scale. earth and planetary science letters, 104, pp. 226244, amsterdam. hilgen f.j., 1991b. extension of the astronomically calibrated (polarity) t ime scale to the miocene/pliocene boundary. earth and planetary science letters, 107, pp. 349-368, amsterdam. hilgen f.j., abdul aziz h., krijgsman w., langereis c.g., lourens l.j., meulenkamp j.e., raffi i., steenbrink j., turco e., van vugt n., wijbrans j.r., and zachariasse w.j., 1999, present status of the astronomical (polarity) time-scale for the mediterranean late neogene. phil. trans. royal soc. london a, 357, pp. 1931-1947. hilgen f., brinkhuis h., zachariasse w.j. (2006). unit stratotypes for global stages: the neogene perspective. earth-science reviews 74, pp. 113125. hilgen f.j., iaccarino s., krijgsman w., montanari a., raffi i., turco e. and zachariasse w.j., (2003a). the global stratotype section and point (gssp) of the tortonian stage (upper miocene): a proposal. submitted to the international union of geological sciences, international commission on stratigraphy, subcommission on neogene stratigraphy. hilgen f.j., iaccarino s., krijgsman w., villa g., langereis c.g., and zachariasse w.j., 2000b. the global boundary stratotype and point (gssp) of the messinian stage (uppermost miocene). episodes, 23 (3), 1-6. hilgen f.j., kri jgsman w., raffi i., turco e., zachariasse w.j., (2000a). integrated stratigraphy and astronomical calibration of the serravallian/ tortonian boundary section at monte gibliscemi, sicily, marine micropaleontology, 38, pp. 181-211. hilgen f.j., abdul aziz h., krijgsman w., raffi i., turco e., 2003. integrated stratigraphy and astronomical tuning of the serravallian and lower tortonian at monte dei corvi (middle-upper miocene, northern italy), palaeogeography, palaeoclimatology, palaeoecology, 199, pp. 229-264. hilgen f.j., & krijgsman w. (1999). cyclostratigraphy and astrochronology of the tripoli diatomite formation (pre-evaporite messinian, sicily, italy). terra nova, 11, pp. 16-22. hüsing s.k., hilgen f.j., abdul aziz h., w. krijgsman (2007). completing the neogene geological time scale between 8.5 and 12.5 ma. earth and planetary science letters 253, pp. 340-358. iaccarino s.m., lirer f., bonomo s., caruso a., di stefano a., di stefano e., foresi l.m., mazzei r., salvatorini g., sprovieri m., sprovieri r., turco e., 2004. astrochronology of middle miocene mediterranean sections. in cyclostratigraphy: approaches and case histories, sepm, spec. publ., 81, 27-44. lourens l.j., hilgen f.j., laskar j., shackleton n.j., wilson d., 2004. the neogene period. in: gradstein f.m., j.g. ogg, and a.g. smith. a geologic time scale, cambridge univ. press, pp. 409-440. rio d., sprovieri r., castratori d., and di stefano e., 1998. the gelasian stage (upper pliocene): a new unit of the global standard chronostratigraphic scale. episodes, 21, pp. 82-87. shackleton n.j., berger a., and peltier w.r., 1990. an alternative astronomical calibration of the lower pleistocene timescale based on odp site 677. trans. roy. soc. edin., 81: 251-261. sierro f.j., flores j.a., francés g., vàzquez a., utrilla r., zamarreno i., erlenkeuser h., barcena m.a., 2003. orbitally-controlled oscillations in plaktic communities and cyclic changes in western mediterranean hydrography during the messinian. palaeogeography, palaeoclimatology, palaeoecology, 190, pp. 289-316. sierro f.j., hilgen f.j., krijgsman w., and flores j.a., 2001. the abad composite (se spain): a messinian reference section for the mediterranean and the apts. palaeogeography, palaeoclimatology, palaeoecology, 168, pp. 141-169. steininger f.f., aubry m.p., berggren w.a., biolzi m., borsetti a.m., cartlidge j.e., cati f., corfield r., gelati r., iaccarino s., napoleone c., ottner f., rogl f., roetzel r., spezzaferri s., tateo f., villa g., and zevenboom d., 1997. the global stratotype section and point (gssp) for the base of the neogene. episodes, 20, pp. 23-28. turco e., bambini a.m., foresi l.m., iaccarino s., lirer f., mazzei r., salvatorini g., 2002. middle miocene high resolution calcareous plankton biostratigraphy at site 926 (leg 154, equatorial atlantic ocean): paleoecological and paleoceanographic implications, geobios, mem. spec., 24, pp. 257-276. van couvering j.a., castradori d., cita b.m., hilgen f.j. and rio d., 2000. the base of the zanclean stage and of the pliocene series. episodes, 23, pp. 179-187. 21lo sviluppo e il futuro della time scale... ms. ricevuto il 2 aprile 2008 testo definitivo ricevuto il 17 aprile 2008 ms. received: april 2, 2008 final text received: april 17, 2008 imp.bertoldi& first remarks on late pleistocene lacustrine deposit in the berceto area (northern apennines, italy) remo bertoldi1, alessandro chelli2, rachele roma1, claudio tellini2 & paolo vescovi2 1dipartimento di biologia evolutiva e funzionale, università degli studi di parma, parco area delle scienze, 11/a, 43100 parma. 2dipartimento di scienze della terra, università degli studi di parma, parco area delle scienze, 157/a, 43100 parma. abstract: bertoldi r. et al., first remarks on late pleistocene lacustrine deposit in the berceto area (northern apennines, italy). (it issn 0394-3356, 2004). during a geognostic survey performed by the servizio difesa del suolo of the emilia-romagna district administration in correspondence to the berceto village (northern apennines, parma province), a lacustrine sequence of about 25 metres was found in the borehole berceto spz2. this paper shows the preliminary results coming from the analysis of the berceto lacustrine deposit and suggests the morphological setting that may have contributed to the origin and development of the lake. the geological and geomorphological surveys highlight that the landslides are the prevalent processes affecting the berceto slope. the lacustrine sequence is a part of the filling of a trench that lies behind the dormant rotational rock slide involving the upper part of the slope. the entire core is 50 metres long. sedimentologic, pollen and microscopic analyses, the latters carried out on thin polished sections by both optical and scanning electron microscope (sem), together with radiocardon datings, allowed its division into 7 units and permitted us to obtain their features, ages and some inferences on their formation. from the top to the bottom of the core, a first unit (0-4.30 m) represents material reworked by the strong anthropic use of the place. below it, a level of peat (unit 2; 4.30-6.10 m), represents the ending of the lacustrine basin. it records a floristic phase characteristic of the middle-lower postglacial of the northern apennines. the unit 3 (6.10-9.20 m), together with the subsequent units 4 (9.20-17.00 m) and 5 (17.00-31.00 m), represent the real lacustrine deposit. the presence of laminated structures is the main feature of this sequence. both clastic graded millimetric laminae and couplets of dark and pale clayey ones are present. they are evident in unit 5 and begin vanishing proceeding towards the top of the sequence (unit 4), being almost completely destroyed in correspondence to unit 3. the units are affected by deformations of different types (penecontemporaneous and/or post-depositional) and extent, occurred either very close or far from the water-sediment interface. the lacustrine sequence developed during the upper pleistocene. below the lacustrine deposit, a breccia (unit 6; 31.00-48.00 m) is present. it represents a weathered cover derived from the rocks outcropping in the area, subsequently involved in mass wasting processes of the slope. it is probably related to the rotational rock slide affecting the western side of the berceto area, that may have represented the natural dam of the ancient berceto lake. the uppermost portion of the breccia contains a clayey matrix that may have waterproofed the bottom of the lake. the last unit 7 (48.00-50.00 m) may represent the substratum of the deposit and the berceto landslide. on the basis of the results of the whole study, it is possible to refer the formation of the lake starting from a geomorphologic context of the berceto slope very similar to the present one. in such a situation, the movements of the berceto landslide determined the presence of a trench, in which the lake progressively developed. the landslide movements started in the upper pleistocene and continued in the holocene up to the development of the present hollow of berceto. riassunto: bertoldi r. et al., note preliminari sul deposito lacustre tardo pleistocenico di berceto (provincia di parma). it issn 0394-3356, 2004). un sondaggio (berceto spz2) eseguito dal servizio di difesa del suolo della regione emilia romagna nel corso di una campagna geognostica condotta in corrispondenza del paese di berceto, posto alla sommità di un versante a cavallo tra le valli dei torrenti baganza e manubiola nel settore parmense dell’appennino settentrionale, ha individuato una sequenza lacustre dello spessore di circa 25 metri. lo scopo di questa nota è di illustrare i risultati preliminari derivanti dall’analisi del deposito lacustre di berceto e di ipotizzare, anche sulla base degli elementi morfologici dell’area, lo scenario che potrebbe aver portato alla formazione del lago. la sequenza rinvenuta costituisce parte del riempimento di quella cha si presenta come una blanda depressione, orientata circa nnessw, occupata dal paese di berceto. la depressione è l’espressione morfologica di una trincea determinatasi nell’evoluzione della frana rotazionale quiescente in roccia che interessa la porzione altimetricamente più elevata del versante che da berceto degrada, verso nw, fino al corso del torrente manubiola. gli elementi morfologici rilevati hanno permesso di determinare come l’intera area sia interessata, prevalentemente, da morfogenesi gravitativa, che si esprime attraverso la presenza di numerose frane quiescenti di tipo complesso, condizionate dai caratteri litologici e strutturali delle rocce affioranti. la carota recuperata nel sondaggio berceto spz2 misura una lunghezza totale di 50 metri. su di essa è stata condotta una dettagliata analisi, implementata da osservazioni sia al microscopio ottico sia al sem di sezioni sottili tagliate nelle parti della sequenza lacustre che hanno conservato le strutture più significative per l’interpretazione della genesi del deposito. unitamente a ciò è stata condotta un’analisi palinologica preliminare del deposito e sono state effettuate una serie di datazioni radiocarbonio su materiale organico prelevato a differenti livelli entro la carota stessa. complessivamente gli studi condotti hanno permesso di suddividere l’intera carota in 7 unità. dall’alto verso il basso è stata individuata una prima unità (0-4,30 m) costituita da una breccia siltoso-argillosa polimittica che è il risultato del rimaneggiamento dovuto all’attività antropica. a questa fà seguito l’unità 2 (4,30-6,10 m), uno strato di torba alla cui base è presente un sottile livello di sabbie ricco di resti vegetali. questa unità presenta un contenuto floristico tipico del postglaciale medio-inferiore dell’appennino settentrionale, mentre non è rappresentata la storia paleobotanica dell’inizio dell’olocene e quella dell’olocene medio-superiore. questa mancanza è forse giustificata dall’evidente rimaneggiamento dell’intero livello; infatti la torba si presenta in un cattivo stato di conservazione, con chiare indicazioni di ossidazione e frantumazione. con il sottostante intervallo costituito dall’unità 3 (6,10-9,20 m) compare la sequenza di chiara origine lacustre. si tratta di un deposito massivo generalmente siltoso e localmente costituito da sabbie molto fini di colore grigio chiaro, con intraclasti di colore da grigio palliil quaternario italian journal of quaternary sciences 17(2/1), 2004, 133-143 134 r. bertoldi et al. 1. introduction during a geognostic survey performed in correspondence to the berceto village (northern apennines, parma province) by the servizio difesa del suolo of the emilia-romagna district administration, a lacustrine sequence of about 25 metres was found in the borehole berceto spz2. it is part of the filling of an hollow placed in the higher part of the slope where the village lies. the discovery of this lacustrine sequence represents a rare and very interesting finding within this part of the emilia apennines, particularly for its location. indeed lacustrine deposits from different sites in the high part of the emilia apennines, were sampled and studied in detail, but they were, mainly, lacustrine and/or peat sequences deposited behind glacial deposits and landforms, i.e.: lateral and frontal moraine ridges (watson, 1996). detailed studies on pollen sequences and radiocarbon datings allowed the identification of the main characteristics of pollen records from across the area and to examine the chronology of similar changes in pollen stratigraphy, from the holocene to the late glacial, up to 12,000 yr b.p. (bertoldi, 1980; bertoldi et al., 1986; cruise, 1990; lowe & watson, 1993; montanari et al., 1994; watson, 1996). unlike these latter, the berceto deposit is in the middle portion of the apennines area, where aggressive geomorphological processes, due to gravity and running waters, acted during the holocene, prejudicing against the preservation of relict landforms and deposits. the paper shows the preliminary results coming from the analysis of the berceto lacustrine deposit and suggests the morphological setting that may have contributed to the origin and development of the lake. 2. geological setting 2.1 general framework the berceto area is situated a few kilometres north of the cisa pass (fig. 1) and is therefore close to an important transversal tectonic discontinuity (i.e. the taro system auctt.) separating the northwestern ligurian-emilian apennines segment from the southwestern tuscan-emilian segment (bernini et al., 1997). these two apennine sectors mainly differ in the degree of tectonic uplift that involved them. while the nw sector is almost completely overthrust by external ligurian sequences (marroni et al., 2002), the se secdo a grigio scuro. la sottostante unità 4 (9,20-17,00 m) è rappresentata da un deposito siltoso, di colore grigio-giallastro, con struttura caotica. si rinvengono livelletti costituiti da lamine chiare e scure spesso di aspetto evanescente, deformate in modo duttile e, localmente, sabbie fini contenenti resti vegetali. l’analisi dei pollini contenuti nelle due unità 3 e 4 ha permesso di ricostruire una sequenza di eventi con un certo grado di coerenza, attribuibili verosimilmente al tardiglaciale. il contenuto della porzione medio-inferiore del sub-intervallo palinologico definito dalle unità 3 e 4 rimanda ad un periodo con caratteristiche cilimatiche glaciali di tipo stadiale cui segue, nella parte alta, un periodo di tipo interstadiale. datazioni radiocarbonio effettuate su campioni prelevati a 6,20 e 11,65 metri, hanno restituito valori rispettivamente di 11.150±70 14c yr b.p. e 14.480±50 14c yr b.p. e collocano le unità in periodi con condizioni climatiche come quelle prospettate dall’analisi palinologica, in accordo con le suddivisioni climatostratigrafiche per il pleistocene superiore, proposte da ravazzi (2003). i caratteri delle unità 3 e 4 suggeriscono, per la loro deposizione, un contesto di ambiente lacustre caratterizzato da una certa dinamicità. in particolare è verosimile ritenere che la deposizione risenta degli effetti di fenomeni gravitativi che hanno coinvolto direttamente i depositi laminati deformandoli e della rimozione, dalle porzioni marginali verso il centro del lago, di materiale che viene risedimentato, in occasione di afflussi importanti dal bacino di alimentazione. la deformazione penecontemporanea dei depositi risulta più evidente nell’unità 3 rispetto all’unità 4. l’unità 5 (17,00-31,00 m) è composta da lamine gradate siltose clastiche con spessori di qualche millimetro, di colore da giallastro a grigio chiaro, e lamine argillose submillimetriche di colore grigio scuro contenenti sostanza organica, cui si associano, talvolta, lamine sottilissime biancastre. le lamine sono sempre ripiegate e interessate da superfici di taglio, con andamento da suborizzontale a ondulato, tali deformazioni risultano post-deposizionali e non si sono verosimilmente sviluppate all’interfaccia acqua-sedimento. le lamine argillose scure si presentano come bande millimetriche di colore bruno composte di argilla, in cui compare, in maniera diffusa, materiale siltoso. l’analisi palinologica preliminare, sebbene condotta su di un numero esiguo di spettri, e la data radiocarbonio di 29.620±290 14c yr b.p., restituita da un campione prelevato a 22,50 metri, hanno permesso di collocare la sedimentazione dell’unità 5 nel würm medio delle alpi (ravazzi, 2003). infatti in concomitanza con la glaciazione würmiana alpina, si verificò anche nell’appennino settentrionale un massimo di espansione dei ghiacciai, ben espresso nelle valli dei torrenti parma e cedra. nella limitrofa val baganza, con ogni probabilità, si instaurarono, invece, condizioni prevalentemente di tipo periglaciale. nell’unità 5 le lamine chiaro-scure sono l’espressione di fasi di deposizione in un ambiente lacustre tranquillo, determinato da una ridottissima dinamicità delle acque del lago. a queste si associano le lamine clastiche la cui deposizione è avvenuta o in occasione dei periodi di apertura del sistema lago agli influssi esterni, o in conseguenza di fenomeni di risedimentazione per scuotimento del fondo del lago in occasione dei movimenti della frana. le pieghe e le superfici di taglio che interessano l’unità 5, testimoniano il coinvolgimento dei depositi in deformazioni legate verosimilmente a fasi di movimento della frana in roccia di berceto. la successiva unità 6 (31,00-48,00 m) è costituita da una breccia a clasti centimetrici angolosi immersi in una matrice siltosa. nella parte sommitale dell’unità la matrice della breccia diviene via via più argillosa e potrebbe aver avuto il ruolo di materiale impermeabilizzante il fondo del lago, contribuendo all’impostazione di quest’ultimo. il deposito, fortemente ossidato, dovrebbe rappresentare una coltre derivante dall’alterazione dell’originario substrato costituito da arenarie di scabiazza (cfr. arenarie di ostia), largamente affioranti nell’area, successivamente coinvolta in fenomeni gravitativi da mettere, verosimilmente, in relazione con la frana in roccia che interessa la parte sommitale del versante di berceto. negli ultimi due metri il sondaggio (unità 7; 48,00-50,00 m) si è approfondito all’interno delle argille a palombini di monte rizzone, che dovrebbero rappresentare il substrato dell’intero deposito e del movimento franoso, e che in affioramento compaiono a sw dell’abitato di berceto. sulla base di quanto emerso dallo studio geomorfologico del versante e dall’analisi della carota berceto spz2 si può prospettare che il lago si sia formato a partire da una situazione morfologica del versante di berceto non molto diversa da quella attuale. in un tale contesto il progressivo collasso della frana in roccia avrebbe portato all’apertura della trincea nella quale si sarebbe impostato il lago. tale scenario prevede l’inizio dell’evoluzione della frana a partire almeno dal pleistocene superiore e la sua prosecuzione fino all’olocene e in quest’epoca la depressione si sarebbe progressivamente colmata fino a raggiungere l’attuale conformazione keywords: late quaternary landslide, laminated lacustrine deposit, baganza valley, northern apennines. parole chiave: frana tardo-quaternaria, deposito lacustre laminato, val baganza, appennino settentrionale. 135first remarks on late pleistocene ... fig. 1 geological map of the berceto area (for the cross-section bb’ see fig. 3). 136 tor is more exhumated and amply exposes the underlying subligurian units and the deeper foredeep units characterised by a ne-verging thrusting. the tectonic uplift of the tuscan-emilian segment, clearly visible in the structural feature of the macigno outcropping along the main apennine backbone, was formed in the pleistocene (argnani et al., 2003). the uplift of the backbone is accompanied by an extensional tectonic regime developing nw-se fault systems responsible for the grabens on the tyrrhenian side of the apennines (bernini & papani, 2002). corresponding to the cisa pass transversal lineament, the outcroppings of the tuscan and umbrian units are interrupted towards nw by a general nw axial plunging of the folding (bernini & vescovi, 2002) and by transtensive sw-ne faults, with sinistral strikeslip components (vescovi, 1988). 2.2 tectonic evolution of the berceto area the area of the village of berceto, close to the divide between the torrents manubiola and baganza, is obliquely crossed by a high-angle fault with left-handed transpressive kinematics, and a sw-ne direction binds a tectonically uplifted area to the nw (fig. 1). near berceto, it is thus possible to identify an sverging recumbent anticline, affecting the scabiazza sandstone, cut by a sub-horizontal thrust surface which formed during the ne-verging neogene thrusting. the recumbent anticline involving the scabiazza sandstone is indicated in the geological structural map in fig. 1 illustrating its axial trace separating the normal limb of the sardello-case san genesio area from the overturned limb on which the northern outskirts of the town of berceto are situated. the stratigraphically lowest lithofacies in the unit, rich in sandstone layers, outcrops in correspondence with the normal limb, while the outcrops of the overturned l imb, where the northwestern part of the village sits, are characterized by the overlying marly lithofacies. in the rest of the town, the formation is only visible in excavations and appears to belong to a normal limb uplifted by faulting. here the scabiazza sandstone, which is heavily fractured, presents limited thicknesses and stratigraphically follows the palombini shale of mt. rizzone (vescovi, 2002), which is well exposed in an excavation located slightly sw of the seminario (fig. 2) and also found in the borehole drilled in the village (fig. 1). it is therefore clear that the main portion of the village is located on a tectonically greatly uplifted normal limb and thus heavily eroded, phenomenon which obviously also involves the underlying mt. caio flysch. this uplifting developed ne-trending transtensive faulting and ssw-nne normal faults, characterized by low magnitude of offset; also present are nw-se trending normal faults, which are likely to fall within the framework of the extensional tectonic regime which is well developed in the apennine inner sector. this tectonic framework provides a boundary for an area where low thicknesses of scabiazza sandstone overly substantially shaly units (i.e.: palombini shales of mt. rizzone and shales of the ophiolitic complex). these features predisposed the gravitative movements towards nw, probably accompanied by downslope rotational slides during the quaternary morphogenesis evolution of the berceto area. 3. geomorphological setting the berceto village lies at 830 m a.s.l., in correspondence to the divide between the baganza and manubiola torrents, this latter being a tributary of the taro river, and is located in the middle apennines not far from the main glaciated terrains during the upper pleistocene (federici & tellini, 1983; gngfg, 1988). the berceto slope, which runs westwards, extends between the village itself and the manubiola fig. 2 se-dipping palombini shale of mt. rizzone formation. it was exposed some years ago in an excavation located near the seminario (see fig. 1). this rock, in which the slip surface of the dormant rotational rock slide of berceto developed, was found at the bottom of the berceto spz2. r. bertoldi et al. 137 fig. 3 sketch map of the main geomorphological features of the berceto area. legend of the cross-section bb’: 1) sliding surface of landslide, 2) landslide body; for the geologic symbols used in it see the legend of fig. 1. first remarks on late pleistocene ... 138 torrent, (represented in the tectonic sketch map of fig. 1). the geomorphologic survey highlights that the landslides are the prevalent processes on it. the most landslides, apart from some small active ones, are dormant and of complex type (fig. 3). they are rotational and/or roto-translational slides, with relatively deep surface of movement, and earth-flows, especially in the sw part of the slope. in the detachment area, corresponding to the divide between manubiola and baganza torrents, dormant rotational rockslides involving scabiazza sandstone and palombini shale of mt rizzone formations prevail (fig. 3). on these landslides lie the ancient portion and most of the new portion of berceto village. a mild hollow, with a long axis oriented approx. nne-ssw and with an extension of about 30x103 m2, takes up the area between the village and the divide eastwards. it represents the morphological expression of the trench behind the rotational slide. the borehole berceto spz2 was drilled in its centre (fig. 3) and a core of about 50 metres was extracted. on the right side of the manubiola valley, the lower portion of the slope presents very slow movements. in the last years they have been monitored by gps measurements carried out by the society of the cisa motorway. recently even researchers of the department of earth sciences of modena and reggio emilia university have monitored them by sar interferometry. these movements may be the result of a deep seated gravitational slope deformation (dsgsd) (ronchetti, 2002-2003) that involves part of the slope (fig. 3). some geomorphologic elements, i.e. deep torrential cuts, small trenches pulled apart from scarps and small landslides placed in correspondence with the edges of the breakdown area, are the morphological expression of the existence of this large landslide (fig. 3). 4. the core berceto spz2 4.1 description and analysis of the berceto spz2 core a detailed macroscopic analysis of the core was performed. it allowed the recognition of seven lithologic units (fig. 4). two metres of palombini shale of mt rizzone (bedrock) were found at the bottom of the borehole. a preliminary petrographic and mineralogical study of unit 5 was carried out on thin polished sections by both optical and scanning electron microscope (sem). mineral analyses were made using an electron microprobe jeol-6400 equipped with an energydispersive microanalytic system; operating conditions were an accelerating voltage of 15 kv and a probe current of 0 na. they were cut in correspondence with levels where the structures are very evident. the detailed description of the lithologic units is shown in fig. 4. unit 5 shows well-preserved laminae. some details of these sedimentary structures are presented in fig. 5. in fig. 5a a sequence of clastic and dark organic laminae is shown. the clastic laminae show a quartz rich basal portion and a gradation from coarse to fine, sometimes well visible as in (fig. 5a (1)). substantially, they appear as thin turbidites and are like graded beds (sturm, 1979). in the clastic laminae the sem analyses highlighted the presence of quartz, albite, na-ca plagioclase, calcite, dolomite, hornblende, biotite, chlorite, muscovite, sphene, fe-ti oxides. the matrix of the laminae is formed mainly by mixed layers of clay minerals (illite/smectite). the minerals present in the clastic laminae reflect the composition of the rocks outcropping in the area. in the middle part of the photograph two vanishing and discontinuous dark levels are among three clastic laminae. they represent the relicts of the clayey laminae eroded by the thin turbidites (fig. 5a (2)). the analyses of the clayey laminae show they are mainly formed by mixed layers of clay minerals (illite/smectite), with rare grains of quartz, calcite, chlorite, illite, dolomite, ilmenite and muscovite. the grains with elongated shape are arranged parallel to the layers itself. the same features are visible in fig. 5b too. the basal erosional boundary of a turbiditic layer (fig. 5b (1)) is worth noting. it is highlighted by the alignment of small vanishing bodies of dark clay and by the overlaying quartz rich portion of a turbidite lamina. in the upper part of the photograph there are two turbidite layers (fig. 5b (2)) that show very deformed basal boundaries. these features are well reproduced in fig. 5c that represents the prosecution towards right of the same laminae of the previous photograph. in fig. 5c (1) load casts are shown. they are common in the loaded surfaces and they arise from the sinking of silt into dark clay, leading to the upward injection of little clayey flame structures. in fig. 5c (2) the dark clayey lamina deformed by the overlaying clastic bed is evident. the deformation occurred during the turbidite sedimentation of the clastic lamina, which had a current flow from the right to the left of the photograph. where the turbidite sedimentation did not cause the deformation of the underlying clay lamina, the detailed features of the latter are visible. fig. 5d represents the close-up of the middle part of fig. 5b. the presence of couplets of dark and pale laminae (fig. 5d (1)) is clear in it. some of the pale laminae were also analysed, dolomite and mixed layers clay minerals (illite/smectite) were found. fig. 5e shows detail of deformed laminae in unit 5 (fig. 4). they are affected by folding and shear surfaces. the photograph shows the very ductile character of the deformation, connected to the plastic state of this deposit. 4.2 pollen analysis and radiocarbon datings the pollen analysis of the berceto spz2 core in the interval of depth 0-31 metres was performed. the core was sampled closely and a hundred samples were taken. up to now twenty samples were examined for the general recognition of the pollen contents of the sequence. they were chosen to represent the whole interval and prepared by employing the classic methodological approach of pollen enrichment. the procedures include washing with hcl, soaking in hf, luber technique, boiling in diluite koh followed by enrichment procedures, in particular gravitative separation r. bertoldi et al. 139 fig. 4 sedimentologic c h a r a c t e r i stics of seven units making up the berceto spz2 core and their meaning (on the right hand), radiocarbon d a t i n g s performed on organic matter ( in the middle) and characteristic features of the l a c u s t r i n e deposit (on the left hand) are presented. first remarks on late pleistocene ... using heavy fluids (zncl2 at d = 2,004) and finally sonication. on the basis of the preliminary results of the pollen analysis it was possible to delineate the first sketch of the floristic and vegetational evolution of the area and to divide the interval 0-31 metres into four palynological subintervals, only partly in agreement with the sedimentologic units. the first subinterval ranges between 0.00 and 4.40 metres. the microscopic analysis of two levels containing vegetal scraps proves the scarcity and bad state of preservation of the sporomorphs. this evidence confirms the reworking of this unit, already recognized from the sedimentological point of view. the second subinterval corresponds to unit 2 (fig. 4) and ranges between 4.40 and 6.10 metres. six levels, spaced 50 cm from each other, were considered altogether. the arboreal plants (ap) prevail over the non-arboreal plants (nap), the latter being only 20% of the pollen sum. within the ap abies clearly prevails, being represented by more than 40% of the total amount. quercus, sometimes accompanied by rather low values of tilia and ulmus, shows lower percentages than 20%, except for the spectrum where the oaks are dominant on the silver fir. pinus shows continuously decreasing percentages (from 20% to 8%) from the bottom to the top of the subinterval, whereas betula, corylus, alnus, populus and salix show very low values. fagus is present only in the uppermost spectrum. the sporomorphs appear to be badly preserved in every level, especially those of abies. they are dark brown, corroded, degraded and crumpled. the microscopic examination reveals that the remains of peat are represented by amorphous dark brown organic matter, almost completely oxidized. nevertheless, frequent remains of vessels of broad-leaved trees, scarce findings of fibre-tracheids of conifers and rare cellular aggregates of epidermis-type are present. the third subinterval ranges from 6.10 to 17.00 metres, enclosing sedimentologic units 3 and 4 (fig. 4). twelve samples regularly distributed along this part of the core were examined. in every spectrum the ap prevails, with pinus clearly dominant. the herbaceous flora (nap) is qualitatively and quantitatively rich. the main types such as artemisia, chenopodiaceae, gramineae, compositae, helianthemum, caryophyllaceae, etc., are always present and show positive and negative fluctuations. a significative difference is recognizable between the spectra corresponding to the uppermost metre of the subinterval and those of the part below. in the former comparatively plentiful pollen grains of betula, abies, quercus and corylus are present together with pinus. in the latter the arboreal flora is qualitatively poorer: only scarce findings of betula and picea are present, together with pinus. ephedra and juniperus are almost always present. the fourth subinterval, from 17.00 to 31.00, corresponds to sedimentologic unit 5 of fig. 4. up to now only four out of about fifty spectra have been analysed, nevertheless some remarks can be made. the pollen flora (ap + nap) seems qualitatively and quantitatively poorer compared to the previous subinterval. pinus becomes predominant and few other types of pollen from pioneer plants (ephedra, juniperus, hippophae) are represented. rare grains of betula and picea are present. organic matter was extracted from different levels of the core and then submitted to beta analytic inc. (miami, florida, u.s.a.) in order to perform radiocarbon datings. at the level of very fine sand, just below the boundary between units 2/3, a sample containing scraps of plants was extracted at 6.20 metres. it supplies a date of 11,150±70 14c yr b.p. corresponding to 13,390140 fig. 5 the microscopic photographs show the features and characters of the laminated deposits of the unit 5. they are the best preserved of the entire lacustrine sequence. r. bertoldi et al. 13,240/13,220-12,900 cal 14c yr b.p. (beta 178882). in unit 4 a sample was extracted at 11.65 metres. it contained scraps of plants and small wood fragments. it provides a date of 14,480±50 14c yr b.p., 17,70517,000 cal 14c yr b.p.(beta 181866). finally organic matter was extracted at 22.50 metres from a dark lamina in unit 5. it supplies a date of 29,620±290 14c yr b.p. (beta 181867). although the results of the pollen analyses are still preliminary in type, they show a sequence of floristicvegetational events, which permits the possibility of reconstructing the climatic evolution of the area, corresponding to an interval of the upper pleistoceneholocene period, even if with some gaps, especially in the upper part. indeed the first subinterval (corresponding to unit 1 of fig. 5) suffered a hard reworking which did not give any meaningful result from pollen analyses and the second one (corresponding to unit 2 of fig. 5) presents wide gaps. the latter records a floristic phase characteristic of the middle-lower postglacial vegetational development of the northern apennines (bertoldi, 1980; lowe & watson, 1993), as proved by the well-known prevalence of abies and the almost complete lack of fagus. furthermore, they seem to lack the onsets of the holocene and undoubtedly of the middle-upper holocene paleobotanical history. on the other hand, the bad state of preservation of the sporomorphs together with the remains of peat clearly oxidized and broken up mean that the peat level likely underwent one or more events of reworking. the results obtained from the pollen analysis of the third subinterval appear to be more organized. wellpreserved pollen grains permitted the reconstruction of a sequence of events. the pollens of the flora and vegetation of the higher part of the subinterval are characteristic of interstadial periods, likely of the lateglacial interstadials, whereas those of the lower part of stadial ones. this evidence is supported by the radiocarbon datings performed on the samples at 6.20 and 11.65 metres. indeed, the dating of the first sample is referable to the late glacial interstadial of the climatostratigraphic subdivisions proposed by ravazzi (2003), deriving from the improvement of the chronostratigraphy of the late glacial from orombelli & ravazzi (1996). the dating of the second sample refers to the “early late glacial” (ravazzi, 2003), corresponding to the oldest dryas, in which more than one glacial stadial are reported for the different sectors of the alps (maisch, 2000). at present, few remarks can be made on the fourth subinterval. the small number of the pollen spectra analysed does not permit us to characterize it completely from the floristic and vegetational point of view. nevertheless, the analyses performed highlighted a paleo-environment of glacial type, as the radiocarbon dating at 22.50 metres confirms. indeed, it is included in the middle-pleniglacial stadial-interstadial phase of the alps (ravazzi, 2003) when also in the northern apennines the glaciation took place, e.g. in the close parma valley the glaciers had the great development (federici & tellini, 1983). 4.3 remarks on the sequence of the core the borehole reached the palombini shale of mt rizzone outcropping close to berceto (fig. 1). it goes down two metres in this formation which represents the bedrock (fig. 4). above the bedrock, there is a breccia (unit 6 in fig. 4) that in our opinion represents a weathered cover derived from the scabiazza sandstone, and subsequently involved in mass wasting processes of the slope. this deposit is probably related to the rock block slides involving the western side of the berceto area (figg. 1 and 3), which may have represented the natural dam of the ancient berceto lake. the uppermost clayey breccia may have waterproofed the bottom of the lake. above the breccia, the lacustrine laminated sequence (unit 5 in fig. 4) begins. most of the laminae show clastic graded texture and represent small repeated turbidite events. they may record either the sediment influx from the catchment to the lake or the flows from the marginal parts of the bottom of the lake. the dark and pale laminae are probably produced by precipitation and flocculation of clay-rich material, during periods characterized by the lack of coarse clastic inputs. the above unit 4 (fig. 4) does not show a regular laminated structure but vanishing dark and pale laminae are still visible. these features testify to the existence of the previous sedimentary structure of the material in the same way as in unit 5. in the following unit 3 (fig. 4) the deformation is more pronounced, the original laminated structure is almost destroyed and the material is rather homogeneous. on the whole, the sequence of units 5, 4 and 3 shows an increased deformation from the bottom to the top. this may be related to a unique important dynamic event or a sequence of different ones. in any case, the deformation was registered by these units in different ways. the deepest unit 5 records the deformation forming folds and shear surfaces, whereas in the upper units (4 and 3), closer to the water-sediment interface, the laminae were almost completely destroyed. the overlaying unit 2 (fig. 4) represents the ending of the lacustrine basin, passing from a thin sandy level to peat. finally, unit 1 (fig. 4) records no stratigraphic features, because of its complete reworking. this situation was determined by the strong anthropic use of the place, especially in the 20th century. 5. final remarks the geological and geomorphologic surveys of the berceto area highlighted the presence of a dormant rotational rock slide involving the area of the village, responsible for the trench at the top of the slope. the analyses (sedimentologic, pollen and microscopic analyses) performed on the berceto spz2 core allow us to put forward some remarks on the meaning of the different parts of the deposit filling the trench. in our opinion, the peat (unit 2 in fig. 4) represents the last deposit filling the hollow. despite the bad state of preservation both of the peat and of the above unit 1, the pollen analysis of the former allows us to refer its starting at least to the lower-middle holocene (boreal-atlantic?). 141first remarks on late pleistocene ... the units 3, 4 and 5 (fig. 4) represent the real lacustrine deposit. the radiocarbon dating and pollen analyses of unit 3 reveal that it deposited during the lateglacial, probably during an interstadial period. in this latter, the lack of well-defined laminae, the massive appearance of the deposit and the presence of intraclasts suggest that the deposition was in a dynamic environment. the sedimentation may be linked either to the occurrence of landslides and/or mass wasting, directly involving laminated lacustrine deposits, or to the re-sedimentation of fine material in the central part of the lake. this latter occurrence could be linked to the re-mobilization of laminated deposits from the marginal parts of the lake, because of the impact from the renewed coarse sediment influx from the catchment to the lake. the great similarity of the sedimentologic features between units 3 and 4 may lead to the assumption that they were involved in the same processes. nevertheless, the possibility to recognize, in unit 4, even vanishing dark and pale laminae suggests a lower extent of the deformation. indeed in our opinion, in unit 4 both penecontemporaneous and post-depositional deformations are present. this latter occurred when the sediment was more coherent and far from the watersediment boundary. unit 5 represents the most interesting part of the lacustrine deposit. the small post-depositional folds and the shear surfaces, affecting the laminae, testify to the fact that the deposit was involved in both compressive and, likely, extensive deformations. in our opinion, these deformations may have occurred during the different phases of movement of the landslides of the berceto slope. the sedimentologic features, together with the radiocarbon dating (29,620±290 14c yr b.p.) and the pollen analyses, suggest that the deposition was concomitant with climatic conditions of a glacial type, when in the area studied, periglacial ones were likely established. the dark and pale laminae could be the result of quiet sedimentation, perhaps decantation, linked to a dynamic of the water reduced to the minimum. the situation responsible for the formation of clastic laminae presents itself again. they either represent events of sedimentation of very fine clastic material that formed when the lake-system opened, and the sediment influx from the catchment occurred, or re-sedimentation in the occurrence of landslides activity, when the movement caused the re-mobilization of the unconsolidated sediment of the bottom of the lake. the knowledge we currently have about the laminated lacustrine deposit does not allow us to put forward definite data concerning its meanings as regards the biological and geochemical response to factors leading to their formation. nevertheless, the evidence on the laminae allows us to make some remarks. the nature of the laminae, their composition and the relationships between them prove that they are clastic laminations (o’sullivan, 1983). the couplets of dark and pale laminae are structured like varve, but it is early to advance any inference about their real meaning as annual or seasonal layered deposits. this is clear if one considers that the formation of clastic varves is very sensitive to the sediment influx and mechanisms of transport within the lake. particularly it is regulated by the flush of the first peak discharge of the season, whose behaviour does not assure that couplets of laminae represent true varves but rather longer and shorter time intervals (anderson & dean, 1988). in addition, the possibility of re-sedimentation of sediment complicates the state further. in any case, even if the laminae could be considered varves they pertain to the non-glacial ones. unit 6 is the deepest recognized within the berceto spz2 core. as reported above, it is a breccia containing very weathered material from a fine facies of the scabiazza sandstone and it could represent either the filling of the berceto landslide trench or an older eluvial cover. the upper part of the unit becomes rich in very fine matrix that allowed its waterproofing and the birth of the lake. on the basis of this evidence and their meaning, we advance the hypothesis that the formation of the lake started from a geomorphologic context of the berceto slope very similar to, although obviously not exactly the same as, the present one. in such a situation, the pleistocene movements of the berceto landslide determined the presence of a trench, in which the lake progressively developed. the landslide movements continued up to the holocene and they drove to the development of the present hollow of berceto. essentially, the berceto lake may be related to the dynamic of this landslide. this latter started in correspondence of the middle period of the last glaciation of the northern apennines and continued to develop through the late glacial. analogous ancient landslide was already reported in the middle parma valley (carobbio landslide; 25,129±160 14c yr b.p., 17,330±110 14c yr b.p., tellini & chelli, 2003). the study of berceto spz2 core is still in progress especially for the part concerning the real lacustrine deposit (units 3, 4 and 5 in fig. 4). in our opinion, the detailed study of the sequence may provide useful proxy data to investigate the palaeoclimatic conditions of this part of the northern apennines. this information could also be important in the definition of the climatic factors, such as periods of increased rainfall, forcing the phases of activity of the berceto slope landslides, contributing to the study carried out on this topic in the last few years for the emilian apennines (bertolini & tellini, 2001; tellini & chelli, 2002; 2003). acknowledgements this study was supported with the grant of the research project “late quaternary climate change and slope instability in the northern apennines (italy)” (chief: prof. c. tellini, university of parma; national chief: prof. m. soldati, university of modena and reggio emilia), and the grant of the local research project fil 2004 “evoluzione geomorfologica tardoquaternaria: casi di studio nelle alpi marittime e nell’appennino settentrionale” (chief: dr. s. perego, university of parma). we are grateful to dr. a. montanini (department. of earth sciences, university of parma) for the optical and sem analyses of the thin sections and the useful suggestions upon the mineralogical compositions. many thanks to e. masini for drawing of figs 1 and 3. this paper is the synthesis of the work and reflections of all the authors, but each worked on a specific 142 r. bertoldi et al. part of the paper. p. vescovi took care of the geological setting of the area, while a. chelli and c. tellini dealt with the geomorphologic setting and the landslides of the berceto area. the description, analysis and interpretation of the berceto spz2 core is the result of the work performed by a. chelli, c. tellini and p. vescovi together. r. bertoldi and r. roma dealt with the pollen analyses and their paleoclimatic interpretation. the opinions of all the authors are synthesized in the final remarks. references anderson r.y. & dean w.e. 1988 lacustrine varve formation through time. palaeogeog. palaeoclim. palaeoecol., 62, 215-235. argnani a., barbacini g., bernini m., camurri f., ghielmi m., papani g., rizzini f., rogledi s. & torelli l. 2003 gravity tectonics driven by quaternary uplift in the northern apennines: insights from the la spezia reggio emilia geo-transect. quat. int., 101-102, 13-26. bernini m. & papani g. 2002 la distensione della fossa tettonica della lunigiana nord-occidentale (con carta geologica alla scala 1: 50.000). boll. soc. geol. it., 121, 313-341. bernini m. & vescovi p. 2002 carta strutturale della media val taro alla scala 1: 100.000. atti del terzo seminario sulla cartografia geologica, bologna 26-27 febbraio 2002, 58-63. bernini m., vescovi p. & zanzucchi g. 1997 schema strutturale dell'appennino nord-occidentale. acta naturalia de “l'ateneo parmense”, 33, 43-54. bertoldi r. 1980 le vicende vegetazionali e climatiche nella sequenza paleobotanica würmina e postwürmiana di lagdei (appennino settentrionale). acta naturalia de “l'ateneo parmense”, 18, 147175. bertoldi r., timossi a.m., borghi m.l. & magri d. 1986 studio di una piccola torbiera montana dell’appennino emiliano attraverso i microfossili vegetali. l’italia forestale e montana, 41 (4), 216230. bertolini g. & tellini c. 2001 new radiocarbon dating for landslide occurrences in the emilia apennines (northern italy). trans. japan. geom. un., 22 (4), c-23. cruise g.m. 1990 holocene peat initiation in the ligurian apennines, northern italy. rev. paleob. palyn., 63, 173-182. federici p.r. & tellini c. 1983 la geomorfologia dell’alta val parma (appennino settentrionale). riv. geogr. it., 90, 393-428. gruppo nazionale geografia fisica e geomorfologia (gngfg) – cnr 1988 i l paesaggio fisico dell’alto appennino emiliano. studio geomorfologico per l’individuazione di un’area da istituire a parco. a. carton & m. panizza (eds.), grafis edizioni, 182pp. lowe j.j. & watson c. 1993 – lateglacial and early holocene pollen stratigraphy of the northern apennines, italy. quat. sc. rev., 12, 727-738. marroni m., molli g., montanini a., ottria g., pandolfi l. & tribuzio r. 2002 the external ligurian units (northern apennine, italy): from rifting to convergence of a fossil ocean-continent transition zone. ofioliti, 27 (2), 119-131. maisch m. 2000 the longterm signal of climate change in the swiss alps: glacier retreat since the end of the little ice age and future ice decay scenarios. geogr. fis. dinam. quat., 23, 139-151. montanari c., guido m.a., boccaccio a. & rametta m. 1994 paleoecologia olocenica del monte gottero (parma) nel quadro della storia del popolamento vegetale dell’appennino ligure. il quaternario – italian journal of quaternary sciences, 7 (1), 373380. orombelli g. & ravazzi c. 1996 the late glacial and early holocene: chronology and paleoclimate. il quaternario – italian journal of quaternary sciences, 9 (2), 439-444. o’sullivan p.e. 1983 annually-laminated lake sediments and the study of quaternary environmental changes – a review. quat. sc. rev., 1, 245-313. ravazzi c. 2003 an overview of the quaternary continental stratigraphic units based on biological and climatic events in italy. il quaternario – italian journal of quaternary sciences, 16 (1bis), 11-18. ronchetti f. 2002-2003 la frana di berceto (val taro – appennino parmense). dipartimento di scienze della terra, università degli studi di modena e reggio emilia, unpublished thesis. sturm m. 1979 origin and composition of clastic varves. in: schlüchter c. (ed), morains and varves, balkema, rotterdam, 281-285. tellini c. & chelli a. 2002 antichi movimenti di frana dell’appennino parmense e relazioni con le condizioni paleo-climatiche del tardo quaternario. l’orsaro, 22 (2), 9-20. tellini c. & chelli a. 2003 ancient and recent landslide occurrences in the emilia apennines (northern apennines, italy). proc. workshop on “geomorphological sensitivity and system response”, camerino-modena apennines (italy), july 4th-9th, 2003, 105-114. vescovi p. 1986 l'assetto strutturale della val baganza tra berceto e cassio (pr). acta naturalia de “l'ateneo parmense”, 22, 85-111. vescovi p. 1988 la linea trasversale passo della cisaval parma-bassa val d'enza: 1. sistema trascorrente sinistro nella zona del passo della cisa (prov. di parma). acta naturalia de “l'ateneo parmense”, 24, 221-243. vescovi p. (coord.) 2002 foglio 216 " borgo val di taro" della nuova carta geologica d'ital ia 1:50.000. servizio geologico d'italia. watson c.s. 1996 the vegetational history of the northern apennines, italy: information from three new sequences and review of regional vegetational chiange. jour. biogeog., 23, 805-841. 143 ms. ricevuto il 25 maggio 2004 testo definitivo ricevuto il 28 settembre 2004 ms. received: may 25, 2004 final text received: september 28, 2004 first remarks on late pleistocene ... imp.rossi& studio macrosismico del terremoto dell’aquilano del 24 giugno 1958 antonio rossi1, andrea tertulliani1, maurizio vecchi1 1ingv istituto nazionale di geofisica e vulcanologia, roma (e-mail:a.rossi@ingv.it, tertulliani@ingv.it, vecchi@ingv.it) riassunto: a. rossi, a. tertulliani & m. vecchi, studio macrosismico del terremoto dell’aquilano del 24 giugno 1958. (it issn 03943356, 2005). questo lavoro presenta lo studio di revisione del terremoto che colpì la media valle dell’aterno il 24 giugno 1958 con magnitudo pari a 5.0. scopo della ricerca è quello di completare il quadro delle conoscenze su questo evento poco noto, ed inquadrarlo nel contesto della sismicità di area e in un possibile schema sismotettonico della valle dell’aterno. la revisione dei dati macrosismici ha contribuito a incrementare largamente il numero di località del piano quotato conosciuto dal catalogo parametrico dei terremoti italiani, portandolo da 14 a 223, ed a proporre nuovi parametri di sorgente del terremoto. l’intensità massima è lievemente diminuita rispetto a quanto noto finora, mentre risulta aumentato il numero delle località oltre la soglia del danno. abstract: a. rossi, a. tertulliani & m. vecchi, macroseismic study of the june 24, 1958 earthquake, l’aquila (central italy). (it issn 0394-3356, 2005). this paper deals with the macroseismic review of the june 24, 1958 event, that struck the middle aterno valley, near l’aquila, with m=5.0 and epicentral intensity of vii-viii mcs. the main goal of the study was to enlarge the knowledge about this event, comparing it to the historical seismicity in the area and to the seismotectonic context. research in public archives allowed us to retrieve unpublished documents useful in deepening the earthquake knowledge. following the revision the number of intensity points passes from 14, as in recent catalogues, to 223. the number of damaged localities increases from 12 to 19. the greatest contribution to the increasing of the knowledge of this earthquake comes from the re-appraisal of the seismic cards, hold in the ingv macroseismic archive. after the revision new source parameters have been computed according to gasperini and ferrari (1995) and gasperini et al. (1999): the epicentral intensity results vii mcs, and the me (macroseismic magnitude) remains fixed to 5.0 . parole chiave: terremoto, macrosismica, media valle dell’aterno, sismotettonica, sismicità storica. keywords: earthquake, macroseismics, middle aterno valley, seismotectonics, historical seismicity. il quaternario italian journal of quaternary sciences 18(2), 2005 101-112 1. introduzione il 24 giugno 1958 alle ore 06:07 gmt una forte scossa di terremoto interessò la media valle dell’aterno (appennino abruzzese) con una magnitudo pari a 5.0, calcolata all’epoca sulla registrazione della stazione di roma-ing (di filippo e peronaci, 1964). questo evento, che interessò una zona dove le conoscenze storiche sulla sismicità sono abbastanza incomplete, produsse danni in una limitata area a se della città de l’aquila e fu risentito fino a una distanza di oltre 90 km, a roma ed in vaste aree delle marche, umbria e lazio. l’interesse per questo terremoto risiede quindi nel fatto di costituire un elemento interpretativo importante per l’approfondimento delle problematiche sismiche di tutta la conca aquilana. infatti è l’unico evento di un certo rilievo nell’area negli ultimi 150 anni e presenta, come illustrato in seguito, chiare similitudini con il terremoto del 1461, massimo evento storico dell’area stessa (x grado). scopo del presente lavoro è la revisione macrosismica del terremoto del 24 giugno 1958, nel quadro della sismicità della media valle dell’aterno ed alla luce del notevole incremento dei punti di intensità apportato nel corso della ricerca, rispetto alla letteratura di riferimento. 2. inquadramento sismotettonico della media valle dell’aterno l’attuale regime tettonico dell’appennino abruzzese è principalmente caratterizzato da faglie normali con attività quaternaria, generalmente orientate nwse e ns. durante l’evoluzione della catena appenninica l’attività delle faglie normali principali ha portato, a partire dal pliocene, alla formazione di bacini intermontani, che ospitano sedimenti continentali plio-quaternari (fra gli altri: carraro & giardino, 1992; calamita & pizzi, 1994; galadini & galli, 2000; galadini et al., 2003). la sismicità di questo settore di catena è frequente ed elevata in energia, come ci documentano i grandi terremoti avvenuti nel corso della storia. possiamo ricordare i terremoti del 1349, 1703, 1706 e 1915 tutti eventi, secondo il gruppo di lavoro cpti, 2004 (d’ora in avanti cpti, 2004), con ix ≥ 10 (fig. 1). a questa sismicità possono essere associate diverse strutture sismogenetiche attive, come evidenziato da numerosi lavori pubblicati recentemente (vedi tra gli altri: giraudi & frezzotti, 1995; pantosti et al. 1996; cello et al., 1997; cello et al., 1998; galadini & galli, 2000; d’addezio et al., 2001) (fig. 1). focalizzando l’attenzione sull’area aquilana dobbiamo citare il fatto che diversi autori mettono in relazione il forte terremoto del 2 feb102 a. rossi, a. tertulliani & m. vecchi braio 1703 (x mcs) con le strutture del sistema di faglie dell’alta valle dell’aterno; moro et al., (2002) associano questo evento alla faglia di m.te marine, che borda il segmento settentrionale dell’alta valle dell’aterno, mentre cello et al., (1998) propendono per un settore un po’ più meridionale dello stesso sistema di faglie. nessun terremoto può essere ancora associato alle faglie che bordano il sovrascorrimento del gran sasso, nonostante siano state recentemente studiate anche con analisi paleosismologiche (fra gli altri giraudi & frezzotti, 1995; galadini et al., 2003). in particolare galadini et al. (2003) hanno evidenziato un potenziale alto livello di hazard relativo alla faglia di campo imperatore, considerata “silente” in quanto non associabile storicamente ad alcun evento sismico. la media valle dell’aterno, oggetto del presente lavoro, è caratterizzata da sistemi en-echelon di faglie normali con direzione circa appenninica che hanno generato una serie di depressioni disposte a nwse dove si riconoscono tracce di attività tardo-pleistocenica (bertini & bosi, 1993) sviluppatesi in più fasi deformative a carattere “pulsante”. il sistema di faglie della media valle dell’aterno (calamita et al., 2000) ad attività quaternaria viene definito con una lunghezza dell’ordine dei 23 km. una ipotesi di collegamento tra le strutture dell’area e i terremoti era stata fatta da di filippo & peronaci (1964) i quali sottolineavano l’esistenza di un “campo fagliato”, dovuto al recente sollevamento degli altopiani aquilani, responsabile della sismicità locale. se analizziamo la sismicità storica di quest’area, notiamo che risulta essere meno energetica che nelle aree circostanti, come l’alta valle dell’aterno, la maiella e il fucino, con l’unica eccezione del forte terremoto aquilano del 1461 (x mcs), (baratta, 1901; cpti, 2004). il resto della sismicità, come citata nel cpti (2004), sembra dovuta a terremoti minori, i più significativi dei quali avvenuti soprattutto nel xvii secolo, la cui ubicazione resta tuttavia abbastanza incerta causa la scarsità di informazioni. questi eventi, 1762, 1786, 1791, 1889 citati in letteratura come terremoti aquilani, probabilmente anche per il ruolo di accentramento culturale di l’aquila, restano infatti misconosciuti e scarsamente documentati, come descritto nel paragrafo successivo. il carattere di una sismicità più moderata rispetto ai settori di catena circostanti, è altresì confermato dall’analisi della sismicità recente per quel settore di appennino centrale, mostrata in figura 1 per il periodo 1983-2003 (m>3.5), che appare piuttosto contenuta, sia in frequenza che in energia, e sembra quasi ignorare la media valle dell’aterno. 3. descrizione dei terremoti storici della media valle dell’aterno fra i terremoti conosciuti nei cataloghi e nei repertori sismici (vedi ad es. baratta, 1901; postpichl, 1985; boschi et al., 2000) si annovera come evento più fig. 1 inquadramento generale dell’area studiata. in figura sono mostrati i terremoti storici, come riportati nel catalogo parametrico dei terremoti italiani (cpti, 1999); lo schema semplificato delle strutture tettoniche, limitato al settore centrale dell’appennino abruzzese; la sismicità recente, 1983-2003 e l’epicentro del terremoto del 1958. nel riquadro è evidenziata la valle dell’aterno. general sketch of the study area. historical seismicity is reported as quoted in cpti (cpti, 1999). a simplified tectonic framework is shown, together with recent seismicity and 1958 epicentre. aterno valley is evidenced in the big square. antico nell’aquilano il terremoto del 1315, la cui definizione, sia come localizzazione che come effettiva consistenza è tutt’altro che chiarita. secondo cpti (2004) l’epicentro dell’evento è localizzato nella zona del sulmonese a circa 50 km a se di l’aquila. questa localizzazione non è condivisa dagli scriventi, in quanto le informazioni che supportano la revisione (boschi et al., 1997), derivano da una sola fonte peraltro vaga. a nostro avviso, considerando tutte le informazioni disponibili per questo evento (contenute principalmente in: postpischl 1985; boschi et al., 1997; boschi et al., 2000), il terremoto del 1315 trova una sua più giustificata localizzazione nell’aquilano, con una intensità epicentrale dell’ viii grado mcs. più consistenti sono le notizie riferite al terremoto del 26 novembre 1461 che è il più forte terremoto della zona in studio (x mcs). questo evento, composto da due scosse principali nella stessa giornata, sembrerebbe localizzabile nella media valle dell’aterno (fig. 2). le fonti primarie sono cronache coeve, ritrascritte dall’antinori nel xviii secolo (antinori, sec. xviii; casti, 1887). tali cronache narrano con grande dettaglio i danneggiamenti subiti dalla città de l’aquila, facendo però pochi cenni ai paesi dei dintorni. il piano quotato mostrato in cpti (2004) risulta essere limitato a 10 località, di cui 5 con i0 ≥ ix. queste località sono la città di l’aquila, di cui si conoscono le descrizioni dei danni ed una stima delle vittime, e alcuni paesi siti a se de l’aquila lungo la media valle del fiume aterno (fig. 2), onna, poggio picenze, castelnuovo e sant’eusanio forconese. dalle fonti coeve note sembra emergere che quest’ultime località subirono danni molto gravi. nel corso della ricerca è emersa inoltre una storia locale (giannangeli, 1974), ignota ai repertori tradizionali, che rifacendosi al la corografia degli abruzzi dell’antinori, permette di aggiungere la località di bariscianello, antico sobborgo di barisciano, nel piano quotato con una intensità pari al ix grado mcs. non si hanno notizie di danni da altre località nei dintorni, all’infuori di rocca calascio: una informazione consolidata nella tradizione locale attribuirebbe ad antonio piccolomini, verso il 1480, la ricostruzione di parte del paese e della rocca distrutti dal terremoto del 1461. non avendo trovato conferma di questa notizia nelle fonti consultate, abbiamo assegnato una intensità incerta a rocca calascio (fig. 2). ai due eventi principali del 26 novembre seguì una sequenza caratterizzata da molte scosse che durò circa due mesi, con forti repliche come quelle del 4 e del 17 dicembre e del 4 gennaio 1462, che aggravarono sensibilmente il quadro di danneggiamento. studi sismologici specifici su questo terremoto non esistono; esso viene tuttavia considerato nei repertori sismici e nei più moderni cataloghi (vedi ad es: baratta, 1901; boschi et al., 1995), che però non ne hanno di fatto mai ampliato lo stato delle conoscenze che restano ferme a quanto scritto da baratta (1901). e’ questo un caso abbastanza emblematico, nel panorama dei cataloghi sismici italiani, dove alcuni forti terremoti sono stati registrati soltanto da una o pochissime fonti, dalle quali derivano in seguito tutte le altre fonti, peraltro poco significative dal punto di vista dell’apporto alle conoscenze. i motivi di ciò, ben illustrati da castelli e camassi (2000), sono senz’altro legati al periodo storico e alla localizzazione dell’evento. il terremoto cade infatti in un’area molto lontana dal 103studio macrosismico del terremoto ... centro amministrativo del regno di napoli (napoli per l’appunto), e vicino all’unico centro subalterno (l’aquila), che avrà catalizzato l’interesse per il terremoto, portando a oscurare i fatti avvenuti nelle contrade più isolate, e lontane da un centro amministrativo rilevante. queste considerazioni, unitamente allo stato delle conoscenze, ci portano ad affermare che il terremoto del 1461 potrebbe aver causato un danneggiamento sicuramente più esteso di quello ad oggi conosciuto, limitato alla media valle dell’aterno. altro terremoto dell’area (cpti, 2004) con una intensità rilevante è quello del 6 ottobre 1762 (vedi fig. 2), ix-x a castelnuovo, ix a poggio picenze e vii a l’aquila. il terremoto pur essendo documentato da materiali di archivio (boschi et al., 1995), mostra un piano quotato molto scarno, composto da sole 6 locafig. 2 piani quotati dei terremoti del 1461 (a) e del 1762 (b) aggiornati dopo il presente lavoro. per quanto riguarda il terremoto del 1461 il piano quotato è arricchito di due località non presenti nel cpti, barisciano e calascio, quest’ultima con intensità dubbia. updated intensity maps of the 1461 (a) and 1762 (b) earthquakes. in the map of 1461 two new localities (barisciano and calascio), are present, in respect with cpti (cpti, 1999). however calascio is indicated very doubtful. 104 lità. nel corso della presente ricerca è emersa una ulteriore fonte di archivio1 che riporta notizia di gravi danni nel paese di barisciano e sue frazioni permettendoci di modificare l’intensità di barisciano nel piano quotato del cfti (boschi et al., 1995), passando da felt a viii grado. altri eventi sono segnalati nell’aquilano alla fine del 1700, precisamente 1786 e 1791, le cui fonti uniche sono alcune gazzette del tempo che descrivono danni nella città dell’aquila (gu, 1786; gf, 1786; gb, 1786; gu, 1791). in tabella 1 sintetizziamo i terremoti di probabile origine locale con intensità maggiore o uguale al vii grado. 4. stato delle conoscenze sul terremoto del 24 giugno 1958 secondo il catalogo parametrico dei terremoti italiani (cpti, 2004) l’intensità epicentrale (io) dell’evento è del vii grado mcs con una magnitudo (maw) pari a 5.2. cpti indica come elaborato di riferimento il database di osservazioni macrosismiche (dom4.1) di terremoti di area italiana al di sopra della soglia del danno (monachesi & stucchi, 1997) collegato al catalogo parametrico di terremoti di area italiana al di sopra della soglia del danno (camassi & stucchi, 1997). il database dom4.1 riporta un elenco di 14 località di risentimento con la relativa intensità espressa in gradi della scala mcs, con una imax di vii-viii grado. l'unico studio specifico pubblicato su questo terremoto è quello di di filippo & peronaci (1964) che riporta i valori di intensità per 14 località e solo per 4 di queste le descrizioni degli effetti. nell’articolo tuttavia viene riportata una carta delle isosisme relativa all’intero campo macrosismico con 135 punti, basata evidentemente su informazioni relative al risentimento in molte località non citate nel testo, ma in possesso degli autori, come ad esempio le cartoline sismiche (di filippo & peronaci, 1964). purtroppo aver pubblicato la sola mappa senza il riferimento del piano quotato non rende giustizia allo scrupoloso lavoro di di filippo & peronaci (1964), e soprattutto non è di molto aiuto agli studi successivi. nella tabella 2 sono sintetizzati i parametri del terremoto come riportati dalle principali fonti esistenti in letteratura. da quanto illustrato risulta che lo stato delle conoscenze sugli effetti del terremoto presenti nei cataloghi è basato su informazioni disponibile per 14 località, non essendo stato possibile per gli autori successivi utilizzare tutti i dati usati da di filippo & peronaci (1964) per la loro interpretazione. tale numero di località appare decisamente modesto per poter valutare correttamente sia l'area dei massimi effetti, sia la distri1 archivio stato aquila, affari speciali, ii serie, barisciano, busta iii bis, in giannangeli 1974. ”.. nel 1762 (*) alle ore 10 del 6 ottobre una violentissima scossa di terremoto distrugge quasi un terzo del paese. non conosciamo il numero delle vittime. la casa di 9 stanze adiacente alla chiesa di collerotondo è rovinata quasi completamente, danneggiata la chiesa di valleverde. si provvede a ripristinare il campanile. secondo una relazione di giannandrea giardini i danni sopportati dal paese ammontano a 39.339 ducati. l'università di barisciano invia una supplica al re per l'esenzione temporanea dei tributi sottoscritta da antonio salomone, giacchino giannangeli e francesco saverio de angelis notaio. ...”. anno me gi ho mi area epicentrale ix mm me 1315 12 03 09 30 italia centrale 100 6.0 1461 11 26 21 30 aquilano 100 6.6 6.1 1762 10 06 12 10 poggio picenze 95 6.0 5.4 1786 07 31 l`aquila 70 4.8 4.8 1791 01 l`aquila 75 5.1 1958 06 24 06 07 aquilano 75 4.8 5.0 tab. 1 eventi con probabile origine nella media valle dell’aterno come citati nel catalogo parametrico dei terremoti italiani (cpti, 2004). list of events with probable location in the middle aterno valley. the quotation of events is from the parametric catalogue of italian earthquakes (cpti, 2004). a b c d e f to (gmt) = 06:07 06:07:03,15 06:07:04 06:07 06:07 coord. epicent. = = 42.349 13.440 42.350 – 13.433 42.333 – 13.467 42.34013.477 io (mcs) = vii = = vii vii imax (mcs) vii = vii-viii viii vii-viii vii-viii h (km) = = 10 10 = = magnitudo = = m = 4.96 ml = 5.0 ms = 4.8 ms = 4.8 località di risentimento 2 2 14 * = 14 14 eventi periodo sismico 6 6 = = = = tab. 2 parametri del terremoto del 24 giugno 1958, ore 06.07, come riportati nei principali cataloghi e nelle altre fonti conosciute. a) ing, 1958; b) marcelli & pannocchia, 1963; c) di filippo & peronaci, 1964; d) postpischl, 1985; e) monachesi & stucchi, 1997; f) cpti, 2004. * il numero 14 si riferisce solo alle descrizioni esplicitamente riportate da di filippo e peronaci nel lavoro, e non tiene conto delle località riportate nella mappa. synthesis of the epicentral parameters related to the 1958 earthquake, as quoted in the current seismic catalogues and other known sources. a) ing, 1958; b) marcelli & pannocchia, 1963; c) di filippo & peronaci, 1964; d) postpischl, 1985; e) monachesi & stucchi, 1997; f) cpti, 2004. number 14 is only referred to the descriptions quoted by di filippo and peronaci (1964) in their work, and not to the points in the map. a. rossi, a. tertulliani & m. vecchi 105 buzione dell'intensità sul territorio. appare infine quantomeno singolare che nei lavori precedenti, tranne in di filippo & peronaci (1964) che però non esplicitano i dati, non vi sia traccia della consultazione delle cartoline sismiche, che venivano spedite da corrispondenti accreditati, all’indomani di un terremoto, all’ufficio centrale di meteorologia ed ecologia agraria (ucmea, 1958). queste rappresentavano infatti l’unica procedura di raccolta sistematica di dati macrosismici usata in quel periodo. 5. ricerca dei dati e assegnazione delle intensità uno degli scopi principali di questo lavoro è quello di allargare il più possibile la base dei dati di riferimento. le indagini, finalizzate allo studio macrosismico di questo evento, si sono svolte inizialmente attraverso la consultazione dei cataloghi e bollettini sismici, e della letteratura scientifica, in verità piuttosto scarsa; in secondo luogo attraverso la ricerca e la raccolta delle informazioni in archivi e biblioteche. essendo infatti il terremoto avvenuto in epoca abbastanza recente, abbiamo esaminato in primo luogo gli atti amministrativi, reperibili negli archivi pubblici, che si riferiscono alla corrispondenza tra le autorità del luogo e il governo. inoltre sono stati analizzati i quotidiani dell’epoca, specie per quanto riguarda le cronache locali, come fonti di notizie inedite per completare il quadro della conoscenza degli effetti. di seguito viene illustrato il contributo di ciascuna categoria di fonti consultate oltre a quello della letteratura scientifica conosciuta precedentemente descritto. quotidiani sono stati consultati i giornali quotidiani nazionali più importanti e le testate locali (vedi elenco in bibliografia) che riportano informazioni relative a un modesto numero di località di risentimento (22), di cui soltanto 8 non riportate da altre fonti; inoltre, la descrizione degli effetti è limitata a 7 località fra tutte quelle riportate, mentre per le altre 15 la notazione è di un generico risentimento da notare che il contributo dei quotidiani è relativo in gran parte a località distanti dall’area epicentrale. documentazione d’archivio la consultazione dei materiali conservati negli archivi pubblici è stata focalizzata alla provincia dell’aquila, in quanto l’area maggiormente interessata dall’evento è circoscritta alle vicinanze del capoluogo abruzzese. archivio di stato de l’aquila, fondo “gabinetto prefettura”. sono stati consultati 29 documenti consistenti nella corrispondenza tra le diverse autorità (sindaci, prefetto, carabinieri, ecc.), e sono emerse informazioni sul risentimento in 25 località della provincia de l’aquila di cui 8 non sono riportate da altre fonti. archivio dell’ istituto nazionale di geofisica e vulcanologia (ingv) presso l’archivio dell’ingv è stata esaminata la collezione delle cartoline sismiche pervenute all’ufficio centrale di meteorologia ed ecologia agraria, ed ora conservate presso l’ingv. la consultazione ha consentito di incrementare in modo decisivo il numero delle località di risentimento conosciute e di migliorare nettamente la qualità dei dati attraverso più dettagliate descrizioni dei risentimenti in moltissime località. e’ stato così possibile avere notizie sul risentimento a grandi distanze dall’epicentro. il numero finale di località individuate tramite le cartoline è di 204. inoltre è stata reperita la “relazione sulla sismicità delle zone inscritte nell’elenco…” di de panfilis (1959), inedita, scritta per la commissione ministeriale per le norme edilizie dell’epoca. nel documento viene assegnata l’intensità a 18 località interessate dal terremoto del 1958 con una breve descrizione degli effetti. al termine della ricerca il numero di località rappresentate nel piano quotato è decisamente cresciuto, passando da 14 a 223, comprese anche 88 località con risentimento negativo, utili per circoscrivere l’area di risentimento. dalla tabella 3 si nota come il contributo decisivo venga dalla rilettura delle cartoline sismiche ed in misura minore da fonti di stampa e amministrative. fonte numero località cartoline sismiche 204 archivio di stato l’aquila 26 giornali 23 de panfilis (1959) 18 di filippo & peronaci, 1964 14 monachesi & stucchi, 1997 14 tab. 3 sono riportati i contributi dei diversi tipi di fonte utilizzati per l’individuazione delle località di risentimento. numero di località è in relazione al tipo di fonte consultata. per 35 località vi sono informazioni riportate in più fonti. number of localities quoted in each kind of source that has been retrieved. 35 localities are quoted in more than one source. dalla nostra ricerca emergono anche utili informazioni che consentono di prolungare il periodo sismico fino al 2 luglio 1958. sono state infatti individuate altre scosse associate alla piccola sequenza sismica che hanno contribuito ad accrescere il numero totale delle scosse, portandolo da 6 (ing, 1958; marcelli & pannocchia, 1963) a 14. 5.1 assegnazione dell’intensità l’intensità macrosismica è stata stimata utilizzando la scala mercalli-cancani-sieberg (mcs) (sieberg, 1930). tutte le informazioni provenienti dalle diverse fonti per ogni località hanno contribuito alla valutazione. in alcuni casi sulla cartolina sismica era riportata solo l’intensità, per cui, in mancanza di altre informazioni, abbiamo mantenuto il valore indicato. sul retro della cartolina sismica era infatti stampata una sintesi della scala mercalli a 10 gradi (mercalli, 1902), in modo che il corrispondente potesse confrontare direttamente le proprie osservazioni con la scala macrosismica e assestudio macrosismico del terremoto ... 106 gnare egli stesso il grado di intensità per la località in questione. la scala mercalli a 10 gradi e la scala mcs a 12 corrispondono abbastanza univocamente almeno fino al vii grado, evitando così di apportare conversioni alla valutazione. al termine dell’analisi delle fonti è stato possibile assegnare un valore di intensità a tutte le 223 località individuate (appendice 1), migliorando decisamente il quadro delle conoscenze sul terremoto. in particolare si è potuto ricostruire il piano quotato completo, dalle intensità più alte fino a risentimenti negativi, con i quali si può chiaramente definire l’area di risentimento generale dell’evento (vedi tabella 4 e figura 3). le località con danneggiamento passano da 12 a 19. il quadro del danneggiamento più grave è risultato limitato ad alcuni paesi, siti nella valle dell’aterno a se di l’aquila. l’intensità massima del vii grado mcs è stata assegnata alle località di onna, bazzano e s. demetrio ne’ vestini, dove si verificarono alcuni crolli parziali, qualche crollo totale e un danneggiamento lieve ma diffuso. più leggero il danno riscontrato in una quindicina di altri centri, con piccole lesioni più o meno diffuse e occasionalmente crolli parziali, tale da far stimare intensità del v-vi e vi grado. fra queste località anche la città dell’aquila dove sono documentate lesioni e qualche caduta di cornicione. 6. conclusioni nel corso degli studi sulla sismicità della zona dell’aquila, e in particolare della media valle dell’aterno, è stata intrapresa una ricerca per approfontab. 4 in tabella sono elencate le classi d’intensità con il relativo numero di località interessate. mettendo a confronto il presente lavoro con quanto riportato in letteratura risulta evidente l’incremento del livello di conoscenza sugli effetti del terremoto. (di-pe 1964 sta per di filippo & peronaci, 1964; mo-st 1997 sta per monachesi & stucchi, 1997). number of localities vs intensities classes after the revision in the present work. the improvement in the number of intensity points is very significant, if compared with that one of the former sources. (di-pe 1964 is for di filippo & peronaci, 1964; mo-st 1997 is for monachesi & stucchi, 1997). di-pe 1964 mo-st 1997 presente lavoro intensità mcs n. località n. località n. località vii-viii 2 2 vii 6 5 3 vi-vii 1 vi 4 5 8 v-vi 7 v 1 12 iv-v 12 iv 30 iii-iv 2 11 iii 40 ii-iii ii 11 nf 88 totale 14 14 223 fig. 3 campo macrosismico generale del terremoto del 25 giugno 1958. intensity map of the june 24, 1958 earthquake. a. rossi, a. tertulliani & m. vecchi 2000). tuttavia non possiamo trascurare del tutto il fatto che la particolare morfologia della zona, costituita da bacini alluvionali orientati nwse, abbia avuto un ruolo guida nella distribuzione del danneggiamento. una considerazione importante riguarda le aree del danneggiamento dei terremoti del 1461 e 1762 (figg. 3 e 4) che, seppur non ben definite, sembrano ricadere completamente nell’area di massima intensità del 1958. non è da escludere quindi una connessione tra le faglie riconosciute attive nell’area, alle quali non è stato finora associato nessun evento per mancanza di elementi osservabili sul terreno, e gli eventi qui discussi. ringraziamenti ringraziamo v. castelli, per le notizie storiche sui terremoti del 1786 e 1791; ringraziamo inoltre fabrizio galadini per le utili discussioni sui temi affrontati nell’articolo e diego molin i cui preziosi suggerimenti hanno contribuito al miglioramento del lavoro. 107 dire le conoscenze sul terremoto del 24 giugno 1958, il più recente tra i terremoti significativi della zona. i terremoti antichi con probabile epicentro simile a quello in studio sono stati quelli del 1461 e del 1762, il primo dei quali particolarmente dannoso (x grado) per i paesi della media valle dell’aterno. tuttavia la scarsità di notizie su questi eventi non permette di vincolarne con precisione localizzazione e dimensione, e per questo il terremoto del 1958 diviene un buon elemento di paragone per tutta la sismicità della media valle dell’aterno. durante la ricerca di nuove fonti, tuttavia, è stato possibile reperire notizie finora non note sui danni avvenuti nella località di barisciano in occasione di entrambi i terremoti, il che ci ha permesso di assegnare alla suddetta località l’intensità del ix grado per il 1461 e viii per il 1762 (fig. 2), modificando i piani quotati finora noti. la ricerca oggetto del presente lavoro ha portato a un grande incremento della conoscenza degli effetti del terremoto del 1958 rispetto a quanto presente nei cataloghi più recenti; il numero delle località del piano quotato aumenta infatti a 223 (vedere appendice 1). dalla figura 3 è possibile notare come l’evento abbia interessato una vasta regione dell’italia centrale, con l’area del danneggiamento limitata ad alcune località in provincia dell’aquila. l’intensità massima, rispetto al cpti, viene leggermente abbassata, e portata da vii-viii a vii. grazie al grande incremento di dati macrosismici e alla loro rivalutazione è stato possibile stimare nuovamente i parametri di sorgente relativi all’evento, utilizzando le procedure standard del cfti e cpti (gasperini & ferrari, 1995; gasperini et al., 1999) per i terremoti storici. i nuovi parametri, localizzazione, magnitudo e azimuth della sorgente sono riportati in tabella 5. la distribuzione delle massime intensità (fig. 4) ed anche la direzione dell’azimuth della ipotetica sorgente del terremoto ben si accorda con il quadro sismotettonico generale ed anche con quanto conosciuto delle locali strutture attive (bertini & bosi, 1993; calamita et al., 2000; galadini & galli, fig. 4 distribuzione delle intensità relativamente all’area epicentrale. con la stella è indicato l’epicentro proposto in questo lavoro. intensity map of the epicentral area and main tectonic structures of the area. the star indicates the epicentre. data lat lon me ntot naz azimuth rayleigh kuiper 06/24/1958 42.32 13.50 5.0 223 11 119± 23 <0.01 <0.01 tab. 5 nuovi parametri proposti per il terremoto del 24 giugno 1958. con me è indicata la magnitudo equivalente, ntot è il numero totale di dati macrosismici disponibili, naz è il numero di dati usati per il calcolo dell’azimuth di faglia. raylegh e kuiper rappresentano il livello di significatività degli omonimi tests. per i dettagli vedere gasperini & ferrari, (1995) e gasperini et al., (1999). new source parametres of the june 24, 1958 earthquake as proposed in the present work. me is the “equivalent magnitude”, that is assumed to represent the moment magnitude, ntot is the total number of macroseismic data, naz the number of data used for computing the source azimuth. last two columns show the significance levels of the raylegh and kuiper tests. for details see gasperini e ferrari, (1995) and gasperini et al., (1999). studio macrosismico del terremoto ... bibliografia antinori a. l. (sec. xviii) annali degli abruzzi, vol. xv manoscritto. baratta m. (1901) i terremoti d’italia, ristampa anastatica a. forni editore, bologna. bertini t. & bosi c. (1993) la tettonica quaternaria della conca di fossa (l’aquila), il quaternario, 6, 293-314. boschi e., ferrari g., gasperini p. guidoboni e., smriglio g., valensise g., (1995) catalogo dei forti terremoti in italia dal 461 a.c. al 1980, ingsga, pp. 973, ozzano emilia. boschi e., guidoboni e., ferrari g., valensise g., gasperini p. (1997) catalogo dei forti terremoti in italia dal 461 a.c. al 1980, ingsga, pp. 643, ozzano emilia. boschi e., guidoboni e., ferrari g., mariotti d., valensise g. and gasperini p. (eds.) (2000) catalogue of strong italian earthquakes from 461 b.c. to 1997. ann. geofis., 43, 609-868. calamita, f. & pizzi, a. (1994) recent and active extensional tectonics in the southern umbromarchean apennines (central italy), mem. soc. geol. it., 48, 541–548. calamita f., pizzi a., scisciani v., de girolamo c., coltorti m., pieruccini m., turco e. (2000) caratterizzazione delle faglie quaternarie nella dorsale appenninica umbro-marchigiano-abruzzese, in galadini f., meletti c., rebez a. (a cura di), le ricerche del gndt nel campo della pericolosità sismica (1996-1999), cnr-gruppo nazionale per la difesa dei terremoti, roma, 157-169. camassi r. & stucchi m. (a cura di) (1997) nt4.1 un catalogo parametrico di terremoti di area italiana al di sopra della soglia del danno. cnr-gndt. http://emidius.mi.ingv.it/nt/ carraro f. & giardino m. (1992) geological evidence of recent fault evolution. examples from campo imperatore (l’aquila-central apennines) , i l quaternario 5, 181–200. castelli v. & camassi r. (2000) per un’analisi di completezza del catalogo:spunti e case histories, in galadini f., meletti c., rebez a. (a cura di), le ricerche del gndt nel campo della pericolosità sismica (1996-1999), cnr-gruppo nazionale per la difesa dei terremoti, roma, 321-331. casti e. (1887) anton ludovico antinori e le sue molteplici opere edite ed inedite, pp. 111-122, l’aquila. cello g., mazzoli s., tondi e., turco e. (1997) active tectonics in the central apennines and possible implications for seismic hazard analysis in peninsular italy, tectonophysics, 272, 43-68: cello g., mazzoli s., tondi e. (1998) the crustal fault structure responsible for the 1703 earthquake sequence of central italy, j. geodyn., 26, 443-460. d'addezio g., masana e., pantosti d. (2001) the holocene paleoseismicity of the aremognacinque miglia fault (central italy). j. seismol. 5, 181-205 . di filippo d. & peronaci f. (1964) la sismicità del “campo fagliato” dell’aterno (terremoto de l’aquila del 24-vi-1958., annali di geofisica, 17, 1: 195-210. galadini f. & galli p. (2000) active tectonics in the central apennines (italy). input data for seismic hazard assessment. natural hazards, 22, 225270. galadini f., galli p., moro m. (2003) paleosismology of silent faults in the central apennines (italy): the campo imperatore fault (gran sasso range fault system). ann. geoph., 46, 793-814. gasperini p. & ferrari g. (1995) stima dei parametri sintetici, in e. boschi et al. (1995), 96-111. gasperini p., bernardini f., valensise g., boschi e. (1999) defining seismogenic sources from historical earthquake felt reports, bull. seism. soc. am., 89, 94-110. giannangeli r (1974) terra di barisciano. japadre ed., l’aquila. giraudi c. and frezzotti m. (1995) paleosismicity in the gran sasso massif (abruzzi, central italy). quaternary international, 25, 81-93. gruppo di lavoro cpti (2004) catalogo parametrico dei terremoti italiani, versione 2004 (cpti04). ingv, bologna. http://emidius.mi.ingv.it/cpti/ ing (1958) bollettino sismico mensile. istituto nazionale di geofisica (ing). marcelli l. & pannocchia g. (1963) l’attività sismica nella zona delle sorgenti del peschiera. annali di geofisica, 15, 4: i° parte, pp. 301-334; xvi, 4: ii° parte, pp. 645-680. mercalli g. (1902) – sulle modificazioni proposte alla scala sismica de rossi – forel, bull. soc. sismol. it., 8, 187-191. monachesi g. & castelli v. (eds.) (1992) sismicità dell'area aquilano-teramana dall’analisi attraverso i cataloghi. rapporto tecnico per la regione abruzzo, osservatorio geofisico sperimentale, macerata, 245 pp. monachesi g. & stucchi m. (a cura di) (1997) dom4.1 un database di osservazioni macrosismiche di terremoti di area italiana al di sopra della soglia del danno, http://emidius.mi.ingv.it/dom/ moro m., bosi v., galadini f., galli p., giaccio b., messina p., sposato a. (2002) analisi paleosismologiche lungo la faglia del m. marine (alta valle dell’aterno): risultati preliminari, il quaternario, 15, 259-270. pantosti d., d’addezio g., cinti f.r. (1996) paleoseismicity of the ovindoli-pezza fault, central apennines, italy: a history including a large, previously unrecorded earthquake in the middle ages (860-1300 ad), j. geophys res., 101, 5937-5959. postpischl d. ed. (1985) catalogo dei terremoti italiani dall’anno 1000 al 1980. consiglio nazionale delle ricerche, progetto finalizzato geodinamica (cnr-pfg). quaderni de “la ricerca scientifica”, n. 1145, 2b, pp. 239. bologna. sieberg a. (1930) geologie der erdbeben, handbuch der geophysik, 2. berlin, pp.550-555. giornali gu (1786), gazzetta universale, 1786, n. 70 (2 settembre 1786), firenze. gf (1786), gazette de france, 1786, n. 78 (29 settembre 1786), parigi. 108 a. rossi, a. tertulliani & m. vecchi gb (1786), gazzetta di bologna, 1786, n. 33 (16 agosto 1786), bologna. gu (1791), gazzetta universale, 1791, n. 12 (8 febbraio 1791), firenze. il messaggero di roma, anno 1958, giugno 25-30. il tempo di roma, anno 1958, giugno 25-30. l’appennino di ascoli piceno, anno 1958, giugno 2428. il giornale d’italia di roma, anno 1958, giugno 23-27. il giornale d’italia cronaca d’abruzzo, anno 1958, giugno 24-30. il paese di roma, anno 1958, giugno 24-27. il giornale d’abruzzo e molise, pescara, giugno-luglio 1958. fonti inedite archivio di stato de l’aquila, gabinetto prefettura, b. 146.xxi.3b.ag. 1950-1958, fasc. scosse di terremoto del 24 giugno 1958. fonogramma dalla compagnia cc di avezzano alla prefettura de l’aquila in data 24 giugno 1958 ore 13,50. archivio di stato de l’aquila, gabinetto prefettura, b. 146.xxi.3b.ag. 1950-1958, fasc. scosse di terremoto del 24 giugno 1958. fonogramma dal comando cc de l’aquila alla prefettura de l’aquila in data 24 giugno 1958 ore 19,40. archivio di stato de l’aquila, gabinetto prefettura, b. 146.xxi.3b.ag. 1950-1958, fasc. scosse di terremoto del 24 giugno 1958. lettera del sindaco di prata d’ansidonia all’ufficio del genio civile de l’aquila in data 11 luglio 1958. archivio di stato de l’aquila, gabinetto prefettura, b. 146.xxi.3b.ag. 1950-1958, fasc. scosse di terremoto del 24 giugno 1958. lettera del sindaco di santo stefano di sessanio alla prefettura de l’aquila in data 28 giugno 1958. archivio di stato de l’aquila, gabinetto prefettura, b. 146.xxi.3b.ag. 1950-1958, fasc. scosse di terremoto del 24 giugno 1958. lettera del sindaco di calascio alla prefettura de l’aquila in data 26 giugno 1958. archivio di stato de l’aquila, gabinetto prefettura, b. 146.xxi.3b.ag. 1950-1958, fasc. scosse di terremoto del 24 giugno 1958. lettera del sindaco de l’aquila alla prefettura de l’aquila in data 26 giugno 1958. archivio di stato de l’aquila, gabinetto prefettura, b. 146.xxi.3b.ag. 1950-1958, fasc. scosse di terremoto del 24 giugno 1958. lettera del sindaco de l’aquila al sovraintendente ai monumenti e gallerie e al ing. capo uff. del genio civile de l’aquila in data 27 giugno 1958. archivio di stato de l’aquila, gabinetto prefettura, b. 146.xxi.3b.ag. 1950-1958, fasc. scosse di terremoto del 24 giugno 1958. lettera del sindaco di san demetrio né vestini all’ ing. capo del genio civile de l’aquila in data 25 giugno 1958. archivio di stato de l’aquila, gabinetto prefettura, b. 146.xxi.3b.ag. 1950-1958, fasc. scosse di terremoto del 24 giugno 1958. lettera del sindaco de l’aquila alla questura de l’aquila in data 25 giugno 1958. archivio di stato de l’aquila, gabinetto prefettura, b. 146.xxi.3b.ag. 1950-1958, fasc. scosse di terremoto del 24 giugno 1958. lettera del sindaco de l’aquila all’ufficio del genio civile de l’aquila in data 25 giugno 1958. archivio di stato de l’aquila, gabinetto prefettura, b. 146.xxi.3b.ag. 1950-1958, fasc. scosse di terremoto del 24 giugno 1958. lettera del sindaco de l’aquila alla prefettura de l’aquila in data 24 giugno 1958. archivio di stato de l’aquila, gabinetto prefettura, b. 146.xxi.3b.ag. 1950-1958, fasc. scosse di terremoto del 24 giugno 1958. telegramma del sindaco di barisciano alla prefettura de l’aquila in data 24 giugno 1958 ore 10,30. archivio di stato de l’aquila, gabinetto prefettura, b. 146.xxi.3b.ag. 1950-1958, fasc. scosse di terremoto del 24 giugno 1958. lettera del direttore dell’istituto dei padri rogazionisti in s. demetrio né vestini al genio civile de l’aquila in data 25 giugno 1958. archivio di stato de l’aquila, gabinetto prefettura, b. 146.xxi.3b.ag. 1950-1958, fasc. scosse di terremoto del 24 giugno 1958. lettera del sindaco di ocre alla prefettura de l’aquila in data 25 giugno 1958 ore 11,35. archivio di stato de l’aquila, gabinetto prefettura, b. 146.xxi.3b.ag. 1950-1958, fasc. scosse di terremoto del 24 giugno 1958. telegramma del capo di gabinetto della prefettura de l’aquila (per il prefetto de gennaro) al ministero dell’interno in data 2 luglio 1958. archivio di stato de l’aquila, gabinetto prefettura, b. 146.xxi.3b.ag. 1950-1958, fasc. scosse di terremoto del 24 giugno 1958. telegramma del comandante della sezione di avezzano dei cc alla prefettura in data 24 giugno 1958. archivio di stato de l’aquila, gabinetto prefettura, b. 146.xxi.3b.ag. 1950-1958, fasc. scosse di terremoto del 24 giugno 1958. lettera del sindaco di bugnara all’ufficio del genio civile de l’aquila in data 2 luglio 1958. archivio di stato de l’aquila, gabinetto prefettura, b. 146.xxi.3b.ag. 1950-1958, fasc. scosse di terremoto del 24 giugno 1958. lettera del comandante interinale del 5° corpo dei vigili del fuoco de l’aquila al genio civile de l’aquila in data 26 giugno 1958. archivio di stato de l’aquila, gabinetto prefettura, b. 146.xxi.3b.ag. 1950-1958, fasc. scosse di terremoto del 24 giugno 1958. lettera del sindaco di san pio delle camere all’ufficio del genio civile de l’aquila in data 1 luglio 1958. archivio di stato de l’aquila, gabinetto prefettura, b. 146.xxi.3b.ag. 1950-1958, fasc. scosse di terremoto del 24 giugno 1958. marconigramma dell’ingegnere capo del genio civile a lavabi, dispes e provoper senza data. archivio di stato de l’aquila, gabinetto prefettura, b. 146.xxi.3b.ag. 1950-1958, fasc. scosse di terremoto del 24 giugno 1958. lettera del sindaco di tione degli abruzzi all’ufficio del genio civile de l’aquila in data 26 giugno 1958. archivio di stato de l’aquila, gabinetto prefettura, b. 146.xxi.3b.ag. 1950-1958, fasc. scosse di terremoto del 24 giugno 1958. lettera del questore de 109studio macrosismico del terremoto ... località prov lat long i bazzano aq 42.337 13.454 70 onna aq 42.327 13.479 70 san demetrio ne' vestini aq 42.288 13.558 70 ocre aq 42.287 13.475 65 poggio picenze aq 42.32 13.541 65 barisciano aq 42.325 13.592 60 calascio aq 42.325 13.696 60 camarda aq 42.391 13.494 60 fossa aq 42.296 13.488 60 l'aquila aq 42.356 13.396 60 paganica aq 42.358 13.473 60 prata d'ansidonia aq 42.277 13.609 60 sant'eusanio forconese aq 42.288 13.524 60 cocullo aq 42.030 13.776 55 rocca di cambio aq 42.233 13.492 55 santo stefano di sessanio aq 42.343 13.644 55 sassa aq 42.352 13.299 55 scoppito aq 42.372 13.256 55 tione aq 42.203 13.636 55 aielli aq 42.081 13.591 50 bugnara aq 42.022 13.862 50 capestrano aq 42.266 13.769 50 località prov lat long i castelnuovo aq 42.295 13.628 50 gagliano aterno aq 42.126 13.701 50 isola del gran sasso te 42.501 13.661 50 molina aterno aq 42.148 13.735 50 montorio al vomano te 42.582 13.629 50 ortona de' marsi aq 41.997 13.728 50 ovindoli aq 42.136 13.516 50 pescina aq 42.025 13.657 50 rocca di mezzo aq 42.205 13.521 50 basciano te 42.595 13.74 45 borgorose ri 42.193 13.234 45 campli te 42.726 13.686 45 castel di ieri aq 42.114 13.743 45 castelli aq 42.489 13.712 45 civitella casanova pe 42.364 13.889 45 cugnoli pe 42.308 13.933 45 farindola pe 42.441 13.824 45 fontecchio aq 42.229 13.606 45 paganico sabino ri 42.190 12.997 45 spoltore pe 42.454 14.138 45 villetta barrea aq 41.776 13.935 45 antrodoco ri 42.415 13.076 40 l’aquila a s. e. il prefetto de l’aquila in data 25 giugno 1958. archivio di stato de l’aquila, gabinetto prefettura, b. 146.xxi.3b.ag. 1950-1958, fasc. scosse di terremoto del 24 giugno 1958. lettera del questore de l’aquila a s. e. il prefetto de l’aquila in data 25 giugno 1958. archivio di stato de l’aquila, gabinetto prefettura, b. 146.xxi.3b.ag. 1950-1958, fasc. scosse di terremoto del 24 giugno 1958. fonogramma del questore de l’aquila a s. e. il prefetto de l’aquila in data 24 giugno 1958. archivio di stato de l’aquila, gabinetto prefettura, b. 146.xxi.3b.ag. 1950-1958, fasc. scosse di terremoto del 24 giugno 1958. fonogramma del questore de l’aquila a s. e. il prefetto de l’aquila in data 24 giugno 1958. archivio di stato de l’aquila, gabinetto prefettura, b. 146.xxi.3b.ag. 1950-1958, fasc. scosse di terremoto del 24 giugno 1958. fonogramma della tenenza dei cc di tagliacozzo alla prefettura de l’aquila in data 24 giugno 1958 ore 14. archivio di stato de l’aquila, gabinetto prefettura, b. 146.xxi.3b.ag. 1950-1958, fasc. scosse di terremoto del 24 giugno 1958. lettera del commissario prefettizio di cocullo al provveditorato alle oo.pp. de l’aquila in data 4 luglio 1958. archivio di stato de l’aquila, gabinetto prefettura, b. 146.xxi.3b.ag. 1950-1958, fasc. scosse di terremoto del 24 giugno 1958. fonogramma della questura de l’aquila al genio civile de l’aquila in data 24 giugno 1958 ore 17,40. archivio di stato de l’aquila, gabinetto prefettura, b. 146.xxi.3b.ag. 1950-1958, fasc. scosse di terremoto del 24 giugno 1958. fonogramma dalla sezione cc di s. demetrio nei vestini al la prefettura de l’aquila in data 24 giugno 1958 ore 21,10. de panfilis m., (1959). relazione sulla sismicità delle zone inscritte nell’elenco allegato al rdl del 2211-1937, n.2105. capitolo vi. commissione per il riesame e l’aggiornamento delle norme tecniche concernenti l’edilizia antisismica. dattiloscritto dell’archivio ingv ucmea, (1958). “cartoline sismiche”. ufficio centrale di meteorologia ed ecologia agraria, presso archivio ingv. 110 ms. ricevuto il 25 gennaio 2005 testo definitivo ricevuto il 30 giugno 2005 ms. received: january 25, 2005 final text received: june 30, 2005 appendice i tabella a piano quotato delle località interessate dal terremoto del 24 giugno 1958 a. rossi, a. tertulliani & m. vecchi 111 località prov lat long i avezzano aq 42.032 13.426 40 campo di giove aq 42.011 14.045 40 cansano aq 42.004 14.013 40 cappadocia aq 42.006 13.282 40 castel castagna te 42.543 13.717 40 catignano pe 42.346 13.951 40 celano aq 42.084 13.546 40 civitella roveto aq 41.914 13.425 40 collarmele aq 42.059 13.628 40 collepietro aq 42.221 13.780 40 corfinio aq 42.124 13.843 40 luco dei marsi aq 41.959 13.471 40 montereale rm 42.522 13.246 40 monterotondo lt 42.054 12.623 40 notaresco te 42.658 13.894 40 offida ap 42.935 13.691 40 palena ch 41.984 14.138 40 petrella salto ri 42.294 13.068 40 raiano aq 42.102 13.814 40 rocca pia ap 41.932 13.977 40 roccafluvione aq 42.861 13.475 40 san benedetto dei marsi aq 42.005 13.622 40 scanno aq 41.903 13.881 40 sulmona aq 42.047 13.929 40 tagliacozzo aq 42.069 13.250 40 teramo te 42.659 13.704 40 torricella sicura te 42.658 13.656 40 turrivalignani pe 42.262 14.029 40 villa celiera pe 42.381 13.859 40 vittorito aq 42.125 13.817 40 amelia tr 42.558 12.413 35 ascoli piceno ap 42.853 13.578 35 leonessa ri 42.566 12.962 35 marcetelli ri 42.226 13.046 35 moscufo pe 42.428 14.055 35 penne pe 42.457 13.928 35 picciano pe 42.474 13.991 35 picinisco fr 41.645 13.868 35 tolentino mc 43.21 13.283 35 trasacco aq 41.958 13.537 35 vicoli pe 42.341 13.898 35 alanno pe 42.296 13.972 30 alvito fr 41.689 13.743 30 ari ch 42.291 14.262 30 arpino fr 41.648 13.610 30 balsorano aq 41.808 13.561 30 bucchianico ch 42.304 14.181 30 campotosto aq 42.558 13.369 30 casalincontrada ch 42.290 14.135 30 castel di lama ap 42.873 13.707 30 castel di sangro aq 41.784 14.108 30 località prov lat long i chieti ch 42.351 14.168 30 cittaducale ri 42.386 12.949 30 civita castellana vt 42.293 12.413 30 collecorvino pe 42.458 14.015 30 fara san martino ch 42.090 14.206 30 gioia dei marsi aq 41.953 13.693 30 guardiagrele ch 42.190 14.222 30 isola del liri fr 41.680 13.579 30 loreto aprutino pe 42.433 13.988 30 mandela rm 42.027 12.922 30 manoppello pe 42.257 14.060 30 monsampietro morico ap 43.067 13.556 30 nereto te 42.819 13.817 30 orsogna ch 42.219 14.283 30 palata cb 41.890 14.785 30 palestrina rm 41.839 12.891 30 palombara sabina rm 42.066 12.766 30 penna in teverina tr 42.493 12.355 30 pereto aq 42.059 13.101 30 pescara pe 42.464 14.214 30 rieti ri 42.404 12.867 30 rivisondoli aq 41.87 14.067 30 roccaraso aq 41.847 14.079 30 roma rm 41.895 12.482 30 settefrati fr 41.670 13.850 30 sora fr 41.718 13.613 30 tollo ch 42.339 14.319 30 vacri ch 42.296 14.231 30 villa vallelonga ch 41.869 13.623 30 zagarolo rm 41.839 12.831 30 arsoli rm 42.041 13.019 20 carpineto romano rm 41.605 13.084 20 cassino fr 41.489 13.831 20 ferentino fr 41.691 13.254 20 frosinone fr 41.636 13.341 20 genzano di roma rm 41.707 12.688 20 lanciano ch 42.230 14.390 20 paliano fr 41.805 13.057 20 pescasseroli aq 41.808 13.789 20 vieste fg 41.882 16.18 20 albano laziale rm 41.728 12.659 0 allerona tr 42.812 11.974 0 altino ch 42.102 14.331 0 alviano tr 42.59 12.297 0 alvignano ce 41.245 14.338 0 apice bn 41.118 14.931 0 aprilia lt 41.594 12.65 0 aquino fr 41.493 13.701 0 atina fr 41.619 13.800 0 aversa ce 40.974 14.207 0 bagnoli del trigno is 41.703 14.457 0 segue tabella a studio macrosismico del terremoto ... località prov lat long i bagnoregio vt 42.626 12.095 0 baschi tr 42.699 12.217 0 belforte del chienti mc 43.163 13.238 0 caianello ce 41.294 14.086 0 caiazzo ce 41.177 14.367 0 campoli appennino fr 41.737 13.679 0 canino vt 42.465 11.750 0 caprarola vt 42.327 12.238 0 casacalenda cb 41.740 14.849 0 castel campagnano ce 41.182 14.452 0 castel gandolfo rm 41.747 12.651 0 castel viscardo te 42.755 12.002 0 castelraimondo tr 43.209 13.057 0 castiglione in teverina vt 42.646 12.204 0 castorano ap 42.898 13.727 0 ceccano fr 41.568 13.334 0 cerreto sannita bn 41.285 14.560 0 civitella d'agliano vt 42.293 12.188 0 collelongo aq 41.885 13.584 0 contigliano ri 42.411 12.769 0 corbara tr 42.705 12.228 0 cori lt 41.642 12.916 0 dragoni ce 41.273 14.304 0 fabro tr 42.863 12.013 0 faeto fg 41.324 15.162 0 fermo ap 43.161 13.716 0 filignano is 41.544 14.055 0 fondi lt 41.358 13.427 0 formia lt 41.261 13.617 0 gaeta lt 41.218 13.568 0 gradoli vt 42.643 11.855 0 guglionesi cb 41.912 14.914 0 itri lt 41.29 13.532 0 jelsi cb 41.518 14.796 0 latina lt 41.467 12.903 0 macerata mc 43.3 13.453 0 maddaloni ce 41.038 14.387 0 manfredonia fg 41.623 15.908 0 località prov lat long i massafra ta 40.589 17.113 0 montaquila is 41.566 14.113 0 monte s. biagio ap 41.353 13.352 0 montefalcone appennino ap 42.987 13.46 0 montegallo ap 42.846 13.327 0 montegiorgio aq 43.130 13.537 0 morcone bn 41.34 14.664 0 norma lt 41.584 12.972 0 orsara di puglia fg 41.281 15.266 0 orvieto tr 42.719 12.113 0 pescocostanzo aq 41.889 14.065 0 pietrabbondante is 41.747 14.386 0 pioraco mc 43.178 12.986 0 pontecorvo fr 41.456 13.667 0 priverno lt 41.473 13.181 0 riofreddo rm 42.06 13.000 0 roseto valfortore fg 41.372 15.096 0 san giorgio la molara bn 41.27 14.919 0 san nicola manfredi bn 41.071 14.825 0 san severo fg 41.685 15.381 0 san venanzo tr 42.869 12.267 0 s. maria capua vetere ce 41.078 14.256 0 sefro mc 43.146 12.949 0 sepino cb 41.407 14.619 0 sermoneta lt 41.549 12.985 0 serrapetrona mc 43.176 13.189 0 solopaca bn 41.192 14.549 0 sparanise ce 41.190 14.097 0 teano ce 41.251 14.068 0 terracina lt 41.288 13.233 0 torre s. severo tr 42.671 12.063 0 troia fg 41.361 15.309 0 tuscania vt 42.420 11.870 0 vallecorsa fr 41.444 13.405 0 vallerotonda fr 41.549 13.914 0 venafro is 41.485 14.044 0 villamagna aq 42.332 14.237 0 volturino fg 41.478 15.125 0 112 segue tabella a a. rossi, a. tertulliani & m. vecchi imp.distefano& the holocene marine depositional event in the historical centre of palermo enrico di stefano, sergio bonomo & alessandro incarbona università degli studi di palermo dipartimento di geologia e geodesia corso tukory , 131 90134 palermo edist@unipa.it abstract: di stefano e., bonomo s., incarbona a., the holocene marine depositional event in the historical centre of palermo. (it issn 0394-3356, 2004). recent data have pointed out that, above the classical depositional sequence of the quaternary marine sediments of the palermo coastal plain, post-tyrrhenian sediments occur. in order to determine the age of these sediments and to confirm the deposition of a recent sedimentary cycle, microfossil assemblage of several samples, coming from geognostic drillings, have been analysed. using the calcareous nannofossil ecobiozone scheme recently proposed for the last deglaciation of the central mediterranean (sicily channel), examined sediments can be ascribed to the holocene. radiocarbon analysis confirmed such an attribution providing a more accurate stratigraphic determination. riassunto: di stefano e., bonomo s., incarbona a., the holocene marine depositional event in the historical centre of palermo. (it issn 0394-3356, 2004). studi recenti hanno indicato come al di sopra della classica sequenza del quaternario marino della piana di palermo ricorra, in alcuni siti del centro storico, un limitato spessore di depositi marini di età post-tirreniana. con lo scopo di precisare l’età di tali depositi sono state studiate le associazioni di microfossili di campioni provenienti da sondaggi geognostici. utilizzando lo schema ecobiozonale a nannofossili calcarei recentemente proposto per l’ultima deglaciazione nel mediterraneo centrale (canale di sicilia) detti depositi contengono nannoflore attribuibili all’olocene. un'analisi al radiocarbonio ha confermato tale attribuzione, limitando alla parte bassa dell'olocene la pertinenza stratigrafica di tali depositi. keywords: holocene, calcareous nannofossils, foraminifera, radiocarbon convention age, northern sicily. keywords: olocene, nannofossili calcarei, foraminiferi, età radiocarbonio, sicilia settentrionale. il quaternario italian journal of quaternary sciences 17(2/1), 2004, 285-291 introduction since the last century, palermo’s coastal plain has been considered as a classical reference for marine quaternary studies. after doderlain (1872), several authors developed studies on pleistocene chronostratigraphy, biostratigraphy and palaeoclimatology, based on these marine sediments (de stefani 1891-2; gignoux 1913; emiliani et al. 1958; gradstein 1970; ruggieri & sprovieri 1977; di stefano & rio 1981; buccheri 1984). the central part of the coastal plain consists of a series of little plateau, moulded by marine action during the late quaternary. during the last glaciation (würm), they were isolated from each other for the deepening of two converging river-beds (kemonia fossil river and papireto fossil river). till historic age, when the town was confined within the “paleopoli” and the “neapoli”, the mouths of these two rivers flowed together in a deep inlet used as a seaport (fig. 1). then these rivers were hidden by human settlement, even though their course is also observable by the topographical and town-planning structure of the historical centre (fig. 2). several geognostic drillings were carried out during the last decades, to safeguard the main sites of monumental interest, contributing to improving the stratigraphic knowledge of the area (todaro 1995; giammarinaro et al. 2000). micropaleontological data based on calcareous nannofossils and foraminifera, coming from several core segments, will now be presented. geological framework marine quaternary sediments sett led in palermo’s coastal plain can be ascribed to two main lithologies: silty-clays and/or calcarenites having a maximum thickness of about 80-100 metres. they cover the tectonic units of panormide carbonate platform and imerese basin, which are orogenetically deformed. these tectonic units are overlained by the oligo-miocene numidian flysch deposit (catalano et al. 1998). roughly, the calcarenitic facies lies on the siltyclays, except for the eastern part of the coastal plain, where the fossiliferous silty clays outcrop (acqua dei corsari and cava puleo – ficarazzi – sicilian stratotype) (fig. 3). these two litho-facies are part of a depositional sequence, chronostratigraphically spanning the upper part of the emilian, the entire sicilian and the lowermost part of the medium pleistocene (di stefano & rio 1981; catalano et al. 1998). recent micropaleontological data pointed out, for the first time, that the classical sequence just described is overlained by post-tyrrhenian marine sediments (di stefano 1998a). the aim of the present note is to specify the age of post-tyrrhenian marine sediments, making use of a recent calcareous nannofossil ecobiozonation (sprovieri et al. 2003) and of a 14c radiocarbon dating. 286 e. di stefano, s. bonomo & a. incarbona materials and methods analysed material comes from two cores (indicated as cores 1 and 2 in fig. 2). core 1 was recovered in the northern part of a depression, known as “conca del papireto”, bordering a promontory of sicilian calcarenites where the paleopoli (vii-viii century b.c.) was founded. the studied materials were sampled at -16 and -4 metres from the roadway. the second drilling is located in a street (via dei candelai) whose line coincides with the last part of the papireto bed-river, reclaimed in the xvi century. the studied samples were collected at -22 and -16 metres from the roadway. the calcareous nannofossil assemblages were studied following the standard procedure on the smear slide preparations and without performing any process that could affect the natural status of the sediment. quantitative analyses were conducted using a polarized microscope (transmitted light and crossed nicols) at about 1000 x magnification. the occurrence of emiliania huxleyi was checked by scanning electron microscope (sem) observations. fig 1 satellite photo of palermo. in white the traces of kemonia and papireto fossil river-beds. arrow points out the location of the “paleopoli neapoli” (modified from la duca 1999). fig 2 city plan of the historical centre of palermo and location of the geognostic drillings. in grey the track of the fossil river-beds hidden by human settlement. the foraminifera study was performed washing about 25 cc of dried sediments with a 63 µm sieve. to evaluate the absolute age (14c method) of the post-tyrrhenian fossiliferous clay level of “conca del papireto”, about thirty specimens of epiphyte benthic foraminifera (cibicides lobatulus, elphidium crispum, rosalina sp.) were picked. the selected specimens were perfectly preserved and at a different ontogenetic development degree. the analysis was performed at the center for accelerator mass spectrometry of lawrence (livermore national laboratory). results conca del papireto examined samples are representative of two lithologic levels located at -16 and -4 metres. they are respectively grey sandy-clays with fossils and vegetable remains and blue clays with small molluscs, echinoderm remains and vegetable carbonaceous remains. calcareous nannofossils: (-16 metres sample) examined sample indicated the total absence of autochtonous nannofloras. only very rare specimens of reworked paleogenic taxa, coming from the numidian flysch deposit, were observed. (-4 metres sample) the calcareous nannofossil assemblage is scarcely diversified but rich in specimens, characterized by the dominance of e. huxleyi (fig. 4a). quantitative analyses, by countings on the first 300 specimens, pointed out that this taxon occurs with abundance values exceeding 45%. common specimens of gephyrocapsa oceanica (fig. 4b) and rare ones of small gephyrocapsa and braarudosphaera bigelowii were also detected. genus helicosphaera occurs with common helicoliths belonging to three different species. on the basis of the above compositional and quantitative data, the assemblage was ascribed to the mnn21b biozone (rio et al. 1990). moreover, quite a shallow marine environment with a temperate climate can be supposed. a slightly lowered salinity can be invoked on the basis of the occurrence of b. bigelowii that has been often reported as a species of coastal environment and/or low salinity (bukry 1971; müller 1979). again specimens of reworked paleogenic taxa (sphenolithus conicus and sphenolithus sp.) occur. 287the holocene marine depositional ... the following taxa were recognized: braarudosphaera bigelowii calcidiscus leptoporus emiliania huxleyi gephyrocapsa oceanica small gephyrocapsa helicosphaera hyalina helicosphaera carteri helicosphaera wallichii foraminifera: (-16 metres sample) only few species and specimens of coastal benthic foraminifera were observed, representative of a very reduced bathyfig 3 simplified geologic map of palermo's coastal plain and schematic stratigraphic columns (modified from abate b. et al. 1982). fig 4 a emiliania huxleyi (sem). b gephyrocapsa oceanica (mop, x nicols). 288 metry. among them ammonia beccarii, elphidium crispum and rare miliolids. (-4 metres sample) a diversified assemblage, with well preserved specimens at different ontogenetic levels, were observed. benthic foraminifera are very abundant, characterized by the dominance of epiphyte taxa: planorbulina mediterranensis, rosalina sp., cibicides lobatulus together with a. beccarii, e. crispum and miliolids. this assemblage testifies an evolution in the depositional environment towards deeper conditions (several tens of metres). such a consideration is in agreement to the occurrence of very few specimens of planktonic foraminifera: globigerina bulloides and globorotalia inflata. via dei candelai examined samples are representative of two sedimentary levels located at -22 and -16 metres. they are respectively representative of fossiliferous grey sandyclays and dark silty-clays with small molluscs. calcareous nannofossils: (-22 metres sample) the nannofloral assemblage is not well diversified with over 45% of small placoliths of e. huxleyi. g. oceanica and b. bigelowii are also significantly present. on these basis the assemblage might be again considered as indicative of the biozone mnn21b and belonging to a stratigraphic level correlatable with the considered higher sample of “conca del papireto”. (-16 metres sample) furthermore, the calcareous nannofossil assemblage resulted less diversified, almost entirely constituted by small placoliths of e. huxleyi and representative of the biozone mnn21b. stratigraphy in the two investigated sites, calcareous nannofossil assemblages pertaining to the biozone mnn21b were detected. such data can be considered as an innovation relative to the known stratigraphic framework. firstly, the younger marine sediments which settled in the coastal plain were ascribed to the blue clays and/or to the calcarenites that are in transgression on the oligo-miocene deposits (numidian flysch). both litofacies belong to a sedimentary cycle begun with the marine transgression of the emilian substage and they are bounded in the upper part by a erosive surface that is surely more recent than the marine isotopic stage (mis) 22 (di stefano & rio 1981; buccheri 1984; di stefano 1998b). the first mention of the existence of more recent marine sediments, although with a relatively little thickness, is linked to the detection of e. huxleyi acme in sediments referable to the mnn21b biozone (di stefano 1998a). this biozone covers the uppermost part of the latest pleistocene and holocene. using recent biochronologic data, mainly obtained by sediments recovered during the cruise of the ocean drilling program (odp leg 160), e. huxleyi's increase in abundance always occurs above mis 5 and sapropel s3 in the mediterranean sea (castradori 1993; sanvoisin et al. 1993; flores et al. 1997; di stefano 1998b; sprovieri et al. 1998; de kanel et al. 1999). therefore these sediments are an insight that a post-tyrrhenian sea re-entrance occurred, at least in the central sector of palermo’s coastal plain. quantitative abundance data on the calcareous nannofossil assemblages of the uppermost late pleistocene-holocene and the recently proposed ecobiozonation of the last ca. 20 kyrs in the sicily channel (odp-site 963) strongly enhanced the stratigraphic resolution of the upper part of the biozone mnn21b. on these basis, the above mentioned transgression of sea water on the coastal plain can be restricted to the holocene. infact, the occurrence of several specimens of g. oceanica, is compatible only with ecozones 3n, 2n and 1n (sprovieri et al. 2003). this taxon marks a re-entrance event just above the base of the holocene (di stefano & incarbona 2004) (fig. 5) after an interval of virtual absence that covers the entire würm (di stefano & incarbona unpublished data). age dating in order to reach a more accurate age determination of the above mentioned depositional event, a 14c radiocarbon analysis was performed. about thirty specimens of epiphyte benthic foraminifera (c. lobatulus, e. crispum and rosalina sp.) at a different ontogenetic development were selected. the obtained result was 7780 ± 60 b.p. (radiocarbon convention age) (tab. 1). fig 5 quantitative distribution pattern of gephyrocapsa oceanica in the sedimentary record of odp hole-963d compared with calcareous nannofossil ecozones, with the stages of the event stratigraphy and with the stratigraphic subdivision of mangerud et al. 1974. on the right the available age control based on three age determinations (radiocarbon convention age) is reported (modified from di stefano & incarbona 2004). e. di stefano, s. bonomo & a. incarbona 289 so the sediments can be referred to the lower part of the holocene during the last phase of the deglaciation, while the sea-level was reaching the maximum highstand (bjørck et al. 1998). such an age is nearly correspondent to that obtained in the middle part of the ecozone 2n (7510 ± 60 b.p. radiocarbon convention age) of sprovieri et al. (2003) (fig. 5). discussion the marine sedimentation established at least in the central sector of palermo’s coastal plain at about 7.8 kyrs b.p. (radiocarbon convention age), provides remarkable indications on the possible depositional history of this coastal region. recent palaeoclimatic studies outlined the sequence of the most important fluctuations in the climatic system during the last deglaciation, mainly on the basis of the isotopic record of greenland ice cores (chappelaz et al. 1990; alley et al. 1993; bond et al. 1993; grootes et al. 1993). a significant warming event marked the end of the younger dryas (gs-1) (fig. 6) and characterized the lower part of the holocene. as a consequence a fast sea level raising has been reported on the eustatic curves. the raising of the sea level was evaluated in about 120 metres in coincidence of the deglaciation culmination (fairbanks, 1989). the radiometric age obtained for “conca del papireto” sample, links the deposition of holocene palermo’s coastal plain sediments to the deglaciation culmination event. sea waters flowed on the coastal sectors of the plain using as a preferential way the fossil river-beds of kemonia and papireto, lowered during the glacial würm period. further samples, coming from small segments of cores of the historical centre, with nannofloras again referable to the holocene has been recently recovered, demonfig 6 δ18o profile from greenland ice core gisp2, compared with the classical sequence of events related to the last deglaciation (mangerud et al. 1974). tab. 1 report on 14c radiocarbon analysis, performed on the papireto sample the holocene marine depositional ... 290 strating that the sea re-entrance interested several places and had therefore a significant extension (fig. 2). the collected foraminiferal data infers that during this sea water re-entrance, a water column estimated in several tens of metres existed on the sea floor in the papireto site. conclusions micropaleontological analyses based on calcareous nannofossils and foraminifera were carried out on some samples of the historical centre of palermo, selected as possible indicators of a post-tyrrhenian depositional sequence. samples within the papireto fossil river-beds are characterized by the dominance of e. huxleyi together with the occurrence of several specimens of g. oceanica. they are compatible with holocene nannofossil ecozones. moreover, faunistic and floristic assemblages point out a shallow water marine environment and a temperate climate. an age determination was performed and the result was 7780 ± 60 yrs bp (radiocarbon convention age). it confirms that, in this area, marine sediments were deposited during the lower part of the holocene. this age is indicative of the last phase of the deglaciation and is almost coincident with the maximum high-stand of the sea level. we suggest that the sea water flowed on the coastal plain of the historical centre of palermo using as a preferential way the kemonia and papireto fossil riverbeds, deeply eroded during the würm glacial period. acknowledgments studied samples were provided by “studio diagnostico del centro storico della città di palermo” and miur project, coordinators r. catalano and m. s. giammarinaro. we are thankful to them and to their coworkers. thanks are also due to sicilsonde s.n.c. for providing the sample of “conca del papireto”. this research has been supported by miur ex 60% grants to e. di stefano. references abate b., catalano r. & renda p. (1982) i monti di palermo. in: catalano r. & d'argenio b. guida alla geologia della sicilia occidentali. società geologica italiana, 1° centenario della società geologica italiana: 37-41. alley r.b., meese d.a., shuman a.j., gow a.j., taylor k.c., grootes p.m., white j.w.c., ram m., waddington e.d., mayewski p.a. & zielinski g.a. (1993) abrupt accumulation increase at the younger dryas termination in the gisp2 ice core. nature, 362: 527-529. bjørck s., walker m.j.c., cwynar l.c., johnsen s., knudsen k.l., lowe j.j., wohlfarth b., & intimate members (1998) an event stratigraphy for the last termination in the north atlantic region based on the greenland ice-core record: a proposal by the intimate group. journal of quaternary sc., 13: 283-292. bond g., broecker w., johnsen s.j., mcmanus j., labeyrie l., jouze j. & bonani g. (1993) correlation between climate records from north atlantic sediments and greenland ice. nature, 365: 143-147. buccheri g. (1984) pteropods as climatic indicators in quaternary sequences: a lower-middle pleistocene sequence outcropping in cava puleo (ficarazzi, palermo, italy) . palaeogeogr., palaeoclimatol., palaeoecol., 45 (1): 75-86. bukry d. (1971) coccoliths as paleosalinity indicators – evidence from the black sea. u. s. geol. survey, 353-363. castradori d. (1993) calcareous nannofossil biostratigraphy and biochronology in eastern mediterranean deep-sea cores. riv. ita. paleo. strat., 99: 107-126. catalano r., di stefano e., sulli a., vitale f.p., infuso s. & vail p.r. (1998) sequences and systems tracts calibrated by high-resolution bio-chronostratigraphy: the central mediterranean pliopleistocene record. in: mesozoic and cenozoic sequence stratigraphy of european basins, s.e.p.m. special publication, 60: 155-177. chappelaz j., blunier t., ratnaud d., barnola j.m., schwander j. & stauffer b. (1993) synchronous change in atmospheric ch4 and greenland climate between 40 and 8 kyr bp. nature, 366: 443445. de kaenel e., siesser w.g. & murat a., (1999) pleistocene calcareous nannofossil biostratigraphy and the western mediterranean sapropels, sites 974 to 977 and 979. in zahn r., comas m.c. & klaus a., (eds). proc. odp, scient. res., 161: 159-184. de stefani c. (1891-2) les terraines tertiaires superieurs du bassin de la mediterranee. ann soc. geol. belgique, 18: 201-419. di stefano e. (1998a) i sedimenti marini post tirreniani del centro storico di palermo. atti 79° congresso soc. geologica italiana, b: 419-420. di stefano e. (1998b) calcareous nannofossil quantitative biostratigraphy of holes 963e and 963b (eastern mediterranean) . in emeis k.-c., robertson a.h.f., richter c. & camerlenghi a. (eds), proc. odp, scient. res., 160: 99-112. di stefano e. & incarbona a. (2004) high resolution palaeoenvironmental reconstruction of odp hole 963d (sicily channel) during the last deglaciation, based on calcareous nannofossils. marine micropaleontology, 52: 241-254. di stefano e. & rio d. (1981) biostratigrafia a nannofossili e biocronologia del siciliano nella località tipo di ficarazzi (palermo – sicilia). acta naturalia de l’ateneo parmense, 17: 97-111. doderlain p. (1872) note illustrative della carta geologica del modenese e del reggiano. memoria iii: 74 pp. emiliani c., giannotti a. & mayeda t. (1958) analisi isotopica dei foraminiferi siciliani delle argille di ficarazzi, palermo. quaternaria, 5: 135-141. fairbanks r.g. (1989) a 17000-year glacio-eustatic sea level record: influence of glacial melting rates on the younger dryas event and deepocean circulation. nature, 342: 637-642. e. di stefano, s. bonomo & a. incarbona flores j.-a., sierro f.j., francès g. & vàzquez a. (1997) the last 100,000 years in the western mediterranean: sea surface water and frontal dynamics as revealed by coccolithophores. marine micropal., 29: 351-366. giammarinaro m.s., canzoneri v., spotorno r., sulli a. & catalano r. (2000) historical centre of palermo: effects of the lithotecnical successions on the bulk contribution to seismic response. mem. soc. geol. it., 55: 439-447. gignoux m. (1913) les informations marines pliocenes et quaternaires de l'italie du sud et de la sicilie. ann. univ. lyon, 36. gradstein f.m. (1970) foraminifera from the type sicilian at ficarazzi, sicily (lower pleistocene). kon. ned. ak. wetern. proc., ser b. 73 (4): 29 pp. grootes p.m., stuiver m., white j.w.c., johnsen s. & jouzel j. (1993) comparison of oxygen isotope records from the gisp2 and grip greenland ice cores. nature, 366: 552-554. la duca r. (1999) cd rom storia di palermo. l'epos, i. mangerud j., andersen s.t., berglund b.e. & donner j.j. (1974) quaternary stratigraphy of norden: a proposal for terminology and classification. boreas, 3: 109-128. müller c. (1979) les nannofossiles calcaires. la mer pelagienne, 210-220. rio d., raffi i. & villa g. (1990) pliocene–pleistocene calcareous nannofossil distribution patterns in the western mediterranean. in kastens k. a., mascle j. et al., proc. odp, scient. res., 107: 513-533. ruggieri g. & sprovieri r. (1977) a revision of italian pleistocene stratigraphy. geologica romana, 16: 131-139. sanvoisin r., d’onofrio s., lucchi r., violanti d. & castradori d. (1993) 1 ma paleoclimatic record from the eastern mediterranean-marflux project: the first results of micropaleontological and sedimentological investigation of a long piston core from the calabrian ridge. il quaternario, 6: 169188. sprovieri r., di stefano e., incarbona a. & gargano m.e. (2003) high-resolution record of the last deglaciation in the sicily channel based on foraminifera and calcareous nannofossil quantitative distribution. palaeogeogr., palaeoclimatol., palaeoecol., 202: 119-142. sprovieri r., di stefano e., howell m., sakamoto t., di stefano a. & marino m., (1998) integrated calcareous plankton biostratigraphy and ciclostratigraphy at site 964. in emeis k.c., robertson a.h.f., richter c. & camerlenghi a. (eds), proc. odp, scient. res., 160. todaro p. (1995) palermo: geologia del centro storico. atlante geologico-stratigrafico. dario flaccovio editore, 119 pp. 291 ms. ricevuto il 21 maggio 2004 testo definitivo ricevuto il 28 settembre 2004 ms. received: may 21, 2004 final text received: september 28, 2004 the holocene marine depositional ... imp. giraudi ii ddeeppoossiittii aalllluuvviioonnaallii oolloocceenniiccii ddii ccaammppoo iimmppeerraattoorree ((mmaassssiicccciioo ddeell ggrraann ssaassssoo –– aabbrruuzzzzoo)) ccaarrlloo ggiirraauuddii enea c.r. casaccia, c.p. 2400, 00100 roma a.d. riassunto il rilevamento geologico e geomorfologico di dettaglio eseguito sui sedimenti e sui terrazzi alluvionali di campo imperatore ha permesso di distinguere varie fasi di sedimentazione risalenti all’olocene. la scansione cronologica dell’attività alluvionale, ottenuta per mezzo di datazioni radiocarbonio su paleosuoli e sedimenti lacustri, dimostra come il trasporto solido nei corsi d’acqua sia avvenuto, seppure con diversa energia e con brevi fasi di interruzione, lungo gran parte dell’olocene. la fase di sedimentazione alluvionale olocenica che forma il primo terrazzo è avvenuta tra 12.100±100 bp (14.410÷13.770 cal bp) e un periodo successivo a 7060±70 bp (8120÷7910 cal bp) e precedente a 5420±80 bp (6400÷5950 cal bp). la sedimentazione del corpo alluvionale che forma il secondo terrazzo si è verificata tra 7060±70 bp (8120÷7910 cal bp) e 4070±70 bp ( 4830÷4410 cal bp). le alluvioni che formano il terzo terrazzo si sono deposte in un periodo compreso tra 4070±70 bp (4830÷4410 cal bp) e un momento successivo a 2130±50 bp (2190÷1990 cal bp) e precedente a 1410±40 bp (580÷689 ad). la sedimentazione delle alluvioni che formano il quarto terrazzo è avvenuta tra 1410±40 bp (580÷689 ad) ed un periodo più recente degli anni 1440÷1640 ad. il quinto terrazzo è stato formato dall’attività alluvionale recentissima. appare poi evidente la correlazione tra fasi di sedimentazione alluvionale individuate a campo imperatore e quelle riconosciute in altre località dell’appennino centrale e settentrionale; inoltre vi è una notevole coincidenza cronologica anche con le fasi di espansione del ghiacciaio del calderone e di alcuni ghiacciai alpini. abstract the campo imperatore holocene alluvial sediments (gran sasso massif – central italy) the detailed geological and geomorphological survey carried out on campo imperatore alluvial sediments and terraces enabled some holocene depositional phases to be recognised. the chronological framework has been obtained through radiocarbon datings on palaeosols and lacustrine sediments and shows that alluvial deposition took place, even if with some interruptions, during most of the holocene period. the deposition of the alluvial unit forming the first terrace took place between 12.100±100 bp (14.410÷13.770 cal bp) and a period more recent than 7060±70 bp (8120÷7910 cal bp) and older than 5420±80 bp (6400÷5950 cal bp). the second terrace alluvial sequence has been dated between 7060±70 bp (8120÷7910 cal bp) and 4070±70 bp ( 4830÷4410 cal bp). the deposition of the alluvial sediments forming the third terrace occurred between 4070±70 bp (4830÷4410 cal bp) and a period following 2130±50 bp (2190÷1990 cal bp) and preceding 1410±40 bp (580÷689 cal ad). the alluvial sediments forming the fourth terrace were deposited between 1410±40 bp (580÷689 cal ad) and a period following 1440÷1640 cal ad. the fifth terrace has been formed by very recent alluvial activity. thanks to the dating of the sediments one can observe a correlation between alluvial sedimentation at campo imperatore and in other central and northern apennine sites, and between the start of the alluvial phases and the advance of the calderone glaciers (on the gran sasso massif) and some alpine glaciers. the campo imperatore alluvial sedimentation appears strongly linked to the environmental impact produced by climatic oscillations, which affected both mediterranean and alpine areas, also affecting glaciers that cannot be changed by human activity. even if there is proof of fires that developed during prehistoric times, the data available show that the human impact was not able to produce any instability of the slopes and alluvial sedimentation phases not linked to the climatìc variations. the large, thick alluvial units outcropping at campo imperatore seem strongly linked also to the presence of cataclastic rocks on the slope surrounding the northern boundary of the plain; the gullies affecting the cataclasites were inactive only during short periods, when morphological stability prevailed and soils developed. the considerable detail regarding phases of sedimentation and pedogenesis preserved on the deposits (younger than the vi-vii centuries ad) forming the iv terrace seems due to the morphology of the site: the place is very flat and the water in the streams loses its energy, the sediments are mainly thin and between them lie gentle erosion surfaces. the same detail was not found in the older alluvial units lying in different places where the streams flowed with greater energy, the grain size was larger and erosional phases stronger. parole chiave: olocene, fasi alluvionali, variazioni climatiche, gran sasso, appennini. keywords: : holecene, alluvial phases, climatic variations, gran sasso massif, apennines. il quaternario italian journal of quaternary sciences 1166(2), 2003, 197-205 11.. iinnttrroodduuzziioonnee campo imperatore è un altopiano, lungo circa 18 km, largo da 1 a 4 km, che occupa il fondo di una conca chiusa tettonico-carsica posta a quote comprese tra 1850 e 1450 m. il drenaggio superficiale presente sull'altopiano termina negli inghiottitoi presenti nella porzione sud-orientale dell'area. tuttavia solo una piccola parte della rete di drenaggio appare attiva attualmente: si tratta di corsi d'acqua stagionali che defluiscono quasi esclusivamente nelle porzioni terminali delle valli poste ai margini della piana ove affiora il substrato. quando l'acqua raggiunge gli apici dei conoidi alluvionali viene infatti assorbita dai sedimenti grossolani. lo scorrimento di acqua negli alvei presenti sui conoidi avviene generalmente, insieme ad un notevole trasporto solido, in occasione di eventi piovosi eccezionali o nel corso di rapide fasi di scioglimento delle nevi dopo inverni molto 198 c. giraudi nevosi. tuttavia a giudicare dall'inerbimento della depressione che circonda gli inghiottitoi carsici e dall'assenza di alvei ben identificabili, si può arguire che attualmente l'acqua può arrivare agli inghiottitoi solo in rare occasioni, con bassa energia e senza carico solido. scopo del presente lavoro è lo studio e la datazione dei sedimenti alluvionali di campo imperatore per ottenere informazioni di carattere climatico-ambientale necessarie al completamento della ricostruzione dell'evoluzione paleoclimatica dell' area. i sedimenti alluvionali, rappresentati schematicamente sul foglio teramo della carta geologica d'italia a scala 1:100.000 (servizio geologico d'italia, 1963) e in demangeot (1965) sono stati in parte datati con metodi radiometrici per la prima volta da frezzotti & giraudi (1990), cartografati con maggiore dettaglio da frezzotti & giraudi (in ghisetti & vezzani, 1990) e descritti da giraudi (1994). ulteriori datazioni interessanti per l'inquadramento cronologico dei sedimenti alluvionali e fluvioglaciali di campo imperatore sono riportati in giraudi & frezzotti (1997) ed in giraudi (1998; 2001) nel presente lavoro verrà discusso l'inquadramento cronologico di alcuni depositi alluvionali utilizzando dati tratti dalla letteratura e nuove datazioni radiocarbonio. 22.. ii sseeddiimmeennttii aalllluuvviioonnaallii ddii ccaammppoo iimmppee-rraattoorree i sedimenti alluvionali occupano buona parte della porzione centrale ed orientale di campo imperatore, e formano alvei di corsi d'acqua stagionali, conoidi alluvionali e varie spianate terrazzate. gli estesi conoidi alluvionali, in particolare, rappresentano una componente assai evidente del paesaggio dell'altopiano. essi si trovano quasi esclusivamente al suo margine settentrionale: anche se spesso i conoidi si trovano allo sbocco di bacini idrografici poco estesi, hanno dimensioni rilevanti sicuramente a causa della presenza, sui versanti, di un'ampia fascia di cataclasiti facilmente erodibili. ghisetti & vezzani (1986;1990) e giraudi (1994) hanno evidenziato che le superfici dei conoidi si sono formate in varie fasi: nella porzione centro-orientale di campo imperatore si sarebbero formate in cinque fasi, mentre nella porzione occidentale, occupata da un esteso ghiacciaio nel corso dell'ultimo massimo glaciale, si sarebbero sviluppate in quattro fasi. i conoidi sono formati da varie parti incassate una nell'altra, caratterizzate da suoli con diverso grado di sviluppo e, in certi casi, da un diverso sviluppo della copertura vegetale. in base alle datazioni radiometriche riportate da frezzotti & giraudi (1990) e giraudi & frezzotti (1997) appare evidente che le più antiche superfici dei conoidi presenti nella porzione intermedia ed orientale di campo imperatore sono da attribuire all'ultimo massimo glaciale e quindi le fasi successive debbono essere avvenute nel tardiglaciale e nell’olocene. la ricostruzione dell’evoluzione morfologica dei conoidi alluvionali e delle fasi di sedimentazione postglaciali è stata resa possibile dal rilevamento geologicogeomorfologico di dettaglio, dal rinvenimento di parecchi affioramenti e dalla datazione di molti campioni di paleosuolo effettuata col metodo del 14c. di seguito vengono riportate le descrizioni dei siti e delle successioni alluvionali che hanno permesso di datare le fasi di sedimentazione oloceniche di campo imperatore. 22..11.. iill ccoonnooiiddee ddii vvaallllee ffoorrnnaaccaa allo sbocco della valle fornaca, (2a in fig. 1) tra i monti prena e camicia, è presente un conoide terrazzato, la superficie del quale si è formata in cinque diverse fasi: il corpo principale del conoide (ia fase) è costituito (frezzotti & giraudi, 1990; giraudi & frezzotti, 1997) da alternanze di ghiaie sabbiose e sabbie con intercalazione di suoli (fig. 2a) datati rispettivamente 31.500±550 bp e 17.840±200 bp; al tetto giacciono sedimenti fluvioglaciali trasportati dall’acqua di fusione di un piccolo apparato dell’ultimo massimo glaciale presente sul versante occidentale del m. camicia (giraudi & frezzotti, 1997). nella porzione sommitale della serie compare una fessura parzialmente riempita da carboni e ceneri, formatasi per scivolamento gravitativo di un blocco di sedimenti nel corso di una notevole fase di incisione che ha interessato il conoide. i carboni, datati con il metodo del 14c (giraudi,1999), hanno fornito una data di 5720±120 bp (6840÷6280 cal bp: calibrazione due sigma, come tutte le date successive). i conoidi della ii, iii, iv e v fase sono incassati rispettivamente di 2-4 m, 12, 14 e 15 m rispetto alla superficie della i fase. la destabilizzazione della parte sommitale della successione sedimentaria deve essere avvenuta mentre era in corso un’erosione successiva alla superficie del conoide della ii fase. la sedimentazione della iia fase del conoide è quindi precedente alla data di 5720±120 bp (6840÷6280 cal bp) mentre la sedimentazione dei conoidi delle fasi successive deve essere più recente. 22..22.. llee aalllluuvviioonnii ddii ffoonnttee ddeellllaa mmaacciinnaa presso fonte della macina (2b in fig. 1) affiora una serie di sedimenti alluvionali che formano tre distinti terrazzi. il primo terrazzo è formato (fig. 2b) da una serie di alluvioni prevalentemente ghiaioso sabbiose, nelle quali si intercalano suoli e livelli di alluvioni sabbiose limose, potenti circa 10 m; il tetto della serie è formato da sedimenti alluvionali, eteropici con i depositi fluvioglaciali che formano il conoide della i fase di valle fornaca precedentemente descritto; le alluvioni coprono un paleosuolo datato 21,450±250 bp (giraudi & frezzotti, 1997); al di sotto del paleosuolo i sedimenti si presentano con vario grado di cementazione e affiorano in banchi compatti. il secondo terrazzo, incassato di circa 8-10 m nel precedente, è formato da un deposito alluvionale ghiaioso-sabbioso alla base e sabbioso al tetto; tra le sabbie è intercalato un paleosuolo organico datato 5420±80 bp (bo-253; 6400÷5950 cal bp). il terzo terrazzo, incassato di circa 1 m nel precedente e sospeso di circa 1,5 m sul fondovalle attuale, è costituito prevalentemente da sabbie limose e limi e contiene, intercalato, un paleosuolo poco sviluppato. 22..33.. llee aalllluuvviioonnii ddii ppiiaannoo ddeellll’’oossppeeddaallee nella zona di piano dell’ospedale, ai margini della depressione di prati di cretarola ove sono presenti gli 199i depositi alluvionali olocenici di ... f ig .1 – c ar ta g eo lo gi ca s ch em at ic a di c am po im pe ra to re e d el le a re e ci rc os ta nt i le ge nd a: 1 se di m en ti qu at er na ri; 2 se di m en ti te rr ig en i c en oz oi ci ; 3 ro cc e ca rb on at ic he m es oce no zo ic he ; 4 ci rc hi g la ci al i; 5 m or en e fr on ta li de ll’ u lti m o m as si m o g la ci al e; 6 m or en e st ad ia li; 7 g hi ac ci ai o de l c al de ro ne ; 8 in gh io tti to i c ar si ci ; 9 sp ar tia cq ue p rin ci pa li; 1 0 u bi ca zi on i d el le s ez io ni r ap pr es en ta te n el le f ig . 2 e 3 . g eo lo gi ca l s ke tc h m ap o f c am po im pe ra to re a nd n ei gh bo ur in g ar ea s. le ge nd : 1 q ua te rn ar y se di m en ts ; 2 c en oz oi c te rr ig en ou s se di m en ts ; 3 m es oc en oz oi c ca rb on at e ro ck s; 4 gl ac ia l c irq ue s; 5 la st g la ci al m ax im um fr on ta l m or ai ne ; 6 st ad ia l m or ai ne s; 7 c al de ro ne g la ci er ; 8 po no rs ( sw al lo w -h ol es ); 9 m ai n di vi de s; 1 0 s ite o f t he s tr at ig ra ph ic s ec tio n re pr es en te d in f ig . 2 a nd 3 . 200 fig. 2 – sezioni stratigrafiche schematiche dei sedimenti alluvionali studiati nella porzione orientale di campo imperatore. legenda fig. 2a: 1sedimenti alluvionali attuali e del conoide della v fase; 2sedimenti alluvionali del conoide della iv fase; 3sedimenti alluvionali del conoide della iii fase; 4sedimenti alluvionali del conoide della ii fase; 5sedimenti fluvioglaciali, 6sedimenti alluvionali; 7paleosuoli. legenda fig. 2b: 1sedimenti alluvionali attuali; 2alluvioni p reva len temen te sabbiose del terrazzo inferiore; 3alluvioni prevalentemente sabbiose del terrazzo intermedio; 4alluvioni ghiaiososabbiose del terrazzo intermedio; 5alluvioni ghiaiose del terrazzo più elevato; 6alluvioni sabbiose-ghiaiose; 7alluvioni sabbioso-limose; 8alluvioni ghiaioso-sabbiose cementate; 9paleosuoli. legenda fig. 2c: 1suolo attuale e paleosuolo intercalato ai sedimenti alluvionali; 2alluvioni limose; 3alluvioni p reva len temen te sabbiose; 4alluvioni sabbiso-ghiaiose. stratigraphic sketches through the alluvial sediments in eastern campo imperatore. legend fig. 2a: 1present and phase v alluvial fan sediments; 2alluvial fan sediments of phase iv; 3alluvial fan sediments of phase iii; 4al luvial fan sediments of phase ii; 5f luvioglacial sediments; 6alluvial sediments; 7palaeosols. legend fig. 2b: 1presentday alluvial sediments; 2alluvial sediments, mainly sandy, forming the lower terrace; 3alluvial sediments, mainly sandy, forming the intermediate terrace; 4gravelly-sandy alluvial sediments; 5gravelly-sandy alluvial sediments forming the higher terrace; 6gravelly-sandy alluvial sediments; 7silty sandy alluvial sediments; 8cemented gravelly-sandy alluvial sediments; 9palaeosols. legend fig. 2c: 1presentday soil and palaeosol interbedded between the alluvial sediments; 2silty alluvial sediments; 3sandy alluvial sediments; 4sandy-gravelly alluvial sediments. c. giraudi 201 inghiottitoi carsici, allo sbocco della valle che raccoglie la maggior parte del drenaggio di campo imperatore (2c in fig. 1), vi sono sedimenti alluvionali che formano un terrazzo sospeso di circa due metri sul fondovalle attuale. tale terrazzo, che corrisponde al più basso di fonte della macina, è costituito prevalentemente da sabbie e sabbie limose, che diventano sabbie ghiaiose verso il tetto (fig.2c). intercalato nella porzione mediobassa delle sabbie vi è un paleosuolo che è stato datato 1450±50 bp (beta-162900; 530÷670 cal ad). 22..44.. llee aalllluuvviioonnii eedd ii ccoonnooiiddii aalllluuvviioonnaallii ddii ffoonnttaarrii nella zona occidentale di campo imperatore, in zona fontari (3a in fig. 1) una serie di piccoli conoidi si sono sviluppati allo sbocco di alcune modeste incisioni che tagliano prevalentemente i depositi del versante meridionale del m. aquila. tra i depositi incisi vi sono cordoni di un antico rock glacier (giraudi & frezzotti, 1997), coperti da sedimenti lacustri ed alluvionali depostisi nella depressione compresa tra i cordoni frontali del rock glacier e la base del versante. i sedimenti lacustri coprono un paleosuolo (giraudi, 1998) datato 3440±60 bp (3770÷3430 cal bp). alle spalle del rock glacier c’è stata quindi sedimentazione alluvionale posteriore a tale data, mentre la fase di incisione di tali sedimenti, che ha dato luogo allo sviluppo dei piccoli conoidi alluvionali posti al piede del versante, appare ancora successiva. 22..55.. iill ccoonnooiiddee ddeell mm.. ffaaeettoo il conoide alimentato dalla valle compresa tra il versante settentrionale del m. faeto ed i l m. brancastello (fig. 1) ha fornito varie indicazioni utili per ricostruire l’evoluzione della sedimentazione alluvionale a campo imperatore. tale conoide, sviluppatosi dopo il ritiro dei ghiacciai sia dal suo bacino di alimentazione che dall’apparato morenico di coppe di santo stefano (giraudi & frezzotti, 1997), ha invaso la vallecola che, tagliando gli apparati morenici dell’ultimo massimo glaciale e delle sue fasi di ritiro, permetteva il drenaggio verso est delle acque della estrema porzione occidentale di campo imperatore (3b in fig. 1; fig. 3b). nelle fasi iniziali, i sedimenti alluvionali hanno prodotto la copertura di un paleosuolo datato 12.100±100 bp (14.410÷13.770 cal bp) ed hanno sbarrato la vallecola; allorché il clima diventò più umido, lo sbarramento provocò la formazione di un lago stretto ed allungato ad ovest del conoide (giraudi, 1998;2001). i sedimenti lacustri basali sono stati datati 6090±70 bp (7190÷6770 cal bp), mentre quelli della parte intermedia sono stati datati 5640±60 bp (6630÷6290 cal bp). in seguito il lago si svuotò a causa dell’erosione della soglia e si produsse un’incisione nei sedimenti lacustri che venne riempita da altri sedimenti alluvionali. a valle della zona ove avvenne lo sbarramento della valle (fig. 3b), vi è un secondo corpo alluvionale che copre un paleosuolo sviluppatosi su una superficie di erosione: il paleosuolo è stato datato 4070±70 bp (beta-168676; 4830÷4410 cal bp). un terzo corpo alluvionale copre un paleosuolo che si sviluppa su una blanda superficie di erosione presente al tetto delle alluvioni precedenti; il paleosuolo è stato datato 2130±50 bp (beta-168677; 2190÷1990 cal bp). nella zona apicale dello stesso conoide (3c in fig. 1), il deposito alluvionale che forma il terrazzo più antico, corrispondente a quello che copre il paleosuolo datato 12.100±100 bp (14.410÷13.770 cal bp), è costituito da ghiaie sabbiose nella parte bassa e da massi e ghiaia in matrice sabbiosa nella parte alta; intercalato ai sedimenti alluvionali è presente un paleosuolo (giraudi & frezzotti, 1997), datato 7060±70 bp (8120÷7910 cal bp). un secondo deposito alluvionale appare incassato nel primo: è costituito da ghiaie e ghiaietto in abbondante matrice sabbiosa e copre un paleosuolo sviluppatosi sulla superficie di erosione che incide i sedimenti alluvionali più antichi. il paleosuolo è stato datato 5200±60 bp (bo-285; 6170÷5750 cal. bp). 22..66.. zzoonnaa aa nnoorrdd--oovveesstt ddeell mm.. ssaann ggrreeggoorriioo ddii ppaaggaanniiccaa in una porzione molto piatta di campo imperatore (3d in fig. 1), alle spalle dei depositi morenici, a nord ovest del monte san gregorio di paganica, è stata rinvenuta una alternanza di sedimenti alluvionali prevalentemente sabbiosi, con intercalazioni ghiaioso-sabbiose al tetto, e paleosuoli (fig. 3d): il primo paleosuolo è datato 1410±40 bp (cal. 580÷689 ad – beta-164916); il secondo, che appoggia su una superficie inclinata, è stato coperto in momenti diversi dai sedimenti alluvionali; le datazioni hanno indicato età di 1140±50 bp (cal. 780÷1000 adbeta-162902) per la parte topograficamente più bassa della sua area di affioramento, e di 720±50 bp (cal. 1230÷1390 ad beta-162901) per quella a quota più elevata; vi è inoltre un ulteriore paleosuolo intercalato alle alluvioni che ha fornito una età di 800±50 bp (cal. 1160÷1290 ad beta-162903); l’ultimo paleosuolo è stato datato 380±40 anni bp (cal. 1440÷1640 ad beta-164915) ed è coperto dalle alluvioni più grossolane presenti nella sezione. dopo la sedimentazione delle alluvioni che coprono il paleosuolo più recente, vi è stata una fase erosiva, la deposizione di un piccolo corpo alluvionale e quindi una nuova fase di incisione ancora in corso. nella stessa zona, ma su un conoide posto poco a nord-ovest, un paleosuolo coperto da depositi alluvionali è stato datato 250±40 anni bp (beta-168678; cal ad 1520÷1800) nel complesso, a campo imperatore sono state individuate varie unità alluvionali oloceniche che danno luogo ad una serie di 5 terrazzi sospesi sul fondovalle attuale (fig. 4) e che trovano riscontro in varie zone appenniniche. il primo terrazzo alluvionale è costituito da alluvioni prevalentemente ghiaioso sabbiose, successive ad un paleosuolo datato 12.100±100 bp (14.410÷13.770 cal bp), e contenenti intercalato un paleosuolo datato 7060±70 bp (8120÷7910 cal bp). al piano aremogna, presso roccaraso (abruzzo), a quote simili a quelle di campo imperatore, frezzotti & giraudi (1989) segnalano la presenza di un sedimento alluvionale databile tra circa 10.000 e 7000 anni fa. il secondo terrazzo alluvionale, incassato nel precedente, è costituito da alluvioni prevalentemente sabbiose o formate da sabbia con ghiaietto, che contengono intercalato un paleosuolo datato rispettivamente 5200±60 bp (6170÷5750 cal. bp) e 5420±80 bp (6400÷5950 cal bp). i depositi alluvionali olocenici di ... 202 c. giraudi al piano aremogna, presso roccaraso (abruzzo), frezzotti & giraudi (1989) segnalano la presenza di un paleosuolo datato 5060±150 bp (6020÷5650 cal bp), intercalato a sedimenti alluvionali. il terzo terrazzo alluvionale è costituito da alluvioni ghiaioso-sabbiose che coprono un paleosuolo datato 4070±70 bp (4830÷4410 cal bp) e che inglobano un paleosuolo datato 2130±50 bp (2190÷1990 cal bp). sulle sponde del lago ballano (appennino reggiano, quota 1550 m s.l.m.m.) ricerche in corso hanno evidenziato la presenza di sedimenti alluvionali che coprono torbe datate 4060±60 anni bp (4810÷4420 cal bp – beta-154565). il quarto terrazzo alluvionale appare costituito da un’alternanza di depositi prevalentemente fini e di suoli intercalati, datati 1410±40 bp (580÷689 ad), 1140±50 bp (780÷1000 ad); 720±50 bp (1230÷1390 ad), 800±50 bp (1160÷1290 ad) e 380±40 anni bp (1440÷1640 ad). nella valle parma di budignana, a quota 1530 m s.l.m.m. presso il lago scuro, ricerche in corso hanno evidenziato che un sedimento alluvionale 203 fig. 4 – schema dei rapporti stratigrafici tra i sedimenti alluvionali olocenici di campo imperatore. stratigraphic sketch through the holocene campo imperatore alluvial sediments. fig. 3 – sezioni geologiche schematiche dei sedimenti alluvionali studiati nella porzione occidentale di campo imperatore. legenda fig. 3a: 1sedimenti alluvionali; 2sedimenti lacustri; 3accumulo di rock glacier; 4substrato carbonatico meso-cenozoico; 5paleosuolo. legenda fig. 3b: 1sedimenti alluvionali sabbioso-limosi; 2sedimenti alluvionali sabbiso-ghiaiosi; 3sedimenti alluvionali ghiaiososabbiosi della terza fase del conoide; 4sedimenti alluvionali ghiaioso-sabbiosi della seconda fase del conoide; 5sedimenti sabbiosi e limosi lacustri; 6 sedimenti alluvionali ghiaioso-sabbiosi della prima fase del conoide; 7sedimenti ghiaioso-sabbiosi fluvioglaciali; 8depositi morenici; 9paleosuoli. legenda fig. 3c; 1sedimenti dell’alveo attuale; 2sedimenti alluvionali sabbioso-ghiaiosi; 3ghiaie sabbiose con blocchi; 4ghiaie sabbiose della prima fase del conoide; 5-substrato carbonatico meso-cenozoico; 6paleosuoli. legenda fig. 3d: 1suolo attuale e paleosuoli intercalati; 2sedimenti alluvionali prevalentemente sabbioso-limosi; 3sedimenti alluvionali sabbiosi; 4sedimenti alluvionali sabbioso-ghiaiosi. stratigraphic sketch through the alluvial sediments in western campo imperatore. legend fig. 3a: 1alluvial sediments; 2lacustrine sediments; 3debris forming the body of the rock glacier; 4bedrock; 5palaeosol. legend fig. 3b : 1silty-sandy alluvial sediments; 2sandy-gravelly alluvial sediments; 3gravelly-sandy alluvial fan sediments of phase iii ; 4gravelly-sandy alluvial fan sediments of phase ii ; 5sandy-silty lacustrine sediments; 6gravelly-sandy alluvial fan sediments of phase i; 7gravelly-sandy fluvioglacial sediments; 8till; 9palaeosols. legend fig. 3c: 1alluvial sediments in presentday stream bed; 2sandy-gravelly alluvial sediments; 3sandy gravels with boulders; 4gravelly sandy alluvial fan sediments of the phase i; 5bedrock; 6palaeosols, legend fig. 3d: 1presentday soil and palaeosols interbedded between the alluvial sediments; 2silty-sandy alluvial sediments; 3sandy alluvial sediments; 4sandy-gravelly alluvial sediments. ➧ contiene un tronco fluitato datato 1310±60 bp (640÷870 cal. ad – beta-154566) l’ultimo terrazzo appare in via di colonizzazione ad opera della vegetazione e, come dimostra lo sviluppo successivo ad eventi deposizionali, erosivi e pedogenetici più recenti dei secoli xv-xvii, il suo modellamento deve essere avvenuto in tempi molto recenti. 33.. ddiissccuussssiioonnee i depositi alluvionali di campo imperatore si sono sedimentati in vari periodi dell’olocene, ma la loro granulometria indica che l’energia dei corsi d’acqua che li ha depositi era molto diversa. nel corso della sedimentazione del corpo alluvionale che costituisce il primo terrazzo, avvenuta in un periodo compreso tra 12.100±100 bp (14.410÷13.770 cal bp) e 5420±80 bp (6400÷5950 cal bp) la forte energia dei corsi d’acqua evidenzia una situazione di resistasia, e quindi di instabilità dei versanti, anche se attorno a 7060±70 bp (8120÷7910 cal bp) i depositi alluvionali olocenici di ... deve esserci stato un episodio di durata non ben definibile di biostasia, durante il quale, grazie alla stabilità morfologica, si è sviluppato un suolo. nel corso della sedimentazione del corpo alluvionale che forma il secondo terrazzo, datato tra 7060±70 bp (8120÷7910 cal bp) e 4070±70 bp (4830÷4410 cal bp), la granulometria dei sedimenti, piuttosto fine, sembra testimoniare una fase di limitata resistasia; lo sviluppo di suoli datati attorno a 5200±60 bp (6170÷5750 cal. bp) e 5420±80 bp (6400÷5950 cal bp) testimoniano il verificarsi di un periodo di biostasia e di stabilità morfologica. tra la sedimentazione di questo corpo alluvionale ed i l successivo, attorno a circa 4070±70 bp (4830÷4410 cal bp) deve essersi verificata una fase di biostasia che ha prodotto lo sviluppo del suolo di tale età. nel corso della sedimentazione del corpo alluvionale che forma il terzo terrazzo, costituito da sedimenti piuttosto grossolani, datato tra 4070±70 bp (4830÷4410 cal bp) e un periodo successivo a 2130±50 bp (2190÷1990 cal bp) e precedente a 1410±40 bp (580÷689 ad), deve essersi verificata una fase di resistasia e di instabilità dei versanti, interrotta da una breve fase di biostasia attorno a 2130±50 bp (2190÷1990 cal bp), allorché si sviluppò un suolo. la sedimentazione delle alluvioni che formano il quarto terrazzo deve essere avvenuta sotto condizioni ambientali variabili caratterizzate da moderata resistasia, data la granulometria prevalentemente fine dei sedimenti, e da vari periodi di biostasia nel corso dei quali si sviluppavano i suoli. solo dopo lo sviluppo del suolo datato 1440÷1640 ad aumentò l’energia dei corsi d’acqua e quindi si instaurò una fase di resistasia più marcata. poiché le fasi alluvionali registrate a campo imperatore sono state anche riconosciute in altre località dell’appennino settentrionale e centrale, a quote simili a quelle dell’area oggetto del presente studio, si assume che siano state innescate da variazioni ambientali risentite almeno nell’italia peninsulare. le fasi alluvionali descritte sono ben correlabili con le espansioni del ghiacciaio del calderone posto sul versante nord-orientale del corno grande (fig. 1), sul gran sasso, segnalate da giraudi (2000; 2002). il ghiacciaio si riformò e si espanse dopo lo sviluppo di un suolo datato 3895±65 anni bp (4520÷4110 cal. bp), un momento molto vicino all’inizio della sedimentazione delle alluvioni che formano il terzo terrazzo. una ulteriore espansione glaciale provocò la copertura di un suolo datato 1450±40 bp (cal. 540÷660 ad); è quindi contemporanea alla copertura di suoli ad opera delle alluvioni basali del complesso di sedimenti che forma il quarto terrazzo. una nuova espansione glaciale ebbe luogo tra 1450±40 bp (cal. 540÷660 ad) e 670±40 anni bp ( cal. 1270÷1400 ad), contemporaneamente alla sedimentazione della porzione intermedia dei sedimenti che formano il quarto terrazzo. il ghiacciaio del calderone raggiunse la sua massima espansione tardo-olocenica nel corso di un’avanzata successiva a 670±40 anni bp (cal. 1270÷1400 ad), quindi nel corso della cosiddetta piccola età glaciale, quando si formava la porzione sommitale, più grossolana, dei sedimenti alluvionali del quarto terrazzo di campo imperatore. oltre alle correlazioni con le fasi di avanzata del ghiacciaio del calderone, possiamo osservare altri elementi di correlazione tra la sedimentazione alluvionale a campo imperatore e le fasi di avanzata glaciale registrate in altre aree. la fase di sedimentazione alluvionale che forma il secondo terrazzo, successiva ai suoli datati attorno a 5000 anni bp (date non calibrate), coincide con l’ inizio della cosiddetta neoglaciazione (orombelli & ravazzi, 1996). la copertura del paleosuolo, datato 780÷1000 ad, ad opera del complesso di sedimenti alluvionali che costituiscono il quarto terrazzo, coincide con una fase di avanzata glaciale registrata sulle alpi. infatti le morene del ghiacciaio della brenva (m. bianco) in fase di avanzata hanno coperto un albero datato 1170±75 14c years bp (760÷980 cal. ad: orombelli & porter, 1982), mentre le morene di una fase di avanzata del ghiacciaio del lys, sul massiccio del m. rosa, coprono un paleosuolo datato 1185±80 14c years bp (734÷980 cal. ad; strumia, 1997). 44.. ccoonncclluussiioonnii il rilevamento geologico e geomorfologico di dettaglio eseguito sui sedimenti e sui terrazzi alluvionali di campo imperatore ha permesso di distinguere varie fasi di sedimentazione oloceniche. la scansione cronologica dell’attività alluvionale, ottenuta per mezzo di datazioni radiocarbonio su paleosuoli e sedimenti lacustri, dimostra come il trasporto solido nei corsi d’acqua sia avvenuto, seppure con diversa energia e con brevi fasi di interruzione, lungo gran parte dell’olocene. appare poi evidente la correlazione tra fasi di sedimentazione alluvionale a campo imperatore e quelle riconosciute in altre località dell’appennino centrale e settentrionale, ma anche con le fasi di espansione del ghiacciaio del calderone e di alcuni ghiacciai alpini. le fasi alluvionali di campo imperatore sono quindi strettamente legate all’impatto sull’ambiente prodotto da variazioni climatiche risentite sia in area mediterranea che alpina, evidenziate anche da proxy-data, quali i ghiacciai, che non possono essere influenzati dall’intervento dell’uomo. anche se si hanno indizi di incendi preistorici di origine antropica (giraudi,1999), i dati sembrano dimostrare che l’impatto umano non è stato in grado di produrre una destabilizzazione dei versanti e di dare luogo a fasi di sedimentazione alluvionale indipendenti da quelle prodotte dalle variazioni climatiche. la presenza di molti ed estesi corpi sedimentari di origine alluvionale appare strettamente legata alla esistenza di vaste fasce di cataclasiti presso la base del versante che borda la porzione settentrionale di campo imperatore; i molti gullies incisi in questa zona si sono stabilizzati solo rare volte, forse in coincidenza con le maggiori fasi di stabilità morfologica, mentre per gran parte dell’olocene l’erosione è stata attiva ed ha fornito materiale clastico per il trasporto solido nell’alveo dei corsi d’acqua. il notevole dettaglio di fasi di sedimentazione e di pedogenesi registrate nei sedimenti che formano il quar204 c. giraudi to terrazzo (di età storica) appare sostanzialmente legato al fatto che il sito studiato si trova in un’area molto piatta: in tali zone i corsi d’acqua perdono energia, la sedimentazione è prevalentemente fine e le superfici di erosione sono assai blande. in alcune aree pianeggianti della porzione occidentale di campo imperatore si verificano quindi le condizioni adatte alla preservazione dei sedimenti deposti dalle fasi alluvionali secondarie che, nel loro complesso, hanno formato il quarto terrazzo. un dettaglio simile non è stato però trovato nei depositi alluvionali più antichi, rilevati in zone ove i corsi d’acqua avevano maggiore energia e dove la sedimentazione era più grossolana e le fasi di erosione assai più intense. rriinnggrraazziiaammeennttii il presente lavoro è stato condotto coi contributi finanziari del ministero per l’ambiente nell’ambito dell ’accordo di programma enea – ministero dell’ambiente, progetto 2,4 – variazioni climatiche, e del parco nazionale gran sasso-monti della laga. rriiffeerriimmeennttii bbiibblliiooggrraaffiiccii demangeot j. (1965) – géomorphologie des abruzzes adriatiques. mem. et doc. , c.n.r.s., 403 pp. frezzotti m. & giraudi c. (1989) evoluzione geologica tardo-pleistocenica ed olocenica del piano di aremogna (roccaraso abruzzo): implicazioni climatiche e tettoniche. mem. soc. geol. it., 4422, 519. frezzotti m. & giraudi c. (1990) – sedimenti eolici tardopleistocenici ed olocenici nell ’appennino centrale. mem.soc.geol.it., 4455, 883-886. ghisetti f. & vezzani l. (1986) – carta geologica del gran sasso d’italia (da vado di corno a passo delle capannelle). s.e.l.c.a., firenze. ghisetti f. & vezzani l. (1990) – carta geologica del gruppo del m. siella-m. camicia-m. prenam. brancastello (gran sasso d’italia, abruzzo). caratteri stratigrafici e strutturali del settore orientale della catena del gran sasso. s.e.l.c.a., firenze. giraudi c. (1994) elementi di geologia del quaternario della piana di campo imperatore (massiccio del gran sasso italia centrale). in atti tic. sc. terra (serie speciale), 22, 137-143. giraudi c. (1998) i laghi effimeri tardopleistocenici ed olocenici di campo imperatore e del massiccio del gran sasso d'italia (abruzzo italia centrale). il quaternario, 1111 (2), 217-225. giraudi c. (1999) incendi di età pleistocenica superiore e olocenica sulle montagne dell'appennino centrale. il quaternario, 122(2), 143-146. giraudi c. (2000) le oscillazioni oloceniche del ghiacciaio del calderone, gran sasso d'italia (abruzzo italia). il quaternario, 1133(1/2), 31-38. giraudi c. (2001) the late pleistocene and holocene temporary lakes in the abruzzo parks and the central apennine. in visconti g., beniston m., iannorelli e. & barba d. eds: global change and protected areas. advances in global changes research, 99, 445-458. giraudi c. (2002) – le oscillazioni del ghiacciaio del calderone (gran sasso d’italia, abruzzo – italia centrale) e le variazioni climatiche degli ultimi 3000 anni. il quaternario, 1155(2), 145-150. giraudi c. & frezzotti m. (1997) late pleistocene glacial events in the central apennine, italy. quaternary research, 4488 (3),280-290. orombelli g. & porter s.c. (1982) late holocene fluctuations of brenva glacier. geogr. fis. dinam. quat. 55,13-37. orombelli g. & ravazzi c. (1996) – the late glacial and early holocene chronology and paleoclimate. il quaternario, 9(2), 439-444. servizio geologico d’italia (1963) carta geologica d’italia a scala 1:100.000, f. 140, teramo. ii edizione. strumia g. (1997) oscillazioni glaciali precedenti la piccola età glaciale documentate da un suolo sepolto in una morena del ghiacciaio del lys. il quaternario, 1100(2), 153-158. 205 ms. ricevuto il 13 maggio 2003 testo definitivo ricevuto il 10 giugno 2003 ms. received: maj 13, 2003 final text received: june 10, 2003 i depositi alluvionali olocenici di ... imp. messina & sseeddiimmeennttii ee ffoorrmmee qquuaatteerrnnaarrii nneellll’’aallttaa vvaallllee ddeellll’’aatteerrnnoo ((ll’’aaqquuiillaa)) ppaaoolloo mmeessssiinnaa11,, ccaarrlloo bboossii11 && mmaarrccoo mmoorroo22 1istituto di geologia ambientale e geoingegneria del cnr via del fosso del cavaliere, 100 00133 roma e-mail: ; p.messina@igag.cnr.it; c.bosi@igag.cnr.it 2istituto nazionale di geofisica e vulcanologia via di vigna murata, 605 00143 roma e-mail: moro@ingv.it riassunto l’area studiata si sviluppa lungo la valle del fiume aterno e, nei pressi di arischia, è caratterizzata dalla presenza di un’ampia conca che ospita significativi spessori di depositi continentali quaternari. in particolare, nell’area compresa tra s. giovanni ed il versante sudoccidentale del m. pettino, è stata riconosciuta una complessa successione di eventi deposizionali ed erosivi che sono stati sintetizzati in uno schema allo-morfosequenziale ottenuto dall’integrazione di unità allostratigrafiche e unità morfosequenziali cronologicamente ordinate. queste ultime corrispondono a superfici relitte, sia di erosione che di accumulo, variamente disposte alla sommità dei rilievi e lungo i versanti della valle e scolpite sia nel substrato marino che nelle unità continentali. in totale sono state riconosciute 19 unità morfosequenziali e 11 unità allostratigrafiche dalla cui integrazione sono state ottenute 8 unità allo-morfosequenziali. gli elementi cronologici di tipo strumentale (analisi paleomagnetiche e determinazioni radiometriche) disponibili per sei unità allostratigrafiche, nonché alcune indicazioni ottenute da tentativi di correlazione con unità presenti in altri bacini della regione, hanno permesso di formulare un’ipotesi di inquadramento cronologico (dal pliocene al pleistocene superiore) per alcune delle unità riconosciute. l’analisi di questa successione ha permesso di delineare una situazione caratterizzata dal progressivo incassamento di forme e litosomi che viene a corrispondere alle varie fasi del progressivo approfondimento del reticolo idrografico. questo tipo di evoluzione geologica risulta essere condizionata in modo determinante dall’attività, anche recente, di due strutture tettoniche riconoscibili alla base dei versanti sud-occidentali rispettivamente di m. marine e di m. pettino. abstract the investigated area is located in the aterno valley river, abruzzi apennines. the sector of arischia is represented by a wide valley with numerous outcrops of continental quaternary deposits. in particular, in the area between s. giovanni and the south western side of mt. pettino, a complex succession of depositional and erosive events has been defined. these events have been summarised in an allo-morphosequential scheme obtained by the integration of allostratigraphic units and morphosequential units, which have been put in chronological order. the latter units correspond to relict surfaces (due to erosion or accumulation), variously located at the summit of the reliefs or along the flanks of the valley, sculptured in both marine substrata and in the continental units. in the surveyed area a total of 8 allo-morphosequential units have been defined through the integration of 19 morphosequential units and 11 allostratigraphic units. the chronological data (magnetic polarity and radiocarbon data), available for 6 allostratigraphic units, as well as indications derived from of correlations with units of adjacent intermountain basins, allowed to make a hypothesis about a chronological framework (between the pliocene and the late pleistocene) for some of the defined units. the analysis of this succession led to defined a geological evolution represented by the progressive embedding of erosive and depositional landforms and lithosomes, representing the progressive deepening phases of the hydrographic network. this geological evolution has been conditioned by the activity, even recent, of two faults affecting the bottom of the south western slopes of mt. marine and mt. pettino, respectively. parole chiave: quaternario, conche intermontane, appennino centrale. keywords: quaternary, intramountain basin, central apennines il quaternario italian journal of quaternary sciences 1166(2), 2003, 231-239 11.. pprreemmeessssaa la zona alla quale si riferisce questa nota è rappresentata dal tratto della valle dell’aterno compreso fra la stretta di s. giovanni ed il bordo settentrionale della conca aquilana, ad ovest della catena del gran sasso. essa è costituita da un’ampia conca a fondo pianeggiante, sviluppata lungo il fondovalle del fiume aterno e delimitata dal versante sw del m. marine e dalle propaggini ne del gruppo del m. giano. la conformazione e l’evoluzione geologica della conca è strettamente condizionata dall’attività delle faglie che hanno originato, come espressione morfologica, i versanti sud-occidentali del m. marine e del m. pettino (fig. 1). l’assetto generale dell’area, molto simile a quelle di molte depressioni intermontane abruzzesi, corrisponde ad un complicato insieme di superfici di erosione e di accumulo, in vario rapporto con litosomi quaternari costituiti da sedimenti fluviali e lacustri e da depositi di versante. questi poggiano in discordanza su sequenze carbonatiche e su depositi terrigeni miocenici, affioranti solo nella porzione settentrionale della valle dell’aterno. i dati geologici, geomorfologici e tettonici disponibili nella bibliografia geologica sono quelli riportati in bosi (1975), blumetti (1995), bagnaia et al. (1996), blumetti et. al. (1996), basili et al. (1997), basili et al. (1999), messina et al. (2001) e moro et al., (2002). l’area studiata è stata recentemente oggetto di un rilevamento eseguito nell’ambito di un progetto per la 232 p. messina, c. bosi & m. moro redazione di carte prototipali finanziato dal servizio geologico nazionale e dal cnr. i risultati di interesse cartografico sono riportati in bosi et al. (2003); quelli di più specifico interesse stratigrafico-evolutivo sono contenuti nei paragrafi che seguono. 22.. aassppeettttii mmeettooddoollooggiiccii i sedimenti quaternari presenti nella zona studiata, come del resto nella maggior parte delle conche intermontane dell’appennino laziale-abruzzese, hanno caratteristiche (uniformità delle litofacies, scarsità degli elementi di datazione, difficoltà di correlazioni, ecc.) che ostacolano una dettagliata ricostruzione dell’evoluzione geologica nei suoi diversi aspetti (stratigrafico, geomorfologico, tettonico). proseguendo in una prospettiva di ricerca già seguita da tempo (bertini e bosi, 1993) lo studio stratigrafico è stato quindi integrato dall’esame della successione delle superfici relitte, rappresentate essenzialmente da spianate di accumulo e da superfici di erosione. le prime sono quelle sviluppate a tetto di litosomi di origine genericamente fluviale. le seconde sono rappresentate da superfici, pianeggianti o comunque a bassa energia di rilievo, scolpite nelle rocce del substrato o più raramente in terreni quaternari; esse sono probabilmente legate a fenomeni di erosione laterale realizzatisi durante stazionamenti di antichi livelli di base locali (bosi et al., 1996). rinviando per maggiori dettagli a bosi et al. (2003) ci si limita in queste sede a ricordare che l’insieme delle superfici identificate è stato utilizzato integrandolo con gli elementi di ordine stratigrafico mediante le operazioni seguenti: a) equiparazione delle forme fossili (unità morfologiche), assunte come indicatori di eventi erosivi o deposizionali, al le unità stratigrafiche, assunte come prodotti di specifici eventi deposizionali (bosi et al., 2003 e relativa bibliografia); b) definizione di una corrispondenza cronologicamente ordinata fra la “successione morfosequenziale”, costituita da unità morfologiche, e la successione stratigrafica, costituita in questo caso da unità allostratigrafiche; c) definizione di “unità allo-morfosequenziali” (uam) sulla base dell’integrazione di unità morfosequenziali (um) con unità allostratigrafiche (ua); d) collocazione di queste unità in una “successione allo-morfosequenziale” unitaria. in questa successione (fig. 2) sono state collocate anche superfici di erosione scolpite nel substrato mesocenozoico, prive di rapporti diretti con unità stratigrafiche quaternarie. fig. 1 ubicazione dell’area di studio. 1, faglia diretta (a) e suo probabile prolungamento (b); i trattini indicano il lato ribassato. location of the investigated area. 1, normal fault (a) and possible prolongation (b); hatching on downthrown side. 33.. llaa ssuucccceessssiioonnee aalllloo--mmoorrffoosseeqquueenn-zziiaallee una sintesi stratigrafico-geomorfologica dell’area esaminata può essere delineata a partire dai lembi di antichi paesaggi probabilmente pliocenici (galadini et al., 2003 e relativa bibliografia) conservati alla sommità dei rilievi ed in particolare nella zona di m. marine. incassati in essi sono stati riconosciuti alcuni lembi di spianate erosive, molto rimodellati, presenti sulla destra dell'aterno nella zona di cagnano amiterno (a-f di fig. 2). segue poi una complicata successione di superfici di erosione e di litosomi continentali (talora con le relative superfici di accumulo) progressivamente incassati a costituire una successione terrazzata che differisce da quelle usualmente considerate per il fatto che comprende anche le superfici di erosione scolpite nel substrato carbonatico, del tutto equiparabili alle usuali superfici terrazzate. applicando a questa successione il procedimento sopra indicato sono state definite 19 unità morfosequenziali e 11 unità allostratigrafiche, dalla cui integrazione sono state ottenute le 8 unità allo-morfosequenziali che compaiono nella schema di fig. 2. come risulta da questo schema, tutte le unità riconosciute, indipendentemente dal fatto che si tratti di unità morfologiche o stratigrafiche, sono state numerate progressivamente, dalla più recente (sedimenti alluvionali dell’attuale fondovalle, 1) alla più antica (superficie di erosione a letto dei sedimenti continentali più antichi, 271). ogni unità allo-morfosequenziale è stata poi indicata con due numeri che rappresentano l’elemento più antico e quello più recente che costituiscono l’unità stessa. 233sedimenti e forme quaternari ... le caratteristiche principali delle unità istituite possono essere sintetizzate come segue. uam 26/27 l’unità allostratigrafica 26 è costituita da conglomerati ad elementi carbonatici poco elaborati e da alternanze di livelli ghiaiosi con ciottoli arenacei e calcarei molto elaborati e livelli sabbioso-limosi. lo spessore minimo dell’unità è di circa 60 metri. l'intera successione presenta giaciture differenti da quelle primarie, con inclinazioni degli strati che raggiungano in alcuni casi circa 20°, verso nord-est (fig. 3). questa unità, stratigraficamente più antica dell’ua 21 (caratterizzata da polarità magnetica inversa, v. sotto), presenta polarità normale (messina et al., 2001). essa risulta essere quindi verosimilmente più antica di 1,770 ma (l’età dei limiti dei croni è riferita a cande e kent, 1995) e riferibile dunque ad un generico pliocene. um 23-24-25 sono costituite da lembi di spianate di erosione rimodellate, scolpite nel substrato e sviluppate a quote comprese tra 750 e 850 m s.l.m. (fig. 4). uam 21/22 l’ua 21 è costituita da ghiaie fluviali, talora sabbioso-limose, con elementi generalmente ben arrotondati (dimensioni variabili fino a 20 centimetri), localmente con intercalazioni sabbioso–limose con livelli ossidati. la stratificazione immerge nel quadrante di sw, con inclinazioni che raggiungono i 10°. l’embricatura dei ciottoli indica una direzione di trasporto da nw a se, mediamente parallela al corso attuale dell’aterno. lo spessore minimo dell’unità è di circa 30 metri. la parte alta dell’unità è troncata da una superficie di erosione su cui poggiano ghiaie fluviali, di pochi metri di spessore e con giaciture generalmente suborizzontali, appartenenti a successivi cicli sedimentari, non definibili nel dettaglio. come già accennato precedentemente, fig. 2 schema dei rapporti morfologico-stratigrafici. morpho-stratigraphic framework. 1 ad ogni numero è stata associata una sigla che ne chiarisce la natura (se=superficie di erosione; sa=superficie di accumulo; li= litosoma). 234 questa unità presenta polarità magnetica inversa ed è quindi probabilmente riferibile al pleistocene inferiore (croni inversi c1r e c1r.1r, età tra 0,780 e 1,770 ma secondo cande e kent, 1995). uam 18/20 l’unità allostratigrafica 19 è costituita da limi sabbioso-argillosi ben stratificati, a luoghi laminati, a giacitura generalmente suborizzontale. questi strati (spessore affiorante 15 m circa) rappresentano un deposito di fine ciclo fluviale passante verso l’alto ad ambiente lacustre. questa unità, più recente dell’ua 21, è caratterizzata da polarità magnetica normale; è possibile assumere che si sia deposta durante il crono normale brunhes e che sia quindi più recente di 0,780 ma. l’unità è delimitata a tetto dalla superficie di accumulo (um 18) ben conservata e riconoscibile a nw di barete a quota 780-800. fig. 3 ghiaie fluviali basculate dell’unità allostratigrafica 26. tilted fluvial gravels related to the allostratigraphic unit 26. fig. 4 unità morfosequenziale um25 scolpita nel substrato carbonatico e sospesa sui depositi continentali nei pressi di arischia. morphosequential unit um25 carved into the carbonate bedrock and suspended over the continental deposits in the area of arischia. p. messina, c. bosi & m. moro 235 um 17 corrisponde ad alcuni lembi di superfici di erosione a nord di s. vittorino, a quota 710-800 m, probabilmente riconducibili ad un episodio di spianamento unitario, che ha interessato in modo indifferenziato sia il substrato calcareo che le unità allostratigrafiche 26 e 21 (figg. 5 e 6). uam 14/16 l’unità allostratigrafica 15 è costituita da 10 metri circa di sabbie fini limose con rari ciottoli calcarei poco arrotondati, deposte in un ambiente di tipo fluviale di bassa energia. anche se gli affioramenti sono limitati per numero e per dimensione, in questa unità, come nelle precedenti, non sono stati osservati minerali di orifig. 5 ghiaie fluviali e livelli di sabbie e limi dell’unità allostratigrafica 21. alla sommità dei depositi è visibile l’unità morfosequenziale 17 (vedi anche figura 6). fluvial gravels with sandy and silty levels related to the allostratigraphic unit 21. see the morphosequential unit 17 on the top of the deposits (see also figure 6). fig. 6 unità morfosequenziale 17. sullo sfondo è visibile la scarpata di faglia di m. marine. morphosequential unit 17. see the mt. marine fault scarp in the background. sedimenti e forme quaternari ... 236 gine vulcanica. per questo motivo potrebbe collocarsi nella parte bassa del pleistocene medio (fornaseri, 1985; narcisi e sposato, 1989). l’unità è delimitata a tetto dalla corrispondente superficie di accumulo (um14) conservata in lembi rimodellati nella zona di cavallari. lateralmente questa superficie corrisponde ad una spianata di erosione che interessa sia il substrato calcareo che l’ua 21, ad una quota compresa tra 690 e 720 m circa. uam 11/13 l’ua 12 è costituita da livelli suborizzontali di ghiaie fluviali, variamente sabbiose, con elementi molto arrotondati, e da lenti di sabbie che contengono abbondante materiale di origine vulcanica (piccole scorie, pirosseni, biotite, ecc.). lo spessore affiorante dell’unità è di circa 25 metri. questi strati rappresentano la prima unità che è caratterizzata da significativi apporti di minerali vulcanici. l’unità è delimitata a tetto dalla relativa superficie di accumulo (um 11) conservata in lembi a quote 670715, nella zona compresa tra prato lagone e prato dell’agora. um 10 questa unità è costituita da lembi di una spianata di erosione sviluppati a quote 665-675 e scolpiti nell’ua 12 nell’area compresa tra c.le visconti e pratiglio. uam 7/9 l’unità allostratigrafica 8 è costituita da pochi metri di ghiaie sabbioso-limose, di ambiente fluviale ed è delimitata a tetto dalla relativa superficie di accumulo (um 7) conservata in lembi a quote 670-680. uam 4/6 l’unità allostratigrafica 5 è rappresentata da pochi metri di spessore di strati limoso-sabbiosi con livelli a piccoli clasti sub-arrotondati ed è delimitata a tetto da una superficie di accumulo (um 4), ben riconoscibile nella zona di scentella. lateralmente questa superficie corrisponde ad una spianata di erosione che interessa le unità più antiche. uam 1/3 l’unità allostratigrafica 2 è rappresentata da sedimenti fluviali sabbioso-ghiaiosi del fondovalle attuale e da coltri colluviali che ad esso si raccordano, nonché da depositi di versante e da depositi di conoide. essa è delimitata a tetto dalla superficie di accumulo (um 1), che corrisponde all’attuale fondovalle del fiume aterno. nell’ambito dell’area esaminata sono stati riconosciuti anche strati riconducibili a due unità stratigrafiche (“brecce di s. marco” e “brecce di s. antonio) non chiaramente collocabili nell’ambito della successione descritta (fig. 2). brecce di s. marco. si tratta di brecce cementate ben stratificate (fig. 7) costituite da clasti calcarei a spigoli vivi immersi in una matrice calcarea spesso di colore rosa. lo spessore massimo è di circa 50 metri. analisi paleomagnetiche eseguite su alcuni campioni (messina et al., 2001) hanno evidenziato una polarità magnetica inversa, inducendo ad ipotizzare un’età pleistocenica inferiore (croni inversi c1r e c1r.1r, età tra 0,780 e 1,770 ma secondo cande e kent, 1995). brecce di s. antonio si tratta di orizzonti di brecce di pochi metri di spessore costituiti da clasti carbonatici a spigoli vivi in matrice generalmente terrosa di colore bruno. la stratificazione è generalmente a franapoggio e accompagna l’andamento del versante dei r i l ievi carbonatici. determinazioni radiometriche (c14) eseguite su alcuni livelli contenenti materiale organico intercalati alle “brecce di s. antonio” forniscono un’età variabile tra 31.710±760 e 23.330±300 anni b.p. (galadini e galli, 2000). quanto fino a qui descritto non comprende tutti i depositi riconosciuti. esistono infatti alcuni depositi ai quali non è stato possibile, data la scarsità e la dispersione areale dei modesti affioramenti osservati, attribuire una precisa collocazione stratigrafica. si tratta frequentemente di ghiaie, probabilmente fluviali, con clasti variamente arrotondati, alle quali si intercalano talora orizzonti a clasti con spigoli vivi e livelli sabbiosi. frequenti nei depositi di questo tipo i livelli di sedimenti di suolo, limoso-sabbiosi. sul versante sinistro della valle, sono state inoltre osservate successioni di strati sabbiosi, con intercalazioni di clasti a spigoli vivi, passanti talora a sabbie medio-fini, laminate o, più raramente massive. caratteristica di queste successioni sono le evidenti deformazioni con acquisizione di inclinazione dell’ordine anche della decina di gradi. non si può escludere che queste successioni siano riferibili a fasi deposizionali distinte, che potrebbero portare alla definizione di più unità allostratigrafiche. ad una di queste unità sono da riferire i livelli datati 29.690±1.100 da blumetti (1995). del tutto sporadici sono piccoli lembi di limi calcarei biancastri di origine lacustre. tutti i sedimenti citati affiorano al disotto di coperture detritiche, verosimilmente riferibili ad eventi deposizionali nettamente distinti. data l’impossibilità di chiarire, in modo compatibile con il dettaglio adottato per le altre unità che sono state sopra definite, le caratteristiche stratigrafiche di queste successioni, esse sono state comprese nell’“allogruppo di arischia”. 44.. ccrroonnoollooggiiaa ee ccoorrrreellaazziioonnii in nessuna delle unità stratigrafiche riconosciute sono state rinvenute faune o flore di interesse cronologico. gli unici riferimenti disponibili al riguardo sono quindi quelli strumentali, già indicati nella descrizione delle singole unità. essi possono essere così sintetizzati: ua 26 pliocene; ua 21 e brecce di s. marco pleistocene inferiore; ua 19, ua 15 pleistocene medio; brecce di s. antonio pleistocene superiore. altre indicazioni di significato cronologico possono essere ottenute da tentativi di correlazione con altre unità riconosciute nella regione. l’unità allostratigrafia 26 sembra ragionevolmente p. messina, c. bosi & m. moro correlabile con le “sabbie di piagge” della valle del salto (bertini e bosi, 1976), con la formazione di aielli della conca del fucino (bosi et al., 1995), con la formazione di s. croce nella valle del turano e con la formazione di pianola (bosi et al., 2003). questa correlabilità discende da forti analogie stratigrafiche, geomorfologiche e tettoniche, consistenti nel fatto che tutte queste unità hanno in comune le seguenti caratteristiche: rappresentano il primo importante episodio conservato di sedimentazione continentale che ha interessato le diverse zone; sono le più antiche fra quelle incassate nel paleopaesaggio riferito al pliocene; sono tutte interessate da vistose deformazioni. l’unità allostratigrafica 21 presenta forti spessori e mostra spiccate analogie litologiche e strutturali con le formazioni di cupoli nella conca del fucino (bosi et al., 1995), di pescasseroli nella conca omonima (galadini e messina, 1993), del fosso canalicchio e di madonna della strada, rispettivamente nella valle del salto e nella conca di scoppito (bosi et al., 1989; bosi, 1989). queste formazioni risultano inoltre tutte incassate in quelle citate a proposito della ua 26. le brecce di s. marco hanno caratteristiche litologiche, spessori e rapporti con i versanti del tutto analoghe a quelle delle brecce bisegna (bosi e messina, 1990) e con le brecce di fonte vedice (bertini e bosi, 1993). ambedue queste formazioni sono state riferite al pleistocene inferiore (bosi e messina 1991; bosi et al. 1995; galadini e messina, 1993). questa attribuzione è stata confermata anche da determinazioni di paleomagnetismo da d’agostino et al., 1997). anche i rapporti con le formazioni correlate con l’unità 21 sono sostanzialmente analoghi. per le unità più recenti, l’unico elemento di correlazione (generalmente collocato a qualche centinaio di migliaia di anni (fornaseri, 1985; narcisi e sposato, 1989)) riguarda la prima comparsa di abbondanti minerali vulcanici che, nel caso della zona in esame, si colloca fra le unità allostratigrafiche 15 e 12. sono invece da riferire alla parte alta del pleistocene superiore le brecce di s. antonio (galadini e galli, 2000) ed almeno uno (blumetti, 1995) dei livelli compresi nell’”allogruppo di arischia”. le correlazioni indicate, delineate anche in bosi et al. (2003), bene si inquadrano in precedenti tentativi di correlazione a scala regionale (bosi e messina, 1991) e sono in accordo con le valutazioni espresse sulla base di dati di paleomagnetismo di messina et al. (2001) che, come già indicato, indurrebbero a riferire al pliocene l’unità allostratigrafica 26 ed al pleistocene inferiore l’unità allostratigrafica 21 e le brecce di s. marco. 237 fig. 7 brecce di san marco. san marco breccias. sedimenti e forme quaternari ... 55.. tteettttoonniiccaa tipologia ed entità delle deformazioni tettoniche quaternarie nell’area studiata sono strettamente legate all’evoluzione del sistema strutturale che si sviluppa in corrispondenza delle dorsali di m. marine e di m. pettino (fig. 1) che rappresentano gli elementi strutturali più importanti del sistema di faglie en echelon destro descritto da galadini (1999). la faglia più settentrionale, interna all’area considerata, è la faglia diretta la cui traccia si sviluppa alla base del versante di m. marine. l’attività quaternaria di questa faglia è dimostrata oltre che dalla conformazione stessa del versante di origine chiaramente strutturale, dalla dislocazione delle brecce di s. antonio e da evidenti scarpate di faglia lungo le quali sono state evidenziate dislocazioni in epoca storica (moro et al., 2002). la faglia più meridionale si sviluppa al piede del versante del m. pettino (al di fuori dell’area considerata), e si prolunga fino entro l’area considerata, nella zona di s. marco, ove disloca le brecce omonime. se si prescinde dalle due faglie citate, indizi di strutture di interesse quaternario sono decisamente scarsi, limitati alla zona di cona della croce e di s. vittorino. nella prima zona sono state osservate alcune faglie che interessano orizzonti ghiaiosi della ua 21, con rigetti di pochi decimetri. nella seconda, due deboli e larghe depressioni, difficilmente riconducibili a normali fenomenologie erosive, inducono a ritenere probabile l’esistenza di due piccole faglie ad attività quaternaria che interessano l’unità allostratigrafica 21. altri elementi strutturali di interesse quaternario sono rappresentati da basculamenti verso ne nei depositi ghiaiosi dell’ua 26 a nord ed a ovest di barete. poco più a sud appare basculata verso sse la superficie um 17 presente a tetto dell’ua 21. ambedue queste rotazioni sono verosimilmente riconducibili all’insieme delle dislocazioni che hanno dato origine al vistoso allargamento del fondovalle dell’aterno, scarsamente compatibile con una “normale” escavazione valliva. 66.. eevvoolluuzziioonnee ggeeoollooggiiccaa i dati raccolti non sono sufficienti ad una ricostruzione dettagliata dell’evoluzione geologica del tratto di valle considerato: mancano infatti conoscenze sufficienti sull’evoluzione della zona che si estende a monte e, sopratutto, di quella che si estende più a valle, nella conca aquilana, oltre la stretta di s. vittorino. ci si deve quindi limitare a delineare questa evoluzione solo nella grandi linee. gli eventi più antichi sono quelli che hanno dato origine ai lembi di spianate di erosione riconducibili ad antichi paleopaesaggi attualmente in posizione subsommitale. si tratta di un argomento tuttora oggetto di un vivace dibattito scientifico che verte sopratutto sull’estensione dei singoli paesaggi (galadini et al., 2003 e relativa bibliografia; coltorti e pieruccini, 2000; bosi, 2002). tutti gli autori sono tuttavia d’accordo che questi paesaggi appartengono ad una o più fasi evolutive più antiche dell’inizio del forte sollevamento tettonico che ha condizionato l’approfondimento del reticolo idrografico e, verosimilmente, l’inizio dell’enucleazione dei bacini in conseguenza dei movimenti lungo le faglie distensive che bordano i bacini stessi (galadini et al., 2003). in base a considerazioni di tipo regionale e ad ipotesi di correlazione con altre conche (bosi e messina, 1991; bosi et al., 2003) questo stadio dell’evoluzione geologica è da riferire ad un generico pliocene. successivamente si assiste ad un imponente e progressivo approfondimento dei solchi vallivi, caratterizzato dall’alternanza di fasi a prevalente incisione verticale e a prevalente spianamento laterale, che si è protratta fino ad oggi dando origine alla successione “terrazzata” descritta al paragrafo 4. sulla base dei dati resi disponibili con lo studio eseguito, nell’ambito di questo approfondimento si possono identificare alcune eventi particolari che possono essere così sintetizzati: 1) fase deformativa che dà origine al basculamento dei depositi della unità allostratigrafica 26 e della unità morfosequenziale 27; 2) importante fase di deposizione alluvionale nel corso della quale si sedimentano i forti spessori delle ghiaie dell’unità allostratigrafica 21; 3) importante fase di deposizione delle caratteristiche brecce di s. marco. secondo la valutazione già espressa a proposito dei riferimenti cronologici (v. par. 4) gli eventi 2 e 3, ambedue riferibili al pleistocene inferiore, avrebbero una estensione molto vasta essendo stati riconosciuti in molte località dell’appennino laziale-abruzzese. alla ricostruzione di una evoluzione geologica così schematizzata sfuggono ovviamente gli eventi responsabili della sedimentazione degli strati compresi nell’allogruppo di arischia, che in alcuni casi indurrebbero ad ipotizzare ambienti di tipo lacustre a vari livelli stratigrafici. 77.. ccoonncclluussiioonnii lo studio eseguito ha permesso di delineare un quadro sommario dell’evoluzione geologica dell’area. pur con questi limiti questo quadro ha definito una successione di eventi deposizionali ed erosivi, rappresentati nello schema di fig. 2, che risulta significativamente più completa di quella alla quale si sarebbe pervenuti sulla base di uno studio puramente stratigrafico. si può inoltre ritenere che l’evoluzione geologica schematizzata possa servire comunque a delineare le tappe più importanti del progressivo approfondimento del reticolo, conseguente al sollevamento tettonico manifestatosi nell’appennino centro-meridionale in epoca successiva a quella degli episodi di spianamento probabilmente pliocenici. llaavvoorrii cciittaattii bagnaia r., blumetti a.m., de luca g., gorini a., marcucci s., marsan p., milana g., salvucci r. e zambonelli e. (1996) morfotettonica dei rilievi a nord della conca aquilana. il quaternario, 99 (1), 287-292. basili r., bosi c. e messina p. (1997) la tettonica quaternaria dell 'alta valle del f. aterno (appennino centrale) desunta dall'analisi di successioni di superfici relitte. il quaternario, 1100 (2), 238 p. messina, c. bosi & m. moro 621-624. basili r., bosi c. e messina p. (1999) paleo-landsurfaces and tectonics in the upper aterno valley (central apennines). z. geomorph. n.f., suppl.bd. 111188, 17-25. bertini t. e bosi c. (1976) – sedimenti continentali probabilmente pliocenici nella valle del salto e nella conca del fucino (rieti e l’aquila). boll. soc. geol. it., 9955, 767-801. bertini t. e bosi c. (1993) la tettonica quaternaria della conca di fossa (l'aquila). il quaternario, 66 (2), 293-314. blumetti a. m. (1995) neotectonic investigations and evidence of paleoseismicity in the epicentral area of the january-february 1703, central italy, earthquakes. in: serva l. e slemmons d. b. (eds.), a.e.g. special publication no. 66, perspective in paleoseismology, 83-100. blumetti a. m., cavinato g. p. e tallini m. (1996) evoluzione plio-quaternaria della conca di l 'aquila-scoppito: studio preliminare. i l quaternario, 99 (1), 281-286. bosi c. (1975) osservazioni preliminari su faglie probabilmente attive nell'appennino centrale. boll. soc. geol. it., 9944, 827-859. bosi c. (1989) – tentativo di correlazione fra le successioni plio-pleistoceniche. in "elementi di tettonica pliocenico-quaternaria ed indizi di sismicità olocenica nell'appennino laziale-abruzzese". guida all'escursione della s. g. i., 89-96. esa grafica. bosi c. (2002) – l’interpretazione delle superfici relitte nell’appennino centrale: il caso della zona di colf iorito (prov. perugia e macerata). i l quaternario, 1155(1), 69-82. bosi c., caiazzo c., cinque a. e messina p. (1996). le superfici relitte della regione fucense (appennino centrale) ed il loro possibile significato nella ricostruzione della evoluzione geologica. i l quaternario, 9966, 381-386. bosi c., galadini f. & messina p. (1995). stratigrafia plio-pleistocenica della conca del fucino. il quaternario, 88 (1), 83-94. bosi c., galadini f., giaccio b., messina p., sposato a. (2003) plio-quaternary continental deposits in the latium-abruzzi apennines: the correlation of geological events across different intermontane basins. il quaternario, 1166(1bis), 55-76. bosi c. e messina p. (1990) elementi di stratigrafia neogenico-quaternaria tra il fucino e la valle del giovenco (l'aquila). mem. descr. carta geol. it., 3388, 85-96. bosi c. e messina p. (1991) ipotesi di correlazione fra successioni morfo-litostratigrafiche plio-pleistoceniche nell'appennino laziale-abruzzese. studi geologici camerti, crop 1111, 275-263. bosi c., messina p. e moro m. (2003) – nuovi procedimenti cartografici per il quaternario continentale: l’esempio della carta geologica dell’alta valle dell’aterno. il quaternario, 1166(1), 127-138. bosi c., messina p. & sposato a. (1989) la depressione del salto. in "elementi di tettonica pliocenicoquaternaria ed indizi di sismicità olocenica nell'appennino laziale-abruzzese". guida all'escursione della s. g. i., 89-96. esa grafica. cande s. c. & kent d. v. (1995). revised calibration of the geomagnetic polarity time scale for the late cretaceous and cenozoic, j. geophys. res. 110000, 6093-6095. coltorti m. e pieruccini p. (2000). a late lower pliocene planation surface across the italian peninsula: a key tool in neotectonic studies. journ. geodynamics, 2299, 323-328. d'agostino, n., speranza, f. e funiciello, r. (1997). le "brecce mortadella" dell'appennino centrale: primi risultati di stratigrafia magnetica. il quaternario, 10 (1), 385-388. fornaseri m. (1985). geochronology of volcanic rocks from latium (italy). rend. soc. it. miner. petrol., 4400, 73-106. galadini f. (1999) pleistocene change in the central apennine fault kinematics, a key to decipher active tectonics in central italy. tectonics, 1188, 877-894. galadini f. e galli p. (2000) active tectonics in the central apennines (italy) – input data for seismic hazard assessment. natural hazard, 2222, 225-270. galadini f. e messina p. (1993). stratigrafia dei depositi continentali, tettonica ed evoluzione geologica quaternaria dell'alta valle del f. sangro (abruzzo meridionale). boll. soc. geol. it., 111122, 877-892. galadini f., messina p., giaccio b. e sposato a. (2003). early uplift history of the abruzzi apennines (central italy): available geomorphological constraints. quaternary international 110011--110022, 125-135. messina p., moro m. e speranza f. (2001). primi risultati di stratigrafia magnetica su alcune formazioni continentali dell'alta valle dell'aterno (italia centrale). il quaternario, 1144, 167-172. moro m., bosi v., galadini f., galli p., giaccio b., messina p. e sposato a. (2002). analisi paleosismologiche lungo la faglia del m. marine (alta valle dell'aterno): risultati preliminari. il quaternario, 1155,, 267-278. narcisi b. e sposato a. (1989). elementi di cronologia dell’attività vulcanica. in "elementi di tettonica pliocenico-quaternaria ed indizi di sismicità olocenica nell'appennino laziale-abruzzese". guida all'escursione della s. g. i., 89-96. esa grafica. 239 ms. ricevuto il 15 luglio 2003 testo definitivo ricevuto il 23 settembre 2003 ms. received: july 15, 2003 final text received: september 23, 2003 sedimenti e forme quaternari ... imp.centamore eelleemmeennttss ttoo ccoorrrreellaattee mmaarriinnee aanndd ccoonnttiinneennttaall sseeddiimmeennttaarryy ssuucccceessssiioonnss iinn tthhee ccoonntteexxtt ooff tthhee nneeootteeccttoonniicc eevvoolluuttiioonn ooff tthhee cceennttrraall aappeennnniinneess eerrnneessttoo cceennttaammoorree11,, ffrraanncceessccoo ddrraammiiss22,, ggiiaannddoommeenniiccoo ffuubbeellllii22,, ppaaoollaa mmoolliinn22 && sstteeffaanniiaa nniissiioo33 1 università degli studi di roma “la sapienza”, dipartimento di scienze della terra, piazzale a. moro, 5 00100 roma 2 università degli studi “roma tre”, dipartimento di scienze geologiche, largo san leonardo murialdo, 1 00146 roma 3 dipartimento dei servizi tecnici nazionali, servizio geologico, via curtatone, 3 00185 roma abstract the central apennines show geologic and geomorphic features that report the strong influence of extensional tectonics and regional uplift on their recent evolution. the goal of this paper is to find out the time constraints of the chain uplift, focusing on the elements of correlation between marine and continental successions on both the adriatic and tyrrhenian sides. all along the range, the most ancient landforms are gently rolling or flat summit surfaces. on the tyrrhenian side, the interaction between the chain uplift and the extensional tectonics related to the opening of the tyrrhenian basin, generated several neoautoctonous basins that are older in tuscany (since the tortonian) and younger in the latium-abruzzo area (since the pliocene). on the adriatic side, the combined action of uplift and climatic changes, produced several depositional sequences, separated by angular unconformities. in the western basins, progressively coarsening upward sediments, corresponding to the globorotalia crassaformis biozone, are found. at valle ricca, in the upper section of these deposits, a 2.1 myr old volcanic layer, corresponding to the base of the globorotalia inflata biozone, is present. the valle ricca succession is truncated by an erosion surface over which marine and brackish sandy clay (argille sabbiose del chianitevere) lay down. similarly, in the periadriatic basin, a volcanic layer, dated 2.1 myr, has been found at bellante, in the upper part of a pelitic sequence. an angular unconformity separates this sequence from overlaying conglomerate and sand, recording a progressively eastward shifting of the coastline as a consequence of the uplift. contemporaneously, extensional tectonics progressively affected the apennine chain giving rise to a number of intermontane depressions, within which coarse breccia and lacustrine-alluvial deposits were deposited. in the rieti and l’aquila basins, the finding of equus stenonis and mammuthus meridionalis refer the basal part of these deposits to an age not older than the lower pleistocene. around 0.8 myr b.p., in correspondence with a base level drop induced by a sudden increase of uplift rate, the coastline rapidily shifted seawards and littoral sandy-pebbly sediments were deposited along both sides of the apennines. contemporaneously, increased stream erosion rates gave rise to the present valley network, within which the interaction of river incision and climate changes generated several orders of alluvial terraces. in this contest, a hunched backward river erosion breached most of intramontane depressions, draining off the lakes and causing the erosion of the basin sedimentary sequence. in conclusion, according to all these considerations, we hypothesize that the topographic growth of the range was slow until the end of the lower pleistocene, when a strong increase of the uplift rate affected the chain and the surrounding coastal belts. riassunto l’appennino centrale presenta caratteri geologici e geomorfologici che documentano l’intensa influenza della tettonica estensionale e del sollevamento regionale sulla sua evoluzione recente. in questo lavoro si intendono evidenziare gli elementi di correlazione tra le successioni marine e continentali della fascia periadriatica abruzzese e peritirrenica laziale, al fine di proporre dei vincoli temporali all’evoluzione recente dell’appennino. gli elementi geomorfologici più antichi, riscontrabili lungo tutta la catena appenninica, sono rappresentati da superfici sommitali gentilmente ondulate o pianeggianti. sul versante occidentale la tettonica distensiva legata all’apertura del tirreno ha generato una complessa serie di bacini neoautoctoni più antichi in toscana (dal tortoniano) e più recenti nell’area laziale (dal pliocene). sul versante adriatico il sollevamento della catena ha dato origine a discordanze angolari che individuano numerose sequenze sedimentarie in assetto monoclinalico. sul versante tirrenico della catena, si depositano sedimenti progressivamente più grossolani riferibili alla fine della biozona a globorotalia crassaformis. in particolare, a valle ricca, al tetto di questi depositi e alla base della biozona a globorotalia inflata, è stato trovato un livello vulcanico datato 2.1 ma. su tale successione si appoggiano in discordanza le “argille sabbiose del chiani-tevere” di ambiente marino e salmastro. similmente, sul versante adriatico, presso bellante, è stato rinvenuto un livello vulcanico datato 2.1 ma nella parte superiore di una sequenza di depositi pelitici. questa è troncata al tetto da una discordanza angolare che la separa da sedimenti conglomeratici e sabbiosi. contemporaneamente, la tettonica estensionale interessa progressivamente la catena generando una serie di bacini intermontani, delimitati da faglie normali. i materiali di riempimento sono costituiti alla base da sedimenti grossolani che passano verso l’alto a depositi alluvionali e fluvio-lacustri. nelle conche di rieti e de l’aquila il ritrovamento di equus stenonis e mammuthus meridionalis consente di riferire la parte basale di questi sedimenti ad un’età non più giovane del pleistocene inferiore. intorno a 0.8 ma b.p., in concomitanza con un forte abbassamento relativo del livello di base, legato ad un subitaneo incremento del tasso di sollevamento, si verifica un più marcato avanzamento delle linee di costa, accompagnato dalla messa in posto di depositi sabbioso-ciottolosi di ambiente litorale lungo i margini occidentale e orientale dell’appennino. contemporaneamente, un aumento del tasso di incisione fluviale dà origine all’attuale sistema di valli, all’interno delle quali, per effetto dell’interazione tra l’aumento dell’erosione fluviale e le variazioni climatiche, si sono formati più ordini di terrazzi alluvionali. in tale contesto, l’erosione regressiva dei corsi d’acqua ha profondamente inciso le soglie della maggior parte dei bacini intermontani, prosciugando i laghi ed erodendo gran parte dei depositi presenti. in conclusione, in base a queste considerazioni si può ipotizzare che la crescita topografica della catena appenninica è stata lenta fino alla fine del pleistocene inferiore, quando si è verificato un forte incremento del tasso di sollevamento. keywords: central apennines, uplift, neotectonics parole chiave: appennino centrale, sollevamento, neotettonica il quaternario italian journal of quaternary sciences 1166(1bis), 2003, 77-87 78 e. centamore et al. 11.. iinnttrroodduuccttiioonn the topographic growth of the italian apennines was slow during the phase of major plate convergence and crustal shortening which occurred throughout the miocene and pliocene, but increased significantly in the pleistocene (ciaranfi et al., 1983; dramis, 1992; tortorici et al., 1995; argnani et al., 1997; bertotti et al., 1997; carminati et al., 1999; calamita et al., 1999; coltorti & pieruccini, 2000). this uplift is testified by geomorphic and geologic evidences throughout the chain. in the central apennines the oldest landforms, that are gentle rolling or flat summit surfaces, seem to be connected eastward, in the periadriatic basin, to the base of pliocene marine deposits (centamore & nisio, 2003). on the western flank and in the chain, the extensional tectonics related to the opening of the tyrrhenian sea generated several neoautoctonous basins that are older in tuscany (since the tortonian, bossio et al., 1993) and younger in latium and abruzzo (since the pliocene, ambrosetti et al., 1978). this paper examines most of the available literature data about the continental and marine successions cropping out on both sides of the central apennines and within the intermontane basins. we focus on the sedimentary features and stratigraphic elements that could provide time constraints on the recent evolution of the study area, in the context of an uplifting mountain chain affected by extensional tectonics. reviewing the available paleontologic and radiometric data, we point out the main stratigraphic elements that allow the correlation between the sedimentary successions cropping out in the margins of the chain and in the intermontane basins. the results are consistent with a mostly continuous and slow uplift, characterized by a strong increase of the uplift rate by the end of lower pleistocene. 22.. ggeeoollooggiiccaall sseettttiinngg the italian apennines are a fold and thrust chain that, since around 15 myr, has been affected by extensional tectonics as a consequence of the backarc opening of the tyrrhenian basin; the formation of this basin induced the eastward-southeastward migration of the apennines and the foredeep (malinverno & ryan, 1986; patacca & scandone, 1989; patacca et al., 1990; mantovani et al., 1996; faccenna et al., 2001). clastic deposits shed from mesozoic and early cenozoic sediments have been deposited in foredeep and thrust-top basins during the late miocene-early pliocene, in connection with local emergence and erosion of the continental land (centamore & micarelli, 1991; calamita et al., 1999; cavinato & de celles, 1999; cipollari et al., 1999 a, b). since late pliocene through late early pleistocene, a decrease in the rate of the eastward migration of the apennine chain (mantovani et al., 1996) and minor changes in the backarc extension axis were temporally coincident with an increase of the regional emergence of the chain (hippolyte et al., 1994). several authors, citing different proxies among which the occurrence of low-relief summit surfaces in several high-standing parts of the apennines, have appealed to a significant increase in the emergence of all the apennines by the middle pleistocene (ambrosetti et al., 1982; ciaranfi et al., 1983; brancaccio et al., 1984; colella et al., 1987; dramis, 1992; tortorici et al., 1995; amato & cinque, 1999; ascione & cinque, 1999; calamita et al., 1999; coltorti & pieruccini, 2000; d’agostino et al., 2001). the study area, located in the central apennines (fig. 1), is underlain by mesozoic to early cenozoic platform carbonate, marls and terrigenous deposits that are deformed by e-ne-verging thrusts (parotto & praturlon, 1975; patacca et al., 1990; bigi et al., 1991). as for the rest of the chain, the extensional tectonics, related to the opening of the tyrrhenian basin, progressively affected the study area, generating several neoautoctonous basins on the western margin (bossio et al., 1993; ambrosetti et al., 1978) and intermontane depressions in the axial part of the range (dramis, 1992). in the periadriatic sector, divided into minor basins by transversal tectonic structures, the uplift induced a progressive tilting of the marine sediments that generated clinoforms dipping to e-ne (centamore et al., 1990, 1991; bigi et al., 1997). present seismicity indicates that the modern chain continues to be affected by tectonic shortening on the adriatic flank and extension on the tyrrhenian flank, although most of the extensional activity is concentrated along the more elevated axial sectors of the chain (royden et al., 1987; console et al., 1988; gasparini et al., 1988; patacca & scandone, 1989; patacca et al., 1990; lavecchia et al., 1994; amato et al., 1997; montone & mariucci, 1999; negredo et al., 1999; frepoli & amato, 2000). 33.. mmaarriinnee aanndd ccoonnttiinneennttaall ssttrraattiiggrraapphhyy ooff tthhee ssttuuddyy aarreeaa all the sites mentioned in the following paragraphs are reported in fig. 1. 33..11 llaattee mmiioocceennee - lloowweerr pplliioocceennee on the western flank of the apennines, since the tortonian to the early messinian, the extensional tectonics related to the opening of the tyrrhenian sea generated several basins: here the stratigraphic sequences are characterized by the occurrence of fluvial and lacustrine deposits, gradually evolving to littoral sand and clay (fazzini et al., 1972; bossio et al., 1993; carboni et al., 1994; testa, 1995). subsequently, the sedimentation became evaporitic as a response to the messinian salinity crisis (parotto & praturlon, 1975; patacca et al., 1990; roveri et al., 2001). after the messinian regression, marked by an erosion surface, in the lower pliocene, conglomerate, sandy and clayey sediments were deposited in a progressively deeper sea (brandi et al., 1970; ambrosetti et al., 1978; buonasorte et al., 1991; barberi et al., 1994; carboni et al., 1994). the change of depositional environment depended on the marine ingression as well as on the structural pattern of depressed basins with elevated and partially emerged ranges (ambrosetti et al., 1978). in the more western basins the deposition began during the globorotalia margaritae biozone, whereas more to the east (tiber basin) the so-called “argille di fabro” deposits may be referred to the globorotalia puncticulata biozone (ambrosetti et al., 1987; buonasorte et al., 1991; carboni et al., 1994). in the same time interval, the foredeep migrated eastward: valle latina, val roveto, lago del saltotagliacozzo depression, laga and cellino basins (cipollari & cosentino, 1995; centamore et al., 1990; centamore et al., 1991; bellotti, 1991; bigi et al., 1997). the turbidites lying down in the foredeep are unconformably overlain by littoral sand and fluvial-delta polygenic conglomerate (valle del liri, le vicenne, piagge, rigopiano, m. coppe), deposited between late messinian and lower pliocene (centamore et al., 1991; cipollari & cosentino, 1995; bigi et al., 1997; cipollari et al., 1999a, b). 33..22 mmiiddddllee –– eeaarrllyy uuppppeerr pplliioocceennee on the western flank of the apennines, in northern latium, at the disappearing of globorotalia puncticulata and at the first occurrence of globorotalia crassaformis, the sediments changed from bathial clay (“argille di fabro”) to littoral sand (“sabbie a flabellipecten”, “calcare di tarquinia”) and shoreline conglomerate (“conglomerato di città della pieve”) (brandi et al., 1970; ambrosetti et al., 1987; barberi et al., 1994; carboni et al., 1994). these sediments are finer westward, becoming coarser and coarser towards the present chain (buonasorte et al., 1991). the general pattern of the adriatic margin was controlled by structural elements oriented nw-se and ne-sw that defined several basins (teramo, chieti, and vasto basins) alternated with more elevated longitudinal ridges (bigi et al., 1997). in these sectors, notwithstanding marked differences in sedimentation and tectonic evolution, the deposition continued in a marine environ79elements to correlate marine and continental ... ment, producing a thick stratified succession with several minor sequences separated by angular unconformit ies (bigi et al., 1997). these sediments, which unconformably overlay the “laga flysch”, “cellino flysch”, and the “marne del vomano” formations (cantalamessa et al., 1986; bigazzi et al., 2000; bigi et al., 2000), vary from conglomerate to sand and clay; their base could be referred to the globorotalia crassaformis zone (centamore & nisio, 2003). 33..33 uuppppeerr pplliioocceennee –– lloowweerr pplleeiissttoocceennee in the upper pliocene, on the western margin of the chain, sedimentation persisted with the deposition of marine clay and sandy clay in the civitavecchiamontalto di castro area, in the tiber basin, and more to south, in the ardea basin and pontina plain, even if the successions have been largely truncated by subsequent erosion (carboni, 1975; carboni et al., 1993, carboni et al., 1994; faccenna et al., 1994). at valle ricca a volcanic layer, dated 2.1 myr, has been reported from the upper part of these deposits (carboni et al., 1993). more in general, the upper pliocene succession is cut by an erosion surface on which marine and brackish sandy clay lay down (malatesta & zarlenga, 1985; ambrosetti et al., 1987; buonasorte et al., 1991; carboni et al., 1994). these sediments (“argille sabbiose del chianitevere” in the tiber basin sequence), referred to the lower pleistocene because of the microfacies typical of the globorotalia inflata pp. and of the globigerina cariacoensis zones (ambrosetti et al., 1987; carboni & di bella, 1996), are connected to ancient shorelines, presently uplifted at elevations ranging from 145 to 480 m a.s.l. (girotti & piccardi, 1994). in sectors closer to the mountain chain, upper pliocene continental clay with fig. 1 location of the study area. the main tectonic structures and the localities mentioned in the text are reported. lleeggeenndd main thrust main normal faults sa-ta: salto tagliacozzo depression 1: le vicenne 2: piagge 3: rigopiano 4: monte coppe 5: valle ricca 6: fossa 7: scoppito 8: bellante 9: giovenco valley 10: cupaello 11: polino 12: san venanzo 13: colle fabbri 14: como valley 15: fiorata 16: catignano 17: colle picconetto 80 peaty lens (“argil le grigie inferiori”) crops out (ambrosetti et al., 1987). they are unconformably overlain by fluvial-lacustrine sandy clay (“complesso argilloso-sabbioso”) dated lower pleistocene according to the fossil content (ambrosetti et al., 1987; 1995). in the tyrrhenian piedmont belt, santernian infra-littoral sandy clay crop out (di bella, 1994), whereas more to the west, in the coastal sectors, circalittoral pelitic sediments with rare sand layers are dated as emilian (carboni, 1993). extensional tectonics affected the chain producing intermontane basins (demangeot, 1972; calamita et al., 1982; dramis, 1992). these basins are partially filled with sedimentary sequences consisting, from the bottom to the top, of coarse breccia and blocks, lacustrine clayey layers and alluvial conglomerate, gravels and sand, which locally are interfingered each other (bertini & bosi, 1993; cavinato, 1993; galadini, 1999; aa.vv., 2002). in particular, the coarse breccia and the huge blocks locally crop out several kilometers far from any slopes. in the fucino and l’aquila-fossa basins, as well as in the salto and sangro valleys, lacustrine deposits containing huge blocks (“megabreccia”) have been roughly referred to pliocene (demangeot, 1972; bosi & messina, 1991; bertini & bosi, 1993; galadini & messina, 1994; galadini, 1999). in particular, in the fucino basin, siltstone and claystone interbedded with “megabreccia” and characterized by no diagnostic fauna assemblages (ostracods and mollusks), constitute the “lower units” (zarlenga, 1987; cavinato et al., 2002), that correspond to the lower part of the “aielli-pescina supersyntheme” in aa.vv. (2002). the finding of equus stenonis (late villafranchian) in the basal part lacustrine sedimentary sequence of rieti (“upper depositional unit”; cavinato et al., 1987), and of elephas meridionalis vestinus (late villafranchian) in similar deposits within the l’aquila-scoppito basin (esu et al., 1991) refer those sediments to the lower pleistocene, without excluding an older age for the underlying alluvial gravel and sand. on the adriatic margin, the marine sedimentary environment persisted with the deposition, from the bottom to the top, of neritic-littoral sand and of thick pelitic clay with lenses and layers of conglomerate (cantalamessa et al., 1986; centamore & micarelli, 1991; bigi et al., 1997). this sequence and the minor cycles within it are bounded by angular unconformities in the innermost and marginal sectors of the basin, while in the deeper sectors the corresponding deposits are characterized by higher thickness and depositional continuity (cantalamessa et al., 1986; bigi et al., 1997; bigazzi et al., 2000; centamore & nisio, 2003). at bellante, in the upper part of the sequence, a tephra layer, dated 2.13±0.10 myr (bigazzi et al., 2000), has been found just below a minor erosion surface (nisio, 1997) over which neritic conglomerate and sand unconformably lay (centamore & micarelli, 1991; cantalamessa et al., 2002). these latter sediments are truncated by another erosion surface which records a hiatus corresponding to the upper portion of the globorotalia inflata zone (late upper pliocene); they are unconformably overlain by sicilian sandy and gravelly sediments, deposited in a submerged and then emerged beach environment, thus recording the progressive eastward shift of the coastline (cantalamessa et al., 1986; bigi et al., 1997; bigazzi et al., 2000). 33..44 mmiiddddllee pplleeiissttoocceennee around 0.8 myr, on the tyrrhenian flank of the apennines the depositional environment changed laterally from marine littoral in the more depressed areas (e.g. piana pontina) (casto & zarlenga, 1997, barbieri et al., 1999) to continental/marine transitional (at ponte galeria, west of rome) and continental in the area of rome (marra & rosa, 1995). in the intermontane basins, the lower pleistocene lacustrine clay are generally unconformably overlain by coarser sediments which record the transition to alluvial environment. these sediments are frequently entrenched within the lacustrine deposits. the finding of equus altidens (lower-middle galerian) in a buried soil at the base of coarse alluvial sediments in the giovenco valley allows to refer them to the middle pleistocene (blumetti et al., 1997). in the l’aquila-fossa basin, lacustrine sand and clay are dated as middle pleistocene by the occurrence of elephas (p.) antiquus (galerian) (esu et al., 1991; bertini & bosi, 1993). magma upwelling along pre-existing nw-se trending fracture allowed the development of the intraapenninic volcanic vents of cupaello, polino, san venanzo, and colle fabbri (barberi & innocenti, 1980; michetti & serva, 1990; cavinato et al., 1994). in particular, in the rieti basin, the lava of cupaello (dated around 0.4 myr) flowed over a fault slope, related to the extensional tectonics that generated the present geometry of the basin itself (barberi & innocenti, 1980). at least two orders of middle pleistocene fluvial terraces are present along the main valleys (bigi et al., 1995; aa.vv., 2002). in the corno valley the oldest fluvial terraces, located at an elevation of 940 m a.s.l. and around 300 m above the present valley bottom, contain an ash layer dated 0.520±0.005 myr (aa.vv., 2002). moreover, these terrace deposits are locally interfingered with alluvial fan sediments, in which remnants of megaloceroides verticornis, megaloceros cf. m. savini, stephanorinus sp, elephantidae gen., elephas antiquus have been found; this fossil assemblage is typical of the lower part of middle pleistocene (aa.vv., 2002). reworked volcanic layers, dated 0.562±0.004 myr, have been found in sand and carbonate silt (upper part of the “aielli-pescina supersyntheme”) around fiorata, in the sulmona basin (aa.vv., 2002). in the fucino area the older deposits of the “upper units” (cavinato et al., 2002), corresponding to the upper part of the “aielli-pescina supersyntheme” and to the “catignano syntheme” (aa.vv., 2002), are fluvial and deltaic sand and conglomerate, interfingered with lacustrine clay and unconformably overlying the “lower units” (cavinato et al., 2002). a volcanic level found in a core drilled in the lacustrine sediments has been dated 0.541±0.009 myr by 39ar/40ar method (narcisi, 1995). on the adriatic margin of the central apennines, over an erosion surface that presently reaches a maximum elevation of 470 m a. s. l., alluvial deposits lay down (cantalamessa et al., 1986; bigi et al., 1995). at colle picconetto, near catignano, a buried soil overlain by an ash layer dated 0.48±0.04 myr, has been referred to middle pleistocene because of the small mammal faunas and continental molluscs assemblage (marcolini et al., 2000). a similar faunal assemblage has been found in the valdarno basin, within alluvial gravel and sand overlain by a volcanic layer dated around 0.5 e. centamore et al. 81 myr (bigazzi et al., 2000). in middle pleistocene two cold and arid periods induced the formation of stratified slope deposits (coltorti & dramis, 1988). north of the study area, in the norcia and cascia basins, at the top of the oldest sediments some soils developed; they have been dated 0.25-0.29 myr by k/ar method (coltorti et al., 1987). the stratified slope deposits are often interfingered with fluvial sediments of the terraces. 33..55 uuppppeerr pplleeiissttoocceennee--hhoolloocceennee along the tyrrhenian coastal belt, several orders of marine terraces developed in the upper pleistoceneholocene. terraced marine sediments containing strombus bubonius (tyrrhenian stage) are presently located at elevation ranging from 27 m (tarquinia) to 20 m (palidoro) and 6-12 m (southern latium) (blanc, 1935, 1936; hearty & dai pra, 1986; radtke, 1986; dai pra, 1995 and references within; palieri & sposato, 1988). pebbly and gravely continental deposits, cropping out close to pomezia, have been referred to tyrrhenian by malatesta & zarlenga (1985). in the pontina plain, coastal, lagoon, and eolian sediments have been dated as upper pleistocene and holocene (barbieri et al., 1999; sevink et al., 1984). more to the north, a 50 m thick clayey and sandy sequence, deposited in a coastal-lagoon-brackish environment, has been drilled close to tiber river mouth (carboni, 1993). in the apenninic range, the lacustrine environment, characterized by the deposition of clayey, sandy clayey and peaty sediments, persisted, where the intermontane basins like fucino continued to be internally drained (d’agostino et al., 2001). moraine, loess, slope deposits, alluvial fan, and fluvio-lacustrine sediments, precisely dated by the occurrence of tephra layers, record the strong climatic changes of the upper pleistocene-holocene (frezzotti & giraudi, 1992; giraudi, 1998 a, b, 2001). the interaction of these climatic variations with the deep stream incision caused by the regional uplift continued to form alluvial terraces (coltorti & dramis, 1988; dramis, 1992). in the velino valley, the third order of alluvial terraces contains travertine dated 0.080-0.18 myr by u/th method (carrara et al., 1992). on the adriatic side of the range, continental deposits (alluvial fan and alluvial plain gravels) containing silty-travertine layers have been referred to the upper pleistocene-holocene (cantalamessa et al., 1986, bigi et al., 1997; cantalamessa et al., 2002). in particular, three orders of fluvial terraces formed in the valleys; the younger order developed in the holocene (calderoni et al., 1996). 44.. ddiissccuussssiioonn the results from reviewing the available literature on the continental and marine successions cropping out on both sides of central apennines and in the intermontane basins highlight some stratigraphic elements that provide time constraints for the recent evolution of the study area, in the context of an uplifting mountain chain affected by extensional tectonics. after the messinian regression, in the late miocene-lower pliocene a marine transgression occurred in the backarc basins on the western flank of the chain, whereas to the east littoral sand and fluvial and delta conglomerate unconformably overlay turbidite deposits in the foredeep and thrust-top basins. the conglomerate were mostly supplied with locally outcropping carbonatic and flysch rocks, even if clasts were originated from very distant sources (accordi & carbone, 1988; cipollari et al., 1999 b). the well expressed erosion surface overlain by coarse conglomerate deposited in a continental environment suggests that the forming apennines were partially emerged and eroded by surface processes. in middle pliocene, on the western flank of the range, the depositional environment changed from bathial to littoral and shoreline (brandi et al., 1970; ambrosetti et al., 1987; barberi et al., 1994) indicating elements to correlate marine and continental ... fig. 2 sketch of the tiber basin in the southern umbria stratigraphy (from ambrosetti et al., 1987, modified) as an example of basin evolution on the tyrrhenian flank of the apennines. marine succession: af) “argille di fabro”; sf) “sabbie a flabellipecten”; ccp) “conglomerato di città della pieve”; asct) “argille sabbiose del chiani-tevere”. continental succession: agi) “argille grigie inferiori”; cas) “complesso argilloso-sabbioso”; tl) peat and slime; ta) travertine; cds) thick debris deposits. 82 marine regression. a depositional hiatus after 2.1 myr followed (fig. 2), corresponding to at least a portion of the globorotalia inflata zone (upper pliocene). this relatively strong sea level lowering occurred regionally, as suggested by the erosion surface above a 2.1 myr old volcanic layer at bellante, in the periadriatic basin (fig. 4). the presence of angular unconformities within the sedimentary sequence testifies the progressive tilting of the periadriatic basin as a consequence of the interaction of the slow emersion of the chain and the sea level changes. the middle-upper pliocene marine deposits are coarser close to the flanks of the present chain indicating that the axial part of the apennine had already emerged (fig. 3). here, geomorphic processes shaped a low relief landscape whose fragmented relics are presently visible in the summit portion of the chain. in the emerged apenninic range, between the upper pliocene and lower pleistocene, extensional tectonics gave rise to nw-se trending normal faults that, displacing the previous low relief landscape, generated several intermontane depressions (fig.3). the first deposits associated to the formation of these basins are coarse breccia and blocks, that are interfingered and overlaid by lacustrine sediments. the coarse breccia have been probably generated on bare slopes in colddry conditions during the upper pliocene (shackleton et al., 1984; horowits, 1989). gravitational processes, probably triggered by high magnitude earthquakes, mobilized this weathering material together with the huge blocks and transported them up to some kilometers far from the feeding areas (demangeot, 1965; aa.vv., 2002). unfortunately, there are no precise chronological data for this event, but since the breccias are overlain e. centamore et al. fig. 3 – sketch of the lowe pliocene-lower pleistocene evolution of the eastern apennine flank and of the adjacent periadriatic basin (from centamore & nisio, 2003, modified). whereas the apennines were uplifting, being affected by extensional tectonics and shaped by surface processes, in the periadriatic basin several cycles of marine deposits lay down and successively were tilted and emerged as e result of the uplift and of the progressive eastward shifting of the coastline. aappeennnniinnee tthhrruusstt bbeelltt ssuummmmiitt ssuurrffaaccee ((ssoo)) iinnttrraammoonnttaarree ddeepprreessssiioonnss aaddrriiaattiicc ffoorreellaanndd ppeerriiaaddiiaattrriicc bbaassiinn ppeerriiaaddiiaattrriicc mmoonnoocclliinnee lloowweerr pplliioocceennee ssttaaggee mmiiddddllee pplliioocceennee ssttaaggee mmiiddddllee--uuppppeerr pplliioocceennee ssttaaggee llaattee pplliioocceennee--lloowweerr pplleeiissttoocceennee ssttaaggeess by lower pleistocene deposits, we could hypothesize that they could be referred to the same cold and dry climatic phase that induced marine regression after 2.1 myr, in correspondence with the globorotalia inflata biozone. during lower pleistocene, as a consequence of more humid and warm climatic conditions (shackleton et al., 1984; horowits, 1989) in the intermontane basins, the sedimentation became coarser, but the persistence of lacustrine or low gradient fluvial environment suggests that the basins were internally drained (d’agostino et al., 2001). in the santernian, marine transgression occured in both the adriatic and tyrrhenian margins (figg. 2, 4). around 0.8 myr b.p., on both flanks of the range, the marine regression relative to the isotopic stage 22 induced backward coastline shift ing and the deposit ion of transit ional marine/continental and continental deposits. contemporaneously a marked increase in the uplift rate of the apenninic range occurred; this strong uplift, reported all along the italian peninsula (ambrosetti et al., 1982; ciaranfi et al., 1983; dramis, 1992; moretti, 1993; tortorici et al., 1995; calamita et al., 1999; coltorti & pieruccini, 2000; d’agostino et al., 2001), induced widespread deep fluvial erosion (fig. 3). therefore, most intermontane depressions were reached by the headward river erosion which breached the basin thresholds, draining off the lakes and cutting the filling sediments. the interaction between the uplift and the strong climatic changes of the middle-upper pleistocene generated several orders of fluvial and marine terraces along the tyrrhenian coast. the formation of the fluvial and marine terraces was alternate because during cold periods, the sea level drop induced rivers to incise downstream, whereas large amounts of sediments from poorly vegetated valley slopes were washed in the rivers upstream. conversely, during warm periods, the sea level rise induced aggradation towards the mouth and incision upstream. on the adriatic flank, the lower pleistocene coastal deposits, uplifted and tilted to the ne, were isolated on the interfluves by the strong stream incision, whereas five orders of fluvial terraces formed along the valleys unti l the holocene. on the basis of the reviewed data and of their discussion we could point out that the topographic growth of the apennines began at least in the miocene when the extension was affecting only the western portions of the deforming thrustbelt. no data suggest that strong changes of the uplift rate occurred unti l the end of lower pleistocene, when a long-wave uplift affected the apennines and the tyrrhenian and adriatic coastal belts. this is confirmed by the present maximum elevation (470-480 m) of the lower pleistocene shorelines and relative deposits on both flanks of the chain (girotti & piccardi, 1994; bigi et al., 1995). on the latium coastal belt, the maximum elevation of the tyrrhenian marine ter83elements to correlate marine and continental ... fig. 4 sketch of the pliocene-middle pleistocene evolution of an intermontane depression (from centamore & nisio, 2003, modified). a) in the pliocene, the forming apennines were partially emerged and surface processes shaped a low relief landscape presently located on the summit portion of the chain. b) in the upper pliocene-lower pleistocene the intermontame depressions were filled mostly by coarse breccia and lacustrine deposits. c) at the end of the lower pleistocene the lacustrine and/or low gradient fluvial deposits suggest that the basins were internally drained. d) in the middle pleistocene, a marked increase in the uplift rate induced the headward stream erosion to enter in the intermontane basins and to incise their deposits. old landscape minor erosional surfaces fault scarp fault scarp fault scarp lacustrine deposits fluvio-lacustrine deposits fluvio-lacustrine deposits coarse breccia coarse breccia coarse breccia fluvial terraces a) b) c) d) race is around 27 m (palieri & sposato, 1988). according to these data and their discussion, we could roughly calculate an uplift rate of around 0.5 mm/yr in the last ~1 myr. 55.. ccoonncclluussiioonn in this paper we examine most of the available literature data on the continental and marine successions cropping out on both sides of the central apennines and within the intermontane basins. we focus on the sedimentary features and stratigraphic elements that could provide time constraints on the recent evolution of the study area in the context of an uplifting mountain chain affected by extensional tectonics. the obtained results are consistent with a mostly continuous and slow uplift, started in the upper miocene-lower pliocene and followed by a phase of higher uplift rate by the end of lower pleistocene. this uplift increase induced an equally strong change in the landscape of the apennines, as suggested by the geomorphological and stratigraphical evidences of the intermontane basins, not only in the latium-abruzzo area, but also all along the central apennines (for example norcia, colfiorito, terni basins). they indicate that the general drainage system changed from internally drained fluvial-lacustrine basins to open river systems, delivering their sediments from the intermontane basins to the adriatic and tyrrhenian seas. rreeffeerreenncceess aa.vv., 2002 stratigrafia dei depositi continentali, carg abruzzo, submitted. accordi g. & carbone f. (eds), 1988 carta delle lithofacies del lazio-abruzzo e aree limitrofe, p. f. geodinamica-c.n.r., quad. la ricerca scientifica, 114444 (5). amato a. & cinque a., 1999 erosional surfaces of the campano-lucano apennines (s. italy): genesis, evolution, and tectonic implications, tectonophysics, 331155, 251-267. amato a., chiarabba c. & selvaggi g., 1997 crustal and deep seismicity in italy (30 years after), ann. geofis., 4400 (5), 981-993. ambrosetti p., basilici g., capasso barbato l., carboni m.g., di stefano g., esu d., gliozzi e., petronio c., sardella r. & squazzini e., 1995 i l pleistocene inferiore nel ramo sud-occidentale del bacino tiberino (umbria): aspetti litostratigrafici e biostratigrafici, il quaternario, 88 (1), 19-36. ambrosetti p., carboni m.g., conti m.a., costantini a., esu d., gandin a., girotti o., lazzaretto a., mozzanti r., nicosia u., parisi g. & sandrelli f., 1978 evoluzione paleogeografica e tettonica nei bacini tosco-umbro-laziali nel pliocene e nel pleistocene inferiore, mem. soc. geol. it., 1199,, 573580. ambrosetti p., carboni m.g., conti m.a., esu d., girotti o., la monica g. b., landini b. & parisi g. (1987) il pliocene e il pleistocene inferiore del bacino del fiume tevere nell’umbria meridionale, geogr. fis. dinam. quat., 1100, 10-33. ambrosetti p., carraro f., deiana g. & dramis f., 1982 i l sollevamento dell ’ i tal ia centrale tra i l pleistocene inferiore e il pleistocene medio, contributi conclusivi per la realizzazione della carta neotettonica d’italia, c.n.r. p.f.g. sottoprogetto “neotettonica”, parte ii, pubbl. 513, 219-223 argnani, a., bernini m., di dio g. m., papani g., & rogledi s., 1997 stratigraphic record of the crustal-scale tectonics in the quaternary of the northern apennines (italy), il quaternario, 1100, 597604. ascione a. & cinque a., 1999 tectonics and erosion in the long term relief history of the southern apennines (italy), z. geomorph. n. f., suppl. bd. 111188, 1-16. barberi f. & innocenti f., 1980 volcanisme neogene et quaternarie, in fagnani g. & zuffardi p. (eds), introduction a la géologie general d’italie et giude a l’excursion 122a, 26° congr. géol. intern., paris 1980, 99-104. barberi f., buonasorte g., cioni r., fiordelisi a., foresi l., iaccarino s., laurenzi m.a., sbrana a., vernia l. & villa i.m., 1994 evoluzione geologica dell’area geotermica tosco-laziale durante il pliopleistocene, mem. descr.carta geol. d’it., 4499, 77134. barbieri m., carrara c., castorina f., dai pra g., esu d., gliozzi e., paganin g. & sadori l., 1999 multidisciplinary study of middle-upper pleistocene deposits in a core from the piana pontina (central italy), giorn. geol., ser. 3, 6611, 4773. bellotti p., 1991 i sedimenti terrigeni della depressione lago del salto-tagliacozzo: considerazioni sulla loro successione verticale, studi geologici camerti, vol. spec. 1991/2, 111-114. bertini t. & bosi c., 1993 la tettonica quaternaria della conca di fossa (l’aquila), il quaternario, 66 (2), 293-314. bertotti g., cloetingh s., spadini g., podladchickov y. & picotti v., 1997 kinematics and dynamics of the fast continental rifting and passive margin formation in the tyrrhenian sea (mediterranean), abstract with programs, geol. soc. am. bull., 2299 (6), 317. bigazzi g., bonadonna f.p., centamore e., leone g., mozzi m., nisio s. & zanchetta g., 2000 new radiometric dating of volcanic ash layers in periadriatic foredeep basin system, italy, palaeogeo,. palaeoclima., palaeoecol., 115555, 327340. bigi s., calamita f., centamore e., deiana g., ridolfi m. & salvucci r., 1991 assetto strutturale e cronologia della deformazione della “zona d’incontro” tra le aree umbro-marchigiana e laziale-abruzzese (marche meridionali e lazio-abruzzo settentrionali), studi geologici camerti, vol. spec. (1991/2), 21-26. bigi s., cantalamessa g., centamore e., costa pisani p., d’ambrogi c., didaskalou p., micarelli a., nisio s. & potetti m., 2000 il plio-pleistocene della fascia abruzzese tra il f. tronto e il f. sangro, 88° riunione estiva della soc. geol. it., trieste, 6-8 sett. 2000, abstract, 75-76. bigi s., cantalamessa g., centamore e., didaskalou p., dramis f., farabollini p., gentili b., invernizzi c., micarelli a., nisio s., pambianchi g. & potetti m., 1995 la fascia periadriatica marchigiano-abruzzese dal pliocene medio ai tempi attuali: evoluzione tettonico-sedimentaria e geomorfologica, studi geologici camerti, vol. spec. (1995/1), 37-49. 84 e. centamore et al. bigi s., cantalamessa g., centamore e., didaskalou p., micarelli a., nisio s., pennesi t. & potetti m., 1997 the periadriatic basin (marche-abruzzi sector, central italy) during the plio-pleistocene, giorn. geol., ser. iii, vol. 5599/1-2, 245-259. blanc a.c., 1935 delle formazioni quaternarie di nettuno e loro correlazione con la stratigrafia dell’agro pontino, boll. soc. geol. it., 5544, 109-120. blanc a.c., 1936 una spiaggia a strombus bubonius presso palidoro (roma), rend. acc. naz. lincei, ser. 6, 2233, 200-204. blumetti a.m., coltorti m., ferreli l., michetti a.m., petronio c., raffy j. & sardella r., 1997 fucino basin, in: genti l i b. and dramis f. (eds.), geomorphology and quaternary evolution of central italy, guide for the excursion, fourth int. conf. on geomorphology, italy 1997, suppl. geogr. fis. dinam. quat., 33 (2), 79-103. bosi c. & messina p., 1991 ipotesi di correlazione fra successioni morfo-litostratigrafiche plio-pleistoceniche nell’appennino laziale-abruzzese, studi geologici camerti, vol. spec. (1991/2), 257-263. bossio a., costantini a., lazzaretto a., lotta d., mozzanti r., mazzei r., salvatorini g. & sandrelli f., 1993 rassegna delle conoscenze sulla stratigrafia del neoautoctono toscano, mem. soc. geol. it., 4499, 17-98. brancaccio l., pescatore t., sgrosso i. & scarpa r., 1984 geologia regionale, in t. pescatore (ed), lineamenti di geologia regionale e tecnica le aree colpite dal terremoto del 23 novembre 1980, formez, 1-47. brandi g.p., cerrina feroni a., decandia f.a., giannelli l., monteforti b. & salvatorini g., 1970 i l pliocene del bacino del tevere fra celleno (terni) e civita castellana (viterbo). stratigrafia ed evoluzione tettonica, atti soc. tosc. sci. nat., serie a, 7777, 308-326. buonasorte g., carboni m.g. & conti m.a., 1991 il substrato plio-pleistocenico delle vulcaniti sabatine: considerazioni stratigrafiche e paleoambientali, boll. soc. geol. it., 111100, 35-40. calamita f., coltorti m., deiana g., dramis f. & pambianchi g., 1982 neotectonic evolution and geomorphology of the cascia and norcia depression (umbria-marche apennines), geogr. fis. dinam. quat., 55, 263-276. calamita f., coltorti m., pieruccini p. & pizzi a., 1999 evoluzione strutturale e morfogenesi plio-quaternaria dell’appennino umbro-marchigiano tra il preappennino umbro e la costa adriatica, boll. soc. geol. it., 111188, 125-139. calderoni g., cilla g., dramis f. & farabollini p., 1996 dinamica fluviale olocenica nella media valle del fiume potenza (italia centrale), geogr. fis. dinam. quat., 1199, 19-28. cantalamessa g., centamore e., chiocchini u., colalongo m.l., micarelli a, nanni t., pasini g., potetti m., ricci lucchi f., cristallini c. & di lorito l., 1986 il plio-pleistocene delle marche, studi geologici camerti, vol. spec. “la geologia delle marche”, 61-81. cantalamessa g., centamore e., didaskalou p., micarelli a.,. napoleone g. & potetti m., 2002 elementi di correlazione nella successione marina plio-pleistocenica del bacino periadriatico marchigiano, studi geologici camerti, n. s., 11, 33-49. carboni m.g. & di bella l., 1996 la successione pleistocenica del sottosuolo di orte (lazio settentrionale), boll. soc. geol. it., 111155, 85-94. carboni m.g., 1975 biostratigrafia di alcuni affioramenti pliocenici del versante tirrenico dell’italia centrale, geologica romana, 1144, 63-85. carboni m.g., 1993 contributo alla stratigrafia del quaternario laziale, il quaternario, 66 (1), 27-34. carboni m.g., di bella l. & girotti o., 1993 nuovi dati sul pleistocene di valle ricca (monterotondo, roma), il quaternario, 66 (1), 39-48. carboni m.g., palagi i., palieri l., raffi r. & sposato a., 1994 dati preliminari sull’evoluzione geologica della fascia costiera tirrenica del lazio settentrionale durante il pliocene, mem. descr. carta geol. d’it., 4499, 177-188. carminati e., giunchi c., argnani a., sabadini r., & fernandez m., 1999 plio-quaternary vertical motion of the northern apennines: insights from dynamic modeling, tectonics, 1188, 703-718. carrara c., brunamonte f., ferreli l., lorenzoni p., margheriti l., michetti a.m., raglione m., rosati m. & serva l., 1992 i terrazzi della medio-bassa valle del f. velino, studi geologici camerti, vol. spec. 1992/1, 97-102. casto l. & zarlenga f., 1997 i beni culturali a carattere geologico del lazio: la pianura pontina, fondana e i monti ausoni meridionali, enea, dipartimento ambiente-regione lazio, assessorato alle politiche per la promozione della cultura, dello spettacolo, del turismo e dello sport, pp. 117. cavinato g. p. & de celles p. g., 1999 extensional basins in the tectonically bimodal central apennines fold-thrust belt, italy: response to corner flow above a subductiong slab in retrograde motion, geology, 2277 (10), 955-958. cavinato g.p., 1993 recent tectonic evolution of the quaternary deposits of the rieti basin (central apennines, italy): southern part, geologica romana, 2299,, 411-434. cavinato g.p., carusi c., dall’asta m., miccadei e. & piacentini t., 2002 sedimentary and tectonic evolution of plio-pleistocene alluvial and lacustrine deposits of fucino basin (central italy), sedimentary geology, 114488, 29-59. cavinato g.p., cerisola r. & storoni ridolfi s., 1987 segnalazione del ritrovamento di denti di equus stenonis (cocchi)in località s. rufina (conca di rieti lazio), gelogica romana, 2266, 255-261. cavinato g.p., cosentino d., de rita d., funiciello r. & parotto m., 1994 tectonic-sedimentary evolution of intrappenninic basins and correlation with the volcano-tectonic activity in central italy, mem. descr. carta geol. d’it., 4499, 63-76. centamore e. & micarelli a., 1991 stratigrafia, in minetti a., nanni t., perilli f., polonara l. & principi m. (eds), l’ambiente fisico delle marche, regione marche, selca, firenze, 1991, 5-58. centamore e. & nisio s., 2003 effects of uplift and tilting in the central northern apennines (italy), quaternary international, 110011--110022, 93-101. centamore e., cantalamessa g., micarelli a., potetti m. & ridolfi m., 1990 i depositi terrigeni di avanfos85elements to correlate marine and continental ... sa (messiniani-pliocene inferiore) dell’abruzzo settentrionale, mem. soc. geol. it., 4455, 563-568. centamore e., cantalamessa g., micarelli a., potetti m. berti d., bigi s., morelli c. & ridolfi m., 1991 stratigrafia e analisi di facies dei depositi del miocene e del pliocene inferiore dell’avanfossa marchigiano-abruzzese e delle zone limitrofe, studi geologici camerti, vol. spec. 1991/2, 125131. ciaranfi n., ghisetti f., guida m., iaccarino g., pieri p., rapisardi l., ricchetti g., torre m., tortorici l. & vezzani l., 1983 carta neotettonica dell’italia meridionale, pubbl. n° 515, cnr p.f. geodinamica, bari, 62 pp. cipollari p. & cosentino d., 1995 il sistema tirrenoappennino: segmentazione litosferica e propagazione del fronte compressivo, studi geologici camerti, vol. spec. 1995/2, 125-134. cipollari p., cosentino d. & gliozzi e., 1999 a extensionaland compressional-related basins in central italy during the messinian lago-mare event, tectonophysics, 331155, 163-185. cipollari p., cosentino d., esu d., girotti o., gliozzi e. & praturlon a., 1999 b thrust-top lacustrinelagoonal basin development in accretionary wedges: late messinian (lago-mare) episode in the central apennines (italy), palaeogeo., palaeoclima., palaeoecol., 115511, 149-166. colella a., de boer p. l. & nio s. d., 1987 sedimentology of a marine intermontane pleistocene gilberttype fan-delta complex in the crati basin, calabria, southern italy, sedimentology, 3344, 721-736. coltorti m., delitala m.c., dramis f., fornaseri m., nicoletti m. & paris e., 1987 k\ar datings of pyroclastites as a contribution to the geomorphological evolution of norcia and cascia tectonic depressions (central italy), terra cognita, 77 (2-3), 328. coltorti m. & dramis f., 1988 the significance of stratified slope-waste deposits in the quaternary of umbria-marche apennines, central italy, z. geomorph. n. f., suppl. bd. 7711, 59-70. coltorti m. & pieruccini p., 2000 a late lower pliocene planation surface across the italian peninsula: a key tool in neotectonic studies, j. geodynamics, 2299, 323-328. console r., di giovambattista r., favali p. & smriglio g., 1988 definizione delle strutture della costa adriatica attivate nelle sequenze sismiche del 1987, atti del 7° convegno gngts, roma, 1988, 519-529. d’agostino n., dramis f., funiciello r. & jackson j.a., 2001 interactions between mantle upwelling, drainage evolution and active normal faulting: an example from the central apennines (italy), geophysical j. inter., 114477, 475-497. dai pra g., 1995 geomorfologia e stratigrafia dei depositi del pleistocene e dell’olocene, in: lazio meridionale. sintesi delle ricerche geologiche multidisciplinari. enea, roma, 36-61. demangeot j., 1965 géomophologie des abruzzes adriatiques, mém. et doc. du c.n.r.s., paris, 287 pp. demangeot j., 1972 neotectonique et depots quaternaires dans l ’apennin, att i del convegno “moderne vedute sulla geologia dell’appennino”, acc. naz. lincei – quad. 118833, 215-233. di bella l., 1994 le associazioni a foraminiferi del plio-pleistocene della media e bassa valle del tevere. stratigrafia e paleoecologia, tesi di dottorato, “la sapienza” university, roma, pp. 309. dramis f., 1992 il ruolo dei sollevamenti tettonici a largo raggio nella genesi del rilievo appenninico, studi geologici camerti, vol. spec. 1992/1, 9-15. esu d., girotti o. & kotsakis t., 1991 molluschi e vertebrati di alcuni bacini continentali dell’appennino centrale: indicazioni biostratigrafiche e pealeoecologiche, studi geologici camerti, vol. spec. 1991/2, 295-299. faccenna c., funiciello f., giardino d. & lucente p., 2001 episodic back-arc extension during restricted manle convection in the central mediterranean, earth planetary sc. lett., 118877 (12), 105-116. faccenna c., funiciello r., bruni a., mattei m: & sagnotti l., 1994 evolution of a transfer-related basin: the ardea basin (latium, central italy), basin research, 66, 35-46. fazzini p., gelmini r., mantovani m.p. & pellegrini m., 1972 geologia dei monti della tolfa (lazio settentrionale; province di viterbo e roma), mem. soc. geol. it., 1111, 55-14. frepoli a. & amato a., 2000 spatial variation in stresses in peninsular italy and sicily from background seismicity, tectonophysics, 331177, 109-124. frezzotti m. & giraudi c., 1992 evoluzione geologica tardo-pleistocenica ed olocenica del conoide complesso di valle majelama (massiccio del velino, abruzzo), il quaternario, 55 (1), 33-50. galadini f. & messina p., 1994 plio-quaternary tectonics of the fucino basin and surrounding areas (central italy), giorn. geol., ser. iii, 5566 (2), 73-99. galadini f., 1999 pleistocene changes in the central apennine fault kinematics: a key to decipher active tectonics in central italy, tectonics, 1188 (5), 877894. gasparini c., riguzzi f. & tertulliani a., 1988 la sequenza sismica di porto san giorgio, atti del 7° convegno gngts, roma, 1988, 169-170. giraudi c., 1998 a alcuni dati per l’inquadramento cronologico delle fasi glaciali tardo-pleistoceniche dei monti greco e serra chiamano (abruzzo – italia centrale), il quaternario, 1111 (1), 115-120. giraudi c., 1998 b i laghi effimeri tardopleistocenici e olocenici di campo imperatore e del massiccio del gran sasso d’italia (abruzzo italia centrale), il quaternario, 1111 (2), 217-225. giraudi c., 2001 nuovi dati sull’evoluzione tardo-pleistocenica ed olocenica di campo felice (l’aquila abruzzo), il quaternario, 1144 (1), 47-54. girotti o. & piccardi e., 1994 linee di riva del pleistocene inferiore sul versante sinistro della media valle del f. tevere, il quaternario, 77 (2), 525-536. hearty p.j. & dai pra g., 1986 aminostratigraphy of quaternary marine deposits in the lazio region of central italy, z. geomorph. n. f., suppl. bd. 6622, 131-140. hippolyte j. c., angelier j. & roure f., 1994 a major geodynamic change revealed by quaternary 86 e. centamore et al. stress patterns in the southern apennines (italy), tectonophysics, 223300 (3-4), 199-210. horowits a., 1989 continous pollen diagrams for the last 3.5 m.y. from israel: vegetation, climate and correlation with the oxygen isotope record, palaeogeo., palaeoclima., palaeoecol., 7722,, 63-78. lavecchia g., brozzetti f., barchi m., menichetti m. & keller j. v. a., 1994 seismotectonic zoning in east-central italy deduced from an analysis of the neogene to present deformations and related stress fields, geol. soc. am. bull., 110066, 11071120. malatesta a. & zarlenga f., 1985 il quaternario di pomezia (roma) e la sua fauna marina, boll. soc. geol. it., 110044, 503-514. malinverno a. & ryan w. b. f., 1986 extension in the tyrrhenian sea and shortening in the apennines as results of arc migration driven by sinking of the lithosphere, tectonics, 55, 227-245 mantovani e., albarello d., tamburelli c. & babbucci d., 1996 evolution of the tyrrhenian basin and surrounding regions as a result of the africa-eurasia convergence, j. geodynamics, 2211 (1), 35-72. marcolini f., zanchetta g. & bonadonna f.p., 2000 some preliminary data on two small mammal bearing paleosols from the tyrrhenian and adriatic sides of italy, oryctos, 33, 85-94. marra f. & rosa c., 1995 stratigrafia e assetto geologico dell’area romana, mem. descr. carta geol. it., 5500, 49-112. michetti a.m. & serva l., 1990 new data on the seismotectonic potential of the leonessa fault area (rieti, central italy), rend. soc. geol. it., 1133, 3746. montone p. & mariucci m. t., 1999 active stress along the ne external margin of the apennines: the ferrara arc, northern italy, j. geodynamics, 2288, 251-265. moretti a., 1993 note sull’evoluzione tettono-stratigrafica del bacino crotonese dopo la fine del miocene, boll. soc. geol. it., 111122, 845-867. narcisi b., 1995 caratteristiche sedimentologiche, mineralogiche e geochimiche di un livello tufitico del pleistocene medio nei sedimenti nella piana del fucino, italia centrale, il quaternario, 88, 235238. negredo a. m., barba s., carminati e., saladini r. & giunchi c., 1999 contribution of numeric dynamic modelling to the understanding of the seismotectonic regime of the northern apennines, tectonophysics, 331155, 15-30. nisio s., 1997 evoluzione geologica e morfotettonica dell’area compresa tra il gran sasso ed il mare adriatico, geologica romana, 3333, 13-27. palieri l. & sposato a., 1988 segnalazione di fauna a strombus bubonius nell ’area compresa tra tarquinia e montalto di castro, il quaternario, 11, 161-166. parotto m. & praturlon a. (1975) geological summary of the central apennines, quad. la ricerca scientifica, 9900, 257-311. patacca e. & scandone p., 1989 post-tortonian mountain building in the apennines. the role of the passive sinking of a relic lithospheric slab, in boriani a., bonafede m, piccardo g. b. & vai g. b. (eds.): the lithosphere in italy, acc. naz. lincei, roma, 157-176. patacca e., sartori r. & scandone p., 1990 thyrrenian basin and apenninic arcs: kinematic relations since late tortonian times, mem. soc. geol. it., 4455, 425-451. radtke u., 1986 value and risk of radiometric dating of shorelines-geomorphological and geochronological investigations in cetral italy, eolian island and ustica (sicily), geomorph. n. f., 6622, 167-181. roveri m., bassetti m.a. and ricci lucchi f., 2001 the mediterranean messinian salinity crisis: an apennine foredeep perpective, sedimentary geology, 114411, 201-214. royden l., patacca e. & scandone p., 1987 segmentation and configuration of the subducted lithosphere in italy: an important control on the thrust belt and foredeep basin evolution, geology, 1155, 714-717. sevink j., remmelzwaal a. & spaargaren o.c., 1984 the soil of southern lazio and adjacent campania, enea rt/pas/84/10, 1-144. shackleton n.j., backman j., zimmerman h., kent d.y., hall m.a., roberts d.g., scnitker d., baldauf j.g., desprairies a., homringhausen r., huddlestun p., keene j.b., kaltenback a.j., krumsiek k.a.o., morton a.c., murray j.w. & westbergsmith j., 1984 oxygen isotope calibration of the onset of ice-rafting and history of glaciations in the north atlantic region, nature, 330077, 620623. testa g., 1995 upper miocene extensional tectonics and syn-rift sedimentation in the western sector of the volterra basin (tuscany, italy), studi geologici camerti, vol. spec. 1995/1, 617-630. tortorici l., monaco c., tansi c. & cocina o., 1995 recent and active tectonics in the calabrian arc (southern italy), tectonophysics, 224433, 37-55. zarlenga f., 1987 i depositi continentali del bacino del fucino (l’aquila, italia centrale), geologica romana, 2266, 223-253. 87elements to correlate marine and continental ... imp.nisio&scapola individuazione di aree a rischio sinkhole: nuovi casi di studio nel lazio meridionale stefania nisio1 & fabiana scapola2 1apatdipartimento difesa del suolo v. curtatone, 3 00185 roma. e-mail stefania.nisio@apat.it 2stage di formazione apat via littorio19, 03038 roccasecca (fr) riassunto: s. nisio & f. scapola, individuazione di aree a rischio sinkhole: nuovi casi di studio nel lazio meridionale. (it issn 03943356, 2005). distribuiti sul territorio italiano sono presenti molti laghetti di forma sub-circolare originatisi in epoca storica, le cui modalità di formazione, la morfologia e il contesto geologico-strutturale potrebbero essere compatibili con fenomenologie di piping sinkhole. tali laghetti presentano in genere diametro variabile da pochi metri al centinaio di metri e profondità fino ad un massimo di cinquanta metri. su alcuni si narrano leggende che ne farebbero risalire la formazione ad un evento catastrofico. la correlazione tra questi e gli sprofondamenti catastrofici, tipo piping sinkholes, è suggerita dall’osservazione del fenomeno più frequente dopo la formazione di un sinkhole: il processo di “annegamento” della cavità. nella maggior parte dei casi, infatti, le acque di infiltrazione si riversano all’interno della cavità di sprofondamento dandole la fisionomia di un piccolo lago di forma sub-circolare. in altri casi, invece, al fondo della cavità vi sono delle sorgenti che colmano rapidamente la voragine, nell’arco di pochi giorni, alimentandola perennemente. per alcuni fenomeni le ricerche effettuate hanno permesso di acquisire informazioni precise circa la data e le modalità di formazione, come è avvenuto per il lago di caira, nei pressi di cassino, di cui è stato possibile proporre una ipotesi genetica. il lago di caira, non noto sino ad oggi nella letteratura geologica, si è formato in seguito ad un evento calamitoso ed in maniera altrettanto repentina si è ricolmato, dopo circa due secoli. e’ stato possibile effettuare una ricostruzione accurata del contesto geologico, geomorfologico e idrogeologico al contorno nell’area di cassino-caira, e ricostruire la profondità del bedrock. la natura dello sprofondamento risulta compatibile con quella di un fenomeno di erosione dal basso, sinkhole s. s.; la cavità infatti si è originata in un’area di pianura al di sopra di una copertura continentale con spessori superiori a 100 metri. la scoperta della presenza del lago ha suscitato la necessità di indagare a fondo tutto il territorio del lazio meridionale, al fine individuare altri possibili episodi di deep piping. le ricerca hanno confermato che anche nelle aree limitrofe si sono manifestati in passato questi episodi calamitosi. e’ stato, inoltre, individuato un allineamento nne (faglia theodicea) lungo il quale si concentrano questi fenomeni. abstract: s. nisio & f. scapola, sinkhole prone areas: new study cases in southern lazio. (it issn 0394-3356, 2005). many sub-circular ponds in italian territory which originated in historical age, could be due to piping sinkhole phenomena. this hypothesis is supported by the geological, morphological and structural setting of the area affected by the sinkholes. the small lakes have diameters from a few, to hundreds of meters and a depth of up to fifty meters. the names are of dialectical origin and they usually indicate a kind of sinking. some legends refer the origin of the lakes to a quick catastrophic collapse. these depression are usually originated by karst erosion (collapse dolines) and the genetic process could sometimes be related to a deep piping process. the correlation between collapses and piping sinkholes is confirmed by the “drowning” of the cavity soon after the formation. groundwater fills the cavity creating a pond, sometimes with underwater springs that feed the small lake. the identification of a pond as sinkhole is not easy and needs specific studies such as geological surveys, geophysical, geochemical and hydrogeological studies. sometimes it is not possible to make an extensive field survey, due to costs, but it is just possible to suggest some hypotheses. the first step is to verify the geological and structural setting of the area, on the field and from the available literature. in some cases we have found a lot of information on, the date and the modalities of the cave genesis; for example the caira sink. the caira lake, unknown in geological literature, is formed by a collapse and after two centuries it is buried. information about this lake are preserved in few ancient documents in cassino mount abbey. geological, geomorphological and hydrogeological studies have been conducted. some first hypothesis are presented to explain the genesis of caira lake. the origin of the lake is compatible to sinkhole sensu stricto (or piping sinkhole); the lake is originated in a plain area over sedimentary cover (up 100 meters of thickness). after the discovery of the ancient lake, many areas of southern lazio have been investigated. the analysis of the aerial photographs has identified the location of many sinkhole ponds and paleoforms, in the same area. some of which at the present time are still the seat of the ponds and others are dry. from the historical sources the presence of other numerous lakes, now extinct and of difficult location have been verified. examining the concerned area we can conclude that some of these forms have originated from the sinkhole sensu stricto phenomenon. it has also been possible to determine the presence of a nne active fault system (theodicea fault), inside the intermontane basin of cassino, not known in literature. it is along this nne fault system that, in the past there was the distribution of almost all of the springs and/or ponds. at present the major sinkholes develop and align in this area. thanks to these discoveries, this area of southern lazio can be listed among the sinkhole prone risk areas. it is therefore necessary to accomplish a series of detailed technical enquiries before carrying out new infrastructures in order to protect the new constructions and above all human life. parole chiave: sinkhole, sprofondamento, deep piping, lazio meridionale, caira. keywords: sinkhole, sinking, deep piping, southern lazio, caira. il quaternario italian journal of quaternary sciences 18(2), 2005 223-239 224 s. nisio & f. scapola 1. area indagata e scopo del lavoro l’area oggetto di studio ricade nel territorio della provincia di frosinone, si estende per gran parte della valle latina procedendo da sora fino alla confluenza del fiume liri con il fiume gari (fig. 1). i siti indagati sono per lo più depressioni, piane alluvionali e conche intermontane, tutte di origine tettonica: la piana di sora, la conca di cassino, il bacino lirino ed altre piccole piane circondate da rilievi carbonatici. lo scopo del presente lavoro è quello di studiare la situazione geologico-strutturale, idrogeologica e geomorfologica nonché l’evoluzione storica del territorio e l’impatto antropico per individuare un’eventuale concomitanza di fattori predisponenti ed innescanti tale da determinare una reale potenzialità di rischio sprofondamento, sufficiente per classificare questo territorio come una “sinkhole prone area” (area a forte rischio sinkhole). a tal fine è risultato determinante il reperimento di alcune segnalazioni storiche (non note nella letteratura geologica) e l’individuazione di forme di sprofondamento attuali o relitte, per lo più coincidenti con cavità subcircolari, a volte obliterate, e con piccoli laghetti. in quest’area, infatti, sono state riconosciute alcune morfologie, di cui almeno due, rispettivamente presso l’abitato di caira e presso sora, riconducibili a fenomeni di sprofondamento repentino entrambe sedi di laghi oggi prosciugati: il lago di caira (che sarà l’oggetto principale di questa trattazione per la maggiore quantità di dati raccolti) ed il lago tremoletto, tra carnello e località s. domenico. tra gli altri specchi d’acqua rinvenuti meritano attenzione il lago di acquasanta e la polla magnesiaca. sono state individuate inoltre alcune paleoforme, con l’ausilio della fotointerpretazione, di cui solo ad alcune è stato possibile attribuire l’identità di cavità di sprofondamento o di sinkhole ponds, dopo la verifica sul terreno, (tra cui la pescarola, la cavità che ospita la sorgente magnesiaca e il laghetto di acquasanta), per altre, ormai, morfologicamente obliterate, non sono rimaste tracce neanche nella memoria storica degli abitanti e dei luoghi. 2. i fenomeni di sinkhole nel panorama italiano a differenza di numerosi altri eventi catastrofici generati da calamità naturali, fino a qualche decennio fa l’apertura di improvvise voragini nel territorio occupava un posto marginale nei programmi di protezione civile e di pianificazione territoriale. ultimamente, a causa della forte antropizzazione, il “rischio totale” associato al verificarsi di tali sprofondamenti è aumentato notevolmente fino al punto di suscitare l’attenzione non solo degli enti preposti alla tutela del territorio ma anche, di conseguenza, dell’intera comunità scientifica per un’azione di previsione e prevenzione degli stessi. il rischio associato all’innescarsi di dette fenomenologie è strettamente collegato non solo all’intensità e alla pericolosità dell’evento in sé, ma soprattutto alla corretta valutazione e determinazione degli “elementi” a rischio (vite umane, beni immobili, infrastrutture, strutture adibite a pubblico servizio e soccorso, beni culturali ecc). i sinkholes, forme di erosione che si inseriscono nell’ambito di processi di sprofondamento catastrofico, consistono in depressioni morfologiche sub circolari che si formano in seguito allo sprofondamento repentino di una porzione di terreno (fairbridge, 1968; monroe, 1970). il termine sinkhole spesso indica forme crateriche o pseudocrateriche omologhe ma generate ed evolute secondo modalità differenti. nella letteratura anglosassone il termine è sinonimo di dolina o di sprofondamento di origine antropica. in italia definisce forme di erosione dovute non solo a fenomeni carsici o gravitativi, ma anche forme più peculiari, che si formano in aree di pianura su grandi spessori di copertura sedimentaria, dovute all’interazione tra: risalita dal basso di fluidi di provenienza profonda, rocce carbonatiche, falde superficiali ed acque di infiltrazione meteorica, oscillazioni del livello di falda ed attività tettonica attiva e recente (nisio, 2003; nisio & salvati; 2004; nisio et al., 2004, 2005; ferreli et al., 2004). gli elementi che distinguono una dolina da un sinkhole in senso stretto sono le condizioni geologiche fig. 1 schema geologico dell’area e ubicazione di altri fenomeni, sinkhole pounds o paleoforme, individuati nell’area di cassino-s. eias. giorgio al liri (da devoto, 1965 modificato). location of the other phenomena recognized (sinkhole pounds o paleoform) in the cassinos.elia-s. giorgio area (from devoto, 1965 modified). al contorno, le modalità di innesco e di propagazione del fenomeno (salvati & sasowsky, 2002; nisio, 2003; nisio & salvati, 2004; nisio et al., 2004). la propagazione del processo si sviluppa, contrariamente a quanto avviene per le doline, dal basso verso l’alto fino a coinvolgere la copertura che si trova al di sopra del substrato carbonatico sottoposto alla dissoluzione carsica (per ulteriori approfondimenti si rimanda comunque a letteratura più specifica sull’argomento faccena et. al. 1993; tharp, 1999; berti et. al., 2002; regione toscana, 2002; salvati & sasowsky, 2002; nisio, 2003; nisio & salvati, 2004 etc.). i sinkholes s.s. si originano in contesti geologicostrutturali ed idrogeologici abbastanza articolati e complessi. zone ad elevato rischio sono le piane alluvionali e le conche intramontane in contatto con successioni carbonatiche, intensamente carsificate e tettonizzate (che ne costituiscano il bedrock), nelle quali vi sia la presenza concomitante di alcuni o tutti i fattori predisponenti e innescanti (faccenna et. al., 1993; capelli et. al. 2000; nisio, 2003; ferreli et. al., 2004). nella maggior parte dei casi finora individuati si è riscontrato che tali fenomeni tendono a concentrarsi in corrispondenza di aree caratterizzate da un’abbondante circolazione d’acqua, ove sono presenti acquiferi imprigionati in substrati profondi per lo più ricoperti da sedimenti impermeabili o scarsamente permeabili ed entrambi interessati da sistemi di faglie. quest’ultimi mettono in comunicazione idrica i due mezzi favorendo processi di sifonamento, suffosione profonda (deep piping) ed erosione preferenziale, specialmente nella zona di interfaccia (littlefield et. al., 1984; derbyshire & mellors, 1988; billiard et. al., 1992; nisio, 2003; nisio et al., 2005). i processi di deep piping rivestono un ruolo fondamentale nell’origine dei sinkhole s.s. per tale motivo a questi è stato dato anche il nome di piping sinkhole o meglio deep piping sinkhole (nisio, 2003; nisio & salvati, 2004; nisio et. al. 2004; 2005; graciotti et. al. 2004). molte aree dell’appennino centro-settentrionale e meridionale sono interessate da questi fenomeni; triste primato spetta proprio alla regione lazio, in cui gli sprofondamenti risultano concentrati in conche intramontane (ad es. la piana di s. vittorino, rieti), in strette valli fluviali (es. valle del f. s. martino, capena), in piane costiere (es. pianura pontina), nonché in depressioni e fasce pedemontane di aree vulcaniche (faccenna et. al., 1993; bono, 1995; di loreto et. al. 1999; capelli et. al. 2000; ciotoli et. al., 2001; colombi et al., 2001; bersani & castellano, 2002; nisio, 2003; annunziatellis et. al., 2004; del prete et. al., 2004; graciotti et. al., 2004). inoltre su molte piane del territorio italiano, soprattutto in appennino, sono presenti piccoli laghi, polle o fosse di forma circolare (craterica o pseudo-craterica) di dubbia origine che potrebbero essere compatibili con tali fenomeni (caramanna et. al., 2004; del prete et. al., 2004; nisio et. al. 2005). molti fenomeni di sinkholes sono stati segnalati nelle vicinanze dell’area di studio, in un raggio di circa 100 km: sul versante sud-orientale del roccamonfina, e nella valle del f. volturno, presso il confine lazio-campania (del prete et. al., 2004); presso posta-fibreno (frosinone; agrillo et. al., 2004), nelle vicinanze di atina (saroli et. al., 2004); nonché più a sud in pianura pontina (norma225individuazione di aree a rischio ... sermoneta-sezze; bono, 1995; colombi et. al. 2001; di filippo et. al., 2002; nisio, 2003; campobasso et. al., 2004). fenomenologie di sinkhole non erano prima d’ora state segnalate nell’area del cassinate. 3. inquadramento geologico–strutturale le aree di pianura in studio ricadono nel lazio meridionale, coincidono con le piane di cassino e sora e con una parte della piana alluvionale del lirigarigliano, alle pendici di alcune dorsali carbonatiche tra cui quella di monte cairo (provincia di frosinone; fig. 1). dopo la tettonica compressiva, che ha portato alla costruzione dell’edificio a thrust, una fase estensionale ha prodotto in quest’area una rete di faglie normali ad alto angolo, immergenti, generalmente, verso ovest, molte delle quali riattivano i vecchi piani di thrust sepolti (ghisetti & vezzani, 1999; cavinato & de celles, 1999). si impostano, nel versante sudovest della catena, numerosi bacini estensionali, tra cui il bacino di sora, con una geometria ad half-graben delimitati dalle suddette faglie, ripetutamente riattivate durante il pliocene sup.pleistocene, con rigetti, per le strutture maggiori, fino a uno/due chilometri (ghisetti et. al., 2001). i bacini, colmati da sedimenti di syn-rift dal miocene sup. al pleistocene inferiore, presentano un’orientazione nnw-sse e nw-se; altri, di dimensioni minori, a direzione ne-sw o n-s (tra cui il bacino di cassino), si sono sviluppati come strutture trasversali (mattei et. al., 1994). durante il pleistocene l’area emerge ed una fase tettonica distensiva genera bacini interni fluvio-lacustri con connesse manifestazioni vulcaniche (roccamonfina), controllati da strutture appenniniche ed antiappenniniche. nel pleistocene medio si verifica una nuova fase distensiva che porta all’estinzione dei bacini lacustri, alla formazione di nuove conche interne e alle attuali morfostrutture. dal pleistocene superiore è attiva una tettonica tipo strike-slip che ha dato localmente origine a piccoli bacini tipo pull-apart, sorgenti termominerali, deposizione di travertini e caratteristiche vulcano-tettoniche (faccenna, 1994; mattei et. al., 1994). in questo contesto si è formato il “bacino lirino” che è stato colmato da depositi lacustro-alluvionali (con spessori di oltre 100 m) posti in contatto tettonico con la successione carbonatica mesozoica che costituisce l’ossatura del massiccio affiorante. esso si estende nell’ambito delle province di frosinone e di caserta, presenta una direttrice morfostrutturale nw-se, fra la catena dei monti aurunci (a sud-ovest) e la catena dei monti simbruini-monte cairo (a nord-est), a confine fra l’appennino centrale e quello meridionale. la nascita e lo sviluppo del bacino lirino sono stati, fin dai primi studi, attribuiti sia all’attività di sistemi di faglie appenniniche, a carattere prevalentemente distensivo con notevoli rigetti verticali, che al sorgere dell’edificio vulcanico del roccamonfina (devoto, 1965; damiani & panuzzi, 1980, 1982; cavinato et. al., 1995). all’interno di quest’area si distinguono tre sistemi di faglie principali: n-s, nw-se ed e-w. le faglie che ne bordano il margine nord-orientale, ai piedi sia di 226 monte cairo che dei monti di venafro, sono normali ad alto angolo; mentre la linea tettonica che borda il margine sud-occidentale, fra pico, esperia e m.te fammera, è un piano di faglia inverso (un sovrascorrimento) a direzione nw-se immergente verso sud, a basso angolo (cerisola & montone, 1992). i rilevamenti hanno messo in luce l’esistenza di un terzo elemento tettonico di importanza probabilmente “regionale” (confermato anche dal confronto dei dati di rilevamento con i sondaggi geognostici reperiti), qui definito faglia theodicea (passante presso s. angelo in theodice; fig. 1). osservazioni geomorfologiche, strutturali e stratigrafiche, accompagnate da indagini geofisiche, suggeriscono una ripartizione del bacino lirino in due settori, uno occidentale (ad ovest del fiume gari) caratterizzato da un regime estensionale a direzione prevalentemente ne-sw ed uno orientale caratterizzato da un regime sempre estensionale ma a direzione prevalentemente wnw-ese. la faglia theodicea, a direzione nne, potrebbe servire da svincolo fra questi due settori a mobilità diversa e, quindi, non si possono escludere movimenti trascorrenti lungo la stessa. i settori orientali in prossimità del fiume gari sono ribassati, rispetto a quelli occidentali, dall’attività del sistema nne più giovane rispetto a quello wnw e nw. la piana di cassino-caira a nord-est è delimitata dalla faglia della marsica, che interessa i monti di venafro e monte cifalco, ad ovest dalla faglia theodicea (nne) e a sud dall’allineamento monte trocchio-monte porchio, che sembra essere una prosecuzione sud-orientale della faglia che mette in contatto monte cairo con i sedimenti lacustri ed alluvionali che colmano la valle latina (accordi, 1964; parlotto, 1970; 1971; parlotto & praturlon, 1975; 1981). questo forte controllo tettonico e l’intensità delle deformazioni fragili ad esso associate hanno provocato un’intensa disarticolazione del substrato carbonatico (cerisola & montone, 1992). in effetti dai numerosi dati di pozzo si nota che la profondità del bedrock varia, anche in aree ristrette, da poche decine di metri dal piano di campagna, nei pressi della dorsale carbonatica, fino a diverse centinaia di metri al centro della piana. le unità litostratigrafiche, che formano i rilievi carbonatici presenti nell’area (m. cairo m. cifalco m. ausoni-aurunci rilievo settentrionale di m. massico), vengono collocate nel dominio di piattaforma lazialeabruzzese (accordi et. al.,1988) a cui si sovrappongono sedimenti terrigeni. al di sopra dei depositi marini e continentali, già morfologicamente modellati, di età plio-pleistocenica poggiano i sedimenti lacustri lirini. l’intera sequenza stratigrafica lacustre, non ancora conosciuta nei dettagli; presenta uno spessore complessivo di cento metri circa. dal punto di vista stratigrafico devoto (1965) suddivide la suddetta successione in tre formazioni principali che sono, dal basso verso l’alto, il limo lacustre inferiore, la facies lacustre normale e la facies lacustre tardiva. a queste l’autore aggiungeva, oltre ai travertini tipici, le facies vulcaniche rappresentate dalle tufiti di vandra, dai tufi cineritici e dai tufi rimaneggiati di san vittore (fig. 1). il limo lacustre inferiore presenta grande uniformità, è composto da limi calcarei molto puri, a giacitura orizzontale, ad alto tenore in caco3 (circa l’80/90%) regolarmente intercalati da numerosi livelli, a spessore variabile, di prodotti vulcanici. lo spessore totale affiorante è di circa 25-30 m. la facies lacustre normale è la più rappresentativa dei depositi lacustri lirini, complessivamente è costituita da un 60% di ghiaia-sabbia, da un 30% di limi calcarei e per il restante 10% da altre tipologie di sedimenti, presenta una significativa varietà di litofacies ed un’estrema variabilità del contenuto in caco3 che oscilla fra il 20% ed il 98%. la facies lacustre tardiva è composta prevalentemente da limi calcareo-argillosi, da limo torboso, da sabbie calcaree, da travertini incoerenti e da travertini porosi inglobanti resti vegetali palustri. significative sono le variazioni delle percentuali di sabbia e di argilla nei singoli strati. la deposizione del travertino tipico (che affiora solo in alcuni punti della piana; carrara, 1991) è connessa con l’attività di sorgenti fortemente incrostanti ad elevato tenore in ca++ e mg++ alcune delle quali sono tuttora attive (capo d’acqua). i principali sistemi di faglie che hanno interessato l’area sono due: il primo sistema presenta allineamento nw-se a cui sono collegate le placche di travertino presenti fra aquino – cassino, ed il secondo, orientato circa n-s o nne-ssw alla cui attività vengono attribuiti sia gli affioramenti rinvenuti presso la direttrice pontecorvo-aquino che quelli lungo il corso del fiume gari in s. angelo in theodice. benché le bancate di travertino si ritrovino in maniera frammentaria in tutta l’area, si è ipotizzata l’esistenza, su base morfologica, di un solo grande affioramento il cui spessore raggiunge i 18m. di norma i travertini tipici seguono o sono incassati nei sedimenti lacustri del lago lirino mentre, lungo il margine nord-orientale, poggiano sulla sequenza carbonatica della piattaforma laziale – abruzzese. da un punto di vista composizionale la litofacies, per lo più vacuolare, è caratterizzata da alternanze di sabbie e limi calcarei, contenenti litotipi autoctoni micro e fitotermali associati a facies stromatolitiche e bibliolitiche. di frequente dal travertino litoide si passa a quello spugnoso ed incoerente. al di sopra dei sedimenti lacustri affiorano, per lo più, alluvioni antiche e recenti, detriti di falda e/o di versante e terre rosse. riportiamo, qui di seguito, una colonna stratigrafica “tipo” per la piana di cassino, ricordando comunque che la profondità del substrato carbonatico oscilla notevolmente fra il piano campagna ed i 150 m, allontanandosi dai bordi verso il centro della piana (i dati sono stati riassunti nelle stratigrafie di fig. 7b): 0/4 m terreno vegetale; 4/15 m grosse alternanze di limo con argilla, sabbia e sabbia con ghiaia; 15 m/15,5 m ghiaia grossolana; 15,5 m/16,7 m limo poco argilloso, grigio chiaro; 16,7 m/17,0 m ghiaia grossolana; 17,0 m/ 18,5 m: limo con argilla, bruno; 18,5 m/22,0 m: sabbia media grossolana; 22,0 m/23,4 m: limo argilloso e sabbioso con poca ghiaia minuta, grigio; 23,4 m/43,5 m: limo con argilla, da grigio scuro a bruno (prelevato campione indisturbato c1 a 26m); 43,5 m/48,0 m: limo poco argilloso con tracce di sabbia fine, grigio chiaro; 48,0 m/51,5 m: limo poco argilloso con tracce di sabbia fine, grigio (prelevato campione indisturbato c2 s. nisio & f. scapola 227 a 50m); 51,5 m/60,5 m: limo con argilla, grigio; 60,5 m/67,8 m: limo argilloso, debolmente organico, con elementi di ghiaia, da grigio scuro a bruno; 67,8 m/103 m (fondo foro): calcari biancastri. 3.1 sismicità dell’area nella zona di montecassino si sono sempre verificati fenomeni particolari (“i terremoti locali di montecassino”) che turbavano molto sia gli abitanti che i monaci della badia. questi ultimi, non sapendo dare una spiegazione scientifica del fenomeno, si limitarono a riportare fedelmente la descrizione. la cronistoria “sismica” di montecassino, registrata dai monaci della abbazia, inizia nel 1005 e, tranne qualche piccola lacuna, giunge fino al 1920. dal 1005 al 1887 si registrarono ben 453 terremoti ma, nel 1920, sacchetti annotava che “la quasi totalità dei terremoti subiti rimase circoscritta a montecassino e solo raramente fu avvertita a cassino”. i monaci chiesero al re di napoli, ferdinando ii di borbone, di far studiare da un geologo del regno le cause dei tremori ai quali si associava un odore di zolfo. il re, nel 1837, incaricò leopoldo pilla che imputò i terremoti a fattori “locali” e li ascrisse a cause elettriche. de marco, invece, nel 1888, arriva alla conclusione che tali scosse sono imputabili a crolli dovuti all’azione aggressiva delle acque sotterranee. sacchetti (1920) sostenne la tesi di de marco riportando, a supporto della stessa il “terremoto che nel 1724 si verificò“al paesello di cairo” (data coincidente con la formazione del lago di caira) e precisando che non si trattò di una vera e propria scossa sismica. gli episodi descritti sono in definitiva da ricollegare ai fenomeni carsici presenti sulla dorsale di monte cairo che portano alla frequente formazione di doline di crollo e all’allargamento di cavità ipogee, processo peraltro molto spinto ed ancora visibilmente in atto. l’area in esame tuttavia è stata colpita da diversi sismi di forte intensità (istituto nazionale di geofisica, 2000). in particolare la zona compresa fra la valle latina e il confine con la campania (da sora al vulcano di roccamonfina) appare decisamente attiva soprattutto per l’elevata frequenza degli eventi registrati, con un addensamento anomalo proprio in corrispondenza del territorio di cassino. (gasparini et. al., 1985; frezzotti et. al., 1988; frepoli & amato, 2000). l’area con elevato risentimento è allungata lungo la direzione nw-se. tra gli eventi della sismicità storica dell’area si ricorda quello del 9 settembre del 1349 che colpì il cassinate ed il territorio di isernia (a cassino il risentimento è stato del ix grado), quello del giugno 848 nel sannio occidentale, quello del 23 luglio del 1654 nell’area sorano-marsicana che provocò la completa distruzione delle località di piedimonte san germano alta, posta fibreno e santopadre, ed infine l’evento del 6 dicembre 1874 dei monti della meta. nel 1724 si verificarono solo due scosse nei mesi di settembre e ottobre. tra gli eventi sismici recenti, i più significativi sono: un evento del 1973 (di magnitudo 4.4 localizzato a 5 km di profondità), un evento del 1980 (di magnitudo 3.5 con ipocentro a 8 km di profondità) e i due terremoti del 7 e del 11 maggio del 1984 che colpirono l’area compresa tra l’alta valle del sangro, san donato in val di comino ed i monti della meta, di magnitudo mb 5.5 e 5.3, rispettivamente. i danni del sisma si riscontrano nell’area di studio lungo l’allineamento rappresentato dalla faglia theodicea (su cui è ubicato il sinkhole di caira); il piezometro ubicato nella villa comunale di cassino (distante circa 1.5 km dal lago di caira sul medesimo allineamento) si abbassò di molti centimetri ulteriori eventi sismici sono stati registrati nel giugno e nel settembre1994, e gli effetti si registrano anche sugli allineamenti in direzione n-s (frepoli & amato, 2000). inoltre scosse strumentali registrate tra il 2003 e il 2004 nell’area di cassino hanno determinato abbassamento del suolo (registrato presso un piezometro) di circa 3 centimetri a poca distanza dal lago di caira, e lungo l’allineamento nne di cui si è parlato in precedenza. ultimamente l’istituto nazionale di geofisica e vulcanologia ha rilevato, durante il monitoraggio della rete sismica nazionale centralizzata, il verificarsi di un periodo sismico. tali eventi sismici avvertiti dalla popolazione locale e, peraltro, segnalati alla protezione civile, presentano profondità ipocentrale molto superficiale dando luogo a boati e a risentimenti macrosismici molto localizzati. 4. evoluzione geomorfologica nel pliocene la porzione sud-orientale dell’odierna valle latina era interessata da una sedimentazione caratteristica di ambiente marino costiero e doveva presentarsi come un golfo aperto in direzione ese fino al pliocene medio-superiore, (fig. 2). durante la fase regressiva le acque lasciarono definitivamente l’area compresa fra le dorsali carbonatiche. il rapido abbassamento del livello del mare dovette incidere profondamente sull’organizzazione dei reticoli idrografici preesistenti ed il settore appena emerso divenne una valle fluviale sbarrata in seguito alla costruzione del vulcano di roccamonfina. nel pleistocene medio iniziò la raccolta delle acque del lago lirino (devoto, 1965). l’aumento del carico sedimentario con l’erosione della soglia operata dall’emissario (l’attuale garigliano), hanno fatto del lago lirino un lago precocemente fossile. infatti, dato il continuo sollevamento a cui è stata soggetta quest’area, gli immissari furono costretti ad operare un continuo “ringiovanimento” del loro profilo d’equilibrio; cosa che determinò un apporto talmente massivo di sedimenti da ottenere, come effetto, il rapido colmamento del bacino stesso. l’età di estinzione del sistema lacustre lirino potrebbe essere avvenuta 368 ka (evernden e curtis; 1965) o 354±7 ed i 359±7 ka (narcisi; 1986). terminato il ciclo lacustre il principale agente morfologico divenne quello fluviale; ai sedimenti “lirini” si sovrapposero i depositi alluvionali. l’ultimo ordine di terrazzi, post-würmiano, si situa a pochi metri dall’attuale letto del liri. la piana di cassino presenta versanti regolarizzati ad est ed ad ovest ed è orlata, nel margine settentrionale, da piccole conche intermontane la cui genesi è strettamente collegata alla presenza ed alla attività di elementi strutturali il più delle volte a direzione ns. il massiccio carbonatico affiorante, oltre ad essere visibilmente fratturato e tettonizzato, presentandosi a luoghi pulverulento, è anche intensamente carsificato. individuazione di aree a rischio ... 228 presso monte cairo-monte cassino è emersa la presenza di numerose doline per crollo o dissoluzione (di grande diametro) la cui distribuzione sembra ricalcare l’andamento delle faglie principali. all’interno della conca si individuano numerose conoidi detritiche a ventaglio di notevoli dimensioni, disposte prevalentemente lungo la faglia della marsica e, subordinatamente, lungo la faglia theodicea (in località caira). anche il reticolo idrografico e la distribuzione delle sorgenti risentono del controllo tettonico. e’ evidente in quest’area la regolarizzazione di tratti o di intere aste fluviali (ad es.fiume rapido e parte del fiume gari) che assumono un andamento circa ns ricalcando l’andamento della faglia theodicea. la ricostruzione della rete di drenaggio superficiale, ordinata secondo i l metodo di strahler (1954), ha permesso di ricavare indizi morfotettonici: anomalia significativa è rappresentata dalle aste dei primi ordini che tendono ad assumere un’orientazione preferenziale nw-se, tale distribuzione ha un addensamento in corrispondenza della diagonale nw-se tracciabile fra la confluenza del fiume liri con il fiume gari e massoneria di folco (aquino). anche le forme d’aquino presentano in quest’area una rettizzazione nw-se, preceduta da una “cattura a gomito”, del loro corso. questi indizi, associati alla constatazione che tale direttrice funge anche da spartiacque fra il settore nordorientale e quello sudoccidentale, fanno pensare alla presenza di una faglia sepolta avente la medesima orientazione. in effetti le aste dei primi ordini, essendo le più “giovani” non sono controllate dalle “vecchie direttrici tettoniche” ma da quelle recenti e/o attuali. l’azione della tettonica è altresì testimoniata dalla presenza di forme strutturali sui versanti quali: faccette triangolari, depressioni, selle e interruzione di linee di cresta. 5. risorse idriche dell’area: studi sulla migrazione e sulla variazione di portata delle sorgenti l’area in studio è caratterizzata da un abbondante flusso di acque sia superficial i che profonde. quest’ultime vanno ad alimentare, in maniera considerevole, le portate dei corsi principali. l’unità idrogeologica, che dà origine alle sorgenti del gari, appartiene a quella più grande, costituita dai monti ernici, dai monti simbruini e da monte caira, e ne rappresenta la terminazione meridionale a partire dal fiume cosa (baj & tartaglia, 1973; boni, 1973; mounton, 1973; celico; 1976; celico & stanganelli, 1976; boni et al., 1986). a sud della linea del cosa sono presenti altri due punti di sfioro della falda che costituiscono, rispettivamente, le sorgenti di capodacqua d’aquino e di bucone (fig. 3). le prime sono legate alla discontinuità tettonica della valle del melfa, le seconde all’innalzamento del complesso dolomitico in corrispondenza di monte cairo. caratteristica non trascurabile delle sorgenti bucone è che esse sono costituite da due polle, una sulfurea a circuito lento e profondo e l’altra non sulfurea a ricambio veloce. le sorgenti presenti nell’area di cassino possono essere raggruppate in tre gruppi principali: il gruppo pedemontano, il gruppo delle terme varroniane ed il gruppo mastronardi (fig. 3) con valori di portata cumulati pari a 18m3/sec. le acque di tali sorgenti confluiscono nel fiume gari incrementandone la portata. la conca di cassino è attraversata dal fiume rapido (che presenta portata media di 2.5 m3/sec) nelle cui acque vanno a confluire i torrenti che attraversano il territorio di cassino-caira fra cui ricordiamo il torrente calcara, il torrente del campo, il fosso della grotta ed il fosso di caira. il rapido si immette nel gari in prossimità del gruppo mastronardi (fig. 3). le sorgenti presenti nel territorio di cassino (s.l.) sono numerose e con elevata portata. durante il corso della storia esse hanno subito variazioni per numero, ubicazione e chimismo (varrone, 1954). attualmente è diminuito il numero delle sorgenti minerali la cui presenza ed azione massiva nei tempi passati sono testimoniate litilogicamente dalle bancate di travertino, che occupano gran parte della piana, e documentate da numerose fonti storiche e bibliografiche. la maggior parte delle sorgenti minerali sgorgava fra valle faga e suio, ma ve ne erano diverse anche nel territorio di cassino nei pressi della badia, in località s onofrio ed anche in località fontanelle (fra il colosseo e la cappella di santa scolastica). in particolare in località fig 2 ricostruzione paleogeografica dell’area. paleo-geographic reconstruction of the study area. s. nisio & f. scapola fontanelle erano presenti due polle, una d’acqua sulfurea e l’altra ferruginosa con temperatura di 15°c (sacchetti 1920). queste polle minerali rappresentavano ciò che rimaneva di una serie più numerosa che fino al secolo decimo ottavo alimentava il ramo del fiume rapido (gattola 1734); fra queste ricordiamo le due sorgenti presenti nei pressi del lago di caira; fig. 3). il numero delle sorgenti d’acqua dolce era numeroso ed imprecisato (pilla, 1815), si pensi che nel 1902 del foco ne elenca più di quaranta per il solo centro abitato. la distribuzione delle sorgenti sul territorio non sembra casuale ma si individuano allineamenti lungo direttrici tettoniche ben precise. quelle sulfuree (gattola; 1734) si disponevano lungo il corso del rapido (dove lo stesso assume un andamento circa ns) ricalcando la direttrice della faglia theodicea. devoto (1965) descrive l’attività di sorgenti fortemente incrostanti ad elevato tenore in ca++ e mg++ (ad esempio quelle di capo d’acqua) la cui disposizione coincide con l’andamento dei principali sistemi di faglie: il primo ad andamento nw-se, a cui sono collegate le placche di travertino presenti fra aquino e cassino, ed un altro orientato circa n-s o nne-ssw, alla cui attività vengono attribuiti sia gli affioramenti rinvenuti presso la direttrice pontecorvo-aquino che quelli lungo il corso del fiume gari in s. angelo in theodice. un’ultima annotazione riguarda la migrazione delle sorgenti sulfuree che si sono spostate progressivamente dai settori se (cassino, sant’angelo), prossimi all’apparato del roccamonfina, verso quelli nw (isola liri, ceprano) ove attualmente si assiste a periodiche manifestazioni sulfuree. tale migrazione di sorgenti è stata accompagnata da un abbassamento delle vecchie linee sorgentizie, in località caira, di almeno cinquanta metri e da oscillazioni continue del livello di falda. oltre alle probabili cause naturali la spiegazione del fenomeno va ricercata anche in quelle antropiche: quest’area è sottoposta a continui emungimenti (per portate “dichiarate” di 3m3/sec, ma sicuramente più cospicue), resi più intensi negli ultimi 20 anni. tale captazione di acque sotterranee, in un’area prossima alla confluenza del rapido con il gari, aveva avuto approvazione per portate di 6m3/sec. fra l’agosto del 1986 ed il settembre dell’87, a seguito dell’emungimento di 1,5m3/sec si registrarono nel territorio di cassino continui “assestamenti” accompagnati da tremori, alcune sorgenti si estinsero, altre diminuirono notevolmente la loro portata ma, cosa più grave, si verificò la subsidenza di una vasta area e vennero denunciate lesioni a diversi manufatti. dopo perizie tecniche e studi congiunti, le autorità dichiararono che per portate pari a 3m3/sec non ci sarebbero stati risentimenti o rischi significativi per il territorio; tali dati risultarono dagli accertamenti delle condizioni geologico-strutturali al contorno ed dai parametri geotecnici dei terreni analizzati. 5.1 le falde della piana di cassino nei sedimenti di copertura della piana di cassino, caratterizzati dall’alternanza di orizzonti per lo più impermeabil i (argil le o l imi argil losi) con altr i a media/alta permeabilità (sabbie grossolane e ghiaie), si rinvengono falde sovrapposte (riscontrate a 25 m e a 40 m di profondità negli strati a buona permeabilità orizzontale). la stessa successione quaternaria, presentando una quasi totale impermeabilità verticale, permette la presenza, nel substrato carbonatico, di un acquifero confinato o falda in pressione. le connessioni idrauliche tra la falda profonda e le diverse falde superficiali avvengono, per lo più, attraverso strati limoso-sabbiosi, a luoghi ghiaiosi, a bassa trasmissività. solo localmente e in aree ristrette, la falda profonda è direttamente in comunicazione con quella superficiale. questo è possibile per la presenza di depositi grossolani posti o al tetto dell’acquifero calcareo o intercalati nei sedimenti fluvio lacustri. connessione tra la falda profonda e quella superficiale è possibile per la presenza di importanti dislocazioni tettoniche (quali la faglia theodicea per esempio), che attraversano sia il substrato che le coperture quaternarie, accompagnate da un reticolo di ripetizioni, di fratture o diaclasi, che mettono in comunicazione il mezzo permeabile carbonatico profondo con quello impermeabile di superficie. 5.2 caratteristiche geotecniche dei terreni di copertura le analisi di due campioni (c1, a 26 m dal p.c, e c2 , a 46 m del pozzo 1, fig 7b) mostrano che i terreni lacustri recenti della piana di cassino sono formati in massima parte da terreni coesivi inorganici (limo con argilla, argilla con limo e limo argilloso) e in minima parte da intercalazioni e lenti di terreni non coesivi (ghiaie più o meno sabbiose e sabbie). fra i terreni coesivi prevalgono le argille inorganiche di 229 fig. 3 schema idrogeologico semplificato dell’area di cassino. ubicazione dei principali gruppi di sorgenti e relative portate.. simplified hydrogeological scheme of the cassino area. location of the main springs groups in the cassino area. individuazione di aree a rischio ... elevata plasticità, seguite in ordine decrescente da limi di medio-bassa plasticità. il contenuto d’acqua del terreno varia generalmente tra il 20% e il 50%. il peso di volume allo stato naturale è in generale compreso tra 1,7 e 2 g/cm3, con valori medi che tendono ad addensarsi intorno a 1,0 g/cm3. i valori medi tra w0 e γ non mostrano alcuna tendenza a variare con la profondità. la coesione non drenata è risultata per entrambi i campioni più elevata di quanto non fosse lecito aspettarsi in base alle ben note correlazioni sperimentali con l’indice di plasticità e con la pressione di consolidazione: fatto questo che starebbe ad indicare un certo grado di consolidazione nei depositi in esame, confermato, tra l’altro, anche dalle prove edometriche. 6. i fenomeni di sprofondamento nel lazio meridionale dall’analisi storica, effettuata presso gli archivi di alcune abbazie e presso biblioteche specialistiche, è emerso che l’area della provincia di frosinone coincidente con le antiche proprietà benedettine prendeva il nome, agli inizi del 1800, di terra dei laghi. ciò per la presenza di una serie di laghetti fra cui ricordiamo: lacus raedemprandi; lacus sapatini; lacus maiore (presso aquino) già presenti nel 1734; lacus de pobilu in area non precisata sulla linea di confine con il territorio di venafro all’interno delle proprietà benedettine; lacus vitecosum; lacus acquafondata (presso viticuso e venafro; jandolo, 1966). altri numerosi laghi, oggi scomparsi, sono emersi dall’analisi toponomastica dell’area in studio, consultando gli atti di compravendita delle proprietà benedettine, relative al periodo 16001800 (leccisotti & avigliano, 1977): la cisterna, la cisternola, pescorile, lo lago, lago di sotto, acqua nera nei pressi di s. elia fiumerapido; le pantane nel territorio di cervaro; lo lacozzo, la pescarola, le pescie, la puzza e caput casini (nelle vicinanze della chiesa di s. pietro), lo lacozzo, lo lago, lo pantano, presso san germano (attuale cassino); le pantanella presso l’abitato di piumarola nella valle del liri. della maggior parte di tali laghi oggi non vi è più traccia, fatta eccezione per la pescarola, in località masseria chiusavecchio. la ricerca storica, pertanto, è stata volta alla possibile ubicazione di tali laghetti e al censimento di eventuali cavità sub-circolari che potrebbero far ipotizzare episodi di sprofondamento del terreno (fig. 4). i documenti storici, unitamente alla fotointerpretazione hanno così portato all’individuazione di una serie di specchi d’acqua e di possibili morfologie depresse nelle aree di pianura: laghetti, piccole polle, con caratteristica forma sub-circolare, cavità asciutte relitte, che si rinvengono al centro di piane alluvionali o conche intermontane, privi di immissario o emissario, e che non possono essere attribuiti ad attività antropiche e/o a fenomeni carsici in senso stretto. la conferma dell’esistenza di tali fenomeni è avvenuta con il reperimento della documentazione storica riguardante la formazione di un lago oggi estinto: il lago di caira. 6.1 il lago di caira l’antico lago di caira (presente dal 1724 al 1904), attualmente estinto e trasformato in vivaio della forestale, è ubicato a valle dell’abitato di caira, frazione di cassino (fig. 5). si colloca quasi alla confluenza fra il torrente calcara ed il fiume rapido sul limite morfologico della conoide alluvionale sulla quale si è sviluppato il paese. lo sprofondamento che diede origine al lago di caira viene riportato in letteratura da numerose fonti che fanno, comunque, riferimento alle notizie riportate dal “giornale cassinese” dell’epoca, e successivamente raccolte nelle “historiae” di gattola (1733; 1734). in queste fonti si ritrova la seguente descrizione (riportata in latino e tradotta dalle scriventi): in questo anno 1724, non lontano da caira nella notte fra il 18 e 19 febbraio 230 fig. 4 tentativo di ubicazione di alcuni laghetti, oggi estinti, rinvenuti su mappe storiche del 1715 e 1734 e principali allineamenti. hypothesis of location of some buried lakes and ponds recognized on historic maps (1715 and 1734) and principal alignments. fig 5 la piana di cassino-caira (piana del f. rapido), ubicazione del lago di caira, nel riguardo interno il lago come si presenta oggi. cassino-caira intermountain plain (rapido river plain); location of the caira lake; in the box the view of the lake. s. nisio & f. scapola con ingente strepito, tale che gli abitanti pensando che fosse un terremoto avevano abbandonato le case, la terra di otto tomoli, ciascuno dei quali comprende novecento cubiti napoletani di otto palmi, fu vista sprofondare a perpendicolo in quel luogo, dove c’erano alcuni alberi. la profondità di novanta palmi napoletani subito da parecchie sorgenti poste nella circonferenza dei lati iniziò ad essere riempita, mentre l’acqua cresceva così di giorno in giorno, che dopo un mese soltanto per cinque palmi distava dal piano del terreno. tutta la circonferenza del lago è di duecentosettantacinque cubiti napoletani, il diametro da oriente ad occidente circa centoventiquattro, e trasversale circa centotrentanove. oltre a questi eventi, nel giornale cassinese e negli scritti di gattola (1734), viene riportato: “la notte fra il 18 ed il 19 febbraio dello stesso anno nel luogo, ove è ora, il lago di cairo, un rumore fortissimo si intese ed i contadini che abitavano nei dintorni, come se un grande terremoto fosse accaduto, abbandonando le loro case fuggirono…… “ un'altra “fossa”, oltre al lago, si aprì alle pendici orientali di monte cairo e la tradizione afferma che in determinati periodi si sentivano dei rumori, come lamenti, provenire dalla stessa; gli abitanti del luogo iniziarono a buttare rifiuti all’interno della fenditura. dopo un po’ di tempo si accorsero che i frutti lanciati nella voragine le sere precedenti venivano ritrovati nei pressi dell’attuale chiesa madre nell’abitato di cassino. da altre fonti si ricava che il livello del lago non subiva variazioni stagionali e, periodicamente, era soggetto ad una fase di intorbidimento delle acque e le stesse venivano rese acide da uno improvviso aumento della concentrazione di zolfo. riportiamo il testo di baratta (1978): “….nacque così il lago di caira le cui acque non si vedono crescere anche nei tempi più piovosi, né diminuire. di questo lago i monaci fecero un vivaio di pesci ma periodicamente le acque si intorbidavano, probabilmente per l’afflusso di sorgenti sulfuree, ed i pesci rimanevano tramortiti. si rianimavano, però, dopo pochi giorni. la periodicità del fenomeno era tanto nota che i pescatori vi si recavano, a data fissa, per farvi buona pesca.” altre notizie del lago risalgono a de marco (1888): "il detto lago ritiene ancora la forma arrotondata; ma la circonferenza è più grande, la profondità molto minore, e la superficie è occupata da un lato quasi per un terzo da piante acquatiche a causa della terra ivi trasportata dal torrente che viene dai monti vicini. avendolo io misurato nel gennaio di quest’anno, ho trovato la sua periferia di 525 m (con un diametro medio di 165 metri circa)". si ha notizia di numerose sorgenti sulfuree (puzzaturiello, fig. 6) presenti a quell’epoca nell’area, la loro provenienza tuttavia è sempre stata imputata alla risalita, secondo vie preferenziali, di acque appartenenti alla falda profonda. e’ possibile che il progressivo svasamento del lago ed il continuo apporto di materiale detritico da parte dei torrenti abbia formato, nel tempo, un manto impermeabile al fondo impedendo l’interscambio delle acque. periodicamente i sedimenti fini potrebbero essere stati rimossi, all’aumentare della pressione della falda sottostante (questo spiegherebbe l’intorbidamento delle acque associato all’immissione di acque sulfuree nel lago). questo fenomeno lascia comunque ipotizzare la presenza di un condotto di collegamento fra la falda profonda, presente nei calcari, e le acque del lago. nel 1902 del foco scrive: "a destra di questa strada traversa, v’ha il laghetto di caira con scarse sorgenti interne. la superficie di questo lago, pel materiale importatovi da due torrenti che scendono a settentrione e a mezzogiorno del colle del forno e dei monticelli, che si riuniscono a caira, va anno per anno restringendosi, e finirà collo scomparire del tutto, con miglioramento delle condizioni sanitarie di quei dintorni infestati dalle febbri palustri. intanto quanto sarebbe desiderabile che l’autorità venisse in aiuto del lavoro lento della natura…". poco dopo il consiglio comunale decise di prosciugarlo, ma eventi naturali precedettero questo intervento di bonifica; durante una fase di piena del fiume una grande quantità di detriti si riversò nel lago (restò attivo almeno fino al 1904; fig. 6). il lago si prosciugò e, nel corso degli anni la forma si obliterò definitivamente. attualmente all’interno del vivaio della forestale sono presenti alcune sorgenti che manifestano periodiche risalite di gas. la successione stratigrafica dell’area circostante il lago (fig. 7 a, b), come rilevato da pozzi e sondaggi geoelettrici, varia procedendo da monte verso valle (da est ad ovest). nell’area di affioramento della conoide alluvionale, al di sotto di una fascia pedogenizzata (con spessore di pochi metri fino ad alcune decine), si rinvengono detriti di falda, con spessori considerevoli (cento metri circa) in contatto diretto con il substrato cabonatico. più a valle, nella zona di piana, i pozzi n.1 e n.2 (fig. 7b), molto prossimi al paleolago, mostrano la presenza di un’alternanza di argille, limi argillosi con ciottoli 231 fig. 6 mappa storica del 1902 ove è ancora riportato il lago di caira, è possibile, inoltre, individuare nelle vicinanze il toponimo puzzaturiello che fa ipotizzare presenza di gas e acque sulfuree. historic map of the 1902; it is showed the caira lake; it is possible to see close to the lake the puzzaturiello area. it demonstrate the presence of h2s acid water. ( in dialectical italian “puzzaturiello” sounds like “smelly”). individuazione di aree a rischio ... calcarei e ciottolate, il tutto al di sopra di un substrato carbonatico ubicato intorno a settanta metri di profondità dal piano campagna. questo tipo di successione stratigrafica determina valori bassi di permeabilità verticale, mentre valori elevati, negli strati a granulometria più grossolana, di permeabilità orizzontale. e’ possibile, pertanto, trovare nella copertura detritica più falde sospese ed una falda imprigionata all’interno del substrato calcareo (permeabile per fratturazione e carsismo) ribassato tettonicamente. 6.1.1 geometria iniziale della forma ed evoluzione nel tempo. ci si imbatte in molte difficoltà per determinare le dimensioni iniziali dello sprofondamento che originò i l lago di caira. prima fra tutte la “discordanza” delle fonti, l’incongruenza di alcune di esse e la parzialità e/o incompletezza dei dati forniti da altre. per ricostruire la geometria iniziale della voragine bisogna partire dalle notizie storiche di gattola (1734). in queste sono presenti le seguenti indicazioni, riportate in latino e di seguito tradotte: a) sprofondati otto tomoli di terreno, ciascuno di 900 “cubiti napoletani di otto “palmi” ; b) perimetro della voragine 275 cubiti napoletani; c) asse est-ovest 124 e nord-sud 139 (dei quali l’autore non riporta però l’unità di misura). saragosa & saragosa (1998), tradussero il testo latino dell’autore, ed indicarono che, al momento della formazione, la cavità presentava una circonferenza di 550m e diametri di 250m e 280m. si è invece rilevato che questi dati non trovano corrispondenza tra di loro e non corrispondono alla situazione reale. volendo ricavare le dimensioni della forma in base alle antiche unità di misura si riscontrano due problemi: a) è difficile attribuire un valore preciso alle unità di misura adottate: i cubiti napoletani non vengono contemplati in nessun testo tra quelli consultati; b) nel riportare le dimensioni degli assi non è stata indicata l’unità di misura utilizzata. per accertare le reali dimensioni del lago sono state consultate fonti storiche, enciclopedie del lessico italiano e testi latini. dopo molti accertamenti si è giunti alla conclusione che le misure degli assi di (124 e 139) erano espresse in palmi e che ai palmi napoletani poteva essere attribuito il valore di 26,4 cm. applicando una formula approssimativa del perimetro dell’ellisse si riscontra che il valore dei due assi è espresso con un un’unità di misura diversa da quella del perimetro. dopo numerose ricerche concludiamo che i valori riportati nella letteratura riferiti al perimetro possono essere ricondotti ai cubiti attici e romani ai quali viene 232 fig. 7 a) schema geologico semplificato dell’area dove è avvenuto lo sprofondamento di caira; a sinistra un sondaggio geoelettrico; b) le stratigrafie dei pozzi 1 e 2. a) geological scheme, in the sinking caira area; b) electric borehole; on the right borehole (1 and 2) stratigraphy. 7a) 7b) s. nisio & f. scapola attribuito un valore di 44,4cm. individuate le unità di misura, e rimanendo fedeli alle indicazioni di gattola (1734) per quanto riguarda le proporzioni degli assi, si ricava che il lago di caira, al momento della sua formazione, aveva l’asse maggiore di 41 m, il minore di 37 m, il perimetro di 122,1m, una profondità di 23,7m (90 palmi napoletani) ed un’area di 310m2. misure effettive sulle dimensioni del lago, dopo una sua evoluzione, risalgono a de marco (1888): "avendolo io misurato nel gennaio di quest’anno, ho trovato la sua periferia di 525m (con un diametro medio di 165 metri circa)" questo significa che in 164 anni lo svasamento dei bordi con la rimozione delle particelle ha più che quadruplicato le dimensioni originarie (sulla sezione igm al 10.000 il diametro della paleoforma è di 170 m). l’interrimento del lago è successivo all’anno 1902; presumibilmente avvenne pochi anni dopo (del foco, 1902; fig. 6). 6.2 altre aree interessate da sprofondamenti la conferma della presenza dello sprofondamento di caira nell’area ha stimolato ulteriori ricerche storiche e ricognizioni in tutto il territorio per individuare altre cavità o paleoforme; difficilmente infatti un fenomeno di sinkhole s.s. si rinviene isolato. e’ stata indagata, in principio, tutta la piana di cassino, partendo dal sito in cui è stato riconosciuto il lago di caira. l’analisi delle foto aeree di tutta l’area ha messo in evidenza altre tre forme sub-circolari ormai obliterate (fig. 8), due in località vertelle (con diametri di circa 250 m) e una presso masseria chiusavecchio dove si evidenzia una paleo forma gemellata (data dalla fusione di due cavità sub-circolari) con diametro maggiore di 380 m circa. il successivo sopralluogo sul terreno presso masseria chiusavecchio ha evidenziato la presenza di un piccolo lago (fig. 8) ormai quasi estinto: la pescarola (la denominazione antica ricordata dagli abitanti, i quali affermano che si formò naturalmente), con diametro attuale di 25-30 m e scarsa profondità. alcuni abitanti affermano che il lago era già presente alla fine dell’1800 con dimensioni molto più grandi ed adibito a vivaio. negli archivi della abbazia benedettina, un atto di vendita presente nei regesti ha confermato la presenza della pescarola già nel 1676. nel 1920 tutta l’area è stata bonificata e molte polle, stagni ed eventuali cavità sono stati ricolmati. inoltre, durante il sopralluogo, è emerso che a poca distanza dalla pescarola era presente un altro laghetto, presso l’area in cui oggi sorge l’ospedale. nel corso dei lavori per la costruzione dell’ospedale si sono verificati eccessivi cedimenti del terreno (gli ultimi nell’agosto 2005) che hanno portato alla provvisoria sospensione dei lavori. il sopralluogo condotto sul terreno in località vertelle (dove si distinguevano altre forme subcircolari) non ha dato però esiti positivi in quanto l’urbanizzazione del territorio ha ormai obliterato le presunte cavità. nei pressi del lago di caira (antico mulino) è stata individuata un’altra paleoforma risalente almeno al 1200. nella porzione settentrionale della stessa piana presso s. elia fiumerapido, l’analisi fotointerpretativa ha evidenziato la presenza di altre tre paleo-forme (fig. 9), di cui due coincidono sul terreno con polle subcircolari con diametri di 8-10 m (salaluca e magnesiaca; fig 9), sedi di sorgenti di acqua mineralizzata, con abbondanti risalite di gas. le portate stimate delle sorgenti sono di 94l/sec e 68 l/sec (caramadre 1996), le conducibilità rispettivamente di 445 µσ (nel 1996) e 935 µσ, la salinità di 370 e 660 g/cm3 rispettivamente. gli alti valori di conducibil ità sono compatibili con acque di provenienza profonda. presso la polla magnesiaca e’ stata eseguita la batimetria con ecoscandaglio che ha fatto registrare la presenza di una cavità tronco-conica, con pareti sub-verticali e profondità di 8 m. per quanto riguarda i dati di sottosuolo un sondaggio geognostico, reperito nelle vicinanze delle due polle, mostra la presenza di limi argillosi sino alla profondità di almeno 50m (fondo foro; fig. 9) e di due falde sovrapposte rispettivamente a 24 m e a 49 m, corrispondenti con livelli permeabili. durante il terremoto del 1984 l’acqua proveniente dalla sorgente magnesiaca ha subito intorbidimento per 3 giorni circa, con risalita di fango. i dati relativi alla polla magnesiaca sono riportati in tab. 1. in prossimità della sorgente magnesiaca era presente un’altra cavità circolare, oggi inac233 fig 8 ubicazione della pescarola; colonna stratigrafica riportante i dati di sottosuolo nelle vicinanze del laghetto e immagine di come la pescarola si presenta oggi. location of the pescarola pound; stratigraphy of the borehole data and pescarola pound view. individuazione di aree a rischio ... cessibile, contenente attualmente acqua. l’esame delle mappe storiche conferma che presso l’abitato di sant’elia, nei primi del settecento erano presenti tre laghetti uno dei quali in località acqua nera (fig 9; fig 12); le posizioni coincidono con le polle e le paleoforme individuate. la seconda area indagata è ubicata presso s. giorgio al liri (fig. 10), nella porzione meridionale del bacino lirino. nei pressi dell’abitato è ubicato il lago di acquasanta che oggi si presenta come un piccolo specchio d’acqua, con diametro di 12 m e profondità di 1,5 m, ma che, in passato, doveva avere dimensioni più grandi, infatti è presente in una mappa storica del 1700 (disegni ad acquerello di m. guglielmelli; fig. 12). il laghetto presenta emissioni di gas ed una probabile emergenza al fondo. nelle vicinanze del primo laghetto, nella piana del liri, è presente un’altra cavità sub-circolare colmata d’acqua, sede di sorgente di acqua ferruginosa risalente almeno ai primi del 1700. all’interno dell’abitato di s. giorgio al liri è ubicato un terzo laghetto ormai con sponde antropizzate e collegato al liri tramite canale artificiale, la cui origine dovrebbe risalire a più di 300 anni (è infatti riportato nelle carte antiche di gattola,1734, e di guglielmelli, 1715; fig. 10; fig. 12). il diametro della cavità è diminuito nel tempo, attualmente si attesta intorno ai 30-40 m e la profondità è pari a circa 2 m. la forma del laghetto di s. giorgio in origine era circolare; infatti l’urbanizzazione dell’area ha seguito la morfologia dell’antico perimetro del lago, e ciò testimonia che la nascita dell’abitato è successiva allo stesso (informazioni fornite dal comune di san giorgio a liri). una quarta cavità asciutta, ormai obliterata, è presente presso località s. marco: negli anni 50 il diametro si attestava intorno ai 47 m, attualmente è pari a circa 20 m; probabilmente la cavità naturale è stata successivamente sfruttata per recupero di inerti. 234 fig. 9 in alto ubicazione , presso s. elia fiumerapido, delle sorgenti e del pozzo con la relativa colonna stratigrafica; in basso, foto della sorgente magnesiaca come si presentava nel 1996 (foto di r. caramadre) e come si presenta nel 2005. at the top location of the s. elia fiumerapido springs and pounds, and borehole stratigraphy. at the bottom magnesiaca sinkhole pound photograph: in the 1996 ( left photo by caramadre) and in the 2005. fig. 10 in alto sono riportate le ubicazioni dei laghi presso s. giorgio al liri e della paleoforma asciutta nonchè del sondaggio geognostico immagini dei laghetti presso s. giorgio al liri (a sinistra) e acquasanta; a destra stratigrafie del sondaggio geognostico. at the top are represented s. giorgio al liri lakes, paleoform and borehole location. photograph of th s. giorgio lake and acquasanta lake; to the right bore hole stratigraphy. tab. 1 principiali parametri geochimici delle acque nell’area di s. elia e s. giorgio al liri. main geochemical parametres of the water samples in the s. elia s. giorgio al liri area. toponimo ph eh cond. µµ σσ t c° bicarbonati ml/l sorg. magnesiaca s. elia 6,63 164 935 13.05 732 lago di acquasanta 7,46 117 327 17 244 sorgente ferruginosa 7,4 0 370 15 317 lago di s. giorgio al liri 7,58 98 372 16 244 s. nisio & f. scapola durante il sopralluogo in sito sono state condotte analisi delle acque i cui dati vengono mostrati in tab.1. dai dati raccolti emerge che le conducibilità sono compatibili con lo scorrimento delle acque in terreni di natura alluvionale, i valori di ph potrebbero essere stati contaminati con apporti di acque superficiali e di scolo provenienti dai canali artificiali. i dati di sondaggio, nei pressi del laghetto di s. giorgio (fig. 10), mostrano una successione di limi e argille sino alla profondità di 85 m successivamente brecce calcaree e ghiaie sino alla profondità di 128 m, ed infine argille sino a foro 135 m. il substrato carbonatico, non riscontrato mai in sondaggio, pertanto, è molto profondo; si può escludere così una genesi carsica dei laghetti. nei sedimenti è stata, inoltre, riscontrata una falda in pressione alla profondità di 70 m che risale sino al piano di campagna. la terza area indagata è la piana di sora (fig. 11), a nord-ovest di cassino, in cui è stato rinvenuto un antico lago oggi ricolmato, il lago tremoletto. questo è ubicato nella tenuta dei conti manconi, secondo alcune fonti l’origine risale ad alcuni secoli addietro, in epoca borbonica; risulta comunque già presente nei primi del 1800. secondo altre fonti esso sarebbe stato originato da un episodio catastrofico, e caratterizzato dalla presenza di tremori e boati nel sottosuolo, da cui il nome “tremoletto”. a partire dal 1800 il lago ha iniziato a colmarsi per gli apporti detritici del fiume fibreno e ridotto ad un piccolo specchio d’acqua, dopo il 1948, è stato definitivamente bonificato. le stratigrafie dei sondaggi geognostici mostrano una copertura sedimentaria di sabbie e limi sino ad una profondità variabile tra i 15 m e i 25 m; al di sotto si rinvengono sabbioni calcarei e bancate di travertino di spessore complessivo di circa 20 m (fig. 11). i sondatori hanno riscontrato la presenza di vuoti alla profondità di 20-25 m. il livello di falda si attesta ad una profondità media di 40-50 m circa. ulteriore conferma della presenza di fenomeni di sprofondamento all’interno della piana di sora provengono dalla cronistoria del terremoto di avezzano, del 13 gennaio del 1915, quando si è aperta una cavità nel terreno con fuoriuscita di acqua mista a fango con formazione di vulcanelli e fontane di sabbia. dalle osservazioni finali sulle ricognizioni effettuate di paleoforme e dei laghetti rinvenuti tra la piana di cassino e s. giorgio al liri, si evince che essi si allineano secondo una direttrice orientata circa ns (n10e): la faglia theodicea; fig. 1. 7. discussione e conclusioni la situazione geologico-strutturale ed idrogeologica della bassa valle latina, ed in particolar modo delle piane di cassino e sora, è predisponente alla formazione di fenomeni di sinkhole. le piane su cui si sviluppano gli abitati sono di origine tettonica; i depositi quaternari che le colmano, con spessori di oltre cento metri, sono costituiti in prevalenza da un’alternanza di limi e argille, dotate di discreta consistenza e subordinatamente da sabbie e ghiaie; solo a luoghi, includono bancate o lenti di travertino (ad ovest del f. gari, per esempio presso la piana di sora, e i dintorni di aquino). le dorsali carbonatiche circostanti le piane sono fortemente interessate da fenomeni carsici (doline di crollo o di soluzione normale); il substrato carbonatico, al di sotto della copertura quaternaria, è profondamente disarticolato da diversi sistemi di dislocazioni ed è sede di un acquifero confinato, in cui si esplica una notevole circolazione idrica (sorgenti con portate complessive superiori ai 20 m3/s). a ciò si associa una forte circolazione sotterranea di fluidi aggressivi per la presenza di h2so4 e h2s legati al vulcanesimo di roccamonfina e/o ad una circolazione molto profonda all’interno di sistemi di faglia. l’attività antropica con emungimento indiscriminato delle acque dal sottosuolo, dal 1984 ad oggi, ha 235 fig. 11 ubicazione del lago tremoletto, presso la piana di sora (nel riquadro interno il lago come si presenta oggi) e stratigrafie dei sondaggi. ubication of tremoletto lake, in the sora plain (in the box a view of the lake now) and borehole stratigraphy. fig. 12 esempi di mappe storiche. disegni a d acquerello di guielmelli (1715), con ubicazione di alcuni laghetti. examples of historic maps: watercolors of guielmelli (1715); locations of some sinkhole ponds. individuazione di aree a rischio ... determinato l’abbassamento repentino del livello di falda e la migrazione di alcune sorgenti. l’attività tettonica recente del settore è testimoniata dalla sismicità sia storica che strumentale che ha colpito in particolare l’area di cassino dove, in occasione anche di piccole scosse strumentali, si sono verificati cedimenti del terreno di alcuni centimetri. tali caratteristiche al contorno conferiscono all’area tutte le condizioni predisponenti ed innescanti per la formazione di fenomeni di sprofondamento (sinkhole s.s.). infatti l’intera area in epoca storica era caratterizzata dalla presenza di piccoli laghetti di forma sub-circolare, (nota per questo motivo come terra dei laghi) rinvenuti su mappe antiche (ne sono stati individuati ben 23), ma oggi scomparsi o di difficile ubicazione, inoltre alcune leggende e fonti storiche narrano dell’apertura nel terreno di grandi voragini. la ricerca sul territorio ha permesso di individuare alcune morfologie sub-circolari coincidenti con piccole polle, laghetti o cavità. tra questi il lago tremoletto, nella piana di sora (di cui purtroppo si hanno pochi dati), che si è formato in seguito ad uno sprofondamento repentino del terreno in epoca borbonica non precisata; in parte interrito dagli apporti detritici del f. rapido, è stato ricolmato artificialmente dopo il 1948. la presenza però al di sotto del lago di bancate di travertino e la segnalazione da parte dei sondatori di alcuni vuoti, riscontrati durante i lavori di escavazione, possono far ipotizzare per questo lago un meccanismo di tipo diverso, probabilmente assimilabile da un covercollapse sinkhole. nella stessa piana di sora, tuttavia, le cronistorie del terremoto di avezzano nel 1915 narrano dell’apertura di una cavità con connessi episodi di liquefazione e di fuoriuscita di acque mineralizzate. più a sud, nel bacino lirino, le ricerche storiche hanno portato all’individuazione di altri laghetti di forma sub-circolare: i laghi di s. giorgio e acquasanta non riconducibili a fenomeni carsici in quanto originati al di sopra di una copertura argillosa-limosa (con spessori maggiori di 135 m) in cui è presente una falda in pressione. la conferma dei fenomeni di sinkhole è stata però accertata con lo sprofondamento di caira, noto in letteratura come lago di caira, formatosi nella notte fra il 18 ed il 19 febbraio del 1724. la raccolta di dati ha permesso di avere un quadro chiaro ed esaustivo della situazione. il lago di caira si è formato nella piana omonima, a poca distanza dall’abitato, su di una copertura costituita da un’alternanza di argille, limi argillosi con ciottoli calcarei e ghiaie con spessore di cento metri, al di sotto della quale affiora il substrato carbonatico. la falda profonda è in pressione, mentre i depositi quaternari, al tetto, contengono piccole falde sovrapposte a profondità rispettivamente di 25 m e 40 m dal p.c., in corrispondenza di lenti od orizzonti più permeabili. la voragine si è aperta in corrispondenza di un elemento tettonico di importanza regionale individuato durante i rilievi di campagna, il cui piano è visibile presso s. angelo in theodice e che attraversa tutta la piana: la faglia teodicea (con andamento circa n5-10e). all’interno della cavità vi era risalita di gas (h2s ), testimoniata dalle fonti storiche, ed a poca distanza erano ubicate sorgenti sulfuree (oggi estinte) che alimentavano il corso del fiume rapido. la morfologia della cavità risulta essere cilindrica, con pareti verticali profonde 23,5 m; è presumibile pensare che l’alimentazione del lago (il cui livello non oscillava mai) fosse dovuta all’apporto della falda più superficiale (25 m di profondità), ma non si può comunque escludere la presenza di ulteriori piccole polle di risalita di acque sulfuree (infatti periodicamente si assisteva alla morte per asfissia della fauna acquatica). in quest’area nel 1723 sono registrate nel catalogo dei terremoti molte scosse sismiche (di cui una molto intensa il 18 ottobre) ma non nella notte fra il 18 ed il 19 febbraio 1724 (anche se alcune fonti storiche narrano di un terremoto avvenuto proprio quella notte; due episodi sismici si verificarono nel settembre e nell’ottobre 1724, successivi però alla formazione del lago); pertanto non è possibile ricondurre il fattore innescante ad un evento sismico. non è noto, inoltre, se ci sia stata una brusca variazione del livello di falda attribuibile ad un evento pluviometrico importante. il processo genetico che ha originato il lago, data la profondità del substrato ed il notevole spessore dei sedimenti di copertura, nonché la loro composizione (prevalentemente limosa dotata di una certa consistenza), non può essere imputabile al lento scorrimento di particelle verso il basso (raveling) in quanto gli orizzonti argillosi-limosi impermeabili renderebbero difficile l’infiltrazione d’acqua e l’asportazione di particelle in profondità. inoltre la morfologia della cavità (così come viene descritta) cilindrica e non conica (caratteristica nei processi di raveling) fa piuttosto ipotizzare la presenza di un condotto. si esclude poi la presenza di una cavità a profondità intermedia (di circa 25-30 m) imputabile per esempio alla presenza di placche di travertino o di brecce carsificabili, in quanto non rinvenute in sondaggio. si propone pertanto un meccanismo erosivo che proceda dal basso verso l’alto collegato alla risalita di fluidi arricchiti nella componente gassosa (h2o + co2 + h2s) che avrebbero potuto sfruttare proprio la linea di debolezza, costituita dalla faglia theodicea. tale circolazione di fluidi accompagnata a processi di erosione, di sifonamento e di suffosione profonda (deep piping) dei materiali di copertura porterebbe, nel tempo, fino al collasso finale della copertura detritica. è quindi possibile che la cavità superficiale dipenda da processi agenti nel bedrock posto a notevole profondità. da quanto detto possiamo classificare lo sprofondamento che ha dato origine al lago di caira come sinkhole s.s ovvero un piping sinkhole. l’analisi fototointerpretativa su tutto il territorio ha permesso di individuare inoltre paleo-cavità e la verifica sul terreno ha confermato tali ipotesi: all’interno delle paleoforme si rinvengono laghetti in via di estinzione o piccole polle riconducibili a fenomeni del tutto simili a quello avvenuto a caira che potrebbero essersi formati nell’arco degli ultimi secoli. infatti nella piana di cassino sono presenti la maggior parte delle forme relitte sub-circolari, riconosciute: nei pressi di s. elia fiumerapido sono presenti tre forme coincidenti con antichi laghetti, in cui oggi si individua una piccola polla con sorgente (sorgente 236 s. nisio & f. scapola magnesiaca); a poca distanza da cassino sono state individuate altre paleoforme e la verifica sul terreno ha portato alla conferma della presenza di un piccolo lago, la pescarola, (presso masseria chiusavecchio) ormai quasi in estinzione. gli abitanti del luogo ricordano la presenza di un altro lago dove oggi sorge l’ospedale. a poca distanza dal lago di caira è inoltre presente una ulteriore morfologia subcircolare, delimitata da piccole scarpate, nelle cui vicinanze sorgeva un antico mulino (anno 1200), gli abitanti ricordano che anticamente era presente una sorgente e polle d’acqua stagnante. dai dati raccolti sull’intera area si può infine asserire che la piana di cassino, quella di sora e parte del territorio in pianura della provincia di frosinone sono aree ad elevata pericolosità di sinkhole, inoltre la crescente urbanizzazione del territorio e gli aumentati emungimenti di acqua dal sottosuolo ne fanno incrementare il rischio. infatti i lavori di costruzione di alcuni edifici (tra cui il nuovo ospedale) al di sopra di una paleo-forma di sprofondamento hanno subito già alcuni problemi durante l’esecuzione, ed altri ben più gravi potrebbero verificarsi in futuro soprattutto in seguito ad eventuali scosse sismiche, anche solo di tipo strumentale. pertanto il verificarsi oggi di un evento calamitoso, come quello che ha portato alla formazione del lago di caira, potrebbe certamente provocare oltre a danni gravi all’edilizia perdita di vite umane. ringraziamenti si desidera ringraziare i dott. giorgio caramanna e giancarlo ciotoli per il supporto durante i rilevamenti idrogeologici. il dott. angelo leopardi e il dott. alberto frepoli per la collaborazione alle ricerche, il dott. rossano caramadre per aver fornito alcuni dati idrogeologici. un particolare ringraziamento va a don gregorio dell’abbazia di cassino per la disponibilità durante le ricerche storiche e a don germano per il supporto durante le ricognizioni sul terreno. bibliografia accodi b. (1964) lineamenti strutturali del lazio e dell’abruzzo meridionale. mem. soc. geol. it., iv, 595-633, bologna. (1963). accordi g., carbone f., civitelli g., corda l., de rita d., esu d., funiciello r., kotsakis t., mariotti g. & sposato a.. (1988) note illustrative alla carta delle litofacies del lazio-abruzzo e delle aree limitrofe. quad. ric. scient., 144 (5), 93-168. agrillo e., bono p., casella l., d’andrea l., caramanna g. (2004) cavita’ di collasso recenti e antiche nel bacino lacustre di posta fibreno (frosinone). atti workshop “stato dell’arte sullo studio dei fenomeni di sinkholes e ruolo delle amministrazioni statali e locali nel governo del territorio roma 2021 maggio 2004”; 11-18. annunziatellis a., beaubien s.e., ciotoli g., lombardi s., nisio s. & nolasco f. (2004) studio dei parametri geologici e geochimici per la comprensione dei meccanismi genetici degli sprofondamenti nella piana di s. vittorino. atti conv. “stato dell’arte sullo studio dei fenomeni di sinkholes e ruolo delle amministrazioni statali e locali nel governo del territorio roma 20-21 maggio 2004”; 63-82. baj l. & tartaglia g. (1973) le risorse idriche del lazio con particolare riferimento all’area di intervento della cassa per il mezzogiorno. atti 2° conv. int. acque sott., 495-505, palermo (1973). baratta m. (1978) i terremoti d’italia. arnaldo forni editore, 95 pp bersani p. & castellano f. (2002) i sinkhole della piana di s. vittorino (rieti) e il rischio idraulico connesso. in: le voragini catastrofiche, un nuovo problema per la toscana. att. conv. 31 marzo 2000, (gr). regione toscana, 47-61. berti g., canuti p., & casagli n. (2002) voragini e sprofondamenti nel territorio nazionale: analisi morfometrica di alcuni casi caratteristici in aree appenniniche. in: le voragini catastrofiche, un nuovo problema per la toscana. att. conv. 31 marzo 2000, gr. regione toscana, 71-81. billiard a., muxart t., derbyshire e., wang g.t. & diykstra, t.a. (1992) les glissements de terrain induits parles loess de la province de gansou, chine. annales de geographie, 566,495-515. 1992. boni c., bono p. & capelli g. (1986) schema idrogeologico dell’italia centrale. mem. soc. geol. it., 35, 991-1012, 2 tavv. boni c.f. (1973) lineamenti idrogeologici dell’appennino carbonatico laziale-abruzzese (primi risultati della campagna 1970-1972). atti 2° conv. int. acque sott., palermo. bono p. (1995) the sinkhole of doganella (pontina, plain, central italy). environmental geology, 26, 48-52. campobasso c., graciotti r., nisio s. & letizia v. (2004) i l progetto sinkhole: le attività svolte dal dipartimento difesa del suolo dell’apat. atti conv. “stato dell’arte sullo studio dei fenomeni di sinkholes e ruolo delle amministrazioni statali e locali nel governo del territorio roma 20-21 maggio 2004”. 171-188. capelli g., petitta m. & salvati r. (2000) relationships between catastrophic subsidence hazards and groundwather in the velino valley (central italy) – procedings sixth international symposium on land subsidence sisols 2000, ravenna, italy. 1, 123-136. caramadre r. (1996) contributo all’idrogeologia del bacino del fiume rapido (lazio meridionale). tesi di laurea, relatore prof. piero barazzuoli. università degli studi di siena. a.a. caramanna g., nisio s. & vita l. (2004) fenomeni di annegamento dei sinkholes: casi di studio su alcuni laghetti di origine incerta. atti conv. “stato dell’arte sullo studio dei fenomeni di sinkholes e ruolo delle amministrazioni statali e locali nel governo del territorio roma 20-21 maggio 2004”, 229-248. carrara c. (1991) travertine deposits of the middle liri valley (central italy): geomorphological, sedimentological and geochimical study. palaoenviromental and palaoclimatic implications. il quaternario, n. 4 (1a), pp. 55-84. cavinato g.p., cosentino d., de rita d., funiciello r. & 237individuazione di aree a rischio ... parotto m. (1995) tectonic-sedimentary evolution of intrapenninic basin and correlation with the volcano-tectonic activity of central italy: memorie descrittive servizio geologico italiano, 39, 44-59. cavinato g.p & de celles p.g. (1999) exstensional basin in the tectonically bimodal central apennines fold-thrust belt, italy: response to corner flow above a subducting slab in retrograde motion. geology, 27-10, 955-958. celico p. (1976) nuove vedute sulla struttura della piana di cassino in base a recenti indagini idrogeologiche. boll. soc. nat. in napoli, 85, 1-16. celico p. & stanganelli v. (1975) le ricerche di nuove risorse idriche nelle regioni carsiche campane e molisane. e.s.a. atti 3° convegno internazionale “acque sotterranee” palermo. celico p. & stanganelli v. (1976) sulla struttura idrogeologica dei monti di venafro (italia meridionale). boll. soc. natur. in napoli, 85, pp. 1-26, tav. ii. cerisola r. & montone. p. (1992) analisi strutturale di un settore della catena dei monti ausoni-aurunci (lazio, italia centrale). boll. soc. geol. it., 111, 449-457, 5 ff., 1 tav. ciotoli g. di filippo m., nisio s. & romagnoli c. (2000) la piana di s. vittorino: dati preliminari sugli studi geologici, strutturali, geomorfologici, geofisici e geochimici. mem. soc. geol. it., 56, 297-308. colombi a., salvati r. & capelli g. (2001) sinkhole in latium region (central italy). purposes of the main project. in geotechnical and environmental applications of karst geology and hydrology. beck b.f. and gayle herring j. eds., balkema, the netherlands. damiani a. v. & panuzzi l. (1980) la neotettonica del f. 153 “agnone”. c.n.r., p.f. geodinamica, pubbl. n°365, 237-248, roma. damiani a. v. & panuzzi l. (1982) osservazioni neotettoniche nei fogli 151 “alatri” e 152 “sora”. c.n.r., p.f. geodinamica, sottoprogetto neotettonica, pubbl. n°506, 37-51, roma. de marco g. (1888) monte cassino: nei tre regni della natura. 216 pp. del foco o. (1902) cassino e le sue acque. milano, 79 pp. del prete s., de riso r. & santo a. (2004) primo contributo sui sinkholes di origine naturale in campania, stato dell’arte sullo studio dei fenomeni di sinkholes e ruolo delle amministrazioni statali e locali nel governo dl territorio. atti conv. “stato dell’arte sullo studio dei fenomeni di sinkholes e ruolo delle amministrazioni statali e locali nel governo del territorio roma 20-21 maggio 2004”, 361-376. derbyshire e. & mellors t.w. (1988) geologicaland geotechnical characteristic of some loess and loessic soil from china and britain: a comparison. engineering geologi, 25, 135-175. devoto g. (1965) lacustrine pleistocene in the lower liri valley. geol. rom., iv, 1965, 6, 291-368. di filippo m., palmieri m., toro b. (2002) studio gravimetrico del sinkhole di doganella di ninfa (latina). in: le voragini catastrofiche, un nuovo problema per la toscana. att. conv. 31 marzo 2000, gr. regione toscana, 62-70. di loreto e., liberi l., & piro m. (1999) riqualificazione ambientale del geotopo di lago puzzo, comune di fiano romano roma. mem descr. carta geol. d’it., liv, 339-346. dissertatio i. (1800) saeculum nonum a constructione coenobi cassinensis cap vii pars vii pp evernden c. & curtis l. (1965) the potassium-argon dating of late cenozoic rocks in east africa and italy. current antropology, 6, n. 4. faccenna c. (1994) structural and hydrogeological features of pleistocene shear zones in the area of rome (central italy). annali di geofisica, 37, 121133. faccenna c., florindo f., funicello r., & lombardi s. (1993) tectonic setting and sinkhole features: case histories from western central italy . quaternary proceeding n.3, 47-56. fairbridge, (1968) the encyclopedia of geomorphology. ed. reinhold, new york, 1295 pp, 1968. ferreli l., guerrieri l., nisio s., vita l. & vittori e. (2004) relations among seismogenic structures, earthquakes and sinkhole phenomena: a methodological approach in the apennines (italy). 32end international geological congress. firenze 20-28 ago 2004. vol. abs, part 1, 669. frepoli a. & amato a. (2000) fault plane solution of crustal earthquakes in southern italy (1988-1995): seismotectonic implications. annali di geofisica, vol. 43, n. 3, june 2000. frezzotti m., molin d. & narcisi b. (1988) correlazione tra caratteri stutturali e sismicità storica dell’area di roccamonfina. mem. soc. geol. it., 41, 12 ff. gasparini c., iannaccone g. & scarpa r. (1985) faultplane solution and seismicity of the italian peninsula. tectonophysic, 117, 59-78. gattola e. (1733) historia abbatiae cassinensis. pars seconda, venetiis, coleti, monte cassino. gattola e. (1734) ad historiam abatiae cassinensis accessiones. venetiis, coleti, 2, 907 pp. ghisetti f. & vezzani l.(1999) depth and modes of crustal extension during the pliocene-plleistocene evolution of the apenninic belt (italy). terra nova,11, 67-71. ghisetti f., kirschner d. l., vezzani l. & agosta f. (2001) stable isotope evidence for contrasting paleofluid circulation in thrust faults and normal faults of the central apennines, italy. journal of geophysical research, 106, b5, 8811-8825. graciotti r., nisio s., & vita l. (2004) sinkholes in italy: inventury of natural phenomena and some study cases. 32end international geological congress. firenze 20-28 ago 2004. vol abs, part 1, 670. guglielmelli m. (1715) la terra di s. benedetto. nei disegni acquerellati di marcello guglielmelli (sec.xviii). vol. 4. riproduzione banca popolare cassinate. cassino 1986. istituto nazionale di geofisica (2000) annali di geofisica vol. 43, n. 4, 609-868. august 2000; jandolo e. (1966) la bonifica benedettina. istituto della enciclopedia italiana, fond. g. treccani. leccisotti t. & avagliano f. (1977) i regesti dell’archivio. vol. vi, abbazia di monte cassino. littlefield j.r., culbreth m.a. upchurch s.b., stewart m.t. (1984) relationship of modern sinkhole development to large scale-pholinear features. in: 238 s. nisio & f. scapola beck barry f. (1984) sinkholes: their geology, engineering & environmental impact. ed. a.a. balkema/rotterdam/boston. mattei m., faccenna c. & funiciello r. (1994) paleomagnetic evidence for no tectonic rotation of the central italy tyrrenian margin since upper pliocene. geophysical research letters, 21, no. 6, pages 481-484. monroe w.h. (1970) a glossary of karst terminology. u. s. geol. surv. water sup. mouton j. (1973) contributo allo studio delle acque sotterranee del lazio meridionale. atti 2° conv. int. acque sott., palermo. narcisi b. (1986) ricerche di tefracronologia nella media e bassa valle latina. mem. soc. geol. it., 35, 909-912, 3 ff., 1 tab. nisio s. (2003) i fenomeni di sprofondamento: stato delle conoscenze ed alcuni esempi in italia centrale. il quaternario, 16(1), 121-132. nisio s, caramanna g., ciotoli g. (2005) sinkholes hazard in italy: first results on the inventory and analysis of some case studies. general assembly of the european geosciences union (egu), vienna april 24-29; geophysical research abs. vol. 7, 03922, 2005. nisio s., graciotti r. & vita l. (2004) i fenomeni di sinkhole in italia: terminologia, meccanismi genetici e problematiche aperte. atti workshop apat. “stato dell’arte sullo studio dei fenomeni di sinkholes e ruolo delle amministrazioni statali e locali nel governo del territorio roma 20-21 maggio 2004”, 557-572. nisio s. & salvati r. (2004) fenomeni di sprofondamento catastrofico. proposta di classificazione applicata alla casistica italiana. atti workshop apat “stato dell’arte sullo studio dei fenomeni di sinkholes e ruolo delle amministrazioni statali e locali nel governo del territorio roma 20-21 maggio 2004”, 573-584. parotto m. (1971) stratigraphy and tectonics of the eastem simbruini and westem marsica range (central apennines italy). mem. acc. naz. lincei, classe di scienze fis., mat. e nat., ser. 8, 10, roma. parotto m. (1980) apennin central. in: 26° congr. geol. inter. introduction à la géologié générale d’italie et guide à l’excursion. 112a, 33-37. parotto m. & praturlon a. (1975) geological summary of the central apennines. in c.n.r., structural model of italy. quad. ric. sci., 90, 257311. parotto m. & praturlon a. (1981) duecento anni di ricerche geologiche nell’italia centrale. “mem. soc. geol. it.” vol. giubilare “cento anni di geologia italiana”, 241-278. bologna pilla l. (1837) relazione dei tremuoti che afflissero la città di s. germano ed i l monastero di montecassino nella primavera dell’anno, 1837. regione toscana (2002) le voragini catastrofiche, un nuovo problema per la toscana. att. conv. 31 marzo 2000, gr. sacchetti g. i. (1920) storia geologica di montecassino (stato attuale delle conoscenze e ricerche personali). stabilimento tipografico emilio di mauro, cava dei tirreni. saragosa s. & saragosa l. (1998) caira, frazione di cassino, dalle origini ad oggi. tipografia francesco ciolfi cassino. salvati, r. & sasowsky, i. d. (2002) development of cover collapse sinkholes in areas of groundwater discharge. journal of hydrology, 264. saroli m., ciotoli g., lombardi s. & mariotti g. (2004) assetto geologico e possibile sviluppo di fenomeni di sinkhole lungo la “linea val roveto-atina” atti workshop apat “stato dell’arte sullo studio dei fenomeni di sinkholes e ruolo delle amministrazioni statali e locali nel governo del territorio roma 20-21 maggio 2004”. vol abs., 66. strahler a.n. (1954) quantitative geomorphology of erosional landscapes. c.r. 19th intern. geol. cong. algiers, sect. 13, part 3, 341-354. tharp t.m. (1999) mechanism of upward propagation of cover collapse sinkhole. engineering geology, 52, 23-33. varrone m.t. (1954) marco terenzio varrone ed il cassinate. roma 1954. 239 ms. ricevuto il 6 settembre 2005 testo definitivo ricevuto il 10 novembre 2005 ms. received: september 6, 2005 final text received: november 10, 2005 individuazione di aree a rischio ... imp.antonioli& lo studio della sezione “il fronte” per la definizione del piano tarentiano (puglia, italy) fabrizio antonioli1, alan deino2, luigi ferranti3, joerg keller4 , stefano marabini5, giuseppe mastronuzzi6, alessandra negri7, andrea piva8, gian battista vai5 & luigi vigliotti8 1enea, cre casaccia, roma italy 2berkeley geochronology center, usa 3dipartimento di scienze della terra, universita' federico ii, napoli, italy 4mineralogisch-geochemisches institut albert-ludwigs-universität, germany 5dipartimento di scienze della terra e geologico-ambientali, universita` di bologna, italy 6dipartimento di geologia e geofisica università degli studi di bari, italy 7dipartimento di scienze del mare universita' politecnica delle marche, italy 8ismar cnr bologna abstract: f. antonioli, a. deino, l. ferranti, j. keller, s. marabini, g. mastronuzzi, a. negri, a. piva, g.b.vai & l. vigliotti , the study of “il fronte” section to define the tarentian stage (puglia, italy). the italian commission on stratigraphy of the sgi is seeking for a marine section suitable for defining the upper pleistocene gssp. this series has been usually identified with the tyrrhenian stage which in the wake of formalization received different meaning from stratigraphers and geomorphologits. hence, the proposal of a new upper pleistocene stage name and type area, the tarentian, created in 1994. criteria for defining the tarentian stage and selecting its gssp can be the beginning of mis 5 (~ 134 ka) and the beginning of mis 1 (~ 10 ka) taken for the base of the holocene. the tarentian stage also contains mis 5.5 highstand with its peak at ~ 125 ka. upper pleistocene marine deposits of thickness exceeding 1 to 2 m are rarely exposed on land except for some mediterranean countries. italian coastal areas keep some hundreds of marine upper pleistocene sites. they are some characterized by the strombus bubonius senegalese tropical fauna. they are found at different elevations from -130 to +170 m depending on the strong differential crustal mobility of the area. the best up to some 10 m thick upper pleistocene marine sections are exposed at the coast of the gulf of taranto facing the ionian sea. here the regional uplift is less intense than at the apulian apennine front where it postdates mis 15. thus, there is a greater chance of finding part of the tarentian stage deposited in marine conditions. first results from the "il fronte" section in a km-long coastal cliff show from the base made by the plio-pleistocene blue clay fm.: (1) ~ 4 m thick massive to silty grey marine clay rich in planktic forams suggesting temperature fluctuations in a slope environment. the interval has normal magnetic polarity and the nanno plankton suggests a middle pleistocene age possibly in the range of 0,577 ma (lo g. omega) to 0,430 ma (lo p. lacunosa). (2) the top of this clay is marked by a two cm-thick white glass-rich high-potassic distal tephra horizon followed by a well laminated 20 cm-thick sapropel. shortly before the tephra, the forams indicate decreasing bottom oxygenation. (3) ~ 1.5 m of greygreen normal marine outer shelf mudstone passing upward to inner mudstone shelf. it is gradually succeeded by the over two m-thick subtidal strombus calcarenite yielding a 126 ka tims date. the rapid shallowing between (2) and (3) may suggest an omission gap. however, normal marine mudstone at least 1.5 m-thick underlies the shallow-water calcarenite which represents mis 5.5. within this continuous mudstone interval beneath the calcarenite the upper pleistocene gssp can be properly placed, and easily correlated with the continuous deep cores of the ionian sea and the oceans. parole chiave: mis 5.5, tarentiano. keywords: mis 5.5, tarentian. il quaternario italian journal of quaternary sciences 21(1a), 2008 35-38 l'international union of geological sciences (iugs) ha spronato l'international commission on stratigraphy (ics) a completare la definizione formale degli stratotipi del limite (gssp) dei piani della scala cronostratigrafica standard ancora non formalizzati entro tempi ragionevoli. ciò è avvenuto anche sotto lo stimolo della segreteria generale dell'iugs tenuta dall'italia in vista del 32° international geological congress (igc) di firenze 2004 organizzato dall'italia. l'obiettivo era di compiere l'opera entro l'igc di brisbane 2012. lo scopo era di avere un quadro certo di riferimento e stabile nel significato dei nomi cronostratigrafici, tale da garantire un linguaggio comune globale (italian commission on stratigraphy 2002; vai 2001, 2007). l'italia ha attivamente contribuito a quest'opera ottenendo l'approvazione di alcuni gssp sul territorio nazionale per piani del trias, del paleogene, del neogene (in particolare zancleano, piacenziano, gelasiano) e per il quaternario (pleistocene inferiore) (fig.1). il limite inferiore del pleistocene superiore è altrettanto, se non più importante perché rappresenta l'inizio dell'ultimo e massimo intervallo di riscaldamento naturale della storia recente della terra prima del riscaldamento in corso in presenza di marcata attività antropica. dopo il 32° igc firenze 2004, il nuovo presidente della subcommission of quaternary stratigraphy (sqs) dell'ics, prof. philip gibbard, ha comunicato che in mancanza di altre proposte migliori, si sarebbe a malincuore risolto a proporre il gssp del pleistocene superiore alla base del piano storico eemiano di ambiente continentale che, per essere mal esposto, 36 f. antonioli et al. (hearty e dai prà 1989, belluomini et al., 2002) sito in puglia presso taranto (mar piccolo), prescelto in base alle caratteristiche geomorfologiche e stratigrafiche (antonioli et al., 2007) quale sito potenziale del gssp. da un punto di vista geologico, il piano tirreniano scoperto e definito per la prima volta da issel (1914) a cala mosca in sardegna, è caratterizzato da depositi bioclastici di mare basso dello spessore da pochi decimetri al metro, con faune marine tropicali contenenti ospiti caldi tra i quali strombus bubonius sempre in discontinuità più o meno marcata sul substrato. questi depositi appaiono come il prodotto di una trasgressione talora erosiva su altri depositi marini, oppure più graduale su un substrato pedogenizzato o formato da depositi continentali. in ferranti et al., 2006, sono riassunte le descrizioni di 234 sezioni pubblicate in tutta italia, e l'interpretazione sismotettonica delle notevoli variazioni altimetriche riscontrate sulle coste italiane (da -130 a +170 m). l'unica area in cui, sotto tali depositi compaiono argille marine in apparente continuità e conformità è il bordo del golfo di taranto dove anche gli spessori della panchina fossilifera raggiungono i massimi di 5-6 m. nella penisola salentina, invece, la successione è meno spessa e poggia sempre sopra peliti continentali. quanto sottolineato sopra non deve sorprendere perché il golfo di taranto, e il mar piccolo in particolare, occupano una posizione geotettonica speciale. si trova infatti a cavallo di una zona di trascorrenza estovest di attivazione assai recente, che è sovrimposta a una ubicazione geodinamica speciale: vicina al fronte della catena appenninica e, più precisamente, al margine esterno della avanfossa bradanica e del suo cercine periferico (peripheral bulge) costituito dalla penisola salentina (bigi et al. 1992, vai and martini 2001). il sollevamento del fronte della catena a montalbano ionico è posteriore almeno al mis 15 (cfr. ciaranfi et al. 2007), verrebbe ubicato in una carota perforata a amsterdam. il presidente era conscio che una tale procedura sarebbe stata scorretta per essere in disaccordo con i principi e la pratica consuetudinaria stratigrafica. perciò si augurava che l'italia o altri paesi mediterranei preparassero proposte alternative. perciò, la commissione italiana di stratigrafia ha nuovamente chiesto a un gruppo di specialisti italiani di verificare la fattibilità di proposte alternative per la scelta del gssp di questo limite. i primi risultati di questo tentativo sono stati incoraggianti. esposti all'ultimo congresso mondiale dell'inqua a cairns nel luglio 2007, hanno riscosso l'interesse del prof. gibbard che ha richiesto una ricerca completa e approfondita che consentisse di presentare all'igc oslo 2008 una prima proposta sulle potenzialità di sezioni marine del nuovo piano tarentiano, e poi entro un altro anno al massimo una proposta formale completa da mettere al ballottaggio con la proposta olandese. il nuovo piano inizia tra la fine del mis (marine isotope stage) 6 e l'inizio del mis 5, (circa 134 ka), e termina con l'inizio del mis 1(10 ka). questo piano contiene anche il mis 5.5 il cui acme viene fatto risalire a 125 ka noto nel mediterraneo con il termine tirreniano dall'omonimo piano definito a suo tempo da issel nel 1914 (vai, 1996; cita et al., 2006) e mai formalizzato, come tanti altri piani. ne è derivato un uso difforme fra stratigrafi e geomorfologi. paradossalmente, questo limite non è stato studiato, nonostante l'esplicito invito della commissione italiana di stratigrafia che nel 1994 aveva sollecitato la comunità italiana a farlo e aveva proposto di sostituire il nome tirreniano con tarentiano indicando con ciò l'area di studio più promettente (cita e castradori, 1994). scopo della nostra ricerca e' dunque la formulazione di una proposta per il gssp del tarentiano presso la località “il fronte” a taranto. i principi e la pratica stratigrafica prevedono che lo stratotipo del limite di una unità cronostratigrafica standard (cioè a validità globale) sia posto in una successione marina, continua per almeno un certo tratto in cui si trova il limite, di ambiente pelagico non torbiditico e non troppo costiero (per dirla in breve, vedi isg 1976, 1994). il problema è che depositi tanto recenti quanto il pleistocene superiore difficilmente si trovano in aree emerse con spessori superiori a 1-2 metri. l'italia insieme ad alcune aree del mediterraneo presenta alcune centinaia di siti con affioramenti tirreniani (ferranti et al., 2006), e, per la sua marcata mobilità sismotettonica è una delle poche aree al mondo dove alcuni affioramenti di origine marina ascrivibili al pleistocene superiore si trovano con spessori superiori ai 10-15 metri. uno di questi è quello della località il fronte fig. 1 alcuni degli autori al lavoro nella sezione "il fronte di taranto". some authors working on the outcrop “il fronte taranto section". per cui c'è probabilità che nel mar piccolo e nei suoi bordi il sollevamento sia assai più tardo e meno intenso, tale da consentire la sedimentazione marina fino all'inizio o a una parte del tarentiano e la sua emersione solo dopo la sedimentazione della panchina a strombus bubonius. i primi risultati, per ora del tutto preliminari, sullo studio in atto alla sezione del fronte esposta nel mar piccolo di taranto, indicano che la parte immediatamente sottostante alla panchina è di età tirreniana (datazioni uranio torio effettuate su cladocora in posizione vitale su peliti) (fig.2). che queste peliti, sulla base di foraminiferi e nannofossili si sono depositate nel pleistocene medio. il tutto è confermato dalla magnetostratigrafia. nella porzione pelit ica del pleistocene medio sono presenti due livelli di tefra ed una laminite che potrebbe essere un sapropel. lo spessore che affiora è circa 12 metri. moltissime analisi sono in atto e altre verranno intraprese prima di proporre questo sito come potenziale gssp per il piano tarentiano. lo studio preliminare biostratigrafico colloca la sezione stratigrafica “il fronte” al di sopra della scomparsa di gephyrocapsa omega e di r. asanoi. la presenza di p. lacunosa è costante lungo tutta la sezione. in termini di schemi biozonali parliamo di zona mnn 19f di rio, raffi e villa 1990. ma considerando le eta' dei diversi eventi citati ci 37lo studio della sezione “il fronte” per la definizione ... troviamo in una fascia d'eta' compresa tra 0.577 ma (lo g. omega) e 0.430 ma (lo p. lacunosa). sulla base di queste osservazioni il sapropel individuato a 4 m circa potrebbe corrispondere al sapropel s12 (483 ka secondo lourens et al., 1996). dal punto di vista paleoambientale tutti i campioni osservati sono di ambiente profondo (tale da permettere la presenza di una associazione a nannofossili calcarei in situ, tranne gli ultimi 3 campioni in cui l'associazione e' completamente rimaneggiata. riferimenti bibliografici belluomini g., caldara, m., casini c., cerasoli m., manfra l., mastronuzzi, g., palmentola g., sanso' p., tuccimei p., vesica p.l., 2002. the age of late pleistocene shorelines and tectonic activity of taranto area, southern italy. quaternary science reviews 21, 525 547. cita m.b., castradori d., 1994. workshop on marine sections from the gulf of taranto (southern italy) usable as potential stratotypes for the gssp of the lower, middle and upper pleistocene. il quaternario 7(2), 677-692. cita m.b., capraro l., ciaranfi n., di stefano e., marino m., rio, d., sprovieri r., vai g.b., 2006. fig 2 coralli di cladocora coespitosa affioranti nella sezione "il fronte di taranto". cladocora coespitosa corals outcropping from "il fronte taranto section". calabrian and ionian: a proposal for the definition of mediterranean stages for the lower and middle pleistocene. epidodes 29, 107 114. dai pra g. & stearns c. e., 1977. sul tirreniano di taranto. datazione su coralli con il metodo th230/u234. geologica romana, 16, 231-242. ferranti l., antonioli f., amorosi a., dai prà g., mastronuzzi g., mauz b., monaco c., orrù p., pappalardo m., radtke u., renda p., romano p., sansò p., verrubbi v. (2006). elevation of the last interglacial highstand in italy: a benchmark of coastal tectonics. quat. int. 145-146, 30-54. hearty p.j., dai pra g., 1992. the age and stratigraphy of middle pleistocene and younger deposits along the gulf of taranto (southeast italy). journal of coastal research 8, 882903. issel a., 1914. lembi fossiliferi quaternari e recenti nella sardegna meridionale: accademia nazionale dei lincei, ser. 5, 23, 759770. italian commission on stratigraphy, 2002. lourens l.j., antonarakou a., hilgen f.j., van hoof a.a.m., vergnaud-grazzini c., zachariasse w.j., 1996. evaluation of the plio-pleistocene astronomical timescale. paleoceanography 11, 391413. maiorano p., e marino m., 2005. calcareous nannofossil bioevents and environmental control on temporal and spatial patterns at the early-middle pleistocene. marine micropaleontology 53 (2004) 405422 rio d., raffi i., villa g., 1990. pliocene-pleistocene calcareous nannofossil distribution patterns in the western mediterranean. in: kastens, k.a., mascle, j., et al. (eds.), proc. odp, sci. res. 107. college station, texas, pp. 513533. vai g.b., 2007. a history of chronostratigraphy. stratigraphy 4, 2/3, 83-97. vai g.b., & martini i.p., (eds), 2001. anatomy of an orogen: the apennines and adjacents mediterranean basins. kluwer academic publishers, 636 p. vai g.b., 1996. revisione critico-storica dei piani marini del quaternario. miscellanea, serv. geol. d'italia, 179 p., roma (coll. g. pasini). 38 ms. ricevuto il 2 aprile 2008 testo definitivo ricevuto il 17 aprile 2008 ms. received: april 2, 2008 final text received: april 17, 2008 f. antonioli et al. ojs 633 iannucci et al def.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 35 (2), 2022, 105-117 1. introduction hyenas were once an ecologically diverse group that showed adaptations to many different feeding behaviors, from the probable insectivory/omnivory of civetlike and mongoose-like species, to hypercarnivory and “bone-cracking” (kurtén, 1956; howell & petter, 1980; werdelin & solounias, 1991, 1996; semenov, 2008; turner et al., 2008; tseng et al., 2013; coca-ortega & pérez-claros, 2019; koufos, 2021; iurino et al., 2022; lewis & werdelin, 2022). the latter is almost the only ecomorphotype (or ecomorph; werdelin & solounias, 1996) that survived to the present day. indeed, with the exception of the aardwolf, proteles cristatus (sparrmann, 1783), which is a specialized termite eater (kruuks & sands, 1972; cooper & skinner, 1979), the other three living hyenas, crocuta crocuta (erxleben, 1777), hyaena hyaena (linnaeus, 1758), and parahyaena brunnea (thunberg, 1820), display a suite of craniodental traits that highlight their ability of cracking bones. this capacity gave bone-cracking hyenas access to resources out of reach of most other predators and scavengers, apart mainly from hominins, who could also crack and deflesh bones using tools. therefore, quaternary hyenas are often considered as potential competitors of hominins, stimulating research with vibrant paleoecological and taphonomic implications, but also engendering debate on the magnitude of homohyena interactions and relationships (stiner, 1991; turner & antón, 1996; boaz et al., 2000; lewis & werdelin, 2010; espigares et al., 2013; madurellmalapeira et al., 2017; iannucci et al., 2021b). an interesting period on which our knowledge on the evolution of hyenas is still rather imperfect is around 2.0–1.8 ma. at the time, the giant hyena pachycrocuta brevirostris (gervais, 1850) spread into europe, becoming soon after the only bone-cracking carnivoran for most of the early pleistocene (iannucci et al., 2021b). in some of the earliest localities where p. brevirostris is recorded, the giant hyena is accompanied by other species that will be no longer present in later faunas, namely the hunting hyena chasmaporthetes lunensis (del campana, 1914) and another bone-cracker, pliocrocuta perrieri (croizet & jobert, 1828). chasmaporthetes lunensis is a more gracile and cursorial species than the others, and its ecology is often discussed in comparison to carnivorans other than bone-cracking hyenas (kurtén & werdelin, 1988; ferretti, 1999; antón et al., 2006; tseng et al., 2011, 2013; pérez-claros et al., 2021; konidaris, 2022; marciszak et al., 2022). conversely, https://doi.org/10.26382/amq.2022.06 the lost hyena from paciano (umbria, italy) reconsidered. alessio iannucci 1, marco cherin 2, raffaele sardella 1 1 dipartimento di scienze della terra (paleofactory lab.), sapienza università di roma, roma, italy. 2 dipartimento di fisica e geologia, università degli studi di perugia, perugia, italy. corresponding authors: a. iannucci <alessio.iannucci@uniroma1.it> abstract: we redescribe and revise the taxonomic attribution of a lost hyena hemimandible recovered from paciano (umbria, italy), originally reported in the early 1900s, by comparing it with relevant samples of pliocene, pleistocene, and extant species. the mandible of the paciano hyena was initially attributed to hyaena striata (= hyaena hyaena) and subsequently listed as a record of the giant hyena pachycrocuta brevirostris, but is here assigned to another “bone-cracking” hyena, the pliocene-early pleistocene pliocrocuta perrieri. the paciano hyena contributes to the discussion on the relationships and turnover between pl. perrieri and p. brevirostris. on the one hand, the two species are very similar in craniodental morphology; their isolated remains are often separated by size; and p. brevirostris is thought to derive from a large-sized population of pl. perrieri. on the other, a larger size is not an aspect to disregard in hyenas as it usually correlates with the acquisition or better development of “bone-cracking” features; remains attesting the co-occurrence of pl. perrieri and p. brevirostris are known from some sites dated at around 2.0–1.8 ma; and the observed size differences between the two species exceed those recorded between extant and (at times) sympatric species. therefore, taken alone the competition with p. brevirostris does not explain the extinction of pl. perrieri, but considering it together with the concurrent spread and resulting peak of carnivoran diversity in late villafranchian faunas might. pliocrocuta perrieri was outcompeted by its larger descendent in scavenging carcasses, while other carnivorans limited its options to deviate to other resources or adopt a different feeding behavior (e.g., active hunting). the case of paciano is also significant in that it offers an example of the importance and feasibility of reconsidering historical collections, even when the original material is lost entirely. in general, the seek for “novelty” that permeates current scientific literature ensues in few descriptions or reconsiderations of historical samples, especially if the new examinations confirm old results, but we emphasize the significance of such efforts in making old data truly available for the scientific community. in addition, the hyena from paciano has a biochronological and stratigraphic value, confirming the occurrence in western umbria of a depositional cycle older than the late early pleistocene one (well represented by the rich assemblages from pietrafitta and selvella; farneta faunal unit). keywords: hyaenidae, carnivora; quaternary; europe; historical collections. 106 iannucci a. et al. pliocrocuta and pachycrocuta are considered ecomorphologically very close and indeed placed by some authors in the same genus (e.g., qiu et al., 2004; liu et al., 2021). arguments in favor of a “sharp” separation between pliocrocuta and pachycrocuta are some morphological differences, especially the lack of a metaconid in the lower carnassial in p. brevirostris (werdelin & solounias, 1991) and the co-occurrence of the two species in some european localities at ~2.0 ma (iannucci et al., 2021b). on the other hand, localities where hyaenid fossils have been assigned to both species are not but a few, and attributions are merely based on the size of the remains (iannucci et al., 2021b). from an ecological point of view, the increase in size in hyenas is nonetheless significant, as it is generally correlated to the acquisition or better development of “bone-cracking” craniodental features (werdelin & solounias, 1991). moreover, despite the paucity of available remains in relevant localities, the reliability of such size-based repartition would be corroborated by the low level of sexual dimorphism –in craniodental measurements– observed in c. crocuta (e.g., garcía, 2003; lewis & werdelin, 2022), assuming that the same holds true for pliocrocuta and pachycrocuta. in general, the spotted hyena is definitely the most studied amongst extant hyenas (e.g., kruuk, 1972; frank, 1986a, b; kolowski et al., 2007; holekamp et al., 2012), somehow “skewing” considerations on hyenas as a whole (werdelin & solounias, 1991; lewis & werdelin, 2022). however, considering how many aspects of c. crocuta biology and ecology are regarded as peculiar in comparison to other extant bone-cracking hyenas (e.g., kruuk, 1972; frank, 1986a, b; mills 1982, 1990) and that it has been suggested that several features might have evolved recently (werdelin & lewis, 2008), it remains to be answered to what extent similar characteristics were present in extinct hyenas (iannucci et al., 2022). in this framework, there is a critical need of description of more material that might be key to clarify. notwithstanding the importance of the recovery of further fossils from new excavations, revising historical collections might also offer new insights. the rediscovery of important specimens or new research in old localities is often the impetus for revising historical collections (e.g., bona, 2021; fabbi et al., 2021; mecozzi et al., 2021, 2022), but reconsiderations of many samples are never attempted, especially if represented by few specimens. the number of “sporadic” findings, that is, those fig. 1 geographic location of paciano (red star). the extensional basins cited in the text are highlighted. 107 the lost hyena from paciano not recovered during systematic excavations, can be substantial in localities with a long research tradition and/or when fossiliferous formations span vast areas (e.g., argenti, 2004; iannucci et al., 2021c; mecozzi et al., 2021). extensive fossil samples remain undescribed in museums and other institutions, which might be seen as a particular case of the “taxonomic impediment” (rodman & cody, 2003) in one of its worst forms, that is, not necessarily due to the lack of proper expertise, but to the poor motivation to undertake dedicated studies, given the long effort needed and the meager credit taxonomic and descriptive works might have (godfray, 2002; agnarsson & kuntner, 2007). in several cases, historical samples were the subject or works carried out at the time of their discovery, but then went entirely lost or destroyed for disparate reasons. notorious incidents that caused immeasurable loss of natural history collections span from the bombing of several museums and institutions during world war ii (e.g., crumly, 1984) to the recent fire of the national museum of brazil in 2018 (escobar, 2018). implications for such losses are huge, and the existence of historical descriptions can have great importance from purely taxonomic and nomenclatural considerations to all that follows (e.g., pape et al., 2018). paradoxically, however, the existence of previous works also adds further difficulties in offering stand-alone reconsiderations of historical samples, as they might be perceived as not original, the seek for “novelty” being a key aspect of current scientific publication practice (makel & plucker, 2014). in this context, umbria (central italy) represents an emblematic case. in fact, despite the small geographical extension but thanks to the considerable (vertical and horizontal) development of plio-pleistocene sedimentary basins on the territory, it has played and still plays a key role for the understanding of the faunal turnovers that occurred in the last 3 ma or so (cherin, 2013). the historical collections of fossil mammals from umbria have been known to science since the beginning of the 19th century (e.g., cuvier, 1821) and were often the preserve of nobles or other prominent personalities of culture and society (as was the case in many other parts of europe at that time). the recent reconsideration of some of these collections or of individual fossils has led to interesting knowledge advances. for instance, the revision of part of the mammal assemblage (cicioni and bellucci collections) recovered from villa spinola (perugia) in 1894-95 (tuccimei, 1895) led to the description of the only partial skeleton of the felid panthera gombaszoegensis (kretzoi, 1938) known in umbria to date (argenti & sardella, 2003). similarly, a recently reappraised mandible of tapirus arvernensis croizet & jobert, 1828 from the lignite mines of spoleto (clerici collection; clerici, 1895) was recognized as the southernmost record of this species in italy (pandolfi & kotsakis, 2017). here, we redescribe and revise the taxonomic attribution of a lost hyena hemimandible recovered from paciano (umbria, italy; fig. 1), originally reported by bortolotti (1905), comparing it with relevant samples of pliocene, pleistocene, and extant species. 2. materials and methods the original hyena right hemimandible recovered from paciano and described by bortolotti (1905) is apparently lost, as reported by argenti (2004) when listing fossil localities of umbria and as confirmed by our own surveys in relevant institutions. in detail, the paciano hyena was part of the ancient canali collection, a historical collection that went lost after the first decades of the last century (argenti, 2004). only a fraction of the canali collection is still curated in the regional direction for museums of umbria, including some other specimens described by bortolotti (1904). nonetheless, even if the original material is not available for direct examination, bortolotti (1905) provided measurements and comments that allow to compare and contextualize this important specimen in an updated taxonomic framework. bortolotti (1905) attributed the paciano hyena to hyaena striata (= hyaena hyaena), while argenti (2004) referred it to p. brevirostris. however, iannucci et al. (2021b) did not mention paciano among the occurrences of the giant hyena. the massive and straight mandibular corpus of the hyena from paciano adheres in morphology to that of a bone-cracking hyena. therefore, the mandible was compared with that of extinct and extant bone-cracking hyetab. 1 measurements (in mm) of the hyena right hemimandible from paciano provided by bortolotti (1905). l = length, w = width, m1 pa-pr = distance between paraconid and protoconid, m1 bhpa = buccal height of the crown at the paraconid, m1 bhpr = buccal height of the crown at the protoconid, m1 hmt = height of the crown at the metaconid, di = length of diastema c1-p2, c1 -m1 = inclusive length of c1-m1, p2-m1 = inclusive length of p2m1, hfp2 = dorsoventral height of the mandible in front of p2, hbm1 = dorsoventral height of the mandible behind m1, tpl = total preserved length of the mandible between the base of c1 and the rear of the ascending ramus. 1 approximate value according to bortolotti (1905). 2 we also consider these values approximations, as bortolotti (1905) reported that the tooth was fragmented above the base of the crown. 3 the true total length of the mandible would have been greater than the reported value. interno del ferino” (= “internal tubercle of the carnassial”; own translation from the original italian)] and a welldeveloped talonid hosting two cuspids (one buccally and one lingually) separated by a valley. 3.2. biometric comparison the results of the pca are consistent with those obtained by iannucci et al. (2021b). in logpca, the morphospace projection onto the first two components (figure 3) separates specimens mainly according to their size (along pc1, 86.5% of explained variance) and relative elongation of m1 (along pc2, 8.6% of explained variance). the large-sized p. brevirostris is placed on the right of the scatter plot and c. crocuta separated towards positive values on pc2. the other species are grouped on the left and are mainly, but not completely (apart from h. hyaena and “h.” prisca), distinct by size. some specimens of pl. perrieri, especially that from paciano, plot towards positive values along pc2, meaning they have relatively elongated m1. when the effect of size is adjusted in gmpca, the morphospace projection of the first two components (figure 4) separates specimens mainly on the base of the elongation of m1 (along pc1, 66.0% of explained variance) and the proportions of the premolars (along pc2, 21.4% of explained variance). the latter differences are mainly intraspecific and place specimens with widened premolar towards more negative values along pc2. basically, in gmpca only c. crocuta clearly occupies a distinct area of the morphospace, while there is overlap between all other species. also in this case, there are, however, few specimens of p. brevirostris and pl. perrieri, especially paciano, that plot closer to values observed for c. crocuta, having relatively elongated m1. detailed bivariate comparisons of length and width of each tooth confirm the differences in size observed with the pca (figure 5). hyaena hyaena is the smallest species in all considered measurements, while p. brevirostris is the largest in all but m1 l, in which it is surpassed by several specimens of c. crocuta. in terms of dental proportions, all species are similar, apart from c. crocuta, which is almost completely separated by other hyenas according to its relatively more elongated m1 (figure 5c). in general, measurements of the hemimandible from paciano place it among small-sized specimens. in detail, in the p3 scatter plot it falls within the ranges of h. hyaena and pl. perrieri, and not far from the smallest specimens of brown and spotted hyenas nas, namely pl. perrieri, p. brevirostris, c. crocuta, “hyaena” prisca, h. hyaena, and pa. brunnea. the sample from longdan (qiu et al., 2004), considering his potentially “transitional” position between pliocrocuta and pachycrocuta (iannucci et al., 2021b), is analyzed separately. length (l) and width (w) of third premolar (p3), fourth premolar (p4), and first molar (m1) were included in the analysis. here, the choice of variables was dictated by the availability of reliable measurements provided by bortolotti (1905), but previous biometric analyses similarly relied on the p3-m1 series (iannucci et al., 2021b). we used the dataset assembled by iannucci et al. (2021b), with the addition of the paciano specimen, as the input for two pca analyses on the variance-covariance matrix of the considered measurement, in the first case using log-transformed values (referred to as logpca in the text) and in the second “size-adjusting” raw measurements by dividing them by the geometric mean (gmpca) of all measurements for that specimen (mosimann, 1970; mosimann & james, 1979; jungers et al., 1995), the latter being an effective method to produce dimensionless variables widely adopted in studies on fossil mammals (e.g., ercoli et al., 2019; iannucci et al., 2021a). the software past version 4.04 (hammer et al., 2001) was used for the analysis. to avoid confusion when referring to different taxa, pachycrocuta is abbreviated to p., pliocrocuta to pl., and parahyaena to pa., when appropriate. measurements of the paciano hyena and related abbreviations are provided in table 1. 3. results 3.1. description bortolotti (1905) provided only a figure of the paciano right hemimandible, from which the morphology of the dentition is not very clear (fig. 2). still, the robust and straight corpus of the hemimandible is indicative of a bone-cracking hyena, similar in proportions to all species considered in the comparison except for c. crocuta, in which the body is shallower near the symphysis (palmqvist al., 2011; iannucci et al., 2022). according to bortolotti (1905), the mandible of paciano preserved the right p3-m1 series, with p2 and c1 also present but severely damaged. the author did not provide many details in his description of the specimen, but he emphasized the presence in m1 of a metaconid [“tubercolo 108 iannucci a. et al. fig. 2 the hyena right hemimandible recovered from paciano. modified from bortolotti (1905). fig. 3 scatter plot (a) and loadings (b) of the first two principal components of logpca. for raw data and detailed references, see iannucci et al. (2021b). 109 the lost hyena from paciano fig. 4 scatter plot (a) and loadings (b) of the first two principal components of gmpca. for raw data and detailed references, see iannucci et al. (2021b). 110 iannucci a. et al. 111 the lost hyena from paciano fig. 5 bivariate plots comparing l and w (in mm) of p3 (a), p4 (b), and m1 (c) of the hyena from paciano and several samples of extinct and extant bone-cracking hyenas. 112 iannucci a. et al. (figure 5a). in the bivariate comparison of p4 measurements, paciano is somewhat distinct from other species but closer to c. crocuta (figure 5b). considering length and width separately, in p4 l, paciano is compatible with c. crocuta, h. hyaena, pa. brunnea, and pl. perrieri, while p4 w only fits with h. hyaena and smallest values of c. crocuta. in m1 measurements, paciano again does not plot confidently in the range of one of the groups of the comparative sample, but it is close to specimens of c. crocuta, pa. brunnea, and pl. perrieri. 4. discussion bortolotti (1905) attributed the paciano hyena to h. striata (= h. hyaena), noting an overall resemblance with h. arvernensis (= pl. perrieri) but judging the specimen too small to belong to that species. indeed, our comparisons showed that there is some overlap, though limited, between the largest specimens of h. hyaena and the smallest of pl. perrieri in most measurement considered (figure 5). however, although the paciano hyena is apparently among the smallest specimens of pl. perrieri, it has a larger and proportionally more elongated m1 than that of h. hyaena, which separates it from this species. this evidence allows to identify the paciano hyena as pl. perrieri. considering the paucity of comparative material bortolotti (1905) had in his disposal, his taxonomic opinion represented the best fit for the then available evidence, but can now be confidently revised. pliocrocuta perrieri and the giant hyena p. brevirostris have a very similar morphology, and remains of the two species are often separated by size (iannucci et al., 2021b). in this respect, the small size of the paciano hyena clearly excludes an attribution to p. brevirostris, which was tentatively suggested by argenti (2004). bortolotti (1905) also underlined the presence of a welldeveloped metaconid in the m1 of the paciano hyena, a feature that reinforces its assignment to pl. perrieri (werdelin & solounias, 1991; iannucci et al., 2021b). in some measurements, the paciano hyena seems peculiar in comparison to other specimens of pl. perrieri. in detail, the p4 w (11.5 mm) is slightly below the minimum value of the sample of pl. perrieri included in the comparison (12.1 mm), although not outside the range known for the species (a minimum value of 9.3 mm is reported by coca-ortega & pérez-claros, 2019). moreover, although the specimen is small in most measurement, the value of m1 l is relatively high, denoting a proportionally elongated carnassial. however, considering the fragmentary nature of the specimen and that bortolotti (1905) evidently adopted a “coarse” approximation at 0.5 mm in his measurements, the observed differences are likely spurious. for completeness, it is worth mentioning that a reference of the paciano hemimandible to c. lunensis, a species that might have been compatible with the putative age of the fossil locality, is clearly discouraged by morphological and biometric traits, including the robust and straight mandibular corpus, the presence of a metaconid in m1, and the widened teeth, among others (werdelin & solounias, 1991; tseng et al., 2013). the presence of pl. perrieri at paciano has also implications for the age of the fossil deposit. the latest occurrences of pl. perrieri in europe are dated at ~2.0– 1.8 ma (iannucci et al., 2021b), and the species is certainly more abundant in older localities (e.g., viret, 1954; howell & petter, 1980; qiu, 1987; werdelin & solounias, 1991). in umbria, most plio-pleistocene mammal assemblages have been discovered within the tiberino basin, which extends across the center of the territory for ~1800 km2 (cherin et al., 2019). other findings are reported from the smaller tavernelle-pietrafitta basin, south of lake trasimeno, including the extremely rich assemblage from the pietrafitta lignite mines (martinetto et al., 2014; sorbelli et al., 2021, and references therein). finally, some other mammal remains have been recovered from the valdichiana basin, whose deposits crop out in few areas of western umbria (figure 1). among the latter discoveries, it is worth mentioning the assemblages from selvella and vigna nuova. the former was originally dated at ~1 ma (de giuli, 1987), but then referred to the farneta faunal unit (fu; ~1.5 ma; alberdi & palombo, 2013; cirilli et al., 2020), similarly to the aforementioned assemblage from pietrafitta. the case of vigna nuova is intriguing because taphonomic and geological evidence have allowed the sample to be divided into two assemblages (azzarà et al., 2022). the younger, including only remains of cf. leptobos collected from conglomerates (“upper layer”), can be correlated with other well-known valdichiana assemblages (e.g., selvella, farneta), thus dated at ~1.5 ma. the older sub-sample, coming from a putative paleosol (“lower layer”) no longer visible in the field, includes cf. megantereon, canis sp., mustelidae indet., proboscidea indet., equus cf. senezensis, cf. leptobos, croizetoceros ramosus, pseudodama sp., cervidae indet. (large size), and sus cf. strozzii. azzarà et al. (2022) referred this assemblage to the coste san giacomo fu (late middle villafranchian; ~2.2–2.1 ma). unfortunately, the exact provenance of the hyena from paciano is unknown. on the basis of the geographical location of the municipality of paciano (figure 1), the fossil could come from deposits of either the valdichiana or tavernelle-pietrafitta basin. therefore, given that the last occurrence of pl. perrieri is attested at the beginning of the late villafranchian (but the species is certainly more abundant in europe in the middle villafranchian), its presence in paciano could (1) confirm the presence of a late middle villafranchian sedimentary cycle in the valdichiana basin, in agreement with the recent discoveries at vigna nuova (azzarà et al., 2022) or (2) suggest the presence of a similar sedimentary cycle also in the tavernelle-pietrafitta basin, not reported so far. unfortunately, as it is not possible to define whether the fossil comes from one or the other basin, this doubt cannot be resolved. the paciano hyena likely falls in a time-span of great interest for the evolution of hyenas in europe, when some localities still document the presence of c. lunensis and pl. perrieri, but also the contemporaneous occurrence of p. brevirostris (iannucci et al., 2021b). if the coexistence between c. lunensis and the other species is easily justifiable by their different inferred ecology (e.g., werdelin & solounias, 1991, 1996; tseng et al., 113 the lost hyena from paciano 2011, 2013), that between pl. perrieri and p. brevirostris might seem to necessitate some further explanation, as they are very similar in craniodental morphology. a somewhat similar case that is worth considering here is the extinction in europe of p. brevirostris. after ~1 ma since its appearance in the european fossil record, the rule of the specialized bone-cracker came to an end close the early-middle pleistocene boundary, ~0.8 ma, approximately coinciding with the arrival of c. crocuta and “h.” prisca (iannucci et al., 2021b). competition between p. brevirostris and c. crocuta has often been advocated as a factor potentially favoring the disappearance of the former (e.g., kurtén, 1968; palombo et al., 2008). iannucci et al. (2021b) argued instead that the newcomers hardly played a significant role in the extinction of p. brevirostris, considering paleoecological and paleobiogeographical aspects, but mostly revising the putative records previously deemed to attest a persistence of the giant hyena in europe beyond the earlymiddle pleistocene boundary and its coexistence with c. crocuta. the authors also reasoned that although the error ranges associated with the available dating estimates for the last occurrences of p. brevirostris and the firsts of c. crocuta in the iberian peninsula do not allow to exclude an overlap in the chronological range of the two species –one of the aspect that might permit to hypothesize some sort of competition– from a biochronological point of view the arrival of galerian newcomers such as cervus elaphus, sus scrofa, and c. crocuta at gran dolina and cueva negra (earliest localities with c. crocuta) likely supports a separation from vallparadís evt7 (latest calibrated occurrence of p. brevirostris). this remark has now received further support from the revised chronological constraints for the lower levels of gran dolina (duval et al., 2022), which, among the other things, are incompatible with the previous paleomagnetic correlation for the normal polarity intervals of the unit td7 with the kamikatsura (846 ± 10 ka) and/or santa rosa (932 ± 5 ka) magnetic excursions (parés et al., 2013). the new dating constraints rather point to a correlation with the matuyama-brunhes precursor, which is not older than 794 ± 4 ka but perhaps even younger (channell et al., 2020; haneda et al., 2020; duval et al., 2022). the previous interpretation was the main reason to consider c. crocuta potentially present in europe prior 0.9 ma (e.g., martínez-navarro, 2010; palombo, 2014), as td7 overlies levels with hyaenid remains in the sequence of gran dolina. therefore, the “c. crocuta event”, as it is often referred to (martínez-navarro, 2010), likely occurred ~0.8 ma. this age is close to the earliest occurrence of c. crocuta in italy from the layer of gravels and sands of cava di breccia di casal selce, which is dated around 0.75–0.70 ma and yielded the reference fauna of the ponte galeria fu, at the beginning of the galerian european land mammal age (petronio & sardella, 1999; sardella & petrucci, 2012; strani et al., 2022). in this case, competition between hyenas hardly played a significant role in the extinction of p. brevirostris, although it might have influenced the late dispersal of crocuta in europe after its spread outside africa (iannucci et al., 2021b). however, pl. perrieri and p. brevirostris were definitely closer in craniodental morphology (and hence inferred ecology) than the giant hyena was to c. crocuta, and their remains are recovered together in some localities (iannucci et al., 2021b). even so, looking at the dimensional differences in dental measurements between the extant species (figure 5), we observed a much larger overlap than that between pl. perrieri and p. brevirostris. therefore, even considering size alone, it seems reasonable to assume that the two species were different enough to occupy different niches, not impeding their coexistence. further support for this consideration comes from the behavioral plasticity of living bone-cracking hyenas. the proportion between hunting and scavenging, diurnal or nocturnal activity, and the location of denning sites, among others, are all factors that can vary and thus facilitate coexistence between living species (kruuk, 1972; mills, 1982, 1990; wiesel, 2006). on the other hand, the “p. brevirostris event” was accompanied by an important reorganization of mammalian faunas and indeed witnessed a peak in carnivoran diversity, particularly of hypercarnivorous and ambush-hunting felids (azzaroli, 1983; palombo et al., 2008; konidaris, 2022). envisioning pl. perrieri mainly as a solitary scavenger, led to the paradox that after its extinction the “place” of a middle-sized scavenger in the carnivoran guild of the late villafranchian remained unoccupied (konidaris, 2022), which might have implications for early hominin dispersal into europe (konidaris & tourloukis, 2021; konidaris, 2022). however, few species are exclusively adapted to a specific feeding behavior and if pl. perrieri had to coexist with p. brevirostris, it likely had to deviate to a more active hunting behavior and/or to target smaller preys. at the same time, this was likely not an easy task, facing the arrivals of several new competitors. it is thus conceivable that pl. perrieri managed to maintain a place in late villafranchian carnivoran guild only for a short geological period, perhaps while other carnivorans were becoming widespread. if the evolution of p. brevirostris was a punctuated event, the likely source area would be eastern asia. indeed, the sample from longdan referred to pachycrocuta by qiu et al. (2004), is intermediate in several measurements between pl. perrieri and p. brevirostris, although somewhat closer to the former species (figure 5). further discovery and description of new (and old) material is needed to understand if a tendency towards larger dimensions occurred in other samples across eurasia, especially focusing on late samples of pl. perrieri. although the trend is not strong, chronologically younger specimens of p. brevirostris are generally larger than earlier representatives of the species, supporting the view of a progressive specialization during the evolution of the giant hyena (iannucci et al., 2021b, 2022), which might have started from the separation of p. brevirostris from pl. perrieri (werdelin & solounias, 1991), or perhaps even in some late samples of the latter species. 5. conclusions although the hyena hemimandible from paciano went lost over the years, critically revising and contextualizing the description and measurements provided by bortolotti (1905) in an updated comparative and taxo nomic framework allowed to reattribute the specimen to pl. perrieri. this species is not documented by extensive samples in italy and testifies to a relatively old age for the fossil locality, thus offering an interesting additional record in the study of early pleistocene european hyenas and underlining the importance and the feasibility of revising historical collections, even when the original remains are lost. in general, there is a relative paucity of descriptions or reconsiderations of historical samples, especially if excluding publications that change previous interpretations, as a likely consequence of the seek for “novelty” that permeates current scientific literature. here, we revised the taxonomic attribution of the paciano hyena, but we emphasize that even confirming an attribution to p. brevirostris, as proposed in the latest work mentioning this sample (argenti, 2004), would have been a significant outcome, and that confirmatory results are worth to share with the scientific community. the giant hyena p. brevirostris likely originated from a large-sized stock of pl. perrieri, but around 2.0–1.8 ma, while p. brevirostris spread into europe, some populations of pl. perrieri remained relatively small-sized and survived for a short time alongside the giant hyena. the impact of competition between extant hyaenid species is generally compensated by their behavioral plasticity, but the evolution of the specialized giant hyena on one side, and the concurrent spread of other late villafranchian carnivorans on the other, might have pushed pl. perrieri towards the limits of its ecological tolerance, eventually triggering its extinction. in any case, there are few localities that document a co-occurrence of pl. perrieri and p. brevirostris, which complicates elucidating the issue. acknowledgments the comparative sample considered here and in previous works has been examined during visiting periods in several institutions, we wish therefore to thank the curators and other personnel that supported us on such occasions, especially manuela aiglstorfer, deborah arbulla, luca bellucci, riccardo castiglia, elisabetta cioppi, andy currant, thomas engel, mihály gasparik, emmanuel gilissen, ralf-dietrich kahlke, linda riti, gerald utschig, and david waterhouse. george e. konidaris and an anonymous reviewer provided valuable comments on a previous version of this article, for which we are grateful. this research received support from the synthesys project http://www.synthesys. info which was financed by european community research infrastructure action under the fp7 “capacities” program (hu-taf-707 and be-taf-708 to rs) and the following synthesys+ project, financed by the european commission via the h2020 research infrastructure programme (de-taf-59 to ai). references agnarsson i., kuntner m. (2007) taxonomy in a changing world: seeking solutions for a science in crisis. systematic biology, 56(3), 531-539. antón m., turner a., salesa m.j., morales j. (2006) a complete skull of chasmaporthetes lunensis (carnivora, hyaenidae) from the spanish pliocene site of la puebla de valverde (teruel). estudios geológicos, 62, 375-388. alberdi m.t., palombo m.r. (2013) the late early to early middle pleistocene stenonoid horses from italy. quaternary international, 288, 25-44. argenti p. (2004) plio-quaternary mammal fossiliferous sites of umbria (central italy). geologicaromana 37, 67-78. argenti p., sardella r. (2003) early pleistocene large mammals from villa spinola (perugia, central italy). bollettino della società paleontologica italiana, 42(3), 315-321. azzarà b., breda m., cirilli o., madurell-malapeira j., ruzza f., sorbelli l., tancredi d., cherin m. (2022) vigna nuova: the first middle villafranchian mammal assemblage from the valdichiana basin, perugia (italy). bollettino della società paleontologica italiana, 61(2), 223-247. azzaroli a. (1983) quaternary mammals and the “endvillafranchian” dispersal event a turning point in the history of eurasia. palaeogeography, palaeoclimatology, palaeoecology, 44, 117-139. boaz n., ciochon r.l., xu q., liu j. (2000) large mammalian carnivores as a taphonomic factor in the bone accumulation at zhoukoudian. acta anthropologica sinica, 19 (suppl.), 224-234. bona f. (2021) new late pleistocene leopard fossils from equi (massa, italy) rediscovered in the manodori collection, musei civici reggio emilia, italy. bollettino della società paleontologica italiana, 60, 149-155. bortolotti c. (1904) denti di proboscidati, di rinoceronte di ippopotamo dell’antica collezioni canali di perugia. rivista italiana di paleontologia, 10, 83-93. bortolotti c. (1905) intorno ad un resto di mandibola di jena. rivista italiana di paleontologia, 11, 34-36. channell j.e.t., singer b.s., jicha b.r. (2020) timing of quaternary geomagnetic reversals and excursions in volcanic and sedimentary archives. quaternary science reviews, 228, 106114. cherin m. (2013) systematic, paleoecological and biochronological study of some quaternary mammal faunas from central umbria (italy). unpublished phd thesis, university of perugia, italy. cherin m., azzarà b., breda m., brobia ansoleaga a., buzi c., pandolfi l., pazzaglia f. (2019) large mammal remains from the early pleistocene site of podere san lorenzo (perugia, central italy). rivista italiana di paleontologia e stratigrafia, 125, 489-515. cirilli o., pandolfi l., bernor r.l. (2020) the villafranchian perissodactyls of italy: knowledge of the fossil record and future research perspectives. geobios, 63, 1-21. coca-ortega c., pérez-claros j.a. (2019) characterizing ecomorphological patterns in hyenids: a multivariate approach using postcanine dentition. peerj, 6, e6238. cooper r.l., skinner j.d. (1979) importance of termites in the diet of the aardwolf proteles cristatus in south africa. south african journal of zoology, 14(1), 5-8. croizet j.-b., jobert a.-c.-g. (1828) recherches sur les ossements fossiles du département du puy-de 114 iannucci a. et al. dome. clermont-ferrand, paris. crumly c.r. (1984) saving a legacy: natural history collections in germany before and after world war ii. curator: the museum journal, 27(3), 205-219. cuvier g. (1821) recherches sur les ossemens fossiles, où l’on rétablit les caractères de plusiers animaux dont les révolutions du globe ont détruit les espéces. tome 1. dufour et d’ocagne, paris & amsterdam. de giuli c. (1987) late villafranchian faunas in italy: the selvella local fauna in southern chiana valley umbria. palaeontographia italica, 74, 11-50. del campana d. (1914) la lycyaena lunensis n. sp. dell'ossario pliocenico di olivola (val di magra). palaeontographia italica, 20, 87-103. de serres m., dubreuil j., jeanjean b. (1828) mémoires sur les diverses espèces d'hyènes fossiles découvertes dans les cavernes de lunel-vieil (hérault). mémoires du museum national d'histoire naturelle, paris, 17, 269-312. duval m., arnold l.j., demuro m., parés j.m., campaña i., carbonell e., de castro j.m.b. (2022) new chronological constraints for the lowermost stratigraphic unit of atapuerca gran dolina (burgos, n spain). quaternary geochronology, 71, 101292. ercoli m.d., ramírez m.a., morales m.m., álvarez a., candela a.m. (2019) first record of carnivora (puma lineage, felidae) in the uquía formation (late pliocene–early pleistocene, nw argentina) and its significance in the great american biotic interchange. ameghiniana, 56(3), 195-212. erxleben j.c.p. (1777) systema regni animalis per classes, ordines, genera, species, varietates, cum synonymia et historia animalium. classis 1: mammalia. weygandianis, leipzig. escobar e. (2018) in a ‘foretold tragedy’, fire consumes brazil museum. science, 361(6406), 960. espigares m.p., martínez-navarro b., palmqvist p., ros -montoya s., toro i., agustí j., sala r. (2013) homo vs. pachycrocuta: earliest evidence of competition for an elephant carcass between scavengers at fuente nueva-3 (orce, spain). quaternary international, 295, 113-125. fabbi s., romano m., strani f., sardella r., bellucci l. (2021) the pleistocene vertebrate fauna of the oricola-carsoli intermontane basin (latiumabruzzi, italy): state of the art and historical review. bollettino della società paleontologica italiana, 60, 255-268. ferretti m.p. (1999) tooth enamel structure in the hyaenid chasmaporthetes lunensis lunensis from the late pliocene of italy, with implications for feeding behavior. journal of vertebrate paleontology, 19, 767-770. frank l.g. (1986a) social organisation of the spotted hyaena, crocuta crocuta. i. demography. animal behaviour, 34, 1500-1509. frank l.g. (1986b) social organisation of the spotted hyaena, crocuta crocuta. il. dominance and reproduction. animal behaviour, 34, 1510-1527. garcía n. (2003) osos y otros carnívoros de la sierra de atapuerca. fundación oso de asturias, oviedo. gervais p. (1848–1852) zoologie et paléontologie françaises. nouvelles recherches sur les animaux vivants et fossiles de la france. tome i. contenant l’énumerération méthodique et descriptive des espèces ainsi que les principes de leur distribution géographique et paléontologique. arthus bertrand, paris. godfray h.c.j. (2002) challenges for taxonomy. nature, 417(6884), 17-19. hammer ø., harper d.a.t., ryan p.d. (2001) past: paleontological statistics software package for education and data analysis. palaeontologia electronica, 4, 4. haneda y., okada m., suganuma y., kitamura t. (2020) a full sequence of the matuyama– brunhes geomagnetic reversal in the chiba composite section, central japan. progress in earth and planetary science 7, 44. holekamp k.e., smith j.e., strelioff c.c., van horn r.c., watts h.e. (2012) society, demography and genetic structure in the spotted hyena. molecular ecology, 21(3), 613-632. howell f.c., petter g. (1980) the pachycrocuta and hyaena lineages (plio-pleistocene and extant species of the hyaenidae). their relationships with miocene ictitheres: palhyaena and hyaenictitherium. geobios, 13, 579-623. iannucci a., cherin m., sorbelli l., sardella r. (2021a) suidae transition at the miocene-pliocene boundary: a reassessment of the taxonomy and chronology of propotamochoerus provincialis. journal of mammalian evolution, 28(2), 323-335. iannucci a., mecozzi b., sardella r., iurino d.a. (2021b) the extinction of the giant hyena pachycrocuta brevirostris and a reappraisal of the epivillafranchian and galerian hyaenidae in europe: faunal turnover during the early–middle pleistocene transition. quaternary science reviews, 272, 107240. iannucci a., mecozzi b., sardella r. (2021c) large mammals from the middle pleistocene (mis 11) site of fontignano 2 (rome, central italy), with an overview of “san cosimato” assemblages. alpine and mediterranean quaternary, 34(1), 155-164. iannucci a., mecozzi b., kalhke r.-d., sardella r. (2022) new results on hyaenids from the early pleistocene site of untermassfeld. in: the pleistocene of untermassfeld near meiningen (thüringen, germany). part 5 (ed. by kahlke r.-d.), monographien des römisch-germanischen zentralmuseums 40(5), 1403-1422. iurino d.a., iannucci a., conti j., mecozzi b., sardella r., strani f. (2022) revised description of the late miocene hyaenictitherium namaquensis (carnivora, hyaenidae) from as sahabi (north africa, libya). historical biology, 34(8), 1373-1380. jungers w.l., falsetti a.b., wall c.e. (1995) shape, relative size, and size-adjustments in morphometrics. yearbook of physical anthropology, 38, 137161. kolowski j.m., katan d., theis k.r., holekamp k.e. (2007) daily patterns of activity in the spotted hyena. journal of mammalogy, 88(4), 1017-1028. 115 the lost hyena from paciano konidaris g.e., tourloukis v. (2021) proboscideahomo interactions in open-air localities during the early and middle pleistocene of western eurasia: a palaeontological and archaeological perspective. in: human-elephant interactions: from past to present (ed. by konidaris g.e., barkai r., tourloukis v., harvati k.). tübingen university press, tübingen, 67-104. konidaris g.e. (2022) guilds of large carnivorans during the pleistocene of europe: a community structure analysis based on foraging strategies. lethaia, 52(2), 1-18. koufos g.d. (2021) the late miocene middle-sized ictitheres (mammalia: hyaenidae) of greece. bollettino della società paleontologica italiana, 60(1), 19-48. kretzoi m. (1938) die raubtiere von gombaszög nebst einer übersicht der gesamtfauna. annales historico-naturales musei nationalis hungarici, 31, 88157. kruuk h. (1972) the spotted hyaena: a study of predation and social behavior. university of chicago press, chicago. kruuk h, sands w.a. (1972) the aardwolf (proteles cristatus sparrman) 1783 as predator of termites. african journal of ecology, 10(3), 211-227. kurtén b. (1956) the status and affinities of hyaena sinensis owen and hyaena ultima matsumoto. american museum novitates, 1764, 1-48. kurtén b. (1968) pleistocene mammals of europe. weidenfeld and nicolson, london. kurtén b., werdelin l. (1988) a review of the genus chasmaporthetes hay, 1921 (carnivora, hyaenidae). journal of vertebrate paleontology, 8, 46-66. lewis m.e., werdelin l. (2010) carnivoran dispersal out of africa during the early pleistocene: relevance for hominins? in: out of africa i: the first colonization of eurasia (ed. by fleagle j.g., shea j.j., grine f.e., baden a.l., leakey r.e.), vertebrate paleobiology and paleoanthropology. springer netherlands, dordrecht,13-26. lewis m.e., werdelin l. (2022) a revision of the genus crocuta (mammalia, hyaenidae). abteilung a, palaozoologie, stratigraphie, 322(1-4), 1-115. linnaeus c. (1758) systema naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. tomus i. editio decima, reformata. laurentius salvius, stockholm. liu j., liu j., zhang h., wagner j., jiangzuo q., song y., liu s., wang y., jin c. (2021) the giant short -faced hyena pachycrocuta brevirostris (mammalia, carnivora, hyaenidae) from northeast asia: a reinterpretation of subspecies differentiation and intercontinental dispersal. quaternary international 577, 29-51. madurell-malapeira j., alba d.m., espigares m.p., vinuesa v., palmqvist p., martínez-navarro b., moyà-solà s. (2017) were large carnivorans and great climatic shifts limiting factors for hominin dispersals? evidence of the activity of pachycrocuta brevirostris during the mid-pleistocene revolution in the vallparadís section (vallèspenedès basin, iberian peninsula). quaternary international, 431, 42-52. makel m.c., plucker j.a. (2014) facts are more important than novelty: replication in the education sciences. educational researcher, 43(6), 304-316. marciszak a., gornig w., kropczyk a., rössner g.e. (2022) the latest european record of chasmaporthetes lunensis lunensis (del campana, 1914) from schernfeld (bavaria, germany) in terms of the changes in the european carnivore paleoguilds. stratigraphy & timescales. doi: 10.1016/bs.sats.2022.09.003 martinetto e., bertini a., basilici g., baldanza a., bizzarri r., cherin m., gentili s., pontini m.r. (2014) the plant record of the dunarobba and pietrafitta sites in the plio-pleistocene palaeoenvironmental context of central italy. alpine and mediterranean quaternary, 27, 29-72. martínez-navarro b. (2010) early pleistocene faunas and hominin dispersals. in: out of africa i: the first colonization of eurasia (ed. by fleagle j.g., shea j.j., grine f.e., baden a.l., leakey r.e.), vertebrate paleobiology and paleoanthropology. springer netherlands, dordrecht, 207-224. mecozzi b., iannucci a., mancini m., sardella r. (2021) redefining ponte molle (rome, central italy): an important locality for middle pleistocene mammal assemblages of europe. alpine and mediterranean quaternary, 34(1), 131-154. mecozzi b., iannucci a., bona f., mazzini i., pieruccini p., sardella r. (2022) rediscovering lutra lutra from grotta romanelli (southern italy) in the framework of the puzzling evolutionary history of eurasian otter. palz, 96(1), 161-174. mills m.g.l. (1982) factors affecting group size and territory size of the brown hyaena, hyaena brunnea, in the southern kalahari. journal of zoology london 198, 39-51. mills m.g.l. (1990) kalahari hyenas: the comparative behavioral ecology of two species. chapman & hall, london. mosimann j.e. (1970) size allometry: size and shape variables with characterizations of the lognormal and gamma distributions. journal of the american statistical association, 65, 930-945. mosimann j.e., james f.c. (1979) new statistical methods for allometry with applications to florida red-winged blackbirds. evolution, 23, 444-459. palmqvist p., martínez-navarro b., pérez-claros j.a., torregrosa v., figueirido b., jiménez-arenas j.m., patrocinio espigares m., ros-montoya s., de renzi m. (2011) the giant hyena pachycrocuta brevirostris: modelling the bone-cracking behavior of an extinct carnivore. quaternary international 243, 61-79. palombo m.r. (2014) deconstructing mammal dispersals and faunal dynamics in sw europe during the quaternary. quaternary science reviews, 96, 5071. palombo m.r., sardella r., novelli m. (2008) carnivora dispersal in western mediterranean during the last 2.6 ma. quaternary international, 179, 176 -189. 116 iannucci a. et al. pandolfi l., kotsakis t. (2017) a mandible of tapirus arvernensis from central italy. italian journal of geosciences, 136 (1), 136-138. pape t., aescht e., ahyong s.t., ballerio a., bertling m., bogutskaya n.g., bouchard p., bourgoin t., dmitriev d., evenhius, n.l., grygier, m.j., halliday, r.b., harvey m.s., kojima j., kottelat m., krell f.-t., kullander s.o., lamas g., lyal c.h.c., pyle r., rheindt f.e., rosenbrg g., welterschultes f., winston j.e., yanega d., zhang z.-q., zhou h.-z. (2018) re: rio de janeiro museum fire: what to do about the massive loss of type specimens? science, eletter (27 september 2018). doi: 10.1126/science.361.6406.960 parés j.m., duval m., arnold l.j. (2013) new views on an old move: hominin migration into eurasia. quaternary international, 295, 5-12. petronio c., sardella r. (1999) biochronology of the pleistocene mammal fauna from ponte galeria (rome) and remarks on the middle galerian faunas. rivista italiana di paleontologia e stratigrafia, 105, 155-164. pérez-claros j.a., coca-ortega c., werdelin l. (2021) how many hyenas in north america? a quantitative perspective, journal of vertebrate paleontology, 41(3), e1979988. qiu z. (1987) die hyaeniden aus dem ruscinium und villafranchium chinas. münchner geowissenschaftliche abhandlungen reihe a: geologie und paläontologie, 9, 1-108. qiu z., deng t., wang b. (2004) early pleistocene mammalian fauna from longdan, dongxiang, gansu, chian. palaeontologica sinica, n. ser. c, 27, 1-198. sardella r., petrucci m. (2012) the earliest middle pleistocene crocuta crocuta (erxleben, 1777) at casal selce (rome, italy). quaternary international, 267, 103-110. semenov y. (2008) taxonomical reappraisal of “ictitheres” (mammalia, carnivora) from the late miocene of kenya. comptes rendus palevol, 7(8), 529-539. sorbelli l., villa a., gentili s., cherin m., carnevale g., tschopp e., delfino m. (2021) the early pleistocene ectothermic vertebrates of pietrafitta (italy) and the last western european occurrence of latonia meyer, 1843. comptes rendus palevol, 20, 555-583. sparrmann a. (1783) resa till goda hopps-udden södra polkretsern och omkringjordklotet samt till hottentottoch caffer-landern åren. band i. anders j. nordstörm, stockolm, 1772-1776. stiner m.c. (1991) the faunal remains from grotta guattari: a taphonomic perspective. current anthropology, 32, 103-117. strani f., bellucci l., iannucci a., iurino d.a., mecozzi b., sardella r. (2022) palaeoenvironments of the mis 15 site of cava di breccia-casal selce 2 (central italian peninsula) and niche occupation of fossil ungulates during middle pleistocene interglacials. historical biology, 34(3), 555-565. thunberg c.p. (1820) beskrifning och teckning på etr nytt species, hyaena brunnea. kungliga svenska vetenskapsakademiens handlingar för år, 1, 5965. tseng z.j., antón m., salesa m.j. (2011) the evolution of the bone-cracking model in carnivorans: cranial functional morphology of the pliopleistocene cursorial hyaenid chasmaporthetes lunensis (mammalia: carnivora). paleobiology, 37, 140-156. tseng z.j., li q., wang x. (2013) a new cursorial hyena from tibet, and analysis of biostratigraphy, paleozoogeography, and dental morphology of chasmaporthetes (mammalia, carnivora). journal of vertebrate paleontology, 33(6), 1457-1471. tuccimei g. (1895) sopra i resti fossili di mammiferi trovati alla villa spinola presso perugia. atti dell’accademia pontificia dei nuovi lincei, 48, 4446. turner a., antón m. (1996) the giant hyaena pachycrocuta brevirostris (mammalia, carnivora, hyaenidae). geobios, 29, 455-468. turner a., antón m., werdelin l. (2008) taxonomy and evolutionary patterns in the fossil hyaenidae of europe. geobios, 41, 677-687. viret j. (1954) le loess à bancs durcis de saint-vallier (drôme) et sa faune de mammifères villafranchiens. nouvelles archives du muséum d’histoire naturelle de lyon, 4, 1-200. werdelin l., solounias n. (1991) the hyaenidae: taxonomy, systematics and evolution. fossils and strata 30, 1-104. werdelin l., solounias n. (1996) the evolutionary history of hyaenas in the miocene of europe and western asia. in: the evolution of western eurasian neogene mammal faunas (ed. by bernor r.l., fahlbusch v., mittmann h.-w.), columbia university press, new york, 290-306. werdelin l., lewis m.e. (2008) new species of crocuta from the early pliocene of kenya, with an overview of early pliocene hyenas of eastern africa. journal of vertebrate paleontology, 28, 11621170. wiesel i. (2006) predatory and foraging behaviour of brown hyenas (parahyaena brunnea (thunberg, 1820)) at cape fur seal (arctocephalus pusillus pusillus schreber, 1776) colonies. unpublished phd thesis. university of hamburg, germany. 117 the lost hyena from paciano ms. received: november 30, 2022 revised: december 6, 2022 accepted: december 6, 2022 available online: december 16, 2022 118 impaginato atti tthhee tt’’oorraa ggeeoossooll((??)) ((mmaaiinn eetthhiiooppiiaann rriifftt,, eetthhiiooppiiaa)):: pprroobblleemmss iinn ddeeffiinniinngg ppaallaaeeoossoollss ss.. ccaarrnniicceellllii**,, mm.. bbeennvveennuuttii11,, ff.. bboonnaaiiuuttii,, cc.. iiaassiioo,, dd.. ssaaggrrii,, aa.. mmiirraabbeellllaa22,, mm.. ssaaggrrii11,, gg..aa.. ffeerrrraarrii,, gg.. bbeelllluuoommiinnii33 && uu.. wwoollff *corresponding author, tel. +39 055 3288398, fax +39 055 333273, e-mail carnic@iges.fi.cnr.it 1dipartimento di scienze della terra, firenze, italy 2istituto sperimentale per lo studio e la difesa del suolo, mipaf, firenze, italy 3istituto tecnologie applicate ai beni culturali, c.n.r., roma, italy summary the lake region (main ethiopian rift, mer), is object of major palaeoenvironmental research since the seventies. an integrated soil and late quaternary stratigraphy study in this area revealed the presence, across a wide range of present soil-forming factors, of a group of soils sharing major common features, including: intense smectite neoformation from clay-free parent materials a strongly developed petrocalcic horizon a fairly uniform tephra addition, making them pedocomplexes with two well defined compartments in the mer lower elevation areas, these soils, found on lake ziway terrace v, are incompatible with the present semiarid climate. a major pedogenetical hiatus separates them from those developed on the next oldest terrace, iv, last flooded about 5 14c ky bp. these soils were chronologically placed with respect to the known palaeoclimatic history of the mer, with the help of a newly described and dated stratigraphic section. there is multiple evidence that they developed during the holocene climatic optimum, between 10 and 5 c14 ky bp, when proxy records show for the area a climate moister than present. the wide spread of these soils, their easy field recognition and the importance of early holocene in the palaeoenvironmental history of the mer prompted their use as a key level. as such, they showed to be extremely useful in the interpretation of the geomorphic and sedimentary evolution of the lake region. specifically, they were used in reconstructing phases of landscape stability and instability throughout terminal pleistocene and holocene. such importance and usefulness suggested their possible establishment as a pedostratigraphic unit, a geosol, giving birth to the t’ora geosol definition. however, according to current standards, existing or in discussion, basic problems exist. the t’ora geosol cannot yet be formalized as, in its present reference stratigraphy, it is not buried. a suitable stratotype has been located but not yet described. furthermore, the t’ora geosol is mostly relic, and rarely exhumed, in its surface occurrences. according to the present version of the inqua palaeopedology glossary, the t’ora geosol cannot be defined a palaeosol, as it formed in holocene. consensus palaeoclimatic and chronological frameworks for many tropical areas, however, consider holocene climatic variations to be of a similar order of magnitude of those registered throughout late pleistocene. it appears then rather arbitrary, at least for intertropical areas, to limit the palaeosol concept to the pleistocene when, as shown by our findings, holocene soils may be as useful, or more useful, than older soils in palaeoenvironmental reconstructions. riassunto la regione dei laghi (main ethiopian rift, mer), è oggetto di ricerche paleoambientali dagli anni settanta. un rilevamento integrato dei suoli e dei depositi del tardo quaternario dell’area ha mostrato la presenza di un gruppo caratteristico di suoli definiti da alcuni caratteri principali, comprendenti: estesa neoformazione di smectite da un parent material privo di fillosilicati un orizzonte petrocalcico fortemente sviluppato una deposizione generalizzata di tephra, che li rende dei pedocomplessi con due membri ben definiti alle quote più basse della mer questi suoli, trovati ad esempio sul v terrazzo del lago ziway, non sono compatibili con il clima attuale, semiarido. un forte divergenza di processi genetici li separa dai suoli del terrazzo immediatamente più recente, il iv, la cui età potrebbe raggiungere i 5000 anni 14c bp. questi suoli sono stati collocati cronologicamente, rispetto alla storia quaternaria nota della mer, con l’aiuto di una sezione statigrafica di nuova descrizione, corredata da datazioni. evidenze multiple consentono di datarne la formazione tra 10000 e 5000 anni 14c bp, durante l’optimum climatico olocenico, per il quale i proxy record esistenti suggeriscono un clima più umido dell’attuale. l’ampia diffusione di questi suoli, il loro facile riconoscimento in campagna e l’importanza dell’olocene inferiore nell’area hanno suggeil quaternario italian journal of quaternary sciences 1155(1), 2002, 105-110 iinnttrroodduuccttiioonn the lake region (main ethiopian rift, mer, fig. 1), is characterized by recent intense tectonic and volcanic activity, and marked climate changes. the presence of an endoreic lacustrine system made the area highly suitable for palaeoclimatic reconstructions based on lake levels. the first comprehensive reconstruction of holocene lakes level fluctuations is due to street (1979), also basing on previous work by haynes and haas (1974), geze (1975) and laury and albritton (1974, 1975). chronology was refined by gillespie et al (1983), while more details and a general revision were presented by alessio et al. (1996). the present state of knowledge is summarized in the diagram of fig. 2. the most conspicuous features are the rapid oscillations of the first half of holocene, when lake levels were often much higher then present. the last, and major, high stand occurred about 5 14c ky bp, after which a general declining trend set in. an outstanding finding of an integrated soil survey and late quaternary evolution study in this area was the presence, over a wide range of parent materials, morphological positions and present climates, of a group of soils sharing major common features. provisionally and informally, these soils are defined as the t’ora soil type. the placement of this soil type within current concepts of palaeosol definition presents unusual problems and a sort of a challenge to presently used or proposed definitions, and is the main subject of this paper. aarreeaa ggeeooggrraapphhyy aanndd mmeetthhooddss the mer floor, in the lake region, has a typical elevation of around 1.600-1.700 m a.s.l., but is not uniformly flat; the alutu volcano rises for about 700 m, while the gademota ridge, remnant of a large caldera 106 s. carnicelli et al. rito il loro uso come livello guida. come tale, essi si sono mostrati di grande utilità nell’interpretazione dell’evoluzione stratigrafica e geomorfica della regione dei laghi, e in particolare nella ricostruzione delle fasi di stabilità e instabilità geomorfica attraverso il pleistocene terminale e l’olocene. una tale utilità suggerisce il loro uso come unità pedostratigrafica, un geosol, dando luogo alla definizione del t’ora geosol. tuttavia, gli standard correnti, o in discussione, pongono dei problemi di fondo. il t’ora geosol non può, al momento, essere formalizzato poichè, nella attuale stratigrafia di riferimento, non è sepolto. in ogni caso, questo suolo è assai più frequente ed utile in forma relitta che non sepolta. in base alla versione attualmente in circolazione del glossario inqua di paleopedologia, il t’ora geosol non può essere definito un paleosuolo, essendo datato all’olocene. tuttavia, le ricostruzioni paleoclimatiche generalmente accettate per le aree tropicali evidenziano variazioni climatiche, durante l’olocene, dello stesso ordine di grandezza registrato in generale attraverso il tardo pleistocene. sembra quindi piuttosto arbitrario, almeno per le aree tropicali, limitare il concetto di paleosuolo all’olocene quando, come dimostrato dai nostri risultati, suoli olocenici possono avere altrettanto o più valore dei suoli pleistocenici per le ricostruzioni paleoambientali. key-words: palaeosols, holocene, palaeoenvironment reconstruction, main ethiopian rift, ethiopia parole chiave: paleosuoli, olocene, ricostruzione paleoambientale, main ethiopian rift, etiopia fig. 1 location map and general geographical features of the area 107the t’ora geosol ... (1978) studied a transect of soils across five lacustrine terraces. these had been identified by laury and albritton (1975) and street (1979) to the west of lake ziway, and numbered i to v from the lowest to the highest. verheye (1978) noted the very strong contrast between the soils on terraces i-iv, relatively little differentiated among themselves, and the starkly more evolved soil on terrace v. according to absolute datings by laury and albritton (1975), terrace i-iv are of holocene age, iv having been last flooded during the 5 14c ky bp high stand, while terrace v is considered (street, 1979) of generic pleistocene age. the main contrast was given by the limited weathering of glassy materials, still dominating soil fabric in terraces i-iv, and the huge amount of pedogenic clays formed within the soil of terrace v. very large forms of catastrophic erosion, like gullies and badlands, are prominent throughout the area, representing a major threat to natural resources and local economy. these landforms are nor completely neither easily understood, and are a primary subject of ongoing work. the whole area was mapped according to land system principles, basing on both aerial photographs and landsat tm images. extensive, integrated, field surveys were led during 4 years for geology, soils and land cover/use. soil survey, in particular, entailed description of 106 complete soil profiles, more than half of which were analysed. geological sections through late quaternary deposits were described, suitable materials being dated by both radiometric and ams 14c techniques. in this paper, anyway, only those stratigraphic aspects relevant to the t’ora soil type are considered. rreessuullttss the t’ora soil (fig. 3, table 1) is essentially a relic soil. buried exposures are few and not yet completely studied. its most relevant common properties are: neoformation of large amounts of smectites from parent materials dominated by volcanic glass and essentially clay-free. presence of a strongly developed petrocalcic horizon, normally found below 150 cm and always below 100 cm. presence of a fairly uniform recent tephra addition, making them pedocomplexes (morrison, 1977) with two clearly identifiable soils. the upper soil of the pedocomplex, t’ora a, developed from the recent tephra; it is quite homogeneous in texture and weathering degree, as evaluated from clay mineralogy, strongly suggesting that the recent tephra represents a single volcanic phase in a narrow time interval. the recent tephra then gives to the t’ora soil a unique chronological significance, in the sense that the lower soil must have been the surface soil in a specific moment of time. unfortunately, the recent tephra is too weathered for direct dating by irsl or fig. 2 holocene oscillations of mer lakes levels according to gillespie et al. (1983). sd indicates shala datum, i.e. level of lake shala as surveyed by street (1979); roman numerals indicate ziway-shala lacustrine phases. (laury & albritton, 1975), forms an arc structure 20 km in diameter, rising up to 400 m above the plain. west of the gademota relief an extended flat ridge, about 5 km wide, stretches nne-ssw for 80 km, rising up to 2.000 m a.s.l. it is formed by a series of uplifted and/or tilted blocks, making up an horst system that separates the main mer floor from the rift-in-rift depression of the abay-golel’sha lakes. the area can then be divided in two main physiographic sections: the horst system and the mer bottom. this last is rather dry: at ziway, average annual rainfall is around 700 mm, temperature 18°c and temperature regime isothermic; areas around lakes abiyata and langano are probably drier. in the horst system, yearly rainfall varies instead between 900 and 1000 mm, and temperatures are somewhat lower. huge volumes of pyroclastic materials, mainly peralkaline rhyolitic ignimbrites, extend on most of the mer (woldegabriel et al., 1990). in the valley bottom they are covered by fluvio-lacustrine sediments, whose terrigenous component is dominated by pyroclastic materials. these sediments were laid down in a very wide lake which, in some late pleistocene intervals and again in early holocene, occupied most of the mer floor (street, 1979); the four present-day lakes are the remnants of that ancient lacustrine basin. the lake region is crossed by two belts of recent tectonic deformation, trending ssw-nne: the siltidebre zeit fault zone (sdzfz) to the west and the wonji fault belt (wfb) to the east (di paola, 1972; woldegabriel et al., 1990). these belts consist of hundreds of steep normal faults, forming grabens, half-grabens and fault-bounded blocks. the sdzfz is 5-10 km wide and 80 km long, with very recent basalt effusions, dated 0.13 myr to present (woldegabriel et al., 1990). in a previous pedological investigation, verheye similar techniques. basically, t’ora a soil is characterized by a mollic horizon, whose thickness varies significantly in agreement with morphological position, as a result of some redistribution by slope processes. profiles observed in the western part of the area often show a moderately thick argic horizon. consequently, the upper soil is either an haplic, a pachi-haplic or a luvic phaeozem. a striking field reconnaissance feature is the c horizon. pale grey in colour and slightly cemented by silica, this horizon protrudes in natural sections, where it clearly stands out. the clay fraction of the t’ora a soil is characterized by poorly ordered smectites, representing the weathering product of the ashy materials; kaolinite is also present, as a weathering product of the sanidine component of the parent material. clay content is below 30%, so that smectites do not express themselves in vertic characters, hampered by the very different physical behaviour of the less weathered ashes. the lower soil of the pedocomplex, t’ora b, developed from a great variety of parent materials: saprolite from the rift floor ignimbrites; slope and alluvial fan deposits flanking the major relief reworked pyroclastics of the gademota formation (laury and albritton, 1975, the t’ora soil is at the top) the lacustrine deposits of ziway lake terrace v (verheye, 1978) air-fall tephras over terrace v, related to the abernosa pumice member of street (1979). notwithstanding this variety, the t’ora b soil has fairly homogeneous characters. it has a very thick argic horizon, homogeneous in clayey texture and mineralogy but vertically differentiated in other characters. the upper subhorizon (2btb1) is black, with medium to coarse prismatic structure, cracks and thick clay coatings; it is subacid. underlying subhorizons (2btb, 2bc) are reddish brown (7.5 yr), with fine angular blocky structure, plentiful pressure faces and thin, though continuous, clay coatings; they are often subalkaline, with esp between 6 and 14. main lateral variations concern total thickness, vertic features and petrocalcic horizon expression. thickness is mostly linked to parent material, the deepest sola being found on slope deposits. vertic features appear in the lower part of the btb1, and are associated with morphological position in a complex way. they are typical and strongly expressed, with sphenoid structure, in the largest depressions to the east of the horst hills; they are not normally found, instead, in the local grabens inside the horst system. the local grabens actually have more relief energy than the larger depressions, and presently experience more dramatic shifts in hydrological conditions. morphology of the petrocalcic horizon is linked to parent material, but in the south-western area, the moister one, this horizon grades into a calcic with large, hard concretions. calcic and petrocalcic horizons are not found in any other soil of the surveyed area. t’ora b soil classifies as a hyposodic vertic or profondic hyposodic luvisol. use of the soil taxonomy allows sometimes to express the petrocalcic horizon, and some pedons classify as petrocalcic paleustalf, but most sort out as typic paleustalf; vertic subgroups cannot be defined in buried soils according to the soil taxonomy. cchhrroonnoollooggyy in the mer bottom, the t’ora soil is incompatible with the present semiarid climate. in this area, it is found on terrace v of lake ziway; a major pedogenetical hiatus, first described by verheye (1978), and confirmed by our survey, separates it from soils on the lower terraces, represented by phaeozems or cambisols. chronological placing of the t’ora soil is presently based on multiple stratigraphical, geomorphological and palaeoclimatic evidence. a stratigraphic section in the colluvial apron of the gademota ridge (fig. 4) clarified several ambiguities. lacustrine sediments dated 30 14c ky bp mark, given their elevation, the most recent known date for flooding of lake ziway terrace v, but a successive and higher, as yet undated, lacustrine phase appears. the t’ora soils on terrace v cannot then have 108 s. carnicelli et al. fig. 3 a t’ora soil profile; in this particular observation, the upper soil of the pedocomplex is a stable phase (luvic phaeozem); the lower soil shows some vertic features (slickensides), just to right of letter b). a) upper soil; b) lower soil; c) petrocalcic horizon 109 started developing before 30 14c ky bp, and possibly much later. age of lake ziway terrace iv is well known (laury and albritton, 1975; street, 1979; gillespie et al., 1983); it was last flooded about 5 14c ky bp. in the gademota section, the t’ora soils are found on top of the oldest vertical sequence of sediments, and presently at the surface. two strong erosional unconformities follow; deposits above the second unconformity were dated about 4600 14c y bp. on the surface represented by the top of the deposits between the two unconformities, a well developed luvisol is visible. it is clearly differentiated with respect to the t’ora soil, as it lacks both the petrocalcic horizon and the tephra addition. the same luvisol is found directly burying the whole t’ora soil pedocomplex in another section in the abay basin, to the west; this section is presently only dated and studied for the very recent part. soils above the second unconformity in the gademota section are never more developed than cambisols or phaeozems. in all other cases, when the t’ora soil is found over dated deposits, these are always known to be of pleistocene, and never of holocene, age. there is then multiple evidence that the t’ora soil developed on the geomorphic surfaces existing after the very aggressive erosional phase corresponding with the last glacial maximum and the terminal pleistocene, when climate in this area is known to have been semidesertic (gasse and street, 1978). this is supported by the evidence that t’ora soil formed over very extensive, complex colluvial and alluvial fan buildings around the major relief. the t’ora soil is then presently understood to have formed during the holocene climatic optimum, between 10 and 5 ky bp, when climate in the area is known to have been quite moister than present. ssttrraattiiggrraapphhiicc aanndd ppaallaaeeooeennvviirroonnmmeennttaall ssiiggnniiffiiccaannccee the wide spread of the t’ora soil, its easy field recognition and the importance of early holocene in the palaeoenvironmental history of the area prompted its use as a key level. as such, the t’ora soil was extremely useful in the interpretation of the geomorphic evolution and of undated sedimentary successions in the lake region. specifically, it was of great help in reconstructing phases of landscape stability and instability throughout late pleistocene and holocene. there are several reasons to interpret variations in t’ora b as expressions of a limited amount of lateral, sin-pedogenetic (“pedofacies”), differentiation. vertic features expression resemble a catenary sequence, weak and inconsistent with respect to present relief. inconsistency is reconciled by reconstructions of recent tectonic activity, according to which relief, in the horst system, has been enhanced in late holocene by dislocations along riftwise fault swarms. slope processes taking place in consequence of this relief rejuvenation are instead well marked in the lateral differentiation of t’ora a, the present surface soil in this phase. t’ora a can clearly be divided in stable (argic phaeozems), eroded (haplic phaeozems) and cumulic (pachi-haplic phaeozems) phases, perfectly consistent with present slopes in the horst system. expression of the petrocalcic horizon varies consistently with the modern rainfall gradient. in the mer such gradients, however, are controlled by the orographic influence of the main escarpments, and their geographic structure should not have varied greatly during the late quaternary, except for changes in absothe t’ora geosol ... fig. 4 summary of the gademota north stratigraphic section, with datings lute rainfall values and intensity of the gradient itself. the present distribution of the t’ora soils leads, in fact, to suspect that, in moister holocene intervals, the gradient ought have been less intense than at present. this is suggested by the very limited differences between t’ora soil occurrences in the presently dry mer bottom and in the presently moister horst hills. the early holocene increase in rainfall appears then to have been greater in the central than in the side portions of the mer bottom. such kind of differentiation of early holocene from modern climate is also expressed by the huge pedogenetic hiatus separating the t’ora soil from soils on ziway terrace iv, while a much lesser hiatus is evident in the presently moister areas. matching the occurrence of the t’ora soil with observed landforms, clear phases can be distinguished in the geomorphic evolution of the area. the late pleistocene was marked by the build-up of massive colluvial aprons and alluvial fans, smoothing the links between high-lying and depressed areas. these surfaces, covered by the t’ora soil, have undergone a complex holocene evolution. most colluvial aprons underwent multiple cycles of incision and filling up of large, gully-like channels. alluvial fans apparently remained quite stable until recent times, when, in most cases, the build-up of an upper storey, burying the t’ora soil surface, is observed. recent tectonic activity in the horst system has instead consistently brought about the partial destruction of the t’ora soil surface and the build-up of complex response colluvial aprons at the base of the escarpments. ddiissccuussssiioonn the use that could be made of the t’ora soil in studying the late quaternary history of the area would suggest its definition as a pedostratigraphic unit, a geosol (morrison, 1977), giving birth to the t’ora geosol definition. however, checking definitions with current, existing or in discussion, standards revealed basic problems. according to nacsn (1983), the t’ora geosol cannot presently be formalized as, in its present reference stratigraphy (the gademota section), it is not buried. a suitable stratotype (the abay section) has been located but not yet fully described and dated. however, the t’ora geosol is mostly relic, and rarely exhumed, in its surface occurrences, so it is questionable whether it would satisfy the nacsn requirements even after description of an adequate stratotype. according to the present draft of the inqua palaeopedology glossary, the t’ora soil cannot be defined a palaeosol, because it formed in holocene. the consensus palaeoclimatic and chronological framework for this area, as for many other tropical areas, considers the holocene as far from a homogeneous period. it is agreed that climatic variations during the last 10k years are of a similar order of magnitude to those registered throughout late pleistocene, with the only exception of the glacial maximums. it appears then rather unsatisfactory, at least for intertropical areas, to limit the palaeosol concept to the pleistocene when, as shown by our findings, holocene soils may be as useful, or more useful, than older soils in palaeoenvironmental reconstructions. generally speaking, excess formalism in definitions appears disadvantageous in a field like quaternary sciences, where totally new findings and paradigm upset are the order of the day. aacckknnoowwlleeddggeemmeennttss this work was funded by italian ministry for university and scientific research, under prin 1999 “risposta geomorfica ai cambiamenti ambientali in aree ad alta crescita demografica (rift etiopico)”. rreeffeerreenncceess alessio, m., allegri, l., belluomini, g., benvenuti, m., cerasoli m., improta, s., manfra, l., sagri, m. and ventra, d. (1996). le oscillazioni tardo-quaternarie del lago shala (rift etiopico): analisi dell'evoluzione ambientale dall'integrazione di evidenze morfologiche, sedimentarie e cronologiche. il quaternario, 9, 387-392. di paola, g.m. (1972). the ethiopian rift valley (between 7° 00' and 8°40' lat. north). bull. vulcanol., 36, 517-560. gasse, f. and street, f.a. (1978). late quaternary lake-level fluctuations and environments of the northern rift valley and afar region (ethiopia and djibouti). pal., pal., pal., 24, 279-325. geze, f. (1975). new dates on ancient galla lake levels. bull. geophys. obs. addis ababa 15, 119-124. gillespie, r., street-perrot, a.f. and switsur, r. (1983). post-glacial arid episodes in ethiopia have implications for climate prediction. nature, 306, 680-683. haines, v. and haas, h. (1974). southern methodist university radiocarbon date list. radiocarbon, 16, 368-380. laury, r.l. and albritton, c.c. (1974). geology. in: wendorf, f. and schild r. (eds.): a middle stone age sequence from the central rift valley, ethiopia. polish acad. sci., warsaw, 252 pp. laury, r.l. and albritton, c.c. (1975). geology of the middle stone age archaeological sites in the main ethiopian rift valley. geol. soc. am. bull., 86, 999-1011. morrison, r.b. (1977). quaternary soil stratigraphy, concepts, methods and problems. in: mahaney, w.c. (ed.): quaternary soils, pp. 77-108. geoabstracts, norwich. north american commission on stratigraphic nomenclature (nacsn) (1983). north american stratigraphic code: american assoc. petroleum geologists bull. 67, 5, 841-875. street, f.a. (1979). late quaternary lakes in the ziwayshala basin, southern ethiopia. unpublished ph.d. thesis, univ. cambridge, 457 pp. verheye, w. (1978). soils and soil evolution on the holocene lacustrine terraces of lake zway, rift valley, ethiopia. pedologie, 28, 21-45. woldegabriel, g., aronson, j and walter, r.c. (1990). geology, geochronology and rift basin development in the central sector of the main ethiopian rift. geol. soc. am. bull., 102, 439-458. 110 s. carnicelli et al. ms. ricevuto marzo 2002 ms. received: march 2002 imp.lirer& proposta di geositi nel quadro di una nuova cartografia geologica dei campi flegrei lucio lirer1, paola petrosino1 & valentina armiero2 1dipartimento di scienze della terra università degli studi di napoli federico ii, largo s. marcellino 10, 80138, napoli. e-mail : <lirer@unina.it> 2dottorato di ricerca in analisi dei sistemi ambientali, c.i.r.am, università degli studi di napoli federico ii, via mezzocannone 16, 80134, napoli abstract: l. lirer, p. petrosino & v. armiero, a proposal of some geosites in the framework of a new geological map of campi flegrei. with the aim of drawing a new geological map in scale 1:10.000, the detailed geological survey of a large area of campi flegrei, from procida up to the sebeto valley, was carried out in the last years. in this area we highlighted some geological sites that can be considered potential geosites due to rarity, scientific, educational and historical value. particularly, we pointed out: the breccia-piperno formation, cropping out in the soccavo-pianura area, which represents one of the most ancient products of the phlegrean history; the solfatara, for centuries utilized as a mine, today is one of the principal monitoring center of campi flegrei and with its vapours testifies the phlegrean activity; the monte di cuma, seat of the first greek colony in italy and rich of greek-roman archaeological remains; the averno lake, which in roman age was an inner sea connected to cuma by the viadotto of cocceio; the monte nuovo, a testimony of the only historical eruption of campi flegrei, occurred in 1538, which completely modified the geography of this area. the authors believe that these geosites, thanks to their singular geological and historical-cultural value, satisfy all the requirements necessary to form, within the regional park of campi flegrei, the first volcanological european park: the european geopark of campi flegrei. the connection between the geosites is guaranteed by present roads and, where possible, by roman tunnels caved in ancient times for military aims. parole chiave: campo vulcanico, depositi piroclastici, geosito, geoparco, campi flegrei. keywords: volcanic field, pyroclastic products, geosite, geopark, campi flegrei. il quaternario italian journal of quaternary sciences 21(1a), 2008 39-46 introduzione da alcuni anni il gruppo di vulcanologia del dipartimento di scienze della terra ha intrapreso un accurato rilevamento geologico dei campi flegrei al fine di produrre un elaborato cartografico finale alla scala 1:10.000. il rilevamento in questione ha interessato l'intera area che, partendo dall'isola di procida, si estende fino alla valle del sebeto dove i prodotti dell'attività esplosiva dei campi flegrei si intercalano con quelli esplosivi ed effusivi provenienti dall'area del somma-vesuvio. proprio nella valle del sebeto, sondaggi per ricerche d'acqua, spinti fino ad una profondità superiore ai 200 metri, hanno messo in evidenza sequenze stratigrafiche che, confrontate con i prodotti in affioramento, hanno fatto comprendere il ruolo strutturale esercitato da questa valle (bellucci et al., 1992). per il rilevamento si è resa necessaria l'adozione di basi topografiche differenti in considerazione del fatto che in alcune aree l'utilizzo di una topografia alla scala 1:5.000 risultava insufficiente per illustrare bene le tipologie dei contatti tra le formazioni. infine nelle aree pianeggianti, ovvero densamente urbanizzate, si è fatto ricorso a stratigrafie dedotte da sondaggi per meglio definire le tipologie dei contatti formazionali e le geometrie di alcune formazioni. durante il rilevamento, inoltre, soprattutto all'interno della caldera, sono state osservate con estremo dettaglio alcune singolarità litologiche e vulcanologiche che ben si armonizzano con il concetto di geosito (wimbledon, 1996; brancucci e burlando, 2001; panizza e piacente, 2002). l'insieme dei geositi rilevati potrebbe andare a costituire il primo parco europeo vulcanologico: il geoparco europeo dei campi flegrei. i campi flegrei sono già sede di un parco naturalistico, il parco regionale dei campi flegrei, istituito alla fine degli anni '90 dalla regione campania e che racchiude un' area vulcanica attiva tra le più affascinanti del mondo. la valle del sebeto e la città di napoli i sondaggi realizzati nella valle del sebeto hanno attraversato, fino ad una profondità di 200 metri, sequenze stratigrafiche che, a partire dall'alto, sono caratterizzate da terreni alluvionali che si intercalano con le due principali formazioni del tufo giallo napoletano (tgn) e dell'ignimbrite campana (ic). nei sondaggi (fig. 1a,b), a tetto del tgn, si riconoscono principalmente i prodotti del somma vesuvio rappresentati dai depositi da flusso della formazione di ottaviano e di avellino, mentre al di sotto del tgn sono state carotate propaggini laviche del somma (bellucci, 1994; 1998; alberico et al., 2005). in questa zona l'aspetto più interessante che emerge dall'analisi dei sondaggi è rappresentato dalla presenza, a varie altezze stratigrafiche, di orizzonti torbosi che testimoniano il 40 l. lirer et al. fig. 1 ubicazione dei sondaggi di cui sono state studiate le stratigrafie e distribuzione delle facies del tgn. 1: sondaggi in cui è stata rinvenuta la facies non litoide del tgn; 2: sondaggi in cui è stata rinvenuta la facies litoide del tgn; 3: sondaggi in cui sono state rinvenute sia la facies litoide del tgn che quella non litoide; 4: linea di separazione tra la facies litoide e non litoide del tgn rinvenute nei sondaggi (a). sezione geologica da poggioreale a san giovanni a teduccio (traccia in fig. 1a) dedotta dall'analisi delle stratigrafie di sondaggi (b) (da alberico et al., 2005, modificato); affioramento di tgn lungo la coll ina dei camaldoli (c); affioramento di tgn litoide (particolare) (d); interno della cava di piperno di pianura (e); fiamme in un blocco di piperno (f). location of investigated drill-holes and distribution of different facies of neapolitan yellow tuff (nyt): 1: drill-holes were the unwelded nyt was found; 2: drill-holes were the welded nyt; 3: drill-holes were both the unwelded and the welded nyt was found; 4: boundary between the unwelded and the welded nyt found in the drill-holes (a). geological section from poggioreale to san giovanni a teduccio (cross-section line in fig. 1a) inferred from the drill-holes sequences (b) (modified from alberico et al., 2005); nyt outcrop on the slops of camaldoli hill (c); welded nyt outcrop (d); piperno quarry at pianura (e); flammae in a piperno block (f). 41proposta di geositi nel quadro di una nuova cartografia ... dinamismo della linea di costa nei vari stadi dell'evoluzione della valle del sebeto (fasi di impaludamento costiero bellucci, 1994). le aree pianeggianti della città di napoli, oltre che dalla valle del sebeto, sono rappresentate dalla piane costiere di fuorigrotta-bagnoli e dalle piane interne di soccavo e pianura. partendo da queste ultime si sale lungo i versanti della collina dei camaldoli, che rappresenta il punto morfologico più elevato dei campi flegrei con i suoi 540 metri di altezza. il fianco orientale della collina è ampiamente solcato da valloni le cui pareti sono costituite dal tgn (fig. 1c,d) che, con i suoi circa 150 metri di spessore, forma l'ossatura della città di napoli; i recapiti finali di tali valloni sono nella valle del sebeto. come è ben noto, il tgn è un materiale che, grazie alle sue caratteristiche tecniche che lo rendono leggero e ottimo isolante sia acustico che termico, è stato ampiamente usato per il patrimonio costruito fino ai tempi prebellici. la facies litoide di colore giallo fa passaggio lateralmente alle “pozzolane”, che rappresentano la facies incoerente. tale passaggio, che spesso avviene in poche decine di metri, determina risposte meccaniche differenti alle sollecitazioni del costruito e talvolta è causa dei dissesti ampiamente diffusi nel sottosuolo cittadino dove sono disseminate un numero elevatissimo di cavità antropiche (circa 800) le cui volte sono poste talvolta anche a poche decine di metri nel sottosuolo. uno dei principali motivi che spinsero le antiche popolazioni a scavare nel sottosuolo, risiede nella considerazione che queste rocce erano facilmente cavabili e soprattutto mostravano caratteristiche di facile lavorabilità. lo sviluppo urbanistico sempre crescente, inoltre, portò alla necessità di reperire nel sottosuolo materiale da costruzione. la fitta rete caveale sotterranea di napoli è giustificata anche dal fatto che la città, impostata unicamente su terreni vulcanici, mancava di una risorsa naturale, l'acqua, fatta eccezione per quella del fiume sebeto. per ovviare a questo problema venne realizzato prima l'acquedotto claudio, risalente al i sec. d.c. e, successivamente, quello del carmignano (xvii sec.).l'acquedotto claudio, attraverso una fitta rete di cunicoli sotterranei -intervallati da cisternelunga molte decine di chilometri e scavata nella roccia tufacea, portava le acque del serino fino alla piscina mirabilis di bacoli nei campi flegrei. all'interno della città di napoli, il tgn è ricoperto da uno spessore di circa 15 metri di depositi piroclastici incoerenti intercalati a paleosuoli. tali prodotti, di carattere esplosivo, sono conseguenza dell'attività recente (< 15 ka) dei vulcani monogenici presenti nella caldera flegrea. spesso le piroclastiti incoerenti producono, lungo i versanti acclivi, fenomenologie franose da colata rapida che, pur non interessando volumi cospicui di materiale, causano danni considerevoli. scendendo lungo il versante occidentale della collina dei camaldoli, si giunge nella caldera flegrea ed in particolare nella zona di soccavo e pianura dove affiorano i termini stratigrafici più antichi della storia vulcanica flegrea. fra questi risulta di particolare interesse la formazione piperno-breccia per la quale è stata anche avanzata una proposta di geosito (fig. 1e). nel maggio 2007, grazie all'interessamento del comune di napoli, è stato possibile visitare la cava borbonica di piperno di masseria del monte a pianura che, in occasione del “maggio dei monumenti”, è stata finalmente riaperta al pubblico (lirer e petrosino, 2007). il piperno è una roccia ornamentale con cui è rivestito gran parte dell'antico patrimonio costruito urbano. questa roccia assume una tessitura molto particolare caratterizzata dalla iso-orientazione dei frammenti iuvenili, in concentrazioni lenticolari grigio-scure di variabile lunghezza e spessore, dette fiamme (fig. 1f), immerse in una matrice cineritica grigio-chiara. a differenza del tufo giallo napoletano, il piperno è una roccia estremamente litoide e pertanto di non facile estraibilità. i cavatori, infatti, separavano in sotterraneo grossi blocchi di roccia che venivano successivamente lavorati all'aperto. grazie alla consistenza lapidea e alla resistenza all'usura da parte degli agenti atmosferici (calcaterra et al., 2005) questa roccia è stata usata come rivestimento di costruzioni e per la realizzazione di portali dei palazzi del centro storico. il piperno si prestava bene alla riduzione in lastre e a lavorazioni più sofisticate, tra cui quella detta bugnato a punta di diamante. l'inizio della coltivazione del piperno a pianura si fa risalire al 1250, tempo in cui iniziarono a determinarsi le condizioni di uno stabile insediamento urbano (il casale de seta, 1984) legato all'attività estrattiva del piperno terminata nell'ultimo dopoguerra. con l'apertura della cava borbonica ed il suo inserimento nel “maggio dei monumenti” si sono create le condizioni, operando sinergicamente con il comune di napoli, per la futura realizzazione di un geosito piperno, al fine di conservare la memoria storica di questa ineguagliabile roccia. la solfatara fin dall'antichità la solfatara di pozzuoli ha colpito la fantasia degli abitanti della regione ed ha alimentato profondamente il mito di grandiose battaglie combattute tra zeus ed i giganti. si trovano interessanti descrizioni della solfatara nei versi di autori antichi, tra cui strabone, cornelio severo, petronio arbitro, silio italico e plinio il vecchio che definì questo luogo “campagna flegrea”. strabone, geografo greco del i secolo a.c., ne dà la più antica testimonianza scritta giunta fino a noi, nella sua “strabonis geographica”, indicandola con il nome “forum vulcani”, dimora del dio vulcano, ingresso per gli inferi. scrive: “…incombe direttamente sulla città l'agorà di efesto (la piazza del dio del fuoco, cioè la solfatara), pianura circondata da ciglioni infuocati che mandano spesso esalazioni come fornaci e piuttosto puzzolenti. la pianura è piena di polvere preziosa…” (geografia,v, 4, 6). e' stato recentemente accettato ed è in stampa sui rendiconti della sgi un lavoro dal titolo “la solfatara: rilevamento vulcanologico e proposta di istituzione di un geosito nei campi flegrei” (armiero et al., 2007a). dal rilevamento geologico dell'area circostante la solfatara, eseguito alla scala 1:5.000, è emerso che questo vulcano monogenico si è impostato su una precedente e più antica morfologia da ash-ring, i l paleoagnano, i cui prodotti affiorano estesamente lungo la parete interna orientale della solfatara. essi, inoltre, costituiscono per la quasi totalità il bordo esterno della solfatara dove si presentano fortemente alterati da un'intensa ed estesa attività fumarolica (fig. 2a) 42 fig. 2 contatto tra i prodotti dell' eruzione della solfatara e le piroclastiti fumarolizzate del paleoagnano (a); particolare di un blocco litico all'interno della breccia dell'eruzione della solfatara (b); eruzione del monte nuovo: contatto tra i prodotti delle unità 1 e 2 (c); eruzione di averno: prodotti da caduta basali (averno 1) (d); eruzione di averno: alternanza di livelli cineritici con pisoliti e livelli da caduta costituiti da clasti pomicei a spigoli vivi (averno 2) (e); tufo giallo dell'archiaverno (f); duomo lavico di cuma (g); cuma: prodotti della formazione dell'acropoli (h). geological contacts between the products of the solfatara eruption and the piroclastiti fumarolizzate of paleoagnano (a); lithic block in the breccia products of the solfatara eruption (b); monte nuovo eruption: contact between the products of unit 1 and 2 (c); averno eruption: basal fall products (averno 1) (d); averno eruption: alternatine ash layers with accretionary lapilli and pyroclastic fall layers made up by coarse pumice clasts (averno 2) (e); archiaverno yellow tuff (f); cuma lava dome (g); cuma: pyroclastic products of the acropoli formation (h). l. lirer et al. formando i cosiddetti colli leucogei. l'eruzione della solfatara, impostatasi quasi ai margini di questa precedente morfologia, ha sensibilmente trapanato la cupola lavica di monte olibano; infatti i primi termini dell'eruzione sono costituiti da un deposito breccioide (fig. 2b) spesso pochi metri passante verso l'alto a terreni cineritici contenenti pisoliti. in definitiva non esiste alcuna morfologia tipica legata all'eruzione della solfatara, ma quanto costituisce i suoi bordi interni ed esterni appartiene ad altre precedenti morfologie. già dall'epoca romana la solfatara era utilizzata come miniera per l'estrazione di zolfo, caolino, realgar ed orpimento. l'attività estrattiva all'interno della solfatara è perdurata fino al 1861, anno in cui essa fu acquistata dalla famiglia de luca che ne favorì la trasformazione in un laboratorio “a cielo aperto” per la sorveglianza dei campi flegrei. ancora oggi la solfatara rimane uno dei principali centri per il monitoraggio dell'attività vulcanica dei campi flegrei. la sorveglianza geochimica è effettuata tramite monitoraggio continuo e discontinuo con lo scopo di riconoscere variazioni imputabili a modificazioni dei parametri chimico-fisici del sistema profondo, in quanto un aumento dell'attività vulcanica può, verosimilmente, tradursi in variazioni composizionali dei fluidi fumarolici e dei flussi dal suolo di specie gassose in particolare di co2. la solfatara è inoltre sede di strumentazioni per la registrazione di variazioni geodetiche e segnali sismici. monte nuovo averno cuma nell'ambito del parco regionale “campi flegrei”, una delle aree di maggiore interesse per quanto riguarda sia gli aspetti geologici che archeologici è quella costituita dall'allineamento monte di cuma lago di averno monte nuovo. il monte nuovo, ubicato ad ovest dell'abitato di pozzuoli, è testimonianza dell'unica eruzione storica dei campi flegrei, che avvenne dal 29 settembre al 6 ottobre del 1538 e che modificò notevolmente la paleogeografia dell'area: il mare interno di averno divenne l'attuale omonimo lago ed il villaggio termale di tripergole fu completamente sepolto (di vito et al., 1987; rosi e sbrana, 1987; orsi et al., 1996). le buone esposizioni dei prodotti di questa eruzione e i fenomeni bradisismici che hanno interessato l'area fin dal i sec. a.c., testimoniati, intorno al x sec d.c., dai fori di litodomi presenti sulle colonne del pronao del tempio di serapide, fanno di pozzuoli un'oasi di richiamo turistico non solo per i suoi aspetti archeologici e vulcanologici ma anche per le indiscusse bellezze del paesaggio. il nuovo rilevamento geologico, eseguito alla scala 1:5.000, non ha evidenziato sostanziali differenze per quanto concerne le caratteristiche della formazione basale unità 1 (fig. 2c). tale formazione, che costituisce gran parte dell'edificio vulcanico, è rappresentata da un deposito piroclastico massivo, composto da pomici e scorie poco vescicolate sub-arrotondate di dimensioni massime intorno ai 40-50 cm, immerse in una matrice compatta a grana grossolana. per quanto riguarda invece la formazione dell' unità 2, legata ad una fase esclusivamente di carattere stromboliano, è stato osservato che alcuni depositi scoriacei mostrano tessiture che sono più consone a digitazioni di flussi piroclastici. il lago d'averno, ora inserito nel naturale anfiteatro di tufo giallo dell' archiaverno (di girolamo et al., 1984) era, in epoca romana, un “mare interno” dove la flotta romana risiedeva protetta dai venti. il rilevamento geologico ha messo in evidenza la sequenza stratigrafica generale dell'area che risulta costituita, a partire dal basso, da: formazione delle mofete o dell'epitaffio, formazione dell'archiaverno (10,7 ka), formazione di baia (8,8 ka), formazione di fondo riccio, formazione dell'averno (3,7 ka), formazione della torretta (2,8 ka). le prime due formazioni sono rappresentate da prodotti tufacei con una colorazione variabile dal biancastro al giallo e i cui caratteri tessiturali indicano deposizioni da correnti piroclastiche. la formazione di fondo riccio, arealmente ridotta ed impostata sui fianchi del vulcano gauro, é costituita da depositi omogeneamente scoriacei (max 50 cm) legati ad una attività esplosiva stromboliana. la formazione dell'averno si suddivide in due unità: quella inferiore (averno 1) è costituita da orizzonti di pomici a spigoli vivi miste a litici lavici e frammenti di tufo giallo dell'archiaverno (fig. 2d); quella superiore (averno 2) è formata principalmente da livelli cineritici contenenti pisoliti cui si alternano orizzonti pomicei a spigoli vivi; a luoghi sono presenti impronte da impatto prodotte da elementi balistici di tufo giallo (fig. 2e). la formazione della torretta rappresenta una novità assoluta per quest'area in quanto i terreni ad essa attribuiti durante la nuova fase di rilevamento sono stati in passato associati alla formazione dell'averno. la formazione della torretta risulta costituita da un deposito breccioide basale in cui alla frazione pomicea grossolana (max 40 cm) si associano frammenti di tufo giallo dell'archiaverno (max 80 cm) i quali determinano impronte da impatto nel sottostante paleosuolo che ricopre i prodotti della formazione dell'averno. verso l'alto la formazione passa ad un livello, gradato inverso, di pomici a spigoli subarrotondati cui segue un deposito di pomici a spigoli vivi (max 40 cm) con rari frammenti litici. all'interno di quest'area, durante l'epoca romana, venne costruito il viadotto di cocceio, una galleria lunga circa un chilometro scavata interamente nel tufo giallo dell'archiaverno (fig. 2f), la quale collegava il mare averno con cuma. nella volta del viadotto cocceio1 furono realizzate sei aperture, diversificate per orientazione, affinché lungo la galleria si verificassero sempre condizioni di visibilità poiché non vi erano altre aperture laterali. la città di cuma fu fondata nel 730 a.c. da colonizzatori dell'eubea che la chiamarono kume' in ricordo di un'antica città dell'asia minore. sulla rocca di cuma si ritrovano, stratificate, le testimonianze di insediamenti di epoche via via più recenti. su frammenti di mura del v sec. a.c. giacciono, infatti, i resti di epoca romana del famoso antro della sibilla, del tempio di apollo e di un tempio attribuito a giove, in seguito adattato a basilica bizantina. 43proposta di geositi nel quadro di una nuova cartografia ... 1il viadotto prese il nome dell'architetto che lo realizzò il promontorio di cuma rappresenta un relitto dell'attività vulcanica più antica dei campi flegrei. per il rilevamento di quest'area è stata utilizzata una base topografica di dettaglio (scala 1:4.000) al fine di evidenziare meglio i contatti tra le formazioni lungo pareti quasi verticali. i terreni rilevati sono riconducibili alle seguenti formazioni che, a partire dal basso, sono: la formazione del duomo lavico di cuma (37 ka; cassignol e gillot, 1983) costituita da una lava trachitica, di colore grigio ed intensamente fratturata, che verso l'alto assume un aspetto scoriaceo (fig. 2g); la formazione del monte di cuma, costituita da un'alternanza di livelli scoriacei a spigoli vivi con livelli cineritico-sabbiosi; nella parte alta le dimensioni delle scorie aumentano e si presentano deformate, allungate ed immerse in una matrice sabbiosa compatta; nella zona settentrionale questa formazione mostra uno spessore di circa 40 m. a tetto di questa formazione a luoghi si rinviene un paleosuolo; la formazione della breccia di cuma, rappresentata da un deposito piroclastico costituito da pomici decimetriche che verso l'alto passa a livelli lentiformi di spatter saldati cui segue un livello breccioide di natura eterogenea; la formazione dell'acropoli (fig. 2h), la cui parte basale è formata la livelli cineritici contenenti clasti pomicei subarrotondati e pisoliti. verso l'alto si passa ad un deposito piroclastico costituito da pomici centimetriche immerse in una matrice cineritico-sabbiosa in cui si rinvengono anche clasti scoriacei e frammenti di ossidiana. il versante orientale del monte di cuma è costiuito dalla formazione del tufo giallo napoletano (15 ka; deino et al., 2004) la quale, alla scala dell'affioramento, presenta aspetti tessiturali caratteristici come laminazioni, dune ed antidune ad alta lunghezza d'onda; il grado di litificazione è variabile ed all'ingresso della crypta romana il deposito si presenta semicoerente. la formazione del tgn, ampiamente diffusa sui bordi della caldera flegrea, si è messa in posto nell'area di cuma quando il promontorio di cuma e quello di monte di procida costituivano delle morfologie continue ovvero rappresentavano paleoisole contro cui impattò il tgn. la susseguente azione del mare deve aver ampiamente ridisegnato la paleomorfologia di quest'area. il geoparco europeo dei campi flegrei. un geoparco europeo è un territorio che deve comprendere un certo numero di siti geologici di particolare importanza in termini di qualità scientifica, rarità, richiamo estetico o valore educativo. esso, inoltre, può contenere siti di interesse archeologico, ecologico, storico o culturale. alla luce di quanto brevemente esposto gli autori ritengono che i quattro geositi descritti, considerato il loro singolare valore non soltanto geologico ma anche storico-culturale, soddisfino tutti i requisiti necessari affinché essi possano, all'interno del parco regionale campi flegrei, costituire il geoparco europeo dei campi flegrei. gli autori propongono quindi, nell'ambito del parco regionale, l'istituzione di un percorso che possa collegare i singoli geositi attraverso la viabilità attuale e, dove possibile, attraverso gallerie ed arterie romane, come ad esempio la via sacra, utilizzate in passato quasi esclusivamente per scopi militari. per ogni geosito sono stati ipotizzati alcuni itinerari lungo i quali sono previsti numerosi stop (armiero et al., 2007b). ogni itinerario viene interamente illustrato da pannelli e poster posizionati all'inizio del sentiero, mentre presso gli stop più significativi verranno installati pannelli divulgativi che li illustreranno in maggiore dettaglio. riferimenti bibliografici armiero v., lirer l., petrosino p. (2007a) la solfatara: rilevamento vulcanologico e proposta di istituzione di un geosito nei campi flegrei. rend. soc. geol. it., in stampa armiero v., lirer l., petrosino p., scamardella g., scamardella m. (2007b) da monte nuovo a cuma: un itinerario nei campi flegrei tra vulcanologia e archeologia. atti del 3 convegno internazionale di geologia & turismo, 1-3 marzo 2007, bologna, in stampa alberico i., petrosino p., zeni g., d'andrea f., lirer l. (2005) geocity: a drill-hole database as a tool to assess geological hazard in napoli urban area. environmental geology, 47, pp. 751-762. bellucci f., corniello a., de riso r., russo d. (1992) idrogeologia della piana a n-e di napoli. mem. soc. geol. it., 45, pp. 339-349. bellucci f. (1994) nuove conoscenze stratigrafiche sui depositi vulcanici del sottosuolo del settore meridionale della piana campana. boll. soc. geol. it., 113, pp. 395-420. bellucci f. (1998) nuove conoscenze stratigrafiche sui depositi effusivi ed esplosivi nel sottosuolo dell'area del somma-vesuvio. boll. soc. geol. it., 117, pp. 385-405. brancucci g., burlando m. (2001) la salvaguardia del patrimonio geologico. scelta strategica per il territorio. l'esperienza della liguria. franco angeli editore, pp. 1-96. calcaterra d., langella a., de' gennaro r., de' gennaro m., cappelletti p. (2005) piperno from campi flegrei: a relevant stone in the historical and monumental heritage of naples (italy). journ. cult. her., 47, pp. 341-352. cassignol c., gillot p.y. (1982) range and effectiveness of unspiked potassium-argon dating: experimental groundwork and application. numerical dating in stratigraphy edited by g.s. odin. de seta c. (1984) i casali di napoli napoli deino a.l., orsi g., de vita s., piochi m. (2004) the age of the neapolitan yellow tuff caldera-forming eruption (campi flegrei caldera italy) assessed by 40ar/39ar dating method. j. volcanol. geotherm. res., 133 (1-4), pp. 157-170. di girolamo p., ghiara m.r., lirer l., munno r., rolandi g., stanzione d. (1984) vulcanologia e petrologia dei campi flegrei. boll. soc. geol. it., 103, pp. 349-413. di vito m., lirer l., mastrolorenzo g., rolandi g. (1987) the 1538 monte nuovo eruption (campi flegrei, italy) bull. volcanol., 49, pp. 608-615. 44 l. lirer et al. lirer l., petrosino p. (2007) cava di piperno località masseria del monte pianura. guida a: “i misteri di napoli” maggio dei monumenti 2007 orsi g., de vita s., di vito m. (1996) the restless, resurgent campi flegrei nested caldera (italy): constraints on its evolution and configuration. j. volcanol. geotherm. res., 74, pp. 179-214. panizza m., piacente s. (2002) geositi nel paesaggio italiano: ricerca, valutazione valorizzazione. un progetto di ricerca per una nuova cultura geologica. geologia dell'ambiente, 2/2002, pp. 3-4. rosi m., sbrana a. (1987) phlegrean fields, quaderni della ricerca scientifica del c.n.r. 114. progetto finalizzato geodinamica. strabone (i sec. a.c.) geografia, v, 4, 6. wimbledon w.a.p. (1996) geosites a new conservation initiative. episodes, 19, pp. 87-88. ms. ricevuto il 2 aprile 2008 testo definitivo ricevuto il 17 aprile 2008 ms. received: april 2, 2008 final text received: april 17, 2008 45proposta di geositi nel quadro di una nuova cartografia ... impaginato cocco lliinneeaammeennttii mmoorrffooddiinnaammiiccii ee sseeddiimmeennttaarrii ddeell lliittoorraallee ddeeii ccaammppii fflleeggrreeii ((ccaammppaanniiaa,, iittaalliiaa mmeerriiddiioonnaallee)) eennnniioo ccooccccoo11,, yyoonnee iiaaccoonnoo22,, ssaabbaattoo iiuulliiaannoo22 && mmaarriiaa rroossaarriiaa lliissttaa22 1dipartimento di scienze della terra, università “federico ii”, napoli. e-mail: encocco@unina.it 2c/o dipartimento di scienze della terra, università “federico ii”, napoli riassunto l’area in esame può essere suddivisa in tre settori a caratteri nettamente differenziati, il litorale di cuma, che ne segna il limite occidentale, il golfo di pozzuoli, che ne costituisce la fascia orientale più complessa ed articolata ed il litorale di miliscola che ne rappresenta il raccordo centrale. il litorale di cuma. esteso per oltre 6 km con orientamento n-s, questo settore costituisce la porzione terminale della piana costiera del f. volturno, la cui foce è situata circa 20 km più a nw. le spiagge basse e sabbiose sono limitate verso l’interno da cordoni dunari in parte allo stato naturale ed in parte fortemente antropizzati. l’evoluzione recente (periodo 1980-1998) è marcata da un arretramento generalizzato nel periodo 1980-1987 seguito da una tendenza all’avanzamento nel successivo periodo 1987-1998, con valori decrescenti procedendo da n verso s. il litorale di miliscola. si estende con orientamento w-e per circa 2 km tra i promontori di monte di procida e di capo miseno ed è limitato verso l’interno da un lago costiero (lago di miseno). in conseguenza ad una forte crisi erosiva che aveva colpito l’area alla metà degli anni ’70 sono state costruite tra il 1980 e il 1988 otto piattaforme-isole che hanno indotto un'accentuata ricostituzione della spiaggia a tergo delle opere; nella parte orientale del settore (verso capo miseno), dove tali opere sono assenti, si instaura una tendenza di tipo erosionale. il golfo di pozzuoli. esteso per oltre 9 km, configura due ampie falcature semicircolari ad andamento e-w, costituite da coste alte e rocciose alternate a coste basse e sabbiose di limitata ampiezza. profonde sono le modificazioni naturali ed antropiche rilevabili in questo settore: tra le prime si ricordano i fenomeni bradisismici che hanno interessato l'area fin dall'antichità portando alla sommersione di notevoli porzioni di territorio litoraneo, tra le seconde una urbanizzazione talmente spinta da stravolgere completamente l’assetto geoambientale naturale della fascia costiera. abstract morphodynamical and sedimentary features of the coast of the phlegrean fields (campania, southern italy). the phlegrean fields are one of the most famous volcanic areas in the world. during the last 50,000 years this area has been formed by the activity of many eruptive centres and today it has the typical morphology of a volcanic field. at present the phlegrean fields are active, even if the last event was recorded a long time ago: the monte nuovo eruption in 1538. the endogenous activity is currently recorded by the frequent inversions of the vertical crustal movements (bradyseism), by the sismicity connected to the bradyseismic events and by the intense thermal activity. from the roman age up to this time the features of the bradyseismic events have not been defined yet because of the type and complexity of the phenomena; recent research shows that the greatest submersion (17÷18 m) was verified during the early middle ages. after the resurgence phase the ground has risen only 6÷7 m: the presence of the submerged roman ruins shows the extent of the sinking.the coastal area could be divided into three clearly diversified sectors: the shore of cuma constituting the western boundary; the gulf of pozzuoli representing the eastern zone, more complex and articulate; the shore of miliscola, the central connection between the two preceeding sectors. the shore of cuma.this sector, extending for about 6 km with n-s orientation between licola mare and monte di procida promontory, constitutes the terminal part of the coastal plain of the volturno river, which flows approximately 20 km to the nw. the low and sandy beaches are limited inland from some foredune ridges, partly natural and partly urbanized. in the northern sector, behind the foredune ridges, there is a wide swampy area reclaimed during the last century ("mazzoni area and licola lake") and in the southern sector there is the fusaro coastal lake. in the central part the promontory of cuma interrupts the outline of the coast; this promontory was the centre of the acropolis during the greek-roman age, but today the acropolis has almost entirely disappeared. within the depth of 5 m the submarine beach shows one or two bar-trough systems: the inner one is crescentic and frequently connected to the rhythmic topography of the shoreline, while the outer one is linear and situated at a distance of about 100 m from the coast. a gentle slope characterizes the submarine beach beyond the bar-trough zone. the evolution of the shoreline presents a general erosional tendency during the years 1980-1987, whereas a tendency to the progradation is evident during the years 1987-1998. the prevailing wind sector is delimited by the 180°-330°n azimuth; most storms are come in from the 270°-300°n sector. the shore of miliscola.the shore of miliscola is situated between the monte di procida and capo miseno promontories and has an extension of approximately 2 km; it is limited inland from the miseno coastal lake. in the western tract we can find various defence works, while in the eastern tract a wide beach is evident. the submarine beach is characterized by a small bar-trough system within the 3 m depth and within a distance of less than 75 m from the coast. eight circular breakwaters have been built from 1980 to 1988 because of strong erosion during the middle '70ies; in these years these defence works have brought an evident beach restoration. after which, until 1996, the shoreline position behind the breakwaters has remained substantially unchanged, while in the eastern part of the sector (toward capo miseno) an erosional tendency was observed with a value of 0.5 m/y. the gulf of pozzuoli.this sector, extending for over 9 km and forming two large semi-circular zones with an w-e orientation, shows high and rocky coasts alternated with small, low sandy beaches. the prevailing wind sector is delimited by the 120°n and the 200°n azimuth; the significant waves come by the 120°-130°n and 180°n azimuth; the maximum fetch and the greatest energetic potential concerns the 180°n azimuth. in this area the modifications are very evident, natural as well as and anthropic. among the natural ones there are the bradyseismic events, that have caused the submersion of entire coastal tracts (for instance: the structures of the portus iulius, the harbour of the ancient roman imperial navy) and the monte nuovo eruption in 1538, that changed the coastal configuration in the western zone of the gulf. among the anthropic ones there is a strong urbanization (“ilva” iron and steel industry, various defence work, artificial coastal platforms) that has completely destroyed the natural environment of the area. parole chiave: processi morfodinamici, distribuzione dei sedimenti, variazioni della linea di riva, interventi antropici, bradisismo. keywords: nearshore morphodynamics, sediment distribution , shorelines changes, human activities, bradyseism. il quaternario italian journal of quaternary sciences 1155(2), 2002, 209-220 210 e. cocco et alii 11.. pprreemmeessssaa in questa nota vengono riportati i risultati delle indagini condotte lungo il litorale dei campi flegrei (campania) nel periodo 1996-98 nell’ambito del prog. strategico cnr “ambiente e territorio”, sottoprog. “sistemi naturali ed antropici”. in maggior dettaglio sono stati eseguiti 25 transetti batimetrici ortogonali alla costa entro la profondità di 15 m, prelevati ed analizzati 68 campioni di sedimenti di fondo subsuperficiali e determinate le principali caratteristiche dinamico-evolutive (parametri ondosi e variazioni recenti della linea di riva). e. cocco ha coordinato le ricerche, occupandosi in particolare degli aspetti relativi ai fenomeni bradisismici e della stesura finale del testo; y. iacono e s. iuliano hanno eseguito le varie campagne di rilevamento curando rispettivamente gli aspetti sedimentologici e quelli morfoevolutivi; m.r. lista si è interessata della cartografia storica e delle modificazioni antropiche. i campi flegrei costituiscono un'area vulcanica tra le più famose nel mondo. formatasi nel corso degli ultimi 50.000 anni (rosi & sbrana, 1987) attraverso numerosi centri eruttivi che le hanno conferito la caratteristica morfologia di un campo vulcanico, l'area è ritenuta attiva sebbene sia stata registrata una sola manifestazione effusiva in epoca storica: l'eruzione del monte nuovo nel 1538. l’attività endogena non sopita è segnalata dalle frequenti inversioni del moto del suolo (bradisismo), dalla sismicità che accompagna le crisi bradisismiche e dalle intense manifestazioni termali. per quanto riguarda l’evoluzione del fenomeno bradisismico dall’epoca romana ad oggi, gli studi più recenti (cinque et al., 1991; di vito & luongo, 1993; russo et al., 1998; milia et al., 2000) indicano che la maggiore sommersione si è verificata in epoca alto medioevale superando i 17÷18 m dei quali solo 6÷7 sono stati recuperati in seguito alle successive fasi ascensionali (la testimonianza di uno sprofondamento così vistoso è data dalla presenza di ruderi romani a varie profondità nell’area di baia e miseno). 22.. ccaarraatttteerrii mmoorrffooddiinnaammiiccii ee sseeddiimmeennttaarrii l’area in esame può essere suddivisa in tre settori a caratteri nettamente differenziati, il litorale di cuma, che ne segna il limite occidentale, il golfo di pozzuoli, che ne costituisce la fascia orientale più complessa ed articolata ed il litorale di miliscola che ne rappresenta il raccordo centrale (fig. 1). 22..11 iill lliittoorraallee ddii ccuummaa esteso per oltre 6 km con orientamento n-s tra licola mare ed i l promontorio di monte di procida, questo settore costituisce la porzione terminale della piana costiera del f. volturno, la cui foce è situata circa 20 km più a nw; le spiagge basse e sabbiose sono limitate verso l’interno da cordoni dunari in parte allo stato naturale ed in parte fortemente antropizzati (fig. 2), cui fanno seguito, a n, una vasta area acquitrinosa bonificata nel secolo scorso (“mazzoni, lago di licola”) ed a s il lago costiero del fusaro. il profilo della costa è interrotto nella parte centrale dal promontorio di monte di cuma, sede dell’antica acropoli di epoca romana (nulla, o quasi, rimane della città greca, la più antica d’italia vallet, 1990). l’assetto morfologico dei fondali antistanti il litorale di cuma è stato delineato mediante l’elaborazione di 6 profili batimetrici eseguiti ad interasse medio di 400 m, fino alla profondità di 10 m. la spiaggia sottomarina presenta, entro la profondità di 4 m, uno o due sistemi di barra-truogolo con la cresta barra ad una profondità compresa tra 1,3 e 2,6 m (figg. 3a e 3b); la barra interna risulta festonata e collegata alle ondulazioni ritmiche della linea di riva (sand waves cocco, 1976), mentre quella esterna è più rettilinea, ad una distanza di un centinaio di metri dalla battigia. le pendenze dei fondali sono inferiori all’1 % fino alla profondità di circa 1 m, per poi passare, in corrispondenza della zona del secondo ordine di barre, a valori compresi tra 1 e 2,5 %; oltre l’isobata dei 3 m le pendenze si addolciscono e, fino ai -10 m, sono comprese nell’intervallo 0,5÷1 % (fig. 4). si ricorda che nell'area immediatamente a s del promontorio di monte di cuma era posizionato secondo l’ipotesi di paget (1968) l'antico porto romano oggi obliterato da colluvioni e da materiale vulcanico; recenti indagini (vecchi et al., 2000) tendono ad ubicare il porto nella parte settentrionale del promontorio, in corrispondenza del lago di licola, oggi bonificato. l'analisi delle variazioni recenti della linea di riva (fig. 5) condotta attraverso il confronto aerofotografico (levate del 1980, 1987 e 1998) evidenzia tre zone a fig. 1 ubicazione dell’area in studio. location of the study area. 211lineamenti morfodinamici e sedimentari ... fig. 4 litorale di cuma. carta delle isobate del tratto compreso tra foce fusaro e torre gaveta. the shore of cuma. bathymetric map of the sector between foce fusaro and torre gaveta localities. fig. 2 litorale di cuma. ad un’ampia spiaggia fa seguito un cordone dunare più o meno antropizzato. sullo sfondo il promontorio di monte di cuma. the shore of cuma. the backshore is followed inland by a foredune ridge more or less affected by human activities. in the background the monte di cuma promontory. fig. 3 litorale di cuma. profili batimetrici della spiaggia sommersa (ecografo elac-laz 721 munito di trasduttore a 200 khz; le linee orizzontali indicano gli intervalli di profondità ogni 4 m): aprofilo ad un solo sistema di barre (p24, fig. 4); bprofilo a doppio ordine di barre (p22, fig. 4). the shore of cuma: bathigrams of submarine beach. an echographer model elac-laz 721 with a frequency of 200 khz transducer was used, the horizontal lines indicate the 4 m depth intervals; asingle bar and trough profile (p24, fig. 4); bdouble bar and trough profile (p22, fig. 4). 212 diversa evoluzione -rispettivamente comprese tra i punti di riferimento 1…7, 8…20 e 21…33caratterizzate da una tendenza generalizzata all’arretramento nel periodo 1980-1987 e da una tendenza generalizzata all’avanzamento nel successivo periodo 1987-1998, sempre con valori decrescenti procedendo da n verso s. in particolare per il primo periodo i valori di arretramento medio risultano rispettivamente pari a 4,6 m, 1,8 m e 0,5 m per anno nelle tre zone citate, per il secondo periodo i valori di avanzamento medio risultano pari a 2,5 m, 1,4 m e 0,4 m per anno, sempre per le medesime aree. l'arretramento evidenziato nel 1987 può essere attribuito alla mareggiata eccezionale che ha colpito la costa del tirreno meridionale nel mese di gennaio. per quanto riguarda i l regime meteomarino, il settore di traversia risulta compreso tra 180°n e 330°n, i l fetch massimo è pari a 401 miglia nautiche (direttrice 240°n), le ondazioni di maggiore frequenza ed intensità (1350 eventi su un totale di 1820) provengono dal subsettore 270°300°n (tab. 1). l’altezza d’onda media di modellamento è compresa tra 0,7 e 2,16 m, l’altezza massima per un periodo di ritorno trentennale è pari a 7,18 m (direttr ice 250°n). 22..22 ii ll ll ii ttoorraallee ddii mmiilliissccoollaa si estende per circa 2 km con orientamento w-e tra i promontori di monte di procida e di capo miseno (fig. 6) ed è limitato verso l’interno da un lago costiero (lago di misenomaremorto). il tratto occidentale è caratterizzato da una serie di opere marittime a varia tipologia (8 piattaforme-isole, 3 scogliere aderenti, 1 pennello ed 1 foce armata) a difesa di una spiaggia di ampiezza ridotta, mentre quello orientale configura una profonda falcatura con una spiaggia emersa ampia fino a 70 m. i caratteri morfologici della spiaggia sommersa sono stati delineati mediante l’esecuzione di 9 profili batimetrici ad interasse di circa 200 m fino alla profondità di 10 m (figg. 7 e 8): nella parte occidentale la morfologia è fortemente condizionata dalla presenza delle otto piattaforme-isole, che conferiscono ai fondali un andamento irregolare con pendenze variabili tra 1 e 4 %; nella parte orientale, dove le piattaforme mancano, i fondali risultano caratterizzati da un sistema barra truogolo poco sviluppato entro la profondità di 3 m ad una distanza dalla battigia non superiore a 75 m. oltre la profondità di 3 m e fino a -10 m la morfologia si regolarizza in tutto il settore, con pendenze come. cocco et alii tab. 1 litorale di cuma. principali caratteristiche del moto ondoso. modello previsionale smb (c.e.r.c., 1984), dati di vento rilevati alla stazione di ponza nel periodo 1951-1981. the shore of cuma. main feature of wave climate (smb method, wind data recorded at the ponza st. during fig. 5 litorale di cuma. diagramma delle variazioni della linea di riva nel periodo 1980-1998. i punti di riferimento presentano un intervallo di circa 300 m, procedendo da n verso s; i punti 9...15 marcano la spiaggia antistante il promontorio di monte di cuma. the shore of cuma. shoreline changes during the 1980-1998 period. reference points 9…15 mark the shore in front of the monte di cuma promontory. 213 prese tra 0,5÷1 % (lato piattaforme-isole) e 1,5÷2 % (lato capo miseno). la spiaggia di miliscola costituiva, fin dall’epoca romana, il limite meridionale dei due bacini portuali della flotta augustea: il bacino interno (maremorto) fungeva da cantiere navale, quello esterno -la baia di misenocostituiva il porto vero e proprio. il nome della spiaggia deriva da “militium schola”, cioè il campo di esercitazione e di addestramento delle reclute, ricordata come “schola armaturarum” in una iscrizione del iv sec. d.c. ivi rinvenuta. da rilevare che, secondo cinque et al. 1991, anche quest’area, oltre a quelle classiche di baia e pozzuoli, è stata soggetta a movimenti bradisismici, come testimoniato dalla successione stratigrafica dei terreni che seppelliscono i resti del complesso termale di misenum della prima metà del ii sec. d. c., posti all’estremità sud orientale della spiaggia di miliscola. l’area misenate avrebbe registrato, tra la fine del vii sec. ed il ix-x sec. d. c., un abbassamento di circa 11÷12 m. l’equilibrio dinamico della spiaggia ha incominciato ad alterarsi allorquando negli anni ‘50/60 si è proceduto al prolungamento del canale di comunicazione tra il bacino di maremorto (lago miseno) ed il mare: tale canale, fungendo da pennello, ha provocato un repentino arretramento (13 m nel periodo 1965-1974) dell’arenile di sottoflutto, posto ad est. sul litorale in erosione si è abbattuta nel 1976 una violenta mareggiata talché si è proceduto alla realizzazione di un progetto organico di difesa attraverso la messa in opera di barriere radenti e di otto piattaforme-isole tra i l 1980 ed il 1988 (figg. 6 e 9). il progetto originale, mai ultimato, prevedeva la realizzazione di una nona piattaforma-isola e di due pennelli collegati alla piattaforme più esterne, la prima e la nona. il confronto cartografico (fig. 9) ha messo in evidenza, per il periodo19781986, un'accentuata ricostituzione della spiaggia nell ’area “protetta” dalle opere di difesa; con valori medi di avanzamento pari a 3 m per anno; ad est delle opere (zona di sottoflutto) la lineamenti morfodinamici e sedimentari ... fig. 6 panoramica del litorale di miliscola. al centro della foto si può osservare la foce armata del canale di comunicazione con il lago miseno (a sinistra); sullo sfondo capo miseno. the shore of miliscola towards capo miseno. note the various defence works (jetties, seawalls and detached breakwaters) in the western part of the shore. fig. 7 litorale di mil iscola. profi l i batimetrici della spiaggia sommersa (v. fig. 3): aprofilo senza barre (p12, fig. 8); bprofilo ad un solo ordine di barre (p16, fig. 8). the shore of m i l i s c o l a . bathigrams of submarine beach (see fig. 3): ano bar profile (p12, fig. 8); bsingle bar and trough profile (p16, fig. 8). 214 riva configura una repentina falcatura di erosione quindi, procedendo verso capo miseno (grotta dragonara), si osserva una debole tendenza alla progradazione. nel periodo 1986-1996 la posizione della linea di riva a tergo delle piattaforme-isole è rimasta sostanzialmente immutata, eccezion fatta per l'area a tergo delle ultime due piattaforme -posizionate proprio tra il 1986 ed il 1988dove si verifica un notevole ripascimento (5 m/a). nella parte orientale del settore (verso capo miseno), dove tali opere sono assenti, si instaura una tendenza di tipo erosionale con valori di arretramento nell’ordine di 0,5 m/a. 22..33 iill ggoollffoo ddii ppoozzzzuuoollii esteso per oltre 9 km, configura due ampie falcature semicircolari ad andamento e-w, separate dalla falesia di rione terra (centro storico di pozzuoli); la costa si presenta alta e rocciosa alternata a spiagge basse e sabbiose limitate talvolta verso l’interno da laghi costieri (lucrino). nell ’area occidentale del golfo -litorale di lucrino, fig. 10sono stati eseguiti 10 profili batimetrici (figg. 11 e 12) e prelevati 68 campioni di sedimenti di fondo mobile entro la profondità di 10 m. i fondali si presentano con pendenze minori del 2% fino ai 5 m di profondità e con pendenze comprese tra 2 e 6 % a profondità maggiori (fig. 12). seguendo la metodologia di dias & neal (1990) i sedimenti sono risultati per il 77% polimodali (fino ad un massimo di 6 mode), la maggiore frequenza è rappresentata dalla trimodalità (26%); sottoriva sono presenti sedimenti ad 1÷2 mode, procedendo verso il largo prevale la polimodalità (fig. 13). l’applicazione di analisi statistiche (iacono et al., 1998) ha permesso da un lato (cluster analysis) di individuare tre gruppi omogenei di sedimenti caratterizzati dal raggruppamento di campioni a simile contenuto di silt, sabbia e ghiaia e dall’altro (biplot analysis) di legare l’esistenza dei tre gruppi con la loro composizione granulometrica prevalente permettendo di individuare le relazioni campioni-granulometria in modo più specifico. in particolare queste analisi hanno evidenziato che i sedimenti della porzione occidentale del golfo di pozzuoli sono caratterizzati da un corpo principale prevalentemente sabbioso che talvolta si arricchisce in termini siltosi -rinvenibili in aree a bassa energia riparate dal moto ondoso o a profondità superiori a 10 me talvolta si arricchisce in termini ghiaiosi rinvenibili in ambiente ad alta energia (sottoriva). quando questi ultimi sedimenti si rinvengono a profondità comprese tra 5 e. cocco et alii fig. 8 litorale di miliscola: carta delle isobate. the shore of miliscola: bathymetric map. fig. 9 litorale di miliscola. variazioni della linea di riva nel periodo 1978-1996 (dalla cartografia del comune di bacoli in scala 1:10.000). the shore of miliscola. shoreline changes during the 1978-1996 period. e 15 m, come nel caso in esame, testimoniano spiagge relitte. la mobilitazione dei sedimenti avviene prevalentemente per long shore current da e verso w, come è confermato dalla configurazione asimmetrica della linea di riva nei pressi dei numerosi pennelli presenti nell’area di lucrino. si ricorda che studi precedenti (cocco et al., 1988a, 1988b) avevano evidenziato la presenza di antiche spiagge sommerse di epoca romana, marcate nell’area di pozzuoli dalle strutture archeologiche del portus julius (il porto della flotta imperiale romana) alla profondità di circa 3 m (v. figg. 14 e 15) e che i sedimenti presenti nella spiaggia sottomarina e nei fon215lineamenti morfodinamici e sedimentari ... fig. 10 panoramica del litorale di lucrino limitato verso l’interno dal lago di lucrino. sullo sfondo, a destra, il vulcano di monte nuovo. the shore of lucrino, limited inland by lucrino lake. in the background, on the right, we can observe the monte nuovo volcano. fig. 11 litorale di lucrino. profili batimetrici della spiaggia sommersa (v. fig. 3): aprofilo a doppio ordine di barre (p2, fig. 12); bprofilo senza barre (p4, fig. 12); cprofilo con i ruderi sommersi del “portus julius” (p8, fig.12) che indicano l’antica linea di costa di epoca romana alla profondità di 4 m (v. fig. 15). the shore of lucrino. bathigrams of submarine beach (see fig. 3): adouble bar and trough profile (p2, fig. 12); bno bar profile (p4, fig. 12); cprofile with the ruins of “portus julius” (p8, fig.12) that show the ancient coastline during the roman age at the –4 m depth (see fig. 15). dali entro la profondità di 30 m erano costituiti esclusivamente da sabbie da molto fini a molto grossolane, con una dispersione delle frazioni più sottili dalle aree centrali del golfo sia verso w che verso e. la presenza di sabbie grossolane a profondità superiori a 10÷12 m era stata correlata proprio ai depositi relitti delle antiche spiagge. dal punto di vista meteomarino, il settore di traversia del golfo di pozzuoli (porzione occidentale, litorale di lucrino) risulta compreso tra 120°n e 200°n (tab. 2), i fetches sono compresi tra 1 e 20 miglia nautiche, fatta eccezione per la direttrice 180°n cui corrisponde l ’estensione di 162 m.n. ed una frequenza molto alta degli eventi (141 su un totale di 704, pari al 20%). l’altezza d’onda media di modellamento è compresa tra 0,66 e 1,38 m, l ’altezza massima per un periodo di ritorno trentennale è pari a 3,78 m (direttrice 170°n). 22..33..11 llee mmooddiiffiiccaazziioonnii nnaattuurraallii la costa flegrea negli ultimi due millenni è stata oggetto di ripetute sommersioni da parte del mare a causa dei moti bradisismici con forti modificazioni della topografia costiera (figg. 14 e 15). grazie allo studio condotto sui fori di litodomi riscontrati sulle colonne del serapeo di pozzuoli (parascandola, 1947) è stato stabilito che l’area flegrea sia iniziata a sprofondare già dal i-ii secolo d.c.; questa fase di moto discendente 216 e. cocco et alii fig. 12 litorale di lucrino. carta delle isobate. the shore of lucrino. bathymetric map. tab. 2 litorale di lucrino. principali caratteristiche del moto ondoso. modello previsionale smb (c.e.r.c., 1984), dati di vento rilevati alla stazione di ponza nel periodo 1951-1981. the shore of lucrino. main featur of wave climate (smb method, wind data recorded at the ponza st. during the 1951-1981 period). fig. 13 distribuzione areale delle mode dei sedimenti della spiaggia sommersa di lucrino. the lucrino submarine beach: spatial distribution of the modes of the sediments. sarebbe continuata fino al x secolo d.c. superando i 1718 m dei quali solo 6-7 sono stati recuperati in seguito alle successive fasi ascensionali (russo et al., 1994). dopo un periodo di stasi, sarebbe seguito, dall’ xi fino al xvi secolo, un innalzamento culminato con l’eruzione del monte nuovo nel 1538 la quale dovette apportare profonde modifiche alla morfologia della costa il cui bordo era costituito verosimilmente dalla falesia de “la starza” (fig. 14). il lucrino a quel tempo non era un lago, mentre il lago d’averno era aperto verso il mare da cui era limitato mediante una imponente diga foranea. a partire dal xvii secolo si è assistito ad un lento abbas217lineamenti morfodinamici e sedimentari ... fig. 14 configurazione della costa flegrea in epoca romana con il portus iulius e la linea di riva (ripa puteolana). (da s.t.r. 1993, modificata). the coastal morphology of the gulf of pozzuoli during the roman age. fig. 15 ruderi sommersi dell’antico porto romano di età augustea (portus iulius) nell’area prospiciente il litorale di lucrino (foto cocco, 1987). submerged ruins of the “portus iulius”, the harbour of the ancient roman imperial navy, in front of the lucrino shore. samento del suolo fino alle crisi bradisismiche del 19701972 e 1982-1984, caratterizzate da rapidi e vistosi sollevamenti fino ad un massimo di 330 cm in corrispondenza della falesia di rione terra, su cui sorge il centro storico di pozzuoli (di vito et al., 1987). proprio la dinamica delle due ultime crisi fa supporre, anche sulla base delle documentazioni storiche, che la sommersione di epoca medioevale sia imputabile ad un rapido sprofondamento piuttosto che ad un lento e secolare abbassamento (di vito & luongo, 1993). queste ultime crisi non hanno comportato variazioni planimetriche delle spiagge poste ai limiti occidentale ed orientale del golfo, come è testimoniato dal confronto delle numerose carte topografiche e levate aeree a disposizione per il periodo 1981-1998 (in particolare il confronto 1981-1986 indica una sorprendente stabilità della linea di riva in special modo nell'area delle stufe di nerone, fig. 16) e come è confermato dai dati dell’osservatorio vesuviano nell’ambito della sorveglianza delle aree vulcaniche napoletane. le misure distanziometriche effettuate nell’area nel periodo 19831995 (osservatorio vesuviano, 1995) hanno mostrato una contrazione delle linee misurate (13 cm nel periodo novembre ’91 – giugno ‘95) coerenti con la fase di deflessione della caldera. un'ulteriore conferma è data dal fatto che l’area interessata dal sollevamento presenta una forma circolare con raggio di circa 6 km con centro nella zona del porto di pozzuoli dove gli spostamenti verticali raggiungono la massima entità di sollevamento (330 cm), mentre vanno via via decrescendo fino ad un minimo di 40÷20 cm procedendo verso w e verso e proprio in corrispondenza rispettivamente con le spiagge di lucrino e di bagnoli-coroglio. 22..33..22 llaa ccaarrttooggrraaffiiaa ssttoorriiccaa le prime carte topografiche dei campi flegrei risalgono al xvi secolo e sono opera di incisori fiamminghi. esse sono sostanzialmente riconducibili a due filoni: il primo, derivato dalle incisioni del pittore g. hoefnagel, rientra nel genere del paesaggio pittorico, con poche indicazioni di siti specifici; il secondo, che risale all’olandese n. van aelst, è costituito da vere e proprie carte topografiche, intese come rappresentazione dettagliata del territorio, benché resa in maniera figurativa. al modello di carte di van aelst si rifecero tutti i cartografi successivi, a cominciare da cartaro nella redazione del suo ager puteolanus del 1584, molto interessante per la rappresentazione che vi si fa di molti edifici antichi, nonché di vie di comunicazioni interne. nella seconda metà del xviii secolo, sotto la spinta di nuovi interessi scientifici, quali la vulcanologia e la geologia, la rappresentazione cartografica cominciò a diventare sempre meno figurativa e più tecnica. risale a questo periodo, precisamente al 1782, la “carte du golfe de pouzzoles avec une partie des champs phlégréens dans la terre de labour”, disegnata da un ingegnere militare del regno borbonico, pietro la vega, e inclusa nel “voyage pittoresque” di saintnon. in questa carta topografica si ritrova una particolare attenzione per le testimonianze archeologiche accompagnata da una grande precisione nella rappresentazione dell’orografia. sempre nella seconda metà del xviii secolo, con l’istituzione dell’officina topografica di g. a. rizzi zannoni, nacque una vera e propria scuola di incisione topografica e cominciò una produzione cartografica sistematica che culminerà con la pubblicazione degli atlanti terrestre e marittimo e di varie carte a grande scala dell’area napoletana. tra queste è da segnalare la carta dell’agro napoletano, alla scala 1:50.000, risalente al 1793 e la “carta topografica ed idrografica dei contorni di napoli” alla scala 1:25.000 risalente al 18181819, mostrante con grandissima ricchezza di dettaglio tutte le particolarità del territorio (valerio, 1983). tale carta costituirà, per oltre mezzo secolo, l’unico riferimento attendibile, non solo dell’area flegrea, ma di tutta l’area napoletana (laureti, 1983), tanto da venire ulteriormente aggiornata, nel 1872, da parte dell’istituto topografico militare italiano, sorto, dopo la proclamazione del regno d’italia, dalla fusione degli uffici topografici dei vari stati della penisola. 22..33..33 llee mmooddiiffiiccaazziioonnii aannttrrooppiicchhee fino al 1880 i campi flegrei erano ancora incontaminati, immersi nel verde e circondati da un mare ancora pescoso e cristallino (giamminelli, 1987). oltre alla pesca, il termalismo, con le annesse attività ricreative ed alberghiere, era una delle fonti primarie dell’economia flegrea, tant’è che fu ideato da lamont young (alisio, 1984) un grandioso progetto che prevedeva l’utilizzazione dell’arenile per la balneazione, la costruzione di grandi alberghi, di palazzi per esposizioni e, ovviamente, di abitazioni disposte in maniera molto elegante e separate, di tanto in tanto, da canali alimentati dal mare. questo progetto non fu mai realizzato, anzi, l’economia puteolana fu parzialmente trasformata, nel 1886, dall ’ istal lazione dello stabil imento metallurgico 218 e. cocco et alii fig. 16 litorale di lucrino. variazioni della linea di riva nel periodo 1981-1986 (dalla cartografia del comune di pozzuoli in scala 1:4.000). the shore of lucrino. shoreline changes during the 1981-1986 period. armstrong che occupò quasi completamente il litorale tra pozzuoli ed arco felice, dando così inizio al progressivo degrado ambientale ed all’alterazione del paesaggio costiero che nei decenni successivi, con il procedere dell’industrializzazione (ad es. ilva di bagnoli), interessarono tutto il golfo. negli ultimi 50 anni si evidenzia la progressiva e totale antropizzazione della fascia costiera: lungo il tratto occidentale del golfo (stufe di nerone porto di pozzuoli) la linea di riva si presenta frazionata in tante curve spezzate, limitate da opere di difesa trasversali; il settore centrale risulta caratterizzato dalla presenza, quasi ininterrotta, di barriere emerse, talché il lungomare di pozzuoli (figg. 17 a e b) e la strada litoranea verso bagnoli risultano separate dal mare a mezzo di una continua scogliera aderente e di ripetute colmate in cemento; la fascia orientale (la pietra coroglio) presenta lunghi pontili ed ampie piattaforme artificiali, legati agli stabilimenti industriali (figg. 17 c e d). 33.. ccoonncclluussiioonnii le ricerche condotte lungo la fascia costiera dei campi flegrei hanno messo in evidenza tre tratti a caratteri ed evoluzione differenziati. 1) il litorale di cuma, con l’assetto tipico di una costa sabbiosa deposita limitata verso l’interno da cordoni dunari più o meno antropizzati, alimentata dal materiale terrigeno proveniente dal f. volturno, attraverso le correnti di lungo costa. il settore risulta molto esposto alle ondazioni provenienti da w-nw. 2) il litorale di miliscola, caratterizzato da una marcata crisi erosiva negli anni ’70 cui si è cercato di porre rimedio attraverso la realizzazione di numerose opere di difesa che hanno stabilizzato solo parzialmente il settore inducendo una tendenza all’arretramento nell’area di sottoflutto. 3) il golfo di pozzuoli, caratterizzato da profonde modifiche naturali fin dall’epoca storica (bradisismo, eruzione di monte nuovo) e da una antropizzazione crescente a partire dalla fine del xix secolo ad oggi (le spiagge naturali oggi sono praticamente assenti). le ultime crisi bradisismiche degli anni ’70 e ‘80 hanno provocato una evidente emersione (oltre 300 cm) della falesia di rione terra su cui sorge il centro storico di pozzuoli, ma non hanno comportato variazioni planimetriche apprezzabili delle spiagge poste ai limiti occidentale (lucrino) ed orientale (bagnoli) del golfo dove i sollevamenti sono stati dell’ordine di pochi decimetri. rriinnggrraazziiaammeennttii si ringrazia l’ing. m. serpico per il contributo relativo alla definizione delle caratteristiche principali del moto ondoso. la stampa del presente articolo è stata supportata da fondi di ricerca individuali. 219lineamenti morfodinamici e sedimentari ... fig. 17 antropizzazione della fascia costiera. a e b: come si presentava il lungomare di via napoli (pozzuoli) negli anni ‘50 e nel 1998. c e d: il litorale di bagnoli agli inizi del ‘900 e nel 1998. human activities along the coast of pozzuoli (during the ‘50 -a and 1998 -b) and bagnoli (in the beginning of 1900 –c and in 1998 –d). 220 ms. ricevuto il 19 febbraio 2002 testo definitivo ricevuto il 24 settembre 2002 ms. received: february 19, 2002 final text received: september 24, 2002 llaavvoorrii cciittaattii alisio g. (1984) “lamount young: utopia e realtà nell’urbanistica napoletana dell’ottocento”. officina edizioni, roma, 194 pp. c.e.r.c. (coastal engineering research center) (1984) – shore protection manual (4th ed.). u.s. army corps of engineers, vol. 1-2. cinque a., russo f. & pagano m. (1991) la successione dei terreni di età post-romana delle terme di miseno (napoli): nuovi dati per la storia e la stratigrafia del bradisisma puteolano. boll. soc. geol. it., 111100, 231-244. cocco e. (1976) forme costiere ritmiche “sand waves” lungo il litorale alto ionico (golfo di taranto). boll. soc. geol. it., 9944, 861-869. cocco e., de magistris m.a. & de pippo t. (1988) distribuzione e dispersione del sedimenti nella piattaforma costiera del golfo di pozzuoli. mem. soc. geol. it., 4411, 983-993. cocco e., de pippo t., efaicchio m.t. & tarallo f. (1988) caratteri morfologici della piattaforma costiera del golfo di pozzuoli. mem. soc. geol. it., 4411, 995-1004. dias alveirinho j. m. & neal, w.j. (1990) modal size classification of sands: an example from the northern portugal, continental shelf. journal of sedimentary petrology, 6600, n. 3, 426-437. di vito m., lirer l., mastrolorenzo g. & rolandi g. (1987) the 1538 monte nuovo eruption (campi flegrei, italy). bull. volcanol., 4499, 608-615. di vito m. & luongo g. (1993) bradyseism and sea level variations in the neapolitan area over the last 12,000 years. atti del convegno: “l’evoluzione dell’ambiente fisico nel periodo storico nell’area circum-mediterranea”. ravello, 5-8 giugno 1993, in stampa su p.a.c.t. iacono y., buccianti a. & cocco e. (1998) the distribution of sediments in the pozzuoli gulf (naples, italy): a multivariate approach. proceedings of iamg ’98 (buccianti a., nardi g. & potenza r., eds) isola d’ischia, naples, 519-525. giamminelli r. (1987) immagine dei campi flegrei fra ottocento e novecento nelle cartoline della collezione michele iaccarino. guida ed., napoli. laureti l. (1983) la rappresentazione cartografica dei campi flegrei e del vesuvio. in “cartografia napoletana dal 1781 al 1889”, a cura di alisio g. e valerio v. prismi, editrice politecnica, napoli, 6166. milia a., torrente m.m. & giordano f. (2000) active deformation and volcanism offshore campi flegrei, italy: new data from high-resolution seismic reflection profiles. marine geology, 117711, 6173. osservatorio vesuviano (1995) la sorveglianza delle aree vulcaniche napoletane. rapporto dicembre 1995, 47 pp. paget r.f. (1968) the ancient port of cumae. the journal of roman studies, 5588, 1-2, 148-169. parascandola a. (1947) i fenomeni bradisismici del serapeo di pozzuoli. guida, napoli, 115 pp. rosi m. & sbrana a. (eds) (1987) phlegrean fields. quad. de "la ricerca scientifica", cnr, roma, 111144, 168 pp. russo f., calderoni g. & lombardo m. (1998) evoluzione geomorfologia della depressione bagnoli-fuorigrotta periferia urbana della città di napoli. boll. soc. geol. it., 111177, 21-38. russo f., donadio c. & galeotti f. (1994) risultati di recenti rilevamenti geomorfologici e geoarcheologici nell’area costiera puteolana. iv conf. scient. sulle attività di ricerca dei dipartimenti geomineralogici, 21-23 aprile 1994, 205-207. s.t.r. (1993) campi flegrei viaggio nel mito. carta in scala 1:15.000. napoli. valerio v. (1983) la carta dei contorni di napoli degli anni 1817-1819 ed il reale officio topografico del regno di napoli. in “cartografia napoletana dal 1781 al 1889”, a cura di alisio g. e valerio v. prismi, editrice politecnica, napoli, 29-40. vallet g. (1990) i greci in campania. in “ i campi flegrei un itinerario archeologico” (a cura di amalfitano p., camodeca g., medri m.). marsilio editori, napoli, 7-10. vecchi l., morhange c., blanc p.-f., goiran j.-p., buï thi mai, bourcier m., carbonel p., demant a., gasse f., girard m. & verrecchia e. (2000) la mobilité des milieux littoraux de cumes, champs phlégréens, campanie, ital ie du sud. méditerranée n° 1-2, 71-82. imp.orombelli& osservazioni sul significato dei termini lgm (umg), tardoglaciale e postglaciale in ambito globale, italiano ed alpino giuseppe orombelli 1 , cesare ravazzi 2 & maria bianca cita3 1dipartimento di scienze dell’ambiente e del territorio, università di milano bicocca, giuseppe.orombelli@unimib.it 2cnr – istituto per la dinamica dei processi ambientali, sezione di milano. cesare.ravazzi@idpa.cnr.it 3dipartimento di scienze della terra, università di milano, maria.cita@unimi.it. riassunto: g. orombelli, c. ravazzi, m.b. cita, osservazioni sul significato dei termini lgm (umg), tardoglaciale e postglaciale in ambito globale, italiano ed alpino. (it issn 0394-3356, 2005). il presente lavoro intende esaminare il significato e l’impiego di alcuni termini dal forte segnale climatico in uso nella stratigrafia del quaternario continentale: last glacial maximum (ultimo massimo glaciale); lateglacial (tardoglaciale, questa dizione è da preferirsi a tardiglaciale), postglacial (postglaciale). il termine lgm ha origine da una sintesi degli studi sulle variazioni del livello marino, delle temperature della superficie del mare (sst) ottenute dalle associazioni dei foraminiferi planctonici e dei rapporti isotopici ottenuti dai foraminiferi bentonici. questi indicatori forniscono evidenze concordanti sull’esistenza, nell’ambito dell’ultima glaciazione, di un intervallo in cui i ghiacciai continentali raggiunsero il loro massimo volume integrato. il termine ha quindi una connotazione globale e come tale non può essere definito sulla base di indicatori di valore regionale o locale. le manifestazioni locali dell’evento lgm possono essere diverse nelle diverse aree del pianeta. in base ai più recenti dati sul minimo assoluto raggiunto da livello del mare durante il mis (marine isotopic stage) 2, il lgm sarebbe compreso tra 19 e circa 30 mila anni cal bp. sussistono tuttora alcune discrepanze tra i diversi indicatori sulla fase iniziale dell’intervallo. recentemente lgm è stato usato liberamente anche in geologia glaciale per indicare il limite più esterno raggiunto dai margini glaciali durante l’ultima massima avanzata. anche con questa accezione (che è informale) gli autori si riferiscono all’ultimo degli eventi glaciali, delimitato cronostratigraficamente nel late wisconsin / late weichselian / late würm, e si limitano a includerne la fase di massimo, escludendo le fasi di sviluppo e di decadenza. si sottolinea peraltro la valenza cronologica globale del termine lgm. nella scala cronostratigrafica regionale è altresì codificato l’impiego del würm come piano corrispondente all’espressione dell’ultima glaciazione nelle alpi, con le prime fasi datate intorno a 105 ka bp, mentre il sottopiano würm superiore comprende le fasi di avanzata, di massimo e di ritiro glaciale dell’ultimo evento verificatosi tra 30 e 11.5 ka cal bp. il termine tardoglaciale è impiegato con significati diversi, talora comprendendo le fasi della deglaciazione a scala locale, talora indicando l’intervallo di tempo tra l’inizio dell’ interstadio groenlandese 1 e l’inizio dell’olocene (da 14.7 a 11.5 ka cal bp), talora, infine per indicare l’ultima transizione climatica che si estende dalla fine del lgm all’inizio dell’olocene, con significato globale. gli scriventi ritengono che anche il tardoglaciale debba essere connotato da criteri stratigrafici a scala globale. il postglaciale è termine informale, usato con vari significati, e quindi privo di un definito contenuto cronologico e/o stratigrafico. abstract: g. orombelli; c. ravazzi, m.b. cita, on the significance of the terms “lgm”, “lateglacial” and “postglacial” at a global and local scale. (it issn 0394-3356, 2005). the significance of the terms last glacial maximum (lgm), lateglacial, and postglacial, used for late quaternary time intervals with a strong climatic signature, is critically analyzed. the term lgm originated thirty years ago after a synthesis of global evidences for a time interval of maximum integrated ice volume, reached during the last glaciation. the relevant proxies are records of the last ice-volume equivalent minimum sea level, of the isotopic oxygen composition (last maximum δ18 o values) of benthic foraminifera and of the sea surface temperature (sst) estimated on planktonic foraminiferal populations. the global signature of the lgm cannot be reliably recorded by local glacial maxima or temperature minima, and the local expressions of the lgm event in the different parts of the world can be well diverse and asynchronous. the most recent datings of the lgm sea-level low stand constrain this interval between 19 and 30 ka cal bp. several glacial geologists employed the term lgm in a broad, informal sense to identify the most external drift limit reached by glaciers during the last maximum advance within the late wisconsin / late weichselian / late würm. the term lgm is used, internationally, to refer to the maximum phase of the last global event of maximum ice volume, and therefore a definition based on local rock units is questionable. the use of the term lgm to refer to local stratigraphic units or climatic events is misleading and should be abandoned. the chronostratigraphic regional definition of the würm stage in the alps, and of its substages is internationally agreed. the würm stage is the alpine chronostratigraphic expression of the last glaciation, with first events recently dated to 105 ka bp. the late würm indicates the last event of major glacial advance within the last glaciation, including the growth, the maximal phase and the deglaciation, occurred between 30 and 11.5 ka cal bp. the term lateglacial is currently used with different significances, including: (i) the time interval of local deglaciation; (ii) the interval between the onset of greenland interstadial 1 and the holocene beginning (i.e. 14.7 to 11.55 ka cal bp); (iii) the transition between the lgm and the holocene, considered at a global scale, i.e. starting at the lgm end and terminating at the beginning of the holocene. we are in favor of a globally valid and accepted definition. finally, the term postglacial has been used informally with different meanings, and has no precise stratigraphic and/or chronological position. parole chiave: nomenclatura stratigrafica, ultimo massimo glaciale, würm, tardoglaciale, postglaciale. keywords: stratigraphic nomenclature, last glacial maximum, würm, lateglacial, postglacial. il quaternario italian journal of quaternary sciences 18(2), 2005 147-155 148 g. orombelli, c. ravazzi & m.b. cita 1. premessa la stratigrafia del quaternario da sempre ha presentato problemi, sia teorici sia nell’uso pratico. l’intervallo di tempo geologico a noi più prossimo si differenzia dai precedenti per la quantità e la qualità delle testimonianze geologiche, paleobiologiche e paleoambientali lasciate e i criteri stratigrafici normalmente usati si adattano con difficoltà allo studio e classificazione dei sedimenti quaternari, in modo particolare di quelli continentali. vi è addirittura incertezza, attualmente, nella definizione del quaternario e dei suoi limiti e nella sopravvivenza stessa del termine formale (pillans, 2004; pillans & naish, 2004). secondo gibbard (2004) ciò è anche dipeso dall’aver consentito che si radicasse nell’uso una terminologia, senza che fosse appropriatamente definita. e questo atteggiamento continua tutt’ora, con l’introduzione e l’uso di termini “stratigrafici o quasi-stratigrafici …non o mal definiti, quali last glacial maximum, heinrich event, ecc.” a questo proposito, nel volume 17(1) de “il quaternario” è apparsa la nota “definizione di alcuni termini in uso nella cartografia dei depositi quaternari continentali in ambito alpino”, a firma di bini e altri (2004). poiché tale nota intende avviare un dibattito per “fare chiarezza sul significato dei termini, in modo che chi li utilizza o li affronta abbia un quadro di riferimento il più possibile chiaro ed univoco”, interveniamo con alcune osservazioni e puntualizzazioni. intendiamo esaminare l’impiego e il significato dei termini discussi o citati nella nota, “last glacial maximum (lgm)”, “postglaciale”, “pre last glacial maximum (pre-lgm)”, “tardiglaciale”, in ambito globale e a scala regionale. in questa sede non intendiamo, invece, intervenire sulle problematiche del rilevamento e delle unità stratigrafiche utilizzate nella cartografia dei depositi continentali quaternari in ambito alpino. la sigla ka 14c bp indica un’età radiocarbonica non calibrata espressa in migliaia di anni bp, mentre la sigla ka cal bp indica un’età calibrata e/o calendariale espressa in migliaia di anni bp. per le calibrazioni è stato impiegato il programma calib 5.0 (stuiver & reimer, 1986-2005). 2. last glacial maximum (lgm): origine del termine l’espressione last glacial maximum, successivamente abbreviata in lgm, si è diffusa a partire dagli anni ’70, quando, nell’ambito dei progetti climap e specmap, si è raggiunta una “grande sintesi” a sostegno della teoria orbitale dei cambiamenti climatici, sulla base della combinazione di: (i) dati sulle variazioni del livello marino, basati sulla datazione radiometrica di coralli; (ii) dati sulla temperatura della superficie del mare (sst) dedotta dalle associazioni a foraminiferi planctonici (iii); dati isotopici sulle variazioni del volume dei ghiacci continentali, ottenuti dai foraminiferi bentonici ( cronin, 1999). così l’espressione, con iniziali minuscole, compare nel titolo della pubblicazione conclusiva: climap project members (1981) – seasonal reconstruction of the earth’s surface during the last glacial maximum. in tale contesto, questa dizione non è usata, quindi, per alludere ad una condizione di massima espansione areale dei ghiacciai in un’area glacializzata, ma intende invece riferirsi all’ultima fase di massimo volume globale dei ghiacci sui continenti e di minimo livello del mare, in cui si è venuta a trovare la terra intorno a 18 mila anni 14c bp. contemporaneamente, negli studi connessi, volti a valutare l’estensione, il volume ed i caratteri delle grandi calotte glaciali e dei ghiacciai montani durante l’ultima glaciazione, ed in particolare nella sua ultima fase di acme (si veda ad esempio il volume di denton e hughes, 1981 – the last great ice sheets), si impiegano i termini late wisconsin/late weichselian/late würm, con significato cronostratigrafico regionale, per indicare i complessi deposizionali glaciali, deposti tra circa 22-25 e 10 ka 14c bp. nel volume curato da šibrava, bowen e richmond (1986) quaternary glaciations in the northern hemisphere, ricorrono con significato cronostratigrafico i termini late wisconsin (25-10 ka 14c bp), late weichsel ed altri, con caratteri regionali. ove il controllo cronologico è adeguato, le fasi di massima avanzata glaciale all’interno di queste suddivisioni risultano spesso, anche regionalmente, non sincrone tra loro e con la stratigrafia isotopica marina (fullerton & richmond, 1986). secondo quest’ultima si distinguono, nell’ultimo maggiore completo ciclo climatico (interglaciale/glaciale/ interglaciale), gli stadi isotopici marini (mis) 1, 2, 3, 4, 5 (5a, b, c, d, e) e nell’ambito dello stadio 2, compreso tra 12 e 24 ka cal bp (martinson et al., 1987), viene raggiunto il picco più negativo tra 17 e 19 ka cal bp. martinson et al. (1987) non usano il temine lgm. sempre secondo questi autori, lo stadio 2 è compreso tra i punti intermedi delle transizioni che lo delimitano e al suo interno vengono distinti i sottostadi: 2.2 (17.850 – 19.220 a cal bp); 2.21 (19.220 – 23.170 a cal bp); 2.23 (23.170 – 23.930 a cal bp). peraltro i limiti cronologici degli stadi isotopici marini sono stati successivamente modificati. ad esempio, nella curva δ18 o relativa ai foraminiferi bentonici nelle carote v1930/v19-28 (shackleton, 2000), le età dei punti intermedi delle transizioni che delimitano il mis 2 sono rispettivamente 13 e 29 ka cal bp, anziché 12 e 24 ka cal bp. 3. lgm: uso e definizione vent’anni dopo climap, il programma epilog (mix et al., 2001) si è proposto di fare il punto sull’avanzamento delle conoscenze paleoclimatiche relative al lgm, nonché di proporre uno standard climatoe cronostratigrafico per risolvere conflitti di collocazione cronologica e di intepretazione paleoclimatica ottenute con metodi diversi. lgm è uno dei due estremi dell’ultimo ciclo glaciale-interglaciale e rappresenta l’intervallo più recente nel quale i ghiacciai continentali raggiunsero il loro massimo volume integrato, nell’ambito dell’ultima glaciazione (mix et al., 2001). durante questo intervallo di tempo il clima mantenne condizioni di relativa stabilità, ovvero non si sono registrate ampie variazioni su scala millenaria quali quelle che caratterizzano, invece, lo stadio 3 (mix et al., 2001; chappell, 2002). variazioni nel δ18 o nei gusci di foraminiferi planctonici e bentonici, nelle bolle d’aria sigillate nel ghiaccio, nell’acqua interstiziale dei sedimenti oceanici, nonchè la documentazione delle curve del livello del mare, rappresentano i principali proxy data utilizzati per la documentazione stratigrafica del lgm, mentre “i massimi glaciali o le valutazioni di minimi termici locali” (relativi a specifiche aree della terra) “non rappresentano un valido indice del massimo glaciale integrato a livello globale (globally integrated glacial maximum) (mix et al., 2001). la migliore stima di tale massimo glaciale integrato si desume dalle curve di livello del mare equivalente al volume dei ghiacci, che si ottengono previa eliminazione degli effetti isostatici locali, e dai valori δ18 o nei foraminiferi bentonici ” (mix et al., 2001). ne segue che: 1) una definizione del lgm non può essere data sulla base di indicatori di valore regionale o locale; 2) le manifestazioni locali dell’evento lgm possono essere diverse nelle diverse aree del pianeta, compresa la possibile diacronia delle avanzate glaciali considerate a scala locale. per ragioni pratiche, soprattutto nelle aree in cui il record geologico non contiene i proxy data sopra menzionati e per gli scopi della cartografia geologica, è stata proposta anche una definizione cronologica (cronozona) del lgm. mix et al. (2001) propongono i seguenti limiti per la cronozona lgm: 19-23 ka cal bp (16–19,5 ka 14c bp). questa opzione è basata sul lowstand del livello del mare indicato da yokoyama et al. (2000), cioè un intervallo di 3000-4000 anni di lowstand a –135 m in australia. tuttavia, come si vedrà nel paragrafo successivo, questo dato non è sostenuto dalle evidenze più recenti sulle variazioni del livello del mare. viene anche indicata una seconda opzione, che corrisponde ad una forchetta leggermente più ampia (18-24 ka cal bp; 15–20,4 ka 14c bp). sarnthein et al (2003), su base isotopica, suggeriscono una cronozona lgm leggermente più recente: 18-22 ka cal bp. 3.1. lgm e livello del mare inversamente correlato al volume integrato dei ghiacci continentali è il livello del mare: le curve relative alle variazioni del livello del mare (ice-volume equivalent sea level) negli ultimi 135.000 anni (che includono per intero l’ultimo grande ciclo climatico) mostrano un minimo assoluto compreso tra circa 30 e 19 ka cal bp. se lgm è definito dal periodo di massimo volume globale di ghiaccio terrestre, allora questo intervallo è durato circa 10.000 anni, cioè più a lungo dell’intervallo usualmente dedotto dal record isotopico dei foraminiferi bentonici (lambeck e chappell, 2001). secondo lambeck et al. (2002) il volume di ghiaccio continentale si avvicina al suo massimo valore intorno a 30.000 cal bp e rimane circa costante per 11.000 anni sino a 19.000 cal bp. l’ingresso nel lgm è caratterizzato da una caduta del livello del mare di circa 50 m in poche migliaia di anni (fig. 1), l’uscita da una rapida risalita iniziale di 15 m in circa 500 anni, seguita da più lenta risalita nei successivi 2500 anni. segue quindi una rapida risalita di 15 mm/a tra 16 e 9 ka cal bp, interrotta tra 12,5 e 11,5 ka cal bp da un livello stabile durante il dryas recente. pertanto, lambeck et al., 2002, definiscono “the onset of the lgm as the time sea levels first approached their minimum levels at about 30,000 years ago”. in base a questa definizione, lgm avrebbe avuto una durata di circa 10.000 anni e includerebbe sia la culminazione dello stadio 2 che il suo inizio, al limite con lo stadio 3. e’ auspicabile che nei prossimi anni si giunga ad una definizione cronostratigrafica univoca del lgm. 149osservazioni sul significato ... 4. implicazioni in altri settori della geologia del quaternario 4.1. lgm nelle carote di ghiaccio a partire dagli anni ’90 la dizione lgm viene comunemente usata anche nelle pubblicazioni sulle carote di ghiaccio, per indicare il ristretto intervallo di tempo di massimo volume dei ghiacci/minimo livello del mare, evidenziato dalla stratigrafia isotopica marina, intervallo di tempo in cui si registrano condizioni generali di minimo termico nelle regioni polari. in realtà la documentazione fornita dalle carote di ghiaccio è assai articolata e i diversi indicatori climatici forniscono una storia climatica complessa, con differenze anche marcate tra i due emisferi e pure in ambito regionale. così, nelle carote prelevate in groenlandia, tra 25 e 19 ka cal bp vi è un ampio minimo δ18 o (peraltro interrotto da un picco intorno a 21 ka, interstadio 2, gi2, walker et al., 1999) mentre in precedenza dominano le fluttuazioni ad alta frequenza dei cicli d/o (dansgaard et al. 1993). in antartide, invece, come recentemente indicato con elevato dettaglio nella carota epica edc96, vi è un ampio e sostanzialmente piatto minimo δd (temperatura sul sito), tra circa 28 e 18 ka cal bp (fig. 1), mentre l’eccesso di deuterio, interpretato come indicatore della temperatura nell’area sorgente dell’umidità (l’oceano meridionale), mostra un ampio minimo a 16 20 ka cal bp (stenni et al., 2003). 4.2. lgm in geologia glaciale nello studio dei depositi glaciali continentali la dizione “last glacial maximum” (o altre affini) è stata usata inizialmente per indicare, in senso geografico, il limite più esterno raggiunto dai margini glaciali durante l’ultima massima avanzata, senza una diretta e sicura implicazione temporale. tale massima avanzata era genericamente attribuita al late wisconsin o equivalenti (si veda, ad es., schlüchter, 1982), ma già negli anni ’80 era chiaro che, da luogo a luogo, tale limite non era sincrono e poteva essere più antico o più recente del last glacial maximum (lgm), così come concepito dagli stratigrafi del quaternario marino. un panorama aggiornato di questa problematica si puo’ trovare in clark & mix (2002). percepita questa differenza, molti geologi del glaciale hanno introdotto l’uso del termine lgm con significato locale, per rimarcarne la differenza temporale rispetto al “global lgm” o comunque la sua indipendenza: sono così comparse nella letteratura dizioni come “local last glacial maximum”, “mountain glacier lgm” ”new zealand lgm”, ”local tibetan lgm”, ecc. (ad es. owen et al. 2002; smith et al, 2005). per altro la dizione lgm viene spesso anche usata (vedi florineth e schluchter, 2000) per indicare la fase di picco di avanzata glaciale (intorno a 18-20 ka 14c bp) sincrona del lgm, così come definito in termini di massimo volume globale di ghiaccio. da ultimo, nel lavoro di sintesi sulla storia della calotta eurasiatica (svendsen et al., 2004), lgm viene usato quasi come sinonimo di mis/ois 2 e di late weichselian, sebbene talora si precisi anche la sua durata temporale (20-15 ka). nel complesso, quindi, i geologi del glaciale usano piuttosto liberamente il termine lgm, ma 150 comunque riservandolo al late wisconsin/weichselian ed equivalenti, avendo accertato che localmente si sono prodotte espansioni glaciali più estese in tempi precedenti come, ad esempio, nel settore asiatico (ma non in quello scandinavo) della calotta euroasiatica (svendsen et al., 2004) o nelle alpi francesi (guiter et al., 2005). 5. relazioni tra lgm e la cronostratigrafia alpina per l’ultimo ciclo glaciale: il würm come si è visto, la comunità scientifica internazionale indica come last glacial maximum la fase di massimo volume glaciale globale (segnale isotopico) e di minimo livello del mare equivalente, raggiunti durante l’ultimo ciclo glaciale successivo all’eemiano, e più precisamente durante l’ultima maggiore espansione glaciale, comunemente indicata come late wisconsin (ed equivalenti), in parte coincidente con lo stadio isotopico 2. può essere qui utile puntualizzare lo stato della cronostratigrafia alpina allo scopo di definirne meglio le relazioni con il lgm. la risoluzione n. 6 della subcommission european quaternary stratigraphy (seqs) (chaline & jerz, 1984) attribuisce al würm il significato di piano cronostratigrafico di valore regionale, stabilisce un’area tipo (la regione di isar-loisach in baviera) e indica criteri (litoe palinostratigrafici) per la suddivisione in tre sottopiani (inferiore, medio, superiore) in alcune sezioni scelte. le prime fasi dell’ultima glaciazione, recentemente riconosciute sul versante settentrionale delle alpi, sono datate 105 ka bp (preusser, 2004). il würm superiore viene fatto iniziare – nella sezione (stratotipo) di baumkirken presso innsbruck al passaggio da un’unità di argille lacustri alle ghiaie e quindi ai till soprastanti, che rappresentano l’evidenza dell’ultima fig. 1 tavola stratigrafica relativa all'intervallo 60 10 ka cal bp che illustra alcuni dei dati discussi nel testo. sono stati impiegati i limiti degli stadi isotopici marini indicati da shackleton (2000) e la definizione e suddivisione del würm secondo la risoluzione dell’inqua-seqs (chaline & jerz, 1984). la stratigrafia isotopica grip è tratta da dansgaard et al. (1993); björk et al. (1998); walker et al. (1999). la curva delle variazioni del livello del mare è ripresa da lambeck et al. (2002). la curva δd della carota antartica epica edc96 (stenni et al., 2003) è commentata nel testo. l'interpretazione e l'estensione cronologica del termine tardoglaciale è quella proposta in questo lavoro (discussione nel testo). le fasce barrate indicano ambiti di incertezza dei rispettivi limiti. stratigraphic framework of the time interval between 60 and 10 ka cal bp; mis boundaries according to shackleton (2000). the definition and subdivision of the würm stage follow the inqua-seqs resolution (chaline & jerz, 1984). the grip isotopic stratigraphy is from dansgaard et al. (1993); björk et al. (1998); walker et al., (1999). the sea level curve is from lambeck et al. (2002). the δd curve from the antarctic core epica edc 96 (stenni et al., 2003) is commented in the text. the term lateglacial is used in the sense discussed in the present paper (see text). the crossed pattern shows the interval of time uncertainty of the relevant limits. g. orombelli, c. ravazzi & m.b. cita 151 espansione glaciale. per la sezione di baumkirken sono disponibili un diagramma pollinico e date 14c (fliri et al., 1970; bortenschlager & bortenschlager, 1978): il würm superiore (e l’equivalente geocronologico “würm recente”) inizia quindi intorno a 25 ka 14c bp (ca 29 ka cal bp). sempre la risoluzione n. 6 della seqs indica che il würm termina con l’inizio dell’olocene, con limite attualmente datato 11,5 ka cal bp (gradstein et al., 2004). la letteratura transalpina più recente ha sostanzialmente recepito queste indicazioni, sia pure con limiti temporali un poco diversi. così, ad esempio, campy & arn (1991), van husen (1997), florineth & schluchter (2000), buoncristiani & campy (2001), preusser et al. (2003) e preusser (2004) indicano come late würm l’intervallo 24 -11 ka 14c, circa corrispondente al mis 2. per tutti questi autori il würm superiore include le fasi di ritiro glaciale, complessivamente comprese nel lateglacial (tardoglaciale). su questa base, risulta chiaro che il termine cronostratigrafico würm superiore, così come definito nelle risoluzioni internazionali, ha valenza regionale e comprende interamente l’ultima maggiore espansione glaciale nelle alpi, inclusa la fase di avanzata e quella di deglaciazione, mentre il termine lgm ha valenza globale e riguarda un intervallo di tempo più ristretto. 6. tardoglaciale e postglaciale tardoglaciale (questa dizione è più corretta di "tardiglaciale", in analogia a molti altri termini simili, usati come aggettivi o sostantivi, quali: tardogotico, tardoromanico, tardoneolitico, tardopaleozoico, ecc.; in geologia le parti finali di una suddivisione geocronologica sono spesso indicate premettendo l'aggettivo "tardo", ad es. tardo miocene, tardo quaternario) è la traduzione di lateglacial/spätglazial ed è stata informalmente usata per indicare la fase di transizione climatica successiva al lgm, contrassegnata da riavanzate o stazionamenti, via via più arretrati, degli apparati glaciali, fino alla loro riduzione (nel caso dei ghiacciai montani) a dimensioni circa uguali a quelle attuali. in questo senso, sulle alpi, il tardoglaciale (anche indicato come tardowürm/tardowürmiano) è stato usato, a partire dagli anni ’60, come termine complessivo, per indicare gli stadi glaciali (stadiali) già individuati da penck e brückner (1909), e originariamente attribuiti al “postglaciale – post-würmiano” (si veda maisch, 1982). una vasta bibliografia si è accumulata su questo argomento, con l’introduzione di numerosi nuovi “stadi” con denominazioni locali, particolarmente in austria e in svizzera, ma anche in italia, generalmente non definiti cronologicamente e tra loro distinti e correlati con criteri paleoglaciologici (altitudine del limite delle nevi). van husen (1997) in austria riconosce, dopo il lgm, le fasi di ritiro bühl, steinach, gschnitz, daun, egesen. maisch (1982) in svizzera distingue gli stadi bühl, steinach, gschnitz, clavadel, daun, egesen (distinto in tre sottostadi, max., bockten, kromer), l’ultimo sottostadio potendo già appartenere all’olocene basale (preboreale, kelly et al., 2004). lo stadio bühl da taluni autori non è incluso nel tardoglaciale. tramite date 14c ottenute in successioni polliniche in area alpina è stata proposta una correlazione tra lo stadio gschnitz e il dryas inferiore (oldest dryas) e tentativamente datato intorno a 14 ka 14c bp (van husen, 1997). questa correlazione è tuttavia messa in dubbio da più recenti revisioni del quadro palinostratigrafico del tardoglaciale centro-europeo, che evidenziano come la biozona dryas inferiore (oldest dryas) sia stata impiegata, al di fuori della sua area tipo, in maniera difforme dal significato originario (litt et al., 2003). lo stadio di egesen è stato correlato con il dryas recente (younger dryas) sulla base di datazioni con nuclidi cosmogenici di massi sulle morene deposte dai ghiacciai di aletsch e vadret lagrev in svizzera. nel caso dell’aletsch, per le sue grandi dimensioni e la sua lenta risposta, le morene attribuite allo stadio multifase di egesen si sarebbero formate durante l’ultima sua fase di avanzata, probabilmente nell’olocene basale (kelly et al., 2004). il termine lateglacial (spätglazial) è già impiegato negli anni cinquanta nella letteratura palinologica centro-europea per indicare informalmente un complesso di condizioni climatiche, sedimentologiche e paleogeografiche che precedono l’espansione di foreste di latifoglie termofile con quercus e corylus al termine dell’ultima glaciazione (firbas, 1954; welten, 1979). il limite inferiore dello spätglazial, nel senso impiegato dalle scuole di firbas e di welten, non era ben definito in termini stratigrafici, per ragioni tecniche connesse con i limiti delle capacità di perforazione di quegli anni, che non consentivano di raggiungere i livelli più profondi dei bacini lacustri e di torbiera (welten, 1979), nonché per via dello scarso contenuto pollinico di questi depositi. nell’ultimo cinquantennio è stata dimostrata la correlabilità tra criteri palinologici, isotopici (ottenuti nelle carote di ghiaccio) e dendrocronologici per il limite superiore del lateglacial. questo limite è posto in maniera univoca in corrispondenza di un brusco evento isotopico, palinologico e dendrocronologico a 11.550 ± 50 anni cal bp (10.000 14c bp), che coincide con l’inizio dell’olocene (dansgaard et al., 1989; jonhsen et al., 1997; friedrich et al., 1999; merkt & muller, 1999; litt et al ., 2003) ed è accettato dalla international commission on stratigraphy (gibbard, 2004). per quanto riguarda la caratterizzazione della parte iniziale del lateglacial non vi è ancora accordo unanime nella letteratura. la maggior parte degli autori dell’europa centrooccidentale sono orientati ad assumere come limite pleniglacial/lateglacial il brusco miglioramento climatico che segna l’inizio del gi-1 (greenland interstadial 1) (circa corrispondente al “bølling-allerød”), posto a 14.700 anni cal bp nel record isotopico della carota grip e a circa 12.500 anni 14c nelle successioni lacustri dell’europa centro-occidentale (johnsen et al., 1997; lowe & walker, 1997; walker, 1999; walker et al., 1999; litt et al., 2003), riprendendo un uso precedente già impiegato in palinostratigrafia nelle medesime regioni (van der hammen et al., 1971). altri autori impiegano il termine con valenza globale e fanno iniziare i l lateglacial al termine del lgm, quindi a circa 18 mila anni cal bp (orombelli & ravazzi, 1996; lambeck et al., 2000); altri ancora lo impiegano con valenza cronostratigrafica regionale, facendo coincidere la base del lateglacial con l’età presunta delle fasi iniziali della deglaciazione locale. seguendo l’uso cronostratigrafico regionale del termine connesso con l’inizio della deglaciazione locale, non sincrono nelle diverse regioni glacializzate, si hanno diverse età d’inizio del lateglacial, osservazioni sul significato ... 152 ad esempio circa 15.8-14.4 mila anni cal bp in scozia (birnie et al., 1993), o 17.5 mila anni cal bp in svizzera (preusser, 2004); inoltre, in questo senso il termine non potrebbe essere impiegato al di fuori delle aree glacializzate. gli scriventi ritengono che il termine lateglacial, come lgm, dovrebbe essere connotato da criteri stratigrafici a scala globale, volti alla valutazione delle trasformazioni che si sono svolte tra la culminazione dell’ultima fase fredda (lgm) e il brusco riscaldamento rilevato, sempre a scala globale, in corrispondenza dell’ inizio dell’olocene. con questo signif icato, i l lateglacial non corrisponde alla deglaciazione postlgm, anche se nelle alpi (ma non in nord-america) la include quasi per intero, salvo gli stadi iniziali da taluni considerati ancora pleniglaciali e salvo una possibile coda (fase kromer dello stadio egesen) nel preboreale. d’altra parte la cronologia dell’ultima deglaciazione nelle alpi è mal definita a causa della scarsità di materiale vegetale, prodotto da piante terrestri, databile con il radiocarbonio. se si fa iniziare l’ultima deglaciazione nel momento in cui i ghiacciai abbandonano definitivamente la posizione raggiunta negli anfiteatri (ove esistono) o nei fondovalle nel würm superiore, allora l’età di 17.5 ka cal bp indicata da niessen & kelts (1989) per la deglaciazione del lago di lugano, e ripresa da preusser (2004), è da considerarsi posteriore all’inizio della deglaciazione. per il versante meridionale delle alpi, le date più antiche e affidabili, in quanto ottenute su legno, e certamente posteriori all’inizio della deglaciazione, sono quelle dei larici di revine, vittorio veneto. per questa località sono riportate età molto vicine a quelle corrispondenti alla fine del lgm (15,2 ka 14c bp secondo friedrich et al., 1999, ovvero 18,6 ka cal bp, calibrazione secondo calib 5.0). nella medesima area di revine, il ghiacciaio si trovava in posizione di massima avanzata poco dopo 17,7 ka 14c bp (pari a circa 21,0 ka cal bp). questa è infatti l’età di legni inclusi nel till della cerchia più esterna dell’anfiteatro di vittorio veneto (bondesan, 1999). tenendo conto di questi dati, ravazzi (2003) adotta un’età di ca 15,5 ka 14c bp (ca 18.9 ka cal bp) per l’inizio della deglaciazione a sud delle alpi. il termine postglacial (post-glacial, postglaciale) è impiegato da un secolo nella letteratura internazionale per indicare l’intervallo di tempo che segue il termine dell’ultimo ciclo di avanzata e ritiro glaciale del pleistocene (webster's revised unabridged dictionary, 1913). il postglacial segue il lateglacial e come tale è generalmente considerato un sinonimo di olocene, anche se privo della connotazione cronostratigrafica di quest’ultimo (roberts, 1989; lowe & walker, 1997). e’ un termine informale, ormai poco utilizzato, preferibilmente da abbandonarsi. 7. proposte le osservazioni qui presentate, circa l’uso dei termini lgm e tardoglaciale in stratigrafia, ne sottolineano la valenza globale, che è andata progressivamente precisandosi a partire dagli anni ’70 con lo sviluppo della stratigrafia dei sedimenti oceanici e dei ghiacci polari. l’analisi svolta nella presente nota ha evidenziato che questi termini hanno preso origine da concetti relativi ad eventi geologici globali registrati nei sedimenti e sono quindi oggetto della stratigrafia ad eventi, di cui anche la climatostratigrafia è parte integrante. per ragioni pratiche, soprattutto nelle aree in cui il record geologico non contiene i proxy data che consentono l’individuazione diretta di tali eventi, è stata proposta anche una definizione cronologica degli eventi, in particolare per i limiti inferiore e superiore del lgm e per il brusco passaggio tra il tardoglaciale e l’olocene. tale impiego dei termini in senso cronostratigrafico può servire anche agli scopi della cartografia geologica regionale, nell’individuazione delle relazioni tra le età dei corpi cartografati e gli eventi globali che controllano e indirizzano la loro formazione. per queste finalità è auspicabile anche lo sviluppo di una cronostratigrafia di riferimento regionale, che tenga in considerazione l’espressione locale diacronica degli eventi e sottolinei i processi di volta in volta attivi nelle diverse aree. la sottocommissione per il quaternario europeo (seqs) dell’inqua da oltre trent’anni si occupa di contribuire allo sviluppo di scale cronostratigrafiche di valore regionale nelle diverse parti d’europa. per quanto riguarda le alpi, vent’anni fa la seqs ha formulato uno schema di riferimento per il pleistocene superiore (chaline & jerz, 1984), tuttora largamente usato da gran parte dei quaternaristi alpini, come evidenziato anche nella presente nota. in particolare, riteniamo che il significato cronostratigrafico attribuito al würm superiore sia stato correttamente precisato dall’istituzione di una sezione tipo, con significato regionale di riferimento per l’inizio dell’ultima espansione glaciale nelle alpi. l’impiego di una sezione tipo in ambito continentale è formalmente corretto, secondo il codice di nomenclatura stratigrafica (salvador, 1994) ed è di particolare utilità nella cartografia geologica. l’intervallo rappresentato dai depositi del würm superiore abbraccia infatti per intero l’ultimo evento di espansione glaciale durante l’ultimo ciclo glaciale-interglaciale (pleistocene superiore), includendo le fasi di avanzata, di massima espansione e di ritiro. ci si augura pertanto che i rilevatori dediti al rilevamento delle unità quaternarie prendano atto dell’esistenza di questi strumenti, utili a fornire un quadro interpretativo a scala extralocale dei processi geologici, che pur trovano espressioni diverse nelle diverse aree geografiche. in questa prospettiva è giocoforza accrescere il patrimonio disponibile di datazioni relative e numeriche – che sul versante italiano delle alpi appare ancora inadeguato a comporre un quadro unitario dello svolgersi dei processi geologici e climatici. per quanto riguarda l’impiego del termine lgm, le affermazioni contenute nel paragrafo 1 dell’articolo di bini et al. (2004) non sono, a parere degli scriventi, accettabili alla luce delle argomentazioni esposte nelle presente nota, come di seguito puntualizzato: 1 lgm ha significato globale, è uno “stato” o “condizione” della terra, quale quello prodottosi l’ultima volta, quando il volume complessivo dei ghiacci continentali ha raggiunto il valore massimo durante l’ultimo ciclo glaciale/interglaciale, intorno a 20.000 anni bp. ha quindi anche una valenza cronologica (pure se ancora da definirsi con precisione). pertanto lgm non ha dirette relazioni con le testimonianze di massima estensione areale, raggiunta g. orombelli, c. ravazzi & m.b. cita localmente dai ghiacciai, come discusso nel capitolo 3 della presente nota. la dizione “lgm locale”, talora usata in studi regionali, vorrebbe indicare l’espressione locale del lgm, in termini di locale massima estensione areale. riteniamo possa essere usata solamente per alludere alla estensione e configurazione dei ghiacciai possedute in una regione durante il lgm, quindi sostanzialmente nell’intervallo di tempo definito da questo termine. 2 lgm per definizione è “massimo”, quindi esclude le fasi di sviluppo ed aumento di volume globale e quelle di decadenza e diminuzione. si tratta di definire la durata e i limiti cronologici del massimo globale. 3 lgm per definizione è “ultimo” e fa pertanto riferimento unicamente all’ultima maggiore espansione glaciale durante l’ultimo ciclo glaciale/interglaciale. nelle alpi è pertanto da inquadrarsi nel würm superiore (late würm), come discusso nel capitolo 5 della presente nota. 4 lgm è un evento sincrono nel senso che è la fase in cui sulla terra il “livello del mare equivalente al volume dei ghiacci” (ice-volume-equivalent sea-level, lambeck & chappell, 2001), cioè la variazione di livello degli oceani depurata degli effetti locali dovuti alla tettonica, ed alla glacioed idro-isostasia, si è mantenuta sui valori negativi più accentuati (-140 m circa). la dizione pre last glacial maximum (pre-lgm), ove la si voglia usare, deve essere in accordo con il significato di lgm come sopra discusso, e comunque sembra agli scriventi una dizione informale, eccessivamente vaga e priva di contenuto. seguendo il significato attribuito da bini et al. (2004) al termine lgm, gli scriventi propongono di utilizzare in sua vece il termine cronostratigrafico würm superiore. pre-lgm a sua volta potrebbe essere sostituito da pre-würm superiore. il tardoglaciale merita un approfondimento, quanto al suo inizio: in particolare occorre chiarire se succede direttamente al lgm o se è da questo separato. qualora questo termine venisse utilizzato, andrebbe precisato con quale significato viene impiegato. se, nello spirito con cui è stata proposta nella nota di bini et al.(2004), la dizione lgm viene sostituita da würm superiore, tutto è risolto, poiché questo include il tardoglaciale. come sottodistinzioni possono essere indicate unità localmente distinte, sulla base di datazioni o di considerazioni sulla posizione nettamente interna ai depositi del würm superiore più esterni. postglaciale è un termine impreciso e non più usato dal punto di vista cronostratigrafico, anche a scala locale. con la p minuscola (quindi anche unità postglaciale upg) è una dizione informale che potrebbe sussistere, poiché risponde, provvisoriamente, all’esigenza di trovare un termine purchessia per indicare un complesso di depositi, che altrimenti riempirebbero di una pletora di nuovi nomi le carte. e’ chiaro che, in ambiente alpino, con questo termine verrebbero accorpati depositi del pleistocene terminale e depositi olocenici. questo accorgimento non dovrebbe, tuttavia, invitare alla pigrizia ed a trascurare un analisi, anche cronologica, più dettagliata di questo complesso di sedimenti, potenziale serbatoio di informazioni geologiche importanti per la comprensione dell’ ambiente attuale e delle sue dinamiche. bibliografia bini a., borsato a., carraro f., carton a., corbari d., cucato m., monegato g. & pellegrini g.b. (2004) definizione di alcuni termini in uso nella cartografia dei depositi quaternari continentali in ambito alpino. il quaternario, 17, 75-82. bini a. & zuccoli l. (2004) glacial history of the southern side of the central alps, italy. in (ehlers j. & gibbard p.l. eds.): quaternary glaciations: extent and chronology. part 1: europe. elsevier, amsterdam. birnie j., gordon j.e., bennett k. and hall a.m. (eds., 1993) the quaternary of shetland. quaternary research association, cambridge. björck s., walker j.c., cwynar c.l., johnsen s., knudsen k.l., lowe j.j., wohlfarth b., intimate members (1998) an event stratigraphy for the last termination in ther north atlantic region based on the greenland ice-core record: a proposal by the intimate group. journal quat. sci., 13 (4), 283292. bondesan a. (1999) una nuova data 14c nell’anfiteatro morenico di vittorio veneto e la costruzione del suo sandur (pianura del f. meschio). 8th italian glaciological meeting ‘alpine glaciers and climate change’, abstract volume, 87-89. bortenschlager i., bortenschlager s. (1978) pollenanalytische untersuchung am bänderton von baumkirchen (inntal, tirol). zeitschrift für gletscherkunde und glazialgeologie, 14 (1), 95103. buoncristiani j.f. & campy m. (2001) late pleistocene detrital yield of the jura glacier, france. quat. res., 56, 51-61. campy m. & arn r. (1991) the jura glaciers: paleogeography in the würmian circum-alpine zone. boreas, 20, 17-27. chaline j., jerz h. (1984) arbeitsergebnisse der subkommission für europäische quartärstratigraphie. stratotypen des würm-glazials . eiszeitalter und gegenwart, 35, 185206. chappell j. (2002) sea level changes forced ice breakouts in the last glacial cycle: new results from coral terraces. quat. sci. rev., 21, 12291240. clark p.v. & mix a.c. (eds. 2002) ice sheets and sea level of the last glacial maximum. quat. sci. rev., 21, 1-454. climap project members (1981) seasonal reconstruction of the earth’s surface during the last glacial maximum. map and chart series no. 36, geol. soc. america. cronin t.m. (1999) principles of paleoclimatology. columbia university press, new york, 560 pp. dansgaard w., white j.w.c., johnsen s.j. (1989) the abrupt termination of the younger dryas climate 153osservazioni sul significato ... event. nature, 339, 532-534. dansgaard w., johnsen s., clausen h.b., dahl-jensen d., gundestrup n., hammer c., hvidberg c.s., steffensen j.p., sveinbjörnsdottir a.e., jouzel j., & bond g., (1993) evidence for general instability of past climate from a 250-kyr ice-core record. nature, 364, 218-220. denton g.h., heusser c.j. et al. (1999) interhemispheric linkage of paleoclimate during the last glaciation. geogr. ann., 81 a, 107-153. denton g.h. & hughes t.j. (1981) the last great ice sheets. john wiley & sons, new york, 484 pp. firbas f. (1954) die synchronisierung der mitteleuropäischen pollendiagramme . danm. geol. unders., 80, 12-21. fliri f., bortenshlager s., felber h., heissel w., hilscher h., resch w. (1970) der bänderton von baumkirchen (inntal, tirol) . zeitschrift für glescherkunde und glazialgeologie, 6 (1-2), 5-35. florineth d., schlüchter c. (2000) alpine evidence for atmospheric circulation patterns in europe during the last glacial maximum. quat. res., 54, 295308. friedrich m., kromer b., spurk m., hofmann j., kaiser k.f. (1999) palaeo-environment and rsdiocarbon calibration as derived from late glacial / early holocene tree-ring chronologies. quat. int., 61, 27-39. fullerton d.s., richmond g.m. (1986) comparison of the marine oxygen isotope record, the eustatic sea level record, and the chronology of glaciation in the united states of america. in: sibrava v., bowen d.q., richmond g.m., (eds., 1986) quaternary glaciations in the northern hemisphere. pergamon, oxford. quat. sci. rev., 5, 197-200. gibbard p. (2004) quaternary…now you see it, now you don’t! quaternary perspectives, 14 (2), 89-91. gradstein f.m., ogg j.g., smith a.g., bleeker w., lourens l.j. (2004) a new geologic time scale with special reference to precambrian and neogene. episodes, 27 (2), 83-100. guiter f., triganon a., andrieu-ponel v., ponel p., hébrand j-p., nicoud g., de beaulieu j-l., brewer s., guibal f. (2005) first evidence of «in situ» eemian sediments on the high plateau of evian (northern alps, france): implications for the chronology of the last glaciation. quat. sc. rev., 24, 35-47. johnsen s.j., clausen h.b., dansgaard w., gundestrup n.s., hammer c.u., andresen u., andersen k.k., hvidberg c.s., dahl-jensen d., steffensen d., shoji j.p., sveinbjornsdottir a.e., white j.w.c., jouzel j., fischer d. (1997) the δ18o record along the greenland ice core project deep ice core and the problem of possible eemian climate instability. journal of geophysical reseach, 102, 26397-26410. kelly m.a., kubik p.w., von blanckenburg f. & schlüchter c. (2004) surface exposure dating of the great aletsch glacier egesen moraine system, western swiss alps, using the cosmogenic nuclide 10be. jour. quat. science, 19, 431-441. lambeck k., yokoyama y., johnston p., purcell a. (2000) global ice volumes at the last glacial maximum and early lateglacial. earth and planet. sci. lett., 181, 513-527. lambeck k., chappell j. (2001) sea level change through the last glacial cycle. science, 292, 679-686. lambeck k., yokoyama y., purcell t. (2002) into and out of the last glacial maximum: sea-level change during oxygen isotope stages 3 and 2. quat. sci. rev., 21, 343-360. litt t., schmincke h.u., kromer b. (2003) environmental response to climatic and volcanic events in central europe during the weichselian lateglacial. quat. sci. rev., 22, 7-32. lowe j.j., walker m.j.c. (1997) reconstructing quaternary environments. 2nd ed. prentice hall, halow. maisch m. (1982) zur gletscher-und klimageschichte des alpinen spätglazials. geohgraphica helvetica, 37, 93-104. martinson d.g., pisias n., hays j.d., imbrie j., moore t.c., shackleton n.j. (1987) age dating and the orbital theory of the ice ages: development of a high-resolution 0 to 300.000–year chronostratigraphy. quat. res., 27, 1-29. merkt j., muller h. (1999) varve chronology of lateglacial in northwest germany from lacustrine sediments of the hamlsee/lower saxony. quat. int., 61, 41-59. mix a.c., bard e., schneider r. (2001) environmental processes of the ice age: land, oceans, glaciers (epilog). quat. sci. rev., 20, 627-657. niessen f. & kelts k. (1989) the deglaciation and holocene sedimentary evolution of southern perialpine lake lugano implications for alpine paleoclimate. eclogae geol. helv., 82/1, 235-263. orombelli g. & ravazzi c. (1996) the late glacial and early holocene: chronology and paleoclimate. il quaternario italian journal of quaternary sciences, 9 (2), 439-444. owen l.a., finkel r.c. & caffee m.w. (2002) a note on the extent of glaciation throughout the himalaya during the global last glacial maximum. quat. sci. rev., 21, 147-157. penck a. e brückner e. (1909) die alpen im eiszeitalter. dritter band. die eiszeiten in den sudalpen und im bereich der ostabdachung der alpen. leipzig. pillans b. (2004) update on defining the quaternary. quaternary perspectives, 129, 88-89. pillans b. & naish t. (2004) defining the quaternary. quat. sci. rev., 23, 2271-2282. preusser f. (2004) towards a chronology of the late pleistocene in the northern alpine foreland. boreas, 33, 195-210. preusser f., geyth m.a., schlüchter c. (2003) -timing of late pleistocene climate change in lowland switzerland. quat. sci. rev., 22, 1435-1445. preusser f. & schlüchter c. (eds. 2004) quaternary perspectives. inqua newsletter, 14, 2 (www.elsevier.com/locate/qp). ravazzi c. (2003) an overview of the quaternary continental stratigraphic units based on biological and climatic events in italy. il quaternario – italian journal of quaternary sciences, 16 (1bis): 11-18. roberts n. (1989) the holocene. an environmental 154 g. orombelli, c. ravazzi & m.b. cita history. blackwell, oxford. salvador a. (ed. 1994) international stratigraphic code. second ed. the geological society of america. sarnthein m., gersonde r., niebler s., pflaumann u., spielhagen r., thiede j., wefer g., weinelt m. (2003) overview of glacial atlantic ocean mapping (glamap 2000). paleoceanography, 18 (2). 10.1029/2002pa000769. schaefer-neth c., paul a. (2003) the atlantic ocean at the last glacial maximum: 1. objective mapping of the glamap sea-surface conditions. in (wefer g., mulitza s., ratmeyer v., eds.): the south atlantic in the late quaternary: reconstruction of material budgets and current systems. springer, berlin. pp. 531-548. schlüchter c. (1982) das maximum der letzen eiszeit, dargestellt anhand der verhaeltnisse im nordlichen alpenvorland der schweiz . phys. geographie, 5, 27-29. univ zürich, geogr. institut. shackleton n. j. (2000) the 100,000-year ice-age cycle identified and found to lag temperature, carbon dioxyde, and orbital eccentricity. science, 289, 1897-1902. sibrava v., bowen d.q., richmond g.m. (eds., 1986) quaternary glaciations in the northern hemisphere. pergamon, oxford. quat. sci. rev., 5, 514 pp. smith j.a., seltzer g., farber d.l., rodbell & finkel r.c. (2005 last glacial maximum in the tropical andes, science, 308, 678-681. stenni b., jouzel j. et al. (2003) a late-glacial highresolution site and source temperature record derived from the epica dome c isotope records (east antarctica). earth. plan. sc. lett., 217, 183195. stuiver m., reimer p. (1986-2005) calib radiocarbon calibration program. version 5.0. disponibile al calib website: http://www.calib.org. svendsen j.i., alexanderson h. et al. (2004) late quaternary ice sheet history of northern eurasia. quat. sc. rev., 23, 1229-1271. van der hammen t., wijmstra t.a., zagwijn w.h. (1971) the floral record of the late cenozoic of europe. in (turekian k.k., ed.): the late cenozoic glacial ages. yale university. pp. 391-424. van husen d. (1997) lgm and late-glacial fluctuations in the eastern alps. quat. int., 38/39, 109118. waelbroeck, c.; labeyrie, l.; michel, e.; duplessy, j.c.; mcmanus, j.f.; lambeck, k.; balbon, e.; et. al. (2002) sea-level and deep water temperature changes derived from benthic foraminifera isotopic records. quat. sci. rev., 21, 295-305 walker m.j.c. (1999) rapid climate change during the last glacial-interglacial transition; implications for stratigraphic subdivision, correlation and dating. global and planetary change, 30, 59-72. walker m.j.c., björck s., lowe j.j., cwynar l.c., johnsen s., knudsen k.l., wohlfarth b., intimate group (1999) isotopic “events” in the grip ice core: a stratotype for the late pleistocene. quat. sci. rev., 18, 1143-1150. webster's revised unabridged dictionary, 1913 c. & g. merriam co., springfield, mass. welten m. (1979) late glacial and late weichselian (spätglazial und spät-würm): a comment. boreas, 8, 396. yokoyama y., lambeck k., de deckker p., johnston p., fifleld k. (2000) timing of the last glacial maximum from observed sea-level minima. nature, 406, 713-716. 155 ms. ricevuto il 17 maggio 2005 testo definitivo ricevuto il 17 maggio 2005 ms. received: may 17, 2005 final text received: may 17, 2005 osservazioni sul significato ... sess 2_16022011_tpr3.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 comparison between lake-level changes, pollen and sedimentological data at lago di mezzano (vt), central italy laura sadori 1 & carlo giraudi 2 1 università la sapienza, roma 2 enea,c.r. saluggia, saluggia (vc) corresponding author: l. sadori <laura.sadori@uniroma1.it> abstract: sadori l. & giraudi c., comparison between lake-level changes, pollen and sedimentological data at lago di mezzano (vt), central italy. (it issn 0394-3356, 2011) results from geomorphological investigations in the catchment of lago di mezzano (vt) have been compared with data from a long sediment core sampled in the lake center. the palaeoenvironmental reconstruction was based on vegetation (deduced from pollen and microcharcoal) and hydrological (reconstructed through lake-level) changes . riassunto: sadori l. & giraudi c., confronto tra variazione di livelli lacustri, dati palinologici e sedimentologi al lago di mezzano (vt), italia centrale. (it issn 0394-3356, 2011) i risultati ottenuti da indagini geomorfologiche condotte nel bacino del lago di mezzano sono stati messi a confronto con dati ottenuti da una carota di sedimento campionata al centro del lago. la ricostruzione paleoambientale è stata basata su variazioni vegetazionali, dedotte dal polline e dai micro carboni, e idrologiche, ricostruite tramte le variazioni di livello lacustre. key words: lago di mezzano, lake-level changes, palynology parole chiave: lago di mezzano, variazioni del livello lacustre, palinologia  the mediterranean region possesses a large number of holocene lacustrine records. these terrestrial archives are widespread across a range of environments in a region that is located at the transition between high and low latitude influences. regional palaeoenvironmental studies may provide key contributions to the understanding of climate changes in the mediterranean area during the holocene. in this view the comprehension of conditions behind hydrological changes is crucial for the mediterranean area, particularly in relation with the presumed present-day global warming. systematic studies aimed specifically at lake-level reconstructions are still scarce in the mediterranean area (see giraudi et al., 2011 for a review of italian lake-level changes). as pointed out by investigations of the last decade (reed et al., 2001; magny et al., 2007) holocene lake-level data offer independent palaeohydrological data to help refine palynological studies. close examination of pollen records reveals that specific local and regional patterns characterize the postglacial vegetation succession, reflecting climatic differences and intrinsic geological and geomorphological features. additionally, anthropogenic effects are often hard to discern from climate causes, as both can produce similar alterations of natural vegetation successions (sadori et al., 2011). the comparison between geomorphological investigations and sediment proxies from a deep coring carried out at lago di mezzano is proposed to provide new palaeonvironmental data to update and increase data already published (sadori et al., 2004) on the bronze age period. lago di mezzano (latium, central italy, 42°37’n, 11°56’e, 452 m a.s.l.) is a maar lake lying inside the caldera formed by the collapse of the latera volcano. the volcano evolved, starting about 300,000 years ago, mainly during the middle and late middle pleistocene. the whole caldera forms the catchment basin of the olpeta river, and can be divided into many smaller basins: some of these basins are connected by narrow valleys produced by the erosion of the sills of former lakes. lago di mezzano is the youngest of the caldera lakes and fills the bottom of a small crater produced by a phreatomagmatic eruption during the last phases of volcanic activity, about 100,000 years ago (nappi et al., 1995). the lake is 800m wide and has a maximum water depth of 31 m. the surface area is about 0.5 km2, and the catchment area is about 1 km2 with few, very small, surface inflows and one outflow. the present size of the lake is due to reclamation works which can be observed both in aerial photos and in the field. before drainage, the lake catchment was much larger and the water flowed, across a sill at the northeastern margin of the catchment area, to the river olpeta which was the original outflow of the lake. the present outflow (fosso delle volpi) is man made, and other streams, formerly flowing to the lake from the northern basin, were artificially diverted to the 129 130 130 olpeta (fig. 1 and fig. 2). the geological study (giraudi, 2004) of the nonvolcanic sediments has established that inside the caldera di latera some terraced lacustrine sediments, alluvial and colluvial deposits and a limited amount of travertine are exposed. underwater archaeological investigations carried out at the lake bottom during the 70ies and the 90ies revealed traces of bronze age dwellings named m1, m2, and m3 (fig. 2) along the north-eastern arc of the shore (petitti, 2000; sadori et al., 2004). three parallel cores (lmza, lmzb, lmzc) were taken from the centre of the lake, each with a minimum length of 28 m, in may 1995 using a modified livingstone piston corer (usinger corer) by the geoforschungszentrum potsdam. core lmzb was selected for pollen analysis. only preliminary palynological results have so long been published (ramrath et al., 2000; sadori et al., 2004; sadori & giardini., 2007). the chronology of the record, spanning in all 34000 years, and expressed in calendar years bp, was established on the basis of varve counting, nine ams radiocarbon dates, two tephras and interpolated sedimentation rates. the results of the geomorphological and stratigraphical investigations, carried out by means of trenches dug in the area surrounding the lake, allowed to recognize changes in the catchment basin and lake level variations during the late glacial and the holocene (giraudi, 2004). the fig. 1, lago di mezzano. geological sketch map of the basin. 1lacustrine and shore sediments; 2-volcanic materials; 3landslide deposits; 4 alluvial fan; 5terrace scarplet (from sadori et al., 2004) lago di mezzano. carta geologica del bacino di alimentazione. 1sedimenti lacustri e di spiaggia; 2materiali vulcanci; 3accumuli di frana; 4conoide di deiezione; 5scarpate di terrazzo (da sadori et al., 2004) fig. 2, lago di mezzano. a topographical map of the basin; the asterisk marks the location of lmb coring; bbronze age submerged lake dwellings named m1, m2, and m3 lago di mezzano. a carta topografica del bacino, l’asterisco indica la posizione del carotaggio lmzb; binsediamenti perilacustri sommersi dell ’età del bronzo denominati m1, m2 e m3 l. sadori & c. giraudi 131 ms. received: testo ricevuto il radiocarbon data of the holocene sediments show the maximum detail for the last 5000 years. the mezzano lake level oscillations seems in phase with other central italian lakes (giraudi et al., 2011). a good correspondence is found between pollen, microcharcoal, litological curves obtained by the core investigations and lake-level fluctuations deduced by geomorphological investigations for the last five millennia. coherent changes in the different proxies have been taken as evidence of hydrological changes in the catchment, while incoherent ones as indication of human action. references giraudi c. (2004) le oscillazioni di livello del lago di mezzano (valentano –vt): variazioni climatiche ed influenza antropica. il quaternario-italian journal of quaternary science, 17(2/1), 221–230. giraudi c, magny m, zanchetta g & drysdale r. (2011) the holocene climatic evolution of the mediterranean italy: a review of the continental geological data. in: roberts n., sadori l., pérez obiol r. mid-holocene climate change in the mediterranean region and its consequences, s,i. the holocene, doi: 10.1177/0959683610377529 magny m., de beaulieu j.-l., drescher-schneider r., vannière b,, walter-simonnet a.v., miras y. et al. (2007) holocene climate changes in the central mediterranean as recorded by lake-level fluctuations at lake accesa (tuscany, italy). quaternary science reviews 26, 1736–1758. nappi, g., renzulli, a., santi, p. & gillot p, y. (1995) geological evolution and geochronology of the vulsini volcanic district (central italy). bollettino società geologica italiana, 114, 599–613. petitti, p. 2000. la caldera di latera: appunti su materiali di nuova scoperta e contatti a lunga distanza. in: negroni catacchio, n. (ed.), preistoria e protostoria in etruria. atti del iv incontro di studi. milano, 141–149. ramrath, a., sadori, l. & negendank, j.f.w. (2000) sediments from lago di mezzano, central italy: a record of late glacial/holocene climatic variations and anthropogenic impact. the holocene 10, 87–95. reed j.m., stevenson, a.c. & juggins, s. (2001) a multi-proxy record of holocene climatic change in southwestern spain: the laguna di medina, cadiz. the holocene 11, 707-719. sadori l. & giardini m. (2008) environmental history in the mediterranean basin: microcharcoal as a tool to disentangle human impact and climate change. in: g. fiorentino and d. magri (eds) charcoals from the past: cultural and palaeoenvironmental implications. bar international series, 1807, 229-236. sadori l., giraudi c., petitti p. & ramrath a. (2004) human impact at lago di mezzano (central italy) during the bronze age: a multidisciplinary approach, quaternary international, 113, 5-17. sadori l., jahns s. & peyron o. (2011) mid-holocene vegetation history of the central mediterranean in: roberts n., sadori l., pérez obiol r. mid-holocene climate change in the mediterranean region and its consequences, s,i. the holocene, doi: 10.1177/0959683610377530.  fig. 3, lago di mezzano: lake-level changes. apresent day and 20th century; b16th and 17th century; cbronze age. m1, m2, and m3 perilacustrine archaeological settlements (sadori l. et al., 2004) lago di mezzano: variazioni dei livelli lacustri. asituazione attuale e del xx secolo; bxvi e xvii secolo; cetà del bronzo. m1, m2 e m3 insediamenti archeologici perilacustri (sadori l. et al., 2004)  january 14, 2011 14 gennaio 2011 comparison between lake-level changes, pollen ... imp. giano-martino aasssseettttoo mmoorrffootteettttoonniiccoo ee mmoorrffoossttrraattiiggrraaffiiccoo ddii aallccuunnii ddeeppoossiittii ccoonnttiinneennttaallii pplleeiissttoocceenniiccii ddeell bbaacciinnoo ddeell ppeerrggoollaa--mmeellaannddrroo ((aappppeennnniinnoo lluuccaannoo)) ssaallvvaattoorree iivvoo ggiiaannoo11 && ccllaauuddiioo mmaarrttiinnoo22 1di.s.g.g., università della basilicata, potenza 2dipartimento di scienze geologiche, università della basilicata, potenza riassunto sono stati investigati i rapporti fra morfologia, stratigrafia e struttura di alcuni depositi conglomeratici continentali affioranti nel bacino intermontano del pergola-melandro, ubicato nella zona assiale dell’appennino lucano. gli aspetti geomorfologici, stratigrafici e neotettonici preliminari dell’area sono stati già oggetto di studio da parte di diversi autori che assegnano un’età plio-pleistocenica alla genesi della depressione tettonica. due sottobacini, conosciuti rispettivamente come s. angelo e brienza, separati da un alto strutturale, costituiscono l’intera depressione colmata da alluvioni ben organizzate nel primo caso e da alluvioni più prossimali con carattere fluvio-torrentizio nel secondo. l’evoluzione geomorfologica e sedimentaria del bacino secondo gli autori è stata scandita da diversi episodi deformativi che hanno coinvolto anche le successioni clastiche e la superficie di erosione sommitale terrazzata del riempimento intravallivo. in questo lavoro vengono analizzati i caratteri stratigrafici della porzione sommitale del riempimento clastico continentale del bacino e gli aspetti relativi al loro stato di deformazione in alcuni settori dei due sottobacini. i rapporti tra le principali strutture tettoniche riconosciute e alcune superfici di erosione modellate sia in depositi clastici quaternari sia nel substrato pre-quaternario hanno contribuito a chiarire alcuni aspetti dell’evoluzione morfotettonica quaternaria dell’area. superfici di erosione e/o paleosuoli nelle successioni clastiche analizzate nei pressi di serra murgia longa hanno permesso di differenziare tre unità deposizionali con una diversa organizzazione dei depositi. l’analisi mesostrutturale ha consentito di riconoscere differenti sistemi di faglie, orientati in direzione antiappenninica ed appenninica, che hanno deformato i depositi clastici del pleistocene inferiore. il sistema antiappenninico, privo di espressione morfologica, che disloca i conglomerati del ciclo basale è suturato verso l’alto da un orizzonte più cementato e mostra un’attività tettonica sinsedimentaria. il sistema appenninico disloca sia l’intera successione clastica infrapleistocenica che i terrazzi di erosione sommitali del fondovalle alluvionale denunciando una attività tettonica più recente. un deposito detritico-alluvionale, in facies di conoide prossimale affiorante nei pressi di santa domenica – è costituito da due unità deposizionali separate da una superficie di erosione e da un paleosuolo fagliato. in alcuni punti il deposito più recente della successione alluvionale del pergola-melandro è vistosamente deformato e ruotato contro monte da una faglia ad andamento appenninico. in conclusione i depositi continentali studiati hanno registrato l’attività di alcuni sistemi di faglie nel corso del pleistocene evidenziando un carattere sinsedimentario per alcune, ed una attività recente e verosimilmente sismogenetica per altre, come risulta dagli elementi morfotettonici e stratigrafici riconosciuti nel bacino. abstract the relationships between some morphostructural and stratigraphic features outcropping in the pergola-melandro intermontane basin have been investigated. tectonic events have conditioned the geomorphological evolution of the basin during pleistocene times. a morphological ridge, constituted by pre-quaternary bedrock, separates the basin in two small sub-basins. the first (s. angelo subbasin) is characterized by alluvial deposits with coarse-grained and pelite facies. in the second one (brienza sub-basin) the alluvial system proximal facies crop out. stratigraphic and structural analyses have been carried out in the upper portion of these continental clastic succession. three sedimentary episodes separated by erosional surfaces and/or palaeosoils are recognised. they reflect different morphoclimatic regimes which occurred in early pleistocene. both ne-sw and nw-se trending fault systems deformed the clastic succession. one can observe that a conglomerate horizon seal a ne-sw sinsedimentary fault, whereas the nw-se-trending faults dissect the entire clastic succession and the erosional terraces, middle pleistocene in age. talus cones constituted by breccia deposits outcropping in the santa domenica area show only two depositional episodes separated by red palaeosoils and erosional surfaces. deposits and palaeosoils have been dissected by nw-se-trending faults. furthermore, the breccias have been tilted counterslope by these faults. stratigraphic and morphotectonic relationships suggest a recent tectonic and seismogenetic activity of this fault systems in the axial zone of the southern apennines. parole chiave: morfotettonica, stratigrafia, quaternario, appennino meridionale. keywords: morphotectonic, stratigraphy, quaternary, southern apennines. il quaternario italian journal of quaternary sciences 1166(2), 2003, 289-297 11.. iinnttrroodduuzziioonnee la valle del pergola-melandro rappresenta una delle numerose depressioni intermontane quaternarie, di origine tettonica, dell’appennino lucano. l’area di studio, localizzata nella zona assiale della catena sudappenninica (fig. 1), è limitata dalla dorsale dei monti della maddalena lungo il bordo occidentale, dal monte arioso e cime contigue su quello orientale. il corso d’acqua principale, allungato in senso appenninico, drena verso nord-ovest in direzione tirrenica e confluisce oltre la zona di soglia a valle dell’abitato di s. angelo le fratte (fig. 1) nel fiume bianco, un affluente di basso rango gerarchico del fiume sele. la depressione tettonica è divisa in due sottobacini, attraversati dai torrenti melandro e pergola, denominati rispettivamente s. 290 s. i. giano & c. martino angelo e brienza (lippmann provansal, 1987; santangelo, 1991); questi ultimi sono separati da un alto strutturale modellato in substrato pre-quaternario, orientato in direzione antiappenninica e ubicato poco a nord dell’abitato di brienza in località s. giuliano. secondo i risultati del presente studio la distribuzione areale della successione continentale infrapleistocenica del bacino mostra una continuità planimetrica dei depositi alluvionali s.l. di s. angelo e brienza rivelando – diversamente da quanto ritenuto da lippmann provansal (1987) e santangelo (1991) secondo cui si tratterebbe di due bacini di sedimentazione separati da uno spartiacque morfologico una originaria continuità di drenaggio tra i torrenti pergola e melandro (fig. 1). nell’ambito della ricostruzione litostratigrafica dell’intera successione continentale quaternaria del bacino del pergola-melandro ancora in corso di studio è stata realizzata una analisi di dettaglio della parte sommitale, in prevalenza conglomeratica, del riempimento alluvionale infrapleistocenico del bacino e di alcuni depositi di versante più recenti che hanno messo in luce diverse unità deposizionali separate da paleosuoli e/o superfici di erosione. inoltre, il confronto tra le forme del rilievo e le strutture fragili rilevate alla mesoscala nei depositi continentali ha permesso di riconoscere i principali lineamenti tettonici che hanno interessato l’area nel corso della sua storia morfoevolutiva. i depositi studiati risultano vistosamente deformati da due sistemi di faglie, uno ad andamento antiappenninico con attività tettonica sinsedimentaria ed assenza di espressione morfologica e l’altro appenninico, più recente dei depositi alluvionali infrapleistocenici del bacino; le faglie appenniniche dislocano sia una superficie di erosione sommitale scolpita nei depositi alluvionali del riempimento intravallivo (lippmann provansal, 1987), che brecce di versante, entrambe profondamente incise e terrazzate dai torrenti pergola e melandro e dai loro affluenti. in tal senso la superficie di erosione sommitale può essere considerata come una superficie di appoggio basale per le coperture sedimentarie più recenti sensu carraro (1996). fig. 1 carta geologica ed ubicazione del bacino del pergola-melandro. nel riquadro sono evidenziati i settori investigati. geological sketch map and location of the pergola-melandro basin. in the frame, the part of the basin investigated as shown. 22.. iinnqquuaaddrraammeennttoo ggeeoollooggiiccoo ee mmoorrffootteettttoonniiccoo la depressione tettonica quaternaria del pergolamelandro (santangelo, 1991) si è impostata in corrispondenza del sovrascorrimento fra diverse unità tettoniche generate dalla deformazione di domini paleogeografici mesozoico-terziari nel corso della tettogenesi appenninica (d’argento et al., 1973). l’unità a tetto è rappresentata da successioni carbonatiche di piattaforma mentre quella a letto da unità pelagiche di tipo lagonegrese (schiattarella et al., 2003). risultano coinvolte nella deformazione neogenica anche successioni silicoclastiche mioceniche depositate in bacini satellite e/o di avanfossa sopra le coltri deformate (pescatore et al., 1999). i depositi pliocenici, in questo settore della catena, sono rappresentati da sporadici lembi di sabbie e conglomerati appartenenti al ciclo di ariano nei pressi di monte la conca e serra piani di mauro (di nocera et al., 1982). a partire dal pliocene superiore – pleistocene inferiore, lungo la fascia assiale della catena sudappenninica le strutture contrazionali neogeniche sono state dislocate da faglie trascorrenti orientate in direzione n120°±10°, n50÷60° e n-s (ortolani et al., 1992; cinque et al., 1993; schiattarella, 1998). l’instaurarsi di un regime tettonico estensionale caratterizzato da faglie ad alto angolo ha favorito la parziale riattivazione di vecchie strutture e la neoformazione di faglie con direzione appenninica e/o antiappenninica come dimostrato da evidenze geomorfologiche e strutturali (ortolani et al., 1992) e dalla sismicità (amato & selvaggi, 1993). gli aspetti geomorfologici, stratigrafici e neotettonici del bacino del pergola-melandro sono stati affrontati da lippmann provansal (1987) e santangelo (1991) che descrivono il riempimento continentale del bacino come una potente successione alluvionale in facies fluvio-torrentizia che, nelle aree depocentrali, raggiunge i 180 metri di spessore (fig. 2). il cosiddetto bacino di s. angelo è riempito da depositi alluvionali ben organizzati mentre il bacino di brienza è colmato da alluvioni più prossimali e poco organizzate, con carattere torrentizio. santangelo (1991) attribuisce alla neotettonica infrapleistocenica la genesi del bacino che avrebbe provocato, tra l’altro, il parziale sbarramento del reticolo idrografico. quest’ultimo si sarebbe evoluto con un meccanismo di antecedenza aggradazionale, con sovralluvionamento a monte della soglia e deposizione della successione alluvionale infrapleistocenica (santangelo, 1991), analogamente a quanto avvenuto nella vicina alta val d’agri (di niro et al., 1992). ulteriori episodi deformativi hanno interessato l’intera area condizionando l’evoluzione successiva del bacino. la superficie sommitale del fondovalle alluvionale – di natura erosionale (lippmann provansal, 1987) – è stata in seguito incisa e terrazzata in un unico ordine dall’erosione regressiva del reticolo idrografico. in particolare i terrazzi del fondovalle rappresentano i lembi incisi di un esteso glacis d’erosione poligenico modellato nel corso del pleistocene medio in un regime morfoclimatico freddo (lippmann provansal, 1987); la loro età è quindi posteriore a tale data. questi terrazzi sono, inoltre, dislocati a quote comprese tra 790 e 560 metri s.l.m. dalla tettonica estensionale plio-quaternaria (santangelo, 1991). la stima dei tassi di sollevamento quaternari, rea291assetto morfotettonico e morfostratigrafico ... f ig . 2 p an or am ic a de ll’ ar ea d i st ud io . in p ri m o p ia n o s o n o v is ib il i le s u p e rf ic i te rr az za te a l t et to d el rie m pi m en to c la st ic o de l b ac in o. p a n o ra m ic v ie w o f th e st u d y a re a sh ow in g th e to p fla tte d e ro si o n a l te rr a ce s o f th e p e rg o la m el an dr o ba si n. 292 lizzata recentemente lungo la zona assiale della catena da schiattarella et al. (2003), ha interessato anche il bacino del pergola-melandro. per il terrazzo di erosione sommitale è stato calcolato un sollevamento regionale pari a 0.99 mm/a, mentre lo slip rate misurato lungo la faglia bordiera del bacino ha fornito un valore di 0.5÷0.8 mm/a nell'intervallo cronologico 1.8÷1.2 ma. la strutturazione della depressione tettonica del pergola-melandro viene attribuita sulla base di considerazioni regionali all’interazione tra sistemi di faglie ad andamento appenninico ed antiappenninico che hanno registrato locali movimenti transtensivi o transpressivi (ortolani et al., 1992). non è ancora noto se la cinematica di apertura del bacino sia avvenuta in un regime tettonico trascorrente (pull-apart basin) oppure estensionale (graben o half-graben). 33.. aannaalliissii ssttrraattiiggrraaffiiccaa ee rraappppoorrttii mmoorrffootteettttoonniiccii i depositi clastici del bacino del pergola-melandro sono formati da una successione continentale composta da facies variabili localmente; si passa, infatti, dalle alluvioni s.s. di s. angelo, rappresentate da una alternanza argilloso-siltosa con intercalazioni conglomeratiche che verso i bordi diventano dominanti, alle successioni fluvio-torrentizie e detritiche di brienza costituite da conglomerati in assetto massivo e da brecce di versante. sono stati studiati i caratteri litostratigrafici della parte sommitale, prevalentemente conglomeratica, del riempimento clastico infrapleistocenico del bacino (denominato informalmente successione alluvionale del pergola-melandro) per uno spessore di circa 50 metri: questi hanno messo in luce tre distinte unità deposizionali (fig. 3) mentre i rapporti tra le mesostrutture fragili rilevate nei depositi clastici e nel terrazzo sommitale del riempimento intravallivo hanno fornito informazioni utili alla comprensione dei caratteri morfoevolutivi dell’area. l’unità deposizionale basale (ab) – ancora in corso di studio – rappresenta buona parte del riempimento clastico del bacino e viene parzialmente trattata in questo lavoro. essa è troncata da una superficie di erosione che costituisce la superficie di appoggio basale per le due successive unità: quella intermedia (ai) e quella sommitale (as). nei pressi di serra murgia longa sono state riconosciute le due unità più recenti (ai e as rispettivamente in fig. 3) che sono rappresentate dal basso da conglomerati poligenici a supporto di matrice argilloso-sabbiosa che passano lateralmente ad argille siltose grigioverdi contenenti livelli di conglomerati e sabbie. la giacitura discordante del corpo, che immerge a no di oltre 30°, rispetto al terrazzo inciso di quota 630 metri s.l.m. indica un’attività tettonica successiva alla sua formazione. il passaggio al deposito sovrastante (as) costituito da conglomerati massivi, con clasti di natura carbonatica e silicea, a supporto di matrice sabbiosa di colore rosso intenso è marcato da una netta superficie di erosione. si tratta in entrambi i casi di depositi in facies di conoide alluvionale generati in differenti contesti morfoclimatici. l’intera successione è attualmente incisa e terrazzata dal torrente pergola. l’analisi mesostrutturale effettuata nella frazione esclusivamente conglomeratica del deposito dell’unità intermedia (ai) ha fornito i dati sulle faglie ad alto angolo presenti caratterizzate da una cinematica diretta o leggermente obliqua. sono ben documentati i sistemi di faglia orientati in direzione n10÷30°, n60÷80° e n100÷110° (fig. 4), ma risulta più evidente il trend appenninico n160÷170° individuato da coppie coniugate di faglie. e’ stato osservato che il sistema n60÷80° disloca i conglomerati dell’unità basale ma è suturato verso l’alto da un orizzonte più cementato a testimonianza di un’attività tettonica sinsedimentaria (fig. 5). il sistema n100÷110° attraversa invece l’intera successione dislocando di oltre 10 metri il terrazzo sommitale di serra murgia longa che si dipana da circa 760 a 625 metri s.l.m. già interrotto in altri punti da altre scarpate di faglia con rigetti morfologici decametrici. in sezione trasversale queste scarpate mostrano versanti regolarizzati con profilo rettilineo e inclinazione intorno ai 40÷45°; il loro andamento planimetrico, ben evidente in aerofoto, si sviluppa in modo regolare e lineare da un bordo all’altro del terrazzo che attraversano. una ampia fascia di deformazione si osserva nei conglomerati dell’unità basale del torrente fragneto. i clasti, per alcuni metri, sono verticalizzati ed orientati in direzione appenninica (n160÷170°) mentre lateralmente è presente una frattura beante di circa 50÷60 cm con pareti orientate nella stessa direzione e parzialmente riempita da ciottoli del deposito sovrastante. una superficie di erosione tronca i conglomerati infrapleistocenici dell’unita basale (ab) e costituisce la superficie di appoggio basale (carraro, 1996) per un deposito alluvionale più recente ed incastrato morfologicamente nel precedente, ascrivibile seppur dubitativamente al pleistocene superiore? olocene, costituito da ghiaie carbonatiche, di dimensioni metriche e prive di matrice, che passano verso l’alto a sabbie di colore marrone con rari ciottoli centimetrici. si può quindi affermare che il sistema di faglie n60÷80° è stato parzialmente attivo durante la deposizione delle alluvioni del pergola-melandro interrompendo l’attività nel corso del pleistocene inferiore. il sistema di faglie n160÷170° è stato attivo, invece, dopo il modellamento del glacis erosionale mediopleistocenico. nei pressi dell’abitato di brienza, in un taglio artificiale di circa 10 metri (fig. 6), affiora un deposito conglomeratico immergente a nord-est di circa 30÷35° e costituito dal basso verso l’alto: da clasti di natura prevalentemente carbonatica e subordinatamene silicea, a supporto di matrice sabbioso-argillosa marrone e con intercalazioni di lenti sabbiose centimetriche che rappresentano la parte finale dell’unità basale (ab in fig. 3). quest’ultima è troncata a tetto da una superficie di erosione che rappresenta la superficie di appoggio basale di un paleosuolo di spessore metrico costituito da argilla siltosa di colore rosso marrone scuro con pezzame litoide a spigoli vivi di natura carbonatica (pc in fig. 3). un banco conglomeratico più cementato segna l’inizio della successiva unità deposizionale (ai in fig. 3) caratterizzata da conglomerati con clasti di natura carbonatica e silicea, ben organizzati che immergono a nord-est di 8÷10° e passano lateralmente a silt argillosi e sabbie siltose giallastre con intercalazioni di lenti conglomeratiche. l’organizzazione interna del deposito risulta correlabile a quella descritta in precedenza a serra murgia longa ed evidenzia, in questo settore, una continuità negli apporti. una nuova superficie di erosione separa il deposito dall’unità sovrastante (as in fig. 3) rappresens. i. giano & c. martino 293 f ig . 3 s tr at ig ra fia s ch em at ic a de l b ac in o de l p er go la -m el an dr o (d a s an ta ng el o, 1 99 1, m od ifi ca to ). l e ar ee r iq ua dr at e ra pp re se nt an o la p or zi on e di s uc ce ss io ne in ve st ig at a de lle a llu vi on i d el p er go la -m el an dr o. s tr at ig ra ph ic lo gs o f t he p er go la -m el an dr o ba si n (a fte r s an ta ng el o, 1 99 1, m od ifi ed ). in th e fr am e, th e po rt io n of p er go la -m el an dr o al lu vi al s uc ce ss io n in ve st ig at ed . assetto morfotettonico e morfostratigrafico ... 294 tata da conglomerati massivi, di natura carbonatica, a supporto di matrice sabbioso-argillosa rossastra. il corpo, spesso da pochi centimetri fino a circa 3 metri, costituisce l’ultimo evento deposizionale del riempimento infrapleistocenico prima della formazione del glacis erosionale (lippmann provansal, 1987) e prima della successiva profonda incisione e terrazzamento ad opera del torrente pergola e dei suoi affluenti a cui seguono episodi di sedimentazione altopleistocenici non oggetto di questa nota. nel suo insieme l’organizzazione del deposito riflette i caratteri sedimentari tipici di un sistema di conoide alluvionale che passava lateralmente ad aree sottoalimentate con scarsa capacità di drenaggio. nei pressi di santa domenica affiora una successione detritico-alluvionale in facies di conoide prossimale (fig. 7). il deposito, inciso da corsi d’acqua di basso ordine gerarchico, mostra due unità deposizionali (denominate di e ds in fig. 3) separate da una superficie di erosione a tratti fossilizzata da un paleosuolo argilloso di colore marrone rossastro scuro spesso circa 50 cm e con al suo interno pezzame calcareo (pd3 in fig. 3). l’intero corpo, che supera i 30 metri di spessore, viene in alcuni punti ruotato contro monte di circa 30° da una faglia ad alto angolo con direzione appenninica. il paleosuolo pd3 è inoltre dislocato di qualche centimetro da una faglia diretta a direzione appenninica. si tratta di due segmenti isolati della faglia principale appenninica che borda sul lato orientale i monti della maddalena e che attraversa l’intero bacino. la prima unità (di in fig. 3) mostra due distinti momenti di aggradazione separati da paleosuoli argillosi di colore marrone rossastro scuro spessi alcuni centimetri (pd1 e pd2 in fig. 3). poche decine di centimetri sopra il paleosuolo pd1 è presente un livello pelitico potente alcuni centimetri costituito da argilla plastica grigio-verde. il deposito, con strati centimetrici, è formato da brecciole a clasti carbonatici e supporto di matrice sabbiosa calcarea di colore bianco; fig. 4 proiezione stereografica (reticolo di wulff, emisfero inferiore) delle faglie rilevate nei conglomerati del pergolamelandro. le frecce indicano il verso di scorrimento del blocco di tetto. stereonet (wulff net, lower emisphere) of the faults measured in the conglomerate of the pergola-melandro basin. the arrows show the hanging wall displacement. fig. 5 aff ioramento conglomeratico nei pressi di serra murgia longa. la faglia sulla destra è fossilizzata da un livello di conglomerati più cementati mentre quella sulla sinistra taglia l’intera successione. outcrop of the murgia longa conglomerate. a conglomerate bed overlies the fault on the right whereas the fault on the left dissects the entire succession. sono presenti inoltre blocchi isolati di dimensioni metriche. i caratteri litologici riflettono diversi momenti di deposizione legati a fattori climatici nell’ambito di un unico episodio di sedimentazione. una superficie di erosione segna il passaggio al paleosuolo pd3 coperto dai depositi dell’unità successiva (ds in fig. 3) formati da s. i. giano & c. martino brecce con caratteristiche litologiche e deposizionali analoghe a quelle sottostanti. la sommità del detrito è incisa e terrazzata a quote comprese tra 860 e 750 metri s.l.m. e si collega al retrostante versante attraverso un evidente raccordo concavo. a causa della sua posizione decentrata nel bacino il deposito detritico non si correla fisicamente con la successione alluvionale terrazzata del pergola-melandro. le superfici terrazzate modellate nel detrito di versante risultano però incastrate all’interno di alcuni terrazzi erosionali in substrato pre-quaternario posti ad una quota di circa 890 metri s.l.m. che si raccordano – a loro volta – ai terrazzi sommitali della successione alluvionale del bacino. e’ possibile allora considerare il corpo detritico più recente o al massimo coevo dell’ultima unità litostratigrafica riconosciuta nella successione alluvionale infrapleistocenica del bacino (as in fig. 3) collocandosi nella parte medio-alta del pleistocene medio. 44.. ddiissccuussssiioonnee ee ccoonncclluussiioonnii l’analisi stratigrafica e morfostrutturale della porzione sommitale del riempimento alluvionale infrapleistocenico affiorante nel bacino (successione alluvionale del pergola-melandro) ha consentito di chiarire alcuni aspetti sull’evoluzione sedimentaria e morfotettonica recente dell’area (fig. 8). sono state riconosciute tre distinte unità litostratigrafiche (ab, ai e as in fig. 3) separate da paleosuoli e da superfici di erosione. la distribuzione areale dei depositi clastici legati alla seconda ed alla terza unità (ai ed as) ha evidenziato una continuità di drenaggio tra i sottobacini di s. angelo e brienza assente nello stadio di sedimentazione iniziale rappresentato dall’unità basale as (fig. 3). un sistema di faglie orientato in direzione n60÷80° e con attività tettonica sinsedimentaria è stato riconosciuto nei pressi di serra murgia longa dove un orizzonte conglomeratico più cementato fos295 fig. 6 taglio artificiale nei pressi dell’abitato di brienza. sono evidenti le diverse unità deposizionali separate da superfici di erosione e da un paleosuolo. la parete sulla sinistra permette di valutare anche l’inclinazione del deposito rispetto alla superficie terrazzata sommitale. outcrop near brienza town. different deposit ional episodes separated by erosional surfaces and by a palaeosoil are exposed. dip angle of the succession and top of erosional terrace are shown on the left. fig. 7 apparato detritico nei pressi di santa domenica. talus slope deposits in the santa domenica area. assetto morfotettonico e morfostratigrafico ... silizza un piano di faglia (fig. 5). considerata l’età mediopleistocenica attribuita al modellamento del glacis d’erosione al top della successione alluvionale del bacino (lippmann provansal, 1987), l’intervallo di attività del sistema antiappenninico è confinato al pleistocene inferiore. le faglie rilevate alla mesoscala nei conglomerati infrapleistocenici nei pressi del torrente fragneto confermano l’esistenza già riconosciuta dall’analisi geomorfologica di una fascia di deformazione, caratterizzata da faglie con cinematica diretta o obliqua, orientata in direzione n160÷170°, responsabile della strutturazione del bordo occidentale del bacino e che avrebbe guidato anche la incisione della forra di brienza ad opera del torrente pergola. le faglie ad andamento appenninico tagliano l’intera successione clastica dando luogo a scarpate con rigetti decametrici nei terrazzi sommitali distribuiti a quote comprese tra 790 e 600 metri s.l.m. l’età mediopleistocenica dei terrazzi erosionali del riempimento intravallivo (lippmann provansal, 1987) costituisce il limite ante quem per l’attività di queste strutture. la rotazione contro monte di circa 30° di un corpo detritico più giovane della successione alluvionale del pergola-melandro e la presenza di una faglia che disloca di poche decine di centimetri un paleosuolo nei pressi di santa domenica rappresentano le evidenze morfostrutturali della attività più recente del sistema di faglie appenninico lungo il bordo orientale della dorsale dei monti della maddalena (fig. 8). l’esistenza di paleosuoli fagliati datati con il metodo del radiocarbonio a circa 20.000 anni b.p. da giano et al. (2000) appartenenti ad un deposito detritico recente e ubicati lungo la stessa direttrice strutturale nel bordo orientale dei monti della maddalena consente di ipotizzare un’attività tettonica recente anche per le faglie riconosciute in accordo con la sismicità dell’area (amato & selvaggi, 1993). in conclusione, è possibile affermare che i depositi continentali della successione alluvionale del pergola-melandro hanno registrato l’attività di sistemi di faglie antiappenniniche e con attività sinsedimentaria nel corso del pleistocene inferiore, mentre i sistemi di faglie ad andamento appenninico hanno mostrato una attività tettonica più recente e probabilmente sismogenetica come documentato dalla sismicità dell’area (amato & montone, 1997) e dalle evidenze morfostrutturali e stratigrafiche dei depositi più recenti coinvolti nella deformazione. rriinnggrraazziiaammeennttii gli autori sono grati al prof. m. schiattarella per le interessanti discussioni e per la lettura critica del manoscritto. si ringraziano inoltre i due referee anonimi per i preziosi suggerimenti forniti in sede di revisione del testo. lavoro svolto nell’ambito del progetto di ricerca “evoluzione geodinamica quaternaria dell’appennino meridionale sulla base di dati strutturali e paleomagnetici”, cofin murst 2000-2002 (resp. prof. marcello schiattarella). 296 f ig . 8 s ch em a m or fo lo gi co e s tr at ig ra fic o de ll’ ar ea d i s tu di o. s ul la d es tr a so no v is ib ili le tr e un ità d ep os iz io na li de lla s uc ce ss io ne a llu vi on al e de l p er go la -m el an dr o su c ui s i i m po st a il te rr az zo d i er os io ne s om m ita le ; s ul la s in is tr a so no r ip or ta ti i d ep os iti d et rit ic i p iù r ec en ti te rr az za ti e so sp es i r is pe tto a l f on do va lle a ttu al e m a co n un e vi de nt e ra cc or do c on ca vo r is pe tto a l r ili ev o al im en ta to re . m or ph ol og ic al a nd s tr at ig ra ph ic b lo ck d ia gr am o f th e st ud y ar ea . o n th e rig ht t he t hr ee d ep os iti on al u ni ts o f th e p er go la -m el an dr o al lu vi al s uc ce ss io n w ith a bo ve t he t op e ro si on al t er ra ce ; on th e le ft th e te rr ac ed r ec en t b re cc ia s w ith a c on ve x sl op e pr of ile to w ar d th e m ou nt ai n. s. i. giano & c. martino llaavvoorrii cciittaattii amato a. & montone p. (1997) present-day field and active tectonics in southern peninsular italy. geophys. journ. int., 113300, 519-534. amato a. & selvaggi g. (1993) – aftershock location and p-velocity structure in the epicentral region of the 1980 irpinia earthquake. annali di geofisica, 3366, 3-15. carraro f. (1996) – l’importanza dello studio delle superfici di erosione nell’approccio allostratigrafico alla geologia del quaternario. il quaternario, 99, 197-200. cinque a., patacca e., scandone p. & tozzi m. (1993) – quaternary kinematic evolution of the southern apennines. relationship between surfaces geological features and deep lithospheric structures. annali di geofisica, 3366, 249-259. d'argenio b., pescatore t. & scandone p. (1973) schema geologico dell'appennino meridionale (campania e lucania). atti acc. naz. lincei, 118833, 49-72 di niro a., giano s.i. & santangelo n. (1992) – primi dati sull’evoluzione geomorfologica e sedimentaria del bacino dell’alta val d’agri (basilicata). studi geologici camerti, vol. spec. 11999922//11, 257-263. di nocera s., russo b. & torre m. (1982) – i depositi marini del ciclo pliocene inferiore-medio nei dintorni di vietri di potenza. rend. acc. sc. fis. mat., 4455, 87-105. giano s.i., maschio l., alessio m., ferranti l., improta s. & schiattarella m. (2000) radiocarbon dating of active faulting in the agri high valley, southern italy. journal of geodynamics, 2299, 371-386. lippmann provansal m. (1987) l’apennin meridional (italie): etude geomorphologique. these de doctorat d’etat en geographye physique, université d’aix-marseille. ortolani f., pagliuca s., pepe e., schiattarella m. & toccaceli r.m. (1992) active tectonics in the southern apennines: relationships between cover geometries and basement structure. a hypothesis for a geodynamic model. igcp nº 276, newsletter, 55, 413419. pescatore t., renda p., schiattarella m. & tramutoli m. (1999) stratigraphic and structural relationships between meso-cenozoic lagonegro basin and coeval carbonate platforms in southern apennines, italy. tectonophysics, 331155, 269-286. santangelo n. (1991) evoluzione stratigrafica, geomorfologica e neotettonica di alcuni bacini lacustri del confine campano-lucano (italia meridionale). tesi di dottorato in geologia del sedimentario, iii ciclo, università “federico ii” di napoli, 1-109. schiattarella m. (1998) quaternary tectonics of the poll ino ridge, calabria-lucania boundary, southern italy. in: holdsworth r.e., strachan r.a. and dewey j.f. (eds), "continental transpressional and transtensional tectonics". geological society, london, vol. spec., 113355, 341-354. schiattarella m., di leo p., beneduce p. & giano s.i. (2003) – quaternary uplift vs tectonic loading: a case-study from the lucanian apennine, southern italy. quaternary international, 110011--110022, 239-251. 297 ms. ricevuto il 24 giugno 2003 testo definitivo ricevuto il 25 novembre 2003 ms. received: june 24, 2003 final text received: november 25, 2003 assetto morfotettonico e morfostratigrafico ... imp.coltorti& the growth of the chianti ridge: progressive unconformities and depositional sequences in the s. barbara basin (upper valdarno, italy) **mauro coltorti1, silvia ravani1 & federico verrazzani2 1dipartimento di scienze della terra, università di siena, via di laterina, 8 – 53100 siena; -coltorti@unisi.it, ravani@unisi.it 2libero professionista: kfeldspato@inwind.it abstract: m. coltorti et al., the growth of the chianti ridge: progressive unconformities and depositional sequences in the s. barbara basin (upper valdarno, italy). (it issn 0394-3356, 2007). the chianti ridge, elongated in a nw-se direction, separates the upper valdarno from the siena basins. it is made of macigno and scaglia toscana fms. belonging to the tuscan nappe that underlies the ligurian units. inside the upper valdarno basin three main synthems have been identified, separated by major unconformities; from the bottom: 1. castelnuovo synthem, subdivided into spedalino and meleto subsynthems, 2. montevarchi synthem and 3. bucine synthem. the spedalino subsynthem, that unconformably lies over the pre-pliocene bedrock, is made up of thin and laterally discontinuous coarse gravels. the meleto subsynthem, commonly referred to a lacustrine environment, is made of alluvial plain lithofacies, including channel, crevasse splay and swamp depositional systems where a taxodium forest developed and peat accumulated. close to the western margin of the basin these subsynthems are tilted up to 60°. the montevarchi synthem, mainly made of sands and gravels accumulated inside a wide braidplain, and lies unconformably over the previous units. this synthem is tilted eastward up to 20°. finally, the bucine synthem lies unconformably over the previuos synthems generating a fluvial terrace of the arno river. the two lower units date back to the early pliocene. in fact the meleto clays contain mammal remains that can be found in the triversa faunal unit (early villafranchian, late early middle pliocene) as well as in the ruscinian (early pliocene). they are also negatively magnetized and could correspond to the gilbert chron. palaeomagnetic investigations and the presence of aeolian sediments in the montevarchi synthem and cold pollen flora allowed its attribution to the middle and late pliocene. the relationships between the different synthems and the dominant unconformities coupled with thermochronological data recently obtained in the apennine ridge to the east (balestrieri et al., 2003) allow us to establish that the chianti ridge, after a major planation, became the eastern edge of a moderate relief (spedalino subsynthem) that was later transformed into a wide alluvial plain (meleto subsynthem). updoming tilted the previous units before the modelling of a second major unconformity that preceed the deposition of the montevarchi synthem. it is possible that during this period the valdarno was still connected to the siena basin to the west. a third major unconformity followed finally separating the two basins. these deformations occurred almost at sea level. during the early and middle pliocene, the apennine ridge to the east did not exist and the upper valdarno represented the western part of the peri-adriatic basin. the deepening of the drainage network is due to the generalised uplift that in the nearby areas started during the early pleistocene. finally the creation of the present-day apennine watershed was not gradual but very rapid in the geological time scale and started mostly during the early pleistocene. riassunto: m. coltorti et al., il sollevamento della dorsale del chianti: discordanze progressive e sequenze deposizionali nel bacino della s. barbara (valdarno superiore, italia). (it issn 0394-3356, 2007). la dorsale dei monti del chianti, orientata in direzione no-se, separa il bacino della valdarno superiore dal bacino di siena. essa è costituita dai termini più recenti della serie toscana (macigno e scaglia toscana) che sovrascorrono le unità liguri. nel bacino della valdarno superiore sono stati riconosciuti tre sintemi delimitati da importanti superfici di discordanza, dal basso verso l’alto: 1, sintema di castelnuovo, suddiviso nei subsintemi di spedalino e di meleto; 2, sintema di montevarchi; 3, sintema di bucine. il subsintema di spedalino, che giace in discordanza sul substrato pre-pliocenico, è costituito da ghiaie grossolane di modesto spessore e lateralmente discontinue. il subsintema di meleto, generalmente interpretato come un sistema deposizionale lacustre, è caratterizzato da litofacies di pianura alluvionale, differenziate in vari sistemi deposizionali (canali, tracimazioni, paludi, ecc.) dove si depositavano torbe e si sviluppava una foresta a taxodium. nei pressi del margine occidentale del bacino entrambi questi subsintemi sono piegati fino a 60°. il sintema di montevarchi, costituito prevalentemente da sabbie e ghiaie deposte in un’ampia pianura a canali intrecciati, giace in discordanza sulle unità precedenti. questo sintema è piegato verso est fino a 20°. infine, il sintema di bucine giace in discordanza sui precendenti sintemi generando un terrazzo fluviale del fiume arno. le due unità inferiori sono datate al pliocene inferiore. infatti le argille di meleto contengono faune a mammiferi che possono essere attribuite sia al villafranchiano inferiore (tardo pliocene inferiore – pliocene medio, unità di triversa), sia al rusciniano (pliocene inferiore). questi subsintemi sono magnetizzati negativamente e sono attribuiti all’evento di gilbert. le indagini paleomagnetiche, la presenza di depositi eolici e le associazioni polliniche fredde hanno permesso di attribuire il sintema di montevarchi al pliocene medio e superiore. le relazioni esistenti tra i sintemi individuati e le varie discordanze, unitamente ai dati termocronologici, ottenuti recentemente nella dorsale appenninica a est (balestrieri et al., 2003) hanno permesso di stabilire che la dorsale del chianti, dopo un importante spianamento è diventata il margine orientale di un modesto rilievo (subsintema di spedalino) e più tardi un’ampia pianura alluvionale (subsintema di meleto). il sollevamento della dorsale ha piegato le unità precedenti prima del modellamento di una seconda discordanza che ha preceduto la deposizione del sintema di montevarchi. è possibile che durante questo periodo la valdarno fosse ancora connessa con l’adiacente bacino di siena posto più a ovest. successivamente si modella una terza principale discordanza che separa nettamente i due bacini. queste deformazioni avvenivano all’incirca al livello del mare. durante il pliocene inferiore e medio la dorsale appenninica ad est non emergeva e il valdarno superiore rappresentava il settore occidentale del bacino peri-adriatico. l’approfondimento del reticolo di drenaggio è dovuto al sollevamento generalizzato che, nelle aree limitrofe, è iniziato durante il pleistocene inferiore. infine, la creazione dell’attuale spartiacque appenninico non è stata graduale ma molto rapida, a scala dei tempi geologici, ed è iniziata soprattutto durante il pleistocene inferiore. keywords: progressive unconformity, synthem, stratigraphy, facies analysis, chianti ridge, valdarno, apennines, italy. parole chiave: progressive unconformity, sintema, stratigrafia, analisi di facies, dorsale del chianti, valdarno, appennino, italia. il quaternario italian journal of quaternary sciences 20(1), 2007 67-84 ** lavoro presentato al convegno “il sollevamento quaternario nella penisola italiana e nelle aree limitrofe” (roma, 6-8 febbraio 2006) 68 m. coltorti, s. ravani & f. verrazzani 1. introduction the basins on the tyrrhenian side of the italian peninsula are the site of a major controversy because their origin has been associated to ongoing tectonics during the miocene and pliocene. in the past, research was mostly concentrated on the general setting of the basins and their main subdivisions; few investigations were devoted to facies analysis or to their relationship with the nearby ridges that represent the results of the same dynamics. this is probably due to the fact that at the summit of the ridges only erosional features are still preserved. in this paper, we investigate the western side of the upper valdarno basin, one of the most famous neogene-quaternary basins in the northern apennines, because it contains a large number of sites with villafranchian mammal fauna (azzaroli, 1977; gliozzi et al., 1997). in this area, inside the santa barbara peat quarry, the oldest sediments of the basin crop out. there are extensive outcrops and a series of boreholes1 that reach the bedrock evidencing the geometry of the erosional surface at the base of the filling and that of the peat layers. we also investigated the different unconformity bounded stratigraphic units (ubsu) and their sedimentological characteristics and the architectural elements. this allowed us to establish the modifications that occurred in relation with the ongoing tectonics. using all the scarce chronological elements, we tried to associate the changes that affected the basin with the uplift of the ridge, that was one of our main goals. we use a multidisciplinary approach involving geology, geomorphology and facies analysis which gives the best possibilities of understanding how and when the basin and nearby ridge were generated, the dynamics that affected the area and the changes that led to the creation of the present-day landscape. we are going to demonstrate that, contrary to what was previously hypothesised these ridges are the result of folding and not of normal faulting. moreover these movements did not create topography during the pliocene, and the present day setting is mostly the result of differential erosion activated after the movement of generalised uplift that affected the apennines coupled with high angle normal faulting along the tyrrhenian side since the late early pleistocene. 2. the geologic and stratigraphic background the upper valdarno, situated approximately 30 km to the se of florence, was considered a graben or half-graben (trevisan, 1952; nardi, 1961; elter et al., 1975; eva et al., 1978; mariani & prato, 1988; patacca et al., 1990; bertini et al., 1991; lazzarotto & liotta, 1991; sagri 1991; billi et al., 1991; martini & sagri, 1993; bossio et al., 1995). it is characterised by a relatively gently sw margin (chianti ridge) and by a steep ne side (pratomagno ridge) where the main fault system is located. to the w the chianti mountains separate it from the siena basin. it is elongated about 35 km in a nw-se direction with a maximum width of 15 km (fig. 1, 2). 1 thanks to enel fig. 1 a. schematic structural map of the main thrust fronts in the area (from aavv, 1982 modified), fu: cervarola-falterona unit front; tu: tuscan unit front; mtu: mid-tuscany metamorphic unit. b. geological sketch map of the siena basin, chianti mountains, upper valdarno basin and pratomagno ridge. 1: alluvial holocene deposits, 2: pleistocene deposits, 3: marine clay, silty-marly clays of the siena basin (pliocene), 4: marine conglomerates and sandstones of the siena basin (pliocene), 5: santa barbara basin (early-middle pliocene), 6: ligurian units, 7: macigno fm., 8: scaglia toscana fm., 9: cervarola falterona fm., 10: thrust and reverse faults; 11: buried thrust and reverse faults; 12: high-angle normal faults; 13: buried normal faults; 14: lowangle normal faults; cs: castelnuovo dei sabbioni, si: siena. the rectangle shows the studied area. a. schema strutturale dei principali thrust nell’area in esame (aavv, 1982 modificato), fu: unità cervarola-falterona; tu: unità toscane; mtu: unità metamorfiche medio-toscane. b. carta geologica del bacino di siena, monti del chianti, bacino del valdarno superiore e dorsale del pratomagno. 1: depositi alluvionali olocenici, 2. depositi pleistocenici, 3. argille, argille siltoso-marnose marine del bacino di siena (pliocene), 4. conglomerati e sabbie marine del bacino di siena (pliocene), 5. bacino della s. barbara (pliocene inferiore-medio), 6. unità liguri, 7. macigno, 8. scaglia toscana, 9. unità cervarolafalterona, 10. thrust e faglie inverse, 11. thrust e faglie inverse sepolte, 12. faglie normali ad alto angolo, 13. faglie normali sepolte, 14. faglie normali a basso angolo; cs: castelnuovo dei sabbioni, si: siena. il rettangolo indica l’area studiata. 69the growth of the chianti ... fig. 2 geological sketch map of the studied area. 1: holocene fluvial deposits, 2: bucine synthem (late pleistocene), 3: montevarchi synthem (early pliocene-early pleistocene), 4: meleto subsynthem (early-middle pliocene), 5 spedalino subsynthem (early-middle pliocene). bedrock:6: ligurian units (claystones, limestones and marls), 7: macigno fm., 8: scaglia toscana fm., 9: mine area, 10: section tracks; 11: reference topographic points; 12: fault; 13: normal strike and slip; 14: reverse strike and slip; 15: stratigraphic section tracks. cs: castelnuovo dei sabbioni, me: meleto, sb: santa barbara, sda: san donato in avane, ga: gaville, cm: cavriglia monastero, po: poggio secco. schema geologico dell’area studiata. 1: depositi fluviali (olocene), 2: sintema di bucine (pleistocene superiore), 3: sintema di montevarchi (pliocene superiore-pleistocene inferiore), 4: subsintema di meleto (pliocene inferiore-medio), 5: subsintema di spedalino (pliocene inferiore-medio). substrato: 6: unità liguri (argille, calcari e marne), 7: macigno, 8: scaglia toscana, 9: area miniera, 10: traccia sezioni, 11: punti quotati, 12: faglie, 13: strati diritti, 14: strati rovesci; 15: tracce delle sezioni stratigrafiche. cs: castelnuovo dei sabbioni, me: meleto, sb: santa barbara, sda: san donato in avane, ga: gaville, cm: cavriglia monastero, po: poggio secco. 70 the chianti ridge is made by a stack of different tectonic units (elter & sandrelli, 1995; bonini, 1999). the non-metamorphic tuscan nappe is the lowest and it is represented by folded rocks of the macigno sandstones (late oligocene – early miocene) and the scaglia toscana calcarenites, shales and marly limestones (middle cretaceous oligocene). in the eastern side of the chianti ridge, large olistostromes coming from the ligurian and sub-ligurian units (complesso di canetolo, m. morello unit) were deposited inside the macigno fm. (merla,1969; castellucci & cornaggia, 1980; lazzarotto & liotta, 1991; bonini, 1999). similar olistostromes, dispersed in the turbiditic series of the northern apennines, would indicate submarine landslides connected with the progressive migration of the tectonic units towards the foredeep (abbate & sagri, 1981; pini, 1999 and ref. therein). however, to explain the geometry of the different l ithological units castellucci & cornaggia (1980) inferred the presence of a series of overturned folds. in the ne margin of the basin, the tuscan unit tectonically overlies, along w-dipping thrust fronts, a thick turbiditic sandstone succession belonging to the cervarola-falterona unit (merla & abbate, 1967; abbate, 1983; albianelli et al., 1995; bonini, 1999). the various tectono-sedimentary units are the result of the eastward overthrusting of the terrains belonging to the westernmost palaeogeographic domains (elter et al., 1975; ricci lucchi, 1986; bertini et al., 1991; patacca et al., 1990; barchi et al., 1998; finetti et al., 2001). later on, the tuscan and cervarola units were overlain along low angle e-dipping faults by the allochthonous ligurian units, mostly made up of clays, limestones and marls (m. morello unit, complesso caotico) (merla & abbate, 1967; abbate, 1983; boccaletti & coli, 1983; decandia et al., 1993). this rootless tectonic unit (locardi, 1982) was detached in correspondence to the less resistant formations and, at least the more external part is generally considered the result of gravity tectonics known locally as “gravitational f lows” ( i .e. marecchia valley; ruggieri, 1970; veneri, 1986). in fact, the thrusting along the fronts was compensated by a series of detachments in the area now occupied by the ligurian sea. today, the chianti ridge constitutes an antiform with the tuscan unit at the core and ligurian units cropping out in the sw and ne side of the basin. the western margin of the valdarno basin corresponds to the eastern side of this antiform. the evolution of the intermontane basins, including the upper valdarno, is actually very debated. a group of authors interpreted them as graben-like features, created on the rear of the thrust fronts (elter et al., 1975; martini & sagri, 1993; barberi et al., 1995). their origin should be linked to the migration of the apennine chain-foredeep system and therefore their activation and filling should be progressively more recent moving from w to e. many authors associated this migration to a typical subductional model (malinverno & ryan, 1986; patacca et al., 1990; doglioni, 1991). in this model, the extensional movements controlled the fluvial-lacustrine sedimentation. the older extensional basins in the onshore tyrrhenian side would be generated during tortonian-messinian times (azzaroli & lazzeri, 1977; abbate, 1983; bernini et al., 1990 see ref. therein; billi et al., 1991; sagri, 1991; bossio et al., 1995; sagri & magi, 1992; benvenuti, 1993; martini & sagri, 1993; albianelli et al., 1995). more recently, at least four main regional unconformities (messinian, early pliocene, late pliocene, early-middle pleistocene), related to syndepositional events, have been documented (bernini et al., 1990, boccaletti & sani, 1998, boccaletti et al., 1999) and associated by the same authors to the “compressional” style of basin genesis (boccaletti et al., 1995; coltorti & pieruccini, 1997a; 1997b; calamita et al., 1999). lazzarotto & liotta (1991) had already documented the presence of folds inside the fluvial-lacustrine deposits but it was supposed to have only a local significance in an extensional context. finetti et al. (2001, and ref. therein) considered these basins as “perched basins”, quite synonymous of “thrust-top” and “piggy back basins” (grasso & butler, 1991). on the other hand, coltorti & pieruccini (1997a; 1997b), calamita et al. (1999) and, more recently, argnani et al. (2004) attributed these deformations to the surface response of the activity of low-angle e-dipping normal faults. the latter authors agree that the high angle normal faults that today delimit the eastern border of the basin are the result of extensional movements active since the end of the early pleistocene. during our field work, we recognised a series of abrupt contacts between different lithologies that are difficult to explain except with the occurrence of a fault zone with various fault planes that mark the contact between different terrains (figs. 2, 3). in our interpretation, all the tectonic contacts represent e-dipping low angle faults that affected both the tuscany and ligurian terrains. this wide fault zone (fig. 3) is located on the northern continuation of one of more important detachments of the apennine area: the alto-tiberina fault (barchi et al.,1998; boncio et al., 1998; boncio & lavecchia, 2000). although bonini (1999) attributed the evolution of the valdarno basin to the activity of the thrust front along the western side of the chianti ridge, and especially at the contact between tuscan and ligurian units, we collected any evidences that could confirm this hypothesis. 3. the plio-pleistocene deposits the sedimentary filling of the upper valdarno basin is made up of continental sequences attributed to the middle pliocene up to the pleistocene (merla, 1949; abbate, 1983; albianelli et al., 1997; albianelli et al., 2002; napoleone et al., 2003). the contact between the pre-pliocene bedrock and the plio-pleistocene deposits is an abrupt unconformity. inside the filling three stratigraphic units separated by angular unconformities have been recognised by the previous authors (sestini, 1936; azzaroli & lazzeri, 1977; abbate, 1983; billi et al., 1991; bertini et al., 1991; lazzarotto & liotta, 1991; martini & sagri, 1993). more recently, they have been grouped in synthems (sagri & magi, 1992; benvenuti, 1993) and supersynthems (boccaletti et al., 1995; ghinassi & magi, 2004) indicative of three depositional cycles (fig. 4). from the oldest they are: 1, castelnuovo; 2, montevarchi and 3, monticello-ciuffenna. the m. coltorti, s. ravani & f. verrazzani fig. 3 geologic sections through the s. barbara basin as mapped in fig.2. 1: holocene fluvial deposits, 2: bucine synthem, 3: montevarchi synthem, 4: meleto subsynthem, 5 spedalino subsynthem, 6: claystones, limestones and marls (ligurian units), 7: macigno fm., 8: scaglia toscana fm., 9: mine area, 10: fault, ga: gaville; me: meleto, sb: santa barbara, cs: castelnuovo dei sabbioni, l: lignite bank. sezioni geologiche attraverso il bacino della s. barbara così come indicate in fig.2. 1: depositi fluviali olocenici, 2: sintema di bucine, 3: sintema di montevarchi, 4: subsintema di meleto, 5: subsintema di spedalino, 6: argille, calcari e marne (unità liguri), 7: macigno fm., 8: scaglia toscana fm., 9: miniera, 10: faglia, ga: gaville; me: meleto, sb: santa barbara, cs: castelnuovo dei sabbioni, l: banco di lignite. 72 castelnuovo synthem was further subdivided into three units, from the bottom: spedalino gravels and sands, meleto clays and s. donato sands, while the montevarchi synthem includes the terranuova silts, ascione clays and oreno silts and sands (lazzarotto & liotta, 1991; magi & sagri, 1996; bertini, 2001; napoleone et al., 2003; ghinassi & magi, 2004). we continued to use this name for the montevarchi synthem (fig. 4) because we prefer not to proliferate names in the scientific literature. however, it must be stated that this unit has never been described in detail and a type sequence does not exist. moreover we changed the base of the sequence that, after our investigation, is marked by a major unconformity not recognised in the other areas. it separates the castelnuovo from the montevarchi synthem and the s. donato sands belongs to the latter (fig. 4). these last sediments should be interlayered with coarser sediments interpreted as fan delta deposits fed from the east (penna gravels, casa quercia gravels and sands and borro cave sands). along the sw margin of the basin this synthem also includes the montecarlo sands and silts and white aeolian sands (rena bianca sands) interlayered with fluvial sands in the areas close to the alluvial systems located to the west (magi & sagri, 1996; bertini, 2001; ghinassi & magi, 2004). the aeolian sands seem to overlie discontinuously with the s. donato sands (bertini, 2001; ghinassi & magi, 2004; ghinassi et al., 2004). finally the monticello-ciuffenna synthem is made of fluvial deposits (laterina gravels, levane sands and latereto silts) and alluvial fan deposits (loro ciuffenna gravels, tasso sands and pian di tegna silts) (benvenuti, 1993; albianelli et al., 1995). this synthem corresponds with bucine synthem (fig. 4) but this name is here preferred because it was used first in literature (merla & abbate, 1967; azzaroli & lazzeri, 1977; lazzarotto & lotta, 1991). the relationships between the erosional boundary surfaces located: 1. at the base of the sequence; 2. at the base of the montevarchi synthem; 3 at the base of the bucine synthem, generate a progressive unconformity that testifies that the chianti ridge underwent uplift movements while the basin was sinking, hosting a “fluvial-lacustrine sedimentation” (boccaletti et al., 1995; bonini, 1999). a detailed sedimentological analysis of the neogene-quaternary deposits outcropping in the upper valdarno basin was carried out to identify: 1, the facies associations and the architectural elements and, 2, the depositional paleo-environment. in fact, except for some general observations on the main lithological units (abbate, 1983; billi et al., 1991; benvenuti, 1993; martini & sagri, 1993), an exhaustive sedimentological study was made only for the late pliocene aeolian sediments (ghinassi & magi, 2004). our sedimentological analyses were made adopting the miall (1985; 1996) classification. the facies analysis and the different lithofacies associations led to the recognition of many architectural elements used to distinguish between the depositional systems. in the present work three synthems have been recognised, bounded by unconformities partially not consistent with those identified by the previous authors. in fact the castelnuovo synthem corresponds only in part with the basal sequence recognised by the previous authors (fig. 4) because it is made only by the two basal units (spedalino gravels and sands, meleto clays). nevertheless we decided not to create new names in order to avoid a proliferation of new synthems in the geological literature. the contact between the two units is never visible in outcrop and a clear unconformity between the two basal units is not recognisable although we cannot exclude it. however, the facies association changes abruptly. the sediments cropping out in the meleto area (meleto clays of previous authors) have been here considered a subsynthem. it must be pointed out that the textural description is wrong because the clays are subordinate to the sands. the castelnuovo synthem is unconformably overlapped by the montevarchi synthem, that is overlaid by the bucine synthem. at least in the study area there are no facies variations, inside the montevarchi synthem, that should be used for a further subdivision as the previous authors have done in the montevarchi area (sagri & magi, 1992; ghinassi & magi, 2004). in particular, the sediments belonging to each synthem can also lie directly on the bedrock (figs. 2, 3). fig. 4 synthesis of the stratigraphic reconstruction of various authors. sintesi della stratigrafia ricostruita da vari autori. m. coltorti, s. ravani & f. verrazzani 3.1 castelnuovo synthem as mentioned above it is difficult to establish the relationships between the older deposits and if they should be considered a synthem or a subsynthem. in fact, the older is very thin and only locally preserved and the contact with the overlying sediments is never visible in the field. moreover, they are continental deposits where erosional boundaries are common. 3.1.1 spedalino subsynthem the subsynthem is mostly made up of gravels and sands. short stratigraphic sections have been observed at the contact with the macigno fm. the most important sections are located to the north of gaville and near san donato in avane (figs. 2, 7, 8). in the western sector of the basin, close to the chianti ridge, the unconformity at the base of the gravels as well as the overlying layers dip ca. 40°-70° to the ne while to the e they become sub-horizontal (fig. 3). albianelli et al. (2002) mentioned a negative magnetic field of layers inside the spedalino subsynthem but does not show where the sequence was made. on the other hand, albianelli et al. (1997) and napoleone et al. (2003) have clearly shown that a magnetic signal was found in the lower part of the meleto clays. the dating of the base of the unit was therefore obtained extrapolating a constant sedimentological rate. these circular arguments could hide a much older age for the spedalino gravels especially if a major unconformity was to be located at the top of the sequence. facies analysis two stratigraphic sections have been investigated in detail (s1 and s2; figs. 2, 7). the deposits are made up of clast-supported cross-bedded or massive rounded gravels and pebbles (gt and gm) well sorted in places. they generate massive layers up to 3 m thick (fig. 7). the gravels are medium to coarse-grained up to 100 cm in size (s2). the matrix is scarce. the composition is exclusively arenaceous coming from macigno fm. occasionally soft clasts are present. rare lenses of cross-bedded stratified sands are also present (st) (s1; fig. 7). interpretation similar sediments are found in coarse gravelly depositional systems such as a pedemountain stream, braided channels or in proximal alluvial fan deposits. the good sorting of some coarse gm layers suggests the presence of armoured beds that favours a pedemountain stream environment. the gt and thin lenses of st lithofacies are consistent with the same environment. the lateral absence of this unit could suggest that it fills a palaeo-valley cut into the bedrock. the river was located close to a relief and fed by rocks belonging to the macigno fm. 3.1.2 meleto subsynthem it is made by fine sediments, rich in lignite layers. in boreholes, the clays are up to 250 m thick. the most extensive outcrops are located close to the san donato quarry where ca. 15÷20 m thick sequences have been described (figs. 2, 7, 8). these sediments contain remains of mammal bones of tapirus arvernensis, ursus minimus, dicerorhinus sp., leptobos sp. and anancus arvernensis, related to the triversa faunal unit (borselli et al., 1980; de giuli et al., 1983; benvenuti et al., 1995; albianelli et al., 1997), attributed to the early villafranchian. however, a similar association is also found in the ruscinian (early pliocene) (fejfar, 2001). the palinological analyses recognised an association of tropical (taxodiaceae, lauraceae, nyssa, engelhardia, symplocos, ecc.) and temperate taxa (quercus, carpinus, liquidambar, carya, zelkova, populus, acer, betulla, fagus, etc.) (bertini & roiron, 1997) that indicate warm humid climatic conditions favourable to the development of forests and swamps. albianelli et al. (2002) and napoleone et al. (2003) established a reverse polarity for the lowermost part of the sequence and attribute it to the k-interval gauss (c2an.1r) suggesting an age of 3.1 ma for a lignite layer close to the base of the sequence. however, the chronostratigraphic setting is based on the supposed middle pliocene age of the triversa unit, that as previously stated is uncertain. it is also based on the assumption of a constant sedimentation rate and does not consider that the sequence, as we describe in the following paragraphs, is not continuous and is split in two by a major unconformity located between the castelnuovo and the montevarchi synthems. therefore, there is no base for the application of the “count from the top” method as utilised by napoleone et al. (2003). moreover, the whole sequence is clastic and contains a large number of channels that constitute further discontinuities at a local scale. therefore, paleomagnetic investigations can only be used to state that this unit is older than 3.1 ma. facies analysis four stratigraphic sections crop out in the s. barbara and in the s. donato quarries (s3-s6; figs. 2, 7). the meleto subsynthem is mainly made up of grey massive or slightly laminated silty clays (fm, fl), containing wood remains, branches, leaves and pine-cones. these lithofacies are interlayered with thin layers of fine to coarse trough or planar cross bedded sands (st and sp lithofacies respectively), up to 30 cm thick (s5; fig. 7). rarely coarse and medium-grained sands (st, sp), up to 180 cm thick, are present and contain wood fragments (branches and leaves) (s4; fig. 7). in particular, in s4 section a 6 m thick lignite bed has been observed containing thin layers (up to 20÷30 cm thick) of fine to medium grained trough cross bedded sands (st). the rooted parts of many tree trunks in a standing position have also been observed (s3; fig. 7). thicker lignite beds are also well known at depth and were extensively quarried. smaller cascade folds have been observed close to the bedrock. boreholes for lignite exploitation revealed the existence of a narrow synform close to the mountain slope bordered to the east by a minor antiform (fig. 3). the latter is made up of folded sandstones and has been named meleto anticline by bonini (1999). interpretation most of the fine-grained sediments (fm and fl lithofacies association) are overbank deposits (architectural element ff), developed from overbank sheet flow into a large alluvial plain characterised by different subenvironments (channels, crevasse, swamps, etc.). the peat represents the accumulation of the vegetation in the floodplain where a taxodium forest developed from 73the growth of the chianti ... time to time. the thinner sandy lithofacies (st, sp) represents a crevasse channel (architectural element cr) breaking the main channel margin. the progradation from crevasse channel into floodplain creates crevasse splay deposits (cs) that periodically affected the floodplain. these deposits are characterised by st and fl l ithofacies associations. the architecture is coherent with the model 6 (sandy, mixed load meandering rivers) of miall (1985). 3.2 montevarchi synthem the main sections are located inside the s. donato quarry, next to village of meleto, and inside the santa barbara area (figs. 2, 5, 7, 8). close to the study area, in the sw sector of the valdarno basin, at the top of the supposed coheval montevarchi succession, finegrained levels rich in pollen assemblages have been encountered interlayered with aeolian deposits (rena bianca sands, fig. 4). the basal part of the rena bianca sequence is characterised by cold and humid climatic conditions with dry moderate oscillations (bertini, 1994; albianelli et al., 1995). the progressive cooling is testified to by the increase of fagus and picea (bertini & roiron, 1997). the previous authors did not notice the unconformity and included this unit inside the montevarchi synthem. it is related to the late pliocene – early pleistocene interval (billi et al. 1991; bossio et al., 1992; albianelli et al.,1995), because of the finds of late villafranchian faunas (azzaroli, 1977; de giuli, 1983; azzaroli, 1984; benvenuti, 1993). in particular, the base of the rena bianca sands is attributed to ca. 2,58 ma (gelasian) based on paleomagnetic investigations (albianelli et al., 2002; napoleone et al., 2003). the deposition of the aeolian sands occurred during an arid event inside the global climatic deterioration of this period (bertini & roinor, 1997; ghinassi et al, 2004). again, albianelli et al. (2002) and napoleone et al. (2003) suggested an age of 2.64 ma for the top of the meleto subsynthem, but as previosuly stated, they used a constant sedimentation rate between two paleomagnetic intervals the lowermost being located below a major unconformity. facies analysis eight sections (s7-s14) have been investigated (figs. 2, 7). the bottom part of the synthem is mainly characterised by fine to coarse trough or planar crossbeds (st and sp respectively) that show a marked lateral facies variation. load-cast structures are sometimes present. the sands are generally alternated with rich organic matter, grey massive or slightly laminated silty clays, a few cm thick (fm, fl). the lack of sedimentary structures is probably due to strong bioturbation. wood remains are common. moving upwards, there are trough crossbedded gravels (gt) interlayered with fine to coarse trough crossbeds (st) and horizontal laminated sands (sh). rarely ripple cross-lamination is present (sr). moreover rich organic centimetric beds are common (c), although wood remains are generally also scattered inside the sandy lens. the base of the gravels is erosional and marked by pebbles in a scarce sandy matrix. the clasts are generally well rounded and up to 10 cm in diameter. they are mainly derived from the macigno sandstones. however, near poggio secco, some clasts with an orthogneiss composition (f. talarico, pers. com.) have been recognised. the finding of metamorphic clasts, and in particular of “porphiric aplite” whose easternmost outcrop is actually the elba island, is noticed in numerous peri-tyrrhenian basins (tongiorgi & tongiorgi, 1964; bossio et al., 1995). orthogneiss clasts have also been recognised inside the macigno fm. in the chianti mts. (ferrini & pandeli, 1983). interpretation gravelly (gt) and sandy lithofacies (st, sh, sr) are typical of a fluvial channel (ch architectural element; miall, 1985). the tabular gravelly layers identify gravel bars or bedforms (gb architectural element) that are commonly interbedded with sandy bedforms (sb architectural element). the fine-grained lithofacies associations are deposited into the alluvial plain from overbank sheet flows (ff architectural element) and can also fill abandoned channels. these elements are commonly interbedded with sb architectural elements. fine organic sediments are also commonly deposited in the ponds and swamps inside the alluvial plain. sometimes crevasse splays (cs) can spread from crevasse channels into floodplains, interrupting the sedimentation of overbank fines (ff). the sedimentary architecture is typical of a wide alluvial plain with meander belts that 74 fig. 5 s. donato sands belonging to the montevarchi synthem. sabbie di s. donato appartenenti al sintema di montevarchi. m. coltorti, s. ravani & f. verrazzani turn upwards into a braidplain. the fluvial style suggests a gravel-sand or a gravelly meandering river (model 5 and model 6; miall,1985). the orthogneiss clasts come from the erosion of the macigno fm. located to the w. a main provenance from sw for the s. donato sands was also obtained with paleocurrent measurements by albianelli et al. (1995) and ghinassi & magi (2004). 3.3 bucine synthem the sections investigated (s15 and s16) are located near the village of gaville (fig. 2, 6, 7, 8). these are mainly gravels up to 15÷20 m in thickness (fig. 7). they constitute the top of a terrace and there are vertical escarpments (locally named “balze”) that represent the rim of the terrace. the summit of the terrace ranges between 290 m upstream in the castelnuovo dei sabbioni area to 240÷250 m near cavriglia, downstream. the longitudinal slope of the terrace was ca. 0,7%. these deposits contain faunas attributed to the middle-late pleistocene or to the end of the early pleistocene (borselli et al., 1980; de giuli, 1983; benvenuti, 1993; albianelli et al., 1995). in this work we suggest a late pleistocene age for the topmost unit because of its morpho-pedostratigraphic characteristics. in fact, the unit is: 1, the last deposit before the post-glacial incision that led to the present-day setting of the valley and there are no other wide terraces located at minor elevations; 2, the top of the terrace is not weathered by rubified soils with bt or bts profiles, typical of the mis 5 interglacial (coltorti & pieruccini, 2006). this synthem is apparently not deformed. facies analysis the deposits are characterised by clast-supported trough and planar cross-bedded gravels (gt and gp respectively), with a scarce sandy matrix. the clasts are well-rounded or sub-rounded and a sandstone composition predominates. their dimensions range from a few cm up to 20 cm. rarely fine to coarse trough crossbedded or massive sands (st and sm respectively) and silts (fm) up to 30 cm thick are present. the contact with gravels is clearly erosive. in the s15 section the unconformity between the castelnuovo and bucine synthems can be observed. in this sector of the basin the bucine gravels overlie the castelnuovo synthem made up of massive sand (sm) and massive organic rich silts (fm). interpretation the association of the gt and gm lithofacies and the tabular layers characterise gravel bars and bedforms (gb architectural elements: miall, 1985) generating a multilayer infilling. both lithologic, and textural features and lithofacies association are typical of a gravelly braidplain that could belong to the fluvial depositional system of the palaeo-arno river and its tributaries (model 2; miall, 1985). migrating channels and lateralaccretion macroforms (la architectural element) suggest the local onset of a wandering system (model 4; miall, 1985). the gradient of the top depositional surface gently dipping towards the central part of the valley in the area closer to the slope suggests the existence of a series of coalescent alluvial fans. 4. the evolution of the western side of the valdarno basin the beginning of the evolutionary history of the basin is marked by a major unconformity (fig. 9a). it allows us to separate pre-pliocene from plioquaternary tectonic movements. this unconformity cuts the thrust of the tuscan unit over the cervarola unit as well as the detachment at the base of the ligurian units. in fact, the early pliocene sediments lie unconformably over all these tectonic units. this confirms that a large amount of shortening and the later collapse of the ligurian units occurred previous to the early pliocene. it is worth mentioning that, around 5 ma an important rock uplift is recorded with thermochronologic analysis in the apennines to the e of the valdarno basin (abbate et al., 1994; balestrieri et al., 2003). 75 fig. 6 gravel deposits belonging to the bucine synthem cropping out north-east of poggio secco (see also fig.2). depositi ghiaiosi appartenenti al sintema di bucine affioranti a nord-est di poggio secco (cfr. fig.2). the growth of the chianti ... 76 fi g. 7 – s tr at ig ra p hi c se ct io ns r el at ed t o p or tio ns o f th e re co gn is ed s yn th em s in si d e th e s . b ar b ar a b as in : s p ed al in o su b sy nt he m ( s 1 an d s 2) ; m el et o su b sy nt he m ( s 3 to s 6) ; m on te va rc hi sy nt he m (s 7 to s 14 ) a nd b uc in e sy nt he m (s 15 a nd s 16 ). th e th ic kn es s of t he s ec tio ns is in m et er . m : m ud , s : s ilt , s : s an d a nd g : g ra ve l. th e lit ho fa ci es c od es a re r el at ed t o fa ci es c la ss ifi ca tio n of m ia ll (1 99 6) . s ez io ni s tr at ig ra fic he r el at iv e a p or zi on i d ei in te m i r ic on os ci ut i n el b ac in o d el la s . b ar b ar a: s ub si nt em a d i s p ed al in o (s 1; s 2) ; s ub si nt em a d i m el et o (s 3 s 6) ; s in te m a d i m on te va rc hi (s 7 s 14 ) e si nt em a d i b uc in e (s 15 ; s 16 ). lo s p es so re d el le s ez io ni è e sp re ss o in m et ri. m : fa ng o, s : lim o, s : sa b b ia e g : gh ia ia . i co d ic i d el le li to fa ci es s on o re la tiv i a llo s ch em a cl as si fic at iv o d i m ia ll (1 99 6) . m. coltorti, s. ravani & f. verrazzani 77 fi g. 8 s tr at ig ra p hi c se ct io ns r el at ed t o th e re co gn is ed s yn th em s in si d e th e s . b ar b ar a b as in : a . s p ed al in o su b sy nt he m , b . m el et o su b sy nt he m , c . m on te va rc hi s yn th em , d . b uc in e sy nt he m . th e fa ci es a re o f m ia ll (1 99 6) . s 1s 16 m ar k th e re la tiv e p os iti on o f t he p or tio ns o f t he s tr at ig ra p hi c se ct io ns r el at ed t o fi g. 7 . s ez io ni s tr at ig ra fic he s in te tic he r el at iv e ai s in te m i r ic o no sc iu ti al l’i nt er no d el b ac in o d el la s . b ar b ar a: a . s ub si nt em a d i s p ed al in o , b . s ub si nt em a d i m el et o , c . s in te m a d i m o nt ev ar ch i, d . si nt em a d i b uc in e. l e fa ci es s o no r el at iv e al lo s ch em a d i c la ss ifi ca zi o ne u til iz za to d a m ia ll (1 99 6) . s 1s 16 in d ic an o la p o si zi o ne r el at iv a d el le p o rz io ni d el le s ez io ni s tr at ig ra fic he a na liz za te e r el at iv e al la f ig .7 . the growth of the chianti ... these authors suggest that the erosion of a cover up to 5.000 metres thick affected the ligurian units. an important erosion of the ligurian terrains is documented in the area because these terrains are completely missing along the chianti ridge as well as in many surrounding areas. however, in the investigated area, there is no evidences that the ligurian terrains could ever have reached such a thickness. because the base of the sequence is older than 3.5 ma the best place where this erosional event could be recorded is the major unconformity at the base of the filling. rather than explaining the cooling event with uplift followed by denudational process of 5 km of rocks, we suggest that the unusual very rapid erosion was partly associated with the delamination created by the detachment of the ligurian units. a later important planation processes at the beginning of the pliocene is to be added to this event. the origin of this planation is difficult to establish. coltorti & pieruccini (1997a; 1997b; 2002) suggested that in later times, a plain of marine erosion, preserved as a planation surface, was modelled across the apennines as a result of a major transgression during the late early pliocene. we suggest that a similar process could be responsible for most of the erosion associated with the older unconformity . it could correspond to the effects of the zanclean transgression, again a major and long lasting event, that created a major unconformity in continental and marine sequences all around the mediterranean. usually, the sequence stratigraphy suggests that a major unconformity is not modelled during a transgression but during a regression. in our opinion when the sea level drops in correspondence with a cold climate the rivers are overcharged of sediments and do not have the energy to carve an erosional surface. this is also confirmed by the holocene events recorded in many seismic profiles of the italian continental shelf where a major unconformity affects the top of the late pleistocene sequence (chiocci & normark, 1992; lecca et al., 1986; lecca et al., 1998). when sea level rises the rivers have almost no solid load and therefore all the energy is consumed in the erosion of bedrock. the result of such a transgression is a very thin layer of shells and coarse sediments associated with the ravinement surface that could be easily removed or weathered if it is not rapidly buried. this would be one of the reasons for the absence of marine deposits. in fact, the spedalino subsynthem, testifies to a phase of continental erosion after the planation and fills shallow valleys slightly incised into the bedrock. it also testifies to a relief located slightly to the west of the present-day basin. there is no other evidence of coarse clastic sediments coming from the west during the deposition of the meleto subsynthem, when a wide fine grained meander alluvial plain was established locally covered by a taxodium forest and affected by peat deposition. similar to what has been suggested in the nearby tiber basin and in other continental basins in the centralnorthern italy (coltorti & pieruccini, 1997a; 1997b) the peat-rich levels of the valdarno basin could be related to the early pliocene. the negative signal (albianelli et al, 1997) in the lower part of the sequence could correspond to the gilbert magnetic chron and therefore could be older than 4 ma (cande & kent, 1995). these layers are found lying unconformably on the bedrock along the margin of the chianti ridge. in the study area, a major unconformity developed after the deposition of the meleto subsynthem that was tilted up to 40° in proximity of the actual slope (fig. 9b, c and d). because the faults recognised along the western margin of the basin (figs. 2, 3) also dip 50-60° to the nne, and were sealed by the early pliocene sedimentation they underwent the same tilting. if we restore the geometry of the faults to before tilting they become sub-horizontal (x point in fig. 9). we do not know (this is the significance of the question marks in fig. 9c) if during this erosional phase the westward continuation of the oldest units, that is the connection with the siena basin, was interrupted or if this occurred in slightly later times. however, we can suppose that this plain was close to sea level since there are coheval marine sediments in the adjacent siena (to the west) and val di chiana basins (to the south). middle pliocene marine deposits are also found up to 800 m on the cetona mt. (passerini, 1964; liotta & salvatorini, 1994) that constitutes the southern continuation of the chianti ridge. in the southern part of the siena basin, between s. quirico d’orcia and montalcino a general unconformity was recognised but in the northern part, to the west of the study area, this evidence is lacking, most probably for the very few detailed sedimentological investigations (bossio et al., 1995; riforgiato et al., 2005). also in the siena basin, peat layers with trunks are found in the lower part of the sequence interlayered with marine coastal sediments (celle sul rigo fm.; liotta, 1996) recording the lco of g. puncticulata, around 3.6 ma that we suppose could also be a good chronological setting for the final deposition of the meleto clays. the following second cycle, that includes the uppermost coastal and deltaic sediments belongs to the zanclean/piacenzian interval, around 3.1. ma (riforgiato et al., 2005). the unconformity, that has also been recognised in many other tuscan basins would last about 500 ky. although the relationship between the different synthems testifies to a doming of the chianti mts., there is no evidence that it attained the present-day elevation. it could still represent a “drowned sill” between the siena and valdarno basins. similar evidence is widespread in the present-day adriatic basin testified to by seismic profiles to the west of the more external thrust fronts (ori et al., 1986; argnani & gamberi, 1995). in the adriatic sea, antiforms emerged for a short period from the sea level but were later planated and sealed by plio-pleistocene sediments generating progressive unconformities similar to what we observe in the chianti ridge. in the valdarno basin there is no evidence of sediments coming from the erosion of the present-day apennine ridge as also observed in the coheval sedimentation of the east tiber basin, located slightly to the south (coltorti & pieruccini, 1997a; 1997b). the apennine chain, at that time could represent simply another antiform in the peri-adriatic basin that only in later times was transformed into a mountain ridge. in this model, the valdarno basin represented the alluvial plain bordering the palaeo-po plain before the uplift of the apennines. the mountain chain was located further to the west. similar conclusions have recently been reached during the investigation of the barga basin (coltorti et al., sub78 m. coltorti, s. ravani & f. verrazzani mitted) and a large part of the apennine drainage system (coltorti, submitted). the montevarchi synthem, made by coarser sediments, testifies to the presence of a wide braided alluvial plain. the absence of lateral facies variations suggests that the connection with the siena basin, where there are a series of interlayered coastal and fluvial systems, could still be possible (fig. 9c). in fact, the source area for the montevarchi synthem was located to the west as also evidenced from paleocurrent measurements by ghinassi & magi (2004). afterwards also the montevarchi synthem was tilted up to 20° eastwards indicating that the chianti ridge was still a growing antiform becoming a real “sill” separating the siena from the valdarno basins. there is a long sedimentary hiatus between the deposition of the montevarchi and bucine synthems and there are no elements to establish when the deformation ended. however, it is widely accepted that in the apennine area a generalised uplift activated at the end of the early pleistocene (ambrosetti et al., 1982; coltorti & pieruccini, 1997a; 1997b; calamita et al., 1999). the uplift is commonly responsible for the rapid incision of the river network (fig. 9e) interrupted by the deposition of the bucine synthem, during the late pleistocene in a landscape similar to the present-day one. 5. discussion and conclusions geological and geomorphological evidences together with facies analysis of the pliopleistocene sediments allow us to reconstruct the evolution of the chianti ridge and the westernmost part of the valdarno basin. the reconstruction also partially involves the nearby siena basin to the west and the apennine ridge to the east. we demonstrated that: a. the area was affected by an important planation surface 79 fig. 9 hypothesis of the dynamic evolution of the s. barbara basin. a: the beginning of the evolutive history, the spedalino and meleto subsynthems overlain by a major unconformity (u1) the deformed bedrock made by ligurian terrains, tuscan nappe and cervarola-falterona units; between the two subsynthems is inferred by a minor unconformity (early pliocene-late early pliocene, older than 3.5 ma); b: modelling of planation surface/unconformity (earlymiddle pliocene, 3.5÷3.1 ma); c: the montevarchi synthem lies unconformably (u2) on the previous sediments (3.1÷1.8? ma); d: the uplift of the chianti ridge has the effect of the formation of a new unconformity (u3) that cut the previous deposits (younger than 1.8 ma); e: the bucine synthem lies by unconformity (u3) on the previous sediments and it represents the last unit deposited during the late pleistocene. si: siena basin; ch: chianti ridge; va: valdarno basin; bu: bucine synthem; mo: montevarchi synthem; me: meleto subsynthem; sp: spedalino subsynthem; sb: sands; ag: clays; li: lignite banks; li: ligurian units; tu: tuscan nappe. 1: main unconformity; 2: minor unconformity. ipotesi dell’evoluzione dinamica del bacino della s. barbara. a: inizio della storia evolutiva, i subsintemi di spedalino e di meleto giacciono in discordanza (u1) sul substrato deformato fatto di unità liguri, falda toscana e unità cervarola-falterona; tra questi due subsintemi è ipotizzata una minore discordanza (pliocene inferiore-pliocene inferiore finale, più vecchio di 3.5 m; b: modellamento della superficie di spianamento/discordanza (pliocene inferiore – pliocene medio, 3.5÷3.1 ma); c: il sintema di montevarchi si depone in discordanza (u2) sui precedenti depositi (3.1÷1.8? ma); d: il sollevamento della dorsale del chianti causa la formazione di una nuova discordanza (u3) che taglia i depositi precedenti (più giovani di 1.8 ma); e: il sintema di bucine giace in discordanza sui precedenti sedimenti e rappresenta l’ultima unità depostasi durante il pleistocene superiore. si: bacino di siena; ch: dorsale del chianti; va: bacino del valdarno; bu: sintema di bucine; mo: sintema di montevarchi; me: subsintema di meleto; sp: subsintema di spedalino; sb: sabbie; ag: argille; li: banchi di lignite; li: unità liguri; tu: falda toscana. 1: discordanza principale; 2: discordanza minore. the growth of the chianti ... (early pliocene) (u1; fig. 9a). the deposition of the spedalino gravels (sp) is the result of the first subaereal erosion probably following deformational events. with the meleto subsynthem (me) the area became a wide flood plain whose limits are not well recognisable. all these events are older than 3.5 ma. b. a major antiform developed in correspondence with the chianti ridge after the deposition of the meleto subsynthem and before the deposition of the montevarchi synthem (fig. 9b). at the edge with the valdarno basin, which represented a large synform, a progressive unconformity (u2) separates the two sequences. a sedimentological signature of this tectonic event is missing except for the later occurrence of a generally coarser depositional environment. most probably the antiform was rapidly erased similar to what has been observed with seismic profiles in numerous sectors of the adriatic sea (ori et al.,1986; argnani & gamberi, 1995). these events occurred between 3.5. and 3.1.ma. c. deposition of the montevarchi synthem (mo; fig. 9c) the base of which possibly corresponds with the second cycle of the siena basin (sb) although the relationship between these two areas is unknown. the montevarchi synthem was deposited after 3.1 ma and slightly before the rena bianca sands, late pliocene in age. the relationship between the different sequences shows a progressive unconformity that reveals a differential movement between the ridge and the basin. d. a major unconformity (u3), in younger times, was modelled across the area finally separating the siena and valdarno basins. the re-exumation of the older rocks on top of the chianti ridge probably occurred during these events (fig. 9d). we suppose that it corresponds to the planation surface recognised by sestini (1981) at the summit of the chianti ridge, partly re-exuming the older one. e. the long erosive hiatus between the bucine and montevarchi synthems prevents us from establishing, if the ridge continued to rise during the early and middle pleistocene. however, most probably, differential movements ended during the early pleistocene and have been followed by a generalised uplift affecting both basins and ridges similar to what has been observed in the nearby areas (dramis, 1992; calamita et al., 1999). more recently, differential movements could also be connected with the activity of the normal faults delimiting the easternmost part of the valdarno basin (finetti et al., 2001). the valdarno, being filled with softer sediments and bordered by harder terrains, constituted a favourite site for a rapid erosion generating one of the most important fluvial systems of the apennines. the thickness of fluvial sediments of the montevarchi synthem that were removed is hard to evaluate. this long erosional phase cancelled the eventual connection with the surrounding lower valdarno and val di chiana basins. as evidenced above, the history of the chianti ridge is very complex with the main modelling pliocene phases occurring close to sea level. only since the earlymiddle pleistocene did the area gradually reach the present-day situation, mostly as a result of a combination of generalised uplift and differential erosion mostly activated by the deepening of the hydrographic network. the results of our investigations coupled with the recent thermochronological data led to an evolutionary scheme for the ridges and the basins of the northern apennines that is very different from that proposed in the past (elter et al.,1975; mazzanti & trevisan, 1978; alvarez, 1999). in that model the ridges rise progressively from w to e as the consequence of the eastward migration of the compressive front. however, our results shows that: 1. the chianti ridge, as the other ridges of the eastern sectors (calamita et al., 1999), are not anticlines but antiforms; 2, they were modelled after the emplacement of the ligurian units that moved along a major detachment; 3, there are no synsedimentary pliocene faults between the ridge and the basin but progressive unconformities as a result of deformations of the sedimentary cover; 4, there are no lacustrine deposits in these basins but they are mostly filled by meander and braided flood plain deposits, similar to what was recognised in the nearby east tiber valley (coltorti & pieruccini, 1997a; 1997b) and, in the barga basin to the north (landi et al., 2003; coltorti et al., submitted). there is also no evidence that suggests the existence of the main apennine divide with a ridge in a position similar to the present-day one up to the late pliocene and it is our conclusion that the upper valdarno could have represented the western part of the peri-adriatic basin. if this is confirmed, the eastward migration of the compressional movements and the creation of the present day apennine watershed was not gradual but very rapid in the geological time scale and occurred mostly during the pleistocene. references a.a.v.v. (1982) carta strutturale dell’appennino settentrionale e note illustrative. publ. n° 429 consiglio nazionale delle ricerche c.n.r. abbate e. (1983) schema stratigrafico della successione neoautoctona del valdarno superiore e del bacino di arezzo. in: abbate e. & sagri m. (eds.), “i depositi fluviolacustri del valdarno superiore”. ist. geol. paleont. univ. firenze, p. 1-6. abbate e., balestrieri m.l., bigazzi g., norelli p. & quercioli c. (1994) fission-track datings and recent rapid denudation in northern apennines, italy. mem. soc. geol. it., 48, 579-585. abbate e. & sagri m. (1981) olistostromes in the oligocene macigno formation (florence area). in: ricci lucchi f. (ed.) excursion guidebook of the 2° european regional meeting of the i.a.s., bologna, 164-185. albianelli a., bertini a., magi m., napoleone g., & sagri m. (1995) i l bacino plio-pleistocenico del valdarno superiore: eventi deposizionali, paleomagnetici e paleoclimatici. il quaternario, 8 (1), 11-18. albianelli a., azzaroli a., bertini a., ficcarelli g., napoleone g. & torre d. (1997) paleomagnetic and palynologic investigations in the upper valdarno basin (central italy): calibration of an early villafranchian fauna. riv. it. paleont. strat., 80 m. coltorti, s. ravani & f. verrazzani 103, 111-118. albianelli a., magi m., mazzini m. & napoleone g. (2002) the plio-pleistocene boundary in the northern apennine continental deposits as defined by faella magnetostratigraphic section in the upper valdarno. boll. soc. geol. it., vol. spec. 1 (2002), 473-479. alvarez w. (1999) drainage on evolving fold-thrust belts: a study of trasverse canyons in the apennines. basin research, 11, 267-284 ambrosetti p., carraro f., deiana g. & dramis f. (1982) i l sollevamento dell’ ital ia centrale tra i l pleistocene inferiore e ed il pleistocene medio. in “contributi conclusivi alla realizzazione della carta neotettonica d’italia”, pubbl. 513, p.f. geodinamica, cnr, 219-223. argnani a., barbacani g., bernini m., cimurri f., ghielmi m., papani g., rizzini f., rogledi s. & torelli l. (2004) gravity tectonics driver by quaternary uplift in the northern apennines: insights from the la spezia-reggio emilia geo-transect. quaternary international, 101-102 (2003), 13-26. argnani a. & gamberi f. (1995) stili strutturali al fronte della catena appenninica nell’adriatico centro-settentrionale. studi geol.camerti, v.s., 1996 (1), 1828. azzaroli a. (1977) the villafranchian stage in italy and the plio-pleistocene boundary. neogene – quaternary boundary proc., ii symp., bologna 1975, giorn. geol., 41 (2), 61-79. azzaroli a. (1984) on some vertebrate remains of middle pleistocene age from the upper valdarno and val di chiana, tuscany. paleont. it., 73, 104115. azzaroli a. & lazzeri l. (1977) i laghi del valdarno superiore. centro studi geologia appennino cnr, università di firenze, pubbl. 26, 4pp. balestrieri m.l, bernet m., brandon m.t., picotti v., reiners p. & zattin m. (2003) pliocene and pleistocene exhumation and uplift of two key areas of the northern apennines. quaternary international, 101-102, 67-73. barberi r., cavinato g.p., gliozzi e. & mazzini i. (1995) late pliocene-early pleistocene paleoenvironmental evolution of the rieti basin (central apennines). il quaternario, 8, 515-535 barchi m.r, minelli g. & pialli g. (1998) the crop 03: a synthesis of the results on deep structures of the northern apennines. mem. soc. geol. it., 52, 383-400. benvenuti m. (1993) stratigrafia e sedimentologia dei depositi fluvio-lacustri plio-pleistocenici dell’area nord occidentale del valdarno superiore (toscana). riv. it. paleont. strat., 98, 467-486. benvenuti m., dominici s. & rook l. (1995) inquadramento stratigrafico-deposizionale delle faune a mammiferi villafranchiane (unità faunistiche triversa e montopoli) del valdarno inferiore nella zona a sud dell’arno (toscana). il quaternario, 8, 457-464. bernini m., boccaletti m., moratti g., papani g., sani f., & torelli l. (1990) episodi compressivi neogenico-quaternari nell’area estensionale tirrenica nord-orientale. dati in mare e a terra. mem. soc. geol. it., 45, 577-589. bertini a. (1994) palynological investigations on upper neogene and lower pleistocene sections in central and northern italy. mem. soc. geol. it., 48, 431-443. bertini a. (2001) pliocene climatic cycles and altitudinal forest development from 2.7 ma in the northern apennines (italy): evidence from the pollen record of the stirone section (5.1 to 2.2 ma). geobios, 34, 253-265. bertini a. & roiron p. (1997) évolution de la végétation et du climat pendant le pliocène moyen, en italie centrale: apport de la palynologie et de la macroflore à l’étude du bassin du valdarno supérieur (coupe de santa barbara). c.r. acad. sci. paris, t. 324, serie iia, 763-771. bertini g., cameli g.m., costantini a., decandia f.a., di filippo m., dini i., elter f.m., lazzarotto a., liotta d., pandeli e., sandrelli f., & toro b. (1991) struttura geologica fra i monti di campiglia e rapolano terme (toscana meridionale): stato attuale delle conoscenze e problematiche. studi geol. camerti, vol. spec., 1, p. 155-178. billi p., magi m., & sagri m. (1991) pleistocene lacustrine fan delta deposits of the valdarno basin, italy. journ. sed. petrology, 61, 280-290. boccaletti m., bonini m., moratti g., & sani f. (1995) le fasi compressive neogenico-quaternarie nell’appennino settentrionale: relazioni con l’evoluzione dei bacini interni e con la tettonica del basamento. studi geologici camerti, vol. spec. 1995/1, 51-72. boccaletti m. & coli m. (1983) la tettonica della toscana: assetto ed evoluzione. mem. soc. geol. it., 25, 51-62. boccaletti m. & sani f. (1998) cover thrust reactivations related to internal basement involvement during neogene – quaternary evolution of the northern apennine. tectonics, 17, 112-130. boccaletti m., bonini m., moratti g., & sani f. (1999) compressive neogene-quaternary tectonics in the hinterland area of the northern apennines. j. petroleum geology, 22 (1), 37-60. boncio p., brozzetti f., ponziani f., barchi m., lavecchia g. & pialli g. (1998) seismicity and extensional tectonics in the northern umbria-marche apennines. mem. soc. geol. it., 52, 539-555. boncio p. & lavecchia g. (2000) a structural model for active extension in central italy. j. geodynamics, 29, 233-244. bonini m. (1999) basement-controlled neogene polyphase cover thrusting and basin development along the chianti mountains ridge (northern apennines, italy). geol. mag. 135, 133-152. borselli v., de giuli c., ficcarelli g. & mazzini m. (1980) casa frata: una località fossilifera nel villafranchiano superiore presso terranuova bracciolini (arezzo) nel valdarno superiore. boll. soc. paleont. it., 19, 254-258. bossio a., costantini a., foresi l. m., lazzarotto a., liotta d., mazzantii r., mazzei r., salvatorini g., & sandrelli f. (1995) studi preliminari sul sollevamento della toscana meridionale dopo il pliocene medio. studi geologici camerti, vol. spec. 1995/1, 87-91. bossio a., cerri r., costantini a., gandin a., lazzarotto 81the growth of the chianti ... a., magi m., mazzanti r., sagri m., salvatorini g. & sandrelli f. (1992) i bacini distensivi neogenici e quaternari della toscana. guida escursione 76° congr. soc. geol. it., firenze. calamita f., coltorti m., pieruccini p., pizzi a. (1999) evoluzione strutturale e morfogenesi plio-quaternaria dell’appennino umbro-marchigiano tra il preappennino umbro e la costa adriatica. boll. soc. geol. it., 118, 125-139. cande s.c. & kent d.v. (1995) revised calibration of the geomagnetic polarity time scale for the late cretaceous and cenozoic. j. geophys. res. 100(b4), 6093–6096. castellucci p., & cornaggia f. (1980) gli olistrostromi nel macigno dei monti del chianti: analisi stratigrafica strutturale. mem. soc. geol. it., 21, 171180. chiocci f.l. & normark w.r. (1992) effect of sea-level variation on upper-slope depositional processes offshore of tiber delta, tyrrhenian sea, italy. marine geology, 104, 109-122. coltorti m. the plio-pleistocene origin and evolution of the drainage in the apennines, italy. quat. international, submitted. coltorti m., & pieruccini p. (1997a) the southern east tiberian basin (spoleto, central italy): geology and stratigraphy of the plio-pleistocene sediments. il quaternario, 10 (2), 159-180. coltorti m., & pieruccini p. (1997b) middle-upper pliocene ‘compression’ and middle pleistocene ‘extension’ in the east-tiber basin: from ‘synform’ to ‘extensional’ basin in the tyrrhenian side of the northern apennines (central italy). il quaternario, 10 (2), 521-528. coltorti m. & pieruccini p. (2002) the late lower pliocene planation surface and mountain building of the apennines (italy). in “dramis f., farabollini p. & molin p. eds., large-scale vertical movements and related processes.”, studi geol.camerti, n.s., 1, 45-60. coltorti m. & pieruccini p. (2006) the last interglacial pedocomplexes in the lithoand morpho-stratigraphical framework of the central-northern apennines. quaternary international, 156-157, 118-132. coltorti m. pieruccini p. & rustioni m. the barga basin (tuscany): a record for the plio-pleistocene mountain building of the northern apennines, italy. quat. international, submitted. decandia f.a., lazzarotto a. & liotta d. (1993) la “serie ridotta” nel quadro della evoluzione geologica della toscana meridionale. mem. soc. geol. it., 49, 181-191. de giuli c. (1983) aspetti paleontologici della successione del valdarno superiore e del bacino di arezzo. in: i depositi fluvio-lacustri del valdarno superiore, istituto di geologia e palentologia di firenze, guida escurs., 19-23. doglioni c. (1991) a proposal of kinematic modelling for w-dipping subductions – possible applications to the tyrrhenian – apennines system. terra nova, 3, 423-434. dramis f. (1992) il ruolo dei sollevamenti ad ampio raggio nella genesi del rilievo appenninico. studi geol. camerti, "evoluzione geomorfologica e tettonica quaternaria dell'appennino centro-meridionale, vol. spec., 9-15. elter p., giglia g., tongiorgi m., & trevisan l. (1975) tensional and compressional areas in the recent (tortonian to present) evolution of the northern apennines. boll. geof. teor. appl., 17, p. 3-18. elter f.m. & sandrelli f. (1995) inquadramento strutturale dei monti del chianti. boll. soc. geol. it., 114(3), 537-547. eva c., giglia g., graziano f. & merlanti f. (1978) seismicity and their relation with surface structure in the north-western apennines. boll. geofis. teor. appl., 20, 263-277. fejfar o. (2001) the arvicolids from arondellitriversa: a new look. bollettino della societa paleontologica italiana, 40(2), pp. 185 193 ferrini g. e pandeli e. (1983) le associazioni di facies torbiditiche nel macigno dei monti del chianti. boll. soc. geol. it., 102, 223-240. finetti i.r., boccaletti m., bonini m., del ben a., geletti r., pipan m. & sani f. (2001) crustal section based on crop seismic data across the north tyrrhenian–northern apennines–adriatic sea. tectonophysics, 343(3-4), 135-163. ghinassi m. & magi m. (2004) variazioni climatiche, tettoniche e sedimentazione al passaggio pliocene medio-pliocene superiore nel bacino del valdarno superiore (appennino settentrionale). boll. soc. geol. it., 123, 301-310. ghinassi m., magi m., sagri m., & singer s. b. (2004) arid climate 2.5 ma in the plio-pleistocene valdarno basin (northern apennines, italy). palaeogeography, palaeoclimatology, palaeoecology, 207, 37-57. gliozzi e., abbazzi l., argenti p., azzaroli a., caloi l., capasso barbato l., di stefano g., esu d., ficcarelli g., girotti o., kotsakis t., masini f., mazza p., mezzabotta c., palombo m.r., petronio c., rook l., sala b., sardella r., zanalda e., torre d. (1997) biochronology of selected mammals, molluscs and ostracods from middle pliocene to the late pleistocene in italy. the state of art. rivista italiana di paleontologia stratigrafica, 103, 369-388, milano. grasso m. & butler r.w.h. (1991) tectonic controls on the deposition of the late tortonian sediments in the caltanisetta basin of the central sicily. mem. soc. geol. it., 47, 313-324. landi e., ravani s., sarti g. & sodini m. (2003) -the vil lafranchian deposits of the castelnuovo garfagnana and barga basins (lucca, tuscany, italy): facies analysis and paleoenvironmental reconstruction. atti soc. tosc. sci. nat. serie a, 108 (2002-2003), 81-93. lazzarotto l., & liotta d. (1991) structural features of the lignitiferous basin of santa barbara, upper valdarno area. boll. soc. geol. it., 110, 459-467. lecca l., carboni s., scarteddu r., sechi f., tilocca g., pisano s. (1986) schema stratigrafico della piattaforma continentale occidentale e meridionale della sardegna. mem. soc. geol. it., 36 lecca l., panizza v. & pisano s. (1998) the sedimentary framework of cagliari basin: a pliopleistocene underfed rift basin in the southern sardinia margin. il quaternario, 11(2), 301-318. 82 m. coltorti, s. ravani & f. verrazzani liotta d. (1996) analisi del settore centro – meridionale del bacino pliocenico di radicofani (toscana meridionale). boll. soc. geol. it., 115, 115-143. liotta d. & salvatorini g. f. (1994) evoluzione sedimentaria e tettonica della parte centro-meridionale del bacino pliocenico di radicofani. studi geol. camerti, vol. spec., 1, 65-77. locardi e. (1982) individuazione di strutture sismogenetiche dall’esame della evoluzione vulcano-tettonica dell’appennino e del tirreno. mem. soc. geol. it., 24, 569-596. magi m. & sagri m. (1996) aeolian sand sheets and terminal fans: sedimetonlogical evidences of arid climate conditions in the plio-pleistocene valdarno basin (northern apennines, italy). 17th regional african european meeting of sedimentology, i.a.s. sfax, abstracts 172-173. malinverno a. and ryan w.b.f. (1986) extension in the tyrrhenian sea and shortening in the apennines as a result of arc migration driven by sinking of the lithosphere.tectonics, 5,2, 227-245. mariani i.p. & prato r. (1988) i bacini neogenici costieri del margine tirrenico: approccio sismico e stratigrafico. mem. soc. geol. it., 41, 519-531. martini i.p., & sagri m. (1993) tectono sedimentary characteristics of late miocene-quaternary extensional basin of northern apennines, italy. earth sci. rev., 34, 197-233. mazzanti r. & trevisan l. (1978) evoluzione della rete idrografica nell’appennino centro – settentrionale. geogr. fis. din. quat., 1, 55-62. merla g. (1949) i leptobos reutim ital iani . paleontogr. it., 46, 41-155. merla g. (1969) macigno del chianti. in: formazioni geologiche, fascicolo ii, studi illustrativi della carta geologica d’italia, 65-77. merla g. & abbate e. (1967) note illustrative della carta geologica d’italia, f.114 “arezzo”. servizio geologico d’italia, 52. miall a.d. (1985) architectural-element analysis: a new method of facies analysis applied to fluvial deposits. earth sc. rev., 22, 261-308. miall a.d (1996) the geology of fluvial deposits: sedimentary facies, basin analysis and petroleum geology. springer, new york. napoleone g., albianelli a., azzaroli a. & mazzini m. (2003) dating the late villafranchian (pliocene) vertebrate collections of the upper valdarno (tuscany, italy) by the magnetochronologic framework of the basin fill. boll. soc. paleont. it., 42(3), 301-313. nardi r. (1961) geologia della zona tra la pania della croce, gallicano e castelnuovo (alpi apuane). boll. soc. geol. it., 80(2), 257-334. ori g.g., roveri m. & vannoni f. (1986) pliopleistocene sedimentation in the apenninic foredeep (central adriatic sea, italy). spec. publ. int. ass. sediment., 8, 183-198. patacca e., sartori r., & scandone p. (1990) tyrrhenian basin and apenninic arcs: kinematic relations since late tortonian times. mem. soc. geol. it., 45, 425-451. passerini p. (1964) il monte cetona. boll. soc. geol. it., 83, 219-338. pini a. (1999) tectonosomes and olistostromes in the argille scagliose of the northern apennines, italy. the geological society of america, spec. paper edited by g.a. pini, 70 pp. riforgiato f., mazzei r., salvatorini g., sandrelli f. (2005) chronostratigraphic revision of some pliocene basins in tuscany at the zanclean/ pliocene basins in tuscany at the zanclean/piacenzian boundary . bollettino della società geologica italiana, vol. spec. (3), 7 – 13. ricci lucchi f. (1986) the oligocene to recent foreland basins of the northern apennines. in: allen p.a., homewood p., (eds.), foreland basins. international association of sedimentologists, spec. publ., 8, 105-139. ruggieri g. (1970) note illustrative del foglio 108 (mercato saraceno). serv. geol. d'italia. sagri m. (1991) evoluzione stratigrafica e tettonica del bacino del valdarno superiore . memorie valdarnesi, serie 7, anno 157, 13-21. sagri m. & magi m. (1992) il bacino fluvio-lacustre del valdarno superiore (pliocene superiorepleistocene). in: guide all’escursione post-congresso, escursione b4, 76a riunione estiva: l’appennino settentrionale, società geologica italiana, firenze 24-26 settembre 1992. sestini a. (1936) stratigrafia dei terreni fluvio-lacustri del valdarno superiore. atti soc. tosc. sc. nat., 45, 37-41. sestini a. (1981) un’antica superficie d’erosione nei monti del chianti. riv. geogr. ital., 88, 214-220. tongiorgi e. & tongiorgi m. (1964) age of the miocene-pliocene limit in italy. nature, 201, 365367. trevisan l. (1952) sul complesso sedimentario del miocene superiore e del pliocene della val di cecina e sui movimenti tettonici tardivi in rapporto ai giacimenti di lignite e di salgemma. boll. soc. geol. it., 70, 65-78. veneri f. (1986) la colata gravitativa della val marecchia. in: e. centamore & g. deiana (eds.) "la geologia delle marche". studi geol. cam., vol. spec., 83-87. 83 ms. ricevuto il 24 agosto 2006 testo definitivo ricevuto il 10 febbraio 2007 ms. received: august 24, 2006 final text received: february 10, 2007 the growth of the chianti ... imp. santangelo iinntteerraazziioonnee ttrraa tteettttoonniiccaa rreecceennttee ee pprroocceessssii ggeeoommoorrffiiccii nniiccoolleettttaa ssaannttaannggeelloo dipartimento di scienze della terra – università degli studi di napoli “federico ii” riassunto l’obiettivo di questo lavoro è quello di individuare i principali indicatori geomorfologici di attività tettonica recente e di evidenziare le possibili interazioni tra tettonica e processi erosivo/deposizionali nei vari contesti geomorfici (fluviali, di versante, carsici e costieri). particolare attenzione è stata rivolta al problema della taratura degli indicatori ed alla definizione della loro sensibilità. da questa analisi è emerso che molti di essi presentano dei limiti e che la possibilità del loro ritrovamento è funzione del contesto geologico e geomorfologico in cui ci si trova. esistono contesti “più favorevoli” alla genesi ed alla conservazione degli indicatori (aree caratterizzate da tassi elevati di deformazione, con bassi tassi dei processi erosionali e caratterizzate da affioramenti di litologie più conservative) e contesti “meno favorevoli”. in ogni situazione la ricerca degli indicatori di attività tettonica recente dovrà essere rigorosa e calibrata in funzione dello scenario in cui verrà eseguita. abstract the interaction between active tectonics and geomorphic processes.this paper was addressed to point out the main geomorphic indicators of active tectonics and to clarify the possible interactions between tectonics and erosional/depositional processes in various geomorphic scenarios. for each group of processes (fluvial, slope, karst and coastal) the most common indicators have been selected trying also to discern the typology of the tectonic movement (uplift, faulting, tilting) that they can outline. the problem of the “calibration” and sensitivity of the various indicators was also faced. the analysis outlines that the use of many indicators is limited by several factors represented by the difficulty on finding precise chronological constraints, by their low degree of preservation and by the convergence between some landforms actively and passively controlled by structure. moreover, due to the variable erodibility of the outcropping rocks and to the variable rates of deformation with respect to the rates of geomorphic processes, the various geomorphic scenarios can be more or less favourable for the genesis and preservation of the indicators. the absence of geomorphic indicators will not necessarily outline the absence of active tectonics, but could represent the response to tectonics active with rates lower than the rates of the main geomorphic processes. for this reason, the research for the indicators will have to be detailed and calibrated in relation to the scenario in which it will be carried out. parole chiave: indicatori geomorfologici – tettonica recente – processi geomorfici. keywords: geomorphological indicators – active tectonic – geomorphic processes. il quaternario italian journal of quaternary sciences 1166(1), 2003, 27-34 iinnttrroodduuzziioonnee per affrontare un discorso sugli indicatori geomorfologici di attività tettonica recente è innanzitutto necessario chiarire cosa si deve intendere per “tettonica recente”(active tectonics o active faulting della letteratura inglese ed americana). il termine “recente” è infatti abbastanza ambiguo e necessita di una precisazione cronologica più accurata, ed il termine “tettonica” risulta abbastanza generico e non dà alcuna informazione sulle modalità e sul tipo di deformazione in oggetto. consultando la letteratura è possibile associare all’aggettivo “recente” una finestra temporale compresa tra l’attuale e 104 anni ed indicare con il termine più generico di “neotettonica”, tutti i movimenti e le deformazioni che ricadono in un intervallo più ampio (104 – 106 anni). una definizione cronologica così rigorosa però, può risultare sterile, in quanto una comprensione approfondita dell’evoluzione della deformazione nel tempo può richiedere una indagine su intervalli temporali più ampi. ciò accade, per esempio, quando le metodologie adottate, o le aree in studio, non hanno una sensibilità tale da consentire una risoluzione cronologica così dettagliata. in queste condizioni, anche l’approccio su una scala temporale più ampia (ultimi 200-300 ka per esempio), potrà fornire delle preziose informazioni sul comportamento tettonico recente dell’area in studio. per tale motivo, si può ritenere questa finestra temporale relativamente flessibile e si può stabilire di tararla ogni volta in funzione delle caratteristiche dell’area in studio e delle metodologie adottate. altra cosa importante da chiarire è il tipo di deformazione tettonica che si vuole ricercare è cioè moti verticali “in toto” della superficie terrestre, quali sollevamenti e subsidenze a carattere regionale, oppure fagliazioni e quindi dislocazioni verticali, oblique ed orizzontali o, ancora, basculamenti della superficie terrestre dovuti a piegamenti o a tilting localizzati. queste precisazioni sono necessarie per scegliere gli indicatori più significativi ed in particolare per chiarire quale sensibilità essi devono avere per assumere tale ruolo. 28 n. santangelo iinnddiiccaattoorrii ggeeoommoorrffoollooggiiccii facendo riferimento a quanto detto nel paragrafo precedente ed analizzando la letteratura esistente su questo argomento, è stata prodotta la tab. 1, nella quale i principali indicatori sono raggruppati in funzione dei processi geomorfici e delle diverse tipologie di deformazione. processi fluviali l’interazione tra movimenti tettonici e processi fluviali può essere ricondotta ad una generale variazione dei rapporti tra erosione e sedimentazione lungo un corso d’acqua in funzione della capacità erosiva, del tipo di trasporto, dei tassi e delle modalità del movimento (continuo o discontinuo). indicatori geomorfologici attività tettonica recenteprocessi interazioni erosivo tettonica/ deposizionali moti verticali “in toto” fagliazione basculamenti processi duplicazione di terrazzi episodi di ed anomalie nella loro variazione variazione dei incisione o distribuzione generale. morfologia rapporti tra erosione e aggradazione non anomala distribuzione letto (sensu sedimentazione lungo giustificati da sola aree in erosione ed in ouchi, 1985; il corso d’acqua in fluviali componente aggradazione shumm 1986) funzione di: capacità climatica anomalie profilo erosiva e tipo di terrazzi longitudinale trasporto, tassi e valli tronche (hanging modalità del valleys) sollevamentovalli a calice (wine-glass subsidenza (continuo valleys) /discontinuo) anomalie tracciato anomalie nella morfologia e nei gradienti delle conoidi alluvionali (sensu bull, 1977) dislocazione depositi fluviali dissezione e/o dislocazione fasce seppellimento fasce detritiche pedemontane detritiche scarpate (“nastri”) in pedemontane in roccia e/o detriti funzione dei rapporti di versante indice smf (bull & tra tassi di mcfadden (1977) sollevamentosubsidenza e velocità di sedimentazione. attivazione e/o riattivazione di processi franosi variazione contesto dislocazione deviazione microambientale. riempimenti asse di improvvisa dislocazione morfologie accrescimento formazione di doline carsici carsiche di stalagmiti da crollo sia in roccia anomalie di crescita (forti & che in coperture concrezioni potschpil, detritiche. 1984; 1985) formazione dislocazione depositi variazione dei lagune marini basculamenti rapporti tra erosione (sollevamento con dislocazione morfologie regionali o /sedimentazione e emersione barre costiere locali di quindi sommerse) anomalie altimetriche di terrazzi arretramento/progradaavanzamento e terrazzi marini (ois 5 e zione in funzione dei costieri arretramento successivi) rispetto alle tassi e delle modalità spiagge paleoquote eustatiche di sollevamentodissezione o subsidenza sommersione delta. tab.1 principali indicatori geomorfologici di attività tettonica recente main geomorphological indicators of active tectonics nel caso di moti verticali di carattere regionale e ad una scala temporale secolare, gli indicatori geomorfologici sono rappresentati da episodi di incisione (sollevamenti relativi) o di aggradazione (abbassamenti relativi) delle aree in movimento e da formazione di veri e propri terrazzi su tempi più lunghi (migliaia o decine di migliaia di anni). ovviamente, la ricerca di questi indicatori è facilitata nelle porzioni montane ed intermedie dei bacini idrografici mentre risulta più complessa nelle zone costiere, dove l’interazione con le oscillazioni eustatiche rende più difficile l’individuazione degli effetti indotti sui processi fluviali dalla sola componente tettonica. a tale riguardo merrits et al. (1994), in uno studio comparato dei terrazzi fluviali di tre bacini idrografici adiacenti, in un’area della california settentrionale soggetta ad uplift nel tardo quaternario e nell’olocene (ultimi 250 ka), hanno evidenziato come l’influenza dell’eustatismo sul terrazzamento sia intensa nella porzione costiera e di pianura alluvionale dei bacini in esame, mentre nelle zone montane il terrazzamento è causato quasi interamente dal sollevamento tettonico. la risposta di questi corsi d’acqua all’uplift di lungo termine è stata la formazione di terrazzi erosionali spaiati (unpaired strath terrace); la distribuzione asimmetrica delle superfici rispetto all’asse vallivo viene interpretata dagli autori come la risposta ad un processo di sollevamento continuo, mentre l’ampiezza di queste superfici e l’entità 29interazione tra tettonica recente e ... del dislivello esistente fra i vari ordini sono funzione della capacità erosiva del corso d’acqua e delle modalità del sollevamento (fig 1). per quanto riguarda invece gli indicatori geomorfologici di fagliazione in ambiente fluviale , la casistica è molto più ampia; tralasciando le evidenze di fagliazione di depositi alluvionali recenti (che costituiscono un indicatore in senso stratigrafico, geologico più che geomorfologico), gli indicatori più utilizzati sono rappresentati dalla duplicazione di uno stesso ordine di terrazzi fluviali, dall’anomala distribuzione di aree in aggradazione e/o in erosione, da anomalie nel profilo longitudinale (sensu burnett & schumm, 1983), da piccole scarpate rettilinee che dislocano superfici deposizionali tardoquaternarie-oloceniche e da susseguenze o gomiti fluviali impostate su depositi tardo-pleistocenici. anche le valli tronche (hanging valleys) e le valli a calice (wine-glass valleys) vengono comunemente elencate tra gli indicatori di dislocazioni verticali ma esistono dei casi di convergenza morfologica che pongono dei limiti al loro utilizzo (cfr. paragrafo successivo). lo studio delle conoidi alluvionali fornisce ulteriori utili indicatori (keller,1986) sia per l’individuazione di episodi di fagliazione recente (presenza di scarpate trasversali o brusche variazioni di pendenza nel gradiente longitudinale di apparati tardo pleistocenici–olocenici ) che per una quantificazione relativa dei tassi di movimento lungo il lineamento in questione. in quest’ultimo caso infatti la presenza di apparati sovrapposti (con deposizione concentrata nelle aree apicali) od incastrati (fig. 2) può indicare tassi di sollevamento differenziati (rispettivamente maggiori e minori) del fronte montuoso rispetto alla capacità di dissezione dei torrenti alimentatori delle conoidi (bull, 1977). ancora, un anomala distribuzione delle caratteristiche morfometriche (area, gradiente) di apparati di conoide coevi, disposti al piede di un fronte montuoso di origine tettonica, può indicare la presenza di settori caratterizzati da diversi tassi di sollevamento o la presenza di importanti lineamenti trasversali (hooke, 1972; rockwell et al.,1984). in altri casi le conoidi possono essere spostate orizzontalmente lungo faglie trascorrenti e quindi possono riuscire ad indicare direzione e verso del movimento oltre che i tassi di scorrimento, qualora sia possibile la determinazione della loro età. gli esempi più significativi a riguardo sono quelli identificati lungo la faglia di san andreas in california (keller et al., 1982). per quanto riguarda infine le variazioni indotte sui corsi d’acqua da movimenti plicativi localizzati, ouchi (1985) e schumm (1986) ritengono che l’aumento o la diminuzione di gradiente longitudinale di un corsa d’acqua prodotti da basculamenti della superficie associati al sollevamento di una anticlinale o alla subsidenza di una sinclinale, produrrebbero sul breve termine delle brusche variazioni della morfologia del letto fluviale. le varie possibilità, simulate in laboratorio, sono riportate in fig. 3 e sono funzione del tipo di trasporto prevalente (carico sospeso, braided etc). fig. 1 differenti morfologie trasversali di sezioni vallive con formazione di terrazzi erosionali spaiati in funzione di tassi di sollevamento differenti e di diversa capacità erosionale del corso d’acqua. gli schemi c) e d) si riferiscono ad un tasso di sollevamento due volte più alto di quello degli schemi a) e b). da merrits et al.,1994, modificato. model of unpaired strath terrace development along a meandering bedrock river for different uplift rates and river sizes. sketches c) and d) are for a rate two times grater than sketches a) and b). from merrits et al.,1994, modified. 30 processi di versante le interazioni più importanti tra eventi tettonici e processi di versante possono essere ricondotte ad episodi di dissezione e/o di seppellimento delle fasce detritiche pedemontane poste al piede di un fronte montuoso o di un versante impostato su di una faglia, in funzione dei rapporti tra tassi di sollevamentosubsidenza e tassi di sedimentazione. in tale contesto gli indicatori geomorfologici saranno relativi solo ad episodi di fagliazione e potranno darci informazioni relative alla tipologia del movimento (diretto, inverso o trascorrente) e/o sull’età relativa del movimento. oltre alle classiche evidenze stratigrafiche, rappresentate dalla fagliazione di detriti di versante recenti, gli indicatori morfologici più utilizzati in questo settore sono rappresentati da piccole scarpate di faglia ("nastri") in roccia o detriti, che interrompono la continuità del profilo longitudinale di un versante di faglia. e’ questo un esempio di indicatori che presentano però vari limiti. non sempre infatti la scarpata è il prodotto diretto di un movimento tettonico ma può essere legata ad erosione differenziale tra litologie più e meno conservative che vengono in contatto lungo la faglia (caso molto frequente in appennino ed anche nelle alpi, panizza et al., 1978; brancaccio et al., 1979; 1986; cinque et al.,1991; ascione & cinque, 1997; bartolini & peccerillo, 2002) o ad un costipamento differenziale nell’ambito dei detriti di versante. inoltre l’assenza di tale indicatori non implica necessariamente l’assenza di attività tettonica recente, in quanto la scarpata potrebbe non essere presente perché sepolta dai detriti, qualora i tassi di uplifit/subsidenza eguaglino quelli di sedimentazione della falda detritica, o perché cancellata dagli agenti esogeni qualora i processi di arretramento della scarpata stessa avvengano con tassi maggiori di quelli del sollevamento. a tale riguardo sono significativi i lavori di wallace (1977) , di mayer (1986) e di nash (1986) relativi alle variazioni morfologiche nel tempo di scarpate di faglia in funzione del tipo di processo prevalente (fig. 4). un’altra anomalia del profilo longitudinale di un versante di faglia che può indicare una ripresa dell’attività tettonica in tempi recenti è la presenza di un tratto basale caratterizzato da maggiore pendenza rispetto alla porzione sommitale (brancaccio et al., 1979; cinque et al., 1991; bartolini & peccerillo, 2002). in questi casi bisognerà porre particolare attenzione a casi di convergenza morfologica legati ad erosione selettiva. scartate le situazioni in cui lungo la faglia vengono a contatto litologie a forte contrasto morfoselettivo, profili longitudinali di versanti di faglia caratterizzati da bruschi aumenti di pendenza basali, potranno essere considerati ottimi indicatori di tettonica recente, soprattutto se impostati su litologie tenere. n. santangelo fig. 2 formazione di conoidi sovrapposte (a) o incastrate (b) ai piedi di un fronte montuoso in sollevamento in funzione di differenti tassi di uplift. in a i tassi di sollevamento sono maggiori che in b. da bull, 1977. formation of superimposed fans (a) or entrenched fans at the foot of an uplifting mountain front for different rates of uplift. the rate uplift of a) is major than b). from bull,1977. 31 suo piede e la lunghezza del versante in linea d’aria. questo indice riflette un bilancio ideale tra la tendenza dei processi di versante e dei processi fluviali a creare un andamento sinuoso, in pianta, del versante e la tendenza dei processi tettonici di sollevamento verticale a produrre un andamento rettilineo. bassi indici di sinuosità pertanto, saranno indicatori di versanti lungo i quali i tassi di sollevamento tettonico prevalgono su quelli dei processo erosivo-deposizionali. anche in questo caso sussistono possibilità di casi di convergenza morfologica, per esempio con versanti di linea di faglia per i quali il basso indice di sinuosità è legato soltanto ad una esumazione recente del piede del versante per morfoselezione e non ad un movimento recente lungo la faglia. discorso a parte meritano i casi di attivazione e/o riattivazione di processi franosi che spesso si verificano in aree caratterizzate da tettonica recente ed in particolare in concomitanza di grossi eventi sismici (vedi terremoti del friuli e dell’irpinia). tali fenomeni sono da considerarsi semplicemente degli “effetti” della tettonica recente ma non possono assumere il ruolo di indicatori a causa dei numerosi fattori di controllo passivo che condizionano la loro distribuzione. processi carsici in ambiente carsico gli indicatori più significativi di attività tettonica recente sono rappresentati dalle anomalie di crescita di concrezioni di grotta. la dislocazione diretta di morfologie carsiche epigee ed ipogee (paleosuperfici carsiche dislocate a gradinata, complessi carsici fagliati e sospesi rispetto agli attuali livelli di base; bellucci et al., 1983; santangelo & santo 1991; piccini, 1997) rappresenta infatti un buon indicatore di fagliazione sul lungo termine, ma sono abbastanza rare le segnalazioni di evidenze di questo interazione tra tettonica recente e ... fig. 3 risultati della simulazione in laboratorio della risposta di un corso d’acqua meandriforme a carico misto prevalente ad a) un inarcamento di tipo anticlinalico e b) ad una subsidenza legata ad una deformazione di tipo sinclinalico. l’ordine temporale è dall ’alto verso i l basso. da ouchi, 1985. adjustment of a mixed load meandering river to a) anticl inal uplift and b) synclinal s u b s i d e n c e across it. time sequence is expressed in the order from top to bottom. from ouchi,1985. fig. 4 variazioni morfologiche di una scarpata di faglia nel tempo in funzione dei processi di degradazione prevalenti. da wallace,1977. change in fault scarp morphology with time for different faultscarp degradation processes. un altro indicatore di attività tettonica recente lungo un versante di faglia o lungo un fronte montuoso, è rappresentato secondo bull e mc fadden (1977) dall’ indice di sinuosità del versante (indice smf), dato dal rapporto tra la lunghezza del versante misurata lungo il 32 tipo sul breve termine. le anomalie di crescita delle concrezioni di grotta (forti & postpischl, 1984:1985) invece costituiscono degli ottimi indicatori soprattutto in campo paleosismologico; lo studio di queste anomalie infatti, oltre a fornire informazioni sulla tipologia della deformazione (fagliazione o basculamenti), consente di accedere ad una registrazione di eventi sismici che va ben oltre l’arco temporale coperto dai dati storici, normalmente utilizzati in paleosismologia. a ciò si aggiunge un altro prezioso requisito che le concrezioni hanno rispetto ad altri indicatori e cioè la possibilità si essere facilmente datate con metodi radiometrici (serie u/th). processi costieri anche le interazioni tra tettonica e processi costieri sono riconducibili ad una variazione dei rapporti tra erosione e sedimentazione e quindi tra arretramento e progradazione della linea di costa in funzione dei tassi e delle modalità della deformazione tettonica. la situazione in questo caso è complicata anche dalle oscillazioni eustatiche del livello marino e dalle loro possibili interazioni con i movimenti tettonici. gli indicatori più utilizzati sono senz’altro rappresentati dalle anomalie altimetriche di terrazzi marini e/o di paleomorfologie costiere deposizionali ed erosionali (cordoni costieri, solchi, falesie), rispetto alle paleoquote eustatiche. l’analisi della distribuzione planimetrica di queste anomalie aiuta a comprendere la modalità e la tipologia del movimento tettonico. nella finestra temporale in cui abbiamo confinato la tettonica recente ricadono gli stage isotopici 2 e 1 a cui corrispondono paleoquote eustatiche negative; la possibilità di trovare in superficie indicatori di paleolivelli marini, implica quindi necessariamente la presenza di attività tettonica. le aree del nostro pianeta in cui sono conservate gradinate di terrazzi marini tardo pleistocenici ed olocenici sono generalmente quelle interessate da forti tassi di dislocazione (sollevamento) e deformazione (piegamento e fagliazione) legati direttamente ai movimenti delle placche litosferiche (subduzione e rifting) o ad attività vulcano tettonica. fanno eccezione le aree del nord europa e del nord america in cui le gradinate di terrazzi tardo pleistoceniche ed oloceniche riflettono la risposta isostatica della crosta e del mantello alla deglaciazione tardo pleistocenica. per tutte le altre aree non interessate da tassi di movimento tali da consentire la deformazione e l’emersione di linee di riva del tardo pleistocene superiore e dell’olocene, tra le quali rientra la maggior parte delle aree costiere italiane (fatta eccezione per la calabria, la sicilia e le aree vulcaniche come ischia ed i campi flegrei per esempio), l’attività tettonica recente potrà essere evidenziata almeno dalla anomala distribuzione altimetrica delle linee di riva dell’ultimo interglaciale (cosentino & gliozzi, 1988; romano , 1992). lliimmiittii ddeeggllii iinnddiiccaattoorrii quanto finora detto consente di constatare che i vari indicatori elencati presentano, di frequente, dei limiti di applicabilità o di validità, riconducibili alle seguenti casistiche. casi di convergenza morfologica sono molto frequenti e legati al classico problema del controllo attivo o passivo della struttura sulle forme del rilievo: è il caso delle fault scarps e delle fault-line scarps, delle anomalie di tracciato della rete idrografica (antecedenze e sovrimposizioni, offsets dovuti a susseguenza etc.) e per tale discussione si rimanda alla letteratura (thornbury 1954, 243-275 pp.; bartolini & peccerillo, 2002). altre situazioni classiche di convergenza morfologica si realizzano in casi di controllo climatico e/o antropico: esempio tipico è quello dei fenomeni di erosione e di aggradazione recenti lungo gli alvei fluviali legati ad oscillazioni climatiche secolari (piccola età glaciale per es. ) che limitano effettivamente l’utilizzo di questi elementi come indicatori di attività tettonica recente. cronologia la maggior parte degli indicatori citati spesso fornisce indicazioni cronologiche soltanto relative e pertanto non consente di ricavare informazioni quantitative sui tassi della deformazione; pochi sono gli indicatori che risultano associati a depositi su cui sia possibile effettuare datazioni assolute (tefra e paleosuoli intercalati nelle successioni continentali o associati a terrazzi, depositi marini, concrezioni di grotta). scarso grado di conservazione alcuni indicatori (p.es piccole scarpate di faglia) possono essere cancellati dai processi geomorfici. la possibilità di conservazione di un indicatore dipende da vari fattori quali litologia, entità e tassi dei processi geomorfici, contesto climatico, entità della deformazione. non sempre l’assenza di indicatori sarà significativa di assenza di tettonica recente ma potrà indicare, per esempio, bassi tassi di deformazione rispetto ai ritmi dei processi erosionali predominanti . distribuzione localizzata ( scarsa rappresentatività) alcuni indicatori, presi singolarmente non sono significativi e sono invece necessarie delle associazioni di forme per rendere “visibile” la deformazione tettonica. e’ il caso per esempio degli offsets laterali su faglie trascorrenti: una semplice deflessione di drenaggio non sarà un indicatore “sufficiente” di movimenti recenti lungo una faglia trascorrente ma, associato ad altri indicatori (dossi lineari, scarpate, sag ponds vedi fig. 5), risulterà un indicatore di ottima qualità. ccoonncclluussiioonnii prima di concludere si può fare una breve panoramica sulla situazione della ricerca italiana su questo tema. i vari progetti (“morfotettonica”, “geomorfologia strutturale “, “catene e pianure”) portati a termine tra gli anni ’80 e ‘90 ed i vari congressi e convegni ( fiastra, camerino, parma, siena) organizzati sul tema, hanno delineato il quadro morfostrutturale del territorio italiano con un buon grado di approfondimento a scala regionale, per quanto riguarda l’evoluzione di medio e lungo termine (104 – 106 anni). meno approfondito risulta invece il quadro relativo all’evoluzione della tettonica recente, n. santangelo sismici e quindi del contesto geodinamico in cui si trova l’area di studio (vedi fig. 6). a questi fattori si possono aggiungere l’entità ed i tassi dei processi erosionali e l’erodibilità delle litologie interessate. i contesti più favorevoli sono quindi rappresentati da aree interessate da grossi tassi di deformazione, bassi tassi di erosione e aggradazione ed impostate su litologie più resistenti. (situazione opposta per le meno favorevoli). in contesti sfavorevoli gli indicatori significativi sono a volte indiretti (per esempio distribuzione dei depocentri deposizionali in una conca intermontana, anomalie della forma e dei gradienti di conoidi alluvionali etc.) e devono essere ricercati con maggiore scrupolosità ed attenzione. si può quindi concludere affermando che la ricerca degli indicatori di attività tettonica recente deve essere rigorosa e calibrata in funzione dello scenario in cui viene eseguita. l’approccio metodologico deve essere necessariamente multidisciplinare e quindi l’analisi geomorfologica deve integrarsi con quella paleosismologica, geologico-strutturale, geocronologica al fine di produrre un quadro dettagliato dell’evoluzione delle deformazioni nel tempo e nello spazio. in particolare essa deve contribuire a definire i tassi di movimento su breve e lungo termine, a fornire informazione sui tassi dei processi erosionali che interagiscono con l’attività tettonica, a proporre dei modelli quantitativi di evoluzione dei singoli processi in rapporto a diversi tassi di deformazione (nash, 1986; cinque et al.,1991;1995), a migliorare i dati di cronologia assoluta e relativa. 33interazione tra tettonica recente e ... fig. 5 associazioni di forme indicatrici di attività recente lungo una faglia trascorrente. da keller,1986. assemblage of landforms associated with active strike-slip faulting. from keller,1986. fig. 6 diversa evidenza geomorfologica delle faglie attive in funzione del tempo di ritorno e della magnitudo degli eventi sismici. da slemmons and depolo, 1986. geomorphological features of active faulting related to recurrence interval and magnitude of earthquakes. from slemmons and depolo, 1986. anche perché il contesto geologico e geomorfologico della nostra penisola fa sì che gli effetti al suolo delle deformazioni siano poco evidenti. si può infatti affermare che esistono contesti più o meno favorevoli alla produzione ed alla conservazione degli indicatori di tettonica recente. slemmons & depolo (1986) per esempio, sottolineano come la possibilità di avere buone evidenze morfologiche di fagliazione superficiale in corrispondenza di faglie attive, sia funzione della magnitudo e del tempo di ritorno degli eventi i possibili sviluppi futuri dell’analisi geomorfologica in questo campo potranno fornire importanti contributi nella individuazione delle aree caratterizzate da tettonica recente e nella selezione dei siti in cui l’approfondimento delle ricerche potrà essere produttivo. ciò soprattutto in relazione a problematiche relative alla quantificazione dei tassi di deformazione sul breve e sul lungo termine, alla determinazione del tempo di ritorno dei terremoti ed alla zonazione (macro e micro) della pericolosità sismica . bbiibblliiooggrraaffiiaa ascione a. & cinque a. (1997) le scarpate su faglia dell’appennino merdionale: genesi, età e significato tettonico – il quat., 10(2), 285-293. bartolini c. & peccerillo a. (2002) i fattori geologici delle forme del rilievo. lezioni di geomorfologia strutturale pp. 216, pitagora ed. bellucci f., brancaccio l., celico p. cinque a., giulivo i., santo a. (1983) evoluzione geomorfologica, carsismo ed idrogeologia della grotta del caliendo (campania). le grotte d'italia 4, xi 1983. brancaccio l., cinque a., sgrosso i. (1979) l’analisi dei versanti di faglia come strumento per la ricostruzione di eventi neotettonici. mem. soc. geol. it. , 19. brancaccio l., cinque a., sgrosso i. (1986) elementi morfostrutturali ereditati nel paesaggio dell’appennino centro-meridionale – boll. soc. geol. it.,35, 869-874. bull w.b. (1977) the alluvial fan environment progr. phys. geogr., 1, 222-270. bull w.b. & mac fadden l.d. (1977) tectonic geomorphology north and south of the garlock fault, california – in geomorphology in arid regions, d.o. doehring ed., publications in geomorphology, state university of new york at binghamton , 115138. burnett a.w. & schumm s. a. (1983) active tectonics and river response in louisiana and mississippi. science, 222, 49-50. cinque a., cammisa a. & monaco r. (1991) fault scarps with straight profile in southern apennines. simulation modelling and neotectonic deductions. mem.soc.geol.it., 47,575-585. cinque a., de pippo t. & romano p. (1995) coastal slope terracing and relative sea-level changes: deduction based on computer simulations earth surface processes and landforms, 20, 87-103. cosentino d. & gliozzi e. (1988) considerazioni sulla velocità di sollevamento dei depositi marini eutirreniani dell ’ i tal ia meridionale e della sici l ia. mem.soc.geol.it., 41, 653-665. forti p. & postpischl d. (1984) seismotectonic and paleoseismic analyses using karst sediments. marine geology, 55, 145-161. forti p. & postpischl d. (1985) relazioni tra terremoti e deviazioni degli assi di accrescimento delle stalagmiti. le grotte d’italia, 4(xii), 287-303. hooke r.l. (1972) geomorphic evidence for latewisconsin and holocene tectonic deformation, death valley, california – geol.soc.am.bull,83, 2073-2098. keller e.a. (1986) investigations of active tectonics. use of surficial earth processes – in “ active tectonics” – studies in geophysics, 136-147, national academy press, washington. lajoie k. r. (1986) coastal tectonics. in active tectonics” – studies in geophysics, 136-147, national academy press, washington mayer l. (1986) tectonic geomorphology of escarpments and mountain fronts. in active tectonics” – studies in geophysics, 136-147, national academy press, washington merrits d.j., vincent k.r., wohl e.e. (1994) long river profiles, tectonism and eustasy: a guide to interpreting fluvial terraces. journ. geophys. res., 99, no. b7, 14031-14050. nash d. b. (1986) morphological dating and modelling degradation of fault scarps. in active tecto-nics” – studies in geophysics, 136-147, national academy press, washington ouchi s. (1985) response of alluvial rivers to slow active tectonic movement. geol.soc.am.bull.,96, 504-515. ota y, hulll a.g. & berryman k.h (1991) coseismic uplift of holocene marine terraces in the pakarae river area, eastern north island, new zealand – quat. res., 35, 331-346. panizza m., carton a., castaldini d., mantovani f. & spina s. (1978) esempi di morfoneotettonica nelle dolomiti occidentali e nell’appenni-no modenese. geogr. fis. din. quat.,1, 28-54. piccini l.(1997) evolution of karst caves in the alpi apuane (italy): relationships with the morphotectonic history. geogr.fis din.quat., suppl iii, 4, 2131. rockwell t.k., keller e.a., clark m. n., & johnson d.l. (1984) chronology and rates of faulting of ventura river terraces, california. geol. soc. am. bull.,95, 1466-1474. romano p. (1992) la distribuzione dei depositi marini pleistocenici lungo le coste della campania. stato delle conoscenze e prospettive di ricerca. studi geol. camerti., vol.spec. 1992/1, 265-269. santangelo n. & santo a. (1991) endokarstic evolution of carbonatic massifs in campania (southern italy). quad. geogr., univ. padova, 13. schumm s.a. (1986) alluvial river response to active tectonics in “ active tectonics” – studies in geophysics, 80-94, national academy press, washington. slemmons d.b. & depolo c.m. (1986) evaluation of active faulting and associated hazards in “active tectonics” – studies in geophysics, 45-62, national academy press, washington. thornbury w.d. (1954) principles of geomorphology. john wiley & sons ed., 618 pp. wallace r.e. (1977) profiles and ages of young fault scarps, north central nevada. geol.soc.am. bull.,88,1267-1281. 34 ms. ricevuto il 7 gennaio 2003 testo definitivo ricevuto il 13 maggio 2003 ms. received: january 7, 2003 final text received: may 13, 2003 n. santangelo impaginato castaldini aa mmeetthhooddoollooggyy ffoorr mmeeddiiuumm--ssccaallee sseeiissmmiicc ssuusscceeppttiibbiilliittyy mmaappss:: aann eexxaammppllee ffrroomm tthhee mmooddeennaa aappeennnniinneess ((nnoorrtthheerrnn iittaallyy)) ddoorriiaannoo ccaassttaallddiinnii11,, mmaassssiimmoo bbaarrbbiieerrii11,, ggiiuusseeppppee bbeetttteellllii11,, mmaarrccoo ccaappiittaannii11 && mmaarriioo ppaanniizzzzaa11 1dipartimento di scienze della terra, università degli studi di modena e reggio emilia abstract this paper describes a methodology for the implementation of medium-scale (1:50,000 scale) seismic susceptibility maps for assessing seismic hazard in territorial planning. it illustrates the research carried out in the modena and reggio emilia provinces with an example in the modena mid-apennines (area between zocca and rocca malatina). the research, supported by bibliographical investigations on quaternary active faults and on earthquake-induced surface effects, was organised according to the following studies: 1) study of the geological characteristics. elaboration of “geological maps”. 2) study of the litho-technical characteristics for the identification of the areas which may show homogeneous litho-technical behaviour in the occurrence of earthquakes. elaboration of “litho-technical maps” and of “simplified litho-technical maps” 3) study of geomorphological characteristics for the determination of geomorphological situations which may give local responses by causing relative amplification of seismic waves and/or earthquake-induced instability. elaboration of “geomorphological maps” and of “simplified geomorphological maps”; 4) study of seismic susceptibility characteristics for the identification of the areas prone to seismic amplification and/or earthquake-induced instability on the basis of previous data. elaboration of “maps of seismic susceptibility”. in these maps, the litho-technical features potentially causing amplification are shown with zones classified from 1 to 5 according to the increase of amplification (amplification from low to high); the morphological features causing amplifications (scarps higher than 20 m, narrow and long ridges) are shown with linear symbols. the features causing earthquake-induced instability are shown with zones indicated with letters from a to d according to the following classes of instability: a) stable areas and intermediate stability areas; b) potentially unstable areas with possible problems regarding the bearing capacity of soils; c) potentially unstable areas prone to mass movements; d) unstable areas prone to mass movements. the quaternary faults are also shown in the map. therefore, in the maps of seismic susceptibility the classes of susceptibility can be shown as zones with an alphanumeric code defined through the combination of numbers, from 1 to 5, and letters, from a to d (or with different areal symbols or different corresponding colours). the collected information was stored by means of geographic information systems (gis). the procedures for the implementation of the “maps of seismic susceptibility” were obtained by means of gis operations starting from the geological map, geomorphological map and the data base of the inventories of quaternary active faults and earthquake-induced surface effects. these maps give a sufficiently detailed picture of seismic hazard and susceptibility in the study area and can be easily consulted and understood by technicians from administration boards. the research herein described is qualitative and not quantitative and therefore, considering also the scale adopted, it can be considered as a grade 1 zonation (cf. tc4, 1999). riassunto una metodologia per la realizzazione di carte della pericolosità sismica a scala media: un esempio dall’appenino modenese (italia settentrionale). questa nota descrive una metodologia per l’elaborazione di carte, a media scala (1:50.000), per la valutazione della pericolosità sismica nell’ambito della pianificazione territoriale. essa illustra le ricerche eseguite nelle province di modena e reggio emilia con un esempio nel settore del medio appennino modenese (area tra zocca e rocca malatina). la ricerca, supportata da indagini bibliografiche sulle faglie quaternarie e sugli effetti superficiali sismoindotti, si è svolta secondo i seguenti studi: 1) studio delle caratteristiche geologiche. elaborazione di “carte geologiche”; 2) studio delle caratteristiche litotecniche per l’identificazione delle aree a comportamento litotecnico omogeneo in occasione di eventi sismici. elaborazione di “carte litotecniche” e “carte litotecniche semplificate”; 3) studio delle caratteristiche geomorfologiche per l'individuazione delle situazioni geomorfologiche che possono dare locali risposte causando amplificazione relativa delle onde sismiche e/o fenomeni di instabilità da terremoto. elaborazione di “carte geomorfologiche” e “carte geomorfologiche semplificate”. 4) studio delle caratteristiche di suscettibilità sismica per l’identificazione delle aree predisposte all’amplificazione sismica e/o a fenomeni di instabilità da terremoto sulla base dei dati precedentemente elaborati. elaborazione di “carte della suscettibilità sismica”. in queste carte, le aree predisposte all’amplificazione sismica sono classificate da 1 a 5 secondo un ordine crescente dell'amplificazione (da bassa ad alta); gli elementi morfologici che possono causare amplificazione (scarpate maggiori di 20 m, dorsali strette ed allungate) sono indicati con simboli lineari. le zone potenzialmente esposte a fenomeni di instabilità da terremoto sono indicate secondo le seguenti classi di instabilità: a) aree stabili o a stabilità intermedia; b) aree potenzialmente instabili con possibili problemi riguardanti la capacità portante del terreno; c) aree potenzialmente instabili esposte a movimenti di massa; d) aree instabili esposte a movimenti di massa. nelle carte vengono anche indicate le faglie quaternarie. pertanto nelle “carte della suscettibilità sismica” le classi di suscettibilità possono essere indicate con un codice alfa-numerico derivato dalla combinazione di numeri, da 1 a 5, e di lettere, da a a d, (o con diversi simboli areali oppure con diversi colori ad esse corrispondenti). i dati raccolti sono stati inseriti in una banca dati gis. l’elaborazione delle “carte della suscettibilità sismica” è stata realizzata attraverso operazioni gis partendo dalle carte geologiche, dalle carte geomorfologiche e dai data base delle faglie quaternarie e degli effetti superficiali sismoindotti. tali carte offrono un quadro sufficientemente dettagliato della pericolosità sismica e della suscettibilità dell’area di studio e sono facilmente consultabili e comprensibili da parte dei tecnici delle amministrazioni pubbliche. le ricerche descritte sono di tipo qualitativo e non quantitativo, pertanto, anche in considerazione della scala adottata, possono essere considerate come studi di zonazione di grado 1 (cfr. tc4, 1999). key words: geology, geomorphology, seismic hazard, seismic susceptibility, modena and reggio emilia provinces, northern italy. parole chiave: geologia, geomorfologia, pericolosità sismica, suscettibilità sismica, province di modena e reggio emilia, italia settentrionale. il quaternario italian journal of quaternary sciences 1155(2), 2002, 229-249 230 d. castaldini et al. 11.. iinnttrroodduuccttiioonn it is common knowledge that a correct methodological approach for the study of seismic hazard in a certain area should first provide for regional-scale investigations and, subsequently, local, specific studies. the product of investigations at a regional scale consists of a series of maps capable to describe the general seismic hazard of the area investigated. afterwards detailed investigations at a 1:10,000 scale (microzonation) or larger should be carried out in the areas subject to urban planning. in 1999 the administrations of the provinces of modena and reggio emilia stipulated a convention with the local university aiming at defining, in a period of two years, the knowledge concerning the assessment of seismic hazard and seismic susceptibility in their territory, since sufficiently detailed studies on this important topic were not available. this research was carried out considering that the institutional aims of the provincial administration boards in the field of territorial planning are between the national-regional level (the levels of law promulgation) and the municipal level (the level of local application of national and regional laws and the directions from the provinces). therefore the provinces are called to give to the municipalities useful directions for local territorial planning, but they cannot produce a real seismic microzonation because of either the vastness of their territories and the fact that the real authority for local territorial planning is given to the municipalities. therefore, the aim of the research was the acquisition of a sufficiently detailed picture of seismic hazard and seismic susceptibility in the provinces of modena and reggio emilia in order to identify the areas which could show problems due to seismic amplification and/or stability in dynamic conditions. these areas will be of particular concern for the administration boards at a municipal level and detailed investigations will be properly directed for assessing seismic hazard in territorial planning (seismic microzonation). this paper, after a regional outline on geologicalstructural, neotectonic, and seismotectonic characteristics and on earthquake-induced surface effects, describes the geological and geomorphological studies carried out for the implementation of medium-scale (1:50,000) seismic susceptibility maps in the modena and reggio emilia provinces and, in particular, it illustrates an example of these studies in the modena mid-apennines (area between zocca and rocca malatina). with the term seismic susceptibility the seismic hazard induced by the physico-geographical situations is meant (such as lithological, geomorphological situations, etc. of the area considered) (cf. panizza 1991 and 1996). in other words, the “seismic susceptibility maps” illustrated here are maps of the areas prone to seismic amplification and/or earthquake-induced instability. the modena and reggio emilia provinces are located in northern italy in the emilia-romagna region (fig. 1), the total extension of their territory being about 5,000 km2. the southern sector of their territory belongs fig. 1 geological sketch of the northern apennines (after gasperi et al., 1986) and location of the modena and reggio emilia provinces and the example area (zocca rocca malatina area) (thick lines). inquadramento geologico dell’appennino settentrionale (da gasperi et al., 1986) e ubicazione delle province di modena e reggio emilia e dell’area di zocca rocca malatina (linee in grassetto). to the northern apennines whereas the northern sector belongs to the po plain. the example area is located in the mid-apennines of the modena province between the hamlets of zocca and rocca malatina. this area was chosen because of its geological and geomorphological characteristics which are very common in the modena and reggio emilia mid-apennines. moreover, since 1994 this territory has been the epicentral area of several earthquakes (magnitude 1.5 to 2.5) recorded by the local seismic network (zucchi, 1995, 1996, 1997, 2000 and 2001) and it is close to the epicentral areas of the two strongest earthquakes which affected the modena and reggio emilia apennines in the past years. the first earthquake occurred in the night of december 31st 1995, with a 3.3 magnitude and intensity v of the mercalli-cancani-sieberg (mcs) scale; the second quake occurred on 7th july 1999 with a 4.6 magnitude and intensity vi mcs. 22.. aa sshhoorrtt rreevviieeww ooff ssttuuddyy mmeetthhooddoolloo-ggiieess ffoorr sseeiissmmiicc ssuusscceeppttiibbiilliittyy iinn iittaallyy in recent years the italian “national group for the defence against earthquakes” (gndt) has carried out a project for assessing seismic hazard in italy to be used as a basis for the revision of the seismic zonation at a national level. the final results of this project, which have regarded both the geological and seismological aspects, have been described by slejko et al. (1998) and galadini et al. (2000). in particular, galadini et al. (2000) collected the scientific articles relative to the investigations carried out by the gndt on the topic of seismic hazard in the 1996-99 period. however, since the main goal of this paper is the illustration of a methodology for the implementation of seismic susceptibility maps for territorial planning, it is opportune to review the methodologies concerning this field which have been proposed in italy in the last 20 years that is after the destructive earthquake (main shock 6.8 magnitude and intensity x mcs scale) which occurred on november 23rd, 1980 and struck a vast area in southern italy. nevertheless, considering the vast literature on this topic, it does not claim to be exhaustive. basically, there are two approaches finalised to the implementation of seismic hazard maps. the first is the “qualitative” approach by which the zones prone to amplification and/or instability in dynamic conditions are mapped. the best advantages of this approach consists in the possibility of application to large areas and a rapid zonation, although the accuracy is not high. the “quantitative” approach focuses on the seismic behaviour of a small area and makes use of data from field and laboratory tests which are generally used for calculating the “factors of safety”. the advantage of this approach is the high accuracy obtained, whereas the disadvantage consists in the long times required for zonation in rather large areas. some methods are based on the combination of the two approaches, by making use of the quantitative approach for the analysis in sample sites and, subsequently, extending the data to wider areas. siro & bigi (1983) illustrated the seismic microzonation investigations carried out in 39 inhabited centres of campania and basilicata struck by the november 231a methodology for medium scale ... 23rd, 1980 earthquake. these investigations were directed towards the implementation of geological-technical maps, seismic microzonation maps and maps of areal distribution of damage. methods for mapping geological and geomorphological elements associated with earthquake hazard conditions have been proposed by blumetti et al. (1987), bisci et al. (1990) and bisci & dramis (1992) for the marche region. the cartographic elements shown in these papers are particularly directed to territorial planning and can be adopted at different scales (from small to large scales) according to their purpose. in garfagnana (tuscany), d’amato avanzi et al. (1993) used a method which requires detailed geological and geomorphological surveys in order to draw up a map on which active and dormant landslides can be shown as well as areas potentially exposed to mass movements in case of earthquake because of their morphological and lithological features. a part from qualitative works, several quantitative studies have been carried out (e.g., among the most recent: pergalani, 1996; crespellani et al. 1996 and 1998; frassineti et al., 1997; pergalani et al., 1998, 1999, 2000 and 2002; luzi et al., 2000; regione toscana, 2000; marcellini & maugeri, 2001a and 2001b). in particular, in pergalani et al. (1998), the investigations aimed at the elaboration of instability maps, in static and dynamic conditions, in the apennine sector of lombardy. the main result of this study — carried out through the collection of geological-geomorphological data, gis-data elaboration, univaried and multivaried analysis on point data, identification of the hazardous areas by means of statistical methods, sensitivity analysis — are several maps (at a 1:10,000 scale) which can be a reliable tool in the field of territorial planning. the susceptibility of slopes to failure during earthquakes was calculated in terms of critical horizontal acceleration, on a subregional scale for a sector of the tuscan apennines by luzi et al. (2000). according to the working scale (1:10,000) and the availability and accuracy of the input data, the infinite slope analysis resulted in being the most appropriate method. a geological, geomorphological and hydrogeological study of the area was carried out and the geotechnical parameters were collected from local administrations. all the data were stored in a gis, used as a tool to build the spatial and attribute data base and prepare the input data layers for stability analyses. the final results can be useful to land use planners or can be used to give priorities to engineering projects. pergalani et al. (2000) published a volume devoted to the fast seismic microzonation of 782 inhabited centres struck by the 1997-1998 seismic sequence which occurred in the umbria and marche regions. in this paper, the local geological, geomorphological, hydrogeological and seismostratigraphic conditions capable of causing amplification of the seismic input, with respect to geological reference condit ions (bedrock), and/or permanent displacements (landslides, liquefaction, settlements and strains) have been considered. the maps elaborated at the 1:5,000 scale (geological-structural map, geomorphological map, lithotechnical map, map of the areas susceptible of local dynamic amplification or instability) were therefore correlated with previously analysed sample situations by means of 232 models in which a seismic movement resulting from historical and statistical analyses of regional seismic hazard was imposed. also marcellini & maugeri (2001a and 2001b) published special issues devoted to the study of some areas struck by the 1997-1998 umbria-marche seismic sequence. the issues illustrate microzonation methods both in the light of scientific aspects and criteria of practical application. these methods have geological maps, geomorphological maps and lithotechnical characterisation of the bedrock units as basic documents. qualitative-quantitative studies have been carried out in small areas of the tuscan-emilia apennines by castaldini et al. (1997, 1998a, 1998b). the method of these researches was based on multidisciplinary studies in order to better emphasise the complexity of the relationships between all the parameters affecting slope stability in static and dynamic conditions. a significant aspect of these studies was the attempt to improve the exclusively descriptive aspects of research on the relationship between earthquakes and induced surface effects, and to introduce a methodological approach by which this interaction can be quantified. one of the limits to the method proposed is that some factors were not utilised in the numerical definition of the stability conditions: the introduction of these factors might in fact modify the zonation of the maps of relative proneness to instability in non-seismic and seismic conditions. in the framework of the studies on seismic hazard mapping for administrative purposes, worthy of note is the work by peruzza et al. (2001) which describes an ongoing project, in the friuli-venezia giulia region in ne italy, in which, in the first phase of this project the soil conditions were considered, for defining attenuation d. castaldini et al. fig. 2 map of the seismogenetic zones of italy (after meletti et al., 2000) the grey area corresponds to the modena and reggio emilia provinces. carta delle zone sismogenetiche d’italia (da meletti et al., 2000). l’area in grigio indica le province di modena e reggio emilia. 233 relationships, on the basis of the lithological characteristics (prevailing rock type class). the local soil conditions, roughly summarized by considering a reference soil for each municipality of the region, are introduced into probabilistic seismic hazard estimates; the subsequent improvement is checked by comparing these new results and the maximum observed intensities in each municipality to investigate if the major differences between probabilistic estimates and actually observed data can be explained by local site effects and/or by the geometry of the seismogenetic zones used in the computation. from the review carried out, although short, it results that the methodologies aiming at the elaboration a methodology for medium scale ... fig. 3 schematic map of quaternary active faults in the modena and reggio emilia provinces. carta schematica delle faglie quaternarie delle province di modena e reggio emilia. 234 of cartographic documents (at various scales) on the seismic hazard of a certain territory have to take in account soil conditions and, therefore, have as basic documents, geological, geomorphological and lithotecnical maps. 33.. ggeenneerraall oouuttlliinnee ooff tthhee mmooddeennaa aanndd rreeggggiioo eemmiilliiaa pprroovviinncceess 33..11.. ggeeoollooggiiccaall--ssttrruuccttuurraall cchhaarraacctteerriissttiiccss a general geological sketch of the reggio emilia and modena provinces is shown in fig. 1. from a geological standpoint, the whole study area belongs to the northern apennines that are a fold-and-thrust belt built up mainly during the tertiary. during this period the convergence between the european and the adriatic plates caused, at first, the consumption of the interposed tethyan oceanic crust and, then, the collision between the two plates which led to the formation of this mountain chain. the main units forming the reggio emilia and modena apennines belt are: i) tuscan units, made up of tertiary flysches, continuously outcropping along the chain’s axis; ii) ligurian units made up of deep sea sediments including jurassic ophiolites followed by thick sequences of cretaceous to eocene calcareous or terrigenous turbidites; iii) the mainly terrigenous epiligurian sequences of the middle eocene to late messinian unconformably overlying the previously deformed ligurian units; iv) the plio-quaternary marine terrigenous deposits unconformably overlying the ligurian units and the epi-ligurian sequence and dipping under the alluvial deposits of the po plain (pieri & groppi, 1981). from the structural viewpoint the study area can be subdivided into three parts, from south to north (bettelli et al., 1994; 1996a; 1996b). the structural setting of the southern sector (high mountain sector) is characterised by important extensional fault systems generally nw-se trending. the central sector (midmountainous and hilly areas) shows a more complex structural style, given by a network of faults generally nw-se and ne-sw trending (strike-slip and normal faults were recognised southward, while compressive structures seem to prevail northward). in the northern sector (po plain) compressive geological structures (thrust systems), buried under the quaternary continental sediments of the po plain were recognised: the emilia folds and the ferrara folds. 33..22 nneeootteeccttoonniicc cchhaarraacctteerriissttiiccss the neotectonics characteristics of the study area are represented in bartolini et al. (1982) and cnr (1983). within the framework of this research, an inventory of quaternary active faults was set up with the compilation of a “map of quaternary active faults” and of fault data sheets. the “map of quaternary active faults” (fig. 3) contains the various faults which have been numbered, classified as “active” or “held to be active” (according to the definitions by panizza & castaldini, 1987) and subdivided into “outcropping” or “buried”. the data sheets for each fault, or group of faults, contain information on their characteristics (see castaldini et al., 2000). on the whole, in the modena and reggio emilia provinces 40 faults, or fault systems, were inventoried and mapped; 15 were classified as “active” and 25 as “held to be active”. the main elements are nw-se and wnw-ese oriented, according to the apennine chain trend, whereas the other prevalent trend is sw-ne and ssw-nne. in the mountain area faults “held to be active” show only geomorphological evidence of tectonic activity. the “active” faults are located along the apennine margin; in this area, many faults and folds affect the marine quaternary sediments. in the po plain sector the buried faults are classified as “held to be active” on the basis of data concerning the subsurface deposits, hydrogeological anomalies and evolution of the paleodrainage system. 33..33.. sseeiissmmootteeccttoonniicc cchhaarraacctteerriissttiiccss the information on earthquakes occurring from the year 1000 to 2000 in the modena and reggio emilia provinces and surrounding areas can be found in rercnr (1980), postpischl (1985), boschi et al. (1995), camassi & stucchi (1996), gruppo di lavoro cpti (1999) and boschi et al. (2000). as for recent seismic activity, the data can be taken from zucchi (1995, 1996, 1997, 2000, 2001): these papers contain data recorded by the local seismic network which is connected to the italian seismic network of the national institute of geophysics and volcanology (ingv). the publication making up the national reference for seismogenetic zonation is that by meletti et al. (2000). from this paper it results that the modena and reggio emilia provinces fall within the area subject to the passive sinking of the adriatic lithosphere under the chain system of the northern apennines. in particular, the study area is longitudinally subdivided into three belts parallel to the main structural trend of the northern apennines (nw-se) (fig. 2). the outermost belt (belonging to seismogenic zone no. 39) corresponds to the ferrara folds. these tectonic structures, buried under the po plain quaternary sediments, gave rise to a number of earthquakes, sometimes with damage and loss of lives both in historic times (years 1346, 1570 and 1832) and in the recent past (1996). the correggio earthquake of 15 october 1996, which had a 4.8 magnitude and a depth of 12 km (di giovanbattista & tyupkin, 1999; borghini et al., 2000), could be associated with the correggio fault (fault no. 41 in fig. 3). also the intermediate belt (zones nos. 30 and 35) is characterised by prevalently compressive structures. it partly corresponds to the emilia folds which form another thrust system buried under the quaternary sediments of the po plain. some other compressive structures crop out in the hill-foot sector. the earthquakes are mostly concentrated in a narrow zone which coincides with the plain-hill boundary: among the most intense events, the earthquakes of 1438 (viii mcs), 1501 (viiiix mcs), 1547 (viii mcs), 1818 (vii-viii mcs) and 1971 (vii-viii mcs) should be mentioned. the innermost belt (zones nos. 29 and 34) is located along the highest sector of the chain and is characterised mainly by extensional faults. some fault-plane solutions show that also the present seismic activity is extensional (frepoli & amato, 1997, 2000). this seismogenetic belt corresponds to the lowest seismicity portion d. castaldini et al. 235a methodology for medium scale ... fig. 4 earthquake-induced landslides (i.q. = 3) in the modena and reggio emilia provinces. legend: f) first time effect; i) intensity (mcs); m) magnitude; h) depth of focus (km); i.q.) information quality index; d) distance epicentre/effect; i.t.) interval time between earthquake and induced effect (cont. = contemporary). frane sismoindotte (i.q. = 3) nelle province di modena e reggio emilia. legenda: f) primo innesco; i) intensità (mcs); m) magnitudo; h) profondità ipocentrale (km); i.q.) indice di qualità dell'informazione; d) distanza epicentro/effetto; i.t.) intervallo temporale (giorni) terremoto/frana sismoindotta (cont. = contemporaneo). of the study area. the belt affected by higher-magnitude earthquakes in this sector of the northern apennines corresponds to the garfagnana and lunigiana areas located on the tyrrhenian side (zone no. 28). it is characterised by very evident extensional features. in the past this area was affected by higher-magnitude quakes; the most destructive events occurred in 1837 and 1920, both reaching an intensity of ix-x mcs in the epicentre area, and caused landslides also in the modena and reggio emilia apennines. as for the territory of the modena and reggio emilia provinces, the maximum intensity observed for the seismic events from the year 1000 to 1992 ranges from < v to vii-viii mcs (cf. camassi et al., 2000), with an expected intensity of vi-vii mcs in a return time of 475 years (cf. slejko et al., 1998). 33..44.. eeaarrtthhqquuaakkee--iinndduucceedd ssuurrffaaccee eeffffeeccttss within the framework of the research an inventory of earthquake-induced surface effects in the modena and reggio emilia provinces was prepared. it was based of the compilation of maps of earthquake-induced surface effects and of easy-to-consult surface effect data sheets (see castaldini et al. 2000). earthquake-induced surface effects have been isolated by consulting historical catalogues and archives, public authorities’ offices, research agencies, research projects and scientific reviews. as regards scientific reviews, several authors investigated the geomorphological effects caused by earthquakes in the study area: pellegrini & tosatti, (1982); zecchi (1987); mazzini (1994 and 1995); romeo & delfino (1997); casali & castaldini (1998); castaldini et al. (1998b); genevois et al. (2000) and bertolini & pellegrini (2001). in this research, the identification of earthquakeinduced surface effects was carried out according to the method proposed by genevois et al. (2000). according to mazzini (1995), as a discriminating tool, an information quality index (i.q.) was defined for the evaluation of the correspondence between earthquakes and induced surface effects. in the cases of a good correspondence, an i.q. = 3 has been attributed; in the cases of a fair correspondence an i.q. = 2 and in the case of any correlation an i.q. = 1. this research led to the collection of several surface effects occurring in spatial-temporal relationship with seismic events. nevertheless, only 12 well documented landslides can be reliably attributed to seismic events (i.q.= 3) (fig. 4). to some others surface effects, possibly due to seismic events (landslides, mud vulcanoes’ activity, fissures, ground deformation), an i.q. = 2 or 1 has been attributed. from the seismotectonic standpoint, earthquake-induced landslides (i.q.= 3) are nearly all (11 out of 12) located in the seismogenetic zones nos. 29 and 34 (cf. fig. 2) which correspond to the lowest seismicity portion of the study area. the triggering of landslides was due to seismic events occurring in the surrounding seismogenetic zones characterised by higher seismicity. in particular, seven landslides (nos. 3 to 9 in fig. 4) were triggered by the strong (x mcs and 6.5 magnitude) earthquake which struck garfagnana and lunigiana (seismogenetic zone no. 28 in fig. 2) on 7 september 1920. all the landslides were triggered by earthquakes with intensity ranging from ivv to x mcs degrees (3.3 to 6.5 magnitude) with epicentres some 15 to 30 km away. as regards the type of earthquake-induced landslides, they are mainly complex or slide-type movements. the rock types involved are essentially flysch, clay, clay shale and debris. most of these movements are reactivations of dormant landslides. the fact that earthquakes with <4 magnitude could trigger landslides even at distances of tens of km may seem strange in the light of more or less recent wellknown studies on earthquake-triggered landslides (e.g. keefer, 1984; bommer & rodriguez, 2002). nevertheless, as already pointed out by other authors (e.g. mazzini, 1995; genevois et al., 2000), this fact should not to be considered as anomalous, since a minimum triggerring threshold cannot be defined in an absolute sense. in fact, it is well known that slope stability is a function of many variables that are not less important than local magnitude. investigations aiming to assess the role of precipitation in triggering earthquake-induced landslides are now in progress (see castaldini et al., 2001). 44.. ssttuuddyy mmeetthhooddoollooggyy iinn mmooddeennaa aanndd rreeggggiioo eemmiilliiaa pprroovviinncceess the attempt to analyse and quantify the most important parameters which influence and condition the local effects, or site effects, requires complex studies which cannot be carried out over a vast, geologically complex and geomorphological varied area as the study area, mainly because of economic and time reasons. moreover, as previously stated, the principal institutional task of the provinces, in the matter of territorial planning, is to provide directions to the municipalities, which are the administrative bodies devoted to design the land use planning at a detailed scale (prg: municipal general regulation plane, psc: municipal structural plane; poc: municipal operative plane). for these reasons, the medium-scale investigations here proposed correspond to qualitative and not quantitative studies. considering the scale of this study, the use of essentially bibliographic data and the qualitative approach given to this research, the methodology here described may be classified as “a general zonation methodology” or, even better, a “grade 1 zonation” in the sense of tc4 (1999). this section illustrates the medium scale studies carried out in the modena and reggio emilia provinces with the elaboration of several maps (1:50,000 scale), according to the general scheme of fig. 5. in particular, this part is limited to a summarised illustration of the studies carried out in an apennine sector with the example of the zocca-rocca malatina area. the case-study is located in the mid-apennines of the modena province on the right-hand side of the r. panaro between the hamlets of zocca, to the south, and rocca malatina, to the north (figs. 6 to 10). the western and southern zones correspond to the slopes facing the r. panaro (which is located at about 200 m a.s.l.) and torrent missano (a right tributary of the r. panaro). the zone between zocca, samone and rocca malatina (central and eastern sector) is a sort of plateau with mild landforms. this sector attains altitudes slightly excee236 d. castaldini et al. ding 800 m a.s.l.: rocca malatina rises at about 530 m and zocca at 750 m. several hamlets are also found in this sector of the modena apennines (gainazzo, montecorone, missano and montealbano). the collected data were organised in order to be retrieved in a geographic information system (gis). the procedures for the implementation of the “maps of seismic susceptibility” were obtained by means of gis operations starting from the geological map, geomorphological map and the data base of the inventories of quaternary active faults and earthquake-induced surface effects. 44..11.. ssttuuddyy ooff tthhee ggeeoollooggiiccaall cchhaarraacctteerriissttiiccss the geological characteristics of the apennine sector where the example area is located are illustrated in regione emilia-romagna (2002) and have been briefly outlined in 3.1. in the zocca-rocca malatina area (fig. 6) two groups of very different types of rocks crop out: one belongs to the ligurian allochthonous sequences and the other to the unconformably overlying epiligurian sequence. the ligurian sequences, which crop out on the slopes facing the r. panaro and t. missano, can be subdivided into two parts: a lower one called “pre-flysch formations” (cretaceous) and an upper part called tresinaro valley sequence (upper cretaceous to paleocene-lower eocene?). the “pre-flysch formations” are represented by three dismembered shaly rock-units: i) scabiazza sandstones; ii) cassio varicoloured shales; iii) palombini shales. the tresinaro valley sequence is represented by an helminthoid flysch unit belonging to the monte cassio flysch and the overlying viano shales. the former is entirely made up of calcareous turbidites, the latter of varicoloured shales. in this area numerous landslides and slope deposits are also present. the epi-ligurian sequence constitutes the upper part of the example area relief and lies on the above described ligurian rocks owing to a marked angular unconformity. in the area depicted in fig. 6 this sequence is mainly represented by two different rock units (the 237a methodology for medium scale ... fig. 5 scheme of medium-scale studies (1:50,000 scale). schema degli studi a media scala (scala 1:50.000) pantano and cigarello formations) belonging to the bismantova group. the pantano (upper burdigalian?lower langhian) formation is made up of fine to very fine-grained arenites in medium to very thick tabular beds or by cross-bedded, fine to coarse-grained biocalcarenites and arenites. the cigarello formation (lower langhian-serravallian) lies on the pantano formation and consists of light grey, massive silty-sandy marls. the bismantova group is separated from the underlying older epi-ligurian units by a regional unconformity. the latter are mainly represented by scattered outcrops of clayey and marly rocks belonging to the contignaco, 238 d. castaldini et al. fig. 6 geological map of the zocca-rocca malatina area. the black zones correspond to the main hamlets. carta geologica dell’area di zocca e rocca malatina. le zone in nero indicano i principali centri abitati. antognola, ranzano and monte piano formations. colluvial deposits, a few metres thick, locally cover the epi-ligurian sequence. from a macrostructural viewpoint, the area is affected by important fault systems with vertical and horizontal displacements; the faults are n-s to sswnne oriented. 44..22.. ssttuuddyy ooff tthhee lliitthhoo--tteecchhnniiccaall cchhaarraacctteerriissttiiccss the different rock units cropping out in the modena and reggio emilia provinces have been described and assembled on a litho-technical basis, taking into account the parameters concerning composition, texture, degree of cementation, type of stratification and state of joints. in a first phase, a legend for the litho-technical units was compiled in respect to the rock types present in the study area starting from the geological map (see fig. 5); eleven litho-technical units, which are described below, were thus defined. ul1) flysch and competent multilayer units. they are multilayered units made of high-competence strata alternating with low-competence strata. even if they might display either ductile or brittle deformation patterns, the original strata are preserved and visible with the competent ones often prevailing on pelitic or marly layers. rocks belonging to this unit can be considered as rock masses showing good to very good strength characteristics. ul2) arenaceous flysch units. they correspond to the tuscan tertiary flysch formations which are mainly made up of layers of turbiditic sandstones alternating with fissile beds of marly pelites. the ratio between high competence levels and low competence levels is usually higher than 1. these rocks generally show from good to very good strength characteristics and good stability of the slopes. ul3) mainly arenaceous or arenitic units. this set groups all the units characterised by a prevalently arenitic, quartz-feldspar or calcarenitic composition. their cementation degree is variable but their competence is always high, and they generally show good strength attitude. ul4) heterogeneous units. the formations showing a lithologically heterogeneous composition are grouped in this unit. they are mainly made up of silty sandy marls and marly clays with pervasive slickensidelike scaly surfaces. they form rock masses of generally fair to poor strength depending on the degree of weathering. ul5) evaporite units. this rock type is found only in the reggio emilia apennines (triassic evaporites cropping out in the upper secchia valley and messinian evaporites cropping out along the apennine margin). these rocks generally show fair to poor strength characteristics owing to the solubility of some evaporite minerals. ul6) mainly pelitic-marly units. these units correspond to the rocks with a prevalently marly composition. they differ from the formations of litho-technical unit no. 4 because they show a globular fracturing with lower heterogeneity. for this reason they also show better strength characteristics when they are fresh, though this feature can locally lead to collapses due to weathering. ul7) ophiolites. ophiolitic rock masses are incorporated within the ligurian formations (they are therefore generally included within unit no. 9). only the ophiolite outcrops, representable at a 1:50,000 scale, are mapped. they show fair to good strength characteristics depending on mineral composition and degree of weathering. ul8) mainly argillaceous units. the lithostratigraphic units with a prevalent clayey-marly composition are grouped under this definition. they correspond mostly to the so called “argille azzurre” (blue clays) cropping out along the apennine margin. in a fresh state these rocks shows good strength characteristics, but they are deeply affected by water content changes. in the weathered state these rocks show poor to very poor strength characteristics. ul9) argillaceous units with block-in-matrix fabric. this litho-technical unit assembles all the lithostratigraphic units showing a mostly clayey composition, which also enclose rock blocks. they may be described as “chaotic units”. this unit comprehends most of the formations named in the not so recent literature as: argille scagliose, alloctono indifferenziato, complesso caotico, etc. the rocks of this unit display good geotechnical characteristics when not weathered; nevertheless, their argillaceous composition favours weathering processes up to considerable thicknesses with water percolation followed by cycles of plasticisation and desiccation. these processes make these soils extremely prone to displacements. ul10) surface deposits. superficial deposits of various origin (alluvial, eluvial, colluvial, glacial, slope, etc.) are grouped in this unit. they are heterogeneous materials with characteristics which may vary from very soft soils (lacustrine deposits) to loose grain deposits (e.g., slope deposits). these soils are distinguished on the basis of particle-size distribution which ranges from boulders to gravel (ul10a) and from sand to clay (ul10b). ul11) landslides. deposits and accumulation of materials genetically ascribed to slope movements are assembled in this group. among the above mentioned litho-technical units, only the following ones crop out in the study area: a) flysch and competent multilayer units (ul1); b) mainly arenaceous or arenitic units (ul3); c) heterogeneous units (ul4); d) mainly pelitic-marly units (ul6); d) argillaceous units with block-in-matrix fabric (ul9); e) surface deposit units distinguished on the base of their texture (ul10); f) landslides (ul11). anyhow, a “lithotechnical map” is not shown for the example area since it would be practically identical to the “simplified litho-technical map”, which will be discussed further on (fig. 7). it is known that buildings with similar structural features but built on different rocks or soils, even if located at a short distance from each other, react differently to earthquakes. this phenomenon is due to the so called local effects that can be referred to two different groups of causes: i) seismic amplification; ii) seismic instability. these phenomena are well described and analysed in literature (see for example: medvedev, 1965; borcherdt, 1970; siro & bigi, 1983; siro, 1985; phillips & aki, 1986; géli et al., 1988; margottini et al., 1992; ambraseys et al., 1996; pergalani, 1996; crespellani et al., 1996 and 1998; state of california, 239a methodology for medium scale ... 1997; lanzo, 1999; madiai, 1999; tc4, 1999; pergalani et al., 1998, 1999 and 2000; luzi et al., 2000; regione toscana, 2000; marcellini & maugeri, 2001a and 2001b; paolucci, 2002). local seismic amplification broadly consists in a local increase of the seismic waves amplitude relative to a reference site. this effect of wave amplitude amplification can be caused either by stiffness contrast between the bedrock and the superficial deposits or by difference in rigidity between the rocks in the investigated area and the rocks in the reference site. moreover, some particular morphological conditions can also locally focalise seismic energy giving rise to a seismic wave amplification effect. for example, among many relevant remarks in his very recent study, paolucci (2002) states that in the presence of marked ground roughness the factor of amplification of seismic waves typically varies between 1.5 and 2. in detailed studies of seismic microzonation (e.g.: pergalani, 1996), the effect of seismic amplification was studied assuming as reference site a particular 240 d. castaldini et al. fig. 7 – “simplified litho-technical map” of the zocca-rocca malatina area. the black zones correspond to the main hamlets. the legend is referred to the modena and reggio emilia apennines. “carta litotecnica semplificata " dell’area di zocca e rocca malatina. le zone in nero indicano i principali centri abitati. la legenda si riferisce all'area dell'appennino modenese e reggiano. location closer to the study area which might have an outcropping bedrock and almost subplanar morphology. in consequence of this detailed approach, the litho-technical unit forming the bedrock of the reference site can change depending on the geological nature of the study area. on the contrary, in this research, according to the studies aim, a conservative approach was adopted. referring to the classical work by medvedev (1965) a hypothetical reference site with a flat morphology and a 241a methodology for medium scale ... fig. 8 “geomorphological map” of the zocca-rocca malatina area. the black zones correspond to the main hamlets. “carta geomorfologica” dell’area di zocca e rocca malatina. le zone in nero indicano i principali centri abitati. granite bedrock was chosen (to which a 0 value of potential seismic amplif ication was attr ibuted). medvedev (1965) stated that an increasing seismic intensity may occur in areas where rocks softer than granite (reference rock) crop out. starting from this assumption, the seismic amplification may be qualitatively mapped considering the fact that it is generally more intense with the decrease of certain physical characteristics of the bedrocks and superficial deposits (especially stiffness and density). compared to granite, the simplified litho-technical units previously defined (see section 4.2 and fig. 7) can be ranked by considering the strength characteristics as qualitative measure of their stiffness. consequently, areas with different bedrock stiffness can be ranked, for their propension to local seismic amplification.since all rocks and soils cropping out in the modena and reggio emilia provinces are characterised (from a qualitative viewpoint) by values of stiffness lower than those pertaining to the granite, it results that all the territory of the study area may be potentially subject to relative amplification effects. since some of the previously defined litho-technical units show very similar stiffness characteristics, with respect to granite (considering also the work scale), they were grouped together. practically, in a second phase a legend for a “simplified litho-technical map” was elaborated reducing from eleven to five the litho-technical units (see fig. 7). in detail, the ul1, ul2 and ul3 litho-technical units were grouped together in the simplified litho-technical unit n. 1 ( sl1, rocky units) as they generally show from good to very good strength characteristics (depending on their stiffness). the ul4, ul5, ul6, ul7 and ul 8 litho-technical units were grouped together in the mixed units (sl2) as they show generally lower stiffness then the above mentioned units of sl1. the argillaceous units with block-in-matrix fabric (ul9), that often show a thick superficial weathered cover subject to rapid change in water content was considered less stiff than units of sl2 and it was defined as sl 3. finally the superficial deposits (ul10) and the landslide deposits (ul11), which show the poorest strength characteristics relative to the reference rock and also relative to the other ones, were classified as simplified litho-technical units sl4 and sl5, respectively. the “simplified litho-technical map” of the example area is shown in fig. 7. the example area may be subdivided into two separate sectors: i) a western and southern sector (corresponding to the slopes facing the r. panaro and t. missano); ii) a central and eastern sector (area between zocca, samone and rocca malatina). the first sector is essentially characterised by the presence of argillaceous units with block-in-matrix fabric (sl3) and landslides (sl5). on the bottom of the r. panaro and at the boundary with the eastern sector, surface deposits with texture from boulders to gravel (sl 4a) crop out. in the central and eastern sector the rocky units (sl1) made up of flysch and competent multilayer units (ul 1) and mainly arenitic units (ul 3) extensively crop out. locally, mixed units (sl2) (represented by heterogeneous units, ul 4, and mainly pelitic-marly units, ul 6), surface deposits with sandy-silty texture (sl 4b) and small superficial landslides (sl5) crop out. 44..33.. ssttuuddyy ooff tthhee ggeeoommoorrpphhoollooggiiccaall cchhaarraacctteerriissttiiccss the aim of this section is the identification of the geomorphological setting of the study area. the genesis, degree of activity of geomorphic processes, related landforms and deposits (with morphometric characteristics) must be distinguished in a preliminary phase. in the example area, the landforms and deposits identified may be mainly classified according to the following systems or groups of morphogenetic factors and processes (fig. 8): landforms and deposits due to running water; slope landforms and deposits due to gravity; structural landforms; anthropogenetic landforms, karsttype landforms. the bedrock is not shown since it is already represented in the “simplified litho-technical map” (fig. 7). also from the geomorphological viewpoint, the study area may be subdivided into two separate sectors, since the relief forms have been strictly conditioned by the characteristics of the outcropping rocky units: i) a western and southern sector ; ii) a central and eastern sector. in the first sector (slopes facing r. panaro and t. missano) the most relevant morphogenetic processes consist of active or dormant earth flows and rotationaltranslational slides which affect the shaly rocks. the various landslide bodies are bounded by several gullies which further contribute to slope instability owing to their accentuated erosion. the central and eastern sector (area between zocca, samone and rocca malatina), where arenaceous and arenaceous-pelitic formations crop out, only small zones seem to be affected by active degradational processes. this sector is higher in altitude (from about 500 to 800 m) than the western and southern sector (from about 500 to 200 m): on the whole this area is a sort of plateau with mild landforms. in the area, narrow v-shaped valleys and wide flat-floored valleys (partially filled by prevalently colluvial deposits) are found; although the wide flat-floored valleys are not shown by a specific symbol, the colluvial deposits make them easily identifiable in fig.8. karst type concavities are also present. the connection of this sector with the slopes facing the r. panaro and t. missano is made evident by the presence of scarps and long and narrow ridges. from studies recently carried out in the apennine sectors (pergalani et al., 1998 and 2000; luzi et al., 2000) it results that considerable amplifications of seismic waves take place in correspondence of detrital covers overlying a hard bedrock thicker than 10 m and that particularly narrow and elongated ridges and scarps higher than 20 m might cause a considerable focalisation of seismic waves with a consequent increase of seismic intensity. moreover, in the presence of loose deposits showing poor geotechnical characteristics (deposits with texture from silt to clay), serious settlements or even loss of the soils’ bearing capacity may occur, irrespective of their thickness and therefore of the effect of seismic amplification. other situations of potential seismic instability are linked to both active and dormant landslides. another possible hazard element linked to earthquakes is given by the presence of neotectonic faults: the resulting damage is due not so much to high dynamic stress but rather to possible differential displacements which may occur along these structural discontinuities. 242 d. castaldini et al. 243a methodology for medium scale ... fig. 9 – “simplified geomorphological map” of the zocca-rocca malatina area. the black zones correspond to the main hamlets. the legend is referred to the modena and reggio emilia apennines. “carta lgeomorfologica semplificata ” dell’area di zocca e rocca malatina. le zone in nero indicano i principali centri abitati. la legenda si riferisce all'area dell'appennino modenese e reggiano. therefore, in a second phase, a legend for the “simplified geomorphological maps” was properly elaborated in respect to the landforms and deposits present in the modena and reggio emilia apennines (see fig. 9). thus, landforms and deposits were distinguished to identify geomorphological situations which may give local responses to seismic acceleration and/or earthquake-induced instability. in this legend, the genesis of landforms and deposits was omitted (since it is not relevant for seismic susceptibility) whereas importance was given to the degree of activity, to morphometric characteristics (height, thickness, texture) and to topographical position (on valley bottom or flat areas, on slope). for example, the deposits were grouped on the basis of their thickness (from 1 m to 10 m, higher than 10 m). they were further distinguished on the basis of their particle-size characteristics (from boulders to gravel and from sand to clay) and their location (on slopes, valley floors or flat areas). a part from their activity (which is an important characteristic from the stability standpoint), scarps were distinguished according to their height (higher or lower than 20 m) which is a discriminating parameter for seismic amplification. furthermore, slope movements, in particular earthquake-induced landslides (resulting from the data base of earthquake-induced surface-effects inventory), and quaternary faults were considered. the quaternary faults, active or held to be active, are derived from the data base of the quaternary active fault inventory. nevertheless, i t should be specif ied that in the “simplified geomorphological maps” the quaternary faults are shown only in the stretches corresponding to faults represented in the geological maps. the “simplified geomorphological map” relative to the example area is shown in fig. 9. in this map, the landslides and the surface deposits located on the slopes facing the r. panaro and t. missano stand out. in the connection belt to the central and eastern sector (area between zocca, samone and rocca malatina) morphological elements prone to seismic amplification are evident, such as narrow and long ridges and scarps more than 20 m high. in the central and eastern sector, areas prone to seismic instability and/or amplification are found in correspondence with small superficial landslides and fine superficial deposits less then 10 m thick. 44..44.. ssttuuddyy ooff tthhee sseeiissmmiicc ssuusscceeppttiibbiilliittyy cchhaarraacctteerriissttiiccss in the study of seismic hazard applied to territorial planning, it is very important to identify those areas which may suffer more than others from the effects of an earthquake. therefore, the aim of this section is the identification of the areas and elements prone to seismic amplification and/or earthquake-induced instability on the basis of the “simplified litho-technical map” and of the “simplified geomorphological map” (see fig. 5). the first step is the identification of the areas prone to seismic amplification that show morphological and/or litho-technical features potentially causing amplification. as previously illustrated, the medvedev (1965) conservative approach was adopted. thus, considering a 0 amplification for the reference hypothetical site (granite bedrock), five classes of relative seismic amplification, from 1 to 5 (from low to high amplification), corresponding to the 5 simplified litho-technical units, were defined. in detail, areas where the rocky units (sl1) crop out were considered as having a low potential of seismic amplification (class 1). this because the rocks belonging to sl1 show (qualitatively) values of stiffness and density lower than granite but higher than other simplified litho-technical units. areas where mixed units (sl2) crop out were considered as having an intermediate-low seismic amplification (class 2). areas with argillaceous units with block-in-matrix fabric (sl3) were considered as characterised by intermediate seismic amplification (class 3). zones with superficial deposits (sl4) were considered as having an intermediate-high seismic amplification (class 4). finally, landslides (sl5) which are made of materials that generally show the lowest values of stiffness and density (relatively to the reference rock and, also, to other litho-technical units) are considered to produce the highest values of potential seismic amplification (class 5). the morphological features causing amplifications (scarps higher than 20 m, narrow and long ridges) are shown with linear symbols. the second step of this section is the identification of the areas prone to earthquake-induced instability. the features causing earthquake-induced instability are shown with zones indicated with letters from a to d according to the following classes of instability: a) stable areas and intermediate stability areas: areas where the characteristics of instability are absent or not mappable; b) potentially unstable areas with possible problems regarding the bearing capacity of soils: valley floors or flat areas with fine surface deposits; c) potentially unstable areas prone to mass movements or rock fall processes or debris detachment: areas below landslide scarps, areas below active scarps of different morphogenesis, clusters of adjacent landslides, surface slope deposits; d) unstable areas prone to mass movements: landslides of different type and activity, areas affected by deep-seated gravitational slope deformations; the earthquake-induced landslides, derived by data base of earthquake induced surface effects, are shown with a particular symbol. the quaternary faults (active or held to be active) are also shown according to the criteria described for the “simplified geomorphological maps”. the final phase consisted in the elaboration of the “maps of seismic susceptibility” by the simple combination of the areas prone to seismic amplification and the areas prone to earthquake-induced instability. this was achieved by carried out simple gis operation. the legend for the “maps of seismic susceptibility” and the map of the example area are illustrated in fig. 10. the classes of seismic susceptibility can be shown as zones with an alphanumeric code defined through the combination of numbers (from 1 to 5) and letters (from a to d), with different colours or with different areal symbols (as in fig. 15). the highest seismic susceptibility is found in correspondence with the zones classified as 5d, 5c and 5b, which means high relative amplification (5) in, respectively, unstable areas prone to mass movements (d), potentially unstable areas prone to mass movement or rock fall processes or debris detachment (c), potentially unstable areas with problems regarding the bearing capacity of soils (b). the lowest seismic susceptibi244 d. castaldini et al. 245 fig. 10 – “map of seismic susceptibility” of the zocca-rocca malatina area. the black zones correspond to the main hamlets. the legend is referred to the modena and reggio emilia apennines. “carta della suscettibilità sismica” dell’area di zocca e rocca malatina. le zone in nero indicano i principali centri abitati. la legenda si riferisce all’area dell’appennino modenese e reggiano. a methodology for medium scale ... lity is found in correspondence with the zones classified as 1a which means low amplification in stable areas or intermediate stability area. obviously, some combinations between amplification degrees and instability classes are not conceptually compatible. for example, combination 1d, that is a low amplification area in correspondence with a landslide area, cannot exist. in the example area (fig. 10) the highest amplification (class 5) is mainly found in correspondence with the numerous landslides which characterise the slopes facing the r. panaro and t. missano. on these slopes argillaceous units with block-in-matrix fabric mainly (sl3) crop out so they are prevalently characterised by intermediate amplifications (class 3). the lower amplification (classes 1 and 2) is marked in the central-eastern sector where rocky litho-technical units (mainly consisting of sandstones, sl1) and mixed units (sl2) crop out. in any case, in this sector an increase of amplification may be locally induced in the following situations: i) in wide flat-floored valleys where fine surface deposits (less than 10 m thick) crop out; ii) in correspondence of the small superficial landslides; iii) in correspondence to narrow and long ridges and scarps higher than 20 m. as concern the earthquake-induced instability (fig. 10) the unstable areas prone to mass movements are mainly found in correspondence with the numerous landslides which characterise the slopes facing the r. panaro and t. missano. in this sector potentially unstable areas, prone to mass movement or rock fall phenomena or debris detachment, are shown below landslide scarps and active scarps as well as in correspondence with surface slope deposits and clusters of adjacent landslides. the central and eastern sector (area between zocca, samone and rocca malatina) is mainly considered a stable area because rocky litho-technical units crop out. there are small unstable zones in correspondence of superficial landslides and, moreover, the wide flat-floor valleys are considered potentially unstable with problems regarding the bearing capacity of soils owing to the presence of less than 10 m thick deposits with a sandy-silty texture. therefore, in the example area the zones with the highest seismic susceptibility (5d and 5c) are the slopes facing the r. panaro and t. missano and those with the lowest seismic susceptibility (1a) characterises the main part of the area between zocca, samone and rocca malatina. it should be pointed out that, according to the goals of the research (see cap. 1) and the working scale (1:50,000), the classification adopted in the “maps of seismic susceptibility” should be considered as approximate (for example, it is not sure whether all the landslide areas might be reactivated by a seismic shock, whereas potentially unstable areas might not coincide with just those shown in the legend). therefore detailed investigations should be carried out in the areas where urban development has been planned. 55.. ffiinnaall rreemmaarrkkss aanndd ccoonncclluussiioonnss this work describes a methodology for implementation of seismic susceptibility maps for assessing seismic hazard, in other words maps of the areas prone to seismic amplification and /or earthquake-induced instability, based on geological and geomorphological studies. the studies here described are qualitative and not quantitative. the choice to adopt a qualitative approach is due to the following reasons: i) study area with large extension, complex geology and different morphological characteristics. in fact, the territory of the modena and reggio emilia provinces stretches over about 5,000 km2, its southern sector is mountainous and hilly whilst its northern sector is flat and the geological characteristics are quite complex. ii) the need to acquire standardised data all over the study area. the parameters chosen in the application of quantitative methodological approaches have to be considered local and, therefore, cannot be extended to areas having different geological and morphological characteristics. iii) short times for carrying out the research. the studies aiming at defining the knowledge on the seismic hazard of the territory of the modena and reggio emilia provinces should have been completed in two years. the methodology here adopted enabled us to define, in a relatively short time and with sufficient reliability, the seismic susceptibility in a vast territory like that of the modena and reggio emilia provinces. the resulting maps (maps of seismic susceptibility) are a sort of “alert maps” and are easily readable also by technicians from public boards. therefore, they can be useful to the provinces administration boards in giving directions in matter of territorial planning to the municipalities. considering the scale adopted (1:50,000), a grade 1 zonation can be attributed to the maps of seismic susceptibility (according to tc4, 1999). these maps are the first maps of seismic susceptibility concerning the whole territory of the modena e reggio emilia provinces. finally, it should be pointed out that, since all the data were stored in a gis and the maps produced are in a digital format, new research results may be easily incorporated. aacckknnoowwlleeddggmmeennttss this article was published with the financial support of cnr-agenzia 2000 (cnrc007e55_005, local co-ordinator doriano castaldini) and of the cerg (european centre on geomorphological hazards of strasbourg, france)(local co-ordinator mario panizza). the research was carried with a convention between the university of modena and reggio emilia and the administration boards of the provinces of modena and reggio emilia. moreover, it was part of the scientific activities of the cerg. the preliminary results of the research were presented by d. castaldini at the 5th romanian-italian workshop of geomorphology “geomorphological processes in tectonic active areas” which was held in bucharest (romania) from may 27 to june 3, 2000 (barbieri et al., 2000) and were published by castaldini et al. (2000). the research was concluded and presented to the administration boards of the provinces of modena and reggio emilia in the autumn 2001 (panizza et al., 2001). the authors are grateful to dr. floriana pergalani from the milan “cnr-istituto di ricerca del rischio 246 d. castaldini et al. sismico” and to dr. dario slejko from the trieste “istituto nazionale di oceanografia e di geofisica sperimentale” (ogs) for their critical review of this paper. rreeffeerreenncceess ambraseys n.n., sympson k.a. & bommer j.j. (1996) prediction of horizontal response spectral in europe. earth. eng. struct. dyn. 2255, 371-400. barbieri m., bettelli g., capitani m., castaldini d. & panizza m. (2000) geological and geomorphological studies in seismic hazard assesment: example in the modena apennines (northern italy). 5th romanian-italian workshop of geomorphology “geomorphological processes in the tectonic active areas”. bucharest, may 27-june 3, 2000, abstract of papers, 7-9. bartolini c., bernini m., carloni g.c., castaldini d., costantini a., federici p.r., francavilla f., gasperi g., lazzarotto a., marchetti g., mazzanti r., papani g., pranzini g., rau a., sandrelli f., & vercesi p.l. (1982) carta neotettonica dell'appennino settentrionale 1:400.000.note illustrative. boll. soc. geol. it. 110011, 523-549. bertolini g. & pellegrini m. (2001) the landslides of the emilia apennines (northern italy) with reference to those which resumed activity in the 1994-1999 period and required civil protection interventions. in: g. bertolini, m. pellegrini & g. tosatti (eds.). le frane della regione emilia-romagna oggetto di interventi di protezione civile nel periodo 19941999. quad. geol. appl., 88-1, 27-74, pitagora ed., bologna. bettelli g., capitani m. & panini f. (1994) the mesoscopic structures of a strongly deformed multilayered sequence: a hypothesis of the origin of the “block-in-matrix” fabric and the layer-parallel extension shown by ligurian dismembered formations of the baganza supergroup outcropping in the reggio emilia and modena apennines. in: post congress field trip no. 3 excursion guidebook the chaotic rocks of the southeastern sector of the emilia apennines. 1st european congress on regional geological cartography and information systems, bologna (italy) 13-16 june 1994, 29-42. bettelli g., capitani m., panini f. & pizziolo m. (1996a) le rocce caotiche dell’appennino emiliano: metodi sperimentali di rilevamento stratigrafico, esempi e nomenclatura. acc. naz. sci. lett. arti di modena, collana di studi, 1155, miscellanea geologica, 189220. bettelli g., capitani m. & panini f. (1996b) origine della struttura a "blocchi in pelite” e dell’estensione parallela alla stratificazione nelle formazioni smembrate liguri del supergruppo del baganza affioranti nel settore sudorientale dell’appennino emiliano. acc. naz. sci. lett. arti di modena, collana di studi, 1155, miscellanea geologica, 261298. bisci c. & dramis f.(1992) geomorphologic seismic zonation of the marche region (central italy) using computer assisted techniques: preliminary considerations. itc journal, 22, 196-201. bisci c., dramis f., faraboll ini p., genti l i b. & pambianchi g. (1990) proposta di un sistema di classificazione territoriale di tipo gerarchico su basi fisiografiche per la realizzazione di carte a piccola e media scala finalizzate alla zonazione sismica: l’esempio della regione marche. in: atti conv. gndt “zonazione e riclassificazione sismica” v.1: 361-379. blumetti a.m., dramis f., gentili b. & signanini p. (1987) una legenda per la cartografia degli elementi geologici e geomorfologici di pericolosità sismica. mem. soc. geol. it. 3377, 595-600, roma. bommer j.j. & rodriguez c.e. (2002) earthquake induced landslides in central america. engineering geology, 6633 (3-4), 189-220. borcherdt r.d. (1970) – effects of local geology on ground motion near san francisco bay. bull.seismol. soc. am., 60, 29-61. borghini g., bernini m. & papani g. (2000) individuazione e mappatura di faglie attive e/o strutture sismogenetiche in appennino nord-occidentale. in galadini f., meletti c. & rebez a. (a cura di) le ricerche del gndt nel campo della pericolosità sismica (1996-1999). cnr-gruppo nazionale per la difesa dai terremoti roma, 143-148. boschi e., ferrari g., gasperini p., guidoboni e., smriglio g. & valenzise g. (1995) catalogo dei forti terremoti in italia dal 461 a.c. al 1990. ed. ing.sga, bologna, 973 pp. boschi e., guidoboni e., ferrari g., mariotti d., valenzise g. & gasperini p. (eds)(2000) catalogue of strong italian earthquakes from 461 b.c. to 1997. annali di geofisica , 4433, 4, 609-869. camassi r. & stucchi m. (eds.) (1996) nt4.1 un catalogo parametrico di tertremoti di area italiana al di sopra della soglia di danno. gndt cnr, 66 pp. (version available on the website http://emidius.itim.mi.cnr.it/nt.html). camassi r., ercolani e., mirto c. & stucchi m. (2000) analisi e confronti verso la nuova mappa delle massime intensità macrosismiche osservate. in galadini f., meletti c. & rebez a. (a cura di) le ricerche del gndt nel campo della pericolosità sismica (1996-1999). cnr-gruppo nazionale per la difesa dai terremoti roma, 345-355. casali m. & castaldini d. (1998) review of earthquake-induced landslides in the modena and reggio emilia apennines (northern italy). analele universitati i din oradea, seria geografiegeomorfologie, tom. viii a, 1998, 19-33. castaldini d., genevois r., panizza m., puccinelli a. & berti m., cuzzani m.g., pieroni a., serani a. & simoni a. with contributions by putzolu p. & ghirotti m. (1997) analysis of earthquake-induced surface effects in a sample area: a methodological approach in the serchio river valley between sillano and piazza al serchio (garfagnana region, north western apennines, italy). cerg council of europe, strasbourg, amalgame impression, 52 pp., bischeim. castaldini d., genevois r., panizza m., puccinelli a., berti m. & simoni a. (1998a) an integrated approach for analysing earthquake-induced surface effects: a case study from the northern 247a methodology for medium scale ... apennines, italy. j. geodynamics, 2266 (2-4), 413441, great britain. castaldini d., panizza m. & tosatti g. (eds.) (1998b) an integrated approach for analysing earthquakeinduced surface effects: a case study in the montese area (province of modena, northern apennines, italy). cerg council of europe, strasbourg, amalgame impression, 68 pp., bischeim. castaldini d., barbieri m., bettelli g., capitani m., & panizza m. (2000) geological and geomorphological studies in seismic hazard assesment for territorial planning. cerg council of europe, strasbourg, amalgame impression, 53 pp., bischeim. castaldini d., d’amato-avanzi g., mandrone g., panizza m., pellegrini m., puccinelli a., tellini c., tosatti g. & barbieri m. (2001) historical landslides reactivated by earthquake in the nw apennines (northern italy). 5th int. conf. on geomorphology, august 23-28, 2001, tokyo. abstracts of conference papers. transactions j.g.u., 22 (4), c-35 cnr (1983) neotectonic map of italy, scale 1:500,000. p.f. geodinamica quad. ric. scient. 111144. crespellani t., madiai c., & maugeri m. (1996) analisi di instabilità di un pendio in condizioni sismiche e post sismiche. riv. it. geotecnica, 3300 (1), 50-61. crespellani t., madiai c., & vannucchi g. (1998) earthquake destructiveness potential factor and slope stability. riv. geotecnique, 4488 (3), 411-419. d’amato avanzi, g., puccinelli, a. & trivellini, m. (1993) slope stability maps in areas of particular seismic interest: a short report on the researches in garfagnana and lunigiana (tuscany). ann. geofisica, 3366 (1), 263-270. di giovanbattista r. & tyupkin y. (1999) the fine structure of the dynamics of seismicity before m>4.5 earthquakes in the area of reggio emilia (northern italy). annali di geofisica, 4422 (5). frassineti g., marcellini a., martelli l., pagani m., palumbo. a., riva f., tento a. & viel g. (1997) la microzonazione sismica nella pianificazione urbanistica e territoriale: l’esperienza del “masterplan” del rubicone e prospettive regionali. atti conv. geologia delle grandi aree urbane, bologna 4/5 novembre 1997, 212-228. frepoli a. & amato a. (1997) – contemporaneous extension and compression in the northern apennines from earthquake fault-plane solutions. geophys. j. int., 113399, 368-388. frepoli a. & amato a. (2000) – spatial variation in stresses in peninsular italy and sicily from background seismicity. tectonophysics, 331177, 109-124. galadini f., meletti c. & rebez a. (a cura di) (2000) le ricerche del gndt nel campo della pericolosità sismica (1996-1999). cnr-gruppo nazionale per la difesa dai terremoti roma, 397 pp. gasperi g., gelati r. & papani g. (1986) neogene evolution of the northern apennines on the po valley side. giornale di geologia, 48, 1-2, 187195, bologna. géli l., bard p-y., jullien b. (1988) the effect of topography on earthquake ground motion: a review and new results. bull. seism. soc. am., 7788, 42-63. genevois, r., berti m., ghirotti m., romeo r. & simoni, a. (2000) studio dei rapporti fra fenomeni franosi ed eventi sismici. cnr-gndci, linea 2, rapporto 1986-1995, tip. grifo, perugia 397-406. gruppo di lavoro cpti (1999) catalogo parametrico di terremoti italiani. ing-gndt-sga-ssn, bologna, 88 pp. (version available on the website http://emidius.itim.mi.cnr.it/cpti/home.html/). keefer d.k. (1984) landslides caused by earthquakes. geol. soc. amer. bull., 9955, 406-421. lanzo g. (1999) amplificazione del moto sismico nei depositi e nei pendii. in crespellani t. (a cura di) ingegneria geotecnica nelle aree sismiche. int. centre for mechanical sciences, 235-273. luzi l., pergalani f. & terlien m.t. j. (2000) slope vulnerability to earthquakes at subregional scale, using probabilistic techniques and geographic information systems. engineering geology, 5588, 313-336. madiai c. (1999) il manuale internazionale tc4 per la zonazione dei rischi geotecnici. in crespellani t. (a cura di) ingegneria geotecnica nelle aree sismiche. int. centre for mechanical sciences, 235273. marcellini a. & maugeri m. (eds.)(2001a) special issue.the 1997-1998 umbria-marche earthquake. riv. it. geotecnica, 3355(2), 158 pp. marcellini a. & maugeri m. (eds.)(2001b) special issue.the 1997-1998 umbria-marche earthquake. riv. it. geotecnica, 3355(4), 159 pp. margottini c., molin d. & serva l. (1992) intensity versus ground motion: a new approach using italian data. engineering geology, 3333, 45-58. mazzini e. (1994) alcuni casi di franamento indotti nel versante appenninico emiliano dal terremoto della garfagnana del 7 settembre 1920. possibili indicatori paleosismici? atti 4° convegno giovani ricercatori in geol. appl., riccione, pitagora ed. mazzini e. (1995) slope stability in seismic areas (northern apennines). atti 2° incontro internaz. giovani ricercatori in geol. appl., peveragno (cuneo), 11-13 ottobre 1994, 88-93. melett i c., patacca e. & scandone p. (2000) construction of a seismotectonic model: the case of italy. pure appl. geophys., 115577, 11-35. medvedev s.c. (1965) engineering seismology. oldobourne press, london, 260 pp. panizza m. (1991) geomorphology and seismic risk. earth-science reviews, 3311, 11-20. panizza m.(1996) environmental geomorphology. developments in earth surface processes, 44, elsevier, amsterdam, 268 pp. panizza m. & castaldini d. (1987) neotectonic research in applied geomorphological studies. z. geomorph. n. f., suppl.-bd., 6633, 173-211. panizza m., bettelli g., castaldini d., barbieri m. & capitani m. (2001) studio della pericolosità simica delle province di modena e reggio emilia. relazione finale. dipartimento di scienze della terra, università degli studi di modena e reggio emilia. rapporto interno. 214 pp. paolucci r. (2002) amplification of earthquake ground motion by steep topographic irregularit ies. earthquake engng. struct. dyn., 3311, 1831-1853. pellegrini m. & tosatti g. (1982) alcuni esempi di frane 248 d. castaldini et al. determinate da sismi nell’alto appennino modenese e reggiano. atti soc. nat. mat. di modena, 111133, 1-20. pergalani f. (1996) (a cura di) – determinazione del rischio sismico a fini urbanistici in lombardia. regione lombardia, cnr istituto di ricerca sul rischio sismico. 182 pp. pergalani f., padovan n., agostoni s., belloni a., costantini r., crosta g., de andrea s., laffi r., luzi l. & sterlacchini s. (1998) valutazione della stabilità dei versanti in condizioni statiche e dinamiche nell’oltrepò pavese. regione lombardia, cnr istituto di ricerca sul rischio sismico, 88 pp. pergalani f., romeo r., luzi l., petrini v., pugliese a. & sano' t. (1999) seismic microzoning of the area struck by the umbria-marche (central italy) ms 5.9 earthquake of 26 september 1997. soil dynamic and earthquake engineering, 1188, 279296. pergalani f., petrini v., romeo r., pugliese a., boscherini a., checcucci r., felicioni g., luchetti l., martini e., motti a., ponziani f., simone g., sorrentino a., luzi l. & sano' t. (a cura di)(2000) la microzonazione sismica speditiva relativa ai terremoti del 1997-98 in umbria. le situazioni morfostratigrafiche suscettibili di amplificazione sismica locale. regione dell'umbria, cnr-irss, tip. visconti, terni, 232 pp. pergalani f., compagnoni m. & petrini v. (2002) valutazioni degli effetti di sito in alcuni centri dell'alta val tiberina umbra tramite modellizzazione numerica. ingegneria sismica, 11, 44-56. peruzza l., rebez a. & slejko d. (2001) seismic hazard mapping for administrative purposes. natural hazards, 2233, 431-442 phillips s.w. & aki k (1986) – site amplification of waves from local earthquakes in central california. bull. seimol. soc. am., 7766, 627-648. pieri m. & groppi g. (1981) subsurface geological structure of the po plain, italy. cnr, pubbl. 414, p. f. geodinamica, 1133, 7, 13 pp. postpischl d. (ed.) (1985) catalogo dei terremoti italiani dall’anno 1000 al 1980. p.f. geodinamica, cnr. rer-cnr (regione emilia-romagna—consiglio nazionale delle ricerche) (1980) catalogo dei terremoti della regione emilia-romagna. collana di orientamenti geomorfologici ed agronomicoforestali, pitagora ed., bologna, 149 pp. regione emilia-romagna (2002) carta geologica d'italia a scala 1:50.000. pavullo nel frignano 236. servizio geologico d'italia. regione toscana (2000) – istruzioni tecniche per le indagini geologico-tecniche, le indagini geofisiche e geotecniche, statiche e dinamiche, finalizzate alla valutazione degli effetti locali nei comuni classif icati sismici. “progetto terremoto” in garfagnana e lunigiana. regione toscana, dip. delle politiche territoriali e ambientali, u.o.c. rischio sismico, pp.228. romeo r. & delfino l. (1997) catalogo nazionale degli effetti deformativi del suolo indotti da forti terremoti. cedit, servizio sismico nazionale, rapporto tecnico, ssn/rt//97/04, roma (version available on the website http://www.dstn.it/ssn/rt/rt9704/ framese.html) siro l. (1985) i contributi geologici, geotecnici e geofisici alla microzonazione sismica e gli approcci semplificati. atti 1º workshop “aree sismogenetiche e rischio sismico in italia”, erice, 27/8-5/9 1985, 399-447. siro l. & bigi g. (eds.) (1983) indagini di microzonazione sismica intervento urgente in 39 centri abitati della campania e basilicata colpiti dal terremoto del 23 novembre 1980. c.n.r. p.f. geodinamica, 449922, 219 pp. slejko d., peruzza l. & rebez a. (1998) seismic hazard maps of iyaly. annali di geofisica, 4411, 183214. state of california (1997) – guidelines for evaluation and mitigation of seismic hazards in california. spec. pubbl. 117 (http://www.conserv.ca.gov). tc4 (1999) – manual for zonation on seismic geotechnical hazards. technical committeee for earthquake geotechnical engineering, tc4, issmfe, jap. soc. soil mech. & eng. 149 pp. zecchi r. (1987) effetti geomorfologici causati dai terremoti in emilia romagna. acta nat. ateneo parmense, 2233, 87-96. zucchi m. (1995) rete per il rilevamento della sismicità naturale delle province di modena e reggio emilia: annuario sismico 1994. comune di modena, 26 pp. zucchi m. (1996) rete per il rilevamento della sismicità naturale delle province di modena e reggio emilia: annuario sismico 1995. comune di modena, 20 pp. zucchi m. (1997) rete per il rilevamento della sismicità naturale delle province di modena e reggio emilia: annuario sismico 1996. comune di modena, 33 pp. zucchi m. (2000) rete per il rilevamento della sismicità naturale delle province di modena e reggio emilia: annuario sismico 1997, 1998, 1999. comune di modena, 47 pp. zucchi m. (2001) rete per il rilevamento della sismicità naturale delle province di modena e reggio emilia: annuario sismico 2000. comune di modena, 31 pp. 249 ms. ricevuto il 26 marzo 2002 testo definitivo ricevuto l’8 gennaio 2003 ms. received: march 26, 2002 final text received: januari 8, 2003 a methodology for medium scale ... imp.capezzuoli& i “travertini” in italia: proposta di una nuova nomenclatura basata sui caratteri genetici. enrico capezzuoli & anna gandin dipartimento di scienze della terra, via laterina 8, 53100 siena. e.mail: capezzuoli@unisi.it; gandin@unisi.it riassunto: capezzuoli e. & gandin a., i “travertini” in italia: proposta di una nuova nomenclatura basata sui caratteri genetici. (it issn 0394-3356, 2004). il termine “travertino” viene generalmente usato in italiano per indicare indistintamente un’ampia varietà di carbonati continentali deposti da acque lacustri, palustri o fluviali, oppure da sorgenti calde o fredde, formatisi cioè in condizioni chimico-fisiche, biologiche e climatiche anche molto differenti. i risultati delle ricerche più recenti indicano che queste differenze si riflettono sia sui caratteri geochimici sia sui caratteri litologici di questi depositi che sono tuttora in formazione e di cui si ritrovano abbondanti tracce nel recente passato. i caratteri distintivi dei vari tipi di carbonati sono tutt’ora argomento di discussione ma è opinione di molti autori che sulla base dei caratteri petrologici affiancati anche da quelli geochimici, sia possibile effettuare una classificazione genetica affidabile. in conseguenza sarebbe logico che solamente i depositi concrezionari collegati alle sorgenti idrotermali vengano denominati travertino che è un termine nato per i depositi formatisi intorno alle sorgenti calde di tivoli. i travertini di norma sono relativamente poco influenzati dai fattori climatici, sono caratterizzati da facies prevalentemente cristalline disposte secondo una regolare laminazione, mostrano alti tassi di accrescimento, scarso contenuto organico e un arricchimento in c13, carbonio inorganico disciolto totale, magnesio, stronzio e zolfo. d’altra parte, per i carbonati continentali non termali, derivati cioè da acque fredde di origine sia fluvio-palustre sia di sorgente, è stato coniato nella letteratura anglosassone più recente il nome di calcareous tufa. essi si formano come incrostazioni carbonatiche su supporti formati prevalentemente da organismi vegetali superiori (briofite, giunchi, ecc.) con tassi di deposizione di norma bassi, sono influenzati dalle condizioni climatiche, e contengono basse concentrazioni di tdic, di stronzio e di magnesio con accentuato impoverimento in c13. per rendere più facili le correlazioni e la comprensione nella comunità scientifica, si ritiene necessario normalizzare anche in italiano la terminologia dei carbonati continentali. a tale scopo si propone di riservare il termine travertino solo ai carbonati continentali deposti in corrispondenza di un sistema di sorgente termale, e di utilizzare il termine calcareous tufa per i carbonati precipitati da acque a temperatura ambiente in sistemi fluvio-palustri. abstract: capezzuoli e. & gandin a., the “travertine” in italy: proposal of a new nomenclature based on the genetics characters. (it issn 0394-3356, 2004). the word “travertine” in the common italian language, is generally used for a variety of continental carbonates deposited by hotor cold-waters, in the surroundings of spring vents, or in fluvial, palustrine or lacustrine systems. the geochemical signature as well as the lithological and petrographic features of these limestones, appear to be controlled by the physiochemical conditions of the spring waters and/or the depositional environment and climate. the results of recent research indicates that the petrologic features can be used for a genetic classification. the term travertine, which for a long time has been used to designate the ornamental/building stone quarried in the thermal deposits of tivoli, should be reserved to calcium carbonate deposits associated to hydrothermal spring systems. this lithology which is slightly enriched in 13c, tdic, strontium and sulphur, appears to be hardly dependent upon climate. it is characterized by a primary, low-porosity crystalline fabric, fine daily laminae, and by bacteria and cyanophytes as the dominant organic components. on the other hand, the term calcareous tufa, coined in the british literature, refers to calcium carbonate deposits formed under a cool water regime, around karst spring complexes and/or in a fluvio-palustrine environment. this lithology which is depleted in 13c and shows tdic concentrations more or less in equilibrium with the soil atmosphere, appears to be highly dependent upon climatic factors. it is characterized by normally low depositional rates, poor bedding, commonly lenticular, highly porous bodies and abundant remains of microand macrophytes, bacteria and invertebrates. the distinction between these two groups of lithotypes is not univocal since the cool water calcareous tufa deposits are often found as the natural lateral prosecution of travertines far from the thermal-spring complex. however preliminary, compared analyses of travertine and calcareous tufa fabrics show the possibility of using petrographic criteria for their distinction. the discrimination of the two types of deposits appear to be essential in the interpretation of the tectonic, climatic and anthropologic meaning of the fossil continental carbonates. for this reason, it is important that the scientific community working on continental carbonates adopt even in italy a suitable terminology reserving the term travertine for the deposits deriving from hot-spring complexes, and calcareous tufa for the sediments deposited near cold water springs and in fluvialpalustrine systems. parole chiave: calcareous tufa; calcari continentali; nomenclatura. keywords: travertine, calcareous tufa, continental carbonates, classification. il quaternario italian journal of quaternary sciences 17(2/1), 2004, 273-284 1. introduzione i depositi carbonatici continentali rappresentano una particolare categoria di sedimenti che negli ultimi anni hanno attirato l’interesse dei ricercatori per le informazioni che possono fornire. la loro distribuzione a livello planetario è strettamente legata alla presenza di corpi rocciosi carbonatici che rendono possibile l’arricchimento in calcio delle acque meteoriche circolanti. non esiste una classificazione univoca di questi depositi, ma è comunque possibile individuare i principali litotipi sulla base dei processi genetici e degli ambienti deposizionali. vengono infatti, differenziati: gli speleotemi (sedimenti formatisi in grotte carsiche), le calcrete 274 e. capezzuoli & a. gandin (collegati a processi pedogenetici), e con il generico termine “travertino” i calcari concrezionari originariamente depositati come fanghi in ambiente lacustre, quelli precipitati da acque carbonatate calde in corrispondenza di sorgenti termali, o da acque carbonatate a temperatura ambiente in corrispondenza di sorgenti carsiche e/o di sistemi fluvio-palustri (cipriani et al., 1972, 1977; ferreri, 1985; foucault & raoult, 1986). tuttavia è ormai accertato (ford & pedley, 1996 cum bibl.). che in queste differenti condizioni deposizionali, i fattori chimico-fisici, biologici, climatici e le condizioni geomorfologiche vengono registrate nei carbonati da litologie diverse con caratteri propri. ne deriva che l’uso di un unico e generico nome di “travertino”, per indicare depositi formati in situazioni deposizionali così differenti, porta ad una grossa perdita di informazione. in questo contesto si ritiene opportuna una revisione del termine “travertino”, così come è stato finora usato nella terminologia italiana e, tenendo conto delle possibilità di un migliore scambio con la comunità scientifica, un suo adeguamento agli standard internazionali. 2. conoscenze generali i calcari concrezionari sono costituiti principalmente da carbonato di calcio (caco3) sotto la forma minerale calcite e, più raramente aragonite. la loro composizione geochimica dipende dalla composizione chimica delle acque da cui precipitano, che a sua volta deriva dalle condizioni della circolazione sotterranea. infatti le acque di origine meteorica che penetrano nel sottosuolo, possono acquisire ioni per dissoluzione delle rocce carbonatiche e/o solfatiche nella zona vadosa di un sistema carsico oppure circolare in profondità, riscaldarsi in funzione del locale gradiente termico, e tornare in superficie lungo faglie e fratture. queste acque, oltre agli ioni calcio, possono anche contenere quantità variabili di elementi in tracce quali ferro, manganese, stronzio e zolfo a seconda della natura delle rocce dissolte. la formazione dei calcari concrezionari avviene con un processo chimico reversibile che induce la precipitazione del carbonato di calcio per degassazione delle acque arricchite in ioni calcio (ca2+) (herman & lorah, 1987) e conseguente ritorno dell’anidride carbonica (co2) nell’atmosfera. la degassazione, e di conseguenza la deposizione del caco3, è controllata da una complessa interazione di fattori inorganici ed organici, alcuni dei quali non ancora completamente esemplificati (herman & lorah, 1988; julià, 1983). fra i fattori inorganici, di natura essenzialmente fisica, sono di fondamentale importanza le variazioni della pressione parziale della co2 e della temperatura delle acque. anche la turbolenza e la vaporizzazione dell’acqua, indotta dai dislivelli morfologici come avviene in corrispondenza di una cascata, possono localmente essere determinanti per la precipitazione del calcare. fra i fattori organici è da ricordare il ruolo degli organismi vegetali che sottraendo dalle acque la co2 necessaria per il processo di fotosintesi e la produzione di carboidrati, possono anche innescare la precipitazione di caco3. per quanto riguarda l’interazione fra i cianobatteri e la precipitazione della calcite sia in acque calde sia in acque fredde, è tuttora in discussione il ruolo attivo o passivo di questi organismi (golubic et al.,1993; folk,1994; guo et al., 1996; pentecost & whitton, 2000; riding, 2002). in generale, comunque, le cause abiotiche e biotiche operano spesso nella stessa direzione con la produzione di calcari concrezionari, ma è chiaro che il loro contributo relativo varia in funzione del tipo di ambiente di sedimentazione. infatti la precipitazione di carbonato di calcio appare essere prevalentemente inorganica nelle vicinanze di sorgenti idrotermali, dove le condizioni chimico-fisiche limitano il proliferare della vita. allontanandosi da queste, tali condizioni cambiano progressivamente fino ad arrivare ad ambienti palustri o fluviali dove le caratteristiche chimico-fisiche delle acque favoriscono la colonizzazione biologica e quindi prevale la precipitazione bioindotta (violante et al., 1994). 3. classificazioni dei carbonati continentali incrostanti i primi autori in italia che hanno studiato con qualche dettaglio i carbonati continentali, da loro indistintamente denominati “travertini”, ne hanno individuato i caratteri giaciturali, e genetici (boni & colacicchi, 1966), o mineralogici e geochimici (contenuto in stronzio e residuo insolubile; cipriani et al. 1972; 1977; caboi et al., 1991) oppure geochimico-isotopici (elementi maggiori e minori,δ13c e δ18o: per esempio: fritz, 1965; gonfiantini et al., 1968; manfra et al., 1976; turi, 1986; bellanca et al., 1991). la prima classificazione organica, basata sui caratteri tessiturali dei calcari continentali dell’italia meridionale deposti prevalentemente da acque a temperatura ambiente, è stata effettuata da buccino et al. (1978) e integrata ed ampliata in successivi lavori (d’argenio et al., 1983; ferreri 1985; brancaccio et al., 1986; d’argenio & ferreri 1988; violante et al., 1996) (fig. 1) . l’utilità di tale classificazione è stata riconosciuta oltre che dagli autori italiani (carrara, 1998; fioraso, 1999) anche a livello internazionale (pedley, 1990, ford & pedley, 1996). i depositi carbonatici derivati da acque idrotermali non sono stati ancora oggetto di una classificazione sistematica. tuttavia i risultati delle prime indagini effettuate su depositi antichi e tuttora in formazione a rapolano terme (guo & riding, 1992; 1994; 1998; 1999), tivoli (chafetz & folk, 1984.), viterbo zitelle (folk, 1994), bagno vignoni (pentecost, 1994), mostrano che questi depositi possiedono caratteristiche litologiche diverse e ben distinguibili rispetto a quelle dei carbonati originati da acque “fredde”. tra le litofacies distinte da guo & riding (1998), le facies di shrub, crystalline crust, paper-thin raft, coated bubble sembrano essere esclusive di depositi connessi all’attività termale. alcune di queste infatti sono state segnalate anche da altri autori nei carbonati termali di tivoli e rapolano terme (folk et al., 1995), in quelli di canino (carrara, 1994) ed in colorado (usa) (chafetz et al., 1991). queste due classificazioni mettono in risalto le differenze esistenti tra i caratteri tessiturali dei carbonati continentali di acque fredde e di acque calde e contengono solo alcune litofacies che possono essere ritenute tra loro comparabili, rispettivamente i travertini fitoermali, fitoclastici e le sabbie calcaree (d’argenio et al., 1983) e i reed travertine e i lithoclast travertine (guo & riding, 1998), con queste ultime che possono essere considerate di transizione tra un sistema deposizionale e l’altro. differenze che sono state riconosciute anche da molti autori (chafetz &folk, 1984; pedley, 1990; viles & goudie, 1990; koban & schweigert, 1993; pentecost & viles 1994; pentecost, 1995; ford & pedley 1996; glover e robertson, 2003) e che utilizzano in conseguenza una nomenclatura specifica, basata sui caratteri genetici di questi due tipi di depositi (fig. 2). 4. nomenclatura internazionale nella recente letteratura anglosassone il termine ital iano “travertino” trova la sua controparte in travertine, ma non mantiene la molteplice valenza ambientale che gli viene attribuita nella letteratura italiana. infatti questo viene di preferenza riferito ai sedimenti carbonatici prodotti nelle vicinanze di sorgenti idrotermali e con fabric primario cristallino (ford & pedley, 1996; riding, 2002). per quanto riguarda i carbonati continentali non termali, derivati cioè da acque di origine sia fluvio-palustri sia di sorgente carsica, nella letteratura anglosasso275i “travertini” in italia ... fig. 2 diagramma delle relazioni genetiche fra i differenti tipi di carbonati continentali, secondo koban & schweigert (1993). the different types of continental carbonates and their genetic relationships according to koban & schweigert (1993). fig. 1 schemi delle caratteristiche tessiturali riconosciute da d’argenio & ferreri (1988) nei carbonati continentali di acque a temperatura ambiente. textural classification of ambient water continental carbonates (after d’argenio & ferreri 1988). 276 ne viene oggi principalmente utilizzato il termine calcareous tufa o tufa (ford & pedley, 1996; pedley, 1990), che deriva dalla parola latina “tophus” con cui plinio indicava materiali da costruzione (calcarei o vulcanici) teneri e di facile estrazione (ford & pedley, 1996; julià, 1983). questo nome include una varietà di termini (kalktuff in tedesco, tuf calcaire in francese) tendenti a sottolineare l’origine di questi depositi da acque a temperatura ambiente per differenziarli da quelli originatisi da acque termali. si sottolinea, comunque, come tale terminologia non è accettata né utilizzata globalmente. infatti sempre nella letteratura anglosassone, è stata proposta una nomenclatura alternativa per la distinzione genetica dei carbonati continentali (pentecost, 1995; pentecost & viles, 1994) che prevede il termine di thermogene travertine per i depositi formatisi in acque idrotermali, mentre con meteogene travertine vengono indicati i depositi originati da acque a temperatura “ambiente”. inoltre la stessa molteplice accezione genetica della parola “travertino” è presente, come in italia, anche in parte della letteratura relativamente recente francese, americana e spagnola (lang et al., 1992; demicco & hardie, 1994; martìn-algarra et al., 2003). 5. caratteri litologici-petrologici dei carbonati continentali lo studio delle litofacies e delle associazioni di facies dei depositi carbonatici attualmente in formazione presso sorgenti termali o presso sorgenti carsiche e negli associati sistemi fluvio-palustri, evidenzia una serie di caratteri esclusivi, che permettono di distinguere due gruppi di depositi corrispondenti i primi ai travertini e gli altri ai calcareous tufa. 5.1. travertini – i carbonati continentali di origine idrotermale il termine travertino deriva dal latino lapis tiburtinus o “pietra di tivoli”, città alle porte di roma dove questo materiale è stato largamente estratto fin dai tempi dei romani per l’edilizia dell’urbe. il travertino/travertine, in senso stretto, è una roccia caratterizzata da facies laminari compatte, formate da cristalli di calcite anche molto sviluppati (chafetz & folk, 1984) e, in minor quantità, da lamine microcristalline, organogene e granulari o fangose, generalmente più porose (fig. 3). l’estensione laterale degli affioramenti è molto variabile e gli ambienti deposizionali rappresentati mostrano una limitata diversità (ford & pedley, 1996). in generale i depositi calcarei riferibili al travertino sono scarsamente influenzati dai fattori climatici, presentano tassi di accrescimento anche elevati e scarsità di organismi vegetali superiori (fig. 4). dal punto di vista geochimico, presentano di norma un debole arricchimento in c13, alti contenuti in carbonio inorganico disciolto totale (tdic), magnesio, stronzio (cipriani et al., 1972; pentecost & viles, 1994; pentecost, 1995; ford & pedley, 1996) e zolfo (turi, 1986). fig. 3 aspetto tipico del travertino deposto in corrispondenza delle sorgenti idrotermali di bagnarello di tolfa (roma) a sinistra, e dell’acqua borra (siena) a destra. typical travertine lithofacies at the hydrothermal spring of bagnarello di tolfa (roma) left, and at acqua borra (siena) right. e. capezzuoli & a. gandin 277 benchè la caratterizzazione petrologica del travertino non sia stata ancora approfondita, e in particolare le ricerche sulla sua diagenesi siano poco sviluppate (love & chafetz, 1988; 1990; chafetz & guidry, 2003), il risultato delle ricerche effettuate sui depositi antichi e quelli tuttora in formazione presso le sorgenti idrotermali di rapolano terme (chafetz & folk, 1984; folk et al.,1985; barazzuoli et al., 1988; guo & riding 1998; 1999; gandin et al., 2002) mostrano che i travertini, intesi come depositi che si formano da acque calcaree calde nelle immediate vicinanze di un complesso idrotermale, hanno fabric specifici, caratteristici dei vari microambienti deposizionali. i diversi litotipi distinti (crystalline crust, shrub, paper-thin raft, coated bubble, pisoid, lithoclast, reed travertine; guo & riding, 1998) e le diverse associazioni di facies riconosciute, sono caratteristici, essenzialmente di due ambienti deposizionali (ford & pedley, 1996) che spesso interagiscono e si alternano tra loro: a) dorsali di travertino corrispondono a risorgenze lineari più o meno rettilinee lungo faglie e fratture del terreno, dove le acque termali ed i gas sotterranei risalgono e scaturiscono in superficie. qui il carbonato di calcio precipita formando inizialmente piccoli coni che successivamente per coalescenza, creano dorsali di travertino più o meno estese e più o meno elevate, a seconda della velocità di precipitazione e della durata dell’attività della sorgente. nel caso di sorgenti puntiformi si formano veri e propri pinnacoli di travertino. a rapolano terme esiste uno dei più importanti e tra i più studiati esempi di dorsale di travertino al mondo (terme di san giovanni; guo & riding, 1992, 1994, 1998, 1999) (fig.4). b) terrazzi il fluire delle acque calde che si allontanano dalla sorgente ne provoca un graduale raffreddamento con conseguente precipitazione del carbonato di calcio in corrispondenza degli ostacoli presenti sul percorso. si formano così dighe e barriere che individuano pozze di varia misura (anche millimetriche) fino a piscine di acqua termale (fig. 4). da queste prime si dipartono una serie di vasche sussidiarie a quote inferiori che solitamente si allargano a ventaglio da quella principale. la maggiore o minore altezza del complesso consente l’eventuale sviluppo di cascate, microterrazze e canali sospesi. caratteristica comune di questi edifici travertinosi è la totale assenza di vegetazione superiore nelle immediate vicinanze della zona di deposizione (fig. 4). gli esempi più imponenti si trovano negli stati uniti (parco di yellowstone: fouke et al. , 2000 cum bibl. ) e in turchia (pamukkale, altunel & hancock, 1993). 5.2. calcareous tufa i carbonati continentali di acque fredde le località di affioramento dei depositi derivati da acque a temperatura ambiente o fredde risultano essere più numerose di quelle dei carbonati di acque termali, come pure, di norma è maggiore l’estensione laterale (ford & pedley, 1996). gli ambienti deposizionali, compresi in sistemi fluvio-palustri, sono diversificati e si susseguono lateralmente in maniera continua e casuale, anche a causa dello sviluppo di floride comunità vegetali e animali che determinano modificazioni geomorfiche, spesso rilevanti, lungo il percorso delle acque (violante et al., 1996). la roccia che si deposita è normalmente caratterizzata da una poco evidente stratificazione e da un’alta porosità (fig. 5). ambedue le caratteristiche sono da mettere in relazione alla incrostazione in posto di piante palustri, di accumuli disordinati di frammenti di steli oppure di batteri, alghe e briofite che formano concrezioni laminari. la classificazione di queste litofacies e dei relativi caratteri tessiturali è dovuta a buccino et al. (1978), i quali riconoscono varie facies: fitoclastica e bibliolitica, fitoermale, stromatolitica e sabbie calcaree. successivamente sono state definite le associazioni di litofacies collegate con i differenti sub-ambienti: lacustre-palustre, palustre, di pendio poco acclive, di pendio acclive, di gradinata di vasche, di cascata (d’argenio et al., 1983; ferreri 1985; brancaccio et al., 1986; d’argenio & ferreri 1988). in letteratura sono state proposte altre classificazioni, solo in parte derivate da quella di buccino et al., (1978), basate sulle caratteristiche sedimentologico-petrologifig. 4 esempi di ambienti deposizionali dei travertini: dorsale presso le terme di san giovanni (rapolano terme, siena) a sinistra; complesso di terrazzi presso le sorgenti termali di pamukkale (turchia) a destra. si noti la caratteristica assenza di vegetazione. examples of travertine depositional systems: left mound near the thermal spring of san giovanni (rapolano terme, siena); right – terrace complex near the thermal springs of pamukkale (turkey). notice the characteristic absence of vegetation. i “travertini” in italia ... 278 che di questi depositi (viles & goudie, 1990; pentecost & viles, 1994; pentecost, 1995; ford & pedley, 1996). altri criteri di classificazione dei calcareous tufa sono basati su parametri di tipo fisiochimico e biochimico (geurts, 1976), geomorfologico (symoens et al., 1951), botanico (pentecost & lord, 1988) e sulle associazioni di facies e ambienti di deposizione (ordoňez & garcia del cura; 1983; pentecost, 1995; ford & pedley, 1996) (fig. 6). in generale, comunque, tutti gli autori concordano sul fatto che la loro formazione è strettamente dipendente dalle condizioni climatiche, con tassi di deposizione di norma bassi. i caratteri petrografici sono stati illustrati da vari autori (irion & müller, 1968; braithwaite, 1979; love & chafetz, 1988; lang et al., 1992; violante et al., 1994 cum bibl.), ma non esiste ancora una classif icazione sistematica. geochimicamente essi possiedono una bassa concentrazione di tdic circa in equilibrio con l’atmosfera del suolo, scarsi contenuti di stronzio, magnesio e un accentuato impoverimento in c13 (pentecost & viles, 1994; pentecost, 1995; ford & pedley, 1996). va sottolineato come i calcareous tufa si possano trovare anche associati ai travertini dei quali possono rappresentare la naturale continuazione laterale. infatti essi si formano anche da acque di origine idrotermale le cui condizioni chimiche-fisiche, per diluizione, raffreddamento e depletamento, sono diventate accessibili per la colonizzazione da parte di piante superiori (ford & pedley, 1996). in generale ai calcareous tufa corrispondono tre tipi di ambienti deposizionali: 1) fiumi lungo i corsi d’acqua la precipitazione di carbonato di calcio dà origine a depositi prevalentemente fitoclastici, associati a livelli sabbiosi derivati dall’ulteriore frammentazione dei fitoclasti da parte delle correnti fluviali. localmente, in corrispondenza di sbarramenti (fig. 6), si possono formare dighe calcaree (sbarramento delle marmore; carrara et al., 1995; mai maikden in etiopia: berakhi et al., 1998), costituite da depositi fitoermali, bioerme algali e stromatoliti, con lo sviluppo verso monte di laghi anche molto estesi come nel caso di plitvice, in croazia (emeis et al., 1987 cum bibl.). 2) sorgenti sospese, terrazzi e cascate – di solito i calcareous tufa si sviluppano vicino alla sorgente come terrazzi solitamente lobati (perched springline: pedley et al., 2003) o al piede della rottura di pendio (cascate). nelle aree frontali dei terrazzi, i lobi, generalmente molto acclivi, sono intensamente colonizzati da alghe, muschi ed epatiche (briofite) che formano cospicue strutture fitoermali e microermali. 3) laghi e paludi ai margini dei bacini lacustri e nelle zone poco drenate si formano stagni o paludi intensamente colonizzati da macrofite, briofite alghe e batteri. si formano quindi calcareous tufa composti da bioerme algali, biblioliti, stromatoliti e sedimenti fitoclastici (carrara 1998; glover & robertson, 2003). talora in condizioni climatiche particolarmente umide, la quantità di vegetazione è tale che fig .5 esempi tipici di calcareous tufa a) facies fitoermali e b) cuscini di briofite presso poggibonsi (siena); c) piscine e piccole cascate lungo il fiume elsa presso colle val d’elsa, (siena). examples of typical calcareous tufa: a) phytohermal facies and b) briophyte pillows near poggibonsi (siena); c) pools and small falls along the elsa river near colle val d’elsa (siena). e. capezzuoli & a. gandin in parte non viene incrostata per cui si formano accumuli di materia organica che con il tempo tende a carbonizzare (torba). 6. il significato geologico e ambientale dei carbonati continentali le sorgenti termali e le relative acque calcaree che formano i travertini devono la loro origine a sistemi di faglie attraverso le quali le acque meteoriche discendono in profondità, si scaldano sia per gradiente geotermico o per l’attraversamento di aree con gradiente geotermico anomalo, sciolgono i sali della roccia incassante che depositano risalendo in superficie (minissale, 1991). la genesi dei calcareous tufa invece appare strettamente legata a fattori climatici, in quanto il carbonato disciolto ha origine principalmente dai suoli e dai connessi fenomeni di carsismo (goudie et al., 1993; pentecost, 1995). dal punto di vista applicativo, il riconoscimento delle condizioni genetiche dei carbonati continentali apporta informazioni immediate, utili per ottenere ricostruzioni paleogeografiche ed effettuare, oltre alle normali interpretazioni sedimentologico-stratigrafiche, anche ricostruzioni tettoniche (hancock et al., 1999), mentre i calcareous tufa possono essere diagnostici dell’andamento climatico di un’area e dell’impatto antropico verificatosi nel recente passato (goudie et al., 1993; cilla et al., 1994; andrews et al., 1997; dramis et al., 1999). 7. proposta per la nomenclatura in italia solo recentemente anche nella letteratura italiana si inizia a riconoscere il dualismo presente all’interno del termine “travertino”. in alcuni articoli riguardanti i carbonati continentali, è stata adottata una terminologia genetica che tende a distinguere le facies calde (hot water-acque calde-thermal water travertine) da quelle fredde (ambient water-acque a temperatura ambientecold water travertine) (violante et al. 1994; violante et al., 1996; d’argenio 2001), mentre minissale et al., (2002) utilizzano la nomenclatura meteogene/thermogene travertine proposta da pentecost (1995). allo scopo di unificare la terminologia italiana a 279 fig. 6 schema di classificazione dei calcareous tufa in funzione del fabric da: ford & pedley (1996). classification of the calcareous tufa on the basis of fabric type. after ford & pedley (1996). i “travertini” in italia ... quella internazionale e quindi di rendere più facile la comunicazione scientifica con l’immediata correlazione tra appellativo usato, roccia e sistema deposizionale, si propone l’uso di due diversi termini per indicare questi due diversi tipi di carbonati continentali. la parola travertino, nata per indicare i calcari che si formano intorno alle sorgenti calde di tivoli, dovrebbe designare esclusivamente i depositi di origine idrotermale, mentre per indicare i carbonati precipitati da acque fredde, a temperatura ambiente in sistemi fluvio-palustri alimentati da sorgenti di acque calcaree, si ritiene che calcareous tufa, in diretta correlazione con la lingua latina anche se “re-inventato” dalla letteratura anglosassone, sia il termine più adeguato. l’italianizzazione del termine calcareous tufa in “tufa calcareo” è sconsigliabile per due ragioni: la prima perché la comunicazione scientifica oggi si effettua essenzialmente in inglese, la seconda per evitare confusioni con la dizione “tufo calcareo” che è entrata nell’uso comune in puglia per indicare una formazione calcarenitica marina pliocenica molto utilizzata nell’edilizia locale (caputo et al., 1996; cherubini et al., 1996; m.tropeano com. pers.). per la stessa ragione è sconsigliabile il termine “tufa”, abbreviativo di calcareous tufa nella terminologia anglosassone, che può essere confuso con la parola “tufo” classicamente usato per caratterizzare i sedimenti vulcanici piroclastici. per l’individuazione dei due tipi di carbonati, le caratteristiche generali suggerite da pentecost (1995) e ford & pedley (1996), e condensate in questo studio possono costituire una valida base di differenziazione. tuttavia, poiché le conoscenze e i dati a nostra disposizione sulla genesi dei travertini, dei calcareous tufa e di tutti i termini intermedi sono ancora limitati e non sono stati ancora esaurientemente illustrati i caratteri petrologici distintivi delle numerose litofacies, la nomenclatura qui proposta potrà essere verificata in futuro sulla base di un maggior numero di dati sia chimico-isotopici sia, e soprattutto, di tipo petrografico. 8. problematiche connesse e implicazioni paleoambientali allo stato attuale delle conoscenze, è evidente come non sia facile contenere tutte le molteplici variazioni di facies, di ambiente e di deposizione dei carbonati concrezionari all’interno di un semplice schema. molte delle definizioni fondamentali necessarie per una classificazione rigorosa sono tuttora in discussione. un esempio è fornito dalla definizione di sorgente calda, concetto necessario per la distinzione fra carbonati concrezionari “caldi” e “freddi”. esistono molte classificazioni delle acque in base alla temperatura (es. desio, 1973; celico, 1986); la più recente distinzione effettuata da pentecost et al. (2003) prevede la temperatura di 36.7 c° come limite fra le due classi, ma gli stessi autori raccomandano che i termini caldo e freddo siano sempre accompagnati dal criterio utilizzato per la loro definizione e dal range della temperatura delle acque. allo stesso modo essi pongono l’attenzione sull’uso dell’aggettivo ambiente per caratterizzare le acque con una temperatura simile a quella dell’atmosfera in corrispondenza della sorgente, ritenendolo un termine ambiguo, perché strettamente connesso alla latitudine/clima dell’area e quindi non utilizzabile per correlazioni globali. uno dei maggiori problemi nella realizzazione di una distinzione estremamente schematica dei carbonati concrezionari, è sicuramente legato alla naturale transizione che esiste fra quelli caldi e quelli freddi. infatti è evidente come in questi casi, in cui facies calde evolvono lateralmente a quelle fredde in funzione di variazioni chimiche-fisiche di difficile schematizzazione e variabili da caso a caso, la distinzione risulta molto complessa se non nei loro termini estremi. questi ultimi, infatti, sono sicuramente identificabili sul terreno, per cui la definizione dei termini intermedi può essere compiuta con maggiore dettaglio in laboratorio con l’ausilio di analisi petrografiche, geochimiche e isotopiche. in sostanza la differenziazione dei travertini dai calcareous tufa può essere effettuata in base alle caratteristiche generali del litotipo (porosità, contenuto organico, fabric, caratteristiche geochimiche…) e tenendo comunque presente che fattori locali possono anche influenzare le caratteristiche tessiturali e/o geochimiche dei singoli litotipi. 9. discussione tra i carbonati continentali deposti da acque sorgive, i calcareous tufa sono stati oggetto, come già detto, di una embrionale caratterizzazione petrografica, mentre per i travertini non esiste ancora una analisi approfondita. tuttavia i risultati delle sporadiche ricerche fin’ora condotte suggeriscono la possibilità di distinguere i travertini dai calcareous tufa in funzione del loro fabric deposizionale (fig. 7). ne consegue che, adottando criteri che tengano conto dei caratteri tessiturali e geochimici di sedimenti attualmente in formazione, potrà essere effettuata la distinzione genetica dei carbonati continentali antichi. eventuali future ricerche potranno apportare ulteriori integrazioni a questa classificazione. comunque per il momento l’uso comune di una nomenclatura differenziata dei depositi calcarei concrezionari può portare ad una caratterizzazione genetica del litotipo più immediata e quindi fornire informazioni specifiche di tipo geologico e climatico. infatti, a seconda dalla presenza di travertini o calcareous tufa, le informazioni derivanti sono differenti: nella sedimentologia e stratigrafia, dove i calcareous tufa risultano in genere essere tra i migliori recorder di caratteristiche paleoambientali e paleoclimatiche (henning et al., 1983; carrara et al., 1998); nella geologia strutturale, visto che i travertini sono considerati utili indicatori per la comprensione dei processi e della storia neotettonica (minissale, 1991; hancock et al., 1999); nel campo dell’archeologia e antropologia, che utilizzano le informazioni fornite dai calcareous tufa per la ricostruzione dell’impatto umano sul territorio (cilla et al., 1994; goudie et al., 1993; violante & d’argenio, 2000); nel reperimento di materiali ornamentali, nell’archeometria, e nella conservazione dei monumenti lapidei, poiché soprattutto i travertini costituiscono una delle pietre più usate come ornamento o rifinitura nelle 280 e. capezzuoli & a. gandin costruzioni dell’uomo (rodolico, 1965); nella biologia extraterrestre in quanto i travertini sono oggetto privilegiato di investigazione (nasa, 1995; allen et al., 2000; bishop et al., in press) per la ricerca di vita su marte. ringraziamenti: gli autori ringraziano vivamente claudio carrara per le costruttive osservazioni. lavoro eseguito con i fondi della “quota servizi per la ricerca” dell’università di siena (par 2003, a.gandin) lavori citati allen c.c., albert f.g., chafetz h.s., combie j., graham c.r., kieft t.l., kivett s.j., mckay d.s., steele a., tauton a.e., taylor m.r., thomaskeprta k.l & westall f. (2000) microscopic phisical biomarkers in carbonate hot springs: implications in the search for life on mars. icarus, 147, 49-67. altunel e. & hancock l. (1993) morphology and structural setting of quaternary travertines at pamukkale, turkey. geological journal, 28, 335346. andrews j.e., riding r. & dennis p.f. (1997) the stable isotope record of environmental and climatic signals in modern terrestrial microbial carbonates from europe. paleogeography, paleoclimatology, paleoecology, 129, 171-189. barazzuoli p., costantini a., fondi r., gandin a., ghezzo c., lazzarotto a., micheluccini m., salleolini m. & salvadori l. (1988) i travertini di rapolano sotto il profilo geologico e geologicotecnico. in: v.coli. (eds) il travertino di siena. pp. 26-35, al.sa.ba grafiche, siena. bellanca a., bommarito s., neri r., preite martinez m. & turi b. (1991) interpretation of depositional systems forming travertine accumulations in nortwestern sicily, italy: petrographic and geochemical evidence. boll. soc. geol. it., 110, 15-24. berakhi o., brancaccio l., calderoni g., coltorti m., dramis f. & umer m.m. (1998) the mai maikden sedimentary sequence: a reference point for the environmental evolution of the highlands of northern ethiopia. geomorphology, 23, 127-138. bishop j.l., murad e., lane m.d. & mancinelli r l. (in press) multiple tecnique for mineral identification on mars: a study on hydrothermal rocks as potential analogues for astrobiology sites on mars. icarus boni c. & colacicchi r. (1966) i travertini della valle del tronto – giacitura, genesi e cronologia. mem. soc. geol it., 5, 315-339. braithwaite c.j.r. (1979) crystal textures of recent fluvial pisolites and laminated crystalline crusts in dyfed, south wales. journ. of sedimen. petr., 49(1), 181-193. brancaccio l., d’argenio b., ferreri v., preite martinez m., stanzione d. & turi b. (1986) caratteri tessi281 fig. 7 esempi di microfacies: a sinistra lamine stromatolitiche di calcareous tufa – x20, sorgente sospesa (monticiano, siena); a destra crosta cristallina di travertino x10; sistema di piccoli terrazzi (rapolano terme, siena). examples of microfabric: on the left: stromatilithic laminae from calcareous tufa – x20, perched-springline (monticiano, siena); on the right: crystalline crust from travertine x10; terrace complex (rapolano terme, siena). i “travertini” in italia ... turali e geochimica dei travertini di rocchetta a volturo (molise). boll. soc. geol. it., 105, 265-277. buccino g., d'argenio b., ferreri v., brancaccio l., ferreri m., panichi c. & stanzione d. (1978) i travertini della bassa val tanagro (campania): studio geomorfologico, sedimentologico e geochimico. boll. soc. geol. it., 97, 617-646. caboi r., cidu r., fanfani l., zuddas p, & zuddas p.p. (1991) geochemistry of funtana maore travertines (central sardinia, italy). miner. petrogr. acta, 34, 77-93. caputo m.c., quadrato e. & walsh n. (1996) influenza dello shock termico sui parametri fisico-meccanici del “tufo calcareo” del bordo occidentale delle murge. mem. soc. geol. it., 51 (2), 813-822. carrara c. (1994) i travertini di canino (viterbo, italia centrale): elementi di cronolitostratigrafia, di geochimica isotopica e loro significato ambientale e climatico. il quaternario, 7(1), 73-90. carrara c. (1998) i travertini della valle del pescara tra popoli e tor de’passeri (abruzzo, ital ia centrale). il quaternario, 11(2), 163-178. carrara c., ciuffarella l. & paganin g. (1998) inquadramento geomorfologico e climaticoambientale dei travertini di rapolano terme (si). il quaternario, 11(2), 319-329. carrara c., esu d. & ferreli l. (1995) lo sbarramento di travertino delle marmore (bacino di rieti, italia centrale): aspetti geomorfologici, faunistici ed ambientali. il quaternario, 8(1), 111-118. celico p. (1986) prospezioni idrogeologiche. volume primo. liguori editore, napoli, 735 pp. chafetz h.s. & folk r.l. (1984) travertines: depositional morphology and the bacterially constructed costituents. j. sedim. petrol., 54, 289-316. chafetz h.s & guidry s.a. (2003) deposition and diagenesis of mammoth hot springs travertine, yellowstone national park, wyoming, u.s.a. can. j. earth sci., 40, 1515-1529. chafetz h.s., rush p.f. & utech n.m. (1991) microenvironmental controls on mineralogy and habit of caco3 precipitates: an example from an active travertine system. sedimentology, 38, 107126. cherubini c., di cuia n., pagliarulo r. & ramunni f.p. (1996) caratteri petrografici e meccanici delle calcareniti di matera. mem. soc. geol. it., 51 (2), 761-769. cilla g., coltorti m. & dramis f. (1994) holocene fluvial dynamics in mountain areas: the case of the river esino (appennino umbro-marchigiano). geogr. fis. dinam. quat., 17, 163-174. cipriani n., ercoli a., malesani p. & vannucci s. (1972) i travertini di rapolano terme (siena). mem. soc. geol. it., 11, 31-46. ciprianii n., malesani p. & vannucci s. (1977) i travertini dell’italia centrale. boll. serv. geol. d’it., 98, 85115. d'argenio b. (2001) from megabanks to travertines – the indipendence of carbonate rock growthforms from scale and organismal templates through time. proceedings of the international school earth and planetary sciences, siena, 109130. d'argenio b. & ferreri v. (1988) ambienti deposizionali e litofacies dei travertini quaternari dell’italia centtro-meridionale. mem. soc. geol. it., 41, 861868. d'argenio b., ferreri v., stanzione d., brancaccio l. & ferreri m. (1983) i travertini di pontecagnano (campania): geomorfologia, sedimentologia, geochimica. boll. soc. geol. it., 102, 123-136. demicco r.v. & hardie l.a. (1994) sedimentary structures and early diagenetic features of shallow marine carbonate deposits. sepm atlas series, 1, 142-158. desio a. (1973) geologia applicata alla ingegneria. hoepli editore, milano, 1192 pp. dramis f., materazzi m. & cilla g. (1999) influence of climatic changes on freshwater travertine deposition: a new hypothesis. phys. chem. earth (a), 24(10), 893-897. emeis k.c., richnow h.h. & kempe s. (1987) travertine formation in plitvice national park, yugoslavia: chemical versus biological control. sedimentology, 34, 595-609. ferreri v. (1985) criteri di analisi di facies e classificazione dei travertini pleistocenici dell’ ital ia meridionale. rend. acc. scienze fis. e mat., 52, napoli. 47 pp. fioraso g. (1999) i travertini della valle di susa e della val chisone (provincia di torino): caratterizzazione sedimentologica, morfologica e ipotesi genetiche. il quaternario, 12(2), 261-274. folk r. (1994) interaction between bacteria, nannobacteria, and mineral precipitation in hot spring of central italy. geogr. phis. et quaternaire, 48(3), 233-246. folk r., chafetz h.s. & tiezzi p.a. (1985) bizarre forms of depositional and diagenetic calcite in hot-spring travertines, central italy. in schneidermann n. & harris p. (eds) the biology of blue-green algae. oxford, blackwell scientific publication, 434-472. ford t. d. & pedley h.m. (1996) a review of tufa and travertine deposits of the world. earth sci. rev., 41, 117-175. foucault a. & raoult j.f. (1986) dizionario di scienze della terra. masson iatlia editori, 350 pp. fouke b.w., farmer j.d., des marais d.j., pratt l., sturchio n.c., burns p.c. & discipulo m.k. (2000) depositional facies and acqueous-solid geochemestry of travertine-depositing hot spring (angel terrace, mammoth hot spring, yellostone national park, u.s.a.). journal of sedimentary research, 70(3), 565-585. fritz p. (1965) composizione isotopica dell’ossigeno e del carbonio nei travertini della toscana. boll. geofis. teor. applic., 7, pp. 25. gandin a, capezzuoli e. & sandrelli f. (2002) a messinian hot-spring travertine system and its modern analogue at rapolano in southern tuscany, italy. 16th international congress iugs, johannesburgh (south africa), abstracts volume, pag. 110. glover c. & robertson a.h.f. (2003) origin of tufa (cool-water carbonate) and related terraces in the antalya area, sw turkey. geological journal, 38, 329-358. golubic s., violante c., ferreri v. & d'argenio b. 282 e. capezzuoli & a. gandin (1993) algal control and early diagenesis in quaternari formation (rocchetta a volturno, central apennines). boll. soc. paleont. ital., spec vol. 1, studies on fossil benthic algae. f. barattolo et al. (eds), 231-247, mucchi, modena. gonfiantini r., panichi c. & tongiorgi e. (1968) isotopic disequilibrium in travertine deposition. earth and planetary sc. lett., 5, 55-58. goudie a.s., viles h.a. & pentecost a. (1993) the lateholocene tufa decline in europe. the holocene, 3(2), 181-186. guo l., andrews j., riding r., dennis p. & dresser d. (1996) possible microbial effects on stable carbon isotopes in hot-spring travertines. jour. sed. research, 66, 468-473. guo l. & riding r. (1992) micritic aragonite laminae in hot water travertine crust, rapolano terme. sedimentology, 39, 1067-1079. guo l. & riding r. (1994) origin and diagenesis of quaternary travertine shrub facies, rapolano terme, central italy. sedimentology, 41, 499-520. guo l. & riding r. (1998) hot-spring travertine facies and sequences, late pleistocene, rapolano terme, italy. sedimentology, 45, 163-180. guo l. & riding r. (1999) rapid facies change in holocene fissure ridge hot spring travertines, rapolano terme, italy. sedimentology, 46, 11451158. geurts m.a. (1976) formation de travertins postglaciaries en belgique. in: t. vogt (editor): colloque types de croũtes et leur répartition regionale, strasbourg 9-11 janier 1975. universitè de louis pasteur, strasbourg, pp. 76-79. hancock p.l., chalmers r.m.l., altunel e. & çakir z. (1999) travitonics: using travertines in active fault studies. journal of structural geology, 21, 903-916. henning g.j., grün r. & brunnacker k. (1983) speleothems, travertines and paleoclimates. quaternary reasearch, 20, 1-29. herman j.s. & lorah m.m. (1987) co2 outgassing and calcite precipitation in falling spring greek, virginia,u.s.a. chemical geology, 62, 251-262. herman j.s. & lorah m.m. (1988) calcite precipitation rates in the field: mesasurement and prediction for a travertine-depositing stream. geochimica et cosmochimica acta, 52, 2347-2355. irion g. & miller g. (1968) mineralogy, petrology and chemical composition of some calcareous tufa from the schwäbische alb, germany. in : müller g. & friedman g.m. (eds): recent developments in carbonate sedimentology in central europe. berlin, springer-verlag, 151-171. julià r. (1983) travertines. in: p.a. scholle, d.g. bebout, c.h. moore (editors): carbonate depositional environments. aapg memoir, 33, 62-72. koban c.g. & schweigert g. (1993) microbial origin of travertine fabrics – two examples from southern germany (pleistocene stuttgart travertines and miocene riedöschingen travertine). facies, 29, 251-264. lang j., pascal a. & salomon j. (1992) caractérisation pétrographique de divers carbonates continentaux holocénes du jura français (arbois, chalain, dortan). implications paléogéographiques. z. geomorph. n.f., 36, 273-291. lovek.m. & chafetz h.s. (1988) diagenesis of laminated travertine crusts, arbuckle mountains, oklahoma. journ. of sedim. petr., 58(3), 441-445. lovek.m. & chafetz h.s. (1990) petrology of quaternary travertine deposits, arbuckle mountains, oklahoma. in: j.s. herman and d.a. hubbard (eds): travertine-marl: stream deposits in virginia. va. div. mineral resour. publ., 101, 6578. manfra l., masi u. & turi b. (1976) la composizione isotopica dei travertini del lazio. geol. rom., 15, 127-174. martìn-algarra a., martìn-martìn m., andreo b., julià r. & gonzales-gòmez c. (2003) sedimentary patterns in perched spring travertines near grenada (spain) as indicators of the paleohydrological and paleoclimatological evolution of a karst massif. sedimentary geology, 161, 217-228. minissale a. (1991) thermal springs in italy: their relation to recent tectonics. applied geochemistry, 6, 201-212. minissale a., kerrick d.m., magro g., murrell m.t., paladini m., rihs s., sturchio n.c., tassi f. & vaselli o. (2002) geochemistry of quaternary travertines in the region north of rome (italy): structural, hydrologic and paleoclimatic implications. earth and pl. sc. letters, 203, 709-728. nasa (1995) an exobiological strategy for mars exploration, sp-530. national aeronautics and space administration, washington, dc. ordon̆z s. & garcia del cura m.a. (1983) recent and tertiary fluvial carbonates in central spain. spec. publs. int. ass. sediment., 6, 485-497. pedley h.m. (1990) classification and environmental models of cool freshwater tufas. sedim. geol., 68, 143-154. pedley m., gonzalès martìn j.a., ordon̆èz delgado s. & garcia del cura m.a. (2003) sedimentology of quaternary perched springline and paludal tufas: criteria for recognition, with examples from guadalajara province, spain. sedimentology, 50, 23-44. pentecost a. (1994) formation of laminate travertines at bagno vignone, italy. geomicrobiology jour., 12, 239-251. pentecost a. (1995) the quaternary travertine deposits of europe and asia minor. quat. sci. rev., 14, 1005-1028. pentecost a., jones b. & renaut r.w. (2003) what is a hot spring? can. j. earth sci., 40, 1443-1446. pentecost a. & lord t. (1988) postglacial tufas and travertines from the craven district of yorkshire. cave sci., 15(1), 15-19. pentecost a. & viles h.a. (1994) a review and reassessment of travertine classification. geogr. phys. et quaternaire, 48, 305-314. pentecost a. & whitton b.a. (2000) limestone. in: whitton b.a. & potts m. (eds), the ecology of cynobacteria . 257-279, kluwer academic publisher, netherland. riding r. (2002) structure and composition of organic 283i “travertini” in italia ... reefs and carbonate mud mounds: concepts and categories. earth-science reviews, 58, 163-231. rodolico f. (1965) le pietre delle città d’italia. ed. le monnier, firenze. symoens j.j., duvigneaud p. & vanden bergen c. (1951) aperçu sur la végétationdes tus calcaires de la belgique. bull. soc. r. bot. belg., 83, 329-352. turi b. (1986) stable isotope geochemestry of travertines. in: p. fritz & j.c. fontes (eds) handbook of environmental isotope geochemestry. 2. terrestrial environment, b. elsevier, amsterdam, pp. 207-238. viles h.a & goudie a.s. (1990) tufas, travertines and allied carbonate deposits. prog. phys. geogr., 14, 19-41. violante c. & d’argenio b. (2000) i travertini alle origini e nel declino dell’antica città di poseidonia – paestum (2500-1000 a. prima del presente). convegno geoben, torino, 7-9 giugno 2000, pp. 8. violante c., ferreri v. & d’argenio b. (1996) modificazioni geomorforfiche controllate dalla deposizione di travertino. il quaternario, 9(1), 213216. violante c., ferreri v., d’argenio b. & golubic s. (1994) – quaternary travertines at rocchetta a volturno (isernia, central italy). facies analysis and sedimentary model of an organogenic carbonate system. i.a.s. 15th reg. meet., april, 1994, ischia, guide book to the field trip, 3-23. 284 ms. ricevuto l’11 maggio 2004 testo definitivo ricevuto il 7 luglio 2004 ms. received: may 11, 2004 final text received: july 7, 2004 e. capezzuoli & a. gandin imp.rosskopf& indagini geoarcheologiche integrate nel molise centrale (italia meridionale): il ponte romano di tufara carmen maria rosskopf 1, gianfranco de benedittis 2 & paolo mauriello1 1 dipartimento di scienze e tecnologie per l’ambiente e il territorio, università degli studi del molise rosskopf@unimol.it; mauriello@unimol.it; 2 facoltà di scienze umane e sociali, università degli studi del molise cfbyad@tin.it riassunto: rosskopf et al., indagini geoarcheologiche integrate nel molise centrale (italia meridionale): il ponte romano di tufara. (it issn 0394-3356, 2007). sebbene il molise si stia rivelando una regione di straordinaria ricchezza archeologica, le conoscenze ad oggi circa la distribuzione spazio-temporale degli insediamenti e delle relative manifestazioni economico-culturali sono del tutto lacunose. ciò pone in chiara luce la difficoltà di mettere i dati archeologici in relazione ai contesti e cambiamenti ambientali, e di valutare l’influenza di questi ultimi sulle vicende umane. il presente lavoro illustra una delle prime esperienze di indagine geoarcheologica integrata effettuate nell’area del molise centrale. tale indagine si è basata su un approccio integrato di analisi archeologiche, geofisiche e geomorfologiche. la struttura che è stata indagata è localizzata nella medio-bassa valle del fiume fortore in località pesco del ponte, comune di tufara (italia meridionale), ed è emersa solo di recente a seguito di un evento alluvionale avvenuto nel gennaio del 2003. si tratta di resti di un ponte che è possibile riferire, in base alla tecnica di lavorazione dei blocchi utilizzati, all’epoca tardo-repubblicana (ii i sec. a.c.). sui resti romani si sovrappongono lacerti in muratura e malta che sono da riferire ad un rifacimento della struttura in epoca medioevale. si tratta di una scoperta molto interessante considerando che l’esistenza di tale ponte è di forte sostegno all’ipotesi, supportata anche da altri dati, della presenza, già in epoca repubblicana, di una strada che attraversava l’alveo del fortore proprio all’altezza del ponte. in base all’analisi delle fonti letterarie e storico-cartografiche, tale strada potrebbe essere stata una delle due principali arterie che trovavano nel centro dell'antico abitato di saepinum il loro punto d'incontro. allo scopo di valutare la prosecuzione nel sottosuolo della stessa struttura del ponte e/o della collegata viabilità sono stati effettuati dei profili geoelettrici dipolari che hanno consentito la restituzione di sezioni di probabilità di occorrenza di anomalie di resistività nel sottosuolo a varie profondità. le anomalie riscontrate indicano chiaramente la presenza nel sottosuolo, a poca profondità, di una struttura che va presumibilmente identificata con la prosecuzione del ponte. le indagini geomorfologiche hanno consentito di evidenziare che la dinamica fluviale ha profondamente influito sulle condizioni di stabilità dell’alveo del fortore in tempi storici attraverso una serie di fenomeni di aggradazione e incisione e conseguenti variazioni altimetriche del fondovalle. in particolare, a partire da un livello del fondovalle posto a ca. 3 m dall’attuale, cui si collega la struttura del ponte romano, si ricostruiscono almeno tre episodi di alluvionamento che hanno portato prima al danneggiamento e poi alla distruzione e al seppellimento del ponte romano e della sovrastante struttura medievale. l’innalzamento complessivo del fondovalle dall’epoca repubblicana a quella medievale è stimabile in ca. 6 m. in sintesi, le indagini geofisiche e geomorfologiche hanno dato un valido contributo alla interpretazione del sito archeologico, le prime andando a costituire la base per eventuali scavi futuri od azioni di recupero, le seconde nel caratterizzare il contesto morfologico e morfodinamico in cui si inseriscono le vicende del ponte di tufara. viceversa, il contesto archeologico locale ha dato un contributo importante all’inquadramento cronologico delle fasi morfoevolutive ricostruite e alle considerazioni sulla possibile influenza esercitata da fattori climatici e antropici. abstract: rosskopf et al., integrated geoarchaeological investigations in the central molise (southern italy): the roman bridge of tufara. (it issn 0394-3356, 2007). although the molise region is being discovered to be of exceptional value as to his archaeological and historical heritage, the frame about the spatial-temporal distribution of settlements and related economical-cultural expressions is full of gaps. this circumstance clearly evidences the difficulties to relate archaeological data to the environmental contexts and changes and to investigate the influence of the latter ones on human events. the present paper illustrates one of the first experiences of geoarchaeological investigation in the central molise area region which is based on an integrated approach of archaeological, geophysical and geomorphologic analyses. the structure which has been investigated is localized in the medium-lower valley of the fortore river in locality pesco del ponte, municipality of tufara (southern italy). at this site, remains of a roman bridge were exposed along the left bank of the fortore river after a flood event in january 2003. said remains consist in a pillar of a bridge which can be dated, on the basis of the technique used for the working of the rock blocks, to the republican age (ii-i centuries bc). superimposed on the roman remains are remnants of a brick work with mortar which indicate a remaking of the bridge in medieval times. the discovery of the roman bridge is very interesting as it documents the presence of a road crossing the fortore river just there. as suggested by the analysis of literature and cartographichistorical documents, that road could be one of the two main ones that met within the centre of the ancient saepinum. it gives further evidence of the strategic role the fortore valley played in historical times as the natural connection between the sannium to the west and the daunia to the east. to evaluate the prosecution of the bridge structure in the sub-soil, electric vertical soundings based on the dipolar method have been carried out. these soundings have allowed the restitution of tomographic sections showing the anomalies in resistivity at different depths. the reconstructed anomalies clearly evidence the presence, at a few meters depth, of a structure which can be most probably identified with the prosecution of the bridge. geomorphologic analyses have allowed us to evidence that fluvial dynamics has greatly influenced the stability of the valley bottom in historical times. a number of important variations in height of the valley floor related to alternating phenomena of valley incision and filling could be reconstructed. particularly, beginning from a valley floor level at about – 3 m from the present one, on which the roman bridge was constructed, at least three events of flooding could be reconstructed which first caused the damaging of the bridge and then the destruction and burial of the roman and the superimposed medieval structure cumulating a valley aggradation of about six meters. in synthesis, the geophysical and geomorphologic analyses have contributed in a significant way to the interpretation of the archaeological site, the first approach by giving valid indications about the probable prosecution of the bridge, useful for future excavation, the second one by allowing to detail the morphologic and dynamic contexts which have characterised the fortore valley floor from roman to late medieval times. on the other hand, the archaeological data have given an essential contribution to define the chronological frame of the reconstructed sequence of events, and therefore also to the investigation into the role of human or climatic factors. parole chiave: geoarcheologia, morfologia e dinamica fluviale, fiume fortore, molise, periodo storico. keywords: geoarchaeology, fluvial morphology and dynamics, fortore river, molise, historical period. il quaternario italian journal of quaternary sciences 19(2), 2006 241-252 242 c.m. rosskopf, g. de benedittis & p. mauriello 1. premessa il molise costituisce una regione di straordinaria ricchezza archeologica ancora poco conosciuta. a prescindere, infatti, da una serie di siti archeologici più noti e studiati (es. il sito paleolitico di isernia la pineta (peretto, 1996) e dalle pur numerose segnalazioni di ritrovamenti, purtroppo spesso non meglio documentati, esiste ad oggi un quadro del tutto lacunoso circa la frequentazione del territorio molisano nelle diverse epoche storiche. a ciò è collegata di conseguenza la difficoltà di ricostruire oltre alle singole vicende e forme insediative i contesti e cambiamenti ambientali in cui queste si inseriscono. il presente lavoro illustra una delle prime esperienze di indagine geoarcheologica integrata effettuata nell’area del molise centrale (fig. 1). oggetto dell’indagine sono i resti di un ponte romano la cui segnalazione è dovuta all’associazione culturale locale a’ ficurell di tufara (provincia di campobasso). lo studio effettuato è stato finalizzato sia ad una migliore conoscenza del sito archeologico in esame sia ad un suo inquadramento ambientale. l’area di indagine ricade nella valle del fiume fortore che nel passato ha goduto di grande importanza, avendo rivestito un carattere strategico specie in epoca preromana per essere il naturale collegamento tra il sannio ad ovest e la daunia ad est. ciò mette inoltre in rilievo, come anche documentato dalle scoperte archeologiche finora effettuate, l’importanza che nel passato hanno assunto gli assi fluviali nel favorire gli spostamenti da e verso la costa adriatica. 2. indagini archeologiche nonostante in questi ultimi anni si siano intensificati gli studi sui ponti presenti nel molise (ambrosetti, 1958; monaco, 1989; galliazzo, 1994; marino, 1996; pelosi & sabelli, 1996; caiazza, 1997; matteini chiari, 1997), c’è ancora molto da fare; ne è una riprova il ponte di recente scoperto in agro di tufara sul fiume fortore, in località pesco del ponte (fig. 2), toponimo a cui in precedenza non era collegato nessun elemento strutturale a vista. la sua acquisizione è recente quanto fortunosa: il ponte è stato infatti messo in luce a seguito di un recente evento alluvionale avvenuto nel gennaio 2003, allorché la piena fluviale ha causato l’erosione della sponda sinistra del fiume fortore fino a far emergere parti di esso. le indagini e le rilevazioni svolte hanno consentito l’identificazione dei materiali costruttivi nella pietra calcarea proveniente da cave dell’alta valle del fortore. le caratteristiche del litotipo sono la grana molto fine, una bassa porosità e una buona resistenza meccanica. l’apparecchio esterno del ponte è caratterizzato da fig. 1 ubicazione dell’area studiata (vedi riquadro) e del ponte romano di tufara. il tratto in grigio rappresenta la viabilità romana ipotizzata che collegava la valle del fortore (con il passaggio sul fiume in corrispondenza del ponte di tufara), attraverso i monti del sannio, con l’antico saepinum. su sfondo grigio vengono evidenziate le antiche città romane collegate o no a tale viabilità. location of the study area (framed area) and the roman bridge of tufara. the grey tract represents the hypothetic roman road which connected the fortore valley (crossing the river at the tufara bridge), through the sannium mountains, with the ancient saepinum. the grey backgrounds evidence the ancient roman towns connected or not to said road. 243indagini geoarcheologiche integrate ... conci perfettamente squadrati e ben rifiniti nelle superfici di contatto, mentre nelle superfici a vista presenta la tecnica del bugnato (fig. 3). e’ evidente l’alternanza di elementi lapidei a grande taglia con altri di altezza minore, ma esuberanti in lunghezza. i blocchi si collocano in corsi differenti e, pur essendo perfettamente riquadrati e tagliati nelle superfici di contatto presentano zeppe disposte regolarmente tra le superfici di contatto. nella parte superiore le murature sono caratterizzate da conci di dimensioni variabili, regolari nel taglio ma non nella lavorazione. le sensibili differenze di materiali e di apparecchio utilizzate lasciano pensare a due fasi costruttive cronologicamente successive più che a rimaneggiamenti. il rilievo (fig. 4) e le indagini in situ non solo hanno messo in luce gli aspetti relativi alla fabbrica (materiali utilizzati, tecniche costruttive, sequenze degli interventi di trasformazione), ma anche alcuni processi di degrado presenti sulle superfici a vista del pilastro dovute al dilavamento delle acque fluviali con conseguente corrosione lineare delle superfici (oggi allisciate) lì dove compare il bugnato e dilatazione in alcuni punti degli spazi tra le superfici di contatto. sulla parte alta dove cambia la tecnica muraria caratterizzata da ampio uso di legante, le disgregazioni e le fratture sono molto evidenti; qui manca traccia del paramento originario. e’ visibile solo parte dei due muri d’accompagnamento disposti obliquamente rispetto al muro di testa con cui le murature non trovano soluzione di continuità; il muro di testa presenta una cornice d’imposta continua formata da grossi blocchi con aggetto a gola dritta su cui si sovrappone un ampio listello appena sporgente e con superficie ruvida; la sporgenza non trova continuità nei muri d’ala dove la cornice scompare, ma non il blocco su cui si dispone, che continua anche nel muro d’ala. sulla faccia superiore del muro d’ala di sinistra compare un tratto di blocchi allineati che sembra separarla dalla muratura del muro di testa; ciò lascia presumere una diversa fase costruttiva dei due corpi; i muri d’accompagno che correvano lungo la sponda del fiume sono tuttavia in parte ancora coperti da sedimenti fluviali; ciò non consente una lettura più complefig. 2 stralcio topografico semplificato del tratto di fondovalle studiato (tratto dalla tavoletta i.g.m.i. volturara appula (f. 163, iii no) in scala 1:25.000). topographic simplified sheet of the studied valley floor sector (drawn from i.g.m.i. topographic sheet volturara appula (f. 163, iii no) in scale 1:25.000). fig. 3 il ponte di tufara appena esposto a seguito dell’alluvione del gennaio 2003. la freccia indica un frammento di muratura della struttura medievale. a view of the roman bridge of tufara immediately after the flood event in january 2003. the arrow indicates a fragment of the walling of the medieval bridge structure. 244 ta. il pilone è costruito con grossi conci squadrati e con faccia vista bugnata, tecnica che compare nei ponti romani prevalentemente di epoca tardo-repubblicana (ii-i sec. a.c.); della struttura resta un’ampia cornice d’imposta che separa il pilone dall’arcata, di cui r imane solo qualche traccia; il muro di testa misura 4,4 m, corrispondenti a 15 piedi romani; non è possibile recuperare altre dimensioni uti l i in quanto buona parte della struttura è coperta dal limo fluviale, ma la posizione della cornice d’imposta lascia presumere che la parete sia molto più alta di quanto emerge dal fondo fluviale (1,5 m compresa la cornice). nel terreno circostante sono stati rinvenuti frammenti di pareti relative a vasi a vernice nera cronologicamente riferibili al ii i sec. a.c. per tipo di argilla e vernice. a breve distanza dall’area del ponte, presso lo sbocco del vallone teverone (fig. 2), durante i lavori agricoli è stata trovata una tomba di epoca ellenistica; del corredo si è salvata una coppa a vernice nera quasi integra, risalente alla fine del iv – inizio iii sec. a.c. sul versante destro del fiume, sulla collina che affaccia sul ponte, è inoltre da ricordare la presenza di una villa romana attestata non solo da ruderi, ma anche da un tesoretto di monete repubblicane rinvenuto alcuni anni or sono (ceglia, 1984). l’area, dunque, appare frequentata in epoca repubblicana, periodo a cui rimanderebbe la tecnica di lavorazione dei blocchi utilizzati per la costruzione del ponte di tufara. il ponte permette di ipotizzare, già in epoca repubblicana, la presenza di una strada di cui non avevamo alcun dato, almeno apparentemente. in effetti, la rilettura della principale fonte cartografica per conoscere la viabilità romana, la tabula peutingeriana (copiata nel xii-xiii secolo ad da un originale del iv secolo d.c., e giunta a noi attraverso varie edizioni fino a quella più moderna di weber (1976) cui si fa riferimento per il presente lavoro), propone una strana descrizione: lì dove compare il toponimo hercul' rani, (segmento vi, 3), c’è anche un castelletto (in genere indicativo di un municipium) in cui viene riconosciuta aecas, città romana corrispondente all'attuale troia. la rappresentazione grafica, considerando che ci troviamo di fronte ad una copia medioevale di un originale romano, potrebbe permetterci di ipotizzare che il copista abbia erroneamente sovrapposto due tratti indicanti due vie romane diverse. la lettura della tabula peutingeriana consente quindi, anche se con la dovuta cautela, di ipotizzare l’esistenza di una strada di cui farebbe parte il nostro ponte romano (fig. 1); considerando che la tabula peutingeriana è datata al iv sec. d.c, è da presumere che il ponte sia stato utilizzato per tutta la fase imperiale. oltre ai dati strutturali, sull’esistenza del ponte in epoca medioevale, sono da ricordare una serie di altre fonti storiche: • tra i documenti conservati nell'archivio di monte cassino (dell’olmo, 2000) ve ne sono tre che si riferiscono a tre diverse donazioni di chiese fatte da nobilone, conte del castello di vipera, i cui resti sopravvivono sulla cima omonima posta tra gambatesa e tufara, paese quest’ultimo (fig. 1) nel cui territorio ricade il nostro ponte. nel primo documento, datato al 1070 (bloch, 1989; dell’olmo, 2000) tra gli elementi utilizzati per individuare i limiti del territorio donato si parla di una via beneventana, denominazione a noi nota, ma riferita ad un altro tratto di strada che, partendo dall'antica città romana di saepinum, portava a benevento (cuozzo & marten, 1998). l'identità di denominazione fa presupporre che in epoca medioevale lungo la valle del torrente tappino (uno dei principali tributari sinistri del fiume fortore, fig. 1) passasse un'arteria viaria che, provenendo da benevento e passando per saepinum, giungesse al fiume fortore. • in un documento del xiii secolo che riguarda jelsi, paese posto a breve distanza da tufara e ubicato nella valle del torrente tappino, si parla ancora di una via publica che passa per la località pantaneto, forse presso la località cantalupo (amelli, 1903). • il percorso sul versante meridionale è denominato via di s. angelo in un testo della metà del xiii secolo (amelli, 1903), denominazione che fa riferimento alla chiesa di s. angelo posta su un rilievo collinare (m. s. angelo, fig. 1) in destra del fortore di fronte al ponte. • sulla via in terra battuta ai margini della quale è la chiesa di s. angelo, in direzione di s. bartolomeo in galdo (fig. 1), c’è un’iscrizione posta su una roccia che si erge a metà percorso denominata pietra cruciata, su cui sono incise le lettere r(egio) b(raccio) s(an) b(artolomeo) su due linee; la forma delle lettere permette di far risalire l’iscrizione a non oltre il xvii secolo e documenta la presenza di un braccio tratturale diversamente a noi sconosciuto. • il ponte di tufara è inoltre ricordato il 30 giugno 1440 quale spettatore di un conflitto tra aragonesi e angioni (di costanzo, 1735; masciotta, 1915). fig. 4 il ponte di tufara: rilievo delle emergenze. a view of the structural features of the tufara bridge. c.m. rosskopf, g. de benedittis & p. mauriello 245 i dati elencati ci consentono di parlare della presenza del ponte ancora in epoca medioevale tra il 1070 ed il 1440; per il periodo successivo non compaiono altre notizie se non il suo ricordo nel toponimo pesco del ponte, conservato da uno spuntone di roccia posto a poca distanza dai ruderi. 3. indagini geofisiche le prospezioni geofisiche nella zona del ponte romano di tufara sono state condotte nell’ambito delle attività del corso di laurea in scienze dei beni culturali ed ambientali dell’università degli studi del molise. l’esigenza era quella di ottenere indicazioni sulla struttura del sottosuolo fino alla profondità di diversi metri. avendo i terreni superficiali dell’area in esame conducibilità elettriche relativamente elevate è stata scartata l’ipotesi di effettuare indagini georadar che non sono in grado di fornire un’adeguata profondità di investigazione. si è quindi scelto di procedere con una serie di prospezioni geoelettriche che, pur essendo in generale meno speditive, hanno una profondità di investigazione notevolmente superiore (mauriello, 2002). il metodo geoelettrico consiste nella determinazione sperimentale della distribuzione di resistività caratterizzante la struttura elettrica del sottosuolo. il principio fisico del metodo è il seguente: una corrente elettrica è inviata nel sottosuolo tramite una coppia di elettrodi (elettrodi energizzanti) e la risultante distribuzione di potenziale elettrico indotto è determinata tramite un’altra coppia di elettrodi (elettrodi riceventi) connessi ad un voltmetro. ogni disomogeneità presente nel sottosuolo, e per disomogeneità s’intendono corpi a diversa capacità di conduzione elettrica, viene rilevata dal fatto che essa deflette le linee di corrente e distorce pertanto la normale distribuzione di potenziale elettrico. in definitiva, misurando la caduta di potenziale su due punti arbitrari, si è in grado di determinare la resistività elettrica del sottosuolo moltiplicando il rapporto tra la caduta di potenziale e la corrente inviata per un coefficiente geometrico dipendente dalla disposizione degli elettrodi sul terreno. variando la posizione del dispositivo elettrodico sull’area da investigare si ottiene la determinazione della distribuzione di resistività nel volume interessato dalla circolazione di corrente elettrica. come già accennato, in generale la prospezione geoelettrica è meno speditiva di quella georadar e magnetometrica ma possiede, oltre ad una maggiore profondità di investigazione, anche un’affidabilità del risultato notevolmente superiore in qualsiasi condizione logistica del terreno. per ovviare al problema della limitata velocità di acquisizione, nella prospezione in esame è stato adoperato un sistema di acquisizione dei dati interamente progettato all’interno dell’università del molise e dell’istituto per le tecnologie applicate ai beni culturali del cnr di roma. il sistema è composto da: 1) un generatore di onde quadre a frequenza di 33hz (in modo da evitare qualunque disturbo dovuto alle linee elettriche e di ottenere tempi di misura rapidissimi); 2) un ricevitore di segnali con integrati un filtro passabanda e una scheda di acquisizione ed elaborazione; 3) un dispositivo di trasmissione tramite radio-modem dei segnali di controllo tra ricevitore e generatore: ciò ha permesso di eliminare qualsiasi tipo di cavo tra le due unità rendendo il sistema di acquisizione estremamente compatto e maneggevole. per ottenere informazioni più rigorose sulle reali ubicazioni delle anomalie riscontrate, i dati sono stati sottoposti ad una procedura di inversione tomografica 3d (mauriello & patella, 1999) con il risultato finale della restituzione di sezioni reali di probabilità di occorrenza di anomalie di resistività nel sottosuolo. queste rappresentano la probabilità che in ogni punto del sottosuolo esista un’anomalia di resistività rispetto al modello di riferimento che genera l’intero set di dati misurati. nelle sezioni orizzontali estratte a varie profondità valori positivi più alti sono relativi a zone con alta probabilità di presenza di anomalie positive di resistività rispetto al modello medio di riferimento, mentre, al contrario, valori negativi sono relativi a zone con alta probabilità di presenza di anomalie negative di resistività. i risultati delle indagini geoelettriche eseguite presso il ponte di tufara sono illustrati in figura 5 dove fig. 5 tomografie di resistività alle profondità di 1, 2 e 3 metri dal piano campagna. tomographic resistivity slices at depths of 1,2 and 3 meters below the topographic surface. indagini geoarcheologiche integrate ... 246 sono riportate tre sezioni orizzontali di probabilità di occorrenza di anomalie di resistività. le zone a più alta resistività, caratterizzate cioè da colori verso il rosso, sono quelle in cui è più alta la probabilità di trovare anomalie rilevanti, correlabili quindi a strutture di attraversamento o a resti di tracciati viari. in conclusione, le sezioni tomografiche, riportate in coordinate chilometriche (sistema gauss-boaga), mostrano chiaramente, soprattutto nella sezione relativa alla profondità di 1 m, la presenza nel sottosuolo di una struttura che va presumibilmente identificata con la prosecuzione del ponte. 4. indagini geomorfologiche le indagini geologico-geomorfologiche sono state estese ad un piccolo tratto del fondovalle attuale del fiume fortore, lungo ca. 3 km, al cui interno si situano ad una quota di 235 m s.l.m. i resti del ponte romano, e alle superfici terrazzate sospese fino ad un massimo di poco più di 20 m sul fondovalle attuale. il tratto di fondovalle in esame è caratterizzato da una morfologia tipicamente piatta, legata alla sua origine aggradazionale. esso presenta una larghezza piuttosto ridotta di ca. 300 m in corrispondenza del ponte romano, per poi allargarsi progressivamente fino a raggiungere ca. 900 m presso la confluenza del torrente teverone, posta 2 km più a valle. lungo i fianchi vallivi affiorano in prevalenza terreni argillosi (vezzani et al., 2004) riferibili rispettivamente alla formazione delle argille del f. fortore di età messiniana ed alle argille scagliose (cretacico superiore miocene inferiore). quest’ultime, ben note in letteratura come argille varicolori (melidoro, 1971), sono riportate con la sigla av nel foglio n. 162 della carta geologica d’italia. subordinatamente sono presenti, inoltre, terreni a prevalente componente sabbioso-arenacea riferibili alla formazione delle sabbie di valli (vezzani et al., 2004), mentre terreni calcarei affiorano soltanto nelle porzioni alte del bacino del fortore. i depositi quaternari affioranti nell’area di studio sono costituiti in prevalenza da depositi fluviali, e localmente da depositi colluviali e cumuli di frana. i primi sono presenti sia nell’area del fondovalle attuale, sia in corrispondenza delle superfici terrazzate (vedi oltre) presenti ai suoi lati, e sono rappresentati da ghiaie, generalmente di dimensioni da centimetriche a decimetriche, sabbie e limi. lungo i bordi del fondovalle attuale si rinvengono dei cumuli di frana derivanti da fenomeni semplici (scivolamenti e colamenti) o complessi (soprattutto del tipo scivolamento-colata) che hanno interessato in prevalenza la formazione delle argille scagliose. una visione molto schematica, prospettica, della morfologia del tratto vallivo in esame è illustrata in figura 6 che mette in evidenza le posizioni occupate dall’alveo e dalla piana alluvionale del fortore in vari momenti della sua evoluzione più recente, evidenziate da diversi ordini di superfici terrazzate (i, ii, vi, vii e viii) poste a varie quote sull’alveo attuale del fiume (ix). nell’area di studio non si rinvengono lembi di terrazzi fluviali sospesi oltre 5 m sulla quota del fondovalle attuale, ma soltanto lembi di corpi di conoide. ciò probabilmente è dovuto, da un lato, alla elevata instabilità dei fianchi vallivi, impostati in prevalenza su terreni argillosi, e alla conseguente diffusa presenza di fenomeni franosi anche di grandi estensioni, e dall’altro anche alla durata piuttosto limitata delle soste del fiume a determinate quote nel corso dell’approfondimento dell’incisione valliva. le superfici terrazzate rinvenute a quote più elevate (per semplificazione indicate come un unico ordine i in figura 6), sospese tra 22 m e 10 m sul livello dell’alveo attuale, costituiscono i resti di diverse generazioni di conoidi. in particolare, allo sbocco del vallone teverone si riconoscono almeno due generazioni, tra loro incastrate. queste conoidi evidenziano importanti fasi di deposizione detritica agli sbocchi dei principali valloni tributari (valloni teverone e canneto) presenti nel tratto di fondovalle in esame, che hanno temporaneamente bilanciato la prevalente tendenza all’incisione del fiume fortore e il conseguente progressivo abbassamento del livello del fondovalle. la loro genesi appare collegabile, in prima ipotesi, considerato anche l’entità del successivo approfondimento del fondovalle, e in analogia a quanto documentato da vari studi per l’italia centro-meridionale, a fasi di deterioramento climatico che hanno caratterizzato il pleistocene superiore in generale e l’ultimo massimo glaciale (lgm, orombelli et al., 2005) in particolare (basso et al., 1996; cinque et al., 1997; coltorti, 1997; scarciglia et al., 2003). allo sbocco del vallone teverone sono stati rilevati (località ischia dei molini, fig. 2), ancora altri lembi di conoide, frontalmente troncati e terrazzati tra 5 e 10 m sul livello dell’alveo, riferibili ad almeno due ordini. queste conoidi sembrano correlarsi a fasi morfoevolutive molto più recenti, ma la frammentarietà delle evidenze morfologiche non permette di proporre delle correlazioni con i terrazzi alluvionali discussi qui di seguito. in base alla sequenza degli eventi ricostruita, il fondovalle, in un periodo non ben inquadrabile cronologicamente, ma certamente pre-classico (vedi oltre), si era già stabilizzato ad una quota di ca. 5 m sull’alveo attuale (superficie terrazzata di ii ordine, presso masseria colella, figure 6 e 7). tuttavia, non è possibile stabilire, se questa sua posizione altimetrica fosse semplicemente il risultato di una fase di stasi dell’approfonfig. 6 rappresentazione schematica della morfologia del fondovalle del fortore nell’area di studio. i, ii, vi, vii, viii: vari ordini di superfici di origine fluviale; ix: l’alveo attuale; 1*: masseria colella. schematic representation of the fortore valley floor morphology in the study area. i, ii, vi, vii, viii: different orders of alluvial surfaces; ix: present river bed; 1*: masseria colella. c.m. rosskopf, g. de benedittis & p. mauriello fig. 8 car a t t e r i s t i c h e delle successioni f luvial i riferibili ai livelli iv-vi affioranti lungo la sponda sinistra del f iume fortore nel tratto a monte del ponte. la linea t r a t t e g g i a t a segna l’orlo superiore della piccola scarpata che separa le superfici terrazzate di i i e vi ordine. features of the fluvial sequences related to levels iv-vi outcropping along the left bank of the fortore river upstream of the bridge. the dashed line shows the upper edge of the little scarp separating the terrace surfaces of ii and vi order. dimento progressivo del fondovalle, o invece frutto di una temporanea tendenza all’aggradazione. di certo, il fatto che il terrazzo di masseria colella risulti impostato su una successione di ghiaie con clasti poligenici da sub-arrotondati a ben arrotondati e di dimensioni piuttosto omogenee (prevalentemente tra 10 e 20 cm di diametro), immersi in matrice sabbioso-limosa, consente di escludere fenomeni di aggradazione del tutto locali, come quelli causati da fenomeni di sbarramento della valle per frana. in un momento successivo avviene una ripresa della tendenza all’incisione del fondovalle, che porta ad una cambiamento significativo della sua morfologia ed alla situazione topografica in cui trova collocazione la struttura del ponte romano. questa fase di incisione (ed eventuale successivo alluvionamento?) porta l’alveo a stabilirsi, prima del ii secolo a.c., ad una quota di almeno 3 m rispetto al suo livello attuale (superficie di iii ordine, fig. 7), causando il terrazzamento della superficie di ii ordine. questa fase di terrazzamento, come testimonia il ritrovamento sul terrazzo di masseria colella di resti di ceramica riferibile a fine iv – inizio iii secolo a.c., è databile almeno all’inizio dell’epoca ellenistica. dopo la costruzione del ponte romano il fondovalle del fortore è interessato da una fase di aggradazione che causa l’innalzamento dell’alveo di ca. 3 m (superficie di iv ordine, figure 7 e 8) e il danneggiamento del ponte che viene parzialmente seppell ito da un deposito ghiaioso, costituito da clasti poligenici di dimensioni generalmente entro il decimetro immersi in matrice sabbioso-limosa, che chiude verso l’alto con uno strato spesso pochi decimetri di limo argilloso debolmente pedogenizzato (fig. 9). questa fase di aggradazione, in base ai dati archeologici precedentemente esposti, è inquadrabile nella seconda metà del i millennio d.c. il ponte, dopo il suo rifacimento in epoca medioevale intorno all’anno mille, come testimoniato dalla tecnica di costruzione impiegata e dalle più antiche citazioni in letteratura, è soggetto ad almeno due episodi alluvionali, ben documentati dai depositi ghiaioso-sabbiosi e limosi esposti lungo la sponda sinistra intorno al 247 fig. 7 profilo trasversale schematico del fondovalle del fiume fortore all’altezza del ponte romano. a) i: superfici di conoide di i ordine; ii-viii: livelli occupati dal fiume nel corso della sua evoluzione storica; ix: livello dell’attuale alveo. b) schema di dettaglio della sponda sinistra che evidenzia i vari livelli occupati dal fiume e il loro rapporto con la struttura del ponte romano. schematic cross profile of the fortore valley floor at the height of the roman bridge. a) i: first order alluvial fan surfaces; ii-viii: successive levels occupied by the river bed during his historical evolution; ix: level of the present river bed. b) detailed scheme of the left river bank showing the different levels occupied by the river and their relation to the structure of the roman bridge. indagini geoarcheologiche integrate ... sito archeologico (figure 8 e 9). in seguito al primo episodio il letto del fiume si innalza fino a raggiungere la struttura medioevale (superficie di v ordine, figure 7 e 8). in seguito ad una seconda fase di alluvionamento durante la quale l’alveo si porta a ca. 2/2,5 m sul suo livello attuale (superficie di vi ordine, figure 7 e 8), avviene la definitiva distruzione – si nota a riguardo la presenza subito a monte del ponte di un grosso frammento di muratura che si appoggia sulla superficie di v ordine (figure 3 e 7b) e il seppellimento del ponte. la superficie di vi ordine rimane separata morfologicamente da quella di ii ordine da una piccola scarpata lineare, alta ca. 1 m, che si segue anche lateralmente per ca. 300 m (fig. 8). questo secondo episodio alluvionale, responsabile della definitiva interruzione della viabilità, può essere inquadrato tra il 1440 e il 1700 ad, in base alle citate fonti letterarie che fanno menzione del ponte e al rinvenimento di frammenti ceramici di epoca rinascimentale sulla superficie di vi ordine. entrambi gli episodi di alluvionamento appena descritti sono quindi inquadrabili tra il 1440 e il 1700 ad ed hanno comportato nell’insieme un importante innalzamento di ca. 3 m del fondovalle. circa l’evoluzione più recente del fondovalle è possibile evidenziare un leggero abbassamento, avvenuto in più fasi, dell’alveo fluviale (figure 6 e 7a), testimoniato dai livelli vii, viii (rappresentanti rispettivamente la piana alluvionale e l’alveo del 1954) e dal livello ix (l’alveo attuale). attualmente, il fondovalle si presenta sostanzialmente stabile, come evidenzia l’abbassamento molto modesto (di solo 1 m) avvenuto durante gli ultimi 50 anni. tale stabilità è probabilmente imputabile alla presenza dell’invaso artificiale di occhito, posto pochi chilometri più a valle del tratto vallivo studiato, che ha garantito un livello di erosione costante, modulando ed inibendo negli ultimi decenni una possibile tendenza più pronunciata all’incisione del fondovalle. 5. discussione e considerazioni conclusive i dati esposti mostrano che le vicende del ponte di tufara e della collegata viabilità in epoca romana e medioevale si inquadrano in una dinamica ambientale piuttosto complessa. le indagini geomorfologiche, infatti, hanno messo in evidenza che a causa della dinamica fluviale si sono avuti ripetuti spostamenti laterali e variazioni altimetriche dell’alveo del fiume fortore, con un innalzamento di complessivi 6 m circa dall’epoca romana a quella medievale. le variazioni plano-altimetriche registrate, imputabili a fenomeni alternati di aggradazione e di incisione fluviale, non solo hanno portato a cambiamenti talora radicali nella fisionomia del fondovalle, ma soprattutto hanno variamente condizionato la percorribilità e la stabilità delle vie di attraversamento fluviale in generale e del ponte di tufara in particolare. circa il ruolo dei fattori climatici e/o antropici nel determinare le riscontrate variazioni altimetriche del fondovalle, lo studio condotto, anche per il suo carattere locale, non consente di giungere a conclusioni definitive. tenendo conto della localizzazione dell’area di studio e del periodo indagato, è possibile escludere una diretta influenza di eventuali variazioni glacio-eustatiche tardo-oloceniche del livello del mare sulla tendenza all’aggradazione o incisione del corso d’acqua. appare perciò lecito porre suddette variazioni innanzitutto in relazione a minori o maggiori apporti detritici all’alveo e/o portate liquide del fortore, che hanno influito sulla capacità di trasporto e di erosione del fiume. riesaminando nell’insieme i dati acquisiti, è possibile individuare varie fasi di instabilità del fondovalle del fortore nel periodo storico, determinate alternativamente dalla sua tendenza prevalente all’approfondimento o all’aggradazione. sinteticamente, le fasi evolutive distinte fanno riferimento ai seguenti periodi, che in base ai dati cronologici disponibili sono ovviamente da considerarsi solo di prima approssimazione: fasi di approfondimento: pre-ii secolo a.c.; 1700 (1900?) ad attuale; fasi di aggradazione: seconda metà del i millennio d.c.; post-1440 1700 (1900?) ad; fasi di sostanziale stabilità : ii secolo a.c. – iv/v? secolo d.c.; 1070 1440 ad. la costruzione del ponte romano avviene in un periodo di sostanziale stabilità morfologica del fondovalle che sembra essere perdurato per tutto il periodo tardo-repubblicano (ii-i secolo a.c.) e quello imperiale (i – iv/v? secolo d.c.), e che era presumibilmente collegato solo inizialmente a condizioni climatiche più fredde e/o umide rispetto ad oggi (röthlisberger 1986; furrer et al., 1987; giraudi, 2002). tra le fasi evolutive distinte, quelle di aggradazione meritano una particolare attenzione, perché hanno direttamente influito sulle vicende del ponte di tufara. la prima fase di aggradazione, riferibile alla seconda metà del primo millennio d.c. (500-1000 ad), evidenza condizioni di elevata instabilità morfologica simili a quelle che hanno determinato, nello stesso intervallo di tempo e in aree molto vicine a quella studiata, l’avanzamento del delta del fortore (“seconda fase di delta a cuspide”, gravina et al., 2005) e la fase di aggradazione nella valle del torrente cigno, affluente del fiume biferno, documentata da barker (1995) e datata all’inizio del medioevo (720 ad). questa prima fase di aggradazione si inquadra in un periodo di chiara recrude248 fig. 9 dettaglio della sponda sinistra relativo al riquadro nella figura precedente. detail of the left bank showing the framed area indicated in the previous figure. c.m. rosskopf, g. de benedittis & p. mauriello scenza climatica come indicano soprattutto i dati pollinici, climatici e quelli sugli avanzamenti dei ghiacciai riferiti alle aree alpine europee (orombelli & porter, 1982; röthlisberger, 1986; furrer et al., 1987; grove, 1988; baroni, 2000; cremaschi, 2000, holzhauser et al., 2005), ma anche quelli, per citarne alcuni, sull’innalzamento di livello di alcuni laghi appenninici (giraudi, 2000; 2004) e sull’avanzamento del ghiacciaio del calderone (giraudi, 2002). in ambito mediterraneo questa fase evolutiva si collegherebbe ad un periodo distinto da importanti e talora rapidi fenomeni di alluvionamento. secondo alcuni autori (vita-finzi, 1969; veggiani, 1983; ortolani & pagliuca, 1994; giano & guarino, 1996) questi fenomeni di alluvionamento sarebbero legati a condizioni climatiche più freddo-umide delle attuali, secondo altri (brückner, 1983; abbott & valastro, 1995; barker, 1995; barker & hunt, 1995; coltorti, 1997), invece, gli stessi sarebbero più che altro il risultato di interventi antropici sulle coperture del suolo e, in particolare, di azioni di disboscamento in epoca romana. i numerosi dati climatici a disposizione, tuttavia, suggeriscono almeno una concomitanza tra cause antropiche e climatiche, se non addirittura il prevalere del controllo climatico. sotto una forte influenza climatica si è svolta presumibilmente anche la seconda fase di aggradazione, collocata nel periodo tra il 1440 e 1700 a.d. essa, infatti, va a collegarsi ad un periodo caratterizzato da importanti fasi di recrudescenza climatica, conosciuto come la piccola età glaciale (little ice age = lia), inquadrabile approssimativamente, in ambito alpino ed appenninico, tra il 1400/1500 e 1850 (röthlisberger, 1986; furrer et al., 1987; grove, 1988; baroni, 2000; borsato et al., 2003; strumia, 2005). secondo lo studio recente di matthews & briffa (2005), l’inquadramento cronologico della piccola età glaciale andrebbe esteso, sulla base dell’allora estensione dei ghiacciai nelle alpi europee, al periodo 1300-1950 ad. a sostegno dell’influenza climatica globale anche sull’equil ibrio dei sistemi f luviali si evidenziano (marabini, 2000) gli andamenti simili delle portate dei maggiori fiumi d’europa negli stessi periodi, e la relazione diretta tra variazioni di portata dei corsi d’acqua e pulsazioni climatiche freddo-umide che hanno distinto la piccola età glaciale, portando ad un aumento degli apporti solidi alle foci a all’avanzamento progressivo della costa dell’alto adriatico tra il 1600 e il 1820. vistosi effetti dell’instabilità morfologica che caratterizza la piccola età glaciale si manifestano anche sulla costa molisana e pugliese, dove si registrano importanti apporti detritici da parte dei corsi d’acqua alle foci fluviali ed agli specchi d’acqua costieri. questi apporti detritici causano, tra gli inizi del 1600 e del 1800, una importante progradazione della linea di costa, documentata dall’avanzamento del delta del fortore (“quarta fase di delta a cuspide”, gravina et al., 2005), dall’accrescimento del cordone sabbioso del lago di lesina (gravina et al., 2005) e dalla formazione di stagni costieri nell’area di foce del fiume biferno (magini, 1620). l’esame della cartografia storica (cartografia topografica in scala 1:50.000 i.g.m.i., edizioni 1869/75 e 1906/09) e dei dati da letteratura (aucelli & rosskopf, 2000; aucelli et al., 2004) evidenzia un persistere della tendenza prevalente alla progradazione della costa molisana almeno fino all’inizio del 1900 e di maggiorati apporti detritici alle foci dei fiumi trigno e biferno che sviluppano una caratteristica morfologia di delta a cuspide. importanti fenomeni di alluvionamento nella bassa valle del fiume trigno si registrano ancora tra il 1845 e il 1850 (aucelli & rosskopf, 2000). ciò consente di estendere questo periodo di crisi climatica almeno fino all’inizio del 1900 per il versante adriatico molisano. in sintesi, le indagini geofisiche e geomorfologiche, effettuate sostanzialmente a sostegno dello studio archeologico, hanno dato un valido contributo alla interpretazione del sito archeologico. l’indagine geofisica, in particolare, ha consentito di effettuare una prima previsione circa la possibile prosecuzione della struttura del ponte, e di avere una base conoscitiva per eventuali futuri scavi od interventi di recupero. le indagini geomorfologiche hanno permesso di caratterizzare il contesto morfologico e morfodinamico in cui il ponte e le sue vicende evolutive si inseriscono. d’altro canto, i dati archeologici provenienti dal sito indagato e dalle aree limitrofe hanno fornito un contributo significativo alla ricostruzione delle locali vicende geomorfologiche in epoca storica e della possibile influenza di fattori climatici e antropici. ringraziamenti si ringraziano il dr. enrico di pasquale e antonio grosso, presidente e vicepresidente dell’associazione a’ ficurell di tufara, ai quali è dovuta la segnalazione del ponte, per la gentile ospitalità e il supporto alle indagini in campo. gli autori desiderano inoltre ringraziare i referees per le indicazioni e consigli utili nella revisione del testo. bibliografia abbott j.t. & valastro s. (1995) the holocene alluvial records of the chorai of metapontum, basilicata and croton, calabria, italy in: mediterranean quaternary river environments, edited by lewin j., macklin m.g. & woodward j.c, pp. 195-205. ambrosetti g. (1958) enciclopedia dell’arte antica istituto dell’enciclopedia italiana, roma, 4, 230 p. amelli a. (1903) quaternus de excadenciis et revocatis capitanatae de mandato imperialis maiestatis frederici secondi monte cassino, 118 p. aucelli p.p.c. & rosskopf c. (2000) last century valley floor modifications of the trigno river (s. italy): a preliminary report geogr. fis. dinam. quat., 23 (2), pp. 105-115. aucelli p.p.c., faillace p.i., pellegrino p., rosskopf c.m. & scapillati n. (2004) l’evoluzione recente della costa molisana (italia meridionale) il quaternario, 17 (1), pp. 21-31. barker g.w.w. (1995) a mediterranean valley: landscape archaeology and annales history in the biferno valley leicester university press, london, pp. 62-83. barker g.w. & hunt c.o. (1995) quaternary valley floor erosion and alluviation in the biferno valley, molise, italy: the role of tectonics, sea level change, and human activity in: mediterranean quaternary river environments, edited by lewin 249indagini geoarcheologiche integrate ... j., macklin m.g. & woodward j.c, pp. 145-158. baroni c. (2000) il comportamento dei ghiacciai alpini in risposta alle variazioni climatiche oloceniche in: le fluttuazioni del clima nel corso dell’olocene: stato dell’arte. a cura di f. antonioli. i l quaternario, 13 (1), pp. 100-103. basso c., di nocera s., matano f. & torre m. (1996) evoluzione geomorfologica ed ambientale tra il pleistocene superiore e l’olocene dell’area tra castelbaronia e vallata nell’alta valle del f. ufita (irpinia – italia meridionale) il quaternario, 9 (2), pp. 513-520. bloch h. (1989) monte cassino in the middle ages vol. i-iii, harvard university press, roma, 1530 p. borsato a., cucchi f., frisia s., miorandi r., paladini m., piccini l., potleca m., sauro u., spötl c., tuccimei p., villa i.m. & zini l. (2003) ricostruzione climatica degli ultimi 17.000 da una stalagmite della grotta savi (trieste, italia) studi trent. sci. nat., acta geol., 80, pp. 111-125. brückner h. (1983) holozäne bodenbildungen in den alluvionen süditalienischer flüsse z. geomorph. n.f., suppl.-bd. 48, pp. 99-116. caiazza d. (1997) il territorio tra matese e volturno atti 1° convegno di studi (a cura di d. caiazza) sulla storia delle foranie della diocesi di iserniavenafro, capriati al volturno 18 giugno 1994, castellammare di stabia 1997, pp. 66–104. ceglia v. (1984) il tesoretto di monete repubblicane di tufara soprintendenza archeologica del molise, conoscenze, 1, pp. 59-83. cinque a., aucelli p.p.c., brancaccio l., mele r., milia a., robustelli g., romano p., russo f., santangelo n. & sgambati d. (1997) volcanism, tectonics and recent geomorphological change in the bay of napoli fourth international conference on geomorphology, italy 1997, guide for the excursion, suppl. geogr. fis. dinam. quat., iii, pp. 123141. coltorti m. (1997) human impact on the holocene fluvial and coastal evolution of the marche regione, central italy catena, 30, pp. 311-335. cremaschi m. (2000) l’archeologia per lo studio dell’olocene in: le fluttuazioni del clima nel corso dell’olocene: stato dell’arte. a cura di f. antonioli. il quaternario, 13 (1), pp. 100-103. cuozzo e. & marten j.m. (1998) le pergamene di s. cristina di sepino (1143-1463) école française de rome e facoltà di scienze polit iche dell’università di napoli “federico ii”, roma. dell’omo m. (2000) il registrum di pietro diacono (monte cassino, archivio dell’abbazia, reg. 3), commentario codicologico, paleografico, diplomatico casa m. d’auria editore, monte cassino, vol. i, 224 p., vol. ii, 520 p. di costanzo a. (1735) historia del regno di napoli xx volumi, napoli. furrer g., burga c., gamper m., holzhauser h.p. & maisch m (1987) zur gletscher-, vegetations-, und klimageschichte der schweiz seit der späteiszeit geographica helvetica, 2. galliazzo v. (1994) i ponti romani edizioni canova, treviso, vol. i, 761 p., vol. ii, 447 p. giano s.i. & guarino p.m. (1996) trasformazioni ambientali in età storica del territorio di oria (brindisi) il quaternario, 9 (1), pp. 331-336. giraudi c. (2000) le oscillazioni di livello dei laghi: significato paleoclimatico e metodi di studio in: le fluttuazioni del clima nel corso dell’olocene: stato dell’arte. a cura di f. antonioli. i l quaternario, 13 (1), pp. 110-111. giraudi c. (2002) le oscillazioni del ghiacciaio del calderone (gran sasso d’italia, abruzzo – italia centrale) e le variazioni climatiche degli ultimi 3000 anni il quaternario, 15 (2), pp. 149-154. giraudic. (2004) le oscillazioni di livello del lago di mezzano (talentano – vt): variazioni climatiche e interventi antropici il quaternario, 17 (2/1), pp. 221-230. gravina a., mastronuzzi g. & sansò p. (2005) historical and prehistorical evolution of the fortore river coastal plain and the lesina lake area (southern italy) – méditerranée, 104, n. 1-2, pp. 107-117. grove j.m. (1988) the little ice age – cambridge university press, cambridge, uk, 498 p. holzhauser h., magny m. & zumbühl h.j. (2005) glacier and lake-level variations in west-central europe over the last 3500 years the holocene, 15 (6), pp. 789-801. magini a. (1620) – contado di molise & principato ultra – incisione su rame, bologna. marabini f. (2000) effetti sull’erosione costiera dei fenomeni climatici recenti: l’esempio del litorale nord adriatico in: mare e cambiamenti globali. aspetti scientifici e gestione del territorio (a cura di sergio silenzi). convegno icram, 25/26 febbraio 1999, roma, pp. 119-134. marino l. (a cura di) (1996) monumenti del molise, rilievi e indagini sulle strutture alinea ed., firenze 1996, pp. 73-76. masciotta g. (1915) il molise dalle origini ai nostri giorni napoli, ristampato dalla tipografia lampo, campobasso, 1989. matteini chiari m. (1997) il ponte sul fiume sordo, isernia. la necropoli romana in località quadrella a cura di c. terzani e m. matteini chiari, gangemi editore, roma, pp. 20-25. matthews j.a. & briffa k.r. (2005) the little ice age: re-evaluation of an evolving concept geografiska annaler, 87 (1), pp. 17-36. mauriello p. & patella d. (1999) resistivity anomaly imaging by probability tomography geophysical prospecting, 47, pp. 411-429. mauriello p. (2002) la tomografia geoelettrica nella zona tra il foro e le mura settentrionali in: nuove forme di intervento per lo studio del sito antico di cuma, ed. b. d’agostino, pp. 115-119. melidoro g. (1971) movimenti franosi e zonizzazione del bacino del f iume fortore geol. appl. idrogeol., 6, pp. 17-38. monaco d. (1989) la via latina nel territorio dell’alto volturno almanacco del molise, 2, nocera ed., campobasso, pp. 83-103. orombelli g. & porter s.c. (1982) late holocene fluctuations of brenva glacier geogr. fis. dinam. quat., 5, pp. 13-37. ortolani f. & pagliuca s. (1994) variazioni climatiche e crisi dell’ambiente antropizzato il quaternario 7 (1), pp. 351-356. 250 c.m. rosskopf, g. de benedittis & p. mauriello orombelli g., ravazzi g. & cita m.b. (2005) osservazioni sul significato dei termini lgm (umg), tardoglaciale e postglaciale in ambito globale, italiano ed alpino il quaternario, 18 (2), pp. 147-155. pelosi i. & sabelli r. (1996) il ponte giano camense a isernia in: monumenti del molise. rilievi e indagini sulle strutture (a cura di l. marino). alinea editrice, firenze, pp. 73-76. peretto c. (a cura di) (1996) i reperti paleontologici del giacimento paleolitico di isernia la pineta istituto regionale per gli studi storici del molise “v. cuoco”, cosmo iannone editore, 625 p. röthlisberger f. (1986) 10.000 jahre gletschergeschichte der erde verlag sauerländer, aarau, frankfurt, salzburg. scarciglia f., terribile f., colombo c. & cinque a. (2003) late quaternary climatic changes in northern cilento (southern italy): an integrated geomorphological and paleopedological study quaternary international, 106-107, pp. 141-158. strumia g. (2005) temperature variations of the last 700 years reconstructed from a tree-ring chronology of the central alps natura bresciana, ann. mus. civ. sc. nat. brescia, 34, pp. 41-48. veggiani a. (1983) degrado ambientale e dissesti idrogeologici indotti dal deterioramento climatico nell’alto medioevo in italia. i casi riminesi studi romagnoli, 34, pp. 123-146. vita-finzi c. (1969) the mediterranean valleys: geological changes in historical times cambridge, university press. vezzani l., ghisetti f. & festa a. (2004) carta geologica del molise (alla scala 1:100.000) ed. s.el.ca., firenze. weber e. (1976) (a cura di) tabula peutingeriana. codex vindobonensis 324 graz. 251 ms. ricevuto il 20 febbraio 2006 testo definitivo ricevuto il 31 ottobre 2006 ms. received: february 20, 2006 final text received: october 31, 2006 indagini geoarcheologiche integrate ... imp.carveni& il sollevamento della sicilia orientale e alcune implicazioni sismiche e vulcaniche *pietro carveni 1, santo benfatto 2 & maria salleo puntillo 3 1 università di catania, dipartimento di scienze geologiche, sezione di oceanologia e paleoecologia, corso italia 57, 95129 catania, italia, e-mail: carveni@unict.it 2 geologo, libero professionista, via san marco 91, 95047 – paternò (catania) italia, e-mail: benfatto@geologi.it 3 naturalista, via san marco 91, 95047 – paternò (catania) italia, e-mail: maria.salleo@inwind.it riassunto: carveni p., benfatto s. & salleo puntillo m., il sollevamento della sicilia orientale e alcune implicazioni sismiche e vulcaniche. (it issn 0394-3356, 2007). da rilievi effettuati da satelliti, risulta che nell’ambito di un generale sollevamento della sicilia orientale, il settore grossolanamente triangolare dell’edificio vulcanico etneo delimitato a settentrione dal rift di ne e dalla faglia della pernicana, a sw da un sistema di faglie e fratture eruttive con andamento ad arco compreso tra i crateri sommitali e aci castello (sistema montagnola – mascalucia – aci castello), a oriente dalla linea di costa, è caratterizzato da fenomeni di abbassamento. all’interno di questo settore si trovano importanti sistemi di faglie: 1) il sistema giardini – mascali (ne-sw nne-ssw); 2) il sistema ripa della naca piedimonte (ne-sw); 3) il sistema delle timpe (nnw-sse). le informazioni sinora reperite circa l’attività sismica del sistema giardini – mascali si limitano ad una serie di sismi cui è collegata la genesi e l'evoluzione del vulcano di fango salsa di fondachello; solo un sisma di questo sistema, accaduto il 26 marzo 1847, è stato abbastanza intenso da essere registrato a catania; inoltre a tutt’oggi non sono state trovate prove di risalite magmatiche e conseguenti eruzioni collegabili all’attività di questo sistema. al sistema ripa della naca – piedimonte è da attribuire una serie di scosse sismiche avvertite nel paese di piedimonte subito prima e durante l’eruzione etnea del 1928; lungo una delle faglie di questo sistema (ripa di piscio) si aprirono le bocche dalle quali sgorgò la colata lavica che distrusse il paese di mascali. il sistema delle timpe, la cui attività sismica è stata oggetto di numerose osservazioni ad iniziare dal 1805, è responsabile dei più forti terremoti verificatisi sul versante orientale etneo; alcune risalite magmatiche che hanno dato luogo ad eruzioni in tempi storici sono collegate a questo sistema. sulla base di una rilettura critica della letteratura, cui hanno fatto seguito rilievi geologico-geomorfologici di dettaglio, sono state ricostruite le variazioni relative del livello marino in alcuni siti ubicati lungo la costa; i dati evidenziano movimenti differenziali, con innalzamento tra catania e aci castello e abbassamento tra stazzo e torre archirafi. dei fenomeni di abbassamento è responsabile il sistema delle timpe; l’analisi della sismicità di questo sistema per il periodo 1805-1989 ha fornito tassi di abbassamento lungo i piani di faglia compresi tra 2 e 15 mm/anno; questi risultati sono in accordo con i dati di letteratura relativi alla dinamica del versante orientale etneo, il quale risulta soggetto ad un progressivo scivolamento verso ese tramite lo svincolo costituito dalla faglia della pernicana a settentrione e le faglie del sistema montagnola – mascalucia – aci castello a sw. la coincidenza o la vicinanza temporale tra alcune eruzioni verificatesi sul versante orientale dell’edificio vulcanico ed alcuni movimenti sismici avvenuti lungo alcune faglie, che incidono lo stesso versante, fa ipotizzare un collegamento tra i due fenomeni. abstract: carveni p., benfatto s. & salleo puntillo m., eastern sicily uplift and some seismic and volcanic implications. (it issn 0394-3356, 2007). mt. etna is the largest active volcano in europe; it is formed by products of many eruptive centres, which were active in four periods. volcano building is located along the margin of the two main structural domains of eastern sicily: the apennine-maghrebian chain in the north and the hyblaean foreland in the south; the apennine – maghrebian chain consists of several thrust sheets, made up of structural units derived from different palaeogeographical domains; they were overthrusted upon each other during several tectonic phases from eocene to pleistocene. the hyblaean foreland belongs to the northern part of the africa plate; it is formed by a thick triassic to pleistocene carbonate succession, with several intercalations of basic volcanic rocks. while eastern sicily is interested by a general uplift, a sector of the etna volcanic building is characterized by a lowering; this sector is confined by ne rift and pernicana fault in the north, and by montagnola aci castello fault system in the sw; three other fault systems are included in this area; they are: i) giardini – mascali fault system (ne-sw nne-ssw); ii) ripa della naca piedimonte fault system (ne-sw); iii) timpe fault system (nnw-sse). in historical times, the first of these was active only on 26th march 1847; the second system was strongly active during 1928 etna eruption; many earthquakes happened along the timpe fault system from 1805 to present day; they happened sometimes before, during and/or after volcanic eruptions. uplift movements are recorded along the coast between aci castello in the north and catania in the south; some subsidence evidences are visible between torre archirafi in the north and stazzo port in the south; the eastern slope of volcano building is a high seismic hazard zone, with superficial hypocentre earthquakes. parole chiave: sollevamento regionale, sismicità, vulcanismo, geomorfologia. keywords: : regional uplift, seismicity, volcanism, geomorphology. il quaternario italian journal of quaternary sciences 20(1), 2007 57-66 * lavoro presentato al convegno “il sollevamento quaternario nella penisola italiana e nelle aree limitrofe” (roma, 6-8 febbraio 2006) 58 p. carveni, s. benfatto & m. salleo puntillo 1. introduzione alcuni autori, in base a dati provenienti da rilievi in galleria (puglisi, in platania, 1922), studi vulcanologicostrutturali (kieffer, 1983 a; 1983 b; neri et al., 1991; borgia et al., 1992; lo giudice & rasà, 1992; ferrucci et al., 1993; rasà & azzaro, 1995; rasà et al., 1996; bousquet & lanzafame, 2001; obrizzo et al., 2001; tibaldi & groppelli, 2002; neri et al., 2003), macrosismici (azzaro et al., 1989 a; patanè et al., 1994), di sismotettonica (montalto et al., 1996) e geomorfologici (firth et al., 1996), ipotizzano che parte del fianco orientale dell’edificio vulcanico etneo, in contrasto con un generale fenomeno di sollevamento che riguarda tutta la sicilia, trasli verso il mare jonio; la zona, che parte dai crateri sommitali, è delimitata a settentrione dal rift di ne (fig. 1: rne) e dalla faglia della pernicana (fig. 1: fp), faglia diretta con blocco meridionale abbassato e componente laterale sinistra, e a sw dal sistema montagnola – mascalucia – aci castello (fig. 1: smmac), formato da una serie di faglie con componente laterale destra e fratture eruttive disposte ad arco che scendono dai crateri sommitali fino ad aci castello. il primo autore ad individuare il fenomeno è stato puglisi (in platania, 1922); questi aveva riconosciuto una serie di faglie con direzione generale n-s (sistema di aci sant’antonio, sas in fig. 1), le quali interessano il versante compreso tra aci bonaccorsi (fig. 1: ab) e la falesia di acireale (fig. 1: a); in particolare aveva rilevato, lungo alcune gallerie drenanti, sia il rigetto verticale, sia lo spostamento orizzontale verso oriente; questo fenomeno era stato ipotizzato come reazione di una parte dell’edificio etneo al graduale sollevamento della zona (platania, 1922). kieffer (1983 a; 1983 b) ipotizza scivolamenti gravitativi di parte del versante orientale dell'edificio vulcanico etneo, attribuendone la genesi alla ripetuta intrusione di magma attraverso il rift di ne e un rift meridionale. azzaro et al. (1989 a), analizzando i dati ricavati dallo studio del terremoto di codavolpe (catania) del 29 gennaio 1989, ritengono che l'evento sia stato di natura essenzialmente gravitativa e geneticamente collegato all'instabilità del versante orientale etneo. neri et al. (1991) descrivono una serie di deformazioni osservate sul versante orientale etneo, compatibili con un movimento del versante verso oriente. borgia et al. (1992), in base ai risultati ottenuti da ferrari et al. (1991) dallo studio dei dicchi affioranti nella valle del bove, ipotizzano uno spreading radiale del substrato dell'etna verso se. lo giudice & rasà (1992) ritengono invece che si tratti di movimenti puramente gravitativi, che provocano lo scivolamento verso sse della porzione dell'edificio etneo delimitata a settentrione dalla faglia della pernicana e dal rift di ne, e a se dalle faglie di mascalucia e trecastagni. ferrucci et al. (1993), rasà & azzaro (1995) e rasà et al. (1996), in contrasto con borgia et al. (1992) ritengono che solo la porzione del versante orientale etneo, delimitata a settentrione dal rift di ne e dalla faglia della pernicana, e a se dalle faglie di mascalucia e trecastagni, subisca un movimento verso oriente; la causa sarebbe da attribuire a movimenti gravitativi, condizionati da una vasta e profonda superficie di distacco. patanè et al. (1994) ipotizzano che lo spreading gravitazionale verso oriente del settore orientale dell'edificio etneo abbia influenza sul fagliamento superficiale. firth et al. (1996) attribuiscono l'instabilità del versante orientale etneo ad un sollevamento in blocco di tutta la parte nord-orientale della sicilia, cui hanno fatto seguito movimenti superficiali del versante, su un basamento sub-vulcanico che ha subito un sollevamento regionale. montalto et al. (1996), esaminando la sismicità recente dell'etna (dall'aprile 1989 al dicembre 1991), ipotizzano che lo scivolamento del versante orientale etneo riguardi una serie di blocchi che si muovono singolarmente. secondo bousquet & lanzafame (2001) le intrusioni magmatiche che danno luogo alle eruzioni sommitali causano uno spostamento verso oriente solo della parte sommitale del vulcano. obrizzo et al. (2001), esaminando gli effetti cosismici registrati lungo la faglia della pernicana nell'arco di 17 anni, giungono alla conclusione che il versante orientale etneo scivola verso il mare, a causa dell'azione combinata dell'accelerazione di gravità e delle intrusioni magmatiche; la faglia della pernicana rappresenterebbe il limite settentrionale della zona in movimento. secondo tibaldi & groppelli (2002) il movimento traslativo del versante orientale dell'etna verso il bacino ionico sarebbe dovuto a due distinte cause: in profondità le intrusioni magmatiche provocherebbero lo slittamento dei terreni appartenenti all'orogene appenninico – maghrebide sul sottostante plateau ibleo, mentre in superficie il movimento sarebbe di origine prevalentemente gravitativo e localizzato lungo il contatto tra le argille pleistoceniche del basamento etneo e i terreni sottostanti. neri et al. (2003), monitorando i movimenti avvenuti durante l'eruzione etnea 2002 – 2003 lungo la faglia della pernicana, il sistema di faglie delle timpe e la faglia di trecastagni, ipotizzano che il versante orientale etneo sia stato interessato dal movimento verso lo jonio di una massa con volume superiore a 1.100 chilometri cubi; il movimento non sarebbe avvenuto interessando un unico blocco, ma due distinte zone del fianco orientale etneo. 2. inquadramento geologico-strutturale i domini strutturali del bacino del mediterraneo centrale, nel quale si inserisce la sicilia, sono geneticamente collegati alla collisione tra la placca africana e la placca europea; le due masse continentali si scontrano e si saldano tra loro, originando l’orogene appenninico – maghrebide, una catena corrugata che forma la dorsale appenninica e, attraversando l’arco calabro, la sicilia e lo stretto di sicilia, prosegue lungo le coste nord-africane del maghreb. nella zona orientale della sicilia la crosta oceanica ionica e la crosta continentale dell’avampaese ibleo si immergono sotto il fronte dell’orogene appenninicomaghrebide (finetti et al, 1996) (fig. 2). le falde neogeniche dell’orogene appenninico maghrebide sovrascorrono sull’avampaese ibleo, zona fig. 1 schema tettonico del versante orientale etneo (da carveni et al., 2005 a). a) principali sistemi di faglie: sgm) sistema giardini – mascali: fcm) faglia capo schisò – foce del torrente macchia; ff) faglia di fondachello; fg) faglia di giardini; fn) faglia di naxos. smmac) sistema montagnola – mascalucia – aci castello: fma) faglia di mascalucia; ft) faglia di trecastagni; srmp) sistema ripa della naca – piedimonte: frn) faglia della ripa della naca; frp) faglia della ripa di piscio; sas) sistema di sant'antonio; st) sistema delle timpe: fm) faglia di moscarello; fms) faglia macchia – stazzo; fsl) faglia di san leonardello; b) centri abitati: a) acireale; ab) aci bonaccorsi; ac) aci catena; as) aci sant'antonio; fi) fiumefreddo; fm) fondo macchia; fo) fondachello; g) giardini; gi) giarre; m) mascalucia; ma) mascali; s) stazzo; sa) sant'alfio; sg) san giovanni montebello; cma) contrada monti arsi; t) trecastagni; ta) torre archirafi; c) centri eruttivi: cc) cratere centrale; cu) cono di cenere di contrada cutula. i triangoli indicano zone in cui sono stati misurati sollevamenti e abbassamenti fino a 15 mm/anno (gironi et al., 2003). tectonic scheme of mount etna volcano eastern slope (after carveni et al., 2005 a); a) main fault systems: sgm) giardini – mascali fault system: fcm) cape schisò – macchia stream mouth fault; ff) fondachello fault; fg) giardini fault; fn) naxos fault; smmac) montagnola – mascalucia – aci castello fault system: fma) mascalucia fault; ft) trecastagni fault; srmp) ripa della naca – piedimonte fault system: frn) ripa della naca fault; frp) ripa di piscio fault; sas) sant'antonio fault system; st) timpe fault system: fm) moscarello fault; fms) macchia – stazzo fault; fsl) san leonardello fault; b) towns: a) acireale; ab) aci bonaccorsi; ac) aci catena; as) aci sant'antonio; fi) fiumefreddo; fm) fondo macchia; fo) fondachello; g) giardini; gi) giarre; m) mascalucia; ma) mascali; s) stazzo; sa) sant'alfio; sg) san giovanni montebello; cma) contrada monti arsi; t) trecastagni; ta) torre archirafi; c) eruptive centres: cc) central crater; cu) contrada cutula cinder cone. triangles indicate uplift or lowering zones up to 15 mm/y (after gironi et al., 2003). 60 stabile facente parte del margine della placca africana (burollet et al., 1978); esso è costituito da una potente successione prevalentemente carbonatica compresa, con lacune stratigrafiche, tra il trias e il pleistocene medio; vi si intercalano prodotti effusivi basici cretacei, miocenici e plio-pleistocenici, la cui risalita è stata favorita da intense fasi tettoniche distensive (cristofolini, 1966; di grande, 1967; 1969; 1972; carbone et al., 1987; amore et al., 1988; carveni et al., 1991 a; 1991 b; 1993; carveni & sturiale, 1999). l’avampaese ibleo confina ad oriente con la crosta oceanica del bacino ionico (finetti, 1982) tramite la scarpata ibleo maltese, la quale è l’espressione morfologica di un sistema di faglie normali a gradinata, il cui prolungamento verso settentrione interseca il fianco orientale dell’edificio vulcanico etneo (cristofolini et al., 1979). la scarpata si è formata in un’unica grande fase tortoniana, con minori riattivazioni posteriormente al deposito dei trubi (pliocene inferiore), e a luoghi le sono connesse importanti attività vulcaniche (casero et al., 1984). lanzafame & bousquet (1997) ritengono che la scarpata ibleo maltese sia un segmento di un importante sistema di faglie con direzione compresa tra nnw-sse e nw-se, che, attraversando la sicilia nordorientale e il mar tirreno meridionale, raggiunge le isole vulcano, lipari e salina. le unità della catena kabilo – calabride (fig. 2: ckc), costituite da falde di basamento cristallino interessate da metamorfismo ercinico con resti dell’originaria copertura sedimentaria meso-cenozoica, sono sovrascorse sulle unità della catena appenninico maghrebide, in concomitanza dell’apertura del bacino balearico – provenzale e la rotazione del blocco sardo – corso (de jong et al., 1973). la catena appenninico – maghrebide (cam in fig. 2) è costituita da falde sud-vergenti, il cui corrugamento ha interessato, deformandole, le coperture sedimentarie della tetide e dei paleodomini minori ad essa associati, originariamente posti tra il margine della placca europea e il margine della placca africana (finetti et al., 1996). in questo quadro geodinamico compressivo, nel pleistocene inferiore sono iniziate intense fasi tettoniche che hanno causato un’elevata distorsione lungo il margine settentrionale della placca africana, a causa della differente velocità con cui avviene la subduzione al di sotto della catena appenninico maghrebide (morelli, 1970), e ciò ha determinato uno stiramento crostale che ha dato luogo a fratture con direzione nwse, ne-sw ed e-w (ghisetti & vezzani, 1982); all’intersezione di tali strutture si è formata una zona di debolezza attraverso la quale avviene la risalita di magmi sub-crustali (frazzetta & villari, 1981) che hanno dato luogo al complesso edificio vulcanico etneo. il monte etna, con la sua altitudine di poco superiore ai 3.300 metri e col diametro massimo di 44 chilometri, è il maggiore vulcano attivo del continente europeo; esso è uno strato-vulcano complesso, risultante dalla sovrapposizione di prodotti emessi da diversi edifici (gemmellaro, 1858) poggianti su un basamento in parte alloctono, formato da rocce di età compresa tra il cretaceo ed il pleistocene (romano et al., 1979; lentini, 1982). sulla genesi del vulcano e sul quadro strutturale sono stati proposti numerosi modelli, tra i quali: 1) intersezione di importanti lineamenti strutturali, come la scarpata ibleo-maltese e l’allineamento messina-giardini (ogniben et al., 1975; mcguire et al., 1997); 2) formazione di un graben nell’area dell’attuale piana di catania a causa di tettonica estensionale (di geronimo et al., 1978); 3) processi di rifting tra il blocco maltese-siciliano e il bacino ionico (gillot et al., 1994, continisio et al., 1997); 4) deformazione al footwall di una faglia normale appartenente al sistema distensivo siculo-calabro ad andamento wnw-ese (monaco et al., 1997); 5) risalita magmatica mantellica causata dalla presenza di un hot spot (tanguy et al, 1997); 6) roll-back di una porzione di litosfera subdotta al di sotto del mar tirreno (gvirtzman & nur, 1999). fig.2 schema strutturale della sicilia (da finetti et al., 1996). ai) avampaese ibleo; cam catena appenninico – maghrebide; ckc) catena kabilo – calabride; cs) catena sicana; e) edificio vulcanico etneo; agc) avanfossa gela – catania; sim) scarpata ibleo – maltese; smf) sistema di faglie messina – fiumefreddo; il rettangolo indicato dalla freccia corrisponde alla zona in studio. structural scheme of sicily (after finetti et al., 1996). ai) hyblaean foreland; cam) apennine – maghrebian chain; ckc) kabilo – calabrian chain; cs) sicania chain; e) mount etna volcano; agc) gela catania foredeep; sim) hyblaean – malta escarpment; narrow indicates position of studied area. p. carveni, s. benfatto & m. salleo puntillo 61 l’attività eruttiva dell’etna, inizialmente sottomarina e fissurale, è diventata in seguito subaerea ed a carattere centrale, con emissioni da numerosi apparati eruttivi (romano, 1982). gillot et al. (1994), sulla base del rapporto k/ar, hanno distinto quattro periodi di attività dell’etna, alternati a lunghi periodi di quiescenza: il primo periodo (da 520.000 ± 40.000 a 270.000 anni fa) fu caratterizzato da emissioni di lave a composizione tholeiitica attraverso apparati fissurali; il secondo periodo (da 168.000 ± 8.000 a 100.000 anni fa) vide un radicale cambiamento del chimismo del magma, da sub-alcalino ad alcalino, e del tipo di attività, da eruzioni fissurali a eruzioni da condotti centrali, con la conseguente formazione di strato-vulcani; durante il terzo periodo (tra 80.000 e 60.000 anni fa) si formò un grande complesso vulcanico poligenico, denominato trifoglietto; nel quarto periodo (da 35.000 anni fa ad oggi) si è sviluppato il mongibello, un grande strato-vulcano; un’importante fase, caratterizzata da intense eruzioni pliniane e idromagmatiche, permette di suddividere questo periodo in due parti: mongibello antico e mongibello recente. 3. sismicità delversante orientale etneo in precedenti articoli è stata esaminata la sismicità del versante orientale etneo, geneticamente collegata al sistema di faglie delle timpe, e caratterizzata da terremoti con ipocentri superficiali, con profondità compresa tra 0,5 e 2 chilometri (patanè, 1975; benina et al., 1984; lo giudice, 1985; bottari et al., 1989; azzaro et al., 1989 a; 1989 b; lo giudice & rasà, 1992; adorni & carveni, 1993 a; 1993 b; carveni & bella, 1994; bella et al., 1996; carveni et al., 1996; gresta et al., 1997; carveni et al., 1997; ferreli et al., 2000), modesto raggio di avvertibilità e campo macrosismico di pochi chilometri quadrati; come effetto cosismico è stata spesso segnalata l’apertura di fessure nel terreno (grassi, 1865; silvestri, 1865; 1866; 1867; 1883; platania & platania, 1894; platania, 1908; 1920; riccò, 1911; 1912; sabatini, 1914; castorina, 1920; cumin, 1954; riuscetti & distefano, 1971; azzaro et al., 1989 a) e l’innesco di frane lungo pendii instabili (grassi, 1865); la zona è inoltre interessata da fenomeni di creep asismico (lo giudice, 1985). come è stato già accennato, il settore delimitato a settentrione dal rift di ne e dalla faglia della pernicana e a meridione dal sistema montagnola – mascalucia – aci castello, secondo le ipotesi di numerosi autori già citati nell'introduzione, sarebbe interessato da fenomeni di scivolamento verso se; all'interno di questo settore si trovano altri sistemi di faglie, i più importanti dei quali sono: 1) la parte meridionale del sistema giardini – mascali (sgm in fig. 1), con direzione nne-ssw; 2) il sistema ripa della naca – piedimonte (srnp in fig. 1), con direzione ne-sw; 3) il sistema delle timpe (st in fig. 1). le faglie del sistema giardini – mascali costituiscono il prolungamento dell’allineamento messinagiardini di ogniben et al. (1975), che viene intersecato dalla faglia della pernicana a meridione di fiumefreddo; l’attività sismica in tempi storici di questo sistema, sulla base delle informazioni sinora raccolte, è limitata ad una serie di terremoti avvertiti solo in ambito locale nei dintorni di mascali e fondachello; a questa sismicità è stata collegata l’evoluzione di un vulcano di fango conosciuto come salsa di fondachello (mercurio, 1847). l'unico sisma di un certo rilievo è avvenuto il 27 marzo 1847, e fu avvertito lungo la fascia ionica fino a catania; la profondità ipocentrale di questo sisma, anche se non è mai stata calcolata, deve essere maggiore a quelle dei sismi relativi al sistema delle timpe. il secondo sistema è stato attivo in occasione dell'eruzione etnea del 1928: una serie di 13 sismi fu avvertita a piedimonte etneo (pe in fig. 1) tra il 2 e il 9 novembre (azzaro et al., 2000); si trattò chiaramente di movimenti lungo una o entrambe le faglie del sistema, attivatesi in concomitanza della fuoriuscita della colata dalla frattura estensionale apertasi alla base del piano della faglia della ripa di piscio; gli epicentri macrosismici sono stati localizzati a piedimonte etneo in quanto questo centro abitato è ubicato lungo il prolungamento dei piani di faglia, e corrisponde alla zona abitata maggiormente investita dalle onde sismiche. il sistema delle timpe è il più attivo dei tre; ad esso sono legati i più forti terremoti avvenuti nella zona etnea (carveni & bella, 1994); è ipotizzabile che questo sistema di faglie, rispetto a come è stato cartografato sulla carta geologica del monte etna (romano et al., 1979), si inoltri per diversi chilometri verso nnw, ma non se ne hanno evidenze morfologiche a causa della copertura da parte di colate laviche. all'attività di questo ultimo sistema di faglie, oltre che una discreta serie di terremoti registrati ad iniziare dal 1805 (malgrado la zona sia stata intensamente abitata dall'epoca classica non si è riusciti a trovare testimonianze di terremoti anteriori a questo anno), sono attribuiti i fenomeni di abbassamento registrati lungo la linea di costa (carveni et al., 2005 b). 4. testimonianze di instabilità del versante orientale dell'etna che nella sicilia orientale sono presenti numerosi indizi sia geologici sia geomorfologici di variazioni del livello del mare verificatisi nel corso del quaternario è noto: già a partire dal xix secolo sono reperibili in letteratura dati relativi a testimonianze geologico-geomorfologiche di antichi livelli del mare; secondo le nostre ricerche bibliografiche il primo a riconoscere queste testimonianze lungo la costa ionica è stato gemmellaro (1837), il quale ha descritto il solco di battente esistente attorno ai promontori di capo sant’alessio e capo sant’andrea, nei pressi di taormina. recentemente (carveni et al., 2005 b) è stata effettuata una rilettura critica degli articoli in cui si descrivono le tracce geologico-geomorfologiche del graduale sollevamento della zona costiera compresa tra ògnina a meridione (sollevamento di circa 1 metro) e aci castello a settentrione (13 metri); in quest’ultima località ad un progressivo innalzamento a scatti è intercalato un fenomeno di abbassamento, avvenuto posteil sollevamento della sicilia ... 62 riormente all’arrivo di una colata lavica, datata al periodo compreso tra il 122 a.c. e il 252-253 d.c. (romano & sturiale, 1981); più a settentrione, nel porto peschereccio di stazzo (fig. 2: s) e a torre archirafi (fig. 2: ta) vi sono evidenze di un progressivo abbassamento della zona costiera, collegato all’attività delle faglie del sistema delle timpe (carveni et al., 2005 a; 2005 b). l’attività delle faglie del sistema delle timpe è documentata ad iniziare dal 1805 (anno del più antico terremoto di cui si sia conservata la memoria) con sempre maggiore attenzione. è stato evidenziato che gli epicentri dei sismi sono localizzati prevalentemente lungo i segmenti settentrionali delle relative faglie, mentre lungo i tratti meridionali delle stesse si registrano solo fenomeni di creep asismico (carveni & bella, 1994). l’integrazione tra dati provenienti da indagini geoelettriche (cassinis et al., 1970) e dati relativi alle profondità ipocentrali di alcuni sismi (patanè, 1975; postpischl, 1985; azzaro et al., 1989 a; 1989 b; bottari et al., 1989) evidenziando che gli ipocentri di alcuni terremoti sono ubicati al contatto tra le vulcaniti, a comportamento geomeccanico fragile, e le sottostanti argille infra-pleistoceniche, ha fatto ipotizzare una genesi di tipo gravitativo profondo per i movimenti sismici in oggetto (carveni & bella, 1994). 5. fenomeni vulcanici conseguenti all’instabilita’ del versante orientale etneo carapezza (1962) per primo ha tentato di determinare una relazione tra la tettonica regionale e le zone di minore resistenza dell'edificio vulcanico; egli ha riconosciuto una zona di rift che attraversa il fianco orientale del vulcano, corrispondente a quello che verrà in seguito chiamato sistema delle timpe. in verità, fatta eccezione per un minuscolo edificio ubicato in località cutula (fig. 2: cu), attribuito all'attività dei centri eruttivi alcalini antichi (romano et al., 1979), e la cui genesi può essere attribuita ipoteticamente al punto di incontro tra il sistema giardini – mascali e il sistema delle timpe, allo stato attuale delle ricerche non vi sono ulteriori testimonianze di attività vulcanica collegabile a questi due sistemi di faglie per la zona del basso versante orientale etneo, studiato da carapezza (1962). altri autori che più recentemente si sono interessati di questi sistemi di faglie sono adorni & carveni (1993 a; 1993 b); carveni & bella (1994); bella et al. (1996); carveni et al. (1996; 1997); gresta et al. (1997); monaco et al. (1997); monaco & tortorici (2000); ferreli et al. (2000). un'eruzione che invece risulta chiaramente essere fig. 3 schema morfo-tettonico della zona dei monti sartorius (da carveni & benfatto, 2004). a) faglie; b) fratture eruttive; c) coni piroclastici: 1) monte corvo; 2) monte baracca; 3 e 4) i due monti; 5) monte zappinazzo e monti conconi; 6) monte frumento delle concazze; 7) edificio anonimo a sud-ovest di monte frumento delle concazze; 8) monti sartorius; 9) bocche del 1928; d) orlo della valle del bove; e) alti morfologici: 10) monte crìsimo; 11) monte ragamo; 12) monte chiovazzi. morpho-tectonic scheme of the monti sartorius zone (after carveni & benfatto, 2004). a) faults; b) eruptive fractures; c) cinder cones: 1) monte corvo; 2) monte baracca; 3 and 4) i due monti; 5) monte zappinazzo and monti conconi; 6) monte frumento delle concazze; 7) no name cinder cone sw from monte frumento delle concazze; 8) monti sartorius; 9) 1928 eruption’s vents; d) valle del bove rim; e) peaks: 10) monte crìsimo; 11) monte ragamo; 12) monte chiovazzi. p. carveni, s. benfatto & m. salleo puntillo stata alimentata da due sistemi di faglie, rispettivamente con direzione ene-wsw e nnw-sse è quella avvenuta nel 1865, e che ha dato origine agli edifici denominati monti sartorius (fig. 3). come è stato evidenziato (carveni et al., 1998; 2000; carveni & benfatto, 2004) la disposizione delle bocche eruttive dimostra chiaramente la presenza di due distinti sistemi di fratture eruttive: un sistema principale ene-wsw, parallelo al sistema ripa della naca – piedimonte, e un sistema nnw-sse, attribuibile ad un ipotetico prolungamento verso nnw del sistema delle timpe. l'ipotesi è suffragata da una serie di scosse premonitrici che avevano allarmato gli abitanti di san giovanni (fig. 2: sg), di sant'alfio (fig. 2: sa) e della contrada monti arsi (fig. 2: cma), località ubicate lungo l'ipotizzato prolungamento verso nnw del sistema delle timpe; nel momento in cui iniziava l'eruzione lungo la frattura principale (ene-wsw), un sisma del 5° o 6° della scala mercalli, fece uscire dalle case gli abitanti delle suddette zone in preda al panico; lo stesso sisma fu avvertito ad acireale (fig. 2: a), ma non a giarre (fig. 2: gi); ciò confermerebbe l'ipotesi che si sia trattato di un movimento lungo una delle faglie del sistema delle timpe (carveni & benfatto, 2004). 6. conclusioni l’analisi della sismicità e di parte dell’attività vulcanica verificatesi nell’area oggetto di studio suggerisce che i due principali sistemi di faglie attive della zona sono collegabili geneticamente a fenomeni gravitativi profondi, e ciò in accordo con le ipotesi di rasà et al. (1996) e neri et al. (2003). il sistema ripa della naca – piedimonte, oltre a dare luogo a faglie sismicamente attive, è stato interessato in tempi storici da almeno tre eruzioni: 1865, 1928 e 1971 (fig. 3). si ipotizza, per l’eruzione del 1865, che la risalita magmatica sia iniziata attraverso il condotto centrale e da qui si sarebbe spostata verso il fianco orientale attraverso una serie di fratture radiali, le quali, nella parte periferica, hanno una loro prosecuzione nel sistema timpa della naca – piedimonte; l’intrusione magmatica ha trovato delle vie di risalita preferenziali nell’intersezione con il sistema di faglie delle timpe (carveni & benfatto, 2004); i sismi antecedenti e concomitanti con l’eruzione, chiaramente collegati all’attività di questo ultimo sistema, rafforzano l’ipotesi. fenomeni analoghi sono stati registrati nel corso delle eruzioni del 1928 e del 1971; nel primo episodio l’eruzione iniziò dalla zona sommitale, per spostarsi in seguito sul versante nord-orientale; nella fase finale avvenne l’apertura di bocche eruttive in corrispondenza della faglia della ripa di piscio. uno sciame sismico fu avvertito subito prima e in concomitanza dell’apertura di queste ultime bocche dagli abitanti di piedimonte, centro abitato ubicato esattamente lungo la prosecuzione del sistema di faglie. nel 1971 la prima fase dell’eruzione avvenne nella zona sommitale; quindi si aprì una frattura eruttiva sul versante nord-orientale, parallelamente a quella del 1928; nel corso dell’eruzione un sisma di intensità pari al viii ix grado mcs danneggiò gravemente sciara, frazione di s. giovanni (sg, in fig. 1), ubicata lungo la prosecuzione del sistema delle timpe. la concomitanza, tra un terremoto causato dalla faglia di moscarello (sistema delle timpe) durante un'eruzione lungo una frattura del sistema timpa della naca piedimonte, sosterrebbe l'ipotesi di un collegamento tra i due sistemi. nel 2002, ad uno scivolamento per blocchi del settore est dell’edificio etneo (neri et al., 2003) seguì dapprima un sisma dell’viii grado mcs (azzaro et al., 2006) e successivamente una eruzione che iniziò dal rift di ne e proseguì sul versante meridionale (ingv, 2003), interessando così la parte più elevata della “zona di distacco” del versante orientale. tutto ciò sarebbe da mettere in relazione con i fenomeni di instabilità che interessano il settore orientale etneo, il quale tende a scivolare verso il mare jonio, come è già stato ampiamente ipotizzato da diversi autori ad iniziare dal secolo scorso, e ci porta ad aderire ai modelli interpretativi presentati da rasà et al. (1996) e da neri et al. (2003). ringraziamenti si ringrazia il referee per gli utili consigli. studio effettuato con i fondi del m.i.u.r., nell’ambito delle ricerche “morfodinamica di zone vulcaniche e/o sismicamente attive” e “morfodinamica di zone costiere sismicamente attive”, responsabile pietro carveni. lavori citati adorni g. & carveni p. (1993 a) geomorphology and seismotectonic elements in the giarre area, sicily. earth surf. proc. land., 18, 275-283. adorni g. & carveni p. (1993 b) anomalie del reticolo idrografico causate da eventi sismotettonici sul basso versante orientale dell’etna. boll. acc. gioenia sc. nat. catania, 26 (342), 197-206. amore c., carveni p., scribano v. & sturiale c. (1988) facies ed età del vulcanismo nella fascia sudorientale della sicilia (pachino capo passero). boll. soc. geol. it., 107, 11 pp. azzaro r., barbano m.s., antichi b. & rigano r. (2000) catalogo macrosismico dei terremoti etnei dal 1832 al 1998. acta vulcanologica, 12 (12), 3-36, con cd-rom. azzaro r., carveni p., lo giudice e. & rasà r. (1989 a) il terremoto di codavolpe (basso versante orientale etneo) del 29 gennaio 1989: campo macrosismico e fatturazione cosismica. boll. g.n.v., 1, 112. azzaro r., d'amico s., mostaccio a., scarfì l. & tuvè t. (2006) catalogo macrosismico dei terremoti etnei dal 1832 al 1998. aggiornamento 20022005. quaderni di geofisica, 41, 62 pp. azzaro r., lo giudice e. & rasà r. (1989 b) catalogo degli effetti macrosismici e delle fenomenologie da creep nell’area etnea dall’agosto 1990 al dicembre 1989. boll. g.n.v., 1, 13-46. bella d., carveni p., musumeci c. & gresta s. (1996) 63il sollevamento della sicilia ... aspetti geomorfologici conseguenti all'attività sismica locale sul basso versante orientale del vulcano etna. il quaternario, 9 (1), 365-368. benina a., imposa s., gresta s. & patanè g. (1984) studio macrosismico e strumentale di due terremoti tettonici avvenuti sul versante meridionale dell’etna. att. 3° conv. g.n.g.t.s., 2, 931-940. borgia a., ferrari l. & pasquarè g. (1992) importance of gravitational spreading in the tectonic and volcanic evolution of mt. etna. nature, 357, 231-235. bottari a., carveni p., lo giudice e., pietrafesa m., birritta g. & stillitani e. (1989) criteri di utilizzo e rappresentazione grafica del dato macrosismico nella redazione di una carta sismotettonica. att. 8° conv. ann. gr. naz. geof. terra solida, 191-202. bousquet j.c, & lanzafame g. (2001) nouvelle interprétation des fractures des éruptions latérales de l’etna: conséquences pour son cadre tectonique. boll. soc. géol. france, 172 (4), 455-467. burollet p.f, mugnot g.m. & sweeney p. (1978) the geology of the pelagian block: the margins and basins of southern tunisia and tripolitania. in: nairn a., kanes w. & stelhi f.g., eds., the ocean basins and margins, plenum press, new york, 331-339. carapezza m. (1962) un esempio di eruzione laterale da faglia nell'apparato eruttivo etneo. acta geologica alpina, 8, 249-276. carbone s., grasso m. & lentini f. (1987) lineamenti geologici del plateau ibleo (sicil ia s.e.). presentazione delle carte geologiche della sicilia sud-orientale. mem. soc. geol. it., 38, 127-135. carveni p. & bella d. (1994) aspetti geomorfologici legati ad attività sismica su vulcani attivi: il basso versante orientale dell'etna come modello di studio. boll. acc. gioenia sc. nat., 27 (346), 253-285. carveni p., bella d., benfatto s., maniscalco r., salleo puntillo m. & sturiale g., (2005 b) sollevamenti a grande scala e conseguenti fenomeni gravitativi: l’esempio del versante orientale dell’etna (sicilia). il quaternario, 18 (2), 157-171. carveni p., bella d., filetti g., leonardi m.c., musumeci c. & sturiale g. (1996) zonazione sismica del territorio di giarre (catania) mediante l'analisi di sismi locali avvenuti nel periodo 1855-1989. att. conv. lincei, "la stabilità del suolo in italia: zonazione sismica-frane", 134, 389-393. carveni p. & benfatto s. (2004) l’eruzione etnea del 1865 (monti sartorius): aspetti geomorfologici e inquadramento nell’evoluzione del vulcano. il quaternario, 17 (1), 41-54. carveni p., benfatto s., maniscalco r., salleo m. & sturiale g. (2005 a) controllo tettonico sulla morfologia del basso versante nord-orientale dell’etna (sicilia). il quaternario, 18 (2), 57-68. carveni p., caruso v., pappalardo a. & sturiale g. (1998) aspetti morfo-strutturali e fenomenologie dell’eruzione etnea del 1865 (monti sartorius). att. 79° congr. soc. geol. it., abstracts, a, 342-245. carveni p., caruso v., pappalardo a. & sturiale g. (2000) morpho-structural features and phenomenology of the 1865 eruption (monti sartorius) of mt. etna (sicily). mem. soc. geol. it., 55, 389-395. carveni p., filetti g. & bella d. (1997) aspetti geomorfologici e sismologici connessi a fenomeni di tettonica gravitativa nel basso versante orientale dell'etna. geogr. fis. dinam. quat., 20, 43-49. carveni p., grasso m.f., romano r. & tricomi s. (1991 a) vulcanismo del margine settentrionale ibleo. mem. soc. geol. it., 47, 417-429. carveni p., leonardi a. & romeo m. (1993) rapporti tra vulcaniti submarine e depositi plio-pleistocenici dei dintorni di palagonia (avampaese ibleo, sicilia). boll. acc. gioenia sc. nat., 26 (342), 207237. carveni p., romano r., capodicasa a. & tricomi s. (1991 b) geologia dell'area vulcanica di capo passero (sicilia sud-orientale). mem. soc. geol. it., 47, 431-447. carveni p. & sturiale g. (1999) fasi tettoniche, fenomeni vulcanici e geomorfologia della zona di monte casale di san basilio, lungo il margine settentrionale dei monti iblei (sicilia orientale). il quaternario, 12 (1), 85-98. casero p., cita m.b., croce m. & de micheli a. (1984) tentativo di interpretazione evolutiva della scarpata di malta basata su dati geologici e geofisici. mem. soc. geol. it., 27, 233-153. cassinis r., cosentino p., ponzini g.s. & riuscetti m. (1970) contributo all'esplorazione geofisica lungo la costa etnea. att. conv. inter. sulle acque sotterranee, 6-8 dicembre 1970, palermo, 11 pp. castorina g. (1920) sul terremoto di codavolpe (26 settembre 1920). tipografia dante alighieri, riposto, 16 pp. continisio r., ferrucci f., & gaudiosi g. (1997) malta escarpment and mt etna: early stages of an asymmetric rifting process? evidences from geophysical and geological data. acta vulcanologica, 9, 45-53. cristofolini r. (1966) le manifestazioni eruttive basiche del trias superiore nel sottosuolo di ragusa. per. min., 35, 1-38. cristofolini r., lentini f., patanè g. & rasà r. (1979) integrazione di dati geologici, geofisici e petrologici per la stesura di un profilo crostale in corrispondenza dell’etna. boll. soc. geol. it., 98, 239-247. cumin g. (1954) il terremoto di codavolpe (versante orientale dell’etna) dell’8 aprile 1950. boll. sed. acc. gioenia sc. nat. catania, s. iv, 2, 473-483. de jong k.a., manzoni m., stravenga t., van djikbf., van der voo r. & zijderveld j.d.a. (1973) paleomagnetic evidence for rotation of sardinia during the early miocene. nature, 243, 281-283. di grande a. (1967) i sedimenti pleistocenici del margine settentrionale dell'altipiano ibleo. att. acc. gioenia sc. nat. catania, serie vi, 18 (suppl. sc. geol.), 247-263. di grande a. (1969) l'alternanza neogenico-quaternaria di vulcaniti e sedimenti al margine nord-occidentale dell'altipiano ibleo. att. acc. gioenia sc. nat. catania, 4, 36 pp. di grande a. (1972) geologia dell'area a nord di augusta – francofonte (sicilia se). att. acc. gioenia sc. nat. catania, serie vii, 4, 1-32. di geronimo i., ghisetti f., lentini f. & vezzani l. (1978) lineamenti neotettonici della sicilia orientale. mem. soc. geol. it., 19, 543-549. ferrari l., gardun‚ o v.h. & neri m. (1991) i dicchi della valle del bove, etna: un metodo per stimare le 64 p. carveni, s. benfatto & m. salleo puntillo dilatazioni di un apparato vulcanico. mem. soc. geol. it., 47, 495-508. ferreli l., azzaro r., bella d., filetti g., michetti a.m., santagati f., serva l. & vittori e . (2000) analisi paleosismologiche ed evoluzione olocenica della fagliazione superficiale lungo la timpa di moscarello, m. etna (sicilia). boll. soc. geol. it., 119, 251-265. ferrucci f., rasà r., gaudiosi g., azzaro r. & imposa s. (1993) mt. etna: a model for the 1989 eruption. j. volc. geoth. res., 56, 35-56. finetti i. (1982) structure, stratigraphy and evolution of central mediterranean. boll. geof. teor. appl., 96, 247-312. finetti i., lentini f., carbone s., catalano s. & del ben a. (1996) il sistema appennino meridionale arco calabro sicilia nel mediterraneo centrale: studio geologico-geofisico. boll. soc. geol. it., 115, 529-559. firth c., stewart i., mcguire w.j., kershaw s. & vitafinzi c. (1996) coastal elevation changes in eastern sicily: implications for volcano instability at mount etna, in mcguire w.j., jones a.p. & neuberg j. (eds), volcano instability on the earth and other planets, geol. soc. spec. pubbl., 110, 153167. frazzetta g. & villari l. (1981) the feeding of the eruptive activity of etna volcano. the regional stress field as a constraint to magma uprising and eruption. bull. volcan., 44 (3), 269-282. gemmellaro c. (1837) sopra il terreno giurassico di sicilia. memoria prima sul terreno giurassico di tauromina. att. acc. gioenia sc. nat., 12, 353375. gemmellaro c. (1858) la vulcanologia dell’etna. la topografia, la geologia, la storia delle sue eruzioni, la descrizione e lo esame de’ fenomeni vulcanici. tipografia dell’accademia gioenia di c. galatola, catania, 267 pp. ghisetti f. & vezzani l. (1982) the recent deformation mechanism of the calabrian arc. in: mantovani e. & sartoni r. (editors): structur, evolution and present dynamics of the calabrian arc . earth evolution sciences, 3, 197-206. gillot p.y., kieffer g. & romano r. (1994) the evolution of mount etna in the light of potassium-argon dating. acta vulcanologica, 5, 81-87. gironi f. (2003) cosa c'è sotto. quark, 23, 50-57. grassi m. (1865) relazione storica ed osservazioni sull’eruzione etnea del 1865 e su’ tremoti fregrei che la seguirono. tipografia galatola, catania, 92 pp. gresta s., bella d., musumeci c. & carveni p. (1997) some efforts on active faulting processes (earthquakes and aseismic creep) acting on the eastern flank of mt etna (sicily). acta vulc., 9 (1), 1-8. gvirtsman z. & nur a. (1999) the formation of mount etna as the consequence of slab rollback. nature, 401, 782-785. istituto nazionale di geofisica e vulcanologia sez. di catania (2003) banca dati delle eruzioni. eruzione dell’etna 2002. http://www.ct.ingv.it. kieffer g. (1983 a) l’évolution struttural de l’etna (sicile) et les modalités du contrôle tectonique et volcano-tectonique de son activité. faits et hypothèses après les éruptions de 1978 et 1979. rev. géogr. phys. géol. dyn., paris, 24 (2), 129152. kieffer g. (1983 b) dèplacement progressif vers l’est des voies d’alimentation magmatiques de l’etna (sicile). bull. soc. géol. fr., 25 (3), 369-378. lanzafame g. & bousquet j.c. (1997) the maltese escarpment and its extension from mt etna to the aeolian islands (sicily): importance and evolution of a lithosphere discontinuity. acta vulcanologica, 9, 121-133. lentini f. (1982) the geology of the mt. etna basement. mem. soc. geol. it., 23, 7-25. lo giudice e. (1985) particolari aspetti del rischio sismico nell’area etnea. att. conv. int. assoc. geogr. it.: l’organizzazione territoriale delle aree sismiche e vulcaniche, 59-85. lo giudice e. & rasà r. (1992) very shallow earthquakes and brittle deformation in active volcanic areas: the etnean region as an example . tectonophysics, 202, 257-268. mcguire w.j., stewart i.s. & saunders s.j. (1997) intravolcanic rifting at mount etna in the context of regional tectonics. acta vulcanologica, 9, 147156. mercurio g.a. (1847) sulla salsa di fondachello nel comune di mascali, del profondamento parziale del cono argilloso e dell'apparizione d'un'acqua minerale gassosa. stabilimento di pietro giuntini, catania, 29 pp. monaco c., tapponnier p., tortorici l. & gillot p.y. (1997) late quaternary slip rates on the acirealepiedimonte normal faults and tectonic origin of mt. etna (sicily). earth planet. sc. lett., 147, 125139. montalto a., vinciguerra s., menza s. & patanè g. (1996) recent seismicity of mount etna: implications for flank instability, in mcguire w.j., jones a.p. & neuberg j. (eds), volcano instability on the earth and other planets, geol. soc. spec. pubbl., 110, 169-177. morelli c. (1970) physiography, gravity and magnetism of the tyrrhenian sea. boll. geof. teor. appl., 12, 275-305. neri m., acocella v. & behncke b. (2003) the role of pernicana fault system in the spreading of mt. etna (italy) during the 2002-2003 eruption. bull. volcanology (2003) 15 pp. neri m., gardun‚ o v.h., pasquarè g. & rasà r. (1991) studio strutturale e modello cinematico della valle del bove e del settore nord-orientale etneo. acta vulcanologica, 1, 17-24. obrizzo f., pingue f., troise c. & de natale g. (2001) coseismic displacements and creeping along the pernicana fault (etna, italy) in the last 17 years: a detailed study of a tectonic structure on a volcano. jour. volc. geoth. res., 109, 109-131. ogniben l., parotto m. & praturlon a. (1975) structural model of italy. c.n.r., quaderni de “la ricerca scientifica”, 90, 502 pp. patanè g. (1975) i terremoti di s.m. ammalati e di guardia dell’agosto 1973. riv. min. sic., (154156), 199-206. patanè g., montalto a., imposa s. & menza s. (1994) the role of regional tectonics, magma pressure and gravitational spreading in earthquakes of the 65il sollevamento della sicilia ... eastern sector of mt. etna volcano (italy). j. volc. geoth. res., 61, 253-266. platania g. (1908) il terremoto del 7 dicembre 1907. rend. e mem. r. acc. zelanti di acireale, 3 (6), 13-20. platania g. (1920) terremoto di codavolpe (etna) del settembre 1920. boll. r. osserv. geodin. catania, 8 pp. platania g. (1922) origine dei terrazzi dell’etna. pubbl. ist. geogr. fis. r. univ. catania, (19), 11 pp. platania g. & platania g. (1894) note sui terremoti etnei. rendic. acc. sc. lett. e art. zelanti di acireale, 6, 5 pp. postpischl d., editor (1985) catalogo dei terremoti italiani dall'anno 1000 al 1980. pr. fin. geodin.cnr, quaderni de la ricerca scientifica, 114-2a, bologna. rasà r. & azzaro r. (1995) creep su faglia e sue implicazioni sulla statica del versante orientale dell’etna. in: ferrucci f. & innocenti f. (eds.), progetto etna 1993-1995. giardini, pisa, 137-143. rasà r., azzaro r. & leonardi o. (1996) a seismic creep on faults and flank instability at mount etna volcano, sicily, in mcguire w.j., jones a.p. & neuberg j. (eds), volcano instability on the earth and other planets, geol. soc. spec. pubbl., 110, 179-192. riccò a. (1911) terremoto di guardia del 21 ottobre 1909. boll. acc. gioenia sci. nat., 10, 6-11. riccò a. (1912) fenomeni geodinamici consecutivi all'eruzione etnea del settembre 1911. boll. soc. sism. it., 16, 11-32. riuscetti m. & distefano r. (1971) il terremoto di macchia (catania). boll. geof. teor. appl., 13 (51), 150-164. romano r. (1982) succession of the volcanic activity in the etnean region. mem. soc. geol. it., 23, 2748. romano r., lentini f., sturiale c., amore c., atzori p., carter s.r., cristofolini r., di geronimo i., di grande a., duncan a.m., ferrara v., ghisetti f., guest j.e., hamill h., patanè g., pezzino a., puglisi d., schilirò f., torre g. & vezzani l. (1979) carta geologica del monte etna, scala 1:50.000, litogr. art. cartogr., firenze. romano r. & sturiale c. (1981) geologia del versante sud-orientale etneo, f°. 270 iv (no, ne, so, se). boll. soc. geol. it., 100 (1), 11-40. sabatini v. (1914) note sul terremoto di linera dell'8 maggio 1914. boll. r. comit. geol. it., 44, 245293. silvestri o. (1865) relazione sopra i terremoti dell’etna. stabilimento tipografico “la fenice”, catania, 12 pp. silvestri o. (1866) sull'eruzione dell'etna del 1865. studi geologici e chimici. "nuovo cimento", 2122, 20 pp. silvestri o. (1867) i fenomeni vulcanici presentati dall’etna nel 1863-64-65-66 considerati in rapporto alla grande eruzione del 1865. mem. acc. gioenia sc. nat., 3 (1), 53-319. silvestri o. (1883) sulla esplosione etnea del 22 marzo 1883 in relazione ai fenomeni vulcanici (geodinamici ed eruttivi) presentati dall'etna durante il quadriennio compreso dal gennaio 1880 al dicembre 1883. osservazioni e studi. att. acc. gioenia sc. nat., 3 (18), 237-421. tanguy j.c., condomines m. & kieffer g. (1997) evolution of the mount etna magma: constraints on present feeding system and eruptive mechanism. jour. volc. geot. res., 75, 221-250. tibaldi a. & groppelli g. (2002) volcano-tectonic activity along structures of the unstable ne flank of mt. etna (italy) and their possible origin. jour. volc. geoth. res., 115, 277-302. 66 ms. ricevuto il 16 maggio 2006 testo definitivo ricevuto il 4 gennaio 2007 ms. received: may 16, 2006 final text received: january 4, 2007 p. carveni, s. benfatto & m. salleo puntillo microsoft word 00_indice_06lm.docx il quaternario it issn 039-3356 italian journal of quaternary sciences 24 (2), 2011 179-189 la catastrofe idrogeologica del 1581 nei monti picentini (sa) tra evidenze d’archivio e indagini geomorfologiche giuseppe esposito1 & paolo galli1,2 1 dipartimento della protezione civile, roma 2 cnr-igag, montelibretti corresponding author: paolo galli <paolo.galli@protezionecivile.it> riassunto: esposito g. & galli p., la catastrofe idrogeologica del 1581 nei monti picentini (sa) tra evidenze d’archivio e indagini geomorfologiche. l’area occidentale dei monti picentini, a ne di salerno, è storicamente interessata da fenomeni di colata rapida di fango o detrito (mud or debris flow). nel presente studio sono state raccolte notizie storiche relative agli effetti provocati da un evento catastrofico quasi sconosciuto avvenuto nel 1581 negli attuali comuni di castiglione del genovesi, san cipriano picentino e giffoni sei casali e ne sono state ricercate le cause geologico-morfologiche di innesco e sviluppo. sono state condotte sia ricerche archivistiche su documenti dell’epoca che fotointerpretazione e rilevamento di campagna, identificando anche una serie di elementi naturali ed antropici che concorrono ad innalzare i valori di rischio attuali. i dati geologici sono stati informatizzati in ambiente gis, evidenziando i fenomeni di dissesto (soil slip evolutisi in mud or debris flows) verosimilmente verificatisi nell’evento del 1581, ed il reticolo idrografico che potrebbe costituire la via preferenziale per il trasferimento di nuove colate da monte verso valle, attraverso aree abitate che risultano attualmente a rischio. è stata cartografata, inoltre, la porzione del reticolo idrografico interessata da una colata avvenuta il 30 luglio 2010 durante le fasi di rilevamento. i risultati dello studio indicano che ancora oggi sussistono tutti i fattori geologici e geomorfologici che già nel 1581 hanno predisposto l’area a fenomeni di particolare violenza ed estensione, con l’aggravante che nei centri abitati attuali vi sono condizioni urbanistiche che possono amplificare notevolmente gli effetti di nuovi mud or debris flows. abstract: esposito g. & galli p., the 1581 hydrogeologic disaster in the picentini mounts (campania, southern italy) between archive and geomorphological researches. the western slopes of the carbonate picentini mountains have been historically affected by mud or debris flows involving the thick pyroclastic-derived soils mainly originated from the vesuvius volcano tephra. in this paper we took both a historical and geomorphological approach to the revisiting of one of the most catastrophic hydrogeological events of the whole campania region (tyrrhenian southern italy). we carried out researches in archives looking for original documents describing the effects of the poorly known 1581 alluvial flood, finding coeval reports which account for more than 700 victims and terrific damage to buildings and factories. we have also carried out aerophotos interpretation and field survey in the area affected by this historical storm and flood (i.e., in the municipalities of castiglione del genovesi, san cipriano picentino and giffoni sei casali, ne of salerno), finding conclusive evidence of ancient, recent and present flow-like mass movements, involving mainly distal volcanic deposits (reworked and pedogenized ashes and pumices) and slope debris. these features affect several inhabited settlements of the area, constituting a very high risk factor for the region. parole chiave: colata rapida di fango o detrito, rischio idrogeologico, campania. keywords: mud flow, debris flow, hydrogeological risk, campania. introduzione le colate rapide di fango o detrito (mud flows e debris flows, hungr et al., 2001) sono i fenomeni naturali più pericolosi in vaste aree della campania, principalmente a causa della velocità dei flussi e della quasi totale assenza di segnali premonitori. solo negli ultimi quattro secoli risultano essere avvenuti almeno 500 eventi distruttivi, più della metà dei quali registrati negli ultimi 100 anni (bisson et al., 2007). le vittime causate da questi fenomeni sono migliaia (vedi in u.o. 2.38, 1998), in genere improvvidamente residenti in aree poste nelle zone di potenziale deflusso ed espansione dei depositi, quali conoidi o fasce pedemontane (p.e., le 160 persone a sarno, quindici, siano e bracigliano nel 1998). le cause predisponenti di questa tipologia di dissesto sono insite nelle scadenti caratteristiche geomeccaniche delle potenti coltri incoerenti di ceneri e pomici vesuviane e flegree che mantellano i rilievi campani, nonché nella forte acclività di questi ultimi (cascini et al., 2005 e bibliografia ivi citata). a innescare i flussi sono invece le precipitazioni piovose intense che determinano la saturazione delle coltri pedogenizzate; in particolari situazioni morfologiche, queste possono scivolare lungo il substrato roccioso determinando delle frane da soil slip che evolvono poi in colate (de vita & celico, 2006; guadagno f.m., 2000; hungr et al., 2001). un’ulteriore causa di innesco può essere costituita dal ruscellamento selvaggio delle acque meteoriche, capaci di prendere in carico detrito e sedimenti localizzati lungo le aste di drenaggio determinando lo sviluppo di debris flows che talvolta possono evolvere in flussi iperconcentrati definiti debris floods (hungr et al., 2001), caratterizzati da una maggiore componente liquida. i flussi così generati possono incanalarsi negli impluvi lungo i versanti riversandosi nelle zone pedemontane con notevole eesposito g. & galli p. 180 nergia, tracimando dagli alvei e investendo le aree limitrofe, spesso abitate. il presente studio interessa il settore sudoccidentale dei monti picentini, nell’area di castiglione del genovesi, san cipriano picentino e giffoni sei casali, a nordest di salerno, dove nel 1581 si verificò una vera e propria catastrofe idrogeologica, con diverse centinaia di morti. il lavoro è stato sviluppato seguendo un approccio multidisciplinare che ha comportato sia ricerche di ambito archivistico su documenti storici dell’epoca sia geomorfologiche. queste ultime sono state condotte tramite fotointerpretazione e rilevamenti di campagna, contribuendo ad individuare i fenomeni che probabilmente hanno caratterizzato l’evento in questione, e a fornire una valutazione in termini qualitativi dell’attuale suscettibilità all’innesco di mud or debris flows nei tre comuni citati. a tali ricerche è stato associato un rilevamento delle criticità territoriali che potrebbero amplificare gli effetti di eventi futuri. cenni sulla geologia e morfologia dell’area di studio i comuni di castiglione del genovesi, san cipriano picentino, e la frazione prepezzano di giffoni sei casali sorgono alle pendici del monte monna, un massiccio costituito da una serie calcareo-dolomitica mesozoica, appartenente all’unità stratigrafico-strutturale “monti picentini-monte taburno” dell’appennino meridionale (bonardi et al., 1988). tale unità è sovrascorsa sui sedimenti calcareo-silico-marnosi mesozoici lagonegresi che affiorano in finestra tettonica nell’area di giffoni sei casali (scandone et al., 1967). in contatto tettonico si ritrovano i depositi mesozoico-terziari del complesso sicilide, costituiti da argilliti, marne e torbiditi calcaree, in affioramento presso castiglione e san cipriano (bonardi et al., 1988). le litologie più recenti sono costituite da conglomerati e brecce pleistoceniche affioranti sui versanti del monte monna. tutte queste successioni sono mantellate da coltri pedogenizzate di depositi piroclastici (andosuoli; soil survey staff, 1999) derivanti dalle eruzioni del pleistocene superiore-olocene dei complessi vulcanici campani del somma-vesuvio e dei campi flegrei, le cui caratteristiche chimicofisiche e mineralogiche sono ritenute tali da costituire causa predisponente per l’innesco di frane superficiali nelle porzioni medio-alte dei versanti (terribile et al., 2000 e 2007; vingiani & terribile, 2007). è opportuno notare che rispetto ai tephra già in posto all’atto dell’evento del 1581, a seguito dell’eruzione sub pliniana del 1631 (ma anche di altre), molto materiale di ricaduta si è accumulato sui versanti dei picentini, ispessendo ulteriormente i depositi storici (p.e., quelli del 79 d.c.) e preistorici deposti ad est degli apparati campani (p.e., ap, mercato, pomici di base; vedi in santacroce et al., 2008) di cui sopra. nelle coltri localizzate alla base dei rilievi, potenti oltre 10 metri, sono stati riconosciuti diversi suoli sepolti intercalati con livelli di mud or debris flows. è inoltre importante notare che i rilievi calcareo-dolomitici danno luogo a versanti particolarmente acclivi rispetto a quelli costituiti dalle formazioni lagonegresi (calcari con selce, scisti silicei, flysch). di fatto, il versante occidentale del monte monna è caratterizzato da forti acclività e da scarpate sub-verticali legate a processi di erosione differenziale tra bancate calcaree più resistenti e strati sottili più erodibili. tutti i versanti, poi, sono caratterizzati da impluvi che, in alcuni casi, sono sedi di torrenti permanenti e possono rappresentare delle vie preferenziali per il deflusso delle colate. metodologia di lavoro lo studio ha seguito un approccio multidisciplinare, con ricerche sia di carattere storico-archivistico che geomorfologico. i dati di carattere storico si sono rivelati decisivi per conoscere e caratterizzare, seppur qualitativamente, la tipologia dei fenomeni d’instabilità che si sono verificati ripetutamente in passato nell’area di studio (p.e., in peronace et al., 2009). il primo passo è consistito nel ritrovamento nell’archivio di stato di napoli di un documento inedito relativo a un importante evento alluvionale avvenuto nel 1581 nel salernitano. in seguito, la ricerca storica è stata approfondita presso l’archivio di stato di salerno, dove sono state reperite ulteriori fonti riguardanti l’evento. di concerto è stata condotta una ricerca bibliografica sulle frane e le alluvioni avvenute nell’area d’indagine nel corso dei secoli. fig. 1 schema filologico dell'evento catastrofico del 1581. gli ovali indicano le notizie primarie; il colore grigio indica la notizia inedita. i rettangoli indicano le notizie secondarie. lo sfondo è costituito da una delle pagine della lettera rinvenuta nell’archivio di stato di napoli. philological tree of the historical sources describing the 1581 catastrophic flood. the ovals envelop the primary sources (gray, unpublished news). the background is one of the original page of the letter of the partium of the regia camera della sommaria (naples archive) which accounts in detail the event. la catastrofe idrogeologica del 1581 nei monti picentini … 181 la seconda parte della ricerca, invece, è stata finalizzata all’analisi delle caratteristiche geomorfologiche e geologiche dell’area e all’individuazione dei probabili dissesti connessi con l’evento in questione. a valle dello studio foto-interpretativo sul volo igm realizzato in occasione del terremoto irpino del 1980, è seguito il rilevamento di campagna su base cartografica ctr alla scala 1:5000. ciò ha permesso di riconoscere gli elementi geologici e morfologici tipici dei mud or debris flows pregressi, rappresentarli tramite cartografia tematica digitalizzata in ambiente gis e identificare le zone interessate dai fenomeni che hanno verosimilmente caratterizzato l’evento del 1581 e quelle in cui vi è un’attuale suscettibilità all’innesco e al transito delle colate. è importante sottolineare che la valutazione della suscettibilità non è stata realizzata mediante una metodologia quantitativa, ma bensì sul solo accertamento delle cause predisponenti per l’innesco e lo sviluppo dei fenomeni e sulla localizzazione di quelli pregressi. in base a questi elementi e alle informazioni storiche raccolte sono state poi formulate le relative conclusioni. la parte finale dello studio è stata dedicata all’individuazione delle criticità territoriali che in caso di nuovo evento possono incrementare il rischio che grava sugli abitanti dei tre comuni oggetto della ricerca, già quantificato dagli studi dell’autorità di bacino destra sele (adb) con i quali è stato fatto un opportuno confronto. fig. 2 estrazione da progetto gis di elementi relativi al dissesto idrogeologico dell’area investigata su modello digitale del terreno (dtm) a 10 metri. si noti come molte aree di colata rapida di fango o detrito interessino i centri abitati della zona a conferma degli effetti devastanti che si verificarono nell’alluvione del 1581. i riquadri a-b-c delimitano le aree delle figg.10-12, rispettivamente. digital terrain model (10-m-grid) reporting the main landslides features of the investigated area. note that many rapid mud or debris flows presently affect the inhabited zones, accounting for the devastating effects of the 1581 alluvial flood. dashed frames a-b-c indicate the areas of figs.10-12, respectively. 182 fig.3 affioram debris flow ou l’evento d questo specializzata gale & milo un’area disas e da porfido d’acqua inter la, bonea, p (sistema info cnr-gndci nell’anno 158 foni vallepian fine di appro ne e gravità delle fonti de una ricerca s napoli e sale napoli ed in sono state rin tera scritta p del vasto alla ria del regno evince che l’e domenica 1 più di 700 v baronia di s morti è piutto to al numero aveva al mom stima effettua censito nel 15 poi i danni e v le a fronte de abitanti. in pa ne di “una inf “valchere, ten con annesse cati lungo i c tavano la pa baronesche”. mente eleva rimasto alla “castagne” e lii convicini”. rarsi come f vento, unitam zionati da e l’archivio di s del notaio ge menti dei depositi tcrops observed w del 1581 o evento è parz a ed è nominato one, 1998), ch strata estesa to o et al. (2009 ressati dalle es picentino, fuorn ormativo sulle c ) l’evento è 80 per i comun na, con un num fondire le cono degli effetti e escrittive dello s storico archivis erno, nelle bibl numerose altre nvenute notizie pochi giorni do a regia camer o di napoli (fig evento è avven ottobre 1581 e ittime nelle “t[e san cipriano”. osto elevato, spe di abitanti che g mento del disas ata in base al n 561). nella lette viene richiesta l ella perdita tota articolare è ripo finità di case”, ch ntere, saponere” e tintorie), proba corsi d’acqua e rte più cospicu . il grado di di ato che l’unico popolazione è negli aiuti prov tale document fonte primaria mente ai protoco sposito et al. stato di salerno eronimo fiore, n di debris flows in within three differ ialmente noto a o da amarotta he lo pone nel out cour a giffo 9), che eviden ondazioni (i.e., ni, e loro afflue catastrofi idrog classificato c ni di giffoni sei mero di vittime im oscenze sulla re ricostruire l’alb stesso (fig. 1) è stica negli arch ioteche nazion e di ambito loca e inedite all’inter opo l’alluvione d ra della somma g. 1). dal testo s uto nella notte d ed ha provocat err]e di gifuni e tale numero d ecie se rapporta giffoni sei casa stro (circa 5000 numero di fuoch era si descrivon ’esenzione fisca ale dei beni deg rtata la distruzio hiese, mulini e d ” (i.e., gualchier abilmente dislo che rappresen ua delle “intrate struzione è tal sostentamento è indicato nelle venienti dai “ba to è da conside e coeva all’e olli notarili men (2004) presso o. uno di essi è nel quale si con ndividuati all'intern rent talwegs in the alla letteratura (1994; in mil 1580 e con oni vallepiana, nziano i corsi irno, cavaioenti). nel sici geologiche del come “frana” i casali e gifmprecisato. al eale estensiobero filologico è stata avviata ivi di stato di nali di roma e ale. nel primo rno di una letdal marchese asi di to et di aali 0, hi no agli odi re oe o e aeo è fig. 4 conf del 30 luglio comparison after (right pa fig. 5 gli ef nalone "isca l isca longa st no di tre distinti ca e studied area. ferma la tobre 158 vittime “i novesi, p oltre che ogliara d di baron che in tu temente seguente evincono che hann fiumi irno spettivi l’accadim zione de menta, p tivi di leg distrutti, al mare. 700 del ronto dello stesso 2010. si nota la n of the same stra anel) the july 30, ffetti provocati da longa". tream; erosional/d analoni data l’ora d’iniz 81 alle 21.00 ci in partibus cast presso giffoni s e a salerno stes di salerno, e da nissi e nella città utta la zona si s posti nelle vicin e carestia di pa o anche le tipo no caratterizzato o e picentino c bacini, e le co mento di queste ei danni che inc ponti crollati ed gna ed altro ma unitamente a c il notaio fiore marchese del v o tratto del torren notevole quantità and of the prepe 2010 flood. note ll’azione erosiva depositional effec zio del nubifrag rca. le notizie d tilionis gifoni” (c sei casali) ed a ssa (p.e., 7 vittim anni presso la fr à di salerno). i sono avuti dann nanze dei corsi ane. dalla lettur ologie dei feno o l’evento, cioè con i loro afflue olate rapide d e ultime è desu clude case abb alberi abbattuti, ateriale derivant arcasse di anim riporta, infine, vasto. è possib te prepezzano, p di detrito deposit ezzano stream, be e the debris infillin della colata del 3 cts of the july 30, esposito g. & ga io, cioè il primo descrivono dann castiglione del g nche in altre zo me nella frazione razione acquam noltre, si ribadi ni ai mulini, evid d’acqua, con c ra del protocollo meni idrogeolo le esondazioni enti, le frane ne i fango o detr mibile dalla des battute dalle fon , e grossi quant te dai centri ab mali, trasportati 300 morti, cont bile, tuttavia, ch prima e dopo la co tato in alveo. efore (left panel) ng of the talweg. 30 luglio 2010, ne 2010 flood. alli p. o otni e geone, e di mela sce dencono si ogici dei ei ririto. scrindatitabitati fino tro i he il olata and el cala catastrofe idro primo si riferis re di castiglio nata esplicita mento, ment di sua giurisd sei casali. n tizzare che l mente quasi a corre vi sono quell costo (1613) bre del 1581 tano con num cati. in partico glione del ge tempesta… l gandovi da q con quanto ri comple dimostrano raggiunte dal ti che frane e suto antropic muni interess al fine d eventi nell’are te anche fon milone, 1998 quali si è evin verificato il 2 sia come fra dendo quindi dell’epoca (il riere della se far intendere fango o detrit time a giffoni del genovesi anche dalle i abitanti del po riferito che tut luoghi limitro monte monna sw), cioè dov transitate opp testimoni han volto nelle fr oltre agli eve sono stati ind termedio (tab dalle no l’elevata susc l’area di studi dicazione per tab. 1 catast 1581 al 1966 ( hydrogeologic from year 158 et al., 2009). ogeologica del 1581 sca a quanto ac one del genove amente al prin re il secondo tr dizione, ovvero nel qual caso, l’evento provoc 1000 vittime. do e sostegno le riportate dal , il quale narra vi fu un nubifra merosi danni e m olare, l’autore a enovesi, dicend lo rovinò e distr quattrocento pe portato dal nota essivamente, le le notevoli pro ll’evento e la gr e alluvioni hann co presente al sati dalla ricerca di individuare ult ea di studio, son nti specifiche re 8; porfido et nto che l’ultimo g 5/10/1966, clas na che come p i la ricerca su mattino, il mes era) sono emers l’accadimento d to che hanno pr sei casali ed u i. tale fatto è s interviste realizz osto (estate 201 tte e tre le vittim ofi ai canaloni a, su entrambi ve probabilment pure si sono es nno riferito che i rane era sia fa enti catastrofici d dividuati anche b.1). otizie storiche s cettibilità a colate io. tali notizie h r lo studio geomo trofi idrogeologich migale e milone, cal disasters occu 1 to 1966 (from m 1 nei monti picentini ccaduto nelle ter esi, da lui nom ncipio del docu ratti solo le terr quelle di giffon è possibile ipo cò complessiva di queste notizi contemporane che nel settem agio nel napole molti alberi srad accenna a cast do che tale “fier russe tutto, affo ersone”, in line aio fiore. e notizie storich oporzioni area ravità degli effet no avuto sul tes ll’epoca nei co a. teriori e/o simila no state consulta ecenti (migale & al., 2009), dall grave evento si ssificato nel sic piena. approfon alcuni quotidian ssaggero, il cor se notizie tali d di colate rapide d rovocato due vit una a castiglion stato confermat zate ad hoc ag 10), i quali hann me si trovavano i che incidono i versanti (ne te le colate son spanse. inoltre, il materiale coin ngo che detrito del 1581 e 1966 quelli occorsi n sopra descritte a e rapide di fango hanno costituito orfologico di seg he occorse nell’ar 1998; porfido et a urred within the inv migale and milone … riue ni oae o meiira oa e ali tsoari a& e è ci nni ra di te o gli o n il e o i no. 6, nel periodo inappare palese o o detrito nel una valida inguito illustrato. rea di studio dal al., 2009). vestigated area, e, 1998; porfido fig. 6 il po depositato da abitazioni alle the bridge ac 30, 2010 alluv fig. 7 (sini sinistra è cos que provenie lined canal a es (left pane opening of th le crit i r dall’inter rilievi di rapprese pregress detrito, a success reticolo i nuove co ma da p di evolv hungr e sporto in perché p riale soli categoria onte situato al ce alla colata del 30 e sponde del torre cross the prepezza vial flood. note the stra) una delle c stituita interamen enti dal versante, across the sieti b el). lined canal un he bridge (right pa ticità attual risultati dello s rpretazione aer terreno sono s entate le aree se (soil slip), ev alcune delle qu sivamente è st idrografico che olate, non nece articolari condiz vere in flussi i et al., 2001). q n massa che s presentano una do, portate di p a dei fenomen entro di prepezza 0 luglio 2010 sul f ente. zano stream in the e amount of mud-d canalizzazioni che te da abitazioni. sotto la strada ch basso village; not nder the sieti alt anel). li studio geomorf rofotogeologica sintetizzati in f interessate da volute in colate uali riferibili all tata evidenziata potrebbe esse essariamente al zioni idrologich perconcentrati uesti ultimi son si differenziano a minore conce picco minori, e n ni franosi; i loro ano di giffoni se fondo alveo. si n village of giffoni s debris infilling and e attraversa sieti (destra) il passa he collega sieti ba te the excessive t-sieti basso road 1 fologico deriva e dai succes fig. 2, ove si so a frane superfic rapide di fang ’evento del 15 a la porzione ere attraversata imentate da fra e e con possib (debris floods no fenomeni di o dai debris flo ntrazione di ma non rientrano n o depositi, inol i casali, con il d nota la vicinanza sei casali after the the big boulders. basso, la cui sp ggio riservato alle asso con sieti alto proximity of the h d; note the insuffi 183 ante ssivi ono ciali o o 581. del a da ane, ilità s in traows ateella ltre, etrito delle e july onda e aco. housficient 184 risultano me (hungr et al il dato studio – utile 1581 – è ch duate nei co cipriano pice mentre per g fig. 9 in sequ sa la frazione v struzzo a mont c il successivo cedente con qu different segm picentino villag segments insid fig. 8 due ca ne del genove two entombed note the insuff eno spessi e l., 2001). geomorfologico anche per la c e gran parte d omuni di castig entino attravers giffoni sei cas uenza, da a a d, vignale di san c te dell’abitato. in o tratto tombato. uello esterno all’a ments of the lined ge. a, concrete de the village. analoni tombati so esi. d canals under ficient opening of di granulome o più evidente comprensione d delle colate pre glione del geno sano tout cour i sali gli insediam sono rappresenta ipriano picentino b il tratto iniziale in d la tubatura abitato. d canal crossing canal uphill from otto la strada pro the calvanico ro the bridges. etria inferiore emerso dallo dell’evento del egresse indiviovesi e di san i centri abitati, menti ne sono ati i vari tratti del . in a vi è la cana e all’interno dell’a di by-pass che ra through the vign m the settlement ovinciale calvanic oad, near castig tizie nel debris fl pure dal senti ne in conse presenza delle ast foto aere canale che attrav alizzazione in cal bitato (cerchiato) accorda il tratto p nale di san cipria t. b-c-d, entomb co, presso castig glione dei genov solo parz parte del spondenz che la su zione per spondenz esse degli impl la coltre flussi rapi gli stessi stigata in duati depo essi sono calcareo-d limoso-sa volta, nell sono stat vrapposte stratificazi ricoperto precedent è stata ri attraversa contigue, espansi. t to dalle n riazione d contrato a demontan per tali aree s rimento co la & nigro (2004) ha comprese volumi tot singoli im picco di d (del prete dezza dim molto rapi demontan rale cana cità insuff limitrofe. n possono come già campania probabilm l’evento d colate ind possibile d quanto rideposti op posto in a con invece, so le quali è poss lows che si pos la mobilizzazio gli alvei (i.e., a eguenza di part a di detrito e s te torrentizie è ee e con il rilev verlce. in preano bed gliovesi. ialmente intere le frane è loc za degli impluv uscettibilità di i r i soil slip è m za di tali elemen endo spesso le uvi caratterizza superficiale, c idi che si incan fino al fondova molti canaloni ositi tipici dei de o costituiti da d dolomitico, ing bbiosa con tess ’ambito delle co te rilevate varie e di detrito, a d ione storica di ogni volta i su ti. la gran parte nvenuta all’inte ano i centri ab dove i flussi tale effetto può notevoli portate di pendenza che al sopraggiunge ne, rallentando b l’evento di sarn sono state stima omprese tra 1.5 o, 2001), mentr anno stimato e tra 0.6 x103 e tali di materiale mpluvi, hanno r diverse centinai e et al., 2006). mostrano che si idi ed energetic ni, possono abb lizzazione sopr ficiente ed espa nel caso in cui causare ingen à accaduto in a (sarno 1998 mente nell’area del 1581. tuttav dividuate nello s delimitare i corp -erosi nei talw ppure rielabora aree fortemente n l’analisi del re ono state tracci sibile il transito ssono sviluppa ne di detrito e accumulati da c ticolari condizio sedimenti mobi stata accertata vamento di cam esposito g. & ga essati. la magg calizzata in co i, a testimonian nnesco ed evo maggiore in co nti geomorfolog e testate o i fian ati dal distacco d con formazione nalano e seguo alle, nell’area in i sono stati ind ebris flows (fig. etrito eteromet lobato in mat situra caotica. t oltri di ricoprime e generazioni imostrazione d colate che han uoli sviluppati s e degli affiorame erno dei tratti c bitati e nelle a pregressi si so ò essere giustif solide e dalla e i flussi hanno ere nelle aree bruscamente. no, ad esempio ate velocità di sc 5 e 20.8 m/s (fa re zanchetta et portate mass e 3.4 x 103 m3 s e mobilizzato, p raggiunto valor a di migliaia di tali ordini di gr tratta di fenom ci che, nei tratti bandonare la na attutto se di ca andersi nelle a esse siano abit ti danni e vitt altre aree d 8, ischia 2006 di studio dura via, per molte d studio non è st pi deposizional weg dove si era ati perché mess urbanizzate. eticolo idrograf iate le aste torr o di futuri mud are da soil slip sedimenti già p colate precede oni idrologiche. ilizzabili all’inte a con l’analisi de mpagna, mentr alli p. gior orrinza oluorriici. nchi dele di ono nvedivi. 3). rico rice talento soella nno ulle enti che aree ono icavao inpeo, in coraelt al. ime s1; i per i i di m3 ranmeni peatuapaaree tate ime ella ) e ante elle tato i, in ano si in ico, rend or oppreenti) la erno elle re il la catastrofe idrogeologica del 1581 nei monti picentini … 185 probabile innesco di soil slip è stato ipotizzato considerando la localizzazione dei fenomeni pregressi, e dove non riconosciuti, in base alle caratteristiche pedologiche e geomorfologiche rilevate. in tutta l’area di studio, inoltre, si è verificato che un carattere predisponente all’innesco dei fenomeni di soil slip concerne l’uso del suolo. infatti, i versanti sono caratterizzati prevalentemente da specie vegetazionali le cui radici non esercitano un’azione di ancoraggio della copertura pedologica al substrato (castagneti, noccioleti ed uliveti), costituendo un peso ulteriore nel caso in cui i suoli raggiungano una condizione di saturazione (iovino, 2007). ulteriori elementi destabilizzanti sono risultate le numerose mulattiere che tagliano le coltri piroclastiche, i cui muri a secco di contenimento sono ormai spesso mal manotenuti o crollati. attraverso il rilevamento di campagna sono state rilevate anche una serie di criticità territoriali riscontrate presso gli abitati e legate ad aspetti relativi alla pianificazione territoriale. alcune di esse sono state evidenziate su tre stralci cartografici ricavati dalle carte inventario dei fenomeni franosi, realizzate dall’autorità di bacino destra sele nell’ambito del piano per l’assetto idrogeologico (pai) disciplinato dalla legge n. 267/98. a valle dello studio, inoltre, sono state consultate le cartografie del rischio prodotte dall’adb ed è stato verificato come si collocano le zone analizzate in tali elaborati. si rimanda al sito web dell’autorità di bacino destra sele (www.autoritabacino destrasele.it) per la visualizzazione delle cartografie citate. giffoni sei casali in questo comune ricadono i sottobacini idrografici dei torrenti prepezzano e sieti. il primo si presenta più ampio (ca. 20 km2) con una gerarchizzazione delle aste del quinto ordine, contro il terzo raggiunto da quello del sieti. in diverse aste secondarie del bacino di prepezzano sono stati individuati depositi di colate recenti, così come nello stesso alveo principale del torrente. in particolare, esso è stato interessato da un debris flow nella notte tra il 30 e 31 luglio 2010, durante il periodo di rilevamento (fig. 4). questo fatto ha permesso di osservare de visu gli effetti della colata, come la deposizione di fango e detrito su intere aree golenali in successivi tratti dell’alveo (fig. 4). i depositi hanno provocato la deviazione del corso d’acqua ed il danneggiamento della strada di fondovalle che lo costeggia fino al centro abitato della frazione prepezzano, causando la rottura dei muri di calcestruzzo adibiti alla difesa di sponda. lo scheletro del detrito depositato è compreso tra le ghiaie ed i blocchi (sino a 10 m3), sostenuti in matrice sabbiosa calcarea. il deposito, inoltre, ingloba rami ed alberi sradicati dalla colata alimentata dal trasporto attivatosi in diversi impluvi che drenano il versante ne del monte monna, ed in particolare da quello denominato “isca longa” (fig. 2). il rilevamento di tale impluvio ha permesso di appurare che l’evento è stato caratterizzato da processi di erosione di sponda e di fondo che hanno interessato il substrato calcareo-dolomitico (fig. 5). in particolare, l’erosione di sponda ha provocato numerose frane da crollo (cruden & varnes, 1996), i cui depositi stessi hanno costituito la componente più grossolana della colata, compresi i massi di svariate tonnellate. una notevole quantità del detrito prodotto è rimasta incassata nell’alveo stesso del canalone, senza essere trasferita al torrente prepezzano. tale situazione comporta che in occasione di un futuro evento pluviometrico sostenuto, tutto questo detrito può essere rimobilizzato in ulteriori colate. per comprendere le dinamiche dell’evento, presso l’abitato di prepezzano sono stati intervistati numerosi testimoni oculari della notte del 30 luglio 2010 che hanno confermato la notevole energia del flusso detritico, la cui altezza è giunta ad 1 metro dalla superficie dei ponti che collegano le due sponde del torrente (fig. 6). anche per quanto riguarda il bacino del sieti, in molte aste è stato individuato detrito eterometrico instabile così come i depositi di colate pregresse. in tale bacino i versanti sono ricoperti da coltri piroclastiche spesse e numerose sono le frane pregresse che caratterizzano la testata del bacino (fig. 11). in particolare, sono state notate sia da fotografie aeree che dal rilevamento di campagna diverse nicchie di distacco presso la testata dei valloni che caratterizzano sieti alto. in località “madonna del carmine”, invece, sono state individuate numerose colate i cui depositi risultano coalescenti, formando un unico corpo de posizionale (fig. 2). le criticità territoriali più importanti sono state rilevate nelle frazioni di prepezzano, sieti alto e sieti basso. la prima è attraversata dal torrente omonimo, le cui sponde ed il fondo alveo sono cementati, mentre numerosi sono gli attraversamenti stradali che collegano le zone abitate tra le due sponde (fig. 10). dal centro abitato, inoltre, ini fig. 10 stralcio modificato della carta inventario dei fenomeni franosi realizzata dall’autorità di bacino destra sele, relativa alla frazione prepezzano del comune di giffoni sei casali. nello zoom sono stati evidenziati gli attraversamenti stradali nell’area abitata, sotto cui sono stati individuati i depositi dei recenti debris flows. le aree in grigio sono colate cartografate dall’autorità di bacino destra sele. quelle delimitate dalle linee a tratteggio sono colate pregresse individuate nel presente studio. la linea scura è il torrente prepezzano. modified map from the landslide inventory map of the autorità di bacino destra sele (area of propezzano, giffoni sei casali municipality). note the road-crossing within the inhabited area, under which recent debris flows have been individuated. gray, flows reported by autorità di bacino destra sele. dashed lines envelop previous mud/debris flows identified in this study. bold line indicated the prepezzano torrent. esposito g. & galli p. 186 zia la strada che costeggia il torrente fino all’interno del relativo bacino, già danneggiata dalla colata del 30 luglio 2010. la criticità principale è rappresentata dalla vicinanza delle abitazioni alle sponde del torrente (figg. 6, 10) e dalla presenza dei ponti, la cui luce può essere ostruita da eventuali massi ed alberi che possono essere trasportati dalle colate. sieti basso condivide le stesse problematiche, oltre al fatto che alcuni canaloni di ridotte dimensioni attraversano direttamente l’abitato (fig. 7). per quanto riguarda sieti alto, l’abitato risulta più rilevato rispetto al torrente e quindi in una condizione di relativa sicurezza, mentre la strada che collega tale frazione con sieti basso attraversa uno dei canali che drenano i versanti per mezzo di un ponte; esso potrebbe costituire un pericoloso sbarramento al deflusso a causa della sua luce (fig. 7) evidentemente insufficiente per il drenaggio di flussi viscosi caratterizzati da elevate portate solide. per quanto riguarda il confronto con la cartografia adb realizzata nell’ambito del piano per l’assetto idrogeologico, tutto l’abitato di prepezzano rientra nelle aree a rischio frana (r1, r2, r3). per il rischio idraulico sono state definite a rischio (r1, r2, r3, r4) alcune fasce ristrette immediatamente a ridosso del torrente prepezzano che includono la strada di fondovalle, alcuni attraversamenti e qualche edificio ad uso pubblico o privato, mentre gran parte dell’abitato è escluso da tale rischio. riguardo al rischio colate, invece, nessuna porzione di prepezzano risulta classificata. gli abitati di sieti alto e sieti basso non risultano interessati dal rischio colate e nemmeno da quello idraulico, mentre lo sono per quel che riguarda il rischio frana (r1, r2, r3). castiglione del genovesi e san cipriano picentino in questi due comuni non sono presenti sottobacini, ma soltanto singoli impluvi che caratterizzano il versante occidentale del monte monna. in essi, nei tratti terminali prossimi alla rottura di pendenza a ridosso delle aree abitate, sono stati individuati gli affioramenti dei depositi di debris flows pregressi (fig. 3), oltre a detrito eterometrico sul fondo alveo. inoltre, nella zona pedemontana sono stati individuati anche depositi molto recenti franati lungo le strade durante gli ultimi eventi. molti blocchi sul fondo dei canaloni sono stati individuati anche più a valle del piede del versante, nei tratti più pianeggianti, a dimostrazione delle notevoli energie di trasporto che caratterizzano i flussi in arrivo dal monte monna. a castiglione del genovesi sono stati individuati due canaloni che all’intersezione con la strada provinciale calvanico subiscono restringimenti ad imbuto delle sponde (fig. 8). ma, di fatto, l’intero centro abitato costituisce uno sbarramento alle possibili colate a monte; l’impluvio principale che drena il monte monna attraversa l’abitato orientale in prossimità del palazzo comunale e dopo aver superato la suddetta provinciale passa sotto al paese (fig. 12) tramite una condotta di esclusiva funzionalità idraulica, ma non certamente adatta al drenaggio di colate detritiche o fangose. a questo si aggiunga la presenza di numerosi edifici sulle sponde dei canaloni, realizzati senza nessun margine di sicurezza dagli stessi. dalla consultazione della cartografia relativa al rischio colate contenute nel pai, l’abitato di castiglione del genovesi non è caratterizzato da tale rischio, mentre lo è interamente per quel che riguarda il rischio frane (r1, r2, r3). nel comune di san cipriano picentino, la frazione più esposta all’invasione di mud or debris flows è quella di vignale, posta in corrispondenza della rottura di pendenza del versante occidentale del monte monna. qui fig. 11 stralcio modificato della carta inventario dei fenomeni franosi realizzata dall’autorità di bacino destra sele, relativa alle frazioni sieti basso e sieti alto del comune di giffoni sei casali. nello zoom sono stati evidenziati i tratti tombati del torrente sieti. le aree in grigio sono colate cartografate dall’autorità di bacino destra sele. quelle delimitate dalle linee a tratteggio sono colate pregresse individuate nel presente studio. la linea scura è il torrente sieti. modified map from the landslide inventory map of the autorità di bacino destra sele (area of sieti basso and sieti alto, giffoni sei casali municipality). note the entombed segments of the sieti torrent. gray, flows reported by autorità di bacino destra sele. dashed lines envelop previous mud/debris flows identified in this study. bold line indicated the sieti torrent. la catastrofe idrogeologica del 1581 nei monti picentini … 187 sono stati analizzati i tratti finali dei canaloni che drenano il rilievo, riscontrando la presenza di depositi tipici da colata, anche recenti, e di detrito grossolano in alveo. la criticità più importante è la canalizzazione in calcestruzzo che è stata realizzata per incanalare le acque provenienti dal monte monna (figg. 9, 12). essa subisce un restringimento proprio a ridosso della zona abitata mentre, all’interno di essa, risulta tombata. da un sopralluogo fatto all’interno del tratto tombato, sono state rilevate ad oltre 2 metri di altezza le tracce del fango che ha attraversato il canale in tempi recenti. tale tratto sfocia in una tubatura metallica che convoglia i flussi in una canalizzazione di calcestruzzo, sulla cui sponda sinistra sono presenti dei condomini di recente costruzione. essa prosegue in località “inserteta” dove risulta tombata in corrispondenza degli attraversamenti stradali. dalla consultazione del pai non ci sono porzioni dell’abitato definite a rischio colate, mentre tutta la frazione vignale è a rischio frane (r1, r2, r3). come si evince dalle analisi delle cartografie del pai, in nessuno dei tre comuni ci sono aree definite a rischio colate mentre in tutti e tre sono state definite quelle a rischio frane. per determinare tale rischio, l’adb ha considerato la classificazione delle frane di cruden & varnes (1996), che include anche quelle da colata rapida di fango o detrito. ciò implica che è stato definito il rischio di colate che si possono evolvere da movimenti franosi e non di quelle innescate da particolari condizioni idrologiche, come la colata del 30 luglio 2010 a giffoni sei casali, che possono rivelarsi altrettanto distruttive. conclusioni l’approccio storico-geologico con cui è stato condotto lo studio ha evidenziato che l’area investigata è stata ed è attualmente esposta all’attraversamento ed espansione di mud or debris flows. i risultati ottenuti dalle ricerche storico-archivistiche hanno consentito di circostanziare gli effetti devastanti dell’evento del 1581 sugli abitati di castiglione del genovesi, san cipriano picentino e giffoni sei casali, con la morte di 700-1000 persone e la distruzione di gran parte dei manufatti e degli opifici. a caratterizzare l’instabilità dei versanti dell’epoca, ma a maggior ragione di quelli odierni, sono le coltri di ricoprimento costituite da ceneri e pomici variamente pedogenizzate e rimaneggiate. le loro caratteristiche tessiturali e mineralogiche permettono l’assorbimento di notevoli quantitativi di acqua, anche in tempi rapidi, con la conseguente diminuzione della resistenza al taglio dei materiali. ciò spiega l’accadimento delle frane in concomitanza di precipitazioni piovose intense, di breve o lunga durata, che nell’area di studio sono favorite dalla conformazione orografica del territorio. anche le caratteristiche geomorfologiche dell’area ne condizionano il meccanismo di innesco, in particolar modo a causa delle pendenze elevate dei versanti calcareo-dolomitici del monte monna (35°-45°) e le diverse discontinuità che ne interrompono la regolarità. è stato accertato, inoltre, che in occasione di particolari condizioni idrologiche l’area di studio potrebbe essere interessata da debris flows non innescati da movimenti franosi ma dal ruscellamento di grandi quantità di acqua che possono prendere in carico sedimenti fini e detrito localizzati lungo le aste di drenaggio, con la possibilità di evolvere in debris floods nel caso in cui aumentassero le portate liquide. la frazione prepezzano di giffoni sei casali è stata interessata da un tale fenomeno nella notte tra il 30 ed il 31 luglio 2010, rilevato attraverso il presente studio. a favorire l’invasione delle colate in aree urbanizzate vi è lo sviluppato reticolo idrografico che può fungere da via preferenziale per il transito dei flussi, capaci di esondare qualora le aste fossero ostruite oppure così strette da non permettere il deflusso regolare. dalla consultazione delle cartografie di dettaglio prodotte dall’autorità di bacino destra sele nell’ambito del pai è emerso che gli abitati oggetto di studio non risultano caratterizzati dal rischio di colate mentre tutti sono in gran parte caratterizzati dal rischio frane; quest’ultimo include anche le frane da colata rapida di fango o detrito. da tale osservazione si può dedurre che è stato considerato soltanto il probabile accadimento di colate che si possono innescare da movimenti franosi e non quello di fenomeni di trasporto in massa che possono evolvere da particolari condizioni idrologiche. durante lo studio, inoltre, sono state individuate numerose criticità territoriali che possono amplificare il rischio colate. infatti, diverse sono le abitazioni, anche di recente costruzione, realizzate a ridosso dei canaloni che drenano i versanti e nei quali è molto alta la probabilità che colate provenienti da monte si incanalino con il rischio di disalveare, come testimoniato dai depositi antichi rinvenuti in tali aree, soprattutto nel caso in cui la massa di fango e detrito fosse di ingenti proporzioni. il fig. 12 stralcio modificato della carta inventario dei fenomeni franosi realizzata dall’autorità di bacino destra sele, relativa ai comuni di castiglione del genovesi (sinistra) e san cipriano picentino, frazione vignale (destra). negli zoom sono evidenziati i tratti tombati dei canaloni che attraversano i centri abitati. le aree in grigio sono colate cartografate dall’autorità di bacino destra sele. quelle delimitate dalle linee a tratteggio sono colate pregresse individuate nel presente studio. modified map from the landslide inventory map of the autorità di bacino destra sele (left, area of castiglione del genovesi; right vignale of san cipriano picentino). note the entombed segments of the torrents which cross the settlements. gray, flows reported by autorità di bacino destra sele. dashed lines envelop previous mud/debris flows identified in this study. esposito g. & galli p. 188 disalveamento potrebbe essere causato dal restringimento delle canalizzazioni artificiali realizzate a monte ed all’interno degli abitati, così come i tratti tombati su cui sono state costruite strade, condomini e piazze. determinanti possono risultare anche i ponti aventi delle luci che il più delle volte potrebbero non essere idonee al passaggio di colate detritiche o fangose. nel complesso sono state individuate diverse situazioni di criticità simili a quelle di altri comuni della provincia già interessati da fenomeni idrogeologici catastrofici, come sarno, siano, e bracigliano. in tutta l’area sarebbero perciò necessari degli interventi di “messa in sicurezza”, sia in termini di difesa attiva che passiva. dalla consultazione del programma degli interventi realizzato dall’adb si è appreso che nell’area di studio sono previsti interventi strutturali e non strutturali volti alla mitigazione del rischio di frana e di quello idraulico. alla luce del presente studio, però, sarebbe opportuno valutare l’ipotesi di classificare come r4 le zone abitate caratterizzate dalle criticità rilevate, soprattutto quelle in cui sono presenti tratti tombati, dove la probabilità di transito e invasione delle colate è maggiore. inoltre, potrebbe essere rivista la pericolosità relativa alle colate che possono innescarsi da processi idrologici all’interno degli impluvi. studi specifici sarebbero necessari per la realizzazione e la messa a punto di una valida pianificazione di emergenza per la gestione degli eventi estremi che possono interessare l’area (esposito, 2009). in questo senso potrebbe essere realizzato un sistema di early warning per l’attivazione delle fasi di emergenza della pianificazione di protezione civile, attivando un monitoraggio con strumentazioni idonee a rilevare i parametri idrologici e geotecnici precursori dei mud or debris flows. ringraziamenti siamo grati al sig. catello lubrino dell’archivio di stato di napoli per averci aiutato nella lettura dei documenti originali. grazie anche a sabina porfido del cnriamc di napoli per la documentazione fornitaci. le critiche e i commenti di due esperti referee hanno consentito di rinforzare l’impalcatura del lavoro e indirizzare in modo più convincente le conclusioni. bibliografia amarotta a.r. (1994) l’alluvione nel salernitano. un’esperienza disattesa. fuorni (sa), arti grafiche boccia fuorni, salerno. asna (1581) partium della sommaria. 37 (v.n.), ff. 274-275. assa (1581) protocolli notarili di salerno, notaio geronimo fiore, 1581-1584. b. 4893. autorità di bacino destra sele (2011) piano per l’assetto idrogeologico, aggiornamento marzo 2011. www. autoritabacinodestrasele.it bisson m., pareschi m.t., zanchetta g., sulpizio r. & santacroce r. (2007) volcanoclastic debrisflow occurrences in the campania region (southern italy) and their relation to holocene-late pleistocene pyroclastic fall deposits: implications for large-scale hazard mapping. bulletin of volcanology, 70, 157-167. bonardi g., d’aargenio b. & perrone v. (1988) carta geologica dell’appennino meridionale (1:250 000). atti del 74° cong. soc. geol. d’it., 13-17 settembre 1988, sorrento (na). cascini l., cuomo s. & sorbino g. (2005) flow-like mass movements in pyroclastic soils: remarks on the modelling of triggering mechanisms. rivista italiana di geotecnica, 4, 11-31. costo t. (1613) del compendio dell’istoria del regno di napoli parte terza, giunti, venezia. cruden d.m. & varnes d.j. (1996) landslide types and processes. in: turner a.k.; shuster r.l. (eds) landslide: investigation and mitigation. transp. res. board, spec. rep. 247, 36-75. del prete r., bellini f. & del prete m. (2006) stima dei volumi mobilitabili dalle colate incanalate rapide delle coperture piroclastiche campane. giornale di geologia applicata, 3, 137-144. de vita p. & celico p.b. (2006) distribuzione delle coltri piroclastiche sui versanti carbonatici perivesuviani e suscettibilità a franare. giornale di geologia applicata, 3, 145-151. di crescenzo g. & santo a. (2005) debris slidesrapid earth flows in the carbonate massifs of the campania region (southern italy): morphological and morphometric data for evaluating triggering susceptibility. geomorphology, 66, 255-276. esposito g. (2009) studio geomorfologico del bacino del torrente madrasco (valtellina) ed analisi del rischio da colata fangoso detritica per l’abitato di fusine (so). il geologo dell’emilia-romagna, 36, 19-27. esposito e., porfido s. & violante c. (2004) il nubifragio dell'ottobre 1954 a vietri sul mare costa di amalfi, salerno. c.n.r., pubb. gndci n. 2870, 381 pp. faella c. & nigro e. (2001) effetti delle colate rapide sulle costruzioni. parte prima: descrizione del danno. parte seconda: valutazione della velocità d’impatto”. forum per il rischio idrogeologico in campania. fenomeni di colata rapida di fango nel maggio ’98. commissariato di governo per l’emergenza idrogeologica in campania. guadagno f.m. (2000) the landslides of 5th may 1998 in campania, southern italy: natural disasters or also man-induced phenomena?. journal of nepal geological society, 22, 181-187. guadagno f.m., fiorillo f., focaretta m., forte r. & revellino p. (2003b) alcune considerazioni sulle instabilità delle coperture piroclastiche campane. i congresso nazionale aiga, chieti, rendina ed., 493-508. guadagno f.m., forte r., revellino p., fiorillo f. & focareta m. (2005) geomorphology of the source areas of the flows involving the pyroclastic soils of campania (southern italy). geomorphology, 66, 237-254. hungr o., evans s.g., bovis m. & hutchinson j.n. (2001) review of the classification of landslides of the flow type. environmental and engineering geoscience, 7, 221-238. il mattino anno 74, del 26/10/1966. il messaggero anno 88, del 26/10/1966. il corriere della sera anno 90, del 26/10/1966. la catastrofe idrogeologica del 1581 nei monti picentini … 189 iovino f. (2007) analisi dell’uso del suolo e linee operative di gestione forestale sostenibile per mitigare la vulnerabilità del territorio di pizzo d’alvano (campania). quaderni del camilab, 2. migale l.s. & milone a. (1998) mud flows in pyroclastic deposits of the campania. first data from historical research. rassegna storica salernitana, 30, 15 (2), 235-271. peronace e., galli p. & scarascia mugnozza g. (2009) the decadence of the sambucina abbey (calabria, southern italy): geological and historical hints. geografia fisica e dinamica del quaternario, 32, 203-212. porfido s., esposito e., alaia f., molisso f. & sacchi m. (2009) the use of documentary sources for reconstructing flood chronologies on the amalfi rocky coast (southern italy). in: geohazard in rocky coastal areas ed. c. violante. geological society, london, special publications, 322i, 173-187. revellino p., guadagno f.m. & hungr o. (2006) criteri morfologici e modellazione dinamica nella valutazione della suscettibilità da frana lungo versanti carbonatici dell’appennino campano. giornale di geologia applicata, 3, 159-166. santacroce r., cioni r., marianelli p., sbrana a. & sulpizio r. (2008) age and whole rock-glass compositions of proximal pyroclastics from the major explosive eruptions of somma-vesuvius: a review as a tool for distal tephrostratigraphy. journal of volcanology and geothermal research, 177(1), 1-18. scandone p., sgrosso i. & vallario a. (1967) finestra tettonica nella serie calcareo silico marnosa lucana presso campagna (monti picentini, salerno). boll. soc. natur. napoli, 76, 247-254. sici-gndci (sistema informativo catastrofi idrogeologiche gruppo nazionale difesa catastrofi idrogeologiche) 2010 http://sici.irpi. cnr.it. soil survey staff (1999) soil taxonomy: a basic system of soil classification for making and interpreting soil surveys (2nd ed.). washington, dc: us department of agriculture soil conservation service. terribile f., basile a., de mascellis r., di gennaro a., mele g. & vingiani s. (2000) i suoli delle aree di crisi di quindici e sarno: proprietà e comportamenti in relazione ai fenomeni franosi. quaderni di geologia applicata, 7, 59-79. terribile f., basile a., de mascellis r., iamarino m., magliulo p., pepe s. & vingiani s. (2007) landslide processes and andosols: the case study of the campania region, italy. in soils of volcanic regions in europe, ed. arnalds, o. et al. springer verlag berlin heidelberg. 545-563. u.o. 2.38. (1998) relazione sull’attività svolta dall’u.o. dell’università di salerno dal 21/05/1998 al 5/07/1998, g.n.d.c.i. dip.ing.civ., università di salerno. vingiani s. & terribile f. (2007) soils of the detachment crowns of ischia landslides. italian journal of engineering geology and environment, 2, 51-63. zanchetta g., sulpizio r., pareschi m.t., leoni f.m. & santacroce r. (2004) characteristics of may 5-6, 1998 volcanocastic debris flows in the sarno area (campania, southern italy): relationships to structural damage and hazard zonation. journal of volcanology and geothermal research, 133, 377393.  ms. ricevuto il 18 gennaio 2011 testo definitivo ricevuto il 3 agosto 2011 ms. received: january 18, 2011 final text received: august 3, 2011 imp.carobene_cevasco una deformazione gravitativa profonda di versante all’origine del piano di oneto, val graveglia (appennino ligure) luigi carobene1 & andrea cevasco1 1dip.te.ris – dipartimento per lo studio del territorio e delle sue risorse, università di genova corso europa 26, 16132 genova (italy). (e-mail: carobene@dipteris.unige.it cevasco@dipteris.unige.it) riassunto: l. carobene & a. cevasco, una deformazione gravitativa profonda di versante all’origine del piano di oneto, val graveglia (appennino ligure). (it issn 0394-3356, 2007). viene espressa una nuova ipotesi sulla genesi del piano di oneto, ubicato in alta val graveglia (appennino ligure), sulla base di un riesame degli aspetti deducibili dalle carte geologiche e topografiche e dalle evidenze di terreno. il piano di oneto costituisce una fra le più ampie superfici pianeggianti nell’area dell’appennino ligure e, per tale peculiarità, è oggetto, da oltre un ventennio, di notevole interesse da parte di geologi e geomorfologi. interpretato come una forma epigea di origine prevalentemente carsica esso è stato definito a più riprese la più grande “dolina” esistente in liguria orientale ed attualmente l’area di pertinenza viene considerata e perimetrata quale “monumento naturale” nel piano del parco naturale regionale dell’aveto. tuttavia, la revisione dei dati a disposizione e l’analisi degli elementi morfologici sia alla macroscala che alla mesoscala forniscono, assieme alla presenza di diversi indizi geologici e morfotettonici, nuovi elementi di discussione in parziale contrasto con le interpretazioni che attribuiscono al carsismo un ruolo di primaria importanza nella genesi del piano di oneto. le osservazioni effettuate sulla litologia e struttura del substrato, sulla morfologia e sulla tettonica recente dell’area ci portano a proporre un modello secondo il quale la depressione deriverebbe da un fenomeno gravitativo profondo favorito dalla presenza di un substrato “plastico”, dalle faglie e dal sollevamento plio-quaternario. è stata, inoltre, scartata l’ipotesi del glacialismo quale causa d’origine del piano di oneto. abstract: l. carobene & a. cevasco, a deep-seated gravitational slope deformation as the genesis of the piano di oneto, val graveglia (ligurian apennines). (it issn 0394-3356, 2007). a new hypothesis on the genesis of the piano di oneto, located in the upper val graveglia (ligurian apennines) (fig. 1), on the basis of field studies and a re-examination of the features distinguishable in geological and topographical maps and aerial photographs. the piano di oneto is one of the largest flat areas of the ligurian apennines; interpreted as an epigeal form of prevalently carsic origin, it has been defined more than once as the largest existing “dolina” in eastern liguria (fig. 7). a review of the available data, an analysis of the morphological features at both the macroand mesoscale and various geological and morphotectonic characteristics provide a new basis for discussion. from a geological point of view (fig. 2) the area is characterised by formations associable with the val di vara supergroup (internal ligurids of various authors), divided into two main units, the underlying mt. porcile unit and the overlying mt. zatta unit (gottero unit of various authors). the former contains notable ophiolitic sequences (basalts, serpentinites), a volcano-sedimentary complex (ophiolitic breccias) and a sedimentary cover (mt. alpe jaspers, calpionelle limestones, palombini clays). a little to the east of the val graveglia – val di vara watershed, under the mt. porcile unit, lies the colli-tavarone formation (upper cretaceous – palaeocene), which consists of layered claystones interspersed with thin layers of siltites and calcarenites. various authors have studied the structure of this area, which is exceptionally complex. its complexity is evident in the cross section reported in fig. 3, the trace of which is visible in fig. 2. all the structural reconstructions made of the area underline the fact that there is no carbonatic mass under the piano di oneto. since the pliocene, the complicated structural situation described above has been subjected to extensional tectonics that have given it its peculiar morphostructural conditions and been the main underlying cause of landslides in this zone as in other parts of liguria. an analysis of the orientation of the hydrographic network and the watershed lines indicate their close dependence on the main neotectonic lines, which are oriented ene – wsw (56° 66°), nnw – sse (150°), n – s and e – w. it is possible to say that the majority of the geomorphological alignments correspond to fracture systems or plio-quaternary faults but not to the more ancient faults visible in fig. 2. in the area under study (fig. 6) there are morphological features (reverse slopes, bulges and landslides) that are specific signs of gravitational slope deformations. the studies carried out indicate that the genesis of the piano di oneto should be looked for in a “deep-seated gravitational slope deformation” caused by the high energy of the relief associated with the uplift of the zone and the high erosive capacity of the watercourses that have caused the deepening of the hydrographic network. given the above scenario, the depression under study could be interpreted as the filling up of a trench running parallel to the ridge (nw – se) with silty-clayey material washed down from the surrounding slopes (figs. 6 and 9). we believe that only its extension towards the wsw, where there seem to be calpionelle limestones, can be imputed to carsic and erosive phenomena. parole chiave: dgpv, morfotettonica, dolina, val graveglia, appennino ligure. keywords: dgsd, morphotectonics, dolina, val graveglia, ligurian apennines, italy. il quaternario italian journal of quaternary sciences 20(1), 2007 45-56 1. sintesi degli studi sull’area vengono di seguito forniti i principali aspetti descrittivi, morfologici, litologici e tettonici atti alla comprensione dell’area. viene inoltre esposta una sintesi sull’origine carsica dell’area. 1.1. inquadramento morfologico e litologico il piano di oneto è ubicato nell’alta val graveglia (appennino ligure), in prossimità dello spartiacque che la delimita dalla val di vara, ad una quota compresa fra 830 e 835 m. l’orografia della zona oggetto di studio, che com46 l. carobene & a. cevasco prende la porzione nord-orientale del bacino del t. graveglia ed il limite occidentale del bacino del t. vara (fig. 1), è caratterizzata da un tratto della dorsale compresa fra m. zatta (1404 m) e m. porcile (1249,5 m), orientata in direzione nno – sse (150°) e contraddistinta, procedendo verso sse, dai rilievi di m. prato pinello fig. 1 topografia semplificata del settore nord-orientale della val graveglia con ubicazione del piano di oneto. legenda: 1) linea spartiacque principale; 2) linee spartiacque secondari; 3) corsi d’acqua principali; 4) corsi d’acqua secondari; 5) isoipse (equidistanza 100 m); 6) ripiani entro depressioni; 7) culminazioni principali lungo gli spartiacque. simplified topography of the north-eastern sector of the val graveglia with the location of the piano di oneto. legend: 1) main watershed line; 2) secondary watershed lines; 3) main water courses; 4) secondary water courses; 5) contours (equidistance 100 m); 6) plains inside depressions; 7) main watershed summits. (1391 m), m. coppello (1061,6 m), m. chiappozzo (1126,5 m), quota 957,9 m, quota 977 m, m. biscia (991,1 m), quota 1000,7 m e m. porcile (1249,5 m) (non tutti visibili nelle figg. 1 e 5). ad ovest dello spartiacque (val graveglia) il corso d’acqua principale è rappresentato dal t. reppia, che scorre in direzione n s fra le pendici meridionali del m. zatta (posto a nord, fuori carta) e la località ponte lagoscuro dove, confluendo con il rivo orti, dà origine al t. graveglia. i tratti del corso d’acqua in direzione n – s (fig. 5) presentano netti cambi di direzione causati da un sistema di dislocazioni circa ene – oso (56° ÷ 66°). ad esse corrispondono diversi corsi d’acqua sul versante sinistro del t. reppia (rio casoni, rio prato, rivo orti). anche il crinale risente del citato sistema di dislocazioni, che provoca sia discontinuità planimetriche che altimetriche (fig. 5), le maggiori delle quali si trovano in prossimità del passo del biscia (q. 890,6 m). alla maggiore dislocazione del crinale sembra aver contribuito anche il lineamento, posto circa e – o (93°), evidenziato dall’allineamento di tratti rettilinei dei corsi d’acqua di rio soprano, rio prato e canale del biscia (figg. 1 e 5). nella parte più elevata del bacino del t. reppia i versanti si presentano assai scoscesi, i corsi d’acqua tendenzialmente rettilinei, fortemente incisi e ripidi; a valle dell’abitato di reppia, l’asta principale risulta ancora profondamente incisa fra versanti assai acclivi. ad e dello spartiacque (val di vara) il corso d’acqua principale è rappresentato dal t. vara, che per un ampio tratto scorre in direzione nno – sse fino alla località pietragrossa, dove curva repentinamente di 90° e prosegue il suo percorso in direzione ono – ene (gomito di origine tettonica legato ai sistemi di faglie sopra citati). alcuni affluenti sulla destra orografica del vara, fra i quali il rio coppello, il canale del biscia ed il rio freddo, drenano i ripidi versanti sottostanti lo spartiacque principale, esposti a ne, compresi fra m. coppello e m. porcile (fig. 1). in generale si osserva una stretta dipendenza fra lo sviluppo del reticolo idrografico e le caratteristiche di permeabilità dei litotipi presenti: in particolare esso appare ben sviluppato in corrispondenza delle formazioni a dominante pelit ica (argil le a palombini, formazione di colli/tavarone), tendenzialmente impermeabili; ben controllato da linee di frattura e/o di faglia nel caso di litotipi ofiolitici, ed assai poco evidente in corrispondenza di litotipi calcarei (calcari a calpionelle), dotati di permeabilità per fratturazione e carsismo. i versanti in sinistra idrografica del t. reppia presentano in generale profili assai irregolari, testimoni di un’evoluzione tormentata dovuta, da un lato, all’estrema eterogeneità litologica ed al complesso assetto geologico-strutturale, dall’altro agli effetti della tettonica recente (faglie e sollevamento), che ha condizionato in maniera evidente l’impostazione del reticolo idrografico ed ha determinato un’accentuata energia del rilievo. tali fattori sembrano aver avuto un ruolo fondamentale nella predisposizione al verificarsi di un elevato numero di fenomeni franosi, sia attivi sia quiescenti, nonché di deformazioni gravitative profonde di versante (dramis et al., 1985; sorriso-valvo, 1998; 1995) già segnalate in altre parti della liguria (marini, 1994; marini, 2002; regione liguria, 2002a; 2002b; federici et al., 2004). sotto il profilo geologico (fig. 2) l’area è caratterizzata dalla presenza di termini riconducibil i al supergruppo della val di vara (liguridi interne auctt.), suddivisi in due unità principali (abbate et al., 1980-92, galbiati & principi, 1990) fra loro sovrapposte: l’unità di m. porcile e la sovrastante unità di m. zatta (unità gottero auctt.). in particolare, per quanto riguarda la 47una deformazione gravitativa profonda ... prima, sono rappresentate le note sequenze ofiolitiche (basalti, serpentiniti), il complesso vulcano-sedimentario (brecce ofiolitiche) e le coperture sedimentarie (diaspri di m. alpe, calcari a calpionelle, argille a palombini) che riflettono l’evoluzione del dominio ligure interno fra il giurassico medio-superiore ed il cretaceo inferiore. in prossimità del limite nord-orientale del bacino del t. graveglia si sovrappone alla precedente l’unità di m. zatta, qui rappresentata dall’insieme delle formazioni degli scisti della val lavagna e delle arenarie di m. gottero (cretaceo sup. – paleocene), costituite rispettivamente da torbiditi pelitico-arenacee e da potenti sequenze di torbiditi arenacee. poco ad e dello spartiacque val graveglia val di vara, al disotto dell’unità di m. porcile, compare la formazione di coll i-tavarone (cretaceo sup. – paleocene), ascrivibile all’unità di colli-tavarone (meccheri et al., 1986, marroni & meccheri, 1993), costituita da argilliti fogliettate con sottili intercalazioni di siltiti e calcareniti (questa unità era citata come “sedimentario esterno” in galbiati, 1970). 1.2. le precedenti indagini e ipotesi sulla genesi dell’area il piano di oneto, per le sue dimensioni notevoli, è ben individuabile nella cartografia geologica disponibile per tale zona alla scala 1:25.000 (decandia & elter, 1972; abbate et al., 1980-92; regione liguria, 2006). la peculiare morfologia della zona, unitamente alla scarsità di aree pianeggianti di una certa estensione a quota elevata in liguria, aveva attirato già dal 1939 l’attenzione di rovereto che ne effettuò una prima descrizione. solo nel 1968 furono studiati i dettagli morfologici superficiali (cozzani, 1968) e, contemporaneamente, ci si pose il problema dell’identificazione del percorso delle acque infiltrate nell’inghiottitoio principale (maifredi & giammarino, 1968). secondo questi ultimi, che effettuarono prove mediante traccianti, le acque non tornerebbero alla luce presso la sorgente di cà freghè (situata in corrispondenza dell’adiacente rivo orti, fig. 1) come ritenuto localmente bensì, con buona probabilità, in corrispondenza di risorgenti (peraltro, allo stato attuale, non ancora identificate) in val di vara. poco più tardi, alcune indagini geofisiche permisero di ottenere una prima indicazione sull’andamento del substrato in corrispondenza del piano (maifredi & pastorino, 1972). in particolare le indagini, che consistettero in sondaggi elettrici verticali e nella costruzione di una carta delle isoresistive, evidenziarono una morfologia sotterranea assai peculiare, caratterizzata dalla presenza di un ripido imbuto il cui fondo, a profondità superiore a 70 m, non corrisponde all’inghiottitoio attivo, situato nel settore nord-orientale della depressione. secondo gli autori, in corrispondenza dell’inghiottitoio (fig. 4) che si apre nei depositi di riempimento della depressione, il substrato calcareo si trova ad una profondità di 12 m. una recente campagna di indagini geofisiche (brandolini et al., 2005) sembra confermare i risultati delle indagini di cui sopra, pur riducendo a pochi metri lo spessore del sedimento detritico in corrispondenza dell’inghiottitoio attivo (fig. 4). nel modello di brandolini et al., 2005 il fondo della depressione non è “a imbuto” come in maifredi & pastorino (1972), ma allungato irregolarmente e ubicato in una diversa posizione; la sua profondità non sembra superare i 40 – 50 m. 48 fig. 2 schema geologico del settore nord-orientale della val graveglia (da galbiati, 1970; ridisegnato). legenda: 1) arenarie di m. gottero, formazione della val lavagna; 2) argille a palombini; 3) calcari a calpionelle; 4) diaspri; 5) basalti e brecce associate; 6) serpentiniti, gabbri e oficalciti; 7) formazione di colli-tavarone; 8) ubicazione delle depressioni studiate; 9) contatti tettonici di maggiore evidenza; a) faglia di trambacco; b) faglia di costa ricasola; 10) sovrascorrimenti; 11) traccia di sezione geologica. geological scheme of the north-eastern sector of the val graveglia (based on galbiati, 1970; redrawn). legend: 1) mt. gottero sandstones, val lavagna formation; 2) palombini clays; 3) calpionelle limestones; 4) jaspers; 5) basalts and associated breccias; 6) serpentinites, gabbros and ophicalcites; 7) colli-tavarone formation; 8) position of the plains studied; 9) most visible tectonic contacts; a) trambacco fault; b) costa ricasola fault; 10) thrusts; 11) trace of geological section. l. carobene & a. cevasco 49 2. assetto tettonico-strutturale antico e recente 2.1. gli aspetti strutturali sotto il profilo strutturale l’area, caratterizzata da una notevole complessità, è stata indagata in varie fasi da diversi autori (decandia & elter ,1969 e 1972; nosengo, 1970; galbiati 1970 e 1977; più recentemente da abbate et al., 1980; marroni, 1990; marroni & meccheri, 1993). nonostante ciò, esistono a tutt’oggi divergenze fra le ricostruzioni dei rapporti stratigrafici e tettonici tra le diverse unità presenti. sembra, tuttavia, accertata l’esistenza di una megastruttura coricata (parzialmente visibile in fig. 3) che si sviluppa per tutta la val graveglia con un’estensione di circa 5 km e coinvolge i termini dell’unità di m. porcile compresi fra le ofioliti e le argille a palombini. la cerniera di tale struttura, affiorante sulle pendici orientali di m. chiappozzo, è caratterizzata da un asse orientato circa 140°/15° no e da un piano assiale orientato circa 138°/12° so (marroni, 1990). il fianco diritto è osservabile nei dintorni di reppia e sulle pendici occidentali di m. chiappozzo, mentre il fianco rovesciato affiora in corrispondenza di costa ricasola (crinale a e del colle ricasola, fig. 1), lungo la valle del torrente reppia e ad e di m. chiappozzo. tale struttura, caratterizzata da numerose “drag folds” di notevoli dimensioni e deformata in antiformi e sinformi, è delimitata, verso e, da un piano di sovrascorrimento (figg. 2 e 3) che separa l’unità di m. porcile dall’unità di colli-tavarone mentre a ovest scompare sotto l’unità di m. zatta (marroni, 1990). secondo galbiati & principi (1994) l’area sulla quale è impostato il piano di oneto corrisponde ad una depressione strutturale delimitata, sia sul fianco settentrionale che su quello meridionale, da faglie dirette orientate circa oso ene (faglia di trambacco e faglia di costa ricasola, fig. 2). la notevole complessità sotto il profilo geologicostrutturale è evidenziata dalla sezione riportata in fig. 3 (galbiati, 1970), la cui traccia è visibile in fig. 2. in ogni caso tutte le ricostruzioni strutturali effettuate nell’area mettono in evidenza che in corrispondenza del piano di oneto non esiste un massiccio carbonatico. 2.2. la neotettonica al complicato assetto strutturale cui si è fatto sinteticamente cenno si sono sovrapposti, a partire dal pliocene, gli effetti della tettonica recente che ha determinato condizioni morfostrutturali peculiari divenendo anche in questa zona, come già in altre parti della liguria, la causa predisponente principale della franosità. già da tempo diversi studi (fanucci & nosengo, 1979; nosengo, 1979) hanno evidenziato l’esistenza di motivi strutturali distensivi che interessano il versante marittimo dell’appennino sotto forma di linee tettoniche subverticali con andamento sia longitudinale sia trasversale alla catena, che viene suddivisa in “blocchi” ad evoluzione indipendente, legati al sollevamento plioquaternario dell’area. al fine di definire il quadro morfotettonico alla scala locale, è stato realizzato uno studio dei principali elementi morfologici (forma del reticolo idrografico, gomiti lungo i corsi d’acqua, andamento rettilineo degli spartiacque principali, salti altimetrici lungo i crinali, selle principali, lineamenti), i risultati del quale sono fi g. 3 s ez io ne g eo lo gi ca f ra il t . r ep p ia e il t . v ar a (la t ra cc ia è in d ic at a in f ig .2 ) (d a g al b ia ti, 1 97 0; r id is eg na ta ). le ge nd a: 1 ) a rg ill e a p al om b in i; 2) c al ca ri a c al p io ne lle ; 3) d ia sp ri; 4 a) b as al ti; 4 b ) b re cc e of io lit ic he ; 5 a) g ab b ri e of ic al ci ti; 5 b ) s er p en tin iti e o fic al ci ti; 6 ) f or m az io ne d i c ol lita va ro ne ; 7 ) f ag lie e c on ta tt i t et to ni ci . g eo lo gi ca l s ec tio n b et w ee n th e r ep p ia a nd v ar a to rr en ts (t he t ra ce is in d ic at ed in f ig . 2 ) ( fr om g al b ia ti, 1 97 0; r ed ra w n) . l eg en d : 1 ) p al om b in i c la ys ; 2 ) c al p io ne lle l im es to ne s; 3 ) j as p er s; 4 a) b as al ts ; 4 b ) o p hi ol iti c b re cc ia s; 5 a) g ab b ro s an d o p hi ca lc ite s; 5 b ) s er p en tin ite s an d o p hi ca lc ite s; 6 ) c ol lita va ro ne f or m at io n; 7 ) f au lts a nd t ec to ni c co nt ac ts . una deformazione gravitativa profonda ... 50 riportati in fig. 5. l’analisi dell’orientazione del reticolo idrografico e delle linee spartiacque indica, in particolare, una stretta dipendenza fra essi e le principali direttrici tettoniche. in particolare i motivi tettonici principali sono rappresentati da direttrici ene – oso (56° ÷ 66°), nno – sse (150°), n – s ed e – o. si ritiene che gran parte dei lineamenti individuati su base geomorfologica corrispondano a sistemi di fratture o di faglie plio-quaternarie non corrispondenti alle faglie antiche visibili in fig. 2. i rapporti fra i principali sistemi sono assai complessi avendo essi, con ogni probabilità, giocato in tempi differenti. nell’area in esame esse individuano almeno due “blocchi” principali indipendenti; il limite occidentale dei “blocchi” coincide con il sistema di lineamenti che hanno condizionato il corso del t. reppia, mentre quello orientale è determinato dal sistema di lineamenti nno-sse da ubicare a e dello spartiacque (val di vara). in particolare un primo blocco (a, fig. 5), comprendente parte del tratto di crinale fra m. chiappozzo e m. coppello, è limitato verso n da una faglia diretta ene-oso (n63°) (evidente cambio di direzione del t. reppia a monte dell’abitato omonimo, cambio di direzione e salto altimetrico del crinale m. coppello – m. chiappozzo, brusco cambio di direzione del rio coppello, affluente del vara) e da una linea tettonica in direzione e – o (cambio di direzione di rivi minori); verso s il blocco è limitato dall’interazione di faglie dirette ene – oso (n68°) ed e – o (doppio gomito del corso del t. reppia, tratto rettilineo del rio prato, brusco salto altimetrico del crinale del m. chiappozzo, tratto rettilineo del canale del biscia). un secondo blocco (b, fig. 5), centrale, è delimitato verso n dal sistema sopra citato e verso s dalla linea tettonica orientata ene – oso (n56°), di importanza regionale, lungo la quale è impostato il corso del t. graveglia e quello del rivo orti. la porzione meridionafig. 4 carta geologica dell’area del piano di oneto con isopache (base geologica da abbate et al., 1980-92; ridisegnata e integrata da dati di terreno; isopache dei sedimenti nell’area indagata da brandolini et al., 2005, ridisegnato). legenda: 1) coperture detritiche quaternarie; 2) argille a palombini; 3) calcari a calpionelle; 4) diaspri; 5) ofioliti e brecce associate; 6) formazione di colli-tavarone; 7) faglie e contatti tettonici; 8) strati a polarità incerta; 9) strati diritti; 10) assi di pieghe; 11) isoipse del piano di oneto (equidistanza 2 m); 12) inghiottitoio; 13) isopache dei sedimenti. geological map of the area of the piano di oneto with isopachs (based on abbate et al., 1980-92; redrawn and integrated with new field data; sediment isopachs of the area studied by brandolini et al., 2005, redrawn). legend: 1) quaternary detrital cover; 2) palombini clays; 3) calpionelle clays; 4) jaspers; 5) ophiolites and associated breccias; 6) colli-tavarone formation; 7) faults and tectonic contacts; 8) beds with uncertain polarity; 9) beds with normal polarity; 10) fold axes; 11) contours of the piano di oneto (equidistance 2 m); 12) sinkhole; 13) sediment isopachs. l. carobene & a. cevasco 51 fig. 5 carta della tettonica post-compressiva legata al sollevamento isostatico plio-quaternario. legenda: 1) linee tettoniche; 2) corsi d’acqua principali; 3) linee di rottura del versante dovute alla deformazione gravitativa profonda; 4) discontinuità altimetriche importanti di crinale; 5) tratti ad andamento rettilineo dello spartiacque; il tratto a n si riferisce all’allineamento m. chiappozzo – m. prato pinello (fuori carta); 6) gomiti fluviali principali; 7) selle principali; 8) ripiani; 9) area interessata dalla deformazione gravitativa profonda. map of the post-compressive tectonics associated with the plio-quaternary isostatic rise. legend: 1) tectonic lines; 2) main water courses; 3) rupture lines due to deep-seated gravitational slope deformation (dgsd); 4) main altimetric ridge discontinuities; 5) rectilinear watershed trend tracts; the northern tract refers to the mt. chiappozzo – mt. prato pinello alignment (off map); 6) main river bends; 7) main saddles; 8) plains; 9) area affected by the dgsd. le del blocco, che comprende la dorsale di m. ricasola, è interessata da una serie di “superfici di rottura”, che testimoniano un’espansione del versante verso oso, riconoscibili da evidenze morfologiche (corsi d’acqua, selle, contropendenze e ripiani). gli effetti sopra esposti si sovrappongono a quelli di una faglia antica ad elevata inclinazione (direzione n71°), denominata “faglia di costa ricasola”, responsabile del ribassamento delle formazioni dei calcari a calpionelle e delle argille a palombini rispetto ai basalti ed alle brecce di m. capra. la porzione settentrionale dello stesso blocco pare inoltre aver subito un maggiore spostamento verso una deformazione gravitativa profonda ... oso. in fig. 5 si può ancora osservare che anche lo spartiacque val graveglia val di vara, nel tratto compreso fra m. chiappozzo e quota 977,0 m, appare coinvolto in tale spostamento. le evidenze morfologiche, in questo caso, sono costituite da notevoli discontinuità altimetriche del crinale e dalla presenza di due selle (rispettivamente sella a s del colle del chiappozzo e sella in corrispondenza del passo del biscia) che isolano il rilievo di quota 957,9 m. 3. caratteri morfologici del versante il versante lungo il quale è ubicata la depressione del piano di oneto (fig. 6) si sviluppa fra lo spartiacque val graveglia – val di vara (rilievo a quota 957,9 m) ed il torrente reppia, che scorre in questo tratto ad una quota di circa 350 400 m. esso presenta pertanto un dislivello pari a circa 550 m ed un’inclinazione media pari a circa 12° considerando la distanza fra la linea spartiacque ed il fondovalle pari a circa 2,6 km. il profilo del versante risulta irregolare (paragr. 1.1.), anche per la presenza di fenomeni franosi sia attivi che quiescenti (provincia di genova, 2003; fig. 6); procedendo da monte gli elementi morfologici salienti sono i seguenti: a) rilievo a quota 957,9 m (argille a palombini): è delimitato verso n e verso s da due selle. esso si trova sull’allineamento m. biscia – m. porcile (fig. 5), costituito da cinque culminazioni principali del crinale: 957,9 m – 977,0 m – 991,1 m – 1000,7 m 1249,5 m; esso risulta “disassato” rispetto all’allineamento m. chiappozzo (1126,5 m) – m. prato pinello (1390,6 m) (come si è detto al paragrafo 1.1.); b) depressione del piano di oneto (substrato costituito da argille a palombini, calcari a calpionelle, basalti e brecce ofiolitiche): la depressione presenta un perimetro irregolare, lungo 1140 m, coincidente con la base dei versanti circostanti, una superficie leggermente inferiore a 0,1 kmq ed allungamento in direzione ne – so (fig. 5 e fig. 7). il punto maggiormente depresso è situato a quota 829,5 m in prossimità del margine sud-occidentale, in corrispondenza di un “inghiottitoio” attivo. la quota massima del ripiano, pari a 835, 3 m, si trova a ne. i versanti circostanti presentano inclinazioni assai varie ed in particolare essi risalgono ripidamente (38°) sia verso s, fino alla dorsale di m. ricasola, sia verso ne (23°), fino al rilievo di quota 957,9 m; appare decisamente più blanda (13°) l’inclinazione media del versante a w della depressione. il piano di oneto raccoglie le acque di un rivo a carattere torrentizio che lo attraversa in direzione circa e – o (fig. 1). poco a n della depressione, a quote comprese fra 840 ed 850 m, è presente una seconda superficie subpianeggiante con caratteri morfologici assai simili, anche se di dimensioni inferiori, rispetto alla precedente. in questo caso il perimetro è di circa 800 m e la superficie pari a circa 0,033 kmq; c) rilievo a quota 870,0 m (calcari a calpionelle): è interessato, lungo il versante occidentale, da una grande frana i cui depositi si rinvengono fra 810 m e 475 m (decandia & elter, 1972; abbate et al., 1980; provincia di genova, 2003); i cigli di distacco si trovano a quota di circa 825 m (provincia di genova, 2003; federici et al., 2004; fig. 6); d) ampia superficie subpianeggiante a quota 600 m ca. (substrato costituito da serpentiniti, gabbri, oficalciti) sulla quale è stato costruito l’abitato di arzeno: è caratterizzata dalla presenza di estese coperture detritiche di origine franosa, frutto di riattivazioni in diverse fasi di un originario scorrimento rotazionale evoluto successivamente in colata (secondo federici et al., 2004); e) scarpata fra la superficie di cui al punto precedente ed il t. reppia (argille a palombini, calcari a calpionelle). si tratta di un versante ad elevata acclività, sede di fenomeni franosi causati da erosione spondale da parte del t. reppia. 4. discussione alla luce del quadro di riferimento delineato nei paragrafi precedenti si espone una serie di elementi che contrastano con le interpretazioni che attribuiscono al carsismo un ruolo determinante nella genesi del piano di oneto. già maifredi & pastorino, (1974) avevano espresso la perplessità che l’area costituisse una “situazione ideale per la formazione di una dolina tipica”. in particolare gli aspetti che, in questo caso, riteniamo differenti rispetto a quelli che permettono la formazione delle classiche doline riguardano: il contesto topografico-morfologico: le doline si formano, in genere, su massicci calcarei subpianeggianti (altopiani carsici) in contesti che permettano la permanenza e la successiva, lenta, infiltrazione delle acque superficiali (nel caso in esame il contesto è, invece, di versante). le dimensioni e la profondità: le notevoli dimensioni della depressione, in questo caso, richiederebbero l’esistenza, in profondità, di un corpo carbonatico di rilevante spessore interessato da carsismo ipogeo. la natura del substrato: come visto precedentemente, il ripiano si estende in prossimità del contatto fra litotipi ofiolitici (basalti) e coperture sedimentarie (brecce ofiolitiche, calcari a calpionelle, argille a palombini). l’ipotesi più verosimile, per quanto riguarda l’estensione dei litotipi al disotto della copertura detritica (figg. 8 e 9), prevede la presenza, lungo il margine meridionale della depressione, dei basalti e delle brecce ofiolitiche, lungo il margine occidentale dei calcari a calpionelle e delle argille a palombini, mentre lungo i margini settentrionale ed orientale delle argille a palombini. la posizione “anomala” dell’inghiottitoio superficiale rispetto sia al punto di massimo spessore del riempimento sia rispetto al centro del ripiano (fig. 4): la peculiare morfologia sotterranea del substrato indicherebbe il maggiore approfondimento (fino a 50 70 m) in prossimità del margine ne del piano (anziché in corrispondenza del centro della depressione); inoltre, in corrispondenza dell’inghiottitoio esistente, situato al margine so, lo spessore dei detriti sarebbe al massimo dell’ordine di 10-12 m (maifredi & pastorino, 1972) e, secondo brandolini et al. (2005) di soli pochi metri. la tipologia dei depositi di riempimento: la depressione è interamente riempita da materiale colluviale con forte componente argillosa, che non può favorire ma solo ostacolare lo sviluppo di carsismo; esso proviene dal dilavamento dei versanti circostanti, costituti da litotipi argillosi ed ofiolitici (argille a palombini, basalti, 52 l. carobene & a. cevasco brecce ofiolitiche). oltre alle considerazioni sopra esposte, a sfavore dell’origine carsica, vi è la presenza del ripiano esteso poco a n, assai simile sotto il profilo morfologico al piano di oneto, il substrato del quale risulta inequivocabilmente essere costituito solamente dalle argille a palombini. infine, prendendo in esame altre ipotesi, non sembra possibile che la genesi della depressione sia in qualche modo riconducibile al modellamento glaciale a causa della quota, ridotta, della zona (830 m). essa infatti, risulta inferiore sia al limite delle nevi persistenti nel würmiano, situato nell’appennino ligure orientale attorno a 1600 m, sia al limite inferiore raggiunto dalle lingue glaciali, pari a 1050 m ca. (rovereto, 1939). le osservazioni effettuate indicano che la genesi 53 fig. 6 carta della tettonica post-compressiva legata al sollevamento isostatico plio-quaternario e delle forme connesse alla dgpv (particolare della fig. 5). legenda: 1) linee tettoniche; 2) spartiacque principale; 3) spartiacque secondari; 4) linee di rottura del versante dovute alla deformazione gravitativa profonda; 5) fronti dei principali accumuli franosi; 6) rigonfiamenti del versante con contropendenza a monte; 7) discontinuità altimetriche di crinale; 8) andamento rettilineo di creste; 9) gomiti fluviali principali; 10) selle principali; 11) ripiani; 12) faccette triangolari; 13) inghiottitoio; 14) traccia di sezione geologica. map of the post-compressive tectonics associated with the plio-quaternary isostatic rise and the forms associated with the dgsd (detail of fig. 5). legend: 1) tectonic lines; 2) main watershed; 3) secondary watershed; 4) slope rupture lines due to dgsd; 5) main landslide accumulation fronts; 6) slope bulges with reverse slops; 7) altimetric ridge discontinuities; 8) rectilinear ridge trend; 9) main river sharps; 10) main saddles; 11)plains; 12) triangular facettes; 13) sinkhole; 14) trace of geological section. una deformazione gravitativa profonda ... della forma in oggetto debba essere ricercata in una deformazione gravitativa profonda di versante causata dalla vivace energia del rilievo connessa al sollevamento della zona, nonché dall’elevata capacità erosiva dei corsi d’acqua che ha determinato un forte approfondimento del reticolo idrografico. un ruolo favorevole allo sviluppo del movimento gravitativo potrebbero aver avuto le due faglie (in corrispondenza del rio prato e del rivo orti, fig. 5) agendo, in particolare, come “linee di svincolo” del blocco interessato. nell’area in esame (figg. 5 e 6) non mancano le evidenze morfologiche (contropendenze dei versanti, rigonfiamenti e movimenti franosi) che sono peculiari indizi delle deformazioni gravitative profonde di versante (sorrisovalvo, 1979; 1988). in particolare, altri evidenti indizi morfologici di dgpv, che implicano volumi rocciosi di varia entità, sono presenti lungo i versanti che degradano dallo spartiacque sia verso la val graveglia (a ese di m. chiappozzo e a n di case soprane, all’interno del blocco a, e più a s in prossimità di statale), sia verso la val di vara (a ene di m. coppello, parzialmente visibile in fig. 5). in riferimento al versante in oggetto, delimitato all’interno del “blocco b” (figg. 5 e 6), il complicato assetto strutturale determina condizioni assai varie che in molti casi danno origine alla sovrapposizione fra ammassi rocciosi a differente comportamento meccanico. l’aspetto principale, tuttavia, è legato al fatto che il “blocco” è caratterizzato, per la quasi totalità della sua estensione, dalla presenza di un substrato “plastico” costituito dalle argille a palombini (fig. 3) al quale, anche se con modalità diverse, sono sovrapposti ammassi rocciosi di varia natura a comportamento “rigido” (serpentiniti, basalti, brecce ofiolitiche, diaspri, calcari a calpionelle). in relazione alle proprietà meccaniche delle argille a palombini, prove geotecniche eseguite sulla stessa formazione in casi di studio sull’appennino modenese e reggiano (cancelli et al., 1987) hanno messo in evidenza un comportamento geotecnico tipico delle terre argillose di plasticità medio-alta e tendenza al rigonfiamento mentre, per quanto riguarda l’angolo di attrito, sono caratterizzate da valori di picco relativamente elevati (38° – 39°) e valori residui piuttosto bassi (10°-12°). per tali formazioni è noto, tuttavia, che elevate pressioni interstiziali possono giustificare l’innesco di frane e, nel lungo termine, la stabilità di versanti già dissestati dipende dai valori dell’angolo di resistenza residuo che, come sopra illustrato, è assai ridotto per tali litotipi. il modello di deformazione che si può ipotizzare costituisce una base di lavoro che tende inevitabilmente a schematizzare le condizioni reali, ben più complesse. esso presuppone l’esistenza di deformazioni plastiche in corrispondenza delle argille a palombini, private del contrasto laterale in conseguenza dell’approfondimento del solco di fondovalle, lungo orizzonti profondi di maggiore debolezza. entro tali fasce andrebbero a radicarsi numerose discontinuità di neoformazione (denominate in precedenza “superfici di rottura”, fig. 6) che avrebbero contribuito in varia maniera allo smembramento ed all’espansione del versante verso oso. queste ultime, particolarmente evidenti nella zona meridionale del blocco, in corrispondenza degli ammassi a comportamento rigido (ofioliti e brecce ofiolitiche), tendono a perdere la loro continuità nella porzione settentrionale dello stesso, laddove le condizioni strutturali determinano l’affioramento in superficie degli ammassi a comportamento “plastico”. non è noto, allo stato attuale, se al movimento abbia contribuito la presenza della superficie di sovrascorrimento fra l’unità di m. porcile (argille a palombini) e l’unità di colli-tavarone (formazione di collitavarone) (fig. 3), immergente verso ovest e disposta, quindi, sfavorevolmente alla stabilità. a tale riguardo le evidenze morfologiche sembrerebbero indicare uno spostamento del crinale (tratto fra la sella a s di m. chiappozzo e il passo del biscia) ma l’effetto potrebbe essere dovuto all’arretramento dello stesso a causa dell’intensa erosione che interessa la testata della val di vara. detta superficie di sovrascorrimento, tuttavia, potrebbe aver rivestito un ruolo fondamentale sotto il profilo idrogeologico, costituendo una via preferenziale di infiltrazione e scorrimento idrico in profondità. nell’ottica prospettata, la depressione del piano di oneto può essere interpretata come il riempimento di un trench, con allungamento parallelo al crinale (no – se), colmato da materiale limoso argilloso derivante dal dilavamento dei versanti circostanti. riteniamo che solo il suo allargamento verso oso, dove sembra accertata la presenza nel sottosuolo dei calcari a calpionelle, potrebbe essere imputato a fenomeni carsici ed erosivi. ringraziamenti si ringrazia il dott. marino sorriso-valvo per la revisione critica del manoscritto. 54 fig. 7 il piano di oneto (vista da nw). e’ visibile, sulla sinistra, la dorsale di costa ricasola. the piano di oneto (from the nw). the ridge of costa ricasola is visible on the left. l. carobene & a. cevasco 55 fi g. 8 s ez io ne g eo lo gi ca t ra sv er sa le d el p ia no d i o ne to ( la t ra cc ia è s eg na ta in f ig . 6) . le ge nd a: 1 ) co p er tu re d et rit ic he q ua te rn ar ie ; 2) c al ca ri a c al p io ne lle ; 3) d ia sp ri; 4 ) b as al ti e b re cc e as so ci at e; 5 ) l in ea m en ti te tt on ic i. g eo lo gi ca l c ro ss -s ec tio n of t he p ia no d i o ne to (t he t ra ce is in d ic at ed in f ig . 6 ). le ge nd : 1 ) q ua te rn ar y d et rit al c ov er ; 2 ) c al p io ne lle l im es to ne s; 3 ) j as p er s; 4 ) b as al ts a nd a ss oc ia te d b re cc ia s; 5) t ec to ni c al ig nm en ts . fi g. 9 s ez io ne g eo lo gi ca l on gi tu d in al e d el p ia no d i o ne to ( la t ra cc ia è s eg na ta i n fi g. 6 ). le ge nd a: 1 ) co p er tu re d et rit ic he q ua te rn ar ie ; 2) a rg ill e a p al om b in i; 3) c al ca ri a c al p io ne lle ; 4) b as al ti e b re cc e as so ci at e; 5 ) f or m az io ne d i c ol lita va ro ne ; 6 ) t ra cc ia d el p ia no a ss ia le d el la m eg ap ie ga c or ic at a d el la v al g ra ve gl ia ; 7 ) s ov ra sc or rim en ti; 8 ) l in ea m en ti te tt on ic i; 9) li ne e d i r ot tu ra d el v er sa nt e d ov ut e al la d ef or m az io ne g ra vi ta tiv a p ro fo nd a d i v er sa nt e. lo ng itu d in al g eo lo gi ca l s ec tio n of t he p ia no d i o ne to (t he t ra ce is in d ic at ed in f ig . 6 ). le ge nd : 1 ) q ua te rn ar y d et rit al c ov er ; 2 ) p al om b in i c la ys ; 3 ) c al p io ne lle l im es to ne s; 4 ) b as al ts a nd a ss oci at ed b re cc ia s; 5 ) c ol lita va ro ne f or m at io n; 6 ) t ra ce o f t he h or iz on ta l a xi al p la ne o f t he m eg af ol d o f v al g ra ve gl ia ; 7 ) t hr us ts ; 8 ) t ec to ni c al ig nm en ts ; 9 ) s lo p e fr ac tu re li ne s d ue t o d gs d . una deformazione gravitativa profonda ... lavori citati abbate e., bortolotti v., galbiati b. & principi g. (198092) carta geologica delle ofioliti del bargonasco e dell’alta val graveglia. l.a.c. firenze. brandolini p., faccini f., robbiano a. & terranova r. (2005) valorizzazione turistica e salvaguardia ambientale dei siti d’interesse carsico nella val graveglia (appennino ligure). in (a cura di): terranova r., brandolini p., firpo m. la valorizzazione turistica dello spazio fisico come via alla salvaguardia ambientale. pàtron editore, bologna 2005. cancelli a., pellegrini m. & tosatti g. (1987) alcuni esempi di deformazioni gravitative profonde di versante nell’appennino settentrionale. mem. soc. geol. it., 39, 447-466. cozzani e. (1972) la cavità carsica di pratoneto, in località piani di chiapozzo (appennino ligure orient.). mem. accad. lunig. di sc. “g. capellini”, 38, 29 – 36, la spezia, 1968. decandia f.a. & elter p. (1972) la zona ofiolitifera del bracco nel settore compreso fra levanto e la val graveglia (appennino ligure). mem. soc. geol. it., suppl. al vol. 11, pp. 503-530. decandia f.a. & elter p. (1969) riflessioni sul problema delle ofioliti nell’appennino settentrionale (nota preliminare). atti soc. tosc. sc. nat., mem.., ser. a, 76, 1 – 9. dramis f., maifredi p. & sorriso-valvo m. (1985) deformazioni gravitative profonde di versante. aspetti geomorfologici e loro distribuzione in italia. geol. appl. idrogeol., 20, 377-390. dramis f. & sorriso-valvo m. (1994) deep-seated gravitational slope deformations, related landslides and tectonics. engineering geology, 38, 231-243. fanucci f. & nosengo s. (1979) rapporti fra la neotettonica del versante marittimo dell’appennino ligure e del margine continentale e fenomeni morfogenetici. boll. soc. geol. it., 96 (1977), 41-51. federici p.r., capitani m., chelli a., del seppia n. & serani a. (2004) atlante dei centri abitati instabili della liguria, ii. provincia di genova. c.n.r. g.n.d.c.i., regione liguria, università degli studi di pisa. galbiati b. (1970) carta geologica schematica della “ruga del bracco” tra monte zatta e moneglia. atti ist. geol. univ. pavia, 21, 148 – 152. galbiati b. (1977) le deformazioni della successione ofiolitica nell’alta val graveglia. ofioliti 3(1), 9 – 34. galbiati b. & principi g. (1990) da varese ligure a levanto. le unità liguri interne. in soc. geol. it. (1990): guide geologiche regionali, appennino ligure-emiliano, be-ma ed. maifredi p. & pastorino m.v. (1974) contributo allo studio morfologico delle depressioni carsiche in liguria. il prato d’oneto”, nell’alta val graveglia (ge). atti xi congr. naz. di speleologia, genova 1 – 4 nov. 1972. maifredi p. & giammarino s. (1968) osservazioni idrogeologiche sulle risorgenti del rivo orti (alta val graveglia – provincia di genova). atti ist. geol. univ. ge, 6 (1), 171 187. marini m. (1994) alcuni esempi di sdoppiamento di crinale nell’appennino ligure. in: studi geografici in onore di domenico ruocco. a cura di f. citarella. loffredo editore, napoli 1994. marini m. (2002) carta geologica del pliocene ligure nell’areale di ventimiglia-bordighera. s.e.l.c.a., firenze 2002. marroni m. (1990) le unità liguri interne tra l’alta val di vara ed il mar ligure (appennino settentrionale): evoluzione di un settore del dominio oceanico ligure-piemontese. tesi di dottorato, dipartimento di scienze della terra dell’università di pisa, 338 pp. marroni m. & meccheri m. (1993a) carta geologico strutturale dell’alta val di vara (appennino ligure). l.a.c. firenze. marroni m. & meccheri m. (1993b) l’unità di colli/tavarone in alta val di vara (appennino ligure): caratteristiche litostratigrafiche e assetto strutturale. boll. soc. geol. it., 112, 781 798. meccheri m., marroni m., casella a., della croce g. & sergiampietri l. (1986) l’unità di colli/tavarone nel quadro dell’evoluzione stratigrafica e strutturale del dominio ligure (alta val di vara, appennino settentrionale). ofioliti, 11, 275 – 292. nosengo s. (1970) osservazioni geologiche e strutturali nella zona compresa fra la val reppia ed il torrente petronio (liguria orientale). atti ist. geol. univ. genova; 7 (2), 231 – 278. nosengo s. (1979) approccio metodologico per l’elaborazione del piano di bacino del t.bisagno: le indagini geologiche. atti seminario su la pianificazione di bacino. c.n.r., p.f. conservazione del suolo; ist. idraulica univ. di genovaregione liguria, genova, 1979. provincia di genova (2003) carta della franosità reale (scala 1:10.000). piano di bacino, ambito 16. regione liguria (2002) note illustrative e carta geologica con elementi di geomorfologia – bargagli – tavoletta n° 214.3 (scala 1:25.000). regione liguria (2006) carta geologica regionale (carg) sc. 1:25000 lavagna tav. 232.4. http://ecozero.liguriainrete.it rovereto g. (1904) geomorfologia delle valli liguri. atti r. univ. genova, 18, 215 pp. rovereto g. (1939) liguria geologica. mem. soc. geol. it., 2, 104 – 118 sorriso-valvo m. (1979) trench features on steepseded ridges, aspromonte, calabria, italy . proceeds. polish-italian seminar on superficial mass movements in mountain regions, szymbark, 1979, may: 98-109, institut meteorologii i gospodarki wodnej, warszawa. sorriso-valvo m. (1984) atti del i seminario ”deformazioni gravitative profonde di versante” — presentazione.boll. soc. geol. it., 103, 667-669. sorriso-valvo m. (1988) studi sulle deformazionii gravitative profonde di versante in italia. mem. soc. geol. it., 41, 877-888. sorriso-valvo m. (1995) considerazioni sul limite tra deformazione gravitativa profonda di versante e frana.mem. soc. geol. it., 50, 179-185. 56 ms. ricevuto il 20 gennaio 2007 testo definitivo ricevuto il 20 febbraio 2007 ms. received: january 20, 2007 final text received: february 20, 2007 l. carobene & a. cevasco amq32(1) marra 31-41.pub studies on the pleistocene of latium: understanding the glacio-eustatic forcing on the aggradational successions of the tyrrhenian sea margin of central italy fabrizio marra istituto nazionale di geofisica e vulcanologia, rome, italy. corresponding author: f. marra <fabrizio.marra@ingv.it> abstract: the studies conducted by francesco paolo "antonello" bonadonna in the area of rome during the 1960s laid the basis for development of the first complete chronostratigraphy scheme for the middle-upper pleistocene of this region. this scheme reported the succession of alternating erosional phases and transgressive series, and their correlation with the limited number of glacial-interglacial cycles known at that time, highlighting the implicit glacio-eustatic trigger of the sedimentary process. besides describing the observations and the inferences that allowed bonadonna to develop the methodological approach to the study of the stratigraphy of this region, in the present paper i will also show how, starting from these basic principles, the modern chronostratigraphic framework of glacio-eustatically controlled aggradational successions used today to describe the stratigraphy of the tiber basin has been developed. keywords: chronostratigraphy, rome, aggradational successions, glacio-eustasy, erosive phases, transgressive series. available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 32 (1), 2019, 31 41 1. introduction in the years 1963-1970, francesco paolo (antonello for all who have worked with him) bonadonna published a series of works under the collection title "studi sul pleistocene del lazio", which laid the basis of the modern approach to the study of the glacio-eustatic forcing on the sedimentation processes in the area of rome. results of these studies were eventually summarized in 1972 in the paper "a scheme of pleistocene chronology for the tyrrhenian side of central italy", by ambrosetti, azzaroli, bonadonna and follieri, providing the first detailed chronostratigraphic scheme for this region. this scheme was based on the identification of a series transgressive series separated by erosional phases, which were correlated with the limited number of glacial periods known at that time, highlighting the implicit glacio-eustatic trigger of the sedimentary process. the erosional phases in this scheme are those previously identified by blanc and other authors, who named them after the main consular roads in the northern area of rome, where their observations were conducted and type sections were described: cassia, flaminia, nomentana. a synthesis of this broader scheme is provided in table 1 of the present paper, where it is compared with an up-to-date chronostratigraphy for the area of rome (luberti et al., 2017). indeed, this scheme provided the basis of the chronostratigraphic and paleoclimatic studies that many scholars, among them the author of the present contribution, have conducted in the area of rome since the early 1990s. in this paper, i will describe the observations and the inferences that allowed bonadonna to develop the methodological approach to the study of the stratigraphy of this region. i will show also how, starting from these basic principles, the modern chronostratigraphic framework of glacio-eustatically controlled aggradational successions used today to describe the stratigraphy of the tiber basin has been developed. 2. diatomitic basins and volcanic layers: chronostratigraphically constrained paleoclimatic archives in his early works, bonadonna (1963, 1964, 1965) investigated three diatomitic basins located to the north of rome, within the volcanic region of the monti sabatini district, highlighting the chronostratigraphic constraints https://doi.org/10.26382/amq.2019.03 32 marra f. tab. 1 the chronostratigraphic scheme by ambrosetti et al. (1972) based on alternating erosive phase and transgressive series (on the right, in brackets: ages in ka) is compared to the modern chronostratigraphic scheme based on 40ar/39ar ages of volcanic products and correlation of aggradational successions with sea-level rise during glacial terminations (to the left). the earliest chronostratigraphic scheme providing tentative correlation with the oxygeen isotope curve proposed by conato et al. (1980) is also shown. first column in the scheme by luberti et al. (2017) provides correlation with marine isotopic stage (mis; first row) and glacial termination (t-, second row). numbering of isotopic stages after bassinot et al. (1994). second column provides ages for the isotopic intervals reported in first column (first row) after bassinot et al. (1994), and ages for glacial terminations (second row), after astrochronocalibration by lisiecki and raymo (2005), with the exception of the last glacial termination (t-i) for which is reported the age of melt-water pulse 1a after stanford et al. (2006). 40ar/39ar ages (ka) of the eruptive cycles and eruptive units after gaeta et al. (2016) and marra et al. (2016c) and references therein, are also provided in this column. the third column provides names of the formations and of the successions (see also fig. 1) corresponding to the aggradational successions. the fourth and fifth columns provide names of the volcanic units and their 40ar/39ar ages in ka. 33 studies on the pleistocene of latium: understanding the tyrrhenian sea margin of central italy provided by the occurrence of the pyroclastic deposits intercalated in these lacustrine successions. he was among the first scholars to understand the opportunity provided by the prolonged and intense explosive volcanic activity of this region to date the geologic events that occurred during the middle pleistocene (i.e., a tephrochronologist ante litteram). on the basis of identification of known eruptive units interbedded with the sedimentary deposits, he recognized the chronological order of the three lacustrine successions even in the absence of direct stratigraphic evidence. moreover, he framed the deposition of the sediments within the embryonic scheme of alternating erosive and depositional phases outlined at that time, and he discussed their paleoclimatic implications, forming a prelude to what would eventually become the modern methodological approach to the study of the interplay between glacioeustasy and sedimentation in the area of rome. finally, he was a pioneer of the radiometric dating of the volcanic products, aimed at providing absolute ages for the sedimentary and volcanic successions and highlighting the relationships with the glacial/interglacial periods, by developing with giulio bigazzi the "fission-track" dating method (bonadonna & bigazzi, 1968, 1970). hereby, i would like to summarize the conclusions of the 1965 paper on the chronostratigraphy of the valle dell'inferno diatomitic basin of riano and its relationships with the volcanic deposits cropping out along the via flaminia in cava nera molinario. bonadonna observed the strong differences in elevation affecting the contact between the earliest volcanic deposits, including the "vacuolar yellow lithoid tuff" (=tufo gialo della via tiberina and tufo giallo di prima porta) and the "lower granular tuff" (=tufo del palatino) (karner et al., 2001a), and the marine-brackish substrate of calabrian and sicilian age, coming to the conclusion that "the lithoid tuff filled pre-existing valleys and leveled the zone". therefore, he associated the occurrence of this erosive phase and the concurrent emplacement of the tuff with the flaminian cold period, following nomenclature and previous observations made in this area by blanc et al. (1955). he also noted that "the whole area was finally remodelled by an exceptionally erosive phase, which removed, sometimes completely, the continental or volcanic sediments which had deposited, up to then, on the calabrian or sicilian sand. the "black pumice tuff" (=tufo rosso a scorie nere sabatino, mattias and ventriglia, 1970; table 1) poured as a mudflow on this deeply marked zone." consistent with blanc et al.'s (1955) observation that the eruption of the "black pumice tuff" was ascribed to a time just preceding the nomentano cold period, bonadonna noted that it was affected by strong erosion, "since very few outcrops are left in place", and deduced that the lake of valle dell'inferno (whose diatomitic deposits unconformably overlie the tufo rosso a scorie nere) "began to exist certainly after the erosion (...) that we can ascribe to the nomentano". in figure 1 i have depicted the stratigraphic schemes of the two sites investigated by bonadonna (1965), updated with the modern geochronologic constraints provided by 40ar/39ar dating of the volcanic products (marra et al., 2018), which allow correlation of the erosional and aggradational phases with the sea-level fig. 1 a series of geochronologically constrained aggradational phases (yellow vertical boxes), corresponding to as many formally introduced sedimentary successions (formation) in the area of rome, has been directly correlated with post-glacial sea-level rises (glacial terminations ti tx) and the corresponding marine isotopic stages (miss). vertical red lines are the age constraints derived by the 40ar/39ar dating of the volcanic deposits intercalated within the aggradational units of the paleotiber river; each colored box individuates a period of sea-level rise that accounts for the deposition of the sedimentary successions in the coastal area of rome. minor aggradational phases linked with smaller sea-level oscillations (sub-stages of the δ18o record) are given the rank of 'succession'. oxygen isotopes curve after lisiecki and raymo (2005); stage numbering after bassinot et al. (1994). oscillations linked with the glacial/interglacial phases, as detected on the marine oxygen isotope records. these schemes show how much of this correlative method is inherited from the original approach employed by bonadonna to assess the interplay between climate oscillations and erosional/depositional phases. indeed, he lacked only a reliable dating method to assess the absolute age of the recognized events. today, we know that two distinct eruptions emplaced the tufo giallo della via tiberina and the tufo giallo di prima porta (previously identified as a single volcanic unit corresponding to the "vacuolar lithoid tuff", later named colata piroclastica inferiore di sacrofano by de rita et al., 1993) at 546 ±3 and 516 ±1 ka, respectively (karner et al., 2001a; marra et al., 2014a; 2017a). moreover, we know that the previously named "peperino della via flaminia" (the "lower granular tuff" by bonadonna, 1965) is actually a distal deposit of the tufo del palatino erupted by the colli albani volcanic district 533 ±2 ka (karner et al., 2001a). finally, we have very precise ages for the tufo rosso a scorie nere sabatino (hereby trsn: 452 ±2 ka, karner et al., 2001a) and for a series of volcanic units constraining the time of deposition of the two aggradational successions emplaced during sea-level rise of mis 13 and mis 11: the valle giulia and the san paolo formations (karner & marra, 1998) (figure 1). in the following section i will describe the basic principles of the methodological approach based on the aggradational succession sedimentary model, and afterwards i will show how it applies to the stratigraphic setting of riano and cava nera molinario discussed by bonadonna (1965). 3 . a g g r a d a t i o n a l s u c c e s s i o n s : a methodological approach deeply rooted in previous studies following the criterion by which sea-level oscillations linked with glacial cycles controlled the alternating erosional and depositional phases within the tiber river basin and its delta, karner & marra (1998) have introduced the concept of the "aggradational section". this is defined as the stratigraphic record of a complete glacially forced sea-level oscillation in a coastal area, as represented by a basal erosive surface, progressively excavated as a consequence of coastline regression and lowering of sea level during glacial periods, covered by a fining-upward sequence of clastic sediments (namely the aggradational succession), rapidly deposited during sea-level rise in response to deglaciation. generally, the aggradational successions recognized in rome display a gravel and sand layer at the base of each complete section. this basal coarse-grained deposit is followed by a relatively thin sand horizon, which grades rapidly upward into a several meters thick package of silt and clay deposits that represents the largest portion of the aggradational succession. a large number of 40ar/39ar ages for volcanic layers intercalated within the sedimentary deposits in the coastal area of rome allowed the verification and refinement of the correlation with the oxygen isotope timescale (karner & renne, 1998; marra et al., 1998; karner et al., 2001b; florindo et al., 2007) (figure 1). later on, marra et al. (2008; 2016a) developed a sedimentary model in which the abrupt transition from gravel to clay within the aggradational successions of the tiber river represents a good proxy for the glacial termination. the conceptual sedimentary model has been tested and formulated on the last deglaciation cycle, i.e., the glacial termination i and holocene, for which a robust radiocarbon chronological framework is available. specifically, 14c age constraints on the sedimentary record deposited within the valley and in the coastal plain of the modern tiber river (marra et al., 2008; 2013; 2016a) have shown that the deposition of gravel marked a unique time in the depositional history of the river, occurring during a ~7 ka interval between the end of the last glacial maximum (lgm 21-18 ka) and the onset of the last glacial termination (lgt ~14 ka). indeed, transportation by the tiber river of gravel with grain size >5 cm required exceptional hydrologic conditions that have not been repeated during the holocene. while continuous transportation of coarse material occurs during the regressive phase, this material cannot accumulate within the fluvial incision or within the coastal plain, as a consequence of the continued regression of the coastline, causing its removal and redeposition seaward, while the base level of the sedimentary record is progressively deepened. conditions for rapid accumulation of coarse gravel typically exist only 34 >>>>> fig. 2 a) geologic map of the aniene tiber valley north of rome (from marra et al., 2015); tgs: tufo giallo di sacrofano, tl: tufo lionato, pr: pozzolane rosse, tt: pyroclastic products of the early tuscolano artemisio phase and monti sabatini volcanic district; i-ii-iii trace of composite cross-section shown in inset b; b) reconstruction of geometry and elevation of the sedimentary bodies of aggradational successions deposited during sea-level rises of mis 9, mis 8.5 and mis 7, based on geologic remnants of the original deposits including the basal gravel layer, and comparison with that of the last aggradational succession of mis 1, based on borehole data. an elevation gain of ca. 40 m is observed between the reconstructed alluvial plains of the deposits correlated with mis 9 and mis 7 with respect to that of mis 1, consistent with the occurrence of the regional uplift since 200 ka (see inset d); consequently, an intermediate elevation around present day sea -level iusexpected for the basal gravel layer of the mis 5.5 aggradational succession. b') stratigraphy of saccopastore reporting the position of the two neanderthal skulls (s1 and s2) and interpreted stratigraphy, showing the occurrence of three mis 7 aggradational phases (a, b, c) erosionally above the basal gravel layer of the aurelia formation (mis 9); c) curve of global relative sea level (rsl, grant et al., 2014) in the time span 290-200 ka, showing the occurrence of three consecutive peaks (a, b, c, highlighted by the thick yellow lines) at around 270 ka, 245 ka, and 220 ka. the oxygen isotope curve (lisiecki and raymo, 2005) for the same time span is also reported, showing that the three aggradational successions recognized in saccopastore (a, b, c) are correlated with the three sea-level rises occurring during mis 7, providing indirect ages of 245 ka and 220 ka for the two skulls, s1 and s2, respectively; d) uplift curve for the coastal sector of rome; the dashed line represents an alternative hypothesis based on similar sea-levels than in the present for mis 5.3 and 5.1 (see marra et al., 2016b, for a discussion). marra f. 35 studies on the pleistocene of latium: understanding the tyrrhenian sea margin of central italy during deglaciation phases due to the combination of several factors such as the increased sediment supply to the tiber drainage basin, caused by fast melting of apennine glaciers releasing a large amount of clastic material, combined with the low sea level causing a steeper gradient, and hence greater river transport capacity. these conditions would have worked in concert during the 18-14 ka interval, until the accelerated sealevel rise during the lgt led to a rapid drop in capacity of transport by the tiber and, consequently, to the start of sandy clay deposition and filling of the fluvial incisions. 4. practical application of the aggradational succession method due to the processes that guide their formation, aggradational successions are intrinsically discontinuous records of ten major units deposited during the major glacial cycles spanning mis 21 thorough mis 1 by the (paleo) tiber river and its tributaries in the nearcoastal to coastal area, plus several minor successions associated with the more pronounced sea-level oscillations within the same isotopic stage (sub-stages). the corresponding sedimentary deposits have been designated by formal formation names, as shown in the chronostratigraphic scheme of table 1 (luberti et al., 2017). these sedimentary successions are variably exposed along the banks of the hills shaped from an original pyroclastic plateau, eroded by fluvial incisions of the tiber river and its tributaries in consequence of the interplay between glacio-eustasy and a discontinuous regional uplift that affected the tyrrhenian sea margin of central italy in the last 800 ka (karner et al., 2001b; marra et al., 2016b). therefore, the stratigraphic record of each glacio-eustatic cycle occurs at a different elevation, depending on the absolute sea-level during each glacial/interglacial period and on the amount of uplift experienced since their deposition, thus offering a further geometric criterion for its identification. this is the case at the archaeological site of saccopastore, where two neanderthal skulls were recovered in the years 1929-35 within two gravel layers at the base of a finingupward succession cropping out in the aniene river valley north of rome (sergi, 1929; breuil & blanc, 1935). an age of ca. 130 ka was initially estimated for the human individuals, based on attribution of the deposit to a fluvial terrace of the last interglacial stage (mis 5e) (blanc, 1939, 1946, 1948; segre, 1948), whereas an age as young as 80 ka was subsequently proposed (manzi et al., 2001), due to the occurrence of cold climate vegetal species (leaves) within the sedimentary record. however, by simply applying the basic principles of the aggradational succession sedimentary model, marra et al. (2017b) recognized that the gravel layers marked a glacial termination rather than an interglacial period, consistent with the cold paleoclimatic indicators of the associated clay section. moreover, their elevation excluded an age within mis 5, while it matched that pertaining to the mis 7 aggradational succession of the vitinia formation (250-210 ka, karner & marra, 1998; marra et al., 2016a), consistent with stratigraphic relationships between the saccopastore sedimentary deposit and the well-constrained mis 9 and mis 8.5 deposits of the aurelia formation and of the via mascagni succession (350 through 285 ka, marra et al., 2017b) cropping out in this area (figure 2). the composite cross-section of figure 2 shows that the two gravel layers where the neanderthal skulls (s1 and s2 in figure 2b) were recovered occur above a third, thicker gravel layer which was already identified as part of an older succession, due to the presence of middle pleistocene faunal remains (i.e., an archaic form of elephas (=palaeoloxodon) antiquus; breuil & blanc, 1936). the stratigraphic relationship of this gravel with the pyroclastic-flow deposit of tufo lionato (365 ±4 ka, marra et al., 2009) allows its identification as the basal gravel layer of the mis 9 aggradational succession (figure 2b), the sedimentary deposits of which (aurelia formation) crop out extensively in this area (figure 2a). therefore, the upper gravel layers constitute the basal coarse portion of the successive aggradational succession of mis 7 (figure 2b), which is embedded within the eroded deposits of the previous one, and occurs at the same elevation, consistent with the lack of regional uplift in the time span 400-200 ka (see uplift curve by marra et al., 2016b in figure 2d). in contrast, the following aggradational successions must display a base level at progressively lower elevation, due to the ca. 60 m intervening uplift in the time span 200 ka present (figure 2d). consistently, the basal gravel layer of the mis 1 aggradational succession is found at ca. 15 m below the present sea level in the boreholes drilled within the alluvial filling of the aniene valley (marra et al., 2015), ca. 35 m lower than the equivalent gravel layer of mis 7 (figure 2b). similarly, the equivalent gravel layer of mis 5 should occur at intermediate elevation, around the present sea-level (figure 2b), ruling out the hypothesis that the gravel occurring between 15 and 19 m a.s.l. in saccopastore may have been emplaced during the penultimate glacial termination of mis 5.5. correlation with mis 7 for the upper gravel beds of saccopastore is further supported by re-determination of a upper molar of 36 >>>>> fig. 3 a) stratigraphic schemes of the localities along via flaminia described by bonadonna (1965), updated with the geochronologic constraints providing correlation (b) with the aggradational successions of mis 13 and mis 11 (valle giulia and span paolo formations: vgf and spf) (from marra et al., 2018). c d) composite cross-sections showing the aggradational sections of the valle giulia and san paolo formation cropping out in distinct locality of the tiber valley, with the intercalated volcanic layers whose 40ar/39ar ages (numbered in circles) allow to reconstruct the time of aggradation and to compare it with the d18o curve in inset b; d') age constraints to the reconstructed sedimentary history of the valle giulia formation show excellent match with the two consecutive sea-level rises during mis 13 (see text for comments and explanations). pg2: ponte galeria 2 formation, scg: santa cecilia formation; tgvt: tufo giallo della via tiberina, tp: tufo del palatino, tgpp: tufo giallo di prima porta, grps: grottarossa pyroclastic sequence; ttpb: tufi terrosi con pomici bianche, trsn: tufo rosso a scorie nere, tgs: tufo giallo di sacrofano. marra f. 37 studies on the pleistocene of latium: understanding the tyrrhenian sea margin of central italy dama dama tiberina, part of the faunal assemblage recovered at this location hosted at the museo pigorini in rome (marra et al., 2017b, salari et al., 2018), a fallow deer sub-species whose occurrence in peninsular italy is limited to mis 8.5-mis 7, and was replaced by dama dama dama during mis 5.5 (di stefano and petronio, 1997; marra et al., 2018). combining all these observations, marra et al. (2017b) suggested that the two gravel layers hosting the two skulls (s1 and s2) correspond to the two sea-level rises of mis 7.5 and mis 7.3, resulting into a pair of consecutive aggradational successions (b and c in figure 2c), preceded by deposition of a fine-sized layer (a) triggered by a moderate, early sea-level rise, as seen in the relative sea level (rsl) curve of grant et al. (2014). 5. the valle giulia and san paolo formations cropping out in via flaminia and riano another practical application of the conceptual model refres to the case of the valle giulia and san paolo formations. in agreement with bonadonna's (1965) observations, the stratigraphic scheme of riano in figure 3a shows that the tufo giallo della via tiberina ("vacuolar lithoid tuff") rests above the eroded marine substrate (monte mario formation, mmf, bonadonna, 1968). consistent with inferences about its emplacement during a cold period (flaminio auct.), the 40ar/39ar age of 546 ±3 ka for this pyroclastic-flow deposit supports the close correspondence with glacial mis 14.2 lowstand (figure 3b). the other volcanic deposit ("lower granular tuff") that bonadonna associated with this cold period is the tufo del palatino (tp) which has an age of 533 ±2 ka, exactly matching the glacial termination via at the onset of mis 13 (figure 3b; marra et al., 2017a). in perfect agreement with the sedimentary model for the aggradational successions, the tp is emplaced above the basal gravel layer of the valle giulia formation (figure 3a), and is covered by the early fining-upward succession deposited during sea-level rise of mis 13.3 (figure 3b). however, this sub-stage is shortly followed by a new sea-level fall culminating in the lowstand of mis 13.2, causing a regressive phase during which the pyroclastic flow deposit of tufo giallo di prima porta (tgpp) is emplaced at 516 ±1 ka (figure 3b). the reconstruction of the sequence of sedimentary processes occurring during this time span is illustrated in figure 3d, showing the initial accumulation of gravel within the paleo-incision of the tiber river since the glacial termination at 535 ka (i), covered by the tp at 533 ka (ii), and followed by aggradation of fine sediments until 524 ka (iii), corresponding to the interstadial of mis 13.3 (see also figure 3d'). the occurrence of a temporary regressive phase 524 through 516 ka (iv) causes the partial incision of the early aggradational succession of the valle giulia formation, and is highlighted by the unconformable contact of the tgpp above the tp, as seen in via flaminia where a 50 cm thick layer of gravel is intercalated between the two volcanic deposits, or directly above the older substrate, as seen in cava rinaldi (figure 3d'). this regressive phase culminates in the lowstand of mis 38 13.2 ca. 513 ka, shortly after the emplacement of tgpp, and is followed by a new sea-level rise caused by glacial termination vib at the onset of mis 13.1, during which the grottarossa pyroclastic sequence emplaced at 510±4 ka (v). the upper part of the valle giulia formation is emplaced during this second aggradational phase (vi), as evidenced by ages of 498 ±2 ka and 496 ±9 ka yielded by the fall a deposits (figure 3b) intercalated with the sedimentary succession in cava rinaldi (figure 3d'). the combined chronostratigraphic and geomorphologic features of the sedimentary record of the valle giulia formation exposed along the tiber river valley, summarized in the composite section of figure 3d', represent an extraordinarily detailed proxy for the sea-level oscillations during the time span encompassing the glacial of mis 14.2 through the interglacial of mis 13.1. this sedimentary record, cropping out in northern rome along the via flaminia, was already recognized as the pariolian transgressive series in the chronostratigraphic scheme by ambrosetti et al. (1972), which followed the flaminian and preceded the nomentanan erosional phases (table 1). also in agreement with bonadonna’s observation, the trsn emplaced 452 ±2 ka during the climax of the marked glacial lowstand of mis 12.2 (figure 3b), and rests above deeply incised valleys within the deposits of the valle giulia formation, as at km 8.2 of via flaminia (figure 3a). moreover, as bonadonna correctly noted, the pyroclastic flow deposit is eroded after its deposition, consistent with the continued sealevel fall which occurred from 450 to 435 ka (figure 3b), and the deposition of the lacustrine succession in riano postdates the nomentano cold period. indeed, in riano, like in all the tiber river basin, sediment aggradation occurs in response to the sea-level rise of mis 11.1, during glacial termination v, and is represented by the deposits of the san paolo formation (figure 3b). in particular, the glacial termination is bracketed by ages of 436 ±6 ka yielded by a pyroclastic layer intercalated in the basal gravel layer in pantano di grano, and of 422 ±5 ka yielded by a fallout layer occurring immediately above it in malagrotta (figure 3c). the upper, finegrained portion of the san paolo formation was deposited during the mis 11 highstand, as evidenced by ages of 412 ±2 and 406 ±5 ka yielded by the tephra layers occurring at higher elevation within the sedimentary succession in santa cecilia and riano, respectively (figure 3a, b, c). the san paolo formation was introduced only in 1995 by marra & rosa, and the proposed correlation with mis 11 has been demonstrated by 40ar/39ar dating of the volcanic layers intercalated within the sedimentary succession cropping out at pantano di grano, malagrotta and santa cecilia in the area of ponte galeria (karner & marra, 1998; figure 2c). in contrast, only one transgressive phase dated at 280 ka, named rianian after the abovementioned locality, was previously recognized, which was successively named aurelia formation and correlated with mis 9 (conato et al., 1980) (table 1). however, recent dating at 406 ±5 ka of the fallout deposit occurring in the upper portion of the lacustrine succession in riano provided evidence for reappraising its previous chronological and stratigraphic marra f. attribution to the mis 9 and pre-dating it to the mis 11, as well as for the three cervid skeletons found at this locality and consequently classified with the species name cervus rianensis, which for decades have been considered typical of the mis 9 faunal unit of torre in pietra (marra et al., 2018). previous lack of identification of the occurrence of two full glacial cycles plus a minor sea-level oscillation in the time span 430-270 ka (see table 1) was at the base of the widespread attribution to the aurelia formation and, successively, to mis 9 of most of the geologic sections cropping out along the via aurelia (hence the formation name) hosting the faunal assemblages of the torre in pietra faunal unit of the aurelian mammal age (gliozzi et al., 1997). incidentally, the only section for which 40ar/39ar geochronologic constrains demonstrated a time of deposition compatible with mis 9 is that exposed in torre in pietra (villa et al., 2016), whereas all the other sedimentary successions previously attributed to the aurelia formation along the homonymous consular road have been re-assessed and placed within mis 13 and mis 11 (valle giulia and san paolo formations) (marra et al., 2018), resulting in a deep revision of the biochronological context of the aurelian mammal age (petronio et al., 2018). unfortunately, application of the not properly accurate uranium fission-track dating method resulted in a partial dismissal of the correlation between climate oscillations and the observed erosional/depositional phases. it was precisely the incorrect age of 0.225 ma yielded by a volcanic layer occurring at the top of the tuffaceousdiatomitic succession in riano (ambrosetti et al., 1969) (very likely the same fallout layer dated in marra et al., 2018 at 406 ±5 ka), that induced these authors to conclude that "the local names provided by blanc (1958) to the cold periods of the campagna romana should be considered completely unrelated with climatic oscillations, but linked with erosional phases mostly related with local tectonics". an unfortunate conclusion for an extraordinary series of field observations and insightful inferences! 6. a new chronostratigraphic scheme widespread application of the worldwide attested 40ar/39ar dating method has substantially changed the chronology of the transgressive series recognized in this region, demonstrating a close match with even the minor glacio-eustatic sea-level oscillations in the marine isotope timescale for the equivalent aggradational successions. besides giving back the deserved credit to blanc’s intuition, the new chronostratigraphic picture highlights the correctness of bonadonna's accurate and insightful field observation, as shown in table 1, and its invaluable contribution to successive studies. a fundamental link in this step forward was the work "new data on the pleistocene of rome" by conato et al. (1980), in which the basic framework of the local sedimentary successions which eventually became the aggradational successions was provided, along with the first tentative correlation with the stages of the oxygen isotope curve. based on the methodological approach described in luberti et al. (2017), the stratigraphic scheme in table 1 is an informal succession of ubsus, defined based on the following criteria: i) sedimentary units are deposited by an aggradational mechanism during glacial terminations in a time span encompassing the end of the glacial maximum through the subsequent interglacial stage; ii) 40ar/39ar age constraints yielded by intercalated volcanic deposits provide correlation with the isotope chronology of lisiecki & raymo (2005) and stage numbering by basinot et al. (1994); iii) sedimentary units emplaced during the main glacial terminations are given the rank of formation, while those emplaced during minor sea-level fluctuations linked with isotope sub-stages are given the rank of succession. iv) stratigraphic nomenclature accounts for the originally introduced formation names by the authors, whenever stratigraphic position does not conflict with the successively achieved geochronologic constraints. the sedimentary features of these aggradational successions encompass fluvial to lacustrine and lagoon to coastal facies, as described in conato et al. (1980) and references therein. a detailed facies analysis of the deposits cropping out in the coastal area of rome is provided in several papers (e.g. milli et al., 2008, and references therein) describing a suite of fourth-order depositional sequences, whereas correlation of the deposits defined based on the sequence stratigraphic approach with the glacio-eustatically controlled aggradational successions of the paleotiber river can be found in marra et al. (2014b). based on the revised definition of the stratigraphic sequence by zecchin & catuneanu (2013), all the recognized aggradational successions represent the innermost part of high-frequency sequences linked to glacio-eustasy. references ambrosetti p., bonadonna f.p., tolomeo l. (1969) studi sul pleistocene del lazio. vi una nuova data per la campagna romana. bollettino della società geologica italiana, 88(01), 3-10. ambrosetti p., azzaroli a., bonadonna f.p., follieri m. (1972) a scheme of pleistocene chronology for the tyrrhenian side of central italy. bollettino della società geologica italiana, 91(1), 169-184. bassinot f.c., labeyrie l.d., vincent e., quidelleur x., shackleton n.j. lancelot, y. (1994) the astronomical theory of climate and the age of the brunhes-matuyama magnetic reversal. earth and planetary science letters, 126(1-3), 91-108. blanc a.c. (1958) torre in pietra, saccopastore e monte circeo. la cronologia dei giacimenti e la paleogeografia quaternaria del lazio. boll. soc. geogr. it., ser. 8, ii(4-5), 196-214. blanc a.c., cova g., franceschi p., lona f., settepassi f. (1955) ricercha sul quaternario laziale. ii. una torba glaciale, avifauna artica e malacofauna montana nel pleistocene medio-inferiore nell'agro cerite e di rom. il periodo glaciale flaminio. quaternaria, 2, 159-186. blanc a.c. (1939) il giacimento musteriano di saccopastore nel quadro del pleistocene laziale. ri 39 studies on the pleistocene of latium: understanding the tyrrhenian sea margin of central italy vista di antropologia, 32 (1938-39), 223-235. blanc a.c. (1946) i reperti musteriani di saccopastore e la posizione cronologica del giacimento alla luce dei recenti ritrovamenti. in: atti v congresso nazionale studi romani (1937), 3-11, roma. blanc a.c. (1948) notizie sui trovamenti e sul giacimento di saccopastore e sulla sua posizione nel plesitocene laziale. palaentographia italica, 42 (1942-46), 3-23. bonadonna f.p. (1963) studi sul pleistocene del lazio i. il bacino diatomitico di prima porta. geologica romana, 2, 179-198. bonadonna f.p. (1964) studi sul pleistocene del lazio ii. il bacino diatomitico di cornazzano. geologica romana, 3, 383-404. bonadonna f.p. (1965) further information on the research in the middle pleistocene diatomite quarry of valle dell'inferno (riano, rome). quaternaria, 7, 279-299. bonadonna f.p. (1968) studi sul pleistocene del lazio. v la stratigrafia di monte mario e la "fauna malacologica mariana" di cerulli irelli", memorie della societa geologica italiana, 7(02) 261-321 bonadonna f.p., bigazzi g. (1968) studi sul pleistocene del lazio. vii età di un livello tufaceo del bacino diatomitico di riano stabilita col metodo delle tracce di fissione. bollettino della società geologica italiana, 87(02), 261-321. bonadonna f.p., bigazzi g. (1970) studi sul pleistocene del lazio. viii datazione di tufi intertirreniani della zona di cerveteri (roma) mediante il metodo delle tracce di fissione. bollettino della società geologica italiana, 89(04), 463-473. breuil h., blanc a.c. (1935) il nuovo cranio di homo neanderthalensis e la stratigrafia del giacimento di saccopastore (roma). bollettino società geologica italiana, 54, 289-300. conato v., esu d. malatesta, a. zarlenga f. (1980) new data on the pleistocene of rome. quaternaria, 22, 131-176. de rita d., funiciello r., corda l., sposato a., rossi u. (1993) volcanic units. in: di filippo, m. (ed.), sabatini volcanic complex, quad. ric. sci., vol. 114, progetto finalizzato geodinamica c.n.r., roma, 33-79. di stefano g., petronio c. (1997) origin and evolution of the european fallow deer (dama, pleistocene). neues jahrbuch für geologie und paläontologie abhandlungen, 203, 57-75. florindo f., karner d.b., marra f., renne p.r., roberts a.p., weaver r. (2007) radioisotopic age constraints for glacial terminations ix and vii from aggradational sections of the tiber river delta in rome, italy, earth planet. sci. lett., 256, 61-80, 2007. gaeta m., freda c., marra f., arienzo i., gozzi f., jicha b., di rocco t. (2016) paleozoic metasomatism at the origin of mediterranean ultrapotassic magmas: constraints from time-dependent geochemistry of colli albani volcanic products (central italy). lithos, 244, 151-164. doi: 10.1016/j.lithos.2015.11.034 gliozzi e., abbazzi l., argenti p., azzaroli a., caloi l., capasso barbato l., di stefano g., esu d., ficcarelli g., girotti o., kotsakis t., masini f., mazza p., mezzabotta c., palombo m. r., petronio c., rook l., sala b., sardella r., zanalda e., torre d. (1997) biochronology of selected mammals, molluscs and ostracods from the middle pliocene to the late pleistocene in italy. the state of the art. rivista italiana di paleontologia e stratigrafia, 103, 369-388. grant k.m., rohling e.j., bronk ramsey c., cheng h., edwards r.l., florindo f., heslop d., marra f., roberts a.p., tamisiea m.e., williams f. (2014) sea-level variability over five glacial cycles. nature communications, 5, 5076. doi: 10.1038/ncomms6076 karner d.b., marra f. (1998) correlation of fluviodeltaic aggradational sections with glacial climate history: a revision of the pleistocene stratigraphy of rome. geological society of america bulletin, 110, 748-758. karner d.b.,renne p.r. (1998) 40ar/39ar geochronology of roman province tephra in the tiber river valley: age calibration of middle pleistocene sealevel changes. geological society of america bulletin, 110, 740-747. karner d.b., marra f., renne p.r. (2001a) the history of the monti sabatini and alban hills volcanoes: groundwork for assessing volcanic-tectonic hazards for rome. j. volc. and geoth. res., 107, 185215. karner d.b., marra f., florindo f., boschi e. (2001b) pulsed uplift estimated from terrace elevations in the coast of rome: evidence for a new phase of volcanic activity? earth and planetary science letters, 188, 135-148. lisiecki l.e., raymo m.e. (2005) a pliocenepleistocene stack of 57 globally distributed benthic δ18o records. paleoceanography, 20, pa1003. doi: 10.1029/2004pa001071. luberti g.m., marra f., florindo f. (2017) a review of the stratigraphy of rome (italy) according to geochronologically and paleomagnetically constrained aggradational successions, glacio-eustatic forcing and volcano-tectonic processes. quaternary international, 438, 40-67. doi: 10.1016/j.quaint.2017.01.044 manzi g., palombo m.r., caloi l., mallegni f. (2001) transitions in human evolution and faunal changes during the pleistocene in latium (central italy). in: cavaretta g., gioia p., mussi m., palombo m.r. (eds.), the world of elephants, 59-66, roma. marra f, rosa c. (1995) stratigrafia e assetto geologico dell'area romana, in "la geologia di roma. il centro storico", mem. descr. carta geol. d'it., 50, 49-118. marra f., florindo f., karner d.b. (1998) paleomagnetism and geochronology of early middle pleistocene depositional sequences near rome: comparison with the deep sea 18o climate record. earth and planetary science letters, 159, 147-164. marra f., florindo f., boschi e. (2008) the history of glacial terminations from the tiber river (rome): insights to glacial forcing mechanisms, paleocean 40 marra f. ography, 23, pa2205. doi: 10.1029/2007pa001543. marra f., karner d.b., freda c., gaeta m., renne p.r. (2009) large mafic eruptions at the alban hills volcanic district (central italy): chronostratigraphy, petrography and eruptive behavior, journ. of volc. and geoth. res., 179, 217-232. doi:10.1016/j.jvolgeores.2008.11.009 marra f., bozzano f., cinti f.r. (2013) chronostratigraphic and lithologic features of the tiber river sediments (rome, italy): implications on the postglacial sea-level rise and holocene climate. global and planetary change, 107, 157-176. doi: 10.1016/j.gloplacha.2013.05.002 marra f., sottili g., gaeta m., giaccio b., jicha b., masotta m., palladino d.m., deocampo d (2014a) major explosive activity in the sabatini volcanic district (central italy) over the 800-390 ka interval: geochronological geochemical overview and tephrostratigraphic implications. quaternary science reviews, 94, 74-101. doi: 10.1016/j.quascirev.2014.04.010 marra f., pandolfi l., petronio c., di stefano g., gaeta m., salari l. (2014b) reassessing the sedimentary deposits and vertebrate assemblages from ponte galeria area (rome, central italy): an archive for the middle pleistocene faunas of europe. earth-science reviews, 139, 104-122. doi: 10.1016/j.earscirev.2014.08.014 marra f., ceruleo p., jicha b., pandolfi l. petronio, salari l. (2015) a new age within mis 7 for the homo neanderthalensis of saccopastore in the glacio-eustatically forced sedimentary successions of the aniene river valley, rome. quaternary science reviews 129, 260-274. doi: 10.1016/j.quascirev.2015.10.027 marra f., rohling e.j., florindo f., jicha b., nomade s., pereira a., renne. p.r. (2016a) independent 40ar/39ar and 14c age constraints on the last five glacial terminations from the aggradational successions of the tiber river, rome (italy). earth planet sci lett., in press. marra f., florindo f., anzidei m., sepe v. (2016b) paleo-surfaces of glacio-eustatically forced aggradational successions in the coastal area of rome: assessing interplay between tectonics and sea-level during the last ten interglacials. quaternary science review, 148, 85-100. doi.org/10.1016/j.quascirev.2016.07.003 marra f., gaeta m., giaccio b., jicha b.r., palladino d.m., polcari m., sottili g., taddeucci j., florindo f., stramondo s. (2016c) assessing the volcanic hazard for rome: 40ar/39ar and in-sar constraints on the most recent eruptive activity and present-day uplift at colli albani volcanic district. geophysical research letters, 43, 13, 6898-6906. doi: 10.1002/2016gl069518 marra f., jicha b., florindo f. (2017a) 40ar/39ar dating of glacial termination vi: constraints to the duration of marine isotopic stage 13. scientific reports 7, 8908. doi: 10.1038/s41598-017-08614-6 marra f., ceruleo p., pandolfi l., petronio c, rolfo m.f., salari l. (2017b) the aggradational successions of the aniene river valley in rome: age constraints to early neanderthal presence in europe. plos one, 12(1): e0170434. doi: 10.1371/journal.pone.0170434 marra f., nomade s., pereira a., petronio c., salari l., sottili g., bahain j.j., boschian g., di stefano g., falgueres c., florindo f., gaeta m., giaccio b., masotta m. (2018) a review of the geologic sections and the faunal assemblages of aurelian mammal age of latium (italy) in the light of a new chronostratigraphic framework. quaternary science reviews, 181, 173-199. doi: 10.1016/j.quascirev.2017.12.007 mattias p.p., ventriglia u. (1970) la regione vulcanica dei monti sabatini e cimini. mem. soc. geol. it., 95, 831-849. milli s., moscatelli m., palombo m.r., parlagreco l., paciucci m. (2008) incised-valleys, their filling and mammal fossil record: a case study from middle-upper pleistocene deposits of the roman basin (latium, italy). geoacta spec. publ., 1, 67-88. petronio c., di stefano g., kotsakis t., salari l., marra f., jicha b. (2018) biochronological framework for the late galerian and early-middle aurelian mammal ages of peninsular italy, geobios, in press. salari l., ceruleo p., pandolfi l., petronio c., marra f. (2018) a new date for the fauna from saccopastore (lower aniene valley, rome), atti convegno aiaz, lecce,11-14 novembre 2015, 21. segre a.g. (1948) sulla stratigrafia dell’antica cava di saccopastore presso roma. rendiconti accademia lincei (cl. scienze fmn) s. 8, 4, 743-751. sergi s. (1929) la scoperta di un cranio del tipo di neandertal presso roma. rivista di antropologia 28, 457-462. stanford j.d., rohling e.j., hunter s.h., roberts a.p., rasmussen s.o., bard e., mcmanus j., fairbanks r.g. (2006) timing of meltwater pulse 1a and climate responses to meltwater injections. paleoceanography 21, 4: pa4103. doi: 10.1029/2006pa001340 villa p., soriano s., grün r., marra f., nomade s., pereira a., boschian g., pollarolo l., fang f., bahain j-j. (2016) the acheulian and early middle paleolithic in central italy: stability and innovation. plos one, e 11(8): e0160516. doi:10.1371/journal.pone.0160516. zecchin m., catuneanu o. (2013) high-resolution sequence stratigraphy of clastic shelves i: units and bounding surfaces. marine and petroleum geology, 39 (1), 1-25. doi: 10.1016/j.marpetgeo.2012.08.015 41 studies on the pleistocene of latium: understanding the tyrrhenian sea margin of central italy ms. received: november 5, 2018 final text received: january 9, 2019 42 imp.giordano tthhee sseeddiimmeennttaattiioonn aalloonngg tthhee rroommaann ccooaasstt bbeettwweeeenn mmiiddddllee aanndd uuppppeerr pplleeiissttoocceennee:: tthhee iinntteerrppllaayy ooff eeuussttaattiissmm,, tteeccttoonniiccss aanndd vvoollccaanniissmm –– nneeww ddaattaa aanndd rreevviieeww gguuiiddoo ggiioorrddaannoo11,, aalleessssaannddrraa eessppoossiittoo22,, ddoonnaatteellllaa ddee rriittaa11,, mmaarriinnaa ffaabbbbrrii11,, iillaarriiaa mmaazzzziinnii11,, aalleessssaannddrraa ttrriiggaarrii11,, ccaarrlloo rroossaa11 && rreennaattoo ffuunniicciieelllloo11 1dipartimento scienze geologiche università degli studi “roma tre” 2istituto nazionale di geofisica e vulcanologia, roma abstract the quaternary stratigraphy of the roman coastal area is one of the most studied for the excellent exposures of the sedimentary succession, which offer the opportunity to analyse the interplay between eustatism, tectonics and volcanism. we present an updated interpretation based on new stratigraphic and geomorphologic data. sedimentary successions have been organised as unconformity-bounded stratigraphic units, based on the hierarchy of the bounding unconformities. major regional unconformities are related to eustatic sea level changes and regional uplift, whereas tectonic uplift and subsidence produced high relief but localised unconformities. major regional unconformities are related to eustatic sea level changes and regional uplift, whereas tectonic uplift and subsidence produced high relief but localised unconformities. the sedimentary record is best preserved during high stands of the sea level, as constrained by the several available age determinations of volcanic deposits. the transition from marine to continental environments occurred between approximately 850 and 700 ka, when the roman area hosted the deltaic sedimentation from a paleo-tiber river (ponte galeria synthem). the uplift of the nw-trending mt. mario rise, isolated the deltaic sedimentary wedge and forced the paleo-tiber toward the se, inside a subsiding valley wherein a thick succession of fluvial conglomerates was deposited. as a consequence of the river diversion, a large lake or swamp probably developed in the area, bearing an influence upon the early phreatoplinian activity of the colli albani volcano which started at about 600 ka (santa cecilia synthem; ca. 700-550 ka). the growth of the volcano progressively shifted the river back northward, across the monte mario rise (after ca. 550 ka) approximately where the present day river has its course. the valle giulia synthem (ca. 550-450 ka) is made up of clastic and volcaniclastic fluvial deposits, as well as travertine related to both active tectonics (up to 20 m of local uplift) and hydrothermal activity. the subsequent torrino synthem (ca. 450-350 ka) is mostly made up of large volume ignimbrites and lavas erupted both from the colli albani volcano to the s and the sabatini volcanoes to the n. regional and local tectonics was relatively quiescent. this synthem is cut by the erosional unconformity formed during the low stand of the sea level relative to the oxygen isotopic stage 10. the overlying succession has been named quartaccio synthem, characterised at the base by the villa senni eruption unit (ca. 350 ka), a complex ignimbrite succession erupted from the colli albani volcano, which caused the last and largest collapse of its caldera. the following rise of the sea level produced an abrasion surface at the top of the ignimbrite overlain by dune sand (nuova california subsynthem, i.e. duna rossa antica auct.). these deposits are cut by ne-trending faults between pomezia and castelporziano and uplifted by 140+/-5 m during ca. 70 ka, at the rate of 2 mm/y. the uplift produced a local high relief unconformity wherein the aurelia and the vitinia subsynthems were deposited until ca. 280 ka. the top of the quartaccio synthem is presently at elevations comprised between 40 m and 60 m a.s.l. successively, along with the waning of the volcanic activity, regional uplift resumed at a rate of approximately 0.2 mm/y. this allowed the preservation of terraced deposits, along the coastal belt both to the n and s of the tiber delta and along the tiber valley, referred to two different isotopic stages. those related to the oxygen isotopic stage 7 (campo selva synthem), are today preserved between 30 and 40 m a.s.l. whereas those related to the oxygen isotopic stage 5 (saccopastore synthem), occur between 15 and 30 m a.s.l. the computed regional uplift rate is well in agreement with known data for the tyrrhenian terrace along the italian coast. riassunto il litorale romano è uno degli ambienti più studiati per capire le relazioni tra tettonica, vulcanismo ed eustatismo nel corso del pleistocene. questo lavoro propone una nuova sintesi delle complesse relazioni stratigrafiche e geomorfologiche di quest’area. i corpi rocciosi sono stati organizzati in unità stratigrafiche a limiti inconformi, in base alla gerarchia delle superfici che li delimitano. per il pleistocene medio-superiore dell'area romana, le superfici di grado gerarchico maggiore e correlabili a scala regionale, sono legate alle variazioni eustatiche del livello marino, mentre l'azione della tettonica sviluppa superfici ad alto rilievo ma localizzate alle aree di deformazione. le successioni sedimentarie sono da correlare, in genere, agli alti stazionamenti del livello del mare, come suggerito dalle datazioni dei livelli vulcanici intercalati. l’emersione dell’area romana avviene con la deposizione, tra la dorsale di m. mario e la costa, dell’unità di ponte galeria (ca. 850-700 ka) in facies di delta, alimentata da un paleotevere proveniente da n. l’isolamento di questo cuneo deposizionale avviene per l’innalzamento dell’alto di m. mario a direzione nw-se. il tevere è forzato a scorrere ad est di questo cuneo, parallelamente alla costa verso se, lungo una fascia in continua subsidenza con la deposizione di diverse decine di metri di conglomerati, probabilmente determinando una vasta area palustre che condizionerà il carattere freatomagmatico delle prime eruzioni dei colli albani, note come tufi pisolitici. queste unità costituiscono il sintema santa cecilia, depostosi tra 700 e 550 ka ovvero tra lo stadio 17 ed il 15. a partire da questo momento, la crescita del vulcano dei colli albani risospinge il tevere verso nord dove trova un varco verso la costa vicino al suo corso attuale. il successivo sintema valle giulia (stadio 13) accoglie, oltre alla sedimentazione del tevere e quella vulcanoclastica, anche ingenti volumi di travertini a testimonianza di una tettonica attiva con dislocazioni dell’ordine dei 20 m, e di un importante sistema idrotermale legato all’inizio del vulcanismo. nel successivo sintema torrino (stadio 11) sono inclusi i maggiori volumi di prodotti vulcanici, con la messa in posto di vaste coltri ignimbritiche ed espandimenti lavici sia dai colli albani (lave di vallerano, pozzolane rosse, lave di fosso tre rami, pozzolane nere) che dai vulcani sabatini (tufo rosso a scorie nere). durante questo periodo la tettonica regionale è relativamente quiescente. il sintema è tagliato dalla superficie relativa all’abbassamento del livello del mare, durante lo stadio 10, entro cui si depone il sintema aurelia, con alla base l’unità ignimbritica del villa senni (350 ka), cui si deve il collasso della caldera tuscolano-artemisia al centro dei colli albani. subito dopo la messa in posto del villa senni si ha l’ingressione marina relativa allo stadio 9 che porta alla formazione di una superficie di abrasione al tetto dell’ignimbrite, coperta da sabbie di spiaggia, duna e retroduna (subsintema nuova california), ovvero la duna rossa antica auct. questa superficie è dislocata da faglie ad andamento ne tra pomezia e castelporziano ed oggi si trova a quote comprese tra +60 m s.l.m.e +100 m s.l.m. il sollevamento determina la formazione di una superficie erosiva tra la costa e la bassa valle del tevere, che ospiterà fino ai 280 ka la deposiil quaternario italian journal of quaternary sciences 1166(1bis), 2003, 121-129 122 c. giordano et al. 11.. iinnttrroodduuccttiioonn the roman coastal area extends between the sabatini volcanoes to the north and the colli albani volcano to the south, along the tyrrhenian coast of central italy (fig. 1). excellent exposures of quaternary sedimentary successions occur in the area and offer the opportunity to analyse the interplay between eustatism, tectonics and volcanism. since the early fifties, many different interpretations have been proposed on the number and significance of the sedimentary successions, based each time on new exposures and new age determinations. table 1 is a synoptic scheme of the main stratigraphic interpretations. open questions concern the hierarchy of the unconformities and their relationship to glacial periods (blanc, 1957; ambrosetti & bonadonna, 1967; manfredini, 1990; karner & renne, 1998; karner et al., 2001a, b), and the internal architecture of the sedimentary successions in relationship with sea level changes and tectonic uplift (e.g., conato et al., 1980; malatesta & zarlenga, 1986; milli, 1997). some workers have pointed out the contribution of volcanism to sedimentary processes (e.g. cavinato et al., 1992; marra & rosa, 1995), while others analysed the geometry of coastal terraces related to the pleistocene sea level oscillations (e.g. basili & bosi,1996). several faunal units have been based on the well preserved vertebrate fossil remains occurring within the pleistocene roman sedimentary successions and, together with archeological findings, they have been used for detailed paleoenvironmental reconstructions (cavarretta et al. 2001 and references therein). this paper focuses on the middle to upper pleistocene sedimentary succession of the roman area and syntethises data from more than two thousand stratigraphic sections, measured in an area of approximately 1500 km2. the proposed hierarchy of the unconformities is based on their lateral extension and morphologic relief, and on the facies associations of the enclosed rock bodies. 22.. mmeetthhooddoollooggyy starting from 0.6 ma, the roman coastal area has received volcaniclastic sedimentation from the two volcanic areas of the sabatini to the north and of the colli albani to the south. the presence of volcaniclastic deposits transitional to volcanic deposits and to coastal sediments has allowed the correlation of volcanic activity and coastal sedimentation and the understanding of how volcanism, eustatism and tectonics acted in the evolution of the area. some of the large erupted volume pyroclastic flows reached the coastal area and the deposits are interbedded with the coastal sediments. the geochronologically dated volcanic units have been used to constrain the time range of deposition of the hosting sedimentary successions. lithostratigraphic units have been organised as unconformity -bounded stratigraphic units (ubsu). the most widespread erosional surfaces in the roman area during middle to upper pleistocene are related to the low stands of the sea level. these unconformities bound the synthems, i.e. the fundamental ubsu in respect to which the hierarchy of the other unconformities is referred (salvador, 1987). vertical tectonic displacements may locally enhance or reduce the field evidence of unconformities. the correlation of the synthem to glacio-eustatic variations of the sea level is important, as the hierarchy of unconformities is referred to a geological process. each recognised synthem has been correlated to the oxygen isotope scale (pisias et al.1994; shackleton 2000) on the basis of available geochronological and /or paleontological data. lateral facies relationships between volcanic units and volcaniclastic sediments have allowed the distinction of syn-eruption and inter-eruption successions related to the volcanic activity of the colli albani and of the sabatini volcanoes (cf. smith, 1987; giordano et al., 2002a). where historical formational or unit names are not misleading, we have retained the traditional name for the synthem (for example our ponte galeria synthem coincides with the ponte galeria formation auct.), whereas we have changed it where names may induce confusion (for example the s. cosimato formation auct. has been interpreted in many different ways, and means different things to different authors.). 33.. mmiiddddllee ttoo uuppppeerr pplleeiissttoocceennee,, ssttrraattiiggrraapphhiicc aanndd tteeccttoonniicc eevvoolluuttiioonn ooff tthhee rroommaann aarreeaa the transition from marine to continental environments in the roman area occurred with the deposition of the ponte galeria synthem between approximately 850 and 700 ka (cf. the ponte galeria formation by conato et al., 1980;. table 1). the ponte galeria synthem represents the sedimentation of a paleo-tiber river delta (e.g. marra & rosa, 1995; milli, 1997) fed from the north. the deposits of this unit are described in a number of papers (table 1) and range from fluvial conglomerate and sand to lagoonal clay and beach sand and gravel. the ponte galeria synthem encomzione dei subsintemi aurelia e vitinia la cui quota di tetto è compresa tra i 40 m ed i 60 m s.l.m. questo terrazzo sutura, o quasi, le dislocazioni tra pomezia e castelporziano, che dunque determinarono un innalzamento relativo di 140+/-5 m in circa 70 ka, al tasso di circa 2 mm/a. successivamente la regione va incontro a sollevamento generalizzato che, in concomitanza con le oscillazioni del mare, ha consentito la conservazione di terrazzi incassati sia lungo la costa che lungo la valle del tevere, dove i sedimenti relativi allo stadio 7 formano il sintema campo selva oggi posti tra 30 m e 40 m s.l.m., mentre i depositi relativi allo stadio 5 formano il sintema saccopastore, oggi riconoscibili tra quota 15 m e 30 m s.l.m. il tasso calcolato regionale di sollevamento è di 0.2 mm/a in accordo con quanto noto per il litorale laziale a nord ed i dati noti del tirreniano. key-words: sedimentation, volcanism, tectonics, eustatism, quaternary parole chiave:, sedimentazione, vulcanismo, tettonica, eustatismo, quaternario passes several sea level oscillations (at least from stage 20 to stage 17; marra et al., 1998), although compensated by subsidence. the synthem forms an aggradational wedge up to 80 m thick. between ca. 700 and 600 ka, the uplift of the nw-trending mt. mario rise tilted the block by few degrees toward the w-sw, and caused the diversion of the paleo-tiber river toward the southeast (giordano et al., 2002b), along the crescenzatorrenova paleovalley (fig. 1). the former ponte galeria delta was therefore isolated from the river system and formed a plateau sloping toward the sea (fig. 1). as a consequence of the uplift, a high relief erosion surface formed, preserved today to the w and the s of the plateau. the unconformity is mostly represented by v-shaped paleo-gullies. the overlying sedimentary succession is made up by an aggradational and fining upward succession of fluvial to lacustrine sediments, mainly derived from the underlying ponte galeria synthem, with increasing upward volcaniclastic sediments derived from the early explosive eruptions from the sabatini and colli albani volcanoes. this succession is named “s.cecilia synthem” (cf. marra & rosa, 1995) and can be correlated with the isotopic stage 15 (fig. 1), on the basis of interbedded ignimbrites dated between 561+ -1 ka and 548 + 4 ka (karner et al., 2001b). the largest of those volcanic deposits are the trigoria eruption unit and the tor de cenci eruption unit from colli albani (de rita et al., 2002a), and the tufo giallo della via tiberina eruption unit from the sabatini (de rita et al., 1993; karner et al. 2001a). the mt. mario rise prevented ignimbrites from the sabatini volcanoes (namely the tufo giallo della via tiberina) to reach the area to the south and west of rome, and diverted the pyroclastic flows along the paleo-tiber river, where the ignimbrites occur with remarkable thickness. the river diversion gave also rise to lacustrine environments, influencing the phreatomagmatic character of the early volcanic activity of the colli albani volcano (de rita 123the sedimentation along the roman coast ... figure 1 dem of the study area (courtesy of esrin) and schematic interpretation of the main structural, volcanic and geomorphologic features (see text for explanation). 124 et al., 2002a). the lowest elevation of the basal unconformity of the santa cecilia synthem occurs at 18 m a.s.l. in the ponte galeria area where the succession is maximum 32 m thick in outcrop. the same unconformity is located at – 80 m in respect to sea level (r.s.l.) to the east of the mt. mario rise, where the succession is more than 45 m thick, as inferred from borehole data. these data indicate that vertical tectonic displacements occurred during and after the deposition of the santa cecilia synthem. the growth of the colli albani volcano caused the progressive shift of the paleo-tiber back northward, where the river crossed the mt. mario rise in a position similar to present day. from then onwards, all river terraces relative to the following aggradational periods are found both along the right and the left river banks of the present course of the tiber river, testifying that little shifts have occurred ever since. the following synthem, named “valle giulia” (cf. marra and rosa, 1995), comprises an aggradational and fining upward succession of fluvial deposits, volcanic units and several travertine plates, related to the presence of hydrothermal system. the thickness of the fluvial succession is up to 30 m. the most widespread volcanic units present within this synthem, the palatino phreatomagmatic unit, the casale del cavaliere eruption unit (de rita et al., 2002a) and the tufo giallo di prima porta (karner et al., 2001b) are dated at around 528+ -1 table 1 comparison between the stratigraphy proposed in this paper and previous interpretations. and 514+ -3 ka (karner et al., 2001b), which constrain the synthem to the isotopic stage 13 (table 1). the lowest elevation of the basal unconformity of the valle giulia synthem is presently at approximately 10 m a.s.l., whereas it is downthrown by some tens of metres to the east of the mt mario rise. vertical tectonic displacements during and after the valle giulia emplacement determined the development of subsiding sectors mostly along ne-trending and nw-trending faults. the successive synthem, named “torrino” encompasses an aggradational and fining upward succession of mostly volcaniclastic sediments and volcanic deposits relative to large lava flows (vallerano lava flows; fosso tre rami lava flows; cf. de rita et al., 1995) and large volume, caldera forming explosive eruptions (pozzolane rosse and pozzolane nere eruption units) from the colli albani, as well as from the sabatini (tufo rosso a scorie nere eruption unit). this synthem is constrained at the stages 12 and 11 (tab. 1), on account of the available age determinations on the volcanic units which span from the 460+ -4 ka for the vallerano lava flow at the base of the synthem, to the 407+ -4 ka for the pozzolane nere at the top (data from karner et al., 2001b to be compared with voltaggio and barbieri, 1995 and reference therein). the basal unconformity of this synthem is today at 10 m a.s.l., and the maximum thickness in outcrop of the fluvial succession is 30 m. the synthem does not appear to record the occurc. giordano et al. 125 rence of important vertical tectonic displacements. the torrino synthem is cut by an erosion surface which is the basal unconformity of the successive synthem, named “quartaccio”. the formation of the erosion surface is chronologically well constrained at the low stand of stage 10 by the presence on top of the surface of the large volume and caldera-forming tufo lionato-villa senni ignimbrites from the colli albani. these ignimbrites have been dated several times with different techniques at around 350 ka (e.g. bernardi et al., 1982; radicati di brozolo et al., 1981; karner and renne, 1998). the tufo lionato-villa senni (tl-vs) ignimbrites locally rest on beach-sand and marine sediments (nuova california unit) which record the sea level at ca. 350 ka (fig. 2), evaluated, according to wealbroeck et al. (2002), at –120 m r.s.l. (cfr. fig. 4). in the pomezia-castelporziano area, several sedimentary units at different elevations are related to the subsequent marine ingression relative to the isotopic stage 9. this probably records the contemporaneous uplift of the pomezia-castelporziano rise with respect to the ardea-basin along ne-trending faults (figs. 1, 2 and 3). in this area, an abrasion surface at the top of the tlvs ignimbrites, is covered by dunalto retro-dunal-sand (the castelporziano unit; i.e. “duna rossa antica” or “older dune” auct.), which is presently uplifted to up to 100 m a.s.l. (figs. 2 and 3), and which can be related to any moment between the low stand 10 and the following high stand 9. the uplift isolated the pomeziacastelporziano block, against which the aurelia unit was deposited. the aurelia unit forms a fluvial to marine terrace, presently visible along the tiber river valley (figs. 1, 2 and 3). the lowest elevation of the basal unconformity of the aurelia unit is at 10 m a.s.l. whereas the top reaches 50 m a.s.l. the aurelia unit is generally overlain by the vitinia unit, a sedimentary aggradational succession, rich in volcaniclastic sediments mostly derived from the contemporaneous activity of the faete epoch of the colli albani volcano (ca 350-270 ka; de rita et al., 1995). the aurelia and the vitinia units are separated by a low relief unconformity surface, which never cuts lower than the aurelia basal unconformity (fig. 2), and which outcrops at 30 m a.s.l. at the lowest. the top of the vitinia unit reaches 55-60 m. at the top of the vitinia unit, the scatter presence of a pumice fallout deposit related with the tufo giallo di sacrofano from the sabatini volcanoes (de rita et al., 1993) dated at 285+ -1 (karner et al., 2001b), constrains the vitinia unit to the stage 8.5, i.e. a secondary warm peak occurred during the cooling that led to the low stand relative to the isotopic stage 8 (fig. 4 and table 1). the 55-60 m surface, which corresponds to the top of the vitinia unit can also be recognised along the seaside margin, facing west, as a continuous surface which sutures the displacements of the pomezia-castelporziano high. this surface constrains the pomeziacastelporziano uplift to a time span comprised between the deposition of the tlvs ignimbrites (at 350 ka) and the vitinia unit (at 280 ka) (figs. 1, 2 and 3). the more recent terraces are preserved at progressively lower elevations (figs. 1 and 3) indicating that regional uplift re-started after the deposition of the vitinia unit at the top of the quartaccio synthem. two marine terraces are preserved along the coast at 30-40 m a.s.l. (“campo selva” synthem) and 15-30 m a.s.l. respectively (saccopastore” synthem) (fig. 3). the sediments relative to the campo selva synthem are visible in a number of quarries (e.g. tacconi quarry) but bear no datable volcanics or fossils, so that the age constrain is not well defined although it appears logical to figure 2 stratigraphy and geomorphology of the quartaccio synthem across the pomezia-castelporziano high and the tiber river valley (see fig. 1). the tufo lionato ignimbrite emplaced at sea level over wet marineto beach-sediments, at 350 ka, during the low stand 10 of the sea level, and was then overlain by dune sand before it was uplifted to form the erosion surface (dashed line) inside which the aurelia and vitinia subsynthems are infilled. the sedimentation along the roman coast ... 126 relate it to the stage 7. along the tiber river no fluvial terrace that can be safely correlated with this stage. the age of the saccopastore synthem, the lowest terrace (figs. 1 and 3), is constrained at the stage 5a by the presence of strombus bubonius fauna reported by blanc (1936) from the north of the tiber river (casal di statua, 19 m a.s.l.). in the city of rome, along the course of the tiber river, several fluvial terraces occurring at an average elevation of 35 m a.s.l, can be related to this stage. in this deposits the “man of saccopastore”, a neanderthal man dated at about 100 ka, was found (blanc, 1942). 44.. ddiissccuussssiioonn aanndd ccoonncclluussiioonnss regional uplift, local tectonics, eustatism and volcanism, acted during the middle to upper pleistocene geologic evolution of the roman area. the correlation of the basal unconformity of synthems to periods of low standing of the sea level has, as constrained by tephrachonologic data, allowed the evaluation of the relative role of regional uplift versus local tectonics. in table 2 we have computed the amount and the rate of vertical uplift for several stratigraphic surfaces. the error bar for each computed value, is given by the maximum and minimum elevations of the top or the base of the terrace, on the time span of deposition. this time span is taken conservatively to encompass the peaks of the oxygen isotopic stage on the curve of waelbroek et al., (2002). the present day elevation of the top of the marine terraces related to the stages 5a (15-30 m a.s.l. for the saccopastore synthem), 7 (35-45 m a.s.l. for the campo selva synthem) and 9-8.5 (55-60 m a.s.l. for the quartaccio synthem) are similar along the whole roman coast, both to the north and to the south of the tiber river delta and therefore are related to regional uplift. the computed uplift rate averages at 0,2 mm/y, and appears to be constant since the vitinia unit emplacement, i.e. approximately since 280 ka (tab. 2 and fig. 4). this value is well comparable with the regional uplift rate computed for the 125 ka marine terrace by bordoni and valensise (1998), as well as with stratigraphic and geomorphologic data from the coast of northern latium, where, similarly, three orders of terraces related to stages 9, 7 and 5 are present at comparable elevations (de rita et al., 2002b). it must be underlined that similar values are also known from geoarchaeological studies of roman times remains (anzidei et al., 2002). on the contrary, the uplift of the pomeziacastelporziano high along ne-trending faults, which most likely re-activated the pliocene-lower pleistocene masterfaults of the adjacent ardea basin (faccenna et al., 1994) (fig. 1 and fig. 3) is a localised tectonic process, that occurred shortly after the eruption of the tufo lionato-villa senni ignimbrites and the collapse of the colli albani caldera at 350 ka. the computed uplift rate is high, at 2 mm/y, which implies a fast and discrete event, possibly related to volcano-tectonic processes. today, the area is still affected by intense hydrothermal activity (e.g. chiodini & frondini, 2001; quattrocchi et al., 2001) aligned along the main ne-trending faults. the older santa cecilia synthem (stage 15), valle giulia synthem (stage 13) and torrino synthem (stage 11), do not show important intervening regional uplift, except for localised mto 10 m-scale faulting. taking into consideration that the deposition of the three synthems hosted the largest volume of erupted products figure 3 block diagram of the pomezia-castelporziano high illustrating the geometric relationships among terraces relative to stages 9-8.5, 7 and 5. c. giordano et al. both from the sabatini volcanoes and the colli albani volcano (tuscolano-artemisio epoch, 600-350 ka; cf. de rita et al., 1995) it may be proposed that high eruption rates likely associated with high heat flow are favourable conditions for compensating isostatic uplift at regional scale. small scale faults also indicate a relative tectonic quiescence, whereas the development of large caldera complexes at the colli albani and sabatini volcanoes indicates the prevailing of volcano-tectonics. the localised and fast uplift of the nw-trending mt. mario rise occurred instead between 700 and 600 ka (giordano et al., 2002b) and has characteristics very similar to the uplift of the pomezia-castelporziano high. the unconformity generated by the mt. mario uplift has high relief but it is only present at the margins of the ponte galeria plateau (fig. 1) and bears no regional significance. instead, it could be related to volcano-tectonic processes which occurred just before the beginning of the volcanism in the area. with respect to previous interpretations, this reconstruction implies: 1. the recognition of eustatism as the main factor able to produce, in this area, regionally widespread unconformity surfaces, as sea level oscillated by over 100 m with a cyclicity of approximately 100 ka. these unconformities bound synthems. instead, local tectonics is responsible for the formation of high relief although localised unconformities. the best example of these two processes is the quartaccio synthem (figs. 2 and 3). this synthem is regionally represented by a terrace deposited during the oxygen isotopic stage 9, with the top at approximately 60 m a.s.l. (cf. de rita et al., 2002b). on the other hand, in the pomezia-castelporziano area, the synthem is made of several units because the area uplifted during the rise of the sea level which occurred between the low stand relative to stage 10 and the high stand relative to stage 9. as a consequence, the “older dune auct.” (table 1), which corresponds to our castelporziano dune sand, was not deposited during the “tyrrhenian” (<125 ka), but it is older, with obvious implications, as discussed above, in respect to the timing and the rate of uplift required to attain the present day elavation (max. 100 m a.s.l.; figs. 1 and 2). 2. the aurelia and the vitinia units are two distinct subsynthems, although part of the same quartaccio synthem. they can be respectively correlated to sea level high stand peaks attained during stages 9 and 8.5 (fig. 4). this new interpretation implies the chronologic constrain of the deposition of the vitinia unit at >280 ka, making the vitinia unit older than commonly thought, with large implications for the bio-stratigraphy of the area (e.g. gliozzi et al., 1997; di stefano et al., 1998; cavarretta et al., 2001 and references therein). this interpretation easily justifies several lines of evidence, such as the very low relief erosion surface at the base of the vitinia unit, which never cuts lower than the basal unconformity to the aurelia unit, the evident morphologic unity of the two units forming a single terrace with its top at 55-60 m, easily recognisable from the coast to the fluvial environment (fig. 1), and the age determinations on the interbedded of volcanic horizons, which are always older than 250 ka (cf. karner and marra, 1998). 3. the presence of a larger volcaniclastic component in the vitinia unit in respect to the underlying aurelia 127 figure 4 sea level oscillation according to waelbroeck et al., 2002 and succession of sedimentary and tectonic events in the roman coastal area after the emplacement of the tufo lionatovilla senni ignimbrites. table 2 computed uplift rates for different stratigraphic surfaces. the base of the quartaccio synthem is taken as representing the sea level during the low stand 10, whereas the successive surfaces as sea levels during high stands 8.5, 7 and 5 respectively. ssyynntthheemm uunniitt ssuurrffaaccee eelleevvaattiioonn aaggee ((kkaa)) uupplliifftt ((mm)) uupplliifftt rraattee ccoommmmeenntt ((mm aassll)) mmiinn mmaaxx ((mmmm//yy)) saccopastore top (15-30) 130 80 * 15 30 0,22 +/0,13 regional uplift campo selva top (35-45) 230-190 * 5 30 0,20 +/0,2 regional uplift quartaccio vitinia top (55-60) 284 +/3 ** 10 25 0,23 +/0,15 regional uplift quartaccio nuova california base (80) 351 +/3 *** 135 145 2,0 +/0,2 local uplift * corresponding to sea level high stands from waelbroeck et al., 2002 ** karner et al., 2001a *** villa, 1992 the sedimentation along the roman coast ... unit is also well in agreement with the datation of the first products (e.g. the capo di bove lava flow dated at 277 ka; voltaggio & barbieri, 1995 and references therein; karner et al., 2001a), which overflowed the caldera rim relative to the villa senni eruption. similarly to many other calderas, such as the campi flegrei and taupo (n.z.), volcanic activity immediately after the collapse of the caldera, and usually for several thousands of years, is confined within the collapsed area, so that outside the volcaniclastic sedimentation is greaty reduced. this time-gap therefore just represents the time necessary to the caldera to be filled by deposits, and is recorded by the marked increase in volcaniclastic sediments in the vitinia unit in respect to the aurelia unit. 4. during the middle-upper pleistocene in the roman area deformation processes result from the competition among regional uplift, localised tectonics, likely related to volcano-tectonic processes, and eruption rates (i.e. heat flow rate). the whole region, since lower pleistocene, has experienced a general tendency to regional uplift, which appears to be less significant during the climax of volcanic activity (between 600 and 300 ka ;cf. cavinato et al., 1994). the uplift resumed later (stages 9, 7 and 5) at a rate of 0.2 mm/y, suggesting that volcanism in the area, although still affected by an important hydrothermal activity (e.g. funiciello et al., 2002) is coming to an end. this is also evident by the generalised reduction of eruption rates of the latian volcanoes during the upper pliestocene (derita et al., 1995). this interpretation is substantially different from that proposed in a recent paper by karner et al. (2001b), who, based on the analyses of one stratigraphic section located in the ponte galeria area, attributed the uplift occurring after stage 9 to a refill of the magma chamber of the colli albani volcano and therefore claimed possible volcanic hazard. our data indicate instead that the resumption of uplift is a regional process occurring along the whole latian coast, not at all exclusive to the colli albani area, and well in agreement with the waning of the volcanism. 55.. aacckknnoowwlleeddggeemmeennttss the authors would like to thank s. rodani, p. paccara, p. pieruccini, r. basili and p. marsili, for discussion in the field. this work has partly been performed under the auspices of the carg project, for which we thank m. parotto. we also thank the two anonymous reviewers of the original manuscript. bbiibblliiooggrraaffiiaa ambrosetti p. & bonadonna f.p. (1967) revisione dei dati sul plio-pleistocene di roma. atti acc. gioe. di sc. nat. catania, ser. 66, 18, 33-72. anzidei m., esposito a. & benini a. (2002) using roman age submerged structures as leveling benchmarks: interaction between recent sea level variations and crustal deformation. 2002 egs general assembly, nice. abstract volume. basili r. & bosi c. (1996) morfo-litostratigrafia dell’area romana in sinistra tevere il quaternario, 99 (1), 273-280. bernardi a., de rita d., funiciello r., innocenti f. & villa i.m. (1982) chronology and structural evolutioin of albano hills volcanic complex. latium italy. workshop on the esplosive volcanism, s. martino al cimino. abstract blanc a.c. (1939) una spiaggia pleistocenica a strombus bubonius presso palidoro (roma); rend. r. acc. lincei, 2233, pp, 200 e seg.. blanc a.c. (1942) notizie sui trovamenti e sul giacimento di saccopastore e sulla sua posizione nel pleistocene laziale. paleontographia italica. memoria n. 1 l'uomo dl saccopastore; volume xlii (nuova serie, vol. xii) pag. 1-24, 3 fig. blanc a.c. (1957) on the pleistocene sequence of rome paleoecologic and archeologic correlations. quaternaria, 44, 95-109. bordoni p. & valensise g. (1998) deformationof the 125 ka marine terrace in italy: tectonic implications. in stewart i.s. . & vita-finzi c. (eds) – coastal tectonics. geological society of london, spec. publ., 114466, 71-110. cavarretta g., gioia p., mussi m. & m,r, palombo (2001) la terra degli elefanti. atti del i° cong. int. roma, cnr cavinato g.p., de rita d., milli s. & zarlenga f. (1992) correlazioni tra i principali eventi tettonici, sedimentari, vulcanici ed eustatici che hanno interessato l'entroterra (conche intrappenniniche) e il margine costiero laziale durante il pliocene superiore ed il pleistocene. studi geol. camerti, volume speciale (1992/1),109-114. cavinato g.p., cosentino d., de rita d., funiciello m. & parotto m. (1994) tectonic-sedimentary evolution of intrapenninic basins and correlation with the volcano-tectonic activity in central italy. mem. descr. geol. d’it. xlix, 63-76 chiodini g. & frondini f. (2001) carbon dioxide degassing from the albani hills volcanic region, central italy. chem. geol., 111177,, 67-83. conato v., esu d., malatesta a. & zarlenga f. (1980) new data on the pleistocene of rome. quatemaria, 2222,131-176. de rita d., funiciello r., corda l. & sposato a.. (1993) sabatini volcanic complex. di filippo m. (ed.), c.n.r. quad. ric. sc. p.f. geod. vol. 1111, 3378 de rita d., faccenna c., funiciello r. & rosa c. (1995) stratigraphy and volcano-tectonics. in trigila r. (ed.), the volcano of the alban hills, tipografia sgs, roma: 33-73. de rita d., giordano g., esposito a., fabbri m. & rodani s.(2002a) large volume phreatomagmatic ignimbrites from the colli albani volcano (middle pleistocene, italy). j. volcanol. geotherm. res. 2487, 1-22 de rita d., fabbri m., mazzini i., paccara p., sposato a & trigari a.(2002b) volcanoclastic sedimentation in coastal environmental: the interplay between volcanism and quaternary sea level change (central italy) quat. int., 95-96, 141-154. di stefano g., petronio c. & sardella r. (1998) biochronologyof the pleistocene mammal faunas from rome urban area. il quaternario, 1111 (2), 191128 c. giordano et al. 199. faccenna c., funiciello r., bruni a., mattei m. & sagnotti l. (1994) evolution of a transfer-related basin: the ardea basin (latium, central italy). basin research, 66, 35-46. funiciello r., de rita d. & giordano g. (2002) the albano maar lake (colli albani volcano, italy): recent volcanic activity and evidences of preroman age catastrophic lahar events. j. volcanol. geotherm. res (in press) giordano g., de rita d., fabbri m. & rodani s. (2002a) facies associations of rain generated versus crater lake-withdrawal lahar deposits from quaternary volcanoes, central italy. j. volcanol. geotherm. res., 2490, 1-15. giordano g., esposito a., de rita d., fabbri m., mazzini i., paccara p., funiciello r. (2002b) evoluzione geologica del margine tirrenico laziale tra il pleistocene inferiore e medio. riassunti del convegno fist, torino 2002. gliozzi e., abbazzi l., argenti p., azzaroli a., caloi l., capasso barbato l., di stefano g., esu d., ficcarelli g., girotti o., kotsakis t., masini f., mazza p., mezzabotta c. palombo m.r., petronio c., rook l., sala b., sardella r., zanalda e. & torre d. (1997) biochronology of select mammals, molluscs and ostracods from the middle pliocene to the late pleistocene in italy.the state of art. riv. it. di paleon. e str. , 110033, 368-388. karner d., renne p.r. (1998) 39ar/40ar geochronology of roman volcanic province tephra in the tiber river valley: age calibration of middle pleistocene sea-level changes. geol. soc. am. bull.; 110: 740747. karner d.b., marra f., florindo f. & boschi e. (2001a) pulsed uplift estimated from terrace elevations in the coast of rome: evidence for a new phase of volcanic activity?, earth and planetary science letters 118888 (1-2), 135-148. karner d., marra f. & renne r. (2001b) the history of the monti sabatini and alban hills volcanoes: groundwork for assessing volcanic-tectonic hazards for rome. j. volcanol. geotherm. res. 110077 (1-3), 185-215. malatesta a. & zarlenga f. (1985) il quaternario di pomezia (roma) e la sua fauna marina. boll. soc. geol. it., 110044, 503-514. malatesta a. & zarlenga f. (1986) evoluzione paleogeografico-strutturale pliopleistocenica del basso bacino romano a nord e sud del tevere. mem. soc. geol. it., 3355, 75-85. manfredini m. (1990) idrografia pleistocenica della bassa valle del fiume tevere (italia centrale). il quaternario, 33, 39-59. marra f. & rosa c. (1995) stratigrafia ed assetto geologico-strutturale dell'area romana compresa tra il tevere ed il rio galeria. geol. rom., 2299, 515-535. marra f., florindo f. and karner d. b. (1998) paleomagnetism and geochronology of early middle pleistocene depositional sequences near rome: comparison with the deep-sea δ18o record. earth and planetary science letters 115599 (3-4) (1998) pp. 147-164 milli s. (1997) depositional setting and high-frequency sequence stratigraphy of the middle-upper pleistocene and holocene deposits of the roman basin. geol. rom., 3333,, 99-136. pisias n.g., martinson d.g., moore jr. t.c., shackleton n.j., prell w., hays j. e boden g. (1994) high resolution stratigraphic correlation of benthic oxygen isotopic records spanning the last 300,000 years. marine geology 5599, 217-233. quattrocchi f., galli g., pizzino l., capelli g., de rita d., faccenna c., funiciello r., giordano g., goletto d., mazza r., mancini c. (2001) the ardea basin fluid geochemistry, hydrogeology and structural patterns: new insights about the geothermal unrest activity of the alban hills quiescent volcano (rome, italy) and its geochemical hazard surveillance. proc. x intern. conf. waterrock-interaction, villasimius, balkema ed.: 11-13. radicati di brozolo f., huneke j.c., papanastasiou d.a., wasserbutg g.j. (1981) 40ar/39ar and rb/sr age determinations on quaternary volcanic rocks. epsl, 5533, 445-456. salvador, a. (1987) unconformity bounded stratigraphic units. geol. soc. am. bull., 9988, 232237. shackleton n.j. (2000) the 100.000 year ice-age cycle identified and found to lag temperature, carbon dioxide, and orbital ecentricy. science 289, 1897-1902. smith g.a. (1987) the influence of explosive voccanism on fluvial sedimentation: the deschutes formation (neogene) in central oregon. journ. sedim. petrol., 5577, 613-629. voltaggio m., barbieri m., 1995, geochronology. in: r. trigila (ed.), 1995 the volcano of the alban hills, tipografia sgs, roma: 167-193. waelbroeck c., labeyrie l., michel e., duplessy j.c., mcmanus j.f., lambeck k., balbon e. & labracherie m. (2002) sea level and deep water terperature ghanges derived from benthic foraminifera isotopic records. quat. sc. rev. 2211, 295305. 129the sedimentation along the roman coast ... imp. bizzarri & ll’’aaffffiioorraammeennttoo ddeell ccaaiioo ((llaaggoo ddii ccoorrbbaarraa,, oorrvviieettoo,, iittaalliiaa cceennttrraallee)) nneellll’’aammbbiittoo ddeellll’’eevvoolluuzziioonnee ppaalleeooggeeooggrraaffiiccaa pplliioo –– pplleeiissttoocceenniiccaa ddeellllaa vvaallllee ddeell tteevveerree:: eevviiddeennzzee sseeddiimmeennttoollooggiicchhee ee ssttrraattiiggrraaffiicchhee rroobbeerrttoo bbiizzzzaarrrrii11**,, ppiieerrlluuiiggii aammbbrroosseettttii11****,, ppaattrriizziiaa aarrggeennttii11******,, ggiiaaccoommoo ddiieeggoo ggaattttaa22 && aannggeellaa bbaallddaannzzaa11******** 1dipartimento di scienze della terra, università di perugia, p.zza università, 1, 06100 perugia, *roberto.bizzarri@libero.it, **pambrose@unipg.it, ***biogeo@unipg.it, ****abaldanz@unipg.it 2bayerisches geoinstitut, universität bayreuth, universität strasse, 30 d95447 bayreuth, germany, diego.gatta@uni-bayreuth.de riassunto l’affioramento del caio (lago di corbara, orvieto, italia centrale), per i suoi peculiari caratteri sedimentologici e stratigrafici, suggerisce un riesame del contesto paleoambientale e paleogeografico dell’area durante il pliocene superiore – pleistocene inferiore. l’affioramento, situato a circa 6 km dall’abitato di corbara, mostra una successione di depositi marini e continentali del pliocene medio – superiore e pleistocene inferiore, passanti da sabbie, a sabbie argillose, ad argille e infine a ghiaie, riferibili alle unità delle “sabbie a flabellipecten” e delle “argille e sabbie del chiani – tevere” (ambrosetti et al., 1987). la parte finale della successione, affiorante all’interno di una piccola cava, è costituita da diversi corpi ghiaiosi, che sono stati interpretati come depositi della parte medio prossimale di un conoide alluvionale, probabilmente deposti in un breve intervallo temporale. sia nelle argille che nelle ghiaie sono state inoltre rinvenute piroclastiti. e’ stata effettuata sia un’analisi di facies che uno studio biostratigrafico; inoltre, i campioni contenenti materiale vulcanoclastico sono stati oggetto di indagini mineralogico cristallochimiche, eseguite in diffrattometria a raggi-x da polveri e in microscopia elettronica a scansione (sem-eds). il rinvenimento di hyalinea balthica e nannoplancton calcareo del pleistocene inferiore basale all’interno di depositi riferibili alle “argille e sabbie del chiani – tevere”, il ritrovamento di piroclastiti a probabile affinità toscana, ed infine la presenza di depositi continentali di età confrontabile con quella delle argille forniscono nuovi dati utilizzabili per la ricostruzione dell’evoluzione paleogeografica dell’area durante il pliocene superiore – pleistocene inferiore abstract the caio outcrop (corbara lake, orvieto, central italy) in the plio – pleistocene palaeogeographic evolution of tiber valley: sedimentological and stratigraphical evidences. the caio outcrop (corbara lake, orvieto, central italy) suggests a re-evaluation of the palaeoenvironmental and palaeogeographical scenery during the late pliocene – early pleistocene induced by its peculiar sedimentological and stratigraphical feature. the outcrop is located about 6 km from the corbara village, and shows a succession of marine and continental deposits, varying from sands, to clayey sands, to clay and finally to gravels. the latest part of caio succession, made of several gravel bodies, outcrops into a small abandoned quarry. both clay and gravel bodies contain pyroclastic material. a facies analisys, based on sedimentological and palaeontological features, and a biostrathigraphic study have been made; moreover , the samples with volcanoclastic material were object of sem – eds analisys and x-ray diffrattometry for mineralogical and petrological determination. on the basis of paleontological content, the sand sediments (from 0 m to 15 m) are referred to the “sabbie a flabellipecten” unit (ambrosetti et al., 1987) for the presence of pecten (flabellipecten) flabelliformis (brocchi) in assemblage with common amphistegina sp. and benthic microforaminifers typical of detritical environments (conti et al., 1983). the overlaying clayey sand sediments (from 15 m to 17.5 m), in spite of the lack of flabellipecten, for their macropaleontological content, with no particular variation in respect to underlying sands, are here related to “sabbie a flabellipecten” unit; however, some problems still remain about their stratigraphical attribution. the following (from 17.5 m to 23 m) clay sediments are instead referred to the “argille e sabbie del chiani – tevere” unit (ambrosetti et al., 1987). the presence of amusium sp., globorotalia inflata (d’orbigny), common bulimina marginata and b. elegans, gephyrocapsa oceanica, helicosphaera sellii and calcidiscus macintyrei allows the identification of early pleistocene age; this age attribution is supported by the finding of hyalinea balthica from 19.50 m. the pliocene – pleistocene boundary is hypothetically placed at 18.50 m, in the lower part of clay sediments. the gravel bodies (from 23 m to 29 m) are interpreted as middle – proximal alluvial fan deposits, probably deposited over a short time period. their age attribution is still an open problem, but some considerations could be made: 1) the reworked microfossil assemblages contain only middle pliocene – early pleistocene specimens, accompained by h. balthica; 2) the younger clastic components of gravel bodies come from middle – upper pliocene biocalcarenites (amphistegina level sensu conti et al., 1983); 3) the pyroclastites, found from 17.5 m to 29 m, contain the same pyroxenes not altered with typical habitus, showing no or only little abrasion; 4) on the basis of preliminary mineralogical and petrological data, it is possible to make some generalizations on the affinity of the volcanic products with the neighbouring magmatic provinces (hks-roman comagmatic province; ksmonti vulsini, roccamonfina, ventotene; tuscan magmatic province; ulud-umbria-latium ultra-alkaline district). the presence of ortopyroxenes suggest, for at least part of the pyroclastites, a tuscan affinity and consequently an older age. on the other hand, our geological study suggests the probable existence of small eruptive centres in the vicinity; 5) a reworked mollusc assemblage, recorded in the middle-upper part of the caio outcrop, is composed of poor littoral marine and freshwater species, the last ones referable to the early pleistocene. these considerations, although a middle pliocene age is not totally rejectable, allow the hypothesis of an early pleistocene age (upper emiliano siciliano) for alluvial – fan deposits, with the consequence of a minimal age gap in respect to the underliyng marine clay sediments. thus, caio’s gravel bodies could be considered as heteropical to upper part of “argille e sabbie del chiani – tevere” unit. in this way, the upper portion of caio outcrop, still marking a local paleoenvironmental situation, testifies the great lateral variability of early pleistocene deposits, referable to “argille e sabbie del chiani – tevere” unit. could be ipotized a coastal morphology articulation, somehow inherited but surely exasperated by strong tectonics at pliocene – pleistocene boundary: this tectonic phase, with structural axes striking ne – sw to e w, displaced pliocene deposits, that were partially reworked, causing a lateral environmental variability, testified by facies heteropy. in a similar scenery, with clay testifying marine environments of increasing depth from east to west, alluvial – fan complexes, as caio alluvial fan, took place, draining sw or nw and partially reworking different deposits of the same marine basin in which they came, during a regressive phase of marine level. parole chiave: sedimentologia, stratigrafia, conoide alluvionale, pliocene, pleistocene, piroclastiti, umbria occidentale. keywords: sedimentology, stratigraphy, alluvial fan, pliocene, pleistocene, pyroclastites, western umbria. il quaternario italian journal of quaternary sciences 1166(2), 2003, 241-255 242 r. bizzarri et al. 11.. iinnttrroodduuzziioonnee dalla seconda metà degli anni settanta fino agli inizi degli anni novanta l’area è stata oggetto di studio per le sue implicazioni nell’evoluzione dell’italia centrale durante il pliocene ed il pleistocene (ambrosetti et al., 1977; 1978a), sia in chiave neotettonica e geomorfologica (ambrosetti et al., 1978b; cattuto et al., 1979), che stratigrafica (ambrosetti et al., 1987). dai lavori citati emerge una ricostruzione evolutiva abbastanza ben delineata nelle sue linee principali, ma anche un’estrema variabilità nelle caratteristiche dei singoli affioramenti, espressione di numerose, e spesso poco note, situazioni locali (bizzarri, 2001). l’affioramento del caio presenta delle peculiarità, sia dal punto di vista sedimentologico e stratigrafico, che per la presenza di intercalazioni piroclastiche, che lo rendono interessante sia in chiave di interpretazione paleoambientale, sia nell’ottica di una ricostruzione evolutiva dell’area. con questa finalità si è tentato un approccio sedimentologico, tramite analisi di facies, per ricostruire le caratteristiche paleoambientali, affiancato da un’analisi biostratigrafica di dettaglio, tramite foraminiferi planctonici e bentonici, nannoplancton calcareo e malacofaune, che ha permesso di inquadrare cronologicamente la successione. i campioni provenienti dalla porzione terminale, contenenti materiali piroclastici, sono stati oggetto di analisi mineralogico – petrografica tramite microscopia elettronica a scansione (sem – eds) e diffrattometria a raggi – x. appare già chiaro, nonostante gli studi siano ancora in una fase preliminare, come questa situazione getti una nuova luce sia sulla variabilità dei paleoambienti pleistocenici nell’area in esame, sia sull’evoluzione paleoambientale tra i l pliocene superiore ed i l pleistocene inferiore. 22.. iinnqquuaaddrraammeennttoo ggeeoollooggiiccoo ddeellll’’aarreeaa ssttuuddiiaattaa l’affioramento in oggetto è situato nei dintorni di orvieto (fig. 1), nell’umbria occidentale, circa 6 km a nw dell’abitato di corbara. sul versante collinare in sponda sinistra del f. paglia a quota 200 m s.l.m. è situata una piccola cava di ghiaia; da qui parte una carreggiabile che scende in modo graduale, portando, dopo un paio di chilometri, a guadare il f.so del caio. la successione risulta esposta anche a seguito del terrazzamento operato dal f. paglia in tempi recenti. la valle del paglia è stata storicamente interpretata come un graben (funiciello et al., 1981; aa.vv., 1982), delimitato da sistemi di faglie dirette, ad andamento appenninico, attivi probabilmente fin dal pliocene inferiore. un ulteriore sistema di faglie a prevalente carattere estensionale, ad andamento anti appennico, comprendente tra l’altro la vicina faglia all’interno della gola del forello, ne interrompe la continuità, creando un insieme di blocchi, variamente dislocati. questo articolato quadro tettonico probabilmente ha determinato, localmente, movimenti compressivi e/o trascorrenti in un contesto complessivamente estensionale. l’att ività tettonica (ambrosetti et al., 1977; 1978b; cattuto et al., 1979; 1988) si articola in varie fasi: come detto, durante il pliocene inferiore l’azione di faglie dirette creò dei bacini, come appunto la valle attualmente occupata dal basso corso del f. paglia, fortemente subsidenti, dove si impostarono ambienti marini da costieri a relativamente profondi. tra il pliocene medio – superiore e, probabilmente, il pleistocene inferiore, una ripresa dell’attività tettonica determinò un’articolazione ancora più marcata dei paleoambienti, con evidenze di variazioni laterali di facies da francamente continentali, salmastre fino a marine. nell’area del caio, i depositi pliocenici e pleistocenici sono riferibili, rispettivamente, alle unità delle “sabbie a flabellipecten” e delle “argille e sabbie del chiani – tevere” (ambrosetti et al., 1987). 33.. ccaarraatttteerrii sseeddiimmeennttoollooggiiccii ee ssttrraattiiggrraaffiiccii ddeellll’’aaffffiioorraammeennttoo la successione plio – pleistocenica del caio poggia in discordanza su terreni di età miocenica rappresentati nella fattispecie da corpi “torbiditici”. la successione può essere seguita con continuità per uno spessore di circa 30 m, la maggior parte dei quali visibili come taglio stradale; gli ultimi 6 m affiorano invece nella parete di una cava dismessa. nel dettaglio, è costituita da sabbie con intercalazioni ciottolose (spessore circa 15 m), passanti a sabbie argillose (3 m circa), seguite da argille (5 m circa) e ghiaie (6 m, parete di cava). il contatto argille – ghiaie, visibile alla base del piano di cava, è di natura chiaramente erosiva. la parete della cava (fig. 2) si estende in direzione n – s per circa 30 m ed ha un’altezza di 6 m; la sua continuità è interrotta da due piani di taglio, con componente inversa, immergenti verso nord, che rialzano (rigetto apparente circa 50 cm) il blocco settentrionale. mancano completamente dei marker cinematici misurabili, così come una sezione ortogonale alla parete di cava, che permettano di stabilire con precisione l’entità reale del rigetto. sono inoltre ben visibili corpi ghiaiosi con caratteristiche diverse. i corpi sabbiosi alla base della successione e le argille possono essere riferiti rispettivamente alle “sabbie a flabellipecten” e alle “argille e sabbie del chiani – tevere” (ambrosetti et al., 1987); di incerta attribuzione restano al momento le sabbie argillose, interposte tra le due suddette unità, così come i corpi ghiaiosi della cava. le prime sono state riferite alle fig. 1ubicazione dell’affioramento del caio. location of caio outcrop. “sabbie a flabellipecten”, mentre i secondi meritano alcune riflessioni, che sono riportate nel capitolo conclusivo. nella descrizione sedimentologica è stata utilizzata la scala granulometrica proposta da blair & mcpherson (1999) e riportata in tabella 1. ssaabbbbiiee aa ffllaabbeelllliippeecctteenn sabbie con ciottoli la parte inferiore della successione (fig. 3) è costituita nei primi 7 – 8 m da sabbia media – fine (ms), localmente cementata, da sabbia fine (fs) nei metri successivi, per uno spessore complessivo di ~15 m. il colore è giallo ocra, mentre i singoli granuli, da subangolosi a subarrotondati, ad alto sorting, sono in prevalenza frammenti litici, tra cui dominano carbonati e selci. sono presenti numerose intercalazioni ciottolose, con tre differenti tipologie: corpi lenticolari, non ben definiti, costituiti da elementi con diametro 2÷8 mm (classi granulometriche g e fp), presenti in tutto il livello: lo spessore è sempre modesto (max 10 cm), mentre lo sviluppo laterale è variabile. livelli a geometria piano – convessa, con spessore nella parte centrale 10 cm max, larghi poche decine di centimetri, costituiti da granuli (g), con un abbozzo di laminazione (presenti tra il metro 2,5 e il metro 3). livelli a base erosiva, con geometria lenticolare, spessore e persistenza variabili, con gradazione diretta, sia in senso verticale che laterale: la granulometria passa infatti da fp a g. litologia (litotipi carbonatici con subordinate areniti nella classe fp, prevalenza di selce nella classe g) ed arrotondamento (elementi da subarrotondati a molto arrotondati, ad eccezione della selce che appare sempre da subangolosa ad angolosa) sono elementi tessiturali comuni a tutte le intercalazioni ciottolose. si rinvengono frequenti ostreidi di grandi dimensioni ed altri bivalvi prevalentemente integri, insieme ad accumuli locali di frammenti. questo livello suggerisce la sedimentazione in un ambiente marino costiero poco profondo, riferibile ad una shoreface superiore; i materiali più grossolani almeno in parte sembrano testimo243l’affioramento del caio ... niare una rielaborazione ad opera del moto ondoso (dune sottomarine), anche se non si escludono apporti fluviali. la presenza di pecten (flabellipecten) flabelliformis (brocchi), associato a comuni esemplari di amphistegina sp. e foraminiferi bentonici tipici di substrati detritici (conti et al., 1983), ne consente l’attribuzione alle “sabbie a flabellipecten” (ambrosetti et al., 1987). sabbie argillose a diretto contatto con il livello precedente, si trovano sabbie molto fini, limoso – argillose (vfs/m) per uno spessore di circa 3 m. il colore è giallo, e le caratteristiche tessiturali sono le stesse descritte per lo spessore sottostante, ad eccezione della granulometria e dell’assenza di intercalazioni ciottolose. sono frequenti, invece, accumuli di gusci frammentati, in una matrice di sabbia molto grossolana (vcs); comuni sono anche locali associazioni di ostreidi, cementati gli uni sugli altri. la documentazione paleontologica appare molto più evidente di prima, e compaiono frequenti microresti vegetali. l’ambiente deposizionale, marino costiero con apporti continentali, e la costanza faunistica, malgrado l’assenza di p. (flabellipecten) flabelliformis, suggeriscono una continuità deposizionale rispetto alle sottostanti sabbie, durante un trend regressivo. pertanto, questi depositi sono riferiti alle “sabbie a flabellipecten”. aarrggiillllee ee ssaabbbbiiee ddeell cchhiiaannii –– tteevveerree argille tra il livello precedente ed i corpi ghiaiosi visibili nella parete di cava sono presenti ~ 5 m di argille limose (m), grigiastre, prive di strutture macroscopiche, ma contenenti sia un’abbondante fauna marina che numerosi microresti vegetali. sono soprattutto questi ultimi caratteri, come verrà meglio esposto nel paragrafo successivo, che ci permettono di attribuirle ad un ambiente francamente marino, ma con apporti continentali di carattere distale. da segnalare la presenza di macrocristalli di pirosseno, non rielaborati né frammentati. ddeeppoossiittii ddii ccoonnooiiddee affiorano come parete di cava, sono separati dalle fig. 2 porzione superiore dell’affioramento del caio. la parete di cava misura 30 m in larghezza e 6 m in altezza, sviluppandosi in direzione n-s (nord a sinistra nella foto). la continuità della parete è interrotta da due piani di taglio con componente inversa, immergenti circa verso nw; il rigetto apparente è di circa 50 cm. sono visibili corpi ghiaiosi e sabbiosi con caratteristiche differenti, complessivamente interpretati come depositi di conoide alluvionale. gmc = ghiaia non organizzata; gp = ghiaia a stratificazione incrociata; sh = sabbia argillosa a laminazione piano parallela; sp = sabbia a laminazione incrociata. upper portion of the caio outcrop. the quarry front is 30 m width and 6 m high, and oriented n-s (north on the left in the photo). the front continuity is broken off by two reverse – fault planes, dipping nw, for a total dislocation of 50 cm. are clearly visible several gravel and sand bodies, with different characters, interpreted as alluvial fan deposits. gmc = disorganized gravel; gp = planar cross – stratified gravel; sh = laminated claiely – sand; sp = planar cross – laminate sand. 244 sottostanti argille da un chiaro contatto erosivo, parzialmente visibile a livello del piano di escavazione, e sono costituiti da corpi con caratteristiche diverse. alternanze ciottoli sabbia la porzione basale della parete di cava (fig. 4) è caratterizzata dall’alternanza di corpi ghiaiosi, abbastanza organizzati, e sabbie a laminazione incrociata. entrambi mostrano geometrie lenticolari, tanto da interdigitarsi reciprocamente. i corpi ghiaiosi, clast – supported, hanno geometria lenticolare e sono abbastanza ben organizzati. i ciottoli, di forma piatta o allungata, da sub – arrotondati a molto arrotondati (arrotondamento da 0,5 a 0,9), hanno dimensioni max di 12 cm, con media intorno ai 5 cm: rientrano pertanto nella classe dei vcp. i clasti sono in netta prevalenza di natura carbonatica (micrifig. 3 successione stratigrafica del caio (parte inferiore). 1 = argilla; 2 = sabbia argillosa; 3 = sabbia; 4 = sabbia con ciottoli; 5 = ghiaia matrice – sostenuta; 6 = livelli cementati; 7 = gasteropodi marini; 8 = glycimeris sp; 9 = flabellipecten flabelliformis; 10 = chlamys spp; 11 = amusium sp; 12 = ostrea spp; 13 = cerastoderma edule; 14 = anadara spp; 15 = dentalium spp; 16 = briozoi; 17 = coralli; 18 = serpulidi; 19 = radioli di echinidi; 20 = burrows di crostacei; 21 = chele di crostacei; 22 = denti di pesci; 23 = frustoli vegetali; 24 = foraminiferi planctonici; 25 = miche; 26 = pirosseni. caio stratigraphic section (lower portion). 1 = clay; 2 = claiely sand; 3 = sand; 4 = gravelly sand; 5 = matrix – supported gravels; 6 = cemented levels; 7 = marine gastropods; 8 = glycimeris sp; 9 = flabellipecten flabelliformis; 10 = chlamys spp; 11 = amusium sp; 12 = ostrea spp; 13 = cerastoderma edule; 14 = anadara spp; 15 = dentalium spp; 16 = briozoa; 17 = corals; 18 = serpulids; 19 = echinoidal radioles; 20 = crustacean (burrows); 21 = crustacean (pincers); 22 = fish teeths; 23 = frustoles; 24 = planctonic foraminifers; 25 = micas; 26 = pyroxenes. r. bizzarri et al. 245 fig. 4 successione stratigrafica del caio (parte superiore). 1 = argilla; 2 = sabbia; 3 = sabbia con ciottoli; 4 = ghiaia clasto – sostenuta; 5 = ghiaia matrice – sostenuta; 6 = livello pedogenizzato non organizzato; 7 = pirosseni; 8 = miche; 9 = pomici; 10 = scorie; 11 = gasteropodi dulcicoli; 12 = natica sp; 13 = unio sp. caio stratigraphic section (upper portion). 1 = clay; 2 = sand; 3 = gravelly sand; 4 = clast – supported gravel; 5 = matrix – supported gravel; 6 = not organized pedogenetic level; 7 = pyroxenes; 8 = micas; 9 = pumices; 10 = scoriae; 11 = freshwater gastropodes; 12 = natica sp; 13 = unio sp. ti e calcareniti della scaglia s.l., calcareniti della marnoso arenacea), ma sono presenti anche areniti, provenienti da formazioni mioceniche della serie umbra o toscana, quarzoareniti di provenienza non chiara (simili ad “anageniti minute” del verrucano toscano) e calcareniti provenienti da corpi parzialmente cementati di età pliocenica (livello ad amphistegina sensu conti et al., 1983). i ciottoli appaiono di colore rosso e/o ocra per la presenza di una patina di ossidi, e sono associati ad una matrice di vcs/g, in cui sono abbondanti macrol’affioramento del caio ... 246 cristalli di pirosseno e proietti piroclastici della taglia dei lapilli. i ciottoli appaiono chiaramente isorientati, disposti con l’asse aa ortogonale al fronte della cava ed il piano aa-bb immergente verso monte, secondo un’embriciatura da corrente, del tipo aa((tt)) bb((ii)). sembra possibile definirli come facies gm (miall, 1982). ai ciottoli si alternano lenti di sabbia ciottolosa, molto grossolana fino a passare ai granuli (vcs/g), a sorting medio – alto (σ = 0,80 – 1,40 ϕ); i singoli elementi, da subarrotondati ad angolosi (arrotondamento da 0,20 a 0,40), sia ad alta che a bassa sfericità, sono in prevalenza frammenti litici di composizione carbonatica, associati a cristalli di quarzo, feldspato e calcite, con frazioni subordinate di pirosseni ad habitus prismatico, di colore verde scuro o nero. sono molto rare le pomici, mentre nella taglia dei granuli sono comuni frammenti di selce. le lenti sabbiose mostrano, localmente, più o meno evidenti laminazioni incrociate a set tabulari, tanto da poterle definire come facies sp (miall, 1982). le alternanze tra facies gm e sp sono interpretate come depositi da sheetflood (blair & mcpherson, 1994). argille sabbiose al tetto dell’alternanza ghiaie – sabbie è presente un livello costituito da argilla limoso – sabbiosa (m/vfs), che può essere designato come facies sh (miall, 1982). si sviluppa per uno spessore massimo di 30 cm ed appare discontinuo. il colore è prevalentemente grigio – verde, ma piccole variazioni cromatiche mettono in evidenza una laminazione ondulata parallela; anche la base del livello appare ondulata. la frazione più grossolana ha rivelato, all’esame microscopico, la prevalenza di frammenti litici a composizione carbonatica, ad alto sorting, elevata sfericità e di forma prevalentemente subarrotondata; questi sono accompagnati da macrocristalli di pirosseno, lamelle di mica e rare pomici. assente la malacofauna, la documentazione micropaleontologica è costituita da qualche ammonia e rari foraminiferi planctonici rimaneggiati. livelli ghiaiosi non organizzati livelli di ciottoli grossolani (max 30 cm, media 16 cm: fc/mc) sono presenti nella parte centrale della parete di cava. mostrano tessitura matrix – supported e sono privi di un’evidente organizzazione, se si esclude la presenza, localmente, di embriciature da flusso gravitativo, di tipo aa((pp)) aa((ii)): sono stati designati come facies gmc (orton, 1988). tra i ciottoli, prevalgono i litotipi carbonatici, associati ad areniti e a litoclasti argillosi. la forma varia con la litologia, ma i ciottoli appaiono in prevalenza ben arrotondati (arrotondamento 0,8 – 0,9). la matrice sabbiosa è molto grossolana (vcs/g), a sorting medio – alto (σ = 0,80 – 1,40 ϕ), arrotondamento da 0,20 a 0,40, e costituita da prevalenti elementi piroclastici (macrocristalli di pirosseno e pomici), con abbondante selce nella taglia dei granuli. si tratta di depositi legati all’azione di un processo di tipo gravitativo, presumibilmente un debris flow non coesivo, o grain flow (nemec & steel, 1984). ciottoli a stratificazione incrociata sempre nella porzione intermedia della parete di cava, si rinvengono due livelli ghiaiosi a stratificazione incrociata, clast – supported, a base erosiva, designati come facies gp (miall, 1982). la media dei ciottoli è intorno a 5 cm, con i clasti più grandi che arrivano a 10 cm (vcp); i litotipi mostrano la stessa associazione descritta in precedenza, sempre con dominanza degli elementi carbonatici. tutti i ciottoli presentano una patina di ossidazione superficiale, che penetra all’interno per alcuni mm, dando al livello un colore bruno – nerastro. la presenza di tale forma di alterazione lascia supporre periodi di esposizione subaerea. la matrice è costituita da sabbia molto grossolana/granuli (vcs/g) ad alto sorting (σ = 0,35 – 0,50 ϕ) ed arrotondamento da 0,20 a 0,40, composta in parti uguali da frammenti litici, pirosseni ad habitus prismatico e pomici. la matrice evidenzia la stratificazione incrociata a set tabulari delle ghiaie, mettendo in luce variazioni nell’inclinazione. si tratta in definitiva del riempimento multi – storey di canali, non molto profondi, dove l’azione di una corrente canalizzata, con buona competenza, si alternava a momenti di emersione del canale. la costruzione dei corpi ghiaiosi (“barre”) avveniva secondo il modello dei gravel sheets (hein & walker, 1977). all’interno del livello superiore si rinvengono frequenti gasteropodi, di dimensioni massime di 1 – 2 cm, ben conservati, sia dulcicoli che marini, accompagnati da individui interi e frammenti di lamellibranchi (unio sp.). sabbie a laminazione incrociata sabbie a gradazione diretta, con granulometria decrescente da media (ms) a fine (fs), identificabili come facies sp (miall, 1982), sono presenti nella parte alta della successione. il livello, di colore grigio e spessore variabile da 10 a 30 cm, con una notevole presenza di mica e pirosseni, mostra una laminazione incrociata a set tabulari ma con verso opposto. una simile situazione, di età diversa, ma con analoghe strutture viene illustrata nella sezione di torre del pagliaccetto (blanch, 1955; malatesta, 1978), dove viene interpretata come risultato di flussi piroclastici. ci sembra che tale interpretazione sedimentologica possa essere applicata anche nel nostro caso, sebbene l’argomento necessiti di ulteriori e più approfonditi studi. tab. 1 scala granulometrica uti l izzata (da blair & mcpherson, 1999, ridis. e semplif.). adopted grain – size scale (from blair & mcpherson, 1999, redrawn). r. bizzarri et al. sabbie argillose la successione è chiusa da circa un metro di sabbie molto fini, limoso argillose (vfs/m), di colore giallo ocra e prive di organizzazione. la presenza di materia organica, di probabile origine vegetale, e di masserelle grigio – verdi di caco3, probabilmente calcinoli, lascia supporre che si tratti di un livello pedogenizzato non organizzato. 44.. aannaalliissii mmaaccrroo ee mmiiccrrooppaalleeoonnttoollooggiiccaa le litologie incoerenti (sabbie, argille sabbiose ed argille) sono state sottoposte a lavaggio con acqua ossigenata. il residuo di lavaggio è stato poi setacciato con maglie a luce netta da 125 µm e 63 µm. sono state osservate tutte le frazioni, da quelle maggiori di 125 µm fino a 63 µm; la componente al di sotto dei 63 µm si è rivelata sempre sterile. il contenuto microfossilifero è stato sottoposto ad un’analisi di tipo semiquantitativo i cui risultati sono riportati nelle tabelle 2 e 3. le litologie argillose sono state inoltre sottoposte ad analisi del contenuto di nannoplancton calcareo, tramite preparazioni di smear slides dal campione integro. l’analisi del nannoplancton calcareo ha rilevato la presenza, nel campione 10, di un’associazione a gephyrocapsa oceanica s.l. kamptner, calcidiscus macintyrei (bukry & bramlette) loeblich & tappan, helicosphaera sellii (bukry & bramlette) jafar & martini, coccolithus pelagicus (wallick) schiller. sia per la presenza del marker (zona a c. macintyrei) associato alla g. oceanica s.l., che per l’assenza di discoasteridi, è possibile riferire il campione 10 al pleistocene inferiore. l’associazione permane con abbondante c. macintyrei anche nel campione 11. come riportato da rio et al. (1997), la scomparsa di c. macintyrei, sincrona a livello mondiale, è riferibile a 1,45 – 1,46 ma. la presenza di tale specie nel nostro campione è ancora cospicua, e pertanto non dovremmo aver raggiunto questa età. la comparsa (fa) di g. oceanica s.l., per la nostra collocazione areale, deve essere considerata come quella del dsdp 132 (m. mediterraneo) e cioè variabile tra 1,56 – 1,62 ma. la concomitante presenza di g. oceanica s.l. e c. macintyrei ci indica un’età ipoteticamente compresa tra 1,62 – 1,46 ma oppure 1,56 – 1,45 ma. 44..11.. ccoommmmeennttii ssuullllaa mmiiccrrooffaauunnaa sulla base delle conoscenze delle faune bentoniche viventi nel mediterraneo e riportate da murray (1991) è possibile individuare caratteristiche associazioni con importanza paleoecologica utilizzabili per una ricostruzione paleoambientale. l’abbondanza del genere ammonia, fin dai campioni basali, indica un ambiente fortemente influenzato da una sedimentazione detritica. la microfauna planctonica fino al campione 8 è assente ad eccezione di rarissime forme di globigerinoides trilobus (reuss) ed orbulina universa d’orbigny rinvenute nel campione 2. le ammonie sono sempre accompagnate, anche come grado di frequenza, dal genere elphidium; a questi due generi si associa, anch’essa abbondante, asterigerinata planorbis (d’orbigny), confermando una situazione di mare poco profondo. la presenza in molti campioni della specie nonion depressulum (walker & jacob), riconosciuto come attualmente vivente nelle associazioni bentoniche che abitano gli ambienti iperalini, accompagnato da ammonia beccari (linnaeus), ci potrebbe fornire indicazioni indirette sulla condizione di salinità di queste acque costiere; la sua presenza infatti ci testimonia che i valori della salinità potevano essere localmente più elevati, forse legati ad una concentrazione di sali causata dall’evaporazione in stagni costieri o pozze d’acqua isolate dal mare da cordoni di sabbie. la variabilità composizionale delle associazioni rinvenute ci indica che nelle immediate vicinanze doveva esistere un collegamento con acque in condizioni più profonde e con valori nella norma marina di salinità. tale evidenza ci viene suggerita dalla abbondanza dei generi elphidium e quinqueloculina, cui si associa la forma erbivora cibicides lobatulus (walker & jacob). lo stile di vita attuale degli elphidium e delle quinqueloculine, che vivono attaccati ai rami delle posidonie, associato con la presenza di c. lobatulus, che vive sulle foglie ed è erbivoro, ci permettono di ipotizzare la presenza di praterie in cui queste forme epifite trovavano un habitat ideale. l’abbondanza inoltre di radioli di echinoidi, di chele di crostacei e di briozoi (spine e rami), abituali abitatori delle praterie a posidonie lungo costa e con fondali prevalentemente sabbiosi, ci confermerebbe un tale quadro paleoecologico. e’ stato rinvenuto anche il genere amphistegina, il cui unico rappresentante attuale, amphistegina madagascariensis d’orbigny (presente nel mediterraneo orientale), vive in habitat di praterie algali associata al genere ammonia. il genere amphistegina si trova abbondante in molti dei campioni analizzati, in cui si rinvengono forme di varia taglia non affetti da abrasione ed interi; questo fatto ci indica che esse vivevano in quell’ambiente, e non vi sono giunte per rielaborazione, probabilmente perché il loro stile di vita era epifita e sfruttavano anch’esse il substrato fornito dalle posidonie. bisogna ricordare a partire dal campione 11 (fig. 5) la presenza di hyalinea balthica (schroeter), tipico “ospite nordico”; tale forma viene riportata in letteratura (azzaroli et al., 1997) come evento caratteristico del pleistocene inferiore (emiliano), anche se la sua comparsa risulta diacrona nelle successioni proposte per la definizione del limite plio – pleistocene. il suo carattere spiccatamente indicativo di variazioni della paleotemperatura delle acque, ci permette di evidenziare un arrivo precoce di masse fredde sul versante paleotirrenico. la specie h. balthica viene attualmente riportata in adriatico come costituente della associazione a bulimina marginata d’orbigny (murray, 1991). concludendo, ci sembra corretto riferire il campione 10 (19 m) al santerniano, mentre il campione 11 (19,5 m) potrebbe essere riferito all’ emiliano basale. sembra inoltre possibile, pur se in via ipotetica, collocare il limite pliocene – pleistocene al metro 18,5 cioè tra i campioni 9 e 10 (fig.3). 44..22.. ccoommmmeennttii ssuullllaa mmaaccrrooffaauunnaa il contenuto macropaleontologico è sintetizzato in tab. 3. nei campioni fino al numero 12 la fauna a molluschi è analoga a quelle riportate nei lavori precedenti (ambrosetti et al., 1987; piccardi, 1994). da segnalare la presenza di pecten (flabellipecten) flabelliformis (brocchi) nel campione 5 e del genere amusium dal campione 8 in poi; nel campione 12 sono presenti due 247l’affioramento del caio ... 248 tab. 2 analisi semiquantitativa della microfauna del caio. (a= abbondante; f= frequente; c= comune; r= raro; p= presente) semiquantitative analysis of the caio section. (a= abundant; f= frequent; c= common; r= rare; p= present) r. bizzarri et al. 249 segue tab. 2 specie del genere chlamys. nei campioni 17 e 18 sono presenti solo molluschi dulcicoli (melanopsis sp., theodoxus sp., planorbis sp., succinea sp., unio sp.), riferibili genericamente ad un pleistocene inferiore (esu d., com. pers.), e qualche esemplare di natica sp. 55.. vvuullccaanniissmmoo eedd aassppeettttii mmiinneerraallooggiiccoo –– ppeettrrooggrraaffiiccii le indagini mineralogico petrografiche eseguite sui materiali appartenenti all’affioramento in esame evidenziano una complessa e articolata composizione geochimico – mineralogico petrografica dei depositi. nel corso dei precedenti paragrafi é stata evidenziata la presenza, dal metro 17,5 fino al tetto della successione, di due distinte famiglie di macrocristalli di pirosseni (con dimensioni fino a 8-10 mm), denominate “pirosseni verdi” e “neri”, le quali vengono sempre rinvenute insieme. le indagini mineralogico cristallochimiche, eseguite in diffrattometria a raggi-x da polveri e in microscopia elettronica a scansione (sem-eds) presso il laboratorio di cristallografia del bayerisches geoinstitut – universitat bayreuth, dimostrano che la famiglia dei “pirosseni verdi” é rappresentata da termini a composizione prevalentemente diopsidica (feo wt% 2%), mentre i “pirosseni neri” rappresentano i termini più augitici (feo wt% 10%). i fillosilicati segnalati (esclusa la frazione argillosa) sono sostanzialmente rappresentati da anniti biotiti e da qualche esemplare di muscovite. la componente feldspatica é rappresentata prevalentemente da k-feldspati (or 70-80). un approfondimento analitico é stato rivolto alle micropomici presenti nei campioni 17 e 18. tali pomici, che si rinvengono peraltro dal metro 25 al metro 28, hanno forma spigolosa, con dimensioni che raramente superano il millimetro, e mostrano solo minime evidenze di rielaborazione in ambiente alluvionale, indice di un trasporto limitato. le indagini effettuate in microscopia elettronica a scansione mostrano dei materiali estremamente variabili in termini di porosità, tessitura, composizione mineralogica. la figura 6a mostra un’immagine sem di una pomice relativa al campione 18. e’ evidente la presenza di due distinti litotipi. la parte superiore (frazione con più alta presenza di fasi cristalline) é caratterizzata dalla presenza di k-feldspati, na-plagioclasi, clinopirosseni augitici, alcuni ossidi (spinelli) e da una pasta di fondo vetrosa. la parte inferiore della pomice mostra la presenza di na-plagioclasi e di qualche cristallo di calcite, immersi in pasta di fondo vetrosa. dal punto di vista minerogenetico, é presumibile che il forte arricchimento in sodio dei plagioclasi (ab 70-85) sia un fenomeno secondario e che i cristalli di calcite rappresentino dei termini estranei all’assemblaggio mineralogico della roccia originaria (es. frammenti strappati da un eventuale condotto vulcanico, materiali saldati al frammento pomiceo all’impatto con il terreno, etc.). al campione 18 appartiene la pomice rappresentata nella figura 6b. in questo caso sono evidenti una diversa porosità ed una differente tessitura rispetto alla pomice rappresentata in figura 6a. la frazione cristallina é rappresentata da clinopirosseni (augitici) idiomorfi tozzi e aciculari immersi in una pasta di fondo vetrosa. sono abbondanti minerali secondari, come ad esempio nae ca-zeoliti. la figura 6c rappresenta l’immagine sem di una pomice appartenente al campione 17. sono evidenti alcuni fenocristalli di ortopirosseno enstatitico (analisi media: mgo 47.9%, feo 8.9%, cao 0.3%, sio2 42.9%), di clinopirosseno augitico e di na-plagioclasio. anche in questo caso sono presenti minerali zeolitici. i tre esempi di pomici appena descritti evidenziano un’articolata composizione mineralogico petrografica l’affioramento del caio ... dei materiali in esame. tale disomogeneità non consente di effettuare risolutivi confronti mineralogico petrografici con i litotipi delle province comagmatiche limitrofe all’area in esame (hks provincia comagmatica romana; ks m.ti vulsini, roccamonfina, ventotene; ulud distretto ultra alcalino umbro-laziale; provincia comagmatica toscana; poli, 1985; conticell i & peccerillo 1992; stoppa & lavecchia, 1992; peccerillo, 1998; 1999) allo scopo di stabilire eventuali relazioni e affinità. l’eccessiva alterazione dei vetri che costituiscono la pasta di fondo delle pomici, dimostrata dalla presenza di minerali zeolitici, comporta una diversissima composizione chimica evidente anche esaminando punti a distanza di pochi micrometri. la limitata quantità di campione a disposizione per ciascun tipo di pomice (ciascun individuo ha dimensioni inferiori al millimetro) non ha permesso di effettuare indagini, con un fondato significato statistico, sulla composizione chimica globale dei litotipi al fine di poter effettuare una classificazione petrologica. tuttavia, la presenza di ortopirosseni, riscontrata in diversi campioni pomicei, sembra suggerire un’affinità geochimica con la provincia toscana piuttosto che con le altre province magmatiche succitate, in cui gli ortopirosseni non sono mai stati segnalati. un particolare ritrovamento nel corso del rilevamento geologico ha suggerito la possibilità di un centro eruttivo, probabilmente di modeste dimensioni, localizzato in prossimità dell’area in esame. particolari campioni di materiale vetroso sono stati rinvenuti nel campione 17b, prelevato al metro 26,5. le indagini in diffrattometria a raggi-x da polveri rivelano l’assoluto stato amorfo di questa sostanza. l’osservazione sem-eds 250 tab. 3 distribuzione della macrofauna del caio. (a= abbondante; f= frequente; c= comune; r= raro; p= presente) macrofauna distribution of caio section. (a= abundant; f= frequent; c= common; r= rare; p= present) r. bizzarri et al. mostra una tipica morfologia da campioni vetrosi (fig. 6d), caratterizzata da frattura concoide/vetrosa. l’analisi chimica semiquantitativa (sem-eds) riporta la seguente composizione media: 28.4% al2o3, 59.4% sio2, 1.6% cao, 0.6% tio2, 8.0% feo, 1.9% mgo. l’ipotesi maturata riguardo la genesi di questi materiali é la fusione di argille (o comunque di litotipi molto ricchi in alluminio) da parte di un fuso magmatico: l’associazione micropaleontologica (tab. 2) rinvenuta nel medesimo campione 17b sembra suffragare tale interpretazione. questo comporterebbe la presenza in loco di un evento effusivo, se pur di modeste dimensioni (es. dicco). il rilevamento geologico dell’area non ha ancora evidenziato la presenza di tale evento e gli studi sono ancora in corso. 66.. ddiissccuussssiioonnee sulla base delle associazioni microfaunistiche, malacologiche e dei caratteri sedimentologici è possibile affermare che la porzione basale del caio (0 23m) comprende sia la parte superiore dell’unità delle “sabbie a flabellipecten” (ambrosetti et al., 1987) che la porzione basale dell’unità “argille e sabbie del chiani tevere” (ambrosetti et al., 1987). l’analisi micropaleontologica ha inoltre permesso di identificare, all’interno delle “argille e sabbie del chiani – tevere”, sedimenti riferibili al pliocene superiore pleistocene inferiore (zona a g. inflata) per la presenza del marker zonale (fig. 5). la successione evolve da un ambiente marino costiero (shoreface superiore) ad un ambiente salmastro durante il pliocene superiore, per poi passare ad un ambiente francamente marino databile al pleistocene inferiore. ad ulteriore conferma dell’età pleistocenica si riscontra la presenza di h. balthica “ospite nordico” (fig. 5). il limite plio – pleistocene è stato posto all’interno delle argille, mentre appare probabile la presenza di una lacuna, riconducibile alla fase erosiva nota in letteratura 251 fig. 5 a) globorotalia inflata (d’orbigny), lato ombelicale, campione 10; b) globorotalia inflata (d’orbigny), lato ombelicale, individuo con margine aperturale rotto, campione12; c) globigerina decoraperta takayanagi & saito, visione laterale, campione 10; d,o,p) bulimina marginata d’orbigny, campioni 10, 11, 16; e,h) planulina ariminensis d’orbigny, lato ombelicale, campione 16; f,g) hyalinea balthica (schroeter) lato ombelicale, campioni 11, 17b; i) uvigerina peregrina cushman, campione 17; l) bulimina costata d’orbigny, campione 11; m) uvigerina mediterranea hofker, campione17b; n) bolivina sp., campione 13; q) anomalinoides sp., campione 2; r) uvigerina pigmea d’orbigny, campione 17b. a) globorotalia inflata (d’orbigny), umbilical view, sample 10; b) globorotalia inflata (d’orbigny), umbilical view, specimen with broken apertural border, sample 12; c) globigerina decoraperta takayanagi & saito, side view, sample 10; d,o,p) bulimina marginata d’orbigny, samples 10, 11, 16; e,h) planulina ariminensis d’orbigny, umbilical view, sample 16; f,g) hyalinea balthica (schroeter) umbilical view, samples 11, 17b; i) uvigerina peregrina cushman, sample 17; l) bulimina costata d’orbigny, sample 11; m) uvigerina mediterranea hofker, sample 17b; n) bolivina sp., sample 13; q) anomalinoides sp., sample 2; r) uvigerina pigmea d’orbigny, sample 17b. l’affioramento del caio ... come “acquatraversa” (ambrosetti & bonadonna, 1967), tra le sabbie argillose e le argille. appare qui opportuna una breve riflessione sul significato di tale termine. ambrosetti et al. (1987) suggeriscono la presenza di una lacuna, estesa dalla parte finale della zona g. crassaformis fin dentro alla zona g. cariacoensis comprendente pertanto l’intera estensione della zona g. inflata. tale hiatus di natura almeno in parte erosiva sarebbe legato principalmente all’attività tettonica distensiva del pliocene medio superiore (ambrosetti et al., 1977), ma sembrerebbe coincidere (azzaroli et al., 1997) con un importante deterioramento climatico che accompagna la caduta del livello marino. la risalita del livello marino nel pleistocene inferiore sembra essere conseguenza di una nuova fase tettonica estensionale, con faglie ad andamento antiappenninico. i dati in nostro possesso sembrano collocare almeno parte dell’affioramento del caio all’interno dell’originaria estensione della suddetta lacuna stratigrafica (ambrosetti et al., 1987). da un lato, si assiste ad una transizione graduale da un ambiente marino costiero ad un salmastro con malacofaune che, malgrado la scomparsa del flabellipecten, non mostrano apprezzabili variazioni e sono le stesse citate in letteratura (piccardi, 1994); una simile tendenza ben si sposa con il trend regressivo del pliocene medio. d’altro canto nelle sovrastanti argille marine, riferibili ad una successiva fase di high – stand, è già presente g. inflata prima della comparsa di forme francamente pleistoceniche (g. oceanica, h. balthica). dal m 23 al m 29 i corpi ghiaiosi, legati ad un contesto deposizionale di conoide alluvionale, testimoniano la fine della tendenza trasgressiva e l’instaurarsi di locali condizioni continentali. le caratteristiche dei depositi ghiaiosi indicano chiaramente l’alternanza di momenti di intenso dilavamento, in cui sono attivi sia processi gravitativi che processi trattivi, canalizzati e non, e momenti di stasi, durante i quali parte dei materiali deposti subisce un’esposizione subaerea, che ne determina ossidazione superficiale. si può ipotizzare un paleoambiente di tipo caldo – umido o temperato – umido, caratterizzato 252 fig. 6 immagini sem (in elettroni retrodiffusi) dei campioni con materiale piroclastico: a) pomice proveniente dal campione 18 (cc: calcite, cpx: clinopirosseno, k-feld: k-feldspato, na-plag: na-plagioclasio); b) pomice proveniente dal campione 18. in questo particolare sono evidenti clinopirosseni idiomorfi tozzi e aciculari nonché minerali zeolitici, dall’aspetto fibroso aciculare, localizzati particolarmente nei vacuoli ; c) pomice proveniente dal campione 17. sono evidenti dei fenocristalli di ortopirosseno enstatitico, di clinopirosseno augitico e di na-plagioclasio, questi ultimi fortemente alterati e associati a minerali zeolitici; d) campione di materiale vetroso rinvenuto nel campione 17b. sem-eds image from samples with volcanoclastic material: a) a pumice from sample 18 (cc: calcite, cpx: clinopyroxene, k-feld: kfeldspar, na-plag: na-plagioclase); b) a pumice from sample 18. are evident hidiomorph acicular and squat clynopyroxenes, fibratus acicular zeolites into the vacuolar porosity; c) a pumice from sample 17; are evident phenocrystals of enstatitic ortopyroxenes, augitic clynopyroxenes and of na-plagioclases (deeply alterated and in assemblage with zeolites); d) glass material from sample 17b. r. bizzarri et al. da una marcata stagionalità, con momenti di intense precipitazioni, motore dei processi di dilavamento e delle “piene” fluviali, seguiti da periodi di “magra” sufficientemente lunghi da permettere l’esposizione subaerea di parte dei depositi. l’età di questi corpi di conoide resta un problema aperto. e’ però possibile proporre alcune considerazioni, mutuate dai dati fin qui acquisiti, che ne suggeriscono un’attribuzione al pleistocene inferiore (emiliano inferiore), sebbene non possa essere del tutto esclusa un’età ancora più recente. 1) tra le microfaune rimaneggiate sono presenti solo forme del pliocene medio – pleistocene inferiore, accompagnate da h. balthica. 2) la petrologia dei clasti, a prescindere dalle litologie legate allo smantellamento del substrato pre-pliocenico, evidenzia la rielaborazione delle litofacies marine sottostanti, principalmente biocalcareniti del pliocene medio – superiore (livello ad amphistegina sensu conti et al., 1983). 3) le piroclastiti, rinvenute dal m 17.5 al m 29, contengono gli stessi pirosseni non alterati, con habitus prismatico pressoché perfetto, i quali non mostrano evidenze di abrasione da trasporto. la costanza dei caratteri per cristalli contenuti all’interno di corpi deposti in ambienti di sedimentazione profondamente diversi suggerisce che i due paleoambienti siano pressoché coevi. 4) sulla base dei dati mineralogici e petrografici preliminari, si possono fare alcune considerazioni generali sull’affinità dei prodotti vulcanici rispetto alle province comagmatiche limitrofe (hks provincia comagmatica romana; ks monti vulsini, roccamonfina, ventotene; provincia magmatica toscana; ulud distretto ultra alcalino umbro-laziale). malgrado le caratteristiche del materiale analizzato non permettano determinazioni radiometriche, la presenza di cristalli di ortopirosseno, mai segnalati nelle altre province magmatiche, suggerisce un’affinità toscana. gli eventi vulcanici legati a tale provincia comagmatica, se si esclude l’attività recente del m. amiata, hanno un’età anteriore rispetto al vulcanismo cimino (1,35 – 0,95 ma) e al complesso del paleo – bolsena (0,576 – 0,505 ma). l’aspetto stesso delle piroclastiti, che mostrano minime evidenze di rielaborazione in ambiente alluvionale, testimonia un trasporto limitato e probabilmente una contemporaneità tra messa in posto del conoide e almeno parte dell’attività eruttiva. 5) nella parte finale dell’affioramento è stata rinvenuta un’associazione a molluschi, costituita da poche forme sia marine che dulcicole, queste ultime riferibili al pleistocene inferiore (esu, com. pers.). le vulcaniti presenti nella sezione del caio potrebbero essere assimilabili a quelle riportate in letteratura da ambrosetti et al. (1968) e bigazzi et al. (1994), come vulcaniti plio-pleistoceniche del lazio e della toscana. sembra che non sia da escludere la possibilità di correlare i livelli vulcanoclastici del caio con uno dei livelli già noti, da oltre 30 anni, e segnalati da uno degli scriventi (p.a.) nella successione di valle ricca (lazio); d’altro canto, appare plausibile la correlabilità con un centro di emissione ad affinità tirrenica non noto, ma supposto anche da altri autori (bigazzi et al., 1994). la presenza di materiale vetroso, probabilmente dovuto alla fusione di minerali argillosi e rinvenuto nel campione 17b, non esclude che la frazione piroclastica presente possa provenire da un piccolo centro vulcanico situato nelle vicinanze e non ancora evidenziato dal rilevamento geologico. diversi sono stati gli eventi vulcanici di modeste dimensioni (es. dicchi) segnalati in umbria e lazio nel corso degli ultimi anni (stoppa & cundari, 1995; 1998; stoppa et al., 1997), ma si tratta in tutti i casi di eventi più recenti. un evento continentale, analogo a quello da noi riscontrato, intercalato alle “argille e sabbie del chiani –tevere”, è stato descritto da girotti & piccardi (1994) immediatamente a sud dell’area in esame (camartana). tale evento viene riferito dagli autori al santerniano (fase erosiva “aulla”), più in base ai dati conosciuti riguardo all’età delle “argille e sabbie del chiani –tevere” che non per la presenza di riferimenti temporali certi. con i dati attualmente in nostro possesso, è solo possibile ipotizzare un’analogo contesto deposizionale. l’argomento merita un successivo approfondimento, per determinare se si tratti dello stesso evento oppure di due eventi distinti, di ordine minore, all’interno di un evento di ordine maggiore. in conclusione, alcune significative novità sembrano emergere dai dati fin qui raccolti: 1) il rinvenimento di h. balthica all’interno di depositi riferibili alle “argille e sabbie del chiani –tevere”, evento finora mai riscontrato, se da un lato sembra permettere l’estensione temporale di tale unità fin dentro l’emiliano, dall’altro mette in discussione la proposta attribuzione al santerniano della definitiva regressione marina di questa porzione di costa paleotirrenica (ambrosetti et al., 1987). 2) il ritrovamento di piroclastiti a probabile affinità toscana suggerisce l’esistenza di un evento vulcanico non noto, riferibile al pleistocene inferiore, di età antecedente sia all’attività cimina più antica, che a quella del “paleo bolsena”. 3) la presenza di depositi francamente continentali, di età confrontabile con quella delle sottostanti argille marine, se da un lato complica la ricostruzione del quadro paleogeografico dell’area, dall’altro evidenzia l’esistenza di più eventi di fluttuazione del l.m. durante il pleistocene inferiore (santerniano – emiliano). la parte superiore dell’affioramento del caio, pur evidenziando una situazione paleoambientale locale, testimonia quindi l’estrema variabilità laterale dei depositi del pleistocene inferiore, riferibili o eteropici alle “argille e sabbie del chiani – tevere”. infatti, è ipotizzabile un’articolazione delle morfologie costiere, in parte ereditate ma senz’altro esasperate dall’intensa tettonica che caratterizza il passaggio pliocene – pleistocene: questa fase, con assi strutturali ad andamento antiappenninico, disloca i depositi del pliocene, che vengono in parte rielaborati, e determina una marcata eteropia di facies. in questo contesto, in cui le stesse argille documentano ambienti marini di profondità diverse, complessivamente più distali andando da est ad ovest, si impostavano corpi di conoide, come quello del caio, che drenavano verso sw o nw, rimaneggiando le differenti facies presenti nel bacino in cui confluivano. nell’affioramento descritto mancano del tutto depositi di barra di foce e di piana costiera, mentre sono presenti corpi di ambiente francamente continentale, collegabili alla porzione medio – prossimale del conoide, direttamente a contatto con depositi marini, che potrebbero forse costituire la porzione più distale del prodelta. una simile situazione di affioramento, in cui non tutti i depositi sono contemporaneamente conservati, è stata descritta ad esempio nel fan – delta di loro – ciuffenna, in valdarno (billi et al., 1991). 253l’affioramento del caio ... non è da escludere che nell’area esistano situazioni analoghe a quella del caio, che potranno essere evidenziate da un dettagliato rilevamento. rriinnggrraazziiaammeennttii gli autori intendono qui ringraziare la prof. daniela esu ed il prof. francesco paolo bonadonna per la loro collaborazione, nonché il dott. luca costantini, che ci ha segnalato l’affioramento. vogliamo inoltre ringraziare il prof. roberto colacicchi ed il prof. leonsevero passeri per la loro disponibilità ad interessanti e costruttive discussioni. llaavvoorrii cciittaattii aa.vv. (1982) – bacino del fiume paglia (umbria – toscana): studi strutturali, idrogeologici e geochimici. relazione finale sul tema di ricerca: “ studi geologici, idrogeologici e geofisici finalizzati alla ricerca di fluidi caldi nel sottosuolo”. cnr – progetto finalizzato energetica, rf 1166. ambrosetti p., azzaroli a., bonadonna f.p. & follieri m. (1972) – a scheme of pleistocene chronology for the tyrrhenian side of central italy boll. soc. geol. ital., 9911, 169184. ambrosetti p. & bonadonna f.p. (1967) – revisione dei dati sul plio pleistocene di roma atti acc. gioenia sci. nat. catania, 1188, 33-72. ambrosetti p., bonadonna f.p., ferrara g., fornasieri m., tolomeo l. & tongiorgi e. (1968) – segnalazione di un livello vulcanico nelle argille plioceniche della sabina (lazio settentrionale) boll. soc. geol. ital., 8877, 333340. ambrosetti p., carboni m.g., conti m.a., costantini a., esu d., gandin a., girotti o., lazzarotto a., mazzanti r., nicosia u., parisi g. & sandrelli f. (1978a) evoluzione paleogeografica e tettonica nei bacini tosco umbro laziali nel pliocene e nel pleistocene inferiore mem. soc. geol. ital., 1199, 573-580. ambrosetti p., carboni m.g., conti m.a., esu d., girotti o., la monica g.b., landini b. & parisi g. (1987) il pliocene ed il pleistocene inferiore del bacino del fiume tevere nell’umbria meridionale geogr. fis. dinam. quat., 1100, 10 – 33. ambrosetti p., cattuto c., conti m.a., nicosia u. & parisi g. (1978b) – dati preliminari sulla neotettonica del foglio 130 (orvieto) contributi preliminari alla realizzazione della carta neotettonica d’italia c.n.r. progetto finalizzato geodinamica, 115555, 391-397. ambrosetti p., conti m.a., parisi g., kotsakis t. & nicosia u. (1977) neotettonica e cicli sedimentari plio-pleistocenici nei dintorni di città della pieve (umbria) boll. soc. geol. ital., 9966, 605 – 635. azzaroli a., colalongo m.l., nakagawa h., pasini g., rio d., ruggieri g., sartoni s. & sprovieri r. (1997) – the pliocene – pleistocene boundary in italy – in “the pleistocene boundary and the beginning of the quaternary”, van couvering j.a. (ed.). cambridge university press, new york, 141 – 155. bigazzi g., bonadonna f.p., cioni r., leone g., sbrana a. & zanchetta g. (1994) – nuovi dati geochimici, petrografici e geocronologici su alcune cineriti plio pleistoceniche del lazio e della toscana mem. descr. carta geol. d’it., 4499, 135-150. billi p., magi m. & sagri m. (1991) pleistocene lacustrine fan delta deposits of the valdarno basin – italy jour. sedim. petr., 6611, 280 – 290. bizzarri r. (2001) – facies costiere plioceniche nell’area di corbara (orvieto) tesi di laurea inedita, università degli studi di perugia, 169 pp. blair t.c. & mcpherson j.g. (1994) alluvial fan and their natural distinction from rivers based on morphology, hydraulic processes, sedimentary processes, and facies assemblages jour. sedim. petr., 6644, 450 – 489. blair t.c. & mcpherson j.g. (1999) grain size and textural classification of coarse sedimentary particles jour. sedim. res., 6699, 6-19. blanch a.c. (1955) – giacimento paleolitico inferiore di torre in pietra e giacimenti levalloiso – musteriani di palo e di palidoro quaternaria, 22, 305-308. cattuto c., cencetti c. & gregori l. (1988) – il bacino di pornello – frattaguida e l’evoluzione idrografica plio – pleistocenica tra il fiume paglia e il fiume tevere – suppl. geogr. fis. dinam. quat., 11, 161169. cattuto c., conti m.a., nicosia u. & parisi g. (1979) – relazione sulla neotettonica dei fogli 130, 131, 137 e 138 contributi preliminari alla realizzazione della carta neotettonica d’italia c.n.r. progetto finalizzato geodinamica, 225511, 13-28. conti m.a., parisi g. & nicosia u. (1983) un orizzonte ad amphistegina nel pliocene di orvieto e sue implicazioni neotettoniche boll. soc. geol. it., 110022, 113 – 122. conticelli s. & peccerillo a. (1992) petrology and geochemistry of potassic and ultrapotassic volcanism in central italy: petrogenesis and inferences on the evolution of the mantle sources in: peccerillo a., and foley s. (edts), potassic and ultrapotassic magmas and their origin, lithos, 2288, 221-240. funiciello r., parotto m. & praturlon a. (1981) – carta tettonica d’italia. cnr – progetto finalizzato geodinamica, 226699, roma. girotti o. & piccardi e. (1994) – linee di riva del pleistocene inferiore sul versante sinistro della media valle del f. tevere – il quaternario, 77, 525536. hein f.j. & walker r.g. (1977) – bar evolution and development of stratification in the gravelly, braided, kicking horse river, british columbia can. jour. earth scien., 1144, 562 – 570. malatesta a. (1978) – la serie di torre del pagliaccetto e il bacino di torre in pietra quaternaria, 2200, 237-246. miall a.d. (1982) lithofacies types and vertical profile models in braided river deposits: a summary in miall, a.d., ed., fluvial sedimentology. cspg memoir 55, 597 – 604. murray j. (1991) – ecology and palaeoecology of benthic foraminifera. longman, 397 pp. nemec w. & steel r.j. (1984) – alluvial and coastal conglomerates: their significant features and some comments on gravelly mass – flow deposit -.in 254 r. bizzarri et al. koster e.h. & steel r.j., eds., sedimentology of gravels and conglomerates. cspg memoir 1100, 131. orton g.j. (1988) – a spectrum of middle ordovician fan deltas and braidplain deltas, north wales: a consequence of varying fluvial clastic input in nemec w. & steel r.j., eds., fan deltas: sedimentology and tectonic settings: blackie and son, 23-49. peccerillo a. (1998) relationships between ultrapotassic and carbonate-rich volcanic rocks in central italy: petrogenetic implications and geodynamic significance lithos, 4433, 267-279. peccerillo a. (1999) multiple mantle metasomatism in central-southern italy: geochemical effects, timing and geodynamic implications geology, 2277, 315318. piccardi e. (1994) new data on the “argille sabbiose del chianitevere” (northern latiumsouthern umbria, central italy) in “studies on ecology and palaeoecology of benthic communities”, r. matteucci, carboni m.g. & pignatti j.s. (eds.). boll. soc. pal. ital., spec. vol. 22: 213220. poli g. (1985) phase composition in volcanic rocks from south of tuscany magmatic area (central italy): inference of conditions of magma crystallization neues jahr. miner. abh., 115511, 141-167. stoppa f. & cundari a. (1995) a new italian carbonatite occurrence at cupaello (rieti) and its genetic significance – contr. mineral. petrol., 7755, 275-288. stoppa f. & cundari a. (1998) origin and multiple crystallization of the kamafugite carbonatite association: the san venanzo pian di celle occurrence (umbria, italy) min. mag., 6622, 273-289. stoppa f. & lavecchia g. (1992) late pleistocene ultra-alkaline magmatic activity in the umbrialatium region (italy). an overview j. vulcanol. geothermal res., 5522, 277-293. stoppa f., sharygin v. & cundari a. (1997) new mineral data from the kamafugite carbonatite association: the melilitolite from san venanzo, italy mineral petrol., 7788, 251-265. 255 ms. ricevuto il 30 aprile 2003 testo definitivo ricevuto il 7 ottobre 2003 ms. received: april 30, 2003 final text received: october 7, 2003 l’affioramento del caio ... imp.d'ambrogi problemi e potenzialità dell'utilizzo delle ubsu per l'interpretazione e la rappresentazione cartografica dei depositi marini chiara d’ambrogi servizio geologico d’italia dipartimento difesa del suolo apat via curtatone, 3 00185 roma <chiara.dambrogi@apat.it> abstract: c. d'ambrogi, unconformity-bounded stratigraphic units (ubsu) in the marine deposits geological mapping: problems and potentialities. the unconformity-bounded units (ubsu) are formal stratigraphic units defined as “body of rocks bounded above and below by specifically designated, significant and demonstrable discontinuities in the stratigraphic succession, preferably of regional or interregional extent” (salvador, 1994); in the national geological map at the scale 1:50,000 (carg project) these mappable stratigraphic units are recommended particularly for the continental quaternary successions and for the volcanic rocks (apat, 2003); however they are also used for not very deformed marine successions (piedmont tertiary basin and outer front of northern apenninic chain). in the four examined geological sheets the recognition of unconformities pairs the litostratigraphy. nevertheless only in the salsomaggiore terme and parma nord sheets ubsu are used as mappable units. in the cabella ligure sheet depositional units are defined across the entire basin, where the unconformities pass to their correlative conformities; these units are represented in a prototype map enclosed to the geological sheet. the coordination activities carried out for the carg project have produced a new cartographic symbol useful for mapping the unconformities also in undifferentiated litostratigraphic units. parole chiave: unità stratigrafiche a limiti inconformi; stratigrafia fisica; progetto carg; cartografia geologica. keywords: unconformity-bounded units; physical stratigraphy; carg project; geological mapping. il quaternario italian journal of quaternary sciences 21(1a), 2008 47-50 le unità a limiti inconformi (ubsu) sono unità stratigrafiche formali (salvador, 1994) definite come “corpi rocciosi delimitati alla base e alla sommità da significative unconformities”; l’identificazione delle unconformities risulta elemento essenziale per la definizione di tali unità stratigrafiche. nell’ambito del progetto nazionale di cartografia geologica alla scala 1:50.000 (progetto carg) l’utilizzo di tali unità è espressamente raccomandato per il rilevamento e la cartografia delle successioni quaternarie continentali e delle rocce vulcaniche (guida italiana alla classificazione e alla terminologia stratigrafica, 2003); tuttavia ha trovato spazio di applicazione, soprattutto come elemento di sintesi, anche nel caso di successioni di depositi marini debolmente deformati. le attività di coordinamento svolte nell’ambito del progetto carg hanno consentito di evidenziare alcuni aspetti problematici e le potenzialità connessi all’utilizzo delle ubsu, e più in generale all’applicazione di criteri di stratigrafia fisica, nell’ambito della rappresentazione cartografica di successioni di depositi marini. le esperienze maturate da diversi gruppi di lavoro impegnati nella realizzazione di alcuni fogli del progetto carg hanno evidenziato come, a fronte di approcci metodologici simili, si sia arrivati a scelte cartografiche molto diverse. per garantire il massimo dell’uniformità tra fogli si è giunti alla definizione di un nuovo simbolo che consenta di mantenere un elevato livello di informazione sulla presenza di superfici di discontinuità, pur utilizzando un criterio di tipo litostratigrafico. in questa nota si riportano, in carattere corsivo, periodi tratti dalle note illustrative e/o dalle legende dei suddetti fogli con lo scopo di riportare integralmente e sottolineare l’interpretazione e le scelte dei diversi autori. vengono di seguito descritte le scelte, diverse soprattutto in termini cartografici, adottate per alcuni fogli del bacino terziario piemontese (f. 157 trino e f. 196 cabella ligure) e del margine esterno della catena appenninica settentrionale (f. 180 salsomaggiore terme e f. 181 parma nord); tali fogli sono caratterizzati da un approccio metodologico comune, contraddistinto dal riconoscimento e dalla descrizione delle superfici di discontinuità ad affiancare la suddivisione litostratigrafica, ma si differenziano nella scelta delle unità stratigrafiche (litostratigrafiche o a limiti inconformi) cartografate. il foglio 157 trino (servizio geologico d'italia, 2003) presenta una successione paleogenico-neogenica distinta in unità litostratigrafiche, molte delle quali già ampiamente utilizzate e note in letteratura (argille azzurre, sabbie di asti); l'analisi dei caratteri litologici è stata accompagnata dall'individuazione, correlazione e gerarchizzazione delle superfici di discontinuità che separano i corpi rocciosi. tali superfici sono identificate dalla presenza di almeno una delle seguenti caratteristiche: discordanza angolare, disconformità erosionale, brusco salto di facies, indizi di tipo diagenetico, improv48 c. d’ambrogi viso cambiamento nella composizione dei sedimenti. le superfici così individuate hanno portato alla definizione di diverse ubsu che, per scelta degli autori, non sono state rappresentate in carta, ma riportate unicamente nello schema dei rapporti stratigrafici, che rappresenta una sintesi dell'assetto stratigrafico della successione e che costituisce il modello interpretativo dell'evoluzione tettonico-sedimentaria (dela pierre et alii, 2003); esse costituiscono, quindi, delle chiavi di lettura dei rapporti genetici che intercorrono tra le unità litostratigrafiche riconosciute e cartografate nel foglio. anche il foglio 180 salsomaggiore terme (servizio geologico d'italia, in stampa) presenta, per i depositi marini del messiniano superiore-pliocene inferiore p.p., un approccio misto, litostratigrafico e a ubsu; per i depositi marini e paralici del pliocene inferiore p.p.pleistocene inferiore, invece, gli autori hanno scelto esclusivamente il metodo delle ubsu. a differenza del foglio trino, però, le ubsu attribuibili ai depositi marini e marino-paralici mio-pleistocenici assumono, nel foglio salsomaggiore terme, il carattere di unità cartografabili, venendo descritte in legenda e rappresentate nel campo carta. l'applicazione dei criteri della stratigrafia fisica alla successione miocenica (post evaporitica) e pliocenica nell'ambito del progetto carg è un approccio di tipo sperimentale, (calabrese & di dio, in stampa). occorre sottolineare che la scelta degli autori di adottare i principi della stratigrafia fisica è legata alla disponibilità, in questo settore dell'appennino, di dati di sottosuolo (fig. 1a) a integrare quelli di superficie, nonché alla buona conoscenza dell'architettura deposizionale a scala regionale; le principali superfici di discontinuità riconosciute sono poste come l imiti di supersintemi (fig. 1b), mentre le discontinuità minori sono utilizzate per definire sintemi e subsintemi. per evitare che tale criterio metodologico creasse problemi di collegamento e di nomenclatura delle unità, soprattutto con i fogli confinanti, è stato deciso di cartografare, per la porzione messiniano-pliocenica della successione, le unità litostratigrafiche note in letteratura (formazione a colombacci, formazione di vernasca, argille di lugagnano), e già adottate anche nei fogli limitrofi, piuttosto che unità a limiti inconformi, che compaiono solo come contenitori (sintema del t. ongina in fig. 1c). le esperienze maturate nell'ambito dei fogli trino e salsomaggiore terme sembrerebbero evidenziare la possibilità di un utilizzo delle ubsu anche per la rappresentazione cartografica di depositi marini, con l'indubbio vantaggio di fornire chiavi di lettura di sintesi dell'evoluzione dei bacini. tuttavia la scelta di cartografare le sole ubsu pone dei problemi quando si passa da zone in cui le superfici di discontinuità sono presenti e riconosciute a zone in cui tali superfici passano a quelle di continuità ad esse correlabili, come ben evidenziato dagli autori del foglio 181 parma nord (servizio geologico d'italia, in stampa). tale foglio è stato realizzato secondo lo stesso approccio metodologico del confinante foglio salsomaggiore terme, tuttavia, in legenda, nella descrizione del supersintema quaternario marino (pliocene sup.-pleistocene inf.), si evidenzia che nella parte settentrionale del foglio (nel sottosuolo) la superficie di discontinuità basale passa alla corrispondente superficie di continuità e, pertanto, non si potrà parlare più, per definizione, di supersintema quaternario marino, ma di sequenza deposizionale del quaternario marino. tale problema si estende a tutte le unità in cui viene suddiviso il supersintema; esse andranno considerate fig. 1 a) linea sismica e b) sezione geologica del f. 180 salsomaggiore terme (da apat, in stampa; parziali e modificate); sono state evidenziate le superfici di discontinuità che delimitano i supersintemi. c) schema delle ubsu adottate nel f. 180; il sintema del t. ongina è suddiviso in unità litostratigrafiche per garantire maggiore uniformità con i fogli limitrofi. a) seismic line and b) geological cross-section of the sheet 180 salsomaggiore terme (modified, servizio geologico d'italia, in print); the thick lines are the unconformity surfaces that define the supersynthems. c) ubsu scheme adopted for the sheet 180; to facilitate the correlation with the adjacent sheets the t. ongina synthem has been subdivided into lithostratigraphic units. sequenze deposizionali (sensu mitchum et alii, 1977) di rango gerarchico corrispondente. il passaggio concettuale da unità a limiti inconformi a sequenze deposizionali è sottolineato nella guida italiana alla classificazione e alla terminologia stratigrafica (2003) dove si ricorda che le ubsu sono definite sulla base delle superfici di discontinuità che le delimitano, mentre le seconde sono unità delimitate alla base e al tetto da discontinuità o dalle corrispondenti superfici di continuità. la possibilità di utilizzo delle stratigrafia fisica come tecnica utile a integrare il tradizionale metodo litostratigrafico è prevista nella guida al rilevamento della carta geologica d'italia 1:50.000 quaderni, vol. 1 (sgn, 1992): “data per scontata l'oggettività delle tradizionali unità litostratigrafiche, queste ultime devono essere arricchite di informazioni per permettere la lettura delle carte geologiche anche in termini di caratteristiche genetiche sequenziali delle successioni rocciose”; e ancora “i progressi delle conoscenze stratigrafiche e sedimentologiche ... impongono una sostanziale revisione dei criteri di studio. ... ciò si configura in pratica nell'uso di un approccio litostratigrafico integrato in tutti i casi possibili con criteri derivati dalla stratigrafia sequenziale”. tale tentativo di integrazione è stato proposto nel foglio 196 cabella ligure (servizio geologico d'italia, in stampa); il foglio è ubicato sul margine sud-orientale del bacino terziario piemontese ed è caratterizzato da unità liguri e subliguri su cui poggia, in discordanza angolare, la successione priaboniano-aquitaniana del bacino terziario piemontese (btp). l'approccio metodologico seguito per il rilevamento e la suddivisione dei soli depositi del btp è di tipo stratigrafico-deposizionale per evidenziare, mediante il riconoscimento delle superfici di discontinuità, la dinamica di crescita del bacino e per legarla con le fasi tettoniche che la controllano; tale approccio si dimostra particolarmente utile nelle zone marino marginali, settori chiave per leggere 49problemi e potenzialità dell’utilizzo delle ubsu ... l'evoluzione del bacino (marroni et alii, in stampa). le superfici fisiche di discontinuità stratigrafica sono segnalate sul terreno dalla presenza di alcuni caratteri, già elencati nel foglio trino, ma nel caso del foglio cabella ligure le superfici identificate sono state utilizzate per la definizione di “unità deposizionali ibride” (mitchum et alii, 1977; di biase, 1998) i cui limiti, a differenza delle ubsu, possono essere tracciati anche in zone dove le superfici inconformi passano a superfici di paraconcordanza. per poter garantire il massimo della correlabilità tra unità riconosciute nel foglio cabella e i fogli limitrofi, all'interno delle unità deposizionali, sono state mantenute le suddivisioni litostratigrafiche, in larga parte corrispondenti con le unità già utilizzate in letteratura; sono proprio le unità litostratigrafiche ad essere cartografate nel foglio alla scala 1:50.000, lasciando ad una carta prototipale (1:25.000) allegata la rappresentazione delle unità deposizionali e agli schemi a cornice del foglio e della carta prototipale le possibilità di lettura incrociata dei due diversi prodotti cartografici. dall'analisi dei fogli descritti emerge chiaramente che l'adozione di un criterio stratigrafico-sequenziale pone un'importante questione di restituzione cartografica delle unità in tutti quei casi in cui si passa dalle superfici di discontinuità alle superfici di continuità ad esse correlabili, dalle porzioni marginali a quelle distali del bacino su cui si sviluppano le sequenze deposizionali. conclusioni l'analisi dei fogli realizzati per il progetto carg mette in evidenza come, in particolari contesti geologici, l'utilizzo di criteri e metodi di stratigrafia fisica sia diventato elemento imprescindibile e necessario alla corretta interpretazione dell'evoluzione dei bacini sedimentari; tuttavia emergono chiaramente anche le diffifig. 2 esempio di rappresentazione cartografica di una superficie di discontinuità (a) attraverso il segno convenzionale “limite stratigrafico inconforme” e quello di “traccia di superficie di discontinuità” (b). example of cartographic representations of an unconformity surface (a): carg existing symbol “unconformity stratigraphic boundary” and new carg symbol “trace of discontinuity surface” (in the circle) (b). coltà connesse alla rappresentazione cartografica di unità diverse da quelle litostratigrafiche, più comunemente e diffusamente utilizzate. nell'ambito delle attività di coordinamento del progetto carg, il comitato d'area appennino settentrionale, partendo dal lavoro svolto dai diversi gruppi di ricerca per la realizzazione dei fogli, ha proposto una soluzione cartografica (http://www.apat.gov.it/ site/ _files/suolocarg/comitato_area_app_sett_febb2006.p df ) a tale problema attraverso la definizione di un nuovo segno convenzionale che renda possibile la massima integrazione tra l'approccio litostratigrafico e i criteri derivati dalla stratigrafia sequenziale, così come indicato e suggerito nel quaderni, vol. 1 (sgn, 1992); fermo restando che il metodo litostratigrafico rimane lo standard per la cartografia geologica ufficiale alla scala 1:50.000, il criterio stratigrafico-sequenziale costituisce l'elemento fondamentale per la produzione di elaborati di sintesi e di lettura integrata dell'evoluzione dei bacini sedimentari. il nuovo segno convenzionale “traccia di superficie di discontinuità” è sinonimo del preesistente “contatto stratigrafico inconforme” ma, a differenza di questo, consentirà di tracciare quelle porzioni di superficie di discontinuità che attraversano unità non ulteriormente distinte (es: abc in fig. 2a e 2b). il nuovo segno convenzionale darà la possibilità di rappresentare in carta un dato fondamentale per garantire la correlabilità tra unità riconosciute nelle aree marginali dei bacini e quelle riconosciute e distinte nelle aree distali degli stessi; tale informazione risulta indispensabile per la definizione di sequenze deposizionali e per la produzione di elaborati di sintesi a scala regionale. opere citate apat (2003) guida italiana alla classificazione e alla terminologia stratigrafica. quaderni serie iii, vol. 9, pp: 155. calabrese l. & di dio g. (in stampa) note illustrative della carta geologica d'italia alla scala 1:50.000 foglio 180 salsomaggiore terme. servizio geologico d'italia -apat, roma. calabrese l. (in stampa) note illustrative della carta geologica d'italia alla scala 1:50.000 foglio 181 parma nord. servizio geologico d'italia apat, roma. dela pierre f., piana f., fioraso g., boano p., forno m.g., violanti d. (2003) note illustrative della carta geologica d'italia alla scala 1:50.000 foglio 157 trino. 147 pp., servizio geologico d'italia apat, roma. di biase d. (1998) stratigrafia fisica, facies e significato dei conglomerati della val borbera (btp). tesi di dottorato, univ. di parma. marroni m., ottria g. & pandolfi l. (in stampa) note illustrative della carta geologica d'italia alla scala 1:50.000 foglio 196 cabella ligure. servizio geologico d'italia apat, roma. mitchum r.m. jr., vail p.r. & thompson s. (1977) seismic stratigraphy and global changes of sea level, part 2. the depositional sequence as basic unit for stratigraphic analysis. in: payton c.e. (ed.), seismic stratigraphy applications to hydrocarbon exploration. am. ass. petr. geol. memoir, 26, 53-62. salvador a. (1994) international stratigraphic guide. a guide to stratigraphic classification, terminology, and procedure . the international union of geological sciences and the geological society of america (eds.): pp. 214. servizio geologico d'italia apat (in stampa) carta geologica d'italia alla scala 1:50.000 foglio 196 cabella ligure. servizio geologico d'italia apat (in stampa) carta geologica d'italia alla scala 1:50.000 foglio 180 salsomaggiore terme. servizio geologico d'italia apat (in stampa) carta geologica d'italia alla scala 1:50.000 foglio 181 parma nord. servizio geologico d'italia apat (2003) carta geologica d'italia alla scala 1:50.000, foglio 157trino. servizio geologico nazionale (1992) carta geologica d'italia 1:50.000 guida al rilevamento. quaderni del servizio geologico d'italia, serie iii, vol. 1. 50 ms. ricevuto il 2 aprile 2008 testo definitivo ricevuto il 17 aprile 2008 ms. received: april 2, 2008 final text received: april 17, 2008 c. d’ambrogi impaginato aprile nnuuoovvee ccoonnoosscceennzzee ssuullllaa ssttrraattiiggrraaffiiaa ee ddiissttrriibbuuzziioonnee ddeeii ddeeppoossiittii iiggnniimmbbrriittiiccii qquuaatteerrnnaarrii nneell ssoottttoossuuoolloo ddeellllaa ppiiaannaa ddeell ssaarrnnoo ((ssaalleerrnnoo--ccaammppaanniiaa)) –– iittaalliiaa mmeerriiddiioonnaallee ffrraanncceessccoo aapprriillee && rroommeeoo mmaarriiaannoo ttooccccaacceellii dip.to scienze della terra , università di napoli “ federico ii”. l.go s. marcellino,10 – 80138 napoli. tel.081/5473313. e-mail: aprile@unina.it riassunto la reinterpretazione critica di dati stratigrafici interessanti il sottosuolo della pianura del fiume sarno, costituente la parte meridionale della piana campana, ha consentito di delineare un nuovo quadro delle caratteristiche stratigrafiche dei terreni vulcanici, olocenici e pleistocenici, di riempimento della piana e in particolare dei depositi ignimbritici. in accordo con recenti studi vulcanologici è stata rilevata la presenza nel sottosuolo della piana di due livelli di tefra da flusso piroclastico; essi sono costituiti, dall’alto verso il basso, dalla ignimbrite campana (39.28±0.11 ka b.p.) presente prevalentemente nella facies del tufo grigio campano e dalla ignimbrite di taurano (157.4±1.00 ka b.p.) in facies di tufo giallo. nella zona pedemontana dei monti di sarno sono stati rinvenuti in sondaggi meccanici, al di sotto dell’ignimbrite di taurano, dei depositi marini alla quota di circa – 35 metri s.l.m. ciò dimostra l’esistenza di una ingressione marina attribuibile ad una tarda fase del pleistocene medio e quindi più antica di quella eutirreniana come finora ipotizzato. altri dati geognostici inoltre hanno portato a limitare l’estensione, nell’entroterra sarnese della suddetta trasgressione eutirreniana. e’ stata inoltre rilevata l’esistenza di una fase tettonica post 39 ka b.p. di modesta entità, che ha dislocato il tetto del tufo grigio campano senza dare luogo a manifestazioni vulcaniche come invece avvenuto nella piana campana a n del somma-vesuvio. abstract new knowledge about stratigraphy and the distribution of quaternary ignimbrite deposits in the subsurface of the sarno plain. (salerno-campania) southern italy. the critical reinterpretation of stratigraphic data concerning the subsurface of the sarno plain, located in the south part of the campania plain, has produced a new picture of the stratigraphy characteristics of the olocene and pleistocene volcanic terrains that fill the plain, in particular the ignimbrite deposits. in agreement with recent volcanological studies the presence of two pyroclastic flow deposits has been pointed out in the subsurface of the sarno plain. as a matter of fact below the campanian ignimbrite, (39.28±0.11 ky b.p.), mostly in the campanian gray tuff facies, the taurano ignimbrite, (157.4±1.00 ky b.p.), in the yellow tuff facies, occurs. in addition a modest tectonic phase dislocating the campanian gray tuff has also been pointed out. moreover this tectonic phase, in the sarno plain was not characterized by volcanic activity contrary to what happened in the campania plain northward of sommavesuvio. the recovery of marine deposits from the subsurface in the piedmont zone of sarno mountains, underlying the taurano ignimbrite at depth of 35 meters below sea level, indicates the existence of a marine trasgression older (middle pleistocene) than the eu-tyrrhenian period to which these deposits have been attribuited. this finding, in association with other geognostic and stratigraphic data, allows a reduction of the geographical extension of the eu-tyrrhenian trasgression in the sarno plain. parole chiave: piana del sarno, tettonica quaternaria, stratigrafia del sottosuolo, depositi piroclastici, depositi marini, ignimbrite campana, italia meridionale keywords: sarno plain , quaternary tectonics, subsoil stratigraphy, pyroclastic deposits, marine deposits,campanian ignimbrite, southern italy. il quaternario italian journal of quaternary sciences 1155(2), 2002, 169-174 11 - pprreemmeessssaa la pianura del fiume sarno, ubicata geograficamente a s dell’edificio vulcanico del somma-vesuvio, rappresenta la parte più meridionale della piana campana che si estende, in direzione appenninica, dal monte massico all’alto strutturale della penisola sorrentina (fig.1). studi specifici sulla piana del sarno sono stati condotti da vari autori, finalizzati prevalentemente alla conoscenza dell’evoluzione geomorfologica quaternaria (cinque et al., 1987; cinque, 1991; barra et al., 1989), dell’archeologia (albore livadie et al., 1990), dell’idrogeologia (celico et al., 1991) e del rischio ambientale (aprile et al., 1998). nel presente lavoro vengono riportati i risultati di uno studio, basato sia sull’esame di dati stratigrafici inediti che sulla reinterpretazione critica di quelli relativi a sondaggi eseguiti nel passato; tale studio mira prevalentemente a delineare la geometria dei tefra da flusso piroclastico presenti nel sottosuolo della piana del sarno, costituiti dall’alto verso il basso, dalla ignimbrite campana presente prevalentemente nella facies del tufo grigio campano e dalla ignimbrite di taurano presente nella facies di tufo giallo zeolitizzato. come è noto i livelli di materiale piroclastico, indipendentemente dai meccanismi deposizionali, rappresentano orizzonti isocroni che assumono particolare rilevanza nelle ricostruzioni paleogeografiche e stratigrafiche (narcisi, 1994). la ridatazione definitiva dei tefra della piana del sarno con metodo radiometrico (rolandi et al., 2000; de vivo et al., 2001) ha consentito quindi di acquisire anche conoscenze inedite sulla cronostratigrafia dei depositi marini connessi alle trasgressioni quaternarie. 170 f. aprile & r.m. toccaeli 22 - llaa ppiiaannaa ddeell ssaarrnnoo.. lliinneeaammeennttii ssttrruuttttuurraallii,, vvuullccaannoollooggiiccii ee ssttrraattiiggrraaffiiccii strutturalmente la piana del sarno (fig.1) costituisce il settore meridionale del vasto graben peritirrenico campano individuatosi probabilmente nel pliocene superiore (ippolito et al., 1973; aprile & ortolani, 1978; 1985) o pleistocene inferiore (cinque et al., 1987) tramite dislocazioni per faglie dirette con direzione appenninica ed antiappenninica. tali faglie hanno smembrato e ribassato il substrato carbonatico meso-cenozoico della piattaforma campano-lucana rispetto agli alti strutturali di identica litologia, che bordano la piana del sarno lungo il margine sud (m. lattari-penisola sorrentina) e ne (monti di sarno-picentini meridionali), originando uno sprofondamento a gradinata dei blocchi carbonatici a profondità crescenti dai bordi verso il centro della piana (cinque et al., 1987) ove raggiungono circa 2000 m di profondità (cassano & la torre, 1987). all’interno di tale zona ribassata è poi avvenuta una intensa aggradazione di depositi continentali, marini e vulcanici. non sono disponibili nella piana del sarno, conoscenze stratigrafiche profonde dirette tranne quelle desumibili dal pozzo geotermico trecase 1 posizionato alla quota di 220 m s.l.m sulle pendici sw del vesuvio. in tale sondaggio è stato riscontrato il basamento carbonatico a –1885 m dal p.c. (balducci et al., 1983) al di sopra del quale sono presenti depositi continentali, marini e vulcanici di varia facies, tra cui banchi di tufo grigio tra –325 e – 510 m dal p.c attribuiti alla ignimbrite campana. la struttura profonda dell’area al di sotto della potente copertura sedimentaria, è stata quindi desunta da studi geofisici. cassano & la torre (1987) con indagini gravimetriche, magnetiche e geoelettriche hanno delineato l’andamento del bedrock carbonatico, accertando inoltre la presenza di una struttura tettonica secondaria il cosiddetto graben di pompeiboscoreale ove le unità carbonatiche raggiungono il massimo approfondimento; bruno et al. (1998) rielaborando dati sismici dell’agip hanno individuato una serie di discontinuità tettoniche che confermano la complessità della struttura profonda di questa porzione del bacino eruttivo e sedimentario campano (fig. 2). correlato alle vicende tettoniche risulta essere il vulcanismo quaternario della piana del sarno comprendente sia i prodotti della ignimbrite campana che quelli del vulcanismo post ignimbritico. ai primi, recentemente ridatati con il metodo 40ar/ 39ar, è stata attribuita un’età di 39.28±0.11 ka b.p (rolandi et al., 2000; de vivo et al., 2001) e risultano presenti nel sottosuolo della piana prevalentemente nella facies del tufo grigio campano (tgc); i prodotti post ignimbritici sono costituiti essenzialmente dai depositi piroclastici del somma–vesuvio emessi durante le fasi pliniane succedutesi negli ultimi 25.000 anni e che nel sottosuolo della piana sono principalmente rappresentati (rolandi et al., 2000) dai prodotti dell’eruzione di sarno (circa 17 ka b.p.) e di ottaviano (circa 8 ka b.p.). l’ignimbrite campana con un volume stimato di circa 150 km3 (de vivo et al., 2001) costituisce il tefra da flusso piroclastico a composizione trachitica più diffuso nella regione. ancora dibattuta è la sua zona d’origine; l’ipotesi di una genesi da collasso della caldera flegrea già avanzata dal rittman (1950) e successivafig. 1 – schema geologico della piana del sarno. 1. lave ultrapotassiche del complesso vulcanico sommavesuvio; 2. flussi piroclastici, surges e lahars del complesso vulcanico somma-vesuvio; 3. depositi piroclastici ed alluvionali della piana campana; 4. unità mesocenozoiche e terziarie dell’appennino meridionale. geological scheme of the sarno plain. 1. ultrapotassic lavas of vesuvius; 2.pyroclastic flows, surges and lahars; 3.pyroclastic and alluvial deposits of campanian plain; 4. mesozoic and tertiary southern apennine formations. fig. 2 – schema strutturale della piana del sarno (da bruno et al.,1998 ridisegnata). 1. isoplete del top del substrato carbonatico (in metri s.l.m); 2. ubicazione delle faglie estrapolate da dati sismici; 3. ubicazione delle faglie interpolate da dati sismici; 4. ubicazione delle faglie da dati bibliografici; 5. graben di pompei (a) e di acerra (b). structural scheme of the sarno plain (from bruno et al., 1998 redrawn). 1. isopleths of the top of the limestone (in meters a.s.l); 2. fault location extrapolated fron seismic data; 3. fault locltion interpoled from seismic data; 4. fault location based on bibliography; 5. graben of pompei (a), graben of acerra (b). mente ripresa da rosi & sbrana (1987) si contrappone a quella avanzata da di girolamo (1968;1970), da barberi et al. (1978), da di girolamo et al. (1984) e da lirer et al. (1987) che ammettono un’origine da sistemi di fratture regionali lungo il bordo settentrionale dei campi flegrei. ancora scandone et al. (1991) ipotizzano un collasso calderico posizionato sulla depressione di acerra a ne di napoli (fig.1); quest’ultima origine viene però esclusa da bruno et al. (1998). rolandi et al. (2000) e de vivo et al. (2001) hanno rilevato sul versante orientale dei monti di sarno,in località taurano,la presenza,in affioramento (figg.1-4), di una più antica formazione ignimbritica,denominata ignimbrite di taurano. quest’ultima si presenta in facies di tufo giallo zeolitico, con tessitura massiva e matrice cineritica compatta, datato con il metodo 40ar/ 39ar 157.4±1.00 ka b.p. a questo più antico tefra che, secondo rolandi et al. (2000), è presente in tutto il sottosuolo della piana è stato dato il nome di tufo giallo di taurano (tgt). questi due depositi da flusso piroclastico del tgc e del tgt, datati radiometricamente, costituiscono quindi due preziosi livelli guida per le ricostruzioni stratigrafiche quaternarie. l’evoluzione geomorfologica quaternaria della piana del sarno e della sua fascia pedemontana, le principali caratteristiche stratigrafiche dei terreni alluvionali e marini pleistocenici ed olocenici di colmamento, sono state studiate da cinque et al. (1987) e da cinque (1991); da tali studi risulta che la piana oltre ad essersi impostata strutturalmente in ritardo, rispetto al settore nord della piana campana, sarebbe poi rimasta sostanzialmente stabile tettonicamente durante il pleistocene superiore-olocene tranne una modesta subsidenza di 171nuove conoscenze sulla stratigrafia ... circa -30 metri negli ultimi 130 ka. valori di subsidenza intorno a -4÷5 m per gli ultimi 2000 anni sono stati osservati per la parte costiera della piana (albore livadie et al., 1991). oltre ad aver individuato le diverse posizioni della linea di costa dal pleistocene superiore all’attuale,cinque (1991) ha distinto nella porzione più superficiale del pacco sedimentario la presenza di depositi in facies di spiaggia correlabili ad ingressioni marine. di queste le più estese nell’entroterra sarnese risultano essere quella di età eu-tirreniana e quella di età versiliana. i sedimenti eu-tirreniani, sempre sottoposti ai prodotti dell’ignimbrite campana, si rinvengono a quote non superiori ai –25 m s.l.m e si estendono secondo cinque et al. (1987), fin sotto i rilievi bordieri dei monti di sarno. i depositi marini versiliani sono invece presenti fino alla zona di pompei-scafati a quote che vanno da alcuni metri sotto il livello del mare a circa +2 metri s.l.m. diffusa inoltre è la presenza in tutto il sottosuolo di depositi lacustri e palustri (torbe e limi) tipici degli ambienti di transizione associati sia alle predette ingressioni che a quelle di età romana e alto-mediovale 33 - ddiissccuussssiioonnee ddeeii ddaattii ee rriissuullttaattii la disponibilità dei dati di nuovi sondaggi meccanici, unitamente alla reinterpretazione critica di quelli eseguiti nel passato, di varia provenienza (da ricerche idriche, dal raddoppio linea fs, da precedenti lavori, da enti pubblici ecc..) per un totale di circa 150 pozzi, di profondità compresa tra i 30 ed i 118 metri dal p.c, ha consentito la ricostruzione, con buona accuratezza, della stratigrafia e struttura della porzione più prossima alla superficie dei terreni vulcanici quaternari. é stato quindi possibile elaborare una carta strutturale dell’andamento del tetto del tufo grigio campano (tgc). la realizzazione di due sezioni geologiche significative pone in evidenza i rapporti tra le unità litostratigrafiche presenti nel sottosuolo. per quanto riguarda l’andamento del tetto del tgc (fig.3) se ne osserva, nel complesso, un aumento progressivo della profondità procedendo dalle zone circostanti i rilievi bordieri verso il centro della piana ove, in corrispondenza del tratto mediano del fiume sarno, coincidente grosso modo con il punto di massimo sprofondamento del graben, raggiunge una profondità di circa –30 metri s.l.m. l’esame delle sezioni geologiche (figg. 4 e 5) restituisce un quadro completo ed inedito della situazione stratigrafica del sottosuolo della piana del sarno. la prima considerazione risulta essere che il substrato portante dello spessore di terreni indagati è costituito dal banco di tgc che, con la sua deposizione, ha praticamente appiattito la precedente morfologia del tufo giallo di taurano. nella sezione di fig. 4 il tetto del tgc, posto ad una profondità compresa tra +10 metri e -30 m s.l.m presenta un andamento generale, dai monti di sarno verso w, immergente gradatamente verso il centro della piana. dalla località messigno in poi il tgc sembra scomparire; tale mancato rinvenimento, come in altre zone della piana, è da addebitare alla limitata profondità d’indagine dei sondaggi in zona; del resto già cassano & la torre (1987) in base ai dati geofisici prolungano la presenza del tgc fino alla costa. analogo andamento denota il tgc nella fig.5 fig. 3 – isoplete del tetto del tufo grigio campano ed ubicazione sondaggi. 1. isoplete del top del tufo grigio campano (in metri s.l.m); 2. sondaggi meccanici; 3. traccia sezione geologica (a-a; b-b; delle figg. 4 e 5). isopleths of the top of campanian gray tuff and location of boreholes. 1. isopleths of the top of campanian gray tuff (in meters a.s.l.); 2. location of boreholes; 3. cross-section marks (a-a; b-b; of figg. 4 and 5); 172 f. aprile & r.m. toccaeli ove esso si presenta con due bancate, provenienti rispettivamente dai monti di castellammare e da sotto l’edificio del somma-vesuvio, che si immergono verso il centro della piana. inoltre in direzione dell’edificio vulcanico del somma-vesuvio si evidenzia una marcata flessura, controllata presumibilmente da strutture disgiuntive, del corpo ignimbritico il cui tetto nel pozzo trecase 1 si posiziona a circa –100 m s.l.m. altro elemento caratterizzante la morfologia del tgc è costituito dalla dislocazione del top con dislivelli dell’ordine di qualche decina di metri. queste soluzioni di continuità nell’andamento del tetto del tgc è l’espressione di una attività tettonica post 39 ka b.p. coeva a quella già individuata nella piana campana a nord del somma-vesuvio (aprile et al.,1992). tale tettonica, successiva alla deposizione del tgc, sembra però avere caratteri meno marcati rispetto a quella a nord del somma-vesuvio sia per la minore entità delle dislocazioni che per la mancanza di prodotti vulcanici all’interno ed al di sopra del tgc. questi ultimi prodotti, costituiti da scorie e brecce laviche, con caratteristiche evolventi verso flussi piroclastici, risultano invece presenti nella parte nord della piana campana e sono stati interpretati come dovuti a manifestazioni ignimbritiche più recenti (circa 20 ka b.p.) causate dalla riattivazione dei sistemi di fratture correlati alle fasi ignimbritiche più antiche (rolandi, 1988; aprile et al., 1992). dall’esame della fig.4 in corrispondenza dei sondaggi meccanici più profondi (ssml6, ssml9, fs136, fs137, sm3, sm2, sm1) si nota, inoltre, la presenza di un altro tefra, separato dal sovrastante tgc da un livelfig. 4 sezione geologica schematica a-a: monti di sarno – foce del sarno. 1. depositi di spiaggia ed eolici attuali e recenti; 2. depositi alluvionali e piroclastiti subaeree (in posto e/o rimaneggiate) recenti del somma -vesuvio( a.d. 79 1944); 3. detriti di falda e di versante s.l.; 4. depositi litorali e di spiaggia con livelli di torba del “complesso versiliano” (olocene); 5. depositi palustri e lagunari associati al “complesso versiliano” (olocene); 6. depositi alluvionali e piroclastiti in posto o rimaneggiate; principalmente attribuibili alle eruzioni di sarno e ottaviano (17 ka e 8 ka b.p.); 7. tufo grigio campano (circa 39 ka b.p.); 8. tufo giallo di taurano (circa 157 ka b.p.); 9. depositi di spiaggia e marini tardo pleistocene medio; 10. termini calcareo-dolomitici mesozoico-terziari; 11. faglia presunta; 12. faglia. schematic geological cross section a-a: mountains of sarno mouth of the sarno river 1. beach and eolian recent deposits; 2. alluvial deposits and recent subaerial pyroclastic products (in situ or reworked) of somma-vesuvius (a.d. 79 1944); 3. talus and slope deposits; 4. beach and shore sediments with peat levels of the versilian complex; 5. palustrine and lagoonal deposits of the versil ian complex; 6. alluvial deposits and undisturbed or reworked pyroclastic deposits of sarno (17 ky b.p.) and ottaviano (8 ky b.p.) eruptions principally; 7. campanian gray tuff (about 39 ky b.p.); 8. taurano yellow tuff (about 157 ky b.p.); 9. beach and marine deposits (late middle pleistocene); 10. dolomites and limestones (mesozoic cenozoic); 11. presumed fault; 12. fault. 173nuove conoscenze sulla stratigrafia ... lo di paleosuolo e di pomici basali.tale formazione si rinviene nel sottosuolo con una notevole estensione areale compresa, tra i rilievi bordieri di sarno fin oltre s. marzano, con una profondità del tetto compresa tra –16 e –30 metri s.l.m; la facies di questo banco da flusso piroclastico è quella di un tufo giallo zeolitico con le stesse caratteristiche petrografiche del tufo giallo di taurano rinvenuto in affioramento (rolandi et al., 2000; de vivo et al., 2001). l’identità nelle caratteristiche petrografiche insieme alla sua posizione stratigrafica (sempre a letto del tgc con paleosuolo e pomici basali interposte) porta quindi a correlare cronostratigraficamente questo tefra con il tufo giallo di taurano (tgt) datato a circa 157 ka b.p. le articolazioni nell’andamento del top del tgt risultano presumilmente dovute ad un modellamento per erosione in ambiente continentale come testimoniato dalla presenza a tetto del paleosuolo. altro dato inedito è il rinvenimento di depositi marini alla profondità di circa –35 m s.lm, al letto del tufo giallo di taurano, in corrispondenza di sondaggi meccanici profondi (ssml6 e ssml9), ubicati sul piedimonte dei monti di sarno (nicotera & civita, 1969). data la loro posizione stratigrafica tali depositi devono essere più antichi di 157 ka b.p; questa constatazione riferita alla cronologia della stratigrafia isotopica marina (williams et al., 1998) consente di attribuire tali sedimenti ad una tarda fase trasgressiva del pleistocene medio, e non a quella eutirreniana cui, come ipotizzato da cinque et al. (1987), tali depositi dovrebbero appartenere. inoltre la totale assenza di depositi marini, al letto del tgc, nei sondaggi esaminati, nel tratto monti di sarno–san marzano (fig.4), porta a ritenere che l’ingressione eutirreniana si sia estesa nell’entroterra non fino ai rilievi bordieri più interni della piana di sarno, ma al più fino alla zona compresa tra scafati e san marzano. fig. 5 sezione geologica schematica b-b: vesuvio – monte pendolo. 1. depositi alluvionali e piroclastiti subaeree (in posto e/o rimaneggiate) recenti; 2. detriti di versante s.l.; 3. depositi di spiaggia ed eolici del “complesso versiliano”; 4. depositi di spiaggia e litorali con livelli di torba del “complesso versiliano”; 5. depositi di conoide alluvionale e coni di deiezione (tardoolocene); 6. depositi alluvionali (tardo-pleistocene); 7. alluvioni post tufo grigio campano del conoide di “scanzano” (pleistocene superiore); 8. piroclastiti e lave dell’edificio vulcanico del sommavesuvio; 9. ignimbrite campana (circa 39 ka b.p.); 10. depositi del conoide di “gragnano” e coni di deiezione più recenti (pleistocene superiore); 11. tufo giallo di taurano (circa 157 ka b.p.); 12. depositi di spiaggia e marini (tardo pleistocene medio); 13. termini calcareo-dolomitici (mesozoico-terziario); 14. faglia presunta; 15. faglia . schematic geological cross section b-b: vesuvius – pendolo mount. 1. alluvial deposits and recent subaerial pyroclastic products (in situ or reworked) of somma-vesuvius (a.d. 79 – 1944); 2. talus and slope deposits; 3. beach and recent aeolian deposits; 4. beach and shore sediments with peat levels of the versilian complex (olocene); 5. late holocene alluvial fans and debris cones deposits; 6. late pleistocene alluvial fans; 7. “scanzano” alluvial fan deposits (upper pleistocene); 8. lavas and pyroclastic products of somma-vesuvius complex; 9. campanian gray tuff (about 39 ky b.p.); 10. “gragnano” alluvial fan deposit and recent alluvial or debris cones deposits (upper pleistocene); 11. taurano yellow tuff (about 157 ky b.p.); 12. beach and marine deposits (late middle pleistocene); 13. dolomites and limestones (mesozoic cenozoic); 14. presumed fault; 15. fault. 174 f. aprile & r.m. toccaeli 44 - ccoonnssiiddeerraazziioonnii ccoonncclluussiivvee lo studio del sottosuolo della piana del sarno ha messo in evidenza aspetti in gran parte inediti che possono riassumersi come segue: presenza in larga parte del sottosuolo della piana del sarno di due distinti tefra ignimbritici sovrapposti ,di cui il superiore, datato 39.28 ± 0.11 ka b.p risulta costituito dalla ignimbrite campana in facies di tufo grigio campano e quello inferiore, datato157.4±1.00 ka b.p risulta costituito dalla ignimbrite di taurano in facies di tufo giallo attr ibuzione ad una tarda fase ingressiva del pleistocene medio e non all’ingressione eutirreniana, come fino ad oggi proposto, dei depositi marini rinvenuti, a letto del tufo giallo di taurano, nei sondaggi situati sul piedimonte dei monti di sarno probabile riduzione dell’estensione nell’entroterra sarnese dell’ingressione marina eutirreniana conferma dell’esistenza di una modesta attività tettonica nella piana del sarno, post 39 ka b.p. con caratteri meno marcati rispetto a quella coeva e di maggiore intensità avvenuta nel settore della piana campana a n del somma-vesuvio llaavvoorrii cciittaattii albore livadie c., barra d., bonaduce g., brancaccio l., cinque a., ortolani f.,pagliuca s. & russo f. 1990 evoluzione geomorfologica,neotettonica e vulcanica della pianura costiera del fiume sarno (campania) in relazione agli insediamenti anteriori all’eruzione del 79 d.c. vulcanol. et archeol., 2255, 237-256. aprile f. & ortolani f. 1978 nuovi dati sulla struttura profonda della piana campana a sud est del fiume volturno. boll. soc. geol. it., 9977,591-608. aprile f. & ortolani f. 1985 principali caratteristiche stratigrafiche e strutturali dei depositi superficiali della piana campana. boll. soc. geol. it., 110044,195-206. aprile f., castaldi v., ortolani f., pagliuca s. & rolandi g. 1992 tettonica e vulcanismo negli ultimi 35.000 anni nella piana campana. atti 1111° convegno g.n.g.t.s. roma, 9 – 11 dic.1992, 425-429. aprile f., ortolani f. & toccaceli r. 1998 proposta di restauro geoambientale della piana del sarno (sa). geologia tecnica & ambientale. n° 22, 31-38. balducci s., vaselli m. & verdiani g. 1983 – exploration well in the ottaviano permit, italy, trecase 1. eur. geot. update, 33rrdd intern. sem., munich, 29 nov.1 dic., 407-418. barberi f., innocenti f., lirer l., munno r., pescatore t. & santacroce r. 1978 – the campanian ignimbrite: a major prehistoric eruption in the neapolitan area (italy). bull.volcanol. 4411(1), 1-22. barra d., bonaduce g., brancaccio l., cinque a., ortolani f., pagliuca s. & russo f. 1989evoluzione geologica olocenica della piana costiera del fiume sarno. mem. soc. geol. it. 4422, 255-267. bruno g., cippitelli g., rapolla a. 1998 seismic study of the mesozoic carbonate basament around mt. somma – vesuvius, italy. journal of volcanology and geothermal research 8844, 311-322. cassano e. & la torre p. 1987 geophysics in somma-vesuvius. quaderni della ricerca scientifica, cnr, 88,175-196. celico p., malafronte a. & piscopo v. 1991 bilancio ideologico e idrodinamica della piana del sarno (sa). i° convegno naz. giovani ricercatori in geologia appl.suppl. n. 9933, 297-306 . univ. studi di milano. gargnano (bs), 22-23 ottobre 1991. cinque a., alinaghi h.h., laureti l. & russo f. 1987 osservazioni preliminari sull’evoluzione geomorfologia della piana del sarno. (campania, appenino meridionale). geogr. fisica e dinamica quaternaria, 1100,161 – 174. cinque a. 1991la trasgressione versiliana nella piana del sarno (campania). geogr. fisica e dinamica quaternaria, 1144, (1), 63-71. de vivo b., rolandi g., gans p.b., calvert a., bohrson w.a., spera f.j., h.e. 2001 -new constraints on the pyroclastic eruptive history of the campanian volcanic plain ( italy). mineralogy and petrology,7733, (1-3), 47-65. di girolamo p.1968petrografia dei tufi campani: il processo di pipernizzazione (tufo-tufo pipernoide-piperno). rend.acc.sc.fis.matem. in napoli. serie 44, xxxv, 1-70. di girolamo p.1970 differenziazione gravitativa e curve isochimiche nella ignimbrite campana. rend. soc. it. mineral.petrol. 26 (22), 547-588. di girolamo p., ghiara m.r., lirer l., munno r ., rolandi g. & stanzione d. 1984 vulcanologia e petrologia dei campi flegrei. boll. soc. geol. it., 110033, 349-413. ippolito f., ortolani f., & russo m. 1973 struttura marginale tirrenica dell’appennino campano: reinterpretazione di dati di ricerche di idrocarburi. mem.soc.geol.it.,1122, 228-249. lirer l., luongo g., scandone r. 1987 on the volcanological evolution of campi flegrei. eos, trans. am. geophys. union, 6688, 226-334. narcisi b. 1994 tefracronologia in aree non vulcaniche: principi, metodi di indagine e stato dell’arte nel contesto italiano. il quaternario, 7, (2), 545-554. nicotera p. & civita m. 1969 indagini idrogeologiche per la captazione delle sorgenti di s.marina (sarno). mem. ist. geol. appl. napoli, 1111, 25-44. rittman a.1950 sintesi geologica dei campi flegrei. boll. soc. geol. it., lxix(iiii),117-128. rolandi g.1988 – le ignimbriti della piana campana. atti 74° congresso soc.geol.it., bb, 350-352 rolandi g., bertollini f., cozzolino g., esposito n., sannino d. 2000 sull’origine delle coltri piroclastiche presenti sul versante occidentale del pizzo d’alvano ( sarno – campania ). quaderni di geologia applicata , 77 – 1, 37-47. rosi m. and sbrana a. (editors),1987 the phlegrean fields. quaderni della ricerca scientifica, cnr, 111144, 9,175. scandone r., bellucci f., lirer l.& rolandi g. 1991 the structure of the campanian plain and the activity of the neapolitan volcanoes (italy). j. volcanol. geotherm. res. 4488,1-31. williams d.f., thunell r.c., tappa e. & raffi i. 1998 chronology of the pleistocene oxygen isotope record. 0-1.88 m.y b.p. palaeogeogr. palaeoclim. palaeocol., 6644, 221-240. ms. ricevuto il 19 febbraio 2002 testo definitivo ricevuto il 25 giugno 2002 ms. received: february 19, 2002 final text received: june 25, 2002 imp. aucelli & ll’’eevvoolluuzziioonnee rreecceennttee ddeellllaa ccoossttaa mmoolliissaannaa ((iittaalliiaa mmeerriiddiioonnaallee)) ppiieettrroo ppaattrriizziioo cciirroo aauucceellllii11,, ppaaoollaa iissaabbeellllaa ffaaiillllaaccee11,, ppaaoolloo ppeelllleeggrriinnoo22,, ccaarrmmeenn mmaarriiaa rroosssskkooppff11 && nniiccoollaa ssccaappiillllaattii22 1 dipartimento di scienze e tecnologie per l’ambiente e il territorio, università degli studi del molise, isernia 2assessorato ai lavori pubblici regione molise, campobasso riassunto: aucelli p. et al., l’evoluzione recente della costa molisana (italia meridionale). (it issn 0394 – 3356, 2004). nell’ambito del presente lavoro è stato effettuato uno studio dell’evoluzione geomorfologica recente del litorale molisano e, in particolare, delle variazioni più recenti della linea di costa, ricostruite con l’ausilio di un gis ed analizzate per tratti costieri e periodi distinti (1869-1907, 1907-1954, 1954-1992, 1992-1998). in particolare, si è proceduto ad una determinazione delle variazioni sia lineari della linea di riva che areali, cioè relative alle superfici di spiaggia. in base alle ricostruzioni effettuate, l’evoluzione più recente del litorale si articola in due fasi principali. una prima fase di dominante progradazione che termina all’inizio del 1900, e che trova la sua principale espressione nella costruzione degli apparati deltizi dei corsi d’acqua principali (fiumi trigno e biferno), e una seconda fase in cui si assiste ad una progressiva erosione dei delta. tale erosione, inizialmente bilanciata dalla progradazione dei tratti di costa immediatamente adiacenti alle foci, è seguita da una tendenza prevalente all’arretramento della linea di costa che persiste ancora oggi. circa le cause di tali modificazioni, l’esame dei fattori meteo-climatici, degli interventi sui sistemi fluviali e delle variazioni dell’uso del suolo suggeriscono la sovrapposizione tra fattori di controllo climatico e fattori antropici. quest’ultimi, in particolare, sembrano rafforzare i primi fino a sostituirsi ad essi in termini di importanza. per quanto riguarda le attuali dinamiche e tendenze evolutive del sistema costiero, emerge l’importanza di approfondire le relazioni esistenti tra fattori meteo-marini e dinamica costiera, e tra quest’ultima e la messa in opera di strutture protettive, al fine di definire al meglio ogni futuro intervento e migliorare le condizioni di salvaguardia. abstract: aucelli et al., the recent evolution of molise coast (southern italy). (it issn 0394 – 3356, 2004). this study deals with the recent geomorphological evolution of the sector of the adriatic coast referring to the molise region. the analysis was based on the examination of topographic sheets and aerial photographs referring to the period 1869-1998 and on field surveys to verify and integrate geomorphological data, and to analyse present trends and coastal dynamics. taking into account morphological and related hydrological features, the coast was subdivided into three sectors (from north to south sectors a, b and c). the collected data were analysed and compared by using a gis (software arc view) to obtain quantitative results about the changes of the shoreline and the beach surface which affected the three distinguished sectors during different periods (1869-1907, 1907-1954, 1954-1992 and 1992-1998). for the first period, with reference to data obtained for the sector including the biferno river mouth (sector c), a substantial stability of the delta and positive beach variations can be evidenced. within the second period, an inversion of tendency occurred and the erosion of the main fluvial deltas (the trigno delta in sector a and the biferno delta in sector c) started. the river mouths erosion was accompanied by the progradation of the adjacent coast sectors giving rise to a general positive beach surface variation. during the following periods (1954-1992 and 1992-1998), the shoreline retreat largely persisted affecting sectors a and c, while sector b was characterised by a slight progradation. on the basis of discussed data, two main evolutive phases can be reconstructed. the first one is characterised by prevailing progradation which lasted at least to 1907 and is evidenced in the study area by the construction of the trigno and biferno delta’s. the second phase is controlled by progressive beach erosion, at present still active. the phase of prevailing progradation can be related most probably to the last cold fluctuations of the little ice age, although man induced changes of land-use may have played an important role by favouring soil erosion and sediment production. conversely, the following phase of erosion can be mostly related to the progressive amelioration of climatic conditions after the little ice age and to the relative hydrological changes, combined with land-use changes essentially related to land-abandonment and, in the last decades, to the interventions on the fluvial systems as gravel mining, channel management and daming. parole chiave: evoluzione geomorfologica recente, variazioni della linea di costa, analisi gis, molise, italia meridionale. keywords: recent geomorphological evolution, shoreline changes, gis analyses, molise, south italy. il quaternario italian journal of quaternary sciences 1177(1), 2004, 21-31 11.. pprreemmeessssaa gli ambienti costieri sono soggetti ad un delicato equilibrio che dipende in crescente modo dall’azione esercitata dall’uomo. ad un progressivo degrado delle aree costiere, oltre alla loro crescente antropizzazione, sembrano maggiormente contribuire interventi sempre più numerosi sia diretti che indiretti sui sistemi fluviali, tali da rendere di difficile valutazione le possibili influenze climatiche e meteo-marine. secondo stime recenti (aminti & pranzini, 1993), circa il 63% delle spiagge italiane, tra naturali e protette, può considerarsi in equilibrio, il 32% risulta in erosione e solo il 5% è caratterizzato da una tendenza all’avanzamento. ai fenomeni di erosione costiera, che assumono una sempre maggiore importanza anche nell’area molisana, l’uomo tenta di porre rimedio attraverso la costruzione di opere di difesa costiera. così, circa il 40% della costa molisana risulta attualmente dotata di strutture di protezione trasversali e/o longitudinali. tali strutture di protezione, tuttavia, non sempre si sono dimostrate sufficientemente efficienti al fine di limitare l’erosione in atto. da ciò emerge chiaramente, che la scelta delle tipologie di strutture protettive e delle relative modalità di messa in opera non possono prescindere da una visio22 p.p.c. aucelli et al. ne articolata della dinamica costiera e dei fattori che influiscono sul bilancio sedimentario, nonché della tendenza evolutiva del settore costiero in esame. acquisire informazioni in tal senso rappresenta, dunque, il presupposto per la salvaguardia delle aree costiere. in tale ottica è stato avviato uno studio sulla evoluzione recente, la tendenza evolutiva e la dinamica attuale del litorale molisano di cui la presente nota riassume i primi risultati. 22.. iinnqquuaaddrraammeennttoo ggeeooggrraaffiiccoo ee aapppprroocccciioo mmeettooddoollooggiiccoo il litorale molisano si estende per una lunghezza di circa 35 km tra lo sbocco sul mare del formale del molino (posto circa 1,5 km a nord della foce del fiume trigno) e la foce del torrente saccione (fig. 1). orientato in direzione ca. nw-se, è costituito in prevalenza da costa bassa, comprendente piccole pianure alluvionali costiere e cordoni dunari con antistanti spiagge, e da brevi tratti di costa alta, localizzati in corrispondenza del promontorio di termoli e lungo il versante di petacciato ed intagliati su terreni d’età plio-pleistocenica. i bacini idrografici dei corsi d’acqua che sfociano lungo il litorale molisano (fiumi trigno, biferno e saccione, e corsi d’acqua minori a loro interposti) sono impostati in prevalenza su terreni arenaceo-marnosi e pelitico-argillosi, con affioramenti limitati di terreni calcarei, più estesi soltanto nel bacino del fiume trigno. complessivamente, tali terreni godono di un’elevata erodibilità, come conferma anche la diffusa presenza di fenomeni franosi e di erosione idrica accelerata. ciò si traduce in apporti alle foci prevalentemente pelitico-sabbiosi. le spiagge presenti lungo il litorale molisano, di conseguenza, sono a granulometria prevalentemente fine. procedendo da nw verso se, si rinvengono (fig. 1) le spiagge di costa verde, di marinelle, di marina di petacciato, di foce dell'angelo, di sant'antonio, di rio vivo, di campomarino, di marinelle nuove, di nuova cliternia e di ramitelli. si tratta di spiagge generalmente sabbiose, larghe alcune decine di metri, con delle dune sabbiose alle spalle. nel tratto intorno alla foce del fiume trigno (compreso tra le spiagge di costa verde e di marinelle) l’arenile è prevalentemente ghiaioso. il fondale marino posto tra la battigia e l’isobata di 5 m è caratterizzato dalla presenza di barre e cordoni sottomarini in serie, e da pendenze comprese tra 0,5 e 1,2% (zunica & girardi, 1984). un recente rilievo batimetrico del tratto di costa che dal porto di termoli si estende poco oltre la foce del biferno (assessorato ai lavori pubblici della regione molise, 2001), indica pendenze locali anche superiori al 2%. partendo da un esame preliminare della morfologia costiera e tenendo conto dell’importanza che gli apporti fluviali assumono nel bilancio costiero, la costa in esame è stata suddivisa in tre tratti (fig. 1). il primo e il terzo comprendono rispettivamente le foci dei fiumi trigno e biferno, il secondo tratto, interposto ai precedenti, risulta privo di importanti foci fluviali. l’esame geomorfologico della costa e le relative analisi quantitative sono state compiute sulla base di carte topografiche, foto aeree e ortofotocarte piane che fig. 1 – ubicazione dell’area di studio. location map of the study area. hanno consentito delle analisi comparative per gli ultimi 130 anni circa. in particolare, si è fatto uso di carte topografiche rispettivamente in scala 1:50.000 (edizioni dell’i.g.m.i. del 1869/1875 e relativi aggiornamenti del 1907/1909), 1:25.000 (i.g.m.i., 1954) e 1:5.000 (carta tecnica regionale del molise, 1992), di foto aeree in scala 1:33.000 (i.g.m.i, 1954/55) e 1:13.000 (r.t.a., 1992), nonché di ortofotocarte in scala 1:10.000 (a.i.m.a., 1998). sono state esaminate inoltre alcune carte storiche come ad esempio l’atlante geografico del regno di napoli (rizzi-zannoni, 1808) che, pur fornendo indicazioni interessanti, ovviamente non sono risultate di sufficiente precisione e dettaglio per essere utilizzate nell’analisi comparativa quantitativa. 33.. eevvoolluuzziioonnee rreecceennttee ddeellllaa ccoossttaa mmoolliissaannaa 33..11.. aannaalliissii ggeeoommoorrffoollooggiiccaa l’analisi geomorfologica è consistita in dettagliati esami cartografici ed aerogeologici, integrati da sopralluoghi lungo la costa finalizzati alla verifica ed integrazione dei dati acquisiti, e all’analisi dei tratti costieri distinti riguardo alla loro tendenza evolutiva e dinamica attuale. il tratto a il tratto a, della lunghezza di ca. 6,50 km, è compreso tra lo sbocco a mare del formale del molino (limite regionale tra abruzzo e molise) e quello del torrente tecchio (fig. 1). questo tratto è caratterizzato da una costa bassa e una fascia litorale con quote massime intorno ai 4-5 m s.l.m. dall’esame dell’atlante geografico del regno di napoli (rizzi-zannoni, 1808) e della cartografia storica dell’i.g.m.i. (1875/1907) si evince la presenza di un delta a cuspide in corrispondenza della foce del fiume trigno, caratterizzato da tre canali distributori principali, disposti a ventaglio. il tratto terminale del trigno mostra una morfologia a canali intrecciati con barre attive prive di vegetazione, interrotta da un breve tratto ad ampia sinuosità precedente la foce. a testimonianza dello stadio “giovane” dell’apparato deltizio si evidenzia una fascia a vegetazione palustre interposta tra l’odierna strada litorale e i sedimenti sabbiosi formanti gli apici del delta e i cordoni lateralmente a contatto. la netta deviazione verso nw dei tratti terminali di alcuni torrenti che sfociano in sinistra del trigno (ad es. lo stesso formale del molino) sembra indicare una direzione dominante della deriva litorale dei sedimenti (longshore drift) da se verso nw. confrontando la carta topografica del 1875 con quella del 1907 non si evidenziano variazioni nella conformazione del tratto costiero. per il periodo 1907-1954, il confronto delle relative carte topografiche evidenza una significativa erosione dell’apparato deltizio del trigno, accompagnata da una ridistribuzione dei sedimenti e una progradazione dei tratti di costa adiacenti la foce. nel 1954 non resta che un debole accenno all’originaria forma a cuspide del delta. la fascia costiera intorno alla foce risulta intensamente coltivata e si evidenzia solo qualche debole traccia dei vecchi canali distributori (in particolare del canale destro). la foce si trova spostata verso nw di ca. 500 m, indicando la dominanza di un longshore drift sempre 23l’evoluzione recente ... da se verso nw. a testimoniare la tendenza all’arretramento della linea di riva all’epoca già in atto, il tratto di costa in sinistra idrografica del trigno, e quello in sua destra compreso tra le foci del fosso mergola e del torrente tecchio (fig. 1), si mostrano interessati da vistosi processi di insabbiamento legati all’erosione della spiaggia e allo spostamento verso l’interno della fascia dunare. l’insabbiamento, che in destra del trigno si spinge localmente fino alla ss n.16 adriatica, interessa una fascia di litorale caratterizzata dalla presenza di parcelle di terreno ad assetto regolare, probabilmente adibite ad uso balneare. in destra del trigno, per ca. 1,5 km, la spiaggia appare completamente erosa e caratterizzata da una microfalesia. la linea di riva così individuata tronca nettamente e in senso obliquo i cordoni caratterizzanti il fianco destro dell’apparato deltizio. nel periodo dal 1954 al 1992 si registra un significativo arretramento della costa che interessa tutto il tratto in modo più o meno uniforme, ad eccezione della porzione posta tra le foci del mergola e del tecchio dove avviene addirittura un moderato avanzamento. non emergono, per quanto deducibile dalle fonti bibliografiche esaminate (giorgi et al., 1984; zunica & girardi, 1984), inversioni di tendenza. le stesse fonti confermano per i periodi 1954-1975 e 1975-1980 la variazione negativa della linea di riva in questo tratto e un verso del trasporto solido lungo riva da se verso nw. le poche opere di difesa realizzate tra il 1954 e 1992 sono costituite da pennelli ortogonali a protezione delle foci del formale del molino e del trigno, e dalle strutture longitudinali aderenti in corrispondenza dell’idrovora di montenero di bisaccia. dal 1992 al 1998 si verifica un ulteriore arretramento sia in sinistra della foce del trigno che in sua destra, tra la stessa foce e l’idrovora di montenero di bisaccia. risulta, invece, ancora in leggero avanzamento il tratto tra le foci del mergola e del tecchio. in questo periodo, a protezione della spiaggia di costa verde oramai quasi del tutto erosa e delle associate strutture turistiche, vengono realizzate, anche a sostituzione di quelle preesistenti, delle scogliere emerse e sommerse distaccate, disposte parallelamente o con andamento obliquo alla costa attuale lungo tutto il tratto di costa in sinistra della foce del trigno. il tratto b il tratto b si estende per circa 13 km a partire dalla foce del torrente tecchio fino alla punta del promontorio di termoli (fig. 1). in questo tratto, a parte la piccola pianura alluvionale del torrente sinarca e le spiagge di marina di petacciato, di foce dell ’angelo e di sant’antonio, la fascia litorale si riduce ad un sottile nastro di spiaggia che borda i r i l ievi coll inari di petacciato e il promontorio di termoli. mentre i primi sono impostati su un substrato essenzialmente argilloso (argille grigio-azzurre plio-pleistoceniche) interessato da diffusi e complessi fenomeni franosi, il promontorio, con una morfologia tipica da costa alta terrazzata, è caratterizzato da terreni sabbioso-conglomeratici di ambiente continentale e marino (alluvioni terrazzate di iii ordine, conglomerati di campomarino e sabbie di serracapriola del foglio 155 della carta geologica d’italia). analizzando le cartografie storiche (1869/1907), quelle del 1954 e 1992 e le ortofotocarte del 1998, 24 emerge un modesta tendenza alla progradazione di questo tratto costiero, con alcuni settori in leggero arretramento e altri in avanzamento. dati confrontabili vengono forniti da giorgi et al. (1984) che indicano non solo un comportamento diverso da settore a settore, ma anche delle inversioni di tendenza in determinati settori. così ad esempio il litorale nord di termoli risulta in avanzamento nel periodo 1954-1975 e in arretramento nel periodo 1975-1980. per quest’ultimo periodo si evidenzia un orientamento della deriva litorale prevalente da w verso e (parea, 1978; zunica & girardi, 1984). considerando il periodo 1954-1998, l’avanzamento della linea di costa più significativo si registra nell’area di marina di petacciato. ad eccezione delle scogliere longitudinali aderenti poste immediatamente in destra della foce del tecchio, oggi non più rilevabili, le opere di difesa costiera presenti in questo tratto risalgono all’ultimo ventennio. queste consistono soprattutto in scogliere longitudinali distaccate presenti lungo tutto il tratto di costa tra gli sbocchi del tecchio e del fosso del lupo e, più diradate, lungo il litorale nord di termoli e lo stesso promontorio. a queste si aggiungono una serie di pennelli ortogonali ubicati in corrispondenza dello sbocco del fosso colle degli ulivi (posto a distanza circa uguale tra le foci del torrente tecchio e del fosso del lupo) e lungo il litorale nord di termoli, che sono stati realizzati rispettivamente prima del 1992, e tra il 1992 e 1998. dopo il 1998 vengono eseguiti ulteriori interventi con la realizzazione di scogliere longitudinali distaccate nel tratto tra le foci del fosso del lupo e del torrente sinarca. il tratto c il terzo tratto si estende tra il porto di termoli e la foce del torrente saccione per una lunghezza di ca. 15,5 km. esso è caratterizzato, ad eccezione di un primo settore a costa alta posto tra il porto di termoli e la p.ta di pizzo, da una costa bassa e una piana costiera delimitata verso l’interno da rilievi collinari debolmente degradanti verso mare con locali raccordi morfologici a più alta pendenza. l’esame dell’atlante geografico del regno di napoli (rizzi-zannoni, 1808) e della carta topografica i.g.m.i. del 1869 mette in evidenza una prima fase di variazione positiva della linea di costa, marcata dalla costruzione di un apparato deltizio in corrispondenza della foce del biferno. si tratta di un delta a cuspide piuttosto prominente caratterizzato dalla presenza di depressioni occupate da piccoli stagni costieri come ad esempio il pantanello segnato in sinistra della foce. il confronto delle edizioni del 1869 e del 1907 della carta topografica i.g.m.i. mette in evidenza alcuni interessanti aggiornamenti. in particolare, questo confronto mostra, a parte i cambiamenti morfologici della porzione centrale del delta del biferno, l’avanzamento significativo del tratto di costa tra la foce del biferno e lo sbocco del collettore principale bonifica di ramitelli, con valori massimi in corrispondenza del lido di campomarino. ciò sembra indicare, peraltro, una direzione di trasporto litoraneo lungo costa prevalente da nw verso se. in sinistra della foce, i pantani risultano sostituiti da ampie aree a vegetazione paludosa. tra il 1907 e il 1954 avviene un significativo arretramento del delta che comporta una troncatura in senso obliquo delle barre sabbiose, mentre si registra un ulteriore modesto avanzamento della linea di costa in sua destra, in corrispondenza della spiaggia di marinelle nuove. nel 1954, la foce del biferno risulta molto meno prominente e ridotta ad una morfologia leggermente arcuata con bocca orientata verso n, ed i pantani in sua destra trasformati in aree paludose. a testimonianza della tendenza all’arretramento in atto, si hanno sia in sinistra che in destra idrografica della foce ampi tratti di costa soggetti ad insabbiamento. l’insabbiamento interessa una fascia di terreno larga fino a 125 m, caratterizzata da un assetto parcellare dovuto presumibilmente al suo uso balneare. durante il periodo 1954-1992, oltre ad assistere ai fenomeni di arretramento più cospicui, si verifica una maggiore diversificazione del tratto costiero in relazione alle dominanti tendenze evolutive. tale diversificazione emerge chiaramente sia dall’analisi cartografica che dall’esame dei dati raccolti da giorgi et al. (1984) e da zunica & girardi (1984). i primi, in particolare, evidenziano, per il periodo 1954-1975, il settore in sinistra del biferno in avanzamento, e quello in destra a settori alterni in avanzamento e in arretramento. osservazioni relative al periodo 1975-1980 mostrano alcune inversioni di tendenza, interessanti ad esempio il tratto in sinistra della foce del biferno e quello compreso tra il collettore principale bonifica di ramitelli e la foce del torrente saccione. in relazione all’intero periodo 1954-1992, l’arretramento della linea di riva costituisce la tendenza dominante. il tratto maggiormente colpito è quello compreso tra la spiaggia di rio vivo e il collettore principale bonifica di ramitelli, a conferma di una tendenza già evidenziata da giorgi et al. (1984) per il periodo 1975-1980 e da zunica & girardi (1984), e ciò nonostante questo tratto fosse già all’epoca dotato di opere di protezione emergenti sia longitudinali (in prevalenza distaccate) che trasversali. risultano invece in avanzamento il breve tratto corrispondente al lido di campomarino, il tratto compreso tra il porto di termoli e la spiaggia di rio vivo, e quello tra il collettore principale bonifica di ramitelli e la foce del saccione ad eccezione del settore meridionale della spiaggia di nuova cliternia. tra il 1992 e 1998 si registrano ulteriori arretramenti in corrispondenza della spiaggia di rio vivo lungo le sezioni non protette, tra la foce del biferno e il lido di campomarino, dove si osserva una accentuazione dei tomboli a tergo delle scogliere longitudinali, e infine, nella porzione più settentrionale della spiaggia di nuova cliternia. i restanti settori possono considerarsi sostanzialmente in equilibrio, a parte il settore immediatamente a contatto con il molo sud del porto di termoli, caratterizzato da un ulteriore significativo avanzamento della spiaggia. a prescindere dalle opere di protezione già menzionate, da qualche pennello ortogonale in corrispondenza del porto di termoli, e dalle armature delle foci del biferno e del saccione, le restanti opere di protezione oggi insistenti su questo tratto sono state realizzate durante gli ultimi 20 anni ca. queste consistono in una doppia (localmente tripla) fila di scogliere longitudinali tra aderenti e distaccate nel settore a sud del porto di termoli a protezione della spiaggia di rio vivo (fig. 2), una fila di scogliere longitudinali distaccate ricoprendo un tratto di ca. 7 km tra la foce del biferno e il collettore principale bonifica di ramitelli, e una doppia fila di scop.p.c. aucelli et al. 25 gliere rispettivamente distaccate e aderenti (quest’ultime saldate alla linea di costa attraverso dei tomboli) in corrispondenza del lido di campomarino. e’ stato realizzato, infine, il rafforzamento delle strutture protettive del porto di termoli con la costruzione dell’avamporto e la fortificazione del molo sud. circa le interferenze tra tali strutture di protezione e le evidenziate tendenze evolutive, i dati finora acquisiti non restituiscono un quadro univoco. infatti, sembra logico mettere in relazione la progradazione del tratto in corrispondenza del lido di campomarino e quello posto immediatamente a sud del porto di termoli con la presenza, rispettivamente, delle scogliere e delle strutture portuali. la progradazione consistente del secondo tratto, infatti, sembra essere chiaramente favorita dalla presenza delle strutture portuali che causano fenomeni di diffrazione del moto ondoso (aucelli et al., 2004) tenendo conto che il drift avviene da nw verso se (parea, 1978; zunica & girardi, 1984). di più difficile comprensione risulta invece ad esempio il fatto che le scogliere lungo il tratto compreso tra la foce del biferno e il collettore principale bonifica di ramitelli, esistenti da oltre 20 anni e più volte rafforzate nel tempo, non sembrino aver impedito il progredire dell’erosione. e’ in questo tratto che si hanno chiare evidenze del fatto che l’erosione non interessa solamente la spiaggia emersa ma anche i fondali antistanti come mostra il recente rilievo batimetrico (assessorato ai lavori pubblici della regione molise, 2001) del tratto compreso tra il porto di termoli e la foce del biferno che mette in evidenza pendenze superiori al 2% nelle sezioni interposte tra le opere protettive. 33..22 aannaalliissii qquuaannttiittaattiivvaa al fine di poter valutare in termini quantitativi le avvenute variazioni della linea di costa e di permettere una loro migliore visualizzazione, le carte topografiche e le ortofotocarte piane sono state digitalizzate, georeferenziate e messe a confronto utilizzando i software gis arc-view e autocad map. i tratti costieri distinti sono stati separatamente analizzati per i periodi 1869-1907, 1907-1954, 1954-1992 e 1992-1998. le operazioni di calcolo effettuate hanno consentito di effettuare delle valutazioni sia in termini lineari (entità di avanzamento e arretramento della linea di costa) che areali (variazioni positive e negative delle superfici di spiaggia). fig. 3 – le foci dei fiumi biferno (a) e trigno (b). the river mouths of the biferno (a) and trigno (b) rivers. fig. 2 – esempi di difesa costiera lungo la spiaggia di rio vivo, rappresentati (a) da una barriera di massi a protezione delle abitazioni e (b) da una doppia scogliera indicata attraverso le due frecce. examples of coast protection along the rio vivo beach, represented (a) by a barrier made of boulders to protect the houses and (b) a double row of longitudinal barriers marked by the two arrows. l’evoluzione recente ... 26 le variazioni lineari l’esame della cartografia storica ha mostrato una importante fase di progradazione delle spiagge e degli apparati deltizi che sembra aver perdurato fino all’inizio del 1900. infatti, il confronto tra le carte topografiche storiche dell’i.g.m.i. che rappresentano il tratto comprendente la foce del biferno (tra quelle esaminate le uniche a mostrare un aggiornamento), evidenzia, per il periodo 1869-1907, un avanzamento significativo del fianco destro del delta con un valore massimo di ca. 750 m (19,7 m/anno) in corrispondenza del lido di campomarino, mentre nullo o trascurabile si figura l’arretramento degli apici del delta. anche se, in mancanza di fonti cartografiche adeguate, non è stato possibile verificare questa tendenza per gli altri tratti di costa, questo dato consente di affermare che, almeno in quel tratto, una tendenza all’arretramento non si manifesta prima del 1907. conseguenza dell’erosione degli apparati deltizi nel periodo 1907-1954, con valori massimi di arretramento rispettivamente di circa 500 m per il trigno e di 650 m per il biferno (10,6 e 13,8 m/anno rispettivi), è l’evoluzione delle foci verso una morfologia di tipo wavedominated (fig. 3). tale erosione è accompagnata da una chiara progradazione dei tratti di costa adiacenti (fig. 4a, 4c), a testimonianza della ridistribuzione dei sedimenti di foce ad opera di correnti lungo costa. per l’intero periodo, tale progradazione è valutabile per i tratti contigui alla foce del trigno (comprendenti le spiagge di costa verde in sinistra idrografica, e il tratto tra l’idrovora di montenero di bisaccia e la spiaggia di marina di petacciato in destra) in complessivi 250 m circa (ca. 5.3 m/anno), e in circa 400 m (ca. 8,5 m/anno) per il tratto posto in destra della foce del biferno, compreso tra il lido di campomarino e la spiaggia di nuova cliternia. per le spiagge più distanti dalle principali foci si evidenzia, per lo stesso periodo, una relativa stabilità con tratti in debole avanzamento o arretramento (fig. 4b). nel periodo successivo (1954-1992), il tratto costiero intorno alla foce del trigno (fig. 5a), compreso tra la spiaggia di costa verde e la foce del fosso mergola, subisce un arretramento valutabile in circa 150 m (ca. 4 m/anno). nel tratto successivo (fig. 5b), fino alla spiaggia di marina di petacciato, la linea di costa avanza mediamente di circa 30 m, mentre resta praticamente invariata la sua posizione lungo il litorale nord di termoli. il tratto costiero compreso tra il porto di termoli e la spiaggia di rio vivo (fig. 5c) registra un avanzamento massimo di ca. 180 m, mentre quello adiacente, esteso fino al lido di campomarino, arretra in media di 200 m (ca. 5,3 m/anno), con valori locali anche superiori ai 250 m. in sostanziale equilibrio il restante litorale, compreso tra la spiaggia di marinelle nuove e quella di ramitelli, in cui si alternano tratti in debole avanzamento ed erosione. tra il 1992 e 1998, sia in sinistra che in destra idrografica della foce del trigno (fig. 6a), si registra ancora un valore medio di arretramento piuttosto elevato di 45-50 m (ca. 8 m/anno). risulta invece stabile la foce, probabilmente grazie alla costruzione di pennelli ai suoi lati. variazioni significative si rilevano ancora per la foce del biferno (fig. 6c) che risulta arretrata di circa 120 m (20 m/anno). le variazioni areali ad integrazione dei dati circa le variazioni lineari è stata compiuta un’analisi delle variazioni positive e negative della superficie di spiaggia nei vari periodi e tratti distinti i cui risultati sono stati sintetizzati nella tabella 1. limitatamente al tratto comprendente la foce del biferno è possibile mettere in evidenza per il periodo 1869-1907 una variazione positiva molto consistente di complessivi 1,7 km2 ca. (1.692.500 m2). questa variaziofig. 4 – variazioni della linea di riva e dei principali canali fluviali nel periodo 1907-1954. tratti costieri che hanno subito 1) marcato arretramento, 2) leggero arretramento, 3) marcata progradazione, 4) leggera progradazione. changes of shoreline and main fluvial channels from 1907 to 1954. coast sectors affected by 1) marked retreat, 2) slight retreat, 3) marked progradation, 4) slight progradation. p.p.c. aucelli et al. ne positiva è in gran parte imputabile all’aumento della spiaggia nel tratto compreso tra la foce del biferno e il collettore principale bonifica di ramitelli, valutabile in ca. 1.655.000 m2. l’analisi delle variazioni per periodi distinti mette in evidenza per il periodo 1907-1954 un sostanziale equilibrio tra la quantità di materiale eroso lungo le foci principali e quella depositata lungo i tratti di costa contigui, con un aumento complessivo di 167.500 m2 della superficie di spiaggia, imputabile soprattutto alla variazione positiva nel tratto a di 460.500 m2. i periodi successivi sono caratterizzati da una dominante tendenza all’erosione che comporta variazioni negative della spiaggia nei tratti a e c, valutabili in un totale di circa 715.500 m2 per il 1954-1992 e di circa 107.600 m2 per il 1992-1998, cui corrispondono tassi annuali molto simili di rispettivamente 18.800 e 17.900 m2/anno circa. per il tratto immediatamente a sud del porto di termoli si verifica tra il 1954 e 1998 (o verosimilmente 1980?-1998), una variazione positiva complessiva dell’arenile di circa 140.000 m2 di cui ca. 30.000 m2 nel solo periodo 19921998. complessivamente risulta che la costa molisana ha subito una variazione negativa delle spiagge di circa 656.000 m2 durante gli ultimi 90 anni (1907-1998). facendo un’analisi per tratti si evidenzia innanzitutto un bilancio positivo complessivo per il tratto b, negativo invece per i tratti a e c. questi ultimi mostrano un comportamento del tutto dissimile in relazione alla loro tendenza all’erosione, come evidenziano i valori medi annui calcolati rispettivamente per i periodi 19541992 e 1992-1998. infatti, nel tratti a tale tendenza subisce un incremento, avendosi il passaggio da un valore medio di 10.800 a 18.800 m2/anno, mentre subisce una diminuzione nel tratto c dove si passa da 9.100 a 5.700 m2/anno. il tratto b, invece, con un valore complessivo di 97.329 m2 evidenzia la sua leggera tendenza all’avanzamento, e mostra una crescente tendenza alla progradazione con un valore medio che da 1.100 passa a 6.600 m2/anno circa. i calcoli effettuati evidenziano anche che è il tratto a, e quindi l’area della foce del trigno, ad aver fornito i contributi annuali più consistenti alla variazione negativa delle spiagge per i suddetti periodi. emerge inoltre chiaramente, che le variazioni negative di spiaggia tra il 1907 e il 1998 lungo l’intero litorale molisano (655.640 m2) grosso modo coincidono con quelle verificatesi nello stesso periodo nel tratto c (690.649 m2), dato che le variazioni negative e positive nei tratti a e b quasi si compensano. prescindendo dal primo periodo (1907-1954) contrassegnato ancora da consistenti variazioni positive della spiaggia nel tratto a – si evidenzia chiaramente che sono proprio i tratti costieri a e c, dotati di importanti foci fluviali, ad essere stati interessati da variazioni negative della spiaggia, mentre il tratto b, ad essi interposto, trae evidenti benefici dall’erosione dei sedimenti nel tratto a e loro successivo trasporto lungo costa verso sud. 27 fig. 5 variazioni della linea di riva e dei principali canali fluviali nel periodo 1954-1992. tratti costieri che hanno subito 1) marcato arretramento, 2) leggero arretramento 3) marcata progradazione, 4) leggera progradazione. changes of shoreline and main fluvial channels from 1954 to 1992. coast sectors affected by 1) marked retreat, 2) slight retreat, 3) marked progradation, 4) slight progradation. ppeerriiooddoo ttrraattttoo aa ttrraattttoo bb ttrraattttoo cc ttoottaallee 1907 1954 460.500 17.000 310.000 167.500 1954 1992 409.863 40.830 346.461 715.494 1992 -1998 -112.957 39.499 34.188 107.646 totale 62.320 97.329 690.649 655.640 tab. 1 variazioni positive e negative (-) della superficie di spiaggia (in m2) analizzate per periodi e tratti. positive and negative (-) variations of the beach surface (in m2) analysed for periods and sectors. l’evoluzione recente ... 44.. ddiissccuussssiioonnee ddeeii ddaattii l’analisi cartografica comparativa ha evidenziato una serie di modificazioni significative della linea di costa che possono riferirsi a due principali fasi evolutive del sistema costiero esaminato. una prima fase di prevalente progradazione che si conclude con la costruzione degli apparati deltizi del trigno e del biferno rilevabili dalle carte storiche (atlante geografico del regno di napoli di rizzi-zannoni, 1808; cartografia storica i.g.m.i. del 1869 e 1907), e una seconda fase in cui si assiste ad un progressivo smantellamento degli stessi apparati deltizi e all’arretramento progressivo, tuttora in corso, delle spiagge. più in dettaglio, l’evoluzione più recente si può schematizzare come segue: periodo <1800? – 1869 gli apparati deltizi dei corsi d’acqua principali che sfociano lungo la costa molisana si mostrano con una morfologia pronunciata a cuspide, suggerendo un bilancio positivo complessivo del sistema costiero. nel 1869, detti apparati deltizi appaiono del tutto giovanili e in attiva evoluzione. periodo 1869-1907 in base a quanto è stato accertato per il tratto c, è possibile ipotizzare una fase di relativa stabilità delle aree di foce. in questo periodo, infatti, non si registrano variazioni negative della foce del biferno, mentre avviene una consistente progradazione delle fasce costiere contigue, portando ad un bilancio costiero altamente positivo. periodo 1907-1954 gli apparati deltizi del trigno e biferno sono soggetti a forte erosione che determina un cambiamento fondamentale della loro fisionomia passando da fluvialdominated a wave-dominated. questa fase è accompagnata da una ridistribuzione del materiale eroso che contribuisce alla progradazione degli adiacenti tratti di costa che compensa in parte (tratto c) o completamente (tratto a) l’erosione lungo le foci. il bilancio complessivo è positivo. periodo 1954-1992 si assiste ad una intensa fase di erosione che causa arretramenti consistenti nei tratti a e c dove si completa lo smantellamento dei residui apparati deltizi. il bilancio è chiaramente negativo. mentre la tendenza all’erosione lungo la costa è già molto evidente nel 1954, i corsi d’acqua principali a deflusso adriatico, caratterizzati da regimi torrentizi e morfologie d’alveo del tipo braided nelle sezioni non confinate, appaiono ad alta dinamicità, come evidenzia anche la presenza di conoidi attivi agli sbocchi di vari bacini tributari (aucelli & rosskopf, 2000). periodo 1992-1998 l’erosione della linea di costa persiste con ritmi diversi nei tratti a e c. per il tratto a si assiste ad un incremento delle variazioni areali negative, mentre si registra un rallentamento del ritmo di erosione nel tratto c. il tratto b è caratterizzato da una accresciuta tendenza alla progradazione, ma il bilancio complessivo è comunque negativo. l’evoluzione riscontrata corrisponde pienamente al modello proposto da pranzini (1989, 1994) sulla evoluzione dei delta italiani nel periodo storico in relazione alle tappe morfoevolutive più recenti. le modificazioni rilevate testimoniano variazioni consistenti nel bilancio costiero, quindi uno squilibrio tra quantità di sedimenti disponibili e capacità del sistema costiero di rielaborare gli stessi. le eventuali cause naturali e/o antropiche di tali modificazioni, in prima analisi, andrebbero ricercate 28 fig. 6 variazioni della linea di riva e dei principali canali fluviali nel periodo 1992-1998. tratti costieri che hanno subito 1) marcato arretramento, 2) leggero arretramento, 3) marcata progradazione, 4) leggera progradazione. changes of shoreline and main fluvial channels from 1992 to 1998. coast sectors affected by 1) marked retreat, 2) slight retreat, 3) marked progradation, 4) slight progradation. p.p.c. aucelli et al. nelle variazioni di uno o più dei seguenti principali parametri: apporti sedimentari alle foci, livello marino (sia a lungo che breve termine), capacità erosiva delle onde, caratteristiche dei sistemi di correnti vicino costa e delle modalità di trasporto lungo costa, nonché relative interferenze con strutture protettive. le conoscenze finora acquisite non consentono di proporre un’analisi esaustiva delle potenziali cause, data soprattutto la mancanza di dati relativi agli aspetti meteo-marini e la necessità di approfondire le modalità di interferenza tra dinamica costiera e strutture protettive. l’attenzione è stata quindi per ora focalizzata su quei aspetti che possono aver influito in modo diretto od indiretto sulla disponibilità di sedimenti da immettere nel bilancio costiero. e’, infatti, la risposta differenziata dei vari tratti costieri esaminati che vede “penalizzati” proprio i tratti costieri dotati di maggiori foci fluviali (tratti a e c) che, a nostro avviso, è fortemente indicativa del fatto che la diminuzione degli apporti fluviali alle foci costituisca effettivamente una delle cause principali se non proprio la causa maggiore delle tendenze all’arretramento osservate. variazioni climatiche le condizioni meteo-climatiche esercitano un importante ruolo sia in relazione alle caratteristiche idrologiche dei corsi d’acqua sia alla dinamica costiera, oltre a condizionare lo sviluppo della copertura del suolo. riguardo le prime, in particolare, è da considerare innanzitutto la stretta relazione tra afflussi meteorici e deflussi liquidi, e tra quest’ultimi e il trasporto solido. riguardo la prima fase evolutiva distinta, l’influenza climatica andrebbe a tradursi principalmente in una diminuzione delle temperature ed un aumento degli afflussi meteorici, e conseguente incremento delle portate liquide dei fiumi e del trasporto solido, quest’ultimo favorito o meno anche da un degrado della copertura vegetazionale. dati interessanti circa il rapporto tra condizioni climatiche, trasporto solido e evoluzione della linea di costa emergono dallo studio di marabini (2000) che permette una rivalutazione del ruolo del clima rispetto alle varie influenze antropiche (spesso le uniche ad essere chiamate in causa). i dati riportati, a sostegno dell’influenza climatica globale, mettono in evidenza gli andamenti simili delle portate dei maggiori fiumi d’europa negli stessi periodi, e il rapporto tra variazioni di portata dei corsi d’acqua e pulsazioni climatiche freddo-umide riferibili alla piccola età glaciale, con l’aumento degli apporti solidi alla costa e l’avanzamento progressivo della costa dell’alto adriatico tra il 1600 e 1820. ovviamente, per l’area e il periodo di studio presi in esame dovrebbero considerarsi soprattutto le pulsazioni fredde verificatesi nella seconda metà del 1800, evidenziate dall’avanzamento dei ghiacciai intorno al 1850 e 1890 (röthlisberger, 1986; antonioli, 2000). in accordo con marabini (2000), in un simile contesto climatico l’equilibrio della zona costiera è regolato dal rapporto tra apporti solidi e frequenza delle mareggiate, e il suo avanzamento legato quindi al “prevalere” degli apporti solidi. circa la seconda fase evolutiva è possibile fare riferimento ad una serie di dati di carattere sia nazionale che locale. come evidenziano i dati riportati in vittorini (1991) sulle variazioni delle portate liquide e solide dei fiumi italiani dal 1921 al 1973, emerge una netta flessione del trasporto torbido unitario del 40% circa confrontando il periodo pre-bellico (1921-1943/44) con quello post-bellico (1954-1973). tralasciando l’influenza antropica, tale flessione è da legare secondo l’autore, oltre che ad una complessiva diminuzione delle portate liquide (non del tutto da imputare al decremento degli afflussi meteorici), ad una diminuzione della frequenza di eventi di piena che superino una determinata portata. infatti, per quanto riguarda i corsi d’acqua maggiori sul territorio italiano sarebbero soprattutto gli eventi di piena con portate superiori ai 500 m3/s a portare ad una percentuale apprezzabile la frazione sabbiosa del carico solido. che non esista un rapporto semplice tra deflussi idrici, trasporto solido e fenomeni di progradazione od erosione costiera, viene indicato per l’area di studio per esempio dal fatto che, mentre le evidenze morfologiche relative al 1954 indicano per il sistema costiero una situazione di non-equilibrio (con fenomeni di arretramento già in atto), i sistemi fluviali sembrano ancora godere di condizioni di equilibrio nel loro assetto planoaltimetrico, e di alta dinamicità e capacità di trasporto (aucelli & rosskopf, 2000). ciò potrebbe essere indizio di un’accresciuta dinamica costiera, tale da annullare l’equilibrio precedentemente raggiunto. a livello regionale, l’analisi dei dati pluviometrici (ministero dei lavori pubblici, servizio idrografico, 1997) evidenziano per il quarantennio 1951-1990 un decremento generale delle precipitazioni. i dati pluviometrici e idrologici esaminati per il bacino del fiume trigno (aucelli, 1999; aucelli & rosskopf, 2000) mettono in evidenza uno stretto legame tra afflussi meteorologici e deflussi liquidi, nonché consistenti variazioni degli afflussi annuali nel tempo. complessivamente, tali dati confermano la tendenza a diminuire delle precipitazioni che caratterizza quasi per intero la seconda metà del secolo scorso. in particolare, condizioni di maggiore piovosità contraddistinguono i periodi 1944-1949 e 19551964, cui si contrappongono periodi più aridi tra il 19501954 e 1965-1990, con un ulteriore calo delle precipitazioni medie annue dal 1980 in poi. circa il rapporto tra recenti fluttuazioni climatiche e variazioni del livello marino, i dati esposti in antonioli (2000) riferiscono di una media dei valori di risalita eustatica di 12-15 cm/secolo per gli ultimi 100 anni, e di 1mm/anno durante il diciannovesimo secolo. questi dati, ovviamente da considerare con prudenza, suggeriscono la presenza di un leggero innalzamento del livello marino al termine della piccola età glaciale, valutabile fino ad oggi in qualche decimetro al massimo. un tale innalzamento, con ogni probabilità, ha influenzato negativamente l’equilibrio del sistema costiero, favorendo l’erosione della spiaggia. variazioni dell’uso del suolo spunti interessanti circa le possibili influenze delle variazioni dell’uso del suolo sulla dinamica fluviale e quindi su quella costiera, sono offerti dai dati raccolti da di martino (1996) sull’evoluzione della copertura forestale nella regione molise, già oggetto di esame in aucelli & rosskopf (2000). l’analisi di tali dati, infatti, mette in evidenza una serie di interventi da parte dell’uomo che, a partire dal 1800, hanno massicciamente modificato le originarie coperture boschive. tra questi interventi, i disboscamenti hanno interessato in modo 29l’evoluzione recente ... diffuso i bacini idrografici maggiori e minori e i versanti collinari costieri. il taglio della legna spesso avveniva in modo abusivo ed a dispetto della legge forestale del 1826. le modificazioni indotte dallo sfruttamento dei boschi per pascolo (spesso eccessivo) e dalle stesse attività di disboscamento hanno favorito l’impoverimento e il degrado del suolo e la sua asportazione da parte delle acque di ruscellamento. l’attività di disboscamento è perdurata fino all’inizio del 1900, ed è stata scarsamente bilanciata da misure di rimboschimento, effettive solo a partire dalla prima metà del 1900 in concomitanza degli interventi di bonifica. per il periodo 1920-1971, le analisi statistiche effettuate mostrano una riduzione delle aree coltivate, compensata soltanto in parte da un aumento del pascolo, delle coltivazioni arboree e del bosco. l’abbandono delle campagne potrebbe aver contribuito ad una riduzione dell’entità di erosione del suolo con lo stabilirsi di coperture perenne a seguito del processo di naturalizzazione. interventi antropici sui sistemi fluviali tra le attività umane che maggiormente incidono sui sistemi fluviali, le estrazioni in alveo rappresentano un aspetto di primaria importanza sia per il sistema fluviale del trigno, interessato da una consistente attività di estrazione soprattutto a partire dagli anni ’60 (aucelli & rosskopf, 2000), sia per quello del fiume biferno. per quest’ultimo, i prelievi in alveo hanno assunto maggiore consistenza a partire dalla seconda metà degli anni ’60 in concomitanza della costruzione in contemporaneo della strada che percorre il fondovalle del biferno (la fondovalle bifernina) e della diga di ponte liscione (1966-1976). con l’invaso del bacino artificiale nel 1977, le aree di fondovalle e soprattutto l’alveo hanno subito un progressivo degrado dovuto ad una modificazione consistente del naturale dinamismo del fiume a seguito della riduzione e regimazione delle sue portate liquide (rilascio costante di ca. 1 m3/sec) che ha portato ad una “fossilizzazione” delle morfologie d’alveo, ben evidente dal confronto delle più recenti foto-aeree (i.g.m.i. 1977 e 1991) e delle ortofotocarte (1998). attualmente, gli apporti solidi sabbiosi giungenti ancora alla foce provengono essenzialmente dal bacino del torrente cigno. questo, oltre ad essere il maggiore sottobacino del fiume biferno, è l’unico nel settore a valle della diga ad avere una estensione superiore a 50 km2 (ca. 107 km2), ed ad essere impostato in prevalenza su litologie sabbioso-ghiaiose. alle attività di prelievo si affiancano gli interventi di sistemazione dei corsi d’acqua principali, realizzati lungo il corso del trigno e del biferno durante l’ultimo trentennio circa. questi consistono principalmente nella realizzazione di arginature (presenti estesamente sul trigno dalla confluenza del torrente rivo in poi, e sul biferno nel tratto a valle della diga), e di armature dei tratti fluviali in corrispondenza di attraversamenti fluviali come ponti e viadotti lungo le strade di fondovalle (fondovalle trigno e biferno). le opere di arginatura sono state spesso accompagnate da interventi di rettificazione (come ad esempio il taglio del meandro nella parte terminale del biferno all’altezza dell’odierno nucleo industriale). interventi finalizzati a limitare l’erosione verticale come la messa in posto di briglie e traverse fluviali, hanno interessato in modo massiccio soprattutto i bacini tributari, contribuendo ad un ulteriore intrappolamento di sedimenti. 55.. ccoonnssiiddeerraazziioonnii ccoonncclluussiivvee il presente studio ha consentito di ricostruire le recenti variazioni della linea di costa lungo il litorale molisano. in particolare, questo studio ha evidenziato la tendenza, a partire dall’inizio del 1900, all’arretramento della costa che assume entità rilevanti soprattutto nella seconda metà del secolo scorso. circa le possibili cause di tali variazioni, i dati discussi precedentemente mettono in evidenza il possibile rapporto tra fenomeni di avanzamento e arretramento della linea di costa con modificazioni a breve termine delle condizioni climatiche. a queste, tuttavia, si sovrappongono modificazioni indotte dall’uomo (cambiamenti dell’uso del suolo, prelievo di inerti sui fiumi e sistemazioni idrauliche) che vanno a rinforzare se non a sostituire dal punto di vista dell’incidenza tali influenze climatiche. emerge inoltre chiaramente, che la conoscenza dei parametri meteomarini (direzione ed intensità dei venti, frequenza delle mareggiate, direzione del drift litoraneo) e delle caratteristiche topografiche dei fondali, è fondamentale per comprendere la tendenza evolutiva più recente ed attuale del sistema costiero, e l’interferenza tra il suo dinamismo e le opere di protezione costiera. l’analisi dei parametri meteo-marini, insieme a quelli meteo-climatici ed idrologici, portata indietro nel tempo per quanto possibile, potrebbe inoltre fornire ulteriori indicazioni utili circa il ruolo del clima nella dinamica costiera. bbiibblliiooggrraaffiiaa aminti p. & pranzini e. (a cura di) (1993) la difesa dei litorali in italia. edizioni delle autonomie, roma. p. 328. antonioli f. (a cura di) (2000) – le fluttuazioni del clima nel corso dell ’olocene: stato dell ’arte. i l quaternario, 1133 (1), 95-128. assessorato ai lavori pubblici della regione molise (2001) studio specialistico relativo alla erosione marina sulla intera costa della regione molise. campobasso. aucelli p.p.c. (1999) – analisi morfodinamica del bacino del fiume trigno: distribuzione, entità e cause dei fenomeni di alveo e di versante. dottorato di ricerca in scienze ambientali: uomo e ambiente. xii ciclo. università degli studi del molise, 306 pp. aucelli p.p.c. & rosskopf c. (2000) last century valley f loor modifications of the trigno river (southern italy): a preliminary report. geogr. fis. dinam. quat., 2233, 105-115. aucelli p.p.c., iannantuono e. & rosskopf c.m. (2004) – evolutive trends and present morphodynamics along the molise coast and their relationship to shore protection structures (southern italy). atti del convegno: 4th european congress on regional geoscientif ic cartography and information systems, bologna, giugno 2003 (in stampa). di martino p. (1996) – storia del paesaggio forestale del molise (sec. xix-xx). lampo, campobasso, 171 pp. 30 p.p.c. aucelli et al. giorgi g., girardi a., marabini f & zunica m. (1984) – evoluzione delle coste abruzzesi-molisane ed analisi di alcuni paraggi significativi. mem. soc. geol. it., 2277, 569-577. marabini f. (2000) – effetti sull’erosione costiera dei fenomeni climatici recenti: l’esempio del litorale nord adriatico. in: mare e cambiamenti globali. aspetti scientifici e gestione del territorio (a cura di sergio silenzi). convegno icram, 25/26 febbraio 1999, roma, 119-134. ministero dei lavori pubblici, servizio idrografico (1997) precipitazioni annue per il quarantennio 19511990: bacini con foce al litorale adriatico dal salinello al fortore. pubbl. n. 29 del servizio, fasc.1°, 72. parea g.c. (1978) trasporto dei sedimenti ed erosione costiera lungo il litorale fra il tronto ed il fortore (adriatico centrale). mem. soc. geol. it., 1199, 361-367. pranzini e. (1989) – a model for cuspate river delta erosion. 6th symposium on coastal and ocean management/asce. charleston, sc. coastal zone ’89, 4345-4357. pranzini e. (1994) – bilancio sedimentario ed evoluzione storica delle spiagge. il quaternario, 77 (1), 197204. rizzi-zannoni g.a. (1808) – atlante geografico del regno di napoli. röthlisberger f. (1986) – 10.000 jahre gletschergeschichte der erde. verlag sauerländer, 395 pp. vittorini s. (1991) – la diminuzione del trasporto torbido nei fiumi italiani tra il periodo prebellico e quello attuale. geogr. fis. dinam. quat., 1144, 252-258. zunica m. & girardi a. (1984) atlante delle spiagge italiane. cnr, selca, firenze. lavoro realizzato con il contributo dei fondi di ateneo 2000 (quota di co-finanziamento cofin 2002, responsabile nazionale giuliano rodolfi, responsabile scientif ico dell ’unita di ricerca carmen maria rosskopf). 31 ms. ricevuto il 20 dicembre 2003 testo definitivo ricevuto il 7 febbraio 2004 ms. received: december 20, 2003 final text received: february 7, 2004 l’evoluzione recente ... imp.carveni&controllo controllo tettonico sulla morfologia del basso versante nord-orientale dell’etna (sicilia) pietro carveni1, santo benfatto2, rosanna maniscalco1, maria salleo3 & giovanni sturiale1 1università di catania, dipartimento di scienze geologiche, corso italia 55, 95129 catania, italia; e-mail: carveni@unict.it 2geologo, libero professionista, via san marco 91, 95047 paternò, catania, italia. 3naturalista, via san marco 91, 95047 paternò, catania, italia. riassunto: carveni p., benfatto s., maniscalco r., salleo m. & sturiale g., controllo tettonico sulla morfologia del basso versante nord-orientale dell’etna (sicilia). (it issn 0394-3356, 2005). sulla base di uno studio di fotografie aeree, di un’analisi cartografica e di rilievi geologici e geomorfologici di dettaglio, viene studiato il basso versante nord-orientale dell’edificio vulcanico etneo, nel tratto compreso tra capo schisò e la foce del torrente macchia. si riscontra che l’attività di un sistema di faglie, sinora non descritto in letteratura, ha esercitato una profonda influenza sulla topografia, sulla rete idrografica, sull’andamento della linea di costa e, presumibilmente, sulla dislocazione di alcuni delta subacquei; due faglie hanno formato un graben che ha deviato il fiume alcantara; una colata lavica, riversandosi lungo la valle fluviale, ha fossilizzato questo graben; altre faglie hanno sbarrato piccoli corsi d’acqua con conseguente formazione di stagni costieri; dall’analisi delle carte nautiche si ipotizza che parte dei delta subacquei dei corsi d’acqua drenanti la zona abbia subito uno scorrimento destro valutabile in 500 metri. dall’analisi dei cataloghi dei terremoti non risulta alcuna attività sismica, in tempi storici, collegabile a questo sistema di faglie; altre fonti descrivono una sismicità locale legata alla riattivazione, nel dicembre 1795 e nel marzo 1847, del vulcano di fango noto come “salsa di fondachello”, e alla sua distruzione avvenuta nel mese di aprile dello stesso anno. attualmente l’unica manifestazione di attività endogena si limita all’emissione di metano in corrispondenza di un canale di drenaggio. abstract: carveni p., benfatto s., maniscalco r., salleo m. & sturiale g., tectonic control on the morfology of the northeastern lower slope of mount etna volcano (sicily). (it issn 0394-3356, 2005). mount etna lies in a structurally highly complex setting, close to the boundary between the malta-hyblean platform and the ionian basin and at the intersection of the malta escarpment and the messina-giardini fault zone. thus, volcanism and tectonics at etna are clearly interacting and exerting a strong control on morphology. the studied area is located on the lower eastern slope of mount etna between capo schisò and macchia stream mouth. the study consisted of stereopairs and cartographic analyses supported by geological and geomorphological surveys. we recognize the system of faults giardini mascali (draws southern of the messina fiumefreddo system), which intersects the low north-eastern slope of the volcanic building of mount etna. it is an active fault systems ne-sw and nne-ssw trending, bounding horsts and grabens which influence river courses and submarine delta deposition. in particular, we analyse the course of alcantara river, which is deviated from its original nw-se trend to a nne-ssw one along a graben. the graben is later filled with lava flow and subsequently the lava fill eroded for rejuvenation of the river due to the uplift of the area. has been hypothesized a succession of tectonic events in the area of the mouths of the alcantara river that has brought to the actual geomorfological framework. from the analysis of earthquakes catalogues, a complete lack of historical seismic events attributable to the activity of the system of faults giardini – mascali is underlined; the attributable seismic events to this system are those related to the reactivation in 1795 december and in 1847 march of the mud volcano known with the name “salsa di fondachello” and to the sinking of the same one, happened in 1847 april. ch4 uprising gas activity is located along a fault with associated seismicity. parole chiave: basso versante nord-orientale dell’etna, tettonica, attività vulcanica, geomorfologia. keywords: low north-eastern slope of mt. etna volcano, tectonics, volcanic activity, geomorfology. il quaternario italian journal of quaternary sciences 18(2), 2005 57-68 1. introduzione il territorio siciliano, come la maggior parte di quello nazionale, è interessato da un’intensa attività tettonica che si manifesta con deformazioni della crosta terrestre; lungo le coste queste possono provocare variazioni relative del livello marino, riconoscibili per l’esistenza di tracce geologiche (depositi di spiaggia sollevati) e/o geomorfologiche (spianate d’erosione marina sollevate, solchi di battente sollevati o sommersi); nell’entroterra i movimenti tettonici si risolvono spesso in scarpate di faglia che condizionano la rete fluviale, dando luogo, nei casi più comuni, a cascate, laghi di sbarramento e fenomeni di cattura. la presente nota si inserisce in una ricerca sulle variazioni geomorfologiche indotte da movimenti tettonici sul basso versante nord-orientale dell'edificio vulcanico etneo; lo studio è basato su rilievi geologici e geomorfologici di dettaglio, sull’analisi di fotografie aeree e della cartografia esistente. in letteratura sono reperibili molti lavori che descrivono le strutture tettoniche affioranti lungo il basso versante orientale etneo; esse assumono una particolare evidenza morfologica nell’area compresa tra sant’alfio a settentrione e acireale a meridione (fig. 2). al contrario, la letteratura è carente nello studio delle adiacenti zone, poste a settentrione, tra mascali e giardini, dove le evidenze morfologiche sono meno chiare. il riconoscimento delle strutture in quest’area è stato reso possibile principalmente attraverso lo studio del reticolo idrografico e della linea di costa. 58 p. carveni et al. 2. quadro geologico dell’area etnea la zona in studio è ubicata nel settore nord-orientale del monte etna, al confine con i monti peloritani. il monte etna, con la sua altitudine di poco superiore a 3.300 metri e un diametro massimo di 44 chilometri, è il più grande vulcano attivo del continente europeo. esso è uno stratovulcano complesso, risultante dalla sovrapposizione di diversi edifici (gemmellaro, 1858; lyell, 1859) poggianti su un basamento in parte alloctono, formato da rocce di età compresa tra il cretaceo ed il pleistocene (cristofolini et al., 1979; romano et al., 1979; lentini, 1982). il bacino del mediterraneo centrale, nel quale si inserisce l’etna, è caratterizzato da differenti domini strutturali, la cui genesi è da inquadrare nel contesto collisionale tra la placca africana e la placca europea; le due masse continentali si scontrano e si saldano tra loro, originando l’orogene appenninico – maghrebide, una catena corrugata che forma la dorsale appenninica e, attraversando l’arco calabro, la sicilia e il canale di sicilia, prosegue lungo le coste nord-africane del maghreb. l’edificio vulcanico etneo sorge al limite tra diversi domini strutturali della sicilia orientale, dove la crosta oceanica ionica e la crosta continentale dell’avampaese ibleo si immergono sotto i l fronte dell’orogene appenninico-maghrebide (finetti et al., 1996) (fig. 1). l’avampaese ibleo costituisce il margine della placca africana (burollet et al., 1978), zona considerata stabile verso cui convergono le falde neogeniche dell’orogene appenninico-maghrebide. esso è costituito da una potente successione prevalentemente carbonatica compresa, con lacune stratigrafiche, tra il trias e il pleistocene medio; vi si intercalano prodotti effusivi basici cretacei, miocenici e plio-pleistocenici, la cui risalita è stata favorita da intense fasi tettoniche distensive (cristofolini, 1966; di grande, 1967; 1969; 1972; patacca et al., 1979; carbone et al., 1982 c; lentini et al., 1986; carbone et al., 1987; carveni et al., 1991 a; 1991 b; 1993; carveni & sturiale, 1999). esso confina ad oriente con la crosta oceanica del bacino ionico (finetti, 1982) tramite la scarpata ibleo-maltese, di origine tettonica (finetti & morelli, 1972), originata da un sistema di faglie normali a gradinata, il cui prolungamento verso settentrione interseca il fianco orientale dell’edificio etneo (cristofolini et al., 1979; ghisetti, 1979; lentini, 1982; lo giudice et al., 1982; carbone et al., 1982 a; 1982 b); la scarpata si sarebbe formata in un’unica grande fase tortoniana, con minori riattivazioni posteriormente al deposito degli infrapliocenici trubi, e a luoghi le sono connesse importanti attività vulcaniche (casero et al., 1984). lanzafame & bousquet (1997) ritengono che la scarpata ibleomaltese sia un segmento di un importante sistema di faglie con direzione compresa tra nnw-sse e nw-se, che attraversando la sicilia nord-orientale e il mar tirreno meridionale, raggiunge vulcano, lipari e salina. le unità della catena kabilo-calabride, costituita da falde di basamento cristallino interessate da metamorfismo ercinico con resti dell’originaria copertura sedimentaria meso-cenozoica, sono sovrascorse sulle unità della catena appenninico-maghrebide, in concomitanza dell’apertura del bacino balearico–provenzale e la rotazione del blocco sardo–corso (de jong et al., 1973; dewey et al., 1989). la catena appenninico–maghrebide è costituita da falde sud-vergenti, il cui corrugamento ha interessato, deformandole, le coperture sedimentarie della tetide e dei paleodomini minori ad essa associati, originariamente posti tra il margine della placca europea e il margine della placca africana (finetti et al., 1996). ad iniziare dal pleistocene inferiore intense fasi tettoniche hanno causato un’elevata distorsione al margine settentrionale della placca africana, a causa della differente velocità con cui avviene la subduzione al di sotto della catena appenninico-maghrebide (van bemmelen, 1969; morelli, 1970; selli & fabbri, 1971; giese & morelli, 1975), e ciò ha determinato uno sti-ramento crostale che ha dato luogo a fratture con direzione nwse, ne-sw ed e-w (ghisetti & vezzani, 1982; scandone, 1982); all’intersezione di tali strutture si è formata una zona di debolezza attraverso la quale avviene la risalita di magmi sub-crustali (frazzetta & villari, 1981). sulla genesi del vulcano e sul quadro strutturale sono stati proposti numerosi modelli: 1) intersezione di importanti lineamenti strutturali come la scarpata ibleo-maltese e l’allineamento messinagiardini (ogniben et al., 1975; mcguire et al., 1997); 2) tettonica estensionale che ha portato alla formazione di un graben nell’area dell’attuale piana di catania (di geronimo et al., 1978); 3) processi di rifting tra il blocco maltese-siciliano e il bacino ionico (gillot et al., 1994, continisio et al., 1997); 4) deformazione al footwall di una faglia normale appartenente al sistema distensivo siculo-calabro ad andamento wnw-ese (monaco et al., 1997); 5) risalita magmatica mantellica causata dalla presenza di un hot spot (tanguy et al., 1997); 6) roll-back di una porzione di litosfera subdotta al di fig. 1 schema strutturale della sicilia (da finetti et al., 1996). ai) avampaese ibleo; cam) catena appenninico-maghrebide; ckc) catena kabilo-calabride; cs) catena sicana; e) edificio vulcanico etneo; sim) scarpata ibleo-maltese; smf) sistema messina – fiumefreddo; il quadrato indicato dalla freccia corrisponde alla zona in studio. structural scheme of sicily (after finetti et al., 1996). ai) iblean foreland; cam) apenninic-maghrebian chain; ckc) kabilocalabrian chain; cs) sicana chain; e) mount etna volcano; sim) hyblean-malta escarpment; smf) fault system messina – fiumefreddo; narrow indicates position of studied area. sotto del mar tirreno (gvirtzman & nur, 1999). l’attività eruttiva dell’etna, inizialmente sottomarina e fissurale, è diventata in seguito subaerea ed a carattere centrale, a causa di un sollevamento regionale, tutt’ora in atto, che ha determinato una variazione nel meccanismo di risalita dei magmi, con conseguente cambiamento del chimismo, da prodotti subalcalini a prodotti più o meno differenziati della serie alcalinosodica, emessi da numerosi apparati eruttivi e raggruppati in quattro unità vulcano-stratigrafiche: centri alcalini antichi, trifoglietto s.l., mongibello antico e mongibello recente (romano, 1982). sulla base di datazioni radiometriche del rapporto k/ar, gillot et al. (1994) hanno distinto quattro periodi di attività dell’etna, ai quali si alternano lunghi periodi di quiescenza: il primo periodo (da 520.000 ± 40.000 a 270.000 anni fa) è caratterizzato da vulcanismo tholeiitico, con fasi eruttive separate da lunghi periodi di quiescenza; il secondo periodo (da 168.000 ± 8.000 a 100.000 anni fa) è evidenziato da un radicale cambiamento del tipo di attività (strato-vulcani al posto di fessure eruttive) e del chimismo dei prodotti (da sub-alcalini ad alcalini); durante il terzo periodo (tra 80.000 e 60.000 anni fa) si formò un grande complesso vulcanico poligenico (unità del trifoglietto); il quarto periodo (da 35.000 anni fa ad oggi) corrisponde allo sviluppo di un grande strato-vulcano, il mongibello; un’importante fase, caratterizzata da eruzioni pliniane e idromagmatiche, permette di suddividere questo periodo in due parti: mongibello antico e mongibello recente. 3. assetto strutturale del versante orientale etneo carapezza (1962), nel tentativo di determinare una relazione tra la tettonica regionale e le zone di minore resistenza dell’etna, identifica un rift lungo il fianco orientale dell’edificio vulcanico. marchesini et al. (1964) riconoscono quattro principali allineamenti tettonici, con direzioni n-s, enewsw, ne-sw e nw-se. frazzetta & romano (1978) identificano due allineamenti alimentatori preferenziali per le aree ad alta probabilità di eruzioni: una nel settore circolare compreso tra ne-sw e ene-wsw, la seconda con direzione nnw-sse. lo giudice et al. (1982) riconoscono nell'area etnea e nelle zone circostanti varie direttrici di faglie: le più importanti hanno direzione n 60° e, n 30° e, n 15° w e n 60° w. kieffer (1983 a; 1983 b) ipotizza scivolamenti gravitativi di parte del versante orientale dell’edificio vulcanico, ed attribuisce il fenomeno alla ripetuta intrusione di magma attraverso un “rift di ne” e un rift meridionale. l’ipotesi di uno scivolamento gravitativo viene ripresa da azzaro et al. (1989) e da neri et al. (1991). borgia et al. (1992), sulla base dei risultati ottenuti da ferrari et al. (1991) sui dicchi affioranti nella valle del bove, ipotizzano uno spreading radiale del substrato dell’etna verso se. lo giudice & rasà (1992) ritengono invece che si tratti di movimenti puramente gravitativi, che provocano lo scivolamento verso sse della porzione dell’edificio 59controllo tettonico ... etneo delimitata a settentrione dalla faglia della pernicana e dal rift di ne, e a se dalle faglie di mascalucia e trecastagni (fig. 2). la documentazione storica sui terremoti avvenuti sul basso versante orientale etneo negli ultimi due secoli e le conseguenze morfologiche dei movimenti tettonici sono analizzate in una serie di articoli (adorni & carveni 1993 a; 1993 b; carveni & bella, 1994; bella et al., 1996; carveni et al., 1996; 1997; gresta et al., 1997). dall’analisi dei sistemi di faglie che nel pleistocene sono stati attivi in sicilia orientale, sulla base di informazioni geologico-strutturali e morfologiche e dell’analisi di sezioni sismiche a mare, monaco & tortorici (1995) e monaco et al. (1995; 1997) distinguono un “sistema acireale – sant’alfio” (faglie normali con componente trascorrente destra nnw-sse) e un “sistema di piedimonte” (faglie normali e fratture d’estensione nne-ssw); entrambi i sistemi, associati ad un’estensione wnw-ese, formano scarpate di età suprapleistocenico-olocenica, le quali esercitano un controllo sulla topografia e sul reticolo idrografico. ricerche basate su rilievi effettuati da satelliti (gironi, 2003) evidenziano un sollevamento in atto di tutta la zona etnea con punte massime di 15 mm/anno, con eccezione del settore circolare delimitato a settentrione dalla faglia della pernicana e sua prosecuzione verso oriente, e a sw dalle faglie di mascalucia e trecastagni: questa zona risulta essere interessata da un fenomeno di abbassamento con un tasso massimo di circa 15 mm/anno a stazzo, frazione di acireale, dove un molo costruito nel 1949 e alto circa 1 metro, attualmente si trova al livello del mare (figg. 2 e 3). 4. lineamenti geologici dell’area l’area in esame è ubicata lungo il margine nordorientale del monte etna, tra la valle del fiume alcantara a settentrione e la foce del torrente macchia a meridione. il substrato dell’etna nell’area studiata è costituito da successioni della catena appenninico–maghrebide, mentre le successioni della catena kabilo–calabride affiorano più a settentrione, fuori dall’area in studio. l’unità strutturalmente più bassa è data da depositi argilloso-arenaceo-conglomeratici alimentati dalle unità cristalline calabridi, noti il letteratura come formazione piedimonte, (fig. 4: 12) di età rupeliana (lentini et al., 2000); essi affiorano lungo il versante destro della valle dell’alcantara. segue il flysch di capo d’orlando (fig. 4: 11), formazione terrigena dell’oligocene superiore–burdigaliano inferiore, il quale poggia in discordanza al tetto delle unità cristall ine della catena kabilocalabride, suturandone i relativi contatti tettonici; esso è costituito da facies torbiditiche conglomeratico-arenacee evolventi verso l’alto e lateralmente a facies arenacee o arenaceo-pelitiche; i conglomerati sono stati interpretati da guerrera & wezel (1974) come depositi di base di scarpate che precedono l’arrivo di torbiditi arenacee; la facies arenacea è ben rappresentata lungo la valle del fiume alcantara. in contatto tettonico sul flysch di capo d’orlando affiorano le argille scagliose antisicilidi (fig. 4: 10); 60 fig. 2 ubicazione dell'area in studio, in rapporto alle più importanti strutture tettoniche del versante orientale dell'etna. faglie: fcm) faglia capo schisò – foce del torrente macchia; ff) faglia di fondachello; fg) faglia di giardini; fm) faglia di moscarello; fma) faglia di mascalucia; fms) faglia macchia – stazzo; fn) faglia di naxos; fp) faglia della pernicana; fpvc) faglia praiola – villa calanna; frn) faglia della ripa della naca; frp) faglia della ripa di piscio; fsl) faglia di san leonardello; ft) faglia di trecastagni; ftm) faglia del torrente minisale; sp) sistema di piedimonte. centri abitati: a) acireale; fi) fiumefreddo; fo) fondachello; g) giardini; ma) mascali; m) mascalucia; s) stazzo; sa) sant’alfio; t) trecastagni. cc) cratere centrale; rne) rift di ne. i triangoli indicano zone in cui sono stati misurati sollevamenti e abbassamenti fino a 15 mm/a., (gironi, 2003). location of studied area in the frame of the main tectonic structures of eastern flank of mt. etna volcano: fcm) cape schisò –macchia stream mouth fault; ff)) fondachello fault; fg) giardini fault; fm) moscarello fault; fma) mascalucia fault; fms) macchia – stazzo fault; fn) naxos fault; fp) pernicana fault; fpvc) praiola – villa calanna fault; frn) ripa della naca fault; frp) ripa di piscio fault; fsl) san leonardello fault; ft) trecastagni fault; sp) piedimonte system. towns: a) acireale; fi) fiumefreddo; fo) fondachello; g) giardini; m) mascalucia; ma) mascali; s) stazzo; sa) sant’alfio; t) trecastagni. cc) central crater; rne) ne rift. triangles indicate 15 mm/y uplift or lowering zones up to 15 mm/y (after gironi, 2003). p. carveni et al. 61 ogniben (1960) definì queste argille come complesso sud-liguride, considerandole identiche a quelle del complesso sicilide, ipotizzandone una provenienza dall’area occupata dalle argil le variegate del complesso sicilide per fenomeni di “retrocolamento gravitativo” sulla copertura tardorogena del complesso calabride; lentini et al. (1987) attribuiscono alla formazione un’età cretacea. depositi tardo miocenici costituiti da marne argillose grigie con intercalazioni di arenarie (tortoniano) passanti verso l’alto a gessi della serie evaporitica siciliana (messiniano) affiorano in piccoli lembi lungo la valle del fiume alcantara (fig. 4: 9). argille marnose azzurre di età infrapleistocenica (fig. 4: 8) affiorano in un horst allungato in senso nesw a settentrione di fondachello, delimitato a occidente dalla faglia di naxos (fig. 4: b) e a oriente dalla faglia di case decime (fig. 4: g). calcareniti medio-pleistoceniche a briozoi affiorano sui fianchi della collinetta di serra san biagio, a ne di fiumefreddo di sicilia; si tratta di calcareniti giallobrune in banchi di spessore massimo di 2 metri, con spessore in affioramento di circa 30 metri (fig. 4: 7). piroclastiti dell’unità del trifoglietto affiorano nella parte sud-occidentale della zona cartografata (fig. 4: 6). seguono alcune colate laviche provenienti dai centri eruttivi dell’ellittico e del leone (romano, 1982), (fig. 4: 5), colate laviche del mongibello recente, tra le quali riveste una particolare importanza la colata lavica di capo schisò (fig. 4: 4), la colata lavica del 1651 (fig. 4: 3), e la colata lavica del 1928 (fig. 4: 2). alluvioni e depositi di spiaggia attuali (fig. 4: 1) chiudono la serie stratigrafica. 5. dati morfotettonici l’analisi morfologica ha evidenziato l’esistenza di un sistema di faglie dirette, il sistema giardini – mascali (figg. 2, 4 e 5), con sviluppo lineare di quasi 12 chilometri, che dà luogo ad una serie di graben e horst, con direzione ne-sw nella parte più settentrionale, tendente a nne-ssw in quella meridionale. le faglie rigettano formazioni sedimentarie e vulcaniche comprese tra il pleistocene inferiore-medio ed il recente. finora questo sistema di faglie non è stato segnalato in letteratura, malgrado la sua attività abbia esercitato un’intensa influenza sul reticolo idrografico, sull’andamento della linea di costa e presumibilmente su depositi di delta sottomarini; il mancato riconoscimento può essere giustificato dal fatto che la formazione geologica predominante in affioramento è data da alluvioni recenti e attuali, costituite prevalentemente da ghiaie sabbiose, e dal fatto che la zona è intensamente coltivata, per cui eventuali scarpate di faglia vengono velocemente smantellate sia dall’erosione, sia dall’azione antropica. le faglie riconosciute sono: 1) faglia di giardini (figg. 4 e 5: a): direzione n 60° e nel tratto settentrionale, n 35° e in quello meridionale, immersione a se; essa disloca le calcareniti medio-pleistoceniche di serra san biagio, alcune colate laviche attribuite ai centri eruttivi dell’ellittico (romano et al., 1979) e alluvioni recenti; il rigetto verticale in corrispondenza di serra s. biagio è valutabile in almeno 50 metri; 2) faglia di naxos (figg. 4 e 5: b): antitetica alla precedente, ha direzione n 56° e nella sua porzione settentrionale, n 32° e a meridione, immersione a nw; questa faglia disloca argille marnose azzurre inframedio-pleistoceniche pre-etnee e alluvioni recenti. 3) faglia di fondachello (figg. 4 e 5: c): direzione n 35° e, labbro ribassato a nw; essa è evidenziata da un lungo dosso rettilineo che separa la pianura alluvionale dalla spiaggia attuale; è da escludesi che questa scarpata sia una morfologia di tipo eolico, sia in base all’andamento rettilineo presentato, sia in base alla granulometria dei sedimenti, formati da ciottoli e sabbia grossa (amore et al., 1992). 4) faglia capo schisò foce del torrente macchia (figg. 4 e 5: d): con direzione n 45° e nel segmento settentrionale, e n 33° e in quello meridionale, pendenza a se, questa faglia viene ipotizzata in base all’andamento rettilineo della linea di costa e al forte gradiente delle isobate. 5) faglia di case decime (figg. 4 e 5: g): è stata riconosciuta in base a considerazioni stratigrafiche poiché essa mette a contatto le argille quaternarie con le alluvioni recenti; dati inediti relativi a pozzi per uso irriguo evidenziano l’esistenza del substrato argilloso a profondità comprese tra 10 e 15 metri. il sistema giardini – mascali è intersecato lungo la valle del torrente minissale da una faglia normale con componente orizzontale destra e rigetto verticale valutabile in almeno 60 metri (faglia del torrente minissale, figg. 4 e 5: e), e a meridione di fiumefreddo dalla faglia della pernicana, diretta con componente orizzontale sinistra ed attività sismica accertata (figg. 4 e 5: f). la faglia di giardini e la faglia di naxos hanno giocato un ruolo determinante sull’assetto geomorfologico della zona: esse infatti formano il graben capo schisò – mascali, con direzione ne-sw, che ha deviato il tratto terminale del fiume alcantara (fig. 6 a e 6 b); per un certo periodo le alluvioni di questo fiume si sono riversate nella parte meridionale dell’attuale baia di giardini: l’andamento delle isobate in corrispondenza di capo schisò (istituto idrografico della marina, 2001), che corrisponde a questa ipotizzata vecchia foce dell’alcantara, mostra chiaramente l’esistenza di una morfologia attribuibile ad un delta almeno fino a 200 fig. 3 il molo nuovo e il molo vecchio di stazzo. new and old docks in stazzo port. controllo tettonico ... 62 fig. 4 schema geologico: 1 ) alluvioni e depositi di spiaggia recenti ed attuali; 2) colata lavica del 1928; 3) colata lavica del 1651; 4) colata lavica di capo schisò: αα) tratto nord-orientale; ββ) lobo sud-occidentale; 5) colate laviche dei centri eruttivi dell’ellittico e del leone; 6) piroclastiti dell’unità del trifoglietto; 7) calcareniti medio-pleistoceniche a briozoi; 8) argille marnose azzurre infrapleistoceniche; 9) marne argillose grigie con intercalazioni arenacee (tortoniano) con gessi (messiniano) alla sommità; 10) argille scagliose antisici l idi; 11 ) flysch di capo d’orlando; 12) formazione piedimonte; a) faglia di giardini; b) faglia di naxos; c) faglia di fondachello; d) faglia capo schisò – foce del torrente macchia; e ) faglia del torrente minissale; f) faglia della pernicana; g) faglia di case decime. geological scheme of mt. etna low northeastern slope: 1) present day alluvium and shoreline deposits; 2) 1928 lava flow; 3) 1651 lava flow; 4) capo schisò lava flow: αα) ne flow; ββ) sw bend; 5) lavas from the eruptive centres of ellittico and leone; 6) tephra from the eruptive centres of trifoglietto; 7) middle pleistocene calcarenites with briozoa; 8) lowpleistocene bluish marly clays; 9) grey silty clays with arenaceous intercalations (tortonian) with gypsum (messinian) on the top; 10) antisicilidi varicoloured clays; 11) capo d’orlando flysch; 12 ) piedimonte formation. a) giardini fault; b) naxos fault; c) fondachello fault; d) cape schisò – macchia stream mouth fault; e) minissale stream fault; f) pernicana fault; g) case decime fault. p. carveni et al. 63 fig. 5 schema morfologico: a) faglia di giardini; b) faglia di naxos; c) faglia di fondachello; d) faglia capo schisò – foce del torrente macchia; e) faglia del torrente minis-sale; f) faglia della pernicana; g) faglia di case decime. 1) presunto delta subacqueo del fiume alcantara, formatosi posteriormente alla deviazione tettonica; 2) attuale delta subacqueo del torrente santa venera; 3) presunto vecchio delta subacqueo del torrente santa venera; 4) attuale delta subacqueo del fiume alcantara; 5) presunto vecchio delta subacqueo del fiume alcantara; 6 ) attuale delta subacqueo del torrente minissale; 7) presunto vecchio delta subacqueo del torrente minissale; 8 ) delta subacqueo di incerta attribuzione; αα ) tratto della colata lavica che scorrendo lungo il fiume alcantara ha formato capo schisò; ββ) lobo sud-occidentale della colata lavica del fiume alcantara; γγ) deviazione del torrente fiumefreddo causata dalla faglia di naxos; δδ) deviazione del torrente fiumefreddo causata dalla faglia di fondachello; εε) gurna di fondachello; ζζ) acquitrino di anguillara. morphological scheme: a ) giardini fault; b) naxos fault; c) fondachello fault; d ) cape schisò macchia stream mouth fault; e) minissale stream fault; f ) pernicana fault; g ) case decime fault. 1) hypothetical alcantara river submarine delta, after tectonin ri-ver piracy; 2) actual santa venera stream delta; 3 ) hypothetical santa venera stream old delta; 4 ) alcantara river delta; 5 ) hypothetical alcantara river old delta; 6) minissale stream delta; 7) hypothetical minissale stream old delta; 8) uncertain attribution delta; αα ) lava flow forming schisò cape; ββ) sw part of lava flow; γγ) stream fiumefreddo deviation caused by naxos fault; δδ) stream fiumefreddo deviation caused by fondachello fault; εε) quagmire gurna di fonda-chello; ζζ ) anguil lara quagmire. controllo tettonico ... metri di profondità (fig. 5: 1); l’arrivo di una colata lavica lungo la valle dell’alcantara ha fossilizzato il graben (fig. 6 c), evidenziandolo sia verso ne, dove raggiungendo la costa ha formato la scogliera di capo schisò (figg. 4 e 5: αα), sia verso sw, con l’ampio lobo rivolto in questa direzione, forse in corrispondenza dell’ansa di un meandro preesistente ai movimenti tettonici (figg. 4 e 5: ββ); in seguito l’alcantara ha eroso la colata, andando a sfociare approssimativamente nella stessa zona occupata prima della deviazione di origine tettonica (fig. 6 d): dall’analisi delle carte nautiche (istituto idrografico della marina, 2001) il delta subacqueo relativo all’attuale foce è riconoscibile fino all’isobata –100 metri (fig. 5: 4). oltre a questa importante deviazione del fiume alcantara, la faglia di naxos provoca una deviazione verso ne del torrente fiumefreddo (fig. 5: γγ). l’esistenza della faglia di fondachello era già stata ipotizzata da mercurio (1847), il quale notava che la morfoscultura poteva essere seguita agevolmente dalla spiaggia di riposto a capo schisò; oggi la scarpata di faglia è certamente molto meno evidente, a causa dell’erosione e dell’azione antropica; questa faglia condiziona il tratto terminale del torrente fiumefreddo (fig. 5: δδ) costringendolo a compiere una deviazione verso sw; inoltre, sbarrando alcuni piccoli corsi d’acqua, ha creato le condizioni per la nascita di alcuni stagni costieri: lo stagno conosciuto come gurna di fondachello (fig. 5: εε) (gurna = vasca d’acqua, dal greco moderno γουρνα, giarrizzo, 1989), un secondo stagno che, in base ad alcune carte topografiche del xix secolo si trovava a circa mezzo chilometro di distanza verso sse in località ausini, e del quale non si conservano tracce a causa dell’industrializzazione della zona, e un terzo ancora più a meridione, in contrada anguillara (fig. 5: ζζ). la formazione di uno stagno costiero viene generalmente attribuita all’accumulo di sabbie e/o ghiaie in un tratto di mare poco profondo in corrispondenza di una baia; se l’accumulo evolve da barra subacquea a tombolo, l’insenatura, ormai separata dal mare, si trasforma in lago costiero; la formazione di un tombolo può verificarsi anche lungo una costa rettilinea, se il moto ondoso ha la competenza per spostare ingenti quantità di material i detritici deposti lungo le foci fluviali o erosi direttamente dal mare lungo la costa. l’analisi della carta nautica dell’area (istituto idrografico della marina, 2001) evidenzia che la profondità del mare aumenta rapidamente con la distanza dalla linea di costa, quindi non è possibile addebitare la formazione dei bacini costieri all’evoluzione da barra subacquea a tombolo; si ipotizza quindi che la genesi della gurna di fondachello e delle zone acquitrinose di ausini e di anguillara sia dovuta all’attività della faglia di fondachello, che ha formato il lungo dosso rettilineo che separa la spiaggia attuale dalla pianura costiera. la faglia capo schisò foce del torrente macchia è stata ipotizzata, principalmente, sulla base dell’andamento rettilineo della linea di costa e del forte gradiente tra le isobate; inoltre, dati di letteratura (monaco & tortorici, 1995) evidenziano la presenza di faglie obliquo-destre appartenenti al sistema messinagiardini, alle quali può essere collegata la faglia qui ipotizzata, la quale presenta identica orientazione e trascorrenza destra; i dati inediti circa l’esistenza del movimento della faglia capo schisò-foce del torrente macchia riguardano l’interazione tra il movimento della faglia in oggetto e l’attuale assetto di alcuni delta subacquei: a) in corrispondenza dell’attuale foce del torrente santa venera si trova una morfologia assimilabile ad un delta subacqueo fino alla profondità di –30 metri (fig. 5: 2); a se di questo ipotizzato delta, se ne trova un altro, riconoscibile fino all’isobata, –200 metri (fig. 5: 3); b) dalla morfologia presentata dalle isobate in corrispondenza dell’attuale foce dell’alcantara si riconosce un delta subacqueo fino all’isobata –100 metri 64 fig. 6 evoluzione morfologica della foce del fiume alcantara. morphological evolution of alcantara river mouth. p. carveni et al. (fig. 5: 4), ed un delta di maggiori dimensioni, fino all’isobata –200 metri, più a se (fig. 5: 5); c) l’attuale delta subacqueo del torrente minissale è rimarcato dall’andamento dell’isobata –20 metri (fig. 5: 6); è riconoscibile un altro delta subacqueo, fino a –200 metri, spostato verso sw di circa 500 metri (fig. 5: 7); d) poco più a sw dell’attuale foce del torrente delle forche è chiaramente riconoscibile un delta subacqueo nella forma dell’isobata –200 (fig. 5: 8); allo stato attuale delle conoscenze non è chiaro quale possa essere il fiume relativo a questa ultima morfologia; si può ipotizzare l’esistenza di un corso d’acqua lungo la cui valle sono scese una o più colate laviche, affioranti nella zona di fiumefreddo, le quali, riempiendo le valli e fossilizzandole, hanno causato la scomparsa dalla superficie dei corsi d’acqua, i quali continuano a scorrere, presumibilmente, in subalveo. 6. la sismicità locale l’analisi dei cataloghi dei terremoti evidenzia una mancanza assoluta di dati relativi alla sismicità locale; le uniche informazioni su sismi avvenuti nella zona in studio, tutti collegati all’attività della salsa di fondachello, ci sono tramandate da mercurio (1847), il quale fornisce le informazioni riassunte nella tabella 1. per quanto riguarda il sisma delle 19,30 del 26 marzo 1847, lo stesso mercurio (1847) avanza dubbi sulla possibilità che l’eruzione di un vulcano di fango, per quanto forte, possa provocare un sisma avvertito ad una distanza di 22 miglia; si ritiene quindi legittimo ipotizzare che si sia trattato di un sisma con ipocentro talmente profondo da avere un campo macrosismico che si estendeva fino a catania, e che l’evoluzione del vulcano di fango sia stata una conseguenza del movimento tellurico. 6. conclusioni sulla base di uno studio a carattere prevalentemente geomorfologico è stato riconosciuto il sistema di faglie giardini – mascali (tratto meridionale del sistema messina – fiumefreddo), il quale interseca il basso versante nord-orientale dell’edificio vulcanico etneo, condizionandone il reticolo idrografico e l’andamento della linea di costa. nell’ambito di un generale sollevamento dell’edificio etneo, le faglie di questo sistema hanno provocato una serie di abbassamenti localizzati, con conseguenti fenomeni di subsidenza, di catture e deviazioni fluviali e di formazione di laghi da sbarramento attualmente in via di estinzione. dall’analisi della morfologia dell’area, si può ipotizzare la seguente successione di eventi tettonici, suddivisa in fasi: 1ª fase: il fiume alcantara scorre, nel suo tratto terminale, lungo una valle di origine tettonica, con direzione nw-se e blocco ribassato a ne (romano et al., 1979) (fig. 6 a); 2ª fase: forse come cedimento causato dal generale sollevamento del territorio, inizia l’attività lungo le faglie del sistema: la faglia di giardini e la faglia di naxos formano un graben lungo il quale viene deviato il fiume alcantara, ed il torrente santa venera diventa suo tributario; si forma un delta subacqueo nell’attuale baia di giardini, riconoscibile dalla forma delle isobate (fig. 6 b); la faglia di fondachello provoca piccole deviazioni fluviali e la formazione di piccoli bacini lacustri (fig. 5: εε e ζζ); 3ª fase: una colata lavica, percorsa la valle dell’alcantara, sbocca in mare formando capo schisò; il fiume alcantara sovralluviona la zona a monte dello sbarramento (fig. 6 c); 4ª fase: a causa del continuo graduale fenomeno di sollevamento della zona, e conseguente ringiovanimento del rilievo e ripresa dell’attività erosiva, il fiume alcantara e il torrente santa venera erodono lo sbarra65 data fenomeni zona di osservazione attività della salsa terremoto disastroso nascita del vulcano di fango, 1693 gen. 11 (xi scala mercalli) sicilia orientale. con emissione di acqua fangosa a 32 metri di altezza. 1795 dic. numerose scosse durante nelle contrade attorno emissione di acqua fangosa tutta la notte, accompagnate alla gurna. fino a 7 metri di altezza. da rombi sotterranei. 1847 mar. 25 scosse nelle contrade attorno alla gurna. ripresa dell’attività. 1847 mar. 26, scosse nelle contrade attorno h 06,15 alla gurna. nessuna 1847 mar. 26, scosse fino a catania. nessunah 19,30 nelle contrade attorno crollo del fianco orientale 1847 apr. 9 esplosione. alla gurna. del vulcano di fango ed intensa emissione di acqua ricca di gas. controllo tettonico ... mento costituito dalla colata di capo schisò (fig. 6 d); 5ª fase: tutto il sistema giardini – mascali viene dislocato lateralmente dalla faglia del torrente minissale e dalla faglia della pernicana (fig. 5 e, f); 6ª fase: in tempi storici, movimenti tettonici, probabilmente lungo la faglia di fondachello, agevolano la fuoriuscita di gas e fango della salsa di fondachello. in questo contesto non è facile stabilire quale sia stata la fase che ha visto il teorizzato movimento lungo la faglia capo schisò – foce del torrente macchia, con probabile spostamento di circa 500 metri di alcuni delta subacquei, lungo una o più faglie con direzione nnessw e componente orizzontale destra. dall’analisi dei cataloghi dei terremoti si evidenzia una completa mancanza di eventi sismici storici attribuibili all’attività del sistema di faglie giardini mascali; le rare testimonianze di sismicità locale sono relative alla riattivazione nel dicembre del 1795 e nel marzo del 1847 del vulcano di fango conosciuto col nome di salsa di fondachello e allo sprofondamento del medesimo, avvenuto nell’aprile 1847; considerando che il sisma più intenso, avvenuto alle 19,30 del 26 marzo 1847 fu avvertito fino a catania, si può ipotizzare che esso sia imputabile all’attività di una delle faglie facenti parte del sistema giardini – mascali. studio effettuato con i fondi del m.u.r.s.t., nell’ambito della ricerca “morfodinamica di zone vulcaniche e/o sismicamente attive”, responsabile p. carveni. ringraziamenti ringraziamo i referees per gli utili e costruttivi consigli. lavori citati adorni g. & carveni p. (1993 a) geomorphology and seismotectonic elements in the giarre area, sicily. earth surf. proc. land., 18, 275-283. adorni g. & carveni p. (1993 b) anomalie del reticolo idrografico causate da eventi sismotettonici sul basso versante orientale dell’etna. boll. acc. gioenia sc. nat. catania, 26 (342), 197-206. amore c., d’alessandro l., giuffrida e., lo giudice a. & zanini a. (1992) dinamica litorale tra capo peloro e capo passero (sicilia orientale). boll. acc. gioenia sc. nat., 25 (339), 69-114. azzaro r., carveni p., lo giudice e. & rasà r. (1989) il terremoto di codavolpe (basso versante orientale etneo) del 29 gennaio 1989: campo macrosismico e fratturazione cosismica. boll. g.n.v., 1, 1-12. bella d., carveni p., musumeci c. & gresta s. (1996) aspetti geomorfologici conseguenti all'attività sismica locale sul basso versante orientale del vulcano etna. il quaternario, 9 (1), 365-368. borgia a., ferrari l. & pasquarè g. (1992) importance of gravitational spreading in the tectonic and volcanic evolution of mt. etna. nature, 357, 231-235. burollet p.f, mugnot g.m. & sweeney p. (1978) the geology of the pelagian block: the margins and basins of southern tunisia and tripolitania. in: nairn a., kanes w. & stelhi f.g., eds., the ocean basins and margins, plenum press, new york, 331-339. carapezza m. (1962) un esempio di eruzione laterale da faglia nell’apparato eruttivo etneo. acta geol. alpina, 8, 249-276. carbone m.s., cosentino m., grasso m., lentini f., lombardo g. & patanè g. (1982 a) elementi per una prima valutazione dei caratteri sismotettonici dell’avampaese ibleo (sicilia sud-orientale). mem. soc. geol. it., 24, 507-520. carbone m.s., grasso m. & lentini f. (1982 b) considerazioni sull’evoluzione geodinamica della sicilia sud-orientale dal cretaceo al quaternario. mem. soc. geol. it., 24, 367-386. carbone s., grasso m. & lentini f. (1982 c) elementi per una valutazione degli eventi tettonico-sedimentari dal cretaceo al quaternario nella sicilia sud-orientale. in catalano r. & d’argenio b., eds., guida alla geologia della sicilia occidentale. soc. geol. it., palermo, 103-109. carbone s., grasso m. & lentini f. (1987) lineamenti geologici del plateau ibleo (sicil ia s.e.). presentazione delle carte geologiche della sicilia sud-orientale. mem. soc. geol. it., 38, 127-135. carveni p. & bella d. (1994) aspetti geomorfologici legati ad attività sismica su vulcani attivi: il basso versante orientale dell'etna come modello di studio. boll. acc. gioenia sc. nat., 27 (346), 253-285. carveni p., bella d., filetti g., leonardi m.c., musumeci c. & sturiale g. (1996) zonazione sismica del territorio di giarre (catania) mediante l'analisi di sismi locali avvenuti nel periodo 18551989. att. conv. lincei, "la stabilità del suolo in italia: zonazione sismica-frane", 134, 389-393. carveni p., filetti g. & bella d. (1997) aspetti geomorfologici e sismologici connessi a fenomeni di tettonica gravitativa nel basso versante orientale dell'etna. geogr. fis. dinam. quat., 20, 43-49. carveni p., grasso m.f., romano r. & tricomi s. (1991 a) vulcanismo del margine settentrionale ibleo. mem. soc. geol. it., 47, 417-429. carveni p., leonardi a. & romeo m. (1993) rapporti tra vulcaniti submarine e depositi plio-pleistocenici dei dintorni di palagonia (avampaese ibleo, sicilia). boll. acc. gioenia sc. nat., vol. 26, 342, 207-237. carveni p., romano r., capodicasa a. & tricomi s. (1991 b) geologia dell’area vulcanica di capo passero (sicilia sud-orientale). mem. soc. geol. it., 47, 431-447. carveni p. & sturiale g. (1999) fasi tettoniche, fenomeni vulcanici e geomorfologia della zona di monte casale di san basilio, lungo il margine settentrionale dei monti iblei (sicilia orientale). il quaternario, 12 (1), 85-98. casero p., cita m.b., croce m. & de micheli a. (1984) tentativo di interpretazione evolutiva della scarpata di malta basata su dati geologici e geofisici. mem. soc. geol. it., 27, 233-153. continisio r., ferrucci f., & gaudiosi g. (1997) malta escarpment and mt etna: early stages of an asymmetric rifting process? evidences from geophysical and geological data. acta vulcanologica, 9, 45-53. cristofolini r. (1966) le manifestazioni eruttive basi66 p. carveni et al. che del trias superiore nel sottosuolo di ragusa. per. min., 35, 1-38. cristofolini r., lentini f., patanè g. & rasà r. (1979) – integrazione di dati geologici, geofisici e petrologici per la stesura di un profilo crostale in corrispondenza dell’etna. boll. soc. geol. it., 98, 239-247. de jong k.a., manzoni m., stravenga t., van djik f., van der voo r. & zijderveld j.d.a. (1973) – paleomagnetic evidence for rotation of sardinia during the early miocene. nature, 243, 281-283. dewey j.f., helman m.l., turco e., hutton d.h.w. & knott s.d. (1989) – kinematics of the western mediterranean. in: coward m.p., dietrich d. & park r.g. (editors): alpine tectonics geol., spec. publ., 45, 265-283. di geronimo i., ghisetti f., lentini f. & vezzani l. (1978) lineamenti neotettonici della sicilia orientale. mem. soc. geol. it., 19, 543-549. di grande a. (1967) i sedimenti pleistocenici del margine settentrionale dell’altipiano ibleo. att. acc. gioenia sc. nat., catania, serie vi, 18 (suppl. sc. geol.), 247-263. di grande a. (1969) l’alternanza neogenico-quaternaria di vulcaniti e sedimenti al margine nord-occidentale dell’altipiano ibleo. att. acc. gioenia sc. nat., catania, 4, 36 pp. di grande a. (1972) geologia dell’area a nord di augusta francofonte (sicilia se). att. acc. gioenia sc. nat., s. 7, 4, 1-32. ferrari l., garduņo v.h. & neri m. (1991) – i dicchi della valle del bove, etna: un metodo per stimare le dilatazioni di un apparato vulcanico. mem. soc. geol. it., 47, 495-508. finetti i. (1982) structure, stratigraphy and evolution of central mediterranean. boll. geof. teor. appl., 96, 247-312. finetti i., lentini f., carbone s., catalano s. & del ben a. (1996) il sistema appennino meridionale arco calabro sicilia nel mediterraneo centrale: studio geologico-geofisico. boll. soc. geol. it., 115, 529-559. finetti i. & morelli c. (1972) wide scale digital seismic exploration of the mediterranean sea. boll. geof. teor. appl., 14, 291-342. frazzetta g. & romano r. (1978) approccio di studio per la stesura di una carta del rischio vulcanico (etna-sicilia). mem. soc. geol. it., 19, 691-697. frazzetta g. & villari l. (1981) the feeding of the eruptive activity of etna volcano. the regional stress field as a constraint to magma uprising and eruption. bull. volcan., 44 (3), 269-282. gemmellaro c. (1858) la vulcanologia dell’etna. la topografia, la geologia, la storia delle sue eruzioni, la descrizione e lo esame de’ fenomeni vulcanici. tipografia dell’accademia gioenia di c. galatola, catania, 267 pp. ghisetti f. (1979) – relazione tra strutture e fasi trascorrenti e distensive lungo i sistemi messinafiumefreddo, tindari-letojanni e alia-malvagna (sicilia nord-orientale): uno studio microtettonico. geol. rom., 18, 23-58. ghisetti f. & vezzani l. (1982) the recent deformation mechanism of the calabrian arc. in: mantovani e. & sartoni r. (edi-tors): structure, evolution and present dynamics of the calabrian arc. earth evolution sciences, 3, 197-206. giarrizzo s. (1989) dizionario etimologico siciliano. herbita editrice, palermo, 390 pp. giese p. & morelli c. (1975) crustal structure in italy. in: ogniben l., parotto m. & praturlon a. (editors), structural model of italy: maps and explanatory notes. quad. ricerca sci., 90, 453489. gillot p.y., kieffer g. & romano r. (1994) the evolution of mount etna in the light of potassium-argon dating. acta vulcanologica, 5, 81-87. gironi f. (2003) cosa c’è sotto. quark, 23, 50-57. gresta s., bella d., musumeci c. & carveni p. (1997) some efforts on active faulting processes (earthquakes and aseismic creep) acting on the eastern flank of mt. etna (sicily). acta vulc., 9 (1/2), 101108. guest j.e., chester d.k. & duncan a.m. (1984) the valle del bove, mount etna: its origin and relation to the stratigraphy and structure of the volcano. jour. volc. geoth. res., 21, 1-23. guerrera f. & wezel f.c. (1974) – nuovi dati stratigrafici sui flysch oligomiocenici siciliani e considerazioni tettoniche relative. riv. min. sic., 145-147, 2751. gvirtsman z. & nur a. (1999) the formation of mount etna as the consequence of slab roll-back. nature, 401, 782-785. istituto idrografico della marina italia (2001) foglio 22, da capo santa croce a messina e capo dell’armi, scala 1:100.000. genova. kieffer g. (1983 a) l’évolution struttural de l’etna (sicile) et les modalités du contrôle tectonique et volcano-tectonique de son activité. faits et hypothèses après les éruptions de 1978 et 1979. rev. géogr. phys. géol. dyn., paris, 24 (2), 129152. kieffer g. (1983 b) dèplacement progressif vers l’est des voies d’alimentation magmatiques de l’etna (sicile). bull. soc. géol. fr., 25 (3), 369-378. kieffer g. & tanguy j.c. (1993) l’etna: évolution structurale, magmatique et dynamique d’un vulcan “poligenic”. mem. soc. géol. france, 163, 253-271. lanzafame g. & bousquet j.c. (1997) the maltese escarpment and its extension from mt etna to the aeolian islands (sicily): importance and evolution of a lithosphere discontinuity. acta vulcanologica, 9, 121-133. lentini f. (1982) the geology of the mt. etna basement. mem. soc. geol. it., 23, 7-25. lentini f., carbone s., cucno c., grasso m., scamarda g. & sciuto f. (1986) carta geologica del settore nord-orientale ibleo (sicilia s.e.). scala 1:50.000, s.e.l.ca., firenze. lentini f., catalano s., carbone s., caliri a., carveni p., di stefano a., gargano c., grasso m., guarnieri p., la manna f., lentini r., messina a., romeo m., strazzulla s., vinci g. & vinciguerra g. (2000) – carta geologica della provincia di messina. scala 1:50.000. s.el.ca., firenze. lentini f., grasso m. & carbone s. (1987) – introduzione alla geologia della sicilia e guida all’escursione. conv. soc. geol. it. “sistemi avanfossa – avampaese lungo la catena 67controllo tettonico ... appenninico – maghrebide”. naxos – pergusa 2225 aprile 1987. lo giudice e., patanè g., rasà r. & romano r. (1982) the structural framework of mt. etna. mem. soc. geol. it., 23, 125-158. lo giudice e. & rasà r. (1992) very shallow earthquakes and brittle deformations in active volcanic areas: the etnean region as an example . tectonophysics, 202, 257-268. lyell c. (1859) on the structure of lavas which have consolidated on steep slopes; with remarks on the mode of origin of mt. etna, and on the teory of "center of elevation". phil. trans. roy. soc., 703785. marchesini e., conedera c., morabito g. & macii l. (1964) studio fotogeologico dell'etna. riv. min. sic., 85-87, 83-95. mcguire w.j., stewart i.s. & saunders s.j. (1997) intra-volcanic rifting at mount etna in the context of regional tectonics. acta vulcanologica, 9, 147156. mercurio g.a. (1847) sulla salsa di fondachello nel comune di mascali, del profondamento parziale del cono argilloso e dell'apparizione d'un'acqua minerale gassosa. stabilimento di pietro giuntini, catania, 29 pp. monaco c., petronio l. & romanelli m. (1995) tettonica estensionale nel settore orientale del monte etna (sicilia): dati morfotettonici e sismici. studi geologici camerti, convegno geodinamica e tettonica attiva del sistema tirreno-appennino, 363-374. monaco c., tapponnier p., tortorici l. & gillot p.y. (1997) late quaternary slip rates on the acirealepiedimonte normal faults and tectonic origin of mt. etna (sicily). earth planet. sc. lett., 147, 125139. monaco c. & tortorici l. (1995) tettonica estensionale quaternaria nell’arco calabro e in sicilia orientale . studi geologici camerti, convegno geodinamica e tettonica attiva del sistema tirreno-appennino, 351-362. morelli c. (1970) physiography, gravity and magnetism of the tyrrhenian sea. boll. geofis. teor. appl., 12: 275-305. neri m., garduņo v.h., pasquarè g. & rasà r. (1991) – studio strutturale e modello cinematico della valle del bove e del settore nord-orientale etneo. acta vulcanologica, 1, 17-24. ogniben l. (1960) – nota illustrativa dello schema geologico della sicilia nord-orientale. riv. min. sic., 64-65, 183-212. ogniben l., parotto m. & praturlon a. (1975) structural model of italy. c.n.r., quaderni de “la ricerca scientifica”, 90, 502 pp. patacca e., scandone p., giunta c. & liguori v. (1979) mesozoic paleotectonic evolution of the ragusa zone (se sicily). geol. romana, 18, 331-369. romano r. (1982) succession of the volcanic activity in the etnean region. mem. soc. geol. it., 23, 2748. romano r., lentini f., sturiale c., amore c., atzori p., carter s.r., cristofolini r., di geronimo i., di grande a., duncan a.m., ferrara v., ghisetti f., guest j.e., hamill h., patanè g., pezzino a., puglisi d., schilirò f., torre g. & vezzani l. (1979) carta geologica del monte etna, scala 1:50.000, litogr. art. cartogr., firenze. romano r. & sturiale c. (1981) geologia del versante sud-orientale etneo, f°. 270 iv (no, ne, so, se). boll. soc. geol. it., 100 (1), 11-40. scandone p. (1982) geology of the calabrian arc. in: mantovani e. & sartoni r. (editors): structure, evolution and present dynamics of the calabrian arc. earth evolution sciences, 3: 172-180. selli r. & fabbri a. (1971) tyrrhenian: a pliocene deep sea. rend. cl. fis. mat. nat. accad. lincei, 8, 104-116. tanguy j.c., condomines m. & kieffer g. (1997) evolution of the mount etna magma: constraints on present feeding system and eruptive mechanism. jour. volc. geot. res., 75, 221-250. van bemmelen r.w. (1969) origin of the western mediterra-nean sea . verh. k. -ned. geol. mijnbouwkd. genoot., geol. ser., 26, 13-52. 68 ms. ricevuto il 17 novembre 2004 testo definitivo ricevuto il 22 febbraio 2005 ms. received: november 11, 2004 final text received: february 22, 2005. p. carveni et al. impaginato santilli llaattee hhoolloocceennee eennvviirroonnmmeennttaall eevvoolluuttiioonn ooff tthhee uuppppeerr vvaallllee ddeell ggaalllloo ((cceennttrraall aallppss)):: aann iinntteerrddiisscciipplliinnaarryy ssttuuddyy mmaauurriizziioo ssaannttiillllii11,, mmaannuueellaa ppeellffiinnii11,, mmaarrccoo ccaacccciiaanniiggaa22,, rroobbeerrttoo ccoommoollllii33 && cceessaarree rraavvaazzzzii44 1dipartimento di scienze della terra, sezione di geologia e paleontologia, università di milano, via mangiagalli 34, 20133 milano (italia); e-mail: maurizio.santilli@unimi.it; e-mail: manuela.pelfini@unimi.it 2dipartimento di biologia, sezione di botanica sistematica, università di milano, via celoria 26, 20133 milano e-mail: marco.caccianiga@unimi.it 3dipartimento di scienze dell’ambiente e del territorio, università di milano-bicocca, piazza della scienza 1, 20126 milano; e-mail: roberto.comolli@unimib.it 4cnr, istituto per la dinamica dei processi ambientali, piazza cittadella 4, 24129 bergamo e-mail: cnrbg1@mediacom.it abstract through an interdisciplinary study based on the application of geomorphological, stratigraphic, dendrochronological, pedological and phytosociological methods, the late holocene environmental evolution of the valley bottom of the upper valle del gallo (upper valtellina / upper valle dello spöl, central italian alps), an area high in the mountains characterized by a strong environmental dynamism, has been reconstructed. the geomorphological survey and some stratigraphic sections prove that the studied area was occupied, probably from the late-glacial period, by a lacustrine basin. laminites, microturbidites, fluvial, deltaic and debris flow deposits formed by the progradation of the surrounding fans deposited in the lake and buried it before the middle holocene, originating a flat primitive valley bottom. this original surface was subsequently carved by the regressive erosion of the main river and its tributaries which isolated, especially since the middle ages, numerous surfaces from the more recent debris flow activity. some fans were partially dismantled while in some depressed sectors a succession of silty deposits formed by sheetfloods accumulated. the adaptation and the reaction of the arboreal vegetation to the debris flow activity allowed us to apply dendrogeomorphological techniques thanks to which some events were dated and the recent morphologic evolution of one of the fans reconstructed. the ecological succession takes place on two types of carbonatic substratum characterising the study area: sandy gravel deriving from debris flows, silt and fine sands deriving from sheetfloods. the soils and vegetation of the upper valle del gallo are generally scarcely developed. the vegetation is dominated by pinus montana forests at various degrees of evolution, following pioneer communities in which the pine plays a key role. the pedological study shows that pine forests develop on leptosols, poor and dry grounds rich in rock fragments of the fans, only locally susceptible of evolving into cambisols. these surfaces are frequently buried by debris flows that cover the grounds thus inducing regressive stages in the vegetational series. yet trees often survive these events since they are able to heal their scars, straighten themselves up and to develop adventitious roots from the buried base of the stems and branches. on the contrary fluvisols develop on sheetfloods silty deposits, where peculiar herbaceous communities predominate, adapted to a light periodic burial that does not kill the vegetation. last but not least must have been the influence of the anthropic deforestation, that has probably contributed in a considerable way to the present landscape setting. sommario evoluzione ambientale tardo-olocenica dell’alta valle del gallo (alpi centrali): uno studio interdisciplinare. mediante uno studio interdisciplinare basato sull’impiego di metodi geomorfologici, stratigrafici, dendrocronologici, pedologici e fitosociologici, è stata ricostruita l’evoluzione ambientale tardo-olocenica del fondovalle dell’alta valle del gallo (alta valtellina/alta valle dello spöl so), un’area d’alta montagna contraddistinta da un’elevata dinamicità ambientale. il rilevamento geomorfologico e alcune sezioni stratigrafiche documentano che l’area studiata era occupata, probabilmente a partire dal tardiglaciale, da un bacino lacustre. in esso si sono depositate laminiti, microtorbiditi, depositi deltizi, fluviali e di debris flows derivati dalla progradazione dei conoidi circostanti, che hanno interrato il lago prima della metà dell’olocene, dando origine ad un primitivo fondovalle pianeggiante. questa originaria superficie è stata successivamente intagliata dall’erosione regressiva del torrente principale e dei suoi affluenti, che ha isolato, soprattutto a partire dal medioevo, diverse superfici dall’attività più recente dei debris flows. alcuni conoidi sono stati parzialmente smantellati, mentre in alcuni settori depressi si è accumulata una successione di depositi limosi derivati da processi di sheetflood. gli adattamenti e la reazione della vegetazione arborea all’attività dei debris flows hanno consentito l’impiego di tecniche dendrogeomorfologiche mediante cui sono stati datati alcuni eventi ed è stata ricostruita l’evoluzione morfologica recente di uno dei conoidi. sui due tipi di substrato carbonatico che caratterizzano l’area di studio, ghiaie sabbiose derivanti da debris flows, limi e sabbie fini derivanti da sheetfloods, ha luogo la successione ecologica. i suoli e la vegetazione dell’alta valle del gallo sono, in generale, scarsamente evoluti. la vegetazione è dominata da pinete a pinus montana con gradi diversi di evoluzione, che seguono aggruppamenti pionieri in cui il pino gioca un ruolo chiave. lo studio pedologico indica che le pinete si sviluppano su suoli poveri, scheletrici e asciutti di conoide, i leptosols, solo localmente suscettibili di evolvere verso i cambisols. frequentemente queste superfici vengono sepolte da colate di detrito che ricoprono i suoli e inducono stadi regressivi nella serie vegetazionale. tuttavia, spesso gli alberi sopravvivono a questi eventi poiché sono in grado di rimarginare le cicatrici, raddrizzarsi e sviluppare radici avventizie dalla base sepolta dei fusti e dei rami. sui depositi limosi di sheetfloods, invece, si sviluppano fluvisols e prevalgono peculiari aggruppamenti erbacei adattati ad un leggero seppellimento periodico che non uccide la vegetazione. non meno importante deve essere stata, infine, l’influenza del disboscamento antropico, che ha probabilmente contribuito in modo notevole all’assetto del paesaggio attuale. keywords: alluvial fans, debris flows, holocene stratigraphy, dendrogeomorphology, mountain pine, alpine soils, vegetation. parole chiave: conoidi alluvionali, debris flows, stratigrafia olocenica, dendrogeomorfologia, pino montano, suoli alpini, vegetazione. il quaternario italian journal of quaternary sciences 1155(2), 2002, 187-208 188 m. santilli et alii 11.. iinnttrroodduuccttiioonn this report deals with the late holocene environmental evolution of the upper valle del gallo (upper valtellina / upper valle dello spöl, central italian alps). this area high in the mountains shows a peculiar landscape characterized by a strong dynamic of the slopes, by the aggradation of fans mostly originated by debris flows and by a hydrographic network which is progressively deepening. the upper valle del gallo is particularly suitable to study the frequency and the effects of some geomorphologic processes strictly associated with the atmospheric dynamics, especially with precipitation, on the environment. the reaction of vegetation to such a rapid geodynamics and to a specific bedrock geochemistry (carbonates) allowed us to analyse the ecological interactions between geomorphic and sedimentary processes, the soil evolution and the factors determining it (climate, human influence, etc.). moreover, this interdisciplinary research intends to promote the conservation and the enhancement of this area located between two wide protected areas, the stelvio national park and the swiss national park, showing at present a scant human presence. 22.. ssttuuddyy aarreeaa the valle del gallo is situated on the northeast extremity of the lombardy (northern italy), in the stelvio national park, (fig. 1). the studied area extends from passo di fraele (1952 m) to ponte di pra grata (1864 m) (fig. 1), and is entirely included in the carbonatic succession of the norian age related to the quattervals nappe, except for some klippen belonging to the scarl-umbrail system forming some mountain tops (pozzi & giorcelli, 1960; bonsignore et al., 1969; berra, 1994). as showed by the analysis of the data (santil l i, 2000) from the meteorological station in cancano (aem milano, 1948 m a.s.l., see fig. 1), the climate of the upper valle del gallo corresponds to the alpine continental one (fig. 2). the average annual precipitation are scarce (822 mm), but, due to the altitude, the potential evapotranspiration is rather limited (428 mm). the soil water balance shows a small deficit in july. the carbonatic bedrock, the diffuse cover of coarse detrital sediments and the soils features reduce the available water capacity; consequently some aridity problems can occur during dry years. due to the high altitude of the surrounding mountains (up to 3180 m), wide portions of the slopes are beyond the tree limit and are without vegetative cover. hence the climate is favourable for a strong weathering which can produce large quantities of debris that, accumulating on the slopes, are susceptible of moving due to the frequent heavy summer storms. as regards vegetation, the studied area is included in the upper subalpine belt and is dominated by monospecific pinus montana forests. pinus montana in the fig. 1 location, hydrography and orography of the studied area. the valle del gallo covers the area northward the passo di fraele and belongs to the hydrographic basin of the black sea (through the danube). the box shows the area represented in fig. 5. ubicazione, idrografia e orografia dell’area studiata. la valle del gallo si estende a nord del passo di fraele e appartiene al bacino idrografico del mar nero (attraverso il danubio). il riquadro mostra l’area rappresentata in fig. 5. broadest sense of the word (pinus mugo aggregate, according to minghetti, 1997; pinus of the mugo group according to pignatti, 1982; see also: hess et al., 1967; gaussen et al., 1993) includes two main species: pinus mugo turra 1764, having a dwarf habitus, which prefers carbonate substrata and grows in the eastern alps and in the carpathian, and pinus uncinata dc. in lam & dc. 1805, having an arborescent habitus, which prefers siliceous substrata and grows in the western alps and in the pyrenees. moreover they are different for several morphological features such as the cone shape or the needle anatomy. nevertheless, they frequently originate intermediate or hybrid forms hard to be taxonomically located. mountain pines of the valle del gallo have a prevalent arborescent habitus (see fig. 3), but even if this feature seems to be proper to pinus uncinata dc., its geographical and ecological location is similar to that of pinus mugo turra, thus in the present study the generic definition of “mountain pine” is preferred. the valley was subject to an intense anthropic 189late holocene environmental evolution ... exploitation for the presence of rich iron deposits that surface on its slopes. the mining activity, documented from 1272 to 1875, helped the development of a prosperous industry, that brought about the building of roads, structures and furnaces for the mineral fusion (agostoni,1923; leoni, 1953a-b; zazzi, 1982). the furnaces were fed with coal produced in the several charcoal pits which are still disseminated all over the valley; the wood was obtained by felling the mountain pines and removing their stumps. the intense deforestation has probably had a great influence on the recent evolution of the soil and vegetation. the bibliography available on the natural history of the valle del gallo is rather limited. general geomorphological information was provided by giorcelli (in pozzi & giorcelli, 1960) and by saibene (1973). these authors pointed out a series of erosive cycles of the neogenefig. 2 ombrothermic diagram by walter & lieth and soil water balance according to thornthwaite on the basis of the data of the meteorological station in cancano (aem milano, see fig. 1). the temperature and precipitation course shows the absence of an aridity period (p>2t) and a continental-like pluviometric system; the soil water balance shows a little deficit in july. the awc calculated (35 mm) refers to a skeletal soil representative of the fan. diagramma ombrotermico di walter & lieth e del bilancio idrico del suolo secondo thornthwaite in base ai dati della stazione meteorologica di cancano (aem milano, cfr. fig. 1): gli andamenti delle temperature e delle precipitazioni indicano l’assenza di un periodo di aridità (p>2t) ed un regime pluviometrico di tipo continentale; il bilancio idrico del suolo mostra un piccolo deficit nel mese di luglio. l’awc calcolata (35 mm) si riferisce ad un suolo scheletrico rappresentativo dei conoidi. fig. 3 remarkable scar on the stem of a mountain pine hit by a debris flow in 1959. the development of compression wood contributes to the trunk straightening, following its inclination. the box represents a stem section showing compression wood (darker in the lower part) and a corrasion scar (in the upper part); both of them date back to 1986. (photos by santilli). grossa cicatrice sul fusto di un pino montano investito da una colata di detrito risalente al 1959. lo sviluppo di legno di compressione coadiuva il raddrizzamento del tronco successivo alla sua inclinazione. il riquadro raffigura una sezione di fusto mostrante legno di compressione (più scuro in basso) e una cicatrice d’abrasione (in alto); entrambi risalgono al 1986 (foto santilli). 190 quaternary mainly caused by glaciations. glacial erosion on the main valleys promoted a regressive erosion and fluvial captures which modified the ancient hydrography. useful information on vegetation is available in furrer (1914), furrer & longa (1915), braun blanquet et al. (1954), giacomini & pignatti (1955), pirola & di benedetto (1959), giacomini (1960), pirola (1973), pedrotti et al. (1974), minghetti (1996). 33.. mmaatteerriiaallss aanndd mmeetthhooddss the environmental setting of the upper valle del gallo was deduced from the integration of a detailed geomorphological survey with photointerpretation (photograms no. 11-12-13, stripe 55, flight tem 1 regione lombardia 1981, and no. 2571-2572, flight alifoto 1975), and with stratigraphic, dendrochronological, pedological and vegetational studies. a general research was carried out on the whole valley sector and a more detailed study on the valle della casina fan, one of the lateral valleys. moreover some historic information was provided by some photographs dating back to the end of the 19th century, and by a map of the land register of 1844 “mappa del comune censuario di valle di dentro”. seventeen stratigraphic sections were described. some buried layers rich in organic matter and a charred wood were dated through radiocarbon. the definition of stratigraphic units is the one used by the international stratigraphic code (salvador, 1994). some debris flows of the valle della casina fan were dated using dendrogeomorphological techniques (e.g. see: alestalo, 1971; shroder, 1980; heikkinen, 1994; strunk, 1995) applied to mountain pines. more than two hundred increment cores were extracted from damaged pinus montana, along the valle della casina fan channels and some cross-sections of stems and branches were made. the trees showed corrasion scars and/or compression wood on slanting stems, both caused by the impact of debris carried by water on the stems (fig. 3). the compression wood is produced by conifers in order to bring the stem back to its vertical position whenever its orientation is altered. the scars and the year of appearance of the compression wood were dated. owing to the fact that the trees were usually heavily damaged, the ring recognition and counting on many samples were often difficult. finally only 53 trees were useful for dating purposes. some historical data together with daily precipitation recorded at the meteorological station in cancano (after 1961) confirmed some episodes which had been dated, even if it is not so easy to correlate the occurrence of the debris flows with precipitation (e.g. see: govi et al., 1985; polloni et al., 1991; govi et al., 1994; flageollet et al., 1999; van asch et al. 1999). thirty-two pedological profiles have been dug. for each horizon the color, the roots, the skeleton, the structure, the texture, the boundaries and the effervescence to hcl have been considered (according to sanesi, 1977). the analysis carried out in laboratory, on the fine earth, sifted at 2 mm, determined the organic carbon (oxidation with bichromate potassium), the ph (soil/water ratio 1:2.5), the total carbonates (gas-volumetric method) and the apparent texture (by smoothing with an esenwein’s pipette) (according to the osservatorio nazionale pedologico, 1994). soils have been classified according to the world reference base for soil resources taxonomic system (isss-isricfao, 1998). vegetation has been studied by using the phytosociological method of the zurich-montpellier school (braun-blanquet & jenny, 1926; braun-blanquet, 1964). thirty-eight relevés have been processed by using the braun-blanquet cover-abundance scale modified by pignatti (1952), in areas considered homogeneous from a geomorphological point of view. upgma has been used as clustering method to carry out the cluster analysis. a first analysis has been performed with the chord distance index using the cover values of the species transformed into numerical values (van der maarel, 1979). the following one has been carried out by using m. santilli et alii fig. 4 panoramic photo of the upper valle del gallo (see fig. 5): val paolaccia fan (1), valle della casina fan (2), val mora fan (3), “valle del pizzo aguzzo” fan (4; actually, the valley does not have any place-name), inactive fan (5a-5c) and active fan (5b) of val bruna, moraine (6) (photo by santilli). panoramica dell’alta valle del gallo (cfr. fig. 5): conoide della val paolaccia (1), conoide della valle della casina (2), conoide della val mora (3), conoide della “valle del pizzo aguzzo” (4; in realtà la valle è priva di toponimo), conoide inattivo (5a-5c) e conoide attivo (5b) della val bruna, morena (6) (foto santilli). 191 the jaccard coefficient and the data relevant to the species presence/absence. sporadic species have been excluded from the clustering processing. the floristic nomenclature is the one used by pignatti (1982). 44.. rreessuullttss 44..11.. ggeeoommoorrpphhoollooggiicc ssuurrvveeyy debris flow fans with a complex structure most of which are coalescent and come from both the valley sides occupy the upper valle del gallo. (fig. 4-5). creeks, often active only during heavy rains, sink on the eastern slope of the fans near their apexes. on the contrary, on the western slope they partially flow on their respective fan surface before sinking. this mirrors the northward/northward-eastward dipping of the strata (saibene, 1973). at the valley head the val paolaccia fan completely occupies the valley bottom (1 in fig. 4-5) originating the passo di fraele. the valle della casina (2) and the val mora fans (3) extend on the eastern valley side late holocene environmental evolution ... fig. 5 map of the fans and of the quaternary deposits of the upper valle del gallo (see fig. 4) (from the regional technical map 1:10.000 sections n° d1b3 “lago di livigno sud” and n° d1c3 “s. giacomo di fraele”, realisation 198083; coordinates are in the gaussboaga system). carta dei conoidi e dei deposit i quaternari dell’alta valle del gallo (cfr. fig. 4) (dalla carta tecnica r e g i o n a l e 1:10.000, sezioni n° d1b3 “lago di livigno sud” e n° d1c3 “s. giacomo di fraele”, r e a l i z z a z i o n e 1980-83; le coordinate sono nel sistema gaussboaga). 192 while the “valle del pizzo aguzzo” (4) and the val bruna ones occupy the western slope (5). the latter is composed of a central active portion (5b), a southern inactive part (5a) and a northern one (5c) located westwards of a hillock (6). according to giorcelli (in pozzi & giorcelli, 1960) this hillock is a moraine deposited during the gschnitz stadium (early late-glacial). the val mora fan and the southern part of the val bruna one (5a) are now inactive surfaces bordered by scarps, up to 50-m high, facing the val bruna, val mora and valle del gallo the respective rivers of which flow at lower altitudes. these surfaces are considered (according to martina, 1954) as the remains of an ancient flat valley bottom successively dissected by acqua del gallo, the river of the main valley, and its tributaries; other edges of the same valley bottom are represented by some small parts of the valle della casina and “valle del pizzo aguzzo” fans. near the val paolaccia fan, the river acqua del gallo carves silty deposits (see par. 4.2.3.). the border of terraces formed by the crack has a winding shape which is more evident down the valley and represents an area where erosion gives birth to small incisions separated by crests (see fig. 8). the valle della casina fan (figs. 4-5-6) extends nearly for 1 km between an altitude of 2020 and 1885 m a.s.l. there is a main channel (a in fig. 6) near the northern margin; it is normally dry and marked by terraces separating other channels and interchannel zones with pinus montana forests. a part of the channel is edged by a high debris terrace (d). downhill the val mora road (1935 m) the channel still carves the fan unti l i t forms a ten-meter deep scarp before flowing into acqua del gallo. two secondary channels (b) and (c) originate from the main channel (a). channels (a) and (b) border a zone with a discontinuous vegetation and dwarf and damaged trees (e). nearby there is another zone covered with a tal ler and thicker forest (f). channel (g) originates from the secondary channel (c). finally, at the fan-toe a few meter above the creek acqua del gallo a terrace (h) exists. 44..22.. qquuaatteerrnnaarryy ssttrraattiiggrraapphhyy the quaternary deposits cropping out on the valley bottom of the upper valle del gallo have been assigned to three lithostratigraphic units, the names of which derive from specific localities: the acqua del gallo unit, the valle della casina unit and the val paolaccia unit (fig. 5). 44..22..11.. aaccqquuaa ddeell ggaalllloo uunniitt description and interpretation. the acqua del gallo unit is a carbonatic clay sedimentary succession with a coarsening-upward sequence (fig. 7). the lower part is formed by massive grey clays; the middle part by horizontally laminated clays alternating between levels of silty clays and fine sands in fining-upwards laminas. deposits are interpreted as decanted laminites and microturbidites deposited in a lacustrine environment. the uppermost part of the succession alternates between graded and well-sorted sands, silt and silty clays. the succession is clast free. plant remains and macrofossils were not observed. thickness. the maximum visible thickness is 8 m (section 3; figs. 5-6-7); the estimated thickness is at least 35 m, between 1885 and 1920. name. its name comes from the creek that carved it and exposed the succession. lateral extent and relations with the other m. santilli et alii fig. 6 morphological sketch map of the valle della casina fan. the box shows the area represented in fig. 11. schema morfologico del conoide della valle della casina. il riquadro mostra l’area rappresentata in fig. 11. stratigraphic units. boreholes carried out by aem milano at the passo di fraele (giorcelli in pozzi & giorcelli, 1960) and the exposed sections along the river bed of acqua del gallo allow us to identify these lacustrine deposits for more than 2 km from the inactive fan of val bruna (5a in figs. 4-5) to passo di fraele. the uppermost part of the acqua del gallo unit is interdigitated with alluvial deposits included in the valle della casina unit. type section. section 3 (fig. 7; appendix i); coordinates: 46° 34' 00'' n, 10° 14' 40'' e. age. no direct dating is available for this unit. considering its stratigraphic position, it is older than 4710 ± 90 14c yr b.p. (tab. 1; see par. 4.2.2.). previous studies. giorcelli (in pozzi & giorcelli, 1960) mentions a paleolake originated by the erosion processes of the last glacial cycle that caused the formation of a watershed in the upper valle del gallo, and by the obstruction of the val paolaccia fan at the passo di fraele. 44..22..22.. vvaallllee ddeellllaa ccaassiinnaa uunniitt description and interpretation. this unit (fig. 5) is made up of several interdigitated bodies of gravelly deposits expanding on the valley bottom at the base of tributary valleys. each element is composed of lenticular successions, scantily stratified, of clast-supported gravel beds with sandy matrix, occasionally separated by wellsorted sandy-silty levels. both fine fraction and clasts are carbonatic but locally are siliceous erratic, metamorphic clasts and iron ores. clasts have a subangular or subrounded shape, are chaotic or have a weak stratification, with sands and a high primary porosity. buried soils are common; brownish silty horizons rich in coal are sporadically embedded. the entire succession is markedly inclined towards the valley bottom and distinctly finingdownward. it can be considered as a series of wedge-shaped and coalescent debris flow fans. the uppermost part of section 3 (acqua del gallo unit) shows the progradation of a fan covering gravelly and sandy alluvial deposits. the latter differ from the debris flow deposits because they are organized in channel bars, are better sorted, graded and partially stratified. they are included in the valle della casina unit. name. the present study analyses in detail the fan of valle della casina. boundaries and relations with the other strati193late holocene environmental evolution ... table 1 radiocarbon dating. date 14c. fig. 7 section 3 of the acqua del gallo unit (see appendix i) sezione 3 dell’unità dell’acqua del gallo (cfr. appendice i). graphic units. the exposed upper surfaces are characterized by an active aggradation or by the development of leptosols (locally cambisols) (see par. 4.4.). the basal part of the unit is interdigitated with lacustrine deposits of the acqua del gallo unit. some fans are interrupted by river downcuttings, between which the val bruna subunit (see further on) is embanked. a depressed sector in the southern part is covered by the val paolaccia unit. the contact surface is marked by a buried leptosol, locally eroded (see fig. 10 and par. 4.2.3.). age. a thin layer rich in coal at the “valle del pizzo aguzzo” fan-toe (see fig. 6) was dated 4710 ± 90 14c yr b.p. (tab. 1). a buried charred wood embedded in silty, reddish horizons rich in coal and partly pedogenized between gravelly layers in the upper part of the valle della casina fan (section 5 in fig. 6) was dated 1720 ± 50 14c yr b.p. (tab. 1). some recent surfaces (since the end of the 19th century) were dated through dendrogeomorphology. previous studies. these fans were mentioned by martina (1954), borgonovo (1955) and giorcelli (in pozzi & giorcelli, 1960). selected sections. no. 5 (coordinates: 46° 34' 10'' n, 10° 15' 00'' e; appendix i), 6 (46° 34' 00'' n, 10° 15' 10'' e) and 19 (46° 34' 10'' n, 10° 14' 50'' e) (fig. 6). subunits. the deposits embanked in the valle della casina unit and separated from the latter by an erosional surface were assigned to the val bruna subunit. the latter includes the active part of the val bruna fan (from which the name derives 5b in fig. 5) and the northern sector of the “valle del pizzo aguzzo” fan (fig. 5). the terrace (h) (fig. 6; see fig. 13) of the valle della casina fan is considered as a part of the “valle del pizzo aguzzo” fan separated by the erosion activity of the creek acqua del gallo. sections 40 and 46 (fig. 6; see fig. 13), coordinates 46° 34' 10'' n, 10° 14' 40'' e, are representative of this subunit. the buried soil included in section 46 was dated 3910 ± 60 14c yr b.p. (tab. 1). 44..22..33.. vvaall ppaaoollaacccciiaa uunniitt description and interpretation. the val paolaccia unit (fig. 8) is formed by a succession of centimetric layers made up of an undulating stratification of massive and well-sorted carbonatic silts and fine sands up to more than 4-m thick and totally clast-free. coal fragments are locally common, dispersed, concentrated in pockets or related to pedoturbations. pedogenized horizons and pedoturbations can only be found in the uppermost part (see section 2 in fig. 9 and appendix i). the structure of this succession suggests that it was formed in a terrestrial environment. the fine grain size, the good selection and the massive structure indicate that each layer resulted from the accumulation of single sheetfloods. these processes occur when dilute mixtures of water and sediments flow as traction currents spreading on the fan surface (bull, 1972; nichols, 1999). they cause a thin burial which does not kill the vegetation (see par. 4.5.3.), which promptly reacts by developing new roots and emerging stems. this also explains the common pedoturbation associated with the pedogenized horizons observed in the upper part of the succession. name. these sheetflood deposits come from the val paolaccia (figs. 58). 194 m. santilli et alii fig. 8 val paolaccia unit: location, extent, erosion morphologies (in the box) and location of the stratigraphic sections (numbers). unità della val paolaccia: localizzazione, estensione, morfologie d’erosione (nel riquadro) e ubicazione delle sezioni stratigrafiche (numeri). 195late holocene environmental evolution ... lateral extent, thickness and relations with the other stratigraphic units. the unit is interdigitated with the gravel deposits forming the val paolaccia fan and covers with an onlap contact the depressed sectors around it. these fine deposits can also be found on the fan surface where they locally bury the soil and vegetation with a layer up to 10-15-cm thick. some thicker successions have been observed in wide natural downcuttings in the north-west sector of the unit. sections 39 and 49 show the contact with the valle della casina unit marked by a buried leptosol (locally eroded) (figs. 8-9-10). selected sections. no. 39, 49, 2 (coordinates: 46° 33' 50'' n, 10° 14' 50'' e; figs. 8-9-10; appendix i). age. the tops of horizon a of the soil lying on the upper surface of the valle della casina unit and buried under the val paolaccia unit provided two dates (figs. 6-9-10, tab. 1). we think that the difference between these dates, respectively 1270 ± 70 14c yr b.p. (section 39) and 2570 ± 70 14c yr b.p. (section 49) depends on the different time of burial, which is related to their altitudinal position: the soil at a lower altitude was buried earlier. therefore, the difference observed in the ages provides a rough estimation of the average sedimentation rate (0.6 mm/yr). 44..22..44.. ddeeppoossiittss ooff uunnsseettttlleedd ssttrraattiiggrraapphhiicc ppoossiittiioonn some blocks of monogenic clast-supported conglomerates, locally passing to medium sandstone, were found along the river bed of acqua del gallo. clasts are carbonatic and the red or grey matrix is scarce. the provenance of this material is unknown. surveys carried out by the aem milano at the passo di fraele detected conglomerate layers embedded in the gravel. moreover a conglomerate layer a few centimetre thick is embedded in the sequence of clay, gravel and sands along the escarpment of the val bruna fan. fig. 9 stratigraphic sections of the val paolaccia unit coming into contact with the valle della casina unit (see appendix i). sezioni stratigrafiche dell’unità della val paolaccia al contatto con l’unità della valle della casina (cfr. appendice i). 44..33.. ddeennddrroocchhrroonnoollooggyy ooff ddeebbrriiss fflloowwss the dendrogeomorphological study concerns the most recent history of the valle della casina fan. the integration of the historical, meteorological and dendrochronological data allowed us to reconstruct the following chronological sequence of debris flows in the valle della casina (fig. 11) (santilli & pelfini, 2002). the oldest dated debris flow occurred at the end of the 19th century: five trees in area (f) showed compression wood events dating back to 1888. two close dates obtained by analysing eleven trees located in channel (b), area (f) and terrace (d) are 1927-1929. this could be considered as a single episode. between 1936 and 1941 four damaged trees in areas (e) and (f) were sampled. two scars dating back respectively to 1936 and 1941, point out that probably different debris flows were responsible for them. a tree located in the secondary channel (b) was damaged in 1953. this debris flow can be connected to a flood, which occurred after heavy rain between 12th and 13th august (borgonovo, 1955). clear scars on three trees located in the secondary channels (b) and (c) witness an event that took place in 1959 (see fig. 3). the damage on a tree located in area (f) jutting out in the main channel (a) witness a debris flow in 1964 (see sample (c) in fig. 5). heavy rain occurred on june 2nd (34.2 mm) and october 8th (42.8 mm). a flood which occurred in 1978 left traces everywhere; twenty-one damaged trees, in the main channel (a), in the secondary channels (b) and (g), and on the terrace (d), were sampled. this event is witnessed by the aerial photographs: the secondary channel (g) does not appear in 1975 whereas it is present in 1981 photos. heavy rain was recorded on may 21st-22nd (57.3 mm), june 24th (58.2 mm) and july 4th-6th (84.7 mm). nine damaged trees located in the main channel (a), in the margin of area (f) and in the upper part of the terrace (d) witness an event occurred in 1986. intense precipitation took place on august 19th (43,8 mm). finally a debris flow in 1992 is documented by five trees located in the main channel (a) and on terrace (d). this event coincides with a general flood of the whole upper valtellina, that caused a lot of damage especially near bormio, where 74 mm of rain fell in 2.5 hours on july 22nd (mortara et al. 1994); the station in cancano recorded 40.8 mm on july 23rd, but heavy rain also fell on june 19th-20th (67.2 mm) and on october 6th (39.4 mm). 44..44.. ssooiill ttyyppeess four soil reference groups have been identified: leptosols, cambisols, fluvisols and regosols. leptosols. they are shallow scarcely developed soils, with an (a)c or ac profile. they develop on sandy-matrix carbonate gravel (e.g. valle della casina unit) and belong to the most represented group including four different types of soil. 1. calcari-hyperskeletic leptosols. they are made up of coarse pebbles superficial layers (ac or ca) under which fine material accumulates. the layer, which may contain a significant amount of organic matter, is very modest and discontinuous. it lacks in structure and its skeleton is mainly made up of gravel with a sandy texture matrix. its colors are usually light (hue 2,5y), the effervescence is quite strong and the ph is definitely basic. 2. calcaric leptosols. horizon o (oi + oe) is 3-4cm thick; horizon a is 10-cm thick and can assume dark colors. its structure is scarcely developed, its texture is silt loam or sandy loam, its organic carbon content is of 29-35 g/kg. the amount of carbonates is high (676-757 g/kg), therefore its reaction is basic, too (ph 7.6-8.0). 3. calcari-humic leptosols. horizon o (oi + oe) is 2-4-cm thick; horizon a is usually about 10-cm thick, has dark colors (often 10yr 2/2), a weakly or moderately marked fine or medium granular structure, is rich in rock fragments, has a sandy loam texture, a very light or null effervescence, a ph of 7.4-7.9, a 51-97-g/kg organic carbon content and a variable total carbonate content (61-595 g/kg). 196 m. santilli et alii fig. 10 stratigraphic scheme of the northwestern sector of the val paolaccia unit. schema stratigrafico del settore nordoccidentale dell ’unità della val paolaccia. 4. humi-rendzic leptosols (calcaric). horizon o (oi + oe; which is sometimes totally absent, and sometimes includes also oa) can be up to 4-cm thick; horizon a, which can sometimes be divided into two subhorizons having the characters of the mollic epipedon, is usually 10-25-cm thick, has a dark color (10yr 2/1-2/2), a weakly or moderately marked fine or medium granular structure, is rich in rock fragments, has a mostly sandy loam texture, a ph varying from 7.0 to 7.9 (seldom lower than 7.0), a very variable total carbonate content (0-569 g/kg) and a 12-130-g/kg organic carbon content. a subordinate fraction of parent material is locally siliceous (see par. 4.2.2), what reduces the carbonate content in lower horizons. cambisols. they are moderately developed soils, with an abc profile and a cambic b horizon (bw). cambisols develop on carbonate gravel, with a local subordinate siliceous fraction. these soils are little represented, and only one type of them exists. skeleti-calcaric cambisols. horizon o (oi + oe) is 1-2-cm thick; horizon a is not more than 10-cm thick, does not have very dark colors (10yr 3/2-4/3), contains few or normal rock fragments, has a moderately marked fine or medium granular structure, a sandy loam or silty loam texture, a weak or null effervescence, a variable total carbonate content (10-559 g/kg), an organic carbon content between 33 and 75 g/kg and a ph of 6.7-7.8. horizon bw is about 15cm thick, is brown (10yr 3/3-3/4), has a moderately marked medium granular structure, a loamy, sandy loam or silty loam texture, a variable effervescence, a total carbonate content between 108 and 601 g/kg, a ph of 7.8-8.0 and a 1836 g/kg organic carbon content. fluvisols. these soils have an (a)c or ac profile, and sheetflood sediments are periodically brought to them determining the stratification of the parent material and an irregular content of organic matter along the profi le. fluvisols are only located on silty deposits without rock fragments in the val paolaccia unit. calcaric fluvisols. horizon o (oi and/or oe) has little importance (0-2 cm) and can also be absent; topsoils (a horizon) have very variable characteristics: their thickness is between 2 and 25 cm, they have light (2,5y 5/2) to dark (10yr 2/2) colors, a moderate to strong effervescence, a ph of 7.5-8.3, a very scarce decarbonatation (549-946 g/kg caco3, whereas the caco3 content in the parent material is only slightly higher) and a 4-80 g/kg organic carbon content. the pedogenesis is always weak, and the dynamic characteristics of the deposits give rise to buried horizons, which can be distinguished by a weak structure and by a little accumulation of organic matter. regosols. soils with a limited development not belonging to other soil groups. anthropic regosols. these soils develop on little level areas for the charcoal production which are very widespread in this zone. the topsoil is made up of a black layer of pure charcoal, about 20cm thick, that can be divided into two levels: the upper one differs from the 197late holocene environmental evolution ... fig. 11 dating of debris flows: event-response yearly maps pointing out the position of the sampled trees used for dating purposes; the black circles indicate the specimens in which event years (corrasion scars or first developing compression wood) relevant to the same episode were identified. the box is showed in fig. 6. datazione dei debris flows: mappe annuali evento-risposta mostranti la posizione degli alberi campionati utilizzati per le datazioni; i cerchi neri indicano gli individui in cui sono stati identificati anni caratteristici relativi ad uno stesso episodio (cicatrici d’abrasione o inizio dello sviluppo di legno di compressione). l’area è mostrata in fig. 6. 198 m. santilli et alii lower one in a more acid reaction (respectively ph 5.7 and ph 7.1) and in a weak structure granted by the roots. many leptosols and cambisols show some traces of surface erosion causing a partial lack in vegetation and emerging roots on a remarkably wide surface. 44..55.. ppllaanntt ccoommmmuunniittiieess three main groups of relevés have been identified through the chord distance analysis: pioneer lithophilous communities, mountain pine-dominated woods and scrubs, and grasslands. a further distinction has been made through the presence/absence analysis. 44..55..11.. ppiioonneeeerr lliitthhoopphhiilloouuss ccoommmmuunniittiieess (tab. 2) a sparse herbaceous layer, locally associated with a thin layer of young/small pines characterizes these communities. the cover values never exceed 20-30% and are sometimes lower than 5%, according to the age and the stability of the surface. the average number of species per relevé is 18. the moss layer has a negligible cover value while lichens lack. these communities are characterized by the constant presence of hieracium staticifolium, as well as of pinus montana and of many lithophilous and basiphilous species such as trisetum distichophyllum, saxifraga caesia and athamanta cretensis. other species are sporadically present and are sometimes linked to peculiar local parameters such as a higher humidity (e.g. saxifraga aizoides). these communities belong to the association athamanto-trisetetum distichophylli (jenny-lips 1930) lippert 1966 (class thlaspietea rotundifolii br.-bl. 1926 et al. 1948, order thlaspietalia rotundifolii br.-bl. in br.bl. & jenny 1926 em seib 1977, alliance petasition paradoxi zollitsch 1966). the importance of pinus montana in this pioneer vegetation, which is instead usually found only in the most advanced stages of the association (pirola & di benedetto, 1959), must be stressed. 44..55..22.. mmoouunnttaaiinn ppiinnee wwooooddss aanndd ssccrruubbss (tab. 3) pinus montana woods and scrubs dominate the vegetation of the upper valle del gallo. the vegetative cover is nearly complete, even if in pioneer or degraded stages it can reach low values (<50%). the arboreal layer, where present, has a mean cover value of 60% and is 4 to 8-m high, while the shrubby layer (locally including juniperus nana) has a mean cover value of 35% and is 0.3 to 3-m high. the herbaceous layer is well developed and reaches a cover value of about 70%. both mosses and lichens reach a cover value of 15-20%. these communities share in general xerophitic and heliophilous characteristics and seem quite homogeneous. nevertheless, some different aspects can be observed. the syntaxonomic treatment of pinewoods is difficult because of the uncertain taxonomy of the pine itself. according to minghetti (1996), all the sampled communities should be included in the class ericopinetea horvat 1959, order erico-pinetalia horvat 1959, alliance erico-pinion mugo leibungut 1948. carex humilis and sesleria varia-dominated pinewoods. these groupings are joined together by some exclusive or preferred species like polygala chamaebuxus, calamagrostis varia and daphne striata, and by high cover values of erica carnea, carex humilis and sesleria varia. two main situations can be identified. 1. pinewoods on stabilized substrata. they are characterized by a wider cover of arboreal layer, by some species indicating that the soil has started to acidify (moneses uniflora and hieracium tenuiflorum) and by an accumulation of organic matter. according to the tree layer and erica carnea cover, the presence and abundance of vaccinium vitis-idaea and the average number of species, four different degrees of evolution can be identified: low degree of evolution. young pinewoods or scrubs, having a scanty arboreal and erica carnea cover. the average number of species is 32. intermediate degree of evolution. a thicker tree layer, a wider heather cover and a greater average number of species (35) characterize it. a group of differential table 2 synoptic table of the pioneer lithophilous communities. this table (see also tab. 3-4) shows the percentage frequencies of the most widespread species in the relevés, except in those represented by one single relevé, where the cover values are directly reported. tabella sinottica delle comunità pioniere litofile. questo tipo di tabella (cfr. anche tab. 3-4) mostra le frequenze percentuali delle specie più diffuse nei rilievi, eccetto nelle tipologie con un solo rilievo, dove sono direttamente riportati i valori di copertura. species, some of which are linked to grasslands, is present; the main species distinguishing this community from the previous one is vaccinium vitisidaea. – cowberry-dominated. it is characterized by the dominance of vaccinium vitis-idaea and by a lower average number of species (26). 2. regressive stages due to the soil erosion: the marked soil erosion causes a reduction in the arboreal cover to the advantage of the shrubby one. near the typical species of pinewoods grow more heliophilous species linked to thinner communities like carlina acaulis, senecio abrotanifolius and thymus polytrichus. the average number of species rises to 40. all these communities are similar to the association erico carneae-pinetum prostratae zöttl 1951, with a particular reference to the subassociation caricetosum humilis br.-bl. 1939 rhododendron hirsutum-dominated pinewood. it is really different for the dominant role of rhododendron hirsutum in the shrubby layer, for the scanty cover of vaccinium vitis-idaea and for the low floristic richness (17 species) mainly due to the disappearance of the most thermophilous species. the herbaceous layer is sparse and dominated by heather only. this kind of vegetation can only be found on slopes facing northward and can be ascribed to the association rhododendro hirsuti-pinetum prostratae zöttl 1951. pinewoods growing on screes. the presence of lithophilous species make these coenoses similar to the pioneer herbaceous ones growing on early developed soils. two kinds of pinewoods can grow on screes: one is characterized by scrubby pines growing on young surfaces, and the other one represents a former pinewood buried by low energy debris flows. these communities have an uncertain syntaxonomic treatment and can be considered as a transition between athamanto-trisetetum and primary stages of erico-pinetum. 44..55..33..ggrraassssllaannddss (tab. 4) grasslands are very rich in species (the average number of species per relevé is 52). the herbaceous layer is almost continuous but often not very thick, probably because of the low cover value of grasses (mainly festuca nigrescens and sesleria varia) compared to the rosette-shaped plants (plantago alpina, cirsium acaule and carlina acaulis). grasslands include the most acidophilous and the least xerophilous communities in the studied area and can be all regarded as pastures. although all the grasslands share a high cover value of sesleria varia, two main communities, growing on different substrata, can be distinguished; some transition stages can also be observed. poa alpina and festuca nigrescens grasslands. these communities grow on fan gravelly deposits and are the richest in species (up to 68 per relevé). grasses and sedges (sesleria varia, poa alpina, festuca nigrescens, carex sempervirens and 199late holocene environmental evolution ... table 3 synoptic table of the mountain pine woods and scrubs. the synoptic tables point out only the main communities and not those belonging to an inferior rank which are instead relevant as concerns the dynamic aspects. tabella sinottica dei boschi e degli arbusteti a pino montano. le tabelle sinottiche evidenziano solo le comunità principali e non quelle di rango inferiore, che sono invece importanti per gli aspetti dinamici. 200 m. santilli et alii table 4 synoptic table of the grasslands. even though androsace chamaejasmae is widespread it is not present in the table because of its premature disappearance during the vegetative season. tabella sinottica dei pascoli. nonostante la diffusa presenza, androsace chamaejasmae non compare nella tabella per via della sua precoce scomparsa durante la stagione vegetativa. elyna myosuroides) have very high cover values. some species (e.g. luzula multiflora, elyna myosuroides and avenella flexuosa) show a soil acidification and/or an accumulation of organic matter. these coenoses can be included in the class seslerietea albicantis oberd. 1978 corr. oberd. 1990 (mucina et al., 1993) and probably be referred to seslerieto-semperviretum br.-bl. 1926 (alliance seslerion coeruleae br.-bl. in br.-bl. & jenny 1926). however, species belonging to different syntaxa (in particular the acidophilous taxa) can also be present thus making the syntaxonomic and synecological treatments difficult. cirsium acaule and plantago alpina grasslands. these communities grow on the silty deposits in the val paolaccia unit, have a lower floristic richness (30-40 species per relevé) and a less continuous structure, where grasses and sedges play a less important role. the dominant or significant species are cirsium acaule, carex flacca and plantago alpina. the syntaxonomic classification is very difficult in this case, too. carex flacca regressive stage. where the erosion prevails (see fig. 8) grassland species are replaced by other species as tussilago farfara and carex flacca, which become dominant. pine settled over grasslands. even if these communities share many species with the grasslands of silty deposits, the sparse tree layer allows the pine wood species as erica carnea to grow and causes the majority of the heliophilous grassland species to disappear. 55.. eennvviirroonnmmeennttaall eevvoolluuttiioonn ooff tthhee uuppppeerr vvaallllee ddeell ggaalllloo 55..11.. hhoolloocceennee eevvoolluuttiioonn ooff tthhee vvaalllleeyy bboottttoomm the oldest sediments cropping out on the valley bottom are lacustrine deposits belonging to the acqua del gallo unit. the paleolake was buried by a coarsening-upward succession of clays, microturbidites, alluvial and deltaic deposits transported by the fans prograding from the tributary valleys (fig. 12). the basin had already dried up before the middle holocene (e.g. before 4710 ± 90 14c yr b.p.). this phase caused the formation of an ancient flat valley bottom (belonging to the valle della casina unit) now representing inactive portions of some fans (fig. 5; see par. 4.1); its southern part dates back at least to the iron age (2570 ± 70 14c yr b.p.), but it is probably much older (e.g. before 3910 ± 60 14c yr b.p.). later, the northern and southern sectors of the upper valle del gallo had a different evolution. after eroding the northward lacustrine threshold, creek acqua del gallo started an intense regressive erosion process which at first affected the northern sector of the valley (fig. 12). this caused the formation of deep gorges (up to 50 m) in the fans of val mora and valle della casina (and locally in the bedrock), and the dismantling of wide portions of the fans of val bruna and “valle del pizzo aguzzo”, what isolated some still existing parts of the original valley bottom (fig. 5; see par. 4.1). yet a series of important flooding phases temporary interrupted the erosion process at least since the copper age (3910 ± 60 14c yr b.p.) as testified by the val bruna subunit which is embanked in the valley bottom (figs. 5-12-13). the subunit is intercalated by buried soils documenting that it formed in successive stages, separated by significant phases of stability and some changes in the erosion direction of creek acqua del gallo (see terrace (h) in fig. 13). the southern sector of the studied area (fig. 12) was not dissected by erosion until recent years. for this reason, a thick succession of fine deposits originated by sheetfloods (val paolaccia unit) accumulated among the coalescent fans of valle della casina, “valle del 201late holocene environmental evolution ... fig. 12 stratigraphic relations of the upper valle del gallo. an ideal profile was used to show the different units at the same time. schema dei rapporti stratigrafici dell’alta valle del gallo. è stato impiegato un profilo ideale per mostrare contemporaneamente le diverse unità. pizzo aguzzo” and val paolaccia. depositional events, which were originally very frequent, prevented the settlement of vegetation (see section 2 in fig. 9 and appendix i; see par. 4.2.3). meanwhile, the regressive erosion extended southward along the river bed of acqua del gallo isolating distal portions of some fans (e.g. under the val mora road for the valle della casina fan). in the middle ages (1270 ± 70 14c yr b.p.) i t reached the val paolaccia unit, favouring the drainage and the reduction of the sedimentation rate. therefore fluvisols started to develop together with a kind of vegetation suitable to adapt to frequent burials (cirsium acaule and plantago alpina grasslands) the features of which show the persistence of vegetation during aggradation. only some parts of the fan surfaces were affected by these changes in the sedimentary activity and in the vegetation. other portions of the fans were still under an active aggradation. the formation of the middle part of the valle della casina fan went on at a high rate, at least till the late roman age (1720 ± 50 14c yr b.p.; fig. 14, tab. 1), when a phase of morphologic stability caused the formation of a soil (buried soil in section 5, figs. 6-14). since the middle ages, debris flows were instead mostly localized close to the fan apex (see buried soils in section 6, figs. 6-14; see par. 5.2) and along the main channel (a in fig. 6), its ramification (b, c, g) and the adjoining sectors (e, f, d), while its most distal part was isolated by the downcutting formed by the main channel, under the val mora road. therefore, on the whole, since the middle ages, the regressive erosion of the valley bottom is responsible for the general stabilization of many surfaces, since debris flows which were locally canalised can no more spread on the entire fan surface. 55..22.. rreecceenntt eevvoolluuttiioonn ooff tthhee vvaallllee ddeellllaa ccaassiinnaa ffaann the dendrochronological reconstruction of the debris flow sequence in the valle della casina (fig. 11) begins at the end of the 19th century because of the young age of the trees. the presence of young forests (100-200 years old) is probably due to the drastic deforestation which occurred over past centuries. the most ancient dated event happened in 1888 and involved area (f) besides the channels and area (e) (fig. 15), where it covered a part of the fan surface currently exposed downhill. later debris flows (in 1927-29 and in 1936-41) interested this area only marginally (fig. 15). the most recent episodes were mostly confined to the main channel (a), where they affected the margin of area (f), and to the secondary channels (b) and (c). the 1978 debris flow represents the most intense episode during which a new channel developed (g in fig. 6). the event, which occurred in 1986, formed the upper part of the terrace (d) (see fig. 14). the main channel (a) of the valle della casina fan constitutes the course of normal drainage, with a maximum capacity able to contain the smaller flows (e.g. 1964 and 1992), the traces of which (damaged trees and terraces) are only visible along the margins. below val mora road, scarps border the main channel so in the lower part of the fan the flows do not have any direct effect outside the river bed and can reach the river acqua del gallo. when the flows exceed the maximum flow rate in the main channel, the secondary channels 202 m. santilli et alii fig. 13 hypothetical succession of events that originated the val bruna subunit and the terrace (h): 1) ancient post-lacustrine valley bottom; 2) first downcutting phase by the river acqua del gallo; 3) dismantlement of a part of the “valle del pizzo aguzzo”fan; 4) formation of a new portion of the “valle del pizzo aguzzo” fan; 5) second downcutting phase by the river acqua del gallo; 6) new flooding on the “valle del pizzo aguzzo” fan; 7) present downcutting by the river acqua del gallo and separation of the terrace (h). ipotetica successione di eventi che avrebbe dato origine alla sottounità della val bruna e al terrazzo (h): 1) antico fondovalle post-lacustre; 2) prima fase di incisione da parte dell’acqua del gallo; 3) smantellamento di parte del conoide della “valle del pizzo aguzzo”; 4) costruzione di una nuova porzione del conoide della “valle del pizzo aguzzo”; 5) seconda fase di incisione da parte dell’acqua del gallo; 6) nuova fase di alluvionamento del conoide della “valle del pizzo aguzzo”; 7) incisione attuale dell’acqua del gallo e separazione del terrazzo (h). (b) and (c) are involved. trees slacken these lateral flows that can spread to larger surfaces, hence they do not reach the river acqua del gallo (e.g. 1927-29, 1953, 1959 and 1978). exceptional flows can sometimes form new courses when they exceed also the maximum flow rate of the secondary channels. in 1978 channel (g) originated in this way. the subsequent restoration of the main channel banks made the lateral channels inactive again. 55..33.. rreellaattiioonnss bbeettwweeeenn ssooiill aanndd vveeggeettaattiioonn aanndd ddyynnaammiicc ooff tthhee eeccoollooggiiccaall ssuucccceessssiioonn soils and vegetation of the upper valle del gallo are, in general, scarcely developed. this is probably due to five principal causes: the relatively recent age of those areas subjected to pedogenesis; the periodic burial affecting some areas; the climatic restriction due to low temperature and scanty rainfall; the effects of human deforestation during the last millennium; the extent of areas subjected to an intense soil erosion. the relations between plant communities and soils allow us to make some considerations. pioneer litophilous communities grow only on calcari-hyperskeletic leptosols. pinewoods do not show soil more developed than leptosols, even at their most advanced stages. the stage characterized by the presence of cowberry on the carex humilis and sesleria varia-dominated pinewoods occurs on humi-rendzic leptosols (calcaric); these soils locally grow under less developed vegetation together with calcaric and calcari-humic leptosols. the presence of a cambisol under a regressive stage of the carex humilis and sesleria varia-dominated pinewood suggests that pinewoods growing on skeleti-calcaric cambisols are the most developed situation found on the fans (a higher evolution degree concerning the woody vegetation can be found only locally on the slopes, out of the fans). grasslands show a close relation between plant communities and soil typologies. for example cirsium acaule and plantago alpina grasslands only occur on calcaric fluvisols while poa alpina and festuca nigrescens grasslands develop only on leptosols or locally on cambisols with a moderate degree of decarbonatation as suggested by the presence of some acidophilous species (see par. 4.5.3.). it is now possible to outline the dynamic succession of soil and vegetation. surfaces formed by different sedimentation and erosion processes are progressively colonized by vegetation and are subjected to pedogenesis as they become sufficiently stable. the ecological succession occurs on two kinds of substrate, both carbonatic, different in the grain size and originated by two sedimentary processes: gravel with a sandy matrix deriving from debris flows (valle della casina unit); silts and fine sands without skeleton deriving from sheetfloods (val paolaccia unit). a third subordinate kind of parent material is constituted by coal masses from charcoal pits. the dynamic succession on a gravelly substrate (fig. 16) starts with plant communities collected in the athamanto-trisetetum grown on calcari-hyperskeletic leptosols. under geomorphological stability, a pine scrub settles and discontinuous mosaic-like horizons o and a grow up connected with pioneer vegetation. the further soil evolution involves an increase in the fine fraction and the development of a thin horizon a (calcaric leptosols). when the mass of organic matter and the decarbonatation become significant, soils pass to a stage of calcari-humic leptosols, existing until a mollic horizon develops (humi-rendzic leptosols (calcaric)). locally a bw horizon sometimes evolving 203late holocene environmental evolution ... fig. 14 block-diagram of the hydrographic left side of the main channel (a in fig. 6) of the valle della casina fan showing the position of sections 5 and 6 and of the buried charred wood (star) dated 1720 ± 50 14c yr b.p. (tab. 1). block-diagramma del lato sinistro idrografico del canale principale (a in fig. 6) del conoide della valle della casina che mostra la posizione delle sezioni 5 e 6 e del tronco carbonizzato sepolto (asterisco) datato 1720 ± 50 anni 14c b.p. (tab. 1). into a cambic horizon (skeleti-calcaric cambisols), can originate. at the same time the development of vegetation brings about an increase in the number of species and in the ground cover until carex humilis and sesleria varia-dominated pinewoods develop, where the first acidophilous species appear. the progressive acidification of the upper horizons causes an increase in the acidophilous species, the decrease in the basiphilous ones and an increase in the tree layer and in the erica carnea cover, until the species richness decreases to the advantage of vaccinium vitis-idaea (the cowberry-dominated stage). the latter is the most developed stage of vegetation found, which probably took place after a few hundred years. the rhododendron hirsutum-dominated pinewood is mainly limited to the northward exposure. all the remaining vegetation typologies represent regressive stages or secondary vegetation. the burial caused by debris flows brings the pine-forest back to athamanto-trisetetum with a tree layer; this is probably susceptible to a rapid development due to the litter supplied by the tree cover. the surface soil erosion makes the succession regress to less developed stages because of the removal of the upper horizons and the progressive crop out of parent material; the pine-forest is thinned out and the number of heliophilous species increases. on the contrary grasslands are to be considered as secondary vegetation deriving from pine-forests deforestation. the ecological succession on a silty substrate (fig. 16) is periodically interrupted by centimetric burials caused by sheetfloods. however, the soil evolution is connected to the frequency of burial episodes, depending on the closeness of the downflow direction. soils are calcaric fluvisols, periodically rejuvenated, without a meaningful decarbonation and an organic matter accumulation. the vegetation dynamics stops to a stage of blocked evolution (cirsium acaule and plantago alpina grasslands). the morphological attributes of the dominating species indicate that this community seems to “float” on a substrate in periodic aggradation; in fact carex flacca is a stoloniferous plant while plantago alpina and cirsium acaule develop tap-roots up to 50-cm long. this reaction of the vegetation causes the common radical pedoturbation. on the contrary, where erosion is intense, substitution communities prevail (carex flacca regressive stage). whenever grasslands disappear pinus montana forms a tree layer again. 66.. ccoonncclluussiioonn during the holocene, the upper valle del gallo experienced a series of intense transformations that progressively and quickly transformed the environmental setting that became established after the retreat of the würmian glaciers. complex and still unclear erosive and depositional cycles of glacial origin formed thresholds that originated a lake, although this is a pass zone, where outflows should therefore have been facilitated. environments originally poor or without vegetation, supplied an ideal substrate for the weathering and denudation processes of the slopes, originating huge amounts of debris that water could easily mobilize and transport to the lacustrine basin. its width and depth 204 m. santilli et alii favoured a pelagic terrigenous sedimentation, than in a few thousand years progressively evolved into an alluvial and deltaic environment characterized by shallow water and finally a terrestrial environment dominated by fans mostly formed by debris f low processes. vegetation adapted finding a balance with the environmental dynamics, characterized by a high instability of the slopes causing erosion and covering processes that often determine ecological situations with a blocked or slowed down evolution. the valley setting was finally modified by human action. because of the complexity and the interaction of the various ecological components, the study of this kind of environment necessarily demanded an interdisciplinary approach. the several methods used span various temporal intervals and space scales and have different resolution power, but each of them contributed in an effective way to explain every single aspect of the environmental evolution of the examined territory, allowing the final integration and synergy of the different results obtained. this route forms in a more and more detailed way for the recent times: the geomorphological and stratigraphic researches, allowed us to reconstruct the main evolutionary stages of the whole territory during the holocene and to identify some factors controlling the ecological successions; the study of the soils and vegetation has allowed us to clarify the relations existing between the various environmental components and the adaptations to the dynamics of the geomorphological and sedimentary processes occurred during relatively recent times; finally, the dendrogeomorphological fig. 15 scheme showing area (f) and the different age sections composing it. below this area a buried soil (section 19 in fig. 6) and a buried stump in position of life were found (star) (santilli & pelfini, 2002). schema mostrante l’area (f) e le porzioni di differente età che la costituiscono. sotto quest’area è stato inoltre trovato un suolo sepolto (sezione 19 in fig. 6) e un tronco sepolto in posizione di vita (asterisco) (santilli & pelfini, 2002). study has allowed us to know the precise dating and the extent of every single debris flow that, starting from the end of the 19th century, affected one of the fans. the environmental complexity of the upper valle del gallo must be deepened further on. in spite of the great amount of data and information collected up to now, new stratigraphic sections, especially relevant to the lacustrine succession, would be necessary since they could clarify the valley evolution starting from the late-glacial period and the influence of the successive alternate phases of climatic deterioration and improvement; further surveys should concern the taxonomic position of the mountain pine, the widespread superficial erosion of pinewoods and the important role of the anthropic influence, which has been up to now only partially documented. we want to emphasize the importance of an integrated approach of different disciplines to the studies on the environment. the efforts necessary to carry out interdisciplinary studies often must be restricted to small areas; however starting from local events it is possible to make comparisons and to extrapolate results that can refer to bigger areas or be applied on a regional scale. researches carried out up to now constitute therefore a good starting point for the study of the peculiar environment of the vale del gallo, to which an elevated naturalistic value to be preserved and exploited is acknowledged. the research has been carried out with the cofinancing of murst-cofin 40%-1999 project: movimenti di massa come indicatori di cambiamenti climatici dal tardiglaciale ad oggi. national responsible prof. m. panizza, local responsible prof. g. orombelli. aacckknnoowwlleeddggeemmeennttss the authors wish to thank prof. g. orombelli of the university of milano-bicocca, for the critical revision of the manuscript, the parco nazionale dello stelvio for authorising researches in its territory and aem milano for supplying the climatic data. rreeffeerreenncceess agostoni u. (1923) i giacimenti ferriferi dell’alta valtellina. in “la miniera italiana”, published on the journal “valtellina”, issues of april 11th and 18th, 1923. alestalo j. (1971) dendrochronological interpretation of geomorphic processes. societas geographica fenniae, fennia n. 105, pp. 140. baumann f. & kaiser k.f. (1999) the multetta debris fan, eastern swiss alps: a 500-year debris flow chronology. arctic, antarctic, and alpine research, vol. 31, n. 2, pp. 128-134. berra f. (1994) stratigrafia e paleogeografia del triassico superiore delle falde ortles e quattervals (australpino superiore) in lombardia. doctorate thesis in earth sciences, istituto di geologia, università di milano, pp. 146. bonsignore g., borgo a., gelati r., montrasio a., potenza r., pozzi r., ragni u., & schiavinato g. (1969) note illustrative della carta geologica d’italia alla scala 1:100.000, foglio 8 “bormio”. roma, pp. 123. borgonovo g. (1955) geologia della valle del gallo e 205late holocene environmental evolution ... fig. 16 vegetation and soil dynamic in the upper valle del gallo (regosols are not represented since they belong to point-shaped soils of anthropic origin not connected to the other typologies). dinamica della vegetazione e del suolo in alta valle del gallo (sono stati tralasciati i regosols, poiché legati a situazioni puntiformi di origine antropica non relazionate con le altre tipologie). dell’alto bacino di fraele. thesis in geology, istituto di geologia dell’università di milano. braun-blanquet j. & jenny h. (1926) vegetationsentwicklung und bodenbildung in der alpinen stufe der zentralalpen. denkschriften der schweizerischen naturforschenden gesellschaft, band lxiii, abh. 2, pp. 349. braun-blanquet j., pallmann h. & bach r. (1954) vegetation und böden der waldund zwergstrauchgesellschaften (vaccinio-piceetalia). ergebn. wiss. unters. d. schw. nat. parks, bd. 4. braun-blanquet j. (1964) pflanzensoziologie. springer verlag, wien. bull w. b. (1977) the alluvial fan environment. progress in physical geography 1(2), pp. 222270. flageollet jc, maquaire o, martin b, weber d., (1999) landslides and climatic condit ions in the barcelonnette and vars basins (southern french alps, france). geomorphology 30 (1-2): 65-78. fritts h. c. (1976) tree rings and climate. academic press, london, pp. 567. furrer e. (1914) vegetationsstudien in bormiesischen. vierteljahrschr. nat. ges. zürich, 59, pp. 78. furrer e. & longa m. (1915) flora von bormio. beih. bot. centralbl. 33(2), pp. 112. giacomini v. & pignatti s. (1955) flora e vegetazione dell’alta valle del braulio, con speciale riferimento ai pascoli d’altitudine. con carta della vegetazione all’1:12.500. fondazione per i problemi montani dell’arco alpino, milano, pubblicazione n. 12, pp. 194. giacomini v. (1960) il paesaggio vegetale della provincia di sondrio. flora et vegetatio italica, mem. n. 3, ed. gianasso, sondrio, pp. 132. govi. m., mortara. g., marchi l. & turritto o. (1994) ricerche sulle colate detritiche torrentizie (debris flow) in ambiente alpino. cnr-gndci, linea 1, rapp. 1990-91, pp. 405-420. govi. m., mortara. g. & sorzana p. f. (1985) eventi idrologici e frane. estratto da: “geologia applicata e idrogeologia”, vol. xx, parte ii, bari, pp. 359375. heikkinen o. (1994) using dendrochronology for the dating of land surfaces. in “dating in exposed and surface contexts” (ed. c. beck), university of new mexico press, albuquerque, pp. 213-235. isss-isric-fao (1998) world reference base for soil resources. world soil resources reports, 84, fao, roma. leoni b. (1953a) l’estrazione e la lavorazione del ferro in valtellina durante l’epoca medioevale. valtellina e valchiavenna, rassegna economica della provincia di sondrio, n. 11, novembre 1953, pp. 13-14. leoni b. (1953b) notizie sull’estrazione e lavorazione del ferro in valtellina tra il xvi e il xx secolo. valtellina e valchiavenna, rassegna economica della provincia di sondrio, n. 12, dicembre 1953, pp. 22-23. martina e. (1954) la geologia dell’alta valle di fraele. thesis in geology, istituto di geologia, università di milano. minghetti p. (1996) analisi fitosociologica delle pinete a pinus mugo turra del trentino (ital ia). documentes phitosociologiques, n.s., vol. xvi, camerino, pp. 461-503. mortara g., ceriani m. & laffi r. (1994) l’evento alluvionale del 22 luglio 1992 nella conca di bormio in alta valtellina. quaderni di studi e di documentazione n. 17, suppl. geam, cnr, pp. 25-33. mucina l., grabherr g. & wallnöfer s (1993) die pflanzengesellschaften österreichs. iii, wälder und gebüsche, fischer, jena, stuttgart, newyork. nichols g. (1999) sedimentology and stratigraphy. blackwell science ltd, pp. 355. osservatorio nazionale pedologico e per la qualità del suolo (1994) metodi ufficiali di analisi chimica del suolo. con commenti ed interpretazioni. ministero delle risorse agricole, alimentari e forestali, roma, pp. 207. pignatti s. (1952) introduzione allo studio fitosociologico della pianura veneta orientale. archivio botanico, 28(4): pp. 265-329. pignatti s. (1982) flora d’italia. 3 vol., edagricole, bologna. pedrotti f., orsomando e., cortini pedrotti c. (1974) carta della vegetazione del parco nazionale dello stelvio 1:50.000. ediz. amministraz. parco naz. stelvio, bormio, pp. 87. pirola a. & di benedetto g. (1959) osservazioni sul dinamismo della vegetazione e del suolo nel mugeto-ericeto del monte reit (alpi retiche bormiesi). fondazione per i problemi montani dell’arco alpino, milano, pubblicazione n. 33, catania, pp. 29. pirola a. (1973) la vegetazione. in “le alte valli dell’adda e dello spöl, un ambiente da conservare”, a cura dell’assessorato economia montana e foreste. regione lombardia. pp. 77-94. polloni g, ceriani m, crosta g, lauzi s, padovan n, (1991) rainfall and soil slipping events in valtellina. in bell dh (eds.). landslides. proc. vi int. symposium on landslides. balkema, rotterdam: 183-188. pozzi r. & giorcelli a. (1960) memoria illustrativa della carta geologica (scala 1:35.000) della regione compresa fra livigno ed il passo dello stelvio (alpi retiche). boll. serv. geol. it., vol. 81, serie g, pubbl. n. 131, milano, pp. 72. saibene c. (1973) lineamenti di geomorfologia. pp. 69-76 in le alte valli dell’adda e dello spöl, un ambiente naturale da conservare. a cura dell’assessorato all’economia montana e foreste. regione lombardia, pp. 109. salvador a. ed. (1994) international stratigraphic code. second ed., the geological society of america. sanesi g. (1977) guida alla descrizione del suolo. progetto finalizzato conservazione del suolo, c.n.r., firenze, pp. 157. santilli m, (2000) storia ed evoluzione dei conoidi dell’alta valle del gallo (alta valtellina-sondrio). studio geomorfologico, stratigrafico, dendrocronologico, pedologico e vegetazionale. thesis in natural sciences. dipartimento di scienze della terra, università di milano, italy, 273 pp. santilli m, pelfini m (2002) dendrogeomorphology and dating of debris flows in the valle del gallo, 206 m. santilli et alii central alps, italy). dendrochronologia 20 (3), pp. 269-284. shroder j.f. (1980) dendrogeomorphology: review and new techniques of tree-ring dating. progress in physical geography 4, pp. 161-188. strunk h. (1995) dendrochronologische methoden zur ermittlungen der murfrequenz und beispiele ihrer anwendung. regensburg: s. roderer verlag, pp. 196. stuiver m., reimer p. j., bard e., beck j. w., burr g. s., hughen k. a., kromer b., mccormac f. g., plicht j. & spurk m. (1998) intcal98 radiocarbon age calibration 24,000-0 cal bp. radiocarbon 40, pp. 1041-1083. van der maarel e. (1979) transformation of coverabundance values in phytosociology and its effects on community similarity. vegetatio, 39 (2), pp. 97-114. zazzi s. (1982) per una storia delle miniere di val fraele e dei forni da esse alimentati. notiziario n. 30, dicembre 1982, banca popolare di sondrio, pp. 78-83. aappppeennddiixx ii ((ddeessccrriippttiioonn ooff tthhee ssttrraattiiggrraapphhiicc sseeccttiioonnss)) sseeccttiioonn 33 - aaccqquuaa ddeell ggaalllloo uunniitt (fig.7). from the bottom upwards: 0-2,5 m: grey (2,5y 5/1) and brown (10yr 5,5/3) clayey deposits with a flat parallel lamination, made of thin massive clay laminas, less than 1-mm to 3mm thick, alternating with subordinate silty clay and silt levels. very fine grey and well sorted sand laminas are widespread too; 2,5-4,5 m: deposits mostly clayey and laminated, yellow reddish and analogous to the previous ones, but showing on average thicker laminas. locally deposits loose this flat parallel lamination and sediments assume a “mottled” aspect due to the different colors according to the grain size 4,5-5 m: centimetric layers with a flat parallel lamination mainly composed of brown clay laminas and subordinate intercalations of silt and very fine grey sands; 5-5,8 m: dark grey sand layer, the structure of which alternates between middle-sized and fine sands in a wavy parallel lamination, with subordinate millimetric grey-brown silty levels. in the upper part a layer with a low-angle cross lamination can be observed, then assuming a climbing style and gradually reconstituting the wavy parallel lamination and then again the flat parallel one; 5,8-8 m: laminated deposits mostly clayey, brown reddish, with subordinate intercalations of very fine sands 2,5y 5/2; 8-12 m: in this layer the first gravel levels can be found. these deposits tend to have a normal gradation layer, some-centimetres to 1-2-decimetres thick. each layer is composed at its base of variable thickness centimetric levels of fine and middlesized gravel with loose centimetric clasts in clear contact, often of erosive type, on the underlying finer sediments; towards the top the layer structure gradually passes to grey middle-sized and fine sands, to silt and brown reddish silty clay, in a wavy subparallel lamination at intervals little evident; 12-15,5 m: centimetric alternations of fine sands, middle-sized sands, gravelly sands and gravel with subordinate silty levels that, quantitatively, tend to reduce towards the top; 15,5-18,5 m: unselected gravelly and clast-supported sediments alternated with lens and intercalations of sands and silt sometimes containing gravel with matrix support (sometimes reddish). a rough stratification, locally passing to a cross stratification, can be observed; 18,5-22 m: proceeding towards the top unselected gravel sediments with a clastic support without sedimentary structures gradually become prevalent. at the top of the scarp there is a soil (humi-rendzic leptosols (calcaric)). sseeccttiioonn 3399 - vvaall ppaaoollaacccciiaa uunniitt (fig. 9) sequence of silt and sand deposits lacking in skeleton, organised in little differentiated sedimentary sublevels and laying upon a buried soil developed on the underlying gravel. +1-0, 0-1 cm: horizon o (oi + oe); 1-7 cm: horizon a, light grey 2,5y 5/2, with a silty loam texture and a little marked fine granular structure; numerous plant remains, many thin and middlesized roots, a clear wavy boundary, and a high effervescence. analytical data: ph 7,8, organic c 24,8 g/kg; 7-18 cm: horizon c composed of massive grey sands, 2,5y 5/2, with brown variegations,10yr 4/2, woody subhorizontal roots up to 1 cm in diameter; 18-37 cm: middle-sized to fine sands as above, well selected, but with a dark brown tonality and a clear wavy boundary; little coal fragments are widespread at the base; 37-49 cm: middle-sized grey sands with thin discontinuous brown lens including coal fragments; coal remains are scattered inside the level, too; 49-53 cm: yellow-ochre sandy silt; clear boundary; 53-57 cm: middle-sized to fine brown-grey sands with an evanescent lamination and a clear lightly wavy boundary; sparse coal fragments; 57-60 cm: horizon ab, brown 10yr 3/2, with a poor skeleton, a well marked fine granularpolyedric subangular structure, a silty loam texture, thin and middle-sized common roots, a wavy abrupt boundary and a high effervescence. analytical data: ph 8,0, organic c 34,3 g/kg. this buried soil dates back to 1270 ± 70 14c yr b.p. (tab. 1); 60-65 cm: horizon c1' composed of incoherent gravel with clasts up to 10 cm with the support of a sandy middle-sized to coarse matrix and fine gravel, grey brown 10yr 5/3, with very thin common roots, a gradual wavy boundary, a high effervescence and unaltered or only lightly altered pebbles; 65-95 cm: rough stratified gravel alternating between clastic support and matrix support up to 10 cm big, with a coarse sandy matrix, subangular pebbles, sometimes subrounded. the horizon shows a reddish matrix and reddish patinas on pebbles that at some levels form rather wide pellicles. roots are absent. 95-250 cm: fine gravel with matrix support alternating with sand lens lightly altered; in this case too the matrix of the gravelly levels shows reddish patinas that harden the sediment. 207late holocene environmental evolution ... sseeccttiioonn 4499 - vvaall ppaaoollaacccciiaa uunniitt (fig. 9) sequence of sandy and silty deposits lacking in skeleton, organised in sedimentary differentiated sublevels and laying upon a buried soil developed on the underlying gravel. 0-10 cm: horizon a, dark brown, having a weakly marked fine granular structure, a sandy loam texture, abundant roots and a clear wavy boundary; 10-30 cm: bioturbated massive fine sands, light grey with ochre tones, 2,5y 5/2; 30-33 cm: grey middle-sized to fine sands; 33-40 cm: yellowish silty fine sands, 2,5y 5/2, having a weakly marked fine polyedric subangular structure and sparse thin roots; 40-45 cm: middle-sized laminated and well selected sands, 2,5y 4/2; 45-51 cm: sandy silt with fine sand, brown-yellowish, 2,5y 5/3; 51-56 cm: middle-sized to fine laminated yellowish sands, 2,5y 5/2; 56-66 cm: massive fine sands with a weakly marked lamellar structure, grey, 2,5y 4/2, with sparse roots and a clear boundary; 66-75 cm: fine sand sandy silt, yellow-brown, 10yr 5/3, having a moderately marked middle polyedriclamellar structure; 75-93 cm: yellowish fine sand sandy silt, 2,5y 5/3, having a weakly marked polyedric-lamellar structure; 93-101 cm: grey middle-sized sands, 2,5y 4/2; 101-123 cm: weakly sandy silt with fine sand, with colors zoned between yellow and yellow-brown, and a very weakly marked lamellar structure; 123-129 cm: middle-sized grey sands; clear boundary; 129-140 cm: yellow-brown weakly sandy silt with fine sand, a weakly marked lamellar structure and a clear boundary; 140-145 cm: horizon ab 10yr 4/3, with a well marked middle polyedric angular structure, a clayey silty loam texture, a high effervescence, a poor skeleton on the surface, more abundant at the base of the horizon, where it gradually passes to the underlying horizon. analytical data: ph 8,0, organic c 28,5 g/kg. this buried soil dates back to 2570 ± 70 14c yr b.p. (tab. 1); 145-160 cm: altered gravel in a sandy matrix 10yr 5/4 altered too; patinated pebbles altered on the surface, patinas having the same color as the soil, little marked fine granular structure. sseeccttiioonn 22 - vvaall ppaaoollaacccciiaa uunniitt (fig. 9) sequence entirely composed of sandy and silty fine deposits, without skeleton, organised in sedimentary sublevels. the first 90 cm differ from the remaining part because of the presence of buried horizons and organic matter. 0-10 cm: horizon ac little pedogenized composed of grey massive fine sands, 10yr 5/1,5, with very poor roots and a wavy boundary; 10-14 cm: horizon ab composed of silty sands 10yr 4/2, having a moderately marked middle-sized to fine polyedric structure and thin sparse roots; 14-18 cm: massive grey fine sands 10yr 5/1; clear wavy boundary; 18-26 cm: horizon ab' composed of fine silty sands 10yr 4/2, with brown variegations explainable as the result of radical bioturbations; well marked middle-sized to fine polyedric structure, with sparse roots, sometimes woody too, with a subhorizontal course, an irregular boundary with pedoturbation of biological origin going down to the underlying levels (up to 60 cm); 26-30 cm: massive grey fine sands as above, 10yr5/1, with a light wavy boundary; 30-34 cm: horizon ab'' composed of lightly silty fine sands 10yr 4,5/2, with a weakly marked middlesized to fine polyedric structure and a lightly wavy boundary; 34-39 cm: lens of grey sand as above, 10yr 5/1; 39-46 cm: horizon ab''' composed of fine silty sands 10yr 4,5/2, with a weakly marked medium-sized granular structure and a clear wavy boundary; presence of partially decomposed needles; 46-70 cm: grey massive fine sands, alternating with fine silty-sandy ochre levels, subhorizontal and lightly wavy; clear boundary; 70-90 cm: ochre-yellowish massive sandy silt 2,5yr 5/3, with variegations composed of small but long empty spaces sometimes filled with decomposing dark roots; in the upper part a dark brown level rich in very little coal fragments (71-72 cm) and an ochre level with sporadic millimetric coal fragments (72-77 cm) can be observed; 90-400 cm: yellowish sandy silt alternating with subordinate centimetric levels of mainly massive grey silty fine sands, with little clear-cut lamination; locally (about 130 cm) there are laminas with a normal gradation. it is a monotone succession, totally lacking in organic elements. pedogenized buried horizons have not been identified. between 200 and 400 cm sparse little shells of gastropods can be found. 208 ms. ricevuto il 23 ottobre 2001 testo definitivo ricevuto il 10 settembre 2002 ms. received: october 23, 2001 final text received: september 10, 2002 m. santilli et alii sess 2_16022011_tpr3.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 detecting and modeling active structures in northern calabria: new insights from drainage network morphometric analysis. enrico santoro1, luigi ferranti2, carmelo monaco1, frank j. pazzaglia3 & pierfrancesco burrato4 1dipartimento di scienze geologiche, università di catania, catania 2dipartimento di scienze della terra, università “federico ii”, napoli 3department of earth and environmental science, lehigh university, bethlehem (pa) 4sezione di sismologia e tettonofisica, i.n.g.v., roma corresponding author: e. santoro <enrico.santoro@hotmail.it> abstract: santoro e. et al., detecting and modeling active structures in northern calabria: new insights from drainage network morphometric analysis.(it issn 0394-3356, 2011). a detailed morphometric analysis of the drainage network on the eastern side of the pollino mountain range (northeastern calabria) was performed in order to gain new insights on the active tectonic frame, the landscape evolution state and the response time of the hydrographic network to the tectonic deformations. the uniform coastal lithology and climate allow us to isolate the tectonic signal from the fluvial morphometric analysis. previous work, based on detailed mapping and lateral correlation of ten marine terrace orders (middle pleistocene – holocene) between the pollino range and the southern border of the san nicola plain (basilicata), and on analysis of structural, geodetic, geophysical and seismic data, allowed to hypothesize the active uplift of two fault-propagation folds, along the pollino and the valsinni ridges, linked to the high-angle transpressive shear zones that affected the region since the early pleistocene. the quantitative analysis of the longitudinal profiles was performed in order to test and improve the above mentioned deformation model. linear regressions of the logarithms of channel gradient and drainage area data was used to find convexities (knickpoints) and to determine the concavity index (θ) and the steepness index (ks). based on the θ and ks values the river paleo-longitudinal profiles were reconstructed in order to correlate each knickpoint with a marine terrace and the following glacial eustatic regression. the river vertical incision rates and the along coast variation of the knickpoints elevation linked to the same glacial eustatic regression are in perfect agreement with the deformation model. the rivers that flow through the uplifting pollino and valsinni anticlines are characterized by an increase of the: 1. longitudinal gradient; 2. vertical incision rate; 3. knickpoints elevation. they react to the higher uplift rates increasing their steepness in order to gain sufficient energy to incise the river-bed and to reestablish the previous equilibrium state. the hydrographic network response time (~105 year; that is the time for the knickpoint migration through the entire basin) shows that the tectonic morphometric anomalies are linked to active landscape deformation processes. finally, the drainage network morphometric analysis has confirmed the deformation model derived from the paleo-shoreline profiles and from structural-geophysical data, suggesting that the analyzed sector of the southern apennine is still affected by a transpressional tectonic regime. riassunto: santoro e. et al., individuazione e modellazione di strutture attive in calabria settentrionale: nuove evidenze dall’analisi morfometrica del reticolo idrografico. (it issn 0394-3356, 2011). un’analisi morfometrica di dettaglio delle principali fiumare che drenano il versante orientale del pollino (calabria nordorientale) ha consentito di acquisire nuove conoscenze riguardo il quadro tettonico attivo, lo stato evolutivo del paesaggio e i tempi di risposta del sistema idrografico alle deformazioni imposte dalla tettonica. la possibilità di determinare indipendentemente i fattori di controllo di natura climatica, litologica e tettonica rende l’area di studio un ottimo banco di lavoro per l’analisi dei processi tettonici attivi attraverso l’applicazione delle tecniche morfometriche. in lavori precedenti, sulla base del rilevamento di dieci ordini di terrazzi marini (pleistocene medio – olocene), tra il versante orientale del pollino e il limite meridionale della piana di san nicola (basilicata) e di dati strutturali, geofisici, geodetici e sismici era stato ipotizzato che l’area è interessata dal sollevamento di due anticlinali di crescita, in corrispondenza delle dorsali del pollino e di valsinni, relazionate a zone di taglio transpressive, ad alto angolo e a direzione no-se, attive a partire dal pleistocene inferiore. con l’obiettivo di verificare e implementare il suddetto modello di deformazione è stata realizzata un’analisi quantitativa dei profili longitudinali delle fiumare che ha consentito di individuare numerosi knickpoint. la ricostruzione dei paleoprofili longitudinali delle valli, attraverso l’utilizzo dei parametri ks (indice della pendenza) e θ (concavità), ricavati dai grafici logaritmici area del drenaggio – gradiente, ha permesso di datare le convessità di origine eustatica (regressioni glaciali) attraverso la correlazione con i terrazzi marini. i risultati ottenuti (tassi di incisione verticale delle fiumare, variazione lungo costa dell’altezza delle convessità correlate ad uno stesso ciclo glaciale e dei parametri ks e θ) sono in perfetto accordo con il sollevamento delle suddette anticlinali. in corrispondenza di queste ultime i corsi d’acqua reagiscono ai maggiori tassi di sollevamento attraverso un aumento dei gradienti finalizzato all’acquisizione dell’energia necessaria ad erodere e attraversare la soglia tettonica in sollevamento. il risultato è un aumento dei tassi di incisione fluviale fino ad un massimo di 0,7 mm/a. i tempi di risposta del sistema idrografico (~105 anni; tempo necessario ad una convessità per migrare attraverso l’intero bacino idrografico) indicano che le anomalie morfometriche relazionabili alla tettonica sono necessariamente legate a processi di deformazione del paesaggio tuttora attivi. in definitiva, l’analisi morfometrica conferma il modello di deformazione precedentemente proposto sulla base dei profili delle antiche linee di riva e dei dati strutturali e geofisici, evidenziando che il settore di catena investigato è tuttora interessato da tettonica transpressiva. key words: morphometric analysis, knickpoints, active transpression, north-eastern calabria. parole chiave: analisi morfometrica, convessità, transpressione attiva, calabria nord-orientale. 132 134 133 the longitudinal profile of bedrock channels may yield valuable information about the landscape vertical deformation processes, the rock mass erosional strength, the eustatic cycles and the climatic factors controlling the landforms. a number of studies have been successful in the evaluation of recent deformation features using quantitative analysis of longitudinal profiles (e.g., merritts and vincent, 1989); the realization of this goal, however, remain limited to the areas were local calibration of model parameters is possible (kirby & whipple, 2001). in this study, inspired by previous results obtained through the mapping of the marine terraces and the reconstruction of the relative paleo-shorelines, we have performed a detailed morphometric analysis of the drainage network on the eastern side of the pollino mountain range (north-eastern calabria; fig. 1). the uniform coastal lithology and climate allow us to isolate the tectonic signal from the fluvial morphometric analysis. this region is located on the northeastern tip of the calabrian arc, which lies above the westerlyplunging ionian slab, and a combination of lithospheric and crustal processes concurred to rapid late quaternary uplift. ferranti et al. (2009) and santoro et al. (2009) mapped ten terrace orders up to 663 m a.s.l., correlated between the coastal slopes of pollino range across the sibari plain, facing the ionian sea side of north-eastern calabria and eastern basilicata. based on the terrace chronology, uplift along the pollino coastal range, in the last ~600 ka, occurred at an average rate of 1 mm/a, but was characterized by the alternation of more rapid (~2.2 mm/a) and slower (~0.7 mm/a) periods of displacement. besides, spatial variability in uplift rates is recorded by the deformation profile of terraces parallel to the coast, which document small-wavelength (~20 km) and amplitude (up to ~100 m) local undulations superposed to the regional uplift pattern, which is the dominant tectonic signal (santoro et al., 2009). based on the structural, geodetic, geophysical and seismic data the paleo-shorelines undulations were interpreted as fault-propagation folds linked to the transpressive shear zones, nose directed, that affected the region since the early pleistocene. this hypothesis is confirmed by the results of the numeric modelling of the shear zones cutting the coastal area where the major deformations were identified. the good match between the modelled vertical co-seismic deformation and the paleo-shorelines deformation profiles testifies that the transpressional regime was active during the middle-upper pleistocene. through an iterative comparison between the paleo-shoreline profiles and the vertical co-seismic deformation it was possible to define the geometric and kinematic fault parameters that best explain the marine terraces deformation. the final deformation model predicts the active uplift of two anticlines along the south-eastern flank of the pollino range and the valsinni ridge (hereafter named pollino and valsinni anticlines, respectively; fig. 1). the morphometric analysis was performed to test and improve the above mentioned deformation model. linear regressions of the logarithms of channel gradient and drainage area data was used to find convexities (knickpoints) and to determine, the concavity index (θ) and the steepness index (ks). the method is based on the shear-stress incision model, predicated on the hypothesis that the bedrock-channel-erosion rate (e), in volume per unit channel area, is a power-law function of basal shear stress (τb): e = kbτb a, (1) where kb is a dimensional coefficient dependent on dominant erosion process, rock resistance and sediment load and a is a positive, processdependent constant. combining the shear-stress incision model with a statement of conservation of mass, assuming that uplift and erosion are uniform in a drainage basin and solving for the river longitudinal slope is possible to write: s = ksa-θ, (2) the coefficient ks (steepness index) and the exponent θ (concavity index) are, respectively, the gradient-axis-intercept and the slope of the linear regressions through the logarithms of channel gradient and drainage area data. we limited our analysis to the bedrock channel region; the results obtained from area controlled by hillslope/colluvial or alluvial processes are, indeed, not reliable. the rivers longitudinal profiles, extracted from dem 10x10 m, were corrected averaging the elevation through a mobile 200 m window, in order to reduce the gradient data dispersion derived by dem errors. following snyder et al. (2000) and whipple (2004) we used a fixed reference concavity (θ = 0.45) in order to calculate a normalized steepness index (ksn); this permitted the comparison between channels characterized by different drainage areas (e.g., kirby et al., 2003). the ksn values increase regularly toward the pollino and valsinni anticlines; in other words, the rivers flowing through the areas that are affected by the higher uplift rates tend to establish a steeper longitudinal profile in order to have the energy sufficient to erode the uplifting tectonic barrier. several knickpoints (steeper channel segments characterized by convex-upward shapes and θ<0) were detected along the longitudinal profiles of the trunk streams. being the analyzed rivers adjusted to the sea level (drainage network base level), it is reasonable to hypothesize that some of the knickpoints are related to the glacial-interglacial quaternary cycles. to test this idea, for each detecting and modeling active structures ... 134 ms. received: testo ricevuto il knickpoint the reconstruction of the interglacial profile was performed through the ks and the θ values calculated for the respective river. an eustatic origin was considered valid if: 1. the paleolongitudinal profile crosses a marine terrace; 2. at least three knickpoints are related to the same marine terrace (same eustatic regression); 3. the knickpoints correlated to the same eustatic cycle are characterized by migration rates and positions that are in direct relationship with the landward drainage area. for some of the knickpoints the eustatic origin is confirmed by the presence of fluvial terraces aligned with the relative paleolongitudinal profiles; the terraces are, reasonably, the consequence of the erosive wave triggered by the eustatic regression and progressively transmitted to the entire drainage basin through the knickpoint landward migration. generally, the elevation of a knickpoint genetically related to an eustatic sea level regression is influenced by the drainage area (migration rate) and the trunk stream longitudinal gradient. as a consequence, holding constant the drainage area the knickpoint elevation can be influenced by gradient changes determined by differential uplift rates; the higher the uplift rate the higher the gradient and the knickpoint elevation. in the study area this theoretical prediction is perfectly confirmed: all the knickpoints related to the same marine terrace are always characterized by an increase of the elevations toward the pollino and valsinni anticlines (fig. 1) where the higher uplift rates determine a rise of the river gradients. the maximum difference in elevation between the paleo-longitudinal profiles and the present riverbed was evaluated in order to determine the mean fluvial incision rates. as forecasted by the deformation model, the rivers flowing through the pollino and valsinni anticlines are characterized by the higher incision rates (fig. 1). these streams, in order to adjust their equilibrium profile disturbed by the tectonic deformation, increase their gradient and vertically incise through their valley. finally, based on the migration rates, it was possible to determine the drainage network response time considered to be the time necessary for a convexity to migrate through the entire drainage basin. all the analyzed rivers show a low response time (~105 yr) that highlights the youthfulness of the tectonic deformation; indeed, all the tectonic signals older than 105 yr can be considered completely erased by the fluvial erosive processes. the longitudinal profile analysis have permitted to confirm the results independently reached with the marine terraces, the structural and geophysical analysis and the fault modelling, evidencing that compressional regime is still active in this sector of the southern apennines. references ferranti l., santoro e., mazzella m.e., monaco c. & morelli d. (2009) active transpression in the northern calabria apennines, southern italy tectonophysics, 476 (1-2), 226-251. kirby e., whipple k.x., tang w. & zhiliang c. (2003) – distribution of active rock uplift along the eastern margin of the tibetan plateau: inferences from bedrock channel longitudinal profiles – j. geophys. res., 108 (b4), 2217, doi: 10.1029/2001jb000861. kirby e. & whipple k. (2001) – quantifying differential rock-uplift rates via stream profile analysis – geology, 29 (5), 415-418. merritts d. & vincent k.r. (1989) – geomorphic response of coastal streams to low, intermediate and high rates of uplift, mendocino triple junction region, northern california – geol. soc. am. bull., 101, 13731388. santoro e., mazzella m.e., ferranti l., randisi a., napolitano e., rittner s. & radtke u. (2009) raised coastal terraces along the ionian sea coast of northern calabria, italy, suggest space and time variability of tectonic uplift rates quaternary international, 206, 78-101. snyder n.p., whipple k.x., tucker g.e. & merritts d.j. (2000) – landscape response to tectonic forcing: digital elevation model analysis of stream profiles in mendocino triple junction region, northern california – geol. soc. am. bull., 112, 1250-1263. whipple k.x. (2004) – bedrock rivers and the geomorphology of active orogens – ann. rev. earth planet sci., 32, 151-185. fig. 1 – knickpoints elevation and incision rates compared with the deformation model. altezze dei knickpoints e tassi di incisione fluviali comparati con il modello di deformazione. e. santoro et al. january 13, 2011 13 gennaio 2011 imp.ciaranfi_calabriano il piano calabriano neri ciaranfi1*, enrico di stefano2, fabrizio lirer3, patrizia maiorano1, maria marino1, domenico rio4, rodolfo sprovieri2, simona stefanelli1 & gianbattista vai5 * autore corrispondente <neri@geo.uniba.it> 1dipartimento di geologia e geofisica, università di bari 2dipartimento di geologia e geodesia, università di palermo 3iamc-cnr, napoli 4dipartimento di geologia, paleontologia e geofisica, università di padova 5dipartimento di scienze della terra e geologico-ambientali, università di bologna. abstract: n. ciaranfi, e. di stefano, f. lirer, p. maiorano, m. marino, d. rio, r. sprovieri, s. stefanelli & g. vai, the calabrian stage. the proposal of using the calabrian stage to indicate the lower pleistocene has been accepted by international community of quaternary scientists: the base of this stage is coincident with the gssp in the vrica section in calabria, almost coincident with the top of olduvai paleomagnetic event at 1.81 m.y. b.p. the top of the calabrian stage is conventionally located at the matuyama-brunhes magnetic reversal, whose age is 0.78 m.y. b.p. the stratigraphic interval of the calabrian is almost fully exposed in several stratigrahic sections outcropping in southern italy: in particular calabria and sicily land sections show the lowest portion of the stage, including the gssp; the youngest part of the calabrian succession is well represented in two stratigraphic sections in crotone area and in the southern apennine foredeep (lucania basin). the same stratigraphic interval has been drilled in several odp sites in southern thyrrenian and jonian seas. parole chiave: quaternario, depositi marini, cronostratigrafia. keywords: quaternary, marine sediments, chronostratigraphy. il quaternario italian journal of quaternary sciences 21(1a), 2008 23-28 il termine calabriano, introdotto nella letteratura geologica da gignoux (1910), è stato usato a lungo per indicare l’ intervallo stratigrafico più antico del quaternario: come tale compare nelle scale cronologiche di berggren & van couvering (1974), di haq & eysinga (1987). dopo l’approvazione del gssp del limite pliocene/pleistocene nella sezione di vrica in calabria (inqua, 1982; iugs, 1984), l’uso del termine calabriano, a causa della diacronia fra la base del calabriano, nella località indicata da gignoux, ed il gssp del pliocene-pleistocene di vrica, fu progressivamente abbandonato da numerosi stratigrafi italiani. questi ultimi, per indicare la porzione inferiore del quaternario, proposero di suddividere il pleistocene inferiore – complessivamente denominato selinuntiano (ruggieri & sprovieri, 1979) – utilizzando e rivisitando tre unità cronostratigrafiche già antecedentemente definite: santerniano (ruggieri & sprovieri, 1975), emiliano (ruggieri & selli, 1949) e siciliano (doderlein, 1872). questa nomenclatura, seppur largamente accettata ed utilizzata dalla comunità scientifica italiana, non ha però ricevuto alcuna formalizzazione dalla commissione internazionale di stratigrafia dell’iugs; a livello internazionale si è proseguito ad usare il calabriano per indicare il pleistocene inferiore, come è stato recentemente ribadito da gibbard et al. (2005) nella global chronostratigraphic correlation table presentata nel 2004 al congresso geologico internazionale di firenze. la commissione italiana di stratigrafia, sotto la guida di m.b. cita, a partire dal 1994, si è prefissa l’obiettivo di standardizzare la nomenclatura delle suddivisioni stratigrafiche delle successioni sedimentarie marine del quaternario (cita & castradori, 1994); con questo scopo ha proposto la definizione dei piani marini del pleistocene inferiore (calabriano), medio (ioniano) e superiore (tarentiano) in mediterraneo (cita et al., 2006). la formalizzazione del calabriano, che rappresenta il piano più antico della serie pleistocenica, è contenuta in una nota sottoposta alla stampa su episodes nel settembre del 2007 (cita et al., in press): il dibattito su questo tema è avvenuto nel corso del workshop tenutosi a rimini (fist 2007) e la proposta è stata unanimemente accettata. la base del calabriano è posta in coincidenza del gssp del pleistocene nella sezione di vrica (calabria), al tetto del livello sapropelitico e (età 1,806 ma, lourens et al., 2004), al passaggio tra gli stadi isotopici 65 e 64, circa a tetto dell’evento paleomagnetico olduvai a 1,81 ma b.p. il suo tetto è proposto in corrispondenza dell’inversione paleomagnetica matuyama/brunhes, a 0,78 ma b.p., in coincidenza con la base del sovrastante piano ioniano (cita et al., in press). la scelta di usare parametri fisici come le inversioni di polarità magnetica per individuare i limiti di piani, operata dalla comunità scientifica internazionale, è motivata dalla facilità di identificazione di questi limiti isocroni sia in successioni costituite da sedimenti marini, che rappresentate da depositi continentali, rendendo così più agevoli le correlazioni tra ambienti diversi anche a livello globale. il record sedimentario marino del pleistocene inferiore, è stato oggetto di numerosi studi condotti da dif24 ciaranfi et al. ferenti aa. sui depositi pelagici affioranti in varie località del crotonese e di diverse aree siciliane (selli, 1967; selli, 1970; pasini et al., 1975; pasini & colalongo, 1982; aguirre & pasini, 1985; bassett, 1985; hilgen, 1991; sprovieri, 1993; van couvering, 1995; lourens et al. 1996; rio et al., 1996a; 1996b; vai, 1996; 1997; lourens et al., 2004; cita et al., 2006; cita et al., in press), come anche su successioni sedimentarie marine rappresentative della parte alta del pleistocene inferiore al passaggio con i l pleistocene medio (cita & castradori, 1994; 1995; ciaranfi et al., 1996; ciaranfi et al., 1997; ciaranfi et al., 2001; d’alessandro et al., 2003; maiorano et al., 2004; capraro et al., 2005; stefanelli et al., 2005). la massima parte delle sezioni a terra (vrica, le castella, s. maria di catanzaro, singa, monte s. nicola e capo rossello, santerno e stirone) (fig. 1), storicamente rappresentative del pleistocene inferiore, contiene solo una parte della successione calabriana, con intervalli stratigrafici di vario spessore tutti caratterizzati dall’affiorare della base di questa unità cronostratigrafica. la parte superiore del calabriano è rappresentata nelle sezioni siciliane della valle del belice e di ficarazzi, che però mancano della parte più recente dell’unità cronostratigrafica, e da due sezioni (valle di manche nel crotonese, montalbano ionico nella parte meridionale dell’avanfossa appenninica, in basilicata) nelle quali è invece esposto il tetto del calabriano unitamente alla base del sovrastante ioniano. l’intervallo calabriano è stato attraversato in numerose carote recuperate nel mediterraneo (odp leg 107, 160, 161, carota kc01b) alcune delle quali sono rappresentate in fig. 1. gran parte delle sezioni a terra ora ricordate, come pure tutte le carote odp, sono state sottoposte ad accurate indagini biostratigrafiche a plancton calcareo (foraminiferi e nannofossili), di stratigrafia isotopica dell’ossigeno, stratigrafia a sapropel, tefrostratigrafia, magnetostratigrafia e di ciclostratigrafia orbitale (rio et al., 1990a, 1990b; castradori, 1993; lourens et al., 1996a; 1996b; 1998; sprovieri et al., 1998; di stefano, 1998; howell et al., 1998; kroon et al., 1998; de kaenel et al., 1999; raffi, 2002; maiorano & marino, 2004; maiorano et al., 2004; capraro et al., 2005). l’integrazione di questi metodi stratigrafici permette una precisa calibrazione temporale di queste successioni e una loro affidabile correlazione a scala globale. le due sezioni che presentano una ideale continuità stratigrafica tra la base ed il tetto del calabriano sono la sezione di vrica e la sezione di montalbano ionico. nelle due successioni sono stati riconosciuti numerosi eventi biostratigrafici e diversi livelli tefra e sapropel che, unitamente ad un’accurata stratigrafia isotopica, oltre che magnetica nella sezione di vrica, consentono di apprezzarne l’estensione e la continuità stratigrafica (fig. 2). la sezione di ficarazzi, che colma il piccolo gap rilevato tra le sezioni di vrica e di montalbano ionico, e la sezione di valle di manche in cui è stato riconosciuto il limite matuyama/brunhes, integrano il record sedimentario in terra dell’intero intervallo calabriano (fig. 2). fig.1 ubicazione delle principali sezioni mediterranee del calabriano. location of the main calabrian mediterranean sections. 25il piano calabriano f ig . 2 s e z io n i s tr a ti g ra fi c h e d e ll’ in te ro i n te rv a llo c a la b ri a n o c o rr e la te c o n i l re c o rd i s o to p ic o i n o c e a n o a tl a n ti c o ( b ic k e r t e t a l. , 1 9 9 7 ) e o c e a n o p a c if ic o ( s h a c k l e t o n e t a l. , 1 9 9 5 ; m ix e t a l. , 1 9 9 5 a , b ) e c o n q u e llo i l re c o rd a s tr o n o m ic o d i l a s k a r e t a l. (2 0 0 4 ). è i n o lt re r ip o rt a ta l a s tr a ti g ra fi a a s a p ro p e l e d i c ic li d i in s o la z io n e d a l o u r e n s e t a l. (2 0 0 4 ) e d a l o u r e n s (2 0 0 4 ). s o n o i n fi n e in d ic a te l a s tr a ti g ra fi a i s o to p ic a d i v ri c a d a l o u r e n s e t a l. ( 1 9 9 6 a ); q u e lla d i f ic a ra z z i d a v e r g n a u d -g r a z z in i e t a l. ( 1 9 9 4 ), q u e lla d i v a lle d i m a n c h e d a c a p r a r o e t a l. ( 2 0 0 5 ) e d i n fi n e q u e lla d i m o n ta lb a n o i o n ic o d a c ia r a n f i e t a l. (2 0 0 1 ). l a l it o s tr a ti g ra fi a e g li e v e n ti b io s tr a ti g ra fi c i d i v ri c a s o n o d i l o u r e n s e t a l. ( 1 9 9 6 a ) e d i l o u r e n s e t a l. ( 1 9 9 8 ); q u e lli d i f ic a ra z z i s o n o r ip re s i d a d i s t e f a n o & r io (1 9 8 1 ) e d a s p r o v ie r i (1 9 9 3 ); q u e lli d i v a lle d i m a n c h e d a m a s s a r i e t a l. (2 0 0 2 ), c a p r a r o e t a l. ( 2 0 0 5 ); i n fi n e q u e lli d i m o n ta lb a n o i o n ic o d e ri v a n o d a c ia r a n f i & d ’a l e s s a n d r o e t a l. (2 0 0 5 1 ) e d a m a io r a n o e t a l. ( 2 0 0 4 ). l e g e n d a f o : fi rs t o c c u rr e n c e , l o : la s t o c c u rr e n c e , f c o : fi rs t c o m m o n o c c u rr e n c e , l c o : la s t c o m m o n o c c u rr e n c e , r e : ri e n tr o ; td : te m p o ra n e a a s s e n z a . t h e s tr a ti g ra p h ic s e c ti o n s o f th e c a la b ri a n s ta g e a re c o rr e la te d w it h t h e i s o to p ic r e c o rd o f a tl a n ti c o c e a n ( b ic k e r t e t a l. , 1 9 9 7 ) a n d o f p a c if ic o c e a n ( s h a c k l e t o n e t a l. , 1 9 9 5 ; m ix e t a l. , 1 9 9 5 a , b ) a n d w it h t h e a s tr o n o m ic r e c o rd ( l a s k a r e t a l. , 2 0 0 4 ). t h e s a p ro p e l s tr a ti g ra p h y a n d i n s o la ti o n c y c le s ( l o u r e n s e t a l. , 1 9 9 6 b ; l o u r e n s e t a l. 2 0 0 4 ) a re a ls o r e p o rt e d . in a d d it io n t h e is o to p ic s tr a ti g ra p h y o f v ri c a s e c ti o n ( l o u r e n s e t a l. ,1 9 9 6 b ), f ic a ra zz i s e c ti o n ( v e r g n a u d -g r a z z in i, e t a l. , 1 9 9 4 ), v a lle d i m a n c h e s e c ti o n ( c a p r a r o e t a l. , 2 0 0 5 ) a n d m o n ta lb a n o i o n ic o s e c ti o n ( c ia r a n f i e t a l. , 2 0 0 1 ) a re s h o w n . l it h o s tr a ti g ra p h y a n d b io s tr a ti g ra p h ic e v e n ts a re f ro m l o u r e n s e t a l. (1 9 9 6 a ) a n d f ro m l o u r e n s e t a l. (1 9 9 8 ) in v ri c a s e c ti o n , fr o m d i s t e f a n o & r io (1 9 8 1 ) a n d s p r o v ie r i (1 9 9 3 ) in f ic a ra zz i s e c ti o n , fr o m m a s s a r i e t a l. ( 2 0 0 2 ) a n d f ro m c a p r a r o e t a l. (2 0 0 5 ) in v a lle d i m a n c h e s e c ti o n a n d fr o m c ia r a n f i & d ’a l e s s a n d r o (2 0 0 5 ) a n d f ro m m a io r a n o e t a l. (2 0 0 4 ) in m o n ta lb a n o i o n ic o s e c ti o n . l e g e n d a f o : fi rs t o c c u rr e n c e , l o : la s t o c c u rr e n c e , f c o : fi rs t c o m m o n o c c u rr e n c e , l c o : la s t c o m m o n o c c u rr e n c e , r e : re e n tr y ; td : te m p o ra ry d is a p p e a ra n c e . referenze bibliografiche aguirre e. & pasini g. (1985) the pliocene pleistocene boundary. episodes, 8, 116-120. bassett m. g. (1985) towards a "common language" in stratigraphy. episodes, 8, 87-92. berggren w.a. & van couvering j.a. (1974) the late neogene: elsevier, pp. 1-216. bickert w.b., curry & g. wefer d. (1997) late pliocene to holocene (2.6–0 m.y.) western equatorial atlantic deep water circulation: inferences from benthic stable isotopes. in: w.b. curry, n.j. shackleton, c. richter & t.j. bralower, eds: proceedings of the odp, scientific results, 154, p. 239–253. capraro l., asioli a., backman j., bertoldi r., channell j.e.t., massari f. & rio d., 2005 climatic patterns revealed by pollen and oxygen isotope records across the matuyama/brunhes boundary in central mediterranean (southern italy). geol. soc. of london, spec. public., 247, 159-182. castradori d. (1993) calcareous nannofossil biostratigraphy and biochronology in eastern mediterranean deep-sea cores. riv. it. paleont. e strat., 99, p. 107-126. ciaranfi n., marino m., sabato l., d'alessandro a. & de rosa r. (1996) studio geologico stratigrafico di una successione infra e mesopleistocenica nella parte sud-occidentale della fossa bradanica (montalbano jonico, basilicata). boll.soc. geol. it., 115, 379-391. ciaranfi n., d'alessandro a. & marino m. (1997) a candidate section for the lower-middle pleistocene boundary (apennine foredeep, southern italy). in: naiwen w. & remane j., eds: proc. 30th int. geol. congr., 11, 201-211. ciaranfi n., d'alessandro a., girone a., maiorano p., marino m., soldani d. & stefanelli s.( 2001) pleistocene sections in the montalbano jonico area and the potential gssp for early-middle pleistocene in the lucania basin (southern italy). in: ciaranfi n., pasini g., & rio d., eds, the meeting on the plio/pleistocene boundary and the lower/middle pleistocene transition: type areas and sections (bari, 25-29 september 2000). mem. di scienze geologiche, 53, 67-83. ciaranfi n. & d'alessandro a. (2005) overview of the montalbano jonico area and section: a proposal for a boundary stratotype for the lower-middle pleistocene, southern italy foredeep. quater. intern., 131, 5-10. cita m. b., capraro l., ciaranfi n., di stefano e., marino m., rio d., sprovieri r., & vai g. b. (2006) calabrian and ionian: a proposal for the definition of mediterranean stages for the lower and middle pleistocene. episodes, 29, 159-182. cita m. b., capraro l., ciaranfi n., di stefano e., lirer f., maiorano p., marino m., raffi i.,rio d., sprovieri r., stefanelli s. & vai g. b. the redifinition of the calabrian stage: a proposal. in press on episodes, 31, september 2008 cita m.b., and castradori d. ( 1994) workshop on marine sections of gulf of taranto (southern italy) usable as potential stratotypes for the gssp of the lower, middle and upper pleistocene. il quaternario, 7, 677-692. cita m.b. & castradori d.( 1995) rapporto sul workshop “marine sections from the gulf of taranto (southern italy) usable as potential stratotypes for gssp of the lower, middle and upper pleistocene”. boll. soc. geol. it., 114, 319336. d'alessandro a., la perna r. & ciaranfi n. (2003) response of macrobenthos to changes in palaeoenvironments in the lower-middle pleistocene (lucania basin, southern italy). il quaternario, 16, 167-182. de kaenel e., siesser w. g., murat a. (1999) pleistocene calcareous nannofossil biostratigraphy and the western mediterranean sapropels, sites 974 to 977 and 979. in: zahn r., comas m.c., klaus a. eds: proceedings of the ocean drilling program. scientific results, 161, p. 159181. di stefano e. (1998) calcareous nannofossil quantitative biostratigraphy of holes 963e and 963b (eastern mediterranean) . in: emeis k.-c., robertson a.h.f., richter c., camerlenghi a. eds: proceedings of the ocean drilling program, scientific results, 160, p. 99–112. di stefano e. & rio d. (1981) biostratigrafia a nannofossili e biocronologia del siciliano nella località tipo di ficarazzi (palermo-sicil ia) . acta natur.ateneo parmense, 17, 97-111. doderlein p. (1872) note illustrative della carta geologica del modenese e del reggiano. memoria iii, pp. 74. gibbard p.l., smith a.g., zalasiewicz j.a., barry t.l., cantrill d., coe a.l., cope j.c.w., gale a.s., gregory f.j., powell j.h., rawson p.f., stone p. & waters c.n. (2005) what status for the quaternary? boreas, 34, 1-6. gignoux m. (1910) sur la classification du pliocène et du quaternarie dans l' italie du sud. com. rend. acad. sciences, 150, 841-844. haq b. u. & van eysinga f. w., (1987) geological time scale. 4th revised edition. elsevier science publ. hilgen f.j. (1991) astronomical calibration of gauss to matuyama sapropels in the mediterranean and implication for the geomagnetic polarity time scale. earth & planet. science letters, 104, 226244. howell m., thunell r., di stefano e., sprovieri r., tappa e. & sakamoto t. (1998) stable isotope chronology and paleoceanographic history of sites 963 and 964, eastern mediterranean sea. in: robertson h.f., emeis k., richter c., et al. eds: proceedings of the ocean drilling program, scientific results, 160, p. 167-180. kroon d., alexander i., little m., lourens l.j., mattehewson a., robertson a.h.f. & sakamoto t. (1998) oxygen isotope and sapropel stratigraphy in the eastern mediterranean during the last 3.2 million years. in robertson h.f., emeis k., richter c. et al. eds, proc. o. d. p., scient. res.,160, 181-190. laskar j., robutel p., joutel f., gastineau m., correia a. & levrard b. (2004) a long term numerical solution for the insolation quantities of the earth. astronomy and astrophysics, 428, p. 261-285. 26 ciaranfi et al. lourens l.j. (2004) revised tuning of ocean drilling program site 964 and kc01b (mediterranean) and implications for the d18o, tephra, calcareous nannofossil, and geomagnetic reversal chronologies of the past 1.1 myr. paleoceanogr., 19, p. 3010. lourens l.j., antonarakou a., hilgen f.j., van hoof a.a.m., vergnaud-grazzini c. & zachariasse w. (1996a) evaluation of the plio-pleistocene astronomical timescale. paleoceanogr., 11, p. 391-413. lourens l.j., hilgen f.j., raffi i. & vergnaud-grazzini, c., (1996b) early pleistocene chronology of the vrica section (calabria, italia). paleoceanography, 11, 797-812. lourens l.j., hilgen f.j. & raffi i. (1998) base of large gephyrocapsa and astronomical calibration of early pleistocene sapropels in site 967 and hole 969d: solving the chronology of the vrica section (calabria, italy). in: robertson h.f., emeis k., richter c. et al. eds: proceedings of the ocean drilling program, scientific results, 160, p. 191-198. lourens l., hilgen f., shackleton n. j., laskar j. & wilson d. (2004) the neogene period, in: a geological time scale gradstein f. m., ogg j. g., smith a. g., eds: cambridge university press, cambridge, 409-440. maiorano p. & marino m. (2004) calcareous nannofossil bioevents and environmental control on temporal and spatial patterns at the early-middle pleistocene. mar. micropal., 53, 405-422. maiorano p., marino m., di stefano e. & ciaranfi n. (2004) calcareous nannofossil events in the lower-middle pleistocene transition at the montalbano jonico section and odp site 964: calibration with isotope and sapropel stratigraphy. riv. it. paleont. e strat., 110, 547-557. massari f., rio d., sgavetti m., prosser g., d'alessandro a., asioli a., capraro l., fornaciari e. &. tateo f. (2002) interplay between tectonics and glacio-eustasy, pleistocene of the crotone basin, calabria (southern italy) . boll. am. geol.soc.,114,1183-1209. mix a.c., j. le & n.j. shackleton (1995a) benthic foraminifer stable isotope stratigraphy of site 846: 0–1.8 ma. in: n.g. pisias, l.a. mayer, t.r. janecek, a. palmer-julson & t.h. van handel, eds: proceedings of the odp, scientific results, 138, p. 839–856. mix a.c., pisias n.g., rugh w., wilson j., morey a. & hagelberg t.k, (1995b) benthic foraminifer stable isotope record from site 849 (0–5 ma): local and global climate changes. in: n.g. pisias, l.a. mayer, t.r. janecek, a. palmer-julson & t.h. van handel, eds: proceedings of the odp, scientific results, 138, p. 371–412. pasini g. & colalongo m.l. (1982) status of research on the vrica section (calabria , italy), the proposed neogene/quaternary boundary-stratotipe section. in report at xi inqua congress, 1982, pitagoratecnoprint, pp. 1-75. pasini g., selli r., tampieri r., colalongo m. l., d'onofrio s., borsetti a. m. & cati, f. (1975) the vrica section. in selli, r. ed., the neogenequaternary boudary, ii symposium (bolognacrotone), excursion guide-book, 62-72. raffi i. (2002) revision of the early–middle pleistocene calcareous nannofossil biochronology (1.75–0.85 ma). marine micropaleontology, 45, p. 25–55. rio d., raffi i. & villa g. (1990a) pliocene-pleistocene calcareous nannofossil distribution patterns in the western mediterranean. in: kastens k. a, mascle j. et al. eds: proceedings of the ocean drilling program, scientific results, 107, p. 513-532. rio d., sprovieri r. & channell j. (1990b) pliocene early pleistocene chronostratigraphy and the tyrrhenian deep-sea record from site 653. in: kastens k. a, mascle j. et al. eds: proceedings of the ocean drilling program, scientific results, 107, p. 705-714. rio d., backman j. & raffi i. (1996a) calcareous nannofossil biochronology and the pliocene pleistocene boundary. in: van couvering j., ed: the pliocene-pleistocene boundary: definition and worldwide correlation: cambridge university press, pp. 63-78. rio d., channell j.e.t., massari f., poli m.s., sgavetti m., d'alessandro a. & prosser g. (1996b) reading pleistocene euastasy in a tectonically active siliciclastic shelf setting (crotone peninsula, southern italy). geology, 24, p. 743-746. ruggieri g. & selli r. (1949) il pliocene ed il post pliocene dell'emilia. giorn. geol., 20, 1-14. ruggieri g. & sprovieri r. (1975) la definizione dello stratotipo del piano siciliano e le sue conseguenze. riv. miner. siciliana, 26, 151-153. ruggieri g. & sprovieri r. (1977) ricerche sul siciliano di palermo: le argille del fiume oreto. boll. soc. geol. it., 94, 1613--1622. selli r. (1967) the plio-pleistocene boundary in italian marine sections and its relationship to continental stratigraphies. progr. in oceanogr., 4, 67-87. selli r. (1970) calabrian. giorn. geol., 37, 55-64. shackleton n.j., hall m.a. & pate d. (1995) pliocene stable isotope stratigraphy of odp site 846. in: pisias n.g., mayer, l.a. janecek t.r., palmerjulson a., van andel t.h. eds: proceedings of odp, scientific results, 138, p. 337–356. sprovieri r. (1993) pliocene-early pleistocene astronomically forced planktonic foraminifera abundance fluctuations and chronology of mediterranean calcareous plankton bio-events. riv. it. pal. e strat., 99, 371-414. sprovieri r., di stefano e., howell m., sakamoto t., di stefano a. & marino m. (1998) integrated calcareous plankton biostratigraphy and cyclostratigraphy at site 964. in: robertson h.f., emeis k., richter c., et al., eds: proceedings of the ocean drilling program, scientific results, 160, p. 155-165. stefanelli s., capotondi l. & ciaranfi n. (2005) foraminiferal record and environmental changes during the deposition of the early-middle pleistocene sapropels in southern italy. palaeogeogr., palaeoclimatol., palaeoecol., 216, 27-52. vai g.b. (1996) revisione critico-storica dei piani marini del quaternario. serv. geol. d' it., miscellanea, vi, 1-179. vai g.b. (1997) twisting or stable quaternary boundary? a perspective on the glacial late pliocene concept. quatern. intern., 40,11-22. 27il piano calabriano van couvering j.a. ( 1995) setting pleistocene marine stages. geotimes, 40, 10-11. vergnaud-grazzini c., capotondi l. & lourens l. (1994) a refined pliocene to early pleistocene chronostratigraphic frame at odp hole 653a (west mediterranean). marine geology, 117, p. 329-349. 28 ms. ricevuto il 2 aprile 2008 testo definitivo ricevuto il 17 aprile 2008 ms. received: april 2, 2008 final text received: april 17, 2008 ciaranfi et al. impaginato galli aannaalliissii aarrcchheeoossiissmmoollooggiicchhee nneell ssaannttuuaarriioo ddii eerrccoollee ddii ccaammppoocchhiiaarroo ((mmaatteessee)).. eevviiddeennzzee ddii uunn tteerrrreemmoottoo ddiissttrruuttttiivvoo ssccoonnoosscciiuuttoo eedd iimmpplliiccaazziioonnii ssiissmmootteettttoonniicchhee ppaaoolloo ggaallllii11,, ffaabbrriizziioo ggaallaaddiinnii22,, sstteeffaanniiaa ccaappiinnii33 1dipartimento della protezione civile servizio sismico nazionale, via curtatone 3, 00185 roma paolo.galli@serviziosismico.it 2cnr, istituto di geologia ambientale e geingegneria, sez. roma “tor vergata”, via del fosso del cavaliere, 00133, roma f.galadini@igag.cnr.it 3soprintendenza archeologica e per i b.a.a.a.s. di campobasso riassunto analisi archeosismologiche condotte negli scavi del santuario di ercole di campochiaro hanno consentito l’individuazione di più eventi deformativi a carico delle strutture di pertinenza del tempio sannita (iv sec. a.c-v d.c.). lo scavo di una trincea paleosismologica a ridosso delle strutture deformate ha evidenziato, inoltre, la presenza di una zona di taglio nel substrato ghiaioso, responsabile della dislocazione delle murature, dei pavimenti e della cinta in opera poligonale del santuario. i caratteri della deformazione e l’età delle strutture edilizie interessate testimoniano l’occorrenza di un primo evento di fagliazione nel iii sec. a.c. (relativo ad un terremoto sconosciuto ai cataloghi), cui sono seguiti altri eventi, probabilmente riferibili ai terremoti del 1456 e 1805. il sito è ubicato a ridosso della struttura bordiera settentrionale del massiccio del matese (faglie del m.te patalecchia-bojano-campochiaro), alla quale vengono quindi ascritte le dislocazioni rilevate nel santuario. l’attività di questo sistema di faglie, già noto in parte alla letteratura, è caratterizzato da un elevato slip-rate (0.9 mm/yr) e da tempi di ritorno che non sembrano seguire la periodicità supposta per altre strutture appenniniche. abstract archaeoseismological analyses in the hercules’s sanctuary of campochiaro (matese, central-southern apennine, italy). evidence of an unknown disruptive earthquake and seismotectonic implication. starting from the 6th cent. bc, a vast region of central-southern italy (samnium) was inhabited and dominated by the daring nation of samnites. between the 4th and 3rd cent. bc samnites and romans disputed for the hegemony of central italy, but in 290 bc the former was finally subdued by the latter. samnites raised many important sanctuaries in their land, also after the roman conquest, which remained in use until the decadence of the empire. the sanctuary of hercules near campochiaro is one of these; it was built in the 4th cent. bc, being frequented until the 4th-5th cent. ad (fig. 10). it is located close to the campochiaro fault, a roughly e-w strand of the n-matese massif structure, which borders and controls the formerlacustrine bojano basin (figg. 1, 7-8). archaeoseismological analyses performed within the sanctuary area, supported by paleoseismological trenching (figg. 11-12), geomorphological and geological surveys, allowed the identification of surface faulting of the archeological relics. buildings of the primitive phase have been displaced by a first event in the middle of the 3rd cent. bc (figg. 9, 13-15), whereas the following structures (built up over the faulted ruins of the former) show a subsequent offset, which we relate to the cumulated motion of the m=6.5~7 earthquakes of 1456 and 1805 (although we do not exclude other unknown high middle age events or the 346 ad earthquake). while the 3rd cent. bc earthquake is unknown to the italian historical catalogues, the 1456 and 1805 events are well characterized in terms of intensity datapoint distribution (figg. 5-6), and could both be related to the n-matese massif seismogenetic structure (faults of mt. patalecchia-bojano-campochiaro; fig. 1). according to our interpretation, the seismogenetic behaviour of the nmatese massif structure is rather complex, and does not follow the recurrence interval showed by other apenninic faults (2000±500 yr; see galadini and galli, 2000); on the other hand, its slip-rate (0.9 mm/yr) would be one of the highest in italy. these results suggest that the use of a poisson approach (which requires stationarity in earthquake occurrence) in seismic hazard evaluation studies could be misleading in this sector of the apenninic chain. parole chiave: archeosismologia, paleosismologia, terremoto, sismotettonica, appennino meridionale keywords: archaeoseismology, paleoseismology, earthquake, seismotectonics, southern apennine il quaternario italian journal of quaternary sciences 1155(2), 2002, 155-167 iinnttrroodduuzziioonnee la piana di bojano, da millenni crocevia di popoli e di culture, è una delle aree a più elevata sismicità della penisola italiana. tutte le civiltà che hanno eretto i propri insediamenti nella piana, prima o poi, hanno dovuto confrontarsi con la potenza distruttrice dei terremoti che si originano alle falde settentrionali del matese e con i forti risentimenti degli eventi provenienti dalle aree contermini. la sismicità della regione è in parte nota ai repertori sismologici nazionali (postpischl, 1985; camassi e stucchi, 1997; boschi et al., 1995; gruppo di lavoro cpti, 1999). questi cataloghi, raccogliendo criticamente l’imponente messe di dati, notizie e relazioni sui terremoti storici italiani (retaggio di una tradizione pluricentenaria precipuamente italiana nel campo della sismologia storica), mentre offrono una visione completa della storia sismica di ciascuna regione per quanto attiene agli ultimi secoli (almeno per i terremoti più forti), sono lacunosi ed incerti mano a mano che si proceda a ritroso nel tempo e/o si considerino gli eventi di più bassa energia (si veda stucchi e albini, 2000). ecco dunque che lo studio attraverso una finestra aperta su un passato non coperto interamente dalle fonti letterarie, quale un sito archeologico “in scavo” come quello del santuario di ercole a campochiaro, supplisce ed in parte colma gli hiatus conoscitivi della sismicità storica “convenzionale”. il riconoscimento degli effetti cosismici su vestigia archeologiche consente, 156 p. galli, f. galandini & s. capini infatti, l’individuazione ed una possibile parametrizzazione del terremoto responsabile (p.e., in termini di intensità, data e localizzazione epicentrale), permettendo quindi di arricchire e correggere il catalogo sismico, estendendolo indietro nel tempo. questo è tanto vero quanto detti effetti non siano relativi al solo scuotimento, il cui risultato, se non contestualizzato arealmente e storicamente (galadini and galli, 1999a; galadini et al., 2001; galadini e galli, 2001), non è talvolta dissimile dai dissesti indotti da altre cause (quali vetustà, eventi bellici, frane, alluvioni), ma quanto legati geometricamente alla dislocazione superficiale della faglia mobilizzata col terremoto (galli, 1999; galli and galadini, 2001). nel seguito, a valle di una sintesi del quadro sismotettonico della piana di bojano, verranno riportati i risultati preliminari delle analisi condotte nel santuario di ercole e, in particolare, quelli riguardanti la fagliazione superficiale che ha coinvolto le murature nel sito. i dati raccolti comportano una riflessione sul comportamento della struttura sismogenetica di bojano e sui limiti degli approcci convenzionali negli studi di pericolosità sismica. qquuaaddrroo ggeeoollooggiiccoo ee ssiissmmootteettttoonniiccoo ddeellll’’aarreeaa la piana di bojano (circa 500 m s.l.m) è ubicata all’interno della catena appenninica centro-meridionale, alle falde settentrionali del massiccio carbonatico dei monti del matese (2050 m, m.te miletto) ed a sud dei rilievi argilloso-arenacei del sannio. essa è parte di una conca intermontana allungata per 20 km in senso nwse, larga non più di 4 km e drenata dal f iume biferno. quest’ultimo ha però solo in parte eroso la successione alluvionale e lacustre pleistocenica che riempie i l fondo della depressione; dati di affioramento e di sottosuolo indicano infatti una potenza di circa 150-200 m per la porzione del pleistocene medio-superiore (ge.mi.na., 1963), suddivisi tra depositi di conoide e sabbie e limi lacustri alla base. in particolare, l’area di campochiaro è caratterizzata dalla presenza di una potente conoide inattiva (oltre 90 m in sondaggio; fonte erim), reincisa dal torrente la valle, e datata, nel suo ordine più recente, tra l’ultimo massimo glaciale ed il passaggio all’olocene (rispettivamente 18 ka e 10 ka; guerrieri et al., 1999). l’elemento più importante dell’area ai fini sismotettonici è il sistema di faglie bordiere settentrionali del massiccio del matese (n-matese, fig. 1). tale sistema, infatti, oltre aver guidato l’evoluzione neotettonica del bacino, è probabilmente responsabile dei principali terremoti che hanno origine nella piana. esso è composto, da nw verso se, almeno da tre faglie principali ad andamento nw-se (faglia del m.te patalecchia), wnw-ese (faglia di bojano) e wswene/e-w (faglia di campochiaro). tali faglie affiorano chiaramente lungo tutto il versante settentrionale del matese, formando a tratti una scarpata che interrompe bruscamente il profilo dei versanti e sfalsando la successione di paleosuperfici, scolpite originariamente alle stesse quote, a monte ed a valle delle faglie stesse sui versanti sudoccidentali e nordorientali del bacino di bojano (fig. 2; bosi et al., 1997). esse dislocano, inoltre, depositi lacustri datati almeno a 0.6 ma (datazione 39ar/40ar; corrado et al., 2000) ed attualmente sollevati più di 300 m sopra i corrispondenti depositi nell’attuale piana, oltre a brecce di pendio del pleistocene (faglia di bojano; fig. 3), depositi di ricaduta vulcanica (ii ciclo di roccamonfina, circa 0.3 ma, de rita and giordano, 1996: v. bosi, comunicazione personale; faglia del m.te patalecchia) e depositi alluvionali del pleistocene superiore (faglia di campochiaro; guerrieri et al., 1999). inoltre, in occasione del terremoto del 1805, diverse fonti storiche contemporanee descrissero l’apertura di fenditure lungo i versanti di bojano (faglia di bojano) e guardaregia (faglia di campochiaro); queste notizie, seppur con le dovute cautele, potrebbero testimoniare l’occorrenza di fenomeni di fagliazione superficiale e quindi l’attivazione delle suddette faglie. infine, dati provenienti dall ’elaborazione di breakout di pozzi profondi (montone et al., 1999), indicherebbero per quest’area un estensione in atto in direzione ne-sw, compatibile con la direzione e cinematica delle faglie bordiere del n-matese. fig. 1 – modello digitale del terreno nell’area del confine molisano-campano. e’ evidenziata la struttura bordiera settentrionale dei monti del matese, composta principalmente dalle faglie del m.te patalecchia, di bojano e di campochiaro. ogni faglia in affioramento si compone di diversi segmenti, non rappresentati alla scala del disegno. a questa struttura sono attribuibili i più forti terremoti con origine nella piana. a tratto sottile sono evidenziate le faglie tra pesche e angelo in grotte. la stella indica il santuario di ercole. digital elevation model of the region between molise and campania. bold lines show the northern matese massif structure, composed by the mt. patalecchia-bojano-campochiaro fault system. this system is responsible for the strong local seismicity. thin lines show the possibly antithetic faults of pesche and angelo in grotte. white star is the hercules’s sanctuary site. 157analisi archeosismologiche nel santuario ... ssiissmmiicciittàà ssttoorriiccaa come prima anticipato, l’area della piana di bojano è stata in passato zona epicentrale di terremoti catastrofici, l’ultimo dei quali è il ben documentato evento del 26 luglio 1805 (ma=6.6, io=x mcs: gruppo di lavoro cpti, 1999; circa 5500 vittime). non considerando i numerosi eventi di medio-bassa magnitudo, non capaci di produrre fagliazione superficiale, altri due terremoti distruttivi sono noti dalle fonti per aver colpito la zona in questione: quello del 346 d.c. (ben noto alla letteratura archeologica) e quello del 5 dicembre 1456. a questi vanno aggiunti gli eventi del 4 settembre 1293 e del 9 settembre 1349. il primo è noto attraverso diverse fonti primarie che attestano un elevato grado di danneggiamento a bojano, tocco caudio, isernia e sessa aurunca (boschi et al., 1995), mentre il secondo, uno dei più importanti ed estesi terremoti medievali, ebbe effetti rovinosi ad isernia ma non riporta fonti dirette per bojano o per altri paesi della piana. iill tteerrrreemmoottoo ddeell 334466 dd..cc. questo evento è identificato in genere con quello di cui fornisce notizia girolamo (ca. 340-420) nella sua rielaborazione del chronicon di eusebio di cesarea: “dyrrachium terrae motu corruit et tribus diebus ac noctibus roma nutavit plurimaeque campaniae urbes vexatae” (durazzo rovinò per un terremoto, roma traballò per tre giorni e tre notti e molte città della campania furono scosse). la datazione del terremoto, non tramandata da girolamo, si basa sull’anno di composizione del de errore profanarum religionum di giulio fìrmico materno (vissuto verso la metà del iv sec. d.c.), ovvero il 346, trattato in cui lo scrittore siracusano fa riferimento ai frequenti tremori che a quel tempo scuotevano la terra: “terram omnem circumfluunt maria, et rursus inclusa oceani ambientis circolo stringitur, caeli etiam rotonda sublimitate operitur, perflatur ventis, aspergitur pluviis, et timorem suum assidui motus tremoribus confitetur” (la terra è ovunque circondata dal mare e d’altra parte è limitata dall’abbraccio degli oceani, il cielo la ricopre con la sua sfera grandiosa, i venti la percorrono, è bagnata dalle piogge, e manifesta il suo timore con incessanti terremoti). e’ lecito ritenere che fìrmico materno avesse accennato, nel comporre il testo, ad un fenomeno recente che destava il suo interesse. la localizzazione nel sannio di tale evento deriva invece dal rinvenimento in questo territorio di iscrizioni lapidee datate alla metà del iv secolo, le quali testimoniano che la regione fu colpita da terremoti, che numerose costruzioni furono intraprese dallo stato e che le mura delle città furono restaurate. si può addirittura ipotizzare che l’avvenuta separazione del samnium dalla campania e la creazione, quindi, di una provincia samnitium potrebbe essere stata voluta per concentrare l’intervento amministrativo imperiale sulle zone disastrate dal terremoto del 346 (camodeca, 1972), la qual cosa, se vera, rafforzerebbe ulteriormente l’impressione sulla severità del terremoto. nel gruppo delle epigrafi riguardanti gli interventi di restauro nel sannio per opera di fabius maximus (primo governatore della provincia, circa 352/7) e di autonius iustinianus (probabilmente quarto governatore dopo il 375) si osserva però che il termine terrae motus è presente solo in quattro casi, ma esplicitamente leggibile solo in due (cil ix 2338, edita da camodeca, 1972, fig. 2 – schema dei rapporti altimetrici tra le paleosuperfici scolpite nei versanti di roccamandolfi, cantalupo e macchiagodena (fig. 1), lungo un ipotetico profilo sw-ne. e’ evidente una buona correlazione tra la quota delle diverse superfici nell’hangingwall della faglia del n-matese (faglia di bojano), ma non con quelle individuate nel footwall. *i trattini inclinati sono rappresentativi dell’escursione altimetrica di ciascun complesso di superfici che compongono ogni “paleosuperficie” e non ne denotano quindi né una continuità né la pendenza. sketch of the elevation relationships among pleistocene remnant surfaces carved in the hillslopes of roccamandolfi, cantalupo and macchiagodena (see fig. 1 for location), along a imaginary sw-ne trending section. the good accordance between the cantalupo and macchiagodena successions (and partly of roccamandolfi, in the bojano fault hangingwall) is not observed by the roccamandolfi’s one (bojano fault footwall). note that the sloping lines represent the altimetrical range of each complex of surfaces that compose every remnant surface; therefore, the lines do not imply any continuity or gradient of the latter. fig. 3 – veduta delle brecce pleistoceniche raddrizzare e tettonizzate lungo il versante di bojano, in prossimità della zona di faglia. view of the warped pleistocene breccia (note the quasi-vertical dip) in the bojano fault zone. 158 p. galli, f. galandini & s. capini collegata a fabius maximus e cil ix 2638, edita da buonocore, 1992, collegata ad autonius iustinianus), pur senza alcun indizio cronologico; tuttavia, giacché molte altre epigrafi (18) attestano gli interventi nel sannio di questi due governatori (gambardella, 2001), si può ragionevolmente desumere che gran parte di esse possano riferirsi allo stesso evento sismico del 346. ben più complessa è invece la localizzazione epicentrale di questo evento (ubicata nel matese sudorientale secondo gruppo di lavoro cpti, 1999) e della relativa struttura sismogenetica. l’area interessata dalle lapidi è infatti molto vasta (fig. 4) e le lapidi con l’esplicita menzione del terremoto come causa della rovina sono ubicate solo ad isernia ed alife e dubitativamente a telesia. considerando anche i dati preliminarmente acquisiti nei teatri di sessa, calvi, teano, venafro (crolli estesi e simultanei di gran parte delle strutture e delle decorazioni, compatibili con la metà del iv secolo d.c.; dati inediti degli scriventi in collaborazione con la soprintendenza di napoli e caserta) e da indizi ad atripalda-abellinum (colucci pescatori, 1986), l’ubicazione epicentrale (o di uno degli epicentri, nel caso si trattasse di un evento multiplo) del terremoto del 346 nel bacino di bojano appare non sufficientemente supportata dalle attuali conoscenze, fatto salvo che un notevole danneggiamento sia comunque derivato nella piana a seguito di questo evento. ii ll tteerrrreemmoottoo ddeell 11445566. questo evento è, insieme a quello del 1349, l’evento medievale più forte, esteso e complesso d’italia. si tratta, come per il 1349, di un evento multiplo, con più aree epicentrali sgranate lungo la catena appenninica (e quindi legate a più strutture sismogenetiche), verosimilmente almeno tre: la più meridionale nel beneventano (io=xi mcs), una intermedia nella piana di bojano (io=x-xi) ed una più settentrionale nell’area dei monti della meta e mainarde (io=x-xi; fig. 5). in particolare, lo scenario di danneggiamento dell’area di bojano risulta addirittura più grave di quello che si ripresenterà per il terremoto del 1805. furono quasi completamente distrutt i bojano, frosolone, vinchiaturo, macchiagodena, mentre subirono danni gravissimi baranello, ripamolisani, sepino, carpinone, cercepiccola, spinete, colle d’anchise, campochiaro, san massimo e molti altri. la distribuzione del danneggiamento permette inoltre di ipotizzare che la struttura responsabile dell’evento sia localizzata nella piana stessa, anche se notizie di effetti cosismici riconducibili, per esempio, a fagliazione superficiale, sono scarse e frammentarie. a questo proposito si ricorda che le notizie contenenti descrizioni semi-analitiche degli effetti di superficie compaiono nelle relazioni sui terremoti solo a partire dal 17° secolo (p.e. con i terremoti del 1627 nel gargano e del 1638 nella sila; galli and bosi, 2003). iill tteerrrreemmoottoo ddeell 11880055. l’evento del 26 luglio del 1805 è l’ultimo terremoto distruttivo che ha colpito i paesi della piana di bojano. furono quasi completamenfig. 4 distribuzione parziale dei possibili effetti del terremoto convenzionalmente riferito al 346 d.c. il simbolo dei crolli si riferisce a crolli estesi e simultanei rinvenuti prevalentemente nei teatri dei siti a cui sono riferiti, cronologicamente compatibili con la data del 346 (dati preliminari acquisiti in collaborazione con la soprintendenza di napoli e caserta, ad eccezione di peltuinum: sommella, 1989). le lapidi sono tutte riferite a restauri operati dai governatori del sannio; la t indica l’esplicita menzione del terremoto quale causa della rovina (ipotizzata a saepinum). e’ inteso che più terremoti potrebbero avere concorso a questo quadro di danneggiamento. il santuario di campochiaro è indicato dalla stella. incomplete distribution of earthquake-induced effects related to the 346 ad event. collapse symbol refers to extensive and simultaneous collapses surveyed mainly in the theatres of the named towns, that are chronologically consistent to the 346 ad date (unpublished data of the authors, gathered with the collaboration of naples and caserta superintendence, with the exception of peltuinum – abrutii region – cited by sommella, 1989). memorial stones are all referred to restoration/rebuilding promoted by samnium governors; t indicates the explicit mention of earthquake-induced damage (only hypothesized in saepinum). it is worth noting that showed damages could have been induced by more than one earthquake. the star is the campochiaro hercules’s sanctuary 159analisi archeosismologiche nel santuario ... te distrutti i paesi di baranello, frosolone, carpinone, guardiaregia, cantalupo, san polomatese e san massimo, mentre moltissimi altri nel bacino e nelle zone limitrofe subirono danni gravissimi. la distribuzione delle massime intensità (fig. 6), così come per il 1456, delinea un’area epicentrale centrata sulla piana e legata, molto probabilmente, all’attivazione della struttura bordiera del matese (faglie del m.te patalecchia-bojanocampochiaro; fig. 1) e, possibilmente, delle sue antitetiche lungo il versante sudoccidentale dei monti del sannio (es., faglie di pesche-angelo in grotte; fig. 1). come prima accennato, esistono a riguardo indicazioni provenienti da fonti primarie che evidenziano l’occorrenza di fratture e fenditure avvenute lungo i versanti settentrionali del matese, ed in particolare lungo quello di guardiaregia (faglia di campochiaro; d’onofrio, 1805; poli, 1806), e tra pesche e angelo in grotte (versante nw della piana, fortini, 1984). no), è posto su una coltre detritica calcarea depostasi ai piedi del versante carbonatico cretacico di colli della defenza (fig. 8). da dati di superficie e da sondaggio (erim) il detrito calcareo ha uno spessore nell’ordine dei 20 m ed appoggia su un substrato argilloso-marnoso, presumibilmente appartenente alla formazione tortoniana del flysch di pietraroia (tortoniano-messiniano). a valle del santuario, ed in rapporto parziale di incassamento con il detrito, affiorano i depositi alluvionali della conoide di campochiaro, interdigitati distalmente con il r iempimento lacustre f inale della piana (inizio dell’olocene secondo guerrieri et al., 1999). poco a monte del santuario affiora un tratto del liscione in calcari della faglia di campochiaro, la quale borda con continuità tutto il versante settentrionale di colli della defenza (figg. 7-8). misure strutturali effettuate lungo il piano, sino al paese di guardiaregia, evidenziano una direzione media da n80w (ad est) a n70e (ad ovest); giunta alla longitudine di campochiaro la faglia ruota gradatamente in senso antiorario e si dispone circa wsw-ene. indicatori cinematici rilevati sul piano di faglia (strie) in corrispondenza del santuario fig. 5 – distribuzione parziale delle massime intensità valutate per il terremoto del 1456 (i>viii mcs). le ellissi a tratteggio indicano le tre possibili aree epicentrali. il santuario di campochiaro è indicato dalla stella. highest intensity datapoints distribution of the 1456 earthquake (i>viii mcs). ellipses show the three possible epicentral areas. star is the hercules’s sanctuary. fig. 6 – distribuzione parziale delle massime intensità valutate per i l terremoto del 1805 (i>viii mcs). i l santuario di campochiaro è indicato dalla stella. notare come il piano quotato sia molto simile a quello della zona intermedia rappresentata nella fig. 5. highest intensity datapoints distribution of the 1805 earthquake (i>viii mcs). note the similarity of the datapoints distribution with that of the central mesoseismal area in fig. 5. star is the hercules’s sanctuary. aannaalliissii aarrcchheeoossiissmmoollooggiicchhee nneell ssaannttuuaarriioo ddii eerrccoollee ssiittuuaazziioonnee ggeeoollooggiiccaa llooccaallee. il santuario sannita di ercole, localizzato in toponimo i.g.m. civitella (f. 162 iii 160 evidenziano una componente trascorrente destra (pitch 125°). l’analisi delle fotografie aeree del volo base igm del 1954 ha permesso di individuare l’area del santuario (ancora non scavata e coperta dalla vegetazione) su di un ripiano tra la scarpata di faglia principale a monte (a direzione locale ene-wsw) ed una scarpata secondaria a valle, quest’ultima con direzione ne-sw, scolpita nelle forme del deposito detritico (fig. 8). saggi di scavo all’interno del santuario hanno permesso di constatare che lo stesso è interamente fondato su detrito calcareo composto da clasti eterometrici (ϕ 5÷20 cm) subangolosi, addensato, privo di matrice ed altamente permeabile. dall’esame delle fotografie aeree non sono invece emersi indizi di movimenti gravitativi o di erosione accelerata; l’area è, tra l’altro, densamente forestata e, dal confronto con le immagini del 1954, lo è maggiormente oggi d’allora. cceennnnii ssuullllaa ssttoorriiaa ddeell ssaannttuuaarriioo. come accennato, l’area del santuario è un cantiere di scavo in evoluzione da diversi anni ed è lungi dall’essere stata interamente scavata e studiata. tuttavia è possibile, sulla base delle emergenze sinora raccolte, ricostruire le principali tappe evolutive del sito, al fine di meglio comprendere le fasi deformative che lo hanno interessato. la prima costruzione individuata è un edificio rettangolare, presumibilmente eretto nella prima metà del iv secolo a.c. e forse già di pertinenza di un luogo di culto. a questo edificio, distrutto come vedremo in seguito, si sovrappone nel iii secolo un edificio porticato (fig. 9) che fiancheggia il percorso di ingresso all’area sacra (questo edificio porticato presuppone l’esistenza di un importante edificio di culto ubicato poco a monte, le cui tracce, a causa delle successive fasi di smantellamento e ricostruzione, non sono tuttavia ancora emerse). e’ probabile che in questa fase, o poco prima, venga anche costruita la cinta muraria in opera poligonale (sicuramente dopo il 290 a.c., fine delle guerre contro roma ed inizio di un periodo di stabilità economica e politica). a questa fase di iii secolo subentra, intorno al 130 a.c. (come suggerito dal rinvenimento di monete nelle fondazioni e bolli laterizi) un nuovo tempio con valenza di santuario territoriale della capitale dello stato (fig. 10). il santuario sopravvive, tra probabili saccheggi delle milizie di silla (89 a.c.) e crisi post-belliche, sino al tempo di augusto, quando riacquista una certa importanza, seppure forse solo a livello locale. il sito è quindi frequentato per tutto il i-ii secolo d.c., come attestato dal materiale votivo rinvenuto, così come nel iii-iv secolo, ove sembra addirittura possibile una ripresa del culto. e’ probabilmente collocato nel iv secolo, infine, l’abbandono del culto di ercole, a cui subentra un uso del sito precipuamente legato alle vie di comunicazione nella piana (ed in particolare all’attiguo passaggio del “tratturello” per allifae). iill ccoonntteessttoo ddeeffoorrmmaattiivvoo. la vicinanza del santuario di ercole alla faglia bordiera di campochiaro (poche decine di metri a sud) e la presenza a nord di una scarpata nella coltre detritica che ospita il sito (visibile nelle foto aeree i.g.m. del 1954), sono gli elementi che hanno guidato un sopralluogo nell’area cinta dalle mura poligonali. p. galli, f. galandini & s. capini fig. 7 faglia di campochiaro. piano in roccia affiorante all’interno dell’area del santuario. campochiaro fault. fault plane affecting the carbonate substratum within the hercules’s sanctuary area. fig. 8 modello digitale del terreno dell’area di campochiaro. e’ evidenziato l’andamento della faglia di campochiaro e della scarpata identificata poco a valle della stessa (linea tratteggiata). il retinato scuro evidenzia la distribuzione della conoide di campochiaro. la stella indica il sito del santuario. isoipse ogni 50 m. (elaborazione da dati altimetrici i.g.m., aut. 5410, 6/6/2001) digital elevation model of the campochiaro area. bold line is the campochiaro fault trace (bedrock fault scarp), while dotted line is the fault scarp carved in the slope-derived debris. hatched area shows the campochiaro late pleistocene-holocene alluvial fan. star is the hercules’s sanctuary. qui, grazie agli scavi archeologici, in asse alla scarpata si osserva una dislocazione delle murature degli edifici attigui all’area del tempio e, più a nord, della cinta muraria, lungo un allineamento n30e. la dislocazione ha una componente sia orizzontale (destra) che verticale, e le strutture murarie di diversa fase non appaiono dislocate della stessa entità (fig. 9). questa prima osservazione suggerisce che un primo evento di dislocazione sia avvenuto tra le varie fasi edilizie e che, anzi, possa essere stata una concausa della distruzione di un edificio e la ricostruzione di un altro. la dislocazione successiva degli edifici non è “sigillata” o vincolata da alcun’altra fase edilizia o da livelli e/o depositi storici o connessi all’attività del versante, anche se le operazioni preliminari di riesumazione delle strutture sepolte potrebbero avere eliminato eventuali livelli di sutura contenuti nella coltre superficiale. ciò implica che non si ha il termine ante quem per l’ultima dislocazione delle strutture. aannaalliissii ppaalleeoossiissmmoollooggiicchhee. al fine di verificare la natura della dislocazione delle murature ed escludere eventuali cause locali di instabilità degli edifici, quali cedimenti, sottoscavazione della fondazione, etc. (che comunque sarebbero difficilmente compatibili con la geometria, estensione e cinematica delle deformazioni, nonché con le caratteristiche geomeccaniche dell’ammasso roccioso di fondazione) è stata scavata una trincea attraverso la prosecuzione della linea di dislocazione, in un tratto dell’area del santuario privo di edifici (fig. 10). le dimensioni della trincea sono state necessariamente ridotte (3 m di lunghezza e meno di 2 m di profondità), a causa della vicinanza di importanti emergenze archeologiche e del conseguente uso di un miniescavatore dalle ridotte prestazioni. i depositi esposti sulla parete della trincea sono esclusivamente caratte161analisi archeosismologiche nel santuario ... fig. 9 veduta d’insieme degli ambienti di iv secolo a.c. (spigolo destro in alto; 1) e parte del porticato (basoli a destra; 2) e dell’edificio di iii secolo (filari a sinistra; 3) costruito sulle rasature del primo. e’ evidente la scarpata di faglia (a) che interessa l’area, dislocando le murature ed il piano di calpestio. la scarpata prosegue verso ene (sinistra), interessando altri locali e le mura di cinta in opera poligonale, e verso wsw (destra), ove è stata scavata la trincea paleosismologica (b). view of the 4th cent. bc room (1) and part of the 3rd cent. bc colonnade (sparse white stones, right side; 2), and of the 3rd cent. bc structure built over the former 4th cent. walls (3). “a” indicates the fault scarp carved within the pavement of the 4th cent. bc room. the scarp continues toward ene (left), affecting other rooms and the “opus polygonal” walls, and toward wsw (right), where we dug the paleoseismological trench (b). fig. 10 schema topografico dell’area del santuario (nord ruotato). il segmento della faglia a tratto continuo è quello direttamente investigato e visibile nella trincea paleosismologica e negli scavi archeologici negli ambienti di iv e iii secolo a.c.. a tratteggio è indicato il proseguimento a monte e valle della scarpata di faglia. i dentini e la freccia indicano il lato ribassato e il verso della componente orizzontale del movimento. notare l’andamento irregolare ed il disassamento della cinta muraria in opera poligonale nella fascia di attraversamento della faglia. il sentiero che si dirige verso sud corrisponde all’antico tratturello per allifae, dopo la sua biforcazione nella piana dal tratto principale pescasseroli-candela. sempre a sud, poco fuori carta, affiora la scarpata di faglia in roccia riportata nelle figg. 7-8. topographical sketch of the sanctuary area. bold line is the investigated sector of the fault, exposed inside the trench and in the archaeological excavations of rooms of 4th and 3rd cent. bc. dashed line is the not-excavated fault scarp. teeth on downthrown side; arrows indicates the versus of horizontal motion. it is worth noting the irregular attitude and the shift of the “opus polygonal” walls within the fault crossing-belt. few meters southward there outcrops the carbonate fault scarp shown in fig. 7. rizzati da ghiaie calcaree subangolari ed eterometriche, appartenenti al corpo detritico sviluppato lungo la fascia pedemontana. come evidenziato nelle figg. 11-12, essi sono interessati da una fascia deformativa larga pochi decimetri e contenuta da piani di taglio lungo i quali i clasti sono in parte allineati ed embricati (unità 6 in fig. 11). e’ stato possibile individuare diversi corpi ghiaiosi con caratteristiche granulometriche e tessiturali differenti (unità 1-5 in figura 11). in particolare le unità 3-5 (footwall) mostrano una buona stratificazione ed un buon grado di addensamento, oltre che una pedogenizzazione della parte alta dell’unità 3. le unità 1-2 (hangingwall) mostrano invece un assetto massivo, caotico e sono scarsamente addensate; l’unità 1 si apre a cuneo ed è caratterizzata da abbondante matrice sabbiosa. l’unità 6, come anticipato, è composta da ghiaie tettonizzate, presumibilmente di pertinenza dell’unità 3. oltre alla 6 anche le unità 3-5 e la 2 sono coinvolte nella deformazione, essendo trascinate ed uncinate nel verso del movimento. il suolo attuale rimaneggiato copre e sigilla la deformazione. la totale mancanza di livelli storici nella sezione (tutti i depositi sono sterili) lascia pensare ad una asportazione recente (naturale o più probabilmente antropica) degli orizzonti più superficiali. nel complesso, seppur non vincolata cronologicamente da nessun dato archeologico o assoluto (la natura dei depositi non ha permesso alcuna datazione assoluta, es. c14), la sezione esposta evidenzia chiaramente la presenza di un movimento tettonico che ha interessato la successione detritica; l’intensa strutturazione della fascia di deformazione e la geometria e lo spessore dei depositi nell’hangingwall lasciano ipotizzare l’occorrenza di più eventi di dislocazione. in particolare, l’unità 2 (ed anche l’unità 1, che però è elisa superiormente) rappresenta probabilmente un cuneo colluviale depositato al piede di una scarpata formatasi all’atto di un evento di fagliazione, 162 p. galli, f. galandini & s. capini fig. 11 – schema della parte centrale della trincea paleosismologica scavata trasversalmente alla fascia deformativa che disloca gli edifici connessi al tempio, in un’area a sud degli stessi. la mancanza di reperti archeologici e di depositi databili al carbonio 14 non permette di vincolare cronologicamente i movimenti presenti. la strutturazione dei depositi e la geometria tipo “colluvial wedge” dell’hangingwall è comunque indicativa di ripetuti movimenti cosismici. sketch of the central sector of the trench excavated across the deformation belt affecting the sanctuary buildings. the lack of archaeological findings and of 14c datable deposits do not allow to constrain the age of offset. warping of levels and reorienting of clasts, together with the presence of several shear planes within this narrow belt, highlight the occurrence of repeated displacement events. legend: 1, loose calcareous gravel, in abundant sandy matrix; 2, loose gravel, massive.; 3, heterometric gravel in sandy matrix, slightly pedogenized; 4, fine gravel horizon in silty-sandy matrix; 5, coarse gravel in scarce sandy matrix (brownish); 6, highly tectonized gravel, with dragged and re-oriented pebbles along the shear planes (unit 3?). fig. 12 – dettaglio della zona di faglia esposta nella trincea “paleosismologica”. i due allineamenti di frecce contengono la fascia di ghiaie interessate da piani di taglio e trascinate nel verso del movimento (notare i clasti allineati). i numeri delle unità sono gli stessi della fig. 11. (a) è l’orizzonte pedogenizzato dell’unità 3. blow-up of the fault zone excavated in the paleoseismological trench. the two arrows alignments evidence the gravels belt affected by shear planes and dragged by the fault (note dragged and re-oriented clasts). units numbers are the same of fig. 11. (a) is the pedogenized horizon within unit 3. successivamente coinvolto a sua volta e trascinato da uno o più eventi. l’età del deposito detritico pedemontano (e delle dislocazioni che lo interessano), come precedentemente accennato, è verosimilmente olocenica, mentre la sua parte sommitale, indagata dalla trincea, potrebbe appartenere alle ultime fasi di attività del versante, ad esempio a quelle legate ai disboscamenti neolitici. llee ddiissllooccaazziioonnii nneeii mmuurrii. come anticipato, l’entità della dislocazione valutata negli edifici di diversa fase non è uguale; va inoltre tenuto presente che essa è un valore cumulato, invero sommatoria di tutti gli eventi di fagliazione eventualmente occorsi dall’edificazione delle prime strutture ad oggi. la scansione temporale di questi eventi è funzione della disponibilità di livelli cronologicamente definibili interessati o sigillanti la dislocazione, nonché della conoscenza approfondita della sismicità storica della regione. il rigetto orizzontale misurato in asse alla linea di dislocazione varia tra 130 e 140 cm nell’edificio rettangolare di iv secolo a.c.. questo rigetto è comprensivo, in parte, della fascia di deformazione continua affiorante, particolarmente evidente nel muro settentrionale dell’edificio. gli scavi archeologici hanno inoltre messo in evidenza il piano di calpestio di questo edificio a cavallo della dislocazione e la “scarpata” (fig. 9, 13) che ne separa la parte nel footwall da quella nell’hangingwall. il rigetto verticale tra le due parti è di circa 130 cm. il rigetto orizzontale misurato nell’edificio sovrimposto a quello di iv secolo e fronteggiato da un portico, di cui si riconosce un tratto di crepidine (marciapiede), varia tra 50 e 80 cm nei muri e-w (fig. 14), ed è di circa 60 cm in un tratto di muro perpendicolare al primo, anche se l’esiguità dell’affioramento di quest’ultimo nel footwall non permette una valutazione precisa dell’insieme della deformazione continua. più complessa è anche la valutazione del rigetto verticale di questo edificio; confrontando le quote della soglia e della risega di fondazione sul muro settentrionale degli ambienti di fig. 9 e 13 (assunto che fossero alla stessa quota) si ottiene un valore di circa 70 cm, molto simile a quello ottenuto confrontando la quota di spiccato della base della colonna del porticato e del basolato della crepidine (75 cm; fig. 14). a nordest di questo gruppo di edifici la faglia interseca anche la mura di cinta in opera poligonale (fig.15). infatti, circa a metà del tratto sw-ne delle mura, le stesse presentano spanciature, disassamenti ed un netto mutamento della tecnica costruttiva: grossolana e con predilezione per gli allineamenti orizzontali (di blocchi di piccole dimensioni) nell’hangingwall ed accurata ed in opera poligonale nel tratto rettilineo finale nel footwall. una buona tecnica è nuovamente impiegata in prossimità della porta occidentale (fig. 10), nell’hangingwall, ma lontano dalla zone di faglia. l’angolo di incidenza tra la faglia e la cinta è molto basso ed è quindi molto difficile valutare l’entità della dislocazione. quella orizzontale è comunque superiore a 1.5 m, mentre, a causa della ricostruzione degli alzati e della loro successiva rovina, nonché della pendenza irregolare del muro (che segue, in parte, quella del versante) non vi è modo di valutare quella verticale. nel complesso il rigetto totale, risultante dalle componenti orizzontali e verticali del movimento, è rt=180 cm (fig. 16). quello relativo ai muri di iii secolo a.c. è r2=110. ne consegue che la dislocazione relativa al primo evento è r1=rt-r2=70 cm. questi rigetti sono da intendersi minimi, in quanto solo in parte tengono conto della deformazione continua a più larga scala (quale quella che potrebbe avere “registrato” un elemento esteso come, ad esempio, la cinta muraria, se diversamente orientata). aallttrrii iinnddiizzii aarrcchheeoossiissmmiiccii.. per quanto esposto nei precedenti capitoli, gli eventi di fagliazione riconosciuti nel santuario di ercole, ed in particolare il primo e sconosciuto alle fonti, devono essere riferiti a terremoti di origine locale, di elevata magnitudo (m 6.5) e forte capacità distruttiva (io x mcs). a questi vanno però sommati, nell’intervallo di esistenza del santuario, eventuali effetti dovuti al risentimento locale di forti terremoti con area epicentrale anche distante. mentre la quasi totale mancanza di alzati non permette di evidenziare alcun indizio di danneggiamento “sismico”, la presenza della monumentale ed incompiuta porta occidentale, rinvenuta in stato di crollo, e la cronologia del materiale strettamente votivo possono suggerire alcune considerazioni sulla sorte finale del santuario. innanzitutto, sia la documentazione numismatica che quella 163analisi archeosismologiche nel santuario ... fig. 13 veduta della scarpata (a, free face) nel piano di calpestio dell’edificio di iv secolo a.c., “riesumata” dagli scavi archeologici. b è il piano di calpestio dell’edificio di iv sec. a.c. c sono le mura di iv secolo a.c. view of the fault scarp (a, free face) affecting the pavement (b) of the 4th cent. bc room (c), exhumed by the archaeological excavation. clasts are the loose-stone-foundation. ceramica, dei vetri e delle lucerne testimoniano un marcato utilizzo del santuario tra il iii e iv secolo d.c., almeno sino al secondo quarto del iv secolo (monete di costantino del 325-330 d.c.), mentre l’assenza di materiale più tardo e alto medievale indica una forte ed improvvisa cesura della frequentazione. anche i vetri, ed in particolare la classe raffinata di quelli incisi a “ruota e punta”, databili tra la seconda metà del iii e il iv secolo d.c., testimoniano un perdurare del culto sino a questo momento ed un improvviso abbandono poi. a questo si aggiunga che la porta occidentale (fig. 10) è stata rinvenuta parzialmente al suolo, comprensiva della volta con i conci embricati in posizione primaria di crollo, sopra uno strato di interro molto prossimo al piano di calpestio relativo alle fasi ultime di frequentazione. ed analogamente, molto altro materiale lapideo proveniente dal sovrastante tempio è stato trovato subito al di sopra degli ultimi livelli di uso. in altre parole, quindi, il crollo simultaneo della porta in una fase ancora di uso del passaggio e la cesura nel materiale votivo indicherebbero l’occorrenza di un evento distruttivo nella seconda metà del iv secolo d.c.. in attesa di ulteriori dati di scavo, sembrerebbe lecito ipotizzare che questo evento possa essere identificato con il terremoto del 346 d.c., per il quale, come prima ricordato, sono attestati danni nella regione e, presumibilmente, anche nella vicina saepinum. ccrroonnoollooggiiaa ddeeggllii eevveennttii. per quello che concerne la possibile cronologia degli eventi deformativi, essa può essere tracciata a partire dalle emergenze relative all’edificio attiguo al porticato (fig. 9); esso fu costruito sulle rasature di quello di iv secolo e sopra un reinterro messo in opera per livellare la scarpata prodottasi nel primo evento di fagliazione. i materiali rinvenuti nel reinterro sono di iii secolo a.c. (forse entro la metà del secolo), e quindi il primo evento di fagliazione documentato è cronologicamente contenuto tra la prima metà del iv secolo (età del primo edificio fagliato) e la metà del iii secolo. e’ però ragionevole pensare che l’evento sia più prossimo all’età della ricostruzione, e quindi alla metà del iii secolo, piuttosto che a quella del primo edificio (la qual cosa avrebbe comportato un abbandono dell’area per circa un secolo, fatto questo escluso dalla continuità di frequentazione testimoniata dal materiale rinvenuto nell’area). e’ poi possibile ipotizzare che la cinta muraria, il cui rigetto non è inferiore a quello delle mura di iv secolo a.c., abbia anch’essa “registrato” questo primo evento. dal momento che le mura furono costruite dopo il 290 a.c., questo evento si potrebbe collocare nel secondo quarto del iii secolo a.c.; la cinta sarebbe stata quindi restaurata nel tratto interessato dalla deformazione da maestranze meno abili di quelle che l’avevano da poco edificata. un altro indizio indiretto proviene infine da un tesoretto disperso di monete bronzee prevalentemente campane, riferibili alla prima metà del iii secolo a.c.. nell’ipotesi (ammessa in archeosismologia) che il ritrovamento di un tesoretto testimoni l’abbandono dello stesso o per l’impossibilità di recuperarlo o per la scomparsa improvvisa di chi l’aveva nascosto, la datazione delle monete indica il termine ad quem o post quem della causa dell’abbandono, cioè nel caso specifico del possibile terremoto. l’evento o gli eventi successivi che hanno concorso all’attuale rigetto cumulato sulle strutture non hanno purtroppo alcun vincolo stratigrafico, se non il post quem dato dalla costruzione dell’edificio legato al porticato (metà del iii secolo od inizio del ii a.c.). per quanto il comportamento “caratteristico” di una faglia (schwartz e coppersmith, 1984) può non essere assunto come modello valido sempre e ovunque, la semplice osservazione dell’entità del rigetto del primo evento r1=70 cm comparata a quella totale rt=180 cm suggerisce l’occorrenza di sicuramente uno o più simili eventi di dislocazione/terremoti successivamente al primo (fig. 16). questi, per quanto ricordato nel capitolo dedicato alla sismicità storica, possono essere il terremoto del 1456, una cui area epicentrale ricade nella piana di bojano, ed il terremoto del 1805, per il quale, anzi, sono note dalle fonti storiche contemporanee informazioni su possibili effetti di fagliazione superficiale lungo la faglia di campochiaro. non è escluso, tuttavia, che altri eventi sconosciuti altomedievali (o dubitativamente quello del 346 d.c.) abbiano concorso, con entità 164 p. galli, f. galandini & s. capini fig. 14 – veduta verso est del muro meridionale dell’edificio di iv secolo a.c. (a). e’ evidente la dislocazione destra che interessa, con minore entità, anche i basoli del porticato edificato sulle rasature dell’edificio di iv secolo (b e d). notare l’uncinatura del muro di iv secolo che asseconda il trascinamento lungo il piano di dislocazione (frecce). sulla destra è visibile la scarpata prodottasi nel piano di calpestio di quest’ultimo edificio (linea tratteggiata) e quindi “cresciuta” a seguito di successivi eventi di fagliazione (c). view looking east of the southern wall of the 4th cent. bc building (a). note the horizontal (dextral) displacement which affects, with a minor offset, also the colonnade alignment (b and d). note also the warping of the 4th cent. bc walls, dragged by the fault motion (open arrows). c indicates the fault scarp affecting the pavement of the 4th cent. bc room (dashed line), which grew due to subsequent surface faulting events (c). diverse (nella fattispecie minori), al rigetto finale; come osservato lungo altre faglie (p.e. quella del fucino: galadini and galli, 1999b) il rigetto in un sito non è sempre costante da evento ad evento. inoltre, la faglia che attraversa il santuario potrebbe non essere l’espressione superficiale principale della struttura sismogenetica, registrando quindi dei rigetti non “rappresentativi” del comportamento della struttura profonda (si veda, p.e., schwartz and crone, 1985; mccalpin, 1987). ddiissccuussssiioonnee ee ccoonncclluussiioonnii il sito di ercole a campochiaro è il secondo caso in italia (vedi galadini and galli, 1999a), e tra i pochissimi nel mondo (vedi stiros, 1996; galli and galadini, 2001), per il quale sia stato evidenziato un fenomeno di fagliazione di strutture archeologiche circoscritte (i.e., edifici). l’analisi delle murature, supportata dallo studio dei rilievi topografici di dettaglio, dall’interpretazione aerofotografica e dallo scavo di una trincea paleosismologica, ha consentito, infatti, di individuare e caratterizzare la dislocazione orizzontale e verticale degli edifici di pertinenza del santuario sannita e della cinta muraria in opera poligonale; tale dislocazione, nell’ambito delle conoscenze del contesto geologico e della tettonica attiva del bacino di bojano, è riferibile al sistema di faglie bordiere del matese. in particolare, è stato riconosciuto un primo evento di fagliazione avvenuto nella prima metà del iii secolo a.c.. a questo evento, riconducibile ad un terremoto sconosciuto ai cataloghi sismici, deve essere associata un’elevata capacità di distruzione, simile a quella che accompagnò gli eventi del 1456 e 1805. a questi ultimi potrebbero invece essere riferite le successivi deformazioni che interessano il sito archeologico. questo fatto ha una diretta ed importante implicazione di carattere sismotettonico; assumendo che gli 165analisi archeosismologiche nel santuario ... fig. 15 veduta verso sud delle mura poligonali occidentali. la faglia attraversa la cinta con un basso angolo di incidenza e produce una estesa fascia di deformazione, impedendo una corretta valutazione dei rigett i . i l tratto indeformato nel footwall (sinistra) mostra la tecnica raffinata utilizzata dai primi costruttori della cinta; nell’hangingwall (destra) prevale una tecnica rozza a filari orizzontali, opera di maestranze non specializzate chiamate a restaurare il muro dislocato dall’evento della prima metà del iii secolo a.c.. la linea bianca indica la traccia del piano di faglia; le frecce suggeriscono il verso del movimento. view looking south of the western “opus polygonal” walls. the fault crosses the walls alignment with a low-angle of incidence, causing a wide deformation belt and hampering a correct evaluation of offsets. the undeformed walls built in the footwall (left) show the refined technique (polygonal stones) used by the first workers at the beginning of the 3rd cent. bc; conversely, in the hangingwall a crude technique is prevalent, due to the workers called to restore the walls displaced and ruined by the 3th cent. bc event. the white line suggests the fault plane attitude; arrows indicate the versus of relative motion. fig. 16 – schema dei rapporti stratigrafici tra le diverse fasi edilizie degli edifici a valle del santuario e loro successive dislocazioni (non in scala). sulle rasature di un ambiente di iv secolo a.c., dislocato di r1 (vedi testo) vengono innalzate altre mura ed un colonnato nel iii secolo a.c.. anche questi sono successivamente fagliati di un’entità r2, ascrivibile agli effetti cumulati dei terremoti del 1456 e 1805 o di altri eventi sconosciuti (per esempio di epoca alto medievale o, dubitativamente, dello stesso terremoto del 346 d.c.). a sinistra sono schematizzate le componenti del rigetto totale (orizzontale e verticale) per i singoli eventi (rt è il rigetto cumulato complessivo). sketch of the relationships between the 4th and 3rd cent. bc walls, and relative offsets. over the faulted and clipped ruins of the first building (offset r1), the samnites built a new room, which was later displaced by r2 (rt, total cumulative offset). note that the offset of the 4th cent. bc wall is greater than that of the 3rd cent. bc wall, this fact evidencing a faulting event between the two buildings. actually, r2 should be the cumulated offset due to the 1456 and 1805 earthquakes, which had their epicentral areas in the hangingwall of the n-matese faults system. however, we cannot exclude that other unknown seismic events contributed to the measured offset (possibly of high-middle ages, or the 346 ad earthquake that struck surely this area, but the epicenter of which is still debated). on the left, possible time history of the displacement events. eventi che hanno prodotto fagliazione nel sito di ercole siano effettivamente gli anzidetti terremoti, il comportamento sismogenetico della struttura bordiera del matese, in termini di tempi di ritorno, sarebbe assai poco costante, con due eventi simili (sensu “characteristic earthquake”, schwartz and coppersmith, 1984) separati da 1700 anni e seguiti da un terzo a soli 350 anni. anche “inserendo” l’evento del 346 d.c. (la cui area epicentrale non è però dimostrato essere nella piana di bojano) gli eventi avrebbero delle ricorrenze irregolari (600, 1100 e 350 anni). in altre parole, la periodicità che sembra caratterizzare altre strutture sismogenetiche appenniniche (2000±500 anni, galadini and galli, 2000) verrebbe completamente disattesa da quella del matese settentrionale. tuttavia, come ripetuto, a quest’ultima è associato l’evento del 1456, la cui sorgente non è esclusivamente locale, ma distribuita su più strutture sismogenetiche, esterne al bacino di bojano. pur nella ristretta visione dei fenomeni che agiscono su scale temporali ben più lunghe di quelle a noi note, è possibile ipotizzare che il 1456 sia una sorta di “fuori sequenza” nel complesso processo di accumulo e rilascio della deformazione in questo tratto appenninico. il carattere “anomalo” di questo evento è, d’altra parte, suggerito dalla sua specificità di evento multiplo ed ubiquitario per un lungo tratto della catena centro-meridionale e dalla sua vicinanza, nello spazio e nel tempo, con l’analogo sisma del 1349. si potrebbe, in altre parole, ipotizzare che il rilascio della deformazione nell’appennino centro-meridionale sia caratterizzato da forti terremoti generati da singole strutture sismogenetiche (p.e., la faglia del nmatese o quella del m.te marzano – terremoto dell’irpinia del 1980) alternati a sequenze nelle quali diverse sorgenti si attivano contemporaneamente, con possibili processi di innesco a catena di strutture contermini (vedi nostro et al., 1997). questa possibile conclusione comporta, ancora una volta, la necessità di rivedere le metodologie probabilistiche di analisi della pericolosità sismica in italia, al presente (p.e., lucantoni et al., 2001) ancorate a ipotesi di stazionarietà della sismicità e con eventi, financo i più forti, dispersi nelle zone sismogenetiche e svincolati dalle rispettive faglie. sulla base dei rigetti complessivi, invece, il rateo di movimento della struttura del matese sarebbe tra i più alti dell’appennino (vedi galadini and galli, 2000), approssimandosi infatti a 0.9 mm/yr. questo rateo, come ripetuto, è però del tutto giustificato e “testimoniato” dalla sismicità locale della piana. in definitiva, lo studio archeosismologico effettuato nel santuario di ercole ha comportato: • l’individuazione e caratterizzazione di un forte terremoto databile intorno al iii secolo a.c., sconosciuto ai cataloghi, che arricchisce il data base della sismicità storica della regione finalizzato a future valutazioni di pericolosità sismica; • l’individuazione di un evento di crollo e di cesura nella frequentazione del santuario nella seconda metà del iv secolo d.c., possibilmente riferibile agli effetti distruttivi del terremoto convenzionalmente riferito al 346, che determinò la fine della funzionalità del santuario di ercole; • la possibile identificazione della struttura sismogenetica di parte del catastrofico terremoto del 1456 con la faglia bordiera del matese; • la possibile conferma diretta dell’attivazione dello stesso sistema di faglie bordiere in occasione del terremoto del 1805; • la conseguente caratterizzazione della struttura sismogenetica del matese, in termini di periodicità e rateo di movimento; • lo spunto per la soluzione di alcuni problemi concernenti l’evoluzione architettonica e storica del sito e le possibili cause e spiegazioni di riedificazioni e dell’uso di tecniche edilizie. questo lavoro testimonia, in parte, come le potenzialità di un approccio archeosismologico nell’approfondimento delle conoscenze sulla sismicità in italia sono notevoli e ancora molto da esplorare. la ricchezza del nostro patrimonio archeologico e gli oltre due millenni da esso abbracciati rappresentano infatti una “miniera” di informazioni utili, se non uniche, nello studio della sismotettonica del nostro paese. rriinnggrraazziiaammeennttii domenico gambardella, nell’ambito di un contratto c.n.r., ha condotto un approfondimento sulle problematiche storico-archeologiche relative al terremoto del 346 d.c., al quale ci siamo riferiti. vittorio bosi ha partecipato al rilievo del sistema delle faglie bordiere del matese, fornendo dati inediti sulla stratigrafia del quaternario. questo lavoro non sarebbe stato possibile senza una stretta collaborazione tra geologi del terremoto, archeologi ed esperti di scavo della soprintendenza archeologica di campobasso e di napoli-caserta. siamo infine grati ad andrea tertulliani e ad un anonimo referee, i cui commenti e suggerimenti hanno migliorato il manoscritto originale. llaavvoorrii cciittaattii boschi e., ferrari g., gasperini p., guidoboni e., smriglio g., valensise g. (a cura di), 1995. catalogo dei forti terremoti in italia dal 461 a.c. al 1980. ing e sga, bologna 1995, 973 pp. bosi v., galadini f., galli p., giuliani r., meghraoui m., messina p., molin d., stucchi m., 1997. la definizione di schemi strutturali per finalità sismotettoniche. in: r iassunti del convegno aiqua, associazione ital iana per lo studio del quaternario; “tettonica quaternaria del territorio italiano: conoscenze, problemi ed applicazioni”, parma, 25-27 febbraio 1997, 53. buonocore m., 1992. una nuova testimonianza del rector provinciae autonius iustinianus e il macellum di saepinum, in athenaeum, 80, 484-486, pavia. camassi r. e stucchi m. (a cura di), 1997. nt4.1.1 un catalogo parametrico di terremoti di area italiana al di sopra della soglia del danno. gndt, milano, 95 pp. internet: http://emidius.itim.mi.cnr.it. camassi r. & stucchi m. (a cura di), 1998. nt4.1.1/81-92. gndt, milano, 7 pp. internet: http://emidius.itim. camodeca g., 1972. fabius maximus e la creazione della provincia del samnium, atti dell’accademia, 8822, 249-264, napoli. 166 p. galli, f. galandini & s. capini colucci pescatori g., 1986. osservazioni su abellinum tardo antica e sull’eruzione di pollena del 472, in: trembements de terre, éruption volcaniques et vie des hommes dans la campanie antique, a cura di c.a. livadie, napoli, 121-133. corrado s., di bucci d., naso g., villa i., 2000. extensional tectonics in the matese area, atti del convegno: evoluzione geologica e geodinamica dell’appennino, in memoria del prof. g. pialli, foligno 16-18 febbraio 2000. de rita d. and giordano g., 1996. volcanological and structural evolution of roccamonfina volcano (southern italy) and structural origin of the summit caldera, in: mc guire w.j., jones a.p. and neuberg j. (eds.), volcano instability on earth and other planets. geol. soc. am. spec. publ. 111100, 209-224. d’onofrio a., 1805. lettera ad un amico in provincia sul tremuoto accaduto a 2 luglio e seguito dall'eruzione vesuviana de 12 agosto del corrente 1805, napoli. erim, ente risorse idriche molise, casmez: sintesi delle indagini eseguite alle sorgenti del biferno. relazione interna non datata. fortini p., 1984. delle cause de’ terremoti e loro effetti, danni di quelli sofferti dalla città d’isernia fino a quello de’ 26 luglio 1805, (manoscritto del 18051806 attribuito a pasquale fortini), a cura di t. sardelli, marinelli editore, isernia, 65 pp. galadini f. and galli p., 1996. paleoseismology related to deformed archaeological remains in the fucino plain. implications for subrecent seismicity in central italy, annali di geofisica, 3399, 5, 925-940. galadini f. and galli p., 1999a. paleoseismology related to the displaced roman archaeological remains at egna (adige valley, northern italy), tectonophysics, 330088, 171-191. galadini f. and gall i p., 1999b. the holocene paleoearthquakes on the 1915 avezzano earthquake faults (central italy): implications for active tectonics in central apennines, tectonophysics, 330088, 143-170. galadini, f. and galli p., 2000. active tectonics in the central apennines (italy) – input data for seismic hazard assessment, natural hazards, 2222, 202223. galadini f., galli p., molin d., ciurletti g., 2001. searching for the source of the 1117 earthquake in northern italy: a multidisciplinary approach, t. glade et al. (eds.), the use of historical data in natural hazard assessments, kluwer academic publisher, 3-27. galadini f. e gall i p., 2001. gruppo di lavoro "archeosismologia", aiqua, associazione italiana per lo studio del quaternario, http://aiqua.irtr.rm.cnr.it/archeo.html galli p., 1999. active tectonics along the wadi arabajordan valley transform fault, journal of geophysical research, 110044, 2777-2796. galli p. and bosi v., 2002. the catastrophic 1638 calabrian earthquakes (southern italy). new insight from paleoseimologic investigation, journal of geophysical research, 108, b1, 10.1029/2002jb01713. galli p. and galadini f., 2001. surface faulting on archaeological relics. a review of case histories from dead sea to alps, tectonophysics, 333355, 291312. gambardella d., 2001. il terremoto del 346 d.c. alla luce della ricerca storico-archeologica, relazione inedita cnr-irtr, roma, 30 pp. ge.mi.na., 1963. ligniti e torbe dell’italia continentale, ilte, torino, 319 pp. gruppo di lavoro cpti, 1999. catalogo parametrico dei terremoti italiani. ing, gndt, sga, ssn, bologna 1999, 92 pp. guerrieri l., scarascia g., vittori e., 1999. analisi stratigrafica e geomorfologica della conoide tardo-quaternaria di campochiaro ed implicazioni per la conca di bojano in molise, il quaternario, 1122, 237247. lucantoni a., bosi v., bramerini f., de marco r., lo presti t., naso g. e sabetta f., 2001. il rischio sismico in italia, ingegneria sismica, 1188, 5-36. mccalpin j.p., 1987. geologic criteria for recognition of individual paleoseismic event in extensional environments: u.s. geological survey open-file report 87-673, 102-114. montone p., amato a., pondrelli s., 1999. active stress map of italy, journal of geophisical research, 110044, 25,595-25,610. nostro c., cocco m., belardinelli m., 1997. static stress changes in extensional regimes: an application to southern apennines (italy), bull. seismol. soc. am., 8877, 234-248. poli g.s., 1806. memoria sul tremuoto de’ 26 luglio del corrente anno, napoli. postpischl d. ed., 1985. catalogo dei terremoti italiani dall’anno 1000 al 1980. consiglio nazionale delle ricerche, progetto finalizzato geodinamica (cnr-pfg), quaderni de “la ricerca scientifica”, 111144, pp. 239. schwartz d.p. and coppersmith k., 1984. fault behavior and characteristic earthquakes: examples from the wasatch and san andreas faults, journal of geophysical reseaech, 8899, 5681-5698. schwartz d.p. and crone a., 1985. the 1983 borah peak earthquake: a calibration event for quantifying earthquake recurrence and fault behavior on great basin normal fault: u.s. geological survey open-file report 85-290, 153-160. stiros, s.c., 1996. identification of earthquakes from archaeological data. in: stiros, s., jones, r.e. (eds.), archaeoseismology, british school at athens, fitch laboratory occasional paper 7, 119152. stucchi m. e albini p., 2000. quanti terremoti abbiamo perso nell’ultimo millennio? in galadini, meletti & rebez (editors), le ricerche del gndt nel campo della pericolosità sismica (1996-1999), cnrgndt, 333-343. 167analisi archeosismologiche nel santuario ... ms. ricevuto il 6 marzo 2002 testo definitivo ricevuto il 4 giugno 2002 ms. received: march 6, 2002 final text received: june 4, 2002 ojs 632 matteivacchi 36,1 63-74.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 36 (1), 2023, 63-74 1. introduction located in the middle of the mediterranean basin, the italian peninsula and the two major italian islands (sardinia and sicily) constitute articulation points between the northern and the southern sides of the mediterranean sea. this geographical setting has resulted in an impressive array of coastal landforms (soldati & marchetti, 2017), shaped by both climatic and tectonic processes. italian coasts have also preserved a wide range of geomorphological and sedimentological proxies of late quaternary sea-level fluctuations which have been widely investigated since the late 19th century. in fact, geological sections rich in marine fauna were described along the italian coasts by doderlein in 1872, by gignoux in 1910 and by issel in 1914 who introduced the accademia dei lincei to the term “tyrrhenian stage” to indicate the period corresponding to the last interglacial (mis 5e ~125 ka bp, cita et al., 2006; rovere et al., 2016) and characterized by warmer climate and higher sea-level. at a shorter time scale (last few millennia), sealevel reconstructions carried out along the italian coasts have often coupled the geosciences with archaeology (i.e. antonioli et al., 2007; anzidei et al., 2013; mattei et al 2020a; caporizzo et al., 2021; aucelli et al., 2021). these investigations mainly resulted from the presence of submerged or semi-submerged coastal archaeological structures, which has attracted the attention of generations of sea-level scientists. for instance, pioneer geologists, such as lyell, recognized the importance of the pillars of the ancient roman market of pozzuoli (naples) in linking sea-level change and earth deformation with volcanic activity more than 120 years ago. in more recent times and since the seminal work of schmiedt (1972), the italian coasts have been a major scientific hub for investigations based on the use of archaeological evidence of maritime structures, such as ancient harbours or fish tanks, as proxies to measure the sea-level evolution, notably since the roman times (caputo & pieri, 1976; leoni & dai pra, 1997; lambeck et al., 2004b; aucelli et al., 2021). those geoarchaeological data, coupled with more traditional sea-level investigations based on the analysis of cores taken from coastal plains and/or on the analysis of fossil remains of littoral bioconstructions or beachrocks, show that the italian sea-level record is the richest in the mediterranean basin, notably for the postglacial period (e.g., last 21 ka bp; vacchi et al., 2016). in recent decades, several compilations of holo https://doi.org/10.26382/amq.2023.01 geographic variability of the millennial sea-level changes along the coasts of italy gaia mattei1, matteo vacchi2 1 dipartimento di scienze e tecnologie, università degli studi di napoli parthenope, napoli, italy. 2 dipartimento di scienze della terra, università di pisa, pisa, italy. corresponding author: g. mattei <gaia.mattei@uniparthenope.it> abstract: the large abundance of geological and archeological evidences of past sea-level stands have made the italian coasts a major focus for the mediterranean sea-level science since the beginning of 20th century. we have populated an openaccess database including the postglacial relative sea-level (rsl) data available for the coasts of italy. the creation of this database, produced following the most recent protocols of sea-level research, also allowed to evaluate the drivers that majorly controlled the variability of the holocene (last 12 ka bp) sea-level histories along the italian peninsula. major subsidence trends (driven by tectonics and sediment compaction) characterize the coastal plains of the north-eastern adriatic and northern tuscany. major uplift trends (often co-seismic) were found in ne sicily and in the southernmost tip of calabria. the most complex rsl evolution was observed in the phlegrean fields volcanic district where, in the same area, we observed the juxtaposition of the highest relict of a mid-holocene shoreline (more than 34 m above the present sea-level) and evidence of roman buildings more than 8 m below present sea level. the comparison of the italian sea-level with the geophysical models routinely used for the prediction of the rsl position through time yielded contrasting results. in particular, our analysis showed that caution should be used in paleogeographic reconstruction for periods older than 8.0 ka bp and only based on geophysical predictions. in fact, none of the models is able to reconcile the proxy-based rsl evolution in the early holocene period. this proposed database is an open repository and future production of new rsl data can be easily stored following the same scheme presented in this work. keywords: relative sea-level, italian coast; holocene, mediterranean sea. 64 mattei g. & vacchi m. cene (last ~12.0 ka bp) sea-level data have been produced for italy (lambeck et al., 2004a; lambeck et al., 2011; antonioli et al., 2009; vacchi et al., 2016; mattei et al., 2022). these data have been significantly enriched in the last 5 years thanks to a significant number of cores performed in marginal marine areas (e.g., valenzano, 2018; valenzano et al., 2018; mastronuzzi et al., 2018; d’orefice et al., 2020) as well as by the mapping and sampling of submerged beachrocks and maritime structures (e.g., vacchi et al., 2020b; aucelli et al., 2021; scardino et al., 2022). these data can be used to produce new suites of sea-level data, improving the spatial and temporal resolutions of the italian sealevel record. in this paper, we have compiled, critically analysed and updated a database of the holocene rsl data available for the italian coast (fig. 1) following the international protocol developed in the recent inqua project holsea (khan et al., 2019). we populated the database with sea-level data from cores taken from transitional and marine deposits, as well as with sea-level data from beachrocks, fossil remains of intertidal bioconstructions and archaeological indicators. the database includes 570 sea level points that have been populated into a dedicated webgis where the whole dataset is available in an open-source repository (https:// dist.altervista.org/seaproxy/). we compared the reconstructed sea-level records with a number of geophysical glacioand hydro-isostatic (gia) models, which are routinely used for the mediterranean area, in order to assess the predictive performance of the sea-level evolution during the holocene period. 2. methods 2.1. classification of the sea-level data based on the latest protocols for sea-level research (hijma et al., 2015; khan et al., 2019) we have reinterpreted previous coastal studies producing the following types of sea-level data: 1) sea-level index points (slips) which constrain the past relative sea-level in space and time. to produce a slip the following information must be available: (1) the location of the indicator; (2) the age of the indicator; and (3) the elevation of the indicator, corrected for the indicative meaning; (i.e. a known relationship between the indicator and a contemporary tidal level, the mean sea level (msl) in our database, shennan et al., 2015). the indicative meaning is composed of the indicative range (ir), i.e., the elevation range over which the marker forms and the reference water level (rwl), the mid-point of the abovementioned range (shennan et al., 2015). the frame to assess the indicative meaning for the mediterranean sea-level data was developed by vacchi et al., (2016) and, since then, has been widely applied in mediterranean sea-level studies (e.g. brisset et al., 2018; karkani et al., 2017; rached et al., 2022). for each dated sample, slipn were produced according to the following equation (shennan & horton, 2002): slipn = an rwln where an is the proxy altitude and rwln is the reference water level of the proxy n. most of the slips were already included in the recent databases produced for the western and central mediterranean area (e.g., vacchi et al., 2016; 2018, mattei et al., 2022). they are derived from cores in coastal and alluvial plains, coastal marshes and lagoons. (e.g., primavera et al., 2011; fontana et al., 2017, melis et al., 2017). the indicative meaning of these samples is generally based on biostratigraphy and, in particular, on the macroand micro-faunal assemblages (i.e., malacofauna, foraminifera and ostracod assemblages, e.g., rossi et al., 2011; marriner et al., 2014; giaime et al., 2017). the detailed description of the indicative meaning associated with the different depositional facies is provided in vacchi et al. (2016). other slips included in the database are beachrocks, fixed biological (mainly vermetids and lithophyllum byssoides rims) and archaeological slips. the latter sea-level data were widely used in the mediterranean area (e.g., lambeck et al., 2011; morhange & marriner, 2015) but caution should be used in the definition of the related indicative meaning (vacchi et al., 2016; benjamin et al., 2017). we only transformed into slips those structures which are related to the former mean sea level (e.g., fish tanks and harbour structures) or when found covered by fossil biological encrustations which clearly define the relationship with the former tidal frame (vacchi et al., 2020a). 2) sea-level terrestrial and marine limiting points (tlp and mlp, respectively) which constrain the past relative sea level above or below a given altitude. all the samples that did not show a clear and robustly established relationship with the former msl were converted into limiting points (mattei et al., 2022). however, these data are extremely important in constraining the rsl position below (tlp) or above (mlp) a reconstructed elevation (mann et al., 2019). for the italian coasts, tlp are typically samples deposited in freshwater swamps, backshore deposits, fluvial environments and upper beach deposits. mlp are generally represented from samples deposited in the infralittoral zone, from fossil corals or other infralittoral bioconstructions found in living position or from interlaced roots and rhizomes of the marine seagrass posidonia oceanica. furthermore, we considered terrestrial limiting points those archaeological indicators that were theoretically above the msl at the time of their functioning period, such as tombs and burials, floors of maritime villas, coastal quarries (mattei et al., 2022). the ages of the geological samples were estimated using radiocarbon (14c) dating of organic material from salt and freshwater marshes as well as marine and lagoonal shells. all radiocarbon ages included in the present database were re-calibrated to provide dates in sidereal years with a 2s range using calib 8.2 (stuiver & reimer, 1993). we used a laboratory multiplier of 1 with 95% confidence limits and employed the intcal20 (reimer et al., 2020) and marine20 (heaton et al., 2020) datasets for terrestrial samples and marine samples, respectively. in calibrating the samples of organic sediment, we assumed that the original depositional environ 65 geographic variability of the millennial sea-level changes along the coasts of italy fig. 1 spatial distribution of the rsl markers collected in the seaproxy geodatabase. sector 1 is the liguria-tuscany sector, sector 2 is the north-central tyrrhenian sea, sector 3 is sardinia island, sector 4 is sicily island and southern calabria, sector 5 is mid to southern adriatic sea and the gulf of taranto, sector 6 is the northern adriatic sea. ment was a transitional zone in the back-coastal area, influenced by fluvial processes as well as marine inputs. therefore, for sediment dates where the percentage of marine carbon was available (e.g., melis et al., 2017, 2018) a mixed intcal13/marine13 calibration method was applied (di rita et al., 2011). for archaeological samples, the age was provided by archaeological structures and/or by ceramics found in sedimentary layers (aucelli et al., 2018, 2019; mattei et al., 2018; vacchi et al., 2020a). 2.2. geophysical predictions of relative sea level we compared the newly assembled suite of slips and limiting points with two different geophysical glaciohydro isostatic adjustment (gia) models that predict the rsl evolution in this portion of the mediterranean sea. proxy-based sea-level data are fundamental to both constrain these models and to test the accuracy of their predictions. we compared all the data clusters included in the database with two mediterranean predictions available in the literature. we adopted the recent rsl prediction based on the ice-6g chronology developed by prof. w.r peltier and collaborators at the university of toronto (peltier et al., 2015), and the mantle rheological profile vm5a available in vacchi et al., (2018). the second rsl prediction we adopted is developed by prof. k. lambeck and collaborators at the australian national university (anu, lambeck et al., 2011) using the k33_j1b_ws9_6 geophysical model (hereafter anu -k33). 2.3. webgis application the web-application seaproxy (http:// dist.altervista.org/seaproxy) was developed for both data management and visualization. for this purpose, two applications have been designed. the first application is dedicated to database management and is based on the open-source language php, supported by mysql (fig. 2a). the second application for displaying spatial data is based on the open-source lealeft library, allowing the creation of functional and robust interactive maps based on json (javascript object notation) archives via javascript (fig. 2b). this choice was driven by the fact that leaflet is the leading open-source javascript library applied to the creation of mobile-friendly interactive maps and json (javascript object notation) is a database in text format used in the exchange of data between client/server applications, ideal for exchanging data between different applications. the database implemented in this research is based on mysql, an open-source rdbms ("relational database management system"), representing a reliable solution for web applications managing a large amount of data, in relation to each other. this vertical web application has been developed with a twofold purpose: favouring the remote interaction of a multidisciplinary research group and providing a free access resource to the scientific community involved in sea-level studies. seaproxy was designed to collect italian sealevel data and it is consequently structured into four main sections: a. id and bibliographic source b. geographic position c. dating information defining the horizontal position of rsl and uncertainty d. measurement methods including sampling technique, stratigraphic information, gps configurations, tidal range, elevation, and related indicative meaning information, rsls deduced with related uncertainty. 3. results the final database includes 391 slips and 179 limiting points. the temporal range covers the last ~14 ka bp with a general increase in the number of datapoints through time. slips number increase significantly in the last 8000 years representing the ~78% of the entire database (fig. 3c). slips number is particularly abundant (73) between 2.0 and 1.0 ka bp, when we found the maximal number of the archaeological proxies (fig. 3c). the entire database is freely available at the following address: https://dist.altervista.org/seaproxy/ in fig. 3a and 3b, we plotted the entire slips record vs the whole suite of ice-6g and anu-k33 geo 66 mattei g. & vacchi m. fig. 2 workflows of a) data elaboration and interpretation and b) webgis application. serve a large scatter in the dataset for the last 2.0 ka when the rsl record is mostly composed of samples collected in the volcanic district of naples. in sector 3 (fig. 1) we included data collected along the coasts of sardinia (fig. 4c). here, the rsl record is composed of 40 slips, 22 mlps and 10 tlps. the oldest slip indicates that rsl rose by 45.5 ± 1.5 m in the last ~10.8 ka bp. early to mid-holocene data show variability, probably related to compaction processes affecting the data collected in the cagliari coastal plain (see section 4). the scatter in the data is physical predictions for the italian regions included in the database. the maximal difference between data and models is visible in the early holocene (12 -8 ka bp) period where ice-6g seem to overestimate the rsl position while a general underestimation by anu-k33 is shown by the data. in order to analyse more in -depth, the general trends of the sea-level evolution along the italian coast we have grouped the data in 6 macro-regions according to geographical proximity. this allowed us to have a broader picture of the sea-level evolution in the different sectors of the italian coasts. however, we note that this is an openaccess database that can be exploited for more detailed analysis of the rsl changes at a more local scale. in sector 1 (fig. 4a) we included the data collected from the seaboard of the northwestern tyrrhenian and ligurian seas (from liguria to the border between tuscany and latium, see fig. 1). here, the rsl record is composed of 48 slips, 7 mlps and 10 tlps. the oldest slip indicates that rsl rose by 45.1 ± 1.1m in the last ~12.6 ka. younger data indicate major rising rates until ~7.1 ka followed by a significant stabilization of the rsl in the mid to late holocene. in this period, the maximal rsl variation was within 5 m even if we observe a scatter in the data which was likely related to subsidence processes driven by both compaction and tectonics (see section 4). sea-level data are also abundant along the mid to southern tyrrhenian coast of italy (e.g., from latium to campania, sector 2 fig. 1 and 4b). here, the rsl record is composed of 122 slips, 21 mlps, and 52 tlps. the oldest slip indicates that rsl was at -43.9 ± 0.7 m at ~12.9 ka. younger data show significant variability which is mainly driven by the data from the volcanic district of naples where data are affected by major ground movements. however, the general trend in this area indicates a stabilization of the rsl at ~7.2 ka bp when a cluster of slips indicates rsl was between 3 and 5 m. data between 7.0 and 2.0 ka generally show good agreement among slips and limiting points. conversely, we ob 67 geographic variability of the millennial sea-level changes along the coasts of italy fig. 3 a) total plot of the validated slips compared to the suite of ice-6g gia predictions available for the italian coast; b) total plot of the validated slips compared to suite of anu-k33 gia predictions available for the italian coast; c) stacked histogram of the validated slips produced along the italian coasts. 68 mattei g. & vacchi m. reduced in the last 4.0 ka. since that period, the total rsl variation has not exceeded 2 m. in sicily and southern calabria (sector 4, fig. 1), the rsl record is composed of 33 slips, 7 mlps and 7 tlps (fig. 4). here, the oldest slip indicates rsl was at -36.9 ± 1.1 m at ~9.8 ka bp. data were mainly collected in the easternmost and westernmost portions of the island. we then observe an early holocene rising trend bringing the rsl at -6.2 ± 1.0 m at ~6.7 ka bp. a cluster of younger slips indicates that the rsl variation in the last 4.0 ka was likely within 2.5 m. however, data from the area of capo milazzo (ne sicily) show a significant departure from this pattern indicating that tectonic uplift brought the rsl above the present datum since 4.5 ka bp. in sector 5 (fig. 1) we included data collected along the mid-southern adriatic (from mid-abruzzo to southern apulia) and in the gulf of taranto. the data suite comprises 39 slips, 2 mlps and 7 tlps (fig. 4). the oldest slip indicates that rsl was at -44.9 ± 1.1 m at ~9.8 ka bp. younger clusters of slips indicate rsl ~ -17.5 m at ~8.8 ka bp and at ~-6.0 m at ~6.9 ka bp. mid to late holocene slips show scatter likely related to differential compaction-driven subsidence. in the last ~3.5 ka bp, data seem to indicate that the maximum rsl variation has not exceeded 2 m. in sector 6, we grouped the data collected in the northern portion of the adriatic sea (fig. 1). here the record is composed of 102 slips, 6 mlps and 13 tlps (fig. 4). the entire record is affected by a significant fig. 4 rsl evolution in the 6 sectors of the italian coastline. slips (red) are plotted as change in sea level relative to present against calibrated age. limiting points are plotted as terrestrial (green) or marine (blue) horizontal lines. vertical and horizontal errors for each rsl datapoint based on 2s elevation and age uncertainties. the rsl records compared to the suite of gia predictions available for each coastal sector (see fig. 1): grey line is the ice-6g (vm5a) model and dark yellow line is anu-k33 model. scatter related to the subsidence trends that are locally controlled by sediment compaction and/or tectonics. the oldest slip places the rsl at -53 m ± 0.9 m at ~13 ka bp. early holocene data are very scattered showing up to 15 m of elevational differences between coeval slips between ~11 and ~9 ka bp. the scatter in the data is present, in minor terms, also in the mid to late holocene. in this time span, the virtually less compacted slips indicate rsl was at -5.5 ± 0.7 m at ~7.3 ka bp and at -1.8 ± 0.7 m at ~5.3 ka bp. in the last 2.0 ka, the total rsl variation was within 1 m. 4. drivers of rsl evolution along the italian coasts the database presented in this work updates previous compilations (e.g., lambeck et al., 2004a, b; 2011; vacchi et al., 2016) by expanding the sea-level record along the italian coast using a standardized protocol to produce sea-level data (e.g., khan et al., 2019). the whole database, available in a gis-based opensource repository, fits the most recent standard of sealevel studies (e.g., khan et al., 2019) representing a solid base for multiple analyses relating to the coastal landscape evolution of the italian coast during the late quaternary. however, our compilation lacks long and robust sea-level records in some italian coastal regions such as the western ligurian sea, the central portion of the adriatic, much of the calabria coast as well as the southern coast of sicily. future investigations should prioritize data acquisition in these areas, notably for the production of slips. the global picture of the sea-level evolution (fig. 3a,b) shows that, at the italian scale, the maximum holocene rsl variation did not exceed 50 m. data further indicate that a general slowdown of the sea-level rising rates is observed after 7 ka bp, consistent with the end of the major ice-sheets melting in the northern hemisphere (peltier, 2004; lambeck et al., 2014; vacchi et al., 2021). since that period, we observe variability in the sea-level history which is mainly driven by the diverse vertical motions affecting the different portions of the italian coast. the quantification of these vertical motions was often assessed by comparing the local sea-level evolution with modelled gia predictions (e.g., lambeck et al., 2011; anzidei et al., 2014). however, issues in the ability to correctly predict the gia signal in the mediterranean were raised in recent years thanks to an increase in available sea-level records for the basin (melis et al., 2018; vacchi et al., 2018; 2020b). a detailed analysis of residuals between data and models (see mattei et al., 2022) is beyond the scope of this paper. however, the results of the present compilation indicate that none of the presently available gia models is able to predict the italian sea-level evolutions for the whole holocene period. this is particularly evident in the early holocene period (12-8 ka bp) when, in all the italian macroregions, we observe a significant underestimation of the sea-level position by the anu-k33 model. by contrast, ice-6g overpredicts the sea-level during the same time span. this might depend on the ice-sheet models (shapes and sizes) as well as on the solid earth parameters and stratification (vacchi et al, 2020b). for this reason, the use of geophysical models for paleogeographic reconstructions between the last glacial maximum and the end of the early holocene (e.g., ~21 to ~8 ka bp) can be significantly biased by the low predictive performance of these models. in the mid-to late holocene period (8 to 0 ka bp), many macro-regions still show a scatter in the data which is mainly related to differential subsidence rates driven by sediment compaction and local tectonics. in the ligurian and northern tyrrhenian sea (sector 1), the quality of the dataset was much improved thanks to the significant amount of new data deriving from cores taken between pisa and livorno (kaniewsky et al., 2018) and at the border between tuscany and latium (d’orefice et al., 2020). this new dataset indicates rsl was significantly higher than the one derived from the versilia, arno and magra coastal plains which are affected by subsidence related to sediment compaction and/or tectonics (e.g., chelli et al., 2017). in this region ice-6g is able to intercept the highest slips (virtually uncompressed) while anu-k33 is significantly below, notably between 8 and 3 ka bp. a similar pattern is observed in sardinia (sector 3) where the midto late holocene record was significantly improved in recent years (melis 69 geographic variability of the millennial sea-level changes along the coasts of italy fig. 5 maximal and minimal gia contribution of rsl change expected in the next 2000 yr across the mediterranean sea according to the two models anu s4 and ice-6g c (vm5a). modified from spada and melini (2022). 70 mattei g. & vacchi m. et al., 2017; 2018; pascucci et al., 2018; vacchi et al., 2020b). the updated sea-level record show very good agreement with the ice-6g in the last 7.5 ka while anuk33 shows an underestimation of the sea-level position during the same period. the complex tectonic setting affecting portions of the mid to southern tyrrhenian sea (region 2) and sicily (region 5) means that it is challenging to analyse the predictive performance of the different models. region 2 shows the maximum scatter in the dataset (fig. 4). this is related to the volcano-tectonic influence that widely affected the rsl evolution near the volcanic districts of the phlegrean fields and vesuvius (see mattei et al., 2022). in this area, the multiple bradyseismic crises (rapid land movements of volcano-tectonic origin due to the evolution of the magmatic body and its hydrothermal system, di vito et al., 1999; aucelli et al., 2017) occurring during the holocene strongly interfered with the relative sea-level variation and related coastal changes, even if not always associated with main eruptions (morhange et al., 2006; isaia et al., 2019). in particular, the most-significant sea-level evolution can be associated with the third eruptive epoch of the phlegrean fields, during which a major uplift (5.5-3.5 ka bp, di vito et al., 1999) resulted in a relative sea-level fall of more than 34 m (e.g., starza terrace) which represents the most uplifted shoreline of the entire mediterranean basin. in the surrounding tectonically stable areas of sector 2 (e.g., tiber and sele coastal plains), the early to mid-holocene are in very good agreement with ice-6g while in the late holocene, data show too much scatter to accurately evaluate the predictive performance of the models. in sector 4, data from southern calabria and from the ne sector of sicily show a significant departure from the rest of the dataset due to the higher seismicity of the area (e.g., antonioli et al., 2006a; scicchitano et al., 2011; spampinato et al., 2012; anzidei et al., 2013). in these coastal sectors, the holocene uplift trend (often characterized by co-seismic displacements, e.g. scicchitano et al. 2011) played a major role in controlling the present elevation of the sea-level data which are presently placed several meters above those from the westernmost part of sicily which is considered tectonically stable (antonioli et al., 2006b). in sardinia (sector 3), there was a significant increase, in the last 5 years, of sea-level data derived from lagoonal cores and submerged beachrocks (e.g., melis et al., 2017; 2018; pascucci et al., 2018; vacchi et al., 2020b). the island is tectonically very stable representing a key site to tune the gia models along the mediterranean basin (vacchi et al., 2018). in the mediterranean, the predicted gia-driven land-level changes are controlled by the interplay between ice and water loading (lambeck & purcell, 2005; stocchi & spada, 2009). the latter resulted in widespread subsidence that reach the maximum in much of the basin (lambeck & purcell, 2005; stocchi & spada, 2009; roy & peltier, 2018) and that is also compensated by uplift along the continental margins (stocchi et al., 2018). the sardinia record constitutes a crucial benchmark to better evaluate hydro-isostatic subsidence in the mediterranean basin because the island lies in the centre of the western mediterranean basin, where all gia models predict a maximum hydro-isostatic contribution (see spada & melini, 2022, fig. 5). in the early holocene, both ice6g and anu-k33 cannot reconcile the rsl evolution as already noticed in the other regions of the italian coast. on the contrary, we observe a very good fit between ice-6g and the mid to late-holocene rsl evolution in sardinia. by contrast, the anu-k33 prediction remains significantly below the large majority of slips in this region further confirming an overestimation of the hydro-isostatic signal in this part of the mediterranean basin. the mid to late holocene rsl dataset for the coast of the southern adriatic sea and the gulf of taranto (sector 5) has been significantly expanded in the last 5 years (e.g., valenzano, 2018; valenzano et al., 2018; mastronuzzi et al., 2018). in particular, the new data from the gulf of taranto (e.g., valenzano, 2018, valenzano et al., 2018) further confirm the poor prediction performance of both gia models in the early holocene while there is a progressive reconciliation in the midto late-holocene period with ice-6g showing a better fit with the higher slips (e.g., less compaction). the northern adriatic (region 6) has the richest sea -level dataset of the whole italian coast. this is mainly composed of data derived from cores performed in the large coastal lagoons outcropping in the area (e.g., amorosi et al., 2005; mcclennen & housley, 2006; fontana et al. 2017) as well as along the wide continental platform (e.g., correggiari et al., 2001; ronchi et al., 2018a,b). the whole dataset shows a large scatter throughout the holocene. the present position of the sea-level data in this portion of italy is chiefly controlled by differential subsidence trends which are driven by both sediment compaction and/or tectonics. the latter plays a very important role along the north-eastern border of the po plain which is the foreland basin of two fold-and-thrust belts: the north-northeastern vergent northern apennines and the southern vergent southern alps (carminati et al., 2003). this geologic framework implies an increasing long-term component of subsidence between the po plain, the venice lagoon and the friuli coastal plain which is almost entirely controlled by the retreat and flexure of the adriatic plate subducting underneath the apennines (cuffaro et al., 2009). due to the major subsidence rates of this area, it is, at present, challenging to evaluate the predictive performance of the gia models in the northern adriatic. 5. conclusions we have assembled a comprehensive database of holocene sea-level data (e.g., index points, marine and terrestrial limiting points) which are now available in an open-source repository in a gis environment. all the sea-level data included in the repository were produced following the international protocols for sea-level studies. furthermore, radiocarbon dates were re-calibrated according to the latest calibration curve. the present overview of the italian sea-level evolution indicates that the entire rsl in the last ~13 ka bp was within 50 m. we observe a rapid rise in the rsl between 13.0 to 7.0 ka followed by a sudden rsl stabi nary international, 145, 3-18. antonioli f., anzidei m., lambeck k., auriemma r., gaddi d., furlani s., orrù p., solinas e., gaspari a., karinja s., kovačić v., surace, l. (2007) sea -level change during the holocene in sardinia and in the northeastern adriatic (central mediterranean sea) from archaeological and geomorphological data. quaternary science reviews, 26(19-21), 2463-2486. antonioli f., ferranti l., fontana a., amorosi a., bondesan a., braitenberg c., dutton a., fontolan g., furlani s., lambeck k., mastronuzzi g., monaco c., spada g., stocchi p. (2009) holocene relative sea-level changes and vertical movements along the italian and istrian coastlines. quaternary international, 206(1-2), 102-133. anzidei m., antonioli f., benini a., gervasi a., guerra i. (2013) evidence of vertical tectonic uplift at briatico (calabria, italy) inferred from roman age maritime archaeological indicators. quaternary international, 288, 158-167. anzidei m., lambeck k., antonioli f., furlani s., mastronuzzi g., serpelloni e., vannucci g. (2014) coastal structure, sea-level changes and vertical motion of the land in the mediterranean. geological society, london, special publications, 388(1), 453-479. aucelli p.p., brancaccio l., cinque a. (2017) vesuvius and campi flegrei: volcanic history, landforms and impact on settlements. in: landscapes and landforms of italy (ed. by soldati m, marchetti m.). springer, cham, 389-398. aucelli p., cinque a., mattei g., pappone g., stefanile m. (2018) coastal landscape evolution of naples (southern italy) since the roman period from archaeological and geomorphological data at palazzo degli spiriti site. quaternary international, 483, 23-38. aucelli p., cinque a., mattei g., pappone g., rizzo a. (2019) studying relative sea level change and correlative adaptation of coastal structures on submerged roman time ruins nearby naples (southern italy). quaternary international, 501, 328 -348. doi: 10.1016/j.quaint.2017.10.011. aucelli p.p., mattei g., caporizzo c., cinque a., amato l., stefanile m., pappone g. (2021) multi-proxy analysis of relative sea-level and paleoshoreline changes during the last 2300 years in the campi flegrei caldera, southern italy. quaternary international, 602, 110-130. benjamin j., rovere a., fontana a., furlani s., vacchi m., inglis r.h., galili e., antonioli f., sivan d., miko s., mourtzas n., felja i., meredith-williams m., goodman-tchernov b., kolaiti e., anzidei m., gehrels r. (2017) late quaternary sea-level changes and early human societies in the central and eastern mediterranean basin: an interdisciplinary review. quaternary international, 449, 29-57. brisset e., burjachs f., navarro b.j.b., de pablo j.f.l. (2018) socio-ecological adaptation to earlyholocene sea-level rise in the western mediterranean. global and planetary change, 169, 156-167. lization in the last 7 millennia driven by the end of the major deglaciation period of the northern hemisphere ice-sheets. since that period, land-level changes controlled by gia, tectonics and sediment compaction have become the main drivers of the rsl change evolution along the italian coast. in particular, we observed major subsidence trends (driven by tectonics and sediment compaction) in the coastal plains of the north-eastern adriatic and in northern tuscany. major uplift trends (often co-seismic) were found in ne sicily and in the southernmost tip of calabria. a peculiar case constitutes the phlegrean fields volcanic district where, in the same area, we observed the juxtaposition of the highest relict of a holocene shoreline (more than 34 m above the present sea-level) and evidence of roman buildings more than 8 m below present sea level. this area represents one of the most active volcanic districts of the entire mediterranean where the shortlived alternation of subsidence and uplift has induced abrupt coastal landscape transformations in the last millennia. the comparison of the assembled dataset with the gia models routinely used for the prediction of the rsl position through time yielded contrasting results. in particular, none of the models is able to reconcile the rsl evolution in the early holocene period. for this reason, any paleogeographic reconstruction for periods older than 8.0 ka bp and only based on geophysical predictions should be used with caution. the gis database is a free tool available for future users for more specific assessments at smaller scales. furthermore, it is an open repository and future production of new rsl data can be easily stored following the same scheme presented in this work. acknowledgements thanks are due to all the scientists that, in the last 60 years, collected all the data inserted in this database. this paper benefited from the discussion at the neptune meetings (inqua cmp project 2003p). we thank nick marriner (cnrs-théma, france) for the friendly revision of the english text. thanks are also due to ilaria mazzini, editor of amq, who encouraged this paper. the data of the seaproxy database are available for future usage under cc-by-nc licence. for any correction, inquiry or to have the excel spreadsheet of the data please email gaia.mattei@uniparthenope.it. references amorosi a., centineo m.c., colalongo m.l., fiorini f. (2005) millennial-scale depositional cycles from the holocene of the po plain, italy. marine geology, 222, 7-18. antonioli f., ferranti l., lambeck k., kershaw s., verrubbi v., dai pra g. (2006a) late pleistocene to holocene record of changing uplift rates in southern calabria and northeastern sicily (southern italy, central mediterranean sea). tectonophysics, 422(1-4), 23-40. antonioli f., kershaw s., renda p., rust d., belluomini g., cerasoli m., radtke u., silenzi s. (2006b) elevation of the last interglacial highstand in sicily (italy): a benchmark of coastal tectonics. quater 71 geographic variability of the millennial sea-level changes along the coasts of italy 72 mattei g. & vacchi m. caporizzo c., gracia f.j., aucelli p.p.c., barbero l., martín-puertas c., lagóstena l., ruiz j.a., alonso c., mattei g., galán-ruffoni i., lópezramírez j.a., higueras-milena a. (2021) lateholocene evolution of the northern bay of cádiz from geomorphological, stratigraphic and archaeological data. quaternary international, 602, 92109. caputo m., pieri l. (1976) eustatic sea variation in the last 2000 years in the mediterranean. journal of geophysical research, 81(33), 5787-5790. carminati e., doglioni c., scrocca d. (2003) apennines subduction‐related subsidence of venice (italy). geophysical research letters, 30(13), 1717. chelli a., pappalardo m., bini m., brückner h., neri g., neri m., spada g. (2017) assessing tectonic subsidence from estimates of holocene relative sea-level change: an example from the nw mediterranean (magra plain, italy). the holocene, 27 (12), 1988-1999. cita m.b., capraro l., ciaranfi n., di stefano e., marino m., rio d., sprovieri r., vai g.b. (2006) calabrian and ionian: a proposal for the definition of mediterranean stages for the lower and middle pleistocene. episodes journal of international geoscience, 29(2), 107-114. correggiari a., trincardi f., langone l., roveri m. (2001) styles of failure in late holocene highstand prodelta wedges on the adriatic shelf. journal of sedimentary research, 71(2), 218-236. cuffaro m., doglioni c., riguzzi f. (2009) present geodynamics of the northern adriatic plate. rendiconti online soc. geol. it. d’orefice m., bellotti p., bertini a., calderoni g., censi neri p., di bella l., fiorenza d., foresi l.m., louvari m.a., rainone l., vittori c., goiran j.-p., schmitt l., carbonel p., preusser f., oberlin c., sangiorgi f., davoli, l. (2020) holocene evolution of the burano paleo-lagoon (southern tuscany, italy). water, 12(4), 1007. di rita f., simone o., caldara m., gehrels w.r., magri, d. (2011) holocene environmental changes in the coastal tavoliere plain (apulia, southern italy): a multiproxy approach. palaeogeography, palaeoclimatology, palaeoecology, 310(3-4), 139-151. di vito m.a., isaia r., orsi g., southon j.d., de vita s., d'antonio m., ... piochi, m. (1999) volcanism and deformation since 12,000 years at the campi flegrei caldera (italy). journal of volcanology and geothermal research, 91(2-4), 221-246. doderlein p. (1872) alcune generalità intorno la fauna sicula dei vertebrati. annuario società naturalisti. tipografia soliani, modena. fontana a., vinci g., tasca g., mozzi p., vacchi m., bivi g., salvador s., rossato s., antonioli f., asioli a., bresolin m., di mario f., hajdas, i. (2017) lagoonal settlements and relative sea level during bronze age in northern adriatic: geoarchaeological evidence and paleogeographic constraints. quaternary international, 439, 17-36. giaime m., morhange c., ontiveros m.á.c., fornós j.j., vacchi m., marriner n. (2017) in search of pollentia's southern harbour: geoarchaeological evidence from the bay of alcúdia (mallorca, spain). palaeogeography, palaeoclimatology, palaeoecology, 466, 184-201. gignoux m. (1913) les formations marines pliocenes et quaternaires de l'italie du sud et de la sicilie. ann. univ. lyon, 35, 1-693. heaton t.j., köhler p., butzin m., bard e., reimer r.w., austin w.e., bronk ramsey c., grootes p.m., hughen k.a., kromer b., reimer p.j., adkins j., burke a., cook m.s., olsen j., skinner l.c. (2020) marine20-the marine radiocarbon age calibration curve (0-55,000 cal bp). radiocarbon, 62(4), 779-820. hijma m.p., engelhart s.e., törnqvist t.e., horton b.p., hu p., hill d.f. (2015) a protocol for a geological sea-level database. in: handbook of sea-level research (ed. by: shennan i., long a.j., horton b.p.). wiley blackwell, 536-553. isaia r., vitale s., marturano a., aiello g., barra d., ciarcia s., iannuzzi e., tramparulo f.d.a. (2019) high-resolution geological investigations to reconstruct the long-term ground movements in the last 15 kyr at campi flegrei caldera (southern italy). journal of volcanology and geothermal research, 385, 143-158. issel a. (1914) lembi fossiliferi quaternari o recenti osservati nella sardegna meridionale dai prof. d. lovisato, atti acc. lincei rend. fis., 23(5), 759770. kaniewski d., marriner n., morhange c., vacchi m., sarti g., rossi v., bini m., pasquinucci m., allinne c., otto t., luce f., van campo e. (2018) holocene evolution of portus pisanus, the lost harbour of pisa. scientific reports, 8(1), 1-14. karkani a., evelpidou n., vacchi m., morhange c., tsukamoto s., frechen m., maroukian � . (2017) tracking shoreline evolution in central cyclades (greece) using beachrocks. marine geology, 388, 25-37. khan n.s., horton b.p., engelhart s., rovere a., vacchi m., ashe e.l., törnqvist t.e., dutton a., hijma m.p., shennan i. (2019) inception of a global atlas of sea levels since the last glacial maximum. quaternary science reviews, 220, 359-371. lambeck k., antonioli f., purcell a., silenzi s. (2004a) sea-level change along the italian coast for the past 10,000 yr. quaternary science reviews, 23 (14-15), 1567-1598. lambeck k., anzidei m., antonioli f., benini a., esposito a. (2004b) sea level in roman time in the central mediterranean and implications for recent change. earth and planetary science letters, 224(3-4), 563-575. lambeck k., purcell a. (2005) sea-level change in the mediterranean sea since the lgm: model predictions for tectonically stable areas. quaternary science reviews, 24(18-19), 1969-1988. lambeck k., antonioli f., anzidei m., ferranti l., leoni g., scicchitano g., silenzi, s. (2011) sea level change along the italian coast during the holocene and projections for the future. quaternary international, 232(1-2), 250-257. lambeck k., rouby h., purcell a., sun y., sambridge m. (2014) sea level and global ice volumes from the last glacial maximum to the holocene. proceedings of the national academy of sciences, 111(43), 15296-15303. leoni g., dai pra g. (1997) sea level variations along the latium coastal region by archaeological indicators; variazioni del livello del mare nel tardo olocene (ultimi 2500 anni) lungo la costa del lazio in base ad indicatori geo-archeologici. interazioni fra neotettonica, eustatismo e clima. technical report n. enea-rt-amb-97-08, enea, centro ricerche casaccia, dipt. ambiente, roma. issn 11205555. mann t., bender m., lorscheid t., stocchi p., vacchi m., switzer a.d., rovere a. (2019) holocene sea levels in southeast asia, maldives, india and sri lanka: the seamis database. quaternary science reviews, 219, 112-125 marriner n., morhange c., faivre s., flaux c., vacchi m., miko s., dumas v., boetto g., rossi i.r. (2014) post-roman sea-level changes on pag island (adriatic sea): dating croatia's “enigmatic” coastal notch? geomorphology, 221, 83-94. mastronuzzi g., milella m., piscitelli a., simone o., quarta g., scarano t., calcagnile l., spada i. (2018) landscape analysis in torre guaceto area (brindisi) aimed at the reconstruction of the late holocene sea level curve. geogafia. fisica dinamica quaternaria, 41, 65-79. mattei g., troisi s., aucelli p., pappone g., peluso f., stefanile m. (2018) sensing the submerged landscape of nisida roman harbour in the gulf of naples from integrated measurements on a usv. water, 10(11), 1686. mattei g., aucelli p.p., caporizzo c., rizzo a., pappone g. (2020a) new geomorphological and historical elements on morpho-evolutive trends and relative sea-level changes of naples coast in the last 6000 years. water, 12(9), 2651. mattei g., rizzo a., anfuso g., aucelli p.p.c., gracia f.j. (2020b) enhancing the protection of archaeological sites as an integrated coastal management strategy: the case of the posillipo hill (naples, italy). rendiconti lincei. scienze fisiche e naturali, 31(1), 139-152. mattei g., caporizzo c., corrado g., vacchi m., stocchi p., pappone g., schiattarella m., aucelli p.p.c. (2022) on the influence of vertical ground movements on late-quaternary sea-level records. a comprehensive assessment along the midtyrrhenian coast of italy (mediterranean sea). quaternary science reviews, 279, 107384. doi:10.1016/j.quascirev.2022.107384 mcclennen c.e., housley r.a. (2006) late-holocene channel meander migration and mudflat accumulation rates, lagoon of venice, italy. journal of coastal research, 22(4), 930-945. melis r.t., depalmas a., di rita f., montis f., vacchi m. (2017) mid to late holocene environmental changes along the coast of western sardinia (mediterranean sea). global and planetary change, 155, 29-41. melis r.t., di rita f., french c., marriner n., montis f., serreli g., sulas f., vacchi m. (2018) 8000 years of coastal changes on a western mediterranean island: a multiproxy approach from the posada plain of sardinia. marine geology, 403, 93-108. morhange c., marriner n. (2015) archeological and biological relative sea-level indicators. in: handbook of sea-level research (ed. by: shennan i., long a.j., horton b.p.). wiley blackwell, 146-156. morhange c., marriner n., laborel j., todesco m., oberlin c. (2006) rapid sea-level movements and noneruptive crustal deformations in the phlegrean fields caldera, italy. geology, 34(2), 93 -96. pascucci v., de falco g., del vais c., sanna i., melis r.t., andreucci s. (2018) climate changes and human impact on the mistras coastal barrier system (w sardinia, italy). marine geology, 395, 271284. peltier w.r. (2004) global glacial isostasy and the surface of the ice-age earth: the ice-5g (vm2) model and grace. annual review of earth and planetary sciences, 32, 111-149. peltier w.r., argus d.f., drummond r. (2015) space geodesy constrains ice age terminal deglaciation: the global ice‐6g_c (vm5a) model. journal of geophysical research: solid earth, 120(1), 450487. primavera m., simone o., fiorentino g., caldara m. (2011) the palaeoenvironmental study of the alimini piccolo lake enables a reconstruction of holocene sea-level changes in southeast italy. the holocene, 21(4), 553-563. rached l., rachida t., mohamed s., younès j., sahbi j., marco a. (2022) sedimentary record from holocene to present-day southeastern tunisia: facies, paleoenvironments and climate changes. arabian journal of geosciences, 15(10), 1-20. reimer p.j., austin w.e.n., bard e., bayliss a., blackwell p.g., bronk ramsey c., butzin m., cheng h., edwards r.l., friedrich m., grootes p.m., guilderson t.p., hajdas i., heaton t.j., hogg a.g., hughen k.a., kromer b., manning s.w., muscheler r., palmer j.g., pearson c., van der plicht j., reimer r.w., richards d.a., scott e.m., southon j.r., turney c.s.m., wacker l., adolphi f., büntgen u., capano m., fahrni s.m., fogtmann-schulz a., friedrich r., köhler p., kudsk s., miyake f., olsen j., reinig f., sakamoto m., sookdeo a., talamo s. (2020) the intcal20 northern hemisphere radiocarbon age calibration curve (0-55 cal kbp). radiocarbon, 62 (4), 725-757. ronchi l., fontana a., correggiari a. (2018a) characteristics and potential application of holocene tidal inlets in the northern adriatic shelf (italy). alpine and mediterranean quaternary, 31, 31-34. ronchi l., fontana a., correggiari a., asioli a. (2018b) late quaternary incised and infilled landforms in the shelf of the northern adriatic sea (italy). marine geology, 405, 47-67. rossi v., amorosi a., sarti g., potenza m. (2011) influence of inherited topography on the holocene 73 geographic variability of the millennial sea-level changes along the coasts of italy sedimentary evolution of coastal systems: an example from arno coastal plain (tuscany, italy). geomorphology, 135(1-2), 117-128. rovere a., raymo m.e., vacchi m., lorscheid t., stocchi p., gomez-pujol l., harris d.l., casella e., o'leary m.j., hearty p.j. (2016) the analysis of last interglacial (mis 5e) relative sealevel indicators: reconstructing sea-level in a warmer world. earth-science reviews, 159, 404427. roy k., peltier w.r. (2018) relative sea level in the western mediterranean basin: a regional test of the ice-7g_na (vm7) model and a constraint on late holocene antarctic deglaciation. quaternary science reviews, 183, 76-87. scardino g., piscitelli a., locuratolo g., scicchitano g., rizzo a. (2022) coastal quarries as relative sea-level markers: a methodological approach applied in the apulia region (southern italy). oceans, 3(2), 172-188. schmiedt g. (1972) il livello antico del mar tirreno. testimonianze da resti archeologici. leo s. olschki editore, firenze. scicchitano g., spampinato c.r., ferranti l., antonioli f., monaco c., capano m., lubritto c. (2011) uplifted holocene shorelines at capo milazzo (ne sicily, italy): evidence of co-seismic and steadystate deformation. quaternary international, 232(1 -2), 201-213. shennan i., horton b. (2002) holocene land‐and sea‐ level changes in great britain. journal of quaternary science, 17(5‐6), 511-526. shennan i., long a.j., horton b.p. (2015) handbook of sea-level research. john wiley & sons, chichester. soldati m., marchetti m. (2017) landscapes and landforms of italy. springer, cham. spada g., melini d. (2022) new estimates of ongoing sea level change and land movements caused by glacial isostatic adjustment in the mediterranean region. geophysical journal international, 229(2), 984-998. spampinato c.r., scicchitano g., ferranti l., monaco c. (2012) raised holocene paleo-shorelines along the capo schisò coast, taormina: new evidence of recent co-seismic deformation in northeastern sicily (italy). journal of geodynamics, 55, 18-31. stocchi p., spada g. (2009) influence of glacial isostatic adjustment upon current sea level variations in the mediterranean. tectonophysics, 474(1-2), 56-68. stocchi p., vacchi m., lorscheid t., de boer b., simms a.r., van de wal r.s., vermeersen b.l.a., pappalardo m., rovere a. (2018) mis 5e relative sea-level changes in the mediterranean sea: contribution of isostatic disequilibrium. quaternary science reviews, 185, 122-134. stuiver m., reimer p.j. (1993) calib rev. 8. radiocarbon, 35, 215-230. vacchi m., marriner n., morhange c., spada g., fontana a., rovere a. (2016) multiproxy assessment of holocene relative sea-level changes in the western mediterranean: sea-level variability and improvements in the definition of the isostatic signal. earth-science reviews, 155, 172-197. doi:10.1016/j.earscirev.2016.02.002 vacchi m., ghilardi m., melis r.t., spada g., giaime m., marriner n., lorscheid t., morhange c., burjachs f., rovere a. (2018) new relative sea-level insights into the isostatic history of the western mediterranean. quaternary science reviews, 201, 396-408. vacchi m., ermolli e.r., morhange c., ruello m.r., di donato v., di vito m.a., giampola d., carsana v., liuzza v., cinque a., boetto g., poveda p., boenzi g., marriner n. (2020a) millennial variability of rates of sea-level rise in the ancient harbour of naples (italy, western mediterranean sea). quaternary research, 93, 284-298. vacchi m., ghilardi m., stocchi p., furlani s., rossi v., buosi c., rovere a., de muro s. (2020b) driving mechanisms of holocene coastal evolution in the bonifacio strait (western mediterranean). marine geology, 427, 106265. vacchi m., joyse k.m., kopp r.e., marriner n., kaniewski d., rovere a. (2021) climate pacing of millennial sea-level change variability in the central and western mediterranean. nature communications, 12(1), 1-9. valenzano e. (2018) holocene morpho-sedimentary evolution of mar piccolo basin (taranto, southern italy). phd thesis, university of bari. pp. 120. valenzano e., scardino g., cipriano g., fago p., capolongo d., de giosa f., lisco s., mele d., moretti m., mastronuzzi g. (2018) holocene morpho-sedimentary evolution of the mar piccolo basin (taranto, southern italy). geografia fisica dinamica quaternaria, 41, 119-135. 74 mattei g. & vacchi m. ms. received: october 28, 2022 revised: january 24, 2023 accepted: february 3, 2023 available online: february 17, 2023 imp.milella& sea level during 4th – 2nd century b.p. in egnazia (italy) from archaeological and hydrogeological data maurilio milella 1, cosimo pignatelli 1, mario donnaloia 2 & giuseppe mastronuzzi 3 1 phd school of geomorphology and environmental dynamic, university of bari 2 sismological observatory, university of bari 3 department of geology and geophisics, university of bari abstract: milella m., pignatelli c., donnaloia m. & mastronuzzi g., sea level during 4th–2nd century b.p. in egnazia (italy) from archaeological and hydrogeological data (it issn 0394-3356, 2007). this paper aims to estimate the mean sea level position during the 4th–2nd cent. b.c. along the adriatic coast of apulia using archaeological and geomorphological data from the archaeological site of egnazia. the detailed topographic survey of wells, cisterns and tombs reported from giornali di scavo permitted us to reconstruct the probable groundwater piezometric surface in that period. two different scenarios have been considered. the first one considers the active state of wells: we added the value of 35 cm to the elevation of the well–bottom required in order to take water by means of jars. furthermore, we subtracted the same value to the elevation of the tomb / cistern–bottom because these structures couldn’t come into contact with groundwater. the second one considers the non–activity of wells: the dating of the wells, based on their replenishment, performed on ceramic fragments, indicates the time they were abandoned and the consequent transformation into dump. in this way only the values of well–bottoms for reconstructing the piezometric surface trend are used. the piezometric surface trend corresponding to the two hypothesis was reconstructed with arcmap 8.3 gis software through kriging interpolating method. sea level during 4th–2nd cent. b.c. stands at least -1,2 m present sea level. riassunto: milella m., pignatelli c., donnaloia m. & mastronuzzi g., livello del mare nel iv–ii secolo a.c. da dati archeologici e idrogeologici nell’area di egnazia (italia) (it issn 0394-3356, 2007). sec. a.c. lungo la costa adriatica della puglia nei dintorni della città di egnazia sulla base della ricostruzione del probabile andamento della superficie piezometrica della falda idrica di quel periodo. per questo studio sono stati utilizzati: i – rilievo topografico di dettaglio dell’area di egnazia; ii – la profondità dei pozzi e delle cisterne desunte dai giornali di scavo. e’ stato ricostruito il possibile andamento della superficie piezometrica della falda idrica dell’epoca in relazione a due differenti ipotesi di lavoro. la prima considera lo stato di esercizio dei pozzi: alle quote dei fondo–pozzi è stato aggiunto il valore di 35 cm, necessario a garantire il prelievo dell’acqua tramite vasi, mentre alle quote del fondo–tombe e cisterne è stato sottratto lo stesso valore di 35 cm, supponendo che tali strutture non dovessero essere a contatto con acque di falda. la seconda ipotesi presuppone l’interruzione dell’esercizio dei pozzi: infatti la datazione dei pozzi basata sul loro riempimento, costituito soprattutto da frammenti ceramici, indica il momento del loro abbandono e la conseguente trasformazione in “discariche”. in tal modo, per la ricostruzione dell’andamento della superficie della falda sono stati considerati esclusivamente i valori dei fondo–pozzi. attraverso il software arcmap 8.3 gis è stato ricostruito, mediante il metodo di interpolazione del kriging, l’andamento delle superfici piezometriche corrispondenti alle due ipotesi. si è potuto così ipotizzare che la posizione del livello del mare nel iv–ii secolo a.c. fosse almeno 1,2 m al di sotto della sua posizione attuale. keywords: sea level, holocene, archaeology, hydrogeology, puglia, italy. parole chiave: livello del mare, olocene, archeologia, idrogeologia, puglia, italia il quaternario italian journal of quaternary sciences 19(2), 2006 253-260 introduction in the mediterranean basin, indications of sea level stands during historical times can be obtained from geomorphological, biological and archaeological sources. particularly, in microtidal areas geomorphological data provide a valid tool to indicate the biological mean sea level within a few centimetres (paskoff & sanlaville, 1983; dalongeville, 1987; laborel & laborel deguen, 1994; pirazzoli, 1996) but it is difficult to date them because of the frequent absence of biogenic encrustations useful for radiometric analyses (auriemma et al., 2004). archaeological sites are a source of valuable data for reconstructing sea level changes. here radiometric data can be compared and confirmed by the archaeological chronology (erol & pirazzoli, 1992; stiros & pirazzoli, 1995; antonioli & leoni, 1998; fleming & webb, 1986; mourhange et al., 2001, sivan et al., 2001; auriemma et al., 2005). in the past, along the apulia coast there was an extensive colonisation due to humans especially in the areas characterised by stability of the landscape and the availability of fresh water. in particular, in the archaeological site of egnazia, located along the adriatic coast of apulia (fig. 1), the more ancient human settlement goes back to bronze age (16th cent. b.c.). its coast location, like several apulian protostoric settlements, made maritime activities easier because the jagged coastal area is suitable for docking and sheltering vessels which carried wares from transadriatic areas (cremonesi, 1979; sciarra bardaro–andreassi, 1982; auriemma et al., 2005). recent studies permit us to guess the egnazia settlement originated in the acropoli: an antropic–made low hill which spreads seaward between two small inlets, reached out into the 254 m. milella et al. hinterland occupying the area where the later roman age houses were found (dell’aglio, 1982). the egnazia economy was based mainly on ship commerce between the two sides of the adriatic sea: in fact, the town was an important merchant harbour and the wares were transferred by a track road network to the inner centres of apulia and lucania by the way of the traiana road. so egnazia represented an important crossroad and meeting point of the several aged cultures (donvito, 1988). it is possible to divide the urban space into three bands quite parallel to coastline (diceglie, 1981a, tav. i–v): the first one, the closest to coastal area, is related to maritime spaces and comprise caves, some messapica tombs and the ancient harbour; the second one, is located between the first and the traiana road, including the acropoli and public, religious and administrative buildings; the last one, situated to the south of the traiana road, including all civil buildings. beyond this third band, about 600 m inward from traiana road, there is the western necropoli area, used from the half of 4th cent. b.c. up to 4th cent. a.d. (fig. 1). the guidelines at the base of this work was originated by the assumption of the existence of sea level and land indicators (auriemma et al ., 2004). archaeological sea level indicators, such as harbour structures, fishery and so on, permit us to recognise with good approximation past sea level stands (antonioli & leoni, 1998). land indicators such as tombs, cisterns etc. at present below sea level indicate a minimum altitude under which sea level stood. the investigated hypothesis is that wells, cisterns and tombs in the coastal archaeological area of egnatia are useful to reconstruct the piezometric surface and to put in relation the sea level with the functioning of the wells. thus, the aims of this paper is to verify the availability of this method along rocky coasts and to define the error limit of the sea level identifications. regional settings the apulia region represents the emerged part of the foreland domain of both the apenninic and dinaric orogens. the apulian foreland is slightly deformed and is affected by nw–se and ne–sw trending faults that subdivided it into five structural domains: gargano area, tavoliere basin, murge upland, taranto–brindisi plain and salento peninsula. the uplift rate of the southernmost adriatic part of apulia, based on generic stratigraphic and morphological evidence, ranges between 0,15 and 0,19 mm/yr in the area around bari and about -0,02 mm/yr along the coastal area near brindisi (bordoni & valensise, 1998; ferranti et al., 2006). the archaeological area of egnazia is located on the adriatic coast of apulia between monopoli and fasano. here, at the feet of the murge plateau (locally about 400 m high) the coastal landscape is characterized by a sequence of sub–horizontal surfaces sloping towards sea from an elevation of about 120 m. these surfaces should be produced by marine abrasion phases which occurred since the middle pleistocene as a consequence of the superimposition of regional uplift and the glacio–eustatic sea level changes. the monotony of this landscape is broken by a relict drainage network characterized by deep valleys, locally named gravine or lame, generally parallel to each other and perpendicular to coastline, that were shaped for sapping processes (mastronuzzi & sansò, 2002a). the gently sloping rocky coast is marked by the presence of little inlets which guest pocket beaches; the present sea level is shaping a poorly developed wave cut platform locally alternated to a discontinuos notch. the stratigraphy of the egnazia area is characterized at the base by the presence of the calcare di bari unit (cretaceous), recognizable by drilling only, that represents the local basement, marked by karstic profig. 1 egnazia town: the different urban spaces are evidenced with bold lines (from cinquepalmi & cocchiaro, 2000, mod., 4, fig. 3). città di egnazia: in rilievo sono evidenziati i differenti spazi urbani (da cinquepalmi & cocchiaro, 2000, modificata, 4, fig.3). cesses. biocalcareous sandstone related to the calcarenite di gravina unit (lower pleistocene) (d’alessandro & iannone, 1984) overlies in transgression the limestone and outcrops extensively along the cost. therefore, this lithological sequence is characterized by a high permeability, due to fractures and karst. it causes the lack of a fluvial network due to the rapid rainwater infiltration: this feeds a wide deep aquifer that rests on seawater intruded from the nearby coastal area and its interface follows ghyben–herzberg principle. at present, in the inner part of murge plateau the piezometric surface reaches a maximum altitude of about +200 m m.s.l. sloping about 0,2÷0,8 % towards the coastline (cotecchia, 1977). bibliographic and field data processing to reconstruct the piezometric surface and the probable mean sea level during the 4th–2nd cent. b.c. along the egnazia coastal area the following data were used: i – archaeological and hydrogeological bibliographic data; ii – new detailed topographic survey of the entire egnazia area and the depth of wells and cisterns (fig. 2) inferred by digging journals (giornali di scavo). the piezometric level of the egnazia coastal area was reconstructed by means of bibliographic data (tanzarella, 1998; maggiore et al., 1999; maggiore & pagliarulo, 2004). in 1997, the piezometric level in the archaeological park area was about +0,12 m present b.s.l. whereas it was at +2,5 m present b.s.l. about 5200 m landward (tanzarella, 1998). moreover, the bibliographic check allowed us to obtain data on the typology and the depth of the archaeological structures, wells and cisterns, used as indicators for this study. furthermore, the dating of the same indicators carried out by means of ceramic replenishment were taken on. wells and cisterns have a good distribution in the entire area of the ancient egnazia, inside the archaeological park area and outside, along the coast and inside the western necropoli. a well represents a vertical hole dug by humans (fig. 3) with a depth of about 30 ÷ 40 cm below piezometric surface useful for collecting water by jars (sivan et al., 2001). instead, cisterns were used only to keep rainwater and groundwater withdrawn through wells: so their bottoms did not reach the piezometric surface (cocchiaro, 1982; tagliente, 2005). during archaeological surveys, 70 structures for water supplies were localized (fig. 4): 52 inside the present archaeological park area and 18 along coastal area. unluckily, only 10 structures out of the first group and 8 structures out of the second one, in particular wells and cisterns to the south of the acropoli, show enough data from digging journals about their depth. in particular, wells located inside the archaeological park area surrounding traiana road, have a mean depth of about 3 m; while the ones situated near coastline have a mean depth of about 1,8 m. among the 10 structures of archaeological park 1 dates back to 9th cent. b.c., 4 to 4th cent. b.c., 2 to 3rd cent. b.c., 2 to 2nd cent. b.c. and 1 to 1st cent. a.d.; all the 8 structures of coastal area to the south of acropoli date back to 255sea level during 4th 2nd century b.p. ... fig. 2 detail of a cistern entrance in the archaeological park area (cinquepalmi & cocchiaro, 2000, 16, fig. 37). particolare dell’imboccatura di una cisterna nell’area del parco archeologico (da cinquepalmi & cocchiaro, 2000, 16, fig. 37). fig. 3 well scheme: in the vertical sections 4 cavity for each side, named “pedarole”, can be distinguished. in the lower part a vertical sub-rectangular cavity opens (from digging journals). schema di un pozzo: nelle sezioni verticali si possono distinguere 4 cavità per ciascun lato, chiamate “pedarole”. nella parte più bassa si apre una cavità subrettangolare (dai giornali di scavo). 256 2nd cent. b.c. (tagliente, 2005). only the structures dating back to 4th–2nd cent. b.c. have been considered for this study. detailed topographic survey was carried out by total station (teodolite “wild t2” with a geodimeter “aga 14a”); it let us get spatial coordinates related to gauss boaga system datum ed 50 (x, y and z) of al l the wells, cisterns and tombs inside egnazia area and depth of all the tombs inside western necropoli. z–elevations were related to the present biological sea level (= b.s.l.) (laborel & laborel deguen, 1994) thanks to the presence of living concretions of lithophyllum lichenoides and dendropoma sp. along the coastal inlets near the acropoli; this occurrence allows us to evaluate in +/0,10 m the error bar of shown data. so, in the area of the archaeological park near traiana road the mean elevation of well heads is about +4,8 +/0,10 m present b.s.l., while along the coastline the mean elevation of well heads does not go over +1,5 +/0,10 m present b.s.l.. the spatial coordinates of al l the surveyed points (wells, cisterns and tombs) elaborated using software (surfer 8 and arcmap 8.3 gis – kriging method) permit us to draw a map where topography and the piezometric surface of egnazia area are shown (figg. 4, 5). the piezometric surface was reconstructed according to two hypothesized scenario. the a scenario considers the active state of wells: we add the value of 35 cm to the elevation of the well–bottom required to take water by means of jars (sivan et al., 2001); on the contrary, we subtracted the same value to the elevation of the tomb and cistern bottom because these structures could not come into fig. 4 topography restitution of egnazia town, by means of surfer 8 software, with contour lines. ox : archaeological points; __: contour lines; _: coastline; ab: hydrogeological section track. ricostruzione, ottenuta con il software surfer 8, dell’andamento plano–altimetrico dell’area di egnazia mediante curve di livello. ox : punti archeologici; __: curve di livello; _: linea di costa; ab: traccia della sezione idrogeologica. fig. 5 piezometric surface restitution of egnazia town, by means of arcmap 8.3 gis software, for b scenario. ox : archaeological points; __: contour lines; _: coastline; ab: hydrogeological section track. ricostruzione, ottenuta con il software arcmap 8.3 gis, dell’andamento della superficie piezometrica nell’area di egnazia nel caso dello scenario b. ox : punti archeologici; __: curve di livello; _: linea di costa; ab: traccia della sezione idrogeologica. m. milella et al. 257 contact with groundwater. the use of this value allows us to obtain the best extrapolation of the piezometric surface trend so that its slope is coherent with the one of the uptodate groundwater. the b scenario considers the non–active state of wells: the dating of wells based on their replenishment, obtained by means of ceramic fragments, indicates the time they were abandoned and consequent transformation into dump. in this way only the values of well bottoms for reconstructing the piezometric surface trend were used (fig. 5). according to these hypothesis, either real hydrogeological sections or theoretical best–fitted on 2° degree equations extrapolations, were obtained (figg. 6a,b). discussion auriemma et al. (2004; 2005) reconstructed a curve of relative sea level changes in ancient time using geomorphological, archaeological and radiometric data. in particular, in the inlet north to the acropoli submerged piers in opus caementicium of the roman age are present. these structures and the building techniques indicate that sea level stands at about -2,5 m present b.s.l. during the 1st cent. b.c.. hydrogeological section, “a–b”, made up for both the work scenario reaches out about 800 m from the south limit of western necropoli to the present coastline in front of acropoli (fig. 4). some uncertainties derive from the historical and bibliographical sources: depth of wells and cisterns, taken from digging journals, have not been ascertained because of their replenishment and / or covering protection following the archaeological digging surveys. in particular, in the archaeological park, differences of depth have been recognized: the bottom of one cistern is about 0,5 m deeper than the bottom of very close coeval wells; bottoms of wells of coeval age, up to 30 m close, fig. 6a real hydrogeological section and theoretical best – fitted on 2° degree equation extrapolation for a scenario. the rectangle represents the present archaeological park area. 1 = past piezometric level; 2 = present piezometric level; 3 = past extrapolation level based on “y” 2° degree equation. sezione idrogeologica reale e relativa estrapolazione teorica ottenuta mediante equazione di 2° grado, nel caso dello scenario a. il rettangolo corrisponde all’area del parco archeologico. 1 = livello piezometrico passato; 2 = livello piezometrico presente; 3 = estrapolazione del livello piezometrico passato sulla base dell’equazione di 2° grado “y”. fig. 6b real hydrogeological section and theoretical best – fitted on 2° degree equation extrapolation for b scenario. the rectangle represents the present archaeological park area. 1 = past piezometric level; 2 = present piezometric level; 3 = past extrapolation level based on “y” 2° degree equation. sezione idrogeologica reale e relativa estrapolazione teorica ottenuta mediante equazione di 2° grado, nel caso dello scenario b. il rettangolo corrisponde all’area del parco archeologico. 1 = livello piezometrico passato; 2 = livello piezometrico presente; 3 = estrapolazione del livello piezometrico passato sulla base dell’equazione di 2° grado “y”. sea level during 4th 2nd century b.p. ... 258 show differences of depth of about 0,8÷1,0 m. to overcome this discrepancy the extrapolated piezometric level, for both scenarios, has been considered (curve 3 in figg. 6a,b). the scenario a (active state of wells) suggest a piezometric level between about +1,15 m present b.s.l. along traiana road and about -0,8 m present b.s.l. on coastline. the scenario b (non–active state of wells) indicate a piezometric level between +0,75 m present b.s.l. in the archaeological park and -1,2 m present b.s.l. along the coast (tab. 1). assuming the position of sea-level stand at -0,8 or at –1,2 m during 4th–2nd cent. b.c. in both scenario the piezometric level of +1,95 m past b.s.l. along traiana road results. this value is too high and incongruous for the topographic and hydrogeologic features of egnazia area (tab.1). in fact the archaeological park is located only 250 m landward and in the last 30 years the piezometric level went down about 15% due to human activity (polemico & dragone, 1999). since the climatic state during 4th–2nd cent. b.c., it was not very different in comparison with the present time (mastronuzzi & sansò, 2002b) the past piezometric level could not be much different in comparison with the present trend too. the present piezometric surface in the egnazia area has a mean slope of 0,048%: it is quite steady up to 5200 m landward. in the curve 3 of figg. 6a,b it is possible to detect two sketches characterized by different slope. sketch 1, from western necropoli to traiana road, has a mean slope of about 0,076% and 0,073%, respectively for a and b scenario. sketch 2, from traiana road to coastline, has a mean slope of about 0,77% and 0,76%, respectively for a and b scenario. only the values obtained for the sketch 1 can be compared with the present piezometric mean slope. using the mean slope of sketch 1 the values of +0,19 m and +0,18 m, respectively for a and b scenario, result: these values should be the piezometric level in the archaeological park referred to every stand of past sea level. the piezometric levels calculated and the present one of +0,12 m b.s.l. (tanzarella, 1998) can be brought into comparison. thereby, the piezometric surface during 4th–2nd cent. b.c. along traiana road had to stand necessarily about 1,6 m below the wells–bottom (tab. 2). the archaeological park is only 250 m far from the coastline: according to the present hydrogeological features the piezometric surface near traiana road did not have to overcome the elevation of about +0,2 m past sea level. mean elevation of the wells–bottom is about 1,6 m above this piezometric surface. consequently, the wells of this area could not operate during 4th–2nd cent. b.c., according to the b scenario. thus, the reconstruction of the piezometric surface allowed us to estimate that sea level during 4th–2nd cent. b.c. had to stand at least -1,2 m present b.s.l. (fig. 7). in any case, the available data and the results of archaeological park area coastline past piezometric present past piezometric level related to past piezometric surface piezometric surface related to cisterns related to related to surface present b.s.l. wells / tombs past sea present related to = past sea level bottom bottom level b.s.l. present b.s.l. position (+/0,10 m) a hypothesis: activity +0,35 m -0,35 m +1,95 m +1,15 m +0,12 m -0,8 m b hypothesis: non – activity 0 m -0,35 m +1,95 m +0,75 m +0,12 m -1,2 m sketch 1: a – 19 sketch 2: 19 – b archaeological park area present past piezometric past piezometric past piezometric surface mean surface mean present piezometric surface mean slope from slope from piezometric level slope along necropoli to@ traiana road to level calculated by ab section traiana road coastline sketch 1 slope a hypothesis: activity 0,048% 0,076% 0,77% +0,12 m +0,19 m b hypothesis: non – activity 0,048% 0,073% 0,76% +0,12 m +0,18 m tab. 1 comparison among extracted levels for past and recent piezometric surface along different areas of egnazia town. confronto tra i livelli ricavati per le superfici piezometriche passata e attuale in differenti zone della città di egnazia. tab. 2. comparison among extracted slopes and relative levels for present and past piezometric surface along different sketches of ab section in egnazia area. confronto tra i valori delle pendenze medie e dei relativi livelli ricavati per le superfici piezometriche presente e passata in corrispondeza di differenti tratti della sezione ab nell’area di egnazia. m. milella et al. elaboration indicate a relative sea level change lower than supposed by auriemma et al. (2004; 2005). unluckily, they do not permit us to recognize the eustatic and/or tectonic contribution although the entire area where egnazia is located, is considered by some authors in slow downlift (mastronuzzi & sansò, 2002a; lambeck et al., 2004). moreover, this reconstruction fits in well with some recent surveys that, in coastal areas, individuate the bottom of messapic tombs up to -1,1 m present b.s.l.. therefore taking into account that some eastern necropoli coastal tombs and egnazia roman harbour structures stay currently below the present b.s.l. (auriemma et al., 2004) it is unlikely that messapic people used to bury dead people at the seaside, where storms and spray could reach the tombs. conclusion the aim of this work was to estimate the relative position of the sea level during 4th–2nd cent. b.c. by means of archaeological data from egnazia. news and bibliographic data permit us to imagine the trend of the piezometric surface related to 4th–2nd cent. b.c.; two hydrogeological sections respectively based on two different scenarios have been implemented. according to the suggestions derived by sivan et al. (2004), the first one considers the active state of wells adding the value of 35 cm to the elevation of the well–bottom and subtracting the same value to the elevation of the tomb / cistern–bottom. the second one considers the state of abandoning of wells. data and discussion shown in these pages indicate that wells, cisterns and tombs dug in coastal areas could be used in the reconstruction of piezometric surface and related sea level with prudence. in fact, pottery remains inside do not indicate necessarily the age of their use but more probably their use as a dump. moreover, when using bibliographic data, their accuracy needs to be verified, in particular in the evaluation of deep values. as a consequence the error limit of this method on rocky coast should be bigger than the 0,10 m supposed in previous pages or the 0,10÷0,20 m supposed by sivan et al. (2001) for sandy coasts. in summary, the shown data and the reconstructions obtained indicate that: i – the wells were dug in times before the 4th–2nd cent. b.c.; ii – the wells were abandoned and filled at least at the beginning of the 4th century; iii – the piezometric level during the 4th–2nd cent. b.c. ran at about 1,6 m below the wells-bottom; iv – the sea level during the 4th–2nd cent. b.c. was at least -1.2 m present one. the discrepancy between this last data and that indicated by the presence of the submerged harbour structure is only apparent; in fact, the value -1,2 m is a limit lower than the sea could stand and it is heavily conditioned by the approximation of data registered and derived by digging journals. acknowledgements we would like to thank anonymous reviewers for constructive criticism and useful suggestions, dott. rossella pagliarulo from cnr – bari and dott. vittoria tagliente for the helpful discussions. this work was financially supported by national project archeomar by ministero dei beni e delle attività culturali (project leaders: dott. l. fozzati; dott. c. mocchegiani carparo; leader of puglia unit: g. mastronuzzi). this is an italian contribution to the igcp project n.495 – international geological correlation programme “quaternary land-ocean interactions: driving mechanisms and coastal responses ” dell’unesco – iugs (project leader: dr. anthony long, university of durham, uk). 259 fig. 7. : curve of sea level change during the last 3000 years in southern apulia reconstructed from auriemma et al. (2004) data; … : curve of sea level change during the last 3000 years according to the past piezometric surface in egnazia area. ▲ : sea level during 4th 2nd cent. b.p. deducted by piezometric level in archaeological elements (wells, cisterns and tombs). curva della variazione del livello del mare durante gli ultimi 3000 anni lungo la puglia meridionale ricostruita in base agli indicatori di auriemma et al. (2004); … : curva della variazione del livello del mare durante gli ultimi 3000 anni secondo la ricostruzione della superficie piezometrica del passato nell’area di egnazia. ▲ : livello del mare durate il vi ii sec. a.c. dedotto dalla superficie piezometrica ricavata dagli elementi archeologici (pozzi, cisterne e tombe). sea level during 4th 2nd century b.p. ... references andreassi g., cocchiaro a & maruca a. (2000) egnazia sommersa: dalla terra al mare. ministero per i beni e le attività culturali, soprintendenza archeologica della puglia. c.d.s. valenzano, bari. antonioli f. & leoni g. (1998) siti archeologici sommersi e loro utilizzazione quali indicatori per lo studio delle variazioni recenti del livello del mare. il quaternario, 11 (1), 53 – 66. auriemma r., mastronuzzi g. & sansò p. (2004) middle to late holocene relative sea-level changes recorded on the coast of apulia (italy) . geomorphologie: relief, processus, environnement, 1, 19 – 34. auriemma r., mastronuzzi g., sansò p. & zongolo f. (2005) the harbour of the mansio ad speluncas (brindisi, italy): a key to the lecture of sea level changes in the past 3500 years?. in maritime heritage and modern ports, wit press 2005, 5 – 14. bordoni p. & valensise g. (1998) deformation of 125 ka marine terrace in italy: tectonic implications. in stewart i.s., vita-finzi c. (eds.) coastal tectonics. geological society special publications, london, 146, 71 – 100. caldara m. & pennetta l. (1995) lineamenti del clima nell’età del bronzo lungo la fascia adriatica pugliese. in: atti del seminario di studi: l’età del bronzo lungo il versante adriatico pugliese, bar 1995, taras xv, 2, 21 – 37. cinquepalmi a. & cocchiaro a. (2000) egnazia nel tempo. dal villaggio protostorico al borgo medioevale. valenzano 2000. cocchiaro a. (1982) i pozzi, le vasche, le cisterne. in: mare d’egnazia, fasano 1982, 93 – 106. cocchiaro a. (1997) fasano (brindisi), egnazia. in: taras, xvii, 1, 56 – 58. cotecchia v. (1977) studi e ricerche sulle acquee sotterranee e sull’ intrusione marina in puglia (penisola salentina). quad. ist. ric. sulle acque, 20, 1 – 34. cremonesi g. (1979) l’età del bronzo nella puglia meridionale. in: aa. vv. la puglia dal paleolitico al tardo – romano, milano 1979, 179 – 192. dalongeville r. (1987) le beach-rock. travaux de la maison de l’orient méditerranéen, lyon, 8, 197 pp. d’alessandro a. & iannone a. (1984) prime considerazioni sedimentologiche e paleoecologiche su alcune sezioni della calcarenite di gravina (pleistocene) nei pressi di monopoli. in studi di geologia e geofisica. 27, 1 – 16. dell’aglio a. (1982) i segni dell’insediamento protostorico. in: mare d’egnazia, fasano 1982, 29 – 36. diceglie s. (1981) gnathia. forma della città delineata mediante la prospettiva archeologica con 5 tavole allegate. fasano, 1981. donvito a. (1988) egnazia. dalle origini alla riscoperta archeologica. fasano, 1998. erol o. & pirazzoli p. a. (1992) seleucia pieria: an ancient harbour submitted to two successive uplift. the international journal of nautical archaeology, 21 (4), 317 – 327. flemming n.c. & webb c. o. (1986) tectonic and eustatic coastal changes during the last 10,000 years derived from archaeological data . zeitschrift für geomorphologie n.f., suppl. bd., 62, 1 – 29. laborel j. & laborel deguen f. (1994) biological indicators of relative sea – level variations and of co – seismic displacements in the mediterranean region. journal of coastal research 1994, 10, pp. 395 – 415. lambeck k., antonioli f., purcell a. & silenzi s. (2004) sea–level change along the italian coast for the past 10,000 yr. quaternary science reviews, 23, pp. 1567 – 1598. mastronuzzi g. & sansò p. (2002a) pleistocene sealevel changes, sapping processes and development of valley networks in the apulia region (southern italy). geomorphology, 46, 19–34. mastronuzzi g. & sansò p. (2002b) holocene coastal dune development and environmental changes in apulia (southern italy). sedimentary geology, 150, 139 – 152. morhange c., laborel j. & hesnard a. (2001) changes of relative sea level during the past 5000 years in the ancient harbour of marseilles, southern france. palaeogeography, palaeoclimatology and palaeoecology, 166, 319 – 329. paskoff r & sanlaville p. (1983) le côte de la tunisie, variation du niveau marin depuis le tyrrhènien. maison de l’orient méditerranéen, lyon, 192 pp. pirazzoli p. a. (1996) sea-level changes. j. wiley & sons, chichester, 211 pp. polemio m. & dragone v. (1999) serie storiche piezometriche delle unità idrogeologiche pugliesi: regime piezometrico, effetti climatici ed antropici. pubbl. gndci n. 2015, quaderni di geologia applicata, pitagora editrice, bologna, 1999, 4, 153 – 162. sciarra bardaro b. & andreassi g. (1982) il porto. in: mare d’egnazia, fasano 1982, 107 – 118. sivan d., wdowinski s., lambeck k., galili e. & raban a. (2001) holocene sea-level changes along the mediterranean coast of israel, based on archaeological observations and numerical model. in: palaeogeography, palaeoclimatology, palaeoecology, 167, 101 – 117. stiros s. c. & pirazzoli p. a. (1995) paleoseismic studies in greece: a review. quaternary international, 25, 57 – 63. tagliente v. (2005) problemi di approvvigionamento idrico ad egnazia. tesi di specializzazione in archeologia e storia dell’arte romana, a.a. 2003/2004. tanzarella v. (1998) idrogeologia della fascia costiera adriatica compresa tra l’abitato di fasano (br) ed il mare. tesi di laurea in scienze geologiche, università degli studi di bari, a.a. 1997/1998. 260 ms. ricevuto il 20 febbraio 2006 testo definitivo ricevuto il 31 ottobre 2006 ms. received: february 20, 2006 final text received: october 31, 2006 m. milella et al. imp.lecca& i sedimenti terrigeno-carbonatici attuali della piattaforma continentale del golfo di cagliari luciano lecca1, sandro de muro1, michele cossellu1 & mauro pau2 1dipartimento di scienze della terra, università di cagliari, via trentino 51, 09127, cagliari 2c/o faculty of physics and astronomy, princetonplein 5, postbus 80.000, 3508 ta-utrecht, the netherlands. riassunto: lecca l., de muro s., cossellu m. & pau m., i sedimenti terrigeno-carbonatici attuali della piattaforma continentale del golfo di cagliari. (it issn 0394-3356, 2005). nuove indagini ecografiche e sedimentologiche sono state intraprese nella piattaforma di cagliari con gli obiettivi di riconoscere il rapporto tra la sedimentazione terrigena e quella carbonatica, e di individuare il comportamento del sistema sedimentario durante la risalita eustatica olocenica. ad integrazione di dati già disponibili, il rilevamento ecografico, consistente di 11 nuove linee eseguite trasversalmente alla costa da riva fino al bordo della piattaforma, ha permesso di distinguere diversi ambienti sedimentari. la spiaggia sottomarina, sabbiosa e priva di vegetazione nella parte superiore e colonizzata da basse fanerogame e posidonia in quella inferiore, termina in una depressione della piattaforma interna, disposta circa parallelamente alla linea di costa. verso il largo, oltre la depressione, seguono una fascia in rilievo, sede del banco principale a posidonia e il pendio esterno al banco, a vegetazione diradata sotto la profondità di 30 metri. nel pendio esterno si osserva una fascia a onde di sabbia di altezza e lunghezza decrescenti verso il largo, fino alla profondità di circa 50 m dove prevalgono fondali planari, interrotti da bassi rilievi allungati riconducibili a paleo-linee di riva sommerse. esternamente alle paleo-rive è presente una stretta piattaforma esterna fino a circa –115÷125 m. la depressione in piattaforma interna e il rilievo di media piattaforma, sono interpretabili come antecedenze residuali della regressione “würmiana” (mis 4-2, paleo-erosione fluviale e paleo rilievo). sul paleo-rilievo si sono sovrapposti sedimenti di spiaggia sottomarina e infine il banco a posidonia debolmente aggradante e progradante, contestualmente ad un apporto terrigeno insufficiente a colmare lo spazio disponibile nella depressione prodotto dalla trasgressione post-glaciale. complessivamente sono state eseguite 98 campionature lungo le linee ecografiche e in battigia. le analisi granulometriche e composizionali semi-quantitative hanno consentito di riconoscere 8 gruppi di litofacies che documentano le caratteristiche dei diversi ambienti deposizionali. il sedimento silicoclastico attuale è confinato in piattaforma interna, dove si depongono sabbie da molto grosse a medio-fini che gradano lateralmente a sabbie molto fini e fanghi nelle depressioni. in piattaforma intermedia la produttività carbonatico-bioclastica del banco a posidonie (molluschi, briozoi, alghe rosse, echinidi e foraminiferi) dà luogo a facies bioclastiche e miste per la contemporanea presenza di sedimenti terrigeni relitti derivati dall’erosione del mare in risalita a spese di depositi di precedenti fasi eustatiche. distalmente il sedimento è in prevalenza carbonatico (alghe rosse e foraminiferi) con rari affioramenti di sedimenti misti in prossimità delle paleo-rive. la facies più distale osservata in piattaforma esterna è caratterizzata da sabbie medio-fini quarzoso-bioclastiche a lamellibranchi e foraminiferi. l’insieme delle litofacies campionate documenta che tale piattaforma ha una sedimentazione mista, terrigena e carbonatica, di mare temperato. la componente bioclastica è attribuibile all’attuale produttività in piattaforma intermedia e distale dove è prevalente, mentre la componente terrigena proviene nella spiaggia sottomarina dall’alimentazione fluvio-continentale attuale ordinata dal moto ondoso, in piattaforma intermedia e distale da sedimenti terrigeni relitti. un contesto sedimentologico analogo deve essere attribuito alle precedenti fasi di alto stazionamento eustatico del pleistocene medio-superiore. diversamente, durante le precedenti fasi glacio-eustatiche di abbassamento, stazionamento basso e risalita, la piattaforma è stata interessata da sedimentazioni terrigene emerse o di spiaggia sottomarina che vengono attualmente ri-sedimentate in piattaforma intermedia e distale. pertanto il modello deposizionale di questa piattaforma risulta costituito da fasi terrigeno-carbonatiche di mare temperato, durante la diminuzione dell’alimentazione terrigena per risalita e alto eustatico e clima mediterrano caldo poco piovoso, alternate a fasi maggiormente terrigene durante i periodi di mare basso e clima mediterraneo più fresco e più piovoso. abstract: lecca l., de muro s., cossellu m. & pau m., modern terrigenous-carbonate sediments of the continental shelf of the gulf of cagliari. (it issn 0394-3356, 2005). echographic and sedimentological investigations were undertaken on the shelf of cagliari with the purpose of underlining the relationships between modern terrigenous and bioclastic sediments and the behaviour of the sedimentary system during the holocene eustatic rising. the gulf of cagliari is a sub-tropical, semi-arid mediterranean area located in the southern part of the nw striking oligomiocene sardinian rift, within which the pliocene campidano graben is superimposed. the quaternary continental shelf developed transversally to this tectonic trough, being fed by terrigenous sediments derived from the palaeozoic metamorphic basement and from tertiary sedimentary and volcanic rocks. the new echographic survey, consisting of 11 lines performed transversally from the coast to the shelfbreak, integrated previously available data and allowed us to divide the shelf into different sedimentary environments. from shore to shelfbreak we first encounter a shoreface, gently sloped and distally seagrass-covered (close to the fair-weather wave base), which ends in a wide trough parallel to the coast. toward the open shelf is a relief, site of the posidonia oceanica main bank, reaching a minimum depth of 13 meters under the sea level, followed by its external slope. at a depth of about 30 meters the vegetation becomes rare, as less luminosity limits the growth of posidonia, and starting from depths of 35÷40 meters a large belt of sand waves appears, with gradually decreasing heigths and increasing frequencies basinward. at the depth of 50 m a flat bottom prevails, followed by several reliefs stretching roughly ne–sw at 55 m depth, interpreted as submerged shore lines. externally to such structures a narrow outer shelf occurs and the shelf break is observed at a depth of 115÷125 m. sampling sites were located along the echographic lines and on the foreshore; 98 samples were taken with a 2 dm_ grab-sampler. compositional and grain size analysis allowed us to identify 8 groups of facies related to present day depositional environments. shoreface sediments are represented by almost completely terrigenous coarse to medium sands in the eastern sector, and finer mixed terrigenous-bioclastic sands on the s. gilla shoreface. two distinct groups of lithic facies are present near capo s. elia and near p.ta zavorra, due to sediment dispersal from the limestone and andesite outcrops along the cliffed coast. the western inner-shelf depression is characterized by mixed quartzose-bioclastic sandy muds with bivalves. mixed facies of relict terrigenous sediments and present day biogenic production (mollusks, bryozoans, red algae, echinoids and foraminifers) are on the posidonia oceanica bank’s fore slope, where the siliciclastic component is found between -30 and -50 meters with decreasing importance seaward. through the sand-wave belt a transition is observed to bioclastic, poorly sorted gravely sands of red algae and foraminifers. here the sediment is completely bioclastic with rare breakthroughs of mixed sediments in proximity to the –55 m paleo-shores. from a depth of 75 meters, sediments are represented by fine bioclastic-quartzose sands with bivalves and foraminifers. a peculiar feature of this shelf is the depression in the inner shelf that can be interpreted as the product of il quaternario italian journal of quaternary sciences 18(2), 2005 201-221 202 l. lecca et al. 1. introduzione 1.1 premessa la piattaforma continentale del golfo di cagliari è stata recentemente oggetto di descrizione alla scala dell’intero bacino di cagliari (lecca et al., 1998), di studi di dettaglio in aree campione (de muro & kalb, 2003) e di valutazioni geologico-applicative finalizzate al ripascimento della spiaggia del poetto che ha suscitato accese discussioni in sedi non scientifiche. in questo lavoro, trascurando volutamente gli aspetti applicativi, si presenta la descrizione dei sedimenti, delle strutture e dei processi che costituiscono il sistema deposizionale attuale. tenuta presente l’importanza che la sedimentazione carbonatica delle zone a clima temperato (lees & buller, 1972; adey & macintyre, 1973; lees, 1975; carannante et al., 1988; pomar, 2001; pomar et al., 2004) ha avuto nei tempi neogenici e quaternari in mediterraneo (burollet, 1981; colantoni et al., 1993; fornos & ahr, 1997) e in sardegna (carboni et al, 1989; carboni & lecca, 1992; lecca et al., 1998; cherchi et al., 2000), tale tipo di sedimentazione è stata descritta e interpretata nella attuale piattaforma del golfo di cagliari. allo scopo di pervenire ad una prima sintesi alla scala dell’intera piattaforma, sono state eseguite una copertura di profili ecografici, una campionatura e le analisi sedimentologiche che hanno permesso di evidenziare, in particolare, le relazioni tra la sedimentazione terrigena dello shoreface (spiaggia sottomarina) e quella carbonatico-bioclastica della piattaforma intermedia ed esterna. 1.2 elementi geologico-regionali il golfo di cagliari è ubicato nella parte meridionale del rift sardo oligo-miocenico all’interno del quale, come è noto, si è sovrimposto i l graben del campidano (pecorini, 1966; pecorini & pomesano cherchi, 1969; cherchi & montadert, 1982; casula et al, 2001; finetti et al., 2005). questo golfo si apre verso il margine continentale della sardegna meridionale dove è attivo un sistema sedimentario sottomarino composto da una piattaforma continentale, una scarpata e da diversi bacini di scarpata che contribuiscono a loro volta alla sedimentazione della piana abissale sardoalgerina (lecca et al., 1998). nella parte più interna di tale sistema sedimentario è ubicato il bacino di cagliari che rappresenta la prosecuzione del rift sardo, riattivata durante il plio-quaternario contestualmente all’apertura del tirreno. questo bacino, controllato nei tempi pliocenico-quaternari dai movimenti dei blocchi tettonici della sardegna meridionale (sulcis e sarrabus) e dai blocchi sottomarini di su banghittu e del monte ichnusa (fig. 1), è composto da una relativamente ampia piattaforma continentale, da un pendio e da una parte profonda fino a circa – 800÷1000 m (fig. 2). nella regione emersa prospiciente il golfo possono essere individuate due parti strutturalmente omogenee che proseguono nella infrastruttura della piattaforma continentale. la parte orientale comprende i promontori calcarei di cagliari e funge da horst orientale del graben del campidano, a est del quale si erge il più antico horst del rift sardo (horst del sarrabus). la parte occidentale è costituita dalla prosecuzione del graben del campidano, limitato a ovest dall’ horst del sulcis e colmato da diverse centinaia di metri di sedimenti clastici fluviali e marino-transizionali-litorali plioquaternari, derivati dalla erosione delle sequenze mioceniche del rift e delle formazioni paleozoiche. paleo-river erosions produced during the “würmian” low stand (mis 4-2), associated with terrigenous inputs insufficient to fill up the available space during the post-glacial sea level rise. towards the middle shelf the trough is bounded by paleo-reliefs where the posidonia bank at present overgrows, weakly aggrading and prograding. the depositional facies described document the present day sedimentary system as of a temperate water mixed terrigenous-carbonate shelf. the sedimentation is highly siliciclastic in the inner shelf from fluvial-continental feeding, and bioclastic in the rest of the shelf with a maximum productivity along the intermediate shelf’s posidonia bank and its foreslope. in the middle and outer shelf the siliciclastic component is related to previous eustatic phases and attributable to continental and nearshore deposits lying underneath the middle-shelf posidonia bank. analogous depositional contexts must be attributed to the preceding high stand phases of the middle-upper pleistocene. otherwise, during glacio-eustatic phases of falling, low-stand and rising sea level, the shelf has been affected by terrigenous continental sedimentation or shoreface sequences that are currently resedimented in the middle and outer shelf. in summary, the depositional model of this shelf is characterised by alternating phases of terrigenous-carbonate sedimentation of middle latitude, with a poorly rainy, warm mediterranean climate during highstanding sea-level conditions, and terrigenous phases during low stands with rather rainy, cooler mediterranean climate. parole chiave: piattaforma continentale, sedimenti terrigeno-carbonatici, sedimenti relitti, posidonia oceanica, variazioni eustatiche, quaternario, sardegna. keywords: continental shelf, terrigenous-carbonate sediments, relict sediments, posidonia oceanica, sea level change, quaternary, sardinia. fig.1 schema geologico della sardegna meridionale e ubicazione dell’area studiata. geological sketch of southern sardinia and location of the studied area. 1.3 la piattaforma del golfo di cagliari la piattaforma continentale del golfo di cagliari, ubicata trasversalmente al rift sardo oligo-miocenico della sardegna meridionale, dal punto di vista strutturale e sedimentologico risulta costituita dalla congiunzione di tre diversi segmenti: la terminazione orientale della piattaforma del sulcis, la piattaforma di cagliari s.s., che costituisce la parte più importante, e la stretta piattaforma del sarrabus (fig. 2). i tre segmenti di piattaforma vengono alimentati da apporti terrigeni, di cui non sono disponibili valutazioni quantitative, provenienti da tre diverse aree. il sarrabus, costituito in prevalenza da metamorfiti erciniche di basso grado, da plutoniti tardo erciniche e, nella regione costiera, da sequenze clastiche continentali e marine mioceniche e quaternarie. il sulcis, dove affiorano in genere rocce del basamento ercinico, localmente coperture sedimentarie paleogeniche terrigene e, in prossimità della faglia occidentale del graben del campidano, importanti apparati vulcanici andesitici oligo-miocenici. infine l’area di cagliari, la cui parte orientale è costituita da marne e marne arenacee del miocene inferiore e medio e da arenarie e calcari di piattaforma bioclastico-algale del miocene superiore, e quella occidentale costituita dai complessi continentali e transizionali-litorali pliocenicoolocenici del campidano meridionale. le prime descrizioni di questa piattaforma risalgono a segre (1968), che al di sotto dei sedimenti attuali riconobbe elementi morfologici riconducibili alla risalita eustatica del pleistocene superiore-olocene, e alle indagini eseguite mediante la nave oceanografica bannock (c.n.r.) dall’università di genova che consentirono le prime descrizioni sedimentologiche (piccazzo et al., 1981). sulla base di nuovi rilievi ecografici e sismici, realizzati nell’ambito del progetto oceanografia 203i sedimenti terrigeno carbonatici ... e fondi marini-cnr (carta et al., 1986), e di successive ricerche, seguirono descrizioni di dettaglio dei paleodepositi litorali interpretati come beach rock (ulzega et al. 1986; de muro & orrù, 1998). l’architettura complessiva della piattaforma di cagliari, ricostruita principalmente sulla base di linee sub-bottom profiler e sparker 500 j, risulta costituita da tre accrescimenti debolmente progradanti: uno sil icoclastico di shoreface, uno bioclastico della media piattaforma e infine uno fangoso della piattaforma esterna-pendio, all’interno di un bacino estensionale (lecca et al.,1998). tali progradazioni sono state attribuite ad ambienti deposizionali distinti, attivi contemporaneamente e relativi allo stazionamento alto (high stand) tardo olocenicoattuale, che mostrano alimentazioni sedimentarie, facies e fattori di controllo diversi. la sezione più completa di tale piattaforma mostra una sequenza di ambienti, disposti circa parallelamente alla costa e rappresentativi di piattaforme terrigeno-carbonatiche di mare temperato. il clima a cui è soggetto il golfo di cagliari, come noto, è mediterraneo caldo (sub-tropicale), poco piovoso (inferiore a 500 mm/a; pinna 1971; raimondi et al, 1995). il regime delle maree è microtidalico con massimi di circa 40 cm, la salinità è di circa 37÷38‰, le temperature medie superficiali del mare oscillano tra i 13° invernali e i 24° estivi (metallo, 1971; mosetti, 1977). 2. dati un nuovo rilevamento ecografico, eseguito tra il 2002 e il 2003, ha permesso la precisazione di elementi batimetrici e l’ubicazione di una nuova campionatura dei sedimenti (cossellu, 2003; pau, 2003). sono stati eseguiti 9 profili narrow-beam (200 khz), perpendicolarmente alla linea di costa fino alla profondità di circa 125 metri e spaziati da 2 a 4 km, e due profili multi-beam side scan sonar (reson seabat 81125) di comparazione (fig. 3). tali dati sono stati integrati con le linee sparker (500 j) ed ecografiche già disponibili e utilizzate in lecca et al. (1998). complessivamente sono state eseguite 77 campionature, di cui 33 lungo la battigia e 44 in piattaforma fino alla profondità di circa 50 m mediante benna van veen del volume di 2 dm3. queste ultime sono state effettuate lungo le linee ecografiche per fasce batimetriche: un campione alla profondità di 5 metri, tre campioni tra la fine del primo banco a posidonie e l’inizio del banco principale (dove questa suddivisione è presente), un campione all’interno del banco principale, un campione dopo il limite inferiore della prateria a circa –35 m ed un campione attorno ai –50 m. a causa della presenza continua della prateria a posidonie, non tutte le campionature hanno recuperato sedimento; al fine di evidenziare tale dato le campionature senza prelievo sono state indicate in chiaro nella carta di posizionamento (fig. 3). inoltre, sono stati analizzati 23 campioni prelevati nella parte distale della piattaforma (–50 ÷ –103 m), non inseriti nella tabella 1, che costituiscono parte di uno studio ancora in corso e attinente il dottorato di ricerca di uno degli autori (m. cossellu). la maggior parte delle operazioni sono state svolte a bordo di un’imbarcazione messa a disposizione fig.2 sistema deposizionale del golfo di cagliari: 1) depressioni della piattaforma interna; 2) prateria a posidonia; 3) fascia a sand waves; 4) paleo-linee di riva. depositional system of the gulf of cagliari: 1) troughs of the inner shelf; 2) posidonia meadows; 3) sand wave belt; 4) paleoshorelines. 204 dalla base logistico-operativa navale del corpo forestale e di vigilanza ambientale della regione sardegna. l'utilizzo di un'imbarcazione con ridotto pescaggio (0,5 m) ha consentito di eseguire i profili e le campionature a poca distanza dalla linea di costa, in fondali bassi fino a 1 metro circa. 3. zonazione delle facies ecografiche nelle registrazioni ecografiche sono state riconosciute la tipologia del fondo marino e alcune caratteristiche sedimentarie grazie alla struttura della riflessione e ai caratteri del segnale (figg. 4 e 5). la risposta ecografica risulta più o meno lunga a seconda che il segnale sia stato riflesso o diffratto da diversi tipi di fondale marino. in genere una risposta breve si associa a superfici deposizionali lateralmente continue prodotte da sedimenti sabbiosi con coda fine e regolare coefficiente di riflessione, mentre una risposta più lunga evidenzia superfici irregolari o materiali di maggior granulometria. le posidonie sono facilmente riconoscibili dai caratteristici gradini che evidenziano la presenza di mattes (sensu perez & picard, 1964), e canali o depressioni chiuse di inter e intra-matte. la prateria fitta e continua si riconosce per una morfologia ondulata non periodica e una maggior lunghezza della risposta ecografia rispetto alle aree in sedimentazione sabbiosa con fondali planari e ondulati. un tipico pattern ecografico indicativo della presenza di sand waves, conosciuto in altre piattaforme (allen, 1982; mccave & longhorne, 1982; fornos & ahr, 1997), è costituito da un’alternanza di risposta breve nella cresta e di una risposta lunga nel cavo delle ondulazioni (fig. 4f). fig.3 ubicazione delle nuove linee ecografiche, delle campionature e delle figure 4, 5, 7, 9 e 10. location of new echographic lines, sampling sites and figures 4, 5, 7, 9 and 10. l. lecca et al. 205 fig. 4 principali tipologie dei profili ecografici: a) shoreface sabbioso e inizio prateria interna; b) depressione della piattaforma interna; c) transizione al banco principale a posidonia; d) prateria a terrazzi; e) prateria diradata e transizione alla fascia a sand waves; f) sand waves; g) paleo linea di riva; h) bordo della piattaforma; i) depressione e banco principale a posidonia in profilo side-scan sonar. ubicazione in fig. 3. main ecographic patterns: a) sandy shoreface and beginning of inner posidonia meadows; b) inner shelf trough; c) transition to midshelf posidonia bank; d) terraced meadows; i) bank slope and transition to sand wave belt; f) sand waves; g) drowned shoreline; h) shelfbreak; i) trough and posidonia bank in side-scan sonar profile. for locations see fig.3. i sedimenti terrigeno carbonatici ... 206 dalle linee ecografiche può inoltre essere dedotta la posizione dei livelli idrodinamici critici relativi al moto ondoso, consentendo di riferire l’inizio delle prateria continua circa alla “base del moto ondoso di bel tempo” (fair weather wave base: fwwb) nella parte interna della piattaforma, e la transizione dalla fascia a sand waves ai fondali planari alla “base del moto ondoso di tempesta” (storm wave base: swb) in piattaforma intermedia. l’assenza in tutte le linee ecografiche di avvallamenti o incisioni localizzate e il prevalere di limiti zonali tendenzialmente paralleli alle isobate inducono a ritenere che l’idrodinamismo sia attribuibile in prevalenza al moto ondoso, rispetto a correnti di fondo di piattaforma. sulla base dell’intera copertura ecografica disponibile sono stati riconosciuti i caratteri morfologicodeposizionali dei principali ambienti della piattaforma (fig. 6). 3.1 piattaforma interna shoreface lo shoreface superiore è caratterizzato da una superficie inclinata debolmente convessa, spoglia di vegetazione sottomarina, che si estende in prosecuzione delle spiagge fino alla profondità di circa 3÷8 m (fig. 4-a). lo shoreface inferiore è invece variamente colonizzato da posidonie e da altre fanerogame. tale unità è assente davanti alle falesie di p. zavorra e di c. s. elia e ai promontori della piattaforma del sarrabus. prateria interna da pochi metri di profondità si sviluppano cespugli isolati di posidonie seguiti da mattes generalmente basse, piccole depressioni chiuse e canali profondi 1÷2 m riempiti di sedimento. più esternamente, al di sotto di una profondità critica di attenuazione dell’azione erosiva del moto ondoso, variabile nelle diverse aree del golfo, la prateria interna è invece più continua (fig. 5). nelle parti più profonde della depressione, davanti allo shoreface di s. gilla, il fondale passa gradualmente a superfici spoglie. depressioni della piattaforma interna due peculiari depressioni, disposte circa parallelamente alla linea di costa, sono presenti nella parte più interna della piattaforma a ne e a sw del capo s. elia, profonde rispettivamente 22 e 27 m (profilo t4, fig.5-a e profilo t7, fig. 5-b). tali depressioni risultano protette dalle tempeste dei quadranti meridionali grazie alla presenza del banco a posidonie della media piattaforma. il fondo della depressione del settore occidentale è spoglio e perfettamente planare, e viene pertanto associato a una sedimentazione fangosa; diversamente in quella orientale anche il fondo è colonizzato da fanerogame. 3.2 piattaforma intermedia banco principale a posidonie la culminazione della piattaforma intermedia è sede del banco principale a posidonie, che verso il largo prosegue con un debole pendio esterno. verso terra il banco è limitato da un netto pendio di transizione alle depressioni (figg. 4c e 5). all’interno del banco possono essere individuate diverse tipologie della fi g. 5 s ez io ni e co gr af ic he in te rp re ta te d ei p ro fil i t 4 (a ) ( s p ia gg ia d el p oe tt o) e t 6 (b ) ( s p ia gg ia d el la p la ya ). fw w b : b as e d el m ot o on d os o d i b el t em p o; s w b : b as e d el m ot o on d os o d i t em p es ta . s ca la o riz zo nt al e d el p ro fil o b d op p ia r is p et to a q ue llo a . u b ic az io ne in f ig . 3 . in te rp re te d e ch og ra p hi c se ct io ns o f t he p ro fil es t 4 (a ) ( af or e p oe tt o b ea ch ) a nd t 6 (b ) ( af or e p la ya b ea ch ). fw w b : f ai r w ea th er w av e b as e; s w b : s to rm w av e b as e. h or iz on ta l s ca le o f t he p ro file b d ou b le d in c om p ar is on t o th at o f a . f or lo ca tio ns s ee f ig .3 . l. lecca et al. distribuzione areale delle posidonie. la prateria a mattes alte 3÷4 m, con relativi canali e depressioni, occupa la parte alta e prossimale del banco, da circa –10÷15 m fino a circa –25 m presentando, probabilmente in relazione con l’idrodinamismo del moto ondoso, una tipica geometria terrazzata con ampi ripiani e gradini rivolti verso il largo (fig. 4d). analogamente alla prateria interna delle depressioni, la struttura appare distalmente più continua e omogenea, evidentemente per diminuzione dell’energia idrodinamica. la prateria prevalentemente continua occupa un’areale compreso tra i –20÷25, fino circa –30 m che costituisce il limite inferiore attribuibile al fattore luminosità (fig. 4e). sand waves lungo il pendio esterno la prateria passa a un fondale a morfologia ondulata interpretata come onde di sabbia (fig. 4f). le strutture, che hanno inizialmente una lunghezza d’onda di circa 200 m e un’altezza di 3 m circa, aumentano in frequenza e assumono dimensioni minori procedendo verso il largo. le waves sono asimmetriche con i lee sides rivolti verso terra indicando una direzione del trasporto associabile principalmente alla base delle onde di tempesta provenienti da se (istituto idrografico della marina, 1980). il limite inferiore si individua a una profondità di 50÷55 metri e viene messo in relazione con la profondità massima di azione delle onde di tempesta. fondali piani esternamente alla fascia a sand waves si instaurano fondali a morfologia piana che indicano una ulteriore diminuzione dell’idrodinamismo. tale fascia è limitata verso l’esterno dall’affioramento di diverse paleo-forme litorali, tra i –50 e i –60 m circa, relative a livelli di basso eustatico del pleistocene superiore. la maggiore di queste strutture (fig. 4h) si presenta allungata sw-ne e in rilievo di circa 4-5 m, e nella parte nord-orientale mostra talvolta due culminazioni con andamento subparallelo ricoperte da pinnacoli algali sub attuali. 207 fig.6 zonazione degli ambienti deposizionali sulla base dell’analisi dei profili ecografici. sedimentary framework of the gulf of cagliari, based on the analysis of the echographic profiles: 1) shoreface; 2) discontinuous inner posidonia meadows; 3) continuous inner posidonia meadows; 4) inner shelf trough; 5) mid-shelf posidonia bank; 6) fore slope depleted posidonia; 7) sand wave belt; 8) plane bottoms; 9) drowned shorelines; 10) bioherms on paleo-shores; 11) shelfbreak. i sedimenti terrigeno carbonatici ... 3.3 piattaforma esterna: all’esterno delle paleo-forme, il fondo marino mostra inizialmente un ridotto versante ricoperto da un accrescimento sigmoide fangoso olocenico (–60÷80 m circa), seguito da una fascia a debole pendenza che termina con un bordo a circa –125 a sedimentazione progradante inclinata (fig. 4h). la rottura di pendio della stretta piattaforma esterna nella parte nord-orientale avviene a circa –90 m per attività erosionale retrograda del canyon s. elia-foxi, mentre nella piattaforma del sarrabus (fig. 3 transetto t1) è individuabile a –70 m per controllo strutturale. 4. analisi dei sedimenti 4.1 granulometrie seguendo le consuete metodologie dell’analisi granulometrica, i campioni sono stati suddivisi in 7 classi con intervalli interi di unità φ tra 4000 e 63µm. per ogni campione è stata realizzata la curva di frequenza, utilizzata nella valutazione percentuale delle varie tipologie di granuli, e la curva cumulativa mediante la quale è stato calcolato il coefficiente di cernita (σφ = (φ 84 φ16 )/2, inman, 1952; tab. 1). 4.2 composizione per motivi di celerità è stato adottato un metodo semi-quantitativo, eseguendo il riconoscimento delle diverse componenti al microscopio binoculare e valutando contestualmente le percentuali areali mediante comparatori per stima visiva (bacelle & bosellini, 1965; swanson, 1985). data la varietà delle componenti e la taratura dei comparatori ogni 5÷10 %, i risultati ottenuti sono soggetti a errori dell’ordine del ±10% della singola componente. le varie famiglie di granuli sono state distinte sulla base dei caratteri morfologici, del colore e del comportamento all’attacco hcl diluito. allo scopo di valutare l’importanza delle diverse componenti, le stime areali sono state moltiplicate per il peso di ciascuna frazione e infine normalizzati sul campione totale. pertanto il significato del valore percentuale così ottenuto non è più strettamente ponderale, bensì ponderale-areale. il metodo inoltre, non tenendo conto delle differenze di peso di volume, per esempio tra bioclasti e clasti terrigeni, contiene ulteriori errori nelle valutazioni ponderaliareali. poiché i vari bioclasti hanno diverse porosità intragranulare e conseguentemente diverso peso di volume, tali errori non possono essere corretti tramite l’introduzione di un unico coefficiente. al fine di valutare l’ordine dell’errore, su cinque campioni sono state eseguite le calcimetrie (misura della co2 sviluppata su attacco con hcl) che hanno evidenziato una sopravvalutazione complessiva del carbonato bioclastico e delle frazioni fangose nelle stime ponderali-areali rispetto a quelle rigorosamente ponderali, intorno al 10%÷15%. questi errori, superabili nel prosieguo della ricerca con più precise metodologie, non pregiudicano tuttavia il significato deposizionale dei risultati, consentendo la suddivisione dei sedimenti campionati in tre principali gruppi di facies: silicoclastiche, miste e bioclastiche. componente terrigena sono state distinte le seguenti componenti terrigene: quarzo, feldspati s.l., miche s.l., litoclasti metamorfici e magmatici, litoclasti calcarei, minerali accessori e granuli antropici. in generale il criterio di riconoscimento per il quarzo è basato sul suo aspetto vitreo; il feldspato s.l., spesso riconoscibile sulla base della forma, raramente idiomorfa, della presenza di sfaldature e del colore; il k-feldspato è distinguibile per il tipico colore più o meno roseo e i plagioclasi per il colore biancastro. tali criteri qualitativi in certi casi possono aver portato alla confusione di specie mineralogiche, ma è certamente affidabile per la distinzione dei feldspati s.l. rispetto al quarzo e per il riconoscimento del litico in base all’evidenza della morfostruttura, del colore e della polimineralogia. in ogni caso queste imprecisioni nel riconoscimento dei granuli non influiscono sulla finalità dello studio, che è maggiormente rivolto alla valutazione dei rapporti tra la totale componente terrigena e quella carbonatico-bioclastica. componente bioclastica la componente bioclastica, facilmente distinguibile in base alla struttura scheletrica confrontata con la fauna descritta nel mediterraneo e nella piattaforma sarda (d’angelo & gargiullo, 1978; riedl, 1991; boudoresque et al., 1992 cum. bibl.), risulta costituita dai seguenti organismi: molluschi (bivalvi e gasteropodi in frammenti e gusci interi), talli di alghe rosse, colonie di briozoi, foraminiferi (soprattutto forme bentoniche), echinodermi (frammenti di gusci e radioli), ostracodi (presenti nelle frazioni 500÷125 µm) e numerosi organismi a guscio chitinoso-proteico appartenenti principalmente agli artropodi. inoltre si segnala la presenza di fecal pellets in alcuni campioni della depressione interna occidentale. in questa piattaforma, come in tutto i l mediterraneo, gran parte della produzione bioclastica deve essere associata all’ecosistema della posidonia (posidonia oceanica, l., deli le) che assieme a cymodocea nodosa (ucria, ascherson), zostera noltii (hornemann) e zostera marina (l.), esercita un controllo ecologico dominante e ha importanti relazioni di feedback con l’intero sistema biologico e sedimentario (unesco, 1977). nell’ambito dell’intera piattaforma, che per l’importanza della componente organogena è da considerarsi come carbonatica cold temperate-transitional (zona b zona c sensu carannante et al., 1988), emerge che i produttori più significativi sono le alghe rosse. tra queste possono essere distinte le alghe calcificate, dirette produttrici di bioclasti, dalle specie non calcificate dove la deposizione di carbonato si verifica solo nella parte sciafila per opera di organismi epifiti. il gruppo più produttivo è quello delle corallinacee, come noto proviste di tallo (hypothallium e perithallium) calcificato (adey & macintyre, 1973; riedl, 1991). la distinzione speditiva tra i generi e le specie è stata eseguita mediante il confronto con le forme descritte in letteratura (johnson, 1962; johnson & adey, 1965; boudoresque et al., 1992) che possono essere variamente ramificate (lithophyllum racemus, lithothamnium fruticulosum), incrostanti o a struttura a foglia (per esempio lithophyllum expansum, pseudolithophyllum expansum e mesophyllum lichenoides). tra le varie forme sembrano prevalere quelle a ramificazioni distanziate (loose branching, cfr. lithothamnium solutum, johnson, 1962) non fissate sul fondo rispetto alle forme incrostanti e a 208 l. lecca et al. 209 tab. 1 granulometrie, cernita e composizione dei campioni analizzati. nei totali con asterisco non è compresa la componente organica. arrotondamenti all’unita percentuale. grain sizes, sorting and compositions of the analized samples. values with asterisk lack the organic component. approximation to the whole number. campione prof. classi % peso unita φ σφ componente terrigena comp. (m) < -1 -1 ÷ 0 0 ÷ 1 1 ÷ 2 2 ÷ 3 3 ÷ 4 > 4 quarzo feldsp. minori litoc. totale bioc. rc1 50% 31% 9% 9% 0% 0% 0% 0,80 53% 43% 0% 4% 100% 0% rc2 25% 66% 9% 0% 0% 0% 0% 0,55 49% 47% 0% 3% 100% 0% rc3 38% 50% 11% 0% 0% 0% 0% 0,60 53% 40% 0% 7% 100% 0% rc4 38% 44% 6% 4% 7% 0% 0% 0,70 46% 44% 0% 5% 96% 4% rc5 0% 3% 22% 60% 14% 0% 0% 0,65 53% 33% 2% 4% 92% 8% rc6 0% 0% 6% 59% 34% 0% 0% 0,60 56% 32% 3% 3% 91% 9% rc7 0% 0% 0% 2% 85% 12% 0% 0,35 64% 21% 6% 1% 93% 7% rc8 23% 49% 5% 7% 15% 1% 0% 1,55 48% 42% 1% 6% 98% 2% rc9 5% 40% 30% 18% 7% 0% 0% 1,05 53% 39% 0% 7% 99% 1% rc10 2% 31% 42% 21% 4% 0% 0% 0,90 51% 39% 0% 10% 100% 0% rc11 17% 60% 16% 5% 1% 0% 0% 0,60 46% 42% 0% 12% 100% 0% rc12 19% 68% 6% 3% 5% 1% 0% 0,50 50% 39% 0% 10% 100% 0% rc13 3% 58% 35% 3% 1% 0% 0% 0,70 50% 42% 0% 8% 100% 0% rc14 26% 30% 9% 7% 23% 4% 0% 1,85 39% 31% 1% 25% 96% 4% rc15 23% 28% 10% 8% 26% 4% 0% 1,85 40% 34% 1% 22% 97% 3% rc16 3% 13% 55% 27% 1% 0% 0% 0,65 50% 39% 0% 11% 100% 0% rc17 1% 3% 3% 24% 68% 1% 0% 0,55 57% 33% 2% 3% 95% 5% rc18 0% 1% 36% 61% 2% 0% 0% 0,60 55% 36% 0% 9% 100% 0% rc19 0% 3% 8% 25% 61% 2% 0% 0,70 62% 30% 1% 5% 99% 1% rc20 1% 5% 3% 8% 82% 2% 0% 0,40 62% 32% 3% 3% 100% 0% rc21 3% 4% 7% 64% 22% 0% 0% 0,60 50% 28% 0% 20% 98% 2% rc22 0% 0% 0% 21% 77% 2% 0% 0,45 53% 35% 1% 4% 93% 7% rc23 0% 0% 4% 18% 61% 17% 0% 0,60 59% 28% 3% 4% 92% 8% rc24 0% 1% 3% 30% 56% 8% 0% 0,65 64% 30% 2% 3% 98% 2% rc25 0% 0% 5% 56% 39% 0% 0% 0,60 61% 29% 0% 7% 98% 2% rc26 1% 2% 6% 18% 72% 1% 0% 0,55 53% 16% 2% 2% 73% 27% rc27 1% 5% 67% 22% 6% 0% 0% 0,60 13% 7% 0% 3% 29% 77% rc28 5% 8% 33% 27% 25% 2% 0% 1,15 19% 7% 0% 2% 29% 71% rc29 6% 20% 60% 10% 3% 0% 0% 0,65 12% 5% 1% 80% 99% 1% rc30 0% 4% 35% 33% 27% 1% 0% 1,00 44% 33% 1% 9% 87% 13% rc31 1% 0% 0% 2% 81% 15% 0% 0,40 50% 28% 5% 2% 85% 15% rc32 15% 34% 35% 9% 6% 0% 0% 1,00 39% 49% 1% 3% 92% 8% rc33 43% 37% 20% 0% 0% 0% 0% 0,75 1% 0% 0% 85% 86% 14% t1c1 7,0 0% 0% 1% 28% 65% 4% 0% 0,60 55% 38% 4% 2% 100% 0% t1c2 10,0 0% 3% 56% 40% 0% 0% 0% 0,60 56% 39% 1% 4% 100% 0% t1c3 40,0 8% 42% 33% 13% 3% 1% 0% 0,90 1% 1% 0% 0% 3% 97% t2c1 3,5 0% 0% 1% 6% 57% 33% 3% 0,65 64% 28% 3% 3% 98% 2% t2c2 5,5 1% 1% 1% 6% 58% 26% 7% 0,60 67% 21% 4% 2% 94% 6% t2c5 39,2 13% 42% 34% 9% 1% 0% 0% 0,85 1% 1% 0% 0% 3% 97% t2c6 50,5 14% 33% 34% 13% 5% 1% 0% 1,05 1% 1% 0% 0% 2% 98% t3c1 1,0 0% 0% 4% 48% 41% 7% 0% 0,70 70% 27% 1% 2% 99% 1% t3c2 14,2 35% 56% 8% 0% 0% 0% 0% 0,55 44% 19% 0% 36% 99% 1% t3c3 21,8 25% 31% 20% 12% 8% 4% 1% 1,40 2% 1% 0% 1% 4% 96% t3c4 33,0 3% 9% 18% 30% 22% 15% 3% 1,40 18% 9% 1% 3% 31% 69% t3c5 52,4 13% 20% 20% 20% 19% 8% 1% 1,70 0% 0% 0% 0% 0% 100% t4c1 6,0 0% 0% 0% 1% 40% 56% 3% 0,65 67% 27% 2% 1% 97% 3% t4c5 35,0 9% 33% 35% 16% 5% 2% 0% 1,05 15% 11% 0% 4% 30% 70% t4c6 51,0 5% 16% 43% 28% 7% 2% 0% 0,95 18% 7% 0% 2% 27% 73% t5c1 1,6 0% 0% 1% 31% 50% 15% 3% 0,70 36% 0% 51% 0% 87% 13% t5c2 4,3 0% 0% 3% 88% 8% 0% 0% 0,35 45% 5% 43% 0% 93% 7% t5c4 33,5 4% 13% 23% 31% 24% 5% 0% 1,30 32% 8% 0% 3% 43% 57% t5c5 48,3 19% 46% 25% 8% 2% 1% 0% 0,90 0% 0% 0% 0% 0% 100% t6c1 2 0% 0% 0% 0% 69% 29% 1% 0,50 51% 13% 2% 3% 69% 31% t6c2 4 0% 0% 0% 1% 17% 55% 27% 0,70 39% 29% 1% 3% 72% 28% t6c3 8 30% 16% 16% 16% 13% 7% 1% 1,85 12% 3% 0% 0% 15% * 79% t6c5 12,5 25% 20% 15% 0% 31% 7% 2% 2,00 17% 5% 0% 2% 26% 74% t6c6 23,2 0% 0% 0% 0% 0% 0% 100% 0,30 20% 10% 0% 5% 35% * 30% t6c7 29 3% 18% 19% 23% 25% 9% 2% 1,50 18% 13% 0% 11% 43% 57% t6c8 50,1 14% 48% 27% 7% 3% 2% 0% 0,90 3% 0% 0% 0% 3% 97% t7c1 2,1 0% 0% 0% 0% 35% 60% 4% 0,65 62% 6% 6% 3% 77% 23% t7c2 5,3 0% 0% 0% 0% 3% 69% 27% 0,55 61% 7% 3% 3% 75% * 9% t7c3 11,9 68% 10% 6% 5% 4% 5% 2% 1,20 4% 2% 0% 1% 7% * 86% t7c4 17 12% 7% 11% 46% 20% 4% 1% 1,35 30% 11% 0% 4% 45% * 31% t7c5 24,4 0% 0% 0% 19% 61% 16% 4% 0,60 34% 10% 2% 21% 67% * 29% t7c7 36,6 22% 43% 20% 9% 4% 2% 1% 1,00 30% 9% 0% 17% 56% 44% t7c8 50,7 10% 32% 29% 17% 9% 3% 0% 1,25 0% 0% 0% 0% 0% 100% t8c1 1 2% 4% 8% 25% 50% 10% 1% 0,85 34% 21% 0% 0% 66% 44% t8c2 10,5 1% 4% 6% 10% 9% 22% 48% 1,55 48% 23% 2% 3% 76% 24% t8c3 15 0% 0% 0% 0% 9% 30% 60% 0,70 41% 20% 5% 6% 71% 29% t8c4 23 0% 0% 0% 0% 0% 0% 100% 0,30 20% 10% 0% 5% 35% * 30% t8c5 25 5% 10% 22% 31% 27% 4% 0% 1,25 32% 19% 0% 4% 55% * 37% t8c6 32 7% 31% 27% 16% 15% 4% 1% 1,45 26% 22% 0% 18% 66% 33% t8c7 50 12% 40% 28% 11% 6% 3% 1% 1,10 2% 0% 0% 0% 2% 98% t9c1 1,9 20% 29% 34% 15% 1% 0% 0% 1,05 3% 6% 0% 28% 38% 62% t9c2 6,5 32% 46% 15% 8% 0% 0% 0% 0,80 4% 6% 0% 43% 53% 47% t9c5 37 7% 38% 43% 7% 3% 2% 1% 0,85 38% 17% 0% 13% 68% 32% t9c6 51 5% 36% 38% 14% 5% 1% 0% 0,95 2% 1% 0% 0% 3% 97% c a m p io n i i n b a tt ig ia c a m p io n i i n p ia tt a fo r m a i sedimenti terrigeno carbonatici ... quelle globose. tra le specie debolmente calcificate si osserva peyssonnelia squamaria (gruppo delle peyssonneliaceae, cui fanno parte organismi a diversi gradi di calcificazione), che presenta una consistenza fogliacea. tra le forme non calcificate infine troviamo frequentemente la specie vidalia volubilis, in quantità volumetricamente rilevante nei sedimenti mobili della piattaforma intermedia, oltre il limite della posidonia. generalmente nelle frazioni granulometriche superiori a 0,5 mm si rinvengono frammenti e gusci interi di numerose specie di bivalvi e di gasteropodi. la componente bioclastica attribuibile ai molluschi, pur non costituendo elevate percentuali nei singoli campioni, riveste una notevole importanza data la sua distribuzione in tutta la piattaforma. anche i foraminiferi fanno parte dei più importanti gruppi di organismi che contribuiscono alla produzione dei sedimenti carbonatici, in particolare nelle componenti sabbiose medio-fini della piattaforma intermedia ed esterna. sono presenti soprattutto le forme bentoniche tra le quali è facilmente riconoscibile la miniacina miniacea, che forma sulle posidonie colonie irregolarmente ramificate simili a quelle dei briozoi e dal tipico colore rosso, e diverse specie di miliolidae anch’esse molto frequenti. le textulariidae, talvolta molto abbondanti, sono riconoscibili per il tipico guscio agglutinato biseriale. nei sedimenti delle parti distali aumentano progressivamente i foraminiferi planctonici. un altro importante gruppo di organismi biocostruttori è costituito dai briozoi, le cui colonie ricoprono diversi tipi di substrato e di organismi tra i quali le varie parti delle piante di posidonia. nei sedimenti si riconoscono facilmente le colonie a struttura reticolata (cellopora pumicosa, sertella septentrionalis, schizobranchiella sanguinea), da quelle a struttura radiale come la lichenopora radiata, e frammenti di specie ramificate (myapora truncata). gli echinodermi, regularia e irregularia, sono presenti in diversi vagli granulometrici come frammenti di gusci e, nelle frazioni più fini, radioli degli irregolari. l’aspetto e le dimensioni dei bioclasti permettono di distinguere tra i regularia prevalentemente i l paracentrotus lividus e tra gli irregularia l’echinocyamus pusillus spesso in associazione con alghe rosse e briozoi, lo schizaster canaliferus, abbondante nei substrati fangosi a diverse profondità, e lo spatangus purpureus. altre componenti sono rappresentate in genere nelle granulometrie comprese tra 125 e 500 µm da ostracodi, in percentuali nettamente subordinate rispetto al volume totale dei carbonati, e da piccoli organismi a guscio chitinoso-proteico. data la complessità dell’ecositema, questo elenco comprende solo i più importanti gruppi di bioclasti riconosciuti nei campioni senza escludere la presenza di altri organismi biocostruttori identificabili in altre parti della piattaforma e/o riconoscibili in uno studio specialistico. 5. facies deposizionali comparando le facies ecografiche con i risultati delle analisi dimensionali e composizionali dei sedimenti campionati si è giunti alla individuazione di 8 gruppi di litofacies, rappresentative dell’associazione di facies deposizionali dell’attuale piattaforma del golfo di cagliari (tab. 2; figg. 7 e 8). 5.1 facies silicoclastiche prossimali in questo gruppo vengono comprese le facies di foreshore e di shoreface superiore, cioè dalla battigia all’inizio delle posidonie, presenti nel golfo di quartu e nella sua prosecuzione fino alla piattaforma del sarrabus. dal punto di vista granulometrico i sedimenti hanno generalmente una moda compresa negli intervalli delle ghiaie (granule), delle sabbie molto grosse (fig. 7a) e delle sabbie grosse che nelle spiagge più protette, o per selezione eolica, possono arrivare alle sabbie fini-molto fini. la composizione del sedimento è quasi esclusivamente terrigena (quarzoso-arcosica). la componente bioclastica si limita a frammenti di molluschi perché il moto ondoso domina ostacolando la vita degli organismi, mentre la scarsa componente fine viene allontanata verso settori più distali. i campioni prelevati lungo la costa orientale hanno una composizione mineralogica che deriva direttamente dal substrato granitoide ampiamente affiorante nell’horst del sarrabus. nella spiaggia del golfo quartu i sedimenti, che mostrano maggiori indici di maturità tessiturale e composizionale, provengono invece dalle arenarie e marne arenacee mioceniche che affiorano a est di cagliari, quindi derivano anch’essi dal basamento metamorfico e granitoide del sarrabus, ma tramite più cicli deposizionali che possono risalire f ino al paleogene. le composizioni presentano un’alta percentuale in quarzo, generalmente superiore al 45%, una percentuale associata di feldspati e una componente litica nelle code ghiaiose. si associa inoltre una modesta quantità di biotiti e di altri minerali accessori. alcune eccezioni sono rappresentate dalle sabbie fini, campionate in località torre delle stelle (rc7 e rc8), ad abbondanti miche e minerali femici derivati probabilmente da locali affioramenti di rocce basiche, oltre a una componente bioclastica fino a circa il 10% di alcuni campioni. il limite batimetrico inferiore attribuito a questo gruppo di facies è individuato, nelle registrazioni ecografiche, dalla presenza continua delle posidonie che segna l’inizio della sedimentazione bioclastica. 5.2 facies quarzoso-bioclastiche dello shoreface di s. gilla nel foreshore-shoreface del settore occidentale del golfo sono presenti sabbie quarzose fini e molto fini, indici di un ambiente di spiaggia a bassa energia. infatti, questa parte del golfo, oltre a essere protetta dal contorno della costa, si avvale dell’attenuazione delle tempeste dei quadranti meridionali operata dal banco della media piattaforma. grazie a tale bassa energia, a pochi metri di profondità lo shoreface è stabilizzato da una prateria di basse fanerogame (cimodocea nodosa, posidonia oceanica) e alghe verdi (caulerpa prolifera, codium fragile e codium bursa) che precede internamente la prima fascia a posidonie. la composizione dei sedimenti è prevalentemente terrigena con circa il 50% di quarzo che proviene dagli apporti fluviali del graben del campidano, mentre la componente bioclastica si 210 l. lecca et al. 211 g r u p p i d i f a c ie s a m b ie n te e p r o c e s s i d o m in a n ti g r a n u lo m e tr ia c o m p o s iz io n e ( ve d i t ab . 1 ) s il ic o c la s ti c h e p r o s s im a li (q u a r z o s o fe ld s p a ti c h e ) 014 m q u a r z o s o b io c la s ti c h e d i s .g il la 06 m li ti c o b io c la s ti c h e d i p u n ta z a v o r r a 06, 5 m c a lc li ti ti c h e d i c a p o s .e li a 05 m fa n g o s e a la m e ll ib r a n c h i 827 m m is te b io c la s ti c o te r r ig e n e 15 -5 0 m a d a lg h e r o s s e e f o r a m in if e r i 50 -7 5 m d is ta li a la m e ll ib r a n c h i e f o r a m in if e r i 75 – 1 10 m depressione interna banco a posidonia piattaforma esterna pendio esterno fascia a sand waves paleo cordone (55-60 m) foreshore -shoreface s ab bi e gh ia io se m ol to g ro ss egr os se c he p as sa no a sa bb ie f in i-m ol to f in i n el la p ar te o cc id en ta le ( p oe tto p re r ip as ci m en to ). le g ra nu lo m et ri e m ag gi or i si ris co nt ra no i n ba tt ig ia e i n pr os si m ità d el la c os ta . i se d im en ti a te rr a so no d a b en e a d is cr et am en te cl as sa ti ( 0, 35 < σ φ < 0, 80 ) sa lv o ra re e cc ez io ni , i ca m pi on i i n m ar e so no d is cr et am en te c la ss at i. s ab bi e qu ar zo se f in i e m ol to f in i si d ep on go no i n co nd iz io ni d i m ot o on do so d i b as sa e ne rg ia . m od a co m pr es a tr a le s ab bi e fin i e m ol to fi ni (2 50 ÷6 3µ m ). le s ab bi e s on o da d is cr et am en te a m ed io cr em en te c la ss at e. s ab bi e gr os se o m ol to g ro ss e co n di sc re ta c om po ne nt e gh ia io sa . d a d is cr et am en te a m ed io cr em en te c la ss at e (0 ,7 5< σ φ< 1 ,0 5) s ed im en ti a m od a co m pr es a ne lle s ab bi e m ed ie e fin i da b en e a di sc re ta m en te c la ss at i (0 ,3 5< σ φ < 0, 70 ). c om po ne nt e si lic oc la st ic a do m in an te n eg li in te rv al li de lle c la ss i fin i e m ol to f in i. c om po ne nt e ca lc lit it ic a es p re ss a ne lle f ra zi o ni d el le s ab b ie m ed ie e fi ni . c ur ve g ra nu lo m et ric he a d an da m en to i rr eg ol ar e, i n al cu ni c as i m ar ca ta m en te b im od al i o p ol im od al i, co rr is p on d en ti a se d im en ti p oc o/ m ed io cr em en te cl as sa ti. i c am pi on i co m pl et am en te f an go si r is ul ta no c er ni ti (t 8c 4, t 6c 6) . l e fr az io ni a d ia m et ro m ag gi or e so no r ap pr es en ta te d a fr am m en ti di g us ci d i or ga ni sm i be nt on ic i. le f ra zi on i fin i so no q ua rz os e co n su bo rd in at a co m po ne nt e bi oc la st ic a. c ur ve g ra nu lo m et ric he a d as pe tt o irr eg ol ar e, ta lv ol ta b im od al i ( t6 c 7 e t8 c 6) . l a co m po ne nt e te rr ig ena r in ve nu ta n el le f ra zi o ni p iù g ro ss e è re lit ta . s ed im en ti ne l co m pl es so m ed io cr em en te o p oc o cl as sa ti (0 ,8 5< σ φ < 1, 50 ) co n ab bo nd an te s ilt c ar bo na tic o (n on è d a es cl ud er si u n le gg er o in cr em en to d i t al e fr az io ne d ov ut o a fr an tu m az io ne m ec ca ni ca in fa se d i s et ac ci at ur a) . le c la ss i pi ù ra pp re se nt at e so no q ue lle d el le s ab bi e gr os se e m ol to g ro ss e (d a 20 00 a 5 00 _ m ) b en ch é il se di m en to r is ul ti di st rib ui to in u n am pi o sp et tr o (tr a -1 φ e 2 φ ). p re se nz a di a bb on da nt e fr az io ne f in e ca rb on at ic a. c la ss at ur a m ed io cr e (0 ,9 0< σ φ < 1, 25 ). s ab bi e fin i e m ol to f in i co n di sc re ta c om po ne nt e fa ng os a. c la ss i gr an ul om et ric he m ag gi or i ra pp re se nt at e da p ic co le c on ch ig lie d i bi va lv i ch e da nn o lu og o a un s ed im en to , ne l co m pl es so m ed io cr em en te c la ss at o (0 ,7 5< σ φ < 1, 15 ). fa ci es s ili co cl as tic he s il ic o c la s ti c o : qu ar zo , fe ld sp at i ( da lla a lte ra zi on e de i g ra ni ti) , lit oc la st i d el b as am en to e rc in ic o. b io c la s ti c o : lim ita to a pi cc ol e co nc hi gl ie di g as te ro po di e a f ra m m en ti di g us ci d i bi va lv i. fa ci es m is te , s ili co cl as tic he e in s ub or di ne c ar bo na tic he s il ic o c la s ti c o : qu ar zo a s pi go li vi vi ( 50 % o p iù ), fe ld sp at i e lit oc la st i. b io c la s ti c o c irc a 15 -2 0% : m ol lu sc hi e in s ub or di ne : fo ra m in ife ri, ec hi ni di i rr eg ol ar i (r ad io li e fr am m en ti di gu sc i), b rio zo i, sp ic ol e di s pu gn e si lic ee . fa ci es m is te , l ito cl as tic obi oc la st ic he s il ic o c la s ti c o : l ito cl as ti an de si tic i, qu ar zo e f el ds pa ti a el ev at o g ra d o d i ar ro to nd am en to . b io c la s t ic o : p ic co li ga st er op od i; la m el lib ra nc hi ; c om po ne nt e su bo rd in at a: r ad io li e fr am m en ti di e ch in id i, fr am m en ti al ga li, b rio zo i, pi cc ol i c ro st ace i. fa ci es c al cl iti tic osi lic oc la st ic oca rb on at ic he c a lc li ti ti c o : c la st i d i c al ca ri m io ce ni ci s il ic o c la s ti c o : q ua rz o e fe ld sp at i. b io c la s t ic o : m o llu sc hi , fo ra m in ife ri b en to ni ci , b ri o zo i, ra di ol i d i e ch in id i. fa ci es m is te s ili co cl as tic oca rb on at ic he s il ic o c la s ti c o : q ua rz o a sp ig ol i v iv i e fe ld sp at i. b io c la s ti c o : b iv al vi e g as te ro po di . fr az io ne o rg an ic a: r es id ui d i p os id on ia i n co nc en tr az io ni im p or ta nt i ne lle f ra zi on i fin i. g ra nu li d i or ig in e an tr op ic a: sc ar ti da n av i a v ap or e e ra ri ag gr eg at i b itu m in os i. fa ci es m is te s ili co cl as tic oca rb on at ic he b io c la s ti c o : m ol lu sc hi (v ar ie s pe ci e di la m el lib ra nc hi e p ic co li ga st er op od i), b rio zo i, fo ra m in ife ri b en to ni ci e sv ar ia te sp ec ie d i o rg an is m i d el la b io ce no si a p os id on ia . s il ic o c la s ti c o : qu ar zo e f el ds pa ti in g ro ss i in di vi du i e ne lle f ra zi on i fin i, ar en ar ia c em en ta ta , fr am m en ti lit oc la st ic i de l ba sa m en to m et am or fic o. il te rr ig en o di m in ui sc e ne l pe nd io in fe rio re . fa ci es c ar bo na tic he . a ss oc ia zi on e fo rm at a da u na c om po ne nt e in di ge na c os tit ui ta in p re va le nz a da a lg he r os se c al ca re e, e d a co m po ne nt i p ro ve ni en ti da lla p ar te p iù e le va ta d el b an co a p os id on ia . b io c la s ti c o : a lg he r os se c al ca re e ra m ifi ca te e in cr os ta nt i, m ol lu sc hi , f or am in ife ri be nt on ic i, fr am m en ti di e ch in id i, br io zo i. p ic co le p er ce nt ua li di t er rig en o re lit to (c am pi on i t 6c 8, t 8c 7 e t9 c 6) n on ta le d a ca ra tt er iz za re d el le fa ci es m is te . fa ci es m is te .b io c la s ti c o : bi va lv i, fo ra m in ife ri pl an ct on ic i e be nt on ic i. s ub or di na ti: b rio zo i, fr am m en ti di g us ci e a cu le i di ec hi ni di ir re go la ri. s il ic o c la s ti c o : q ua rz o a sp ig ol i v iv i, m in er al i a cc es so ri c om po ne nt e au tig en a: g la uc on ite ( m od el li in te rn i di f or am in ife ri) . fo re sh or e e sh or ef ac e su pe rio re d el s et to re o rie nt al e de l g ol fo e sp os to a l m ot o on do so e a lle c or re nt i d a es so in do tt e ch e se le zi on an o e rim an eg gi an o i s ed im en ti. fo re sh or e e sh or ef ac e su pe rio re d el s et to re o cc id en ta le d el g ol fo p ro te tt o da lle m as si m e in te ns ità d el m ot o on do so . le c on di zi on i di s ca rs o id ro di na m is m o fa vo ris co no la p re se nz a di in fa un a e fa un a be nt on ic a ch e pr od uc on o un im po rta nt e vo lu m e di b io cl as ti. l a ba ss a in te ns ità d el m ot o on do so i nd uc e lim ita to tr as po rt o e sc ar sa s el ez io ne . b as e di f al es ie w av e do m in at ed . c op er tu re s ed im en ta rie d is co nt in ue s i d ep on go no s u fo nd al i r oc ci os i a lla b as e de lle f al es ie d el le a nd es iti o lig om io ce ni ch e di p .ta z av or ra s og ge tt e a fo rt e m ot o on do so ). i l s ub st ra to è c ol on iz za to ir re go la rm en te d a m at te s is ol at e di p os id on ia o ce an ic a; i se di m en ti si a cc um ul an o al l’i nt er no d i p ic co le d ep re ss io ni e ro si on al i.. o rg an is m i a gg lu tin an ti e in cr os ta nti ge ne ra no in cr os ta zi on i e a gg re ga ti di fr am m en ti lit ic i, ra di ol i e a ltr i b io cl as ti. b as e di fa le si e w av e do m in at ed . s ed im en ti di sc on tin ui d el fo re sh or e e sh or ef ace d el la p ic co la s pi ag gi a di c al a m os ca a lla b as e de lle f al es ie d el le c ol lin e ca lca re e di c ap o s . e lia , c ar at te riz za ti da lla p re se nz a di a bb on da nt i c la st i c al ca re i. le c on di zi on i i dr od in am ic he a ll’ in te rn o de lla b ai a so no p ro te tt e m en tr e al tr ov e l’e ne rg ia d el m ot o on do so è e le va ta . r ap id o de cr em en to d el la c om po ne nt e ca lc lit iti ca v er so il la rg o pe r l ’a zi on e sc he rm an te d el la p os id on ia . s ho re fa ce in fe rio re a nt is ta nt e la la gu na d i s . g ill a e de pr es si on e de lla p ia tt af or m a in te rn a. c ar at te riz za to d a al te rn an za d ep os iz io na le d i f an gh i d i b el t em po e la m in e sa bb io se d i te m pe st a. i s ed im en ti d el la d ep re ss io ne pr es en ta no u na la m in az io ne p ia no -p ar al le la c os tit ui ta d a un a fit ta a lte rn an za d i l am in e m ill im etr ic he d i s ab bi a m ol to f in e e liv el li ar gi llo si a d al to c on te nu to in m at er ia o rg an ica . f en om en i d i c os tip az io ne d el s ed im en to e fe rm en ta zi on e an ae ro bi ca . b as se e ne rg ie id ro di na m ic he p er p ro fo nd ità in fe rio ri al la b as e de l m ot o on do so di b el te m po e d i t em pe st a. b an co d i m ed ia p ia tt af or m a. f as ci a a pr od uz io ne c ar bo na tic a co n pr es en za d i se di m en ti te rr ig en i r el itt i e d i s ub or di na ti ap po rt i t er rig en i a tt ua li. t ra ns iz io ne tr a la p ra te ria a c an al i e qu el la c on tin ua c on tr ol la ta d al l’i dr od in am is m o de l m ot o on do so d i t em pe st a. c on tr ol lo d el la s ed im en ta zi on e da p ar te d ei fa tt or i b io lo gi ci : p ro du zi on e di s ed im en to c al ca re o e in tr ap po la m en to n ei r iz om i e ra di ci de lle p os id on ia d ei s ed im en ti ca lc ar ei e t er rig en i. i ca m pi on am en ti co n be nn a no n se m pr e so no p os si bi li pe r l ’in te gr ità d el la p ra te ria . p ia tt af or m a in te rm ed ia d is ta le e d es te rn a. a re al e si tu at o ol tr e il lim ite e st er no de lla p ra te ria , i n un a fa sc ia c he s i e st en de d al la b at im et ria in iz ia le d i c irc a 45 m . p ro du tt iv ità o rg an og en a lim ita ta a d ar ee n on s ta bi li e di sc on tin ue . r im an eg gi am en to o pe ra to d al m ot o on do so d i te m pe st a; a m bi en te i dr od in am ic o ne l co m pl es so a s ca rs a ca pa ci tà s el et tiv a (a bb on da nt e m at er ia le a g ra nu lo m et ria fin e) . e vi de nz e su i g ra nu li, d i e pi so di d i a lte rn i s ep pe lli m en ti e su cc es si ve m ob iliz za zi on i. s ul p al eo c or do ne s i s vi lu pp an o de i c al ca ri or ga no ge ni p re va le nt em en te a d al gh e ro ss e a co st itu ire lo ca lm en te d ei p in na co li. la f in e de lla c om po ne nt e al ga le e l a pr es en za d i se di m en ti pi ù fin i a m at ric e fa ng os a de lim ita v er so il la rg o la tr an si zi on e al la s uc ce ss iv a zo na d i f ac ie s. p ia tt af or m a es te rn a. f as ci a ba tim et ria a l d i s ot to d el la b as e de l m ot o on do so d i te m pe st a a de ca nt az io ne f an go sa . p ro du tt iv ità o rg an og en a ra pp re se nt at a da la m el lib ra nc hi , fo ra m in ife ri si a be nt on ic i ch e pl an ct on ic i ed e ch in id i irr eg ol ar i (m in or i). a lta c on ce nt ra zi on e di q ua rz o e m in er al i pe sa nt i ne lle f ra zi on i fin i. p re se nz a in ol tr e di m in er al i a ut ig en i. ta b . 2 s in te si d eg li am b ie nt i e d el le fa ci es d ep os iz io na li d el la p ia tt af or m a d i c ag lia ri. ke tc h of e nv iro nm en ts a nd d ep os iti on al fa ci es o n th e sh el f o f t he g ul f o f c ag lia ri. i sedimenti terrigeno carbonatici ... 212 attesta, nei campioni prelevati sulla battigia, intorno al 10÷15% e nei campioni di spiaggia sommersa al 30% circa del totale, fino a circa il 45% nel campione t8c1. i bioclasti sono in prevalenza gusci di molluschi (lamellibranchi e gasteropodi), talvolta sub-attuali calcitizzati e sepolti da sabbie siltose nerastre. si ritrovano inoltre radioli e frammenti di gusci di echinidi irregolari, briozoi, foraminiferi e, nelle frazioni di diametro minore, rare spicole di spugne silicee. sempre in relazione con la bassa energia, nei campioni più distali di tale gruppo di facies è spesso presente una componente organica costituita da frammenti di foglie di posidonia. tale componente nel campione t6c3 arriva fino a circa il 30% (stima areale al binoculare) nella frazione 500÷250 µm, nel t7c2 il al 30% nella frazione 250÷125 µm e nel t7c3 al 20% nelle frazioni 1000÷500 µm. 5.3 facies litico-bioclastiche di punta zavorra nei pressi di punta zavorra si osservano facies poligeniche con componente litoclastica e bioclastica. il fondo marino è in prevalenza roccioso (andesiti) e i sedimenti si accumulano all’interno di concavità erosionali che si alternano a mattes isolate di posidonia. i sedimenti sono rappresentati da sabbie grosse o molto grosse con una discreta componente ghiaiosa. nella battigia predomina la componente litoclastica (85%), mentre in mare predomina la componente bioclastica (50÷60% circa). i clasti litici, in genere arrossati, provengono dall’erosione delle andesiti oligoceniche e dei depositi quaternari esposti in falesia, e indirettamente dal basamento dell’horst del sulcis. nettamente subordinati sono i piccoli granuli di quarzo a spigoli vivi, che diventano relativamente importanti nelle frazioni a granulometria minore. la componente bioclastica è composta prevalentemente da piccoli gasteropodi, mentre i lamellibranchi sono meno rappresentati. inoltre sono presenti radioli e frammenti di gusci di echinidi e, in misura subordinata, frammenti algali, briozoi e chele di piccoli crostacei, oltre a incrostazioni e particelle aggregate per opera di vermi. 5.4 facies calclititiche di capo s. elia attorno al capo s. elia e soprattutto all’interno dell’insenatura di cala mosca è presente un gruppo di facies terrigene a componente calclititica. sulla battigia le sabbie sono grosse e composte prevalentemente da granuli calcarei poco elaborati, provenienti dall’erosione fig.7 principali litofacies: a) campione t3c2: sabbie ghiaiose silicoclastiche di shoreface; b) campione t4c6 misto bioclastico-terrigeno del pendio esterno del banco a posidonia; c) campione t3c5 in facies ad alghe rosse e foraminiferi; d) campione t7c5 misto alla transizione della depressione ovest col banco principale, frazione 250÷125µm: nel riquadro granuli fecali isolati. la barra di scala è lunga 5 mm in a, b, c e 1 mm in d. ubicazione in fig. 3. main lithofacies: a) sample t3c2: shoreface siliciclastic gravelly sands; 2) sample t4c6: bioclastic-terrigenous gravelly sand of the outer slope of the posidonia bank; 3) samplet3c5: red algae and foraminifers facies; 4) sample t7c5 in western trough, fraction 250÷125µm: in square selected fecal-pellets. bar scales are 5 mm in length for a, b, c and 1 mm for d. for locations see fig.3. l. lecca et al. 213 delle falesie dove affiora una sequenza del miocene superiore costituita da calcari a lithotamnium, assieme a calcari marnosi e in subordine areniti quarzoso-feldspatiche debolmente cementate (leone et al., 1992). questa componente litica subisce un rapido calo spostandosi verso il largo con l’instaurarsi dei banchi di posidonie, presenti già a poca distanza dalla riva. la componente terrigena è in parte quarzosa (fino al 45% in t5c2) con granuli di dimensioni minori rispetto a quelli calclititici. la componente bioclastica è decisamente subordinata in battigia (circa 1% del totale) ma acquista maggiore importanza a qualche metro di profondità (circa 10%). tale componente è costituita da molluschi (compresi vermetidi), briozoi, radioli di echinidi, foraminiferi bentonici e ostracodi. la materia organica, come frammenti di fanerogame ed alghe di bassa profondità, è talvolta presente in quantità importante. 5.5 facies fangose a lamellibranchi dello shoreface inferiore antistante s. gilla e della depressione della piattaforma interna la depressione interna, rispetto allo shoreface superiore e al banco principale della prateria a posidonie, è un ambiente a bassa energia dove si depongono in prevalenza sabbie fini e fanghi. le curve granulometriche hanno un andamento irregolare, in alcuni casi sono marcatamente bimodali o polimodali. questo carattere è dovuto alla presenza di gusci provenienti da infauna e fauna bentonica che colonizzano il fondale fangoso. inoltre nel campione t6c5 si trovano ciottoli fluviali relitti che documentano una sedimentazione tardo-olocenica-attuale discontinua che, in aree limitate, lascia esposti sedimenti più antichi. le sabbie fini e molto fini quarzose presentano una componente organica di frammenti di posidonia, oltre a gusci di lamellifig.8 zonazione delle facies deposizionali della piattaforma del golfo di cagliari. depositional facies on the shelf of the gulf of cagliari: 1 ) quartzose-bioclastic facies of s. gilla’s shoreface; 2) terrigenous facies of quartu’s shoreface and sarrabus’ shelf; 3) p.ta zavorra lithic-bioclastic facies; 4) cape s. elia calci-lithic arenite facies; 5) sandy-muddy bivalve bearing facies of the lower western shoreface; 6) muddy facies with bivalves of the western inner shelf’s trough; 7) mixed bioclastic-terrigenous facies of the eastern shelf’s trough; 8) middle-shelf mixed bioclastic-terrigenous facies; 9) red algae and foraminifers facies; 10) distal facies with bivalves and foraminifers; 11) paleo shore-line; 12) shelfbreak. i sedimenti terrigeno carbonatici ... branchi e a una componente bioclastica. l’importanza dei frammenti di posidonie, è stata quantificata per stima areale nei campioni t7c3 (30% nelle frazioni 2000÷250 µm), t7c4 (60% tra 2000÷1000 µm, 50% tra 1000÷500 µm e 30% tra 500÷250 µm), t7c5 (20% tra 500÷250 µm) e t6c5 (5% tra 250÷125 µm). in t7c4 si riscontrano rari pirosseni e biotiti attribuibili a una piccola componente andesitica proveniente da punta zavorra o altri affioramenti di andesiti (fig. 1). si ritrovano infine materiali di origine antropica, probabili scarti di combustione di navi a vapore che stazionavano in rada. questa zona del golfo di cagliari anche ai nostri giorni è infatti interessata da ancoraggi di navi commerciali. a tal proposito si segnala in questo gruppo di facies così come nello shoreface di s.gilla la presenza di rari granuli aggregati da bitume. le facies più fangose sono rappresentate dai campioni t6c6 e t8c4 nei quali tutto il materiale passa al vaglio dei 63 µm. questi fanghi danno una discreta effervescenza all’hcl per cui la parte carbonatica è stata valutata mediante calcimetria intorno al 20%. al microscopio è visibile, dopo un attacco con hcl, molta materia organica, particelle siltose di vario aspetto e una componente argillosa terrigena (argille e materiale organico = 43,0%). infatti questa zona del golfo è soggetta all’accumulo dei sedimenti più fini degli eventi di piena del rio mannu e del cixerri, le cui torbide si è constatato che raggiungono quasi tutta la parte occidentale della piattaforma. il materiale bioclastico è costituito per lo più da grossi lamellibranchi come mitilidi, pettinidi e cardidi e subordinati gasteropodi. la parte restante è costituita da foraminiferi, briozoi, radioli di echinidi, rari noduli algali e numerosi fecal pellets (fig. 7d). questi ultimi hanno dimensioni variabili tra 500÷125 µm e sono costituiti da fango terrigeno-carbonatico e materia organica. i sedimenti mostrano, al momento del prelievo (la benna ha campionato fino a circa 20 cm sotto la superficie del fondo), una tipica struttura costituita da una fitta alternanza di lamine millimetriche di sabbia molto fine e argille nere. inoltre la parte interna di alcuni bioclasti si presenta annerita a causa del seppellimento nel fango. questi elementi documentano che tale facies laminata è attribuibile all’alternanza di fanghi di bel tempo, ricchi di materia organica, con lamine sabbiose di tempesta, e che in questo ambiente si instaurano precocemente condizioni riducenti subito al di sotto dell’interfaccia acqua-sedimento. 5.6 facies miste bioclastico-terrigene sedimenti misti bioclastico-terrigeni sono presenti in piattaforma intermedia nel banco principale a posidonia e nel pendio esterno al banco. l’ambiente deposizionale di questo gruppo di facies corrisponde circa all’areale dell’offshore superiore (15÷50 m circa). i sedimenti sono mediocremente classati (fig. 7b), talvolta bimodali (t6c7 e t8c6), prevalentemente distribuiti nelle classi delle sabbie grosse e molto grosse (2000-500 µm), con una discreta coda fine. generalmente il bioclastico prevale sul terrigeno con percentuali del 60÷70%, ma talvolta è subordinato con valori del 30÷40%. la componente bioclastica è dominata dai molluschi, mentre nella parte distale assumono maggiore rilevanza i frammenti di alghe rosse. inoltre risulta importante la presenza di briozoi, tra i quali sono stati riconosciuti cellepora pumicosa e lichenopora radiata, e di numerosi foraminiferi bentonici di dimensioni fino a 1000 µm. è da notare la frequente presenza di miniacina miniacea, che vive sulle radici e rizomi esposti delle posidonie. in quantità subordinata si rinvengono radioli o frammenti di gusci di echinidi, alcuni piccoli crostacei e rari coralli aermatipici. la componente silicoclastica rinvenuta nella parte prossimale del banco è generalmente rappresentata da sabbie medie e fini, mentre nella parte esterna del banco e del pendio si rinvengono sabbie molto grosse debolmente ghiaiose costituite da quarzo, feldspati, litoclasti metamorfici e arenarie cementate, oltre a una subordinata coda fine quarzosa. l’origine di tale componente silicoclastica nella parte prossimale del banco (zone in cui il banco a posidonie si raccorda direttamente allo shoreface) può essere ricondotta alla attuale sedimentazione di sabbie di shoreface mobilizzate da eventi di tempesta. diversamente, nelle parti separate dalle depressioni, nel banco a posidonie e nel pendio fino a –50 m circa, la componente silicoclastica deve essere attribuita al rimaneggiamento e risedimentazione di sedimenti relitti presenti in questa parte di piattaforma. questi sedimenti, sulla base del grado di elaborazione e della presenza di granuli di arenarie cementate senza matrice possono essere attribuiti in parte a paleo spiagge, e in parte, per la presenza di granuli cementati da matrice arrossata, a paleo depositi continentali (probabilmente fluviali o colluviali). l’analisi dei diversi profili ecografici eseguiti mostra che il banco costituisce una struttura continua trasversale a tutto il golfo, pur presentando areali a diversa tipologia. purtroppo in questa zona spesso la benna non ha prelevato alcun sedimento a causa della continuità delle posidonie; pertanto per una migliore descrizione della sedimentazione relitta si rimanda successive campionature. 5.7 facies ad alghe rosse e foraminiferi queste facies compaiono nella parte più esterna del pendio del banco a posidonia, cioè lungo la fascia delle sand waves, e sui fondali pianeggianti fino alla transizione verso la piattaforma esterna (offshore superiore-offshore inferiore). il sedimento è costituito da una componente indigena ad alghe rosse e foraminiferi, e da sedimenti alloctoni provenienti dal pendio esterno del banco. la composizione è quasi esclusivamente bioclastica (fig. 7c) ma verso terra si osserva una transizione graduale con le facies miste. l’andamento delle curve granulometriche mostra una moderata uniformità tra tutti i campioni prelevati; gli intervalli più rappresentati sono quelli delle sabbie grosse e molto grosse (da 2000 a 500 µm), benché il sedimento risulti distribuito in un intervallo tra le ghiaie e i fanghi. l’importante presenza di una coda di sabbia molto fine fango carbonatico documenta l’ambiente distale a bassa energia. la componente predominante è costituita da grossi frammenti algali prevalentemente ramificati (lithophyllum racemus) e altre forme indeterminate loose branching (sensu johnson 1962 e johnson & adey, 1965) di pochi millimetri. seguono per importanza i foraminiferi, frammenti di molluschi, di echinidi e, in subordine, briozoi. la fauna bentonica si sviluppa probabilmente su zone in rilievo e in substrati semi stabili 214 l. lecca et al. dove le alghe rosse si rinvengono regolarmente vive e lasciano supporre un ampio areale di distribuzione. questo gruppo di litofacies si riscontra a cavallo della paleo-riva dei –55 m al di sopra della quale, talvolta nella parte orientale, le linee ecografiche evidenziano la presenza di pinnacoli algali. il limite batimetrico inferiore di queste facies è stato ubicato, indicativamente in base ai profili ecografici, lungo i fondali pianeggianti a sedimentazione fangosa della piattaforma esterna. tali facies, campionate maggiormente nella zona “a” di figura 3, saranno descritte con maggior dettaglio in successive fasi di questa ricerca. 5.8 facies distali a lamellibranchi e foraminiferi le campionature tuttora in corso nel settore occidentale del golfo hanno permesso di riconoscere, nella parte più esterna della piattaforma (–75÷–110 m), la transizione ad una fascia a sedimentazione sabbiosa fine e fangosa mista quarzoso-bioclastica. la produttività organogena è rappresentata da piccole conchiglie di bivalvi, foraminiferi sia bentonici che planctonici e in minor quantità da echinidi irregolari. la componente silicoclastica è rappresentata da sabbie fini quarzose a spigoli vivi. inoltre è presente una discreta concentrazione di minerali autigeni, accresciuti all’interno di foraminiferi, e altri minori indeterminabili. 6. modello deposizionale tardo olocenico–attuale della piattaforma di cagliari 6.1 ambienti e processi la piattaforma del golfo di cagliari si delinea come un sistema sedimentario complesso, sede di processi deposizionali controllati da diversi tipi di fattori sedimentologici. il regime idrodinamico è quello di uno shelf wave-dominated “attenuato”, essendo il golfo esposto alle sole mareggiate dai quadranti meridionali e ridossato rispetto a quelle dei quadranti occidentali (serra, 1971; istituto idrografico della marina, op. cit.), infatti le posidonie riescono a prevalere nella piattaforma intermedia, diversamente a quanto avviene nella sardegna occidentale dove le frequenti tempeste da nordovest danno luogo ad una piattaforma tipicamente wave-dominated (carboni et al., 1989). gli apporti terrigeni sono scarsi mentre, in piattaforma intermedia, una importante produttività carbonatica si sovrappone a sedimenti di precedenti cicli deposizionali a controllo eustatico. il risultato è quello di una piattaforma mista terrigeno-carbonatica organizzata in un sistema di ambienti documentati dalla presenza dei diversi gruppi di facies deposizionali (tab. 2 e fig. 9). ambiente transizionale le più complete sezioni della piattaforma mostrano una transizione all’ambiente estuarino costituita da una laguna microtidalica, schizoalina, separata dal dominio marino mediante la discontinua barriera sabbiosa attuale. questo ambiente, non descritto in questo studio, deve essere considerato integrante del sistema della piattaforma continentale per gli apporti terrigeni estuarini che alimentano lo shoreface, per i controlli marini che subisce attualmente da parte delle tempeste, per la produttività bioclastica salmastra (cottiglia 215 fi g. 9 a m b ie nt i e m od el lo d ep os iz io na le d el la p ia tt af or m a d i c ag lia ri. s ez io ne r ic os tr ui ta s ul la b as e d i u n p ro fil o sp ar ke r 50 0 j e d iv er se li ne e ec og ra fic he : i l p ro fil o m os tr a le s eq ue nz e d ep osi zi on al i p re ce d en ti l’u lti m o m in im o gl ac io -e us ta tic o d ei 1 8÷ 20 k a (g rig io c hi ar o) e la s eq ue nz a d i t ra sg re ss io ne e d i a lto e us ta tic o p os tgl ac ia le (g rig io s cu ro ). u b ic az io ne in f ig . 3 . e nv iro nm en ts a nd d ep os iti on al m od el o f th e sh el f of c ag lia ri. i nt er p re ta tiv e cr os sse ct io n of a 50 0 j sp ar ke r p ro fil e an d o f se ve ra l e co gr ap hi c lin es o f th e w es te rn s ec to r of t he g ul f. l ig ht gr ey : p re 1 8÷ 20 k a se d im en ts , d ar k gr ey : p os t 18 ÷ 20 k a se d im en ts . f or lo ca tio n se e fi g. 3. i sedimenti terrigeno carbonatici ... et al., 1973) e infine perché durante gli stazionamenti alti quaternari è stata sede dei più interni coastal onlap. rispetto all’attuale piattaforma tale ambiente viene pertanto considerato come un paleo shore-shorefacedepressione interna della piattaforma quaternaria durante le fasi di massimo eustatico come per esempio è stato durante il tirreniano (mis 5, marine isotope stage 5 sensu martinson et al., 1987; pecorini, 1986). shoreface superiore la sedimentazione in shoreface è generalmente fining basinward con sabbie grosse in prossimità della battigia, dove dominano le strutture a ripples da onda di bel tempo, e fini verso le depressioni della piattaforma interna. il profilo complessivo è quello di un corpo sabbioso ampio da qualche decina fino a diverse centinaia di metri, debolmente convesso. attualmente questo ambiente mostra condizioni instabili, anche se i bilanci volumetrici totali sono difficilmente valutabili; il foreshore, che costituisce l’elemento maggiormente osservabile, mostra in tempi storici arretramenti per cause globali e probabilmente anche per cause antropiche locali. la produttività carbonatica si evidenzia nella parte distale dei fondali sabbiosi e con l’inizio delle posidonie, che nelle linee ecografiche può essere ubicato a profondità di –4÷8 m nel settore orientale e a circa –2÷6 m in quello occidentale, dove gli organismi crescono in condizioni idrodinamiche generalmente tranquille. nel settore orientale del golfo (spiaggia del poetto pre-ripascimento, golfo di quartu), il dinamismo del moto ondoso ostacola lo sviluppo delle praterie interne nella zona prossimale dello shoreface (<–4 ÷ –8 m). la sedimentazione bioclastica è ridotta ai clasti più grossi, mentre i più fini e/o i meno pesanti vengono allontanati verso settori più distali, dando luogo a una sedimentazione quasi completamente silicoclastica. nel settore occidentale del golfo (spiaggia della maddalena la playa) le fanerogame colonizzano le aree prossimali più protette già a pochi metri di profondità, e le sabbie presentano un’importante componente bioclastica fino a circa il 40%. infatti, l’energia in questo tratto di costa è piuttosto bassa e il substrato di sabbie fini-molto fini permette la presenza di una ricca fauna epi ed endo-bentonica di limivori e filtratori. shoreface inferiore e prateria a posidonie interna come è già stato illustrato, i profili ecografici documentano una prima prateria a posidonia, con una fascia prossimale a mattes e canali intermatte e una più profonda dove la prateria si presenta continua. i sedimenti sono silicoclastici di shoreface nella parte interna e siltosi e bioclastici nella parte più profonda di transizione alla depressione della piattaforma interna. questa colonizzazione prossimale da parte della prateria è un prezioso indicatore delle condizioni idrodinamiche e consente di ubicare, anche se in modo approssimato, la base del moto ondoso di bel tempo (fwwb) all’inizio della fascia a posidonie “continue” (fig. 5). poiché lo sviluppo della struttura a matte richiede diversi anni si deduce che questo limite non è soggetto alle fluttuazioni stagionali, ma è piuttosto da ritenersi stabile lungo un arco di tempo almeno decennale; solo durante le maggiori tempeste viene modificato e le posidonie vengono spiaggiate. sulla base dell’analisi ecografica il fwwb è ubicabile lungo il profilo t4 (settore nord-orientale del golfo) alla profondità di 12÷13 m, e a circa 7÷8 m nel profilo t6 (settore occidentale, fig 7). depressioni della piattaforma interna la piattaforma di cagliari, rispetto al resto della piattaforma sarda, è caratterizzata dalla presenza di due depressioni che si sviluppano parallelamente alla linea di costa, ubicate tra lo shoreface e il banco della piattaforma intermedia. la più importante, quella a ovest di capo s. elia e antistante la laguna di s. gilla, è colonizzata dalla prateria solo tra lo shoreface e l’offshore superiore, mentre la parte più profonda è spoglia e planare. la sedimentazione varia da un’alternanza di lamine di fango e di sabbie fini (facies fangose a lamellibranchi), a sedimenti completamente fangosi nella parte più profonda (-27 m, profilo t7; campioni t6c6, t8c4). l’idrodinamismo è molto basso grazie alla protezione data dal banco della piattaforma intermedia che accresce delimitando una zona chiusa a scarsa circolazione delle acque dove episodicamente, sul fondo, s’instaurano condizioni anossiche. l’assenza della prateria in questa parte della depressione è probabilmente riconducibile agli effetti sfavorevoli indotti dalla sedimentazione fangosa asfittica sull’apparato radicale e dal materiale fine in sospensione derivato dalle torbide fluviali argillose e dal disfacimento delle foglie delle posidonie delle zone adiacenti. in questo ambiente si individua dunque un limitato “offshore inferiore” chiuso nella piattaforma interna protetta (fig. 9), come evidenziano i fondi piani e la laminazione parallela nella parte più profonda della depressione, mentre esternamente al banco, nella parte aperta ed esposta della piattaforma, l’inizio dell’offshore inferiore (swb) si delinea a maggiori profondità, tra le sand waves e i fondi piani. i campioni più fangosi mostrano una componente carbonatica con valori di circa il 20% (da calcimetria) che si associa a una quarzosa di circa il 60% e una componente organica di circa il 10-20%. oltre a queste componenti si sottolinea la presenza di fango in granuli fecali (fig. 7d). nella depressione della piattaforma a est di capo s. elia, invece, un simile contesto deposizionale non si verifica, essendo la depressione più piccola e meno profonda (–22 m, profilo t4). l’esposizione al moto ondoso consente sia un maggior ricambio d’acqua sia l’allontanamento delle frazioni fini, pertanto i sedimenti sono più sabbiosi e le posidonie sono presenti anche nella parte più profonda. banco principale a posidonie nel golfo di cagliari, le attuali condizioni favorevoli fanno sì che le posidonie e i sedimenti associati producano un rilievo riccamente carbonatico che, non avendo una struttura interna wave resistent, viene denominato banco sensu riding (2002). il banco a posidonia si eleva di 10÷15 metri rispetto alle depressioni interne, culmina a circa –12 metri e possiede un pendio esterno, anch’esso con una importante componente carbonatica, fino alla transizione con i fondi planari esterni a circa 50 metri. il suo sviluppo occupa un’ampia fascia quasi parallela alla linea di costa che si raccorda verso ne alla piattaforma del sarrabus e verso sw a quella del sulcis meridionale e nella parte centrale al promontorio di capo s. elia. i profili ecogra216 l. lecca et al. fici evidenziano che la zona di offshore superiore, coincidente con la parte alta del banco, è completamente colonizzata dalla posidonia, come dimostrano i numerosi tentativi di campionamento non riusciti in diverse parti del banco. la prateria, pur ricoprendo in maniera omogenea dei vasti areali, presenta discontinuità e differenze di accrescimento al suo interno. la struttura a matte con pareti alte e canali intra-matte è probabilmente prodotta dalla frequente azione delle onde di bel tempo e dall’azione più intensa di quelle di tempesta. più esternamente la prateria appare più continua e caratterizzata spesso da un profilo ad ampi gradini. nelle parti distali comincia a diradarsi per poi scomparire alla profondità di circa 30 ÷ 35 m per diminuzione della luminosità. al banco si associa un’importante produttività bioclastica che si diversifica in prossimità dell’apparato radicale, nei rizomi e nelle foglie. gli abbondanti resti scheletrici carbonatici vengono intrappolati dalla prateria e colmano locali depressioni di inter o intramatte. il ruolo della prateria nel controllo della sedimentazione attuale si esplica da un lato nella produzione di materiale organico e di sedimento carbonatico-bioclastico, dall’altro nelle funzioni di consolidamento delle superfici deposizionali, che impediscono la dispersione degli apporti terrigeni al largo, e di smorzamento del moto ondoso di tempesta e delle correnti associate. lo sviluppo verticale delle mattes è relazionato al tasso di sedimentazione e può raggiungere velocità di crescita dell’ordine di 1 m/secolo (pérès & picard, 1964; riedl, 1991). i profili sparker (lecca et al., 1998) ed sbp (fig. 10) effettuati trasversalmente al banco mostrano una capacità almeno debolmente aggradante. la facies deposizionale più diffusa è quella mista bioclastico-terrigena. la componente terrigena nella parte prossimale del banco può provenire da risospensioni per tempesta di sabbie fini, mentre distalmente deve essere attribuita al rimaneggiamento di sedimenti relitti. pendio esterno del banco, settore distale a fondo planare e paleo-riva il pendio esterno del banco principale, ormai spoglio di posidonie, presenta ondulazioni del fondo disposte circa parallelamente al banco, chiaramente riconoscibili come sand waves prodotte dall’azione delle onde di tempesta sul fondale, in una fascia batimetrica compresa tra –35 e –55 metri circa. il sedimento è costituito da sabbie bioclastiche molto grosse e mal classate con matrice fangosa, testimonianti un ambiente idrodinamico attuale episodicamente trattivo. la componente bioclastica è costituita da frammenti algali (prevalentemente alghe ramificate non fissate al fondo), da briozoi, molluschi, echinidi e foraminiferi. la frazione algale è costituita soprattutto da lithophyllum racemus, oltre a lithophyllum expansum, 217 fig. 10 interpretazione sequenziale dei sedimenti che colmano la depressione occidentale della piattaforma interna. a) interpretazione dei profili 3,5 khz (contu et al.,1983; lecca et al., 1998), b) unità genetiche, fasi eustatiche e sequenziali. ubicazione in fig. 3. interpretation of 3.5 khz profiles (contu et al.,1983; lecca et al., 1998) showing: a) the genetic units and b) the sequential and eustatic stages of the western trough infilling sediments. for location see fig.3. i sedimenti terrigeno carbonatici ... peysonnelya sqamaria e vidalia volubilis, quest’ultima parzialmente calcificata. i frammenti algali appaiono spesso di colore grigio scuro testimoniando episodi di seppellimento. la componente silicoclastica relitta è stata campionata tra –30 e –50 m con percentuali decrescenti verso il largo. nella parte terminale del pendio le litofacies tendono a perdere il carattere terrigeno fino a divenire completamente bioclastiche. tenuta presente l’evoluzione paleogeografica durante la risalita olocenica, questa componente deve essere ritenuta più ampiamente disponibile e ricondotta fino alla linea di costa verso il sulcis e il sarrabus, sia verso il capo sant’elia. i tipi di granuli individuati nei sedimenti campionati (clasti litici metamorfici, granuli millimetrici di quarzo e kfeldspato e rari granuli di arenarie debolmente cementate), sono attribuibili a diverse antiche facies verosimilmente presenti attualmente sotto il banco principale delle posidonie (tra i –10 e i –50 m circa). tra le facies relitte prevalgono quelle attribuibili a depositi alluvionali e colluviali continentali, a depositi di spiaggia e in subordine a complessi dunari, come inizialmente ipotizzato da segre (1968). dall’analisi dei profili risulta che le strutture ad onde di sabbia diminuiscono gradualmente di lunghezza e altezza e aumentano di frequenza, fino a scomparire alla profondità di 55 m. in questa fascia batimetrica si osserva la transizione ai fondi planari, interrotti alla profondità di circa 55 ÷ 60 m dal paleo-cordone litorale. le alghe rosse prevalgono nettamente a profondità più basse (45÷75 m) rispetto all’areale di distribuzione delle posidonie, e si sovrappongono con queste ultime solo parzialmente a profondità minori. ciò evidenzia una possibile complementarietà con le posidonie. infatti dove le posidonie hanno il maggiore accrescimento le alghe rosse non riescono ad essere competitive, avendo una struttura scheletrica molto più bassa, mentre al diradarsi della prateria per la diminuita luminosità ne risultano avvantaggiate. in questa fascia l’idrodinamismo delle tempeste rimuove episodicamente i sedimenti algali favorendo le specie variamente ramificate dei fondi incoerenti, mentre sulla cima del paleo cordone si osservano caratteristici pinnacoli prodotti piuttosto da specie di tipo incrostanti. nonostante nella zona campionata (t7-t8) la transizione tra la zona ad alghe rosse e quella più profonda a sedimenti sabbiosi fini a lamellibranchi si verifichi esternamente alla paleo-riva, si ritiene che quest’ultima costituisca un limite fisiografico-deposizionale che dovrà essere meglio definito dal prosieguo delle campionature nella piattaforma esterna. piattaforma esterna della piattaforma esterna si ha una buona definizione su base ecografica mentre della sedimentazione si hanno solo dati preliminari che documentano la presenza di sabbie fini fangose a lamellibranchi, foraminiferi ed echinidi irregolari. essa è individuabile esternamente alla paleo-riva dei –55 m, fino al bordo deposizionale della piattaforma posto a circa -115÷125 metri. l’ampiezza della piattaforma esterna, che costituisce l’infrastruttura per i fondali ricoperti dalle litofacies distali, è nettamente subordinata rispetto agli altri ambienti perché il livello eustatico di low-stand dei 1920 ky e i precedenti low-stand intercettavano il prisma deposizionale in prossimità della transizione alla parte profonda del bacino di cagliari; i sedimenti venivano pertanto deposti in condizioni poco stabili e in tempi brevi subivano processi di trasporto, granulare e di massa, verso il bacino. 7. discussione 7.1 ipotesi genetiche delle depressioni e del banco principale a posidonie la genesi delle depressioni e del banco principale a posidonie è decisiva per la comprensione del funzionamento sedimentario dell’intera piattaforma attuale. nella interpretazione di segre (1964) l’origine delle depressioni veniva attribuita alla erosione di valli fluviali durante la fase eustatica di low stand “wurmiana” (mis 4-2). riferendosi all’attuale funzionamento sedimentario della piattaforma, l’accrescimento del banco bioclastico a posidonie della piattaforma intermedia avrebbe sbarrato verso lo shoreface una depressione che costituirebbe una “laguna” fangosa silicoclastica e moderatamente carbonatica di mare temperato. questo implicherebbe, trascurando i fattori delle antecedenze di low stand, che l’alimentazione terrigena alla transizione shoreface-piattaforma intermedia non sia stata volumetricamente paragonabile all’accrescimento silicoclastico-carbonatico del banco verso l’alto, cioè abbia prevalso l’aumento di spazio disponibile (eustatic accomodation sensu posamentier et al., 1988) rispetto all’input terrigeno in shore face. una miglior ricostruzione deriva dall’interpretazione sequenziale delle registrazioni sub-bottom profiler (fig. 10) che evidenzia una genesi controllata contemporaneamente dai due fattori. si deduce che l’erosione di low stand, verificatosi lungo valli fluviali a est e a ovest di capo s. elia, abbia isolato delle colline; in fase di innalzamento eustatico le valli fluviali divenivano sede di lagune estuarine, mentre sulle colline si sono depposte sequenze sabbiose terrigene di shore-shoreface seguite, con l’annegamento, dall’instaurarsi del banco bioclastico a posidonie. col proseguire dell’innalzamento eustatico olocenico (maximum flooding), la depressione si sarebbe accentuata sia per la capacità del banco a posidonie di crescere verso l’alto, sia per il verificarsi di un deficit volumetrico di sedimenti nelle paleo-valli fluviali, derivato dalla retrogradazione dell’input terrigeno e dall’aumento dello spazio disponibile per l’innalzamento eustatico. pertanto i più recenti fattori di controllo di questa parte di piattaforma sarebbero individuabili nella presenza di paleo-morfologie del mis 2, nell’input terrigeno e nella produttività bioclastica. tali fattori hanno avuto entità paragonabili con una debole prevalenza della produttività carbonatica in fase di high stand (fig. 10). 7.2 definizione ed evoluzione della piattaforma nel quaternario il carattere essenzialmente bioclastico di gran parte della sedimentazione nell’intera piattaforma è chiaramente riferibile all’odierno contesto eustatico di high stand e alle condizioni di controllo della temperatura, salinità e limpidezza delle acque che permette condizioni di vita ottimali alle biocenosi a posidonie, ad alghe rosse, a molluschi e diverse altre. una tale pro218 l. lecca et al. duttività è comparabile ad altre aree del mediterraneo centrale e occidentale dove sono state descritte sedimentazioni carbonatiche come a ovest della sicilia e a est della tunisia (burollet, 1981; colantoni et al., 1993) e nelle isole baleari (mateu, 1989; fornos et al., 1991; fornos & ahr, 1997), ma nel golfo di cagliari si evidenzia una piattaforma articolata in ben diversificati ambienti. l’attuale morfologia del fondo marino caratterizza questa piattaforma e ne controlla i processi biologici, di trasporto e di deposizione. la presenza di aree depresse, attribuibili a paleo ambienti fluviali e costieri transizionali, contribuisce a confinare il terrigeno in piattaforma interna, mentre una fascia in rilievo distante dagli apporti terrigeni, in media piattaforma, costituisce un’areale ottimale per l’ecosistema a posidonia e, a maggiori profondità, per quelli algali, a lamellibranchi, echinidi e foraminiferi. il terrigeno prevale nello shoreface mentre nel resto della piattaforma viene prodotto sedimento carbonatico che, in piattaforma intermedia, si unisce ai sedimenti relitti terrigeni dando luogo a facies miste. nonostante il chiaro riconoscimento dell’attuale fase carbonatica, questa piattaforma non può essere definita carbonatica in senso stretto, perché durante tutto il tempo in cui tale piattaforma si è trovata in condizioni di livello eustatico più basso dell’attuale, fino ai massimi low stand, si sono avvantaggiati sempre più gli ambienti subaerei e di shoreface a sedimentazione continentale e sabbiosa terrigena. quindi i sedimenti relitti rappresentano un input terrigeno che si è realizzato maggiormente durante le fasi eustatiche di falling, low stand e rising, mentre la produttività bioclastica durante quella di high stand. in tal senso si può attribuire a questa piattaforma la seguente evoluzione con alterno comportamento. durante il “tirreniano” (mis 5) la piattaforma di cagliari ha funzionato come piattaforma carbonatica, probabilmente maggiormente produttiva dell’attuale, come si deduce dalla presenza di faune calde (carboni & lecca, 1985; carboni & lecca, 1992). durante la regressione “würmiana” (mis 4-2) le facies terrigene hanno raggiunto almeno la linea della paleoriva dei –55÷60 m e nella fase di massimo low stand le valli fluviali hanno inciso anche la piattaforma esterna (lecca et al., 1988). in seguito, nel post-glaciale, la risalita del mare ha rimaneggiato il terrigeno continentale in depositi sabbiosi di trasgressione (ravinement surface e trasgressive systems tract) fino a raggiungere l’attuale stadio di high stand systems tract terrigeno-carbonatico. possibili comparazioni con piattaforme mioceniche la distribuzione delle facies e l’evoluzione di questa piattaforma costituisce un modello, oltre che per le piattaforme quaternarie della sardegna e del mediterraneo, anche per le sequenze del miocene della sardegna, dove piattaforme miste heterozoan, prevalentemente ad alghe rosse, si sono impostate in un contesto trasgressivo a controllo tettonico, nel miocene inferiore (cherchi et al., 2000), e in un contesto regressivo nel miocene superiore (spano & barca, 2002). l’elemento di maggior interesse appare il controllo sulla produttività carbonatica di mare temperato operato dalla risalita eustatica, associata a bassi valori della subsidenza, come avviene attualmente nel golfo di cagliari, oltre ad altri fattori ambientali non considerati in questo lavoro e noti in letteratura (pomar et al., 2004). dal punto di vista della organizzazione spaziale della sedimentazione durante le fasi di high stand, deve essere sottolineata la contemporaneità delle facies terrigene “trasgressive” dello shoreface, con quelle carbonatiche della media piattaforma e l’inclinazione dello shoreface verso il bacino; tale architettura deposizionale implica la non coincidenza dei limiti litostratigrafici con le isocrone, come già illustrato nei modelli di stratigrafia sequenziale (e. g. sarg, 1988). 8. conclusioni una nuova campionatura e nuovi dati ecografici hanno consentito di meglio documentare e interpretare la presenza di una sedimentazione carbonatica di mare temperato nella piattaforma del golfo di cagliari. sono stati individuati 8 gruppi di litofacies che testimoniano la presenza di altrettanti distinti ambienti deposizionali, di cui è stata presentata una prima zonazione cartografica. dove la sedimentazione non risente di una sensibile produzione bioclastica i dati hanno confermato i modelli di sedimentazione delle spiagge sottomarine terrigene. nelle aree a sedimentazione mista, la zonazione è risultata più complessa e controllata da fattori sia idrodinamico-batimetrici che biologici. tale piattaforma è sede di un sistema sedimentario complesso che si evidenzia con processi deposizionali controllati dalla paleo-morfologia, in particolare legata all’ultimo stazionamento basso del mis 2, dal trasporto terrigeno, dall’energia del moto ondoso e dalla produttività carbonatica organogena. l’attuale contesto risulta quello di uno shelf wave-dominated “attenuato”, a clima caldo mediterraneo, con scarsi apporti terrigeni e importante produttività carbonatica in piattaforma intermedia e sedimenti relitti a diversi livelli batimetrici. i risultati portano a non considerare questa piattaforma come una rampa silicoclastica distalmente gradata, come ci si potrebbe aspettare dalla posizione “pericontinentale” e dalla presenza di apporti terrigeni a spese di rocce cristalline. l’associazione di due ambienti speciali come la depressione interna e il banco della piattaforma intermedia, infatti, caratterizzano la piattaforma di cagliari e le fanno assumere aspetti fisiografici e sedimentologici di tipo piattaforma carbonatica di mare temperato, nonostante il terrigeno sia comunemente presente. la produttività carbonatica ha prevalso nell’attuale high stand e negli altri precedenti del pleistocene medio-superiore, mentre i sedimenti relitti testimoniano una sedimentazione terrigeno-silicoclastica che ha prevalso durante le fasi glacio-eustatiche di falling, low stand e rising in ambienti di shoreshoreface, transizionali e fluvio-alluvionali. ringraziamenti il rilievo dei profili ecografici e il lavoro di campionatura sono stati eseguiti grazie alla disponibilità e alle competenze del corpo forestale e di vigilanza ambientale della regione sardegna (resp. s.v.m. dott. stefano orrù, dir. s.t.i.r. dott. paolo floris), che ha messo a disposizione i mezzi e il personale a cui vanno i nostri più sentiti ringraziamenti, in particolare alla base 219i sedimenti terrigeno carbonatici ... logistica operativa navale di cagliari (isp. c. salvatore barabino, isp. c. angelo piga, ass. antonio pira, ass. gianni dedola, ass. bruno cara, ass. marco mentisci, ass. carlo degioannis e ass. paolo locci). si ringraziano i revisori per la lettura critica e i consigli per la correzione del manoscritto. lavoro realizzato nell’ambito dei progetti: università degli studi di cagliari (m.i.u.r., 60%): “evoluzione dei bacini neogenico-quaternari del blocco sardo-corso: analisi tettono-sedimentarie stratigrafiche, sedimentologiche, paleoclimatiche e confronti con altre aree” (responsabile l. lecca). gruppo nazionale difesa catastrofi idrogeologiche, (g.n.d.c.i.-c.n.r.): “prevenzione e previsione degli eventi franosi a grande rischio – interlinea difesa dei litorali – unità operativa sardegna” (responsabile s. de muro). bibliografia adey w.h. & macintyre i.g. (1973) crustose coralline algae: a re-evaluation in the geological sciences. geol. soc. am. bull., 84, 883-904. allen j.r.l. (1982) transverse bedforms in multidirectional flows: wave-related ripple marks, sand wavws, and equant dunes. in developments in sedimentology, allen j.r.l. ed., 30a, 419-470, elsevier. bacelle l. & bosellini a. (1965) diagrammi per la stima visiva della composizione percentuale nelle rocce sedimentarie. annali univ. di ferrara, sez. ix, vol. 16, 19-40. boudoresque c.f., meinesz a. & verlaque m. (1992) guides des algue des mers d’europèe. méditerranée. delachaux et niestlé, 139-219. burollet p.f. (1981) the pelagian sea east of tunisia: bioclastic deposit under temperate climate. marine geology, 44, 157-170. carannante g., esteban m., milliman j.d. & simone l. (1988) carbonate lithofacies as paleolatitude indicators: problems and limitations. sedimentary geology, 60, 333–346. carboni s. & lecca l. (1985) osservazioni sul pleistocene medio-superiore della penisola del sinis (sardegna occidentale). boll.soc.geol.it., 104, 459-477. carboni s. & lecca l. (1992) quaternary carbonate sedimentation in the western sardinian shelf. xxxiiie congr.-ass. plénière de la ciesm, trieste 1992, 123. carboni s. & lecca l. & ferrara c. (1989) la discordanza versiliana sulla piattaforma continentale occidentale della sardegna. boll.soc.geol.it., 108, 503-519. carta m., del fa’ c., ulzega a. & uras i. (1986) la piattaforma continentale sarda, studi geogiacimentologici, geofisici, sedimentologici e di valorizzazione dei minerali contenuti. in p.f. oceanografia e fondi marini, sottoprogetto risorse minerarie, rapporto tecnico finale, cnr, roma 1986, 1-35. casula g., cherchi a., montadert l., murru m. & sarria e., (2001) the cenozoic graben system of sardinia (italy): geodynamic evolution from new seismic and field data. marine and petroleum geology 18, 863-888. cherchi a. & montadert l. (1982) il sistema di rifting oligo-miocenico del mediterraneo occidentale e sue conseguenze paleogeografiche sul terziario sardo. mem.soc.geol.it., 24, 387-400. cherchi a., murru m. & simone l. (2000) miocene carbonate factories in the syn-rift sardinia graben subbasins (italy). facies, 43, 223-240. colantoni p., ligi m., morsiani m. p., penitenti d., (1993) morphology and recent sedimentary evolution of the western sicilian continental shelf geological development of the sicilian-tunisian platform. unesco reports in marine science, 58, 93-98. contu a., lecca l., leone f., mulas p., sarritzu g., schintu m. & ulzega a. (1983) indagine chimica e geomorfologica nel golfo di cagliari. atti 5° congr. aiol stresa 1982, 349-364. cossellu m. (2003) prima zonazione tessiturale e composizionale dei sedimenti attuali della piattaforma continentale del golfo di cagliari (parte orientale). università degli studi di cagliari, tesi di laurea inedita, 1-285. cottiglia m., maxia c. & tagliasacchi m.l. (1973) l’inquinamento dello stagno di cagliari. la programmazione in sardegna. 48, 31-47. d’angelo g. & gargiullo s. (1978) guida alle conchiglie mediterranee. fabbri ed., milano, 224 pp. de muro s. & kalb c. (2003) carta geo-litologica dei fondali marini compresi tra capo boi e torre de su fenugu. sardegna sud-orientale. congresso naz. geosed alghero, sardegna, 2003. de muro s. & orrù p. (1998) il contributo delle beach–rock nello studio della risalita del mare olocenico. le beach–rock post–glacial i della sardegna nord–orientale. il quaternario, 11 (1), 19–39. finetti i.r., del ben a., fais s., forlin e., klingele e., lecca l., pipan m., prizzon a. (2005) crustal tectono-stratigraphic setting and geodynamics of the corso-sardinian block from new crop seismic data. in i. r. finetti editor, crop deep seismic esploration of mediterranean region. elsevier, in press. fornos j.j., forteza v., jaume c., martinez–taberner a. (1991) present-day halimeda carbonate sediments in temperate mediterranean embayments: fornells, balearic islands. sedimentary geology, 75, 283–293. fornos j.j. & ahr w.m. (1997) temperate carbonates on a modern, low-energy, isolated ramp: the balearic platform, spain. journal of sedimentary reserch, 67, 364–373. inman d.l. (1952) measures for describing the size distribution of sediments. jour. sed. petr., 22, 35, 354-365. johnson j.h. (1962) the algal genus lithothamnium and its fossil rapresentatives. golden, colorado, colorado school of mines, vol. 57, 1, 1-111. johnson j.h. & adey w. h. (1965) studies of lithophyllum and related algal genera . golden, colorado, colorado school of mines, vol. 60, 1, 1-105. lecca l., carboni s., ferrara c., marchi m., de muro s., pisano s., tilocca g., ibba a., panizza v., pin220 l. lecca et al. tus c., gallus m., muscas a., pani d. (1988) report on cruise mcs/87 (western and southern margin of sardinia). rend. soc. geol. it., 11, 73–74. lecca l., panizza v., pisano s. (1998) the sedimentary framework of cagliari basin: a plio–quaternary underfed rift basin in the southern sardinian margin. il quaternario, 11 (2), 301–318. lees a. (1975) possibile influence of salinity and temperature on modern shelf carbonate sedimentation. marine geology, 19, 159-198. lees a. & buller a.t. (1972) modern temperate-water and warm-water shelf carbonate sediments contrasted. marine geology, 13, 67-73. leone f., pontillo c. & spano c. (1992) benthic paleocommunities of the middle-upper miocene lithostratigraphic units from the cagliari hills (southern sardinia, italy). cont. to the geology of italy. vol. dedicated to tommaso cocozza. l.carmignani & f.p.sassi eds, igcp n.276, newsletter vol. 5, siena 1992, 151-158. mateu g. (1989) la bahía de palma de mallorca (baleares-espana) y los recientes estudios geosísmicos, bionomico-sedimentarios y micropaleontologicos en un litoral de dificil regeneracion antropica. rev. cièn. (ieb), 4, 65-81. martinson d.g., pisias n.g., hays j.d., imbrie j, moore t.c. & shackleton n.j. (1987) age dating and the orbital teory of the ice ages: development of a high-resolution 0 to 300.000 year chronostratigraphy. quat. res., 27, 1-29. mc cave i.n. & langhorne d.n. (1982) sand waves and sediment transport around the end of a tidal sand bank. sedimentology, 29, 95-110. metallo a. (1971) correnti marine e temperature delle acque superficiali. in pracchi r. & terrosu-asole a., atlante della sardegna. la zattera editrice cagliari, 17-19, tavv. 9-10 mosetti f. (1977) le acque, il nostro universo. utet, torino, 579 pp. pau m. (2003) prima zonazione tessiturale e composizionale dei sedimenti attuali della piattaforma continentale del golfo di cagliari (parte occidentale). università degli studi di cagliari, tesi di laurea inedita, 1-234. pecorini g. (1966) sull' età "oligocenica" del vulcanismo al bordo orientale della fossa tettonica del campidano (sardegna). acc. naz. lincei, 33, 1058-1065. pecorini g. (1986) considerazioni geomorfologiche intorno a s. igia (stagno di s. gilla,cagliari). in “s. igia, capitale giudicale”, ist. storia medioevale, univ. cagliari, ets ed. pisa, 15-20. pecorini g. & pomesano cherchi a. (1969) ricerche geologiche e biostratigrafiche sul campidano meridionale (sardegna). mem. soc. geol. it., 8, 421-451. peres j.m. & picard j. (1964) nouveau manuel de bionomie benthique de la mer méditerranée. rec. trav. sta. mar. endoume, bull., 31, 59–63. piccazzo m., tedeschi d. & vannucci g. (1981) analisi di sedimenti marini superficiali della sardegna meridionale. quaderni dell’istituto di geologia della università di genova, 2, 39-60. pinna m. (1971) piovosità e tipi di clima in sardegna. in pracchi r. & terrosu-asole a., atlante della sardegna. la zattera editrice cagliari, 49-57, tav.26. pomar l. (2001) types of carbonate platforms, a genetic approach. basin research, 13: 313-334. pomar l, brandano m., westphal h. (2004) envinmental factors influencing skelethal grain sediments associations: a critical review of miocene examples from the western mediterranean. sedimentology, 51, 627 651. posamentier h.w, jervey m.t. & vail p.r. (1988) eustatic controls on clastic deposition i: conceptual framework. in sea level changes-an integrated approach, sepm special publ. 42, 109-124. raimondi s., baldacini p: & madrau s. (1995) il clima ed il pedoclima dei suoli della sardegna durante gli anni 1951-80. in soc.it.sc.suolo, conv. ruolo della pedologia, cagliari 1995, 299-308. riding r. (2002) structure and composition of organic reefs and carbonate mud mounds: concepts and categories. earth-science review, 58, 163-231. riedl r. (1991) fauna und flora des mitterlmeeres. verlag paul parey, hamburg–berlin, 777 pp. sarg j. f. (1988) carbonate sequenze stratigraphy. in sea level changes, an integrated approach, sepm special publ. 42, 154-181. segre a.g. (1968) linee di riva sommerse e morfologia della piattaforma continentale italiana relative alla trasgressione marina versiliana. quaternaria, 11, 1–14. serra a. (1971) venti al suolo, tav. 17. in pracchi r.& terrosu-asole a., atlante della sardegna. la zattera editrice cagliari, pp 39-41. spano c. & barca s. (2002) ecobiostratigraphic, lithostratigraphic, depositional and synthemic setting of cenozoic units in southern sardinia (italy). boll.soc.geol.it. 121, 19-34. swanson r.g. (1985) sample examination manual. aapg, 35 pp.. ulzega a., leone f., orrù p. (1986) geomorphology of submerged late quaternary shorelines on the south sardinian continenal shelf. journal of coastal research, si (1), 73–82. unesco (1977) marine ecosystem modelling in the mediterranean – report of the second unesco workshop on marine ecosystem modelling. unesco reports in marine sciences, 1-111. 221 ms. ricevuto l’1 giugno 2005 testo definitivo ricevuto il 19 ottobre 2005 ms. received: june 1, 2005 final text received: october 19, 2005. i sedimenti terrigeno carbonatici ... ojs 646 capraromaiorano_2 36,1 39-61.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 36 (1), 2023, 39-61 italian gssps of the quaternary system luca capraro1, patrizia maiorano2 1 università di padova, dipartimento di geoscienze, padova, italy. 2 università di bari, dipartimento di scienze della terra e geombientali, bari, italy. corresponding author: luca capraro <luca.capraro@unipd.it> abstract: italy offers an extraordinarily complete and well exposed record of recent open-marine sediments that have been employed for centuries to establish geological standards of the neogene and the quaternary. over the last decades, the very same successions provided a benchmark for validating ever newer methodologies and techniques in earth sciences that contributed dramatically to establishing the modern geologic time scale. the stratigraphic record of southern italy and sicily played a key role in developing the astronomical time scale (ats) and provided physical reference in the definition of global stratotype sections and points (gssps) for the current lower pleistocene stages (gelasian and calabrian). here, we discuss and summarize the state of the art of the gelasian and calabrian stages, considering the recent advances and ongoing work. keywords: chronostratigraphy, quaternary system, pleistocene, gssps, italy. 1. introduction since the early days of stratigraphy, earth scientists have felt a compelling need for a precise, practical, and globally accepted subdivision of the geologic time. establishing a reference time scale is of the essence for chronicling life evolution and past geological events, not unlike a calendar delving into the earth’s deepest past. however, the concept of “deep” geological time extending billions of years beyond the human experience is far from easy to conceive and manage. not by chance, reasonable estimates of the earth’s age have been attained only recently, after the discovery of radioactivity. the development of increasingly convenient and precise methods for dating rocks during the 19th century was punctuated by major breakthroughs, not only in establishing the order of magnitude of our planet’s age, but also in providing means for subdividing the geological record into units of practical use for earth scientists. result of these efforts is the modern geologic time scale (gts), which is ultimately intended to provide a standard common language for earth scientists globally. the gts is based on two strictly intertwined scales, these being an absolute time scale, composed of geochronologic units (gcus) as formalized intervals of the geologic time, and a relative time scale, which classifies rocks into chronostratigraphic units (cus) based on their age (tab. 1). construction of the gts has been hampered over time by several problems, many of which have not been solved so far. they include scientific limits, such as the accuracy and correlation potential of the employable dating tools, and theoretical drawbacks, such as the age-old disagreements on stratigraphic philosophy and procedures in establishing formal units. the gts is bound to be an endless enterprise, because the improving service ability of stratigraphic tools and the implementation of new methodologies strive in keeping up with the ever-growing need for better age constraints and long-distance correlation. even the (apparently easy) goal of an international agreement upon rules, procedures, and standards in stratigraphy is far from being accomplished, to great detriment of the whole scientific community. 2. the geological time scale: past, present, future the origins of modern chronostratigraphy date back to 1669, when nicholas steno, in the attempt of describing the geology of tuscany, formulated three basic rules known as steno's principles that have since become fundamental to stratigraphy. following steno’s principles, italian scholar giovanni arduino conceived in 1759 what is acknowledged as the first ever formal classification of the geological time. based on the study of rocks exposed in northern italy, he subdivided the earth’s history into four periods: primary, secondary, tertiary, and quaternary. in 1816, the seminal work “strata identified by organized fossils” by william smith introduced the principles of faunal suchttps://doi.org/10.26382/amq.2023.02 cession and long-distance correlation and laid the foundations for modern biostratigraphy. during the xix and early xx centuries, the first “modern” gts was established by introducing the large-scale chronostratigraphic subdivisions (i.e., eras and periods) that are still in use today. lower-rank cus (i.e., stages) were introduced shortly after, although their definitions, boundaries, and use remained for a long time ambiguous. the discovery of radioactivity at the end of the 19th century paved the way for radiometric dating of crystalline rocks. this finally gave the opportunity to establish the order of magnitude of the earth’s age, and laid the foundations for the modern gts (holmes, 1960). in the late 1960s, radiometric ages and the history of polarity reversals of the earth’s geomagnetic field obtained from lava successions were eventually merged to create the first geomagnetic polarity time scale (gpts; heitzler et al., 1968). technologic advances in measuring the magnetic properties of rocks, paralleled by new biostratigraphic scales based on planktonic microfossils retrieved from deep-sea sediment cores, were a game-changer in linking the sedimentary records to the gpts. paleomagnetic reversal recognized and dated in volcanic rocks could also be detected in sedimentary successions and calibrated to the bioevents found in the very same records (biomagnetochronology) (fig. 1). this step promoted a new generation of gts, where cu boundaries and the geological events within were finally assigned an absolute radiometric age (e.g., harland et al.,1982; snelling, 1985; berggren et al., 1995). advancements made in the early 1990s allowed exploiting the pervasive cyclicity preserved within the stratigraphic record for deriving a new stable and extremely precise geochronometer independent of radiometry. this groundbreaking approach relates depositional, geochemical, and palaeontologic cycles in sedimentary rocks to the periodical variations of earth’s orbital parameters, the chronology of which (fig. 1) has been firmly established by means of mathematical models (e.g., laskar et al., 2010). although relatively simple for the most recent part of the geologic record (miocene to recent), correlation becomes increasingly challenging as we move back in time, due to the chaotic behavior of the solar system (laskar, 1990). the resultant astronomical time scale (ats; shackleton et al., 1990; bergreen et al., 1995; hilgen et al., 1997; lourens et al., 2004), currently in progress, is globally acknowledged as the most reliable and consistent chronology available to date for the last ca. 250 myr, even if its use is now being extended into the paleozoic (gradstein et al., 2020). 3. definition of chronostratigraphic units and boundaries the first, yet unsuccessful, formal attempt at establishing a common terminology and philosophical approach in defining stratigraphic ranks and boundaries dates back to the international geological congress of bologna, 1881. still, it was not until the publication of the international stratigraphic guide of hedberg (1976) that rules and procedures in stratigraphy were formalized and internationally agreed upon, albeit not universally. one of the key practical procedures proposed by hedberg was establishing individual stratigraphic units (of any type, scope, and rank) by means of a formalized boundary stratotype, namely “a specific point in a specific sequence of rock strata that serves as the standard for definition and recognition of a stratigraphic boundary” (hedberg, 1976). cowie et al. (1986) emended hedberg’s definition by introducing the concept of global stratotype section and point (gssp), a sort of boundary stratotype to be specifically employed for establishing global standard geochronologic/chronostratigraphic units of the gts. in the new edition of the guide, salvador (1994) better defined gssp as “a specified sequence of rock strata in which a specific point is selected that serves as the standard for definition and recognition of a stratigraphic boundary”. although the differences may seem marginal, the gssp concept of salvador (1994) as “a specified sequence of rock strata” is more practical and functional than the former hedbergian concept of boundary stratotype, which made reference to a dimensionless “point” in rocks. the gssp-oriented approach has proved effective in establishing many formal cus over the last decades, with great advantage for the global scientific community. there is an ongoing debate on the most recommendable procedures and strategies to be used in defining future formal cus and their boundaries, however delving into details is beyond the scope of this paper. still, it is undisputable that a gts based on gssps only holds several inherent drawbacks. gssps define the base of “topless” stages, as their upward chronostratigraphic extent is only limited by the gssp of the stage immediately above, if available. in contrast, the intervening (and most conspicuous) stratigraphy may be completely void of information. in the attempt to address this “empty stages” problem, aubry et al. (1999) revived the concept of unit stratotype, as formerly defined by hollis hedberg: “…the most effective means of providing a chronostratigraphic unit with fixed and uniform limits to 40 capraro l., maiorano p. tab. 1 hierarchy of formal chronostratigraphic and geochronologic units. fig. 1 late neogene/quaternary chronostratigraphic scheme. left to right: 1) the astronomical time scale (after gradstein et al., 2020); 2) chronostratigraphy of the interval of relevance. stage 4 corresponds to the upper pleistocene subseries, not yet defined. the lower, middle, and upper holocene subseries (*/**/***) and their respective stages greenlandian, northgrippian and meghalayan (1/2/3) are not shown; 3) the lr04 benthic δ18o stack of lisiecki and raymo (2005); 4) mediterranean planktonic foraminifera and calcareous nannofossils biostratigraphy. bioevents have been traced according to the independent biochronology of lirer et al. (2019) for planktonic foraminifers and lourens et al. (2004) and gradstein et al. (2012) for calcareous nannofossils. fo: first occurrence; lo: last occurrence; fco first common occurrence; lco: last common occurrence; pb: paracme beginning; pe: paracme end; lro: last regular occurrence; l.c.: left-coiled; 5) sapropel stratigraphy; 6) composite mediterranean sea-surface water temperature record, integrated with the montalbano jonico dataset of marino et al. (2020). italian gssps of the quaternary system 41 fig. 2 the proposed unit-stratotype for the zanclean and piacenzian stages at the rossello composite section (sicily), with biostratigraphy, sedimentary cycles and their astronomical tuning. from hilgen et al. (2020). 42 capraro l., maiorano p. which all workers can return for reference, appears to be the designation of a specifically bounded section of rock strata as the stratotype of this unit. thus, the scope of a stage appears to be best defined as the rocks anywhere in the world corresponding in age to the total time-interval represented by the rocks between horizons designated as marking the top and the bottom of that stage in i ts type sect ion or s t ratotype” (hedberg, 1965). hilgen et al. (2020) made a further step ahead by introducing the concept of astronomical unit stratotype (fig. 2), a type of supercu to be defined in cyclical deep-marine successions amenable to astronomical tuning. this approach would secure accurate age control for each and any of the geological events documented within, thus minimizing the chance of formalizing cu bodies harboring an incomplete or not continuous stratigraphic record. individual strata could be defined as chronozones, i.e., nonhierarchical chronostratigraphic units to be employed for ultra-high-resolution studies (hilgen et al., 2006). in this respect, the mediterranean stratigraphic successions that served for constructing the ats are perfectly suited as reference sections for defining the astronomical unit stratotypes for the neogene and quaternary stages, as soon as their use will be approved by the competent scientific bodies. 43 tab. 2 current subdivision of late neogene/quaternary system as approved by the international commission on stratigraphy and ratified by the international union of geological sciences, with indication of age and location of the global boundary stratotype sections and points (gssps) defined so far. italian gssps of the quaternary system fig. 3 location map of the stratigraphic sections mentioned in the text. in red, location of the zanclean (eraclea minoa), piacenzian (punta piccola), gelasian (monte san nicola) and calabrian (vrica) type sections. 4. the italian quaternary record italy has long been the breeding ground for many geological concepts and models, as well as an exceptional test bench for the definition of chronostratigraphic standards (krijgsman, 2002; rio et al., 2004). in particular, the italian neogene and quaternary stratigraphic record played a key role in all the accomplishments listed above (tab. 2). in subdividing the tertiary and quaternary into stages, lyell (1833) made reference to italian sections that even today are of scientific interest. in the current gts, a vast majority of the formal stages defined so far for the pliocene and the pleistocene (i.e., zanclean, piacenzian, gelasian, and calabrian) have been established in southern italy and sicily (fig. 3, tab. 2). in addition, a plethora of cus not validated globally, because obsolete, regional in scope, or ambiguous in their definition (e.g., the astian, tabianian, emilian, santernian, sicilian, selinuntian, ionian, crotonian, milazzian, tyrrhenian, and tarentian) (vai, 1996; rio et al., 1991; cita & castradori, 1995; cita et al., 2006; lirer & iaccarino, 2011), are still informally employed today when dealing with mediterranean successions (tab. 3). the proliferation of regional stages was fostered by the plenty of recent marine sediments exposed along the coastlines of sicily and southern italy in response to the active geodynamic history of the mediterranean, which prompted the uplift of a globally unrivalled deep-water neogene and quaternary stratigraphy. furthermore, the elongated italian peninsula and its submerged extension, the shallow sicily strait, form a meridional divide separating the mediterranean sea into two (western and eastern) subbasins, each characterized by peculiar climatic and oceanographic conditions. for this reason, the central mediterranean borderlands (i.e., italy and surrounding regions) are a sensitive sounding board for climate changes at both the global and regional scales (giorgi, 2006). central mediterranean open-marine sediments hold a pristine record of the regional biotic and environmental response to climate forcing, such as marine productivity, precipitations and freshwater runoff, zonal and vertical circulation patterns, terrigenous yield, etc. in particular, the stratigraphy exposed along the coasts of italy and sicily is usually organized cyclically, and thus amenable to astrocyclostratigraphic investigations. not surprisingly, the first ats was established in the early 1990s by merging the pliocene rossello composite section (southern sicily; langereis and hilgen, 1991) with the lower pleistocene singa and vrica sections (ionian calabria; hilgen, 1991a,b; hilgen et al., 1997). key tools for validating the astronomical tuning of open-marine mediterranean records since the miocene are the notorious dark, organic-rich layers known as sapropels. mediterranean sapropels formed during periods of maximum insolation (hilgen, 1991b; hilgen et al., 1993, 1995, 1999; lourens et al., 1996, 2001; rohling, 2015), which is attained under conditions of minimum precession and maximum eccentricity of the earth’s orbit around the sun, so they are usually found in distinct clusters of 3 to 5 individuals. their preservation potential and physical traits change accordingly to depositional settings. in the deep (pelagic) domain, where sediment accumulation rates are extremely low, sapropels occur as very thin layers of massive blackish muds. in the predominantly hemipelagic record of southern italy, where the terrigenous input is massive, they are usually found as thick, thin-laminated sapropelequivalent layers, commonly referred to as “laminites”. 5. italian quaternary gssps due to the debated 2009 resolution of lowering the base of both the pleistocene series/epoch and the quaternary system/period to ca. 2.588 ma (gibbard & head, 2010; gibbard et al., 2010), the lower pleistocene subseries currently includes two formally defined stages, these being the gelasian (ca. 2.588 to 1.806 ma) and the calabrian (ca. 1.806 to 0.772 ma). the first was defined in the monte san nicola section (fig. 4), near the town of gela (southern sicily; rio et al., 1998), while the second was established in the vrica section (fig. 5), crotone (ionian calabria, southern italy; cita et al., 2012), where the former neogene/quaternary boundary was defined by aguirre & pasini (1985). both sections have been subjected to astrocyclostratigraphic investigations and contributed as physical reference to 44 capraro l., maiorano p. tab. 3 some of the the chronostratigraphic subdivisions proposed in the past for the quaternary based on traditional (either formally defined or not) mediterranean stages. modified from rio et al. (1991). readers are encouraged to refer to vai (1996) for further details and discussion on the matter. the construction of the current ats (hilgen et al., 1997, 2006). the vrica and monte san nicola sections are represented by slope to outer shelf clayey marls that contain no evidence of erosional surfaces, hiatuses, abrupt variations in sediment composition and/or changes in the sedimentation style, which was persistently dominated by mud settling (capraro et al., 2022). clustered sapropel layers occur in both records (figs. 4c-d, 5d-e) and provide mutual correlation in the interval straddling the gelasian/calabrian boundary (capraro et al., 2022). unfortunately, the vrica section does not extend up to the base of the middle pleistocene subseries (lourens et al., 1996). however, several openmarine records, both from the same crotone basin (capraro et al., 2011) and southern italy (montalbano jonico section, basilicata, southern italy; ciaranfi et al., 2010), overlap with the vrica section and extend seamlessly at least up to mis 17/mis 15. indeed, maiorano et al. (2010) proposed the spliced vrica and montalbano jonico record as a potential unit-stratotype of the calabrian stage. 6. the gelasian stage the gelasian was formally defined as the third and uppermost stage of the pliocene series (rio et al., 1998). for decades, the pliocene had been subdivided into two stages only, namely the zanclean (van couvering et al., 2000) and the piacenzian (castradori et al., 1998). in spite of its current gssp location in southern sicily, the piacenzian was named after the area in northwestern italy where the relevant historical typesection is exposed, namely the arda valley (piacenza province). the pliocene to pleistocene stratigraphy of the val d’arda (fig. 3) was mentioned by lyell (1833) as the marine “type” of his “older pliocene”, and later employed by barbieri (1967) for defining the traditional piacenzian stage (mayer-eymar, 1858; pareto, 1865), which was believed to extend up to the base of the pleistocene. however, rio et al. (1988) and raffi et al. (1989) discovered that the lithological change at the top of the historical piacenzian stratotype, marked by a transition from open-marine muds to regressive yellow sands (the “astian” auctorum), occurs close in age to 45 italian gssps of the quaternary system fig. 4 the monte san nicola section, sicily, where the gssp of the gelasian is located. a) geographic location of the gssp (from gradstein et al., 2020); b) location of the monte san nicola area within the caltanissetta basin (from capraro et al., 2022); c) profile of the type section and location of the gssp, with sapropel clusters o-c; d) reddish, thin-laminated layers alternated to brown, nonlaminated manganesiferous layers of sapropel clusters o and a. 46 fig. 5 the gssp for the calabrian stage in the vrica section, calabria. a-b) outcrops and location of the gssp (from gradstein et al., 2020); c) exposure of the a, b and c component segments of the vrica composite section; d-e) exposure and position of the calabrian gssp, with indication of sapropel layers b to e (from cita et al., 2012). capraro l., maiorano p. the global climate cooling at about 2.6 ma. this event was usually referred to as “the beginning of the ice ages” (e.g., shackleton et al., 1984). accordingly, it was demonstrated that the historical piacenzian stratotype does not provide a continuous open-marine sedimentary record up to the pliocene/pleistocene boundary, as defined in the vrica section (aguirre & pasini, 1985). furthermore, an urgent need was felt within the quaternary scientific community to acknowledge the importance of the climatic event at 2.6 ma by emphasizing its visibility in the gts. in the attempt to address both these issues, rio et al. (1988, 1991) questioned the common practice of extending the piacenzian up to the base of the pleistocene (e.g., barbieri, 1967; cita, 1973; berggren et al., 1985), and proposed establishing a new upper pliocene stage corresponding to the “astian yellow sands” of the val d’arda section (rio et al., 1994). since the latter consist of shoreface sands inadequate to host a gssp (hedberg, 1976; salvador, 1994), it was agreed to define the new stage in the open-marine muds of the monte san nicola section (southern sicily), in the very same caltanissetta sedimentary basin (fig. 4b) where the zanclean and piacenzian gssps are also located (van couvering et al., 2000; castradori et al., 1998). the singa section (ionian calabria) was also taken into consideration as a potential gssp candidate, but monte san nicola offers easier access and best exposure conditions (rio et al., 1998). the name “gelasian” was after the nearby city of gela (rio et al., 1994). 6.1. the monte san nicola section the monte san nicola stratigraphy crops out in form of a beautifully exposed suite of badlands (fig. 4c) few kilometers inland from the coastal city of gela (southern sicily). the succession was laid in the southeastern limb of the caltanissetta sedimentary basin (fig. 4b), a late neogene structure confined by the front of the maghrebian-apennine chain and the hyblean foreland (catalano et al., 2013; lentini & carbone, 2011, 2014). according to lickorish et al. (1999), the caltanissetta basin consists of a single thrust sheet containing a train of continuously tightening folds belonging to the “gela nappe” of beneo (1958) and ogniben (1969). the gela nappe includes various sedimentary units, ranging from the cretaceous-eocene “argille scagliose” (ogniben, 1969) to the serravalliantortonian “numidian flysch” (gasparo morticelli et al., 2015; pinter et al., 2016, 2018). small piggy-back basins developed within the caltanissetta basin in response to complex compressive-translational and rotational movements, and provided accommodation to an expanded upper neogene and quaternary stratigraphy (ogniben, 1969; catalano et al., 1977; grasso et al., 1987; lentini et al., 1991; vitale, 1996; lickorish et al., 1999; ghisetti et al., 2009; gasparo morticelli et al., 2015). in keeping with the reference capo rossello succession, the open-marine pliocene and pleistocene record at monte san nicola belongs to the “trubi” and “monte narbone” formations (fig. 6). the former (zanclean-piacenzian p.p.; cita & gartner, 1973; castradori et al., 1998) consists of cyclically organized, off-white marly limestones and grey/beige marls, void of macrofossils, laid at an estimated depth of ca. 1000 m (bonaduce & sprovieri, 1984) in response to the abrupt reprise of deep marine sedimentation after the messinian salinity crisis (de visser et al., 1989). probably due to tectonic obliteration, the entire messinian to lower piacenzian stratigraphy is missing at monte san nicola, as the trubi fm. is only represented by its upper part (ca. 40 m) resting directly on top of the numidian flysch (rio et al., 1994, and references within). the rapid but gradual transition from the trubi to the overlying monte narbone fm. (piacenzian p.p.-calabrian p.p.; rio et al., 1984; di stefano et al., 1993) is associated to a massive increase in terrigenous input. this change is emphasized by sediment colors turning to deep blue/ tobacco, decreasing rock competence, an upward increase in the average sediment accumulation rates (capraro et al., 2022) and the appearance of sapropels, which either occur as reddish, thin-laminated intervals or brown, non-laminated manganesiferous layers (fig. 4d). the estimated water depth decreases from ca. 1000 m in the basal part of the unit to ca. 500 m at its top (rio et al., 1994, and references therein). in the monte san nicola area, the monte narbone fm. is ca. 125 m thick. however, its original thickness cannot be estimated, because the unit is truncated by a package of richly fossiliferous yellow sands belonging to the shallow-water agrigento fm. (calabrian) documenting the definitive uplift of the area. 6.2. previous studies on the monte san nicola section the monte san nicola section was first studied by spaak (1983), who investigated the planktonic foraminifer assemblages, and bonaduce & sprovieri (1984), who reported on the fossil ostracods record. the sapropel-equivalent layers exposed in the monte san nicola badlands were the focus for the work of sprovieri et al. (1986) and howell et al. (1988), who investigated the age and formation mechanisms of laminitic intervals. driever (1988) analyzed the calcareous nannofossil record, followed by bertoldi et al. (1989) who employed segments of the monte san nicola succession in the attempt to reconstruct the long-term evolution of vegetation and climate across the pliocene-pleistocene boundary. hilgen (1991a) exploited the cyclically organized monte san nicola succession for constructing the ats, while channell et al. (1992) achieved a sharp magnetostratigraphic record of the gauss/matuyama geomagnetic reversal close to the piacenzian-gelasian boundary (fig. 6). the same work provided detailed quantitative biostratigraphy based on planktonic foraminifera and calcareous nannofossils (fig. 6) and demonstrated that the monte san nicola open marine stratigraphy extends from the planktonic foraminifera zone mpl3 to the globigerina cariacoensis zone (cita, 1973, 1975, emended by sprovieri, 1992) (fig. 6), and from the calcareous nannofossil reticulofenestra pseudoumbilicus (mnn14/15) zone to the calcidiscus macintyrei (mnn19b) zone of rio et al. (1990) (fig. 6). the section thus extends from the late zanclean (>4 ma) to the early calabrian (ca. 1.6 ma). 47 italian gssps of the quaternary system 6.3. definition of the gelasian gssp the gelasian gssp was formally ratified (rio et al., 1998) at the base of the marly unit that overlies a prominent laminitic layer, known as “nicola bed” (after monte san nicola), representing the uppermost mediterranean precession-related sapropel (mprs) of cluster a (verhallen, 1987; hilgen, 1991b). the “nicola bed”, well exposed regionally (e.g., castradori et al., 1998), is correlative to mprs 250 (i-cycle 250) of lourens et al. (1996), in the midst of interglacial marine isotopic stage (mis) 103 (figs. 1, 7). the astronomically calibrated age of the boundary is 2.588 ma (hilgen, 1991a; rio et al., 1998). according to the gssp definition (rio et al., 1998), the piacenzian/gelasian boundary occurs in mis 103, and predates by ca. 60 kyr the glacial mis 100 (fig. 1), which marks the definitive onset of the northern hemisphere glaciation (lisiecki & raymo, 2005). the glacial triplet mis 100-mis 96, at about 2.5 ma, is testified globally by ice expansion in northern latitudes (raymo et al., 1989), changes in vegetation (the “tiglian”-“pretiglian” boundary of zagwijn, 1974, and the“arquatian” phase of lona, 1962; bertini, 2013), beginning of loess sedimentation in continental china (kukla & an, 1989), and migrations of terrestrial vertebrate faunas (the “elephant-equus event” in eurasia; lindsay et al., 1980; azzaroli et al., 1988, and references therein). the gauss/matuyama boundary (channell et al., 1992) is reported to occur about 1 m above the gssp, which provides a close approximation of the piacenzian/gelasian boundary globally. the 48 fig. 6 lithostratigraphy, magnetostratigraphy and calcareous plankton biostratigraphy of the gelasian type section at monte san nicola section. abundance fluctuations of globigerinoides ruber (on the right) are considered by the authors as a proxy for glacial/interglacial stages. modified from rio et al. (1998). capraro l., maiorano p. 49 fi g. 7 b io m ag ne to st ra tig ra ph ic c or re la tio n be tw ee n th e g el as ia n ty pe -s ec tio n (r io e t a l., 1 99 8) a nd th e “m an do rlo ” se ct io n (c ap ra ro e t a l., 2 02 2) a t m on te s an n ic ol a an d ot he r co ev al , sa pr op el -b ea rin g re fe re nc e se ct io ns in n or th er n ita ly ( m ar ec ch ia v al le y; r io e t a l., 1 99 6) , s ou th er n ita ly ( s in ga : l ou re ns e t a l., 1 99 2; v ric a: l ou re ns e t a l., 1 99 6b ) an d s ic ily ( p un ta p ic co la ; c as tra do ri et a l., 1 99 8) . c or re la tio n be tw ee n th e se ct io ns is p ro vi de d by k ey b io ho riz on s an d sa pr op el la ye rs o f c lu st er s o /m , a , b , c . p re ce ss io n cy cl es ( i-c yc le s) a re a ls o in di ca te d in br ac ke ts . in di vi du al s ap ro pe l la ye rs a re li nk ed t o th e as tro no m ic al t ar ge t cu rv es ( ec ce nt ric ity , pr ec es si on , an d su m m er in so la tio n at 6 5° n ) ca lc ul at ed f ro m t he l a0 4 or bi ta l s ol ut io n of la sk ar e t a l. (2 00 4) . a cr on ym s as in f ig ur e 1. m od ifi ed fr om c ap ra ro e t a l. (2 02 2) . italian gssps of the quaternary system boundary is also approximated by the last occurrence (lo) of nannofossil species discoaster pentaradiatus and d. surculus, which occur in the mediterranean in coincidence with oxygen isotopic stages 99 and 100, respectively (sprovieri et al., 1998) (fig. 1), ~80 k.y. above the base of the gelasian gssp (rio et al., 1998; sprovieri et al., 1998), by the lo of planktic foraminifer globorotalia bononiensis, which occurs in mis 96 (fig. 7), and by the repetitive influxes of neogloboquadrina atlantica in mis 96, 98 and 100 (lourens et al., 1992; becker et al., 2005) (fig. 8). the lo of the radiolarian species stichocorys peregrina (sanfilippo et al., 1985), the first occurrence (fo) of the diatom nitzschiajoussaea in low-latitude regions, and the lo of denticulopsis kamtschatica in the north pacific (barron, 1985) also approximate closely the gauss-matuyama reversal. 6.4. recent advancements becker et al. (2005) performed a high-resolution characterization of the glacial mis 100 at monte san nicola, although they employed a different stratigraphic 50 fig. 8 the stratigraphy studied by becker et al. (2005) at monte san nicola, with indication of individual sapropels of sapropel clusters a and b. sapropels are correlated with singa section and with the la04(1,1) 65°n summer insolation curve. marine isotope stages (mis) 110, 108 and 100–96 are indicated by peak occurrences of neogloboquadrina atlantica (green shaded) at singa. the atnts2004 shows the sapropel occurrences and stages in relation to the la04(1,1) 65°n summer insolation curve. the shaded area indicates the interval of mis101-95. the profile of relevance develops close to the “mandorlo” section of capraro et al. (2022). modified form becker et al. (2005). capraro l., maiorano p. section than the classical gssp profile. their results demonstrate that mis 100 was characterized by a highfrequency climatic variability in the sub-milankovian time domain of 5-8 kyr/cycle, reminiscent of the heinrich and dansgaard-oeschger events of the late pleistocene (dansgaard et al., 1993; heinrich, 1988; mayewski et al., 1997). herbert et al. (2015: 2018) reconstructed a long alkenone-derived record of past sea-surface temperatures (ssts) in the central mediterranean (fig. 1) across the upper neogene and quaternary by splicing together data from the punta piccola, monte san nicola and vrica sections and the deep-sea records of odp sites 964 and 967 (fig. 1). their results indicate that the major and most consistent drop in central mediterranean ssts occurred at ca. 1.84 ma, very close to the traditional pliocene/pleistocene (i.e., gelasian/ calabrian) boundary. a long and severe cold episode took place in mis 78 (ca. 2.09 ma), correlative to the “first deep glaciations” of rohling et al. (2014), while the mis 100-mis 96 glacial interval at ca. 2.6 ma only appears as a short-lived transient cooling event (herbert et al., 2015; 2018) (fig. 1). the monte san nicola succession was investigated in its entirety by capraro et al. (2022), who produced an integrated study on physical stratigraphy, magnetostratigraphy, planktic foraminifera, calcareous nannofossils and cyclostratigraphy from a stratigraphic section adjacent to that of becker et al. (2005). this study better constrained the position of the gauss/matuyama geomagnetic reversal above the “nicola bed” and demonstrated that the monte san nicola stratigraphy spans continuously from the top of the piacenzian stage to the base of the calabrian, without significant stratigraphic gaps and tectonic disturbances (fig. 7). accordingly, the monte san nicola area is deemed suitable to host the unit stratotype of the gelasian, or possibly its astronomical unit stratotype. on the contrary, they report on the presence of major faults and joints in the middle part of the historical “type” section, which do not affect the gssp itself but prevent achieving a continuous, undisturbed record in the stratigraphy above. currently, an international scientific program sponsored by inqua-saccom, gelstrat (https://www.inqua.nl/qp33.pdf)) is detailing the stratigraphic interval encompassing the gelasian gssp in its type locality, in order to achieve an integrated high (centennial to millennial-scale) resolution stratigraphic/ paleoclimatic record across the neogene/quaternary transition. 7. the calabrian stage the name “calabrian” was first introduced in a geological sense by french stratigrapher m. gignoux in 1910, for indicating the younger part of the pliocene series. in his seminal work “les formations marines pliocènes et quaternaires de l'italie du sud et de la sicile” (1913), he proposed as reference section for the calabrian the stratigraphy exposed at santa maria di catanzaro (ionian calabria; fig. 3): “au monte s. maria, le plateau culminant du point 207 est occupè par des marnes blanches qui recouvrent ce banc à cyprina islandica: ce fait est intéressant à noter, car il nous montre d'abord que l'apparition de ce banc est due à une modification de la sedimentation et de la population organique et non à une émersion; et ensuite, il nous prouve que le facies argileux a persisté jusqu'après le début du calabrien: la continuité de sédimentation qui relie le pliocène ancien au calabrien est donc ici bien manifeste”. for a long time, the santa maria di catanzaro section was acknowledged as the type-section of the calabrian stage, the base of which was pinned in correspondence to a fossiliferous sand bed rich in the bivalve arctica islandica (the notorious “gg bed”) (banner & blow, 1965; selli, 1967; bayliss, 1969; smith, 1969; bandy & wilcoxon, 1970; selli, 1970; berggren, 1971). sprovieri et al. (1973) demonstrated that the section harbors a major hiatus, as the shallow-water “gg bed” is transgressive on deep-marine pliocene marls and should instead be referred to the “sicilian” stage of doderlein (1872). therefore, the santa maria di catanzaro succession was deemed unfit as the typesection for the pliocene/pleistocene boundary. as a replacement, (emiliani et al., 1961) proposed to define the base of the pleistocene in the le castella section (crotone basin, ionian calabria; fig. 3), in correspondence to the so-called “marker bed” where the fo of the “cold guest” hyalinea baltica was detected. although the proposal was recognized by some (e.g., berggren & van couvering, 1974; haq et al., 1977), others argued that the section was affected by severe stratigraphic problems, above all a major hiatus immediately below the “marker bed” (ruggieri & sprovieri, 1977; colalongo et al., 1980; raffi & rio, 1980; rio et al., 1996a). later, ruggieri & sprovieri (1979) suggested replacing the calabrian stage with the selinuntian, a superstage including the santernian (ruggieri & sprovieri, 1975), the emilian (ruggieri & selli, 1949) and the sicilian of doderlein (1872) (fig. 6). however, vai (1996, 1997) objected that these units could not be employed formally, as none of them had ever been defined following the required ics procedures (hedberg, 1976; cowie et al., 1986; remane et al., 1996). further uncertainty arose from the lack of agreement on the main guiding criterion to be employed for establishing the neogene/quaternary boundary. after years of work, the iugs/unesco international geological correlation programme 41 (1974-1984) concurred in defining the boundary close to the top of olduvai event (ca. 1.8 ma), in keeping with the traditional definition of pliocene/pleistocene boundary in use globally within the marine stratigraphers community (e.g., glass et al., 1967; phillips et al., 1968; bandy & wilcoxon, 1970). selli et al. (1977) suggested to establish the neogene/quaternary boundary in the open-marine vrica composite section (crotone basin, calabria), which met the request by the international scientific community to define the boundary in a marine italian section in correspondence with the first immigration of “northern guests” in the mediterranean. the proposal was accepted by inqua in 1982, approved by ics in 1983, and finally ratified by iugs in 1984. still, the official documents made no mention of the status of the calabrian stage, and the most cited papers in the literature (aguirre & pasini, 1985, and bassett, 1985) made refer 51 italian gssps of the quaternary system ence to the vrica gssp as the pliocene/pleistocene boundary stratotype only. despite the numerous studies performed on the vrica section in the following decades (e.g., howell et al., 1990; hilgen, 1991a; azzaroli et al., 1996; rio et al., 1996a; lourens et al., 1996a,b), the calabrian remained undefined and its use declined, with the exception of stratigraphers working on italian sections. cita et al. (2006, 2008) addressed the problem of quaternary stages not yet formally established, and proposed pinning the gssp of the calabrian stage at vrica in correspondence to the traditional pliocene/ pleistocene boundary at ca. 1.8 ma. the proposal was accepted by the competent bodies, and the calabrian was ratified as the second stage of the newly established “long” lower pleistocene, immediately above the gelasian (cita et al., 2012). 7.1. the vrica section the vrica section (aguirre & pasini, 1985; pasini & colalongo, 1982) is located ca. 4 km south of the city of crotone (fig. 5a), not far from the reference sections of le castella (ca. 20 km) and santa maria di catanzaro (ca. 50 km) (fig. 3). it is part of the emerged part of the crotone sedimentary basin (roda, 1964), which offers one of the most expanded, complete, and well-exposed neogene and quaternary stratigraphic successions available globally. the crotone basin is a forearc basin of the ionian arc-trench system, which was generated by eastward rollback of a west-dipping subduction zone associated with extension in the tyrrhenian back arc basin (e.g., malinverno & ryan, 1986; kastens et al., 1988; mazzoli & helman, 1994; sartori, 1989; faccenna et al., 2001). it accommodates a sedimentary infill consisting of >3000 m of terrigenous clastics, primarily yielded by crystalline rock sources of the sila massif. the stratigraphic architecture of the crotone basin is very complex, being the result of a strong interplay between sedimentation, tectonics, eustasy and climate (e.g., rio et al., 1996b; massari et al., 2007, 2010). in particular, the vibrant geodynamical processes associated to the evolution of the calabrian arc triggered the formation of smaller sub-basins within the main crotone basin, with the development on very short distances of stratigraphic successions that differ dramatically in age and physical stratigraphy (e.g., massari et al., 2010). the vrica section consists of an expanded succession of blue hemipelagic marly clays that are spectacularly exposed within a suite of steep badlands immediately inland from the ionian coast (fig. 5b-e), between the town of crotone and the capo colonna archeological site. the succession belongs to the upper part of the “argilla marnosa di cutro” of roda (1964), a very thick package of piacenzian to calabrian open-marine sediments that, although with variable facies and age, constitutes the most widespread and exposed unit within the crotone basin. the stratigraphy including the vrica section was singled out by emiliani et al. (1961) as “papanice formation”, being characterized by the occurrence of tripolacean (laminitic) intervals that are absent in the underlying massive marly clays of the “semaforo formation”. the vrica composite section was reconstructed by splicing together three segments 52 (vrica a; vrica b, housing the calabrian gssp; and vrica c) (fig. 5c) that can be confidently linked by means of prominent marker beds and biohorizons (hilgen, 1990). correlation between the component segments is secured by the lack of tectonic disturbances, as the local succession forms a regular monocline dipping gently (5-15°) westward. as a whole, the vrica section extends for a total thickness of ca. 300 m (fig. 9) and allows for extremely high-resolution investigations, being characterized by sediment accumulation rates in the order of 30 cm/kyr (rio et al., 1996a) that increase to >40 cm/kyr in the lowermost part of the succession (suc et al., 2010). faunal constraints suggest that the vrica sediments were laid in an epibathyal setting at a water depth between 500 and 800 m (pasini & colalongo, 1994). in keeping with many of the outcrops exposed along the modern coastline of the crotone basin, the open-marine stratigraphy does not extend above the “large” gephyrocapsa zone of rio et al. (1990) (pasini & colalongo, 1994), being truncated by a flight of middle to upper pleistocene marine terraces. further inland, the younger part of the “argilla marnosa di cutro” (“small” gephyrocapsa zone of rio et al., 1990) is preserved as a stack of unconformity-bounded transgressive-regressive cycles, and locally overlain by regressive middle pleistocene outer shelf to fluvial sediments (rio et al., 1996b; massari et al., 2010; capraro et al., 2011, 2015, 2017). one of the most impressive features of the vrica section is the number and individual thickness of sapropelic layers preserved within. they are represented in the field by laminated intervals of organic-rich silts up to 3 m thick (fig. 5b, e), locally rich in fossil fish remains, that stand out in the local stratigraphy because of their orange color and different competence with respect to the embedding clays (raffi & thunell, 1996). in the vrica record, 14 mprs layers have been identified that allowed for an astronomical calibration of the section, demonstrating that the section extends continuously from 1.81 to 1.21 ma (lourens et al., 1996b, 1998). sparse thin sandy layers and three widely traceable tephra can be also employed as marker beds for intrabasinal correlation. in terms of calcareous plankton biostratigraphy, the composite section ranges from the uppermost planktonic foraminifera zone mpl5b to the g. truncatulinoides excelsa zone (cita, 1975, emended), and from calcareous nannofossil zone mnn 18 (pars) to mnn19e of rio et al. (1990). the calabrian portion of the section extends from mis 65 to mis 37 (lourens et al., 1996b) (fig. 10). the local stratigraphy of the section compares very well with that exposed in the coeval singa section, located further south along the coast of ionian calabria (zijderveld et al., 1991). likewise, the sapropel record at vrica is in excellent agreement with that found in the upper part of the monte san nicola section, where the gelasian/calabrian boundary can be easily identified (capraro et al., 2022). 7.2. previous studies during the 1980s and the 1990s, the vrica section was subjected to numerous investigations performed by international working groups in the light of both its criti capraro l., maiorano p. fi g. 9 s tra tig ra ph y of t he “ hi st or ic al ” v ric a se ct io n, w ith d is tri bu tio n of s ig ni fic an t m ic ro fo ss il ta xa a nd c on fli ct in g m ag ne to st ra tig ra ph ic r ec or ds . m od ifi ed f ro m p as in i & c ol al on go (1 99 7) a nd c ita e t a l. (2 01 2) . 53 italian gssps of the quaternary system cal role as the reference record for the neogene/ quaternary boundary and the advances made in astrocyclostratigraphy, which required suitable sections for establishing the new ats (hilgen, 1991a; lourens et al., 1996a, 1998). tauxe et al. (1983) achieved the first paleomagnetic record of the olduvai subchron (fig. 9), which provided a key criterion for pinning down the pliocene/pleistocene boundary. successive studies (zijderveld, 1991; nakagawa, 1997; roberts, 2010) (fig. 9) produced conflicting paleomagnetic records, suggesting that the stratigraphy around the calabrian gssp, where the top of the olduvai is expected to occur, is affected by severe remagnetization processes that prevent reconstructing a reliable paleomagnetic record at vrica. despite this major concern, the section offers a wide array of integrated biostratigraphic and physical stratigraphic constraints that allow for a safe and easy recognition of the gelasian/calabrian boundary, as summarized in the dedicated volume edited by van couvering (1996) to which we refer for further information. 7.3. definition of the calabrian gssp the calabrian gssp (cita et al., 2012) is located at the very base of the marl bed immediately overlying the very prominent sapropel e of aguirre & pasini (1985), located in the middle part of the component segment b of the vrica section. the astronomically calibrated age of the boundary is 1.806 ma (lourens et al., 1996). according to the original definition for the neogene/quaternary boundary, the base-calabrian is closely approximated by the top of the olduvai subchron (aguirre & pasini, 1985) (fig. 1). this event is generally recognized at about 8 m above sapropel e (hilgen, 1991a; zijderveld et al., 1991; roberts et al., 2010), although the section is not suitable for detailed paleomagnetic investigations (roberts et al., 2010). biostratigraphic markers of the boundary include, for the calcareous nannofossils, the lo of discoaster brouweri, documented at ca. 70 m below the gssp (~210 kyr prior to the boundary, assuming an average sediment accumulation rates of 30 cm/kyr) (fig. 10), and more importantly the fo of medium-sized gephyrocapsa (including g. oceanica), which occurs ca. 26 m (~78 kyr) above the fig. 10 astronomical calibration, oxygen isotope chronology and bioevents at vrica-crotone section according to the continuous age model of lourens et al. (1996a). fo: first occurrence; lo: last occurrence; fco: first common occurrence; reap.: reappearance; disap.: disappearance: l.c.: left coiled. lithostratigraphy from selli et al. (1977), zijderveld et al. (1991), lourens et al. (1996). magnetostratigraphy from zijderveld et al. (1991). astronomical time scale (atnts2004) from lourens et al. (2004). summer insolation 65°n (la041:1) from laskar et al. (2004). modified from maiorano et al. (2010). 54 capraro l., maiorano p. boundary (fig. 10). planktonic foraminiferal events include the first common occurence (fco) of left-coiling neogloboquadrina pachyderma, at ca. 3 m (~9 kyr) above the gssp, and the fo of globigerinoides tenellus (fig. 9), at ca. 28 m (~84 kyr) above the boundary. these key markers are complemented by numerous less prominent yet sharp biohorizons, as shown in cita et al. (2008, 2012) and figures 9-10. a synthesis of the main correlation criteria for the calabrian gssp is reported in table 4. 7.4. recent advancements in the last years, the vrica section has not been a major topic for the geological community. exceptions are the work of roberts et al. (2010), who confirmed the poor paleomagnetic properties of the section in the interval straddling the olduvai subchron, and that of herbert et al. (2015), who emphasized that the major and more persistent drop in mediterranean ssts after the onset of the northern hemisphere glaciation occurred around the gelasian/calabrian boundary (ca. 1.8 ma) (fig. 1). 8. summary the italian neogene and quaternary marine sedimentary record played a critical role in the development of innovative stratigraphic tools and the definition of chronostratigraphic standards. among the numerous advancements achieved via the investigation of mediterranean sections, it is worth mentioning the ats for the neogene and the quaternary, which was largely constructed and validated on sections exposed in peninsular italy and sicily. in particular, they include the gssp sections of the zanclean and piacenzian stages (lower and upper pliocene, respectively) and those of the gelasian and calabrian stages (lower pleistocene). the latter two are of particular interest for those working in the quaternary, as they represent the past and present global reference stratigraphic records for the beginning of the pleistocene. all these sedimentary records contain multiple biotic and abiotic stratigraphic constraints that allow exporting the relevant gssps well beyond their type localities. this further confirms the key contribution given by the italian sedimentary record in defining chronostratigraphic standards of use at a global scale. acknowledgements the authors thank the editor ilaria mazzini and two anonymous reviewers for improving the first version of the manuscript. the contribution of the many researchers who have greatly contributed over the years to the progress of the italian quaternary stratigraphy is also acknowledged. references aguirre e., pasini g. (1985) the pliocene-pleistocene boundary. episodes, 8, 116-120. arduino g. (1760) due lettere del sig. giovanni arduino sopra varie sue osservazioni naurali. nuova raccolta d’opuscoli scientifici e filologici, 6, pp. 180. aubry m.p., berggren w.a., van couvering j.d., steininger f. (1999) problems in chronostratigraphy: stages, series, unit and boundary stratotypes, global stratotype section and point and tarnished golden spikes. earth sci. rev., 46, 99148. azzaroli a., colalongo m.l., nakagawa h., pasini g., rio d., ruggieri g., sartoni s., sprovieri r. (1996) the pliocene-pleistocene boundary in italy. in: van couvering j. (ed.), the pliocene-pleistocene boundary: definition and worlwide correlation, 141-155. cambridge university press. bandy o.l., wilcoxon j.a. (1970) the pliocenepleistocene boundary, italy and california. geol. soc. am. bull., 81, 2939-2948. banner f.t., blow w.h. (1965) progress in the planktonic foraminiferal biostratigraphy of the neogene. nature, 207, 13-51. barbieri f. (1967) the foraminifera in the pliocene section vernasca castell’arquato including the tab. 4 definitions for the gelasian and calabrian gssps and relevant chronostratigraphic markers. fo: first occurrence; lo: last occurrence; fco: first common occurrence. 55 italian gssps of the quaternary system “piacenzian stratotype”. soc. it. sc. nat. mus. civ. sc. nat. milano, mem., 15, 145-163. barron j., nigrini c.a., poujos a., saito t., theyer r., thomas e., weinrich n. (1985) synthesis of biostratigraphy, central equatorial pacific, deep sea drilling project leg 85: refinement of oligocene to quaternary biochronology. in: l. mayer, f. theyer, et al. (eds.), in. rep. dsdp, 85, 905-934. bassett m.g. (1985) towards a "common language" in stratigraphy. episodes, 8, 87-92. bayliss d. (1969) the distribution of hyalinea baltica and globorotalia truncatulinoides in the type calabrian. lethaia, 2, 133-143. becker j., lourens l.j., hilgen f.j., van der laan e., kouwenhoven t.j., reichart g.-j. (2005) late pliocene climate variability on milankovitch to millennial time scales: a high-resolution study of mis100 from the mediterranean. palaeogeogr. palaeoclim. palaeoecol., 228, 338-360. beneo e. (1958) sull’olistostroma quaternario di gela (sicilia meridionale). boll. serv. geol. d’it., 79, 515. berggren w.a. (1971) tertiary boundaries and correlations. in: funnell r.m.s., riedel w.r. (eds.), the micropaleontology of oceans, 693-809. cambridge university press. berggren w.a., kent d.v., flynn j.j., van couvering j.a. (1985) cenozoic geochronology. geol. soc. am. bull., 96, 1407-1418. berggren w.a., van couvering j.a. (1974) the late neogene. elsevier, netherlands. berggren w.a., kent d.v., swisher c.c., aubry m.-p. (1995) a revised cenozoic geochronology and chronostratigraphy. sepm spec. publ., 54, 129212. bertini a. (2013) climate and vegetation in the upper valdarno basin (central italy) as a response to northern hemisphere insolation forcing and regional tectonics in the late pliocene-early pleistocene. it. j. geosci., 132, 137-148. bertoldi r., rio d., thunell r. (1989) pliocenepleistocene vegetational and climatic evolution of the south-central mediterranean: palaeogeogr. palaeoclim. palaeoecol., 72, 263-275. bonaduce g., sprovieri r. (1984) the appearance of cytheropteron testudo sars (crustacea: ostracoda) is a pliocene event. evidence from a sicilian sequence (italy). boll. soc. paleontol. ital., 23, 131 -136. breggren w.a., kent d.v., swisher c.c., aubry m.p. (1995) a revised cenozoic geochronology and chronostratigraphy. sepm special publication, 54, 129-212. capraro l., bonomo s., di stefano a., ferretti p., fornaciari e., galeotti s., incarbona a., macrì p., raffi i., sabatino n., speranza f., sprovieri m. (2022) the monte san nicola section (sicily) revisited: a potential unit-stratotype of the gelasian stage. quat. sci. rev., 278, 1-18. capraro l., ferretti p., macrì p., scarponi d., tateo f., fornaciari e., bellini g., dalan g. (2017) the valle di manche section (calabria, southern italy): a high resolution record of the early-middle pleistocene transition (mis 21-mis 19) in the central mediterranean. quat. sci. rev., 165, 31-48. capraro l., macrì p., scarponi d., rio d. (2015) the lower to middle pleistocene valle di manche section (calabria, southern italy): state of the art and current advances. quat. int., 383, 36-46. capraro l., massari f., rio d., fornaciari e., backman j., channell j.e.t., macrì p., prosser g., speranza f. (2011) chronology of the lower-middle pleistocene succession of the south-western part of the crotone basin (calabria, southern italy). quat. sci. rev., 30, 1185-1200. castradori d., rio d., hilgen f.j., lourens l.j. (1998) the global standard stratotype-section and point (gssp) of the piacenzian stage (middle pliocene). episodes, 21, 88-93. catalano r., channell j.e.t., d’argenio b., napoleone g. (1977) mesozoic paleogeography of the southern appennines and sicily. problems of paleotectonics and paleomagnetism. mem. soc. geol. ital., 15, 95-118. catalano r., valenti v., albanese c., accaino f., sulli a., tinivella u., giustiniani m. (2013) sicily’s foldthrust belt and slab roll-back: the si.ri.pro. seismic crustal transect. j. geol. soc., 170, 451-464. channell j.e.t., di stefano e., sprovieri r. (1992) calcareous plankton biostratigraphy, magnetostratigraphy and paleoclimatic history of the pliopleistocene monte san nicola section (southern sicily). boll. soc. paleont. it., 31, 351-382. ciaranfi n., lirer f., lirer l., lourens l.j., maiorano p., marino m., petrosino p., sprovieri m., stefanelli s., brilli m., girone a., joannin s., pelosi n., vallefuoco m. (2010) integrated stratigraphy and astronomical tuning of lower-middle pleistocene montalbano jonico section (southern italy). quat. int., 219, 109-120. cita m.b., gartner s. (1973) the stratotype zanclean foraminiferal and nannofossil biostratigraphy. riv. ital. paleontol., 79, 503-558. cita m.b. (1973) pliocene stratigraphy and chronostratigraphy in: ryan w.b.f., hsu k.j., et al., init. rep. of the dsdp, 13, 1343-1379. cita m.b. (1975) planktonic foraminiferal biozonation of the mediterranean pliocene deep sea record. a revision. riv. it. paleont. strat., 81, 527-544. cita m.b., capraro l., ciaranfi n., di stefano e., lirer f., maiorano p., marino m., raffi i., rio d., sprovieri r., stefanelli s., vai g.b. (2008) the calabrian stage redefined. episodes, 31, 408-419. cita m.b., capraro l., ciaranfi n., di stefano e., marino m., rio d., sprovieri r., vai g.b. (2006) calabrian and ionian: a proposal for the definition of mediterranean stages for the lower and middle pleistocene. episodes, 29, 107-114. cita m.b., castradori d. (1995) rapporto sul workshop “marine sections from the gulf of taranto (southern italy) usable as potential stratotypes for gssp of the lower, middle and upper pleistocene”. boll. soc. geol. it., 114, 319-336. cita m.b., gibbard p.l., head m.j., and the ics sub 56 capraro l., maiorano p. commission on quaternary stratigraphy (2012) formal ratification of the gssp for the base of the calabrian stage (second stage of the pleistocene series, quaternary system). episodes, 35, 388397. colalongo m.l., pasini, g., sartoni s. (1980) neogene -quaternario e definizione del relativo stratotipo. paleontologia stratigrafica ed evoluzione, 1, 9194. cowie j.w. (1986) guidelines for boundary stratotypes. episodes, 9(2), 78-82. dansgaard w., johnsen s.j., clausen h.b., dahljensen d., gundestrup n.s., hammer c.u., hvidberg c.s., steffensen j.p., sveinbjornsdottir a.e., jouzel j. (1993) evidence for general instability of paste climate from a 250-kyr ice-core record. nature, 364, 218-220. de visser j.p., ebbing j.h.j., gudjonsson l., hilgen f.j., jorissen f.j., verhallen p.j.j.m., zevenboom d. (1989) the origin of rhythmic bedding in the pliocene trubi formation of sicily, southern italy. palaeogeogr. palaeoclim. palaeoecol., 69, 45-66. di stefano e., sprovieri r., caruso a. (1993) high resolution biochronology in the monte narbone formation of the capo rossello section and the mediterranean first occurrence of globorotalia truncatulinoides. riv. it. paleont. strat., 99, 357370. doderlein p. (1872) note illustrative della carta geologica del modenese e del reggiano. memoria iii. driever b.w.m. (1988) calcareous nannofossil biostratigraphy and paleoenvironmental interpretation of the mediterranean pliocene. utrecht micropal. bull., 36. emiliani c., mayeda t., selli r. (1961) paleotemperature analysis of the plio-pleistocene section at le castella, calabria, southern italy. geol. soc. am. bull., 72, 679-688. faccenna c., becker t.w., lucente f.p., jolivet l., rossetti f. (2001) history of subduction and back -arc extension in the central mediterranean. geophys. j. int., 145, 809-820. gasparo morticelli m., valenti v., catalano r., sulli a., agate m., avellone g., albanese c., basilone l., gugliotta c. (2015) deep controls on foreland basin system evolution along the sicilian fold and thrust belt. bulletin de la societé géologique de france, 186, 273-290. ghisetti f., gorman a.r., grasso m., vezzani l. (2009) imprint of foreland structure on the deformation of a thrust sheet: the plio-pleistocene gela nappe (southern sicily, italy). tectonics, 28, tc4015. gibbard p.l., head m.j. (2010) the newly-ratified definition of the quaternary system/period and redefinition of the pleistocene series/epoch, and comparison of proposals advanced prior to formal ratification: episodes, 33, 152-158. gibbard p.l., head m.j., walker m.j.c., and the subcommission on quaternary stratigraphy (2010) formal ratification of the quaternary system/ period and the pleistocene series/epoch with a base at 2.58 ma. j. quat. sci., 25, 96-102. gignoux m. (1910) sur la classification du pliocène et du quaternarie dans l'italie du sud. comptes rendus de l'academie des sciences, 150, 841-844. gignoux m. (1913) les formations marine pliocènes et quaternaires dans italie du sud et la sicile. annales université de lyon, 36, 1-633. giorgi f. (1996) climate modelling over the mediterranean region. in: guerzoni s., roy c. (eds.), the impact of desert dust across the mediterranean. kluwer, netherlands. glass b., ericson d.b., heezen b.c., opdyke n.d., glass j.a. (1967) geomagnetic reversals and pleistocene chronology. nature, 216, 437-442. lirer f., foresi l.m., iaccarino s.m., salvatorini g., turco e., cosentino c., sierro f.j., caruso a. (2019) mediterranean neogene planktonic foraminifer biozonation and biochronology. earthscience rev., 196, 102869. lourens l., hilgen f., shackleton n.j., laskar j., wilson d. (2004) the neogene period. in: gradstein f.m., ogg j.g., smith a.g. (eds.), a geological time scale, 409-440. cambridge university press. gradstein f.m., ogg j.g., schmitz m.d., ogg g.m. (2020) the geological time scale 2020. elsevier, netherlands. grasso m., manzoni m., quintili a. (1987) misure magnetiche sui trubi fm. infrapliocenici della sicilia orientale: possibili implicazioni stratigrafiche e strutturali, mem. soc. geol. it., 38, 459-474. haq b.u., berggren w.a., van couvering j.a. (1977) corrected age of the pliocene-pleistocene boundary. nature, 269, 483-488. harland w.b., cox a.v., llevellyn p.g., pickton c.a.g., smith a.g., walters r. (1982) a geologic time scale. cambridge university press, pp. 131. hedberg d.h. (1965) note 32. american commission on stratigraphic nomenclature definition of geologic systems. aapg bull., 49 (10), 1694-1703. hedberg d.h. (1976) international stratigraphic guide. a guide to stratigraphic classification, terminology and procedure. john wiley and sons, new york. heinrich h. (1988) origin and consequences of cycling ice rafting in the northeast atlantic ocean during the past 130,000 years. quat. res., 29, 143-152. heirtzler j.r., dickson g.o., herron e.m., pitman w.c., le pichon l.c. (1968) marine magnetic anomalies, geomagnetic field reversals and motion of the ocean floor and continents. j. geophys. res., 73, 2119-2136. herbert t.d., ng d., cleaveland peterson l. (2015) evolution of mediterranean sea surface temperatures 3.5-1.5 ma: regional and hemispheric influences. earth plan. sci. lett., 409, 307-318. herbert t.d., lawrence k.t., tzanova a., peterson l., c., caballero-gill r.p., kelly c.s. (2018) sst estimates as a function of age, mediterranean sites. pangaea doi: 10.1594/pangaea.885603. hilgen f.j. (1990) closing the gap in the pliopleistocene boundary stratotype sequence of crotone (southern italy). newsl. stratigr., 22, 43-51. 57 italian gssps of the quaternary system hilgen f.j. (1991a) extension of the astronomically calibrated (polarity) time scale to the miocene/ pliocene boundary. earth plan. sci. lett., 107, 349 -368. hilgen f.j. (1991b) astronomical calibration of gauss to matuyama sapropels in the mediterranean and implication for the geomagnetic polarity time scale. earth plan. sci. lett., 104, 226-244. hilgen f.j., abdul aziz h., krijgsman w., langereis c.g., lourens l.j., meulenkamp j.e., raffi i., steenbrink j., turco e., van vugt n., wijbrans j.r., zachariasse w.j. (1999) present status of the astronomical (polarity) time-scale for the mediterranean late neogene. phil. trans. r. soc. london, 357, 1931-1947. hilgen f.j., brinkhuis h., zachariasse w.j. (2006) unit stratotypes for global stages: the neogene perspective. earth sci. rev., 74, 113-125. hilgen f.j., krijgsman w., langereis c.g., lourens l.j. (1997) breakthrough made in dating of the geological record. eos, 78, 288-289. hilgen f.j., krijgsman w., langereis c.g., lourens l.j., santarelli a., zachariasse w.j. (1995) extending the astronomical (polarity) time scale into the miocene. earth planet. sci. lett., 136, 495510. hilgen f.j., lourens l.j., berger a., loutre m.f. (1993) evaluation of the astronomically calibrated time scale for the late pliocene and earliest pleistocene. paleoceanography, 8(5), 549-565. hilgen f.j., lourens l., pälike h., and research support team (2020) should unit-stratotypes and astrochronozones be formally defined? a dual proposal (including postscriptum). newsl. strat., 53, 19-39. holmes a. (1960) a revised geological time-scale. transactions of the geological society of edinburgh, 17, 183-216. howell m.h., rio d., thunell r. (1990) laminated sediments from the vrica section (calabria, southern italy): evidence for plio-pleistocene warming and cooling trends in the mediterranean region. palaeogeogr. palaeoclim. palaeoecol., 78, 195216. howell m.w., thunell r., tappa e., rio d., sprovieri r. (1988) late neogene laminated and opal-rich facies from the mediterranean region: geochemical evidence for mechanisms of formation. palaeogeogr. palaeoclim. palaeoecol., 64, 265-286. kastens k.a., mascle j., auroux c., bonatti e., broglia c., channell j.e.t., curzi p., emeis k.-c., glaçon g., hasegawa s., hieke w., mascle g., mccoy f., mckenzie j., mendelson j., müller c., réhault j.p., robertson a., sartori r., sprovieri r., torii m. (1988) odp leg 107 in the tyrrhenian sea: insights into passive margin and back-arc basin evolution. geol. soc. am. bull., 100, 1140-1156. krijgsman w. (2002) the mediterranean: mare nostrum of earth sciences. earth plan. sci. lett., 202, 1-12. kukla g., an z. (1989) loess stratigraphy in central china: palaeogeogr. palaeclim. palaeoecol., 72, 203-225. langereis c.g., hilgen f.j. (1991) the rossello composite: a mediterranean and global reference section for the early to early late pliocene. earth plan. sci. lett., 104, 211-225. laskar j. (1990) the chaotic motion of the solar system. icarus, 88, 266-291. laskar j., fienga a., gastineau j., manche h. (2011) la2010: a new orbital solution for the long-term motion of the earth. astronomy & astrophysics, 532, a89. laskar j., robutel p., joutel f., gastineau m., correia a.c.m., levrard b. (2004) a long-term numerical solution for the insolation quantities of the earth. astronomy & astrophysics, 428, 261-285. lentini f., carbone s., catalano s., grasso m., monaco c. (1991) presentazione della carta geologica della sicilia centro-orientale. mem. soc. geol. it., 47, 145-156. lentini f., carbone s. (2014) geologia della sicilia. ispra. memorie descrittive della carta geologica d’italia, 95, 7-414. lickorish w.h., grasso m., butler r.w., argnani a., maniscalco r. (1999) structural styles and regional tectonic setting of the “gela nappe” and frontal part of the maghrebian thrust belt in sicily. tectonics, 18, 655-668. lindsay e.h., opdyke n.d., johnson n.m. (1980) pliocene dispersal of the horse equus and late cenozoic mammalian dispersal event. nature, 287, 135 -138. lirer f., foresi l.m., iaccarino s.m., salvatorini g., turco e., cosentino c., sierro f.j, caruso a. (2019) mediterranean neogene planktonic foraminifer biozonation and biochronology. earthscience reviews, 196, 102869. lirer f., iaccarino s. (2011) mediterranean neogene historical stratotype sections and global stratotype section and point (gssp): state of the art. ann. naturhist. mus. wien, 113, 67-144. lisiecki l.e., raymo m.e. (2005) a pliocenepleistocene stack of 57 globally distributed benthic δ18o records. paleoceanography, 20, pa1003. lona f. (1962) prime analisi pollinologiche sui depositi terziari-quaternari di castell’arquato: reperti di vegetazione da clima freddo sotto le formazioni calcaree ad amphistegina. boll. soc. geol. it., 81, 89-91. lourens l.j., antonarakou a., hilgen f.j., van hoof a.a.m., vergnaud-grazzini c., zachariasse w. (1996a) evaluation of the plio-pleistocene astronomical timescale. paleoceanography, 11, 391413. lourens l.j., hilgen f.j., gudjonsson j., zachariasse w.j. (1992) late pliocene to early pleistocene astronomically-forced sea surface productivity and temperature variations in the mediterranean. mar. micropaleontol., 19, 49-78. lourens l.j., hilgen f.j., raffi i. (1998) base of large gephyrocapsa and astronomical calibration of early pleistocene sapropels in site 967 and hole 969d: solving the chronology of the vrica section (calabria, italy). in: robertson h.f., emeis k., 58 capraro l., maiorano p. richter c., et al. (eds.), proc. odp, sci. res., 160, 191-198. lourens l.j., hilgen f.j., raffi i., vergnaud-grazzini c. (1996b) early pleistocene chronology of the vrica section (calabria, italy). paleoceanography, 11, 797-812. lourens l.j., hilgen f.j., shackleton n.j., laskar j., wilson, d. (2004) the neogene period. in: gradstein f., ogg i., smith a. (eds.), a geological timescale 2004. cambridge univ. press, uk. lourens l.j., wehausen r., brumsack h.j. (2001) geological constraints on tidal dissipation and dynamical ellipticity of the earth over the past three million years. nature, 409, 1029-1032. lyell c. (1833) principles of geology, 3. j. murray eds., london. maiorano p., capotondi l., ciaranfi n., girone a., lirer f., marino m., pelosi n., petrosino p., piscitelli a. (2010) vrica-crotone and montalbano jonico sections: a potential unit-stratotype of the calabrian stage. episodes, 33, 218-233. malinverno a., ryan w.b.f. (1986) extension on the tyrrhenian sea and shortening in the apennines as result of arc migration driven by sinking of the lithosphere. tectonics, 5, 227-245. marino m., girone a., gallicchio s., herbert t., addante m., bazzicalupo p., quivelli o., bassinot f., bertini a., nomade s., ciaranfi n., maiorano p. (2020) climate variability during mis 20-18 as recorded by alkenone-sst and calcareous plankton in the ionian basin (central mediterranean). palaeogeogr. palaeclim. palaeoecol., 560, 110027. massari f., capraro l., rio d. (2007) climatic modulation of timing of systems-tract development with respect to sea-level changes (middle pleistocene of crotone, calabria, southern italy). j. sediment. res., 77, 461-468. massari f., prosser g., capraro l., fornaciari e., consolaro c. (2010) a revision of the stratigraphy and geology of the south-western part of the crotone basin (southern italy). ital. j. geosci., 129, 353-384. mayer-eymar k. (1858) versuch einer neuen klassification der tertiär gebilde europa's. verhandl. der allgemeinen schweiz. ges. f. gesammt. naturwissensch., trogen, 165-199. mayewski p.a., meeker l.d., twickler m.s., whitlow s., yang q., lyons w.b., prentice m (1997) major features and forcing of high-latitude northern hemisphere atmospheric circulation using a 110,000year-long glaciochemical series. j. geophys. res. oceans, 102(c12), 26345-26366. mazzoli s., helman m. (1994) neogene pattern of relative plate motion for africa-europe: some implications for recent central mediterranean tectonics. geol. rundsch., 83, 464-468. nakagawa h., niitsuma n., takayama t., matoba,y., oda m., tokunaga s., koizumi i. (1997) the magnetostratigraphy of the vrica section, italy, and its correlation with the plio-pleistocene of the boso peninsula, japan. in: van couvering j. (ed.), the pliocene-pleistocene boundary: definition and worlwide correlation, 46-56. cambridge university press. ogniben l. (1969) schema introduttivo alla geologia del confine calabro-lucano. mem. soc. geol. it., 8, 453-763. pareto m. (1865) sur les subdivisions que l’on pourrait établir dans les terraines tertiaires de l’apennin septentrional. bull. soc. géol. france, 22, 210277. pasini g., colalongo m.l. (1982) status of research on the vrica section (calabria, italy), the proposed neogene/quaternary boundary-stratotype section. report at xi inqua congress, 1-75. pitagoratecnoprint. pasini g., colalongo m.l. (1994) proposal for the erection of the santernian/emilian boundarystratotype (lower pliocene) and new data on the pliocene/pleistocene boundary-stratotype. boll. soc. paleont. it., 33, 101-120. phillips j.d., berggren w.a., bertels a., wall d. (1968) paleomagnetic stratigraphy and micropaleontology of three deep sea cores from the central north atlantic ocean. earth plan. sci. lett., 4, 118-130. pinter p.r., butler r.w.h., hartley a.j., maniscalco r., baldassini n., di stefano a. (2016) the numidian of sicily revisited: a thrust-influenced confined turbidite system. mar. petr. geol., 78, 291-311. pinter p.r., butler r.w.h., hartley a.j., maniscalco r., baldassini n., di stefano a. (2018) tracking sand-fairways through a deformed turbidite system: the numidian (miocene) of central sicily, italy. basin res., 30, 480-501. raffi i., rio d. (1980) nuove osservazioni sulla distribuzione del nannoplancton calcareo nella serie di le castella (calabria). paleontologia stratigrafica ed evoluzione, 1, 181-186. raffi i., thunell r. (1996) comparison of the laminated units at vrica and deep-sea sapropels from the eastern mediterranean. in: van couvering, j. (ed.), the pliocene-pleistocene boundary: definition and worlwide correlation, 57-62. cambridge university press. raffi s., rio d., sprovieri r., valleri g., monegatti p., raffi i., barrier p. (1989) new stratigraphic data on the piacenzian stratotype: boll. soc. geol. it., 108, 183-196. raymo m.e., ruddiman w.f., backman j., clement b.m., martinson d.g. (1989) late pliocene variation in northern hemisphere ice sheets and north atlantic deep-water circulation. paleoceanography, 4, 413-446. remane j., bassett m.g., cowie j.w., gohrbandt k.h., lane h.r., michelsen o., naiwen w.(1996) revised guidelines for the establishment of global chronostratigraphic standards by the international commission on stratigraphy (ics). episodes, 19, 77-81. rio d., backman j., raffi i. (1996a) calcareous nannofossil biochronology and the pliocenepleistocene boundary. in: van couvering, j. (ed.), the pliocene-pleistocene boundary: definition and worlwide correlation, 63-78. cambridge university 59 italian gssps of the quaternary system press. rio d., channell j.e.t., massari f., poli m.s., sgavetti m., d'alessandro a., prosser g. (1996b) reading pleistocene eustasy in a tectonically active siliciclastic shelf setting (crotone peninsula, southern italy). geology, 24, 743-746. rio d., channel j.e.t., bertoldi r., poli m.s., vergerio p.p., raffi i., sprovieri r., thunell r.c. (1997) pliocene sapropels in the northern adriatic area: chronology and paleoenvironmental significance. palaeogeogr. palaeoclim. palaeoecol., 135, 1-25. rio d., premoli silva i., capraro l. (2004) the geologic time scale and the italian stratigraphic record. episodes, 26, 259-263. rio d., raffi i., villa g. (1990) pliocene-pleistocene calcareous nannofossil distribution patterns in the western mediterranean. in: kastens k.a., mascle j., et al. (eds.), proc. odp, sci. results, 107, college station, tx (ocean drilling program), 513533. rio d., sprovieri r., castradori d., di stefano e. (1998) the gelasian stage (upper pliocene): a new unit of the global standard chronostratigraphic scale. episodes, 91, 82-87. rio d., sprovieri r., di stefano e. (1994) the gelasian stage: a proposal of a new chronostratigraphic unit of the pliocene series. riv. ital. paleontol. stratigr., 100, 103-124. rio d., sprovieri r., raffi i. (1984) calcareous plankton stratigraphy and biochronology of the pliocene -lower pleistocene succession of the capo rossello area, sicily. mar. micropaleontol. 9, 135-180. rio d., sprovieri r., raffi i., valleri g. (1988) biostratigrafia e paleoecologia della sezione stratotipica del piacenziano. boll. soc. geol. ital. 27, 213-238. rio d., sprovieri r., thunell r. (1991) pliocene-lower pleistocene chronostratigraphy: a re-evaluation of mediterranean type sections. geol. soc. am. bull., 103, 1049-1058. roberts a.p., florindo f., larrasoaña j.c., o'regan m.a., zhao x. (2010) complex polarity pattern at the former plio-pleistocene global stratotype section at vrica (italy): remagnetization by magnetic iron sulphides. earth planet. sci. lett., 292, 98111. roda c. (1964) distribuzione e facies dei sedimenti neogenici nel bacino crotonese. geol. romana, 3, 319-366. rohling e., foster g., grant k., marino g., roberts a.p., tamisiea m.e., williams f. (2014) sea-level and deep-sea-temperature variability over the past 5.3 million years. nature, 508, 477-482. rohling e.j., marino g., grant k.m. (2015) mediterranean climate and oceanography, and the periodic development of anoxic events (sapropels). earth sci. rev., 143, 62-97. ruggieri g., selli r. (1949) il pliocene ed il post pliocene dell'emilia. giornale di geologia, 20, 1-14. ruggieri g., sprovieri r. (1975) la definizione dello stratotipo del piano siciliano e le sue conseguenze. riv. miner. siciliana, 26, 151-153. ruggieri g., sprovieri r. (1977) ricerche sul siciliano di palermo: le argille del fiume oreto. boll. soc. geol. it., 94, 1613-1622. ruggieri g., sprovieri r. (1979) selinuntiano, nuovo superpiano per il pleistocene inferiore. boll. soc. geol. it., 96, 797-802. salvador a. (1994) international stratigraphic guide, 2nd edition. geol. soc. am., usa. sanfilippo a., westberg-smith m.j., riedel w.r. (1985) cenozoic radiolaria. in: bolli h.m., saunders j.b., perch-nielsen k. (eds.), plankton stratigraphy, 631-712. cambridge university press. sartori r. (1989) evoluzione neogenico-recente del bacino tirrenico e i suoi rapporti con la geologia delle aree circostanti. giorn. geol., 51, 1-39. selli r. (1967) the plio-pleistocene boundary in italian marine sections and its relationship to continental stratigraphies. progress in oceanography, 4, 6787. selli r. (1970) calabrian. giornale di geologia, 37, 5564. selli r., accorsi c.a., bandini mazzanti m., bertolani marchetti d., bonadonna f.p., borsetti a.m., cati f., colalongo m.l., d'onofrio s., landini w., menesini e., mezzetti r., pasini g., savelli g., tampieri r. (1977) the vrica section (calabria). a potential neogene/quaternary boundary stratotype. giornale di geologia, 41, 181-204. shackleton n.j., backman j., zimmerman h.t., kent d.v., hall m.a., roberts d.g., westberg-smith j. (1984) oxygen isotope calibration of the onset of ice-rafting and history of glaciation in the north atlantic region. nature, 307, 620-623. shackleton n.j., berger a., peltier w.r. (1990) an alternative astronomical calibration of the lower pleistocene timescale based on odp site 677. trans. r. soc. edinb. earth sci., 81, 251-261. smith l.a. (1969) pleistocene discoaster at the stratotype of the calabrian stage (santa maria di catanzaro) and le castella, italy. gulf coast association geological society trans., 19, 579-583. smith w. (1816) strata identified by organized fossils. w. arding, london. snelling n.j. (1985) the chronology of the geological record. the geological society, blackwell scientific publications, pp. 343. spaak p. (1983) accuracy in correlation and ecological aspects of the planktonic foraminiferal zonation of the mediterranean pliocene. utrecht micropaleontol. bull., 28, 1-159. sprovieri r. (1992) mediterranean pliocene biochronology: a high-resolution record based on quantitative planktonic foraminifera distribution: riv. it. paleont. strat., 98, 61-100. sprovieri r., d'agostino s., di stefano e. (1973) giacitura del calabriano nei dintorni di catanzaro. riv. it. paleont., 79, 127-140. sprovieri r., di stefano e., howell m., sakamoto t., di stefano a., marino m. (1998) integrated calcareous plankton biostratigraphy and cyclostratigraphy at site 964. in: robertson a.h.f., emeis k.-c., richter c., camerlenghi a. (eds.), proc. odp, sci. results, 160, college station, tx (ocean drilling 60 capraro l., maiorano p. program), 155-165. sprovieri r., thunell r., howell m. (1986) paleontological and geochemical analysis of three laminated sedimentary units of late plioceneearly pleistocene age from the monte san nicola section in sicily: riv. it. paleont. strat., 92, 401-434. steno n. (1669) de solido intra solidum naturaliter contento dissertationis prodromus. stella, florence. suc j.-p., combourieu-nebout n., seret g., popescu s.a., klotz s., gautier f., clauzon g., westgate j., insinga d., sandhu a.s. (2010) the crotone series: a synthesis and new data. quat. int., 219, 121-133. tauxe l., opdyke n.d., pasini g.c., elmi c. (1983) age of the plio-pleistocene boundary in the vrica section, southern italy. nature, 304, 125-129. vai g.b. (1996) revisione critico-storica dei piani marini del quaternario. servizio geologico italiano, miscellanea, vi. vai g.b. (1997) twisting or stable quaternary boundary? a perspective on the glacial late pliocene concept. quat. int., 40, 11-22. van couvering j.a., castradori d., cita m.b., hilgen f. j., rio d. (2000) the base of the zanclean stage and of the pliocene series. episodes, 23, 179-187. verhallen p.j.j.m. (1987) early development of bulimina marginata in relation to paleoenvironmental changes in the mediterranean: proc. ned. akad. wet., 90,161-180. zagwijn w.h. (1974) the pliocene-pleistocene boundary in western and southern europe. boreas, 3, 75 -97. zijderveld j.d.a, hilgen f.j., langereis c.g., verhallen p.j.j.m., zachariasse w.j. (1991) integrated magnetostratigraphy and biostratigraphy of the upper pliocene-lower pleistocene from the monte singa and crotone areas in calabria (italy). earth planet. sci. lett., 107, 697-714. 61 ms. received: december 7, 2022 revised: february 22, 2023 accepted: february 3, 2023 avaiable online: march 2, 2023 italian gssps of the quaternary system 62 ojs547 d'arpa incarbona def.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 35 (1), 2022, 69-83 1. introduction ostracods are small aquatic crustaceans equipped with low-magnesium calcite bivalved shells. ostracods are commonly preserved in neogene and quaternary sediments. though their adoption as paleoenvironmental proxies is largely overlooked, ostracods have an excellent potential, in marine environments, in comparison to other microfossil groups, mostly for paleobathymetry and bottom water conditions reconstruction (holmes & chivas, 2002). the middle pleistocene transition (1.2-0.7 ma) is a significant re-organization of the climate system, in terms of glacial/interglacial cycles duration, co2 levels drop, sea surface temperature cooling in the oceans, atlantic ocean circulation and monsoon activity weakening (lisiecki & raymo, 2005; clark et al., 2006; martinez-garcia et al., 2011). sedimentary sequences of this time interval outcrop in western sicily and led to a former proposal of the chronostratigraphic subdivision of the early pleistocene in three substages (ruggieri & sprovieri, 1984; ruggieri et al., 1984). in the last substage, the so-called sicilian substage, it was identified a biocalcarenite bed, including specimens of the northern guest bivalve arctica islandica, deposited during the global cooling of marine isotopic stage (mis) 22 (di stefano & rio, 1981; buccheri, 1984). though the chronostratigraphy of the early and middle pleistocene has been issued following different criteria (gibbard et al., 2010; head et al., 2021; suganuma et al., 2021), the western sicily is still a valuable setting to investigate paleoclimatic and paleoenvironmental modifications over this quaternary time window. here, we investigate the ostracod assemblages from casa parrino section, that outcrops in the belice valley (southwestern sicily). the sedimentary sequence starts with the a. islandica calcarenite bed and is over thirty meters thick, possibly covering the development of an almost complete glacial/interglacial cycle (di stefano et al., 1991). the investigation benefits from the comparison with different micropaleontological groups, calcareous nannofossils, planktonic and benthic foraminifera and pteropods carried out in previous studies on the same sediments (buccheri, 1985; di stefano et al., 1991) and from the comparison with casa catarinicchia section (sprovieri & cusenza, 1972), which is only a few hundreds of metres far (fig. 1a). significantly, the first report on ostracods from the the belice valley area was by ruggieri (1977), who provided a list of "northern guests" from the casa catarinicchia section. faranda & https://doi.org/10.26382/amq.2022.04 paleoenvironmental reconstruction on late calabrian stage sediments from the belice valley (southwestern sicily italy) based on ostracoda. carolina d’arpa 1, alessandro incarbona 2 1 università di palermo, sistema museale di ateneo, museo geologico g.g. gemmellaro, palermo, italy. 2 università di palermo, dipartimento delle scienze del mare e della terra, palermo, italy. corresponding authors: c. d’arpa <carolina.darpa@unipa.it> abstract: the middle pleistocene transition is the most recent re-organization of the climate system, happened between 1.2 and 0.7 ma. marine sediments outcropping in sicily have been a relevant source of information on the paleoclimatic and paleoenvironmental evolution of the mediterranean sea, over this time window. among others, previous studies in sicily identified and described the very cold phase and the marked sea level fall associated with the top mis 22, which is lithologically expressed by a calcarenite bed colonized by the arctica islandica northern guest. here we investigate ostracod assemblages from marine sediments in the southwestern sicily. sediments, ascribed to the late calabrian stage, have in-depth been studied by foraminifera, coccolith and pteropod specialists. our results support previous micropaleontological-based paleoenvironmental reconstructions, but also include original elements that better define the paleobathymetric and bottom condition evolution. by grouping infralittoral, circalittoral and bathyal taxa, ostracods describe a significant sea level fall up to the a. islandica calcarenite bed and then a rise to circalittoral and bathyal environments during the interglacial mis 21. the abundance increases of ostracod taxa able to survive in low-oxygen environments and a significant diversity loss point to the establishment of water column stratification and seafloor dysoxia, in the lower part of mis 21. finally, bythocythere turgida is the only northern guest found in our samples, associated with a. islandica specimens. however, during the interglacial period we note subtle but significant percentage variations in ostracod groups that may have been driven by productivity changes, rather than real sea level variations. these changes may be associated to atlantic meridional overturning circulation weakening phases and to millennial-scale cold spells that punctuated mis 21. keywords: marine ostracods, palaeoecology, pleistocene, mediterranean. 70 d’arpa c., incarbona a. gliozzi (2011) reviewed the “northern guest” species described in sicily sedimentary sections, including the studies on the belice valley area. the study is aimed at the reconstruction of the evolution of the depositional and environmental setting over the late calabrian stage sedimentary sequence. 2. study area the sicily fold and thrust belt is a segment of the apennine-maghrebian orogen, developed for the african and european collision (catalano et al., 2000; gasparo morticelli et al., 2015). the casa parrino section is located in the southwestern sector of sciacca-sicani mountains, where pleistocene deposits outcrop (fig. 1a) (di stefano et al., 2015a). the pliocene-calabrian interval in sicily documents two sedimentary cycles (ruggeri and sprovieri, 1984; ruggieri et al., 1984). the first one, from the zanclean to the calabrian (the former emilian substage) is represented by a regressive succession starting with “trubi” followed by grey-blue sandy clays that are progressively siltand sand-enriched and include sapropels and calcarenite turbidite layers, as in monte narbone and monte san nicola. in marginal areas, since the mpl 4 planktonic foraminifera mediterranean biozone (cita, 1975; sprovieri, 1993; lirer et al., 2019), in the upper part of the zanclean stage, there is a significant calcarenite turbiditic supply (the belice valley formazione marnoso-arenacea), as described by ruggieri and torre (1973). the second sedimentary cycle is transgressive and covers the upper part of the calabrian stage (the former emilian and sicilian substages). this cycle in the western sicily is represented by neritic to epibathyal sediments (ruggieri et al., 1979; di stefano et al., 1991). sediments outcropping in the “casa parrino” section belong to the upper part of the second sedimentary cycle. looking at the paleoceanographic and paleoclimatological framework, the casa parrino section is a former marginal area of the sicily channel. the sicily channel is a key area for the mediterranean oceanographic circulation, being the sill that divides the basin in the western and eastern subbasins and that reallocates heat and salt through the surface and intermediate layers of the thermohaline circulation (malanotte-rizzoli et al., 2014; incarbona & sprovieri, 2020). the high sensitivity of the sicily channel to late quaternary climate changes is well-established (e.g. sprovieri et al., 2003; 2006; sprovieri et al., 2012; incarbona et al., 2008, 2010; 2013; 2016; 2019) and represents a key reference area for mediterranean paleoenvironmental changes. the sicily channel is significantly affected by sea surface temperature (sst) variations in the north atlantic ocean that drive different atmospheric patterns (e.g. north atlantic oscillation) and the arrival of moisture and storm track penetration (josey et al., 2011; incarbona et al., 2016; 2019), as well under the indirect influence of north africa monsoon activity that leads to different physico-chemical properties in the intermediate water (incarbona et al., 2011; 2016; incarbona & sprovieri; 2020). 3. casa parrino section the casa parrino locality is located close to the belice river mouth (fig.1a) and belongs to a repeatedly faulted monoclinal with a slight (5-6°) southward dip (sprovieri & cusenza, 1972; buccheri, 1985, di stefano et al., 1991). the section is 50 m thick but only the first 32 m were sampled. the short description below follows di stefano et al. (1991) and is shown in figure 1b by a lithological log. the sequence starts with 1.25 m of grey clayey marls (sample 1-7), passing into sands and topped off with a 0.90 cm thick layer of greyish biocalcarenites (samples 8-11) where specimens of a. islandica occur. ditrupa arietina is common to abundant in samples 3-6. the calcarenite bed is especially enriched of marine invertebrate shells that, in the middle part, seem to be reworked by storm waves in a 15 cm-thick rippled-layer. the rest of the section consists of grey clays (sample 12 -41), up to the top where a yellow sand layer occurs. grey clays are poor in macro-invertebrate elements and include a few sand interbedded layers (fig. 1b). the entire sequence is cut off by the erosional phase which gave origin to the great upper terrace (the so-called grande terrazzo superiore), visible in a large portion of western sicily (ruggieri & unti, 1974). sediments of the great upper terrace are fossil-barren conglomerates and rounded coarse sands. presently, the casa parrino succession is only in part visible because, during the 90's, the richly fossiliferous calcarenitic levels have been object of several sampling that have nearly demolished the level itself; the part, survived at the sampling, is now almost completely covered by an illegal dump that has completely scarred the area. only the grey clay overlying the calcarenitic bed survived to human activity and can actually be seen. 4. biostratigraphic and chronostratigraphic framework the casa parrino section is ascribed to the calcareous nannofossil mnn 19f zone (rio et al., 1990) on the basis of the occurrence of gephyrocapsa omega and pseudoemiliana lacunosa specimens (di stefano et al., 1991). on the basis of the occurrence of globorotalia truncatulinoides excelsa (di stefano et al., 1991) and the common occurrence of neogloboquadrina pachyderma sinistral coiling, sediments are also referred to the planktonic foraminifera globorotalia truncatulinoides excelsa biozone (cita, 1975; sprovieri, 1993). the identification of the planktonic foraminifera biozone in the lirer et al. (2019) could not be applied, because of the fine quantitative approach used in the scheme (neogloboquadrina pachyderma sinistral coiling last regular occurrence and paracme end) for discerning between mple1c and mple2a. the biostratigraphic zones identified by calcareous nannofossils and planktonic foraminifera is compatible with the late calabrian stage (rio et al., 1990; sprovieri, 1993; lirer et al., 2019). since the a. islandica limestone in the lowermost part of the casa parrino section is correlated with that identified at cava puleo (di stefano and rio, 1981; buccheri, 1984), the investigated sedimentary section is ascribed to the uppermost part of mis 71 paleoenvironmental reconstruction on late calabrian stage sediments from the belice valley (southwestern sicily italy) based on ostracoda 22 and to part of mis 21 (buccheri, 1985; di stefano et al., 1991). the biostratigraphic and chronostratigraphic framework is summarized in figure 1b. 5. methods the present study considered the same 41 samples used by buccheri, 1985 and di stefano et al. (1991) for the study of nannofossils and benthic and planktonic foraminifera. the samples were taken at about 20 cm intervals in the lower part of the sequence until the limestone block (the lowermost 2.1 m) and about at one meter in the remnant part of the succession. samples were washed using a 63 μm mesh sieve and were oven-dried at 40 °c. the identification of species was carried out on the basis of shape and size of the valves, surface ornamentation, types of marginal pore canals, and internal features including the hinge, muscle imprints, inner lamella and vestibule, by a stereoscopic microscope. transmitted light microscopy was also used to observe characteristics not discernible with a stereoscopic microscope, such as marginal pore canals. taxa identification follows modern literature reviews and/or single holotypes original description (e.g. moore, 1961; van morkhoven, 1962; mueller, 1894; 1912, ruggieri, 1976 a,b, 1992; schornikov, 1966; ciampo, 1972, 1976; sissingh, 1972; bonaduce et al., 1976, 1999; colalongo & pasini, 1980; athersuch et al., 1989; abate et al.,1993; d'arpa & ruggieri, 2004; aiello et al., 1993,1996a, b, 2000; barra & bonaduce, 2000). all adult and juvenile ostracods were picked for reconstructing relative abundance and diversity curves, when at least 50 specimens were found in the sample. twelve samples (14, 15, 17, 20, 21, 22, 23, 28, 29, 38, 39 and 41) were ruled out because of the insufficient number of specimens (supplementary material). juvenile valves are ruled out when they are not occurring with adult specimens. a few specimens of the freshwater cypria spp. (bunbury, 2012), occurring up to the calcarenite bed top, were ruled out as allochtonous. the shannon-wiener diversity h-index was assessed by: h = -� [(pi) * log(pi)] where pi = n/n, and where n is the number of individuals of a given species and n is the total number of individuals of the assemblage. infralittoral taxa abundance is calculated by the sum of aurila spp., cimbaurila latisolea, callistocythere flavidofusca, callistocythere pallida, carinocythereis carinata, citherella circumpunctata, citherella vulgata, pontocythere rubra, leptocythere spp. and loxoconchidea minima. circalittoral taxa abundance is calculated by the sum of semicytherura spp., sagmatocythere spp., loxoconcha spp., eucitherura spp., hemicytherura spp., bosquetina dentata, cytheropteron spp., callistocythere adriatica, callistocythere crispata, callistocythere littoralis, callistocythere rastrifera, callistocythere ephemera, costa edwardsii and cytheridea neapolitana. bathyal taxa abundance is calculated by fig. 1 location of the study area and stratigraphic log of the investigated section. a: location of the casa parrino section and structural map of the southwestern sicily (modified from di stefano et al., 2015a). b): simplified lithostratigraphic log of the casa parrino section. chronostratigraphic, planktonic foraminifera and nannofossil biostratigraphic information are also provided. 2007). however, independently from a numerical bathymetric range, they still retain information on the original bottom environment, especially when assemblages, and not single taxa, are taken into account in the reconstruction. basal marl samples (0.0-1.2 m depth) show the occurrence of bathyal taxa that disappear within the a. islandica calcarenite bed (1.2-2.1 m depth), where an increasing number of infralittoral taxa specimens is recorded (fig. 5a). circalittoral taxa specimens occur in both marl and sandy samples, though they clearly decrease in relative abundance in the calcarenite bed (fig. 5a). thus, ostracod groups abundance changes indicate a pronounced sea level fall, in agreement with relative sea level fluctuations (fig. 5c) that led to a drastic fall down to about -100 m depth at the top of mis 22 (rohling et al., 2014). the significant sea level fall described between basal marls and the calcarenite bed is also in agreement with the benthic foraminifera bathymetric reconstruction that suggests the rapid change from the epibathyal (100-150 m depth) to infralittoral environment (no more than 40 m depth) (di stefano et al., 1991). from the a. islandica calcarenite bed top (2.1 m depth), infralittoral taxa show an abundance decline up to 9.0 m depth, where they permanently cease to be a significant component of ostracod assemblages and are replaced by an abundant number of circalittoral specimens (fig. 5a). this bathymetric deepening is likely related to the gradual oxygen isotopic lightening during the mis 22-21 termination x (lisiecki and raymo, 2005; hodell et al., 2015) (fig. 5d) and the rapid sea level rise (fig. 5c). the establishment of the climatic optimum, marked by permanent light oxygen isotopic values in the mis 21g plateau (lisiecki and raymo, 2005; hughes and gibbard, 2018), as well a permanent sea level like to the modern one (fig. 5c), may be indicated by the bathyal-circalittoral taxa abundance reversal at 11.0 m depth, which extends as far as the top of the casa parrino section (fig. 5a). this reversal implies the deepening to an epibathyal environment, in agreement with a 100-120 water depth by benthic foraminifera estimates (di stefano et al., 1991). 7.2. bottom water oxygen in figure 5c, the abundance percentages of ostracod taxa (c. neapolitana and the genus loxoconcha), able to survive in low-oxygen environments (barbieri et al., 2019; salvi et al., 2020), and the infaunal/epifaunal ratio (maiorano et al., 2008; aiello et al., 2015) are shown. the only significant interval when oxygen deficiency species and the infaunal/epifaunal ratio significantly increase is recorded during termination x and the earliest mis 21 (see section 7.1), while the most significant diversity loss (fig. 2) and the lowest number of specimens, even < 50 (supplementary material), is also observed. we argue that bottom water dysoxia may be developed in the sicily channel at the passage between mis 22 and mis 21, in response to water column stratification. increased summer insolation may have prevented water column convection, as observed during the two last interglacial phases, by planktonic foraminifera and the sum of henryhowella sarsii, krithe spp., buntonia sublatissima, pterygocythereis jonesii and bairdia conformis. taxa cited as a genus include just species found in the study and listed in supplementary material. the attribution of bathymetric environments (infralittoral, circalittoral and bathyal) follows relevant literature (yassini, 1969; uffenorde, 1972; bonaduce & pugliese, 1975; bonaduce et al., 1976, 1977, 1983, 1988, 1999; athersuch et al., 1989; barra et al., 1998; montenegro et al., 1998; didiè and bauch, 2000; didiè, 2001; faranda et al., 2007; frezza & di bella, 2015; maiorano et al., 2008; sciuto & rosso, 2002, 2008; aiello et al., 2015, 2018, 2020, 2021). the infaunal/epifaunal ratio follows maiorano et al. (2008) and aiello et al. (2015) and is formulated by the number of krithe spp. / (h. sarsii + cytheropteron spp.) specimens. 6. results the ostracofauna is generally well preserved and 108 species belonging to 42 genera were identified (supplementary material). selected species are illustrated in plates i and ii. the highest diversity is recorded in the lowermost part of the section and gradually decreases up to 15 m depth, where a constant value around 1 is observed (fig. 2). callistocythere ephemera (<38.4%, dominant just at 7 m depth), c. edwardsii (<53.8%) and h. sarsii (<78.9%) are the dominant species from 7 m depth up to the top of the section (fig. 2). in the lower part of the section (< 7 m depth), many species contribute to the assemblage without a clear dominance role, except h. sarsii which is again the dominant species in basal samples (fig. 2). bairdia conformis, eucytherura patercoli, krithe compressa, semicytherura acuticostata and urocythereis sp. are common and show percentage value peaks over 10% in the first 2.1 m depth of the section (figs. 3-4). aurila convexa, aurila nana, aurila punctata, cytherella circumpunctata, c. vulgata, c. neapolitana, leptocythere multipunctata and loxoconcha ovulata are common and show percentage value peaks over 10% between 2.1 and 7 m depth (figs. 2, 4). a unique peak of bythocythere turgida occurs within the a. islandica calcarenite bed (fig. 2). 7. discussion 7.1. bathymetric evolution in the following, we show the bathymetric evolution in the casa parrino section, based on the environmental preference of ostracod taxa, grouped in infralittoral, circalittoral and bathyal assemblages (see section 5 and references therein) (fig. 5a). ostracod taxa identified at the studied section are benthic organisms and respond to different factors, among others the kind of substrate, organic matter and oxygen availability on the sea floor. as observed for benthic foraminifera, they do not provide reliable paleodepth estimates, since bathymetric ranges for single species changes in different areas, especially due to different organic matter fluxes (de rijk et al., 1999, 2000; van der zwaan et al., 1990, 1999; jorissen et al., 72 d’arpa c., incarbona a. fig. 2 distribution pattern of selected ostracod taxa, expressed in percentage values, and their diversity. the simplified lithostratigraphic log is also shown. asterisks mark samples with < 50 ostracod specimens. fig. 3 distribution pattern of selected ostracod taxa, expressed in percentage values. the simplified lithostratigraphic log is also shown. asterisks mark samples with < 50 ostracod specimens. 73 paleoenvironmental reconstruction on late calabrian stage sediments from the belice valley (southwestern sicily italy) based on ostracoda nannofossil assemblages (e.g. increased abundance of globigerinoides ruber and florisphaera profunda) and by the difference between oxygen isotopic values of benthic and planktonic foraminifera species (sprovieri et al., 2003, 2006; incarbona et al., 2008, 2011, 2013; sprovieri et al., 2012; incarbona & sprovieri, 2020). the same phenomenon, dealing with summer water column stratification down to the lower photic zone, is evident across the whole central-western mediterranean sea for the holocene and the last interglacial (flores et al., 1997; sbaffi et al., 2001; perez-folgado et al., 2004; incarbona et al., 2008; ausin et al., 2015; di stefano et al., 2015b; bazzicalupo et al., 2018, 2020). the sea bottom oxygen deficiency at the case parrino section, above the calcarenite bed, is further confirmed by the occurrence of pyrite, diverity loss in benthic foraminifera assemblages and the occurrence of low-oxygen tolerant taxa (globobulimina spp.) (di stefano et al., 1991). it is noteworthy that a sapropel layer deposited on the eastern mediterranean seafloor, as shown by ocean drilling program 967 site ba/al and pc2 (fig. 5f-g), respectively proxies for enhanced productivity and north africa river runoff (grant et al., 2017), around ~ 864 ka. though there is no sign of laminites in the case parrino section, as well in the sicily channel middle pleistocene sediments (emeis et al., 1996), it is well-established that the eastern mediterranean carbon-enriched layer deposition led to mediterranean thermohaline circulation perturbation and and had a large-scale impact (sprovieri et al., 2003; incarbona et al., 2011; incarbona & sprovieri, 2020). in particular, the thermohaline circulation would significantly have weakened across the sicily strait, where oxygen-depleted water masses of the surface-intermediate cells would be exchanged between the sub-basins (rohling, 1991; myers et al., 1998; incarbona & sprovieri, 2020). thus, the weakened mediterranean circulation may have further sea bottom oxygen deficiency, observed in ostracod and benthic foraminifera assemblages, at least during the earliest mis 21. 7.3. paleoclimatic inferences several ostracod species are known to be quaternary northern guest in the mediterranean sea (faranda & gliozzi, 2011). in the casa parrino section, just one of these taxa, b. turgida (ruggieri, 1976a; faranda and gliozzi 2011, sciuto, 2016), exhibit an abundance spike in coincidence of the a. islandica calcarenite bed (fig. 2), where the intense climatic cooling is also marked by the subarctic species limacina retroversa increase in the pteropod assemblage (buccheri, 1985). apparently, no other sign of climatic oscillation may be gathered from ostracod taxa in the studied section. however, four episodes of distinct changes exist in the distribution pattern of bathyal and circalittoral taxa (black arrows and question marks in fig. 5a) between 17 and 27 m depth. looking at the atlantic meridional overturning circulation (amoc) from the log ca/ti record by hodell et al. (2015) in the iberian margin, there are four fig. 4 distribution pattern of selected ostracod taxa, expressed in percentage values. the simplified lithostratigraphic log is also shown. asterisks mark samples with < 50 ostracod specimens. 74 d’arpa c., incarbona a. plate ia: 1) cytherella scutulum, lv, lateral external view; 2) cytherella vulgata, rv, lateral external view; 3) costa edwardsii, lv, lateral external view; 4) carinocyhtereis carinata, lv, lateral external view; 5) callistocythere adriatica, lv, lateral external view; 6) callistocythere (rastrocythere) ephemera, lv, lateral external view; 7) leptocythere multipunctata, rv, lateral external view; 8) henryhowella sarsii, lv, lateral external view; 9) henryhowella sarsii, rv, lateral external view; 10) buntonia sublatissima, rv, lateral external view; 11) pterygocythereis jonesii, lv, lateral external view; 12) hemicytherura videns, lv, lateral external view. the scale bar is 100 μm. 75 paleoenvironmental reconstruction on late calabrian stage sediments from the belice valley (southwestern sicily italy) based on ostracoda plate ib: 13) cytheridea neapolitana, rv, lateral external view; 14) loxoconcha cfr. gibberosa, lv, lateral external view; 15) cytheropteon sulcatum, rv, lateral external view; 16) cytheropteron cfr. monoceros, lv, lateral external view; 17) paracytheridea triquetra, rv, lateral external view; 18) eucytherura patercoli, lv, lateral external view; 19) semicytherura rara, rv, lateral external view; 20) semicytherura alifera, rv, lateral external view; 21) semicytherura frenzeli, rv, lateral external view. the scale bar is 100 μm. 76 d’arpa c., incarbona a. fig. 5 distribution pattern of selected ostracod taxa, groups and ratio (plotted versus depth) in comparison with global, mediterranean sea and atlantic ocean paleoenvironmental and paleoclimatic proxy data (plotted versus age, kiloyears ago, following their own original age model). a: infralittoral (red line), circalittoral (orange line) and bathyal (green line) ostracod groups. the four black arrows and question marks indicate the possible mis 21 cold spells. b: deficiency oxygen stress ostracod taxa (red and orange lines) and the infaunal/epifaunal ratio, krithe spp. / (h. sarsii + cytheropteron spp.) specimens, following maiorano et al. (2008) and aiello et al. (2015) (black line). c: relative sea level variations, expressed in m compared to today (0 m) (rohling et al., 2014). d: benthic foraminifera d18o from the iberian margin (hodell et al., 2015) (blue line) and the lr04 stack (lisiecki and raymo, 2005) (light blue line). e: very high-resolution log (ca/ti) record in the iberian margin (hodell et al., 2015), proxy for the amoc circulation. a-g show mis 21 substages. black arrows show the four episodes of amoc slowdown/shutdown within mis 21. f: ba/al ratio at odp 967 site (grant et al., 2017), whose peaks indicate enhanced productivity in the eastern mediterranean sea during sapropel layer deposition. s*4 is the name for the sapropel layer identified in the earliest mis 21 (grant et al., 2017). g: principal component (pc) 2 for elemental proxies at odp 967 site (grant et al., 2017), whose peaks indicate enhanced north africa river runoff. 77 paleoenvironmental reconstruction on late calabrian stage sediments from the belice valley (southwestern sicily italy) based on ostracoda episodes of slowdown during mis 21. it is wellestablished as amoc slowdown/shutdown episodes led to millennial-scale climatic instability even during interglacials (martrat et al., 2004, 2007, 2014; tzedakis et al., 2018) and produced pronounced cooling even in the mediterranean sea (manabe & stouffer, 1997; vellinga and wood, 2002; sprovieri et al., 2006). coupling millennial-scale cold spells to relative sea level drops, as they would be indicated by increased relative abundance of circalittoral ostracods versus bathyal ones, is not a straightforward issue. in the last glacial period, sea level variations during dansgaardoeschger variability could be affected by rapid cycles of accumulation/melt in the antarctica ice sheet, whose millennial-scale climatic variations are in anti-phase (siddall et al., 2003; rohling et al., 2004). thus, we are not sure that bathymetric fluctuations indicated by ostracod groups, since the middle part of the casa parrino section, are truly related to sea level fall, though the sea level indeed felt down to ~ -50 m between 850 and 835 ka (fig. 5c). as introduced in section 7.1, benthic organisms may migrate through different bathymetry following food supply fluxes. in the modern eastern mediterranean sea, where oligotrophic conditions persist, many benthic foraminifera species tend to occupy a shallower position. thus, we argue that the apparent bathymetric fluctuations shown by ostracod groups may be driven by productivity changes, rather than real sea level variations. increased circalittoral taxa percentages may be due to decreased productivity during cold spells, as observed in sicily channel calcareous plankton assemblages (incarbona et al., 2013). if true, the link between ostracod bathymetric fluctuations and amoc variations, may provide tie-points for sedimentation rate estimates at casa parrino, that would range between 45.9 and 51.7 cm/kyr, in line with other middle pleistocene southern italy outcrops of a relatively shallow environment (maiorano et al., 2008; capraro et al., 2011). planktonic foraminifera assemblages indicate the occurrence of an episode of climate deterioration at 23 m depth, coinciding with the penultimate episode of ostracod circalittoral taxa increase (fig. 5a), and a general cooling trend for the upper part of the studied section (di stefano et al., 1991). ostracod assemblages do not show a similar cooling, as well as that a new glacial cycle has been established in the uppermost part of the record, perhaps indicating that the top of the section is still deposited during the interglacial mis 21. 8. conclusion ostracod assemblages in 41 samples from the casa parrino section were investigated, aimed at reconstructing paleoenvironmental conditions, over the late calabrian stage (calcareous nannofossil mnn 19f zone, di stefano et al., 1991). a total of 108 species and 42 genera were identified. the highest diversity is recorded in the lowermost part of the section and gradually decreases up to 15 m depth. callistocythere ephemera, c. edwardsii and h. sarsii are the dominant species except for the lower part of the section where many species contribute to the assemblage without a clear dominance role (figs. 2-3). the bathymetric evolution was carried out grouping infralittoral, circalittoral and bathyal taxa. we show a marked sea level drop in the lower part of the section, up to the top of the a. islandica calcarenite bed (2.1 m depth). then, infralittoral taxa cease to be a significant component of ostracod assemblages at 9.0 m depth, replaced by an abundant number of circalittoral specimens (fig. 5a). the bathyal-circalittoral taxa abundance reversal at 11.0 m depth, which extends as far as the top of the casa parrino section (fig. 5a), marks the deepening to an epibathyal environment, in agreement with water depth estimates by benthic foraminifera (di stefano et al., 1991). this paleobathymetric sketch is compatible with eustatic sea level changes, depicted for the upper part of mis 22 and mis 21 (rohling et al., 2014) (fig. 5c). the significant occurrence of c. neapolitana and the genus loxoconcha specimens, high values in the infaunal/epifaunal ratio (maiorano et al., 2008; aiello et al., 2015) (fig. 5b) and the decreased diversity suggest the development of bottom water dysoxia at the passage between mis 22 and mis 21, in response to water column stratification. bottom oxygen deficiency may have been worsened by the thermohaline circulation weakening of the surface-intermediate cells during the depostion of a sapropel layer in the eastern mediterranean sea in the earliest mis 21 (grant et al., 2017) (fig. 5fg). bythocythere turgida is the only quaternary northern guest that was identified in the casa parrino section, in coincidence of the a. islandica calcarenite bed (fig. 2), where the intense climatic cooling is also marked by the subarctic species limacina retroversa increase in the pteropod assemblage (buccheri, 1985). however, we note four episodes of increased relative abundance of circalittoral ostracods versus bathyal ones (fig. 5a) that may reflect different organic matter pulses. these subtle productivity change events may be occurred during cold spells, driven by amoc weakening (fig. 5e), like for late quaternary interglacial and glacial cycles (martrat et al., 2004, 2007; incarbona et al., 2013; tzedakis et al., 2018). acknowledgments we are grateful to the anonymous reviewer for his valuable comments and suggestions and to francesco furnari for sem photographs. references abate s., barra d., aiello g., bonaduce g. (1993) the genus krithe brady, crosskey & robertson, 1874 (crustacea: ostracoda) in the pliocene-early pleistocene of the m. san nicola section (gela, sicily). bollettino della società paleontologica italiana, 32(3), 349-366. aiello g., amato v., barra d., caporaso l., caruso t., giaccio b., parisi r., rossi a. (2020) late quaternary benthic foraminiferal and ostracod response to palaeoenvironmental changes in a mediterranean coastal area, port of salerno, tyrrhenian sea. regional studies in marine science, 40, 110. 78 d’arpa c., incarbona a. doi: 10.1016/j.rsma.2020.101498 aiello g., barra d., abate s., bonaduce g. (1993) the genus parakrithe van den bold 1958 (ostracoda) in the pliocene-early pleistocene of sicily. bollettino della società paleontologica italiana, 32(2), 277-285. aiello g., barra d., bonaduce g. (1996a) the genus cytheropteron sars 1866 (crustacea: ostracoda) in the pliocene-early pleistocene of the m. san nicola section (gela, sicily). micropaleontology, 42(2), 167-178. aiello g., barra d., bonaduce g., russo a. (1996b) the genus cytherella jones 1849 (ostracoda) in the italian tortonian-recent. revue de micropaléontologie, 39(3), 171-190. aiello g., barra d., bonaduce g. (2000) systematics and biostratigraphy of the ostracoda of the pliopleistocene monte s. nicola section (gela, sicily). bollettino della società paleontologica italiana, 39 (1), 83-112. aiello g., barra d., parisi r. (2015) lower-middle pleistocene ostracod assemblages from the montalbano jonico section (basilicata, southern italy). quaternary international, 383, 47-73. aiello g., barra d., parisi r., arienzo m., donadio c., ferrara l., toscanesi m., trifuoggi m. (2021) infralittoral ostracoda and benthic foraminifera of the gulf of pozzuoli (tyrrhenian sea, italy). aquatic ecology, 55, 955-998. doi: 10.1007/s10452-021-09874-1 aiello g., barra d., parisi r., isaia r., marturano a. (2018) holocene benthic foraminiferal and ostracod assemblages in a paleo-hydrothermal vent system of campi flegrei (campania, south italy). palaeontologia electronica 21.3.41a, 1-71. doi: 10.26879/835 athersuch j., horne d.j., whittaker j.e. (1989) marine and brackish water ostracods (superfamilies cypridacea and cytheracea), in: barbeito-gonzàlez, p.j., 1971. die ostracoden des küstenbereiches von naxos (griechenland) und ihre lebensbereiche. mitteilungen aus dem hamburgischen zoologischen museum und institut, 67, 255-326. ausín b., flores j.a., sierro f. j., bárcena m.a., hernández-almeida i., francés g., gutiérrezarnillas e., martrat b., grimalt j.o., cacho i. (2015) coccolithophore productivity and surface water dynamics in the alboran sea during the last 25kyr. palaeogeography, palaeoclimatology, palaeoecology, 418, 126-140. doi: 10.1016/j.palaeo.2014.11.011 barbieri g., rossi v., vaiani s.c., horton b.p. (2019) benthic ostracoda and foraminifera from the north adriatic sea (italy, mediterranean sea): a proxy for the depositional characterisation of riverinfluenced shelves. marine micropaleontology, 153, 101772. doi: 10.1016/j.marmicro.2019.101772 barra d., bonaduce g. (2000) some species of echinocythereis puri, 1954 (crustacea, ostracoda) from the tortonian to recent. revista espanõla de micropaleontologia, 32(2), 213-224. barra d., bonaduce g., sgarrella f. (1998) paleoenvironmental bottom water conditions in the early zanclean of the capo rossello area (agrigento, sicily). bollettino della società paleontologica italiana, 37(1), 61-88. bazzicalupo p., maiorano p., girone a., marino m., combourieu-nebout n., incarbona a. (2018) high-frequency climate fluctuations over the last deglaciation in the alboran sea, western mediterranean: evidence from calcareous plankton assemblages. palaeogeography, palaeoclimatology, palaeoecology, 506, 226-241. bazzicalupo, p., maiorano, p., girone, a., marino, m., combourieu-nebout, n., pelosi, n., salgueiro, e., & incarbona, a. (2020) holocene climate variability of the western mediterranean: surface water dynamics inferred from calcareous plankton assemblages. the holocene, 30, 691-708. bonaduce g., pugliese n. (1975) ostracoda from lybia. pubblicazioni della stazione zoologica di napoli, 39, 129-135. bonaduce g., barra d., aiello g. (1999) the genus henryhowella puri, 1957 (crustacea, ostracoda) in the atlantic and mediterranean from miocene to recent. bollettino della società paleontologica italiana, 38(1), 59-72. bonaduce g., ciampo g., masoli m. (1976) distribution of ostracoda in the adriatic sea. pubblicazioni della stazione zoologica di napoli, 40(suppl.), 1304. bonaduce g., ciliberto b., masoli m., minichelli g., pugliese n. (1983) the deep-water benthic ostracodes of the mediterranean. in: maddocks r.f. (ed.), applications of ostracoda. university of houston, 459-471. bonaduce g., masoli m., pugliese n. (1977) ostracodi bentonici dell’alto tirreno. studi tridentini di scienze naturali acta biol. 54, 243-261. bonaduce g., masoli m., pugliese n. (1988) remarks on the benthic ostracoda on the tunisian shelf. in: hanai t., ikeya n., ishizaki k. (eds.), evolutionary biology of ostracoda, proceeding 9 symposium on ostracoda, 449-466. buccheri g. (1984) pteropods as climatic indicators in quaternary sequences: a lower-middle pleistocene sequence outcropping in cava puleo (ficarazzi, palermo, italy). palaeogeography, palaeoclimatology, palaeoecology, 45(1), 75-86. buccheri g. (1985) osservazioni paleoclimatiche al limite pleistocene inferiore pleistocene medio della foce del belice (sicilia sud-occidentale) mediante l'uso degli pteropodi. bollettino della società paleontologica italiana, 104, 115-122. bunbury j. (2012) chapter 7 distribution of freshwater ostracods in the canadian north and implications for palaeoclimate reconstructions. in horne d.j., holmes j.a., rodriguez-lazaro j., viehberg f.a. (eds.), ostracoda as proxies for quaternary climate change, 17, 117-129, elsevier. doi: 10.1016/b978-0-444-53636-5.00007-x capraro l., massari f., rio d., fornaciari e., backman j., channell j.e.t., macrì p., prosser g., speranza f. (2011) chronology of the lowermiddle pleistocene succession of the south 79 paleoenvironmental reconstruction on late calabrian stage sediments from the belice valley (southwestern sicily italy) based on ostracoda western part of the crotone basin (calabria, southern italy). quaternary science reviews, 30(910), 1185-1200. doi: 10.1016/j.quascirev.2011.02.008 catalano r., franchino a., merlini s., sulli a. (2000) central western sicily structural setting interpreted from seismic reflection profiles. memorie della società geologica italiana, 55, 5-16. ciampo g. (1972) gli ostracodi delle argille pleistoceniche del mar piccolo (taranto). bollettino della società dei naturalisti in napoli, 80, 277-299. ciampo g. (1976) ostracodi pleistocenici di cala bianca (marina di camerata, salerno). bollettino della società paleontologica italiana, 15(1), 3-23. cita m.b. (1975) studi sul pliocene e gli strati di passaggio dal miocene al pliocene. vii. planktonic foraminiferal biozonation of the mediterranean pliocene deep-sea record. a revision. rivista italiana di paleontologia e stratigrafia, 81, 527-544. clark p.u., archer d., pollard d., blum j.d., rial j.a., brovkin v., mix a.c., pisias n.g. roy m. (2006) the middle pleistocene transition: characteristics, mechanisms, and implications for long-term changes in atmospheric pco2. quaternary science reviews, 25(23), 3150-3184. doi: 10.1016/j.quascirev.2006.07.008 colalongo m.l., pasini g. (1980) l’ostracofauna pliopleistocenica della sezione di vrica in calabria (con considerazioni sul limite neogene/ quaternario). bollettino della società paleontologica italiana, 19(1), 44-126. d'arpa c., ruggieri g. (2004) pliocene ostracofauna of the altavilla section (altavilla milicia, sicily). systematic remarks. bollettino della società paleontologica italiana, 43(1-2), 159-180. de rijk s., hayes a., rohling e.j. (1999) eastern mediterranean sapropel s1 interruption: an expression of the onset of climatic deterioration around 7 ka bp. marine geology, 153(1-4), 337-343. doi: 10.1016/s0025-3227(98)00075-9 de rijk s., jorissen f.j., rohling e.j., troelstra s.r. (2000) organic flux control on bathymetric zonation of mediterranean benthic foraminifera. marine micropaleontology, 40(3), 151-166. doi: 10.1016/s0377-8398(00)00037-2 di stefano p., favara r., luzio d., renda p., cacciatore m.s., calò m., napoli g., parisi l., todaro s., zarcone g. (2015b) – a regional-scale discontinuity in western sicily revealed by a multidisciplinary approach: a new piece for understanding the geodynamic puzzle of the southern mediterranean. tectonics, 34, 2067-2085 di stefano e., sprovieri r., scarantino s. (1991) biostratigrafia e paleoecologia della sezione intrapleistocenica di casa parrino (foce del belice, sicilia sud -occidentale). naturalista siciliano, s iv, xv (3-4), 115-148. di stefano e., rio d. (1981) biostratigrafia a nannofossili e biocronologia del siciliano nella località tipo di ficarazzi (palermo, sicilia). acta naturalia de l’ateneo parmense, 17, 97-111. di stefano a., foresi, l.m., incarbona a., sprovieri m., vallefuoco m., iorio m., pelosi n., di stefano e., sangiorgi p., budillon f. (2015b) mediterranean coccolith ecobiostratigraphy since the penultimate glacial (the last 145,000years) and ecobioevent traceability. marine micropaleontology, 115. doi: 10.1016/j.marmicro.2014.12.002 didiè c. (2001) late quaternary climate variations recorded in north atlantic deep-sea benthic ostracodes. ber polar meeresforsch., 390, 1-121. didié c., bauch h.a. (2000) species composition and glacial-interglacial variations in the ostracode fauna of the northeast atlantic during the past 200,000 years. marine micropaleontology, 40, 105129. emeis k.c., robertson a.h.f., richter c., shipboard party. (1996) site 963. in: proceedings of the ocean drilling program, initial reports, leg 160 (emeis k.-c, robertson a.h.f., richter c. (eds), 160, 55-84) faranda c., gliozzi e., mazzini i. (2007) palaeoenvironmental evolution of the plio-pleistocene monte mario succession (rome, italy) inferred from ostracod assemblages. rivista italiana di paleontologia e stratigrafia, 113(3), 473-485. faranda c., gliozzi e. (2011) a revision of the "northern guest" ostracoda (crustacea) occurence in the quaternary of the mediterranean area. il quarternario, 24(1), 75-92. flores j.a., sierro f.j., francés g., vazquez a., zamarreno i. (1997) the last 100,000 years in the western mediterranean: sea surface water and frontal dynamics as revealed by coccolithophores. marine micropaleontology, 29, 351-366. frezza v., di bella l. (2015) distribution of recent ostracods near the ombrone river mouth (northern tyrrhenian sea, italy). micropaleontology, 61, 101-114. gasparo morticelli m., valenti v., catalano r., sulli a., agate m., avellone g., albanese c., basilone l., gugliotta c. (2015) deep controls on foreland basin system evolution along the sicilian fold and thrust belt. bulletin de la société géologique de france, 186(4-5), 273-290. doi: 10.2113/gssgfbull.186.4-5.273 gibbard p.l., head m.j., walker m.j.c., stratigraphy, & the subcommission on quaternary (2010) formal ratification of the quaternary system/period and the pleistocene series/epoch with a base at 2.58ma. journal of quaternary science, 25(2), 96102. doi: 10.1002/jqs grant k.m., rohling e.j., westerhold t., zabel m., heslop d., konijnendijk t., lourens l. (2017) a 3 million year index for north african humidity/aridity and the implication of potential pan-african humid periods. quaternary science reviews, 171, 100118. doi: 10.1016/j.quascirev.2017.07.005 head m.j., pillans b., zalasiewicz j.a. (2021) formal ratification of subseries for the pleistocene series of the quaternary system. episodes, 44(3), 241247. doi: 10.18814/epiiugs/2020/020084 hodell d., lourens l., crowhurst s., konijnendijk t., 80 d’arpa c., incarbona a. tjallingii r., jiménez-espejo f., skinner l., tzedakis p.c., abrantes f., acton g.d., zarikian c.a.a., bahr a., balestra b., barranco e.l., carrara g., ducassou e., flood r.d., flores j.a., furota s., williams t. (2015) a reference time scale for site u1385 (shackleton site) on the sw iberian margin. global and planetary change, 133, 49-64. doi: 10.1016/j.gloplacha.2015.07.002 holmes j.a., chivas a.r. (2002) the ostracoda: applications in quaternary research. geophysical monograph series (131). agu, washington, us, 1 -133. doi: 10.1029/131gm01 hughes p.d., gibbard p.l. (2018) global glacier dynamics during 100 ka pleistocene glacial cycles. quaternary research, 90(1), 222-243. doi: 10.1017/qua.2018.37 incarbona a., di stefano e., parti b., pelosi n., bonomo s., mazzola s., sprovieri r., tranchida g., zgozi s., bonanno a. (2008) holocene millennial-scale productivity variations in the sicily channel (mediterranean sea). paleoceanography, 23(3), 118. doi: 10.1029/2007pa001581 incarbona a., jonkers l., ferraro s., sprovieri r., tranchida g. (2019) sea surface temperatures and paleoenvironmental variability in the central mediterranean during historical times reconstructed using planktonic foraminifera. paleoceanography and paleoclimatology, 34(3), 394-408. doi: 10.1029/2018pa003529 incarbona a., martrat b., mortyn p.g., sprovieri m., ziveri p., gogou a., jordà g., xoplaki e., luterbacher j., langone l., marino g., rodríguezsanz l., triantaphyllou m., di stefano e., grimalt j.o., tranchida g., sprovieri r., mazzola s. (2016) mediterranean circulation perturbations over the last five centuries: relevance to past eastern mediterranean transient-type events. scientific reports, 6. doi: 10.1038/srep29623 incarbona a., sprovieri m. (2020) the postglacial isotopic record of intermediate water connects mediterranean sapropels and organic-rich layers. paleoceanography and paleoclimatology, 35(10), e2020pa004009. doi: 10.1029/2020pa004009 incarbona a., sprovieri m., di stefano a., di stefano e., salvagio manta d., pelosi n., ribera d’alcalà m., sprovieri r., ziveri p. (2013) productivity modes in the mediterranean sea during dansgaardoeschger (20,000-70,000yr ago) oscillations. palaeogeography, palaeoclimatology, palaeoecology, 392. doi: 10.1016/j.palaeo.2013.09.023 incarbona a., sprovieri m., lirer f., sprovieri r. (2011) surface and deep water conditions in the sicily channel (central mediterranean) at the time of sapropel s5 deposition. palaeogeography, palaeoclimatology, palaeoecology, 306(3-4), 243248. doi: 10.1016/j.palaeo.2011.04.030 incarbona a., ziveri p., di stefano e., lirer f., mortyn g., patti b., pelosi n., sprovieri m., tranchida g., vallefuoco m., albertazzi s., bellucci l.g., bonanno a., bonomo s., censi p., ferraro l., giuliani s., mazzola s., sprovieri r. (2010) calcareous nannofossil assemblages from the central mediterranean sea over the last four centuries: the impact of the little ice age. climate of the past discussions, 6(3), 817-866. doi: 0.5194/cpd-6-817-2010 jorissen f.j., fontanier c., thomas e. (2007) paleoceanographical proxies based on deep-sea benthic foraminiferal assemblage characteristics. in: hillaire-marcel c, de vernal a. (eds) proxies in late cenozoic paleoceanography. elsevier publishers, amsterdam, 277-340. josey s.a., somot s., tsimplis m. (2011) impacts of atmospheric modes of variability on mediterranean sea surface heat exchange. journal of geophysical research: oceans, 116(2), 1-15. doi: 10.1029/2010jc006685 lirer f., foresi l.m., iaccarino s.m., salvatorini g., turco e., cosentino c., sierro f.j., caruso a. (2019) mediterranean neogene planktonic foraminifer biozonation and biochronology. earthscience reviews, 196, 102869. doi: 10.1016/j.earscirev.2019.05.013 lisiecki l.e., raymo m.e. (2005) a pliocenepleistocene stack of 57 globally distributed benthic d18o records. paleoceanography, 20(1), 1-17. doi: 10.1029/2004pa001071 maiorano p., aiello g., barra d., di leo p., sebastien j.s., lirer f., marino m., pappalardo a., capotondi l., ciaranfi n., stefanelli s. (2008) paleoenvironmental changes during sapropel 19 (i-cycle 90) deposition: evidences from geochemical, mineralogical and micropaleontological proxies in the mid -pleistocene montalbano jonico land section (southern italy). palaeogeography, palaeoclimatology, palaeoecology 257, 308-334. malanotte-rizzoli p., artale v., borzelli-eusebi g.l., brenner s., crise a., gacic m., kress n., marullo s., ribera d’alcalà m., sofianos s., tanhua t., theocharis a., alvarez m., ashkenazy y., bergamasco a., cardin v., carniel s., civitarese g., d’ortenzio f., font j., garcia-ladona e., garcia-lafuente j.m., gogou a., gregoire m., hainbucher d., kontoyannis h., kovacevic v., kraskapoulou e., kroskos g., incarbona a., mazzocchi m.g., orlic m., ozsoy e., pascual a., poulain p.-m., roether w., rubino a., schroeder k., siokou-frangou j., souvermezoglou e., sprovieri m., tintoré j., triantafyllou g. (2014) physical forcing and physical/biochemical variability of the mediterranean sea: a review of unresolved issues and directions for future research. ocean science 10. doi: 10.5194/os-10-281-2014 manabe s., stouffer r.j. (1997) coupled oceanatmosphere model response to freshwater input: comparison to younger dryas event. paleoceanography, 12(2), 32-336. doi: 10.1029/96pa03932 81 paleoenvironmental reconstruction on late calabrian stage sediments from the belice valley (southwestern sicily italy) based on ostracoda martínez-garcia a., rosell-melé a., jaccard s.l., geibert w., sigman d.m., haug g.h. (2011) southern ocean dust-climate coupling over the past four million years. nature, 476(7360), 312315. doi: 10.1038/nature10310 martrat b., grimalt j. o., lopez-martinez c., cacho i., sierro f.j., flores j.a., zahn r., canals m., curtis j.h., hodell d.a. (2004) abrupt temperature changes in the western mediterranean over the past 250,000 years. science, 306(5702), 17621765. doi: 10.1126/science.1101706 martrat b., grimalt j.o., shackleton n.j., de abreu l., hutterli m.a., stocker t.f. (2007) four climate cycles of recurring deep and surface water destabilizations on the iberian margin. science, 317 (5837), 502-507. doi: 10.1126/science.1139994 martrat b., jimenez-amat p., zahn r., grimalt j.o. (2014) similarities and dissimilarities between the last two deglaciations and interglaciations in the north atlantic region. quaternary science reviews, 99, 122-134. doi: 10.1016/j.quascirev.2014.06.016 montenegro m.e., pugliese n., bonaduce g. (1998) shelf ostracods distribution in the italian seas. in "what about ostracoda? actes 3° congr. europ. ostracod., 1996". bulletin des centres de recherches exploration production, elf-aquatine, memoire, 20, 91-101. moore r. c. (1961) treatise on invertebrate paleontology, part q, artropoda, 3, crustacea, ostracoda. geological society of america & university of kansas press, 1442. myers p.g., haines k., rohling e.j. (1998) modeling the paleocirculation of the mediterranean: the last glacial maximum and the holocene with emphasis on the formation of sapropel s1. paleoceanography, 13(6), 586-606. müller g.w. (1894) die ostracoden des golfes von neapel und der angrenzenden meeres-abschnitt. fauna und flora des golfes von neapel. pubblicazioni della stazione zoologica di napoli, 21, pp. 404. müller g.w. (1912) ostracoda, in das tierreich 31. leiferung, berlin, pp. 434. perçin p.f. (2011) the ecology of the ostracoda (crustacea) species obtained from the coasts of iskenderun bay (eastern mediterranean sea). j. black sea/mediterranean environment, 17(2), 127 -144. pérez-folgado m., sierro f.j., flores j.a., grimalt j.o., zahn r. (2004) paleoclimatic variations in foraminifer assemblages from the alboran sea (western mediterranean) during the last 150 ka in odp site 977. marine geology, 212(1-4), 113-131. doi: 10.1016/j.margeo.2004.08.002 rio d., raffi i., villa g. (1990) pliocene-pleistocene calcareous nannofossil distribution patterns in the western mediterranean. proc., scientific results, odp, leg 107, tyrrhenian sea, 107, 513-533. rohling e.j. (1991) shoaling of the eastern mediterranean pycnocline due to reduction of excess evaporation: implications for sapropel formation. paleoceanography, 6(6), 747-753. doi: 10.1029/91pa02455 rohling e.j., foster g.l., grant k.m., marino g., roberts a.p., tamisiea m.e., williams f. (2014) sea-level and deep-sea-temperature variability over the past 5.3 million years. nature, 508(7497), 477-482. doi: 10.1038/nature13230 rohling e.j., marsh r., wells n.c., siddall m., edwards n.r. (2004) similar meltwater contributions to glacial sea level changes from antarctic and northern ice sheets. nature, 430(7003), doi: 10.1038/nature02859 ruggieri g. (1976a) la ostracofauna pleistocenica della falesia di cinisi (sicilia). bollettino della società paleontologica italiana, 15(1), 85-106. ruggieri g. (1976b) contributo alla conoscenza del genere aurila (ostracoda, podocopa) con particolare riguardo ai suoi rappresentanti nel pleistocene italiano. bollettino della società paleontologica italiana, 14(1), 27-46. ruggieri g. (1977) nuovi ostracodi nordici nel pleistocene della sicilia. bollettino della società paleontologica italiana, 16(1), 81-85. ruggieri g. (1992) considerazioni tassonomiche su ostracodi neogenici e pleistocenici risultate dalla revisione di vecchi lavori dello scrivente. bollettino della società paleontologica italiana, 31(2), 175188. ruggieri g., torre g. (1973) geologia delle zone investite dal terremoto del belice. 1) la tavoletta di gibellina. rivista mineraria siciliana, 132-139, 2748. ruggieri g., sprovieri r. (1984) recenti progressi nella stratigrafia del pleistocene inferiore. bollettino della società paleontologica italiana, 22, 315321. ruggieri g., unti m. (1974) pliocene e pleistocene nell’entroterra di marsala. bollettino della società geologica italiana, 93, 723-733. ruggieri g., rio d., sprovieri r. (1984) remarks on chronostratigraphic classification of lower pleistocene. bollettino della società geologica italiana, 103, 251-259. ruggieri g., sprovieri r., unti m. (1979) evidenze della trasgressione dell’emiliano (pleistocene inferiore) nella sicilia orientale. bollettino della società geologica italiana, 98, 475-482. salvi g., acquavita a., celio m., ciriaco s., cirilli s., fernetti m., pugliese n. (2020) ostracod fauna: eyewitness to fifty years of anthropic impact in the gulf of trieste. a potential key to the future evolution of urban ecosystems. sustainability 2020, 12, 6954. doi: 10.3390/su12176954 sbaffi l., wezel f.c., kallel n., paterne m., cacho i., ziveri p., shackleton n. (2001) response of the pelagic environment to palaeoclimatic changes in the central mediterranean sea during the late quaternary. marine geology, 178(1-4), 39-62. doi: 10.1016/s0025-3227(01)00185-2 82 d’arpa c., incarbona a. schornikow e.i. (1966) leptocythere (crustacea, ostracoda) in the azov-black sea basin: zoologicheskiy zhurnal, 45(1), 32-49. sciuto f. (2016) ostracods associated with deep water coral colonies in the pleistocene of scoppo (messina, ne sicily) and description of two new species. bollettino della società paleontologica italiana, 55, 205-217. sciuto f., rosso a. (2002) contributo alla conoscenza di tanatocenosi ad ostracodi di fondi circalitorali al largo di aci trezza (ct, sicilia orientale). bollettino accademia gioenia scienze naturali, 35(361), 293 -309. sciuto f., rosso a. (2008) distribution of deep-water ostracod assemblages from lower pleistocene sediments from furnari, sicily. bollettino della società paleontologica italiana, 47(1), 33-43. siddall m., rohling e., almogi-labin a, hemleben c., meischner d., schmelzer i., smeed d.a. (2003) sea-level fluctuations during the last glacial cycle. nature, 423, 853-858. doi: 10.1038/nature01687.1 sissingh w. (1972) late cenozoic ostracoda of the south-aegean island arc. utrecht micropaleontological bulletins, 6, 1-187. sprovieri r. (1993) pliocene-early pleistocene astronomically forced planktonic foraminifera abundance fluctuations and chronology of mediterranean calcareous plankton bio-events. rivista italiana di paleontologia e stratigrafia, 99, 371-414. sprovieri r., cusenza a. (1972) la sezione di età siciliana della valle del belice (trapani). revista espanola de micropaleontologia, 4, 297-325. sprovieri m., di stefano e., incarbona a., salvagio manta d., pelosi n., ribera d’alcalà m., sprovieri r. (2012) centennialto millennial-scale climate oscillations in the central-eastern mediterranean sea between 20,000 and 70,000 years ago: evidence from a high-resolution geochemical and micropaleontological record. quaternary science reviews, 46, 126-135. doi: 10.1016/j.quascirev.2012.05.005 sprovieri r., di stefano e., incarbona a., gargano m.e. (2003) a high-resolution record of the last deglaciation in the sicily channel based on foraminifera and calcareous nannofossil quantitative distribution. palaeogeography, palaeoclimatology, palaeoecology, 202(1-2), 119-142. doi: 10.1016/s0031-0182(03)00632-1 sprovieri r., di stefano e., incarbona a., oppo d.w. (2006) suborbital climate variability during marine isotopic stage 5 in the central mediterranean basin: evidence from calcareous plankton record. quaternary science reviews, 25(17-18). doi: 10.1016/j.quascirev.2006.01.035 suganuma y., okada m., head m.j., kameo k., haneda y., hayashi h., irizuki t., itaki t., izumi k., kubota y., nakazato h., nishida n., okuda m., satoguchi y., simon q., takeshita y. (2021) formal ratification of the global boundary stratotype section and point (gssp) for the chibanian stage and middle pleistocene subseries of the quaternary system: the chiba section, japan. episodes, 44(3), 317-347. doi: 10.18814/epiiugs/2020/020080 tzedakis p.c., drysdale r.n., margari v., skinner l.c., menviel l., rhodes r.h., taschetto a.s., hodell d.a., crowhurst s.j., hellstrom j.c., fallick a.e., grimalt j.o., mcmanus j.f., martrat b., mokeddem z., parrenin f., regattieri e., roe k., zanchetta g. (2018) enhanced climate instability in the north atlantic and southern europe during the last interglacial. nature communications, 9 (1), 4235. doi: 10.1038/s41467-018-06683-3 uffenorde h. (1972) ökologie und jahreszeitliche verteilung rezenter benthonischer ostracoden des limiski kanal bei rovinj (nördliche adria). göttinger arbeiten zur geologie und paläontologie, 13, pp. 121. van der zwaan g.j., duijnstee i.a.p., den dulka m., ernst s.r., jannink n.t., kouwenhoven t.j. (1999) benthic foraminifers: proxies or problems? a review of paleocological concepts. earth science reviews, 46(1-4), 213-236. doi: 10.1016/s0012-8252(99)00011-2 van der zwaan g.j., jorissen f.j., de stigter h.c. (1990) the depth dependency of planktonic/ benthic foraminiferal ratios: constraints and applications. marine geology, 95(1), 1-16. doi: 10.1016/0025-3227(90)90016-d van morkhoven f.p.c.m. (1962) post-palaeozoic ostracoda. their morphology, taxonomy, and economic use. elsevier publishing company, amsterdam, 1, pp. 234. vellinga m., wood r.a. (2002) global climatic impacts of a collapse of the atlantic thermohaline circulation. climatic change, 54(3), 251-267. doi: 10.1023/a:1016168827653 yassini i. (1969) ecologie des associations d’ostracodes du bassin d’arcachon et du littoral atlantique. bull. inst. géol. bassin d’aquitaine, 7, pp. 316. 83 paleoenvironmental reconstruction on late calabrian stage sediments from the belice valley (southwestern sicily italy) based on ostracoda ms. received: may 3, 2022 revised: may 9, 2022 accepted: july 7, 2022 avaiable online: august 1, 2022 84 ojs 615 perez et al def3 figsbarate.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 35 (2), 2022, 135-155 1. introduction marine isotope stage (mis) 3 is recognized to be a chronological stage (ca. 60-30 ka) characterized by rapid climatic shift. this variability is associated with cyclical and sudden fluctuations in greenland temperatures called dansgaard-oeschger (d/o) events, which have led to episodes of iceberg detachment in the north atlantic, called heinrich (hes) events, resulting in a cooling of temperatures and drying climate conditions. this rapid alternation of warming and subsequent cooling of temperatures results in a strong climatic instability, alternating temperate-humid with cold-arid phases at mid-low latitudes (heinrich, 1988; bond et al., 1993; dansgaard et al., 1993; fleitmann et al., 2009; naughton et al., 2009; fletcher et al., 2010). it is in this context that the middle to upper palaeolithic transition (mupt; ca. 50-40ka) occurred and the last neanderthals, probably facing a demographic decrease while occupying smaller and smaller areas, were replaced by the first anatomically modern humans (amhs) (higham et al., 2014; benazzi et al., 2015; hublin 2015; been et al., 2017; douka & higham 2017; but see also slimak et al., 2022) how this transition occurred is widely debated (mellars, 2006; hoffecker, 2009; higham et al., 2014; villa & roebroeks, 2014; benazzi et al., 2015; hublin, 2015; rey-rodríguez et al., 2016; greenbaum et al., 2019; timmermann, 2020). mediterranean europe, particularly the italian peninsula, is a key region for understanding the dynamics of amhs peopling and the disappearance of the neanderthals (marciani et al., 2020). italy, while allowing the dispersion of amhs along the so -called 'mediterranean route' (douka et al., 2012), has been characterised by an environmental asymmetry between the eastern adriatic side and the western tyrrhenian side; this is – and was – mainly due to the presence of two geographical barriers, the alps and the apennines mountains (badino et al., 2020). this ecological dichotomy could have played a dramatic evolutionary role by providing 'refuge' zones (columbu et al., 2020; bicho & carvalho, 2022; jones, 2022) to the last neanderthal groups. among these refuge zones, the liguria region, located on the north-western tyrrhenian coast of italy, appears to be a key area for understanding the mupt and the subsequent amhs peopling of the mediterranean europe. liguria has a very narrow territorial surface, closed from the south by the tyrrhenian sea and from the north by the alps. thanks to its orography, liguria could have largely played the role of a climatic https://doi.org/10.26382/amq.2022.08 the faunal assemblage from the riparo mochi site (balzi rossi): new insights on the mousterian-aurignacian human-environment relationship. andrea perez1, fabio santaniello1,2, ursula thun hohenstein3, stefano grimaldi1,2 1 labaaf, dipartimento di lettere e filosofia, università di trento, italy. 2 istituto italiano di paleontologia umana, anagni, italy. 3 dipartimento di studi umanistici, università degli studi di ferrara, italy. corresponding author: a. perez <andrea.perez@unitn.it> abstract: due to its geography, the liguria region represented an obligatory pathway for animals and human groups that moved along the northern mediterranean route, connecting the central italian peninsula to the south-eastern france. among the several ligurian sites yielding traces of palaeolithic human activities, riparo mochi is a key site to understand the human peopling dynamics occurred during the middle to upper palaeolithic transition (mupt). its archaeological deposit is in fact one of the most complete and well dated mupt sequences in this region. this study will contribute to increase our knowledge about the behavioural differences between the last neanderthals and the first anatomically modern humans (amhs) who inhabited the sites as well as the palaeoenvironmental changes that occurred from marine isotope stage (mis) 5 to 3. to do so, our study is focused on the zooarchaeological analysis of faunal remains coming from the mousterian (unit i), protoaurignacian (units h and g), and aurignacian (unit f) units of the site. neanderthals inhabited the site during the early phases (mis 5-4), hunting mainly cervus elaphus and other middle-large size ungulates. a great variability in the faunal spectrum is shown during the coldest phases of the mousterian. a decrease in variability is observed in the upper layers of unit h, corresponding to the first amhs occupation of the site. despite the warmer climatic conditions, a decrease in diversity of faunas is observed, maybe due to a different hunting strategy operated by the protoaurignacian occupants. red deer is still the most common prey, but hunting seems also oriented on alpine taxa, such as capra ibex. deer hunting in the protoand aurignacian economy might be highlighted by the production of antler tools founded only in the upper palaeolithic (up) layers. zooarchaeological and palaeoenvironmental data from riparo mochi shows a region characterized by an overall climatic and biological stability, reflected in the almost constant presence of certain species of large mammals during the mupt. nevertheless, the variations observed since the beginning of the up appear to be related to an economic behavioural change attributable to the disappearance of neanderthals and the arrival of amhs at the site. keywords: balzi rossi; protoaurignacian; middle to upper palaeolithic transition; thyrrenian region; zooarchaeology. 136 perez a. et al. refugium even during the coldest phases of mis 3 (negrino & tozzi, 2008; berto, 2019). likewise, geography probably made liguria an obligatory pathway for both mupt animals and human groups resulting in a bidirectional route along the east-west axis that linked italy and southern france (as also strongly suggested by the distribution of lithic raw materials; see negrino & starnini, 2003; porraz et al., 2010; negrino et al., 2016). in this paper, we will focus on the study of faunal remains recovered from the mousterian, protoaurignacian, and aurignacian layers of riparo mochi, a ligurian site which has yielded one of the most complete and well dated mupt sequences in this region (douka et al., 2012; frouin et al., 2022). this units had been investigated with a zooarchaeological approach while combining identified and unidentified bone remains together with data from previous studies (alhaique, 2000; arellano, 2004, 2009). the zooarchaeological analysis carried out on such a long sequence will contribute to the interpretation of the site by providing data about the surrounding palaeoenvironment and by defining both the behaviour and the economic choices of the huntergatherers groups during the mupt: how did the fauna and the ecosystem around riparo mochi evolved? which species were mostly hunted by neanderthals and which by amhs? which hunting adaptations were implemented by humans between the mousterian and throughout the aurignacian? answering these questions will provide a better understanding of how the continuous and rapid climate changes that occurred in liguria during mis 3 affected the region's palaeoenvironment and how human-environment interactions changed between the final mp and the beginning of the up. 2. the site riparo mochi is a rockshelter located at the base of a dolomitic limestone cliff called balzi rossi (also known as grimaldi caves), an archaeological complex with over 15 sites located in liguria (ventimiglia, italy), close to the italian-french border (fig. 1). the site was discovered by a.c. blanc and l. cardini of the istituto italiano di paleontologia umana (iipu) in 1938 and was initially excavated in the same year (blanc, 1938; see a brief history of research at the site in douka et al., 2012). the archaeological deposit is approximately 10m deep and the sequence consists of nine cultural macrounits named from i to a from bottom to top by g. laplace (1977) (fig. 2). unit i, associated with mousterian lithic industries, is the thickest unit (about 5 m) (kuhn & stiner, 1998; grimaldi & santaniello, 2014). following cardini’s fieldnotes, unit h (about 50-60 cm) is a semi-sterile layer where a mix of mousterian and protoaurignacian artifacts was found; recently, field work directed by one of us (s.g.) (grimaldi et al., 2017) shows that the upper part of unit h may represent the earliest up occupation of the site above a thin sterile layer. following these new data, it is reasonable to associate to the base of unit g the faunal remains found during the 1959 l. cardini excavations originally ascribed to unit h; even if we will maintain the distinction in tables and graphs, this hypothesis is confirmed by the striking resemblance of the features evidenced in the lithic assemblages (see details in grimaldi et al., 2014). unit g (about 50 cm) provided protoaurignacian (laplace, 1977) or early aurignacian with dufour bladelets (bietti et al., 2004) lithic assemblages. the fig. 1 geographical location of riparo mochi and other archaeological sites cited in the paper (in red). 137 the faunal assemblage from the riparo mochi site. sequence continues with unit f (about 1 m) defined as middle aurignacian (laplace, 1977) or classic aurignacian (bietti & negrino, 2007). unit e is a semi-sterile and very thin unit, with rare artefacts and faunal remains. unit d (about 1,65 m) is defined as gravettian with noailles burins (laplace, 1977) while unit c (about 55 cm) provides a final gravettian assemblage without noailles burins (palma di cesnola, 1993; santaniello & grimaldi, 2019). unit b (about 60 cm) is semi-sterile with few poor characterizable artefacts, and few bone remains. finally, the upper unit a (about 60 cm), previously defined as proto-mesolithic (laplace, 1977), is now defined as epigravettian (palma di cesnola, 1993; tomasso, 2014). 2.1. chronology previous radiocarbon dates were obtained using the acid-base-oxidation/stepped combustion (aboxsc) (higham et al., 2009, 2011; douka et al., 2012). using a bayesian statistical model built with oxcal 4.1 (bronk ramsey, 2009), it has been possible to calculate that the mousterian unit i ended between 44 and 41.8 ka cal bp (68.2%), the earliest aurignacian from the bottom of unit g was dated at 42.7 41.6 ka cal bp (68.2%), while the transition from g to f occurs between 37.3 and 36.4 ka cal bp (68.2%). gravettian unit d started at 30.5 – 30.2 ka cal bp (68.2%) (douka et al., 2012). recently, a new chronological assessment of riparo mochi’s sequence has been published on the base of both radiocarbon abox-sc and luminescence technique (frouin et al., 2022). these dates provide new information about the timing of the mupt at this site: while the bottom of the mousterian sequence starts at the beginning of mis 4 probably earlier (mis 5) the end of the mousterian is dated between 45.8-41.9 ka. 2.2. palaeoenvironmental studies palaeoenvironmental data concerning small mammals (berto et al., 2019), large mammals (alhaique, 2000; 2004; arellano, 2004; 2009; zeppieri, 2009; tagliacozzo et al., 2012), and palynological studies (renault-miskovsky, 1972), allow a first reconstruction of the sequence from the bottom to the top: unit i: small mammal data coming from the uppermost spits of this unit suggest the presence of cold wet conditions with a landscape characterized by forest fig. 2 stratigraphic profile of the riparo mochi (original unpublished drawing by a. segre 1949, modified from douka et al., 2012). 138 patches with shrubs surrounded by open and rocky areas. large fauna remains from this unit were studied only from a palaeontological perspective (arellano, 2004; 2009) depicting a wide and diversified animal spectrum, mainly composed of ungulates. according to berto et al. (2019), by grouping the artificial spits into macro groups, it is possible to obtain useful data from the variations of the fauna for palaeoenvironmental observations. at the bottom part of unit i (spits 52 to 64, a. c. blanc excavations) the abundance of cervids, wild boar, and roe deer shows a relatively humid climate. in the middle sequence (spits 37 to 46, a. c. blanc excavations), the higher presence of horse, chamois and ibex, as well as the decrease of wild boar suggests a shift towards a colder and arid climate. finally, in the upper part of the unit (spits 32 to 36, a. c. blanc excavations), the presence of dama dama suggests a milder climate. unit h-g: above unit i, a change through warmer conditions is observed in units h and g (berto et al., 2019), leading to a reduction of the forest environment and an increase of the open areas. faunal remains from the semisterile unit h are missing in the a. c. blanc excavations, while data regarding the up layers comes from alhaique (2000). to sum up, cervus elaphus is the most common taxon in unit g, followed by capra ibex. marmota marmota is also attested but, due to its different degree of fragmentation and fossilisation, which differs from other remains of the same layer, its presence is defined as intrusive (alhaique, 2000). due to the low frequency of remains recovered in the protoaurignacian level, it is difficult to integrate large faunal data into the palaeoenvironmental reconstruction. unit f: a shift to colder temperatures and a general reduction of precipitations are observed during the transition between unit g and f; small faunal and palynological data suggest the presence of sparse wooded areas without shrubs and a decrease of open meadows (renault-miskovsky, 1972; berto et al., 2019). subsequently, milder climatic conditions were observed during the evolution of unit f. large faunal remains are few but more abundant in this unit than in unit g (alhaique, 2000) cervus elaphus is still the common species in the faunal assemblage and an increase of capreolus capreolus is observed. unit e: here, while decreasing temperatures and humidity followed by an improvement of the climatic conditions has been suggested (renault-miskovsky, 1972), small mammals remains and large faunal assemblage (mainly composed of red deer remains, alhaique, 2000) are very scarce. unit d: following (berto et al, 2019), cold and dry conditions are still present in the lower stage of unit d, followed by a decrease of open environments at the final phases. large faunal remains were extensively studied by zeppieri (2009): forest fauna like deer, roe deer, and wild boar coexist together with mountain fauna like ibex, chamois, and marmot. unit c: small mammal species are comparable to the previous unit d, but a decrease of the open environments has been suggested (berto et al, 2019). the unit c is poor in large mammals remains, but cold species such capra ibex and marmota marmota are attested (alhaique, 2000). unit b-a: while no changes in the small fauna composition from unit c to unit b are reported, while an increase of temperature and a decrease of the open environment is observed in unit a, leading to a more forested environment (berto et al., 2019). here, the only available information about large faunal remains comes from the original 1938 excavation notes; the presence in unit a of remains identified as marmota marmota, capreolus capreolus, cervus elaphus and capra ibex is reported. 3. materials and methods previous zooarchaeological data from the riparo mochi allow a general assessment of the sequence but the lack of data about anthropic activities and their impact on the bone assemblages prevents more accurate interpretations. in fact, while large mammals from unit d were extensively studied by a zooarchaeological approach (zeppieri, 2009, summarized in tagliacozzo et al., 2012), the same cannot be said for the units below. nowadays, unit i was sampled and studied only from a paleontological perspective (arellano, 2004, 2009) while data from units g, f, and e (alhaique, 2000) come only from limited archaeological samples. finally, data from unit h (l. cardini 1959 excavations) are still unpublished. the aim of this paper is to fill these gaps by analyzing the whole faunal assemblages coming from the site. 3.1. the analysed faunal assemblage the analysed faunal assemblage counts a total of 41.162 remains from units e, f, g, h, and i. the remains were found during the a. c. blanc excavation campaigns (1938, 1941-2, and 1948-9), l. cardini excavation (1959), a. bietti excavations (1995-2006), and current excavations led by one of us (sg) since the 2007. a re-examination of previously studied materials (alhaique, 2000; arellano, 2004, 2009) was followed by the analysis of all other unstudied remains. as already said above, recent field work, allows to consider faunal remains from unit h likely to be in association with the protoaurignacian level found at the base of unit g; faunal remains from unit e may be seen as a homogenous sample without any internal subdivision. on the contrary, tab. 1 dating estimate made by luminescent determinations on feldspar from mousterian (unit i) and semi sterile (unit h) of riparo mochi (see detailed discussion about bayesian models in frouin et al., 2022). the subdivision in phases takes in account the variation of sedimentology and the techno-typological features of the lithic assemblages. perez a. et al. 139 the remains from the mousterian unit i have been divided into three groups named: unit i – base (ib), unit i – corpus (ic), and unit i – top (it) (tab. 1). the reason for that is to be found in a clear sedimentological variability found during the earliest excavation activities as well as in techno-typological differences found in recent studies of the lithic assemblages (see details in grimaldi et al., 2017). in sum, the middle part of the mousterian sequence in unit i (that is to say, i-corpus) suggests an environmental change, possibly corresponding to a colder/dryer landscape (blanc, 1938; laplace, 1977), presumably associated with a behavioural adaptation evidenced by the lithic production (grimaldi & santaniello, 2014). 3.2. the analytical approach taxonomic and anatomical identifications were carried out using the reference collections of the laboratory of zooarchaeology of muse (trento, italy) and of the laboratory of large vertebrate of the university of ferrara (ferrara, italy); skeletal and anatomical atlases were also used (pales & lambert, 1971, 1981; schmid, 1972; barone, 1976). undetermined remains were sorted into four weight size classes, following the criteria proposed by bunn (1986) with some adaptations related to the studied materials: (1) small-size mammals weighing >20 kg (small carnivores, lagomorpha, rodentia); (2) medium-size mammals weighing between 20 and 100 kg (capridae, small cervids, sus scrofa); (3) medium-large size mammals weighing between 100 and 300 kg (cervus elaphus, ursidae); (4) large size mammals weighing >300 kg (equidae, rhinocerontidae, alces alces, megaloceros giganteus). the remains were also arranged according to their maximum length: (1) 0 to 2,9 cm; (2) 3 to 3,9 cm; (3) 4 to 4,9 cm; (4) 5 to 5,9 cm; (5) 6 to 7,9 cm; (6) 8 to 9,9 cm; (7) 10≤ cm. quantification of the identified remains were operated using: number of remains (nr) and number of identified specimens (nisp) grayson (1984). minimal number of individuals (mni) was estimated from the observation of skeletal elements and teeth of the same laterality and osteological development (grayson, 1984; klein & cruz-uribe, 1984; lyman, 1994), minimal number of elements (mne) was counted considering the side, size and ontogeny of the elements (binford, 1984; klein & cruzuribe, 1984), minimal anatomical units (mau) (binford, 1984). %mau was calculated dividing the mau value of each element by the highest mau value of the assemblage. a percentage equal to 100% for all the body parts would imply the entire presence of a complete animal skeleton. age at death estimation was made based on the degree of dental wear and the presence of deciduous teeth, also the fusion stage of the epiphysis was considered (habermehl, 1961, 1992; silver, 1969; noddle, 1974; mariezkurrena & altuna, 1983; stiner, 1998; gipson et al., 2000; azorit et al., 2002; tomé & vigne, 2003; weinstock, 2009; geiger et al., 2016). five age groups were defined according to the degree of dental wearing: infant (animals with unworn deciduous teeth), juvenile (animals with slight to moderate worn deciduous teeth), subadult (animals with highly worn deciduous teeth or unworn permanent teeth according to the timing of dental eruption for each species), adult (animals with permanent teeth with low or moderate wear) and senile (animals with highly worn teeth). understanding variations of evenness and diversity of the faunal assemblage throughout different archaeological units, correlated with the presence of anthropic modifications and other natural events (e.g. carnivores activity, post-depositional processes, etc.), allows us to better comprehend possible human-environment interactions that occurred between the mp and up (e.g. the data might show if there was hunting activity was focused on specific animals). to evaluate the diversity of the faunal assemblage inverse simpson’s index of diversity (1/d) was calculated; this index allows to measure the diversity of the animal population (simpson, 1949) found in an archaeological site. we decided to use this index because is the most reliable when applied to a faunal assemblage as diverse as the one observed at riparo mochi (faith & du, 2018). it is also a very reliable index even for relatively small assemblages. the resulting values permit to understand the taxonomical evenness of the faunal assemblage: the lower the value, the more the faunal assemblage is dominated by a single species; on the contrary, the higher the value, the more the diversity of species in the faunal assemblage. to investigate preand post-depositional processes that occurred at the site, all specimens were examined with a 10x hand lens and with a binocular microscope. modifications of major interest were captured with a leica sd6 microscope. non-human biotic modifications made by rodents, carnivores and roots were recorded as well as abiotic modifications such as concretions, weathering, manganese oxide and trampling (behrensmeyer, 1978; lyman, 1994; fisher, 1995; blumenschine et al., 1996; domínguez-rodrigo & barba, 2006; fernández-jalvo & andrews, 2018). carnivores’ marks were classified as pits, punctures, gnawing, furrowing and digestion (fisher, 1995; domínguez-rodrigo & piqueras, 2003; domínguez-rodrigo & barba, 2006; coil et al., 2020). anthropogenic modifications observed in the assemblage includes cut-marks, percussion marks and burned remains. these traces have been documented and analysed, however their morphological characterisation, location on the skeleton and their correlation to specific carcass exploitation activities will not be treated in this study (binford, 1981; potts & shipman, 1981; shipman, 1981; shipman & rose, 1984; blumenschine & selvaggio, 1988; pickering & egeland, 2006; galán et al., 2009; vettese, 2014; vettese et al., 2017, 2020; fernández-jalvo & andrews, 2018;coil et al., 2020). finally, burnt specimens were sorted according to the colour: brown (burnt), black (carbonized) and grey-white (calcinated) (stiner et al., 1995). we also carried out a preliminary investigation to distinguish between remains truly affected by thermal alterations and remains darkened by post-depositional processes (perez et al., 2020). 4. results 4.1. the faunal assemblage the taxonomically identified specimens are 792 (nisp), belonging to 111 (mni) individuals (tab. 2). there were identified 22 taxa, mainly large mammals, the faunal assemblage from the riparo mochi site. 140 t ab . 2 n is p ( n um be r of id en tif ie d s pe ci m en s) , % n is p a nd m n i ( m in im um n um be r of in di vi du al s) o f t he fa un al a ss em bl ag e of r ip ar o m oc hi . perez a. et al. 141 and few unidentified bird bones. ungulates dominate the faunal assemblage of each unit, while carnivores are rare. lagomorpha, insectivora, and rodentia were also observed. the three phases of unit i are dominated by different species: unit ib (100 nisp, 18 mni, 11 taxa) by cervus elaphus (30% nisp, 3 mni), unit ic (71 nisp, 15 mni, 11 taxa) by equus sp. (39% nisp, 3 mni), unit it (127 nisp, 25 mni, 12 taxa) by sus scrofa (20% nisp, 3 mni) (tab. 2). a single fragmented tooth of rhinocerontidae (1% nisp, 1 mni) is only observed in ib levels, while large mammals are common in the entire unit i. bos/bison is more common in ib (20%nisp, 1 mni) and it (11%nisp, 3 mni) than in ic (6%nisp, 1 mni). on the contrary, equus sp. nisp has a peak in ic layers (39%nisp, 3 mni). medium-large size ungulates like cervus elaphus are much more abundant in ib and ic layers (tab. 2). as red deer belongs to the mediumlarge size class, its presence in the archaeological record may be underestimated. it is interesting to note that, within the unit i, antler (ib: 4 nr; ic: 1 nr; it: 8 nr) and metapodial fragments (ib: 14 nr; ic: 4 nr; it: 12 nr) of undetermined cervidae show a similar distribution to that of cervus elaphus (minor nisp in ic than ib and it). capreolus capreolus (ib: 2% nisp, 1 mni; it: 1% nisp, 1 mni) and capra ibex (ib: 6% nisp, 1 mni; ic: 11% nisp, 1 mni; it: 4%, 2 mni) are scarce, while dama dama is observed only in it (1% nisp, 1 mni). as far as weight size classes are concerned, small and medium size mammal remains are scarce; medium-large size remains are more common in ib and it and this coincides with the high presence of red deer and wild boar in the same layers; large size mammal remains are common in each phase of the unit. carnivores are rare: few remains of ursus spelaeus (ib: 3% nisp, 1 mni; it: 1% nisp, 1 mni), ursus arctos (1% nisp, 1 mni),, canis lupus (ib: 1% nisp, 1 mni; ic: 1% nisp, 1 mni; it: 2% nisp, 1 mni), and panthera sp. (ic: 1% nisp, 1 mni) are observed. lepus sp. (12%nisp, 3 mni) is present only in it, but a different preservation as well as the presence of three individuals coming from the same spits and from the same sector of the excavation, could suggest their appearance in the stratigraphy after the deposition of unit i. the fossorial nature of this animal might support this hypothesis. from the semisterile unit h (63 nisp, 12 mni, 10 taxa) it is possible to observe a variation in the faunal assemblage which will persists into the subsequently unit g (199 nisp, 18 mni, 12 taxa) and unit f (178 nisp, 15 mni, 8 taxa). in these units, large ungulates show a decrease in nisp and, in the case of equus sp. (h: 1.6% nisp, 1 mni; g: 1% nisp, 1 mni; f: 1.1% nisp, 1 mni), the reduction is remarkable (tab. 2). medium size ungulates are highly represented as in the previous unit i: cervus elaphus is the most common species in each unit (h: 36.5% nisp, 1 mni; g: 50.3% nisp, 4 mni; f: 53.4% nisp, 4 mni). also, cervids remains result noticeably well represented in unit g (78 nr) coinciding with the highest nisp observed for red deer in the entire deposit (100 nisp). it is also observed an increase of nisp of capra ibex, which is the second most abundant taxon (h: 19% nisp, 1 mni; g: 13.6% nisp, 3 mni; f: 22.5% nisp, 3 mni), while nisp of sus scrofa decreases (h: 11.1% nisp, 1 mni; g: 10.6% nisp, 2 mni; f: 9.6% nisp, 2 mni). medium size ungulates are more abundant than those observed in the lower unit: capreolus capreolus is well represented in units g and f (g: 11.1% nisp, 1 mni; f: 6.2% nisp, 2 mni) while few remains of rupicapra rupicapra (g: 0.5% nisp, 1 mni; f: 0.6% nisp, 1 mni) have been found. the abundance of red deer and roe deer in protoaurignacian /aurignacian layers could be related to the high fig. 3 inverse simpson’s index (1/d) calculated on mni for each archaeological unit of riparo mochi. tab. 3 comparison between the inverse simpson’s index (1/ d) calculated in riparo mochi and other contemporary sites of the ligurian region. both nisp and mni were used to calculate the 1/d. (a) data from holt et al. (2019). (b) data from valensi & psathi, (2004). (*) data not available. the faunal assemblage from the riparo mochi site. 142 presence in unit g and f, of numerous antlers (g: 45 nr; f: 6 nr) and metapodials fragments (g: 30 nr; f: 17 nr) identified as cervidae specimen sorted by weight size classes might reflect the distribution of nisp from units h, g, and f. medium-large size ungulate remains are the most numerous (h: 30 nr; g: 82 nr; f: 56 nr), followed by medium (h: 15 nr; g: 35 nr; f: 18 nr) and small size (h: 7 nr; g: 19 nr; f: 10 nr), while large size ungulates (h: 2 nr; g: 13 nr; f: 9 nr) decrease in number. carnivores are rare and absent in unit f. ursus spelaeus is present only in unit h (4.8% nisp, 1 mni), while ursus sp. is present in unit h (3.2% nisp, 1 mni) and unit g (0.5% nisp, 1 mni). crocuta sp. (0.5% nisp, 1 mni), canis lupus (0.5% nisp, 1 mni), and mustela sp. (0.5% nisp, 1 mni) are only present in unit g. lepus sp. from unit h (9.5% nisp, 2 mni) could be linked to the analogous remains recovered in the top of unit i as both seem to share different taphonomic characteristics from those of the fossil record; moreover, they come from the same excavation sector. two remains of marmota marmota (h: 1.6% nisp, 1 mni; g: 0.5% nisp, 1 mni) and a mandible of erinaceus sp (1% nisp, 1 mni). from unit g and f are observed. at last, few specimens (157 nr) come from the semisterile unit e. among the ungulates, only cervus elaphus (58.6% nisp, 3 mni), capra ibex (12.1% nisp, 1 mni), rupicapra rupicapra (1.7% nisp, 1 mni), and capreolus capreolus (24.1% nisp, 1 mni) are present (tab. 2). cervids remain the most common ungulate taxa, while carnivores are scarce with the presence of ursus sp. (1.7% nisp, 1 mni) and canis lupus (1.7% nisp, 1 mni). weight size classes remains are differently distributed: medium size mammals (33 nr) are the most abundant followed by small size (17 nr), mediumlarge (4 nr) and large size (1 nr) are scarce. mni value was used to calculate 1/d, lepus sp. and marmota marmota are not included as they both appear to be intrusive. the graph in figure 3 shows how mousterian faunal spectrum is characterized by a high diversity of taxa. unit h and g, have a similar lower 1/d value (fig. 3, tab. 3). in the aurignacian layers (unit f) a decrease in diversity is observed, while in unit e the diversity drops drastically. on the light of this, a decrease of faunal variety seems to happen during the up units, especially in unit f. 4.2. mortality profile a total of 111 individuals were identified in the site (tab. 4). young individuals are observed only in unit i. four juvenile individuals of sus scrofa were identified: in ib, two juveniles by two left dp4 (age estimation 5-7 weeks according to silver 1969; habermelh, 1961); in ic, one individual by an unfused metatarsal distal epiphysis, and in it, one individual from a left dp3. a new-born individual of equus sp. were identified from a left dp3 in ic. senile individuals are observed in unit h and unit g, respectively an old capreolus capreolus, identified from a high worn molar, and a cervus elaphus old individual identified from a marked worn m1. the other taxa show only adult individuals. cervus elaphus appears to be the species with the most number of individuals (19) across the entire stratigraphy (tab. 4). in units g and f the mni of the red deer increases slightly (tab. 4) and antler fragments are present. the only observable variation is the presence of a senile individual in unit g (tab. 4). despite the presence of undetermined cervids antler fragments in unit i, g and f, it was not possible to define whether they were antlers obtained by hunting the animal or simply collected. for this reason, it is currently not possible to hypothesise a hunting seasonality for cervus elaphus. however, it must be taken into account that the undetermined antler fragments may have betab. 4 age classes for each taxon of riparo mochi. infant (i), juvenile (j), sub-adult (sad), adult (ad), senile (s). perez a. et al. 143 longed to capreolus capreolus (from unit i to e), dama dama and alces/megaloceros (only in unit i). sus scrofa is the second ungulate with the highest number of total individuals (17 mni). it is noted that throughout the mousterian sequence there is a large presence of individuals (12 mni), four of which are juvenile. we observed that, starting from unit h, its mni value decreases (tab. 4). considering that the wild boar can give birth twice a year when conditions are optimal (mauget, 1981), we could theorise that during the deposition of unit i the regional environmental conditions have been milder compared to the upper levels. to strenghten this hypothesis, we observed similar variations in mnis of equus sp., bos primigenius, bison priscus and the genus bos/bison sp.: these appear to have higher values in the mousterian levels than in the aurignacian levels (tab. 4). in particular equus sp., which in unit i has a total mni equal to 8, one of which is an infant, reduces its mni to a single individual in units h, g and f. this decrease is also observable in the nisp (tab. 2). conversely, an increase in the mni of capra ibex is observed in units g and f. this decrease in the mni of species wich inhabitate forests and/or open environments, such as equus sp. and bos/bison and the increase in the mni of mountain species such as the ibex, might suggests a change in the environmental conditions and/or in human hunting strategies that occurred between the mp (unit i) and the up (unit g and f), reflected in the composition of the faunal spectrum. 4.3. general taphonomy except for unit e, ib, and ic which have few remains, the whole assemblage is highly fragmented (fig. 4). bone fragments smaller than 2.9 cm represent the 87% of the total remains. whole specimens are the 0.3% (140 nr) of the total, which are primarly represented by small fat bearing bones, such as sesamoids, carpals, tarsals, phalanges, and metapodial of small fauna, in association with isolated teeth (fig. 5); low density bones as ribs, scapulae, and vertebras are rare. we have divided them according to the weight size of the species to which they belong. the remains belonging to small animal (small carnivores, rodents, birds) are primarily represented by short limb bones like tarsals and phalanges. those concentrated in it and h (fig. 5) are almost exclusively determined as lepus sp. the scarcity fig. 4 percentage of fragmented remains (nr%) for each unit of riparo mochi sorted in seven classes according to their length. fig. 5 percentage of whole remains divided according to the animal size in each unit of riparo mochi. small size (small carnivores, lagomorpha, rodentia), medium size (capridae, small cervids, sus scrofa), medium-large size (cervus elaphus, ursidae), large size (equidae, rhinocerontidae, alces alces, megaloceros giganteus). the faunal assemblage from the riparo mochi site. 144 or absence of whole remains belonging to small animals in the other units it might confirm the intrusive nature of lepus sp. in these levels. overall, the skeleton of small faunas is mainly represented by fore and hindlimb in units it and h (fig. 6), while the cranial portion is the only represented part in f. isolated teeth are rare and only observed in ic. the scarce representation of small faunas throught the stratigraphic sequence could be the result of a heavier fragmentation of these elements. medium (caprids, canids, suids) and medium-large (red deer, ursids) size animal bones share a similar distribution (fig. 5, fig. 6). for both the size classes whole remains are mainly represented by isolated teeth, small fat bearing bones such as carpals, tarsals, sesamoid and falanges (fig. 5). the major variations in the stratigraphy are observed in ic, where theeth are the only whole specimens, and in it in which the representation of short limb bones increases (fig. 5). this variation is observable also in the representation of the anatomical parts (fig. 6). the cranial skeleton of both size classes starts to decrease in unit h, reaching its minimum in unit fig. 6 percentage of remains belonging to a specific anatomical portion in each unit of riparo mochi. data are divided according to the size of the animal: small size (small carnivores, lagomorpha, rodentia), medium size (capridae, small cervids, sus scrofa), medium-large size (cervus elaphus, ursidae), large size (equidae, rhinocerontidae, alces alces, megaloceros giganteus) fig. 7 percentage of remains bearing concretions, manganese oxide and root-etching in each unit of riparo mochi. perez a. et al. 145 g (less than 50% of the total nr%). also the axial skeleton, rarest than the other anatomical parts, increase is frequency in the up levels. a different variation is observed in unit e where the representation of the cranial skeleton is highest for the medium size animals than for the medium-large (fig. 6). lastly, whole remains of large size animals are composed by isolated teeth concentrated in ib and ic and sesamoid in f (fig. 5). the cranial skeleton, mainly represented by teeth, is the most abundant anatomical part in every archaeological unit, with the exception of unit e (fig. 6). cranial skeleton of large faunas presents a decrease in unit h and elements of the forelimb and hindlimb increase in number in unit gf. is also observed a higher presence of the axial skeleton, which becomes the only anatomical portion present in unit e. medium, medium-large and large sized remains seem to have been subject to a similar attrition due to intense fragmentation processes. it cannot be excluded that the skeletal representation are also due to anthropic activity, which may have concentrated on the intentional breakage of bones. traces of percussion are in fact the most attested anthropic traces in the entire fig. 8 remains showing anthropic and carnivore modifications. a: capreolus capreolus metatarsal with scraping marks on its diaphysis side (unit i). b: cervus elaphus humerus with impact point on its diaphysis (unit g). c: an unidentified long bone fragment corroded by carnivore digestion (unit i). d: unidentified long bone diaphysis of a medium-large size mammal with multiple cut-marks (unit f). e: cervus elaphus metacarpal fragment with a single cut-mark (unit f). the faunal assemblage from the riparo mochi site. 146 assemblage, especially on long bones of medium-large size animals (tab. 5). furthermore, the presence of all the anatomical portions might suggest a complete transport of the carcasses, which occurred continuously between mp and up. the preservation of bone surfaces is low as a high presence of concretions (fig. 7), which affects almost half of the total remains in units i and h (ib: 58%, ic: 48%, it: 49%, h: 49%), is observed; it highly increases from unit g to unit e (g: 87%, f: 93%, e: 98%). manganese dendrites are observed in each unit, with a major abundance in units i, g, and e. root-etching is scarce except in unit e, but, like the manganese oxides, the scarce amount of remains in this unit could lead to an overrepresentation of the data. carnivore modifications are present in units i and g but they are extremely rare and observed only on the 0.03% of remains (tab. 5, fig. 8). pits and scores are the main alteration made by carnivores and only one remain shows digestion marks. among the identified taxa, a cervus elaphus metacarpal and a cervidae metapodial show carnivore modifications, while other nine remains belong to medium-size mammals. no rodent marks are observed. traces of anthropogenic activity on animal remains are rare but present throughout the stratigraphic sequence (tab. 5). among the identified species, the most exploited remains belong to the cervus elaphus, whose remains show few percussion marks and cut marks. the exploitation of red deer appears to be continuous, from the mousterian to the early aurignacian. only in unit i, rare anthropogenic modifications are observed on capreolus capreolus and sus scrofa remains. nevertheless, along the entire site sequence, anthropic modifications are mostly observed on diaphysis of medium-large unidentified mammals. burnt remains are abundant in all units, predominantly indeterminate bone fragments. however, there are few remains of bos/bison, cervus elaphus, capreolus capreolus, capra ibex, sus scrofa and lepus sp. showing traces of combustion. 4.4. skeletal representation skeletal representation data covers only those species with abundant remains, throughout the whole stratigraphy, which are not uniquely teeth. those wellrepresented species are bos/bison sp., cervus elaphus, capreolus capreolus, capra ibex and sus scrofa. one can observe how cranial elements are frequent throughout the sequence, especially mandibles, except for units ic and h. such abundance is coherent with the high number of cranial elements and isolated teeth in the entire faunal assemblage (fig. 6). the axial skeleton is almost entirely absent (fig. 9), with scarcely frequent ribs from bos/bison sp. (g: 8% mau) and cervus elaphus (g: 2% mau; f: 2% mau; e: 2% mau) in the up __________________________________________ >>>>> tab. 5 anthropic and carnivore modifications observed on the fossil assemblage. cut-mark (cm), percussion-mark (pm), cutmark + percussion-mark (cm+pm), burned bones (b), calcinated bones (c), percentage of anthropic modifications (%ant), carnivore modifications (car), percentage of carnivore modifications (%car). perez a. et al. 147 per levels, and totally absent for unit i and h. the limb skeleton is well represented: the hindlimb, specifically the tibia and metapodials, are quite frequent throughout the whole stratigraphy. the main variation of the skeletal representation is in between and mp and up. in fact, in unit h, the number of limb elements represented in the skeletal profile increases, with a high frequency of hindlimb bones, such as tibias, tarsals, phalanges. the increase in the latter could be related to a general increase of short limb bones observed already in unit it (fig. 5). in unit g and f there is a higher number of elements of the proximal forelimb, such as scapula, humerus and radio-ulna, as well as of the hindlimb, such as tibia and astragalus, and a high number of both core and hind metapodials. large sized animals, as the bos/bison, are represented by radio-ulna, femur and tibia, while for the medium-large and medium animals, like red deer, ibex, wild boar and roe deer, we have every limb element, in particular the forelimbs. this data, together with the scarcity of elements of the axial skeleton, might suggest a differentiated transport and exploitation of preys defined by their weight size. nevertheless, the high frequency of mandibles (fig. 9) and the presence of all anatomical parts in the whole archaeological assemblage (fig. 6), suggests that the carcass was transported as a whole inside the site. in this case, the absence of fragile and low-density bones, such as vertebrae, ribs and cranial bones may be due to intense taphonomical processes which have caused a high fragmentation of these elements (fig. 4). 5. discussion 5.1. faunal variability and palaeoenvironmental scenario the zooarchaeological data allow a better interpretation of a possible environmental context during which the riparo mochi archaeological deposit was formed. generally speaking, the fauna spectrum all along the riparo mochi sequence from the mp to the initial up seems to reflect the presence of a landscape characterized by a high variety of ecosystems (fig. 3; tab. 3). 5.1.1. unit i base: the earliest phase of the mousterian of riparo mochi is characterised by a great faunal diversity (fig. 3). the copresence of species preferring open grassland environments such as bison priscus and equus sp. (mcdonald, 1981; berger, 1986), or ones more akin to temperate forest environments such as capreolus capreolus (danilkin, 1995), as well as alpine taxon such as capra ibex, probably reflects great variety of habitats present in the region surrounding the site at the end of mis 4. carnivores are rare, but the presence of coprolites from ib and ic (spits from 39 to 64) and undetermined remains with traces of digestions in unit it (tab. 5) could indirectly suggest a occupation of the site by large predators such as hyenas (tab.2). the presence of young sus scrofa individuals, which are largely present in ib, as well as throughout the entire mousterian sequence (tab. 4), could reflect a high environmental richness. considering that this species can breed twice a year under favourable conditions (mauget, 1981), we could suggest a high presence of wild boar at regional level, whose high reproductive rate could have been favoured by milder environmental conditions which fig. 9 percentage of minimum anatomical units of bos/bison, cervus elaphus, capreolus capreolus, capra ibex and sus scrofa in each unit of riparo mochi. the faunal assemblage from the riparo mochi site. 148 seem to have been maintained in liguria even in periods of general cooling and climatic dryness (negrino and tozzi, 2008; berto et al., 2019). the faunal assemblage from ib fits reasonably well into the ligurian archaeozoological palimpsest straddling mis 4 and the beginning of mis 3. sites such as madonna dell’arma, arma delle manie, santa lucia superiore and san francesco (valensi & psathi, 2004), where anthropogenic accumulation is widely attested, are also characterised by a similar level of faunal diversity (tab. 3). corpus: the main variation observed in the mousterian levels is in ic. here, several features allow to detect an environmental change, towards dryer and colder conditions (tab. 3). in fact, it is shown an abrupt increase of equus sp. and a general decrease in the presence of other species; the absence of roe deer, of which the primary habitat is forest clearings, hedges, and woodland edges (mauget, 1981; danilkin, 1995), may support the hypothesis of a colder and less tree-covered environment during this phase. finally, the presence of alces/megaloceros could also reflect colder environmental conditions. due to its chronology, this part of the mousterian sequence seems to fall into a the greenland stadial 15.1 (rasmussen et al., 2014) which could have led to a decrease in temperature and a consequent regression of temperate taxa. unfortunately, no palaeoecological nor archaeobotanical data are available neither for ic nor for ib phases. as in the previous mousterian layers, hyena coprolites have been found and the presence of carnivores such as panthera sp., a high presence of sus scrofa, and a high mni 1/d value, may be a proxy for a wide biodiversity (tab. 3). top: similarly, to what happens in ib as well as palaeoenvironmental data also suggested (renaultmiskovsky, 1972; berto et al., 2019), the region surrounding the site was characterized by a patchwork of habitats of open and forested areas with a cold-humid environment during the final phase of the mousterian at riparo mochi. the inverse simpsons’ index is the highest for the mousterian unit (fig. 3), showing a wide diversity in the faunal composition. moreover, this diversity has been also recognized in the mousterian level “m” of the nearby site of riparo bombrini (holt et al., 2019), where a nisp 1/d appears to be very similar to what has been found in it of riparo mochi (tab. 3). this data confirms how the region's great environmental variety persists during the coldest climatic phases. 5.1.2. unit h as far as the assemblage coming from cardini’s unit h is concerned as a whole, it is worth to mention that few remains were clearly identified showing few anthropogenic modifications. generally speaking, the data coming from this unit are very close to the later unit g (see below). a general decrease in the faunal spectrum diversity is observed (fig. 3), particularly with species such as equus sp. and sus scrofa (tab. 2). similarly, this evidence is also present in the semisterile 'ms' levels of riparo bombrini (holt et al., 2019) (tab. 4). other studies show a rise in temperatures and a change in the rainfall regime which should have led to a reduction in forest cover in favour of an expansion of open meadows (berto et al., 2019). as this change is also observed in the later unit g, it is therefore difficult to determine whether the variation in the faunal spectrum observed at the beginning of the protoaurignacian level was mainly caused by a change in environmental conditions or by a change in hunting strategies that occurred with the arrival of the first amhs at the site. 5.1.3. unit g as seen in unit h, the large fauna assemblage of the protoaurignacian unit g has a minor diversity than the unit i (fig. 3). variability between the two units is mainly represented by the presence of rupicapra rupicapra, by a greater presence of cervus elaphus and capra ibex as well as an increase in the number of anthropogenic modifications in unit g. as shown by small fauna studies (berto et al., 2019), the general warming and reduction of forestall cover seen in unit h is still in progress during the formation of unit g. the lower diversity of the faunal spectrum (fig. 3, tab. 3) as well as the decreasing presence of equus sp. and sus scrofa remains (tab. 2), may testify a mutation of the biodiversity of the region, maybe characterized by more presence of alpine faunas (as suggested by the higher frequence ibex and chamois remains). as seen in the oldest archaeological units, the remains of carnivores are still rare; moreover, the absence of coprolites from these levels could indicate a reduced frequentation of the site by hyenas. 5.1.4. unit f no major changes are observed in the species represented in unit f. although small mammals and palynological data indicate a colder and drier environment in unit f than in unit g (renault-miskovsky, 1972; berto et al., 2019), the representation of species appears constant through the up sequence. nevertheless, the faunal assemblage shows an increasing loss of diversity, which reaches the lowest value in unit f (fig. 3). another interesting value is the lack of carnivores (tab. 2) that could be speculatively explained by a more intense human occupation, which is also supported by a higher number of anthropogenic modifications observed on bone remains (tab. 5). cervus elaphus, capra ibex, and capreolus capreolus are the main taxa found in the early aurignacian unit. the coexistence of ibex and roe deer species that frequent alpine grassland and wooded areas, respectively may indicate the persistence of different environments, relatively close to each other, in the riparo mochi region. however, the presence of chamois, already found in unit g, may reflect a greater presence of mountain faunas in the up units than seen in the mp unit. 5.1.5. unit e given the ephemeral nature of this deposit and the scarce presence of bone remains, unit e may have been formed by an intrusion of materials from overlying and underlying units. it should be noted that gravettian unit d has similar faunal data to units e and f (tagliacozzo et al., 2012). in fact, the faunal spectrum of the gravettian levels continues to be dominated by cervus elaphus (37.69% nisp), and there is a similar proportion of capra ibex remains (19.59% nisp) to that perez a. et al. 149 observed for the ibex in unit f (22.5% nisp). unlike the older units, carnivores are present with a greater number of species: fox, wild cat and lynx but also panthera pardus and crocuta crocuta. the faunas of the gravettian unit continue to reflect a mosaic of environments, in which there is a copresence of forest species such as deer and wild boar and 'cold' or alpine environment species such as chamois, ibex and marmot (tagliacozzo et al. 2012), confirming that the climatic conditions of the region remain mild even with the cold and dry conditions present in the lower stage of unit d (berto et al. 2019). 5.2. human-faunal interaction 5.2.1 middle palaeolithic despite the presence of hyena coprolites during the ib and ic phases, and the rare traces of digestion and fracturing by carnivores, human groups certainly acted as the main agent for the accumulation of bone remains of the site. unfortunately, the concretions as well as the high rate of bone fragmentation hamper a clear recognition of the anthropogenic modifications, making archaeozoological interpretation difficult. thus, traces of faunal exploitation are rare all along the mousterian sequence of the riparo mochi. without considering the abundant burnt bone fragments, anthropogenic traces are predominantly percussion marks; only one scraping mark, from the deeper spits, was recorded (tab. 5). the skeletal representation observed in unit i seems to indicate the arrival of the whole carcass at the site. both medium, medium-large and large animals (fig. 6) present anatomical elements from all anatomical portions, with a large presence of the cranial skeleton. regarding the skeletal frequency of the most represented species (fig. 9), we see a lower presence of anatomical elements in the ic level compared to ib and it. thus, there does not appear to be a selection of specific anatomical elements in all three mousterian phases. the neanderthals who frequented riparo mochi had at their disposal a wide variety of prey, from large game such as horse to smaller game such as wild boar, the latter being extremely abundant according to the mni in unit i (tab. 4). it does not seem to be possible to extrapolate data on a seasonal occupation of the site. the mere presence of young boar individuals (tab. 4) does not allow to define a seasonality of death due to the animal's biological cycle, which doesn't give birth in a single time of the year (mauget, 1981). in addiction, the sole presence of the fragments of cervid antlers, although distributed throughout the sequence, did not allow a seasonality of occupation of the site to be defined. exploitation seems have a focus on cervus elaphus, whose remains show the highest number of impact marks observed in the mousterian unit. further impact marks are observed mainly on the long bones of medium-large size mammals. as red deer belong to this size class, its exploitation by neanderthals may be underestimated. the high presence of cervus elaphus in the archaeological assemblage is a very common feature of middle and upper pleistocene sites in the ligurian region. in coeval sites such as riparo bombrini, arma delle manie, and san francesco, red deer is the main species among ungulates (isetti, 1961; valensi, 2000; psathi, 2003; valensi & psathi, 2004; holt et al., 2019) (fig.1). a possible reason for this could be its high environmental adaptability, with a mix-feeder diet, plastic in its choice of habitats (straus, 1981; sommer et al., 2008), and the better “economical return” that this species could offer in terms of quality and quantity of the materials obtained, ease of hunting and/or transport (valensi & psathi, 2004). the neanderthal economy at riparo mochi therefore seems to have focused on big game, a factor that seems to be common to coeval sites of ligurian region. we also note the paucity of exploitation of small faunas such as birds or rodents; although it cannot be ruled out that such remains have not survived due to the intense taphonomic processes that characterise the site, this scanty evidence could be speculatively related to a possible distinctive cultural-economic difference between the tyrrhenian and po-adriatic regions. several sites of adriatic region provide evidence of the exploitation of both avifauna (fiore et al., 2004, 2016; peresani et al., 2011; romandini et al., 2014) and small fauna (alhaique et al., 2004; romandini et al., 2018). currently, only at the french pié-lombard site (pelletier et al., 2019), geographically close to riparo mochi and integrated into the ligurian-provençal region, provided mousterian levels dated to the mis 5-4 transition showing the exploitation of both avifauna and small mammals (specifically oryctolagus cuniculus). 5.2.2. upper palaeolithic the beginning of the up is marked by an increase of anthropogenic modifications that are mainly concentrated on the long bones of medium-large sized mammals; determined remains of cervus elaphus bearing cut -marks and percussion marks are also present and, similarly to unit i, the exploitation of red deer could be underestimated, a feature which seems to persist during the up. it was not possible to determine a seasonality of occupation of the site due to the absence of juvenile individuals (tab. 4) or antler fragments still in connection with the skull. compared to the earlier mousterian unit, the up units display a more diversified and abundant skeletal profile (fig. 6, fig. 9). as in the mp, the skeleton appears to be complete, suggesting that the carcasses entered the site as whole (fig. 6). unlike the mp, elements of the limbs are more abundant. the skeletal representation of ungulates such as cervus elaphus, capra ibex and capreolus capreolus, shows a higher frequency of specific elements such as tibiae and metatapodials (fig. 9). in general, the posterior appendicular skeleton is highly represented, suggesting a selection of specific anatomical elements or a higher degree of preservation of these. the change in faunal composition from unit i to unit h-g may be linked to a shift of anthropogenic activity. in fact, if we accept the presence of a sterile layer within the former unit h, see grimaldi et al. (2014), the variation in the faunal spectrum that occurred in unit g may be mainly caused by a change in hunting strategies linked to the arrival of the earliest amhs, rather than by climatic and environmental variations. for this reason, it cannot be excluded that the general increase in the number of remains belonging to cervids (red deer, roe deer or other cervids) is evidence the faunal assemblage from the riparo mochi site. 150 of a selection of prey which becomes more evident in unit f where the variety of the faunal spectrum is lower. to support this hypothesis, the finding of antler industry in early aurignacian unit f (tejero & grimaldi, 2015), specifically related to the production of split-based points, should be remarked. the production of such tools, namely hunting-oriented specialised tools, may have largely influenced the selection of prey, also useful for obtaining the non-lithic raw-material. in addition, the increase of capra ibex and capreolus capreolus at the expense of species such as equus sp. and sus scrofa, which are widely present in the mousterian levels, could testify the change in hunting strategies that occurred during the up. interestingly, from unit g to unit e, more distinctly alpine taxa, such as capra ibex and rupicapra rupicapra, are more abundant than in unit i. the amhs inhabitants of riparo mochi may have preferred to hunt prey at higher altitudes than the neanderthals, probably facilitated by a milder climate that made more accessible the mountainous areas close to the site. evidence of hunting focused on alpine species can also be observed in the upper unit d. although surface preservation is as 'bad' as that observed in the unit i to e sequence, the gravettian levels have yielded numerous traces of exploitation of ungulates such as red deer and ibex that seem to suggest the persistence of exploitation of mountain faunas (tagliacozzo et al., 2012) cervus elaphus and capra ibex are the most exploited species, together with other ungulates such as capreolus capreolus, rupicapra rupicapra and bos primigenius. unlike what was observed in the unit i-e sequence, in unit d anthropogenic traces are found on the remains of carnivores such as vulpes vulpes, felis silvestris and lynx lynx. these traces are attributable to skinning activities and could indicate a further variation in the hunting spectrum also linked to the obtaining of specific resources. a more in-depth study of the anthropic exploitation of preys in the aurignacian levels will shed light on possible similarities and divergences between unit f and unit d. 6. conclusions this research allows a more specific environmental contextualization of riparo mochi throughout the formation of the mousterian, proto-aurignacian and aurignacian archaeological deposits. data from the riparo mochi fit well with the palaeoenvironmental framework today available for the liguro-provençal arc during the mis 4 and 3. despite rapid climatic fluctuations, the region is characterized by more temperate environmental conditions during the mupt, favouring the persistence of a mosaic of environments and relevant biodiversity of large fauna. this heterogeneity can be observed as early as the end of mis 5 (unit i-base) and persists until mis 3 (unit f). during the earliest phases of the mousterian, the site was also occasionally occupied by carnivores, as evidenced by the finding of hyena coprolites. the neanderthals that inhabited riparo mochi, although the presence of a wide range of prey, hunted mainly medium-large ungulates, in particular red deer. with the arrival of amhs, attested since the top of unit h base of unit g, a change in the composition of the faunal spectrum is observed with a decrease in diversity. nevertheless, cervus elaphus remains the most hunted species; this could be tentatively related to an ecological adaptation of the hunters, probably linked also to the production of antler tools. future studies such as a fully developed functional analysis linking lithics and butchering marks, palynological analysis, malacological and microwear dental studies, will be useful for a wider palaeoenvironmental contextualization and will provide a better understanding of the different human-environment interactions that occurred in the archaeological units at the riparo mochi. author contributions: a.p. carried out the riparo mochi zooarchaeological study as part of his “the exploitation of animal resources in the upper pleistocene in northern italy: reconstruction of hunting strategies in the middle and upper palaeolithic sequence at riparo mochi (balzi rossi) and riparo tagliente (monti lessini)” phd project which was designed and supervised by s.g. and u.t.h.; all authors wrote the paper; riparo mochi research project is directed by s.g under the permission of the italian ministry of culture. acknowledgments the research was funded by the phd course “european cultures: environment, contexts, histories, arts, ideas” of the department of humanities, university of trento (italy). authors acknowledge the laboratory of zooarchaeology of muse (trento, italy) and the laboratory of large vertebrate of the university of ferrara (ferrara, italy) for providing facilities and the access to their paleontological reference collections. references alhaique f. (2000) analisi preliminare dei reperti faunistici rinvenuti nei livelli del paleolitico superiore di riparo mochi (balzi rossi): scavi 1995-1996. in atti del 2°convegno nazionale di archeozoologia: asti, 14-16 novembre 1997, 125-130. alhaique f., bisconti m., castiglioni e., cilli c., fasani l., giacobini g., grifoni r., guerreschi a., iacopini a., malerba g., peretto c., recchi a., rocci ris a., ronchitelli a., rottoli m., thun hohenstein u., tozzi c., visentini p., wilkens b. (2004) animal resources and subsistence strategies. collegium antropologicum, 28 (1), 23-40. https://hrcak.srce.hr/en/4885 arellano a.a. (2004) les grands mammifères des niveaux moustériens de l’abri mochi (grottes de grimaldi, vintimille, italie). fouilles de 1949. quat. nov. vii, 7, 139-157. arellano a.a. (2009) les grands mammifères des niveaux moustériens de l’abri mochi (grottes de grimaldi, vintimille, italie). fouilles de 1949. bulletin du musée d’anthropologie préhistorique de monaco, 49, 29-39. azorit c., analla m., carrasco r., calvo j.a., muñozcobo j., de jaén u. (2002) teeth eruption pattern in red deer (cervus elaphus hispanicus) in southern spain. anales de biología, 8. badino f., pini r., ravazzi c., margaritora d., arrighi s., perez a. et al. 151 bortolini e., figus c., giaccio b., lugli f., marciani g., monegato g., moroni a., negrino f., oxilia g., peresani m., romandini m., ronchitelli a., spinapolice e.e., zerboni a., benazzi s. (2020) an overview of alpine and mediterranean palaeogeography, terrestrial ecosystems and climate history during mis 3 with focus on the middle to upper palaeolithic transition. quaternary international, 551, 7-28. doi: 10.1016/j.quaint.2019.09.024 barone r. (1976) anatomie comparée des mammifères domestiques. vol. 1, ostéologie, vigot. been e., hovers e., ekshtain r., malinski-buller a., agha n., barash a., mayer d.e.b.-y., benazzi s., hublin j.-j., levin l., greenbaum n., mitki n., oxilia g., porat n., roskin j., soudack m., yeshurun r., shahack-gross r., nir n., … barzilai, o. (2017) the first neanderthal remains from an open-air middle palaeolithic site in the levant. scientific reports, 7(1), 2958. doi: 10.1038/s41598-017-03025-z behrensmeyer a.k. (1978) taphonomic and ecologic information from bone weathering. paleobiology, 4(2), 150-162. benazzi s., slon v., talamo s., negrino f., peresani m., bailey s.e., sawyer s., panetta d., vicino g., starnini e., mannino m.a., salvadori p.a., meyer m., paabo s., hublin j.j. (2015) the makers of the protoaurignacian and implications for neandertal extinction. science, 348(6236), 793-796. doi: 10.1126/science.aaa2773 berger j. (1986) wild horses of the great basin: social competition and population size. university of chicago press. berto c., santaniello f., grimaldi s. (2019) palaeoenvironment and palaeoclimate in the western liguria region (northwestern italy) during the last glacial. the small mammal sequence of riparo mochi (balzi rossi, ventimiglia). comptes rendus palevol, 18(1), 13-23. doi: 10.1016/j.crpv.2018.04.007 bicho n., carvalho m. (2022) peninsular southern europe refugia during the middle palaeolithic: an introduction. journal of quaternary science, 37(2), 133-135. doi: 10.1002/jqs.3410 bietti a., boschian g., crisci g.m., danese e., de francesco a.m., dini m., fontana f., giampietri a., grifoni r., guerreschi a., liagre j., negrino f., radi g., tozzi c., tykot r. (2004) inorganic raw materials economy and provenance of chipped industry in some stone age sites of northern and central italy. collegium antropologicum, 28(1), 4154. bietti a., negrino f. (2007) l’aurignacien et le gravettien du riparo mochi, l’aurignacien du riparo bombrini: comparaisons et nouvelle perspectives. 6. binford l.r. (1981) bones: ancient men and modern myths. academic press,84, 2. doi: 10.1525/aa.1982.84.2.02a00370 binford l.r. (1984) faunal remains from klasies river mouth. academic press. blanc a.c. (1938) nuovo giacimento paleolitico e mesolitico ai balzi rossi di grimaldi. rendiconti dell’accademia nazionale dei lincei 28, vi(3-4), 107-113. blumenschine r.j., marean c.w., capaldo s.d. (1996) blind tests of inter-analyst correspondence and accuracy in the identification of cut marks, percussion marks, and carnivore tooth marks on bone surfaces. journal of archaeological science, 23(4), 493-507. doi: 10.1006/jasc.1996.0047 blumenschine r.j., selvaggio m.m. (1988) percussion marks on bone surfaces as a new diagnostic of hominid behaviour. nature, 333(6175), 763-765. bond g., broecker w., johnsen s., mcmanus j., labeyrie l., jouzel j., bonani g. (1993) correlations between climate records from north atlantic sediments and greenland ice. nature, 365(6442), 143147. doi: 10.1038/365143a0 bronk ramsey c. (2009) bayesian analysis of radiocarbon dates. radiocarbon, 51(1), 337-360. doi: 10.1017/s0033822200033865 bunn h.t. (1986) patterns of skeletal representation and hominid subsistence activities at olduvai gorge, tanzania, and koobi fora, kenya. journal of human evolution, 15(8), 673-690. doi: 10.1016/s0047-2484(86)80004-5 coil r., yezzi-woodley k., tappen m. (2020) comparisons of impact flakes derived from hyena and hammerstone long bone breakage. journal of archaeological science, 120, 105167. doi: 10.1016/j.jas.2020.105167 columbu a., chiarini v., spötl c., benazzi s., hellstrom j., cheng h., de waele j. (2020) speleothem record attests to stable environmental conditions during neanderthal modern human turnover in southern italy. nature ecology & evolution, 4(9), 1188-1195. doi: 10.1038/s41559-020-1243-1 danilkin a. (1995) behavioural ecology of siberian and european roe deer. springer netherlands. books.google.it/books?id=ugpa5siepr4c dansgaard w., johnsen s.j., clausen h.b., dahl-jensen d., gundestrup n.s., hammer c.u., hvidberg c.s., steffensen j.p., sveinbjörnsdottir a.e., jouzel j., bond g. (1993) evidence for general instability of past climate from a 250-kyr ice-core record. nature, 364(6434), 218-220. doi: 10.1038/364218a0 domínguez-rodrigo m., piqueras a. (2003) the use of tooth pits to identify carnivore taxa in tooth-marked archaeofaunas and their relevance to reconstruct hominid carcass processing behaviours. journal of archaeological science, 30(11), 1385-1391. doi: 10.1016/s0305-4403(03)00027-x domínguez-rodrigo m., barba r. (2006) new estimates of tooth mark and percussion mark frequencies at the flk zinj site: the carnivore-hominidcarnivore hypothesis falsified. journal of human evolution, 50(2), 170-194. doi: 10.1016/j.jhevol.2005.09.005 douka k., grimaldi s., boschian g., higham t.f.g. the faunal assemblage from the riparo mochi site. (2012) a new chronostratigraphic framework for the upper palaeolithic of riparo mochi (italy). journal of human evolution, 62(2), 286-299. doi: 10.1016/j.jhevol.2011.11.009 douka k., higham t. (2017) the chronological factor in understanding the middle and upper paleolithic of eurasia. current anthropology, 58(s17), s480s490. doi: 10.1086/694173 faith j.t., du a. (2018) the measurement of taxonomic evenness in zooarchaeology. archaeological and anthropological sciences, 10(6), 1419-1428. fernández-jalvo y., andrews p. (2018) atlas of taphonomic identifications: 1001+ images of fossil and recent mammal bone modification. springer. fiore i., gala m., tagliacozzo a. (2004) ecology and subsistence strategies in the eastern italian alps during the middle palaeolithic. international journal of osteoarchaeology, 14(3-4), 273-286. doi: 10.1002/oa.761 fiore i., gala m., romandini m., cocca e., tagliacozzo a., peresani m. (2016) from feathers to food: reconstructing the complete exploitation of avifaunal resources by neanderthals at fumane cave, unit a9. quaternary international, 421(june), 134153. doi: 10.1016/j.quaint.2015.11.142 fisher j.w. (1995) bone surface modifications in zooarchaeology. journal of archaeological method and theory, 2(1), 7-68. doi: 10.1007/bf02228434 fleitmann d., cheng h., badertscher s., edwards r.l., mudelsee m., göktürk o.m., fankhauser a., pickering r., raible c.c., matter a., kramers j., tüysüz o. (2009) timing and climatic impact of greenland interstadials recorded in stalagmites from northern turkey. geophysical research letters, 36(19), l19707. doi: 10.1029/2009gl040050 fletcher w.j., sánchez goñi m.f., allen j.r.m., cheddadi r., combourieu-nebout n., huntley b., lawson i., londeix l., magri d., margari v., müller u.c., naughton f., novenko e., roucoux k., tzedakis p.c. (2010) millennial-scale variability during the last glacial in vegetation records from europe. quaternary science reviews, 29(21-22), 2839-2864. doi: 10.1016/j.quascirev.2009.11.015 frouin m., douka k., dave a.k., schwenninger j.-l., mercier n., murray a.s., santaniello f., boschian g., grimaldi s., higham t. (2022) a refined chronology for the middle and early upper paleolithic sequence of riparo mochi (liguria, italy). journal of human evolution, 169, 103211. doi: 10.1016/j.jhevol.2022.103211 galán a.b., rodríguez m., de juana s., domínguezrodrigo m. (2009) a new experimental study on percussion marks and notches and their bearing on the interpretation of hammerstone-broken faunal assemblages. journal of archaeological science, 36(3), 776-784. geiger m., gendron k., willmitzer f., sánchez-villagra m.r. (2016) unaltered sequence of dental, skeletal, and sexual maturity in domestic dogs compared to the wolf. zoological letters, 2(1), 16. doi: 10.1186/s40851-016-0055-2 gipson p.s., ballard w.b., nowak r.m., mech l.d. (2000) accuracy and precision of estimating age of gray wolves by tooth wear. the journal of wildlife management, 64(3), 752. doi: 10.2307/3802745 grayson d.k. (1984) quantitative zooarchaeology academic press. inc., new york. greenbaum g., friesem d.e., hovers e., feldman m.w., kolodny o. (2019) was inter-population connectivity of neanderthals and modern humans the driver of the upper paleolithic transition rather than its product?. quaternary science reviews, 217, 316-329. doi: 10.1016/j.quascirev.2018.12.011 grimaldi s., porraz g., santaniello f. (2014) raw material procurement and land use in the northern mediterranean arc: insight from the first protoaurignacian of riparo mochi (balzi rossi, italy). quartär internationales jahrbuch zur erforschung des eiszeitalters und der steinzeit, 113-127 seiten. doi: 10.7485/qu61_06 grimaldi s., santaniello f. (2014) new insights into final mousterian lithic production in western italy. quaternary international, 350, 116-129. doi: 10.1016/j.quaint.2014.03.057 grimaldi s., santaniello f., starnini e. (2017) -. le riparo mochi (balzi rossi, ventimiglia, italie) : les nouvelles fouilles. bulletin de la société préhistorique française, 114(1), 169-172. jstor.org/stable/44870313 habermehl k.h. (1961) die altersbestimmung bei haustieren. pelztieren und beim jagdbaren wild paul parey. habermehl k.h. (1992) the estimation of the age of the female ibex (capra ibex ibex l.) by skeletal development. anatomia, histologia, embryologia, 21(3), 193-198. heinrich h. (1988) origin and consequences of cyclic ice rafting in the northeast atlantic ocean during the past 130,000 years. quaternary research, 29 (2), 142-152. doi: 10.1016/0033-5894(88)90057-9 higham t., brock f., peresani m., broglio a., wood r., douka k. (2009) problems with radiocarbon dating the middle to upper palaeolithic transition in italy. quaternary science reviews, 28(13-14), 1257-1267. doi: 10.1016/j.quascirev.2008.12.018 higham t., compton t., stringer c., jacobi r., shapiro b., trinkaus e., chandler b., gröning f., collins c., hillson s., o’higgins p., fitzgerald c., fagan m. (2011) the earliest evidence for anatomically modern humans in northwestern europe. nature, 479(7374), 521-524. doi: 10.1038/nature10484 higham t., douka k., wood r., ramsey c.b., brock f., basell l., camps m., arrizabalaga a., baena j., barroso-ruíz c., bergman c., boitard c., boscato p., caparrós m., conard n.j., draily c., froment 152 perez a. et al. a., galván b., gambassini p., … jacobi r. (2014) the timing and spatiotemporal patterning of neanderthal disappearance. nature, 512(7514), 306309. doi: 10.1038/nature13621 hoffecker j.f. (2009) the spread of modern humans in europe. proceedings of the national academy of sciences, 106(38), 16040-16045. doi: 10.1073/pnas.0903446106 holt b., negrino f., riel-salvatore j., formicola v., arellano a., arobba d., boschian g., churchill s. e., cristiani e., di canzio e., vicino g. (2019) the middle-upper paleolithic transition in northwest italy: new evidence from riparo bombrini (balzi rossi, liguria, italy). quaternary international, 508,142-152. doi: 10.1016/j.quaint.2018.11.032 hublin j.j. (2015) the modern human colonization of western eurasia: when and where?. quaternary science reviews, 118, 194-210. doi: 10.1016/j.quascirev.2014.08.011 isetti g. (1961) una stazione paleolitica nel centro di sanremo. rivista di studi liguri, 27, 5-44. jones e.l. (2022) what is a refugium? questions for the middle-upper palaeolithic transition in peninsular southern europe. journal of quaternary science, 37(2), 136-141. doi: 10.1002/jqs.3274 klein r.g., cruz-uribe k. (1984) the analysis of animal bones from archaeological sites. university of chicago press. kuhn s.l., stiner m.c. (1998) the earliest aurignacian of riparo mochi (liguria, italy). curr. anthropol., 39, 175-189. doi: 10.1086/204694 laplace g. (1977) il riparo mochi ai balzi rossi di grimaldi (fouilles 1938-1949). les industries leptolithiques 32(1-2), 3-131. lyman r.l. (1994) vertebrate taphonomy. cambridge university press. marciani g., ronchitelli a., arrighi s., badino f., bortolini e., boscato p., boschin f., crezzini j., delpiano d., falcucci a., figus c., lugli f., oxilia g., romandini m., riel-salvatore j., negrino f., peresani m., spinapolice e.e., moroni a., benazzi s. (2020) lithic techno-complexes in italy from 50 to 39 thousand years bp: an overview of lithic technological changes across the middle-upper palaeolithic boundary. quaternary international, 551, 123-149. doi: 10.1016/j.quaint.2019.11.005 mariezkurrena k., altuna j. (1983) contribución al conocimiento del desarrollo de la dentición y el esqueleto postcraneal de cervus elaphus. munibe, 35(3/4), 149-202. mauget r. (1981) behavioural and reproductive strategies in wild forms of sus scrofa (european wild boar and feral pigs). in sybesma w. (ed). the welfare of pigs. the hague, martinus nijhoff. 11, 3 -13. mcdonald j.n. (1981) north american bison: their classification and evolution. university of california press. mellars p. (2006) archeology and the dispersal of modern humans in europe: deconstructing the “aurignacian”. evolutionary anthropology: issues, news, and reviews, 15(5), 167-182. doi: 10.1002/evan.20103 naughton f., sánchez goñi m.f., kageyama m., bard e., duprat j., cortijo e., desprat s., malaizé b., joly c., rostek f., turon j.-l. (2009) wet to dry climatic trend in north-western iberia within heinrich events. earth and planetary science letters, 284(3-4), 329-342. doi: 10.1016/j.epsl.2009.05.001 negrino f., starnini e. (2003) patterns of lithic raw material exploitation in liguria from the palaeolithic to the copper age. 5, 235-243. negrino f., starnini e., bertola s. (2016) red radiolarite availability in western liguriae? a challenging enigma from ortovero (savona, liguria, northern italy). ressources lithiques, productions et transferts entre alpes et méediterranée, 45-53. negrino f., tozzi c. (2008) il paleolitico in liguria. bull. mus. anthrop. préhist. monaco suppl., 1, 2128. noddle b. (1974) ages of epiphyseal closure in feral and domestic goats and ages of dental eruption. journal of archaeological science, 1(2), 195-204. doi: 10.1016/0305-4403(74)90042-9 pales l., lambert c. (1971) atlas ostéologique: pour servir à l’identification des mammifères du quaternaire. les membres herbivores. centre national de la recherche scientifique. pales l., lambert c. (1981) atlas ostéologique pour servir à l’identification des mammifères du quaternaire: 1, tête-rachis, ceintures scapulaire et pelvienne. éd. du cnrs. palma di cesnola a. (1993) il paleolitico superiore in italia: introduzione allo studio. garlatti e razzai. pelletier m., desclaux e., brugal j.-p., texier p.-j. (2019) the exploitation of rabbits for food and pelts by last interglacial neandertals. quaternary science reviews, 224, 105972. doi: 10.1016/j.quascirev.2019.105972 peresani m., fiore i., gala m., romandini m., tagliacozzo a. (2011) late neandertals and the intentional removal of feathers as evidenced from bird bone taphonomy at fumane cave 44 ky b.p., italy. proceedings of the national academy of sciences of the united states of america, 108(10), 3888-3893. doi: 10.1073/pnas.1016212108 perez a., santaniello f., grimaldi s., gialanella s. (2020) distinguishing colour alteration processes occurred in late pleistocene animal remains. 6. pickering t.r., egeland c.p. (2006) experimental patterns of hammerstone percussion damage on bones: implications for inferences of carcass processing by humans. journal of archaeological science, 33(4), 459-469. porraz g., simon p., pasquini a. (2010) identité technique et comportements économiques des groupes proto-aurignaciens à la grotte de l’observatoire (principauté de monaco). gallia préhistoire, 52(1), 33-59. 153 the faunal assemblage from the riparo mochi site. doi: 10.3406/galip.2010.2470 potts r., shipman p. (1981) cutmarks made by stone tools on bones from olduvai gorge, tanzania. nature, 291, 577-580. doi: 10.1038/291577a0 psathi e. (2003) les sites moustériens de la caverna delle fate et de l’arma delle manie (ligurie, italie): étude paléontologique et archéozoologique des faunes des grands mammifères. paris, muséum national d’histoire naturelle. rasmussen s.o., bigler m., blockley s. p., blunier t., buchardt s.l., clausen h.b., cvijanovic i., dahl-jensen d., johnsen s.j., fischer h., gkinis v., guillevic m., hoek w.z., lowe j.j., pedro j.b., popp t., seierstad i.k., steffensen j.p., svensson a.m., vallelonga p., vinther b.m., walker m.j.c. , wheatley j.j., winstrup m. (2014) a stratigraphic framework for abrupt climatic changes during the last glacial period based on three synchronized greenland ice-core records: refining and extending the intimate event stratigraphy. quaternary science reviews, 106, 14-28. doi: 10.1016/j.quascirev.2014.09.007 renault-miskovsky j. (1972) contribution à la paléoclimatologie du midi méditerranéen pendant la dernière glaciacion et le post-glaciaire, d’après l’étude palynologique du remplissage des grottes et abris sous roche. université de paris vi. rey-rodríguez i., lópez-garcía j.-m., bennàsar m., bañuls-cardona s., blain h.-a., blanco-lapaz á., rodríguez-álvarez x.-p., de lombera-hermida a., díaz-rodríguez m., ameijenda-iglesias a., agustí j., fábregas-valcarce r. (2016) last neanderthals and first anatomically modern humans in the nw iberian peninsula: climatic and environmental conditions inferred from the cova eirós smallvertebrate assemblage during mis 3. quaternary science reviews, 151, 185-197. doi: 10.1016/j.quascirev.2016.08.030 romandini m., peresani m., laroulandie v., metz l., pastoors a., vaquero m., slimak l. (2014) convergent evidence of eagle talons used by late neanderthals in europe: a further assessment on symbolism. plos one, 9(7). doi: 10.1371/journal.pone.0101278 romandini m., thun hohenstein u., fiore i., tagliacozzo a., perez a., lubrano v., terlato g., peresani m. (2018) late neandertals and the exploitation of small mammals in northern italy: fortuity, necessity or hunting variability?. quaternaire, vol. 29/1, 61-67. doi: 10.4000/quaternaire.8626 santaniello f., grimaldi s. (2019) le gravettien entre l’italie et la france. nouvelles données sur l’industrie lithique de l’abri mochi (balzi rossi, italie). bulletin de la société préhistorique française, 116, 2, 255-282. doi: 10.3406/bspf.2019.15000 schmid e. (1972) atlas of animal bones: for prehistorians, archaeologists and quaternary geologists. knochenatlas. fur prahistoriker, archaologen und quartargiologen. drawings by otto garraux. elsevier, amsterdam. shipman p. (1981) life history of a fossil: an introduction to taphonomy and paleoecology. harvard university press, cambridge, mass. shipman p., rose j.j. (1984) cutmark mimics on modern and fossil bovid bones. current anthropology, 25(1), 116-117. silver i.a. (1969) the ageing of domestic animals. science in archaeology, 283-302. simpson e.h. (1949) measurement of diversity. nature, 163(4148), 688-688. doi: 10.1038/163688a0 slimak l., zanolli c., higham t., frouin m., schwenninger j.-l., arnold l.j., demuro m., douka k., mercier n., guérin g., valladas h., yvorra p., giraud y., seguin-orlando a., orlando l., lewis, j.e., muth x., camus h., vandevelde s., … metz, l. (2022) modern human incursion into neanderthal territories 54,000 years ago at mandrin, france. science advances, 8, 17. doi: 10.1126/sciadv.abj9496 sommer r.s., zachos f.e., street m., jöris o., skog a., benecke n. (2008) late quaternary distribution dynamics and phylogeography of the red deer (cervus elaphus) in europe. quaternary science reviews, 27(7-8), 714-733. doi: 10.1016/j.quascirev.2007.11.016 stiner m.c. (1998) mortality analysis of pleistocene bears and its paleoanthropological relevance. journal of human evolution, 34(3), 303-326. doi: 10.1006/jhev.1997.0198 stiner m.c., kuhn s.l., weiner s., bar-yosef o. (1995) differential burning, recrystallization, and fragmentation of archaeological bone. journal of archaeological science. doi: 10.1006/jasc.1995.0024 straus l.g. (1981) on the habitat and diet of cervus elaphus. munibe, 33(3-4), 175-182. tagliacozzo a., zeppieri f., fiore i., spinapolice e., del lucchese a. (2012) archaeozoological evidence of subsistence strategies during the gravettian at riparo mochi (balzi rossi, ventimiglia, imperiaitaly). quaternary international, 252(november 2018), 142-154. doi: 10.1016/j.quaint.2011.03.059 tejero j.m., grimaldi s. (2015) assessing bone and antler exploitation at riparo mochi (balzi rossi, italy): implications for the characterization of the aurignacian in south-western europe. journal of archaeological science, 61, 59-77. doi: 10.1016/j.jas.2015.05.003 timmermann a. (2020) quantifying the potential causes of neanderthal extinction: abrupt climate change versus competition and interbreeding. quaternary science reviews, 238, 106331. doi: 10.1016/j.quascirev.2020.106331 tomasso a. (2014) pérennité et évolution des territoires d’approvisionnement au paléolithique supérieur: l’exemple de l’épigravettien de la grotte des enfants (ventimiglia, italie). in modes de contacts et de déplacements au paléolithique eurasiatique, université de liège/mnha-cnra luxembourg, liège, 513-532. tomé c., vigne j.-d. (2003) roe deer (capreolus cap 154 perez a. et al. reolus) age at death estimates: new methods and modern reference data for tooth eruption and wear, and for epiphyseal fusion. archaeofauna, international journal of archaeozoology, 12, 157173. valensi p. (2000) the archaeozoology of lazaret cave (nice, france). international journal of osteoarchaeology, 10(5), 357-367. valensi p., psathi e. (2004) faunal exploitation during the middle palaeolithic in south-eastern france and north-western italy. international journal of osteoarchaeology, 14(3-4), 256-272. doi: 10.1002/oa.760 vettese d. (2014) le traitement des carcasses d’ongulés chez les néanderthaliens de l’abri du maras (ardèche, mis4) / individualisme ou poids des traditions?. master dissertation. muséum national d’histoire naturelle, paris. vettese d., daujeard c., blasco r., borel a., cáceres i., moncel m.-h. (2017) neandertal long bone breakage process: standardized or random patterns? the example of abri du maras (southeastern france, mis 3). journal of archaeological science, reports, 13, 151-163. vettese d., blasco r., cáceres i., gaudzinskiwindheuser s., moncel m.-h., thun hohenstein u., daujeard c. (2020) towards an understanding of hominin marrow extraction strategies: a proposal for a percussion mark terminology. archaeological and anthropological sciences, 12(2), 48. doi: 10.1007/s12520-019-00972-8 villa p., roebroeks w. (2014) neandertal demise: an archaeological analysis of the modern human superiority complex. plos one, 9(4), e96424. doi: 10.1371/journal.pone.0096424 weinstock j. (2009) epiphyseal fusion in brown bears: a population study of grizzlies (ursus arctos horribilis) from montana and wyoming. international journal of osteoarchaeology, 19(3), 416-423. doi: 10.1002/oa.980 zeppieri f. (2009) i macromammiferi del livello gravettiano “d” di riparo mochi (balzi rossi, ventimiglia), scavi blanc e cardini 1938e1959. considerazioni archeozoologiche e tafonomiche. tesi di laurea specialistica, università degli studi di ferrara 2009 (relatori: u. thun hohenstein e a. tagliacozzo). 155 ms. received: october 04, 2022 revised: december 12, 2022 accepted: december 15, 2022 available online: december 29, 2022 the faunal assemblage from the riparo mochi site. 156 imp.parolo& studio integrato fito-geomorfologico di un sistema di rocce montonate serpentinitiche (campagneda, alpi retiche, sondrio) gilberto parolo1, alberto carton2 & augusto pirola1 1dipartimento di ecologia del territorio e degli ambienti terrestri. università degli studi di pavia; e-mail: parolo@et.unipv.it 2dipartimento di scienze della terra. università degli studi di pavia. e-mail: carton@unipv.it riassunto: g. parolo et al., studio integrato fito-geomorfologico di un sistema di rocce montonate serpentinitiche (campagneda, alpi retiche, sondrio). (it issn 0394-3356, 2005). scopo di questo lavoro è l’identificazione di relazioni ripetibili tra le geoforme e le comunità vegetali, al fine di sviluppare indicatori vegetazionali di forme del paesaggio e dei processi geomorfologici che le interessano. l’area di studio è localizzata nella fascia boreale superiore in val malenco (provincia di sondrio, alpi retiche). il gruppo di rocce montonate è scolpito su un substrato serpentinitico del mesozoico ed è marginato da una serie di depositi glaciali, espressione di tre piccoli apparati morenici frontali riconducibili alle fasi stadiali tardiglaciali. diciannove rilievi fitosociologici, analizzati con il programma syn-tax 2000 sono risultati ripartiti in 5 gruppi distinti. indici di ricchezza e di diversità specifica (shannon-weaver: h = -σi pi ln pi), di dominanza (simpson: λ = σi pi 2) e di equitabilità (pielou: j = h / hmax, dove hmax = ln n° individui) sono stati calcolati per ciascuno dei popolamenti rilevati con l’intento di dedurre informazioni sulla loro stabilità ecologica ed organizzazione strutturale. la datazione dei depositi glaciali posti a contatto e a margine delle rocce montonate, effettuata mediante il calcolo dell’innalzamento del limite delle nevi, ha permesso di attribuire, al substrato su cui sono scolpite le rocce montonate, un’età superiore ai 13.000 anni b.p. la distribuzione e la variabilità delle fitocenosi sono collegate alla esistenza di condizioni ambientali diversificate, correlate con l’andamento morfologico del substrato, che influenza la disponibilità idrica dei suoli, la distribuzione della copertura nevosa e gli effetti legati al vento. le comunità vegetali sono dinamicamente stabilizzate dalle condizioni climatiche ed edafiche estremamente selettive. tuttavia processi di ringiovanimento edafico innescano regressioni dinamiche nelle comunità vegetali, verificatisi probabilmente in occasione di manifestazioni meteorologiche intense, oppure in relazione alle profonde sollecitazioni meccaniche generate dai processi crio e/o termoclastici a cui sono sottoposti i substrati. si può comunque ipotizzare una potenzialità della vegetazione diretta, a lungo termine, verso la formazione di una brughiera extrasilvatica a rododendro (rhododendretum ferruginei). infine, la distribuzione a mosaico delle comunità vegetali, relazionabile alla presenza di microhabitat ripetitivi e collegati potenzialmente da relazioni seriali o catenali, evidenzia la possibilità di considerare il sistema di rocce montonate in oggetto un geosigmeto. abstract: g. parolo et al., phyto-geomorphological integrated study of a serpentinitic roches moutonnées system (campagneda, rhaetian alps, sondrio, italy). (it issn 0394-3356, 2005). the aim of this work is to identify repeatable linkages between landforms and diagnostic features of the vegetation, as a preliminary step in the development of phytoindicators for geomorphological forms and processes. the study area is located in the upper boreal belt of the malenco valley (sondrio province, rhaetian alps). the roches moutonnées consist of mesozoic serpentinitic substratum and are surrounded by a sequence of glacial deposits. this sequence represents the expression of three little terminal morainic ridges, belonging to the late glacial age. syn-tax 2000 was used to analyse 19 phytosociological relevés; a cluster analysis (group average, similarity ratio) and a metrical ordination (pcoa, chord distance), applied to all the relevés, pointed out the presence of 5 distinct groups. richness and diversity indexes (shannon-weaver index: h = -σi pi ln pi), dominance (simpson index: λ = σi pi 2) and evenness (pielou index: j = h / hmax, where hmax = ln n° individuals) have been calculated for all the plant communities, to look into their ecological stability and structural composition. we estimated the age of the glacial deposits, that surround the roches moutonnées, by using the raising of the equilibrium line altitude. this allowed to attribute more than 13.000 years b.p. to the substratum of the roches moutonnées. the distribution and variability of the phytocoenoses are linked to the existence of different environmental conditions, depending on geomorphological processes and forms of relief, that influence the water availability in the substratum, the snow cover and the wind effects. the extremely severe climatic and edaphic conditions stop the dynamic of the both plant communities of summits and interposed depressions. nevertheless processes of edaphic rejuvenation promote regressive events in the vegetation cover; this is probably related to intense meteorological processes or depends on deep mechanical stresses caused by cryoand/or termoclastic processes, that affect the substrata. we can, however, suppose that the potential expression of the vegetation could lead, in the long term, to acidocline alpenrose heaths (rhododendretum ferruginei). because of the mosaic distribution of plant communities, related to the repetitive presence of microhabitat and potentially linked by catenal and seral relationships, the roches moutonnées system can be considered a geosigmetum. parole chiave: studio fito-geomorfologico; vegetazione alpina; rocce montonate; depositi tardiglaciali; alpi retiche; fascia boreale superiore; substrati serpentinitici. keywords: phyto-geomorphological study; alpine plant communities; roches moutonnées; late glacial deposits; rhaetian alps; upper boreal belt; serpentinitic substrata. il quaternario italian journal of quaternary sciences 18(2), 2005 69-86 70 g. parolo, a. carton & a. pirola 1. introduzione la copertura vegetale e la forma del rilievo terrestre presentano spesso importanti e molteplici interazioni, specialmente in ambienti di alta montagna, ove tali rapporti risultano più evidenti (braun-blanquet, 1972; panizza, 1980; ozenda, 1985; ellenberg, 1988; körner, 1999). i fattori orografici, derivanti dall’andamento del rilievo, hanno un’influenza notevole sugli organismi vegetali, soprattutto perché sono in grado di influenzare l’espressione di altri fattori, quali quelli climatici. a sua volta la copertura vegetale influisce sia direttamente che indirettamente sulla morfogenesi, limitando ad esempio i processi erosivi dovuti all’azione dell’acqua e del vento, e figurando, specie se ben sviluppata, come causa ed indizio di stabilità morfologica. l’interazione vegetazione-geoforma è un processo analizzabile a differenti livelli di percezione fitoecologica, contraddistinti da gradi di complessità crescente: sinusie, fitocenosi e individui di geosigmassociazioni (gillet, 1985), possono essere utilizzati a varia scala per verificare il grado di fedeltà e la ripetitività dei rapporti con forme del paesaggio di diverso ordine di grandezza. negli ultimi decenni, accanto a studi volti ad indagare gli effetti dei processi geomorfologici sulla copertura vegetale in ambienti periglaciali, dal punto di vista ecologico e dinamico (giacomini & pirola, 1957; pirola, 1959; 1962; carbinier, 1966; klug-pümpel, 1982; richard, 1987; pirola & credaro, 1994; pirola et al., 1998; rossi et al., 1998; becker & dierschke, 2005), si sono sviluppati metodi di indagine, recentemente anche in ambito gis, che ricercano le relazioni spaziali di interdipendenza tra le forme del paesaggio e i syntaxa vegetazionali, con l’intento di individuare corrispondenze statisticamente ripetibili; le comunità vegetali diventano così indicatrici di determinate geoforme e/o di processi geomorfologici (delpech, 1985; gerdol et al., 1985; gerdol & smiraglia 1990; tomaselli & agostini, 1990; hoersch et al., 2002; kozlowska & raczkowska, 2002; bertin, 2003; cannone & gerdol, 2003; parolo, 2003; caccianiga & andreis, 2004); la loro aggregazione in unità superiori secondo relazioni di tipo dinamico o catenale, qualora l’unità si presenti fortemente eterogenea, rappresenta il primo livello di indagine nella descrizione del paesaggio vegetale (gehu & rivaz martinez, 1981; gehu, 1988; theurillat, 1992a), definibile soltanto attraverso l’identificazione delle unità elementari che lo costituiscono (ecotopi), confermate dalla ripetitività delle corrispondenze tra ambiente fisico e fitocenosi (pedrotti et al., 1997). il presente lavoro si propone di evidenziare relazioni ecologiche ripetibili tra geoforme e comunità vegetali in un sistema di rocce montonate serpentinitiche in ambiente alpino extrasilvatico, con lo scopo di individuare aree fito-geomorfologiche unitarie del paesaggio e di sviluppare indicatori vegetazionali di forme del paesaggio e dei processi geomorfologici che le interessano. le rocce montonate si possono annoverare tra le principali forme di erosione glaciale. si tratta di gobbe rocciose spesso associate in gruppi, frequentemente sagomate secondo la direzione di movimento del ghiacciaio, levigate sopra e sul lato rivolto contro il flusso glaciale, scabre sul lato sotto corrente. sono ben evidenti nelle attuali aree proglaciali ed osservabili in ambienti oggi prevalentemente sottoposti a processi crionivali o più generalmente ove vi sia stato il passaggio di un ghiacciaio. l’esarazione forma in genere, tra un dosso roccioso e l’altro, depressioni da sovraescavazione disposte sia in senso longitudinale sia in senso trasversale rispetto alla direzione del flusso glaciale. l’entità dell’erosione è in diretta relazione con le caratteristiche meccaniche della roccia e con la quantità di detrito trasportato dal ghiacciaio lungo l’interfaccia roccia/ghiaccio. le depressioni tra una roccia montonata e l’altra “catturano” spesso detrito fine, generato dai processi di degradazione, che funge da substrato per la vegetazione. nel sistema di rocce montonate studiato, situato sulle alpi retiche, si osserva che l’alternanza di dossi e di depressioni induce la formazione di un mosaico di condizioni micro-ambientali, variabili in modo repentino anche su spazi ridotti (fig. 1). le depressioni, scavate nella roccia, sono di norma caratterizzate da una saturazione idrica più o meno spinta dovuta alla permanenza prolungata del manto nevoso ed al ristagno di acqua, favorito dalla frazione pelitica presente, convogliata nelle depressioni dal ruscellamento nivale e dalle piogge. queste porzioni di terreno, a maggiore umidità, nelle stagioni intermedie gelano fino ad alcuni decimetri di profondità, rendendo superficialmente impermeabile il suolo. sui dossi, al contrario, i periodi prolungati di siccità e le basse temperature invernali, il cui effetto sulla componente biotica è aggravato dalla scarsa copertura nevosa, favoriscono lo sviluppo di comunità vegetali a struttura generalmente aperta, con adattamenti xeromorfi. 2. area di studio l’area di studio (fig. 2) è ubicata in val malenco nel piano di campagneda (provincia di sondrio) tra i 2200 e i 2310 m e comprende un sistema di rocce montonate modellate dal ghiaccio durante i l tardiglaciale. i dossi montonati e le contigue depressioni da sovraescavazione si alternano con passaggi bruschi e repentini da una forma all’altra oppure possono essere collegati da superfici, più o meno estese, a dolce inclinazione (10°÷20°). esse sono scolpite nella formazione delle “serpentine della val malenco” fig. 1 le rocce montonate serpentinitiche oggetto della ricerca. the object of this research: the serpentinitic roches moutonnées. (aa.vv., 1970), rocce mesozoiche metamorfiche (serpentini e serpentinoscisti) con chimismo ultramafico. altre rocce montonate risultano modellate su ridotti affioramenti di rocce metamorfiche silicee, appartenenti alla formazione dei “micascisti del m.te acquanera”; su queste ultime non sono stati effettuati rilevamenti fitosociologici. il clima è di tipo temperato continentale; secondo la recente classificazione fitoclimatica di blasi (1996) può essere ascritto al termotipo alpino e all’ombrotipo ultraiperumido. le condizioni climatiche rigide dell’area, caratterizzate da basse temperature medie annuali, da accentuate escursioni termiche stagionali e giornaliere e da abbondanti precipitazioni nevose, sottopongono le rocce emergenti a processi degradativi provocati dall’alternarsi di fasi di gelo e di disgelo (gelifrazione), particolarmente efficaci in quanto favoriti dall’elevata scistosità, tipica delle rocce serpentinitiche. 2.1 studi geomorfologici precedenti non esistono approfonditi studi di geomorfologia che riguardano l’area in esame; la maggior parte dei lavori prende in considerazione gli aspetti geologici, soprattutto a scala regionale (benning & sidler, 1992). frammentarie notizie si possono ricavare da studi più generali sul glacialismo quaternario della val malenco e delle alpi insubriche valtellinesi. il primo lavoro che si può in un certo qual senso considerare di carattere geomorfologico risale al 1930 (nangeroni, 1930). nell’opera l’autore, sulla base delle morene “stadiarie”, ricostruisce i ghiacciai della val malenco, ne traccia i limiti e fornisce ai vari depositi una attribuzione cronologica. successivamente godenzi (1957) pubblica la sua tesi di laurea che riguarda la morfologia glaciale e la geomorfogenesi della valle di poschiavo. nel lavoro vengono fatti alcuni r iferimenti al la zona di campagneda, senza però entrare nel dettaglio della morfologia. alcune informazioni sui depositi quaternari 71studio integrato fito-geomorfologico ... si possono ricavare invece dalla geologiche karte der bernina gruppe alla scala 1:50.000 (staub, 1946); in essa vengono cartografati con estremo dettaglio i depositi glaciali e gli argini morenici presenti nell’alpe di campagneda e nell’alpe di prabello. lo staub differenzia in questa zona tre unità glaciali. in un successivo lavoro venzo (venzo, 1971), pur tracciando un quadro completo ed estremamente articolato degli stadi tardowürmiani e post würmiani delle alpi insubriche valtellinesi, raramente fa specifico riferimento all’area oggetto del presente studio. 2.2 inquadramento vegetazionale la vegetazione dell'area di studio è compresa nella regione forestale endalpica (del favero, 2002), al di sopra dell’attuale limite superiore del bosco chiuso, collocabile mediamente attorno ai 2200 m. le fasce vegetazionali riconoscibili nel piano di campagneda sono la boreale superiore, caratterizzata da alberi isolati e da arbusteti nani o contorti fino a 2400 m, la fascia alpica in cui dominano le praterie naturali chiuse con presenze discontinue di tundra alpina, e infine la fascia nivale definita in base alla fisionomia discontinua della vegetazione erbacea (zolle aperte) progressivamente sostituita da comunità prevalentemente con strutture proprie degli stadi pionieri, su pietraie e rocce (tab. 1). in questi ambienti, durante le fasi iniziali, si riscontrano comunità vegetali caratterizzate dalla compresenza di specie acidofile e basifile, tipiche dei litotipi di natura serpentinitica. al di sotto dei 2000 m si esprime la pecceta subalpina (piceeion abietis), che viene sostituita più in altitudine da boschi aperti e luminosi di larice con sottobosco di ericacee e da arbusteti extrasilvatici (rhododendretum ferruginei), localmente interrotti da praterie secondarie pascolate (sieversio-nardetum strictae). tutta la fascia boreale superiore può essere considerata un ampio ecotono determinato dalla variazione altitudinale delle condizioni ambientali progressivamente più rigide che riducono o escludono i fattori favorevoli alle forme arboree e arbustive (“zona di contesa”). la vegetazione potenziale è la brughiera extrasilvatica di arbusti nani a rododendro e mirti l lo (rhododendretum ferruginei), riscontrabile sulle rocce montonate localizzate in posizione marginale all’area di studio. la pastorizia, ancora attiva, ha modificato questo paesaggio con il decespugliamento e il pascolo, lasciando però frammenti di vegetazione naturale molto significativi per il riconoscimento dei limiti altitudinali che separano le fasce di vegetazione. nella fascia boreale superiore si trovano lembi di vegetazione idroigrofila, ascrivibile alle torbiere basse, situate in depressioni alimentate da acque superficiali o da sorgenti. inoltre in corrispondenza di limitate emergenze di calcari metamorfosati, vi sono frammenti di praterie basifile. la transizione alla fascia alpica è poco evidente per le modificazioni delle praterie alpine in pascoli dominati da nardus stricta ma, dove il disturbo è solo saltuario o assente, si trovano le praterie naturali tra cui quella considerata il climax alpino, il caricetum curvulae. la fascia nivale inizia all’altitudine di circa 2900 m, quota da considerare teorica per il fatto che la discesa a quote inferiori di pietraie a lungo innevamento determina frequenti enclavi extrazonali della vegetazione periglaciale (androsacetalia alpinae). fig. 2 l’area di studio si trova nel piano di campagneda (val malenco, sondrio), tra i 2200 e i 2300 m di altitudine. the study area is located in the campagneda plain (malenco valley, sondrio), between 2200 and 2300 metres high. 72 3. metodi la vegetazione è stata studiata secondo l’approccio sociologico della scuola di zürich-montepellier (braun-blanquet, 1964). diciannove rilievi fitosociologici, eseguiti nel periodo 2002-2003, sono stati sottoposti a cluster analysis utilizzando il programma syn-tax 2000 (podani, 2001); la classificazione gerarchica è stata ottenuta applicando il criterio agglomerativo legame medio (group average) e la similarity ratio come indice di somiglianza. l’ordinamento metrico dei rilievi è stato calcolato attraverso l’analisi delle coordinate principali (pcoa) e la distanza della corda (chord distance). le misure di diversità (numero di specie, diversità specifica di shannon & weaver, 1949: h = -σi pi ln pi), dominanza (simpson, 1949: λ = σi pi 2) e di equitabilità (pielou, 1969: j = h / hmax con hmax = ln n° individui) sono state calcolate previa conversione degli indici di ricoprimento nei rispettivi valori percentuali centrali (braun-blanquet, 1964). i valori ricavati per ognuno dei quattro parametri sono stati sostituiti nell’ordinamento metrico ai numeri dei rilievi e riprodotti graficamente con simboli di grandezza proporzionale ai valori numerici ottenuti. per la nomenclatura floristica e le forme biologiche si è fatto riferimento ad aeschimann et al. (2004). per la nomenclatura fitosociologica e l’inquadramento sintassonomico ci si è attenuti a grabherr & mucina (1993) per la classe asplenietea trichomanis, a poldini & oriolo (1997) per la classe caricetea curvulae, ad eggensberger (1994) per la classe vaccinio-piceetea, a gerdol & tomaselli (1997) per la classe scheuchzeriocaricetea nigrae e ad oriolo (2001) per l’inquadramento dell’alleanza oxytropido-elynion nella classe elynoseslerietea. tuttavia il numero esiguo di rilievi e le condizioni spesso estreme cui sono soggetti i popolamenti si traducono talvolta in una loro difficoltosa attribuzione ai syntaxa noti in letteratura, di cui spesso rappresentano aspetti frammentati, floristicamente impoveriti o varianti dovute all’apporto di basi da parte delle rocce serpentinitiche. per datare i depositi glaciali che marginano le rocce montonate e per inquadrare cronologicamente il substrato su cui sono impostate, è stata ricostruita, sulla base delle geometrie assunte dagli argini morenici, la quota del limite delle nevi. tale parametro è stato calcolato con il sistema proposto da marinelli (1928) e non con il metodo aar (gross et al., 1977) per mancanza di significativi punti quotati di riferimento all’esterno delle aree glacializzate. per l’unità del cornetto è stato calcolato il limite delle nevi utilizzando anche la quota delle terminazioni, verso monte, degli argini laterali. il valore individuato è di 2680 m; ciò indica che in questa zona il metodo “marinelli”(cfr. tab. 2) sovrastima di 25 metri il reale limite delle nevi. come valore di riferimento per il calcolo della variazione dei limiti delle nevi si è tenuto conto del livello bzn (bezugsniveau) (kerschner, 1976). i valori ottenuti sono stati confrontati con quelli ricavati per le alpi svizzere (maisch, 1982). tab. 1 distribuzione altitudinale della vegetazione. altitudinal distribution of the plant communities. fasce tipi di vegetazione popolamenti discontinui di licheni e briofite nivale comunità discontinue delle rupi e delle pietraie (androsacion vandellii; androsacion alpinae) comunità delle vallette nivali (salicetea herbaceae) frammenti di praterie alpine (caricion curvulae) limite climatico delle nevi (2900 m) praterie alpine microterme ed eliofile (caricion curvulae; agrostion schraderanae; festucion variae) comunità discontinue delle rupi e delle pietraie (androsacion vandellii; androsacion alpinae) comunità delle vallette nivali (salicetea herbaceae) alpica praterie microterme pascolate (poion alpinae) cespuglietti nani a loiseleuria procumbens (loiseleurio-vaccinion) frammenti di torbiere acidofile (caricion nigrae) vegetazione fontinale (cardamino-montion) limite degli arbusti nani (2400 m) pascoli a nardo e a carex sempervirens (nardion strictae); brughiere extrasilvatiche (loiseleurio-vaccinion; rododendro-vaccinion; juniperion nanae) comunità discontinue delle rupi (androsacion vandellii) boreale superiore comunità discontinue delle pietraie e dei greti (androsacetalia alpinae; salicion incanae) (extrasilvatica) torbiere (scheuchzerio-caricetea nigrae) comunità nitrofile dei riposi (rumicion alpini) frammenti di megaforbieti (adenostylion) vegetazione fontinale (cardamino-montion) limite del bosco chiuso (2200 m) g. parolo, a. carton & a. pirola 73 4. risultati e discussione 4.1 le rocce montonate: età e contesto geomorfologico la carta geomorfologica di fig. 3 rappresenta il contesto geomorfologico in cui è inserito il gruppo di rocce montonate studiate; queste appartengono ad un ampio complesso di analoghe forme, ubicate sul versante ad occidente della linea di cresta che si sviluppa tra i l passo degli ometti (2758 m) e i l passo di campagneda (2601 m), passando per il pizzo scalino (3323 m) e per l’attuale esiguo ice divide che separa la vedretta di pizzo scalino dalla sua transfluenza verso nord-ovest, in direzione del piano di campagneda. il “campo” di rocce montonate (che nella sua totalità raggiunge più o meno la superficie di circa 2 km2) si sviluppa tra i 2000 ed i 2360 m di quota ed è marginato su tre lati da depositi glaciali, alcuni dei quali modellati in evidenti, ben conservati ed articolati argini morenici. al di sopra dei 2200-2250 m, le superfici rocciose montonate, affiorano per la quasi totalità. al di sotto di tale quota, pur essendo ancora evidenti i lineamenti delle rocce esarate dal ghiaccio, prendono il sopravvento morfologie di tipo più decisamente gravitativo, diffusamente ricoperte da vegetazione quasi continua. i contorni ed i profili delle rocce montonate si presentano assai spesso scabri e scheletrici, per la lunga esposizione agli agenti del modellamento che hanno agito su un substrato fissile, e sono ulteriormente marcati dall’approfondimento delle numerose fratture che le separano. l’erosione glaciale ha esaltato discontinuità del substrato diversamente orientate, scolpendo campi di rocce montonate con asse maggiore disposto lungo differenti direttrici. la frequente non coincidenza degli orientamenti della fratturazione con le probabili linee di flusso del ghiaccio (così come possono essere desunte dalla topografia e dalle rarissime tracce di esarazione lasciate sulle rocce) fanno si che spesso i dossi siano asimmetrici rispetto al loro asse maggiore, soprattutto nella parte scabra sotto corrente. i depositi glaciali posti a ridosso del campo di rocce montonate sono l’espressione di tre piccoli apparati morenici frontali di altrettanti ghiacciai di pendio, in origine saldati tra loro, che nelle ultime fasi stadiali tardiglaciali, si sono evoluti indipendentemente, in funzione delle diverse caratteristiche delle rispettive aree di alimentazione. la documentazione cartografica storica indica la presenza di ghiacciai sul versante est del piano di campagneda ancora nel 1833 (istituto geografico militare austriaco, 1833) e, con minor estensione, anche nel 1910 (carte topographique de la suisse, 1910). a fronte delle caratteristiche morfologiche, tessiturali, delle geometrie che gli argini morenici assumono e del grado di colonizzazione della vegetazione, sembra possibile effettuare una distinzione in cinque unità, strettamente locali, riferibili a diverse fasi e/o apparati glaciali. unità del cornetto (uco ). si tratta di depositi glaciali, appartenenti ad una lingua transfluente dalla vicina vedretta di pizzo scalino, modellati in un potente arco morenico, che tratteggia i limiti di una diverticolazione glaciale proveniente da una delle due insellature tra l’antecima di pizzo scalino (3107 m) ed il cornetto (2848 m). le geometrie dell’accumulo indicano che la lingua glaciale stazionava intono ai 2540 m. l’argine, nel suo lato esterno è rivestito da una prateria pingue microterma (poion alpinae) uniformemente distribuita, mentre al suo intertab. 2 tabella riassuntiva dei parametri fisici, geometrici e cronologici riferiti ai depositi glaciali, suddivisi in cinque unità. il parametro “quota limite delle nevi corretto” tiene in considerazione la differenza di quota che c’è tra il limite delle nevi calcolato con il metodo marinelli e quello più attendibile fornito, per l’unità del cornetto, dalla terminazione della morena laterale sinistra. vengono inoltre indicate le comunità vegetali presenti sulle cinque differenti unità di deposito glaciale. synoptic table showing the physical, geometrical and chronological parameters of the glacial deposits, subdivided into five units. the term “correct snow-line altitude” considers the difference of altitude between the snow-line, evaluated with marinelli’s method, and the limit obtained by measuring the upper altitude of the left lateral moraine, that is more reliable. the plant communities, that cover the five glacial units, are also indicated. unità 154 del cornetto x x 2540 2871 2705 2680 0 l.i.a. (1850 a.d.) 0,60 unità egesen di alpe prabello x x 2245 2938 2591 2566 114 bockten 10.000 ++ 1,3 unità del egesen piano di campagneda x x x 2200 2797 2499 2474 206 maximum 11.000 1,8 unità di campascio di caspoggio x x x 2060 2797 2428 2403 277 daun ii ? 13.000 + 2,3 unità di monte acquanera x 2040 2636 2338 2313 367 daun i ? 13.000 ++ 2,8 v e g e ta z io n e a nd ro sa ci on a lp in ae fe st uc et um s ca b ric ul m is c ar ic et um c ur vu la e p oi on a lp in ae r um ic et um a lp in i s ie ve rs io -n ar d et um s tr ic ta e r ho d od en d re tu m fe rr ug in ei q uo ta fr on te (m ) q uo ta m ed ia r ec in to (m ) q uo ta li m ite n ev i (m ) m ar in el li (1 92 8) q uo ta li m ite n ev i c or re tt o ∆ h lim ite n ev i r is p et to a b z n 1 85 0 e tà m a is c h , ( 19 82 ) e tà b .p . m a is c h , ( 19 82 ) ∆ t c ° ad o gg i (g ra d ie nt e 0, 6° c /1 00 m ) studio integrato fito-geomorfologico ... 74 fig. 3a) g. parolo, a. carton & a. pirola 75 fig. 3 carta geomorfologica del versante nord-occidentale tra pizzo scalino e monte acquanera. geomorphological map of the north-western slope between the scalino peak and the mount acquanera. fig. 3b) no la vegetazione, molto discontinua, è caratterizzata da consorzi discontinui microtermi tipici delle pietraie non stabilizzate (androsacion alpinae). la cartografia storica (istituto geografico militare austriaco, 1833) indica in questa posizione la presenza di una placca di ghiaccio ancora nel 1833. per questo motivo, per la freschezza delle forme, per la tipica morfologia a lama di coltello che assume la cresta dell’argine e per le caratteristiche tessiturali simili ad analoghi depositi di età nota situati nelle vicinanze, si ritiene che il deposito in oggetto possa esser riferito alla piccola età glaciale. studio integrato fito-geomorfologico ... ciali modellati in numerosi argini morenici. il deposito è coperto dal rododendreto (rhododendretum ferruginei) in modo pressoché continuo. parte del deposito si inserisce all’interno del limite superiore della vegetazione arborea; alcuni esemplari di larice si sono insediati sulla lunga morena laterale sinistra raggiungendo la quota di 2200 m. le geometrie degli argini morenici appartenenti alle unità sopra descritte suggeriscono alcune considerazioni sui limiti delle nevi, utili per datare i depositi glaciali e conseguentemente per inquadrare cronologicamente il substrato su cui si sono impostate le rocce montonate. i presunti valori della quota del limite delle nevi, assunti dai ghiacciai corrispondenti alle cinque unità individuate, sono indicati in tab 2. il valore del bzn locale è fornito dall’unità del cornetto ed è pari a 2680 m. l’unità di prabello e di campagneda si collocano nelle fasi iniziali ed intermedie dell’egesen, quelle di campascio di caspoggio e del passo degli ometti, nelle fasi tardive del daun. la differenza dell’abbassamento del limite delle nevi, tra le varie unità, in alcuni casi anche sensibile, indica che l’originale unica placca di ghiaccio si è disattivata per fasi successive da sud verso nord, abbandonando per ultimo il settore centrale in corrispondenza dell’alpe prabello. la disattivazione delle varie unità che vede nell’ordine l’unità del monte acquanera, l’unità del campascio di caspoggio, l’unità di campagneda, l’unità di alpe prabello e l’unità del cornetto, è avvalorata anche dal rispettivo grado di colonizzazione della vegetazione e dai rapporti geometrici di sovrapposizione dei relativi depositi. la superficie rocciosa che ospita le rocce montonate risulta quindi essere esposta da un’età superiore ai 13.000 anni bp; inoltre, nell’ipotesi di considerare i cambiamenti ambientali connessi solo a variazioni termiche, sulla base delle variazioni di quota del limite delle nevi, si può ritenere che nel momento in cui le rocce montonate erano attorniate dalle due lingue glaciali, le temperature medie annue si aggirassero su valori inferiori di circa 2,5 °c rispetto all’attuale, mentre quando il ghiacciaio stazionava nei pressi dell’alpe prabello potevano essere inferiori a poco più di 1 °c. 4.2 le comunità vegetali: ecologia e distribuzione in relazione alle geoforme nel campo di rocce montonate, la vegetazione si insedia preferenzialmente in corrispondenza di placche detritiche più o meno potenti, ubicate in diverse situazioni morfologiche. in particolare, le numerose fratture, orientate prevalentemente lungo due direttrici (nw÷se e wsw÷ene), individuano tra i dossi delle rocce montonate una serie di conche, di vallecole e di solchi, all’interno dei quali si raccoglie il detrito proveniente dalla degradazione delle rocce, in alcuni casi con spessori di qualche metro (fig. 4). la classificazione gerarchica dei rilievi fitosociologici (fig. 5) mostra la ripartizione dei rilievi in cinque gruppi principali, ecologicamente ben differenziati, distinti ad un valore di dissimilarità pari a 0,85: i primi tre cluster riuniscono le praterie igrofile e idro-igrofile ascrivibili alla classe scheuchzerio-caricetea nigrae, rilevate nelle depressioni, il quarto raggruppa le comunità distribuite sulle pareti rocciose (cystopteridion) e sulle coltri di alterazione (oxytropido-elynion), mentre il 76 unità del piano di campagneda (upc ). al piano di campagneda la vasta zona paludosa è sorretta da una spessa coltre di depositi glaciali, articolati in una successione di morene di accrezione e di sovrapposizione riferibili ad una lingua glaciale di ragguardevoli dimensioni (anche più di 500 m di larghezza) anch’essa diffluente dalla vedretta di pizzo scalino attraverso l’insellatura tra le quote 2911 e 2848. la maggior parte degli argini morenici mostrano profilo assai smussato ed alcuni di essi si identificano solo per una fitta serie di ondulazioni della superficie topografica, tra loro sub parallele. alcuni valli sono sostituiti da stone line. il deposito è ricoperto in modo continuo da curvuleti (caricetum curvulae), nardeti (sieversio nardetum strictae) e da localizzate praterie eliofile a festuca (festucetum scabriculmis); elevata è la pietrosità superficiale. l’unità ricopre le rocce del substrato con limiti netti e si sovrappone anche a depositi glaciali di ugual provenienza ma più antichi (unità di campascio di caspoggio). unità di campascio di caspoggio (uca ) costituisce una placca di depositi glaciali privi di espressione morfologica, che margina a nord il campo di rocce montonate. affiora nel settore settentrionale della zona e traccia i limiti della fronte di una lingua glaciale simile alla precedente ma che si spingeva più in basso nella valle. ricopre direttamente il substrato rocciose ed è a sua volta ricoperta dall’unità del piano di campagneda. il limite tra le due, di scarsa evidenza morfologica è tratteggiato da un allineamento di piccole risorgive, ristagni d’acqua, zone umide. sull’unità è presente un suolo sviluppato ed una stabilizzata copertura vegetale continua a nardo (sieversio nardetum strictae), a prateria pingue microterma (poion alpinae) e, intorno alle baite, a vegetazione dei riposi (rumicetum alpini). unità di alpe prabello (uap ) è il deposito che interferisce maggiormente con le rocce montonate, marginandole ad est, con un andamento spiccatamente sinusoidale, per una lunghezza di quasi tre chilometri. il lungo argine morenico, ben conservato, appoggia direttamente sulle nude rocce montonate. in alcuni tratti, sul lato orientale del deposito, sono presenti segmenti di morena che descrivono le fasi di ritiro di un ghiacciaio che veniva alimentato in parte dal versante tra il passo degli ometti ed il pizzo scalino ed in parte dalla vedretta di pizzo scalino, per transfluenza, lungo la già citata insellatura tra l’antecima di pizzo scalino ed il cornetto. e’ proprio in corrispondenza di questa maggior alimentazione che il deposito disegna la fronte principale più avanzata (quota di 2235 m), a ridosso dell’alpeggio di prabello e che ricopre maggiormente le rocce montonate. la vegetazione, costituita dal rododendreto (rhododendretum ferruginei) e dal nardeto (sieversionardetum strictae) ricopre questa unità in modo discontinuo a causa di una eccessiva pietrosità. il deposito glaciale in oggetto si sovrappone all’unità del piano di campagneda e del monte acquanera. unità del monte acquanera (uma ) è presente ai piedi del tratto di crinale che si sviluppa ad occidente del passo degli ometti e che culmina nel m. acquanera (2806 m). si tratta di depositi glag. parolo, a. carton & a. pirola quinto riunisce le comunità floristicamente e strutturalmente più complesse ascrivibili alle alleanze juniperion nanae, loiseleurio-vaccinion e nardion strictae, situate sui fianchi di collegamento tra i dossi e le depressioni (tab. 3). la ripartizione ecologica dei rilievi è comprovata anche dal diagramma di dispersione bidimensionale 77 fig. 4 carta geomorfologica del sistema di rocce montonate, che rappresenta con maggior dettaglio l’area di studio indicata in fig. 3. geomorphological map of the roches moutonnées system, showing in details the study area of the fig. 3. fig. 5 classificazione gerarchica dei rilievi fitosociologici. dendrogram of the phytosociological relevés. fig. 6 ordinamento metrico dei rilievi fitosociologici; gli assi i e ii esprimono rispettivamente il 22,28 % e il 15,33 % della varianza totale. metrical ordination of the phytosociological relevés; the 1st and the 2nd axes describe respectively the 22,28 % and the 15,33 % of the total variance. depressioni fianchi dossi pareti rocciose aggr ad erioph. angustifolium 2 caricetum limosae 1 caricetum pauperculae 1 drepanocl. revolv.-trichoph. cespitosi 2 1 sieversio-nardetum strictae 1 1 loiseleurio-cetrarietum 2 junipero-arctostaphyletum 2 aggr. a minuartia verna ed antenn. carpatica 3 aggr. a primula hirsuta 2 tab. 3 numero di rilievi per comunità vegetale e loro corrispondenza con le forme del rilievo. number of relevés per plant communities and their correspondence with the forms of relief. studio integrato fito-geomorfologico ... dei rilievi fitosociologici (fig. 6), che mostra cinque principali centri di raggruppamento, che nel complesso segregano bene i cinque gruppi ottenuti dalla classificazione gerarchica. le comunità individuate hanno raramente carattere transitorio, ma per lo più rappresentano aggruppamenti specializzati la cui dinamica è bloccata dalle condizioni ambientali estreme cui sono sottoposte. in fig. 7, un profilo longitudinale del sistema di rocce montonate offre la possibilità di osservare la disposizione preferenziale delle comunità vegetali rilevate, la cui distribuzione è prevalentemente correlata alla presenza di numerosi microhabitat differenziati, generati dall’eterogeneità morfologica del substrato. le conche di più grandi dimensioni (per lo più orientate nw÷se) presentano un fondo perfettamente pianeggiante con substrati saturi d’acqua. i loro fianchi assumono forme paraboloidi (i di fig. 8) se la frattura lungo la quale si sviluppa la conca è in posizione centrale rispetto alla depressione; prendono invece profili asimmetrici se la frattura è ubicata a margine della conca (ii di fig. 8). in questo secondo caso, ai piedi del fianco subverticale, si genera una falda detritica, a clasti più grossolani, decisamente più drenata rispetto alla conca. la stessa falda detritica si sviluppa anche qualora il lato a monte della conca sia limitato da una frattura ad andamento wsw÷ene, che genera una scarpata di alcuni metri di altezza. in quest’ultima situazione la conca presenta anche un maggior sviluppo equatoriale. la quasi perfetta orizzontalità del fondo è dovuta al fatto che le depressioni risultano occluse verso valle da una strozzatura prodotta da rocce montonate adiacenti o dalla presenza di un dorso roccioso in posizione centrale rispetto alla conca. la frazione fine, contenuta nei detriti presenti sul fondo, è percentualmente elevata e viene convogliata dal ruscellamento nivale e dalle piogge attive dalla primavera fino alle prime precipitazioni nevose autunnali. la frazione pelitica, inoltre, trattenendo maggiormente l’acqua, genera nelle conche porzioni di terreno a maggiore umidità che, nelle stagioni intermedie, gela fino al alcuni decimetri di profondità, rendendo superficialmente impermeabile il terreno. si genera così tra i dossi montonati un mosaico discontinuo di placche di terreno gelato, sul quale si rinvengono qua e là figure legate al gelo discontinuo. nelle depressioni si riscontrano popolamenti semisommersi paucispecifici ad eriophorum angustifolium (tab. 4) o ad eriophorum scheuchzeri in caso di ruscellamento superficiale; laddove il suolo subisce invece una legge78 fig. 7 transetto idealizzato lungo due rocce montonate in sequenza; la distribuzione dei tipi di vegetazione è correlata all’andamento del substrato, che influenza la disponibilità idrica, la durata della copertura nevosa e l’effetto del vento. 1aggruppamento rupicolo a primula hirsuta (tab. 8); 2comunità delle coltri detritiche di alterazione a minuartia verna ed antennaria carpatica (tab. 9); 3, 4, 8comunità igrofile delle depressioni: aggruppamento semi-sommerso paucispecifico ad eriophorum angustifolium (tab. 4); tricoforeto (drepanoclado revolventis-trichophoretum cespitosi, tab. 7), in condizioni edafiche più interrate con nardus stricta; caricetum pauperculae dei substrati acidi (tab. 5) e caricetum limosae (tab. 6) dei suoli poveri di nutrienti, che in estate sono soggetti a parziale emersione dalla falda acquifera; 5, 7pascoli a nardus stricta e carex sempervirens (sieversio-nardetum strictae; tab. 11); 6loiseleurio-cetrarietum (loiseleurio-vaccinion), variante pascolata a carex sempervirentis (tab. 12); 9comunità termofila a juniperus communis subsp. alpina, vaccinium gaultherioides e v. myrtillus (juniperion nanae, tab. 10); 10cenge con frammenti di brughiera extrasilvatica a rododendro (rhododendretum ferruginei), che costituisce la comunità strutturalmente più complessa del sistema di rocce montonate. idealised transect across two roches moutonnées in sequence; the distribution of the plant communities is linked to the forms of relief, that influence the water availability in the substratum, the snow cover and the wind effects. 1rupicolous community of primula hirsuta (tab. 8); 2community of minuartia verna and antennaria carpatica, typical of the alteration drift (tab. 9); 3, 4, 8wet communities of the depressions: half-submerged species-poor community of eriophorum angustifolium (tab. 4); community of trichophorum cespitosum (drepanoclado revolventis-trichophoretum cespitosi, tab. 7), with nardus stricta in dryness soils; caricetum pauperculae of the acid soils (tab. 5) and caricetum limosae (tab. 6), typical of nutrient-poor hollows, which are subject to dryness period during summer; 5, 7nardus stricta and carex sempervirens pastures (sieversio-nardetum strictae; tab. 11); 6loiseleurio-cetrarietum (loiseleurio-vaccinion), carex sempervirens grazed variant (tab. 12). 9termophilous community of juniperus communis subsp. alpina, vaccinium gaultherioides and v. myrtillus (juniperion nanae, tab. 10); 10ledges with fragment of acidocline alpenrose heaths (rhododendretum ferruginei), that is the more structured community of the roches moutonnées system. fig. 8 schema delle “trappole” di detrito ubicate tra le rocce e sulle rocce montonate. scheme showing the debris accumulation among and over the roches moutonnées. g. parolo, a. carton & a. pirola ra acidificazione si sviluppa il caricetum pauperculae (tab. 5), mentre il caricetum limosae (tab. 6) si insedia qualora i suoli siano soggetti ad un periodo estivo di abbassamento della falda acquifera. la presenza in queste comunità del nardo e delle specie ecologicamente connesse individua i settori maggiormente interrati e che subiscono un più intenso disturbo da parte del bestiame. nei casi in cui la conca non risulta occlusa verso valle o in corrispondenza di substrati più acclivi rispetto alle situazioni precedenti, si individuano vallecole sviluppate, tra le rocce montonate, per qualche centinaio di metri. i detriti che occupano queste depressioni, sempre impostate lungo fratture, sono decisamente più grossolani di quelli presenti nelle conche e di conseguenza il substrato risulta maggiormente drenato; in queste condizioni si assiste allo sviluppo di consorzi neutrofili o leggermente basifili a trichophorum cespitosum, carex lepidocarpa e carex nigra ascrivibili al drepanoclado revolventis-trichophoretum cespitosi (tab. 7). lungo le pareti subverticali delle rocce montonate, in genere orientate verso valle, si insediano comunità rupicole stabilizzate a primula hirsuta (tab. 8), ascrivibili all’alleanza cystopteridion, per la presenza di specie basifile o neutrofile dovuta all’apporto di basi da parte delle rocce serpentinitiche. lembi di detrito, atti ad ospitare placche discontinue di vegetazione, si individuano inoltre sulle superfici delle rocce montonate in corrispondenza di fratture (b di fig. 8). i detriti prevalentemente autoctoni, prodotti dalla degradazione, si assestano all’interno delle fratture e costituiscono lunghe bande che sottolineano la geometria delle discontinuità. si possono osservare 79 tab. 4 aggruppamento ad eriophorum angustifolium. community of eriophorum angustifolium. n° rilievo 12 13 specie dominante eriophorum angustifolium 3.3 3.3 classe carex echinata . + compagne callitriche palustris + . tab. 5 caricetum pauperculae (caricion nigrae). caricetum pauperculae (caricion nigrae). n° rilievo 10 diff. associazione carex paupercula 3.3 alleanza, ordine e classe carex nigra 2.2 juncus filiformis 1.2 eriophorum angustifolium 1.1 carex echinata + compagne nardus stricta 1.1 trichophorum cespitosum +.2 primula integrifolia + leontodon helveticus + potentilla erecta + agrostis rupestris + homogyne alpina + hieracium alpinum r phyteuma hemisphaericum r briofite 4.4 n° rilievo 1 2 11 diff. associazione bartsia alpina + 1.2 +.2 alleanza e ordine carex lepidocarpa 2.2 1.2 . parnassia palustris + + . selaginella selaginoides . + + carex davalliana 1.1 . . juncus alpinoarticulatus + . . classe carex nigra 4.4 1.1 2.2 eriophorum angustifolium 1.1 +.2 1.1 carex echinata + 1.2 1.1 carex paupercula . +.2 + juncus filiformis . 1.1 . compagne trichophorum cespitosum + 4.4 3.4 primula integrifolia + 3.3 2.2 leontodon helveticus + 1.1 + crepis aurea 1.1 + + potentilla erecta + 1.2 . soldanella alpina + + . nardus stricta . + +.2 salix breviserrata 1.2 . . taraxacum alpinum 1.1 . . polygonum viviparum 1.1 . . poa alpina + . . agrostis stolonifera + . . gentiana bavarica + . . deschampsia cespitosa + . . ligusticum mutellina . +.2 . agrostis rupestris . + . carex sempervirens . + . carex frigida . + . salix herbacea . + . sibbaldia procumbens . r . gentiana ramosa . r . homogyne alpina . . r briofite 1.2 1.2 3.3 tab. 6 caricetum limosae (rynchosporion albae). caricetum limosae (rynchosporion albae). n° rilievo 14 car. associazione carex limosa 5.5 alleanza, ordine e classe menyanthes trifoliata + carex nigra + eriophorum angustifolium + compagne trichophorum cespitosum + briofite + tab. 7 drepanoclado revolventis – trichophoretum cespitosi (caricion davallianae). drepanoclado revolventis – trichophoretum cespitosi (caricion davallianae). studio integrato fito-geomorfologico ... (fig. 9) mostra che la distribuzione dei rilievi risulta correlata preferenzialmente al grado di umidità del suolo (primo asse) ed alla rigidità delle condizioni ambientali (secondo asse), che è alta negli aggruppamenti rupicoli, detriticoli e acquatici, per diminuire nelle praterie pascolate, negli arbusteti nani e nelle fitocenosi igrofile più strutturate. grime (2001) sottolinea che le comunità 80 tab. 8 aggruppamento a primula hirsuta (cystopteridion). community of primula hirsuta (cystopteridion). tab. 9 ril. 15, 16, 17: aggruppamento a minuartia verna ed antennaria carpatica (oxytopydo-elynion); ril. 3: comunità di transizione verso lo junipero-arctostaphyletum, variante a f. scabriculmis (ril. 4). ril. 15, 16, 17: community of minuartia verna and antennaria carpatica (oxytopydo-elynion); ril. 3: transition community toward the junipero-arctostaphyletum, f. scabriculmis variant (ril. 4). n° rilievo 18 19 specie dominante primula hirsuta 2.2 2.2 alleanza asplenium viride 1.2 + cystopteris fragilis + + viola biflora (d) + 1.2 ordine e classe saxifraga paniculata . + compagne silene acaulis subsp. longiscapa + + minuartia verna subsp. verna + . draba aizoides subsp. aizoides + . campanula cochleariifolia + . aster alpinus + . senecio incanus subsp. carniolicus + . cardamine resedifolia + . juncus trifidus + . poa laxa . 1.1 phyteuma hemisphaericum . +.2 campanula scheuchzeri . + carex fimbriata . + astrantia minor . + huperzia selago . + briofite 1.1 2.2 n° rilievo 3 17 15 16 specie guida minuartia verna . + 1.1 1.2 antennaria carpatica (all.) . + +.2 + silene rupestris + + . + saxifraga paniculata + + + . alleanza, ordine e classe aster alpinus + 1.1 1.1 + silene acaulis subsp. longiscapa . + +.2 + agrostis alpina + . 1.1 1.2 thymus praecox subsp. polytrichus + . + . daphne striata . + . . erigeron uniflorus . . +.2 . draba aizoides . . +.2 . sedum atratum . . . + trasgr. caricetea curvulae phyteuma hemisphaericum + + . + senecio incanus subsp. carniolicus . r + + agrostis rupestris 1.1 2.2 . . pulsatilla vernalis . 1.1 + . hieracium alpinum . 1.1 + . euphrasia minima . + + . festuca scabriculmis subsp. luedii 1.1 . . . pulsatilla vernalis + . . . leontodon helveticus . + . . trifolium alpinum . r . . minuartia sedoides . . 1.1 . gentiana ramosa . . . + compagne primula hirsuta + 1.1 + + cardamine resedifolia . r r + poa alpina . . 1.1 + plantago serpentina 1.2 . . . astrantia minor + . . . juniperus communis subsp. alpina + . . . dianthus sylvestris + . . . phyteuma scheuchzeri + . . . ligusticum mutellina + . . . vaccinium gaultherioides . 2.2 . . carex sempervirens . + . . sempervivum montanum . + . . carex fimbriata . . 1.1 . campanula scheuchzeri . . +.2 . sedum alpestre . . . + briofite . 1.1 + . licheni . + . . cladonia pyxidata (l.) hoffm. . . . + cladonia merochlorophaea . asahina . . + anche placche di detrito di degradazione rimaste in loco sui dorsi delle rocce montonate nei tratti a bassa acclività (a di fig. 8). in entrambe queste situazioni si insedia una comunità a minuartia verna ed antennaria carpatica (ril. 15, 16, 17 di tab. 9); si tratta di una comunità fortemente stabilizzata dalle condizioni microclimatiche severe e dalla bassa disponibilità di elementi nutritivi. questa comunità, qualora insediata in situazioni edafiche migliori, è potenzialmente diretta verso lo junipero-arctostaphyletum (ril. 5), passando attraverso uno stadio a festuca scabriculmis (ril. 4), come testimoniato anche dal ril. 3, che rappresenta uno stadio intermedio tra le due comunità (tab. 10). lungo i fianchi ad inclinazione modesta (inferiore a 15 °c) si estendono i pascoli a nardo (sieversionardetum strictae, tab. 11), in cui è possibile individuare, in condizioni edafiche fresche, aspetti di contatto con la vegetazione delle torbiere; sulle superfici più aride e soggette ai venti, che ne asportano precocemente la copertura nevosa, si insedia una comunità microterma dominata da loiseleuria procumbens (tab. 12), sulla quale l’effetto del pascolamento favorisce la espansione di specie erbacee gravitanti nell’ambito dei caricetea curvulae e dell’alleanza nardion strictae, quali carex sempervirens, helictotrichon versicolor, leontodon helveticus e trifolium alpinum. 4.3 dinamica della vegetazione, strategie ecologiche ed organizzazione strutturale delle comunità le comunità vegetali che caratterizzano il sistema di rocce montonate rappresentano stadi dinamici la cui evoluzione e grado di complessità sono bloccati o fortemente rallentati dalla severità dei fattori ambientali. l’interpretazione ecologica del piano bidimensionale g. parolo, a. carton & a. pirola artico-alpine sono generalmente dominate da specie stress-tolleranti, nelle quali le basse temperature rappresentano la principale fonte di stress. i gruppi 2, 3 e 4 annoverano comunità adattate a vivere in condizioni ambientali molto severe ed improduttive, mentre nei gruppi 1 e 5 prevalgono fitocenosi tipiche di situazioni ambientali più permissive, dotate di una maggior disponibilità di nutrienti. la vegetazione dei dossi, qualora questi abbiano una curvatura molto accentuata, si presenta con popolamenti discontinui, dinamicamente stabili, in grado di resistere a condizioni ambientali estreme. laddove le rocce, a curvatura modesta, siano 81 n° rilievo 4 5 diff. associazione e alleanza juniperus communis subsp. alpina 2.2 4.4 sempervivum montanum (d) . +.2 ordine e classe vaccinium gaultherioides 1.2 1.1 rhododendron ferrugineum + 1.1 loiseleuria procumbens +.2 + vaccinium vitis-idaea + . variante a festuca scabriculmis festuca scabriculmis subsp. luedii 3.3 + potentilla grandiflora +.2 . bupleurum stellatum + . pedicularis tuberosa + . compagne carex sempervirens 2.2 1.1 daphne striata 1.1 + astrantia minor + + agrostis rupestris +.2 + pulsatilla vernalis r + carex fimbriata 1.2 . nardus stricta 1.1 . aster alpinus +.2 . agrostis alpina +.2 . bartsia alpina +.2 . anthoxantum alpinum +.2 . helictotrichon versicolor + . gentiana acaulis + . soldanella alpina + . primula hirsuta + . pinguicula vulgaris + . potentilla erecta + . pinus mugo subsp. mugo + . carduus defloratus + . leontodon hispidus + . parnassia palustris + . plantago serpentina + . poa alpina . 1.1 trifolium alpinum . 1.1 hieracium alpinum . + carex curvula . + veronica bellidioides . + gentiana ramosa . r solidago virgaurea subsp. minuta . + galium pumilum . + silene acaulis subsp. longiscapa . + antennaria carpatica . + silene rupestris . r carex capillaris . r campanula scheuchzeri . r n° rilievo 8 9 diff. associazione e alleanza nardus stricta 2.2 4.4 leontodon helveticus + 1.1 arnica montana + + geum montanum . + ordine e classe gentiana acaulis + + trifolium alpinum + + phyteuma hemisphaericum + + agrostis rupestris + + hieracium alpinum 1.2 . coeloglossum viride + . potentilla aurea . 2.2 helictotrichon versicolor . + compagne carex sempervirens 3.3 1.1 primula integrifolia 1.2 1.1 poa alpina + 1.2 soldanella alpina + 1.1 pulsatilla vernalis + +.2 astrantia minor + + galium pumilum + + campanula scheuchzeri r + carex fimbriata r + selaginella selaginoides r + daphne striata 2.2 . potentilla erecta 1.2 . loiseleuria procumbens + . rhododendron ferrugineum + . bartsia alpina + . rhinantus sp. + . pinguicula vulgaris + . primula hirsuta r . thesium alpinum r . crepis aurea . 3.3 festuca nigrescens . 1.1 carex lepidocarpa . 1.2 leontodon autumnalis subsp. palustris . +.2 deschampsia cespitosa . + ligusticum mutellina . + polygonum viviparum . + ranunculus montanus . + salix breviserrata . + homogyne alpina . + carex capillaris . + antennaria carpatica . + agrostis alpina . + silene acaulis subsp. longiscapa . + carex atrata subsp. atrata . + aster bellidiastrum . r licheni pycnothelia papillaria (ehrh.) l.m.doufur . 1.1 cladonia arbuscula (wallr.) flot. subsp. mitis (sandst.) ruoss . + cetraria islandica (l.) ach. . + cladonia pyxidata (l.) hoffm. . + briofite sphagnum sp. + . tab. 10 ril. 5: junipero-arctostaphyletum; ril. 4: idem, variante a festuca scabriculmis (juniperion nanae). ril. 5: junipero-arctostaphyletum; ril. 4: idem, festuca scabriculmis variant (juniperion nanae). tab. 11 ril. 8 sieversio-nardetum strictae; ril. 9 sieversionardetum strictae variante igrofila (nardion strictae). ril. 8 sieversio-nardetum strictae; ril. 9 sieversio-nardetum strictae, wet variant (nardion strictae). studio integrato fito-geomorfologico ... 82 tab. 12 loiseleurio-cetrarietum (loiseleurio-vaccinion), variante pascolata a carex sempervirentis. loiseleurio-cetrarietum (loiseleurio-vaccinion), carex sempervirens grazed variant. fig. 9 frammentazione in zolle della copertura vegetale, dovuta a processi dinamici regressivi. fragmentation of the vegetation cover, due to regressive dynamic processes. n° rilievo 6 7 car. associazione loiseleuria procumbens 3.3 4.4 alleanza asplenium viride 1.2 + cystopteris fragilis + + viola biflora (d) + 1.2 alleanza, ordine e classe juniperus communis subsp. alpina + r vaccinium gaultherioides + + hieracium alpinum + . rhododendron ferrugineum . + homogyne alpina . + trasgr. caricetea curvulae carex sempervirens 2.2 3.3 helictotrichon versicolor + 2.2 leontodon helveticus + 2.2 phyteuma hemisphaericum + + potentilla aurea + + gentiana ramosa + . pulsatilla vernalis + . trifolium alpinum . 2.2 agrostis rupestris . + nardus stricta . + compagne agrostis alpina 2.2 1.1 poa alpina 1.1 + primula hirsuta 1.2 + antennaria carpatica + + selaginella selaginoides + + salix retusa + . primula integrifolia . 1.1 carex nigra . +.2 astrantia minor . +.2 soldanella alpina . + silene rupestris . + solidago virgaurea subsp. minuta . + salix herbacea . + trichophorum cespitosum . + briofite polytrichum sp. + . tab. 13 valori di diversità (numero di specie, indice di shannon-weaver), di equitabilità (pielou) e di dominanza (simpson), calcolati per ciascun rilievo fitosociologico. diversity indexes (species richness, shannon-weaver index), evenness (pielou) and dominance (simpson), evaluated for every phytosociological relevé. cluster cl. 1 cl. 2 cl. 3 cl. 4 cl. 5 n° rilievo 1 2 11 10 12 13 14 3 17 15 16 18 19 4 5 6 7 8 9 n° specie 22 23 14 16 2 2 5 17 21 19 14 14 14 31 25 17 27 29 36 shannon 1,73 1,79 1,30 1,49 0,07 0,07 0,14 2,21 2,00 2,37 2,03 1,39 1,55 2,15 1,47 1,68 1,92 1,95 2,13 pielou 0,56 0,57 0,49 0,54 0,10 0,10 0,09 0,78 0,66 0,80 0,77 0,53 0,59 0,63 0,46 0,59 0,58 0,58 0,59 simpson 0,32 0,28 0,26 0,33 0,97 0,97 0,96 0,16 0,19 0,12 0,21 0,43 0,34 0,20 0,45 0,26 0,21 0,23 0,21 disposte consecutivamente su versanti che digradano costantemente, si può ipotizzare che tali comunità discontinue possano evolversi costituendo una cotica chiusa di collegamento tra i dossi e le depressioni. nelle depressioni, al contrario, il fattore che blocca lo sviluppo della vegetazione è rappresentato dalla costante saturazione idrica dei suoli, che li rende tipicamente anossici e microtermi. valori di ricchezza floristica (numero di specie), di diversità specifica (shannon & weaver, 1949), di dominanza (simpson, 1949) e di equitabilità (pielou, 1969) sono stati calcolati per ciascuno dei popolamenti rilevati con l’intento di dedurre informazioni sulla loro stabilità ecologica ed organizzazione strutturale (tab. 13). osservando i grafici in figg. 10, 11, 12, 13 il numero di specie è maggiore nel gruppo 5, che include le fitocenosi più strutturate ed evolute dal punto di vista dinamico. la diversità specifica, calcolata con l’indice di shannon, è alta sia in questi popolamenti sia nei popolamenti del gruppo 4, mentre assume valori via via più bassi negli altri tre gruppi. g. parolo, a. carton & a. pirola 83 tab. 14 dati stazionali dei rilievi fitosociologici. / environmental data of the phytosociological relevés. fig. 10 ricchezza specifica (numero di specie per rilevamento); 6 classi di valori dal simbolo più piccolo al più grande: ≤ 10 / 11-15 / 16-20 / 21-25 / 26-30 / ≥ 31. species richness (number of species per relevé); 6 classes of values from the smaller to the greater symbol: ≤ 10 / 11-15 / 16-20 / 21-25 / 26-30 / ≥ 31. fig. 12 equitabilità (indice di pielou); 5 classi di valori dal simbolo più piccolo al più grande: ≤ 0,40 / 0,41-0,50 / 0,51-0,60 / 0,61-0,70 / ≥ 0,71. evenness (pielou index); 5 classes of values from the smaller to the greater symbol: ≤ 0,40 / 0,41-0,50 / 0,51-0,60 / 0,61-0,70 / ≥ 0,71. fig. 13 dominanza (indice di simpson); 5 classi di valori dal simbolo più piccolo al più grande: ≤ 0,20 / 0,21-0,30 / 0,310,40 / 0,41-0,50 / ≥ 0,51. dominance (simpson index); 5 classes of values from the smaller to the greater symbol: ≤ 0,20 / 0,21-0,30 / 0,31-0,40 / 0,410,50 / ≥ 0,51. fig. 11 diversità specifica (indice di shannon-weaver); 4 classi di valori dal simbolo più piccolo al più grande: ≤ 1,00 / 1,01-1,50 / 1,51-2,00 / ≥ 2,01. species diversity of vascular plants (shannon-weaver index); 4 classes of values from the smaller to the greater symbol: ≤ 1,00 / 1,01-1,50 / 1,51-2,00 / ≥ 2,01. n° rilievo 1 2 11 10 12 13 14 3 17 15 16 18 19 4 5 6 7 8 9 altitudine 2260 2281 2285 2285 2285 2285 2275 2252 2260 2270 2245 2282 2200 2235 2260 2245 2270 2260 2265 esposizione nnw w nw n nnw sw n w se n n se n inclinazione (°) 0 4 0 0 0 0 0 25 0-15 5 2 90 80 25 5-30 10 15 15 15 superficie (m2) 12 20 1,5 2,5 2,5 2 30 5 2 6 3 1,2 2 12 5 5 25 8 15 cop. % str. arbust. 25 85 1 1 altezza (cm) 10-30 5-35 10-25 10-25 cop. % str. erb. 90 95 80 70 35 35 80 8 50 10 15 15 20 85 25 75 95 85 100 altezza (cm) 1-20 2-15 1-25 1-25 30-40 15-40 0-15 5-10 1-10 2 (5) 2 (5) 3-10 5-10 5-25 1-10 3-20 2-15 3-20 5-20 cop. % str. musc. 5 5 50 70 altezza (cm) 2 2 2* 2* n° specie vascolari 22 23 14 16 2 2 6 17 21 19 14 14 14 31 25 17 27 29 36 studio integrato fito-geomorfologico ... a questo proposito è interessante notare che i valori medio-alti di diversità assunti dai popolamenti del 4° gruppo possono mettere in dubbio l’effettiva esistenza di condizioni ambientali estreme, come invece affermerebbe la loro posizione rispetto al secondo asse dell’ordinamento metrico dei rilievi; questa apparente anomalia può essere spiegata considerando in modo integrato anche i valori di equitabilità e di dominanza. dall’analisi dei due parametri (figg. 12, 13) è possibile dedurre che il 4° gruppo, caratterizzato da una ricchezza di specie piuttosto contenuta, raggiunge alti livelli di diversità poiché le specie sono ben equiripartite all’interno dei popolamenti e, di conseguenza, non si verifica la dominanza di una o più specie sulle altre. tale comportamento è in accordo con le strategie ecologiche formulate da grime (2001), il quale afferma che la diversità è elevata in comunità dominate da specie stresstolleranti, nelle quali condizioni ambientali molto severe selezionano un numero basso di specie ecologicamente ben specializzate ed equiripartite per quanto riguarda la copertura percentuale. il gruppo 1 e, in particolare, il 5 corrispondono a popolamenti con un maggior numero di specie, ma con diversità specifica leggermente meno elevata che indica, per queste comunità sottoposte a condizioni ambientali più permissive, una maggior potenzialità di espressione dinamica. qualora la pressione ambientale dovesse manifestarsi in modo molto marcato si assisterebbe invece ad una drastica diminuzione della ricchezza e della diversità specifica e alla formazione di popolamenti paucispecifici dominati da specie ad ecologia molto specializzata; è il caso dei gruppi 2 e 3, in cui una specie, rispettivamente eriophorum angustifolium e carex limosa, assume coperture elevate grazie alla capacità incontrastata di colonizzare ambienti particolarmente selettivi, ove poche altre specie riescono a stento ad affermarsi. inoltre, le comunità vegetali possono essere soggette a regressione dinamica, in occasione di eventi climatici non ordinari, quali la prolungata sommersione della vegetazione nelle depressioni, causata da abbondanti precipitazioni, o l’inasprimento dei fenomeni erosivi sui dossi e sui fianchi rocciosi dovuti a prolungato ruscellamento superficiale. nell’area indagata, numerosi riscontri porterebbero a supporre che, in occasione di eventi piovosi eccezionali, si sia verificata l’asportazione della copertura erbacea, rimossa da processi di ruscellamento superficiale delle acque piovane, convogliate in percorsi preferenziali, lasciando isolate zolle di vegetazione sulla roccia nuda (ril. 6; comunità 6 di fig. 10; fig. 9). a questo processo, tipicamente estivo, si deve aggiungere il lento scivolamento gravitativo di grosse porzioni di suolo, ricoperto da vegetazione, lungo i pendii rocciosi caratterizzati da una discreta inclinazione, probabilmente causato da un periodico ciclo giornaliero di fusione e solidificazione di ghiaccio ipogeo, a diretto contatto con la superficie rocciosa, che si verificherebbe nella tarda primavera e nel primo autunno. 5. conclusioni l’individuazione di superfici geomorfologiche di aspetto unitario, riferibili ad una ben definita unità territoriale, rappresenta un modello di analisi paesaggistica in cui le componenti fisiche e biotiche risultano interconnesse ed inscindibili tra loro. nel sistema di rocce montonate in oggetto l’espressione floristica e strutturale delle comunità vegetali è fortemente determinata dall’andamento morfologico del substrato, poiché l’alternarsi di dossi e di depressioni condiziona la distribuzione idrica, l’esposizione al vento, l’orientamento e l’accumulo differenziato della sostanza organica e del manto nevoso. i tipi di vegetazione, almeno potenzialmente collegati da rapporti seriali sulla medesima geoforma, catenali tra dossi e depressioni, assumono una distribuzione a mosaico in cui si riscontrano, generalmente, transizioni ecotonali brusche per la rapida variazione, anche su brevi distanze, dei fattori micro-ambientali. questi ultimi influenzano la ricchezza floristica e la diversità specifica delle comunità vegetali, favorendo l’affermazione di specie a strategia stress-tollerante. il sistema di rocce montonate studiato può essere considerato un elemento fito-geomorfologico unitario del paesaggio (geosigmeto), poiché in esso è possibile riconoscere complessi di vegetazione adiacenti, che mostrano modelli distributivi caratteristici e ripetibili nello spazio. nonostante l’attività riscontrata dei processi geomorfologici e climatici, si può supporre che le comunità individuate siano potenzialmente dirette, almeno nelle situazioni edafiche migliori, verso il rhododendretum ferruginei, come osservato appena più a valle attorno ai 2100 m e sul cordone morenico dell’unità dell’alpe prabello a 2300 m. un’analisi sinfitosociologica delle comunità individuate consentirebbe infatti il riconoscimento di piccole geosigmassociazioni (hypogeosigmassociation sensu theurillat, 1992b), la cui definizione necessita di uno studio specifico esteso alla più ampia realtà territoriale di appartenenza. in conclusione si può evincere come lo studio della vegetazione e del paesaggio vegetale, in particolare in ambienti alpini, sia difficilmente svincolabile dall’analisi degli aspetti geomorfologici; il riconoscimento delle geoforme consente di estrapolare numerose informazioni di carattere fisico-strutturale, quali ad esempio l’agente morfogenetico e il rispettivo grado di attività, l’età del deposito ed informazioni pedologiche di massima (quest’ultime completate dall’analisi della litologia), che rappresentano utili strumenti di supporto nell’interpretazione della diversità vegetale di un territorio. quest’ultima si rivela un buon indicatore nella caratterizzazione di forme e processi geomorfologici, in relazione alla presenza di rapporti di dipendenza statisticamente ripetibili in condizioni ecologiche equivalenti. schema sintassonomico classe scheuchzerio-caricetea nigrae nom. mut. propos. ex steiner 1992 aggruppamento ad eriophorum angustifolium ordine scheuchzerietalia palustris nordhagen 1936 all. rhyncosporion albae koch 1926 caricetum limosae (osvald 1923) em. dierßen 1982 ordine caricetalia nigrae nom. mut. propos. ex steiner 1992 all. caricion nigrae nom. mut. propos. ex steiner 1992 eriophoretum scheuchzeri rübel 1912 84 g. parolo, a. carton & a. pirola caricetum pauperculae nom. mut. propos. ex steiner 1992 ordine caricetalia davallianae br.-bl. 1949 all. caricion davallianae klika 1934 drepanoclado revolventis-trichophoretum cespitosi nom. mut. propos. ex steiner 1992 classe caricetea curvulae br.-bl. 1948 ordine caricetalia curvulae br.-bl. in br.-bl. et jenny 1926 all. nardion strictae br.-bl. 1926 sieversio-nardetum strictae lüdi 1948 classe vaccinio-piceetea br.-bl. in br.-bl. et al. 1939 ordine loseleurio-vaccinietalia eggler 1952 all. loiseleurio-vaccinion br.-bl. in br.-bl. et jenny 1926 loiseleurio-cetrarietum br.-bl. et al. 1939 all. juniperion nanae br.-bl. et al. 1939 junipero-arctostaphyletum br.-bl. ex haffter in br.-bl. et al. 1939 all. rhododendro-vaccinion j. br.-bl. ex g. br.-bl. et j. br.-bl. 1931 rhododendretum ferruginei rübel 1911 classe asplenietea trichomanis (br.-bl. in meier et br.-bl. 1934) oberd. 1977 ordine potentilletalia caulescentis br.-bl. in br.-bl. et jenny 1926 all. cystopteridion richard 1972 aggruppamento a primula hirsuta. classe elyno-seslerietea br.-bl. 1948 ordine seslerietalia caeruleae br.-bl. in br.-bl. et jenny 1926 all. oxytropido-elynion br.-bl. 1949 aggruppamento a minuartia verna ed antennaria carpatica ringraziamenti un sentito ringraziamento alla dott. m. brusoni per la rilettura critica del testo e alla prof. m. valcuvia, alla dott.sa c. delucchi e alla dott.sa d. chiappetta per l’identificazione delle specie licheniche. bibliografia aa.vv. (1970) carta geologica d’italia. fogli 7-18 (pizzo bernina, sondrio), scala 1:100.000. servizio geologico d’italia. e.i.r.a. firenze. aeschimann d., lauber k., moser d.m. & theurillat j.p. (2004) flora alpina. 3 voll. zanichelli, bologna. becker t. & dierschke h. (2005) primärsukzession im gletschervorfeld des obersulzbachkess (hohe tauern, osterreich) eine zeitreihe über fast 150 jahre. tuexenia 25: 111-140. benning l.g. & sidler d. m. (1992) petrographie der margnaund der sella-decke und des malencoserpentinites zwischen pass d’ur und pizzo scalino (val malenco, provinz sondrio, italien). schweiz. mineral. petrogr. mitt. 72: 213-224. bertin l. (2003) studio integrato fito-geomorfologico in ambiente alpino (val d’aviolo, lombardia). un approccio cartografico. tesi di dottorato in geobotanica ed ecologia sperimentale, xvi ciclo. dipartimento di ecologia del territorio, università degli studi di pavia. blasi c. (1996) il fitoclima d’italia. giorn. bot. ital. 130(1):166-176. braun-blanquet j. (1964) pflanzensoziologie. grundzüge der vegetationskunde. springer verlag. wien. braun-blanquet j. (1972) plant sociology. facsimile of the edition of 1932. hafner publishing company, new york. caccianiga m. & andreis c. (2004) pioneer herbaceous vegetation on glacier forelands in the italian alps. phytocoenologia 34: 55-89. cannone n. & gerdol r. (2003) vegetation as an ecological indicator of surface instability in rock glaciers. artic, antartic and alpine research 35 (3): 384-390. carbinier r. (1966) relations entre cryoturbation, solifluxion et groupements vègètaux dans les hautesvosges (france). oecol. pl., 4: 335-367. carte topographique de la suisse (1910) f. poschiavo, ed. a colori. scala 1:100.000. del favero r. (a cura di) (2002) i tipi forestali nella regione lombardia. regione lombardia, cierre edizioni. delpech r. (1985) relations entre un type de modèle périglaciaire (réseaux de buttes gazonnées ou “thufurs”) et les végétations d’altitude incidences phytosociologiques. colloques phytosociologiques, xiii: 221-230. ellenberg h. (1988) vegetation ecology of central europe. 4th ed., cambridge university press, cambridge. eggensberger p. (1994) die pflanzengesellschaften der subalpinen und alpinen stufe der ammergauer alpen und ihre stellung in den ostalpen . bayerische botanische gesellschaft. münchen. gehu j.-m. (1988) l’analyse symphytosociologique et geosymphytosociologique de l’espace. théorie et méthodologie. colloques phytosociologiques, xvii: 11-46. gehu j.-m. & rivas-martinez s. (1981) notions fondamentales de phytosociologie. ber. int. simp. int. vereinigung vegetationsk: 5-33. gerdol r., ferrari c., piccoli f. & tomaselli m. (1985) vegetation and geomorphology in a fossil glacial cirque of the northern apennines (italy). colloques phytosociologiques, xiii, 293 316. gerdol r. & smiraglia c. (1990) correlation between vegetation pattern and micromorphology in periglacial areas of the central alps. pirineo, 135: 13-28. gerdol r. & tomaselli m. (1997) vegetation of wetlands in the dolomites. dissertationes botanicae. band 281. giacomini v. & pirola a. (1957) osservazioni geobotaniche su alcni esempi di fenomeni crionivali nelle alpi retiche. bollettino dell’istituto botanico dell’università di catania, 1957, serie ii, vol. i : 138-148. gillet f. (1985) analyse concrète et théorique des relations a différent niveaux de perception phytoecologique entre végétation forestière et géomorphologie dans le jura nord-occidental. colloques phy85studio integrato fito-geomorfologico ... tosociologiques, xiii : 101-131. godenzi a. (1957) ricerche sulla morfologia glaciale e geomorfogenesi nella regione fra il gruppo del bernina e la valle dell’adda con particolare riguardo alla valle di poschiavo. tesi di laurea discussa presso la facoltà di scienze naturali dell’università di friborgo. 1-122; tipografia menghini, poschiavo. grabherr g. & mucina l. (1993) die pflanzengesellschaften osterreichs. teil ii. gustav fischer verlag, jena. grime j.p. (2001) plant strategies, vegetation processes, and ecosystem properties. j. p. grime., 2nd ed., wiley. gross g., kerschner h. & patzel g. (1977) methodische untersuchungen über die schneegrenze in alpinen gletschergebieten . zeitschr. fur gletscherkunde und glazialgeologie, xii, 2 (1976): 223-251. hoersch b., braun g. & schmidt u. (2002) relation between landform and vegetation in alpine regions of wallis, switzerland. a multiscale remote sensing and gis approach. computers, environment and urban systems 26:113-139. istituto geografico militare austriaco (1833) carta topografica del regno lombardo veneto. foglio c2. scala 1:86.400. kerschner h. (1976) das daun und das egesen stadium in ausgewählten tälern der zentralalpen von nordtirol und graubünden. diss. univ. innsbruck. klug-pümpel b. (1982) effects on species distribution and phytomass variations in a caricetum curvulae stand. vegetatio 48: 249-254. körner c. (1999) alpine plant life. springer-verlag, berlin. kozlowska a. & raczkowska z., 2002 vegetation as a tool in the characterisation of geomorphological forms and processes: an example from the abisko mountains. geografiska annaler, 84 (3-4): 233-244. maisch m. (1982) zur gletscher und klimageschichte des alpinen spätglazials. geographica helvetica, 2, 93-104. marinelli o. (1928) il limite delle nevi nel caracorùm e nell’himalaya occidentale. spedizione italiana de filippi. risultati geologici e geografici pubblicati sotto la direzione di g. dainelli. serie ii, 4: 63-212. nangeroni g. (1930) morene stadiarie nella val malenco. atti soc. it. sc. nat., lxix: 2-21. milano. oriolo g. (2001) naked rush swards (oxytropidoelynion br.-bl. 1949 ) on the alps and the apennines and their syntaxonomical position. fitosociologia, 38 (1): 91-102. ozenda p. (1985) la végétation de la chaîne alpine dans l’espace montagnard européen. masson, paris. panizza m. (1980) interdisciplinarietà fra ricerche sulla vegetazione e ricerche di geomorfologia. in: aa.vv., atti del seminario “la cartografia della vegetazione per la gestione del territorio”. regione emilia-romagna e c.n.r. parolo g., (2003) rapporti causali tra vegetazione e geoforme in paesaggi alpino-nivali nell’area del p.zo scalino (val malenco, provincia di sondrio). tesi di dottorato in geobotanica ed ecologia sperimentale, xvi ciclo. dipartimento di ecologia del territorio, università degli studi di pavia. pedrotti f., gafta d., martinelli m., patella scola a. & barbieri f. (1997) le unità ambientali del parco nazionale dello stelvio. l’uomo e l’ambiente 28, università di camerino: 1-103. pielou e.c. (1969) an introduction to mathematical ecology. wiley, new york. pirola a. (1959) contributo allo studio dei rapporti tra vegetazione e fenomeni crionivali nelle alpi retiche. delpinoa, vol. 1, pp. 31-41. pirola a. (1962) osservazioni sui cuscinetti erbosi nella valle di livigno (alpi retiche). atti istituto botanico dell’università-laboratorio crittogamico pavia, serie v, vol. xx: 1-11. pirola a., cannone n., rossi g. & zurli m. (1998) la vegetazione degli ambienti periglaciali e la sua tutela. atti del convegno internazionale: “ghiacciai e aree protette: conoscenza, conservazione, valorizzazione”, sondrio, 30 ottobre 1997. pirola a. & credaro v. (1994) osservazioni sul dinamismo della vegetazione di morena recente nel gruppo del bernina. fitosociologia, 27: 139-149. podani j. (2001) syn-tax 2000 computer program for data analysis in ecology and systematics. scienza publishing. budapest. poldini l. & oriolo g. (1997) la vegetazione dei pascoli a nardus stricta e delle praterie subalpine acidofile in friuli (ne-italia). fitosociologia, 34: 127-158. richard j.-l. (1987) dynamique de la végétation sur le marges glaciaires récentes de la réserve d’aletsch (alpes valaisannes, suisse). 15 ans d’observations dans les placettes-témoin (1971-1986). botanica helvetica 97/2 : 265-275. rossi g., pirola a. & zurli m. (1998) relazioni vegetazione-suolo nel paesaggio periglaciale alpino: i cuscinetti erbosi al passo d’eira, livigno (alpi retiche). archivio geobotanico, 4 (2): 193-200 shannon c.e. & weaver w. (1949) the mathematical theory of communication. urbana, il. univ. illinois press. simpson e.h. (1949) measurement of diversity. nature, 163: 688. staub r. (1946 ) geologische karte der berninagruppe und iher umgebung im oberengadìn, bergell, val malenco, puschlav und livigno. masstab 1:50.000. geologische spezialkarte no. 18. geologischen kommission der schweiz. theurillat j.-p., 1992a l’analyse du paysage végétal en symphytocoenologie: ses niveaux et leurs domaines spatiaux”. bull. ecol., 23 (1-2): 83-92. theurillat j.-p., 1992b étude et cartographie du paysage végétal (symphytocoenologie) dans la région d’aletsch (valais, suisse)”. commission géobotanique de l’académie suisse des sciences naturelles. lausanne. tomaselli m. & agostini n. (1990) vegetation patterns and dynamics on a rock glacier in the northern apennines. pirineos, 136: 33-46. venzo s. (1971) gli stadi tardo-wurmiani e post-wurmiani nelle alpi insubriche valtellinesi. la valtellina da chiuro a delebio, la val malenco e la val masino. atti soc. it. sc. nat. e museo civ. st. nat.112 (2): 161-276. pavia. 86 ms. ricevuto il 30 novembre 2004 testo definitivo ricevuto il 2 agosto 2005 ms. received: november 30, 2004 final text received: august 2, 2005. g. parolo, a. carton & a. pirola imp. bellucci & sseeggnnaallaazziioonnee ddii nnuuoovvii ddeeppoossiittii ppiirrooccllaassttiiccii iinntteerrccaallaattii aallllee ssuucccceessssiioonnii ccoonnttiinneennttaallii ddeell pplleeiissttoocceennee ssuuppeerriioorree--oolloocceennee ddeellllaa ppoorrzziioonnee nnoorrdd--oorriieennttaallee ddeellllaa ppiiaannaa ccaammppaannaa ffrraanncceessccaa bbeelllluuccccii11,, nniiccoolleettttaa ssaannttaannggeelloo22,, aannttoonniioo ssaannttoo33 1dipartimento di geofisica e vulcanologia, università di napoli “federico ii” 2dipartimento di scienze della terra, università di napoli “federico ii” 3dipartimento di ingegneria geotecnica -sezione di geologia applicatauniversità di napoli “federico ii” riassunto in questa nota vengono segnalati nuovi affioramenti di depositi piroclastici da caduta e da flusso rinvenuti lungo il margine nord-orientale della piana campana ed intercalati a formazioni clastiche tardo quaternarie. i dati raccolti si riferiscono a depositi vulcanoclastici rinvenuti sia al letto che al tetto della formazione dell’ “ignimbrite campana” (ic) e da essa chiaramente separati e distinti per la presenza di paleosuoli, depositi fluviali e/o di superfici di erosione. in particolare sono stati riconosciuti due importanti eventi eruttivi pre-ic: il più antico è costituito da livelli di pomici da caduta clinostratificate al piede dei versanti carbonatici e caratterizzati da pomici bianco-grigiastre con diametro medio di 0,5 cm e spessore di circa 50 cm. su questi livelli da caduta poggia, con chiaro contatto erosionale, un pumice flow di colore giallastro che presenta spessori variabile tra i 2 e 6 metri. gli affioramenti più significativi sono localizzati nei dintorni di maddaloni e di durazzano ed in entrambe le località, il pumice flow giallastro è ricoperto dalla formazione dell’i c. in aree più interne rispetto alla piana campana, precisamente nella zona di solopaca, sono stati rilevati altri limitati affioramenti di piroclastiti antiche, costituite da alcuni metri di cineriti e pomici grigio nerastre molto alterate e fortemente cementate su cui poggiano depositi di conoide terrazzati, ricoperti lateralmente dai depositi dell’ ic. al tetto dell’ic, e da essa separato per la presenza di un paleosuolo o di depositi fluviali interposti, abbiamo rinvenuto in tutta l’area investigata un altro livello piroclastico da caduta caratterizzato dalla alternanza di cineriti bianche stratificate e livelli pomicei biancastri con spessore totale variabile tra i 50 cm ed i 200 cm. i dati stratigrafici raccolti, oltre a fornire preziose informazioni sull’attività eruttiva tardo pleistocenica dell’ area della piana campana, potranno in futuro contribuire a identificare nuovi livelli marker per la stratigrafia dei depositi tardo quaternari del margine tirrenico campano. abstract the main aim of this paper is to signal some new outcrops of pyroclastic deposits along the northern rim of the campanian plain, (province of caserta); the study refers particularly to pyroclastic successions located both at the base and at the bottom of the “ignimbrite campana” (ic), the most widespread volcanic formation in the area. the oldest deposits in the area have been found near the solopaca village, at the northern sector of the studied area; they are made up by alternating black and grey pumiceous levels some meters thick, and are covered by poligenic conglomerates of alluvial fan that can be chronologically ascribed to the end of middle pleistocene. in the surroundings of maddaloni and durazzano however, the deposits standing below the ic formation are characterized by the presence of two distinct pyroclastic units. the oldest one is represented by a pyroclastic fall deposit, at least 50 cm thick, included within slope or alluvial fan deposits. the youngest is made up by a yellow pumices flow with a thickness variable between 2 and 10 m, which always covers with erosional contact, the above described slope or alluvial fan deposits. at the top of ic formation another important pyroclastic level has been found all over the studied area. it is made up by white layered ash fall deposits covered by a massive, yellowish pumiceous level and its total thickness range is from 0,5 to 1 meter. all these new outcrops have been sampled for sedimentological, chemical and petrographical analysis that are still in progress, in order to identify their origin and to better define their chronological and stratigraphical position within the complex volcanic history of the campania plain. parole chiave: depositi piroclastici; pleistocene superiore; pianura campana; appennino meridionale. keywords: pyroclastic deposits; upper pleistocene; campanian plain; southern appenines il quaternario italian journal of quaternary sciences 1166(2), 2003, 279-287 11.. iinnttrroodduuzziioonnee in questa nota vengono segnalati nuovi affioramenti di depositi piroclastici da caduta e da flusso rinvenuti lungo il margine nord-orientale della piana campana, durante il rilevamento del nuovo foglio “caserta est” della nuova carta geologica d’italia in scala 1:50.000 (progetto carg). in quest’area la formazione quaternaria affiorante più diffusa è senz’altro rappresentata dall’ “ignimbrite campana” (ic) che costituisce una coltre con spessore variabile tra i 30 ed i 50 metri (barberi et al., 1978; di girolamo, 1968; di girolamo et al., 1973; 1984) e la cui messa in posto è avvenuta circa 39 ka (de vivo et al., 2001). i dati raccolti si riferiscono a depositi vulcanoclastici (fig. 1) rinvenuti sia al letto che al tetto di questa importante formazione vulcanica e da essa chiaramente separati e distinti per la presenza di paleosuoli, depositi fluviali e/o di superfici di erosione. tali depositi non erano segnalati nella precedente cartografia geologica ufficiale. 280 f. bellucci, n. santangelo & a. santo 22.. iill qquuaaddrroo ggeeoollooggiiccoo ee ggeeoommoorrffoollooggiiccoo numerosi sono i lavori che si sono occupati della ricostruzione della stratigrafia del sottosuolo della piana campana e della sua evoluzione durante il quaternario (d’erasmo, 1931; ippolito et al., 1973; aprile & ortolani, 1978; brancaccio et al., 1991; 1994; romano et al., 1994; aprile & toccaceli, 2002). romano et ali. (1994) hanno effettuato una ricostruzione dettagliata della stratigrafia superficiale (primi 200 metri) della piana evidenziando la presenza di sei unità stratigrafiche di ambiente variabile tra marino, transizionale e continentale, di età compresa tra il pleistocene medio-superiore e l’olocene. essi stabiliscono che l’intera pianura è stata subsidente durante la prima metà del pleistocene superiore, consentendo il permanere di un ambiente di sedimentazione marino nonostante l’intensa attività piroclastica registrata verso la fine di questo intervallo. nella seconda metà del pleistocene superiore invece viene registrata una netta diminuzione della subsidenza che, in coincidenza con l’oscillazione eustatica negativa dello stadio isotopico 2, ha consentito l’emersione definitiva dell’area. la morfologia dei settori perimetrali della piana campana è fortemente condizionata dalla presenza della formazione dell’ ic una imponente coltre piroclastica da flusso con spessori variabili tra i 30 ed i 50 metri che ha colmato tutte le depressioni morfologiche preesistenti (strutturali e incisioni fluviali) e creato un vasto plateau deposizionale. questa estesa formazione vulcanica, datata dapprima 37 ka (deino et al., 1994) e successivamente 39 ka (de vivo et al., 2001), rappresenta un importante marker stratigrafico avendo un vastissimo areale di affioramento (circa 3800km2) ed essendo facilmente riconoscibile sia in affioramento che da dati di sondaggio per le sue particolari caratteristiche litologiche. sebbene numerosi studi indichino i campi flegrei come centro di emissione di questa grande eruzione (barberi et al., 1991; fisher et al., 1993; orsi et al., 1999; rosi et al., 1999; ort et al., 1999) recenti indagini (rolandi et al., 2003) contraddicono questo modello e rivalutano l’ ipotesi , già avanzata in passato (di girolamo, 1968; 1978; di girolamo et al., 1984; barberi et al., 1978) di un’eruzione fissurale lungo sistemi di fratture parallele alle faglie peritirreniche che bordano la piana campana. la presenza di questa potente coltre ignimbritica ha obliterato gli affioramenti di depositi quaternari più antichi che sono molto limitati e concentrati nei settori bordieri della piana. romano et al. (1994) segnalano la presenza di depositi marini e vulcanoclastici sottostanti all’ic nei dintorni di maddaloni e cancello e, sulla base di stratigrafie di sondaggi, in tutto il sottosuolo della piana. de vivo et al. (2001) segnalano la presenza di deposti piroclastici ed ignimbritici datati tra 157 e 205 ka nei dintorni di taurano, lungo il margine orientale della piana. aprile & toccaceli (2002) segnalano la presenza nel sottosuolo della piana del sarno di una formazione ignimbritica sottostante all’ic e la correlano con l’ignimbrite di taurano di de vivo et al., 2001. rolandi et al. (2003) inoltre indicano la presenza di altri depositi ignimbritici antichi in varie località bordiere della piana (penisola sorrentina e monti di caserta) e li datano rispettivamente a 245 ka, 289 ka (ignimbriti di seiano) e 116 ka (ignimbrite di durazzano). per quanto concerne i depositi successivi alla messa in posto dell’ic, essi sono costituiti da depositi continentali alluvionali e di versante, rappresentati prevalentemente da depositi piroclastici rimaneggiati, cui sono intercalati e/o sovrapposti depositi piroclastici da caduta. in particolare nella zona di nostro interesse (fig. 1) di girolamo (1968) segnala la presenza di piroclastiti stratificate costituite da alternanze di livelli cineritici e pomicei poggianti su un paleosuolo a tetto dell’ic, in tutta l’area a sud di caserta ( s.nicola la strada, s.marco evangelista e maddaloni) e, a ne di caserta, nella valle di maddaloni, ricostruendone l’andamento degli spessori che aumentano verso sud. cole & scarpati (1993) segnalano la presenza di depositi piroclastici da caduta più recenti dell’ic, oltre che nelle stesse aree individuate da di girolamo (1968), anche a no di caserta presso s. angelo in formis. entrambi gli autori interpretano questi depositi come i prodotti distali della formazione tufo giallo napoletano datata 12 ka (alessio et fig. 1 ubicazione degli affioramenti studiati: 1) affioramenti delle piroclastiti post ignimbrite campana; 2) affioramenti delle piroclastiti pre ignimbrite campana. location map of the studied outcrops. 1) outcrops of post campanian ignimbrite pyroclastic deposits; 2) outcrops of pre ic piroclastic deposits. al., 1971; 1973; rosi & sbrana,1987; scandone et al.,1991). inoltre, nella zona immediatamente a sud dell’area in studio, nei dintorni di giugliano, viene segnalata la presenza di un deposito da flusso piroclastico (“tufo di giugliano”) datato 18 ka da de vivo et al. (2001) e 23 ka da rolandi et al., (2003). tale deposito risulta caratterizzato da un’alternanza di livelli cineritico sabbiosi a struttura massiva intercalati da livelli pomicei da caduta, presenta alla base un paleosuolo ed è sovrapposto all’ic. 33.. ii lliivveellllii pprree--iicc gli affioramenti più significativi sono localizzati nei dintorni di maddaloni, durazzano e solopaca e sono intercalati a successioni continentali tardo pleistoceniche riconducibili a detriti di versante, antichi conoidi alluvionali e depositi fluvio-palustri. le descrizioni stratigrafiche e le sezioni geologiche sono state realizzate spesso grazie a tagli “freschi” legati alla coltivazione di alcune cave. 33..11.. llooccaalliittàà ccaarrmmiiaannoo –– mmaaddddaalloonnii lungo il bordo sud-occidentale dei monti di durazzano, in località “carmiano”, nei pressi del cimitero di maddaloni, è possibile osservare la sovrapposizione stratigrafica dell’ic su prodotti piroclastici più antichi. questo importante affioramento è emerso grazie ai lavori di scavo di una cava ed era già stato segnalato in romano et al. (1994). in particolare tali autori evidenziavano la presenza di pomici e cineriti antiche preic, senza però soffermarsi sugli aspetti stratigrafici di dettaglio. i lavori di scavo ed i movimenti di terra nella cava hanno quasi del tutto obliterato l ’aff ioramento segnalato in romano et al. (1994) aprendone comunque altri ugualmente significativi. nella fig. 2 è riportata la situazione alla cava al 1994; dalla foto è possibile vedere con chiarezza che al di sotto dell’ dell’ic (d), sono presenti circa 10 m di piroclastiti sciolte pre-ic (b e c), poggianti a loro volta sul substrato carbonatico (a). i sopralluoghi successivi hanno permesso di descrivere nel dettaglio le formazioni vulcaniche pre ic; esse poggiano con angoli di circa 25° su brecce calcaree a matrice sabbiosa arrossata che ricoprono il substrato carbonatico. al contatto tra le brecce e le piroclastiti sovrastanti è presente un paleosuolo conservato in sacche. l’analisi delle caratteristiche litologiche, sedimentologiche e tessiturali delle piroclastiti ha permesso di distin281segnalazione di nuovi depositi piroclastici ... guere, dal basso, le seguenti unità (fig. 3): uunniittàà ppoommiicceeaa ddaa ccaadduuttaa: è costituita da una successione di circa 2 m di pomici. questa successione è distinta dal basso in: un livello di cenere fine ricca in cristalli sciolti con spessore di 8 cm; un livello di circa 40 cm di pomici da caduta grigio fig. 2 affioramento delle piroclastiti pre ignimbrite campana (da romano et al., 1994) nella cava abbandonata di maddaloni. a) calcari mesozoici e brecce di versante; b) unità pomicea pre ignimbrite campana; c) pomici rimaneggiate; d) ignimbrite campana. outcrop of pre campanian ignimbrite pyroclastic deposits (from romano et al., 1994) in the abandoned quarry near maddaloni. a) mesozoic limestones and slope breccia; b) pre campanian ignimbrite pumiceous unit; c) reworked pumiceous levels; d) campanian ignimbrite. fig. 3 colonna stratigrafica di sintesi dei terreni affioranti nella cava abbandonata di maddaloni. synthetic stratigraphic column of pre campanian ignimbrite pyroclastic deposits cropping out in the abandoned quarry near maddaloni. 282 avana con debole gradazione inversa (fig. 4); il diametro delle pomici a spigoli vivi è mediamente di circa 1,5 cm, con un massimo di 3 cm; alternanze di livelli pomicei e livelli cineritici (spessore 1,5 m) risedimentati lungo il versante a spese della sottostante unità pomicea da caduta. uunniittàà ddaa fflluussssoo (fig. 5): questa unità poggia con un chiaro contatto erosionale sulle pomici basali; è costituita da un deposito piroclastico a struttura massiva in cui la matrice pomicea e sabbiosa assume una colorazione giallastro – rossastra, al suo interno sono diffuse pomici grigie non alterate e subarrotondate di dimensioni variabili, mediamente centimetriche e spesso raggruppate in sciami. le caratteristiche tessiturali del deposito indicano un meccanismo di messa in posto da flusso piroclastico. il suo spessore è variabile (in questa località da 2 a 4m) e la parte sommitale è parzialmente pedogenizzata. l’unità da flusso è a sua volta ricoperta da circa 1,5 metri di depositi piroclastici da caduta alternati a livelli pomicei rimaneggiati che, nella parte alta, sono ricoperti da un deposito prevalentemente vulcanoclastico, con intercalazioni di lenti di clasti carbonatici decimetrici a spigoli vivi, pedogenizzato al tetto. iiggnniimmbbrriittee ccaammppaannaa: al tetto di questi deposti (fig. 2) si rinviene un tufo grigio a scorie grigie con fratturazione colonnare appartenente alla ben nota formazione vulcanica campana; lo spessore diminuisce dalla piana verso il versante passando da circa 15m a circa 50 cm. 33..22.. llooccaalliittàà ffoorrcchhiiaa --dduurraazzzzaannoo lungo la strada che da forchia conduce a durazzano è possibile notare in diversi punti di affioramento un deposito piroclastico, di circa 8m di spessore a tessitura massiva, compatto ma non litoide, costituito da una matrice a granulometria sabbiosa, sabbiosoghiaiosa, arrossata o giallastra e da inclusi pomicei di colore avana, sub-arrotondati presenti in maniera diffusa e spesso in lenti. queste caratteristiche permettono di definirlo come un flusso piroclastico pomiceo la cui messa in posto è stata guidata dalla morfologia preesistente. si rinviene nella porzione sud-occidentale della piana di durazzano e lungo la strada che da forchia sale alla sella di durazzano, localmente ricoperto da depositi colluviali al cui interno si rinvengono clasti calcarei grossolani, frammenti ceramici di età romana e scorie di scarto della lavorazione del ferro. un affioramento molto significativo è localizzato nella piana di durazzano. qui è chiara la sovrapposizione dei prodotti dell’ic sui prodotti del flusso pomiceo prima descritto (fig. 6). le due formazioni vulcaniche vengono a contatto bruscamente lungo una superficie di erosione e presentano caratteristiche litologiche molto diverse. il deposito tufaceo inferiore ha una colorazione giallo rossastra, è prevalentemente pomiceo e, pur essendo compatto, non presenta fenomeni di litificazione secondaria; il deposito tufaceo superiore (ic), invece, ha una tipica colorazione grigiastra è ricco in frammenti scoriacei e presenta un aspetto litoide; quest’ultima caratteristica è osservabile meglio negli affioramenti presenti più a valle nel paese di durazzano dove l’ic assume anche la tipica fratturazione colonnare. fig. 4 particolare dell’unità pomicea da caduta nella cava abbandonata di maddaloni. a) livelli di pomici da caduta in posto; b) alternanze di livelli di pomici rimaneggiate. detail of the fall pumiceous unit in the abandoned quarry near maddaloni. a) fall pumiceous unit; b) reworked pumiceous levels. fig. 5 cava abbandonata di maddaloni: l’unità da flusso (b) poggia con contatto erosionale sull’unità pomicea (a). abandoned quarry near maddaloni: erosional contact between flow unit (b) and fall pumiceous unit. f. bellucci, n. santangelo & a. santo 283 33..33 ppiiaannaa ddii dduurraazzzzaannoo:: llooccaalliittàà mmaasssseerriiaa mmeelllliinnoo in questa località la serie piroclastica è caratterizzata da depositi da caduta e da flusso in posto, inseriti in una successione di depositi piroclastici rimaneggiati prevalentemente pomicei, con granulometria da cineritico-sabbiosa a ghiaiosa, che definiscono una conoide alluvionale (fig. 7). la base di questa successione alluvionale non è affiorante e lo spessore minimo stimabile è di almeno 20 metri. gli affioramenti sono tutti localizzati all’interno di una cava dove è stato possibile riconoscere le seguenti unità piroclastiche in posto: uunniittàà ppoommiicceeaa ddaa ccaadduuttaa e’ costituita da 70 cm di pomici da caduta biancastre, a spigoli vivi, vacuolari, vetrose con dimensioni fino 5 cm di diametro; scarsa la presenza di litici, con diametro massimo di 2 cm. (a in fig. 8). queste pomici poggiano su un deposito massivo a matrice cineritica con pomici sub-arrotondate e litici più piccoli di quelli del deposito da caduta (0,5 cm); lo spessore è variabile (circa 15 cm), la giacitura è conforme alle pomici soprastanti ed ha un’inclinazione di circa 40°. alle pomici da caduta indisturbate, seguono verso l’alto, per circa 2m, alternanze di livelli cineritici e pomicei costituiti dai materiali del livello da caduta risedimentati in ambiente alluvionale. uunniittàà ddaa fflluussssoo questa unità si rinviene intercalata nei depositi di conoide con spessori e giacitura diverse in funzione delle geometrie dei depositi sottostanti e del grado di erosione subito dopo la sua messa in posto. in un piazzale più basso della cava (fig. 9) è possibile notare come tale unità si inserisce ai margini della conoide assumendo una giacitura suborizzontale con spessori a vista maggiori di 2 m; a tetto presenta altri 3 m di piroclastiti rimaneggiate in ambiente alluvionale. chiudono la successione stratigrafica dell’area un paio di metri di piroclastiti pedogenizzate brunastre. la base di questa unità è costituita da un livello pomiceo-cineritico, biancastro compatto con uno spessore di circa 15 cm; la tessitura è massiva la matrice è sabbiosa avana rosata e le pomici sono di colore grigio avana di dimensioni mediamente centimetriche. verso la parte alta del deposito sono presenti pomici di dimensioni maggiori (fino a 4,5 cm) vacuolari, a volte vetrose con fenocristalli chiari e scuri; è scarsa la presenza di litici tra i quali sono frequenti clasti di tufo marrone scuro con dimensioni di circa 1 cm. le caratteristiche tessiturali di questa unità sono quelle di un flusso piroclastico pomiceo. 33..44.. llooccaalliittàà ssoollooppaaccaa in aree più interne rispetto alla piana campana, precisamente nella zona di solopaca, sono stati rilevati altri limitati affioramenti di piroclastiti antiche non segnalate in fig. 8 località “masseria mellino” a durazzano: l’unità pomicea da caduta in posto (a) e rimaneggiata (a’) e l’unità da flusso (b) intercalate ai depositi piroclastici rimaneggiati in ambiente di conoide (c). masseria mellino locality, durazzano: fall pumiceous unit (a), reworked pumiceous unit (a’) and flow unit (b) interbedded within alluvial fan deposits. fig. 6 la sovrapposizione dell’ ignimbrite campana (b) sui prodotti dell’unità da flusso (a) nella piana di durazzano. the campanian ignimbrite (b) lying on the flow unit (a) near durazzano village. fig. 7 sezione geologica schematica dei depositi piroclastici pre ignimbrite campana affioranti nei dintorni di durazzano. 1) ghiaie e sabbie vulcanoclastiche di ambiente di conoide alluvionale; 2) ignimbrite campana; 3) unità da flusso; 4) unità pomicea da caduta; 5) calcari mesozoici; 6) faglia. geological cross section in the precampanian ignimbrite pyroclastic deposits cropping out near durazzano. 1) volcanoclastic gravel and sands of alluvial fan; 2)ic; 3) flow unit; 4) fall pumiceous unit; 5) mesozoic limestones; 6) fault. segnalazione di nuovi depositi piroclastici ... 284 letteratura. il più significativo è quello di località “ferri” in sinistra orografica del f. calore dove le piroclastici antiche poggiano su argille e sabbie di ambiente fluvio-palustre e sono caratterizzate da ripetute alternanze di livelli pomicei bianchi e grigi e di livelli cineritici, nell’insieme fortemente cementati e a consistenza tufacea (fig. 10). i livelli di pomici presentano gradazioni sia inverse che dirette, le pomici hanno dimensioni variabili dai 2 ai 5 mm, si presentano molto alterate e sovente contengono litici; lo spessore totale è di circa 2 m. al tetto di questi depositi si rinviene una successione di conglomerati di conoide alluvionale cui sono associate delle superfici terrazzate intorno ai 100 m s.l.m.; tali conglomerati vengono attr ibuit i in letteratura al tardo pleistocene medio (iacobacci et al., 1959). sia i conglomerati che le piroclastici antiche risultano ricoperte lateralmente dalla formazione dell’ic il cui top deposizionale costituisce una superficie terrazzata intorno ai 55 m s.l.m. (fig.11). 44.. ii lliivveellllii ppoosstt--iicc al tetto pedogenizzato dell’ic, o su sedimenti alluvionali che la ricoprono, abbiamo rinvenuto in tutta l’area investigata altri depositi piroclastici da caduta non distinti nella precedente cartografia geologica ufficiale del foglio 172 “caserta”. essi affiorano prevalentemente al top di superfici terrazzate (loc. limatola, dugenta) hanno uno spessore complessivo variabile dai 50 ai 200 cm e presentano quasi sempre nella parte bassa cineriti bianche e grigie, fittemente laminate, con intercalazioni di livelli pomicei bianchi. nella parte alta invece si rinviene costantemente un livello di cineriti giallastre, massive con pomici sparse aventi uno spessore di circa 60 cm (fig. 12). la base spesso poggia su un paleosuolo marrone che si sviluppa a tetto dell’ic o su depositi alluvionali e/o colluviali. tra gli affioramenti più significativi (fig.13), oltre a quello della cava “etep” nei pressi di dugenta, dove al tetto dell’ic si rinvengono delle alluvioni ghiaioso-sabbiose a stratificazione incrociata sormontate da un livello di pomici e poi di cineriti di colore giallastro, va segnalato quello di località “campitello” (ave grazia plena) dove è possibile osservare dal basso stratigrafico1,5 m di cineriti molto fini bianco-giallastre, cui seguono 80 cm di pomici (diametro 2÷3 mm) immerse in una matrice sabbiosa gialla con cristalli idiomorfi di mica e pirosseni. in località “bagno” in sinistra della valle del f. calore è possibile osservare piroclastici molto simili a quelle descritte precedentemente e caratterizzate da alternanze di ceneri e di livelli pomicei. esse sono intercalate a depositi ghiaiosi di ambiente di conoide alluvionale che poggiano chiaramente sulla formazione dell’ic. altri affioramenti significativi sono ubicati nelle numerose cave presenti nei dintorni di caserta, come alla cava di san marco evangelista (fig.14) dove è chiaramente visibile il paleosuolo interposto tra il top dell’ic e questi depositi da caduta riconoscibili anche da fig. 10 i depositi piroclastici pre ignimbrite campana di solopaca. a) argille fluvio-lacustri; b) paleosuolo; c) livelli di pomici grigio scure; d) livelli di pomici grigio chiare. the pre campanian ignimbrite piroclastic deposits cropping out near solopaca. a) fluvio-lacustrine clay; b) paleosoil; c) dark grey pumiceous levels; d) grey pumiceous levels. fig. 9 località “masseria mellino”: unità da flusso (a) ricoperta dai depositi di conoide alluvionale (b) e dal suolo attuale (c). masseria mellino locality, durazzano: the flow unit (a) covered by alluvial fan deposits (b) and present day soil. lontano per la colorazione biancastra e giallastra. la presenza costante in tutti gli affioramenti descritti delle cineriti bianche stratificate passanti ad un livello pomiceo massivo di colore giallastro, lo spessore complessivo poco variabile della successione piroclastica (circa 1÷2 m), la chiara posizione stratigrafica, sicuramente più recente dell’ic, la diffusione areale pressocchè continua tra caserta e solopaca (cfr. fig. 1) fanno ritenere che si tratti sempre dello stesso deposito piroclastico da caduta. f. bellucci, n. santangelo & a. santo queste due ultime unità sono state rinvenute nella medesima posizione stratigrafica e sicuramente sottoposte alla formazione dell’ic. l’unità da flusso in particolare sembra avere una notevole estensione areale e potrebbe includere il “tufo di durazzano” segnalato da rolandi et ali., (2003) e datato 116 ka. per quanto riguarda i depositi post-ic essi rappresentano i prodotti di uno stesso evento eruttivo che ha interessato tutta l’area compresa tra caserta, vallo di maddaloni, limatola, dugenta e solopaca. la parte basale di questi depositi, caratterizzata da alternanze di cineriti bianche e grigie fittemente laminate, presenta elevate analogie sedimentologiche con la parte basale del lower member del tufo giallo napoletano auct. individuato e descritto nei dintorni di caserta (s. angelo in formis) da cole & scarpati (1993) e da wolhetz et al., (1995). in particolare i livelli cineritici laminati potrebbero essere correlati con l ’unità lm1 di wohletz et al., 1995, mentre risulta più difficoltoso, in assenza di analisi granulometriche, definire una corrispondenza tra le cinerit i massive giallastre sovrastanti e gli altri 13 livelli segnalati dagli stessi autori nell’affioramento di s. angelo in formis. in alternativa tali depositi potrebbero essere correlati alle piroclastiti datate 23 ka che trovano corrispondenza con l’ignimbrite di giugliano (de vivo et al., 2001; rolandi et al., 2003) e con il livello di tephra y3 rinvenuto in carotaggio nel mar tirreno (munno & petrosino, in stampa). in ogni caso è importante segnalare che, in tutta l’area studiata, questi depositi sono gli unici presenti al di sopra dell’ic e che sembrano quindi mancare i prodotti di provenienza flegreovesuviana post-ic segnalati in aree immediatamente a sud est (valle del clanio) da di vito et al., (1998); ciò è ovviamente da imputare ad assi di dispersione differenti. i dati stratigrafici raccolti, oltre a fornire preziose informazioni sull’at285 fig. 11 sezione geologica illustrante i rapporti tra depositi alluvionali e depositi piroclastici nei dintorni di solopaca. 1) alluvioni recenti del f. calore (olocene); 2) ignimbrite campana (39 ka); 3) depositi di conoide alluvionale (pleistocene superiore olocene); 4) depositi fluviali terrazzati (pleistocene mediosuperiore); 5) depositi piroclastici antichi (pleistocene medio?); 6) brecce di versante (pleistocene inferiore-medio) ; 7) calcari mesozoici; 8) faglia. geological cross section showing the relationships between alluvial and pyroclastic deposits near solopaca. 1) recent alluvial deposits of te calore river (holocene; 2) campanian ignimbrite (39 ky); 3) alluvial fan deposits (upper pleistocene holocene); 4) terraced fluvial deposits (middle upper pleistocene); 5) ancient pyroclastic deposits middle pleistocene ?); 6) slope breccias (lower-middle pleistocene); 7) mesozoic limestones; 8) fault. fig.12 località: “ave gratia plena”: particolare dei depositi post ignimbrite campana. a) paleosuolo; b) depositi cineritici biancastri stratificati; c) livello pomiceo massivo di colore giallastro. "ave gratia plena" localit: detail of the post campanian ignimbrite pyroclastic deposits. a) paleosol; b) white layered ash deposits; c) massive and yellowish pumiceous level. 55.. pprroobblleemmii aappeerrttii ee ccoonncclluussiioonnii in tutte le località citate nel testo sono stati prelevati campioni sui quali sono in corso analisi mineralogico-petrografiche e sedimentologiche, per risalire alla paragenesi e quindi alla precisa posizione tefrostratigrafica di queste piroclastiti. pur non avendo ancora risultati sperimentali, sulla base dei soli dati stratigrafici è tuttavia possibile affermare che nell’area esaminata esistono almeno tre formazioni vulcaniche più antiche dell’ ic. esse sono rappresentate dalle pomici antiche di solopaca e dai due livelli denominati, al momento, “unità pomicea da caduta di maddaloni ” e “unità da flusso di durazzano” segnalazione di nuovi depositi piroclastici ... tività eruttiva tardo pleistocenica dell’ area della piana campana potranno, in futuro, contribuire a identificare nuovi livelli marker per la stratigrafia dei depositi continentali e marini tardo quaternari del margine tirrenico campano ed essere correlati ad alcuni dei numerosi livelli piroclastici che si rinvengono normalmente nelle stratigrafie di sondaggi profondi eseguiti in piana campana. llaavvoorrii cciittaattii alessio m., bella f., improta s., belluomini g., calderoni g., cortesi c. & turi f. (1973) university of rome carbon 14 dates x, radiocarbon, 1155 (1), 165. alessio m., bella f., improta s., belluomini g., cortesi c.& turi f. (1971) university of rome carbon 14 dates xii, radiocarbon, 1166 (3), 358-367. aprile f. & ortolani f. (1978) – nuovi dati sulla struttura profonda della piana campana – boll. soc. geol. it., 9977, 591-608. aprile f. & toccaceli r.m. (2002) – nuove conoscenze sulla stratigrafia e distribuzione dei depositi ignimbritici quaternari nel sottosuolo della piana del sarno (salerno campania) – italia meridionale. il quaternario, 1155 (2), 169-174. barberi f., innocenti f., liirer l., munno r., pescatore t., santacroce r. (1978) – the campanian ignimbrite: a major prehistoric eruption in the neapolitan area (italy) – bull. volcanol., 4411 (1), 122. barberi f., cassano e., la torre p., sbrana a. (1991) structural evolution of campi flegrei caldera in the light of volcanological and geophysical data. j.volcanol geotherm res. 4488, 33-49. brancaccio l., cinque a., romano p., rosskopf c., russo f., santangelo n. & santo a. (1991) – geomorphology and neotectonic evolution of a sector of the thyrrenian flank of the southern apennines (region of naples, italy) – z. geom., 8822, suppl. bd., 47-58. brancaccio l., cinque a., romano p., rosskopf c., 286 fig. 13 colonne stratigrafiche relative agli affioramenti più significativi di depositi piroclastici post ignimbrite campana. per le ubicazioni degli affioramenti vedi fig.1. stratigraphical columns for the most significant outcrops of post campanian ignimbrite pyiroclastic deposits. see fig. 1 for location. fig. 14 i depositi piroclastici post ignimbrite campana nella cava abbandonata di san marco evangelista”. a) ic; b) paleosuolo; c) cineriti bianche stratificate e livello pomiceo massivo giallastro; d) suolo attuale. post campanian ignimbrite piroclastic deposits cropping out in the abandoned quarry near san marco evangelista. a) campanian ignimbrite; b) paleosol; c) white layered ash deposits and massive yellowish pumiceous level; d) present day soil. f. bellucci, n. santangelo & a. santo russo f., santangelo n. (1994) l'evoluzione delle pianure costiere della campania: geomorfologia e neotettonica. mem. soc geogr. it., 5533, 313337. cole p.d. & scarpati c. (1993) a facies interpretation of the eruption and emplacement mechanism of the upper part of the neapolitan yellow tuff, campi flegrei, southern italy. bull. volcanol., 5555, 311-326. d’erasmo g., (1931) – studio geologico dei pozzi profondi della campania. boll. soc. natur. in napoli, 4433 , 15-143. de vivo b., rolandi g., gans p. b., calvert a., bohrson w. a., spera f. j. & belkin h. e. (2001) new constraints on the pyroclastic eruptive history of campanian volcanic plain (italy). mineralogy and petrology 7733, 47-65. deino al., southon i., terrasi f., campajola l. and orsi g. (1994) 14 v and 40ar/39ar dating of the campanian ignimbrite, phlegrean fields, italy. abstract icog, berkeley, ca, u.s.a. di girolamo p. (1968) petrografia dei tufi campani: il processo di pipernizzazione (tufo-tufo pipernoide-piperno). rend. acc. sc. fis. mat. napoli s. 4, 35, 1-70. di girolamo p., rolandi g., stanzione e d. (1973) l’eruzione di pomici a letto dell ’ ignimbrite campana. period. min., 4422,, 436-468. di girolamo p. (1978) geotettonic setting of miocene – quaternary volcanism in and around the eastern tyrrhenian sea border (italy) as deduced from major element geochemistry. bull.volcanol. 4411, 421-432 di girolamo p., ghiara m.r., lirer l., munno r., rolandi g., & stanzione d. (1984) vulcanologia e petrografia dei campi flegrei. boll. soc. geol. it., 110033, 349-413. di vito m., sulpizio r., zanchetta g. (1998) i depositi ghiaiosi della valle dei torrenti clanio-acqualonga (campania centro-orientale): significato stratigrafico e paleoambientale. il quat., 1111 (2), 273-286. fisher r., orsi g., ort m., heiken g.(1993) mobility of a large-volume pyroclastic flow -emplacement of the campaninan ignimbrite, italy. j. volcanol. geotherm. res. 5566,, 205-220. iacobacci a., martelli g., perno u. (1959) osservazioni geologiche sul foglio 173 benevento. boll. serv. geol. it., 8800 (1), 73-75. ippolito f., ortolani f., russo m. (1973) struttura marginale tirrenica dell’appennino campano: reinterpretazione di dati di antiche ricerche di idrocarburi. mem. soc. geol. it., 1122, 227-250. munno r. & petrosino p. (in stampa) new constrains on the occurrence of y-3 upper pleistocene tephra marker layer in the tyrrhenian sea. i l quaternario. orsi g., civetta l., valentine g.a. (1999) volcanism in the campi flegrei. j. volcanol. geotherm. res. 9911, 470. ort m.h., rosi m., andersonn c.d. (1999) corelation of deposits and vent locations of the proximal campanian ignimbrite deposits, campi flegrei, italy, based on natural remanent magnetization and anisotropy of magnetic susceptibility characteristics. j.volcanol. geotherm. res. 9911,167-178. rolandi g., bellucci f., heizler m. t., belkin h. e. & de vivo b. (2003) tectonic controls on the genesis of ignimbrites from the campanian volcanic zone, southern italy. mineralogy and petrology, ss..ii.., 129. romano p., santo a. & voltaggio m. (1994) l’evoluzione geomorfologica della pianura del f. volturno (campania) durante il tardo quaternario (pleistocene medio-superiore-olocene. il quat., 77 (1), 41-56. rosi m. & sbrana a. (1987) the phlegraean fields. cnr quaderni di la ricerca scientifica, 111144, 175 pp. scandone r., bellucci f., lirer l., rolandi g. (1991) the structure of the campanian plain and the activity of the neapolitan volcanoes (italy). j. volcanol. geothrm. res., 4488, 1-31. wohletz k., orsi g., de vita s. (1995) – eruptive mechanism of the neapolitan yellow tuff interpreted from stratigraphic, chemical and granulometric data. j. vol. geoth. res., 6677, 263-290. 287 ms. ricevuto il 16 giugno 2003 testo definitivo ricevuto il 18 novembre 2003 ms. received: june 16, 2003 final text received: november 18, 2003 segnalazione di nuovi depositi piroclastici ... imp.capezzuoli_sandrelli neotectonic evidence in the quaternary continental carbonates from southern valdelsa basin (tuscany) enrico capezzuoli1 & fabio sandrelli1 1dipartimento di scienze della terra, via laterina 8, 53100, siena. e.mail: capezzuoli@unisi.it; sandrelli@unisi.it abstract: e. capezzuoli et al., neotectonic evidence in the quaternary continental carbonates from southern valdelsa basin (tuscany). (it issn 0394-3356, 2006). recognition of tectonic structures in quaternary sediments is usually very difficult, mainly in detrital and uncemented deposits. on the contrary, quaternary continental carbonates represent an important exception that have the quality of being potential indicators of neotectonics significance. facies analyses of some quaternary calcareous tufa succession in the valdelsa basin (southern tuscany) point out a neotectonics activity that have interested these deposits during the middle pleistocene-holocene. recognition of neotectonics activity is mainly based on identification of “anomalous” bedding of these recent deposits, in contrast with the original setting of their depositional environment. this evidence imply two tectonic phases in southern valdelsa during the middle-late pleistocene and the late pleistocene-holocene. all this evidence will be useful for a better comprehension of the evolution of this northern apennine sector during the quaternary. riassunto: e. capezzuoli et al., evidenze di neotettonica nei carbonati continentali quaternari della valdelsa (toscana). (it issn 0394-3356, 2006). osservazioni di campagna ed analisi di facies condotte sui depositi carbonatici continentali quaternari della valdelsa meridionale (provincia di siena), hanno permesso il riconoscimento di evidenze di attività neotettonica. questi sedimenti sono riconducibili a sei sintemi: sintema di campiglia dei foci – cdf, sintema dell’abbadia – abb, sintema di calcinaia – cal, sintema del torrente foci – foc, sintema di bellavista – bel, sintema di poggibonsi – pog. il sintema di campiglia dei foci, composto da quattro litofacies (litofacies argillosa, litofacies sabbiosa, litofacies conglomeratica, litofacies calcarea), è stato interpretato come l’espressione di un episodio palustre/lacustre datato al pleistocene inferiore-medio sulla base di una fauna a mammiferi rinvenuta nella litofacies argillosa. i sintemi dell’abbadia, di calcinaia, del torrente foci e di bellavista sono riferiti ad una successione di terrazzi tutti caratterizzati da due litofacies (calcareous tufa e sedimenti detritici) in proporzioni variabili nei vari sintemi e riferiti ad episodi di sedimentazione fluvio-palustre datati al pleistocene superiore-olocene sulla base di una datazione radiometrica effettuata nel cal (25690±180 b.p.). il sintema di poggibonsi corrisponde alle alluvioni attuali ed è formato da sedimenti detritici e localmente da sedimenti calcarei tuttora in formazione. analisi di facies effettuate sui depositi calcarei hanno permesso di individuare evidenze di attività tettonica quaternaria: podere le frigge: nelle vicinanze di monteriggioni affiora una successione di calcareous tufa di cal che si caratterizza per l’inclinazione degli strati, misurata in circa 15° in direzione ne. l’analisi sedimentologica ha evidenziato che l’intera successione è l’espressione di una sedimentazione in acque a scarsa energia o stagnante, confrontabile con un ambiente di tipo palustre. l’attuale giacitura dei depositi risulta contrastante con il setting deposizionale originale e riconducibile ad un basculamento degli strati legato ad una faglia diretta situata in corrispondenza dell’adiacente fosso con andamento rettilineo e direzione nw-se. podere santa giulia: il rilievo su cui sorge tale podere, a sud di gracciano val d’elsa, è posto fra il corso del fiume elsa a sw ed una area pianeggiante a ne. questo rilievo è caratterizzato dalla presenza di depositi terrazzati carbonatici dei sintemi abb, cal, foc e terrigeni (in questa località) del bel. tutti i sintemi carbonatici si caratterizzano per un setting giaciturale immergente verso ne, ma con differenti inclinazioni a seconda del sintema di appartenenza. infatti il più recente dei tre (sintema foc) mostra inclinazioni di circa 15°÷20°, quello intermedio (sintema cal) di circa 20°÷25°, mentre quello più antico (sintema abb) presenta inclinazioni ancora maggiori, con massimi fino a circa 40°. nel sintema terrigeno bel non è stato possibile apprezzare l’esistenza di una eventuale deformazione. l’analisi di facies dei calcareous tufa, rappresentati da livelli fitoermali/fitoclastici, micritici ed argillosi (talvolta con materia organica), permette di ipotizzare un ambiente deposizionale prevalentemente di tipo palustre. l’attuale inclinazione della stratificazione è da mettere in relazione all’attività di una faglia diretta con direzione nw-se localizzata a circa 200 m nell’area pianeggiante a ne, attualmente coperta dai depositi più recenti e che ha agito in maniera sinsedimentaria alla deposizione dei diversi sintemi. area del diborrato: tale zona si colloca lungo il corso del fiume elsa fra gracciano a s e colle val d’elsa a n. lungo tale settore vallivo, qui profondamente scavato, affiorano i depositi calcarei del cdf con inclinazioni dell’ordine di circa 15°, che nelle aree circostanti sono sospesi sul fondovalle di circa 40 metri e presentano giacitura suborizzontale. nel fondovalle questi calcari sono ricoperti dai depositi più recenti del cal. la faglia diretta responsabile del basculamento dei depositi, disposta circa nnw-sse, non disloca i sintemi più recenti e trova il suo probabile proseguimento con una sezione rettilinea del corso del fiume elsa. area di montemorli-san lucchese: nel settore ad w di poggibonsi, i depositi del cdf sono disposti su quattro quote diverse: quelli a quota più elevata sono quasi completamente smantellati dall’erosione. le diverse quote sono intervallate da salti morfologici rettilinei di circa 10 metri, paralleli fra loro e con direzione nw-se. evidenze morfolofgiche, ripetizione delle litofacies ed il parallelismo dei gradini permettono di associare questa struttura ad una gradinata di faglie dirette. le stesse strutture non interessano i depositi dei sintemi più recenti. sulla base delle ricerche condotte, viene evidenziato come la valdelsa meridionale sia stata interessata durante il quaternario da almeno due eventi tettonici: una prima fase durante il pleistocene medio-pleistocene superiore (post-deposizione del sintema cdf e precedente alla deposizione dei sintemi fluvio-palustri) e una più recente riferibile al pleistocene superiore-olocene (sin-deposizionale ai sintemi fluvio-palustri). keywords: calcareous tufa, lacustrine limestone, neotectonics, valdelsa, southern tuscany. parole chiave: calcareous tufa, calcare lacustre, neotettonica, valdelsa, toscana meridionale. il quaternario italian journal of quaternary sciences 19(1), 2006 155-166 156 e. capezzuoli & f. sandrelli 1. introduction recognition of tectonic structures in quaternary sediments is usually very difficult. in fact these deposits, generally detrital and unlithified, are rapidly eroded and reworked by weathering, pedogenic processes and landslides. natural evolution of morphology quickly cover or transform the fault scarp, so that the identification of faulted surface is generally confused. compared to the quaternary detrital sediments, continental carbonates represent an important exception. in fact they are lithified and hence where they are preserved, they are generally young and thus potentially of neotectonic significance (hancock et alii, 1999). this potential was already recognized by barnes et alii (1978) in particular for the calcareous continental sediments deposited by thermal springs (travertines – ford & pedley, 1996; capezzuoli & gandin, 2004). however, it can also be applied to lacustrine limestone and continental carbonates deposited by karstic waters in fluvialpaludal environments (calcareous tufa ford & pedley, 1996; capezzuoli & gandin, 2004). in fact alteration and weathering processes are slowed by the lithification and evidence of tectonic influence is preserved. facies analyses of these deposits and recognition of their original depositional environment result important, particularly in comparison with the actual setting of these deposits. identification of “anomalous” bedding of these recent deposits can be interpreted as the result of a tectonic influence. here are shown some evidence of neotectonic activity deduced by the quaternary continental carbonates in the valdelsa basin (southern tuscany). 2. pre-quaternary geological setting of the valdelsa basin the valdelsa basin is a segment of a nw-se oriented, tectonic depression extending for over 300 km from the serchio valley to the n, to the upper tiber valley to the s (fig.1). its northern limit is placed in the area of empoli where the basin is about 25 km wide, while in the southern portion, between poggibonsi and monteriggioni, its width quickly reduces to only 15 km. the limit between these two portions coincides with one of the most important transversal tectonic lines of the northern apennines (piombino-faenza line; costantini et al., 1980). the valdelsa basin is an extensional structure developed in late miocene and it is bordered to the w and the s by the middle-tuscan ridge and by the chianti ridge to the e (bossio et al., 1995b). the former is mainly represented by formations of the tuscan domain, comprising triassic metaquartzarenites, metaconglomerates and phyllites and the “calcare cavernoso” tectonic carbonatic breccia derived from late triassic anhydrites. in the chianti ridge the substratum is mainly composed of flysch successions of sandstones, limestone, marly-limestones and shales of the upper cretaceous eocene, by middlelate giurassic ophiolites and by lower cretaceous shales with grey flinty limestones all referred to tectonic units of the ligurian domain. the neogene sedimentation (bossio et al., 2000) is characterized by a first marine cycle referred to the late serravallian and composed of grey-green sandstone intensely bioturbated. in the late tortonian the area was covered by a lacustrine environment, with the deposition of thick, clast-supported conglomerates with cross-stratification and consisting of clasts from the ligurian domain and heteropic with grey clays and marly clays intercalated with layers and levels of grey sandstones. in the late messinian these formations were covered in disconformity by grey silty-marly clays with lenses of lignite and referred to the “lac-mer” depositional setting. in the marginal areas of this environment, thick coarse clastic deposits referable to alluvial fan-tofluvial environment were present with different composition in the different areas of the basin. in the early pliocene the area was covered by the sea with the deposition of thick, fossiliferous, grey-blue clays and silty clays, that locally are concordant on the late messinian clays (area of borro la strolla valley, se of poggibonsi; bossio et al., 1993). in this area, these early pliocene clays are overlain by conglomerates and clays referable to a ruscinian continental environment. in general the clays and sands widely exposed in the valdelsa represent a second marine sedimentary cycle referable to the middle pliocene. these middle-fine grained yellow sands, locally cemented, show lateral relationships with the massive grey clays. in the eastern outcrops of the basin, these sands are heteropic and overlaid by clast-supported conglomerates, formed by sub-rounded, locally embricated elements from the ligurian domain, and referred to marine-to-continental environment (benvenuti & degli’innocenti, 2001). in the upper middle-pliocene, the valdelsa basin, as the greatest part in southern tuscany, is characterized by a general marine regression that led to the emersion of the area (bossio et al., 1995a). 3. the pleistocene-holocene synthems during the early-middle pleistocene, an area of over 52 km2 of the southern sector of the basin (among poggibonsi to n, monteriggioni-gracciano d’elsa to s, san gimignano to w and staggia senese to e; fig.2) was characterized by a continental episode (campiglia dei foci synthem cdf; capezzuoli & sandrelli, 2004). this synthem consists of prevalently carbonate deposits mainly located in two subhorizontal plateaux (campiglia dei foci and the area between colle val d’elsa and staggia) and in other smaller ones distributed between 240 and 230 m a.s.l. these deposits usually lie on pliocene sands or directly on the preneogene substratum; the types of basal contact are respectively disconformity and angular unconformity, while intensely rubefied soils overlay the deposits (costantini & carnicelli, 1986). in some areas, subhorizontal relict surfaces related to the base of the succession can be observed at the summit of the pliocene highs. this synthem presents a variable thickness (maximum about 30 m) and it is characterized by four heteropic lithofacies (clayey, sandy, conglomerate and calcareous; fig.3) present in different proportions in the various areas. in the clayey lithofacies near san gimignano, several lignite lenticular bodies yielded a 157neotectonics evidence in the quaternary ... figure 1 generalized structural map and localization of the studied area: a – major structures of italy, with geologic and geomorphic subdivision of the apennines. b neogene-quaternary basins of the northern apennines (basins: bc. baccinello, e. elsa, fu. fucino, mu. mugello, ra. radicofani, rd. radicondoli, ri. rieti, si. siena, su. sulmona, vt. volterra, te. tiberino; transverse lineaments: oa. olevano-antrodoco, gp. grosseto-pienza, ls. livorno-sillaro, pf. piombino-faenza, sv. sestri-voltaggio; mtr – middle tuscan ridge; ptr – perithyrrenian ridge;m 3.5 – radiometric age of igneous rocks in ma)(modified from sagri et al., 2004). carta strutturale schematica e localizzazione dell’area: a. principali strutture italiane e suddivisioni geomorfiche dell’appennino: b. bacini neogenici-quaternari dell’appennino settentrionale (bacini: bc. baccinello, e. elsa, fu. fucino, mu. mugello, ra. radicofani, rd. radicondoli, ri. rieti, si. siena, su. sulmona, vt. volterra, te. tiberino; lineamenti trasversali: oa. olevano-antrodoco, gp. grosseto-pienza, ls. livorno-sillaro, pf. piombino-faenza, sv. sestri-voltaggio; mtr – dorsle medio toscana; ptr – dorsale peritirrenica;m 3.5 – età radiometrica delle rocce ignee in ma) (modificato da sagri et al., 2004). 158 fi gu re 2 g eo lo gi ca l s ch em e of t he s ou th er n v al d el sa b as in . th e lit ho fa ci es o f th e c d f s yn th em a nd t he d ep os its o f th e a b b , c a l, f o c , b e l s yn th em s ar e no t se p ar at el y vi si b le a t th is sc al e. s ch em a ge ol og ic o d el s et to re m er id io na le d el la v al d el sa . l e lit of ac ie s d el s in te m a c d f e i d ep os iti d ei s in te m i a b b , c a l, fo c e b e l, a q ue st a sc al a, n on s on o ev id en zi ab ili s in go la rm en te . e. capezzuoli & f. sandrelli 159 mammalian and molluscan fossil fauna attributed to the early-middle pleistocene (berzi, 1972) and recently ascribed to the ponte galeria faunal unit (petronio & sardella, 1999; raia et al., 2005). the relationships among the various lithofacies show a vertical and lateral evolution from a palustrine environment with mainly detrital sedimentation (clayey lithofacies), to a lacustrine environment characterized by the sedimentation of calcareous muds (calcareous lithofacies) in the central areas of the basin and the deposition of coarser materials in the marginal areas, especially near the mouths of small tributaries (sandy and conglomerate lithofacies). the change from clayey to calcareous sedimentation has been attributed to the input of large amounts of water with a high caco3 concentration, probably coming from the southern sectors of the basin (monteriggioni area, capezzuoli & sandrelli, 2004). the carbonate deposition, related to saturation of the water by progressive concentration and evaporation, was probably favoured by the endorheic setting of the basin (capezzuoli & sandrelli, 2004) and occurred in arid climatic conditions, as documented by the presence of the gastropod parmacella and pseudotachea in the clayey lithofacies (manganelli & giusti, 1993; manganelli et al., 2005). the end of the lacustrine sedimentation was followed by a new hydrographic pattern which, as a consequence of the general uplifting of the area, cut the calcareous lithofacies and locally also the underlying pliocene sands. this caused selective erosion and produced an inverted relief in this area (bartolini & peccerillo, 2002). this new fluvial network controlled the sedimentation of the four fluvial-palustrine synthems (abbadia synthem abb, calcinaia synthem cal, torrente foci synthem – foc; bellavista synthem bel), which correspond to a succession of terraces on the slopes of the main river valleys of the area (fig.3). they consist mainly of detrital deposits (sands, silts and pebbles), associated in some valley areas with calcareous lithofacies. all synthems are characterized by erosive basal contacts (disconformity) and by an upper aggradational subhorizontal surface on which rubefied or brown soils developed. the usually poorly stratified calcareous lithofacies includes a dominant phytoclastic and phytohermal concretionary limestone due to the incrustation of plants (rushes, bryophytes and grass stems) associated with calcretes, calcareous sands and occasionally micritic limestones and/or peat shales, arranged in levels and lenticular bodies of variable thickness. these facies are characteristic of calcareous tufas, particularly those referable to the “paludal model” or “fluviatile model” sensu pedley (1990) and pedley et al. (2003). the extension of these carbonates is not constant in the various synthems, progressively decreasing from the oldest (abb) to the youngest (bel). the detrital deposits are usually represented by irregular fining-upward sequences composed of clastic calcareous sands associated with quartz-sands, silt, and gravel lenses. the calcareous sands derive from the erosional break-up of the carbonate lithofacies, while the quartz sand derives from the surrounding pliocene marine sands. the gravel layers, occurring mainly in the basal part of the synthems, represent the infilling of erosional pockets. they are composed of well rounded, poorly sorted (max 20 cm), locally imbricated polygenic clasts and a variable sandy matrix. merla & bortolotti (1967) referred these deposits to the holocene, but recent c14 radiometric dating of the organic clayey level of the cal synthem yielded an age of 25.690±180 years b.p. (capezzuoli & sandrelli, 2004), i.e. the late pleistocene. the origin of the fluvial network and the control of the fluvial-palustrine sedimentation were probably due to the tectonic activity and to climatic variations. the figure 3 schematic reconstruction of the stratigraphic units used for the quaternary deposits of the southern valdelsa (not in scale). cl calcareous lithofacies; a clayey lithofacies; s sandy lithofacies; cg gravelly lithofacies (from capezzuoli & sandrelli, 2004, slightly modified). ricostruzione schematica delle suddivisoni stratigrafiche adottate per lo studio dei depositi quaternari del settore meridionale della valdelsa (non in scala). cl litofacies calcarea; a litofacies argillosa; s litofacies sabbiosa; cg litofacies conglomeratica (da capezzuoli & sandrelli, 2004, modificato). neotectonics evidence in the quaternary ... 160 tectonic activity led to the progressive cutting of river valleys and to the circulation and/or rising of carbonate waters through faults. variations of the base level, with a consequent increase of fluvial incision in the cold and aggradation phases and precipitation of carbonates mainly in the warm and humid phases, can be related to climatic oscillations. precipitation of the calcareous tufas occurred only in the fluvial tracts with inputs of carbonate water, at least partly derived from hydrothermal rising. the progressive decrease of the volume of carbonate sediments can be correlated to a local decrease of tectonic activity, and the following occlusion of the upward paths of carbonate water, and/or to climatic or anthropic causes, as hypothesized in other european areas (goudie et al., 1993; dramis et al., 1999). the poggibonsi synthem corresponds to holocene as well as present alluvial deposits, sometimes well developed in the valley floors of several rivers in the area. these deposits consist essentially of sands and sandy silts with associated pebbles or gravel lenses. calcareous tufas are currently forming only in localized areas. 4. neotectonics evidence as hypothesized by capezzuoli & sandrelli (2004), origin and development of these synthems was strictly related to tectonic activity in the area, even if evidence of this activity has not previously been recognized. now facies analyses and field observations in specific outcrops demonstrate the presence of neotectonic activity that modified the original depositional setting of the local quaternary successions 4.1. podere le frigge: in this locality, w of monteriggioni, about a 4 m thick succession of calcareous tufa referred to the foc synthem is outcropping. this succession consists of alternating layers of phytohermal framestone (grass and moss cushions), intraclast tufa, oncoids, porous and dense micrite tufa with different thickness. this type of association is typical of low-energy/stagnant water and referable to a paludal environment (pedley, 1990). all the succession results inclined to about 15° towards ne (fig. 4). this inclination is in contrast with the depositional setting of the sequence, probably depositing with only some degrees maximum or on local low-angle paleosurfaces. consequently, the succession has been tilted by tectonics probably caused by a fault oriented about n 140e, located in the adjacent fosso dei pratini torrent and corresponding to a nw-se long lineament observed by aerial photos. 4.2. ponte santa giulia: the small ridge of podere santa giulia, settled s of gracciano val d’elsa, is located between the elsa river to se and a wide, nw-se oriented plain area to ne (pian senese plain) (fig. 5). along its flanks, the ridge is covered by the terraced calcareous deposits of the abb, foc, cal synthems and detrital deposits of the bel synthem. figure 4 geological scheme of podere le frigge area. a – view of the inclined calcareous tufa succession at podere le frigge. schema geologico dell’area di podere le frigge. a – immagine della successione inclinata di calcareous tufa presso podere le frigge. e. capezzuoli & f. sandrelli facies analyses of the calcareous tufa recognized the dominating presence of layers of phytoclast tufa, phytohermal framestones, peloidal tufa and micrite tufa. each layer exhibits evidence for both lateral and vertical accretion, and many are amalgamated laterally, producing a nodular appearance in outcrop. secondly, thin clayey and sapropelithc level are present. all these characteristics are consistent of poorly drained depressions or valleys, colonized by hydrophytic macrophytes and bryophyte hummocks (paludal tufas; pedley, 1990). the calcareous terraces are characterized by an evident bedding attitude towards ne with different inclina161 figure 5 geological scheme of ponte santa giulia area. a – view of the inclined calcareous tufa succession of foc synthem at ponte santa giulia. schema geologico dell’area circostante il ponte di santa giulia. a – immagine della successione inclinata di calcareous tufa del sintema foc presso podere le frigge. neotectonics evidence in the quaternary ... tions. the lower calcareous synthem (foc) is characterized by about 10°÷20° degrees, the rising above synthem (cal) is about 20°÷25°, while the uppermost (abb) presents an inclination up to about 40°. it is impossible to appreciate inclination in the younger terrace (bel) for the detrital composition of the deposits and the absence of natural outcropping. this inclined setting of the terraces, evidently in contrast with the original environment, is related with a neotectonics activity that tilted the terraces. this activity is related with a fault probably located under the alluvial deposits in the ne flat area of pian senese and oriented about n 135e. this fault is probably responsible of a deep sulphate water intrusion into the aquifer complex recognized in this same area by barazzuoli et al . (2002). different inclinations observed for each synthem is probably connected with syn-sedimentary movements of this fault. landslide movements are apparently neglected for absence of field and photo-aerial indicators. 4.3. diborrato: this is the name of a narrow gorge along the elsa river, between colle val d’elsa and gracciano val d’elsa. this gorge is mainly excavated in the late pleistocene-holocene calcareous tufa deposits of cal synthem, but in its southern part lacustrine limestones referable to the lower-middle pleistocene cdf synthem and partially covered by the cal deposits are present (fig. 6). all around this area, the same cdf deposits lies sub-horizontally on top of the hil ls, about 50 m higher of the gorge. this displacement is related with a roughly n 175w fault, actually buried by the late pleistocene-holocene deposits, probably located along a straight segment of the elsa river and partially corresponding with the diborrato gorge. this fault originally displaced the cdf synthem, exposing the less cemented pliocene sands that were easily dug by the fluvial erosion of the palaeo-elsa river (fig. 7). during the late pleistocene this valley was filled by the cal synthem that covered the fault scarp and partial ly the displaced cdf deposits. subsequent fluvial incisions and deposition create the gorge and the recent terraces. 4.4. montemorli-san lucchese area: in this locality, situated w of poggibonsi, the calcareous cdf deposits rest unconformably on the massive pliocene marine sands. the local quaternary succession consist 162 figure 6 geological scheme of diborrato area near colle val d’elsa. a – line drawing of the relations between cdf and cal synthems in the diborrato gorge. schema geologico dell’area del diborrato vicino colle val d’elsa. a – visione delle relazioni fra i sintemi cal e cdf nel diborrato. e. capezzuoli & f. sandrelli of fluvial gravel and sands up to 3 m thick, covered by carbonate sequences consisting of massive, grey-topink micritic limestone, microlaminated grey marl and undulose-bedded layers of phytohermal framestones. the sequence is interpreted as a low-energy, low-gradient “ramp” margin in a lacustrine basin, similar to that described by platt & wright (1991). in the montemorli-san lucchese area, this sequence results reiterated (fig. 8), distributed in four different altitudes separated by parallel scarps with limited height. some scarps, located on different sides of the elsa river, result aligned. this feature can be inferred by the presence of a set of three minor conjugate normal faults, oriented about n 130e and with moderate displacement (i.e., in the order of 10 m or less). the faults are associated to evident steps in the topography, which are of the same order of magnitude of the fault displacement. calcareous tufa deposits of the late pleistocene-holocene synthem present along the fault trace in the elsa valley below, do not present evidence of displacement. the outcrop conditions prevent direct observation of the fault plane. absence of similar reiterated portion of the cdf synthem in the other part of the area, parallelism of the morphological scarps and similarity of litofacies in the different sequences prevent the possibil ity of different entrenched terraces. 163 figure 7 evolutional reconstruction of the diborrato area (a – early-middle pleistocene; b,c – middle-late pleistocene; d – late pleistocene-holocene; e – today). ricostruzione dell’evoluzione dell’area del diborrato. (a – pleistocene inferiore-medio; b,c –pleistocene medio-superiore; d –pleistocene superiore-olocene; e – oggi). neotectonics evidence in the quaternary ... 164 figure 8 geological scheme of montemorli-san lucchese area. a – view of the san lucchese area from montemorli and line drawing of the cdf synthem outcrops. b view of the montemorli area from san lucchese and line drawing of the cdf synthem outcrops schema geologico dell’area di montemorli-san lucchese. a – panorama dell’area di san lucchese da montemorli e disposizione dei depositi del sintema cdf. b – panorama dell’area di montemorli da san lucchese e disposizione dei depositi del sintema cdf. e. capezzuoli & f. sandrelli according to santangelo (2003), the presence of multiplied terraces represent one of the best geomorphic signs of recent tectonic activity in fluvial environment. 5. evidence of neotectonics in valdelsa southern tuscany is affected by extensional tectonics from early-middle miocene (carmignani et al., 1994). since the middle pliocene, extension was accompanied by a widespread, mainly intrusive magmatism that produced a rapid regional uplift (dallmeyer & liotta, 1998). the tectonic evolution of the pliocene–quaternary basins in southern tuscany is mostly controlled by these two factors and related the coeval activity of nw-se normal faults (brogi et al., 2005 cum bibl.). an early middle pleistocene tectonic event was remarked by bernini et al. (1990), as revealed by the unconformities of fluvial over lacustrine deposits in various tuscan basins, while an important uplift phase was recognized during the middle and late pleistocene by bartolini & pranzini (1981) by the rearrangement of the arno basin drainage. this uplift is very important, because it is recognized to have transformed an area of rather low relief into becoming the northern apennine mountain chain (bartolini, 2003). during the late pleistocene-holocene extensional events are recognized in some basin (upper valdarno, mugello) (boccaletti et al., 1999). field evidence of all these tectonic phases are generally very difficult to recognize, mainly in detrital alluvial deposits. on the contrary, the continental carbonates, compared with the most superficial rocks, are cemented and where they are preserved, they are upstanding features. this is the case of the quaternary carbonate deposits present in the valdelsa basin, that show evidence of tectonic activity. orientation of the recognized valdelsa quaternary faults are consistent with the main apennine direction of surrounding structures. faults documented in the diborrato gorge and in the montemorli-san lucchese area testify to a tectonic phase started after the deposition of the cdf synthem (early-middle pleistocene) and ended before the deposition of the fluvio-palustrine synthems (upper late pleistocene-holocene). this phase can be related to the middle-late pleistocene tectonic phase recognized in different tuscan basins by different authors (bartolini & pranzini, 1981; bartolini, 2003). during the late pleistocene-holocene, coeval with the deposition of the fluvio-palustrine synthems, another tectonic phase is attested by faults of podere le frigge and ponte santa giulia. this phase is coheval with the extensional activity recognized in the upper valdarno and mugello basins by boccaletti et al., (1999). precise dating of the valdelsa fluvio-palustrine synthems will constrain the neotectonics evolution of this latter phase. all this evidence will be useful for a better comprehension of the evolution of this northern apennine sector during the quaternary. acknowledgments the authors wish to thank p. messina and an anonymous reviewer for their critical reading of the manuscript. references barazzuoli p., mocenni b., rigati r. & salleolini m. (2002) studio idrogeologico dei rapporti tra acque superficiali e profonde nella zona di gracciano dell’elsa (prov. di siena). quaderni di geologia applicata, 9(2), 79-95. barnes i., irwin w.p. & white d.e. (1978) global distribution of carbon-dioxide discharges and major zones of seismicity. united states geological survey, water resources investigations, 38-39, open file report. bartolini c. (2003) when did the northern apennine become a mountain chain? quaternary international, 101-102, 75-80. bartolini c. & peccerillo a. (2002) i fattori geologici delle forme del rilievo. lezioni di geomorfologia strutturale. pitagora editrice, bologna, 216 pp. bartolini c. & pranzini g. (1981) plio-quaternary evolution of the arno basin drainage, z. geomorph. n.f., 40, 77-91. benvenuti m. & degl’innocenti d. (2001) the pliocene deposits in the central-eastern valdelsa basin (florence, italy) revised through facies analysis and uncoformity-bounded stratigraphic units. rivista italiana di paleontologia e stratigrafia, 107 (2), 265-286. bernini m., boccaletti m., moratti g., papani g., sani f. & torelli l. (1990) episodi compressivi neogenico-quaternari nell’area estensionale tirrenica nord-orientale. dati in mare ed a terra. memorie della società geologica italiana, 45, 577-589. berzi a. (1972) an early middle pleistocene fauna at monte oliveto (s. gimignano, siena, italy). paleont. it. , 68, 29-33. boccaletti m., bonini m., moratti g. & sani f. (1999) compressive neogene-quaternary tectonics in the hinterland area of the northern apennines. journal of petroleum geology, 22(4), 37-60. bossio a., costantini a., foresi l.m., lazzarotto a., mazzanti r., liotta d., mazzei r., salvatorini g. & sandrelli f. (1995a) studi preliminari sul sollevamento della toscana meridionale dopo il pliocene middle. studi geol. camerti, volume speciale, 1995/1, 87-91. bossio a., foresi l.m., mazzei r., salvatorini g. & sandrelli f. (1995b) evoluzione tettonico-sedimentaria neogenica lungo una trasversale ai bacini di volterra e della val d’elsa. studi geol. camerti, volume speciale, 1995/1, 93-104. bossio a., mazzei r., salvatorini g. & sandrelli f. (1993) nuovi dati sui depositi mio-pliocenici del settore meridionale del bacino del fiume elsa. paleopelagos, 3, 97-108. bossio a., mazzei r., salvatorini g. & sandrelli f. (2000) geologia dell’area compresa tra siena, poggibonsi e castellina in chianti (prov. di siena). atti soc. tosc. sc. nat. mem. serie a, 107, 69-85. 165neotectonics evidence in the quaternary ... brogi a., lazzarotto a., liotta d., ranalli g. & crop 18 working group (2005) crustal structures in the gepthermal areas of southern tuscany (italy): insights from the crop 18 deep seismic reflection lines. journal of volcanology and geothermal research, 148, 60-80. capezzuoli e. & gandin a. (2004) i “travertini” in italia: proposta di una nuova nomenclatura basata sui caratteri genetici. il quaternario, 17 (2/1), 273-284. capezzuoli e. & sandrelli f. (2004) i sedimenti quaternari del settore meridionale della valdelsa (provincia di siena). il quaternario, 17(1), 33-40. carmignani l., decandia f.a., disperati l., fantozzi p.l., lazzarotto a., liotta d. & meccheri m. (1994) tertiary extensional tectonics in tuscany (northern apenines, italy). tectonophisics, 238, 295-315. costantini a., gandin a., guasparri g., lazzarotto a., mazzanti r. & sandrelli f. (1980) neotettonica dei fogli: 111 livorno – 112 volterra – 113 castelfiorentino – 119 massa marittima – 120 siena – 121 montepulciano – 126 isola d’elba – 127 piombino – 128 grosseto – 129 s.fiora. in: contributi al la realizzazione della carta neotettonica d’italia. pubbl. p.f.g., 1075-1186. costantini e.a.c. & carnicelli s. (1986) forme e suoli della superficie strutturale calcarea di campiglia dei foci (siena). annali ist. sper. dif. suolo, 17, 68-87. dallmeyer r.d. & lotta d. (1998) extension, uplift of rocks and cooling ages in thinned crustal provinces: the larderello geothermal area (inner norther apennines, italy). geological magazine, 135, 193202. dramis f., materazzi m. & cilla g. (1999) influence of climatic changes on freshwater travertine deposition: a new hypothesis. phys. chem. earth (a), 24(10), 893-897. ford t. d. & pedley h.m. (1996) a review of tufa and travertine deposits of the world. earth sci. rev., 41, 117-175. goudie a.s., viles h.a. & pentecost a. (1993) the lateholocene tufa decline in europe. the holocene, 3(2), 181-186. hancock p.l., chalmers r.m.l., altunel e. & cakir z. (1999) travitonics: using travertines in active fault studies. journal of structural geology, 21, 89, 903-916. manganelli g. & giusti f. (1993) notulae malacologicae, xlv. fossil parmacellidae from italy. arch. molluskenkunde, 121, 143-156. manganelli g., benocci a., capezzuoli e. & giusti f. (2005) pseudotachea boettger, 1909 (gastropoda: pulmonata, helicidae) from the nonmarine middle pleistocene of the valdelsa basin (central italy) . bollettino della società paleontologica italiana, 44 (2), 117-125. modena. merla g. & bortolotti v. (1967) note illustrative della carta geologica d’italia alla scala 1:100.000. foglio 113 – castelfiorentino. nuova tecnica grafica, roma. petronio c. & sardella r. (1999) biochronology of the pleistocene mammal fauna from ponte galeria (rome) and remarks on the middle galerian faunas . rivista ital iana di paleontologia e stratigrafia, 105, 1, 155-164. pedley h.m. (1990) classification and environmental model of cool freshwater tufas. sedimentary geology, 68, 143-154. pedley m., gonzalèz maartìn j.a., ordoñèz delgado s. & garcia del cura m.a. (2003) sedimentology of quaternary perched springline and paludal tufas: criteria for recognition, with examples from guadalajara province, spain. sedimentology, 50, 23-44. platt, n.h. & wright, v.p. (1991) lacustrine carbonates: facies models, facies distribution and hydrocarbon aspects. in: anadon, p., cabrera, l. and kelts, k. (eds.): lacustrine facies analysis. spec. publ. int. ass. sedimentol., 13, 57-74. raia p., piras p. & kotsakis t. (2005) turnover pulse or red queen? evidence from the large mammal communities during the plio-pleistocene of italy. palaeogeography, palaeoclimatology, palaeoecology, 221, 293-312. sagri m., martini i.p, cavinato g.p., pascucci v., sandrelli f. (2004) regional geologic setting. in: sedimentary and tectonic evolution of selected neogene-quaternary basins of the apennines (italy). 32° i.g.c., field guide book, p 15, 3-7. santangelo n. (2003) interazione tra tettonica recente e processi geomorfici. il quaternario, 16(1), 27-34. 166 ms. ricevuto il 27 giugno 2006 testo definitivo ricevuto il 12 settembre 2006 ms. received: june 27, 2006 final text received: september 12, 2006 e. capezzuoli & f. sandrelli imp.iannace uu//tthh ddaattiinngg aanndd ggeeoocchheemmiissttrryy ooff ccaarrbboonnaattee ccoonnccrreettiioonnss aassssoocciiaatteedd wwiitthh uuppppeerr pplleeiissttoocceennee ffoossssiill sshhoorreelliinneess ooff tthhee ssoorrrreennttoo ppeenniinnssuullaa ((ccoonnccaa ddeeii mmaarriinnii,, ssoouutthheerrnn iittaallyy)) aalleessssaannddrroo iiaannnnaaccee11,, ppaaoollaa rroommaannoo11 && ppaaoollaa ttuucccciimmeeii22 1dipartimento di scienze della terra, università di napoli federico ii, napoli, italia, aleianna@unina.it, paromano@unina.it; 2dipartimento di scienze geologiche, università "roma tre", roma, italia, tuccimei@uniroma3.it abstract u-series dating and geochemical analyses were performed on carbonate concretions in order to put chronological constraints on the associated fossil shorelines. in particular, samples were taken from concretions found at conca dei marini cape where former shorelines ascribed to the upper pleistocene are present. from the chronological data the height of sea level during highstands of late pleistocene is inferred; moreover, due to the tectonic stability of the area the estimated height could be taken as a close approximation of eustatic sea level position. a +3.5 m a.s.l. sea level highstand which occurred during the end of oxygen isotopic stage (ois) 5e was recognised by the u/th age and elevation of the concretion covering a wave-cut platform. furthermore, new interpretations for more recent sea level highstands were obtained by analyses performed on two calcitic concretions associated with a marine biocalcarenite. they indicate that the sea level at the end of ois 3 was close to the present day one; such a conclusion disagrees with the generally accepted sea levl position derived from proxy data taken from oceanic cores while it agrees with recent chronological data obtained from marine deposits in the gulf of taranto (southern italy). riassunto in due siti della penisola sorrentina , presso il capo di conca dei marini, sono state rinvenute alcune concrezioni carbonatiche in associazione con depositi e forme marine ascritte in letteratura agli stazionamenti alti del livello marino correlati con lo stadio 5 della stratigrafia basata sugli isotopi dell'ossigeno. su queste concrezioni sono state eseguite datazioni u/th al fine di ottenere ulteriori vincoli cronologici (limiti ante quem o post quem) per la genesi delle linee di riva, ed analisi sedimentologiche e geochimiche indirizzate alla determinazione del loro ambiente diagenetico. le condizioni di stabilità tettonica tardo quaternaria caratterizzanti l'area in studio hanno consentito, inoltre, di porre in relazione la posizione altimetrica dei depositi e delle forme cronologicamente inquadrati ad altrettante posizioni eustatiche del livello marino durante gli stadi isotopici 5 e 3 del pleistocene superiore. fra i risultati più interessanti si segnalano quelli ottenuti da una concrezione laminare datata al sottostadio 5d che ricopre una piattaforma di abrasione posta a +3,5 m s.l.m., la cui genesi va così inquadrata nella parte finale del sottostadio 5e, e le datazioni di due concrezioni calcitiche che si intercalano ad una biocalcarenite marina a + 4 m s.l.m. queste ultime, datate allo stadio3, suggeriscono una posizione del livello marino per quel periodo prossima al livello marino odierno; tale conclusione da un lato contrasta con quanto sinora proposto in letteratura sulla base di dati indiretti ottenuti da carote oceaniche, d'altra parte è in accordo con recenti dati ottenuti su depositi marini affioranti sulle coste del golfo di taranto. key words: emerged shorelines, calcareous concretions, geochemistry, u-series data, upper pleistocene, southern italy. parole chiave: linee di riva, concrezioni calcaree, geochimica, datazioni u/th, pleistocene superiore, italia meridionale. il quaternario italian journal of quaternary sciences 1166(1bis), 2003, 49-54 11.. iinnttrroodduuccttiioonn the sorrento promontory is a ne-sw trending horst facing capri island along the coast of the campania region (fig.1). highly resistant rocks – carbonates of meso-cenozoic age – displaced by normal faults in structural blocks constitute the promontory. as such, the peninsula is characterised by a structure-controlled type of coast with high and rectilinear sea cliffs interrupted by angular plan-shaped bays and pocket beaches. offshore, plunging cliffs alternating with narrow coastal benches are generally present. similarly, the quaternary fossil shorelines of the peninsula are represented by scattered and small remnants of marine terraces and by scarce outcrops of coarse-textured beach deposits patched onto the bedrock and usually barren. there are a very few sites where fossiliferous pleistocene marine deposits are present such as the well known ieranto and conca dei marini bays, where eutyrrhenian marine deposits were pointed out (brancaccio et al., 1978). in this paper we present new chronological data on the upper pleistocene fossil shorelines of the sorrento peninsula. they have been obtained by useries data performed on carbonate concretions which we have found closely or directly associated with some sea level stand indicators, both of erosional and depositional origin, in conca dei marini area. 22.. ggeeoommoorrpphhoollooggyy,, ssttrraattiiggrraapphhyy aanndd sseeddiimmeennttoollooggyy two sites of conca dei marini promontory (site i and site ii in fig.1) have been studied in detail in this paper. the upper pleistocene shorelines are represented by patches of marine deposits and by bioerosive notches and emerged platforms, located at elevation 50 a. iannace, p. romano & p. tuccimei between +8 and +1.5 m. they were studied in brancaccio et al. (1978), cinque & romano (1990), riccio et al. (2001). in site i several carbonate concretions associated with a + 8 m high notch have been found (fig.2). the concretions are finely laminated and fill bowl-like cavit ies present all along the notch concavity. microscopically, the concretions consist of alternation of microsparitic laminae. xrd analyses revealed the presence of some aragonite together with calcite. the origin of the cavities and carbonated infilling appears very problematic. possibly, the cavities originated as lithophaga sp. burrows and were subsequently enlarged by chemical weathering. the former studies carried fig. 1 geological scheme of the sorrento peninsula with the locations of the conca dei marini promontory and of the site i and site ii bays (after riccio et al., 2001 modified). fig. 2 geological section of site i bay (after riccio et al., 2001 modified). the photographs show a detailed and a complete view of the concretions present all along the + 8 m high notch. 51u/th dating and geochemistry ... fig. 3 geological section of site ii bay. for details of the concretions see fig. 4. fig. 4 details of the calcareous concretions associated with marine deposits or erosional morphologies at site ii bay. a) the concretion lying onto the +3.5/4 emerged bench, 2/4 cm thick. b) the concretions cementing the upper part of a marine calcarenite, 1/2 cm thick. 52 out in the area (brancaccio et al., 1978; riccio et al., 2001) indicated an euthyrrenian age of the + 8 m notch because it is closely associated with a marine deposit with cladocora coespitosa. in site ii different generations of calcareous concretions were found closely or directly associated with emerged shorelines (fig. 3). some platy, laminated calcitic concretions (fig.4a) lie onto a +3.5/4 m high wavecut platform which was tentatively ascribed to a late oi substage 5e sea level stand by riccio et al. (2001). other generations of concretions intercalated in the upper part of a marine calcarenite at +4 m a.s.l. (fig. 3 and fig. 4b) were observed. the marine deposit covers the +3.5/4 m high emerged platform and there it is only some 60 cm thick; laterally, instead, the deposit thickens to some 100 cm because it fills a sheltered niche whose bottom is 1 m lower than the terrace and is cut directly into the mesozoic carbonates of the substrate. the deposits are distinctly clinostratified and dip landward with a fan-shaped bedding which progressively compensates the difference in accomodation space between the terrace and the niche. this demonstrates that the protected niche was filled gravitationally by sediments coming from the sea-ward side and washed over the threshold represented by the bench. the sediments, as reported in riccio et al. (2001), consist of a matrix-free coarse calcarenite to calcirudite. the part of deposits closer to the sea is distinctly coarser, with single grains reaching some cm in diameter. grains are subrounded and show a good sorting within each layer. they consist mainly of bioclasts and lithoclasts of coarse-crystalline dolomites. only one layer, at 80 cm, consist mostly of more angular and reddened lithoclasts. the bioclasts are represented mainly by fragments of articulate and inarticulate bivalvs, gastropods, bryozoan and echinoderms and of red algae. frequent are also micritic grains of unknown origin. the deposit is generally highly porous and crumbly because of a very low degree of cementation. in fact, in the thin section, only an irregular, discontinuous rim of limpid, equant calcite cement is present showing frequently meniscus textures. only a few layers in the upper part of the deposits are heavily cemented by several laminated carbonate concrections. the concretions are represented by several mm thick laminated layers consisting exclusively of precipitated carbonate which interrupt the sedimentary layering (fig 4b and 5). however, there are also calcarenite layers made harder by the presence of the same carbonate precipitate covering the sigle grains. the geometric relations between cement and sediment layers demonstrate that most of the cementation took place during deposition. moreover, it is clear from field relations that for the latest concrections, downward, stalactitic growth on cavity floor was contemporaneous with upward growth on the sediment surface, probably as a flowstone. the microstructures are characterised by alternating laminae of spar and microspar often showing the presence of fibrous structures due to the crystallographic continuity of single crystals of each superposed lamina. this especially occurs when the laminae are not planar but form domes and arches. in the case of upward growth on the sediment surface these structures are comparable to those of stromatolites according to the definition of de micco & hardie (1994). otherwise, they are typical of coconut calcite in stalactitic growth. these concrections are morphologically comparable to many spleothems but also to some carbonates formed in special conditions in supersaturated marine waters, as suggested by riccio et al. (2001). 33.. ggeeoocchheemmiissttrryy the several carbonate concrections at conca dei marini are the only available material to constrain cronologically the associated sediments and erosional features. to this aim, several samples have been collected from: the concrections cementing the upper part of the biocalcarenite at site ii, both in the stalactitic (samples cm5) and stalagmitic (sample cm4) portions; the problematic circular concrections partly covering the +8 m notch at site i (sample cm1); the concrection covering the coastal bench at 3.5-4 m at site ii (samples cm6); from the collected material, four samples have been analysed by u-series disequilibria, nine for o and c stable isotopes. the list of samples and results are shown in tables 1 and 2. for u-series disequilibria measurements, samples were crushed into several-millimetre-diameter pieces with a stainless-steel chisel. these fragments were examined under a binocular microscope and any piece that a. iannace, p. romano & p. tuccimei fig 5 details of the stalactitic (cm4) and the stalagmitic (cm5) portions of the concrections cementing the marine calcarenite at site ii. 53 showed signs of secondary alteration was discarded. the remaining portion was ultrasonically cleaned in distilled water twice. the analytical procedure used for u and th separation was that reported by bischoff et al. (1988). three to six gram samples were spiked with a 228th + 232u tracer (in secular equilibrium) and activity ratios were counted in an eg&g ortec 920-8 alpha spectrometer system. the ages and the initial 234u/238u activity ratios were calculated by means of isoplot, a plotting and regression program designed by ludwig (1994) for radiogenic-isotope data. the uranium contents, the activity ratios and the calculated 230th ages are listed in table 1; all errors are reported as 1 sigma. for o and c isotope ratios measurements, a few mg of powder have been obtained with a dental drill from areas which are exclusively formed of precipitated carbonates. carbonate powders were reacted with 100% phosphoric acid at 75 °c and analysed in a carbonate preparation line connected to a finnigan mat 252 mass spectrometer. the analyses have been carried out at the stable isotope laboratory of erlangen university (germany). results are shown in table 2. all the subsamples extracted from cm4 and cm5 samples have δ13c and δ18o isotope values ranging from -3,7 to -8,1 and from -2,2 to -3,5 (pdb) respectively. these values, especially the c-isotope ratios, indicate precipitation from meteoric waters. the relatively marked variation within the sample set cannot be explained precisely and has to be attributed to temperature and compositional variation in the parent fluid, both possibly linked to seasonal or climatic factors. the initial 234u/238u activity ratios calculated from two samples of the same concretions are 1.05 and 1.07, both not consistent with the average uranium composition of the oceans (about 1.15). the only isotopically different carbonate is represented by the cavity-filling concretions found at +8 m at site i (cm1). in fact, a single measurement performed on this material gave δ18o and δ13c values of -0.1 and -0.8 (pdb) respectively, distinctly heavier than the other samples. part of this difference can be attributed to the presence of aragonite in these concretions, which has a slightly higher fractionation factor with respect to calcite, both for carbon (1.8 per mil) and oxygen (0.6 per mil). however, the measured value implies at least a partial contribution of marine waters during precipitation. a simple evaporation effect on meteoric waters can be excluded because this would have raised the measured o-isotopes ratios but not the c-isotopes ones. this interpretation is further strengthened by u-geochemistry. in fact, both u-content and 234u/238u activity ratios are higher than in the cm 4 and 5 samples, this again suggesting a marine contribution in the precipitation of these concrections. for cm6, sample u-data suggest a meteoric origin and a single δ18o and δ13c measurement seems to confirm this. 44.. ddiissccuussssiioonn the chronological data obtained at conca dei marini (table 1) permit to infer the height of sea-level during high-stands of the late pleistocene. the estimated height can be taken as a close approximation of eustatic sea level positions. in fact, as pointed out in brancaccio et al. (1978) and riccio et al. (2001), the conca dei marini sites have suffered a maximum uplift of 1.5 m since the eutyrrhenian, corresponding to a mean rate of 10-2 mm/a. the calculated age for the concrection covering the +3.5 m bench (cm6) is 109.1 ka (table 1), which falls within oi substage 5d (martinson et al. 1987). this only represents an upper limit for the age of the bench. the lower one is the eutyrrhenian because the bench can be correlated to a +3.5 notch cutting the cladocora deposit (see fig. 2), as discussed in riccio et al. (2001). thus, the geochronological data confirm the hypothesis that this highstand occurred during late substage 5e. however, the ages of the other concrections proviu/th dating and geochemistry ... table 1 u-series data, mineralogy and inferred isotope stage of samples from conca dei marini (italy). quoted ratios are activity ratios and errors are expressed as 1 sigma. (234u/238u)init. represents the initial uranium ratio. sample mineralogy u ppm (230th/232th) (234u/238u) (230th/234u) (234u/238u)init. age (ka) stage cm1 aragonite+ 3.439 ± 0.098 25 ± 1 1.126 ± 0.014 0.387 ± 0,015 1.146 ± 0.016 52.7 ± 2.6 3 mg calcite cm4 calcite 1.878 ± 0.035 75 ± 10 1.059 ± 0.017 0.424 ± 0.012 1.07 ± 0.02 59.6 ± 2.2 3 -4 cm5 calcite 1.211 ± 0.022 34 ± 3 1.043 ± 0.017 0.397 ± 0.011 1.050 ± 0.020 54.8 ± 2 3 cm6 calcite 0.514 ± 0.016 856 ± 792 1.057 ± 0.034 0.638 ± 0.025 1.078 ± 0.046 109.1 ± 7.3 5d table 2 c and o isotope ratios measured on conca dei marini concretions. sample δ13c std.dev. δ18o std.dev cm1 -0.8 0.02 -0.2 0.02 cm 4a -7.2 0.03 -3.0 0.03 cm 4b -8.1 0.02 -3.5 0.02 cm 4c -5.5 0.02 -3.2 0.04 cm 4d -5.5 0.03 -3.3 0.06 cm 5a -5.7 0.02 -2.5 0.03 cm 5b -6.1 0.02 -2.4 0.05 cm 5c -3.7 0.02 -2.2 0.06 cm 5d -5.5 0.01 -2.6 0.02 cm 6 -6.5 0.04 -4.1 0.04 54 de new interpretations for more recent sea level highstands. in fact, u-series data indicate an age of approximately 54-59 ka for the cm 5 and cm 4 concrections respectively (table 1), which can be considered as an estimate of the age of the bioclastic deposits. these ages correspond to the beginning of ois 3. the sedimentological evidence indicates clearly that the deposits formed as a backshore deposit washed over the bench into a sheltered niche on the rocky coast during storms. considering the height of the marine calcarenite, this would indicate that the contemporaneous sea level was not so far from the present day one. such a conclusion disagrees with the largely accepted assumption that the sea level during the whole ois 3 was some tens of meter below the present one. this conclusion is generally derived from proxy data, specifically by assuming a more or less direct relationship between o-isotope values in oceanic foraminifers and ice-volume (chappel & shakcleton, 1986). however, recent research in the mediterranean area has found a little sedimentological evidence, supported by geochronological data, of a highstand above the present sea level during ois 3 (belluomini et al., 2002). our data provide further support to these findings. the uand o-c isotope geochemistry of the problematic concrections of + 7/8 m at site 1 represents a further possible evidence that sea level was close to the present one during ois 3. in fact, the calculated age is 52 ka and u content and o and c isotope ratios indicate a precipitation by a fluid with a partial marine contribution. a possible explanation is that sea water came from marine spray over the rocky cliffs. we think that the data of conca dei marini and those reported by belluomini et al (2002) impose further research in other areas, coupled with a critical review of published data concerned with recent sea level highstands, in order to definitively verify the validity of the generally accepted late pleistocene sea level curves. aacckknnoowwlleeddggeemmeennttss this paper was financially supported by cnr n.99.00646 ct05 grant: "ricostruzione delle principali variazioni indotte sui sistemi geomorfici dalle flutuazioni climatiche tardo quaternarie e storiche", local chief scientist prof. a. cinque. rreeffeerreenncceess belluomini g., caldara m., casini c., cerasoli m., mandra l., mastronuzzi g., palmentola g., sansò p., tuccimei p. & vesica p.l. (2002) the age of late pleistocene shorelines and tectonic activity of taranto area, southern italy. quaternary science reviews, 2211, 525-547. bishoff j.l., rosenbauer r.j., tavoso a. & lumley h. (1988). a test of uranium-series dating of fossil tooth enamel: results from tautavel cave, france. applied geochemistry, 33, 145-151. brancaccio l., capaldi g., cinque a., pece r. & sgrosso i. (1978) 230th-238u dating of corals from a tyrrhenian beach in sorrentine peninsula (southern italy) quaternaria, 2200, 175-183. chappel j. & shackleton n.j. (1986) oxygen isotopes and sea level. nature, 332244, 137-140. cinque a. & romano p. (1990) segnalazione di nuove evidenze di antiche linee di riva in penisola sorrentina (campania) geogr. fis. dinam. quat., 1133 (1), 23-36. demicco r. v. & hardie l. a. (1994) sedimentary structures and early diagenetic features of swallow marine carbonate deposits. soc. of econom. paleontol. and mineralog. atlas series, 11, tulsa, 265 pp. ludwig k.r. (1994). isoplot. a plotting and regression program for radiogenic-isotope data. version 2.75. u.s. geological survey, open-file report, 91-445. martinson d.g., pisias n.g., hays j.d., imbrie j., moore t.c. & shackleton n.j. (1987) age dating and the orbital theory of the ice ages: development of a high resolution 0-300,000 year chronology. quaternary research, 2277, 1-29. riccio a., riggio f. & romano p. (2001) sea level fluctuation during oxygen isotope stage 5: new data from fossil shorelines in the sorrento peninsula (southern italy) z. geomorph. n.f., 4455 (1), 121-137. a. iannace, p. romano & p. tuccimei impaginato giraudi llee oosscciillllaazziioonnii ddeell gghhiiaacccciiaaiioo ddeell ccaallddeerroonnee ((ggrraann ssaassssoo dd''iittaalliiaa,, aabbrruuzzzzoo - iittaalliiaa cceennttrraallee)) ee llee vvaarriiaazziioonnii cclliimmaattiicchhee ddeeggllii uullttiimmii 33000000 aannnnii ccaarrlloo ggiirraauuddii enea c.r. casaccia, c.p. 2400, 00100 roma a.d. riassunto i detriti di origine glaciale conservati appena a valle della soglia del circo del ghiacciaio del calderone, sono stati inquadrati dal punto di vista cronologico grazie alla datazione di suoli ad essi intercalati e sovrapposti. le date indicano quattro espansioni glaciali: la prima successiva a 2650±60 anni radiocarbonio bp, la seconda compresa tra 1450±40 e 670±40 anni bp, la terza successiva a 670±40 anni bp, l'ultima databile al xix secolo. le espansioni del ghiacciaio del calderone possono essere correlate con fasi di avanzata dei ghiacciai alpini. per cercare di individuare con maggiore precisione i periodi favorevoli all'espansione glaciale e per ridurre, quindi, l'incertezza delle datazioni, si é fatto ricorso all'esame delle variazioni di livello dei laghi fucino e trasimeno; questi, in base alla letteratura, aumentavano di livello in sintonia con le fasi di avanzata glaciale. dal confronto si deduce che la prima espansione glaciale (calderone 2) sarebbe databile al periodo compreso tra vii e ii÷iii secolo bc, la seconda (calderone 3a) sarebbe databile ad un periodo compreso tra i secoli vii e x ad, la terza (calderone 3b) sarebbe databile tra il xvi e parte del xix secolo ad, l'ultima (calderone 3c) dovrebbe risalire al xix secolo ad. di conseguenza dovettero verificarsi fasi di riscaldamento climatico che produssero contrazioni dei ghiacciai tra il iii÷ii secolo bc ed il vi secolo ad, tra il x e il xiii secolo ad ed alla fine del xix secolo ad. in base alle differenze di limite nivale, la temperatura media annuale nel corso delle fasi di massima avanzata glaciale doveva essere inferiore all'attuale di almeno 1,1° ÷ 0,8°c. abstract the variations of the calderone glacier (gran sasso d'italia, abruzzo, central italy) and the climatic oscillations during the last 3000 years. the age of the debris of glacial origin, lying just downvalley of the threshold of the cirque of the calderone glacier, has been obtained dating interbedded soils by means of radiocarbon analysis. the datings point out four glacial expansions: the first, following 2650±60 years bp, the second bracketed between 1450±40 and 670±40 years bp, the third following 670±40 years bp, the last datable to the xix century. the expansions of the calderone glacier can be correlated to the advances of the alpine glaciers. in order to try to date with greater precision the periods favourable to expandig glacier and to reduce the uncertainty of the datings, the variations of the fucino and trasimeno lakes have been considered; these lakes, according to previous works, increased in level during the glacial advances. the comparison between lake and glacial data indicates that the first glacial advance (stage calderone 2) occurred during the period between the vii and the ii÷iii century bc, the second (stage calderone 3a) between the vii and x century ad, the third (stage calderone 3b) between the xvi and part of the xix century ad, the last (stage calderone 3c) during the xix century ad. as a consequence, one can assume that some climatic warmings took place producing glacial retreat between iii÷ii bc and vii century ad, x and xiii century ad, and at the end of the xix century ad. based on the differences in the equilibrium line altitude, the mean yearly temperature during the periods of maximum glacial advance must have been lower than the present one of, at least, 1,1° ÷ 0,8°c. parole chiave: gran sasso, ghiacciaio del calderone, variazioni glaciali, clima olocene, piccola età glaciale. keywords: gran sasso massif, calderone glacier, glacial oscillations, holocene climate, little ice age. il quaternario italian journal of quaternary sciences 1155(2), 2002, 149-154 iinnttrroodduuzziioonnee sul massiccio del gran sasso (2912 m), posto a circa 42°30' n nell'appennino centrale, è presente il ghiacciaio del calderone, il più meridionale d'europa. il ghiacciaio è per lo più un "debris covered glacier" che raggiunge lo spessore massimo di circa 15 m (gellatly et al., 1992; smiraglia & veggetti, 1992; d'orefice et al., 1996; fiucci et al., 1997). tale ghiacciaio è in forte riduzione a partire dagli anni '60, dopo una fase di regresso più contenuta che durava almeno dall'inizio del '900 (marinelli & ricci, 1916; tonini, 1961; smiraglia & veggetti, 1991; gellatly et al., 1992, 1994). il ghiacciaio sopravvive al di sotto del limite delle nevi teorico calcolato da tonini (1961) a causa delle condizioni locali, essendo conservato in un circo rivolto a ne tra ripide pareti dirupate. vari autori (federici,1979; gellatly et al., 1992,1994; jaurand,1994) hanno avanzato ipotesi sull'età di alcune forme e depositi glaciali presenti a valle o sulla soglia del circo del calderone, ma solo recentemente (giraudi, 2000) sono state utilizzate datazioni radiometriche per inquadrare le fasi di espansione, dimostrando che il ghiacciaio del calderone, scomparve nelle fasi più calde dell'olocene, e si riformò (stadio calderone 1) in un periodo successivo a 3895±65 anni bp, quando il limite nivale (ln) raggiunse circa 2750 m. in seguito il ghiacciaio fu soggetto ad altre fasi di espansione: la prima (stadio calderone 2, con ln 2750÷2770 150 c. giraudi m) successiva a 2650±60 anni bp (data calibrata 2 sigma 905÷775 bc), la seconda, più complessa, (stadio calderone 3a, b, c), attribuita alla piccola età glaciale, con ln inferiore o uguale a 2730 m. scopo del presente lavoro é quello di datare le morene degli stadi calderone 2, 3a,b,c, vale a dire i depositi prodotti dalle espansioni glaciali degli ultimi 3000 anni, al fine di determinare se vi sono correlazioni tra le avanzate glaciali appenniniche ed alpine e di valutare le oscillazioni climatiche che le hanno prodotte. mmeettooddii il metodo di lavoro adottato nella presente ricerca è basato sulla datazione di suoli intercalati o sovrapposti ai detriti glaciali conservati a poche centinaia di metri dalla soglia del circo glaciale. il circo che ospita il ghiacciaio del calderone è sospeso alla testata della valle delle cornacchie; poco oltre la sua soglia la valle assume pendenze molto elevate, passando dal 17%, al 60-÷70% in media, ma con tratti caratterizzati da gradini sub-verticali. come discusso in un altro lavoro (giraudi, 2000), quando la lingua glaciale superava la soglia del circo, il ghiaccio precipitava a valle, così come il detrito glaciale. in corrispondenza di tratti del fondovalle leggermente meno inclinati si formavano quindi falde di detrito discontinue (2, 4 e 5 in fig. 1), la geometria delle quali indica chiaramente la zona di alimentazione e quindi l 'apparato morenico di provenienza. questa situazione appare partifig. 1 carta geologica schematica dei depositi glaciali e dei detriti studiati presenti nell'area sommitale del corno grande, massiccio del gran sasso. legenda: 1detrito di versante; 2detrito glaciale dello stadio calderone 3b; 3morene degli stadi calderone 3b,c; 4morene e detrito glaciale dello stadio calderone 3a; 5morene e detrito glaciale dello stadio calderone 2; 6morene dello stadio calderone 1; 7morene dello stadio franchetti; 8morene dello stadio cornacchie; 9circo del calderone; 10cordone morenico; 11nivomorena. geological sketch map of the studied glacial and slope waste deposits near the calderone glacier (corno grande-gran sasso massif). legend: slope waste deposits; 2stage calderone 3b glacial debris; 3stage calderone 3b,c moraines; 4stage calderone 3a moraine and apron of fallen glacial debris; 5stage calderone 2 moraine and apron of fallen glacial debris; 6stage calderone 1 moraines; 7stage franchetti moraine; 8stage cornacchie moraine; 9cirque of the calderone glacier; 10moraine ridge; 11protalus rampart. colarmente evidente per lo stadio calderone 3a,b, ma è riconoscibile anche per lo stadio calderone 2, le cui morene frontali sono conservate sulla soglia del circo glaciale. rilevando la distribuzione dei detriti collegati ai vari apparati morenici frontali, ricostruendo i loro rapporti stratigrafici e campionando suoli sepolti o sovrapposti ai detriti, é stato possibile ottenere la datazione delle ultime espansioni del ghiacciaio del calderone. rriissuullttaattii la carta geologica schematica di fig. 1 evidenzia i depositi glaciali e le falde detritiche prese in considerazione nel presente lavoro. il più antico degli accumuli di detrito presi in considerazione (5 in fig. 1) é formato prevalentemente da clasti grossolani eterometrici, con scarsa matrice, e mostra di essere stato alimentato dal fronte delle morene dello stadio calderone 2. il detrito presenta una scarsissima copertura vegetale, ma scavando tra i clasti si possono rinvenire, a luoghi, i resti di un suolo sabbioso-limoso non visibile in superficie. il suolo deve essere stato dilavato quasi totalmente, conservandosi solo in piccoli lembi laddove é stato coperto da detrito messo in posto da processi crio-nivali superficiali. nella zona del rifugio franchetti (circa 400 m dalla soglia del circo, alla quota di circa 2450 m) il detrito glaciale (fig. 2) é interdigitato con detrito derivante da una piccola scarpata adiacente. il detrito di versante, che risulta assai più fine e con abbondante matrice sabbiosa, copre un suolo (giraudi, 2000) datato 2650±50 anni bp col metodo del radiocarbonio (calibrato 2 sigma 905÷775 bc). il secondo accumulo detritico (4 in fig. 1), ancora 151le oscillazioni del ghiacciaio del calderone ... costituito da clasti grossolani eterometrici, ma di dimensioni leggermente minori rispetto al precedente, mostra di essere stato alimentato dalle morene dello stadio calderone 3; si sovrappone al detrito della prima fase (5 in fig. 1) e copre anche una nivomorena. nella zona del rifugio franchetti, il detrito di origine glaciale appare interdigitato con detrito di versante (fig. 2). questo, ben distinguibile dagli altri per la presenza di molta matrice sabbiosa, copre un suolo grigio scuro datato 1450±40 anni bp col metodo del radiocarbonio (data calibrata 2 sigma: ad 540÷660). anche in questo caso, sul detrito glaciale la copertura vegetale é estremamente ridotta ma, scavando tra i clasti, si possono rinvenire i resti, coperti da poco detrito fine, di un suolo limoso grigio scuro ricco di sostanza organica; questo, sottoposto a datazione col metodo del radiocarbonio, ha fornito un'età di 670±40 anni bp (data calibrata 2 sigma: ad 1270÷1400). il suolo deve essere stato dilavato quasi completamente, ma si é conservato in piccoli lembi laddove é stato coperto da detrito mobilizzato da processi crio-nivali superficiali. il terzo accumulo detritico (2 in fig. 1) è il più continuo arealmente, risulta formato da clasti di dimensioni inferiori rispetto ai precedenti, e presenta matrice sabbiosa limosa più abbondante. su tale accumulo la copertura vegetale é praticamente assente: non sono stati rinvenuti suoli o resti di suoli. i clasti di roccia carbonatica hanno aspetto molto fresco ed in alcune zone il detrito appare interessato da piccoli debris flow, legati a fenomeni di instabilità attuale. il detrito é direttamente collegato alla morena dello stadio calderone 3b, e copre quello della seconda fase (4 in fig. 1). vista la situazione stratigrafica, si assume quindi che il secondo deposito detritico sia contemporaneo alla formazione delle morene dello stadio calderone 3a, precedenti a quelle dello stadio calderone 3b. ne emerge un inquadramento cronologico per le fasi di espansione glaciale che può essere così riassunto: la fase di espansione glaciale che ha dato luogo alla formazione delle morene dello stadio calderone 2 è più recente di un suolo datato 2650±50 anni bp e più antico di un suolo datato 1450±40 anni bp; la fase di espansione glaciale che ha prodotto le morene dello stadio calderone 3a è successiva ad un suolo datato 1450±40 anni bp e precedente ad un ulteriore suolo datato 670±40 anni bp; fig. 2 schema dei rapporti stratigrafici tra i detriti di origine glaciale e di versante nella zona del rifugio franchetti. legenda: 1detrito glaciale dello stadio calderone 3a con lembi di suolo conservati al tetto; 2detrito di versante eteropico con il detrito glaciale dello stadio calderone 3a; 3detrito glaciale dello stadio calderone 2 con lembi di suolo conservati al tetto; 4detrito di versante eteropico con il detrito glaciale dello stadio calderone 2; 5detrito di versante; 6suoli sepolti stratigraphyc sketch of the glacial and slope debris near rifugio franchetti. legend: 1stage calderone 3a glacial debris with remnants of a soil at the top; 2slope waste deposits heteropic with stage calderone 3a glacial debris; 3stage calderone 2 glacial debris with remnants of a soil at the top; 4slope waste deposits heteropic with stage calderone 2 glacial debris; 5older slope waste deposit; 6interbedded soils. 152 c. giraudi la fase di espansione nel corso della quale si sono formate le morene dello stadio calderone 3b é successiva al suolo datato 670±40 anni bp; la fase di espansione che ha dato luogo alle morene dello stadio calderone 3c è molto vicina al fronte glaciale documentato per la fine del xix secolo e dovrebbe quindi risalire allo stesso periodo. ddiissccuussssiioonnee l'inquadramento cronologico delle fasi di espansione glaciale é stato ottenuto mediante datazione di suoli coperti da detrito. quando si datano i suoli col metodo del radiocarbonio, la data che si ottiene indica l'età media delle sostanze organiche presenti al momento del seppellimento (matthews, 1993). il seppellimento ad opera di detrito caduto dal fronte glaciale coincide con il superamento, da parte del ghiacciaio, della soglia del circo: le massime estensioni degli stadi calderone 2, 3a e 3b, sono quindi state raggiunte in un momento che può essere anche sensibilmente successivo alle date indicate dai suoli. nonostante l'approssimazione insita nelle date, possiamo correlare la fase di espansione glaciale calderone 3b (successiva a 670±40 anni bp/ cal. 1270÷1400 ad) alla piccola età glaciale. lo stadio calderone 3a appare databile al periodo medioevale (successivo alla copertura del suolo datato 1450±40 bp/ cal.540÷660 ad) e precedente allo sviluppo del suolo datato 670±40 anni bp/ cal. 1270÷1400 ad. lo stadio calderone 2, successivo a 2650±50 anni bp/ cal. 905÷775 bc e precedente a 1450±40 bp/ cal.540÷660 ad, cade nell'età del ferro o nel periodo romano. il confronto tra le date ottenute sul massiccio del gran sasso e quelle conosciute per le espansioni glaciali degli ultimi 3000 anni sulle alpi mostra una buona corrispondenza, anche se alcune date ottenute dai suoli sepolti lasciano una ampia incertezza cronologica. orombelli & pelfini (1985) indica un'avanzata del ghiacciaio dei forni (ortles-cevedale) precedente a depositi torbosi datati 2670±130 bp, che potrebbe coincidere con lo stadio calderone 1 (precedente a quelli trattati nel presente lavoro, segnalato in giraudi, 2000). baroni & carton (1991) indicano un'avanzata del ghiacciaio di pisgana (adamello) successiva a 3015±75 bp e precedente a 2345±125 bp, che potrebbe corrisponde allo stadio calderone 2. orombelli & porter (1982) documentano un'avanzata del ghiacciaio della brenva (m. bianco) che ha prodotto la sepoltura, da parte di una morena, di un tronco datato 1170±75 anni bp (760÷980 cal. ad); strumia (1997) ha rinvenuto un suolo sepolto da un'avanzata del ghiaciaio del lys, datato 1185±80 anni bp (734÷980 cal. ad); questa avanzata dei ghiacciai alpini sembra corrisponde allo stadio calderone 3a del gran sasso. sulle alpi, a partire da xv secolo, cioé durante la piccola età glaciale si sono poi verificate molte avanzate glaciali, anche notevoli (per una sintesi vedasi baroni,2000), che appaiono quindi correlabili, nel complesso, agli stadi calderone 3b,c. ccoorrrreellaazziioonnee ttrraa aavvaannzzaattee ggllaacciiaallii eedd aallttrrii eevveennttii cclliimmaattiiccii iinn iittaalliiaa cceennttrraallee per tentare un migliore inquadramento cronologico delle fasi di espansione del ghiacciaio del calderone, si ritiene lecito fare ricorso al confronto con dati paleoclimatici rilevati in altre zone dell'italia centrale, in particolare alle oscillazioni di livello dei laghi. il primo riferimento é al lago del fucino, bonificato alla fine del xix secolo. questo lago, posto circa 50 km a sud del corno grande, tra le montagne abruzzesi, ha avuto negli ultimi 30.000 anni, ma anche in dettaglio nei secoli dal xvii al xix, oscillazioni di livello ben correlabili con le variazioni glaciali alpine ed appenniniche (giraudi, 1998). il lago aumentava di livello prevalentemente in concomitanza con le avanzate glaciali e diminuiva in corrispondenza delle fasi di ritiro. negli ultimi 3000 anni, il lago del fucino subì varie oscillazioni: la prima fase di incremento di livello del lago é successiva ad un manufatto in legno datato 2960±100 e precedente a ceramiche attribuite al periodo ii ÷ iii secolo b.c.: tale aumento può essere ritenuto sincrono con lo stadio calderone 2; considerando che il suolo coperto é datato 2650±50 bp, l'espansione glaciale deve essere datata tra circa 2600 e 2200÷2300 anni bp (vii ÷ iii/ii secolo bc); un nuovo aumento di livello ebbe luogo nel periodo compreso tra la sedimentazione di due orizzonti di torba che, per la quota di rinvenimento, sono indicatori di lago basso; la prima torba é stata datata 1375±75 (data calibrata: 630÷690 ad, cioé vii secolo ad), la seconda torba é stata datata 930±125 (data calibrata: 1000÷1250 ad, cioé secoli xi/xiii ad); tale aumento deve coincidere con lo stadio calderone 3a; nuovi forti aumenti di livello sono documentati a partire dal xvi secolo ad, con livelli particolarmente elevati nei primi anni del xvii secolo, nel secondo e nel sesto decennio del xix; tali oscillazioni coincidono quindi con gli stadi calderone 3b,c. a causa della mancanza di dati e delle opere di bonifica romana, le oscillazioni di livello del fucino dal i al iv secolo ad e nel periodo tra x e xvi secolo ad non sono ben conosciute. ma il lago del fucino non é l'unico lago in italia centrale ad avere avuto oscillazioni legate alle stesse fasi climatiche che hanno prodotto le espansioni dei ghiacciai: anche il lago trasimeno (umbria) presenta oscillazioni di livello estremamente interessanti per il presente lavoro. secondo gambini (1995, 2000), che ha studiato i resti di insediamenti umani lungo le sponde, il lago trasimeno, mostra livelli bassi nel periodo etruscoromano fino almeno al iv secolo ad, causato probabilmente dalla presenza di una galleria di drenaggio; in assenza di regimazione, i livelli del lago furono molto bassi nei secoli xi÷xii ad ed aumentarono nel corso del xiii e xiv secolo. il lago raggiunse quote tanto elevate che, nel xv secolo, il suo livello venne controllato mediante una galleria artificiale e la diversione di un corso d'acqua; la presenza del drenaggio non impedì il verificarsi di forti aumenti, che durarono alcuni anni, nel primo decennio del xvii secolo, tra il settimo e l'ottavo decennio del xviii secolo, e nel secondo decennio del xix secolo. 153le oscillazioni del ghiacciaio del calderone ... c'é quindi un'ottima correlazione tra le variazioni di livello del periodo post-romano dei laghi fucino e trasimeno. ne deriva che la fase fredda che ha dato luogo all'avanzata glaciale calderone 3a deve essere responsabile anche dell'aumento di livello lacustre terminato in un momento imprecisato precedente al secolo xi ad e che l'espansione glaciale calderone 3b deve essere successiva al xv secolo ad. le variazioni dei limiti nivali (ela) nel corso degli stadi calderone 2, 3a,b,c, possono fornire indicazioni sulle differenze di temperatura media annua tra le fasi di maggiore estensione del ghiacciaio del calderone e quella attuale. la quota di ela attuale deve essere superiore all'altezza del gran sasso (2912 m). infatti gellatly et al. (1994) riferiscono che almeno dalla fine degli anni '70 il ghiacciaio non é mai stato visto con neve residua degli anni precedenti. la massima espansione della piccola età glaciale indica che ela era a quote non superiori a 2730 m, con una differenza rispetto all'attuale di almeno 180 m. se si tiene conto che il gradiente medio di temperatura al gran sasso, calcolato in base ai dati di tonini (1961) é di circa 0,6°c per ogni 100 m, si può ipotizzare che, a parità di precipitazioni, la temperatura media annua attuale superi di almeno 1,1°c quella del periodo più freddo della piccola età glaciale. la differenza tra ela delle espansioni glaciali precedenti e quella attuale, implicano che nel corso di fasi particolarmente fredde del periodo vii ÷ iii/ii secolo bc la temperatura media annua doveva essere inferiore di almeno 0,8°c, e nel corso dell'espansione glaciale precedente al x secolo doveva essere inferiore di almeno 0,9°c rispetto all'attuale. ccoonncclluussiioonnee lo studio di detriti di origine glaciale posti a ridosso o appena a valle della soglia del circo del ghiacciaio del calderone, ha fornito elementi per l'inquadramento cronologico di alcune fasi di espansione glaciale avvenute nel corso degli ultimi 3000 anni. la cronologia di tali fasi appare ben correlabile con quella delle avanzate dei ghiacciai alpini. l'esame di altri dati di carattere paleoclimatico relativi all'italia centrale ha permesso di validare i dati rilevati e di ottenere una più precisa datazione delle avanzate glaciali. il confronto tra le variazioni di ela rispetto all'attuale ha permesso di valutare anche lo scostamento delle temperature medie rispetto al giorno d'oggi. un'espansione glaciale, databile tra i secoli vii e iii÷ii bc, ha dato luogo alle morene dello stadio calderone 2; nel corso delle fasi più fredde, la temperatura media annuale doveva essere almeno 0,8°c inferiore all'attuale. una successiva espansione glaciale, databile tra il vii ed il x secolo ad, ha dato luogo alle morene dello stadio calderone 3a; nel corso delle fasi più fredde, la temperatura media annuale doveva essere almeno 0,9°c inferiore all'attuale. un'ulteriore espansione glaciale, la più estesa, databile tra xvi e parte del xix secolo ad, quindi attribuibile alla cosiddetta piccola età glaciale, ha dato luogo alle morene dello stadio calderone 3b; nel corso delle fasi più fredde, la temperatura media annuale doveva essere almeno 1,1°c inferiore all'attuale. l'ultima espansione glaciale, databile al xix secolo e quindi alla parte finale della piccola età glaciale, ha prodotto le morene presenti non lontano dalla posizione del fronte glaciale documentato verso la fine del xix secolo; nel corso delle fasi più fredde, la temperatura media annua doveva essere almeno 0,9°c inferiore all'attuale. nei periodi compresi tra le espansioni glaciali, vi erano fasi caratterizzate da clima più caldo; per queste non é possibile calcolare ela (e quindi la differenza di temperatura rispetto all'attuale) a causa della mancanza delle tracce glaciali, asportate dalle avanzate successive. tuttavia é possibile parlare di contrazione dei ghiacciai per il periodo successivo ai secoli iii÷ii bc e precedente al vii secolo ad, per quello che va almeno dal secolo xi al xiii ad e infine per il periodo successivo al xix secolo ad. rriinnggrraazziiaammeennttii lavoro eseguito con il contributo dell'ente parco nazionale del gran sasso e monti della laga. rriiffeerriimmeennttii bbiibblliiooggrraaffiiccii baroni c. (2000) il comportamento dei ghiacciai alpini in risposta alle variazioni climatiche oloceniche. in: antonioli et al. : le fluttuazioni del clima nel corso dell'olocene: stato dell'arte. il quaternario, 1133(1), 100-103. baroni c. & carton a. (1991) vedretta di pisgrana (gruppo dell'adamello). geomorfologia e variazioni oloceniche della fronte. natura bresciana, ann.museo civ. sc. nat. brescia, 2266. d'orefice m., le donne l., pecci m., smiraglia c. & ventura r. (1996) nuovi dati sull'alimentazione nevosa del ghiacciaio del calderone (gran sasso d'italia, appennino centrale). geogr.fis. din. quat., 1188, 253-256. federici p. r. (1979). una ipotesi di cronologia glaciale würmiana, tardo e post-würmiana nell'appennino centrale. geogr. fis. dinam. quat., 22, 196-202. fiucci a., gigante b., rossi c., smiraglia c. & veggetti o. (1997) the calderone glacier (gran sasso d'italia). determination of ice thickness and bedrock morphology by means of radio-echo sounding. geogr. fis. dinam. quat., 2200, 305-308. gambini e. (1995) le oscillazioni di livello del lago trasimeno. quaderni del museo della pesca del lago trasimeno-2, 139 pp. gambini e. (2000) i vil laggi sommersi del lago trasimeno. quaderni del museo della pesca del lago trasimeno-5, 117pp. gellatly a.f., grove j.m. & smiraglia c. (1992) alcuni risultati di recenti ricerche sul ghiacciaio del calderone (gran sasso d'italia, abruzzo). geogr. fis. din. quat., 1155, 111-113. gellatly a.f., smiraglia c., grove j.m. and latham r. (1994). recent variations of ghiacciaio del 154 c. giraudi calderone, abruzzi, italy. journal of glaciology. 4400, 486-490. giraudi c. (1998) late pleistocene and holocene lake level variations in fucino lake (abruzzo central italy) inferred from geological, archaeological and historical data. esf workshop "palaeohydrology as reflected in lake-level changes as climatic evidence for holocene times". palaoklimaforschung, 2255, 1-17. gustav fisher verlag ed. giraudi c. (2000) le oscillazioni oloceniche del ghiacciaio del calderone, gran sasso d'italia (abruzzoitalia). il quaternario, 1133(1/2), 31-38. jaurand e. (1994). les heritages glaciaire de l'apennin. thèse pour le doctorat dès lettres de l'université de paris i panthéon-sorbonne. 600 pp. marinelli o. & ricci l. (1916) alcune osservazioni sul ghiacciaio del gran sasso. riv. geogr. it., 2233, 399-405. matthews j.a. (1993) radicarbon dating of buried soils with particular reference to holocene solifluction. in: solif luction and climatic variation in the holocene. palaoklimaforschung-palaeoclimate research. special issue: european palaeoclimate and man-6. 1111, 309-324. orombelli g. & pelfini m. (1985) una fase di avanzata glaciale nell'olocene superiore, precedente alla piccola glaciazione, nelle alpi centrali. rend.soc.geol.it., 88, 17-20. orombelli g. & porter s.c. (1982) late holocene fluctuations of brenva glacier. geogr.fis.dinam.quat. 55, 13-37. smiraglia c. & veggetti 0. (1991) il ghiacciaio del calderone nel gran sasso d'italia. variazioni recenti e relazioni col clima. atti convegno "le variazioni recenti del clima (1800-1900) e le prospettive per il xxi secolo. mem.soc. geogr. it., 4466, 183-198. smiraglia c. & veggetti 0. (1992) recenti osservazioni sul ghiacciaio del calderone (gran sasso d'italiaabruzzo). boll. soc. geogr. it., ser.xi,44, 269-302. strumia g. (1997) oscillazioni glaciali precedenti la piccola età glaciale documentate da un suolo sepolto in una morena del ghiacciaio del lys. il quaternario, 1100(2), 153-158. tonini d. (1961). il ghiacciaio del calderone del gran sasso d'ital ia. bollett ino del comitato glaciologico italiano 1100, 71-134. ms. ricevuto il 3 gennaio 2002 testo definitivo ricevuto il 26 febbraio 2002 ms. received: junuary 3, 2002 final text received: february 26, 2002 imp.bottari& evidenze dell’antico portus pelori da analisi paleotopografiche della penisola di capo peloro (sicilia nord-orientale) antonio bottari 1, carla bottari 2 & pietro carveni 3 1 osservatorio sismologico università di messina, via osservatorio 4, 98121 messina, italia, fax +39090363533, e-mail bottari@unime.it 2 istituto nazionale di geofisica e vulcanologia, via di vigna murata 605, 00143 roma, italia, fax +390651860507, e-mail bottari@ingv.it 3 dipartimento di scienze geologiche, università di catania, corso italia 57, 95129 catania, fax +39095412646,e-mail carveni@unict.it riassunto: bottari a., bottari c. & carveni p., evidenze dell’antico portus pelori da analisi paleotopografiche della penisola di capo peloro (sicilia nord-orientale). (it issn 0394-3556, 2006). il peloro, geograficamente la più orientale propaggine della sicilia settentrionale, identificabile con la penisola di capo peloro, in età greca e romana era un’area antropizzata che si era sviluppata intorno al primo insediamento umano conosciuto della sponda siciliana dello stretto di messina (2200 – 2000 a.c.). fonti storiche diverse menzionano che già dal v secolo a.c. grandi flotte di navi sia siracusane sia puniche approdavano al peloro e vi sostavano anche per lunghi periodi. rilevato che la morfologia attuale della penisola di capo peloro non presenta alcuna insenatura protetta dalle traversie del mare e capace di offrire riparo a flotte di centinaia di navi, si sono svolte indagini geomorfologiche al fine di accertare se quanto storicamente documentato sia compatibile con una paleotopografia dei luoghi. l’approccio adottato si basa sull’analisi delle caratteristiche morfotettoniche dell’area del peloro e specificatamente della evoluzione morfotettonica della sua pianura costiera, a seguito del sollevamento regionale che l’ha interessata nel quaternario e, particolarmente, durante gli ultimi 0,7 ma. la configurazione dello stretto di messina rappresenta infatti il risultato di un elevata mobilità verticale e del progressivo sollevamento che hanno interessato aree di sedimentazione corrispondenti ad un sistema complesso di fosse tettoniche controllate da faglie normali a prevalente direzione ne-sw ed e-w. i dati della letteratura geologica, unitamente a ritrovamenti di resti architettonici monumentali, nonché alcuni riscontri con fonti storiografiche, supportano per gli ultimi 2500 anni una stima del sollevamento della penisola di capo peloro di ~ 1,7 metri. le modellazioni della paleotopografia della pianura costiera, riferibili al v secolo a.c., configurano una maggiore estensione del pantano piccolo e, particolarmente, il suo collegamento con il mare tirreno, attraverso un canale largo un centinaio di metri. tale risultato induce a localizzare l’antico porto del peloro nel bacino del pantano piccolo che per estensione poteva ospita-re sino a 320 navi trireme. una tale collocazione, a poco meno di un miglio marino da capo peloro, giustifica il comune riferimento al peloro, trova riscontro nelle distanze, sia terrestri sia marittime, dalla polis di messana (oggi messina) riportate da differenti fonti storiche e, per la sua minore distanza dagli approdi di skillayon e columna in calabria, risulta anche compatibile con l’appellativo di trajectus. abstract: : bottari a., bottari c. & carveni p., paleotopographic analysis of peloro cape peninsula: evidence of the ancient portus pelori (ne sicily, italy). (it issn 0394-3556, 2006). from the archaic to the late roman period the name “peloro” was used to indicate an anthropic area developed around the first known human settlement on the sicilian shore of the straits of messina. it was geographically the most eastern tip of north sicily and today it is identified with the peloro cape peninsula. such a settlement has been dated to 2200 ÷ 2000 b.c. through recoveries of ceramic fragments. different historical sources mention that at the 5th century b.c. numerous syracuse and carthaginian naval armadas landed for long periods at peloro. given that at present day the morphology of peloro cape peninsula does not have any protected shelter to offer repair to hundreds of naval ships as documented by historians, geomorphologic surveys have been carried out in the area to verify whether historical documents are consistent with the paleotopography of the study area. the approach is based on the analysis of the morphotectonic characteristics of the peloro and specifically on the morphotectonic evolution of its coastal lowland, following the regional uplift that has interested it during the quaternary and particularly in the last 0.7 myr. the straits of messina configuration is the result of a progressive uplift that interested the sedimentation areas correspondent to a complex system of tectonic grabens controlled by ne-sw and e-w normal faults. the geological data together with the uncovered remains of ancient buildings and the shells of present day molluscs found in the study area, as well as some comparison with historiographical sources, support that the uplift of peloro cape peninsula is of about 1.5 ÷ 2.0 metres in the last 2500 years. the modelling of the paleotopography of the coastal lowland, referred to the 5th century b.c., shows a major extension of the pantano piccolo and particularly its connection with the tyrrhenian sea through a canal hundreds of metres wide. such a result induces as to locate the ancient peloro harbour in the basin of the pantano piccolo, which for extension and depth could have sheltered up to 320 ships. such a location of the ancient harbour at about one nautical mile from peloro cape is also supported by different historical sources which report the distances from the polis of messana (the present day messina) and justifies also the appellative of “portus pelori” (peloro harbour). parole chiave: geoarcheologia, sollevamento tettonico, penisola di capo peloro, pantano piccolo, portus pelori, modellazione paleotopografica. keywords: geoarchaeology, tectonic uplift, peloro cape peninsula, ancient peloro harbour, pantano piccolo salt marsh, paleotopography modelling. il quaternario italian journal of quaternary sciences 19(1), 2006 167-174 168 a. bottari, c. bottati & p. carveni 1. introduzione la penisola del peloro, estremo lembo nordorientale della sicilia, in epoca greca e romana è stata teatro di vicende belliche e snodo di importanti traffici marittimi che hanno segnato la storia di messana, l’attuale messina (fig. 1). tuttavia, in tale ambito, taluni avvenimenti pongono interrogativi, tuttora non ancora risolti, principalmente per la difficoltà di individuare con precisione la collocazione geografica di un importante porto menzionato da varie fonti storiche. alcuni studiosi contemporanei, quali aricò (1999) e prestianni giallombardo (2002 a; 2002 b), hanno ipotizzato che dette difficoltà derivino dalle mutate condizioni della superficie topografica della penisola peloritana e che, pertanto, un’analisi dell’evoluzione geomorfologia recente di questa parte del territorio siciliano potrebbe fornire elementi utili per superare le attuali incertezze. nell’ambito di tali problematiche rientra l’ubicazione dell’antico portus pelori che, nel v secolo a.c., ospitava intere flotte navali, sia cartaginesi sia siracusane, e che nel iii secolo a.c., durante la i guerra punica, offrì riparo alla flotta romana che rientrava da cartagine. la difficoltà origina dalla circostanza che, al presente, lungo le attuali rive della penisola del peloro non c’è traccia di una baia che possa essere stata utilizzata per l’ormeggio delle antiche navi. scopo del presente lavoro è pertanto quello di verificare se, tenendo conto dell’evoluzione morfotettonica recente della penisola del peloro, la paleotopografia riferibile al v secolo a.c. sia compatibile con l’esistenza di un approdo. 2. brevi note sulle aree lagunari del peloro e di messana il territorio dell’antica messana, l’odierna messina, si estendeva dalla zona falcata a sud, contigua alla polis, sino al capo peloro a nord (fig. 2). gli estremi di tale territorio erano caratterizzati dai terreni pianeggianti, sabbiosi ed a tratti lagunari, della pianura costiera che orlava i versanti ionico e tirrenico dei monti peloritani. l’estensione dell’attuale area lagunare del peloro risulta alquanto ridotta rispetto a quella antica, presentando due soli bacini salmastri, denominati pantano piccolo (o laguna di faro) e pantano grande (o laguna di ganzirri) (fig. 1). infatti, nell’area di margi, sita tra detti pantani, si trovava sicuramente una laguna oggi non più esistente o forse altre due (solino, iii d.c.). a differenza del pantano grande, di forma allungata e con acque poco profonde ( massimo 6,5 metri) il pantano piccolo ha forma circa circolare ed acque profonde sino a 29 m (abbruzzese & genovese, 1952). recenti lavori di restauro del settore occidentale della cinta bastionata della medioevale torre peloro, sita sulla costa tirrenica del capo peloro (f in fig. 3), hanno condotto al ritrovamento di alcune strutture architettoniche, in via preliminare ascritte ad età romana, parzialmente celate dalle mura della cinta (bacci, 2001; prestianni giallombardo, 2002 b). trattasi di un’ampia platea sulla quale poggia un lungo tratto di podio gradinato in calcestruzzo, con rivestimento in laterizio e copertura di malta idraulica. in atto, il livello del piano d’imposta di detta struttura si trova a poco meno di 1 metro s.l.m.m. ad oggi, pur in mancanza di figura 1 foto aerea della penisola di capo peloro (ne sicilia), riproducente i bacini salmastri di pantano piccolo (pp) e di pantano grande (pg). evidente la notevole urbanizzazione dell’area del peloro e, per la trasparenza delle acque, il fondo poco profondo (1 ÷ 3 m) del settore occidentale del bacino del pp. satellite picture of peloro cape peninsula with the location of the salt marsh basins of pantano piccolo (pp) and pantano grande (pg). the high numbers of houses in the area of peloro testifies the high urbanization, while the transparency of the waters point out shallow deep waters (1÷3) in the western sector of the basin pp. un’analisi archeologica che consenta il riconoscimento certo della funzione originaria della struttura venuta alla luce, la sua ubicazione a poche decine di metri dalla riva del mar tirreno, il livello d’imposta prossimo a quello del mare e l’impiego di malta idraulica inducono a ritenere che possa trattarsi di una struttura di collegamento con il mare, forse per l’alaggio delle navi. la zona lagunare interna alla penisola (detta la falce, s in fig.2) che conforma il porto di messina era contigua all’antica polis di messana, e dall’inizio del secolo scorso non esiste più a seguito di vari lavori di prosciugamento effettuati nel tempo (prestianni giallombardo, 2002 a). un' importante testimonianza di rapide variazioni del l ivello del mare avvenute nell'olocene è data da bonfiglio et al. (1994) e da bonfiglio (1999): gli autori, analizzando i risultati di alcuni carotaggi eseguiti circa 150 metri a meridione del porto di messina (c in fig. 2), hanno rilevato una serie di depositi olocenici poggianti in discordanza su conglomerati medio-pleistocenici; l'analisi dei depositi olocenici ha evidenziato un improvviso approfondimento di circa 20 metri del mare, cui ha fatto seguito una parziale chiusura del bacino di sedimentazione, seguita da una completa emersione della zona; la brusca sovrapposizione dei depositi marini olocenici su quelli medio-pleistocenici e il rapido approfondimento dei fondali testimoniano un rapido abbassamento di origine tettonica, cui ha fatto seguito un sollevamento dell'area in solido con l'intera dorsale peloritana. questo ultimo episodio è documentato, oltre che dalla diminuzione verso l’alto della profondità dell’ambiente di sedimentazione, dall’attuale livello della sommità dei sedimenti di ambiente marino profondo, che ora è a circa -10 metri rispetto al l.m.m. tale posizione documenta che la diminuzione della profondità osservata nella serie non è esclusivamente attribuibile al riempimento del bacino per l’apporto dei detriti, ma anche ad un sollevamento tettonico di circa 15 metri. può dedursi che anticamente la linea di costa meridionale all’interno del porto era posizionata circa 150 metri più a sud dell’attuale e che, ancora prima, durante il neolitico, il mare occupava aree più estese verso sud (bonfiglio et al., 1994). quanto rilevato, particolarmente circa l’ubicazione di aree lagunari sia al peloro sia nella zona del porto di messana, indica un minor livello della pianura costiera rispetto all’attuale. ciò è congruente con il generale sollevamento della catena e, localmente, con la subsiden169evidenze dell’antico portus pelori ... za conseguente lo slip delle faglie normali orientate circa parallelamente alla linea di costa (nne-ssw a messina; ene-wsw, wnw-ese al peloro; fig. 3). il complesso delle osservazioni, evidenziando alcuni caratteri dell’evoluzione geomorfologica recente delle aree litoranee di messina, induce a ritenere che anticamente la topografia delle medesime sia stata apprezzabilmente differente dall’attuale. 3. cenni storici diodoro, storico del i secolo a.c., riferisce che nel 396 a.c. una flotta cartaginese di 600 navi approdò al peloro da dove un contingente di 200 navi proseguì alla volta del porto di messana, noto per la sua tipica forma a falce, per cogliere di sorpresa gli abitanti della polis. inoltre, polibio (in walbank, 1957) e lo stesso diodoro menzionano che durante la prima guerra punica (264 a.c.) i romani, schieratisi in aiuto dei mamertini di messina contro i cartaginesi, ripararono circa 300 navi che rientravano da cartagine in un porto sito nei pressi di capo peloro. ancora, fonti storiche successive, quali gli itineraria di età imperiale, registrano che dell’ingente figura 2 mappa schematica del territorio a nord dell’antica messana, il porto detto la falce (s), nonché i percorsi terrestri e marittimi da/per il portus tragecynus/trajectus ubicati al peloro. c indica l’ubicazione dei sondaggi geognostici eseguiti a sud della banchina meridionale del porto di messina. map of the northern territory of messana (today messina) showing the harbour named sickle (s) and sea ways and road ways from/for the portus tragecynus / trajectus placed at peloro. the letter c indicates the geognostic borings carried out to south of messina harbour quay. 170 traffico di merci ed uomini da e per messana una parte cospicua non transitava dal porto interno alla polis, denominato la falce (s in fig. 2), bensì da un port(us) tragecynus (columba, 1906) ubicato al peloro. detto port(us) tragecynus, richiamato nella tabula peutingeriana può essere riferito al trajectus menzionato nell’itinerarium antonini poiché la distanza da messana, riportata da entrambe le fonti (uggeri, 1968; uggeri, 1997-1998; prestianni giallombardo, 2002 a) è la stessa: 12000 passus ~ 17,76 chilometri. nell’itinerarium maritimum (cannavò, 1982) esso è invece localizzato a 70 stadi, ossia a ~ 13,7 chilometri da messana. tali distanze, considerate sia come percorsi terrestri sia marittimi, individuano un tratto di costa tirrenica della penisola di capo peloro, compreso tra le odierne località di mortelle e torre bianca, distanti fra loro ~ 3 chilometri (fig. 2). oggi, in corrispondenza della pianura costiera che orla la penisola di capo peloro non vi sono tracce né di un porto né di una insenatura capace di offrire un sicuro riparo al naviglio di quel tempo. pertanto, in mancanza di una descrizione accurata degli antichi luoghi o di resti comprovanti l’esistenza di un’antica statio navalis al peloro, si è presa in considerazione l’ipotesi di aricò (1999) che suppone il bacino del lago di faro (fig. 1), reso comunicante con il mare tramite un canale artificiale, sia stata la sede dell’antico porto menzionato dalle varie fonti storiche sopra citate. muovendo dalle incertezze derivanti dalla incompletezza dei riferimenti storiografici si sono pertanto avviate indagini in loco e si è analizzata l’evoluzione geomorfologica più recente della costa peloritana, nel contesto della tettonica attiva dell’area dello stretto di messina, al fine di verificare se dette incertezze possano essere rimosse in base ad analisi morfotettonica. 4. caratteristiche geologiche e morfotettoniche della pianura costiera di capo peloro la penisola di capo peloro, zona delle nostre indagini, è ubicata sulla sponda occidentale dello stretto di messina. la formazione geologica geometricamente più profonda affiorante nella zona dello stretto è data da metamorfiti d’alto grado premesozoiche, trasportate in falda durante il miocene e formanti la parte alta delle unità dell’aspromonte (lentini et al., 2000); immediatamente sopra alle citate metamorfiti giace un conglomerato poligenico sterile, composto prevalentemente da ciottoli provenienti dalle sottostanti metamorfiti; detto figura 3 mappa geologica della penisola di capo peloro. pp: pantano piccolo; pg: pantano grande; g: faglia di ganzirri; h: faglia di faro; i: faglia di mortelle; f: torre peloro. geological map of the peloro cape peninsula. pp: pantano piccolo; pg: pantano grande; g: ganzirri fault; h: faro fault; i: mortelle fault; f: ancient tower. a. bottari, c. bottati & p. carveni 171 conglomerato evolve verso l’alto ad un’alternanza arenaceo-marnosa di età tortoniana (jacobacci et al., 1961). in continuità di sedimentazione sui termini tortoniani si trovano limitati lembi della serie gessoso-solfifera siciliana di età messiniana, composti da marne tripolacee, calcare brecciato e gessi (jacobacci et al., 1961). in trasgressione sui depositi messiniani giacciono marne bianche a globigerine infraplioceniche (trubi) (jacobacci et al., 1961), cui fanno seguito, sempre in trasgressione, calcareniti del pleistocene inferiore (lombardo 1980 a; 1980 b), su cui poggiano le argille di vito superiore di età infra-pleistocenica. su tutte le formazioni descritte poggiano in discordanza le ghiaie medio-pleistoceniche della formazione di messina cui fanno seguito depositi terrazzati continentali (lombardo 1980 a; 1980 b), alluvioni recenti, alluvioni e depositi di spiaggia attuali. la penisola di capo peloro può essere suddivisa in due parti: la zona collinare e la spianata alluvionale; la serie stratigrafica affiorante è costituita alla base da rocce cristalline, su cui poggiano i termini della serie tortoniana e le ghiaie della formazione di messina; la spianata alluvionale è formata da depositi alluvionali recenti ed attuali. l’attuale configurazione dello stretto di messina è il risultato di un’elevata mobilità verticale e di un progressivo sollevamento che hanno interessato aree di sedimentazione interne a fosse tettoniche controllate da faglie normali orientate prevalentemente nne-ssw, ne-sw e circa e-w. focalizzando l’attenzione sulla sponda siciliana dello stretto, le indagini sono state rivolte ai terreni della penisola di capo peloro, mediante l’analisi fotogeologica e la ricerca di elementi morfologici indicativi dell’attività di faglie durante il pleistocene e l’olocene. questa fase delle indagini ha condotto a riconoscere nelle faglie di mortelle, pantano piccolo e granatari (fig. 3) strutture la cui attivazione è avvenuta in tempi recenti (ghisetti, 1992; bottari et al., 2005 a: 2005 b). tali risultati sono congruenti con quelli di campagne di rilievi geofisici (del ben, 1985; finetti & del ben, 1985), di analisi della paleosismicità (valensise & pantosti, 1993), di deformazioni avvenute in seguito del terremoto calabro-messinese del 1908 (lo perfido, 1909; baratta, 1910) e di analisi dei meccanismi focali (caccamo et al., 1996; neri et al., 1996; frepoli & amato, 2000). l’attività di dette faglie, delimitando a monte la pianura della penisola di capo peloro, riduce localmente il sollevamento regionale che interessa l’area in studio da ~ 0,7 ma ( montenat et al., 1987; westaway, 1993). sulla sponda siciliana dello stretto di messina, un profilo eseguito da torre faro a monte ciccia, mostra superfici suborizzontali di abrasione, derivate da terrazzi marini, le quali indicano una velocità di sollevamento di ~ 1 mm/a (westaway, 1993). localmente è stato rilevato lo strombus bubonius non più in alto di 85 metri s.l.m. (bonfiglio & violanti, 1983), quota compatibile con un tasso di sollevamento di ~ 0,65 mm/a (~ 85 m/ 130 ka). inoltre, questa costa, bordata da faglie normali, presenta numerose faglie en échelon, ciascuna con una velocità di slip verticale di ~ 0,1 ÷ 0,2 mm/a (ghisetti, 1992). discende che il sollevamente varia apprezzabilmente da sito a sito. westaway (1993) valuta in ~ 0,9 mm/a la componente regionale del sollevamento, con variazioni locali per gli effetti della fagliazione normale > ~ 0,2 mm/a . pertanto, assumendo per la velocità del sollevamento regionale della sponda siciliana dello stretto il valore di 0,9 mm/a, corretto localmente per velocità di slip verticale di 0,2 mm/a, si ottiene per gli ultimi 2500 anni un sollevamento di 1,75 metri. adottando il dato di bonfiglio & violanti (1983) si ottiene un valore di poco inferiore, pari a 1,625 metri. in letteratura, il dato più recente sul tasso del sollevamento dell’area peloro ganzirri, determinato con mis 5,5, è di 704 mm/ka (antonioli et al., 2005), che in 2500 anni significa un sollevamento di 1,76 metri. pertanto, sulla base dei valori della letteratura, si può assumere che negli ultimi 2500 anni il sollevamento dell’area del peloro sia stato di ~1,70 metri. concludendo, l’analisi della morfotettonica dell’area del peloro mette in evidenza come l’attuale configurazione della zona in studio rappresenti il risultato di un’elevata mobilità verticale e di un progressivo sollevamento, localmente ridotto dallo slip di alcune faglie normali. rilevato ancora che in atto alcuni settori della pianura del peloro mostrano quote < 1 m s.l.m., si è orientato il proseguimento dell’indagine verso la ricostruzione dell’antica configurazione dei luoghi. 5. modellazione della paleotopografia della penisola di capo peloro per tutto quanto sopra richiamato, ed allo scopo di verificare se la ricostruzione dell’antica topografia della pianura del peloro possa dare indicazioni circa l’esistenza di un’antica baia, sufficientemente capiente e ben protetta dalle traversie del mare, o comunque fornire elementi a supporto dell’ipotesi di aricò (1999), che il porto antico del peloro fosse allocato nel bacino del pantano piccolo, si sono eseguite modellazioni digitali della superficie topografica adottando il software arcview, applicate alle quote derivate da immagini da satellite rilevate nel 2001 (regione siciliana). dette quote hanno incertezza assoluta dell’ordine di 10 cm ed incertezza relativa dell’ordine del centimetro. la modellazione opera sulle quote di punti del piano campagna aventi interdistanza media di 50 metri. la ricostruzione della paleotopografia della piana costiera è stata eseguita tramite digitalizzazione della carta topografica, previo filtraggio delle quote, al fine di eliminare le maggiori alterazioni topografiche operate dall’uomo, a seguito della realizzazione di artefatti vari (edifici, rilevati in terra, strade rialzate, canali, ecc.). essa tiene conto del sollevamento tettonico, simulando un equivalente abbassamento del livello medio del mare, rispetto alla terra ferma, con un tasso medio di 704 mm/ka. la zona di margi, che in atto presenta anch’essa quote del piano di campagna inferiori a un metro, è stata tuttavia esclusa dalla fase del filtraggio e dalle successive modellazioni, in considerazione delle alterazioni subite dalla superficie naturale del terreno originario a seguito dei lavori di bonifica delle saline eseguiti nella prima metà del xix secolo. tali alterazioni non possono essere filtrate poiché non si dispone di evidenze dell’antico portus pelori ... 172 una accurata documentazione che consenta di distinguere l’antico andamento della superficie topografica sulla quale è stato riversato il materiale alluvionale utilizzato per prosciugare le antiche saline. la simulazione si basa sull’assunzione che 2500 anni addietro, assumendo un tasso medio di sollevamento di 704 mm/ka, il livello medio del mare fosse 1,70 metri più elevato rispetto alla costa considerata fissa, e che pertanto le zone della pianura costiera con altitudine attuale inferiore a 1,7 metri fossero a quel tempo sommerse. consegue che a quel tempo la profondità delle acque del bacino di faro era in eguale misura maggiore dell’attuale. le modellazioni eseguite sono rappresentate nella figura. 4, ove le mappe b e c rappresentano le topografie riferibili, rispettivamente, al v secolo a.c. (∆h = + 1,70 metri) ed al iii secolo d.c. (∆h = + 1,25 metri). in complesso le modellazioni mostrano modeste variazioni delle geometrie della linea di costa, un’apprezzabile quanto prevedibile suo arretramento rispetto alle acque del tirreno ed il conformarsi di una apertura (canale) nei depositi di spiaggia in corrispondenza di torre bianca, che rende comunicanti le acque del mare tirreno con quelle del pantano piccolo. per ∆h = + 1,7 metri tale canale ha una larghezza minima di 120 metri ed una profondità di circa 1 metro; la superficie del bacino risulta più grande dell’attuale, estendendosi prevalentemente verso oriente e ssw (margi). tuttavia, nelle due mappe (fig. 4: b e c), la paleotopografia dell’area di margi non è rappresentata per i motivi sopra richiamati. in sintesi, le variazioni topografiche più importanti, evidenziate tramite le modellazioni eseguite, risultano nell’apertura di un canale sulla costa tirrenica che mette in comunicazione le acque del bacino di pantano piccolo con quelle del mare, una maggiore grandezza dello specchio d’acqua lacustre che porta a 230.000 metri quadrati l’estensione del bacino ove le acque hanno profondità ≥ 3,0 metri. figura 4 modellazioni della superficie topografica della penisola di capo peloro: a) attuale; b) simulando una variazione del livello del mare ∆h = + 1,25 m; c) simulando una variazione del livello del mare ∆h = + 1,70 m. modelling of the topographical surface of peloro cape peninsula: a) present day topographical surface; b) and c) reconstructions of topographical surface with ∆h variations of sea level of +1.00 and +1.70 m, respectively. 6. considerazioni conclusive i risultati delle modellazioni paleotopografiche della pianura costiera del peloro supportano che: a. bottari, c. bottati & p. carveni a) nel v sec. a.c. le acque del pantano piccolo erano comunicanti con quelle del tirreno attraverso un canale naturale largo ~120 metri e profondo ~ 1 metro; il bacino lacustre costituiva così un approdo naturale, ben riparato dalle traversie marine, esteso oltre 300.000 metri quadrati e per ~ il 70% con acque profonde ≥ 3 metri; in tali condizioni esso era però accessibile solo alle piccole navi; diversamente, mediante lavori di dragaggio del canale di accesso, in modo da realizzare una profondità delle acque di almeno 2,5 ÷ 3,0 metri, il bacino diveniva accessibile anche al naviglio maggiore; infatti, sia le trireme del iii secolo a.c., sia le navi da guerra di età augustea, erano lunghe non più di 36 metri, larghe da 5 a 6 metri e con pescaggi non maggiori di 1,5 metri (höckmann, 1988); ne consegue che con un modesto dragaggio del fondo del canale, il bacino poteva ospitare sino a 320 trireme. le navi commerciali, tranne le più grandi navi frumentariae, erano più corte delle trireme, in proporzione più larghe ed, al pari delle navi da guerra, avevano il profilo trasversale della carena relativamente piatto, con pescaggi generalmente non superiori a 2 metri (foley et al., 1982; white, 1984); b) dal vi secolo a.c. le darsene per il ricovero delle navi erano diffuse in grecia, in italia e nell’area fenicio-punica. i greci avevano buona esperienza di scavi per la realizzazione di canali navigabili e per gli ingegneri romani l’apertura di canali per la realizzazione di strutture portuali era lavoro di routine (blackmann, 1982; höckmann, 1988). dragare le sabbie del canale di accesso al pantano piccolo, su un fronte di una ventina di metri, per portare i fondali da -1 a -3 metri, era pertanto tecnicamente fattibile ed economicamente e militarmente conveniente, perché garantiva l’agibilità di un porto sufficientemente ampio da potere ospitare centinaia di navi. inoltre, ciò rendeva possibile salpare/approdare in un tratto di mare che, in quanto esterno rispetto all’imboccatura settentrionale dello stretto, non risentiva delle forti correnti di marea (fino a 7 nodi di velocità) tipiche dello stretto di messina (montenat et al., 1987). per le navi di quel tempo le correnti dello stretto costituivano una seria difficoltà, e pertanto una statio navalis molto prossima al peloro, ma esterna alle acque dello stretto, era sicuramente preferibile al porto della falce di messina quando il traffico di uomini e/o merci era verso/da gli approdi del mediterraneo centro-occidentale; c) la breve distanza di un porto al peloro dagli approdi più vicini della calabria (4,5 chilometri da skyllaion, ora scilla, e 3,8 chilometri da columna) risultando minori delle distanze del porto della falce di messina sia da skyllaion, sia da columna sia da reghium (l’attuale reggio calabria), era il percorso più breve verso/dalla penisola italica. ciò giustifica il termine trajectus menzionato nell’itinerarium antonimi per indicare l’approdo del peloro. in conclusione, per tutto quanto sopra considerato, la ricostruzione della paleotopografia della penisola di capo peloro riferibile al v secolo a.c. indica che essa era compatibile con un approdo conformato dal bacino del pantano piccolo comunicante con il mare tirreno. tale approdo, inoltre, avendo l’accesso distante meno di 1 miglio nautico dal capo peloro, giustifica il comune riferimento al peloro delle fonti storiche in relazione all’ubicazione sia del port(us) tragecynus, sia del trajectus, sia della statio navalis. ricerca eseguita con il contributo del m.i.u.r. nell’ambito della ricerca morfodinamica di zone costiere sismicamente attive (responsabile pietro carveni). ringraziamenti si ringrazia vivamente l’ing. salvatore guarniere che ha collaborato alle elaborazioni gis per la modellazione della paleotopografia. testi citati abruzzese d. & genovese s. (1952) osservazioni geomorfologiche e fisico-chimiche sui laghi di ganzirri e di faro. boll. pesca, piscicoltura e idrobiologia, anno xxvii, 7 (1), 3-20. antonioli f., kershaw s., renda p., rust d., belluomini g., cesaroli m., radete u. & silenzi, s. (2005) elevation of the last interglacial highstand in sicily (italy): a benchmark of coastal tectonics . quaternary international, 145-146, 3-18. aricò n. (1999) illimite peloro. interpretazioni del confine terracqueo. edizioni mesogea, messina, pp. 18. bacci g.m. (2001) indagini archeologiche a capo peloro, rassegna internazionale di archelogia subacquea, giardini-naxos, 12-14 ottobre 2001. baratta m. (1910) la catastrofe sismica calabro-messinese (28 dicembre 1908). relazione alla società geografica italiana, roma, pp. 286. blackman d.j. (1982) ancient harbours in the mediterranean . intern. journ. nautical archaeology, 11, pp. 79. bonfiglio l. (1999) la distribuzione dei siti archeologici, il contesto stratigrafico e la ricostruzione paleoambientale, in da zancle a messina, un percorso archeologico attraverso gli scavi, regione siciliana, assessorato dei beni culturali ed ambientali e della pubblica istruzione, palermo, pp. 9-17. bonfiglio l., bacci m.g. barra d., bonaduce g., di geronimo i., mandra l., proposito a. & violanti d. (1994) paleoecological, radiometric and archaeological core analysis of holocene deposits in the messina harbour area (north-eastern sicily), in matteucci et al. (eds.): studies on ecology and palaeoecology of benthic communities, boll. soc. paleont. it., vol. spec. 2, 47-60. bonfiglio l. & violanti d. (1983) prima segnalazione di tirreniano ed evoluzione pleistocenica di capo peloro (sicilia nord-orientale). geogr. fis. dinam. quat., 6, 3-15. bottari a., bottari c. & carveni p. (2005 b) tectonic genesis of the salt marshes on the sicilian coast of the straits of messina (sicily). il quaternario, 18 (2), 113-122. bottari a., bottari c., carveni p., giacobbe s. & spano n. (2005 a) genesis and geomorphological and ecological evolution of the ganzirri salt marsh (messina, italy). quaternary international, 140-141, 150-158. 173evidenze dell’antico portus pelori ... caccamo d., neri g., saraò a. & wiss m. (1996) estimates of stress directions by inversion of earthquake fault-plane solution in sicily. geophys. j. int., 125, 857-868. cannavò a.r. (1982) sulla statio di partenza della via costiera orientale della sicilia romana. archivio storico per la sicilia orientale, 78, 15 – 19. columba g.m. (1906) i porti della sicilia, in monografia storica dei porti dell’antichità nell’italia insulare, i, roma, (rist. anast., palermo 1991), pp. 292. del ben a. (1985) technical report n° 85001. stretto di messina s.p.a., roma, pp. 18. finetti i. & del ben a. (1985) technical report n°850016. stretto di messina s.p.a., roma, pp. 22. foley v., södel w. & doyle j. (1982) a trireme displacement estimate . intern. jour. nautical archaeology, 11, pp. 305. frepoli a. & amato a. (2000) fault plane solutions of crustal earthquakes in southern italy (1988-1995): seismotectonic implications. ann. geofis., 43, 437-467. ghisetti f. (1992) fault parameters in the messina strait (southern italy) and relations with the seismogenetic source. tectonophysics, 210, 117133. hõckmann o. (1988) la navigazione nel mondo antico. garzanti, pp. 301. jacobacci a., malatesta a. & motta s. (1961) piano di studi sullo stretto di messina per il collegamento della sicilia con la calabria: ricerche geologiche. istituto ricerche e.s., palermo, 66 pp. lentini f., caliri a., carbone m.s., carveni p., catalano s., gargano c., grasso m., la manna f., lentini r., strazzulla s., vinci g. & vinciguerra g. (2000) carta geologica della provincia di messina. scala 1:50.000, se.l.ca., firenze. lombardo g. (1980 a) stratigrafia dei depositi pleistocenici della sicilia nord-orientale. att. acc. gioenia sc. nat., catania, 12, 84-113. lombardo g. (1980 b) studio stratigrafico del pliopleistocene del bacino di reggio calabria. att. acc. gioenia sc. nat., catania, 12, 233-298. lo perfido a. (1909) livellazione geometrica di precisione eseguita dall’i.g.m. sulla costa orientale della sicilia da catania a messina, a gesso ed a capo peloro, sulla costa occidentale della calabria da gioia tauro a melito di porto salvo, per incarico del ministro dell’agricoltura, industria e commercio. relazione alla commissione della reale accademia dei lincei, pp. 35. montenat c., barrier p. & di geronimo i. (1987) the strait of messina, past and present: a review. in le détroit de messine (italie): evolution tectono-sédimentaire récente et environnement actuel. doc. et trav. igal, paris, 11, 272 p. neri g., caccamo d., cocina o. & montalto a. (1996) geodynamic implications of earthquake data in the southern tyrrhenian sea. tectonophysics, 258, 233-249. prestianni giallombardo a.m. (2002 a) il peloro nell’antichità. miti scienze storia in messina e reggio nell’antichità: storia, società, cultura. atti convegno s.i.s.a.c., messina reggio calabria, 24-26 maggio 1999, 141-177. prestianni giallombardo a.m. (2002 b) la falce-porto di zankle-messana. dall’alto arcaismo alla tarda antichità in la penisola di san ranieri diaspora dell’origine, sicania, 4, 129-154. solino, c.j., (iii d.c.) collectanea rerum memorabilium, 5, 2. uggeri g. (1968) la terminologia portuale romana e la documentazione dell’“itinerarium antonini”. studi italiani filologia classica, vichiana, 40, 225-254. uggeri g. (1997-1998) itinerari e strade, rotte, porti e scali della sicilia tardoantica. kokalos, 43-44, 299-364. valensise g. & pantosti d. (1993) a 125 kyr-long geological record of seismic record of seismic source repeatability: the messina straits (southern italy) and 1908 earthquake (ms 7 1/2). terra nova, 4, 472-483. walbank f.w. (1957) a historical commentary on polibius, i, oxford 1957, 61-63 westaway r. (1993) quaternary uplift of southern italy. j.g.r., 98, 21.741-21.772. white k.d., 1984 greek and roman technology, pp.104. 174 ms. ricevuto il 16 maggio 2006 testo definitivo ricevuto il 3 novembre 2006 ms. received: may 16, 2006 final text received: november 3, 2006 a. bottari, c. bottati & p. carveni imp.mingione& cartografia storica e sistemi gis per lo studio dell’evoluzione dei caratteri fisici ed antropici del territorio. il caso di capua (ce) eleonora mingione1, daniela ruberti2, sandro strumia2 & marco vigliotti2 1via s. tammaro, 23 capua 2seconda università degli studi di napoli dipartimento di scienze ambientali, via vivaldi, 43 caserta. riassunto: e. mingione, d. ruberti, s. strumia & m. vigliotti, cartografia storica e sistemi gis per lo studio dell’evoluzione dei caratteri fisici ed antropici del territorio. il caso di capua (ce). it issn 0394-3356, 2004. il presente lavoro rappresenta un contributo preliminare per la ricostruzione delle dinamiche territoriali avvenute in un settore della piana campana attraversata dal fiume volturno nei dintorni di capua tramite l’uso dei sistemi informativi geografici e il confronto dei risultati di indagini parallele su tematiche storico-letterarie, cartografiche, geologico-geomorfologiche e botaniche. rappresentazioni cartografiche di tipo pre-geodetico, riferibili all’intervallo compreso tra la fine del 500 e la fine del 1700, e carte di tipo geodetico, che coprono il periodo che va dal 1800 al 1998, sono state acquisite, analizzate ed elaborate in ambiente gis. dalla sovrapposizione di tutte le carte sono stati evidenziati i maggiori cambiamenti della morfologia fluviale. per un’ulteriore verifica di queste variazioni è stato realizzato un modello digitale del terreno derivato dai rilievi aereofotogrammetrici alla scala 1:2000. tali analisi hanno evidenziato come, a macroscala, l’attuale configurazione di questo tratto del fiume sia stato condizionato dalle attività antropiche di regimentazione e di edificazione, cui si sono sovrapposti gli effetti delle variazioni naturali connesse a fattori climatici (piccola età glaciale arcaica; piccola età glaciale alto-medievale). le grosse modificazioni indotte al corso fluviale principale, infatti, trovano plausibile spiegazione in eventi alluvionali rapidi e catastrofici che si sono susseguiti nella piana, come dimostrato dal record stratigrafico locale. rilievi fisionomici-strutturali della vegetazione ripariale hanno inoltre permesso di caratterizzare le comunità vegetali presenti, fornendo utili indicazioni che sono state interpretate insieme ai dati di tipo geologico, ottenendo una migliore comprensione della qualità ambientale dell’area indagata. abstract: e. mingione, d. ruberti, s. strumia & m. vigliotti, the study of physical and antrhopic landscape evolution thriugh historical cartography and gis tools: the capua (ce) case history. it issn 0394-3356, 2004. the use of g.i.s. (geographic information systems) have been applied to reconstruct the landscape evolution of the volturno river plain in the surrounding of capua (southern italy). the study has been carried out comparing historical-bibliographic, cartographic, geologic and botanic analyses that have furnished several spatial and temporal data. the development of capua has been strongly conditioned by the presence of the volturno river since its birth during the viii-ix centuries. most of the history of the town is well documented by maps, drawings, paintings. some pre-geodetic maps have been selected in order to describe the major landscape modifications whichoccurred during the 500-1700 age interval. they have been analized and processed into a gis environment. each document has been georeferenced, rototraslated and regenerated on a referenced base map. geodetic maps refer to igmi (istituto geografico militare d’italia) topographic maps and numerical aereophotogrammetries produced by local governments. on the whole, the above mentioned documents are related to the 1800-1998 interval. the map overlay evidenced major changes of the fluvial morphology. further evidence came from a dtm (digital terrain model) created on the base of the 1:2000 numerical maps. such a detailed model highlights landscape micro-morphologies little evident on the topographic maps; this is exspecially relevant for low-relief regions such as alluvial plains. from the above derives that, on a large scale, the present river plain setting has been conditioned by the human activities of buildings and water-regulation plus the natural variation effects linked to climatic changes (arcaic little ica age; middle-age little ice age; etc.). the most important changes, infact, appear closely related to rapid and catastrophic alluvial events that repeatedly occurred in the plain, as evidenced by the local stratigraphic record. where the human impact on river dynamics is limited, the fluvial morphology is substantially unchanged. fisionomic-structural surveys on the riparian vegetation have permitted the characterization of the local plant communities; the observations have been related to the main geological results in order to characterize the studied area in terms of environmental quality. parole chiave: capua, volturno, dinamica fluviale, sistemi informativi geografici, cartografia storica, vegetazione ripariale. keywords: capua, volturno, fluvial dynamic, geographic information systems, historical cartography, riparian vegetation. il quaternario italian journal of quaternary sciences 17(2/2), 2004, 629-642 1. introduzione la ricostruzione del paesaggio nelle diverse epoche storiche è possibile attraverso l’esame di informazioni derivanti da fonti molto articolate. il problema maggiore nell’utilizzazione di queste fonti differenti risiede innanzitutto nel fatto che spesso i dati storicoletterari e le dinamiche territoriali non vengono messe in relazione tra loro, ma sono piuttosto considerate fisse nel tempo. negli ultimi decenni, la rivalutazione dell’ambiente, non più inteso come un insieme di parti separate ed incongruenti, e l’evoluzione delle scienze dell’informazione, che hanno incrementato la possibilità di gestire e integrare una infinita quantità di informazioni della più diversa tipologia ed origine, hanno fornito metodologie di ricostruzione del territorio sicuramente più accurate e dettagliate. queste metodologie, che costituiscono il cuore dei sistemi informativi territoriali, sono innanzitutto un 630 a. mingione et al. metodo di studio e ricerca, ma possono divenire un sistema potente per la valorizzazione di un bene culturale e ambientale, quale può essere appunto il paesaggio. la possibilità d’introduzione della dimensione temporale in un sistema informativo, inoltre, contribuisce enormemente a rendere ancor più dinamico il metodo di studio mettendo in evidenza l’evoluzione passata delle relazioni spaziali e consentendo ipotesi sulle loro evoluzioni future. nel presente lavoro si è cercato di ricostruire le modificazioni territoriali intervenute in un settore della piana attraversata dal fiume volturno nei dintorni di capua (ce) avvalendosi dell’ausilio di un ricco patrimonio di carte geografiche antiche e una cospicua documentazione storico-letteraria. va sottolineato che la storia della città di capua è stata condizionata dalla presenza del volturno sin dalla sua prima edificazione in epoca longobarda, tra l’viii e il ix secolo. il corso fluviale, in quest’area, ha subito, nei secoli, profonde modificazioni morfologiche molto spesso legate ad una contemporanea azione di condizionamento esercitata dall’uomo. relativamente agli ultimi secoli tali variazioni e condizionamenti possono essere ricostruiti, oltre che su base documentaria, anche grazie al gran numero di prodotti cartografici, seppure pre-geodetici. per ottenere una ricostruzione di questi eventi e soprattutto con l’intenzione di verificare quali effetti abbiano avuto nel passato, ed ancora adesso hanno, gli interventi di natura antropica sulle caratteristiche ambientali del sistema fiume, è stato utilizzato un approccio di tipo multidisciplinare: sono state svolte indagini di tipo geologico-geomorfologico, per comprendere quali porzioni di fiume fossero state interessate nel passato da profonde modifiche ad opera dell’uomo, e contemporaneamente sono state condotte indagini sulla vegetazione ripariale, per evidenziare i settori che ospitano fitocenosi le cui caratteristiche testimoniano un’attuale influenza antropica. 2. quadro geologico e geomorfologico l’area indagata per il presente studio è compresa tra la città di capua e i colli tifatini. essa è rappresentata nel foglio n° 172 “caserta” della carta topografica d’italia in scala 1:100000 ed occupa la parte orientale del margine nord-est della piana campana (fig. 1). tutta l’area è compresa tra le quote altimetriche di 19 e 420 metri sul livello del mare. il territorio si presenta costituito prevalentemente da due unità morfologiche che conferiscono un diverso fig. 1 ubicazione dell’area di studio. a) stralcio della carta topografica d’italia i.g.m., foglio 172 caserta – 1:100.000 igm autorizzazione n. 5968 del 18-11-2004. b) carta geologica schematica della piana campana: 1) unità carbonatiche mesozoiche, 2) complessi vulcanici, 3) ignimbrite campana auct., 4) depositi alluvionali olocenici. location map of the studied area. a) topographic map of i.g.m., sheet 172 caserta, 100.000. b) schematic geological map of the campanian plain: 1) mesozoic carbonate units, 2) volcanic complexes, 3) ignimbrite campana auct., 4) holocene alluvial deposits. aspetto al paesaggio. la prima unità, situata nella porzione nord–orientale, è caratterizzata dalle propaggini orientali della dorsale carbonatica dei monti tifatini e presenta una morfologia articolata e a tratti accidentata, fortemente condizionata dagli affioramenti delle rocce carbonatiche, di età giurassico-cretacica, ricoperte, nelle zone meno acclivi, da depositi piroclastici. a tale paesaggio si contrappone quello predominante della pianura sottostante, morfologicamente condizionata dalla messa in posto dei prodotti vulcanici di derivazione prevalentemente flegrea e dalle alluvioni del volturno (ortolani & aprile, 1985; romano et al., 1994; barra et al., 1996; tra gli altri). la fascia di raccordo tra queste due unità morfologiche è rappresentata da cunei di detriti di versante costituiti da depositi vulcanici rimaneggiati, alternati al detrito calcareo anche grossolano. 2.1 il fiume volturno il fiume volturno rappresenta uno dei maggiori corsi d’acqua dell’italia meridionale. esteso tra il territorio del molise e della campania, con i suoi 175 km di lunghezza raccoglie le acque di un bacino imbrifero di ca. 5455 km2. ha origine dalle pendici del gruppo monti della meta-mainarde, in corrispondenza della sorgente di capo volturno, e si snoda tra i rilievi del matese e il versante settentrionale del gruppo del monte maggiore, prima di attraversare la piana campana (cfr. romano et al., 1994; barra et al., 1996; brancaccio et al., 1997). il corso attraversa ampie valli impostate sulle principali linee tettoniche che interrompono la continuità dei rilievi appenninici, prevalentemente carbonatici (brancaccio et al., 1997). le depressioni risultano colmate da potenti successioni di sedimenti fluvio-lacustri (limi e argille con locali intercalazioni di ghiaie, come ad esempio nella piana di alife), a volte terrazzati (es. piana di telese), spesso eteropici con i depositi grossolani in facies di conoide e falda detritica (es. piana di venafro; brancaccio et al., 1997). in corrispondenza della piana di caiazzo, chiusa dalla stretta di triflisco a ponte annibale, in territorio di capua, i margini vallivi sono rappresentati dalle basse colline costituite dai sedimenti arenacei delle “arenarie di caiazzo”. da triflisco alla foce, il volturno attraversa la piana campana assumendo un andamento marcatamente meadriforme, impostato prevalentemente su terreni piroclastici che, nella parte bassa del corso, sono sormontati da spesse successioni di sedimenti alluvionali: limi, argille limose, terreni umiferi scuri e di colmata, della bonifica del basso volturno, intercalati a livelli di lapilli pomicei e torba. prima di immettersi nel tirreno, costituendo un piccolo delta a cuspide in corrispondenza di castelvolturno, il fiume taglia una serie di dune costiere successive di un antico delta (romano et al., 1994; barra et al., 1996). 3. materiali e metodologie di indagine grazie alla disponibilità di un numero significativo di scritti storici e ad un’ampia documentazione iconografica (minute d’autore, disegni, schizzi, mappe) è stato possibile ricostruire l’evoluzione recente di una porzione di territorio attraversato dal fiume volturno nei pressi della città di capua, correlando i risultati di que631cartografia storica e sistemi gis ... sta analisi con alcuni eventi storici. tra i numerosi prodotti cartografici, di tipo pregeodetico, disponibili per l’area (tra cui alcuni particolarmente dettagliati per i loro fini ingegneristici o militari) sono state utilizzate solamente quelle che rappresentavano in maniera attendibile le modificazioni territoriali intervenute tra la fine del 500 e la fine del 1800 nell’area di studio. tra queste, sono state acquisite, analizzate ed elaborate in ambiente gis solo quelle carte che, sulla base di numerosi controlli numerici (ad esempio la precisione raggiungibile nelle georeferenziazioni), sono risultate idonee a questo tipo di elaborazione. come carte geodetiche sono state utilizzate quelle edite dall’igmi (istituto geografico militare italiano) alle scale di riferimento 1:100.000, 1:50.000 e 1:25.000. inoltre sono state acquisite copie delle aerofotogrammetrie numeriche dei comuni di capua, bellona, s. maria c.v., san prisco e caserta che insistono sull’area di studio, realizzate alla scala 1:5000 e 1:2000. la cartografia così acquisita e tutti i dati disponibili per l’area di studio sono stati poi gestiti mediante il software gis geomedia 5.1 pro di intergraph, nel sistema di riferimento gauss-boaga, zona est del meridiano di monte mario, con valore di coordinate assolute espresso in metri. in tal modo sono state rese sovrapponibili, e meglio confrontabili, informazioni territoriali che, normalmente, sono disomogenee in termini di supporto cartografico, proiezione geografica e dettaglio informativo. ogni prodotto è stato georeferenziato, rototraslato e rigenerato su una base cartografica di riferimento. un buon grado di precisione planimetrica nei processi rigenerativi è stato raggiunto grazie all’elevato numero di punti di controllo ed aggancio geodetico, ampiamente distribuiti sul territorio capuano. tra questi, le numerose costruzioni storiche, ancor oggi in parte esistenti o ricostruibili con certezza nella loro posizione assoluta (quali, a titolo d’esempio, manufatti, masserie, poderi, campanili) e l’incrocio di alcune strade riferibili alla centuriazione romana. per controlli su morfologie pregresse e/o ereditate (paleoalvei) è stato inoltre realizzato un modello digitale del terreno (dtm) derivato dai rilievi aerofotogrammetrici alla scala 1:2000. infine, per una migliore comprensione della dinamica fluviale nel territorio in esame, sono stati acquisiti anche dati di sottosuolo, sia derivanti da indagini indirette che da osservazioni di campo su tagli naturali. in particolare, sono state analizzate le stratigrafie allegate a sondaggi geotecnici, e, per alcuni, è stato possibile visionarne direttamente le carote. l’integrazione dei dati ha consentito una valutazione qualitativa dell’andamento dei corpi geologici nel sottosuolo e quindi una migliore comprensione dell’attività fluviale nel tempo. 3.1 elaborazione della cartografia storica in ambiente gis la cartografia storica, acquisita su supporto cartaceo, è stata digitalizzata e memorizzata in formato raster. geomedia pro consente la georeferenziazione di raster utilizzando una base cartografica di riferimento e/o numerosi punti di controllo. la ctr (carta tecnica regionale della regione campania a scala 1:25000) ha rappresentato la base cartografica di riferimento data la 632 sua rappresentatività, intesa sia come ampiezza di territorio raffigurato che come numero di elementi territoriali descritti, e la precisione topografica. e’ stato quindi vettorializzato il corso del fiume volturno rappresentato su ogni singola cartografia: dalla sovrapposizione di tutte le carte sono stati evidenziati i maggiori cambiamenti nella morfologia fluviale, come si discuterà più avanti (§ 4.). come accennato, per un’ulteriore verifica di questi cambiamenti morfologici è stato realizzato un modello digitale del terreno (dtm) derivato dai rilievi aerofotogrammetrici alla scala 1:2000 di capua, bellona, s. maria c.v., e san prisco. i dati altimetrici sono stati estrapolati dai vettori rappresentativi delle curve di livello e dei punti quota, e da essi sono state ricavate le informazioni spaziali (x, y, z) di circa 120.000 punti. per la generazione del modello si è scelta una tecnica a griglia regolare (grid) che utilizza il kriging come algoritmo di interpolazione per il calcolo delle quote in corrispondenza dei nodi della griglia in funzione dei punti vicini al nodo stesso, tramite il software golden software surfer 8.0. tale algoritmo ha permesso di generare il modello altimetrico, tridimensionale, con una risoluzione spaziale di circa 5 metri (fig. 2). al modello tridimensionale della morfologia sono state sovrapposte, separatamente, le basi cartografiche, sia in formato raster (cfr. figg. 10-11) che in quello vettoriale, precedentemente elaborate attraverso la funzione di drappeggio che consente appunto di sovrapporre, ai diversi modelli, dati areali, lineari, e poligonali, o cartografia raster. in tal modo è possibile ottenere la visualizzazione tridimensionale di questi elementi che può aiutare nella comprensione di forme o fenomeni. ciò ha messo in evidenza come lo sviluppo della viabilità si sia sempre stato adattato alle modificazioni dall’andamento del corso fluviale: laddove i meandri sono stati abbandonati, ad esempio, tracciati stradali ne sottolineano ancora l’originario andamento. è stato infine applicato lo shaded relief, una modalità di analisi che permette di determinare l’illuminazione ipotetica di una superficie. operando su alcuni parametri, quali la posizione azimuthale del sole ed il fattore di scala verticale, è possibile mettere in evidenza forme del rilievo che visivamente o alla normale scala di rappresentazione non sono palesemente manifeste; ciò è valido soprattutto per i territori di pianura. 3.2 indagini vegetazionali per evidenziare l’attuale influenza della presenza dell’uomo sulla porzione di fiume che, sulla base dell’analisi cartografica, era stato oggetto nel passato di numerosi interventi, sono stati effettuati rilievi fisionomico-strutturali della vegetazione per valutarne il grado di antropizzazione. nel periodo primaverile del 2004 sono stati individuati 18 punti di campionamento lungo l’asta fluviale disposti a distanza crescente dall’abitato di capua (fig. 3); in ogni punto è stato individuato un transetto diretto ortogonalmente alla sponda fluviale lungo il quale è stato realizzato un profilo fisionomico-strutturale della vegetazione ripariale presente, descrivendo nello stesso tempo anche le caratteristiche morfologiche locali (pendenza ed estensione di eventuali terrazzi) per ottenere una visione integrata che meglio indicasse lo stato e la qualità delle fitocenosi presenti (kent & coker, 1992). lungo ogni transetto sono state rilevate le specie presenti per avere informazioni di tipo qualitativo sulle comunità vegetali; le specie sono state determinate utilizzando le chiavi dicotomiche presenti in pignatti (1992), a cui si è fatto riferimento anche per la nomenclatura. infine, alle sole specie legnose, è stato assegnato un valore di copertura in termini di percentuale per valutare quantitativamente la loro presenza. in fase di analisi, i dati disponibili sono stati utilizzati per ricavare l’inquadramento sintassonomico delle fitocenosi forestali indagate, in accordo a pedrotti & gafta (1996), fino al livello di ordine. 4. evoluzione dell’area sulla base della documentazione storica precedente ai documenti cartografici utilizzati nel corso di questa ricerca, risulta evidente che il volturno è sempre stato considerato una via di comunicazione e di trasporto di grande importanza e per questo motivo, da tempi antichissimi, è stato oggetto di numerosi interventi. la storia della “naturale” dinamica fluviale si è sovrapposta, nei secoli, agli interventi antropici e ai cambiamenti negli usi del suolo. le informazioni derivanti dalla cartografia storica e dalle fonti biblografiche hanno consentito di discernere soprattutto l’influenza antropica sull’assetto fisico del corso del volturno (§ 4.1). dati di sottosuolo, direttamente o indirettamente acquisiti, hanno invece evidenziato i maggiori eventi alluvionali presumibilmente collegati a importanti variazioni climatiche (§ 4.2). 4.1 aspetti antropico-fisici il volturno costituiva una delle vie preferenziali per lo smistamento delle merci già in epoca pre-romana, a. mingione et al. fig. 2 modello digitale del terreno dell’area di studio con rappresentazione del corso del fiume volturno. digital terrain model and overlay of the volturno river. 633 cioè quando capua (l’attuale s. maria capua vetere) rappresentava il centro della vita politica, casilinum (l’odierna capua) il centro delle attività economiche-commerciali, e s. angelo in formis rappresentava il centro di culto (fig. 4). in figura 5 è riportata una ricostruzione dell’area proposta da brock et al. (1972) relativa all’epoca pre-romana e romana: secondo questa ricostruzione a casilinum, sulla sinistra orografica, fu attrezzato un borgo con un porto fluviale, dotato di molo con peculiare architettura a semiluna. gli stessi autori, inoltre, ipotizzano un andamento fluviale, in prossimità dell’attuale città di capua, sostanzialmente più rettilineo, sebbene tale morfologia non sia stata mai confermata da altra documentazione cartografica. unici elementi probanti sono rappresentati dalla configurazione stessa del porto, in contatto con quella che al tempo rappresentava l’area commerciale e con il tracciato della via appia, che attraversava il fiume proprio accanto all’allora porto casilinum (attualmente rappresentato, a capua, da porta roma). nei secoli successivi furono i longobardi che, nell’intento di creare un primo assetto di città fortezza, fecero murare la città di casilinum, e così facendo perimetrarono ed irrigidirono il meandro che si era formato negli anni tra l’epoca romana e quella longobarda stessa; in questa occasione al sito di casilinum fu dato il nome di capua. l’edificazione della cinta muraria e lo sviluppo della città in seno ad un’ansa fluviale che offriva protezione su tre lati, irrigidì definitivamente il corso fluviale in questo tratto (fig. 6). lo stesso non può dirsi per tutto il tratto a monte e a valle della città. l’analisi della cartografia disponibile, soprattutto quella esaminata attraverso strumenti informatici, ha infatti evidenziato rapide modificazioni dell’assetto idrologico dell’area a partire dal xix secolo. nella carta delle grandi manovre (1839; fig. 7) si riconosce un ampio meandro immediatamente a ne di capua. nell’arco di un ventennio, tale meandro subisce un vistoso taglio, non è chiaro se a seguito di opere di bonifica, effettuate tra il 1839 e il 1847, o per necessità militari. né sono da escludere dinamiche assimilabili a meccanismi del tipo “rotta d’argine” (crevassing) a seguito di forti piene, che potrebbero coincidere con un deterioramento climatico registrato a livello globale (“piccola età glaciale”, 1500-1800 ca.; ortolani & cartografia storica e sistemi gis ... fig. 3 localizzazione delle aree di campionamento della vegetazione lungo il fiume volturno. location map of vegetation sampling areas along the volturno river. 634 a. mingione et al. fig. 4 ricostruzione dell’ubicazione di capua e casilinum e delle principali vie di comunicazione in epoca romana. foglio in scala 1:25000, da j. beloch (1989). location map of capua and casilinum and the most important roads during the roman age. map in scale 1:25000, edit by j. beloch (1989). fig. 5 principali assi viari e ricostruzione del possibile andamento dell’asta fluviale in epoca preromana e romana (da brock et al. 1973, modificato). location map of the main roads and the inferred volturno river channel during the pre-roman and roman age (from brock et al. 1973, modified). pagliuca, 1996; cf. § 4.2). fatto sta che nella carta rappresentante battaglia sul volturno (1860) tale salto è evidente, così come la persistenza, nell’ansa abbandonata, di limitati specchi d’acqua (fig 8). in tale documento, inoltre, sono rappresentati, in forma grafica, meandri che solo in tempi relativamente brevi dovevano essere stati tagliati ed abbandonati dal corso principale del fiume volturno (al margine ovest dell’area rappresentata in fig. 8). tutto ciò è messo in risalto anche nella cartografia ufficiale igmi del xx secolo (fig. 9). nella prima edizione della tavoletta capua, realizzata mediante rilievi effettuati nel 1907, edita solo nel 1919, ed in quelle più recenti di capua e grazzanise (1957) nonchè nella ctr tavv. 15, 16 (1987), si trova, come indicazione toponomastica, la dizione fiume morto, per le stesse zone. nei rilievi di inizio secolo, inoltre, sono ancora evidenti condizioni paludose lungo il meandro abbandonato nella seconda metà del 1800. tali tracce si perdono nei successivi interventi antropici sull’area (costruzione dell’autostrada del sole, coltivazioni, etc.) anche se la morfologia generale ancora rispecchia le precedenti condizioni morfologiche. in pochi decenni, dunque, l’area mutò sostanzialmente la sua morfologia, vuoi per azione antropica, vuoi per eventi naturali che hanno indotto o accelerato fenomeni di erosione fluviale e quindi il taglio e il conseguente abbandono di meandri. si evidenzia, difatti, nei documenti della prima metà del xx secolo, anche il prevalere di una tendenza del corso fluviale ad erodere in destra orografica, come riportato sulla cartografia igmi del 1907 e del 1957 (fig. 9), da cui tale tendenza si evince soprattutto dopo l’episodio alluvionale precedente il 1860, laddove il fiume mostra una progressiva erosione della sponda destra. tali dinamiche sono messe in evidenza anche attraverso un altro tipo di rappresentazione e cioè quella derivante dalle elaborazioni effettuate in ambiente gis sul modello digitale del terreno. l’analisi dello shaded relief, infatti, oltre a sottolineare i lineamenti riconosciuti su base documentaria e a cui si è poc’anzi fatto riferimento, pone in risalto, nell’area compresa tra i monti tifatini e la città di capua, ancora un’altra area topograficamente più depressa, marginalmente arcuata che, nella forma, riflette la sagoma di ampi meandri fluviali (fig. 10). gli unici documenti cartografici acquisiti che ne raffigurino le condizioni originarie, sono rappresentati soltanto da minute d’autore del 1700-1800 con scarso valore geodetico. la morfologia tratteggiata in destra orografica, in figura 10, è attualmente sottolineata da un percorso stradale che ne segue fedelmente il profilo. rilievi di campo condotti in loco hanno messo in evidenza chiari episodi di alluvionamento, sottolineati 635cartografia storica e sistemi gis ... fig. 6 “prospettiva di capua” di pacichelli (1703) (da di resta, 1985). “prospettiva di capua” by pacichelli (1703) (from di resta, 1985). da livelli clinostratificati di conglomerati a matrice sabbioso-siltosa passanti a sabbie e limi sabbiosi verso l’interno dell’area circoscritta dall’ipotetico meandro, mentre vestigia dell’originaria vegetazione ripariale sono state completamente cancellate dalle successive pratiche agricole. non sono chiaramente documentabili, invece, facies sedimentarie che testimoniano una passata attività fluviale per ciò che concerne il tratto sottolineato in sinistra orografica nella figura 10, a causa dell’intenso sfruttamento agricolo della zona interessata. né tantomeno la documentazione cartografica acquisita può essere di ausilio per l’impossibilità di georiferire carte di tipo non geodetico e, quindi, di ubicare con precisione eventuali lineamenti coincidenti con quello riconosciuto. 4.2 aspetti geologico-stratigrafici le grosse modificazioni indotte al corso fluviale principale potrebbero trovare plausibile spiegazione in eventi alluvionali rapidi e catastrofici che si sono susseguiti nella piana, come dimostrato dal record stratigrafico locale e come ampiamente riconosciuto in tutto il bacino del mediterraneo (cf. ortolani & pagliuca, 1996). se solo ci limitiamo a capua e alle aree limitrofe, fonti cronachistiche (viparelli, 1992) segnalano, per il solo xx secolo (1915, 1935, 1949, 1952, 1968), notevoli episodi di esondazione in corrispondenza di gravosi eventi di piena che produssero ingenti danni, in seguito ai quali sono state realizzate opere di sistemazione idraulica. se andiamo indietro nel tempo, già beloch (1989) per l’area di casilinum, scrive: “…resti della casilinum romana sono stati trovati su entrambe le sponde, particolarmente sul lato sinistro del fiume, presso eboli, là dove questo fa una svolta verso sud-ovest. si tratta di archi in opus reticulatum e in laterizi di tecnica costruttiva molto elegante che si stendono per un buon tratto lungo il fiume; l’antico, livello del suolo si trovava 30 palmi (1 palmo napoletano = 0,2645 m, n.d.a.) sotto quello attuale e 4 palmi sotto il pelo dell’acqua del volturno, sicché il letto del fiume dall’antichità ad oggi si è sollevato considerevolmente. altri ruderi si trovano di fronte sulla riva destra presso san vincenzo al volturno e ancora più sotto, a sinistra di porta romana. della 636 a. mingione et al. fig. 7 overlay della “carta delle grandi manovre” (1839) sul modello digitale del terreno. “carta delle grandi manovre” (1839) draped over a digital terrain model. conoscenza di tutti questi ruderi dobbiamo ringraziare gli scavi di novi. ora naturalmente tutto ciò è da lungo tempo reinterrato. …”. dati di sondaggi geomeccanici e varie datazioni assolute su depositi torbosi hanno permesso di individuare la presenza di diffuse aree umide in destra e sinistra orografica del fiume volturno tra il vi e v secolo a.c. durante la “piccola età glaciale arcaica” (520-350 a.c.). la presenza di queste aree avrebbe condizionato il tracciato della via appia realizzata tra la fine iv sec. a.c. ed i primi anni del iii-iv sec. a.c. (cf. ortolani & pagliuca, 1996). anche la “piccola età glaciale alto-medievale” (500 d.c. 750 d.c. circa) arrecò pesanti modificazioni all’ambiente. malgrado i romani avessero utilizzato l’espediente di portare verso le aree alte il tracciato dell’appia, essa, tra la centuriazione falerna e casilinum, è sepolta da sedimenti alluvionali di spessori variabili tra 2,50 e 5 m (johannowsky, 1975; caiazza et al., 1998). ad esempio, la via antica, detta via degli spiriti, che collegava l’antica capua (l’attuale s. maria c.v.) al tempio di diana tifatina, sito alle propaggini occidentali del m. tifata, è stata rinvenuta a tre metri di profondità rispetto all’attuale piano di campagna antropizzato in un’area non interessata attualmente da corsi fluviali (cf. fig. 4). l’ampliamento della sede autostradale, a1 milano-napoli, ha evidenziato il basolato in pietra calcarea della strada di probabile età repubblicana; lateralmente si osserva un livelletto, largo circa 4 m, costituito da residui di terracotta e tufo, che rappresenta la probabile sede stradale precedente quella basolata. lo scavo evidenzia che il basolato è stato ricoperto con due strati di ghiaia calcarea, dello spessore di 50 cm ciascuno, prima che la sede stradale e le campagne circostanti venissero definitivamente e completamente sepolti da due-tre metri di detrito vulcanico alluvionale. i riporti di ghiaia sulla sede stradale basolata indicano la necessità di sollevare la sede stradale per difenderla da invasioni di acque e detriti fluviali, necessità evidentemente nuova testimoniante un differente e nuovo regime idrologico che determinerà, successivamente, il ricoprimento del piano di campagna antropizzato fino nella zona del tempio di diana in s. angelo in formis, 637cartografia storica e sistemi gis ... fig. 8 overlay della carta “battaglia del volturno: 1° ottobre 1860” sul modello digitale del terreno. “battaglia del volturno: 1° ottobre 1860” map draped over a digital terrain model. dove i detriti alluvionali avrebbero interessato la basilica con uno spessore di vari metri (caiazza et al., 1998). le descrizioni sin qui riportate documentano una indiscutibile presenza di alluvionamenti, anche catastrofici, nel tratto di piana considerato nel presente lavoro, cui potrebbero verosimilmente ricondursi anche gli episodi di salto di meandro già riconosciuti su base cartografica. osservazioni di dettaglio effettuate su dati di sottosuolo hanno permesso invece di confermare la presunta tendenza del fiume ad erodere prevalentemente in destra orografica. dall’analisi dei dati di sondaggi geognostici, condotti sul territorio comunale di capua a corredo delle indagini geologiche di supporto al piano regolatore generale (ragozzino, 1982), si evince che i depositi che costituiscono l’area esaminata rappresentano il risultato dell’interazione dell’attività vulcanica, connessa alla formazione della piana campana, e dell’azione di rimaneggiamento del fiume volturno. nell’ambito di questi depositi è possibile riconoscere due unità: una unità piroclastica, ascrivibile principalmente alla formazione del tufo grigio campano, che presenta uno spessore variabile tra i 25 e 30 metri e affiora lungo le pendici dei versanti carbonatici e si approfondisce, fino ad immergersi sotto le coperture recenti. si presenta nella litofacies ascrivibile al “tufo grigio” con alternanze di sabbie vulcaniche grigie con inclusi lapidei di varia granulometria, sabbie cineritiche grigiastre, cineriti sabbiose con lapilli e pomici. non sono segnalati intervalli francamente litoidi, quali quelli che caratterizzano la regione pedemontana a settentrione dell’area di caserta. a luoghi sono riconoscibili intervalli argillosi e/o torbosi che documentano presumibilmente interruzioni più o meno prolungate nella deposizione piroclastica ed inizio di pedogenesi (paleosuoli s.l.). una unità di coperture recenti, costituita da una alternanza di sabbie da limose ad argillose, con colori variabili dal giallastro all’azzurrognolo. tali depositi sono distribuiti in maniera discontinua lateralmente, con evidenti intercalazioni e/o rimaneggiamento di 638 a. mingione et al. fig. 9 rappresentazione delle variazioni del corso del volturno dal 1839 ad oggi attraverso l’uso dei sistemi informativi territoriali. overlay map in a gis environment of the volturno river during the 1839-1999 age interval. materiali piroclastici (in particolare nelle zone più attigue alle aree di maggiore spessore dei depositi piroclastici stessi) che conferiscono ai depositi fluviopalustri una colorazione giallastra. molto frequenti, nelle argille e le argille-sabbiose azzurrognole, nuclei e straterelli torbosi oltre che livelli humici. dall’esame dell’andamento in profondità delle unità descritte, fino a circa 20 metri dal p.c., si nota che esse presentano, in destra e sinistra orografica, uno sviluppo lievemente differente. in sinistra orografica, in prossimità dei rilievi calcarei, le unità piroclastiche sono subaffioranti, appoggiandosi su di essi, e si approfondiscono verso l’alveo del volturno fino a mescolarsi con i depositi alluvionali, che acquisiscono spessori sempre maggiori, dapprima fortemente rimescolati alle sabbie vulcaniche, poi assumendo caratteri francamente limoso-argillosi. in destra orografica, invece, non sono documentati materiali tufacei in profondità, ma solo la presenza di spessi depositi francamente alluvionali con frequenti intercalazioni di straterelli di materiale torboso misto ad argilla azzurrogna. quest’ultimo elemento è direttamente legato alla presenza, nel passato, di aree paludose, come precedentemente considerato. 5. caratterizzazione fisionomico-strutturale della vegetazione ripariale se nella documentazione geologica si sovrappongono e si intrecciano i segnali di eventi naturali e di interventi antropici, il dato vegetazionale ha permesso una lettura più esplicita dell’ambiente indagato, in termini di attuale influenza dell’uomo. la vegetazione forestale indagata è risultata essere dominata da specie arboree come salix alba l., populus nigra l. ed in percentuale minore da p. alba l.; a queste specie arboree spesso si aggiunge robinia pseudacacia l. in tutte le aree è stata registrata una scarsa o addirittura assente copertura vegetale nel sottobosco; se presente, quest’ultimo risulta prevalentemente composto da urtica dioica l. e rubus ulmifolius schott ed in misura minore da hedera helix l., arum italicum miller. sulla base di questi risultati le fitocenosi forestali indagate possono essere inquadrate all’interno degli ordini salicetalia purpureae moor 1958 e populetalia albae braun-blanquet ex tchou 1948. entrambi questi ordini comprendono fitocenosi ripariali a carattere spiccatamente pioniero capaci di colonizzare i greti dei fiumi, anche se con lievi differenze ecologiche che ne determinano una diversa localizzazione rispetto all’asta fluviale. nell’ordine salicetalia purpureae moor 1958 sono infatti incluse quelle associazioni vegetali dominate da diverse specie di salici sia arbustivi che arborei che occupano le aree a diretto contatto con l’acqua corrente grazie alle loro spiccate capacità rigenerative che permettono a queste specie di sopravvivere alle inondazioni ed ai danni meccanici a carico dei loro fusti in occasione delle piene. nell’ordine populetalia albae braun-blanquet ex tchou 1948 sono invece incluse fitocenosi forestali dominate da pioppi e che occupano aree golenali o terrazzi meno direttamente interessati dalle dinamiche delle acque fluviali. diversamente da quello che rappresenta la sequenza fitotopografica teorica sopradescritta, nel tratto di fiume indagato non è stato mai possibile osservare una netta distinzione tra i due tipi di vegetazione, che appaiono sempre compenetrati tra di loro in maniera disorganica; tale alterazione del modello distributivo ottimale può 639cartografia storica e sistemi gis ... fig. 10 shaded relief del settore a ne di capua su sui è evidenziata una morfologia legata all’andamento del volturno presumibilmente tra la fine del 1700 e il 1800. shaded relief of the plain northeast of capua. dotted line outlines a morphology related to the volturno river during 1700-1800. 640 a. mingione et al. 641 fig. 11 esempi di profili della vegetazione ripariale nel tratto di fiume indagato. si può notare come nel profilo della vegetazione rilevato nel punto più lontano dal centro abitato ai località bellona (a) siano presenti solamente individui arborei di salix alba l., populus nigra l. e p. alba l. interessante risulta la presenza di rubus ulmifolius schott quasi esclusivo della scarpata a ridosso dei coltivi a testimonianza di una relativa maggiore naturalità di questa comunità, se confrontata con quella descritta dal profilo relativo all'ansa in località limata nel centro di capua (c), dove si osserva una dominanza di robinia pseudacacia l. nello strato arboreo e di rubus ulmifolius schott in quello arbustivo. il profilo descrittivo della vegetazione in località s. angelo in formis (b), a circa metà strada tra i due profili riportati precedentemente, ben rappresenta una situazione intermedia, con una separazione tra l'area più prossima alla riva, occupata da elementi arborei tipici della vegetazione ripariale e la zona di scarpata ed al di sopra di essa dominata da robinia pseudacacia l. examples of profile diagrams of the investigated riparian plant communities. note that in the profile (a) carried out in bellona, very far away from the urban are, only individuals of salix alba l., populus nigra l. and p. alba l. were recorded, and moreover in the shrub layer rubus ulmifolius schott occupies only the slope near the cultivations; this clearly indicates a more natural situation compared with the plant community in limata (c) in the middle of capu,a where dominance of robinia pseudacacia l. for the tree layer and r. ulmifolius schott for shrub layer was observed. the profile diagram carried out in s. angelo in formis (b) located between the two above sampling areas, clearly represents an intermediate community with the characteristic species of the riparian vegetation closer to the river and the slope dominated by r. pseudacacia l. essere chiaramente imputato alla ridotta estensione di spazi liberi nei pressi delle rive, occupati in gran parte da attività antropiche come l’agricoltura, o da fenomeni di inurbazione che si spingono talvolta fin sulle sponde. l’elevato impatto antropico trova un’ulteriore riscontro nell’evidente discontinuità della fascia di vegetazione ripariale lungo il tratto indagato. dal canto suo, l’analisi della composizione floristica di queste comunità conferma la loro elevata alterazione; quasi costante è risultata la presenza di specie tipicamente sinantropiche come rubus ulmifolius schott e urtica dioica l. in particolare quest’ultima specie, notoriamente nitrofila, testimonia l’abbondanza nel suolo di sostanza azotate che potrebbero derivare dall’uso estensivo di fertilizzanti che viene fatto nei coltivi limitrofi. osservando, infine, i diversi transetti si può notare come quelli posti a maggiore distanza dal centro abitato presentino una minore frequenza di specie sinantropiche, la cui frequenza invece aumenta man mano che ci si avvicina al centro abitato; molto evidente è il caso di r. pseudacacia l. che, assente nel transetto 1 (fig. 11a), compare nel transetto 8 (fig. 11b) più vicino a capua, fino a diventare dominante nel transetto 17 (fig. 11c) posto al centro dell’abitato. 6. considerazioni conclusive il fiume volturno, che con il suo corso attraversa l’intero territorio comunale di capua, è dunque il carattere territoriale che da sempre è stato determinante per le sorti della città. attraverso l’uso di software che fanno capo ai sistemi informativi geografici, sono state integrate e correlate informazioni di diversa tipologia ed origine, oltre che di diversa scala temporale e spaziale, che hanno evidenziato come, a macroscala, l’attuale configurazione di questo tratto del fiume sia stato condizionato dalle attività antropiche di regimentazione e di edificazione, cui si sono sovrapposti gli effetti delle variazioni naturali connesse a fattori climatici. l’approccio integrato cartografico-storico/letterario ha dunque consentito di sottolineare l’andamento del fiume volturno nel tempo, le principali direttrici lungo le quali il fiume è migrato, evidenziando vecchi alvei dei quali si è potuto seguire la meandrizzazione ritrovandoli, nella cartografia più recente, solo come letti abbandonati e sottolineando una naturale tendenza del fiume ad erodere e meandrificare soprattutto in destra orogafica. laddove le attività antropiche hanno invece ostacolato la naturale evoluzione della dinamica fluviale, si osserva la permanenza, nei secoli, di una morfologia inalterata. nel caso di capua è estremamente interessante notare come, a tale proposito, l’erezione della cinta muraria intorno alla città, realizzata per volere dei conti longobardi nel ix secolo d.c., e che fiancheggia l’intera ansa all’interno della quale ancora oggi è sito il centro storico, abbia impedito a questo tratto di fiume di evolversi, e quindi di migrare e chiudersi, attraverso i naturali processi di erosione e deposizione. l’analisi, seppur preliminare, di sondaggi geognostici condotti sul territorio comunale di capua, ha evidenziato invece i maggiori eventi alluvionali che hanno contribuito a colmare il settore di piana indagato e che ➧ cartografia storica e sistemi gis ... presumibilmente sono da ricondursi ad importanti variazioni climatiche. le caratteristiche geologico-stratigrafiche riconosciute sono quelle tipiche di una piana alluvionale caratterizzata da un corso fluviale meandriforme e confermano una più marcata attività erosiva in destra orografica e la frequente formazione, nel tempo geologico, di eventi di impaludamento, cui sono spesso seguite azioni di bonifica e/o regimentazione. i risultati emersi nel corso delle indagini di tipo botanico, infine, consentono di porre in risalto l’attuale influenza antropica sul corso del fiume partendo dal rilevamento delle caratteristiche della vegetazione ripariale. analogamente a quanto osservato su molti altri fiumi, sia in studi di carattere più generale (pedrotti & gafta, 1996) che relativi a casi specifici (hruska, 1988; francalancia & marconi, 1994), anche nel caso del fiume volturno le indagini condotte sulla vegetazione hanno evidenziato uno scadimento generale della qualità delle fitocenosi ripariali presenti; la scarsa qualità di queste comunità è innanzitutto testimoniata dalla mosaicizzazione della fascia di vegetazione lungo l’asta fluviale e dalla sua ridotta estensione con conseguente assenza della tipica zonazione della vegetazione ripariale (pedrotti & gafta, 1996). l’abbondanza di specie chiaramente sinatropiche come r. pseudacacia l., rubus ulmifolius schott, urtica dioica l. confermano quanto emerge dall’analisi di tipo strutturale, evidenziando l’alterazione di queste fitocenosi. le osservazioni scaturite dal presente studio, in conclusione, seppure preliminari, permettono di fare una considerazione di carattere metodologico relativamente alla validità di un approccio di tipo multidisciplinare per la definizione della qualità ambientale del “sistema fiume”: i due approcci non solamente concordano giungendo per vie diverse alle stesse conclusioni, ma forniscono una chiave di lettura più completa per la definizione dell’ambiente indagato. bibliografia barra d., romano p., santo a., campatola l., roca v. & tuniz c. (1996) the versilian transgression in the volturno river plain (campania, southern italy): paleoenvironmental history and chronological data. il quaternario, 9 (2), 445–458. brancaccio l., cinque a., di crescenzo g., santangelo n. & scarmiglia f. (1997) alcune osservazioni sulla tettonica quaternaria nell’alta valle del f. volturno (molise). il quaternario, 10 (2), 321–328. carta della “battaglia del volturno: 1° ottobre 1860”. in di resta i. (1985) capua. edizioni laterza. beloch j. (1989) campania. storia e topografia della napoli antica e dei suoi dintorni. a cura di ferone c. e pugliese caratelli f. bibliopolis, napoli. brock i., giuliani p. & moisescu c. (1973) il centro antico di capua. marsilio editore. caiazza d., guadagno g., ortolani f. & pagliuca s. (1998) variazioni climatico-ambientali e riflessi socio-economici nell’alta terra di lavoro tra antichità ed età di mezzo. in: le scienze della terra e l’archeometria, a cura di c. d’amico, c.a. livadie, cuen. “carta delle grandi manovre” (1839). in di resta i. (1985) capua. edizioni laterza. di resta i. (1985) capua. edizioni laterza. francalancia c. & marconi d. (1994) ontanete ad alnus glutinosa nei bacini dei fiumi tronto, tenna e chienti. fitosociologia, 27: 91–95. hruska k. (1988) modificazioni della vegetazione spondale a seguito dell’antropizzazione. bull. mus. st. nat. lunigiana 6–7: 123–126. johannowsky w. (1975) problemi archeologici campani. in rend. acc. arch. lett. bb. aa., napoli. kent m. & coker p. (1992) vegetation description and analysis. a pratical approach. belhaven press, london, 363 pp. i.g.m.i. (1919) carta topografica d’italia foglio 172 – ii no capua – scala 1:25.000. i.g.m.i. (1919) carta topografica d’italia foglio 172 – ii so santa maria capua vetere scala 1:25.000. i.g.m.i. (1919) carta topografica d’italia foglio 172 – ii caserta scala 1:50.000. i.g.m.i. (1954) carta topografica d’italia foglio 172 caserta scala 1:100.000. i.g.m.i. (1957) carta topografica d’italia foglio 172 ii se caserta scala 1:25.000. i.g.m.i. (1957) carta topografica d’italia foglio 172 ii so santa maria capua vetere scala 1:25.000. i.g.m.i. (1993) carta topografica d’italia foglio 431 caserta ovest scala 1:150.000. ortolani f. & aprile f. (1985) principali caratteristiche stratigrafiche e strutturali dei depositi superficiali della piana campana. boll. soc. geol. it., 104, 195–206. ortolani f. & pagliuca s. (1996) variazioni climaticoambientali nel periodo storico nell’area mediterranea: evidenze geoarcheologiche di cicliche crisi ambientali tipo “effetto serra”. convegno il ruolo della geomorfologia nella geologia del quaternario napoli 27-29 febbraio 1996. pedrotti f. & gafta d. (1996) ecologia delle foreste ripariali e paludose dell’italia. collana l’uomo e l’ambiente (23). camerino, università degli studi, 165 pp. pacichelli (1703) prospettiva di capua. in di resta i. (1985) capua. edizioni laterza. pignatti s. (1992) flora d’italia. 3 voll. edagricole, bologna. ragozzino a. (1982) relazione geologica al piano regolatore generale del comune di capua. capua, 1982. regione campania (1987) carta tecnica regionale tavola 16 caserta scala 1:25.000. romano p., santo a. & voltaggio m. (1994) l’evoluzione geomorfologica della pianura del fiume volturno (campania) durante i l tardo quaternario (pleistocene medio–superiore olocene). il quaternario, 7 (1), 41–56. viparelli m. (1992) intervista a referente privilegiato. in: progetto avi relazione finale ed allegati cnrcgndci. 642 ms. ricevuto il 21 maggio 2004 testo definitivo ricevuto il 25 ottobre 2004 ms. received: may 21, 2004 final text received: october 25, 2004 a. mingione et al. imp.farabollini& i travertini dell’ italia centrale adriatica: genesi, cronologia, significato geomorfologico e paleoambientale farabollini piero1, materazzi marco1, miccadei enrico2 & piacentini tommaso2 1dipartimento di scienze della terra, università degli studi di camerino piero.farabollini@unicam.it 2dipartimento di scienze della terra, università degli studi “g. d’annunzio” di chieti miccadei@unich.it riassunto: farabollini p., materazzi m., miccadei e. & piacentini t., i travertini dell’italia centrale adriatica: genesi, cronologia e significato geomorfologico e paleoambientale. it issn 0394-3356, 2004. nella parte adriatica dell’italia centrale depositi travertinosi sono presenti in alcuni affioramenti principali e in una serie di affioramenti minori, distribuiti essenzialmente lungo il fronte della catena appenninica calcarea e in corrispondenza della sua fascia pedemontana. gli affioramenti principali, in particolare, sono distribuiti a diverse quote, da circa 150 m a oltre 900 m s.l.m.; essi inoltre sono disposti, in generale, in appoggio su un substrato calcareo o terrigeno miocenico-pliocenico o sui depositi pliocenico-quaternari, ed in differente correlazione con i depositi continentali quaternari che caratterizzano le valli di alcuni dei principali corsi d’acqua del versante adriatico (fiume esino, fiume potenza, fiume chienti, fiume tronto, fiume pescara, fiume salinello, fiume alento e fiume foro). quasi tutti gli affioramenti studiati evidenziano la presenza di una placca travertinosa in discordanza stratigrafica con il substrato o in successione su depositi prevalentemente grossolani di origine fluviale alternati a facies fluviali di minor spessore caratterizzate da stratificazione piano -parallela ed incrociata, gradazioni, ecc. i depositi di travertino, in particolare, sono caratterizzati da travertini fitoermali talvolta alternati a sabbie e ghiaie calcaree fitoclastiche, ad indicare la presenza di ambienti deposizionali ad “alta energia” localmente associati ad ambienti di acque “calme” generalmente di tipo palustre-lacustre. per quanto riguarda la cronologia dei depositi, di cui alcuni oggetto di recenti datazioni, essi indicano età a partire dal pleistocene superiore all’olocene antico (sefro, pioraco, serrapetrona); altri depositi, invece, la cui datazione è stata basata su correlazioni con altri depositi continentali quaternari, sono attribuibili al pleistocene medio (montepiano e civitella del tronto). tutte le aree analizzate, pur presentando depositi di estensione e spessore differenti, nonché diverse caratteristiche idrochimiche delle acque circolanti, mostrano tuttavia lineamenti comuni, molto significativi al fine della ricostruzione dei meccanismi e degli ambienti deposizionali e del contesto climatico. caratteristica comune a tutti i depositi infatti è la messa in posto in ambiente tipicamente fluviale, sia per la loro disposizione (perlopiù simmetrica e parallela all’asse fluviale), sia per la presenza spesso di strutture tipiche da trasporto che per gli stretti rapporti con i depositi alluvionali presenti lungo l’alveo. nel presente lavoro, oltre a descrivere le caratteristiche deposizionali dei diversi depositi travertinosi presenti nell’area adriatica, e la loro collocazione cronologica, viene proposta una classificazione che, differentemente da quelle esistenti in letteratura, tiene conto di ambienti deposizionali e condizioni morfologiche particolari e più o meno localizzate. abstract: farabollini p., materazzi m., miccadei e. & piacentini t., the travertines of the adriatic central italy: genesis, chronology and geomorphological and palaeoenvironmental significance. it issn 0394-3356, 2004. in the adriatic side of central italy, travertines are present in few main and in several minor deposits, mainly distributed along the calcareous apennine chain and the piedmont belt. main deposits are located at different heights, from about 150 m up to 900 m a.s.l. they usually overlie calcareous or miocene-pliocene terrigenous bedrock or alternatively pliocene-quaternary deposits and are differently related with quaternary continental deposits, characterizing the main river valleys of the adriatic side of central italy (esino, potenza, chienti, tronto, pescara, salinello, alento and foro rivers). almost all deposits are constituted by a travertine plate discordant with bedrock or in succession with coarse fluvial deposits alternating with minor planar or through cross bedded facies, etc.. travertine bodies are constituted by groups of lithofacies, evidencing different depositional mechanisms and environments; phytohermal facies, sometimes intercalated by phytoclastic gravels and sands, progressively changing valley-ward and upward, testify high energy environments locally alternated to low energy ones. concerning the chronology of deposits (some of these recently dated), they indicate age starting from upper pleistocene up to early holocene (sefro, pioraco, serrapetrona); other deposits, whose age is asumed on relationship with other quaternary continental deposits, are attributed to middle pleistocene (montepiano and civitella del tronto). all sites, even though showing deposits with different extension and thickness and different hydrochemical characteristics of circulating waters, have very significant common features, to reconstruct climatic context and depositional mechanisms and environment: typical fluvial environment, symmetric location with respect to river axis, presence of typical structures and close relationships with alluvial deposits. the present work, together with the description of chronology and main depositional mechanisms of the above deposits, also propose a new classification that, differently from other classifications in literature, also consider depositional environments with different, and more or less localized, morphological conditions. parole chiave: deposizione travertinosa, italia centrale adriatica; quaternario. keywords: travertine deposition; adriatic side of central italy; quaternary. il quaternario italian journal of quaternary sciences 17(2/1), 2004, 259-272 260 p. farabollini et al. 1. introduzione il problema della deposizione travertinosa nel versante adriatico dell’italia centrale è stata affrontata da numerosi autori (boni & colacicchi, 1966; cipriani et al., 1977; cilla et al., 1994; calderoni et al., 1996a e b; materazzi, 1996; carrara, 1998; dramis et al., 1999; lombardo et al., 2001; farabollini et al., 2003) ed altrettanto numerosi sono i lavori, a carattere generale, che tentano di classificare i vari depositi sulla base delle loro caratteristiche litologiche e tessiturali (buccino et al., 1978; chafetz & folk, 1984; ferreri, 1985; d’argenio & ferreri, 1986; pedley, 1990; d’argenio & ferreri, 1992; golubic et al., 1993; pentecost & viles, 1994; pentecost, 1995; violante et al., 1994; 1996). tali classificazioni tuttavia non sono sempre funzionali alla descrizione dei depositi riconosciuti nell’area umbromarchigiano-abruzzese. i travertini sono sistemi carbonatici la cui deposizione si verifica in ambiente continentale e risulta controllata dall’interazione tra fattori fisici, chimici e biologici e modificazioni ambientali a seguito della loro deposizione (violante et al., 1994). essi sono edifici complessi e comprendono una grande varietà di forme associate spesso alla presenza, attiva o passiva, di organismi diversi, come batteri, alghe, muschi, o resti vegetali (chafetz & folk, 1984 e relativa bibliografia; golubic et al., 1993 e relativa bibliografia). studi microstrutturali hanno evidenziato che i processi di incrostazione sono prevalentemente controllati da alghe (es: oocardium stratum) e cianobatteri (es: phormidium incrustatum) in analogia con quanto riportati da diversi autori per diverse aree studiate (chafetz & folk, 1984 e relativa bibliografia; golubic et al., 1993 e relativa bibliografia; materazzi 1996 e relativa bibliografia). di seguito si riporta una tabella riassuntiva degli organismi che esercitano un controllo primario sulla deposizione dei travertini (tab. 1) distinguendo le specie che rivestono effettivamente un ruolo attivo nei processi di precipitazione (sottolineate in tab. 1) da quelle che fungono solamente da “impalcature”; sono inoltre evidenziate le specie individuate nelle aree di studio (asterischi in tab. 1, su sfondo grigio quelle più frequenti). il presente lavoro si basa sull’analisi e il confronto, condotti mediante rilevamenti geomorfologici e analisi di dettaglio, delle caratteristiche deposizionali e geomorfologiche dei travertini dell’area marchigiano-abruzzese, inquadrando, ove possibile, la loro collocazione cronologica. si propone in particolare un tentativo di classificazione dei travertini che si differenzia da quelli presenti in letteratura tenendo conto di ambienti deposizionali e condizioni morfologiche particolari, facendo riferimento alle situazioni più significative individuate nell’area. 2. caratteristiche geologiche e geomorfologiche l’area esaminata è delimitata ad occidente dalla catena appenninica, ad oriente dall’area costiera adriatica, a nord e a sud rispettivamente dal fiume esino e dal fiume pescara (fig. 1). sulla base delle caratteristiche fisiografiche, geomorfologiche e strutturali, si possono distinguere due settori diversi: la catena appenninica (in particolare la sua porzione più orientale) e la fascia pedemontana, fino a ridosso dell’area costiera. l’area di catena è caratterizzata da una serie di dorsali montuose allineate in direzione da nwse a ns con sommità sempre superiori a 2000 m, in terreni essenzialmente calcarei, calcareo-marnosi e marnosi, giurassico-paleogenici. le dorsali sono interrotte da profonde valli trasversali solcate dai principali corsi d’acqua (f. potenza, f. chienti, f. tronto, f. salinello, f. pescara). l’assetto strutturale è costituito da sovrascorrimenti a vergenza e e ne che determinano la sovrapposizione di litotipi di natura calcarea su litotipi arenaceo-argillosi (parotto & praturlon, 1975; deiana & pialli, 1992; ghisetti et al., 1994; d’alessandro et al., 2002). la fascia pedemontana presenta un rilievo collinare che degrada dalla catena all’area costiera con cianoficee xantoficee zigoficee briofite gloeocapsa sanguinea* vaucheria* oocardium stratum bryum pallens*, pseudotriquetrum homoeothrix janthina*, crustacea spirogyra cratoneuron commutatum* lyngbya martensiana calcarea* zygnema didymodon tophaceus* phormidium incrustatum* diatomee* eucladium verticillatum* pleurocapsa cloroficee hymenostylium curvirostre* rivularia haematites* gongrosira incrustans* horthothecium rufescens* schizothrix lacustris, lateritia, pulvinata, fasciculata gymnostomum calcareum* scytonema myochrous*, julianum brachytecium rivulare* tabella 1 tabella riassuntiva degli organismi che esercitano un controllo primario sulla deposizione dei travertini: le specie sottolineate rivestono effettivamente un ruolo attivo nei processi di precipitazione, mentre le altre fungono solamente da “impalcature”; gli asterischi invece indicano le specie individuate nelle aree di studio (su sfondo grigio quelle più frequenti). table of organisms exercising primary control on travertine deposition: undersigned species have a real active role on precipitation processes while the others have only the function of “scaffolding”; the stars indicate species recognized in the study area (the most frequent species inside grey boxes). quote che vanno da oltre 1000 m a poche centinaia verso la costa. i rilievi sono costituiti da dorsali isolate, legate alla culminazione di terreni calcarei meso-cenozoici, e da rilievi tipo mesa, cuesta e plateaux, impostati su litotipi terrigeni essenzialmente arenaceo-pelitici e pelitico arenacei, con intercalazioni di orizzonti conglomeratici (servizio geologico d’italia, 1969; cantalamessa et al., 1986; centamore et al., 1991; farabollini, 1995; d’alessandro et al., 2002). questi hanno età riferibile all’intervallo che va dal miocene superiore al pleistocene inferiore e rappresentano il riempimento di bacini di avanfossa e di piggy-back, via via più recenti spostandosi da ovest verso est, e depositi di chiusura (ori et al., 1991; bigi et al., 1995). la strutturazione dell’area è avvenuta tra il pliocene e il pleistocene (calamita et al., 1991 e relativa bibliografia; bigi et al., 1995). dapprima una fase compressiva ha portato alla messa in posto dei principali sistemi di sovrascorrimenti nell’area di catena coinvolgendo progressivamente nell’accavallamento anche i termini di avanfossa via via più orientali. successivamente, alla fase compressiva, ha fatto seguito una attività tettonica distensiva quaternaria, accompagnata da un sollevamento generalizzato (dramis, 1992). nel settore di catena si sono sviluppati importanti sistemi di faglie a direzione nwse e ns con rigetti molto elevati che bordano le principali dorsali e hanno portato alla formazione di ampie conche intermontane. nell’area pedemontana si sono create faglie dirette, anch’esse a direzione da appenninica a ns, ma in genere con rigetti modesti. questi fenomeni determinano un importante condizionamento nella morfogenesi dell’area marchigianoabruzzese e in particolare nell’impostazione e nell’evo261i travertini dell’italia centrale ... luzione del reticolo idrografico e nella distribuzione e tipologia dei processi gravitativi (dramis, 1992; farabollini, 1995). in particolare il settore di catena presenta una morfologia piuttosto aspra sulla quale le sequenze climatiche quaternarie hanno esercitato una influenza notevole, lasciando tracce molto evidenti, date da versanti regolarizzati e detriti stratificati di versante, quest’ultimi prodotti da gelifrazione su versanti denudati dalla copertura vegetale e messi in posto da ruscellamento e movimenti di massa superficiali. la gravità ha infatti svolto e svolge un ruolo molto importante: le evidenze più spettacolari si osservano sui versanti orientali dell’area di catena, dove è possibile riconoscere corone di frana, soprattutto di crollo, a monte delle quali si sono prodotte fessure, gradini, trincee, ondulazioni ed una intensa fratturazione degli strati (dramis et al., 1982; farabollini, 1995). alla sommità dei rilievi sono stati riconosciuti, in limitati lembi di piccola estensione, i resti della paleosuperficie sommitale, la cui frammentazione e dislocazione a quote diverse è da attribuire alla successiva tettonica distensiva ed al sollevamento dell’area, particolarmente intenso e generalizzato a partire dalla fine del pleistocene inferiore (dramis et al., 1982; centamore et al., 1983; dramis, 1992; coltorti & pieruccini, 2000 e relativa bibliografia). alla base del rilievo calcareo, incassata nella superficie precedentemente descritta, è riconoscibile una seconda superficie di spianamento, attribuita dal demangeot (1965) al villafranchiano. essa è stata riconosciuta in tutta l’area esaminata, in corrispondenza dei depositi mio-plio-pleistocenici, dove è ben conservata in estesi lembi presenti sugli spartiacque dei principali fiumi, presentando ondulazioni di quota, comparabili con la superficie sommitale e con i depositi siciliano-crotoniani di chiusura (dramis, 1992; farabollini, 1995). nell’ampia area pedemontana i processi morfogenetici legati alla gravità sono responsabili di una franosità, molto diffusa ed intensa; i processi legati alle acque correnti superficiali hanno modellato un reticolo idrografico molto sviluppato e ampie valli fluviali a decorso prevalentemente ne-sw con gradienti modesti; queste sono solcate dai corsi d’acqua principali che danno origine ad ampie piane alluvionali, con piccole cimose costiere in corrispondenza della foce (coltorti, 1981; dramis et al., 1982; coltorti et al., 1991; farabollini, 1995). l’evoluzione geomorfologica ha determinato la formazione di più o meno estese coltri di depositi continentali quaternari, costituiti da depositi di versante, alluvionali e lacustri nell’area di catena e nelle principali conche intermontane. al di fuori delle dorsali, nell’area pedemontana, lungo le valli dei fiumi principali, sono presenti depositi alluvionali, disposti in quattro ordini di terrazzi ad altezze decrescenti sul fondovalle, connessi alle fasi fredde pleistoceniche e, nelle epoche più recenti, condizionati dall’attività antropica (coltorti, 1981; coltorti et al., 1991; farabollini, 1995). 3. genesi e meccanismi deposizionali il travertino rappresenta uno fra i depositi continentali più diffusi nell’area di studio e la sua età, molto fig. 1 ubicazione dei principali depositi travertinosi (in grigio) dell’italia centrale adriatica. in nero sono riportati i depositi travertinosi descritti nel presente lavoro. location of main travertine deposits (grey points) of the adriatic central italy. black points indicate travertine deposits described in the present work. 262 spesso di non facile collocazione vista la carenza di elementi di datazione, varia generalmente tra il pleistocene medio e l'attuale. generalmente l’origine dei travertini viene in letteratura attribuita ad acque sorgive sovrassature in anidride carbonica. l’analisi di facies (d’argenio & ferreri, 1992; golubic et al., 1993; cilla et al., 1994; farabollini, 1995; materazzi, 1996) evidenzia un meccanismo deposizionale caratterizzato da flussi laminari e turbolenti. i primi depositano croste stromatolitiche ad andamento suborizzontale, cui si associano piccoli canali (in cui avviene la deposizione di sabbie grossolane e ghiaie fitoclastiche a stratificazione incrociata) e talvolta piccoli bacini lacustri, mentre i secondi si realizzano in corrispondenza di cascate e rapide nelle quali si ha la formazione di travertino fitoermale. numerose sono le classificazioni delle morfologie associate alla deposizione di travertino. già nel 1978, buccino et al. (1978), avevano messo in evidenza, nei depositi travertinosi della bassa valle del tanagro (campania), l'esistenza di facies fitoclastiche e fitoermali ipotizzando anche un modello di dinamica fluviale per spiegarne la genesi. successivamente chafets & folk (1984), prendendo anche in considerazione il ruolo rivestito dalle diverse specie vegetali nei processi di incrostazione, dall'esame di alcune località dell'italia centrale e degli stati uniti centro-occidentali, hanno identificato cinque categorie distinte in: waterfall or cascade deposits; shallow lake-fill deposits; sloping mounds, fans and cones; terraces mounds; fissure ridges. nel 1990 pedley, distinse i depositi sulla base del loro angolo di deposizione, della tipologia del flusso d'acqua, delle colonizzazioni microbiologiche e della temperatura ambiente. su tali basi, l'autore riconosce cinque differenti tipi di morfologie: travertini di sorgente, di cascata, fluviali, palustri e lacustri, ognuno composto da una particolare associazione di facies deposizionali detritiche o biocostruite. requisito fondamentale è la quasi totale prevalenza in queste facies della precipitazione legata agli organismi vegetali e/o batterici, anche se viene comunque rilevato un piccolo contributo da parte di processi "inorganici". riprendendo lavori effettuati precedentemente, golubic et al. (1993) riconoscono, per i travertini pleistocenici di rocchetta a volturno, nell'appennino centro-meridionale, sei associazioni di litofacies sulla base delle loro caratteristiche stratigrafico-sedimentarie e sul loro contenuto fossilifero (inclusi anche i supporti vegetali): 1) calcareous sand with travertine intercalations: shallow lacustrine facies; 2) phytoclastic calcarenite and phytohermal travertine: swamp, or shallow sublittoral facies; 3) phytoclastic packstone-grainstone and stromatolitic travertine: gentle slope facies; 4) phytoclastic rudstone, microhermal and stromatolitic travertine: steep slope facies; 5) micro-, and phytohermal travertine and stromatolitic travertine: pool terrace facies; 6) phytohermal travertine: rapids and waterfalls facies. la ricerca si completa anche di uno studio dettagliato sull'ecologia dell'alga desmidiacea oocardium stratum e delle sue caratteristiche sedimentologiche quando viene rinvenuta nei travertini "fossili". i criteri di classificazione sopra citati forniscono un quadro abbastanza chiaro delle litofacies presenti e degli ambienti caratteristici della maggior parte dei travertini conosciuti, non associabili a fenomeni di termalismo. sulla base di questi lavori sono stati condotti rilevamenti geomorfologici e analisi di dettaglio dei principali affioramenti di travertino presenti nell’area marchigiano-abruzzese (fig. 1). le indagini condotte hanno permesso di proporre un modello deposizionale (fig. 2) per i travertini dell'area adriatica marchigiano-abruzzese, che a differenza degli autori sopracitati, tiene conto di ambienti deposizionali a più ampia scala che in molti casi comprendono, contemporaneamente, diverse condizioni morfologiche particolari e più o meno localizzate. per ciascun ambiente sono indicate le caratteristiche essenziali e sono descritti gli affioramenti delle località ritenute più significative. ambiente 1: "aree di sorgente o di versante" questa situazione si riferisce ai travertini che si sviluppano o sugli orifizi delle sorgenti o in aree molto prossime a queste; in tali condizioni le acque sorgive o che comunque hanno percorso tratti molto brevi, liberano la maggior parte della co2 che contengono, favorendo la deposizione del carbonato di calcio che va così ad incrostare spontaneamente sia il substrato che le specie vegetali presenti. in questo caso, la presenza di muschi ed alghe "calcaricole" come le briofite, le cianoficee e le diatomee, peraltro molto numerose in queste zone, sembra non abbia un ruolo così determinante come testimoniato dalla presenza anche di foglie, frustoli o ciottoli ricoperti di caco3. nelle sorgenti vere e proprie, il travertino si deposita a formare piccole collinette intorno all'orifizio ma in qualche caso, ove sono presenti pareti rocciose o massi, può formare anche delle strutture tipo cuscinetto, simili ai "cushions" ed ai "curtains" del modello di cascata di pedley (1990). questi depositi nell'area non hanno di solito dimensioni notevoli ma sono abbastanza frequenti e si localizzano in molte delle sorgenti provenienti dagli acquiferi carbonatici della dorsale umbro-marchigiano-abruzzese. lo schema di figura 2 mostra una situazione abbastanza comune per le aree prossime alla sorgente; queste zone, sono caratterizzate da piccoli rivoli d'acqua che variano continuamente il loro percorso e la loro portata generando una struttura "a gradoni", con piccole pozze dove l'acqua ristagna temporaneamente, ed altre parti dove invece ha uno scorrimento stilicidiale o leggermente canalizzato. quest'ultimo è l'ambiente ideale per lo sviluppo delle specie vegetali come le briofite ed in generale di gran parte delle comunità algali che vivono parzialmente o temporaneamente sommerse dall'acqua; esse incrostandosi formano dei piccoli terrazzetti che tendono a progradare verso l'avanti-basso. nelle pozze invece, si ha una deposizione di tipo detritico: sabbie fitoclastiche si alternano a piccole lenti o straterelli di ghiaie travertinose o a frammenti di fitoerme che sono il prodotto del disfacimento delle facies concrezionate limitrofe. una situazione simile è stata osservata anche all'interno di piccoli canali presenti sui versanti: in questo caso la deposizione è legata all'attività, molte volte temporanea o stagionale, di piccoli fossi tributari del corso principale (es. fiastra e castelli; fig. 1) p. farabollini et al. 263 l’esempio di sant’angelo alla testata della valle del fosso sant’angelo, affluente di sinistra del fiume esino a ridosso della dorsale umbro-marchigiana è possibile osservare un affioramento di travertino tuttora in formazione (fig. 3). il deposito, che mostra un fronte alto più o meno una decina di metri ed è seguibile lateralmente per circa 20÷25 metri, è caratterizzato dalla presenza di briofite come il cratoneuron commutatum, l'eucladium verticillatum e la specie brachytecium rivulare (materazzi, 1996) e mostra una caratteristica morfologia "a gradoni" con presenza di piccoli corsi d'acqua che scendono variando continuamente il loro percorso. la formazione di questo deposito, che mostra una progressiva migrazione verso la destra idrografica, sembra essere iniziata nell'olocene, probabilmente con un'intensità maggiore, ed è continuata fino al giorno d'oggi; la presenza di travertino nell'area in tempi passati è comunque testimoniata da altri due piccoli depositi situati più a valle, ora inattivi, attribuiti all'olocene per la loro posizione rispetto ai depositi alluvionali di fondovalle (materazzi, 1996). ambiente 2: "cascata" in questo secondo caso (fig. 2), rientrano tutti quei depositi che si sviluppano sui fondovalle, dove fig. 3 travertino in formazione nella valle sant’angelo; aeucladium vertici l latum; bbachytecium rivulare; ccratoneuron commutatum. travertine deposition in the s. angelo valley; aeucladium verticillatum; bbachytecium rivulare; ccratoneuron commutatum. fig. 2 classificazione degli ambienti deposizionali di travertino per l’area marchigiano-abruzzese. per la descrizione si veda il testo. classification of travertine depos i t i ona l environments in the abruzzimarchean region. for e x p l a n a t i o n see the text. i travertini dell’italia centrale ... 264 sono presenti nette rotture di pendio o anche dove il gradiente generalmente supera, anche per brevi tratti, una pendenza di 3°÷5°. le situazioni più frequenti sono quelle che ricorrono o al contatto di litologie con forte contrasto di competenza o in prossimità di discontinuità tettoniche (faglie) o in condizioni morfologiche particolari che determinano un disequilibrio nel profilo longitudinale di un corso d'acqua. nel primo caso, tipico dell'area umbro-marchigiana, si può avere la formazione di soglie al contatto tra i termini calcarei e selciferi e quelli più marnosi della successione umbro-marchigiana; soglie morfologicamente simili si possono formare anche per l'azione di faglie normali o trascorrenti con componente diretta. il terzo caso può verificarsi ad esempio alla confluenza di valli con differente grado di approfondimento, dovuto o alla diversità dei terreni attraversati, o alla presenza di condizioni strutturali favorevoli (valli impostate lungo linee tettoniche). l'ambiente in questione, corrispondente in parte al "cascade model" di pedley (1990) o alle litofacies 4, 5 e 6 di golubic et al. (1993), presenta facies deposizionali per certi versi molto simili a quelle osservate nelle aree di sorgente ma se ne differenzia sostanzialmente per due aspetti fondamentali: il primo è che ormai ci troviamo relativamente "lontani" dalla zona di sorgente (di solito qualche chilometro più a valle) e la deposizione avviene sul fondovalle, all'interno dell'alveo e non sui versanti; il secondo è che il fiume, a differenza dell'ambiente precedente, oramai ha un suo corso ben definito, così come l'apporto d'acqua che appare più cospicuo, costante e ben canalizzato. le barriere di travertino che si vengono così a formare, sono costituite quasi totalmente da facies fitoermali mentre quelle fitoclastiche sono presenti in piccoli lenti o livelli; il rapporto tra queste due, in un'ipotetica sezione verticale, è maggiore di 10:1. per quanto riguarda gli elementi costituenti il deposito si può affermare che in questo caso, trovandoci ad una certa distanza dalla sorgente, il contributo delle specie vegetali nella costruzione dell'edificio travertinoso diventa molto consistente: tuttavia permane una discreta componente "inorganica" testimoniata dalla presenza di frustoli, ramoscelli e foglie insieme alle specie propriamente incrostanti. queste ultime sono rappresentate soprattutto da briofite come il cratoneuron commutatum, l 'eucladium vertici l latum e i l didymodon tophaceus, da stromatoliti associate alle diatomee, e in parte anche da cianoficee, come il phormidium incrustatum, che come sappiamo crescono spesso come epitesi sui muschi. questi organismi, sebbene osservati comunemente all'interno di molti dei depositi conosciuti (kempe & emeis,1985; pedley, 1990; golubic et al., 1993) e segnalati lungo i corsi d'acqua in esame, non sono però stati riconosciuti direttamente in tutti i depositi dell'area umbro-marchigiana; nella maggioranza dei casi infatti i depositi sono oramai inattivi, le specie vegetali sono pressoché scomparse dalla loro superficie e le stesse strutture originarie sono state alterate dalla circolazione secondaria delle acque. il loro riconoscimento, ove possibile, è stato ottenuto sulla base di confronti fra le strutture relitte e quelle viventi (materazzi, 1996). il blocco diagramma di figura 2 mostra una delle possibili condizioni morfologiche che possono portare alla formazione di un ambiente di "cascata". il travertino che si viene così a costituire forma una vera e propria barriera che al momento della deposizione tende a progradare verso l'avanti-alto. la notevole porosità associata a questi edifici (e di solito inversamente proporzionale all’età dei depositi), fa si che lo sviluppo sia molto consistente e anche molto rapido: un evidente esempio è quello della penisola balcanica dove in circa 12000 anni dalla fine dell'ultima glaciazione, si sono edificate barriere di travertino alte fino a 50 m (golubic et al., 1993). tale condizione trova anche giustificazione dal fatto che tale processo, una volta iniziato, tende ad autoamplificarsi: infatti si assiste ad un aumento del tempo di permanenza dell'acqua all'interno della struttura con conseguente aumento dei processi microbiologici; questi a loro volta, creano una nuova catena biologica favorita anche dalla presenza di rapide e cascate che determinano zone fortemente areate, ideali per lo sviluppo di nuove specie. l’esempio di roccamontepiano la placca di travertino, che sorge alle spalle dell’abitato di roccamontepiano (nell’abruzzo teramano) e che costituisce un altipiano situato a circa 650 m s.l.m., è dato da un affioramento tabulare di travertini, di forma sub-rettangolare, allungato in direzione grossomodo appenninica. tale placca poggia, nella sua parte meridionale, mediante contatto erosivo, su sedimenti sabbioso-conglomeratici, spessi 5÷6 m, che a loro volta poggiano sui litotipi argillosi marini (fig. 4); queste litologie sono probabilmente attribuibili alla formazione di mutignano (d’alessandro et al., 2002). l’estesa copertura detritica, presente ai piedi di tale placca, non permette di osservare altrove tale contatto; sembra comunque che, per la maggior parte della sua estensione, essa poggi sulla formazione argillosa marina. l’estesa placca travertinosa è costituita da diverse litofacies sviluppate sia in senso orizzontale che verticale, riconoscibili anche alla scala decimetrica (fig. 4). in particolare la parte inferiore dell’affioramento è caratterizzata in prevalenza da sabbie e limi calcarei, stratificati, e da lenti di travertini stromatolitici e oncoliti; verso l’alto passano a calcareniti e calciruditi fitoclastiche, organizzate in strati spessi e irregolari, frequentemente anastomizzati, con lenti di travertini fitoermali. il settore settentrionale e quello nord-orientale sono caratterizzati da travertini microermali di incrostazione su muschi, e stromatolitici, con stratificazioni ondulate disposte a formare delle vasche, riempite da calcareniti fitoclastiche a stratificazione piano-parallela e sub-orizzontale. lo spessore dei travertini è variabile da 15 a 40 m, con valori massimi sul bordo orientale del pianoro (d’alessandro et al., 2002). al di sopra del deposito travertinoso è presente un paleosuolo di tipo fersiallitico, molto evoluto e ricco in frammenti di selce e concrezioni ferro-manganesifere, con spessore anche fino ad un metro. la posizione morfo-stratigrafica di questi sedimenti, in relazione ai depositi alluvionali terrazzati affioranti lungo le valli del f. alento e del f. foro, insieme alla presenza del paleosuolo al tetto dei travertini, permettono di riferirne l’età al pleistocene medio e più precisamente, in analogia con quelli di civitella del tronto, alla penultima fase interglaciale. p. farabollini et al. l’esempio di civitella del tronto i travertini di civitella del tronto, sono distribuiti in tre affioramenti che da nord verso sud sono: monte santo (544 m), civitella del tronto (645 m) e colle san nicola (671 m). tali depositi, il cui spessore varia in modo molto brusco tra 50 e 5 metri, si presentano in forma di placche, con pareti a picco e con geometria vagamente cuneiforme in direzione all’incirca ns. nel complesso le tre placche sembrano avere una forma lenticolare, in cui il maggior spessore della parte centrale, disposta secondo la direzione del corso fluviale del salinello, si trova in corrispondenza dell’abitato di civitella del tronto. la placca travertinosa poggia su una superficie di erosione che taglia il substrato arenaceo-pelitico della laga, come nel caso di civitella del tronto, o su ciottoli grossolani arrotondati e subarrotondati di origine fluviale, con una parvenza di embriaciatura che sembra indicare una corrente con direzione circa ns, come nel caso di montesanto o di colle san nicola (farabollini, 1999). superiormente si rinvengono sabbie e ghiaie travertinose (sh e gp di miall, 1978) a cui sono associate facies tipicamente fluviali caratterizzate da stratificazioni, gradazioni, ecc., per uno spessore variabile tra i 20÷30cm, che passano gradualmente ad una associazione data da alternanze di sabbie travertinose e travertini fitoermali ad indicare ambienti di polle con frequenti incursioni di acque calcarifere. lateralmente ed anche al di sopra di questa associazione, ne è riconoscibile una seconda formata da travertino microermale, travertino stromatolitico e fitoermale. al loro interno è possibile osservare piccoli canali riempiti da ciottoli travertinosi arrotondati e/o da pisoliti con diametro a volte superiore ai 2÷3cm. tale associazione permette di ipotizzare la presenza di un pendio più o meno acclive dove la deposizione travertinosa contribuiva ad accrescerne l’acclività. alla sommità è presente un livello di spessore notevole (circa 20 metri a civitella del tronto) caratterizzato da travertino fitoermale che indica rotture di pendio importanti e la progradazione verso valle delle facies di cascata (farabollini, 1999). nella placca di colle san nicola inoltre è stato differenziato un livello sommitale più poroso, assente negli altri due depositi, che presenta il rapporto tra gli isotopi del carbonio nettamente differente, anche se le altre caratteristiche si mantengono all’incirca simili (preite martinez et al., 1990). lo studio, a carattere palinologico (de sanctis & fregonese, 1981), ha messo in evidenza che la deposizione dei travertini dell’area di civitella del tronto, nel complesso sembra essere avvenuta in un contesto climatico tipicamente interglaciale, in cui i materiali più porosi (come il livello presente alla sommità della placca travertinosa di colle san nicola e che gli autori sopra citati indicano come più recenti) sarebbero riferibili ad un ambiente di clima temperato caldo, mentre quelli più massivi, si sarebbero depositati in condizioni climatiche più fredde. le evidenze geomorfologiche, come la presenza di un lembo di terrazzo alluvionale del ii ordine, posto a circa 50 metri più a valle, attribuito alla fase finale del pleistocene medio, la posizione topografica delle placche rispetto a questo deposito, la presenza alla base delle placche di travertino di clasti calcarei arrotondati di chiara origine fluviale che marcano un antico fondovalle pre-ii ordine (farabollini, 1999), testimoniano che la deposizione dei travertini è più antica della fase alluvionale del pleistocene medio finale e può essere indicativamente riferita al penultimo interglaciale. ambiente 3: "cascate e vasche" e' sicuramente una delle situazioni più frequenti tra quelle osservate nel presente studio e tra quelle segnalate in letteratura (cilla et al., 1994; calderoni et al., 1996a e b; dramis et al., 1999; farabollini et al., 2003). l'ambiente in questione è per certi versi molto simile a quello di "cascata". anche in questo caso infatti ci troviamo in una porzione del corso d'acqua caratterizzata da un gradiente mediamente alto e da rotture del profilo longitudinale più o meno sviluppate e pure le 265 fig. 4 sezione schematica della placca travertinosa di montepiano. tftravertino fitoermale; lsmlenti stromatolitiche e microermali; tfctravertino fitoclastico; lfelenti fitoermali; ononcoliti; sltsabbie e limi travertinosi; cmconglomerati marino (formazione di mutignano); lamlimi ed argille marine (formazione di mutignano). schematic profile of the montepiano travertine plate. tf – phytohermal travertine; lsm – stromatolitic and microhermal lens; tfc – phytoclastic travertine; lfe – phytohermal lens; on – oncolites; slt – travertine sands and silts; cmmarine conglomerates (formazione di mutignano); lammarine silts and clays (formazione di mutignano). i travertini dell’italia centrale ... condizioni morfologiche sono pressoché identiche: tettonica e assetto strutturale delle varie litologie presenti, restano infatti i fattori condizionanti la formazione di questi depositi mentre la differenza è legata unicamente all'entità dei dislivelli e alla gradualità della pendenza del profilo longitudinale del corso d'acqua. il modello proposto, rappresentato schematicamente in figura 2, si differenzia dal "phytoherm framestone barrage" di pedley (1990) per la forma finale dell'edificio. tale modello inoltre raggruppa le associazioni di litofacies 1 e 3 di golubic et al. (1993) e variamente anche le litofacies 4, 5 e 6, riconosciute peraltro anche nell'ambiente di "cascata". il deposito che si forma in questo contesto è costituito da un'alternanza di facies fitoermali (uguali a quelle dell'ambiente di "cascata", ma con maggiore presenza di travertino stromatolitico) e facies fitoclastiche di vario spessore, costituite da corpi e livelli limosi, sabbiosi e ghiaiosi, massivi o stratificati. facendo riferimento all'ambiente 2, queste sono presenti in un rapporto minore di 10:1 anche se, nella maggioranza dei casi, questo rapporto può scendere fino a 1:1 o addirittura mostrare una prevalenza delle facies fitoclastiche su quelle fitoermali. per quanto riguarda la dinamica di formazione, come abbiamo detto, la situazione è molto simile a quella descritta nell'ambiente di "cascata". lungo il corso d'acqua infatti, in prossimità di queste piccole rotture di pendio, si formavano dei banconi di travertino fitoermale in facies di cascata che tendevano a progradare verso l'avanti-alto; nelle zone di raccordo tra i banconi invece, dove il gradiente era pressoché nullo si depositavano delle facies detritiche prevalentemente sabbiose (fitoclastiche), provenienti dall'erosione dei corpi fitoermali più a monte. con il procedere della deposizione, l'edificio si accresceva realizzando una sovrapposizione dei termini fitoermali su quelli fitoclastici. in questa tipologia di ambiente ricadono, come già specificato, la maggior parte dei depositi travertinosi riconosciuti nell’area di studio (sefro, pievetorina, roccafluvione, ecc.) l’esempio di sefro in questa località, il deposito travertinoso, che forma un bancone di spessore modesto (3÷5 m), presenta la morfologia tipica di un sistema di "cascate e vasche", sebbene le facies fitoermali di cascata siano maggiormente sviluppate. la presenza di tale bancone a livello dell'alveo attuale del torrente scarzito ed i suoi rapporti con i depositi fluviali e lacustri, permettono di ipotizzare una deposizione alquanto recente, cioè durante l'optimum climatico dell'olocene (materazzi, 1996). poco più a valle del deposito descritto, in sinistra idrografica, è presente un piccolo lembo di travertino depositatosi al di sopra di uno deposito ghiaioso, di origine fluviale, discretamente cementato, del pleistocene medio-finale (materazzi, 1996). al tetto della sequenza, depositi detriti stratificati di versante del pleistocene superiore sigillano il deposito stesso, collocando così questa fase deposizionale durante l'ultimo interglaciale (fig. 5). al contatto tra le ghiaie fluviali ed il travertino è stato rinvenuto un paleosuolo fersiallitico parzialmente colluviato, solitamente presente al tetto dei depositi alluvionali del i e del ii ordine (coltorti, 1981; coltorti et al., 1991) a conferma dell’antichità di tale deposito rispetto a quello presente lungo l’alveo fluviale. il meccanismo deposizionale e le varie facies sono praticamente le stesse che caratterizzano il deposito riconosciuto a serravalle di chienti lungo l’alveo del fiume chienti, dove presenta uno spessore di pochi metri. fig. 5 sezione schematica del deposito di travertino di sefro (tftravertino fitoermale). schematic profile of the travertine deposit at sefro (tf – phytohermal travertine). l’esempio di pievetorina nei pressi dell’abitato di pievetorina, lungo una valle trasversale al fiume chienti (fig. 1) sono presenti due diverse generazioni di depositi travertinosi, di cui la più antica, è posta a diverse decine di metri sul talweg mentre l’altra, più recente, si sviluppa in destra idrografica del fosso di pievetorina a quote di pochi metri dall’alveo attuale. in particolare i depositi più significativi sono rappresentati proprio da questi ultimi, in quanto si sviluppano per qualche centinaia di metri lungo l’asse fluviale anche se sono generalmente affioranti solo in destra idrografica. i depositi più antichi, poco estesi e generalmente obliterati da una estesa copertura detritica e colluviale, costituiscono un piccolo terrazzo di travertino alto pochi metri e seguibile, anche se in maniera discontinua per la fitta vegetazione, per circa 20÷30 metri. i depositi più bassi invece sono dati da una sequenza travertinosa di notevole spessore, fino a 10 266 p. farabollini et al. metri, e seppur mascherati in superficie da coltri colluviali spesse anche fino a un metro, sono ben visibili per effetto dell'incisione fluviale (fig. 6). essi sono formati dall'alternanza di facies fitoclastiche (tfc: ghiaie, sabbie e limi travertinosi) e facies fitoermali (tf: travertino concrezionato in posto). fig. 6 foto dell’affioramento del travertino di pievetorina (tftravertino fitoermale; tfctravertino fitoclastico). travertine deposit at pievetorina (tf phytohermal travertine; tfc phytoclastic travertine) dal basso verso l'alto, sono stati osservati 60 cm di sabbie molto fini e limi travertinosi con piccole lenti di ghiaie travertinose fini a stratificazione planare (gp di miall, 1978), osservabile in corrispondenza del letto fluviale; verso monte e superiormente, per circa 4÷5 metri, queste facies passano a banconi di travertino fitoermale compatto, inclinato di circa 20°÷25° contromonte. al di sopra, per circa un metro e mezzo, sono visibili alternanze di sabbie fini e limi travertinosi dello spessore di 20÷40 cm e di limi argillosi scuri, spessi da 1 a 4÷5 cm. in alcuni casi si riconoscono sottili livelli argillosi dello spessore di circa 10 cm. inoltre si riconoscono livelli di ghiaie travertinose molto grossolane che arrivano fino alle dimensioni di vari centimetri di diametro: si tratta generalmente di frammenti di travertino fitoermale e di travertino stromatolitico prodotto dal disfacimento di banconi di travertino fitoermale situati più a monte. procedendo verso l'alto la sequenza evidenzia la presenza di banconi di travertino fitoermale con inclinazione di circa 20° contromonte. al tetto della sequenza è stato infine riconosciuto un suolo bruno alluvionale contenente ciottoli di travertino fitoermale detritico spessi fino a 10 cm. l’esempio di roccafluvione il deposito in questione è posto lungo la valle del torrente fluvione, in corrispondenza dell’abitato di roccafluvione, ad una quota di circa 275m s.l.m., e si estende verso valle per una lunghezza di circa 800 m, con uno spessore massimo di circa 10 metri. in particolare il deposito studiato è ubicato al di sopra della piana alluvionale di iii ordine su cui sorge l’abitato di roccafluvione, e risulta inciso dal corso d’acqua attuale, posto circa 20 metri più in basso. le scarpate fluviali, generalmente scolpite nei litotipi della formazione della laga, permettono di verificare come, sia in destra che in sinistra idrografica, al di sopra del substrato arenaceo, siano presenti depositi travertinosi fitoermali, di spessore di circa 6 metri, clinostratificati verso monte di qualche grado, e che si estendono anche diverse decine di metri. verso l’alto essi passano a facies tipicamente fitoclastiche, costituite da sabbie e limi travertinosi e subordinatamente ghiaie travertinose. lungo la piana alluvionale che costituisce il terrazzo di iii ordine, lavori di sbancamento per la realizzazione di opere infrastrutturali, hanno permesso di verificare come il deposito travertinoso poggi, a luoghi, sui depositi alluvionali terrazzati dati da ghiaie grossolane eterometriche e poligeniche, immerse in abbondante matrice sabbioso-argillosa, per uno spessore di circa 1 metro, che riempiono canali scavati nel substrato (facies gm e gt di miall, 1978). anche se la sezione presenta una altezza di circa 2 metri ed una estensione laterale di qualche decina di metri, è comunque possibile valutare i rapporti reciproci tra i vari deposti presenti. in particolare i depositi travertinosi sono rappresentati da facies fitoermali, generalmente accresciuti su supporti vegetali dati principalmente da muschi, rami e foglie, che passano lateralmente a travertino fitoclastico e croste stromatolitiche, che formano corpi che presentano estensione laterale anche dell’ordine di diversi metri. alla sommità, al di sopra di materiali colluviali, è presente un suolo brunastro riconoscibile per tutta l’estensione della piana alluvionale del iii ordine. ambiente 4: "canali travertinosi delle piane alluvionali" questa situazione, abbastanza ricorrente, è caratteristica delle aree esterne alla dorsale carbonatica marchigiano-abruzzese dove il gradiente diminuisce fortemente e dove le valli si allargano, ormai modellate nei terreni recenti più erodibili (marnosi, arenacei ed argillosi). in queste zone, alla fine del pleistocene superiore, avveniva la deposizione delle alluvioni terrazzate del iii ordine che formavano ampie pianure in regime braided. con l'inizio dell'olocene però il regime cambiava; il generale miglioramento climatico favoriva infatti lo sviluppo della vegetazione sui versanti e la conseguente diminuzione del carico solido negli alvei innescava processi di incisione e portava alla formazione di canali che incidevano debolmente la sommità del terrazzo pleistocenico. proprio all'interno di questi canali avveniva, durante i periodi più caldi dell'olocene, la deposizione di piccoli spessori di facies fitoclastiche e fitoermali di travertino. sempre facendo riferimento ai criteri di classificazione di pedley (1990) e di golubic et al. (1993), queste facies possono essere paragonate al "braided fluviatile model" del primo o alle litofacies 1 e 3 dell'autore slavo e sono costituite principalmente da 267i travertini dell’italia centrale ... livelli ghiaiosi e sabbiosi fitoclastici, spesso a stratificazione incrociata (tipici di canali a sinuosità mediobassa) e da piccole fitoerme dove frequente è la presenza di travertino stromatolitico (fig. 2). l’esempio di pioraco in questa zona, circa un paio di chilometri a monte dell'abitato di castelraimondo, la piana alluvionale del pleistocene superiore del fiume potenza ha un'estensione laterale di circa 500m mentre lo spessore del deposito si aggira sui 10÷15 m. al tetto di questo deposito sono riconoscibili alcuni piccoli canali, incisi per circa 1÷1,50 m riempiti a tratti da facies fitoclastiche e fitoermali di travertino e da travertino stromatolitico che marcavano le fasi di magra dell'attività del canale. l’esempio di serrapetrona lungo l’alta valle di un affluente di sinistra del fiume chienti, nei pressi di serrapetrona, nel versante orientale della dorsale marchigiana, è stata osservata una potente sequenza detritica ed alluvionale (fig. 7), di circa 40 metri, posta ad alcune decine di metri sul corso attuale. in particolare dal basso verso l’alto la sequenza risulta costituita, per circa 35 m di spessore, da livelli detritici (dv) grossolani e subangolosi ai quali si intercalano ed alternano, a varie altezze, livelli tipicamente fluviali (facies gt di miall, 1978), dati da clasti subarrotondati appiattiti e ben addensati, che mostrano una debole stratificazione incrociata a basso angolo. superiormente la sequenza è caratterizzata dalla presenza di sedimenti clastici subangolari per uno spessore complessivo di 4 metri, che seppelliscono un paleosuolo bruno calcico (pb) di circa 10 cm, e ricoprono in parte un paleocanale ghiaioso, profondo circa 3 metri e con spessore di circa 1,5 metri. all’interno del deposito il ritrovamento di materiali ceramici fluitati di epoca storica è stato collegato con il denudamento dei versanti operato dall’uomo in epoca storica che avrebbero innescato intensi fenomeni di erosione con formazione di spessi corpi colluviali ai piedi del versante (farabollini, 1995; calderoni et al., 1996b). alla base del canale si osservano lenti ghiaiose grossolane (facies gm di miall, 1978), alle quali si alternano livelli centimetrici di travertino fitoermale e croste stromatolitiche (tf), a testimonianza di condizioni climatiche di tipo temperato umido caratterizzato dalla presenza di una estesa copertura vegetale. all’interno di un livello argilloso nerastro (la), di 30÷40cm, con scheletro costituito da clasti subangolari di 2÷10 cm, sono stati trovati numerosi frammenti ceramici non fluitati, quest’ultimi attribuiti all’eneolitico (farabollini, 1995; calderoni et al., 1996b). la datazione radiometrica effettuata su carboni presenti in tale livello, che ha fornito una età di 4750±65 (calderoni et al., 1996b), permette di riferire la sequenza all’olocene antico. il canale è colmato da un metro di sabbie fitoclastiche a stratificazione piano-parallela (sfc) che passano lateralmente a travertino fitoermale. 4. cronologia e significato paleoambientale la deposizione del travertino nell’area adriatica marchigiano-abruzzese è sicuramente un fenomeno molto importante ai fini della ricostruzione del contesto paleoambientale del quaternario. le differenti fasi deposizionali osservate, infatti, possono essere inquadrate in periodi climatici e/o storici ben precisi. in primo luogo appare evidente come, in assenza di fenomeni particolari (idrotermalismo o presenza di acque “acide” generalmente sulfuree, di provenienza profonda) il contesto climatico sia senza dubbio fondamentale per spiegare la genesi e lo sviluppo di tali depositi; la presenza di travertino all'interno delle valli fluviali durante il quaternario, è innanzitutto un fenomeno generalizzato e più o meno contemporaneo a livello mondiale nei paesi temperati o attualmente subtropicali (ford & pedley, 1996 e relativa bibliografia; materazzi, 1996 e relativa bibliografia). come evidenziato in particolare da nicod (1986), la grande quantità di carbonato in soluzione, responsabile della formazione del travertino, è legato alla forte presenza di co2 nelle acque percolanti il substrato calcareo; questo gas, di origine biologica, è a sua volta legato allo sviluppo di potenti spessori di suoli formatisi nei periodi interglaciali quando il generale riscaldamento successivo alle fasi fredde glaciali aveva favorito l'incremento della vegetazione sui versanti. una così cospicua copertura vegetale favoriva anche la regolarizzazione del regime idrico: la capacità dei suoli di trattenere le acque, che poi venivano restituite all'alveo in un periodo di tempo più lungo, permetteva un arricchimento maggiore di anidride carbonica e 268 fig. 7 sezione schematica del deposito di travertino di serrapetrona (pb paleosuolo bruno; tf travertino fitoermale; gmghiaie; sfcsabbie fitoclastiche a stratificazione piano-parallela; lalivello antropico; dvdetriti di versante; gtghiaie a stratificazione incrociata a basso angolo). schematic profile of serrapetrona travertine deposit (pbbrown paleosoil; tfphytohermal travertine; gmgravels; sfcplanar cross-bedded phytoclastic sands; laanthropic level; dvslope deposit; gtlow angle through cross-bedded gravels). p. farabollini et al. assicurava inoltre ai corsi d'acqua un costante, anche se non ingente, apporto d'acqua, condizione estremamente vantaggiosa per lo sviluppo delle specie vegetali costituenti il travertino (muschi ed alghe). i dati cronologici raccolti nell’area di studio concordano perfettamente con le premesse suddette; per quanto riguarda i depositi più “antichi”, dei quali non si è potuto effettuare datazioni assolute (civitella del tronto, roccamontepiano, sefro), la loro collocazione stratigrafica rispetto ad altri elementi geomorfologici noti (depositi alluvionali terrazzati, conoidi alluvionali, depositi di versante, paleosuoli ecc.) ha permesso infatti di inquadrare la deposizione in un contesto climatico caldoumido come quello tipico dei periodi interglaciali. i depositi recenti invece (s. angelo, serrapetrona, pievetorina, pioraco; roccafluvione, ecc.), anche sulla base di datazioni radiometriche effettuate essenzialmente su resti vegetali fossili, possono essere collocati in un periodo compreso fra l’olocene antico (preboreale, circa 9000 yr b.p.) e il subatlantico (circa 3000 yr b.p.) fatta esclusione per i depositi ancora in formazione (es. s. angelo, castelli). tale fase si inquadrerebbe perfettamente (almeno nel periodo preboreale-atlantico, fino a circa 5300 yr b.p.) nell’ ”optimum climatico” olocenico, caratterizzato da una generale fase di riscaldamento (2°÷3° in più rispetto al presente nelle medie ed alte latitudini, zubakov & borzenkova, 1990). tali dati sarebbero inoltre in linea con quelli osservati in altre località dell’appennino centrale (calderoni et al., 1996b; cilla et al., 1994; materazzi, 1996). il fattore climatico, in concomitanza con gli eventi tettonici pleistocenici, sembrerebbe poi spiegare anche il differente sviluppo (inteso in senso di estensione areale e di spessore) dei travertini antichi, solitamente maggiore rispetto a quelli olocenici. da una parte infatti, la durata maggiore sia delle fasi fredde, che dei periodi interglaciali del pleistocene inferiore e medio, potrebbe giustificare uno sviluppo maggiore dei travertini proprio per un più lungo perdurare delle condizioni favorevoli alla deposizione. d’altro canto, il forte sollevamento tettonico pleistocenico (dramis, 1992) favoriva anche l’approfondimento, soprattutto nei periodi interglaciali caratterizzati da un incremento dell’erosione lineare, delle valle fluviali con conseguente rapido abbassamento della superficie piezometrica ed aumento del regime idrologico dei corsi d’acqua (farabollini et al., 2003). tale effetto, più intenso inizialmente, veniva progressivamente diminuendo in relazione al riequilibrio con il nuovo livello piezometrico di base (fig. 8). ben più complessa sembra essere invece la teoria sul più o meno generalizzato declino, fino alla completa cessazione, del fenomeno deposizionale in particolare per quanto riguarda l’olocene recente: due filoni di pensiero, talvolta in netto contrasto, associano infatti tale scomparsa, a livello globale, alternativamente a cause climatiche o antropiche (goudie, 1993). la prima corrente (geurts, 1976; preece et al., 1986) considera come causa fondamentale il progressivo raffreddamento e passaggio verso condizioni più aride (lamb, 1995) avvenuto nell’intervallo subboreale – subatlantico (periodo definito anche come “intervallo neoglaciale”) testimoniato in italia ad esempio da avanzate glaciali nelle alpi e forte instabilità climatica; tali variazioni avrebbero di conseguenza modificato anche il regime idrologico dei corsi d’acqua con conseguente crisi dei sistemi deposizionali travertinosi. una seconda teoria (nicod, 1986; vaudour, 1986; weisrock, 1986; coltorti et al., 1991) ritiene invece determinante l’importanza dell’impatto antropico sui versanti avvenuto in molte località alla fine del neolitico ed all’inizio dell’età del bronzo (fig. 9). il passaggio in questo periodo da una cultura prevalentemente nomade e pastorale, ad una di tipo agricolo e stabile e gli intensi disboscamenti operati per il reperimento di legname da costruzione e riscaldamento avrebbe innescato repentini processi di erosione della copertura pedologica; la scomparsa del suolo, principale fornitore della co2 necessaria per la dissoluzione dei carbonati, unita ad un progressivo intorbidimento delle acque per l'aumentato carico solido proveniente dai versanti ed il passaggio da un regime di flusso non molto intenso ma costante, ad uno più ingente, intermittente e canalizzato, avrebbero cancellato i requisiti necessari al prosieguo della sedimentazione travertinosa. recentemente dramis et al. (1999) hanno proposto una teoria sull’influenza delle variazioni di temperatura passate, nei sistemi acquiferi carbonatici. in particolare tali autori sottolineano l’importanza dei forti squilibri termici esistenti, all’inizio delle fasi climatiche più calde, fra le acque sotterranee (influenzate dalla “roccia serbatoio”, a più bassa conducibilità termica e quindi 269 fig. 8 schema delle caratteristiche paleoambientali del reticolo fluviale in corrispondenza delle variazioni climatiche quaternarie. sketch of paleoclimatic characteristics of the hydrographic network related to quaternary climatic variations. i travertini dell’italia centrale ... ancora in equilibrio con le condizioni “glaciali” precedenti) e le temperature esterne, che salivano molto più velocemente. tale effetto, ovviamente non esclusivo, confermerebbe il ruolo climatico, esaltando la fase deposizionale iniziale ed in parte fornendo una spiegazione al declino del processo, in relazione all’ormai raggiunto equilibrio fra le sopracitate temperature della roccia e dell’aria. fig. 9 cronologia pleistocenica ed olocenica della deposizione travertinosa. il tratto nero indica l’intervallo cronologico desunto da datazioni assolute; il tratteggio invece indica l’intervallo cronologico desunto da correlazioni geomorfologiche. pleistocene and holocene chronology of travertine deposition. black line indicates chronological interval obtained by absolute dating; dashed line indicates chronological interval obtained by geomorphological correlations. 5. conclusioni gli studi condotti sui depositi travertinosi dell’italia centrale adriatica, assieme ai dati derivanti da studi già effettuati nell’area in esame, hanno permesso di confermare come la deposizione travertinosa avvenga essenzialmente in corrispondenza di rotture del profilo dei corsi d’acqua. la crescita di questi corpi è legata soprattutto al concrezionamento su “supporti” vegetali che produce la formazione di veri e propri sbarramenti. a monte si formano piccoli bacini lacustri e/o palustri su cui sui depositano materiali fitoclastici (provenienti dalla degradazione di corpi fitoermali posti più a monte). caratteristica comune a tutti i depositi travertinosi dell’area adriatica marchigiano-abruzzese è la messa in posto in ambiente tipicamente fluviale: ➢ sia per la loro disposizione (per lo più simmetrica e parallela all’asse fluviale); ➢ sia per la presenza di frequenti strutture tipiche da trasporto; ➢ sia per gli stretti rapporti con i depositi alluvionali presenti lungo l’alveo. la presenza di diverse generazioni di depositi travertinosi disposti a quote diverse sul fondovalle attuale, la presenza alla base delle placche di travertino di clasti calcarei arrotondati di chiara origine fluviale che marcano antichi livelli di fondovalle, studi palinologici, che evidenziano come la deposizione dei travertini, nel complesso, sembra essere avvenuta in un contesto climatico tipicamente interglaciale, avvalorano l’ipotesi di come la più o meno intensa deposizione di travertino (estremamente differente anche all’interno delle stesse aree studiate, durante fasi diverse) sia da associare ad un regime idrologico che veniva mutando nel tempo. tale fenomeno, insieme al sollevamento tettonico ed alle variazioni climatiche quaternarie, sembrerebbe il maggiore responsabile della progressiva diminuzione, fino in qualche caso alla totale interruzione, della deposizione di travertino, oltre a fenomeni legati all’antropizzazione, particolarmente evidente a partire dall’olocene antico. infine, sulla base dei reciproci rapporti tra i depositi su menzionati, è stata proposta una nuova classificazione dei meccanismi deposizionali che, differentemente da quelle esistenti in letteratura, tiene conto di ambienti deposizionali e condizioni morfologiche particolari e più o meno localizzate. ringraziamenti gli autori desiderano ringraziare i referees per gli utili consigli nella revisione del testo. lavoro eseguito con fondi di ateneo dott. farabollini e prof. miccadei. il presente lavoro è frutto della ricerca e della collaborazione di tutti gli autori. in particolare farabollini p. ha coordinato la ricerca e con materazzi m. ha eseguito i rilevamenti geomorfologici e le analisi di dettaglio nell’area marchigiana e teramana e curato i modelli interpretativi; miccadei e. ha coordinato i rilevamenti geomorfologici e le analisi nell’area abruzzese; piacentini t. ha eseguito le analisi di dettaglio e i rilevamenti geomorfologici nell’area abruzzese. bibliografia bigi s., cantalamessa g., centamore e., didaskalou p., dramis f., farabollini p., gentili b., invernizzi c., micarelli a., nisio s., pambianchi g. & potetti m. (1995) la fascia periadriatica marchigiano-abruzzese dal pliocene medio ai tempi attuali: evoluzione tettonico-sedimentaria e geomorfologica. studi geol. camerti, vol. spec. 1995/1, 37-49. boni c. & colacicchi r. (1966) i travertini della valle del tronto: giacitura, genesi e cronologia. mem. soc. geol. it., 5, 315-339. buccino g., d'argenio b., ferreri v., brancaccio l., ferreri m., panichic. & stanzione d. (1978) i travertini della bassa valle del tanagro (campania): studio geomorfologico, sedimentologico e geochi270 p. farabollini et al. mico. boll. soc. geol. it., 97, 617-646. calamita f., cello g., centamore e., deiana g., micarelli a., paltrinieri w. & ridolfi m. (1991) stile deformativo e cronologia della deformazione lungo tre sezioni bilanciate dall’appennino umbromarchigiano alla costa adriatica. studi geol. camerti, vol. spec. crop 03, 295-314. calderoni g., cilla g., dramis f., esu d., magnatti m. & materazzi m. (1996a) reconnaissance study of early holocene travertine deposits in the basins of the esino, giano, potenza and chienti rivers (umbro-marchean apennines, central italy). abs. conference “late glacial and early holocene climatic and environmental changes in italy”, trento (italy, 7-9 febbraio 1996). calderoni g., cilla g., dramis f., esu d., magnatti m. & materazzii m. (1996b) la deposizione di travertino nelle aree prossimali dei fiumi esino, potenza e chienti durante l'olocene antico (appennino umbro-marchigiano). il quaternario, 9 (2), 481492. cantalamessa g., casnedi r., centamore e., chiocchini u., colalongo m.l., crescenti u., micarelli a., nanni t., pasini m., potetti m. & ricci lucchif. (1986) i l plio-pleistocene marchigianoabruzzese. studi geol. camerti, vol. spec. “la geologia delle marche” guida all’escursione, 43 pp. carrara c. (1998) i travertini della valle del pescara tra popoli e tor de' passeri (abruzzo, italia centrale). il quaternario, 11 (2), 163-178. centamore e., coltorti m., dramis f., cantalamessa g., d’angelo s., di lorito l., sacchi l. & sposatoa. (1983) aspetti neotettonici e geomorfologici del foglio 133-134, ascoli piceno-giulianova. pubbl. n. 513 del p.f. geodinamica, 371-386. centamore e., cantalamessa g., micarelli a., potetti m., berti d., bigi s., morelli c. & ridolfi m. (1991) stratigrafia e analisi di facies dei depositi del miocene e del pliocene inferiore dell’avanfossa marchigiano-abruzzese e delle zone limitrofe. studi geol. camerti, vol. spec. crop 11, 125131. chafets h.s. & folk r.l. (1984) travertines: depositional morphology and the bacterially constructed constituents. journal sedim. petrology, 54 (1), 289-316. cilla g., coltorti m. & dramis f. (1994) holocene fluvial dynamics in mountain areas: the case of the river esino (appennino umbro-marchigiano). geog. fis. dinam. quat., 17, 163-174. cipriani n., malesani p. & vannucci s. (1977) i travertini dell’italia centrale. boll. serv. geol. it., 98, 85115. coltorti m. (1981) lo stato attuale delle conoscenze sul pleistocene ed il paleolitico inferiore e medio della regione marchigiana. atti i conv. beni culturali e ambientali delle marche, paleane ed., 63-122. coltorti m., consoli m., dramis f., gentili b. & pambianchi g. (1991) evoluzione geomorfologica delle piane alluvionali delle marche centro-meridionali. geogr. fis. dinam. quat., 14, 87-100. coltorti m. & pieruccini p. (2000) a late lower pliocene planation surface across the italian peninsula: a key tool in neotectonic studies. journal of geodynamics, 29, 323-328. d’alessandro l., genevois r., berti m., urbani a., tecca p.r. (2002) geomorphology, stability analisyses and stabilization works on the montepiano travertinous cliff (central italy). in: allison r.j. (ed.) applied geomorphology: theory and pratice, wiley & sons, 233 pp. d’argenio b. & ferreri v. (1986) a brief outline of sedimentary models for pleistocene travertine accumulation in southern italy. rend. soc. geol. it., 9, 167-170. d’argenio b. & ferreri v. (1992) ambienti di deposizione e litofacies dei travertini quaternari dell’italia meridionale. mem. soc. geol. it., 41, 861-868. deiana g. & pialli g. (1992) the structural provinces of the umbro-marchean apennines. mem. soc. geol. it., 473-484. demangeot j. (1965) geomorphologie des abruzzes adriatiques. cnrs, memoires et documents, paris, 403 pp. de sanctis l. & fregonese d. (1981) i travertini di civitella del tronto. geo-archeologia, 51-60. dramis f. (1992) il ruolo dei sollevamenti tettonici ad ampio raggio nella genesi del rilievo appenninico. studi geol. camerti, vol. spec. 1992/1, 9-16. dramis f., agostini s., coltorti m., cresta s., d’angelo s., pantaleone a., pica a., rossi a., sacchi l. & sposato a. (1982) aspetti fisiografici e morfogenesi in atto nei bacini dei fiumi salinello e vibrata. antropologia contemporanea, 5 (1/2), 183-188. dramis f., materazzi m. & cilla g. (1999) influence of climatic changes on freshwater travertine deposition: a new hypothesis. phys. chem. earth (a), 24 (10), 893-897. farabollini p. (1995) evoluzione geomorfologica quaternaria dell’area periadriatica tra ancona e vasto. università di perugia, tesi di dottorato inedita, 154 pp. farabollini p. (1999) il ruolo delle acque correnti superficiali: esempi dall’area della montagna dei fiori (te). studi geol. camerti, vol. spec. 1999, 93-102. farabollini p., gentili b., materazzi m. & pambianchi g. (2003) freshwater travertines deposition in mountain area: examples of climatic and tectonic interaction from central apennine (italy). prooc. intern. workshop on “climate changes, active tectonics and related geomorphic effects in high mountain belts and plateaux”, addis ababa 9-10 dicembre 2002. ferreri v. (1985) criteri di analisi di facies e classificazione dei travertini quaternari dell’italia centromeridionale. rend. acc. scienze fis. mat, 52, 47 pp. ford t.d. & pedley h.m. (1996) a review of tufa and travertine deposits of the world. earth science review, 41, 117-175. geurts m.a. (1976) genèse et stratigraphie des travertins de fond de vallée en belgique . acta geographica lovaniensa, 16, 66 pp. ghisetti f., follador., casnedi r. & vezzani l. (1994) 271i travertini dell’italia centrale ... assetto tettonico delle zone esterne dell’appennino abruzzese: elementi di analisi stratigrafico-strutturali. atti tic. sc. terra, ser. spec., 2, 543. golubic s., violante c., ferreri v. & d’argenio b. (1993) algal control and early diagenesis in quaternary travertine formation (rocchetta a volturno, central apennines). boll. soc. paleont. it, vol. spec., 1, 231-247. goudie a. (1993) the human impact. man's role in environmental change. basil blackwell, oxford, 326 pp. kempe s. & emeis k. (1985) carbonate chemistry and the formation of the plitvice lakes. in: degens et al. (eds). transport of carbon and minerals in major world rivers, part 3. mitt. geol. paläontol. inst. univ. hamburg, 58, 351-383. lamb h. h. (1995) climate history and the modern world. routhledge, london, 433 pp. lombardo m., calderoni g., d’alessandro l. & miccadei e. (2001) the travertine deposits of the upper pescara valley (central abruzzi, italy): a clue for the reconstruction of the late quaternary palaeoenvironmental evolution of the area. in: visconti et al . (eds.) global change and protected areas. kluwer acad. publ., 459-464. materazzi m. (1996) i travertini dell’appennino umbromarchigiano: genesi evoluzione e cronologia. tesi di dottorato inedita. università di perugia, 1996. miall a.d. (1978) fluvial sedimentology. can. soc. petrol. geol., mem. 5, 1-47. nicod j. (1986) facteurs phisico-chimique de l'accumulation des formations travertineuses. méditerranée, 1-2, 161-164. ori g.c., serafini g., visentin c., ricci lucchi f., casnedi r., colalongo m.l. & mosna s. (1991) the plio-pleistocene adriatic foredeep (marche and abruzzo, italy): an integrated approach to surface and subsurface geology. 3rd e.a.p.g. conf., florence, 85pp. parotto m. & praturlon a. (1975) geological summary of the central apennines. in: ogniben et al., eds. structural model of italy: maps and explanatory notes. quaderni ric. sci., c.n.r., 90, 257311. pedley h.m. (1990) classification and environmental models of cool freshwater tufas. sedimentary geology, 68, 143-154. pentecost a. (1995) the quaternary travertine deposits of europe and asia minor. quat. science review, 14, 1005-1028. pentecost a. & viles h. (1994) a review and reassessment of travertine classification. géographie physique et quaternaire, 48 (3), 305-314. preece r.c., thorpe p.m. & robinson j.e. (1986) confirmation of an interglacial age for the condat tufa (dordogne, france) from biostratigraphic and isotopic data. journal of quaternary science, 1, 57-65. preite martinez m., severa f., turi b. & fregonese d. (1990) i travertini di civitella del tronto. aspetti geochimici e giacimentologici. rend. fis. acc. lincei, ser. 9, 1, 15-24. servizio geologico d’italia (1969) carta geologica d’italia alla scala 1:100.000 foglio n.133-34 ascoli piceno giulianova. vaudorj. (1986) travertins holocène et pression anthropique. mèditerranèe, 57 (1-2), 165-167. violante c., d’argenio b. & ferreri v. (1994) quaternary travertines at rocchetta a volturno (isernia, central italy). facies analysis and sedimentary model of an organogenic carbonate system. i.a.s. 15th reg. meet., 13-15 april 1994, ischia, guide book to the field trip, 3-23. violante c., ferreri v. & d’argenio b. (1996) modificazioni geomorfiche controllate dalla deposizione di travertino. il quaternario, 9 (1), 213-216. weisrock a. (1986) géomorphologie et paléoenvironments de l'atlas atlantique (maroc). paris, 931 pp. zubakov v.a. & borzenkova i.i. (1990) global paleoclimate of the late cenozoic. developments in palaeontology and stratigraphy, 12, elsevier, 453 pp. 272 ms. ricevuto l’11 maggio 2004 testo definitivo ricevuto il 18 agosto 2004 ms. received: maj 11, 2004 final text received: august 18, 2004 p. farabollini et al. imp.spalluto_moretti evidenze di neotettonica (pliocene medio pleistocene superiore) nel settore occidentale del promontorio del gargano (italia meridionale) luigi spalluto 1 & massimo moretti 1-2 1 dipartimento di geologia e geofisica. 2 centro interdipartimentale di ricerca per la valutazione e mitigazione del rischio sismico e vulcanico. università degli studi di bari, via e. orabona 4, 70125 bari (italy) l.spalluto@geo.uniba.it m.moretti@geo.uniba.it riassunto: l. spalluto & m. moretti: evidenze di neotettonica (pliocene medio pleistocene superiore) nel settore occidentale del promontorio del gargano (italia meridionale). (it issn 0394-3356, 2005). il settore di studio è localizzato lungo il bordo occidentale del promontorio del gargano, in un’area compresa fra san severo e apricena (foggia). esso comprende quindi parte del dominio geodinamico-strutturale dell’avampaese apulo e parte del dominio dell’avanfossa bradanica. in particolare, il primo comprende un tratto del margine occidentale del promontorio del gargano costituito in prevalenza da rocce carbonatiche autoctone mesozoiche e cenozoiche interessate da strutture tettoniche legate a deformazione di natura fragile prodottesi in prevalenza durante le fasi orogenetiche appenniniche; il secondo corrisponde ad un tratto dell’adiacente depressione tettonica del tavoliere delle puglie coperta da depositi silicoclastici marini e continentali e costituente parte del settore nord-orientale dell’avanfossa bradanica. l’area in esame è considerata, sulla base dei dati di letteratura, un’importante zona sismica: la maggior parte delle faglie è stata attiva probabilmente già dalla fine del cretaceo. sulla base di dati strutturali e stratigrafici alcuni autori riconoscono infatti due fasi tettoniche distinte nel cretaceo e nel miocene, menzionando la tettonica plio-pleistocenica come un’unica fase geodinamica successiva. nell’intero avampaese apulo però, il plio-pleistocene è caratterizzato da due distinte fasi di evoluzione geodinamica: una marcata subsidenza (circa 2 mm/anno nel pliocene pleistocene inferiore) connessa alla subduzione appenninica ed una successiva fase di moderato uplift (circa 0,5 mm/anno nel pleistocene medio-superiore). il sollevamento dell'avampaese apulo è tuttora attivo e gran parte delle strutture tettoniche ad attività recente si inserisce in questo quadro geodinamico. l’obiettivo di questo lavoro è quello di evidenziare i dati stratigrafici utili a differenziare le strutture ad attività pliocene pleistocene inferiore da quelle con attività più recente. gran parte dei dati stratigrafici e tettonici è stata raccolta nell'ambito dei nuovi fogli della carta geologica d'italia (scala 1:50.000) durante il rilevamento geologico del foglio n° 396 "san severo". la fase di subsidenza (pliocene – pleistocene inferiore) connessa alla subduzione appenninica è registrata nell’area di studio dalla tettonica distensiva che interessa la calcarenite di gravina (localmente attribuita al pliocene medio-superiore). le evidenze di tettonica sinsedimentaria sono rappresentate essenzialmente da faglie di crescita e dicchi nettuniani. la fase di sollevamento pleistocenica è segnata dalla presenza di depositi marini e continentali terrazzati del supersintema del tavoliere delle puglie che marcano la graduale riemersione di questo settore dalla fine del pleistocene inferiore fino all'attuale. il progressivo sollevamento dell'area in esame può essere desunto dallo studio dei caratteri evolutivi delle unità marine e continentali terrazzate. le unità terrazzate più antiche sono interessate da faglie prevalentemente distensive e datano quindi l’attività di queste strutture al post-pleistocene medio. abstract: l. spalluto & m. moretti: neotectonics of the western sector of the gargano promontory (plio-pleistocene, southern italy). (it issn 0394-3356, 2005). the analysed area is located in the western part of the gargano promontory (northern emerged sector of the apulian foreland, southern italy): this area comprises the mesozoic and cenozoic carbonate units of the apulian foreland and the northern sector of the plio-pleistocene bradanic trough. many authors mention the western portion of the gargano area as an important seismogenic zone, which have suffered some mediumto high-magnitude historical and instrumentally-recorded earthquakes. in this area, some of the faults with a suggested recent to present-day activity have probably been active since mesozoic time and it is often very hard to establish the age of the observed displacements. on the basis of the available stratigraphic and structural data, some authors have distinguished at least two different tectonic phases in late cretaceous and miocene times. moreover, they mentioned a plio-pleistocene tectonic activity as a successive single tectonic phase. according to the regional data, during the plio-pleistocene, this area (and the entire apulian foreland) was subject to two different tectonic phases: the first one (pliocene to lower pleistocene in age) was related with the active subduction of the apulian foreland beneath the southern apenninic chain; during this phase, the apulian foreland recorded an high subsidence rate (about 2 mm/yr); from the sicilian to present-day, the entire apulian foreland was subject to a moderate uplift (less than 0,5 mm/yr). it is very important to distinguish the structural elements of the subsidence stage from them associated with the uplift since only the last ones are directly related with the present-day active tectonics. during the geologic survey for the carg project (san severo 1:50.000 sheet) we have found much evidence of neotectonics in this area and the aim of this work is to show the stratigraphically–recorded tectonic activity during the plio-pleistocene. in the apricena area (masseria zingari locality), some extensional features have been observed: they are represented by narrow grabens (few tens of meters in length) which cut miocene limestones and are transferred to the overlying calcarenite di gravina formation (late pliocene in age). the synsedimentary activity of these grabens is documented by the presence of narrow folds and by the variations in thickness of the calcarenite di gravina formation. the maximum displacement is always less than 5 m and it decreases upwards. along the cuts of the older and inactive railway in the same area, a complex distensive fault occurs in the calcarenite di gravina formation (and in its miocene substrate): folds and growth structures involve the overlying calcarenites along the primary and secondary fault planes. the last evidence of the subsidence phase is given by large-scale neptunian dykes (up to 5 m in height): they are restricted at the contact between miocene limestones and the overlying calcarenite di gravina formation and are represented by large conical fractures in the miocene substratum which are filled by the overlying pliocene calcarenites; that is a record of synsedimentary extensional tectonic activity since the overlying unit suffers soft-sediment deformation and many decimetric beds are downward-projected and/or irregularly folded during the extensional brittle deformation of the substratum. the middleto upper-pleistocene uplift of this area is chiefly documented by the presence of marine and continental terraced deposits il quaternario italian journal of quaternary sciences 19(1), 2006 143-154 144 l. spalluto & m. moretti 1. introduzione l’area di interesse ricade nel foglio n° 396 “san severo” (scala 1:50.000) e comprende ad est il settore nord-occidentale del gargano e ad ovest un ampio settore del tavoliere delle puglie (fig. 1). quest’area rappresenta un’importante zona sismogenetica in cui sono stati registrati strumentalmente e su base storica terremoti di magnitudo moderato-alta (tinti et al., 1995; piccardi, 1998; borre et al., 2003; patacca & scandone, 2004; piccardi, 2005). in questo lavoro vengono analizzati i dati stratigrafici inediti emersi nel corso del rilevamento geologico per la realizzazione del foglio 396 “san severo” alla scala 1:50.000 e relativi alle unità plio-pleistoceniche affioranti nell’area, che rappresentano: records stratigrafici delle differenti fasi geodinamiche cui è stata soggetta l’area d’interesse; vincoli stratigrafici per datare direttamente le faglie certamente attive durante il plio-pleistocene. è opportuno evidenziare che nella recente letteratura in questo stesso settore di indagine sono stati riconosciuti gli effetti di una sola fase tettonica attiva durante il plio-pleistocene, che avrebbe principalmente riattivato strutture formatesi durante le fasi tettoniche precedenti (chilovi et al., 2000). queste evidenze non collimano con i dati regionali noti per l’avampaese apulo e la fossa bradanica, che, in questo stesso intervallo di tempo, indicano la presenza sia di effetti connessi alla fase tettonica distensiva che si estende dal pliocene fino al pleistocene inferiore interessando l'intero avampaese apulo coinvolto nella subduzione verso ovest al di sotto dell'appennino meridionale, sia di una successiva fase di sollevamento attiva a partire dal pleistocene medio (ciaranfi et al., 1979; 1983; 1988; pieri, 1980; ricchetti et al., 1988). scopo di questo lavoro è quello di evidenziare, attraverso i nuovi vincoli stratigrafici, le strutture tettoniche ad attività pliocene medio pleistocene inferiore da quelle con attività più recente connesse alla fase di uplift del pleistocene mediosuperiore; queste ultime sono le uniche che hanno anche un'importanza ai fini degli studi di tettonica attiva. effetti di tettonica sinsedimentaria connessi alla fase di subsidenza, molto simili a quelli descritti in questo lavoro lungo il settore occidentale del promontorio del gargano, sono stati segnalati anche lungo il bordo bradanico delle murge, nelle profonde incisioni del f. bradano e dei suoi affluenti (tropeano et al., 1994). i dati stratigrafici e tettonici sono stati raccolti nell'ambito della realizzazione dei nuovi fogli della carta geologica d'italia (scala 1:50.000 – progetto c.a.r.g.) durante il rilevamento geologico del foglio n° 396 "san severo" di cui g. ricchetti è stato responsabile scientifico e p. pieri direttore dei rilevamenti. 2. inquadramento geologico l’area di studio (fig. 1) ricade nel settore occidentale del promontorio del gargano nel settore di transizione tra i domini di avampaese (“avampaese apulo” in d’argenio et al., 1973; ricchetti, 1980) e di avanfossa (“fossa bradanica” in selli, 1962; d’argenio et al., 1973) dell’appennino meridionale. la porzione di avampaese affiorante è costituita da calcari meso-cenozoici di piattaforma carbonatica (“piattaforma apula” in d’argenio, 1974) interessati prevalentemente da una deformazione tettonica disgiuntiva (funiciello et al., 1988; bertotti et al., 1999; chilovi et al., 2000). secondo studi strutturali e stratigrafici recenti, nell’area di studio sono state differenziate una fase tettonica supracretacica (chilovi et al., 2000; morsilli et al., 2002; spalluto, 2004), una fase tettonica del miocenepliocene inferiore coeva con le fasi più importanti dell’orogenesi appenninica (chilovi et al., 2000) ed una tettonica plio-pleistocenica. quest’ultima viene spesso that crop out from 140 m a.s.l. to 20 m a. s. l. the documentation of the discrete faults associated with this uplift phase is often very difficult because there are not extensive and continuous outcrops of the middle-upper pleistocene units. nevertheless, in a quarry located to the nw of apricena town we have found an extensional fault that cuts the entire thickness of a marine terraced unit (colle degli ulivi subsynthem). the fault is subvertical, e-w oriented and the maximum vertical displacement is up to 20 m in height. similar tectonic features have been reported in the younger san severo subsynthem. parole chiave: neotettonica, calcarenite di gravina, argille subappennine, supersintema del tavoliere delle puglie, pliocene mediopleistocene superiore, promontorio del gargano, italia meridionale. keywords: neotectonics, calcarenite di gravina, argille subappennine, tavoliere delle puglie supersynthem, middle pliocene-upper pleistocene, gargano promontory, southern italy. fig. 1 schema geologico del settore settentrionale della regione puglia ed ubicazione del foglio 396 "san severo". geologic sketch of the northern sector of the apulia region. the location of the sheet 396 "san severo"is shown. identificata come una singola fase che avrebbe riattivato strutture più antiche (chilovi et al., 2000; tondi et al., 2005). nell’avampaese apulo e nella fossa bradanica, il plio-pleistocene è segnato da due distinte fasi geodinamiche (ricchetti et al., 1988; doglioni et al., 1994; 1996). in particolare, durante il pliocene mediopleistocene inferiore, i settori più occidentali dell’avampaese apulo sono stati interessati da una marcata fase di subsidenza (circa 2 mm/anno in doglioni et al., 1994) connessa alla subduzione appenninica. durante questa fase, ampi settori di avampaese evolvono ad avanfossa. in tale contesto la sedimentazione nella fossa bradanica è avvenuta dapprima con depositi carbonatici di mare basso ascritt i al la calcarenite di gravina e successivamente con le emipelagiti siltoso-argillose delle argille subappennine. la calcarenite di gravina (pliocene medio-pleistocene inferiore) poggia in discordanza con un contatto trasgressivo sui calcari ai bordi degli alti strutturali relativi dell’avampaese apulo (tropeano & sabato, 2000; pomar & tropeano, 2001). le argille subappennine (pliocene medio-pleistocene inferiore) poggiano in continuità di sedimentazione sulla calcarenite di gravina e marcano la fase di massimo approfondimento della fossa bradanica (pieri et al., 1996). questa unità rappresenta il substrato sedimentario su cui poggiano tutte le unità marine e continentali più recenti. i dati di letteratura indicano che, a partire dal pleistocene medio, l'intero avampaese apulo è stato invece soggetto ad un moderato sollevamento (ciaranfi et al., 1983; ricchetti et al., 1988; doglioni et al., 1994; 1996; gambini & tozzi, 1996), testimoniato a livello regionale dai depositi regressivi della fossa bradanica e dai depositi marini terrazzati che si rinvengono a quote decrescenti, dai più antichi ai più recenti (ciaranfi et al., 1988; tropeano et al., 2002). nell’area di interesse tali depositi vengono riportati nella cartografia geologica ufficiale alla scala 1:100.000 (f°155 “s. severo” boni et al., 1969; f°156 “s.marco in lamis” cremonini et al., 1971; f°163 “lucera” jacobacci et al., 1967; f° 164 “foggia” merla et al., 1969) con denominazioni differenti; in alcuni casi vengono descritti in continuità sulle argille subappennine (boni et al., 1969; cremonini et al., 1971), in altri casi come depositi marini terrazzati post-calabriani (jacobacci et al., 1967; merla et al., 1969). nella carta geologica dell’appennino meridionale (bonardi et al., 1988) nel tavoliere delle puglie, viene distinta una zona, al di sopra dei 350 m di quota, nella quale sarebbero presenti depositi correlabili con la successione bradanica (riconosciuti a sud dell’ofanto da ricchetti, 1967 e valduga, 1973) ed un settore meno elevato che si estende fino al golfo di manfredonia nel quale sarebbero presenti depositi marini terrazzati. nei lavori successivi sul plio-quaternario del tavoliere delle puglie (boenzi et al., 1992; caldara & pennetta, 1989; 1993; capuano et al., 1996; aucelli et al., 1997) sia le denominazioni di tali depositi che le attribuzioni cronologiche si riferiscono ora allo schema proposto da bonardi et al. (1988), ora a quello della cartografia ufficiale 1:100.000 (boni et al., 1969). più recentemente, gallicchio et al. (2002) analizzando il settore pedemontano del tavoliere (dall’appennino fino all’area di lucera, appena a sud dell’area qui analizzata) riconoscono unicamente depositi terrazzati continentali (pleistocene medio-superiore) in erosione direttamente sulle argille subappennine. 145evidenze di neotettonica ... i rilevamenti condotti per la realizzazione del foglio n° 396 "san severo" (scala 1:50.000) hanno consentito sia di meglio definire le aree di affioramento delle unità basali della fossa bradanica (calcarenite di gravina ed argille subappennine), sia di proporre un nuovo schema stratigrafico per i depositi del pleistocene medio-superiore. 3. la fase di subsidenza del pliocene medio – pleistocene inferiore 3.1 dati stratigrafici la calcarenite di gravina (pliocene medio-superiore) la calcarenite di gravina rappresenta l’unità basale della successione plio-pleistocenica della fossa bradanica (ciaranfi et al., 1988). è conservata in lembi nel settore nord-occidentale dell’area di studio, ad est dell’abitato di apricena e nel settore nord-orientale del foglio san severo in località monte granata (fig. 2). il limite inferiore della calcarenite di gravina è inconfome; a seconda della locale strutturazione del substrato, tale formazione poggia in discordanza o in paraconcordanza sia sui calcari mesozoici (giurassico superiorecretaceo superiore) che sui calcari del miocene (serravalliano-tortoniano). la base della calcarenite di gravina corrisponde ad una netta superficie di ravinement su cui poggia un deposito conglomeratico grossolano spesso circa 40-50 cm, costituito da clasti carbonatici derivanti dal substrato locale, profondamente bioerosi e di dimensioni variabili da pochi centimetri a qualche decimetro immersi in una matrice biocalcarenitica con tessitura packstone/grainstone in cui si riconoscono frammenti di bivalvi, echinidi, foraminiferi bentonici ed alghe calcaree. il deposito lito-bioclastico basale passa gradualmente verso l’alto a strati e banchi calcarenitici e calciruditici dal tipico colore giallo-ocra a luoghi clinostratificati e costituiti in prevalenza da un deposito bioclastico con tessitura grainstone/rudstone in cui si riconoscono frammenti di gusci, abrasi e in alcuni casi ben selezionati, di bivalvi, echinidi, gasteropodi, foraminiferi bentonici e rodoliti. la frazione terrigena, costituita da elementi litici millimetrici o centimetrici derivanti dall’erosione del substrato, è presente, ma tende gradualmente a diminuire verso l’alto. le superfici di strato sono poco evidenti e delimitano strati e banchi di spessore variabile da 30 cm a 2÷3 metri con giacitura sub-orizzontale. la porzione superiore della calcarenite di gravina presenta caratteristiche di facies piuttosto omogenee. infatti, si riconoscono biocalcareniti e biocalciruditi intensamente bioturbate con tessitura packstone e più raramente grainstone costituite da abbondanti macrofossili, a luoghi intensamente bioerosi, tra cui lamellibranchi, briozoi, balani, alghe calcaree coralline (lithophyllum e lithothamnium), foraminiferi bentonici (abbondanti amphistegine ed elphidium) e planctonici. la frazione terrigena di tale deposito è molto scarsa o del tutto assente. nel complesso, le facies descritte indicano che questa formazione si è depositata in ambienti marini neritici che gradualmente evolvono verso l’alto dalla beachface alla shoreface in relazione ad una graduale tendenza all’approfondimento com’è evidenziato dalle strutture sedimentarie, dalla 146 fig. 2 carta e sezione geologica dell’area di studio. e’ riportato anche lo schema stratigrafico dei depositi del supersintema del tavoliere delle puglie (pleistocene medio-superiore). geologic map and section of the study area. the stratigraphic sketch of the tavoliere delle puglie supersynthem (middle-upper pleistocene) is shown. progressiva diminuzione della frazione terrigena derivante dall’erosione del substrato e dalla chiara tendenza fining upward. l’analisi micropaleontologica ha permesso di riconoscere la seguente associazione fossilifera di foraminiferi planctonici globigerinoides quadrilobatus, globigerina bulloides, globigerinoides ruber e neogloboquadrina acostaensis, attribuibile genericamente al pliocene medio-superiore (sprovieri, 1993). questi dati collimano con quelli di d’alessandro et al. (1979) che, nelle stesse aree di studio ed anche in aree limitrofe, hanno attribuito la calcarenite di gravina al pliocene medio-superiore sia per il contenuto macropaleontologico che per quello micropaleontologico. le argille subappennine (pliocene medio pleistocene inferiore) la formazione delle argil le subappennine (azzaroli, 1968) è costituita da un complesso di depositi argillosi, sabbiosi e siltosi depositatosi tra il pliocene medio ed il pleistocene inferiore nel bacino della fossa l. spalluto & m. moretti 147 bradanica. le argille subappennine affiorano in un’area molto ristretta nel settore sud-occidentale del foglio 1:50.000 n° 396 san severo (fig. 2) per uno spessore di circa 1520 m, ma, va sottolineato, costituiscono il substrato delle numerose unità pleistoceniche in tutto il settore di avanfossa (fig. 2), come si ricava dalle stratigrafie di numerosi pozzi per acqua perforati nell’area. i principali caratteri litologici e sedimentologici sono osservabili solo in aree limitrofe, ma esterne al foglio stesso (aree poste a ovest, alto morfologico di torre fiorentina). in queste aree le argille subappennine sono costituite da strati e banchi di silt argillosi con spessori variabili da qualche decina di centimetri ad oltre un metro. litologicamente sono costituite da argille siltose fortemente bioturbate che si alternano ad argille marnose, silt e sabbie da fini a grossolane di colore grigio-scuro. nell’area di interesse per meglio caratterizzare le unità plio-pleistoceniche sono stati perforati tre pozzi a carotaggio continuo. in carota, le argille subappennine sono caratterizzate da alternanze centimetriche e decimetriche tra argille siltose, silt e sabbie fini di colore grigio scuro. la laminazione è generalmente piano-parallela, incrociata solo negli intervalli sabbiosi; la bioturbazione è molto diffusa e a luoghi oblitera completamente le strutture sedimentarie primarie. si rinvengono numerosi resti di bivalvi e serpulidi sia in frammenti che interi. i dati di profondità disponibili in letteratura (pozzo agip san severo 1 bis – agip, 1977; balduzzi et al., 1982; casnedi, 1982; sella et al., 1988) indicano che le argille subappennine presentano spessori variabili da poche decine di metri nel settore di tavoliere prossimo al gargano, fino ad uno spessore massimo di circa 1000 metri nel settore sud-occidentale dell’area di studio (fig. 2). lo spessore è condizionato dall’assetto tettonico profondo del substrato meso-cenozoico. i dati provenienti dagli affioramenti ed i caratteri sedimentologici desunti dalle carote permettono di interpretare le argille subappennine come il risultato della sedimentazione, essenzialmente silicoclastica, in ambienti marini di piattaforma esterna. tale indicazione conferma quanto desumibile in letteratura per aree l imitrofe (gallicchio et al ., 2002; d’alessandro & la perna, 2004). sulla base delle associazioni a nannofossili calcarei l’unità è riferibile al pleistocene inferiore, per la presenza di rare “medium” gephyrocapsa (sensu rio et al., 1990); l’associazione non consente una più precisa attribuzione biozonale ed è rappresentata principalmente da pseudoemiliania lacunosa (kamptner), calcidiscus leptoporus (murray & blackman), “small” gephyrocapsa (sensu rio et al., 1990), reticulofenestra spp., rare helicosphaera sellii bukry & bramlette. 3.2 evidenze di tettonica nell’intervallo pliocene medio – pleistocene inferiore oltre che dall’evoluzione stratigrafica, la tettonica connessa a questa fase di subsidenza è ben registrata anche da numerose faglie distensive la cui attività è sinsedimentaria rispetto alla deposizione della calcarenite di gravina (pliocene medio-superiore); nell’area ad ovest di apricena (località masseria zingari), la presenza di numerose sezioni stratigrafiche lungo tagli variamente orientati della nuova linea ferroviaria e di quella dismessa consente di seguire e mappare accuratamente i principali elementi strutturali; inoltre la presenza di affioramenti di depositi di età variabile dal miocene medio al pleistocene medio consente di datare in modo preciso l’attività di tali faglie. lungo i nuovi tagli della ferrovia è possibile osservare alcune faglie dirette ad attività sinsedimentaria in relazione alla deposizione della calcarenite di gravina (pliocene medio-superiore). si tratta di stretti semigraben (qualche decina di metri in ampiezza) che tagliano i calcari miocenici e presentano chiare strutture di “crescita” nella calcarenite di gravina (pieghe per propagazione di faglia). a luoghi, in corrispondenza di tali faglie, si osservano anche blocchi di calcari miocenici franati all'interno della calcarenite di gravina che probabilmente indicano la presenza di falesie instabili proprio fig. 3 esempio di tettonica distensiva connessa alla fase di subsidenza del pliocene – pleistocene inferiore. le faglie dirette tagliano localmente la calcarenite di gravina (pliocene medio-superiore), ma sono suturate dal subsintema di colle degli ulivi (pleistocene medio). example of the pliocene – lower pleistocene subsidence phase. extensional faults cut the calcarenite di gravina fm. and are suturated by the colle degli ulivi subsynthem. evidenze di neotettonica ... 148 lungo tali strutture tettoniche. l'attività sinsedimentaria di tali semigraben è testimoniata dal brusco aumento di spessore delle calcareniti plioceniche in corrispondenza delle faglie stesse. il rigetto imputabile all'attività pliopleistocenica sembra diminuire verso l'alto ed è comunque al massimo di pochi metri (5÷6 m il rigetto massimo osservato). le faglie descritte sono inoltre suturate dai depositi marini del pleistocene medio che si rinvengono in pinch-out sia sulla calcarenite di gravina che sui calcari miocenici (fig. 3). in corrispondenza del taglio della ferrovia dismessa sono stati osservati altri effetti di tettonica pliocenica. l'attività sinsedimentaria è testimoniata da intensi piegamenti negli strati della calcarenite di gravina, sia lungo i piani di faglia principali che lungo piani secondari. si osserva una faglia diretta principale (f1 in fig. 4) che mette in contatto tettonico i calcari del miocene e la calcarenite di gravina: il movimento è suggerito chiaramente dall’uncinatura verso l'alto degli strati di calcarenite di gravina; localmente si osservano anche bruschi aumenti di spessore degli strati della calcarenite pliocenica lungo tale faglia che testimoniano un’attività anche sinsedimentaria della stessa. alla faglia principale è però associata una faglia con chiari caratteri di rigetto inverso (si osservi l’uncinatura degli strati verso la faglia f2 in fig. 4). l'associazione di faglie dirette principali e faglie inverse “coniugate” viene spesso spiegata in termini di effetti locali di transtensione o transpressione lungo elementi strutturali con movimento essenzialmente trascorrente (fiori negativi o positivi). un’altra possibile interpretazione è legata all’osservazione che la tettonica distensiva su sistemi complessi formati da un substrato rigido sul quale è presente una copertura sedimentaria poco diagenizzata (si vedano i modelli proposti da withjack et al., 1990 e hardy & mcclay, 1999) porta alla formazione di strutture tettoniche molto simili a quelle osservate in affioramento (f1 ed f2 in fig. 4). in entrambi i casi si tratta di una evidenza di tettonica sinsedimentaria nella calcarenite di gravina che mostra chiari effetti di deformazione tettonica in condizioni di soft-sediment. infine un'ultima evidenza di tettonica sinsedimentaria è rappresentata dalla presenza di numerosi “filoni nettuniani” al contatto fra i calcari miocenici e la calcarenite di gravina (fig. 5). si tratta di profonde fratture distensive nel substrato rigido dei calcari miocenici (lunghe fino a 6 m) all'interno delle quali viene “risucchiata” la calcarenite di gravina. la deformazione è sempre sinsedimentaria (rispetto alla deposizione della calcarenite di gravina) in quanto il termine superiore si deforma in condizioni non-consolidate (soft-sediment deformation) ed interi strati vengono “risucchiati” e/o piegati dalla deformazione distensiva fragile del substrato. non sono invece state evidenziate strutture tettoniche con attività infrapleistocenica. 4. la fase di uplift del pleistocene medio superiore 4.1 dati stratigrafici i depositi delle argille subappenine sono delimitati al tetto da una serie di superfici erosive su cui poggiano fig. 4 a e b: tettonica sinsedimentaria pliocenica lungo la ferrovia dismessa (apricena). la faglia principale f1 è diretta (uncinatura verso l'alto degli strati di calcarenite di gravina) e presenta attività sinsedimentaria rispetto alla deposizione della calcarenite di gravina (piccole variazioni di spessore verso la faglia). alla faglia f1 principale è associata una faglia f2 a rigetto inverso (si osservino le uncinature). c: modello analogico di deformazione di una copertura sedimentaria poco diagenizzata al di sopra di un substrato rigido soggetto a distensione (da hardy & mcclay, 1999 modificato). si noti la formazione di faglie inverse (*). a and b: pliocene synsedimentary tectonics in the apricena area. master fault (f1) shows a normal displacement. the f2 fault shows a clear compressional displacement. c: results of laboratory experiments on extensional faults affecting a soft-sediment sedimentary cover (modified from hardy & mcclay, 1999). note the presence of reverse faults (*). l. spalluto & m. moretti depositi litologicamente e tessituralmente eterogenei attribuibili sia ad ambienti marini costieri che ad ambienti alluvionali. nel corso del rilevamento sono stati distinti sei differenti sintemi terrazzati distribuiti, dal più antico al più recente, a quote decrescenti (fig. 2): 6) sintema di masseria finamondo (pleistocene superiore); 5) sintema di motta del lupo (pleistocene superiore); 4) sintema di foggia (pleistocene superiore); 3) sintema di masseria la motticella (pleistocene medio – superiore?); b) subsintema di masseria de grossi; a) subsintema de il casone; 2) sintema di vigna bocola (pleistocene medio); b) subsintema di masseria pallante; a) subsintema di san severo; 1) sintema di cava petrilli (pleistocene medio); b) subsintema di masseria casillo; a) subsintema di colle degli ulivi. i tre sintemi più antichi (sintema di cava petrilli, sintema di vigna bocola e sintema di masseria la motticella) sono stati suddivisi in due subsintemi separati da una superficie di erosione che mette a contatto depositi marini che mostrano un trend regressivo ed i sovrastanti depositi in facies continentale alluvionale. i tre sintemi più recenti (sintema di foggia, sintema di motta del lupo e sintema di masseria finamondo) sono costituiti essenzialmente da successioni continentali. i tre subsintemi marini (subsintema di colle degli ulivi, subsintema di san severo e subsintema de il casone) hanno uno spessore di circa 30-35 m, affiorano in lembi nell’area di studio e, con la sola eccezione del subsintema di colle degli ulivi ben visibile in alcune trincee ferroviarie, i caratteri di facies sono stati osservati prevalentemente attraverso l’esecuzione di apposite perforazioni a carotaggio continuo. il subsintema di colle degli ulivi è costituito dal basso verso l’alto, da: alternanze tra argille con laminazione piano-parallela e sabbie a laminazione incrociata con intercalazioni di livelli ghiaiosi formati alla base da letti di clay-chips provenienti dall’erosione del substrato argilloso; sabbie con stratificazione incrociata formanti foresets progradanti verso ne e strette forme erosive canalizzate riempite da sabbie a stratificazione incrociata; alternanze fra conglomerati e sabbie con i conglomerati che aumentano in spessore, dimensioni dei ciottoli e frequenza verso l’alto dove mostrano forme canalizzate. l’insieme dei caratteri descritti indica che il subsintema di colle degli ulivi si è depositato in un ambiente marino transizionale di delta passante lateralmente ad ambienti di mare sottile. i corpi ghiaiosi caratterizzavano i canali attivi del delta e sfumavano lateralmente in corpi sabbiosi progradanti verso ne sui depositi prevalentemente argillosi di prodelta. la successione verticale e laterale delle facies indica chiaramente che il subsintema di colle degli ulivi mostra un trend regressivo. il subsintema di san severo ed il subsintema de il casone sono costituiti, dal basso verso l’alto, da: alternanze argilloso-sabbiose a luoghi con lamine piano-parallele, intensamente bioturbate e con abbondante contenuto in materia organica; sabbie giallastre ben selezionate e a luoghi bioturbati con interstrati siltoso-argillosi che aumentano in spessore e frequenza verso l’alto; argille brune e verdi bioturbate con rare lamine siltoso-sabbiose; argille verdastre con abbondante presenza di concrezioni calcaree di origine diagenetica, sabbie da medie a fini ben selezionate e a laminazione incrociata passanti in alto ad argille brunastre a laminazione piano-parallela. tutti i caratteri di facies indicano che tali subsintemi si sono depositati in ambienti marini costieri di baia più o meno protetta. si 149 fig. 5 dicchi nettuniani al contatto fra i calcari del miocene e la sovrastante calcarenite di gravina. sono rappresentati da fratture di forma conica impostate nel substrato miocenico riempite dalle sovrastanti calcareniti plioceniche. si noti la deformazione tipo “soft-sediment” nella calcarenite di gravina e la deformazione fragile del substrato miocenico. neptunian dykes at the contact between the miocene limestones formation and the overlying calcarenite di gravina formation. they are represented by large conical fractures in the miocene substratum which are filled by the overlying pliocene calcarenites; note the soft-sediment deformation in the calcarenite di gravina fm. and the extensional brittle deformation of the substratum. evidenze di neotettonica ... tratta di una successione marina e di transizione con un generale trend regressivo. la base trasgressiva è rappresentata da alternanze argilloso-siltoso-sabbiose deposte in shoreface superiore in una baia molto protetta e con scarsa circolazione costiera. la parte superiore è invece costituita da sabbie da grossolane a fini di ambienti relativamente più profondi (shoreface inferiore) in un contesto di baia aperta. verso l’alto si torna a condizioni di baia ristretta fino alle sabbie a laminazione incrociata ed alle argille brunastre che probabilmente rappresentano già ambienti di transizione al continentale. il subsintema di masseria casillo, il subsintema di masseria pallante ed il subsintema di masseria de grossi poggiano in erosione sui subsintemi marini sottostanti e presentano caratteri litologici molto simili tra loro. in particolare, sono costituiti da conglomerati poligenici con abbondante matrice sabbiosa rossastra. i ciottoli presentano una bassa selezione granulometrica ed il diametro massimo è prossimo a 30 cm. si presentano mal stratificati e, solo a luoghi, è possibile riconoscere superfici erosive canalizzate. l’ambiente di sedimentazione è riferibile in base ai dati sedimentologici ad una piana braided. lo spessore massimo di questi subsintemi è nell’ordine dei 10-15 m. la base dei tre sintemi più recenti (sintema di foggia, sintema di motta del lupo e sintema di masseria finamondo non è mai visibile in affioramento, rappresentata, come si ricava dai dati di pozzo per i sintemi di motta del lupo e masseria finimondo, da un paio di metri di depositi marini (sabbie fini ben selezionate con abbondante contenuto in microfossili). verso l’alto, questi depositi sono costituiti da: alternanze tra ghiaie poligeniche con ciottoli di dimensioni centimetriche e sabbie con associata terra rossa; argille brune con lamine piano-parallele e con intercalazioni siltososabbiose a luoghi con ripples asimmetrici e laminazione incrociata a basso angolo ed abbondante contenuto in terra rossa; argil le nerastre cementatissime prive di strutture sedimentarie e si lt con abbondanti concrezioni calcaree di origine diagenetica. i residui di lavato contengono rari frammenti di macrofossili, ostracodi, oogoni di alghe carofite o rarissimi foraminiferi rotti ed abrasi ed in alcuni casi sono risultati sterili. questi sintemi mostrano un trend chiaramente regressivo: su sabbie marine, si rinvengono sia argille, sabbie e ghiaie di ambiente alluvionale con condizioni idrodinamiche anche di moderata energia, che argille brune e verdi di palude e/o di laguna ristretta in cui si potevano depositare grandi quantità di materia organica. 4.2 evidenze di tettonica nell’intervallo pleistocene mediosuperiore l’eventuale presenza di strutture tettoniche ad attività sinsedimentaria associate a questa fase sono meno documentabili a causa della mancanza di estesi affioramenti dei depositi medio e supra pleistocenici. ciononostante, i subsintemi marini più antichi e meglio affioranti (subsintema di colle degli ulivi e subsintema di san severo) mostrano chiari indizi di tettonica sinsedimentaria e sono dislocati nel settore nord-occidentale dell’area analizzata (area a n e no di apricena). in località cava di nunzio (fig. 6) è stata documentata la presenza di una faglia diretta subverticale che taglia per intero la successione marina di transizione dei depositi del subsintema di colle degli ulivi con un rigetto di circa 20 m: la sua attività è chiaramente successiva alla sedimentazione della stessa unità marina (pleistocene medio). l’andamento è circa e-o e non sono stati osservati indicatori cinematici. ad ovest dell’abitato di apricena, lungo la nuova trincea ferroviaria, sono visibili due faglie subverticali a rigetto diretto (rigetto massimo misurato nell’ordine dei 6-7 m) che interessano il subsintema di san severo (pleistocene medio). la faglia diretta più meridionale mette in contatto tettonico le facies sabbiose che caratterizzano la porzione basale dell’unità con le argille brune e verdi che si rinvengono nella porzione centrale e superiore della successione (fig. 7). anche in questo caso l’andamento delle faglie è e-o e l’attività è postpleistocene medio. 5. deduzioni tettoniche e paleogeografiche i dati stratigrafici e tettonici esposti permettono di delineare i punti principali dell’evoluzione sedimentaria e strutturale plio-pleistocenica di questo settore del tavoliere delle puglie nel plio-pleistocene. le evidenze della tettonica connessa alla fase di subsidenza dell’avampaese apulo (pliocene medio150 fig. 6 evidenze di tettonica durante la fase di sollevamento del pleistocene medio-superiore. evidences of tectonics during the middle-upper pleistocene uplift phase. l. spalluto & m. moretti pleistocene inferiore) sono registrate dal punto di vista stratigrafico nell’area di interesse dal progressivo annegamento di vasti settori dell’avampaese apulo. il trend trasgressivo legato a questa fase è registrato nell’area di studio dalla sedimentazione della calcarenite di gravina che mostra una chiara evoluzione del tipo fining/deepening upward nella successione verticale delle facies. la fase di subsidenza continua anche nel pleistocene inferiore ed è marcata dalla sedimentazione delle argille subappennine che, nell’area di studio, è costituita da fanghi e silt emipelagici attribuibili ad ambienti di piattaforma esterna. queste ultime raggiungono spessori notevoli (fino a 1000 m da dati di pozzo) al di sopra della monoclinale regionale che si immerge al di sotto dell'appennino. dal punto di vista strutturale, la subsidenza è documentata da faglie dirette orientate circa est-ovest con attività sinsedimentaria in relazione alla deposizione della calcarenite di gravina. le strutture riconosciute interessano esclusivamente la calcarenite di gravina senza trasferirsi alle sovrastanti argille subappennine: tale dato sembra indicare che gli effetti della tettonica distensiva nel settore in esame si risentano solo nella fase di incipiente passaggio da area di avampaese ad area di avanfossa subsidente. l'insieme dei caratteri stratigrafici e strutturali esposti per il supersintema del tavoliere delle puglie mostra che esso costituisce un insieme complesso di depositi marini e continentali che segnano l’evoluzione stratigrafico-strutturale di questo settore del tavoliere a partire dal pleistocene medio fino all’attuale. in particolare, nell'area di studio la fase di sollevamento è segnata dalla presenza di sintemi e subsintemi terrazzati in facies marina costiera e continentale che marcano la graduale riemersione di questo settore di transizione fra l'avampaese apulo e l’avanfossa. il progressivo sollevamento dell'area in esame può essere desunto oltre che dalla distribuzione altimetrica dei depositi, anche dallo studio dei caratteri evolutivi dei singoli sintemi o subsintemi che costituiscono il supersintema del tavoliere delle puglie. il subsintema di colle degli ulivi è rappresentato da corpi deltizi progradanti verso ne, mentre i subsintemi di san severo e del casone si sviluppano in ambienti di bassa energia tipo baia. tale dato indica la presenza di una paleolinea di costa orientata approssimativamente no-se nel caso del subsintema di colle degli ulivi. viceversa, i depositi marini dei subsintemi più recenti (subsintema di san severo e subsintema de i l casone) si depositavano in un’area protetta tipo baia che, dal punto di vista paleogeografico, era rappresentata da linee di costa parallele all’attuale golfo di manfredonia distribuite via via a quote decrescenti. inoltre analizzando e confrontando i caratteri litologici dei depositi marini e continentali è possibile affermare che i corpi deltizi progradanti del subsintema di colle degli degli ulivi erano associati ad un corso d’acqua (il paleofortore secondo aucelli et al., 1997) che aveva un reticolo idrografico ed un’area di alimentazione che si estendevano in aree interne del subappennino dauno. i clasti del subsintema di colle degli ulivi sono infatti poligenici e sono rappresentati da una gran varietà di litologie (rocce intrusive, arenarie, calcari, selci, ecc.) alcune delle quali sono presenti unicamente nel flysch di san bartolomeo (che non affiora nel settore esterno del subappennino dauno). viceversa tutti i depositi alluvionali terrazzati dei sintemi o subsintemi più recenti contengono unicamente clasti che provengono dal settore esterno dell’appennino (con area di alimentazione coincidente con quella degli attuali corsi d’acqua) nel quale affiorano prevalentemente unità calcaree (flysch di faeto e flysch rosso). l’insieme di questi dati mostra che nel pleistocene medio vi è stato un intenso sollevamento dell’area posta a nord del settore analizzato. al sollevamento di quest’area sono probabilmente associate le faglie che sono state descritte precedentemente nei depositi del pleistocene medio-superiore. tale sollevamento, che coincide parzialmente con quello descritto da aucelli et al. (1997) in settori limitrofi all’area qui analizzata, deve essere avvenuto infatti lungo strutture tettoniche orientate circa e-o ed in grado di isolare un settore settentrionale direttamente connesso all’adriatico (l’attuale valle del fortore), da uno meridionale tipo baia sviluppatosi parallelamente all’attuale golfo di manfredonia. la distribuzione altimetrica dei sintemi appartenenti al supersintema del tavoliere delle puglie mostra che il sollevamento caratterizza tutti i depositi dal pleistocene medio all’attuale. tale considerazione ricalca quanto ricavato, in un settore del tavoliere a so dell’area qui considerata, da gallicchio et al. (2002). nel settore pedemontano del tavoliere infatti, i l supersintema del tavoliere delle puglie è caratterizzato solo da depositi continentali (attribuibili a sistemi alluvionali di conoide e braided): i depositi di conoide più antichi sembrano svilupparsi su ampie superfici che si estendono ininterrottamente, da o verso e, dalla catena fino all’area di lucera; nel tempo ciascun alveo si è approfondito confinando via via sistemi di conoide passanti distalmente a sistemi di tipo braided in valli allungate all’incirca e-o. nell’area rappresentata nel foglio san severo affiorano i sintemi meno elevati e più recenti appartenenti a questo supersintema. la differenza sostanziale rispetto al settore pedemontano descritto precedente151 fig. 7 faglie connesse al sollevamento. faglia diretta che taglia il subsintema di san severo (pleistocene medio). faults related with the uplift phase. extensional fault that cuts the san severo subsynthem (middle-pleistocene). evidenze di neotettonica ... mente risiede nella presenza (nei sintemi più antichi affioranti) dei depositi marini. nel settore pedemontano del tavoliere i depositi marini sono stati erosi (se ne ritrovano tracce nei clasti dei depositi continentali dei sintemi più antichi). nel settore orientale del tavoliere delle puglie (ricadente nell’area qui analizzata) i depositi marini sono stati invece localmente preservati dall’erosione. tale differenza potrebbe essere connessa sia al maggiore spessore che i depositi marini potevano avere in questo settore sia al presumibile maggior grado di erosione che essi dovevano subire nel settore pedemontano (a parità di tassi di sollevamento e di sedimentazione). inoltre, la presenza di sintemi continentali più antichi ed a quote maggiori ed il fatto che alcuni subsintemi continentali poggino sia sulle argille subappennine che sui subsintemi marini porta a ritenere che questi ultimi probabilmente si depositavano all’interno di valli incise, durante periodi di ingressione marina in un trend generale regressivo indotto dal sollevamento. 6. conclusioni nel corso dei rilevamenti per la nuova carta geologica d'italia (scala 1:50.000), foglio n° 396 "san severo", sono stati riconosciuti numerosi elementi strutturali con evidenze di attività neotettonica (pliocene medio pleistocene superiore). i caratteri della deformazione tettonica ed i vincoli stratigrafici hanno permesso di riconoscere due distinte fasi di tettonica distensiva: una relativa al pliocene medio – pleistocene inferiore, l'altra attiva a partire dal pleistocene medio. le strutture tettoniche connesse alla subsidenza del pliocene medio – pleistocene inferiore confermano quanto noto in letteratura per l’area di avanfossa a sud dell’ofanto. in particolare gli effetti di tettonica sinsedimentaria nella calcarenite di gravina presentano caratteri molto simili a quelli descritti da tropeano et al. (1994) lungo il margine sud-occidentale delle murge (area a so di matera). il sollevamento, in atto a partire pleistocene medio, è registrato dai depositi marini e continentali appartenenti al supersintema del tavoliere delle puglie che si rinvengono, dal più antico al più recente, a quote via via decrescenti sul livello del mare. il sollevamento è accompagnato dall'attività di faglie dirette, documentata nel settore nord-occidentale dell'area investigata. lo studio di dettaglio della stratigrafia dei depositi del pleistocene medio-superiore ha consentito di evidenziare non solo la presenza di faglie con attività successiva al pleistocene medio, ma anche di valutare con buona approssimazione i relativi rigetti. ringraziamenti si ringraziano: piero pieri e giustino ricchetti per il coordinamento e per la direzione scientifica dei lavori di rilevamento geologico del foglio 396 “san severo” (progetto c.a.r.g. puglia); patrizia maiorano e fabrizio lirer per le analisi biostratigrafiche delle unità plio-pleistoceniche; marcello tropeano e vincenzo festa per le proficue discussioni sul tema della tettonica plio-pleistocenica; i due referees per gli utili suggerimenti. lavoro pubblicato con fondi di ateneo miur ex 60% 2003-2004 (resp. l. sabato). bibliografia citata aucelli p.p.c., cinque a. & robustelli g. (1997) evoluzione quaternaria del tratto di avanfossa appenninica compreso tra larino (campobasso) e apricena (foggia). dati preliminari. il quaternario, 10, 453-460. azzaroli a. (1968) calcarenite di gravina. studi illustrativi della carta geologica d’italia – formazioni geologiche. servizio geologico d’italia, i, 183185. balduzzi a., casnedi r., crescenti u., mostardini f. & tonna m. (1982) il plio-pleistocene del sottosuolo del bacino lucano (avanfossa appenninica). geol. romana, 21, 89-111. bertotti, g., casolari, e. & picotti, v. (1999) the gargano promontory: a neogene contractional belt within the adriatic plate. terra nova, 11, 168173. boenzi f., caldara m. & pennetta l. (1992) osservazioni stratigrafiche e geomorfologiche nel tratto meridionale della piana costiera del tavoliere di puglia. geogr. fis. dinam. quat., 14, 23-31. bonardi g., d’argenio b. & perrone v. (1988) carta geologica dell’appennino meridionale. scala 1:250.000. cnr/cartografia selca. roma/ firenze. boni a., casnedi r., centamore e., colantoni p., cremonini g., elmi c., monesi a., selli r. & valletta m. (1969) note illustrative alla carta geologica d’italia. f° 155 “san severo”, 46 pp. borre k., cacon s., cello g., kontny b., kostak b., lykke-andersen h., moratti g., piccardi l., stemberk j. & tondi e. (2003) the cost project in italy: analysis and monitoring of seismogenic faults in the gargano and norcia areas (centralsouthern apennines, italy). journal of geodynamics, 36, 3-18. caldara m. & pennetta l. (1989) dati preliminari sul tetto delle argille subappennine nel tavoliere meridionale. studi geologici e geofisici sulle regioni pugliese e lucana, 33, 16 pp. caldara m. & pennetta l. (1993) nuovi dati per la conoscenza geologica e morfologica del tavoliere di puglia. bonifica, 8, 25-42. capuano n., pappafico g. & augelli g. (1996) ricostruzione dei sistemi deposizionali plio-pleistocenici del margine settentrionale dell’avanfossa pugliese. mem. soc. geol. it, 51 (1), 273-293. casnedi r., crescenti u. & tonna m. (1982) evoluzione della avanfossa adriatica meridionale nel pliopleistocene, sulla base di dati di sottosuolo. mem. soc. geol. it., 24, 243-260. chilovi, c., de feyter, a.j. & pompucci, a. (2000) wrench zone reactivation in the adriatic block: the example of the mattinata fault system (se italy). boll. soc. geol. it. 119, 3-8. ciaranfi n., ghisetti f., guida m., iaccarino g., lambiase s., pieri p., rapisardi l., ricchetti g., torre m., tortorici l. e vezzani l. (1983) carta 152 l. spalluto & m. moretti neotettonica dell'italia meridionale. pubbl. n°515 prog. fin. geod. c.n.r., 62 pp. ciaranfi n., maggiore m., pieri p., rapisardi l. ricchetti g. & walsh n. (1979) considerazioni sulla neotettonica della fossa bradanica. contr. prel. realiz. carta neotettonica d’italia. pubbl. n° 251 del p. f. geodinam., 73-95. ciaranfi n., pieri p. & ricchetti g. (1988) note alla carta geologica delle murge e del salento (puglia centromeridionale). mem. soc. geol. it., 41, 449460. cremonini g., elmi c. & selli r. (1971) note illustrative della carta geologica d'italia alla scala 1: 100.000 foglio 156 "s. marco in lamis”, 65 pp. d’alessandro a., laviano a., ricchetti g. & sardella a. (1979) il neogene del monte gargano. boll. soc. geol. it., 18, 9-116. d’alessandro & la perna (2004) the “cocooned” mytilid amygdalum (bivalvia), palaeontological observations from the upper pliocene. rivista italiana di paleontologia e stratigrafia, 110(3): 725-731. d'argenio b. (1974) le piattaforme carbonatiche periadriatiche. una rassegna di problemi nel quadro geodinamico mesozoico dell'area mediterranea. mem.soc.geol.it.vol. 13, p. 137-160. d'argenio b., pescatore t. & scandone p. (1973) schema geologico dell'appennino meridionale (campania e lucania). in: "moderne vedute sulla geologia dell'appennino". acc. naz. dei lin., quad., 183, 49-72. doglioni c., mongelli f. & pieri p. (1994) the puglia uplift (se italy): an anomaly in the foreland of the apenninic subduction due to buckling of a thick continental lithosphere. tectonics, 13, 5,13091321. doglioni c., tropeano m., mongelli f., pieri p. (1996) middle-late pleistocene uplift of puglia: an anomaly in the apenninic foreland. mem. soc. geol. it., 51, 101-117. funiciello r., montone p., salvini f. & tozzi m. (1988) caratteri struturali del promontorio del gargano. mem. soc. geol. it., 41, 1235-1243. gallicchio s., moretti m. & pieri p. (2002) i depositi continentali terrazzati (pleistocene medio-superiore) nel settore pedemontano del tavoliere delle puglie. fascicolo degli abstract della ix riunione del gruppo di sedimentologia del cnr, pescara, 21-22/10/2002, 46-47. gambini, r. & tozzi m. (1996) tertiary geodynamic evolution of the southern adria microplate. terra nova, 8, 593-602. hardy s. & mc clay k. (1999) kinematic modelling of extensional fault-progagation folding. journ. of struct. geol., 21, 695-702. jacobacci a., malatesta a., martelli g. & stampanoni g. (1967) note illustrative della carta geologica d’italia alla scala 1:100.000 foglio 163 lucera. 48 pp. merla g., ercoli a. & torre d. (1969) note illustrative della carta geologica d'italia alla scala 1: 100.000. foglio 164 "foggia", 22 pp. morsilli m., de cosmo p.d., bosellini a., luciani v. (2002) l’annegamento santoniano della piattaforma apula nell’area di apricena (gargano, puglia): nuovi dati per la paleogeografia del cretaceo superiore. fascicolo degli abstract della ix riunione del gruppo di sedimentologia del cnr, pescara, 21-22/10/2002, 63-64. patacca e. & scandone p. (2004) the 1627 gargano earthquake (southern italy): identification and characterization of the causative fault. journal of seismology, 8, 259-273. piccardi l. (1998) cinematica attuale, comportamento sismico e sismologia storica della faglia attiva di monte sant’angelo (gargano): la possibile rottura superficiale del “leggendario” terremoto del 493 d.c. geogr. fis. e dinam. quatern., 21, 155-166. piccardi l., ferreli l., michetti a.m., tondi e. & vittori e. (2004) paleoseismology analysis along the mattinata fault, apulia foreland, southern italy. special issue “active faults: analysis, processes and monitorino. in: piccardi l., tondi e. (eds.), studi geologici camerti, pp. 119-122. pieri p. (1980) principali caratteri geologici e morfologici delle murge. murgia sotterranea, bollettino gruppo speleo martinese, martina franca, 2, 1319. pieri p., sabato l. & tropeano m. (1996) significato geodinamico dei caratteri deposizionali e strutturali della fossa bradanica nel pleistocene. mem. soc. geol. it., 51, 501-515. pomar l. & tropeano m. (2001) the calcarenite di gravina formation in matera (southern italy)new insights for corse-grained large scale, cross-bedded bodies encased in offshore deposits. aapg bull., 85, 661-689. ricchetti g. (1967) lineamenti geologici e morfologici della media valle del fiume bradano. bol. soc. geol. it., 86, 607-622. ricchetti g. ( 1980) contributo alla conoscenza strutturale della fossa bradanica e delle murge. bol. soc. geol. it., 99, 421-430. ricchetti g., ciaranfi n., luperto sinni e., mongelli f. e pieri p. (1988) geodinamica ed evoluzione sedimentaria e tettonica dell'avampaese apulo. mem. soc. geol. it., 41, 57-82. rio d., raffi i. & villa g. (1990) pliocene-pleistocene distribution patterns in the western mediterranean. in kastens k.a., mascle j. et alii, (eds.). proceeding of odp, scient. results, 107, 513-533. sella m., turci c. & riva a. (1988) sintesi geopetrolifera della fossa bradanica (avanfossa della catena appenninica meridionale). mem. soc. geol. it., 41, 87-107. selli r. (1962) il paleogene nel quadro della geologia dell'italia centro-meridionale. mem. soc. geol. d'it., 3, 737-789. spalluto l. (2004) la piattaforma apula nel gargano centro-occidentale: organizzazione stratigrafica ed assetto della successione mesozoica di piattaforma interna. tesi di dottorato in scienze della terra. università degli studi di bari, 173 pp. sprovieri r., (1993) mediterranean pliocene biochronology: an high resolution record based on quantitative planktonic foraminifera distribution. riv. ital. paleontol. stratigr., 98, 61-100. tinti s., maramai a. & favali p. (1995) the gargano promontory: an important italian seismogenic-tsu153evidenze di neotettonica ... namigenic area. marine geology, 122, 227-241. tondi e., piccardi l., cacon s., kontny b. & cello g. (2005) structural and time constraints for dextral shear along the seismogenic mattinata fault (gargano, southern italy). journal of geodynamics, 40, 134-152. tropeano m., marino m. & pieri p. (1994) evidenze di tettonica distensiva plio-pleistocenica al margine orientale della fossa bradanica. l’horst di zagarella. il quaternario, 7 (2), 597-606. tropeano m. & sabato l. (2000) response of pliopleistocene mixed bioclastic-lithoclastic temperate-water carbonate systems to forced regression: the calcarenite di gravina formation, puglia, se italy. in: “sedimentary responses to forced regression” (d.hunt & r.l. gawthorpe, eds.), geol. soc. london, spec. publ., 171, 217-243. tropeano m., sabato l. & pieri p. (2002) filling and cannibalization of a foredeep: the bradanic trough (southern italy). in “sediment flux to basins: causes, controls and consequences” (s.j. jones and l.e. frostick, eds.), pp. 55-79. geol. soc. london, spec. publ., 191, 55-79. valduga a. (1973) fossa bradanica. in geologia dell’italia, a cura di desio a.., utet, 692-695. withjack m.o., olson j. & peterson e. (1990) experimental models of extensional forced folds. a.a.p.g. bull., 74, 1038-1045. 154 ms. ricevuto il 6 giugno 2006 testo definitivo ricevuto il 17 ottobre 2006 ms. received: june 6, 2006 final text received:october 17, 2006 l. spalluto & m. moretti impaginato forno lleemmbbii ddii ddeeppoossiittii fflluuvviiaallii pprroovveenniieennttii ddaaii bbaacciinnii aallppiinnii nnoorrddoocccciiddeennttaallii ssuullllaa ccoolllliinnaa ddii ttoorriinnoo pprreessssoo vviillllaa gguuaalliinnoo ((nnww iittaallyy)) mmaarriiaa ggaabbrriieellllaa ffoorrnnoo11,, ggiiuusseeppppee bbeenn22,, ppaaoollaa bbooaannoo11,, ppiieerrccaarrlloo bbooccccaa33,, vvaalltteerr bbooeerroo44 && rroobbeerrttoo ccoommppaaggnnoonnii55 1dipartimento di scienze della terra, università di torino 2servizi tecnici di prevenzione, regione piemonte 3libero professionista, c. regina margherita 1, torino 4dipartimento di valorizzazione e protezione delle risorse agroforestali, università di torino 5dipartimento di scienze mineralogiche e petrografiche, università di torino. riassunto il quaternario, italian journal of quaternary sciences gli studi più recenti riguardanti il versante occidentale della collina di torino evidenziano una successione di superfici pianeggianti terrazzate da riferire al modellamento fluviale del rilievo, realizzatosi in una situazione morfologica sensibilmente diversa dall’attuale. l’estrema antropizzazione dell’area collinare e la diffusione della copertura eolica ostacolano lo studio di queste superfici e in particolare rendono difficile valutare se, nei diversi casi, esse conservino o meno gli originari depositi alluvionali: la realizzazione di sondaggi in corrispondenza al lembo di superficie di villa gualino, sospeso di circa 130 m rispetto alla pianura, consente invece, in questo caso, di riconoscere nelle stratigrafie la successione fluviale, con spessore di circa 5m, interposta tra il substrato e il loess. in particolare la caratterizzazione geotecnica e lo studio dei campioni raccolti dal punto di vista tessiturale, mineralogico e pedologico, evidenziano come questi sedimenti si differenzino sia dai termini marini sottostanti, sia dalla soprastante copertura eolica. l’insieme delle osservazioni effettuate, pur limitate ad un singolo lembo di superficie terrazzata e quindi necessariamente da integrare con le osservazioni al contorno, indica per i depositi fluviali in esame una provenienza dall’antistante area alpina, con un particolare contributo dal bacino idrografico del f. dora riparia, in un intervallo di tempo precedente rispetto all’impostazione del f. po. le osservazioni pedologiche, in assenza di altri dati stratigrafici, indicano una attribuzione cronologica della successione fluviale alla parte superiore del pleistocene medio, in accordo con il riferimento al tardo pleistocene superiore già noto per il loess eolico. abstract remnants of fluvial deposits from northwestern alpine basins in the turin hills at villa gualino (nw italy). recent investigation on the western slope of the turin hills reveals a series of flat terraced surfaces produced by fluvial modelling occurred when morphological conditions were very different from the present. intense human occupation of the hillsides and diffusion of aeolian loess hinder the study of these surfaces and make it hard to determine whether they still retain the original alluvial deposits or not. stratigraphic examination of some boreholes made during rectructuring of villa gualino on a terraced surface (130 m above the po plain level) points out the presence of fluvial deposits in the immediate subsoil between the marine substratum and the aeolian cover. evidence in favour of this view is provided first of all by penetrometric tests of a cover 10-15 m thick of incoherent sediments, unusual for these hills. the stratigraphic data show the presence of an approximatively 5-m thick lenticular sandy to silty fluvial body that is distinct from the substratum and separated from it by an evident erosion surface. the concave shape of the base indicates the presence of a channel. the subhorizontal upper surface, on the other hand, points to the development of a strip of alluvial plain subjected to overspill flooding. moreover in the alluvial deposits fossils, which are abundant in the marine substratum, and bedding are lacking. textural and mineralogical data show that the grain size of fluvial deposits is much finer than substratum and less selected than loess, and that their mineral composition qualitatively and quantitatively is different. pedological data reveal a marked weathering different from that of both the substratum and the overlying loess. these observations point to a surface erosion earlier than the formation of the alluvial body and that significant time gap occurred before the loess deposition. in the absence of other stratighraphic data, the fluvial deposits can be assigned to the upper part of middle pleistocene in agreement with the accepted, late upper-pleistocene age of the aeolian loess. these observations are confined to a single strip of terraced surface and must be supplemented with further evidence from its surroundings. these preliminary results suggest that the fluvial deposits are derived from the facing mountain alpine area, especially from the hydrographic basin of the dora riparia river, prior the establishment of the po river. parole chiave: depositi fluviali, collina di torino, pleistocene medio. keywords: fluvial deposits, turin hills, middle pleistocene il quaternario italian journal of quaternary sciences 1155(2), 2002, 175-185 11.. iinnttrroodduuzziioonnee ee llaavvoorrii pprreecceeddeennttii villa gualino, ubicata sul versante occidentale della collina di torino alla quota di 352 m e compresa nel territorio comunale di torino (fig. 1), sorge su un lembo di superficie subpianeggiante sospesa di circa 130 metri rispetto all’incisione del po. la redazione del progetto di ristrutturazione degli edifici esistenti e di edificazione di nuovi fabbricati ha offerto l’opportunità di condurre una campagna geognostica finalizzata alla valutazione della stratigrafia dell’immediato sottosuolo e alla sua caratterizzazione geotecnica. nel corso della esecuzione di una prima serie di sondaggi e di prove penetrometriche continue, statiche e dinamiche, è emersa una situazione geologica locale del tutto particolare, non inquadrabile nel contesto stratigrafico tipico della collina di torino, contraddistinto in genere dal diffuso affioramento o subaffioramento della 176 m.g. forno et alii successione marina terziaria con una sottile coltre di loess eolico. tale situazione peculiare è riassumibile nello sviluppo di una copertura relativamente potente con caratteristiche geotecniche scadenti (figg. 2 e 3): lo spessore anomalo dei sedimenti incoerenti, variabile tra 10 e 15 m, poteva essere congruente con il modello interpretativo messo a punto attraverso i più recenti sviluppi delle ricerche geologiche sull’area collinare (boano & forno, 1997). scopo del presente lavoro (coordinato da m. g. forno) è quello di descrivere ed interpretare la successione di depositi che costituiscono in superficie il lembo di villa gualino e in particolare di verificare se alcuni termini di questa corrispondano a depositi fluviali analoghi a quelli segnalati localmente in corrispondenza ad altri lembi terrazzati conservati nel versante occidentale della collina di torino. con questa finalità, in seguito alle indagini geotecniche che hanno fornito lo spunto per questa ricerca (p. bocca), sono stati eseguiti il rilevamento geologico di dettaglio e la descrizione delle carote dei sondaggi (p. boano e m. g. forno) ed effettuate una serie di analisi tessiturali (g. ben), mineralogiche (p. boano e r. compagnoni) e pedologiche (v. boero). le interpretazioni sono frutto della discussione collegiale degli autori. la letteratura geologica sulla collina di torino riguarda quasi esclusivamente la successione marina terziaria del substrato: per l’area su cui sorge villa gualino il foglio 56 “torino” della carta geologica d’italia iia ed. (bortolami et al., 1969) e le relative note illustrative (bonsignore et al., 1969) riportano, al di sopra dei sedimenti marini del complesso di baldissero, una coltre discontinua di loess; la distribuzione di quest’ultimo e dei prodotti colluviali legati alla sua rielaborazione è stato oggetto di studi specifici (forno, 1979; 1990). e’ noto da tempo che l’impostazione del f. po a nord della collina di torino è di età molto recente (carraro, 1976); i precedenti andamenti del collettore del bacino piemontese meridionale (aa in fig. 1) sono conservati sul versante meridionale del rilievo collinare (carraro et al., 1982): le tracce di questo corso d’acqua corrispondono a relitti di meandri con raggio di curvatura chilometrico che conservano diffusamente gli originari sedimenti alluvionali prevalentemente siltosi e localmente ghiaiosi (forno, 1979; compagnoni & forno, 1992). solo recentemente (boano & forno, 1997) è stata segnalata la presenza di relitti di forme fluviali anche sul versante opposto, occidentale: queste sono rappresentate da una successione di superfici terrazzate relitte, sulle quali è conservata localmente una esigua copertura di depositi alluvionali. tali superfici sono distribuite in corrispondenza delle dorsali spartiacque del reticolato idrografico locale e appaiono allungate in direzione n-s, trasversalmente rispetto all’andamento di questo reticolato: i caratteri morfologici di questi lembi terrazzati suggeriscono il legame genetico con un importante corso d’acqua che convogliava i l drenaggio del bacino piemontese settentrionale (bb in fig. 1) prima dell’impostazione del f. po al margine settentrionale della collina di torino (boano & forno, 1997). la presenza delle tracce di antichi corsi d’acqua distribuite in una ampia fascia altimetrica sul versante esterno della collina di torino indica che quest’area, nell’intervallo di tempo precedente alla diversione del po, è stata interessata da un sensibile sollevamento recente a cui è connesso l’approfondimento del drenaggio (boano et al., 2000): il reticolato idrografico attuale ha successivamente dissecato queste forme, che risultano pertanto conservate in lembi di piccole dimensioni. 22.. iinnqquuaaddrraammeennttoo mmoorrffoollooggiiccoo ee ggeeoollooggiiccoo ddeellll’’aarreeaa il tratto del versante occidentale del rilievo collinare su cui insiste il complesso degli edifici di villa gualino, caratterizzato da un’acclività media sensibile (12 %), é interrotto, nella fascia altimetrica compresa tra 345 e 350 m, da un lembo di superficie con acclività fig. 1 ubicazione dell’area di studio nell’ambito del versante occidentale della collina di torino. location of the studied area on the western slope of the turin hills. sensibilmente inferiore (2 %), allungato per circa 300 m in direzione n-s. le osservazioni morfologiche consentono di ipotizzare che questo lembo pianeggiante, con estensione complessiva di circa 15.000 m2, sia parte di origine naturale e parte sia stato invece realizzato artificialmente, con un ampliamento della superficie originaria. in particolare il settore a quota inferiore, sviluppato tra 345 e 347 m, su cui sorgono gli edifici della fondazione gnocchi e del centro convegni di villa gualino (settore aa in figg. 2 e 4) risulta correlabile altimetricamente con altri lembi pianeggianti, interpretabili come relitti di un’unica superficie che mostra nel suo insieme una modestissima inclinazione verso nord, successivamente terrazzata (boano & forno, 1997). il settore a quota superiore, sviluppato tra 347 e 350 m, su cui sorgono la residenza di villa gualino e il piazzale antistante (settore bb in figg. 2 e 4), in più punti mostra di essere modellato in materiale di riporto e non risulta correlabile con altri lembi di superfici pianeggianti: tali elementi inducono a interpretarlo parte come una forma di accumulo artificiale sull’originaria prosecuzione del settore aa e parte come il prodotto dello spianamento artificiale di un tratto del versante soprastante. i dati geologici di superficie consentono una differenziazione anche dal punto di vista stratigrafico dell’area interpretabile come il lembo pianeggiante originario (fig. 4). in particolare nel settore aa si sviluppa una diffusa e potente copertura di loess eolico che impedisce le osservazione geologiche dell’immediato sottosuolo, rendendo la successione fluviale sottostante individuabile esclusivamente tramite i sondaggi (v. §3.): la coltre eolica mostra una tessitura siltosa, molto omogenea arealmente, porosità elevata e assenza di stratificazione; contiene diffusamente gusci di gasteropodi continentali. e’ interessata da un suolo di colore giallo-bruno (10yr 4/6), con spessore di alterazione superiore ai 2 m, in accordo con l’età tardo pleistocenica superiore (forno, 1979); caratteristica di questi sedimenti è inoltre l’evidente fessurazione prismatica. nel settore bb, al di sotto di una copertura di loess e di materiali di riporto, affiorano invece localmente prodotti colluviali: corrispondono a mescolanze sabbioso-siltose scarsamente addensate, con colore variabile tra il bruno (7,5yr 4/4) e il grigio (5y 4/4); la loro natura eterogenea è legata al fatto che rielaborano indifferentemente il substrato e i diversi termini della copertura quaternaria. sui versanti circostanti il lembo di villa gualino si osserva infine il diffuso subaffioramento del substrato marino terziario (complesso di baldissero miocene medio), costituito essenzialmente da alternanze sabbiose e ghiaiose di colore grigio-oliva (5y 4/4): al di sopra si sviluppa una copertura discontinua, con spessore esiguo, essenzialmente di natura eolica. in particolare alcuni affioramenti del substrato mettono in luce sabbie debol177lembi di depositi fluviali ... mente cementate che mostrano un’evidente stratificazione decimetrica ed appaiono inclinate di circa 20° verso 250°: sono interessate da due sistemi di fratture, con immersione rispettivamente di 45° verso 85° e di 55° verso 340°, entrambi sottolineati da riempimenti carbonatici con spessore di circa 0,5 cm; localmente si hanno ridotti affioramenti di ghiaie minute. 33.. llaa ssuucccceessssiioonnee ssttrraattiiggrraaffiiccaa ddeell ssoottttoossuuoolloo ddii vviillllaa gguuaalliinnoo aa)) iinntteerrpprreettaazziioonnee ssttrraattiiggrraaffiiccaa ddeeii ssoonnddaaggggii i sondaggi sono ubicati prevalentemente nel settore aa nel tratto di raccordo tra le aree su cui sorgono gli edif ici della fondazione gnocchi e della residenza di villa gualino (sondaggi s1, s2, s3 e s4) e subordinatamente nel settore bb su cui si sviluppa il fig. 2 carta topografica di dettaglio della superficie di villa gualino con l’ubicazione delle prove penetrometriche statiche (triangoli) e dei sondaggi (cerchietti): i sondaggi s1, s2, s3, s4, e3 e f2, utilizzati per la ricostruzione stratigrafica, sono contraddistinti da cerchietti pieni. detailed topographic map of the villa gualino area: triangles and circles indicate the sites of penetrometric tests cpt and boreholes, respectively; the studied boreholes s1, s2, s3, s4, e3 e f2 are marked by full circles. 178 m.g. forno et alii piazzale antistante la residenza di villa gualino (sondaggio f2) e nel versante sottostante (sondaggio e3) (fig. 2). in tutti i sondaggi, nella parte più superficiale, è stata osservata una copertura costituita da terreno di riporto, con spessore variabile tra 2 e 6 m. le osservazioni stratigrafiche delle carote dei sondaggi ubicati nel settore aa (s1, s2, s3 e s4 in figg. 2 e 5) suggeriscono che tra il substrato e il loess eolico si sviluppi una sequenza relativamente potente, i cui caratteri suggeriscono, come si vedrà in seguito, l’origine fluviale. in particolare, nella parte inferiore delle carote, si riconoscono alternanze di sabbie e ghiaie minute, caratterizzate da evidente stratificazione piano-parallela, da colore verde-grigio e dall’abbondanza di microfossili marini, confrontabili con il substrato affiorante (11 in figg. 4b e 4c). al di sopra, separata dal termine sottostante tramite un limite netto, erosionale, si osserva una sequenza costituita da sabbie fini di colore bruno-giallastro (10 yr 5,4/4) e da silt argillosi di colore bruno (7,5 yr 4/4), entrambi privi di evidenti strutture sedimentarie e di resti fossili (rispettivamente 22aa e 22bb in figg. 4b e 4c). questi sedimenti, con spessore variabile tra 2 e 5 m, non risultano confrontabili con nessuno dei termini superficiali: pur nell’impossibilità di effettuare osservazioni di superficie per l’assenza di affioramenti, le caratteristiche sedimentologiche individuabili nelle carote sono compatibili con il riempimento di un canale fluviale, interessato successivamente da fenomeni di esondazione. i principali elementi a favore dell’origine fluviale di questi sedimenti (22 in figg. 4b e 4c) sono rappresentati dalla natura erosionale della superficie di appoggio e dalla giacitura discordante rispetto al substrato marino, come osservabile nelle carote, e dalla geometria complessivamente lenticolare del corpo sedimentario, quale risulta dalla correlazione dei profili. tale geometria è caratterizzata da una base concava modellata nel substrato, legata verosimilmente allo sviluppo del canale, e da un tetto suborizzontale corrispondente all’espressione morfologica dell’originaria pianura alluvionale, successivamente terrazzata dal corso d’acqua e sepolta dal loess eolico. un altro elemento significativo è rappresentato dall’osservazione che questo corpo mostra di chiudersi lateralmente sia in corrispondenza al tratto di versante al di sotto del settore aa, sia in corrispondenza al settore bb. il termine più superficiale è rappresentato infine da silt estremamente selezionati dal punto di vista tessiturale, caratterizzati da colore bruno-giallastro (10 yr 4/6) e dalla diffusione delle concrezioni carbonatiche, privi di stratificazione e ricchi di gasteropodi continentali, assimilabili al loess eolico affiorante (44 in figg. 4b e 4c). le osservazioni delle carote relative ai sondaggi ubicati rispettivamente nel settore bb (f2 in figg. 2 e 5) e lungo il versante sottostante (e3 in figg. 2 e 5) evidenziano una successione diversa da quella precedente. nel primo caso, interposti tra i termini 11 e 44 sono presenti mescolanze sabbioso-siltose, eterogenee dal punto di vista tessiturale e come colorazione: le loro caratteristiche sono confrontabili con quelle dei prodotti colluviali affioranti (33 in figg. 4b e 4c). nel secondo caso si osserva invece la sovrapposizione diretta del loess eolico sul substrato marino (11 e 44 in fig. 5). e’ da sottolineare che in corrispondenza a entrambi questi sondaggi non sono presenti i termini fluviali 22aa e 22bb, che quindi risultano presenti esclusivamente nel settore aa, interpretabile come il lembo pianeggiante originario (cf. §2.). fig. 3 caratteri geotecnici dei sedimenti in corrispondenza al settore bb, come risulta dalle prove penetrometriche. g e o t e c h n i c characteristics of sediments in the sector bb, resulting from the penetrometric tests. resistenza laterale resistenza unitaria di attrito laterale locale fs (mpa) resistenza alla punta resistenza alla punta qc (mpa) p ro fo nd ità ( m ) prova per2 prova per2 p ro fo nd ità ( m ) 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 0 5 10 15 20 25 30 35 40 45 50 55 60 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 fig. 4a carta topografica della superficie di villa gualino, con l’indicazione delle tracce dei profili rappresentati in figure 4b e 4b. il settore aa, indicato con il rigato ravvicinato, corrisponde all ’areale di distribuzione dei sedimenti fluviali; il settore bb, indicato con il ri-gato distanziato, corrisponde all’areale di distribuzione dei terreni di riporto. fig. 4b e fig. 4c rappresentazione in profi lo delle stratigrafie dei sondaggi e profili geologici interpretativi: le profondità indicate si riferiscono al piano campagna. i simboli utilizzati sono i seguenti: 1) alternanze di sedimenti ghiaiosi e sabbiosi marini, ricchi di microfossili (complesso di baldissero miocene medio); 2) successione di deposit i f luviali sabbiosi (a) e siltosi (b), caratterizzati da un suolo con spessore di alterazione superiore a 4 m, patine di argilla discontinue e colore bruno (7.5 yr 5/6) (pleistocene medio); 3) depositi colluviali eterogenei, con grado di pedogenesi variabile (pleistocene superiore); 4) loess eolico ricco di gasteropodi continentali, caratterizzato da un suolo con spessore di alterazione di circa 2 m e colore brunogiallastro (10 y r 4/6) (pleistocene superiore); 5) terreno di riporto. detailed topographic map of the villa gualino area with location of sectors aa and bb and cross sections. cross sections with stratigraphic records of boreholes: depth is referred to the surface. 1) alternating sandy and gravelly marine sediments rich in microfossils (complesso di baldissero middle miocene); 2) sandy (a) and silty (b) fluvial sequence capped by a brown soil (7.5 yr 5/6), at least 4m thick, with discontinuous clay patinas (middle pleistocene); 3) heterogenous and variously wheathered colluvial deposits (upper pleistocene); 4) aeolian loess rich in continental molluscs, capped by a yellowish brown soil (10 yr 4/6), at least 2 m thick (upper pleistocene); 5) dump. 179lembi di depositi fluviali ... 180 i dati analitici di carattere geotecnico, tessiturale, mineralogico e pedolologico di seguito riportati confermano le ipotesi circa la presenza di una successione alluvionale in corrispondenza al settore aa e consentono di stabilire quindi che, almeno localmente, ai lembi terrazzati descritti sono associati depositi fluviali. bb)) ppaarraammeettrrii ggeeootteeccnniiccii nell’area di villa gualino la stesura del progetto di ristrutturazione degli edifici esistenti e di edificazione di nuovi fabbricati ha comportato l’esecuzione di una serie di indagini geognostiche (fig. 2), così come previsto dal quadro normativo del dm. ll.pp. 11/3/1988. i parametri geotecnici indice misurati in occasione della realizzazione delle prove penetrometriche hanno evidenziato la presenza di una copertura di sedimenti sciolti, relativamente potente, con caratteristiche geotecniche scadenti (fig. 3). in particolare, sulla base delle correlazioni empiriche tra prove geognostiche e parametrizzazione del terreno più note e di uso generalizzato impiegate nel campo della meccanica dei terreni, sono stati misurati per questi sedimenti i valori di resistenza penetrometrica dinamica scpt n= 3-4, di resistenza penetrometrica statica cpt alla punta rp=35-35 mpa e di attrito laterale fs=0,1 mpa, di resistenza al taglio non drenata cu da vane test = 0,5 kg/cmq e di resistenza unitaria non drenata al poket 2cu= 1,12 kg/cmq. le caratteristiche della copertura hanno portato ad ampliare il quadro conoscitivo mediante un approfondimento di indagine: sono stati quindi eseguiti numerosi sondaggi a carotaggio continuo (s1, s2, s3, s4, f2 ed e3 e altri privi di sigla in fig. 2) e raccolti una ventina di campioni rappresentativi delle diverse profondità di indagine (fig. 5), al fine di caratterizzare i parametri geotecnici. i dati più significativi si riferiscono a prove di taglio diretto con valutazione dell’angolo di resistenza al taglio residua compreso tra 27,5° e 31,4° e a prove di valutazione dei limiti di consistenza con limite liquido ll compreso tra 28,5% e 33,8%, limite plastico lp tra 24,3% 23% e indice di plasticità ip tra 4,2% e 10,8%. l’insieme dei dati geognostici e di laboratorio ha permesso di evidenziare lo spessore significativo dei sedimenti incoerenti, variabile tra 10 e 15 m e quindi anomalo per l’area collinare, in base al quale è stato predisposto il progetto esecutivo dei nuovi edifici. cc)) ccaarraatttteerrii tteessssiittuurraallii sono stati presi in esame dal punto di vista tessiturale due gruppi rispettivamente di 3 e 4 campioni provenienti dai sondaggi f2 ed e3 ad una profondità compresa tra 15 e 12 m, riferibili al substrato, tre gruppi di 3 campioni provenienti rispettivamente dai sondaggi s1, s2 e s3 e un gruppo di 4 campioni provenienti dal sondaggio s4 ad una profondità compresa tra 12 e 8 m, riferibili ai sedimenti fluviali (considerati in modo indifferenziato a causa della scarsità del materiale a disposizione), e infine due gruppi rispettivamente di 7 e 9 campioni provenienti dai sondaggi f2 ed e3 ad una profondità compresa tra 8 e 4 m, riferibili al loess eolico (fig. 5). le analisi granulometriche per la determinazione delle percentuali in peso di ciascuna classe di particelle costituenti i sedimenti in esame sono state effettuate con la procedura per via umida e per la frazione fine, avente diametro inferiore a 0.074 mm , con l’ analisi per sedimentazione mediante densimetro a.s.t.m. 152h, secondo le norme a.s.t.m. e le raccomandazioni a.g.i. sulle prove geotecniche di laboratorio del 1994. l’osservazione dei sedimenti individuati alla base dei sondaggi f2 ed e3 e le relative analisi granulometriche mettono in evidenza la presenza di nette alternanze di ghiaie sabbiose, debolmente limose, e di sabbie limose con ghiaia, riferibili al substrato marino: la curva granulometrica di sintesi conferma la tessitura grossolana di questi sedimenti (11 in fig. 6). l’esame dei termini incontrati nella parte intermedia dei sondaggi s1, s2, s3 e s4, sviluppati al di sopra del substrato marino, e le relative analisi granulometriche evidenziano la presenza di una successione fluviale costituita alla base da limi molto sabbiosi e nella parte alta da limi molto argillosi. la curva granulometrica di sintesi conferma l’esistenza di sedimenti caratterizzati da tessitura nettamente più fine, rispetto al substrato, e da una modesta selezione, come suggerito dallo sviluppo di “code” sia ghiaiose che argillose, in accordo con la genesi fluviale ipotizzata per questi sedimenti (22 in fig. 6). infine l’osservazione dei sedimenti più superficiali incontrati nelle stesse stratigrafie e le relative analisi granulometriche evidenziano lo sviluppo di una copertura costituita da sedimenti siltosi estremamente selezionati, assimilabili al loess eolico: la curva granulometrica di sinm.g. forno et alii f2e3 s1 1 42 s2 s3 320 325 330 335 340 345 350 s4 5 analisi mineralogiche analisi tessiturali analisi geotecniche analisi pedologiche 3 fig. 5 localizzazione dei campioni presi in esame: 1) substrato marino; 2) depositi fluviali; 3) depositi colluviali; 4) loess eolico; 5) terreno di riporto. location of studied samples: 1) marine sediments; 2) fluvial sediments; 3)colluvial sediments; 4) aeolian loess; 5) dump. tesi, realizzata previa eliminazione dei granuli cementati e caratterizzata da un andamento subverticale e dall’esclusiva presenza di limo e sabbia, conferma la presenza di sedimenti con elevata selezione, in accordo con lo sviluppo di una copertura di loess (33 in fig. 6). dd)) ccoommppoossiizziioonnee mmiinneerraallooggiiccaa le analisi sono state effettuate mediante l’osservazione al microscopio binoculare del trattenuto al setaccio 200 mesh, con apertura delle maglie di 0,074 mm: i granuli, corrispondenti alla classe granulometrica della sabbia molto fine secondo la classificazione di wentworth, dopo essere stati trattati in mortaio con acetone per eliminare eventuali patine di incrostanti, sono stati posti su vetrini, fissati seppure blandamente con eugenolo, quindi coperti con vetrino copri oggetto. sono stati osservati complessivamente 26 campioni; i caratteri tessiturali e pedologici suggerivano di riferirne 6 al substrato marino, 16 ai depositi fluviali e 4 al sovrastante loess eolico. in particolare (fig. 5), i campioni relativi al substrato e al loess provengono dai sondaggi f2 ed e3, ubicati rispettivamente in corrispondenza al settore bb (sondaggio f2) e al versante sottostante (sondaggio e3); i depositi fluviali sono stati, invece, osservati nei campioni provenienti dai sondaggi s1, s2, s3 e s4 ubicati in corrispondenza al settore aa. i dati raccolti, schematizzati in tabella 1, possono così essere riassunti. il substrato marino (11 in fig. 4) è costituito, in percentuali circa confrontabili, da quarzo, mica bianca, serpentino, glaucofane, anfibolo verde scuro (hastingsite?), tremolite, epidoti e granato, con ridotte quantità di minerali accessori. i depositi fluviali (22aa e 22bb in fig. 4) sono formati in netta prevalenza da quarzo, mica bianca e clorite e da minori quantità di biotite, glaucofane, tremolite, anfibolo verde scuro (hastingsite?) e minerali opachi, con trascurabili quantità di minerali accessori. in particolare i diversi campioni di depositi fluviali, riferibili sia alla facies sabbiosa (termine 22aa) sia a quella siltosa (termine 22bb), mostrano caratteristiche mineralogiche del tutto confrontabili tra loro: l’unica differenza significativa è rappresentata dalla diffusa presenza di incrostazioni di ossidi idrati sui granuli dei campioni riferibili al termine 22bb. il loess eolico (33 in fig. 4) risulta costituito essenzialmente da quarzo, mica bianca e carbonati, con quantità nettamente subordinate di clorite, glaucofane, tremolite, biotite, epidoti e minerali opachi. i tre termini costituenti la successione stratigrafica risultano, quindi, ben differenziabili tra loro anche dal punto di vista mineralogico. ee)) ccaarraatttteerrii ppeeddooggeenneettiiccii al fine di valutare il grado di alterazione dei depositi fluviali presi in esame è stato condotto uno studio impiegando i metodi di analisi chimica del suolo (ministero delle politiche agricole e forestali, 2000): i parametri presi in considerazione sono la tessitura, il contenuto carbonatico e la quantità e natura degli ossidi di fe, che rappresentano i principali indici di maturità del suolo (arduino et al., 1984; jackson, 1965). i campioni erano costituti prevalentemente da particelle <2mm e sono stati previamente essiccati a 40 °c prima di essere analizzati. in particolare la valutazione della tessitura è stata effettuata mediante sedimentazione di sospensioni acquose disperse con na esametafosfato (metodo della pipetta); il tenore in carbonato totale è stato determinato dosando volumetricamente la co2. il contenuto totale di fe, al, ni (fet, alt, nitt) è stato dosato mediante spettrofotometria in assorbimento atomico (saa) negli estratti ottenuti previo attacco con miscela regia dei campioni macinati con mortaio (<0.5mm); la caratterizzazione degli ossidi di fe è stata condotta mediante alcune estrazioni chimiche selettive. in particolare l’estrazione degli ossidi di fe solubili in ossalato è stata eseguita secondo s c h w e r t m a n n (1964) e il contenuto di fe in soluzione (feo) è stato misurato via saa. feo, per la selettività dell’estraente, può essere considerato derivato principalmente da ossidi e ossidrossidi di fe amorfi o a basso ordine cristallino. la quantità totale di ossidi di ferro di origine pedogenetica è stata stimata mediante la dissoluzione con ditionito citrato bicarbonato (boero & s c h w e r t m a n n , 1987); il fe e l’al in soluzione (fed e ald) sono stati dosati via saa. l’ald si assume derivi dalla sostituzione isomorfa del fe nel reticolo 181lembi di depositi fluviali ... fig. 6 curve granulometriche cumulative relative ai sedimenti marini del substrato (1), ai depositi fluviali (2) e al loess eolico (3). cumulative texture curves of marine sediments (1), fluvial sediments (2) and aeolian loess (3). cristallino degli ossidi di fe. sono state condotte anche estrazioni di controllo con solo citrato bicarbonato (fecb e alcb) per tener conto del rilascio eventuale della matrice. nei rapporti di fed con fet e nei calcoli con ald è stata detratta la quantità corrispondente a fecb e alcb rispettivamente. poiché fed deriva dagli ossidi di fe pedogenetici in toto, la differenza fed-feo è verosimilmente ascrivibile alla goethite avendo i sedimenti una colorazione giallastra (variabile tra 10yr 4,5/4 e 7,5yr 4/4); il rapporto (fed/fet è considerato un indice strettamente correlato con l’intensità dei processi pedogenetici con valori prossimi all’unità per suoli molto alterati e prossimi allo zero in assenza di ossidi di ferro pedogenetici (cornell & schwertmann, 1996). la quantità di goethite è stata quindi calcolata assumendo questo minerale come unica fase cristallina ed attribuendole la differenza fed-feo. complessivamente sono stati studiati undici campioni provenienti dai sondaggi s1 e s4 (fig. 5): i risutalti ottenuti sono compendiati in tab. 2. prendendo in esame il sondaggio s4 si osserva che il loess eolico (campione 1) è caratterizzato da un contenuto in carbonati totali del 9% che contrasta con quello dei depositi fluviali sottostanti (campioni 2, 3 e 4), con un contenuto di carbonati del 1-2%. solo alla base della successione fluviale (campione 5) si ha un contenuto di carbonati del 7%: tale elevata quantità potrebbe essere attribuita alla precipitazione del carbonato di ca di origine secondaria alimentata dalla dissoluzione di quello contenuto nel loess sovrastante. un’altra ipotesi è che i depositi fluviali sabbiosi basali contengano carbonato in quanto al momento della sepoltura ad opera dei depositi fluviali sovrastanti, i processi pedogenetici erano appena iniziati, come testimonierebbe anche il modesto grado di alterazione stimato dal rapporto fed/ fet di 0.36. 182 m.g. forno et alii tab. 1 composizione mineralogica media dei campioni presi in esame. i simboli utilizzati sono i seguenti: xxxx = minerali prevalenti; xxx = molto abbondanti; xx = abbondanti; x = poco abbondanti; = scarsi; -= molto scarsi; / = assenti. mineralogical composition of the studied samples. symbols for lithotype abundance are: xxxx = prevailing; xxx = very abundant; xx = abundant; x = poorly abundant; = scanty; -= very scanty; / = absent. mmiinneerraallii ssuubbssttrraattoo ddeeppoossiittii llooeessss mmaarriinnoo fflluuvviiaallii eeoolliiccoo quarzo xxx xxxx xxxx k-feldspato x / albite x / plagioclasio x / / mica bianca xxx xxxx xxxx sericite in aggregati x x clorite x xxxx x biotite x xx x serpentino xxx x epidoto xx xx glaucofane xxx xx x anf. verde scuro (hastingsite) xx xx / tremolite xx xx x cloritoide x / pirosseno onfacitico x x / carbonato in aggregati x x xxxx rutilo sagenitico (inclusioni) x x / granato xx / tormalina x minerali opachi (alterati) x xx x ss oonn ddaa gggg iioo cc aamm ppii oonn ii nn aatt uurr aa ddee ll dd eepp ooss iittoo pp rroo ffoo nndd iittàà ss aabb bbii aa gg ss aabb bbii aa ff llii mm oo gg llii mm oo ff aa rrgg iillll aa cc aacc oo 33 ttoo tt ff ee dd ff ee tt ff ee oo ff eedd //ff eett gg tt aa ll ss ooss tt (m ) (% ) (% ) (% ) (% ) (% ) (% ) (% ) (% ) (% ) (% ) (% ) (m ol % ) 1 lo es s 8, 30 -8 ,3 5 0, 6 30 ,9 28 ,5 21 ,3 18 ,7 9 1, 75 3, 77 5 0, 18 0, 45 7 2, 49 5 10 ,5 6 2 de p. fl uv . s ilt os i 8, 70 -8 ,8 0 0, 8 31 ,2 22 ,8 24 ,1 21 ,2 2 2, 07 3, 95 0, 24 0, 51 6 2, 89 7 12 ,8 8 s 4 3 de p. fl uv . s ilt os i 9, 50 -9 ,6 0 2, 2 36 ,2 14 ,8 18 ,3 28 ,5 1 3, 19 5, 02 5 0, 22 0, 63 0 4, 73 1 21 ,6 6 4 de p. fl uv . s ab bi os i 10 ,5 010 ,6 0 0, 1 47 ,3 24 ,5 16 ,3 11 ,9 2 2, 19 4, 22 5 0, 21 0, 51 4 3, 14 5 16 ,6 6 5 de p. fl uv . s ab bi os i 11 ,7 011 ,8 0 10 ,1 37 ,4 15 ,1 19 ,1 18 ,3 7 1, 64 4, 47 5 0, 10 0, 36 2 2, 44 9 9, 76 6 su bs tr at o 14 ,7 014 ,8 0 51 ,5 16 ,2 5, 8 14 ,0 12 ,5 0, 4 0, 65 4, 52 5 0, 14 0, 13 8 0, 80 8 4, 12 7 lo es s 9, 80 -1 0, 00 0, 6 71 ,3 2, 3 9, 3 16 ,5 11 1, 58 3, 62 5 0, 16 0, 43 1 2, 25 1 10 ,0 8 8 de p. fl uv . s ilt os i 10 ,6 010 ,7 0 2, 6 54 ,0 6, 1 12 ,8 24 ,4 1 2, 31 3, 75 0, 26 0, 61 1 3, 26 5 16 ,2 4 s 1 9 de p. fl uv . s ilt os i 11 ,6 011 ,7 0 1, 6 58 ,6 8, 0 10 ,4 21 ,4 0 2, 84 4, 95 0, 25 0, 57 0 4, 11 9 20 ,9 6 10 de p. fl uv . s ab bi os i 13 ,6 013 ,7 0 8, 0 41 ,4 27 ,4 14 ,2 9, 0 19 1, 35 2, 9 0, 14 0, 46 0 1, 92 8 9, 57 11 de p. fl uv . s ab bi os i 14 ,2 014 ,3 0 5, 3 50 ,0 22 ,3 14 ,8 7, 7 21 1, 19 2, 95 0, 19 0, 39 6 1, 74 3 8, 72 12 su bs tr at o 16 ,6 016 ,7 0 55 ,7 23 ,4 4, 5 9, 8 6, 7 8 0, 28 4, 7 0, 11 0, 05 5 0, 26 9 3, 33 t ab . 2 p rin ci pa li ca ra tte ris tic he fi si ch e e ch im ic he d ei s ed im en ti. ( g = g ro ss a, f = fi ne , c ac o 3 to t= c ar bo na ti to ta li, g t= g oe th ite , a l s os t= s os tit uz io ni is om or fe n el la g oe th ite , a ltr e ab br ev ia zi oni c fr . t es to ). m ai n ph ys ic al a nd c he m ic al c ha ra ct er is tic s of t he s ed im en ts . (g = co ar se , f = fin e, c ac o 3 to t= t ot al c ar bo na te s, g t= g oe th ite , a l s os t = is om or ph ou s s ub st itu tio n o f a l f or f e in t he g oe th ite , ot he r ab br ev ia tio ns s ee te xt ). il loess eolico (campione 1) si caratterizza anche per un contenuto di fet inferiore rispetto ai depositi fluviali (campioni 2, 3, 4 e 5) (3.8 versus 4.4%): questi ultimi appaiono decisamente più alterati (mediamente fed/ fet 0.58) rispetto al loess (fed/ fet 0.46) e la goethite risulta essere l’unico ossido di ferro cristallino presente. si osserva inoltre come complessivamente i depositi fluviali siltosi (campioni 2 e 3) risultino più alterati (media fed/ fet 0.58) di quelli sabbiosi sottostanti (campioni 4 e 5) (media fed/ fet 0.42): nei primi infatti anche la goethite è caratterizzata da un elevato grado di al sostituzione (16 mol % versus 13). i depositi fluviali si differenziano anche rispetto al substrato marino (campione 6) per un maggior contenuto di carbonato (media 3% versus 0.4) e per un grado di alterazione nettamente maggiore (media fed/ fet 0.50 versus 0.14). nel sondaggio s1 si evidenzia come la copertura loessica (campione 7) sia caratterizzata dall’11% di carbonato e contrasti con i depositi fluviali siltosi sottostanti (campioni 8 e 9) pressoché decarbonatati. i depositi fluviali inferiori (campioni 10 e 11) contengono invece mediamente il 20% di carbonati, in analogia ai sedimenti marini basali, anch’essi carbonatici (8%): la maggiore vicinanza di questi depositi al substrato marino complica le ipotesi genetiche del carbonato rispetto al sondaggio s4, pur non perdendo la netta differenziazione in termini di alterazione. i depositi fluviali siltosi (campioni 8 e 9), caratterizzati da un rapporto fed/ fet pari a 0.59, risultano caratterizzati da un grado di alterazione maggiore sia rispetto ai depositi fluviali sabbiosi sottostanti (campioni 10 e 11), sia rispetto alla copertura loessica (campione 7), entrambi caratterizzati da un rapporto fed/ fet pari a 0.43. il maggior grado di alterazione di questi sedimenti si traduce in una maggior quantità di goethite (3.70 %) avente in media 18 moli % di al sostituzione, rispetto ai depositi fluviali sabbiosi sottostanti aventi un minore tenore di goethite (2%) con 10 moli % di al sostituzioni. sulla base dello stesso indice di alterazione il substrato marino (campione 12) sottostante la successione fluviale risulta sostanzialmente inalterato. l’insieme delle osservazioni riportate consente di ipotizzare come nei sondaggi presi in esame si sviluppi una successione stratigrafica caratterizzata, anche dal punto di vista pedologico, da tre diversi termini sovrapposti. tale successione risulta costituita alla base da sedimenti privi di evidenti segni di alterazione, corrispondenti al substrato marino, nella parte intermedia da sedimenti caratterizzati da una notevole concentrazione di ossidi di fe di origine pedogenetica, corrispondenti ai sedimenti fluviali, e nella parte superiore da sedimenti sensibilmente carbonatici, corrispondenti al loess eolico. come indicato nella letteratura (jackson, 1965) la presenza di ossidi di fe pedogenetici è infatti tipica dei suoli che hanno subito intensi processi di alterazione; la presenza dei carbonati è invece indice di uno stadio iniziale nei processi di pedogenetici. la netta disomogeneità del grado di alterazione tra i depositi fluviali e il substrato marino suggerisce che quest’ultimo sia stato decapitato della parte pedogenizzata ed è coerente con la presenza di una superficie di erosione alla base dei depositi fluviali. l’alterazione dei depositi fluviali, pur inibiti nel loro sviluppo dal contatto con il loess eolico, documenta la presenza di intensi processi pedogenetici soprattutto nella sua porzione più superficiale. per quanto riguarda il significato cronologico dei suoli descritti i processi di alterazione cui sono stati sottoposti i depositi fluviali di entrambi i sondaggi sarebbero collocati nella parte superiore del pleistocene medio secondo la relazione di arduino et al. (1984) che, prendendo in considerazione la successione pedostratigrafica di alcuni terrazzi dell’alta pianura piemontese opportunamente calibrata con elementi stratigrafici di altra natura, lega il grado di alterazione del suolo attraverso lo studio degli ossidi di fe con l’età del deposito fluviale sottostante. e’ da sottolineare che le considerazioni prima riportate si riferiscono a successioni fluviali affioranti, tuttora interessate da fenomeni di alterazione: trattandosi invece, nel caso in esame, di sedimenti sepolti i dati misurati si riferiscono all’intervallo di tempo anteriore alla copertura da parte del sovrastante loess eolico. 55.. ccoonnssiiddeerraazziioonnii ccoonncclluussiivvee la campagna geognostica, effettuata nell’ambito del progetto di ristrutturazione e nuova edificazione dell’area di villa gualino (figg. 1 e 2), ha offerto l’opportunità di studiarne in dettaglio l’immediato sottosuolo. l’insieme dei dati, suggeriti in un primo momento dai risultati delle prove penetrometriche (fig. 3) e successivamente controllati in modo più circostanziato tramite l’esame delle stratigrafie dei sondaggi, individua la presenza di uno spessore rilevante di depositi incoerenti: tale spessore, compreso a seconda dei punti tra 10 e 15 m, risulta anomalo per l’area collinare dove in genere si sviluppa un’esigua copertura di natura colluviale e/o eolica direttamente sulle formazioni marine del substrato. i risultati dell’indagine effettuata suggeriscono invece che in corrispondenza al settore aa dell’area in esame, tra il substrato (11 in figg. 4b e 4c) e questa copertura (33 e 44), si abbia l’interposizione di sedimenti fluviali (22). a suggerire questa interpretazione valgono essenzialmente la natura erosionale della superficie di appoggio, osservata nelle diverse stratigrafie prese in esame e sottolineata dai dati pedologici, la giacitura discordante rispetto al substrato marino e la geometria complessivamente lenticolare del corpo sedimentario, evidenziata tramite la correlazione dei profili (fig. 5): la base concava, corrispondente a una depressione modellata nel substrato, sembrerebbe testimoniare la presenza di un canale fluviale, mentre la superficie sommitale suborizzontale corrisponderebbe ad un lembo di pianura alluvionale, successivamente terrazzata dal corso d’acqua e sepolta dai sedimenti eolici; anche le osservazioni sedimentologiche, e in particolare il confronto tra la netta stratificazione piano-parallela del substrato e la mancanza di una evidente stratificazione dei termini alluvionali, sono in accordo con lo sviluppo di un canale fluviale interessato da fenomeni di esondazione. il modellamento fluviale del settore aa è anche suggerito dalla distribuzione della successione alluvionale, limitata appunto a un lembo subpianeggiante, e dall’analogia di facies rispetto ad altri depositi riferibili alla successione fluviale terrazzata individuata sul versante occidentale della collina di torino. inoltre il lembo di villa gualino si raccorda altimetricamente con altri lembi conservati sulle diverse dorsali dello stesso ver183lembi di depositi fluviali ... sante che rappresentano i relitti di una originaria superficie terrazzata, caratterizzata da una debole inclinazione verso nord (boano & forno, 1997). la differenziazione della successione fluviale è legata ai diversi caratteri rispetto alle formazioni marine e ai sedimenti eolici e colluviali, evidenziati tramite lo studio dei campioni raccolti (fig. 5). in particolare, per quanto riguarda l’aspetto tessiturale, i sedimenti alluvionali presentano natura essenzialmente sabbiosa nella parte inferiore e siltoso-argillosa in quella superiore e sono caratterizzati da scarsa selezione (22 in fig. 6): differiscono, quindi, sia dalle sottostanti formazioni marine, costituite prevalentemente da alternanze sabbiose e ghiaiose (11 in fig. 6), sia dalla sovrastante copertura eolica, con tessitura siltosa omogenea (33 in fig. 6). dal punto di vista mineralogico i sedimenti fluviali sono formati essenzialmente da quarzo, mica bianca e clorite, con minori quantità di biotite, epidoto, glaucofane, hastingsite, tremolite e minerali opachi: i diversi campioni mostrano tra loro una costituzione omogenea ed invece differiscono dai sedimenti marini, che sebbene caratterizzati dagli stessi costituenti principali (quarzo e mica bianca) mostrano anche notevoli quantità di serpentino, glaucofane, hastingsite, tremolite e granato (tab. 1). marcate sono anche le differenze di tali sedimenti rispetto alla copertura eolica, che risulta caratterizzata da una minore varietà mineralogica e da un elevato contenuto carbonatico. ulteriori differenze tra i diversi termini riguardano la diffusione nel substrato marino e nel loess eolico di gusci carbonatici, corrispondenti rispettivamente a microfossili marini e a frammenti di molluschi continentali, assenti invece nei sedimenti alluvionali. i dati pedologici indicano inoltre la maggiore alterazione dei sedimenti fluviali sia rispetto ai termini marini, privi di evidenti segni di alterazione, sia nei confronti del loess eolico, caratterizzato essenzialmente da fenomeni di lisciviazione dei carbonati (tab. 2): confermano quindi la deposizione della successione fluviale al di sopra di una superficie erosionale, responsabile della troncatura dei suoli sviluppati sul substrato. gli stessi dati, in assenza di informazioni stratigrafiche dirette, suggeriscono l’attribuzione dei suoli sviluppati su quest’ultima alla parte superiore del pleistocene medio, in analogia ad altri suoli rinvenuti nel settore piemontese (arduino et al., 1984); confermerebbero inoltre l’attribuzione del loess eolico al tardo pleistocene superiore già ipotizzata in precedenza (forno, 1979). i risultati dell’indagine suggeriscono invece che il settore bb, caratterizzato solo dalla presenza di sedimenti colluviali, corrisponda ad una superficie almeno in parte antropica: in particolare tale settore sarebbe stato interessato da lavori sia di accumulo, in corrispondenza alla superficie su cui sorge la residenza di villa gualino, sia di spianamento, in corrispondenza all’esteso piazzale antistante. la composizione mineralogica dei sedimenti fluviali fornisce alcune utili indicazioni sul bacino di provenienza del corso d’acqua. in particolare, la mineralogia sembrerebbe escludere l’apporto dei collettori del bacino piemontese meridionale, in quanto sono assenti o molto scarsi i granuli di plagioclasio provenienti dal massiccio migmatitico dell’argentera e i granuli di lave acide riferibili alle coperture vulcaniche e vulcanoclastiche permiane. questa ipotesi è confortata dalle conoscenze riguardanti sia l’andamento, nello stesso intervallo di tempo, del reticolato idrografico del bacino piemontese meridionale, caratterizzato come si è detto da un collettore impostato in corrispondenza al versante meridionale della collina di torino (aa in fig. 1), sia la natura dei clasti dei deposit i ad esso associati (compagnoni & forno, 1992; carraro et al., 1995). la composizione mineralogica è invece compatibile con un’alimentazione dai corsi d’acqua del bacino piemontese settentrionale provenienti dal settore alpino, caratterizzati dall’abbondanza dei clasti della zona sesia-lanzo e del complesso dei calcescisti con pietre verdi (bb in fig. 1): tale provenienza è suggerita dall’abbondanza dei minerali caratteristici sia delle metaofioliti in facies eclogitica della zona piemontese interna (glaucofane, hastingsite, epidoto, onfacite) sia dei metasedimenti o calcescisti (quarzo e miche chiare). la scarsità di granato, che rappresenta in associazione con l’onfacite il minerale più tipico delle eclogiti, potrebbe essere legata alla densità di questo minerale che ne avrebbe favorito la concentrazione nelle frazioni più grossolane, non rappresentate nei sedimenti fluviali in esame. l’insieme degli elementi mineralogici suggerisce essenzialmente il contributo del f. dora riparia, in cui queste rocce sono particolarmente diffuse, piuttosto che delle valli di lanzo, dove si ha anche una notevole distribuzione delle peridotiti più o meno serpentinizzate del massiccio ultrabasico di lanzo, totalmente assenti nei sedimenti in esame. rriinnggrraazziiaammeennttii gli autori ringraziano f. carraro e g. b. castiglioni per la revisione critica del manoscritto. lavoro realizzato con il contributo finanziario dei servizi tecnici di prevenzione della regione piemonte. llaavvoorrii cciittaattii arduino e., barberis e., carraro f. & forno m. g. (1984) estimating relative ages from ironoxide/total-iron ratios of soils in the western po valley, italy. geoderma, 3333, 39-52, amsterdam. boano p. & forno m. g. (1997) evoluzione morfologica quaternaria del versante occidentale della collina di torino. geoitalia, 1° forum fist, 1997, 22, 221-222. boano p., carraro f., forno m. g., giardino m., lozar f., lucchesi s., perotto a., piana f. & polino r. (2000) l’evoluzione recente della collina di torino: un esempio di interazione tra attività geodinamica e morfogenesi. in: carulli g. b. & longo salvator g. (eds.) riassunti delle comunicazioni orali e dei posters della 80a riun. est. soc. geol. it. (trieste, 6-8 settembre 2000), ed. univ. trieste, 81-83. boero v. & schwertmann u. (1987) iron oxide mineralogy of terra rossa and its genetic implications. geoderma, 4444, 319-327. bonsignore g., bortolami g. c., elter g., montrasio a., petrucci f., ragni u., sacchi r., sturani c. & zanella e. (1969) note illustrative della carta 184 m.g. forno et alii geologica d'ital ia, fogli 56 e 57 "torino e vercelli". iia ed., serv. geol. it., roma, 96 pp. bortolami g. c., crema g. c., sacchi r., sturani c. & zanella e. (1969) foglio 56 "torino" della carta geologica d'italia alla scala 1:100.000. iia ed., serv. geol. it., roma. carraro f. (1976) diversione pleistocenica nel deflusso del bacino piemontese meridionale: un’ipotesi di lavoro. gruppo di studio del quaternario padano, 33, 89-100. carraro f., forno m. g. & valpreda e. (1982) field trip in northern italy. guidebook. september 15th. piedmont: asti area. international geological correlation programme project 73/1/24 “quaternary glaciations in the northern hemisphere”. final session. september 1/17th 1982. franceitaly. litografia massaza & sinchetto, 24 pp. carraro f., collo g., forno m. g., giardino m., maraga f., perotto a. & tropeano d. (1995) l'evoluzione del reticolato idrografico del piemonte centrale in relazione alla mobilità quaternaria. in: polino r. & sacchi r. (eds.) atti del convegno "rapporti alpi-appennino" e guide alle escursioni (peveragno (cn), 31 maggio-1 giugno 1994). accademia nazionale delle scienze, 1144, 445-461. compagnoni r. & forno m. g. (1992) significato geologico di depositi fluviali ghiaiosi pleistocenici medi nella collina di torino. il quaternario, it. journ. quatern. sc., 55, 105-122. cornell r. m. & schwertmann u. (1996) the iron oxides. vch, weinheim, 573 pp. forno m. g. (1979) il “loess" della collina di torino: revisione della sua distribuzione e della sua interpretazione genetica e cronologica. geogr. fis. dinam. quatern., 22, 105-124. forno m. g. (1990) aeolian and reworked loess in the turin hills (northwestern italy). quatern. int., 55, 81-87, oxford. jackson m. l. (1965) clay transformations in soil genesis during the quaternary. soil sc., 9999, 15-22. ministero delle politiche agricole e forestali (2000) metodi di analisi chimica del suolo. franco angeli, milano. schwertmann u. (1964) differenzierung der eisenoxide des boden durch extraktion mit ammoniumoxalat-loesung. z. pflanzenernähr. düngung bodenkunde, 110055, 194-202. 185lembi di depositi fluviali ... ms. ricevuto il 23 aprile 2002 testo definitivo ricevuto il 30 luglio 2002 ms. received: april 23, 2002 final text received: july 30, 2002 imp.munno-petrosino nneeww ccoonnssttrraaiinnttss oonn tthhee ooccccuurrrreennccee ooff yy--33 uuppppeerr pplleeiissttoocceennee tteepphhrraa mmaarrkkeerr llaayyeerr iinn tthhee ttyyrrrrhheenniiaann sseeaa rroossaallbbaa mmuunnnnoo11 && ppaaoollaa ppeettrroossiinnoo11 1dipartimento di scienze della terra dell'università di napoli federico ii l.go s. marcellino 10, 80138 napoli abstract: munno r. & petrosino p., new constraints on the occurrence of y-3 upper pleistocene tephra layer in the tyrrhenian sea. (it issn 0394 – 3356, 2004). a widespread tephra layer, other than the well known y-5, has been identified in the upper pleistocene marine succession in the tyrrhenian sea. two investigated gravity cores showed, in fact, the presence of two companion pyroclastic tephra layers, separated by a varying thickness of pelagic sediments. the pyroclastic layers are mainly made up of pumice fragments and glass shards together with few k-feldspars and clino-pyroxene crystals. both layers are alcali-trachytic in composition, even though a sharp difference emerges in the k/na ratio that characterizes the two glasses. 14c dating of foraminiferous shells embedded in the clay layers directly underlying the most recent tephra gave an age of about 26 ka. an accurate review of literature regarding tephrostratigraphy in the mediterranean area made it possible to correlate the older one to the y-5 marker layer, joined to the campanian ignimbrite eruption, a paroxystic event in the campi flegrei area. the younger layer has been correlated with the y-3 marker layer and probably represents another huge pyroclastic flow event from the campanian area, whose products have not yet been distinguished in the field from those of typical campanian ignimbrite. this work clearly identifies the layer y-3, firstly recorded by keller et al. (1978), as the result of a specific volcanic event different from the campanian ignimbrite (marker layer y-5), defines its mineralogical and chemical composition together with its relative age offering an useful support for paleoclimatic and paleoenvinromental reconstruction of the sedimentation in the tyrrhenian area. riassunto: munno r. & petrosino p., caratterizzazione di y-3, un tefra per il pleistocene superiore nel mar tirreno. (it issn 0394 – 3356, 2004). nella successione marina del pleistocene superiore, nel basso tirreno, è stato identificato e caratterizzato un livello di tefra diverso dall'y-5, che è il livello marker in genere associato con la grossa eruzione dell' ignimbrite campana. molti gravity cores analizzati hanno infatti mostrato la presenza di una doppietta di livelli piroclastici, separati da uno spessore variabile di sedimenti pelagici. i livelli di tefra sono entrambi costituiti da frammenti di pomici e shard vetrose con una minima percentuale di cristalli di k-feldspato e clinopirosseno. entrambi i livelli mostrano un chimismo alcalitrachitico, ma sono caratterizzati da una netta differenza nel rapporto k/na. datazioni 14c ottenute su gusci di foraminiferi prelevati all'interno dell'argilla alla base del tefra più recente hanno fornito un'età di circa 26 ka. una revisione accurata della letteratura riguardante la tefrostratigrafia nell'area mediterranea ha permesso di correlare il più antico con il marker y-5, che rimanda all'eruzione dell'ignimbrite campana, un evento parossistico proveniente dall'area flegrea. il livello più recente è stato correlato con il marker y-3 e, probabilmente, rappresenta un altro evento di rilievo dell'area campana, i cui prodotti, sul campo, non sono stati ancora distinti da quelli dell'ignimbrite campana. il lavoro identifica in maniera definitiva il livello y-3, individuato per la prima volta da keller et al. (1978), come il risultato di un evento specifico diverso dall'ignimbrite campana (marker layer y-5), ne definisce la composizione mineralogica e chimica, l'età relativa e, mappandone la distribuzione, offre un utile supporto per la ricostruzione paleoclimatica e paleoambientale della sedimentazione nell'area mediterranea. keywords: gravity core, tephra layer, tephrocronology, campanian ignimbrite parole chiave: carote, livello di tefra, tefrocronologia, ignimbrite campana il quaternario italian journal of quaternary sciences 1177(1), 2004, 11-20 11.. iinnttrroodduuccttiioonn during the last 40000 years several violent volcanic eruptions took place in the campanian volcanic province, southern italy. in particular, the main volcanic sources in the area for that time-span are campi flegrei and somma-vesuvio. although a good knowledge of their activity is now available, and the products are quite well mapped in areas proximal to the sources, some difficulty however persists in the identification of the origin of tephra layers when they are found interbedded to sedimentary sequences in areas many kilometres far from the volcanoes. this is the particular field of interest of tephrostratigraphy and tephrochronology that, together with a detailed biostratigraphy, make it possible to identify marker horizons useful for geological and geomorphological reconstructions. starting from about 40 ka b.p. the best represented campanian tephra layer in the central mediterranean is y-5, so labelled according to the nomenclature of tephra layers in the eastern mediterranean of keller et al. (1978). although a great deal of testified occurrences of this pyroclastic layer are available, no clear attribution to a source has been made until recent. firstly, keller et al. (1978), in fact, attributed it to the ischia citara-serrara fontana formation, even if this formation, which is the product of several small-volume eruptions, is not widely dispersed in the field (vezzoli, 1988). shortly following this attribution, thunnel et al. (1979) definitely correlated the y-5 tephra layer with the campanian ignimbrite, recorded in the field as a widespread pyroclastic flow deposit (barberi et al., 1978; fisher et al., 1993; rosi et al., 1996) joined to a thick pyroclastic fall layer emplaced 12 r. munno & p. petrosino towards the east from the campi flegrei source area (rosi et al., 1999). most of the recent tephrostratigraphic studies agree with a campanian ignimbrite origin for the y-5 layer; only paterne et al. (1986, 1988), in fact, still ascribe the tephra to the citara-serrara fontana formation of the ischia island. actually, the attribution of y-5 to the campanian ignimbrite rises also some chronological problems. the deposit has been dated by single crystal high precision 40ar/39ar method to 37.1±0.4 ka b.p. (deino et al., 1992,1994), but new 40ar/39ar geochronology defines the age of the campanian ignimbrite at 39.28±0.11 ka, about 2000 years older than the previous estimate (de vivo et al., 2002). a great deal of 14c dates on paleosols and charbonized wood, available in literature (alessio et al., 1971; 1973; 1974), however, gave an age scattering between 25 and 40 ka b.p. two k/ar dates (curtiss, 1966; cassignol and gillot, 1982) gave an age of 30 and 34.5 b.p. ka, respectively. according to this data some authors believe that the campanian ignimbrite must not be considered as a single eruptive episode, entailing the emplacement of a single pyroclastic flow deposit, but as the result of a series of eruptive episodes, separated by signif icant temporal hiatuses (scandone et al., 1991; calderoni et al., 1993), that brought to the emplacement of the ignimbrite deposit observed in campania. more recently, de vivo et al., 2002, identify on the campanian plain volcanic events other than the campanian ignimbrite, displaying similar field features. the hypothesis of the existence of more than a single volcanic event representing the campanian ignimbrite l.s. is supported by the occurrence, in the tephrostratigraphical record of the central mediterranean area, of more than one ash layer in the 25-40 ka time-span, attributed by paterne et al. (1988) to a "campanian ignimbrite series". a second campanian tephra layer has never been recorded along the tyrrhenian coast, but only detected in some deep sea cores in the ionian sea. the layer, named y-3, displays an extrapolated age of about 25 ka b.p. (narcisi & vezzoli, 1999), is trachytic in composition and has generically been attributed by keller et al. (1978) to the campanian province. paterne et al. (1988), on the contrary, ascribed it to the "campanian ignimbrite series". a late glacial campanian marker tephra layer, labelled c-2 in paterne et al., 1988, has been recorded in the central mediterranean and correlated with the 12 ka b.p. campi flegrei eruption of neapolitan yellow tuff. the main holocene campanian tephra layers are linked to the somma-vesuvio activity. the most diffused marker layers are z-1, correlated to the somma-vesuvio avellino eruption (ca 3800 b.p., rolandi et al., 1998) and the tephra related to the a.d. 79 plinian eruption. they both feel the effect of the different direction of emplacement of fall products, so z-1 is mainly recorded in the east mediterranean, whereas a.d. 79 tephra is better represented in the central mediterranean. the present paper investigates in detail the tephra interbedded to the sedimentary records in two gravity cores of the southern tyrrhenian sea. the aims of the research are: to definitely identify the presence of a single or of more than one tephra layer of campanian origin in the age range 40-25 ka b.p., that encompasses all the 14c dating obtained on paleosols underlaying campanian ignimbrite deposits, to point out the distribution of the tephra layers and, eventually, to hypothesize a source for the pyroclastic products. in this regard, the work investigates gravity cores located near the campanian tyrrhenian coastal area, since the emplacement of campi flegrei and vesuvio products is more probable in this area, and uses sedimentological and biostratigraphic data as a support to chronologically locate the identified tephra layers. the present work is part of a multidisciplinary research that involved, through the last five years, geologists, sedimentologists, palinologists, palaeontologists and volcanologists, aiming to investigate environmental and climatic evolution of the southern tyrrhenian sea through high resolution records. the results of these researches are here reported only when useful to argue tephrostratigraphical conclusions. more detailed information about strictly sedimentological and palaeontological aspects can be found in buccheri et al. 2002a,b. few chemical data on glass shards and preliminary tephrostratigraphical considerations have been reported by one of the authors (r.m.) in buccheri et al. 2002a. the present paper represents a step forward, using new tephra and mineral characterization on the two cores and on-land comparison samples, and revising the upper pleistocene tephrostratigraphical record in the whole tyrrhenian area. 22.. eexxppeerriimmeennttaall 22..11 tteepphhrraa llaayyeerrss iinn tthhee ccoorreess two gravity cores located offshore the campanian tyrrhenian border have been investigated to reconstruct the tephrostratigraphical record of the area. the first core, named c106 (ϕ = 40°29'32'', λ = 14°42'32'', depht = 292 m) is located in the salerno gulf, directly offshore the sele river mouth, and is 6,40 m long. the second core, named c45 (ϕ = 39°45'10'', λ = 15°20'20'', depht = 1053 m) is located in the policastro gulf, in a valley-type depression of the sea floor, about 63 nautical miles sw of sapri town, and is 4.70 m long. figure 1 shows the location of investigated cores together with main deep sea morphological contours. both the cores consist of an alternance of clay, silt, silt-sandy and rare sandy layers, in which the coarse fraction is made up of organic (planktonic and bentonic foraminifers, pteropods) and inorganic material (pumice fragments, quartz and mica crystals). along the cored successions some coarse grained layers, mainly made up of sharp edged pumice fragments and crystals, displaying features of a primary volcanic deposition, have been fully investigated to reconstruct the complete tephrostratigraphical record (fig.2). along the core c106 the first tephra layer has been identified at 55.5 cm from the top and its lower limit is 110.5 cm. the whole thickness is 55 cm. the layer shows a sharp basal contact with the underlying clay layer. the basal part of the pyroclastic layer (110.588.5 cm) consists of whitish pumice fragments (sample a1(a)), overlain by a 10cm thick layer consisting of gray pumice and rare lava lithic fragments (sample a1(b)). both the samples display maximum clasts grain-size greater than 2mm and contain pumice fragments, a minor fraction of lava lithic fragments and rare limestone fragments. the second tephra layer of c106 has been identified at 565 cm from the top of the core and its lower limit is 579 cm. the whole thickness is 14 cm. the layer does not show a sharp basal contact with the underlying clay layer. the layer consists of some sublayers containing white and gray pumice fragments (sample a2), and passes towards the top to a dark clay level. all samples display maximum clasts grain-size greater than 2mm and contain pumice fragments and rare lava lithic fragments. juvenile fraction in both samples was represented by elongated pumice clasts, with very well developed elongated vesicles. along the c45 core three main tephra layers have been recognized. the first one has been identified at 25 cm from the top of the core and its thickness is about 7 cm. the layer is mainly made up of grey pumice fragments sample b1(b), maximum grain size 1 mm and rare lava and limestone lithic fragments, but in the basal part whitish pumice fragments are abundant sample b1(a). the second tephra layer of c45 core is located at 380 cm from the top and is 3 cm thick. it is made up of pumice fragments and glass shards, maximum grain 13new constraints on the occurrence ... size of clasts is 2 mm; no lithic fraction has been detected (sample b2). the third tephra layer is 460 cm deep and 3.5 cm thick. juvenile fraction is represented by glass shards and pumice fragments whose maximum grain-size is 1 mm; very rare lava lithic fragments have also been found (sample b3). mineralogical component percentage evaluation has been performed by counting at least 100 crystals for each level; the results of the analysis are shown in table 1. k-feldspar, biotite and clinopyroxene are almofig.1 map of the salerno and policastro gulfs with main submarine morphological contours and location of investigated cores. carta batimetrica dei golfi di salerno e policastro con l'ubicazione dei gravity cores studiati. table 1 mineralogical component percentage evaluation for all investigated tephra layers. valutazione semiquantitativa delle fasi minerali presenti all'interno dei livelli di tefra. core sample feldspar leucite biotite cpx garnet fe-ti oxides a1 (a) •• •• • c106 a1 (b) •• • • • a2 ••• • • b1 (a) •• •• • c45 b1 (b) •• • • • b2 •• • • • b3 •• • • • • l represents about 20% 14 st ubiquitous phases. only the topmost layer of both cores shows leucite and garnet among the mineral phases. chemical composition of glass fragments and crystal grains was determined by microprobe analysis using e.d.s. system on loose fragments of 0.5 mm grain-size, at cisag (centro interdipartimentale di servizio per analisi geomineralogiche) at university of naples federico ii. with regards to the chemical composition of glasses, the reported one represents a mean composition, obtained from at least ten punctual analyses on different glass shards. chemical composition of all the samples is reported in table 2. as a reference for correlations with the products of volcanic eruptions recorded in the field, table 3 reports the representative analyses of mineral grains for c45 core, chosen because it contains all the recognized tephra layers. the whole set of analytical data on minerals, both for tephra layers in the cores and for comparison samples, are at disposal upon request to the authors. 22..22 ccoommppaarriissoonn aannaallyysseess in order to better clarify the possible correlations, chemical analyses other than on the c106 and c45 pyroclastic layers have been performed. the comparison samples have been selected among the most widespread campi flegrei and somma vesuvio eruptions products ranging in age between about 40 and the present. the age range has been chosen taking into account the 14c ams dating that provided the chronostratigraphic framework for both cores, as reported in buccheri et al. (2002a,b) and in figure 2. the first comparison sample is represented by pumice fragments extracted from the pyroclastic fall layer directly underlaying the ignimbrite campana grey tuff at cologna, ne of salerno. the other comparison samples are represented by the somma-vesuvio codola and pomici di base eruptions products (rolandi, 1997), samples courtesy of prof. giuseppe rolandi. apart from this, to better define the characteristics of y-3, prof. keller has been asked a little sample of the fig. 2 stratigraphic succession of c45 and c106 core with interbedded tephra layers and thickness of tephra layers. *data from buccheri et al., 2002a;**data from buccheri et al., 2002b; nc = not calibrated. successione stratigrafica delle carote c45 and c106 con indicazione dei livelli di tefra intercalati e dei relativi spessori. *dati da buccheri et al., 2002a;**dati da buccheri et al., 2002b; nc = età non calibrata. r. munno & p. petrosino 15 layer firstly ascribed to y-3, from the core rc9-191 of the ionian sea. the sample has been analysed using the same methods as the unknown layers object of the paper. the analysis of keller et al. (1978) had, in fact, been performed by x-ray fluorescence on a glass enriched sample and, at present, it is well known (rinaldi, 1979; narcisi & vezzoli, 1999) that punctual analytical methods (eds, wds, etc) best suit tephrostratigraphycal problems. the last comparison sample is split into two subsamples respectively of white and grey pumice fragments from the a.d. 79 eruption, extracted from the poggiomarino and zabatta outcrops. it has been analysed since its south-west trending diffusion makes its presence expected in the salerno gulf recent sedimentary record. table 4 reports sem-eds glass compositions for table 2 sem-eds glass composition recalculated to 100 water free of all the investigated tephra samples. n= number of analyses; standard deviation in parentheses. composizione sem-eds del vetro ricalcolata a 100 per i livelli di tefra esaminati. n= numero di analisi; deviazione standard in parentesi. sample c106 c106 c106 c45 c45 c45 c45 a1(a) a1(b) a2 b1(a) b1(b) b2 b3 n 11 10 21 10 12 11 11 sio2 55.36 (0.27) 56.54 (0.19) 62.63 (0.20) 54.86 (0.24) 56.04 (0.32) 62.41 (0.32) 61.53 (0.48) tio2 0.48 (0.05) 0.24 (0.03) 0.34 (0.06) 0.45 (0.08) 0.55 (0.07) 0.33 (0.10) 0.39 (0.06) al2o3 21.01 (0.17) 22.72 (0.28) 18.24 (0.12) 20.74 (0.20) 21.36 (0.14) 18.30 (0.29) 18.73 (0.17) feo* 4.07 (0.16) 2.36 (0.21) 3.15 (0.12) 3.93 (0.11) 3.39 (0.12) 3.17 (0.10) 3.16 (0.19) mno 0.17 (0.08) 0.13 (0.11) 0.15 (0.08) 0.13 (0.04) 0.09 (0.03) 0.15 (0.08) 0.23 (0.07) mgo 0.59 (0.06) 0.11 (0.06) 0.47 (0.08) 1.38 (0.09) 0.48 (0.08) 0.50 (0.09) 0.50 (0.10) cao 4.23 (0.29) 2.98 (0.15) 2.12 (0.10) 4.47 (0.24) 4.06 (0.31) 2.13 (0.10) 1.74 (0.06) na2o 5.83 (0.21) 7.39 (0.64) 4.15 (0.19) 5.37 (0.17) 7.13 (0.21) 4.30 (0.15) 6.05 (0.33) k2o 8.28 (0.44) 7.54 (0.76) 8.75 (0.14) 8.67 (0.29) 6.90 (0.30) 8.71 (0.08) 7.67 (0.21) d.i. 79.56 86.03 86.82 77.40 81.75 86.95 89.53 ne 22.10 24.89 0.00 22.78 22.88 1.07 8.24 feo* = total fe as feo feo* = total fe as feo table 3 representative microprobe analyses of mineral phases extracted from c45 core tephra layers. analisi in microsonda dei minerali rappresentativi estratti dai livelli di tefra della carota c45. leucite k-feldspar cpx cpx biotite amphibole sio2 54.50 63.48 51.18 43.96 36.00 33.68 tio2 0.11 0.10 0.43 1.55 3.53 1.89 al2o3 22.76 18.81 2.36 8.30 15.50 15.21 feo* 0.37 0.09 4.65 11.05 11.65 24.84 mno 0.02 0.05 0.12 0.12 0.08 1.02 mgo 0.08 0.18 16.22 10.26 18.03 4.30 cao 0.12 0.33 23.85 23.58 0.00 11.55 na2o 0.83 1.23 0.44 0.46 0.49 1.47 k2o 20.51 15.03 0.00 0.00 10.33 3.37 total 99.30 99.30 99.25 99.28 95.61 97.33 b1 (a-b) b2 k-feldspar cpx biotite magnetite sio2 63.60 49.31 35.81 0.29 tio2 0.13 0.57 4.56 6.23 al2o3 18.88 3.77 14.50 2.56 feo* 0.23 8.31 14.49 80.91 mno 0.03 0.36 0.23 0.87 mgo 0.13 13.53 15.41 1.58 cao 0.55 23.00 0.00 0.06 na2o 1.84 0.53 0.56 0.10 k2o 13.95 0.00 9.84 0.04 total 99.34 99.38 95.40 92.64 b3 k-feldspar cpx biotite amphibole magnetite sio2 63.58 49.01 35.40 38.15 0.36 tio2 0.24 0.49 4.79 1.94 5.22 al2o3 18.87 2.97 15.06 12.20 4.11 feo* 0.27 11.28 13.89 19.54 79.73 mno 0.02 0.71 0.17 0.48 0.57 mgo 0.07 11.31 15.70 8.83 2.58 cao 0.48 22.83 0.00 11.84 0.00 na2o 1.82 0.79 0.53 1.57 0.40 k2o 14.12 0.03 10.02 2.77 0.00 total 99.48 99.42 95.56 97.32 92.97 new constraints on the occurrence ... 16 the comparative samples. figure 3 reports the tas classif icative plot (le maitre, 1989) for the investigated tephra layers and the comparison samples, and figure 4a reports the di-ne plot of armienti et al. (1983), more apt to the slighty saturated and alkali-rich rocks of campanian area. 33.. rreessuullttss aanndd ddiissccuussssiioonn the modal and chemical compositions of pyroclastic layers, identified in the two gravity cores, show two compositional fields, phonolitic s.l. and alkali-trachytic. the presence of a phonolitic layer table 4 sem-eds glass compositions recalculated to 100 water free for the comparative samples. n= number of analyses; standard deviation in parentheses. composizione sem-eds del vetro ricalcolata a 100 per i campioni di riferimento. n= numero di analisi; deviazione standard in parentesi. 1 2 3 4 5 6 7 8 n 10 xrf 10 10 8 11 9 15 sio2 61.52 (0.20) 61.78 62.76 (0.36) 57.87 (0.30) 62.45 (0.08) 56.46 (0.25) 54.88 (0.21) 61.01 tio2 0.37 (0.06) 0.44 0.36 (0.03) 0.58 (0.08) 0.35 (0.03) 0.42 (0.05) 0.44 (0.03) 0.40 al2o3 18.88 (0.15) 18.96 18.21 (0.16) 19.16 (0.20) 18.34 (0.08) 21.35 (0.18) 20.67 (0.11) 18.63 feo* 3.06 (0.12) 3.23 2.98 (0.21) 3.90 (0.16) 2.74 (0.14) 3.34 (0.17) 4.09 (0.16) 3.55 mno 0.23 (0.05) 0.17 0.17 (0.12) 0.16 (0.06) 0.13 (0.09) 0.21 (0.10) 0.23 (0.04) 0.05 mgo 0.47 (0.05) 0.59 0.25 (0.12) 0.63 (0.11) 0.35 (0.04) 0.56 (0.09) 0.67 (0.08) 0.77 cao 1.75 (0.08) 1.98 2.07 (0.15) 4.43 (0.46) 2.75 (0.09) 4.05 (0.28) 5.03 (0.17) 2.47 na2o 6.01 (0.24) 5.57 4.44 (0.19) 3.30 (0.27) 4.24 (0.08) 7.17 (0.23) 5.55 (0.15) 2.65 k2o 7.71 (0.20) 7.28 8.75 (0.26) 9.96 (0.54) 8.66 (0.06) 6.45 (0.21) 8.45 (0.28) 9.93 d.i. 89.48 86.86 88.18 78.47 85.98 80.81 77.67 80.77 ne 8.20 3.89 1.28 9.82 1.26 21.24 22.73 0.00 feo* = total fe as feo 11 pumice fragment from campanian ignimbrite pyroclastic fall deposit at cologna (salerno). 22 y-5 tephra from core rc9-191, in keller et al. (1978), recalculated water free. 33 y-3 tephra from core rc9-191, sample courtesy of prof. j. keller. 44 pumice fragment from somma vesuvio codola eruption pyroclastic fall products, sample courtesy of prof. g. rolandi. 55 pumice fragment from somma vesuvio pomici di base eruption pyroclastic fall products, sample courtesy of prof. g. rolandi. 66 white pumice fragment from somma vesuvio ad 79 eruption pyroclastic fall deposit from the poggiomarino outcrop. 77 grey pumice fragment from somma vesuvio ad 79 eruption pyroclastic fall deposit from the zabatta (san giuseppe vesuviano) outcrop. 88 unit c ignimbrite matrix glass from scarafea (signorelli et al., 1999). fig. 3 tas classificative plot for investigated tephra layers and for comparison samples. for comparison samples symbols legend see table 4. diagramma classificativo tas per i livelli di tefra e per i campioni di riferimento. per la legenda dei simboli dei campioni di riferimento vedi tabella 4. r. munno & p. petrosino in the higher part of the c106 (samples a1(a) and a1(b), tab.2) and c45 (samples b1(a) and b1(b), tab.2) core makes it possible to hypothesize the relationship with the somma-vesuvio a.d. 79 eruption (samples 6 and 7, tab.4). the fall phase of this eruption, in fact, was dispersed towards the salerno gulf. besides this, the change in colour (from white to gray) and in composition (from phonolitic to tephry-phonolitic) of pumice fragments is a diagnostic feature for a.d. 79 eruption products. moreover, garnet is a typical mineralogical phase for white pumice fragments as leucite is for gray. the tephra layers alkali-trachytic in composition, found both in c106 and c45, represented by samples a2 and b2 (tab.2), respectively, could be related to somma-vesuvio f irst activity, namely to codola (25.1±0.4 ka b.p. alessio et al., 1974 – sample 4, tab.4) and pomici di base (18.3±0.18 ka b.p. andronico et al., 1995– sample 5, tab.4) eruptions, but also repeat the general chemical features of campi flegrei products. the dispersal of somma-vesuvio codola eruption fall products is, at present, not well known, but the comparison of si/ca ratio in codola and in sample a2 and b2 juvenile fraction makes it possible to exclude the correlation (fig.3, 4). as regards the pomici di base eruption products, even if the chemical composition is quite comparable, reconstructed fall products distribution is towards the ne from vesuvio and not in good agreement with the presence of the layer in the salerno gulf. besides this, the age of pomici di base eruption does not fit the 14c age of 26030±150 y b.p (buccheri et al., 2002a) and of 25570±110 y b.p. (buccheri et al., 2002b) obtained on the microfossils in the clay layer directly underlying the tephra, respectively in the c106 and in the c45 core. this is very reliable since: in c45 core a 14c ams age of 19490±110 y b.p. has been recorded in the clay 70 cm above the pyroclastic layer, in c106 core a calibrated 14c ams age of about 19.7 ka b.p. has been recorded in the clay 100 cm above the pyroclastic layer (see fig.2) no evidence of hiatuses in sedimentation is present along these clay layers. a2 and b2 tephra, however, find a very good correspondence in mineralogical content and chemical composition (tab.4) of y-3 tephra found in the ionian sea. besides this, in core rc9-191, investigated by keller et al. (1978), the dating of sapropels gave an age of about 26.000, well fitting the paleontological age obtained for the same layer in the two cores investigated here. as to the third pyroclastic layer in the c45 core, represented by sample b3, it repeats the composition of the fall products of the campanian ignimbrite eruption sampled at cologna. apart from this, it well resembles the composition of y-5 marker layer as reported in keller et al. (1978), definitely correlated to the campanian ignimbrite in narcisi and vezzoli (1999), and that of the comparison sample. the attribution of lowermost layer to y-5 is consistent with the presence of 25 cm thickness of pelagic sediments between the layer and the clay level dated at about 26 ka b.p. in c45 core, taking into account a sedimentation rate of about 1,7 cm/ka, as deduced by buccheri et al. (2002a). 17 fig. 4 d.i. ne plot for investigated tephra layers and for comparison samples. for comparison samples symbols legend see table 4. diagramma d.i. ne per i livelli di tefra e per i campioni di riferimento. per la legenda dei simboli dei campioni di riferimento vedi tabella 4. new constraints on the occurrence ... 44.. ccoonncclluussiivvee rreemmaarrkkss the results of the tephrostratigraphical investigation of c45 and c106 tephra layers are so summarized: layer b3 of c45, the oldest tephra layer identified, is correlable to the y-5 marker layer and to the campanian ignimbrite basal pumice fall. layer b2 of c45 and layer a2 of c106 represent the product of the same volcanic event and have been correlated to the y-3 marker layer. layer b1(a,b) of c45 and layer a1 (a,b) of c106 represent the pumice fall products of the a.d. 79 sommavesuvio eruption. in order to confirm the presence of two different tephra layers in the 4025 ka time-span, the tephrostratigraphical literature reporting data for primary tephra layers in the tyrrhenian sea has been revised (paterne 1985; paterne et al., 1986; paterne et al., 1988; mccoy and cornell, 1990; calanchi et al., 1994). the revision of data entailed the recovering of all stratigraphical relations, modal compositions and chemical analyses of juvenile fraction and, where available, of mineral phases of tephra layers identified in many cores and new correlations have been made in the light of the obtained results. tab. 5 reports these new correlations that confirm the presence of y-3 tephra layer in southern tyrrhenian sea and along the campanian coast, whereas y-5 results more widely dispersed (fig. 5). 18 fig. 5 sketch map of tyrrhenian sea reporting the occurrence of y-3 and y-5 primary tephra layers, as deduced from the revision of tephrostratigraphic literature regarding the tyrrhenian sea and from present paper data. circles indicate coring sites; black area in the circle indicates the occurrence of y-3 tephra, dashed area in the circle indicates the occurrence of y-5 tephra. for core references see table 5. schema del mar tirreno che riporta la presenza dei livelli marker y-3 and y-5, dedotta dalla revisione della letteratura riguardante la tefrostratigrafia del tirreno e da dati del presente lavoro. i cerchi indicano l'ubicazione delle carote; l'area nera nel cerchio indica la presenza all'interno della carota del marker y-3, l'area tratteggiata nel cerchio indica la presenza all'interno della carota del marker y-5. per il riferimento alla carota vedi tabella 5. table 5 sem-eds glass composition of y-3 and y-5 tephra layers occurring in the tyrrhenian sea. composizione sem-eds dei vetri dei livelli di tefra y-3 and y-5 reperiti in alcune carote del mar tirreno. y-5 y-5 y-5 y-5 y-3 y-3 y-3 core ket 8003 ket 8004 ket 8011 ket 8022 ket 8003 ket 8004 ket 8011 ° ° °° ° ° ° °° sio2 62.29 62.46 61.90 63.19 60.42 60.59 59.90 tio2 0.36 0.36 0.34 0.00 0.40 0.23 0.36 al2o3 19.54 19.59 19.63 19.45 20.18 20.08 20.19 feo* 2.75 2.49 2.58 2.66 2.34 2.43 2.46 mno n.d. n.d. n.d. n.d. n.d. n.d. n.d. mgo 0.11 0.11 0.12 0.00 0.08 0.04 0.07 cao 1.63 1.63 1.88 1.73 3.38 3.16 3.56 na2o 5.99 6.01 5.86 5.69 3.92 4.39 4.59 k2o 7.33 7.35 7.69 7.27 9.28 9.08 8.87 ° in paterne et al., 1986 °° in paterne, 1985 feo* = total fe as feo r. munno & p. petrosino the presence of two alcali-trachytic tephra layers offshore the tyrrhenian coast, namely b2 and b3 in c45, separated by the deposition of pelagic sediments, makes it possible to hypotesize, in the 40-25 ka b.p. time span, the occurrence of two distinct intense volcanic events with a widely dispersed associated fall phase. the different age, together with the slightly different chemical composition, suggests that no link exists between them, apart from the source. the lower layer (b3 in c45) is well linkable to the campanian ignimbrite eruption, that we can now term first campanian ignimbrite, and its presence in the policastro gulf core well agrees with the distribution hypothesized for the associated fall phase by rosi et al. (1999). the sequence cored in c106, offshore the sele river mouth, where no record of y-5 has been found, probably stops before encountering this tephra layer. the topmost alkali-trachytic layer (a2 in c106 and b2 in c45) tesifies to the presence of the y-3 marker layer in the tyrrhenian area, and no clear attribution to a recognized volcanic event is at present possible. however, it can be interpreted as the record of an eruptive event from the campanian area. the absence of a somma-vesuvio eruption as the origin of the layer, restricts the field of possible sources to campi flegrei. chemical features of y-3 are quite peculiar, and distinguish it from y-5, here definitely linked to campanian ignimbrite. it can be concluded that the presence of this layer accounts for the hypothesis that what is found in the field and ascribed to the campanian ignimbrite eruption may be the result of at least two distinct eruptive episodes, each with an associated fall phase. y-3 can be considered the record of another eruptive event, that we term second campanian ignimbrite eruption. the occurrence in volcanological literature of 14c dating ranging between 40 and 25 ka can so be read as the result of the sampling of different paleosoil, underlying somewhere the older, elsewhere the younger pyroclastic deposit. as to the chemical composition, a slight chemical difference in the composition of campanian ignimbrite units has been detected by signorelli et al. (1999). according to these authors, the last unit of c.i. (sampled in the northern area of naples, giugliano municipality, in a quarry at the scarafea locality) is much richer in k than the first one and seems well to resemble the composition of y-3. we hypothesize that this unit can be the pyroclastic flow associated to the fall phase emplacing y-3. this hypothesis can be supported by the recorded presence of a paleosol between the campanian ignimbrite tuff and the topmost pyroclastic flow deposit at giugliano and by the 40ar/39ar dating of the same deposit, that results much younger than campanian ignimbrite (rolandi et al., 2003). at present more field studies are necessary, aimed at mapping the two different ignimbrite deposits linked to y-5 and y-3 tephra marker layers. aacckknnoowwlleeddggmmeenntt this research, within the project "impact of natural events on biotic communities in the last 20 ka bp climatic and volcanic events", was supported by prin 1998, chief scientist prof. g. ciampo. prof. t.s. pescatore kindly offered the c106 core. the authors wish to gratefully thank prof. j. keller, who kindly supplied a tephra sample from core rc9191, and prof. g. rolandi, for supplying some comparison samples. prof. l. lirer is thanked for reading an early draft of the paper. rreeffeerreenncceess alessio m., bella f., improta s., belluomini g., cortesi c. & turi b., 1971 university of rome carbon-14 dates ix. radiocarbon, 1133--22, 395-411. alessio m., bella f., improta s., belluomini g., calderoni g., cortesi c. & turi b., 1973 university of rome carbon-14 dates x. radiocarbon, 1155--11, 165-178. alessio m., bella f., improta s., belluomini g., calderoni g., cortesi c. & turi b., 1974 university of rome carbon-14 dates xii. radiocarbon, 1166--33, 358-367. andronico d., calderoni g., cioni r., sbrana a., sulpizio r. & santacroce r., 1995 geological map of somma-vesuvio volcano. period. mineral., 6644((11--22)), 77-78. armienti p., barberi f., bizouard h., clocchiatti r., innocenti f., metrich m., rosi m. & sbrana a., 1983 the phlegraen fields: magma evolution within a shallow chamber. j. volcanol. geotherm. res., 1177, 89-311. barberi f., innocenti f., lirer l., munno r. & pescatore t.s., 1978 the campanian ignimbrite: a major prehistoric eruption in the neapolitan area (italy). bulletin volcanologique, 4411,1-22. buccheri g., bertoldo g., coppa m.g., munno r., pennetta m., siani g., valente a. & vecchione c., 2002a studio multidisciplinare della successione sedimentaria tardo-quaternaria proveniente dalla scarpata continentale del golfo di policastro (tirreno meridionale). boll. soc. geol. it., 112211, 187-210. buccheri g., capretto g., di donato v., esposito p., ferruzza g., pescatore t., russo ermolli e., senatore mr., sprovieri m., bertoldo m., carella d. & madonia g., 2002b a high resolution record of the last deglaciation in the southern tyrrhenian sea: environmental and climatic evolution. marine geology, 118866,, 447-470. calanchi n., gasparrotto g. & romagnoli c., 1994 glass chemistry in volcaniclastic sediments of odp leg 107, site 650, sedimentary sequence: provenance and chronological implications. j. volcanol. geotherm. res., 6600,, 59-85. calderoni g., vesica p. & turi b., 1993 radiocarbon dating of the campanian ignimbrite (tufo grigio campano auct.): towards a definition of the main emplacement phase. symposium "quaternary stratigraphy in volcanic areas", roma, september 20-22. abstracts, 17. cassignol c. & gillot p., 1982 range and effectiveness of unspiked potassium-argon dating: experimental ground work and application. in g.s. odin (ed.) "numerical dating in stratigraphy",160-179. curtiss g.h., 1966 the problem of contamination in obtaining accurate dates of young geologic rocks. 19new constraints on the occurrence ... in: oa shaeffer and j zahringer eds. potassium argon dating, springer berlin. deino a.l., courtis g.h. & rosi m., 1992 40ar/39ar dating of campanian ignimbrite, campanian region, italy. int geol congr kioto, japan, abstracts, vol 3, p 2654. deino a.l., courtis g.h., southon j., terrasi f., campaiola l. & orsi g., 1994 14c and 40ar/39ar dating of the campanian ignimbrite, phlegraean fields, italy. abstracts icog, berkley, ca, u.s.a. de vivo b., rolandi g., gans p.b., calvert a., bohrson w.a., spera f.j. & belkin h.e., 2002 new constraints on the pyroclastic eruptive history of the campanian volcanic plain (italy). mineralogy and petrology, 7733, 47-65. fisher r.v., orsi g., ort m. & heiken g., 1993 mobility of large-volume pyroclastic flow emplacement of the campanian ignimbrite, italy. j. volcanol. geotherm. res., 5566, 205-220. keller j., ryan w.b.f., ninkovich d. & altherr r., 1978 explosive volcanic activity in the mediterranean over the past 200,000 years as recorded in deepsea sediments. bull. geol. soc. am., 8899, 591-604. le maitre r.w. ed, 1989 a classification of igneous rocks and glossary of terms. blackwell scientific publications, oxford, 193 pp. mccoy f.w. & cornell w., 1990 volcaniclastic sediments in the tyrrhenian basin. proc. ocean drilling program, 110077, 291-306. narcisi b. & vezzoli l., 1999 quaternarnary stratigraphy of distal tephra layers in the mediterranean-an overview. global and planetary change, 2211, 31-50. paterne m., 1985 reconstruction de l'activitè explosive des volcans de l'italie du sud par téphrochronologie marine. thèse dr. sciences paris-sud., 144 pp. paterne m., guichard f., labeyrie j., gillot py. & duplessy j.c., 1986 tyrrhenian sea tephrochronology of the oxygen isotope record for the past 60,000 years. marine geology, 7722, 259-285. paterne m., guichard f. & labeyrie j., 1988 esplosive activity of the south italian volcanoes during the past 80,000 years as determined by marine tephrochronology. j. volcanol. geotherm. res., 3344, 153-172. rinaldi r., 1979 la microanalisi elettronica: strumentazione e applicazioni mineralogico-petrografiche. rend. soc. it. min. pet., 55((22)), 507-526. rolandi g., 1997 the eruptive history of sommavesuvius. in: volcanism and archaeology in mediterranean area (cortini m. and de vivo b. eds.). research signpost, trivandrum, india 7788. rolandi g., petrosino p. & mcgeehin j., 1998 the interplinian activity at somma-vesuvius in the last 3500 years. j. volcanol. geotherm. res., 8822, 1952. rolandi g., bellucci f., heizler m.t., belkin he. & de vivo b., 2003 tectonic controls on the genesis of ignimbrites from the campanian volcanic zone, southern italy. mineralogy and petrology, 7799, 331. rosi m., vezzoli l., aleotti p. & de censi m., 1996 interaction between caldera collapse and eruptive dynamics during the campanian ignimbrite eruption, phlegraean fields, italy. bull. volcanol., 5577, 541-554. rosi m., vezzoli l., castelmenzano a. & grieco g., 1999 plinian pumice fall deposit of the campanian ignimbrite eruption (phlegraean fields, italy). j. volcanol. geotherm. res., 9911((22-44)), 179-198. scandone r., bellucci f., lirer l. & rolandi g., 1991 the structure of the campanian plain and the activity of the neapolitan volcanoes (italy). j. volcanol. geotherm. res., 4488, 1-31. signorelli s., vagelli g., francalanci l. & rosi m., 1999 origin of magmas feeding the plinian phase of the campanian ignimbrite eruption, phlegrean fields (italy): constraints based on matrix-glass and glass-inclusion compositions. j. volcanol. geotherm. res., 9911((22--44)), 199-220. thunell r., federman a., sparks s. & william d., 1979 the age, origin, and volcanological significance of the y-5 ash layers in the mediterranean. quaternary res., 1122, 241-253. vezzoli l., 1988 island of ischia. cnr, quaderni della ricerca scientifica 10, roma, 132 pp. 20 ms. ricevuto il 15 luglio 2003 testo definitivo ricevutol’11 novembre 2003 ms. received: july 15, 2003 final text received: november 11, 2003 r. munno & p. petrosino sess 2_16022011_tpr3.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 investigating evidences of quaternary glaciations in the prealpine environment of the astico valley sandro rossato 1, giovanni monegato 2 & paolo mozzi 1 1 university of padua, department of geography, padova (italy) 2 university of padua, department of geoscience, padova (italy) corresponding author: s. rossato <sandro.rossato@unipd.it> abstract: rossato s., monegato g. & mozzi p., investigating evidences of quaternary glaciations in the prealpine environment of the astico valley. (it issn 0394-3356, 2011) in the astico valley (venetian prealps) some glacial, fluvioglacial and glaciolacustrine deposits were found. they are attributed to a pre-lgm glacial advance which reached further out in the valley. geomorphological and stratigraphic data support this hypothesis. it is also pointed out the presence of a tectonic guidance in the developing of the astico fluvial network. riassunto: rossato s., monegato g. & mozzi p., studio di affioramenti attribuibili a glaciazioni quaternarie nell’ambiente prealpino della valdastico. (it issn 0394-3356, 2011) nella valdastico (prealpi venete) sono state rinvenute prove di un’avanzata glaciale precedente il lgm, che ha raggiunto posizioni più avanzate rispetto a esso. i dati geomorfologici e stratigrafici finora raccolti concorrono alla caratterizzazione e interpretazione di questi depositi. emerge inoltre un probabile controllo tettonico sullo sviluppo dell’attuale forra del fiume astico. key words: quaternary glaciations, astico valley, sand petrography parole chiave: glaciazione, astico, petrografia delle sabbie.  cogollo del cengio village, almost at the beginning of the canyon. other glacial deposits are scattered along the valley up to the northern watershed, where a low-elevation saddle divides the astico basin from the larger brenta river catchment. the terminal part of the astico valley presents an interesting situation, according to the geomorphological and geological configuration. the river flows in the canyon before described instead of entering the piedmont alluvial plain through the large gap (approximately 2.5 km wide) between piovene rocchette and chiuppano. according to the geological setting, the direction followed by the astico river seems even more strange. in fact, the canyon is cut in hard mesozoic -cenozoic carbonates and volcanic rocks, whereas the gap is made of easily erodible quaternary gravels, deposited by the astico river itself during the late pleistocene (cucato, 2001). during field survey, previously unknown glacial, fluvioglacial and glaciolacustrine deposits were found in the canyon about 4.5 km south of the lgm terminal moraines. remote sensing was applied in the early steps of the research, in order to define the main landforms and related sedimentary bodies and calibrate the field survey. aerial photographs and satellite images were used, along with some oblique images, taken from a light aircraft. also, a digital terrain model (dtm) was realized the astico valley is located in the venetian prealps (eastern southern alps), nw of the city of vicenza (italy). the valley is named after the astico river, which has its source between the sommo alto and the plaut peaks, and flows initially n/s and then nw/ se. the river flows on the valley bottom up to the village of piovene rocchette, where it enters a narrow and 50-m deep canyon until reaching the venetian alluvial plain, about 10 km downstream. the valley is cut mostly in triassic to cretaceous limestones and dolostones, triassic and cenozoic volcanic rocks; the latter can be found in the final reach of the valley, which is carved almost entirely in oligocenic volcanic rocks, both intrusive and effusive. concerning the tectonic aspects, the whole area is interested by two main deformative systems related to the neoalpine tectonic phase (castellarin & cantelli, 2000). they are the “giudicariense” system (oriented sse/nnw) and the “scledense” system (oriented se/nw), which cuts the previous one with a left-strike-slip cinematic. in addition, a third system (oriented roughly e-w) is related to the thrust propagation front of the eastern southern alps towards sse. concerning the quaternary succession, the presence of terminal moraines, attributed to the last glacial maximum (lgm) (cucato, 2001), is well documented since the late 19th century (e.g.: negri, 1887). these deposits are located near the 126 128 127 using elevation data from the carta tecnica regionale (ctr) maps at scale 1:5000. attention was paid to the elimination of artifacts (streets, built-up areas, etc) from the dtm. according to starting datum (contour lines spacing 5 m), the accuracy can be estimated as about the same value. basing on the remote sensing initial results, an intense field survey was run. a key site was the stratigraphic section “ponte dei granatieri”, about 43 m high and 35 m wide, where the following 6 different sedimentary bodies were recognized: a: sand layer at least 2.5 m thick (lower boundary not visible), constituted by sand bodies showing crossto planar-lamination. grain size varies from fine to coarse sand. this layer was deposited in a low-energy fluvial environment. b: conglomeratic layer of about 6 m, mainly made by rounded limestone clasts (0.5 cm < b-axis < 20 cm), locally organized in channel structures. this body is heteropic with c and d layers, in the upper boundary; while, the lower boundary is subhorizontal and abrupt, with erosive structures. this level could be attributed to a braided-type fluvial environment. c: it is 3-m thick and consists of fine to medium sand; this layer can be observed only in the eastern part of the section, where it is inclined up to 60°. the lower boundary is visible only in a small part of the section: it is abrupt and inclined of about 60°-70°. this strata is interpreted as a lowenergy fluvial deposit, possibly passing upwards to a lacustrine delta (see d layer). as for the sedimentary body d, the high inclination is interpreted as the result of sedimentary collapse due to deglaciation of a contiguous ice mass. d: 8,45 m thick, this layer consists of laminated grey clay. the laminas show a variable inclination from sub-horizontal to 60°, moving from west to east in the section. the lower limit is gradual, with an increase of the grain size up to the medium sand. these deposits are lacustrine. looking in detail, the inclination appears to be caused by a collapse and points to a glacio-lacustrine setting, exposed to soft-sediment deformation during deglaciation, due to the lack of lateral support by the shrinking ice-mass. e: this layer is made of clay and gravelly interbeddings, with thickness varying from 0.3 m to 2.5 m. the former are mainly made of red clay (7,5yr 6/6 munsell colour), the latter are made of sub-rounded to angular clasts, whose size varies from 2 to 8 cm (b-axis). the lower boundary is abrupt and plain. as a whole, this unit can be interpreted as slope deposits made of terra rossa soil sediments, eroded from the above valley flanks, alternated with scree deposits made of limestone clasts. f: the uppermost layer is constituted by a ca. 21-m thick carbonate heterometric conglomerate (average pebble dimensions of 3-5 cm,with boulders up to 60 cm), crudely bedded and matrixsupported; clasts are angular to sub-rounded. the upper half is slightly more resistant to erosion, due to cementation. the lower limit is gradual, plain. the sedimentary body is interpreted as an alluvial deposit related to a proximal fan. in order to carry out pollen analysis the lacustrine deposits were sampled. pollen analysis is a good environmental proxy (moore et al., 1991) and may validate the hypothesis that the lake formed in a glacial environment. analyses are currently under way and results are not yet available. some more precise age constraints will be fig. 1, terminal part of the astico valley floor (dtm, hillshade elaboration). ll fondovalle della porzione terminale della valdastico (elaborazione hillshade da dtm).  investigating evidences of quaternary glaciations ... prealpine 128 ms. received: testo ricevuto il has been guided by fractures and faults related to the neoalpine phase, aligned along the southern alpine thrusts front, and that it developed on long time-scales, possibly encompassing large part, if not the totality, of the pleistocene. references  castellarin a. & cantelli l. (2000) neo-alpine evolution of the southern eastern alps. journal of geodynamics, 30, 251 274. cucato m. (2001) rilevamento della media val d'astico (provincia di vicenza): saggio per l'applicazione della normativa sulla cartografia geologica del quaternario continentale, boll. serv. geol. it., 115, 99-130, (1996) 1 tav. f.t. currie l.a. (2004) the remarkable metrological history of the radiocarbon dating [ii]. j. res. natl. inst. stand. technol., 109 (2), 185-217. moore p.d., weeb j.a. & collinson m.e. (1991), pollen analysis, blackwell scientific, oxford. negri a. (1887) l'anfiteatro morenico dell'astico e l'epoca glaciale nei sette comuni. atti del regio istituto di ss.ll.aa., 6 (5), 589-634. preusser f., blei a., graf h. & schlüchter c. (2007) luminescence dating of würmian (weichselian) proglacial sediments from switzerland: methodological aspects and stratigraphical conclusions. boreas, 36 (2), 130-142. wintle a.g. (2008) luminescence dating: where it has been and where it is going. boreas, 37 (4), 471-482. hopefully provided in the next months by luminescence dating. this dating method is based on the accumulation of electrons in the crystalline reticulate defects, leading to the burial time of the sediment (wintle, 2008). even if the luminesce dating is not yet of common use, there are some encouraging studies on proglacial sediments (e.g: preusser et al, 2007). the better known method of c14 is inapplicable, due to the lack of organic material; moreover ages may easily go beyond the resolution limit (currie, 2004). in order to distinguish various sedimentary events, some petrographic analysis were run, both in the described section and in some others. looking at the abundance of dolomitic and calcareous components it was possible to distinguish the fluvial deposits (richer in carbonates) from the glacial/fluvioglacial ones, in which volcanic/ metamorphic rock fragments are more abundant. these elements support the hypothesis that there was a connection between the astico and brenta glaciers, but they are not enough to provide a univocal conclusion. all the elements point to a pre-lgm glacial advance of the astico glacier, which reached further out in the valley. without any other chronological data it is not possible to hypothesize the age of the event (mis 6 or older?). nevertheless, it is clear that the canyon of the astico valley already existed before this glacial advance took place. it is likely that its formation s. rossato, g. monegato & p. mozzi january 15, 2011 15 gennaio 2011 imp.ciaranfi.ioniano il piano ioniano del quaternario mediterraneo neri ciaranfi 1*, fabrizio lirer2, patrizia maiorano1, maria marino1 & simona stefanelli1 * autore corrispondente <neri@geo.uniba.it> 1dipartimento di geologia e geofisica, università di bari 2iamc-cnr, napoli abstract: n. ciaranfi, f. lirer, p. maiorano, m. marino & s. stefanelli, the ionian stage in the mediterranean quaternary. the ionian, that corresponds to the middle pleistocene chronostratigraphic time span, is a new stage that extends from matuyamabrunhes reversal, at 0.78 my near to the marine isotope stage 19, up to the middle-late pleiestocene boundary at 0.13 my in correspondence with the base of mis 5. the ionian stratigraphic interval consists in two different parts: the lowest outcrops are well represented on land in two stratigraphic sections in the crotone basin in calabia and in the montalbano ionico area in basilicata. the portion younger than mis 15 is well represented in a core continuosly drilled in the sicily channel ( kc 01b). parole chiave: quaternario, depositi marini, cronostratigrafia . keywords: quaternary, marine deposits, chronostratigraphy. il quaternario italian journal of quaternary sciences 21(1a), 2008 29-34 lo ioniano, la cui denominazione è stata proposta nel corso del workshop organizzato tra il 29 settembre ed i l 4 ottobre 1994 dal gruppo di studio sul quaternario della commissione italiana di stratigrafia, rappresenta l'intervallo cronostratigrafico corrispondente al pleistocene medio (cita & castradori, 1994; 1995; van couvering, 1995; cita et al., 2006). in accordo con l'uso informale di questo termine, che è ormai stato ampiamente utilizzato nella letteratura sia italiana che internazionale, il piano ioniano si estende dal limite matuyama-brunhes, pressoché coincidente con il mis (marine isotope stage) 19, fino alla base del mis 5, che corrisponde all'inizio del pleistocene superiore (vai, 1996; cita et al., 2005; cita et al., 2006): copre quindi un intervallo di tempo compreso fra circa 0.78 ma e circa 0.13 ma. il termine ioniano, seppur proposto da pochi anni, è riportato in alcune delle più recenti scale cronostratigrafiche (gibbard & kolfschoten, 2004; gibbard et al., 2004; 2005; 2007). il suo uso è stato ribadito al recente congresso internazionale dell'inqua (pillans, 2007), sebbene non sia stata ancora formalmente individuata la sezione stratigrafica nella quale definire il gssp di questo piano. a tale scopo, sia in occasione del congresso inqua 2007 che del workshop della commissione italiana di stratigrafia (fist 2007), sono state proposte la sezione di valle di manche, nel bacino crotonese, e la sezione di montalbano ionico, nell'avanfossa sudappenninica in basilicata. l'intervallo stratigrafico compreso fra 0.78 ma e 0.13 ma è rappresentato nelle due successioni in terra sopra citate e in diversi pozzi (figs. 1 e 2) perforati durante le crociere ocean dril l ing program nel mediterraneo (odp leg 107, 160, 161); in particolare solo la parte inferiore dello ioniano è esposta nelle sezioni affioranti di valle di manche e di montalbano fig. 1. ubicazione delle sezioni in terra e di alcuni dei pozzi perforati nel mediterraneo che meglio rappresentano il piano ioniano. modificata da cita et al. (2006). location of the land sections and of some well drilled in the mediterranean in which the ionian stage is better exposed. modified by cita et al. 82006). ionico, le quali includono rispettivamente i mis dal 22 al 18 (capraro et al., 2005) e i mis dal 22 al 15 (ciaranfi et al, 2001) (fig. 3). la parte più recente dello ioniano, a causa della cessazione del ruolo di avanfossa subsidente nel corso del pleistocene medio (ciaranfi, 2004) 30 n. ciaranfi et al. fig. 2. successioni stratigrafiche maggiormente significative per gli intervalli calabriano e ioniano nell'area mediterranea (da cita et al., 2006, modificata). the detailed studied stratigraphic successions of the mediterranean area in which calabrian and ionian stages are well rprsented. from cita et al. (2006), modified. dell' area bradanico-ionica e dell' emersione subita nel corso dello stesso pleistocene medio/ pleistocene superiore, non è osservabile in affioramento, salvo alcune sezioni stratigrafiche di spessore assai modesto che affiorano nell'entroterra del golfo di taranto e che rappresentano la parte sommitale di questo piano, al passaggio con il sovrastante tarentiano (cita & castradori, 1995). l'intervallo stratigrafico compreso fra gli stadi isotopici mis 15 e mis 5e è invece ben rappresentato nei site 653, 963, e 964 e, in particolare, nella carota kc01b (figs. 2 e 3) che è stata recentemente ricalibrata su base astronomica (lourens, 2004). un'accurata stratigrafia integrata basata su biostratigrafia del plancton calcareo (foraminiferi e nannofossili), stratigrafia isotopica dell'ossigeno e stratigrafia a sapropel, è disponibile per le successioni in pozzo (rio et al ., 1990; castradori, 1993; sprovieri et al., 1998; di stefano, 1998; de kaenel et al., 1999; kroon et al., 1998; rossignol-strick & paterne, 1999; lourens, 2004; maiorano & marino, 2004; raffi et al., 2006). inoltre, anche le successioni in terra risultano ben inquadrate in un preciso schema biocronostratigrafico, come documentato da recenti lavori sia per la sezione di valle di manche (rio et al., 1996; massari et al, 2002; capraro 31il piano ioniano del quaternario mediterraneo et al., 2005), che per la sezione di montalbano ionico (ciaranfi et al., 2001; ciaranfi & d'alessandro, 2004; maiorano et al, 2004; stefanelli et al., 2005). la sezione di valle di manche (fig. 3) è parte di una successione composita caratterizzata da sedimenti che mostrano una complessiva tendenza alla superficializzazione, da mudstones di scarpata a depositi da marini marginali a continentali (massari et al., 2002; capraroet al, 2005); la sezione, in particolare, contiene un livello tefra (pitagora ash) in prossimità del quale è stato riconosciuto il limite paleomagnetico matuyama/ brunhes (rio et al., 1996; massari et al., 2002). la sezione di montalbano ionico è rappresentata da sedimenti che mostrano una tendenza regressiva da piattaforma esterna fino a spiaggia sommersa (ciaranfi et al., 1997; ciaranfi et al., 2001) come evidenziato anche dalle associazioni di organismi macrobentonici (d'alessandro et al., 2003) e di foraminiferi bentonici (stefanelli, 2003), ed include diversi livelli vulcanoclastici (fig. 3). l'insieme dei dati stratigrafici disponibili, ossia il record del δ18o, la biostratigrafia a nannofossili calcarei e i livelli sapropelitici correlati con la stratigrafia a sapropel di lourens (2004) hanno consentito di ottenere una calibrazione astronomica della successione fig. 3. caratteri stratigrafici delle sezioni di valle di manche e di montalbano ionico e correlazione con la carota kc01b per l'intervallo ioniano. valle di manche da capraro et al. (2005); montalbano ionico da ciaranfi et al. (2001); carota kc01b da lourens (2004) main stratigraphic features of the valle di manche and montalbano jonico sections, and their correlation with the ionian succession in the kc01b core. valle di manche from capraro et al. (2005); montalbano ionico from ciaranfi et al. (2001); kc01b core from lourens (2004). 32 f ig . 4 . c a lib ra z io n e a s tr o n o m ic a d e lla s e z io n e d i m o n ta lb a n o i o n ic o e c o rr e la z io n e c o n l a c u rv a d i ri fe ri m e n to d e l δ1 8 o d e l m e d it e rr a n e o d i l o u r e n s e t a l. ( 2 0 0 4 ): v 1 -v 9 = l iv e lli v u lc a n o c la s ti c i; i -5 6 /i -1 1 8 = c ic li d i in s o la z io n e s e c o n d o l o u r e n s e t a l. ( 2 0 0 4 ); b io s tr a ti g ra fi a a n a n n o fo s s ili c a lc a re i d a m a io r a n o e t a l. ( 2 0 0 4 ); f o = f ir s t o c c u rr e n c e ; f c o = f ir s t c o m m o n o c c u rr e n c e ; l c o = l a s t c o m m o n o c c u rr e n c e ; td = t e m p o ra n e a a s s e n z a d i g e p h y ro c a p s a o m e g a ; “i n fl u x g . c ra s s a fo rm is ”. a s tr o n o m ic a l c a lib ra ti o n o f m a o n ta lb a n o j o n ic o s e c ti o n a n d c o rr e la ti o n w it h t h e δ1 8 ° m e d it e rr a n e a n r e fe re n c e c u rv e o f l o u r e n s e t a l. (2 0 0 4 ): v 1 -v 9 = v o lc a n ic la s ti c l a y e rs ; i5 6 /i -1 1 8 = in s o la ti o n c y c le s a c c o rd in g t o l o u r e n s e t a l. ( 2 0 0 4 ); c a lc a re o u s n a n n o fo s s il b io s tr a ti g ra p h y f ro m m a io ra n o e t a l. ( 2 0 0 4 ); f o = f ir s t o c c u rr e n c e ; f c o = f ir s t c o m m o n o c c u rr e n c e ; l c o = l a s t c o m m o n o c c u rr e n c e ; td = t e m p o ra rr y d is a p p e a ra n c e o g g e p h y ro c a p s a o m e g a ; “i n fl u x g . c ra s s a fo rm is ”. n. ciaranfi et al. 33il piano ioniano del quaternario mediterraneo (fig. 4) ed una cronologia dei livelli tefra (ciaranfi et al., submitted). in particolare alcuni dei livelli vulcanoclastici sono stati correlati, sulla base della loro età, con livelli di tefra già riconosciuti nel bacino del mediterraneo e con la loro cronologia come proposta da lourens (2004): v8 (592,29 ka) con il tefra vdd-3 (596±6 ka, karner et al., 1999) e i 29 (595,3 ka, lourens, 2004), v6 e v5 (rispettivamente 618,06 ka e 627,34 ka) sono invece entrambi correlabili con i 30 (622,8 ka, lourens, 2004). inoltre, il livello vulcanoclastico v4, riconosciuto in corrispondenza dello stadio isotopico 19 e probabilmente correlabile con il pitagora ash del bacino crotonese (fig. 3), è stato datato a 785.38 ka, età prossima a quella del limite m/b (fig. 4). bibliografia capraro l., asioli a., backman j., bertoldi r., channell j.e.t., massari f. & rio d. (2005) climatic patterns revealed by pollen and oxygen isotope records across the matuyama/brunhes boundary in central mediterranean (southern italy). geol. soc. of london, spec. publ., 247, 159-182. castradori d. (1993) calcareous nannofossil biostratigraphy and biochronology in eastern mediterranean deep-sea cores: rivista italiana di paleontologia e stratigrafia, 99, 107-126. ciaranfi n. (2004) marine stratigraphy. in crescenti v., d'offizi s., merlino s. & sacchi l., eds, geology of italy. spec. vol. ital. geol. soc. for igc 32 florence 2004, 164-166. ciaranfi n., d'alessandro a. & marino m. (1997) a candidate section for the lower-middle pleistocene boundary (apennine foredeep, southern italy). in naiwen w. & remane j., eds: proc. 30th int. geol. congr., 11, 201-211. ciaranfi n., d'alessandro a., girone a., maiorano p., marino m., soldani d. & stefanelli s.( 2001) pleistocene sections in the montalbano jonico area and the potential gssp for early-middle pleistocene in the lucania basin (southern italy). in ciaranfi n., pasini g., & rio d., eds, the meeting on the plio/pleistocene boundary and the lower/middle pleistocene transition: type areas and sections (bari, 25-29 september 2000). mem. sci. geol., 53, 67-83. ciaranfi n. & d'alessandro a. (2005) overview of the montalbano jonico area and section: a proposal for a boundary stratotype for the lower-middle pleistocene, southern italy foredeep. quater. inter., 131, 5-10. cita m. b., capraro l., ciaranfi n., di stefano e., marino m., rio d., sprovieri r., & vai g. b. (2006) calabrian and ionian: a proposal for the definition of mediterranean stages for the lower and middle pleistocene. episodes, 29, 159-182. cita sironi m. b., capotondi l. & asioli a. (2005) geologia the tyrrhenian stage in the mediterranean: definition, usage and recognition in the deep-sea record. a proposal. rend. fis. acc. lincei, s. 9, 164, 297-310. cita m.b. & castradori d. (1994) workshop on marine sections of gulf of taranto (southern italy) usable as potential stratotypes for the gssp of the lower, middle and upper pleistocene. i l quaternario, 7, 677-692. cita m.b. & castradori d. (1995) rapporto sul workshop “marine sections from the gulf of taranto (southern italy) usable as potential stratotypes for gssp of the lower, middle and upper pleistocene”. boll. soc. geol. it., 114, 319336. d'alessandro a., la perna r. & ciaranfi n. (2003) response of macrobenthos to changes in palaeoenvironments in the lower-middle pleistocene (lucania basin, southern italy). il quaternario, 16, 167-182. de kaenel e., siesser w. g. & murat a. (1999) pleistocene calcareous nannofossil biostratigraphy and the western mediterranean sapropels, sites 974 to 977 and 979. in zahn, r., comas, m.c., klaus, a. (eds.), proc. odp sci. res., 161, 159-181. di stefano e., 1998, calcareous nannofossil quantitative biostratigraphy of holes 969e and 963b (eastern mediterranean). in robertson, a.h.f., emeis, k.c., richter, c. & camerlenghi, a. (eds), proc. odp, sci. results, v. 160, 99-112. gibbard p.l, boreham s., cohen k.m. & moscariello a. (2004) global chronostraigraphic correlation table for the last 2.7 million years. table compiled for the 32° international geological congress of florence gibbard p.l., smith a.g., zalasiewicz j.a., barry t.l., cantrill d., coe a.l., cope j.c.w., gale a.s., gregory f.j., powell j.h., rawson p.f., stone p. & waters c.n. (2005) what status for the quaternary. boreas, 34, 1-6. updated 2007 www.quaternary.stratigraphy.org.uk. karner d.b., mara f. & renne p.r. (1999) 40ar/39ar dating of glacial termination v and duration of the stage 11 highstand. in: poore r.z., burckle l., droxler a.w., mcnulty w.e. (eds.), workshop report. u.s. geol. surv. open-file report, 99312, 35-40. kroon d., alexander i., little m., lourens l.j., mattehewson a., robertson a.h.f. & sakamoto t. (1998) oxygen isotope and sapropel stratigraphy in the eastern mediterranean during the last 3.2 million years. in robertson h.f., emeis k., richter c. et al. (eds), proc. odp sc. res., 160, 181-190. lourens l. j. (2004) revised tuning of ocean drilling program site 964 and kc01b (mediterranean) and implications for the d18o, tephra, calcareous nannofossil, and geomagnetic reversal chronologies of the past 1.1 myr. paleoceanogr., 19, 3010. lourens l., hilgen f., shackleton n. j., laskar j. & wilson d. (2004) the neogene period. in a geological time scale, gradstein f. m., ogg j. g., smith a. g. (eds), cambridge un. press, cambridge, 409-440. maiorano p. & marino m. (2004) calcareous nannofossil bioevents and environmental control on temporal and spatial patterns at the early-middle pleistocene. mar. micropal., 53, 405-422. maiorano p., marino m., di stefano e. & ciaranfi n. (2004) calcareous nannofossil events in the lower-middle pleistocene transition at the montalbano jonico section and odp site 964: ms. ricevuto il 2 aprile 2008 testo definitivo ricevuto il 17 aprile 2008 ms. received: april 2, 2008 final text received: april 17, 2008 34 n. ciaranfi et al. calibration with isotope and sapropel stratigraphy. riv. it. paleont. e strat., 110, 547-557. massari f., rio d., sgavetti m., prosser g., d'alessandro a., asioli a., capraro l., fornaciari e. & tateo f. (2002) interplay between tectonics and glacio-eustasy,pleistocene of the crotone basin, calabria (southern italy). boll. am. geol. soc., 114, 1183-1209. pillans b. (2007) defining the quaternary. xvii inqua congress 2007, cairns convention centre, cairns, australia 28 july 3 august. raffi i., backman j., fornaciari e., pälike h., rio d., lourens l. & hilgen f. (2006) a review of calcareous nannofossil astrobiochronology encompassing the past 25 million years. quat. sci. rev., doi:10.1016. rio d., raffi i. & villa g. (1990) pliocene-pleistocene calcareous nannofossil distribution patterns in the western mediterranean. in kastens ka, mascle j., et al., proceedings of the odp sci. res., 107, 513-532. rio d., channell j.e.t., massari f., poli m.s., sgavetti m., d'alessandro a. & prosser g. (1996) reading pleistocene euastasy in a tectonically active siliciclastic shelf setting (crotone peninsula, southern italy). geology, 24, 743-746. rossignol-strick m. & paterne m. (1999) a synthetic pollen record of the eastern mediterranean sapropels of the last 1 ma: implications for the timescale and formation of sapropels. mar. geol., 153, 221-237. sprovieri r., di stefano e., howell m., sakamoto t., di stefano a. & marino m. (1998) integrated calcareous plankton biostratigraphy and cyclostratigraphy at site 964.proc. odp sci. res., 160, 155165. stefanelli s., 2003. benthic foraminiferal assemblages as tools for paleoenvironmental reconstruction of the early-middle pleistocene montalbano jonico composite section. boll. soc. paleont., 42(3), 281299. stefanelli s., capotondi l. & ciaranfi n. (2005) foraminiferal record and environmental changes during the deposition of the early-middle pleistocene sapropels in southern italy. palaeogeogr., palaeoclim., palaeoecol., 216, 27-52. vai g.b. (1996) revisione critico-storica dei piani marini del quaternario. serv. geol. d'it., miscellanea, vi, 1-179. van couvering j.a. ( 1995) setting pleistocene marine stages. geotimes, 40, 10-11. impaginato atti il quaternario italian journal of quaternary sciences 1155(1), 2002, 121-130 ppeeddoossttrraattiiggrraapphhiicc nnootteess oonn tthhee mmiiddddllee –– llaattee pplleeiissttoocceennee ooff ccaappoo ssaann vviittoo ppeenniinnssuullaa ((nnww ssiicciillyy)) aa.. ccoottttiiggnnoollii11,, gg.. bboosscchhiiaann22,, cc.. ddii mmaaggggiioo11,, ff.. mmaassiinnii11,, dd.. ppeettrruussoo11 1dipartimento di geologia e geodesia, università di palermo, corso tukory, 131, i-90134 2dipartimento di scienze archeologiche, università di pisa, via santa maria, 53 i-56100 pisa this work is supported by grants murst cofin 1997, "risposta dei processi geomorfologici alle variazioni ambientali" (nat. resp. a. biancotti, loc. resp v. agnesi) and by athenaeum grants of palermo university (ex 60%) to f. masini. abstract the available data about quaternary pedostratigraphic of north-western sicily are mainly obtained when fossil vertebrate assemblages are studied. these are often found in caves or in other morphological "traps", where the products of the erosion of soils developed outside these features are redeposited. soils that may have originated these deposits were found on the marine terraces that are typical of the coast areas of sicily. two sequences, called "k22" and "isolidda", that crop out in the north-western side of the san vito lo capo peninsula – to the west of palermo are examined in this work. the first one is a karstic cave infilling, situated near the eastern rim of the old falaise that borders the piana di sopra plateau. two phases were identified in this site. a) transitional environment deposits, with terrigenous input due to the occurrence of alfisols and/or ultisols in the neighbouring area. b) continental deposits, mainly made up of reworked terra rossa, that point to fluctuations of the erosive regime. the aeolian input can be observed throughout the sequence and is apparently stronger in the uppermost levels. this deposition ends at the end of the pleistocene. the second one is a thick sedimentary body that occupies a tectonic depression, near torre isolidda. this sequence is made up of alternating colluvia, éboulis ordonnés and palaeosols dating back to the late pleistocene. the aim of this study is to ascertain which environmental condition affected the deposition of the lithological units of these two sequences and to correlate them to the climatic phases of the middle-late pleistocene. the study of the macroscopic characteristics of the sequences has been carried out in detail with the help of soil micromorphological observations. riassunto le conoscenze pedostratigrafiche relative al quaternario della sicilia nord-occidentale sono legate essenzialmente allo studio delle associazioni fossili a vertebrati che sovente si rinvengono in grotte o in altre "trappole" morfologiche, all’interno delle quali sono stati trasportati e rideposti i prodotti dell’erosione dei suoli che si sviluppavano all’esterno. suoli che potrebbero aver dato origine a questi depositi sono stati segnalati sulle successioni di terrazzi marini che caratterizzano il settore costiero dell’isola. in questo lavoro si esaminano due successioni, denominate k22 e sezione 5 isolidda, affioranti nel settore no della penisola di san vito lo capo, ad ovest di palermo. la prima è costituita dal riempimento di un cavità carsica ubicata in prossimità del margine orientale della paleofalesia che borda il pianoro di piana di sopra; ivi sono state identificate due fasi: a) depositi di ambiente di transizione, con apporti terrigeni dovuti alla presenza di alfisuoli/ultisuoli nelle aree emerse circostanti. b) depositi continentali, costituiti prevalentemente da terre rosse risedimentate che indicano pulsazioni del regime erosivo; l’input eolico, presente in tutta questa fase, diviene più cospicuo nei livelli superiori. questa sedimentazione si conclude con la fine del pleistocene la seconda è un potente corpo sedimentario alloggiato in una depressione di origine tettonica, in località torre isolidda. qui si osserva una successione costituita da alternanze di depositi di colluvio, éboulis ordonnés e paleosuoli ascrivibile al pleistocene superiore. lo scopo di questo lavoro è di individuare le condizioni ambientali che hanno presieduto alla formazione degli orizzonti delle due serie stratigrafiche e di mettere in relazione questi ultimi alle fasi climatiche del pleistocene medio-superiore. a tal fine lo studio delle caratteristiche macroscopiche e la ricostruzione di dettaglio delle serie è stata integrata con i dati derivanti dall’analisi micromorfologica in sezione sottile. parole chiave: pedostratigrafia, quaternario, aree costiere key words: pedostratigraphy, quaternary, coastal areas 11.. iinnttrroodduuccttiioonn several sedimentary sequences containing soils, palaeosols and their relicts were preserved in the capo san vito peninsula, mainly in its western sector, because of the relative tectonic stability of this area. these sequences are mainly preserved within caves or in other morphological traps; they were shortly described by di maggio et al. (1999) in a previous work concerning the seven orders of marine terraces of the peninsula, and the fossil vertebrate assemblages which are frequently found within these sequences. (fig. 1) the aim of this note is to give further insight in the reconstruction of the middle–late pleistocene environmental conditions by a pedostratigraphic approach, highlighting the role of the climatic fluctuations in the change of the sedimentary and soil-forming processes. special emphasis is given to two of the outcropping sequences, which are reasonably thick and can be dated by their faunal content and/or through geomorphological evidences that can be correlated to the sequence of the marine eustatic fluctuations and to the oxygen stable isotope climatostratigraphy. (fig. 1). the l i thological units (sensu orombelli, 1971) of the sequences are described according to the guidelines of sanesi (1977) and catt (1990), while the descriptive criteria adopted for the soil micromorphological features follow the standard proposed by bullock et al. (1985). the c/f limit is set to 10 mm in the soil micromorphological descriptions. 22.. tthhee ""kk2222"" sseeqquueennccee this 9 m thick sequence infills a karst cavity located on the eastern edge of an ancient wave – cut cliff contouring the wide abrasion surface of the 1st order terrace, called piana di sopra (fig. 2). a large part of the cavity, of its entrance and of its infilling, were destroyed by a quarry whose cut advanced parallel to the cliff, so that the original shape of the cave cannot be observed. apparently, the original entrance of the cavity was situated on the top of the abrasion surface, very close to where the edge of the terrace is now. however, the present-day morphology of the cliff and the occurrence of l i thodomous borings and marine deposits in the bottom of the cavity show that a large side aperture was opened when part of the cave was destroyed by the progressing wave-cut cliff. the lower part of the sequence testifies to a phase of deposition in transitional and shallow sea environment. this phase was correlated to some high stand of the isotopic stages 15-13, that in some places abraded the 2nd order terrace (di maggio et al. 1999). the upper part was deposited in continental environment and the lithological units embed vertebrate remains that can be ascribed to two different faunal assemblages. the lower ones yielded a fauna that can be referred to the elephas mnaidriensis faunal complex of sicily, of late middle pleistocene to early late pleistocene age (8(?)/6 – 5a isotopic stages). the upper ones embed an assemblage documenting a younger dispersal phase of mammals from the italian peninsula (pianetti – castello faunal complex of sicily). this assemblage is dominated by the savii ground vole, a species with steppe mediterranean affinities, that, in this context, testifies to a dry climate phase of the last glacial cycle (isotopic stage 4). the sedimentary sequence is closed by an anthropised level containing late mesolithic to early neolithic cultural remains (tusa personal communication), which can be referred to the pleistocene–holocene transition. 122 fig. 1 capo san vito peninsula: location of the sites and distribution of the marine terraces. the heights of the terrace edges are reported in the legend. penisola di san vito lo capo: ubicazione dei siti e distribuzione dei terrazzi marini. le altezze del margine interno dei terrazzi di vario ordine è riportata in legenda. a. cottignoli et al. 22..11.. ggeeoommeettrryy ooff tthhee sseeddiimmeennttaarryy bbooddiieess.. the shape of the lithological units in the k22 succession is controlled by two main factors: a) the shape of the karstic dissolution cavity where the sediments were deposited and b) the strong erosion activity which took place throughout the depositional history of the site. the lower units are sub-horizontal layers probably separated by paraconformities, that fill up the funnel – like bottom of the cave. the units of the upper half of the sequence (from the top of the ‘upper conglomerate’ upwards) are limited by erosion surfaces apparently dipping towards the south; these erosion surfaces are often channel-shaped and sometimes marked by stonelines. therefore, these units are sometimes shaped as channels whose axes plunge from the overlying abrasion surface to the bottom of the cavity. 22..22.. pprrooffiillee ddeessccrriippttiioonn the sequence is made up of the following units, from the bottom upwards. a. ‘base’ unit. coarse rounded calcareous sandstone with some fine gravel (5-20 mm) and common remains of marine molluscs. few pinkish to light orange clayey matrix; strongly cemented. thickness 0 to 20-40 cm depending on the shape of the underlying limestone surface. this units lies on the karstified limestone of the bottom of the cave and fills up part of the fractures. b. ‘lower conglomerate’ unit. polygenic conglomerate, with fine gravel to cobble-size subrounded elements with some rounded and subangular ones; unsorted; skeleton-supported structure. the conglomerate elements, mainly the less rounded ones, show sponge (clionia) borings. light pinkish matrix, made up of few angular or subangular quartz elements and very few subrounded flint; common dark reddish clayey aggregates, siltto medium sand-sized, impregnated of iron oxides; the skeleton of these aggregates is few, made up of coarse silt to very fine sand with quartz, few chert and sparse muscovite flakelets. fine micritic cement, with common larger euedral crystals. a second phase of cementation, deposed coarse subedral sparite crystals within the largest pores. thickness 0-35 cm; sharp, subhorizontal, slightly undulating limit. this unit lies within the funnel-like bottom of the cave and is shaped like a subhorizontal layer whose sides are limited by a roughly conical surface. common marine molluscs (spondylus, jujubinus) and few fish bone fragments c. ‘pinkish sandstone’ unit. light pinkish grainstone, strongly cemented, with common centimetre-size pores; few skeleton, made up of subrounded to subangular pebbles (maximum diameter 5 cm). most of the grains are apparently more or less fragmented bioclasts, possibly vegetal remains in which faint traces of cellular features can still be observed. very few angular very fine silt-sized quartz elements. common subrounded to rounded clayey aggregates, without skeleton, impregnated by amorphous fe-oxides; their size varies from very fine to fine sand. medium sorting. fine sandy matrix, made up of micrite elements. sparitic cement, made up of small size anhedral elements. thickness 15-20 cm; sharp, subhorizontal and slightly undulating limit. the unit is lens-shaped, convex downwards. common darker or lighter layer-like bands, caused by enrichments or depletions of iron oxides originated by movements of the water table. few fish bone fragments. (fig. 6 e). d. ‘upper conglomerate’ unit. polygenic conglomerate (biomicrites, biosparites, micrites and "scaglia"), with fine gravel to boulder-size elements (0.2 to 70-80 cm), fining upwards, skeletonsupported structure, common simple packing voids. strongly cemented. the elements are mainly prolate or oblate, subrounded, and their major axes usually lie horizontally, sometimes imbricated. very few matrix, made up of sparse very fine sand-size quartz elements and clayey aggregates as in c). these aggregates are common at the bottom and at 123 fig. 2 stratigraphic profile of the k22 sequence. 1: mesozoic coralgal limestone; 2: base unit; 3: lower conglomerate unit; 4: pinkish sandstone unit, 5: upper conglomerate unit; 6: orange unit; 7: red unit and petrocalcic horizon; 8: blocks unit; 9: brown unit. colonna stratigrafica della successione k22. 1: calcari coralgali mesozoici; 2: unità base; 3: unità conglomerato inferiore; 4: unità arenaria rosata; 5: unità conglomerato superiore; 6: unità arancio; 7: unità rosso e livello petrocalcico, 8: unità blocchi; 9: unità bruno. pedostratigraphic notes on ... the top of the layer and give it a pinkish colour. cement made up of micrite, finely layered in the pores, sometimes alternating with fe-oxides; a second phase of cementation deposed coarse subhedral sparite coatings within some pores. thickness 2-2.5 m; abrupt, subhorizontal, flat limit, gently dipping towards the centre of the cave. this unit covers the underlying unit c) and partly lies on the limestone bedrock of the northern side of the cave. its thickness increases towards the south, as the limit dips towards this direction. common remains of small size hippopothamus cf. pentlandi. e. ‘orange’ unit. reddish (2.5yr 4/6 red) silty loam to silty clay loam; well developed fine granular structure, slightly cemented. few skeleton, made up of sparse subrounded (dissolution) gravel-size elements (maximum diameter 3 cm). the sand-size fraction is made up of angular to subrounded quartz (very fine to fine sand), subrounded chert (slightly coarser) few muscovite flakelets (silt), angular to subangular fragments of biomicrites ad sparites (medium sand to fine gravel). common clayey aggregates (pedorelicts, sensu brewer, 1964) subrounded to rounded (fine to medium sand) stained by fe-oxides, usually without skeleton, sometimes with evident traces of very fine convolute layering, low birefringence strial b-fabric. (fig. 6 f). another group of aggregates contain less clay and feoxides and embed some fine skeleton with the same characteristics of that of the matrix. few clay coatings with iron oxides, some carbonate concretions. stipple speckled and granostriated bfabric. thickness 25-35 cm; sharp, flat limit, gently dipping towards the centre of the cave. this lens-shaped unit may be the eroded remain of a layer partly interfingered with the upper part of d); nevertheless, it can be observed only in a small area at the centre of the excavation profile, so that its stratigraphic position is not perfectly defined. common pulmonate molluscs, vertebrates and small mammals (crocidura aff. esuae, leithia ex gr. melitensis, maltamys aff. wiedincitensis). f. ‘red’ unit. red clay loam to silty clay loam, colour 2.5yr 4/6 red to 2.5yr 3/4 dark reddish brown, well developed medium polyhedric (prismatic in the upper part) structure. few subrounded (dissolution) skeleton. the sandy fraction is fine to very fine, mainly made up of angular to subrounded quartz (very fine to fine sand), common chert (slightly coarser), common muscovite laminae, few feldspar (some plagioclases, one sanidine), pyroxenes and some fragment of microcrystalline lava. few pedorelicts, slightly different from the matrix, but somewhat richer in clay and fe-oxides; rounded, fine to coarse sand-sized. common carbonate nodular concretions, nodules of iron and manganese oxides. few "dusty" clay coatings. striated, granostriated and stipple speckled b-fabric. (fig. 6 g h). thickness 50-110 cm; clear, flat limit, shaped as a large and deep depression, possibly an erosion channel. as a consequence of this erosion surface, the horizon lies upon units d) and e). in the western part of the excavation profile, a strongly cemented, 30-40 cm thick lens-shaped sublevel can be observed; it partly overlies a stone line of angular elements that marks the base of the "red" unit and embeds a large block, probably a cave ceiling or wall breakdown. the cementation is due to large anhedral sparite crystals, often organised in dendritic structures, rather dusty for fe-oxides impurities. common remains of continental gastropods, amphibians, reptiles, birds, large and small mammals. the mammal assemblage belongs the elephas mnaidriensis faunal complex of sicily and includes the following taxa: crocidura aff. esuae, leithia ex gr. melitensis, maltamys aff. wiedincitensis, hippopotamus cf. pentlandi and sus sp. g. ‘blocks’ unit. reddish silty loam, colour 2.5yr 4/6 red, medium developed polyhedric aggregation. common limestone skeleton, poorly sorted to unsorted (elements from 1 to 60-70 cm), made up of angular, prolate to oblate elements whose surfaces are altered by dissolution. skeleton supported or sometimes matrix supported structure. the sandy fraction is made up of angular to subangular quartz (very fine to fine sand with frequent rounded coarse sand elements); common muscovite flakelets, few feldspar and sparse pyroxene. common fragments of flint and of cherty rocks (scaglia), subangular to subrounded (medium to coarse sand); frequent slabs of sparitic limestone (very coarse sand to very fine gravel). common clayey pedorelicts, with very few fine skeleton, impregnated by fe-oxides. very common nodular concretions made up of sparite crystals, of various size. clayey groundmass, with very low birefringence; stipple speckled to granostriated b-fabric. thickness 40-60 cm; abrupt limit, marked by a stone-line, gently dipping towards the east and shaped as a large and shallow erosion channel. common remains of pulmonate gastropods and of micromammals. the small mammal assemblage, dominated by the vole microtus (terricola) ex gr. savii, also includes apodemus cf. sylvaticus and crocidura cf. sicula, while sus scrofa e cervus elaphus cf. siciliae occur among large mammals. this faunal assemblage can be referred to the pianetti–castello faunal complex. h. ‘brown’ unit. silty loam to sandy silt loam, colour 5yr 3/3 dark reddish brown, massive, rather loose. few limestone skeleton, unsorted (elements up to 50-60 cm), slightly altered by dissolution and chaotically dispersed. sandy fraction mainly made up of angular to subrounded quartz (very fine to medium sand), with some larger rounded elements; common fine muscovite flakelets, frequent feldspar and sparse pyroxene. common fragments of flint and cherty rocks (scaglia), subangular to subrounded (medium to coarse sand); few limestone slabs, sparse, very fine, rounded lava fragments. few clayey pedorelicts, embodying very few skeleton, impregnated by fe-oxides; common sparite concretions of various size; very common fine fragments and flakes of amorphous organic matter, at various degrees of decay. clayey groundmass, with low birefrin124 a. cottignoli et al. gence and stipple-speckled b-fabric. thickness 20-50 cm; clear, wavy limit, shaped as a shallow erosion channel. common more or less fragmented bone, charcoal, marine molluscs (patella, trochus) flint artefacts; remains of microvertebrates, (microtus (terricola) ex gr. savii, crocidura cf. sicula) and macrovertebrates (sus scrofa, vulpes vulpes e cervus elaphus). skeletal remains of homo sapiens. the typology of the lithic assemblage and the occurrence of obsidian artefacts show that these cultural remains can be ascribed to the late mesolithic-early neolithic (pleistocene-holocene boundary). 22..33.. ddiissccuussssiioonn the lowermost levels of the sequence, up to the top of the ‘pinkish sandstone’ unit, were deposited in peculiar environmental niches connected to near-shore or reef environments, like pools at the base of the reef or conglomerate deposition areas on abrasion surfaces. a more or less substantial input of terrigenous sediments coming from the neighbouring emerged areas characterises these deposits of transitional environment. the units ‘base’ and ‘lower conglomerate’ testify to high energy depositional events in shallow sea environment (intertidal or submerged beach), as shown also by borings of clyonid sponges occurring on pebbles of the ‘lower conglomerate’. conversely, the sandy unit ‘pinkish sandstone’ represents a very low energy environment, where almost only biogenic clasts, possibly fragments of algae or marine vascular plants, were deposited. it is likely that this rather homogeneous sediment was originated by in situ growth and decay of biogenic concretions, while middle or low energy transport processes were very rare. some weak input of sediments from the emerged land into these near-shore sediments is suggested by the occurrence of pedorelicts probably originated from the colluvium of soils developed on the abrasion surface overlying the cave. as these pedorelicts are mainly made up of clay and iron oxides, it may be inferred that they came from medium to long evolution red soils (alfisols or ultisols), that develop in temperate to warm–temperate climates and that are present in the capo s. vito area. the origin of unit ‘upper conglomerate’ is strongly questionable (di maggio et al., 1999). the large size of the cobbles and the low matrix content point to a high energy environment; conversely, the fossil remains of hippopotamus cf. pentlandi found in this unit are rather well preserved, and suggest therefore a low energy depositional environment, or at least a short range transport. river deposition may possibly explain the removal of the fine grained matrix by low energy flow; however, this hypothesis looks rather unlikely because no hydrographic basins or river sediments were found in the surrounding area. the general features of the deposit may also indicate a marine origin. the ‘upper conglomerate’ could be considered as a beach or a storm deposit, implying that the shoreline was rather close to the site. the terrigenous fine-grained fraction and the pedorelicts would have infiltrated into the pores of the conglomerate after the deposition of the coarse fraction. in this case the conglomerate, with its mammal fossil content, would date back to one of the high stand phases related to the isotopic stages 15-11, according to di maggio et al (1999). however, this range of ages is in contrast with several data concerning the presence of the hippo in the sicilian island, which is usually dated to the late middle pleistocene to late pleistocene (isotopic stages 8 or 6 ?). finally, an alternative explanation in accordance with all the available data, and based on the parsimony principle, would consider the ‘upper conglomerate’ as derived from a pre-existing conglomerate, dismantled by gravitational processes and runoff water, which would also have caused the transport of the vertebrate remains into the cavity. the upper part of the sequence, from the unit ‘orange’ upwards, was deposited in continental environment. the characteristics of the deposits follow the polycyclic nature of the "terra rossa" and result from the erosion of the soils and the accumulation of the products of their reworking into the cavity. the occurrence of pedorelicts in all these levels is sound evidence of erosion and transport (cremaschi, 1990b; boschian, 1998), and their concentration may be regarded as a rough estimate of the intensity of the reworking processes. the greater amount of pedorelicts in unit ‘orange’ documents a period when erosion was stronger than in the other phases. apparently, the pedorelicts found in the upper units are not so rich in clay and iron oxides as those in the underlying ones, and also embody some fine skeleton. it is likely that the older ones belonged to more evolved soils, while less developed soils overlied piana di sopra during the younger phase of the site formation process. as a consequence, it may be inferred that strong erosion processes had removed most of the soil cover of the area in some moment between isotopic stages 15-11 and 8-6. nevertheless, the occurrence of several gaps in the sequence suggests caution in inferring this diachronic and evolutionary hypothesis. summing up, the evolution of the climate towards ‘continental’ conditions may have started some deforestation and the triggering of erosive processes that caused the accumulation of unit ‘orange’. unit ‘red’ may be related to a phase of weaker erosive processes, with climate not so strongly continental as before. the occurrence of muscovite flakes all over the sequence shows that the aeolian input, still important nowadays, played always a consistent role in the formation of the "terra rossa" deposits. however, it must be pointed out that the palaeoclimatic meaning of this aeolian input is certainly different from that postulated for the northern regions of the italian peninsula (cremaschi, 1990a), even if it points towards somewhat aridic conditions. nevertheless, the occurrence of rounded coarse quartz grains within the upper units ‘blocks’ and ‘brown’ may testify to an increase of the aeolian transport, which probably corresponded to dune formation in the neighbours of the site and might suggest a shift of the climate towards dry conditions. eventually, the ‘brown’ anthropic level is characterised by a high content in fine amorphous organic matter consequent to human presence. 125pedostratigraphic notes on ... 33.. tthhee ""iissoolliiddddaa"" sseeqquueennccee this sequence (fig. 3) is located in the northernmost part of a widely extended set of deposits that occupy a morphostructural depression shaped in "scaglia"–like marly limestone of upper cretaceous to eocene age. it is limited to the north by the southern side of the calcareous plateau of piana di sopra, and to the south (at seno del bue marino) by a morphological high originated by the denudation of a limestone olistolith embedded in the scaglia. the profile studied here is about 50m long and 11m high, with its bottom at the height of the presentday sea-level. the base of the sequence is made up of late pleistocene shallow sea and intertidal deposits (di maggio et al., 1999), and lies on a marine abrasion surface located at 0.5-1m a. s. l., that partially cuts the eutyrrhenian terrace (vi order); this terrace is here 3-5m a. s. l. high, and is covered by sediments containing a warm, "senegal–like" marine invertebrate fauna including patella ferruginea and strombus bubonius (at seno del bue marino; ruggieri et al. 1968; mauz et al., 1997) (fig. 4, 5). as a consequence, the formation of the isolidda abrasion surface is younger than the eutyrrhenian, and can be reasonably referred to high stands related to the isotopic substages 5c or 5a ("neotyrrhenian"). six subhorizontal or slightly dipping units can be observed within the continental part of the sequence, and are hereafter described from the bottom upwards. 33..11.. pprrooffiillee ddeessccrriippttiioonn a. ‘marine’ unit it is made up of two sub-units. 1) biocalcarenite with some reddish sandy loam matrix. 2) conglomerate made up of coarse limestone and marly limestone blocks with lithodomous borings and cemented sandy matrix (sandstone) with pebbles; the pebbles are rather common in the lower part of this subunit and form a thin level at the very bottom. thickness about 1.3 m, sharp limit situated at about 0 m a. s. l. 126 fig. 3 schematic section of the isolidda sequence. sezione schematica della successione isolidda. fig. 4 geomorphological map of the isolidda area. 1: slope deposits; 2: weathered and eroded scarp; 3: inactive marine cliff (height > 10 m); 4: inactive marine cliff (height < 5 m), 5: active storm ridge; 6: neotyrrhenian marine deposits; 7: neotyrrhenian marine abrasion surface, 8: eutyrrhenian marine deposits; 9: eutyrrhenian marine abrasion surface, 10: marine abrasion surfaces (late early pleistocene – middle pleistocene). carta geomorfologica dell’area di isolidda. 1: deposito di versante; 2: scarpata di morfoselezione degradata; 3: falesia inattiva; 4: ripa di erosione marina inattiva; 5: cordone di tempesta attuale; 6: deposito marino neotirreniano; 7: superficie di abrasione marina neotirreniana; 8: deposito marino eutirreniano; 9: superficie di abrasione marina eutirreniana; 10: superfici di abrasione marina del tardo pleistocene inferiore – pleistocene medio. a. cottignoli et al. this unit was deposited in infralitoral environment and is at present partly covered by recent storm deposits. shells of spondylus sp., pectinidae and helicoidal gastropoda are present. b. ‘transitional’ unit sandy loam, 2,5yr 4/6 red with white carbonatic mottles, massive structure. sandy fraction made up of quartz and feldspar grains, muscovite and biotite laminae, common limestone and some flint slabs. channel and chamber microstructure. common nodules of iron oxides, micrite hypocoatings and infillings, iron-stained clay coatings on the pedorelicts and on the coarse grains. frequent pedorelicts, whose matrix is made up of subangular quartz, impregnated by fe-oxides and with poroand granostriated b-fabric. frequent mollusc shells. (fig. 6 c). stipple-speckled b-fabric. thickness 30 cm, sharp subhorizontal limit. c. ‘fine breccia’ (b1) unit breccia, made up of fine (up to 3 cm) subangular elements and reddish sandy matrix. thickness 25 cm; sharp, slightly wavy subhorizontal limit. d. ‘red with blocky levels’ unit the bottom part of this unit is dark red (2.5yr 3/6) sandy loam; medium developed fine granular structure. the sandy fraction is made up of quartz, flint and limestone (biomicrite and grainstone). common iron and manganese aggregates; frequent calcite concretions, mainly micrite infillings and hypocoatings covered by sparite coatings; coatings and hypocoatings made up of iron oxides. stipple-speckled and sometimes poroand granostriated b-fabric. the middle and upper part is red clay loam, with poorly developed polyhedric structure. sandy fraction made up of quartz, glauconite, feldspar and muscovite flakelets. common and thick coatings made up of iron oxides. (fig. 6 b). stipple-speckled and sometimes poroand granostriated b-fabric. the most outstanding characteristics are the almost thorough decalcification and the rubefaction of the clay fraction of the groundmass. thichness 4.7 m; sharp subhorizontal limit. several subhorizontal levels of large blocks are interlayered within this unit. common bioclasts, mainly remains of continental molluscs, strongly altered. e. ‘yellow–brown’ unit sandy loam, yellow 10yr 8/6, with medium gravel-size skeleton, poorly developed granular structure, common pores. sandy fraction made up of flint and quartz and some feldspar grains, muscovite laminae; limestone slabs are common. common diffuse and nodular calcite concretions; sequences of micrite coatings/hypocoatings, clay coatings and coatings of acicular calcite. (fig. 6 a). frequent typic and nucleic nodules of fe-oxides. few charcoal and vegetal remains. abundant rounded to subrounded pedorelicts. stipple-speckled b-fabric, sometimes crystallitic in the upper part, where the groundmass is impregnated by micrite. thickness 2.40 m; sharp, subhorizontal erosive limit. several thin breccia levels, with medium to fine gravel elements testify to phases of increase in detritic input; an erosion surface can be observed in the lower part. at the top of the unit there is a hard petrocalcic horizon, 20-30 cm thick, with common shells of continental molluscs. common fragments of continental mollusc shells. f. ‘red–brown’ unit sandy loam with few subangular limestone and cherty slabs, reddish brown 2.5yr 4/4, poorly developed granular structure. the sandy fraction is made up of rounded quartz grains, feldspar, muscovite laminae and some glauconite grains. micrite and sparite coatings, (fig. 6 d), few coprolites; pedorelicts with quartz skeleton and few iron oxides; common nodules of fe-oxides. stipple speckled bfabric, sometimes poroor granostriated; in some areas the groundmass is impregnated by micrite. 127 fig. 5 panoramic view of the isolidda area. eu: eutyrrhenian abrasion surface; neo: neotyrrhenian abrasion surface; is.5: isolidda sequence. panoramica dell’area di isolidda. eu: superficie di abrasione eutirreniana; neo: superficie di abrasione neotirrreniana; is.5: successione isolidda. pedostratigraphic notes on ... 128 fig. 6 microphotographs of the thin sections. a) clay and micrite coatings on pedorelicts and limestone grains; xpl. b) sparite coatings and iron oxide coatings and ipocoatings on grains and simple voids. xpl. c) pedorelicts and marine mollusc shells. xpl. d) sparite capping on rounded quartz grain. xpl. e) calcareous bioclasts, embedded in microsparite/micrite groundmass; at left, an elongated fish bone remain. ppl, frame width 1100 mm. f) rounded pedorelict made up of clay and iron oxides and, with stipple speckled b-fabric. clayey groundmass, with fine sand to silt-size quartz grains. xpl, frame width 1100 mm. g) fragments of layered dusty clay coatings, embedded in sandy silt loam groundmass with fe-oxides. ppl, frame width 1100 mm. h) as before, xpl. microfotografie delle sezioni sottili. a) pedorelitti e clasti carbonatici con rivestimenti argillosi e micritici; xpl. b) rivestimenti di ossidi di ferro e sparite su clasti e pori; xpl. c) pedoreliti e resti di molluschi marini; xpl. d) rivestimento sparitico “a cappello” su clasto di quarzo arrotondato; xpl. e) bioclasti calcarei in matrice microsparitica/micritica; a destra, un frammento allungato di osso di pesce; ppl, larghezza dell’immagine 1100 mm. f) pedorelitto argilloso e con ossidi di ferro, b-fabric macchiettata. pasta di fondo argillosa, con granuli di quarzo delle dimensioni delle sabbie fini-limo. ppl, larghezza dell’immagine 100 mm. g) frammenti di rivestimenti argillosi impuri stratificati; pasta di fondo franco limosa con sabbia ed ossidi di ferro. ppl, larghezza dell’immagine 1100 mm. h) come sopra, xpl. a. cottignoli et al. thichness 1 m, sharp, subhorizontal limit. at the bottom, a thin blocky level can be observed. the top part of the unit is strongly cemented and covered by a pinkish calcite crust. g. ‘breccia’ (b2) medium to fine breccia (3-5 cm), made up of limestone and cherty elements, well sorted; few sandy loam reddish brown matrix, poorly cemented. thickness 0.7-1.5 m, abrupted limit. the top of the unit is reddish brown sandy loam with 12 to 15 cm cobbles, forming a continuous, about 50 cm thick horizon that covers the sequence. frequent fragments of shells of continental molluscs. 33..22.. ddiissccuussssiioonn as indicated by its field aspect and micromorphological characteristics, isolidda can be interpreted as a cyclic sequence of palaeosols developed on scree-slope deposits located in a morphological trap; different pedo–climatic conditions affected the formation of the units. the lowermost horizon of the sequence, i. e. the biocalcarenitic ‘marine’ unit, is covered by beach deposits representing the transition to fully emerged conditions (‘transitional’ unit ); soil forming processes affected the ‘transitional’ unit probably during a temperate climate phase, as shown by its colour, texture and pedofeatures that suggest the development of an illuviation horizon. the thin layer of angular pebbles (b1) overlying this unit may be interpreted as the effect of a cold climatic fluctuation, that caused the accumulation of coarse deposits and interrupted abruptly the soil forming processes. the following unit (‘red with block levels’) probably testifies to two climatic phases. during the first one, some climatic instability induced variously alternating deposition, soil-forming and erosion processes that built up a rhythmic interlayering of "stone lines" of cobbles and blocks with slightly pedogenised finer deposits. during the second phase, long lasting soil-forming processes acted on the stable surface of this deposit under temperate-wet pedoclimatic conditions. a red soil (now palaeosol) developed, affecting the whole unit. the unit (‘yellow–brown’) is divided from the underlying ‘red with block levels’ by a sharp erosional limit, and a secondary erosion surface can be observed within it. the overall aspect of this unit, in which some levels of chaotically arranged breccia are evident, points to a fast colluvium process that involved sediments coming from a landslide body located to the west of the outcrop. this hypothesis is corroborated by the occurrence of frequent pedorelicts and coarse coatings within this unit, as well as by the scanty evidence of soil forming processes. these processes are evidence of a renewed climatic instability phase, during which arid events characterised by high evapotranspiration rate caused the deposition of carbonatic concretions, culminating with the formation of a petrocalcic horizon at the top of the unit. this unit indicates a remarkable change in sedimentary and pedogenetic conditions with respect to the underlying units. within the third unit (‘red–brown’), the decalcification of detrital fraction and rubefaction of clays are weak, while a greater amount in rounded quartz grains indicates an increased aeolian input. pedofeatures like iron concretions are well developed and pedorelicts are common, showing that some weak soil forming processes and colluvium acted under probably temperate-cold conditions. the breccia levels, indicated as b1 and b2, located close to the bottom and to the top of the sequence, can be compared to the éboulis ordonnés resulting from strong physical weathering of rocks due to abrupt dry–cold climatic variations that have been reported in the late glacial sequences of north western sicily by agnesi (1989) and ulzega (1989). 44.. ccoonncclluussiioonnss in the north–western sector of the capo san vito peninsula, the formation of sequences of continental deposits, soils and palaeosols has been controlled by several interacting factors during the quaternary. the major role was played by the quaternary climatic fluctuations and related eustatic sea-level changes; the tectonic movements modulated role and intensity of the morphogenesis, thus affecting the development of the marine terraces and of the soils. as a consequence, soil evolution is typically polycyclic in this context. the resulting sediments and soils are characterised either by features that indicate climatic (and tectonic?) stability, or by colluvial and detrital components and by erosion surfaces that point to a highly dynamical environment. such an instability characterised mainly the climatic deterioration phases; in this southern area, the most relevant aspect of the climate cannot have been a "strong" decrease in temperature, as it was at higher latitude, but probably some sort of shift to continental characteristics of the environment. the isolidda sequence is the record of this evolution through the last ice age. the ‘marine’ unit at the base of the sequence covers the abrasion surface of the vii order terrace, which is of neotyrrhenian age (stage 5c/5a?), and was deposited during the last marine transgression, before the beginning of the first pleniglacial (stage 4). the beach deposit of the ‘transitional’ unit represents the ultimate emersion of the area; soil-forming processes acted on its top, apparently under temperate conditions, until a cool–dry event documented by the éboulis ordonnés (breccia level b1) interrupted the process. the thick deposit ‘red with blocky levels’ is the result of probably fast accumulation of fine sediments with coarse debris events, in a landscape with scant vegetal cover. strong pedogenesis acted on this deposit during a subsequent long-lasting temperate-humid climatic phase (stage 3?), favouring the formation of a poorly developed alfisol. a marked climatic deterioration originated the unit ‘yellow–brown’: fast erosive and depositional events alternated to weak soil-forming point to highly dynamic and unstable conditions, probably characterised by scant forest cover and contrasted seasons. later, the climate evolved towards cold–temperate conditions that favoured a weak pedogenesis, as documented by the unit ‘red-brown’, which is somewhat rubefacted (stage 2?). the gravelly levels (b2) at the top of the sequence 129pedostratigraphic notes on ... may be representative of late second pleniglacial–late glacial "cold" climatic phases, when éboulis ordonnélike deposits accumulated (stage 2-1?). traces of older soils are preserved on a wide relict of the i order terrace, which has been an isolated relief since its emersion. these relicts are mainly preserved within sequences deposited in caves, depressions and notches, like the site k22. here, they occur in the basal marine and transitional units of the sequence (‘base’, ‘lower conglomerate’, ‘pinkish sandstone’), and can be correlated to the isotopic stages 15-13. a drift towards a "continental" climate, which is supposed to have caused deforestation and the onset of erosive processes, would be indicated by the unit ‘orange’. the formation of this unit likely followed a long lasting phase of stable environmental conditions: the occurrence of abundant fragments of thick clay coatings (papulae sensu brewer, 1964), indicates that evolved soils (alfisols or ultisols, typical of long "interglacial" phases of temperate conditions) originated these pedorelicts. tentative correlations can ascribe the soil-forming phase to stage 7, while the following erosive phase may be related to glacial stage 6. the unit ‘red’ may have been formed during a period of climatic improvement, when the erosion was somewhat weaker; possibly an interglacial phase that can be tentatively correlated to the last interglacial (isotopic stage 5 s. l.). the occurrence of muscovite flakes throughout the sequence shows that the aeolian input played a consistent role in the formation of the deposits. nevertheless, the occurrence of rounded coarse-grained quartz within the upper units ‘blocks’ and ‘brown’ may point to an increase of the aeolian transport, which likely corresponded to dune formation in the neighbours of the site (agnesi et al. 1998; di maggio et al. 1999). a climatic shift towards dry conditions during stadial phases of the last glacial cycle may explain this phenomenon. these units are here tentatively correlated to the stages 3 or 2 (‘blocks’) and to the pleistocene-holocene transition (‘brown’). finally, it must be pointed out that the sequences are located on morphological highs or in other areas of strong morphogenetic energy, where stratigraphic gaps can develop easily. this peculiarity explains the shortness of the sequences, but also infers some incertitude in the interpretation. rreeffeerreenncceess agnesi v., 1989. levanzo. in "guida alle escursioni", gruppo nazionale geografia e geomorfologia, cnr, trapani 27 – 30 giugno 1989, 27 –32. agnesi v., macaluso t., masini f., 1998. l’ambiente e il clima della sicilia nell’ultimo milione di anni, in s. tusa (ed.) "prima sicilia, alle origini della società siciliana", vol. i, 31-52, ediprint, palermo. boschian g. (1998). middle pleistocene to early holocene infilling deposits of the trieste karst caves (north-east italy). xiii uispp congress, forlì (italy), september 8-14, 1996, vol. 1, section 3-paleoecology, subsection geoarchaeology, 383-386. brewer r., 1964. fabric and mineral analysis of soils. john wiley and sons, new york. bullock p., fedoroff n., jongerius a., stoops g., tursina t., babel u., 1985. handbook for soil thin section description, waine research publications, wolvehampton. catt j. a., (ed.), 1991. paleopedology manual. quaternary international, 6, 1-95. cremaschi m., 1990a. the loess in central and northern italy: a loess basin between the alps and the mediterranean region. in cremaschi m. (ed.) "the loess in central and northern italy: a loess basin between the alps and the mediterranean region", c.n.r., centro di studio per la stratigrafia e la petrografia delle alpi centrali. quaderni di geodinamica alpina e quaternaria, 1, 15-19. cremaschi m. (1990b). depositional and post-depositional processes in rock shelters of northern italy during the late pleistocene: their paleoclimatic and paleoenvironmental signif icance. quaternaire, 1990 (1), 51-64. di maggio c., incandela a., masini f., petruso d., renda p., simonelli c., boschian g., 1999. oscillazioni eustatiche, biocronologia dei depositi continentali quaternari e neotettonica della sicilia nord-occidentale (penisola di san vito lo capo trapani). il quaternario, 12 (1), 25-49. mauz b., buccheri g., zöller l. & greco a., 1997 middle to upper pleistocene morphostructural evolution of the nw coast of sicily: thermoluminescence dating and palaentological-stratigraphical evaluations of l i t toral deposits. palaeogeography, palaeoclimatology, palaeoecology, 128, 269-285. orombelli g., 1971, concetti stratigrafici utilizzabili nello studio dei depositi quaternari continentali, riv. ital. paleontologia stratigrafia, 77 (2), 265-291. ruggieri g., buccheri g., rendina m., 1968 – segnalazione di tirreniano fossilifero a trapani. riv. min. sic., 112 114, 1 4. sanesi g., 1977, guida alla descrizione del suolo. c.n.r., p. f. conservazione del suolo, pubbl. n° 11, firenze. ulzega a., 1989, san vito lo capo – piana di sopra macari, in guida alle escursioni, gruppo nazionale geografia e geomorfologia, cnr, trapani 27 – 30 giugno, 18 – 23. 130 ms. ricevuto marzo 2002 ms. received: march 2002 a. cottignoli et al. misure del solco tirreniano (mis 5.5) nell’isola di capri: valutazione di attività tettonica durante il pleistocene superiore luigi ferranti1 & fabrizio antonioli2 1dipartimento di scienze della terra, università federico ii, largo san marcellino 10, 80138 napoli 2enea, casaccia, roma riassunto: l. ferranti & f. antonioli, misure del solco tirreniano (mis 5.5) nell’isola di capri: valutazione di attività tettonica durante il pleistocene superiore (it issn 0394-3356, 2007). l’isola di capri è ritenuta tettonicamente stabile nel pleistocene superiore in base alla presenza lungo la fascia costiera del solco tidale dell’ultimo interglaciale (124 ka bp) ad un’altezza all’incirca coincidente con quella eustatica (6±3 m sul livello del mare attuale). misure di dettaglio della sua altezza, qui presentate, dimostrano una variabilità tra 5.2 e 8.0 m, con quote più elevate nel settore se dell’isola, dal quale decrescono progressivamente verso n e verso w fino ad un minimo nel settore nw. tale andamento è attribuito a piccole dislocazioni tettoniche lungo alcune faglie riportate nella cartografia ufficiale. la polarità della dislocazione risulta consistente con la distribuzione regionale della subsidenza nei golfi di napoli e salerno (parte della fascia dei bacini peri-tirrenici), dove nel quaternario è prevalsa un estensione ad asse ~nw-se. i tassi di dislocazione verticale mediati nel pleistocene superiore per le faglie ipotizzate a capri sono estremamente bassi (intorno a 0.01 mm/a, un ordine di grandezza in meno rispetto alle faglie sismogenetiche presenti in asse alla catena appenninica). ciò suggerisce movimenti di tipo asismico o micro-sismico, controllati da discontinuità meccaniche a profondità crostali ereditate dalla precedente tettonica a thrust, oppure formatesi durante l’estensione che ha controllato l’apertura dei bacini peri-tirrenici abstract: l. ferranti & f. antonioli, subtle tectonic displacements and active structural blocks in the last 124 ka bp revealed by measurements of the mis 5.5 tidal notch, capri island, southern italy (it issn 0394-3356, 2007). capri island, located on the western side of southern italy, central mediterranean sea, is considered tectonically stable during the late pleistocene based on the nearly eustatic (6±3 m a.s.l) elevation, along its rocky coastline, of the tidal notch attributed to the last interglacial and dated at 124 ka. in this study, we present detailed (cm-scale) measurements of the notch elvation, which ranges between 5.2 and 8.0 m a.s.l. the change in elevation of the notch is not random, but rather decreases progressively from a southeastern high sector along the westen and southern coasts to reach a minimum in the north-western sector. we argue these changes in elevations are caused by minor tectonic slips along previously mapped faults. the pattern of down-dropping of the tidal notch is consistent with the active subsidence occurring in the gulf of naples and salerno, located north and south of capri island, respectively. within these basins, which are part of a belt of basins flooring the continental shelf of the western, tyrrhenian flank of italy (perityrrhenian basins), the largest subsidence was controlled by a ~nw-se extension during pliocene-quaternary. the nw-se extension is also active today along with a ~ne-sw directed extension, that characterizes the main seismogenic belt of the apennines mountains further east, as documented by seismicity, bore-hole breakouts and active fault studies. the very-low vertical displacement rates (~0.01 mm/a) averaged over the late pleistocene of the faults inferred at capri, which are an order of magnitude lower than the displacement rates of the main seismogenic faults of the apennines, suggest asesimic or microseismic, slow motion. fault slips may be controlled by deep mechanical surfaces which were either inherited by the pre-late tertiary thrust imbrication, or formed during pliocene-quaternary extensional development of the peri-tyrrhenian basins.. parole chiave: solco tidale, mis 5.5, variazioni in elevazione, faglie attive, isola di capri, italia meridionale. keywords: tidal notch, mis 5.5, elevation changes, active faults, capri island, southern italy. il quaternario italian journal of quaternary sciences 20(2), 2007 125-136 1. introduzione il margine tirrenico campano è caratterizzato da una alternanza di piane e promontori, le prime in subsidenza e i secondi ritenuti sostanzialmente stabili a partire dal tardo pleistocene medio-pleistocene superiore (brancaccio et al., 1991; mariani & prato, 1992; romano, 1992; cinque et al., 1993; ferranti et al., 2006). la subsidenza delle piane costiere e della loro prosecuzione in mare viene attribuita principalmente all’attività di faglie normali a direzione ne-sw, con asse di dislocazione orientato nw-se parallelo al margine (fig.1; mariani & prato, 1992; ferranti et al., 2006; milia et al., 2003). queste faglie sono inserite nel più generale contesto della tettonica distensiva che ha interessato il margine occidentale appenninico nel pliocenequaternario, ribassandolo verso il mar tirreno a sw (ferranti & oldow, 2005; caiazzo et al., 2006), ma che localmente ha formato delle depressioni costiere o marine ortogonali al margine (bacini peri-tirrenici; mariani & prato, 1992; bruno et al., 2000). le faglie orientate ne-sw che bordano le depressioni marginali sono state attive principalmente nel pleistocene inferiore (caiazzo et al., 2006) e medio (gars & lippman, 1984; milia et al., 2003); nondimeno, la loro attività nel pleistocene superiore ed olocene è documentabile sulla base di profili sismici (mariani & prato, 1992; bruno et al., 2000). attualmente, le principali faglie attive e sismogenetiche in italia meridionale sono localizzate più ad e, lungo l’asse della catena appenninica, dove hanno direzione nw-se e la dislocazione avviene lungo un asse di estensione regionale orientato ~ne-sw (fig.1; valensise & pantosti, 2001; maschio et al., 2005; ferranti et al., 2008). lungo il margine, tuttavia, l’attuale deformazione avviene lungo assi orientati sia ~ne-sw che ~nnw-sse, come indi126 l. ferranti & f. antonioli cato da break-out in pozzo e localmente da studi di sismicità (fig.1; amato & montone, 1997; milano et al., 2004), il che lascia presupporre la coeva attività dei due sistemi di faglie. a differenza che nei bacini peri-tirrenici, l’attività delle faglie ne-sw non sarebbe stata risentita in maniera apprezzabile nei promontori. difatti gli studi geomorfologici condotti nei promontori documentano movimenti verticali pliocenico-quaternari dell’ordine di centinaia di metri, ma sostanziale stabilità a partire dal tardo pleistocene medio (brancaccio et al., 1991; romano, 1992; barattolo et al., 1992; caiazzo et al., 2006). il comportamento differenziale tra bacini e promontori nel pleistocene superiore viene ben documentato a livello regionale dalla variabile altezza di elementi geomorfologici relitti dell’ultimo interglaciale, o tirreniano, il cui picco viene datato a 124 ka bp e corrisponde al mis 5.5 della curva isotopica dell’ossigeno (waelbroeck et al., 2002), con livello eustatico a 6±3 m rispetto all’altezza del mare attuale nel mediterraneo (ferranti et al., 2006). un profilo regionale dell’altezza del marker tirreniano, orientato parallelo alla costa del margine campano, mostra una marcata subsidenza attraverso le piane del volturno, del golfo di napoli e di salerno, ed una quota prossima a quella eustatica negli alti morfo-strutturali interposti, il che riflette la struttura crostale ipotizzata per questo margine continentale (fig.1). in questo contesto, anche l’isola di capri, prosecuzione della dorsale della penisola sorrentina a cavallo dei golfi di napoli e salerno (fig.1), viene considerata stabile dal punto di vista tettonico a partire dal tardo pleistocene medio, come documentato dall’altezza quasieustatica del solco tidale attribuito all’ultimo interglaciale (brancaccio et al ., 1991; romano, 1992). il solco affiora in diversi punti lungo la fascia costiera ad un’altezza complessivamente simile a quella raggiunta dal mare 124 ka bp, e ‘sigilla’ il perimetro e la topografia attuali dell’isola. pertanto, a partire dall’ultimo interglaciale, capri sarebbe stata immobile e senza movimenti differenziali tra le sue parti. il rilevamento di questo antico solco, dato il profilo accidentato delle coste capresi, è stato effettuato sinora attraverso stime, condotte da distanze più o meno ravvicinate, e solo raramente attraverso una misura diretta e rigorosa. recentemente, la comunità scientifica ha cominciato a porre attenzione anche ai movimenti minimi, che possono fornire indicazioni sulle deformazioni recenti (e.g. antonioli et al., 2006b; ferranti et al., 2007). questi movimenti possono essere ricostruiti grazie ad oggetti geologici relativamente giovani, quale il solco in oggetto, e pertanto risulta di fondamentale importanza una misura precisa delle altezze. misure dettagliate del solco tirreniano da noi effettuate su tutto il perimetro costiero di capri, per circa 18 km, hanno permesso di verificare con precisiofig. 1 carta tettonica del margine tirrenico campano (in basso) e profilo parallelo alla costa delle altezze s.l.m. del marker tirreniano (in alto, modificato da ferranti & alii, 2006). assi di strain in pozzo da amato & montone (1997); assi di strain da analisi cinematica delle faglie da milano & alii (2004); assi di strain sismici da: a) catalogo harvard cmt (http://www.seismology.harvard.edu/cmtsearch.html), frecce bianche; b) milano & alii (2004), frecce nere. faglie da ferranti & alii (2008), modificato; e milia & alii (2003). tectonic map of the tyrrhenian sea margin of campania (below) and coast-parallel profile of the elevation (in m a.s.l) of the tyrrhenian marker (above; from ferranti & alii, 2006). borehole break-out axes after amato & montone (1997); strain axes from fault-kinematic analysis after milano & alii (2004); seismic strain axes after: a) harvard cmt catalogue (http://www.seismology.harvard.edu/cmtsearch.html), white arrow; b) milano & alii (2004), black arrow. faults after ferranti & alii (2008), modified, and milia & alii (2003). ne la sua altezza e determinarne la benché minima variabilità laterale. nel presente contributo si descrive la distribuzione e l’altezza del solco tirreniano lungo la fascia costiera dell’isola, che fornisce interessanti indicazioni su movimenti occorsi a capri nel pleistocene superiore. il pattern di variazione in altezza, che presenta andamenti non casuali permette, alla luce dell’assetto geologico-strutturale dell’isola, di formulare ipotesi circa l’origine di questi movimenti, con esclusione di fenomeni relativamente superficiali e la possibile esistenza di strutture tettoniche ancora attive. inquadrati in un contesto più generale, i nuovi dati permettono di inserire i movimenti riscontrati all’isola di capri nel più vasto contesto cinematico del margine costiero della campania, dove più ingenti movimenti tettonici e vulcano-tettonici sono testimoniati nella storia geologica recente e attuale, e di ipotizzare in via preliminare quali modelli deformativi possano spiegare i piccoli movimenti osservati. 127misure del solco tirreniano ... 2. assetto geologico-strutturale l’isola di capri è formata da carbonati mesozoici e cenozoici in facies di margine e scarpata di piattaforma, e di transizione a bacino (barattolo & pugliese, 1987; d’argenio et al., 2004), seguiti stratigraficamente da minori spessori di sedimenti terrigeni del miocene medio (castelluccio & napolitano, 1989), e da depositi marini e continentali quaternari (barattolo et al., 1992). l’assetto strutturale dell’isola è caratterizzato dalla presenza di due scaglie tettoniche sovrapposte, secondo un movimento orizzontale all’incirca da s verso n, lungo un piano a basso angolo ben visibile ai piedi della scarpata che delimita a e il settore di anacapri fino a punta sbruffo, e a punta del capo all’apice ne dell’isola (fig. 2a). mentre nella scaglia superiore affiorano calcari massicci, quella inferiore è costituita da litotipi argilloso-arenacei del miocene, e, a punta sbruffo, da calcari a noduli di selce dell’oligocene (fig. fig. 2 a) carta geologica; e b) sezione geologica schematica dell’isola di capri (ridisegnate e lievemente modificate da: barattolo & alii, 1992; faglie, giaciture strati e isobate da d’argenio & alii, 2004). le linee continue indicano faglie certe, quelle tratteggiate faglie presunte. generalized a) geolgical map, and b) profile of capri island (modified after barattolo & alii, 1992; faults [dashed where inferred], bedding and isobaths after d’argenio & alii, 2004). 2a) 2b) 128 2a). con tutta probabilità, come osservato nella contigua penisola sorrentina, i terreni oligo-miocenici restano a loro volta sopra altri carbonati, non presenti in affioramento. questa struttura, formatasi durante le fasi di compressione del miocene che hanno portato più in generale alla formazione della catena appenninica (patacca et al., 1990), è stata ritagliata da faglie trascorrenti destre e sinistre, orientate circa e-w, le prime, e ne-sw, le seconde (fig. 2a; castelluccio & napolitano, 1989), collegate al sistema di faglie attualmente sommerse la cui attività ha determinato le attuali dimensioni dell’isola. in particolare, le faglie ad andamento ne-sw (antiappenninico) sembrano aver avuto un ruolo più importante rispetto a quelle e-w, e hanno condotto al ribassamento della parte orientale (blocco di capri) rispetto a quella occidentale (blocco di anacapri) di circa 500 m, come misurato dalla dislocazione della superficie di sovrascorrimento miocenico (fig. 2b). dunque, le faglie trascorrenti in questione posseggono anche una significativa componente di movimento verticale. queste faglie controllano anche l’andamento della linea di costa (fig. 2a), che presenta numerosi tratti ad orientazione e-w (in particolare sui lati s e n dell’isola), ne-sw (lato orientale e settore occidentale della baia di marina piccola) e n-s (versante occidentale di capri). numerosi lembi di terrazzi marini quaternari, attualmente sollevati, hanno permesso di scandire le diverse tappe della crescita del rilievo durante il pleistocene inferiore e medio, con alternanza di fasi di spianamento (durante le quali si modellavano dei terrazzi e avveniva il sollevamento in blocco dell’isola) e fasi tettoniche che hanno sbloccato i terrazzi precedentemente formatisi, attualmente distribuiti tra i 300 e i 20 m s.l.m. (barattolo et al., 1992). in generale, il sollevamento di lungo termine (ultimi 2 ma circa) di capri è avvenuto in maniera coerente con il margine occidentale della campania ad un tasso medio di 0.26 mm/a (ferranti & oldow, 2005), e si è accompagnato all’azione di faglie normali che hanno ribassato i settori periferici. successivamente all’ultima fase tettonica che sagoma definitivamente il perimetro costiero di capri, si ha la formazione di solchi e piccole piattaforme di abrasione, talora associate a puddinghe marine, poste sotto i 10 m di quota alla base delle falesie lungo l’intero perimetro dell’isola. in particolare, il solco di 124 ka bp, in base alla correlazione con un solco posto alla stessa quota in penisola sorrentina e datato con metodi radiometrici (brancaccio et al., 1978), è posto ad una altezza stimata di 8 m (barattolo et al., 1992). misure dettagliate del solco tirreniano in prossimità delle grotte costiere sono riportate nella monografia di kyrle (194647), dedicata allo studio delle grotte dell’isola di capri. mancano però nel pregevole lavoro di kyrle misure effettuate lungo le falesie. l’affioramento di un solco a quote più basse (+ 1.5 m s.l.m.) nel settore orientale di capri è stato attribuito ad un episodio minore all’interno dell’ultimo interglaciale (cinque et al., 1986). attualmente, capri rimane fuori dal settore di grandi movimenti verticali di natura vulcano-tettonica che contraddistinguono il settore centro-settentrionale del golfo di napoli (scandone et al., 1991; milia et al., 2003), e viene considerata tettonicamente stabile (brancaccio et al., 1991; romano, 1992). 3. l’altezza del solco tirreniano 3.1 metodologia nel giugno 2003 sono stati misurate in dettaglio le altezze del solco e della piattaforma di abrasione tirreniani lungo tutto il perimetro costiero dell’isola (fig. 3). il fig. 3 carta dell’altezza (corretta per la marea) del solco e del margine interno della piattaforma tirreniani. map of the tide-corrected elevation of the tyrrhenian notch and platform inner margin. l. ferranti & f. antonioli 129 punto effettivo di misura è rappresentato dalla massima concavità, nel caso del solco, e dal margine interno (la linea di intersezione tra la piattaforma e la paleo-falesia retrostante) nel caso della piattaforma, in quanto questi elementi morfologici meglio approssimano il livello del mare contemporaneo alla loro formazione. in particolare il solco offre la massima accuratezza nella determinazione del paleo-livello del mare (±5 cm) rispetto alla piattaforma abrasiva, per la quale una correzione difficilmente calcolabile (stimabile in 0.5-1 m), sempre positiva, è necessaria per risalire all’antico livello marino (ferranti et al., 2006). le altezze sono state misurate usando una rotella metrica riferita al livello del mare osservato al momento della misura. a causa della ripidezza delle falesie costiere di capri, le misure sono state effettuate con tecniche alpinistiche (e. g. fig. 4c; 4e), il che spiega la mancanza di misure dirette finora esistenti in letteratura. un errore di misura di circa 10 cm è stato assunto, ripetendo le misure in maniera sequenziale nello stesso sito, per tener conto di un posizionamento impreciso della rotella e una cattiva identificazione del punto di concavità. per i siti dove la misura è risultata più difficile, è stata adottata un’incertezza più conservativa variabile da 20 a 30 cm (tab. 1). per ogni misura è stata annotato il momento (approssimato all’ora), e le misure sono state corrette per le variazioni mareali, usando le altezze prossime all’orario di misura stipulate ogni ora dai mareografi di napoli e salerno (http://www.idromare.com/reti_rmn_cenni.php). poiché le misure sono state effettuate in un periodo di alta pressione stabile, la correzioni per le fluttuazioni di pressione barometrica determinate dai medesimi mareografi sono risultate <1 cm. le nostre misure sono state integrate con le determinazioni effettuate da kyrle (1946-47). le grotte rappresentano un ambiente conservativo nei confronti dell’erosione, e dunque hanno un elevato potenziale di preservazione delle evidenze morfologiche quali il solco. kyrle riporta spesso l’altezza di questo solco, approssimata al decimetro. poiché l’incertezza nella misura non è nota, né è possibile effettuare correzioni mareali e barometriche alle misure di kyrle, è stato adottato un errore cumulativo di ±20 cm a tali misure, che tiene conto dell’escursione massima di marea e di un errore di misura doppio rispetto al nostro, al quale va sommata l’incertezza propria dell’indicatore di paleo-livello marino (tab. 1). in molte località in italia, inclusa anche l’isola di capri, si osserva sotto il solco tirreniano, la cui base è marcata da una piccola mensola orizzontale, una superficie concava con più ampio raggio di curvatura rispetto al solco soprastante, quasi fosse un solco slabbrato e profondamente addolcito, e mancante di mensola alla base. tale morfologia di “doppio solco” è stata tipicamente attribuita all’abrasione prodotta dal mare nella fascia immediatamente sottostante il pelo d’acqua durante limitate oscillazioni del livello marino nel picco eustatico tirreniano. recenti ricerche (antonioli & alii, 2006a), sono giunte alla conclusione che questa forma fig. 4 alcuni esempi del solco tirreniano a capri: a) scoglio ricotta; b) cala articola, panoramica; c) cala articola, durante le operazioni di misura; d) matermania, con la piattaforma associata; e) a ‘vascio funno. outcrops of the tyrrhenian notch at capri: a) scoglio ricotta; b) cala articola, general view; c) cala articola, detail of the mesurements; d) matermania, note the platform related to the notch; e) a ‘vascio funno. misure del solco tirreniano ... 130 può essersi sviluppata nelle prime fasi di uno stazionamento interglaciale, e che l’accresciuto carico d’acqua sulla piattaforma costiera ne abbia provocato la successiva subsidenza isostatica e l’allargamento e l’addolcimento della forma, venendosi poi a formare il solco di massimo stazionamento nella fascia costiera immediatamente sovrastante. nel seguito, si farà riferimento al solco tidale di massimo stazionamento ovvero tirreniano s.s. sensu antonioli et al., (2006a), cioè il solco più alto misurato. 3.2 risultati la distribuzione delle altezze misurate del solco e dalla piattaforma lungo la costa caprese è mostrata in fig. 3 e elencata in tab. 1. di seguito vengono descritte le situazioni più interessanti di affioramento effettuando il periplo in senso antiorario e partendo dall’estremità ne dell’isola. l’altezza riportata del solco viene riferita a quella della sua massima concavità, già scremata della correzione mareale e, per brevità, senza l’errore stimato (stipulato in tab. 1). lungo la costa settentrionale e occidentale di capri, il solco tirreniano non è ben preservato, probabilmente in ragione del fatto che questi settori risultano molto esposti agli agenti erosivi che hanno distrutto la maggior parte della morfologia in questione. al contrario, il solco sui lati meridionale ed orientale dell’isola risulta molto meglio preservato. benché affacciata verso n verso il golfo di napoli, più chiuso rispetto a quello di salerno che la limita a s, capri risulta esposta ai forti venti di maestrale e settentrione e ciò potrebbe offrire una spiegazione plausibile alla osservata preservazione differenziale tra lato s e n dell’isola. un altro motivo della differenza tra i due settori potrebbe risiedere in una originario sviluppo non uniforme del solco. difatti solo nel settore meridionale dell’isola (incluse le coste sw e se) il solco viene osservato nella sua compiutezza (forma ben sviluppata, mensola, tab. 1 altezza del solco tirreniano nell’isola di capri (in metri s.l.m.) ...... sito settore altezza ora misura correzione incertezza altezza ref. misurata (aa/mm/gg/hh) mareale dato corretta (*) scoglio ricotta n 7.10±0.10 03/6/21/15 -0.14 ±0.05 6.96±0.15 1 grotta bove marino n 6 ±0.05 6±0.25 2 grotta binocolo n 5.4±0.10 03/6/21/12 -0.17 ±0.05 5.23±0.15 1 grotta jannarella w 7.10±0.10 03/6/21/12 -0.17 ±0.05 6.94±0.15 1 punta del pino w 7.20±0.10 03/6/21/13 -0.16 ±0.05 7.04±0.15 1 cala del limmo w 7.50±0.10 03/6/21/13 -0.16 ±0.05 7.34±0.15 1 cala articola (s) s 6.45±0.05 03/6/21/13 -0.16 ±0.05 6.29±0.10 1 cala articola (fondo) s 5.90±0.05 03/6/21/13 -0.16 ±0.05 5.74±0.10 1 cala articola (n) s 7 ±0.05 7±0.25 2 grotta verde s 7.10±0.10 03/6/21/13 -0.16 ±0.05 6.94±0.15 1 grotticella d’insurro s 7.04±0.15 03/6/21/13 -0.16 ±0.05 6.88±0.20 1 grotta del belvedere s 7 ±0.05 7±0.25 2 grotta fontolina s 7.22±0.15 03/6/21/14 -0.15 ±0.05 7.07±0.20 1 faraglione di fuori s 8.10±0.15 03/6/21/14 -0.15 ±0.05 7.95±0.20 1 porto di tragara e 8.11±0.05 03/6/21/14 -0.15 ±0.05 7.96±0.10 1 cala del fico e 8.00±0.10 03/6/21/14 -0.15 ±0.05 7.85±0.15 1 punta massullo e 8.00±0.10 03/6/21/14 -0.15 ±0.05 7.85±0.15 1 a ‘vascio funno e 7.52±0.05 03/6/21/14 -0.15 ±0.05 7.37±0.10 1 matermania e 7.50±0.10 03/6/21/15 -0.14 ±0.05 7.36±0.15 1 grotta dei preti e 7.3 ±0.05 7.3±0.25 2 grotta bianca e 7.5 ±0.05 7.5±0.25 2 grotta del moschino e 8 ±0.05 8±0.25 2 grotta sementelle e 7.8 ±0.05 7.8±0.25 2 grotta dei polpi e 7.21±0.10 03/6/21/15 -0.14 ±0.05 7.07±0.15 1 p.ta della chiavica e 7.61±0.05 03/6/21/15 -0.14 ±0.05 7.47±0.10 1 punta del monaco e 7.78±0.15 03/6/21/15 -0.14 ±0.05 7.64±0.20 1 (*) 1=questo lavoro; 2=kyrle (1946-47) l. ferranti & f. antonioli profonda concavità). a tal riguardo si fa notare che anche il solco attuale risulta sviluppato solo nei settori meridionali (in ragione forse della presenza di particolari condizioni idrologiche?). poiché la modalità di distribuzione del solco attuale rispecchia quella del solco tirreniano, e non ci sono ragioni per credere che tali condizioni siano cambiate tra il tirreniano e l’olocene (essendo due periodi interglaciali e con clima comparabile, e non essendo ovviamente variata la struttura geologica dell’isola), è plausibile ipotizzare che il solco tirreniano sia stato maggiormente sviluppato, e dunque attualmente ben osservabile, nel settore meridionale. 3.2.1 costa settentrionale nel settore orientale, a e di marina grande, il solco è ben visibile soltanto allo scoglio ricotta (fig. 4a), dove esso è perfettamente preservato a 6.8 m con la sua mensola e dimensioni costanti, attorno a tutto lo scoglio sia sui quadranti esposti (n) che su quelli protetti (s), mentre risulta assente nella piccola cala a s dello scoglio e nella falesia circostante. in base a queste osservazioni, si può ritenere che le falesie alle spalle dello scoglio siano largamente evolute per crolli negli ultimi 124 ka, e che pertanto lo scoglio sia stato completamente isolato solo in tempi recenti. a ovest di questa località e fino a marina grande, il solco non affiora tranne un piccolo lembo molto eroso all’ingresso della grotta del bove marino e posto a circa 6 m (kyrle, 1946-47). nel settore occidentale di questa costa, un lembo del solco si rinviene in corrispondenza della grotta del binocolo. il solco è sviluppato sopra l’ingresso della cavità alla altezza di 5.2 m (fig. 3), e, lateralmente diviene molto labile, ma viene contraddistinto da una serie di buchi carsici allineati alla stessa quota. lembi di questo solco, a quota paragonabile, sono presenti anche all’imbocco della limitrofa grotta testa del cavallo (kyrle, 1946-47). 3.2.2 costa occidentale doppiata punta dell’arcera, e f ino a punta capocchia, la situazione non muta, con la non preservazione del solco anche nel settore settentrionale del versante occidentale dell’isola. il solco tirreniano appare per la prima volta alla grotta della jannarella, posta in un luogo riparato sul lato n della cala lupinaio (fig. 3). qui il solco si osserva subito sotto il tetto della grotta ad una quota di circa 6.4 m, soprastante una fascia di fori di litofagi che occupa la restante fascia emersa. piccoli lembi del solco, molto slabbrato, si rinvengono nella caletta a sud di punta campitiello ad una quota di circa 6 m. subito a sud di punta del pino, e all’interno della contigua cala del limmo (tombosiello), il solco tirreniano, finalmente ben sviluppato ed associato ad una netta mensola, viene osservato ad una quota di 7.0÷7.3 m (fig. 3). 3.2.3 costa meridionale anche in questo settore dell’isola il solco è preservato in lembi dentro insenature o cavità, dove era stato verosimilmente protetto da una coltre di eolianiti, le quali si osservano in lembi in varie località. un importante affioramento del solco tirreniano è osservabile a cala articola, una stretta insenatura allungata nw-se (fig. 3). sul fondo della cala, evidenze di antichi crolli sono rappresentate da massi di dimensioni ragguardevoli. il solco presente sul lato sud del maggiore di questi blocchi è stato misurato ad una altezza di 5.7 m (fig. 4b). alla base di questo blocco è presente una piattaforma di abrasione con marmitte fossili, che si spinge ad una altezza di 1.5 m. anche sulla falesia che borda a sw la cala è stato misurato il solco (fig. 4c), che qui raggiunge una altezza di 6.3 m. sull’altro lato della cala (ne), il solco si rinviene ad una quota stimata di circa 7 m. su questo lato della cala è anche presente la grotticella dell’articola, una cavità di chiara origine marina costiera, il cui tetto orizzontale si colloca ad una quota di 7 m (cfr. kyrle, 194647). ad est di cala dell’articola, il solco è presente in piccoli lembi ad una quota di circa 7 m presso la grotta verde e sopra l’ingresso della grotta marmolata (cfr. kyrle, 1946-47), ed ancora presso la grotticella d’insurro, dove si associa ad una piattaforma di abrasione a 5 m (fig. 3). nel settore centrale di questa costa il solco non risulta ben evidente, ma ritorna a e di marina piccola presso la grotta del belvedere, dove esso è ben sviluppato a circa 7 m e sovrasta una piattaforma a 4 m, ma immediatamente a sud lo stesso solco raggiunge i 7.2 m con la piattaforma a 3.5 m alla grotta fontolina (fig. 3). nel settore dei faraglioni, il solco si rinviene a circa 6-7 m nel passaggio tra i faraglioni di fuori e di mezzo, e sulla parete del faraglione di fuori è marcato da un allineamento di fori che si spingono fino a 7 m (fig. 3). nell’istmo del faraglione di terra, il solco si associa ad una piattaforma abrasiva a 4 m. 3.2.4 costa orientale in questo settore il solco tirreniano trova il suo massimo sviluppo e preservazione, grazie ad una situazione conservativa rispetto agli agenti erosivi. il solco si segue con continuità lungo le falesie che contornano il porto di tragara, e, nei pressi dell’omonima grotta, raggiunge un’altezza di circa 8 m. a una analoga quota si rinviene nelle calette immediatamente a n, a punta massullo, dove però l’altezza scende a 7.1 m (fig. 3). il solco si segue poi in maniera ininterrotta da questa punta in tutta la grande insenatura di matermania (fig. 4d) e fino a punta della chiavica a nord. presso la grotta a ‘vascio funno il solco è stato misurato a 7.4 m (fig. 4e), e a quota simile intaglia tutto il contorno del faraglione di matermania, e si rinviene alle grotta dei preti e alla grotta bianca. alla grotta del moschino, kyrle riporta la sommità del solco a 8.3 m, con concavità dunque attorno a 8 m, ma possibilmente la sua misura è affetta da errore di tipo strumentale o mareografico. presso grotta delle sementelle, il rilievo originario di kyrle (1946-47) riporta il solco tirreniano ad una altezza che va da 7.5 m (base) a 8.2 (sommità), con punto di flesso verosimilmente intorno a 7.8 m, in buon accordo con le nostre misura. nella stessa sezione, la piattaforma sottostante il solco è scavata in depositi clastici ad una altezza di 2.5 m, e numerosi blocchi tra la grotta bianca e il faraglione di matermania hanno la sommità spianata a circa 3 m (fig. 4d). alla grotta dei polpi, dove la nostra misura pone il solco tirreniano a 7.1 m, la misura di kyrle attesta la 131misure del solco tirreniano ... base del solco a 6.5 m (e dunque con concavità appena sotto i 7 m). subito a nord, nella piccola insenatura allungata delimitata dal promontorio di punta della chiavica, il solco è stato misurato ad una altezza di 7.5 m (fig. 3). a nord di punta della chiavica il solco scompare, salvo un lembo a n di punta del monaco, per ritornare solo allo scoglio ricotta doppiata punta del capo (fig. 3). 4. discussioni e conclusioni 4.1 variabilità laterale dell’altezza degli indicatori del paleolivello marino tirreniano dalla descrizione del solco riportata precedentemente, benché la continuità laterale di questa forma non presenti lunghezze superiori alle centinaia di metri è chiara la sua variabile altezza alla scala metrica lungo le coste dell’isola. si potrebbe obiettare che questa variabilità sia dovuta ad una forte incertezza nella misura. notiamo tuttavia che le nostre misure, benché non coincidenti con quelle di kyrle (le uniche misure dirette del solco e di altri indicatori morfologici), sono abbastanza simili nei punti comuni, e dunque anche le misure di kyrle fanno intravedere questa variabilità d’altezza. una osservazione ancor più significativa riguarda l’andamento di queste variazioni di altezza. piuttosto che essere distribuite in maniera casuale, esse mostrano degli andamenti ordinati e ricorrenti (fig. 3; tab. 1). difatti, le altezze maggiori, anche superiori a 8 m sono raggiunte nel settore se dell’isola, con alcuni picchi minori lungo la costa orientale, dove il solco si mantiene generalmente attorno ai 7.5 m. da questo centro sud-orientale di altezze maggiori, il solco scende progressivamente verso n e verso w verso minori altezze: si mantiene sempre attorno a 7 m nella parte orientale della costa meridionale tra i faraglioni e marina piccola, e continua poi a scendere fino a circa 6 m movendo verso punta carena (fig. 3). l’altezza del solco decresce progressivamente verso n muovendosi lungo la costa occidentale, ed analogamente decresce verso w lungo la costa settentrionale fino a raggiungere il suo valore minimo presso la grotta binocolo a 5.2 m. in base a questa costanza nell’andamento dell’altezza del solco, si può supporre che la sua variabilità non sia casuale o legata ad imprecisione di misura, ma rifletta un processo deformativo vero e proprio che è stato attivo nell’isola di capri dal pleistocene superiore. 4.2 movimenti costieri verticali: indicazione su possibili faglie attive una prima ipotesi per spiegare la variabilità d’altezza del solco tirreniano prevede che essa sia il riflesso di lenti scivolamenti. questa ipotesi si baserebbe sulla presenza di un esteso piano di contatto tra due corpi litologici estremamente differenti, e cioè la superficie di sovrascorrimento che porta i calcari mesozoici a scorrere sopra il complesso argilloso-arenaceo e calcareo-argilloso oligo-miocenico e verosimilmente sopra altri carbonati mesozoici non-affioranti (fig. 2b). in principio, questa situazione risulta estremamente favorevole ad uno scivolamento del corpo superiore, e del solco tirreniano in esso scolpito, sopra tale superficie, a causa del marcato contrasto meccanico fra i due corpi e della presenza di sedimenti argillosi all’interfaccia. nella realtà, due osservazioni concorrono a far ritenere improbabile l’interpretazione descritta. anzitutto, tale superficie di contrasto tra due corpi a comportamento meccanico differente immerge generalmente verso ~sw (fig. 2b), e quindi ci si dovrebbe aspettare uno scivolamento, e il conseguente abbassamento progressivo della quota del solco, muovendosi verso punta carena. l’altezza del solco si abbassa invece essenzialmente verso nw, con un andamento trasversale e non parallelo alla direzione di immersione della superficie di sovrascorrimento miocenico. inoltre, come risulta dalla fig.2b, la superficie in questione risulta estremamente articolata e smembrata da faglie ad alto angolo. pertanto, sarebbe estremamente difficile per tale superficie trasmettere un movimento coerente attraverso tutto il volume roccioso dell’isola. e’ certamente possibile che parte della variabilità d’altezza del solco possa essere giustificata da movimenti locali sopra lembi relativamente integri della superficie di discontinuità, ma sembra improbabile che tale meccanismo possa giustificare la variabilità generale osservata. inoltre, negli affioramenti più continui il solco mantiene una quota costante (es. fig. 4d), e dunque non esistono evidenze di basculamenti sostanziali che dovrebbero essere causati da scivolamenti gravitativi. un meccanismo più verosimile è rappresentato da movimenti lungo il reticolo di faglie che smembrano la superficie di sovrascorrimento (fig. 2b). si tratterebbe certo di movimenti lentissimi, data la bassa differenza d’altezza del solco in settori contigui; nondimeno tali movimenti sono apprezzabili quando siano effettuate misure precise del solco. grazie dunque al solco, è possibile identificare quali faglie, tra quelle riportate nella cartografia ufficiale (d’argenio et al., 2004; fig. 2a) siano state attive negli ultimi 124 ka (fig. 5). per quanto concerne il settore orientale dell’isola, la faglia orientata ~e-w che corre tra il porto di tragara e p.ta massullo, che isola a s il blocco di monte tuoro, sarebbe responsabile del ribassamento del solco verso n dal porto di tragara (circa 8 m) alla cala di matermania (sotto i 7.5 m). una faglia sarebbe pure presente nell’insenatura del porto di tragara per giustificare l’abbassamento del solco da 8 m a tragara a 7 m tra i faraglioni e presso le grotta fontolina e del belvedere (figg. 3 e 5). notiamo che quest’ultima faglia è la sola proposta in questo lavoro e non riportata nella cartografia citata. tutte le faglie discusse potrebbero essere collegate al sistema principale di faglie, orientate ne-sw, che bordano a occidente il settore orientale dell’isola e delimitano i blocchi di s. michele e del castiglione (fig. 2a). quest’ultimo sistema bordiero non provocherebbe ribassamento del solco più ad w, tra i blocchi di castiglione e del monte solaro; pertanto si può ipotizzare un movimento prevalente di tipo orizzontale, che, data l’orientazione locale di estensione (~nnw-sse, cfr. fig. 1), deve essere essenzialmente destro (in maniera consistente con le osservazioni strutturali di castelluccio & napoletano, 1989 e barattolo et al., 1992). a nord, sistemi di faglie ad orientazione ne-sw e 132 l. ferranti & f. antonioli nw-se tra punta della chiavica, scoglio ricotta e punta caterola potrebbero essere responsabili del ribassamento verso il golfo di napoli del blocco ne dell’isola (fig. 5), dove il solco scende sotto i 7 m allo scoglio ricotta e alla grotta del bove marino (fig. 3). l’altezza piuttosto costante del solco sulla costa che borda a meridione il blocco del monte solaro (fig. 3) indica che tale blocco è omogeneo. ciò non vale invece per l’estremità sw dell’isola, dove il solco viene ribassato di circa 1 m alla cala articola, facendo ipotizzare l’attività di una faglia cartografata attraverso la cala (fig. 5) e che borda la parete del limmo. l’alto strutturale del limmo potrebbe essere limitato a n da una faglia cartografata ad andamento e-w, che prosegue a mare sopra punta del pino (fig. 5), e che ribasserebbe il solco di circa 1 m tra il settore sw e il settore di cala lupinaro (fig. 3). nel settore nw dell’isola, l’abbassamento dell’altezza del solco osservata tra la cala lupinaia e la grotta binocolo (fig. 3) suggerisce l’attività di faglie orientate da ~e-w a ~nw-se che corrono tra cala lupinaro e punta sbruffo (fig. 5). l’interpretazione suggerita sembra supportata, anche se con più larga incertezza, dalla variabilità in altezza della piattaforma probabilmente associata al solco tirreniano (fig. 3). 4.3 blocchi strutturali nell’isola di capri in base ai movimenti verticali le informazioni fornite dai marker del tirreniano riguardo la localizzazione delle discontinuità attive negli ultimi 124 ka, unita alla tracciature di queste discontinuità nelle carte geologiche a disposizione, consente di proporre, sebbene in via per ora generica e preliminare, la presenza di blocchi strutturali nell’isola a comportamento differenziale nel recente (fig. 5). la distribuzione della variabilità in altezza del solco tirreniano, con quote più elevate nel settore se dell’isola e un minimo nel settore nw, suggerisce un ribassamento con polarità verso nw, e, nell’area di punta carena, anche un ribassamento verso sw (fig. 5). questa polarità risulta consistente con la subsidenza che negli ultimi 2 milioni di anni ha interessato i golfi di napoli e salerno, dove la crosta si estende in direzione ~nw-se (mariani & prato, 1992; milia et al., 2003), e che è stata responsabile nel pleistocene superiore della dislocazione differenziale, a scala regionale, del marker tirreniano (sezione in fig. 1). le determinazioni della direzione di dislocazione su faglie attive, di assi tensili di terremoti estensionali e di rotture in pozzo mostra che anche attualmente due direzioni di estensione, ~nnw-sse e ~ne-sw, interagiscono in quest’area. pertanto si può ipotizzare che questa deformazione sia stata anche registrata a capri dal solco tirreniano, ribassato verso ne, sw, ed essenzialmente verso nw (fig. 5). in particolare, le faglie che delimitano i blocchi ne e nw dell’isola potrebbero essere delle strutture sintetiche della faglia maestra orientata ne-sw e immergente a nw che viene ipotizzata (cinque et al., 2000) bordare a nw l’alto della penisola sorrentina e delimitare a s il golfo di napoli (fig. 1). tale faglia, se inserita nel contesto regionale della dislocazione, rappresenta a sua volta un sistema minore rispetto alla grande faglia immergente a se ubicata a w di capri (faglia del banco di fuori, fig. 1; milia et al., 2003). 4.4 meccanismi ed architettura delle deformazioni i tassi di scorrimento, mediati dal tirreniano ad oggi, delle faglie perimetrali dei blocchi strutturali ipotizzati a capri, variabili tra 0.006 e 0.013 (fig. 5), risultano 133 fig. 5 carta delle faglie cartografate a capri (fig. 2a) e ritenute attive in questo studio in base alla dislocazione del solco, e tassi di dislocazione verticale in mm/a. map of surveyed faults (see fig. 2a) which are here inferred to be active based on the change in elevation of the tyrrhenian notch, and related vertical displacement rate (mm/a). misure del solco tirreniano ... di almeno un ordine di grandezza inferiori rispetto a quelli delle principali faglie attive e sismogenetiche che caratterizzano l’asse della catena appenninica più ad e calcolati sul medesimo lasso temporale (fig. 1; valensise & pantosti, 2001; maschio et al., 2005). inoltre, l’area di capri e più in generale della costa campana non è attualmente né storicamente sede della grande sismicità tipica della catena appenninica, ed assieme ai limitati rigetti evidenziati nell’isola permette di escludere faglie che agiscono generando grandi terremoti. e’ più plausibile ipotizzare l’esistenza di movimenti lenti di tipo asismico o micro-sismico. questi movimenti avverrebbero su faglie che si raccordano in profondità, assieme alle faglie maestre situate a mare, a piani di scollamento a basso angolo. queste superfici profonde sarebbero analoghe alla superficie di sovrascorrimento più superficiale che porta a capri le rocce carbonatiche sopra quelle argillose-arenacee (figg. 2a e 2b). a differenza di quest’ultima, la superficie profonda, invece di essere smembrata dalle faglie ad alto angolo (fig. 2b) sarebbe integra e perfettamente raccordata ad esse. da dati provenienti da studi di superficie e di sottosuolo in settori limitrofi si può ipotizzare che i carbonati che formano il blocco inferiore di capri (sotto i sedimenti terrigeni e calcareo-argillosi oligo-miocenici) poggino tettonicamente sopra le successioni calcareosilico-marnose del bacino lagonegrese. questo contatto è esposto in superficie circa 70 km a ne di capri, nei m. picentini (fig. 1; scandone et al., 1967; ferranti & oldow, 1999), e si approfondisce verso w. nel cilento, dunque parallelamente a capri lungo la direzione orogenica (nw-se), tale sovrascorrimento viene ipotizzato a 5÷7 km di profondità (berardi et al., 1996; menardi & rea, 1999). dunque è possibile che le faglie in questione “scollino” sopra la superficie regionale di sovrascorrimento dei sedimenti di piattaforma e scarpata carbonatica sopra quelli del bacino lagonegrese, che in corrispondenza di capri potrebbe trovarsi ad una profondità analoga a quanto ipotizzato in cilento. un’ipotesi alternativa è che le faglie di capri siano radicate alla superficie basale del sistema estensionale che attraversa il margine campano, ipotizzata ad una profondità di 10÷12 km, alla quale si raccordano le principali faglie orientate ne-sw che bordano i bacini peri-tirrenici (milia et al., 2003). bibliografia amato a. & montone p. (1997) present-day stress field and active tectonics in southern peninsular italy – geophys. j.int., 130, pp. 519-534. antonioli f., kershaw s. & ferranti l. (2006b) a double mis 5.5 marine notch? – quat. int., 145-146, pp. 19-29. antonioli, f., ferranti, l., lambeck, k., kershaw, s., verrubbi, v. & dai pra, g. (2006a) late pleistocene to holocene record of changing upliftrates in southern calabria and northeastern sicily (southern italy, central mediterranean sea) tectonophysics, 422, pp. 23-40 barattolo f. & pugliese a. (1987) il mesozoico dell’isola di capri quaderni dell’ accademia pontoniana, 8, pp. 1-172. barattolo f., cinque a., d’alessandro e., guida m., romano p. & russo ermolli e. (1992) geomorfologia ed evoluzione tettonica quaternaria dell’isola di capri studi geologici camerti, vol. spec., pp. 221-229. berardi, f., de rosa g. & tozzi m. (1996) vincoli strutturali di superficie per una ricostruzione geometrica del massiccio dei monti alburni, (appennino meridionale) mem.e soc. geol. it., 51, pp. 13-21. brancaccio l., capaldi g., cinque a., pece r. & sgrosso i. (1978) 230th-238u dating of coral deom tyrrhenian beach in sorrentine peninsula (southern italy) quaternaria, 20, pp. 175-183. brancaccio, l., cinque a., romano p., rosskopf c., russo f., santangelo n. & santo a. (1991) geomorphology and neotectonic evolution of a sector of the tyrrhenian flank of the southern apennines (region of naples, italy) zeitschrift für geomorphologie, n.f., suppl.-bd., 82, pp. 47-58. bruno pp, di fiore v, ventura g (2000) seismic study of the ‘41st parallel’ fault system offshore the campanian-latial continental margin, italy tectonophysics, 324, pp. 37–55 caiazzo c., cinque a. & ascione a. (2006) late tertiary–quaternary tectonics of the southern apennines (italy): new evidences from the tyrrhenian slope tectonophysics, 421, pp. 23–51. castelluccio c. & napolitano p. (1989) nuovi dati sulla struttura dell’isola di capri rend. soc. geol. it., 12, pp. 25-28. cinque a., esu d. & gliozzi e. (1986) il riempimento della grotta vascio ‘o funno a capri. primi risultati dello studio geomorfologico e paleontologico. in: cinque a. (1986) guida alle escursioni geomorfologiche (penisola sorrentina, capri, piana del sele e monti picentini riunione annuale gr, naz. geogr. fis. geomorf., amalfi 1986. pubbl. n. 33 del dip. scienze della terra, univ. di napoli, pp. 101-116. cinque a., patacca e., scandone p. & tozzi m. (1993) quaternary kinematic evolution of the southern apennines. relationships between surface geological features and deep lithospheric structures – ann. geofis., 36(2), pp. 249-260. cinque, a., ascione, a. & caiazzo, c. (2000) distribuzione spaziotemporale e caratterizzazione della fagliazione quaternaria in appennino meridionale. in: galadini, f., meletti, c., rebez, a. (eds.) ricerche del gndt nel campo della pericolosità sismica (1996–1999). cnr-gndt spec. publ. roma, pp. 203–218. d'argenio b., violante c., sacchi m., budillon f., pappone g., casciello e. & cesarano m. (2004) capri, bocca piccola and punta campanella. marine andd on-land geology compared. in: "mapping geology in italy", g. pasquarè, c. venturini & g. groppelli (ed.), apat dipartimento difesa del suolo, servizio geologico d'italia, selca, firenze. ferranti l. & oldow j. s. (1999) history and tectonic implications of low-angle detachment faults and orogen-parallel extension, picentini mountains, southern apennines fold and thrust belt, italy tectonics, 18 (3), pp. 498-526. 134 l. ferranti & f. antonioli ferranti l. & oldow j. s. (2005) latest miocene to quaternary horizontal and vertical displacement rates during simultaneous contraction and extension in the southern apennines orogen, italy terra nova, 17, pp. 209–214. ferranti l., antonioli f., mauz b., amorosi a., dai prà g., mastronuzzi g., monaco c., orrù p., pappalardo m., radtke u., renda p., romano p., sansò p. & verrubbi v. (2006) markers of the last interglacial sea-level high stand along the coast of italy: tectonic implications quat. int., 145-146, pp. 30-54. ferranti l., oldow j. s., d’argenio b., catalano r., lewis d., marsella e., maschio l., pappone g., pepe f. & sulli a. (2008) active deformation in southern italy, sicily and southern sardinia from gps velocities of the peri-tyrrhenian geodetic array (ptga) in stampa su: boll. soc. geol. it.. ferranti, l., monaco, c., antonioli, f., maschio, l., kershaw, s. & verrubbi, v. (2007) the contribution of regional uplift and coseismic slip to the vertical crustal motion in the messina straits, southern italy: evidence from raised late holocene shorelines j. geophys. res., 112, b06401, doi:10. 1029/2006jb004473. gars, g. & lippman m. (1984) nouvelle donneès tectoniques dans l’appennin campanien (italie du sud) c. r. acad. scie., ser. ii, 298 (11), pp. 495-500. kyrle g. (1946-47) le grotte dell’isola di capri. l’universo, istituto geografico militare, firenze, ripubblicato come supplemento al n. 2 de l’universo, firenze, 1998, 173 pp. mariani m. & prato r. (1992) i bacini neogenici costieri del margine tirrenico: approccio sismicostratigrafico mem. soc.geol. it., 41, pp. 519531. maschio l., ferranti l. & burrato p. (2005) active extension in val d’agri area, southern apennines, italy: implications for the geometry of the seismogenic belt – geophys. j. int., 162, pp. 591–609, doi: 10.1111/j.1365-246x.2005.02597.x menardi-noguera a. & rea g. (2000) deep structure of the campanian-lucanian arc (southern apennine, italy) tectonophysics, 324, pp. 239-265. milano g., petrazzuoli s. & ventura g. (2004) effects of the hydrotermal circulation on the strain field of the campanian plain (southern italy) terra nova, 16, pp. 205-209. milia a., torrente m.m., russo m. & zuppetta a. (2003) tectonics and crustal structure of the campania continental margin: relationships with volcanism mineral. petrol. 79, pp. 33–47. patacca e., sartori r. & scandone p. (1990) tyrrhenian basin and apenninic arcs: kinematic relations since late tortonian times mem. soc. geol. it., 45, pp. 425–451. romano p. (1992) la distribuzione dei depositi marini pleistocenici lungo le coste della campania. stato delle conoscenze e prospettive di ricerca studi geologici camerti, vol. spec., pp. 265-269. scandone, p., sgrosso i., & vallario a. (1967) la finestra tettonica nella serie calcareo-silico-marnosa presso campagna (monti picentini, salerno) boll. soc. nat. napoli, 76, pp. 3-10. scandone, r., bellucci, f., lirer, l. & rolandi, g. (1991) the structure of the campanian plain and the activity of the neapolitan volcanoes (italy) j. volc. geotherm. res., 48, pp. 1-31. valensise g. & pantosti d. (2001) the investigation of potential earthquake sources in peninsular italy: a review j. seism., 5, pp. 287-306. waelbroeck c., labeyrie l., michel e., duplessy j.c., lambeck k., mcmanus j.f., balbon e. & labracherie m. (2002) sea-level and deep water temperature changes derived from benthic foraminifera isotopic records. quat. scie. rev., 21, pp. 295305. 135 ms. ricevuto il 31 luglio 2007 testo definitivo ricevuto il 9 ottobre 2007 ms. received: july 31, 2007 final text received: october 9, 2007 misure del solco tirreniano ... ojs 591 sigari forti def.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 35 (2), 2022, 91-104 towards a new perspective on the rock art sites-landscape relations in the upper palaeolithic of valcamonica (n-italy). dario sigari 1,2, luca forti 3 1 cnrs-umr 5608 traces, université toulouse jean jaurès, maison de la recherche, toulouse, france. 2 ispc-cnr istituto di scienze del patrimonio culturale, rome, italy. 3 dipartimento di scienze della terra “ardito desio”, università degli studi di milano, milano, italy. corresponding author: d. sigari <dario.sigari@cnrs.fr> abstract: valcamonica, an alpine valley in northern italy, boasts one of europe’s largest concentrations of open-air rock art that had been produced over millennia, from the upper palaeolithic upto historical times. the richness and the long chronology of its rupestrian heritage pose crucial questions around the dynamic dimension of the rock art sites, according to the geomorphology of the territory and the selection of the rocks to be engraved, in the different chronological phases of the valcamonica human occupation. within the frame of the new research project parc-paesaggi dell’arte rupestre camuna (landscapes of valcamonica rock art), we elaborate a dtm map providing a characterisation of the landscape surrounding those rock art and settlement sites attributed to the upper palaeolithic. this led to the recognition of some features linked to the two site typologies. crossrelating the viewshed projections from luine.034, lcr.006 and cividate camuno hut, we access the intervisibility patterns among the sites, highlighting how the valcamonica territory was conceived as a structured space, and performing a least cost path analysis we propose the optimal path between the living and rock art sites. finally, this first step highlights how the implementation of the available data and the elaboration of parc will provide a useful tool to investigate the dynamic aspects of the prehistoric valcamonica, accessing the relationship with the environment resources, the landscape features and the cultural choices along the different rock art chronologies of the valley, and the taphonomy of the rock art too, favouring the elaboration of preservation plans in the future. keywords: northern italy; rock art; alpine landscape; geomorphology; late pleistocene. 1. introduction 1.1. prehistoric rock art and landscape in the last 30 years, the study of the rock art context has become a main topic of investigation (bourdier & fuentes, 2015; bourdier et al., 2017; chippindale & nash, 2004; clottes, 1993a, 1993b; jouteau et al., 2019, 2020; nash & chippindale, 2002; ochoa & garcía -diez, 2018; ortega martínez, 2014; rodríguez-rellán & fábregas valcarce, 2016; sacchi, 1999; sakamoto et al., 2020). beyond the stylistic and chronological aspects, the attention paid to the analysis of the spatial features has permitted to get into different dimensions of rock art, including social, economic, ritual, cognitive, functional, taphonomic and ecological (bourdier, 2013; chippindale & nash, 2004; fairén-jiménez, 2008; mcdonald, 1998; nash, 2011; sigari, 2022; sognnes, 1998; walderhaug, 1998). together with portable art, rock art is the main source to approach non-literate societies in terms of cultural systems and provides a key tool for any archaeological and anthropological research to assess how ancient cultures responded to environmental change. indeed, it is part of dynamic systems that involve both the changes in the environmental context and the cultural relationships of the populations that chose the site and signified it, acting within the landscape and the site itself, and making rock art (arsenault, 2004; bourdier, 2013; hartley & wolley vawser, 1998; hyder, 2004). within the dynamic relationship between the artist/ viewer and the physical environment, where the rock art is placed, several studies have been investigating at both macro and micro-scales, focusing on the relationships with the environment, topography and rock properties (see: chippindale, 2004; gjerde, 2006). differently, other studies have approached the issue of how culturally driven choices might influence rock art locations: being rock art a visual production with strong implications in the communication systems of human groups it may respond to visibility and/or perceptibility reasons (see: bourdier et al., 2017; fossati, 2016; jouteau et al., 2019). within this framework, the open-air rock art contexts are a valid object of study to access the information behind the artistic production, those social and cultural reasons that might have played a role in the selection of the sites and the themes, the use of the territory, and those environmental conditions that influenced the preservation of the rock art evidence. so, the open-air rock art heritage of valcamonica in italy represents a preferential case study to investigate the rock art -landscape-settlements relationships after the last glacial maximum (lgm). https://doi.org/10.26382/amq.2022.05 92 sigari d., forti l. 1.2. the valcamonica landscape between the lgm and the holocene the camonica valley, commonly called valcamonica, is a n-s narrow valley located in the rhaetian alps in northern italy. it develops from the headwaters of tonale pass toward the iseo lake in the province of brescia and it is crossed by the oglio river (fig. 1). the valley has a typical u-shape profile that reveals the glacial origin. reconstructions of the palaeolithic landscape of the valley were provided by pini et al. (2016) and ravazzi et al. (2012). according to these authors, during the lgm, the valley was covered by the oglio glacier, which collapsed around 18.5-17.5 ka cal. bp. the deglaciation, with the melting of the ice masses and paraglacial activities, shaped the valley. here, the onset of fluvial networks and slope instability reworked the unconsolidated sediments, and coalescent alluvial fans developed at the outlet of the lateral valleys and at the toeslopes of the valley walls. furthermore, the maximum extent toward n of the iseo lake shore reached the area surrounding cividate camuno. the subsequent climate amelioration of the bølling -allerød interstadial (14.7-12.9 ka cal. bp) led to the development of an open environment characterised by coniferous forest with the timberline located at c. 1,700 m above sea level (a.s.l.), that lowered at 200 m a.s.l. during the younger dryas deterioration (12.8-11.7 ka cal. bp). finally, at the beginning of the holocene the rise of temperature around 4-6°c led to better climatic conditions with the treeline located at 2,400 m a.s.l.. 1.3. valcamonica rock art the human presence in the valcamonica is witnessed by a unique heritage etched in the stone outcrops, with more than 300,000 engraved figures, belonging to a long chronology from the late upper palaeolithic to historical times (anati, 1992; arcà & fossati, 1994; de marinis & fossati, 2012; sigari & fossati, 2021b). the rock art, which is mainly located in the openair, extends for c. 90 km along the whole length of the valley, on both sides with areas of primary clusters, attributed to the three main areas into which the valley space is commonly divided: the lower, mid and upper valley. the rock art of this valley constitutes an archaeological, artistic, ethnographic and historical heritage of inestimable value, inscribed in the unesco world heritage list in 1979, making the valcamonica the first italian site and the first rock art site in the world to have the unesco world heritage site recognition (fossati, 2003). with its open-air rock art and the long chronology of human occupation, the valcamonica cultural heritage reflects human behaviour in giving special meaning and values to certain places that lasted and changed over millennia. understanding how much this attitude had been influenced by the landscape, according to its natural resources richness, visibility, accessibility, location of the rocks and how the cultural variable might have played is a new research field into which the new project parc-paesaggi dell’arte rupestre camuna (landscapes of valcamonica rock art) wants to investigate. the present paper reports the first step of this research project that was focused on those sites that are considered to belong to the most ancient human presence in the valley. specifically, within this work, authors introduce the first results linked to the analysis of the most ancient phase of the valcamonica occupation, including rocks no. 6 and 34 (sometimes respectively named lcr.006 and luine.034, according to their registration code (see: sigari, 2022)) in luine hill and the cividate camuno palaeolithic site (fig. 1), to understand, according to the geomorphology of the vacamonica, if the site locations may respond to visibility reasons, if and how they were crossrelated, and the valley space was culturally conceived by the first human groups that lived the valley. 2. history of rock art studies the rock art of valcamonica was officially discovered at the beginning of the 20th century, thanks to the geographer walther laeng, who found and published the cemmo boulders in capo di ponte (laeng, 1914). fig. 1 (a) location of the valcamonica (yellow) in the italian peninsula located in the southern sector of italian alps (red square). (b) physiographic map with the location of the palaeolithic engraved rocks no. 6 and 34 of luine hill and the cividate camuno hut (map editing: l. forti). 93 valcamonica rock art sites-landscape nexus in the upper palaeolithic in the following decades, thanks to the anthropologists raffaello battaglia and giovanni marro, most discoveries in valcamonica were made. however, only in the sixties and seventies, more attention was focused on the chronology of different phases of rock art, with the studies undertaken by emmanuel anati (anati, 1975), raffaele de marinis (de marinis, 1995), and others. over the last decades, the development of the documentation methodologies and the increasingly collected data have favoured further precision in the chronology of the valcamonica rock art. so, researchers have been investigating the definition of the sociocultural context in which the rock art was produced and the understanding of the meaning of some themes (see: arcà, 2007; arcà et al., 2008; bossoni et al., 2016; de marinis & fossati, 2012; fossati, 1991, 2015; montanari, 2011; sigari, 2016; tognoni, 2007). in particular, the discussion has been focused on the beginning of the 4th style of valcamonica rock art and the attribution of the so-called ‘oranti’, praying figures. finally, in the very last few years, the review of the palaeolithic engravings of luine has led to discuss the concept of the "protocamunnian" style (anati, 1975; sigari, 2022; sigari & fossati, 2021b). indeed, the earliest phase of the rock art of valcamonica shows connections at a large scale with more contemporary contexts, but nothing in common with the most recent phases. the earliest phase is not in continuity with the holocene phases, it is not a proto-phase. so, the definition of “proto-camunnian” becomes misleading and has to be avoided (sigari, 2022; sigari & fossati, 2021b). 3. the first human groups in the valley 3.1. palaeolithic rock art of the valcamonica despite the high concentration of prehistoric rock art in valcamonica, the number of graphic units attributed to the upper palaeolithic is very limited and concentrated only in two rocks, rock no. 6 and rock no. 34. according to anati (1982), these figures portray only animal figures and number 10: 9 are on rock no. 6 and 1 on rock no. 34.the graphic units can be grouped into two categories: zoomorph (8) and unidentifiable (1). the zoomorphs are deer (2), elk (3), fish (3) and a generic caprid (anati, 1982). a recent review updated the number of graphic units up to 15: 2 deer, 3 elks (6 more elks are actually under-study), 2 fish, 1 caprid and 1 non-figurative motif (sigari, 2022). among the worth mentioning themes, we recognise the elk figures that disappear from the rock art production of the holocene of valcamonica. conversely, more examples of elk representations can be found in the palaeolithic parietal and portable art of italy, respectively in the caviglione cave and tagliente shelter (sigari, 2022), confirming the presence of the animal in the imagery of the human groups that lived in the north of the italian peninsula after the lgm and possibly saw and hunted the animal, as witnessed in the tagliente shelter (fasser et al., 2022). further elk representations can be found in the palaeolithic art of europe as already discussed both in (braun, 2020) and (sigari, 2022). these representations are a valid reference in the study of the palaeoenvironment of the area, since their presence indicates the existence of open humid areas, rich in water, in the vicinity. the 15 petroglyphs of luine were chronologically attributed to the late upper palaeolithic graphic tradition according to their style, theme (especially for the elks, whose presence in the valley was limited to a very short period of time), and to the analysis of the palimpsests, i.e. the overlapping relationships with other motifs (sigari, 2022; sigari & fossati, 2021b). in terms of graphic composition, all the figures, with the exception of the idol-form on luine.034, portray big size animal figures, traced with a main outline marking a disproportioned body and the description of secondary details, e.g. the eye, the nostril and the mouth. they have a strong naturalism and are overlapped by all the other petroglyphs attributed to more recent chrono-cultural horizons (inscriptions, warriors, cup marks, circles…) (sigari, 2022; sigari & fossati, 2021b). 3.2. the oldest human occupation of the valley according to the literature, the human occupation of the valley during the late upper palaeolithic is witnessed only by two sites: the cividate camuno hut (poggiani keller, 1988) and breno castle (fedele, 1988). the discovery of the cividate camuno hut offered an absolute date to what is the most ancient settlement found in camonica valley so far, 13,805±440 bp 14c, 18,067-15,577 cal. bp (poggiani keller, 1988, 2010; sigari & fossati, 2021a). so it can be assumed that the bottom of the valley and the areas sitting at the lowest altitudes, including luine, were freed by the glacier around 16-17 ka bp, offering new territories to be settled (biagi, 2003; ravazzi et al., 2012). the site is located on the left bank of the oglio river, in a sheltered area under the santo stefano cliff at c. 280 m a.s.l. the second site attributed to the epigravettian, according to the lithic assemblage found, is the breno castel site 3 (bc3) with its layer a2 (biagi, 2003; fedele, 1988). however, the few reported data and the absence of dating series to confirm the antiquity of the human occupation of bc3, invite us to prudently not take it into account for the moment. 4. methods preliminary geomorphological analyses were performed through remote sensing mapping to obtain a general flightview of the landscape into which the palaeolithic sites of valcamonica, i.e. cividate camuno hut, rock no. 6 and 34 are. the two rocks are located c. 500 m apart from one another and so are considered two different sites. recent high-resolution satellite imagery was visualised and extrapolated from the quickmapservices plugin (nextgis, 2011) within qgis 3.16 (qgis development team, 2021). digital terrain models-dtm at 5x5 m grid of resolution and the channel network and geological, geomorphological and structural elements were derived from the geoportale of lombardia and from the geological sheet “breno” (regione lombardia, 2020; furlanetto et al., 2018) (fig. 2). elevation-dependent colour scale, hillshade mod for the viewshed analysis (cuckovic, 2016). a viewpoint was fixed after identifying the observer’s location which corresponds to the position of the sites. from here the reference dtm, a radius of 10 km, observer’s height, 1.65 m were set up. afterwards, the visibility analysis was started utilising a binary viewshed that returned two parameters of visibility and non-visibility indicated with the colour red (visible) and white (non-visible). after that els and contour lines at 10 m derived from digital terrain models were elaborated to highlight the distribution of the landforms. in addition, an aspect model map, elaborated on the dtm-digital terrain model, was employed to understand the directions of slope exposures, especially in the proximity of the sites topographic relationships between the sites and their intervisibility were investigated with a qgis plug-in 94 fig. 2 (a) digital terrain model of the study area. (b) schematic geological and geomorphological sketches of the area surrounding cividate camuno. the legend reports the acronyms of the bedrock as in the geological sheet "breno": “bre” breno formation (from here onwards: fm.) (lowermiddle carnic), “esi” esino limestone fm. (upper ladinic-lower carnic), “wen” wengen fm. (upper ladiniclower carnic), “buc” buchenstein fm. (upper anisian-lower ladinic), “prz” prezzo limestone fm. (upper anisian). (c) schematic geological and geomorphological sketches of the area surrounding the luine hill. the legend reports the acronyms of the bedrock as in the geological sheet "breno": “cdg1” pietra simona member of dosso dei galli conglomerate fm. (lower permian), “auc” auccia vulcanite fm.(lower permian), “ver” verrucano lombardo fm (upper permian) and “ser” servino fm. (lower trias) (geological sheet “breno” available at https://www.isprambiente.gov.it/media/carg/78_breno/foglio.html) (map editing: l. forti). sigari d., forti l. fig. 3 tracings of the palaeolithic engraved figures of luine rocks no. 6 (a-d) and 34 (e) (kindly provided by the archaeological cooperative society “le orme dell’uomo”). 95 through the “r.mapcalsimple” tool of qgis, each viewshed of rocks no. 6 and 34, and cividate camuno was interpolated to extract a map into which the common view areas are highlighted. lastly, the pathways between the cividate camuno hut and the luine hill were investigated with the “least cost path analysis” plugin in qgis to find the optimal path between two points in a raster. all the data have been re-projected to wgs 84utm zone 32n reference system. 5. preliminary results 5.1. cividate camuno: geomorphological and archaeological settings cividate camuno is located along the left banks of the oglio river, in an area characterised by an upstream narrowing of the valley, where the river displays meandering plan geometry. this narrowing is associated with the development of an alluvial fan to the nw of the town, formed by the right tributary lanico river that shifts the flow of the oglio river towards se, and by the action of the fault that borders the ridge ne cividate camuno. in the proximity of the town, the valley widens and the plan geometry of the oglio river becomes less meandering and straight. from this point, the river flows through an alluvial plain composed of pebbles and fine sediments. moreover, several colluvial and till deposits were recognised along the slope (forcella et al., 2012) (fig. 2b). in the 80’s, archaeological investigations carried out in 1988, 1992 and 1995, focused on the roman house in via palazzo in cividate camuno. the site is located close to an oglio river bend, in a sheltered area under the santo stefano cliff at c. 280 m a.s.l.. here, different archaeological layers were exposed, confirming the long use of the site since the late upper palaeolithic. indeed, the stratigraphic sequence revealed a level dated to 13,805±440 bp, covered by a mesolithic layer, over which lay, in order, a neolithic (c. 6 ka bp) level, traces of a copper age frequentation (c. 2.5-3 ka bp), evidence of human presence during both bronze and iron age, and finally the roman house, whose foundations compromised the conservation of the bronze and iron age layers (poggiani keller, 2010). the extent of the excavated area is limited but, in correspondence with the so-called vano 1, under a thick sterile sandy level, which was interpreted as the effect of the river flooding (poggiani keller, 2010), a circular living area was brought to light. the size of this surface has a c. 5.6 m diameter and some traces, i.e. pole-holes, led to interpret it as the evidence of a hut. lithic industry, including short scrapers and a bipolar backed point (biagi, 1997), and faunal remains, with the identification of deer, roe deer and ibex (poggiani keller, 2010), were recovered within the area. this material is currently under-review and we are confident that new important novelties will come out. 5.2. luine hill: geomorphological, rock art and archaeological settings the luine hill (45°53'17''n, 10°10'46''e) covers an area of approximately 850 x 600 m that is commonly divided into three parts/localities: crape, simoni and luine. at the confluence of the oglio and dezzo rivers, it reaches an altitude of 365 m a.s.l. (anati, 1962, 1982; laeng, 1956; sigari & fossati, 2021b). the hill is composed of the lower permian sandstone of pietra serena, member of dosso dei galli conglomerate formation (assereto & casati, 1965; lombardi, 2006; furlanetto et al., 2018) (fig. 2c). the geomorphological setting of the area was valcamonica rock art sites-landscape nexus in the upper palaeolithic 96 among the whole record of engraved rocks, two are worth mentioning, rock no. 6 and 34, which have the most ancient petroglyphs of valcamonica (anati, 1974, 1975, 1982; sigari & fossati, 2021a, 2021b). the figures of this ancient period are very few and represent animals, mainly elk, deer, and fish figures, and a geometric motif that show features that tie them to the style and chronology of the upper palaeolithic art of western europe (sigari, 2022; sigari & fossati, 2021a, 2021b) (fig. 3). to deepen the issue of the chronology and the use of the site, during the triennium 1968-1970, anati and his team excavated 26 test pits to explore the possible presence of any archaeological deposit within the area of the hill. they discovered small deposits from the neolithic, bronze and iron ages (anati, 1974, 1982). in the test pit n. 5, in front of rock no. 53, archaeologists brought to light the residuals of a burning area, though no evidence of material culture were found associated with it. nevertheless, anati hypothesised that it would represent the most ancient stratigraphic layer, witnessing the human presence “soon after the retreat of the glacier” since it “probably dates back to the pre-boreal or beginning of boreal, so c. 9,000 years ago” (anati, 1982: 53). 5.3. rock no. 6 rock no. 6 (45°53'19''n, 10°10'58''e) is a large and wide rock outcrop on the north-eastern side of the luine hill. it is located in crape at 290 m a.s.l.. the main enmodelled after the melting of lgm ice masses. the hill is bordered to the east by the valley floor where the oglio river flows in the alluvial plain with a meandering river planform. here, the alluvial plain is composed of gravel and fine sediments. despite the heavy anthropisation, with impactful urbanisation in this part of the alluvial plain, different palaeochannels were recognised in the inner part of the main meander, which is sw to luine hill. differently, southwards, where the dezzo river flows into the oglio river, the wide alluvial fan shifts and influences the river shape of oglio river with the development of a straight reach. finally, west to the luine hill, at the footslope of the walls of the valley, till and slope deposits were recognised with several erosional scarps (fig. 2c). thanks to its 102 engraved rocks, with c. 20,000 petroglyphs, luine hill boasts the third richest concentration of rock art of valcamonica. though all the engraved motifs belong to a long chronology, the majority of them date between the neolithic and bronze age, in contrast with the mid-valley where most of the petroglyphs belong to the iron age. among the main figurative themes of luine we recognise zoomorphic, anthropomorphic, and geometric figures, other symbols including circles, meanders, spirals, zig-zags, labyrinths, and camunnian roses, weapons, shield-forms, and tools, idol-forms, topographics, dwellings and inscriptions. all these graphic units were engraved in the rocks, both pecking and scratching. sometimes both techniques were used to do a figure. fig. 4 panoramic view over rock no. 6 and the valley (photo: d. sigari). sigari d., forti l. 97 graved surface slopes eastwards to the oglio river. on its western side, the inclination of the rock changes to an almost vertical surface exposed to the west. lcr.006 measures 25 x 11 m. rock no. 6 is situated just above an 80 metres high overhang, as such it is impossible to access it from the bottom of the valley. the only accessible way to reach it is from the west, following a relatively easy path along the eastern side of the hill (sigari & fossati, 2021b) (fig. 4). the rock was discovered by g. laeng and e. süss in 1955. three years after their brief report in the commentari dell’ateneo di brescia (laeng, 1956). e. anati and his team started the recording of the rock, counting up to 342 figures (anati, 1962, 1982). however, the scholar never completed the documentation work, admitting that “it was a chore and remained incomplete” (anati, 1982: 7). the main figurative themes of this engraved rock are: animals, topographic, inscriptions and weapons, circles. all of them were pecked and/or scratched. 5.4. rock no. 34 rock no. 34 (45°53'11''n, 10°10'40''e) is a multifaced sandstone outcrop at an altitude of 315 m a.s.l. in the locality of luine. it is one of the largest rocks within the luine hill and has one with the most abundant amount of engravings in valcamonica. the luine.034 is set on the southern slope of the hill, dominating the lower part of the valley and the area of confluence of the dezzo river and oglio river. it can be accessed both from its upper part and from the lower section, according to the visit direction path (sigari & fossati, 2021b) (fig. 5). the rock was fully brought to light in the early seventies, and, at the end of its cleaning, around 1,000 engravings were identified (anati 1974; 1982). among the most impressive graphic units found on this rock, there is a deer figure with the head turned backwards dated to the palaeolithic (sigari, 2022). the recent review undertaken by one of the authors (d.s.) showed that the deer overlaps a big non-figurative motif, witnessing two graphic phases at least (sigari, 2022). these graphic units are in the so-called sector a which corresponds to the most elevated part of the rock outcrop. the sector is westward oriented and is characterised by different figurative themes: animals, weapons, shield-forms, warriors. all of them were pecked and/or scratched. conversely, the panel b that is southward oriented extends over a wider surface than panel a and has more figurative themes, including labyrinth, zigzag, and camunnian rose which were all done from the neolithic onwards. 6. discussion and further perspectives the first maps elaborated within the framework of the parc project, here presented and discussed, consider the evidence of the most ancient human presence in the valcamonica, which seems to be datable soon after the lgm, i.e. around 17,000 years bp (see: sigari, 2022). at that time the valley floor of valcamonica was completely occupied by the water of the paleolake of iseo that reached the area just south of cividate camuno. therefore, the landscape in which the palaeolithic human groups lived at that time was characterised by water and steep walls of the valley. within this scenario, the main topographic features visible from cividate camuno were the ridges that actually rise from the valley floor. one of these was surely the luine hill, which is at the footslope of the valley wall and in the correspondence of the junction of the dezzo and oglio rivers, forming an elevated and protected place. the abundance of water resources after the retreat of the glacier supports the chronological terminus post quem for the engraved elk figures that were probably inspired by the presence of this animal in the area at that time. to further strengthen it, we recall the elk refig. 5 (a) panoramic view from rock no. 34 toward south over the valley to the iseo lake; (b) the deer with the turned head of rock no. 34 (photos: d. sigari). valcamonica rock art sites-landscape nexus in the upper palaeolithic 98 engravings of the luine hill were done in the same period, and aiming to understand any mobility system between the two sites, the cross correlation between palaeoenvironmental reconstruction and preliminary geomorphological analysis suggests that possible linking routes were located on the right footslope side of the valley, that was some metres above the level of the actual alluvial plain. furthermore, with the goal of establishing the existence of any visibility pattern between the rock art and settlement sites, and any intentionality in terms of territory control from them, we used the viewshed analysis to estimate the visibility range from each site over the surrounding territory. the hut location in cividate camuno offers a limited view over the valley and the control area does not cover all of the luine hill area (fig. 6a). differently, from the elevated position of rock no. 6, the viewshed projection highlights a visibility area that reaches the vicinity of the santo stefano cliff, under which the hut was found (fig. 6b). the location of rock no. 34 on the southern slope of the luine hill excludes any territory control to the north. nevertheless, it provides a preferential view over mains from the tagliente shelter dating back to between c. 17-14 ka bp (fasser et al., 2022). to provide a characterisation of the post-lgm palaeolithic landscape surrounding the selected sites, the dtm map clearly enhances the features of the camonica valley, which is an alluvial valley with very steep sides (fig. 2). the dtm served as well as a base-map to understand some key issues, i.e. where the sites are, what the relationship between landscape and rock art is and how the rock art was spatially organised into the valley space if there was any relationship between the symbolic space and the living areas and finally between rock art and visibility. what emerges so far is that the living area is at the bottom of the valley under the santo stefano cliff and close to the river, at a lower altitude, in order to have the best protection and the easiest access to water resources too. differently, the position of the engraved rocks on the hill sides and the edge of an overhang favours a wide view over the surrounding territory, but a scarce, almost unfeasible view over the sites from the bottom of the valley. assuming that the cividate camuno hut and the fig. 6 (a) viewshed elaboration map where the visible and non-visible areas within a 10 km of circle buffer from the cividate camuno hut are reported. (b) viewshed elaboration map where the visible and non-visible areas within a 10 km of circle buffer from the engraved rock no. 6 of luine hill are reported. (c ) viewshed elaboration map where the visible and non-visible areas within a 10 km of circle buffer from the engraved rock no. 34 of luine hill are reported. (d) viewshed elaboration map where the common visible areas from all the three considered sites are reported (map editing: l. forti). sigari d., forti l. 99 fig. 7 (a) view over the valley from rock no. 6 (photo: d. sigari). (b) historical photo taken during the first documentation activities of rock no. 6 (photo kindly provided by the historical archive of the centro camuno di studi preistorici, eur62:lxxx-10). the white arrows point common key-elements of the landscape surrounding rock no. 6, that clearly show how much the landscape has changed and the urbanisation has grown during the last 60 years (editing: d. sigari). valcamonica rock art sites-landscape nexus in the upper palaeolithic the valley till the iseo lake for some kilometres. furthermore, the palaeolithic engravings of luine.034 are on an almost vertical panel, which faces the west. so, hiding the figures from the bottom of the valley and making them visible only to the viewers who get close to it is evident (fig. 6c). the invisibility of the engravings from a distance invites us to consider cultural choices in selecting hidden places from where there is a good view over the surrounding territory, but that requires a displacement to the site. so, the concept of private and public art in the valcamonica rock art, which has recently been sketched in a paper about the holocene parietal evidence (fossati, 2016), seems to be finally relevant in approaching the palaeolithic rock art too. more comparative cultural suggestions that may confirm the intentional selection of specific hidden sites can be found in the ethnography, where scholars report how some populations chose isolated places with a panoramic view of the surrounding landscape (e.g.: loubser, 2010; sundstrom, 2006). to check and establish any intervisibility pattern among the selected sites and to understand the use of the landscape and the relationships among the rock art and settlement sites, we crossrelated the viewshed projections from luine.034, lcr.006 and cividate camuno hut highlighting how the commonly visible areas are almost absent and limited to a few steep points on the right hydrographic bank and on escarpment edges of the altissimo mountain (fig. 6d). therefore, the almost total absence of common intervisibility points reinforces the idea of driven cultural choices in selecting isolated and hidden sites to produce parietal engravings during the palaeolithic. the luine rock art of the pleistocene responds to limited access and visibility rules. in other words, it was not public art but required knowledge of the place, and the maker/viewer was obliged to go on the site to finally access the panel. undoubtedly, the issue of visibility is strictly linked to the changing landscapes. difficulties in advancing hypotheses based on the modern landscape of valcamonica are clearly evident already by the use of historical photos, which show how much the anthropic impact transformed the valley aspect during the last 80 years (fig. 7). therefore, it is easy to imagine how much the valcamonica landscape has changed over the last 17 100 fig. 8 (a) digital terrain model of the lower sector of valcamonica where the palaeolithic paleoshore of the iseo lake based on the reconstruction by pini et al., (2016) is reported in light blue. the dark blue colour indicates the actual shore of the lake. (b) least cost path analysis applied to the study area between cividate camuno and luine hill. (c) interpolation of the ancient shore line of the iseo lake and the least cost path analysis. with the white dash line we hypothesised a possible road that connects cividate camuno and the luine hill rock art site (map editing: l. forti). sigari d., forti l. millennia, both for climatic and environmental reasons and for anthropic actions. however, despite the almost lack of data for prehistoric times, we can reasonably consider how dynamic environmental conditions may have favoured the selection of the rocks, the accessibility to the sites and the visibility among them. so, according to the previous literature, we can suggest that the amelioration of the climatic conditions and the subsequent environmental changes led to differently characterise the visibility patterns within the valley space. if after the lgm an open environment characterised the valley, possibly exposing the sandstone outcrops and/or facilitating the intervisibility between the sites, later the expansion of the timberline at lower altitudes reduced any visibility pattern. so, the valcamonica territory was possibly conceived as a structured space with living areas which were easily accessible going upriver, and ritual places which were hidden and required the knowledge of the valley to access the rock art. finally, crossrelating the dtm elaboration with the paleoenvironment reconstruction based on what was reported in pini et al. (2016) (fig. 8a), and the least cost path analysis that highlights the fastest and easiest path connecting cividate camuno and luine hill (fig. 8b), we suggest that the possible path, between the cividate camuno hut and the luine hill followed by the first settlers of the valley, run along the western foothills of the valley beside the paleolake shore (fig. 8c). surely, we are aware that we could take into account only very little data. however, we keep an open mind to further integrate any novelty that may implement our knowledge about the first settlers of the valcamonica. moreover, we consider the implementation of the record as a useful tool to evaluate more parameters such as the terrain orientation to analyse the taphonomic impact on the rock art preservation according to the vegetation growth, humidity, weathering and anthropic impact. indeed, the elaboration of the topographic parameters through the application of the automated plugin qgis at a higher resolution with a bigger number of data will certainly provide more interesting information. to do that, the parc project that we are undertaking considers approaching more recent chronologies of the valcamonica rock art too. the next focus will be the paspardo territory in the mid-valley, where there is a higher concentration of engraved rocks with images belonging to different phases. this approach will consider a multi-scale analysis that will permit to access the relationship with the environmental resources, the landscape features and the cultural choices along the different rock art chronologies of the valley. therefore, we are confident that the newly started parc project will finally provide new insight into the dynamic aspects of the rock art both in valcamonica and other open-air contexts, tracing new research avenues for the archaeology of valcamonica and the rock art research. acknowledgements “parc-paesaggi dell’arte rupestre camuna” project is funded by the centro camuno di studi preistorici. the recording and analysis of the palaeolithic engravings of luine hill is part of the “cervidi della valcamonica (cer.val.): tra incisioni rupestri, tradizioni popolari e cambiamenti climatici” project funded by the caicomitato centrale gruppo terre alte. we are thankful to maria grazia gobossi e mario marini whose work in preserving and promoting the luine archaeological park is fundamental and precious, and they keep on with this important work with sincere curiosity and great enthusiasm. we are grateful to francesca roncoroni for supervising the development of the parc project, angelo eugenio fossati for facilitating the access to the tracings of the archaeological cooperative society “le orme dell’uomo”. last, but not least, we thank sujitha pillai for assisting with the written english review. references anati e. (1962) dos nuevas rocas prehistoricas grabadas de boario terme (brescia) y el periodo ii del arte rupestre de val camonica. ampurias, 24, 35-66. anati e. (1974) lo stile sub-naturalistico camuno e l’origine dell’arte rupestre camuna. bollettino del centro camuno di studi preistorici, 11, 59-83. anati e. (1975) evoluzione e stile nell’arte rupestre camuna. edizioni del centro, capo di ponte (bs). anati e. (1982) luine. collina sacra. edizioni del centro, capo di ponte (bs). anati e. (1992) i camuni. jaca book, milano. arcà a. (2007) le raffigurazioni topografiche, colture e culture preistoriche nella prima fase dell’arte rupestre di paspardo. le più antiche testimonianze iconografiche nella storia dell ‘agricoltura e della topografia. in fossati a.e. (ed.), la castagna della valcamonica. dalla valorizzazione delle colture allo sviluppo della cultura. atti del convegno interdisciplinare, paspardo 6-7-8 ottobre 2006. comune di paspardo, 35-56. arcà a., casini s., de marinis r.c., fossati a.e. (2008) arte rupestre, metodi di documentazione: storia, problematiche e nuove prospettive. rivista di scienze preistoriche, lviii, 351-384. arcà a., fossati a.e. (eds.) (1994) sui sentieri dell’arte rupestre. le rocce incise delle alpi. storia, ricerche, escursioni. edizioni cda, torino. arsenault d. (2004) rock-art, landscape, sacred places: attitudes in contemporary archaeological theory. in chippindale c., nash g. (eds.), the figured landscapes of rock-art. looking at pictures in place. cambridge university press, cambridge, 69 -84. assereto r., casati p. (1965) revisione della stratigrafia permo-triassica della val camonica meridionale (lombardia). rivista italiana di paleontologia e stratigrafia, 71, 999-1097. biagi p. (1997) recenti ricerche sul mesolitico della valcamonica (brescia). bollettino del centro camuno di studi preistorici, 30, 23-40. biagi p. (2003) alcuni problemi concernenti il popolamento preistorico della valle camonica. notiziario del centro camuno di studi preistorici, 12-20. bossoni l., roncoroni f., montanari e., sigari d. (2016) 101 valcamonica rock art sites-landscape nexus in the upper palaeolithic vite 119 e la bosca 006. due rocce incise a paspardo. bollettino del centro camuno di studi preistorici, 42, 62-78. bourdier c. (2013) rock art and social geography in the upper paleolithic. contribution to the sociocultural function of the roc-aux-sorciers rockshelter (angles-sur-l’anglin, france) from the viewpoint of its sculpted frieze. journal of anthropological archaeology, 32(4), 368-382. doi: 10.1016/j.jaa.2013.05.005 bourdier c., fuentes o. (2015) beyond visibilities: a plurality of functions? the rock art sites of comarque and cap-blanc (dordogne, france). arkeos. proceedings of the xix international rock art conference ifrao 2015 (cáceres, spain, 31 august-4 september 2015), 37, 1319-1322. bourdier c., fuentes o., pinçon g., baleux f. (2017) methodological contribution to the integrated study of european palaeolithic rock art: the issue of the audience and the perceptibility of roc-auxsorciers rock art (angles-sur-l’anglin, france). quaternary international, 430, 114-129. doi: 10.1016/j.quaint.2016.12.009 braun i. (2020) the elk/moose (alces alces) in the upper palaeolithic art of western europe. paléo. 30, 58-74. doi: 10.4000/paleo.5126 chippindale c. (2004) from millimetre up to kilometre: a framework of space and of scale for reporting and studying rock-art in its landscape. in chippindale c., nash g. (eds.), the figured landscapes of rock-art. looking at pictures in place. cambridge university press, cambridge, 102-117. chippindale c., nash g. (eds.) (2004) the figured landscapes of rock-art. looking at pictures in place. cambridge university press, cambridge. clottes j. (1993a) contexte archéologique externe. in groupe de reflexions sur l’art pariétal paléolithique (ed.), l’art pariétal paléolithique. cths, paris, 27-35. clottes j. (1993b) contexte archéologique interne. in groupe de reflexions sur l’art pariétal paléolithique (ed.), l’art pariétal paléolithique. cths, paris, 49-58. cuckovic z. (2016) advanced viewshed analysis: a quantum gis plug-in for the analysis of visual landscapes. the journal of open source software, 1(4), 32. doi: 10.21105/joss.00032 de marinis r. c. (1995) problemes de chronologie de l’art rupestre du valcamonica. notizie archeologiche bergomensi, 2, 99-120. de marinis r.c., fossati a.e. (2012) a che punto è lo studio dell’arte rupestre della valcamonica. preistoria alpina. l’arte preistorica in italia. atti della xlii riunione scientifica dell’iipp. trento, riva del garda, val camonica, 9-13 ottobre 2007, 46 (ii), 17-43. fairén-jiménez s. (2008) british neolithic rock art in its landscape. journal of field archaeology, 32(3), 283-295. doi: 10.1179/009346907791071584 fasser n., visentin d., fontana f. (2022) characterising late palaeolithic manufacturing traditions: backed points production methods in the late epigravettian sequence of riparo tagliente (ne italy). journal of archaeological science: reports. 42, 103343. doi: 10.1016/j.jasrep.2022.103343 fedele f. (1988) l’uomo, le alpi, la valcamonica 20000 anni al castello di breno. la cittadina, boario terme. forcella, f., bigoni c., bini a., ferliga c., ronchi a., rossi s. (2012) breno: note illustrative della carta geologica d'italia alla scala 1: 50.000: foglio 078. fossati a.e. (1991) l’età del ferro nelle incisioni rupestri della valcamonica. in la guarda r. (ed.), immagini di una aristocrazia dell’età del ferro nell’arte rupestre camuna. contributi in occasione della mostra castello sforzesco aprile 1991-marzo 1992, milano. comune di milano, settore cultura e spettacolo. raccolte archeologiche e numismatiche, milano, 11-72. fossati a.e. (2003) “but they are only puppets …”. problems of management and educational programs in rock engraving national parks, valcamonica and valtellina, lombardy, italy. rock art research, 20(1), 25-30. fossati a.e. (2015) una nuova figura di mantello frangiato sulla roccia 9 della loc. castello presso paspardo, valcamonica (bs). bullettin d’etudes préhistoriques et archeologiques alpines, xxvxxvi, 269-274. fossati a.e. (2016) pubblico e privato nella tradizione rupestre della valcamonica, italia. bcsp bollettino del centro camuno di studi preistorici, 41, 31-44. furlanetto g., ravazzi c., pini r., vallè f., brunetti m., comolli r., novellino m.d., garozzo l., maggi v. (2018) holocene vegetation history and quantitative climate reconstructions in a high-elevation oceanic district of the italian alps. evidence for a middle to late holocene precipitation increase. quaternary science reviews, 200, 212-236. doi: 10.1016/j.quascirev.2018.10.001 gjerde j.m. (2006) the location of rock picture is an interpretive element. universitetet i bergen arkeologiske skrifter nordisk, 3, 197-209. hartley r., wolley vawser a.m. (1998) spatial behaviour and learning in the prehistoric environment of the colorado river drainage (south-eastern utah), western north america. in chippindale c., taçon p.s.c. (eds.), the archaeology of rock-art. cambridge university press, cambridge, 185-211. hyder w.d. (2004) locational analysis in rock-art studies. in c. chippindale, g. nash (eds.), the figured landscapes of rock-art. looking at pictures in place. cambridge university press, cambridge, 85 -101. jouteau a., feruglio v., bourdier c., camus h., ferrier c., santos f., jaubert j. (2019) choosing rock art locations: geological parameters and social behaviours. the example of cussac cave (dordogne, france). journal of archaeological science, 105, 81-96. doi: 10.1016/j.jas.2019.03.008 102 sigari d., forti l. jouteau a., feruglio v., lacanette d., carré s., noé n., jaubert j. (2020) understanding the perception and appropriation of space in palaeolithic decorated caves: new methods and tools, with the examples of cussac and lascaux caves. rock art research, 37(2), 137-154. laeng g. (1914) cemmo (capo di ponte). in guida d’italia del touring club italiano. piemonte, lombardia e canton ticino. touring club italiano, milano, p. 595. laeng g. (1956) una nuova zona di incisioni rupestri a boario terme in valle camonica. commentari dell’ateneo di brescia, 3-18. lombardi d. (2006) revisione stratigrafica del membro della pietra simona. permiano inferiore. prealpi bresciane. università degli studi di pavia. loubser j.h.n. (2010) prefigured in the human mind and body: toward an ethnographically informed cognitive archaeology of metaphor and religion. time and mind, 3(2), 183-213. doi: 10.2752/175169610x12632240392794 mcdonald j. (1998) shelter rock-art in the sydney basin a space-time continuum: exploring different influences on stylistic change. in chippindale c., taçon p.s.c. (eds.), the archaeology of rockart. cambridge university press, cambridge, 319335. montanari e. (2011) aristocrazia tra decadenza e tradizione: armi ed armati sulla roccia 1 di dos sottolajolo (paspardo). bullettin d’etudes préhistoriques et archeologiques alpines, xxii, 197-214. nash g. (2011) replicating cultural landscapes: interpreting rock-art in the valcamonica, lombardy, italy. landscapes, 12(2), 1-19. doi: 10.1179/lan.2011.12.2.1 nash g., chippindale c. (eds.) (2002) european landscapes of rock art. routledge, london. nextgis (2011) quickmapservices: easy basemaps in qgis. retrieved 15 january 2022 from https:// nextgis.com/blog/quickmapservices. ochoa b., garcía-diez m. (2018) the use of cave art through graphic space, visibility and cave transit: a new methodology. journal of anthropological archaeology, 49, 129-145. doi: 10.1016/j.jaa.2017.12.008 ortega martínez p. (2014) visibility: a new outlook to the study of palaeolithic art. preliminary research. in garcía a., garcía j., maximiano a., ríosgaraizar j. (eds.), debating spatial archaeology. proceedings of the international workshop on landscape and spatial analysis in archaeology. santander, june 8th 9th, 2012. instituto internacional de investigaciones prehistóricas de cantabria, santander, 259-266. pini r., ravazzi c., aceti a., castellano l., perego r., quirino t., vallè f. (2016) ecological changes and human interaction in valcamonica, the rock art valley, since the last deglaciation. alpine and mediterranean quaternary, 29(1), 19-34. poggiani keller r. (1988) cividate camuno (bs). via palazzo. resti di insediamento paleo-mesolitico e neolitico. notiziario della soprintendenza archeologica della lombardia, 27-29. poggiani keller r. (2010) la capanna più antica della valle. 13.000 anni fa sulle rive del fiume. itinera, 5, 19-22. qgis development team (2021) qgis geographic information system. open source geospatial foundation project. retrieved 20 february 2022, from https://qgis.org/en/site/index.html. ravazzi c., badino f., marsetti d., patera g., reimer p. j. (2012) glacial to paraglacial history and forest recovery in the oglio glacier system (italian alps) between 26 and 15 ka cal bp. quaternary science reviews, 58, 146-161. doi: 10.1016/j.quascirev.2012.10.017 regione lombardia (2020) geoportale della regione lombardia. retrieved 5 december 2021, from https://www.geoportale.regione.lombardia.it/. rodríguez-rellán c., fábregas valcarce r. (2016) measuring the spatially-related perceptibility of prehistoric rock art. some initial notes. in rodríguez-rellán c., fábregas valcarce r. (eds.), public images, private readings: multi-perspective approaches to the post-palaeolithic rock art. proceedings of the xvii uispp world congress (1 -7 september 2014, burgos, spain). archaeopress, oxford, 41-50. sacchi d. (ed.) (1999) l’art paléolithique à l’air libre le paysage modifié par l’image (actes du colloque international, tautavel-campôme, 7-9 octobre 1999). gaep & géopré, carcassonne. sakamoto t., pettitt p., ontanõn-peredo r. (2020) upper palaeolithic installation art: topography, distortion, animation and participation in the production and experience of cantabrian cave art. cambridge archaeological journal, 30(4), 665668. doi: 10.1017/s0959774320000153 sigari d. (2016) warfare in valcamonica rock art, new emerging data from paspardo area. in coimbra f., delfino d. (eds.), the emergence of warrior societies and its economic, socialand environmental consequences. proceedings of the session a3c of the uispp world congress. 1st-7th september 2014, burgos, spain. archaeopress, oxford, 7990. sigari d. (2022) upper palaeolithic rock art of the italian peninsula. edizioni del centro, capo di ponte (bs). sigari d., fossati a.e. (2021a) i cervidi nelle rocce: primi risultati del progetto di ricerca sulle raffigurazioni di cervidi nell’arte rupestre della valcamonica. bollettino del comitato scientifico centrale del cai, ottobre, 22-39. sigari d., fossati a.e. (2021b) the so-called protocammunian rock art of luine. towards a review. bollettino del centro camuno di studi preistorici, 45. sognnes k. (1998) symbols in a changing world: rockart and the transition from hunting to farming in mid norway. in chippindale c., taçon p.s.c. (eds.), the archaeology of rock-art. cambridge university press, cambridge, 146-162. sundstrom l. (2006) reading between the lines: ethnographic sources and rock art interpretation 103 valcamonica rock art sites-landscape nexus in the upper palaeolithic approaches to ethnography and rock art. in keyser j.d., poetschat g., taylor m.w. (eds.), talking with the past: the ethnography of rock art. oregon archaeological society publications, portland, 49-69. tognoni e. (2007) le raffigurazioni architettoniche nell’arte rupestre camuna e i ritrovamenti di paspardo. in fossati a.e. (ed.), la castagna della valcamonica. dalla valorizzazione delle colture allo sviluppo della cultura. atti del convegno interdisciplinare, paspardo 6-7-8 ottobre 2006. comune di paspardo, 85-96. walderhaug e.m. (1998) changing art in changing society: the hunters’ rock-art of western norway. in chippindale c., taçon p.s.c. (eds.), the archaeology of rock-art. cambridge university press, cambridge, 285-301. 104 sigari d., forti l. ms. received: june 1, 2022 revised: october 14, 2022 accepted: november 14, 2022 avaiable online: december 5, 2022 impaginato atti il quaternario italian journal of quaternary sciences 1155(1), 2002, 111-120 ssooiill ggeeoocchheemmiissttrryy aanndd ppeeddoollooggiiccaall pprroocceesssseess.. tthhee ccaassee ssttuuddyy ooff tthhee qquuaatteerrnnaarryy ssooiillss ooff tthhee mmoonnttaaggnnoollaa sseenneessee ((cceennttrraall iittaallyy)) ee..aa..cc.. ccoossttaannttiinnii11,, mm.. aannggeelloonnee22,, rr.. nnaappoollii11,, 1istituto sperimentale per lo studio e la difesa del suolo, mi.p.a., p.za d’azeglio, 30, 50121 firenze 2enea, tein-chim, c.r. casaccia, c.p. 2400, 00100 roma a.d. abstract the role of soil as an environmental filter is widely acknowledged, although not fully understood in all the processes involved. unfortunately in the monitoring of some environmental parameters indicative of soil quality, such as heavy metals, we can observe a general tendency to simplify the issue. in fact, data refer only to a part of soil, i.e. the uppermost part, or the plow layer, while characteristics and processes which occur in the lower parts of the profile are neglected. on the other hand many soils, like paleosols, which are quite widespread in italy, have a very thick and complex profile, in which a significant elemental concentration can take place as a result of natural, pedological processes. this stresses the importance of in-depth investigation when the object of laboratory analysis is to provide advice for specific land uses. aim of this work was to study the role played by soil forming processes in addressing element behaviour in some soils of the montagnola senese territory. results of this work show an accumulation of many elements with respect to parent material. however this trend was not uniform in all cases, pointing out that their re-distribution in soil horizons can be related to different pedogenetic processes. the accumulation of some elements in soils can be to some extent related to organic matter content, ph and cation exchange capacity, but mainly in the upper horizons, while clay richness seems to play a more important role in determining the element concentration in all soil horizons: correlation coefficients with high level of significance have been found between clay and ti, k and cr, but also fe, zn and pb are correlated with clay content, with the exception of those horizons, which are affected by element redistribution caused by oxidative-reductive processes. several elements show a time dependent concentration process. ti, k, na and mn seem to increase through time from the holocene, to the upper and middle pleistocene; cr, pb and zn, similarly to fe, from holocene up to the lower pleistocene. the accumulation process proceeds along with clay neo-genesis and illuviation, but it can be affected by clay impoverishment, due to ferrolysis, together with the element mobilisation produced by reducing conditions. if clay impoverishment is characteristic of eluvial horizons and bleached streaks of fragipan and glossic horizons, mobilisation of fe, zn and pb is manifested in the reduced parts of almost all the horizons with bad drainage. riassunto l’importanza del suolo come ‘filtro ambientale’ è generalmente riconosciuta, sebbene non ancora pienamente compresa in tutti i processi che ne sono coinvolti. nel monitoraggio di alcuni parametri ambientali indicativi la qualità del suolo, come ad esempio i metalli pesanti, si tende in genere a semplificare le cose, riferendosi solo ad una parte del suolo, quella più superficiale, o strato lavorato, mentre le caratteristiche degli orizzonti sottostanti ed i processi che avvengono nella parte profonda del profilo non sono considerati. d’altra parte molti suoli, in particolare i paleosuoli, piuttosto diffusi in italia, sono caratterizzati da un profilo molto profondo e complesso, nel quale si può verificare un significativo incremento di elementi per cause naturali, legate a processi pedologici. scopo di questo lavoro è quello di studiare il ruolo svolto dai processi pedogenetici nell’indirizzare l’accumulo di elementi nei suoli della montagnola senese. i risultati del lavoro evidenziano il verificarsi di un accumulo di elementi rispetto al materiale parentale; tuttavia questa tendenza non si è realizzata allo stesso modo per tutti i suoli. ciò suggerisce che la ridistribuzione degli elementi negli orizzonti pedologici può essere messa in relazione con differenti processi pedogenetici. l’accumulo di alcuni elementi nei suoli è stato correlato al contenuto in sostanza organica, al ph e alla capacità di scambio cationico, soprattutto nei primi orizzonti, mentre un ruolo maggiore è svolto dall’argilla nel determinare il contenuto in elementi di tutti gli altri orizzonti. coefficienti di correlazione altamente significativi sono stati riscontrati tra argilla e ti, k e cr ma anche con fe, zn e pb. tuttavia questa evidenza non si manifesta negli orizzonti caratterizzati da una ridistribuzione degli elementi provocata da processi di ossidoriduzione. molti elementi evidenziano un processo di accumulo dipendente dal tempo. ti, k, na e mn mostrano di aumentare col tempo passando dall’olocene al pleistocene superiore e medio; cr, pb e zn, analogamente al ferro, dall’olocene fino al pleistocene inferiore. il processo di accumulo procede di regola assieme alla neogenesi ed accumulo di argilla, ma può essere influenzato da altri due processi: l’impoverimento di argilla, attivo negli orizzonti eluviali, glossici e nei fragipan, e la mobilizzazione degli elementi, che avviene in tutti gli orizzonti che presentano condizioni riducenti. key words: trace and heavy metals, soil geochemistry, paleosols, siena, italy parole chiave: metalli pesanti ed in traccia, geochimica dei suoli, paleosuoli, siena, italia. 11.. iinnttrroodduuccttiioonn knowledge of the concentration of trace elements in soil, especially heavy metals, is of utmost environmental relevance when the purpose is to determine the pollutant rate related to anthropogenic influences. in the last decade several western countries have carried out many research programs to establish valid background levels to be used as reference points to discriminate contamination. unfortunately in our country a systematic and organic national program to assess trace element distribution and background values in soil is far from being completed. as a direct consequence we can witness the great difficulties encountered by national and regional legislation to establish valid and useful reference points to assess contamination. however, little is known about the thresholds which can cause damage to the soil-plant ecosystem and the limits can vary widely according to the different countries' approach to this problem (adriano et al., 1995; tab. 1). besides, recent studies have demonstrated the irreversible effects upon the soil microbial ecosystem of soil metal concentrations having values which are well below european and italians limits (brookes, 2001). element content in soils may vary according to agricultural practices, but, to a great extent natural causes also play a role. the influence of parent material, for instance, is well-known (fergusson, 1990; angelone & bini, 1992); nevertheless the contribution of long-lasting natural processes, like those occurring in paleosols, has not been well-established yet. moreover, legislation related to soil quality and pollution generally tends to simplify the issue, in particular it refers to only a part of the soil, that is the uppermost part, or the plow layer, while characteristics and processes of the lower parts of the profile are often neglected. this simplification does not take into account the possibility that the upper part of the soil can be thinned, or even removed by some agricultural practices or because of soil erosion. another simplification concerns soil horizons often considered to be homogeneous, whereas element accumulation in soils, and particularly in paleosols, can occur only in parts of some horizons. this can be of great relevance in interpreting analytical results for practical purposes, not only those related to the environment, but also to the agricultural uses of soils (costantini, 1999), and should steer the soil sampling. in mediterranean countries, and particularly in italy, paleosols are quite widespread and a significant elemental concentration can occur in some parts as a result of paleopedological processes. these processes are usually accompanied by a more or less pronounced soil reddening or the formation of nodules, but exceptions are frequent. in this work, the elemental distribution in some soils of the montagnola senese territory has been studied and put in relation to main soil properties (ph, clay, om, cec), major elements (fe, al), estimated soil age, soil morphology (genetic horizons, redoximorphic features) with the aim of studying the role played by soil forming processes in addressing element behaviour. 22.. mmaatteerriiaallss aanndd mmeetthhooddss 22..11 ssooiill aannaallyyssiiss the soils of the montagnola senese territory have been previously studied by costantini et al. (1996) to explain the genesis of fragipan and other close-packed horizons. more than 50 profiles of the area have been described and analysed. a dozen of them, developed on acid metamorphic rocks and on mainly siliceous colluvial and alluvial deposits, were also studied for their element composition. soil description followed the soil survey staff methodology (1993), routine analysis was in compliance with the italian official methods (siss, 1985). plinthite nodules were submitted to the test of wood and perkins (1976), with immersion of samples for two hours in water, to check the persistence of aggregation. the counting of nodules and pseudomorphic nodules in the sands was made on 26 horizons pertaining to seven selected soils, utilising the optical microscope at different magnifications and considering 300 grains from each sand class; percentage values of nodules were then referred to percentage of fine earth, without taking into account possible differences in specific gravity. geochemical analysis was performed on 67 soil horizons belonging to 12 representative profiles. soil samples were dried beforehand at 40°c, ground and sieved through a 2 mm teflon coated sieve. homogenised sub-samples were ground with an agate ball mill to obtain a fraction < 0.1 mm. approximately 500 mg of homogenised sub-sample were weighed in a teflon bomb. metal extraction was carried out adding a mixture 5 ml of aqua regia (5 ml) and ultra pure hf (2 ml). saturated h3bo3 was successively added to buffer the excess of hf. major and trace element analysis was carried out by perkin elmer 5100 aas at flame (k, na, mn); and with an aas equipped with a zeeman background corrector for cd, cu, cr, pb and zn. icp was used to analyse ca, al, mg, fe and ti. all the analytical procedures were tested beforehand with a data quality control programme using international soils crms, samples duplicate and reagent blanks. 112 total soil metal concentration, mg kg-1 soil european union year ccdd ccuu ccrr ppbb zznn community 1986 1-3 50-140 100-150 50-300 150-300 france 1988 2 100 150 100 300 germany 1992 1.5 60 100 100 200 united kingdom 1989 3 135 400 300 300 italy 1992 1.5 100 (a) 100 300 (a) = bartlett test for soil oxidation capacity <1 table1 maximum concentrations of metals allowed in agricultural soils treated with sewage sludge (after adriano et al., 1995). concentrazioni massime di metalli permesse nei suoli agricoli trattati con fanghi di depurazione (da adriano et al., 1995). e.a.c. costantini, m. angelone & r. napoli 33.. rreessuullttss aanndd ddiissccuussssiioonn 33..11.. ggeenneerraall oouuttlliinneess ooff tthhee aarreeaa the study area is a small ridge located in central tuscany, covering just under 20 km2. it is made up of several hills, with dominant heights ranging from 400 to 500 meters and a maximum of 671 meters a.s.l. the area underwent intense geomorphological evolution during the pliocene and quaternary, with alternating periods of erosion and stability. the rising of the ridge led to the erosion of the slopes, but several surfaces remained stable (e.g. karst depressions) or were stable over a long period (e.g. colluvial areas). four main lithological units could be distinguished: i) acid metamorphic rocks, consisting of chloritic and sericitic fine-grained schist, jasper, quartzose micro and macro conglomerate and violet schist breccias (mesozoic); ii) calcareous rocks, composed of flint limestone, marble, dolomite and cavernous limestone mesozoic in age, but partially reworked by the miocene sea; iii) mainly calcareous or iv) mainly siliceous colluvial and alluvial deposits, the mineralogy of which derives from the mixing of the above mentioned rocks. climatic data for the area were obtained from simignano (si) and siena. at simignano (43°18' lat. n; 419 m a.s.l., 8 km west of siena) the average annual rainfall is 1019 mm, with maximum in october (119.8 mm) and minimum in july (36.4 mm). in siena (43°19' lat. n; 348 m a.s.l.) the average annual temperature is 13.2°c, the warmest month is july (22.1°), the coldest is january (5.8°). the soil moisture regime, evaluated by the newhall computation (newhall, 1972) is "udic" with a water holding capacity of 200, 100 and 50 mm, whereas the soil temperature regime, according to soil taxonomy (soil survey staff, 1999) is "mesic" (8<t<15° c). land use of the area is mainly woodland, with dominance of chestnut trees (castanea sativa) on acid metamorphic rocks and acid soils, and evergreen holm oak (quercus ilex) on shallow soils on limestone. agricultural lands are limited by the stoniness of the soils on limestone and the steepness of morphology; however, almost a third of the area is cultivated with small grain crops and maize, grasslands, vineyards, olive groves and orchards. possible sources of soil contamination are limited to the few farms which practice spreading pig slurries on soils before cereal cultivation. these soils, however have not been included in this study. 33..22 ssooiill ccllaassssiiffiiccaattiioonn aanndd eessttiimmaatteedd aaggee regarding soil age, the only available dating is from the bottom of a studied profile, ascertained to be at least cromerian (lower middle pleistocene, panizza, 1985) by means of paleonthological finds (fondi, 1972). however, on the basis of a geomorphological reconstruction, the micromorphological evidence and chemical characteristics, it was possible to assess the approximate age of the selected soils as dating back to holocene, upper and middle pleistocene, and to lower pleistocene ages (costantini et al., 1996). micromorphological results, in particular, concur with those found by cremaschi & sevink (1987) in soils belonging to the same pleistocene ages in italy. according to the soil taxonomy (soil survey staff, 1999) the soils were classif ied as udorthents, dystrudepts, hapludalf, fragiudalf, fraglossudalf, paleudalf and plinthaqualf, or as leptosols, cambisols, luvisols, alisols and plinthosols according to the world reference base for soil resources classification (fao et al, 1998). clay neo-genesis and accumulation within b horizon is a common feature of many of them, as well as iron release from parent material leading to soil reddening. iron and manganese mobilisation and concentration, due to oxidation and reduction processes and expressed as bleached streaks, reddish and black mottles or as nodule elaboration, is another frequent process. other processes, such as fragipan and glossic horizon formation, clay impoverishment inside bleached streaks (i.e. ferrolysis, brinkman, 1970) and soil acidification, are connotative of specific environmental conditions (costantini et al., 1996). 33..33 oovveerraallll ggeeoocchheemmiiccaall cchhaarraacctteerriissttiiccss aanndd ttrreennddss descriptive statistics of major and trace element concentration are reported in table 2, while the rock composition can be seen in table 3. on average, the heavy metal concentration of these soils is similar to or lower than those considered typical for italian not-polluted soils (angelone & bini,1992). amongst the studied elements, aluminium and iron are the most abundant, as expected considering the nature of the parent material (duchaufour, 1977); however, maximum values of cd, cu, cr, pb and zn are more interesting, being close to or higher than the regulation threshold (tab.1). these limits can be exceeded in superficial horizons (cu, cr) as well as within the b horizons (cd, cu, cr, pb, zn) and, only in the case of cu and cr, also in the deepest horizons. the recorded data do not allow us to assume soil pollution (kabata-pendias & pendias, 1992); however they do emphasise the practical interest of knowing the possible causes of high element content of some of these soils. although we can observe a probable accumulation of many elements in soil, with respect to the parent material, this trend has not taken place in the same way for each element. this suggests that element re-distribution within the soil horizons can be related to different pedogenetic processes. actually, some elements tend to slightly increase or remain constant with depth (zn, al, mg, cu, na), some others localise within surface (ca) and b horizons (mn) or concentrate in b horizons (k, cd, ti, cr, pb and fe). a first step towards the understanding of the causes of accumulation was obtained by correlating the element concentration in soil horizons to clay and organic matter, ph and cation exchange capacity. organic matter was found significantly correlated (p<0.01) with cd (r=0.99) and, considering only the superficial a and e horizons, with ca (r=0.52); ph was found to be well correlated with cd (r=0.98) and, only in the upper horizons, with cu (r=0.62); cec was correlated with cd (r=0.87) and, also in this case only for the a and e horizons, with al (r=0.72), mg (r=0.56), k (r=0.72), mn (r=0.54) and zn (r=0.85). these results seem to indicate that, as already observed by others authors (kabata-pendias & pendias,1992, mckeague & wolynetz, 1980), standard chemical parameters, and in particular organic matter, can significantly influence the accumulation of some elements in soils, mainly in the upper horizons. 113soil geochemistry ... 114 a ll so il ho riz on s aa ll cc aa mm gg kk nn aa ff ee mm nn tt ii cc dd cc uu cc rr pp bb zz nn oo ..mm .. cc ..ee ..cc .. cc llaa yy pphh m ea n 20 73 7 45 5 19 54 13 88 9 28 07 29 67 7 53 7 15 26 0, 13 50 ,3 79 ,1 26 ,4 64 ,0 0, 63 10 ,2 27 ,6 6, 2 m in im um 50 00 20 ,0 22 ,0 46 00 72 0 56 00 34 ,0 17 8 0, 01 13 ,0 19 ,0 1, 00 12 ,0 0, 01 5, 0 5, 0 4, 2 m ax im un 66 80 0 25 80 50 20 42 20 0 15 60 0 93 00 0 26 30 37 90 1, 70 11 4 16 8 12 0 16 0 4, 20 20 ,6 60 ,0 8, 3 s ta nd ar d er rp r 12 15 4 49 7 10 11 56 24 24 25 17 44 3 55 8 74 5 0, 28 25 ,3 36 ,1 21 ,3 31 ,9 0, 12 0, 4 1, 6 0, 1 n um be r of d at a 67 67 66 67 67 67 67 67 53 67 67 67 66 53 55 67 66 o nl y a an d e ho riz on s m ea n 19 24 7 87 2 19 37 11 18 4 24 05 24 24 3 60 5 12 25 0, 08 46 ,5 72 ,3 20 ,7 50 ,1 1, 59 10 ,4 18 ,7 6, 1 m in im um 54 00 36 ,0 66 4 46 00 12 10 10 20 0 16 3 29 3 0, 03 13 ,0 26 ,0 1, 00 12 ,0 0, 70 5, 0 5, 0 4, 5 m ax im um 39 70 0 25 80 34 60 16 10 0 46 00 43 90 0 20 50 22 90 0, 15 11 1 16 6 46 ,0 11 6 4, 20 15 ,0 37 ,0 7, 5 s ta nd ar d er ro r 10 12 4 72 7 84 8 37 40 82 3 10 20 0 46 1 73 1 0, 04 29 ,5 42 ,1 12 ,4 27 ,9 0, 26 1, 5 2, 7 0, 3 n um be r of d at a 15 15 15 15 15 15 15 15 12 15 15 15 15 15 6 15 14 o nl y b ho riz on s m ea n 21 04 5 33 7 19 14 15 00 4 29 37 32 80 9 53 6 17 12 0, 16 48 ,8 83 ,7 30 ,3 67 ,9 0, 22 10 ,2 31 ,9 6, 3 m in im um 50 00 20 ,0 23 6 71 00 87 0 80 00 34 ,0 17 8 0, 01 15 ,0 19 ,0 4, 0 15 ,0 0, 01 5, 4 10 ,0 4, 6 m ax im um 66 80 0 13 90 42 40 42 20 0 15 60 0 93 00 0 26 30 37 90 1, 70 11 3 16 8 12 0 16 0 0, 80 20 ,6 60 ,0 8, 3 s ta nd ar d er ro r 18 86 80 ,4 14 0 85 9 38 7 27 78 88 10 0 0, 05 3, 1 4, 9 3, 37 4, 5 0, 03 0, 5 1, 7 0, 2 n um be r of d at a 47 47 47 47 47 47 47 47 38 47 47 47 47 36 46 47 47 o nl y c ho riz on s m ea n 22 32 0 31 4 24 96 11 52 4 27 88 16 53 0 34 6 68 6 0, 04 75 ,4 55 ,8 6, 40 70 ,3 0, 80 10 ,5 14 ,0 4, 9 m in im um 12 20 0 22 0 22 ,0 66 30 72 0 56 00 55 ,0 33 0 0, 02 28 ,0 33 ,0 1, 00 16 ,0 0, 10 5, 7 10 ,0 4, 2 m ax im um 38 70 0 44 6 50 20 18 70 0 91 70 22 45 0 84 7 16 70 0, 07 11 4 11 4 13 13 3 1, 50 13 ,1 22 ,0 5, 1 s ta nd ar d er ro r 53 38 39 ,2 10 22 22 22 16 05 29 07 14 7 24 8 0, 01 16 ,9 14 ,9 2, 40 25 ,0 0, 70 2, 4 2, 2 0, 2 n um be r of d at a 5 5 4 5 5 5 5 5 3 5 5 5 4 2 3 5 5 t yp ic al v al ue s fo r ita lia n no tpo llu te d so ils ( af et er a ng el on e an d b in i, 19 92 ) 37 00 0 90 0 0, 53 51 ,0 10 0 21 ,0 89 ,0 t ab le 2 d es cr ip tiv e st at is tic s of m aj or a nd tr ac e el em en t c on ce nt ra tio n (p pm ) co m pa re d to m ai n ch em ic al v al ue s s ta tis tic he d es cr itt iv e de lla c on ce nt ra zi on e de gl i e le m en ti m ag gi or i e in tr ac ce ( pp m ), c on fr on ta ti co n i p rin ci pa li ca ra tte ri ch im ic i e.a.c. costantini, m. angelone & r. napoli on the other hand, the clay content seems to be more relevant. correlation coefficients with a high level of significance have been found between clay of each horizon and ti (r=0.65), k (r=0.58), and cr (r=0.55), while the correlation was less evident with zn (0.38), fe (0.31; p<0.05) and pb (0.29; p<0.05). on the other hand, fe (r=0.91), zn (r=0.58) and pb (r=0.57) were found highly correlated with clay in all horizons, excluding those with plinthite and the reduced parts. thus these last three elements show a concentration trend similar to the others, i.e. they follow the time and pedoclimate dependent clay increase, but it is also influenced by the oxidative-reductive processes. aluminium and iron are the dominant elements in the studied soils, so it could well be that other elements were associated with them. in actual fact, the former was found well correlated only with mg (r=0.68), and the latter with cr (r=0.58). if we do not take into account plinthite and reduced horizons, however, aluminium is fairly correlated with mg (r=0.69) and cd (0.57), as well as iron with ti (r=0.47), k (r=0.42), pb (r=0.59) and zn (r=0.41). even in these cases, the prominent role played by the element mobilisation, due to the change in their chemical state, is highlighted. finally, aluminium was found correlated with ca (r=0.52), but only in the superficial horizons. 33..44 eelleemmeenntt ccoonncceennttrraattiioonn aanndd ssooiill aaggee in a previous work, it was demonstrated that the ageing of the studied soils is characterised by a progressive increase in the clay content, a slight reduction of the cec of clay and a marked increase in total and free iron content, which is particularly impressive in the oldest soils (costantini et al., 1996). in this work we have grouped the studied soils according to their estimated age – holocene, upper and middle pleistocene, lower pleistocene and statistically tested them to underline possible significantly differing element concentrations. although the relationships between element supplying and age have to be considered only as indicative, because of the several other factors affecting the element concentration viz. lithological and chronological discontinuities between horizons of the same soil, or differences between parts of the same horizon some possible indications about the elements which are more time dependent can be pointed out (table 4). among the studied soil components, al, cd, cu and mg do not show any significant trend related to soil age. on the other hand, cr, pb and zn show an accumulation process similar to that of iron, i.e. a progressive increase with age, which is particularly evident for cr (fig. 1); ti and k are significantly lower in holocene soils, rather than in older soil horizons, whereas na and mn have higher mean values in soils and horizons attributed to 115 al ca mg fe ti k na mn cd cu cr pb zn quartzose 9000 176 320 6900 430 5830 1030 50 0,06 4 192 155 61 micro conglomerate sericitic fine61200 296 4300 39200 3540 24000 3815 2190 0,06 87 107 325 138 grained schist violet schist 58000 320 600 26000 1980 28100 4190 51 0,05 12 136 210 73 chloritic schist 3000 360 220 7000 180 4600 2250 6 0,21 8 6 32 24 jasper 11700 140 1320 9400 5500 740 258 0,04 48 10 28 mean 28580 258 1352 17700 1533 13606 2405 511 0,08 32 90 181 65 table 3 element concentration in some samples of the main parent material lithotypes of the studied soils (ppm). concentrazione degli elementi in alcuni campioni dei litotipi principali del materiale parentale dei suoli studiati (ppm). ccaa ffee ttii kk nnaa mmnn ccrr ppbb zznn oo..mm.. cc..ee..cc.. ccllaayy pphh holocene soil horizons mean 745 18039 757 8886 1896 664 46.1 12.3 41.9 1.23 8.06 12.6 5.26 number of data 18 18 18 18 18 18 18 18 17 16 11 18 17 upper and middle pleistocene soil horizons mean 351 26402 1870 17115 4398 802 73.4 21.6 67.6 0.31 11.2 28.9 5.78 number of data 20 20 20 20 20 20 20 20 20 11 18 20 20 lower pleistocene soil horizons mean 347 39159 1767 14771 2276 276 103 38.4 74.4 0.39 10.4 35.9 6.95 number of data 29 29 29 29 29 29 29 29 29 26 26 29 29 table 4 element concentration in soil horizons of different estimated age (ppm) compared to main chemical values; elements, ph and clay are significantly different for soil age with the kruskal-wallis test with p<0.001, c.e.c. and o.m. with p<0.05. concentrazione degli elementi negli orizzonti pedologici di differenti età stimate (ppm) confrontati con i principali caratteri chimici; gli elementi, il ph e l’argilla sono differenti significativamente per età del suolo con il test di kruskal-wallis con p<0.001, c.e.c. e o.m. con p<0.05. soil geochemistry ... the upper and middle pleistocene. finally there is a clear decrease in ca with soil ageing, possibly due to the leaching process and the scanty supply from the parent material. 33..55 eelleemmeenntt aaccccuummuullaattiioonn ppaatthhwwaayyss aanndd ssooiill mmoorrpphhoo-llooggyy three profiles have been selected to exemplify how the accumulation process becomes evident in soils. they illustrate different profile morphology and element accumulation pathways, as a consequence of the pedogenetic processes which have occurred. profile 9 fragic paleudalf (soil taxonomy 1999); chromi-profondic luvisol (bathifragic) (wrb 1998). holocene in age in its upper part (a, e and bt horizons), pleistocene in age in the deepest horizons, it is characterised by evident weathering, leading to the release of elements, in particular iron, which gives the soil its reddish-brown colour, as well as clay neo-formation and illuviation into depth. moreover, a close-packed horizon has been formed (fragipan) which limits water and root penetration and causes the formation of bleached tongues (figures 2 and 3; a, e, bt, 2btx1, 4bc, r, etc.: designations for soil horizons1). in this profile, iron distribution is similar to that of clay; inside the bleached streaks, where root penetration is active, ferrolysis determines clay and iron depletion, but does not affect ti and k (photo 1). profile 47 aquic fraglossudalf (soil taxonomy 1999); glossalbi-stagnic luvisol (profondic, chromic, fragic) (wrb 1998). lower pleistocene in age, it is older and redder than the previous soil; pedological processes are similar to those of profile 9, but more pronounced (photo 2). in particular, depletion in the reduced zones affected not only clay and iron, but also potassium and titanium (figures 4 and 5). in the same geomorphological unit, but in a lower position, soils like profile 48 plinthaquic paleudalf (soil taxonomy 1999); eutri-endostagnic plinthosol (wrb 1998) are widespread (photo 3). they have neither fragipan nor clay impoverishment inside the bleached streaks. the groundwater has been fluctuating inside this iron-rich soil for so long that iron movement and aggregation in form of concretions and nodules of plinthite has been produced (photo 4). the presence of water has provoked iron reduction and removal from the streaks, but clay has not been removed, rather it tends to concentrate inside the bleached zones. as a result, the oxidised zones of the profile became coarser in particle size and a residual concentration of clay and titanium in the bleached mottles took place (figures 6 and 7). the process of iron concentration, from dispersed in the groundmass to aggregated in nodules, can be better appreciated by optical stereo-microscope. the 116 f ig .1 c r co nt en t o f s tu di ed p ro fil es a cc or di ng to th ei r es tim at ed a ge ( pp m ) c on te nu to in c r de i p ro fil i s tu di at i i n re la zi on e al la lo ro e tà s tim at a (p pm ) 1 a = surface horizon with organic matter accumulation, ap = ploughed horizon, e = eluvial horizon, bt = horizon with clay accumulation, btx = fragipan, btg = bad drained horizon with clay accumulation, btgv = as before with plinthite, bc = weathered and partially structured bedrock, r = hard bedrock. number preceding letters indicates lithological and/or chronological discontinuity; those following letters indicate sub horizon; red or -o: reduced, bleached streaks or tongues; ox or -o: oxidized masses. e.a.c. costantini, m. angelone & r. napoli frequency of nodules and pseudomorphic nodules in four sand fractions of two horizons from seven of the examined soils are reported in figure 8. nodules in the sand fractions were present in all the studied profiles, but reached striking percentages in the profile 48 (up to more than 30% of the fine earth), especially in the finer 117 photo 1 particular of the bleached streaks inside the fragipan of profile 9, where ferrolysis takes place. particolare delle striature biancastre all’interno del fragipan del profilo 9, dove vi è ferrolisi. sand fractions. in most cases, the colour of the nodules fell to hue 2.5 yr (munsell soil colour charts), but could reach 10 r in the most rubified soils (profiles 25 and 47) and 10 yr in the yellowish ones (profiles 46 and 48). as a general rule, the finer the sand fractions, the redder the nodules. this could be related to the presence of a fig. 2 fe and k distribution within profile 9 distribuzione del fe e del k all’interno del profilo 9 fig. 3 ti and clay distribution within profile 9 distribuzione del ti e dell’argilla all’interno del profilo 9 fig. 4 fe and k distribution within profile 47 distribuzione del fe e del k all’interno del profilo 47 fig. 5 ti and clay distribution within profile 47 distribuzione del ti e dell’argilla all’interno del profilo 47. soil geochemistry ... progressive long-lasting process, which induces transformation of iron from hematite into goethite, as already observed by other authors in some oxisols of central brazil and in laterite (jeanroy et al., 1991; curi & franzmeyer, 1984, 1987; da motta & kämpf, 1992; macedo & bryant, 1987; nahon, 1991). 118 photo 3 profile 48. the groundwater has been fluctuating inside this iron-rich soil so long as to produce an huge iron aggregation in the form of concretions and nodules of plinthite. profilo 48. la falda freatica ha fluttuato così a lungo in questo suolo ricco di ferro da produrre un enorme accumulo di ferro sotto forma di concrezioni e noduli di plintite. photo 2 the soil profile 47 is older and redder than the former profile 9; depletion in the reduced zones affected not only clay and iron, but also potassium and titanium. il suolo del profilo 47 è più antico e più rosso del precedente profilo 9, l’impoverimento nelle zone ridotte interessa non solamente l’argilla e il ferro, ma anche il potassio e il titanio. fig. 6 fe and k distribution within profile 48 distribuzione del fe e del k all’interno del profilo 48 fig. 7 ti and clay distribution within profile 48 distribuzione del ti e dell’argilla all’interno del profilo 48 44.. ccoonncclluussiioonnss element distribution along soil profiles well reflects the long-lasting influence of weathering and of soil forming processes that have been operating on the area. the accumulation of some elements in soils can to a certain extent be put in relation to organic matter content, ph and cation exchange capacity, but mainly in the upper horizons. on the other hand, clay richness seems to play a more important role in determining the element e.a.c. costantini, m. angelone & r. napoli 119 photo 4 particular of the horizon with plinthite nodules. the anaerobic conditions have provoked iron reduction and removal from the streaks, but clay has not been removed, rather it tends to concentrate inside the bleached zones, and along with it titanium. the yellowish mass is very rich of nodules and concretions. particolare dell’orizzonte con noduli di plintite. le condizioni anaerobiche hanno provocato la riduzione del ferro e la sua rimozione dalle striature, ma l’argilla non è stata rimossa, piuttosto tende a concentrarsi all’interno delle zone biancastre, e con lei il titanio. la massa giallastra è molto ricca di noduli e concrezioni e, al suo interno, gli ossidi di ferro sembrano essersi trasformati da ematite a goethite. fig. 8 nodules and pseudomorphic nodules in the sand fractions of selected soils (%) noduli e noduli pseudomorfi nelle frazioni sabbiose di suoli selezionati (%) soil geochemistry ... concentration in all soil horizons. correlation coefficients with high level of significance have been found between clay and ti, k and cr. also fe, zn and pb are related to clay content, especially if the horizons which are affected by element redistribution caused by oxidative-reductive processes are excluded. several elements show a time dependent concentration process. ti, k, na and mn seem to increase with time from the holocene, to the upper and middle pleistocene; cr, pb and zn, similarly to fe, from holocene up to the lower pleistocene. the accumulation process proceeds along with clay neo-genesis and illuviation, but it can be affected by clay impoverishment, due to ferrolysis, besides element mobilisation, produced by reducing conditions. if clay impoverishment is characteristic of eluvial horizons and bleached streaks of fragipan and glossic horizons, mobilisation of fe, zn and pb is manifested in the reduced parts of almost all the horizons with bad drainage. all in all, the soils of the montagnola senese highlight that in the study of soil geochemistry there is a need for careful investigation of what is often a complex reality. soils, and particularly paleosols, where a significant element accumulation can take place as a result of natural pedological processes, have to be considered not only in terms of their superficial aspects (the plow layer), but also in the characteristics of the entire profile. for this reason, a thorough soil field survey is essential in evaluating the capacity of the site to accept pollutants, in order to guarantee the maintenance of soil filter and sink capacity, and should be provided for by regulations. aacckknnoowwlleeddggeemmeennttss the soil survey and routine analysis were carried out by napoli and costantini, the geochemical analysis by angelone. the text was elaborated and prepared by costantini on the basis of a common discussion. authors thanks prof. claudio bini of the university of venice (italy) for his helpful criticisms on style and content of the manuscript. rreeffeerreenncceess adriano d.c., chlopecka a., kaplan d. i., clijsters h., & vangrosveld j., 1995 soil contamination and remediation: philosophy, science and technology. proceeding of the third icobte – int. con. on the biogeochemistry of the trace elements. paris, cdrom. angelone m. & bini c., 1992 trace elements concentrations in soils and plants of western europe. in: biogechemistry of trace metals, ed. by domy c. adriano. lewis pub. 19-60. brinkman r., 1970 ferrolysis, a hydromorphic soil forming process. geoderma, 33, 199-206. brookes, p. c. 2001 changes in soil microbial properties as indicators of adverse effects of heavy metals. mem. sc. fis. e nat., 118, xxxxiivv, pp.205-227. costantini e.a.c., 1999 soil survey and chemical parameters evaluation in viticultural zoning. atti del 2° convegno internazionale “zonazione viticola”. siena, maggio 1998, 127-137. costantini e.a.c., napoli r., & bragato g., 1996 properties and geographic relevance of fragipan and other close-packed horizons in a non-glaciated mediterranean region. geografia fisica e dinamica quaternaria, 1199, (11), 29-45. cremaschi m. & sevink j., 1987 micromorphology of paleosols chronosequences on gravelly sediments in northern and central italy. in: soil micromorphology. proceeding of the viith int. working meet. of soil micr., association franc. pour l'etude du sol, paris, 577-582. curi n. & franzmeier d.p., 1984 toposequence of oxisols from the central plateaux of brazil. soil sci.soc. am.j., 4488, 341-346. curi n. & franzmeier d.p., 1987 effect of parent rocks on chemical and mineralogical properties of so-me oxisols in brazil. soil sci.soc. am.j., 5511, 153-158. da motta p.e.f. & kämpf n., 1992 iron oxide properties as support to soil morphological features for prediction of moisture regimes in oxisols of central brazil. in: z.pflanzernähr, bodenk, 115555, 385-390. duchaufour p., 1977 pedologie 1, pédogenèse et classification. masson, paris. fao, isric & isss, 1998 world reference base for soil resources. world soil resources report, 84, fao, roma, pp. 90. fergusson j.e., 1990 the heavy elements: chemistry, environmental impact and healt effects. pergamon press, pp. 614. fondi r., 1972 fauna cromeriana della montagnola senese. paleontographia italica, llxxvvllllll, 1-27. jeanroy e., rajot j.l., pillon p. & herbillon a.j., 1991 differential dissolution of hematite and goethite in dithionite and its implication on soil yellowing. geoderma, 5500, 79-94. kabata pendias a. & pendias h., 1992 trace elements in soils and plants. crc press. macedo j. & bryant r.b., 1987 morphology, mineralogy and genesis of a hydrosequence of oxisols in brazil. soil sci.soc. am.j., 5511, 690-698. mckeague, j.a. & wolynetz, m. s., 1980 backgroun levels of minor and trace elements in some canadian soils. geoderma, 2244, 199-206. nahon d.b., 1991 self-organization in chemical lateritic weathering. geoderma, 5511, 5-13. newhall f., 1972 calcualtion of soil moisture regimes from the climatic record. rev. 4 nimeo-graphed, soil conservation service, usda pp. 17. panizza m., 1985 schemi cronologici del quaternario. geogr. fis. dinam. quat., 88, 44-48. siss (società italiana della scienza del suolo), 1985 metodi normalizzati di analisi del suolo. edagricole, bologna. soil survey staff, 1993 soil survey manual. united states departement of agriculture, hand-book n°18, washington d.c., u.s.a., pp. 437. soil survey staff, 1999 soil taxonomy. usda agricultural handbook 436, washington d.c., u.s.a., pp. 869. wood b.w. & perkins h.f., 1976 a field method for verifying plinthite in southern coastal plain soils. soil sci. 112222, 240-241. 120 ms. ricevuto marzo 2002 ms. received: march 2002 e.a.c. costantini, m. angelone & r. napoli imp. giannandrea aannaalliissii sseeddiimmeennttoollooggiiccaa ddeell ssiinntteemmaa ddii mmoonnttee.. ssiirriiccoo ((ppaarrttee aallttaa ddeellllaa ssuucccceessssiioonnee ddeell bbaacciinnoo ddeellll’’ooffaannttoo)),, aappppeennnniinnoo mmeerriiddiioonnaallee,, bbaassiilliiccaattaa ppaaoolloo ggiiaannnnaannddrreeaa dipartimento di geologia e geofisica, università di bari. riassunto durante il plio-pleistocene l’evoluzione tettonica della catena sudappenninica ha determinato le condizioni per la formazione di bacini satellite documentate da spesse successioni terrigene, in alcuni casi ben esposte. le unità attribuite al bacino dell’ofanto sono state, in recenti lavori, distinte in unità a limiti inconformi (ubsu), che rivelano il forte controllo tettonico sulla sedimentazione. dal più antico al più recente sono stati definiti i supersintemi di aquilonia, ariano irpino – calitri e della fiumara di atella, a loro volta suddivisi in sintemi e subsintemi. queste unità sono ben affioranti in sovrapposizione da ovest verso est. la successione del supersintema della fiumara di atella affiora lungo il settore nod-est del bacino, in una struttura sinclinale successivamente fagliata. il supersintema della fiumara di atella è suddivisa nei sintemi della difesa e di monte sirico, il primo costituito da depositi di transizione, il secondo da depositi continentali. in questa nota si riportano i risultati dell’analisi stratigrafico-sedimentologica dei depositi attribuiti al sintema di monte sirico. tale unità, corrisponde ad una fase di ulteriore deformazione del bacino dell’ofanto che determinò un nuovo depocentro separato dall’avanfossa, confinato a ridosso dei thrust esterni e caratterizzato da sedimentazione fluvio-palustre. i terreni del sintema di monte sirico poggiano, in discordanza, sia sulle unità plioceniche deformate del bacino dell’ofanto, sia sul substrato pre-pliocenico; hanno una età compresa fra il pliocene superiore e il pleistocene inferiore (sono sottostanti ai prodotti vulcanici del monte vulture di età compresa tra 674±7 ka e 132±12 ka). la successione stratigrafica del sintema di monte sirico, spessa alcune centinaia di metri, è costituita da litofacies prevalentemente conglomeratiche lungo i margini del bacino, riferibili a sistemi alluvionali. la dispersione doveva essere di tipo centripeto: negli affioramenti sud-occidentali gli apporti sono dalle unità plioceniche precedentemente deformate e dalle unità mesozoiche delle unità lagonegresi, affioranti a san fele; in quelli nord-orientali l’alimentazione è dalla dorsale appenninica in crescita. nell’area depocentrale del bacino, invece, prevalgono i depositi siltoso-argillosi palustri, con intercalati conglomerati canalizzati. abstract sedimentologic analysis of the monte sirico synthem (uppermost unit of the ofanto basin succession), southern apennine, basilicata the tectonic evolution of the southern apennine chain, during pliocene and pleistocene allowed to develop satellite basins, testified by thick terrigenous succession, locally well exposed. the ofanto basin is pliocene to pleistocene east-west elongated satellite basin, belonging to the outer apennine chain domain. the basin fill is previously subdivided in ubsu. they testify the tectonic control during the sedimentary infill. from the oldest to the youngest three supersynthems are distinguished: aquilonia, ariano irpino calitri and atella. the atella supersyntem is subdivided in the difesa and m. sirico synthems, composed of transitional and continental facies respectively. the m. sirico synthem represent the separation phase of the ofanto basin by foredeep basin; its sedimentation followed the uplift of the outer part of the chain. this unit, upper pliocene-lower pleistocene in age, overlies unconformably both the marine pliocene units of ofanto basin, and pre-pliocene apennine units. it underlies the middle pleistocene m. vulture volcanic units (674±7 ka and 132±12 ka). the m. sirico succession, a few hundred meters thick, consists of coarse-grained alluvial facies, outcropping near the marginal areas; the south-western ones received detritus from pliocenic formation and mesozoic and tertiary units (lagonegrese units of s. fele area). the north-eastern ones received mainly arenaceous tertiary detritus. paleocurrent data suggest a centripetal dispersal. in fact fine-grained marsh deposits with interfingering channelized conglomerates characterize the depocenter area of the basin. parole chiave: appennino meridionale, bacino satellite, supersintema, depositi alluvionali e palustri. keywords: southern apennine chain, satellite basin, supersynthem, alluvial and marsh deposits. il quaternario italian journal of quaternary sciences 1166(2), 2003, 269-277 11.. iinnttrroodduuzziioonnee i lavori di rilevamento geologico eseguiti nel foglio n. 451 “melfi” scala 1:50.000, nell’ambito del progetto carg (cartografia geologica nazionale a scala 1:50.000), hanno fornito la possibilità di studiare un’ampia area della porzione frontale del prisma di accrezione della catena sud-appenninica (fig. 1). in questo lavoro si presentano i risultati delle indagini stratigrafico-sedimentologiche condotte nell’area della valle del fiume ofanto a sud del monte vulture, in corrispondenza della fiumara di atella. i terreni studiati rientrano nella successione attribuita al bacino dell’ofanto (bo), di età plio–pleistocenica (vezzani, 1968), suddivisa in un lavoro recente (giannandrea & schiattarella, 2002) in unità a limiti inconformi. verranno analizzati in particolare i termini stratigraficamente più alti, sottostanti ai prodotti vulcanici del monte vulture, raggruppati nel sintema di monte sirico (sms). questi sono costituiti da terreni di ambiente continentale (alluvionali e lacustri). l’analisi sedimentologica dell’sms, eseguita attraverso lo studio di 1.274 m di sezioni misurate su 11 logs ha permesso di proporre una ricostruzione paleogeografica dell’area, durante il pliocene superiore – pleistocene inferiore. 270 p. giannandrea 22.. iinnqquuaaddrraammeennttoo ggeeoollooggiiccoo il bacino plio-pleistocenico dell’ofanto è un bacino satellite polifasico, interpretato da hippolyte et al., (1992) come bacino di piggy back, (sensu ori & friend, 1984) formato sui thrust esterni dell ’appennino meridionale in evoluzione, con vergenza nei quadranti nord-orientali (hippolyte et al., 1992 ; 1994; patacca & scandone, 2001) (fig. 1). la successione sedimentaria in esso affiorante fa parte dell’unità di ariano irpino (pescatore & ortolani, 1973), il quale comprende la maggior parte dei terreni sedimentati in discordanza sui thrust esterni dell’appennino meridionale. la catena sud-appenninica si struttura, a partire dall’oligo-miocene, a seguito della subduzione verso ovest della placca adriatica (pescatore & ortolani, 1973; mostardini & merlini 1986; casero et al., 1992; patacca & scandone 1989; 2001; lentini et al., 1990; patacca et al., 1990; hippolyte et al., 1994; finetti et al., 1996; prosser et al., 1996; pescatore et al., 1999). in questo settore dell’italia si riconoscono tre elementi tettonici di primo ordine: la catena appenninica, l’avanfossa bradanica e l’avampaese pugliese (d’argenio et al., 1973). numerosi pozzi eseguiti per la ricerca petrolifera hanno messo in evidenza sotto le coltri appenniniche terreni appartenenti all’avanfossa e all’avampaese, coinvolti nel sistema a thrust che disegna una geometria a duplex (finetti et al., 1996; patacca & scandone, 2001), in cui si distingue un elemento pellicolare alloctono composto dalla catena appenninica sovrapposta tettonicamente alla catena apula. il substrato pre-pliocenico del bo è costituito prevalentemente da successioni argillose, calcaree e arenacee di età compresa tra il cretaceo e il miocene superiore appartenenti al le unità lagonegresi (scandone, 1972) ed irpine (cocco et al., 1972). il bo ha una forma allungata in direzione e-w con larghezza media di 7 km e lunghezza 45 km circa. la successione sedimentaria plio-pleistocenica mostra i termini più recenti nel settore orientale del bacino (hippolyte et al.. 1994; giannandrea & schiattarella, 2002) (fig. 2), dove sono sormontati dai prodotti vulcanici del monte vulture di età compresa tra 674±7 ka e 132±12 ka (giannandrea et al., 2002). in tale successione vengono distinte numerose discontinuità (giannandrea & schiattarella, 2002) che consentono di individuare unità separate da limiti di inconformità (ubsu, salvador, 1987; 1994). il quadro stratigrafico che ne deriva (tab. 1) è costituito dai supersintemi di aquilonia, di ariano irpino – calitri e della fiumara di atella. il supersintema di aquilonia è il più antico (pliocene inferiore) ed è costituito da conglomerati, sabbie e subordinatamente argille di fan-delta marino. il supersintema di ariano irpino – calitri (pliocene inferiore – superiore), suddiviso nei sintemi di andretta e di ruvo del monte, è costituito prevalentemente da depositi argillosi di prodelta e piattaforma e subordinatamente, ai margini del bacino, da sabbie e conglomerati (giannandrea & schiattarella, 2002). il supersintema della fiumara di atella è il più recente (pliocene superiore – pleistocene inferiore) ed è ben rappresentato sul bordo orientale del bo. si è formato dopo una intensa attività tettonica, che modificò l’aspetto fisiografico del bacino determinando il sollevamento del settore esterno (orientale) delle coltri appenniniche, attualmente occupato dai prodotti vulcanici del monte vulture (fig. 3). il progressivo isolamento della dorsale esterna causò prima un rapido abbassamento del livello del mare che consentì l’accumulo di una spessa successione di conglomerati, sabbie e argille di fandelta marino (sintema della difesa), poi il progressivo isolamento del bo dall’avanfossa bradanica. è questo il momento in cui si formò il sintema di monte sirico (sms), il quale risulta confinato a ridosso dei thrust esterni, ed è interpretato come un sistema fluvio-palustre riferito ad un bacino endoreico (giannandrea & schiattarella, 2002). nei sedimenti fini, costituiti da sabbie, silt e argille del sintema della difesa si distingue, tra le associazioni a nannofossili calcarei, la zona a discoaster brouweri (mnn18) per la presenza di discoaster spp. e tra le associazioni a foraminiferi planctonici la zona mpl5b (giannandrea & schiattarella, 2002), che consentono di riferire questa unità al pliocene superiore (tab. 1). i rapporti di discontinuità esistenti tra i sintemi di ruvo del monte, della difesa e di monte sirico sono rappresentati e visibili in figura 2 e figura 4. fig. 1 carta geologica schematica del settore orientale dell ’appennino meridionale e ubicazione del bacino dell’ofanto. schematic geological map of the southern apennines, and location of ofanto basin. 271analisi sedimentologica del sintema ... fig. 2 carta geologica schematica del settore orientale del bacino dell’ofanto schematic geological map of the eastern part of the ofanto basin. fig. 3 – sezione geologica schematica del bacino del sintema di monte sirico (vedi figura 2 per ubicazione). gli spessori e la superficie inferiore del sintema sono ricavate dalle geometrie dei corpi affioranti studiati. schematic cross-section of monte sirico synthem (location in fig. 2). the the lower surface of monte sirico synthem and the overall thickness are speculative, obtained from geometries and facies relationships. 272 33.. ffaacciieess sseeddiimmeennttaarriiee l’area di affioranmento del sms, occupa approssimativamente una superficie larga 9 km e lunga circa 16 km. si configura sul margine orientale del bo (fig. 2) alla fine del pliocene superiore, in seguito al sollevamento della parte esterna della catena sudappenninica. inferiormente il sintema poggia, con un rapporto di discordanza angolare ed erosivo sui sintemi della difesa e di ruvo del monte e sul bordo orientale (fig. 2), a sud della fiumara di atella, sul substrato pre-pliocenico. la sua storia deposizionale probabilmente prosegue fino al pleistocene inferiore, poiché i suoi sedimenti risultano ricoperti dai prodotti vulcanici del monte vulture di età compresa tra 674±7 ka e 132±12 ka, giannandrea et al., (2002). l’area di affioramento del sms è coperta da intensa vegetazione e viene attraversata in direzione se-no dalla fiumara di atella. tuttavia è stato possibile descrivere la parte alta dell’unità per uno spessore di circa 250 m, mentre lo spessore complessivo, di circa 550 m, è stato ricavato dall’interpretazione della sezione geologica di figura 3. sono stati descritti complessivamente 1.274 m di sezioni rilevate in 11 logs (fig. 5 e fig. 6). i maggiori affioramenti sono visibili sul versante sud-occidentale del bacino, in corrispondenza dei fronti di ruvo del monte e lungo alcune incisioni vallive. in tabella 2 sono riportati i codici delle litofacies descritte e le relative interpretazioni secondo i criteri di miall (1992), ridgway & decelles (1993) e bridge (1993). tab. 1 schema biostratigrafico del bacino dell’ofanto. analisi integrata dei bio-orizzonti a nannofossili calcarei e foraminiferi planctonici del pliocene. (in giannandrea & schiattarella, 2002) integrated biostratigraphic scheme of the ofanto basin, based on the analysis of pliocene nannofauna and planktonic foraminifera (in giannandrea & schiattarella, 2002) codice litofacies processo deposizionale gcm ghiaia clasto-sostenuta, massiva, flusso ad alta energia, incanalato con o senza ciottoli embriciati (colata di detrito) gch ghiaia clasto-sostenuta a stratificazione flusso ad alta energia non incanalato orizzontale, con o senza ciottoli embriciati (barra longitudinale, lobi setaccio) gct ghiaia clasto-sostenuta a stratificazione flusso ghiaioso incanalato (riempimento incrociata concava di canali minori) gcp ghiaia clasto-sostenuta a stratificazione accrescimento laterale di barre ghiaiose planare obliqua (barra longitudinale) sm sabbia massiva flussi sabbiosi di alta energia, disorganizzati st sabbia da media a molto fine a stratificazione riempimento di docce di erosione, incrociata concava migrazione di dune sh sabbia da molto fine a grossolana a letti planari di regime di flusso superiore, laminazione orizzontale sheet flood fsl sabbia, silt, fango a laminazione sottile, piana flusso di tracimazione o di piena calante e a ripples, con resti vegetali e tracce di radici fmm fango massivo decantazione in paludi o aree di inondazione tab. 2 – classificazione delle litofacies e loro interpretazione (miall, 1992; ridgway & decelles, 1993; bridge, 1993). litofacies classif ication and interpretat ion (miall, 1992; ridgway & decelles, 1993; bridge, 1993). p. giannandrea 273 l’analisi di facies condotta nelle sezioni sedimentologiche riportate in figura 5 e in figura 6 ha consentito di raccogliere numerose informazioni sulla distribuzione verticale ed areale delle litofacies, di dedurre le principali associazioni di facies, e di risalire alle aree di alimentazione e al modello generale di dispersione degli apporti detritici. conglomerati clasto-sostenuti con intercalazioni di sabbia, silt e argilla (a) questa associazione presente ai margini del bacino del sms è la più diffusa ed è osservabile in tutte le sezioni rilevate (fig. 5 e fig.6). é costituita prevalentemente da conglomerati clasto-sostenuti, con stratificazione incrociata concava (gct) e da conglomerati scarsamente organizzati (gcm). la matrice è generalmente costituita da sabbia media. i ciottoli sono ben arrotondati, prevalentemente tabulari (60%) e in minore percentuale sferici (30%) e a lama (10%). il diametro medio dei ciottoli si aggira normalmente intorno ai 10÷15 cm, ma sono anche presenti isolati ciottoli di 50÷60 cm. ciottoli embriciati e pebble clusters sono frequentemente visibili. internamente sono presenti sotti l i intercalazioni di sabbie da medie a grossolane a stratificazione incrociata (st). a più altezze stratigrafiche sono intercalate lenti spesse qualche metro e larghe da pochi metri a 10÷20 m di sabbia, si l t e fango a laminazione sottile, con resti vegetali (fsl) e strati spessi qualche metro di conglomerato clastosostenuto, con moderato a poco grado di selezionamento, stratificazione planare obliqua con ciottoli embriciati e pebble clusters (gcp). le lamine della litofacies fsl possono essere piano-parallele, leggermente ondulate e modellate da ripples. lungo il margine sudoccidentale del bacino, in località fronti di ruvo del monte (logs a t 1 , 2 , 3 , 4 , 5 , 6 b g , ru31bg, ru9bg, ru10bg e ru32bg di fig. 5 e fig. 6), prevalgono i conglomerati clasto-sostenuti massivi o con stratificazione interna grossolana e basso grado di selezione (gcm) a cui si intercalano strati metrici di conglomerato clasto sostenuto con stratificazione incrociata sia concava (gct) che piana (gcp) e stratificazione orizzontale (gch). generalmente queste facies sono organizzate in sequenze fining upward (fu) spesse da pochi metri a 15÷20 m. la facies gch è dominante nei log at1,2,3,4,5,6bg. l’associazione di facies è riconducibile a una piana alluvionale con corsi d’acqua braided dominata da sedimentazione ghiaiosa e flussi di alta energia (gcm) che determinavano frequenti inondazioni della piana, per la frequente presenza delle litofacies gcm, sm e fsl. spesso si sono distinte sequenze metriche, con alla base conglomerati massivi o lag deposits e a tetto la litofacies gcp. queste sequenze possono essere riferite all’accrescimento laterale di barre longitudinali (nemec & postma, 1993; miall 1996). lungo il versante sudoccidentale del bacino la sedimentazione ghiaiosa è caratterizzata da sequenze deposizionali in cui prevalgono flussi di alta energia dominati, alla base, da colate di detrito incanalato, (ridgway & decelles, 1993), tendenti, verso l’alto, a flussi non incanalati (barra longitudinale e lobi setaccio miall, 1996) riconducibili ad un’area relativamente prossimale di conoide alluvionale. fig. 4 – profilo schematico e foto panoramiche del settore sud-occidentale del sintema di monte sirico (vedi figura 2 per ubicazione). sono ben visibili le discontinuità che separano il sintema di monte sirico da quelli della difesa e di ruvo del monte. schematic cross-section and panoramic vews (location fig. 2) of monte sirico synthem in the southwestern sector. unconformites are outlined in the drawing. analisi sedimentologica del sintema ... 274 sabbie con intercalazioni di conglomerati (b) viene descritta nei logs ru32bg, ru33bg, e at9bg (fig. 5 e fig. 6) ed è costituita da sabbie siltose massive in strati spessi 1÷2 m (sm) e da sabbie da grossolane a fini con stratificazione incrociata concava (st) e piano parallelo (sh). le superfici di separazione degli strati sabbiosi (sm) sono evidenziate dalla presenza di sottili livelli di silt laminati. intercalate alle facies sabbiose sono osservabili lenti di conglomerati canalizzati, clasto-sostenuti, con stratificazione incrociata (gct e gcp). l’embriciamento dei ciottoli è ben visibile. le lenti di conglomerato sono di spessore e larghezza molto variabile da alcune decine di centimetri a qualche metro. tale associazione viene attribuita ad un’area relativamente distale di piana a corsi d’acqua braided. sabbie, silt e argilla con inercalazioni di conglomerato (c) l’associazione, osservabile nel settore orientale del bacino (logs at7bg, at1,2,3,4,5,6bg e parte centrale del log at8bg) (fig. 5), è dominata dalla presenza di fig. 5 – profilo verticale, delle sezioni ru31bg-ru34bg e ru37bg del sintema di monte sirico e ubicazione dell’area studiata. sono visibili la distribuzione verticale delle associazioni di facies (a e b) e la dispersione delle paleocorrenti. per le sigle delle facies vedi tab. 2 vertical logs ru31bg-ru34bg and ru37bg of the monte sirico synthem and location map of the logs studied. the picture shows vertical facies associations distributions (a and b), and palaeocurrents dispersal. for facies classification see tab. 2. p. giannandrea sabbie, silt e fango sottilmente laminati (fsl) e da argille massive con resti vegetali e bioturbazioni da radici (fm); le due litofacies si presentano in strati metrici e in alternanza. intercalati si osservano spesso conglomerati canalizzati massivi (gcm). i canali hanno uno spessore dell’ordine del metro e larghezza di alcuni metri. a circa 15 m dalla base del log at7bg sono visibili alternate alla facies a grana fine canali sovraimposti e colmati da conglomerati clasto-sostenuti, con stratificazione incrociata (gct e gcp). l’associazione di facies può essere attribuita ad una piana alluvionale distale caratterizzata da estese paludi e interessata da frequenti eventi di piena, durante i quali sedimentano le facies conglomeratiche massive (gcm). a luoghi sono riconoscibili facies riferibili a canali tipo multistorey a sedimentazione conglomeratica. 44.. aannaalliissii ddeellllee ppaalleeooccoorrrreennttii ee rriiccoossttrruuzziioonneeppaalleeooggeeooggrraaffiiccaa le paleocorrenti ricavate dall’embriciatura dei ciottoli e dalla stratificazione incrociata delle facies conglomeratiche (fig. 5 e fig. 6), sono state inserite in diagrammi di dispersione e riportate in una carta schematica dell’area di affioramento del sms (fig. 7). le aree di provenienza possono essere collocate nei quadranti meridionale, occidentale e settentrionale. il settore depocentrale del bacino, potrebbe essere indicato dalle sezioni at7bg e at8bg. tale dato è confermato anche dall’analisi petrografica dei ciottoli e dai rapporti geometrici tra le associazioni di facies (fig. 3). nelle sezione at1,2,3,4,5,6bg, ru10bg e ru9bg prevalgono i ciottoli arenacei erosi dalle unità plioceniche e 275 fig. 6 – profilo verticale, delle sezioni at1bg-at9bg, ru9bg e ru10bg del sintema di monte sirico. sono visibili la distribuzione verticale delle associazioni di facies (a, b e c) e la dispersione delle paleocorrenti. per l’ubicazione delle sezioni vedi fig. 5, per le sigle delle facies vedi tab. 2 vertical logs at1bg-at9bg, ru9bg and ru10bg of the monte sirico synthem. the picture showing vertical facies associations distributions (a, b and c), and palaeocurrents dispersal. for logs location see fig. 5, for facies classification see tab. 2. analisi sedimentologica del sintema ... quelli calcareo-marnosi, calcarei micritici e calcarei con selce e silicei, provenienti dalle unità lagonegresi (serie calcareo-silico-marnosa della facies di san fele; scandone, 1972). in minore percentuale sono presenti ciottoli calcarenitici ed arenacei. nelle sezioni ru33bg, ru32bg, ru31bg, ru34bg e ru37bg prevalgono, oltre ai ciottoli arenacei provenienti dalle unità plioceniche, anche quelli calcarei, calcarenitici e calcareo-marnosi; sono praticamente assenti i diaspri e i calcari con selce. infine nella sezione at8bg sono presenti: arenarie dei flysch miocenici affioranti a nord dell’affioramento del sms, calcari neri, calcareniti e calcari marnosi. l’analisi delle sezioni misurate e della distribuzione delle paleocorrenti, quindi, consente di tentare una ricostruzione del paleopaesaggio durante il pliocene superiore pleistocene inferiore (fig. 8). la facies dominante è quella riconducibile a depositi alluvionali tipo braided. pertanto il modello ricostruito prevede un’ampia piana alluvionale orientata in direzione no-se, con deflusso generale dei canali verso i quadranti sud-orientali in direzione di un’area paludosa. apporti laterali dovevano provenire sia dai quadranti sud-occidentali che da quelli nord-orientali. gli apporti meridionali erano alimentati da torrenti, che attraversavano i terreni pliocenici meno elevati, provenienti dall’alto di san fele. le aree di alimentazione nord-orientali, probabilmente più vicine al depocentro, dovevano alimentare un’area pedemontana caratterizzata da tipiche conoidi alluvionali. la vasta area paludosa posizionata sul margine orientale del bacino (fig. 8) era caratterizzata dalla sedimentazione di depositi fini dell’associazione c, dominate da depositi di piene improvvise, da facies di tracimazione e in minore percentuale da depositi di decantazione e da conglomerati canalizzati (sezioni at1,2,3,4,5,6bg e at7gb). tali associazioni sono indicative di un’area soggetta a frequenti inondazioni e fluttuazioni del livello delle acque. probabilmente si alternavano periodi di piena, con ampie aree paludose inondate, a periodi di minor apporto durante i quali le aree umide si restringevano notevolmente. bbiibblliiooggrraaffiiaa bridge j.s., (1993) – description and interpretation of f luvial deposits: a crit ical perspective. sedimentology, 4400, 801-810. casero p., roure f., endignoux l., moretti i., muller c., sage l., & vially r. (1992) – neogene geodynamic evolution of the southern apennines. mem. soc.geol. it. 4411, 109-120. cocco e., cravero e., ortolani f., pescatore t., russo m., sgrosso i. & torre m., (1972) – les facies sedimentaires du bassin irpinien (ital ie meridionale). att. acc. pontaniana, napoli, 2211, 307-322. d’argenio b., pescatore t. & scandone p. (1973) – schema geologico dell’appennino meridionale (campania e lucania). acc. naz. lincei, quad., 118833: 49-72. finetti i., lentini f., carbone s. catalano & del ben a., (1996) – il sistema appenninico meridionale – arco calabro – sici l ia nel mediterraneo centrale:studio geologico-geofisico. boll. soc. geol. it., 111155, 529-559 giannandrea p., la volpe l., principe c. & schiattarella m., (2002) carta geologica del monte vulture alla scala 1:25.000. 81a riunione estiva della società geologica italiana, torino 10-12 settembre 2002 (1a bozza di stampa). giannandrea p. & schiattarella m. (2002) – stratigrafia delle successioni sedimentarie del foglio 451 “melfi”. in: la volpe l. (eds.): “note illustrative della carta geologica d’italia alla scala 1:50.000, foglio 451 melfi” pres. del cons. dei min., 276 fig. 7 – carta dei diagrammi di dispersione delle paleocorrenti del sintema di monte sirico, mostra la provenienza degli apporti dai quadranti meridionali, occidentali e settentrionali e la convergenza degli assi principali di alimentazione verso l’area depocentrale (orientale). palaeocurrents dispersal diagrams map of the monte sirico synthem, showing southern, western and northern source areas. moreover the eastward directed palaeoflow is inferred. fig. 8 – tentativo di ricostruzione paleogeografica del sistema alluvionale del sms. palaeogeographic reconstruction of the alluvial plain synthem of sms. p. giannandrea dip.serv. tec. naz., serv. geol. naz., cnr. in stampa. hippolyte j.c., angelier j. & roure f., (1992) – paleostress analyses and fold-and-thrust belt kinematics in the southern apennines. in: f. roure, n ellouz, v.s. shein & i.i. skvortsov (eds.): “geodinamic evolution of sedimentary basins”. international symposium, 157-169. hippolyte j.c., angelier j., roure f. e casero p., (1994) – piggyback basin development and thrust belt evoution: structural and palaeostress analyses of plio-quaternary basins in the southern apennines. journ. struct.geol., 1166: 159-173. lentini f., carbone s., catalano s. & monaco c., (1990) – tettonica a thrust neogenica nella catena appenninica-maghrebide: esempi dalla lucania e dalla sicilia. studi geologici camerti, volume speciale, 19-26. miall a.d., (1992) – alluvial deposits. in: walker r.g.& james m.p. (eds):facies models: response to sea-level change. geological association of canada, 119-142. miall a.d., (1996) – the geology of fluvial deposits: sedimentary facies, basin analysis and petroleum geology. springer verlag: 502 pp. mostardini f. & merlini s. (1986) appennino centro meridionale. sezioni geologiche e proposta di modello strutturale. mem. soc. geol. it., 3355: 177202. nemec w. & postma g., (1993) – quaternary alluvial fans in southwestern crete: sdimentation processes and geomorphic evolution. spec. publs int. ass. sediment., 1177, 235-276. ori g. & friendp.f., (1984) – sedimentary basin formed and carried piggy-back on active thrust sheets. geology, 1122, 475-478. patacca e., sartori r., & scandone p., (1990) – tyrrhenian basin and apenninic arc: kinematic relations since late tortonian times. mem. soc. geol. it., 4455:: 425-451. patacca e. & scandone p., (1989) – post tortonian mountain building in the appennines. the role of the passive sinking of a relic lithospheric slab. in boriano a., bonafede m., piccardo g.b. & vai g.b. (eds): the lithosphere in italy. advances in earth science research. i. nat. comm. int. lith. progr., mid-term conf. (rome, 5-6 may 1987), atti conv. lincei, 8800, 157-176 patacca e. & scandone p. (2001) – late thrust propagation and sedimentary response in the the thrustbelt-foredeep system of the southern apennines (pliocene-pleistocene). in: vai g.b. & martini i.p. eds., anatomy of an orogen:the apennines and adjacent mediterranean basins. 401-440. kluwer accademic publishers pescatore t. & ortolani f. (1973) – schema tttonico dell’appennino campano-lucano. boll. soc. geol. it., 9922: 453-472. pescatore t., renda p., schiattarella m. & tramutoli m. (1999) stratigraphic and structural relationships between meso-cenozoic lagonegro basin and coeval carbonate platforms in southern apennines, italy. tectonophysics, 331155: 269-286. prosser g., schiattarella m., tramutoli m., doglioni c., harabaglia p. & bigozzi a. (1996) una sezione rappresentativa dell'appennino meridionale. riassunti conferenza sulla ricerca scientifica in basilicata, università della basilicata regione basilicata, febbraio 1996, 28. ridgway k.d. & decelles p.g., (1993) – stream-dominated alluvial fan and lacustrine depositional systems in cenozoic strike-slip basins, denali fault system, yukon territory, canada. sedimentology, 4400,, 645-666. salvador a. (1987) – unconformity-bounded stratigraphic units. geological society american bulletin, 9988: 232-237. salvador a. (ed) (1994) – international stratigraphic guide. international union of geological sciences, trondheim, norway, and geological society of america, boulder, 214 pp. scandone p. (1972) studi di geologia lucana: carta dei terreni della serie calcareo-silico-marnosa e note illustrative. boll. soc. natur. in napoli, 8811:: 225-300. vezzani l., (1968) – stratigrafia die terreni infra-mesopliocenici di ruvo del monte (potenza). boll. acc. gioenia sc. nat. catania, 99:: 3-41. 277 ms. ricevuto il 13 maggio 2003 testo definitivo ricevuto il 18 novembre 2003 ms. received: may 13, 2003 final text received: november 18, 2003 analisi sedimentologica del sintema ... imp.galli i terremoti del gennaio 1117. ipotesi di un epicentro nel cremonese paolo galli dipartimento della protezione civile u. servizio sismico nazionale via vitorchiano 4, 00189 roma cnr istituto di geologia ambientale e geoingegneria via bolognola 7 00138 roma paolo.galli@protezionecivile.it riassunto: p. galli, i terremoti del gennaio 1117. ipotesi di un epicentro del cremonese. (it issn 0394-3356, 2005). il terremoto del 1117 può essere considerato l’evento distruttivo di riferimento per la storia sismica di una vasta parte della pianura padana. tuttavia, a causa della lontananza temporale delle fonti e della oggettiva complessità dell’evento (terremoto multiplo), la sua attuale ubicazione epicentrale (verona) non appare rappresentativa della distribuzione degli effetti. sulla base del riesame completo delle fonti primarie conosciute e di quelle poche non note nei precedenti studi, nonché da evidenze di carattere archeosismologico, viene proposto un quadro indiziario degli effetti che, confrontato con le possibili strutture sismogenetiche sepolte della pianura padana, permette di ipotizzare l’esistenza di un secondo epicentro in area basso-padana, verosimilmente ubicato nel cremonese. abstract: p. galli, the earthquakes of january 1117 in northern italy. hypothesis for an epicentre in the southern po plain (cremona), (it issn 0394-3356, 2005). the 1117 earthquake is probably the strongest event which occurred in northern italy during the historical period. although its eco, and perhaps its effects were felt in a vast area of central and southern europe (i.e., from reims to montecassino) its epicenter is still uncertain and strongly debated, and it is presently placed near verona by the italian seismic catalogue (gruppo di lavoro cpti, 1999). actually, we know that it was a long seismic sequence, characterized by more than one mainshock, with damage areas in the adige valley (south of trento), in the verona territory, and in the area nw and se of cremona (enel, 1986; magri e molin, 1986; boschi et al., 1995; galadini et al., 2001b). damage were also reported in a village near august (germany) and pisa, being related to earthquakes which occurred by chance in the same days, but without any possible seismotectonic significance with respect to the earthquake cited universally by the historical source as happened in “longobardia” (the land of northern italy ruled by longobards during middle ages). in northern italy, the damaged localities explicitly quoted by the local synchronous sources (excluding those mentioned repetitively in transalpine chronicles: verona …. similiter parma et in venetia) are only verona, ronco all’adige (a small village se to verona) and cremona, while three memorial stones witness effects in padua, costozza and nonantola (villages near padua and modena, respectively). a strong effect is also recorded in milan and its province. from the seismotectonic point of view, galadini et al. (2002) placed the source of the 1117 earthquake on the so-called thienebassano thrust, which is located between 110-130 km away from cremona, along the southalpine front. as for the effect in cremona, new archaeoseismic data deduced from archaeological excavation carried out in the past years in the cathedral confirm and enrich the frame depicted by the synchronous sources (collapse of the new (?) church under construction during the 1117 earthquake, burying of the remains of the patron saint himerius under the ruins, and their recovery only twelve years later). moreover, this data seems to demonstrate that the current cathedral was entirely rebuilt following the earthquake, none of the wall or structures in fieri during the 1117 having been saved after the collapse. the original design of the cathedral started in 1107 was changed, and only few sculptures and architectural elements in situ before the earthquake were re-employed afterwards. based on the above, it is very difficult that damage and collapses in places located up to 100 km away from each other may be accounted for only one seismic source. considering the existence of more than one mainshock between 2-3-4 january (as reported by the historical sources), the event which hit southern lombardy and neighboring places before 5 p.m. (local time) of january 3 could be related to a local seismogenic structure, and not to the fault which caused damage in the same hours/days in the verona-padua area (i.e., the mentioned thiene-bassano thrust). this structure could be identified with one of the thrusts existing along the buried front of the apennine chain which show traces of recent tectonic activity, as the one affecting the buried piadena anticline, just under the province of cremona. parole chiave: archeosismologia, sismicità, tettonica attiva, italia settentrionale. keywords: archaeoseismology, seismicity, active tectonics, northern italy. il quaternario italian journal of quaternary sciences 18(2), 2005 87-100 1. introduzione il terremoto del gennaio 1117 è, senz’altro, uno dei più forti e poco compresi eventi sismici dell’italia settentrionale. mentre la sua eco, ma forse i suoi stessi effetti, si sono risentiti in una vasta area dell’europa centro meridionale, da reims a montecassino, la sua area epicentrale non è ancora univocamente riconosciuta, anche se il suo epicentro è posto dai cataloghi sismici italiani nei pressi di verona (p.e., gruppo di lavoro cpti, 1999). in realtà, sappiamo che si trattò di una lunga e complessa sequenza sismica, caratterizzata, presumibilmente, da più mainshocks, con probabili aree di danno nella valle tridentina (la val d’adige da nord di trento a nord di verona), nel veronese e nell’area tra cremona e nonantola (enel, 1986; magri e molin, 1986; boschi et al., 1995; galadini et al., 2001b). danni sono anche segnalati in un villaggio presso augusta (heirenbuch, germania) ed a pisa1, certamente relativi 1 la notizia è in guido pisano, biblioteca apostolica vaticana, cod. vat. lat. n. 11564, c. 91. (vedi scalia, 1963). 88 p. galli ad eventi sismici casualmente avvenuti negli stessi giorni, ma che nulla hanno a che fare, dal punto di vista sismotettonico, col terremoto in longobardia citato universalmente dalle fonti. a nord di pisa, le località italiane danneggiate citate esplicitamente dalle fonti sincrone locali, a parte quelle ricorrenti in modo litanico nelle cronache transalpine (verona … similiter in parma et in venetia), sono solo verona (annales veronenses2; donazione di decima3, ed altri: cfr. in enel, 1986), ronco all’adige4 (vedi kehr, 1961) e cremona (vedi oltre), mentre tre lapidi attesterebbero danni a padova (dispersa5), a nonantola (di controversa lettura6) e/o un forte risentimento a costozza7 (fig. 1a). per milano, fonti coeve attestano un forte risentimento in città e nella provincia (beroldus, xii sec.). sulla cronologia delle diverse scosse non ci sono certezze, sebbene le notizie convergono quasi tutte sul 2-3-4 gennaio (molte fonti parlano dell’octava sancti johannis evangelistae8 oppure iii nonas ianuarius9). per quanto attiene l’orario, alcune fonti recitano “una volta di giorno ed una di notte”, altre “due volte tra giorno e notte”; oppure “al canto del gallo ed all’ora nona”, “dopo il terzo canto del gallo e quasi alla decima ora”, “prima del tramonto”, “all’ora vespertina”, “dopo i vespri, a cena”. in particolare, le fonti di area lombarda (cremona e milano), parrebbero collocare il terremoto (cioè la scossa principale “locale”) mercoledì 3 gennaio, all’ora del vespero, cioè prima delle 17 ora locale10, mentre a pisa l’evento locale11 è riferito a giovedì 4 gennaio alle 16:15 (15:15 gmt; hora xi) ed una forte scossa, forse il risentimento di un forte evento lontano, nella notte precedente. nel complesso, è probabile che essendo le aree di principale danneggiamento più d’una – e, riassumendole, una presso augusta, una nell’area trentinoveneta, una in quella lombardo-emiliana ed una in quella pisana le diverse cronache di regioni distanti12 – attingendo anche l’una dall’altra abbiano confuso e/o unificato gli orari delle eventuali diverse scosse. di sicuro l’impatto del terremoto fu talmente forte che l’evento rimase nella memoria delle persone per molti anni, almeno in tutta l’area lombardo-veneta-emiliana. lo testimoniano numerosi documenti notarili nei quali il terremoto è usato come termine cronologico di riferimento per fatti avvenuti a distanza anche di settant’anni13. in questo lavoro, a seguito della disamina delle fonti primarie relative a cremona (e subordinatamente, ad altre città emiliane) ed unitamente alla presentazione di indizi di carattere archeosismico raccolti nell’area della sua cattedrale, viene delineato un quadro di danneggiamento centrato nella bassa padana orientale. il confronto poi con le possibili strutture sismogenetiche desumibili dalla letteratura ha permesso di formulare nuove ipotesi concernenti l’epicentro di uno dei mainshock della sequenza del 1117. non si nasconde il carattere in parte speculativo e, perché no, provocativo di questa nota; d'altronde, essa è stata anche concepita nella vaghezza che certi temi di ricerca, quale l’analisi in chiave archeosismologica degli edifici medievali padani, possano concorrere in futuro ad un quadro più convincente di questo terremoto. 2. il terremoto a cremona 2.1 le fonti. come detto, cremona è una delle poche località per le quali ci siano giunte notizie contemporanee certe relative al danneggiamento causato dal terremoto. la più sicura è quella contenuta nei cronica del cremonese sicardus (vescovo tra il 1185 e il 1215) che, per la vicinanza di luogo e di tempo, sicuramente potè attingere a notizie di prima mano. essa ci dice che nell’ “anno domini millesimo cxvi [per 1117], terre motus magnus in ianuario fuit, 2 vi si ricorda in data 12 gennaio 1117 la consacrazione della chiesa della santa trinità che, evidentemente, non era stata danneggiata e, a seguire, quasi en passant, “hoc anno multes turres et innumerabilia edificia propter terremotum per longobardiam et alias terras corruerunt …. [a] terremotus maximus fuit, in quo etiam magnam pars arene cecidit”. 3 si riporta la rinuncia da parte del visconte ridolfo ad una decima in data 24 gennaio 1117 “usque ad diem quo civitas verona terremotu tam grandi exterminata est”. 4 la chiesa di s. maria a “runco” è detta “terrae motus eversa” nell’anno 1117. 5 ricordata da scardeone (1560) nella chiesa di santa giustina: “anno domini mcxxiiii indictione ii / arte magistrali macilli me struxit ab imo / clerus: terrae primo motus subvertit ab imo”. 6 l’iscrizione, scolpita sull’architrave del portale in facciata, adattandosi agli spazi scanditi dalla frattura che attraversa la pietra, recita: “silvestri celsi ceciderunt culmina templi mille redemptoris lapsis vertigine solis / anni centenis septem nec non quoque denis quod refici magnos cepit post quattuor annos”. il senso, potrebbe essere che “negli anni 1117 del redentore caddero i tetti del tempio dell’eccelso silvestro, squassato il “terreno per il moto vorticoso”, e parimenti prese ad essere rifatto dopo quattro anni”. oppure, come in enel (1986), che “le cime del grande tempio di silvestro caddero dopo che le “rivoluzioni del sole” nel 1117 avevano segnato molti anni da cristo. la ricostruzione fu iniziata dopo quattro anni”. in questa seconda lettura, il terremoto non viene evocato come causa del crollo. 7 alla base del campanile di san mauro: “t[empore] teremoti mcxvii / mccxxiii t[em]p[ore] teremoti / mcccxliii teremoti”. 8 otto giorni dal 27 dicembre, san giovanni evangelista e cioè il 3 gennaio. 9 tre giorni dalle nonae, invero dal 5 e quindi il 3 gennaio; altre fonti riportano iv nonas, cioè il 2 gennaio od il giorno prima delle nonae, cioè 4 gennaio. 10 il tramonto del sole i primi di gennaio in lombardia è verso le 16.50. in gruppo di lavoro cpti, 1999, il terremoto è riportato, invece, alle 13.00 gmt. 11 che, come detto, nulla può avere a che fare col terremoto in longobardia. 12 se ne veda una valida rappresentazione in enel, 1986. 13 oltre ai documenti relativi al veronese ed al piacentino riportati in enel (1986) ed a quelli noti per l’area tra mantova e rovigo (in galadini et al., 2001) se ne sono rintracciati diversi altri per l’area bresciana sul tenore di: “quando fuit terremotus”, “de teramotu maiori”, “a tempore terremotus”, “per terremotum”, “ante terremotum”, tutti datati tra il 1163 ed il 1189 (vedi codice diplomatico bresciano, 1, ed. di e. barbieri, e. cau in: codice diplomatico della lombardia medievale). 89i terremoti del gennaio 1117 ... fig. 1 a, località danneggiate dal terremoto del 1117 così come desunte l im i ta tamente alle fonti primarie (area italiana settentrionale). b, quadro sis m o t e t t o n i c o della pianura padana e zone limitrofe. le strutture in grassetto sono relative al dominio alpino. sono stati evidenziati i soli box sismogenetici (proiezione in superficie del piano di faglia) dei terremoti del 1117 e 1695 sul fronte sudalpino (da galadini et al., 2002); quello in prossimità di cremona è ipotizzato in questo lavoro. i paleoterremoti sono tratti da galadini e galli (1999) e da galadini et al. (2001a). a, localities damaged by the 1117 earthquake as deduced from primary historical sources. b, seismotectonic sketch of the po plain (bold lines are alpine t h r u s t s ) . seismogenetic box (surface projection of the fault plane) of the 1117 and 1695 earthquakes after galadini et al . (2002); the one near cremona has been hypothesized in this paper. paleoearthquakes after galadini and galli (1999) and galadini et al (2001a). 90 propter quem maior cremonensis ecclesia corruit, et corpus confessoris ymerii diu latuit sub ruina…lotharii temporibus obertus cremonae fuit episcopus, qui sancti himerii, quod diu latuerat, corpus invenit, & anno domini mcxxix in scrineo serrato recondidit”. altra notizia è contenuta nella cronichella cremonese, fonte del xiii secolo, che dice per l’anno 1116, invero 1117: “tertis nonas januarius terremotus magnus fuit per quem major cremonae ecclesiae corruit, et corpus sci himerij diu labuit [sic] sub ruina”. quindi, per l’anno 1129: “obertus fuit episc. cremonae qui corpus sci himeriis quod diu labuit [sic] propter ruinam invenit et in scrineo ferrato [sic] recondidit”. ancora, sempre del xiii secolo, il chronicon cremonense: “quando fuit terraemotus, mcxvi [per 1117] in octava sancti johannis evangelistae hora vesperum … mcxxix … et eodem anno inventum fuit corpus sancti himerii in mense madii”. infine, alberto di bezano, abate di san lorenzo a cremona, nel xiv secolo: “anno domini mcxvi [per 1117], indictione x, iii nonarum ian. terremotus magnus fuit, propter quem maior cremonensis ecclesia corruit, et corpus confessoris ymerii diu latuit sub ruina”. queste notizie, più o meno ripetendosi l’un l’altra, ci dicono che in occasione del terremoto, avvenuto il 3 gennaio prima delle 17.00 (ora locale), la cattedrale di cremona crollò, ed il corpo del santo protettore imerio rimase a lungo sotto le macerie, sino a quando fu ritrovato nel maggio 1129 ed il vescovo oberto lo pose al sicuro in uno scrigno. 2.2 indizi archeosismici in cattedrale. assumendo dunque che la cattedrale, in toto od in parte, crollò, è possibile oggi trovarne dei riscontri oggettivi ovvero degli indizi archeosismici in situ? ma innanzitutto, quale cattedrale crollò? (fig. 2). notizie di una “vetus ecclesia maior sancte marie de cremona”, forse danneggiata insieme al resto della città al termine dell’assedio postole da agilulfo nell’agosto del 603 (“civitatem cremonensem…..ad solum usque destruxit”, paolo diacono, viii sec.), contrapposta ad una “sancte marie novae de cremona”, si hanno in documenti della metà del vii secolo (codice diplomatico longobardo14). tracce della nuova (o restaurata) chiesa, cointestata a santa maria ed a santo stefano, si hanno finalmente in un diploma di lotario i, datato 84115, che richiama precedenti diplomi dei tempi di carlo magno (governo 774-814) e ludovico pio (governo 814840). la cointestazione si spiega col fatto che, probabilmente, si trattava di una “cattedrale doppia” (mirabella roberti, 1979), le cui due aule16 erano separate dal battistero paleocristiano di recente riconosciuto negli scavi della cripta17 (vedi fig. 3). sino a prova (documentale) contraria, la costruzione di una nuova cattedrale di cremona fu intrapresa sotto il pontificato di pasquale ii nel 1107, con l’ausilio di maestranze in parte fuoriuscite dal cantiere della cattedrale di modena (il cui altare era stato consacrato l’anno precedente), in un’area, quella precedente, occupata sin dall’antichità da un grande edificio residenziale di epoca imperiale (30-40 d.c.18), e sulle rasature di preesistenti edifici di culto cristiano. questi ultimi si datano tra il iv ed il v secolo19 ed al vi-viii secolo20. la data di fondazione della cattedrale (110721) è fig. 2 a sinistra, immagine della cattedrale di cremona nella matrice di un sigillo del comune del 1249 (proprietà dell’autore). la facciata romanica è quella della ricostruzione successiva al terremoto del 1117, con ulteriori modifiche degli inizi del ‘200 (vedi in gandolfo, 2001), mentre a destra è la veduta dell’odierna facciata, dopo i rimaneggiamenti basso medievali e rinascimentali. left, the cremona cathedral on a seal matrix dated 1249. the romanesque facade is due to the rebuilding after the 1117 earthquake, modified at the beginning of the 13th cent. (gandolfo, 2001). right, present facade, after the low-middle age and renaissance “restyling”. 14 ma alcuni di questi codici, ed in particolare il complesso di cremona, sono ritenuti in parte contraffatti dal canonico dragoni tra ‘700 e ‘800. 15 praeceptum lotharii i imperatoris, 841 maggio 12, quincy; vedi codice di sicardo, xii-xiii sec., ed. di v. leoni in: codice diplomatico della lombardia medievale, viii-xii sec. 16 mirabella roberti (1979) credè di identificare una delle aule proprio con i lacerti musivi di iv-v secolo nel cortile del torrazzo e con brani di muratura paralleli al muro nord del duomo romanico. l’altra aula potrebbe identificarsi con lacerti murari e di pavimento in cocciopesto da poco scavati nel locale caldaie del duomo; l. passi pitcher, sopr. arch. reg. lombardia, comunicazione personale. 17 l. passi pitcher, comunicazione personale. vedi nota 19. 18 l. passi pitcher, comunicazione personale. 19 si tratta di un impianto battesimale ottagonale, probabilmente in fase con l’edificio mosaicato rinvenuto nel cortiletto del torrazzo (quello stesso che dovrebbe identificarsi con l’aula principale della cattedrale, i.e., santa maria) e databile ad un età non anteriore al iv secolo grazie ad un vaso a listello tardo romano rinvenuto nella preparazione del mosaico; l. passi pitcher, comunicazione personale. 20 un’aula con funzioni sacre, addossata al battistero stesso; l. passi pitcher, comunicazione personale. 21 secondo cavitelli (1588), la prima pietra fu posta il 25 agosto 1107 dal vescovo gualtiero. p. galli 91 essere murata in facciata o, secondo altri, nell’altare (puerari, 1971) o costituire il dossale della cattedra episcopale (gandolfo, 2001); invece essa è murata, anzi accantonata nella sagrestia dei canonici, ma non per caso, come vedremo in seguito. di fatto, come precedentemente ricordato, al momento del terremoto il corpo del santo protettore era custodito nella cattedrale in costruzione22, della quale probabilmente erano già in opera e/o pronti per la posa pavimenti a mosaico, portali ed arredi scultorei diversi (vedi oltre). queste evidenze lasciano intendere che la cattedrale fosse ancora assolutamente in fieri piuttosto che, come ipotizzato da quintavalle (1982) in analogia a modena, terminata23. tuttavia, è opinione della critica, da porter (1916) a puerari (1971), che in occasione del terremoto la cattedrale di cremona fosse in avanzata fase di edificazione e che i crolli testimoniati dalle fonti contemporanee abbiano interessato parte dell’edificio (p.e. l’abside) e siano stati proprio causati dalla fragilità dell’edificio in costruzione (enel, 1986). secondo quintavalle (1973) poi, l’edificio attuale è sostanzialmente anteriore al sisma che ne provocò solo il crollo parziale della zona del tiburio. in realtà, le evidenze archeologiche recentemente messe in luce dalla soprintendenza archeologica della lombardia (in passi pitcher, 2003), qui interpretati in chiave archeosismologica, disattendono le opinioni di alcuni degli autori citati, in quanto mostrano come la chiesa attuale non è quella intrapresa nel 1107 e, come dirò, non è quella danneggiata nel 1117. nel corso di scavi eseguiti nella cripta del duomo tra il 1988 ed il 2000, sono fig. 3 ipotesi planimetrica dei diversi complessi episcopali succedutesi prima e dopo il terremoto del 1117. la base in grisé rappresenta l’attuale cattedrale romanica (mod. da puerari, 1971). a tratto pieno, a nord, la basilica paleocristiana di santa maria con lacerti murari e pavimentali (1); a sud la seconda aula paleocristiana di santo stefano, con avanzi dell’abside (2); al centro il battistero. tutto il primo complesso a doppie chiese è databile, su basi archeologiche, al iv-v secolo (vedi testo) e potrebbe essere stato più o meno danneggiato e ristrutturato a seguito dell’assedio di agilulfo nel 603 (vedi interventi databili al vi-viii secolo al battistero). a tratteggio, al centro, la nuova cattedrale di santa maria, cominciata e solo in parte realizzata tra il 1107 e il 1117, posta tra il vecchio edificio che forse le sopravviveva durante la costruzione a nord e la nuova aula dei mosaici del camposanto dei canonici (4) a sud. quest’ultima sostituiva e/o in parte inglobava l’aula paleocristiana precedente di santo stefano. il terremoto del 1117 interrompeva questo nuovo progetto, facendo crollare quantomeno l’edificio all’interno del quale era conservato il corpo di sant’imerio (presumibilmente una delle due aule della basilica paleocristiana). solo dopo una decina d’anni, con un nuovo progetto che prevede la rasatura di tutti gli edifici preesistenti nell’area, si dà inizio all’attuale cattedrale romanica, consacrata nel 1196. hypothetical sketch of the different episcopal complex of cremona during middle age. in gray, the present, romanesque cathedral (after puerari, 1971). in bold the paleochristian complex: north side, the cathedral of saint mary (1, wall and mosaic remains); south, the minor church of saint steven, with apse remains (2); center, the octagonal baptistery, recently excavated in the crypt. the whole complex dates back to the 5th-6th cent. on the basis of archaeological data. dashed line indicates the complex presumably designed in the early 12th cent., as testified by the memorial stone (i.e., 1107 ad; see fig. 4); the saint mary church was placed between the old cathedral and saint steven, in the area of the paleochristian baptistery (3, mosaic remains) and (south) the new minor church of saint steven (? or saint himerius; 4, mosaics). this project was abruptly interrupted by the 1117 earthquakes, which caused, at least, the collapse of the church containing the body of saint himerius (presumably one of the two paleochristian churches), which was extracted from the ruins only 12 years later. the present romanesque cathedral (started few years later and consecrated in 1196) erased all the previous buildings. attestata da una monumentale lapide coeva (fig. 4) ispirata, nell’iconografia wiligelmica, a quella del 1099 nel duomo di modena. essa recita, in maniera apparentemente enigmatica, che nel 1107, fu intrapresa la costruzione di “hec maior aeccl[esi]a cremonenesis q[uae] media videt[ur]”. come a modena, anche qui, originariamente, la lapide avrebbe dovuto 22 imerio, santo calabrese, vescovo di amelia, fu traslato a cremona dal vescovo liutprando nel 971 (sicardus cremonensis, xii-xiii sec.) non si può escludere che esso, al momento del terremoto, fosse ancora nell’attigua vecchia cattedrale di santa maria che sopravviveva, almeno in parte, durante la costruzione della nuova. le macerie che ne occultarono le spoglie per lungo tempo poterono dunque essere anche quelle della vecchia chiesa; ma questo non cambia la valutazione sugli effetti e sulle conseguenze del terremoto a cremona. 23 la critica dell’arte più recente dilata di parecchio i tempi di costruzione delle cattedrali padane. tra anno di fondazione e consacrazione, non dell’altare del santo protettore – che poteva richiedere, tuttalpiù, la presenza della sola cripta – ma dell’edificio terminato si credono necessarie svariate decine di anni (paolo piva, univ. di milano, com. pers.). i terremoti del gennaio 1117 ... 92 stati rinvenuti materiali e mosaici pavimentali “in fase” con quelli noti dell’aula dell’attiguo camposanto dei canonici. entrambi i pavimenti appartengono a due fig. 4 lapide attestante la fondazione della cattedrale di cremona nel 1107, attualmente murata nella sacrestia vecchia. il q[uae] media videt[ur], riferito alla maior eccl[esi]a cremonensis, si riferisce all’originario progetto a più edifici, abbandonato in seguito al crollo del 1117. memorial stone of the foundation of the cremona cathedral in 1107, presently in the old sacristy. the sentence q[uae] media videt[ur] (“that you can see in the middle”), related to the maior eccl[esi]a cremonensis (“main church of cremona”, i.e., santa maria), can be understood if thinking to the original project with three buildings, abandoned after the collapse due to the 1117 earthquake (see fig. 3). fig. 5 lacerti di pavimentazione a mosaico dell’edificio posto ad oriente della chiesa principale (camposanto dei canonici, circa 3 m al di sotto dell’attuale pavimentazione del duomo), contemporanei a quelli rinvenuti ad analoga quota al di sotto della cripta attuale, ed attestanti con essi il progetto edilizio a doppia chiesa del 1107, abbandonato dopo il crollo nel 1117. remains of the mosaic floor found south to the present church (3 m below the present floor of the cathedral), contemporaneous to those excavated at the same elevation in the crypt of the cathedral. these mosaics, dated before 1117, belong to one of the churches of the original 1107 project, collapsed during the 1117 event. 24 l. passi pitcher, comunicazione personale. ma secondo p. piva, su base meramente stilistica, essi sarebbero della terza decade del secolo; comunicazione personale. 25 l’esistenza di due chiese e di un altro edificio nell’area del torrazzo scioglierebbe l’enigma dell’altrimenti inspiegabile media videtur della lapide di fondazione. a livello di ipotesi (vedi fig. 3), l’edificio nell’area del torrazzo potrebbe essere l’aula paleocristiana maggiore di santa maria, più o meno restaurata dopo il sacco di agilulfo; i mosaici della cripta potrebbero appartenere al progetto della nuova cattedrale “quae media videtur” (ante 1117), che inglobava il battistero paleocristiano, e quelli del camposanto dei canonici ad una nuova aula in sostituzione dell’aula minore paleocristiana intitolata a santo stefano (e/o a sant’imerio; quella in precedenza menzionata nel locale caldaie del duomo). col nuovo progetto della cattedrale romanica, non aveva neanche più senso apporre la grande lapide di fondazione in facciata, dal momento che essa descriveva una situazione a più edifici, non più attuale. distinti edifici a cui si è sovrapposta l’attuale cattedrale romanica e la loro quota è circa 3 metri sotto quella dell’attuale pavimentazione (3 e 4 in fig. 3). le stratigrafie archeologiche ed i connotati stilistici li collocano ad una data prossima, ma anteriore al 111724, testimoniando il perdurare dell’organizzazione architettonica del complesso cominciato nel 1107 a chiese doppie, tipica del periodo medievale presso i nuclei episcopali. non è ragionevole pensare che l’aula del prezioso ciclo a mosaici del camposanto (fig. 5) sia stata progettata o, men che mai, eseguita contemporaneamente alla cattedrale romanica, dal momento che quest’ultima si sovrappone p.p. alla prima. e’ cioè molto più verosimile credere che essa fu edificata (in toto o in parte) seguendo una prima fase progettuale (iniziata nel 1107) e subito abbandonata per un motivo di forza maggiore (i.e., il terremoto). dunque, queste chiese, tra cui la principale “quae media videtur” della lapide di fondazione25, sarebbero crollate con il terremoto del 1117, ed i loro ruderi dovettero caratterizp. galli zare a lungo il panorama locale se, come visto, il corpo di sant’imerio potè essere rinvenuto solamente nel 1129. purtroppo, le volte della cripta attuale cedettero, per motivi statici, nel xvii secolo ed i lavori che seguirono sconvolsero gran parte delle stratigrafie medievali, cancellando le tracce di eventuali livelli di crollo antichi e quant’altro26. come poc’anzi anticipato, bisogna aggiungere che diversi autori, ma per ultimo gandolfo (2001), sulla base di evidenze stilistiche ed architettoniche, hanno ipotizzato che una serie di frammenti marmorei decorati e di sculture, attualmente murati in facciata, nel cortiletto del torrazzo, nel cortile del castello sforzesco a milano o, infine, riutilizzati nel portale del transetto settentrionale, appartengano, tra l’altro, a due o più portali della cattedrale iniziata prima del terremoto, salvati in parte dal crollo, smontati, modificati, riscolpiti e rimessi in opera27 (fig. 6). un possibile indizio della riapertura del cantiere dopo il terremoto, ma con un nuovo e più ampio progetto, è la notizia secondo la quale papa callisto ii compone una lite tra il vescovo ed canonici della cattedrale che hanno ceduto la loro abitazione per un nobile fine, invero “ad ampliendam ecclesiam”28. questo documento è del 1124 e circostanzia ulteriormente il fatto che il corpo di sant’imerio fu rinvenuto solo dodici anni dopo il terremoto. con il nuovo cantiere, sotto la spinta di oberto da bovara (vescovo dal 1117 al 1162), si abbandona dunque il progetto dell’impianto a due aule e si procede alla costruzione di un'unica e monumentale cattedrale romanica, a tre navate con ampi transetti, la cui estensione ricopre, di fatto, l’area di tutte le precedenti costruzioni, compresa la nuovissima aula con i mosaici del camposanto dei canonici e la loro stessa residenza. il lungo lasso di tempo intercorso tra il crollo e la rimozione delle rovine potrebbe essere proprio giustificato, oltre che al fisiologico rallentamento di tutte le attività cittadine in seguito al terremoto, anche con il ripensamento progettuale di tutto il complesso episcopale. in ogni modo, nel 1138 la cattedrale è di nuovo a buon punto, come sembra potersi evincere da due documenti che dicono “…in platea quae est ante ecclesiam maiorem…” e “…juxta ecclesiam maiorem…” (codice diplomatico cremonese, viii-xiv sec.). di fatto, il 93 28 luglio del 1141, come recitava una lapide ora perduta (n. xli, in vairani, 188029), il vescovo oberto consacrò l’altare nella cappella di san giovanni, ed altri ne consacrò negli anni successivi (si veda in porter, 1916). finalmente, nel 1196, il corpo di sant’archelao, ma soprattutto quello del santo protettore imerio furono nuovamente traslati nella cattedrale, come ricorda una lapide tuttora visibile30 e come riportato nel chronicon cremonense e nei cronica di sicardus cremonensis (xii-xiii sec)31. nel complesso quindi, da quanto ci dicono le fonti e le evidenze di scavo, la struttura dell’attuale cattedrale romanica nulla avrebbe a che fare con quella intrapresa dieci anni prima del terremoto dal vescovo gualtiero32, a parte frammenti architettonici e scultorei reimpiegati nella ricostruzione e nelle aggiunte successive. 2.3 il terremoto in area emiliana il terremoto, come testimoniato dalla già accennata lapide, potrebbe essere la causa del crollo parziale (le coperture?) dell’abbazia di nonantola. se così fosse, quantomeno tra cremona e nonantola, gli effetti dello scuotimento sismico avrebbero dovuto interessare anche le città intermedie (fig. 1a). le fonti, in realtà, non dicono molto. parma è citata da cronache coeve di area europea come una delle città danneggiate (insieme a verona e venezia). questa circostanza è ripresa da cronache locali trecentesche, che aggiungono che “maxima pars ecclesia sancta maria dirupta fuit“ (chronicon parmense, xi-xiv sec.). secondo quintavalle (1974), tuttavia, la cattedrale di parma, cominciata verso l’anno 1090 e consacrata nel 1106, non mostrerebbe risarciture o ripensamenti dovuti al terremoto e sarebbe tutta pre-1117. dobbiamo quindi restare nel dubbio tra quanto asserito dalla fonte trecentesca e quanto ipotizzato dalla critica archeologica33. 26 a parte una lesione nelle murature del battistero paleocristiano mostratamai dalla d.ssa passi pitcher, ma poco significativa in termini archeosismologici. 27 anche i quattro bellissimi profeti (opera antecedente al terremoto, secondo cochetti pratesi, 1976. fig. 6b), che ancor oggi stanno in precaria e celata attesa, adattati come sono “di taglio” nella strombatura del portale duecentesco di facciata, secondo lo stesso gandolfo (2001) dovevano appartenere ad una primitiva decorazione ad ante del portale della chiesa del 1107 (come quella messa in opera vent’anni dopo a san zeno di verona; valenzano, 1993), dispiegando allora, “di fronte”, tutta la loro originaria espressività. a fianco, sulla sinistra, murati anch’essi in posizione invertita ed in successione verticale anziché orizzontale, vi sono altri coevi lacerti di un ciclo di storie della creazione, testimoniati da due bassorilievi rappresentanti la cacciata di adamo ed eva ed il peccato originale (fig. 6c). 28 l’edificio dovette essere, cioè, abbattuto per fare spazio alla nuova, maestosa cattedrale romanica. 29 ma sembrerebbe essere quella commemorativa di una cappella di santo stefano, ora murata presso l’archivio diocesano, sempre del 1141, quinto kalendas augusti, cioè 28 luglio. 30 l’ho rinvenuta nella cripta, nonostante porter (1916) e tutti a seguire la diano per persa. 31 secondo una lapide dispersa tramandata da bresciani (xvii sec.) la cattedrale fu consacrata dal vescovo sicardo nel 1190, alla presenza di re, vescovi e regine. questa notizia, considerata vera da tutti gli storici successivi, finanche da porter (1916), è assolutamente falsa e piena di errori grossolani (si veda in gallina, 1986). basti pensare che sicardo, nei suoi cronica, non menziona minimamente questo avvenimento di straordinaria importanza. 32 la cui morte, avvenuta nei primi giorni del 1117 (grandi, 1856), si potrebbe suggestivamente ascrivere, in modo diretto o meno, al crollo della cattedrale da lui voluta. in realtà non esistono fonti primarie a questo proposito e la sede vescovile potrebbe essere stata allora addirittura vacante. 33 abbiamo detto come altri reputino questo lasso di tempo insufficiente alla costruzione di edifici così imponenti, dove la data di consacrazione potrebbe riferirsi al solo sacello del protettore. in questo caso, come a cremona, la chiesa potrebbe essere tutta post-terremoto e la mancanza di cesure nelle cortine murarie non testimonierebbe la mancanza di effetti rilevanti a parma. i terremoti del gennaio 1117 ... per piacenza non esistono fonti contemporanee. l’unico indizio è la data di ricostruzione della cattedrale romanica, contenuta in una lapide in facciata: 1122, cinque soli anni, cioè, dal terremoto34. la primitiva basilica, fondata nel 887 (vedi in stocchi, 1984), potrebbe essere stata danneggiata e quindi abbattuta per far posto alla nuova. ma anche in questo caso, seppur non trascurando la coincidenza delle date, si resta nel campo delle ipotesi. analogamente a quanto asserito per piacenza, per castell’arquato (pc) una fonte tarda (campi, 1651), ma generalmente attendibile, dà la riconsacrazione 94 fig. 6 parte degli arredi scultorei e degli elementi architettonici messi in opera o preparati durante il primo cantiere della cattedrale (1107-1117), recuperati, ma non riutilizzati o destinati ad una funzione/collocazione diversa dall’originaria, successivamente al crollo causato dal terremoto del 1117: a, fregio fogliato nell’intradosso dell’architrave del portale del transetto nord (originariamente facciavista dell’architrave di un portale in facciata); b, i quattro profeti (geremia, isaia, daniele, ezechiele) riattati di taglio nella strombatura del portale duecentesco, ma opera di un maestro attivo prima del 1117 (cochetti pratesi, 1976); c, storie della creazione e frammento di stipite di portale nel sottoportico alla sinistra del portale centrale; d, frammenti di stipiti di portali, attualmente conservati al museo del castello sforzesco a milano; tutti questi frammenti, scolpiti prima del 1117, appartenevano ai tre portali in facciata della cattedrale prima del crollo (gandolfo, 2001). i due pannelli superstiti delle storie della creazione, originariamente montati in successione verticale a lato del portale centrale, furono riattati in posizione invertita ed in orizzontale. i profeti erano stati concepiti, così come i pannelli della creazione, per essere posti di faccia ai lati del portale della cattedrale interrotta nel 1117(gandolfo, 2001). remains of some sculptures and architectonic elements belonging to the church started in 1107, which have been recovered and reutilized after the 1117 collapse (see gandolfo, 2001, for details). 34 “centum viceni duo christi mille fuere anni cum ceptum fuit hoc laudabile tempium” p. galli della chiesa carolingia dell’assunta al 1122. a fidenza35 (pc), la cattedrale ricostruita sulle spoglie di quella cadente del ix-x secolo (tassi, 1990), e probabilmente consacrata nel 1106, fu ristrutturata ampiamente da benedetto antelami alle soglie del xiii secolo, venendo riconsacrata nel 120736. anche in questo caso, in assenza totale di fonti, resta il dubbio di una chiesa consacrata nel 1106 e poi ripensata completamente pochi decenni dopo. a modena non abbiamo fonti che attestino danni alla città od alla nuovissima (od in fieri?) cattedrale. la cronologia del massimo tempio mutinense è scandita inequivocabilmente da documenti coevi (relatio traslationis; vedi in stocchi,1984) e da tre lapidi ancora presenti nelle mura. essa fu fondata nel 1099 (su una precedente basilica già in rovina), nel 1106 ne fu consacrato l’altare e solamente nel 1184 la cattedrale fu finalmente consacrata. le opinioni degli storici dell’arte sono però divergenti sulle fasi costruttive. secondo alcuni nel 1106 il progetto dell’architetto lanfranco era ultimato (quintavalle, 1982), secondo altri (in stocchi, 1984) la costruzione della chiesa procedette per decenni, inglobando progressivamente la presisitente, ed il 1106 segna solo la consacrazione di un altare posto in cripta. resta il fatto che gli 85 anni per costruire un edificio molto più piccolo di quello di cremona paiono veramente molti senza pensare ad un qualcosa che ne interruppe, ad un certo punto, i lavori, come ipotizzato da montorsi (1984). bologna, infine, molto distante dalle località danneggiate, non ha fonti contemporanee che ne descrivano gli effetti, sebbene il terremoto sia citato, con danni, dalle cronache del xv-xvii secolo37. nel complesso nulla di certo emerge dall’insieme delle poche, generalmente non coeve e/o locali fonti; né ipotesi tra loro concordanti e/o definitive possono essere tratte dall’analisi architettonica degli edifici attuali. seppur un forte risentimento sia innegabile, in mancanza di dati desumibili da moderni scavi archeologici, gli effetti reali del 1117 in area emiliana restano di incerta entità ed estensione. 3. quadro sismotettonico del cremonese diversamente dai settori di catena appenninica, ove i ratei di deformazione e la competenza delle formazioni affioranti sono sufficientemente elevati da permettere spesso l’affioramento e la conservazione dell’espressione superficiale delle strutture sismogenetiche profonde (p.e., “nastri” e scarpate connessi a faglie prevalentemente dirette), nella pianura padana i possibili indizi di tettonica attiva sono labili e generalmente relativi a blande deformazioni continue, espressione indiretta di movimenti profondi su faglie a cinematica generalmente inversa ed a basso angolo. tali faglie sono relative al complesso sistema frontale di accavallamento degli edifici appenninico ed alpino, di età principalmente messiniana e pliocenica, le cui principali fasi traslative sono scandite, sino al pliocene medio-superiore, dalla presenza di grandi cunei sedimentari a geometria sintettonica (vai et al., 1989). anche i livelli di sismicità dei due dominii, appennico e padano, non sono paragonabili, essendo caratterizzato il primo da eventi di magnitudo elevata (m≥6.5 in appennino centrale e m≥7.0 in quello meridionale), il secondo da eventi generalmente con m≤5.5. solo negli ultimi anni, grazie a dati strumentali relativi alla profondità e al meccanismo focale degli eventi registrati dalla rete sismica nazionale (ingv) e da quelle locali, nonchè a considerazioni di carattere morfotettonico, è stato possibile formulare delle ipotesi sulle caratteristiche sismogenetiche di alcuni tratti dell’area della bassa padana (p.e., terremoto di correggio del 1996, mw=5.4: galli, 1996; terremoto della valle dell’oglio del 1802, ma=5.5: burrato et al., 2003). 3.1 indizi geologici di attività tettonica recente. come detto, nella pianura padana, celati dalle coltri dei depositi plio-pleistocenici, si fronteggiano, con vergenza rispettivamente settentrionale e meridionale, i sistemi di thrust appenninici ed alpini (fig. 1b). al di sotto di questi sistemi, a circa 10 km di profondità, è presente un basamento magnetico anch’esso coinvolto p.p. in sovrascorrimenti non necessariamente in relazione geometrica con quelli del multilayer sedimentario mezo-cenozoico (cassano et al., 1986), ed immergente al di sotto del fronte pedeappenninco, ove raggiunge i 14-15 km. tale basamento presenta delle importanti zone di svincolo trasversale, orientate circa ns e nnessw, che dalla zona dei fronti si estendono per decine di chilometri nell’avampaese (vai, 1989; cnr, 1991; agip, 1996). la distanza dei fronti più esterni appennico ed alpino raggiunge proprio a nordovest di cremona un valore minimo, fino all’accavallamento dei primi sui secondi (area di soresina; figg. 7-8; fantoni et al., 2004). nello specifico, l’area della bassa padana occidentale è caratterizzata in profondità dalla presenza dell’arco di pavia ad ovest e delle pieghe ferraresi ad est. il primo, da voghera, con ampio raggio si protende verso nord, attraversando il po, per poi inflettersi verso sudest, passando sotto cremona, parma e reggio emilia, oltre la quale incontra la terminazione occidentale delle pieghe dell’arco ferrarese (fig. 1b) e dove massimo risulta anche lo spessore dei depositi plioquaternari all’esterno del suo fronte (oltre 7000 metri; p.e., cnr-pfg, 1983). la recente mobilità dell’arco di pavia si palesa direttamente in superficie in diversi punti della piana. il sollevamento di tutta l’area di stradella (a se di pavia), anche a nord del po, ha comportato infatti l’affioramento delle calcareniti messiniane nell’alveo del po stesso. 95 35 all’epoca borgo san donnino. 36 sia all’interno che all’esterno si riconoscono materiali di reimpiego della fase di xi-xii secolo, talvolta così preponderanti “da sembrare quasi restauri di vecchie strutture” (tassi, 1990; p. 123). 37 così, nella cronaca quattrocentesca di francesco pizolpassi, nell’anno 1147 è ricordato un terremoto per il quale caddero edifici in città. questo evento, sconosciuto a tutte le altre fonti note potrebbe essere un errore dell’autore, testimoniando invece gli effetti a bologna del terremoto del 1117: “… el teremote per el qual ruvinone multi edificii e in fra le altre la tora felicianorum in la via de piaza maiore, la qual, cadendo, guastò [-] le loro case e vene' ad habitare in la vale de l'ausa…". a meno che non si tratti del terremoto del 1174, ricordato nelle histor. miscell. bonomiensis (vedi, muratori, rerum ital. script., xviii, 242.) i terremoti del gennaio 1117 ... tale sollevamento, a giudicare dal possibile basculamento verso est di diverse superfici alluvionali coperte da loess nei dintorni di stradella, potrebbe essere perdurato anche nel corso del pleistocene superiore, così come testimoniato da altri indizi geomorfologici (in tellini e pellegrini, 2001). l’anticlinale di san colombano (tra cremona e pavia. 70-80 m sulla pianura circostante; desio, 1965. fig. 1b, 7) è bordata a sudest da una probabile scarpata di faglia. secondo tellini e pellegrini (2001) alcune evidenze superficiali (come la deviazione del lambro e basculamenti e sollevamenti di superfici di età tardopleistocenica) testimoniano un perdurare dell’attività tettonica anche in tempi recenti della struttura afferente all’alto strutturale. poco più ad est, a sw e nw di casalpusterlengo (fig. 7), desio (1965) ha evidenziato un altro alto sotteso da un’anticlinale wnw-ese fagliata che coinvolge nella deformazione anche la successione quaternaria. più ad est, sul fronte più esterno all’arco di pavia, un fenomeno di antecedenza dell’oglio nei pressi di bordolano (circa 15 km a nord di cremona; marchetti et al., 1980. fig. 7) potrebbe testimoniare la continua crescita dell’omonima anticlinale (pieri e groppi, 1981) in epoca post-glaciale. sempre in ambito cremonese, ma relativamente ai domini alpini sepolti a vergenza appenninica, si segnala il pianalto di romanengo (di età pleistocenica mediosuperiore; desio, 1965; cremaschi, 1987. fig. 1b, 7), sulla cui interpretazione in chiave neotettonica si era già espresso desio (1965). si potrebbe infatti trattare di un alto controllato dalla sottostante anticlinale fagliata e-w (desio, 1965, su dati agip, segnala il coinvolgimento del quaternario sepolto nella deformazione; vedi anche fantoni et al., 2004) e modellato solo marginalmente dai corsi d’acqua nel post glaciale. il ripiano termina a nord e a sud con una graduale immersione verso la pianura. più a sud, oltre soresina, è presente un evidente dosso fluviale messo in relazione con il grande paleoalveo n-s dell’oglio; la rilevanza di detto dosso è stata ipoteticamente collegata (pellegrini, 2003) al sollevamento recente dell’anticlinale e-w di caviaga (pieri e groppi, 1981). ulteriori indizi di tettonica attiva desumibili da possibili variazioni negli andamenti planimetrici dei corsi d’acqua sono segnalati ad est di cremona, in una zona tra il po e l’oglio che tenderebbe a sollevarsi (presumibilmente lungo l’asse wnwese dell’anticlinale fagliata – a ne di piadena; pieri e groppi, 1981), allontanando, di fatto a nord ed a sud il corso degli anzidetti fiumi (pellegrini, 2003). il po, infatti, tra cremona e casalmaggiore, è molto discostato dal livello fondamentale della pianura, ampliando la sua valle attuale da 600 m in prossimità del capoluogo a oltre 10 km a casalmaggiore (fig. 7; gerevini, 1998). l’assenza di tracce di centuriazione romana in questa zona (tuttora fortemente caratterizzanti tutto l’agro cremonese; tozzi, 2003) fornisce, inoltre, un indizio cronologico riguardo la migrazione del po verso sud. sollevamento e migrazione degli alvei (con conseguente cancellazione delle tracce di centuriazione) sarebbero infatti avvenuti in epoca medievale/ moderna. per quanto concerne invece la possibile attività recente delle strutture dell’arco di ferrara, oltre che da dati di borehole breakouts (montone e mariucci, 1999), essa potrebbe essere testimoniata dalla continua depressione della sinclinale posta a tergo dell’anticlinale frontale dell’arco. tale struttura avrebbe condizionato in superficie il drenaggio verso il po del secchia e del panaro in epoca post ultimo massimo glaciale (castaldini et al., 1979). 3.2 sismicità. come accennato, il livello di sismicità della bassa padana occidentale è modesto se comparato ad altre aree della penisola italiana, non superando storicamente magnitudo 5.5 ed un’intensità epicentrale di viii 96 fig. 7 schema delle principali strutture plicative sepolte nell’area nordorientale dell’arco di pavia (da agip, 1959; desio, 1965; pellegrini, 2003; vedi fig. 1° per localizzazione). la campitura con “lack of centuriation” indica l’area della bassa cremonese ove il tracciato delle centuriazioni romane è stato forse cancellato dalla deriva verso sud del corso del po (pellegrini, 2003). questo fenomeno, accaduto in epoca medievale, potrebbe essere dovuto alla deformazione superficiale (cosismica?) dell’anticlinale di piadena. in questo senso la struttura di piàdena potrebbe essere una delle possibili sorgenti dell’evento basso padano del 1117. sketch of the main folds and faults buried in the northeastern area of the pavia arch (modified from agip, 1959; desio, 1965; pellegrini, 2003; see fig. 1a for location). hatch with “lack of centuriation” indicates the area where the roman centuriation, still visible elsewhere, has been erased by the southern drift of the po river. this phenomenon, occurred during middle age, could be attributed to the coseismic uplift of the piadena anticline. if this were true, the piadena buried thrust could be considered one of the seismogenetic source of the 1117 multiple event. p. galli grado mcs (gruppo di lavoro cpti, 1999). i terremoti, a parte quello di soncino del 1802 (ma=5.5, io=viii mcs), sono generalmente ubicati tra reggio emilia e parma, ed a nw di quest’ultima (fig. 1b). per quanto riguarda cremona, escludendo il terremoto del 1117, gli effetti risentiti dalla città sono sempre stati inferiori al vii grado (raggiunto, forse, in occasione del terremoto bresciano del 1222; boschi et al., 1995), essendo valutabili risentimenti di vi grado in occasione di altri cinque terremoti storici (tre di ambito locale e di m<5; 1276, 1829 e 1951; due risentimenti di eventi distanti; 1832 e 1914). secondo cavitelli (1588; ma non in gruppo di lavoro, 1999) altri eventi furono fortemente risentiti in cremona nel 1280 (posto a bologna in baratta, 1901), nel 1287 (in baratta, 1901) e nel 1397 (posto nel bergamasco in baratta, 1901), in occasione del quale “multa edificia corruerunt”. il quadro indiziario fornito dagli elementi di carattere geomorfologico, strutturale profondo e sismologico, nel complesso, permette di ipotizzare una possibile attività tettonica residua legata al complesso sistema di accavallamento delle unità appenniniche ed alpine sepolte e del sottostante basamento flessurato. per la struttura di romanengo è, ad esempio, evidente la concordanza ed il probabile nesso causale tra la distribuzione del danneggiamento in occasione del terremoto del 1802, così come rivalutata da albini et al. (2002; sorgente circa e-w), e la geometria dell’anticlinale fagliata sottostante (vedi desio, 1965). analogamente, per il terremoto del 1996, sulla base dei dati strumentali e di sismica di esplorazione (agip, 1996, in galli, 1996) sono state avanzate ipotesi concernenti l’attivazione della rampa laterale della struttura sepolta del cavone e/o di una zona di taglio n-s nel sottostante basamento magnetico. quindi, limitatamente all’arco pavese ed al prospiciente arco alpino, mentre è presumibile che singole e limitate strutture sepolte (p.e. thrust od elementi di svincolo trasversale di lunghezza ≤10 km) siano responsabili specificatamente dei terremoti storici di moderata energia (p.e. quelli del 1438, 1802 e 1832) e strumentali (1971 e 1996), non è assolutamente chiaro quale possa essere il potenziale sismogenetico (inteso come massimo terremoto attendibile) di un’eventuale attivazione congiunta di più strutture sepolte (o di una di dimensioni >10 km) o di grandi porzioni degli elementi di svincolo presenti nel sottostante basamento. 4. discussione e conclusioni per tutto quanto accennato riguardo il terremoto del 1117, appare chiaro che l’attuale ubicazione epicentrale dello stesso (presso verona, gruppo di lavoro cpti, 1999) non rispecchia la complessità dell’evento, invero la distribuzione del danneggiamento desumibile dalle fonti coeve. tralasciando gli effetti di area germanica e pisana appare, infatti, molto difficile attribuire i crolli di località distanti oltre 80 km ad una struttura sismogenetica pedealpina, la stessa che certamente fu la causa del danneggiamento nell’area veneto-trentina. tuttavia, proprio a questo riguardo, non si deve ignorare che un forte risentimento verso sud, anche con danni localizzati (p.e., a guastalla, vii mcs: boschi et al., 1995), abbia avuto luogo in occasione del terremoto dell’asolano del 1695 (io=ix-x, ma=6.6. fig. 1b, associato al thrust asolo-cornuda da galadini et al., 2002. risentito, però, come v mcs a cremona) e, più dubitativamente nel 1222 (terremoto del bresciano; io=viii-ix, ma=6.0; con effetti a modena di vii mcs, secondo boschi et al., 1995). analoghi effetti di “ripresa” delle intensità ai margini pedemontani alpino ed appenninico sono stati evidenziati da magri e molin (1986) per terremoti minori del xix e xx secolo. ritornando al 1117, sulla possibilità di un evento multiplo con aree sorgente separate, galadini e galli (2001) hanno ipotizzato l’attivazione penecontempoeanea di un settore del fronte alpino sud-vergente a se dei m.ti lessini e di parte del fascio delle giudicarie (i.e., il thrust di monte baldo). in realtà, analisi paleosismologiche condotte ad hoc su faglie oloceniche nel dominio lessinio e giudicariense dagli stessi autori non hanno supportato questa ipotesi (galadini et al., 2001a). la mancanza di altri indizi di tettonica attiva lungo le strutture pedemenontane prospicienti verona ed il livello di danneggiamento sofferto dalla stessa in occasione di forti terremoti di origine veneto-friulana hanno quindi indotto galadini et al. (2001b) a ipotizzare per il 1117 una sorgente più orientale, presumibilmente identif icabile col thrust thiene97 fig. 8 profilo geologico semplificato lungo una sezione ~nne-ssw nella pianura padana centrale. e’ evidente la deformazione dei depositi quaternari in corrispondenza delle anticlinali di crescita. (da un profilo sismico convertito in profondità in fantoni et al., 2004). depth-converted, ~nne-ssw geological section from a seismic profile in fantoni et al. (2004). the section shows the deformation (warping and faulting ?) of the quaternary sequence in the central po plain. i terremoti del gennaio 1117 ... bassano (fig. 1b. galadini et al., 2002). un epicentro connesso a tale struttura, adiacente quindi a quello del 1695 ed ancora più distante dagli effetti registrati nella bassa padana, evoca, a maggior ragione, l’occorrenza di uno o più eventi separati, seppur avvenuti negli stessi giorni/ore, in prossimità dell’area di danneggiamento lombardo-emiliana. tuttavia, lo stato attuale delle conoscenze, storiche da un lato e geologiche dall’altro, non permette di definire quali o quante strutture sepolte, tra quelle potenzialmente suscettibili di generare terremoti, possano essersi attivate. da un lato, dando credito alla lettura in chiave cosismica degli effetti descritt i dalla lapide di nonantola, agli indizi di danno in area emiliana, alle notizie sincrone non locali (o locali, ma tarde) di crolli a parma, sino a cremona, saremmo di fronte ad un’area di danneggiamento estesa lungo 100 km di fronte appenninico sepolto (tralasciando le notizie di ambito non locale e non coeve di milano e bologna). tale area richiederebbe l’attivazione penecontemporanea di diverse strutture sepolte tra l’arco ferrarese e quello pavese. limitandosi invece ai soli dati abbastanza attendibili di cremona (storici ed archeosismologici), unitamente al quadro di risentimento certo delineato dalle fonti coeve (milano) e dagli atti notarili dell’area tra piacenza e brescia, ci si potrebbe prefigurare con un’ipotesi di minima l’attivazione di una struttura sufficientemente grande e vicina a cremona da causare il crollo del complesso episcopale e, eventualmente, da provocare danni nelle città limitrofe (p.e., parma), possibilmente cumulando gli effetti con il forte risentimento dovuto al mainshock di pertinenza pedealpina, così come nel caso esemplificato dal citato terremoto asolano del 1695. tale struttura andrebbe ricercata tra quelle per le quali la letteratura ha indicato indizi di attività tardo pleistocenica (p.e., colombano, casalpusterlengo, bordolano, piàdena), tutte all’incirca di dimensioni di 10-20 km e potenzialmente capaci, perciò, di generare eventi di m≅ 6.2-6.5, invero caratterizzati da capacità distruttiva locale (p.e., ix mcs) e di un forte risentimento areale, non scevro da danni isolati (vii mcs). tra queste, quella di piàdena, come detto, sembrerebbe essere stata attiva in tempi storici, ed eventualmente post-romani, con una deformazione areale in superficie sufficiente a spingere il corso del po a sud e dell’oglio a nord. tale fenomeno, se non imputabile ad un sollevamento temporalmente continuo negli ultimi 2000 anni (ma quindi asismico), ma bensì discreto (e quindi cosismico), potrebbe essere ipoteticamente connesso all’occorrenza di un epicentro locale della sequenza del 1117. ringraziamenti la d.ssa l. passi pitcher (soprintendeza archeologica della lombardia), nel dicembre 2003, mi ha pazientemente illustrato tutte le evidenze di scavo relative alla cattedrale di cremona. gran parte delle ipotesi relative al crollo ed alla ricostruzione del duomo di cremona sono state formulate insieme e grazie a lei. ringrazio il prof. p. piva (università di milano, dipartimento di storia delle arti, della musica e dello spettacolo) per le proficue discussioni sulle vicissitudini edilizie delle cattedrali padane nel medioevo. ringrazio la d.ssa m. volontè (museo civico di cremona), la d.ssa v. leoni (università di pavia) e il dr. r.camassi (ingv) per l’aiuto fornito. andrea tertulliani e diego molin hanno rivisto e corretto il manoscritto, fornendo utili e sostanziali suggerimenti. bibliografia citata agip (1959) relazione geologica e mineraria sulla pianura padana, in: i giacimenti gassiferi dell’europa occidentale, accademia nazionale dei lincei, ii, roma. agip (1996) attività sismica registrata dalla rete agip nell’area di correggio, 1993-1996. rapporto interno. alberto di bezano (xiv sec.) alberti de bezanis abbatis s. laurentii cremonensis cronica pontificum et imperatorum, mgh, scriptores rerum germanicarum in usum scholarum separatim editi, iii, ed. holder-hegger, 1908. albini p., burrato p., valensise g. (2002) il terremoto del 12 maggio 1802 della valle dell’oglio (italia settentrionale): nuove inferenze sulla sorgente sismogenetica da dati macrosismici e geologici, gngts, atti del 21° convegno nazionale/01.15. annales veronenses (xiii sec.) annales veronenses antiqui pubblicati da un manoscritto sarzanese del secolo xiii, in c. cipolla, bullettino dell'istituto storico italiano, 29, verona, 1908, 7-81. beroldus (xii sec.) sive ecclesiœ ambrosianœ kalendarium et ordines, a c. di m. magistretti, milano, 1894. boschi e., ferrari g., gasperini p., guidoboni e., smriglio g., valensise g. (eds.) (1995) catalogo dei forti terremoti in italia dal 461 a.c. al 1980, ingsga, bologna, 973 pp. bresciani g. (xvii sec.) historia ecclesiastica di cremona qual contiene le vite de' vescovi d'essa città dal anno 53 di nostra salute per tutto l'anno 1642, , bscr, lc, mss. bresciani, 9. burrato p., cucci f., valensise g. (2003) an inventary of river anomalies in the po plain, northern italy: evidence for active blind thrust faulting, annals of geophysics, 46, 865-882. campi, p. m., 1651. dell’istoria ecclesiastica di piacenza (dalle origini al 1435), piacenza. cassano e., anelli l., fichera & cappelli v. (1986) pianura padana interpretazione integrata di dati geofisici e geologici. agip, 73° congresso s.g.i. castaldini d., gasperi g., panizza m., pellegrini m. (1979) – neotettonica dei fogli 74 (reggio emilia) e 75 (mirandola) nell’intervallo da 18000 b.p. all’attuale, cnr-pfg, nuovi contributi alla realizzazione della carta neotettonica d’italia, 251, 317-332. cavitelli l. (1588) – lodovici cavitellii patritii cremonen. annales. quibus res ubique gestas memorabiles a patriae suae origine usque ad annum salutis 1583, cremona. chronicon cremonense (xi-xiii sec.) ab anno 1096 usque ad anno 1232, a c. di. l. a. muratori, rerum italicarum scriptores, vii, 631-642, milano, 98 p. galli 1725. chronicon parmense (xi-xiv sec.) ab anno 1038 usque ad annum 1338, a c. di g. bonazzi, rerum italicarum scriptores, ix, 9, città di castello, 1902. c.n.r.-pfg (1983) – neotectonic map of italy, progetto finalizzato geodinamica, 114. quaderni della ric. scient., 4, firenze. c.n.r. (1991) structural model of italy. scale 1:500.000, sheet 1, prog. final. geodinamica. cochetti pratesi l. (1976) i profeti di cremona. problemi dell’occidente romanico, biblioteca di cultura, 90, bulzoni. codice diplomatico cremonese (viii-xiv sec.) 7151334, a c. di l. astegiano, i, historiae patriae monumenta, ii, xxi, 112, torino 1895. codice diplomatico della lombardia medievale (viii-xii sec.), a c. di m. ansani, università degli studi di pavia, 2000-2005 (url:http://cdlm.unipv.it) codice diplomatico longobardo (viii sec.) a c. di l. schiaparelli, fonti per la storia d’italia, 64/1, roma, 1929. cremaschi, m. (1987) palesols and vetusols in the central po plain (northern italy), unicopli, studi e ricerche sul territorio, milano. cronichella cremonese (xi-xiii sec.) in a. dragoni, 1818 in eunte, miscellanee cremonesi, biblioteca statale di cremona, dep. lib. civica, ms aa6.1, p.182. desio, a., 1965. i rilievi isolati della pianura lombarda ed i movimenti tettonici del quaternario. ist. lombardo accademia di scienze e lettere, rendiconti, classe di scienze (a), 99, 881-894. donazione di decima (xii sec.) archivio di stato di verona, fondo clero intrinseco, b. 13, cart. n. 7, copia del 1327. enel (1986) il terremoto del 3 gennaio 1117, studi ed indagini per l’accertamento della idoneità tecnica delle aree suscettibili di insediamento di impianti nucleari, regione lombardia, area viadana, indagini di sismicità storica, rapp. finale, ismes-ratdgf-0012, 907 pp. fantoni r., bersezio r., forcella f. (2004) – alpine structure and deformation chronology at the southern alps-po plain border in lombardy, boll. soc. geol. it., 123, 463-476. galadini f., galli p. (1999) paleoseismology related to the displaced roman archaeological remains at egna (adige valley, northern italy), tectonophysics, 308, 171-191. galadini f., galli p. (2001) archaeoseismology in italy: case studies and implications on long-term seismicity, j. of earthquake engineering, 5, 35-68. galadini f., galli p., cittadini a., giaccio b. (2001a) late quaternary fault movement in the mt. baldolessini mts. sector of the southalpine area (northern italy), geologie en mijnbouw, 80, 187208. galadini f., galli p., molin d., ciurletti g., (2001b) searching for the source of the 1117 earthquake in northern italy: a multidisciplinary approach, t. glade et al. (eds.), the use of historical data in natural hazard assessments, kluwer academic publisher, 3-27. galadini f., poli m. e., zanferrari a. (2002) sorgenti sismogenetiche responsabili di terremoti distruttivi nell’italia nord-orientale, gngts, riassunti estesi del 21° convegno nazionale, 27-30. galli, p. (1996) inquadramento sismotettonico dell’area del terremoto del 1996, in: decanini l., di pasquale g., orsini g. (a c. di), ricognizione degli effetti del sisma del 15 ottobre 1996 in provincia di reggio emilia, rapp. tecnico del servizio sismico nazionale, ssn/rt/97/4, 13-26. gallina g. (1986) anno 1190: il vescovo di cremona sicardo consacra la nuova cattedrale. storia o leggenda?, la vita cattolica, 45, 8. gandolfo f. (2001) la cattedrale nel medioevo: i cicli scultorei, in: a. tomei (a cura di), la cattedrale di cremona, affreschi e sculture, banca di credito cooperativo del cremonese, casalmorano, 1766. gerevini c. (1998) analisi geologico-geomorfologica del territorio cremonese compreso tra oglio e po e sua evoluzione neotettonica. tesi di laurea inedita, università di pavia. grandi a. (1856) descrizione della provincia e diocesi cremonese, cremona-codogno. gruppo di lavoro cpti (1999) catalogo parametrico dei terremoti italiani. ing, gndt, sga, ssn, bologna 1999, 92 pp. kehr p. f. (1961) italia pontificia, vii, i, venezia e istria, berlino. magri g., molin d. (1986) i terremoti del 3 gennaio 1117 e del 25 dicembre 1222, rapporto enea, rti-pas-isp-geol lo (86)2, 9 pp. marchetti g., perotti c., vercesi p. baroni c. (1980) – note illustrative degli elaborati cartografici… (f. 60-piacenza e 61cremonae degli elaborati cartografici...) e … (f.71-voghera, f.72-fiorenzuola d’arda, f.83-rapallo e f.84-pontremoli) in contributi al la realizzazione della carta neotettonica d’italia, cnr-pfg, 356, roma. mirabella roberti m. (1979) – un mosaico paleocristiano a cremona, numismatica ed antichità classiche, 8, 279-285. montorsi w. (1984) riedificazione del duomo di modena e traslazione dell'arca di san geminiano. cronaca e miniature della prima eta' romanica, modena. montone p., mariucci m.t. (1999) active stress along the ne external margin of the apennines: the ferrara arc, northern italy, j. of geodynamics, 28, 251-265. passi pitcher l. (2003) archeologia della colonia di cremona: la città e il territorio, in: p. tozzi (a cura di), storia di cremona. l’età antica, banca cremonese credito cooperativo, 130-229. paulus diaconus (viii sec.) historia langobardorum, ed. georg waitz, monumenta germanica historiae, scriptores, rerum langobardicarum, hannover, 12-187, 1878. pellegrini l. (2003) aspetti geomorfologici, in : p. tozzi (a cura di), storia di cremona. l’età antica, banca cremonese credito cooperativo, 17-37. pieri m., groppi g. (1981) subsurface geological structure of the po plain (italy), consiglio nazionale delle ricerche, progetto finalizzato geodinamica, sottoprogetto “modello strutturale”, pubblicazione 414. pizolpassi f. (xv sec.) summa hover cronica 60099i terremoti del gennaio 1117 ... 1440, a cura di a. antonelli e r. pedrini, bologna 2001. porter a. k. (1916) lombard architecture, ii, new haven. puerari a. (1971) il duomo di cremona, milano. relatio traslationis (xii sec.) – r. t. corporis sancti geminiani, ms. dell’archivio capitolare di modena. quintavalle a. c. (1973) la cattedrale di cremona, cluny, la scuola di lanfranco e wiligelmo, in "storia dell'arte", 18, 117-172. quintavalle a. c. (1974) la cattedrale di parma e il romanico europeo, parma. quintavalle a. c. (1982) l'immagine e l'eresia, in: “romanico padano, romanico europeo, parma. scalia g. (1963) epigraphica pisana: testi latini sulla spedizione contro le baleari del 1113-1115 e su altre imprese antisaracene, in "miscellanea di studi ispanici," vi. scardeone b. (1560) de antiquitate urbis patavii, basileae. sicardus cremonensis (xii-xiii sec.) cronica, monumenta germanica historica, scriptores, 31, ed. holder-egger, 1903, pp. 22-183. stocchi s. (1984) l’emilia-romagna, in: chierici s. (a cura di), italia romanica, jaka book, milano. tassi r. (1990) il duomo di fidenza, silvana editoriale, cinisello balsamo. tellini c., pellegrini l. (2001) – forme di origine tettonica, note illustrative della carta geomorfologia della pianura padana, suppl. geogr. fis. dinam. quat., iv, 55-199. tozzi p. (2003) gli antichi caratteri topografici di cremona, in: p. tozzi (a cura di), storia di cremona. l’età antica, banca cremonese credito cooperativo, 96-129. vai g.b. (1989) migrazione complessa del sistema fronte deformativo-avanfossa-cercine periferico: il caso dell’appennino settentrionale. mem. soc. geol. it., 38, 95-105. vairani t.a. (1880) inscriptiones cremonenses universae, cremona. valenzano g. (1993) la basilica di san zeno in verona. problemi architettonici, vicenza, 93-102. 100 ms. ricevuto il 18 gennaio 2005 testo definitivo ricevuto il 10 marzo 2005 ms. received: january 18, 2005 final text received: march 10, 2005 p. galli imp.aprile& il ruolo dei depositi piroclastici nell’analisi cronostratigrafica dei terreni quaternari del sottosuolo della piana campana (italia meridionale ) francesco aprile1, alessandro sbrana2 & romeo m. toccaceli2 1dipartimento di scienze della terra. università di napoli “ federico ii “ 2dipartimento di scienze della terra. università di pisa riassunto: aprile f. et al., il ruolo dei depositi piroclastici nell’analisi cronostratigrafica dei terreni quaternari del sottosuolo della piana campana (italia meridionale). (it issn 0394-3356, 2004). attraverso il riesame critico delle sequenze stratigrafiche di sondaggi meccanici significativi, eseguiti nell’ambito della piana campana, correlate con i risultati di recenti studi vulcanologici, viene proposto un nuovo assetto dell’architettura del sottosuolo e ridefinita la posizione cronostratigrafica dei terreni pleistocenici ed olocenici di riempimento del bacino sedimentario e vulcanico campano. le correlazioni cronostratigrafiche tra le unità sedimentarie sono state effettuate assumendo come livelli guida le due unità da flusso piroclastico dell’ignimbrite campana (~39 ka b.p.) e dell’ignimbrite di taurano (~157 ka b.p.) datati radiometricamente, presenti sia in affioramento che nel sottosuolo della piana. ciò ha consentito di riposizionare cronologicamente i depositi marini rinvenuti in foro al disotto dell’ignimbrite di taurano al margine dei rilievi carbonatici dimostrando che la pianura campana è stata interessata da una marcata subsidenza quantomeno a partire dal tardo pleistocene medio. è stata riconosciuta l’analogia dell’assetto strutturale e stratigrafico, nel sottosuolo, tra l’area pedemontana della piana del sarno con i corrispondenti settori di nola, cicciano e cancello disposti secondo una direttrice nw-se lungo la fascia di raccordo tra la zona pianeggiante della piana campana ed i rilievi carbonatici bordieri. l’analisi geometrica della disposizione delle unità individuate nel sottosuolo ha portato al riconoscimento di un complesso piroclastico, nella parte centrale della piana, al momento non ben differenziato, di estensione e potenza significative, posizionato al tetto della ignimbrite di taurano. l’esame dei dati stratigrafici e la ricostruzione dei rapporti geometrici tra le unità, ha permesso l’allestimento di sezioni geologiche tracciate lungo direzioni significative, che forniscono un quadro inedito delle caratteristiche stratigrafiche del sottosuolo della piana campana ed un preliminare contributo alla conoscenza della evoluzione strutturale recente. abstract: aprile f. et al., the role of pyroclastic deposits in the chronostratigraphic analysis of the quaternary terrains in the subsoil of the campanian plain (southern italy). (it issn 0394-3356, 2004). the critical reinterpretation of stratigraphic data of mechanical soudings concerning the subsurface of campanian plain (southern italy) provides a new picture of the geometry and chronostratigraphic position of the quaternary deposits filling the sedimentary basin of this plain. the radiometrically dated ignimbrite deposits, of campanian ignimbrite (~39 ka b.p) and taurano ignimbrite (~157 ka b.p), have been considered as levels guide in carrying out the correlations between the lithological units. this has allowed the singling out of marine sediments, previuously not well considered, underlaying the taurano ignimbrite indicating that the campanian plain underwent subsidence even prior to upper pleistocene. the structural and stratigraphic analogy, in the subsurface, among the sarno’s area with the corresponding sectors of nola, cicciano and cancello located along the carbonatic reliefs, bordering the plain to nw-se direction, has also been recognized. finally a pyroclastic deposit at present not well differentiated, topographically localized in the central area of the plain, to the top of taurano ignimbrite, has been recognized. the re-examination of the stratigraphical sequences, picked in more significant sections, provides a new frame of the subsurface characteristics of the campanian plain and a preliminary contribution for the knowledge of the recent structural evolution. parole chiave: piana campana; tefra; ignimbriti;pleistocene superiore e medio; depositi marini. keywords: campanian plain; tephra; ignimbrites; upper and middle pleistocene; marine deposits, boreholes. il quaternario italian journal of quaternary sciences 17(2/1), 2004, 547-554 la piana campana: assetto schematico geologico-strutturale e vulcanologico l’evoluzione geologico-strutturale della piana campana e le relazioni con il vulcanismo quaternario sono state oggetto di una vasta messe di lavori scientifici (ippolito et al., 1973; aprile & ortolani, 1978; finetti & morelli, 1974; brancaccio et al .,1991; cassano & la torre, 1987; bruno et al.,1998). da questi risulta che la piana si è impostata fisiograficamente in un graben peritirrenico – di età plio-pleistocenica – esteso dal monte massico all’alto strutturale della penisola sorrentina e governato da sistemi di faglie dirette, con notevoli rigetti, sia in direzione appenninica che antiappenninica. al suo interno, favorita anche da fenomeni subsidenti, si è verificata una intensa aggradazione sedimentaria che ne ha determinato il parziale colmamento (fig. 1) anche la stratigrafia del sottosuolo della piana è stata indagata da vari autori (aprile & ortolani,1985; cinque et al., 1991; romano et al., 1994; barra et al., 1996; aprile & toccaceli, 2002) che hanno accertato la presenza di varie unità stratigrafiche, marine, continentali, transizionali e vulcaniche a partire dal pleistocene all’attuale. la mancanza di sedimenti marini pliocenici nelle sequenze stratigrafiche dei pozzi profondi perforati nella piana del volturno (ippolito et al., 1973) e trecase1, al margine sud-orientali del somma-vesuvio, (brocchini et al., 2001), induce inoltre a concludere che la piana sia rimasta in ambiente continentale durante tale epoca (brancaccio et al., 1991; cinque et al., 1993), 548 f. aprile, a. sbrana & r.m. toccaceli conoscendo, in seguito, una marcata subsidenza a partire, quantomeno, dal tardo pleistocene medio (aprile & toccaceli, 2002), se non addirittura dal plio-pleistocene (ietto & sgrosso, 1963), e fasi trasgressive fino all’olocene. brocchini et al., (2001), sulla base di una revisione critica dei dati del pozzo trecase 1, ritengono che l’area vesuviana abbia subito una subsidenza, rispetto al livello di base attuale, di circa 40 metri negli ultimi 37 ka. cinque (1991), per contro, riporta limitatamente alla piana del sarno (costituente, a sud del somma vesuvio, il prolungamento, della piana campana in s.s) un valore di circa 30 metri negli ultimi 130 ka . particolarmente numerosi risultano gli studi sulla storia vulcanica della piana campana; molti di questi sono mirati alla comprensione della genesi della ignimbrite campana (ic), il deposito ignimbritico trachitico che con i suoi 150-300 km3 di volume (rosi & sbrana, 1987; orsi et al., 1999 ; rolandi et al., 2003) costituisce la formazione vulcanica più largamente rapfig. 1 schema geologico della piana campana: 1 sedimenti alluvionali e vulcanoclastici quaternari. 2 complesso vulcanico del somma-vesuvio. 3 complessi vulcanici dei campi flegrei, procida e ischia. 4 complesso vulcanico del roccamonfina. 5 unità terrigene mioceniche e plioceniche. 6 unità carbonatiche mesozoiche. 7 principali elementi tettonici. geological scheme of the campanian plain: 1 alluvial and volcanoclastic quaternary sediments. 2 -somma-vesuvius volcanic complex. 3 phlegrean fields, procida and ischia volcanic complexes. 4 roccamonfina volcanic complex. 5 -miocene and pliocene terrigeneous sedimentary rocks. 6 -principal tectonic elements. presentata nella regione. l'area sorgente della ignimbrite campana viene posizionata da alcuni autori nell’area calderica flegrea (rosi & sbrana,1987; fisher et al., 1993; orsi et al.,1999), o nella cosiddetta “fossa di acerra” a ne di napoli (scandone et al.,1991), altri autori ne ipotizzano l’origine da una o più eruzioni fissurali posizionate lungo preesistenti linee tettoniche con direzione ne-sw, nwse e e-w associate all’evoluzione della catena appenninica (di girolamo,1968; 1970; 1978; di girolamo et al., 1984; barberi et al., 1978; lirer et al., 1987; de vivo et al., 2001; rolandi et al., 2003). de vivo et al., (2001) hanno individuato e datato radiometricamente altri prodotti piroclastici – sia in affioramento che nel sottosuolo della piana campana – di età più antica della ic spostando all’indietro fino ad oltre 300 ka b.p l’inizio dell’attività vulcanica nella piana. brocchini et al., (2001) invece, ritengono che a partire da 400-300 ka b.p e fino alla emissione della ic non esistano evidenze di attività vulcanica nella parte vesuviana della piana. bellucci et al., (2003) segnalano, in corrispondenza del margine orientale dei monti di caserta, al letto della ic, la presenza di depositi da flusso piroclastico prevalentemente pomicei (pumice flow) non l itoidi, da essi correlati al la formazione di durazzano (~116 ka b.p). de vivo et al., (2003) oltre a ritenere che la formazione della ic sia in realtà costituita da due unità sovrapposte corrispondenti a due distinti eventi ignimbritici compresi in uno stretto intervallo temporale, ritengono che la storia vulcanica della piana campana comprenda la deposizione di varie coltri ignimbritiche di cui 3 – ben differenziate litologicamente e rappresentate rispettivamente dall’ignimbrite di seiano (~ 289÷245 ka b. p), dall’ignimbrite di taurano (~ 157 ka b.p) e da quella di durazzano (~116 ka b.p) – sono precedenti alla deposizione della ic. i tefra della piana campana come metodologia per le correlazioni crono stratigrafiche delle unità sedimentarie quaternarie del sottosuolo le ignimbriti trachitiche, datate radiometricamente, presenti nella piana campana sia in affioramento che nel sottosuolo,costituiscono preziosi livelli guida (narcisi, 1994) per la determinazione cronostratigrafica delle altre unità sedimentarie, di varia facies litologica, ad essi intercalati. recenti studi vulcanologici (de vivo et al., 2001) oltre a datare la ic (39.29 ± 0.11 ka b.p.), hanno individuato lungo i rilievi bordieri della piana del sarno un altro deposito da flusso piroclastico, in facies di tufo giallo litoide, sottostante la ic, da essi denominato ignimbrite di taurano (it) datato a 157.4 ± 1.00 ka b.p. tale unità si presenta in affioramento con caratteristiche petrografiche e stratigrafiche tipiche così riassumibili ( de vivo et al., 2003): a) aspetto e consistenza di tufo giallo litoide; b) spessore non inferiore ai 6 metri ; c) stratigraficamente si posiziona su un livello di pomici e ceneri dello spessore di circa 1.5 m e risulta sottoposta ad un paleosuolo di circa 0.7 m a sua volta sottogiacente a circa 1 m delle cosiddette “pomici basali” della ic; il tutto è ricoperto dalla ic in facies di tufo grigio campano. nel sottosuolo, in settori significativi, ai fini della 549il ruolo dei depositi piroclastici ... ricostruzione dell’assetto stratigrafico e strutturale della piana proposto nel presente lavoro, al di sotto della ic, si individua una unità tufacea gialla litoide di spessore variabile, ma sempre superiore ai 6 – 8 metri, correlabile, anche in base ad analogie geometriche e stratigrafiche con gli affioramenti segnalati (de vivo et al., 2003), con la ignimbrite di taurano. tale formazione è stata quindi assunta come marker di riferimento per riposizionare cronostratigraficamente i depositi marini rinvenuti al suo letto; infatti, aprile & toccaceli (2002), sulla scorta di tali dati e di quelli desunti da sondaggi profondi ubicati lungo la fascia pedemontana della piana di sarno al raccordo con i rilievi carbonatici bordieri (nicotera & civita, 1969), hanno individuato nel sottosuolo, al di sotto dell’ignimbrite di taurano, depositi di spiaggia attribuibili quantomeno al tardo pleistocene medio, spostando quindi all’indietro – rispetto al pleistocene superiore, come finora ritenuto – l’attività subsidente del settore di piana campana posto a se del complesso sommavesuvio. discussione dei dati e correlazioni stratigrafiche per lo svolgimento della presente ricerca sono stati reperiti presso enti e società specializzate alcune centinaia di stratigrafie relative a sondaggi meccanici, di profondità significative, realizzati nella piana campana negli ultimi 50 anni ( fig.2) per svariate finalità; su tali dati è stata poi eseguita una rigorosa e minuziosa attività di omogeneizzazione stratigrafica ,di analisi di facies e di ricostruzione dei rapporti geometrici tra le varie unità piroclastiche e sedimentarie riconosciute. particolare attenzione è stata posta nel riconoscimento della it dalle altre due formazioni ignimbritiche pre ic (ignimbriti di durazzano e di seiano) riscontrate nell’area campana (de vivo et al., 2003); del resto, come precedentemente esposto, le caratteristiche litologico-stratigrafiche tipiche della it la rendono individuabile, con relativa facilità, anche nei sondaggi meccanici. la formazione di durazzano, infatti si presenta come un pumice flow mai litoide (bellucci et al., 2003 ; de vivo et al., 2003) di spessore intorno ai due metri mentre quella di seiano, risulta caratterizzata (de vivo et al., 2003) dalla sovrapposizione di 3 distinti depositi di flusso piroclastico di colore rossastro e più o meno alterati. le analisi condotte, alla luce delle nuove conoscenze vulcanologiche, ed il riassetto delle geometrie tra le unità individuate per il sottosuolo campano, hanno consentito l’allestimento di una serie di sezioni geologiche significative (fig. 3) che evidenziano un quadro dell’architettura geologica quaternaria del sottosuolo della piana campana legata all’evoluzione recente. la verifica e comparazione dei dati ottenuti, per l’intero sviluppo della piana campana, ha permesso di individuare tre principali settori (settori a, b, c1, c2) disposti parallelamente alla linea di costa (fig. 4). lungo direttrici longitudinali e trasversali a questi è stato inoltre individuato anche un comportamento differenziato nell’ambito della recente evoluzione tettonica. settore a): nel sottosuolo, lungo la fascia di raccordo con i rilievi carbonatici che bordano in direzione 550 ne la piana campana, da sarno a cancello, risultano presenti condizioni stratigrafiche e strutturali simili. infatti, a parte la presenza del substrato mesozoico carbonatico, il motivo stratigrafico ricorrente è caratterizzato dalla presenza e sovrapposizione stratigrafica lungo tutta la direttrice sarno-cancello di due depositi di flusso piroclastico correlati (de vivo et al., 2001; aprile & toccaceli, 2002), dall’alto verso il basso stratigrafico, con la ic (~39 ka b.p.) nella facies del tufo grigio campano e con l’ignimbrite di taurano (~157 ka b.p.) in facies di tufo giallo litoide. per quanto riguarda la morfologia del tetto della ic se ne riscontra una graduale immersione, procedendo verso il centro della piana, tale andamento non sembra essere dovuto a cause tettoniche, ma alla preesistente morfologia su cui si è adagiata, sebbene a luoghi, in affioramento, si osservano brusche soluzioni di continuità nell’unità ignimbritica che possono indurre a ritenere la presenza di faglie. anche i l tetto dell’ignimbrite di taurano, oltre a tracce di erosione in ambiente continentale, presenta uno sviluppo progressivamente degradante sia verso sw che verso nw, in direzione del volturno, che ne determina lo sprofondamento e la scomparsa nei sondaggi; tale strutturazione risulta presumibilmente causata dalle fasi tettoniche post 157 ka b.p. comune, lungo tutto questo settore, è inoltre il rinvenimento, al di sotto della ignimbrite di taurano, di depositi marini la cui età risulta evidentefig. 2 ubicazione dei sondaggi meccanici. tracce delle sezioni geologiche location of boreholes. cross-sections marks f. aprile, a. sbrana & r.m. toccaceli fig. 3 sezioni geologiche schematiche: 1 depositi di spiaggia ed eolici (attuale – recente); 2 depositi alluvionali e piroclastici subaeree ( in posto e/o rimaneggiate) f legree e vesuviane (attuale – olocene); 3 tufo giallo del gauro (circa 10,5 ka b.p.); 4 tufo giallo napoletano (circa 12 ka b.p.); 5 depositi alluvionali e transizionali (lagunari e palustri ) del “complesso versiliano”; 6 depositi di spiaggia e litorali del “complesso versil iano”; 7 piroclastici e lave dell’edificio vulcanico del sommavesuvio (olocene); 8 depositi alluvionali e piroclastici in posto o rimaneggiate post ic (olocene – tardo pleistocene superiore); 9 lave del monte somma (tardo pleistocene superiore); 10 ignimbrite campana (circa 39 ka b.p.).; 11 depositi marini del tardo pleistocene superiore; 12 depositi alluvionali e di conoide di “scanzano” (pleistocene superiore); 13 depositi marini del pleistocene superiore; 14 depositi alluvionali e di conoide di “gragnano” (pleistocene superiore); 15 complesso piroclastico indifferenziato (tardo pleistocene medio – pleistocene superiore); 16 ignimbrite di taurano (circa 157 ka b.p.); 17 depositi alluvionali, lacustri e piroclastici rimaneggiate (tardo pleistocene medio – pleistocene superiore); 18 depositi marini e di spiaggia del tardo pleistocene medio – pleistocene medio (?); 19 termini calcareo-dolomitici mesozoico-terziari; 20 faglia certa; 21 faglia presunta. schematical geological sections: 1 present beach and eolian recent deposits; 2 alluvial deposits and subaerial pyroclastic products (in situ or reworked) of plhegrean fields and somma-vesuvius volcanic complex (olocene); 3 “gauro” yellow tuff (about 10,5 ky b.p.); 4 neapolitan yellow tuff (about 12 ky b.p.); 5. alluvial, palustrine and lagoonal deposits of the “versilian complex”; 6 beach and shore sediments (with peat levels) of the “versilian complex”; 7 lavas and pyroclastic products of somma-vesuvius complex (olocene); 8 alluvial deposits and subaerial pyroclastic products (in situ or reworked) post-cgt (olocene – late upper pleistocene); 9 monte somma lavas (late upper pleistocene); 10 campanian grey tuff (about 39 ky b.p.); 11 beach and marine deposits (late upper pleistocene); 12 “scanzano” alluvial fan deposits (upper pleistocene); 13 marine deposits (upper pleistocene); 14 “gragnano”alluvial fan deposits and recent alluvial or debris cones deposits (upper pleistocene); 15 indifferenziated volcanoclastic complex (late middle pleistoene – upper plesitocene); 16 taurano yellow tuff (about 157 ky b.p.); 17 alluvial, lacustrine and pyroclastic deposits (late middle pleistoene – upper plesitocene).; 18 beach and marine deposits (late middle pleistocene); 19 dolomites and limestones (cenozoic – mesozoic).; 20 certain fault; 21 presumed fault. 551il ruolo dei depositi piroclastici ... 552 mente più antica di 157 ka b.p. e quanto meno attribuibili ad un tardo pleistocene medio (aprile & toccaceli, 2002); tale attribuzione cronologica risulta essere compatibile con quanto riportato da altri autori (ietto & sgrosso,1963) che segnalano la presenza di depositi marini terrazzati, in corrispondenza del versante meridionale dei rilievi più occidentali della dorsale di avella, di età plio-pleistocenica inferiore, correlandoli con le argille quaternarie poste a varia profondità nel sottosuolo della piana del sarno e nei dintorni di maddaloni. l’assetto cronostratigrafico ricostruito fa assumere a questi sedimenti marini il ruolo di una vera e propria unità guida e di riferimento che consente di ritenere che la subsidenza nella pianura campana sia stata attiva, in questo settore, quanto meno dal tardo pleistocene medio – se non addirittura dal plio-pleistocene – e non solo nel pleistocene superiore come finora ritenuto (brancaccio et al., 1991; cinque,1991; romano et al., 1994). settore b): costantemente presente nel sottosuolo o, talora affiorante, lungo tutto questo settore è la presenza della ic, generalmente nella facies di tufo grigio campano, il cui tetto tende ad approfondirsi procedendo verso la costa; a luoghi risulta mancante ma ciò non ne esclude la presenza a profondità maggiore di quella raggiunta con i sondaggi; del resto cassano & la torre (1987), in base ai risultati geofisici, prolungano la presenza del tufo grigio campano fino alla linea di costa. lungo questa fascia centrale della piana, al letto della ic si rinviene un deposito, costituito da un’alternanza di prodotti piroclastici incoerenti, al momento non meglio classificati nel contesto cronostratigrafico del sottosuolo della piana, sebbene, nel tratto pomigliano d’arco marigliano, le geometrie ricostruite consentono di posizionarlo al tetto della ignimbrite di taurano da cui se ne differenzia anche litologicamente; tale constatazione porta quindi a ritenere che tali prodotti siano comunque compresi nell’intervallo temporale 157-39 ka b.p. questa unità vulcanica, per le caratteristiche cronostratigrafiche e geometriche individuate può, in generale, interfacciarsi con i sedimenti del pleistocene superiore, e correlarsi, quindi, per alcuni casi particolari, con l’unità che romano et al., (1994) posizionano al di sopra dei sedimenti tirreniani nella piana del volturno. cronologicamente la presenza di fig. 4 suddivisione schematica dei settori a, b, c1 e c2. schematical subdivision sectors a, b, c1 and c2). f. aprile, a. sbrana & r.m. toccaceli questo deposito contraddice ulteriormente la tesi avanzata da brocchini et al., (2001) che escludono attività vulcanica nella zona vesuviana della piana precedenti alla messa in posto della ic. il mancato rinvenimento in questo settore della ignimbrite di taurano tranne che probabilmente per una piccola estensione lungo il citato tratto pomigliano d’arco-marigliano in corrispondenza di analoghe profondità di sondaggio nel settore a), si ritiene addebitabile, come già affermato in precedenza, ad una attività tettonica post ignimbrite di taurano che ne ha determinato il dislocamento in profondità al passaggio tra i due settori. settori c1) e c2): nella parte più settentrionale del settore c1 risulta ampiamente rappresentata la formazione del tufo grigio campano sia in affioramento (lungo il versante meridionale del mt. massico e verso i rilievi bordieri verso caserta), che nel sottosuolo, per poi scomparire in corrispondenza del graben della foce del volturno per motivi tettonici e/o spinti processi erosivi; è possibile il rinvenimento di lembi relitti così come ricostruito con i sondaggi lungo la sezione 1 di figura 4, nei pressi del canale agnena. nella zona costiera, prossima al lago patria e alla foce di licola il tetto del tufo grigio si presenta con dislocazioni di varia entità per gli effetti di una tettonica post 39 ka b.p. (aprile et al.,1992). lungo alcuni settori costieri, al di sotto del tufo grigio campano si rinvengono, così come accertato da barra et al., (1996), anche depositi marini correlati con la risalita glacioeustatica interstadiale dello stage isotopico 3. per quanto concerne il settore c2 l’andamento del tufo grigio campano è particolarmente articolato; difatti, procedendo parallelamente alla linea di costa, se ne constata la scomparsa sia in corrispondenza del fosso di volla che alla foce del sarno, anche in questo caso, per cause tettoniche e spinti processi di erosione, per poi riapparire, al sotto dell’edificio vulcanico del somma vesuvio ove il suo letto si ritrova alla profondità di circa –120 metri al sotto del livello marino attuale (brocchini et al., 2001; aprile & toccaceli, 2002). conclusioni l’analisi dei dati stratigrafici provenienti dai sondaggi meccanici finora disponibili e la rielaborazione critica degli stessi alla luce delle nuove conoscenze vulcanologiche, unitamente alla applicazione di una rigorosa ricostruzione dell’assetto geometrico-strutturale delle unità riconosciute nella definizione complessiva dell’architettura del sottosuolo della piana campana per profondità significative, consentono di affermare quanto segue: e’ stata riconosciuta una prima analogia stratigraficostrutturale, nel sottosuolo, lungo la direttrice sarnocicciano-nola-cancello lungo la fascia pedemontana di raccordo tra i l margine interno della piana campana ed i rilievi cartonatici bordieri. viene confermata, quindi, la presenza, al di sotto della ignimbrite campana, di un'altra unità piroclastica, in facies di tufo giallo litoide, costantemente presente nel sottosuolo, correlabile con l’ignimbrite di taurano (~ 157 ka b.p). le analisi che sono state condotte su tutta l’area hanno infine permesso di verificare altre analogie in ambiti sempre più prossimi alla linea di costa attuale procedendo dai rilievi carbonatici bordieri secondo una direzione ne-sw. tali analogie e la relativa discriminazione nel contesto stratigrafico-strutturale complessivo, hanno consentito di individuare una serie di settori (a, b, c1, c2) disposti secondo una direzione nw-se (appenninica) che evidenziano caratteri evolutivi differenziati; ciò non toglie che anche lungo lo sviluppo dei singoli settori siano presenti condizioni stratigrafiche e strutturali tali da definire una differenziazione in direzione nw-se. a partire dai rilievi bordieri e procedendo verso il centro della piana l’unità più antica rinvenuta nei sondaggi, risulta essere costituita da sedimenti marini quanto meno attribuibili al tardo pleistocene medio o anche più antichi se si considera la presenza di sedimenti marini del tardo plio-pleistocene rinvenuti da altri autori lungo la dorsale di avella. la ricostruzione cronostratigrafica eseguita per questo settore di pianura porta a ritenere che la piana campana sia stata interessata da subsidenza già a partire dal tardo pleistocene medio, se non prima, e non solo nel pleistocene superiore come finora ritenuto. i depositi marini rinvenuti al di sotto della ignimbrite di taurano, assumono, quindi, il ruolo di una vera e propria unità di riferimento utile per la correlazione cronostratigrafica dei sedimenti che si rinvengono a letto e a tetto; tale unità, procedendo progressivamente verso la linea di costa, già a partire dai settori centrali della piana campana, non viene più rinvenuta nei sondaggi, ed in ogni caso, alle medesime profondità riscontrate lungo il settore pedemontano, verosimilmente, per gli effetti connessi con una tettonica post 157 ka b.p. in nessuno dei settori considerati sono stati rinvenuti, nel sottosuolo, depositi da flusso piroclastico aventi tipologia tale da essere attribuiti alle altre due ignimbriti pre ic (ignimbriti di durazzano e di seiano), la cui presenza quindi, allo stato attuale della ricerca, rimane circoscritta sul versante orientale dei monti di caserta e nel vallone di seiano in penisola sorrentina rispettivamente. vengono confermati gli effetti sulla ignimbrite campana di una tettonica post 39 ka b.p. che determina dislocamenti del tetto di varia entità, particolarmente evidenti lungo la fascia più prossima alla costa (zona del lago patria, foce di licola, foce sarno, complesso del somma-vesuvio). viene identificata nel sottosuolo dei settori centrali della piana campana, una unità vulcanica, la cui posizione stratigrafica, relativamente alle ignimbriti campana e di taurano, ne definisce una collocazione cronostratigrafica nell’intervallo 157-39 ka b.p. la stessa, procedendo verso la linea di costa, si interfaccia, in modo ancora non chiarito definitivamente, con i sedimenti marini del pleistocene superiore. tali constatazioni inducono a correlare l’unità appena descritta con quelle vulcaniche flegree pre-ignimbrite campana che affiorano estesamente nei settori non collassati dei campi flegrei, nell'area urbana di napoli, dei camaldoli, di monte di procida , cuma etc. allo stato attuale della ricerca, tuttora in corso, si constata che l’evoluzione recente della piana campana è stata caratterizzata , procedendo da ne verso sw, da marcati e talora differenziati fenomeni di subsidenza. 553il ruolo dei depositi piroclastici ... lavori citati aprile f. & ortolani f. (1978) nuovi dati sulla struttura profonda della piana campana a sud est del fiume volturno. boll. soc. geol. it., 97, 591-608. aprile f. & ortolani f. (1985) principali caratteristiche stratigrafiche e strutturali dei depositi superficiali della piana campana. boll. soc. geol. it., 104, 195-206. aprile f., castaldi v., ortolani f., pagliuca s. & rolandi g. (1992) tettonica e vulcanismo negli ultimi 35.000 anni nella piana campana . atti 11° convegno g.n.g.t.s. roma, 9 – 11 dic.1992, 425-429. aprile f. & toccaceli r. m.( 2002) nuove conoscenze sulla stratigrafia e distribuzione dei depositi ignimbritici quaternari nel sottosuolo della piana del sarno (salerno-campania) italia meridionale. il quat. 15 (2),169-174 barberi f., innocenti f., lirer l., munno r., pescatore t. & santacroce r. (1978) the campanian ignimbrite: a major prehistoric eruption in the neapolitan area (italy). bull. volcanol. 41 (1), 1-22. barra d., santo a., campajola l., roca v. & tuniz c.(1996) the versil ian trasgression in the volturno river plain (campanian, southern italy). palaeoenvironmental history and chronological data. il quaternario 9 (2), 445-458 bellucci f., santangelo n., santo a. (2003) segnalazione di nuovi depositi piroclastici intercalati alle successioni continentali del pleistocene superiore-olocene della porzione nord-orientale della piana campana. il quaternario 16 (2), 279287 brancaccio l., cinque a., romano p., rosskopf c., russo f., santangelo n. & santo a.(1991) geomorphology and neotectonic evolution of a sector of the tyrrhenian flank of the southern apennines (region of naples, italy). z. geom. 82, suppl. bd., 47-58 brocchini d., principe c., castradori d., laurenzi m.a. & gorla l. (2001 )quaternary evolution of the southern sector of the campanian plain and early somma-vesuvio activity: insights from the trecase well. mineralogy and petrology 73, 67-91 bruno g., cippitelli g., rapolla a. (1998) seismic study of the mesozoic carbonate basament around mt. somma – vesuvius, italy. journal of volcanology and geothermal research 84, 311322. cassano e. & la torre p. (1987) geophysics in somma-vesuvius. quaderni della ricerca scientifica, cnr, 8, 175-196. cinque a. (1991) la trasgressione versiliana nella piana del sarno (campania). geogr. fisica e dinamica quaternaria, 14, (1), 63-71. cinque a., patacca e., scandone p., tozzi m. (1993) quaternary kinematic evolution of the southern appennines. relationship between surface geological features and deep lithospheric structures. ann. geofis. 36 (2), 249-259 de vivo b., rolandi g., gans p.b., calvert a., bohrson w.a., spera f.j., h.e. (2001) new constraints on the pyroclastic eruptive history of the campanian volcanic plain (italy). mineralogy and petrology, 73, (1-3), 47-65. di girolamo p.(1968) petrografia dei tufi campani: il processo di pipernizzazione (tufo-tufo pipernoide-piperno). rend. acc. sc. fis. matem. in napoli. serie 4, xxxv, 1-70. di girolamo p.(1970) differenziazione gravitativa e curve isochimiche nella ignimbrite campana. rend. soc. it. mineral. petrol. 26 (2), 547-588. di girolamo p. (1978) geotectonic setting of miocene quaternary volcanism in and around the eastern tyrrhenian sea border (italy) as deduced from major element geochemistry. bull. volcanol. 41, 349-413 di girolamo p., ghiara m.r., lirer l., munno r ., rolandi g. & stanzione d. (1984) vulcanologia e petrologia dei campi flegrei. boll. soc. geol. it., 103, 349-413 finetti i. & morelli c. (1974) esplorazione sismica a riflessione dei golfi di napoli e pozzuoli. boll. geofis. teorica appl. 16, 175-222 fisher r., orsi g., ort m., heiken g. (1993) mobility of a large volume pyroclastic flow-emplacement of the campanian ignimbrite, italy. j. volcanol. geotherm. res. 56, 205-220 ietto a. & sgrosso i. (1963) formazioni marine pliopleistoceniche nei dintorni di cicciano-nola). boll. soc. nat. in napoli. tornata del 28/06/1963 ippolito f., ortolani f., russo m. (1973) struttura marginale tirrenica dell’appennino campano: reinterpretazione di dati di ricerche di idrocarburi. mem. soc. geol. it., 12, 228-249. lirer l., luongo g., scandone r. (1987) on the volcanological evolution of campi flegrei. eos, trans. am. geophys. union, 68, 226-334. narcisi b. (1994) tefracronologia in aree non vulcaniche: principi, metodi di indagine e stato dell’arte nel contesto italiano. il quaternario, 7, (2), 545554.,470 nicotera p. & civita m. (1969) indagini idrogeologiche per la captazione delle sorgenti di s. marina (sarno). mem. ist. geol. appl. napoli, 11, 25-44. orsi g., civetta l. & valentine g.a. (1999) volcanism in the campi flegrei. j. volcanol. geotherm. res. 91 rolandi g., bellucci f., heizler m.t., belkin h.e & de vivo b. (2003) tectonic controls on the genesis of ignimbrites from the campanian volcanic zone, southern italy. mineralogy and petrology 79, 3-31 romano p., santo a. & voltaggio m. (1994) l’evoluzione geomorfologia della pianura del f. volturno (campania) durante il tardo quaternario (pleistocene medio-superiore-olocene. il quat., 7 (1), 41-56 rosi m. and sbrana a. (editors).(1987) the phlegrean fields. quaderni della ricerca scientifica, cnr, 114, 9,175. scandone r., bellucci f., lirer l.& rolandi g. (1991) the structure of the campanian plain and the activity of the neapolitan volcanoes (italy). j. volcanol. geotherm. res. 48,1-31. 554 ms. ricevuto il 21 maggio 2004 testo definitivo ricevuto il 2 novembre 2004 ms. received: may 21, 2004 final text received: november 2, 2004. f. aprile, a. sbrana & r.m. toccaceli imp.giraudi evoluzione tardo-olocenica del delta del tevere carlo giraudi enea c.r. casaccia, c.p. 2400, 00100 roma a.d. riassunto: c. giraudi, evoluzione tardo-olocenica de delta del tenere. it issn 0394-3356, 2004 il delta del tevere è stato studiato dal punto di vista morfologico con l’uso di fotografie aeree di tre diversi voli e con indagini di campagna nell’area dell’antico stagno di maccarese. l’esame morfologico ha permesso di stabilire che vi sono gruppi di cordoni litorali che costituiscono otto insiemi omogenei: questi possono essere seguiti sia nella zona settentrionale che meridionale del delta. la datazione dei cordoni litorali è stata ottenuta sia grazie alla presenza di costruzioni e manufatti antichi sui cordoni stessi, sia attraverso la datazione dei sedimenti presenti nelle depressioni alle spalle dei cordoni litorali. i gruppi di cordoni litorali affioranti al piano campagna indicano otto fasi di avanzamento del delta: la prima fase è più antica di circa 3700-4000 anni a.c.; la seconda più antica di 32752930 anni a.c.; la terza ha età prossima a 3275-2930 anni a.c.; la quarta ha età compresa tra 2140-1920 a.c. e 1300-1000 a.c.; la quinta ha età prossima a 910-800 anni a.c.; la sesta ha un’età compresa tra il iv secolo a.c. ed il x secolo d.c.; la settima e l’ottava fase sono databili al periodo compreso tra il xv ed il xix secolo. l’esame dell’andamento dei cordoni litorali ha permesso di stabilire che almeno fino al ix secolo a.c. la foce del tevere era situata in corrispondenza dell’attuale alveo di fiumicino: solo tra viii e iv secolo a.c. il fiume subì una diversione verso l’attuale foce. il delta ha subito anche varie fasi di arretramento, avvenute negli intervalli tra la sedimentazione dei cordoni litorali della prima e della seconda fase (età maggiore di 3275-2930 a.c.), tra quinta e sesta fase (età compresa tra viii e i secolo a.c.), nel corso della sesta fase (iii secolo d.c.), e l’ultima, quella morfologicamente più evidente, successiva ai cordoni della sesta fase, databile al medioevo (x-xiii secolo). sensibili arretramenti della linea di costa, devono essere avvenuti anche tra 6000 e 2000 anni fa a causa della risalita eustatica del livello del mare: porzioni, anche estese, dei gruppi di cordoni litorali debbono quindi essere state erose o giacere coperte da sedimenti più recenti. i cordoni litorali formati nel corso della forte avanzata del delta che avvenne a partire dal xv secolo occupano un’estensione maggiore di quella di tutti i cordoni di età più antica. questo fatto non implica che il loro sviluppo sia eccezionale: i cordoni litorali più recenti potrebbero essere più estesi solo perché conservati nella loro interezza. e’ stato rilevato che nell’area ad est di focene i cordoni litorali hanno subito vari sfondamenti nel corso del tempo: il primo dopo 3275-2930 anni a.c., il secondo in un periodo successivo a 910-800 anni a.c. e precedente al vii secolo a.c., il terzo nel corso, probabilmente, del i secolo d.c. in particolare, il secondo sfondamento ha permesso l’ingressione di acqua salata nelle paludi di acqua dolce dello stagno di maccarese che esistevano almeno dal 5300-5200 a.c. nell’area di vignole, sono stati poi individuate tracce di alvei originatisi per la rottura degli argini naturali del tevere e ventagli di crevassa, che possono essere datati attorno al ix e x secolo a.c. nell’area di maccarese e di le pagliete sono stati individuati i resti di due canali artificiali di età romana che suggeriscono, insieme ai manufatti presenti a campo salino, un tentativo di gestione complessiva delle paludi presenti nell’area settentrionale del delta. dal confronto tra l’evoluzione del delta, la frequenza degli eventi alluvionali del tevere a roma, le fasi climatiche registrate in appennino (dedotte dalle variazioni del ghiacciaio del calderone, dei laghi fucino e trasimeno, e dallo studio delle alluvioni oloceniche di campo imperatore) è emerso chiaramente che le fasi di progradazione del delta sono coeve con fasi climatiche più fredde (avanzate del ghiacciaio del calderone) e umide (aumento di livello dei laghi), mentre le fasi di arretramento della costa sono correlabili a periodi più caldi caratterizzati da sviluppo dei suoli in alta montagna e ritiro del ghiacciaio del calderone. l’evoluzione del delta, seppure condizionato da interventi antropici, appare essenzialmente influenzata dall’evoluzione climatico-ambientale dell’appennino. infine è stato ipotizzato che l’asimmetrico sviluppo dei cordoni litorali a nord e a sud dell’area dei porti imperiali sia dovuto ad un diverso grado di subsidenza. anche se limitata, nel corso del tempo la subsidenza avrebbe influenzato l’evoluzione della linea di costa: si sarebbe formata una discontinuità nei cordoni litorali nell’area a nord del ramo di fiumicino, favorendo la formazione di un piccolo golfo, nelle adiacenze del quale vennero scavati i bacini e costruite le infrastrutture del porto di claudio. abstract: c. giraudi, late holocene evolution of the tiber delta it issn 0394-3356, 2004 the tiber delta has been studied using aerial photographs taken in three different flights in order to recognize geomorphological features, and with field surveys in the area of the ancient stagno di maccarese marshes.morphological studies have shown that there are groups of beach ridges forming eight homogeneous complexes that can be followed both in the northern and in the southern part of the delta. dating of these beach ridges has proved possible thanks to the presence of buildings and artefacts on the ridges and through dating of the sediments in the depressions behind the ridges. the groups of outcropping beach ridges indicate eight phases of delta advance: the first phase is older than 3700-4000 years bc; the second one is older than 3275-2930 years bc; the third one is dated about 3275-2930 years bc; the age of the fourth one is between 2140-1920 bc and 1300-1000 years bc; the fifth one is dated about 910-800 years bc; the age of sixth one is between the 4th century bc and the 10th century ad; and the seventh and eighth phases are dated between the 15th and the 19th century ad. examination of the beach ridges has established that at least until the 9th century bc the mouth of the tiber was situated where the present fiumicino channel runs. it was only between the 8th and the 4th century bc that the river became diverted to its present bed. the delta has also undergone various retreat phases, which occurred between the sedimentation of the beach ridges of the first and second phase (age greater than 3275-2930 years bc), between the fifth and the sixth phase (age between 8th and 1st century bc), during the sixth phase (3rd century ad), and the morphologically most evident one, after the sixth phase ridges, dated from the middle ages (10th-13th century). appreciable retreat of the coastline must also have taken place between 6000 and 2000 years ago due to the eustatic rise in sea level, and parts – even extensive ones – of the groups of beach ridges must therefore have been eroded or overlain by more recent sediments. the beach ridges formed during the significant advance of the delta that took place as from the 15th century occupy an area perhaps even greater than that of all the earlier ridges. this fact does not imply that their development is exceptional: the most recent beach ridges might be more extensive only because they have been entirely preserved. it has been observed that in the area to the east of focene the beach ridges have been broken up a number of times: the first time after 3275-2930 years bc, the second time in a period after 910-800 years bc and before 7th century bc, and the third time probably during the 1st century ad. in particular, the second break-up enabled salt water to flow into the stagno di maccarese freshwater maril quaternario italian journal of quaternary sciences 17(2/2), 2004, 477-492 478 c. giraudi 1 introduzione e metodo di studio l’area deltizia del tevere, attualmente fortemente antropizzata per la presenza di centri abitati e quartieri di roma, vie di comunicazioni, l’aeroporto di fiumicino, ecc., presentava un aspetto ancora molto diverso nel corso del xix secolo e dell’inizio del xx secolo. sia a nord che a sud dell’alveo fluviale si estendevano grandi aree palustri, circondate da pascoli, che venivano parzialmente sommersi durante il periodo invernale, e da boschi, secondo quanto rappresentato sulle carte di amenduni (1884). la zona venne poi bonificata con interventi che durarono dal 1889 fino agli anni ’30 del xx secolo, colonizzata e sottoposta a coltivazione intensiva. l’evoluzione del delta è stata oggetto di vari studi, a partire dalla seconda metà del xix secolo (oberholtzer, 1875; bocci, 1892). la maggior parte dei lavori moderni riguarda principalmente lo studio sedimentologico dei depositi tardo pleistocenici ed olocenici che formano il delta, messi in evidenza da molti sondaggi effettuati specialmente all’interno del perimetro dell’aeroporto internazionale leonardo da vinci di fiumicino (dragone et al., 1967; belluomini et al. 1986; bellotti et al., 1987; bellotti et al. 1989,1994, 1995; chiocci & milli, 1995; amorosi & milli, 2001). in vari lavori sono state presentate ricostruzioni areali dell’evoluzione del delta nel corso del tempo basate sui dati geologici e su informazioni storiche, ed avanzate ipotesi sulla posizione delle linee di riva in varie epoche, a partire dal periodo romano (belluomini et al. 1986; bellotti et al., 1987; bellotti et al. 1989,1994,1995). il metodo utilizzato nel presente lavoro è stato sia geomorfologico che stratigrafico. sono state rilevate da foto aeree le caratteristiche e la distribuzione dei cordoni litorali su tutta l’area del delta in modo da evidenziarne l’evoluzione e verificare gli spostamenti di alveo del tevere avvenuti nel corso del tempo. l’area è stata studiata utilizzando fotografie scattate da aerostato nel 1911, immagini aeree della raf del 1943 e fotogrammi del volo base italiano del 1954. i dati emersi dalle indagini fotogeologiche sono stati riportati su carte di base a scala 1:25.000: queste permettono di valutare con buon dettaglio l’andamento dei cordoni litorali e le morfologie relative agli spostamenti nella foce del tevere. poichè l’area studiata è piuttosto estesa, nel presente lavoro gli elementi morfologici sono stati riportati a scale molto più piccole in due figure (fig. 1 e 2) di diverso dettaglio. oltre alle indagini fotogeologiche sono state condotte indagini stratigrafiche sui sedimenti di due aree, un tempo occupate dalle paludi dello stagno di maccarese, ubicate alle spalle dei cordoni litorali nelle zone di maccarese e di campo salino. tali indagini hanno permesso di ottenere elementi di datazione di varie fasi evolutive dello stagno. l’evoluzione delle paludi, come si vedrà oltre, è stata condizionata dallo sviluppo dei cordoni litorali e quindi dalle fasi di costruzione del delta. si è inoltre fatto ricorso a dati storici e a fonti latine, riportati in bibliografia, che si sono rivelati utili per le informazioni relative alle caratteristiche del delta, agli interventi sull’alveo ed al regime idraulico del tevere. la datazione di insediamenti, manufatti e opere permette anche di trarre utili indicazioni sull’estensione del delta nei tempi antichi. nel presente lavoro è stata quasi completamente trascurata la parte relativa all’evoluzione del delta negli ultimi 600 anni, in quanto l’argomento è già stato affrontato ed approfondito da innumerevoli lavori che, a partire da oberholtzer (1875) e bocci (1892), hanno datato le fasi di progradazione del delta utilizzando le date di costruzione di varie torri di difesa costruite nei pressi della foce del tevere in avanzamento. 2 morfologia e stratigrafia tardo-olocenica del delta il fiume tevere nell’area del delta risulta formato da due rami: il ramo principale, detto fiumara grande, sbocca nel mare a nw del lido di ostia, mentre il ramo secondario, più settentrionale, sbocca in mare presso fiumicino. secondo fonti latine (riportate in bellotti et al. 1994) il ramo di fiumicino, sarebbe stato scavato artificialmente nel ii secolo d.c., in corrispondenza della costruzione del porto di traiano. attualmente il delta del tevere ha un aspetto piuttosto simmetrico, con una evidente cuspide principale in corrispondenza dello sbocco in mare del ramo principale ed una cuspide assai meno pronunciata in corrishes, which have existed at least since 5200-5300 bc. in the vignole area, traces of channels produced by the breaking of the natural banks of the tiber have been found, as well as series of crevasses, which may be dated at around the 9th and 10th century bc. in the maccarese and le pagliete area, the remains of two artificial canals of roman age have been identified, suggesting, together with artefacts found at campo salino, an attempt at the overall management of the lagoon in the northern area of the delta. comparing the evolution of the delta, the frequency of flood events in the tiber at rome, and the climatic phases recorded in the apennines (deduced from the variations in the calderone glacier, in lakes fucino and trasimeno level oscillations, and from the study of holocene alluvial deposits at campo imperatore), it has emerged clearly that the delta progradation phases are coaeval with the cooler (advances of the calderone glacier) and wetter (increase in level of the lakes) climatic phases, while the phases of coastal retreat can be correlated with warmer periods characterized by the development of high mountain soils and the retreat of the calderone glacier. the evolution of the delta, although affected by anthropic measures, appears to have been essentially conditioned by the climatic-environmental evolution of the apennines. lastly, the hypothesis has been made that the asymmetric development of the beach ridges to the north and south of the area of the claudius and trajan ports was due to a different degree of subsidence. however limited, in the course of time this subsidence has influenced the evolution of the coastline: it probably favoured the formation of a discontinuity of the beach ridges in the area north of the fiumicino branch, helping to form a small inlet in which the port of claudius was constructed. parole chiave: olocene, delta del tevere, cordoni litorali, variazioni linea di costa, clima. keywords: holocene, delta of the river tiber, beach ridges, coastline variations, climate. 479evoluzione tardo olocenica ... fig. 1 il delta del tevere: elementi morfologici ed estensione dei cordoni litorali delle otto fasi the tiber delta: morphological features and extent of the beach ridges spondenza dello sbocco del ramo di fiumicino (fig. 1). come evidenziato da bellotti et al. (1995), morfologicamente il delta presenta una piana deltizia inferiore, costituita prevalentemente da cordoni litorali, mentre nella piana deltizia superiore, alle spalle dei cordoni litorali, sono presenti aree depresse che, prima della bonifica, erano occupate da paludi. nel tratto in cui attraversa la piana deltizia interna, il tevere scorre al centro di una larga fascia di alluvioni; esso separa così le aree depresse in una zona setten480 trionale, che un tempo ospitava lo stagno di maccarese, ed una meridionale, che ospitava lo stagno di ostia. altri stagni minori erano presenti nella zona dei porti imperiali e tra i cordoni litorali. le due paludi più estese furono collegate al mare da emissari artificiali, scavati nel corso di tentativi di bonifica precedenti a quello moderno: tali canali sfociano in mare presso focene, a nord di fiumicino e nella zona del lido di ostia. nella parte settentrionale del delta è presente la foce del fiume arrone, che interrompe i cordoni litorali e separava, nel passato, le paludi de le pagliete dalla palude di maccarese. l’andamento dei cordoni litorali, esaminato e cartografato in dettaglio, ha permesso di distinguere vari insiemi di cordoni litorali: ogni insieme può essere considerato come parte di una stessa fase di progradazione del delta. i cordoni litorali di una stessa fase presentano caratteri morfologici comuni: direzione, continuità laterale, elevazione delle dune, grado di conservazione, ecc.; in prossimità della foce del fiume sovente risultano separati dai precedenti e dai successivi per la presenza di fasce depresse strette ed allungate impostate su sedimenti di spiaggia, palustri o alluvionali. di particolare interesse è stata poi la constatazione che i cordoni litorali di alcune fasi tagliano quelli di fasi precedenti: tale situazione morfologica dimostra l’esistenza di periodi di arretramento della linea di costa. sia il dettaglio nel ricostruire l’andamento dei cordoni litorali, sia l’esame di fotografie aeree relative a diversi periodi, sia l’uso di dati stratigrafici per la datazione dei cordoni litorali hanno permesso di ottenere un quadro molto più complesso dell’evoluzione tardo-olocenica del delta rispetto a quanto ipotizzato fino ad ora. 2.1 i cordoni litorali e la loro datazione la geometria dei cordoni litorali è già stata parzialmente evidenziata da dragone et al. (1967) sul foglio geologico a scala 1:100.000 cerveteri della carta geologica d’italia. in bellotti et al., (1994) l’andamento dei cordoni litorali è stato rappresentato schematicamente a scala molto piccola. nel corso del presente lavoro sono stati distinti otto gruppi di cordoni litorali: i più interni sono, evidentemente, i più antichi. in fig. 1 sono cartografati i vari gruppi omogenei di cordoni litorali, ma la loro rappresentazione cartografica è semplificata per problemi di scala. una rappresentazione più dettagliata della porzione centrale del delta è riportata in fig. 2. la prima fase di formazione di cordoni litorali è testimoniata da due fasce di dune poco estese presenti sia a nord che a sud del tevere. la seconda fase è rappresentata da un gruppo di cordoni abbastanza esteso, presente sia a nord che a sud del tevere. i cordoni scompaiono avvicinandosi al fiume in quanto risultano coperti da sedimenti alluvionali o erosi. un lembo di questo gruppo di cordoni è stato individuato nella zona dove i l ramo di fiumicino si distacca dall’alveo principale ed appare situato sulla prosecuzione verso nw dei cordoni meridionali. osservando l’andamento quasi rettilineo dei cordoni litorali di questa fase a nord e a sud del tevere è possibile notare che essi non risultano allineati e che i cordoni meridionali sono più avanzati verso il mare. non si rilevano indizi di una cuspide, ma lo sbocco in mare del tevere deve essere stato in corrispondenza o poco a nord dei porti di claudio e di traiano. non si hanno elementi di datazione diretta di tali cordoni. i cordoni litorali della terza fase sono rappresentati estesamente a nord e a sud del tevere, anche se sono parzialmente erosi e coperti da sedimenti alluvionali più recenti. anche in questo caso l’andamento dei cordoni litorali è rettilineo, ma i cordoni posti a nord e a sud del fiume non risultano allineati e quelli meridionali sono più avanzati verso il mare. non sono state rilevate tracce di cordoni indicanti una cuspide, tuttavia la evidente discontinuità tra i cordoni indica che la foce del tevere doveva essere situata nella zona dei porti imperiali. non si hanno elementi di datazione diretta di questi cordoni. i cordoni litorali della quarta fase sono estesi a nord e a sud del tevere, ma conservano una cuspide evidente ai margini del ramo di fiumicino, nei pressi dei porti imperiali. lo sbocco in mare del tevere doveva avvenire in questa zona. la porzione meridionale della cuspide non presenta però continuità col ramo settentrionale dei cordoni litorali di questa fase ed appare più avanzata verso mare. i cordoni di questa fase possono essere datati ad un periodo precedente l’età del bronzo recente (circa xiii-xi secolo a.c.): manufatti di tale età sono stati infatti rinvenuti negli scavi delle terme di nettuno nella città romana di ostia (zevi, 1968, in conti, 1982), che giace su tali sedimenti. i cordoni litorali della quinta fase sono assai meno estesi sia a nord che a sud del tevere, per il resto mostrano un andamento del tutto simile a quelli della quarta fase: si riconosce una cuspide nella zona del ramo di fiumicino presso i porti imperiali; non c’è continuità tra la porzione settentrionale della cuspide e il ramo settentrionale dei cordoni della stessa fase poiché la cuspide appare più avanzata verso mare. sui cordoni litorali di questa fase sono fondati i resti del faro romano sui quali è costruita la torre boacciana, immediatamente ad ovest della città romana di ostia. un molo del porto di claudio, databile verso la metà del i secolo d.c. è ancorato ai cordoni litorali della quinta fase e appena a nord del porto, i cordoni di questa fase sono tagliati da un canale, ora colmato, collegato alle opere eseguite al contorno del porto di claudio (testaguzza, 1970). inoltre tali cordoni litorali debbono essere datati ad un periodo precedente il iv secolo a.c. in base alle considerazioni riportate di seguito. il tevere subì una diversione verso sud dopo la fine della quinta fase, e la sua foce migrò nella zona di ostia antica (vedasi oltre). poiché secondo le fonti storiche la città romana di ostia venne fondata alla foce del tevere all’inizio del iv secolo a.c., la diversione del tevere dalla zona dei porti imperiali verso sud deve essere avvenuta prima del iv secolo. ne consegue che i cordoni litorali della quinta fase debbono essere più antichi del iv secolo a.c. i cordoni della sesta fase sono poco estesi a sud del tevere, occupano una fascia molto stretta nella zona dei porti imperiali, ma si espandono molto a nord. l’andamento dei cordoni mostra caratteristiche assai diverse da quelli precedenti: vi è una cuspide ben c. giraudi 481evoluzione tardo olocenica ... fig. 2 – geologia della porzione centrale del delta del f. tevere. legenda:i. ii. iii. iv. v. vi. vii, viii = cordoni litorali dalla prima alla ottava fase; sp= sedimenti prevalentemente palustri; sa= sedimenti prevalentemente alluvionali; asp= sedimenti alluvionali o di spiaggia o palustri, delle aree comprese tra cordoni litorali di diverse fasi; p= paleoalvei del tevere; t.lgm= depressione della valle del tevere durante l'ultimo massimo glaciale; rav= alvei e ventagli di crevassa di le vignole; rpc= depositi di riempimento del porto di claudio; a= aree antropizzate in antico (città, porti, accumuli antropici di sabbia. le linee isopache si riferiscono allo spessore dei sedimenti deltizi posteriori all'ultimo massimo glaciale (ridisegnato dalla fig. 3 di bellotti et al. 1995). i quadrati neri indicano le torri costiere e la data di costruzione. geology of the central portion of the tiber delta. legend: i. ii. iii. iv. v. vi. vii, viii = beach ridges from the first to the eighth phase; sp= mainly marshy sediments; sa= mainly alluvial sediments; asp= alluvial or beach or marshy sediments, in the areas between beach ridges of various phases; p= ancient stream bed of the tiber; t.lgm= tiber valley depression during the last glacial maximum; rav= stream beds and crevasse splays of le vignole; rpc= deposits in the claudius harbor; a= areas of human settlement in roman times (towns, ports, buildings anthropic sand accumulations). the isopach lines refer to the thickness of the delta sediments after the last glacial maximum (redrawn from the fig. 3 by bellotti et al. 1995). the black squares mark the coastal towers and their age. 482 riconoscibile in corrispondenza del ramo principale del tevere, poco a ovest di ostia antica. nella zona dei porti imperiali i cordoni litorali della sesta fase tagliano quelli precedenti e, anche se conservano una forma cuspidata, la loro morfologia sembra causata da un adattamento alla forma dei cordoni più antichi. a differenza di quelli delle fasi precedenti e successive, l’estensione dei cordoni litorali varia moltissimo: sono poco estesi e formano una fascia ristretta a sud della foce del tevere, ma sono molto allungati e danno luogo ad una fascia molto più larga verso nord. secondo plinio il vecchio (in bellotti et al. 1994), il delta avrebbe formato una cuspide solo nel corso del i secolo a.c.; virgilio e plutarco segnalano, rispettivamente, l’abbondanza del trasporto di sabbia alla foce del tevere ed il parziale insabbiamento della foce nel i secolo a.c. osservando la zona appena a nord dei porti imperiali (fig. 2) è possibile rilevare che i più antichi cordoni di questa fase sono tagliati dalla porzione terminale di un canale, ora colmato, che secondo testaguzza (1970) sarebbe collegato alle opere eseguite al contorno del porto di claudio; il canale è databile alla metà del i secolo d.c. la porzione più antica dei cordoni litorali della vi fase deve quindi essersi sviluppata a partire da un momento successivo al iv secolo a.c. (dal i sec. a.c. secondo plinio il vecchio) ed essere precedente ai lavori del porto di claudio, databili verso la metà del i sec d.c. una parte dei cordoni litorali di questa fase appoggia sul lato esterno di un molo del porto di claudio, ma appare tagliata da una depressione lunga e stretta (apparentemente un canale che metteva in comunicazione il bacino del porto di claudio con il mare). i cordoni della porzione intermedia della sesta fase chiudono invece la suddetta depressione: secondo testaguzza (1970), che interpreta alcuni dati archeologici, la chiusura del canale che usciva dal porto di claudio sarebbe avvenuta nel vi secolo d.c. secondo bellotti et al. (1994), autori romani segnalano che nel corso del iii secolo dovettero essere eseguite opere di protezione della via severiana (che correva a sudest di ostia antica, nella parte meridionale del delta) danneggiata dalle onde; questo implica che la formazione dei cordoni della sesta fase non è stata continua, ma interrotta almeno da un periodo di regressione della linea di costa. i cordoni della settima fase sono presenti solamente nella zona centrale del delta. la loro forma indica, in grande, una cuspide in corrispondenza dell’alveo principale, ma al centro di tale cuspide i cordoni rientrano verso terra, tagliando quelli della fase precedente. anche nella zona dei porti imperiali tali cordoni tagliano i precedenti. i cordoni litorali della sesta fase debbono quindi essere stati erosi a seguito di un forte arretramento della linea di costa avvenuto prima dell’inizio della sedimentazione dei cordoni litorali della settima fase. i cordoni litorali di questa fase testimoniano un avanzamento della linea di riva rispetto alla posizione di torre boacciana, che all’inizio del xv secolo giaceva ancora in prossimità della riva del mare (belluomini et al . 1986; bellotti et al ., 1987,1989,1994,1995). sui cordoni litorali della stessa fase è costruito il forte di paolo iv databile al 1557. i cordoni litorali della settima fase possono quindi essere datati ad un periodo compreso tra il xv secolo e la prima metà del xvi secolo. i cordoni che indicano l’ottava ed ultima fase di avanzamento del delta costituiscono un insieme, molto esteso arealmente e complesso, nel quale potrebbero essere distinte varie sub-fasi, trascurate nel presente lavoro, ma evidenziate da limiti in fig. 2. nel corso di questa fase il delta avanzò molto velocemente dando luogo ad una morfologia fortemente cuspidata nella zona dell’alveo principale. in corrispondenza dell’alveo di fiumicino non vi sono indizi di cuspidi se non relativamente ai cordoni litorali più recenti. l’età di questa fase è successiva ai primi decenni del xvi secolo e le varie avanzate, ben documentate dagli autori precedenti, sono scandite (oberholtzer,1875; bocci,1892; belluomini et al. 1986; bellotti et al., 1987,1989,1994,1995) dalla costruzione di nuove torri di guardia sulle spiagge del delta in avanzamento. alla fine del xix secolo iniziò una fase di arretramento, diventata ancora più evidente verso la metà del xx secolo (bellotti, et al. 1994), che è stata contrastata con opere di difesa costiera. altri arretramenti della linea di costa erano già avvenuti nei periodi compresi tra la formazione dei cordoni della quinta e della sesta fase e tra quelli della sesta e della settima fase. per datare i più antichi cordoni litorali, non databili direttamente, è possibile ricorrere a dati stratigrafici raccolti nell’ambito delle paludi bonificate. nei pressi del sito eneolitico de le cerquete, a maccarese (fig. 1), nell’area settentrionale del delta, giraudi (2002a) ha individuato limi torbosi, posti al tetto di uno strato di torba, datati 4510±70 anni bp col metodo del 14c (data calibrata 3375-2930 a.c.) e sedimenti limosi palustri posti sopra il livello del mare (giraudi, 2002a), che sigillano il sito eneolitico attorno a 4375±55 anni b.p. (data calibrata 3140-2900 a.c., carboni et al., 2002). in quel periodo dovevano quindi essere presenti cordoni litorali, che raggiungevano quote superiori al livello del mare, in grado di impedire il deflusso dell’acqua dalle paludi. i cordoni che possono corrispondere ai sedimenti databili 3140-2900 cal. a.c. sono quelli prossimi al sito, cioè quelli della terza fase. nel lavoro di belluomini et al. (1986) sulla stratigrafia dei sedimenti che formano il delta del tevere nella zona dell’aeroporto di fiumicino, vengono riportate le datazioni di vari campioni prelevati da un livello di torba e limi torbosi presente esclusivamente alle spalle dei cordoni litorali riconoscibili in superficie; tali sedimenti hanno fornito età prossime a quelle relative al sito eneolitico di maccarese: le date ottenute sono comprese tra 5140±60 (data calibrata 4042-3792 a.c.) e 4630±60 (data calibrata 3626-3122 a.c.). la presenza di sedimenti di acqua dolce, prevalentemente organici, senza sensibili apporti terrigeni, implica che prima del 4042-3792 cal a.c. le paludi dovevano essere isolate anche dal tevere ed alimentate solo dai corsi d’acqua provenienti dalla zona collinare e dal f. arrone. i più antichi cordoni litorali affioranti in superficie sarebbero databili, quindi, a 4042-3792 cal a.c. o ad un periodo più antico. del resto gli studi geologici effettuati sul sito eneolitico delle cerquete di maccarese (giraudi, 2002a) avevano già dimostrato che le oscillazioni di livello dello stagno di maccarese, dal periodo neolitico alla media età del bronzo (quindi contemporaneamente c. giraudi e successivamente alla sedimentazione delle torbe), non erano collegati alle oscillazioni di livello del mare, ma erano ben correlabili con le oscillazioni di numerosi laghi presenti in italia centrale: doveva quindi mancare un collegamento tra lo stagno ed il mare. al di sotto delle torbe, nella zona di campo salino (vedasi oltre) sono presenti sedimenti contenenti faune dulcicole, datati 6350±40 anni b.p. (data calibrata 5380-5280 a.c. – beta 193206) col metodo del radiocarbonio. essi testimoniano che già in precedenza l’area palustre era isolata dal mare. tuttavia, non conoscendo la distribuzione areale di tali sedimenti, non è possibile stabilire se si sono deposti esclusivamente alle spalle dei cordoni litorali individuabili a livello del piano campagna (e quindi siano geneticamente legati a questi) o se sono correlati ad altri cordoni litorali attualmente non visibili in superficie. 2.1.1 i cordoni interrotti della foce del f. arrone e dell’area di focene nel tratto finale del fiume arrone e nella zona di focene sono state rilevate interessanti situazioni morfologiche (fig. 1, 2, 3). il fiume arrone (fig. 1), emissario del lago di bracciano, nel tratto in cui attraversa il depositi deltizi del tevere, si presenta come un corso d’acqua chiaramente pensile. i suoi sedimenti alluvionali si trovano a quote superiori ai depositi palustri di le pagliete e di 483evoluzione tardo olocenica ... fig. 3 ricostruzione delle fasi di modellamento e di erosione dei cordoni litorali presenti nell'area ad est di focene. legenda: i viii = cordoni litorali dalla prima alla ottava fase; apc = aree occupate da sedimenti palustri, alluvionali e colluviali; d = canali di drenaggio sedimentation and erosion phases of the beach ridges in the area east of focene. legend: i viii = beach ridges from the first to the eighth phase; apc = areas occupied by marshy, alluvial and colluvial sediments; d = drainage channels maccarese. quindi l’arrone, con i suoi depositi, ha prodotto la divisione di una palude che avrebbe potuto essere continua da le pagliete a campo salino. inoltre, grazie alla sua pensilità, il fiume ha sovralluvionato quasi tutta la serie dei cordoni litorali delle varie fasi, ad eccezione dei più recenti. le fotografie aeree mostrano tracce di vecchi alvei del fiume diretti verso lo stagno di maccarese, a testimonianza del fatto che il fiume pensile poteva rompere gli argini naturali e confluire nella palude di maccarese. una situazione morfologica di estremo interesse, mai discussa da autori precedenti, è stata, poi, rilevata nell’area ad est di focene, ove i cordoni litorali di varie fasi sono chiaramente interrotti ed erosi. esaminando l’andamento dei cordoni litorali (fig. 2), occorre rilevare che quelli compresi tra la seconda fase e la parte più antica di quelli della sesta fase, sono interrotti per un lungo tratto. i cordoni litorali successivi sono interessati solo da una stretta incisione. in corrispondenza di detta incisione i cordoni litorali della settima e della parte iniziale della ottava fase cambiano localmente il loro andamento, entrando parzialmente in essa (fig. 2). le interruzioni debbono essere state prodotte dallo sfondamento dei cordoni l itorali. osservando in dettaglio la morfologia di alcuni cordoni possiamo notare che si sono verificate varie fasi di sfondamento, che hanno aperto estesi varchi e messo in comunicazione le paludi col mare, seguite da fasi di sviluppo di nuovi cordoni litorali, che hanno nuovamente separato le paludi dal mare. un primo sfondamento dei cordoni litorali è avvenuto dopo la formazione dei cordoni della terza fase (fig.3). l’incisione venne sigillata poi dai cordoni litorali della quarta e della quinta fase che ancora sbarrano una parte del varco. un nuovo sfondamento dei cordoni litorali ebbe luogo dopo la sedimentazione dei cordoni della quinta fase: l’incisione venne poi chiusa, almeno parzialmente, dai cordoni della sesta fase, che occupano ancora attualmente una parte del varco. in seguito anche una parte dei cordoni della sesta fase fu erosa ma l’ incisione venne chiusa, almeno parzialmente, da altri cordoni formati nel corso della stessa fase. alcuni dati necessari per l’inquadramento cronologico degli sfondamenti dei cordoni litorali possono essere tratti dalla interpretazione di sequenze stratigrafiche presenti nell’area occupata, prima della bonifica, dallo stagno di maccarese. nelle trincee scavate per uno studio geo-archeologico, in collaborazione con la soprintendenza archeologica di ostia, il museo delle origini dell’università “la sapienza” di roma ed il consorzio cirf, in corso nella zona nord di campo salino, è stata rilevata la stratigrafia degli ultimi 5 metri di sedimenti palustri. la serie di sedimenti, ancora in corso di studio, coincide fondamentalmente con quelle descritte dagli autori precedenti (dragone et al., 1967; belluomini et al. 1986; bellotti et al., 1987,1989,1994,1995; chiocci & milli, 1995; amorosi & milli, 2001) ma è stata osservata con grande dettaglio con trincee molto estese: queste hanno permesso di identificare anche alcune superfici di erosione, difficilmente individuabili nelle carote prelevate con sondaggi meccanici. alla base della sequenza esaminata (fig. 4) sono presenti limi grigi con gasteropodi dulcicoli (lymnaea stagnalis, bithynia tentaculata) sui quali appoggiano limi marrone chiaro potenti circa 80 cm, ricchi di resti vegetali alla base e di gasteropodi dulcicoli (lymnaea stagnalis, bithynia tentaculata). un campione di limi ricchi di resti vegetali è stato datato col metodo del radiocarbonio ed ha fornito una età di 6350±40 anni b.p. (data calibrata 5380-5280 a.c. – beta 193206). seguono limi torbosi e torbe contenenti molti tronchi e frammenti di legno, con gasteropodi dulcicoli, gli stessi depositi datati da belluomini et al. (1986) nell’area dell’aeroporto e da giraudi (2002a) nell’area di maccarese. l’età di tali sedimenti è compresa tra circa 4042-3792 anni a.c. e 3140-2900 anni a.c.; un campione di legno proveniente dalle torbe di campo salino è stato datato ed ha fornito un’età radiocarbonio di 4360±70 bp (data calibrata 3320-2880 a.c. beta 156389), compatibile con le età ottenute sui campioni degli altri siti. 484 c. giraudi fig. 4 serie stratigrafica rilevata lungo trincee scavate a campo salino stratigraphic series surveyed along trenches dug at campo salino su torbe e limi torbosi appoggiano, tramite una netta superficie di erosione (s.e.1), argille limose grigio chiare ed un’alternanza di limi e limi argillosi grigio chiari e grigio più scuri, contenenti resti vegetali e gasteropodi dulcicoli (lymnaea stagnalis, planorbarius corneus, planorbis planorbis, bithynia tentaculata). seguono poi limi argillosi torbosi grigio-nerastri e limi grigi, contenenti gasteropodi dulcicoli (lymnaea stagnalis, bithynia tentaculata). i limi grigi, che rappresentano i sedimenti meno ricchi di sostanze organiche e più grossolani incontrati nell’area, aumentano di potenza e granulometria nella zona più vicina all’alveo del tevere: vengono quindi interpretati come sedimenti alluvionali deposti nella palude dalle acque di esondazione del tevere. una conchiglia di bithynia tentaculata, contenuta nei limi grigi, datata col metodo del radiocarbonio, ha fornito un’età di 2690±40 b.p. (data calibrata: 910-800 a.c. beta 193208). al tetto dei limi grigi è presente una netta superficie di erosione (s.e.2) sulla quale poggiano sedimenti limosi grigio-azzurrognoli, contenenti bivalvi di ambiente salmastro (cerastoderma edule, abra alba, hydrobia acuta): tra i limi con faune di ambiente salmastro sono presenti due livelli potenti pochi centimetri di limi torbosi con gasteropodi dulcicoli (planorbarius corneus, bithynia tentaculata), indice di temporanei ritorni a condizioni di palude di acqua dolce. i sedimenti descritti sono precedenti alla esecuzione di lavori per lo sfruttamento delle paludi ad opera dei romani, datati al i secolo d.c. (morelli et al., 2004). al tetto dei limi grigio azzurrognoli è presente una nuova superficie di erosione (s.e.3) sulla quale poggiano altri limi, aventi lo stesso colore dei precedenti, con faune di ambiente salmastro (cerastoderma edule, abra alba, hydrobia acuta). tali limi sono penecontemporanei e posteriori alle opere romane del i sec. d.c. visto che le età delle fasi erosive sono compatibili con quelle dei cordoni litorali erosi, si assume che le tre importanti superfici di erosione individuate siano collegate a variazioni ambientali prodotte dagli sfondamenti dei cordoni litorali. il primo sfondamento (responsabile dello sviluppo della superficie di erosione s.e.1) é quindi databile ad un periodo successivo a 3320-2880 anni a.c. ed ha prodotto l’erosione dei cordoni della iii fase, che hanno un’età prossima a 3140-2900 anni a.c. anche nella serie stratigrafica rilevata presso il sito eneolitico di le cerquete, a maccarese, é presente una superficie di erosione successiva ad una fase di pedogenesi che ha prodotto un crostone calcareo datato a 3660±40 anni radiocarbonio bp (data calibrata 2140-1920 a.c.). tale superficie di erosione ha età compatibile con la s.e.1 di campo salino e può essere coeva. assumendo che sia valida la correlazione, si deduce che i cordoni litorali della quarta fase, che più tardi hanno chiuso l’incisione, sarebbero più recenti di tale data. il secondo sfondamento (responsabile dello sviluppo della superficie di erosione s.e.2) é successivo alla sedimentazione dei limi alluvionali contenenti la data 910-800 a.c.: esso ha prodotto l’erosione dei cordoni litorali della quinta fase e permesso l’ingressione di acqua marina e lo sviluppo di una laguna salmastra. da questo dato si desume anche che i cordoni litorali della quinta fase (formatisi prima del secondo sfondamento) debbono essere penecontemporanei ai limi grigi di origine alluvionale contenenti la data di 910-800 a.c. la tradizione romana, riportata a partire da ennio (iii sec. a.c.), ricorda che la fondazione di un insediamento romano ad ostia tiberina, in una località non precisata sulla sponda meridionale della foce del tevere, risale al 620 a.c.; l’insediamento aveva lo scopo di controllare le foci del tevere e di contrastare il potere della città etrusca di veio sulla zona delle saline, poste a nord della foce del fiume. se si accetta la datazione dell’attività di estrazione del sale, riportata dalla tradizione romana, concordante con altre informazioni storico-archeologche, si deve ammettere che l’ingressione marina deve essere avvenuta almeno nel vii secolo a.c.: tale datazione non contrasta con i dati geologici e può quindi essere accettata. il secondo sfondamento dei cordoni litorali deve quindi risalire al periodo compreso tra ix-x e vii secolo a.c. il terzo sfondamento (responsabile dello sviluppo della superficie di erosione s.e.3) è successivo al periodo iniziale della sedimentazione dei cordoni litorali della sesta fase (post iv sec a.c.) e penecontemporaneo o di poco precedente ai lavori di costruzione del porto di claudio che iniziarono nel 42 d.c. lo sfondamento dei cordoni litorali può essere dovuta all’arretramento della linea di costa, ma potrebbe anche essere dovuta a tracimazione delle acque delle paludi retrodunari verso il mare e agli interventi antropici. per ora non si hanno elementi oggettivi per scegliere tra le varie ipotesi. tuttavia la penecontemporaneità tra l’ultimo sfondamento dei cordoni, le opere romane nell’area di campo salino, segnalate da morelli et. al. (2004), e la costruzione del porto di claudio, suggerisce che lo sfondamento possa essere stato influenzato dagli interventi antropici. non si può, inoltre, escludere del tutto che lo sfondamento dei cordoni litorali della quinta fase sia stato favorito dagli etruschi almeno a partire dal vii secolo a.c. per impiantare le saline. anche a sud del tevere (presso l’attuale ostia antica) erano presenti saline nel vii secolo: in questa zona non si notano sfondamenti dei cordoni litorali e le saline dovevano quindi essere collegate al mare attraverso un canale artificiale simile o coincidente con quello che è stato utilizzzato fino al xix secolo. appare fondamentale, per l’impatto che ha avuto sull’evoluzione dello stagno di maccarese, lo sfondamento che ha dato luogo alla superficie di erosione s.e.2 (successiva alla data 910-800 a.c. e precedente al vii secolo a.c.): a partire dal quel momento le paludi di acqua dolce che perduravano almeno dal 5380-5280 cal a.c. si trasformarono, salvo brevi interruzioni, in lagune di acqua salmastra, grazie al collegamento col mare. solo nel corso della fase di progradazione moderna del delta, con la sedimentazione di fasce estesissime di cordoni litorali, i collegamenti col mare vennero chiusi e le acque dello stagno tornarono ad essere oligoaline e poterono superare il livello del mare, tanto che il livello dello stagno di maccarese variava stagionalmente, nel periodo appena precedente la bonifica, tra 40 e 80 cm sul livello del mare. 2.2 gli antichi canali di drenaggio di le pagliete e di maccarese l’osservazione dettagliata delle fotografie aeree ha permesso di rilevare che, ben al di fuori dell’area 485evoluzione tardo olocenica ... sulla quale sono intervenuti i lavori dei porti nel periodo imperiale romano, sono presenti i resti di due canali emissari delle paludi di le pagliete e di maccarese, mai segnalati in precedenza. in fotografia aerea sono ancora visibili, infatti, i resti di scavi, stretti ed allungati, di forma regolare (rappresentati in fig. 1 come simboli dpa e dpm) che tagliano i cordoni litorali di varie fasi fino a quelli della parte iniziale della vi fase e sono sigillati da altri cordoni della vi fase. vi sarebbe quindi una coincidenza cronologica tra il periodo nel corso del quale sono stati scavati i canali de le pagliete e di maccarese, il periodo in cui è avvenuto il terzo sfondamento dei cordoni nella zona ad est di focene e la costruzione del porto di claudio. 2.3 gli alvei di rotta fluviale di le vignole un'altra situazione morfologica rilevata dalle fotografie aeree, in località le vignole, poco a valle dell’area ove il fiume entra nella piana deltizia, merita di essere puntualizzata. presso le vignole (fig.2), è stata individuata la presenza di piccoli ventagli di crevassa, distinguibili in base a morfologia e litologia, e di tracce di alvei prodottisi per superamento e rottura degli argini naturali del tevere ad opera delle acque di piena. tali alvei sono indicati da blande depressioni del piano campagna, allungate verso nw, ben individuabili su alcune fotografie aeree perché presentano diverso grado di umidità dei suoli rispetto alle aree circostanti. anche attualmente, in quella zona, l’alveo fluviale scorre tra argini naturali (oltre a quelli artificiali) ed i sedimenti di tali argini sovralluvionano parzialmente gli alvei di rotta fluviale appena descritti. non si posseggono elementi diretti per la datazione delle rotture di argini in zona le vignole, tuttavia essendo l’area superata dall’antica via portuense (costruita per collegare i porti imperiali con roma) sembra probabile che si tratti, prevalentemente, di morfologie precedenti al i secolo d.c. i limi grigi di origine alluvionale presenti a campo salino, contenenti la data di 910 – 800 a.c. sono gli unici interpretabili come sedimenti alluvionali, deposti da acque torbide provenienti dalle rotture di argine del tevere: gli alvei di rotta fluviale sarebbero quindi databili a tale periodo. segre (1986), osservando probabilmente gli stessi indizi morfologici, ipotizzò che presso le vignole l’alveo del tevere deviasse verso nord, per sfociare nella palude di maccarese. nella zona appena ad est dei porti imperiali, i depositi alluvionali del tevere sono tagliati da un canale, ancora parzialmente visibile in fotografia aerea, che fa parte delle opere contemporanee al porto di claudio, del i sec. d.c.: il canale appare però parzialmente riempito da depositi alluvionali successivi: in quest’area si ripete quindi la situazione descritta per le vignole. sarebbero stati i sedimenti alluvionali, databili dal ix-x secolo a.c. in poi, a coprire i cordoni litorali nella fascia compresa tra la zona ad oriente dei porti imperiali e la zona di ostia antica ed a produrre la netta separazione morfologica ancora oggi visibile tra zona a nord e a sud del tevere. 3 discussione in base ai dati riportati nei capitoli precedenti è possibile inquadrare cronologicamente lo sviluppo dei cordoni litorali (fig. 5) e di conseguenza datare l’evolu486 c. giraudi fig. 5 elementi cronologici utilizzati per la datazione dei cordoni litorali. chronological data used for dating beach ridges zione del delta, a partire da 4000 anni cal. a.c., e gli spostamenti della foce del tevere. i cordoni litorali delle prime due fasi possono essere datati (fig. 5) rispettivamente ad un periodo precedente a 4042-3792 e a 3275-2930 anni a.c., mentre quelli della terza fase sono databili al periodo attorno a 3275-2930 anni a.c. i cordoni della quarta fase si sono formati in un momento successivo a 2140-1920 anni a.c. e precedente al 1000-1300 a.c., quelli della quinta in un periodo attorno a 910-800 anni a.c. i cordoni della sesta fase si sono formati a partire da un momento successivo al iv sec a.c. (a partire dal i secolo a.c. interpretando le informazioni di plinio il vecchio) fino ad un momento precedente al 1400 d.c., mentre i cordoni della settima ed ottava fase sono tutti successivi al 1400 d.c. la forma e l’estensione dei cordoni litorali delle varie fasi permettono poi di ricostruire gli spostamenti della foce del tevere. appare chiaro che, almeno in corrispondenza della formazione dei cordoni conservati della seconda e della terza fase (cioè fino a circa 31402900 anni a.c.), la foce del fiume doveva situarsi in un luogo, non precisabile in dettaglio, posto presso i porti imperiali. le cuspidi dei cordoni litorali conservati della quarta e quinta fase (rispettivamente più antichi di 1000-1300 anni a.c. i primi e databili attorno a 910-800 anni a.c., i secondi) indicano con precisione che l’alveo del tevere coincideva con una parte dell’attuale ramo di fiumicino e la foce doveva trovarsi a sw dei porti imperiali. dragone et al., (1967) avevano già ipotizzato che nel x sec. a.c. la foce del tevere fosse nella zona dei porti imperiali. l’interpretazione dei dati geologici e di quelli storici sulla fondazione di ostia testimoniano che, in un momento successivo a 910-800 anni a.c. e precedente al iv secolo a.c., deve essere avvenuto uno spostamento verso sud della foce del tevere. il fiume, probabilmente, sboccò in un primo tempo nell’area paludosa presente alle spalle di ostia antica; il livello dell’acqua nelle paludi dovette aumentare finché si aprì un varco nei cordoni litorali della zona appena ad ovest del sito dove sorse, poi, la città romana di ostia. l’ultimo tratto del tevere assunse quindi una posizione molto vicina a quella attuale. dopo la diversione dell’alveo verso sud, si formarono i cordoni litorali che produssero la prima cuspide nella zona ad ovest di ostia. nel corso della sedimentazione di tali cordoni vennero eseguiti i lavori per la costruzione dei porti imperiali del i e ii secolo d.c. e venne scavato il ramo fluviale artificiale di fiumicino. questo ramo per un certo tratto ricalcò l’alveo fluviale abbandonato a causa della diversione precedente al iv secolo a.c. si può notare altresì, che i cordoni dell’ottava fase (databili dal xvi al xix secolo d.c. e che si sono prodotti a seguito di una lunga fase di piene eccezionali che trasportavano grandi quantità di sedimenti) occupano un’area pari o superiore a quella occupata dai cordoni di tutte le fasi precedenti. tra i cordoni più antichi del xvi secolo d.c., quelli della quarta fase sono i più estesi, seguiti da quelli della terza. i cordoni della sesta fase presentano poi una peculiarità: sono stretti e poco estesi a sud della foce del tevere, mentre si allungano e si ampliano molto verso nord. una situazione simile è tipica anche dei cordoni litorali della settima fase, che sono poco estesi, ma disposti in modo asimmetrico, più allungati verso nord. 3.1 – morfologia dei cordoni litorali e fasi di progradazione e regresso del delta l’andamento dei cordoni litorali delle varie fasi, evidenzia che l’avanzamento del delta non è stato continuo, ma è stato caratterizzato da periodi di progradazione, nel corso dei quali si sedimentavano i cordoni litorali, interrotti da periodi di stasi o regressione del margine del delta o di parte del margine. periodi di regressione del delta sono poi indicati dai cordoni litorali che tagliano quelli più antichi: è il caso dei cordoni della seconda fase che tagliano quelli della prima, dei cordoni della sesta fase che tagliano quelli della quinta e dei cordoni della settima fase che tagliano quelli della sesta. la limitata estensione verso sud dei cordoni della sesta e settima fase può essere stata determinata da erosioni successive: l’azione erosiva può essere però negata se si assume che, per quel periodo, le correnti litoranee dirette in prevalenza verso nord abbiano avuto un ruolo nettamente più importante nel trasporto costiero dei sedimenti rispetto ai periodi precedenti e successivi. anche gli sfondamenti dei cordoni litorali posteriori alla terza ed alla quinta fase, e quelli compresi nell’ambito della sesta fase potrebbero implicare una regressione della linea di costa. i dati storici indicano poi un arretramento della linea di riva nel iii secolo d.c., che avrebbe interrotto per un certo periodo la sedimentazione dei cordoni della sesta fase. procopio di cesarea (vi sec d.c.) descrive l’area del delta e riporta le distanze tra la biforcazione del tevere e il mare e fra i due rami del tevere: se i dati fossero attendibili si avrebbe la prova che nel vi secolo d.c. la linea di costa era più avanzata di quella precedente il xv secolo d.c. ed una ulteriore conferma dell’arretramento della linea di costa nel periodo successivo alla formazione dei cordoni litorali della sesta fase. nel complesso, la più chiara fase di regressione del delta, particolarmente evidente nella zona dei porti imperiali e di ostia, è quella verificatasi nel periodo post-romano, prima della sedimentazione dei cordoni della settima fase. in alcuni dipinti del xvi secolo (all’inizio della forte fase di progradazione del delta) sono rappresentati, nella zona ad ovest dei porti imperiali, ruderi immersi nel mare. questi ruderi non sono necessariamente attribuibili a resti di opere portuali costruite in acqua, ma potrebbero semplicemente essere manufatti costruiti sulla terraferma, trovatisi poi in acqua a seguito della forte regressione del delta avvenuto in epoca postromana. nel periodo precedente al ii secolo a.c. potrebbero essersi verificati arretramenti della linea di costa ancora più notevoli, legati all’aumento di livello del mare. secondo antonioli & leoni (1998), che hanno costruito una curva della risalita olocenica di livello del mare basata sullo studio di insediamenti archeologici costieri, tra i quali molti relativi al lazio, il livello marino doveva essere: circa 6 m sotto il livello attuale attorno a 5000 anni fa; 487evoluzione tardo olocenica ... circa 4 m sotto il livello attuale attorno a 4000 anni fa; circa 2,5 m sotto il livello attuale circa 3000 anni fa; circa 1,7 m sotto il livello attuale attorno a 2400 anni fa; pochi decimetri sotto il livello attuale attorno a 2000 anni fa. anche secondo i dati di bellotti et al (1995) sul delta del tevere, il livello del mare attorno a 5000 anni radiocarbonio b.p. era ancora basso, circa 5 m al di sotto di quello attuale, ed in seguito risalì gradualmente. quindi, contemporaneamente allo sviluppo dei cordoni litorali dalla prima fino alla sesta fase, è avvenuto un aumento di livello del mare ancora sensibile. l’ingressione marina contrasta l’avanzamento del delta e tende a produrre l’arretramento della linea di costa. l’aumento di livello del mare può avere causato la sedimentazione di depositi marini sui cordoni litorali, come dimostrato da bellotti et al. (1994,1995) per il tardo pleistocene superiore e la prima metà dell’olocene, e l’erosione di parte dei cordoni litorali precedenti l’ingressione marina. in base alle quote del l ivello marino, è lecito ipotizzare che i cordoni litorali più antichi (conservati attualmente a quote superiori al livello del mare) si spingessero verso mare fino a quote inferiori di circa 4-5 m rispetto al livello marino attuale, e che occupassero un’area di gran lunga più estesa rispetto a quella attuale: gran parte dell’areale da loro occupato deve essere stato coperto da cordoni litorali successivi o eroso dal mare in risalita. tutti i gruppi di cordoni litorali del periodo precedente al 1500 d.c. debbono essere stati più estesi di quanto risulta attualmente in base ai dati di superficie e debbono essere stati parzialmente coperti e/o erosi. un’idea dell’arretramento dei cordoni della quinta e sesta fase può essere dedotta dalla fig. 2. un lembo isolato di cordoni della quinta fase è presente al margine nord del porto di claudio, in corrispondenza della terminazione orientale del molo. l’estremità occidentale di tale lembo indica che la linea di costa nel corso della quinta fase doveva trovarsi almeno 400 m più ad ovest del margine dei cordoni della stessa fase attualmente osservabili più a nord. anche per i cordoni della sesta fase può essere valutata l’estensione 488 c. giraudi fig. 6 – posizione della linea di costa in vari periodi della seconda metà dell’olocene. sul grafico sono segnate le posizioni della linea di costa prima dello sviluppo dei cordoni litorali delle varie fasi: infatti, poiché i cordoni più esterni di ogni singola fase sono stati erosi o coperti, non è possibile ricostruire l’effettivo andamento della linea di costa alla fine di ogni singola fase di avanzamento del delta. position of coastline in various periods in the latter half of the holocene. the positions of the coastline before the development of the beach ridges in the various phases are marked on the graph. in fact, as the outermost ridges in each phase were eroded or covered, it is not possible to recognize the coastline at the end of each single phase of delta advance. verso ovest. come visibile in fotografia aerea, e rappresentato in fig. 2, la fossa traiana, l’alveo artificiale scavato dai romani, nell’ultimo tratto ha un andamento diverso dal ramo fluviale di fiumicino ed appare colmata da sedimenti fluviali e sbarrata da cordoni litorali. nell’opera originaria non era presente la curva del fiume verso wnw ma l’alveo continuava per alcune centinaia di metri, seguendo la direzione del tratto adiacente della fossa traiana. si può ragionevolmente ritenere che la linea di costa del ii secolo d.c. si situasse presso il tratto finale della traccia, vale a dire circa 300-400 m più ad ovest dei cordoni più esterni della sesta fase attualmente conservati. l’arretramento della costa successiva al ii secolo d.c. in questa zona del delta sarebbe stato di diverse centinaia di metri. la sproporzione tra l’area occupata dai cordoni litorali della ottava fase e quelli delle fasi più antiche, evidenziata da tutti gli autori precedenti, potrebbe essere solo apparente: i cordoni dell’ottava fase sono ancora quasi completamente conservati mentre quelli più antichi sono stati coperti da sedimenti più recenti o erosi, ma potrebbero essere stati molto estesi ed essere ancora presenti nel sottosuolo. la fortissima avanzata posteriore al xvi secolo d.c. potrebbe, perciò, non essere molto diversa da alcune di quelle verificatesi in precedenza: per spiegare l’avanzamento del delta negli ultimi secoli potrebbe non essere necessario invocare eccezionali eventi naturali ed interventi umani straordinari. 3.2 correlazione tra fasi di progradazione ed arretramento del delta e variazioni climatico-ambientali le fasi di avanzata e di regressione del delta del tevere nella seconda metà dell’olocene debbono essere state provocate, oltre che dall’influenza delle oscillazioni glacio-eustatiche di livello del mare, anche da variazioni ambientali avvenute nel bacino di alimentazione del fiume. le variazioni ambientali, specialmente quelle di epoca romana e moderna, possono anche essere dovute ad interventi antropici sull’alveo o sul suo bacino. già bellotti et al. (1994) avevano ipotizzato una correlazione tra l’avanzata del delta avvenuta a partire dal xv secolo ed il periodo climatico conosciuto come piccola età glaciale. tali autori avevano anche stabilito una correlazione più generale tra i periodi di avanzamento del delta e le fasi climatiche caratterizzate da forti alluvioni nel corso del periodo romano e postromano. giraudi (in stampa) studiando e datando la serie dei sedimenti alluvionali presenti a campo imperatore ed in altre località di alta montagna dell’appennino, ha constatato che, per gli ultimi 2200 anni, vi è una chiara correlazione tra fasi alluvionali registrate dai sedimenti in montagna, periodi di maggior frequenza delle alluvioni del tevere riportati in camuffo & enzi (1994), fasi di avanzata del delta tiberino, periodi di alto livello dell’acqua dei laghi trasimeno e fucino e fasi di avanzata del ghiacciaio del calderone, sul gran sasso d’italia. in particolare questa corrispondenza si verifica dal ii sec. a.c. alle fasi iniziali del i sec. d.c. (quando si formavano i cordoni litorali della parte iniziale della sesta fase), dal vi al ix sec d.c. (quando, verosimilmente, si formavano i cordoni litorali della parte medio-finale della sesta fase), e dal xv al xix secolo d.c. (quando si formavano i cordoni litorali della settima e ottava fase). si verifica inoltre una corrispondenza tra fasi di sviluppo dei suoli in montagna e periodi caratterizzati da scarsa attività alluvionale del tevere, quindi nei secoli iii-v d.c. e x-xiii d.c. in questi stessi periodi si verificarono due arretramenti del delta: quello che ha interrotto per un certo periodo la sedimentazione dei cordoni litorali della sesta fase e quello precedente la sedimentazione dei cordoni della settima fase. le variazioni ambientali avvenute sull’appennino, quindi, debbono avere influenzato il regime idraulico del tevere e la quantità di sedimenti trasportati al delta. in particolare durante i periodi più freddi e umidi, si verificavano più alluvioni ed un maggiore trasporto solido, mentre durante quelli più caldi diminuivano le alluvioni ed il trasporto solido a causa dell’espansione della vegetazione in montagna. in base ai dati esposti ed assumendo che almeno le variazioni del ghiacciaio del calderone non possano essere state influenzate dagli interventi umani, è possibile dedurre che le fasi di progradazione e di ritiro del delta sono state controllate, principalmente, dalle variazioni climatiche, anche se è probabile un certo grado di influenza degli interventi antropici sul tevere e sul delta. se si assume che le fasi di progradazione del delta siano collegate a periodi di clima freddo e umido, è lecito estendere indietro nel tempo la correlazione tra avanzamenti del delta ed eventi climatici registrati in appennino. in base ai lavori di giraudi (2002b, 2003a, 2004) sulle variazioni del ghiacciaio del calderone, giraudi (2003b) sui depositi alluvionali del gran sasso e giraudi (1998) sulle variazioni di livello del fucino, è possibile stabilire che nelle zone montane dell’appennino si sono verificati, negli ultimi 6000 anni circa, alcuni periodi freddi e umidi indicati da: 1un’espansione del ghiacciaio del calderone databile attorno a 905-775 a.c. ed un aumento di livello del fucino databile attorno al 900-800 a.c.; 2un’espansione del ghiacciaio del calderone databile ad un momento successivo a 2570-2140 anni a.c. ed un aumento di livello del fucino databile attorno al 2880-2460 a.c.; 3un aumento di livello del fucino datato 3000-3300 a.c.; 4un aumento di livello del fucino datato 4250-3770 a.c. gli eventi segnalati al punto 1 (databili attorno al 905-775 a.c. ed al 900-800 a.c.), sono coevi con la fase di alluvionamento e di avanzamento del delta che produsse i cordoni della quinta fase databile attorno a 910-800 a.c. gli eventi segnalati al punto 2 (successivi a 25702140 a.c.) potrebbero essere coevi con la fase di sedimentazione dei cordoni litorali della quarta fase, di età compresa tra 2140 e 1920 anni a.c. e 1000-1300 anni a.c. l’evento segnalato al punto 3 (datato 3000-3300 a.c.) è coevo con la formazione dei cordoni litorali della terza fase, datati attorno a 3275-2930 a.c. l’evento relativo al punto 4 potrebbe essere coevo alla sedimentazione dei cordoni litorali della seconda o della prima fase, per i quali non esistono però elementi di datazione. almeno per gli eventi dei punti 1 e 3 sembra confermata la correlazione tra le fasi di avanzamento del delta e le fasi fredde e umide. 489evoluzione tardo olocenica ... 4 ipotesi sull’asimmetria del delta precedente alla settima fase di progradazione osservando la porzione settentrionale del delta, è possibile notare che la distribuzione e la morfologia dei cordoni litorali delle varie fasi mostrano, come evidenziato in precedenza, alcune situazioni peculiari ed un andamento asimmetrico. i cordoni della prima fase si estendono verso nord a partire da circa 5,5 km di distanza dal tevere, quelli della seconda fase a partire da circa 2,5-3 km dal fiume, quelli della terza fase a partire da circa 1,5 km. i cordoni litorali si originano nei pressi della foce dei fiumi e, quando questo non si verifica, possiamo assumere che nell’area compresa tra i tratti conservati e la foce del fiume essi siano stati coperti da sedimenti più recenti e/o erosi. nella zona a nord dei porti imperiali, i cordoni litorali più antichi (prima, seconda e terza fase), ad andamento rettilineo, sono disassati rispetto a quelli presenti a sud ed appaiono più arretrati verso est rispetto a questi. i rami settentrionali delle cuspidi dei cordoni litorali della iv e v fase non presentano continuità con i cordoni coevi posti più a nord e sono molto avanzati e collegati ai cordoni della porzione meridionale del tevere. esiste un limite abbastanza netto tra le due aree, che appare stretto ed allungato in senso circa est-ovest. le situazioni descritte potrebbero essere spiegate assumendo che la porzione di area deltizia posta a sud est di focene ed a nord dei porti imperiali sia soggetta a subsidenza differenziale rispetto alla zona meridionale, ma anche a quella settentrionale ove sono conservati i cordoni litorali della prima fase. la subsidenza di quest’area era già stata individuata e calcolata, ma non associata a fenomeni morfologici, da amorosi e milli (2001) che avevano ottenuto valori inferiori a 0,6 mm/anno. come conseguenza della subsidenza in area costiera si verifica una diminuzione di quota della superficie che favorisce l’ingressione marina e l’arretramento della linea di costa. tale ingressione potrebbe essere in grado di contrastare o ritardare la progradazione del delta. l’arretramento della linea di costa, denunciata dai vari cordoni litorali precedenti a quelli della settima fase, inizia bruscamente a nord di una fascia assai stretta che limita a nord la zona dei porti imperiali. la morfologia dei cordoni litorali sembra escludere che la causa vada attribuita ad un minor trasporto solido operato dalle correnti litoranee, anzi mostra chiaramente una prevalenza del trasporto verso nord: il minor grado di avanzamento del delta a nord dei porti imperiali deve quindi essere stato provocato dalla subsidenza differenziale tra aree contigue, limitate da un elemento assai netto non osservabile in superficie. se si osserva la fig.3 di bellotti et al. (1995) nella quale sono riportati gli spessori dei sedimenti della sequenza deposizionale post glaciale del delta del tevere (l’andamento semplificato delle isopache è riportato in fig. 2 nel presente lavoro) si può notare che, nel sottosuolo dell’area compresa tra i porti imperiali e focene, lo spessore dei sedimenti post-glaciali è maggiore che nel resto dell’area deltizia. secondo bellotti et al. (1995), in tale zona era presente la valle fluviale scavata dal tevere nel corso del periodo di basso livello del mare contemporaneo all’ultimo massimo glaciale. nel sottosuolo del margine settentrionale dei porti imperiali esiste quello che era il ripido versante sinistro idrografico di quella valle: la potenza dei sedimenti della sequenza deposizionale deltizia aumenta quindi decisamente in questa zona. si può perciò ipotizzare che vi sia stata subsidenza dovuta a costipazione dei sedimenti deltizi e che questa sia stata maggiore nella zona dove i depositi sono più potenti. la subsidenza differenziale potrebbe spiegare tutte le situazioni relative alla forma, alla discontinuità ed al minor grado di conservazione, in superficie, dei cordoni litorali più antichi. la subsidenza potrebbe quindi spiegare anche la presenza di un piccolo golfo nella zona di interruzione dei cordoni litorali, golfo che i romani sfruttarono e inglobarono, almeno parzialmente, nel bacino del porto di claudio. 5 i canali di le pagliete e maccarese e lo sfondamento dei cordoni della sesta fase ad est di focene come evidenziato in uno dei capitoli precedenti, vi è coincidenza tra il periodo nel corso del quale sono stati scavati i canali di drenaggio antichi de le pagliete e di maccarese ed il periodo in cui è avvenuto il terzo sfondamento dei cordoni nella zona ad est di focene: si tratta di un periodo penecontemporaneo o di poco precedente la costruzione del porto di claudio (i sec. d.c.). tuttavia, se lo sfondamento dei cordoni litorali nella zona di focene fosse stato naturale, non sarebbe stato necessario scavare un altro canale nella zona di maccarese, in quanto si trattava di un’unica laguna. la spiegazione più logica è che i lavori del canale presente nella zona di maccarese facessero parte di un intervento di gestione complessiva della laguna del settore nord del delta tiberino, lavori che comprendono anche le opere segnalate da morelli et al. (2004) a campo salino: è possibile che tra l’area di maccarese e di campo salino vi fosse una barriera artificiale. nell’ottica di una gestione complessiva delle paludi, appare ragionevole attribuire lo sfondamento dei cordoni litorali coevi allo scavo dei canali di maccarese e le pagliete a interventi artificiali eseguiti al fine di collegare meglio le paludi col mare. 6. conclusioni gli studi morfologici e stratigrafici effettuati hanno permesso di riconoscere e di datare l’evoluzione del delta del tevere con maggior dettaglio ed i principali risultati raggiunti vengono sintetizzati di seguito. l’esame morfologico ha permesso di stabilire che vi sono gruppi di cordoni litorali che costituiscono otto insiemi omogenei che possono essere seguiti sia nella zona settentrionale che meridionale del delta. i gruppi di cordoni litorali affioranti al piano campagna indicano otto fasi di avanzamento del delta: la prima fase è più 490 c. giraudi antica di circa 3700-4000 anni a.c.; la seconda più antica di 3275-2930 anni a.c.; la terza ha età prossima a 3275-2930 anni a.c.; la quarta ha età compresa tra 2140-1920 anni a.c. e 1300-1000 anni a.c.; la quinta ha età prossima a 910-800 anni a.c.; la sesta ha un’età compresa tra il iv secolo a.c. (i secolo a.c. secondo gli autori latini) ed il x secolo d.c.; la settima e l’ottava fase sono databili al periodo compreso tra il xv ed il xix secolo. e’ stato possibile stabilire che fino, almeno, al ix secolo a.c. la foce del tevere era situata in corrispondenza dell’attuale alveo di fiumicino: solo tra viii e iv secolo a.c. il fiume subì una diversione verso l’attuale foce. il delta ha subito anche varie fasi di arretramento, avvenute tra la sedimentazione dei cordoni litorali della prima e della seconda fase (età maggiore di 3275-2930 anni a.c., tra quinta e sesta fase (età compresa tra viii e i secolo a.c.), nel corso della sesta fase (iii secolo d.c.), e, quello morfologicamente più evidente, successivo ai cordoni della sesta fase, databile al medioevo (x-xiii sec). sensibili arretramenti della linea di costa, devono essere avvenuti anche tra 6000 e 2000 anni fa a causa della risalita eustatica del livello del mare e porzioni, anche estese, dei gruppi di cordoni litorali debbono quindi essere state erose o giacere coperte da sedimenti più recenti. i cordoni litorali formati nel corso della forte avanzata del delta che avvenne a partire dal xv secolo occupano attualmente un’estensione maggiore di quella dell’insieme dei cordoni di età più antica. questo fatto non implica che il loro sviluppo areale sia eccezionale: i cordoni litorali più recenti potrebbero essere più estesi solo perché conservati nella loro interezza. e’ stato rilevato che nell’area ad est di focene i cordoni litorali hanno subito vari sfondamenti nel corso del tempo: il primo dopo 3275-2930 anni a.c., il secondo in un periodo successivo a 910-800 anni a.c. e precedente al vii secolo a.c., il terzo nel corso, probabilmente, del i secolo d.c. in particolare, il secondo sfondamento ha permesso l’ingressione di acqua salata nelle paludi di acqua dolce dello stagno di maccarese che esistevano almeno dal 5300-5200 a.c. l’ultimo di questi sfondamenti sembra dovuto a interventi antropici, forse collegati alla costruzione del porto di claudio. nell’area di maccarese e di le pagliete sono stati individuati i resti di due canali artificiali di età romana che suggeriscono, insieme a manufatti presenti a campo salino, un tentativo di gestione complessiva delle paludi presenti nell’area settentrionale del delta. dal confronto tra l’evoluzione del delta, la frequenza degli eventi alluvionali del tevere a roma, le fasi climatiche registrate in appennino è emerso chiaramente che le fasi di progradazione del delta sono coeve con fasi climatiche più fredde e umide, mentre le fasi di arretramento della costa sono correlabili a periodi più caldi. l’evoluzione del delta, seppure condizionato da interventi antropici, appare essenzialmente collegata all’evoluzione climatico-ambientale dell’appennino. infine si può ipotizzare che l’asimmetrico sviluppo dei cordoni litorali a nord e a sud dell’area dei porti imperiali sia dovuto ad un diverso grado di subsidenza. anche se limitata, nel corso del tempo la subsidenza avrebbe influenzato l’evoluzione della linea di costa, favorendo la formazione di una discontinuità dei cordoni litorali nell’area a nord del ramo di fiumicino e la formazione di un piccolo golfo, nelle adiacenze del quale vennero scavati i bacini e costruite le infrastrutture del porto di claudio. ringraziamenti si ringrazia g. belluomini che ha fornito la calibrazione delle date radiocarbonio presentate nel lavoro belluomini et al. 1986. si ringraziano inoltre d. esu e c. tata per la determinazione delle malacofaune. a c. morelli e m. bedello, delle soprintendenze di ostia e dell’alto medioevo, a. manfredini, c. conati, g. carboni dell’università “la sapienza” di roma, va un particolare riconoscimento per avere favorito gli studi geologici sui siti le cerquete e campo salino. un grazie anche ad a. facciolo, m. gala, m.c. grossi, m.l. rinaldi, d. ruggeri, s. sivilli, a. tilia, per l’aiuto fornito nel corso dello studio delle trincee di campo salino. riferimenti bibliografici amenduni g. (1884) sulle opere di bonificazione della plaga litoranea dell’agro romano che comprende le paludi e gli stagni di ostia, porto, maccarese e delle terre vallive di stracciacappa, baccano, pantano e lago dei tartari. relazione del progetto generale 15/7/1880. min.ll.pp. ed. eredi botta, 1-36. amorosi a., milli s. (2001) late quaternary depositional architecture of po and tevere river deltas (italy) and worldwide comparison with coeval deltaic successions. sedimentary geology, 144, 357375. antonioli f., leoni g. (1998) siti archeologici sommersi e loro utilizzazione quali indicatori per lo studio delle variazioni recenti del livello del mare. il quaternario,11(1), 53-66. bellotti p., chiocci f.l., evangelista s., tortora p. & valeri p. (1987) la superficie di discordanza alla base del delta del tevere e le sue relazioni con la geometria del corpo deltizio. memorie della società geologica italiana, 37, 407-415. bellotti p., carboni m.g., milli s., tortora p., valeri p. (1989) la piana deltizia del fiume tevere: analisi di facies e ipotesi evolutiva dall'ultimo low stand glaciale all'attuale. giornale di geologia, ser. 3a, 51/1, 71-91. bellotti p., chiocci f.l., milli s., tortora p. & valeri p. (1994) sequence stratigraphy and depositional setting of the tiber delta. integration of high-resolution seismics, well logs, and archeological data. journal of sedimentary research, b64, 3, 416432. bellotti p., milli s., tortora p. & valeri p. (1995) physical stratigraphy and sedimentology of the late pleistocene-holocene tiber delta depositional sequence. sedimentology, 42,617-634. belluomini g., iuzzolini p., manfra l., mortari f., zalaffi m. (1986) evoluzione recente del delta del tevere. geol. rom., 25, 213-324. bocci d. (1892) il delta tiberino. giornale del genio civile, 30, 1-34. 491evoluzione tardo olocenica ... camuffo d., enzi s. (1994) cambiamenti climatici negli ultimi 2000 anni. il quaternario, 7(1), 257-266. carboni g., conati barbaro c., manfredini a. (2002) datazioni radiometriche e correlazioni con l’eneolitico dell’italia centrale. in: le dune, il lago, il mare. una comunità di villaggio dell’età del rame a maccarese. a. manfredini ed. 255-260. istituto italiano di preistoria e protostoria, firenze chiocci f.l., milli s. (1995) construction of a chronostratigraphic diagram for a high-frequency sequence: the 20 ky b.p. to present tiber depositional sequence. il quaternario, 8(2), 339-348. conti a.m. (1982) studio preliminare su materiali dell’età del ferro da ostia antica. in: iv convegno dei gruppi archeologici del lazio . gruppi archeologici d’italia, roma. dragone f., maino a., malatesta a. & segre a.g. (1967) note illustrative del foglio 149 cerveteri della carta geologica d’italia. servizio geologico, 4, 1-93. giraudi c. (1998) late pleistocene and holocene lake level variations in fucino lake (abruzzo central italy) inferred from geological, archaeological and historical data. esf workshop "palaeohydrology as reflected in lake-level changes as climatic evidence for holocene times". palaoklimaforschung, 25, 1-17. gustav fisher verlag ed. giraudi c. (2002a) evoluzione ambientale tardo-olocenica dell’area comprendente il sito eneolitico di maccarese (fiumicino). in: le dune, il lago, il mare. una comunità di villaggio dell’età del rame a maccarese. a. manfredini ed. 25-35. istituto italiano di preistoria e protostoria, firenze. giraudi c. (2002b) le oscillazioni del ghiacciaio del calderone (gran sasso d’italia, abruzzo italia centrale) e le variazioni climatiche degli ultimi 3000 anni. il quaternario, 15(2), 145-150. giraudi c. (2003a) middle pleistocene to holocene apennine glaciations (italy). il quaternario, 16, 3748. giraudi c. (2003b) i depositi alluvionali olocenici di campo imperatore (massiccio del gran sasso abruzzo). il quaternario, 16(1), 117-125. giraudi c. (2004) the apennine glaciations in italy. in: ehlers,j., gibbard, p.l. (eds.), quaternary glaciations-extent and chronology, part. i: europe. 215-224. amsterdam. elsevier. giraudi c. (in stampa) late holocene alluvial events in the central apennines (italy). the holocene. morelli c., facciolo a., gala m., grossi m.c., rinaldi m.l., ruggeri d., sivilli s., tilia a. (2004) acqua e terra: le attività umane sul limite della laguna di maccarese. poster al meeting : computer applications and quantitative methods in archaeology. beyond the artefacts digital interpretation of the past. prato, 13-17 aprile 2004. oberholtzer f. (1875) le foci del tevere. paravia. segre a.g. (1986) considerazioni sul tevere e sull’aniene nel quaternario. in: il tevere e le altre vie d’acqua del lazio antico.quaderni del centro di studio per l’archeologia etrusco-italica, 12, 9 17. testaguzza o. (1970) portus illustrazione dei porti di claudio e traiano e della città di porto a fiumicino julia editrice, roma. 492 c. giraudi ms. ricevuto il 27 ottobre 2004 testo definitivo ricevuto il 20 gennaio 2005 ms. received: october 27, 2004 final text received: january 25, 2005 amq32(1) 43-56 alberdi prado.pub revisiting the evolutionary history and paleobiogeography of fossil horses from south america maría teresa alberdi 1, josé luis prado 2 1 departamento de paleobiología, museo nacional de ciencias naturales (csic), madrid, spain. 2 incuapa, conicet-unicen. universidad nacional del centro de la provincia de buenos aires, olavarria, argentina. corresponding author: m.t. alberdi <malberdi@mncn.csic.es> abstract: horses are a conspicuous group of immigrant mammals from north america that arrived in south america during the late pliocene and no survived the megafaunal extinction, approximately ten thousand years ago. two main equids lineages are found in south america. the first lineage is the species assigned to equus, which appears during the middle pleistocene and shows horse-like anatomical features. the second lineage is the genus hippidion, which were horses with very distinctive anatomical features are recorded for the first time during the late pliocene. the predominance of the dispersal events over vicariant ones is consistent with the migratory habits of horses. the global biogeographic distributions of horses explain the mode of dispersal and their migration from north america to another continent. the dispersal and the diversification process in small to middle size species (equus andium, equus insulatus, hippidion devillei, and hippidion saldiasi) occurred through the andes corridor; whereas the large species (equus neogeus and hippidion principale) mainly traveled using the eastern plain route. the pathway of dispersion in each species reflects its adaptive change and habitat preference. the present study aims to provide a synthesis of already published data on the phylogeny, systematics, palaeobiogeography and palaeoecology of both the lineages recorded in south america, updating some taxonomic data. keywords: equidae, macroevolution, south america, quaternary. available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 32 (1), 2019, 43 56 1. introduction the fossil record of horses is one of the best known and provides an exceptional example of largescale morphological change (simpson, 1951). the radiation of equids during the neogene in north america has been cited as a textbook example of adaptive radiation for more than a century (marsh, 1874), as it is crucial in the development of evolutionary theory, linking trait evolution and adaptive success (simpson, 1953; macfadden, 1992; cantalapiedra et al., 2017). in this study, we present an update on the information of fossil horses in south america, providing a synthesis of already published data on the evolutionary history, phylogeny, systematics, palaeobiogeography, and palaeoecology of two key equid lineages (hippidion and equus) recorded in south america. in his first voyage to south america (1832), darwin made a series of observations on the extinct fauna that were key in many of his later conclusions. during october 1833, darwin found a horse tooth in the red argillaceous earth in the pampas, at “bajada de santa fé”, in the province of entre rios, argentina. later, the paleontologist richard owen (1840: 109) confirmed the tooth was from an extinct species and remarked "this evidence of the former existence of a genus, which, as regards south america, had become extinct, and has a second time been introduced into that continent". since this publication, notes and articles proliferated which in most cases do not reflect the general diversity of this group. recent papers on the equidae from south america recognize two genera: equus and hippidion (prado & alberdi, 2008, 2012, 2016, 2017). the dental morphology of hippidion (oval protocone, rounded protoconid, and hypoconid, reduced metaconid-metastylid double knot) is more primitive than equus, and its body structure is more robust (prado, 1984; alberdi, 1987; alberdi et al., 1986, 1987; cerdeño et al., 2008; prado & alberdi, 1994, 2014, 2016; among others). the genus equus originated in north america during the pliocene and subsequent dispersal to eurasia, africa and south america (macfadden, 1992). in 1950, the french paleontologist robert hoffstetter created the subgenus amerhippus to include all species of genus equus from south america. the author justifies this subgenus by a single character: the absence of infundibulum along the surface of the lower incisors and, therefore, the loss of enamel on the chewing surface. in a https://doi.org/10.26382/amq.2019.04 44 alberdi m.t. & prado j.l. 45 fossil horses from south america later work on the revision of mammals of ecuador hoffstetter (1952) indicated that the ulna is stronger in the south american horses than other equus. in the literature, the recognition of the subgenus amerhippus is controversial. recently prado & alberdi (2017) questioned the use of subgenus amerhippus. orlando et al. (2008) conducted dna-based phylogenetic analyses revealing that all pleistocene south american species of equus were members of the caballine horse lineage, not a distinct subgenus as first suggested by hoffstetter (1950). therefore, the validity of the subgenus amerhippus is questionable, and is not employed herein. the dispersal of the horse equus into south america represents an important event (macfadden, 2013). there is some controversy about the timing of this dispersion. several studies have asserted that the age of this dispersal event is late pleistocene, 0.125 ma (lujanian south american land mammals age, salma), during a late phase of the great american biotic interchange, gabi 4 (cione & tonni, 1999; coltorti et al., 2010; woodburne, 2010). however, tonni et al. (2009) point out that in comparison with the pampean standard, the tarija fauna is not exclusively ensenadan or lujanian salma, given that, although the bulk of the fauna is comparable to that of the pampean lujanian, there are some exclusive taxa of the pampean ensenadan. new biostratigraphic evidence documents that equus occurs from 15 superposed faunal horizons or zones throughout the tolomosa formation at tarija, bolivia. this biostratigraphic sequence is independently calibrated to occur between 1.07 to <0.76 ma (ensenadan salma) and coincident with gabi 3 (macfadden, 2013). many articles have been published of the equus species in south america (fig. 1). prado & alberdi (2017) reviewed this group and recognized three valid species: equus andium branco 1883, ex wagner (1860), equus insulatus ameghino, 1904, and equus neogeus lund, 1840 (fig.s 2 and 3). recently, machado et al. (2017) proposed reducing the number of equus species in south america to one, equus neogeus. we do not share this proposal. this proposal may be due, in our opinion, to the fact that species from north and south america are mixed in the analysis, possibly by the alleged affinity of equus occidentalis with south american forms. the infundibulum in its lower incisors is shared by south american species, for which hoffstetter (1950, 1952) proposes the new subgenus amerhippus, in which he also included the rancho la brea equid, equus occidentalis. the latter species, however, diverges from the other south american species in various characteristics. beside the cornets in the lower incisors, south american equids, according to hofstetter, are characterized by a ventral rotation of the occiput, with a strong deflection of the braincase relative to the face, a broad supraoccipital crest, the vomer joining the palatal processes of the maxillaries well in front of the palatines, and a massive jaw and short limbs. it is true that not all elements of the appendicular skeleton of south american horses are equally diagnostic. for example, when the first phalanges of the third finger are mixed (anterior and posterior), the limits overlap. in the case of metapodes, the metacarpal is more diagnostic than the metatarsals. this is partly because the former limbs are where the weight of the body and the head are most affected (eisenmann, 1984). limb morphometric studies have been useful for discriminating hipparion and monodactyl horse species (eisenmann, 1979). this approach offers a comprehensive view of the material studied. however, in some cases, there are some overlaps, as in the case of the morphometric data between the metapodes of horses, hemiones, asses and equus hydruntinus (eisenmann & beckouche, 1986). the latter do not alter the correlation between all the variables analyzed. in our opinion, it is a mistake to interpret these partial overlaps as continuity. the distal limb of horses is closely related to the adaptation to different environments, type of substrates, body weight, and locomotion. the adaptive nature of metapodials and phalanges variation can be explained by the differential success of lineages in macroevolution. lineages with more advantageous patterns of regulated variation are likely to produce more species (sharov, 2014). this is in relation to the epigenetic mechanisms that provide organisms with opportunities for rapid adaptive change (gokhman et al., 2016). the epigenome is viewed today as a collection of regulatory layers that control when, where, and how genes <<<<< fig. 1 geographic distribution of different taxa of hippidion and equus from south america. in argentina: 1-35, arrecife; 2-34, mercedes (luján); 3-25, arenero spósito y venta obligado (san pedro); 4, ayacucho; 5, necochea; 6, arroyo seco; 7-39, montehermoso; 8, río quequén salado; 9, paso otero 5; 10-33, arroyo ramallo; 11, arroyo tapalqué; 12, calera avellaneda; 13, anchorena; 14-38, barrancas de san lorenzo y alvear (santa fé province); 15, los toldos; 16, las buitreras; 17, cerro bombero; 18, piedra museo; 19, voruheé; 20, mar del sur; 21, lobería; 22, olivos; 23, canal de conjución en puerto la plata; 24, mar del plata; 26, margen izquierda del río quequén grande (buenos aires); 27, barranco negro (jujuy); 28, esquina blanca in uquía; 29, río salado; 30, san luis; 31, carcaraña; 32, uspallata; 36, anchorena; 37, quequén salado; in bolivia: 40-42, tarija; 41-43, ulloma; in brazil: 44, santana (estado de bahia); 45-68, toca dos ossos (estado de bahia); 46-63, grutas de la región de lagoa santa; 47, confins (lapa do galinheiro); 48, lapa come nâo bebe; 49, lapa de bahu and lapa de escribanía (estado de minas gerais); 50, rio paraguai in corumba (estado de mato grosso do sul); 52, curaçaba (estado de bahia); 53, santa vitoria do palmar (rio grande do sul); 54, tanque 2 de itapipoca (estado ceará); 55, curimatãs (estado de paraíba); 56, lage grande (alagoinha); 57, pesqueira (estado de pernambuco); 58, lapa do cavalo; 59, lapa de escribanía 5 and 11; 60, lapa da lagoa do sumidouro; 61, lagoa santa flere hule lapa dos coses; 62, lapa do galinheiro; 64, sao raimundo nonato; 65, piaui; 66, aguas do araxa; 67, chique-chique; in chile: 69, cueva del milodón (ultima esperanza); 70, cueva lago sofia 1; 71, cueva lago sofia 4; 72, cueva de la ventana; 73, cueva del medio; 74, cueva de los chinges; 75, cueva fell; 76, cerro sota; 77, alero tres arroyos 1; 78, betecsa 1; 79, kamac mayu (atacana desert); 80, chacabuco; 81, santa rosa de chena; 82, tierras blancas; 83-93, taguatagua; 84, cueva pali aike; 85-86, calera, lo aguirre; 87, valle de elqui; 88, los vilos; 89, conchalí; 90, colina; 91, punta rieles; 92, huimpil; in colombia: 94, cerrogordo; 95, tibitó; in ecuador: 96, quebrada otón; 97, riobamba; 98, punín (quebrada chalán, quebrada colorada, quebrada grande, quebrada el colegio, etc); 99, alangasí; 100, la carolina; 101, salinas oil fields (santa elena peninsula); 102, río chiche (andes ecuadorian); in perú: 103, tirapata; in uruguay: 104, formación sopas, artigas department; 105, arapey grande creek; 106, sopas creek in the sopas formation; in venezuela: 107, breal de orocual; 108, inciarte (estado de zulia). modified from prado & alberdi (2017). are turned on and off. the promising new high-coverage genome of horses (schubert et al., 2014; gaunitz et al., 2018; librado et al., 2017) will enable paleoepigenetic reconstruction in the near future. the other group of horses in south america is the hippidiforms. owen (1869) created the genus hippidion based on only one molar from brazil. in 1891, moreno described one complete skull and some postcranial remains from the pleistocene of lobería (argentina), and assigned it to onohippidium munizi. the uncertainty began after the nomination and description of both genera in north america by macfadden & skinner (1979). alberdi & prado (1993, 2004) recognized just one genus, hippidion, which is endemic to south america, and that the materials from north america assigned to both genera were not hippidiforms, but closer to dinohippus (prado & alberdi, 1996; alberdi & prado, 1998). avilla et al. (2015) proposed a new genus (boreohippidion) for the remains described as onohippidium in north america. hippidion is recorded from the pliocene to the late pleistocene mainly in argentina, bolivia, brazil, chile, peru, and uruguay (figure 1). prado & alberdi (2017) recognized three species: hippidion principale (lund), hippidion devillei (gervais), and hippidion saldiasi (roth) (figures 3 and 4). these species differ mainly by their body size. hippidion principale is much larger than others, and the differences between hippidion saldiasi and hippidion devillei are based on the shortening metapodial (fig. 5). hippidion is characterized by a retracted nasal notch, which has been interpreted as an adaptation to the presence of a proboscis and limbs with robust metapodials (figures 4 and 5). the upper teeth present an oval protocone, more or less rounded, with simple enamel plication, and the lower teeth have a deep ectoflexid, penetrating the isthmus, and a rounded paraconid and hypoconid. 2. phylogeny the south america species of equus, genus shows horse-like anatomical features and genetic affinities (orlando et al., 2009). biochronological data sug 46 fig. 2 skull of different equus species. 1: equus neogeus from luján, buenos aires province, argentina; 2: equus insulatus from la carolina, santa elena peninsula, ecuador; 3: equus andium from chalan punín, ecuador. fig. 3 upper and lower cheek teeth length of different equus and hippidion species. 1: p2-m3 left of hippidion saldiasi from betecsa 1, calama (ii región, chile); 2: p2-m3 left of equus neogeus from arroyo tapalqué at level of avellaneda street, olavarría (buenos aires province, argentina); 3: p2-m3 right of hippidion principale from monte hermoso (buenos aires province, argentina); 4: p2-m3 right of equus neogeus from monte hermoso (buenos aires province, argentina). alberdi m.t. & prado j.l. gests most of these occurrences are late pleistocene; with one significant exception from the tarija basin in bolivia were equus insulatus is recorded between 0.99 to 0.76 ma (sensu macfadden, 2013). the hippidion genus was first recorded at around 2.5 ma, and includes two genetically similar generalists (hippidion principale, hippidion saldiasi) and one genetically distinct high-altitude specialist, hippidion devillei (prado & alberdi, 1996; orlando et al., 2009). currently, the diversification of hippidion species remains controversial. prado & alberdi (1996) proposed, on the basis of a cladistic analysis using morphological data, the affinity of hippidion with pliohippus. the latter is recorded between 6 and 14 ma in north america. also, hippidion would have diverged from the lineage that leads to modern equidae before 10 ma. this implies a dispersion prior to the time when hippidion is recorded for the first time in south america. on the contrary, a much later divergence date, with hippidion nesting within modern equids, was indicated by the study of partial ancient mitochondrial dna sequences (weinstock et al., 2005). this analysis proposed that hippidion was phylogenetically close to the caballine horses, with origins considerably more recent than the accepted date of around 10 ma. furthermore, based on analysis of ancient dna, orlando et al. (2009) proposed hippidion devillei clusters outside a paraphyletic assemblage con 47 sisting of hippidion principale and hippidion saldiasi. recently, der sarkissian et al. (2015) obtained new mitochondrial data and suggested that the two morphospecies sequences (hippidion saldiasi and hippidion principale) formed a monophyletic clade, basal to extant and extinct equus lineages. this contrasts with previous genetic analyses, and supports hippidion as a distinct genus. this new data allowed us to estimate the divergence between hippidion and equus at approximately 5.6 to 6.5 ma before hippidion entered south america, following the formation of the panamanian isthmus 3.0 to 3.7 ma. 3. palaeobiogeography the contemporary south american mammalian communities were determined by the emergence of the isthmus of panama, and by the profound climatic oscilfig. 4 skull of different hippidion species. 1: hippidion principale from mar del plata, argentina; 2: hippidion devillei, incomplete, from tarija, bolivia; 3: hippidion saldiasi from calama, chile. fig. 5 metapodials of different hippidion and equus species: 1: mciii of hippidion principale from tarija, bolivia; 2: mciii of hippidion devillei from tarija, bolivia; 3: mciii of hippidion salsiasi from última esperanza, punta arenas, chile; 4: mtiii of equus neogeus from quequén salado-indio rico, buenos aires province, argentina; 5: mtiii of equus insulatus from santa elena peninsula, ecuador; 6: mtiii of equus andium from riobamba, ecuador. fossil horses from south america lations during the late pliocene and pleistocene. the emergence of the isthmus closed communication between the atlantic and pacific oceans and changed both water circulations, facilitating the installation of the arctic polar ice cap. the cool circum-antarctic current was finally established (pascual et al., 1996). the pliocene in south america is characterized by the apogee of the age of the southern plains (ortiz-jaureguizar & cladera, 2006). in northern south america, the pliocene vegetation changed sequentially from tropical lowland to high-elevation vegetation as a result of the developing andes. on the contrary, in southern south america, grasslands and steppes were dominant. the most evident changes between tertiary and quaternary climatic conditions are correlated to the amplitude and frequency of the environment. throughout the pleistocene, the repeated advance and retreat of glaciers produced an evident and coincident expansion and retraction of arid and humid environments. a savannah corridor developed along the eastern border of the andes, offering a corridor that linked the grasslands of argentina and colombia, continuing northward across the panamanian land bridge to north america. conversely, when open areas withdrawal during interglacial periods of warm-wet climates, rainforests enlarge and favored a second corridor to expand across eastern south america (sánchez et al., 2004). the gabi is a complex history of multiple dispersal events between the americas during the pliocene and pleistocene. horses were a conspicuous group of immigrant mammals from north america. their demographic history was punctuated by major cycles of expansions and collapses, probably related to the major glacial and interglacial cycles. these dispersions event coincided with the development of two dispersal pathways (webb, 1991), that ultimately contributed to the distribution of horses (prado & alberdi, 2014). recent biogeography studies based both on phytoand zoogeographic data, show that south america is composed of two regions with different evolutionary histories and showing closest links with other austral areas. this pattern is evident in the recent distributions, and in the fossil record dispersion. compiling numerous sources of information, morrone (2014), confirmed the neotropical and andean regions, separated by the andean cordillera, which in turn divides the continent into two different areas: western and eastern. the dispersal and the diversification process in small to middle size species, equus andium, equus insulatus, hippidion devillei, and hippidion saldiasi, occurred through the andes corridor, whereas the large species, equus neogeus, and hippidion principale used the eastern plain route, firstly (fig. 6). the pathway of dispersion in each species reflects its adaptive change and habitat preference (alberdi & prado, 1992) and may have occurred during two or three immigration events. woodburne (2010) described the principal phases of interchange between the americas as gabi 1 (2.6 to 2.4 ma), gabi 2 (1.8 ma), gabi 3 (1.0 to 0.8 ma) and gabi 4 (0.125 ma). in this context, macfadden (2013) suggest that equus neogeus may have originated independently from a north american sister species within the caballine clade, thus suggesting a second dispersal of equus during gabi 4 at 0.125 ma. the first arrival corresponded to equus insulatus recorded in tarija (bolivia) and dispersal through the andes corridor during gabi 3 (macfadden & azzaroli, 1987; macfadden, 2013). equus neogeus is the largest and most slender morphotype of the south american horses, and occurs in eastern south america, but does not occur outside of lowland argentina, uruguay, and brazil. this species preferred savannas and consequently would have been better adapted to open and arid landscapes (prado & alberdi, 1994). the first record of hippidion came from esquina blanca (jujuy, argentina) were hippidion devillei appears in a sedimentary layer dated around 2.5 ma (prado et al., 1998, 2000; reguero et al., 2007) and corresponds to gabi 1. 4. biochronology the salma are stratigraphic units not formally recognized by any code of nomenclature, but as an organizing device. they have proven to be very useful in developing concepts about mammalian stratigraphy and evolution (savage, 1962; simpson, 1971). pascual et al. (1996) suggest that salma has proved to be useful for intra and intercontinental correlations and subdividing 48 fig. 6 the geographic distribution of the equini tribe from south america and possible migratory routes. small to middle size species through the andes corridor (equus andium, equus insulatus, hippidion devillei, hippidion saldiasi) in orange and the large forms (equus neogeus, hippidion principale) used the eastern plain route in violet. modified from prado & alberdi (2017). alberdi m.t. & prado j.l. stages in the pampean region. in this paper, we follow both of these criterions to establish the chronological position of the horses (figure 7). according to alberdi & prado (2004), hippidion devillei was the first species of the equini recorded in south america. it is found in land-mammal bearing sediments of the uquian salma in northern argentina (prado et al., 1998). hippidion principale was recorded for the first time in sediments of the ensenadan salma in bolivia. hippidion saldiasi was recorded in sediments of the lujanian salma in patagonia, argentina (alberdi cenozoic time. the land mammals ages were first proposed by wood et al. (1941) and characterized by unique mammalian assemblages. pascual et al. (1965, 1966), marshall et al. (1983, 1984) and pascual et al. (1996) among others, used salma for south america. recently, cione & tonni (2005) proposed a new biostratigraphic framework involving the continental sediments and faunas of the pampean region, from the late miocene to the present. these authors recognized 13 biozones for this interval, which represent the biostratigraphic basis for the recognition of stages and sub 49 fig. 7 the chronological framework of mammalian biochronology of south america modified from cione & tonni (1999). fossil horses from south america & prado, 2004). so far as the biochronology is known, most of these occurrences of equus are late pleistocene; with one significant exception of equus insulatus from the tarija basin of bolivia. in argentina, uruguay and brazil, equus occurred during the latest pleistocene, and it defines the base of the lujanian salma (sensu pascual et al., 1996). in the pampean region, cione et al. (2009) proposed the equus neogeus biozone based on the “piso lujanense” from ameghino. nevertheless, if equus is restricted to the pampean species equus neogeus, then the use of this latter taxon still can be used as an index fossil for the lujanian stage within the pampean region. it is clear that the lujanian stage or biozone of equus neogeus defined by cione & tonni (1999, 2005) does not correspond to the lujanian salma of pascual et al. (1965, 1996). recently, we recorded remains assigned to equus neogeus from the campo spósito site (province of buenos aires). this site was referred to the bonarian stage, with a base at ~130 ka and top at 10 ka. the level containing the remains of equus was dated by osl, esr and u-th series between 40 to 200 ky bp (prado et al., 2012; toledo et al., 2014, 2015). these findings implied that the status of equus neogeus as an index fossil of the lujanian stage, or its lower limit, should be revised as this taxon clearly expanded in the pampean region before ~130 ka bp. also, these results reinforce the fact that equus dispersed into south america during gabi 3. argentina has allowed discussions on the correlation of type sections in the pampean area with other regions (e.g. reguero & candela, 2011; tauber, 2005). it is necessary to carry out new studies in areas outside the pampean region to contrast this scheme. 5. palaeoecology the skeleton of the fossils mammals has been the main source of information for interpreting its ecology. several studies in horses from south america document changes in body size, skull magnitudes, dentition morphology and limb structure (alberdi & prado, 1993; alberdi et al., 1995; bernardes et al., 2013; prado & alberdi, 1994, 2014). additionally, the use of stable isotopes in fossil horses has been successfully increased (domingo et al., 2012; dantas et al., 2013; prado et al., 2015; among others), and have contributed to understanding the feeding paleoecology of extinct species (macfadden et al., 2004). carbon is fixed through plant photosynthesis, which has three different pathways: c3 (calvin-benson), c4 (hatch-slack), and cam (crassulacean acid metabolism). the c3 pathway is found mainly in dicotyledonean trees and shrub, and in some temperate grasses. the c4 pathway is typical of monocotyledonean grasses, as well as some trees and shrubs from warm regions (cerling et al., 1997) and the cam pathway is found in succulent plants such as cacti and bromeliads. several factors, such as saline soils, low light intensity, and a lack of nutrients, affect the abundance of c3 and c4 plants in ecosystems. the temperature plays an important role, as localities with temperatures below 25 °c show an increase in c3 plants while c4 plants decrease (ehleringer & cerling, 2002). 50 in mammals, digested carbon becomes incorporated into the tissue of the consumer; this is the case for dental enamel apatite (koch, 2007). herbivores have carbon isotopic values enriched by 14‰ in comparison with plant δ13c values (cerling & harris, 1999). based on classifications proposed by hofmann & stewart (1972) and macfadden & cerling (1996), c4 plant eaters show values from -2‰ to 2‰, c3 plant eaters have values from −19 ‰ to −9‰, and c3/c4 mixed-diet herbivores show values between −9‰ and −2‰. the δ13c values of herbivore teeth record a dramatic increase in consumption of c4 grasses during the late miocene and provide the first evidence for appearances of c4 grass in the past (strömberg, 2004). based on mesowear and microwear analyses, fig. 8 average and standard error of isotopic values from different localities in argentina, bolivia, colombia and ecuador of equus (a) and hippidion (b). a: alangasi, at: arroyo talpaqué, b: buenos aires, cv: cantera vial. buenos aires province, cm: centinela mar, e: última esperanza, lb: la banda, lc: la carolina, lv: la venta, l: luján, m: magdalena, n1: napua-1, n3: napua-3, o: ourolandia, ph: punta hermengo, po: paso otero, p: punín, q: quebrada colorada, rc: río chiche, rq: río quequén, s: salinas oil, t: tarija, z: zajón seco, ma: mina aguilar, o: olivos, p: paraná, b: buenos aires, l: luján, s: río salado, a: arroyo talpaqué, q: rio quequén, e: última esperanza. modified from prado & alberdi (2017). alberdi m.t. & prado j.l. mihlbachler et al. (2011) showed that pleistocene horses from north america are able to mainly eat not only grass but also leaves off trees or shrubs. macfadden et al. (1996) suggested the existence of a latitudinal gradient, meaning that above 35° latitude, c3 plants start to increase while c4 plants decrease. the south american horses in general were c3/c4 mixed feeders and lived in grasslands or prairies. although there were some populations that exclusively fed on c3 and occupied forest habitat and other that fed on c4 plants and living in grassland zones (pérez-crespo et al., 2018). the horse populations from argentina show that they mainly ate c3 plants, which indicated the presence of c3 grassland areas (domingo et al., 2012). on the other hand, horses from colombia, brazil, and perú, located above parallel 35°, were specialized c4 plants feeders. domingo et al. (2012) also indicated the presence of a vegetation elevation gradient, where c4 plants were abundant in lower zones, and c3 plants were abundant in higher zones, explaining the diet of bolivian and ecuadorian populations. the flexibility in their diet and by extension in their occupied biome agrees with the habitat theory (vrba, 1992) according to which generalists and open biome specialists from north america accomplished successful radiation throughout south america (moreno bofarull et al., 2008). hippidion only fed on c3 plants, although some individuals were c3/c4 mixed feeders, but with important ingest of c3 plants (prado et al., 2011; pérez-crespo et al., 2016). this could be explained by the fact that some individuals inhabited higher elevations, where c3 plants are abundant, or lower latitude than 35°s on c3 were predominate grasslands with nearby forests (domingo et al., 2012). samples from early pleistocene show that hippidion principale and hippidion devillei have δ13c values typical of wooded c3 grassland (figure 8a). hippidion devillei and hippidion saldiasi have lower δ18oco3 values than hippidion principale (figure 8b). this is due to high elevation effects in the case of hippidion devillei, and high latitude effects in the case of hippidion saldiasi (52° s). another important indicator of horses’ ecology is the body size. in all continents, the evolutionary history of the horse was strongly influenced by body size, related with environmental conditions and type of substrates (shoemaker & clauser, 2014; saarinen et al., 2016). 51 fig. 9 last-appearance dates for megafauna from the argentine pampas region, using only robust dates from previous papers and the new dates. the horizontal dashed line indicates a consistent archeological signal. the dotted horizontal line indicates the earliest occupation evidence or minimal human activity. the gray boxes indicate the dates obtained from the literature, the red boxes indicate radiocarbon data of south american horses, and the yellow line is the average of these. black boxes indicate the new dates and the green line is the average of these. the gray band denotes the timing of younger dryas cooling in the argentine pampas region (hajdas et al., 2003; krohling & iriondo, 1999) (modified from prado & alberdi, 2017). fossil horses from south america alberdi et al. (1995) present the body mass predictions for south american fossil horse species. both genera present different patterns. within the hippidion group, the middle sized hippidion devillei produced two body mass species: (1) hippidion saldiasi, which has a similar body mass, and (2) hippidion principale, which reaches a greater size. in the equus group, the large-sized equus insulatus gave rise to two different sized groups: (1) equus neogeus, which retain or increase their body mass; and (2) the small equus andium. 6. horse extinction late quaternary megafauna extinctions impoverished mammalian diversity worldwide (koch & barnosky, 2006). about 70% of south american large mammal species (animals with an average body size ≥ 44 kg) went extinct at the end of the pleistocene epoch (prado et al., 2015). the causes of this extinction the role of humans versus climate have been the focus of much controversy (barnosky & lindsey, 2010; prado & alberdi, 2016, 2017; villavicencio et al., 2016). horses have figured centrally in this discussion because it’s a species that dominated late pleistocene faunas in terms of abundance and geographical distribution, but none survived into the holocene. on a global scale, several species of horses were widespread and common during the middle and late pleistocene, with a distribution that covered most of eurasia and northern africa, as well as north and south america. the late pleistocene was a period of extraordinarily intense environmental change. by the end of this period, the last glacial maximum (lgm) marked one of earths most extreme moments of climatic variability (clark et al., 2009). the decreased grassland in eurasia due to of the lgm caused a massive crash in the horse population. however, one formerly wild subspecies (equus ferus przewalskii) had survived, and abundant genetic diversity has been preserved in domesticated forms (orlando et al., 2009; weinstock et al., 2005). the new world stiltlegged horses disappeared around 30 ka bp in north america, before the earliest arrival of humans (weinstock et al., 2005; vilstrup et al., 2013; prado & alberdi, 2017). in south america, hippidion and equus survived no later than 10 ka bp (prado & alberdi, 2016, 2017). the timing of the horse extinctions in each region of south america is poorly known. there are many archeological sites with recorded horses, but the coexistence with humans is difficult to verify. the taxon dates evidence is very rare and are strictly concentrated in two regions, pampas and patagonia (borrero, 1997; alberdi & prado, 2004). the extinction window in pampas ranges from c. 13.9 and 10.1 ka bp for equus neogeus and c. 11.3 to 15 ka bp for hippidion principale (prado et al., 2015; figure 9). the archaeological record from southern patagonia indicates that the timing of horse extinction was restrained by a complex interaction between climate changes that precipitated vegetation change, associated with growing human impacts (villavicencio et al., 2016). the data from pampas and patagonia are robust enough to consider synergy interaction among last appearance records of horses, first appearance records of humans, and the holocene climatic transitions. however, the evidence is still scarce in other regions in south america. acknowledgements this paper is dedicated to the memory of antonello bonadonna, for his dedication to the geology and the paleontology, its important contributions to geology and paleontology will always be remembered. the authors wish to express many thanks to giovanni zanchetta for your invitation to participate in this volume. the authors show gratitude to dan rafues, whose mother tongue is english, by revised the text. this work has been made possible thanks to research project anpcyt pict 2015-1512 to jlp; dgicyt cgl2016-79334-p from spain to mta; and grant of the national university of central argentina (unicen) to jlp. references alberdi m.t. (1987) la familia equidae, gray, 1821 (perissodactyla, mammalia) en el pleistoceno de sudamérica. in: iv congreso latinoamericano de paleontología, santa cruz de la sierra, bolivia, 1, 484-499. alberdi m.t., prado j.l. (1992) el registro de hippidion owen, 1869 y equus (amerhippus) hoffstetter, 1950 (mammalia, perissodactyla) en américa del sur. ameghiniana, 29, 265-284. alberdi m.t., prado j.l. (1993) review of the genus hippidion owen, 1869 (mammalia; perissodactyla) from the pleistocene of south america. zoological journal of the linnean society, 108, 1-22. alberdi m.t., prado j.l. (1998) comments on: pleistocene horses from tarija, bolivia, and validity of the genus onohippidium (mammalia: equidae) by b.j. macfadden. journal of vertebrate paleontology, 18(3), 669-672. alberdi m.t., prado j.l. (2004) caballos fósiles de américa del sur. una historia de tres millones de años. universidad del centro de la provincia de buenos aires, incuapa serie monográfica 3, olavarria pp. 269. alberdi m.t., fernández j., menegaz a.n., prado j.l. (1986) hippidion owen 1869 (mammalia, perissodactyla) en sedimentos del pleistoceno tardío de la localidad barro negro (jujuy, argentina). estudios geológicos, 42, 487-493. alberdi m.t., menegaz a.n., prado j.l. (1987) formas terminales de hippidion (mammal ia, perissodactyla) de los yacimientos del pleistoceno tardío holoceno de la patagonia (argentina y chile). estudios geológicos, 43, 107-115. alberdi m.t., prado j.l., ortiz jaureguizar e. (1995) patterns of body size changes in fossil and living equini (perissodactyla). biological journal of the linnean society, 54, 349-370. ameghino f. (1904) recherches de morphologie phylognetique sur les molaires supérieures des ongulés. anales del museo nacional, 3, 1-541. avilla l.s., bernardes c., mothé d. (2015) a new ge 52 alberdi m.t. & prado j.l. nus for onohippidium galushai macfadden bj, skinner mf, 1979 (mammalia, equidae), from the late hemphillian of north america. journal of vertebrate paleontology, 35(3) doi: 10.1080/02724634.2014.925909 barnosky a.d., lindsey e.l. (2010) timing of quaternary megafaunal extinction in south america in relation to human arrival and climate change. quaternary international, 217, 10-29. bernardes c., sicuro f.l., avilla l.s., pinheiro a.e.p. (2013) rostral reconstruction of south american hippidiforms (mammalia, perissodactyla, equidae): new anatomical and ecomorphological inferences. acta palaeontologica polonica, 58, 669678. borrero l.a. (1997) the extinction of the megafauna: a supra-regional approach. anthropozoology, 25 -26, 209-216. branco w. (1883) ueber eine fossile säugethierfauna von punin bei riobamba in ecuador. ii: beschreibung der fauna. palaeontologische abhandlunge, 1, 57-204. cantalapiedra j.l., prado j.l., hernádez fernández m., alberdi m.t. (2017) decoupled ecomorphological evolution and diversification in neogenequaternary horses. science, 355, 627-630. cerdeño e., moreiras s., alberdi m.t. (2008) primeros hallazgos del équido hippidion (perissodactyla) en el pleistoceno de la provincia de mendoza. revista del museo argentino de ciencias naturales, 10(2), 211-220. cerling t.e., harris m.j. (1999) carbon isotope fractionation between diet and bioapatite in ungulate mammals and implications for ecological and paleoecological studies. oecologia, 120, 347-363. cerling t.e., harris m.j., macfadden b.j., leakey m.g., quade j., eisenmann v., ehleringer j.r. (1997) global vegetation change through the miocene/pliocene boundary. nature, 389, 153158. cione l.a., tonni e.p. (1999) biostratigraphy and chronological scale of uppermost cenozoic in the pampean area, argentina. in: tonni e.p. & cione a.l. (eds.): quaternary vertebrate palaeontology in south america. quaternary of south america and antarctic peninsula, 12, 23-52. cione l.a., tonni e.p. (2005) biostratigrafía basada en mamíferos del cenozoico superior de la región pampeana. in: barrio r., etcheverry r.o., caballé m.f. & llambías e. (eds.): geología y recursos minerales de la provincia de buenos aires (relatorio del xv congreso geológico argentino, la plata, 11, 183-200. cione a.l., tonni e.p., soibelzon l. (2009) did humans cause the late pleistocene-early holocene mammalian extinctions in south america in a context of shrinking open areas? in: haynes g. (ed.): american megafaunal extinctions at the end of the pleistocene, springer, new york, 125-144. clark p.u., dyke a.s., shakun j.d., carlson a.e., clark j., wohlfarth b., mitrovica j.x., hostetler s.w., mccabe a.m. (2009) the last glacial maximum. science, 325, 710-714. coltorti m., pieruccini p., paredes rios f. (2010) late pleistocene stratigraphy, sedimentology and paleoenvironmental evolution of the tarija-padcaya basin (bolivian andes). proceedings of the geologist’s association, 121, 162-179. dantas m.a.t., dutra r.p., cherkinsky a., fortier d.c., kamino l.h.y., cozzuol m.a., ribeiro a.s., silva f.v. (2013) paleoecology and radiocarbon dating of the pleistocene megafauna of the brazilian intertropical region. quaternary research, 79, 61-65. der sarkissian c., vilstrup j.t., schubert m., seguin-orlando a., eme d., weinstock j., alberdi m.t., martin f., lopez p.m., prado j.l., prieto a., douady c.j., stafford t.w., willerslev e., orlando l. (2015) mitochondrial genomes reveal the extinct hippidion as an outgroup to all living equids. biology letters, 11(3), 20141058. domingo l., prado j.l., alberdi m.t. (2012) the effect of paleoecology and paleobiogeography on stable isotopes of quaternary mammals from south america. quaternary science reviews, 55, 103113. ehleringer j.r., cerling t.h. (2002) stables isotopes. in: mooney, h.a., canadell, j.g. (eds.): the earth system: biological and ecological dimensions of global environmental change, encyclopedia of global environmental change, vol. 2. john wiley and sons, ltd, chichester, pp. 544-550. eisenmann v. (1979) les métapodes d’equus sensu lato" (mammalia, périssodactyla). geobios, 12(6), 863-886. eisenmann v. (1984) sur quelques caractères adaptatifs du squelette d'equus" (mammalia, perissodactyla) et leurs implications paléoécologiques. bulletin du muséum national d'histoire naturelle de paris, 4(6), 185-195. eisenmann v., beckouche s. (1986) identification and discrimination of metapodials from pleistocene and modern equus, wild and domestic. in: meadow r.h., uerpmann h-p. (eds): equids in the ancient world, beihfte zum tübingen atlas des vorderen orients, reihe a, naturwissenschaften, 19 (1), 117-163. gaunitz c., fages a., hanghøj k., albrechtsen a., khan n., schubert m., seguin-orlando a., owens i.j., felkel s., bignon-lau o., de barros damgaard p., mittnik a., mohaseb a.f., davoudi h., alquraishi s., alfarhan a.h., al-rasheid k.a.s., crubézy e., benecke n., olsen s., brown d., anthony d., massy k., pitulko v., kasparov a., brem g., hofreiter m., mukhtarova g., baimukhanov n., lõugas l., onar v., stockhammer p.w., krause j., boldgiv b., undrakhbold s., erdenebaatar d., lepetz s., mashkour m., ludwig a., wallner b., merz v., merz i., zaibert v., willerslev e., librado p., outram a.k., orlando l. (2018) ancient genomes revisit the ancestry of domestic and przewalski’s horses. science, 360, 111-114. doi: 10.1126/science.aao3297 gokhman d., meshorer e., carmel l. (2016) epigenetics: it’s getting old. past meets future in paleoep 53 fossil horses from south america igenetics. trends in ecology & evolution, 31, 290300. hajdas i., bonani g., moreno p.i., ariztegui d. (2003) precise radiocarbon dating of late-glacial cooling in mid-latitude south america. quaternary research, 59(1), 70-78. hoffstetter r. (1950) algunas observaciones sobre los caballos fósiles de américa del sur. amerhippus gen. nov. boletín informativo de ciencias nacionales, 3, 426-454. hoffstetter r. (1952) les mammifères pléistocènes de la république de l'équateur. mémoires de la societé géologique de france, ns 31(1-4), 1-391. koch p.l. (2007) isotopic study of the biology of modern and fossil vertebrates. in: michener r., lajtha k. (eds): stable isotopes in ecology and environmental science, 2nd edition. boston: blackwell publishing. 99-154. koch p.l., barnosky a.d. (2006) late quaternary extinctions: state of the debate. annual review of ecology, evolution and systematics, 37, 215-250. krohling d.m., iriondo, m. (1999) upper quaternary palaeoclimates of the mar chiquita area, north pampa, argentina. quaternary international, 57/58, 149-163. librado p., gamba c., gaunitz c., der sarkissian c., pruvost m., albrechtsen a., fages a., khan n., schubert m., jagannathan v., serres-armero a., kuderna l.f.k, povolotskaya i.s., seguin-orlando a., lepetz s., neuditschko m., thèves c., alquraishi s., alfarhan a.h., al-rasheid k., rieder s., samashev z., francfort h-p., benecke n., hofreiter m., ludwig a., keyser c., marques-bonet c., ludes b., crubézy e., leeb t., willerslev e., orlando l. (2017) ancient genomic changes associated with domestication of the horse. science, 356, 442-445. lund p.w. (1840) nouvelles recherches sur la faune fossile du brésil. annales de sciences naturais, 13, 310-319. macfadden b.j. (1992) fossil horses. systematics, paleobiology, and evolution of the family equidae. cambridge university press, new york, pp. 369. macfadden b.j. (2013) dispersal of pleistocene equus (family equidae) into south america and calibration of gabi 3 based on evidence from tarija, bolivia. plosone, 8(3), e59277. macfadden b.j., azzaroli a. (1987) cranium of equus insulatus (mammalia, equidae) from the middle pleistocene of tarija, bolivia. journal of vertebrate paleontology, 7(3), 325-334. macfadden b., cerling t.e. (1996) mammalian herbivore communities, ancient feeding ecology, and carbon isotopes: a 10 millioneyear sequence from the neogene of florida. journal of vertebrate palaeontology, 16, 103-115. macfadden b.j., skinner m.f. (1979) diversification and biogeography of the one-toed horses onohippidium and hippidion. postilla, 175, 1-10. macfadden b.j., anaya f., argollo j. (1993) magnetic polarity stratigraphy of inchasi a pliocene mammal-bearing locality from the bolivian andes deposited just before the great american interchange. earth planetary sciences letters, 114, 229-241. macfadden b.j., higgins p., clementz m.t., jones d.s. (2004) diets, habitat preferences, and niche differentiation of cenozoic sirenians from florida: evidence from stable isotopes. paleobiology, 30 (2), 297-324. machado h., grillo o., scott e., avilla l. (2017) following the footsteps of the south american equus: are autopodia taxonomically informative? journal of mammal evolution, 25(3), 397-405. doi: 10.1007/s10914-017-9389-6 marsh o.c. (1874) notice of new equine mammals from the tertiary formation. journal of natural history, 13(77), 397-400. marshall l.g., hoffstetter r., pascual r. (1983) mammals and stratigraphy: geochronology of the continental mammal-bearing tertiary of south america. palaeovertebrata, me, 1-93. marshall l.g., berta a., hoffstetter r., pascual r., reig o.a., bombin m., mones a. (1984) mammals and stratigraphy: geochronology of the continental mammal-bearing quaternary of south america. palaeovertebrata, me, 1-76. mihlbachler m.c., rivals f., solounias n., semperbon g.m. (2011) dietary change and evolution of horses in north america. science, 331, 11781181. moreno f.p. (1891) onohippidium munizi. breve historia sobre los restos fósiles de un género nuevo de la familia de los equidae conservados en el museo de la plata. revista del museo de la plata, 2, 65-71. moreno bofarull a., arias royo a., hernández fernández m., ortiz-jaureguizar e., morales j. (2008) influence of continental history on the ecological specialization and macroevolutionary processes in the mammalian assemblage of south america: differences between small and large mammals. bmc evolutionary biology, 8 doi:10.1186/1471-2148-8-97 morrone j.j. (2014) – biogeographical regionalisation of the neotropical region. zootaxa, 3782(1), 1-110. orlando l., male d., alberdi m.t., prado j.l., prieto a., cooper a., hänni c. (2008) ancient dna clarifies the evolutionary history of american late pleistocene equids. journal molecular evolution, 66, 533538. orlando l., metcal j.l., alberdi m.t., telles-antunes m., bonjean d., otte m., martin f., eisenmann v., mashkour m., morello f., prado j.l., salas-gismondi r., shockeym b.j., wrinn p.j., vasil’ev s.k., ovodov n.d., cherry m.i., hopwood b., male d., austin j.j., hänni c., cooper a. (2009) revising the recent evolutionary history of equids using ancient dna. proceeding of the national academy of sciences usa, 106, 2175421759. ortiz jaureguizar e., cladera g. (2006) paleoenviron­ mental evolution of southern south america during 54 alberdi m.t. & prado j.l. the cenozoic. journal of arid environment, 66, 489-532. owen r. (1840) the zoology of the voyage of h.m.s. beagle under the command of captain fitzroy r.n. during the years 1832 to 1836. part i.fossil mammalia, ed superv c. darwin, pp. 81-111. owen r. (1869) on fossil teeth of equines from central and south america, referable to equus conversidens, equus tau, and equus arcidens. proceeding of the royal society of london, 17, 267-268. pascual r., ortega hinojosa e.j., gondar d., tonni e.p. (1965) las edades del cenozoico mamalífero de la argentina, con especial atención a aquellas del territorio bonaerense. anuario comisión de investigación científica, provincia de buenos aires, 6, 165-193. pascual r., ortega hinojosa e.j., gondar d., tonni e.p. (1966) las edades del cenozoico mamalífero de la provincia de buenos aires. in: borrello a.v. (ed.): paleontología bonaerense, comisión de investigaciones científicas de la provincia de buenos aires, 3-12. pascual r., ortiz jaureguizar e., prado j.l. (1996) land mammals: paradigm of cenozoic south american geobiotic evolution. münchner geowissenschaftlich abhandlungen, geologie paläontologie, a30, 265-319. prado j.l. (1984) fenética de los metatarsianos de taxa fósiles hippidion owen, onohippidium moreno, parahipparion c. ameghino y equus (amerhippus) linne (mammalia, perissodactyla). cipfe orione contribución biología, montevideo, 11, 11-15. prado j.l., alberdi m.t. (1994) a quantitative review of the horse equus from south america. paleontology, 37, 459-481. prado j.l., alberdi m.t. (1996) a cladistic analysis of the horses of the tribe equini. palaeontology, 39, 663-680. prado j.l., alberdi m.t. (2008) restos de hippidion y equus (amerhippus) procedentes de las barrancas de san lorenzo, pleistoceno tardío (provincia de santa fé, argentina). revista española de paleontología, 23(2), 225-236. prado j.l., alberdi m.t. (2012) equidos y gonfoterios del pleistoceno tardío de san pedro, provincia de buenos aires, argentina. estudios geológicos, 68 (2), 261-276. prado j.l., alberdi m.t. (2014) global evolution of equidae and gomphotheriidae from south america. integrative zoology, 9, 434-443. prado j.l., alberdi m.t. (2016) fossil horses from argentina. in: agnolin f.l., lio g.l., brissón egli f., chimento n., novas f.e. (eds.): historia evolutiva y paleobiogeográfica de los vertebrados de américa del sur, contribuciones científicas del museo argentino de ciencias naturales “bernardino rivadavia”, 6, 303-309. prado j.l., alberdi m.t. (2017) fossil horses of south america. phylogeny, systematics and ecology. the latin american studies book series, springer, pp. 150. prado j.l., alberdi m.t., reguero m.a. (1998) el registro más antiguo de hippidion owen, 1869 (mammalia, perissodactyla) en américa del sur. estudios geológicos, 54, 85-91. prado j.l., alberdi m.t., reguero m.a. (2000) comentarios sobre la geocronología, estratigrafía y paleontología de vertebrados de la fm. uquía en el perfil de esquina blanca, jujuy. respuesta a e.p. tonni y a.l. cione. estudios geológicos, 56, 133-137. prado j.l., sánchez b., alberdi m.t. (2011) ancient feeding ecology inferred from stable isotopic evi ­dence from fossil horses in south america over the past 3 ma. bmc ecology, 11, 1-15. prado j.l., alberdi m.t., di martino v.j. (2012) équidos y gonfoterios del pleistoceno tardío del sudeste de la provincia de buenos aires. ameghiniana, 49(4), 623-641. prado j.l., martínez-maza c., alberdi m.t. (2015) megafauna extinction in south america: a new chronology for the argentine pampas. palaeogeography, palaeoclimatology, palaeoecology, 425, 41-49. pérez-crespo a.v., prado j.l., alberdi m.t., arroyocabrales j., johnson e. (2016) diet and habitat for six american pleistocene proboscidean species using carbon and oxygen stable isotopes. ameghiniana, 71, 39-51. pérez-crespo a.v., prado j.l., alberdi m.t., arroyocabrales j. (2018) stable isotopes and diets of pleistocene horses from southern north america and south america: similarities and differences. palaeobiodiversity and palaeoenvironments, in press. reguero m.a., candela a.m. (2011) late cenozoic mammals from the northwest of argentina. in: salfity r., marquillas m.r. (eds.): cenozoic geology of the central andes of argentina, scs publishers, salta, pp. 411-426. reguero m.a., candela a.m., alonso r.n. (2007) biochronology and biostratigraphy of the uquía formation (pliocene-early pleistocene, nw argentina) and its significance in the great american biotic interchange. journal of south american earth science, 23, 1-16. saarinen j., eronen j., fortelius m., seppä h., lister a.m. (2016) patterns of diet and body mass of large ungulates from the pleistocene of western europe, and their relation to vegetation. palaeontologia electronica, 19(3), 1-58. sánchez b., prado j.l., alberdi m.t. (2004) feeding ecology, dispersal, and extinction of south american pleistocene gomphotheres (gomphotheriidae, proboscidea). paleobiology, 30(1), 146-161. savage d.e. (1962) cenozoic geochronology of the fossil mammals of the western hemisphere. revista museo argentino ciencias naturales "bernardino rivadavia", ciencias zoológicas, 8, 53‑67. schubert m., jónsson h., chang d., der sarkissian c., ermini l., ginolhac a., albrechtsen a., dupanloup 55 fossil horses from south america i., foucal a., petersen b., fumagalli m., raghavan m., seguin-orlando a., korneliussen t.s., velazquez a.m.v., stenderup j., hoover c.a., rubin c.j., alfarhan a.h., alquraishi s.a., al-rasheid k.a.s., machugh d.e., kalbfleisch t., macleod j.n., rubin e.m., sicheritz-ponten t., andersson l., hofreiter, marques-bonet t., gilbert m.t.p., nielsen r., excoffier l., willerslev e., shapiro b., orlando l. (2014) prehistoric genomes reveal the genetic foundation and cost of horse domestication. proceedings of the national academy of science usa, 111, e5661-e5669. sharov a.a. (2014) evolutionary constraints or opportunities? biosystems, 123, 9-18. shoemaker l., clauset a. (2014) body mass evolution and diversification within horses (family equidae). ecological letters, 17(2), 211-220. simpson g.g. (1951) history of the fauna of latin america. american science, 38 261-389. simpson g.g. (1953) horses. the story of the horse family in the modern world and through sixty million years of history. new york. oxford university press, pp. 247. simpson g.g. (1971) the evolution of marsupials in south america. annales academia brasileira de ciências, 43, 103-118. strömberg c.a.e. (2004) using phytolith assemblages to reconstruct the origin and spread of grassdominated habitats in the great plains during the late eocene to early miocene. palaeogeography, palaeoclimatology palaeoecology, 207(3-4), 239275. tauber a.a. (2005) mamíferos fósiles y edad de la formación salicas (mioceno tardío) de la sierra de velasco, la rioja, argentina. ameghiniana, 42 (2), 443-460. toledo m.j., schewnninger j-l., kinoshita a., baffa o., mangini a. (2014) dataciones osl, esr y u-th del sitio paleontológico spósito (san pedro, prov. de buenos aires, argentina). registro de los ois6/7 y ois5. xix congreso geológico argentino, junio 2014, córdoba, s13-6. toledo m.j., schewenninger j., kinoshita a., baffa o., mangiri a. (2015) is equus (a.) neogeus a valid index and exclusive taxon of the lujanian stage? sequence stratigraphy and new osl, esr and u -th dates of ois 7 to ois 2, san pedro, buenos aires province, argentina. xxix jornadas argentinas de paleontología de vertebrados, 1-2. tonni e.p., carlini a.a., scillato-yané g.j., figini a.j. (2003) cronología radiocarbónica y condiciones climáticas en la “cueva del milodón” (sur de chile) durante el pleistoceno tardío. ameghiniana, 40(4), 609-615. tonni e.p., soibelzon e., cione a.l., carlini a.a., scillato-yané g.j., zurita a.e., paredes ríos f. (2009) preliminar correlation of the pleistocene sequences of the tarija valley (bolivia) with the pampean chronological standard. quaternary international, 210, 57-65. vilstrup j.t., seguin-orlando a., stiller m., ginolhac a., raghavan m., nielsen s.c.a.,weinstock j., froese d., vasiliev s.k., ovodov n.d., clary j., helgen k.m., fleischer r.c., cooper a., shapiro b., orlando l. (2013) mitochondrial phylogenomics of modern and ancient equids. plosone, 8(2), e55950. doi: 10.1371/journal.pone.0055950 villavicencio n.a., lindsey e.l., martin f.m., borrero l.a., moreno p.i., marshall c.r,, barnosky a.d. (2016) combination of humans, climate, and vegetation change triggered late quaternary megafauna extinction in the última esperanza region, southern patagonia, chile. ecography, 39(2), 125140. vrba e.s. (1992) mammals as key to evolutionary theory. journal of mammalogy, 73, 1-28. wagner a. (1860) ueber fossile säugetierknochen am chimborasso. sitzugsbenchte der konigl bayenschen. akademie der wissenschapten z münchen, 330-338. webb s.d. (1991) ecogeography and the great american interchange. paleobiology, 17, 266-280. weinstock j., willersley e., sher a., tong w., ho s.y.w., simon y.w. ho1, rubenstein d., storer j., burns j., martin l., bravi c., prieto a., froese d., scott e., xulong l., cooper a. (2005) new world pleistocene horses: pruning the equid tree. plosbiol, 3(8), 1332-1333. wood h.e., chaney r.w., clark j., colbert e.h., jepsen g.l., reeside j.b., stock c. (1941) nomenclature and correlation of the north american continental tertiary. geological society of american bulletin, 52(1), 1-48. woodburne m.o. (2010) the great american biotic interchange: dispersals, tectonics, climate, sea level and holding pens. journal of mammalia evolution, 17, 245-264. ms. received: june 13, 2018 final text received: february 14, 2019 56 alberdi m.t. & prado j.l. imp. carobene ggeenneessii,, eettàà,, ssoolllleevvaammeennttoo eedd eerroossiioonnee ddeeii tteerrrraazzzzii mmaarriinnii ddii ccrroossiiaa--ccaallooppeezzzzaattii ((ccoossttaa iioonniiccaa ddeellllaa ccaallaabbrriiaa--iittaalliiaa)) lluuiiggii ccaarroobbeennee dip.te.ris., università degli studi, corso europa, 26 – 16132 genova riassunto sono stati studiati i terrazzi marini del settore costiero ad est del fiume trionto, nel territorio di crosia e di calopezzati, ai piedi del versante nordorientale del massiccio della sila. il substrato tagliato dai terrazzi è costituito da una successione marina pleistocenica, prevalentemente sabbiosa alla base e argillosa nella parte alta; a monte, le sabbie basali pleistoceniche poggiano in discordanza su argille e arenarie mioceniche. nell’area (di circa 17 km2) sono presenti superfici terrazzate raggruppabili in 4 ordini distinti: il i ordine è rappresentato da relitti di superfici, molto degradate, estese tra 131 e 210 m di quota lungo stretti crinali disposti n-s; gli originari depositi terrazzati sono documentati da piccoli lembi di sabbie, ghiaie e calcari detritici algali ben cementati. il ii ordine è rappresentato da relitti di superfici terrazzate estesi tra 80 e 120 m di quota; i corpi sedimentari terrazzati sono costituiti da depositi sia marini che continentali aventi uno spessore complessivo massimo di 45 m. il iii ordine è rappresentato da superfici abbastanza ben conservate, estese tra 55 e 75 m di quota; il deposito terrazzato, sia marino che continentale, raggiunge lo spessore massimo di 25 m. il iv ordine è presente con superfici terrazzate poco estese, aventi margine interno a 25-30 m, dove sono raramente riscontrabili esigui spessori di sabbie e ghiaie. i corpi terrazzati del ii e del iii ordine hanno fornito, grazie al loro spessore, nuovi elementi per comprendere genesi e significato dei terrazzi marini. i lembi del ii ordine iniziano con un debole spessore di ciottoli arrotondati trasgressivi, per svilupparsi poi verso l’alto e lateralmente con corpi progradanti di diversa litologia ed ambiente, in eteropia di facies tra loro. da mare verso terra sono riconoscibili: peliti sabbiose di spiaggia sottomarina di transizione; sabbie clinostratificate di spiaggia sottomarina; ghiaie sabbiose di battigia e di spiaggia emersa. nella parte più interna del terrazzo è sempre presente un corpo lenticolare da dulcicolo a salato, chiuso verso mare dalle tre unità litologiche marine sopra descritte e avente spessori massimi di 15 m. nella parte alta sono presenti infine sabbie di battigia o di spiaggia emersa migrate verso terra fino a ricoprire le peliti dulcicolo-salmastre. la successione è chiusa da 5-6 m di conglomerati continentali pedogenizzati. i corpi terrazzati del iii ordine, pur avendo uno spessore minore, mostrano sorprendenti analogie con la situazione stratigrafica descritta per il ii ordine. le osservazioni geometriche e stratigrafiche effettuate sui terrazzi marini ad est del fiume trionto hanno permesso: di riconoscere nei depositi terrazzati 9 litofacies principali; di applicare la stratigrafia sequenziale ai depositi del ii e del iii ordine di terrazzi; di riconoscere nei depositi pelitici di retrobarriera fasi di emersione e di sommersione; di determinare la corrispondenza tra terrazzi e stadi isotopici marini (mis), e quindi la loro età; di comprendere il ruolo giocato dal substrato argilloso nel processo trasgressivo e l’importanza degli apporti detritici nello sviluppo del sistema barriera-laguna. l’analisi dei caratteri geometrici delle superfici inferiori di erosione marina ha permesso inoltre di caratterizzare con nuovi criteri descrittivi i terrazzi, ad esempio con il “rapporto sollevamento/distanza” ed il “rapporto distanza/età” delle antiche linee di riva; considerazioni sulle curve climatiche ed eustatiche hanno consentito di calcolare la “velocità di arretramento delle falesie argillose” e di riconoscere la “corrispondenza terrazzo marino-alto picco eustatico interglaciale”. la tettonica ha controllato l’evoluzione dei terrazzi mediante il sollevamento, risultato pari a 0,5 mm/a circa, e con gruppi ben precisi di lineamenti tettonici. dal punto di vista metodologico si propongono infine nuovi schemi per la descrizione e la nomenclatura dei terrazzi ed un quadro completo dei processi che intervengono nel rimodellamento degli antichi terrazzi sollevati. abstract the marine terraces of the coastal sector at the foot of the north-eastern slope of the massiccio della sila, east of the trionto river, between crosia and calopezzati (ionian coast of calabria) were the subject of this study. the terraces cut through a substratum consisting of a pleistocene marine succession, the base of which is sandy-pebbly and the rest clayey-silty; the layers dip towards the nne at an angle of 10°-20°; uphill the basal pleistocene sands lay discordantly on miocene clays and sandstones. the miocene-pleistocene sequence that crops out along the ionian coast of calabria today constitutes the proximal part of the sedimentary filling of a basin caused by the subduction of the african lithospheric plate under the calabrian arch, a complex chain consisting of a thrust-sheet of continental origin and ophiolite-bearing units. the dramatic uplift that sila (like serre and aspromonte further south) is undergoing in the quaternary is contributing to the partial emergence of this miocene-pleistocene sedimentary wedge, is causing the terracing along the tyrrhenian and ionian coasts and is provoking the strong seismicity of calabria today. in the area studied, in particular, 4 orders of marine terraces are identifiable and have been the subject of morphological and sedimentological research (fig. 1) the 1st order is represented by very remodelled relics lying between altitudes of 131 and 210 m; the 2nd by the remnants of terraced surfaces lying between altitudes of 80 and 120 m; the 3rd by fairly-well preserved surfaces lying between altitudes of 55 and 75 m, and the 4th by surfaces lying between altitudes of 20 and 30 m. the conclusions drawn from data collected are synthesised as follows: 1)aa ddeettaaiilleedd nnoommeennccllaattuurree has been proposed to describe the genetic, geometric and morphological characteristics of the terraces and those derived from their remodelling, above all in the presence of a terraced body of a certain thickness (scheme in fig. 31). 2)tthhee aaggee of each terrace has been established, considering that it is not the result of a single sea level highstand, but of “an interglacial eustatic peak”. the chronology of the four orders of terraces in the area (fig. 1) is as follows: 1st order (+210 m) = stages 9+11; 2nd order (+105÷120 m) = stage 7e; 3rd order (+64÷71 m) = stage 5e, 4th order (+25÷30 m) = substages 5a-5c. the uplift rate is 0.5 mm/yr (tab.1). 3)tthhee ssuubbssttrraattuumm, which consists of early-middle pleistocene silty clays in the area studied, played a determining role in the transgressive process. the lithology of the substratum influenced the generation and rapid retreat of the seacliffs (see point 10), and also favoured the development of an “erosion marine platform” rather than an abrasion one. il quaternario italian journal of quaternary sciences 1166(1), 2003, 43-90 44 l. carobene 11.. pprreemmeessssaa l’area oggetto della presente ricerca è ubicata ai piedi del versante nordorientale del massiccio della sila, lungo la costa ionica della calabria settentrionale. la sila, assieme ai massicci delle serre e dell’aspromonte posti più a sud, fa parte dell’arco calabro, una catena orogenica complessa, costituita da unità tettoniche sovrascorse dal cretaceo inferiore al paleocene con vergenza europea, che a loro volta si accavallano a partire dal miocene inferiore sulla catena appenninica in via di formazione. l’edificio alpino e quello appenninico, ormai saldati tra loro, sovrascorrono in toto sui depositi dell’avanfossa (verso est) nella fase medio-pliocenica. la paleocatena europavergente è costituita in basso da unità ofiolitifere metamorfosate (crosta oceanica della tetide) e in alto da unità metamorfiche di margine continentale (basamento ercinico metamorfico con intrusioni granitoidi). il settore orientale della sila è occupato dall’unità di longobucco, priva di metamorfismo alpino, che conserva una copertura sedimentaria meso-cenozoica (da gasperi, 1995). i primi studi nell’area risalgono all’800 (cortese, 1895; fucini, 1896 e lovisato, 1878); contributi geologici a carattere generale sono stati forniti da ogniben (1962), selli (1962) e da roda (1967); ricerche stratigra4)the terraced deposits have diversified lithologies; and so it is possible to distinguish 99 lliitthhooffaacciieess,, correlatable to various beach environments. these are (figs. 6, 14, 20, 25): (cb) transgressive basal conglomerate; (pm) marine pelites; (si) lower grey sands; (ags) alternating gravel and sand; (ss) upper yellow sands; (pds) fresh-water, brackish and lagoon pelites; (c.a.-a.-c.c.) arenaceous limestones-bioturbate sandstones-calcareous shellstones; (ca) algal limestones; (cc) continental conglomerates. 5)the great thickness that characterises the deposits of the 2nd order of terraces (up to 45 m) and the 3rd (up to 25 m), and their division into distinct lithofacies that distinguish the sedimentary bodies between them in a heteropy of facies, makes it possible to easily identify ttwwoo ddeeppoossiittiioonnaall sseeqquueenncceess (for both orders) indicative of a coastal barrier-lagoon system. in fact, a transgressive systems tract (tst) and a highstand systems tract (hst), divided by a “maximum flooding surface” (mfs) are identifiable (fig. 33). the regressive depositional system was probably destroyed by the genesis of the most recent terraces. the hst deposit was formed by the strong progradation of the beach ridge, accompanied by aggradation; this would have determined the development of wide back-barrier lagoon or fresh-water basins. 6)the stratigraphic analysis of the pelitic successions (pds) characteristic of the back-barrier basins mentioned above highlight periods of emersion (paleosoil) and submersion (transgressive beach deposits) (fig. 22) these testify to eustatic oscillations during the period of the “interglacial eustatic peak” and the consequent ppoollyypphhaassee ggeenneessiiss of the 2nd and 3rd orders. 7)the generation of the marine terraces occurred at the end of the middle and during the late pleistocene, in an extended deformational regime characterised by uplift (0.5 mm/yr) and the recommencement of fault activity. this favoured erosion and the production of detritus; the abundant ddeettrriittaall ssuuppppllyy of the trionto river caused the accentuated progradation of the paleobeaches and the formation of the lagoon-barrier systems, as documented by the 2nd and 3rd orders of terraces. 8)in the area studied each order of terraces was formed, at least in part, at the expense of the order immediately above it (fig. 6, 14, 20). thus, each terrace utilised a considerable quantity of the marine and continental sediments from the terraced deposit immediately above it during its formation. tthhee rreeccyycclliinngg of these clastic sediments influenced the generation of the lower transgressive surfaces of the terraces and explains the carpet of large pebbles (fig. 34) covering them (the surface is cut into the clays of the substratum) and the presence of rounded blocks of algal limestone coming from the 1st order of terraces (ca lithofacies) in those of the 2nd, 3rd and 4th orders. 9)during the uplifting of the area, the high eustatic levels of the last interglacials created the characteristic stepped terracing of the area (fig. 36). in this way the ancient coastlines of the 1st, 2nd, 3rd and 4th orders were gradually “distanced” from the actual coastline of today. the rraattiioo ooff uupplliifftt::ddiissttaannccee that can be calculated for each coastline gives angular values varying between 2.1° and 3°. instead, the rraattiioo ooff ddiissttaannccee::aaggee gives values of the “velocity of distancing” for each coastline varying between 1 and 1.5 cm/yr. 10)our detailed knowledge of the width of the lower erosion surfaces of the terraces and the thickness of the terraced marine deposits make it possible to calculate tthhee vveelloocciittyy ooff tthhee sseeaacclliiffffss rreettrreeaatt of the terraces of the 2nd and 3rd orders. the deposits of these two terraces are transgressive in the lower part and progradant-aggradant in the upper part; thus they can be linked to the “first semiamplitude of a eustatic and climatic oscillation” (which lasted approximately 7,500-10,000 years) (fig. 37). a comparison with the eustatic uplift curve of the last interglacial makes it possible to indirectly deduce the times from the paleocurves and to calculate the partial times of the transgressive phases and the highstand. the rates of the retreat of the seacliffs are reported in tab. 2; the mean values are 11 and 9 cm/yr for the 2nd and 3rd orders respectively, while the values referring to the transgressive tract of the lower surfaces only are 34 and 38 cm/yr respectively. 11)the polyphase genesis of a “terrace” (3.6.) requires long time periods that are compatible with an entire interglacial period, to which an iinntteerrggllaacciiaall eeuussttaattiicc ppeeaakk corresponds. the climatic oscillations into which an interglacial period is divided can produce single sseeaa lleevveell hhiigghhssttaannddss (of much shorter time spans and different elevations) to which single and well-defined “shorelines” correspond (tab. 3). 12)tteeccttoonniiccss. the generation and evolution of the terraces were tectonically checked using : a) the ratio of eustatic rise:tectonic uplift; b) the tectonic uplift (equal to 0.5 mm/yr) that raised the most ancient terrace (1st order) to an altitude of 210 m; c) the presence of faults or fractures along which erosion has worked during the different phases of the remodelling of the terraces. the tectonic lineaments have the following mean directions: n26°, 40°, 60°, 120° and 140° (fig. 38). 13)after the uplift and emersion the terraces underwent rreemmooddeelllliinngg, the oldest being the most degraded. the processes operating during the remodelling were of various types that can act for hundreds of thousands of years, but were not continuous as they are dependent on periodic climatic variations. schematising an uplifted marine terrace as in fig. 41, it is possible to highlight 6 groups of processes that operated on 6 distinct surfaces: (pf) paleocliff; (ss) upper surface of the terrace, (fa) active cliff; (v.v.) valley slopes; (f.v.) valley bottom, (f.c.) coastal area. the final complex effect is to reduce the area of the upper surface of the terrace, which can become one narrow ridge (tract of one drainage divide with subhorizontal trend) or divide itself into more or less isolated culminations of similar height. over a long period the processes described in fig. 41 lead to the complete destruction of the terrace. parole chiave:terrazzi marini, depositi terrazzati, eustatismo, antiche linee di riva, erosione costiera, tettonica quaternaria, pleistocene, calabria.. keywords: marine terraces, terrace deposits, depositional sequences, eustasy, paleoshorelines, seacliffs retreat, quaternary tectonics, pleistocene, calabria, italy. 45genesi, età, sollevamento ed erosione ... fiche e morfologiche sul quaternario sono state condotte da panizza (1966 e 1967) e più recentemente dal gruppo nazionale di geografia fisica e geomorfologia (1995), che ha prodotto una carta geomorfologica al 50.000. l’area è inoltre coperta dai fogli al 25.000 della carta geologica della calabria (capo trionto, f° 230-ino e calopezzati, f° 230-i-so). ciaranfi et alii (1983), ghisetti & vezzani (1981), scandone (1982) e tortorici et alii (1995) hanno infine condotto ricerche sulla tettonica e la geodinamica dell’arco. l’intensa attività tettonica che si manifesta nel quaternario produce un notevole sollevamento di sila, serre e aspromonte, contribuendo all’emersione parziale del riempimento sedimentario del bacino calabro-ionico di età miocenico-quaternaria; provoca la formazione di terrazzi marini lungo le coste tirreniche e ioniche; innesca una intensa attività erosiva dei rilievi ed è causa della forte sismicità che caratterizza la calabria. le ricerche sui terrazzi marini di crosiacalopezzati, seppure in un’area molto ridotta, hanno portato un contributo alla conoscenza degli eventi sedimentari, climatici, eustatici, morfologici e tettonici avvenuti nella parte finale (pleistocene medio e superiore) di questa complessa storia geologica. sulla base di questa (e di precedenti esperienze) si è cercato inoltre di dare un contributo metodologico alla descrizione dei terrazzi e alla definizione della nomenclatura. l’area indagata si estende ad est del f. trionto; essa è caratterizzata da una linea di costa con andamento circa no-se condizionato da faglie (v. cap. 3.12.). la piana costiera è ben sviluppata nell’ala orientale del delta del f. trionfo, ma si riduce fin quasi a sparire verso se. nell’area crosia-calopezzati è stata studiata in dettaglio (dallo scrivente) anche la stratigrafia del substrato pleistocenico, che sarà oggetto di una prossima nota. questo studio è risultato fondamentale per il riconoscimento dei corpi terrazzati marini, che poggiano in netta discordanza sul substrato argilloso. 22.. ddeessccrriizziioonnee ddeeii tteerrrraazzzzii lo studio dei relitti morfologici di superfici terrazzate e dei lembi di depositi terrazzati disposti tra 20 e 220 m s.l.m. ha portato al riconoscimento di 4 ordini di terrazzi. ciò è avvenuto mediante la correlazione tra i diversi relitti, che ha dovuto tener conto di leggere variazioni di quota che essi manifestano lungo il tratto di costa esaminato; le differenze sono dovute in parte alla tettonica, in parte al diverso spessore della copertura continentale che sovrasta il corpo terrazzato marino, in parte al diverso grado di erosione subìto. in secondo luogo, i corpi terrazzati sono risultati litologicamente complessi, con variazioni di facies sia verticali che laterali. per tali ragioni la descrizione dei terrazzi verrà effettuata per “settori” a partire da occidente e per singoli “ordini” a partire dal più alto; la descrizione per settori non è stata effettuata per il terrazzo del i ordine per scarsità di dati. l'interpretazione ambientale dei differenti corpi sedimentari riconosciuti è stata effettuata mediante lo studio delle microfaune, in particolare per quanto riguarda i depositi pelitici sia marini che di retrobarriera (gruppo di bologna: colalongo, pasini, vaiani). l'esposizione dei dati micropaleontologici viene tuttavia rimandata ad una prossima nota; i depositi di retrobarriera hanno fornito faune da dolci a salate. nel caso dei depositi sabbiosi o ghiaiosi il riconoscimento degli ambienti è stato reso possibile dall'analisi delle strutture sedimentarie (embriciatura, classazione, laminazione ecc. e, a volte, dalla presenza di gusci di lamellibranchi). quanto detto vale anche per i depositi terrazzati del iii ordine. 22..11.. rreelliittttii ddeell tteerrrraazzzzoo ddeell ii oorrddiinnee,, ccoonn lliinneeaa ddii rriivvaa aa cciirrccaa 221100 mm questo ordine è documentato da alcuni relitti di superfici terrazzate corrispondenti a tratti suborizzontali di crinali in località calopezzati, da culminazioni topografiche a quote simili disposte lungo il crinale crosiastazione di mirto crosia e, lungo lo stesso crinale, da pochi lembi di depositi terrazzati marini (fig. 1). questi relitti sono complessivamente compresi tra le quote di 130 e 210 m; l’intervallo altimetrico piuttosto ampio può trovare giustificazione nelle faglie riconosciute nell’area (cap. 3.12.). non è direttamente dimostrabile che i relitti si possano riferire a più ordini di terrazzi diversi, tenendo anche conto (da rilevamenti dello scrivente) che in sinistra del f. trionto il terrazzo del i ordine appare meglio rappresentato tra 160 e 215 m di quota, con superfici terrazzate abbastanza estese (in particolare piano bùcida, tra 170 e 207 m), cui fa seguito direttamente il terrazzo del ii ordine, esteso tra 85 e 130 m (vedi anche cap. 3.8.). l’ipotesi che esso in verità derivi dalla fusione di due distinti terrazzi di età diversa, verrà avanzata nel successivo cap. 3.2. il corpo originario del terrazzo, oltre che dislocato da faglie circa ne-so (4042°) e no-se (117-122°), risulta ampiamente smantellato dallo sviluppo e dall’approfondimento della rete idrografica, complice la natura argillosa del substrato. il terrazzo è rappresentato in fig. 2 dal profilo eseguito lungo il crinale n-s, esteso tra cozzo s. pietro e stazione di mirto crosia, ma la descrizione dei suoi vari aspetti è stata fatta utilizzando tutti i dati disponibili nell’area esaminata. a) aspetti geometrici la superficie inferiore del terrazzo è stata ricostruita geometricamente (profilo b in fig. 2), tenendo conto delle faglie che la dislocano. in località calopezzati (fig. 1) il margine interno è probabilmente sollevato fino a 220-230 m, dove sono stati ritrovati depositi ciottolosi. in base a tale ricostruzione, l’ampiezza massima del terrazzo risulta di 2300 m, comparabile con quella osservata in sinistra trionto, dove raggiunge un valore di circa 2500 m. si tratta quindi di una superficie notevolissima; considerando le quote del margine interno a 207 m e dell’orlo esterno a circa 130 m (dislivello che risente dell’effetto delle faglie), la sua inclinazione risulta di 1,9°; eliminando i rigetti delle faglie il valore originario doveva però essere minore, probabilmente simile a quello degli ordini più bassi, e pertanto compreso tra 0,5° e 1°. in ogni caso il valore d’ inclinazione della superficie terrazzata (geometricamente ricostruita) si stacca nettamente da quello della paleofalesia degradata a monte, che risulta pari a 8,5° (profilo b in fig. 2). la superficie inferiore di erosione marina taglia in discordanza il substrato pleistocenico argilloso che presenta immersioni degli strati verso nne, con inclinazioni variabili tra 10 e 15 gradi. la faglia a 118° (vedi profilo a 46 l. carobene fig. 1 distribuzione dei 4 ordini di terrazzi marini riconosciuti lungo il tratto di costa studiato; è riportata la suddivisione in settori, utilizzati per le descrizioni nel cap.2. 1) relitti meglio conservati (indipendentemente dal loro ordine) delle superfici superiori (ss.r.), caratterizzati da culminazioni topografiche e da ripiani a debole pendenza. nei settori occidentali il terrazzo del i ordine è testimoniato da un esteso crinale (linea tratteggiata tra le quote di 207 e di 131 m) lungo il quale vi sono “relitti morfologici” (q. 168) privi di depositi e “lembi di depositi” (q. 169, 155 e 131), la cui estensione areale coincide con la ss. (fig. 2). le superfici del iv ordine (t1-t7) sono spesso prive di depositi. 2) distribuzione dei depositi terrazzati del ii ordine; i singoli lembi sono caratterizzati da superfici superiori ampiamente rimodellate (in nero). il substrato è costituito dalle argille pleistoceniche. 3) distribuzione dei depositi terrazzati del iii ordine; in destra del t. fiumarella questo ordine è molto ridotto o assente (paragr. 2.2.3.). da notare il differente rapporto tra 1) e 2) per i terrazzi del ii e per quelli del iii ordine. 4) paleolinee di riva ricavate correlando i dati dei singoli lembi terrazzati. 5) piede dei versanti. 6) isoipse con equidistanza di 50 m, ricavate dalle carte al 10.000 della regione calabria (f.230-i n.o. sez.b-stazione di mirto crosia e f.230-i s.o. sez.acalopezzati). distribution of the 4 orders of marine terraces identified along the coastal tract studied; the subdivision into sectors used for the description in chapt. 2 is reported here. 1) better preserved remains of the upper surfaces (ss.r), characterised by topographic culminations and gently sloping surfaces. in the western sectors the terrace of the 1st order testifies to a long ridge (broken line) along which there are “morphological remains” (height 168 m) without deposits and “remains of deposits” (height 169, 155 and 131 m) (fig. 2). the surfaces of the 4th order (from t1 to t7) are often without deposits. 2) distribution of deposits of the 2nd order; the isolated remains are characterised by extensively reworked upper surfaces. the substratum consists of pleistocene clays. 3) distribution of terraced deposits of the 3rd order; this order is much reduced or absent to the right of the fiumarella torrent (paragraph 2.2.3). the different ratio between 1) and 2) for the terraces of the 2nd and 3rd orders should be noted. 4) paleocoastline deduced from the data of the isolated terraced remains. 5) foot of the slopes. 6) contour lines with 50 m intervals, taken from the 1:10,000 map of calabria (f.230-i n.o. sect. b-stazione di mirto crosia and f.230-i s.o. sect. acalopezzati). 47genesi, età, sollevamento ed erosione ... f ig . 2 aa ) p ro fil o de l c rin al e co m pr es o tr a c oz zo s . p ie tr o (2 77 m ) e la c ul m in az io ne d i q uo ta 1 31 m ( tr ac ci a in f ig . 1 ); il d is eg no d er iv a da lla p ro ie zi on e de i d at i t op og ra fic i s u un p ia no v er tic ale d is po st o n -s . in b as e ai r el itt i m or fo lo gi ci e a i po ch i le m bi d el d ep os ito m ar in o te rr az za to è s ta to p os si bi le r ic os tr ui re g eo m et ric am en te i l te rr az zo . in bb )) è rip or ta ta l a su pe rf ic ie i nf er io re (s i.g .) , ch e si p re se nt a di sl oc at a da lle f ag lie r ic av at e ne l c or so d el p re se nt e la vo ro ( f ig . 38 ); c iò r en de d iff ic ile s ta bi lir e se a lc un i s ca lin i s ia no le ga ti al t er ra zz am en to o rig in ar io o pp ur e ai s uc ce ss iv i e ffe tti d el la t et to ni ca . e ’ v er os im ile c om un qu e ch e il te rr az zo s ia c om po si to , ci oè f or m at o da gl i a lti e us ta tic i d eg li st ag es 9 e 1 1 (c ap . 3. 2. e 3 .9 .) . la p al eo lin ea d i r iv a (p lr .g .) s i p uò co llo ca re a c irc a 21 0 m d i a lte zz a. i de po si ti so no d es cr itt i a l p ar ag r. 2 .1 . a ) p ro fil e of th e rid ge b et w ee n c oz zo s . p ie tr o (2 77 m ) an d th e cu lm in at io n of th e he ig ht o f 1 31 m ( lin e in f ig . 1 ); th e de si gn is d er iv ed fr om th e pr oj ec tio n of th e to po gr ap hi c da ta o nt o a ve rt ica l p la ne d is po se d n -s . t he r id ge is t he o nl y te st im on y to t he t er ra ce o f th e 1st o rd er in s ec to rs 1 a nd 2 ; ho w ev er , it ha s be en a lm os t to ta lly d es tr oy ed b y re m od el lin g. o n th e ba si s of t he m or ph ol og ic al r em ai ns a nd t he f ew r el ic s of t he t er ra ce d m ar in e de po si t it ha s be en p os si bl e to g eo m et ric al ly r ec on st ru ct t he t er ra ce . bb ) t he l ow er s ur fa ce s (s l.g .) a re d is lo ca te d by f au lt sy st em s de du ce d in t he c ou rs e of t he p re se nt w or k (f ig . 38 ); t hi s m ak es it d iff ic ul t to e st ab lis h w he th er a ny o f th e st ep s ar e as so ci at ed w ith t he o rig in al t er ra ci ng . h ow ev er , it is p ro ba bl e th at th e te rr ac e w as t hu s co m po se d, t ha t is f or m ed b y th e eu st at ic h ig hs o f st ag es 9 a nd 1 1 (c ha pt . 3. 2. a nd 3 .9 .) . t he p al eo sh or el in e (p lr .g .) c an b e pl ac ed a t an a lti tu de o f ab ou t 21 0 m . t he de po si ts a re d es cr ib ed in p ar ag ra ph 2 .1 . t he m or ph ol og ic al s ym bo ls a re in f ig . 3 1. 48 di fig. 2) separa il corpo argilloso a nord dalle sabbie basali pleistoceniche a sud; nel blocco compreso tra le faglie 117° e 118° gli strati sabbiosi inclinano di 20-30°. un’ultima considerazione riguarda la diminuzione di larghezza del terrazzo da no a se, analogamente a quanto verrà meglio spiegato per gli ordini più bassi (paragr. 2.2.3.): nel settore di calopezzati infatti l ’ampiezza è inferiore a 600 metri. b) aspetti litologici il corpo terrazzato marino compare con spessori assai ridotti e frammentato in piccoli lembi relitti; essi sono ancora osservabili sulle culminazioni di quota 169, 155 (fig. 3) e 131 m presenti nella parte esterna del terrazzo (profilo a di fig. 2). nella parte più alta, invece, compaiono depositi ciottolosi a crosia (207 m) e a calopezzati (tra 210 e 230 m): i clasti sono arrotondati, di varia natura litologica, eterometrici, con diametri che arrivano a superare i 50 cm. il deposito di quota 169 m. consiste in 3-4 m di conglomerati molto alterati, poggianti direttamente sul substrato argilloso pleistocenico. il colore rilevato è compreso tra 2,5 yr-3/6 e 5yr-4/6. i clasti, composti da arenarie, graniti e quarzo, sono arrotondati, con diametri che possono arrivare a 50 cm. il deposito di quota 155 m. è caratterizzato da diversi metri di ghiaie, fino a 5-6 m, con ciottol i arrotondati eterometrici aventi diametri massimi fino a 50-100 cm! localmente è possibile osservare alla base sabbie quarzose fini e medie, classate, laminate; al tetto invece relitti di un banco di calcari algali bioclastici, vacuolari, ben cementati. situazioni stratigrafiche simili a quella descritta sono state osservate in sinistra trionto (circa alle stesse quote), dove banchi organogeni ad alghe risultano compresi tra depositi ciottolosi. la presenza di “calcari algali” doveva essere in origine ben più consistente, in quanto è possibile osservare sui versanti immediatamente sottostanti numerosi blocchi metrici di calcari; i blocchi non si presentano l. carobene fig. 3 terrazzo del i ordine; settore 1°. sono visibili le due culminazioni topografiche a 169 e a 155 m sul l.m. (vedi profilo in fig. 2). c) deposito ciottoloso pedogenizzato (visibile anche in primo piano), poggiante sulle argille a) del substrato. terrace of 1st order; sector 1. the two topographic culminations at 169 and 155 m are visible (see profile in fig. 2). c) pedogenised pebbly deposit (also visible in the foreground), lying on the clays (a) of the substratum. fig. 4 sezione sottile che mostra un aspetto dei calcari algali affioranti localmente in corrispondenza dei lembi relitti del i ordine di terrazzi. le sezioni viste mostrano frammenti di briozoi, di molluschi e di serpulidi; radioli di echinidi; tra i foraminiferi miliolidi, acervulinidi ed elphidium. caratteristica la presenza di alghe calcaree rosse; l’associazione è poco diversificata, con grande abbondanza di corallinacee incrostanti riferibili ai generi titanoderma, spongites, mentre in subordine sono lithothamnion e mesophylum. tra le corallinacee articolate sono presenti rari segmenti di amphiroa. le alghe si presentano sia come talli incrostanti un sedimento sabbioso, sia come piccole rodoliti, anche centimetriche, immerse nella sabbia fine. nella fotografia è visibile il particolare di un tallo sottile di titanoderma sp. instauratosi su sedimento detritico (ingr. 50 volte circa camp. sx 3). thin section showing the features of algal limestones locally outcropping in the 1st order of terraces. the sections examined contain fragments of bryozoans, molluscs and serpulids, echinoid spines, and miliolids, acervulinids and elphidium among the foraminifera. the presence of calcareous red algae is a common character; the association is poorly diversified, with a great abundance of nongeniculate corallinaceae associated with the genera titanoderma and spongites, with minor lithothamnion and mesophyllum. there are a very few intergenicula of amphiroa among the geniculate corallinaceae. the algae are present as thalli encrusting a sandy sediment and small rhodoliths, even centimetric, scattered in fine sand. a close-up of a thin thallus of titanoderma sp. is visible on detrital sediment in the photograph (50x – camp. sx 3). arrotondati e non sono perforati da litodomi. non sono quindi blocchi rimaneggiati, ma semplicemente scivolati in basso lungo i versanti argillosi; nei depositi conglomeratici dei terrazzi più bassi non è infrequente trovare blocchi di calcari algali, ma in questo caso essi si presentano arrotondati e forati dai litodomi (cap. 3.8.). il deposito di quota 131 m. è costituito da un lembo relitto di un banco spesso 2-3 m di calcare bioclastico algale, ben cementato, vacuolare, non forato da litodomi (fig. 4). il “piastrone” sembra poggiare direttamente sulle argille del substrato; è ricoperto per 3-4 m da un deposito ruditico rubefatto di ciottoli in prevalenza arenacei e quarzosi. anche in questo caso sono presenti lungo i versanti sottostanti blocchi scivolati di calcare algale (fig. 5). una stratigrafia analoga è stata osservata in sinistra trionto (località serra campo, quota 170 m circa), dove al banco organogeno di 2-3 m fanno seguito ghiaie ben lavate, gradate, passanti verso l’alto a sabbie grosse, classate, marine. c) considerazioni ambientali il terrazzo del i ordine si presenta estremamente degradato; i pochi relitti che lo testimoniano permettono di fare solamente alcune considerazioni. innanzi tutto la sua grande ampiezza (2,3 km) lascia intuire che le condizioni della sedimentazione dovevano differenziarsi: verso riva prevaleva sicuramente l’apporto clastico terrigeno, mentre al largo esistevano condizioni più favorevoli alla sedimentazione organogena, ben compatibile con la formazione dei calcari algali descritti. in secondo luogo la bassa inclinazione del fondo (0,5-1°) permetteva, in corrispondenza di oscillazioni eustatiche anche lievi, rapide regressioni o trasgressioni che hanno originato le brusche variazioni di facies osservate, da ghiaie a calcari organogeni e viceversa. in terzo luogo gli “scalini” che la superficie del terrazzo presenta (profili a e b di fig. 2), attribuiti a faglie che hanno agito anche sui terrazzi più bassi e che hanno dislocato il substrato, potrebbero in parte trovare origine dall’azione di più stazionamenti del mare a quote diverse. questo argomento verrà ripreso successivamente (cap. 3.11.) 22..22.. llee ssuuppeerrffiiccii tteerrrraazzzzaattee ddeell iiii oorrddiinnee,, ccoonn lliinneeaa ddii rriivvaa aa 110055÷÷112200 mm la descrizione dei terrazzi del ii ordine viene distinta in 3 settori, da no a se, e in un settore interno. in questo e nei successivi paragrafi verranno utilizzate, nella descrizione degli elementi morfologici dei terrazzi, alcune sigle (poste tra parentesi) che si riferiscono alla fig. 31, descritta al paragr. 3.1. 2.2.1. primo settore (tra il f. trionto ed il fosso petraro-vallone pomo) a) aspetti geometrici (fig. 6 a) il corpo sedimentario terrazzato ha una ampiezza (si.g.) massima trasversale alla costa di 1000 m; lo spessore massimo è di 45 m, in corrispondenza della copertura continentale meglio conservata. la superficie inferiore del terrazzo si alza in quota da circa 51 fino a 60 m con andamento regolare e rettilineo (si.tr.) e con inclinazione calcolata di 0,8°, per poi incurvarsi verso l’alto (si.tc.) e chiudersi a quasi 120 metri s.l.m. (questo tratto ha una inclinazione media calcolata di 7,3°). la superficie superiore del terrazzo (intesa come ss.r.) varia da 92 a 110 m. occorre ovviamente notare che la parte “esterna” del terrazzo è mancante in quanto erosa dalla genesi del terrazzo successivo, sviluppato tra 60 e 70 m di quota (paragr. 2.3.1.). l’originario terrazzo si presenta oggi fortemente rimodellato e intagliato anche dallo sviluppo del reticolo idrografico conseguente al sollevamento dell’area; i lembi terrazzati meglio conservati corrispondono ai rilievi a 105 e a 114 m (vedi fig. 38) denominati: serricelle di mirto e destra dei biviere. il profilo a di fig. 6 deriva dalla proiezione su un piano n-s del crinale che si sviluppa dal paese di crosia (a sud) fino alla stazione di mirto crosia (a nord). i dati geologici e stratigrafici che hanno permesso la ricostruzione della sezione geologica appartengono invece a tutta l’area compresa tra il f. trionto (ad ovest) ed il fosso petraro-vallone del pomo (ad est). essi sono stati utilizzati proiettandoli sulla sezione n-s secondo direttrici facenti un angolo con il nord di 122°; tale angolo corrisponde alla direzione di sviluppo lungo costa del terrazzo stesso e, in particolare, alla direzione della congiungente i margini interni delle superfici terrazzate (vedi cap. 3.12.). questo metodo è stato utilizzato anche per le altre ricostruzioni che verranno descritte più avanti; l’integrazione di tutti i dati consente di riconoscere le reali variazioni che avvengono all’interno del corpo terrazzato. un inconveniente è risultato il maggior sollevamento (circa 10 m) riscontrato a se nel terrazzo, causato da faglie circa ne-so (40-42°) e no-se (122-123°), già individuate mediante lo studio morfotettonico dell’area e confermate dall’analisi dei rigetti stratigrafici presenti nel substrato. b) aspetti litologici e sedimentologici il deposito terrazzato si presenta complesso, con 49genesi, età, sollevamento ed erosione ... fig. 5 settore 1°: blocco isolato di calcari algali, alla quota di circa 50 m, franato lungo il versante argilloso sottostante al crinale di quota 155-131 m. esso proviene quindi dal terrazzo del i ordine, così come i blocchi di calcare algale, rielaborati dalle onde, presenti a volte nei depositi marini dei terrazzi più bassi. sector 1: isolated block of algal limestone, at an altitude of about 50 m, along a clayey slope under the ridge at an altitude of 155-131 m (fig. 1). this block testifies to the terraced deposit of the 1st order; there are also blocks of algal limestone, reworked by the waves, in the marine deposits of the lower terraces. 50 l. carobene f ig . 6 p ro fil o de l c rin al e co m pr es o tr a la c ul m in az io ne d i q uo ta 1 31 m e l’ ab ita to d i s ta zi on e di m irt o c ro si a (f ig . 1 ); c os tit ui sc e la p ro se cu zi on e di q ue llo r ip or ta to in f ig . 2 . aa ) s ez io ne g eo lo gi ca d el ttee rrrr aazz zzoo dd eell iiii oo rrdd iinn ee re la tiv o al s et to re 1 . i l d ep os ito è s ud di vi si bi le n el le li to fa ci es m ar in e c b, p m , s i, a gs , p ds e d s s (p er la d es cr iz io ne v ed i p ar ag r. 2 .2 .1 .b .) ; i l r el itto d el la s up er fic ie t er ra zz at a di q . 10 5 m c on se rv a an ch e la li to fa ci es c on tin en ta le c c. l a se zi on e m os tr a i c ar at te ri ge om et ric i e s ed im en ta ri de l d ep os ito t er ra zz at o; e ss i v en go no d is cu ss i a l c ap . 3 , p ar ag ra fi 1, 4 e 5 . l a co rr is po nd en te p al eo lin ea d i r iv a (p lr .) s i c ol lo ca a 1 05 m c irc a su l l .m . l a pa rt e se tte nt rio na le r iv ol ta v er so m ar e ris ul ta tr on ca ta d al la fo rm az io ne d el ttee rrrr aazz zzoo dd eell iiiiii oo rrdd iinn ee,, ra pp re se nt at o ne l p ro fil o bb ) co n pa le ol in ea d i r iv a a 65 m . la g eo m et ria in te rn a de l d ep os ito è s im ile a q ue lla d el te rr az zo d el ii o rd in e, m a al cu ne li to fa ci es s on o m en o ra pp re se nt ate . n ot a: p er i si m bo li m or fo lo gi ci v ed i f ig . 3 1. il r ig et to d el le li ne e te tto ni ch e a 12 2° e a 1 23 ° no n è ch ia ro , m a è ev id en te il lo ro e ffe tto m or fo lo gi co , d at o da s el le e in ci si on i t ra sv er sa li. p ro fil e of th e rid ge ly in g be tw ee n th e cu lm in at io n at 1 31 m a nd th e to w n of “ s ta zi on e di m irt o c ro si a” ( f ig . 1 ); th is is th e co nt in ua tio n of th at r ep or te d in f ig . 2 . a ) g eo lo gi ca l s ec tio n of th e ttee rrrr aacc ee ooff tthh ee 22nndd oorr ddee rr in s ec to r 1. t he d ep os it is s ub di vi da bl e in to th e m ar in e lit ho fa ci es c b, p m , s i, a gs , p ds a nd s s (f ig . 3 3; d es cr ip tio n in p ar ag ra ph 2 .2 .1 .b .) ; th e re m ai ns o f th e te rr ac ed s ur fa ce a t a he ig ht o f 10 5 m a ls o pr es er ve c c co nt in en ta l l ith of ac ie s. t he s ec tio n sh ow s th e ge om et ric a nd s ed im en ta ry c ha ra ct er is tic s of t he t er ra ce d de po si t; th es e ar e di sc us se d in c ha pt . 3, p ar ag r. 1 , 4 an d 5. t he c or re sp on di ng p al eo sh or el in e (p lr .g ) ca n be p la ce d at a h ei gh t of a bo ut 1 05 m . t he n or th er n se ct or , fa ci ng t ow ar ds t he s ea , ha s be en tr un ca te d by th e fo rm at io n of th e tee rrrr aacc ee ooff tthh ee 33rrdd oorr ddee rr , r ep re se nt ed in p ro fil e b ) as a p al eo sh or el in e at a h ei gh t o f 6 5 m . t he in te rn al g eo m et ry o f t he d ep os it is s im ila r to th at o f t he te rra ce o f t he 2 nd or de r, b ut s om e lit ho fa ci es a re le ss r ep re se nt ed . n b : s ee f ig . 3 1 fo r th e m or ph ol og ic al s ym bo ls . t he th ro w o f t he te ct on ic li ne s at 1 22 ° an d 12 3° is n ot c le ar , w hi le th ei r m or ph olo gi ca l e ffe ct is . 51genesi, età, sollevamento ed erosione ... fig. 7 terrazzo del ii ordine; settore 1°; quota 58 m; passaggio tra le argille del substrato e le “sabbie inferiori” (litofacies si). sulla superficie di erosione argillosa poggiano direttamente ciottoli ben arrotondati di 15-25 cm di diametro (litofacies cb); essi sono la testimonianza del fenomeno del riciclaggio dei conglomerati appartenenti al terrazzo superiore (vedi 3.8.); l’embriciatura è verso mare (a sinistra). (disegno tratto da fotografia) terrace of 2nd order; sector 1; altitude 58 m; change from the pleistocene clays of the substratum to the “lower sands” (si lithofacies). well rounded pebbles of 15-25 cm diameter lie directly on the erosion surface; these testify to the phenomenon of recycling of conglomerates belonging to the older terraces (see chapt. 3.8.); the imbrication is towards the sea (left). design based on photograph. fig. 8 terrazzo del ii ordine; settore 1°; litofacies si. affioramento di quota 92 m (vedi fig. 6a) costituito da sabbie a stratificazione parallela; gli strati sono inclinati di pochi gradi verso nord. nella parte alta affiora un deposito ciottoloso pedogenizzato (forse riferibile alla litofacies ags). terrace of 2nd order; sector 1; si lithofacies. outcrop of parallel-stratified sands at an altitude of 92 m (fig. 6a); the layers are inclined a few degrees towards the n. a pedogenised pebbly deposit crops out in the upper part (perhaps relatable to the ags lithofacies). fig. 9 terrazzo del ii ordine; settore 1°; quota 60-70 m; litofacies si: alternanze di sabbie fini grigio-chiaro e di sabbie grosse color grigio scuro, con ciottoletti. nelle sabbie scure sono evidenti strutture da ripples; gli strati inclinano di 1-3° verso mare. facies: spiaggia sottomarina esterna alle barre (shoreface inferiore). terrace of 2nd order; sector 1; altitude 60-70 m; si lithofacies: alternate layers of light grey-coloured fine sands and dark greycoloured coarse sands, with pebbles. there are ripples in the dark sands; the layers incline 1-3° towards the sea. facies: underwater beach outside the bars (lower shoreface). vistose variazioni di facies causate da un processo trasgressivo e da una fase finale di alto stazionamento del mare alla quota di 105-110 metri; un deposito regressivo legato all’abbassamento eustatico non è stato riconosciuto. i corpi con differente litologia verranno per semplicità descritti separatamente, pur essendo tra loro geneticamente legati. 1) conglomerato basale (cb). la superficie inferiore del terrazzo taglia in discordanza le argille pleistoceniche del substrato, inclinate di 13-15° verso mare. sulla superficie poggiano direttamente ciottoli ben arrotondati con diametro fino a 20-25 cm, spesso distribuiti su un unico orizzonte (fig. 7); in altre situazioni sono presenti strati di ghiaie ben cementate. 2) peliti marine (pm). comprendono alternanze sottili di peliti sabbiose e di sabbie fini siltose con livelletti pelitici, in parte bioturbate, immergenti verso nord di 2-3°. definiscono un ambiente di spiaggia profonda che risentiva delle forti mareggiate. 3) sabbie grigie inferiori (si). questa litofacies è caratterizzata da sabbie grigie da fini a grosse, con superfici di stratificazione immergenti di 4-6° verso ne (direzione media degli strati: 120°) (fig. 8). la stratificazione definisce pertanto un ambiente marino che si approfondisce verso nord. la maggior batimetria è documentata da sabbie, a volte bioturbate, medio-fini, fini e da livelletti siltosi; la batimetria minore da sabbie grosse e molto grosse con sottili orizzonti a piccoli ciottoli, e inoltre da strutture erosive che producono continue variazioni granulometriche (fig. 9), caratteristiche di un ambiente di spiaggia sottomarina dominato dalle onde e dalla migrazione delle barre. 4) alternanze ghiaioso-sabbiose (ags). sono costituite da sabbie molto grosse, ghiaietto millimetrico o da ghiaie centimetriche in alternanze spesso lentiformi; i clasti appiattiti risultano immergenti a ne, con evidente embriciatura dei ciottoli verso mare (fig. 10); anche la stratificazione è caratterizzata da immersioni verso ne, con inclinazioni di 2-4°. questi dati testimoniano l’origine marina del deposito, rappresentativo della battigia o della spiaggia sottomarina superiore (fig. 11). 52 l. carobene fig. 10 terrazzo del ii ordine; settore 1°; quota 80 m; località: fosso tra destra dei biviere e destra della garruba; litofacies ags: alternanze di sabbie e ghiaie. gli strati sono evidenziati da superfici erosive cuneiformi se; i sets (s) all’interno sono discordanti con le superfici di strato; i ciottoli sono embriciati a destra (verso mare). facies di battigia. in alto: a= livello argilloso ricco di carbonato di calcio (pds?); d= detrito di versante pedogenizzato. terrace of 2nd order; sector 1; altitude 80 m; locality: small valley between destra dei biviere and desta della garruba; ags lithofacies: alternate sandy and clayey layers. the beds have wedge-shaped erosive surfaces towards the se; the internal sets (s) are discordant with the surfaces of the beds; the pebbles are imbricated towards the nnw (towards the sea). foreshore facies. at the top: a = carbonate-rich clayey layer (pds?); d = pedogenised slope detritus. fig. 11 terrazzo del ii ordine; settore 1; quota 95 m; località: destra dei biviere; litofacies ags: alternanze ghiaioso-sabbiose e sabbioso-ghiaiose. embriciatura dei ciottoli verso ne; superfici di strato mal definite, inclinate di 4-8° verso ne. il deposito passa in alto a sabbie (fig. 12). terrace of 2nd order; sector 1; altitude 95 m; locality: destra dei biviere; ags lithofacies: alternate gravely-sandy and sandygravely layers. pebbles imbricated towards the ne; poorly defined bed surfaces, dipping 4-8° towards the ne. the deposit becomes sandy towards the top (fig. 12). 53genesi, età, sollevamento ed erosione ... fig. 12 terrazzo del ii ordine; settore 1°; quota 90-100 m; litofacies ags in basso e ss in alto. la parete è rivolta a se; le “alternanze ghiaioso-sabbiose” ags sono fotografate in fig.11 e le “sabbie superiori” ss in fig. 13. terrace of 2nd order; sector 1; altitude 90-100 m; ags lithofacies at the bottom and ss at the top. the wall is turned towards the se; the “alternate gravelly-sandy layers” of ags are visible in fig. 11 and the ss “upper sands” in fig. 13. 5) peliti dulcicole-salmastre (pds). occupano un bacino di retrospiaggia esteso da terra verso mare per circa 600 m e potente, nella sua parte più profonda, fino a 25 m. la sequenza pelitica è stata riconosciuta bene alla base (circa alla quota di 75 m), e nella sua parte più alta (circa alla quota di 100 m), fornendo campioni con microfaune da dolci a salmastre; litologicamente è rappresentata da silt e argille grigie, da silt sabbiosi e da sabbie pelitiche. il nucleo centrale dell’unità è stato mal riconosciuto; tuttavia l’intera successione è stata ben descritta e campionata nel contiguo settore 2. l’andamento della base del deposito definisce un corpo di forma convessa, delimitato a nord direttamente dall’unità ghiaioso-sabbiosa (ags). 6) sabbie gialle superiori (ss). compaiono al di sopra del deposito pelitico (pds) o dell’unità ghiaiososabbiosa (ags) (fig.12) con spessori di 1-5 m (fig. 13). le sabbie presentano colore giallo o giallo-bruno per leggera pedogenesi (10yr-5/4); mostrano una blanda stratificazione dovuta a variazioni granulometriche, da sabbie medio-fini a grosse; l’immersione è verso ne con inclinazione di 4-5°. le osservazioni discontinue effettuate su questa unità non hanno permesso una precisa ricostruzione della sua estensione areale e degli spessori; in base alle strutture e tessiture rilevate è possibile ritenere che il deposito sia marino, forse di spiaggia emersa. 7) conglomerati continentali (cc). i vari lembi relitti del corpo terrazzato sopra descritto sono ricoperti da un deposito ruditico pedogenizzato (colore 5yr-4/6) il cui spessore varia da 3-5 m nei rilievi più bassi ad ovest (105 m s.l.m.) fino a 8-10 m nei rilievi più alti (112-114 m) ad est. sono depositi mal classati, eterometrici, con grossolana struttura a lenti, a giacitura suborizzontale, di origine alluvionale. c) considerazioni ambientali la litologia dei depositi sopra descritti, le strutture fig. 13 terrazzo del ii ordine; settore 1°; quota 100 m; località destra dei biviere; litofacies ss: sabbie fini giallastre. le sabbie si presentano con strati mal definiti, inclinati di 4-5° verso ne; nella parte alta sono poco classate e pedogenizzate. si sviluppano per almeno 4 m al di sopra delle alternanze ags di fig. 11. terrace of 2nd order; sector 1; altitude 100 m; locality: destra dei biviere; ss lithofacies: fine yellowish coloured sands. the sands here have poorly defined layers dipping 4-5° towards the ne. they develop for at least 4 m above the ags alternations (fig. 11). sedimentarie osservate, la disposizione nello spazio delle varie unità che costituiscono il corpo sedimentario terrazzato e le indicazioni desunte dalle faune fossili rinvenute permettono di considerare le varie litofacies rappresentate in fig. 6 come il risultato di una trasgressione marina che ha tagliato il substrato argilloso depositando sulla superficie inferiore del terrazzo ciottoli ben arrotondati e ghiaie (unità cb); la formazione a quote via via crescenti di cordoni sabbioso-ghiaiosi emersi (unità ags) ha determinato una eteropia di facies da riva verso il largo, rappresentata nell’ordine dalle unità ags, si e pm. successivamente la fase di alto stazionamento del mare ha causato, in presenza di abbondanti apporti detritici, la migrazione verso mare della battigia e della spiaggia emersa (unità ags) e la conseguente formazione di un ampio bacino di retrospiaggia dulcicolo-salmastro o lagunare (unità pds) costituito essenzialmente da peliti argillose e sabbiose. la successione sopra citata si chiude con alcuni metri di sabbie che possono rappresentare sia una migrazione verso terra (trasgressione) della spiaggia, sia la fase regressiva causata dall’abbassamento eustatico. segue la fase continentale, con alluvioni ciottoloso-sabbiose derivanti dalla estensione laterale della piana fluviale del paleo-trionto; esse ricoprono il corpo terrazzato marino con spessori fino a 10 metri. in base alla quota massima dei sedimenti marini riconosciuti, la paleolinea di riva più alta si colloca a 105 m di quota. 2.2.2. secondo settore (località cozzo del finocchio – fulitano) in questo settore il terrazzo del ii ordine è rappresentato da lembi di corpi terrazzati che formano culminazioni topografiche; esse sono disposte lungo due crinali disposti ne-so alle quote di 113 e 124 m (cozzo del finocchio) e di 112 e 131 m (fulitano) (fig. 1 e fig. 38). per quanto manchino vere e proprie superfici terrazzate, è possibile riconoscere (su base topografica) che la superficie superiore del terrazzo (ss.r.) è estesa tra 100 e 131 m di altezza; essa corrisponde a quella descritta tra 90 e 110 m nel 1° settore (paragr. 2.2.1.). pertanto, come emerge anche dalla dislocazione dei depositi, le superfici terrazzate del ii ordine risultano più sollevate di circa 10 m rispetto al 1° settore, a causa di faglie disposte circa ne-so (40°-41°), mentre il lembo a 131 m (fig. 14) risulta più alto di 15-20 m (sempre rispetto al 1° settore) per una faglia di direzione circa no-se (123°). anche in questo paragrafo, così come nei successivi, le sigle poste tra parentesi si riferiscono alla fig. 31. a) aspetti geometrici (fig. 14) i rilievi sopra ricordati individuano un corpo terrazzato avente un’ampiezza ne-so trasversale alla costa (si.g.) non superiore a 800 m; esso pertanto risulta meno largo di circa 200 m rispetto a quello corrispondente descritto nel 1° settore. lo spessore massimo del corpo terrazzato (compresi i depositi continentali di chiusura) è di 46 m. la superficie inferiore del terrazzo, troncata verso mare dalla formazione del terrazzo più basso, appare dislocata (nella parte a monte) di 10 m da una faglia no-se (123°): il tratto rettilineo (si.tr.) si alza da quota 64 a 67 m con una inclinazione calcolata di 0,5°; il tratto a monte (si.tc.) si incurva chiudendosi a quota 110 m (con inclinazione media di 6,3°). con un procedimento analogo a quello già utilizzato nel 1° settore, tutti i punti di osservazione dell’area in esame sono stati proiettati sul piano verticale ne-so (48°) della sezione (fig. 14) secondo direttrici con direzione no-se (circa 125°), che corrisponde alla direzione della retta congiungente i margini interni, ovvero allo sviluppo lungo costa del terrazzo. b) aspetti litologici e sedimentologici il corpo terrazzato in esame presenta unità litologiche e variazioni di facies simili a quelle già descritte nel settore 1; l’analisi di questo settore ha tuttavia permesso ulteriori precisazioni che hanno fornito nuovi elementi di comprensione. sulla superficie inferiore del terrazzo poggia un sottile orizzonte di ciottoli decimetrici ben arrotondati, spesso sfericizzati (conglomerato basale trasgressivo cb). su di esso si sviluppa un cuneo sabbioso il cui spessore aumenta progressivamente verso mare fino a 10-12 metri: si tratta di sabbie grigie (unità si) da fini in basso a grosse in alto, a volte cementate, a volte sciolte. gli strati sono inclinati di 5-6° verso n o ne. considerando quanto osservato nel 1° settore, si può concludere che le sabbie si sono deposte in una spiaggia sommersa a differenti batimetrie; ciò spiega sia le differenze granulometriche, sia le varie strutture osservate: le sabbie fini sono caratterizzate da laminazione piano-parallela con livelli siltosi; le sabbie grosse da stratificazione incrociata concava. ben documentata risulta la sovrastante unità ghiaioso-sabbiosa (ags) che assume spessori via via crescenti verso mare, fino ad un massimo di 15 m. assieme all’unità delle sabbie inferiori costituisce la base grossolana del corpo terrazzato, poggiante sul substrato argilloso. ciò crea un netto aumento di pendenza lungo i versanti vallivi, con inclinazioni medie di 12° in corrispondenza delle argille del substrato e con valori prevalenti di 25° o superiori in corrispondenza delle sabbie e delle ghiaie del corpo terrazzato (fig. 15). in località fulitano (fig. 14, quota 75 m), l’unità ags presenta alternanze di sabbia grossolana ben classata ricca di ghiaietto con abbondanti clasti appiattiti (con diametri prevalenti di 3 cm) e livelli ciottoloso-sabbiosi (con diametri fino a 20 cm); i clasti appiattiti mostrano embriciatura verso nord; gli strati inclinano di 6-8°. struttura e tessitura indicano spiaggia alta, probabilmente battigia. la migrazione della spiaggia verso il largo ed il suo innalzamento in quota hanno creato un bacino riparato (lagunare, salmastro, dulcicolo) con ampiezza massima documentabile di 700 m. al suo interno si è deposta l’unità pelitica dulcicola-salmastra (pds), ben documentata da fitte campionature, avente uno spessore massimo di 24 m. rispetto al settore 1 l’unità è più argillosa; in detta successione la sequenza pelitica si sviluppa con alternanze di materiale più fine e più grosso, costituito da argille, argille con veli sabbiosi, silt argillosi, sabbie fini con lamine argillose e infine sabbie, a volte grosse e con sottili livelli di ciottoletti. nella parte alta compaiono orizzonti o lenti di sabbie, da fini a grossolane, a volte con livelli ciottolosi indicativi di ambiente di spiaggia intertidale o battigia (fig. 54 l. carobene 55genesi, età, sollevamento ed erosione ... f ig . 1 4 p ro fil o de l c rin al e (f ig . 1 e tr ac ci a b -b ’ i n f ig . 3 8) , r el at iv o al 2 ° s et to re ( pa ra gr . 2 .2 .2 .) . i d at i t op og ra fic i e g eo lo gi ci s on o st at i p ro ie tta ti su l p ia no v er tic al e de lla s ez io ne o rie nt at a ci rc a n e -s o ( 48 °) . aa ) tt eerr rraa zzzz oo ddee ll ii ii oo rrdd iinn ee ; e ss o ris ul ta a m pi am en te tr on ca to v er so m ar e da lla fo rm az io ne d el te rr az zo s uc ce ss iv o, m en tr e la p ar te a m on te ( a s o ) ris ul ta s ol le va ta d al la fa gl ia c on d ire zi on e 12 3° (f ig . 3 8) . l a pa le ol in ea d i r iv a (p lr .g .) è c ol lo ca bi le a 1 20 m c irc a (s ta ge 7e – v ed i c ap . 3 .2 .) . bb ) tt eerr rraa zzzz oo ddee ll ii iiii oorr ddii nnee , c on p al eo lin ea d i r iv a a 70 m c irc a (s ta ge 5e – v ed i c ap . 3 .2 .) . l ’a ss en za d el le p el iti m ar in e (li to fa ci es p m ) in di ca c he a nc he q ue st o te rr az zo è p riv o de lla p ar te e st er na , p ro ba bi lm en te a sp or ta ta d ai li ve lli m ar in i p iù b as si . n ot a: i si m bo li de lle li to fa ci es s on o sp ie ga ti, r is pe tti va m en te , a i p ar ag r. 2 .2 .2 .b . e 2 .3 .2 .b . p er i si m bo li m or fo lo gi ci v ed as i f ig . 3 1. p ro fil e of th e rid ge ( lin e b -b ’ i n f ig . 3 8) in s ec to r 2 (f ig . 1 ). aa ) tt eerr rraa ccee oo ff tt hhee 22 nndd oorr ddee rr ; th is is c le ar ly tr un ca te d to w ar ds th e se a by th e fo rm at io n of th e su cc es si ve te rr ac e, w hi le th e up hi ll pa rt ( to th e s w ) is u pl ift ed b y a fa ul t w ith d ire ct io n 12 3° ( f ig . 3 8) . t he p al eo sh or el in e (p lr .g .) c an b e pl ac ed a t a h ei gh t o f a bo ut 1 20 m ( st ag e 7e – p ar ag r. 3 .2 .) . bb ) tt eerr rraa ccee oo ff tthh ee 33 rrdd oorr ddee rr , w ith a p al eo co as tli ne ( p lr .g .) a t a he ig ht o f ab ou t 70 m ( st ag e 5e – p ar ag r. 3 .2 .) . t he a bs en ce o f m ar in e pe lit es ( p m li th of ac ie s) in di ca te s th at t hi s te rr ac e is a ls o la ck in g its e xt er na l p ar t, pr ob ab ly c ar rie d aw ay b y lo w er m ar in e le ve ls . n b : s ee f ig . 3 3 fo r th e sy m bo ls o f t he li th of ac ie s. s ee f ig . 3 1 fo r th e m or ph ol og ic al s ym bo ls . 16). essi si alternano alle argille (fig. 17 e 18) e testimoniano il ripetersi di variazioni ambientali (cap. 3.6.). localmente (loc. fulitano) le peliti (pds) sono ricoperte per 5 m da un deposito sabbioso-ghiaioso, con superfici erosive e laminazione incrociata, indicativo di un ambiente di alta energia e pedogenizzato in alto per 7-8 m. depositi conglomeratici eterometrici, sabbie e peliti di ambiente alluvionale (unità cc) chiudono la successione marina, per uno spessore di circa 5-7 metri (fig. 19). il deposito continentale si presenta pedogenizzato, con colori munsell variabili da 5 yr-3/4 a 2,5 yr-3/44/6. c) considerazioni ambientali sono confermate quelle espresse per il terrazzo del settore 1. in base alla quota massima dei sedimenti marini riconosciuti, la paleolinea di riva si colloca a 120 m s.l.m. nel lato so del terrazzo, rialzato rispetto al lato ne (verso mare) da una faglia (n123°) con rigetto di circa 10 m. 2.2.3. terzo settore (in destra del t. fiumarella) il terrazzo del ii ordine è rappresentato, nella parte occidentale dell’area studiata, da 5 lembi di depositi terrazzati costituenti altrettanti rilievi isolati con quote massime di 96, 92, 87, 92 e 96 metri da no a se (figg. 1 e 38). una sella più o meno accentuata separa ognuno di questi rilievi dall’area a so che sale verso il paese di calopezzati (217 m s.l.m.): le selle sono perfettamente allineate tra loro in direzione 142°. tutta l’area a se del t. fiumarella (per una estensione di almeno 25 km) presenta lineamenti in tale direzione, circa no-se. essi sono deducibili dal pattern del drenaggio, da allineamenti di selle e scarpate, da crinali rettilinei; alcuni di questi corrispondono, nell’area esaminata, a faglie che dislocano il substrato pleistocenico, con rigetti di 10-20 metri. la direttrice tettonica (allineata lungo le selle) ha condizionato la genesi e l’evoluzione di questo terrazzo, il cui corpo sedimentario è osservabile solamente a ne della faglia stessa. il settore in destra del t. fiumarella 56 l. carobene fig. 15 terrazzo del ii ordine; settore 2°. l’immagine mostra l’evidenza morfologica del deposito terrazzato poggiante sulle argille (a) del substrato. la scarpata coperta da vegetazione si sviluppa tra 65 e 90 m circa; essa corrisponde alle litofacies ags e si. sulla destra masseria dei forni (quota 61 m). terrace of 2nd order; sector 2. the photo provides morphological evidence of the terraced deposit lying on the clays (a) of the substratum. the escarpment, covered in vegetation, develops between about 65 and 90 m; this corresponds to the ags and si lithofacies. to the right masseria dei forni (altitude 61 m). fig. 16 terrazzo del ii ordine; settore 2°; quota 95-98 m; località cozzo del finocchio; orizzonte sabbioso-ghiaioso entro le peliti di retrobarriera (litofacies pds); spessore totale circa 3 m. matrice pelitica assente e ghiaia a clasti appiattiti; ciottoli embriciati verso mare. facies di battigia (foreshore parte alta). potrebbe corrispondere alle intercalazioni 4 o 5 di fig. 22. terrace of 2nd order; sector 2; altitude 95-98 m; locality: cozzo del finocchio; pds lithofacies: sandy-gravely layer, which has a total thickness of about 3 m, within the back-barrier pelites). flattened clastic gravel without a pelitic matrix; imbricated pebbles towards the sea. upper foreshore facies. this could correspond to intercalations 4 or 5 of fig. 22. è interessato anche da due famiglie di lineamenti principali con direzioni medie di 38° (neso) e di 26° (nne-sso), con effetti tettonici di modesta entità, per quanto riguarda i l pleistocene medio e superiore. un’altra particolarità emersa dallo studio di questo settore è legata alla progressiva diminuzione degli apporti detritici del fiume trionto da no verso se, diminuzione alla quale si può far corrispondere una erosione costiera crescente nella stessa direzione: infatti la fascia costiera olocenica, che ha un’ampiezza di oltre 1 km a n della stazione di mirto crosia (km 322 della s.s. 106), si riduce a meno di 200 m a se (km 316) (fig. 1). questa caratteristica dinamica della costa deve essersi manifestata anche nel passato, tanto che il terrazzo del iii ordine (linea di riva a 65÷70 m) ha in destra trionto un’ampiezza di 600 m, mentre in destra fiumarella riduce la sua ampiezza a 200 m, fino quasi a sparire a se. il minor apporto detritico fluviale nella fascia costiera doveva essere minore nel passato così come lo è oggi: infatti nessuno dei 5 relitti del terrazzo, presenti nel 3° settore in esame mostra la tipica copertura continentale alluvionale che invece, in destra trionto, caratterizzava le superfici terrazzate con spessori di 5-10 m! a) aspetti geometrici (fig. 20-a) i 5 relitti terrazzati, testimonianza dell’originario terrazzo, hanno una ampiezza trasversale alla costa che varia da 800 m (a no) ad un minimo di 350 m (a se). nel calcolo di questi valori si è tenuto conto che lo sviluppo dei terrazzi perpendicolarmente alla costa è circa in direzione eneoso (65°), mentre il profilo di fig. 20-a è stato ottenuto proiettando i dati altimetrici del crinale più settentrionale del settore su un piano verticale con direzione 27° (d-d’ in fig. 38); per questa ragione le lunghezze presenti in figura sono apparenti (cioè maggiori di quelle reali). lo spessore massimo del corpo terrazzato risulta di 28 m, inferiore quindi di circa 17 m rispetto a quello misurato nel 1° e 2° settore. ciò 57genesi, età, sollevamento ed erosione ... fig. 17 terrazzo del ii ordine; settore 2°; quota 98 m; località cozzo del finocchio; litofacies: passaggio tra sabbie (parte alta dell’orizzonte di fig. 16) e la litofacies pds visibile in fig. 18. le sabbie sono grossolane e ben classate. terrace of 2nd order; sector 2; altitude 98 m; locality: cozzo del finocchio; lithofacies: change in sands (upper part of layer in fig. 16) and pds clays visible in fig. 18. the sands are coarsegrained and well-sorted. fig. 18 terrazzo del ii ordine; settore 2°; quota 100 m; località cozzo del finocchio; litofacies: intercalazione ciottoloso-sabbiosa marina entro le peliti argillose pds. i ciottoli sono arrotondati e ben cementati alla base; lo spessore totale è di circa 2,5 m; in alto sono presenti rade ostreidi; la successione prosegue con peliti pds. questo orizzonte ciottoloso può corrispondere all’intercalazione 6 di fig. 22. terrace of 2nd order; sector 2; altitude 100 m; locality: cozzo del finocchio; lithofacies: pebbly-sandy marine layers between pds clayey pelites. the pebbles are rounded and well-cemented at the base; the total thickness is about 2.5 m; ostreidi roadsteads are present in the upper part; the succession continues with pds pelites. this pebbly layer could correspond to intercalation 6 in fig. 22. è spiegabile in base all’assenza del materasso alluvionale di chiusura che (come detto sopra) raggiunge invece i 5-10 m di spessore nei settori in sinistra fiumarella; l’esiguità o l’assenza del deposito ruditico alluvionale ha favorito il processo erosivo del corpo sedimentario marino che infatti, per confronto, risulta eroso per circa 10 m. la superficie inferiore del terrazzo appare troncata in corrispondenza del lineamento con direzione 142°; il tratto rettilineo, che è esteso tra le quote di 65 e di 70 m, ha una inclinazione reale (calcolata) verso mare di 0,4°; il tratto curvo a monte (si.tc.) è mancante. il profilo riportato in fig. 20-a è riferito al lembo terrazzato settentrionale (fig. 1); su di esso sono state tuttavia riportate tutte le osservazioni geologiche osservate anche nei 4 lembi a se, secondo direttrici a 142° n (direzione dello sviluppo lungo costa del terrazzo), al fine di una integrazione di tutti i dati di campagna. b) aspetti litologici e sedimentologici risulta ben documentato il conglomerato basale (cb), costituito da ciottoli molto arrotondati, in maggioranza ellissoidici o sfericizzati ma anche appiattiti, con diametri prevalenti di 10-20 cm, fino a 40 cm, poligenici (arenarie mioceniche, graniti, quarzo e scarse rocce metamorfiche). la matrice è scarsa, costituita da sabbia grossolana e ghiaietto fine; la cementazione è variabile, a volte assente; la struttura è spesso caratterizzata da bande lentiformi allungate di ciottoli a diversa granulometria, con clasti appiattiti immergenti a ene con inclinazioni da 10 a 45°: essa testimonia un ambiente di battigia (fig. 21). localmente sulle argille del substrato poggiano direttamente arenarie grossolane con ghiaietto, in strati ben cementati e con spessori inferiori al metro; lo spessore complessivo di questa unità è di 1-3 metri. nella parte esterna del terrazzo ai conglomerati fanno seguito sabbie (si), da medie a grosse, sciolte, con buona classazione, a volte con livelli di piccoli ciottoli; localmente sono presenti alla base delle sabbie grossi gusci di ostreidi. questa unità non risulta ben rappresentata ed è probabilmente assente a so. ad esse si sovrappone l’unità ghiaioso-sabbiosa (ags) costituita in prevalenza da un’alternanza di arenarie grossolane con ghiaie stratificate a scarsa matrice, entrambe ben classate; i ciottoli hanno diametri variabili, fino a 20-30 cm; i clasti sono spesso appiattiti con embriciatura verso e o verso ne; gli strati, inclinati di 57° verso mare, sono a volte cementati in vicinanza della base del corpo terrazzato. negli affioramenti osservati l’unità è rappresentativa di un ambiente ad alta energia (spiaggia sottomarina alta o battigia); essa non risulta ben documentata nella parte verso mare del terrazzo per difficoltà di osservazione, mentre sembra assottigliarsi verso terra, cioè verso so. l’unità pelitico-sabbiosa (pds) è ben documentabile nella parte interna del corpo terrazzato: è costituita da peliti argillose (p.a.), siltose (p.s.) e sabbiose (p.sb.) e da sabbie fini pelitiche (s.p.) grigie e giallo-grigie, intercalate da livelli conglomeratici in giacitura suborizzontale. la colonna stratigrafica (fig. 22) correla situazioni riscontrate nei vari lembi terrazzati: non è pertanto riconoscibile in ogni singolo lembo. la figura illustra inoltre la stratigrafia della parte centrale del terrazzo, dove è massimo lo spessore dell’unità pelitica (pds); le situazioni cambiano per eteropia di facies verso terra e, soprattutto, verso mare. (fig. 20-a). gli orizzonti conglomeratici 1 e 2 hanno spessori di 20-40 cm, e sono costituiti da ciottoli poligenici, eterometrici (diametro massimo minore di 20 cm); i clasti appiattiti sono embriciati verso ovest, e ciò testimonierebbe l’origine fluviale dei due orizzonti. (fig. 23). le intercalazioni 3 e 4 sono invece di origine marina, in base alla presenza di frammenti di lamellibranchi e di gusci di ostreidi al tetto; inoltre i ciottoli appiattiti sono embriciati verso mare. incerta la natura del sottile orizzonte 5; sicuramente marini i grossi orizzonti 6 e 7 (spessori compresi tra 50 e 100 cm), costituiti da strati cementati di arenaria grossa, ricca in ciottoli, da biocalcareniti fossilifere, da banchi conglomeratici in matrice sabbiosa a ciottoli decimetrici; il n.6 presenta ostreidi al tetto. occorre inoltre ricordare che lo spessore massimo del corpo terrazzato (in corrispondenza del top dell’unità pelitica) è risultato di circa 37 m nei settori 1 e 2, mentre nel settore 3 (fig. 20-a) esso non supera i 28 m: anche considerando che esistono sicuramente errori di misura, 58 l. carobene fig. 19 terrazzo del ii ordine; settore 2°; quota 105 m; località cozzo del finocchio; litofacies cc: deposito ruditico pedogenizzato a ciottoli in prevalenza arrotondati, in abbondante matrice sabbioso-limosa. colore munsell: 2,5 yr – 3/6. e’ visibile un’alternanza tra livelli a ciottoli più fini e più grossi; i ciottoli appiattiti sono embriciati verso monte (a destra). terrace of 2nd order; sector 2; altitude 105 m; locality: cozzo del finocchio; cc lithofacies: pedogenised ruditic deposit, with prevalently rounded pebbles, in an abundant muddy-sandy matrix. munsell colour: 2.5 yr – 3/6. an alternation of smaller and larger pebbles is visible; the flattened pebbles are imbricted landward. 59genesi, età, sollevamento ed erosione ... f ig . 2 0 p ro fil o pa rz ia le d el c rin al e ch e da c al op ez za ti sc en de v er so m ar e, n el 3 ° s et to re , i n de st ra d el t . f iu m ar el la ( tr ac ci a d -d ’ i n f ig . 3 8) ; i d at i t op og ra fic i s on o pr oi et ta ti su u n pi an o ve rt ica le a ve nt e di re zi on e n 27 °e . aa ) la s ez io ne g eo lo gi ca ti en e co nt o de lle o ss er va zi on i e ffe ttu at e in tu tti i 5 re lit ti de l tt eerr rraa zzzz oo ddee ll ii ii oo rrdd iinn ee pr es en ti ne l 3 ° s et to re ( f ig . 1 ). r is pe tto a i d ue p re ce de nt i s et to ri, il d ep os ito te rr az za to ap pa re m ag gi or m en te e ro so ; i n fig ur a è rip or ta ta la p re su nt a s up er fic ie s up er io re ( s s .g .) d is eg na ta a ss eg na nd o al d ep os ito m ar in o lo s te ss o sp es so re c he n ei te rr az zi d el 1 ° e 2° s et to re ( ci rc a 40 m ). l a pa le ol in ea d i r iv a (p lr .g .) r is ul ta in ta l m od o po si zi on at a a 11 0 m d i a lte zz a. l e os se rv az io ni e ffe ttu at e su lla li to fa ci es p ds h an no p er m es so d i c os tr ui re la c ol on na s tr at ig ra fic a di f ig . 22 , c he h a m es so b en e in e vi de nz a va rie o sc ill az io ni e us ta tic he ( c ap . 3 .6 .) . l a pa rt e a m on te d el te rr az zo è tr on ca ta d a un a se lla a lli ne at a lu ng o la fa gl ia in d ire zi on e 14 2° ( f ig . 3 8) . bb ) ii tt eerr rraa zzzz ii dd eell iiii ii oo rrdd iinn ee co m pa io no n el 3 ° s et to re in fo rm a m ol to r id ot ta r is pe tto a i d ue p re ce de nt i s et to ri. n el c as o es am in at o lo s pe ss or e de l d ep os ito m ar in o no n su pe ra i 56 m et ri (p ar ag r. 2. 3. 3. ); a ss eg na nd o al d ep os ito u no s pe ss or e an al og o a qu el lo d ei te rr az zi d el 1 ° e 2° s et to re , l a pa le ol in ea d i r iv a si c ol lo ca a lla q uo ta d i 7 1 m . p ar tia l p ro fil e of th e rid ge th at d es ce nd s fr om c al op ez za ti to w ar ds th e se a, in s ec to r 3, to th e rig ht o f t he f iu m ar el la t or re nt ( lin e d -d ’ i n f ig . 3 8) ; t he to po gr ap hi c da ta a re p ro je ct ed o n a ve rt ica l p la ne w ith a d ire ct io n of 2 7° . aa ) t he g eo lo gi ca l s ec tio n ta ke s in to a cc ou nt t he o bs er va tio ns m ad e on a ll 5 re m na nt s of t he tt eerr rraa ccee oo ff tthh ee 22nndd oorr ddee rr in s ec to r 3 (f ig . 1) . t he t er ra ce d de po si t se em s to b e m or e er od ed h er e th an in th e tw o pr ec ed in g se ct or s; th e pr es um ed u pp er s ur fa ce ( s s .g .) , d ed uc ed b y as si gn in g th e sa m e th ic kn es s as in th e pr ec ed in g te rr ac es ( ab ou t 4 0 m ) to th e m ar in e de po si t, is r ep or te d in th e fig ur e. i n th at w ay t he p al eo co as tli ne ( p lr .g ) is p os iti on ed a t a he ig ht o f 11 0 m . t he o bs er va tio ns m ad e on t he p ds li th of ac ie s m ad e it po ss ib le t o co ns tr uc t a st ra tig ra ph ic c ol um n of f ig . 22 , t ha t c le ar ly d is tin gu is he s th e va rio us e us ta tic o sc ill at io ns ( p ar ag r. 3 .6 .) . t he u ph ill p ar t o f t he te rr ac e is tr un ca te d by a n er os io n zo ne a lig ne d al on g th e fa ul t i n th e di re ct io n of 1 42 ° (f ig . 3 8) . bb ) t he ttee rrrr aacc ee ooff tthh ee 33rrdd oorr ddee rr ap pe ar m or e re du ce d in s ec to r 3 th an in th e pr ev io us o ne s. in th e ca se e xa m in ed th e th ic kn es s of th e m ar in e de po si t d id n ot e xc ee d 56 m ( p ar ag ra ph 2 .3 .3 ); a th ic kn es s an al og ou s to th at o f t he te rr ac es in s ec to rs 1 a nd 2 th at g iv es a p al eo co as tli ne o f a h ei gh t o f 7 1 m . t he s tr at ig ra ph y hi gh lig ht ed a c om pl ex s ed im en ta ry e vo lu tio n. è indubbio tuttavia che risultano mancanti (per erosione) parecchi metri dell’unità pelitica (pds). questa è caratterizzata da variazioni granulometriche e, in particolare, dalla presenza di più paleosuoli sovrapposti a diverse altezze (da p1 a p4 in fig. 22; es. in fig. 23). i paleosuoli inferiori si presentano neri o grigi, induriti, argillosi; quello alto (p4) mostra un colore 7,5 yr-4/6 con concentrazioni nere di fe e mn. c) considerazioni ambientali la complessa geometria legata alle variazioni di facies, ben evidenziata precedentemente, viene qui confermata. le osservazioni effettuate sulla unità peliti60 l. carobene fig. 21 terrazzo del ii ordine; settore 3°; quota 70 m; litofacies cb: conglomerato basale. i ciottoli si presentano quasi tutti appiattiti e con netta embriciatura verso nne (n30°); la facies è di battigia. in alto sabbie pelitiche che testimoniano la trasgressione marina. terrace of 3rd order; sector 3; altitude 70 m; cb lithofacies: basal conglomerate. almost all the pebbles are flattened with net imbrication towards the nne (n30°); shoreface facies. ochrecoloured pelitic sands at the top testify to transgression. fig. 22 stratigrafia riferita al terrazzo del ii ordine presente nel 3° settore (fig. 1). la colonna si riferisce alla parte centrale del corpo terrazzato (fig. 20a), dove è ben sviluppata la litofacies di retrobarriera pds (simboli litologici al paragr. 2.2.3.b.). nell’unità pelitico sabbiosa pds sono stati complessivamente riconosciuti 7 “orizzonti conglomeratici”, 3 orizzonti di “paleosuoli” (da p1 a p4) e 3 livelli a gusci di ostreidi (ostr.); essi testimoniano una successione di fasi di prosciugamento e di pedogenesi del bacino; di alluvionamento o di copertura di corpi ghiaiosi di battigia; di periodiche condizioni di laguna salata. in definitiva la colonna stratigrafica testimonia la costruzione polifasica del deposito terrazzato durante un unico “picco eustatico interglaciale”. stratigraphy of the terrace of the 2nd order in sector 3 (fig. 1). the column refers to the central part of the terraced body (fig. 20a), where the back-barrier lithofacies (pds) (lithological symbols in paragraph 2.2.3.b) are well developed. in the pds pelitic-sandy unit it is possible to identify 7 “conglomerate horizons”, 3 “paleosoil” horizons and 3 levels of ostreidi shells; these testify to a succession of drying up phases and the pedogenesis of the basin, flooding or covering by gravely shoreline bodies, and periodic saltwater lagoon conditions. the stratigraphic column testifies to the multiphase construction of the terraced deposit during a single “interglacial eustatic peak”. pds = freshwater, brackish, lagoon pelites; ags = beach ridge gravelysandy alternations; si = lower shoreface sands; cb = transgressive basal conglomerate; as = silty substratum clays (early-middle pleistocene). 61genesi, età, sollevamento ed erosione ... co-sabbiosa del 3° settore hanno messo bene in evidenza che il bacino lagunare o salmastro-dulcicolo, protetto dal cordone di spiaggia esterno, ha subìto più volte condizioni di prosciugamento, di pedogenesi, di alluvionamento o di copertura da parte di corpi ghiaiosi di battigia migrati verso terra. la presenza di ostreidi al tetto degli orizzonti 3, 4 e 5 (fig. 22) dovrebbe indicare il periodico ritorno a condizioni lagunari salmastre. ciò testimonia, come verrà ripreso al paragr. 3.6.), l’origine polifasica del terrazzo, causata verosimilmente da leggere oscillazioni eustatiche (nell’ambito di uno stesso alto picco eustatico interglaciale). in base ai sedimenti marini, ma soprattutto tenendo conto del loro spessore massimo riconosciuto nei due settori precedenti (circa 40 m), la paleolinea di riva più alta si posiziona alla quota di 110 m. 2.2.4. settore interno (a ne di crosia) un lembo relitto di corpo terrazzato ritrovato all’interno della valle del t. fiumarella, a 3,4 km dalla linea di riva attuale, permette di riconoscere come il mare relativo all’antico stazionamento, responsabile della formazione del terrazzo del ii ordine, formasse un’ampia insenatura in corrispondenza dell’attuale valle del t. fiumarella stesso. la profondità effettiva della paleoinsenatura si ricava considerando la posizione della paleolinea di riva nei vari settori studiati (fig. 24): essa rientrava per circa 1300 m. questo dato permette di calcolare l’innalzamento in quota della superficie inferiore marina del terrazzo (tratto rettilineo si.tr.), e di comprendere il fatto che oggi essa si trovi a 116-117 m di altezza, più alta quindi di 40-45 m rispetto ai settori costieri. la quota massima del corpo terrazzato marino, pari a 124 m, esclude d’altra parte che la tettonica abbia innalzato sensibilmente l’antica linea di riva che nel 2° settore, come sopra ricordato, arriva a 120 m s.l.m. a) aspetti geometrici il lembo di terrazzo marino in oggetto si presenta isolato a formare un piccolo rilievo (figg. 25 e 26) disposto lungo un crinale con andamento rettilineo che parte da cozzo s. pietro (277 m) e si perde nella piana alluvionale recente del t. fiumarella alla quota di 35 m (profilo c-c’ in fig. 38). la direzione del crinale è circa ene-oso (63°); essa risulta fortemente condizionata nel suo sviluppo da una faglia diretta con direzione 59° che rialza (in base ai dati del substrato) l’area a se del crinale stesso. il tratto relitto della superficie inferiore del terrazzo ha una lunghezza di 150 m; esso risulta leggermente inclinato verso mare di 1-2° (come si può osservare meglio da lontano) e si estende in quota da 116 a 117 m circa. la parte interna del terrazzo manca per erosione; una profonda incisione trasversale al crinale separa il lembo del deposito terrazzato a 124 m dal dosso a 135 m, posto a so e formato da sabbie del substrato (fig. 25). lo spessore del corpo terrazzato è di 8-10 m (fig. 26); esso risulta interamente marino ed è privo di copertura alluvionale. gli elementi descritti permettono una precisa correlazione con i lembi terrazzati costieri, in particolare con quelli del 2° settore, in quanto posti entrambi in sinistra del t. fiumarella. una conferma indiretta della paleo-insenatura è data da alcuni relitti di superfici terrazzate fluviali poste a 110-130 m di quota lungo i versanti vallivi a no; in alcuni casi è ancora presente un deposito ciottoloso e sabbioso a testimonianza dell’antica piana alluvionale, formatasi con un livello di base compatibile con la genesi di questo ordine terrazzato. b) aspetti litologici e sedimentologici la stratigrafia di questo deposito non è stata studiata in dettaglio; essa viene pertanto descritta a grandi linee (vedi colonna in fig. 25). alla base prevalgono, per 23 m di spessore, calcari arenacei (c.a.) ben cementati e grossolanamente stratificati; essi poggiano in discordanza su sabbie fini siltose del substrato (s.f.), immergenti a ne di 8-10° circa. seguono 5-6 m di arenarie (a.b.) mal classate, bioturbate, in parte bioclastiche, con aspetto massivo; il deposito è chiuso da un banco di calcare conchigliare (c.c.) spesso 1-1,5 m, molto cementato, verosimilmente di spiaggia intertidale. fig. 23 terrazzo del ii ordine; settore 3° (relitto di no in fig. 1); quota 80 m; litofacies: peliti di retrobarriera pds. ps) peliti sabbiose color grigio-nocciola; 2) intercalazione ciottolosa con ciottoli embriciati verso ovest (verso terra); p2) paleosuolo grigio-nero, massivo, limitato in alto da una superficie orizzontale (non visibile). le sigle corrispondono a quelle di fig. 22. l’intercalazione è di origine fluviale e il paleosuolo indica periodi di prosciugamento dell’area lagunare di retrobarriera. terrace of 2nd order; sector 3; altitude 80 m; lithofacies: back-barrier pds pelites. ps) greybrown coloured sandy pelites; 2) pebbly intercalations with imbricated pebbles towards the w (towards the land); p2) massive grey-black-coloured paleosoil, limited by a horizontal surface above (not visible). the signs correspond to those of fig. 22. the intercalations are of fluvial origin and the paleosoil indicates periods of drying up of the back-barrier lagoon area. c) aspetti ambientali il deposito descritto è l’unica testimonianza della sedimentazione marina all’interno di una profonda insenatura con asse circa ne-so, corrispondente all’attuale valle del t. fiumarella (fig. 24). le condizioni di mare più tranquillo e la minor disponibilità di materiale detritico rispetto alle spiagge esposte direttamente all’azione del mare, hanno favorito una sedimentazione carbonatico-detritica, a volte nettamente organogena, come testimonia il banco conchigliare che chiude in alto il deposito marino. la corrispondente antica linea di riva può collocarsi a 124 m, in relazione alla massima quota del deposito terrazzato marino. 22..33.. llee ssuuppeerrffiiccii tteerrrraazzzzaattee ddeell iiiiii oorrddiinnee,, ccoonn lliinneeaa ddii rriivvaa aa 6644÷÷7711 mm anche questo ordine di terrazzi viene descritto per settori uguali a quelli considerati per il ii ordine. esso mostra una variabilità di quote, da no verso se, che dipende come sempre da imprecisioni della carta topografica, dagli spessori variabili della copertura continentale, dal diverso grado di erosione delle superfici e dagli effetti della tettonica recente. proprio a causa delle coperture continentali non c’è coincidenza tra le quote dei margini interni m.i. (morfologici) delle superfici terrazzate e le quote delle antiche linee di riva sepolte (plr.g.). queste ultime sono state ricavate indirettamente mediante i profili geologici. nel 1° e nel 2° settore lo sviluppo lungo costa del terrazzo ha andamento no-se; i margini interni (m.i.) risultano infatti allineati in direzione 124° e i limiti esterni dei depositi (le.d.) in d. 122° (fig. 38). sigle tra parentesi in fig. 31. 2.3.1. primo settore (tra il f. trionto ed il fosso petrarovallone pomo) si riconoscono tre superfici ben sviluppate (fig. 1, simbolo 1): la prima è posta a no (vurdisca) ed ha margine interno a circa 70 m ed orlo esterno a 45-50 m; la seconda superficie (castello di mirto) e quella posta immediatamente a se, hanno margini interni a 65-70 e orli esterni a 50-55 m. a) aspetti geometrici (fig. 6-b) il corpo terrazzato sedimentario ha un’ampiezza trasversale alla costa variabile tra 250 e 400 m; il suo spessore massimo è di 25 m, compresa la copertura continentale. la superficie inferiore del terrazzo (tratto rettil ineo si.tr.) è inclinata di 0,7 gradi (valore calcolato); in figura essa si alza in quota da 40 a 43 m, limitata a monte da una paleofalesia sepolta che si chiude a 80 m. la superficie superiore (ss.r.) presenta un tratto a debolissima pendenza (circa 2°) tra 55 e 70 m; essa è separata dalla paleofalesia degradata a monte (scarpata interna) da una fascia colluviale (d.) a pendenza intermedia (4-7°). verso mare il corpo terrazzato appare nettamente troncato da una superficie di erosione (scarpata esterna se.r.), causata dal successivo stazionamento del mare a quote più basse (vedi paragr. 2.4.). l’erosione che si verificava al 62 l. carobene fig. 24 posizione delle antiche linee di riva del i, ii e del iii ordine. un lembo relitto di deposito terrazzato marino, con spessore di 8-10 m e quota massima di 124 m, ha permesso di riconoscere l’esistenza di un’ampia insenatura in corrispondenza dell’attuale valle del t. fiumarella (paragr. 2.2.4.). the position of the ancient coastlines of the 1st, 2nd and 3rd orders. the remains of a marine terrace deposit, with thickness of 8-10 m and maximum height 124 m. belonging to the 2nd order of terraces, made it possible to identify a small bay corresponding to the present day valley of the fiumarella torrent (paragr. 2.2.4.). (1) = present day coastline; (2) = foot of the slopes; (3) = alluvial deposits of the trionto river. 63genesi, età, sollevamento ed erosione ... f ig . 2 5 p ro fil o de l c rin al e (c -c ’ i n f ig . 3 8) c he s ce nd e da l p ae se d i c ro si a; in c or ris po nd en za d el la q uo ta 1 24 m ( s et to re in te rn o in f ig . 1 ) è co ns er va to u n le m bo r el itt o di u n de po si to m ar in o, ap pa rt en en te a l i i o rd in e di te rr az zi ( ve di s tr at ig ra fia l r . a la to ); le s ab bi e af fio ra nt i a lla q uo ta 1 35 m a pp ar te ng on o in ve ce a lla p ar te b as al e de l s ub st ra to p le is to ce ni co . i l d ep os ito te rr az za to in og ge tto h a pe rm es so d i r ic av ar e la c or ris po nd en te p al eo lin ea d i r iv a, c he r is ul ta in q ue st o se tto re p iù in te rn a di c irc a 13 00 m et ri ris pe tto a q ue lla r ic av at a ne i s et to ri 1, 2 e 3 ( f ig . 2 4) . p ro fil e of th e rid ge ( c -c ’ i n f ig . 3 8) th at d es ce nd s fr om th e vi lla ge o f c ro si a; a r el ic o f a m ar in e te rr ac e be lo ng in g to th e 2nd o rd er o f t er ra ce s (s ee s tr at ig ra ph y lr . t o th e si de ) is p re se rv ed a t a n al tit ud e of 1 24 m ( f ig . 1) ; th e sa nd s cr op pi ng o ut a t a he ig ht o f 13 5 m b el on g to t he b as al p ar t of t he p le is to ce ne s ub st ra tu m . t he t er ra ce d de po si t ha s m ad e it po ss ib le t o de du ce t he c or re sp on di ng p al eo sh or el in e, w hi ch is 1 ,3 00 m fu rt he r in la nd in th is s ec to r th an in s ec to rs 1 , 2 a nd 3 ( f ig . 2 4) . s . = s ub st ra tu m ; c .a . = a re na ce ou s lim es to ne s; a . = b io tu rb at e sa nd st on es ; c .c . = c al ca re ou s sh el ls to ne s. piede di questa scarpata (nei terreni argillosi del substrato) deve essere stata particolarmente intensa, tanto da determinare anche crolli del corpo terrazzato sovrastante. un grande blocco di sabbie fini siltoso-argillose laminate è ben visibile nell’abitato di stazione di mirto crosia, ai piedi della paleofalesia, con direzione anomala di 30°n (immersione a ono) e inclinazione di 25° (la giacitura normale degli strati è invece con immersione a n e inclinazione di 3°). b) aspetti litologici e sedimentologici gli scarsi punti di osservazione non hanno permesso una esauriente descrizione del deposito marino in tutto il suo sviluppo. sulla superficie inferiore di erosione marina poggia un deposito ruditico trasgressivo (cb) costituito da ciottoli a clasti poligenici ed eterometrici; i diametri prevalenti sono di 20-40 cm, con matrice di ghiaietto fine e scarsa sabbia. a volte sono osservabili strati di ghiaietto sabbioso-ciottoloso cementato seguito da sabbie; lo spessore può arrivare ad alcuni metri. segue una unità sabbioso-pelitica (pm), ben documentata. è costituita da sabbie fini siltose e silt argilloso-sabbioso, di colore giallo-ocra, con presenza di resti di lamellibranchi. il deposito si presenta laminato o stratificato, con superfici di stratificazione parallele debolmente inclinate (3°) verso nord. nella parte alta del deposito terrazzato affiorano, ben esposte, sabbie (si) a stratificazione parallela, immergenti di pochi gradi verso nord; sono caratterizzate da continue alternanze di: sabbie grosse, grigie e sciolte, con ciottoletti poggianti su superfici erosive; sabbie medie grigio-giallastre, laminate poco cementate; sabbie fini siltose, più cementate. le superfici di stratificazione sono irregolari; lo spessore degli strati variabile. dovrebbero indicare la zona esterna alle barre (shoreface inferiore). la parte alta del corpo marino è probabilmente rappresentata da alternanze sabbioso-ciottolose di battigia (ags), non ben documentate. chiude la successione marina un deposito ruditico alluvionale (cc), composto da ciottoli eterometrici, fino a 30-40 cm di diametro alla base, ricco in matrice a piccoli clasti spigolosi, sabbia e pelite. questa copertura continentale, che ha spessore di 2-5 m, si presenta fortemente pedogenizzata (colori munsell fino a 2,5yr4/6 e 3/4) e costituisce probabilmente la base di un paleosuolo quasi totalmente eroso (fig. 27). nella parte interna del terrazzo il deposito cc è ricoperto da colluvium limoso-ciottoloso molto arrossato. c) considerazioni ambientali le osservazioni effettuate nel 1° settore sui lembi terrazzati del iii ordine hanno documentato molto bene la presenza di due unità in eteropia di facies tra loro: le sabbie inferiori si e le peliti marine pm, rappresentative della spiaggia sottomarina inferiore e di transizione. la spiaggia alta ed emersa occupava la parte interna del terrazzo, ora ricoperto da parecchi metri di alluvioni ciottolose pedogenizzate; essa non è stata pertanto ben documentata. risulta assente in questo settore l’unità pelitica di retrospiaggia (pds), che invece compare nei settori a se. in base alla quota massima dei sedimenti marini e alla ricostruzione geometrica della superficie superiore del terrazzo (ss.g.), la paleolinea di riva si colloca a 64 m s.l.m. (valor calcolato). 2.3.2. secondo settore (tra il fosso petraro ed il t. fiumarella) il terrazzo è caratterizzato da 2 superfici relitte maggiori (loc. fulitano); esse si sono originate dallo sviluppo della rete idrografica minore, compresa tra il fosso petraro a no ed il t. fiumarella a se, che le ha ulteriormente suddivise verso mare (fig. 1, simbolo 1). morfologicamente le superfici terrazzate sono comprese tra le quote di 75 m (margine interno) e di 55-60 m (orlo esterno). a) aspetti geometrici (fig. 14-b) il corpo terrazzato sedimentario ha una ampiezza trasversale alla costa variabile da 500 a 800 m; esso risulta quindi più conservato rispetto al terrazzo descritto nel settore 1. lo spessore massimo del deposito terrazzato, compresa la copertura continentale, è di 25 m, uguale a quella del settore 1. nella ricostruzione effet64 l. carobene fig. 26 terrazzo del ii ordine; settore interno (fig. 1); quota massima 124 m; litofacies dal basso (stratigrafia in fig. 25): calcari arenacei (c.a.); arenarie bioturbate (a.); banco di calcare conchigliare (c.c.). l’immagine mostra il lembo relitto del deposito terrazzato, poggiante su sabbie fini (sf) del substrato, che testimonia la paleoinsenatura illustrata in fig. 24. terrace of 2nd order; internal sector (fig. 1); maximum altitude 124 m; lithofacies from the bottom (stratigraphy in fig. 25): arenaceous limestones (c.a.); bioturbate sandstones (a.); bank of calcareous shellstone (c.c.). the picture shows the remains of the terraced deposit, lying on the fine sands (sf) of the substratum. tuata in fig. 14-b, la superficie inferiore del terrazzo (tratto rettilineo) si alza in quota da 42 a 49 m, con inclinazione (calcolata) di 0,7°; è limitata a monte da una paleofalesia sepolta (pf.s.) che si chiude a 85 m. la superficie superiore (ss.r.), estesa tra 55 e 75 m, presenta una inclinazione media di 2°, mentre tratti a debolissima pendenza (1°) sono compresi tra le quote di 60 e 70 m; la superficie superiore è separata dalla paleofalesia degradata (pf.d.) a monte da una fascia colluviale con inclinazione di 5-8°. verso mare il corpo terrazzato è troncato dalla scarpata esterna (se.r.) che, tra le quote di 60 e 20 m ha una inclinazione media di 10° (nel settore 2). poiché lo sviluppo lungo costa del terrazzo avviene in direzione 123° (valore medio: v. paragr. 2.3.), tutti i dati raccolti nell’area del settore 2 sono stati proiettati secondo tale direzione sul piano verticale della sezione geologica di fig. 14-b, al fine di una loro integrale utilizzazione. b) aspetti litologici e sedimentologici i punti di osservazione effettuati hanno permesso una buona ricostruzione della stratigrafia, che appare caratterizzata da vistose eteropie di facies legate al processo trasgressivo e alla successiva migrazione della linea di riva verso il largo; ciò integra quanto osservato nel terrazzo del 1° settore. sulla superficie inferiore del terrazzo, tagliata nel substrato argilloso, poggia un debole spessore di ciottoli ben arrotondati (unità ruditica trasgressiva cb). seguono sabbie da medio-fini a grosse, grigie, sciolte; a volte si presentano laminate, siltose, leggermente cementate, immergenti a ne di 4-6 gradi, (unità sabbiosa si). ben documentato risulta il successivo corpo ghiaioso-sabbioso (alternanze ghiaioso-sabbiose ags), costituito da sabbie grossolane, conglomerati e ghiaietto, con spessore non superiore a 6-8 m; gli strati sono inclinati di 3-5° verso mare. la parte alta mostra sets di sabbie grossolane con lenti di ciottoli arrotondati inclinati di 7-10° verso ne: essi indicano chiaramente il progradare della spiaggia verso la stessa direzione, cioè verso mare (facies di battigia – fig. 28). nel deposito si possono riconoscere diverse facies della spiaggia alta (foreshore). questo corpo è chiuso in alto da peliti grigio-scure, con rare lenticelle di sabbia e ghiaietto (unità pelitica pds), il cui spessore aumenta verso terra fino a 10 m. in questa zona interna del terrazzo le peliti argillose con giacitura suborizzontale vengono sostituite da siltiti sabbiose e, verso l’alto, da sabbie pelitiche inclinate di 4° verso ne (fig. 29), inclinazione indotta dalla chiusura verso monte del bacino. uno scavo studiato nel 1987 (con il prof. g. rodolfi) ha evidenziato molto bene la sovrapposizione del deposito pelitico (pds) sulle alternanze ghiaiososabbiose di spiaggia (ags); l’unità pds mostra nella parte alta un suolo grigio-bruno con segregazione di carbonati nella parte bassa. esso si sovrappone ad un altro suolo, color grigio molto scuro, a struttura prismatica grossolana, con patine d’argilla sulle superfici degli aggregati. i paleosuoli indicano episodi di emersione dell’area di retrospiaggia, come verrà confermato dallo studio condotto nel 3° settore (paragr.2.3.3.). la successione marina sopra descritta è chiusa dalla unità ruditica alluvionale (cc) che segna la regressione marina e quindi il sopravvento dell’ambiente continentale. il deposito presenta clasti eterometrici con arrotondamento variabile, abbondante matrice mal classata, lenti sabbiose, ciottolose e pelitiche mal definite e locali embriciature dei ciottoli verso monte. la litologia di ciottoli è caratterizzata da abbondanza di calcari; da scarse arenarie e da graniti alterati. i colori 5yr-3/3 (a volte 2,5yr-3/4) indicano la forte alterazione del deposito; il suo spessore può raggiungere i 5-6 metri. la zona di raccordo tra la superficie terrazzata ed il versante a monte (paleofalesia degradata) è caratterizzata da forti spessori di colluvium limoso-sabbioso o limoso-ciottoloso pedogenizzato (7,5yr-3/4) e indurito. c) considerazioni ambientali il deposito terrazzato rappresentato in fig. 14-b mostra una perfetta analogia con il deposito terrazzato più alto (stessa figura, sez. a). viene quindi confermato il meccanismo di formazione di questi ampi terrazzi. la posizione dell’antica lliinneeaa ddii rriivvaa è stata determinata geometricamente (plr.g.) sulla base della quota 65genesi, età, sollevamento ed erosione ... fig. 27 terrazzo del iii ordine; settore 1°; quota 65 m; località vurdisca; litofacies cc: deposito ruditico a ciottoli in prevalenza arrotondati, in matrice sabbioso-limosa. l’embriciatura dei ciottoli verso sud (a destra) testimonia l’origine alluvionale del deposito, che costituisce la copertura pedogenizzata dei depositi marini terrazzati. terrace of 3rd order; sector 1; altitude 65 m; locality: vurdisca; cc lithofacies: ruditic deposit, with prevalently rounded pebbles, in a muddy-sandy matrix. the imbrication of the pebbles towards the s testifies to the alluvial origin of the material that constitutes the pedogenised cover on the terraced marine deposits. massima dei depositi marini: essa risulta a circa 70 m s.l.m. 2.3.3. terzo settore (in destra del t. fiumarella) il terrazzo del iii ordine è rappresentato in quest’area da poche superfici, molto erose, con ampiezza che progressivamente si riduce fino a sparire verso se (fig. 1). la causa può essere dovuta sia ad una originaria minor ampiezza del terrazzo (rispetto all’analogo ordine presente in sinistra del t. fiumarella), sia ad una forte erosione costiera tipica di questo settore di costa (come già ipotizzato precedentemente al paragr. 2.2.3.), ad opera degli stazionamenti marini più bassi, successivi all’emersione del terrazzo. ciò sembra confermato dall’inclinazione della scarpata esterna in argilla, che può essere considerata una paleofalesia degradata, oggi protetta da circa 200 m di piana costiera: essa si sviluppa infatti da 50 a 10 m di quota con una inclinazione media di 15°, valore quindi doppio rispetto a quello medio di 8° calcolato nei settori in sinistra del t. fiumarella. a) aspetti geometrici (fig. 20-b) sono stati riconosciuti 3 relitti terrazzati, con ampiezza compresa tra 100 e 200 m. su due superfici sono stati osservati lembi ridotti di una copertura ciottolosa; in corrispondenza della terza invece il corpo terrazzato ha uno spessore massimo di una decina di metri (contro i 25 m osservati nei due settori settentrionali). le osservazioni su questo deposito furono effettuate nel gennaio del 1991 (assieme al prof. g. rodolfi); attualmente l’antropizzazione dell’area rende molto difficile riconoscere la stratigrafia allora osservata, così come ostacola un controllo delle quote e delle misure in genere. per questo motivo i valori riportati in fig. 20b possono essere affetti da un errore di almeno 5 m. la superficie inferiore del terrazzo (tratto rettilineo) si sviluppa in quota tra 47 e 50 m circa; la superficie superiore presenta la minima inclinazione tra 57 e 62 m circa, con angolo di 1,4° (valore calcolato). anche questo terrazzo si è formato, come nei casi precedenti, a spese del precedente terrazzo superiore. b) aspetti litologici e sedimentologici il corpo sedimentario marino risulta in questo settore di dimensioni ridotte e non fornisce perciò le stesse indicazioni emerse nei settori precedenti. sulle argille del substrato poggia direttamente un deposito ciottoloso sciolto, con clasti aventi diametro fino a 20-30 cm, ben arrotondati, sfericizzati ed appiattiti, alterati con colore 7,5yr-5/5; lo spessore è di qualche metro. nella parte centrale del terrazzo un ampio solco d’erosione è riempito da sabbie giallastre con livelli ghiaiosi nella parte inferiore e ricoperte da limi scuri pedogenizzati, formanti un suolo nero (vertisuolo) che mostra nella parte inferiore un evidente livello biancastro a carbonati (fig. 30). il tutto è ricoperto da depositi colluviali a monte e da debris-flow fangoso-ciottoloso bruno nella parte esterna del terrazzo. c) aspetti ambientali il ridotto spessore del deposito marino non permette di calcolare direttamente la posizione dell’antica linea di riva sollevata; ciò può essere fatto indirettamente, in base alla quota della superficie inferiore ed allo spessore del corpo sedimentario marino desunto dalle sezioni precedenti (spessore massimo di circa 22 m). si ricava in tal modo geometricamente che la linea di riva (plr.g.) dovrebbe collocarsi a circa 71 m s.l.m. attuale (contro i 64 m del 1° settore ed i 70 m del 2°). la situazione stratigrafica sopra esposta permette di riconoscere la seguente schematica evoluzione del terrazzo: deposizione del corpo sedimentario marino; emersione con pedogenesi e fase di erosione continentale con formazione di profondi solchi sulla superficie del terrazzo; riempimento con sabbie mal classate e livelli ghiaiosi dei solchi stessi; episodio palustre con deposizione di limi argillosi; pedogenesi; ulteriori fasi di ricoprimento ad opera di depositi colluviali. 66 l. carobene fig. 28 terrazzo del iii ordine; settore 2°; quota 55 m; località valle di carro; litofacies visibili dal basso: (ags) livelli di ghiaietto fine inclinati di 5° verso nord, che terminano in alto con ciottoli appiattiti nettamente embriciati verso mare (a destra); ambiente di battigia. (ss) sabbie medio-grosse con ciottoli sparsi; probabile ambiente di spiaggia emersa. (pds) deposito limoso con rare lenticelle di sabbia e ghiaietto, separato dalle sabbie sottostanti da una superficie inclinata di 2-3° verso nord; ambiente palustre o lagunare. terrace of 3rd order; sector 2; altitude 55 m; locality: valle di carro; lithofacies visible from below: (ags) levels of fine gravel dipping 5° towards the n, terminating above with flattened pebbles netly imbricated towards the sea; shoreface environment. (ss) medium-coarse-grained sands with scattered pebbles; probably subaerial beach environment (backshore). (pds) muddy deposit with occasional lenticels of sand and gravel, separated from the underlying sands by a surface inclined 2-3° towards the n; swampy or lagoon environment. 22..44.. llee ssuuppeerrffiiccii tteerrrraazzzzaattee ddeell iivv oorrddiinnee,, ccoonn lliinneeaa ddii rriivvaa aa 2255÷÷3300 mm tra 20 e 30 metri di quota è riconoscibile, lungo tutta la fascia costiera esaminata, l’ordine di terrazzi più basso. si tratta di piccole superfici intagliate nelle argille del substrato, nella quasi totalità manomesse per scopi agricoli ed in parte deformate o addirittura cancellate da fenomeni franosi. pertanto le descrizioni risultano carenti; tuttavia l’esistenza del terrazzo è confermata da un evidente aspetto morfologico che caratterizza i versanti rivolti verso mare: una netta rottura di pendenza separa il versante compreso tra le isoipse di 30 e 50 m (scarpata esterna del sovrastante terrazzo del ii ordine) ed il versante compreso tra 20 e 30 m di quota. il primo tratto ha una inclinazione media di 25° (intervallo 20-30°); il tratto più basso ha invece una inclinazione media di circa 7° (intervallo 5-10°). questo tratto poco inclinato corrisponde alle superfici del iv ordine. il paese di stazione di mirto crosia è costruito proprio tra 20 e 30 m di quota. a) aspetti geometrici sono stati cartografati 7 relitti di superfici (da t1 a t7 in fig. 1), con ampiezza compresa tra 100 e 170 m; l’inclinazione della superficie superiore del terrazzo risente della presenza di depositi colluviali nella parte a monte e dell’erosione nella parte verso mare, per cui l’intervallo altimetrico entro il quale si sviluppa la superficie terrazzata è genericamente posto tra le isoipse di 20 e 30 metri. b) aspetti litologici e sedimentologici il corpo terrazzato marino è stato in gran parte rimosso o rimaneggiato dalle arature; su tre superfici tuttavia si sono potuti osservare ancora piccoli lembi di depositi sabbioso-ciottolosi. in particolare sulla superficie t4 (ad ovest del km 319) (fig. 1) è ancora preservato un deposito marino costituito in basso da 30 cm di sabbie medio-grosse, sciolte, classate, ricoperte da circa 1 m di ghiaie a ciottoli eterometrici, ben arrotondati, spesso appiattiti, con diametri massimi di 10-20 cm. 67genesi, età, sollevamento ed erosione ... fig. 29 terrazzo del iii ordine; settore 2°; quota 55-60 m; località cozzo del finocchio; litofacies pds: siltiti laminate color nocciola chiaro, interrotte da livelli sottili e irregolari di sabbie grosse grigio-scuro; la parte centrale (priva di sabbie grosse), appare bioturbata. gli strati immergono debolmente (2-4°) verso ne. ambiente: lagunare. terrace of 3rd order; sector 2; altitude 55-60 m; locality: cozzo del finocchio; pds lithofacies: light-brown-coloured laminate siltstones, interrupted by thin, irregular levels of dark-grey coarse sands; the central part (lacking coarse-grained sands) appears bioturbate. the layers dip weakly (2-4°) towards the ne. lagoon environment. fig. 30 terrazzo del iii ordine; settore 3; quota 50-55 m; litofacies: peliti pds. ap= argille siltose palustri pedogenizzate; lc= livello ricco di carbonati; sn= paleosuolo nero (vertisuolo); sb= suolo bruno su colluvium rimaneggiato. terrace of 3rd order; sector 3; altitude 50-55 m; lithofacies: pds pelites. ap= silty, marshy pedogenised clays; lc= carbonate-rich layer; sn= black paleosol (vertisol); sb= brown soil on reworked colluvium. inglobato tra i ciottoli anche un blocco di circa 80 cm di diametro di calcareniti algali abbastanza arrotondato; esso deriva dai calcari algali caratteristici del i ordine di terrazzi. il deposito, la cui base non è stata osservata, si presenta alterato, con colori ocra. numerosi blocchi di calcareniti stratificate, più o meno arenacee, sono stati inoltre accumulati dai contadini ai bordi del campo; essi dovevano far parte dell’originario deposito terrazzato marino. sulla superficie t6 infine (ad ovest di cappella s. giacomo) un netto ripiano mostra sulla superficie ciottoli arrotondati, decimetrici, ed un frammento di strato di calcarenite algale. c) considerazioni ambientali la ridotta ampiezza delle superfici ed il debole spessore dei depositi, permettono di dedurre che la formazione di questo terrazzo più basso sia da attribuire ad uno stazionamento marino di durata assai minore rispetto a quelli più antichi (e più alti). questa considerazione verrà tenuta presente nell’inquadramento cronologico dei terrazzi (cap. 3.2.). l’antica linea di riva può essere posizionata tra 25 e 30 m s.l.m. 33.. aassppeettttii ggeeoommeettrriiccii,, ggeenneettiiccii,, ssttrraattiiggrraaffiiccii eedd eevvoolluuttiivvii ddeeii tteerrrraazzzzii mmaarriinnii in questo capitolo le osservazioni di campagna vengono utilizzate per formulare considerazioni, a carattere sia locale che generale, su molti aspetti legati alla genesi dei terrazzi marini ed alla loro trasformazione nel tempo. in particolare le considerazioni esposte nei 13 paragrafi toccano cinque argomenti principali: a) geometria e nomenclatura (3.1.) b) genesi ed età (3.2. e 3.3.) c) aspetti litologici, stratigrafici, sedimentologici e facies (3.4. – 3.5. – 3.6. – 3.7. – 3.8.) d) eustatismo e tettonica (3.9. – 3.10. – 3.11. – 3.12.) e) processi erosivi e rimodellamento (3.13.) 33..11.. llaa ggeeoommeettrriiaa ee llaa nnoommeennccllaattuurraa ddeeii tteerrrraazzzzii per terrazzo marino si intende comunemente una superficie costiera suborizzontale o leggermente inclinata verso mare, esposta a causa del sollevamento, delimitata verso terra e verso mare da scarpate o versanti più o meno ripidi. però un terrazzo rimodellato dall’erosione (vedi 3.13.) può identificarsi in maniera assai diversa, ovvero con tratti di crinali suborizzontali, con ondulazioni consecutive di quota simile lungo un crinale che scende verso mare, con rilievi (culminazioni topografiche) isolati a quote ricorrenti, con piccoli lembi di depositi (carobene & firpo, 2002). è limitativo considerare il terrazzo una caratteristica morfologica del paesaggio (come enunciato sopra), in quanto il terrazzo è “il risultato di più processi” avvenuti nel tempo, anche di quelli che hanno agito dopo l’emersione ed il sollevamento, in particolare il rimodellamento e l’attività tettonica. per questi motivi può succedere che l’identificazione di un singolo terrazzo avvenga mediante la correlazione di tanti aspetti distinti: genetici, sedimentari, geometrici, morfologici, ecc.; ad essi bisogna dare una denominazione differente a seconda di quello che rappresentano. in questi casi è spesso necessario “ricostruire geometricamente” l’originaria superficie; essa comprenderà al suo interno tutte le forme distinte o i depositi che ne rappresentano oggi la testimonianza. la fig. 31 sintetizza i vari aspetti evidenziati nello studio dei terrazzi di crosia-calopezzati e la corrispondente nomenclatura (si rimanda alla didascalia della figura per la descrizione dettagliata); in particolare occorre evidenziare: a) la superficie inferiore (si.g.) è composta da un tratto rettilineo a bassa pendenza (0,5-1°) e da un tratto interno curvo con pendenza media 6-8 volte maggiore. tale geometria della superficie inferiore presenta grandi analogie con il modello di “wave-cut platform” descritto da bradley & griggs (1976) per i terrazzi della california centrale; la piattaforma è suddivisa in un “offshore segment”, rettilineo, con inclinazioni di 0,4-1° e con ampiezze che possono superare i 2000 m, e in un “inshore segment”, leggermente concavo, inclinato di 1,2-2,3°, ampio 300-600 metri (v. anche 3.10.c). b) la superficie superiore rimodellata (ss.r.) comprende rilievi isolati costituiti da lembi più o meno erosi del deposito, oppure da relitti della originaria superficie superiore suborizzontale terrazzata; su questi ultimi i paleosuoli sono più sviluppati e meglio conservati; c) l’intersezione tra la superficie superiore (geometricamente ricostruita) e la paleofalesia (geometricamente ricostruita) si può convenzionalmente assimilare alla paleolinea di riva (più alta) (plr.g.) (vedi 3.11.); la posizione analoga a plr.g. è chiamata “shoreline angle” da kern (1977) e “inner edge” da bradley & griggs (1976). il tema della definizione geologica e morfologica dei terrazzi è stato affrontato già da tempo dagli autori sopra citati (bradley, 1957; bradley & griggs, 1976; kern, 1977), ma sempre in maniera non esauriente. c’è confusione nella terminologia, come, ad esempio, nel caso dei due termini più utilizzati: orlo esterno e margine interno; essi si ricavano dalle carte e dalle foto aeree e pertanto devono avere senza equivoci un significato morfologico. in bradley & griggs (1976) è chiamato invece “outer edge” il punto che in fig. 31 è indicato come “limite esterno del deposito terrazzato”; lo stesso punto viene chiamato “toe” in kern (1977). il modello quantitativo proposto in fig. 31 potrà essere utilizzato come riferimento per le descrizioni dei terrazzi in genere: tuttavia i terrazzi marini possiedono alcuni elementi in comune, ma anche altri aspetti di volta in volta diversi, che dipendono dai fattori locali che ne hanno influenzato la loro formazione. tra i principali fattori si possono ricordare: a) il substrato (vedi 3.3.); b) i caratteri dello stazionamento marino (vedi 3.11.); c) le condizioni meteomarine e, in particolare, l’energia delle onde; d) la morfologia dei fondali; e) il detrito a disposizione lungo costa e gli apporti fluviali(vedi 3.7.); f) il clima; g) la tettonica (vedi 3.12.). 33..22.. eettàà ee ssoolllleevvaammeennttoo ddeeii tteerrrraazzzzii occorre premettere che “l’età del terrazzo” è un termine ambiguo, anche se molto usato. l’argomento è già stato affrontato da carobene (1981) che ha distinto una “età riferita alla formazione del deposito marino terrazzato” e una “età riferita allo sviluppo nel tempo del terrazzo inteso come forma”. più semplice è il caso di una singola “linea di riva” riferibile ad un preciso “livello 68 l. carobene 69genesi, età, sollevamento ed erosione ... f ig . 3 1 m od el lo d i t er ra zz o m ar in o ric av at o da i d at i e sp os ti ne l c ap . 2 . i l t er ra zz o no n vi en e co ns id er at o so la m en te u na fo rm a, m a an ch e un c or po g eo lo gi co ( an al og am en te a c on oi de , m or ena , e cc .) ; l a ge om et ria in te rn a ed e st er na d el te rr az zo è s ta ta p er ci ò ac cu ra ta m en te d es cr itt a ed è s ta ta a rr ic ch ita la r el at iv a no m en cl at ur a. l ’u til iz zo d el m od el lo p er m et te d es cr iz io ni q ua nt ita tive ( di d is ta nz e, q uo te , an go li) in di sp en sa bi li pe r ef fe ttu ar e co nf ro nt i a tte nd ib ili . a ) p ro fil o di u n te rr az zo c he m os tr a i v ar i a sp et ti de lla s up er fic ie s up er io re r im od el la ta , de lla s up er fic ie in fe rio re , de lla p al eo fa le si a a m on te e d el la s ca rp at a es te rn a a va lle . il rim od el la m en to c on se gu en te a ll’ em er si on e de l t er ra zz o e al s uo s ol le va m en to ( ve di f ig . 41 ) pr od uc e un a se rie d i r el itt i, da lla c ui in te rp ol az io ne è p os si bi le r ic os tr ui re g eo m et ric am en te ( b ) la s up er fic ie s up er io re e q ui nd i a nc he a ltr i e le m en ti ca ra tte ris tic i, tr a cu i l a po si zi on e de lla p al eo -l in ea d i r iv a (p lr .g .) . m od el o f a m ar in e te rr ac e de du ce d fr om t he s tu dy o f th e c ro si ac al op ez za ti ar ea . t he t er ra ce s ho ul d no t be c on si de re d pu re ly a s a fo rm , bu t al so a s a ge ol og ic al b od y (a na lo go us t o fa n, m or ai ne , e tc .) ; h ow ev er , t he in te rn al a nd e xt er na l g eo m et rie s ha ve b ee n ac cu ra te ly d es cr ib ed a nd h as e nr ic he d th e re la tiv e no m en cl at ur e. t he u se o f t he m od el h as m ad e it po ss ib le to m ak e qu an tit at iv e de sc rip tio ns ( of d is ta nc e, h ei gh t, an gl es ) in di sp en sa bl e fo r m ak in g re lia bl e co m pa ris on s. a ) p ro fil e of a te rr ac e sh ow in g th e va rio us fe at ur es o f t he d eg ra de d up pe r su rf ac e (s s .r .) , lo w er s ur fa ce ( s i.g .) , l an dw ar d pa le os ea cl iff ( p f .) , e xt er na l s lo pe ( s e .r .) a nd p al eo sh or el in e (p lr .g ). o .e . = o ut er m or ph ol og ic al e dg e; m .i. = in ne r m or ph ol og ic al m ar gi n; l e .d = e xt er na l l im it of th e te rr ac ed d ep os it. t he r em od el lin g fo llo w in g th e em er si on a nd u pl ift in g of th e te rr ac e (s ee f ig . 4 1) p ro du ce d a se rie s of r el ic s (1 , 2 , 3 ) fr om w hi ch it is p os si bl e to g eo m et ric al ly r ec on st ru ct (p ro fil e b ) th e up pe r su rf ac e (s s .g .) a nd a ls o th e ot he r ch ar ac te ris tic e le m en ts , i nc lu di ng th e po si tio n of th e in ne r ge om et ric m ar gi n (m .i. g. ) an d th e ou te r ge om et ric e dg e (o .e .g .) . di stazionamento marino” (vedi 3.11.); il terrazzo invece, forma complessa corrispondente ad un “alto picco eustatico interglaciale” si forma in un intervallo di tempo di migliaia di anni (3.10.b), e con tale intervallo dovrebbe essere in realtà indicata l’età di un terrazzo. in particolare ciò vale quando è presente un deposito terrazzato marino che costituisce, a tutti gli effetti, una unità litostratigrafica, alla quale corrisponde un intervallo cronostratigrafico ben preciso. quanto detto spiega come mai le datazioni effettuate sui coralli dei terrazzi recifali si distribuiscano molto spesso in intervalli cronologici di 5.000-15.000 anni (chappell & veeh, 1978; chen et alii, 1991; ku et alii, 1990; mush et alii, 1994, ecc.). il problema si risolve assegnando un’età alla più alta linea di riva riconosciuta dallo studio del terrazzo. ciò è stato fatto: a) tenendo conto dell’età del substrato; b) utilizzando una datazione th/u sui calcari algali del i ordine; c) paragonando il sollevamento dell’area studiata a quello delle aree immediatamente limitrofe; d)correlando gli ordini terrazzati agli stages interglaciali della curva isotopica dell’ossigeno (mis). a) lo studio micropaleontologico delle successioni del substrato ed anche dei corpi terrazzati è in corso; le relative indicazioni biostratigrafiche non vengono pertanto riportate nella presente nota. la successione argillosa pleistocenica, che costituisce il substrato dei terrazzi, appare comunque in gran parte riferibile al pleistocene medio, analogamente a quanto emerso nell’area del f. crati (carobene et alii, 1997). ciò è confermato da una datazione con tracce di fissione di un orizzonte vulcanoclastico (bigazzi, com. or.) presente nella successione argillosa. conseguentemente la formazione dei vari ordini di terrazzi deve collocarsi nella parte terminale del pleistocene medio e nel pleistocene superiore. b) una datazione th230/u234 eseguita nel 1995 presso i laboratori enea amb/saf (casaccia-roma) su un campione di calcare algale non trattato e su un secondo campione soggetto a trattamento fisico preliminare ha fornito date comprese tra 297.676 e 407.233 anni e quindi al limite del metodo. pertanto il campione ha un’età maggiore di 300.000 anni. c) per inquadrare il sollevamento nell’area del f. trionto, sono stati esaminati i dati del sollevamento quaternario nelle aree limitrofe. gli studi sui terrazzi marini condotti nella calabria settentrionale ionica, in particolare a no della piana di sibari, hanno sufficientemente definito l’entità del sollevamento con valutazioni nel complesso simili. il lavoro di cucci & cinti (1998) fornisce una velocità media di sollevamento negli ultimi 700.000 anni di 0,57 mm/anno. a so dell’area studiata, il massiccio silano si è sollevato con velocità medie di 0,5 mm/a nell’ultimo milione di anni (ciaranfi et alii, 1983), ma probabilmente con valori maggiori nella zona 70 l. carobene 1 2 3 4 5 6 7 età quota quota sollevamento del piccolo stage tassi delle antiche paleostazionamento medio del picco curve di ordini linee di riva più caldo climatiche sollevamento (metri) (metri) (metri) (anni) (mm/anno) x1000 i 210 +5 (205) 330 9c (0,62) +10 200 405 11c 00,,4499 ii 105÷120 -10 122 240 7e 00,,5511 iii 64÷71 +5 62 125 5e 00,,5500 iv 25÷30 -15 42 85 5a 00,,4499 (-10) (37) 105 5c (0,35) tab. 1 in colonna 2 sono riportate le quote attuali delle antiche linee di riva sollevate relative ai 4 ordini di terrazzi riconosciuti; i valori sono affetti da un errore di circa ±5 m. in colonna 3 sono riportate le probabili quote degli antichi paleostazionamenti marini riferiti ai massimi picchi interglaciali, desunti e mediati da diversi autori (aharon & chappell, 1986; bender et alii, 1979; chappell & shackleton, 1986; dodge et alii, 1983; mush et alii, 1994; pirazzoli et alii, 1991; shackleton, 1987; williams et alii, 1998). si è inoltre tenuto conto dell’altezza dei picchi delle curve paleoclimatiche, dalle quali si può avere un’idea delle quote dei paleolivelli assumendo che un cambiamento di 0,1 ‰ del δ18 equivalga a 10 m (harmon et alii, 1983; shackleton, 1987). i possibili errori non sono inferiori a ±5 m. in colonna 4 sono riportati i valori dei sollevamenti; per il iv ordine si è tenuto conto che la sua formazione può essere attribuita sia al substage 5a che al 5c; per il i ordine, ritenuto policiclico, è più probabile che la linea di riva più alta sia da attribuire all’interglaciale più antico, cioè allo stage 11c. la colonna 5 riporta le età dei picchi più alti delle curve paleoclimatiche (da winograd et alii, 1997). nella colonna 6 sono indicati i substages corrispondenti alle età della col. 5. la colonna 7 infine riporta i tassi di sollevamento calcolati in base alle colonne 4 e 5; i valori riferiti ai substages 5c e 9c (posti tra parentesi) sono ritenuti meno probabili. uplift rates. the present-day elevations of the uplifted ancient shorelines of the 4 orders of terraces identified are reported in column 2; the values are affected by an error of about ±5 m. the probable elevations of the ancient paleohighstands of the maximum interglacial peaks, as deduced and published by various authors (aharon & chappell, 1986; bender et alii, 1979; chappell & shackleton, 1986; dodge et alii, 1983; mush et alii, 1994; pirazzoli et alii, 1991; shackleton, 1987; williams et alii, 1998) are reported in column 3. the elevations of the peaks of the paleoclimatic curve, from which it is possible to get an idea of the altitudes of the paleolevels, assuming that a change of 0.‰ of δ18 equals 10 m (harmon et alii, 1983; shackleton, 1987), have been taken into consideration. the possible errors are not less than ±5 m. the uplift values are reported in column 4; the fact that the formation of the 4th order can be attributed to substages 5a and 5c and that the highest coastline of the 1st order, considered polycyclic, can be attributed to the most ancient interglacial, that is stage 11c, has been taken into consideration. the age of the highest peaks of the paleoclimatic curve (from winograd et alii, 1997) is reported in column 5. the substages corresponding to the ages in column 5 are given in column 6. the rates of uplift, calculated on the basis of columns 4 and 5 are reported in column 7; the values referring to substages 5c and 9c (in parentheses) are considered less probable. assiale a partire dal pleistocene medio (moretti & guerra, 1997); nella valle del f. crati, interposta tra la sila e la catena costiera tirrenica, sono stati calcolati valori di sollevamento di circa 0,7 mm/a per i l pleistocene medio e superiore (carobene et alii, 1997). nel settore ionico a se dell’area del f. trionto, sono stati da tempo studiati i terrazzi della penisola crotonese (selli, 1962; belluomini et alii, 1988); una ricerca di palmentola et alii (1990) ha permesso di calcolare un tasso di sollevamento medio pari a 0,4 mm/a a partire dallo stage 9. pertanto l’area del f. trionto si trova compresa tra aree con valori di sollevamento variabili da 0,4 a 0,7 mm/anno. in base a questa analisi regionale, è stato correlato all’ultimo interglaciale (eutirreniano) il iii ordine di terrazzi, con linea di riva a 64÷71 m, in quanto la sua attuale quota comporta un sollevamento medio di 62 m (vedi tab. 1) pari ad un tasso di 0,50 mm/a; tale valore è il più coerente con quelli sopra esposti, riferiti alle aree limitrofe. l’attribuzione del terrazzo del iii ordine all’ultimo interglaciale viene confermata al successivo punto d). d) le considerazioni e i dati esposti nei precedenti punti a) e b) impongono che i 4 ordini di terrazzi ritrovati si siano formati in coincidenza degli ultimi alti eustatici interglaciali, a loro volta correlati agli stages caldi della curva isotopica dell’ossigeno. tuttavia il terrazzo del iv ordine, con linea di riva a 25÷30 m (paragr. 2.4.), presenta deboli spessori di depositi ed ha scarsa evidenza morfologica, pur essendo il più recente: non può per dimensioni essere paragonato a quelli più alti e non può quindi essere assegnato al picco dell’ultimo interglaciale 5e che, per importanza, è equiparabile agli interglaciali corrispondenti agli stages 7, 9 e 11. di conseguenza è più verosimile attribuirlo ai substages minori 5a o 5c. il terrazzo del iii ordine va quindi correlato allo stage 5 (substage 5e); il terrazzo del ii ordine (con linea di riva a 105÷120 m) si correla al precedente stage 7 (substage 7e) e il terrazzo del i ordine (con linea di riva a 210 m) si correla agli stages 9 (substage 9c) e 11 (substage 11c) (dalla curva climatica di winograd et alii, 1997). per concludere, questa cronologia ricavata indirettamente e per via deduttiva trova una forte giustificazione nell’età del substrato (pleistocene medio) e nella datazione dei calcari algali del i ordine di terrazzi. le età attribuite ai 4 ordini terrazzati hanno permesso di costruire lo schema di tab. 1. i tassi di sollevamento risultano assai coerenti tra loro e forniscono una velocità media di sollevamento pari a 0,50 mm/anno circa. 33..33.. iill rruuoolloo ddeell ssuubbssttrraattoo nneell pprroocceessssoo ttrraassggrreessssiivvoo uno degli “elementi” caratteristici del terrazzo marino è la superficie inferiore (si. in fig. 31); essa taglia il substrato con inclinazione e lunghezza variabili. gli studi sulle coste alte rocciose (anderson et alii, 1999; sunamura, 1992) hanno fornito relazioni tra i vari aspetti della costa e le forze in gioco. con particolare riferimento all’area in esame, il substrato ha condizionato lo sviluppo della superficie inferiore in maniera duplice. il primo aspetto riguarda la litologia e la struttura del substrato, ovvero stratif icazione e giacitura. nell’area di crosia calopezzati il substrato è costituito da argille più o meno siltose, immergenti a n con angoli di inclinazione di 10-15°. solamente la parte alta del terrazzo del i ordine poggia su un substrato costituito da sabbie poco cementate che costituiscono la base della successione pleistocenica; le argille esposte direttamente all’azione delle onde originano falesie verticali che, erose alla base, crollano velocemente. se non si forma una spiaggia abbastanza ampia alla base della falesia (fig. 32), capace di assorbire l’energia delle onde, l’arretramento della falesia è rapidissimo e di conseguenza si sviluppa una piattaforma marina suborizzontale assai ampia. il secondo aspetto riguarda invece l’azione causata dal detrito generato dalla distruzione del substrato ad opera delle onde. se la costa è costituita da litotipi duri, il materiale derivante dall’arretramento della falesia va a costituire il detrito di fondo che, mobilizzato dall’azione delle onde, acquista potere abrasivo contribuendo così 71genesi, età, sollevamento ed erosione ... fig. 32 esempio di falesia argillosa attiva (fa) presente nella penisola di crotone. il suo rapido arretramento è documentato dai blocchi di argilla presenti alla base e non ancora asportati dal moto ondoso. la falesia è scarsamente protetta da una sottile spiaggia (s) di sabbia rossastra; sullo sfondo invece sono visibili i blocchi franati (bf) provenienti dal deposito del terrazzo marino (t) sviluppato a 25-30 m di quota; essi formano un frangiflutto naturale che protegge la falesia, che ha acquistato pertanto una pendenza minore. example of active clayey cliff (fa) on the crotone peninsula. its rapid retreat is documented by the clay blocks at its foot that have still not been carried away by wave action. in the foreground, the cliff is poorly protected by a narrow beach (s) of reddish-coloured sand. instead, in the background the blocks (bf) that have fallen from the deposit of the marine terrace (t) that developed at an altitude of 25-30 m, and now lie at the foot of the cliff, form a natural breakwater that protects it. thus the cliff has acquired a lesser inclination here. a formare una tipica “piattaforma di abrasione marina”. se la quantità di detrito è alta e viene solo in parte asportata dalle onde e dalle correnti, allora con il tempo si accumula opponendosi così all’azione abrasiva e all’arretramento della falesia. nell’area in esame tutto il materiale argilloso poteva venire rapidamente allontanato, dando così origine ad una “piattaforma di erosione marina”, dove il principale fattore di avanzamento è stato lo scalzamento al piede della falesia. 44)) llaa vvaarriieettàà ddeellllee ffaacciieess sseeddiimmeennttaarriiee lo studio dei depositi terrazzati marini nell’area di crosia-calopezzati ha evidenziato la presenza di numerose litofacies (cap. 2). il rilevamento di campagna si è basato soprattutto sulle osservazioni dei principali caratteri tessiturali e sulla descrizione di alcune strutture sedimentarie. i risultati del rilevamento (vedi figg. 14, 20, 25) sono stati schematizzati nel modello di fig. 33: esso mostra grandi analogie con i noti modelli di una sequenza deposizionale regressiva tipica di una spiaggia progradante (hoyt, 1967; hunter et alii, 1979; nummedal & swift, 1987; oertel et alii, 1992; reinson, 1992). nel complesso le litofacies risultano essere abbastanza indicative dei principali ambienti di una spiaggia, acquistando quindi anche un significato di facies sedimentarie. in questo senso tuttavia le litofacies descritte costituiscono spesso più delle associazioni di facies, che delle facies singole. si preferisce pertanto riassumere la descrizione dei depositi terrazzati mediante le 9 litofacies riconosciute, correlandole di volta in volta agli ambienti di spiaggia (spiaggia emersa, battigia e zona intertidale, spiaggia sottomarina superiore e inferiore, zona di transizione). utili sono stati i confronti con le situazioni riportate in massari et alii (1986), massari & parea (1988) e in parea & valloni (1983). 11)) litofacies (cb): conglomerato basale trasgressivo corpo ruditico di modesto spessore composto da ciottoli con diametri prevalenti di 10-30 cm, ma fino a 50-100 cm; deposito a volte ben cernito. clasti poligenici di forma subsferica e appiattita; arrotondamento molto buono (fig. 34); i clasti di grande diametro sono stati probabilmente ereditati da preesistenti depositi alluvionali (vedi 3.8.). matrice scarsa, formata da ghiaietto e 72 l. carobene fig. 33 modello di distribuzione delle litofacies riconosciute dallo studio dei terrazzi marini del ii e del iii ordine nell’area di crosiacalopezzati. il significato ambientale delle litofacies e la geometria dei depositi sono indicativi di un sistema costiero barriera-laguna; esso si è formato con una fase iniziale trasgressiva, i cui depositi costituiscono un “insieme di sistemi deposizionali trasgressivi tst”; il corpo sedimentario si è poi sviluppato nella successiva fase di alto stazionamento eustatico con la progradazione del cordone di spiaggia ghiaioso-sabbioso che ha originato un ampio bacino di retrobarriera da dulcicolo a salato, caratterizzato da peliti sabbiose pds. il processo di progradazione-aggradazione ha originato i depositi che costituiscono un “insieme di sistemi deposizionali di stazionamento alto hst”. la figura riporta la distribuzione delle litofacies e la loro attribuzione ambientale; a-b è la traccia ideale del paleo-versante costiero, la cui inclinazione risulta di 3-4°. distribution model of the lithofacies identified in the study of the marine terraces of the 2nd and 3rd orders in the crosia-calopezzati area. the environmental significance of the lithofacies and the geometry of the deposits is that they are indicative of a coastal barrier-lagoon system; this was formed during an initial transgressive phase, whose deposits constitute a transgressive systems tract; the sedimentary body then developed in the successive eustatic highstand phase with the progradation of the gravely-sandy beach ridge that created a wide freshwater-salty back-barrier basin (b.r.), characterised by sandy pelites (pds). the progradation-aggradation process created the deposits that constitute a highstand systems tract. the figure reports the distribution of the lithofacies and their environmental attribution; a-b is the ideal line of the coastal paleoslope whose inclination is 3-4°. mfs = maximum flooding surface. the lithofacies symbols are explained in point 4 of the abstract. sabbia grossa; ciottoli appiattiti embriciati verso mare, con angoli da 10 a 45°. a volte il deposito è sostituito da strati di arenaria grossolana e ghiaie cementate (fig. 21). la litofacies è indicativa di una battigia ad alta energia. 22)) litofacies (pm): peliti marine alternanze di peliti sabbiose e di sabbie fini siltose in parte bioturbate, a volte con resti di lamellibranchi. laminazione piano parallela, in strati inclinati di 2-4°. la litofacies, presente nel settore 1, nei terrazzi del ii e del iii ordine, dovrebbe indicare peliti offshore, al limite con la spiaggia sottomarina. 33)) litofacies (si): sabbie grigie inferiori e’ rappresentata da alternanze di sabbie fini, a volte pelitiche e bioturbate, con sabbie grosse, grigie. gli strati sono generalmente continui e paralleli, localmente discontinui, in quanto le sabbie grosse, a volte ricche di ciottoletti, poggiano su superfici erosive; esse sono caratterizzate da laminazione incrociata con forti variazioni granulometriche. l’inclinazione degli strati è compresa tra 4 e 6° (fig. 9). la litofacies è indicativa della spiaggia sottomarina (shoreface) inferiore e della zona di transizione con la piattaforma. 44)) litofacies (ags): alternanze ghiaioso-sabbiose comprende sabbie grosse, ghiaietto millimetrico, ghiaie centimetriche e frequenti clasti appiattiti embriciati verso mare, il cui diametro può arrivare a 20 cm. le alternanze di sabbia grossolana e ghiaietto sono ben classate; le superfici di stratificazione sono pressocché parallele (struttura cuneiforme a basso angolo), inclinate di 5-8° verso mare; esse costituiscono superici erosive sulle quali poggiano i clasti più grossi (fig. 35 e 28 e 10). questa litofacies s’identifica bene con la battigia (beach face) o con la zona intertidale (foreshore) di una spiaggia ghiaiosa; è probabile che essa comprenda, in certi casi, anche la zona delle barre (shoreface superiore). 55)) litofacies (ss): sabbie gialle superiori e’ caratterizzata da sabbie da medio-fini a grosse; a volte vi è alternanza di strati sabbiosi e ciottolosi, separati da superfici erosive; la stratificazione, quando visibile, ha inclinazioni di 4-5° verso mare. il deposito ricopre le peliti di retrospiaggia (pds) (punto successivo) (fig. 13). la varietà degli aspetti potrebbe indicare varie facies, caratteristiche sia della spiaggia intertidale che di quella emersa. 66)) litofacies (pds): peliti dulcicole-salmastre-lagunari e’ costituita da argille, argille siltose, silt argillosi e sabbie pelitiche, in alternanze molto sottili; sono presenti a volte anche sottili livelli di piccoli ciottoli. il colore va dal grigio scuro al giallo-grigio. tre elementi la caratterizzano: -intercalazioni (im) ciottoloso-sabbiose di battigia (vedi paragr. 2.2.3.b); -intercalazioni ciottolose fluviali (ic); -paleosuoli sovrapposti che, assieme alle intercalazioni, indicano episodi di emersione, ovvero fluttuazioni eustatiche (fig. 29 e 22). la litofacies è indicativa di bacini di retrospiaggia, separati dal mare aperto da barriere (frecce, lidi) più o meno continue. 77)) litofacies (ca-ab-cc): calcari arenacei-arenarie bioturbatecalcari conchigliari sono stati riuniti in un’unica voce i diversi aspetti di un deposito marino attribuito al ii ordine di terrazzi (paragr. 2.2.4.), formatosi all’interno di un piccolo golfo lungo la costa (fig. 24). la caratteristica principale è la presenza di un banco di calcare conchigliare avente spessore di 1-1,5 metri, formatosi nella parte alta della spiaggia intertidale in condizioni di alta energia, o forse per accumulo di gusci nella spiaggia emersa. 88)) litofacies (ca): calcari algali caratterizza i depositi relitti del terrazzo del i ordine. forma banchi spessi 1-2 m, biocalcarenitici, ricchi di noduli algali (fig. 4), ben cementati, poggianti (in apparenza) direttamente sul substrato argil loso; i calcari algali sono a volte compresi tra 73genesi, età, sollevamento ed erosione ... fig. 34 terrazzo del ii ordine; settore 3°; quota 70 m; lembo terrazzato di quota 87 in fig. 38; litofacies cb. ciottoli arrotondati del conglomerato trasgressivo basale rimaneggiati dai lavori di aratura; sullo sfondo un lembo integro del deposito terrazzato (dt), evidenziato dallo stacco morfologico con le argille del substrato. terrace of 2nd order; sector 3; altitude 70 m; terraced remains at an altitude of 87 m in fig. 38; cb lithofacies. rounded pebbles of the basal transgressive deposit reworked by ploughing; there is a remnant of a terraced deposit (dt) in the background, highlighted by the morphological difference from the clays of the substratum. depositi ghiaiosi poveri di matrice (paragr. 2.1.b). 99)) litofacies (cc): conglomerati continentali corrisponde ad un deposito ruditico a clasti eterometrici, mal classato, ricco di matrice ghiaioso-sabbioso-limosa, con tipica struttura a lenti irregolari, talora a clasti appiattiti embriciati verso terra (fig. 27). si presenta sempre pedogenizzato (colori da 2,5 yr-4/6 a 5yr-4/6); può essere ricoperto da colluvium o mud-flow. la litofacies è indicativa di depositi di piana alluvionale in forte espansione (fase di sovralluvionamento e di conoide di deiezione). 33..55.. llaa ssttrraattiiggrraaffiiaa sseeqquueennzziiaallee aapppplliiccaattaa aaii ddeeppoossiittii tteerr-rraazzzzaattii ddeell iiii ee ddeell iiiiii oorrddiinnee il consistente spessore che caratterizza i depositi del ii ordine di terrazzi (fino a 45 m) e del iii ordine (fino a 25 m), e la loro suddivisione in litofacies distinte che individuano corpi sedimentari tra loro in eteropia di facies, permette di riconoscere agevolmente due sequenze deposizionali indicative di un sistema costiero barriera-laguna. in entrambi gli ordini esse sono limitate inferiormente dalla superficie di discordanza trasgressiva causata dalla risalita eustatica riferibile al rispettivo periodo interglaciale; superiormente le sequenze sono troncate dalla superficie erosiva continentale coincidente con il top dei depositi pedogenizzati di piana alluvionale o con le superfici erosive derivanti dal rimodellamento dei depositi marini, conseguente alla fase di regressione glacioeustatica. applicazioni della stratigrafia sequenziale ad un corpo terrazzato non sono noti allo scrivente; tuttavia applicazioni simili sono state effettuate per la trasgressione olocenica, che è stata riconosciuta e descritta in piane costiere subsidenti mediante carotaggi e stratigrafia sismica ad alta risoluzione (amorosi et alii, 1999; bellott i et ali i , 1995; ridente & trincardi, 2002; robustelli & aucelli, 2002; shipp, 1984). lungo la costa centro-meridionale del brasile, martin et alii (1988) hanno riconosciuto 4 ordini di terrazzi sollevati, caratterizzati da depositi riconducibili a sistemi barriera-laguna. le 9 litofacies sintetizzate al precedente paragr. 3.4. (e più ampiamente descritte nel cap.2) sono raggruppabili in un “insieme di sistemi deposizionali trasgressivi” (transgressive systems tract = tst) e in un “insieme di sistemi deposizionali di stazionamento alto” (highstand systems tract = hst) (fig. 33). a) insieme di sistemi trasgressivi (tst) e’ rappresentato: dalla litofacies cb (ghiaie trasgressive di battigia) alla quale spesso fanno seguito alcuni metri di sabbie via via più fini verso l’alto; dalla litofacies si (sabbie di spiaggia sottomarina); dalla litofacies più profonda pm (peliti e sabbie della zona di transizione spiaggia sottomarina/piattaforma); dalla litofacies ags (alternanze ghiaioso-sabbiose della spiaggia intertidale ed emersa). lo spessore di tst non supera mai i 10 m, ma generalmente è di 4-6 metri; esso è riconoscibile dalla geometria delle parasequenze che indicano con precisione il passaggio tra la fase trasgressiva di onlap e la successiva fase progradante che ha originato la costruzione di gran parte del corpo sedimentario: il corpo trasgressivo tst e quello progradante-aggradante hst sono separati dalla “superficie di massima ingressione” (maximum flooding surface = mfs); inferiormente ad essa la sequenza verticale di facies è sempre positiva (ad es. cb-si-pm, oppure cb-ags-si). superiormente invece la sequenza di facies è negativa (ad es. pm-si, oppure si-ags). b) insieme di sistemi di stazionamento alto (hst) e’ costituito dalle litofacies (fig. 33) pm, si, ags e inoltre dalle peliti sabbiose pds (da lagunari a dulcicole); queste ultime hanno riempito il bacino di retro-barriera che man mano si ampliava con il progradare verso il largo del cordone di spiaggia ghiaioso-sabbioso. gli strati di pds, inclinati di pochi gradi, sono in onlap sul corpo ags; lo stacco tra pds e ags è netto. il passaggio verso terra è meno evidente, in quanto è spesso rappresentato da un contatto argille-argille; a volte tuttavia è marcato da deboli spessori di depositi ciottolosi. le parasequenze di hst sono chiaramente in downlap sulla superficie mfs; gli strati inclinano infatti da 2 a 8° sulla superficie di massima ingressione, la cui inclinazione non supera 1,5°. all’interno di hst sono riconoscibili momenti trasgressivi (orizzonti im e ss) e regressivi (paleosuoli sepolti), ma essi non modificano la generale architettura di questo sistema di alto stazionamento. 74 l. carobene fig. 35 terrazzo del ii ordine; settore 1°; litofacies: passaggio dalle sabbie inferiori (si) alle alternanze ghiaioso-sabbiose (ags). terrace of 2nd order; sector 1; lithofacies: change from lower sands (si) to gravely-sandy alternations (ags). c) il sistema deposizionale regressivo non è stato riconosciuto; esso si è sviluppato a quote più basse e quindi spostato verso il largo. la formazione dei terrazzi successivi (del iii ordine rispetto al ii, e del iv rispetto al iii) ha eroso la parte esterna dei corpi terrazzati (figure 6, 14, 20) contribuendo probabilmente alla sua distruzione. d) durata delle sequenze deposizionali le sequenze deposizionali descritte si sono formate durante due alti eustatici interglaciali (vedi 3.2.) corrispondenti allo stage 7e per il ii ordine e allo stage 5e per il iii ordine di terrazzi (corrispondenze da winograd et alii, 1997). il sistema trasgressivo tst si è formato quando la velocità di risalita del livello del mare è rallentata a tal punto che la persistente azione del mare a quote simili ha dato inizio alla formazione della superficie trasgressiva. in base alle figure 6, 14 e 20 il livello del mare si è innalzato, durante questa fase trasgressiva, di 10-20 metri, durante la quale la sedimentazione risulta ridotta, probabilmente a causa di scarsi apporti terrigeni. merita di essere evidenziato il fatto che la superficie trasgressiva basale si è formata molto prima del raggiungimento della massima quota del livello marino interglaciale; un ruolo fondamentale è stato evidentemente giocato dalla natura argillosa del substrato (vedi 3.3.), in quanto il meccanismo di formazione della piattaforma di erosione marina si innesca (in questi casi) evidentemente anche con velocità di sollevamento eustatico ancora sensibili. la seconda fase comprende quindi gran parte del periodo di massimo eustatico interglaciale, durante il quale (sempre in base alle figure 6, 14 e 20), il livello del mare si è alzato di altri 15-25 metri. l’imponente fenomeno di contemporanea progradazione-aggradazione del sistema barriera-laguna, che caratterizza la seconda fase, ha richiesto un regime di abbondante apporto terrigeno. 33..66.. ggeenneessii ppoolliiffaassiiccaa ddeell tteerrrraazzzzoo ee rraappppoorrttii ccoonn ll’’eeuussttaa-ttiissmmoo la campionatura della successione pelitica (pds) effettuata in località cozzo del finocchio (settore 2) ha evidenziato faune essenzialmente dulcicole (dati non riportati in questo lavoro); essa poggia alla quota di circa 84 m sull’unità ghiaioso-sabbiosa (ags) e termina circa alla quota di 105 m (fig. 14). intercalati a questa unità argilloso-siltosa si sviluppano due orizzonti sabbioso-ciottolosi: il primo di 3 m di spessore tra 95 e 98 m circa, il secondo tra 100 e 102 m circa s.l.m. (fig. 17 e 37). alla base essi presentano ciottoli arrotondati, spesso appiattiti; seguono alternanze (sets) sabbiose e di ghiaietto millimetrico, con ciottoli appiattiti centimetrici embriciati verso mare; la stratificazione è cuneiforme, quasi parallela, con immersione verso mare e inclinazione di 7°. ogni set è composto da sabbia o ghiaietto ben classato e privo di matrice; verso l’alto la sabbia diventa più massiva e omogenea. i due orizzonti sono pertanto indicativi della facies di battigia e forse, in alto, di spiaggia emersa. nel settore 3, in destra fiumarella, la correlazione tra i vari punti osservati ha permesso di costruire la colonna di fig. 22: essa mostra a varie altezze orizzonti conglomeratico-sabbiosi anch’essi indicativi di battigia (paragr. 2.2.3.), oltre a due livelli conglomeratici più bassi, forse fluviali. i tre orizzonti marini più importanti si sviluppano alle quote (approssimative) di 84-85 m, 9091 m e 93-94 m. poiché la successione di cozzo del finocchio appare rialzata per faglia di 10 m rispetto a quella del 3° settore (fig. 14 –lato so), i due orizzonti di battigia prima citati si abbassano (eliminando il rigetto di 10 m) a 85-88 e a 90-92 m, risultando quindi ben correlabili con quelli del 3° settore. l’alternanza tra fasi marine e di continentalità, con sviluppo di suoli, è stata ben documentata anche nel terrazzo del iii ordine (paragr. 2.3.2.), per cui si può concludere che la genesi dei terrazzi del ii e del iii ordine ha avuto un carattere nettamente polifasico, la cui causa è da imputare a oscillazioni eustatiche (anche lievi) capaci di determinare un’alternanza di condizioni di emersione e di sommersione. la geometria dei corpi terrazzati rappresentata nelle figure potrebbe perciò essere ancora più articolata e complessa di quanto appaia, anche perché il corpo sedimentario non ha registrato gli eventuali stazionamenti successivi al picco eustatico più alto (fase regressiva); stazionamenti avvenuti ovviamente a quote più basse e i cui corrispondenti depositi sono stati erosi dalla formazione del successivo ordine terrazzato. 33..77.. rraappppoorrttii ttrraa iinnppuutt ddii mmaatteerriiaallee ddeettrriittiiccoo eedd eevvoolluuzziioo-nnee ddeeii tteerrrraazzzzii la fase di sollevamento di tutta l’area è seguita al periodo di forte abbassamento del margine costiero ionico che aveva dato origine ad un cuneo sedimentario con spessore (verso mare) non inferiore a 500 m (dati inediti); questa fase tettonica, che lo ha portato in parte ad emergere di quasi 300 m nel corso del pleistocene medio e superiore (nell’area in esame), ha coinciso con una ripresa dell’attività delle faglie in un regime deformativo prevalentemente estensionale (ciaranfi et alii, 1983; ghisetti, 1981; ghisetti & vezzani, 1983; moretti & guerra, 1997). le faglie quaternarie sono state ben riconosciute nell’area in esame (vedi 3.12. e fig. 38), ma hanno agito con intensità anche in tutta l’area silana diventando sicuramente una causa di produzione di detrito; il contemporaneo sollevamento ha inoltre innescato i processi erosivi e franosi e ha dato inizio allo sviluppo e all’approfondimento della rete idrografica (sorriso valvo, 1993). l’ingente quantità di materiale detritico proveniente dallo smantellamento dei rilievi e dall’incisione delle valli ha alimentato i depositi dei terrazzi descritti, caratterizzati da spessori di decine di metri. in particolare lo studio dei terrazzi ha evidenziato con chiarezza che, dopo la fase trasgressiva che ha portato il mare (in concomitanza con i vari periodi interglaciali) a originare superfici di erosione estese fino a 1000 m per il ii ordine e fino a 2300 m per il i ordine, è seguita una fase di progradazione della spiaggia e quindi di accentuata regressione deposizionale (figg. 6, 14 e 20). ciò è da mettere in relazione con i forti apporti detritici del f. trionto, che disperdeva lungo costa sabbie e ghiaie. la battigia progradante, ed il cordone di spiaggia emersa ad essa collegato, si allontanava dalla terraferma lasciandosi alle spalle un’area depressa, anche perché ciò avveniva in regime di innalzamento eustatico. si può pertanto dedurre che si formassero veri e propri lidi (v. 3.5.) che delimitavano ampi bacini lagunari che di volta in volta, in conseguenza di lievi 75genesi, età, sollevamento ed erosione ... abbassamenti eustatici o per chiusura delle bocche lagunari, potevano trasformarsi in bacini salmastri o dulcicoli. questo modello ambientale è stato condizionato dall’input di materiale detritico portato dal f. trionto. come già anticipato al paragr. 2.2.3., la quantità di sedimento lungo-costa diminuiva progressivamente verso se; ciò determinava una progradazione più lenta e di conseguenza la formazione di bacini di retrospiaggia sempre più ristretti. 33..88.. iill rriicciiccllaaggggiioo ddeeii ddeeppoossiittii tteerrrraazzzzaattii nell’area in esame ogni ordine di terrazzi si è formato, almeno in parte, a spese dell’ordine immediatamente superiore. questa caratteristica è particolarmente evidente per i terrazzi del ii e iii ordine (figg. 6, 14 e 20), ma il fenomeno è avvenuto anche tra il iv ed il iii ordine e tra il ii ed il i; una ricostruzione geometrica dei corpi sedimentari dei terrazzi del ii e iii ordine permette di ipotizzare una loro troncatura verso mare di centinaia di metri. ciò significa che durante la sua formazione ogni terrazzo ha utilizzato i sedimenti marini e continentali del terrazzo immediatamente più antico. questo importante fenomeno (molto frequente nel quaternario) presenta almeno 3 aspetti interessanti relativi a: a) quantità dei materiali riciclati; b) variazioni nella litologia, nelle dimensioni e nella forma dei clasti nel loro passaggio da un terrazzo alto ad uno più basso; c) origine primaria dei clasti e, in particolare, dei ciottoli con dimensioni pluridecimetriche. per quanto riguarda il punto a), ci si può fare un’idea analizzando la fig. 14: il fronte del deposito terrazzato del ii ordine (paleofalesia) era alto non meno di 45 metri. questo significa che l’erosione di un fronte esteso lungo costa per cento metri, per la profondità di 1 metro e per l’altezza sopra citata di 45 m, forniva un volume di materiale clastico pari a 4.500 m3. il sedimento era formato da conglomerati basali trasgressivi (cb), da sabbie (si e ss), da peliti marine e, forse, di retrospiaggia (pm e pds) e da conglomerati continentali sabbioso-limosi (cc). i ciottoli di maggiori dimensioni venivano riutilizzati per formare il nuovo conglomerato basale (vedi avanti al punto c); sabbie e ghiaie (con clasti centimetrici) per costituire la spiaggia; le peliti invece erano portate lontano da riva in sospensione. sul punto b) si possono formulare solamente ipotesi; appare logico che nel riciclaggio ci sia diminuzione dei litotipi più erodibili, diminuzione della grandezza e ulteriore arrotondamento dei ciottoli, e quindi che si formi un sedimento “più maturo”. in verità la presenza di ruditi alluvionali, con spessori di 5-10 m, al top dei sedimenti marini, contribuiva sicuramente a “ringiovanire” il sedimento marino in via di formazione. le considerazioni sul punto c) forniscono la prova più sicura del fenomeno del riciclaggio, e quindi del fatto che il deposito marino (non quello continentale) di un terrazzo si sia in parte formato “cannibalizzando” il deposito marino e continentale del terrazzo immediatamente superiore. i ciottoli del conglomerato basale sono ben arrotondati, a volte sfericizzati, pur poggiando direttamente sul substrato argilloso; il loro diametro arriva a 50-100 cm nel terrazzo del i ordine; fino a 40-50 cm nel terrazzo del ii ordine; fino a 30-40 cm in quello del iii ordine; fino a 20 cm in quello del iv ordine. solamente il terrazzo del i ordine intaglia le sabbie pleistoceniche di crosia e calopezzati; gli altri (come già detto) tagliano il substrato argilloso. poiché clasti così grandi non potevano certo muoversi lungo riva, si può ipotizzare che la fonte sia stato il deposito di un terrazzo più alto o di una superficie di spianamento continentale ricoperta da conoidi alluvionali. un’altra prova del riciclaggio è fornita dai calcari bioclastici algali osservati sul terrazzo del i ordine; in origine essi formavano (paragr. 2.1.) “piastroni” rigidi spessi 1-2 metri. blocchi di calcari algali sono presenti anche nei depositi degli ordini più bassi, ma sempre abbastanza arrotondati (quindi rielaborati dalle onde) e perforati da litodomi. anche nel deposito del iv ordine (paragr. 2.4.) è stato osservato un blocco di 80 cm di diametro. 33..99.. ssppoossttaammeennttoo vveerrssoo tteerrrraa ddeellllee lliinneeee ddii rriivvaa ssoolllleevvaattee il sollevamento quaternario dell’area costiera studiata, così come dell’intero massiccio della sila (v. aa. al paragr. 3.7.), ha portato ad emergere anche il cuneo sedimentario del pleistocene inferiore-medio, che oggi affiora fino alla quota di 277 m (cozzo s. pietro). durante il sollevamento, gli alti livelli eustatici degli ultimi interglaciali (vedi 3.2.) hanno formato un caratteristico terrazzamento a gradinata (fig. 36). questo ha comportato che, nel tempo, le antiche linee di riva del i, ii, iii e iv ordine si siano progressivamente “allontanate” verso terra rispetto alla linea di riva successiva, e quindi rispetto all’attuale. pertanto all’aumentare del sollevamento corrisponde un aumento delle distanze dalla linea di riva attuale; questa regola è visualizzata in fig. 36 mediante triangoli. hai è il triangolo relativo alla più alta linea di riva rinvenuta nel settore 1 (paragr. 2.1.); alla quota di 210 m corrisponde una distanza dalla linea di riva attuale di 4800 m e l’angolo nel vertice a è uguale a 2,5°. la linea di riva del ii ordine è posta a 105 m e ad una distanza di 2400 m (triangolo fag): l’angolo nel vertice a è uguale a 2,5°. la linea di riva del iii ordine è alla quota di 65 m e alla distanza di 1250 m (triangolo dae): l’angolo al vertice a è uguale a 3°. per la linea di riva a +30 m circa (triangolo bac) l’angolo al vertice a è invece di 2,1°. i valori angolari calcolati sono indipendenti dall’età assegnata alle paleolinee di riva, ma dipendono da almeno due fattori: a) entità di arretramento della falesia, che è in gran parte in funzione del substrato (vedi 3.3.); se l’arretramento è più forte l’angolo diminuisce (substrati tenei), e viceversa (substrati duri). b) durata del periodo interglaciale; se la durata è maggiore, l’arretramento aumenta e l’angolo diminuisce. per dare una giusta interpretazione al valore angolare bisogna quindi conoscere la natura del substrato e la durata dell’interglaciale corrispondente ad ogni linea di riva. nel caso illustrato in fig. 36, i valori angolari relativi al i e al ii ordine sono identici; per il terzo ordine invece il valore è maggiore (3° anziché 2,5°). ciò può essere dovuto ad una maggior difficoltà di arretramento della falesia, causata dall’enorme quantità di detrito sabbioso-ghiaioso derivante dall’erosione del corpo terrazzato del ii ordine (vedi 3.8.). i valori angolari possono essere utilizzati per caratterizzare i terrazzi di un determinato settore costiero o per operare confronti tra aree costiere diverse. 76 l. carobene la fig. 36 permette inoltre di calcolare la velocità di allontanamento (rapporto distanza-età) delle antiche linee di riva: per il iii ordine, considerato tirreniano, la velocità (media) è 1 cm/anno; per il ii ordine, attribuito allo stage 7, la velocità è ancora 1 cm/anno; per il i ordine la velocità aumenta a 1,5 cm/anno. poiché il valore della velocità di allontanamento dipende dall’età attribuita alle antiche linee di riva, si può avanzare l’ipotesi che la linea di riva a +210 m sia più antica di 320.000 anni (stage 9), e sia quindi da assegnare allo stage 11 (circa 400.000 anni). in questo caso “la velocità di allontanamento” diventa 1,2 cm/anno, rendendo plausibile l’ipotesi già espressa che il terrazzo del i ordine sia policiclico (vedi 3.2.), cioè il risultato complessivo degli alti eustatici degli stages 9 e 11. ciò spiegherebbe bene sia la sua anomala ampiezza (2.300 m), sia il forte dislivello tra margine interno e orlo esterno (80 m), in parte attribuibile alla tettonica (paragr. 2.1.a). 33..1100.. vveelloocciittàà ddii aarrrreettrraammeennttoo ddeellllee ffaalleessiiee ((vv..aarr..)) nel precedente paragr. 3.9. è stata definita “la velocità di allontanamento delle antiche linee di riva” come il rapporto distanza-età calcolabile per ognuna di esse. la distanza (dalla linea di riva attuale) è ovviamente proporzionale all’ampiezza delle superfici di abrasione, la quale a sua volta è tanto maggiore quanto più veloce è stato l’arretramento delle falesie. la “velocità di allontanamento” delle antiche linee di riva (dalla loro formazione ad oggi) dipende quindi in certa misura dalla “velocità di arretramento delle paleofalesie”; tale velocità di arretramento deve però essere calcolata in base all’effettivo intervallo di tempo che è stato necessario per creare la superficie di erosione inferiore del terrazzo. si può provare a calcolare la v.ar. conoscendo: a) la durata dello stadio climatico interglaciale; b) la durata dell’alto eustatico interglaciale corrispondente; c) la correlazione tra formazione del corpo terrazzato e la durata dell’alto eustatico; d) la correlazione tra arretramento della falesia e ampiezza dell’alto eustatico interglaciale. il problema non è di semplice risoluzione, anche perché è persino controversa la stessa definizione di “interglaciale” (suggate, 1965); non esiste tra l’altro una sovrapposizione precisa tra durata dello stage climatico ed il corrispondente periodo di alto eustatico. pertanto i due argomenti vengono analizzati separatamente. a )durata degli stadi climatici interglaciali le numerose curve delle paleotemperaure basate sugli isotopi dell’ossigeno, ricavate sia da carote oceaniche, sia da carote di ghiaccio che da speleotemi, permettono di osservare le diverse ampiezze delle oscillazioni climatiche e la loro diversa durata. il metodo che sembra più accettabile (in quanto obiettivamente determinabile) è quello di collocare i limiti del periodo interglaciale nel punto intermedio (e ed f in fig. 37-a) tra i valori minimi e massimi del δ18o nei due tratti della curva isotopica che individuano una oscillazione calda 77genesi, età, sollevamento ed erosione ... fig. 36 schema della distribuzione altimetrica dei terrazzi valida per i settori 1 e 2 dell’area esaminata (fig. 1). per il i ordine è stata disegnata la probabile superficie inferiore (si.g.), in quanto i depositi sono stati quasi del tutto erosi. le distanze e le quote delle 4 antiche linee di riva permettono di analizzare i caratteri del loro spostamento verso terra mediante due parametri (cap. 3.9.): 1) gli angoli al vertice a dei 4 triangoli hai, fag, dae e bac risultano rispettivamente di 2,5°, 2,5°, 3° e 2,1°. 2) la velocità di allontanamento (rapporto distanze-età) delle antiche linee di riva del i, ii e iii ordine risulta rispettivamente pari a 1,2 cm/a, 1 cm/a e 1 cm/a. scheme of the altimetric distribution of the terraces, valid for sectors 1 and 2 of the area examined (fig. 1). the probable lower surface (si.g) of the 1st order, of which almost all the deposits have been eroded, has been deduced. the distances and the altitudes of the 4 ancient coastlines (uplifted to altitudes of 210, 105, 65 and 30 m) make it possible to analyse the characteristics of their apparent movement towards the land using two parameters (paragr. 3.9.): 1) the angles (ratio height:distance) to apex a of the 4 triangles hai, fag, dae and bac are 2.5°, 2.5°, 3° and 2.1° respectively; 2) the velocity of distancing (ratio distance:age) of the ancient coastlines of the 1st, 2nd and 3rd orders are 1.2 cm/yr, 1 cm/yr and 1 cm/yr respectively. (shackleton, 1969; winograd et alii, 1997). inoltre è necessario stabilire la differente importanza tra le varie oscillazioni (stages e substages); l’ultimo periodo caldo (il più studiato) è ad esempio caratterizzato da tre picchi a 125.000 (5e), a 105.000 (5c) e a 80.000 (5a) anni circa (muhs et alii, 1994), di cui però solo il 5e è considerato il vero interglaciale (eutirreniano di bonifay & mars, 1959, il cui picco è stato poi collocato da diversi aa. a 125.000 anni fa). la “durata dell’interglaciale 5e” varia, a seconda dei diversi autori, da 130. a 115.000 anni (seidenkratz & knudsen, 1997), da 127. a 112.000 circa (shackleton, 1987), da 128. a 117.000 (martinson et alii, 1987); kukla et alii (1997), comparando i dati climatici ricavati dalla registrazione pollinica della grand pile in francia con i dati climatici delle curve isotopiche dell’ossigeno, concludono che l’ultimo interglaciale (5e) fu due volte più lungo dell’attuale olocene. la durata del 5e è stata quindi di circa 15.-20.000 anni, comprensiva dei due tratti ascendenti e discendenti della curva (fig. 37-a). per quanto riguarda lo stage 7, il periodo climatico è solitamente caratterizzato (come il 5) da 3 picchi differenti (7a, 7c, 7e). non c’è concordanza nella corrispondenza tra picchi citati e interglaciale principale; secondo alcuni aa. il picco più caldo (l’interglaciale) è il 7c (martinson et alii, 1987); secondo altri è il 7e (vincent & berger, 1981; winograd et alii, 1997), mentre in altre curve 7e e 7c appaiono simili (chappell & shackleton, 1986). pertanto nel presente lavoro si è optato di ritenere come interglaciale il 7e, ovvero il primo alto stazionamento capace di generare il terrazzo. la durata di questo interglaciale risulta mediamente di 14.000 anni. secondo winograd et alii (1997), la durata degli ultimi 4 interglaciali è stata di 20.000 anni circa. b) durata degli alti eustatici interglaciali le curve eustatiche possono essere ricavate indirettamente dalle curve isotopiche dell’ossigeno, in base all’equivalenza proposta da shackleton (1987): 0,1‰δ18 = 10 m circa di variazione del livello marino. molti aa. hanno invece ricostruito la storia eustatica in base a numerose e precise datazioni con isotopi dell’uranio effettuate allo spettrometro di massa, utilizzando in particolare i coralli dei terrazzi recifali (chappell & veeh, 1978; hoang & hearty (1989); ku et alii (1990); mush et alii (1994). occorre sottolineare che in questi casi viene datato il periodo di “alto eustatico”, compreso tra il tratto trasgressivo della curva e quello regressivo. non c’è quindi una corrispondenza precisa con il periodo climatico interglaciale così come è stato definito al punto (a) precedente. secondo smart & richards (1992) il 5e è stato un evento complesso durato ben 12.000 anni; chen et alii (1991) precisano che il periodo di alto livello marino (compreso tra trasgressione e regressione) è 78 l. carobene fig. 37 rapporti tra periodi interglaciali (a) e alti livelli eustatici interglaciali (b). aa) curva di una ipotetica oscillazione climatica calda. e ed f: punti intermedi dei tratti ab e cd. e’f’: durata dello stadio climatico interglaciale (es. stage 5e). m.= massimo interglaciale. bb) curva eustatica schematica. tempi: ab= periodo della curva con alta velocità di risalita del mare; bc= periodo della curva in cui diminuisce la velocità di risalita; ce= periodo completo dell’alto eustatico interglaciale; cd= semiampiezza dell’alto eustatico; ef= periodo regressivo della curva eustatica, che pone termine all’alto eustatico. livelli del mare: t.= tratto trasgressivo della curva eustatica in cui inizia a formarsi la superficie inferiore di erosione del terrazzo e si depositano i “sistemi deposizionali trasgressivi”; a.e.= tratto della curva corrispondente al periodo di “alto eustatico interglaciale” durante il quale si completa la superficie inferiore di erosione del terrazzo e si depositano i “sistemi deposizionali di stazionamento alto”. r.= tratto regressivo della curva che porta ad un nuovo periodo di basso eustatico. p = profondità alla quale inizia la deposizione del corpo terrazzato sulla superficie inferiore del terrazzo; si ricava conoscendo la posizione dello stazionamento marino più alto. the relationship between interglacial periods (a) and high interglacial eustatic levels (b). aa) curve of a hypothetical warm climatic oscillation. e and f: midpoints of the tracts ab and cd; the points a and f on curve b correspond to these. e’f’: duration of the interglacial climatic stage (e.g. stage 5e). m = interglacial maximum. bb) schematic eustatic curve. times: ab = period of the curve with high sea rise velocity; ce = entire period of the interglacial eustatic peak; cd = semiamplitude of the eustatic high; ef regressive period of the eustatic curve, which closes the eustatic peak. sea level: t. = transgressive tract of the eustatic curve during which the lower erosion surfaces of the terrace began to form and the “transgressive systems tract” deposited; a.e. = tract of the curve corresponding to the period of the “interglacial eustatic peak”, during which the lower erosion surface of the terrace was completed and the “highstand systems tract” deposited. r. = regressive tract of the curve leading to a new low eustatic period. durato da 132. a 120.000 anni; una recente rassegna di dati è stata fatta da stirling et alii (1995), i quali concludono che il picco eustatico interglaciale è compreso tra 130. e 117.000 anni fa; secondo israelson & wohlfarth (1999) in questo intervallo di tempo (tra 130. e 117.000 anni) il livello del mare è rimasto superiore all’attuale; per shackleton (1987 – fig. 5) l’alto eustatico è compreso tra 115. e 125.000 anni circa. hearty & dai pra (1992) riportano per l’italia (toscana, lazio, puglia e calabria) datazioni radiometiche comprese tra 135. e 118.000 anni fa. hearty (2002), sulla base di una revisione della stratigrafia dei depositi interglaciali affioranti a bermuda, evidenzia due alti picchi eustatici riferibili al substage 5e, compresi in un intervallo tra 115. e 135.000 anni circa. molti altri aa. forniscono per l’ultimo interglaciale solamente un dato cronologico centrato su 125.000 anni fa, senza fornire i limiti precisi del periodo di alto stazionamento, che comunque appare compreso tra 130. e 120.000 anni (murray-wallace & belperio, 1991). mediando i valori forniti dai vari aa., si può ritenere che quest’ultimo intervallo di tempo corrisponda alla durata dell’alto picco eustatico interglaciale riferibile al substage 5e (intervallo di tempo c-e in fig. 37 – b); esso non comprende tuttavia il periodo trasgressivo della curva eustatica (intervallo di tempo b-c in fig. 37b) che, invece, ha contribuito alla formazione del tratto rettilineo (si.tr. in fig. 31) della superficie inferiore del terrazzo del iii ordine e al corrispondente deposito trasgressivo (insieme di sistemi trasgressivi tst in fig. 33). per quanto riguarda invece l’interglaciale 7e, i dati riferiti alla durata dell’alto picco eustatico sono scarsi, mentre è ben documentata la data media, posta a circa 240.000 anni (chappell & shackleton, 1986). si possono in questo caso utilizzare conclusioni analoghe a quelle esposte sopra per il 5e. la durata effettiva dell’alto livello di un’intera oscillazione eustatica interglaciale (curva b in fig. 37) è discussa in winograd et alii (1997), prendendo come riferimento la curva di risalita del livello del mare successiva all’ultimo glaciale würmiano (in bard et alii, 1996). poiché la risalita del mare di circa 120 m avviene nell’arco di 14.000 anni (da 19.000 a 5.000 anni fa circa), il “punto intermedio” (corrispondente al punto a o al punto f in fig. 37-b) viene a cadere 12.000 anni fa (7.000+5.000). l’attuale alto eustatico è tuttavia ancora in atto, per cui la durata totale della oscillazione eustatica (tratto a-f in fig. 37-b, corrispondente al tratto e’-f’ di fig. 37-a) sarà sicuramente maggiore di 12.000 anni. c) correlazione tra formazione del corpo terrazzato e la durata dell’alto eustatico interglaciale al precedente paragr. 3.5. si è dimostrato come il consistente spessore che caratterizza i depositi del ii ordine (fino a 45 m) e del iii ordine (fino a 25 m) può essere agevolmente riferibile, in base alle litofacies descritte (v. 3.4.), ad un “insieme di sistemi deposizionali trasgressivi” (tst) e ad un “insieme di sistemi deposizionali di stazionamento alto” (hst) (fig. 33). all’evento eustatico che li ha prodotti deve corrispondere anche la formazione della superficie inferiore dei terrazzi; essa consiste in un tratto rettilineo a bassa pendenza (0,5-1°) e in un tratto curvo a pendenza maggiore (6-8°) (fig. 31). questo modello mostra (come già accennato in 3.1.) grandi analogie con quello descritto nella california centrale da bradley & griggs (1976), dove i due tratti vengono chiamati rispettivamente “flatter, planar offshore segment” (0,4-1°) e “steeper, slightly concave inshore segment” (1,2-2,3°). detti aa. propongono un modello tettonico-eustatico interpretativo per cui la piattaforma di erosione inizia a formarsi in un determinato stadio della curva trasgressiva (sea level rising slowly; eustatic rise slightly exceeds uplift), per completarsi in uno stadio successivo (sea level constant; eustatic rise balances uplift). a questo modello può adattarsi anche la formazione dei terrazzi studiati in destra del f. trionto. sicuramente non ha contribuito alla loro formazione la parte regressiva dell’alto eustatico; anzi, poiché il deposito del terrazzo appare progradante ma contemporaneamente aggradante (figg. 6 e 14), è certo che gran parte (almeno ciò che oggi appare visibile) del corpo terrazzato riferito all’alto stazionamento si è formato in realtà in un regime di leggero sollevamento eustatico che sopravanzava il sollevamento tettonico (risultato pari a 0,5 mm/a – vedi 3.12.). pertanto si può concludere che la formazione dei corpi terrazzati (che hanno carattere progradante sia per il ii che per il iii ordine) occupa solo una parte dello “stadio climatico interglaciale” e della corrispondente “curva eustatica”; in termini di tempo la formazione dei depositi terrazzati è avvenuta durante la prima semiampiezza della oscillazione eustatica (tratto a-d in fig. 37-b), la cui durata non dovrebbe superare i 10.000 anni in base ai punti a) e b) sopra esposti. più in particolare, l’inizio di formazione della superficie inferiore del terrazzo è avvenuto in un punto del tratto trasgressivo della curva eustatica corrispondente ad una (paleo)profondità di valore non superiore al massimo spessore del deposito terrazzato marino riconosciuto. per il ii e per il iii ordine tale profondità (p in fig. 37-b) corrisponde rispettivamente a 45 ed a 25 m. d) correlazione tra velocità di arretramento delle falesie e l’ampiezza dell’alto eustatico interglaciale quanto espresso in e) ci permette di correlare i tempi di formazione dell’intera superficie inferiore di erosione dei terrazzi studiati a quelli di formazione dei depositi terrazzati. con riferimento alle sezioni geologiche delle figure 6, 14 e 20, sono stati calcolati gli spessori medi dei corpi trasgressivi e di alto stazionamento (corrispondenti rispettivamente a tst ed a hst di fig. 33), sia per i terrazzi del ii che del iii ordine. questi valori sono stati considerati equivalenti ai sollevamenti eustatici (riga 3 in tab.2), sia totali che parziali. pertanto lo spessore del corpo trasgressivo diventa equivalente all’innalzamento eustatico responsabile della formazione dl “tratto rettilineo” della superficie inferiore, mentre lo spessore del deposito di alto stazionamento eustatico diventa equivalente all’innalzamento eustatico responsabile della formazione del”tratto concavo” della superficie inferiore. in particolare il corpo trasgressivo si è formato in corrispondenza di un sollevamento marino pari a 7-10 m per lo stage 5e e pari a 15-20 m per lo stage 7e (tratto t. di fig. 37-b); il corpo relativo all’alto eustatico si è invece formato durante un sollevamento del livello marino di circa 15 m per lo stage 5e e di 20-25 m per lo stage 7e (tratto a.e. di fig. 37-b). 79genesi, età, sollevamento ed erosione ... correlazioni per il iii ordine. per dare un significato temporale ai sollevamenti eustatici t. e a.e. si possono utilizzare come modello le curve di risalita del mare postglaciale, di cui una raccolta è riportata in pirazzoli (1991). dopo le tre fluttuazioni fredde del dryas, il mare inizia a risalire decisamente a partire da circa 11.600 anni (kovanen & easterbrook, 2002); per ritrovare la quota di –25 m (valore pari all’innalzamento eustatico riscontrato nel terrazzo del iii ordine) occorre risalire a circa 8.000-9.000 anni fa (curve utilizzate per i calcoli in bard et alii, 1989 e in bard et alii, 1996), tempo coerente con i tempi ricavati in c). pertanto, per quanto riguarda il terrazzo del iii ordine (stage 5e), l’arretramento delle falesie in argilla (che ha determinato la formazione di una superficie di erosione ampia 775 m) è avvenuto in un lasso di tempo simile, con una velocità media di 9 cm/anno (riferita al profilo b di fig. 14). (tutti i dati numerici delle ampiezze, dei tempi e delle velocità medie sono riassunti in tab. 2). si può inoltre scindere tale valore medio, distinguendo il tratto trasgressivo (t.) della curva da quello relativo allo stazionamento (a.e.) (picco eustatico interglaciale in fig. 37-b): durante il primo tratto il mare si è innalzato (come riportato sopra) di circa 10 m. sempre con riferimento alle curve di bard et alii (1989 e 1996) ciò si è verificato in circa 1.200-2.000 anni, periodo al quale corrisponde una velocità di arretramento della falesia che, riferita al solo tratto rettilineo della superficie inferiore (si.tr.) è pari a 38 cm/anno. tale valore è coerente con quelli citati da anderson et alii (1999) per i terrazzi di santa cruz in california (“….several tens of centimetres per year”). il rimanente tratto concavo (si.tc.) della superficie inferiore si forma successivamente nell’arco dei rimanenti 6.900 anni, quindi con una velocità media di arretramento della falesia pari a 2,5 cm/anno circa. la forte differenza tra i due valori ritrovati trova piena corrispondenza e giustificazione nel modello barriera-laguna invocato per spiegare la stratigrafia dei deposit i terrazzati (v. 3.5.). infatti, durante la fase di progradazione della spiaggia (highstand systems tract), la falesia si è formata all’interno di bacini lagunari o dulcicoli, riparata dall’azione diretta del mare aperto. correlazioni per il ii ordine. per quanto riguarda il terrazzo del ii ordine (stage 7e), le deduzioni che si possono trarre sono analoghe, anche se l’innalzamento del mare durante le fasi t. e a.e. (fig. 37-b) è stato complessivamente di ben 45 m (vedi tab. 2). utilizzando per il calcolo la fig. 6-profilo a, si ricava una lunghezza di 1100 m per l’intera superficie inferiore di erosione; dalle curve di bard et alii (1989 e 1996) si calcola l’intervallo di tempo di 10.200-10.400 anni circa (comprensivo dei tratti t. e a.e.), per cui la velocità media di arretramento della falesia risulta di 11 cm/anno. per il tratto rettilineo (corrispondente al sollevamento eustatico di 20 m circa), la velocità di arretramento risulta dai calcoli pari a 34 cm/a. per quanto i dati di velocità sopra ricavati (e riportati in tab. 2) dipendano da troppe variabili, e in particolare da una non precisa conoscenza delle curve eustatiche e degli effetti della tettonica, tuttavia essi forniscono per la prima volta un ordine di grandezza di arretramento delle falesie argillose, che sarebbe interessante confrontare con i valori attuali delle coste calabresi. un dato a disposizione riguarda il promontorio di capo colonna (crotone, calabria ionica), dove cocco et alii (1993) segnalano un arretramento medio della falesia argillosa attuale, e del sovrastante corpo terrazzato marino, di circa 1 m/a a partire dal 1880; d’alessandro et alii (2001) ricavano inoltre valori di arretramento compresi tra 28 e 92 cm/a lungo falesie argilloso-sabbiose 80 l. carobene tteerrrraazzzzoo iiiiii oorrddiinnee ampiezza tratto tratto totale rettilineo concavo1 (b in fig. 14) si.tc.+si.tr. si.tr. si.tc. 2 superficie inferiore (metri) 775 600 175 3 sollevamento eustat. (metri) 25 10 15 4 tempi di formazione (anni) 8500 1600 6900 velocità di arretramento 5 vv..aarr.. 99 3388 22,,55 (cm/anno) tteerrrraazzzzoo iiii oorrddiinnee ampiezza tratto tratto totale rettilineo concavo1 (a in fig.6 e 14) si.tc.+si.tr. si.tr. si.tc. 2 superficie inferiore (metri) 1100 650 450 3 sollevamento eustat. (metri) 45 20 25 4 tempi di formazione (anni) 10300 1900 8400 velocità di arretramento 5 vv..aarr.. 1111 3344 55,,44 (cm/anno) tab. 2 la velocità di arretramento delle paleofalesie argillose del ii e del iii ordine di terrazzi (riga 5) è stata calcolata tenendo conto della durata degli alti livelli eustatici interglaciali (riga 4); dello spessore dei depositi terrazzati e quindi dei corrispondenti sollevamenti eustatici (riga 3); dell’ampiezza delle superfici inferiori dei terrazzi (riga 2). the velocity of the retreat of the ancient clayey cliffs of the terraces of the 2nd and 3rd orders (line 5). line 1: see symbols in fig. 31. line 2: width of the lower surface of the terraces. line 3: eustatic uplift, corresponding to the disparity between the height of the external limit of the terraced deposit (le.d.) and the paleoshoreline (plr.g) (symbols in fig. 31). line 4: times for the formation of the lower surfaces and the terraced bodies of the transgressive phases (t.) and the eustatic highstands (a.e.) (symbols in fig. 37-b). dell’abruzzo; il periodo esaminato va dal 1876 al 1985. sunamura (1992) riporta una serie di dati sui tassi di erosione delle falesie lungo le coste di tutto il mondo (appendix 2); una media di 27 valori riferiti a depositi diagenizzati argillosi e siltosi (mudstone, siltstone e claystone) risulta pari a 46 cm/anno, valore vicino a quelli ricavati per il tratto trasgressivo della superficie inferiore dei terrazzi marini del ii e del iii ordine in destra del f. trionto (tab. 2). 33..1111.. ssiiggnniiffiiccaattoo ddii ““aallttoo eeuussttaattiiccoo iinntteerrggllaacciiaallee”” ee ddii ““aallttoo lliivveelllloo ddii ssttaazziioonnaammeennttoo ddeell mmaarree”” i risultati emersi dallo studio dei terrazzi in destra del f. trionto permettono di effettuare anche qualche considerazione di carattere generale. normalmente, dallo studio morfologico di un terrazzo, o di un deposito terrazzato marino, o di altri indizi di antichi livelli marini sollevati, si deduce un unico alto livello di stazionamento del mare il quale, a sua volta, viene associato ad un picco eustatico interglaciale. questa (imprecisa) correlazione nasce da due motivi principali: 1) lo studio morfologico di un terrazzo e dei suoi depositi difficilmente fornisce gli elementi per riconoscere più di un antico livello marino; nella maggior parte dei casi vale la corrispondenza margine interno=antico livello marino. 2) gli alti livelli di stazionamento del mare vengono considerati interglaciali e quindi collegati ai corrispondenti periodi caldi interglaciali delle curve climatiche (generalmente ricavate dallo studio degli isotopi dell’ossigeno su carote oceaniche): in tali curve paleoclimatiche il periodo interglaciale corrisponde solitamente ad un unico picco caldo datato. quanto esposto al paragr. 3.6. ha evidenziato invece la genesi polifasica di un terrazzo, ad opera di un certo numero di stazionamenti del mare succedutisi a quote non molto differenti. in effetti un numero sempre maggiore di curve isotopiche più recenti mostra con miglior dettaglio l’andamento del periodo caldo interglaciale, che si presenta a volte suddiviso in 2-3 picchi (seidenkratz & knudsen, 1997; shackleton, 1987). carobene & pasini (1982), in base allo studio delle grotte marine del golfo di orosei, hanno ricavato una curva eustatica del tirreniano (riss-würm) caratterizzata da almeno 5 alti livelli di stazionamento del mare. hearty (1987 e 2002) segnala almeno due “livelli marini” distinti durante l’ultimo interglaciale 5e rispettivamente nelle isole di maiorca e di bermuda. inoltre carobene & ferrini (1993) hanno proposto un modello genetico del grande terrazzo del m. carpinoso (costa tirrenica della calabria) che prevede l’azione di numerosi alti livelli appartenenti a interglaciali differenti (genesi policiclica). la formazione di un terrazzo polifasico (composito) richiede un lungo lasso di tempo che è ben compatibile con l’intero periodo caldo interglaciale. a questo periodo di formazione del terrazzo corrisponde pertanto l’intero “alto eustatico interglaciale”. cosa diversa sono invece le singole oscillazioni climatiche nelle quali si articola un periodo interglaciale: ad ognuna di esse può corrispondere un singolo “alto livello di stazionamento marino” (tab. 3). i singoli alti livelli di stazionamento marino sono stati riconosciuti nel presente lavoro in base ai periodi regressivi (emersione, formazione di suoli) e in base ai periodi trasgressivi (orizzonti di depositi di battigia) documentati entro le peliti di retrospiaggia. generalizzando, è possibile concludere che ogni singolo terrazzo marino (del tipo di quelli studiati in destra trionto) costituisce la risposta morfologica e sedimentaria a diversi “alti livelli di stazionamento marino” verificatisi nell’ambito di un “periodo di picco eustatico interglaciale”. un terrazzo viene tuttavia identificato (anche nel presente lavoro) con un’unica linea di riva; questa corrisponde allo stazionamento marino più alto riconosciuto. 33..1122.. iill ccoonnttrroolllloo ddeellllaa tteettttoonniiccaa un altro risultato a carattere generale, emerso dallo studio dei terrazzi, riguarda la tettonica; i suoi effetti si sono manifestati: a)con il sollevamento, b)con un controllo sulla evoluzione delle paleofalesie e c)sul condizionamento operato dalle faglie nella fase di rimodellamento dei terrazzi sollevati. il tasso di sollevamento piuttosto alto, pari a 0,50 mm/a (vedi 3.2.), ha permesso una buona separazione altimetrica dei terrazzi, sufficiente alla conservazione dei vari ordini. una eccezione potrebbe essere il terrazzo del i ordine, in quanto è verosimilmente il risultato della somma di due interglaciali, corrispondenti agli stages climatici 9 e 11 (vedi 3.2. e 3.9.). stesso discorso può valere per il terrazzo del iv ordine, attribuibile ai substages 5a o 5c, o a entrambi. 81genesi, età, sollevamento ed erosione ... alti livelli del mare: caratteri e corrispondenze singola linea di riva 1) alto livello di stazionamento marino tipologia semplice (es. solco, trottoir) (singolo livello) altimetricamente ben definita da una singola quota tempo di formazione breve fossili e depositi intertidali associazione di linee di riva 2) alto picco eustatico interglaciale tipologia complessa (es. terrazzo marino) (più livelli di stazionamento) altimetricamente definita in un intervallo di quote tempo di formazione lungo fossili e depositi di spiaggia da emersa a sottomarina tab. 3 le ricerche nell’area crosia-calopezzati hanno evidenziato come un terrazzo marino derivi da una associazione di “alti stazionamenti” del livello del mare, succedutisi durante un “alto eustatico interglaciale”. la tabella riporta sinteticamente i principali caratteri distintivi di questi due termini, spesso usati come sinonimi. high sea levels. the research in the crosia-calopezzati area has highlighted how a marine terrace derived from an association of “sea highstands” progresses during a “high interglacial eustatic peack”. the table synthetically presents the principal distinctive characteristics of these two terms that are so often used as synonyms. 1) sea level highstand. single shoreline characterised by: -simple typology; la tettonica pre-formazione dei terrazzi è riconoscibile dallo studio stratigrafico del substrato: ne ha condizionato la giacitura, il sollevamento, le dislocazioni. l’assetto del corpo pleistocenico ha a sua volta influito sull’impostazione e sull’evoluzione delle paleofalesie; una prova può essere la direzione delle due rette che uniscono i margini interni dei terrazzi nei settori 1 e 2 (tra il f. trionto e il t. fiumarella), che è uguale a 123° (ono-ese) sia per il ii che per il iii ordine. tale direzione (120-125°) è ben documentata al confine calabro82 l. carobene fig. 38 andamenti delle faglie e topografia semplificata del tratto di costa crosia-calopezzati; sono indicate le quote delle culminazioni topografiche e dei punti quotati citati nel testo e nelle figure. 1) principali sistemi di faglie quaternarie ricavate in base allo studio del substrato e degli indizi morfologici (valori medi delle direzioni: 26°, 40°, 60°, 120°, 140°). 2) traccia delle sezioni geologiche dei terrazzi: a-a’= settore 1; b-b’= settore 2; c-c’= settore interno; d-d’= settore 3. le sezioni sono riportate rispettivamente nelle figure 2 e 6; 14; 25; 20. trends of the faults and simplified topography of the crosia-calopezzati coastal tract; the altitudes of the topographic culminations and the points cited in the text and the figures are indicated. 1) principal quaternary fault systems, deduced from the study of the substratum and the morphological clues (mean values of directions: 26°, 40°, 60°, 120°, 140°). 2) line of the geological sections of the terraces: a-a’ = sector 1 (fig. 2 and fig. 6): b-b’ = sector 2 (fig. 14); c-c’ = internal sector (fig. 25); d-d’ = sector 3 (fig. 20). lucano, (catalano et alii, 1993; cucci & cinti, 1998; marra, 1999; patacca & scandone, 1989; turco et alii, 1990); essa coincide anche con quella allineata lungo il confine che separa i terreni del miocene (tortoniano) e del pliocene inferiore da quelli quaternari lungo il tratto di costa tra crosia e cariati. secondo questa direzione è separata l’area marina subsidente a ne da quella emersa in sollevamento a so. nel 3° settore invece le superfici terrazzate del ii ordine sono troncate a monte da selle allineate in direzione 142° (paragr. 2.2.3.), direzione che corrisponde ad una famiglia di lineamenti (138-142°) che interessa una vasta fascia costiera a se del t. fiumarella; essa si evidenzia in particolare dal pattern del drenaggio. gli effetti delle faglie (o fratture) sul rimodellamento dei terrazzi (vedi 3.13.) si manifestano con il frazionamento delle originarie superfici in relitti allungati nella direzione delle faglie o separati da selle allineate tra loro (fig. 1); le direttrici più evidenti nel 1° e 2° settore hanno direzione di 38-42° e 117-123°; nel 3° settore invece i lineamenti con effetti morfologici palesi sulle superfici terrazzate hanno direzione 24-29°, 38° e 140-142° (angoli misurati in senso orario) (fig. 38). il riconoscimento di lineamenti tettonici raggruppabili in famiglie ben precise a 26°, 40°, 60°, 120° e 140° (valori medi) permette forse di riferirli ad una deformazione legata a tettonica trascorrente, per analogia con i modelli proposti da catalano et al i i (1993) e da marra (1999) per la zona calabro-lucana immediatamente a nord. nell’area di tarsia (valle del crati), lo studio del substrato quaternario ha evidenziato la presenza di due importanti sistemi di faglie, a 40° e a 136° (valori medi) (carobene et alii, 1997). 33..1133.. iill rriimmooddeellllaammeennttoo,, ll’’eerroossiioo-nnee ee llaa ttrraassffoorrmmaazziioonnee ddeell ppaaee-ssaaggggiioo ccoossttiieerroo nneell tteemmppoo le osservazioni effettuate nell’area crosia-calopezzati hanno evidenziato il forte rimodellamento subìto dai terrazzi; il processo erosivo ha trasformato il paesaggio originario dando origine ad una serie di relitti delle antiche forme e degli antichi depositi terrazzati (vedi 3.1. e fig. 31). i relitti del iii ordine sono ancora rappresentati da singoli ripiani suborizzontali, testimoni della originaria superficie terrazzata (fig. 39), mentre i relitti degli ordini superiori (quindi più antichi), sono via via sempre più ridotti arealmente fino a diventare rilievi isolati di forma convessa (fig. 40). inoltre la forma in pianta dei relitti e la loro distribuzione lungo la costa appare nettamente condizionata da sistemi di faglie o fratture, confermate dallo studio stratigrafico del substrato (fig. 1). la fig. 41 schematizza la forma tridimensionale di un terrazzo, evidenziando 4 tipi di superfici sulle quali agiscono 4 gruppi di processi differenti (p1-p2-p3-p4 in f igura) responsabil i , nel tempo, del rimodellamento e quindi della progressiva trasformazione e distruzione della superficie terrazzata. le 4 83genesi, età, sollevamento ed erosione ... fig. 39 terrazzo del iii ordine; settore 2°. i relitti di questi terrazzi conservano ancora tratti della superficie superiore (ss.r.) di forma piana e regolare, leggermente inclinata verso mare. terrace of 3rd order; sector 2. the relics of these terraces still preserve tracts of the upper surface (ss.r.) of flat and regular form, slightly inclined towards the sea. fig. 40 terrazzo del ii ordine; 1° settore. la superficie superiore (ss.r.) si presenta ondulata e raramente conserva tratti piani. il crinale è visto da se. terrace of 2nd order; sector 1. the upper surface (ss.r.) is undulated and only rarely preserves flat tracts. the ridge is seen from the se. 84 l. carobene superfici sono: a) la paleofalesia; b) la superficie superiore del terrazzo; c) la falesia attiva; d) il versante vallivo. in fig. 41 sono inoltre evidenziati i processi (p5) che agiscono sui fondovalle (fv.) ed i processi (p6) che avvengono lungo la fascia costiera (fc.). fermi restando gli elementi primari della trasformazione (clima, tempo, tettonica, eustatismo), i fattori che hanno condizionato l’erosione sono stati certamente: tipo di substrato; tipo di deposito terrazzato e suo spessore; copertura vegetale, anche erbacea; tasso di sollevamento dell’area (s.c.); caratteristiche dei fondali marini antistanti e del moto ondoso. con riferimento all’area di studio, le osservazioni sulle superfici sopra citate sono le seguenti: 1) la paleofalesia (pf.) la forte inclinazione originaria (angolo α1) della falesia argillosa si riduce progressivamente nel tempo (angolo α2) sotto l’azione di processi (p1 in figura) di dilavamento areali, favoriti dall’alternanza di periodi secchi e piovosi; per fenomeni di soliflusso e di ruscellamento diffuso. la discesa di materiale verso il basso porta a creare un deposito colluviale (c.) al piede, che va a coprire e a proteggere la zona del margine interno del terrazzo. attualmente l’inclinazione media delle paleofalesie è minore di 20° tra il iv ed il iii ordine di terrazzi ed è minore di 15° tra il iii ed il ii ordine, mentre la paleofalesia del i ordine è inclinata di circa 9° (paragr. 2.1.a). 2) la superficie superiore del terrazzo (ss.) sulla base delle ricostruzioni geometriche, l’inclinazione originaria delle superfici superiori non superava i 2°; pertanto era debole lo scorrimento superficiale dell’acqua, mentre era forte l’infiltrazione. ciò ha favorito il processo dell’alterazione e della pedogenesi dei depositi terrazzati (processi p2 in figura). il ruolo delle fratture o delle faglie è stato importante, in quanto lungo di esse si sono formati inizialmente solchi di ruscellamento e, progressivamente, vere e proprie incisioni che si sono approfondite lentamente nel corpo terrazzato fino a raggiungere il substrato argilloso. a quel punto lo sviluppo dell’incisione ha subìto una forte accelerazione; tutta la morfologia dei terrazzi del ii ordine (in particolare) è condizionata da questo fenomeno (fig. 1 e cap. 2.). per gli effetti della tettonica si rimanda anche al paragr. 3.12. 3) la falesia attiva (fa.) non esistono attualmente falesie attive lungo il tratto di costa esaminato. un rilevamento dei terrazzi lungo tutta la costa ionica fino a locri (ricerca non pubblicata), ha tuttavia evidenziato numerosi casi di falesie attive in argilla; esse mostrano sempre una forte inclinazione, vicina alla verticale (fig. 32). l’erosione al piede della falesia produce un suo rapido arretramento frontale (a.f.) che avviene mediante crolli (processi p3 in figura 41). 4) il versante vallivo (vv.) i versanti costituiscono le superfici più estese del paesaggio, sede di intensi processi erosivi (p4 in figura). l’erosione lineare si manifesta con solchi di ruscellamento e con profonde incisioni torrentizie causate dagli affluenti del corso principale; l’erosione areale con fenomeni franosi e colate di fango. molto importanti sono inoltre le pratiche agricole, che favoriscono il forte dilavamento sui terreni arati. tutto ciò tende a produrre una diminuzione dell’inclinazione (g) del versante e 85 fig. 41 rappresentazione schematica degli elementi morfologici (superfici pf., ss., fa. e v.v.) che compongono e definiscono un terrazzo marino sollevato; su ciascuna superficie agiscono differenti gruppi di processi (p1, p2, p3 e p4) che determinano gli effetti erosivi (indicati dalle frecce); essi portano al rimodellamento del terrazzo e, in tempi lunghi, alla sua distruzione. a questo rimodellamento contribuiscono indirettamente anche i processi indotti da agenti esterni alle 4 superfici sopra citate: i processi (p5) di fondovalle che agiscono anche alla base del versante vallivo e sono causati dall’azione dei corsi d’acqua, ed i processi (p6) che si attuano lungo la fascia costiera; essi sono causati dai movimenti del mare ed agiscono alla base della falesia attiva, oltre che sul fondo marino. i due motori principali del sistema morfogenetico sono le oscillazioni eustatiche (o.e.) ed il sollevamento tettonico della costa (s.t.) che, come effetto diretto principale, producono le variazioni del livello di base. i processi sono condizionati da fattori che variano da zona a zona. gli angoli α definiscono le inclinazioni delle falesie (antiche e attuali); γ indica l’inclinazione media del fondovalle; δ l’inclinazione media dei versanti vallivi. nella figura la superficie superiore (ss.) è stata disegnata (per semplicità) orizzontale; l’angolo β indica la sua eventuale inclinazione media (vedi fig. 31). schematic representation of the morphological elements (surfaces pf., ss., fa. and v.v.) that define an uplifted marine terrace and play a role in its evolution; different groups of processes (p1, p2, p3 and p4) act on each surface and determine the erosive effects (indicated by the arrows); these cause the remodelling of the terrace and, over long periods, its destruction. this remodelling is also indirectly influenced by valley bottom processes (p5), caused by the action of watercourses that also act on the base of the valley slopes and processes acting along the coastal tract (p6), which are caused by sea movements and affect the base of the active cliffs and the sea floor. the two principal motors of the morphogenetic system are the eustatic oscillations (o.e.) and the tectonic uplifting of the coast (s.t.) whose principal direct effect is the creation of variations in the base level. these processes are conditioned by factors that vary from zone to zone. the angles α define the inclination of the cliffs (ancient and present day); γ indicates the mean inclination of the valley bottom; δ the mean inclination of the valley slopes. in the figure the upper surface (ss.) has been drawn horizontally for simplicity; the angle β indicates its eventual mean inclination (fig. 31). pf. = paleoseacliff. p1 causes a diminution in the original inclination (from 1 to 2). ss. = upper surface of the terrace. p2 produces alterations and linear erosion. fa. = active cliff. p3 and p6 erode the foot of the cliff producing falls and subaerial erosion, with movement of the cliff from 1 to 2. v.v. = valley slope. the processes produce landslides, ravines, washouts and watercourses, with progressive lateral retreat of the slope. ➧ genesi, età, sollevamento ed erosione ... quindi un arretramento laterale (a.l.) della superficie del terrazzo. i versanti solitamente presentano una duplice inclinazione: maggiore nella parte alta in corrispondenza del corpo terrazzato, minore in basso in corrispondenza del substrato argilloso (fig. 15). e) il fondovalle (fv.) i corsi d’acqua che tagliano trasversalmente lo sviluppo lungo costa dei terrazzi presentano generalmente nella zona a monte una forma valliva a v in fase di incisione e, a valle, una piana alluvionale caratterizzata da regimi fluviali estremi, con alternanze cioè di periodi secchi con altri a rapido e forte alluvionamento. i fondovalle sono quindi interessati da processi (p5) che producono incisione (con approfondimento dell’alveo); alluvionamento, con eventuale erosione al piede dei versanti; spostamenti laterali dell’alveo che attualmente, nella parte a valle, incide quasi sempre per alcuni metri il deposito alluvionale. f) la fascia costiera (fc.) la figura 41 mostra un livello mare che batte direttamente sulla costa emersa, producendo una falesia attiva (fa.); i processi (p6) sono in questo caso di scalzamento al piede della falesia con asporto di materiale, trasporto di detriti lungo costa, azione di erosione e di abrasione del fondale. attualmente (nell’area studiata), tra i rilievi ed il mare, si interpone una fascia costiera emersa ed una spiaggia ghiaioso-sabbiosa. 44.. ccoonncclluussiioonnii le ricerche condotte nell’area crosia-calopezzati, in destra del f. trionto, hanno fornito nuovi contributi alla conoscenza di genesi e sviluppo dei terrazzi marini. i dati raccolti hanno permesso di perfezionare lo studio quantitativo dei terrazzi, con la proposta di nuovi schemi riguardanti forma, geometria e nomenclatura degli stessi. la genesi dei terrazzi è stata inoltre rapportata alle curve climatiche ed eustatiche relative ai periodi interglaciali, grazie anche alla presenza di depositi terrazzati complessi. infine sono emersi nuovi dati sulla tettonica tardo-quaternaria; è stato perfezionato infine il quadro dei processi erosivi che, con il sollevamento, hanno rimodellato le antiche superfici terrazzate. una sintesi delle considerazioni espresse nel cap. 3 è la seguente: 1) viene proposta una dettagliata nomenclatura per descrivere sia le caratteristiche genetiche, geometriche e morfologiche dei terrazzi, sia quelle derivanti dal loro rimodellamento, soprattutto in presenza di un corpo terrazzato di un certo spessore (schema in fig. 31). 2) ll’’eettàà assegnata ad ogni singolo ordine di terrazzi è stata stabilita attribuendo le linee di riva più alte alle oscillazioni climatiche più calde delle curve isotopiche dell’ossigeno (mis); tenendo conto dell’età del substrato; considerando le velocità di sollevamento dei terrazzi nelle aree limitrofe. la cronologia dei 4 ordini di terrazzi presenti nell’area (fig. 36) è la seguente: i ordine (+ 210 m) = stages 9+11; ii ordine (+105÷120 m) = stage 7e; iii ordine (+64÷71 m) = stage 5e; iv ordine (+25÷30 m) = substages 5a5c. ii ttaassssii ddii ssoolllleevvaammeennttoo risultano pari a 0,50 mm/a circa. 3) nel processo trasgressivo ha giocato un ruolo determinante iill ssuubbssttrraattoo che, nell’area studiata, è costituito da argille siltose del pleistocene inferioremedio. la litologia del substrato ha condizionato la formazione ed il veloce arretramento delle falesie (vedi 3.10.); ha inoltre favorito la formazione di una “piattaforma marina di erosione” (più che di abrasione). 4) i depositi terrazzati presentano litologie diversificate; è stato così possibile distinguere 99 lliittooffaacciieess, correlate ai vari ambienti di spiaggia. esse sono (figure 6, 14, 20 e 25): (cb) conglomerato basale trasgressivo; (pm) peliti marine; (si) sabbie grigie inferiori; (ags) alternanze ghiaioso-sabbiose; (ss) sabbie gialle superiori; (pds) peliti dulcicole, salmastre, lagunari; (ca-ab-cc) calcari arenacei-arenarie bioturbate-calcari conchigliari; (ca) calcari algali; (cc) conglomerati continentali. 5) il consistente spessore che caratterizza i depositi del ii ordine di terrazzi (fino a 45 m) e del iii ordine (fino a 25 m), e la loro suddivisione in litofacies distinte, che individuano corpi sedimentari tra loro in eteropia di facies, permette di riconoscere agevolmente (per entrambi gli ordini) dduuee sseeqquueennzzee ddeeppoo-ssiizziioonnaallii iinnddiiccaattiivvee ddii uunn ssiisstteemmaa ccoossttiieerroo bbaarrrriieerraa-llaagguunnaa. sono riconoscibili infatti un “insieme di sistemi deposizionali trasgressivi” (tst) e un “insieme di sistemi deposizionali di stazionamento alto” (hst), divisi da una “superficie di massima ingressione” (mfs) (fig. 33). il sistema deposizionale regressivo è stato probabilmente distrutto dalla genesi dei terrazzi più recenti. il deposito hst si è formato con forte progradazione del cordone di spiaggia, accompagnato da aggradazione; ciò ha determinato lo sviluppo di ampi bacini lagunari o dulcicoli di retrobarriera. 6) l’analisi stratigrafica delle successioni pelitiche (pds) caratteristiche dei bacini di retrobarriera sopra citati, ha evidenziato periodi di emersione (paleosuoli) e di sommersione (depositi trasgressivi di spiaggia) (fig. 22). essi testimoniano oscillazioni eustatiche avvenute durante il periodo di “alto eustatico interglaciale” e, di conseguenza, anche la ggeenneessii ppoolliiffaassiiccaa ddeeii tteerrrraazzzzii del ii e del iii ordine. 7) la formazione dei terrazzi marini è avvenuta alla fine del pleistocene medio e nel pleistocene superiore in un regime deformativo estensionale, caratterizzato da sollevamento (0,5 mm/a) e da ripresa dell’attività delle faglie. ciò ha favorito l’erosione e la produzione di detrito; gli abbondanti aappppoorrttii ddeettrrii-ttiiccii del f. trionto hanno causato l’accentuata progradazione della spiaggia e la formazione del sistema barriera-laguna, come documentato dai terrazzi del ii e del iii ordine. 8) nell’area in esame ogni ordine di terrazzi si è formato, almeno in parte, a spese dell’ordine immediatamente superiore (figure 6, 14 e 20). ogni terrazzo ha perciò utilizzato, durante la sua formazione, una considerevole quantità di sedimenti marini e continentali del deposito terrazzato immediatamente superiore. iill rriicciiccllaaggggiioo di questi sedimenti clastici ha influenzato la formazione della superficie inferiore trasgressiva dei terrazzi e spiega il tappeto di grossi ciottoli (fig. 34 e 7) che la sovrasta (la superficie è tagliata nelle argille del substrato) e la presenza nei terrazzi del ii, iii e iv ordine di blocchi 86 l. carobene arrotondati di calcari algali, appartenenti in origine al terrazzo del i ordine (litofacies ca). 9) durante il sollevamento dell’area, gli alti livelli eustatici degli ultimi interglaciali hanno originato un caratteristico terrazzamento a gradinata (fig. 36). le antiche linee di riva del i, ii, iii e iv ordine si sono in tal modo “allontanate” progressivamente dalla l inea di r iva attuale. ii ll rraappppoorrttoo ssoolllleevvaammeennttoo//ddiissttaannzzaa che si può calcolare per ogni singola linea di riva fornisce valori angolari variabili tra 2,1° e 3°. iill rraappppoorrttoo ddiissttaannzzaa//eettàà fornisce invece i valori della “velocità di allontanamento” di ogni singola linea di riva; tali valori variano tra 1 e 1,5 cm/a. 10) la buona conoscenza dell’ampiezza delle superfici inferiori di erosione dei terrazzi e degli spessori dei depositi marini terrazzati ha permesso di calcolare la vveelloocciittàà ddii aarrrreettrraammeennttoo ddeellllee ffaalleessiiee per i terrazzi del ii e del iii ordine. i depositi di questi due terrazzi si compongono di una parte trasgressiva e di una parte superiore progradante-aggradante; essi possono perciò essere riferiti alla “prima semiampiezza di una oscillazione eustatica e climatica” (la cui durata è di circa 7.500-10.000 anni) (fig. 37). il confronto con le curve di risalita eustatica dell’ultimo interglaciale ha permesso sia di confermare i tempi ricavati indirettamente dalle paleocurve, sia di calcolare i tempi parziali riferiti alla fase trasgressiva e a quella di alto stazionamento. le velocità di arretramento sono riportate in tab. 2; i valori medi calcolati sono di 11 e di 9 cm/anno per il ii ed il iii ordine rispettivamente, mentre i valori riferiti al solo tratto trasgressivo delle superfici inferiori sono rispettivamente di 34 e di 38 cm/anno. 11) la genesi polifasica di un “terrazzo” (paragr. 3.6.) richiede lunghi intervalli di tempo che sono compatibili con un intero periodo caldo interglaciale, al quale corrisponde un aallttoo ppiiccccoo eeuussttaattiiccoo iinntteerrggllaa-cciiaallee. le oscillazioni climatiche nelle quali si articola un periodo interglaciale possono produrre singoli aallttii lliivveellllii ddii ssttaazziioonnaammeennttoo mmaarriinnoo (di durata molto più breve e a quote diverse tra loro), ai quali corrispondono singole e ben definite “linee di riva” (tab. 3). 12) iill ccoonnttrroolllloo ddeellllaa tteettttoonniiccaa nella genesi ed evoluzione dei terrazzi si evidenzia: a) mediante il rapporto sollevamento eustatico/sollevamento tettonico; b) con il sollevamento tettonico (pari a 0,5 mm/a) che ha portato il terrazzo più antico (i ordine) a 210 m di quota; c) con la presenza di faglie o fratture lungo le quali ha agito l'erosione durante le fasi di rimodellamento dei terrazzi, d) con leggere dislocazioni delle superfici terrazzate. i lineamenti tettonici emersi dalla presente ricerca hanno le seguenti direzioni medie: n26°, 40°, 60°, 120° e 140° (fig. 38). 13) con il sollevamento e l’emersione i terrazzi subiscono un rriimmooddeellllaammeennttoo che è tanto maggiore quanto più antichi essi sono. i processi che intervengono durante il rimodellamento sono di vario tipo e possono agire per centinaia di migliaia di anni, ma non sono continui, in quanto dipendono dalle periodiche variazioni climatiche. schematizzando un terrazzo marino sollevato come in fig. 41, è possibile evidenziare 6 gruppi di processi che agiscono su 6 superfici distinte: (pf.) paleofalesia; (ss.) superficie superiore del terrazzo; (fa.) falesia attiva; (v.v.) versanti vallivi; (f.v.) fondovalle; (f.c.) fascia costiera. l’effetto finale complessivo è di ridurre l’area della superficie superiore del terrazzo, che può diventare uno stretto crinale (tratto di uno spartiacque con andamento suborizzontale), oppure frazionarsi in uno o più rilievi isolati di quota simile. in tempi molto lunghi i processi elencati in fig. 41 portano alla completa distruzione del terrazzo. rriinnggrraazziiaammeennttii ringrazio i revisori per l’accurato e complesso lavoro di miglioramento del testo, in particolare l’amico carlo bosi. un ringraziamento anche al dott. cristiano queirolo per l’informatizzazione di dati e figure, e alla prof.ssa grazia vannucci per lo studio paleontologico dei calcari algali. lavoro eseguito con fondi del progetto 40% “evoluzione geodinamica dell’arco calabro-peloritano ecc.”, anno 1989, responsabile dell’unità locale all ’università della calabria: luigi carobene. programma murst “interazione clima-eustatismo nella sedimentazione marino-marginale ecc.”, responsabile dell’unità di bologna: maria luisa colalongo. progetti di ateneo di genova, anni 2000 e 2001, riguardanti il quaternario, responsabile luigi carobene. llaavvoorrii cciittaattii aharon p. & chappell j. (1986) oxygen isotopes, sea level changes and the temperature history of a coral reef environment in new guinea over the last 105 years. palaeogeogr. palaeoclimatol. palaeoecol., 5566(3/4), 337-379. amorosi a., colalongo m.l., pasini g. & preti d. (1999) sedimentary response to late quaternary sealevel changes in the romagna coastal plain (northern italy). sedimentology, 4466, 99-121. anderson r. s., densmore a. l. & ellis m. a. (1999) the generation and degradation of marine terraces. basin research, 1111, 7-19. bard e., fairbanks r., arnold m., maurice p., duprat j., moyes j. & duplessy jc. (1989) sea-level estimates during the last deglaciation based on δ18o and accelerator mass spectrometry 14c ages measured in globigerina bulloides. quaternary research, 3311, 381-391. bard e., hamelin b., arnold m., montaggioni l., cabioch g., faure g. & rougerie f. (1996) deglacial sealevel record from tahiti corals and the timing of global meltwater discharge. nature, 338822(18 july), 241-244. bellotti p., milli s., tortora p. & valeri p. (1995) physical stratigraphy and sedimentology of the late pleistocene-holocene tiber delta depositional sequence. sedimentology, 4422, 617-634. belluomini g., gliozzi e. & ruggieri g. e di branca m., delitala l. (1988) first dates on the terraces of the crotone peninsula (calabria, southern italy). boll. soc. geol. it., 110077, 249-254. bender m.l., fairbanks r.g., taylor f.w., matthews 87genesi, età, sollevamento ed erosione ... r.k., goddard j.g. & broecker w.s. (1979) uranium-series dating of the pleistocene reef tracts of barbados, west indies. geol. soc. am. bull., 9900(6), 577-594. bonifay e. & mars p. (1959) le tyrrhénien dans le cadre de la chronologie quaternaire méditerranéenne. bull. soc. géol. fr., sér. 7e, 11(1), 62-78. bradley (1957) origin of marine-terrace deposits in the santa cruz area, california. geol. soc. american bull., 6688, 421-444. bradley w.c. & griggs g.b. (1976) form, genesis, and deformation of central california wave-cut platforms. geol. soc. am. bull., 8877, 433-449. c.n.r. (1987) neotectonic map of italy. quaderni della ricerca scientifica, 44, n.114, 6 tavv. 1:500.000. carobene l. (1981) terrazzi marini, eustatismo e neotettonica. geogr. fis. dinam. quat., 33(1980), 35-41. carobene l. & ferrini g. (1993) morphological, sedimentological and tectonic features of diamantem.carpinoso marine terrace flight (tyrrhenian coast of northern calabria, italy). earth surf. proc. and landforms, 1188, 225-239. carobene l. & firpo m. (2002) – forme terrazzate relitte di genesi marina lungo la costa ligure tra genova e savona (liguria occidentale). i l quaternario, 77(1), 123-138. carobene l. & pasini g. (1982) contributo alla conoscenza del pleistocene superiore e dell’olocene del golfo di orosei (sardegna orientale). boll. soc. adriat. sc. trieste, 6644(1980), suppl., 36 pp., trieste. carobene l., colalongo m.l., pasini g. & raffi i. (1997) sequenze deposizionali del pleistocene medio nella valle del fiume crati presso tarsia (calabria). boll. soc. geol. it., 111166, 503-524. cassa per il mezzogiorno (1970) – foglio capo trionto 230 – i n.o.. carta geologica della calabria scala 1:25.000. cassa per il mezzogiorno (1971) foglio calopezzati – 230 – i s.o.. carta geologica della calabria scala 1:25.000. catalano s., monaco c. & tortorici l. (1993) pleistocene strike-slip tectonics in the lucanian apennine (southern italy). tectonics, 1122(3), 656665. chappell j. & shackleton n.j. (1986) oxygen isotopes and sea level. nature, 332244 (13 nov.), 137-140. chappell j. & veeh h. h. (1978) late quaternary tectonic movements and sea-level changes at timor and atauro island. geol. soc. american bull., 8899, 356-368. chen j. h., curran h. a., white b. & wasserburg g.j. (1991) precise chronology of the last interglacial period: 234u-230th data from fossil coral reefs in the bahamas. geol. soc. american bull., 110033, 82-97. ciaranfi n., guida m., iaccarino g., pescatore t., pieri p., rapisardi l., ricchetti g., sgrosso g., torre m., tortorici l., turco e. e di scarpa r., cuscito m., guerra i., iannaccone g., panza g.f. & scandone p. (1983) elementi sismotettonici dell’appennino meridionale. boll. soc. geol. it., 110022, 201-222. c.n.r. (1995) carta geomorfologica del bacino del trionto. gruppo naz. geogr. fis. e geomorf., scala 1:50.000, s.e.l.c.a., firenze. cocco e., caselli g., gisotti g. & spadea r. (1993) evoluzione geomorfologica di capo colonna (crotone, calabria) nel periodo storico e suoi rapporti col tempio di hera lacinia. riassunti seminario “evoluzione dell’ambiente fisico nel periodo storico nell’area circum-mediterranea”, pag. 48, ravello, italia. cortese e. (1895) descrizione geologica della calabria. riediz. 1983, 338 pp., casa del libro ed. cucci l. & cinti f.r. (1998) studio dei terrazzi marini dell’alto ionio cosentino: considerazioni su sollevamento regionale e deformazione tettonica locale. il quaternario, 1100(2) (1997), 549-556. d’alessandro l., genevois r. & marino a. (2001) dinamica recente della costa alta fra ortona e vasto (abruzzo centro-meridionale). mem. soc. geol. it., 5566, 53-60. dodge r.e., fairbanks r.g., benninger l.k. & maurasse f. (1983) pleistocene sea levels from raised coral reefs of haiti. science, 221199(4591), 1423-1425. fucini a. (1896) studio geologico sul circondario di rossano in calabria. atti acc., mem. xvii, s.4, 99, 1-87, tipogr. galatola, catania. gasperi g. (1995) geologia regionale. 464 pp., pitagora ed., bologna. ghisetti f. (1981) evoluzione neotettonica dei principali sistemi di faglie della calabria centrale. boll. soc. geol. it., 9988(1979), 387-430. ghisetti f. & vezzani l. (1981) contribution of structural analysis to understanding the geodynamic evolution of the calabrian arc (southern italy). journ. struct. geol., 33(4), 371-381. ghisetti f. & vezzani l. (1983) strutture tensionali e compressive indotte da meccanismi profondi lungo la linea del pollino (appennino meridionale). boll. soc. geol. it., 110011(1982), 385-440. harmon r.s., mitterer r.m., kriausacul n., land l.s., schawarcz h.p., garrett p., larson g.j., vacher h.l. & rowe m. (1983) u-series and amino-acid racemization geochronology of bermuda: implications for eustatic sea-level fluctuation over the past 250,ooo years. palaeogeography, palaeoclimatology, palaeoecology, 4444, 41-70. hearty p.j. (1987) new data on the pleistocene of mallorca. quatern. sc. rev., 66(3/4), 245-257. hearty p.j. (2002) revision of the late pleistocene stratigraphy of bermuda. sedimentary geology, 115533, 1-21. hearty p.j. & dai pra g. (1992) the age and stratigraphy of middle pleistocene and younger deposits along the gulf of taranto (southeast italy). journal of coastal research, 88, 882-905. hoang c-t. & hearty p.j. (1989) a comparison of useries disequilibrium dates and amino acid epimerization ratios between corals and marine mollusca of the pleistocene age. chemical geology, isot. geosc. sect., 7799(4), 317-323. hoyt (1967) barrier island formation. bull. geol. soc. amer., 7788, 1125-1136. hunter r. e., clifton h. e. & phillips r. l. (1979) depositional processes, sedimentary structures, and predicted vertical sequences in barred near88 l. carobene shore systems, southern oregon coast. journ. sediment. petrol., 4499, 711-726. israelson c. & wohlfarth b. (1999) timing of the lastinterglacial high sea level on the seychelles islands, indian ocean. quatern. res., 5511, 306316. kern j.p. (1977) origin and history of upper pleistocene marine terraces, san diego, california. geol. soc. am. bull., 8888(11), 1553-1566. kovanen d.j. & easterbrook d.j. (2002) timing and extent of allerød and younger dryas age (ca. 12,500-10,000 14c yr b.p.) oscillations of the cordilleran ice sheet in the fraser lowland, western north america. quatern. res., 5577, 208224. ku t.-l., ivanovich m. & luo s. (1990) u-series dating of the last interglacial high sea stands: barbados revisited. quatern. res., 3333(2), 129-147. kukla g., mcmanus j.f., rousseau d-d. & chuine i. (1997) how long and how stable was the last interglacial? quatern. sc. rev., 1166, 605-612. lovisato d. (1878) cenni geognostici e geologici sulla calabria settentrionale. boll. regio comitato geologico, 99 e 1100, roma. marra f. (1999) evidenze di tettonica trascorrente alto pleistocenica al confine calabro-lucano: analisi morfostratigrafica e strutturale del bacino del mercure. il quaternario, 1111(2) (1998), 201-215. martin l., suguio k. & flexor j.m. (1988) hauts niveaux marins pleistocenes du littoral bresilien. palaeogeogr. palaeoclimat. palaeoecol., 6688, 231239. martinson d. g., pisias n. g., hays j.d., imbrie j., moore t.c. & shackleton n.j. (1987) age dating and the orbital theory of the ice ages: development of a high-resolution 0 to 300,000-year chronostratigraphy. quatern. res., 2277(1), 1-29. massari f. & parea g.c. (1988) progradational gravel beach sequences in a moderateto high-energy, microtidal marine environment. sedimentology, 3355, 881-913. massari f., parea g.c., rainone m.l., vedovato l. & vivalda p. (1986) elementi di sedimentologia delle paleospiagge pleistoceniche marchigiane. atti riun. gruppo sediment. cnr., ancona, 5-7 giugno 1986, 81-103. moretti a. & guerra i. (1997) tettonica dal messiniano ad oggi in calabria: implicazioni sulla geodinamica del sistema tirreno-arco calabro. boll. soc. geol.it., 111166, 125-142. murray-wallace c. v. & belperio a. p. (1991) the last interglacial shoreline in australia – a review. quat.sc.rev., 1100, 441-461. mush d. r., kennedy g. l. & rockwell t. k. (1994) uranium-series ages of marine terrace corals from the pacific coast of north america and implications foe last-interglacial sea level history. qatern. res., 4422, 72-87. nummedal d. & swift d. j. p. (1987) transgressive stratigraphy at sequence-bounding unconformities: some principles derived from holocene and cretaceous examples. in spec. publ. of econ. paleont. and mineral., 4411, 241-260. oertel g.f., kraft j.c., kearney m.s. & woo h.j. (1992) quaternary coasts of the united states: marine and lacustrine systems. (fletcher c.h. & wehmiller j.f. ed.), spec. publ. soc. econ. paleont. miner., 4488, 77-87. 0gniben l. (1962) le argille scagliose ed i sedimenti messiniani a sinistra del trionto (rossano, cosenza). geol. romana, 11, 255-282. palmentola g., carobene l., mastronuzzi g. & sansò p. (1990) i terrazzi marini pleistocenici della penisola di crotone (calabria). geogr. fis. dinam. quat., 1133(1), 75-80. panizza m. 1966) carta ed osservazioni geomorfologiche del territorio di calopezzati (calabria). riv. geogr. it., 7733(1), 32 pp., firenze. panizza m. (1967) il pleistocene di crosia (rossano, cosenza). riv. it. paleontol. stratigr., mem. 1133, 131-194. parea g.c. & valloni r. (1983) le paleospiagge pleistoceniche della zona atri-silvi (abruzzo). atti soc. nat. mat. modena, 111144, 51-82. patacca e. & scandone p. (1989) post-tortonian mountain building in the apennines. the role of the passive sinking of a relic lithosferic slab. the lithosphere in italy, 159-176, acc. naz. lincei, 8800, roma. pirazzoli p. a. (1991) world atlas of holocene sealevel changes. elsevier oceanography series, 58. pirazzoli p. a., radtke u., hantoro w.s., jouannic c., hoang c.t., causse c. & borel best m. (i991) quaternary raised coral-reef terraces on sumba island, indonesia. science, 225522, 1834-1836. reinson g.e. (1992) facies 33s: response to sea level changes. (in walker r.g. & james n.p. ed.), geol. assoc. canada, 179-194, waterloo, ontario. ridente d. & trincardi f. (2002) eustatic and tectonic control on deposition and lateral variability of quaternary regressive sequences in the adriatic basin (italy). marine geology, 118844, 273-293. robustelli g. & aucelli p.p.c. (2002) i termini di chiusura del bacino pugliese (avanfossa sudappenninica) nell’area di poggio imperiale (foggia): caratteri stratigrafici ed implicazioni paleogeografiche. il quaternario, 1144(2) (2001), 173-186. roda c. (1967) i sedimenti del ciclo plio-pleistocenico sul versante ionico della sila, tra rossano e botricello. atti accad. gioenia sc. nat. in catania, s.6, 1188, 237-245. scandone p. (1982) – structure and evolution of the calabrian arc. earth evol. sc., 33, 172-180. selli r. (1962) le quaternaire marin du versant adriatique-ionien de la péninsule italienne. quaternaria, 66, 391-413. seidenkrantz m.-s. & knudsen k.l. (1997) eemian climatic and hydrographical instability on a marine shelf in northern denmark. quatern. res., 4477, 218-234. shackleton n. j. (1969) the last interglacial in the marine and terrestrial records. proocedings of the royal society of london, b117744, 135-154. shackleton n. j. (1987) oxygen isotopes, ice volume and sea level. quatern.sc.rev., 66(3/4), 183-190. shipp r. c. (1984) bedforms and depositional sedimentary structures of a barred nearshore system, eastern long island, new york. marine geology, 6600, 235-259. smart p.l. & richards d. a. (1992) age estimates for 89genesi, età, sollevamento ed erosione ... the late quaternary high sea-stands. quatern. sc. rev., 1111, 687-696. sorriso valvo m. (1993) the geomorphology of calabria. a sketch. geogr. fis. dinam. quat., 1166,, 75-80. stirling c.h., esat t.m., mcculloch m.t. & lambeck k. (1995) high-precision u-series dating of corals from western australia and implications for the timing and duration of the last interglacial. earth and planetary science letters, 113355, 115-130. suggate r.p. (1965) the definition of “interglacial”. journ. geol., 7733,, 619-626. sunamura t. (1992) geomorphology of rocky coasts. j. wiley & sons, new york. tortorici l., monaco c., tansi c. & cocina o. (1995) recent and active tectonics in the calabrian arc (southern italy). tectonophysics, 224433, 37-55. turco e., maresca r. & cappadona p. (1990) la tettonica plio-pleistocenica del confine calabro-lucano: modello cinematico. mem. soc. geol. it., 4455, 519529. vincent e. & berger w.h. (1981) planktonic foraminifera and their use in paleoceanography. in emiliani c. ed.: the sea, 77, 1025-1119, wiley, new york. warrick r.a., barrow e.m. & wigley t.m. ed. (1993) climate and sea level change: observations, projections and implications. cambridge university press. williams m., dunkerley d., de deckker p., kershaw p. & chappell j. (1998) quaternary environments. 329 pp., arnold, london. winograd i.j., landwehr j.m., ludwig k.r., coplen t.b. & riggs a.c. (1997) duration and structure of the past four interglaciations. quatern. res., 4488, 141154. 90 ms. ricevuto il 5 novembre 2002 testo definitivo ricevuto il 10 giugno 2003 ms. received: november 5, 2002 final text received: june 10, 2003 l. carobene cfd-fem 2d modelling of a local water flow. some numerical results antonio pasculli department of geotechnology, university of chieti campus universitario madonna delle piane, 66013 chieti (italy) e-mail: a.pasculli@unich.it abstract: pasculli a.: cfd-fem 2d modelling of a local water flow. some numerical results (chieti, italy) (it issn 0394-3356, 2008). the paper describes a first step towards the elaboration of flexible numerical research tools to study fluvial erosion, sediment transport, fluid-structures interaction (fsi), through the application of the computational fluid dynamics (cfd) and the finite element method (fem) techniques. a preliminary but necessary item to be explored is the analyses of the robustness of both mathematical and numerical features of the selected equations and the implemented algorithms. the unsteady navier-stokes equations, aimed to model a local 2d water flow, are introduced. to include turbulence, the urans (unsteady reynolds averaged navier stokes) two equations κ ε model, with the wall-functions proposed by s. fan et alii (1993), have been employed. at this step, important phenomena, such as free-surface influence, bed and banks morphologies changes, coupling between particles and fluid flow, have not considered. then the adopted numerical approach is discussed. spatial discretization is carried out by the linear finite element method (fem). a structured meshing with h like adaptability algorithm was developed. thus to avoid velocities and pressure instabilities related, respectively, to convective mode predominance respect to diffusive mode and incompressibility constraint (divergence free flow), the characteristic-based split (cbs) algorithm and the method of artificial compressibility (ac) have been applied. the dual time stepping method has been adopted with internal external local time stepping. the three steps of the cbs based on ac or the cbsac method (nithiarasu & liu 2006) are then applied and discussed. as first step, only some steady state parametric numerical experiments have been performed, considering a semi-implicit, approach. poiseuille flow test has been carried out also to clarify and to investigate in depth cbs performance. both laminar and turbulent regimes have been considered. the numerical results of the selected turbulence modelling are compared with some simple analytical expressions, valid for poiseuille flow. useful and important suggestions regarding the numerical tuning of some intrinsic parameters, specific to the selected algorithms, are acquired through the discussion of the general performance of the implemented algorithms. riassunto: pasculli a.: modellazione cfd-fem 2d di un flusso locale acquoso. discussione dei primi risultati numerici (chieti, italia) (it issn 0394-3356, 2008). il lavoro presentato in questo articolo descrive la prima fase di un'attività di ricerca il cui scopo è di elaborare degli strumenti numerici atti a studiare in maniera flessibile processi quali l'erosione delle sponde fluviali, il trasporto di sedimenti, l'interazione fluido struttura (fsi), mediante l'applicazione della fluidodinamica computazionale (cfd) e del metodo agli elementi finiti (fem). innanzitutto è necessario analizzare la robustezza sia degli aspetti matematici sia degli aspetti numerici delle equazioni e degli algoritmi implementati. sono state considerate le equazioni non stazionarie di navier-stokes per la simulazione di un flusso locale d'acqua in 2d. la turbolenza è stata inclusa mediante il modello a due equazioni κ ε, ottenute tramite le equazioni mediate di navier stokes (urans, unsteady reynolds averaged navier stokes) con le “funzioni di muro” (wall-functions), proposte da s. fan et alii (1993). in questa fase iniziale, non sono state considerate importanti caratteristiche dei fenomeni in considerazione, quali l'influenza della “superficie libera”, il cambiamento della morfologia al contorno, ossia sponde e letto fluviale, l'influenza reciproca tra i sedimenti e il flusso stesso. quindi si è discusso l'approccio numerico selezionato. per la discretizzazione spaziale è stato scelto il metodo agli elementi finiti (fem) lineari di tipo “strutturato”, con infittimento di elementi triangolari (h like adaptability). per evitare le instabilità numeriche connesse con le velocità e le pressioni, in particolare in regime a prevalenza convettiva piuttosto che diffusiva e per il soddisfacimento del vincolo di incompressibilità (con divergenza nulla delle velocità stesse), sono stati scelti, rispettivamente, il metodo delle caratteristiche applicato all'equazione della conservazione della quantità di moto suddivisa nella sua parte convettiva e diffusiva (characteristic-based split algorithm cbs) e il metodo della compressibilità artificiale applicata, in particolare, all'equazione di continuità (artificial compressibility ac). inoltre è stato applicato il metodo del doppio incremento temporale locale, “interno” ed “esterno” (dual time stepping; internal external local time stepping). l'algoritmo cbs-ac (nithiarasu & liu 2006) si risolve mediante un approccio iterativo in tre passi successivi. in questo lavoro è stato analizzato solo il moto stazionario. sono stati elaborati degli esperimenti numerici mediante un approccio semi-implicito. per un confronto con soluzioni analitiche si è scelto il classico moto alla poiseuille. lo scopo principale è stato l'approfondimento numerico delle modalità con le quali il metodo cbs risolve le equazioni. sono stati considerati sia il regime laminare, sia il regime turbolento. in particolare, i risultati numerici relativi ai modelli di turbolenza sono stati confrontati con espressioni analitiche semplificate, valide per flussi alla poiseuille. mediante la discussione dei risultati, sono state ricavate delle utili e fondamentali indicazioni sui valori numerici di alcuni parametri, caratteristici degli algoritmi introdotti, che regolano la convergenza degli stessi. key words: cbs stabilization, rans turbulence, numerical modelling. parole chiavi: stabilizzazione cbs, turbolenza rans, modellistica numerica il quaternario italian journal of quaternary sciences 21(1b), 2008 215-228 introduction the experimental studies of important processes and mechanisms, such as fluvial erosion, mass failure, sediment transport, are severely affected by intrinsic difficulties to acquire field data collections. a support for the numerical evaluation of important mechanical parameters, namely shear stresses near fluvial banks and bed rivers, the exchanged energy between the flow and the eroded material, particles lift and depositions, has been searching within the framework of hydraulic models and cfd approaches. some models have been 216 a. pasculli proposed using empirical data sets obtained from laboratory channels (simons d.b.& sentürk f. 1977, knight et al., 1984). recently some progress has been made in using analytical models (ke a n j.w., sm i t h j.d. 2004, 2006). although these approaches are promising, it is not yet clear whether such methodologies are entirely appropriate (ri n a l d i m. & da r b y s.e. 2008). thus the practise of using cfd modelling techniques as useful support to evaluate field data in river flows, that are difficult or impossible to measure, has now become established for a range of open-channel flow contests (lane s.n., et al., 2000 ; darby s.e. et al., 2004). actually, erosion and sediment transport phenomena involve multiple interactions among fluid flow, particles, moving boundaries, geotechnical characteristics of banks and bed. thus the main issues are the numerical solution of the equations related to the selected models. namely, navier-stokes and newton's laws equations have to be solved with their coupling. in order to pursue this objective, the cfd and the computational granular dynamics (cgd) (poschel, t.& schwager t. 2005) techniques could be applied. within the framework of these methodologies several approaches are available. the phenomena complexity implies, necessarily, a splitting of the modelling in two or more different spatial scales: macro scales of some tenth meters wide or more, and smaller scales of few meters wide or less. regarding the latter, a more accurate and, for this reason, more sophisticated and more cpu consuming time modelling is necessary. very accurate local calculation could be employed to evaluate stochastically (iliopoulos i., mito y., ha n r a t t y t., et al., 2003; pa s c u l l i a. & sc i a r r a n . 2006, 2007) the main mechanical parameters to be introduced in cheaper models like the shallow water or others, even if less accurate. the most accurate approach is the d i r e c t numerical simulation (dns) of fluid and particles flows (li c., mosyak a., hetsroni g. 1999, schmeeckle m.w. & nelson j.m. 2003, zohdi t.i. 2007). on the other hand, its application on large or medium scales is not very practical due to huge cpu time and memory, requested for high and either medium reynolds number. in order to get an unsteady high-frequency representation of the solution by a less expansive approach, l a r g e eddy simulation (les) has been investigated by many authors (ro d i w., et al.1997; sa g a u t p. 2002;). this technique, which is based on a low-pass filtering of the exact solution of the navier stokes equations, makes it possible to obtain a significant reduction in the complexity of the simulation by reducing the number of degrees of freedom. but les is still subject to severe constraints when wall bounded flows are considered, because (at least theoretically) the internal region of the boundary layer needs to be quasi-directly resolved, yielding large computational costs. because an accurate unsteady description of the solution is not needed everywhere when dealing with practical engineering problems, the idea of using zonal approaches has emerged (qu é m é r e p. & sa g a u t p. 2002). dns and/or les could be used in small localized subdomains where an accurate description of the flow is requested, while computing the rest of the configuration with a low-accuracy method. commercial cfd computer codes, in spite of the very large and qualified international research activities, several times lack of flexibility and internal intelligibility, so they do not always assure the solutions of those problems occurr ing within the computational geosciences framework and which could be solved (few) in enough satisfactory fashion with the now-days mathematical and numerical tools (ab a n t o j. et al. 2005; nithiarasu p., zienkiewicz o.c. 2006, pag. 5544). thus the aim of this work is to describe a first step of the process aimed to develop a research numerical tool, suitable for the employment of experimental correlations, theoretical models and so on, with the necessary flexibility and intelligibility. the starting point has been the 2d numerical implementation of the reynolds averaged numerical simulation (rans) with its u n s t e a d y version (urans), belonging to the lowaccuracy method set, but less expensive than the aforementioned ones. among many others (warner j.c. et a l. 2005) the k ε two-equation turbulence closure models has been selected (launder b.e. & jones w.p. 1972; jo n e s w.p. & la u n d e r b.e. 1972). the spatial discretization have been realized by fem approach. linear triangular elements have been selected. the adoption of the finite element standard galerkin methods implies instabilities in particular for convective mode predominance respect to diffusive mode . furthermore incompressibility causes pressure instabilit i e s. several methods have been proposed, including streamline upwind petrov-galerkin (supg), g a l e r k i n least squares (gls), finite calculus (fic) and more recently subgrid scale (sgs) approach (ch u n g t . j . 2006). in the present work the c h a r a c t e r i s t i c b a s e d split algorithm (cbs) and the method of artificial comp r e s s i b i l i t y (ac) have been applied. for the transient dual time stepping method has been adopted with internal external local time stepping (nithiarasu & liu 2006; nithiarasu p. & zienkiewicz o.c. 2006). one problems of the interaction between the fluid flow and both banks and bed surface is computing turbulent flows that are influenced by an adjacent soil (wall) boundary. thus the 2d wall-functions, proposed by s. fan et alii (1993), have been implemented. since the main purpose of the present work is to verify the robustness of the implementation of the selected fluid flow and turbulence models and their mean numerical features, many important issues regarding fundamental characteristics of the phenomena under study have not been considered. among others free surface and bedfluid interaction effects (souli m. & zolesio j.p. 2001; baghlani a. & talebbeydokhti n. 2007), meshing updating (xu x. & harada k. 2003). then some parametric studies regarding h adaptive structured meshing have been carried out. poiseuille test has been utilized to explore how cbs methodology can affect the stabilization of the fluid velocities. some important parameters had to be correctly tuned to reach convergence of the iterative procedure. the outcomes of the assumed turbulence modelling obtained by turbulent poiseuille test are compared with the prandtl's mixing length theory and deissler's sublayer and buffer zones models. the integral equation related to the latter model has been solved by an iterative approach. future developing will concern with further rans analyses and the link among different-accuracy approaches applied at different scales: shallow water, urans, les, dns, cgd. 1. a general 2d fluid dynamic modelling in this paragraph a general 2d fluid dynamic modelling, developed in both its mathematical and numerical features will be described and discussed. the algorithms, translated in a research computer code performed by the author by visual fortran 2000 compilator through the implementation of about twenty thousands instructions, have been tested and some numerical results have been discussed in this paper. the physics conservation laws are the mathematical framework of fluid dynamics. thus the usual navier stokes equations have been considered (in s.i. units). 1.1 mass conservation in einstein summation convention: ∂ρ ∂ (ρ ui) –––– + ––––––– = 0 i = 1,2 (1) ∂t ∂xi where ρ is the water-sediments volumetric mass density, ui the i th velocity component. 1.2. momentum conservation equation for the momentum equation it is necessary to introduce the dissipative term due to water-sediment viscosity. in order to build constitutive laws related to viscous fluids the strain temporal rates tensor has to be introduced, which, for small deformation assumes the following expression: 1 ∂ui ∂uj ε. ij = –– ( –––– + ––––) (2) 2 ∂xi ∂xj it is expressed also by means of the following vector: ε. = [ε.11, ε . 22, 2ε.12] t (3) the relation between the strain tensor and the stress tensor, for linear newtonian and isentropic fluids is provided by two terms: the deviatoric stressstrain term and the isotropic term. the first one is: 1 1 τij = σij – –– δij σkk = 2µ (ε. ij – –– δij ε . kk) (4) 2 2 where µ is the dynamic viscosity. the complete form is: ∂ux ∂uy ∂ux ∂uy(––– – –––) (––– + –––)∂x ∂y ∂y ∂x τ = µ ( ) (5) ∂uy ∂ux ∂uy ∂ux(––– + –––) (––– – –––)∂x ∂y ∂y ∂x the second term, isotropic term, is defined as pressure: 1 σ11 + σ22 p = – –– σkk = – –––––––– (6) 2 2 volume viscosity has been neglected. in the turbulent regime flow, a further stress term, due to turbulent kinetic energy k, should be introduced 217cfd-fem 2d modelling of a local ... ∂ui τt i j = µt ––– – ρk where ρ is the volumetric water sedi∂xj ments mixture density, µt is the turbulent dynamic viscosity which will be described in following paragraphs, while: k = half of the turbulent square velocity = –1 2 (u’2 x + u’2 y ) where u’2 x , u’2 y are velocities fluctuation. µ is the laminar dynamic viscosity. thus: ∂ρui ∂[(ρuj) . ui ] ∂(τij + τt ij ) ∂ρ –––– + ––––––––– – –––––––– + ––– – ρgi = 0 i=1,2; j=1,2 (7) ∂t ∂xj ∂xj ∂xi 1.3. energy conservation equation to complete the review of all the base equations necessary to elaborate a numerical model of a 2d local water flow including phenomena like fluid-structure interaction, free-surface, bed and river-bank erosion with their topography change, sediment deposition and flow mass accretion, it is mandatory to show, at least, the equation related to the advection of a scalar quantity, affected by a turbulent regime as well. thus the form of the mechanical energy is briefly reported and described as example, notwithstanding its contribution is not discussed in this paper. in a 2d mechanical flow model, excluding thermo-chemical contribution and considering gravitational potential energy as a volumetric source, the specific energy for mass unity is related only to kinetic component, defined as: 1 e = – (u2 x + u2 y ) (8) 2 applying the energy conservation principle t h e following equation is deduced (in a compact form): ∂ρe ∂[(ρui) e ] ∂(ρui) ∂(τij + τt ij ) uj –––– + –––––––– + ––––– – –––––––––– – ρgi ui – q = 0 (9) ∂t ∂xi ∂xi ∂xi ∂ui where, in particular τt ij = µt ––– – ρk as previously intro∂xj duced, while ρgi ui is the variation during the transitory of the potential energy due to gravity. the q [w] [m]3 term is the volumetric energy source which could include, for example, buoyancy forces effects due to spatial variability of water-sediments mixture. 2. turbulent modelling among others, the rans (reynolds averaged navier stokes) two equations k ε modelling with the 2d w a l l f u n c t i o n s proposed by s.fan et alii (1993), has been implemented. it consists, fundamentally in two equations which describe the generation, the diffusion, the convection and the dissipation of the energy due to turbulence. 2.1. production and transport equation of the turbulent kinetic energy the turbulent kinetic energy is considered as a scalar quantity. thus by means of the general scalar conservation equation, the following relation yields: ∂ρk ∂ [( ρux) . k] ∂ [( ρuy) . k] ∂ µt ∂k ––– + –––––––––– + –––––––––– – –– [(µ + –––) ––– ] –∂t ∂x ∂y ∂x σk ∂y (10) ∂ µt ∂k – –– [(µ + –––) ––– ] + (p + g – ρε) = 0 ∂y σk ∂y where [k] = [m]2[s]-2 = semi square of total turbulent k2 kinetic energy, µt = ρcµ fµ ––– turbulent viscosity; ε ∂ux 2 ∂uy 2 ∂ux ∂uy 2 p = µt { 2 . [ ( –––) + ( –––) ] + ( ––– + –––) } is the source ∂x ∂y ∂x ∂y of the turbulent kinetic energy due to shearing stress; g is the turbulence source due to buoyancy forces. 2.2. production and transport equation of the dissipation rate of the turbulent kinetic energy by means of the same approaches adopted in the previous paragraph: ∂ρε ∂ [( ρux) . ε] ∂ [( ρuy) . ε] ∂ µt ∂ε ––– + ––––––––– + ––––––––– – –– [(µ + –––) ––– ] –∂t ∂x ∂y ∂x σk ∂x (11) ∂ µt ∂ε ε – –– [(µ + –––) ––– ] + –– (cε1fε1 p + cε1g –cε2fε2ρε) = 0 ∂y σk ∂y k where: [ε]=[m]2[s]-3 is the volumetric density rate dissipation of the turbulent kinetic energy. 2.3. experimental parameters for these kind of turbulence models it is necessary to calibrate the mathematical equations with experimental parameters. in this paper the following values have been selected: cµ = 0.09; cε1 = 1.44; cε2 = 1.44; σt = 0.9; σk = 1; σε = 1.3 2.4. wall functions the following are the functions which introduce the reasonable lowering of the turbulence near rigid boundaries (wall functions) (s. fan, et alii, 1993): k2 √ −−− rk √ −−− rk rk rk rt = ––; fw = 1-exp {– ––––– +(––––– – ––––)[1-exp(– –––)] 3 };νε 2.3 2.3 8.89 20 fw fw rk fµ = 0.4 ––––– (1 0.4 ––––– ) [1-exp ( – ––––––) ] 3 ; √ −−−−− rt √ −−−−− rt 42.63 0.4 rt fε 2 = {1– ––– exp [ – ( –––) 2 ] 3 } f 2 w; 1.8 6 fε 1 = 1 dw where: rk = ––– √ − k, dw is the minimum distance of the ν considered point from the closest rigid boundary; µtν = –– is the kinematic viscosity [ν]=[m]2[s]-1 ρ 2.5. boundaries conditions related with turbulence modelling along rigid boundaries, the turbulent kinetic energy is assumed to be zero, while on boundary elements ∂k 0,5 2 εw = 2ν ( –––– ) where n is the normal direction. at the ∂n eventual inlet flow, it is assumed: k = 0.05 x √ −−−−−−−−− u2 x + −− u2 y . 3. numerical modelling the previous equations are characterized by non self adjoint differential operators, due to convective terms. as it is well known, in this case, the adoption of the finite element standard galerkin methods i m p l i e s instabilities in particular for convective mode predomin a n c e respect to diffusive mode. furthermore i n c o mp r e s s i b i l i t y causes p r e s s u r e i n s t a b i l i t i e s. thus to avoid velocities and pressure instabilities the c h a r a c t e r i s t i c based split algorithm (cbs) and the method of artificial c o m p r e s s i b i l i t y (ac) have been, respectively, applied. for the transient dual time stepping method has been adopted with internal external local time stepping. the cbs based on artificial compressibility ac or the cbs-ac (nithiarasu & liu 2006) method, despite other methods proposed in literature, consists in only three steps. the most important advantage of this procedure is the possibility to implement arbitrary order for the velocity and the pressure interpolation without an artificial damping. in this way the satisfaction of the heavy lbb (babuska 1973; brezzi 1974) condition is avoided. in this paper the standard galerkin fem (weighting functions are the shape functions) and eulerian triangular meshing with linear interpolation for both velocity and pressure have been selected (ch u n g t.j., 2006, pag. 273-283). important consequences are: a m o r e simplicity and affidability of the implementation process; very fast algorithm for non high mach n u m b e r flow, with a very good precision. the three steps are summarized as (ni t h i a r a s u p., co d i n a r., zi e n k i e w i c z o.c. 2006): step 1 ∂ (uj ui) ∂(τij + τt ij) δt ∂ ∂ (uj ui) δu*i =δt [– –––––– + ––––––– + (ρgj) + –– uk ––– (–––––– – ρgi)] n (12) ∂xj ∂xj 2 ∂xk ∂xj where ui = ρui is the flux vector, while all the other symbols meanings are supposed to be evident. the application of the standard galerkin fem, requests the employment of unknowns related to each node. the global solution is carried out by means of an assemblage of each single solution related to connected spatial elements. thus each unknowns, labelled at a global level as ui where i=1,n with n = total nodes number, must be labelled again at a local level as umi, where m is a local index associated to each node belonging to the selected element. for the linear triangle element, m = 1 , 2 , 3 corresponding to triangle vertex (many other options are available). in particular regarding eq. (12), the following 3 equations, whose unknowns are the flux vector umi with i=1,2 (for each spatial 218 a. pasculli component x and y) and with m=1,2,3, should be solved, following the standard galerkin fem approach: ∫ω nm (∑3 k=1 nk δuki) dω = ∂u–j (∑3 k=1nk uki) ∂nm –δt [ ∫ω nm ––––––––––––– dω+ ∫ω –––– (∑3 k=1nk (τij+τt ij)k)dω – ∂xj ∂xj δt2 ∂ (u–k nm) ∂u–j (∑3 k=1nkuki) – ∫ω nm∑ 3 k=1nk (ρgj)kdω ] n + –– [ ∫ω ––––––– (– –––––––––––––+ 2 ∂xk ∂xj + ∑3 k=1nk (ρgj)k ) dω ] n +δt [ ∫γ n* (τij+τt ij) nj dγ ] n where nm, with m=1 , 2 , 3, are the shape functions which, in this case, are a linear x, y, expressions: nm = am + bm x = cm y where am, bm, cm are simple functions of the global coordinate of the related mt h node (ch u n g t.j. 2006, pag. 273-283; zienkiewicz o.c., taylor r.l. & nithiarasu p. 2006, pp. 88-91) step 2 1 ∂un i ∂δu*i ∂ 2 pn ∂2δp δρ= (––) n δp=– δt [––– +θ1 ––––– –δtθ 1(–––––+θ2–––––)] (13) c2 ∂xi ∂xi ∂xi∂xi ∂xi∂xi step 3 ∂pn+θ2 δt 2 ∂ ∂pn u**i =– δt –––––– + ––– un k ––– ( –––– ) (14) ∂xi 2 ∂xk ∂xi for which the θ wilson procedure (also called β method, ch u n g t.j. 2006, pag. 72) has been adopted as well. the flux value calculated at time step 1 is corrected: un+1 i = u n i + δu*i + δu**i , so at the end of the (n+1)th time step: un+1 i = un+1 i /ρ. by these three steps, fluid-dynamics field (velocity and pressure) is evaluated. the momentum equations are non linear due to convective terms. thus to linearize the system, the velocity product of the convective terms are assumed to be formed by the value of the velocity evaluated at the previous step, calculated as an average within the local element, corresponding to the value assumed by the velocity at the gauss point of the element (barycentre), ux1 + ux2 + ux3 uy1 + uy2 + uy3 and the value: u _ x = ––––––––––––– u _ y = –––––––––––––, 3 3 where ux1, uy1 are the element nodal velocity values. for example for the x stability term: b1b1 b1b2 b1b3δt 2 δt 2kuux = – ––– a[u_xu _ x( b2b1 b2b2 b2b3 ) + 2 b3b1 b3b2 b3b3 c1c1 c1c2 c1c3 ux1 + u _ xu _ y ( c2c1 c2c2 c2c3 ) ] ( ux2 ) c3c1 c3c2 c3c3 ux3 where δt is the time step, a is the triangular element area, while bi and ci are the parameters characterizing the shape functions previously introduced. the complete numerical solution of the selected modelling is summarized in the following list: 1. momentum equation solution without pressure terms (splitting procedure); 2. pressure calculation by poisson equation; 3. correction of the velocities evaluated at step 1; 4. energy and scalar quantity (like sediment concentration) calculation; 5. calculation of the parameters to be introduced in the k ε equations; 6. calculation of the production and transport (convective and diffusive) of the turbulent kinetic energy; 7. calculation of the turbulent kinetic energy dissipation. 4. time-steps it is well known that in convective predominance flux, in order to avoid instabilities, the time step should assume optimal values (petrov galerkin), function of u . h peclet number pe = ––––– where u is the velocity, h the 2k mesh characteristic size and k is the diffusion parameter (thermal or mass diffusion, kinematic viscosity and so on). peclet number depends on local conditions. thus a nodal time step has been introduced by the evaluation of the minimum time step for each node. 4.1. artificial compressibility in step 2 (13), previously described, the artificial c o m p r e s s i b i l i t y (ac), by means of the adoption of an enough low value of the sound velocity, has been introduced. (nithiarasu p.& liu c.b. 2006). this aproach is correct in the steady state situation if any. so in the 1 1 step 2: ( –– ) n δp ≈ ( –– ) n δp where β is an artificial parac2 β 2 meter with a velocity dimension. it could be calculated by (zienkiewicz et al., 2006): β = max (ε, uconv , udiff) (15) where ε is a small constant in order to avoid zero values ν of velocities, while uconv = √  u2 x + u2 y  and udiff = – with ν = h kinematical viscosity, h = characteristic dimension of the triangular element. the final local time step is: h δt = ––––––––––––– (16) √  u2 x + u2 y  + β it is possibile to apply the same ac procedure for the transient as well through the dual stepping approach. 4.2. dual time stepping in order to recover the true transient for the artificial compressibility ac, any of each of the three steps (12), (13) and (14) should be modified. within each real time step δt an internal iterative loop is carried out to go from time nth to time (n+1)th. then, let's select the third step (14) in its matrix form and consider the following modified expression (for symbols meanings see nithiarasu p.& zienkiewicz o.c. 2006): δum δtint um – un ––– = – m-1 u [ gt (pn + θ 2δpm) + –––– ppn ] – ––––––– (17) δτ 2 δt 219cfd-fem 2d modelling of a local ... 220 fig. 1a derivate of the x velocity vs y direction, 20 nodes. derivata rispetto ad y della velocità lungo x, 20 nodi. fig. 1b derivate of the x velocity vs y direction, 6 nodes. derivata rispetto ad y della velocità lungo x, 6 nodi. 3um +1 – 4um + 4um-1 where δum = ––––––––––––––––– which allows the tran2 sient to be second order in time (chung t.j. 2006, pp. 46-49), δpm = pm – pn. when iterating within each internal loop, δtext and δtin assume the meaning of pseudo time steps and the meaning of stabilization parameters increasing the acceleration towards the steady state convergence. therefore for each iteration, a local values h of δtext = –––––––––––– and δti n = γδte x t, with γ>1, obtained √  u2 x + u2 y  + β by attempts aimed to reach convergence, are numerically provided. the iterations stop when the function defined as: √  σnodes i = 1 (|u|n+1  – |u|n)2  epsilon = –––––––––––––––––– (18) √  σnodes i = 1 (|u|n+1  )2  assumes a value lower than a prescribed tolerance, whose range is usually 10-4 ÷ 10-6. 5. matrix inversion and derivative in step 1 (12) and step 2 (13) of the split procedure, the solution only require the inversion of mass matrix related to velocities and pressure. such steps are called explicit and generally are accomplished using approximation by a diagonal (lumped) form (zienkiewicz o.c. et alii 2006, pag.91-92). such lumping for steady state problems make steps 1 to step 3 very fast and the related errors are of no consequences as terms involving time variation disappear at a converged (steady state) solution. however, for transient problems, quite serious errors can occur and in such cases an additional iteration is used to obtain a consistent solution (zienkiewicz o.c. et alii 2006, pag.61-63). different important parameters, for example the vertical gradient of the water-sediment mixture, depend on the first and on the second derivative. a fem first derivative can be employed considering the derivative of the fem approximation of the velocity in each element, whose expression is: u(e) x = l1 . ux1 + l2 .ux2 + l3 . ux3, where l1 = ai + bi x + ci y x3 – x2 (in particular, for example, c1 = –––––– , a= element area, |2a| x2 and x3 abscissas of the selected triangular element, as previously discussed see: ch u n g t.j. 2006, pag. 273-283), uxi is the velocity values at the ith node of the element “e”. thus: ∂u(e) x (x3 – x2) (x1 – x3) (x2 – x1) ––– = ––––––– ux1 + ––––––– ux2+ ––––––– ux3 (19) ∂y |2a(e)| |2a(e)| |2a(e)| the average is then obtained weighting the expression (19) by the area a( e ) of all the element to which the selected node belongs. it was assumed a parabolic ux (y) velocity profile, ux (m/s) = 1. + y . (1 – y), and a structured uniform meshing of a rectangular strip, similar to that displayed in fig. 2a. then in fig.1a and fig. 1b, comparison among different calculated value of the first derivative, has been reported. the comparison has been carried out considering the fem expression, the velocity ratio along a selected vertical line (difference element method) and the exact analytical expression (1–2y), for 20 and 6 nodes uniform grid. the figures show clearly that this kind of fem approach is poor at the border respect to the dem model. this is due to the particular selected averaging technique. thus a particular care should be employed to adopt a different more suitable approach to provide a correct first and second derivatives especially, in particular, close to solid boundary zones within which shear stress has to be evaluated. in general such problems arose where discontinuities can occur. from the above discussion it follows the strong necessity of checking the robustness of the implemented algorithms, before any attempts of doing numerical evaluation of actual phenomena. thus this is the aim of the following paragraphs. 6. numerical tests among available fluid dynamical analytical tests designed to check the correctness of numerical algorithm, the poiseuille problem has been selected. it is supposed that through a 0.5 m wide and 1. m. length a. pasculli 221 horizontal longitudinal strip a water flow occurs. the reynolds number is assumed equal to 103. the inlet velocity profile, within the whole transient, has been assumed parabolic along the longitudinal coordinate x, while zero along y. thus, initially, the velocity is zero everywhere, except at the inlet of course. no slip condition (zero velocities) was assumed on the two longitudinal boundaries. at the inlet the pressure is assumed to be p = 9.8.104 + 8.µl pascal (according to the theory), where l is the length of the strip (equal to 1 m in this case) while, initially, in any other points the pressure is equal to 98000 pa. the theoretical distribution of the pressure is uniform along direction transversal to flow vector (y direction) and linearly decreasing along the longitudinal coordinate. as the flowing surface is horizontal, the hydrostatic load is excluded. in all the calculation an uniform or clustered structured meshing, obtained by 18 nodes along the y direction and 36 nodes along the longitudinal (x) direction, have been selected. thus the velocity components along x, y and the pressure have been evaluated by the numerical algorithm everywhere, outlet section included, except at the inlet and on the two longitudinal boundaries. furthermore both laminar and turbulent poiseuille cases have been studied and compared to each other. in all the “laminar” elaborations carried out in this paper, the following parameters have been selected: θ1 = 1., θ2 = 1. safety coefficient = 0.9; pressure stability c o e f f i c i e n t (rateo between internal and external time step) = 107; β reference velocity (ac model) = 1 m/s. the numerical problem, actually, is 2d. in fact the numerical result value of uy should be vanishing if the selected algorithms and its implementation are correct! as a first testing step, only steady state numerical elaborations have been carried out and discussed in this paper. 6.1. laminar flow steady state in fig. 2a and fig. 2b, the total vector velocity profiles u = uxi + uyj, numerically evaluated for a structured uniform meshing, after different iterative number of steps, have been reported. the y velocity component fig. 2a uniform structured meshing discretizzazione strutturata uniforme fig. 2b laminar poiseuille test; total velocity profiles at different iterative steps, uniform meshing test di poiseuille laminare; profili della velocità totale a differenti passi iterativi con distribuzione uniforme di elementi cfd-fem 2d modelling of a local ... 222 uyj, correctly, vanishes. in fig. 3 the results of an elaboration, carried out without the cbs stabilization term, is shown. i t worths to note that without cbs stabilization term, the flow plots show an evident instabilities and the calculation does not converge. then, the influence on the numerical results of the non uniform grid meshing has been explored. to this purpose the following coordinates transforming algorithm has been introduced: β + 1 x-α –––– 1-α (2α + β ) . (–––––) + 2α – β β – 1 x’ = l . –––––––––––––––––––––––––––––– β + 1 x-α –––– 1-α (2α + 1) [ (–––––) + 1]β – 1 (20) β + 1 y-α –––– 1-α (2α + β ) . (–––––) + 2α – β β – 1 y’ = h . ––––––––––––––––––––––––––– β + 1 yα – ––– 1-α (2α + 1) [ (–––––) + 1]β – 1 where (x, y) e (x’, y’) , respectively, are nodes coordinates before and after the transformation. l is the length, while h is the wide or the height of the rectangle, 0 < α e 1 < β < ∞ are two parameters to be adjusted in input and from which the elements clustering density depends. velocities numerical results, carried out on a clustered element grid, fig. 4a, have been displayed in fig. 4b. fig. 3 laminar poiseuille test; velocity profiles without cbs stabilization term test di poiseuille laminare; profili di velocità ottenuti senza il termine di stabilizzazione cbs fig. 4b laminar poiseuille test; total velocity profiles at different iterative steps, lateral boundaries meshing clustering test di poiseuille laminare; profili della velocità totale a differenti passi iterativi con addensamento laterale di elementi fig .4a lateral boundaries meshing clustering addensamento di elementi sui bordi laterali a. pasculli 223 the plot of fig. 5 have been obtained after 500 iterative steps, with just only lateral boundaries meshing clustering (fig. 4a). the velocity profiles show a general good behaviour, but the numerical analysis reported in fig. 5a and 5b, reveal a substantial difference (about 30%) among numerical and analytical values of the velocities just along the boundaries where the results, for erosion phenomena elaboration, should be more accurate. any way, it was reached an almost perfect symmetry (within the 10th decimal digit) respect to the longitudinal axes, due to the symmetry of the grid, not obtainable with a different spatial covering strategy also if through the same type of element. the pressure profile is very satisfactory and uniform (0.45% maximum relative error) showing, any way, the same numerical qualitative trend of the velocities profiles. figs. 6 set reports the results and the comparison obtained after 2000 iterative steps. the overall results for both velocities (0.9% as maximum relative error) and pressure (0.08% !) are very satisfactory. furthermore other non reported plots show that the calculated numerical y component velocities, provided by the solution of the related 2d numerical algorithms (theoretically zero), do not exceed 10-5 m/s. 6.2. turbulent poiseuille problem for the turbulent poiseuille problem, the following parameters have been selected: θ1 = 1., θ2 = 1. s a f e t y c o e f f i c i e n t = 0.2; pressure stability coefficient ( r a t e o between internal and external time step) =2.; β reference velocity (ac model), suggested for high reynolds number, = 1 m/s. in particular, to obtain the convergence, it was necessary to drastically lower the safety coefficient: from 0.9 down to 0.2. fig. 7a shows the averaged velofig. 5a relative error distribution of longitudinal velocity errore relativo della velocità longitudinale fig. 5b relative error distribution of the pressure errore relativo della pressione fig. 6a laminar poiseuille test; total velocity profiles after 2000 iterations, lateral boundaries meshing clustering test di poiseuille laminare; profili della velocità totale dopo 2000 iterazioni con addensamento laterale di elementi fig. 6b relative error distribution of longitudinal velocity errore relativo della velocità longitudinale fig. 6c relative error distribution of the pressure errore relativo della pressione cfd-fem 2d modelling of a local ... 224 cities profi le, obtained with an upper and lower meshing clustering after 3000 iterative steps. from fig. 7a it is possible to outline the capability of these kind of algorithm to provide and to forecast the occurrence of a thin boundary layer, within which a strong velocity variation and for this reason a strong shear stresses occur. fig. 7b and fig c show, respectively, the cross distribution of the turbulent energy production and the cross distribution of the temporal rate of the dissipation of the turbulent energy. their profiles are rather distorted especially close to the solid boundaries. thus a further calculation with the total clustering of all the boundaries have been carried out: fig. 8a. the following are the selected values of the clustering constants: α = 0.5 and β = 1.05. as figs.8 display, turbulent kinetic energy and its dissipation rateo shapes are closer to a parabolic profile than the previous case. also in this case a boundary layer occurs. 6.3. numerical-analytical turbulent poiseuille problem comparison in order to make some comparisons with simplified turbulence models, the prandtl's mixing length fig. 7a turbulent poiseuille test; total velocity profiles after 3000 iterations, lateral boundaries meshing clustering test di poiseuille laminare; profili della velocità totale dopo 3000 iterazioni con addensamento laterale di elementi fig. 7b distribution of the turbulent energy along y distribuzione dell'energia cinetica turbolenta y fig. 7c distribution of the turbulent kinetic energy dissipation distribuzione della dissipazione dell'energia turbolenta lungo y fig. 8a clustering of all boundaries addensamento di elementi sui tutti i bordi fig. 8b cross turbulent energy energia turbolenta lungo le sezioni fig. 8c cross turbulent energy dissipation dissipazione dell' energia turbolenta lungo le sezioni a. pasculli 225 theory and deissler's sublayer and buffer zones models (brodkey r.s. 1967, pp.. 240-252; bird r.b. et al.1960, pp. 149-161) have been selected. the comparisons are necessarily semiquantitative since different assumptions underlay each models. dimensionless parameters are introduced: u u+ = –– is the dimensionless velocity, where ux is, u* in this case, the longitudinal ux velocity; u* = √  τ0 – is the reference velocity, while τ0 = µ – – – d ux is ρ dy the shear stress at the wall; u* ρ y+ = y –––– is the dimensionless distance from the wall. µ in prandtl-deissler approach the turbulence region is divided into three main areas: viscous or laminar sub-layer 0 ≤ y+ < 5; buffer layer 5 ≤ y+ < 26; turbulent core 26 ≤ y+ for each area, separate equations yield. within the turbulent core prandtl introduced the logarithmic velocity distribution which can be rearranged in the following dimensionless form: 1 u+ = –– ln y* + b (21) k by experimental considerations, deissler suggested to assume k = 0.36. further he found that at the border y+ = 26 between the buffer and the turbulent area, the dimensionless velocity assumes the value: u+ = 12.85. it follows that in equation 21 b = 3.8. many other relations should be applicable in viscous and buffer layers, but this approach is undesirable. thus efforts have been made to reduce the number of equations by combining the sublayer and buffer zones. deissler, assuming an exponential form of the eddy viscosity, suggested the following integral equation: dy+ u+ = ∫ v+ 0 –––––––––––––––––––––––––––– (22) 1 + n2 u+ y+ [ 1 – exp ( – n2 u+ y+)] equation (22) has been solved by a numerical iteration methods, whose algorithm has not been reported in this paper. each integration has been realized by three gauss points approach. the results are reported in figs. 9. the analytical values are compared with the numerical results carried out with the nodalization reported in fig. 8a figs. 10 are related to analytical and numerical distribution velocities calculated at the section 0.86482 m far from the inlet. further, also the inlet velocity input has been considered in order to visualize how the parabolic input velocity distribution is deformed by the selected turbulence model. as the figs. 10 show, the match between numerical and analytical results are satisfactory within the viscous layer, while in the other zones the comparison is not well enough. other calculations, not reported in this paper, suggest that the problem is due to the inadequate number of elements to cover the geometrical section. conclusion in this paper the effort and the care necessary to develop a cfd-fem research computer code, aimed to perform numerical evaluations related to banks and bed river erosion, sediments transport and structures-fluid interactions have been just sketched. as a consequence, it should be stressed the importance of all the essentially four related steps: the selection of the most suitable physical models by the undertaken study purpose point of view, the accuracy and consistence of the mathematical “translation” of the already selected physical approach, the accuracy and consistence of the numerical tools employed to solve mathematical models and some experience and skil l on p r o g r a m m i n g. on the other hand several issues have been not considered, like the impact of the morphology and its change, shock front propagation, free surface flows, inclusion of the computational granular dynamics and many other ones. the discussion of the results points out the sensitivity of the employed algorithms not only to the mesh size and to their distribution, but also to some intrinsic “experimental dials” (safe coefficients, explicit vs implicit ratio) and to a correct number of iterations, whose knowledge reveals to be fundamental. any way the results discussed in the paper, regarfig.9a universal turbulent velocity distribuzione universale delle velocità turbolente fig.9b universal turbulent velocity in the viscous layer distribuzione universale delle velocità turbolente nella zona viscosa cfd-fem 2d modelling of a local ... ding the comparison among numerical and available analytical values, carried out for p o i s e u i l l e p r o b l e m , related to both laminar and turbulent modelling, show good performance in regions close to the rigid boundary in which eventual erosion can occur. suggestions come up in order to improve the turbulence numerical results by optimizing both distribution and number of the elements. next efforts will be concerned with more checks on turbulence models, the exploration of other approaches like sph (smoothed partic le h y d r o d y n a m i c s), meshless method, pfem (p a r t i c l e finite element methods) which seem to be very promising. acknowledgments the author would like to thank two anonymous referees for their effort and useful suggestions. bibliography abanto j., pelletier d., gadon a., trepanier y., reggio m. (2005) -verification of some commercial cfd codes on atypical cfd problems aiaa paper, reno. ba b u s k a i. (1973) the finite element method with lagrangian multipliers numer. math. 2 0, pp. 179-192. ba g h l a n i a. & ta l e b b e y d o k h t i n. (2007) a mapping technique for numerical computations of bed evolutions applied mathematical modelling 31, pp. 499-512. bi r d r.b., st e w a r t w.e., li g h t f o o t e.n. (1960) transport phenomena john wiley & sons, inc. new york. br e z z i f. (1974) on the existence, uniqueness and approximation of saddle-point problems arising from lagrange multipliers rev. francaise d'automatique inform. rech. oper., ser. rouge anal. numer. 8(r-2), pp. 129-151. brodkey r.s. (1967) the phenomena of fluid motionsaddison-wesley series in chemical engineering. ch u n g t.j. (2006) computational fluid dynamics cambridge university press. da r b y s.e., sp y r o p o u l o s m., br e s s l o f f n. a n d ri n a l d i m. (2004) fluvial bank erosion in meanders: a cfd modelling approach in garcia de jalon lastra, d. and martinez p.v. (eds.), proceedings of the v int. ass. of hydraulic engineering and research, madrid, pp. 268-273. fa n s., la k s h m i n a r a y a n a b. a n d ba r n e t t m. (1993) low-reynolds number k – ε model for a steady turbulent boundary layers flows aiaa journal, 31, pp. 1777-1784. kean j.w., smith j.d. (2004) flow and boundary shear stress in channels with woody bank vegetation in bennet s.j. and simon a. (eds), riparian vegetation and fluvial geomorphology. american geophysical union, washington, dc, pp. 237252. kean j.w., smith j.d. (2006) form drag in rivers due to small scale natural topographic features: 1) regular sequences j. geophys. res., 111, f04009, doi: 10.1029/2006jf000467. kn i g h t d., de m e t r i o u j.d., ha m e d m.e., (1984) boundary shear in smooth rectangular channels j. hydraul. eng. 110, pp. 405-422. jones w.p., launder b.e. (1972) the prediction of two 226 fig.10a universal turbulent velocities comparison confronto tra le velocità turb. adimensionali fig.10b universal turb. velocities comparison in the visc. layer confronto tra le velocità turb. adimensionali nella zona viscosa fig.10.c turbulent and input velocities profile comparison confronto tra la velocità analitica, numerica e di input a. pasculli laminarization with a two equation model of turbul e n c e int. j. heat mass transfer 1 5, pp. 301314. iliopoulos i., mito y., hanratty t., et al., (2003) a stochastic model for solid particle dispersion in a nonhomogeneous turbulent field int. j. of multiphase flow 29, 375-394 launder b.e., jones w.p. (1972) mathematical models of turbulence academic press, new york lane s.n., bradbrook k.f., richards k.s., et al., (2000) secondary circulation cells in river channel confluences: measurement artefacts or coherent flow structures hydrol. process. 14, pp. 2047-2071. li c., mosyak a., hetsroni g. (1999) direct numerical simulation of particle-turbulence interaction int. j. of multiphase flow 25, pp. 187-200. nithiarasu p., liu c.b. (2006) an artificial compressibility based characteristic based split (cbs) scheme for steady and unsteady turbulent incompressible flows comput. methods appl. mech. and engrg. 195, pp. 2961-2962. ni t h i a r a s u p., zi e n k i e w i c z o.c. (2006) analysis of an explicit and matrix free fractional step method for incompressible flows comput. methods appl. mech. and engrg. 195, pp. 5537-5551. nithiarasu p., codina r., zienkiewicz o.c. (2006) the characteristic based split (cbs) scheme a unified approach to fluid dynamics int. journal for numerical methods in engrg. 66, pp. 1514-1546. pa s c u l l i a. & sc i a r r a n. (2007) a 2d numerical modelling of watery debris flow including a statistical determination of the local erosion 1s t american landslide conference, vail, colarado (usa) june 3-10, 2007. pasculli a. & sciarra n. (2006) a probabilistic approach to determine the local erosion of a watery debris flow int. ass. for mathematical geology xith international congress. liege september, 3th8th, 2006 (paper s08-08). po s c h e l t., sc h w a g e r t. (2005) c o m p u t a t i o n a l granular dynamics, models and algorithms springer berlin heidelberg new york. qu é m é r e p., & sa g a u t p. (2002) zonal multi-domain rans/les simulations of turbulent flows int. j. numer. meth. fluids 40; pp. 903-925. rinaldi m. & darby s.e. (2008) modelling river-bankerosion processes and mass failure mechanisms: progress towards fully coupled simulations gravel bed rivers vi: from process understanding to river restoration. h.habersack, h.piégay, m. rinaldi editors. elsevier b.v. ro d i w., fe r z i g e r j.h., br e u r m., po r q u i é m. (1997) status of large eddy simulation: results of a w o r k s h o p transaction of the asme 1 1 9, pp. 248-262. ro s a t t i g., fr a c c a r o l o l. (2006) a well balanced approach for flows over mobile bed with high sediment transport journal of computational physics 220, pp. 312-338. sa g a u t p. (2002) large-eddy simulation for incompressible flows springer berlin. so u l i m., zo l e s i o j.p. (2001) arbitrary lagrangianeulerian and free surface methods in fluid mechanics comput. methods appl. mech. engrg. 191, pp. 451-466. si m o n s d.b., se n t ü r k f. (1977) sediment transport technology water resources publications, fort collins, co. schmeeckle m.w. & nelson j.m. (2003) direct numerical simulation of bedload transport using a local, dynamic boundary condition sedimentology, 50, pp. 279-301. warner j.c., sherwood c.r., arango h.g., signell r.p. (2005) performance of four turbulence closure models implemented using a generic length scale method ocean modelling 8, pp. 81-113. xu x. & ha r a d a k. (2003) automatic surface reconstruction with alpha-shape method visual computer 19, pp. 431-443. zi e n k i e w i c z o.c., ta y l o r r.l. & ni t h i a r a s u p. (2006) finite element method for fluid dynamics elsevier, 6thedition. zo h d i t.i. (2007) computational of strongly coupled multifield interaction in particle-fluid systems comput. methods appl. mech engrg. 1 9 6, pp. 3927-3950. 227 ms. ricevuto il 15 marzo 2008 testo definitivo ricevuto il 29 maggio 2008 ms. received: march 28, 2008 final text received: may 29, 2008 cfd-fem 2d modelling of a local ... sess 1_160211.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 on the relation between extensive peat bed and climate fluctuation during the last glacial in venice massimo zecchin1, mauro caffau1 & luigi tosi2 1istituto nazionale di oceanografia e di geofisica sperimentale – ogs, borgo grotta gigante 42/c, 34010 sgonico (ts), italy 2istituto di scienze marine – consiglio nazionale delle ricerche, arsenale tesa 104, castello 2737/f, 30122 venezia, italy corresponding author: m. zecchin <mzecchin@ogs.trieste.it> abstract: zecchin m. et al., on the relation between extensive peat bed and climate fluctuation during the last glacial in venice. (it issn 0394-3356, 2011) core and seismic data from the venice lagoon area allow a detailed investigation of the late pleistocene continental succession accumulated during the last glacial. these deposits consist of an aggrading alluvial plain, some tens of metres thick, which is locally incised by river channels, while both patchy and continuous peat layers complete the succession. one of these peat layers (p1), up to 1 m thick, is well recognizable in the whole lagoon area in both cores and seismic lines. 14c datings of p1 reveal an age ranging between 22 and 24 cal ka b.p., confirming its lateral continuity. all these elements suggest that p1 developed after an episode of marked moisture and large scale cut-off of terrigenous sediment, probably due to enhanced arboreal vegetation cover, leading to the establishment of generalized paludal conditions during the laugerie interstadial. the present evidence may integrate the current knowledge to establish a correlation between cycles recorded in fully continental deposits and those recognizable in ice cores and marine successions. riassunto: zecchin m. et al., sulla relazione tra un esteso livello di torba e variazione climatica durante l’ultimo glaciale a venezia. (it issn 0394-3356, 2011) dati sismici e di carota dall’area della laguna di venezia permettono uno studio dettagliato della successione continentale tardo pleistocenica accumulatasi durante l’ultimo glaciale. questi depositi consistono in una piana alluvionale aggradante, spessa alcune decine di metri, che localmente è incisa da canali fluviali, mentre livelli di torba sia continui che discontinui completano la successione. uno di questi livelli di torba (p1), spesso fino ad 1 m, è ben riconoscibile nell’intera area lagunare sia con carote che con linee sismiche. datazioni con 14c del livello p1 rivelano un’età compresa tra 22 e 24 ka b.p. calibrati, confermando la sua continuità laterale. tutti questi elementi suggeriscono che il livello p1 si sia sviluppato in seguito ad un episodio marcatamente umido accompagnato da una diminuzione di apporto sedimentario a larga scala, probabilmente dovuta ad un aumento della copertura arborea, che ha dato luogo all’instaurarsi di generalizzate condizioni palustri durante l’interstadiale laugerie. la presente evidenza può integrare l’odierna conoscenza per stabilire una correlazione tra cicli registrati in depositi continentali e quelli registrati in carote di ghiaccio ed in successioni marine. key words: interstadial, peat, venice parole chiave: interstadiale, torba, venezia the present study is aimed to recognize the signature of climate shifts related to the younger stadial and interstadial phases in the late pleistocene continental succession of the venice area. relatively high sediment supply and regional subsidence favoured the accumulation of several tens of metres of continental deposits. the present setting allowed changes in sedimentation style due to glacial advancements and retreats to be recorder in the succession. our objective is therefore to highlight features directly associated to shifts from stadials to interstadials and vice-versa, with particular reference to that occurred across the laugerie interstadial (de heinzelin, 1961; leroi-gouhran, 1980). such a brief phase of climate improvement, having a conventional 14c age of 19.2 ka b.p. (serandrei-barbero et al., 2005), was originally defined in french continental deposits. five cores drilled in the framework of the carg project, i.e. ismar-1l, ismar-2l, ismar-3l, ogs-1 and ogs-7, were selected for a detailed investigation along the pleistocene interval. seismic data have been acquired in the southern venice lagoon within the corila sub-project 3.16, which implemented a very high-resolution (vhr) seismic system adapted for the very shallow water, i.e. less than 1 m depth. both vhr seismic profiles and core data allow to investigate down to 30 m in the late pleistocene to holocene sediments of the study area. this succession exhibits a suite of fully continental facies represented by fluvial channel and floodplain deposits, and by swamp sediments consisting of peat layers. floodplain deposits are volumetrically the most abundant, and they consist 69 70 70 ms. received: testo ricevuto il of clayey silt to fine-grained sand containing pulmonata gastropods and their opercula, oogons of characeae, seeds, plant remnants, and locally abundant root traces. peat beds are up to 0.3 m thick, yet they may be grouped to form up to 1 m thick intervals separated by silty and sandy layers. peats developed in vegetated swamps receiving scarce sedimentation and located in extensive interfluves. fluvial channel fills are up to 10 m thick and 500 m wide, and in seismic profiles locally show lateral accretion highlighted by welldeveloped clinoforms. the fill consists of mediumgrained sand to silty sand showing a characteristic fining-upward trend. metre-scale laminated silty clay to silty sand containing pulmonata gastropods, oogons of characeae, seeds and plant remnants are locally found, and they have been interpreted as levee deposits. a well-developed peat layer, locally forming a composite interval up to 1m thick, is recognizable in the whole venice lagoon area from 10 m below the lagoon floor in the northern sector to 19 m in the southern one, and is lacking only where it has been truncated by fluvial channels. the correlation of p1 in the whole venice area is sustained by 14c datings, showing an age ranging between 22 and 24 cal ka b.p. the occurrence of a regionally extensive peat layer having a conventional age of ca. 19 ka b.p. was already noted by correggiari et al. (1996) in cores from the adriatic shelf in front of the venice lagoon. peat layers may result by local processes of river avulsion producing sheltered wetlands (e.g. miola et al., 2006), as well as by larger scale controls such as climate changes. other possible factors producing wetlands include a decrease of terrigenous supply from the hinterland and the lack of meltwater drainage due to the presence of permafrost (ravazzi, 2006). for its extensive development, covering an area exceeding that of the venice lagoon, a genesis of p1 related to local river meander shifting should be ruled out, and therefore a linkage with large scale controls is inferred. in particular, as pollen data by canali et al. (2007) revealed that interstadial periods were characterized by an increased arboreal vegetation, probably preventing a significant terrigenous supply, swamps characterized by peat accumulation developed. the correlation between phases of climate improvement and peat formation is reinforced by the determined age of p1, witch fit well with that of the laugerie interstadial. such a correlation is generally considered valid also for northern european sites (see fletcher et al., 2010 and references therein). present data, therefore, suggest that in the venetian area, late pleistocene laterally extensive peat layers tended to develop during phases of climate improvements (i.e. interstadials) due to increased arboreal vegetation cover, which promoted a marked decrease of terrigenous supply from the hinterland. in contrast, active floodplain aggradation occurred during stadial phases, characterized by intense fluvioglacial activity and by a less pronounced vegetation cover. the present results may be very useful to the development of a clearer picture on environmental changes related to climate oscillations during the last glacial at middle latitudes, as well as their linkage with records from ice cores and marine sequences. acknowledgements this work was developed in the framework of the following researches: corila “sub-project 3.16, vhrs”; venice water authority-corila “subactivity 2, shallow”; vector “action 3, work package 5, cliven”. thanks to carg project funded by ispra (formerly apat) and by regione del veneto for the provided sediment cores. references canali g., capraro l., donnici s., rizzetto f., serandrei-barbero r. & tosi l. (2007) vegetational and environmental changes in the eastern venetian coastal plain (northern italy) over the past 80,000 years. palaeogeogr., palaeoclimat., palaeoecol., 253, 300-316. correggiari a., field m.e. & trincardi f. (1996) late quaternary transgressive large dunes on the sediment-starved adriatic shelf. in: m. de batist and p. jacobs (eds.) geology of siliciclastic shelf seas. geol. soc. london sp. publ., 117, 155-169. de heinzelin j. (1961) more on upper palaeolithic archaeology. current anthropol., 5, 434-436. fletcher w.j. et al., (2010) millennial-scale variability during the last glacial in vegetation records from europe. quat. sci. rev., 29, 2839-2864. leroi-gourhan a. (1980) interstades wiirmiens: laugerie et lescaux. bull. ass. franç. etude quat., 3, 95-100. miola a., bondesan a., corain l., favaretto s., mozzi p., piovan s. & sostizzo i. (2006) wetlands in the venice po plain (northeastern italy) during the last glacial maximum: interplay between vegetation, hydrology and sedimentary environment. rev. palaeobot. palyn., 141, 53-81. ravazzi c. (2006) comment on “paleoclimatic record of the past 22,000 years in venice (northern italy): biostratigraphic evidence and chronology” by serandrei barbero et al. [quaternary international 140-141, 3752]. “interstadials” or phases of accumulation of reworked pollen? quat. int., 148, 165-167. serandrei-barbero r. et al., (2005) paleoclimatic record of the past 22,000 years in venice (northern italy): biostratigraphic evidence and chronology. quat. int., 140/141, 37-52. m. zecchin et al. january 15, 2011 15 gennaio 2011 impaginato atti ccoonnffrroonnttoo ttrraa iinnffoorrmmaazziioonnii ggeeoollooggiicchhee ee ppeeddoollooggiicchhee ssuull ccoonnooiiddee ddeell cceelllliinnaa ((ffrriiuullii,, iittaalliiaa)) rr.. aavviigglliiaannoo11,, gg.. mmoonneeggaattoo11,, ss.. zzaannoollllaa22,, gg.. mmiicchheelluuttttii22 && pp.. mmoozzzzii33 1università degli studi di udine, dipartimento di georisorse e territorio 2ersa, ente regionale per lo sviluppo e la promozione dell’agricoltura del friuli-venezia giulia, ufficio del suolo 3università degli studi di padova, dipartimento di geografia riassunto su un conoide terrazzato sono state analizzate le caratteristiche dei suoli sviluppatisi su ordini di terrazzi attribuibili ad età diverse, sui quali è stata testata l'applicabilità degli indici chimici proposti in letteratura per la datazione relativa dei suoli. i depositi alluvionali del conoide del cellina sono costituiti esclusivamente da clasti di rocce sedimentarie con prevalenza di litotipi calcareo-dolomitici rispetto a quelli terrigeni; l’evoluzione geomorfologica è stata influenzata sia dal contesto tettonico, sia dalle variazioni nel tempo dei fattori che controllano il regime delle portate solide e liquide del corso d’acqua. sono stati confrontati sette suoli rappresentativi ubicati sulla superficie del conoide ed un suolo sepolto rinvenuto in prossimità dell’alveo attuale sotto una coltre sedimentaria di circa 30 m. il grado di pedogenesi dei suoli ed una stima sommaria della loro età sono stati valutati anche utilizzando due indici relativi alle diverse forme di ferro presenti, estratte in ossalato e ditionito-citrato: l’air (feo/fed) e l’arduino ((fed-feo)/fetot). il rapporto fra forme di ferro libero ed il ferro totale non ha tuttavia portato ad una migliore comprensione della cronostratigrafia dei corpi sedimentari, in quanto nella peculiarità sedimentologica di questo ambiente il ferro totale misurato sulla terra fine rappresenta già una concentrazione residuale dovuta all’alterazione, come viene evidenziato sia dal suo aumentare con l’età presunta, sia dal suo diminuire negli orizzonti non pedogenizzati. summary seven soils located on terraces of different ages of an alluvial fan in north-eastern italy have been compared in terms of their morphology and degree of development. alluvial deposits deriving from calcareous-dolomitic rocks, with subordinated terrigenous rocks, always represent the parent material. there are no crystalline rocks outcrops in the mountain basin. the geomorphological evolution of the alluvial fan has been strictly controlled both by the still active tectonics of the area and by the long-term variability of climatic factors. one (profile f) is located on the holocene fan and presents a low degree of development, two, profiles c and e, are on the main surface of the pleistocene fan, dated 10530 ± 100 ybp, conventional 14c age. the different degree of development is probably due to the difference in parent material, very coarse gravel with boulders in profile c, gravel in profile e. profile d is on a higher terrace, but is similar to those on the main surface. profiles g and b are located on small portions of terraces, probably in a tectonics-affected position, at the very border of the alluvial plain. profile h is a buried soil, outcropping under a 30m thick gravel deposit. extractable iron ratios have also been considered in order to determine whether they are affected by their relative ages. free ironoxide/total-iron ratios, according to the air and arduino methods, gave unattended results. it has not been possible to recognise a trend with the increasing age and the range of values obtained is much greater than those known by literature. a possible explanation is in the peculiar characteristics of the area, where even the content of total-iron alone offers a trend of development, as can be evinced by its increasing with relative age and decreasing with depth. parole chiave: ferro libero; geologia del quaternario; conoide alluvionale; torrente cellina; friuli key-words: free iron; quaternary geology; alluvial fan; cellina river; friuli il quaternario italian journal of quaternary sciences 1155(1), 2002, 99-104 11.. iinnttrroodduuzziioonnee in geologia per l’analisi stratigrafica dei depositi quaternari continentali vengono sempre più diffusamente utilizzate le uunniittàà aalllloossttrraattiiggrraaffiicchhee (“corpi di rocce sedimentarie cartografabili, definiti e identificati sulla base delle discontinuità che li delimitano”, north american commission on stratigraphic nomenclature, 1983). le discontinuità che delimitano i corpi sedimentari possono essere di varia natura, in ogni caso rappresentano lacune temporali (mancata sedimentazione per periodi di tempo più o meno lunghi) e/o sedimentarie (superfici erosive). i corpi geologici compresi tra discontinuità di rango superiore e con estensione regionale di regola appartengono a cicli sedimentari che possono essere legati a importanti variazioni climatiche e a particolari fasi di evoluzione tettonica dell’area. nelle serie sedimentarie di ambiente continentale il rango gerarchico tra le discontinuità, superficiali o sepolte, legate a lacune temporali dipende dalla durata del periodo di mancata sedimentazione e dalla loro estensione, esso è quindi intimamente connesso alle caratteristiche dei suoli che possono essere ad esse associati. da questa premessa diventa evidente che l’analisi di suoli superficiali e sepolti fornisce indicazioni importanti per definire la gerarchia e l’estensione delle discontinuità, nonché la geometria dei corpi sedimentari. per quanto riguarda i corpi sedimentari superficiali affioranti, la loro età relativa è ricavata prevalentemente da evidenze geomorfologiche, stratigrafiche e dal grado di alterazione pedogenetica delle loro superfici limite superiori. nel caso in cui le superfici pedogenizzate siano svincolate dal contesto geomorfologico e stratigrafico originario (lembi isolati di terrazzi fluviali, evidenze sporadiche di suoli sepolti), diventa di fondamentale importanza la correlazione tra suoli osservati in contesti diversi per la ricostruzione delle morfologie originali e dei rapporti tra i corpi sedimentari. in questo lavoro si analizzano alcuni suoli, sia superficiali che sepolti, sviluppatisi su depositi alluvionali del torrente cellina (alta pianura pordenonese) tentando di confrontare le osservazioni pedologiche “di routine” effettuate nel corso di un rilevamento finalizzato alla cartografia dei suoli, con le caratteristiche chimiche dei suoli e con dati di tipo geomorfologico e geologico stratigrafico. per alcuni suoli il ritrovamento di sedimenti organici vegetali ha consentito di definire l’età 14c convenzionale dei depositi sui quali si sono sviluppati, per altri non si hanno elementi di datazione dei depositi per cui si fa riferimento solo ad una cronologia relativa. oltre all'osservazione delle caratteristiche morfologiche dei suoli, si è voluto testare l'applicabilità all’ambiente in esame degli indici chimici proposti in letteratura per la datazione relativa dei suoli. in pratica questi indici si propongono di confrontare il contenuto di ferro libero con il ferro totale, dove il primo costituisce il ferro liberato dalla pedogenesi ed il secondo l’ammontare fra questo e quello legato al reticolo dei silicati. questo approccio interdisciplinare è stato possibile grazie alla collaborazione tra il dipartimento di georisorse e territorio dell'università di udine e l’ersa del friuli-venezia giulia nell'ambito dei rispettivi progetti carg fvg (nuova cartografia geologica nazionale in fvg) e sols (banca dati georeferenziata dei suoli della pianura e delle colline del fvg), con la partecipazione del dipartimento di geografia dell'università di padova. 22.. iinnqquuaaddrraammeennttoo ggeeoollooggiiccoo ee ggeeoommoorrffoollooggiiccoo il conoide alluvionale del torrente cellina è originato dalle divagazioni del corso d’acqua al suo sbocco nella pianura veneto friulana. esso si sviluppa al limite tra le prealpi carniche pordenonesi, nelle quali si espande il suo bacino imbrifero, e la pianura prospiciente il mare adriatico (fig.1). l’evoluzione geomorfologica del conoide su ambiti temporali medio-lunghi è presumibilmente influenzata 100 r. avigliano et al. fig. 1 schema geomorfologico della pianura friulana occidentale (da stefanini & cucchi, 1978, mod.). geomorphological sketch of the western friuli plain (from stefanini & cucchi, 1978, mod.). 101confronto tra informazioni geologiche ... da un lato dal generale contesto tettonico in cui è inserito, dall'altro dalle variazioni nel tempo dei fattori prevalentemente climatici che hanno controllato il regime delle portate solide e liquide del corso d’acqua. il margine meridionale dei rilievi alpini assume qui un andamento ne-sw, condizionato dalla presenza di importanti strutture tettoniche di uguale direzione. il sollevamento di questa porzione di catena ha fatto sì che in pianura, già in prossimità dell’apice del conoide, i depositi alluvionali che ricoprono il substrato prequaternario posto ai piedi del thrust abbiano spessori di alcune centinaia di metri e che lembi di depositi fluviali siano rimasti isolati sui versanti dei rilievi prospicienti la pianura. a due di questi lembi si riferiscono i pprrooffiillii bb (terrazzo di aviano) e gg (terrazzo di maniago libero) sospesi rispettivamente di circa 10 e 30 m sulla superficie del conoide tardo-pleistocenico (comel, 1956; avigliano et al., 2001). le superfici di questi terrazzi possono aver subito, nel tempo, un rimodellamento anche molto spinto; tuttavia i suoli sviluppatisi su di essi sono decisamente più evoluti rispetto a quelli del conoide più recente e eventuali superfici a loro omologhe in pianura vanno ricercate all'interno del materasso alluvionale. i depositi alluvionali recenti e antichi osservati nella zona apicale del conoide sono simili, trattandosi prevalentemente di ghiaie a ciottoli e blocchi clastosostenuti con matrice sabbiosa, massive o a stratificazione grossolana, che possono essere cementati nel caso dei sedimenti più antichi. verso l'unghia del conoide diminuiscono gradualmente le dimensioni dei clasti, i depositi sono sciolti, meglio classati ed assumono una stratificazione orizzontale e inclinata ben definita fino a diventare comune la presenza di corpi prevalentemente sabbiosi. la litologia dei depositi alluvionali costituenti il conoide riflette quella delle rocce affioranti nel bacino montano del cellina che sono esclusivamente sedimentarie con netta prevalenza delle calcareo dolomitiche sulle terrigene, mentre mancano totalmente le rocce cristalline. il conoide del cellina risulta formato da un “conoide principale”, costituito da un insieme di costruzioni coalescenti aventi apice comune. la superficie del conoide è rimasta in evoluzione almeno fino al termine del pleistocene superiore come sembrano confermare alcune datazioni radiometriche effettuate con il metodo del radiocarbonio su sedimenti organici campionati in prossimità di essa (maniago: 11850 ± 110 ybp; basaldella di vivaro: 10530 ± 100 ybp età 14c non calibrate. avigliano et al., 2001). sulla superficie del conoide principale sono stati osservati i pprrooffiillii cc,, ee e dd, quest’ultimo situato su un terrazzo convergente (riva di bares) presente sul margine nw del conoide e che ne rappresenta probabilmente la porzione più antica. a partire dal passaggio tra pleistocene e olocene, nel tratto apicale del conoide principale, l’erosione ha incominciato a prevalere sulla deposizione. durante l’olocene la tendenza erosiva del corso d’acqua in questo settore sembra essere stata continua e si è accompagnata alla migrazione verso sud dell’area di sedimentazione con conseguente formazione di un “conoide telescopico” che si sovrappone all’unghia del conoide principale e su cui è stato osservato il pprrooffiilloo ff. durante la fase di incisione il cellina ha progressivamente spostato verso ovest il suo asse, come testimoniato dalla serie di terrazzi di erosione convergenti presenti sull’ala sinistra del conoide. fig. 2 sezione schematica del conoide del t.cellina in località del ponte del giulio, in corrispondenza dell’affioramento del paleosuolo descritto nel profilo h. schematic section of the river cellina fan with the palaeosoil outcrop (profile h). 102 r. avigliano et al. attualmente il corso d'acqua incide l’apice del conoide principale con scarpate che arrivano ai 40 m di altezza. a montereale valcellina, in località ponte del giulio, il cellina incide il conoide per circa 30 m. in corrispondenza del greto l'erosione ha esumato un suolo sepolto ben sviluppato (pprrooffiilloo hh) che testimonia una importante lacuna sedimentaria in questo settore della pianura precedentemente all'ultima fase di aggradazione (fig. 2). si ritiene che la formazione del suolo sia collegata ad una situazione morfologica simile a quella attuale, in cui la pianura era terrazzata ed il corso d’acqua scorreva incassato all’interno di un’incisione. per il momento non sono chiari i rapporti tra il suolo del ponte del giulio e quelli sviluppatisi sui depositi tettonizzati (pprrooffiillii bb e gg), nonché quali siano stati i fattori che hanno maggiormente influito sul presunto antico approfondimento del corso d'acqua e che stanno quindi all'origine della lacuna sedimentaria (fattori climatici, tettonici o entrambi). 33.. ii ssuuoollii nell ’area oggetto di studio sono stati scelti, tra quelli effettuati nell’ambito del progetto sols, i profili di sette suoli rappresentativi per inquadrarne le caratteristiche e confrontare il loro grado di sviluppo (fig 3). le osservazioni hanno confermato la presenza di suoli più sviluppati sulle superfici supposte più antiche (terrazzi di aviano e maniago libero), con lisciviazione dei carbonati ed illuviazione di argilla negli orizzonti profondi (pprrooffii-llii bb e gg). la superficie del conoide principale tardo pleistocenico è invece contraddistinta da suoli mediamente poco sviluppati (pprrooffiilloo cc), le cui caratteristiche appaiono condizionate più dalla natura essenzialmente carbonatica e dalla granulometria del materiale di partenza che dalla loro età. infatti il pprrooffiilloo dd, ubicato sulla porzione di conoide supposta più antica, non presenta grandi differenze rispetto al pprrooffiilloo cc, mentre, all’interno della stessa fig. 3 carta dei sottosistemi di terre ed ubicazione dei profili. land subsystem map and profile location. iidd ccoommuunnee qquuoottaa ppaaeessaaggggiioo uussddaa ((11999988)) wwrrbb ((11999988)) pprrooffiilloo mmssllmm bb aviano 155 terrazzo fluviale typic cutani-chromic tettonizzato hapludalf luvisol cc montereale 238 superficie modale typic skeleti-rendzic valc. del conoide haprendoll leptosol pleistocenico dd aviano 227 terrazzo fluviale rendollic skeleti-calcaric eutrudept cambisol ee s. quirino 116 superficie modale rendollic skeleti-calcaric del conoide eutrudept cambisol pleistocenico ff s. quirino 131 superficie modale typic skeleti-calcaric del conoide udorthent regosol olocenico gg maniago 350 terrazzo fluviale spodic hyperdistritettonizzato paleudult profondic alisol hh montereale 241 suolo sepolto typic cutanic luvisol valc. hapludalf tab. 1 classificazione dei suoli. soil classification. unità di paesaggio, i suoli impostati su sedimenti più fini presentano un grado di sviluppo maggiormente accentuato (pprrooffiilloo ee). infine, è stato considerato un suolo impostato su una superficie di deposizione recente, che ha messo in luce come l’instaurarsi della pedogenesi sia estremamente lento (pprrooffiilloo ff). le caratteristiche delle diverse tipologie di suolo sono state confrontate con quelle di un suolo sepolto (pprrooffiilloo hh) rinvenuto nell’alveo 103confronto tra informazioni geologiche ... attuale del torrente cellina nell’ambito dei rilevamenti carg, evidenziando come questo presenti delle analogie con quelli rilevati sui terrazzi di aviano e di maniago libero. 44.. iinnddiiccii cchhiimmiiccii ppeerr llaa ddaattaazziioonnee rreellaattiivvaa ddeeii ssuuoollii il grado di pedogenesi dei suoli ed una stima sommaria della loro età sono stati valutati utilizzando due indici: l’air (torrent et al., 1980) e l’arduino (arduino et al., 1984) tramite la determinazione delle diverse forme del ferro (totale, ossalato, ditionito-citrato), estratte in accordo con i metodi ufficiali (ministero delle risorse agricole, alimentari e forestali, 1994). l’air (active iron ratio) è definito dal rapporto tra il ferro estratto in ossalato e quello estratto in ditionitocitrato (feo/fed) e dovrebbe decrescere con l’aumentare del grado di alterazione del parent material. l’indice di arduino ((fed-feo)/fetot), espresso in percentuale, dovrebbe invece aumentare con l’età supposta del suolo. l’estrazione è stata effettuata su ciascuno degli orizzonti riconosciuti nel profilo, ed ha evidenziato come il tenore in ferro tenda a diminuire con la profondità, ad eccezione dei suoli con un orizzonte b ben sviluppato, dove generalmente il valore si mantiene costante o tende ad aumentare rispetto agli orizzonti sovrastanti. per ciascun profilo è stato identificato un orizzonte significativo del grado di pedogenesi raggiunta, corrispondente ad un b per i profili maggiormente sviluppati, all’ a negli altri casi, che è stato successivamente messo a confronto con gli altri. 55.. ccoonncclluussiioonnii l’applicazione degli indici arduino e air non ha fornito i risultati attesi (fig. 4). l’analisi dei dati evidenzia che non solo non è presente un trend riconoscibile, ma anche che l’intervallo di variabilità osservato è più ampio di quello riscontrato da altri autori per lo stesso intervallo di tempo (arduino et al., 1983; bini e mondini, 1992). ritenendo che il materiale parentale dei diversi suoli presenti un buon grado di uniformità litologica, l’origine di questa discrepanza sembra risiedere nel diverso contenuto in ferro totale posseduto dai campioni di terra fine (frazione < 2mm) analizzati. considerando invece il contenuto di ferro totale nei confronti dell’età presunta si evidenzia invece un trend ben marcato, dove esso tende ad aumentare con l’età. un andamento analogo si riscontra anche per il contenuto di ferro estratto in ossalato e in ditionito-citrato, entrambi indice del grado di alterazione a parità di contenuto di ferro totale nel materiale parentale (fig. 5). essendo il ferro un costituente accessorio delle alluvioni grossolane prevalentemente calcareo-dolomitiche del cellina, il rapporto fra forme di ferro libero ed il ferro totale non porta a risultati significativi, in quanto il ferro totale misurato sulla terra fine rappresenta già di per sé una concentrazione residuale dovuta all’alterazione. ciò è suffragato dal fatto che il tenore in ferro totale è minore negli orizzonti c rispetto a quelli pedogenizzati. non è tuttavia ancora possibile, sulla base dei dati disponibili, tracciare l’andamento di una curva sperimentale rispetto al tempo e stabilire pertanto i rapporti che intercorrono tra le superfici su cui sono ubicati i profili b, g ed h. profilo scheletro % sabbia % limo % argilla % ph in acqua carbonati carbonio ffeerrrroo iinn ffeerrrroo iinn ffeerrrroo v/v (2000-50 (50-2 (<2 um) totali % organico oossssaallaattoo ddiittiioonniittoo ttoottaallee um) um) % gg//kkgg gg//kkgg gg//kkgg bb 3 8,1 18,0 73,9 7,6 1 0,5 44,,55 2277,,11 5522,,22 cc 63 37,4 56,3 6,3 8,0 64 3,0 11,,88 1111,,99 1122,,22 dd 36 30,2 49,2 20,5 8,1 35 1,9 22,,00 1166,,88 2244,,22 ee 64 31,8 38,7 29,5 7,9 45 1,2 11,,33 1177,,55 2299,,44 ff 58 61,0 34,7 4,4 7,6 92 1,8 00,,55 22,,88 33,,88 gg 18 5,0 22,1 72,9 5,3 0 0,3 33,,66 2288,,99 5588,,88 hh 7 16,6 12,0 71,3 8,0 0 0,4 44,,44 2255,,99 5544,,22 tab. 2 dati analitici relativi agli orizzonti considerati. analytic data of the selected horizons. fig. 4 indici di arduino e air. arduino and air indexes. bbiibblliiooggrraaffiiaa aa. vv. (1994) – metodi ufficiali di analisi chimica del suolo. osservatorio nazionale pedologico e per la qualità del suolo, ministero delle risorse agricole, alimentari e forestali, roma. aa. vv. (1998). keys to soil taxonomy, eight edition, united states departement of agriculture, natural resources conservation service. aa. vv. (1998). world reference base for soil resources, fao, isric and isss. arduino e., barberis e., carraro f. forno m. g. (1984) – estimating relative ages from iron-oxide/total iron ratios of soils in the western po valley, italy. geoderma, 3333 p. 39-52, elsevier science publishers b. v. amsterdam. avigliano r., calderoni g., monegato g. mozzi p. (2001) – the late pleistocene-holocene evolution of the cellina and meduna alluvial fans. atti dell'80ª riunione estiva della sgi. memorie della società geologica italiana. (in stampa) bini c., mondini c. (1992) – deep weathering features in paleosols from alluvial deposits (“terra rossa”like) in the friuli piedmont area (italy). miner. petrogr. acta, vvooll.. xxxxxxvv, 1-21. comel a. (1956) monografia sui terreni della pianura friulana. iii. genesi della pianura occidentale costruita dal meduna, dal cellina e da corsi d'acqua minori. n. ann. ist. chim. agr. sperim. gorizia, 7: p. 5-93, gorizia. mondini c., bini c. ciet p., paronuzzi p., spadea p. (1991) – clay mineralogy of a soil chronosequence in the friuli piedmont area. proc7th euroclay conf. dresden ’91, greiswald 779-784. north american commission on stratigraphic nomenclature (1983) north american stratigraphic code. the american association of petroleum geologists bullettin, 6677((55)): p. 841-875, tulsa. stefanini s. & cucchi s. (1978) gli acquiferi del sottosuolo della pianura veneta fra i fiumi piave e tagliamento. c.n.r., quaderni dell'ist. di ric. sulle acque, 3344 ((1122)): p. 287-299. torrent j., schwertmann u. and schulze d.j. (1980) iron oxide mineralogy of some soils of two river terrace sequences in spain. geoderma 2233,, 191208. 104 r. avigliano et al. fig. 5 valori di ferro estraibile. extractable iron. ms. ricevuto marzo 2002 ms. received: march 2002 imp.d'orefice& le eolianiti dell’isola d’elba: i depositi del promontorio del m. calamita e del golfo di viticcio maurizio d’orefice, roberto graciotti & flavio capitanio apat – servizio geologico d’italia/dipartimento difesa del suolo – via curtatone, 3 00185 roma. (e-mail: maurizio.dorefice@apat.it, roberto.graciotti@apat.it, flavio.capitanio@apat.it) riassunto: m. d’orefice et al., le eolianiti dell’isola d’elba: i depositi del promontorio del m. calamita e del golfo di viticcio. (it issn 0394-3356, 2007). nel presente lavoro vengono descritti alcuni depositi eolici affioranti nel tratto di costa occidentale del promontorio del m. calamita (settore sud-orientale dell’isola d’elba) e nel golfo di viticcio (settore centro-settentrionale dell’isola). i depositi eolici poggiano in discordanza sulle antiche coste rocciose modellate nel substrato, rinvenendosi finanche all’interno delle preesistenti valli fluviali, a volte oltre i 100 m di quota s.l.m. le eolianiti sono costituite prevalentemente da sabbie medio-grossolane ed in misura minore da ghiaie minute. la tessitura è openwork; tuttavia la maggior parte dei vuoti intergranulari è riempita da due generazioni di cemento carbonatico, che in alcuni casi rendono la tessitura cemento-sostenuta. al loro interno, le eolianiti sono caratterizzate da evidenti strutture sedimentarie, che consistono essenzialmente in stratificazione incrociata a grande scala, di tipo piana-tabulare. in essa prevalgono i set di strati frontali ad alto angolo, che hanno una forma tangenziale ed un’immersione generalmente verso terra. i singoli set di strati, interessati internamente da numerose superfici di riattivazione, sono troncati da superfici d’erosione, a basso angolo, immergenti verso mare. i depositi eolici, inoltre, sono contraddistinti da strutture sedimentarie secondarie, rappresentate da concrezioni intrasedimentarie verticali e sub-orizzontali. frequentemente i depositi eolici sono intercalati con paleosuoli rubefatti e con brecce di versante. l’analisi petrografica ha consentito di classificare le eolianiti come quarzo-areniti bioclastiche. esse, infatti, annoverano tra i costituenti principali bioclasti carbonatici, clasti silicatici e inclusi litici. i bioclasti derivano da frammenti di gusci di lamellibranchi, gasteropodi, echinodermi, briozoi, alghe rosse nodulari e foraminiferi bentonici. i clasti silicatici consistono principalmente in granuli di quarzo e feldspati: l’analisi morfometrica in due dimensioni dei granuli di quarzo suggerisce un certo grado di uniformità tra tutti gli affioramenti studiati, soprattutto per quanto riguarda i parametri di sfericità e d’arrotondamento. gli inclusi litici sono costituiti prevalentemente da frammenti di quarzo-areniti, con subordinate quantità di graniti l.s. e quarziti. i rapporti quantitativi dei litici sono pressoché costanti da un affioramento all’altro e non trovano corrispondenza nella litologia dei rispettivi bacini idrografici di appartenenza. la continuazione dei depositi eolici per diversi metri al di sotto del livello del mare attuale e la loro erosione ad opera dell’odierna dinamica marina, stanno a dimostrare che essi si sono formati nel corso di una fase di basso stazionamento del livello marino. durante questo intervallo di tempo, emergeva progressivamente dal mare un fondo sabbioso, che ha agito come zona d’alimentazione per questi depositi. i risultati delle datazioni con il radiocarbonio sui paleosuoli intercalati ai depositi eolici ed i dati cronologici sui reperti archeologici in essi contenuti, riportati in letteratura, permettono di attribuire le eolianiti in esame ai due stadi freddi dell’ultimo glaciale (stadio isotopico 4 e 2). la loro età è quindi ascrivibile al pleistocene superiore. abstract: m. d’orefice et al., the elba island eolianites: the deposits of the mt. calamita promontory and the viticcio gulf. (it issn 0394-3356, 2007). this paper is focused on some deposits of aeolian origin outcropping in the western coast of the mt. calamita promontory (southeastern sector of the elba island) and in the viticcio gulf (centralnorthern sector of the elba island). the aeolian deposits lie unconformably on the ancient, modeled rocky coasts of the substrate, and also occur inside the pre-existing river valleys, sometimes as far as 100 m a.s.l. the aeolianites are built up mainly by coarse to medium-sized sands and to a lesser extent by fine gravel. they have an open-work fabric; nevertheless, most of intergranular pores are filled by two generations of carbonatic cements, which can make the rock cementsupported. inside the aeolianites, characteristic sedimentary structures are clearly recognizable: they consist essentially in a tabular-planar cross-stratification. high angle foresets dipping landward and tangent to the base level are prevailing. each set is affected internally by several reactivation surfaces, and is truncated by low angle erosional surfaces dipping seaward. the aeolian deposits are also characterized by second-order sedimentary structures, which consist in vertical and sub-horizontal intra-sedimentary calcite-cemented concretions. along the coastline, particularly on the flat coasts, the upper surface of the aeolianites shows peculiar erosional micro-forms, consisting mainly in vertical tubules. also erosional macro-forms are present, such as kamenitza and rock pools. frequently, the aeolian deposits are interbedded with rubefied paleosols and with slope breccias, built up by polygenetic and heterometric angular clasts. petrographical analysis allowed us to classify the eolianites as bioclastic quartz-sandstones. in fact, their main components are carbonate bioclasts, silicate clasts, and lithic fragments. bioclasts derive from shell fragments of lamellibranchs, gastropods, echinoderms, briozoans, nodular red algae, and benthonic foraminifera. these latter mostly account for species belonging to a temperate to warm, intertidal marine paleoenvironment. silicate clasts consist mainly in quartz and feldspar grains, with minor amounts of micas, spinel, hematite, and clinopyroxene. the two-dimension morphometrical analysis performed on quartz grains suggests a certain degree of uniformity among the studied occurrences, in particular with the sphericity and roundness parameters. lithic fragments mostly count quartz-sandstones, along with minor amounts of granitic l.s. and quartzitic rocks. the quantitative ratios of lithics are nearly constant from an outcrop to another, without any correspondence with the lithology of their respective hydrographical basin. dipping of the aeolian deposits under the current sea level, together with their erosion by the present marine dynamics, demonstrate that aeolianites originated during a low standing phase of the sea level. during this time span, a sandy bottom progressively emerged from the sea and acted as a feeding area for these deposits. results of the radiocarbon age measurements performed on some palaeosoils interbedded between the aeolian deposits, along with chronological data on archaeological materials found inside these palaeosoils, as reported in literature, allow us to assign the studied aeolianites to the two cold stages of the last glacial (isotope stage 4 and 2). thus, the age of these deposits can be attributed to the upper pleistocene. parole chiave: depositi eolici, quarzo-areniti bioclastiche, strutture sedimentarie, pleistocene superiore, isola d’elba italia. keywords: aeolian deposits, bioclastic quartz-sandstones, sedimentary structures, upper pleistocene, elba island italy. il quaternario italian journal of quaternary sciences 20(1), 2007 21-44 22 m. d’orefice, r. graciotti & f. capitanio 1. introduzione durante il rilevamento geomorfologico delle isole dell’arcipelago toscano1, sono stati approfonditi alcuni aspetti legati alla geomorfologia ed alla geologia del quaternario di queste isole. in questo ambito, una particolare attenzione è stata rivolta ai depositi eolici, costituiti da areniti quaternarie con stratificazione incrociata, affioranti in più punti della fascia costiera dell’isola d’elba, testimonianze di depositi un tempo ben più estesi lungo le coste elbane (fig. 1). in particolare, come già segnalato da mazzanti (1983), essi si rinvengono tra cala mandriola e cala cancherelli, a viticcio, a scaglieri, nel golfo della biodola, lungo i due versanti del promontorio di capo stella, tra la punta di zuccale e la cala dell’innamorata, in alcune valli ad est di capoliveri e a cavo. a questi depositi, talvolta indicati con il nome di "panchina", è stata attribuita inizialmente un’origine marina (lotti, 1910) e successivamente un’origine eolica (barberi et al., 1969). tuttavia, il termine "panchina" può generare confusione: infatti, esso è stato utilizzato in passato per indicare areniti antiche e recenti, diffuse lungo le coste italiane e studiate con maggiore dettaglio nel litorale tosco-laziale, dove sono state ritenute in alcuni casi di origine marina (a partire dal gioli, 1894) e in altri eolica (a partire dal merciai, 1926). nel presente lavoro vengono illustrati e comparati tra loro i depositi eolici situati lungo la costa occidentale del promontorio del m. calamita (elba sud-orientale) e nel golfo di viticcio (elba centro-settentrionale). questi affioramenti sono stati selezionati sulla base dei seguenti criteri: i) in essi sono conservate le migliori esposizioni di strutture sedimentarie a grande scala; ii) essi appartengono ad aree ubicate in settori opposti dell’isola (promontorio del calamita e golfo di viticcio), contraddistinti da un contesto geomorfologico e litologico differente; iii) il settore del m. calamita studiato comprende tre località contigue (barabarca, stecchi e mad.na delle grazie), relativamente uniformi dal punto di vista geologico e geomorfologico, che consentono di valutare l’eventuale contributo di fattori morfologici locali. per la loro peculiarità e completezza di esposizione, quindi, le areniti esaminate consentono d’incrementare le conoscenze finora disponibili su questo litotipo. il presente lavoro si propone di descrivere, oltre ad alcuni aspetti morfologici, le maggiori strutture sedimentarie interne, nonché le principali caratteristiche mineralogiche e petrografiche delle eolianiti, al fine di contribuire a chiarire la loro origine ed alcune delle vicende evolutive che hanno interessato l’isola d’elba nel tardo-quaternario. 2. inquadramento geologico e petrografico la geologia dell’isola d’elba è molto articolata per la presenza, in uno spazio relativamente ristretto (circa 224 km2), di una notevole varietà di rocce ignee, metamorfiche e sedimentarie caratterizzate da un complesso assetto tettonico, conseguito nel corso di diverse tappe evolutive. in sintesi, l’evoluzione tettonica dell’isola d’elba ha avuto inizio con l’orogenesi varisica, che ha interessato le unità più profonde dell’edificio strutturale elbano ed in particolare il complesso metamorfico di m. calamita (garfagnoli et al., 2005) e l’unità di ortano (pandeli & puxeddu, 1990). nel corso della chiusura dell’oceano ligurepiemontese, verificatasi tra il cretacico superiore e l’eocene, è avvenuta la deformazione delle unità liguri e liguri-piemontesi. la successiva fase collisionale, che ha interessato questo settore dell’appennino settentrionale tra l’eocene superiore-oligocene ed il miocene inferiore, ha determinato la deformazione e l’impilamento delle unità tettoniche (interne) liguri e liguri-piemontesi sulle unità (esterne) toscane. la fase collisionale è stata seguita, probabilmente a partire dal miocene inferiore-medio, da una tettonica estensionale che ha causato l’apertura del bacino tirrenico e la risalita prima del plutone granodioritico del m. capanne (5,8-6,8 ma: metodo rb/sr, jateau et al., 1984; 6,7-6,9 ma: metodo rb/sr, ferrara & tonarini, 1985; 1993) ed in seguito del più piccolo plutone monzogranitico di la serra-porto azzurro (4,9-5,4 ma: metodo rb/sr, saupè et al., 1982; 5,9 ma: metodo ar40/ar39, maineri et al., 2003). la messa in posto dei corpi intrusivi ha determinato il termometamorfismo delle rocce incassanti, il sollevamento dell’area e lo scivolamento gravitativo dell’intero impilamento di falde (trevisan, 1950). questo meccanismo di scivolamento gravitativo ha portato alla traslazione verso est ed alla sovrapposizione anomala delle unità tettoniche formatesi nella fase collisionale: si è così delineata una struttura a scaglie tettoniche embricate e ripetute, separate da superfici di scorrimento sub-orizzontali. le ultime fasi di risalita del plutone di la serra-porto azzurro possono, inoltre, aver ulteriormente deformato le precedenti strutture del m. calamita e prodotto la blanda mega-antiforme del promontorio omonimo (garfagnoli et al., 2005). l’intero edificio strutturale elbano è stato, infine, disarticolato da una fase tettonica distensiva, di probabile età miocene superiore-pliocene inferiore, che ha dato luogo a faglie normali ad alto angolo ad andamento prevalente n-s (barberi et al., 1969; bortolotti et al., 2001) e ne-so e no-se (garfagnoli et al., 2005). promontorio del m. calamita (fig. 1a). le varie unità tettoniche che caratterizzano la parte centroorientale dell’isola d’elba furono per la prima volta suddivise da trevisan (1950) in cinque “complessi”. questo schema tettonico, ripreso e lievemente modificato da barberi et al. (1967a; 1969), è stato successivamente reinterpretato, ridenominato ed integrato da bortolotti et al. (2001). questi ultimi autori, in occasione del nuovo rilevamento geologico 1:10.000 dell’elba centroorientale, hanno infatti individuato nove principali unità tettoniche, di cui tre affioranti nell’area del m. calamita, 1 il rilevamento è stato effettuato nell’ambito della convenzione tra il servizio geologico nazionale, ora apat servizio geologico d’italia/dipartimento difesa del suolo, e l’università degli studi di roma tre, dipartimento di scienze geologiche. che verranno sinteticamente descritte di seguito a partire da quella più profonda. 1) “unità di porto azzurro” (corrispondente al “complesso i” di trevisan, 1950). e’ costituita da rocce polimetamorfiche, di almeno 800 m di spessore apparente, che formano la maggior parte del promontorio del m. calamita. esse vengono comunemente considerate il basamento metamorfico dell’isola d’elba. l’unità comprende una successione paleozoica di probabile età pre-carbonifera, denominata da garfagnoli et al. (2005) “complesso metamorfico di monte calamita”. le rocce di questa successione più abbondanti in affioramento sono scisti quarzoso-muscoviti23le eolianiti dell’isola d’elba ... co–biotitici. essi contengono porfiroblasti di andalusite, plagioclasio e più raramente granato. il complesso metamorfico di monte calamita è sormontato, in discordanza stratigrafica, da una copertura costituita da meta-sedimenti silicoclastici triassici (quarziti di barabarca) e da successioni carbonatiche del ?triassico superiore-?hettangiano (formazioni di tocchi e di calanchiole). le quarziti di barabarca hanno uno spessore massimo apparente di circa 50 m. esse contengono livelli fillosilicatici, filladi “macchiettate” (bonatti & marinelli, 1951) e “microanageniti” (barberi et al., 1967b). nell’insieme, questi tipi litologici sono comunemente riferiti al verrucano. la formazione di fig. 1 – rilievo ombreggiato dell’isola d’elba, ricavato dal modello digitale del terreno dell’igm con risoluzione di 20 m. sono indicati i toponimi riportati nel testo (nei riquadri le località di studio). a) settore del promontorio del m. calamita. b) settore del golfo di viticcio. shaded relief of the elba island, obtained from the 20 meter-resolution digital elevation model of igm. toponyms reported in the text are indicated (study areas are framed). a) mt. calamita sector. b) viticco gulf sector. 24 tocchi ha uno spessore massimo apparente di circa 150 m. le rocce che la costituiscono sono state interpretate come metadoloareniti con letti di calcescisti, talora fortemente tettonizzate (garfagnoli et al., 2005). i litotipi ascritti alla formazione di calanchiole non affiorano nelle aree oggetto del presente studio. nell’area di porto azzurro e nel settore orientale del promontorio del m. calamita, il complesso metamorfico è attraversato da numerosi filoni aplitici e subordinatamente granitico-granodioritici, connessi al plutone di la serra-porto azzurro (marinelli, 1959). 2) “unità ofiolitica” (“complesso iv” di trevisan, 1950). affiora solo nella più occidentale delle due isole gemini ed è rappresentata da serpentiniti e gabbri del giurassico superiore–cretacico inferiore. questa unità non è quindi compresa nelle aree esaminate nel presente lavoro. 3) “unità del flysch cretacico” (parte superiore del “complesso v” di trevisan, 1950). si estende tra la spiaggia delle calanchiole ed il centro abitato di capoliveri; inoltre, un piccolo affioramento è costituito dallo scoglio corbella. essa è separata dalla sottostante unità di porto azzurro da un orizzonte cataclastico decametrico, connesso alla faglia estensionale a basso angolo dello zuccale (keller & pialli, 1990; pertusati et al., 1993; daniel & jolivet, 1995). l’unità è rappresentata da una sequenza di terreni del cretacico superiore in facies di flysch. in particolare, si tratta di argille passanti verso l’alto ad arenarie e conglomerati torbiditici (arenarie di ghiaieto) e successivamente alternanze di marne, calcari marnosi e arenarie (formazione di marina di campo). questi litotipi sono interessati da frequenti, e localmente spesse, intrusioni filoniane e di ammassi granodioritici. numerosi studi mineralogici e petrografici si sono succeduti negli anni riguardo queste rocce: i loro risultati sono riportati in forma sinottica nella tab. 1a. golfo di viticcio (fig. 1b). il piccolo centro abitato di viticcio si affaccia sull’omonimo golfo, il quale è compreso tra il promontorio del m. enfola a nord ed il promontorio di penisola a sud. il substrato dell’area del golfo di viticcio comprende due sole tipologie litologiche, le cui caratteristiche sono riassunte nella tab. 1b. barberi et al. (1967a; 1969) evidenziano, nel settore in esame, la presenza di rocce del cretacico superiore in facies di flysch: esse molto probabilmente corrispondono alla formazione di marina di campo, che costituisce l’estrema parte superiore del “complesso v” di trevisan (1950), ovvero la parte superiore dell’“unità del flysch cretacico” di bortolotti et al. (2001). questa successione flyschoide, è descritta in letteratura in modo diverso da vari autori. aiello et al. (1977) hanno distinto tre facies in cui il contenuto percentuale in pelite aumenta verso l’alto. all’interno della stessa formazione, invece, bortolotti et al. (2001) hanno distinto quattro litotipi: 1) arenarie quarzoso-feldspatiche senza cemento carbonatico; 2) arenarie quarzoso-feldspatiche con cemento carbonatico; 3) calcareniti e marne; 4) argilliti. nel settore di viticcio, la formazione di marina di campo risulta frequentemente interessata da estese intrusioni di porfidi a composizione prevalentemente granitico-granodioritica, in forma di espandimenti, ammassi irregolari e filoni. dal punto di vista petrografico, i porfidi sono suddivisibili in due unità (marinelli, 1955; dini et al., 2002): 1) i “porfidi di portoferraio”, i quali affiorano in tutta l’elba centro–settentrionale, dove formano diversi strati laccolitici spessi fino a 700 m e numerosi dicchi. essi hanno composizione prevalentemente granodioritica, localmente sienogranitica; 2) i “porfidi di san martino”, i quali sono localizzati nei settori settentrionale e meridionale del golfo di viticcio, dove formano tre strati laccolitici spessi fino a 400 m e alcuni dicchi. essi hanno composizione granodioritica. 3. inquadramento geomorfologico l’elba si erge da una piattaforma continentale, che si estende dal litorale toscano sino al canale di corsica (fig. 1). la relativa regolarità del fondale marino, appartenente all’area di piattaforma circostante l’elba, è interrotta a nord e a sud dalle depressioni che si immettono rispettivamente nel bacino marino ubicato tra capraia ed il continente ed in quello situato tra montecristo ed il giglio, e ad ovest dalla dorsale sottomarina elba-pianosa (wezel, 1982), allungata in direzione n-s parallelamente al bacino corso. l’assetto e l’evoluzione geomorfologica dell’isola d’elba sono poco noti, anche a causa della mancanza in affioramento di sedimenti marini neogenici e quaternari e della scarsità di depositi continentali quaternari; questi ultimi, infatti, si rinvengono in areali piuttosto ristretti e sono principalmente costituiti da depositi alluvionali, di spiaggia, eolici, di versante e da coltri eluviocolluviali. ad uno sguardo d’insieme, il territorio elbano si presenta fortemente accidentato per la contiguità di rilievi di varia altezza e conformazione morfologica. l’elevata acclività dei versanti elbani è a volte interrotta da piccole superfici sub-orizzontali, distribuite a varie quote, le quali hanno suscitato l’interesse di studiosi come desio (1922) e centamore et al. (1988). in particolare, gli autori di quest’ultimo lavoro riconoscono, in quasi tutta l’isola, almeno tre ordini di superfici di spianamento relitte (rispettivamente 90-120 m, 45-75 m e 15-20 m s.l.m.) ed ipotizzano, anche se in assenza di precisi riferimenti crono-biostratigrafici, il loro collegamento con i livelli marini pleistocenici. i rilievi sono spesso delimitati verso mare da ripide falesie, e nell’entroterra sono solcati da incisioni vallive che terminano in anguste insenature o piccole baie marine. solo una modesta porzione del territorio elbano è contraddistinta da esigue piane alluvionali e costiere. rühl (1912) e poi barberi et al. (1969) hanno interpretato le insenature marine, presenti lungo le coste frastagliate in corrispondenza delle valli fluviali, come forme di sommersione, dovute all’ultima risalita eustatica del livello marino. oltre alla risalita eustatica, barberi et al. (1969), in conseguenza della totale assenza in affioramento di depositi marini neogenici e quaternari, ipotizzano una generale subsidenza dell’isola, che avrebbe coinvolto questi depositi in un lento abbassamento a partire dal pliocene. depositi di entrambe le età affiorano, invece, nella vicina isola di pianosa (foresi et al., 2000; graciotti et al., 2002-2003) e sono stati attraversati da due pozzi, mimosa 1 e martina 1, eseguiti dall’agip negli anni ’70, sulla dorsale sommersa m. d’orefice, r. graciotti & f. capitanio 25 tab. 1 – sinottica delle litologie e delle paragenesi del substrato delle aree in esame. lithology and parageneses of the substrate of the studied areas. formazione o unità intrusioni terziarie litotipi da graniti a granodioriti in filoni, ammassi ed espandimenti apliti in filoni strutture e tessiture porfirica; (micro)porfirica; pdf da granulare a granofirica pdf trachitica costituenti fondamentali fenoxx: kf, qtz, bt, pl; fenoxx: qtz, kf, pl, ms; pdf: qtz, pl, kf, bt pdf: (?) costituenti subordinati tur tur costituenti occasionali ap, zrn, ttn, aln, mnz, thorite mnz, xenotimo, nb-ta-ossidi fasi “autometamorfiche”: sericite, chl, cal, py, argille referenze porfidi (1; 2; 9) “euriti” (1) apliti (9) a) monte calamita formazione o unità “scisti del calamita” intrusioni terziarie litotipi micascisti e filladi da graniti a granodioriti apliti in filoni in piccoli ammassi e filoni strutture e tessiture strati quarzosi granoe porfiroblastici; porfirica; strati micacei lepidoe porfiroblastici pdf da granofirica a scistosa (micro)porfirica costituenti qtz, ms, bt, chl fenoxx: qtz; fenoxx: qtz; fondamentali pdf: pl, kf, qtz, bt pdf: pl, kf, qtz, bt costituenti subordinati and, pl, sericite, crd, kf ap, zrn, tur, crd tur, and, crd, ms costituenti occasionali tur, ap, zrn, ttn, rt, mag, hem, py and, py grt, ap, zrn scisti quarzoso-micacei (1) porfiriti (2) apliti (3) referenze scisti quarzoso-muscovitico-biotitici (3) porfidi (6) scisti (quarzoso-)muscovitico-biotitici (5) micascisti e filladi (quarzitici) (10) formazione o unità prodotti termometamorfici litotipi anfiboliti in lenti negli scisti cornubianiti in piccoli ammassi skarn in piccoli ammassi (c. pianuccio remaiolo) (capoliveri m. calamita) (c. calamita – sassi neri) strutture e tessiture da granolepidoa nematoblastica granolepidoblastica (?) granolepidoblastica costituenti fondamentali ortoam, pl pl, cpx. grt hbl, pl, kf costituenti subordinati qtz, ms, bt, hbl, ap, zrn, ttn, tur ttn, ap, cal ortoam, grt, cpx, ep, mag, py costituenti occasionali ap, ttn, ilm referenze anfiboliti (5; 10) cornubianiti (5) skarn (1; 10) formazione o unità quarziti di barabarca litotipi quarziti metaconglomerati strutture e tessiture da granoa lepidoblastica (?) costituenti fondamentali qtz clasti: qtz; fillosilicati cemento: qtz, miche costituenti subordinati and costituenti occasionali ap, tur, hem referenze quarziti di barabarca (5; 10) “microanageniti” (5) formazione o unità fm marina di campo litotipi areniti calcari scisti strutture e tessiture (?) (?) (?) costituenti fondamentali clasti: qtz, kf, pl, bt, ms cal argille cemento: fillosilicati, carbonati costituenti subordinati costituenti occasionali femici (?) referenze flysch (4) fm marina di campo (7; 8) formazione o unità fm tocchi fm calanchiole litotipi calcari dolomitici; filladi marmi e dolomie cristalline calcescisti strutture e tessiture da nematoa lepidoblastica diablastica da granoa xenoblastica costituenti fondamentali cal, dol qtz, fillosilicati cal, dol costituenti subordinati qtz, pl, bt, ortoam qtz, sericite costituenti occasionali anh, ccp, tur, mag, hem, py ortoam, phl, ap, hem referenze carbonati di capoliveri (3) marmi del calamita (5) fm tocchi (5; 10) fm calanchiole (10) b) golfo di viticcio referenze: 1 = bonatti e marinelli,1951; 2 = marinelli, 1955; 3 = marinelli, 1959; 4 = parea, 1964; 5 = barberi et alii, 1967b; 6 = barberi et alii, 1969; 7 = aiello et alii, 1977; 8 = bortolotti et alii, 2001a; 9 = dini et alii, 2002; 10 = garfagnoli et alii, 2005. le eolianiti dell’isola d’elba ... 26 elba-pianosa (cornamusini et al., 2002). inoltre, i vari profili sismici eseguiti in corrispondenza della piattaforma toscana evidenziano, nella loro parte superiore, la presenza di riflettori ben definiti in onlap sul substrato neogenico, riferibili a depositi quaternari marini (pascucci, 2002). alcune campagne oceanografiche, condotte dall’istituto di geologia marina del cnr di bologna (roveri & correggiari, 2004), hanno evidenziato le principali caratteristiche sedimentologiche dei depositi plio(?)-pleistocenici che costituiscono il tratto di piattaforma compreso tra l’elba e pianosa e quello circostante l’isola di capraia. i risultati di tali ricerche, basate su profili sismici e campionature, consentono di attribuire i sedimenti sopra citati a corpi deposizionali progradanti, costituiti da biocalcareniti e biocalciruditi ad alghe calcaree. promontorio del m. calamita. quest’area è caratterizzata da una peculiare forma tozza che si erge bruscamente dal mare, raggiungendo la quota massima di 412 m s.l.m. (fig. 1a). tale conformazione orografica è strettamente connessa al particolare assetto strutturale dell’area, contraddistinto dalla presenza della sopra citata mega-antiforme del m. calamita. più dell’80% di costa è alta, con ripide falesie, in gran parte attive, che raggiungono a volte altezze anche superiori ai cento metri, come nel tratto della costa dei gabbiani (estremo settore meridionale del promontorio). la linea di costa è molto frastagliata ed articolata a causa delle numerose piccole baie delimitate da dorsali rocciose che si protendono verso il mare. la parte sommitale del m. calamita mostra un allungamento in direzione e-o, corrispondente alla dorsale m. calamita–poggio fino. da essa si dipartono, con andamento radiale, numerose vallecole a “v”, che con un’elevata pendenza, dopo un percorso di circa 2 km, raggiungono direttamente il mare. le aste fluviali, in genere abbastanza rettilinee e di ordine gerarchico basso (non superiore al 4°) secondo la classificazione di strahler (1957), sottendono bacini imbriferi spesso stretti ed allungati. tali bacini hanno una pendenza media variabile tra i 10° e i 22° e un’estensione media di circa 0,8 km2; i bacini di maggior estensione sono esposti prevalentemente verso i quadranti occidentali. gli attuali thalweg fluviali sono incisi sia nel substrato metamorfico e sedimentario, sia nei depositi alluvionali recenti. piccoli conoidi alluvionali di origine mista, generati da dinamiche fluviali e di massa, sono ubicati allo sbocco dei corsi d’acqua nelle cale prospicienti la costa. golfo di viticcio. i rilievi a monte dell’abitato di viticcio presentano una minore elevazione rispetto a quelli del promontorio del m. calamita: infatti, i primi raggiungono la quota massima di 230 m s.l.m. (località le cime), in corrispondenza dello spartiacque tra i bacini idrografici drenanti verso il golfo di viticcio e il bacino del fosso acquaviva drenante verso nord (fig. 1b). in prossimità della linea di riva, questi rilievi danno luogo a coste alte, caratterizzate da falesie con altezza di circa 20 m, che si interrompono in coincidenza di alcune calette. esse ospitano piccole spiagge contraddistinte prevalentemente da depositi grossolani, costituiti da ghiaie e blocchi, con diametro massimo di circa 1 m; i singoli elementi presentano un elevato indice di arrotondamento e sono costituiti essenzialmente da litotipi flyschoidi e porfiroidi. le spiagge, tra cui quella del viticcio, sono ubicate allo sbocco di impluvi a regime temporaneo, che drenano modesti bacini idrografici. generalmente i bacini, orientati verso no, hanno una forma stretta ed allungata ed un basso ordine gerarchico (1° o 2°) in base alla classificazione di strahler (1957); solo quello più meridionale, di maggior estensione, è contraddistinto da una forma più o meno rettangolare e da un reticolo idrografico di 4° ordine gerarchico. 4. aspetti geomorfologici e strutture sedimentarie delle eolianiti 4.1. aspetti geomorfologici promontorio del m. calamita. nell’area del m. calamita, le eolianiti affiorano con continuità nella fascia costiera compresa tra la punta di barabarca e la spiaggia della madonna (fig. 1a), dove ammantano le antiche coste rocciose modellate nel substrato e solitamente danno origine a corpi sedimentari disposti all’incirca parallelamente alla linea di costa. questi depositi si rinvengono, inoltre, all’interno delle incisioni vallive, che sfociano in corrispondenza delle insenature marine di barabarca, di stecchi, di mad.na delle grazie, di peducelli, di morcone, di pareti e dell’innamorata. in tal caso, essi danno luogo a corpi di spessore più che decametrico, alloggiati all’interno dei fondovalle fluviali, che risalgono, a partire dalla costa, per distanze di diverse centinaia di metri (fig. 2a), superando anche i 100 m di quota s.l.m., come nel caso degli affioramenti della mad.na delle grazie. la loro incisione da parte del reticolo idrografico attuale, dà luogo a forre, al cui interno frequentemente si rinvengono accumuli da frana di crollo e/o ribaltamento. generalmente, la superficie erosiva, attraverso la quale i depositi in esame poggiano in discordanza sul substrato metamorfico e sedimentario, è identificabile all’interno delle incisioni vallive e in alcuni casi lungo il litorale, a causa dell’arretramento costiero indotto dall’erosione marina. tuttavia a questo fa eccezione l’affioramento della spiaggia della madonna, dove nella zona supratidale la superficie d’erosione non è visibile in quanto collocata al di sotto dell’attuale livello marino (fig. 2b). golfo di viticcio. le eolianiti affiorano in corrispondenza della parte medio-alta della falesia che, con un’altezza di circa 20 m, domina la spiaggia del viticcio (fig. 1b). esse costituiscono un corpo sedimentario di forma prismatica di circa 15 m di spessore massimo, il quale va progressivamente rastremandosi verso l’entroterra, risalendo il versante retrostante sino a circa 70 m di quota s.l.m. (fig. 3). il corpo sedimentario è limitato alla base da una superficie d’erosione, degradante verso mare con una pendenza di circa 20°, attraverso la quale poggia in discordanza sul substrato, rappresentato da porfidi granodioritici e granitici e dal flysch appartenente alla formazione di marina di campo. al tetto il litosoma è delimitato da una superficie m. d’orefice, r. graciotti & f. capitanio d’erosione corrispondente all’attuale superficie topografica. 4.2. caratteri macroscopici delle eolianiti le rocce del presente studio hanno un colore 2,5 y 5/4 (marrone giallastro). dal punto di vista granulometrico, esse sono costituite prevalentemente da sabbie a grana media e grossolana ed in misura molto minore da ghiaie minute (granuli di diametro tra 2 e 4 mm). in linea generale, la cementazione è elevata al punto tale da formare delle vere e proprie areniti ed in rari casi delle ruditi. il grado di cementazione è, comunque, variabile in funzione della granulometria dei grani. infatti, gli strati a granulometria più fine tendono ad essere maggiormente cementati rispetto a quelli a granulometria più grossolana. i l diverso grado di cementazione viene enfatizzato dalla morfoselezione, che mette in evidenza un’alternanza di strati più e meno resistenti ai processi erosivi (fig. 2b). all’interno dei singoli strati non si riscontra una gradazione dei granuli; sono, invece, visibili inclusi litici di dimensioni millimetriche. macrofaune fossili sono quasi del tutto assenti ad eccezione di qualche frammento di bivalve marino (avente dimensioni non superiori a qualche centimetro) e rari gusci di gasteropodi terrestri. 4.3. principali strutture sedimentarie delle eolianiti nel loro insieme, le eolianiti sono caratterizzate internamente da strutture sedimentarie principali, che consistono essenzialmente in stratificazione incrociata a grande scala. uno dei migliori esempi di queste strutture sedimentarie è visibile nella sezione di origine antropica ubicata circa 200 m a nord della spiaggia della madonna, dove è osservabile in tre dimensioni la stratificazione sopra descritta (fig. 2c). infatti, la gran parte della sezione, ad eccezione dell’estrema porzione superiore, è contraddistinta da stratificazione incrociata di tipo piana-tabulare. prevalgono i set di strati frontali, i quali general27 fig. 2 – area di madonna delle grazie. a) affioramento di eolianiti nei pressi della chiesa della madonna delle grazie (a quota circa 30 m s.l.m.). set di strati immergenti contro monte con una pendenza di circa 20°; b) affioramento di eolianiti nei pressi della spiaggia della madonna; c) ricostruzione schematica delle strutture sedimentarie e delle superfici d’erosione dell’affioramento di eolianiti in b). la maggior parte della sezione è composta da un set di strati, ad alto angolo, di forma tangenziale immergenti verso terra (b). il set è delimitato da due superfici di erosione (s1 e s2), debolmente inclinate verso mare, ed è caratterizzato al suo interno da numerose superfici di riattivazione. sulla superficie superiore (s2) poggiano in discordanza detriti di versante clinostratificati (d), a cui segue in concordanza una sequenza eolica con stratificazione pianoparallela a basso angolo d’inclinazione (c). è interessante notare la prosecuzione del corpo sedimentario sia in direzione orizzontale (verso mare), sia in quella verticale (al di sotto dell’attuale battigia). the madonna delle grazie area. a) aeolianite outcrop near the church of madonna delle grazie (about 30 m a.s.l.). foresets dipping about 20° landward; b) aeolianite outcrop near the spiaggia della madonna; c) schematic reconstruction of sedimentary structures and erosion surfaces of the aeolianite outcrop of b). the cut is mostly built up by a high angle foresets dipping landward and tangent to the base (b). the set is bounded by two erosional surfaces (s1 and s2), slightly dipping seaward, and it contains several reactivation surfaces. stratified slope-waste deposits (d) lie unconformably on the upper erosion surface (s2). an aeolian sequence (c), with a low angle parallel stratification, lies conformably on slope-waste deposits. it is interesting to note the extension of the whole sedimentary body in both the horizontal (towards the sea) and the vertical (under the present waterline) directions. a) b) c) le eolianiti dell’isola d’elba ... mente hanno un’immersione verso terra ed assumono una forma tangenziale verso la base. i singoli strati sono spessi da 5 a 25 mm ed hanno, nella loro porzione più elevata, inclinazioni prevalentemente ad alto angolo variabili tra i 25° ed i 32°, ma che in alcuni casi possono raggiungere i 35°. i set di strati frontali sono di tipo composto in quanto contengono al loro interno delle superfici di discontinuità. i singoli set di strati sono troncati da superfici di erosione, inclinate di circa 10° 12° verso mare e contraddistinte da una evidente ondulazione. in particolare, nell’affioramento della spiaggia della madonna sono visibili due superfici di erosione che troncano verso l’alto due set di strati frontali, caratterizzati da giaciture differenti. infatti, il set più alto (b), delimitato al tetto dalla superficie superiore (s2), è spesso da circa 4,5 a 5,5 m ed è costituito da strati frontali con una direzione d’immersione variabile tra n60° e n80° ed inclinazione degli stessi fino a 35°. il set sottostante (a), delimitato al tetto dalla superficie inferiore (s1), è formato, invece, da strati con direzione d’immersione n40° e pendenza di circa 10°. al di sopra della superficie di erosione superiore (s2), poggiano in discordanza, depositi di versante (d) di circa 70-80 cm di spessore, costituiti da strati a geometria piano-parallela con basso angolo d’inclinazione, variabile tra 10° e 12°, e con un’immersione in genere verso mare (n220°). ai depositi di versante, segue, in concordanza, un’altra sequenza eolica (c) di circa 50 cm di spessore, caratterizzata da una stratificazione da piano-parallela a leggermente ondulata. quest’ultima è delimitata superiormente da una superficie d’erosione corrispondente all’attuale piano topografico. nell’area di viticcio, le eolianiti sono organizzate in strati prevalentemente piano-paralleli, debolmente inclinati verso mare. in diversi affioramenti, all’interno delle areniti si rinvengono strutture sedimentarie secondarie costituite da concrezioni intrasedimentarie sia sub-orizzontali e sia verticali (fig. 4). le prime, più frequenti, si presentano come corpi arenacei fortemente allungati, dalla forma più o meno cilindrica e con sezione trasversale circolare, ellittica o irregolare (diametro variabile tra 0,5 e 2 cm). questi elementi cilindrici, spesso tra loro coalescenti, sono inclinati verso mare di circa 10°. le seconde, più rare, sono costituite da corpi arenacei analoghi ai precedenti, dai quali si distinguono nettamente per essere allungati verticalmente, per una minore uniformità di cementazione e per le minori dimensioni. 4.4. paleosuoli e depositi di versante associati alle eolianiti alternati ai depositi arenacei si rinvengono, di solito, degli orizzonti prevalentemente sabbiosi di colore rosso, talora associati a detriti di versante costituiti da clasti poligenici con tessitura a supporto di matrice. in particolare, nel tratto di costa tra la punta di barabarca e la spiaggia di stecchi sono state individuate due sequenze eoliche, con intercalato un paleosuolo rubefatto (fig. 5a-b). 28 fig. 3 spiaggia del viticcio. depositi eolici poggianti sul substrato igneo e flyschoide attraverso una superficie d’erosione (linea bianca tratteggiata) inclinata di circa 20° verso mare. il corpo sedimentario, contraddistinto da una forma prismatica, va progressivamente rastremandosi verso terra. allo stato attuale, i depositi sono sottoposti ad uno scalzamento alla base da parte del mare, con conseguente innesco di fenomeni di crollo e ribaltamento. the spiaggia del viticcio. aeolian deposits lie on the igneous and flyschoid substrate by an erosion surface (dashed white line), which is almost 20° dipping seawards. the prismatic sedimentary body becomes progressively thinner landward. at present, these deposits are undergoing underwash by the seawaters: this is a triggering factor for rockfall and topple phenomena. fig. 4 tratto di costa tra punta di barabarca e stecchi. depositi eolici caratterizzati prevalentemente da tubuli suborizzontali e subordinatamente verticali. coastline between punta di barabarca and stecchi. aeolian deposits are characterized by tubules: they have mainly subhorizontal and in a lesser extent vertical elongation. m. d’orefice, r. graciotti & f. capitanio esso ha un colore 2,5 yr 4/6 (rosso), una geometria lenticolare ed è costituito da sabbie limose a volte debolmente argillose, con spessori che possono superare abbondantemente il metro. sia nella frazione fine sia in quella grossolana non si riscontra presenza di carbonato di calcio. le superfici esposte agli agenti atmosferici presentano grado di compattezza abbastanza elevato. la materia organica, in genere scarsa, è costituita da piccoli frammenti di carbone, che hanno fornito, nel caso della sezione di m.na delle grazie, un’età 14c di 48.000 ± 1.900 anni b.p. (cremaschi & trombino, 1998). questa datazione, seppure al limite del metodo, è in sostanziale accordo con un’altra effettuata dagli autori sopra citati su un analogo paleosuolo rinvenuto tra due sequenze eoliche affioranti presso cala cancherelli (elba settentrionale). i frammenti di carbone contenuti in questo paleosuolo, situato in un contesto stratigrafico e morfologico identico a quello di m.na delle grazie, hanno infatti fornito un’età radiometrica di 40.831 ± 1.373 anni b.p. nel medesimo paleosuolo sono stati inoltre rinvenuti, dagli stessi autori, manufatti musteriani. all’interno delle eolianiti e del paleosuolo si possono notare, a varie altezze, sottili lenti oppure livelli sub-orizzontali o debolmente inclinati di materiale detritico (d), costituito da elementi poligenici, eterometrici (dimensioni da millimetriche a decimetriche) e spigolosi, spesso fortemente cementati, legati a fasi erosive dei versanti soprastanti (fig. 5b). i corpi detritici in posizione stratigrafica inferiore sono quelli poggianti direttamente sul substrato e sottostanti ai depositi eolici, mentre quelli in posizione stratigrafica più elevata si sovrappongono direttamente alla sequenza eolica superiore. nell’affioramento della spiaggia della madonna, le lenti detritiche comprese nelle porzioni a stratificazione incrociata (b: vedi fig. 2c) delle eolianiti possono raggiungere uno spessore massimo di 40 cm ed una lunghezza di 5 m (fig. 6a); i clasti sono costituiti da frammenti di rocce metamorfiche nerastri e verdastri (prevalentemente micascisti, quarziti e calcari termometamorfosati), spesso ad elevato grado di alterazione. al di sopra dei depositi eolici (b), si rinvengono i sopraccitati livelli detritici a stratificazione piano-parallela (fig. 6b). in questo caso, però, i clasti non sono in contatto reciproco, ma sono a supporto della matrice sabbioso-ghiaiosa che costituisce le eolianiti. in questi livelli, le dimensioni dei clasti tendono ad aumentare procedendo verso l’alto, passando da alcuni millimetri di diametro a circa 10 cm. gli elementi di forma piatta di solito sono allungati secondo il loro asse maggiore ed alcuni presentano una leggera embricatura. 4.5. micro e macroforme di erosione superficiale e fenomenologie di dissesto lungo la fascia costiera, i depositi arenacei in esame, ed in particolare quelli tra stecchi e la spiaggia della madonna, sono interessati, sulla loro superficie superiore, da peculiari forme di erosione di varia tipologia. in analogia con quanto osservato da mazzanti & parea (1977) lungo il litorale livornese, tali forme sono disposte lungo distinte fasce fisiografiche parallele alla linea di riva e di ampiezza variabile in funzione dell’acclività della costa. esse sono distribuite fra il limite massimo raggiunto dai marosi di tempesta e la parte terminale degli affioramenti di eolianiti al di sotto del l ivello del mare. procedendo verso mare, a partire dal limite inferiore della zona completamente vegetata e considerando solo le forme di erosione subaeree, è possibile 29 fig. 5 paleosuoli e depositi di versante (d) alternati alle eolianiti. a) tratto di costa tra punta di barabarca e stecchi. paleosuolo rosso intercalato tra due corpi sedimentari di eolianiti. all’interno del paleosuolo si notano dei livelli sub-orizzontali formati da clasti, anche decimetrici, eterometrici e spigolosi, costituiti da detriti di versante (d); b) ricostruzione schematica della successione stratigrafica affiorante poco a nord di stecchi. si possono osservare due sequenze di natura eolica, con intercalato un paleosuolo rosso. la sequenza inferiore poggia su depositi di versante. paleosoils and slope debris (d) interbedded with the aeolianites. a) coast between punta di barabarca and stecchi. rubified paleosol interbedded between two aeolianite sedimentary bodies. inside the paleosol, some sub-horizontal levels are evident: they are slope debris (d) built up by angular and heterometric, up to dm-sized, clasts; b) schematic reconstruction of the stratigraphic succession outcropping just north of stecchi. two aeolian sequences with an interbedded red paleosol are recognizable. the lower sequence lies on slope deposits. a) b) le eolianiti dell’isola d’elba ... distinguere una zona supratidale e una zona intertidale. questa distinzione può essere agevolmente operata nei tratti di costa bassa, come appunto tra stecchi e la spiaggia della madonna. in sintesi, nella zona supratidale si riconosce una fascia superiore di colore chiaro, interessata da una elevata “spugnosità” conferita da “tubuli” verticali internamente vuoti, che si ergono dal suolo per circa 20 cm, a cui sono associate piccole vaschette di forma irregolare e con un diametro massimo dell’ordine del decimetro. queste sono svasate verso l’alto e spesso hanno il fondo colmato da suolo su cui attecchiscono essenze vegetali. questa fascia sfuma verso mare in una seconda più scura, caratterizzata da vaschette di corrosione a contorno irregolare per la coalescenza di più forme erosive. le vaschette, prive di un’orientazione preferenziale, hanno l’asse maggiore di lunghezza variabile da qualche decimetro ad alcuni metri. esse tendono, comunque, a regolarizzarsi con l’approssimarsi della fascia intertidale. i setti divisori tra le varie vaschette, spesso sottili e taglienti, sono cesellati da un insieme di vacuoli disposti “a nido d’ape” e con apertura generalmente orientata verso mare. nella zona intertidale, di estensione metrica e colore più scuro rispetto alla precedente poiché satura di acqua marina, le cavità assumono progressivamente una forma cilindrica e possono essere considerate delle vere e proprie marmitte di abrasione marina (fig. 7). esse sono in genere singole, hanno un diametro massimo di circa 1 m ed una profondità che può raggiungere i 40-50 cm. le pareti tendono ad essere aggettanti verso l’alto, mentre il fondo è piatto e privo di deposito. in corrispondenza della fascia costiera, tra stecchi e la spiaggia della madonna, è possibile osservare che le eolianiti sono interessate da due principali famiglie di fratture verticali, con direzione rispettivamente n50° e n140° e spaziatura di 30 fig. 6 diverse posizioni stratigrafiche dei detriti di versante (d). a) eolianite affiorante presso la spiaggia della madonna. lente detritica all’interno del set a stratificazione incrociata (porzione basale di b: vedi fig. 2c); b) stesso affioramento di a). detriti di versante stratificati, inclinati di 10-12° verso mare, poggianti in discordanza sul set a stratificazione incrociata (porzione sommitale di b) attraverso la superficie di erosione s2. different stratigraphic positions of slope debris (d). a) aeolianite outcropping near the spiaggia della madonna. a lens of debris inside the cross-stratified set (basal portion of b: see fig. 2c) is recognizable; b) same outcrop as a). stratified slope-waste deposits, 10-12° dipping seaward, lying unconformably on the cross-stratified set (upper portion of b) by the erosion surface s2. a) b) m. d’orefice, r. graciotti & f. capitanio alcuni metri. l’intersezione di queste due famiglie di fratture con le superfici di discontinuità sub-orizzontali legate alla stratificazione o alla presenza delle superfici di erosione, porta all’isolamento di prismi di una decina di m3 di volume, che a causa dell’erosione marina possono trovarsi, in prossimità della costa, in condizioni d’instabilità o addirittura essere coinvolti in crolli o ribaltamenti (fig. 8). 5. mineralogia e petrografia delle eolianiti 5.1. caratteri microscopici delle eolianiti i granuli che costituiscono i depositi eolici del presente studio possiedono una certa variabilità di dimensioni e forme, sia da un affioramento all’altro sia all’interno di uno stesso affioramento. ciò rende difficoltoso il confronto tra i diversi depositi, eseguito sulla base dei soli caratteri morfometrici dei granuli. tuttavia, nel presente lavoro è stata svolta un’indagine a scala microscopica finalizzata non solo ad identificare le specie mineralogiche e gli inclusi litici presenti in questi depositi, ma anche a verificare la possibilità di ottenere trend significativi a partire dalle misure morfometriche dei granuli, dalle quali possono scaturire delle informazioni utili alla correlazione tra i diversi affioramenti. a questo scopo, è stato eseguito un campionamento mirato sulla porzione granulometricamente più fine delle rocce in affioramento, in quanto: i) la frazione più fine è volumetricamente sempre predominante, anche nel caso di rocce costituite da alternanze con livelli a granulometria sabbioso-ghiaiosa; ii) solo il confronto tra campioni aventi granulometrie analoghe può fornire dati direttamente correlabili. la caratterizzazione mineralogico-petrografica delle eolianiti è stata eseguita su sezioni sottili di campioni prelevati negli aff ioramenti di barabarca, stecchi, mad.na delle grazie e viticcio. per ogni campione, sono state effettuate diverse sezioni sottili orientate parallelamente e perpendicolarmente rispetto alla stratificazione. in generale, i campioni analizzati presentano una composizione mineralogica abbastanza uniforme. essi sono formati da granuli di natura poligenica e presentano, tra i costituenti principali, bioclasti carbonatici, clasti prevalentemente silicatici e inclusi litici. anche alla scala microscopica, non è evidente alcuna gradazione degli elementi costitutivi della roccia, i quali hanno distribuzione spaziale non organizzata. il grado di selezionamento (sorting) risulta generalmente piuttosto variabile anche in campioni appartenenti allo 31 fig. 7 – marmitte d’abrasione marina modellate nelle eolianiti, affioranti nella zona intertidale superiore della spiaggia di stecchi. marine rock pools modeled into the aeolianites of the upper intertidal zone of the spiaggia di stecchi. fig. 8 fenomeni di crollo e ribaltamento nei depositi eolici tra punta di barabarca e stecchi, innescati dall’intensa azione erosiva da parte del mare. sono visibili i detriti di versante (d) tra substrato quarzitico ed eolianiti. rockfall and topple phenomena are triggered by the intense erosive marine dynamics in the aeolianite deposits outcropping between the punta di barabarca and stecchi. slope debris (d) between the quartzitic substrate and the aeolianites are also recognizable. le eolianiti dell’isola d’elba ... stesso affioramento: ad esempio, a m.na delle grazie i valori determinati per confronto con le carte di comparazione visiva variano tra 0,60 φ (“moderatamente ben selezionato”) e 1,50 φ (“poco selezionato”). la tessitura è generalmente open-work. tuttavia, la maggior parte dei vuoti intergranulari è riempita da cemento carbonatico, che in alcuni casi rende la tessitura cemento-sostenuta. 5.1.1. bioclasti (contributo di g. ventura) la componente organogena (fig. 9a-b) è costituita da frammenti di gusci di dimensioni sub-millimetriche, in genere ben arrotondati, spesso ricristallizzati, appartenenti a lamellibranchi, gasteropodi, echinodermi e briozoi, da frammenti di alghe rosse nodulari e da foraminiferi bentonici (tab. 2). per quanto concerne questi ultimi, sono stati r iconosciuti elementi appartenenti al le famiglie cibicididae (barabarca, stecchi, viticcio), discorbidae (stecchi), elphididae (barabarca, stecchi, mad.na delle grazie, viticcio), miliolidae (barabarca, stecchi, mad.na delle grazie, viticcio), planorbulinidae (mad.na delle grazie), rotalidae (barabarca, mad.na delle grazie) e textularidae (stecchi). si segnala, infine, la presenza di un frammento di foraminifero planctonico (orbulina) in un campione di barabarca. la percentuale dei bioclasti è elevata, seppur variabile anche in uno stesso campione, e può raggiungere anche il 50 % del totale. 5.1.2. clasti prevalentemente silicatici le paragenesi mineralogiche relative alla componente silicoclastica delle areniti esaminate sono riportate nella tab. 3. il dettaglio delle caratteristiche delle sin32 frazione organica campioni barabarca stecchi m.na delle grazie viticcio echinidi (frammenti) x x x molluschi (frammenti) x briozoi (frammenti) x x crostacei (frammenti) x alghe corallinacee x x x x (frammenti) cibicididae lobatula lobatula lobatula lobatula (walker & jacob) discorbis globularis discorbidae (d’orbigny); rosalina bradyi (cushmann) elphididae elphidium elphidium elphidium advenum elphidium advenum (cushmann) (cushmann) adelosina quinqueloculina quinqueloculina seminulum quinqueloculina triloculina triloculina (linnaeus); miliolidae cicloforina massilina adelosina cicloforina triloculina cicloforina planorbulinidae planorbulina mediterranensis (cushmann) rotalidae x x textularidae textularia x orbulinidae orbulina tab. 2 classificazione e distribuzione della frazione organica nelle eolianiti del presente lavoro. classification and distribution of the organic fraction in the aeolianites of this work. f o r a m i n i f e r i tab. 3 sinottica delle paragenesi delle eolianiti del presente lavoro. parageneses of the aeolianites of this work. abbondanza viticcio barabarca stecchi m. delle relativa grazie costituenti qtz qtz qtz qtz fondamentali kf kf kf pl mica bruna kf pl cpx costituenti spl cpx cpx mica bianca subordinati mica bianca spl spl spl hem hem pl mica bruna hem grt mica bianca mica bruna mica bruna costituenti hem mica bianca pl occasionali cpx am grt am ap m. d’orefice, r. graciotti & f. capitanio gole specie mineralogiche riconosciute, invece, è illustrato nella tab. 4. tra i minerali silicatici, il quarzo è la specie mineralogica preponderante; la seconda specie mineralogica per abbondanza è il feldspato potassico; il plagioclasio è molto comune a viticcio e stecchi, risulta meno abbondante a barabarca ed è raro a mad.na delle grazie. l’abbondanza della mica bruna diminuisce da viticcio a barabarca fino a mad.na delle grazie e stecchi; invece, quella della mica bianca varia da apprezzabile (barabarca, mad.na delle grazie) a modesta (stecchi, viticcio). il clinopirosseno è un costituente occasionale a viticcio e subordinato negli altri affioramenti. lo spinello nero è generalmente un costituente subordinato. in tutti i campioni esaminati sono stati rinvenuti rari clasti micritici di natura carbonatica, bene arrotondati, dei quali non è possibile stabilire in modo univoco l’origine extrao intrabacinale. 5.1.3. inclusi litici: descrizione e classificazione nei campioni di areniti esaminati, sono presenti numerose e varie tipologie di inclusi. le loro caratteristiche principali sono illustrate nelle fig. 9b-e e riassunte nella tab. 5: quarzo policristallino, con tessitura isotropa, la cui origine è riconducibile a quarziti; quarzo e subordinate miche, con tessitura scistosa: si tratta di frammenti di quarzoscisti; aggregati costituiti da soli fillosilicati, a grana fine, e aggregati costituiti da fillosilicati, quarzo, plagioclasio e feldspato potassico, a grana media, con evidente tessitura scistosa: i loro protoliti sono micascisti; quarzo e subordinate miche, con tessitura isotropa e grana variabile da grossa a fine: sono frammenti di quarzo-areniti provenienti dal substrato flyschoide; aggregati di feldspato potassico, plagioclasio e clinopirosseno, con tessitura isotropa: si tratta di frammenti di rocce 33 tab. 4 dettaglio delle caratteristiche mineralogiche e petrografiche della componente silicoclastica delle eolianiti del presente lavoro. detail of mineralogical and petrographical features of the siliciclastic component of the aeolianites of this work. specie mineralogica caratteristiche ottiche quarzo subedrale, talora forma geminati semplici, talora ha estinzione ondulata e bordi in dissoluzione. include apatite, spinello nero, mica bruna e clinopirosseno (barabarca), plagioclasio (stecchi), clinopirosseno (viticcio). feldspato potassico subedrale, pertitico, spesso forma geminati semplici, talora ha patchy-zoning, talora è cribroso ed ha bordi in dissoluzione. possiede i caratteri ottici del sanidino (pseudouniassico negativo). mostra alterazione micaceo-argillosa, in alcuni casi cloritizzazione (barabarca), talora parziale sostituzione da parte di carbonato (viticcio). include quarzo, mica bruna e clinopirosseno (viticcio). plagioclasio da anedrale (viticcio) a subedrale, forma geminati polisintetici, ed è generalmente cribroso. ha alterazione micaceo-argillosa. include quarzo e mica bruna (viticcio). mica bruna pleocroica dal giallo bruno al bruno scuro, talora scheletriforme (barabarca, viticcio), talora ossidata, possiede uno zoning ottico compatibile con un aumento dal rapporto mg/fe verso il bordo dei cristalli. mica bianca debolmente pleocroica da incolore a giallo chiaro, spesso forma glomeruli (barabarca). talora è ossidata e in alcuni casi cloritizzata (mad.na delle grazie). clinopirosseno da anedrale a subedrale (stecchi), ha pleocroismo da incolore a giallo a verde corrispondente a termini diopsidico–augitici. talora forma geminati semplici, possiede uno zoning ottico compatibile con aumento dal rapporto fe/mg verso il bordo dei cristalli, talora mostra patchy-zoning, è cribroso (barabarca), e forma glomeruli. le alterazioni più diffuse sono la cloritizzazione, l’argillificazione e l’ossidazione. include mica bruna (barabarca). spinello nero da anedrale a euedrale anche nella stessa roccia (mad.na delle grazie, stecchi), talora è cribroso (barabarca) e con anse da rifusione (viticcio). spesso è ossidato. ematite da anedrale a subedrale (stecchi), contiene essoluzioni (viticcio). granato anedrale, giallo bruno caratteristico di termini ricchi in ferro. tab. 5 sinottica delle caratteristiche mineralogiche e petrografiche degli inclusi litici delle eolianiti del presente lavoro. mineralogical and petrographical features of the lithics included in the aeolianites of this work. paragenesi tessitura protoliti origine qtz isotropa quarziti x x x x qtz, miche scistosa quarzoscisti metamorfica x x x miche, qtz, kf, pl scistosa micascisti x x qtz, miche, kf(*), pl(*) isotropa areniti sedimentaria x x x x kf, pl, cpx isotropa granodioriti plutonica x x intergranulare qtz, kf, pl, cpx/miche(**) variolitica graniti l.s. ipoabissale x x x x porfiritica v it ic ci o b ar ab ar ca s te cc hi m . d el le g ra zi e (*) specie presenti solo a viticcio; (**) a viticcio è presente solo mica bruna, mentre nelle altre località è presente solo cpx. le eolianiti dell’isola d’elba ... fig. 9 caratteri microscopici delle eolianiti elbane. a) sezione subassiale di elphidium sp. (foraminifero bentonico) nelle areniti di viticcio (campione vi 8). nicol paralleli; b) bioclasti costituiti da alghe corallinacee (b) associati a frammenti ignei a feldspati con struttura porfirica e tessitura variolitica, di origine ipoabissale (i). si noti il basso grado di sorting della roccia. madonna delle grazie (campione mg 2). nicol paralleli; c) incluso igneo olocristallino inequigranulare (p), costituito da cristalli di quarzo e feldspati e macrocristalli di feldspati con incipiente seriticizzazione, di origine plutonica. esso è associato ad inclusi quarzo-arenitici (s), contenenti lamelle di mica bruna, di origine sedimentaria. si noti l’orlo di cemento isopaco, di prima generazione, che circonda il frammento igneo (c1) e il cemento a mosaico, di seconda generazione, che riempie gli spazi intergranulari (c2). viticcio (campione vi 3) nicol incrociati; d) mirmechite (contornata) inclusa nelle areniti di viticcio (campione vi 1). nicol incrociati. mirmechiti sono state rinvenute al monte capanne (soprattutto nella fascia di contatto tra il plutone granodioritico e le rocce incassanti) e a porto azzurro (all’interno dei filoni granodioritici) (marinelli, 1959); e) pseudomorfosi da parte di carbonato, spinta fino alla quasi totale ricristallizzazione con obliterazione della paragenesi originaria, in un incluso di quarzo-arenite (contornato). viticcio (campione vi 6). nicol incrociati; f) cemento “a dente di cane” che contorna sia i clasti carbonatici di origine organica (frammenti di alghe corallinacee), sia quelli silicatici (granuli quarzoso-feldspatici). madonna delle grazie (campione mg 5). nicol paralleli. microscopic features of the aeolianites of the elba island. a) sub-assial section of elphidium sp. (benthonic foraminiphera) in the viticcio arenites (sample vi 8). parallel polars; b) bioclasts (b), built up by coralline algae, are associated to feldspar-bearing hypabissal fragments (i), having porphyritic texture and variolitic fabric. note the low degree of sorting of the rock. madonna delle grazie (sample mg 2). parallel polars; c) a holocrystalline, inequigranular plutonic enclosed (p), built up by quartz and feldspar crystals together with feldspar macro-crystals showing incipient sericitization. it is associated with quartz-arenitic sedimentary enclosed (s), which contain lamellae of brown mica. note the rim of first-generation isopachous cement that surrounds the igneous fragment (c1) along with the second-generation “mosaic” cement that fills the intergranular pores (c2). viticcio (sample vi 3) crossed polars; d) a mirmechite (contoured) inside the viticcio arenites (sample vi 1). crossed polars. mirmechites have been found in the monte capanne area (mainly at the contact between the granodioritic pluton and the country rocks) and in the porto azzurro area (inside the granodioritic necks) (marinelli, 1959); e) carbonate pseudomorph after a quartz-arenitic enclosed (contoured). recrystallization and consequent obliteration of the original paragenesis are almost complete. viticcio (sample vi 6). crossed polars; f) “dogtooth” cement surrounding both the organogenous carbonate clasts (fragments of coralline algae) and the silicate clasts (quartzand feldspar-bearing grains). madonna delle grazie (sample mg 5). parallel polars. d e ignee plutoniche, a composizione granodioritica; aggregati di quarzo, feldspato potassico, plagioclasio, clinopirosseno, con tessitura variabile da intergranulare a variolitica fino a porfiritica: si tratta di frammenti di rocce ignee ipoabissali, a composizione granitica l.s. in generale, fenomeni di alterazione (ossidazione, cloritizzazione, sericizzazione e argillificazione) a spese degli inclusi litici sono comuni in tutti gli affioramenti e riguardano soprattutto le quarzo-areniti e le ipoabissaliti. 5.1.4. cemento sono presenti due generazioni di cemento. un cemento di prima generazione, formato da carbonato di calcio isopaco, spesso pochi µm, contorna i granuli assumendo la forma di “dente di cane”. esso si osserva piuttosto raramente in alcuni campioni di viticcio (fig. 9c), mentre risulta più frequente in quelli di mad.na delle grazie (fig. 9f). un cemento di seconda generazione, formato da carbonato di calcio disposto a mosaico (sparite), riempie generalmente le cavità tra i granuli. il cemento sparit ico ha grana variabile da medio-grossolana (barabarca) a medio-fine (viticcio) a fine (mad.na delle grazie, stecchi). 5.2. analisi morfometrica in sezione sottile dei granuli di quarzo l’analisi morfometrica è stata condotta su granuli di quarzo in sezione sottile. i risultati analitici sono quindi riferiti alle due dimensioni. l’analisi è consistita nella misurazione dei diametri maggiore e minore dei granuli, mediante i quali è stata calcolata la sfericità secondo la formula di riley. l’arrotondamento dei granuli è stato valutato utilizzando le tavole comparative di powers (1953). il quarzo è stato scelto come specie mineralogica di confronto in virtù della sua ubiquità nelle rocce in studio e della sua pressoché assoluta indipendenza dai fenomeni di alterazione post-deposizionale, i quali verosimilmente hanno avuto entità diversa in ciascuno degli affioramenti. l’analisi morfometrica è stata eseguita su cristalli di quarzo freschi e integri. non sono stati, quindi, presi in esame cristalli mostranti geminazione, estinzione ondulata, segni di disgregazione meccanica o bordi riassorbiti. sono stati esclusi anche i cristalli raggruppati in glomeruli o appartenenti ad inclusi litici. per ogni campione sono stati analizzati più di cento granuli di quarzo. 5.2.1. dimensioni tra tutte le località del presente studio, i campioni di barabarca sono caratterizzati in generale dalle dimensioni minori e dalla minore dispersione dei dati (dmax = 75 ÷ 375 µm, dmin = 50 ÷ 200 µm). per contro, i campioni di viticcio hanno le dimensioni maggiori e la maggiore dispersione dei dati (dmax = 150 ÷ 1050 µm, dmin = 100 ÷ 525 µm). i parametri dimensionali dei campioni di stecchi (dmax = 50 ÷ 500 µm, dmin = 50 ÷ 400 µm) e mad.na delle grazie (dmax = 75 ÷ 600 µm, dmin = 50 ÷ 350 µm) risultano simili tra loro e intermedi rispetto a quelli delle località precedenti (fig. 10). e’ stata anche determinata la frequenza delle dimensioni dei granuli di quarzo in ciascun affioramento (fig. 11). a barabarca, la maggiore frequenza corrisponde a dimensioni piuttosto piccole [9 granuli aventi 35 fig. 10 – analisi morfometrica dei granuli di quarzo delle eolianiti: diametri massimo e minimo dei granuli, misurati in sezione sottile. morphometric analysis on the quartz grains of the aeolianites: maximum vs minimun diameters of the grains, as measured on rock slides. le eolianiti dell’isola d’elba ... 36 fig. 11 analisi morfometrica dei granuli di quarzo delle eolianiti: frequenza delle dimensioni dei granuli, misurate in sezione sottile, in ciascun affioramento. nella legenda, con lo stesso colore sono indicati i granuli aventi stesse dimensioni. in totale, sono stati analizzati 109 granuli a viticcio, 105 a barabarca, 107 a stecchi e 107 a madonna delle grazie. morphometric analysis on the quartz grains of the aeolianites: frequency of dimensions of the grains in each outcrop, as measured on rock slides. in the caption, each color indicates grains having the same dimensions. in total, 109 grains of viticcio, 105 of barabarca, 107 of stecchi, and 107 of madonna delle grazie have been analyzed. m. d’orefice, r. graciotti & f. capitanio 37 fig. 12 analisi morfometrica dei granuli di quarzo delle eolianiti: frequenza delle classi di sfericità dei granuli in ciascun affioramento. e’ riportato il numero di granuli per ciascuna classe. in totale, sono stati analizzati 109 granuli a viticcio, 105 a barabarca, 107 a stecchi e 107 a madonna delle grazie. morphometric analysis on the quartz grains of the aeolianites: frequency of classes of sphericity of the grains in each outcrop. the number of grains is reported for each class. in total, 109 grains of viticcio, 105 of barabarca, 107 of stecchi, and 107 of madonna delle grazie have been analyzed. le eolianiti dell’isola d’elba ... dimensioni (150 x 100 µm), pari all’8,6 % del totale]. a mad.na delle grazie, la maggiore frequenza risulta spostata verso dimensioni intermedie [7 granuli aventi dimensioni (250 x 100 µm), pari al 6,5 % del totale]. a stecchi, la distribuzione delle frequenze delle misure mostra due massimi [7 granuli aventi dimensioni (150 .x 100 µm) e 9 granuli aventi dimensioni (250 x 150 µm), pari rispettivamente al 7,5 % e all’8,4 % del totale]. per contro, i campioni di viticcio presentano un’ampia omogeneità dei dati senza massimi significativi nella distribuzione della frequenza delle misure. in generale, si evince una marcata differenza nelle dimensioni dei grani di quarzo tra gli affioramenti del promontorio del m. calamita e quelli del golfo di viticcio. 5.2.2. sfericità in generale, i granuli di quarzo presentano un massimo di frequenza in corrispondenza dei valori di sfericità più bassi o intermedi (0,10 ÷ 0,60) (fig. 12). per contro, nelle classi di sfericità più alte la frequenza dei grani è nettamente minore. in particolare, per quanto concerne i valori di sfericità compresi tra 0,70 e 1,00, viticcio possiede un numero di grani leggermente maggiore rispetto agli altri affioramenti del m. calamita, i quali invece risultano molto simili tra loro. in definitiva, le classi di sfericità maggiormente rappresentate sono quelle aventi valori compresi tra 0,20 e 0,40. i campioni di mad.na delle grazie hanno una distribuzione spostata verso valori di sfericità maggiori rispetto agli altri. i campioni di barabarca e viticcio, invece, mostrano una dispersione dei valori relativamente più elevata. 5.2.3. arrotondamento anche i valori stimati dell’arrotondamento (fig. 13) risultano piuttosto uniformi per i vari affioramenti: infatti, si ha una netta prevalenza di granuli di quarzo con grado di arrotondamento da “subangoloso” a “subarrotondato”. nel dettaglio, a stecchi si ha la massima percentuale relativa di granuli appartenenti alla classe “subangoloso” (53,3 %), cui corrisponde la minima percentuale di granuli della classe “subarrotondato” (29,0 %); in questo affioramento, la distribuzione delle classi risulta la più omogenea, in quanto sia la classe “arrotondato” che quella “angoloso” raggiungono valori piuttosto elevati e prossimi tra loro (9,3 % e 8,4 %, rispettivamente). a mad.na delle grazie, si ha ancora una netta prevalenza dei granuli appartenenti alla classe “subangoloso” (52,3 %) rispetto a quelli della classe “subarrotondato” (32,7 %). a barabarca la maggior parte dei granuli è pressoché ugualmente distribuita tra le classi “subangoloso” (44,8 %) e “subarrotondato” (43,8 %). a viticcio, invece, i granuli appartenenti alla classe “subarrotondato” sono leggermente superiori a quelli della classe “subangoloso”. in sostanza, tra gli affioramenti del promontorio del m. calamita e del golfo di viticcio si apprezza una certa differenza solo per quanto concerne i granuli della classe “arrotondato”, che in quest’ultima località raggiungono la loro frequenza minima. 5.3. inclusi litici: analisi quantitativa l’analisi degli inclusi litici è consistita nell’identificazione delle specie mineralogiche costituenti, nella 38 fig. 13 analisi morfometrica dei granuli di quarzo delle eolianiti: percentuale delle classi di arrotondamento dei granuli per ciascun affioramento. in totale, sono stati analizzati 109 granuli a viticcio, 105 a barabarca, 107 a stecchi e 107 a madonna delle grazie. morphometric analysis on the quartz grains of the aeolianites: percentage of classes of roundness of the grains in each outcrop. in total, 109 grains of viticcio, 105 of barabarca, 107 of stecchi, and 107 of madonna delle grazie have been analyzed. a) viticcio b) barabarca c) stecchi d) m. delle grazie m. d’orefice, r. graciotti & f. capitanio definizione delle tessiture e nella determinazione dei rapporti quantitativi relativi delle diverse tipologie di incluso. sono stati selezionati inclusi freschi e integri, escludendo quelli in cui i fenomeni di alterazione e/o ricristallizzazione hanno obliterato la paragenesi originaria. particolare attenzione è stata posta nel caso in cui diversi frammenti della stessa tipologia fossero adiacenti gli uni agli altri: verosimilmente, essi provengono da un solo incluso disgregato in più parti per azione meccanica (questo accade frequentemente a viticcio). per ogni affioramento sono stati analizzati più di cento inclusi. in tutti gli affioramenti (fig. 14), i frammenti di rocce sedimentarie (quarzo-areniti provenienti da rocce flyschoidi) sono preponderanti quantitativamente. a stecchi, l’abbondanza delle quarzo-areniti raggiunge il valore massimo dell’83,6 %, cui corrisponde la percentuale minima di rocce ignee (3,6 %), mentre la percentuale delle rocce metamorfiche è del 12,7 %. a mad.na delle grazie, le areniti sedimentarie (75,0 %) sono ancora prevalenti rispetto alle rocce ignee (13,4 %) e a quelle metamorfiche (11,6 %). a barabarca, le quarzo-areniti costituiscono il 72,6 % degli inclusi, seguite dalle rocce ignee (16,2 %), mentre la percentuale di rocce metamorfiche si mantiene pressappoco costante (11,1 %, in prevalenza quarziti r ispetto a quarzoscisti). a viticcio, la distribuzione delle diverse tipologie di inclusi risulta molto simile a quella di barabarca: la sola differenza consiste nella maggiore percentuale di scisti (quarzoscisti e micascisti) rispetto alle quarziti. di rilevante interesse è la quasi totale assenza di frammenti carbonatici di origine inorganica. 5.4. litologia del substrato per accertare una eventuale influenza delle rocce del substrato nella composizione degli elementi granulari che costituiscono i depositi eolici, è stata definita la distribuzione dei litotipi in ciascuno degli affiora39 fig. 14 classificazione genetica e quantità percentuali degli inclusi litici delle eolianiti. in totale, sono stati analizzati 133 inclusi a viticcio, 117 a barabarca, 110 a stecchi e 112 a madonna delle grazie. genetic classification and quantitative percentages of lithics included inside the aeolianites. in total, 113 lithics of viticcio, 117 of barabarca, 110 of stecchi, and 112 of madonna delle grazie have been analyzed. a) viticcio b) barabarca c) stecchi d) m. delle grazie le eolianiti dell’isola d’elba ... menti del presente studio. la misura della distribuzione dei litotipi del substrato è stata condotta mediante l’utilizzo di analisi spaziali quantitative in ambiente gis (åberg et al., 2007), applicate alla carta geologica dell’isola d’elba alla scala 1:25.000 (barberi et al., 1967a). per ogni deposito, quindi, è stato delimitato il relativo bacino idrografico, all’interno del quale è stata misurata la percentuale dei vari litotipi affioranti. i risultati rivelano una eterogeneità litologica nei diversi bacini (fig. 15). infatti, a barabarca predominano i litotipi arenacei e carbonatici che costituiscono il flysch cretacico (55,2 %) rispetto alle quarziti del verrucano (43,3 %). a stecchi, la situazione è leggermente diversa, con le rocce del flysch cretacico (38,8 %) subordinate alle quarziti del verrucano (56,6 %). per contro, a mad.na delle grazie la litologia del substrato è più complessa rispetto ai due bacini precedenti: sono presenti prevalentemente carbonati triassici di ambiente evaporitico (45,6 %), oltre agli scisti e filladi del calamita (22,2 %) e alle rocce del flysch cretacico (21,4 %). il bacino viticcio si differenzia ulteriormente dagli altri, poiché è costituito, quasi nella stessa percentuale, da litotipi appartenenti al flysch cretacico (55,0 %) e da porfidi (45,0 %). 6. discussione 6.1. caratteri sedimentari le eolianiti sono caratterizzate da diverse strutture sedimentarie, tra le quali la più importante ai fini diagnostici è la stratificazione incrociata a grande scala. ad essa sono associati altri aspetti sedimentari, come: • l’elevata inclinazione dei foreset, in genere immergenti verso terra con pendenze fino a 35°; • l’orientamento molto variabile dei singoli foreset nell’ambito di uno stesso affioramento. queste peculiarità, unite alla presenza di intercalazioni di depositi di versante e di paleosuoli, sono indicative di un ambiente deposizionale continentale, in gran parte dominato dai processi eolici. ulteriori indagini microscopiche, finalizzate a verificare la presenza nelle eolianiti di strutture a piccola scala tipiche dei depositi eolici, quali laminazioni di tipo pinstripe (hunter, 1977; 1993), non hanno dato esito positivo. l’eventuale assenza, in sezione sottile, di laminazioni di questo tipo può essere probabilmente attribuita a difficoltà nella classazione dei granuli. infatti, la presenza di un’abbondante frazione bioclastica, eterogenea in forma, dimensioni e densità, rende problematico il sorting dimensionale dei granuli (kindler & davaud, 2001; le guern & davaud, 2005). inoltre, alla scala dell’affioramento, il generalizzato stato di alterazione delle sezioni delle eolianiti esposte, ha reso difficoltosa l’osservazione di stratificazione da grainflow o da grainfall. per quanto concerne la disposizione dei corpi sedimentari in esame, il loro accumulo a ridosso degli acclivi versanti rocciosi della fascia costiera ed il loro protendersi nell’entroterra elbano, in alcuni casi oltre i 100 m di quota s.l.m., induce a ritenere che questi litosomi siano stati originati da climbing dunes. le superfici s1 e s2, osservate alla spiaggia della madonna (fig. 2b-c), sono riconducibili a superfici d’erosione generate da intense dinamiche di versante, in 40 fig. 15 classificazione genetica e quantità percentuali dei tipi litologici del substrato affiorante nei bacini idrografici dei depositi eolici in esame (dati desunti dalla carta geologica dell’isola d’elba 1:25.000 – barberi et al., 1967a). la varietà del substrato è tale da comprendere rocce sedimentarie appartenenti a diverse formazioni (qtz-areniti: verrucano, triassico; calcari e dolomie: evaporiti, triassico; areniti, calcari e marne: flysch, cretacico), oltre a rocce ignee (graniti e granodioriti) e metamorfiche (scisti e gneiss del calamita). genetic classification and quantitative percentages of lithotypes of the substrate outcropping in the hydrographical basins of the aeolian deposits (data derived from the geological map of the elba island 1:25.000 – barberi et al., 1967a). the variability of the substrate is high, as it includes sedimentary rocks belonging to several formations (qtz-arenites: verrucano, triassic; limestones & dolostones: evaporites, triassic; arenites, limestones & marls: flysch, cretaceous), together with igneous (granites & granodiorites) and metamorphic rocks (scists & gneisses of monte calamita). a) viticcio b) barabarca c) stecchi d) m. delle grazie m. d’orefice, r. graciotti & f. capitanio grado di troncare la porzione superiore della duna accumulata contro il versante e di ridistribuire i sedimenti verso valle. questo aspetto è ben documentato nella superficie superiore (s2), che corrisponde al troncamento della parte superiore della duna “b”, sulla quale poggiano detriti stratificati di versante. nel caso della spiaggia della madonna, l’angolo di arrampicata (angle of climbing) dei corpi dunari, ottenuto dal rapporto tra il tasso di migrazione sottovento della duna e il tasso di accumulo verticale (rubin & hunter, 1982), risulta pari a circa 10°. il valore non eccessivamente elevato di quest’angolo può spiegare perché si è preservata solo la porzione inferiore del pacco di foreset. le superfici di discontinuità, di ordine minore, presenti all’interno dei set a stratificazione incrociata sono superfici di riattivazione dovute ad una interruzione periodica della migrazione della duna e all’erosione sul lato frontale (lee face) della stessa ad opera di venti subordinati rispetto a quelli dominanti. riguardo le concrezioni intrasedimentarie (fig. 4), una possibile interpretazione genetica è che si tratti di rizoconcrezioni, cioè impronte calcificate di apparati radicali appartenenti ad un’antica vegetazione dunare. a questo proposito, occorre tener presente che le radici possono svilupparsi nel terreno non solo in direzione verticale ma anche orizzontale. tuttavia, una interpretazione alternativa è quella avanzata da mazzanti & parea (1977) e parea (1984), per cui le concrezioni sub-orizzontali sarebbero da mettere in relazione con le acque della falda freatica in lento deflusso verso le quote più basse entro la porzione basale dei sedimenti. invece, le concrezioni verticali sarebbero da attribuire essenzialmente al percolamento delle acque meteoriche, attraverso la parte superiore degli stessi sedimenti, durante la discesa verso la falda freatica. infine, mc bride & parea (2001) ammettono la possibilità che molte concrezioni verticali si siano originate da rizoconcrezioni, composte inizialmente da calcite micritica, interessate successivamente da precipitazione di calcite spatica ad opera delle acque vadose percolanti. ciò spiegherebbe il considerevole sviluppo laterale e la coalescenza di queste strutture sedimentarie. per quanto concerne il paleosuolo rosso intercalato alle eolianiti affioranti tra barabarca e stecchi (fig. 5a), la sua origine pedogenetica è testimoniata da un’intensa rubefazione, da una decarbonatazione molto spinta, dall’esistenza di materia organica e dall’arricchimento in argilla. il paleosuolo, probabilmente sviluppatosi a spese dei sottostanti depositi eolici con livelli detritici intercalati, è stato classificato da cremaschi & trombino (1998) come un “red mediterranean soils – xeralfs”. infine, i livelli detritici associati alle eolianiti in diverse posizioni stratigrafiche (fig. 5b, 6a-b), sono da riferire alla vicinanza di un versante in degradazione, che ha fornito il materiale detritico in condizioni climatiche verosimilmente più fredde e più aride di quelle attuali. infatti, la formazione di questi detriti può essere favorita dalla scarsa copertura vegetale associata a processi crioclastici più o meno intensi. questa ipotesi è confermata dalla presenza, nell’affioramento di spiaggia della madonna, di detriti di versante clinostratificati secondo strati piano-paralleli (éboulis ordonnés) noti in letteratura per essersi deposti in un ambiente freddo ed arido, caratterizzato da versanti quasi del tutto denudati. 6.2. caratteri bio-minero-petrografici il costituente micropaleontologico dei campioni analizzati nel presente studio (tab. 2), mostra la prevalenza di miliolidae accanto a forme quali lobatula lobatula (walker & jacob), elphidium advenum (cushmann), planorbulina mediterranensis (cushmann) e rosalina bradyi (cushmann), tutte di acque relativamente basse e legate al popolamento vegetale, come pure di discorbis globularis (d’orbigny), forma sessile infralitorale (blancvernet, 1969; murray, 1973; violanti et al., 1988). questa associazione microfaunistica è riferibile ad un ambiente marino infralitorale temperato caldo, dove la componente vegetale di alghe e/o di posidonia è non trascurabile. da un punto di vista generale, la mineralogia delle eolianiti non è direttamente confrontabile con quella del substrato, affiorante nei bacini idrografici in cui sono compresi i depositi eolici. a barabarca, e in quantità minore a mad.na delle grazie, le eolianiti contengono granato (con caratteri ottici corrispondenti a termini ricchi in ferro: andradite-grossularia): considerando la litologia del promontorio del m. calamita, le più probabili rocce-madri dei granati sono le cornubianiti e in subordine gli scisti. ancora, a viticcio il granato non è stato rinvenuto, e risulta pure assente nelle rocce del substrato. per quanto riguarda l’anfibolo (con i caratteri ottici dell’orneblenda l.s.), quello delle eolianiti di stecchi può provenire dalle anfiboliti presenti nel promontorio del m. calamita, mentre la provenienza di quello di viticcio rimane incerta, in quanto non sono stati finora segnalati in letteratura rinvenimenti di anfibolo nel substrato del golfo di viticcio. la mancanza di correlazione minero-petrografica tra le eolianiti e il substrato dei bacini idrografici in cui sono comprese, è evidente anche dall’analisi degli inclusi litici delle eolianiti. infatti, il contenuto percentuale di inclusi sedimentari, ignei e metamorfici si mantiene pressappoco costante in tutti gli affioramenti appartenenti sia allo stesso settore (barabarca, stecchi, mad.na delle grazie) sia a settori distinti (golfo di viticcio e promontorio del calamita). per contro, la litologia del substrato è estremamente variabile non solo da un’area all’altra (ad esempio, nel golfo di viticcio il substrato è composto per metà circa da rocce ignee, del tutto subordinate negli altri affioramenti esaminati), ma anche all’interno di una stessa area (ad esempio, a mad.na delle grazie un quarto circa del substrato è composto da rocce metamorfiche, praticamente assenti negli altri affioramenti). le indagini morfometriche eseguite in sezione sottile sulla frazione fine quarzosa delle eolianiti hanno rivelato alcune tendenze. infatti, i dati ottenuti risultano piuttosto omogenei, soprattutto per quanto riguarda la sfericità (medio-bassa) e l’arrotondamento (da “subangoloso” a “subarrotondato”). alcune differenze si riscontrano per le dimensioni dei grani misurate al microscopio: tra le località del presente studio, barabarca possiede la popolazione più omogenea e a dimensioni minori, mentre viticco possiede la popolazione più eterogenea che raggiunge le dimensioni mag41le eolianiti dell’isola d’elba ... giori. le analisi morfometriche suggeriscono una certa differenza tra gli affioramenti del m. calamita e quelli di viticcio. infatti, i campioni prelevati nelle località di barabarca, stecchi e mad.na delle grazie, presentano caratteristiche morfometriche piuttosto omogenee tra loro e lievemente differenti da quelli di viticcio. queste differenze morfometriche potrebbero essere imputate alla diversa collocazione geografica ed alla diversa esposizione dei due settori presi in esame (promontorio del m. calamita e golfo di viticcio). in particolare, i fattori maggiormente influenti potrebbero essere stati la differente granulometria del materiale messo a disposizione dalla dinamica marina ed in misura minore da quella fluviale, oltre alla diversa capacità di trasporto e direzione dei venti dominanti. il cemento isopaco a “dente di cane” (fig. 9f) è indicatore di condizioni freatiche, che possono essere considerate di tipo meteorico (ambiente continentale). infine, la quasi totale assenza di clasti carbonatici all’interno delle eolianiti è un elemento rilevante. pur essendo gli extraclasti assai poco resistenti alla degradazione meccanica e chimica, è difficile ammettere una loro completa assenza. in ogni caso si sottolinea che le rocce carbonatiche, seppur ben rappresentate nel settore del m. calamita esaminato, costituiscono una minima percentuale nell’intero contesto geologico dell’isola d’elba. di fatto, la composizione mineralogica delle eolianiti punta ad una provenienza dei sedimenti da litotipi quarzo-arenitici (flyschoidi), frammisti a materiale bioclastico originatosi in ambiente di mare poco profondo. in quest’ambiente, sotto l’influsso della dinamica marina, è avvenuta la redistribuzione dei sedimenti provenienti dall’erosione del substrato continentale elbano e la commistione con quelli di origine marina. in definitiva, l’area sorgente degli elementi costitutivi delle eolianiti in studio, può essere individuata nei bassi fondali marini della piattaforma continentale circostante l’isola d’elba. 7. conclusioni i depositi eolici affioranti nel tratto di costa occidentale del m. calamita e nel golfo di viticcio dell’isola d’elba si sono formati in periodo di basso stazionamento marino. infatti, la loro prosecuzione per diversi metri al di sotto dell’attuale livello del mare e la loro erosione ad opera dell’odierna dinamica marina, confermano un equilibrio di questi corpi sedimentari con una linea di costa più avanzata di quella attuale. inoltre, anche i versanti rocciosi su cui tali depositi poggiano in discordanza e i fondovalle che essi stessi colmano, appaiono morfologicamente legati ad un livello di base più basso di quello odierno. lo sviluppo delle dune eoliche in esame è strettamente connesso alla disponibilità di un’abbondante quantità di sabbia da parte dei venti dominanti, i quali debbono essere dotati di una sufficiente capacità di trasporto per rimuovere le particelle di sabbia o di ghiaia minuta. tali particelle, comunque, affinché possano essere asportate dal vento, devono essere abbastanza asciutte e non devono aver subito nel frattempo processi di stabilizzazione da parte della vegetazione o di cementazione ad opera delle acque meteoriche circolanti o di altri fenomeni diagenetici. tutte queste specifiche condizioni possono verificarsi nel corso di una fase di regressione marina, durante la quale lentamente e progressivamente emerge dal mare un fondale sabbioso. tale fondo, appartenente alla vasta piattaforma continentale toscana oggi sommersa, costituisce un’idonea zona d’alimentazione di questi materiali, i quali, sospinti dai venti dominanti, sono in grado di risalire i versanti e le preesistenti valli fluviali fino ad oltre 100 m sul livello del mare attuale. la presenza delle eolianiti elbane, sia sulle coste esposte ad ovest e sia su quelle esposte ad est, induce ad ipotizzare una provenienza dei venti dominanti oltre che dai quadranti occidentali, anche da quelli orientali. ciò è in accordo con quanto osservato da antonioli & ferranti (1992) nei riguardi delle eolianiti affioranti lungo il tratto meridionale del golfo di orosei (sardegna orientale). l’ipotesi che le eolianiti elbane si siano formate successivamente ad un periodo caldo è in accordo con la presenza in questi litotipi di bioclasti appartenenti ad associazioni microfaunistiche totalmente di ambiente marino litorale temperato-caldo. i sedimenti accumulati lungo la piattaforma continentale durante una fase calda interglaciale, sarebbero stati erosi dai venti dominanti nel corso della successiva fase di basso stazionamento marino e accumulati nell’entroterra, insieme ai materiali rimaneggiati dai corsi d’acqua, sotto forma di cordoni dunari. pertanto, in base a quanto su esposto, alle età radiometriche dei paleosuoli intercalati nelle eolianiti aff ioranti in località mad.na delle grazie e cala cancherelli ed alla presenza di manufatti musteriani all’interno dei paleosuoli, si può ipotizzare che la messa in posto dei sedimenti del presente studio sia legata, in accordo con cremaschi & trombino (1998), a fasi fredde ed aride registratesi nel corso degli stadi isotopici 4 e 2 dell’ultimo glaciale. l’età di formazione dei depositi in esame è quindi riferibile al pleistocene superiore. il paleosuolo si è probabilmente sviluppato durante una fase interstadiale meno fredda e più umida (stadio isotopico 3), che ha favorito la crescita di una vegetazione dunare e la pedogenizzazione delle eolianiti. la presenza, nelle aree esaminate, di depositi di versante, alternati ad eolianiti, sta ad indicare una temporanea disattivazione della sedimentazione eolica. essa potrebbe coincidere con l’inizio di una deposizione, ad opera dei processi fluvio-denudazionali di versante, di materiali provenienti in parte dal dilavamento delle sabbie eoliche precedentemente deposte ed in parte dall’erosione dei soprastanti versanti modellati nel substrato roccioso. ringraziamenti si ringrazia g. ventura per le analisi micropaleontologiche, m. cacopardo per le sezioni sottili e s. falcetti per il disegno. un ringraziamento particolare va a m. coltorti per i preziosi e puntuali suggerimenti forniti, nonché a c. carrara e f. antonioli per la revisione critica del manoscritto. 42 m. d’orefice, r. graciotti & f. capitanio bibliografia åberg u., cipolloni c., d’orefice m. & graciotti r. (2007) parametri morfometrici come supporto all’analisi dei depositi eolici dell’isola d’elba. atti prima riunione del gruppo di geologia informatica, sezione della società geologica italiana, s. leo, 31.05.06-01.06.06. rend. soc. geol. it., 4, pp. 79-80. aiello e., bruni p. & sagri m. (1977) depositi canalizzati nei flysch cretacei dell’isola d’elba. boll. soc. geol. it., 96, pp. 297-329. antonioli f. & ferranti l. (1992) geomorfologia costiera e subacquea e considerazioni paleoclimatiche sul settore compreso tra s. maria navarrese e punta goloritzé (golfo di orosei, sardegna). giornale di geologia, ser. 3a, 54 (2), pp. 65-89. barberi f., giglia g., innocenti f., marinelli g., raggi g., ricci c.a., squarci p., taffi l. & trevisan l. (1967a) carta geologica dell’isola d’elba scala 1:25000. c.n.r. roma. barberi f., innocenti f. & ricci c.a. (1967b) il complesso scistoso di capo calamita (isola d’elba). atti soc. tosc. sci. nat., mem. serie a, 74, pp. 579-617. barberi f., dallan l., franzini m., giglia g., innocenti f., marinelli g., raggi g., squarci p., taffi l. & trevisan l. (1969) note illustrative della carta geologica d’italia alla scala 1:100.000. foglio 126 isola d’elba. min. ind. comm. art. serv. geol. it., 41 pp. blanc-vernet l. (1969) contribution à le etude des foraminiferes de mediterranèe. trav. st. mar. endoume, 64, pp. 1-128. bonatti s. & marinelli g. (1951) appunti di litologia elbana. boll. soc. geol. it., 70, pp. 473-489. bortolotti v., fazzuoli m., pandeli e., principi g., babbini a. & corti s. (2001) geology of central and eastern elba island, italy. ofioliti, 26 (2a), pp. 97150. centamore e., dramis f. & federici p. r. (1988) superfici di spianamento relitte e vicende morfoneotettoniche dell’isola d’elba. suppl. geogr. fis. dinam. quat., 1, pp. 155-160. cornamusini g., lazzarotto a., merlini s. & pascucci v. (2002) eocene-miocene evolution of the corsica basin-tuscan shelf area (north tyrrhenian sea) through crop-mare deep seismic analysis. boll. soc. geol. it., vol. sp., 1, pp. 769-787. cremaschi m. & trombino l. (1998) eolianites, sea level changes and paleowinds in the elba island (central italy) during late pleistocene. in: busacca a.j. (ed), dust aerosols, loess soils and global change. washington state university college of agriculture and home economics, pullman, wa, pp.131-134. daniel j.m. & jolivet l. (1995) detachment faults and pluton emplacement: elba island (tyrrhenian sea). bull. soc. géol. france, 166, pp. 341-354. desio a. (1922) qualche osservazione morfologica sull’isola d’elba. l’universo, 3 (10), pp. 671-676. dini a., innocenti f., rocchi s., tonarini s. & westerman d.s. (2002) the magmatic evolution of late miocene laccolite – pluton – dyke granitic complex of elba island, italy. geol. mag., 139, pp. 257-279. ferrara g. &. tonarini s. (1985) radiometric geochronology in tuscany: results and problems. rend. soc. it. mineral. petrol., 40, pp. 111-124. ferrara g. &. tonarini s. (1993) l’isola d’elba: un laboratorio di geocronologia. mem. soc. geol. it., 49, pp. 227-232. foresi l. m., cornamusini g., bossio a., ferrandini j., ferrandini m., mazzanti r., mazzei r. & salvatorini g. (2000) the miocene sedimentary succession of the pianosa island, northern tyrrhenian sea. atti convegno “evoluzione geologica e geodinamica dell’appennino”. foligno, 16-18 febbraio 2000, pp. 155-157. garfagnoli f., menna f., pandeli e. & principi g. (2005) the porto azzurro unit (mt. calamita promontory, south-eastern elba island, tuscany): stratigraphic, tectonic and metamorphic evolution. boll. soc. geol. it., vol. sp., 3, pp. 119-138. gioli g. (1894) il sottosuolo delle pianure di pisa e livorno. boll. soc. geol. it., 13, pp. 210-233. graciotti r., foresi l. & pantaloni m. (2002-2003) lineamenti geomorfologici dell’isola di pianosa. soc. tosc. sci. nat., mem. serie a, 108, pp. 95111. hunter r.e. (1977) basic types of stratification in small eolian dunes. sedimentology, 24, pp. 361-387. hunter r.e. (1993) an eolian facies in the ste. genevieve limestone of southern indiana. in: keith b.d. & zuppann c. (eds.) mississippian oolites and modern analogs. am. assoc. petrol. geol. stud. geol., 35, pp. 31-48. jateau m., michard a., zimmermann j.l. & albarede f. (1984) isotopic heterogeneities in the granitic intrusion of monte capanne (elba island, italy) and dating concepts. j. petrol., 25, pp. 532-545. keller j.v.a. & pialli g. (1990) tectonics of the island of elba: a reappraisail. boll. soc. geol. it., 109, pp. 413-425. kindler p. & davaud e. (2001) recognizing eolianites in thin section. review and case study – the lower cretaceous chambotte formation, salève chain, southeastern france. in: abegg f.e., harris p.m., loope d.b. (eds.) modern and ancient carbonate eolianites sedimentology: sequence stratigraphy, and diagenesis. sepm, spec. publ., 71, pp. 141-150. le guern p. & davaud e. (2005) recognition of ancient carbonate wind deposits: lessons from a modern analogue, chrissi island, crete. sedimentology, 52, pp. 915-926. lotti b. (1910) geologia della toscana. mem. descr. carta geol it., 13, 484 pp. maineri c., benvenuti m., costagliela p., dini a., lattanti p., ruggieri g. & villa i. m. (2003) sericitic alteration at the la crocetta deposits (elba island, italy): interplay between magmatism, tectonic and idrotermal activity. mineralium deposita, 38, pp. 67-86. marinelli g. (1955) le rocce porfiriche dell’isola d’elba. atti soc. tosc. sci. nat., mem. serie a, 62, pp. 269-418. marinelli g. (1959) le intrusioni terziarie dell’isola d’elba. atti soc. tosc. sci. nat., mem. serie a, 66, pp. 50-253. mazzanti r. & parea g.c. (1977) erosione della 43le eolianiti dell’isola d’elba ... “panchina” sui litorali di livorno e di rosignano. boll. soc. geol. it., 96, pp. 457-489. mazzanti r. (1983) il punto sul quaternario della fascia costiera e dell’arcipelago di toscana. boll. soc. geol. it., 102, pp. 419-556. mc bride e.f. & parea g.c. (2001) origin of highly elongate, calcite-cemented concretions in some ital ian coastal beach and dune sands . j. sediment. res., 71 (1), pp. 82-87. merciai g. (1926) sull’origine eolica di una parte della panchina del litorale tosco-laziale. boll. soc. geol. it., 45 (1), pp. 81-85. murray j.w. (1973) distribution and ecology of living benthic foraminiferids. heineman educ. books, 274 pp. pandeli e. & puxeddu m. (1990) paleozoic age for the tuscan upper metamorphic sequences of elba and its implications for the geology of the northern apennines (italy). ecl. geol. helv., 83 (1), pp. 123-142. parea g.c. (1984) modalités de cimentation dans quelques exemples italiens de "panchina" en le beach-rock. travaux de la maison de l’orient, pp. 125-131. pascucci v. (2002) tyrrhenian sea extension between corsica and western tuscany (italy). boll. soc. geol. it., vol. sp., 1, pp. 819-828. pertusati p.c., raggi g., ricci c. a. duranti s. & palmeri r. (1993) evoluzione post-collisionale dell’elba centro-orientale. mem. soc. geol. it., 49, pp. 297312. powers m. c. (1953) a new roundness scale for sedimentary particles. j. sediment. petrol., 23 (2), pp. 117-119. roveri m. & correggiari a. (2004) terrazzi deposizionali sommersi nell’arcipelago toscano (margine orientale del canale di corsica). in: chiocci f.l., d’angelo s., romagnoli c. (eds.) atlante dei terrazzi deposizionali sommersi lungo le coste italiane. mem. descr. carta geol. it., 58, pp. 1126. rühl a. (1912) elba. sond. zeit. gesell. erdkunde zu berlin. berlin. rubin d.m. & hunter r.e. (1982) bedform climbing in theory and nature. sedimentology, 29, pp. 121138. saupe f., marignac c., moine b., sonet j. & zimmerman j. l. (1982) datation par les methodes k/ar et rb/sr de quelques roches de la partie orientale de l’ile d’elbe (province de livourne, italie). bull. minéral., 105, pp. 236-245. strahler a. n. (1957) quantitative analysis of watershed geomorphology. trans. am. geophys. union, 38, pp. 913-920. trevisan l. (1950) l’elba orientale e la sua tettonica di scivolamento per gravità. mem. ist. geol. pal. univ. padova, 16, 39 pp. violanti d., di gironimo i. & saccà d. (1988) rapporti tra tanatocenosi e foraminiferi e biocenosi nel golfo di noto (sicil ia sud-orientale). atti iv simposio ecologia e paleoecologia nelle comunità bentoniche. sorrento 1-5 novembre 1988. museo reg. sci. nat. torino, pp. 773-799. wezel f. c. (1982) the tyrrhenian sea: a rifted kricogernic-swell basin. mem. soc. geol. it., 24, pp. 531-568. 44 ms. ricevuto il 4 gennaio 2007 testo definitivo ricevuto l’8 marzo 2007 ms. received: january 4, 2007 final text received: march 8, 2007 m. d’orefice, r. graciotti & f. capitanio imp.forno_boano riorganizzazione del reticolato idrografico nella collina di torino in relazione alla deformazione quaternaria (nw italy) maria gabriella forno1 & paola boano2 1 dipartimento di scienze della terra, università di torino 2 libero professionista, via asti 13 tonco (at) riassunto: forno m. g. & boano p., riorganizzazione del reticolato idrografico nella collina di torino in relazione alla deformazione quaternaria. (it issn 0394-3356, 2007). il reticolato idrografico, essendo strettamente condizionato dalla direzione di massima pendenza della superficie topografica su cui si sviluppa, risulta un indicatore molto attendibile delle variazioni nell’inclinazione di un determinato settore e di conseguenza può diventare un marker estremamente significativo e sensibile della deformazione recente. nel versante meridionale della collina di torino si osservano numerosi esempi di riorganizzazione di tratti del reticolato idrografico indotti o favoriti dall’evoluzione quaternaria della struttura anticlinale. negli esempi presi in considerazione le modalità di adattamento del reticolato idrografico sono strettamente condizionate dal grado di incisione dei corsi d’acqua, a loro volta connesso con l’entità della deformazione. in particolare in corrispondenza all’asse della sinclinale dell’altopiano di poirino è avvenuta una modestissima variazione di inclinazione indotta dalla deformazione recente: in questi settori il reticolato idrografico, poco inciso entro alla pianura alluvionale, ha potuto adattarsi perfettamente al mutare della superficie topografica, abbandonando le tracce precedenti. e’avvenuta in questo modo una inversione del drenaggio: il corso d’acqua principale, che prima defluiva verso e, ora scorre verso w. lungo i fianchi della struttura anticlinale collinare, è avvenuto invece un più rilevante aumento di inclinazione indotto dalla deformazione recente: in questi settori il reticolato conserva testimonianza degli antichi andamenti che vengono progressivamente catturati dal reticolato idrografico attuale. infine nelle aree prossime all’asse dell’anticlinale si è verificato un sensibile aumento di inclinazione indotto dalla deformazione: in queste aree i corsi d’acqua, vincolati all’andamento precedente, non subiscono variazioni di tracciato in pianta ma rispondono con un approfondimento del tratto inferiore per adattarsi al nuovo gradiente. abstract: forno m. g. & boano p., re-organization of hydrographic network in the torino hill connected to quaternary deformation. (it issn 0394-3356, 2007). the hydrographic network, remarkably conditioned by the gradient of the topographic surface, is a very reliable marker of the morphological modifications of an area. it can consequently become a significant and sensible marker of the recent deformation. numerous examples of re-organization of hydrographic network are pointed out in the southern slope of the torino hill: they are induced or favoured by the quaternary evolution of the anticline. in the considered examples the possibility of the adaptation of hydrographic network is conditioned by the watercourses incision degree, connected with the incidence of the deformation. near the syncline axis of the poirino plateau a very weak gradient variation occurred, connected to the recent deformation: in this area the scarcely entrenched hydrographic network is sensible to the gradient variation, and the previous valleys may be left. an inversion of the drainage can therefore occur: the main watercourse, before flowing to the east, now flows to the west. in the sides of the anticline structure of the torino hill a remarkable increase of the inclination took place, connected to the recent deformation: in this area the hydrographic network preserves the evidence of ancient trends, cut progressively by the present network. near the anticline axis a very strong increase of the gradient finally occurred, connected to the recent deformation: in this area the watercourses, entrenched in the previous trends, are not subject to direction variations; on the contrary they are subject to deepening of the lower stretch because of the new gradient. parole chiave: collina di torino, reticolato idrografico, deformazione, pleistocene. keywords: : torino hill, hydrographic network, deformation, pleistocene. il quaternario italian journal of quaternary sciences 19(2), 2006 215-222 1. introduzione gli esempi di riorganizzazione del reticolato idrografico segnalati in questa nota, osservati in occasione dei rilevamenti effettuati per la realizzazione del foglio geologico alla scala 1:50.000 "torino est” nell’ambito del progetto carg, riguardano il versante meridionale della collina di torino al raccordo l’altopiano di poirino (fig. 1). nella collina di torino la successione marina terziaria appare deformata a costituire una struttura anticlinale asimmetrica con asse sw-ne in continuità, verso sud, con la sinclinale dell’altopiano di poirino (bortolami et al., 1969; forno, 1982): l’anticlinale appare delimitata verso nw dal “thrust padano” sepolto, che ne determina la sovrapposizione sui termini più recenti della pianura padana, e verso e dall’importante “fascia di deformazione di rio freddo”, al limite con la struttura complessa dei rilievi del monferrato (piana & polino, 1994; festa et al., 2005). tra le novità emerse negli ultimi anni e confermate dai recenti rilevamenti, la più significativa è rappresentata dal riconoscimento della sensibile deformazione recente della struttura anticlinale, per la quale sono stati ipotizzati valori medi di sollevamento per l’intero pleistocene medio e superiore con ordine di grandezza di 1 mm/anno (boano et al., 2004). tale ricostruzione è desunta dalla presenza nell’area collinare delle tracce di antichi corsi d’acqua, non riferibili al reticolato idrografico collinare ed invece da collegare con il reticolato idro218 m.g. forno & p. boano grafico alpino, che risultano sensibilmente deformate e inglobate nel rilievo. le tracce conservate nel versante meridionale della collina di torino e nell’altopiano di poirino, blandamente deformate, sono da collegare ad un antico percorso del fiume po (a in fig. 1), riferibile al pleistocene medio-superiore, prima dell’impostazione dell’attuale corso d’acqua a nord del rilievo: questo antico collettore subiva nel tempo una progressiva migrazione verso sud (forno, 1980; forno, 1982; compagnoni & forno, 1992). le testimonianze conservate nei versanti occidentale e nordoccidentale, sensibilmente deformate e terrazzate, sono invece da collegare ad antichi percorsi dei fiumi dora riparia e stura di lanzo (b in fig. 1), riferibili anch’essi complessivamente al pleistocene medio-superiore, caratterizzati invece da una migrazione verso nw (boano et al., 2004; forno & lucchesi, 2005). le ipotesi circa la deformazione recente della struttura collinare sono in accordo con i dati desunti dai rilievi geodetici di precisione relativi al primo sessantennio del 1900, che indicano un sollevamento con valori fino a 3,5 mm/anno (arca & beretta, 1984): nel dettaglio il sollevamento risulta sensibilmente asimmetrico, con tassi maggiori per il versante settentrionale, in prossimità dei thrusts sepolti che delimitano il rilievo, e invece più modesti per quello meridionale, in continuità con l’altopiano di poirino. 2. assetto dell’attuale reticolato idrografico del t. banna nel versante meridionale della collina di torino e nell’altopiano di poirino si sviluppa l’attuale reticolato idrografico del t. banna, caratterizzato da un corso d’acqua principale con drenaggio verso w e da due opposti sistemi di affluenti drenanti mediamente verso s e ssw, per gli affluenti di destra, e verso nnw, per quelli di sinistra (fig. 2). i rilevamenti nell’ambito del progetto carg fig. 1sul versante meridionale della collina di torino e nell’altopiano di poirino sono conservate le tracce di antichi andamenti del paleopo (a); sul versante settentrionale sono invece conservate le testimonianze di antichi andamenti dei fiumi dora riparia e stura di lanzo (b). the relics of ancient trends of the paleopo (a) are preserved in the southern slope of the torino hill; the relics of ancient trends of the dora riparia and the stura di lanzo rivers (b) are preserved in the northern slope. fig. 2 il reticolato del t. banna è costituito da un’asta principale drenante verso w (a) e da due opposti sistemi di affluenti drenanti verso ssw, quelli di destra (b), e verso nnw, quelli di sinistra (c); asse dell’anticlinale della collina di torino (d); asse della sinclinale dell’altopiano di poirino (e). le frecce indicano il progressivo tilting dell’area. the hydrographic network of the banna stream is formed by a main watercourse draining toward w (a) and by two opposite tributaries draining toward ssw (b) and nnw (c), respectively; anticline axis of the torino hill (d); syncline axis of the poirino plateau (e). the arrows show the progressive tilting. fig. 3 sono osservabili relitti di valli con drenaggio verso e riferibili al paleopo, relitti con drenaggio verso se riferibili agli affluenti del paleopo, l’attuale t. banna con drenaggio verso w e gli attuali affluenti con drenaggio verso s o ssw. valleys of the paleopo draining toward e, valleys of the tributaries of paleopo draining toward se, t. banna draining toward w and present tributaries draining toward s or ssw are observed. 219riorganizzazione del reticolato idrografico ... hanno consentito di ricostruire con estremo dettaglio la successione stratigrafica del settore attualmente drenato dall’asta principale e dagli affluenti di destra e di riconoscere in queste aree relitti di valli fluviali caratterizzate da andamenti diversi rispetto alle incisioni attuali (fig. 3): come si vedrà più dettagliatamente in seguito questi relitti sono indicativi di antiche direttrici di drenaggio rispettivamente verso e (paleopo) e verso se (affluenti del paleopo), che contrastano con il deflusso attuale verso w dell’asta principale e verso ssw del sistema affluente. dal punto di vista altimetrico i relitti con diverso andamento sono conservati a quota diversa che rispecchia la loro differente età di impostazione, suggerita anche dal grado di alterazione non confrontabile dei depositi ad essi associati (cfr. figg. 6 e 8): le tracce del paleopo sono distribuite sulla sommità delle dorsali (1 in fig. 4) a costituire un’antica pianura alluvionale, ora profondamente dissecata; le tracce degli affluenti del paleopo sono conservate ad una quota intermedia a costituire valli sospese (2 in fig. 4) rispetto alle incisioni attuali, che appaiono invece notevolmente più profonde (3 in fig 4). i relitti idrografici più antichi (1 in fig. 4), già noti in letteratura, sono testimoniati dalla presenza in corrispondenza alla sommità delle attuali dorsali di depressioni allungate, arcuate in pianta, con raggio di curvatura chilometrico e varia orientazione, prevalentemente abbandonate (forno, 1982; compagnoni & forno, 1992). queste depressioni sono caratterizzate da ampiezza notevole, di alcune centinaia di metri, profondità tra alcuni metri e alcune decine di metri e risultano parzialmente colmate da corpi lenticolari relativamente estesi costituiti da sedimenti fluviali ghiaiosi e siltosi (fig. 5): i depositi ghiaiosi, con stratificazione incrociata concava, affiorano localmente alla base dei corpi fluviali; al di sopra si osservano più continui depositi siltosi, con fig. 4 le evidenze dell’antico collettore a meandri sono conservate sulle sommità delle dorsali (1); le tracce dei corsi d’acqua affluenti del collettore a meandri (2) costituiscono valli sospese rispetto alle incisioni attuali (3). the relics of meander collector ancient trends are preserved on the hilly ridges (1); the relics of meander watercourse tributaries (2) are suspended valleys on the present valleys (3). fig. 5 depositi siltosi e ghiaiosi connessi con il paleopo drenante verso e (pleistocene medio) (1); depositi fluviali sabbioso-ghiaiosi connessi con gli affluenti del paleopo (a) drenanti verso se (pleistocene superiore) (2); depositi eterogenei legati agli attuali corsi d’acqua (b) drenanti verso s e ssw (olocene) (3). silt and gravel sediments of the paleopo draining toward e (middle pleistocene) (1); sand-gravel sediments of the tributaries of the paleopo (a) draining toward se (upper pleistocene) (2); heterogeneous sediments of the present watercourses ( ) draining toward s and ssw (3)(holocene). fig. 6 i depositi fluviali ghiaiosi (b) e siltosi (c) connessi con il paleopo riferibili al pleistocene medio colmano ampie depressioni modellate nella successione marina terziaria (a). fluvial gravel (b) and silt (c) sediments of the paleopo, referred to middle pleistocene, fill wide depressions modelled in the cenozoic marine sediments (a). 220 spessore di alcuni metri, privi di stratificazione. la notevole pedogenesi dei sedimenti fluviali, evidenziata dal colore bruno-rossastro e dalla presenza di clasti molto alterati, suggerisce il riferimento al pleistocene medio (arduino et al., 1984) (fig. 6): in accordo con questa attribuzione cronologica è la presenza di una copertura di loess eolico di età pleistocenica superiore. mentre l’espressione morfologica di queste depressioni risulta spesso molto attenuata dalla presenza dei corpi fluviali e dell’ulteriore copertura di sedimenti eolici e\o colluviali, la distribuzione dei depositi fluviali descritti, esclusivamente associati alle depressioni relitte, risulta invece estremamente significativa. circa la genesi di questi elementi morfologici un insieme di considerazione permette di escludere che siano forme “attuali”da collegare all’attuale reticolato idrografico. le osservazioni più significative a questo proposito sono, oltre alla copertura di loess eolico, la distribuzione delle depressioni allungate, conservate in modo discontinuo sulla sommità delle dorsali collinari, l’assenza di un reticolato idrografico superficiale, le dimensioni rilevanti, con raggio di curvatura chilometrico, l’andamento variabile in pianta con prevalenza dell’orientazione e-w, circa ortogonale ai tracciati del reticolato idrografico attuale. l’insieme di questi elementi suggerisce invece che le forme descritte corrispondano ai relitti di antiche ampie valli fluviali, a costituire un’antica pianura alluvionale, ora profondamente dissecata (1 in fig. 5). la distribuzione dei depositi fluviali, che come si è detto colmano parzialmente depressioni con andamento ad anello sviluppate attorno a rilievi modellati nel substrato, indicano in particolare il legame con un corso d’acqua a meandri debolmente incastrati con raggio di curvatura chilometrico: la direzione prevalente delle fasce meandriche è in accordo con una direzione media di flusso circa e-w; la presenza di più fasce meandriche suggerisce che questo corso d’acqua fosse interessato da una progressiva migrazione verso sud traslando dall’attuale versante meridionale della collina di torino verso l’altopiano di poirino. la litologia dei clasti dei sedimenti fluviali ghiaiosi suggerisce che si trattasse di un percorso del “paleopo”, sviluppato a sud della collina di torino (fig. 3), drenante parte del settore alpino occidentale (compagnoni & forno, 1992). i relitti idrografici successivi (2 in fig. 4), riconosciuti invece in occasione dei recenti rilevamenti, corrispondono a evidenti segmenti di valli con andamento per lo più rettilineo in pianta e direzione di drenaggio in media verso se, anch’esse prevalentemente abbandonate (fig. 7) : sono sviluppati entro i solchi vallivi attuali, a quota sensibilmente inferiore rispetto ai relitti precedenti. questi relitti, con larghezza fino al centinaio di metri e incisione di alcune decine di metri, sono anch’essi parzialmente colmati da corpi lenticolari allungati costituiti da sedimenti fluviali sabbioso-ghiaiosi, con una più o meno evidente stratificazione incrociata concava. un insieme di elementi permette di escludere, anche in questo caso, che siano forme “attuali”: appaiono variamente sospesi e mostrano andamenti differenti in pianta rispetto ai tracciati attuali, dai quali risultano ripetutamente troncate; la modesta pedogenesi dei sedimenti fluviali, evidenziata dal colore bruno e dalla presenza di clasti poco alterati, suggerisce il riferimento al pleistocene superiore (arduino et al., 1984) (fig. 8). l’insieme di queste evidenze consente di ipotizzarne il riferimento a precedenti corsi d’acqua: l’andamento verso se suggerisce in particolare di riferirli ad affluenti del paleopo, impostati contemporaneamente alla progressiva migrazione verso sud di questo collettore (2 in fig. 5) (carraro et al., 2005). i tratti idrografici attuali, corrispondenti all’asta principale del t. banna drenante verso w e ai corsi d’acqua affluenti di destra con drenaggio verso s e ssw (3 in fig 4), modellano infine le incisioni più accentuate, con larghezza in genere di alcune decine di metri e profondità fino ad un centinaio di metri. come si vedrà meglio in seguito solo questi ultimi tratti mostrano andamento congruente con l’attuale inclinazione dell’area, in media verso sw (fig. 3). agli attuali corsi d’acqua impostati nei fondovalle sono infine da collegare i depositi fluviali recenti (3 in fig. 5), caratterizzati da natura molto eterogenea. fig. 8 depositi fluviali sabbioso-ghiaioso connessi con gli affluenti drenanti verso se riferibili al pleistocene superiore. fluvial sand-gravel sediments of tributaries draining toward se related to the upper pleistocene. fig. 7 ampia valle di un precedente percorso del r. ambuschetto drenante verso se, priva di reticolato idrografico superficiale. wide valley of r. ambuschetto ancient se trend, without superficial network . m.g. forno & p. boano 221 i diversi andamenti idrografici presi in considerazione sono indicativi di una diversa configurazione della superficie topografica indotta dalla deformazione recente: le tracce del paleopo drenante verso e, conservate come depressioni sulle dorsali, sono connesse con una pianura a meandri caratterizzata da una debolissima inclinazione verso e; la progressiva migrazione del paleopo verso s e l’impostazione degli affluenti, conservati come valli sospese drenanti verso se, indicano che si realizzava progressivamente una inclinazione verso s connessa con la deformazione differenziale dell’anticlinale (indicata dalla freccia nera in fig. 2). lo sviluppo del t. banna drenante verso w e degli attuali affluenti drenanti verso s e ssw indica che la superficie assumeva l’attuale inclinazione, rispettivamente verso w nel settore di altopiano e verso ssw nel settore collinare, connessa con un tilting del margine orientale (indicata dalla freccia in fig. 2) (forno, 1982). 3. fenomeni di riorganizzazione del reticolato idrografico i fenomeni di adattamento del reticolato idrografico alla progressiva realizzazione dell’inclinazione attuale verso sw dell’area sono avvenuti con modalità differenti, a seconda dell’entità dell’approfondimento dei corsi d’acqua nei diversi settori dell’area. nel settore meno deformato, in corrispondenza all’asse della sinclinale, i relitti del paleopo risultavano incisi di pochi metri entro alla pianura alluvionale: la scarsa incisione ha fatto sì che il t. banna, impostatosi a seguito della diversione dell’antico collettore, abbia potuto migrare lateralmente per adattarsi al mutare della superficie topografica, cancellando le tracce del precedente corso d’acqua. la variazione di pendenza che si può ipotizzare essersi realizzata tra quella originaria, molto debole verso e, e quella attuale conseguente al tilting, debolissima verso w, è stata modesta: in questo caso ad una minima variazione di pendenza indotta dalla deformazione è corrisposta una radicale modifica nell’andamento del reticolato idrografico, con inversione del drenaggio, che ha quindi enfatizzato la variazione morfologica. spostandoci verso n nei settori mediamente deformati lungo i fianchi dell’anticlinale il paleopo e la rete affluente erano incisi fino ad alcune decine di metri entro alla pianura alluvionale: in questo caso i corsi d’acqua impostatisi a seguito del tilting verso s, pur adattandosi alla variazione nell’andamento della superficie topografica, conservano testimonianza degli antichi andamenti. sono osservabili in particolare i relitti del collettore principale e dei suoi affluenti: si può ipotizzare che contemporaneamente alla migrazione verso s fig. 10 variazioni nell’andamento in pianta del rivo dei molini: le valli abbandonate successivamente (a1, a2, a3 e a4) sono delimitate da scarpate con altezza progressivamente decrescente rispetto alla valle attuale. legenda come in fig.5. trend variations of rivo dei molini stream: the abandoned valleys (a1, a2, a3 and a4) are separated by decreasing scarps from the present valley. legend as in fig. 5. fig. 9 variazioni negli andamenti in pianta del rio ambuschetto (a1, a2, a3, a4 e a5) progressivamente più prossimi alle direttrici attuali. legenda come in fig. 5. trend variations of ambuschetto stream (a1, a2, a3, a4 and a5) as they progressively reach the present trend. legend as in fig. 5. riorganizzazione del reticolato idrografico ... 222 del paleopo, drenante verso e, nei settori progressivamente abbandonati dal collettore principale, si siano impostati i corsi d’acqua drenanti verso se, ancora affluenti del paleopo, ora conservati come ampie valli (fig. 7) sospese rispetto agli attuali fondovalle. nel dettaglio la maggior parte dei segmenti modellati dall’antico reticolato, principale e affluente, risulta abbandonata e conservata come valli relitte, in quanto non congruente con l’attuale inclinazione dei versanti; solo localmente alcuni segmenti, orientati invece casualmente secondo la direzione di pendenza attuale, appaiono riutilizzati dagli attuali corsi d’acqua, affluenti del t. banna, che come si è detto drenano prevalentemente verso ssw (fig. 5). le valli relitte non riutilizzate, prive di un reticolato idrografico superficiale, appaiono troncate a monte dall’incisione degli attuali corsi d’acqua. le stesse valli, anche se prive della testata, raccolgono ovviamente le acque ruscellanti e appaiono comunque reincise nel tratto inferiore: nel fondovalle si sviluppano talvolta emergenze idriche, caratterizzate da portate notevoli, sviluppate al limite tra il settore superiore, abbandonato, e quello inferiore, reinciso. analizzando come è avvenuto il passaggio tra gli andamenti verso se del reticolato affluente del paleopo a quelli attuali verso ssw si osserva un ripetuto adattamento dei corsi d’acqua alla progressiva variazione nell’inclinazione della superficie topografica indotta dalla deformazione (fig. 9). in questi settori ad una variazione di inclinazione di pochi gradi è corrisposta una evidente variazione dei tracciati fluviali. l’insieme delle valli abbandonate conservate non indica variazioni casuali di un singolo canale ma una riorganizzazione sistematica che riguarda la maggior parte dei corsi d’acqua: le valli abbandonate progressivamente più recenti sono distribuite a quota via via inferiore e delimitate da scarpate con altezza progressivamente decrescente rispetto alla valle attuale (fig. 10). localmente le variazioni nell’andamento del reticolato idrografico creano rilievi isolati come quello su cui è edificata la parte più elevata del centro storico di chieri, che comprende la chiesa di san giorgio, interpretabile come lembo relitto di un terrazzo fluviale (fig. 11): inizialmente si avevano due corsi d’acqua circa paralleli drenanti verso se, interrotti dall’andamento verso s dei tratti attuali del reticolato idrografico (fig. 12). nelle aree più deformate prossime all’asse della struttura anticlinale il collettore principale e il reticolato affluente erano notevolmente più incisi entro alla pianura alluvionale: la marcata incisione ha reso impossibili le variazioni nell’andamento in pianta da parte degli attuali corsi d’acqua e di conseguenza non è fig. 11 lembo di terrazzo di san giorgio connesso con l’incisione di un terrazzo fluviale del rio dei ceppi (a) da parte dell’attuale reticolato idrografico (b). san giorgio relic connected with the incision of rio dei ceppi fluvial terrace (a) by the present hydrographic network (b). fig. 12 lembo di terrazzo fluviale su cui è edificato il centro storico di chieri, modellato da un antico andamento verso se del rio dei ceppi, interrotto dall’andamento attuale dei corsi d’acqua. the fluvial terraced surface on which the historical centre of chieri is built modelled by an ancient rio dei ceppi trend draining toward se, cut by the present network . avvenuta una evidente riorganizzazione del reticolato idrografico. le tracce del paleopo e dei suoi affluenti corrispondono a valli con profilo longitudinale caratterizzato da inclinazione variabile per la presenza di un tratto di testata poco inclinato: questi relitti, variamente troncati o approfonditi dal reticolato idrografico attuale, sono in genere riconoscibili per la presenza di selle in contropendenza nello spartiacque collinare (fig. 13). in questi settori i corsi d’acqua, vincolati all’andamento precedente, non subiscono variazioni di andamento in pianta ma rispondono con un approfondimento del tratto inferiore, per adattarsi al nuovo gradiente indotto dalla deformazione. m.g. forno & p. boano 4. conclusioni gli esempi segnalati confermano che il reticolato idrografico è un indicatore molto attendibile delle variazioni nell’inclinazione di un determinato settore; di conseguenza l’andamento dei corsi d’acqua può diventare un marker estremamente significativo delle variazioni nell’assetto della superficie topografica indotte dalla deformazione recente. gli stessi esempi confermano che il reticolato è un marker molto sensibile in quanto registra anche variazioni minime. una variazione nell’andamento dei tracciati idrografici è tanto più realizzabile quanto meno i corsi d’acqua sono approfonditi all’interno della pianura o del fondovalle alluvionale. in particolare nei casi di scarso approfondimento può verificarsi una totale riorganizzazione del drenaggio che porta all’obliterazione dei tracciati precedenti. nei casi di approfondimento intermedio i tracciati precedenti verranno invece abbandonati ma rimarranno conservati come valli relitte. nei casi infine in cui l’approfondimento dei corsi d’acqua è notevole il tracciato antico è vincolante e può avvenire solo una variazione nell’entità dell’approfondimento. bibliografia arca s. & beretta g. (1985) prima sintesi geodeticageologica sui movimenti verticali del suolo nell’italia settentrionale (1897-1957). boll. geod. sc. aff., 2, 125-156. arduino e., barberis e., carraro f. & forno m. g. (1984) estimating relative ages from ironoxide/total-iron ratios of soils in the western po valley, italy. geoderma, 33, 39-52, amsterdam. boano p., forno m. g. & lucchesi s. (2004) pleistocene deformation of the collina di torino inferred from the modelling of their fluvial succession. il quaternario, it. journ. quatern. sc.,17 (2/1), 145-150. bortolami g.c., crema g. c., malaroda r., petrucci f., sacchi r., sturani c., tagliavini s. & venzo s. (1969) foglio 56 “torino” della carta geologica d’italia alla scala 1:1000.000. iia ed., serv. geol. it., roma. carraro f., forno m. g., giardino m. & paro l. (2005) field trip guide.14th meeting of the association of european geological societies, september 23th 2005, torino hill. il quaternario, it. journ. quat. sc., 18(2), 3-55. compagnoni r. & forno m. g. (1992) significato geologico di depositi fluviali ghiaiosi pleistocenici medi nella collina di torino. il quaternario, it. journ. quatern. sc., 5, 105-122. festa a., piana f., dela pierre f., malusà m., mosca p. & polino r. (2005) oligocene-neocene kinematic constraints in the retroforelan basin of the northwestern alps. rend. soc. geol. it, 2005, nuova serie. forno m. g. (1980) evidenza di un drenaggio abbandonato nel settore settentrionale dell’altopiano di poirino (prov. di torino). geogr. fis. dinam. quat., 3, 61-65. forno m. g. (1982) studio geologico dell’altopiano di poirino. geogr. fis. din. quat., 5, 129-162. forno m. g. & lucchesi s. (2005) la successione fluviale terrazzata pleistocenica dei versanti occidentale e nordoccidentale della collina di torino. il quaternario, it. journ. quatern. sc., 18(2), 123134. piana f. & polino r. (1994) la zona transpressiva di rio freddo e l’evoluzione convergente della collina di torino e del monferrato durante il terziario. atti tic. sc. terra, ser. spec., 1, 167180. 223 ms. ricevuto il 26 luglio 2006 testo definitivo ricevuto il 3 ottobre 2006 ms. received: july 26, 2006 final text received:october 3, 2006 fig. 13 la valle di rivalba, riconoscibile per la presenza di una evidente sella in contropendenza, appare decapitata e caratterizzata nella parte superiore da inclinazione modesta. the rivalba valley is cut and shows in the upper part a less inclined profile. riorganizzazione del reticolato idrografico ... imp.03saroli nuovi dati paleosismologici dal settore orientale del bacino del fucino (italia centrale) michele saroli1, marco moro2, hermann borghesi3, daria dell’acqua4, fabrizio galadini5, paolo galli6 1 dipartimento di meccanica, strutture, ambiente e territorio, università di cassino, e-mail: michele.saroli@unicas.it 2 istituto nazionale di geofisica e vulcanologia 3 cooperativa limes, avezzano 4 coll. esterno istituto nazionale di geofisica e vulcanologia, roma 5 istituto nazionale di geofisica e vulcanologia, milano 6 dipartimento della protezione civile, roma. riassunto: m. saroli et al., nuovi dati paleosismologici dal settore orientale del bacino del fucino (italia centrale). (it issn 03943356, 2008). l’analisi di depositi del pleistocene superiore-olocene in due cave a ridosso della faglia san benedetto dei marsi-gioia dei marsi (bacino del fucino, appennino centrale) ha consentito di ottenere informazioni paleosismologiche che integrano quanto già pubblicato in materia alla fine del secolo scorso. in entrambi gli affioramenti sono stati osservati sedimenti colluviali, alluvionali e lacustri deposti successivamente al tardiglaciale (14-15 ka bp). vincoli cronologici per le successioni individuate vengono da una datazione radiocarbonio (1466-1372 b.c., età calibrata a 2 sigma), da numerose determinazioni archeologiche su materiali ceramici attribuiti all’eneolitico e all’età del bronzo e dal rinvenimento di una fossa di cottura inquadrabile nello stesso ambito cronologico. le unità stratigrafiche identificate sono in contatto per faglia con il substrato carbonatico. il trascinamento dei sedimenti lungo i piani di faglia principali e le dislocazioni osservate lungo piani di taglio secondari definiscono l’attività olocenica di questo settore della faglia san benedetto dei marsi-gioia dei marsi. l’analisi del primo fronte di scavo ha fornito l’evidenza di tre eventi di dislocazione di cui il più recente avvenuto successivamente alla deposizione dell’unità colluviale con frammenti ceramici preistorici. l’analisi del secondo fronte di scavo ha ugualmente permesso di identificare tre eventi di dislocazione di cui il più recente interessa l’unità nella quale è stata scavata la fossa di cottura. due dei tre eventi identificati potrebbero corrispondere a due dei tre più antichi eventi dell’olocene identificati nei precedenti lavori e avvenuti all’incirca tra 5 e 10 ka bp. l’evento più recente potrebbe invece essere associato a quello già riferito all’intervallo 1500-1300 a.c., e/o ai due eventi successivi, vale a dire quello riferibile alla tarda antichità-alto medioevo (426–782 d.c., età 14c cal. in galadini e galli, 1999) e quello avvenuto nel 1915. infine, l’entità del rigetto verticale ha permesso di valutare un rateo minimo di movimento dell’ordine di 0.14-0.35 mm/a. abstract: m. saroli et al., new paleoseismological data from the fucino basin (central italy). (it issn 0394-3356, 2008). the fucino plain represents the area with the best italian paleoseismological record. this is mainly due to the fact that, differently from other apennine cases, late pleistocene-holocene faults border and affect a lacustrine basin which has been persistent throughout the late pleistocene-holocene until the 19th century. thanks to this almost continuous stratigraphical record, galadini and galli (1999) described the complete displacement history of the fucino fault, which finally activated in 1915, causing a mw=7.0 earthquake. these authors also identified six previous holocene events (with recurrence intervals of 1,400-2,600 years), and three others occurred in the upper late pleistocene. on the whole, the fucino paleoseismological record consists of ten events (including the 1915 one) in the past 32,500 years. human works, especially those related to the excavation of foundations, extraction from quarries and cleaning of the drainage network, gave the opportunity to study new outcrops of paleoseismological interest. the recent analysis of two quarry walls located along the western flank of the basin (i.e. where the surficial expression of one of the main faults is located) has provided data which corroborate the previous studies. alluvial gravels deposited along the shoreline of the lake and colluvial deposits outcrop in both quarries. unit 1 of quarry-wall fs1 is made of matrix supported gravel, with pottery shards attributed to 3000-1500 b.c., whereas the radiocarbon dating of the organic matrix gave 1466-1372 cal b.c. (2 sigma). unit 2, whose origin is uncertain (alluvial deposits accumulated and reworked along the lacustrine shoreline?), is made of gravel included in silty-sandy matrix. apart from sub-unit 3b, unit 3 is prevalently made of gravel and coarse sand due to alluvial deposition close to the lacustrine shoreline. based on the available literature (giraudi, 1988, 1999a), it deposited at the end of the late pleistocene. sub-unit 3b is particularly significant for the paleoseismological analysis, since it has been interpreted as a colluvial wedge originated from the erosion of a coseismic fault scarp. unit 4, made of clast-supported gravel, probably represents a shoreline deposit. the relationship between the fault planes and the described succession suggests that at least three events of displacement occurred after the deposition of sub-unit 3d, the oldest one being related to the colluvial wedge (unit 3b) and the youngest being represented by the displacement of the entire succession (including unit 1 containing the pottery shards). the other quarry wall (fs2) shows archaeological remains (inside unit 2) below the present soil (unit 1). these remains are basically represented by a pit-fire containing fragments of pottery shards attributed to the eneolithic and the bronze age (3000-1500 b.c.). the characteristics of the unit 3 gravel indicate deposition along the shoreline, while unit 4 (gravel in sandy matrix) has been interpreted as a colluvial wedge deposited from a coseismic scarp. finally, unit 5 represents the result of the re-organisation of alluvial gravel by the lacustrine shoreline water. from a chronological point of view, this unit can be compared to unit 3 of fs1, i.e. it deposited at the end of the late pleistocene. the analysis of the relationship between the fault planes and the stratigraphic units defines at least three displacement events, the intermediate being represented by the deposition of the colluvial wedge and the ultimate(s) by the displacement of unit 3 within which the pit-fire has been excavated. on the whole, the oldest and the intermediate events may represent two of the three oldest holocene events identified by galadini and galli (1999), which occurred between 5 and 10 ka bp. indeed, the oldest displaced units, based on the available literature (giraudi, 1988; 1999a), deposited after 14-15 ka bp. the most recent event(s), besides the 1915 rupture, may be associated to the event dated at 1500-1300 b.c. by galadini and galli (1999) and/or, considering the displacement affecting unit 1 (fs1), to the penultimate holocene event dated at the late antiquity/early middle ages (426 – 782 a.d., cal. age 14c in galadini and galli, 1999). finally, the amount of displacement and the chronological constraints permit us to define vertical displacement rates not exceeding 0.35 mm/yr for the main fault of fs1 and 0.14 mm/yr for the main fault of fs2. parole chiave: paleosismologia, faglia attiva, sismotettonica, piana del fucino, italia centrale. keywords: paleoseismology, active fault, seismotectonics, fucino plain, central italy. il quaternario italian journal of quaternary sciences 21(1b), 2008 383-394 384 m. saroli et al. 1. introduzione l’appennino abruzzese è stato interessato da numerosi terremoti distruttivi. tra questi, il terremoto del 13 gennaio 1915 (maw=6.99, gruppo di lavoro cpti, 2004), responsabile di più di 30.000 vittime, è stato causato dall’attivazione di faglie che interessano il bacino del fucino (es. galadini and galli, 1999), area indagata nel presente studio. le numerose analisi paleosismologiche condotte in questa zona hanno permesso di caratterizzare il comportamento sismogenetico dell’area con notevole dettaglio (michetti et al., 1996; galadini et al., 1997a e 1997b; galadini e galli, 1999). l’analisi paleosismologica recentemente effettuata su nuovi affioramenti di unità del pleistocene superiore – olocene all’interno di due cave ha consentito di arricchire ulteriormente il già dettagliato quadro degli eventi paleosismici occorsi nell’area del fucino. il lavoro ha riguardato la fascia pedemontana dei rilievi che bordano il fianco orientale del bacino, lungo la faglia gioia dei marsi–san benedetto dei marsi, uno dei segmenti che costituiscono l’espressione superficiale della sorgente del terremoto del 1915. dopo una raccolta di dati bibliografici (paleosismologici e archeologici) utili alla definizione delle attuali conoscenze dell’area in studio, si è proceduto all’analisi stratigrafico-strutturale di fronti di scavo (fs1 e fs2) delle due cave citate. i vincoli cronologici sono stati ottenuti grazie a una datazione radiocarbonio di materiale organico e determinazioni archeologiche di frammenti ceramici attribuiti al neolitico, eneolitico e all’età del bronzo. nei capitoli seguenti sono discusse le varie implicazioni derivate dall’interpretazione dei dati acquisiti, soprattutto per quanto concerne l’inquadramento cronologico dei singoli eventi di dislocazione individuati. 2. inquadramento geologico e geomorfologico del bacino del fucino l’area di studio è ubicata nel comune di pescina, frazione venere dei marsi, nel settore orientale della piana del fucino, in località le coste (figg. 1 e 2). la piana del fucino (circa 660 m s.l.m.) rappresenta l’alveo del lago storico, prosciugato nel xix secolo, ospitato in un bacino tettonico di tipo semi-graben (es. galadini e messina, 1994), controllato da sistemi di faglie dirette prevalentemente con andamento no-se e ne-so. il bacino è delimitato ad e e ad o da dorsali montuose orientate no-se con quote massime che raggiungono i 2300 m s.l.m. (fig. 1). i versanti sono scolpiti prevalentemente su formazioni carbonatiche meso-cenozoiche e depositi plio-quaternari di origine colluviale, alluvionale e lacustre. questi depositi sono discordanti sul substrato marino e si rinvengono in affioramenti discontinui (galadini e messina, 1994; bosi et al., 1996). la stratigrafia dei depositi degli ultimi 30.000 anni e le forme ad essi legate sono riferibili alla dinamica del livello lacustre, con il susseguirsi di fasi di alto e basso stazionamento. la complessa successione di forme e depositi è ampiamente descritta in giraudi (1988), cui si rimanda per l’approfondimento. per quanto riguarda l’area di venere dei marsi, zona oggetto del presente studio, la stratigrafia degli ultimi 20.000 anni è definita da giraudi (1995). essa è rappresentata da una successione di depositi di versante, presenti alla base dei rilievi, organizzati in coni o falde e poggianti sia su depositi lacustri risalenti all’ultimo massimo glaciale sia su terrazzi lacustri più recenti. nell’insieme, l’autore citato definisce cinque formazioni detritiche di età, dalla più antica, pari a 18 – 14 ka (“1a formazione”), 14 – 5.5 ka (“2a formazione”), <5 ka (“3a formazione”), �2.7 ka (“4a formazione”), e più recente del i sec. d.c., per via del ritrovamento, al suo interno, di frammenti di ceramica di età romana imperiale (“5a formazione”). 3. evoluzione cinematica e caratteristiche sismotettoniche dell’area fucense l’attuale assetto strutturale del bacino del fucino è il risultato di una complessa storia tettonica legata all’attività, a partire dal pliocene, di due sistemi di faglie normali, uno con direzione ne-sw, l’altro orientato nw-se. tali sistemi hanno avuto, in momenti diversi, il ruolo di faglie primarie nell’evoluzione strutturale del bacino. l’assetto di questa grande depressione intermontana è pertanto assimilabile a quello derivante dalla sovrapposizione di due semi-graben con diversa orientazione (es. galadini e messina, 1994). al primo dei sistemi sopra citati appartiene la faglia dei tre monti (tmfz in fig. 1), lunga all’incirca 7 km, che rappresenta il segmento più occidentale del più importante sistema di faglie avezzano–bussi. questa faglia, attiva dal pliocene, è responsabile della nucleazione del bacino. ad essa è imputabile, infatti, la fase più antica di strutturazione, consistita nella formazione di un semi-graben con asse ne-sw (es. galadini e messina, 1994). a partire dal pliocene (superiore?) il ruolo primario nell’evoluzione del bacino è stato ricoperto dalle faglie con direzione no-se. questo sistema, lungo il bordo orientale della depressione, è stato responsabile dell’evoluzione più recente del bacino, consistita nella strutturazione di un semi-graben con asse no-se, sovrapposto al precedente. il sistema è costituito dalle faglie normali s.benedetto dei marsi-gioia dei marsi (sbgf in fig. 1), della s.s. marsicana (smf in fig. 1) e monte velino-m.ti della magnola (vmf in fig. 1), disposte in relazione geometrica en-echelon (step destro ) . probabilmente, i vari segmenti rappresentano le espressioni superficiali di un'unica struttura sismogenetica con direzione no-se, lunga più di 30 km, che interessa il versante nordorientale dell’intera depressione (galadini et al., 1998). in alternativa a questa interpretazione, la faglia monte velino-m.ti della magnola è stata considerata come l’espressione di una sorgente sismogenetica distinta da quella la cui emergenza è rappresentata dalle prime due faglie citate (boncio et al., 2004). numerosi lavori paleosismologici hanno individuato le tracce geologiche di eventi sismici (evidenze di ripetute fogliazioni superficiali) che hanno interessato il bacino del fucino negli ultimi 30 ka. per quel che riguarda gli eventi di fagliazione tardo pleistocenici, il più antico documentato ha un’età compresa tra 32 ka e 20 ka b.p. ed è stato riconosciuto in un affioramento nei pressi di casali d’aschi, lungo la faglia san benedetto dei marsi–gioia dei marsi (galadini et al., 1997a; galadini e galli, 1999). un’altra dislocazione cosismica, definita tramite l’analisi di uno scavo realizzato attraverso la faglia della s.s. marsicana e docu385nuovi dati paleosismologici ... mentata in numerosi lavori (giraudi, 1988; galadini et al., 1995; galadini et al., 1997a; galadini e galli, 1999), è riferibile a ca. 20 ka b.p. (19.100±650 anni b.p., età 14c). il più recente evento di dislocazione pre-olocenico, registrato sulla faglia di trasacco, è datato 15.66614.397 a.c. (età 14c calibrata), con entità del rigetto fig. 1 schema delle faglie ad attività quaternaria dell’area compresa tra la valle del fiume sangro e campo felice: of, faglia di ovindoli; vmf, faglia m.velino-m.ti della magnola; tmfz, zona di faglia dei tre monti; acf, faglia avezzano-celano; smf, sistema di faglie della s.s. marsicana; pmgf, faglia stazione di pescina-madonna delle grazie; sbgf, faglie s.benedetto dei marsi-gioia dei marsi; tf, faglia di trasacco; lf, faglia di luco dei marsi; asff, sistema di faglie alto sangro-fucino. l’asterisco definisce l’area indagata. map of the quaternary faults in the area between the sangro river valley and the campo felice basin: of, ovindoli fault; vmf, mt.velino-magnola mts. fault; tmfz, tre monti fault zone; acf, avezzano-celano fault; smf, marsicana highway fault system; pmgf, pescina railway station-madonna delle grazie fault; sbgf, s.benedetto dei marsi-gioia dei marsi fault; tf, trasacco fault; lf, luco dei marsi fault; asff, alto sangro-fucino fault system. the asterisk indicates the investigated area. superiore ai 70 cm (galadini e galli, 1999). ad esso è attribuita la dislocazione della spianata di abrasione di avezzano, modellata 18-20 ka anni fa (giraudi, 1988). le indagini paleosismologiche hanno permesso di individuare 7 eventi di dislocazione avvenuti nel corso dell’olocene. i tre eventi più antichi, assai evidenti in alcuni scavi attraverso la faglia di trasacco, sono avvenuti tra due età limite: 10.729-10.053 a.c. e 5.979-5.576 a.c., definite con datazioni radiocarbonio (galadini et al., 1997a; galadini e galli, 1999). un quarto evento, documentato in tre scavi effettuati attraverso la faglia di trasacco, è datato a 3944–3618 anni a.c. (età 14c cal.; galadini et al., 1997a; galadini e galli, 1999). a un quinto evento di dislocazione viene attribuita l’età 1600–1400 anni a.c. (galadini et al., 1997a; galadini e galli, 1999). il penultimo evento olocenico risale alla tarda antichità o all’alto medioevo (426–782 d.c., età 14c cal. in galadini e galli, 1999; individuato anche nello studio paleosismologico di michetti et al., 1996) e viene tentativamente riferito al terremoto che nel 508 d.c. causò danni significativi al colosseo in roma (galadini e galli, 1996). il più recente evento sismico determinato dall’attivazione delle faglie oggetto di questo studio ha interessato il bacino del fucino il 13 gennaio 1915 (serva et al., 1986; michetti et al., 1996; galadini e galli, 1999), ha avuto una magnitudo pari a 7.0, è stato responsabile di ingenti danni in tutta l’area e ha causato danni anche a roma (molin et al., 1999). l’epicentro di questo terremoto è ubicato tra gioia dei marsi e ortucchio (working group cpti, 2004). grazie agli studi paleosismologici, alla ricostruzione del quadro strutturale compatibile col regime tettonico in atto e al confronto tra questo e la distribuzione del danno, si è giunti alla conclusione che il terremoto sia stato generato dalla rottura in profondità di una sorgente lunga oltre 30 km, la cui espressione superficiale è rappresentata dalle faglie di san benedetto dei marsigioia dei marsi, della s.s. marsicana e, presumibilmente, m. velino–m.ti della magnola (galadini et al., 1998). come osservato, movimenti verticali hanno anche interessato faglie secondarie, come quelle di trasacco e di luco dei marsi (galadini e galli, 1999). il tempo di ricorrenza di eventi di dislocazione cosismici in quest’area è tra i 1400 e i 2600 anni, dato affine a quelli disponibili per altre faglie attive appenniniche (galadini e galli, 2000). 4. analisi paleosismologiche le analisi paleosismologiche al margine orientale della piana del fucino (fig. 2) sono state condotte lungo i fronti di scavo fs1 e fs2 di due cave, in prossimità del contatto tettonico tra il substrato carbonatico e i depositi alluvionali-lacustri e colluviali tardo-quaternari. gli affioramenti, una volta puliti e resi il più possibile verticali, sono stati attrezzati con un reticolo a maglia regolare, che ha consentito di effettuare rilievi su carta millimetrata e di rappresentare alla scala 1:50, su una base fotografica vincolata dalla geometria del reticolo, le strutture e le unità stratigrafiche che caratterizzano le pareti oggetto dello studio. l’età dei paleoeventi è stata vincolata sulla base di una datazione 14c effettuata su un campione (cavs1) prelevato dal fronte di scavo fs1 e da determinazioni archeologiche su frammenti ceramici. l’analisi sul terreno ha consentito di definire le relazioni tra i vari piani di taglio individuati e le unità stratigrafiche al fine di definire la successione degli eventi di dislocazione. 4.1 fronte di scavo 1 (fs1) questa parete (l = 10 m; h = 8 m) ha direzione circa e-o, obliqua rispetto all’andamento generale del versante (orientato nno-sse). e’ ubicata a quota 690 m e si trova all’interno di una cava in sfruttamento, sita tra il km 12 e il km 13 della s.s. 83 (nel tratto tra venere dei marsi e gioia dei marsi), nel comune di pescina. il fronte di scavo (fig. 3) interessa una successione costituita prevalentemente da depositi alluvionali quaternari (fig. 4). la porzione superiore della parete è costituita da materiale di riporto, connesso alla coltivazione della cava, non rilevante ai fini del presente studio. 4.1.1 stratigrafia al tetto della successione sedimentaria, si trova la copertura colluviale olocenica (unità 1 in fig. 4); si tratta di depositi di spessore pari a circa 2 m, matrice sostenuti, composti da limi e limi sabbiosi scuri con ghiaie costituite da clasti da centimetrici a pluricentimetrici. all’interno di quest’unità sono stati rinvenuti frammenti ceramici di impasto, fluitati, riferibili genericamente all’eneolitico–età del bronzo (3000-1500 anni a.c.). sono composti da materiale argilloso, di colore aranciato esternamente e grigio scuro nelle parti interne, con inclusi di calcare e minerali femici. la presenza di spigoli vivi fa dedurre un trasporto piuttosto breve. in quest’unità è stato prelevato un campione di materiale organico, la cui età radiocarbonio prodotta dal laboratorio, 3135±30 bp, calibrata a 2 sigma ha fornito 14661372 a.c. (codice laboratorio: poz-16619). subito al di sotto del colluvio, l’unità 2 (fig. 4), con spessore di 50 cm, è costituita da ghiaie in matrice sabbioso-siltosa scura. non sono stati riscontrati elementi diagnostici per definirne l’ambiente deposizionale. l’unità 2 poggia in discordanza sull’unità sottostante, di seguito descritta. l’unità 3 (fig. 4) è stata suddivisa in 4 sottounità: si tratta di differenti facies appartenenti ad un contesto deposizionale di ambiente alluvionale prossimo alla sponda lacustre. l’unità 3a (fig. 4), con spessore di circa 40 cm, è costituita da ghiaie grossolane arrotondate in abbondante matrice sabbioso-siltosa di colore grigio chiaro; i clasti sono matricesostenuti. l’unità 3c, in contatto discordante sulla sottostante unità 3d (figg. 4 e 5), ha una geometria lentiforme con spessore decrescente dai 40 ai 20 cm in direzione della faglia principale (f1). i depositi sono costituiti da silt sabbioso e da due livelli centimetrici di sabbie fini. considerando l’originaria deposizione, alluvionale ma in prossimità della sponda lacustre, la granulometria suggerisce che essi rappresentino il risultato di rielaborazione dei sedimenti in ambiente di spiaggia. tale interpretazione sembra anche corroborata dalla tendenza alla rastremazione dell’unità verso est, per cui 386 m. saroli et al. 387 fig. 2 settore orientale del bacino del fucino: aerofotogramma dal volo italia ’88-’89 alla scala 1:70.000. sono evidenziate le strutture tettoniche principali. il riquadro indica l’area di studio, gli asterischi indicano i siti. aerial view (“volo italia” 1988-89; 1:70,000 scale) of the eastern fucino basin. the main tectonic features have been indicated. the square defines the investigated area while the asterisks indicate the investigated sites. fig. 3. cava con fronte di scavo 1 (fs1 nel testo): evidenziati i contatti tra substrato calcareo, il colluvio e le ghiaie lacustri. quarry wall fs1: the contacts between the different stratigraphic units have been indicated. nuovi dati paleosismologici ... 388 fig. 4. riproduzione grafica e fotomosaico del fronte di scavo 1. unità 1: copertura colluviale olocenica costituita da depositi di spessore pari a circa 2 m, matrice sostenuti, composti da limi e limi sabbiosi scuri con ghiaie. unità 2: ghiaie in matrice sabbiosolimosa scura. unità 3a: ghiaie grossolane arrotondate in abbondante matrice sabbioso-limosa grigio chiaro con spessore di circa 40 cm. unità 3b: ghiaie in matrice sabbiosa con spessore variabile dai 20 ai 50 cm (cuneo colluviale). unità 3c: limo sabbioso con spessore variabile 40 ai 20 cm. unità 3d: ghiaie centimetriche in matrice sabbioso-limosa debolmente cementate con spessore di 25 cm. unità 4: ghiaie con ciottoli arrotondati in matrice limoso-sabbiosa scarsamente cementate, clastosostenute e caotiche. quarry wall log and photomosaic of the quarry wall fs1. unit 1: holocene darkish colluvial silts and sandy silts with gravel. unit 2: gravel in sandy-silty darkish matrix. unit 3a: coarse rounded pebbles in abundant light gray sandy-silty matrix. unit 3b: gravel in sandy matrix (colluvial wedge). unit 3c: sandy silt. unit 3d: slightly cemented sandy-silty gravel. unit 4: slightly cemented rounded gravel with sandy-silty matrix, massive and clast-supported. m. saroli et al. è ipotizzabile che la sedimentazione sia legata ad una fase di stazionamento lacustre prossimo al sito indagato. in rapporto stratigrafico concordante con l’unità 3c al tetto e discordante con la 3d al letto, l’unità 3b (fig. 4) è composta di ghiaie in matrice sabbiosa. lo spessore del deposito aumenta in direzione della faglia principale (f1), in corrispondenza della quale raggiunge i 50 cm. le caratteristiche geometriche dei limiti stratigrafici del tetto e della base dell’unità 3b e l’aspetto massivo tipico della deposizione colluviale inducono ad ipotizzare che si tratti di un “cuneo colluviale”, ovvero di un deposito alimentato da una adiacente scarpata di faglia (es. mccalpin, 1996). al di sotto del colluvio citato si trova l’unità 3d (fig. 4), costituita di ghiaie centimetriche in matrice sabbioso-siltosa; le ghiaie presentano debole cementazione carbonatica riconducibile a processi di circolazione idrica secondaria. sono inoltre presenti evidenti tracce di ossidazione in aree di forma lenticolare in sezione, anch’esse riconducibili ai medesimi processi. l’unità ha uno spessore di circa 25 cm. l’unità 4 (fig. 4), affiorante per circa 1.5 m di altezza, è composta di ghiaie con ciottoli arrotondati (diametro da 1 a 30 cm) con scarsa matrice siltoso-sabbiosa; presenta limitata cementazione ed una struttura clasto-sostenuta e caotica. questi aspetti fanno ipotizzare che l’originario deposito alluvionale sia stato rielaborato nell’ambiente lacustre prossimo alla linea di riva. e’ evidente un aumento della granulometria verso l’alto stratigrafico. 4.1.2 tettonica la parete è interessata da due piani di taglio: f1 nella parte orientale dell’affioramento e f2 nel settore più occidentale (fig. 4). f1 interessa tutta la successione e la limita verso est, ponendola in contatto con il substrato carbonatico (figg. 4 e 6). le unità alluvionali e colluvial i appaiono intensamente deformate a ridosso di f1 e trascinate lungo il piano di faglia (fig. 6). f2 interessa le unità 2, 3 e 4 (fig. 4) per un’altezza di circa 1 m ed un rigetto piuttosto esiguo (10-20 cm). ipotizzando che la deposizione dell’unità 4 sia da riferirsi – per quota e in confronto ai livelli lacustri ricostruiti da giraudi (1999a) – al tardiglaciale e che essa sia correlabile con la piattaforma di abrasione lacustre che si trova al letto della faglia f1, l’entità della dislocazione che interessa tale unità potrebbe essere valutata nell’ordine dei 5 m. nella parete sono stati individuati almeno 3 eventi di dislocazione di età successiva alla deposizione dell’unità 3d. al più antico dei tre (e3) potrebbe essere riferibile la formazione del cuneo colluviale (unità 3b in fig. 4). come sopra 389 fig. 5. contatto tra l’unità 3c (sabbia) e l’unità 3d (ghiaie). stratigraphic contact between unit 3c (sand) and unit 3d (gravel). fig. 6. dettaglio della zona di faglia che pone a contatto il substrato carbonatico con le unità lacustri, alluvionali e colluviali. si noti l’intensa deformazione dei depositi trascinati verso l’alto dal movimento normale della faglia. view of the fault zone placing the carbonate substratum in contact with the lacustrine, alluvial and colluvial deposits. the intense deformation of the deposits along the fault zone is visible. nuovi dati paleosismologici ... accennato, le caratteristiche sedimentologiche dell’unità suggeriscono un’origine connessa all’erosione della adiacente scarpata di faglia formata a seguito del movimento della faglia f1. il secondo evento (e2), rappresentato dalla dislocazione legata alla faglia f2, è sicuramente posteriore alla deposizione dell’unità 3a e precedente alla deposizione dell’unità 1. la base dell’unità 2 è dislocata di 20 cm (fig. 4). l’assenza di dislocazione al tetto dell’unità 2 può essere imputata ad erosione successiva al movimento della faglia. per quanto concerne l’ultimo evento (o insieme di eventi) e1, ad esso è attribuibile la dislocazione dell’intera successione lungo il piano di faglia f1. tale dislocazione è sicuramente posteriore alla deposizione dell’unità colluviale 1, contenente materiale archeologico, come evidenziato dalla deformazione di questi depositi in prossimità del contatto con la faglia (fig. 6). in sintesi gli eventi di dislocazione che hanno interessato questa successione stratigrafica sono evidenziati, dal più antico: • e3: dalla deposizione del cuneo colluviale (unità 3b); • e2: dalla dislocazione dei depositi delle unità 2, 3 e 4; • e1: dalla fagliazione dell’intera successione sedimentaria, definita dall’intensa deformazione nei depositi alluvionali in prossimità della faglia (fig. 6) e dal trascinamento del deposito lacustre riferibile all’unità 3c lungo il piano di faglia. 4.2 fronte di scavo 2 (fs2) questa parete di scavo (l = 10 m; h = 3 m) è orientata circa e-o. si trova all’interno di una cava dismessa, a quota 690 m, anch’essa ubicata lungo la ss83 nel tratto tra venere e gioia dei marsi, circa 500 m a s del sito precedentemente descritto. anche in questo caso la successione sedimentaria è delimitata a e dal piano di faglia, contro cui le varie unità stratigrafiche terminano bruscamente (fig. 7). 4.2.1 stratigrafia al tetto dell’affioramento, l’unità 1, esposta per un’altezza pari a circa 40 cm, consiste di materiali di riporto nel settore più prossimo alla faglia principale, a e, e depositi detritico–colluviali rimaneggiati dalla lavorazione agricola attuale e subattuale (fig. 7), nel settore più occidentale. l’unità 2 (fig. 7), sottostante, è presente solo nel settore occidentale della parete, rastremandosi a e. si tratta di silt sabbioso scuro con ghiaia da media a fine (ø � 5 cm), con clasti calcarei a spigoli vivi. la matrice sabbiosa diventa preponderante nella “lente” individuabile nella parte sommitale dell’unità (2a in fig. 7). questo corpo lenticolare, che presenta parti a prevalente composizione argillosa di colore giallo-arancio, con screziature nerastre (campioni: co-1, co-2 in fig. 7; fig. 8) potrebbe rappresentare il riempimento di una fossa utilizzata per la cottura di materiali ceramici, riferibile (sulla base delle determinazioni sui frammenti ceramici rinvenuti) ad un insediamento eneolitico. alle attività legate alla fossa di cottura sono attribuibili i frammenti di concotto (fig. 8), vale a dire nuclei argillosi a colorazione rossastra la cui formazione è imputabile ad un processo di cottura indiretta o di surriscaldamento. nella zona più orientale di affioramento di quest’unità, si rinvengono due pietre calcaree di grandi dimensioni (ø > 30 cm), anomale rispetto al quadro stratigrafico e sedimentologico locale. esse sono probabilmente connesse al deposito archeologico sopra descritto. nel settore più occidentale del fronte di scavo, all’interno dell’unità 2, sono stati rinvenuti alcuni frammenti ceramici: • campione c1: frammento ceramico a superficie modellata con solchi. composizione argillosa, di colore aranciato e grigio, con inclusi in calcare e minerali femici. attribuibile a circa 3000-1500 anni a.c. (eneolitico – età del bronzo); • campione c2: ansa in ceramica di impasto leggermente lucidata esternamente (fig. 9); attribuibile all’eneolitico (3000-2000 anni a.c.); • campione c3: scheggia di materiale di impasto. la superficie di letto dell’unità 2 rappresenta il limite dello scavo realizzato in epoca preistorica all’interno della sottostante unità 3. l’unità 3 (fig. 7), di origine colluviale, è costituita da ghiaie supportate da una matrice sabbiosa di colore scuro. i clasti sono angolari o subangolari (ø max = 20 cm). la potenza del deposito è variabile dai 50 cm a 1 m. l’unità 4 (fig. 7) è presente solo a ridosso del piano di faglia, nel settore orientale della parete. si tratta di ghiaia in matrice sabbiosa di colore marrone chiaro, a tratti clasto-sostenuta, a tratti matrice-sostenuta, di natura colluviale. i clasti calcarei sono angolosi e di dimensioni dell’ordine della decina di cm (ø medio � 10 cm). l’unità presenta spessore decrescente allontanandosi dalla faglia e si chiude a circa 3 m da essa (spessore massimo = 40 cm). verso est l’unità è troncata bruscamente dalla faglia ed è separata da quest’ultima da uno spessore di 5-10 cm di ghiaie trascinate ed appartenenti all’unità 5 sottostante (fig. 7). le caratteristiche sedimentologiche e la diminuzione di spessore verso ovest conducono ad interpretare questa unità come il prodotto di sedimentazione dalla scarpata di faglia (i.e., “cuneo colluviale” sensu mccalpin, 1996). per quel che concerne l’unità 5 (fig. 7), su cui poggiano in contatto discordante le soprastanti unità, essa è stata suddivisa in due sub-unità sovrapposte con caratteristiche litologiche leggermente difformi. la sub-unità 5a, con spessore di 50 cm, è costituita da ghiaie con ciottoli calcarei (ø max = 25 cm) da sub-angolosi a sub-arrotondati immersi in una matrice calcarea composta da sabbia grossolana e ghiaia fine. l’unità si chiude sul piano di faglia che definisce il limite orientale dell’affioramento. la sub-unità 5b, sottostante, è invece composta da ghiaia con ciottoli calcarei di granulometria minore (ø max = 10 cm), da sub-arrotondati ad arrotondati, in matrice calcarea sabbiosa e ghiaiosa fine. la parte affiorante di questa unità, potente circa 50 cm, presenta a tratti evidente stratificazione piano parallela. 4.2.2 tettonica la successione descritta è interessata da numerosi piani di taglio e verso est termina contro la faglia f1, al letto della quale affiora il substrato carbonatico (fig. 7). nel settore occidentale della parete sono stati individuati alcuni piani di taglio minori con cinematica normale (sistema f2), che dislocano esclusivamente l’unità 5 (fig. 7). il piano f1 disloca l’intera successione ribassandola verso ovest, ad eccezione dell’unità 1. il m. saroli et al.390 fig. 7. riproduzione grafica e fotomosaico del fronte di scavo 2. unità 1: materiali di riporto nel settore più prossimo alla faglia principale e depositi detritico–colluviali rimaneggiati dalla lavorazione agricola attuale e sub-attuale. unità 2: limo sabbioso scuro con ghiaia da media a fine; presenta parti a prevalente composizione argillosa di colore giallo-arancio, con screziature nerastre. unità 3: ghiaie supportate da una matrice sabbiosa di colore scuro di origine colluviale, con spessore variabile dai 50 cm a 1 m. unità 4: ghiaia in matrice sabbiosa di colore marrone chiaro, a tratti clasto-sostenuta, a tratti matrice-sostenuta, di natura colluviale (cuneo colluviale). unità 5: è stata suddivisa in due sub-unità sovrapposte con caratteristiche leggermente difformi. sub-unità 5a, con spessore di 50 cm costituita da ghiaie con ciottoli calcarei da sub-angolosi a subarrotondati immersi in una matrice calcarea composta da sabbia grossolana e ghiaia fine; sub-unità 5b, ghiaia con ciottoli calcarei da sub-arrotondati ad arrotondati, in matrice calcarea sabbiosa e ghiaiosa fine con evidenze di stratificazione. quarry wall log and photomosaic of the quarry wall fs2. unit 1: reworked materials and colluvial deposits affected by the presentrecent agricultural works. unit 2: darkish sandy silt with medium-fine gravel, displaying portions characterised by yellowish-orange clayey with blackish levels. unit 3: colluvial gravel supported by darkish sandy matrix. unit 4: colluvial gravel with light-brown sandy matrix; showing both a matrix-supported and a clast-supported structure (colluvial wedge). unit 5: made of two different sub-units: sub-unit 5a, gravel with carbonate sub-angular to sub-rounded pebbles in coarse sandy-fine gravelly carbonate matrix; sub-unit 5b, layered sub-rounded to rounded carbonate gravel in sandy-fine gravelly carbonate matrix. nuovi dati paleosismologici ... 391 rigetto minimo stimato è di 2 m circa, calcolato misurando la differenza compresa tra il tetto della sub-unità 5b e il punto fino al quale essa è trascinata lungo il piano di faglia. nel complesso, gli eventi di dislocazione rilevati in questo fronte di scavo sono tre, tutti posteriori alla deposizione della sub-unità 5a. l’evento più antico (e3) è evidente nella dislocazione della sub-unità 5 lungo i piani di taglio (f2) presenti a ridosso del piano di faglia principale (fig. 7). la sub-unità 5a è stata erosa nel settore sollevato, al letto dei piani di taglio f2, prima della deposizione del cuneo colluviale (unità 4). ciò implica la dislocazione e la successiva erosione di 5a. l’origine dell’unità 4 (fig. 7) per erosione di una scarpata di faglia cosismica (f1) definisce un secondo evento di dislocazione (e2). il cuneo colluviale (unità 4) è in contatto discordante con l’unità 5 e da essa è separato da una superficie di erosione. tale superficie consente di differenziare gli eventi di dislocazione e2 e e3. il più recente evento di dislocazione (e1) ha interessato i depositi lungo la faglia principale (f2). esso è successivo alla deposizione delle unità 3 e 4, come evidenziato dal fatto che queste ultime sono in contatto laterale verso il piano di faglia con uno spessore pluricentimetrico di ghiaie trascinate dell’unità 5. l’evento è precedente alla deposizione dell’unità 1, che tronca la parte trascinata dell’unità 4 e che non risulta dislocata dall’attività della faglia (fig. 7). l’unità 2, contenente i frammenti ceramici eneolitici, non si rapporta al piano di faglia; è pertanto impossibile chiarire se la faglia f1 si sia attivata o meno dopo la sua deposizione. l’assenza di unità al letto della faglia non consente di effettuare una più dettagliata scansione dell’attività per singoli eventi di dislocazione. nonostante manchino vincoli cronologici di tipo radiometrico relativi all’unità 3, la correlazione stratigrafica, sulla base delle caratteristiche litologiche, tra questa e il colluvio del fronte di scavo 1 (unità 1 in fig. 4) contenente frammenti ceramici, cronologicamente compatibili con il livello di frequentazione (unità 2) scavato nell’unità 3, consentono di riferire con buona probabilità l’evento e1 ad un periodo successivo all’ eneolitico (2000-3000 a.c.). in sintesi gli eventi che hanno interessato questa successione sono, dal più antico: • e3: dislocazione delle ghiaie dell’unità 5 ed erosione della porzione superiore 5a; • e2: deposizione del cuneo colluviale (unità 4) per erosione di una scarpata cosismica; • e1: dislocazione dell’unità 3, evidenziata dal fatto che essa si relaziona con il piano di faglia f1 tramite uno spessore di depositi trascinati dalle unità sottostanti. 5. considerazioni finali sul contesto crono-stratigrafico dei paleoeventi rilevati le unità ghiaioso-sabbiose (unità 3 e 4 in fs1; unità 5 in fs2) presenti nei fronti di scavo analizzati al di sotto dei colluvi sono da considerarsi, in base alla letteratura disponibile (giraudi, 1988; 1999a) e alle evidenze sedimentologiche, deposte in ambiente lacustre prossimale. la sedimentazione delle menzionate unità sarebbe riferibile ad una fase di alto stazionamento del lago posteriore all’ultimo massimo glaciale (probabilmente avvenuta intorno a 14-15 ka b.p.; giraudi, 1988). all’episodio erosivo conseguente all’abbassamento del livello del lago sarebbero riferibili, invece, le superfici di erosione al tetto delle ghiaie delle unità 3 (fs1) e 5 (fs2). considerando 1) che la piattaforma di abrasione lacustre scolpita sui calcari al letto della faglia, modellata nel corso dell’alto stazionamento lacustre durante l’lgm (es. giraudi, 1988), rappresenta verosimilmente anche la quota dell’alto stazionamento del tardiglaciale (giraudi, 1999a) e 2) che le unità sabbioso-siltose sono riferibili a rielaborazione e rideposizione di precedenti sedimenti alluvionali in prossimità della sponda lacustre e che pertanto le unità ghiaiose rappresentano comunque sedimenti deposti nell’ambiente lacustre dell’alto stazionamento del tardiglaciale, non essendo noti livelli lacustri più recenti alle quote dell’area indagata, la differenza di quota tra la superficie di abrasione al letto delle faglie in fs1 e fs2 e quella di erosione sui depositi al tetto delle stesse può fornire un’indicazione di massima sull’entità del rigetto cumulato successivamente al tardiglaciale. tale rigetto è valutabile in max. 5 m per fs1 e in max. 2 m per fs2. attribuendo alle ghiaie un’età non più recente di 14-15 ka (in base alla letteratura disponibile; si veda ad es. giraudi, 1999a), è possibile determinare un rateo di movimento non superiore a 0.35 mm/a per la faglia f1 di fs1 ed un rateo non superiore a 0.14 mm/a per la faglia f1 di fs2. per quanto riguarda l’inquadramento cronologico degli eventi di dislocazione, in base alla bibliografia disponibile (es. galadini e galli, 1999), gli eventi e2 ed e3 individuati sui due fronti di scavo potrebbero essere assimilati a due dei tre più antichi eventi olocenici noti fig. 8. campione di argilla cotta (co1-co2 in figura 7). sample of potter’s clay from the pit-fire of fs2 (unit 2 in fig. 7). m. saroli et al.392 in bibliografia, avvenuti tra 5 e 10 ka a.c. il più recente di tali eventi (5.979-5.576 a.c.) viene fatto coincidere con la causa dei crolli registrati nella grotta continenza (giraudi, 1999b). tali crolli sono attribuiti alla cultura di ripoli (5.5-4.2 ka a.c.) da radmilli (1981). e2 ed e3 potrebbero, tuttavia, rappresentare la traccia di eventi occorsi nel pleistocene superiore finale dopo i l tardiglaciale. a questo proposito si ricorda che le informazioni paleosismologiche relative a tale contesto cronologico sono, finora, piuttosto lacunose. per quel che concerne i reperti archeologici rinvenuti nelle unità più recenti delle successioni studiate (unità 1 in fs1; unità 2 in fs2), va ricordato che essi presentano caratteristiche assimilabili a quelli trovati nelle campagne di scavo effettuate nel sito di le coste (radi, 1996, 2000; radi e ventura, 1994; radi et al., 2001), ubicato all’interno di una cava posta 500 m più a nord di fs1. i frammenti ceramici in fs1 e fs2 e le ceramiche dell’unità eneolitica rinvenuta nel sito di le coste sono affini: in particolare, il campione c2 in fs2 (fig. 9) sembra presentare caratteri del tutto comparabili a quelli delle ceramiche fini e semifini dello strato 2 del sito di le coste. inoltre, dato il quadro archeologico e le caratteristiche litologiche delle unità definite nei capitoli precedenti, si può ragionevolmente ipotizzare che la fossa di cottura individuata in fs2 e i materiali ad essa riferibili siano correlabili al deposito eneolitico della citata località. infine, i reperti archeologici rinvenuti in fs1 e fs2 consentono di riferire le unità che li contengono ad un ambito cronologico che comprende il tardo neolitico–età del bronzo (5.000–1.500 a.c.). la datazione radiometrica effettuata su un campione di materiale organico appartenente all’unità 1 di fs1 (1466-1372 b.c., età calibrata a 2 sigma), è compatibile con le indicazioni archeologiche. ciò definisce un vincolo cronologico per l’evento più recente. infatti, le rotture sui piani di faglia principali (e1 in fs1; e1 in fs2) potrebbero essere fatte coincidere con l’evento già attribuito nei lavori precedenti all’intervallo 15001300 a.c. (galadini et al., 1997a; galadini e galli, 1999 e bibliografia) (evento dell’età del bronzo) e/o, in considerazione dell’entità della dislocazione osservabile nell’unità 1 in fs1, al penultimo evento olocenico risalente all’alto medioevo (426–782 d.c., età 14c cal.; galadini e galli, 1999). a questo va aggiunto che probabilmente l’evento del 1915 ha comportato un’ulteriore dislocazione delle successioni affioranti, sebbene essa non sia direttamente rilevabile per mancanza di depositi tanto recenti conservati a ridosso della scarpata. 6. conclusioni l’analisi di affioramenti in due cave poste alla base dei rilievi che bordano il fianco orientale del bacino del fucino ha permesso di incrementare le conoscenze paleosismologiche sull’area fucense. i fronti di scavo analizzati sono posti in corrispondenza di una scarpata di faglia che costituisce parte dell’espressione superficiale del sistema di faglie dirette attivo dal pliocene e costituito dalla faglia s.benedetto dei marsigioia dei marsi e dalla faglia della s.s. marsicana. l’effetto della dislocazione osservata nelle pareti di scavo è il prodotto di movimenti ripetuti lungo uno dei piani di faglia del sistema s.benedetto dei marsi-gioia dei marsi. le analisi paleosismologiche hanno beneficiato, per l’inquadramento cronologico delle unità dislocate, di determinazioni archeologiche su frammenti ceramici e correlazioni stratigrafiche, sostanziate da una datazione radiometrica. le informazioni cronologiche hanno permesso di attribuire all’olocene gli eventi di fagliazione individuati. gli eventi di dislocazione sono da considerarsi tutti più recenti delle formazioni ghiaiose riferibili ad una fase di alto stazionamento del lago, posteriore all’ultimo massimo glaciale (probabilmente 14-15 ka b.p.; giraudi, 1988), che costituiscono la porzione basale di entrambe le successioni stratigrafiche. sul primo fronte di scavo indagato (fs1; fig. 4) sono registrati almeno tre eventi di dislocazione, correlabili a movimenti con cinematica normale avvenuti lungo il piano di faglia principale. i due eventi più antichi (e3, e2 in fig. 4) sono sicuramente posteriori alla deposizione delle ghiaie lacustri, di età prossima a 14-15 ka b.p., e probabilmente al deposito colluviale contenente i reperti eneolitici e dell’età del bronzo (fino a 3.000 b.p.) e il campione datato radiometricamente. tali eventi si collocano temporalmente tra 15.000 e 3.000 anni b.p. l’evento più recente (o serie di eventi) e1 è riconoscibile lungo il piano di faglia principale (f1 in fig. 4) ed è posteriore alla deposizione del colluvio (unità 1); pertanto esso sarebbe successivo a 1466-1372 cal. a.c. la mancanza di unità correlabili al letto e al tetto della faglia f1 non permette di fornire una scansione più dettagliata degli eventi e di valutare i rigetti reali. sul secondo fronte di scavo (fs2; fig. 7), l’analisi paleosismologica ha evidenziato l’occorrenza di tre eventi di dislocazione, riconducibili a movimenti con cinematica normale della faglia principale che borda verso est la successione di unità tardopleistocenicheoloceniche, ponendola in contatto con il substrato carbonatico. i due eventi più antichi (e3, e2 in fig. 7) sono posteriori alla deposizione delle ghiaie lacustri (unità 5) e precedenti al deposito colluviale contenente i reperti archeologici (unità 2). anche in questo caso tali eventi di dislocazione vanno riferiti ad un ambito cronologico fig. 9. frammento ceramico lucidato (c2 in fs2, fig. 7). pottery shard (c2 in fs2, fig. 7). nuovi dati paleosismologici ... 393 compreso tra 15.000 e 3.000 anni b.p. per quel che concerne l’evento più recente (e1 in fig. 7), riconoscibile sul piano di faglia f1 in fs2, esso non è completamente vincolabile da un punto di vista cronologico. in ogni caso, la presenza di un’unità attestante la frequentazione del sito, con sedimenti che riempiono una fossa scavata nel colluvio dell’unità 2, suggerisce, per comparazione con fs1, che e1 sia da riferire ad un periodo posteriore all’eneolitico. il rigetto approssimativo lungo i piani di faglia principali dei due affioramenti sarebbe non superiore a 5 m per il primo fronte di scavo e a 2 m per il secondo. attribuendo all’ultima fase di erosione delle ghiaie lacustri un’età intorno a 15.000–14.000 anni b.p. (giraudi, 1999a), è possibile stimare un rateo di movimento non superiore a circa 0.35 mm/a per la faglia f1 di fs1 e a 0.14 mm/a per la faglia f1 di fs2. nel complesso, i dati ottenuti dal presente lavoro confermano alcune conclusioni delle precedenti indagini paleosismologiche. l’insieme dei dati qui riportati deve considerarsi, pertanto, come un incremento al già cospicuo dataset paleosismologico disponibile per la piana del fucino, in un segmento di faglia contermine ad altri precedentemente indagati. l’ulteriore incremento delle conoscenze paleosismologiche, via via acquisite nel corso di quasi un decennio, contribuisce ancora di più a renderle base irrinunciabile per la caratterizzazione del comportamento sismogenetico della sorgente del terremoto del 1915. bibliografia bosi c., caiazzo c., cinque a., messina p., 1996 le superfici relitte nell’area fucense (appennino centrale) ed il loro possibile significato nella ricostruzione della evoluzione geologica. i l quaternario, 9 (1), 381-386. galadini f., galli p., 1996 paleoseismology related to deformed archaeological remains in the fucino plain, implications for subrecent seismicity in central italy. ann. geofis. 39, 925–940. galadini f., galli p., 1999 the holocene paleoearthquakes on the 1915 avezzano earthquake faults (central italy): implications for active tectonics in the central apennines. tectonophysics, 308, 143-170. galadini f., galli p., 2000 active tectonics in the central apennines (italy)input data for seismic hazard assesment. natural hazards, 22, 225 270. galadini f., galli p., giraudi c., 1997a paleosismologia della piana del fucino (italia centrale). il quaternario, 10 (1), 27-64. galadini f., galli p., giraudi c., 1997b geological investigations of italian earthquakes: new paleosismological data from the fucino plain (central italy). j. geodynamics, nos 1-4, 87-103. galadini f., galli p., giraudi c., molin d., 1995 il terremoto del 1915 e la sismicità dela piana del fucino (italia centrale). boll. soc. geol. it., 114, 635-663. galadini f., galli p., molin d., 1998 caratteristiche della sismicità della zona del fucino (italia centrale): implicazioni sismotettoniche. il quaternario, 11, 179-189. galadini f., messina p., 1994 plio-quaternary tectonics of the fucino basin and surroundings areas (central italy). giornale di geologia, serie 3a, vol. 56, n.2, 73-99. giraudi c., 1988 evoluzione geologica della piana del fucino (abruzzo) negli ultimi 30.000 anni. il quaternario, 1 (2), 131-159. giraudi c., 1995 i detriti di versante ai margini della piana del fucino (italia centrale): significato paleoclimatico ed impatto antropico. il quaternario, 8 (1), 203-210. giraudi c., 1999a. evoluzione geologica tardo-pleistocenica ed olocenica della piana del fucino e dei versanti adiacenti: analisi di nuovi dati stratigrafici e radiometrici e ricostruzione delle variazioni ambientali. in s. castenetto e f. galadini (a cura di): “13 gennaio 1915, il terremoto nella marsica”, istituto poligrafico e zecca dello stato, roma, 183-197. giraudi c., 1999b chronological assesment and paleoenvironmental implications of the speleothems from the caves of fucino plain (abruzzo, central italy) . il quaternario, 12 (1), 79-84. gruppo di lavoro cpti, 2004 catalogo parametrico dei terremoti italiani, versione 2004 (cpti04), ingv, bologna. http://emidius.mi.ingv.it/cpti04/ mccalpin j. 1996 paleoseimology. accademic press ldt., pp. 588, london. michetti a.m., brunamonte f., serva l., vittori e., 1996 trench investigations of the 1915 fucino earthquake fault scarps (abruzzo, central italy): geological evidence of large historical events. j. geophys. res. 101, 5961-5936 molin d., galadini f., galli p., mucci l., rossi a. 1999 terremoto del fucino del 13 gennaio 1915. studio macrosismico. in s. castenetto, f. galadini (a cura di): “13 gennaio 1915, il terremoto nella marsica”, istituto poligrafico e zecca dello stato, roma, 321-340. radi g., 1996 le coste. stazione dell'eneolitico e della media età del bronzo nel fucino (pescina, l'aquila), origini, vol. xix, pp. 415-445. radi g., 2000 nuovo aspetto dell'eneolitico individuato nel fucino a le coste (ortucchio aq), recenti acquisizioni, problemi e prospettive della ricerca sull'eneolitico dell'italia centrale, vol. 1, pp. 293307, arcevia radi g., berton a., castiglioni e., rottoli m., 2001 le coste, stazione dell’età dei metalli. il fucino e le aree limitrofe nell’antichità, celano, vol.1, 110125. radi g., ventura o. ,1994 nuovo sito di ceramica a squame nel fucino, r.s.p., vol. xlvi, 1, 177-190. radmilli a.m., 1981 storia dell’abruzzo dalle origini all’età del bronzo. ed. giardini, pisa, 451pp. serva l., blumetti a.m. & michetti a.m. (1986) gli effetti sul terreno del terremoto del fucino (13 gennaio 1915); tentativo di interpretazione della evoluzione tettonica recente di alcune strutture. mem. soc. geol. it., 35, 893-907. ms. ricevuto il 19 febbraio 2008 testo definitivo ricevuto il 10 giugno 2008 ms. received: february 19, 2008 final text received: june 10, 2008 m. saroli et al.394 imp.bosi pplliioo--qquuaatteerrnnaarryy ccoonnttiinneennttaall ddeeppoossiittss iinn tthhee llaattiiuumm--aabbrruuzzzzii aappeennnniinneess:: tthhee ccoorrrreellaattiioonn ooff ggeeoollooggiiccaall eevveennttss aaccrroossss ddiiffffeerreenntt iinntteerrmmoonnttaannee bbaassiinnss ccaarrlloo bboossii,, ffaabbrriizziioo ggaallaaddiinnii,, bbiiaaggiioo ggiiaacccciioo,, ppaaoolloo mmeessssiinnaa && aannddrreeaa ssppoossaattoo cnr istituto di geologia ambientale e geoingegneria, section of roma "tor vergata", roma, italy (e-mail: f.galadini@igag.cnr.it) abstract a stratigraphic framework valid for the pliocene-middle pleistocene continental deposits of the latium-abruzzi apennines has been defined through the correlation of the depositional/erosional events (indicated by stratigraphic and morphologic units, respectively) across seven different intermontane basins. this has been made by comparing the geological evolutions of the different basins. the basic assumption for the correlation of the different events is that climatic factors have conditioned the geological evolution of the investigated sector in a substantially uniform way. uniform climatic conditions have caused similar responses of the basins to the climatic changes. continental deposition in the latium-abruzzi apennines began during the pliocene, prevalently with clayey-silty-sandy lacustrine deposits fed by the clayey-arenaceous flysch into which the landscape was carved at the time of the first continental deposition. the formation of an indented landscape with higher slopes bordering the basins is demonstrated by huge landslide deposits of both arenaceous and calcareous coarse material. sediments related to the second depositional event (early pleistocene) are mainly characterised by a carbonate lithology in slope deposits (slope-derived breccias), in lacustrine (carbonate silts) and fluvial (carbonate gravels) sediments. this is due to the dominant carbonate lithology of the bedrock in the areas experiencing erosion during the quaternary. the third depositional event (related to the lower middle pleistocene) has lithological and sedimentological characteristics comparable to those of the second event. it consists, indeed, of slope-derived carbonate breccias, carbonate silty deposits of lacustrine origin and carbonate gravels of fluvial facies. the fourth depositional event (middle pleistocene) is characterised by the first significant deposition of material of volcanic origin and numerous tephra levels related to the central italy volcanic activity can be detected. chronological constraints for the second depositional event are represented by the reverse paleomagnetic polarity of the deposits, defining ages older than 0.78 ma and by the remains of arkidiscon meridionalis vestinus azzaroli in the l'aquila basin. chronological data for the third depositional event are represented by paleontological remains of equus altidens reichenau and by the association hippopotamus antiquus desmarest/elephas antiquus falc. & cautl. and by the lack of volcanic materials which became widespread after 0.6 ma. the age of the fourth depositional event is constrained by the presence of the tephra levels which define a deposition after about 0.6 ma. the attribution of a pliocene age to the deposits of the first event can only be made on a qualitative basis, since bio-chronological data or other quantitative chronological constraints are not available. in this light, the significant changes which affected the landscape between the first two depositional events seem to indicate that a very long time span passed between them. riassunto viene proposto uno schema stratigrafico per i depositi continentli dell’appenino laziale-abruzzese, fondato su una serie di correlazioni che riguardano le successioni riconosciute da precedenti lavori nelle principali conche intramontane. le successioni sono uniformemente descritte in termini di unità stratigrafiche (del tipo “a limiti inconformi”) e di unità morfologiche, definite come “unità morfo-sequenziali” e rappresentate da superfici relitte di erosione o di accumulo. le correlazioni sono state ottenute mediante un confronto fra le successioni morfologico-stratigrafiche, effettuato sulla base di due presupposti: (i) che l’evoluzione geologica che le ha generate sia condizionata principalmente da fattori in vario modo ubiquitari (clima e sollevamento tettonico) e (ii) che l’interazione fra questi fenomeni si sia realizzata in un’area caratterizzata da una relativa costanza dei principali elementi idrografici. questi presupposti inducono a ritenere che le alternanze di episodi deposizionali ed erosivi si siano sviluppate nelle diverse conche con modalità sostanzialmente simili. le correlazioni ottenute mediante questo confronto hanno portato a definire un’unica sequenza dei principali eventi deposizionali nell’area laziale-abruzzese. l’unità stratigrafica continentale più antica è costituita prevalentemente da depositi lacustri limoso-sabbiosi provenienti quasi esclusivamente da aree costituite dalle sequenze arenaceo-argillose tortoniano-messiniane. il paesaggio nel quale si originava l’unità era quindi molto diverso da quello attuale, dominato dalla dorsali carbonatiche. i bacini di sedimentazione erano verosimilmente caratterizzati da versanti molto acclivi, localmente interessati da imponenti fenomeni franosi che andavano ad alimentare una sedimentazione molto grossolana che si rinviene localmente intercalata ai sedimenti lacustri. gli strati di questa prima unità stratigrafica sono spesso vistosamente deformati. anche se non esistono elementi di diretto interesse cronologico, si può riferire l’unità ad un generico pliocene, soprattutto sulla base dei rapporti con l’unità successiva. questo riferimento è indirettamente avvalorato sia dalla "antichità" del paesaggio circostante, molto diverso da quello attuale, sia dalla deformazione, molto più intensa di tutte le unità successive che hanno di regola un assetto sub-orizzontale. il successivo evento sedimentario ha dato origine a successioni di varia litologia ed ambiente (sabbie e limi lacustri, ghiaie fluviali, depositi più o meno grossolani di versante) a prevalente componente calcarea; questa caratteristica è manifestamente connessa con una alimentazione proveniente da un paesaggio che, a seguito della sempre più profonda erosione delle sequenze terrigene mioceniche, era largamente costituito dalle successioni carbonatiche mesozoiche. l’attribuzione di queste successioni al pleistocene inferiore è giustificato dal rinvenimento, nella conca dell’aquila, di una fauna a vertebrati pre-galeriana, contenente mammuthus meridionalis vestinus. congruenti con questa attribuzione sono anche alcune determinazioni di paleomagnetismo che hanno indicato una polarità inversa. il terzo evento sedimentario ha caratteristiche abbastanza simili a quello ora descritto: se ne differenzia principalmente per la minor frequenza di episodi lacustri e per essere connesso ad una marcata tendenza all’erosione laterale che ha dato origine ad estese spianate i cui residui sono tuttora osservabili nel paesaggio. gli unici vincoli cronologici sono rappresentati da resti di equus altidens, rinvenuti nella conca del fucino e di hippopothamus antiquus e di elephas antiquus in quella del tirino. questi ritrovamenti, unitamente alla mancanza di significativi apporti in materiale vulcanici, inducono ad attribuire l’unità al pleistocene medio. il quarto evento sedimentario è caratterizzato dalla prima comparsa di importanti apporti di materiale vulcanico che danno spesso origine a sequenze di strati tufitici: l’età è ancora meso-pleistocenica in quanto precedente ai grandi apparati fluvio-glaciali del pleistocene superiore. keywords: plio-quaternary, continental stratigraphy, paleoenvironments, central italy. parole chiave: plio-quaternario, stratigrafia continentale, paleoambienti, italia centrale. il quaternario italian journal of quaternary sciences 1166(1bis), 2003, 55-76 56 c. bosi et al. iinnttrroodduuccttiioonn plio-quaternary stratigraphic frameworks are fundamental to chronologically constrain geological paleoevents which have deep implications in neotectonics and the reconstruction of recent paleoenvironments. the stratigraphic reconstructions are, however, reliable and based on tested methodologies if related to marine environments, while they are uncertain and often based on not consolidated methodologies if related to continental environments. although the above mentioned problems are sometimes unsurmountable, the object of the present paper is the definition of the continental stratigraphy of a large sector of the latium-abruzzi apennines (fig. 1), with the perspective of drawing a chronological framework for neotectonic reconstructions. the present work represents an update of the papers by bosi (1989) and bosi and messina (1991) and gathers the new knowledge supplied by investigations performed during the last ten years. due to the problems above mentioned, the discussion on the methodology adopted in the study of the continental stratigraphy is fundamental, particularly for the correlation of the successions through the different basins. for this reason a specific section will be entirely dedicated to this aspect. the proposed stratigraphic scheme of the latium-abruzzi apennine continental stratigraphy is directly linked to the methodological aspects above mentioned. therefore, the discussion of the general scheme and of the innovative aspects (with respect to the previous works) will follow the methodological discussion. the general stratigraphic scheme will also represent a sort of reference framework for the following sections, dedicated to the stratigraphic description of the investigated basins. these sections are related to the basins where researchers of the former istituto di ricerca sulla tettonica recente (presently part of the istituto di geologia ambientale e geoingegneria) have worked in the last years. for each investigated basin we cited reference studies. these studies have, however, different characteristics. in some cases they are monographies about specif ic basins (e.g. zarlenga, 1987; bertini and bosi, 1993, on the fucino basin and the middle aterno valley, respectively). in other cases, monographic studies are lacking and therefore stratigraphic data can be derived from works at the regional scale (e.g. demangeot, 1965; galadini et al., 2003, on the l'aquila basin and the turano valley, respectively). in one case (turano valley), due to the scarcity of published data, we mentioned a degree thesis (melchiorri, 1987). studies related to specific aspects of the recent geological evolution (e.g. galadini and messina, 1994; barbieri et al., in press, on the neotectonics of the fucino plain and the volcanic activity in the piana del cavaliere area, respectively) have also been mentioned. papers on specific sectors of the reported basins or to outcrop-scale stratigraphies have been referred if they seems particularly significant for the purpose of our work (e.g. bertini and bosi, 1976; blumetti et al., 1996, for the fucino and salto basins and the l'aquila basin, respectively). stratigraphic data on intermontane basins of the latium-abruzzi apennines investigated by researchers of other institutes will be summarised in only one section. in the concluding remarks some implications for neotectonics and paleoenvironmental investigations will be outlined 1. fig. 1 location map of the investigated area (latium-abruzzi apennines). 1this paper is dedicated to the stratigraphy of the pliocenemiddle pleistocene. for this reason we invite to find the available information on the late pleistocene-holocene stratigraphy of the investigated area in the numerous works made by the researchers of enea-casaccia (e.g. giraudi, 1994, 1995, 1996, 1998; giraudi and frezzotti, 1997). ggeeoollooggiiccaall ffrraammeewwoorrkk ooff tthhee cceennttrraall aappeennnniinneess the building of the central apennines results from the superimposition of the extensional tectonics to the compressive one since the late cenozoic. the latter is due to the progressive ne migration of the apennine arc related to the well-known flexural retreat of the lithosphere plate located in the adriatic sea (malinverno & ryan, 1986; royden et al., 1987; patacca et al., 1990; doglioni, 1991). contemporaneous opening of the tyrrhenian basin is due to rifting processes west of the apennine chain (e.g., faccenna et al., 1996; jolivet et al., 1999). while compressive structures affected the progressively migrating apennine front and rifting occurred in the tyrrhenian area, extensional tectonics affected the apennine chain (e.g. meletti et al., 1995; cavinato and de celles, 1999; ghisetti and vezzani, 1999), causing the displacement of the pliocenequaternary continental sediments (e.g. cnr-pfg, 1987) and the formation/evolution of intermontane basins (fig. 1). pliocene deposits, mainly represented by lacustrine facies and huge landslide episodes (the so-called "megabreccias") testify to the final emersion of the apennine chain from the sea. the ne migration of this structural system is well recognised for the compressive structures, based on the fact that progressively younger thrusts affect the italian peninsula towards ne (patacca et al., 1990). presently, the active compressive front is located in the adriatic sea along the peninsula and in the po plain in the northern apennine sector, according to the view by patacca et al. (1990). in contrast, more recent works suggest that thrusting and related folding is no more active along the apennines (e.g. di bucci et al., in press and related bibliography). progressively ne shifted intra-apennine extensional domains have also been hypothesised (e.g. lavecchia et al., 1994). the lack of a detailed stratigraphic framework related to the continental facies, however, has prevented the proposal of reliable chronological constraints for the plio-quaternary structural evolution of the intra-apennine extension. the persistence of the extensional activity in the apennines is documented by the numerous works on active tectonics and paleoseismology (e.g. pantosti et al., 1996; galadini and galli, 1999 and reference therein) and by the occurrence of earthquakes with m>6 (e.g. working group cpti, 1999). mmeetthhoodd ooff aannaallyyssiiss ooff tthhee pplliioo-qquuaatteerrnnaarryy ccoonnttiinneennttaall ssuucccceessssiioonnss the reconstruction of the continental stratigraphy at the regional scale results from fragmented information, due to the scarce lateral continuity of the depositional environments and to the intense erosion which usually affects continental areas. moreover, the chronological definition of continental successions is often hindered by 1) the scarcity of the fossil remains which is evident if a comparison with the amount of dating fossils of the marine environment is made and 2) the limit of applicability of methods for obtaining numerical datings (both in terms of material suitable for dating and in 57plio-quaternary continental deposits ... terms of chronological intervals covered by the different methods). due to these problems, since the 80s a method for correlating the continental geological history of different basins has been elaborated and applied to the latium-abruzzi apennines (see fig. 1 for location). procedures and results have already been published in the works by bosi (1989) and bosi and messina (1991). this approach is based on 1) the reconstruction of the depositional/erosional history of single intermontane basins and 2) the comparison of the successions of events which characterised the different basins of the investigated region. both points are based on the assumption that the traces of the depositional/erosional activity are roughly representative of the real geological evolution of a certain basin, if the geological history is defined through chronological steps of hundreds thousand years. the reliability of this assumption is corroborated by the evident comparability of the geological events which affected the different investigated basins (see below). as for point 1, we define the succession of the erosional and depositional events which conditioned the deposition of lithosoma over erosional surfaces, usually embedded one into the other (e.g. fig. 2). this kind of morphologic and stratigraphic relationship has been observed in all the investigated basins. the resulting landscape is made of a succession of terraced landforms, related to the top depositional surfaces of the lithosoma and/or to erosional surfaces carved into other lithosoma or the marine substratum. the comparison mentioned at point 2 is aimed at defining chronological relationships between depositional/erosional events across the different basins. the reliability of the correlation of events throughout a region is fostered by the persistence through time of the main basins and of the main portions of the hydrographic network. this persistence indicates that the terraced succession of the single depressions has to be primarily related to the climatic history of the region. this history has to be considered common to the investigated area, considering its limited extension (fig. 1). the correlation of the depositional units and the related erosional/depositional landforms across basins (the oldest with the oldest, the youngest with the youngest, etc..) is consistent with the sparse available chronological data (paleontological findings, paleomagnetic data, the presence of sedimentary materials related to the post-early pleistocene volcanic activity, see below). the correlations are also supported by other qualitative similarities regarding: 1) the number of depositional events alternating with erosional phases in adjacent basins, 2) the sedimentological and paleoenvironmental characteristics of depositional units belonging to different basins, 3) the intensity of the deformation affecting the depositional units; 4) the relationship between certain deposits and the landscape (e.g. the attitude of slope-derived breccias in comparison with the morphology of the present slopes). the procedure above described (with the evident limits due to the fragmentation of the geological information) permits to define geological events which are ubiquitous across the different basins of a region. as a result of this approach, the morpho-stratigraphic schemes we obtained for each basin (fig. 2) define the geological evolutions in terms of depositional and erosional events. these schemes are much more informative than 58 c. bosi et al. fig. 2 morpho-stratigraphic schemes of the investigated basins in the latium-abruzzi apennines. numbered columns define the different depositional events. 59 simple stratigraphic columns. the latter, indeed, do not define the "geomorphic role" of the continental evolution, since they do not indicate the fundamental processes of terracing, or the most significant areal erosional surfaces, or the depositional top surfaces, thus limiting the vision of the areal geological-geomorphological evolution. an example of correlation among depositional/erosional events of different basins contributes to cast light on the adopted procedure. this case is represented by the first continental sedimentary event which affected a number of intermontane basins of the latium-abruzzi apennines. aspects common to the different basins are: 1) this event marks everywhere the earliest deposition following the orogenic phase in the chain axis area (the continental deposits unconformably cover the marine substratum, see for example bertini and bosi, 1976 for the salto valley); 2) the lower portion of the succession (directly overlaying the marine substratum) is characterised in all the basins by clayey-sandy deposits (lacustrine environment) fed by the miocene clayey-arenaceous flysch; 3) the carbonate clastic deposition becomes predominant towards the upper part of the succession in all the investigated basins; 4) a strong tectonic deformation affects the deposits (which are tilted up to 40° and intensely faulted) in all the basins before the deposition of younger units which unconformably cover the older ones; 5) an erosional phase is in all the basins indicated by an erosional surface representing the base of the subsequent units. the five points suggest that the first depositional episodes in the different intermontane basins, with the similar characteristics above mentioned, can be related to a synchronous depositional event. obviously, sinchroneity has to be intended as chronological comparability of events within a time span of several 0.1 ma (which is the adopted "chronological scale"). the definition of common aspects in the depositional/erosional histories of basins implies that most of the field research has to be addressed to the reconstruction of geological evolution of basins (fig. 2). the chronological aspect, as indicated at the beginning of this section, is a further problem of continental stratigraphy. in the investigated region, key biochronological data are represented by arkidiscon meridionalis vestinus azzaroli (early pleistocene2; azzaroli, 1983) of the l'aquila basin, elephas antiquus italicus osborn (middle pleistocene; maini, 1956) of the middle aterno valley, equus altidens reichenau (middle pleistocene; blumetti et al., 1997) of the fucino basin, elephas antiquus falc. & cautl. and hippopotamus antiquus desmarest (middle pleistocene; gazzetti, pers. com.; petronio pers. com.) of the tirino valley. a further chronological element is represented by the presence, in the continental deposits, of abundant sedimentary material related to volcanic activity. these sediments indicate an age subsequent to the beginning (about 0.6 ma) of the most recent volcanic phase in central italy (both in the tyrrhenian sector and in the apennine area; see fornaseri, 1985; narcisi and sposato, 1989; barbieri et al., 1996 on the chronological aspects). chronological constraints can also be derived from paleomagnetic data which indicate reverse polarity for some deposits of the abruzzi apennines (d'agostino et al., 1997; messina et al., 2001), suggesting an age older than the limit bruhnes-matuyama (0.78 ma). these data are available for slope-derived breccias distributed throughout the entire latium-abruzzi apennines, for alluvial deposits of the upper aterno valley and for lacustrine sediments of the middle aterno valley. the available chronological dataset permits to constrain the age of most of the pleistocene deposits detected in the investigated area. the age of the oldest deposits, generically attributed to the pliocene in the works on the fucino plain, the salto valley and the turano valley (e.g. bertini and bosi, 1976; bosi, 1989; bosi et al., 1995), cannot be defined in detail, due to the lack of bio-stratigraphic constraints. the reasons for attributing these deposits to the pliocene are: 1) they are younger than continental sediments related to the messinian (bosi and messina, 1990; cipollari et al., 1999) which experienced the compressive deformations of the central apennines; 2) these deposits unconformably cover the miocene marine substratum (e.g. bertini and bosi, 1976); 3) sedimentary material from the lower part of the successions defines a provenance from areas not related to a physiography comparable to the present one; in particular, the abundance of clayey-sandy sediments indicates that the deposition was fed by areas entirely made of miocene flysch (bertini and bosi, 1976); in contrast, the quaternary deposition is conditioned by erosion of the carbonate bedrock in which most of the present slopes are carved; 4) the changes which affected the landscape (e.g. in terms of amount of erosion) between the first depositional event and the second one are much more significant than the changes of the landscape during the last 1 ma; 5) an erosional surface separates, in the different basins, the sediments of the first event from those related to the second (early pleistocene) depositional event (fig. 2); 6) an evident unconformity separates the sediments of the first depositional event (strongly deformed, tilted and displaced along normal faults, e.g. fig. 2) from those of the second depositional event, indicating the occurrence of significant tectonic deformations preceding the erosional surface of point 5; 7) the sediments of the first depositional event are characterised by a large thickness (more than 300 m in the salto valley and in the fucino basin) indicating the persistence of the related depositional environment for a long time interval. point 3 indicates a physiography of the first event basins very different from that of the second depositional event; points 4, 5 and 6 qualitatively indicate that a long time span separates the first two depositional events; point 7 indicates that the first depositional event may have lasted for a long period. on this basis, we hypothesise a pliocene age for the first depositional event (although it may have partly occurred during the early pleistocene). the occurrence of pliocene continental deposition in the intermontane basins of the plio-quaternary continental deposits ... 2 in the present paper, as currently proposed in quaternary geology, we consider the limit early pleistocene-middle pleistocene coinciding with the limit bruhnes-matuyama of the paleomagnetic stratigraphy (i.e. 0.78 ma). 60 latium-abruzzi apennines has also been hypothesised by other authors (e.g. cavinato, 1993; carrara et al., 1995; barberi et al., 1995; cavinato et al., 2002). the chronological attribution is generally based on considerations similar to those summarised in the previous points. tthhee llaattiiuumm--aabbrruuzzzzii aappeennnniinnee ccoonnttiinneennttaall ssttrraattiiggrraapphhiicc sscchheemmee the procedure above discussed brought to a first stratigraphic scheme at the end of the 80s (bosi, 1989) which was revised by bosi and messina (1991). in these schemes, depositional and morphological units were correlated among five different basins. the same schemes were redrawn by galadini (1999) who included information on the liri valley derived from carrara et al. (1995). other attempts to correlate continental successions in central italy have been published during the 90s (cavinato et al., 1994; cavinato and de celles, 1999). the former work tried to correlate the tectonic-sedimentary evolution of intra-appennine basins with the volcano-tectonic activity of the tyrrhenian margin. the correlation of intermontane basins (leonessa, rieti, fucino, sulmona) is made on the basis of the comparison of continental successions (for which chronological constraints are not abundant), without defining depositional/erosional histories for each of the reported basins. only the fucino basin is common to the schemes of cavinato et al. (1994) and bosi and messina (1991). cavinato and de celles (1999) is, instead, aimed at correlating geological events along a transect across central italy, thus considering the events of the tyrrhenian sector, those of the apennine chain and those of the adriatic margin during the pliocene and the quaternary. due to the non-stratigraphic aim of the paper, the authors attribute chronology to the continental successions without justifying the choices made. it is not possible, therefore, to define the reliability of the stratigraphic background. this work, however, has only the fucino and l'aquila basins in common with the bosi and messina's scheme. in the case of these basins the two stratigraphic proposals seems comparable. we updated the scheme by bosi and messina (1991), summarising the knowledge related to seven different basins (figs. 2 and 3). as indicated in the introduction, in the new scheme we defined stratigraphic and morphologic features of the basins for which the writers have had direct field experience. for this reason, the stratigraphy of the liri valley (carrara et al., 1995) is not reported in figure 3. moreover, although the stratigraphic knowledge for the rieti and sulmona basins (similar to the other investigated depressions as for the continental physiographic evolution) is very detailed (e.g. cavinato, 1993; miccadei et al., 1998a), data are not expressed through schemes similar to those of figure 2. therefore, these data cannot be used for our purposes. chronological attributions in figure 3 have to be taken with caution particularly for the age of the first depositional event above discussed. some remarks on the continental succession of this area are proposed, however, in the section dedicated to the stratigraphic data from other basins. symbols for defining lithological/sedimentological characteristics of the different units have been adopted in figure 3, together with specific symbols which permit to identify extended erosional paleosurfaces carved into the deposits and depositional top surfaces of stratigraphic units. the main differences between the old scheme and the new one are: 1) the salto and the turano valleys have been reported as two different basins, due to new fieldwork (unpublished data) made during 2001 by the authors of the present paper; 2) the tirino valley has been reported in figure 3 as the result of the work made by giuliani and sposato (1995) and further fieldwork made during 2002; 3) a third unit has been defined in the salto valley after new geological surveys made during 1999 (messina, unpublished data); 4) the stratigraphic setting of the fucino plain has been slightly changed after the fieldwork made since the beginning of the 90s (bosi et al., 1995 and further unpublished data); 5) a first depositional event has been defined in the l'aquila basin, resulting from fieldwork of the middle 90s (unpublished data); 6) a first depositional event has been tentatively defined for the middle aterno valley on the basis of geological surveys made during 2000-2001 (unpublished data); 7) new bio-chronological data have been reported (hippopotamus antiquus desmarest, elephas antiquus falc. & cautl. in the tirino valley, gazzetti, pers. com.; petronio pers. com.; equus altidens reichenau in the fucino basin, blumetti et al., 1997); 8) paleomagnetic data indicating reverse polarity of deposits, i.e. ages older than 0.78 ma have been reported (data derived from d'agostino et al., 1997 and messina et al., 2001). the most important change is, however, represented by the different location of the erosional events represented by the aquilente, mt. marine and anzano top paleolandscapes. these are extended flat and subhorizontal erosional landscapes, carved into the marine substratum. the aquilente top paleolandscape (tpl) followed, in the scheme by bosi and messina (1991), the first depositional event in the salto valley. the other two above mentioned tpls were put in the same stratigraphic position in the old scheme, although evidence for the first depositional event was lacking in the l'aquila and middle aterno basins. recent surveys in the salto valley permitted to make a different hypothesis about the relationship between the aquilente tpl and the deposits of the first depositional event (galadini et al., 2003). according to the mentioned authors, indeed, the modelling of the top paleolandscape occurred before the deposition of the first unit. this hypothesis is based 1) on the observation of coarse deposits related to the first depositional unit along the slopes roughly corresponding to the present ones and 2) on the inferred necessity of a stable base level over a large area for the formation of the aquilente tpl. point 1 defines a persistence of the salto basin slopes during time since the deposition of the first unit, i.e. a persistence of the salto depression during time. the consequence is that since the first depositional event, this area was characterised by an indented landscape. this evidence renders the hypothesis of a tpl formation subsequent to the first depositional event problematic, since the condition for a base level stable during a long time span in the tpl area (characterised, on the contrary, by unstable slopes c. bosi et al. and basin areas with lacustrine deposition), cannot be easily satisfied. similar conclusions may be drawn for the other two above mentioned tpls (mt. marine and anzano) and for this reason, following the hypothesis by galadini et al. (2003) we put the tpl remnants before the first depositional event in fig. 3. ccoonnttiinneennttaall ssttrraattiiggrraapphhyy ooff ssoommee iinntteerrmmoonnttaannee bbaassiinnss in the sections below, a short summary of the continental stratigraphy related to the basins we investigated is proposed. turano valley reference studies: melchiorri (1987); bosi (1989); galadini et al. (2003). the middle-upper turano valley was a closed basin during the first continental depositional event, as indicated by the presence of lacustrine deposits. during most of the quaternary, however, this area was drained and the old lacustrine deposits eroded. these deposits represent the lower portion of the first unit ("santa croce" in fig. 3; see also fig. 2) and are mainly made of sandy-silty deposits (fig. 4a) with sparse arenaceous and carbonate pebbles (melchiorri, 1987; bosi, 1989). the lithology of fine sediments indicates a deposition fed by the miocene clayey-arenaceous flysch extensively outcropping in the investigated area. the upper stratigraphic horizons are, instead, made of conglomerates with mainly arenaceous and secondarily carbonate pebbles (fig. 4b), alternating with sands and silts. close to the valley flanks, the presence of large boulders and blocks both arenaceous and cal61plio-quaternary continental deposits ... fig. 3 stratigraphic scheme (and morphological features related to the main erosional landscapes and top depositional surfaces) of the latium-abruzzi apennines. the available chronological constraints (bio-chronological data, volcanic deposits, paleomagnetic data) have been summarised. careous indicate instability phenomena along the basin borders during the deposition of the santa croce unit. the uppermost deposits of this unit are represented by carbonate slope-derived breccias conformably covering the mainly clayey-arenaceous deposits. these breccias define a modification of the landscape in the investigated area, since it was initially characterised by slopes mainly carved into the clayey-arenaceous flysch and subsequently (until the present) characterised by more indented slopes carved into the carbonate bedrock. the entire santa croce unit generally displays layers dipping towards n or ne (fig. 4a), i.e. the deposits are evidently tilted as a result of the activity of the nw-se normal fault bordering the depression to the ne (melchiorri, 1987; galadini et al., 2003). the thickness of the preserved deposits related to this unit can be estimated in about 200 m. the second unit ("le grotte" in fig. 3; see also fig. 2) is entirely made of carbonate slope-derived breccias, with layers dipping towards the valley, unconformably covering the older unit. the breccias are made of angular-to-sub-rounded carbonate pebbles usually in pink-orange matrix, sometimes characterised by an open-work texture. this unit is made of the typical slope-derived breccias outcropping along many slopes of the central apennines. the thickness does not exceed several tens of metres (melchiorri, 1987; galadini et al., 2003). salto valley reference studies: bertini and bosi (1976); bertini et al. (1986); mariotti and capotorti (1988); bosi et al. (1989); galadini and messina (2001); galadini et al. (2003). similarly to the previously described basin, also the middle salto valley was characterised by the presence of a lacustrine environment during the deposition of the local first unit ("piagge" in fig. 3; see also fig. 2). after the deposition of this unit, however, the basin was drained and a large part of the lacustrine deposits was eroded. presently, the salto river incides the marine substratum made of miocene flysch. the oldest geomorphic feature detected in the salto valley area is represented by the remnants of a top paleolandscape ("aquilente" in fig. 3) at 1,350÷1,450 m a.s.l. it is a flat and sub-horizontal erosional landscape which formed during a phase of stability of the base level, in a geomorphic framework completely different from the present one (galadini et al., 2003). the oldest unit outcropping in this area ("piagge" in fig. 3) defines a geological evolution similar to that of the turano valley. this unit is mainly made of fine sands and silty sands whose lithological characteristics indicates a lacustrine deposition. the pebbles of the gravel horizons are mainly arenaceous in the lower part of the succession and become more and more rich of carbonate pebbles towards the upper part. in the middle part of the succession, a several-m-thick horizon containing arenaceous boulders of tens of cubic metres (fig. 5a) was detected by bosi et al. (1989). this portion defines instability phenomena along the borders of the sedimentary basin. it is clear, indeed, that the presence of big boulders is anomalous within the lacustrine depositional environment. the thickness of the preserved deposits related to the piagge unit is larger than 300 m. outcrops of this unit have been observed between about 700 and 1000 m a.s.l. in the fiamignano area. the second unit ("canalicchio" in fig. 3; see also fig. 2) is made of a thick succession of carbonate gravels and conglomerates. sometimes, 10-m-thick layers consisting of rounded arenaceous boulders (diameter 30÷40 m) are present. the matrix in these cases has a sandy (fed from arenaceous rocks) and pebbly (carbonate pebbles) grain size. the thickness of the outcropping deposits is about 400 m (bosi et al., 1989). other horizons containing boulders have been observed in the lower part of the succession ("strati di concerviano" in bosi et al., 1989). the boulders (several cubic metres) are both arenaceous and calcareous. slope-derived breccias in the fiamignano area (fig. 5b) can also be related to the second depositional event. remnants of a flat and horizontal surface overlaying the canalicchio unit have been observed at places in the northern sector of the depression. they have been interpreted as faintly re-modelled remnants of the original depositional top surface. the third unit ("arapetrianni" in fig. 3; see also fig. 2) is entirely made of well layered gravels with 62 c. bosi et al. fig. 4 a) layered sands and silts of the first depositional units in the turano valley ("santa croce" in fig. 3); the deposits have been tilted (towards ne) as a result of the tectonic activity of the fault bordering the basin; b) sedimentological characteristics of the pebbly portion of the first depositional event (turano valley); pebbles and matrix derived from the erosion of the miocene clayey-arenaceous flysch. mainly carbonate pebbles. these deposits, outcropping in the area of the arapetrianni village, are characterised by a thickness of several tens of metres. ongoing investigations will provide more detailed stratigraphic and sedimentological information on this unit. fucino plain reference studies: beneo (1939); demangeot (1965); raffy (1970 and 1983); nijman (1971); accordi (1975); bertini and bosi (1976); zarlenga (1987); bosi and messina (1990); blumetti et al. (1993 and 1997); galadini and messina (1994); bosi et al. (1995 and 1999); messina (1996); cavinato et al. (2002). the fucino plain has been investigated by researchers of different institutions during time (fig. 6). most of the works have been made in the neotectonic perspecti63plio-quaternary continental deposits ... fig. 5 a) arenaceous blocks in sandy matrix related to the first depositonal unit of the salto valley ("piagge" in fig. 3); b) layered slope-derived breccias of the second depositional unit in the salto valley; the breccias are presently dipping into the slope as a result of tilting due to gravitational phenomena. ve, to evaluate the history of the vertical movements in sectors separated by plio-quaternary faults or to define the recent structural evolution. the large number of available studies (whose conclusions in stratigraphic terms are summarised in fig. 6) is due to the fact that the continental deposits in the fucino area outcrops much more extensively than in other central apennine intermontane basins. this is a paradox if one considers that the fucino basin is the only presently closed depression among the basins investigated in the present paper, that is the erosion of a river has not entrenched the continental deposits. indeed, the structural framework of this area, with parallel normal faults which isolate "slices" of continental deposits and suspend them over the present plain bottom, is the main cause for the "visibility" of the plio-quaternary deposits. we took stratigraphic information on the fucino basin from the works by bosi et al. (1995 and 1999), although a more recent work is available (cavinato et al., 2002). the authors of the latter work, indeed, do not 64 c. bosi et al. fig. 6 schematic representation of the available knowledge on the fucino stratigraphy according to the different works. take into account the evidence of erosional phases which are clearly recorded in the fucino landscape as remnants of extended erosional paleosurfaces carved into the continental deposits (see section dedicated to the general stratigraphic scheme for a discussion). this limits the use of the stratigraphic data in the perspective of the continental geological evolution and, in practical terms for our paper, does not permit to give a picture of the fucino stratigraphy comparable to that of the other basins. the oldest unit ("aielli" in fig. 3; see also fig. 2) outcropping in the fucino area (mainly along the northern basin border) is made of clays, silts and sands of greyish and yellowish colour (fig. 7a), mainly related to a lacustrine environment. outcrops of the basal horizons have been observed at 750 m a.s.l. in the aielli area. as in the previous cases, the lithology reveals that deposition was fed by the miocene flysch. in the middle part of the succession (900 m a.s.l.), the percentage of gravel layers increases. the gravels are mainly made of carbonate pebbles (subordinately arenaceous pebbles) in sandy matrix. the upper part of the succession is made of breccias laterally transient to gravels, sands and layered silts dipping towards nne. the breccias contain carbonate blocks with volume up to hundreds of cubic metres. the presence of million-cubic-metres blocks defines significant instability of the slopes close to the basin at the time of the first unit deposition. the uppermost portion of the succession is exposed at about 1,050 m a.s.l., north of the aielli village. the thickness of the outcropping deposits is about 400 m. the second unit ("cupoli" in fig. 3), embedded in the older one (fig. 2) is exposed between celano and aielli and along the eastern basin border. it consists of gravels intercalated with sands and, more rarely, with silty-clayey horizons. whitish silts outcropping between collarmele and pescina, unconformably covering the pliocene deposits and underlaying the pescina unit, have been attributed to the cupoli unit by bosi et al. (1995). the depositional environment is lacustrine and fluvial. the maximum thickness of the outcropping deposits is about 120 m. in the area of cupoli, a flat and sub-horizontal surface ("alto di cacchia" in fig. 3) is carved into the uppermost portion of this unit (fig. 7b). this surface probably represents a faintly modified remnant of the original depositional top surface. faults affecting the deposits related to the cupoli unit and the tilted geometry of the whitish silts along the eastern basin border define the significant tectonic activity experienced by the sediments of the second unit. when the deposition related to the second unit occurred within the basin, the "bisegna breccias" (bosi and messina, 1990) deposited along the slopes (fig. 7c). the breccias are the typical product of the slope deposition related to the second unit in all the basins discussed in the present paper. they are made of carbonate angular pebbles in pink-orange sandy-silty matrix, are well layered and usually dipping towards the basin or characterised by a sub-horizontal attitude. the main outcrops of breccias have been detected along the southern slope of the tre monti relief, the southern slope of the magnola mts. and the left flank of the 65plio-quaternary continental deposits ... fig. 7 a) alternating sands and gravels of the upper portion of the first depositional unit ("aielli" in fig. 3) in the fucino basin (photograph taken at the beginning of the 90s at the southern entry of aielli); b) panoramic view (from wnw) of the cupoli hill, entirely carved into the gravels and silts of the second depositional unit; the top of the hill (encircled by the black line) roughly correspond to the depositional top surface of the deposits; c) slope-derived breccias of the fucino second depositional unit, along the southern slope of the magnola mts. (northern border of the fucino basin); d) layered gravels of the fucino third depositional unit ("pescina-casoli-pervole" in fig. 3) along the giovenco valley (eastern border of the fucino basin); the white arrow indicates a fault affecting the gravels. celano gorge. a mature red paleosol developed over the "bisegna breccias" along the southern slope of the tre monti relief. the maturity of the paleosol and the comparison with similar soils in other parts of the apennines suggest an age of several hundreds thousand years (magaldi, pers. com.). the third unit ("pescina" in fig. 3), embedded in the second one (fig. 2), is prevalently made of carbonate gravels outcropping along the eastern basin border (fig. 7d). the sedimentological characteristics define a fluvial environment ("braided stream"). the maximum thickness of the outcropping deposits is about 50 m. a fragment of equus altidens reichenau has been found within this unit by blumetti et al. (1997) in a pedogenized reddish soil sediment. this remains permits to relate the deposits to the early-middle middle pleistocene. stratification is generally sub-horizontal or slightly dipping into the slope as a result of the tectonic tilting. the tectonic suffered by this unit (fig. 7d) is also indicated by the fault planes detected in the gravels by bosi et al. (1995). the depositional top of the pescina unit is not preserved and the layers are truncated by erosional surfaces at about 870 m a.s.l. at lower elevations, in the same area where the pescina deposits have been identified, slightly younger deposits have also been detected by bosi et al. (1995) and messina (1996), included in the pescina unit in the scheme of figure 3. these deposits have been reported as "casoli", "collarmele" and "pervole formations" in the mentioned papers. they consist of gravels and sands of fluvial origin; their depositional top surfaces are, in these cases, well preserved. the fourth unit ("boscito" in fig. 3; see also fig. 2) marks the beginning of the volcanic deposition in the fucino basin. it consists of sands rich of volcanic minerals and subordinately carbonate gravels of fluvial origin. it can be related to the middle pleistocene on the basis of the chronological data on the beginning of the most recent volcanic phase in central italy (fornaseri, 1985; narcisi and sposato, 1989; barbieri et al., in press). sangro valley reference studies: colacicchi (1967); aa.vv. (1986); galadini and messina (1990, 1993a, 1993b); galadini et al. (1998); pace et al. (2002). the oldest unit of the sangro valley outcrops along the southern margin of the pescasseroli basin ("campo rotondo" in fig. 3; see also fig. 2) between 1,200 and 1,450 m a.s.l. it is made of carbonate cobbles and boulders (fig. 8a) with dimensions up to some cubic metres and directly overlays the marine substratum. fieldwork permitted to identify few blocks with dimensions up to 40÷50 cubic metres. the thickness of the preserved deposits related to this unit is about 60÷70 m. the deposition is due to large landslide episodes related to landscapes which are no more preserved (galadini and messina, 1990). the mentioned authors also mapped some nw-se faults responsible for the displacement of the campo rotondo unit. the second unit ("pescasseroli" in fig. 3; see also fig. 2), embedded in the older one, is made of gravels and conglomerates laterally transient (towards the valley flanks) to slope-derived breccias (figs. 8b, c and d). few layers of sands and silts have been detected within the carbonate gravels. the attitude is generally subhorizontal (fig. 8d); grading is both normal and reverse (galadini and messina, 1993a). the breccias are made of carbonate angular pebbles and cobbles and are characterised by a varied degree of cementation. the calcareous sandy matrix has often a pinkish colour. layers are generally dipping towards the valley and present a sub-horizontal attitude in the area of transition to the gravels (galadini and messina, 1993a). the lithological characteristics and the stratigraphic position within the continental succession of the sangro basin permits to correlate these breccias with the second unit breccias extensively outcropping in other basins of the central apennines. the pescasseroli unit is characterised by a maximum thickness of 140÷150 m. remnants of the depositional top surface are sporadically preserved at elevations between 1,460 and 1,470 m a.s.l. the described unit is clearly affected by tectonic displacements. the most evident effect of the recent tectonic activity is represented by the 60÷120 m high fault scarp separating the colli alti and the colli bassi areas, close to pescasseroli (fig. 8b). the fault scarp is entirely carved into the gravels and conglomerates of the described unit. the third unit ("spineta" in fig. 3; see also fig. 2) is entirely made of slope-derived carbonate breccias, with angular pebbles of dimension up to 20 cm, in carbonate sandy matrix of generally whitish colour. the thickness does not exceed 10 m. since direct chronological constraints for the described units are lacking, their position in the chronological framework of figure 3 has been defined by correlating the sangro valley deposits with those of the fucino area (galadini and messina, 1993a). correlation has been based on the comparison of the quaternary geological history of the two adjacent basins. as usual, the slope-derived breccias of the early pleistocene, due to their deposition along most of the central apennine slopes, represent a fundamental unit for the definition of chronological constraints. continental deposits have also been detected in the southern part of the upper sangro valley. they mainly consists of slope-derived breccias outcropping along the southern slope of mt. greco (aa.vv., 1986; pace et al., 2002). most of the breccias mapped in aa.vv. (1986) in this area can be attributed to the second unit. on the basis of the work by pace et al. (2002) it is clear, however, that also more recent slope deposits outcrop. ongoing investigations by the authors of the present paper will define a detailed stratigraphy for this sector. l'aquila basin reference studies: demangeot (1965), bosi (1989); blumetti et al. (1996); messina et al. (2001). the oldest geomorphic feature preserved in the l'aquila basin (corresponding to the area of the upper aterno valley) is represented by the remnants of a flat and sub-horizontal tpl, at elevations between 1,400 and 1,500 m a.s.l. it is carved into the meso-cenozoic carbonate succession and the clayey-arenaceous flysch of miocene age. the major remnants of the paleolandscape are preserved in the footwall of the mt. marine fault. considering the large extension of the mt. marine tpl and therefore the evidence for its formation during a phase of stability of the regional base level (i.e. when 66 c. bosi et al. a local basin was not present), we believe that the l'aquila basin formed as the result of the mt. marine tpl displacement, according to models already published in basili et al. (1999) and galadini et al. (2003). the oldest unit ("pianola" in fig. 3; see also fig. 2) outcrops south of the l'aquila basin and is made of layered sands and silts of prevalently lacustrine origin. the mineralogical composition is represented by abundant quartzose, plagioclase and muscovite granules which indicate that the deposition of this unit was fed by the miocene flysch. the investigated outcrops showed that the deposits are intensely deformed, as indicated by the number of outcrop-scale faults and by the attitude of the layers, suggesting a tilting of 15÷20° towards north. sandy-silty deposits (intercalated with gravels) have been paleomagnetically analysed in the northernmost sector of the l'aquila basin (area of barete). the analysis defined a normal polarity (messina et al., 2001). since these sediments represent the oldest unit of the area, the mentioned authors hypothesised an age older than 1,770 ma, thus providing evidence for the presence of pliocene deposits in the upper aterno valley. the second unit ("madonna della strada-san marco" in fig. 3; see also fig. 2) can be detected between 680 and 1,010 m a.s.l. and is made of alternating silts and sands in the lower part and gravels (coarsening upward) in the upper part. the arkidiscon meridionalis vestinus azzaroli was found in the lower part of this unit (azzaroli, 1977). this unit is probably ("question mark" in fig. 3) laterally transient to slope-derived breccias which extensively outcrop along the northern portion of the mt. pettino fault ("san marco breccias", fig. 9a). this hypothesis is not based on direct field observation but on the similarity of the l'aquila basin stratigraphy with that of the other basins where the lateral transition from basinal to slope-derived breccias was observed in the field. paleomagnetic analyses sho-wed a reverse magnetic polarity for the breccias, thus indicating an age older than the bruhnes-matuyama li-mit (0.78 ma) (messina et al., 2001). similar results have been obtained from paleomagnetic analyses on the alluvial succession of the cona della croce excavation (fig. 9b), south of arischia (messina et al., 2001). these deposits have been related to the second depositional event by the mentioned authors. two different erosional surfaces (preserved as remnants in the landscape of the l'aquila basin) are carved into the deposits of the second unit. the remnants of the highest and oldest surface ("colle di sassa" in fig. 3) can be detected at 800÷900 m a.s.l., while the 67plio-quaternary continental deposits ... fig. 8 a) blocks of the first depositional unit of the upper sangro valley (campo rotondo area, pescasseroli basin); b) panoramic view (from north) of the pescasseroli basin (upper sangro valley); most of the depression is filled by gravels and conglomerates of the local second depositional unit ("pescasseroli in fig. 3); the white arrows mark the base of the scarp affecting the colli alti-colli bassi area, resulted from the activity of a fault which displaced the top depositional surface of the sediments; c) view of the conglomerates of the second depositional unit and of the landscape roughly corresponding to the top depositional surface in the colli alti area (eastern pescasseroli basin, upper sangro valley); d) detail of the sub-horizontal conglomerates of the second depositional unit in the upper sangro valley; carbonate pebbles are angular, indicating a proximity to the slope. lowest surface ("san bartolomeo" in fig. 3) is preserved at 775÷800 m a.s.l. (fig. 9c). the third unit ("civitatomassa" in fig. 3; see also fig. 2) is made of gravels related to a fluvial depositional environment. the top depositional surface of this unit is preserved at places (at 730÷740 m a.s.l.) and it may be correlated (on the basis of the altitude and of the relationship with the other, older and younger, paleosurfaces exposed in the area) with the above mentioned erosional surface of "san bartolomeo" (fig. 9c). part of the successions described by blumetti et al. (1996) for this area are related to the madonna della strada unit. they are mainly made of sands and gravels, while the colle macchione succession (about 25 m thick), mainly consists of "megabreccias" with carbonate blocks of several cubic metres overlaying sandy silts of lacustrine origin. the authors defined a debris flow origin for the "megabreccias". younger sediments have also been found in the 15-m-thick case buccella succession, made of gravels (with cut-and-fill structures) alternating with sands. the presence of abundant volcanic minerals may indicate a middle pleistocene age (on the basis of the chronology of the central italy volcanic activity). these sediments may represent a local fourth unit. the lack of conclusive data on this point, i .e. the impossibility to exclude that these deposits are signif icantly more recent than the beginning of the volcanic activity, presently prevent the representation in figure 3. middle aterno valley reference studies: demangeot (1965); bosi and bertini (1970); bagnaia et al. (1989); bertini et al., (1989); galadini and giuliani (1991); bertini and bosi (1993); d'agostino et al. (1994 and 1997). as in the case of the previously described basin, also in the middle aterno area remnants of an old tpl ("anzano" in fig. 3) have been detected at about 1,400÷1,500 m a.s.l. the tpl is carved into the marine carbonate substratum and is suspended of about 1,000 m over the aterno depression. since all the outcropping deposits and the related geomorphic features (both erosional and depositional top surfaces) are embedded into the tpl, the latter is the oldest geomorphic feature detectable in the investi68 c. bosi et al. fig. 9 a) panoramic view of the san marco area (l'aquila basin, upper aterno valley); outcropping rocks are made of cemented slope-derived breccias of the second depositional unit; paleomagnetic analyses indicate an age older than the limit bruhnes-matuyama (0.78 ma); b) gravels, sands and silts of alluvial origin, related to the second depositional unit, in the arischia area (excavation of cona della croce; upper aterno valley); also in this case the paleomagnetic analysis gave an age older than the limit bruhnes-matuyama (0.78 ma); c) panoramic view from scoppito towards south (l'aquila basin, upper aterno valley); the arrows indicate the remnants of the san bartolomeo surface, roughly corresponding to the depositional top of the third depositional unit. gated area (galadini et al., 2003). the oldest deposits detectable in the area of the middle aterno valley ("campana" unit in fig. 3) have been observed in the lowest sector of the tectonic depression which formed in the area between san demetrio ne' vestini and barisciano. similarly to other investigated basins, the lithology of this unit, mainly made of sands, indicates a deposition fed by the miocene flysch. about 6 km north of barisciano, in the area of mt. ruzza, slope derived breccias outcrop extensively. the cemented breccias are displaced and affected by fault scarps. the deposition occurred over the anzano tpl and the sub-horizontal attitude indicates that it affected an area with scarce relief energy. this means that the breccias deposited before the formation of the middle aterno valley depression, whose bottom is located about 1,000 m below the anzano tpl. although these breccias represent the oldest depositional episode in the area where the anzano tpl is preserved, the relationship with the sands of campana cannot be defined. similarly to other basins, the mt. ruzza breccias may represent the typical product of deposition in slope areas in a period during which the innermost portion of the basin was characterised by the deposition of the sands of campana. in the second unit ("fonte vedice-san nicandro" in fig. 3; see also fig. 2) we put different sub-units. the oldest sub-unit is represented by the san nicandro whitish silts (bosi and bertini, 1970; bertini and bosi, 1993), related to a lacustrine environment. the silts are well layered, sometimes laminated and affected by significant tectonic deformation indicated by the numerous outcrop-scale faults which can be detected in the investigated area and by the tilted geometry of the layers (fig. 10a). paleomagnetic analyses made on the san nicandro silts defined a reverse magnetic polarity (speranza pers. com.) which indicates an age older than the bruhnes-matuyama limit (0.78 ma). these silts are laterally transient to slope derived breccias made of angular to sub-angular carbonate pebbles and cobbles (fig. 10b) in carbonate sandy matrix ("valle valiano formation" in bertini and bosi, 1993). the breccias are well layered and usually (when not affected by tectonics) dip towards the aterno basin. the "fonte vedice breccias" represent a younger sub-unit made of the typical cemented carbonate breccias with orange-pink matrix widely outcropping in the entire abruzzi region (bertini et al., 1989). d'agostino et al. (1997) defined a reverse paleomagnetic polarity which suggests an age older than 0.78 ma. the breccias can be detected along the slopes bordering minor depressions between the barisciano sector of the middle aterno valley and the gran sasso chain (bertini et al., 1989). according to bertini and bosi (1993), these breccias are laterally transient to conglomerates of fluvial origin ("valle colle formation" in bertini and bosi, 1993) in the area wnw of barisciano. extended remnants of an erosional paleosurface ("petrara" in fig. 3) is carved into the deposits of the second unit (san nicandro silts, valle valiano breccias) and into the carbonate units of the marine substratum (bertini and bosi, 1993). the third unit ("valle dell'inferno" in fig. 3; see also fig. 2), embedded in the second one, is made of well-layered gravels and conglomerates intercalated with silty-sandy levels (fig. 10c). this unit sometimes covers lens-shaped levels of a reddish soil sediment, similar to that previously mentioned in the fucino basin, which gave the remains of equus altidens reichenau. its top depositional surface is preserved in many places ("valle daria" in fig. 3; fig. 10d) and is laterally transient to an erosional paleosurface carved into the marine substratum. the fourth unit of the middle aterno valley ("san mauro-san giovanni" in fig. 3; bertini and bosi, 1993), is made of carbonate gravels and sands in the lower part ("san giovanni formation" in bertini and bosi, 1993). the upper part ("san mauro formation" in bertini and bosi, 1993) is made of gravels and sands passing upward to sands intercalated with tuffite levels and layers rich of mammal bones. a peculiar aspect is represented by the abundance of tephra levels which, instead, are completely absent in all the preceding units. the youngest phase of volcanic activity in central italy began during the middle pleistocene (fornaseri, 1985; narcisi and sposato, 1989; barbieri et al., in press) and this age is usually attributed to the oldest continental deposits showing abundant tephra levels in the central apennines (see bertini and bosi, 1993 for the specific case of the middle aterno valley). this age is also consistent with the elephas antiquus italicus osborn reported in maini (1956) and found in the upper portion of the fourth unit. the depositional top surface of the fourth unit (san martino in fig. 3) is sparsely preserved throughout the investigated area. tirino valley reference studies: bosi and locardi (1991); giuliani and sposato (1995). differently from the previously mentioned basins, no evidence of deposits which may be related to the first depositional event has been found in the depressions of the tirino valley (fig. 11a). the oldest deposits of the local succession, indeed, are represented by the slopederived breccias ("villa santa lucia" in fig. 3; see also fig. 2) lithologically comparable to the second event breccias extensively outcropping in the central apennines and directly overlaying the marine substratum (fig. 11b). these breccias are made of carbonate angular pebbles in sandy matrix characterised by the typical pink-orange colour. they are layered and usually dip towards the basin (fig. 11b). outcrops of breccias have been found between 600 and 1,100 m a.s.l., sometimes with evidence of tectonic displacements (giuliani and sposato, 1995; fig. 11b). a younger unit ("convento dei cappuccini" in fig. 3), embedded in the older one (fig. 2), is made of whitish silts of lacustrine origin laterally transient (towards the basin borders) to slope-derived carbonate breccias. the silts are layered, sometimes laminated. sparse layers of sands and gravels have also been detected (giuliani and sposato, 1995). in the area of bussi officine, remains of elephas antiquus falc. & cautl. and hippopotamus antiquus desmarest have recently been found. this paleontological association define an age related to the lower part of the middle pleistocene (petronio, pers. com.). the area of these findings is very important since it represents the zone of transition from the tirino basin to the sulmona basin. according to giuliani and sposato (1995), the whitish silts observed in a borehole (made in the tirino plain) up to 150 m below the ground surface may be related to the convento dei cappuccini unit. outcrops 69plio-quaternary continental deposits ... related to these lacustrine deposits have been detected between 430 and 500 m a.s.l. slope-derived breccias have been observed at elevations usually lower than 600 m a.s.l. and are clearly embedded in those related to the villa santa lucia unit. as in the case of the older unit, also the convento dei cappuccini breccias dip towards the basin. the entire unit (breccias plus silts) has been affected by tectonic deformation (giuliani and sposato, 1995). a younger unit ("bussi" in fig. 3; see also fig. 2), embedded in the second one, is made of sands, gravels and silts of fluvial and lacustrine origin, containing a high percentage of volcanic minerals which give a greyishbrownish colour to the fine lacustrine sediments. the deposits related to this unit outcrops between 340 and 420 m a.s.l. the depositional top surface is usually well preserved and easily detectable. the bussi unit represents the first local depositional episode affected by abundant tuffite levels. for this reason it has been correlated with the tuffite succession of carapelle calvisio (giuliani and sposato, 1995), found in a closed depression near the main tirino basin by bosi and locardi (1991), ssttrraattiiggrraapphhiicc ddaattaa ffrroomm ootthheerr bbaassiinnss further works have been published at the end of the 80s or during the 90s which reported stratigraphic information on intermontane basins not discussed in the previous sections. data on the rieti basin can be derived from the works by bosi et al. (1989), cavinato et al. (1989), cavinato (1993), barberi et al. (1995) and cavinato et al. (2000). continental deposits mapped in cavinato (1993) and barberi et al. (1995), mainly consisting of conglomerates and breccias, have been attributed to two main units. the oldest one has been related to the upper pliocene-early pleistocene and the youngest to the early pleistocene. the age of the second unit has been defined on the basis of remains of equus stenonis cocchi (cavinato et al., 1989). in the piana del cavaliere area, deposits characterised by predominant material of volcanic origin with thickness of several metres have been detected (barbieri et al., 1996 and in press). radiometric analyses (40ar/39ar) made by the mentioned authors gave an age of 0.531 ma. although this age is consistent with the chronology of the volcanic activity in the tyrrhenian area, the sr isotope ratios suggest that the deposit originated from local volcanic activity. the nature of the deposits indicates that this activity is related to a surge volcanism. these data increase the importance of the intra-apennine volcanic activity, already documented in the work by bosi and locardi (1991) for the tirino basin. information on the continental deposits in the liri valley can be found in devoto (1965 and 1967) and carrara et al. (1995). the latter authors divided the suc70 fig. 10 a) carbonate silts of lacustrine origin related to the second depositional unit of the middle aterno valley; the silts have been tectonically tilted and are affected by a fault passing close to the head of the geologist (photograph taken at san pio delle camere, in a temporary excavation); b) view of the "valle valiano breccias", second depositional unit, along the road between barisciano and santo stefano di sessanio (middle aterno valley); note the huge block exposed in the central part of the photograph; c) gravels of the third depositional unit of the middle aterno valley, underlaying the surface of valle daria; note the unconformity marking the separation between two different sub-units; d) panoramic view of the valle daria surface, representing the depositional top of the third unit of the middle aterno valley. c. bosi et al. cession in different units and defined chronological constraints. therefore, in the mentioned work, pliocene, plio-pleistocene, early pleistocene, middle pleistocene and late pleistocene-holocene deposits are described. the pliocene deposits are represented by the "breccias of the 1st depositional phase", mainly made of carbonate angular pebbles and related to depositional environments completely different from the quaternary ones. the authors included the "santopadre formation" in the deposits of plio-pleistocene age. the lower part of this "formation" is made of sandy-silty horizons alternating with clayey-silty levels rich of organic matter of fluvial, lacustrine and marshy environments. an erosion surface separates this portion from the upper part of the succession made of conglomerates with mainly carbonate pebbles, without sedimentary material of volcanic origin. the thickness of the outcropping deposits is several hundreds metres. the "breccias of the 2nd depositional phase" have been included in the early pleistocene deposits. they are made of carbonate angular pebbles and at places are laterally transient to conglomerates. the breccias experienced quaternary tectonic activity, as indicated by the numerous fault planes detected in the investigated outcrops. the same chronology has been attributed to the "veroli alluvial fan" and to the "breccias of the 3rd depositional phase" which can be observed among the deposits of old alluvial fans displaced by the local fault bordering the val roveto depression. products of the volcanic activity have never been observed in the "breccias of the 3rd phase" to which a pre-middle pleistocene age has been attributed by carrara et al. (1995). the "breccias of the 4th depositional phase" represent the youngest deposits without minerals of volcanic origin and have been related to the middle pleistocene. the first deposits characterised by the presence of tephra levels have been reported as "fluviolacustrine complex of the sora basin and lirino lake" by carrara et al. (1995). these deposits consist of gravels and sands of fluvial origin and clayey silts and sands of lacustrine environment. volcanic levels have been dated at 0.58÷0.35 ma by the mentioned authors. further middle pleistocene deposits (embedded in those previously reported) have been described for this area by carrara et al. (1995). however, since their age is younger than that of the 4th unit deposits described in the previous sections, the description is beyond the scope 71 fig. 11 a) panoramic view of the depressions in the tirino valley area; the carapelle, chiancarelli and upper tirino valley basins are separated by low carbonate hills elongated in a n-s direction; b) slope-derived breccias (more than 20 m thick) related to the second depositional event, outcropping along the northern border of the carapelle depression; the white arrows indicate a fault affecting the breccias. plio-quaternary continental deposits ... of the present paper. data on the stratigraphy of the subequana basin have been published by miccadei et al. (1997). the authors identified the typical breccias we related to the upper early pleistocene and more recent deposits both of lacustrine and fluvial origin. these younger deposits are characterised by the presence of centimetric volcanic levels and therefore they have been attributed to the middle pleistocene. other alluvial fan deposits and paleosols have been related to the late pleistocene or to the upper middle pleistocene. a number of papers have been dedicated to the sulmona basin (miccadei et al., 1992 and 1998a; sylos labini et al., 1993; vittori et al., 1995; cavinato and miccadei, 1995 and 2000; ciccacci et al., 1999). these works define a continental succession which begins with breccias related to the early pleistocene. the deposits may be correlated with the slope-derived breccias of the second unit reported in the previous sections, based on their facies and stratigraphic posit ion. middle pleistocene deposits are related to fluvial and lacustrine environments, the latter being indicated by typical whitish silts. as in the other areas, sediments containing abundant volcanic minerals or tephra levels have been observed in the sulmona plain. these sediments have been related to post-0.6 ma deposition. preliminary works are available for the continental stratigraphy of the sagittario valley and the cinquemiglia plain area. as for the former, deposition began during the early pleistocene with slope-derived breccias (barberi et al., 2001). our recent surveys in this area permitted to identify slope-derived breccias laterally (towards lower elevation) transient to conglomerates. these deposits may be related to the early pleistocene. moreover, our data indicate that an older unit is present in the area and made of breccias which deposited in an environment completely different from the present one (and not related to the mentioned conglomerates), in the serra di ziomas area. in the case of the cinquemiglia plain area, miccadei et al. (2001) defined a continental succession whose deposition occurred since the lower middle pleistocene. the oldest deposits are represented by the slope-derived breccias which deposited along the sw slope of mt. pizzalto (already mapped by miccadei et al., 1998b and attr ibuted to the middle-late pleistocene). however, our preliminary surveys permit to relate these breccias to the typical slope deposits of the second depositional event (e.g. the fonte vedice breccias of the middle aterno valley), based on the facies and the stratigraphic position. if this hypothesis is confirmed, the age of the breccias would be slightly older than that proposed by miccadei et al. (2001). the continental deposits of the amatrice basin have been entirely related to the quaternary (cacciuni et al., 1995). the mentioned authors identified alluvial fan deposits, landslides and pediments and defined eight units. the oldest unit (sommati-amatrice) detected outcrops between 960 and 1,100 m and mainly consists of alluvial fan laterally transient to fluvial deposits and accumulations of paleolandslides. although the authors does not report explicitly the age of the unit, they relate the beginning of the deposition in the amatrice area to the early-middle pleistocene. this age can be, therefore, attributed to the sommati-amatrice unit. ccoonncclluuddiinngg rreemmaarrkkss in the previous sections we summarised the available data on the pliocene-middle pleistocene continental stratigraphy. the general scheme we propose has been drawn on the basis of the "correlation procedure" above described. the general view of the continental stratigraphy of the latium-abruzzi apennines, although the knowledge is far from being complete, permits to point out some aspects which have significant implications in the paleoenvironmental and neotectonic perspective. these aspects will be briefly summarised in the points below. 1) in almost all the basins, where the first depositional event has been identified, the lower part of the successions is characterised by sediments fed from the clayey-arenaceous flysch (turano, salto, fucino, l'aquila). this means that, at least in these basins, when the continental evolution began, the landscape was extensively carved into these marine units, differently from the quaternary landscape which was carved into the carbonate substratum. 2) in most of the basins where the first depositional event has been defined, very coarse deposits have been detected. these deposits are generally related to huge landslide phenomena within the lacustrine basins and define instability of the slopes bordering them. these sedimentary episodes i) mark the progressive indentation of the landscape as a result of the regional uplift and ii) indicate that slopes bordering basins with significant amplitude of relief where already present in the central apennines during the first depositional event. 3) all the investigated basins present on their borders the typical slope-derived breccias of the second depositional event which can be related to a period preceding 0.78 ma (based on paleomagnetic data). the ubiquitous presence of these breccias is probably related to climatic factors which conditioned the widespread deposition. since chronological data continuously corroborates the previous chronological hypotheses, the breccias may be considered as a stratigraphic marker of regional importance for the definition of paleoevent chronologies or the evaluation of tectonic rates. 4) the correlation between deposits and landforms related to the third event of the proposed stratigraphic scheme seems convincing due to the peculiar geomorphologic features which characterize this event. indeed, the deposits are bounded upward by an important flat landform partly representing the depositional top of the units, in the l'aquila, middle aterno valley and fucino basins. the surface overlays a typical reddish soil sediment in the latter two mentioned basins. 5) a further important stratigraphic marker is represented by the units recording the beginning of the volcanic activity. the investigations of the last ten years corroborate the previous hypotheses of middle pleistocene age for the first sediments containing volcanic minerals or tephra levels. generally speaking, the proposed correlations give the impression of the comparability of the depositional events in the different basins. this comparability may be interpreted as the effect of diachronous basin evolutions, each evolution passing through characteri72 c. bosi et al. stic steps which are the same for the different basins. this hypothesis would strongly contradict the possibility to correlate the depositional events across different basins on a chronological basis. it is evident, however, that an evolution of this kind cannot justify the evident comparability (across the different basins) of the succession of events (depositional, erosional) discussed in the previous pages. the comparability of successions of events (their number, the paleoenvironmental aspects, etc..) necessarily defines their sinchroneity, since it implies that the events are due to ubiquitous geomorphic agents. on this basis, we consider the proposed stratigraphic scheme as a reliable starting point for chronologically constrained neotectonic evaluations. the data summarised in the scheme proposed above and the available knowledge from the other basins not investigated by the authors of the present note indicate the lack of deposits related to the first depositional event in the easternmost depressions (e.g. tirino valley, sulmona plain, amatrice basin). this may suggest a more recent nucleation of the extensional basins towards east. although the lack of outcropping deposits related to the first event cannot exclude that the deposits are buried within the basins, the significant extension of the area where these deposits cannot be detected corroborates the younger age of formation of the eastern basins. this evidence fosters the already published hypotheses on the eastward migration of the extensional tectonics during the quaternary which were not based, however, on a detailed view of the continental stratigraphy (e.g. lavecchia et al., 1994; cavinato and de celles, 1999; galadini et al., 2001). uncertainties can affect the proposed stratigraphic scheme as for the correlation of parts of the succession related to the transition from the second to the third unit. we cannot exclude, in this case, the existence of minor depositional events different from those represented in our stratigraphic scheme. similar uncertainties may affect the upper part of the fourth unit. the main unsolved issue is the age of the first depositional event, since available chronological constraints are vague. our conjecturing indicates a long time interval between this event and the second one, but cannot quantify the length of the time span. on this basis, although a deposition mainly related to the pliocene is probable, we cannot exclude that part of the sediments are related to the early pleistocene. the individuation of the method which may cast light on this fundamental issue is presently not easy. indeed, the future discovery of paleontological findings is improbable, since nothing has been found until now, although the thickness of the outcropping deposits is several hundred metres and a large number of outcrops have been investigated in the last thirty years. we believe, therefore, that only the investigations on the relationship between dated marine deposits on the tyrrhenian margin and intra-apennine continental deposits (in the few places where a lateral transition can be detected) will produce reliable data to precisely define the age of the first depositional event. aacckknnoowwlleeddggeemmeennttss this work has been partially financed by the program cnr agenzia 2000 "strutture attive nel sistema orogenico appenninico: caratterizzazione geomorfologica, geologico-strutturale, sismogenetica e geodetica". the remains of hippopotamus antiquus desmarest have been investigated by c. petronio, r. sardella, e. dicanzio (university of rome "la sapienza"), c. gazzetti (tecnostudi ambiente s.r.l., rome) and by the authors of the present paper. the work has benefited from the discussion which, during the 90s, has involved the authors and numerous quaternary geologists and geomorphologists. for this reason we are particularly grateful to c. bartolini (university of firenze), f. carraro (university of torino), a. cinque (university of napoli) and f. dramis (university of roma tre). the authors' opinion about the morpho-stratigraphic issue may not be (and probably is not) the same of the mentioned researchers. a. cittadini (cnr, istituto di geologia ambientale e geoingegneria) gave technical support during many of the geological surveys we made during the last 15 years. rreeffeerreenncceess aa.vv., 1986 carta geologica del parco nazionale d'abruzzo. ente autonomo parco naz. abruzzo, roma. azzaroli a., 1983 quaternary mammals and the "endvillafranchian" dispersal event a turning point in the history of eurasia. palaeogeography, palaeoclimatology, palaeoecology, 4444, 117-139. accordi g., 1975 nuovi affioramenti di lacustre sollevato a terrazzi al bordo settentrionale del fucino (abruzzi). boll soc. natur. in napoli, 8844, 1-16. bagnaia r., d'epifanio a. & sylos labini s., 1989 aquila and subequan basins: an example of quaternary evolution in central apennines. quat. nova, spec. number 11, 1-23. barberi r., cavinato g.p., gliozzi e. & mazzini i., 1995 late pliocene-early pleistocene palaeoenvironmental evolution of the rieti basin (central apennines). il quaternario, 88, 515-534. barberi r., esposito g., miccadei e. & piacentini t., 2001 elementi geomorfologici quaternari della valle del sagittario. geoitalia, 3rd forum fist, abstract volume, 103-104. barbieri m., barbieri m., castorina f., d'orefice m., giardini g., graciotti r. & trudu c., 1996 le vulcaniti del bosco di oricola (l'aquila): caratteristiche geolitologiche, petrostrutturali ed isotopiche. miner. petrogr. acta, 3399, 125-133. barbieri m., barbieri m., d'orefice m., graciotti r. & stoppa f., in press il vulcanismo monogenico medio-pleistocenico della conca di carsoli (l'aquila). geologica romana. basili r., bosi c. & messina p., 1999 paleo-landsurfaces and tectonics in the upper aterno valley (central apennines). z. geomorph. n.f., suppl. bd. 111188, 17-25. beneo e., 1939 le terrazze quaternarie della regione fucense ed i loro rapporti con i fenomeni orogenetici della marsica (appennino abruzzese). boll. soc. geol. it., 5588, 77-104. bertini t. & bosi c., 1976 sedimenti continentali probabilmente pliocenici nella valle del salto e nella conca del fucino (rieti e l'aquila). boll. soc. 73plio-quaternary continental deposits ... geol. it., 9955, 767-801. bertini t. & bosi c., 1993 la tettonica quaternaria della conca di fossa (l'aquila). il quaternario 66, 293-314. bertini t., bosi c., messina p. & sposato a., 1986 elementi di tettonica compressiva pliocenica nella zona di borgo s. pietro (rieti). mem. soc. geol. it. 3355, 547-553. bertini t., bosi c., galadini f., 1989 la conca di fossa-s. demetrio dei vestini. in: c.n.r., centro di studio per la geologia tecnica & enea, p.a.s.: "elementi di tettonica pliocenico-quaternaria ed indizi di sismicità olocenica nell'appennino lazialeabruzzese", soc. geol. it., 26-58. blumetti a. m., dramis f. & michetti a.m. 1993 faultgenerated mountain fronts in the central apennines (central italy): geomorphological features and seismotectonic implications. earth surf. proc. and land., 1188, 203-223. blumetti a.m., cavinato g.p. & tallini m., 1996 evoluzione plio-quaternaria della conca di l'aquila-scoppito: studio preliminare. i l quaternario, 99, 281-286. blumetti a.m., coltorti m., dramis f., ferreli l., michetti a.m., petronio c., pieruccini p. & sardella r., 1997 segnalazione di equus cf. altidens nei depositi terrazzati della valle del fiume giovenco (l'aquila) ed implicazioni per la tettonica e la stratigrafia quaternaria del bacino del fucino. geoitalia, 1st forum fist, abstract volume, 219-221. bosi c., 1989 tentativo di correlazione fra le successioni plio-pleistoceniche. in: c.n.r., centro di studio per la geologia tecnica & enea, p.a.s.: "elementi di tettonica pliocenico-quaternaria ed indizi di sismicità olocenica nell'appennino lazialeabruzzese", soc. geol. it., rome, pp. 97-104. bosi c. & bertini t., 1970 geologia della media valle dell'aterno. mem. soc. geol. it., 99, 719-777. bosi c. & messina p., 1990 elementi di stratigrafia neogenico-quaternaria tra il fucino e la valle del giovenco (l'aquila). memorie descrittive della carta geologica d'italia 3388, 85-96. bosi c. & locardi e., 1991 vulcanismo meso-pleistocenico nell'appennino laziale-abruzzese. studi geol. cam., special volume 11999911//22, 319-325. bosi c. & messina p., 1991. ipotesi di correlazione fra successioni morfo-litostratigrafiche plio-pleistoceniche nell'appennino laziale-abruzzese. studi geol. cam., special volume 11999911//22, 257-263. bosi c., messina p. & sposato a., 1989 la depressione del salto. in: c.n.r., centro di studio per la geologia tecnica & enea, p.a.s.: "elementi di tettonica pliocenico-quaternaria ed indizi di sismicità olocenica nell'appennino laziale-abruzzese", soc. geol. it., rome, pp. 89-96. bosi c., galadini f. & messina p., 1995 stratigrafia plio-pleistocenica della conca del fucino. il quaternario, 88, 83-94. bosi c., galadini f. & messina p., 1999 stratigrafia ed evoluzione geologica plio-pleistocenica della conca del fucino. in: s. castenetto, f. galadini (eds.), "13 gennaio 1915, il terremoto nella marsica". servizio sismico nazionale and c.n.r. istituto di ricerca sulla tettonica recente, rome, 171-181. cacciuni a., centamore e., di stefano r. & dramis f., 1995. evoluzione morfotettonica della conca di amatrice. studi geol. cam., spec. vol. 11999955//22, 95-100 carrara c., frezzotti m. & giraudi c., 1995 stratigrafia plio-quaternaria. in: carrara c. (ed.), "lazio meridionale, sintesi delle ricerche geologiche multidisciplinari", enea dipartimento ambiente, 62-85. cavinato g.p., 1993 recent tectonic evolution of the quaternary deposits of the rieti basin (central apennines, italy): southern part. geol. rom., 2299, 411-434. cavinato g.p. & miccadei e., 1995 sintesi preliminare delle caratteristiche tettoniche e sedimentarie dei depositi quaternary della conca di sulmona (l’aquila). il quaternario, 88, 129-140. cavinato g.p. & de celles p.g., 1999 extensional basins in the tectonically bimodal central apennines fold-thrust belt, italy: response to corner flow above a subducting slab in retrograde motion. geology 2277, 955-958. cavinato g.p. & miccadei e., 2000 pleistocene carbonate lacustrine deposits: sulmona basin (central apennines, italy). in: gierlowski-kordesh e. h. and kelts k. r. (eds.), "lake basins through space and time". aapg studies in geology 4466, 517-526. cavinato g. p., cerisola r. & storoni ridolfi s., 1989 segnalazione del ritrovamento di denti di equus stenonis (cocchi) in località s. rufina (conca di rieti lazio). geol. rom., 2266, 255-257. cavinato g.p., cosentino d., de rita d., funiciello r. & parotto m., 1994 tectonic-sedimentary evolution of intrapenninic basins and correlation with the volcano-tectonic activity in central italy. mem. descr. carta geol. d'it., 4499, 63-76. cavinato g.p., gliozzi e. & mazzini i., 2000 two lacustrine episodes during the late pliocene-holocene evolution of the rieti basin (central apennines, italy). in: gierlowski-kordesh e. h. and kelts k. r. (eds.), "lake basins through space and time". aapg studies in geology 4466, 527-534. cavinato g.p., carusi c., dall'asta m., miccadei e. & piacentini t., 2002 sedimentary and tectonic evolution of plio-pleistocene alluvial and lacustrine deposits of fucino basin (central italy). sed. geol., 114488, 29-59. ciccacci s., d'alessandro l., dramis f. & miccadei e., 1999 geomorphologic evolution and neotectonics of the sulmona intrmaontane basin (abruzzi apennine, central italy). z. geomorph. n.f., suppl. bd. 111188, 27-40. cipollari p., cosentino d. & gliozzi e., 1999 extensionand compression-related basins in central italy during the messinian lago-mare event. tectonophysics 315, 163-185. cnr-pfg, 1987 neotectonic map of italy. quaderni de la ricerca scientifica, 114. colacicchi r., 1967 geologia della marsica orientale. geol. rom., 66, 189-316. d'agostino n., funiciello r., speranza f. & tozzi m., 1994 caratteri della tettonica distensiva nell'appennino centrale: l'area di s. stefano sessanio-calascio (l'aquila). boll. soc. geol. it., 111133, 37-53. d'agostino n., speranza f. & funiciello r., 1997 le "brecce mortadella" dell'appennino centrale: primi 74 c. bosi et al. risultati di stratigrafia magnetica. il quaternario 1100, 385-388. demangeot j., 1965 géomorphologie des abruzzes adriatiques. centre recherche et documentation cartographiques, memoires et documents, paris, 403 pp. devoto g., 1965 lacustrine pleistocene in the lower liri valley (southern latium). geol. rom., 44, 291-368. devoto g., 1967 le brecce calcaree mioceniche nella alta valle roveto, fra castellafiume e canistro (frosinone, lazio meridionale). geol. rom., 66, 75-86. di bucci d., mazzoli s., in press active tectonics of the northern apennines and adria geodynamics: new data and a discussion. j. geodynamics. doglioni c., 1991 a proposal for the kinematic modelling of w-dipping subductions possible applications to the tyrrhenian-apennines system. terra nova, 33, 423-434. faccenna c., davy p., brun j.p., funiciello r., giardini d., mattei m. & nalpas t. 1996 the dynamic of back-arc basins: an experimental approach to the opening of the tyrrhenian sea. geoph. journ. int., 112266, 781-795 fornaseri m., 1985 geochronology of volcanic rocks from latium (italy). rend. soc. it. min. petr., 4400, 73-106. galadini f., 1999 pleistocene change in the central apennine fault kinematics, a key to decipher active tectonics in central italy. tectonics, 1188, 877-894. galadini f. & messina p., 1990 osservazioni su un deposito a blocchi al margine sw della conca di pescasseroli (italia centrale). il quaternario, 33, 23-30. galadini f. & giuliani r., 1991 pleistocene deformational history of the barisciano-calascio area, ne margin of the middle aterno river valley (central italy). boll. serv. geol. d'it., 111100, 169-180. galadini f. & messina p., 1993a stratigrafia dei depositi continentali, tettonica ed evoluzione geologica quaternaria dell'alta valle del f. sangro (abruzzo meridionale). boll. soc. geol. it., 111122, 877-892. galadini f. & messina p., 1993b characterization of the recent tectonics of the upper sangro river valley (abruzzi apennine, central italy). annali di geofisica, 3366, 277-285. galadini f. & messina p., 1994 plio-quaternary tectonics of the fucino basin and surroundings areas (central italy). giornale di geologia, 5566, 73-99. galadini f. & galli p., 1999 the holocene paleoearthquakes on the 1915 avezzano earthquake faults (central italy): implications for active tectonic in the central apennines. tectonophysics, 330088, 143-170. galadini f. & messina p., 2001 plio-quaternary changes of the normal fault architecture in the central apennines (italy). geodinamica acta, 1144, 321-344. galadini f., giraudi c. & messina p., 1998 nuovi dati sulla tettonica tardopleistocenica dell’alta valle del sangro: implicazioni sismotettoniche. il quaternario, 1111, 347-356. galadini f., bosi c., giaccio b., messina p. & sposato a., 2001 geomorphological constraints for the pliocene-middle pleistocene uplift/faulting history of the abruzzi apennines (central italy). workshop "uplift and erosion: driving processes and resulting landforms", certosa di pontignano (siena), september 20/21, 2001, volume of the abstracts, 41. galadini f., messina p., giaccio b. & sposato a., 2003 early uplift history of the abruzzi apennines (central italy): available geomorphological constraints. quaternary international, 110011//110022, 125-135. ghisetti f., & vezzani l., 1999 depth and modes of pliocene-pleistocene crustal extension of the apennines (italy). terra nova, 1111, 67-72 giraudi c., 1994 elementi di geologia del quaternario della piana di campo imperatore (gran sasso d'italia). atti tic. sc. terra, spec. ser., 22, 137-143. giraudi c., 1995 sedimenti eolici, variazioni climatiche ed influenza antropica: considerazioni su alcune piane intermontane dell'appennino abruzzese. il quaternario, 88, 211-216. giraudi c., 1996 l’impronta del “younger dryas” degli “heinrich events” nell’evoluzione climatica e ambientale dell’italia centrale. il quaternario, 99, 533-540. giraudi c., 1998 late pleistocene and holocene lake level variations in fucino lake (abruzzo central italy) inferred from geological, archaeological and historical data. in: esf workshop palaeohydrology as reflected in lake-level changes as climatic evidence for holocene times, paläoklimaforschung, 2255, 1-17. giraudi c. & frezzotti m., 1997 late pleistocene glacial events in the central apennines, italy. quat. res., 4488,, 280-290. giuliani r. & sposato a., 1995 evoluzione quaternaria del sistema di depressioni del tirino (appennino abruzzese). il quaternario, 88, 217-228. jolivet l., faccenna c., d'agostino n., fournier m. & worrall d., 1999 the kinematics of back-arc basins, examples from the tyrrhenian, aegean and japan seas. in: c. mcniocaill and p.d. ryan (eds.), "continental tectonics". geol soc. london spec. publ. 116644, pp. 21-53 lavecchia g., brozzetti f., barchi m., menichetti m. & keller j.v.a., 1994 seismotectonic zoning in east-central italy deduced from an analysis of the neogene to present deformations and related stress fields. geol. soc. of am. bull., 110066, 11071120 maini p.s., 1956 sopra una zanna di elephas antiquus italicus rinvenuta a sant'eusanio forconese. annali "s. chiara", reale monastero s.chiara, napoli, 66.. malinverno a. & ryan w.b.f., 1986 extension in the tyrrhenian sea and shortening in the apennines as result of arc migration driven by sinking of the lithosphere. tectonics, 55,, 227-245 mariotti, g. & capotorti f., 1988 analisi ed interpretazione di alcuni elementi tettonici recenti nella media valle del salto (rieti). rend. soc. geol. it., 1111, 79-84. meletti c., patacca e. & scandone p., 1995 il sistema compressione-distensione in appennino. in: bonardi g., de vivo b., gasparini p., vallario a. (eds.), "cinquanta anni di attività didattica e scientifica del prof. felice ippolito", bologna, 361-370. melchiorri f., 1987 evoluzione geologica plio-pleistocenica della medio-alta valle del turano. unpublished thesis, university of rome "la sapienza", 191 pp. messina p., 1996 tettonica mesopleistocenica dei ter75plio-quaternary continental deposits ... razzi nord-orientali del fucino (italia centrale). il quaternario, 99, 293-298. messina p., moro m. & speranza f., 2001 primi risultati di stratigrafia magnetica su alcune formazioni continentali dell'alta valle dell'aterno (italia centrale). il quaternario, 1144,, 116677--117722.. miccadei e., cavinato g.p. & vittori e., 1992 elementi neotettonici della conca di sulmona. studi geol. cam., spec. vol. 1992/1, 165-174. miccadei e., barberi r. & de caterini g., 1997 nuovi dati geologici sui depositi quaternari della conca subaequana (appennino abruzzese). il quaternario, 1100, 485-488. miccadei e., barberi r. & cavinato g.p., 1998a la geologia quaternaria della conca di sulmona (abruzzo, italia centrale). geol. rom., 3344, 59-86. miccadei e., parotto m., rossi s. & zambianchi p.a., 1998b carta geologica dell'area m. rotella-m. pizzalto-m. porrara (abruzzo, appennino centrale). tipografia s.g.s., roma. miccadei e., barberi r., lauducci a. & piacentini t., 2001 elementi geomorfologici quaternari dell'altopiano delle cinquemiglia (aq, abruzzo). geoitalia, 3rd forum fist, abstract volume, 118-119. narcisi b. & sposato a., 1989 elementi di cronologia dell'attività vulcanica. in: c.n.r., centro di studio per la geologia tecnica & enea, p.a.s.: "elementi di tettonica pliocenico-quaternaria ed indizi di sismicità olocenica nell'appennino lazialeabruzzese", soc. geol. it., 20-23. nijman w., 1971 tectonics of the velino-sirente area, abruzzi, central italy. koninkl. nederl. akademie van wetenschappen, series b, 7744, 156-184. pace b., boncio p. & lavecchia g., 2002 the 1984 abruzzo earthquake (italy): an example of seismogenic process controlled by interaction between differently oriented synkinematic faults. tectonophysics, 335500, 237-254. pantosti d., d'addezio g., cinti f.r., 1996 paleoseismicity of the ovindoli-pezza fault, central apennines, italy: a history including a large, previously unrecorded earthquake in the middle ages (8601300 a.d.). j. geophys. res., 110011,, 5937-5959 patacca e., sartori r., scandone p., 1990 tyrrhenian basin and apenninic arcs: kinematic relations since late tortonian times. mem. soc. geol. it., 4455, 425-451 raffy j., 1970 étude géomorphologique du bassin d'avezzano (italie centrale). méditerranée, 11, 3-19. raffy j., 1983 le versant tyrrhenien de l'apennin central. étude géomorphologique. thèse présentée devant l'université de paris sorbonne, 6 juin 1979, 442 pp. royden l., patacca e. & scandone p., 1987 segmentation and configuration of subducted lithosphere in italy: an important control on thrustbelt and foredeep-basin evolution. geology, 1155,, 714-717. sylos labini s., bagnaia r. & d'epifanio a., 1993 il quaternario del bacino di sulmona (ital ia centrale). quaternaria nova, 3, 343-360. vittori e., cavinato g.p. & miccadei e., 1995 active faulting along the northeastern edge of the sulmona basin, central apennines, italy. in: serva l. and slemmons d. b. (eds.), "perspectives in paleoseismology". ass. of eng. geologists, spec. publ. no. 66, 83-100. working group cpti, 1999 catalogo parametrico dei terremoti italiani. ing, gndt, sga ssn, bologna, 92 pp. zarlenga f., 1987. i depositi continentali del bacino del fucino (l'aquila, italia centrale). geol. rom. 2266, 223-253. 76 c. bosi et al. imp.ravazzi aann oovveerrvviieeww ooff tthhee qquuaatteerrnnaarryy ccoonnttiinneennttaall ssttrraattiiggrraapphhiicc uunniittss bbaasseedd oonn bbiioollooggiiccaall aanndd cclliimmaattiicc eevveennttss iinn iittaallyy cceessaarree rraavvaazzzzii c.n.r. istituto per la dinamica dei processi ambientali, milano (e-mail: cesare.ravazzi@idpa.cnr.it) abstract a short review about quaternary continental stratigraphic units based on biological and climatic events is provided, with several examples taken from italy. the potential of biochronological and biostratigraphical units is discussed. the suitability of climate events and of composite regional units in continental stratigraphy is also stressed, although a consistent definition and formal status of the latter units are not yet available. riassunto le unità stratigrafiche basate su eventi biologici e climatici sono di largo uso nel quaternario continentale, ma il loro status non è ben definito da accordi internazionali. nel presente lavoro si evidenzia il significato e l’utilità delle unità biocronologiche, biostratigrafiche, climatostratigrafiche e cronostratigrafiche e si auspica che venga mantenuta una rigorosa distinzione nel loro impiego, prendendo spunto da vari esempi in italia. viene posto l’accento sull’indipendenza delle unità biocronologiche continentali dalle biozone stratigrafiche. queste ultime sono applicabili alla distribuzione stratigrafica di microfossili (polline, diatomee) e di piccoli invertebrati, ma non è il caso dei grossi mammiferi. le unità climatostratigrafiche riguardano sia eventi a scala globale, sia regionale o locale; in ogni caso sono diacroniche e non danno luogo a correlazioni di significato strettamente cronostratigrafico. la mancanza di una chiara distinzione tra unità biostratigrafiche e climatostratigrafiche ha creato confusione nella terminologia riguardante la parte terminale del pleistocene superiore e dell’olocene. il significato delle unità in uso in questo intervallo viene discusso in un’apposita tabella. viene infine considerata la natura composita di alcune unità in uso nel quaternario continentale a scala regionale in europa occidentale, le quali risultano dalla combinazione di tutti i dati disponibili di interesse stratigrafico e cronologico. l’impiego con un significato cronostratigrafico di tali unità non dovrebbe essere confuso con la loro natura e definizione. key words: quaternary biostratigraphy, biochronology, pollen zonation, climatostratigraphy. parole chiave: biostratigrafia, quaternario, biocronologia, zonazione pollinica, climatostratigrafia. il quaternario italian journal of quaternary sciences 1166(1bis), 2003, 11-18 11.. iinnttrroodduuccttiioonn reconstructing the quaternary stratigraphy in continental environments is a difficult task because of the low degree of succession continuity and of the scattered paleontological documentation. although biological and climatic events help understanding sedimentary sequences and mapped geological units, the usage of biochronology, biostratigraphy, climatostratigraphy and composite regional stratigraphy is still limited. this paper provides a brief review to the potential of these units, with several examples from italy. a late pleistocene and holocene chronoand climatostratigraphic subdivision of continental italy and part of europe is also presented. 22.. bbiioocchhrroonnoollooggyy,, bbiioocchhrroonnoossttrraattii-ggrraapphhyy aanndd bbiioossttrraattiiggrraapphhyy fossiliferous continental deposits formed in a regime of virtually continuous sedimentation can be found in deep lacustrine environments, but they record relatively short time periods (103 – 104 years) compared to marine successions. this obstacle may be partially overcome by applying biochronological criteria. biochronology is the subdivision of geological time by means of biological events, i.e. the evolution of the organisms with respect to time and other paleobiological events, which do not imply consideration of the stratigraphic relationships among the rocks in which the fossils are included (berggren & van couvering, 1978; raffi & serpagli, 1993, tab. 1). biochrons can be defined thanks to the theoretical base provided by irreversible organic evolution, and by other paleobiological events (e.g. immigration, dispersal, emigration, and extinction). however, often the continental faunal units used in italy miss a reference to any body of rocks, or, in other terms, body of rocks including faunal assemblages have been not preserved after the fossil collection. in these conditions, it may be impossible to describe biostratigraphic units, and only biochronologic or biochronostratigraphic unit can be conceived1 . the concepts of mammal continental biochronology were developed by lindsay and tedford (1990), fejfar & heinrich (1990) and walsh (1998). a quaternary biochronological scheme of the italian mammal and mollusc faunal complexes is well established (gliozzi et al., 1997; kotzakis, this issue). the interpretational approach provided by biochronology is also inherent the characterization of floristic com1 bbiioocchhrroonnoossttrraattiiggrraapphhiicc uunniittss are “the sets of rock formed during biochrons, without reference to any particular stratigraphic section” (walsh, 1998). bbiioossttrraattiiggrraapphhiicc uunniittss are instead “bodies of rock strata that are defined or characterized on the basis of their contained fossils” (ics, 1994, p. 53). 12 c. ravazzi table 1 the stratigraphic categories currently used in quaternary sciences. the table includes units formally defined in the international code of stratigraphy (salvador, 1994) and other categories that, despite not yet formally defined by ics, are of importance for quaternary stratigraphy and are of common usage. the relevant references (only for units not included in ics) are here reported: 1 cushing, 1967; birks & gordon, 1985; tzedakis, 1994; 2 kerney et al., 1980; 3 de giuli et al., 1986; 4 fejfar & heinrich, 1990; lindsay & tedford, 1990; walsh, 1998; 5 de giuli et al., 1983; 6 mai & walther, 1978; 7 lowe & walker, 1997; 8 walker et al., 1999; 9 johnson et al., 1997; 10 zagwijn, 1992. the term “composite regional units” is used to refer “regional stages” of the dutch stratigraphy. this terminological problem is discussed in the text. ssuummmmaarryy ooff ccaatteeggoorriieess uusseedd iinn tthhee ccoonnttiinneennttaall qquuaatteerrnnaarryy ssttrraattiiggrraapphhyy (non-referred units are from salvador, 1994) (*) mappable units; (+) stratotype sections applicable 11.. cchhrroonnoollooggyy 22.. rroocckk pprrooppeerrttiieess 33.. ffoossssiill ccoonntteenntt cchhrroonnoossttrraattiiggrraapphhyy ((**)) ((++)) lliitthhoossttrraattiiggrraapphhyy ((**)) ((++)) bbiioossttrraattiiggrraapphhyy ((++)) eonothem group pollen superzone1 erathem formation pollen zone system membre other biozones and ecozones2 series stratum (based on diatoms, stage cyanobacteria, green algae, substage ppeeddoossttrraattiiggrraapphhyy ((**)) ostracods, molluscs, etc.) chronozone mmiinneerraallooggyy ((**)) ((++)) bbiioocchhrroonnoossttrraattiiggrraapphhyy eeqquuiivvaalleenntt ggeeoocchhrroonnoollooggiicc uunniittss heavy mineral assemblages aanndd bbiioocchhrroonnoollooggyy eon mmaaggnneettoossttrraattiiggrraapphhyy ((++)) era (cenozoic) polarity zone biochronological events3 period (quaternary) land mammal ages4 epoch (pleistocene) iissoottooppiicc ssttrraattiiggrraapphhyy ((++)) faunal units5 age δ18o stages from sea records local faunas5 subage (mis = marine isotopic stages) floral complexes6 chron δ18o from polar ice (gs / gi) local floras6 termination human cultural chronology cchheemmiioossttrraattiiggrraapphhyy 44.. ccoommppoossiittee aanndd iinntteerrpprreettaattiioonnaall ssttrraattiiggrraapphhiicc ccaatteeggoorriieess ((oonnllyy 44..bb aanndd 44..ee aarree ddeettaaiilleedd hheerree)) 44..aa.. ccyycclloossttrraattiiggrraapphhyy ((**)) ((++)) 44..bb.. eevveenntt ddiiaacchhrroonniicc ssttrraattiiggrraapphhyy event (whittaker et al., 1991) bbaasseedd oonn cclliimmaattiicc eevveennttss iinnffeerrrreedd bbyy ssttrraattiiggrraapphhiicc ppaatttteerrnn [[cclliimmaattoossttrraattiiggrraapphhyy ((++))]] aanndd ootthheerr eevveennttss:: geologic-climatic (geoclimatic) units7 global interglacial, global glaciation7 stadial, interstadial episodes and sub-episodes (mostly at regional scale) gi/gs (greenland stadial / interstadial episodes and subepisodes)8 bbaasseedd oonn bboouunnddaarriieess ooff rreeffeerreenntt ddeeppoossiittss ffrroomm wwhheerree eevveennttss aarree iinnffeerrrreedd ((**)) rock diachronic event units9 episode subepisode phase 44..cc.. uunnccoonnffoorrmmiittyy bboouunnddeedd ssttrraattiiggrraapphhiicc uunniittss 44..dd.. sseeqquueennccee ssttrraattiiggrraapphhyy 44..ee.. rreeggiioonnaall ccoommppoossiittee ssttrraattiiggrraapphhyy ((**)) ((++)) ccoommppoossiittee rreeggiioonnaall ssttaaggee1100 a combination of the above mentioned properties (e.g. paleomagnetic polarity, lithostratigraphy, susceptibility log, radiometric dating, pollen stages succession, climatostratigraphic succession) considered at regional scale and boundary-defined. plexes, first defined in the lowlands of germany (mai & walther, 1978) and recently applied to the continental carpofloral assemblages of the western po plain (martinetto, 1995). considering the italian continental paleobiological record, only the distribution of some microfossil, e.g. pollen and diatoms, and of small invertebrates (ostracods, chironomids), matches the requirements to establish biostratigraphic units. there are only a few examples of continental biostratigraphy in italy. several paleoecological investigations have proposed a local biozonation, based on the succession of biotic assemblages at a single lacustrine or palustrine small basin. so far there is detailed local biozonation back to 14 kyr bp at the southern alpine foothill (schneider, 1978; wick, 1996), in central alps (tinner, 1998; pini, 2002), in the central ital ian peninsula (lowe, 1992; brugiapaglia & de beaulieu, 1995; lowe et al., 1996) and in central sicily (sadori & narcisi, 2001). the pollen zonation from the monticchio maar lake (southern apennines) and from the latium extends to the last 100 kyr bp (magri, 1999; magri & sadori, 1999; allen & huntley, 2000). one site is zoned back to about 250 kyr bp (valle di castiglione: follieri et al., 1988). detailed pollen zonation is also available for the middle pleistocene lacustrine record of vallo di diano (russo ermolli, 1994), from part of the early pleistocene lacustrine sequence of leffe in the lombardian pre-alps (ravazzi & rossignol strick, 1995; ravazzi & moscariello, 1998) and from the late early pleistocene colle curti and cesi basin sequence (bertini, 2000). the development of regional pollen zones applies to biogeographically homogeneous regions, which are provided with several pollen records. although each site is characterized by a peculiar vegetation development (shown by the succession of local pollen zones spanning an entire warm or cold phase: this is the concept of pollen assemblage superzone, proposed by tzedakis, 1994), a comparative inspection of pollen curves shows that different sites have in common a similar background pollen, after eliminating local plants from the pollen sum. this is the case of latium maar lakes, where the main changes observed in the five long pollen records available have been correlated (follieri et al., 1989). a quantitative analysis by numerical methods (sugita 1994) can help defining the biogeographical limits of a regional pollen zone. regional pollen zones are commonly time-transgressive (lowe & walker, 1997); this is partially due to migration time lags (102 kilometers per 103 years). however, once the migration pattern is known and well dated, the time of immigration and / or expansion at a given site by a good pollen producer may be a precise biostratigraphic marker (e.g. the holocene migration history of picea, ravazzi, 2002). 33.. eevveenntt ssttrraattiiggrraapphhyy aanndd cclliimmaattoossttrraattiiggrraapphhyy climatostratigraphy (the modern development of geoclimatic stratigraphy) is a type of “event diachronic” stratigraphy based on interpreted climate features from evidence in the rock/sediment record (see lowe & walker, 1997). events are short-term phenomena that leave some trace in the geological record (e.g. volcanic eruptions, sea level changes, etc.). as noted by walker et al. (1999), "it is primarily the events and not the boundaries between the events that are specifically designated" (by climatostratigraphic inferences). furthermore, climatostratigraphy "acknowledges the fact that the stratigraphic boundaries marking the onset and ending of a climatic event may well be diachronous (.....)". climatostratigraphic units are best derived by a combi13an overview of the quaternary ... nation of different stratigraphical categories, such as lithological, biological, isotopic (walker et al., 1999), and ubsu units used in sequence stratigraphy (miall, 1997). whenever emphasis is on globally recognized climatic-events, climatostratigraphic subdivisions may concern the whole earth, such as global glaciations, interglacials and the interglacial-glacial cycle. local climatostratigraphic units may represent events recorded by relevant deposits, for instance at the scale of a basin catchment (e.g. high-intensity rain triggering catastrophic floods), or of a climatic province (e.g. lake level changes, etc.), or of a whole mountain chain (e.g. local glaciation). climatic events which occurred at regional scale, together with other derivate types of event stratigraphic units, such as volcanic eruptions, are widely used in italy (narcisi & vezzoli, 1999) and provide a powerful method for marine / continental correlations. for instance, the beginning of the late glacial interstadial (tab. 2) has been recognized in maar deposits from the italian peninsula as well as in marine sediments from the adriatic sea. inter-regional and marine / continental correlation has been possible thanks to the background arboreal pollen signal, which shows an abrupt shift at 12.4 ka 14c bp (lowe et al., 1996). this pollen signal has been compared with other paleoclimatic proxies (geochemistry, rock-magnetism, isotopes, diatoms, other algae, invertebrate fossil remains), for a multidisciplinary evaluation of the climatic event triggering the observed physical and biological changes (guilizzoni & oldfield, 1996). the climatic events are commonly very close to the boundaries of the biostratigraphic subdivisions from where events are inferred. the international stratigraphic guide (salvador, 1994) misses to consider climatostratigraphy as a basic stratigraphic category of common use. the present author believes that a rigorous distinction between biostratigraphic and climatostratigraphic units needs to be maintained (on this problem see turner, 2002 discussing the status of the eemian interglacial). an effort to add precision to the terminology used in different branches of stratigraphy is made in tab. 2 and 3. 44.. ccoommppoossiittee rreeggiioonnaall uunniittss several quaternary stratigraphers from central europe acknowledges the use of continental “stages” (gibbard et al., 1991; zagwijn, 1998). from the paleoclimatological point of view, some of them are “complex stages” (zagwijn, 1992, p. 585). these units (tab. 1b) derive from a combination of all available stratigraphic (lithologic, ubsu, magnetic, biologic and climatic) and chronological (geocronometric, biochronological) data. the paleoclimatic complexity of such units is not the only defining characteristics, and therefore i would suggest to refer them as composite regional units. because they are based on diachronic-type stratigraphic units (such as climatoor biostratigraphic units) they are not chronostratigraphic units (not a stage by definition). however, composite regional units are also intended to provide a chronostratigraphical reference for biogeographically circumstancied regions, hence the term “stage” (which implies a chronostratigraphic unit) has been used with reference to rocks formed during the relevant time interval (gibbard et al., 1991; zagwijn, 14 c. ravazzi tab. 2 framework of late pleistocene chronologic and climatostratigraphic reference units used in western-central europe (column climatostratigraphy dealing with the alps only) and detail of local units applicable to selected regions. algm = alpine last glacial maximum. the age of northern germany and netherlands interstadials (oerel, glinde, moershoofd, hengelo and denekamp) is from behre & van der plicht (1992), calibrated with the method by bard et al. (1998). alpine deglaciation and the late-glacial interstadial may be partially coeval. the term neoglaciation is from porter & denton (1967). 1992). the usage of a composite regional stratigraphy in continental regions is not formalized by the international stratigraphic code currently in use (salvador, 1994), and its chronostratigraphic value is stil l a matter of debate (gibbard & west, 2000). composite regional units are also characterized by a 15an overview of the quaternary ... tab. 3 late glacial and holocene chronostratigraphy / geochronology and climatostratigraphic units (from orombelli & ravazzi, 1996, modified and updated). chronozones are framed by conventional 14c ages bp. the late glacial is subdivided by using climatostratigraphic criteria. this is because the late glacial is characterized by sharp climatic changes which have been recognized either in terrestrial biological records, either in ice and in marine records, but these climatostratigraphic transitions do not fit the boundaries of the relevant chronozones proposed by mangerud et al. (1974). consequently, these late glacial chronozones miss any practical interest. holocene chronozones are provisory maintained here, waiting for further international agreements. note that the last glacial maximum in the italian alps ends about 15 ka 14c bp, well before than in central and northern europe. the earliest interval of the alpine late glacial, or, in other terms, the time interval between the beginning of the alpine deglaciation and the late glacial interstadial is poorly defined in stratigraphic terms. (* 1) the subdivisions early, middle and late holocene are informal, with boundaries at ca 7000 and 3000 bp. (* 2) the calendar 14c age bp has been calibrated with the program calib 4.0 elaborated by stuiver and reimer (1998). the calibrated ages are reported as one sigma time intervals obtained using a standard deviation of ± 50 yr on the conventional age. (* 3) the framing of the “holocene thermal optimum” between about 9 and 5 kyr 14c bp is based on: i) the δ18o curve from the renland ice core (larsen et al., 1995); ii) the record of alpine glacier contraction during the early-middle holocene (hormes et al., 2001); iii) the paleoecological record of treeline oscillation in the alps (wick & tinner, 1997). this concept of the holocene thermal optimum is different from the hypsithermal (porter, 1981), used in a previous version of this scheme (orombelli & ravazzi, 1996). (* 4) the younger dryas is here taken as a climatostratigraphic unit. l.i.a. = little ice age. dashed lines indicate large-scale diachronic boundaries. (* 5) a substantial increase of climatic humidity in the alps does not fit this boreal / atlantic chronozone boundary but occurred later, about 7.3 ka 14c bp, i.e. about 8.2 ka cal bp (tinner & lotter, 2001; pini, 2002). stratotype. for instance, an eemian stratotype was provided by van der heide and zagwijn (1967); see turner (2002), for a review. moreover, reference sections and boundaries or boreholes may be designated, such as the amsterdam borehole for the eemian (van leeuwen et al., 2000). the designation of stratotypes and / or reference sections for continental units is mentioned by the international stratigraphic code currently in use (ics, 1994, p. 77). the present author believes reference sections to be necessary for any further study. this procedure is expecially fruitful in case that bioprovinces are partially cohincident with sedimentary basins, a situation which may apply to the quaternary evolution of the apenninic intermontane basins and of the po plain. 16 c. ravazzi unfortunately, so far there are no proposals for composite regional units in italy. 55.. ccoonncclluussiioonn a consistent definition and formal status of continental stratigraphic units based on biological and climatic events is not yet available in the official agreements of iugs and inqua. this paper has emphasized the importance to maintain rigorous distinction among biochronologic, biostratigraphic, climatostratigraphic and chronostratigraphic units. the marked geological, environmental and climatic diversity affecting both the alpine and the mediterranean regions hampers correlation based on biological and climatic events. hope is placed in a multidisciplinary characterization of bioprovinces and of their relation to the major sedimentary archives of past environmental change. aacckknnoowwlleeddggeemmeennttss the comments by remo bertoldi (univ. of parma), maria rita palombo (univ. la sapienza, rome), benedetto sala (univ. of ferrara), danilo torre (univ. of firenze) and charles turner (open university, uk) helped to improve an earlier version of the manuscript. however, the author is the only responsible for the present paper. rreeffeerreenncceess allen j.r.m. & huntley b., 2000 weichselian palynological records from southern europe: correlation and chronology. quat. int., 7733//7744, 111-125. bard e., arnold m., hamelin b., tisnerat-laborde n., cabioch g., 1998 radiocarbon calibration by means of mass spectrometric 230th/234u and 14c ages of corals: an updated database including samples from barbados, mururoa and tahiti. radiocarbon, 40 (3), 1085-1092. behre k.-e. & van der plicht j., 1992 towards an absolute chronology for the last glacial period in europe: radiocarbon dates from oerel, northern germany. veget hist archaeobot, 11, 111-117. berggren w.a. & van couvering j.a., 1978 biochronology. in: cohee g.v., m.f. glaessner, & h.d. hedberg (eds.), contribution to the geologic time scale. american association of petroleum geologists bulletin, 5500, 1487-1500. bertini a., 2000 pollen record from colle curti and cesi: early and middle pleistocene mammal sites in the umbro-marchean apennine mountains (central italy). journal quat. sci., 1155 (8), 825-840. birks h.j.b. & gordon a.d., 1985 numerical methods in quaternary pollen analysis. academic press, london. brugiapaglia e., de beaulieu j.l., 1995 etude de la dynamique végétale tardiglaciaire et holocène en italie centrale: le marais de colfiorito (ombrie). comptes rendu academie science paris, 332211, 617-622. de giuli c., ficcarelli g., mazza p., torre d., 1983 confronto tra successioni marine e continentali del pliocene e pleistocene inferiore in italia e nell'area mediterranea. boll. soc. paleont. ital., 2222 (3), 323328. fejfar o. & heinrich w.-d., 1990 muroid rodent biochronology of the neogene and quaternary in europe. in: lindsay e.h., fahlbusch v., mein p. (eds.) european neogene mammal chronology. plenum press, new york. pp. 91-117. follieri m., magri d., sadori l., 1988 250,000-year pollen record from valle di castiglione (roma). pollen et spores, 30 (3-4), 329-356. follieri m., giardini m., magri d., sadori l., 1989 palynostratigraphy of the last glacial period in the volcanic region of central italy. quat. int., 4477//4488, 3-20. gibbard p.l., west r.g., zagwijn w.h., balson p.s., burger a.w., funnell b.m., jeffery d.h., de jong j., van kolfschoten t., lister a.m., meijer t., norton p.e.p., preece r.c., rose j., stuart a.j., whiteman c.a., zalasiewicz j.a., 1991 early and early middle pleistocene correlations in the southern north sea basin. quaternary science reviews, 1100, 23-52. gibbard p.l. & west r.g., 2000 quaternary chronostratigraphy: the nomenclature of terrestrial sequences. boreas, 2299, 329-336. gliozzi, e., abbazzi, l., argenti, p., azzaroli, a., caloi, l., capasso barbato, l., di stefano, g., esu, d., ficcarelli, g., girotti, o., kotsakis, t., masini, f., mazza, p., mezzabotta, c., palombo, m.r., petronio, c., rook, l., sala, b., sardella, r., zanalda, e., torre, d., 1997 biochronology of selected mammals, molluscs and ostracods from the middle pliocene to the late pleistocene in italy. the state of the art. rivista italiana di paleontologia e stratigrafia, 110033 (3), 369-388. guil izzoni p. & oldfield f., guest eds. 1996 – palaeoenvironmental analysis of italian crater lake and adriatic sediments (paliclas). memorie istituto italiano idrobiologia, vol. 5555. 357 pp. hormes a., müller b.u., schlüchter c., 2001 the alps with little ice: evidence for eight holocene phases of reduced glacier extent in the central swiss alps. the holocene, 1111 (3), 255-265. johnson w.h., hansel a.k., bettis e.a., karrow p.f., larson g.j., lowell t.v., schneider a.f., 1997 late quaternary temporal and event classifications, great lakes region, north america. quat. res., 4477, 1-12. kerney m.p., preece r.c., turner c., 1980 molluscan and plant biostratigraphy of some late devensian and flandrian deposits, kent. philosophical transactions of the royal society of london, b229911, 1-43. larsen e. sejrup h.p., johnes s.j. and knudsen k.l., 1995 do greenland ice cores reflect nw european interglacial cl imate variations? quaternary research, 4433, 125-132. lindsay h., tedford r.h., 1990 – development and application of land mammal ages in north america and europa, and comparison. in: lindsay h., fahlbusch w. & mein p. (eds.): european neogene mammal chronology. plenum press, new york. pp. 601-624. lowe, j.j., 1992 lateglacial and early holocene lake sediments from the northern apennines, italy pollen stratigraphy and radiocarbon dating. boreas, 2211, 193-208. lowe j.j., accorsi c.a., bandini mazzanti m., bishop a., van der kaars s., forlani l., mercuri a.m., rivalenti c., watsno c., 1996 pollen stratigraphy of sediment sequences from lakes albano and nemi (near rome) and from the central adriatic, spanning the interval from oxygene isotope stage 2 to the present day. in: guilizzoni, p., oldfield, f. (eds.), palaeoenvironmental analysis of italian crater lake and adriatic sediments. memorie istituto italiano idrobiologia, 5555, 71-98. lowe j.j., walker m.j.c., 1997 reconstructing quaternary environments. ii ed. longman, london. 446 pp. magri d., 1999 late quaternary vegetation history at lagaccione near lago di bolsena (central italy). rev. palaeobot. palynol., 110066, 171-208. magri d., sadori l., 1999 late pleistocene pollen stratigraphy at lago di vico, central italy. veget hist archaeobot, 88, 247-260. mai d. & walther h., 1978 die floren der haselbacher serie im weisselster-becken (bezirk leipzig, ddr). abh. staatl. mus. min. geol. dresden, 2288, 1-200. mangerud j., anderson s.t., berglund b.e. and donner j., 1974. quaternary stratigraphy of norden, a proposal for terminology and classification. boreas, 33: 109-128. martinetto e., 1995 significato cronologico e paleoambientale dei macrofossili vegetali nell'inquadramento stratigrafico del 'villafranchiano' di alcuni settori del piemonte (italia nw). tesi di dottorato di ricerca, univ. di torino. miall a.d., 1997 the geology of stratigraphic sequences. springer, berlin. 421 pp. narcisi b. & vezzoli l., 1999 quaternary stratigraphy of distal tephra layers in the mediterranean an overview. global and planetary change, 2211, 3150. oldfield f., 1996 the paliclas project: synthesis and overview. in guilizzoni p. and oldfield f. (eds.): palaeoenvironmental analysis of italian crater lake and adriatic sediments. mem. ist. ital. idrobiol., 5555, 329-357. orombelli g. and ravazzi c., 1996 the late glacial and early holocene: chronology and paleoclimate. il quaternario italian journal of quaternary sciences, vol. 99 (2), 439-444. pini r., 2002 a high-resolution late-glacial holocene pollen diagram from pian di gembro (central alps, northern italy). vegetation history and archaeobotany, 1111, 251-262. porter s.c. 1981 glaciological evidence of holocene climatic change. in: climate and history (wigley t.m.l. et al., eds.), 148-179. cambridge university press, cambridge. porter & denton 1967 chronology of neoglaciation in the north american cordillera. american journal of science, 226655,, 177-210. raffi s. & serpagli e., 1993 introduzione alla paleontologia. utet, torino. ravazzi c., 2002 late quaternary history of spruce in southern europe. review of palaeobotany and palynology, 112200 (1-2), 131-177. ravazzi c., rossignol strick m., 1995 vegetation change in a climatic cycle of early pleistocene age in the leffe basin (northern italy). palaeogeography, palaeoclimatology, palaeoecology, 111177, 105122. ravazzi, c., and moscariello, a., 1998 sedimentation, palaeoenvironmental evolution and time duration of earliest pleistocene climatic cycles in the 24 56 m fm-core interval (leffe basin, northern italy). in (th. van kolfschoten and p. gibbard eds.): proceedings of the inqua-seqs symposium ‘the dawn of the quaternary’. mededelingen nederlands instituut voor toegepaste geowetenschappen, 6600, 467-490. russo ermolli e., 1994 analyse pollinique de la succession lacustre pleistocène du vallo di diano (campanie, italie). annales société géologique de belgique, 111177, 333-354. sadori l. & narcisi b., 2001 the postglacial record of environmental history from lago di pergusa, sicily. the holocene, 1111 (6), 655-671. salvador a., ed., 1994 international stratigraphic code. second ed. the geological society of america. schneider r., 1978 pollenanalytische untersuchungen zur kenntnis der spätund postglazialen vegetationsgeschichte am südrand der alpen zwischen turin und varese (italien). bot. jahrb., 110000, 26-109. stuiver m., reimer p.j., bard e., beck w.j., burr g.s., hughen k.a., kromer b., mc cormac g., van der plicht j., spurk m., 1998 intcal98 radiocarbon age calibration, 24,000-0 cal bp. radiocarbon, 4400 (3), 1041-1083. sugita s., 1994 pollen representation of vegetation in quaternary sediments. journal of ecology, 8822, 881-897. tinner w., 1998 quartärbotanische untersuchungen zur waldbrandökologie des sottoceneri (südschweiz). ph.d. thesis. university of bern. tinner w. & lotter a.f., 2001 central european vegetation response to abrupt climate change at 8.2 ka. geology, 2299 (6), 551-554. turner ch., 2002 formal status and vegetational development of the eemian interglacial in northwestern and southern europe. quat. res., 5588, 41-44. tzedakis p.c., 1994 hierachical biostratigraphical classification of lon pollen sequences. journal quaternary science, 99 (3), 257-259. van der heide s. & zagwijn, w.h., 1967 stratigraphical nomenclature of the quaternary deposits in the netherlands. mededelingen geologische stichting ns, 1188, 23-28. walker m.j.c., björck s., lowe j.j., cwynar l.c., johnsen s.j., knudsen k.l., wohlfarth b., intimate group, 1999 isotopic 'events' in the grip core: a stratotype for the late pleistocene. quat. sci. rev., 1188, 1143-1150. walsh s.l., 1998 fossil datum and paleobiological event terms, paleontostratigraphy, chronostratigraphy, and the definition of land mammal “age” 17an overview of the quaternary ... boundaries. journal of vertebrate paleontology, 1188 (1): 150-179. wick l., 1996 late-glacial and early-holocene palaeoenvironments in brianza, northern italy. italian journal of quaternary sciences, 99 (2), 653659. wick l. & tinner w. 1997 vegetation changes and timberline fluctuations in the central alps as indicators of holocene climatic oscillations. arctic and alpine research, 2299 (4), 445-458. zagwijn w.h., 1992 the beginning of the ice age in europe and its major subdivisions. quaternary science reviews, 1111, 583-591. zagwijn w.h., 1998 borders and boundaries: a century of stratigraphical research in the tegelen – reuver area of limburg (the netherlands). mededelingen nederlands instituut toegepaste geowetenschappen, 6600, 19-34. 18 c. ravazzi relationship between micromorphological characteristics and engineering parameters of caliche (calcrete) i̇smail dinçer1*, altay acar1 & donatello magaldï2 1çukurova university, engineering and architecture faculty, geological engineering department, balcalı, 01330, adana, turkey 2university of l’aquila, engineering faculty, department of structures, water and soil engineering, monteluco di roio, 67040, l’aquila, italy *corresponding author: i̇smail dinçer department of geology engineering, faculty of engineering-architecture çukurova university 01330 adana, turkey fax: 90-322-3386126 tel: 90-322-3386715/15 e-mail: idincer@mail.cu.edu.tr abstract: i̇. dinçer, a. acar & d. magaldi, relationship between micromorphological characteristics and engineering parameters of caliche (calcrete). (it issn 0394-3356, 2007). caliches are described as secondary carbonate formations and calcareous, semiconsolidated aragonite or early diagenetic calcite forming in loose materials such as pebble, sand, silt, and soil under semi-arid and arid climatic regimes. the aim of this study is to identify and discuss effects of micro-morphological-mineralogical properties on engineering properties of caliche. furthermore, correlations derived from mechanical, physical-index properties and micromorphological characteristics are evaluated and establish statistically predictable model for ucs. for this aim, samples were taken from different locations in caliche outcrops occurring in the southern part of turkey. based on the statistical analyses, linear relationships were fitted between the micromorphological index (mi) and each mechanical and physical-index properties. based on these linear relationships among the engineering properties, uniaxial compressive strength, pwave velocity, average young’s modulus and point load index there are significant correlations with the micromorphological index (mi). results suggested that strength of the caliche is controlled by micromorphological properties. four micromorphological parameters which are effective on engineering properties of caliche were identified: microstructure, voids, coarse materials and matrix. microstructure is the most important parameter to assess engineering behaviour of caliche followed by voids, coarse materials and matrix. statistically most reliable models, which allow the estimating of ucs, are discussed in this study. the empirical equation, ucs = 7.137 + 3.06x10-3 vp + 0.38uw + 0.13mi where vp = p-wave velocity; and uw = unit weight is assumed to be the best and practical for engineering purposes. riassunto: i̇. dinçer, a. acar & d. magaldi, relazioni tra caratteristiche micromorfologiche e proprietà geotecniche della crosta calcarea (calcrete ). (it issn 0394-3356, 2007). la costa calcarea (caliche o calcrete in inglese) è un accumulo carbonatico indurito semiindurito costituito da calcite e/o aragonite che si forma entro substrati geologici sciolti come le ghiaie, le sabbie e i limi oppure entro suoli di clima in genere arido o semiarido. questa ricerca ha avuto come scopo l’identificazione e l’analisi delle relazioni esistenti tra le caratteristiche micromorfologiche e mineralogiche e le proprietà geotecniche della crosta calcarea affiorante nella turchia meridionale.al riguardo sono stati considerati modelli statistici di previsione della resistenza a compressione uniassiale (ucs) a partire dalle caratteristiche micromorfologiche.sono state inoltre trovate relazioni significative non soltanto per l’ucs ma anche per altri parametri geo-ingegneristici quali la velocità delle onde p entro i provini, il modulo di young e il valore risultante dalla prova di carico puntuale (point load test). questi risultati suggeriscono che le caratteristiche micromorfologiche e mineralogiche così come evidenziate dall’analisi in sezione sottile ed espresse da un indice micromorfologico (mi) , condizionano le proprietà meccaniche della crosta. le caratteristiche micromorfologiche che maggiormente appaiono influenzate da quelle micromorfologiche sono, nell’ordine, la microstruttura (micromass, secondo stoops, 2003), la tipologia dei vuoti, la tipologia dei costituenti grossolani, la matrice. l’equazione empirica che appare maggiormente valida per stimare la resistenza a compressione uniassiale, principale indice delle proprietà meccaniche di una roccia,è la seguente: ucs = 7.137 + 3.06x10-3 vp + 0.38uw + 0.13mi, dove vp = velocità delle onde p, uw= peso dell’unità di volume del materiale considerato e mi è il nuovo indice micromorfologico. keywords: caliche, micromorphological characteristics, mechanical properties, physical-index properties. parole chiave: caliche, caratteristiche micromorfologiche, proprietà meccaniche, proprietà geotecniche. il quaternario italian journal of quaternary sciences 20(2), 2007 137-150 1. introduction and background it is commonly accepted that engineering properties of the rocks are controlled by their petrographic characteristics. zorlu et al. (2004) concluded that packing density and packing proximity are most influencing in mechanical characteristics for sandstone. also they reported that texture is more important than mineralogy in this respect as far as sandstones were concerned. tugrul and zarif (1999) correlated the mechanical, physical-index properties with petrographical characteristics of granitic rocks. in the same way, they concluded that the influence of textural characteristics on the engineering properties appears to be more important than mineralogy. they also determined the types of contacts, grain (mineral) shape and size significantly influence the engineering properties of granitic rocks. koncagül and santi (1999) distinguished the factors affecting hardness, strength and durability in rocks in three different groups such as effective in grained rocks, argillaceous rocks and effective in both rock types. they concluded that packing density, degree of bonding, type of cement and bonding material, permeability, post-depositional factors, occurrence of 138 i̇. dinçer, a. acar & d. magaldi soft/soluble minerals and microfractures affect both uniaxial compressive strength (ucs) and the slake durability test (sdt) in a similar fashion. these factors cause both ucs and sdt results to increase or to decrease. jeng et al. (2004) found that porosity has more influence on the ucs than grain and matrix content does. at the same time, few researchers established a statistical model to predict mechanical properties of rocks using their petrographic characteristics (bell, 1978; fahy and guccione, 1979; shakoor and bonelli, 1991; ulusay et.al., 1994). caliche adversely affects cut slope stability, earth fill material sensitivity, and ground stability at structure sites along the motorway which is being constructed in the southern 3 turkey. about 90 % of active and potential slides in the region occur in the caliche deposits and colluvial deposits which have been derived mainly from caliche (yılmazer and smith, 1992). at the same time caliche widely formed foundations of buildings in the southern part of turkey and it was also used in the historical buildings as a dimension stone due to the ability to easily shape it. caliches are therefore very problematic materials for turkey. in this study, the relationship between micromorphological-mineralogical properties and rock index properties were examined for caliches. correlations derived from mechanical, physical-index properties and micromorphological characteristics were evaluated to establish a statistical prediction of ucs. 2. materials 2.1 the caliche thirteen samples were taken from different locations of caliche outcrops in the southern part of turkey (fig 1). caliche contains different levels for strength and deformability properties. however, only two levels were considered from a geotechnical point of view. the hardpan of the part shows rock properties whereas the soft pan at part below shows soil properties. block samples (approx. 0.25x0.25x0.20 m) collected from hardpan (massive caliche) has low strength level. the caliche formation is widely distributed in the region on peneplain morphology occurring from east to west in the adana region. caliches are described as a secondary calcium carbonate accumulation forming in loose materials such as gravel, sand, silt, and soil under semi-arid and arid climatic regimes. the caliche term was firstly used for the gravel and similar calcium carbonate cemented materials in south-western united states. some conditions which are required for the formation of caliche are country or basement rocks to be of a carbonate type, the occurrence of carbonate 4 in the soils, a semi-arid to arid climate and a widespread water percolation down the soil profile. in turkey, caliche occurrences are commonly observed in aegean, mediterranean, and central anatolia in young rock formations (atabey, et figure 1 location map of the study area. localizzazione della zona studiata. al., 1998). in southern of turkey, formation of massive caliche was attributed to pleistocene climatic fluctuations and a shallow lacustrine environment by kapur et al., (1993). the process is broadly similar to other sites around the mediterranean. 2.2 stratigraphic features of study area different tertiary aged lithostratigraphic units are outcropped in the study area. the tertiary stratigraphy was defined as pre-transgressive, transgressive and regressive deposits in succession (kapur et al., 1993). at the base of this succession, paleozoic and mesozoic aged lithostratigraphic units are outcropped (fig 2). cenozoic succession is mainly represented by tertiary and quaternary units. tertiary units unconformably overlap paleozoic and mesozoic rocks (yetis,, 1988). the transgressive deposits comprise the terrestrial and lacustrine formations (oligocene-lower miocene). the transgressive cycle of the miocene sea (burdigaliyenserravallian) consists of shallow water beach clastics, the reef carbonates, the deep marine and turbiditic formations. the uppermost of the tertiary unit comprises the handere formation, which is consist of clay stone, sand stone and very rarely gravel stone. it was covered by pedostratigraphic units of the quaternary, the villafrankian to late pleistocene high and low terraces, in the study area (ş enol et al, 1991) (fig 3). this model is supported by dinç et al ., (1991), for the 139relationship between micromorphological ... mediterranean coastal areas with pedogeomorphological criteria. it consists of young deposits of study area, which are calichified glacis and glacis or river type conglomerates. red mediterranean and reddish brown to brown soils and massive caliches (calcretes) occur with discordance in the pliocene and between the mid and late pleistocene periods (kapur et al., 1993). 3. methods 3.1 rock mechanics test blocks samples (fig 4 a and b) were taken from 13 different locations in the adana region. using a core-drilling machine at the laboratory, nx and bx size core samples were prepared from caliche blocks (fig 4 c and d). unit weight (uw), apparent porosity (n), schmidt rebound number (rn), shore hardness (sh), pwave velocity (vp), slake durability index (id2), point load index (is(50)), uniaxial compressive strength (ucs), average young’s modulus (eav) values of the samples were all measured according to international society for rock mechanics standards (isrm, 1981a). rock samples, having regular shapes, were used for unit weight and apparent porosity tests. samples were sunk into water for 48 hours. later, weight and dimensions of samples were measured with a scale having ±0.01 accuracy. after that, caliche samples were figure 2 generalised lithostratigraphic sections of the study area (yetiş, 1988). sezioni lito-stratigrafiche della zona studiata (yetis, 1988). 140 dried for 24 hours at 105 °c and weighted. determination of apparent porosity and unit weight was achieved using volume, dry weight and saturated weight of the samples. the schmidt hammer tests were carried out in the field on large caliche blocks samples. all tests were performed by n type schmidt hammer following isrm (1981b). the schmidt hammer tests were performed vertically on rock blocks with no discontinuity and cracks. each time, twenty readings were taken and the upper ten values were averaged. shore hardness values were determined using the c2 type shore schleroscope which was cleaned and calibrated using calibration block. test procedures included 2.44 gr diamond tipped hammer drop freely on the caliche sample and carefully measuring and longing the rebounding height on the scale which ranged 0 to 140. twenty readings were taken from each sample; and readings with the highest five and lowest five values were cancelled, and the remaining 10 readings were averaged according to isrm (1978a). the pundit and two transducers (a transmitter and a receiver) were used in all tests. three core samples were prepared (height/diameter 2-2.5) for each caliche samples. both faces of drill cores were trimmed and smoothed so that the receiver and the transmitter could cover the faces tightly. the test was carried out according to isrm (1978b). in the slake durability test, the apparatus combines the effects of both soaking and abrasion in order to evaluate the rate of weathering caused by water immersion. the test procedure was performed according to isrm (1979) standards with ele rm-310-2 test machine. ten rock slumps with equal dimensions were prepared for the slake durability test. rock slumps rotated in the steel mesh drum were partially immersed in water for ten minutes. samples were subjected to three cycles and durability index (id2) in which each cycle was calculated as a percentage ratio of final to initial dry weight of rocks in the drum after drying and wetting figure 3 pedostratigraphic sections of the study area (şenol et al., 1991). sezioni pedo-stratigrafiche (şenol et al., 1991). i̇. dinçer, a. acar & d. magaldi 141 cycles. in this study, the second cycle index (id2) was used for evaluation of slake durability index of caliches. the point load test is an index test to determine the strength of intact rocks. the system of this test consists of a hydraulic pump, a hydraulic jack, a pressure gauge and two steel points with standard dimensions. in the test, the rock sample is slowly loaded by activating the hand pump until failure of sample. the failure load is read from gauge. the test can be applied to irregular and regular rock samples in field or laboratory. there are three test methods, which are diametrical test, axial test and block test (isrm, 1985). in this study diametrical and axial tests were used in laboratory. caliche core samples were prepared with length/diameter ratio for 1/1. failure of rock samples was achieved within 10-60 seconds. the point load strength index is(50) was calculated using the correction factor. the uniaxial compressive strength tests were performed according to the isrm (1981c) standards. the test apparatus for the unconfined compressive tests consisted of a triaxial test machine (ele adr 2000) and a data acquisition system. nx and bx (length/diameter 2-2.5) size core samples were prepared for ucs. the loading rate was selected as 0.1 kn/s and failure of caliche samples was achieved within 5 – 10 minutes. at least five specimens were tested for each block samples. at the same time, isrm (1981c) standard test procedure was used to determine the average young’s modulus (eav). 3.2 micromorphological analyses thin sections (25 x 40 mm) of the samples were prepared for the microscopic observation. some common micro morphological features (microstructure, voids, coarse materials and matrix) were selected to evaluate micromorphological characteristics of caliche according the results and assumptions after several papers (magaldi, 1983; bullock et al., 1985; stoops 1988; magaldi and tallini, 2000). 3.2.1 microstructures same microstructures classification was used after magaldi, 1983 (fig 5): undifferentiated; size, shape and arrangement of matrix have a homogeneous crust. it contains few if any voids, rock fragments and organic materials; banded; laminated crust with different crystal size in individual laminae. matrix and aggregates generally horizontally elongated and separated by planar voids. nodular; groundmass consisting of many nodules. brecciated; crust formed by irregular network of fractures and clasts. 3.2.2 matrix the matrix of caliche consists mainly of calcite which is the cementing medium. the calcite material is composed of more or less similar crystalline or cryptocrystalline particles. the calcite crystals are less than 2 µm to 15 µm in size. three types of calcite cement relationship between micromorphological ... figure 4 various views of the caliche outcrops and samples. (a) hardpan level of caliche, (b) morphological structures of caliches, (c) cored caliche blocks, (d) nx and bx size caliche core samples. immagini degli affioramenti e dei campioni di crosta calcarea: (a) livello di hardpan entro la crosta calcarea, (b) microstruttura della crosta calcarea, (c) microstruttura di crosta calcarea con il foro di carotaggio, (d) campioni di crosta calcarea con dimensioni nx e bx. 142 occur in the matrix micrite, microsparite and sparite. micrite (2 to 4 µm) occurs as cementing material between the skeletal grains and as a clear rim around the grains within the groundmass. microsparite (4 to 10 µm) is formed by subhedral crystals. microsparite occurs as drusy mosaic filling between the micritic rimmed grains and rock fragments. it is also observed in the following cases: a) hypo coatings around the voids and cavities; b) calcite crystals increasing away from the walls of the grain / channels or cavities; c) elongated crystals perpendicular to the wall of the cavity/ channel or grain boundary. sparite (10 µm and above) generally occurs as infilling crystals within channels and voids. in some caliche samples, two or more different matrix types were observed at the same time. this matrix type was identified as mixed type. 3.2.3 voids stoop’s classification (1988) is used for classification of voids and spaces not occupied by solid material. brewer (1964) classified voids according to their morphology, considering them as individuals. his classification was used by bullock et al. (1985) with some small modifications. 3.2.4 coarse materials size, shape, frequency and internal characteristics are used as main criteria for description of the coarse materials. three main groups of coarse particles can be determined according to their composition and origin; (1) mineral grains, (2) rock fragments, (3) some coarse pedo features and components (nodule, organic matter, etc). 4. micromorphological index and correlation with rockindex properties rock-index properties of each sample were correlated with their selected micromorphological features. microstructure, voids, coarse materials and matrix were considered and each feature was quantified by a simple rating qualitatively related to degree of presumable strength of the sample. voids and coarse materials are rated according to both modal size and frequency. we used a rating 2 to 6 for one feature; 1 to 5 for four features; 1 to 3 for one feature (table 1). overall rating ranges from 7 to 29 increasing with the strength of material. this rating (mi) was obtained for each caliche sample. table 2 shows the micromorphological (semi-quantitative data) and engineering properties of caliche samples. koncagül and santi (1999) concluded that index properties of rocks are controlled by mineralogical composition, degree of cementation and re-crystallization. well cemented and completely recrystallizated samples have higher strength and durability than other samples. in order to investigate the influence of micromorphological characteristics on mechanical and physical-index properties of caliche samples, a number of correlations based on simple regression and some graphs were made. at the same time multiple linear regression variable selection analysis can be performed with a forward selection process, a backward elimination process, or a stepwise selection process that is a combination of the forward and the backward methods. the stepwise selection method selects or eliminates the i̇. dinçer, a. acar & d. magaldi figure 5 microstructure types of caliche samples. (a: undifferentiated b: laminated c: nodular d: brecciated) tipo di microstruttura dei campioni di crosta calcarea. (a:indifferenziata, b:laminata, c: nodulare, d: brecciata). 143relationship between micromorphological ... variables as per given user probability criteria. a dependent variable or response variable is related to predictor or independent variable(s). the objective was to construct a regression model relating the dependent variable, y, to independent variable(s). stepwise forward selection procedure was used to select the best suitable regression model of the form to predict the uniaxial compressive strength (ucs) of caliches. y = βo + β1x1 + β2x2, + .... + βk xk+ en, , (1) βo, β1 .... βk are the regression coefficients, and x1, x2 , xk, are the selected independent variables. en is an error term representing the magnitude of y not accounted for by other terms in the equation. 5. results 5.1 geomechanical properties geomechanical properties of caliches are assumed to be controlled by mineralogical composition, degree of cementation and recrystallization. well cemented and completely recrystallizated samples have higher strength and durability than other samples. table 2 shows the laboratory test results of caliche samples. obtained values of unit weight of the studied caliche blocks vary from 14.96 kn/m3 to 22.00 kn/m3. apparent porosity (n) is fluctuated between %16 and %35. schmidt rebound values (rn) of caliches range between 14.50 and 39.80. shore hardness (sh) of caliches varies from 4.20 to 22.50. highest pwave velocity (vp) was 1444 m/s, while the lowest was calculated as 375 m/s. the slake durability test results (id2) of caliche blocks ranged from 65.36 to 97.53%. point load index (is(50)) varies from 0.53 to 1.91 mpa. the unconfined compressive strength (ucs) of the samples ranges between 2.03 and 9.54 mpa. the value of average young’s modulus (eav) varies from 0.16 to 1.29 gpa. 5.2 micromorphology caliche has the following micromorphological features: undifferentiated, nodular and brecciated microstructures with 10yr 8/2, 5yr 5/6, 5yr 8/6, 10yr 7/4, 10 yr 8/6 and 10yr 5/4 colours; dark calcite matrix with micrite and rarely microsparite groundmass occurring in the voids and nodules; microsparite and sparite rarely occurring as drusy mosaic filling in the voids, serrate boundary between micrite and microsparite; very dense and irregularly shaped nodules, dark greyish and white in colour with microcrystalline ground mass. edges of chambers, simple packing voids, vughs, channels and vesicles type voids are rough-undulating, completely unaccommodated. voids frequency increases up to % 50 in some samples; c/f-related distribution pattern is close-single-open spaced porphyric; coarse materials consist of scattered angular grains of quartz, silica, tephra and limestone their sizes range 5 µm to 1000 µm; large grains (>1000 µm) are rarely observed. few orthic nodules and trace of plant root remains were observed. some microscopic pictures under polarised light are given in fig. 6. 5.3 correlation of micromorphological and engineering parameters of caliche mean values of index properties of microstructures types which are identified for caliche samples, are given in fig 7. according to results undifferentiated microstructure has higher mean values than other types. but this type has similar mean values with brecciated with grain to grain contacts only for slake durability test. microstructures types are probably the most important character controlling the mechanical behaviour of caliches. in a uniaxial compressive test stresses are likely to concentrate along the sample no : description : characteristic type rating sample microstructure undifferentiated 6 banded 4 nodular 2 brecciated 2 not: brecciated with grain to grain contacts 6 voids size(µm) <50 5 50-100 4 100-500 3 500-1000 2 >1000 1 frequency (%) <5 5 5-15 4 15-30 3 30-50 2 >50 1 coarse materials size(µm) <50 5 50-100 4 100-500 3 500-1000 2 >1000 1 frequency (%) <5 5 5-15 4 15-30 3 30-50 2 >50 1 matrix sparite 3 mixed type 3 microsparite 2 micrite 1 total rating table 1 micromorphological rating form. punteggio attribuito alle caratteristiche micromorfologiche. 144 i̇. dinçer, a. acar & d. magaldi e ng in ee ri ng p ar am et er s m ic ro m o rp ho lo g ic al p ar am et er s s am p le v o id s c o ar se m at er ia ls n o g (r n ) (s h ) v p n i d 2 is (5 0) u c s e av m ic ro st ru ct ur e m at ri x ( m i) (k n /m 3 ) (m /s n) (% ) (% ) (m p a) (m p a) (g p a) s iz e fr eq ue nc y s iz e fr eq ue nc y (µ m ) (% ) (µ m ) (% ) b l1 18 .5 1 28 .0 0 13 .5 4 68 1 28 .1 2 90 .0 8 1. 13 5. 63 0. 55 u nd iff er en tia te d 10 050 0 < 5 50 -1 00 515 m ix ed 25 ty p e b l2 17 .9 3 24 .6 0 8. 58 49 1 28 .4 4 94 .2 9 0. 97 3. 37 0. 19 n od ul ar 50 010 00 15 -3 0 < 50 < 5 m .s p ar ite 19 b l3 21 .5 5 27 .8 0 12 .1 3 11 46 21 .0 0 97 .5 3 1. 25 7. 85 0. 88 u nd iff er en tia te d < 50 15 -3 0 < 50 < 5 s p ar ite 27 b l4 14 .9 6 14 .5 0 4. 20 37 5 34 .7 9 65 .3 6 0. 53 2. 03 0. 16 n od ul ar 10 050 0 30 -5 0 10 050 0 < 5 m ic rit e 16 b l5 19 .1 7 31 .4 0 12 .0 4 50 9 23 .9 8 92 .7 6 0. 96 4. 52 0. 52 b re cc ia te d 50 010 00 15 -3 0 50 -1 00 515 m ic rit e 16 b l6 18 .7 0 35 .4 0 18 .0 8 10 85 26 .3 6 96 .9 2 1. 69 6. 28 0. 68 b re cc ia te d 50 -1 00 < 5 50 -1 00 15 -3 0 m .s p ar ite 24 (g ra in t o gr ai n co nt ac ts ) b l7 17 .3 2 19 .9 0 8. 40 43 6 31 .7 0 84 .8 2 0. 78 2. 99 0. 19 b re cc ia te d 10 050 0 515 50 010 00 30 -5 0 m ic rit e 14 b l9 20 .3 3 26 .9 0 11 .0 0 75 8 24 .1 5 90 .5 2 1. 03 6. 50 0. 82 u nd iff er en tia te d 50 010 00 < 5 < 50 < 5 m ix ed 26 ty p e b l11 19 .8 4 26 .0 0 11 .8 0 72 7 23 .7 5 93 .5 2 0. 97 4. 90 0. 63 b re cc ia te d 10 050 0 515 50 010 00 15 -3 0 m ic rit e 19 (g ra in t o gr ai n co nt ac ts ) b l12 15 .3 7 22 .6 0 10 .5 2 43 1 35 .4 9 92 .3 6 0. 95 2. 45 0. 19 n od ul ar 50 -1 00 30 -5 0 < 50 < 5 m ic rit e 18 b l14 22 .0 0 39 .8 0 22 .5 0 14 44 16 .2 3 96 .8 1 1. 91 9. 54 1. 29 u nd iff er en tia te d 10 050 0 515 < 50 < 5 m ix ed 26 ty p e b l14 a 18 .8 7 22 .0 0 9. 60 71 3 26 .7 3 90 .1 5 0. 79 4. 32 0. 59 b re cc ia te d 10 050 0 15 -3 0 > 10 00 30 -5 0 m ic rit e 16 (g ra in t o gr ai n co nt ac ts ) b l15 18 .2 6 27 .5 0 11 .4 6 47 7 26 .2 3 91 .9 0 0. 86 2. 65 0. 18 n od ul ar 10 050 0 15 -3 0 10 050 0 15 -3 0 m ic rit e 15 γ: u ni t w ei gh t, v p : p -w av e v el oc ity , r n : s ch m id t r eb ou nd n um b er , s h : s ho re h ar d ne ss , n: a p p ar en t p or os ity , i d 2 : s la ke d ur ab ili ty in d ex ( tw o cy cl e) , is (5 0) : p oi nt l oa d i nd ex ( m p a) , u c s : u ni ax ia l c om p re ss iv e s tr en gt h, e a v : a ve ra ge y ou ng 's m od ul us , m i: m ic ro m or p ho lo gi ca l i nd ex . ta b le 2 e ng in ee rin g an d m ic ro m or p ho lo gi ca l p ro p er tie s of s am p le s. p ro p rie tà t ec ni ch e e ca ra tt er is tic he m ic ro m or fo lo gi ch e d ei c am p io ni . edges of cracks, voids and coarse materials. a rock with these features easily fails at low stress rate. therefore, while undifferentiated microstructures can withstand higher uniaxial compressive loads, brecciated type is weaker than other types. nevertheless some brecciated samples showed high strength because the number of grain to grain contacts is probably higher, so the applied external force is distributed over larger contact surface. mineralogy of bonding or cementing material is an important property that controls strength, hardness and durability (koncagül and santi, 1999). quartz provides the strongest binding followed by calcite and iron minerals. clay binding material is the weakest. caliche consists of micrite, microsparite and sparite calcite matrix. mean values of index properties are 145relationship between micromorphological ... figure 6 thin section views of samples. sezioni sottili dei campioni. 146 given for matrix type of caliches in fig 5. micrite values are normally lower than values of other types. sparite matrix can withstand higher uniaxial compressive loads than micrite. probably because micrite matrix occurs faster than sparite and micrite couldn’t be cemented sufficiently. porosity has a significant effect on mechanical performance. price (1960) and dube and singh (1972) reported that in sedimentary rocks all strength properties decrease with increasing porosity. this happens because high porosity allows the stress-induced microfractures to propagate (howarth and rowlands, 1986). the low uniaxial compressive strength in caliche samples is related to high frequency of voids. correlation matrices summarizing the determination coefficients of the index properties with significance levels are given in table 3. the relationships between ucs vs uw, ucs vs vp, and ucs vs mi yielded statistically significant correlations. based on statistical analyses, linear relationships were fitted between the mi and some index property. uniaxial compressive strength, p-wave velocity, average young’s modulus and point load index have significant correlations with micromorphological index (mi). instead slake durability index, schmidt hardness, shore hardness and unit weight have very weak correlation with mi. these findings suggested that micromorphological characteristics are controlling mechanical properties (as ucs) more than unit weight (uw) and durability (id2). in order to determine how much the caliche strength is controlled by micromorphological properties mi was compared to uniaxial compressive strength (ucs) which is the most widely used design parameter in rock engineering the correlations of thirteen samples is statistically significant with r2 = 0.73 (fig 8). according to fig 8, ucs increases with the increasing of mi. 5.4 prediction of the uniaxial compressive strengt h of caliche ucs is the most important index property in rock mechanics. testing procedure has been standardized by both the american society for testing and materials figure 7 mean values of rock-index properties of microstructure and matrix types (ud: undifferentiated, n: nodular, b: brecciated, bg: brecciated with grain to grain contacts, mc: microsparite, sp: sparite and mt: mixed type). valori medi delle proprietà indici delle varie tipologie di microstruttura e matrice (ud: indifferenziate, n: nodulari, b: brecciate, bg: brecciate con contatti granulo-granulo, mc: microsparite, sp: sparite e mt: tipo misto). i̇. dinçer, a. acar & d. magaldi 147 un-standardised coefficients independent variables β std. error t sig. constant -5.742 2.131 -2.694 0.023 vp 0.0045 0.001 5.171 0.000 uw 0.394 0.139 2.834 0.018 constant -7.137 1.559 -4.578 0.001 vp 0.003 0.001 4.025 0.003 uw 0.383 0.098 3.906 0.004 mi 0.133 0.040 3.336 0.009 table 4 statistics of some parameters used to estimate ucs. valori statistici di alcuni parametri usati per valutare la resistenza a compressione uniassiale(ucs). table 5 correlation and determination coefficients of the equations used to estimate ucs. coefficienti di correlazione e di determinazione delle equazioni usate per valutare l’ucs. r r2 adjusted r2 standard error of the estimate 0.971a 0.943 0.932 0.589 0.987b 0.975 0.966 0.415 a. predictors: (constant), vp, uw b. predictors: (constant), vp, uw, mi relationship between micromorphological ... table 3 correlation matrix of engineering and micromorphological index with significance level. correlazione di matrice dell’indice tecnico e micromorfologico con livello di significatività. uw rn sh vp n id2 is(50) ucs eav uw rn ,724(**) sh ,667(*) ,952(**) vp ,805(**) ,771(**) ,839(**) n -,971(**) -,790(**) -,722(**) -,806(**) id2 ,669(*) ,747(**) ,680(*) ,553(*) -,630(*) is(50) ,648(*) ,910(**) ,956(**) ,894(**) -,682(*) ,655(*) ucs ,889(**) ,779(**) ,800(**) ,947(**) -,863(**) ,567(*) ,841(**) eav ,882(**) ,742(**) ,777(**) ,927(**) -,873(**) ,506 ,782(**) 0.97(**) mi ,641(*) ,597(*) ,618(*) ,781(**) -,569(*) ,451 ,734(**) ,855(**) ,767(**) ** correlation is significant at the 0.01 level (2-tailed). * correlation is significant at the 0.05 level (2-tailed). (astm) and the international society for rock mechanics (isrm). the tests are performed on well prepared core samples with a time consuming and expensive procedure. preparing well core samples is rather difficult in soft rock like marl, caliches and others so many researchers employed simple models to estimate ucs by the rock index tests. then a multiple linear regression analyses were considered to obtain equations for estimating ucs from several index properties and mi. the data set is given in table 2. regression analyses were performed in two stage using spss for windows statistical software. in the fist stage, only the quoted index properties (table 4 and table 5) were used as an independent variable to predict ucs: ucs = 5,742 + 4.5x10-3 vp + 0.39uw (2) in the second stage, all index properties and micromorphological index (mi) were used as independent variables and the stepwise forward technique for regression analyses are carried out to predict ucs. the best model for ucs was: ucs = 7.137+3.06x10-3 vp+ 0.38uw+0.13mi (3) the adjusted r2 values indicate that the above multiple regression models explain 93.2% in equation (2) and 96.6 % in equation (3) of the total variation, respectively (table 5). fig. 9 and fig. 10 support the assumption of a linear relationship between the dependent variable ucs and the independent variables pwave velocity (vp), unit weight (uw) and micromorphological index (mi). regression equations have slopes equal to 1.0, high correlation coefficient and very low intercept values. the residual analyses confirmed that the assumption of a linear relationship is valid. 6. conclusions the caliche occurs from east to west in the southern part of turkey. caliche adversely affects cut slope stability, earth fill material sensitivity and ground stability at structure sites along the motorway which is being constructed in the southern turkey. caliches are very problematic materials for study. four micromorphological parameters which are significant on engineering behaviour of caliche were identified as follows: microstructure, voids, coarse 148 figure 9 comparison of measured and the estimated ucs values for the model excluded mi. confronto tra i valori ucs misurati e quelli stimati con la relazione empirica, escludendo il parametro mi. figure 10 comparison of measured and the estimated ucs values for the model with mi. confronto tra i valori ucs misurati e quelli stimati con la relazione empirica, tenendo conto del parametro mi. i̇. dinçer, a. acar & d. magaldi figure 8 micromorphological index (mi) versus uniaxial compressive strength (ucs) for thirteen samples. indice micromorfologico vs. resistenza alla compressione uniassiale (ucs) per i tredici campioni di crosta calcarea. 149 material and matrix. microstructure is the most important parameter on engineering behaviour of caliche followed by voids, coarse materials and matrix. micromorphological characteristics are more effective on mechanical properties than index properties and durability. results were obtained from a limited number of samples but the employed methodology seems to be promising for reaching indicative values of some rock index properties. based on these linear relationships among the engineering properties, uniaxial compressive strength, p-wave velocity, average young’s modulus and point load index have significant correlations with a proposed micromorphological index (mi). the results suggested that strength of caliche is also controlled by micromorphological properties. then the statistically most reliable model as ucs = 7.137 + 3.06x10-3 vp + 0.38uw + 0.13mi could be an accurate and less expensive estimation of ucs for engineering purposes based on micromorphogical as well geomechanic properties of the material. lacking geomechanical properties ucs can be assessed with lesser precision by their simple relationship with mi. references atabey e., atabey n. and kara h. (1998) sedimentology of caliche (calcrete) occurrences of the kırsehir region. mineral res. expl. bull., 120, 6980. bell f.g., (1978) the physical and mechanical properties of the fell sandstone, northumberland, england. engineering geology 12: pp. 1–29. brewer r. (1964) fabric and mineral analysis of soils. j.wiley inc., new york. 470 pp. bullock p., fedoroff n., jongerius a., stoops g., tursina t. (1985) handbook for soil thin section descriptions. waine research publications, wolverhampton, england. di̇nçer u., senol m., kapur s., sarı m. (1991) catenary soil relationships in the çukurova region, southern turkey. catena 18, 185-196. dube ak, singh b. e. (1972) effect of humidity on tensile strength of sandstone. journal of mines metals and fuel; 20 (1):8-10. engin c. koncagül, paul m. santi (1999) predicting the unconfined compressive strength of the breathitt shale using slake durability, shore hardnesss and rock structural properties. international journal of rock mechanics and mining sciences 36:139-153. fahy mp, guccione mj (1979) estimating strength of sandstone using petrographic thinsection data. bull. assoc. eng. geol.16:467-485. howarth d.f., rowlands j.c. (1986) development of an index to quantify rock texture for qualitative assessment of intact rock properties. geotechnical testing j. 9 (4), 169–179. international society for rock mechanics (1978a) commission on standardization laboratory and field results. suggested methods for determining hardness and abrasiveness of rocks. int j rock mech min sci geomech abstr;15: 89–97. international society for rock mechanics (1978b) suggested methods for determining sound velocity. int j rock mech min sci geomech abstr;15:53–8. international society for rock mechanics (1979) commission on standardization of laboratory and field tests, suggested methods for determining water content, porosity, density, absorption and related properties and swelling and slake durability index properties. int. j. rock mech. min.sci. 16, 148–156. international society for rock mechanics (1981a) rock characterization testing and monitoring, isrm suggested methods. international society for rock mechanics. 211 pp. international society for rock mechanics (1981b) suggested methods for determining hardnesss and abrasiveness of rocks, part 3. commission on standardization of laboratory and field tests, pp 101–102. international society for rock mechanics (1981c) suggested methods for determining the uniaxial compressive strength and deformability of rock materials. international society for rock mech. commission on standardization of laboratory and field tests, pp 111–116 international society for rock mechanics (1985) suggested methods for determining point-load strength.int j rock mech min sci; 22:53–60. kapur s., yaman s., gökçen s.l., yetiş c. (1993) soil stratigraphy and quaternary caliche in the misis area of the adana basin, southern turkey, catena, 20, 431-445. jeng f.s., weng m.c., lin m.l., and huang t.h. (2004) influence of petrographic parameters on geotechnical properties of tertiary sandstones from taiwan. engineering geology 73, 71–91. magaldi d. (1983) calcareous crust (caliche) genesis in some mollisols and alfisols from southern italy: a micromorphological approach. soil micromorphology. v: 2 pp: 623-635. a.b academic publishers. magaldi d, tallini m (2000) a micromorphological index of soil development for the quaternary geology research. catena. v: 41, pp: 261-276. price nj. (1960) the compressive strength of coal measure rocks. colliery engineering; 37(437): 28392. shakoor a, bonelli re (1991) relationship between petrographic characteristics, engineering index properties and mechanical properties of selected sandstones. bull. assoc. eng. geol. 28:55-71. stoops g., (1998) key to the isss “handbook for soil thin section description”. natuurwet. tijdschr. 78: 193-203. şenol m., kapur s., gökçen s.l. (1991) litho-pedological and sedimentological study of the late tertiary-quaternary of the adana-balcalı area. geosound, adana 18, 79-91. tugrul a., and zarif i.h. (1999) correlation of mineralogical and textural characteristics with engineering properties of selected granitic rocks from turkey. engineering geology 51, 303–317. ulusay r., tureli k., and ider m.h., (1994) prediction of engineering properties of a selected litharenite sandstone from its petrographic characteristics relationship between micromorphological ... using correlation and multi-variate statistical techniques. engineering geology, 37, 135-157 yetiş c. (1988) reorganisation of the tertiary stratigraphyin the adana basin, southern turkey. newsletter, stratigraphie. 20 (1), 43-58. yılmazer i, smith i (1992) yumusakken ve sertken seviyelerinden olusan kalisin jeolojik ve jeoteknik özellikleri. türkiye jeoloji kurultayı bülteni s7, 145152. zorlu k, ulusay r, ocakoglu f, gokceoglu c, sonmez h. (2004) predicting intact rock properties of selected sandstones using petrographic thin-section data. int. j. rock mech. acknowledgements this study was supported by tübïtak (project no: 104y189). the authors would l ike to thank the çukurova university scientific research project unit for providing the financial support needed for this project (project no: mmf-2004bap-11 and mmf-2004d-19). 150 ms. ricevuto il 5 luglio 2006 testo definitivo ricevuto il 26 giugno 2007 ms. received: july 5, 2006 final text received: june 26, 2007 i̇. dinçer, a. acar & d. magaldi imp.laposta& le unità stratigrafiche di riferimento nella rappresentazione cartografica dei depositi plio-quaternari continentali nel progetto carg esempi relativi all'italia centro-meridionale elena la posta*, stefania nisio & felicia papasodaro apat servizio geologico d'italia/dipartimento difesa del suolo, roma, italy *corresponding author: e. la posta, apat servizio geologico d'italia/dipartimento difesa del suolo via curtatone, 3 -00185 roma, italy. e-mail: <elena.laposta@apat.it> abstract: e. la posta, s. nisio & f. papasodaro, reference stratigraphic units for plio-quaternary deposits mapping in carg. within the new geological map of italy at the 1:50.000 scale, unconformity bounded stratigraphic units have mostly been adopted, in the central-southern part of the country, to represent quaternary continental deposits. however, field geologists applied different criteria for their classification because of both the lack of prescriptions by stratigraphic codes and the absence of previous experience with such units in the italian setting. in some areas ubsu have been used as tools that allow us to synthesize: in a regional framework only a few units, bounded by disconformity related to important climatic events, have been identified. in other areas, due to the complex recent geological evolution and to poor correlation elements, ubsu have allowed only for local synthesis. parole chiave: unità stratigrafiche, ubsu, depositi del quaternario, carta geologica d'italia. keywords: stratigraphic units, ubsu (unconformity bounded stratigraphic units), quaternary deposits, geological map of italy. il quaternario italian journal of quaternary sciences 21(1a), 2008 57-60 premessa uno degli elementi innovativi nella nuova carta geologica d'italia, in corso di realizzazione attraverso il progetto carg, è l'interesse per lo studio e la rappresentazione dei depositi del quaternario. in assenza di unità formalizzate e di regole consolidate, il servizio geologico d'italia ha ritenuto, in seguito ad un lungo dibattito, che le unità stratigrafiche più adatte alla rappresentazione di questi depositi, oltre che riconosciute dai codici internazionali (issc, 1994), fossero le unità a limiti inconformi (cnr, 1992; cis, 2003). nell'individuazione di queste unità vengono presi in considerazione i cicli deposizionali, definiti attraverso l'identificazione di superfici di discontinuità che limitano depositi riferibili ad una stessa fase sedimentaria. queste superfici limite possono essere il prodotto sia di fasi erosive sia di lacune di sedimentazione, marcate spesso da paleosuoli, sia del concorso di entrambi i fenomeni. l'unità di base delle ubsu è il sintema, compreso gerarchicamente tra il supersintema, l'unità a rango più elevato limitata da una superficie di discontinuità di importanza ed estensione regionale, ed il subsintema, l'unità a rango meno elevato limitata da una superficie di discontinuità di carattere locale. la mancanza di una sperimentazione precedente di tali unità in ambito nazionale ha portato tuttavia ad un uso estremamente eterogeneo da parte dei gruppi di lavoro che stanno realizzando i fogli al 50.000, sia per quanto riguarda il numero di superfici di discontinuità prese in considerazione e la valenza ad esse attribuita, sia per quanto riguarda conseguentemente il numero di unità individuate ed il rango ad esse assegnato. a quasi vent'anni dall'inizio del progetto carg, nell'ambito dell'italia centro-meridionale sono in corso di realizzazione circa 150 fogli. partendo dall'analisi di quanto realizzato si possono trarre una serie di considerazioni sui differenti approcci seguiti e sulle problematiche più ricorrenti nella classificazione e rappresentazione dei depositi plio-quaternari. criteri ed esempi nell'italia centro-meridionale nonostante l'adozione delle ubsu sia ormai prevalente, in alcune regioni la rappresentazione del quaternario viene ancora portata avanti con un approccio tradizionale, ricorrendo sia alle unità litostratigrafiche, sia alle categorie senza formali connotazioni stratigrafiche previste dal dizionario delle unità quaternarie del servizio geologico d'italia (sgn, 1997; 2003), che fanno essenzialmente riferimento alla genesi dei depositi. questa impostazione caratterizza in particolare i progetti cartografici della regione toscana, della sicilia orientale, della calabria ed alcuni fogli della regione basilicata. a grandi linee nell'impostazione delle legende basate su unità a limiti inconformi si riconoscono due differenti approcci, l'uno con finalità di sintesi, l'altro con finalità più analitiche. nei progetti cartografici delle marche, dell'abruzzo ed in parte della sicilia occidentale le ubsu sono impiegate come strumento di sintesi. vengono 58 e. la posta et al. infatti individuate poche unità, valide per tutto il territorio regionale, delimitate da discontinuità legate ad importanti eventi climatici, per loro natura ubiquitari e quindi rintracciabili su aree estese. la correlazione di depositi e di superfici anche molto distanti fisicamente è comunque supportata da dati cronologici e talora favorita dalla presenza di l ivell i vulcanoclastici. nell'ambito dei diversi fogli può variare il grado di gerarchizzazione delle unità, come nel caso del supersintema di colle ulivo-colonia montani dei fogli delle marche, indifferenziato nel foglio urbino e suddiviso in sintemi ad esempio nel foglio jesi, e del supersintema aielli-pescina dei fogli dell'abruzzo, che raggruppa i depositi più antichi (pliocene?-pleistocene inferiore), indifferenziato nei fogli già stampati(1)* per la difficoltà di correlare a distanza affioramenti resi frammentari dalle dislocazioni tettoniche e dall'erosione fluviale e suddiviso in più sintemi in altri(2). tuttavia, nell'attuazione dei vari progetti cartografici, queste unità, seppur valide per ampie aree, spesso non superano i limiti regionali, come nel caso dei sopra citati fogli delle marche e dell'abruzzo nei quali unità assimilabili hanno diversa denominazione e talora diverso rango. il sintema di matelica dei fogli delle marche, ad esempio, sembra corrispondere al sintema di valle majelama dei fogli della regione abruzzo: entrambi racchiudono i depositi del pleistocene superiore e sono delimitati da superfici di erosione e paleosuoli correlati agli stessi eventi climatici. le conseguenze di tali scelte si manifestano con particolare evidenza nei fogli ubicati al confine tra regioni, dove l'adozione di più successioni di unità nell'ambito dello stesso foglio è talvolta giustificata da esigenze di coordinamento piuttosto che da motivazioni scientifiche(3). nella rappresentazione dei depositi più recenti, compresi tra il pleistocene superiore e l'olocene, in sicilia occidentale sono state considerate discontinuità riferibili ad importanti eventi climatici che hanno portato ad oscillazioni del livello del mare riconoscibili a scala regionale. sono state in tal modo definite tre unità sintemiche, comuni agli undici fogli del progetto(4). l'adozione di un approccio cartografico omogeneo, che utilizza le ubsu come strumento di sintesi regionale, si riscontra anche nei fogli che ricadono su estesi bacini di sedimentazione che hanno favorito la continuità dei corpi sedimentari. e' il caso del settore settentrionale del tavoliere delle puglie(5) dove è stata individuata una discontinuità di carattere regionale connessa all'importante fase erosiva verificatasi nel pleistocene inferiore, successivamente all'emersione della fossa bradanica. i successivi depositi marini ed alluvionali, che testimoniano il progressivo instaurarsi nell'area del dominio continentale, sono stati riuniti all'interno di un unico supersintema. al suo interno sono state individuate numerose unità di rango inferiore, soprattutto sintemi, separate da discontinuità di importanza minore. una situazione analoga è rappresentata dai fogli del litorale laziale(6) nei quali la discontinuità regionale del pleistocene inferiore, connessa con un periodo di stazionamento basso del livello del mare, è stata individuata come limite inferiore del supersintema aureliopontino. all'interno di questo vasto contenitore, comune ai diversi fogli, la complessa successione di depositi sedimentari e vulcanici, interessata da superfici di discontinuità di estensione minore, è stata riferita a più sintemi che differiscono nel settore settentrionale e nel settore meridionale. nel foglio ugento, ubicato al limite meridionale della regione puglia, attraverso una lettura dettagliata delle superfici di erosione che interessano una successione monotona di calcareniti, riferibili all'intervallo compreso tra il pleistocene medio ed il pleistocene superiore, sono stati distinti sei sintemi corrispondenti ad altrettanti cicli deposizionali. il legame tra le discontinuità e le variazioni eustatiche del livello del mare fa sì che, anche in questo caso, le unità siano caratterizzate da un'ampia estensione. * i numeri ad apice permettono di identificare i fogli presi in considerazione, citati in bibliografia. tab. 1 tipi di unità adottate e cartografate in aree caratterizzate dalla coesistenza di prodotti vulcanici e di depositi sedimentari. units defined and mapped where both volcanic products and sedimentary deposits crop out. unità adottate unità cartografate apparati unità unità prodotti depositi vulcanici sintemiche litostratigr. vulcanici sedimentari supersintemi sintemi subsintemi unita' unita' unita' unita' sintemiche litostratigr. sintemiche litostratigr. area laziale(6) x x x x x piana campana(8) x x x x x x vulture(9) x x x x x etna(10) x x x x in alcune regioni la presenza di contesti geologici a diversa evoluzione, la frammentarietà degli affioramenti dei depositi continentali quaternari e la carenza o mancanza di elementi di correlazione ha indotto all'adozione di una metodologia di tipo analitico che tiene conto della specificità di ciascun bacino o settore individuato nei fogli. ad esempio, nella regione campania sono state definite specifiche successioni di unità nei diversi settori individuati, corrispondenti a conche intermontane, bacini idrografici, piane costiere, ecc. nella legenda del foglio salerno, particolarmente complessa, sono state distinte 26 unità quaternarie formali, di tipo sintemico e litostratigrafico; queste ultime sono utilizzate ad integrazione delle unità a limiti inconformi per definire corpi geologici a litologia peculiare, come ad esempio i travertini. dalla correlazione delle unità individuate nei diversi contesti si desume che talvolta nello stesso intervallo cronologico è stato riconosciuto un diverso numero di cicli deposizionali ai quali è stato attribuito un differente rango gerarchico. la difficoltà di operare correlazioni tra bacini idrografici caratterizzati da un diverso numero di unità o tra settori litoranei a diversa evoluzione, porta talora ad individuare specifiche successioni corrispondenti ai diversi ordini di depositi alluvionali e marini terrazzati. ad esempio, in alcuni fogli della regione basilicata(7) sono stati definiti specifici supersintemi per ciascun bacino idrografico, anche di basso ordine gerarchico; i vari ordini sono stati rappresentati come sintemi. analogamente in sicilia occidentale(4) i depositi alluvionali e marini del pleistocene medio sono stati divisi in sintemi, riferibili ai diversi bacini e settori costieri; ai vari cicli deposizionali è stato attribuito il rango di subsintema. l'italia centro-meridionale è caratterizzata dalla presenza di importanti centri vulcanici attivi nel quaternario. in tali ambiti si osserva spesso l'integrazione di unità a limiti inconformi e di unità litostratigrafiche. nei fogli sono state per lo più definite unità sintemiche di vario rango, che raggruppano al loro interno sia i prodotti vulcanici sia i depositi sedimentari; in tal modo viene realizzata la correlazione tra ambienti sedimentari diversi. nella maggior parte dei casi, soprattutto per quel che riguarda i prodotti vulcanici, le unità sintemiche costituiscono dei contenitori di unità litostratigrafiche e non sono utilizzate nella rappresentazione cartografica (tab.1). conclusioni come si evince dalla sintetica rassegna presentata, nell'italia centro-meridionale per la cartografia dei depositi continentali quaternari vengono adottate prevalentemente le unità a limiti inconformi. tuttavia esse non sempre sono state utilizzate come strumento di sintesi; la complessa evoluzione geologica recente dell'italia centro-meridionale e la carenza di elementi utili di correlazione ha talvolta favorito la sintesi a scala locale. l'applicazione di questa metodologia, indubbiamente rigorosa, ha prodotto la redazione di legende molto articolate, caratterizzate da un gran numero di unità, e di carte di difficile lettura. tra i problemi più ricorrenti si può senz'altro citare l'applicazione di un criterio non omogeneo nella carat59le unità stratigrafiche di riferimento ... terizzazione delle superfici di discontinuità e nell'attribuzione del rango alle unità. bibliografia apat servizio geologico d'italia (2006) carta geologica d'italia alla scala 1:50.000 e relative note illustrative. fogli 359 l'aquila(1), 360 torre de' passeri( 1), 368 avezzano(1), 369 sulmona(1). apat servizio geologico d'italia (in allestimento per la stampa) carta geologica d'italia alla scala 1:50.000 e relative note illustrative. fogli 279 urbino, 292 jesi, 353 montalto di castro(6), 354 tarquinia(6), 407 s. bartolomeo in galdo(5), 448 ercolano(8), 451 melf i(9), 467 salerno(8), 607 corleone(4), 625 acireale(10). i fogli sono consultabili sul sito www.apat.it. apat servizio geologico d'italia (in corso di realizzazione) carta geologica d'ital ia al la scala 1:50.000 e relative note illustrative. fogli 344 tuscania(6), 355 ronciglione(6), 358 pescorocchiano(3), 374 roma(6), 378 scanno(2), 387 albano laziale(6), 396 san severo(5), 408 foggia(5), 421 ascoli satriano(5), 422 cerignola(5), 431 caserta est(8), 447 napoli(8), 452 rionero in vulture(9), 465 procida(8), 466 sorrento(8), 471 irsina(7), 536 ugento, 585 mondello(4), 593 castellammare del golfo(4), 594 partinico(4), 595 palermo(4), 596 capo plaja(4), 608 caccamo(4), 609 termini imerese(4). i fogli sono consultabili sul sito www.apat.it. ciscommissione italiana di stratigrafia (2003) guida italiana alla classificazione e alla terminologia stratigrafica. quaderni, serie iii, 9,155 pp. apat/dipartimento difesa del suolo. c.n.r.commissione per la cartografia geologica e geomorfologica (1992) carta geologica d'italia 1:50.000. guida al rilevamento. quaderni del servizio geologico nazionale, serie iii, 1, 203 pp. issc-international subcommission on stratigraphic classification (1994) international stratigraphic guide: a guide to stratigraphic classification, terminology and procedure. 2nd edition.gsa, boulder. 214 pp. servizio geologico d'italia (1997) carta geologica d'italia 1:50.000. banca dati geologici. quaderni del servizio geologico nazionale, serie iii, 6,142 pp. servizio geologico d'italia (2001) indicazioni per il r i levamento del quaternario continentale. circolare carg disponibile sul sito web www.apat.it. servizio geologico d'italia (2003) indicazioni per la rappresentazione cartografica del quaternario continentale. circolare carg disponibile sul sito web www.apat.it. ms. ricevuto il 2 aprile 2008 testo definitivo ricevuto il 17 aprile 2008 ms. received: april 2, 2008 final text received: april 17, 2008 ostermann et al 183-189.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 33 (2), 2020, 183-189 characteristics and dating of the rock avalanche at pragser wildsee/lago di braies (dolomites, italy). marc ostermann 1, susan ivy�ochs 2, frowin ruegenberg 3, christof vockenhuber 2 1 geological survey of austria, vienna, austria. 2 ion beam physics, eth, zurich, switzerland. 3 department of geology, university of innsbruck, innsbruck, austria. corresponding author: m. ostermann <marc.ostermann@geologie.ac.at> abstract: major gravitational slope deformations are widely disseminated in the dolomite mountains (ne italy), one of the world's most conspicuous landscapes and part of the unesco world heritage list. in the prags valley a rock avalanche still dams a backwater lake the pragser wildsee/lago di braies. the volume of rock debris accumulations comprise approximately 30-40 106 m³ of mainly dolomitic rock and the area covered by rock debris is about 3.5 km². the run-out distance of about 8.5 km and a maximum vertical drop of 1150 m (h/l-ratio: 0.13) yield a run-out travel angle (fahrböschungswinkel) of 8°. especially in the surrounding of schmieden/ferrara a hummocky landscape with numerous hills and ridges is developed. here some classical toma hills are encountered, i.e. isolated coneto pyramidalor roof-shaped hills composed of rock avalanche debris. mainly because assumptions about the origin of this hummocky landscape has been related to glacial processes, the formation of pragser wildsee was previously thought to be of lateglacial age. we applied cosmogenic 36cl surface exposure dating of four boulders within the debris accumulations and obtained an early holocene age of 8.3±0.7 ka for the event. our findings go along with the results of published radiocarbon dates from sediment-drillcores within the backwater lake, which indicate a recalibrated minimum age for the slope failure of 7410±100 cal years bp (irmler, 2003). the accumulations at pragser wildsee show strong similarities to the obernberg rock avalanche in geomorphology as well as in age, making them the first examples of early holocene rock avalanches forming toma hill landscapes. keywords: rock avalanche, early holocene, cosmogenic nuclide dating, toma hills, pragser wildsee/lago di braies, dolomites. � 1. introduction in the past, several hypotheses have been formulated regarding the formation of the pragser wildsee/ lago di braies. although it was clear that the lake was dammed by debris deposits, their origin was controversial. it was especially the hilly valley bottom morphology downriver of the lake itself that caused speculations. according to damian (1899), hantke (1983) and heiss (1992), a huge debris flow fan, spreaded from the riedl valley (figs. 1, 2), together with smaller landslides and rock falls gave rise to the damming of the lake. another hypothesis considered the wide deposits as glacial (dal piaz 1930; pia, 1937) or composed of landslide masses subsequently transported and rearranged by a glacier (klebelsberg, 1927, 1935, 1956; castiglioni, 1964; engelen, 1972). abele (1974) instead assumed that pragser wildsee/lago di braies was dammed by a massive rock slope failure event. recently, the deposits have been described more in detail by furlanis (2013) and in the comments to the recently published geological carg map sheet 016 toblach/dobbiaco (gianolla et al., 2018). the reclassification of deposits previously misidentified as having origins other than landsliding has been done commonly in the last decades (e.g. spreafico et al., 2018). here, we describe the results of an extensive fieldwork, including sedimentological, morphological analyses and dating of the rock avalanche in the prags valley. 2. methods field mapping was conducted on a scale of 1:5000 using topographic maps and airborne laserscan images in 10 m resolution provided by the autonomous province of bolzano south tyrol. geometric calculations including volume estimations were made with autocad 2014. the estimations of the deposit thickness is based on the information from a 20 m long drill core conducted by the geological survey of south tyrol (fig. 3). for exposure dating with 36cl in the proximal sector of the rock avalanche, the surfaces of four boulders were sampled (tab.1). sample preparation is described in ivy-ochs et al. (2009). 36cl and natural cl (isotope dilution; ivy-ochs et al., 2004) were determined with https://doi.org/10.26382/amq.2020.07 184 ostermann m. et al. accelerator mass spectrometry (synal et al., 1997). major element and minor concentrations (tab. 2) were used to determine 36cl production rates (alfimov & ivyochs, 2009 and references therein). the radiocarbon age published by irmler (2003) were re-calibrated with oxcal 4.3 (bronk ramsey, 2009). 3. geological framework the prags valley/braies valley is located in the northeastern part of the dolomites, which are part of the southern alps. the dolomites consist mainly of the marine sediments of the upper permian and triassic periods, which were deposited in tropical to subtropical climate on permian volcanic rocks and, as in the vicinity of the puster valley, on metamorphic crystalline basement rocks (brandner et al., 2007b) (fig. 2). regarding to the pragser wildsee rock avalanche there are three lithologies within the permo-mesozoic sediment succession (fig. 2) which are important to describe more in detail, because these are the formations involved in the phenomenon. the buchenstein formation: pelagic basin sediments that interlock with the clinoforms of the prograding ladinian carbonate platforms (brandner et al., 2007b). the limestones of the buchenstein fm. is well-bedded (cm-dm), partly bituminous and laminated (keim, 2008). thin volcanogenic clastics “pietra verde“-layers (cm-dm) are interbedded decreasing the mechanical properties of the whole succession. the schlern formation consists of preand postvolcanic carbonate rocks, which formed mighty reefs or their clinoforms in the ladinian. the reef slope interlocks with the basin sediments of the buchenstein formation. the rocks were formed in a tropical subtropical climate (muttoni et al., 2003) in marine shallow waters and later dolomitized, whereby the coarse banking is relatively unclearly recognizable (pia, 1937). the fernazza formation corresponds essentially to the basin-deposits of the proximal, alkaline volcanic activity in the dolomites. the most common lithotypes are volcanoclastic, turbiditic, massive sandstones, homogeneous or graded, dark green to blackish colour, greenish tuffites of the "pietra verde" type, siliceous tuffites, hyaloclastites and laminated calcareous siltites. laminated, siliceous calcareous lutites, hemipelagites and marls are also found in between. at the top of the fig. 1 distribution of major mass movements in the western dolomites, italy, indicated on a hill-shade image (acc. to ostermann & gruber, 2014, based on brandner et al., 2007a). dsgsd stands for deep-seated gravitational slope deformation. the insert-map shows the assumed maximum extent of the rock avalanche with removed post-failure accumulations (mainly debris flow fans). the red line represents the scarp. 185 characteristics and dating of the rock avalanche at pragser wildsee/lago di braies (dolomites, italy) fig. 2 geological map of prags valley (modified detail of the carta geologica d'italia alla scala 1:50.000, map sheet 016 toblach/ dobiaco). in magenta the nowadays outcropped debris accumulations are highlighted. a-c indicate the three different accumulation areas mentioned in the text. scs: st. kassian fm.; scia: schlern fm. in reef facies; imf: fernazza fm.; dcs: kassianer fm.; buc: buchenstein fm.; mtb: ambata fm.; don: dont fm.; wen: wengen fm.; the full legend can be found in gianolla et al., 2018. the black line indicates the thrust fault separating the permo-mesozoic sediments succession in the south from the metamorphic basement in the north. the green line indicates the orientation of the schematic cross-section (insert figure, 2 x super-elevated). fig. 3 hillshade image of the prags valley with indicated rock avalanche accumulations in magenta: light magenta for the maximum extent of the accumulations, dark magenta indicates the accumulations as drawn in the geological map. red line: main scarp. the yellow circle indicates the location of a 20m long drilling, conducted by the south-tyrolian geological survey. the insert photo, view towards north, shows the pragser wildsee in the foreground and the riedl valley and the prags valley with indicated debris accumulations in the background. the insert-map shows a detail of the hillshade with 10 m contour lines and the sampling points for surface exposure dating with obtained 36cl ages. 186 ostermann m. et al. fernazza fm. fine-grained calcarenites and marly limestones are present. 4. characterisation of the rock avalanche scarp and the slope failure accumulations 4.1. characteristics of the scarp area the scarp area of the rock avalanche is located in the upper part of the riedl valley at elevations between about 2000 and 2350 m a.s.l. (fig. 3). schlern fm. is the prevalent formation in the crown area which is also reflected in the lithological composition of the debris accumulations. along the southern and south-western flank of the riedl valley, here a well-banked schlern fm. is exposed. the banks dip with � 60° towards s-sw (more or less parallel to the northern slope) represented a predisposing factor for a dip slope slide (e.g. abele, 1974; hoek & bray, 1981). the schlern fm. also shows pronounced jointing and partly karst-widened cracks, which were already mentioned by pia (1937). there are several tectonic lineaments, in different orientations, nearby the scarp area (fig. 2) and many rock slope failures show these tectonic constrains (e.g. stead & wolter, 2015), but we could not find convincing evidence for tectonic lineaments that delimited the failed rock mass here. according to the map of van husen (1987) the lgm-ice surface in the prags valley was between 2300 and 2400 meters a.s.l., which hints that the scarp area at least was partly covered with ice during this period. 4.2. characteristics of the rock avalanche accumulation area the accumulation area of the rock avalanche at pragser wildsee can be divided into three distinguishable areas (a-c) (fig. 2 & 3). a) area a refers to the proximal deposits in the riedl valley. here the deposits are mainly (>95%) composed of schlern fm. blocks, which are strongly weathered and can reach several tens of cubic meters in volume lying on top of finer material (carapace facies). the accumulations are partly overlaid by deposits of secondary landslides coming from the north (shallow landslides, slope debris). in the southern part of the riedl valley, debris flows accumulation overlay the rock avalanche deposit, mainly consisting of reworked and relocated landslide material. b) accumulation at area b (fig. 2 & 3) is located on the west side of herrstein and forms a proximal surge barrier with a maximum total thickness of about 150 m, which was created under high-energy conditions on the opposite slope. the sediments here consist of a massive, matrix-supported diamict with a loose and fig. 4 hillshade image of the outer prags valley with highlighted toma hills and debris ridges (magenta). the arrows indicate the travel path of the rock avalanche. on the insert photo, view towards southwest, the scarp is indicated with a dashed line in magenta and the accumulations with a dashed with line. in the foreground the toma hills and ridges are accentuated. partially open framework structure. blocks and megablocks of massive dolomites are found, the matrix is gravelly and slightly sandy. all components are from angular to sub-rounded. it represents the main accumulation zone of the rock avalanche and it is primarily responsible for the damming of the lake. the morphology can be described as very unsettled. on the surface, there are dark weathered blocks of schlern fm., up to several 10 cubic metres in size, in nonexposed areas the blocks are angular. landslide material is also found on the nw shore of the lake below the debris cone from the riedltal valley, which was confirmed by sediment-echographic investigations (irmler, 2003). c) area c represents the distal part of the rock avalanche deposits in the prags valley and it is primarily characterized by the presence of undulating relief known as toma hills. their genesis is directly connected to the rock slope failure event. the prags valley therefore is a very beautiful example of a socalled toma landscape (penck & brückner, 1901; abele, 1974). in many places the landslide material is overlain by debris flow and alluvial material from the side valleys, but can be traced back up to the sports 187 characteristics and dating of the rock avalanche at pragser wildsee/lago di braies (dolomites, italy) field north of the village of schmieden/ferrara (fig. 4). within the accumulation area c the thickness of the deposit was estimated to be only 5 m. beside some blocks of schlern fm. in meter scale, there are mostly poorly sorted, angular components in cm-dm size. the average size is therefore finer than the material at accumulation area b. contrary to older assumptions (e.g. klebelsberg, 1935; pia, 1937; castiglioni, 1964; abele, 1974) the rock avalanche material in the prags valley was not transported by a glacier out of the valley. there is no evidence of glacial transport, nor of glacial overlay. 4.3. geometrical characteristics of the pragser wildsee rock avalanche rock avalanche deposits exposed at the surface cover an area of ~1.7 km2. taking into account those parts of the avalanche that are buried by alluvial fans, talus slopes and colluvium, an area of ~3.5 km2 was estimated. the distance from the upper limit of the detachment scarp (2330 m a.s.l.) to the most distal toma hill (1180 m a.s.l.) is 8.5 km, yielding a fahrböschung angle of 8°. according to our calculation based on a digital elevation model, the total volume of rock avalanche deposits is 36 million m³, so a volume between 30 and 40 million m³ can be given. 5. dating the pragser wildsee rock avalanche for exposure dating with 36cl, in the proximal sector of the rock avalanche (accumulation area b), the surfaces of four boulders of schlern dolomite were sampled (locations in insert map in fig. 3). unfortunately, the distal sector of the avalanche deposit (accumulation area c) with transversal ridges and toma hills is devoid of suitable boulders (those lying well above the enclosing sediment). we obtained the following exposure ages: 7.82 ±0.45 ka (prag1), 8.18 ±0.55 ka (prag2), 8.89 ±0.76 ka (prag3), and 8.28 ±0.64 ka (prag4). sample site and dating information is given in tab. 1 and the chemical composition of the samples in tab. 2. the average age of 8.3 ±0.7 ka indicates an early holocene age for the rock avalanche event. tab. 1 sample information, ams data and calculated exposure ages. exposure ages were calculated using stone et al.(1996, 1998) production rates (see also alfimov & ivy-ochs, 2009) and lal /stone scaling (stone, 2000). no erosion correction was made. tab. 2 chemical composition of analysed rock samples, major oxides in wt %, trace elements in ppm. tab. 3 major parameters of the rock avalanches at pragser wildsee and obernberg. at the base of a 12.1 m long drill core a tree needle was found during the investigations of the lake deposits by irmler (2003). its age was determined by 14c dating. the age was determined to 6504 ±47 uncal. years bp which corresponds to a calibrated 14c age of 7410 ±100 cal. years bp. this age can be regarded as the minimum age of the lake and therefore as a minimum age of the landslide. 6. discussion the pragser wildsee/lago di braies rock avalanche shows conspicuous similarities to the obernberg rock avalanche (ostermann et al., 2012) situated about 60 km in the nw of the prags valley within the brenner mesozoic (eastern alps, austria). both rock avalanches show runout paths with a runup/impact on the opposite slope and a further propagation within a narrow valley that changes its orientation several times. the conceptual model of the kinematics is discussed in ostermann et al. (2012) and in tab. 3 we summarize the basic parameters of both rock avalanches. the age of 8.3 ±0.7 ka of the pragser wildsee rock avalanche and the 8.6 ±0.6 ka obernberg rock avalanche may suggest a relation with the “8.2 ka cooling event” (cf. rohling & pälike, 2005), but for more detailed discussion about this potential relationship, refer to ostermann et al. (2012). nevertheless, we underline the importance of strong tectonic events as triggers for holocene rock avalanches (e.g. ambrosi & crosta, 2006; prager et al., 2008) and there are recent (e.g. 2008 wenchuan earthquake, guo et al., 2015) and historic (e.g. 1348 villach earthquake, brandt, 1981) examples for earthquake triggered landslides. 7. conclusions 1 according to the results of surface exposure dating of boulders we think that the pragser wildsee rock avalanche occurred 8300 ±700 years ago; this age is supported by a 14c minimum age of 7410 ±100 a cal bp of organic remnants from a drill core out of the backwater sediments within the pragser wildsee (irmler, 2003). 2 the pragser wildsee rock avalanche is one of the few dated mass-wasting event in the alps that potentially was associated with the 8.2 ka climatic cooling. the precise nature of the 8.2 ka event in the southern alps, however, is insufficiently documented to sustain speculations on a triggering cause of the rock avalanche under a particular climatic condition. 3 the distal 3.5 km of rock-avalanche deposits show an array of transverse ridges and toma hills. these were previously interpreted as moraines and kames. the internal fabric and nature of the sediment of the ridges are, however, incompatible with glacial moraines, but consistent with an origin from a rock avalanche. 4 several factors can be named as predisposing for the rock avalanche at pragser wildsee: the tectonic/ structural framework of a dip-slope layered rigid calcareous sediment succession, dissected by faults and joints, the destabilization in the upper part of the riedl valley due to pronounced facies interlocking and the karstification, especially in the schlern fm. acknowledgements this research was supported by autonome provinz bozen-südtirol provincia autonoma di bolzano alto adige, amt für hochschulförderung, universität und forschung, project: age inventory and analysis of catastrophic rock slope failures in south tyrol. the laboratory of ion beam physics, eth zurich, supported laboratory work, and ams measurements. special thanks goes to the team of the department of geology at the university of innsbruck. we thank monica ghirotti, heike schneider and an anonymous reviewer whose comments/suggestions helped improve and clarify this manuscript. references abele g. (1974) bergstürze in den alpen: ihre verbreitung, morphologie und folgeerscheinungen. wissenschaftliche alpenvereinshefte, 25, 1-230. alfimov v., ivy-ochs s. (2009) how well do we understand production of 36cl in limestone and dolomite? quaternary geochronology, 4, 462-474. ambrosi, c., crosta, g.b. (2006) large sackung along major tectonic features in the central italian alps. eng. geol., 83, 183-200. brandner r., gruber a., gruber j., keim l. (2007a) geologische karte der westlichen dolomiten 1:25.000, eds: autonome provinz bozen südtirol, amt für geologie u. baustoffprüfung, bozen/ kardaun, italien. brandner r., gruber a., keim l. (2007b) geologie der westlichen dolomiten: von der geburt der neothethys im perm zu karbonatplattformen, becken und vulkaniten der trias. geo.alp, 4, 95-121. brandt a. (1981) die bergstürze an der villacher alpe (dobratsch), kärnten/österreich: untersuchungen zur ursache und mechanik der bergstürze. ph.d. thesis, university hamburg, germany, 1-104. bronk ramsey c. (2009) bayesian analysis of radiocarbon dates. radiocarbon, 51, 337-360. carta geologica d´italia alla scala 1:50.000, map sheet 016 toblach/dobbiaco (2018). castiglioni g.b. (1964) sul morenico stadiale delle dolomiti consoglio nazionele delle ricerche. centro di studio per la geografia fisica (con una carta fuori testo in scala 1:125.000), 1-16, padova, italia. dal piaz g. (1930) richerche geomorfologiche nell´alto adige orientale. studi trentini di scienze naturali, xi, 3, 1-27. damian j. (1899) seestudien. lago di serraia, lago delle piazze, pragser wildsee und antholzer see. abhandlungen der k. k. geographischen gesellschaft, i, 77-89. engelen g.b. (1972) a limnological reconnaissance study of lago di braies ("pragser wildsee") dolomites, n. italy. communications of the institute of earth sciences, a/1, amsterdam, netherlands, 163. furlanis s. (2013) risposta dei sistemi deposizionali 188 ostermann m. et al. ostermann m., gruber a. (2014) the major mass movements of the western dolomites (italy); geophysical research abstracts, 16, egu2014, 4972. penck a., brückner e. (1901) die alpen im eiszeitalter, 1-3, springer, leipzig, germany, pp. 1199. pia j. (1937) stratigraphie und tektonik der pragser dolomiten in südtirol. selbstverlag des verfassers, wien, 1-248. prager c., zangerl c., patzelt g., brandner r. (2008) age distribution of fossil landslides in the tyrol (austria) and its surrounding areas. nat. hazards earth syst. sci., 8, 377-407. rohling e.j., pälike h. (2005) centennial-scale climate cooling with a sudden cold event around 8,200 years ago. nature, 434, 975-979. spreafico m.c., wolter a., picotti v., borgatti l., mangeney a., ghirotti m. (2018) forensic investigations of the cima salti landslide, northern italy, using runout simulations. geomorphology, 318, 172-186. stead d., wolter a. (2015) a critical review of rock slope failure mechanisms: the importance of structural geology. journal of structural geology, 74, 1-23. stone j.o.h. (2000) air pressure and cosmogenic isotope production. journal of geophysical research, b: solid earth, 105 (b10), 23753-23759. stone j.o.h., allan g., fifield l., cresswell r. (1996) cosmogenic chlorine-36 from calcium spallation. geochimica et cosmochimica acta, 60, 679-692. stone j.o.h., evans j.m., fifield l.k., allan g.l., cresswell r.g. (1998) cosmogenic chlorine-36 production in calcite by muons. geochimica et cosmochimica acta, 62, 433-454. synal h.-a., bonani g., döbeli m., ender r.m., gartenmann p., kubik p.w., schnabel ch., suter m. (1997) status report of the psi/eth ams facility. nuclear instruments and methods in physics research section b: beam interactions with materials and atoms, 123, 62-68. van husen d. (1987) die ostalpen in den eiszeiten. populärwissenschaftliche veröffentlichungen der geol. bundesanstalt, wien, 1-24. continentali dell’area alpino dolomitica alle variazioni climatiche a scala del millennio durante l’ultima transizione glaciale interglaciale (pleistocene sup. p.p. olocene inf.). tesi di dottorato inedita, università di ferrara, italia, 1-106. gianolla p., morelli c., cucato m., siorpaes c. (2018) erläuterungen zur geologischen karte von italien im maßstab 1:50.000, blatt 016 toblach, pp. 294. guo d., he c., xu c., hamada m., (2015) analysis of the relations between slope failure distribution and seismic ground motion during the 2008 wenchuan earthquake. soil dyn. earthq. eng., 72, 99-107. hantke r. (1983) eiszeitalter: die jüngste erdgeschichte der schweiz und ihrer nachbargebiete.band 3: westliche ostalpen mit ihrem bayerischen vorland bis zum inn-durchbruch und südalpen zwischen dolomiten und mont blanc. 1-730, ott, thun, switzerland. heiss c. (1992) der pragser wildsee. smaragd der dolomiten. verlag la commerciale borgogno, bozen, italy, 1-32. hoek e., bray j.w. (1981) rock slope engineering (revised third edition). institute of mining and metallurgy, london, pp.358 irmler r. (2003) seesedimente als natürliches archiv zur erstellung eines murkalenders am beispiel des pragser wildsees (norditalien). ph.d. thesis, friedrich-schiller-universität jena, germany, 1-96. ivy-ochs s., von poschinger a., synal h.-a., maisch m. (2009) surface exposure dating of the flims landslide, graubünden, switzerland. geomorphology, 103, 104-112. ivy-ochs s., synal h.-a., roth c., schaller m. (2004) initial results from isotope dilution for cl and 36cl measurements at the psi/eth zurich ams facility. nucl. instrum. methods phys. res. b 223-224, 623 -627. keim l. (2008) geologie im gebiet schlern seiser alm: vom tethysmeer zum gebirge. gredleriana, 8, 25-46. klebelsberg r.v. (1927) beiträge zur geologie der südtiroler dolomiten. zeitschrift der deutschen geologischen gesellschaft, 79, 280-354. klebelsberg r.v. (1935) geologie von tirol. borntäger, berlin, germany, pp.187. klebelsberg r.v. (1956) südtiroler geomorphologische studien: das pustertal (rienz-anteil). schlernschriften, 151, 1-218. muttoni g., kent d.v., garzanti e., brack p., abrahamsen n., gaetani m. (2003) early permian pangea „b“ to late permian pangea „a“. earth and planetary science letters, 215, 379-394. ostermann m., sanders d., ivy-ochs s., alfimov v., rockenschaub m., römer a. (2012) early holocene (8.6 ka) rock avalanche deposits, obernberg valley (eastern alps): landform interpretation and kinematics of rapid mass movement. geomorphology, 171, 83-93. 189 characteristics and dating of the rock avalanche at pragser wildsee/lago di braies (dolomites, italy) ms. received: july 10, 2020 revised: august 18, 2020 accepted: september 8, 2020 available online: november 30, 2020 190 imp. sardella iittaalliiaann pplliioo--pplleeiissttoocceennee mmaammmmaall bbiioocchhrroonnoollooggyy aanndd ccoorrrreellaattiioonn wwiitthh mmaarriinnee sseeqquueenncceess:: tthhrreeee ccaassee ssttuuddiieess rraaffffaaeellee ssaarrddeellllaa11,, cchhiiaarraa aannggeelloonnee22,, ggiiaannccaarrlloo bbaarriissoonnee22,, ccllaauuddiiaa bbeeddeettttii11,, eemmaannuueellee ddii ccaannzziioo11,, ffeeddeerriiccaa mmaarrccoolliinnii22 && eennrriiccoo ssqquuaazzzziinnii33 1dipartimento di scienze della terra, università degli studi “la sapienza”, piazzale a. moro, 5 – 00185 rome, italy; 2dipartimento di scienze geologiche, università degli studi roma tre – largo s. leonardo murialdo 1 – 00146 rome, italy; 3museo paleontologico “ex chiesa di s. tommaso”, vico catina, 24 – 05100 terni, italy. e-mail address: raffaele.sardella@uniroma1.it summary the use of the biochronological units, based on the occurrence and evolutionary degree of the mammals, in the correlation between marine and continental sequences, in some cases enables a more detailed definition of the age of the sequences, but in other cases shows a more complex framework. in this paper three case studies will be pointed out: mandriola (sardinia, early pliocene-middle pliocene boundary), lower valdarno (tuscany – plio-pleistocene boundary) and tiberino river basin (umbria pliocene pleistocene boundary). biochronological criteria can be considered a very useful tool to infer age determination in the case of mandriola fossiliferous site. the interpretation of the marine and non marine fossil record of lower valdarno and tiber river basin lead to two different scenarios: 1) the italian peninsula can be considered as a refugium area for the pliocene taxa, which survived until the earliest pleistocene; 2) the age of deposits previously referred to early pleistocene has to be considered older (late pliocene). riassunto le unità biocronologiche, basate sulla comparsa e sul grado evolutivo delle diverse associazioni a mammiferi, rappresentano un importante strumento per la correlazione tra le sequenze marine e quelle continentali. in alcuni casi questa metodologia di lavoro porta a una maggiore definizione dell’età del deposito e della sequenza stratigrafica; in altri, invece, le unità biocronologiche mettono in evidenza un quadro più complesso. in questo lavoro vengono presi in considerazione tre casi di studio: mandriola (sardegna passaggio pliocene inferiore-medio), il valdarno inferiore (toscana – passaggio plio-pleistocene) e il bacino tiberino (umbria – passaggio pliopleistocene). i criteri biocronologici si sono rivelati uno strumento assai utile per definire con maggior dettaglio l’età di un deposito fossilifero nel caso del sito di mandriola. l’interpretazione dei ritrovamenti paleontologici provenienti dalle successioni marine e continentali del valdarno inferiore e del bacino tiberino conducono alla definizione di due scenari: 1) la penisola italiana come area rifugio per taxa pliocenici, qui sopravvissuti sino alle prime fasi del pleistocene; 2) l’età di depositi in precedenza attribuiti al pleistocene inferiore deve essere considerata più antica (pliocene superiore). keywords: biochronology, marine/continental correlation, fossil vertebrates, plio-pleistocene parole chiave: : biocronologia, correlazioni marino-continentale, vertebrati fossili, plio-pleistocene il quaternario italian journal of quaternary sciences 1166(1), 2003, 15-20 iinnttrroodduuccttiioonn in 1997 gliozzi et al. published an integrated biochronological framework based mainly on mammal faunal assemblages and their evolutionary degree. such a biochronological framework for pliocene and pleistocene can be considered a first step for correlating continental and marine sequences. the comparison between biochronological and biostratigraphical data enables in some cases a more detailed correlation of the sequences, while in other cases such a correlation does not seem to fit perfectly. in this paper three case studies will be presented, illustrating those two situations. 11)) iinnffeerrrriinngg aaggee ccoonnssttrraaiinnttss ttoo mmaarriinnee ssuucccceessssiioonnss bbyy mmeeaannss ooff ccoonnttiinneennttaall ffoossssiill vveerrtteebbrraatteess:: tthhee mmaannddrriioollaa ffoossssiilliiffeerroouuss ssiittee ccaassee ssttuuddyy age determination of the various formations outcropping in the sinis peninsula (western sardinia, italy) and their stratigraphical correlations have been for a long time a matter of debate. actually, each formation outcrops in a very limited area, most of the time they show no visible stratigraphical continuity or heteropy with other formations, and usually lacks significant fossils. nonetheless, a revision of the lagomorph and rodent content of the mandriola fossiliferous site (southern coast of the capo mannu peninsula, northern portion of the sinis peninsula; fig. 1) fixed a constraint to the age of the enclosing formations. the fossiliferous layer consists in a lens (3 m thick in its central part and approximately 10 m long) of silt and sands accumulated in a coastal lagoon (esu, 1986). the lens lies at the base of the capo mannu fm., consisting of various sand complexes of aeolian origin (pecorini et al., 1974; carboni & lecca, 1995). the capo mannu fm. overlies the shallow water marine limestones of the calcari di mandriola fm. (fig. 1), whose depositional facies becomes shallower from bot16 r. sardella et al. tom to top. all the complex represents a transition from a marine littoral environment to a continental aeolian one (carboni & lecca, 1995). the non-marine molluscs found in the deposit unfortunately cover too wide a stratigraphical range (pliocene; esu, 1986) to be useful for age determination. fossil vertebrates of the lagoonal sediments were at first illustrated in a preliminary note by pecorini et al. (1974), who inferred an early pliocene age (ruscinian, mn14; for a synoptic mn zones mammal ages chronostratigraphic chart, see esu, 1999) for the deposit due to the presence of the murid rhagapodemus hautimagnensis. this opinion was in later years reconsidered by other palaeontological studies (lópez martínez & thaler, 1975; esu & kotsakis, 1985). on the other hand, regional stratigraphy data assigned the mandriola fossiliferous site to middle pliocene (carboni & lecca, 1995). the new systematic attribution of one faunal element (the murid rhagapodemus azzarolii; angelone & kotsakis, 2001) has been one of the factors that led to the reconsideration of the age of the deposit. r. azzarolii underwent only slight morphological and morphometric modifications if compared with its continental ancestor (r. ballesioi mein & michaux, 1970): that may demonstrate that its colonisation of sardinia occurred a short time before the deposition of the lagoonal sediments (for a synthesis on insular environment induced modifications on vertebrates see azzaroli, 1982). the temporal distribution of r. ballesioi in central and western europe covers part of mn14 to early mn15 (middle-upper zanclean), fixing a lower age boundary for its arrival on the island. an upper limit could be established by the presence of prolagus aff. p. depereti, derived from p. depereti lópez, 1975, only known in late ruscinian assemblages (mn15, late early pliocene – earliest middle pliocene). for these reasons, the arrival of these faunal elements in sardinia and the age of the mandriola fossiliferous site is considered to be the zanclean-piacenzian boundary (angelone & kotsakis, 2001). the difficulty in using a common biochronological tool (such as evolutionary degree of faunal elements) to compare continental faunas and insular ones, in this case has fortunately been avoided. 22)) nneeww ppeerrssppeeccttiivveess iinn lloowweerr vvaallddaarrnnoo ssttrraattiiggrraapphhyy bbyy mmeeaannss ooff mmaammmmaall ffaauunnaass in lower valdarno area (tuscany, italy) sediments spanning from early pliocene to late pleistocene – holocene outcrop. the marine pliocene cycle deposits are represented by the “sabbie gialle” fm outcropping either on the left and on the right-hand side of the arno (fig. 2). the end of this cycle is commonly considered to be middle pliocene in age, as attested by the micropaleontological content of the deposits on the left-hand side of the arno river (bossio et al., 1981). in this area the transgressive overlying sediments of the “sabbie e argille ad arctica islandica” fm are discordant over the sabbie gialle fm. and represent the early pleistocene marine ingression. another interpretation is suggested by the recent study of casa sgherri (santa croce sull’arno, pisa) mammal fauna and of the findings at vinci, in the surroundings of fucecchio (firenze), on the right-hand side of the arno, in continental sediments correlated to the post-pliocene marine cycle of the left-hand side (fig. 2). germanomys sp. (arvicolidae, rodentia) has been found in the “conglomerati di vinci”. it is related to middle to early late pliocene (mn15b-16b) (fejfar, 2001). together with germanomys, remains of e. ex gr. e. stenonis-senezensis have been recovered. such a finding, even if without a specific attribution, reduces the time span to late pliocene (costa san giacomo-olivola f.u.), since either e. stenonis cocchi and e. senezensis prat are widespread in western europe in sites correlated with late pliocene and earliest pleistocene (alberdi et al., 1998). a few km westward in the sediments of the massarella unit, related to those of vinci, the casa sgherri local fauna has been found (marcolini et al., 2000; marcolini, 2001, marcolini, in press). large and small mammals have been recovered and the assemblage seems to be related to the late pliocene. as to large mammals, the contemporary presence of enhydrictis ardea (bravard), acinonyx pardinensis (croizet & jobert), sus strozzii meneghini and macaca sylvana florentina (cocchi) has important biochronological meanings since such an assemblage indicates a time lapse comprised between the costa s. giacomo f.u. and the olivola f.u. as to small mammals, mimomys ostramosensis janossy & meulen and fig. 1 location of the mandriola fossiliferous site and lithological section of the outcrop. 1. calcari di mandriola fm. limestones, deeper water facies; 2. calcari di mandriola fm. limestones, shallower water facies; 3. first dunar complex of the capo mannu fm.; p.s.l.: present sea level; dv: vertebrate deposit (not in scale) (from carboni & lecca, 1995, modified). mimomys pitymyoides janossy & meulen are associated in several late villanyian faunas (see discussion in: marcolini, 2001) while all the three species m. ostramosensis, m. pitymyoides and m. pusillus (méhély) have been recently recovered together in some late villanyian localities (i.e. przymilowice 3, poland) (nadachowski, 2001). if we consider this piece of information, together with large mammals biochronological information the assemblage can be correlated with the costa s. giacomo to olivola f.u., late pliocene in age (marcolini, in press). on the basis of the fossil content, the basal portion of the massarella unit and the “conglomerati di vinci” must be attributed to the late pliocene (marcolini, 2001; in press), in accordance to the recent interpretation of the lower valdarno area suggested by zanchetta et al. (1995), zanchetta & mazza (1996) and marcolini et al. (2000). these authors suggest that the post-middle 17italian plio-pleistocene mammal biochronology ... pliocene cycle in the lower valdarno is not entirely attributable to the early pleistocene but it could be antedated to the late pliocene. indeed, zanchetta & mazza (1996), on the basis of the finding of anancus arvernensis (croizet & jobert) in sediments disconformably overlying the sabbie gialle fm. and laterally continuous with the sabbie e argille ad arctica islandica fm., suggest that the lowermost part of this new cycle may be older than the base of the early pleistocene. the authors suggested two scenarios to justify this finding: the first hypothesis is that anancus arvernensis, whose lad in italy is in the costa san giacomo f.u., survived until the pleistocene olivola f.u. (now correlated with late pliocene; torre et al., 1996). the second one is that the base of the sabbie e argille ad arctica cycle is older than previously believed, i.e. late pliocene. the authors saw the second scenario as the most acceptable. fig. 2 location of the lower valdarno fossiliferous sites and schematic sketch of the relationships of the left-hand and right-hand plio-pleistocene deposits. 33)) tthhee ssoouutthh--wweesstteerrnn bbrraanncchh ooff tthhee ttiibbeerr rriivveerr bbaassiinn ((uummbbrriiaa)):: aann ooppeenn aaiirr llaabb ffoorr ccoorrrreellaattiinngg ccoonnttiinneennttaall ttoo mmaarriinnee ddeeppoossiittss the tiber river basin is the largest intramontane basin of the apennine, in which non marine sedimentation took place from pliocene up to holocene. modern studies give an updated picture of stratigraphy and palaeontology of i ts southwestern branch, where the sedimentary successions widely crop out. stratigraphy was depicted, among others, by conti & girotti (1978), ambrosetti et al. (1989, 1995a, 1995b), basil ici (1995, 1997), abbazzi et al. (1997). the pliocene and early pleistocene deposits considered in these studies are referable to three lithostratigraphic units (fig. 3): 1. the “fosso bianco” formation, a lacustrine unit, middle pliocene – late pliocene in age. 2. the “s. maria di ciciliano” formation, which unconformably lies above the “fosso bianco” formation. it consists of sediments laid down in a fluvial environment characterised by different facies: meandering channel deposits with trough cross stratification, lake and swamp deposits, and paleosols. this formation has been referred to the early pleistocene but, as discussed in this work, the palaeontological data suggest the occurrence of late pliocene elements. 2.the “chiani-tevere formation”, a marine unit widely outcropping along the middle tiber valley and bordering on the “s. maria di 18 ciciliano” formation by means of the interfingering of their sediments. the “chiani-tevere” formation is mostly early pleistocene, with only in a few sites a gelasian age. the total thickness exceeds 300 m and the heteropy to the “s. maria di ciciliano” formation occurs where its strata are santernian in age (mancini et al., in press). up to 15 years ago the only important large mammal finding in the south-western branch of the tiber river basin was the almost complete skeleton of stephanorhinus etruscus (falconer) coming from capitone (ambrosetti, 1972). in the following years a new research campaign enabled a more detailed definition of the stratigraphy of continental deposits outcropping in the area as well as the discovery of many vertebrate sites. in the area near terni and montecastrilli the “s. maria di ciciliano” formation outcrop (basilici, 1995; 1997). this formation is heteropic to the marine chianitevere formation, which is mostly of santernian age (mancini et al. in press), thus it has traditionally be referred to early pleistocene. recent discoveries in the terni area suggest the occurrence of more fossiliferous levels different in composition and age. in the fluvial deposits exposed in this area three mammal faunal assemblages have been collected until now. the older one comes from torre picchio and includes a great number of vertebrates, coprolites, freshwater molluscs, ostracods and plants (woods, fruits and seeds) (girotti et al., in press). vertebrates are represented by large and small mammals, rare birds, reptiles, amphibians and some fishes. among the mammals prolagus sp. oryctolagus lacosti (pomel), mimomys medasensis michaux, ?mammuthus meridionalis (nesti), stephanorhinus cf. s. etruscus (falconer), equus stenonis cocchi, sus strozzii meneghini, eucladoceros dicranios (nesti) vel ctenoides (nesti), axis nesti i (major), bovoidea (?gallogoral sp.), leptobos vallisarni merla vel l. etruscus (falconer), mustelidae indet. (?baranogale sp.), canis cf. c. arnensis del campana, ?homotherium crenatidens (fabrini) have been found. this faunal assemblage shows transitional features between costa s. giacomo f.u. and olivola f.u., with the contemporary occurrence of mimomys medasensis (recorded herein for the first time outside spain), ?baranogale sp. (similar in size with the middle villafranchian european specimens), ?gallogoral sp., axis nestii and leptobos etruscus. another faunal assemblage comes from villa s. faustino and colle s. andrea, near massa martana (ambrosetti et al., 1995a) and it is referable to the late villafranchian. at villa s. faustino the fossil mammals mainly come from the sandy deposits (ambrosetti et al., 1995; sardella et al., 1995) and include: castor sp., elephantidae indet., stephanorhinus etruscus, equus stenonis, sus strozzii, axis nestii, cervidae indet., leptobos sp. (vallisarni vel etruscus), megantereon cultr idens (cuvier, partim). at colle s. andrea pachycrocuta cf. p. brevirostris (aymard) cervidae indet., leptobos cf. l. vallisarni, castor sp. occur. the paleontological analysis of these sites suggests they are coeval and to refer the faunas to the tasso f.u. the third assemblage comes from colle s. umano and includes large mammals referable to the late villafranchian-earliest galerian (early pleistocene). the faunal list includes a large sized equid referable to equus ex gr. e. bressanus-suessenbornensis, a bovid with bisontine features (bison vel leptobos), hippopotamus antiquus desmarest and axis eurygonos (azzaroli). the presence of different mammal faunas in the south-western branch of the tiber river basin suggests a more complex framework for the stratigraphy of the “s. maria di ciciliano” formation. the faunal assemblage coming from torre picchio shows more “archaic” features (mimomys medasensis, axis nestii, the possible r. sardella et al. fig. 3 location of the tiber river basin and schematic sketch of the stratigraphy: fa acquasparta formation (early pleistocene); 4, fsmc s. maria di ciciliano formation (early pleistocene-?late pliocene); fpn ponte naia formation (late pliocene); ffb fosso bianco formation (middle-late pliocene); ps pre-pliocene substratum. 19 occurrence of a middle sized bovid) compared to that from colle s. umano (axis eurygonos, large bison-like bovid, etc…), with typical early pleistocene elements. biochronological considerations suggest a wider time span for the continental succession of “s. maria di ciciliano” formation (late pliocene-early pleistocene). the biochronology of this faunal assemblages and its significance in the stratigraphy of the tiber river basin is discussed in detail in girotti et al. (in press), where two possibilities have been pointed out: to assign a late pliocene age to the fossiliferous deposit, with the first occurrence of species that will be very common during the early pleistocene times (e.g. axis nestii, leptobos etruscus) or to consider peninsular italy as a refugium area, in which some vertebrates, molluscs and plants of pliocene origin survived in the early pleistocene (see conclusions). ccoonncclluussiioonnss the use of the biochronological units, based on the occurrence and evolutionary degree of mammals, for the correlation of marine and continental sequences, in some cases enables a more detailed definition of the age of the sequences, but in other cases shows a more complex framework. the mandriola fossiliferous site is an emblematic example of how biochronological criteria can be successfully used to infer age determination. moreover, in this case it has been possible to apply continental european biochronological framework to the study of insular faunas. the interpretation of the marine and non marine fossil record of lower valdarno and tiber river basin (related to the plio-pleistocene transition) lead to two different scenarios: 1) the italian peninsula can be considered as a refugium area for the pliocene taxa, which survived until the earliest pleistocene; 2) the age of deposits previously referred to early pleistocene has to be considered older (late pliocene). the latter interpretation fits well with the stratigraphy of the right-hand side of the lower valdarno and of the upper valdarno and also with the palaeomagnetic analyses of ambrosetti et al. (1975) and bedini et al. (1981) recognising the subchron reunion (2-2.2 ma) within the sediments of the “sabbie e argille ad arctica“ of the colline pisane. moreover, this interpretation is confirmed by our recent findings of vinci and casa sgherri that enable a correlation of the “conglomerati di vinci” and the massarella unit with the “sabbie e argille ad arctica”, since all of them bear mammals of the costa san giacomo-olivola f.u. the mammal faunas from the south-western branch of the tiber river basin show differences in composition and can be referred to costa s. giacomoolivola f.u. (torre picchio), tasso f.u. (villa s. faustino-colle s. andrea) and farneta f.u. (colle s. umano) respectively. such palaeontological data suggest a wider t ime span (late pliocene-early pleistocene) for the continental “s. maria di ciciliano” formation. an age attribution for this formation other than early pleistocene is therefore problematic, both from a geologic and a stratigraphic point of view. from the geological point of view, the “s. maria di ciciliano” formation is heteropic to the marine chiani tevere one, which is prevail ingly santernian in age and l ies unconformably on the middle pliocene cycle: only in some areas of structural lowering it passes inferiorly and continuously to late pliocene strata, but before the heteropic episodes. in order to find a solution to these still open problems a detailed analysis of the stratigraphy, of the local tectonics of the fossiliferous marine and non marine deposits, and the taphonomy of the mammal remains has to be considered. aakknnoowwlleeddggeemmeennttss we wish to thank two anonymous referees for their critical comments on the manuscript, t. kotsakis, o. girotti and m. mancini for the useful discussions and the suggestions. this work is supported by igag (istituto di geologia ambientale e geoingegneria) c.n.r. rreeffeerreenncceess abbazzi l., albianelli a., ambrosetti p., argenti p., basilici g., bertini a., gentili s., masini f., napoleone g. & pontini m.r. (1997) paleontological and sedimentological record in pliocene distal alluvial fan deposits at cava toppetti (todi, central italy). boll. soc. paleont. ital., 3366, 5-22. alberdi, m.t., ortiz-jaureguizar, e. & prado, j.l. (1998) a quantitative review of european stenonoid horses. j. paleont., 7722, 371-387. ambrosetti p. (1972) lo scheletro di dicerorhinus etruscus (falc.) di capitone (umbria meridionale). geol. romana, 1111, 177-198. ambrosetti p., basilici g., capasso barbato l., carboni m.g., di stefano g., esu d., gliozzi e., petronio c., sardella r. & squazzini e. (1995a) i l pleistocene inferiore nel ramo sud-occidentale del bacino tiberino (umbria): aspetti litostratigrafici e biostratigrafici. il quaternario, 88, 16-36. ambrosetti p., basilici g., ciangherotti a.d., codipietro g., corona e., esu d., girotti o., lo monaco a., meneghini m., paganelli a. & romagnoli m. (1995b) la foresta fossile di dunarobba (terni, umbria, italia centrale): contesto litostratigrafico, sedimentologico, palinologico, dendrocronologico e paleomalacofaunistico. il quaternario, 88, 465-508. ambrosetti p., carboni m.g., conti m.a., esu d., girotti o., la monica g.b., landini b. & parisi g. (1989) il pliocene ed il pleistocene inferiore del bacino del fiume tevere nell’umbria meridionale. geogr. fis. dinam. quatern., 1100 (1987), 10-33. ambrosetti, p., arias, c., bigazzi, g., bonadonna, f.p., de giuli, c., girotti, kukla, g., iaccarino, s., malatesta, a., mazzanti, r., radicati di brozolo, f. & trevisan, l. (1975) guide book meeting of the i.n.q.u.a. subcommission on mediterranean and black sea shorelines. pisa-perugia-tarquinia march, april 1975. angelone c. & kotsakis t. (2001) rhagapodemus azzarolii n. sp. (muridae, rodentia) from the pliocene of mandriola (western sardinia, italy). boll. soc. paleont. it., 4400: 127-132. italian plio-pleistocene mammal biochronology ... 20 azzaroli a. (1982) insularity and its effect on terrestrial vertebrates: evolutionary and biogeographic aspects. in: montanaro gall i tel l i e. (ed.). palaeontology, essential of historical geology: 193-203, ed. s.t.e.m. mucchi, modena. basilici g. (1995) sedimentologia della parte distale di una conoide alluvionale del pliocene superiore (bacino tiberino, umbria). il quaternario, 88, 37-52. basilici g. (1997) sedimentary facies in an extensional and deep-lacustrine depositional system: the pliocene tiberino basin, central italy. sedimentary geology, 110099, 73-94. bedini, e., bertolini, n., braschi, s., cotrozzi, s., gani, p. & niccoli, m.a., (1981) stratigrafia paleomagnetica di serie quaternarie e comparsa dell’arctica islandica nella zona di collesalvetti. geogr. fis. din. quat., 44, 135-137. bossio a., mazzanti r., mazzei r., menesini e., nencini c., salvatorini g. & ughi r., (1981) nuove osservazioni sulla stratigrafia delle formazioni plioceniche e pleistoceniche di casciana terme. atti del ix convegno della società paleontologica italiana, 3-8 ott. 1981, 55-90. carboni s. & lecca l. (1995) le pliocène de capo mannu (sardaigne occidentale): transition marin littoral continental dunaire. comptes rendu de l’academie de sciences paris, s. 2a, 332200, 12031210. conti a. & girotti o. (1978) il villafranchiano nel “lago tiberino”, ramo sud-occidentale: schema stratigrafico e tettonico. geol. romana, 1166, 67-80. esu d. & kotsakis t. (1985) les vertébrés et les mollusques continentaux du tertiaire de la sardaigne: paléobiogéographie et biostratigraphie. geol. romana, 2222 (1983), 177-206. esu d. (1986) la malacofauna continentale pliocenica di mandriola (sardegna occidentale): sistematica e paleobiogeografia. geol. romana, 2222 (1983): 2350. esu d. (1999) contribution to the knowledge of neogeneclimatic changes in western and central europe by means of non-marine mollusques. in: agustí j., rook l. & andrews p. (eds.). evolution of neogene terrestrial ecosystems in europe: 328-354, cambridge university press, cambridge. fejfar o. (2001) the arvicolids from arondelli-triversa: a new look. boll. soc. pal. it., 4400, 185-193. girotti o., capasso barbato l., esu d., gliozzi e., kotsakis a., martinetto e., petronio c., sardella r. & squazzini e. (in press) the section of torre picchio (terni, umbria, central italy): a villafranchian site rich in vertebrates, molluscs, ostracods and plants. riv. ital. paleont. strat. gliozzi e., abbazzi l., argenti p., azzaroli a., caloi l., capasso barbato l., di stefano g., esu d., ficcarelli g., girotti o., kotsakis t., masini f., mazza p., mezzabotta c., palombo m.r., petronio c., rook l., sala b., sardella r., zanalda e. & torre d. (1997) biochronology of selected mammals, molluscs and ostracods from the middle pliocene to the late pleistocene in italy. the state of the art. riv. ital. paleont. strat., 110033, 369-388. lópez martínez n. & thaler l. (1975) biogéographie, évolution et compléments à la systématique du groupe d’ochotonides piezodus-prolagus (mammalia, lagomorpha). bull. de la soc. géol. fr., s. 7, 1177 , 850-866. mancini m., cavinato g.p. & girotti o. (in press) il quaternario della media valle del tevere. mem. soc. geol. ital. marcolini, f. (2001) continental lower valdarno rodent biochronology and two new methods for the systematics of mimomys (arvicolidae, rodentia). thesis, pisa university: 133 pp. marcolini (in press) continental lower valdarno rodent biochronology and two new methods for the systematics of mimomys (arvicolidae, rodentia). atti soc. tosc. sci. nat., ser a marcolini, f., bonadonna, f.p., kotsakis, t., mazza, p. & zanchetta, g. (2000) preliminary data on the microand macromammal remains from casa sgherri, lower valdarno (tuscany, central italy). boll. soc. pal. it., 3399, 243-252. mein p. & michaux j. (1970) un nouveau stade dans l’évolution des rongeurs pliocènes de l’europe sud-occidentale. comptes rendu de l’academie de sciences paris, s. d, 222200, 2780-2783. nadachowski a. (2001) new important neogene and pleistocene mammal assemblages from poland. boll. soc. pal. it., 4400, 243-248. pecorini g., rage j.-c. & thaler l. (1974) la formation continentale de capo mannu, sa faune de vertébrés pliocènes et la question du messinien en sardaigne. rendiconti dei seminari della facoltà di scienze dell’università di cagliari, 4433 (1973) (suppl.), 305-319 . sardella r., di stefano g. & petronio c. (1995) the villafranchian mammal faunas from the tiber river basin (umbria, central italy). il quaternario, 88, 509-514. torre, d., albianelli, a., bertini, a., ficcarelli, g., masini, f., napoleone, g. (1996) paleomagnetic calibration of plio-pleistocene mammal localities in central italy. in: neogene and quaternary mammals of the palearctic, nadachowski a. & werdelin l. (eds.), acta zool. cracov., 3399, 559-570. zanchetta, g. & mazza, p. (1996) anancus arvernensis remains from the basal portion of the arctica islandica bearing marine deposits of lower valdarno. boll. soc. geol. it., 111155, 105-113 . zanchetta, g., petrucci, s., mazza, p. & rustioni, m. (1995) new villafranchian finds from the lower valdarno. il quaternario, 88, 449-456. r. sardella et al. ms. ricevuto il 20 ottobre 2002 testo definitivo ricevuto il 17 febbraio 2003 ms. received: october 20, 2002 final text received: february 17, 2003 imp. esposito llaattee qquuaatteerrnnaarryy sshhoorreelliinneess iinn ssoouutthheerrnn cciilleennttoo ((mmtt.. bbuullgghheerriiaa)):: mmoorrpphhoossttrraattiiggrraapphhyy aanndd cchhrroonnoollooggyy ccaarrmmeellaa eessppoossiittoo11,, ffrraanncceessccaa ffiillooccaammoo11,, rroobbeerrttaa mmaarrcciiaannoo11,, ppaaoollaa rroommaannoo11,, nniiccoolleettttaa ssaannttaannggeelloo11,, ffaabbiioo ssccaarrcciigglliiaa22 && ppaaoollaa ttuucccciimmeeii33 1dipartimento scienze della terra università di napoli federico ii 2dipartimento scienze della terra università della calabria 3dipartimento di geologia università di roma tre abstract a detailed geological and geomorphological survey of shorelines and continental deposits, cropping out along the carbonate coast between the mingardo river mouth and cala degli infreschi bay, was carried out. several erosional indicators of paleo-sea level stands were collected such as notches, wave-cut terraces and upper limits of lithophaga burrows. littoral sediments are often present on with these erosional features and are made up of sands and conglomerates which locally contain mollusc shells, red algae and corals. these evidence have been preserved along paleo-sea cliffs or inside coastal caves of prevalent karstic origin. the continental deposits, often associated with marine successions, are represented by eolian and colluvial deposits, paleosols and, inside the coastal caves, by speleothems and graviclastic breccias. in many localities these continental deposits contain lithic industries of palaeolithic age which can be considered as lower or upper chronological limits for the associated shorelines. geomorphological cut-cross relations, stratigraphic position and altimetrical correlation among continental and marine deposits were analysed in order to recognise both their relative chronology and the phases of coastal morphogenesis, linked to the interaction between sea level fluctuations and tectonic uplift. mineralogic analysis on paleosols was also carried out for paleoenvironmental reconstructions. moreover, th/u datings of speleothems, which directly cover or are buried by marine deposits, were carried out in order to give chronological constrains for the reconstruction. at least six orders of middle pleistocene marine terraces are present between 75 and 15 m a.s.l.; the complete flight of these terraces is only well preserved along the western part of the mt. bulgheria coast. between 10 e 3.5 m a.s.l. we recognised three other paleo-sea level stands, the youngest of which is represented by fossiliferous conglomerates and sands. the th/u age of the speleothem (90 ka bp) which is buried by these marine deposits and the th/u age of the speleothem which cover the marine sands (50 ka bp) allowed us to ascribe this shoreline to the oiss 5a. this correlation is supported by the mousterian age of the graviclastic breccia lying on them. riassunto e’ stato eseguito un rilevamento geologico e geomorfologico di dettaglio delle linee di riva e dei depositi continentali affioranti lungo il settore di costa carbonatica compreso tra la foce del fiume mingardo e cala degli infreschi. sono stati individuati diversi indicatori erosionali di paleostazionamenti del livello marino, rappresentati da solchi bioerosivi, piattaforme d’abrasione e dal limite superiore orizzontale dei fori di litodomi. spesso a queste forme erosionali si associano depositi marini, costituiti da sabbie e puddinghe che localmente contengono resti di molluschi, alghe rosse e coralli. queste evidenze sono preservate lungo le paleofalesie o all’interno di grotte costiere, in molti casi di origine carsica. depositi continentali sono a volte associati alle successioni marine; si tratta soprattutto di depositi eolici, colluvioni, paleosuoli e, all’interno delle grotte, di speleotemi e brecce graviclastiche. in molte località questi depositi contengono industrie paleolitiche che possono essere considerate come limite cronologico inferiore o superiore per le linee di riva ad esse associate. l’analisi dei rapporti geomorfologici, le posizioni stratigrafiche e la correlazione altimetrica tra i depositi continentali e marini hanno permesso di ricostruire la loro cronologia relativa e le fasi di morfogenesi costiera legate all’interazione tra le variazioni del livello marino e i movimenti di sollevamento. analisi mineralogiche sono state condotte sui paleosuoli allo scopo di ottenere delle ricostruzioni paleoambientali. inoltre, sono state eseguite datazioni th/u di alcuni speleotemi che poggiano su/ o sono coperti da depositi marini, al fine di ottenere dei vincoli cronologici per la ricostruzione degli eventi. tra 75 e 15 m s.l.m. sono stati riconosciuti almeno sei ordini di terrazzi marini medioplestocenici; questa gradinata di terrazzi si è preservata completamente solo lungo il settore costiero occidentale del monte bulgheria. tra 10 e 3.5 m s.l.m. sono presenti altri tre paleostazionamenti marini, il più recente dei quali è rappresentato da una puddinga fossilifera che passa verso l’alto a sabbie. l’età th/u dello speleotema (90 ka bp) su cui si rinvengono i suddetti depositi marini e quella dello speleotema che copre le sabbie (50 ka bp) permettono di ascrivere questa linea di riva al substage 5a della stratigrafia isotopica. tale attribuzione è confermata dall’età mousteriana delle brecce graviclastiche poggianti sul deposito marino. keywords: paleo-sea level stands, late quaternary, speleothem, paleosol, u-series dating, cilento promontory, southern italy. parole chiave: paleostazionamenti del livello marino, tardo quaternario, speleotema, paleosuolo, datazioni con la serie dell’uranio, cilento, italia meridionale. il quaternario italian journal of quaternary sciences 1166(1), 2003, 3-14 11 iinnttrroodduuccttiioonn the cilento promontory is a large structural high located between the gulf of salerno to the north and the policastro gulf to the south (fig.1). its southern coasts are carved in high resistant rocks such as limestones and cherty limestones (flintstones) of the mt. bulgheria mesozoic– caenozoic units. due to the pliocenequaternary tectonic history of the mt bulgheria massif, which was characterised by several phases of normal faulting mainly ew and ne sw trending (ascione et al., 1997), the coast of southern cilento is constituted by 4 c. esposito et al. same structure-controlled bays, filled in some cases with sandy and gravelly beaches (capo grosso, cala d’arconte, la calanca and lentiscelle beaches), which alternate with active vertical sea cliffs from some metres to hundreds of metres high. karstic caves, more or less reworked and enlarged by marine abrasion (esposito et al., 2001), are present all along the carbonate active and inactive sea cliffs. the slope developing over the sea cliff is characterised by a flight of marine terraces, from 400 to10 m above the present sea level, cut by subsequent and consequent stream valleys. according to the last researches carried out on the marine terraces of southern cilento (ascione & romano, 1999; russo, 1994), the eutyrrhenian shoreline (i.e. the one correlated with the oxygen isotope substage 5e) can be found at almost the same elevation along the coast of mt. bulgheria; i.e. it was recognised at cala bianca bay at 6 m a.s.l. by means of racemization on astralium shells (russo, 1994). these findings testifie a late quaternary tectonic stability for the area. moving southward of the mt. bulgheria coasts, a moderate upper pleistocene-holocene tectonic uplift was highlighted near sapri, where brancaccio et al. (1990) recognised, at 15 m a.s.l., fossiliferous marine conglomerates dated to the eutyrrhenian transgression. finally, evidence of post-eutyrrhenian subsidence was pointed out at capo palinuro, the carbonate promontory that bounds mt. bulgheria to the north, where a + 2 m high marine notch was correlated to the oiss 5e sea level highstand (antonioli et al., 1994). in this paper the results of a detailed survey carried out on the late quaternary shorelines along the coast of mt. bulgheria are presented. the collected data refer to all the erosional and depositional indicators of fossil shorelines which are preserved along the active and inactive sea cliffs as well as inside the coastal caves. as erosional indicators we considered the point of maximum concavity of bioerosive notches (sensu pirazzoli, 1996), the inner rim of wave-cut terraces and the upper limit of burrows (the latter only when straight, horizontal and laterally continuous for some metres). along the fossil shorelines, a detailed survey was also carried out on the continental deposits associated with the erosional and depositional marks of strandlines, such as alluvial and colluvial deposits, paleosols, tephra layers and speleothems. 22 ggeeoollooggiiccaall aanndd ggeeoommoorrpphhoollooggiiccaall sseettttiinngg ooff tthhee ssoouutthheerrnn cciilleennttoo starting from the sixties, several geological, structural and geomorphological studies have been carried out in order to reconstruct the mt. bulgheria long and short term geological history (scandone et al., 1964; ciampo, 1976; lippmann-provansal, 1987; borrelli et al., 1988; tozzi et al., 1996; ascione a., 1997; ascione et al., 1997; ascione & romano, 1999). the massif is a topographic high made up of a carbonate succession upper triassic to lower miocene in age which is unconformably covered by pliocenequaternary continental, transitional and marine deposits. the pliocene-quaternary geomorphological and tectonic evolution of mt. bulgheria is testified by fluvial and lacustrine terraces, wave-cut and wave-built marine terraces, structure controlled forms (such as fault scarps, subsequent fluvial valleys, etc.), as well as by the above quoted successions of different sedimentary environments. in particular, the early pleistocene depositional events were recorded by marine successions: the s. vito formation, santernian in age (ascione, 1997), the lentiscosa formation (sgrosso & ciampo, 1966; lippmann provensal, 1987; borrelli et al., 1988), the cala bianca frms emilian in age (sgrosso & ciampo, 1966; ciampo, 1976) and torre dell’isola frms, emilian in age (ascione, 1997). all these formations are unconformably lying on the caenozoic and mesozoic fig. 1 location of the studied area. ubicazione dell’area studiata. units. nowadays these successions outcrop between 400 and 0 m a.s.l. (fig.2). in same cases these formations are associated with depositional terraces displaced between 450 m and 300 m a.s.l. by subsequent phases of normal faulting. the wave cut terraces located between 450 and 300 m a.s.l. are correlated with the lower pleistocene depositional marine terraces. the flight of erosional and depositional marine terraces located between 150 and 12÷10 m a.s.l., which formed during middle pleistocene, testifies the effect of the final uplift that affected the mt. bulgheria and the last phase of relief growth. moreover, the fact that the terraces develop with continuity along the coastal belt indicate at the same time the cessation of block faulting. according with ascione & romano 1999 during upper pleistoceneholocene, due to the substantial tectonic stability of the area, the coastal morphogenesis mainly proceeds in response to climate oscillations and the consequent glacio-eustatic sea level fluctuations. 5late quaternary shorelines ... 33 ssttrraattiiggrraapphhiiccaall aanndd ggeeoommoorrpphhoollooggiiccaall ddaattaa a detailed geological and geomorphological survey of the coast between t. fenosa and cala degli infreschi, along the southern slope of mt. bulgheria, was carried out. the recognised erosional and depositional evidence of ancient paleo-sea levels were grouped into five main ranges of altitude: 12÷10, 8.5÷8; 7.5÷5, 4.5÷4, 3.5÷3 (fig.2). in the eastern sector of the studied area, in a little circular bay named cala degli infreschi, a well preserved stratigraphical record is present made by both marine and continental deposits. a particular attention was thus focused on this bay. eevviiddeennccee aatt 1122÷÷1100 m a.s.l.– this shoreline is mainly represented by wave-cut terraces (fig.3), continuously present along the coastal sector, cut in both the monte bulgheria mesozoic limestones and the torre fig. 2 geomorphological map of southern sector of mt.bulgheria (salerno-italy) and synthetic table of morphological indicators of paleo-sea levels between 12-10 m and 0 m a.s.l. carta geomorfologica del settore meridionale del mt. bulgheria (salerno, italia) e tabella riassuntiva degli indicatori morfologici di paleolinee di riva tra 12-10 m e 0 m s.l.m. 6 dell’isola conglomerates (emilian stage). the stratigraphical constraints for this order of terraces are well exposed at cala d’arconte and capo grosso bays where two different generations of paleosols, developed on colluvial deposits, cover the wave-cut terraces. the oldest one (2.5÷3 m thick) is reddish, contains manganese nodules and some stonel ines; several art i facts of acheulean age were reported by palma di cesnola (1982). the youngest paleosol (6 m thick), discordant on the other, is brownish-red and does not contain gravels; mousterian artifacts were found in it (palma di cesnola, 1982). a lens of grey, weathering pyroclastic sand is present at the top of the youngest paleosol. in the cilento area the mousterian lithic industries are dated between 130 and 40 ka b.p. (gambassini & ronchitelli, 1998). this means that the oldest colluvium, which only contains acheulean artifatcs, was settled before 130 ka b.p.; consequently the age of the 12÷10 m terrace, over which the paleosol is located, is pre-tyrrhenian. another evidence of this shoreline is represented by the inner edge of the wave-cut terrace located at 10 m a.s.l. and covered by marine grey sandstones along the cala d’arconte promontory, and by a bioerosive notch, clearly visible on the right side of grotta della serratura cave, in the cala lentiscelle bay. eevviiddeennccee aatt 88..55÷÷88 mm aa..ss..ll.– this shoreline is represented by a wave-cut terrace in the west side of calanca bay, by horizontal upper limits of lithophagous burrows, between monte di luna and cala bianca and in riparo infreschi cave, and by two bioerosive notches in cala bianca bay and in the infreschi cave. eevviiddeennccee bbeettwweeeenn 77..55 aanndd 55 mm aa..ss..ll..between torre fenosa and marina di camerota wave-cut terraces and bioerosive notches, located at 6÷5 m a.s.l., represent the evidence of an ancient shoreline. remains of grey marine sandstones are associated with some of these terraces. on the torre dell’isola promontory a bioerosive notch located at 7.5 m a.s.l. may be the evidence of another paleo-sea level, but no similar evidence was found along the coastal sector. in particular, on this promontory between 7.5 and 5 m a.s.l.. at least three relative paleo-sea levels can be recognised, respectively at + 7.5 , + 5 m. and + 7 m (fig.4). at 5 m a.s.l., in fact, a wave-cut terrace with polygenic well rounded beach conglomerates is present. the conglomerates are unconformably covered by a fossiliferous marine deposit (1.5 m thick), which laterally passes to a clinostratified grey sandstone (2 m thick). the latter is cut at 7 m a.s.l. by a sub--horizontal surface that looks like another wave-cut terrace. a reddish continental deposit covers this terrace and fills the bioerosive c. esposito et al. fig. 3 the10 m a.s.l. wave-cut terrace of cala d’arconte promontory. terrazzo d’abrasione dei 10 m s.l.m. sul promontorio di cala d’arconte. fig. 4 schematic profile of torre dell’isola sector. ca-mesozoic limestone; co1marine monogenic conglomerates and breccias of torre dell’isola succession; co2marine polygenic conglomerates; snmarine sands; cn-continental deposits with breccias and flowstone; n-bioerosive notch lithophaga burrows. profilo schematico del settore di torre dell’isola. cacalcari mesozoici; co1-puddinghe monogeniche e brecce della successione di torre dell’isola; co2puddinghe poligeniche; snsabbie marine; cndepositi continentali con brecce e concrezioni; nsolco bioerosivo; fori di litodomi. 7 notch at 7.5 m a.s.l., too. stratigraphic relations between erosional features and deposits suggest the following relative chronology of events: the + 7.5 m notch represents a first paleosea level stand, the + 5 m wave-cut terrace and the grey marine sandstones indicate a subsequent sea level stand and a relative trasgression, finally the sea level stand rises again, as the + 7 m wave-cut terrace testifies. after this marine phase, the deposition of continental deposit occurs. eevviiddeennccee aatt 44..55--44 mm aa..ss..ll..between torre zancale and cala degli infreschi, bioerosive notches and wavecut terraces are clearly visible at 4.5÷4 m a.s.l.. these erosional morphologies are rather continuous and sometimes remains of grey marine sandstones (similar to the sandstone cropping out on the + 5 m terrace located w of marina di camerota, see precedent paragraph) are visible on the terrace. in the cala bianca and cala degli infreschi bays a cladocora-bearing biocalcarenite is present on the 4.5 m wave-cut terrace. eevviiddeennccee aatt 33..55--33 mm aa..ss..ll.– evidence of this shoreline was mainly observed in the eastern coastal sector and along the western promontory of the calanca bay (fig.5) where a continuous (ca. 200 m) and well-marked wave-cut terrace with marine sandstones (max 2 m thick) is present. 33..11 tthhee ccaassee ooff ccaallaa ddeeggllii iinnffrreesscchhii.. in the sub-circular bay of cala degli infreschi a lot of different erosional indicators of paleo-sea level stands together with marine and continental deposits were collected; the stratigraphical record is well preserved in two little caves located in the western sector of the bay: the infreschi cave and the riparo infreschi cave (fig. 2). tthhee iinnffrreesscchhii ccaavvee this cave represents a remnant of an ancient karstic phreatic level (esposito et al., 2001) connected with the basal water table of mt. bulgheria, that nowadays flows into the sea through karstic channels located along the western rim of the bay. the oldest evidence of a paleo-sea level stand is represented by a well-marked bioerosive notch located at 8 m a.s.l. on the right side of the cave (fig 6, 7a); this notch is cut by a wide strip of lithophaga burrows, whose upper limit is horizontal and located at 8.5 m late quaternary shorelines ... fig. 5 the 3.5 m a.s.l. wave-cut terrace of calanca bay. la piattaforma d’abrasione di 3,5 m s.l.m. della baia della calanca. fig. 6 schematic profile of infreschi cave. ca-mesozoic limestone; co1-marine conglomerates; bcbiolimestonenite with cladocora; co2-marine conglomerates; snmarine sands; brgraviclastic breccias; ps-paleosol; pr-pyroclastic layer; n-bioerosive notch; lithophaga burrows. profilo schematico di grotta degli infreschi. cacalcari mesozoici; co1puddinghe; bcbiolimestonenite a cladocora; co2puddinghe; snsabbie marine; brbrecce graviclastiche; ps-paleosuolo; prpiroclastite; nsolco bioerosivo; fori di litodomi. 8 a.s.l.. at the entrance of the cave a wave-cut terrace is present at 4.5 m a.s.l. (fig.6, 7b) cut in the carbonate succession of mt. bulgheria as well as in a monogenic carbonate beach conglomerate. the external rim of this terrace is covered by a cladocora-bearing biocalcarenite which is also visible in remains on the wall of the cave up to 6 m a.s.l.. this biocalcarenite is covered by a polygenic beach conglomerate (ca.1 m thick) passing upward to plano-parallel stratified sands, clearly trasgressive and unconformable on the cladocora-bearing biocalcarenite; the top of these sands reaches the altitude of 6 m. along the scarp of the + 4.5 m wave-cut terrace a bioerosive notch, located at about 3.5 m a.s.l., is present and continuously well preserved also in the area surrounding the cave. at the back of the cave a continental succession covering the sands is preserved; it is made up of graviclastic carbonate breccias almost without matrix, passing upward to a brownish paleosol with manganese nodules (see p.5). two strongly altered yellowish pyroclastic levels are included in the paleosol. tthhee rriippaarroo iinnffrreesscchhii ccaavvee this site represents the remains of an ancient coastal cave, like that of infreschi, now destroyed by roof c. esposito et al. fig.7 infreschi bay. athe 8 m a.s.l. bioerosive notch; b-the 4 m a.s.l. wave-cut terrace. cala degli infreschi. asolco bioerosivo a quota 8 m s.l.m.; bpiattaforma d’abrasione dei 4 m s.l.m. fig. 8 schematic profile of riparo degli infreschi cave. ca-mesozoic limestone; co1-marine conglomerates; sp1speleothem; lithophaga burrows; brgraviclastic breccias; n-bioerosive notch; co2-marine conglomerates; sn-marine sands; brmmousterian graviclastic breccias; sp2speleothem; pspaleosol; pr-pyroclastic layer. profilo schematico del riparo degli infreschi. cacalcari mesozoici; co1puddinghe; sp1speleotema; fori di litodomi; brbrecce graviclastiche; nsolco bioerosivo; co2puddinghe; snsabbie marine; brmbreccia graviclastica di età musteriana; sp2speleotema; ps-paleosuolo; prpiroclastite. falls. also in this case a well preserved record of marine and continental deposits is present (fig.8, 9). mousterian lithic industries were found in the continental part of the succession (guide archeologiche, 1996). all deposits are preserved on the left side and in the central part of the paleo-cave together with erosional evidence of paleo-sea level stands. in particular, the highest evidence is represented by a wide strip of burrows whose horizontal upper limit rests at 8.5 m a.s.l.. at about 8 m a.s.l., a flowstone drapping the wall of the cave was found, which was cut by the burrows and then sampled for u-series dating (sspp11--rrii 77). at about 6 m a.s.l. carbonate marine conglomerates are covered by a speleothem; as the carbonate substratum, both of them are cut by burrows (fig.10). this speleothem was sampled for u-series dating. (sspp11--rrii 55). over the carbonate marine conglomerates and over the speleothem, marine sands are present, which aa bb 9late quaternary shorelines ... fig. 9 riparo degli infreschi cave. co1marine conglomerates; sp1speleothem; brgraviclastic breccias; co2-marine conglomerates; snmarine sands; sp2speleothem; pspaleosol; prpyroclastic layer; ri 7sample of sp1 at 8 m a.s.l.; ri 5sample of sp1 at 6 m a.s.l.; ri1sample of sp2. riparo degli infreschi. co1puddinghe; sp1speleotema; brbrecce graviclastiche; co2puddinghe; snsabbie marine; sp2speleotema; pspaleosuolo; prpiroclastite; ri 7campione di sp1 a 8 m s.l.m.; ri 5campione di sp1 a 6 m s.l.m.; ri 1campione di sp2. fig. 10 riparo degli infreschi cave. aspeleothem cut by lithophaga burrows; bspeleothems and marine conglomerates cut by litophaga burrows. riparo degli infreschi. aspeleotema tagliato da fori di litodomi; bspeleotemi e puddinghe tagliati dai fori di litodomi. aa bb fig. 11 infreschi cave paleosol. xrd patterns for fine clay (< 0.2 mm) fractions after different treatments in horizon b3. il = illite; k = kaolinite; sm = smectite; d is expressed in nm. palesuolo di grotta degli infreschi. diffrattogrammi ai raggi x delle argille fini (< 0.2 mm) con differenti trattamenti nell’orizzonte b3. il = illite; k = caolinite; sm = smectite; d è espressa in nm. reach 6 m a.s.l. and clearly cover the burrows. these marine sands also cover a bioerosive notch located at 3.5 m a.s.l., which cuts the flank of the cave. the sands pass downward to carbonate marine conglomerates with abundant matrix and gasteropod shells with spines. in the central part of the paleo-cave at 4 m a.s.l., this conglomerate clearly covers a flowstone which is cut by several burrows. this speleothem was also dated using u-series (sspp11--rrii 44) . a graviclastic breccia containing remains of mousterian age is present over the above mentioned conglomerate, testifying human frequenting of the cave at the end of upper pleistocene. over the breccia deposit a pyroclastic level , which passes upward to a brownish paleosol, is preserved in a corner of the paleo cave. this pyroclastic level is strongly weathered and for this reason its petrochemical analysis didn’t give any significant result. further flowstones, laying on the sands and on the breccia deposits and never cut by burrows lithophaga, were sampled (sspp22--rrii 11) in order to give upper chronological constraints to the reconstruction. 44 uu--sseerriieess ddaattaa four speleothems interbedded with marine deposits were sampled in riparo infreschi cave and analysed by u-series disequilibria. samples were accurately fieldselected in order to exclude all materials with macroscopic signs of weathering and further examined under a binocular microscope to refine the selection. fragments with no trace of secondary alteration were analysed according to standard procedures (bischoff et al., 1988). three to six gram samples were spiked with a 228th + 232u tracer (in secular equilibrium) and activity ratios were counted in an eg&g ortec 920-8 alpha spectrometer system. the ages and the initial 234u/238u activity ratios were calculated by means of isoplot, a plotting and regression program designed by ludwig (1994) for radiogenic-isotope data. the uranium contents, the activity ratios and the calculated 230th ages are listed in tab.1; all errors are reported as 1 sigma. coral samples from infreschi cave in cala degli infreschi were not analysed because of recrystallization problems, testified by high proportion of calcite. also red algae samples contained in the calcarenite from the same cave were not suitable for the dating because of the high content of secondary carbonate cement, making the obtained age too young and not consistent with the overall evolution of the area. 55 ppeeddoollooggiiccaall ddaattaa the soil profile of the infreschi cave is characterised by morphological description and bulk sampling for mineralogical analyses (xrd of the fine clay and the sand fractions). the main morphological features are reported in tab. 2. on the basis of the reddish to brownish colours determined with the munsell soil color charts (munsell, 1994), also the redness rate (torrent et al., 1980) was evaluated and applied to estimate hematite content according to ferrari & magaldi (1983): the former values range from 3 to about 12 allowing to predict up to 1.4 % hm (data not shown), approximately accordant with the method proposed by torrent et al. (1983). the weak to null effervescence reaction given by the hcl test (10% solution) allows to estimate no more than 2 % of carbonate in the soil. x-ray diffractometry of the sand fraction indicates the dominance of quartz among the mineral grains, with the presence of feldspars and micas in suborder (data not shown). also calcite was recognised, presumably related to the secondary calcium carbonate precipitations observed. xrd analysis of fine clays shows a mineralogy mainly formed by kaolinite, illite and smectite (fig 11). halloysitic components, possibly deriving from the weathering of the pyroclastic material, cannot be excluded, although no specific treatment was performed to discriminate them from kaolinite. the examined paleosol can be regarded as terrae rossae-like (rhodoxeralfs, sensu usda, 1998), largely widespread in southern italy and other lowand mid-latitudinal areas, and widely studied by several authors (e.g. colombo & terribile, 1994; bellanca et al., 1996; bronger & bruhn-lobin, 1997; yaalon et al., 1997; yassoglou et al., 1997; durn et al., 1999). ccoonncclluussiioonn along the southern sector of the mt. bulgheria, between 12÷10 e 0 m a.s.l. several paleo-sea level evidence was identified and gathered in five range of altitude. the oldest one (12÷10 m a.s.l.) is pre-tyrrhenian in age. the lower evidence develop not continuously along 10 c. esposito et al. sample ppb u (234u/238u) (230th/234u) (230th/232th) (234u/238u) init. age (ka) ri 1 827 ± 17 1.032 ± 0.023 0.373 ± 0.011 40 ± 2 1.037 ± 0.027 50.6 ± 1.9 ri 4 608 ± 42 1.049 ± 0.029 0.565 ± 0.022 38 ± 2 1.063 ± 0.037 89.8 ± 5.4 ri 5 102 ± 4 1.364 ± 0.071 0.588 ± 0.035 infinite 1.472 ± 0.092 91.7 ± 8.2 ri 7 141 ± 5 1.086 ± 0.053 0.650 ± 0.038 infinite 1.118 ± 0.072 111.9 ± 11.0 tab.1u-series data of speleothems from riparo infreschi, (italy). quoted ratios are activity ratios and errors are expressed as 1 sigma. (234u/238u)init. represents the initial uranium activity ratio. datazioni u-series degli speleotemi del riparo degli infreschi, (italia). i rapporti riportati sono rapporti di attività e gli errori sono espressi come 1 sigma. (234u/238u)init. rappresenta il rapporto di attività iniziale dell’uranio. the coastal belt, so it’s difficult to correlate them. moreover, continental and marine deposits associated with these erosional features not provide chronological constraints, with the exception of the deposits surveyed in the infreschi bay. the stratigraphical data collected in the infreschi and riparo infreschi caves were tentatively correlated (tab. 3). the th/u ages of the speleothems sp2-ri1, sp1ri4 and sp1ri5 represent good chronological constraints for the marine sands and conglomerates of the riparo infreschi cave (sn and co2 in figg. 7 and 9) suggesting their attribution to the oiss 5a (>50 ka bp and <89 ka bp). we correlated them to the marine conglomerates and sands that partly fill the nearby infreschi cave and which have the same stratigraphical (are covered by similar graviclastic breccia and paleosol) and altitudinal (in both cases the top of the sands is located at 6 m a.s.l..) position. therefore, these deposits testify a distinct marine ingression in both caves, occurring between two episodes of continental deposition, the last of which is represented by graviclastic breccias and paleosols. in particular, the infreschi cave paleosol shows an intense degree of weathering, probably partly inherited. in fact, it consists of reworked soil sediments with much allochthonous windblown material, previously weathered under interglacial climatic conditions, clearly warmer 11late quaternary shorelines ... tab. 2description of the infreschi cave’s paleosol. descrizione del paleosuolo di grotta degli infreschi. and wetter than today’s. soil reworking should have occurred after the deposition of the marine sands, followed by pedogenesis in the cave, which homogenised this parent material and led to the horizon differentiation and soil aggregation observed in the profile. soil features related to in situ pedogenesis appear compatible with the succession of the last glacial and holocene environments, alternating drier and moister phases at different time scales (103 102 years to yearly and seasonal cycles) and with very different temperature ranges in a “protected” site such as the infreschi cave. the th/u age of the speleothem sp1-ri 7 gives a lower chronological constraint (younger than 111 ka bp) for the evidence of paleo-sea level stands represented by the upper limit of lithophaga. because this limit is located at the same altitude in the infreschi caves we ascribed both evidence to oiss 5c. because of their relative chronological position, other evidence of ancient shorelines collected in the bay can also be ascribed to oiss 5c or to oiss 5a, but it is not clear if they represent complex oscillations within a single stage (substages) or pauses of the same transgressive event. other stages, such as the oiss 5e, have shown to be composed by complex, secondary fluctuations of the paleo-sea level (hearty & kindler, 1995; neumann & hearty, 1996; zazo, 1999). other important considerations have to be made about the altitude of the collected evidence. the top of the marine sands reach in fact 6 m a.s.l. and the upper limit of the burrows is located at 8.5 m a.s.l.; both these altitudes are too high, if compared to the paleo-eustatic level quoted for the oiss 5a and 5c. in fact, even if no agreement has been achieved in the scientific literature about the relative altitude of the sea during these stands, the suggested values are always around or below the present day elevation. in particular, ku eett aall..(1990) and richards et al.(1994) affirmed that both during the oiss 5c and 5a the sea level was much lower than the present one. in contrast, other authors, stated that during the oiss 5a the sea level was close to the present one both in extramediterranean (hearty & kindler, 1995; ludwig et al., 1996) and mediterranean areas (hearty, 1986). for this reason we hypothesise a tectonic uplift of this sector of the coast after the isotopic sub-stage 5a, although we have no elements for estimating the rates and values of this movement. these considerations made us prudent in correlating the other evidence of paleo-sea level stands collected along the coast of mt. bulgheria. however, the evidence collected at 4.5÷4 m a.s.l., which, in most cases, is associated with depositional sand bodies, could probably be correlated to the marine sands and conglomerates of the cala degli infreschi bay and ascribed to oiss 5a. the reconstruction could be complicated by the possibility of hydroisostatic rebounds for each highstand, as proposed in literature for the last highstand (ois 1) (fleming et al., 1998; lambeck & bard, 2000). this model could probably explain the complex fluctuations we found in the infreschi bay but in other sites along the campanian coast the evidence of oiss 5c and 5a are located at different altitudes: 4 m a.s.l. and 1.5 m a.s.l. respectively along the punta licosa promontory (iannace et al., 2001); around 13 m a.s.l. in the sele river plain (brancaccio et al., 1986) and around 2 m a.s.l. in the sorrento peninsula. (riccio et al., 2001), thus testifying the existence of recent tectonic activity along the campanian coast. 12 c. esposito et al. infreschi cave infreschi riparo isotopic stages graviclastic breccia covered by graviclastic breccia containing paleosol with pyroclastic layer remains of mousterian age (130 40 ka bp) covered by pyroclastic layer and flowstones (sp2-ri 1, 50 ka bp) marine conglomerates and marine conglomerates and sands ois 5a sands (sands top at 6 m a.s.l.) that are covered by sp2-ri 1 (>50 that covered a bioconstruction ka bp) and lay on a flowstone with with cladocora coespitosa. lithophaga burrows (sp1-ri 4, ri 5 89 e 91 ka bp, ois 5b). the sands reach an altitude of 6m a.s.l. and they also cover a notch at 3,5 m a.s.l. notch at 3,5 m a.s.l. notch at + 3,5 m bioconstruction with lithophaga burrows between cladocora coespitosa 4/6 m < 89 e 91 ka bp flowstone (sp1-ri 4,ri 5) 89 e 91 ka bp ois 5b wave-cut terrace at + 4,5m. marine conglomerates covered a.s.l.. by sp1-ri 4,ri 5and cut by lithophaga burrows notch at + 8 m upper limit of lithophaga upper limit of lithophaga burrows at + 8,5 m that cut the burrows at 8,5 m a.s.l. that cut ois 5c notch sp1-ri 7 < 111 ka bp flowstone sp1-ri 7 ois 5d 111 ka bp tab. 3 stratigraphic correlation between the infreschi cave and riparo degli infreschi cave correlazione stratigrafica tra la grotta degli infreschi ed il riparo degli infreschi. rreeffeerreenncceess antonioli f., cinque a., ferranti l. & romano p., 1994 emerged and submerged quaternary marine terraces of palinuro cape (southern italy). mem. descr. carta geol. d’it., lliiii, 237-260. ascione a. & romano p., 1999 -vertical movements on the eastern margin of the tyrrhenian extensional basin . new data from mt. bulgheria (southern apennines, italy). tectonophysics, 331155, 337-356. ascione a., 1997 studio morfostrutturale sulla genesi del rilievo in appennino meridionale. phd thesis, università di napoli “federico ii”. ascione a., caiazzo c., hippolyte j.c. & romano p., 1997 pliocene-quaternary extensional tectonics and morphogenesis at the eastern margin of the southern tyrrhenian basin (mt. bulgheria, campania, italy). il quaternario, 1100(2), 571-578. bellanca a., hauser s., neri r., palumbo b., 1996 mineralogy and geochemistry of terra rossa soils, western sicily: insights into heavy metal fractionation and mobility. the science of the total environment, 119933, 57-67. bischoff, j.l., rosenbauer, r.j., tavoso, a. & lumley, h., 1988 a test of uranium-series dating of fossil tooth enamel: results from tautavel cave, france. applied geochemistry, 33, 145-151. borrelli a., ciampo g., de falco m., guida d. & guida m., 1988 la morfogenesi del monte bulgheria (campania) durante il pleistocene inferiore e medio. mem. soc. geol. it., 4411, 667-672. brancaccio l., cinque a., belluomini g., branca m. & delitala l., 1986 isoleucine epimerization dating and tectonic significance of upper pleistocene sea-level features of the sele plain (southern italy). z. geomorph. n. f., suppl.-bd. 6622, 159-166. brancaccio l., cinque a., russo f., belluomini g., branca m. & delitala l., 1990 segnalazione e datazione di depositi marini tirreniani sulla costa campana. boll. soc. geol. it., 110099, 259-265. bronger a. & bruhn-lobin n., 1997 paleopedology of terrae rossae-rhodoxeralfs from quaternary calcarenites in nw morocco. catena, 2288(3-4), 279295 ciampo g., 1976 ostracodi pleistocenici di cala bianca (marina di camerota, salerno). boll. soc. paleont. it., 1155, 3-23. colombo c. & terribile f., 1994 weathering relationships between glauconite, aluminous illite and iron oxides in terra rossa of southern italy. proc. 15th world congr. soil science, acapulco, mexico, 88a, 49-66. durn g., ottner f., slovenec d., 1999 mineralogical and geochemical indicators of the polygenetic nature of terra rossa in istria, croatia. geoderma, 9911, 125-150. esposito c., filocamo f., marciano r., romano p., santangelo n. & santo a., 2001 genesi, evoluzione e paleogeografia delle grotte costiere di marina di camerota (parco nazionale del cilento e vallo di diano, italia meridionale). in stampa su thalassia salentina. ferrari g.a. & magaldi d., 1983 significato ed applicazioni della paleopedologia nella stratigrafia del quaternario. boll. mus. civ. st. nat. verona, xx,, 315-340. fleming k., johnston p., zwartz d., yokoyama y., lambeck k. & chappell j., 1998 redifining the eustatic sea-level curve since the last glacial maximum using far-end intermediatefield sites. earth planet. sci. lett., 116633,, 327-342. gambassini p. & ronchitelli a., 1998 linee di sviluppo dei complessi del paleolitico inferiore-medio nel cilento. rivista di scienze preistoriche, 4499, 357376. guide archeologiche, 1996 il paleolitico dell’italia centro-meridionale. xiii congresso uissp, forlì, 11, 43-49. hearty p.j. & kindler p., 1995 -sea-level highstand chronology from stable carbonate terraces (bermuda and the bahamas). journal of coastal research, 1111(3), 675-689. hearty p.j., 1986 an inventory of last interglacial (sensu lato) age deposits from the mediterranean basin: a study of isoleucine epimerization and useries dating. z. geomorph. n. f. suppl.-bd. 6622, 51-69. iannace a., romano p., santangelo n., santo a. & tuccimei p., 2001 the ois 5c along licosa cape promontory (campania region, southern italy): morphostratigraphy and u/th dating. z. geomorph. n. f., 4455(3), 307-319. ku t.l., ivanovich m. & luo s., 1990 u-series dating of last interglacial high sea stands: barbados revisited. quat. res., 3333, 129-147. lambeck k. & bard e., 2000 sea-level change along the french mediterranean coast for the past 30.000 years. earth planet. sci. lett., 117755, 203222. lippmann-provansal m., 1987 l’apennin campanien mèridional (italie). etude geomorphologique. these de doctorat. univ. d’aixmarseille, aix en provence. ludwig k.r., muhs d.r., simmons k.r., halley r.b. & shinn e.a., 1996sea-level records at ~80 ka from tectonically stable platforms: florida and bermuda. geology, 2244(3), 211-214. ludwig k.r., 1994 isoplot. a plotting and regression program for radiogenic-isotope data. version 2.75. u.s. geological survey, open-file report, 91-445. munsell, 1994 -munsell soil color charts. revised edit., munsell color company inc., baltimore (md.). neumann a.c. & hearty p.j., 1996 rapid sea-level changes at the close of the last interglacial (substage 5e) recorded in bahamian island geology. geology, 2244(9), 775-778. palma di cesnola a., 1982 il paleolitico inferiore in campania. atti xxiii riun. scient. ist. it. preist. e prot., firenze, 207-224. pirazzoli p.a., 1996 sea-level changes: the last 20 000 years. john wiley & sons, 210 pp. riccio a., riggio f. & romano p., 2001 sea level fluctuations during oxygen isotope stage 5: new data from fossil shorelines in the sorrento peninsula (southern italy). z. geomorph. n. f., 4455 (1), 121137. richards d.a., smart p.l. & edwards r.l:, 1994 13late quaternary shorelines ... maximum sea levels for the last glacial period from u-series ages of submerged speleothems. nature, 336677, 357-360 russo f., 1994 segnalazione di un livello fossilifero riferibile al tirreniano a cala bianca (marina di camerota). mem. descr. carta geol. d’it., 395398. scandone p., sgrosso i. & bruno f., 1964 appunti di geologia sul monte bulgheria (salerno). boll. soc. natur. in napoli, 7722, 19-27. sgrosso i. & ciampo g., 1966 sulla presenza dei terreni calabriani nei dintorni di camerota (salerno). boll. soc. natur. in napoli, 7755, 561-587. torrent j., schwertmann u., fechter h., alfarez f., 1983 quantitative relationships between soil color and hematite content. soil science, 113366(6), 354-358. torrent j., schwertmann u., schulze d.j., 1980 iron oxide mineralogy of some soils of two river terrace sequences in spain. geoderma, 2233, 191-208, amsterdam. tozzi m., meniconi a. & sciamanna s., 1996 studio strutturale del monte bulgheria (cilento meridionale) e sue implicazioni per la tettogenesi dell’appennino campano. boll. soc. geol. it., 111155, 249-278. usda, 1998 keys to soil taxonomy. 8th edition, soil survey staff, natural resources conservation service, washington d.c., 325 pp. yaalon d.h., 1997 soils in mediterranean region: what makes them different?. catena, 2288, 157-169. yassoglou n., kosmas c., moustakas n., 1997 the red soils, their origin, properties, use and management in greece. catena, 2288, 261-278. zazo c., 1999 interglacial sea levels. quaternary international, 5555, 101-113. 14 c. esposito et al. ms. ricevuto il 16 ottobre 2002 testo definitivo ricevuto l’11 febbraio 2003 ms. received: october 16, 2002 final text received: february 11, 2003 pag147_160 cencetti freduzzi.pdf analisi attraverso metodologia gis delle variazioni dei caratteri morfologico-sedimentari nella bassa valle del f. sinni (basilicata) corrado cencetti (*) & andrea fredduzzi (*) (*) dipartimento di ingegneria civile e ambientale università degli studi di perugia, via g. duranti, 93 06125 perugia, tel. +39 075 5853760, fax +39 075 5853756, e-mail corcen@unipg.it fredduzzi@unipg.it riassunto: cencetti c. & fredduzzi a. analisi attraverso metodologia gis delle variazioni dei caratteri morfologico-sedimentari nella bassa valle del f. sinni (basilicata). (it issn 0394-3356, 2008). la nota descrive i risultati di uno studio, eseguito tramite strumenti gis applicati ad un'analisi storico-cartografica, sulla dinamica fluviale del f. sinni (basilicata, versante ionico). lo scopo è di definire le condizioni attuali dell'alveo e di caratterizzare il suo trend evolutivo, elementi considerati entrambi necessari ai fini di una corretta “gestione” del sistema fluviale (in termini di risorsa ambientale e territoriale) che tenga conto delle modificazioni prodotte dall'attività antropica e delle loro conseguenze sul sistema stesso. lo studio si è così concentrato sull'analisi degli effetti prodotti da alcune opere idrauliche, quali in particolare la più grande diga in terra d'europa (monte cotugno) e altre minori che hanno profondamente condizionato la dinamica fluviale del fiume sinni. abstract: cencetti c. & fredduzzi a. analysis by gis of the variations of the morphological-sedimentary characteristics in the lowland of sinni river (basilicata). (it issn 0394-3356, 2008). the paper describes the results of a gis implemented study of fluvial dynamics about the morphological, sedimentary and human characteristics of the river sinni (basilicata, southern italy). the aims are to characterize the present riverbed conditions and to define the evolutionary trend of the alluvial plain riverbed system to assume criteria for a correct management of the fluvial system itself. the study was mainly focused on the determination of the impacts of some hydraulic works, first of all the mt. cotugno dam, which is the biggest earth dam in europe. the river sinni watershed measures 1427 km2 in area; the studied reach extends 36 km, from the mt. cotugno dam to the river mouth in the ionian sea. the study of morphological, sedimentary and human characteristics was primarily carried out by photointerpretation and by a field survey. moreover, the analysis of all the acquired historical documents (maps and aerial photographs) enabled us to measure the morphological planimetric variations of the riverbed occurred in the last 50 years. the mentioned activities were made by the implementation of a geographic database, which is an useful tool to visualize, to manage and to analyse all the collected data. the results show that the width of the active riverbed was progressively reduced (from 425 m in the 1954 to 110 m in the 2003); so the braiding index (from 3,1 m in the 1954 to 1,7 m in the 2003), while the extension of the vegetated sedimentary bodies increased (from 4,3 % in the 1954 to 37 % in the 2003) to the detriment of the ones devoid of vegetation. a qualitative analysis made on historical documents, anterior to the aerial photographs of the 1954, suggests that the changes started after the 1954. moreover we observed that such changes, pointed out by the historical analysis, didn't occur in the same way along the whole studied reach. in the first part, from the confluence with the major tributary (river sarmento) to the check dam of s. laura, the narrowing is substantially due to the reduction of the hydraulic discharge which caused a gradual shift from the sedimentary bodies, but there isn't evidence of vertical erosion or downcutting (which are indicators of the riverbed disequilibrium). this is happening because the sedimentary input of the river sarmento combined with the flow modulation produced by the mt. cotugno dam (which anyway causes the narrowing), are able to compensate the interruption of the sedimentary continuum due to the dam itself. downstream s. laura's check dam, until the river mouth in the ionian sea, the narrowing is connected with diffused processes of vertical erosion which induces a strong incision of the riverbed. in this reach we observed a morphological variation of the fluvial pattern: the riverbed passed from a multichannel braided type (comparable to the morphology of the upstream reach) to a single channel type with alternate bars (wandering). the causes of the present situation, in addition to the mentioned hydraulic works, are the quarrying activity and works of flow channelization (levees and bank erosion protections). parole chiave: fiume sinni, dinamica fluviale, trasporto solido, caratteri morfologico-sedimentari, analisi storica. key words: river sinni, fluvial dynamics, bedload transport, morphological-sedimentary characteristics, historical analysis. il quaternario italian journal of quaternary sciences 21(1b), 2008 147-160 1. introduzione le pianure alluvionali sono diventate in tempi storici aree d'intenso sviluppo urbanistico ed industriale. è per questo che non è più possibile prescindere da una corretta gestione del sistema fluviale che tenga conto di tutte le conseguenze degli interventi realizzati, comprese quelle che, in genere, sono scarsamente considerate e che riguardano la dinamica sedimentaria degli alvei. la corretta gestione del sistema alveo-pianura alluvionale costituisce, tuttavia, un problema ancora non completamente risolto, per una serie di motivi, tra i quali la carenza di conoscenza dei processi che agiscono nel sistema stesso, soprattutto per quanto riguarda il fenomeno del trasporto solido. le caratteristiche idraulico-geometriche di un sistema fluviale in ogni punto (variabili dipendenti) sono frutto di una serie di variabili di controllo (o variabili indipendenti) connesse con il clima, le caratteristiche geologiche del territorio, l'uso del suolo e i caratteri fisiografici del bacino imbrifero; tutti questi elementi insieme determinano il regime idrologico e sedimentologico del corso d'acqua. in aggiunta a questo tipo di forme di controllo 148 c. cencetti & a. fredduzzi naturali sul sistema, è necessario considerare gli effetti dovuti all'attività antropica, che interferisce con il sistema fluviale sia agendo direttamente sulle sue caratteristiche morfologico-sedimentarie (si considerino ad esempio gli interventi in alveo, la costruzione di opere idrauliche o l'attività estrattiva di inerti dall'alveo) sia indirettamente, modificando le variabili di controllo (per esempio l'uso del suolo). i corsi d'acqua costituiscono così dei sistemi molto complessi e dinamici, i cui caratteri variano nel tempo e nello spazio, in conseguenza dei cambiamenti delle suddette “variabili di controllo”. quando una modifica delle variabili indipendenti è tale da costituire una perturbazione della condizione di equilibrio, il sistema si sposta inevitabilmente verso una nuova condizione di equilibrio, che non rappresenta altro che l'adattamento del sistema all'ambiente circostante. per quanto detto, qualunque analisi dello stato di un alveo, effettuata assumendo che il fiume rimarrà nella sua condizione attuale, non avrà senso se il corso d'acqua non si trova in condizioni di equilibrio con l'ambiente circostante (bovee, 2004). in quest'ottica l'approccio geomorfologico-sedimentario allo studio dei corsi d'acqua parte dall'analisi delle forme e dei processi osservabili su un fiume, per ricostruire le trasformazioni che lo stesso ha subito nel tempo, individuarne le cause (alle diverse scale di analisi) e definire le sue tendenze evolutive; ciò al fine di intervenire sulla dinamica dell'alveo, ove necessario, senza stravolgerne le caratteristiche morfologico-sedimentarie e soprattutto senza innescare processi indesiderati. in pratica, lo scopo ultimo è quello di determinare l'equilibrio naturale del sistema, valutare i condizionamenti apportati dall'uomo e individuare le misure atte a mantenere o raggiungere un equilibrio dinamico opportuno, duraturo, fruibile e sostenibile. in questo contesto l'analisi delle variazioni morfologico-planimetriche di un corso d'acqua (analisi storica) rappresenta uno strumento molto efficace che, ampliando notevolmente la prospettiva temporale, consente di comprendere la naturale tendenza evolutiva del sistema fluviale quale si presentava, di norma, prima che i condizionamenti antropici modificassero le condizioni di naturalità e di equilibrio del sistema. nel caso specifico lo studio si è concentrato sull'analisi degli effetti prodotti nel sistema fluviale del f. sinni, in basilicata, da alcune opere, in particolare dalla più grande diga in terra d'europa (monte cotugno) e da altre minori, che hanno profondamente condizionato i processi di dinamica fluviale. il bacino idrografico del f. sinni si estende complessivamente per 1427 km2 (dei quali 1366 ricadenti in basilicata e 61 in calabria). il tratto studiato è compreso tra la diga di m. cotugno e la foce nel mar ionio ed è lungo complessivamente 36 km. nell'alveo si rileva, oltre al suddetto sbarramento, ultimato nel 1983, un'altra opera idraulica di notevole importanza, la traversa di s. laura, realizzata nel 1955 e situata a circa 11 km a monte della foce (fig. 1). 2. analisi storica le fonti storiche sono molto diversificate e non includono soltanto documenti cartografici o rilievi topografici (gu r n e l l et al., 2003). tuttavia i documenti relativi a rilievi topografici sono senza dubbio le fonti più importanti e tra questi sicuramente utilissimi sono i rilievi di sezioni trasversali e profili longitudinali. ai dati topografici “classici” si sono aggiunte recentemente le foto aeree e, da ultime, le immagini satellitari. per quanto riguarda la disponibilità, ma anche la precisione dei documenti relativi a rilievi topografici storici, l'inizio del diciannovesimo secolo costituisce un periodo importantissimo. è a partire da quella data, infatti, che si è verificata una vera e propria rivoluzione scientifica e tecnologica, frutto della forte espansione economica ed industriale dell'europa in quel periodo, che ha riguardato anche la produzione degli strumenti di rilevamento topografico. l'analisi dei documenti cartografici storici è fondamentale perché costituisce l'unico mezzo per determinare i cambiamenti avvenuti a medio e a lungo termine, in un intervallo di tempo che va dalle decine alle centinaia di anni, e consente numerose osservazioni qualitative e quantitative (cencetti, 2002). le osservazioni sono sintetizzate da una serie di parametri morfologici specifici, le cui variazioni nel tempo possono essere messe in evidenza tramite tre modalità: separatamente, in sovrapposizione o in sequenza. la sovrapposizione è generalmente usata per gli alvei monocanale (rettilinei, sinuosi o meandriformi), mentre la sequenza risulta più efficace per gli alvei intrecciati (surian, 2002). la tabella 1 riporta alcune delle informazioni che possono essere ricavate dalla cartografia storica. fig. 1 rappresentazione schematica del bacino e del reticolo idrografico del f. sinni. in bianco è evidenziata la porzione del tracciato oggetto del presente lavoro ed i tre tratti omogenei individuati. sketch of the watershed and of the hydrographical net of sinni river. the white line shows the three studied homogenous reaches. un corretto utilizzo dei documenti cartografici storici deve poi tenere conto dei limiti di affidabilità e di applicazione che li contraddistinguono; in particolare è necessario definire la precisione (accuratezza) dei documenti cartografici sotto diversi aspetti (gurnell et al., 2003). nel presente lavoro l'analisi storica delle variazioni morfologico-planimetriche dell'alveo è stata condotta in ambiente gis, utilizzando una procedura, basata sulla georeferenziazione, digitalizzazione e misura dei parametri di interesse, simile a quella utilizzata da numerosi autori (br a v a r d et al., 1997; leys & we r r i t t y, 1999; winterbottom, 2000; cencetti, 2002; surian, 2002). in particolare, la procedura prevede una prima fase di acquisizione e georeferenziazione dei documenti cartografici reperiti, utile per uniformare il sistema di riferimento e per determinare il grado di accuratezza dei documenti storici. successivamente è necessario procedere alla digitalizzazione di alcuni elementi morfologico-planimetrici comuni a tutti i documenti, la cui misura consente di effettuare confronti e di quantificare le modificazioni planimetriche subite dal tracciato del corso d'acqua nell'intervallo di tempo considerato. 2.1 acquisizione e georeferenziazione dei documenti cartografici la prima parte del lavoro è consistita in una ricerca bibliografica volta all'individuazione di tutti i documenti cartografici storici (mappe e foto aeree) disponibili per il tratto del corso d'acqua oggetto di studio. i documenti cartografici utilizzati sono stati i seguenti: 1. ortofotocarte digitali dell'autorità di bacino della basilicata (2003 risoluzione 40 cm, sistema di riferimento gauss boaga roma40); 2. carta tecnica regionale della regione basilicata, in scala 1:10.000 (1986 sistema di riferimento gauss boaga roma40); 3. fotogrammi aerei del volo g.a.i. (1954); 4. carte igm in scala 1:100.000 (1875-1900, sistema di riferimento non individuato fig. 2); 149analisi attraverso metodologia gis ... 5. carte itm (istituto topografico militare) in scala 1:30.000 (1870 circa, sistema di riferimento non individuato); 6. carte idrografiche in scala 1:100.000 (1890 circa, sistema di riferimento non individuato). i documenti cartacei sono stati scansionati in modo da ottenere una risoluzione al suolo pari a circa un metro. il dato ottenuto è stato poi georeferito utilizzando una procedura definibile “image to raster map” (neteler & mitasova, 2002) che consiste nelle seguenti fasi operative: individuazione a schermo di punti di controllo (gcps) comuni ai documenti storici (foto aeree o carte storiche) e ai documenti di supporto (ortofotocarte digitali del 2003); rettificazione delle immagini tramite algoritmi di trasformazione basati su polinomi di 1° ordine, al fine di evitare distorsioni; valutazione della precisione dell'operazione tramite la misura dell'errore relativo al posizionamento dei gcps (rms error). la procedura di georeferenziazione è stata eseguita in ambiente gnu-linux, utilizzando il software grass gis che dispone di alcuni moduli atti allo scopo ed estremamente efficaci (i.points, i.group, i.target, i.rectify). in particolare, il modulo di rettificazione i.rect i f y presenta l'enorme vantaggio di lavorare in b a c kground, a bassa priorità, e di avvertire l'utente con una e-mail di sistema una volta che il processo è terminato. ciò consente di continuare a lavorare sul progetto senza problemi di sovraccarico della memoria fisica e virtuale. anche le foto aeree sono state importate nel database tramite una semplice operazione di rettificazione, sebbene sarebbe stata più rigorosa una procedura di ortoproiezione. tuttavia, l'elevato numero di fotografie aeree da importare ha richiesto l'utilizzo di un metodo semplice e sufficientemente veloce allo stesso tempo. in questo caso, l'operazione di rettificazione può essere considerata accettabile, in quanto l'area di studio (una pianura alluvionale) è pianeggiante e ciò minimizza gli errori di distorsione dovuti alle differenze di tab. 1 informazioni desumibili dalla cartografia storica (da surian, 2002). information inferable from historical maps (from surian, 2002). quota. quanto detto è ampiamente dimostrato dai valori ottenuti dell'rms (root mean square) error l'esame degli errori di posizionamento dei punti di controllo (g c p s) ha consentito, quindi, di definire l'accuratezza spaziale dei documenti cartografici (rms error); gli errori medi ottenuti sono pari a 2,6 m per le c.t.r., 5,1 m per le foto aeree (volo g.a.i.), 6,9 m per le carte i.g.m. e 25,94 m per le carte i.t.m. i valori ottenuti possono essere considerati assolutamente compatibili con la precisione richiesta dalle finalità dello studio. 2.2 vettorializzazione e misura dei parametri morfologici seguendo l'approccio morfologico-sedimentario, il metodo di lavoro prevede innanzi tutto la definizione delle condizioni attuali del sistema. tramite l'analisi delle ortofotocarte del 2003 ed i rilevamenti speditivi sul terreno, gli elementi morfologici, sedimentari ed antropici utili a caratterizzare lo stato attuale dell'alveo e della pianura alluvionale del f. sinni sono stati cartografati ed importati in formato vettoriale all'interno di un database geografico. tra tutti gli elementi rilevati, quelli più importanti dal punto vista geomorfologico sono: i limiti dell'alveo attivo, definito come la porzione dell'alveo non intensamente vegetata e caratterizzata dalla presenza di sedimenti ghiaiosi o sabbiosi (wi nt e r b o t t o m, 2000); questo comprende il canale ed i corpi sedimentari non vegetati; l'asse dell'alveo, come sistema di riferimento intrinseco al sistema e qui definito, tra le varie opzioni possibili (ta c c o n i, 1990), come il luogo dei punti equidistanti dalle sponde; i corpi sedimentari, la cui frequenza ed estensione è correlata alla quantità di materiale solido trasportato dal corso d'acqua. per valutare il loro livello di mobilità, è utile rilevarne lo stato superficiale (fig. 3). il database così realizzato è uno strumento molto utile in un'ottica di “gestione” del sistema fluviale. è possibile, infatti, associare agli elementi vettoriali tutte le informazioni necessarie, sia sotto forma di attributi (es. tipo di corpi sedimentari, loro stato vegetativo e stato di attività) sia tramite collegamenti ad altri documenti (foto, schede monografiche, fogli di calcolo, etc.). inoltre, si possono eseguire operazioni topologiche, effettuare confronti tra i tracciati nei diversi stadi temporali, eseguire queries di vario tipo e altro. il database costituisce senza dubbio un'ottima base di partenza per la programmazione sia delle attività di monitoraggio dei processi fluviali, sia di eventuali studi successivi. per effettuare i confronti tra i tipi di tracciato fluviale nei diversi stadi temporali è necessario misurare alcuni parametri comuni a tutti i documenti cartografici 150 fig. 2 carta topografica igm (1875-1900). particolare della confluenza con il f. sarmento. topographic map by igm (italian geographic military institute, 1875-1900). detail of the confluence between sinni river and sarmento river. c. cencetti & a. fredduzzi utilizzati (bell & vorst, 1981; tacconi, 1990). nel caso specifico, i parametri morfologico-planimetrici ritenuti più utili ai fini di un confronto storico sono: la larghezza dell'alveo attivo; l'indice di intrecciamento; l'estensione dei corpi sedimentari, evidenziandone lo stato vegetativo (barre nude, fortemente vegetate, arborate) che, come noto, è direttamente correlato alla loro mobilità. dato lo spiccato carattere b r a i d e d del f. sinni (fig. 3), altri parametri, più strettamente connessi con la sinuosità e con la tendenza del fiume a formare anse e meandri (indice di sinuosità, lunghezza del meandro, ampiezza del meandro, raggio di curvatura equivalente) sono stati tralasciati, poiché non ritenuti significativi. ciò è valido anche per gli indici che misurano la tendenza alla migrazione laterale, in quanto l'esame dei fotogrammi aerei evidenzia come nel 1954 l'alveo del f. sinni, per gran parte del tratto oggetto di studio, occupasse quasi completamente la propria pianura alluvionale (fig. 11). la larghezza dell'alveo attivo è il parametro che misura l'estensione della porzione di alveo non intensamente vegetata e caratterizzata dalla presenza di sedimenti ghiaiosi o sabbiosi (winterbottom, 2000). questo parametro può essere valutato sia come valore medio del tratto analizzato, sia come valore distribuito sulla lunghezza dell'alveo. nel primo caso il valore si ottiene come semplice rapporto tra l'area del poligono che rappresenta l'alveo attivo e la lunghezza del rispettivo asse. nel secondo caso, per ottenere un sistema di riferimento univoco, l'asse dell'alveo (la cui lunghezza varia nel tempo) viene suddiviso in un certo numero di parti. nel caso in questione, l'alveo del f. sinni nel tratto considerato è stato suddiviso in 382 parti: l'equidistanza, pari a circa 100 m, è ovviamente leggermente diversa per ognuno dei periodi considerati. tracciando in ognuno dei 382 punti un segmento normale all'asse dell'alveo e intersecandolo con il poligono che rappresenta l'alveo attivo si definisce la larghezza dell'alveo nel punto stesso (fig. 4 a). l'indice di intrecciamento (braiding index) è generalmente definito in letteratura come il numero medio (o massimo) di canali presenti in un tratto d'alveo di lunghezza uguale o superiore a circa 10 volte la larghezza media dell'alveo stesso; nel corso del tempo sono stati proposti diversi metodi di misura e stima di questo parametro (thorne, 1997). in questo lavoro l'indice di intrecciamento è stato ottenuto intersecando i segmenti tracciati per misurare la larghezza dell'alveo attivo con il poligono che identifica l'alveo di magra (in nero in figura 3). in questo modo il valore dell'indice è dato dal rapporto tra il numero di segmenti ottenuti dall'operazione di “intersezione” con l'alveo di magra (che è tanto più elevato quanto maggiore è il numero dei canali, fig. 4 b) ed il numero di segmenti originali (in pratica quelli in fig. 4 a) infine, come ultimo parametro, è stata misurata la superficie dei corpi sedimentari in funzione della presenza e del tipo di vegetazione. questo parametro non rappresenta un elemento tipicamente utilizzato in letteratura ma, nel caso in esame, è stato di grande aiuto per comprendere l'evoluzione del corso d'acqua (vedi paragrafo 4 “risultati ed interpretazione dei dati”). 151 fig. 3 analisi e digitalizzazione degli elementi morfologico-sedimentari (ortofotocarte 2003). gli elementi principali riportati in carta sono: 1) barre nude; 2) barre fortemente vegetate; 3) barre arborate; 4) canali di magra; 5) asse dell'alveo. analysis and drawing of the morphological-sedimentary elements (orthorectified aerial maps, 2003). the main elements are: 1) nude bars; 2) strongly vegetated bars; 3) bars whit arboreal vegetation; 4) low flow channels; 5) active riverbed axis. analisi attraverso metodologia gis ... 3. descrizione dello stato attuale dell'alveo tramite l'analisi e la fotointerpretazione delle ortofotocarte del 2003 e tramite sopralluoghi speditivi sul terreno è stato possibile individuare e cartografare i principali elementi morfologici, sedimentari ed antropici dell'alveo e della pianura alluvionale e quindi caratterizzare lo stato attuale del corso d'acqua. in questa fase si è rivelata molto utile la documentazione prodotta nell'ambito della “ricognizione di attività di polizia idraulica e controllo del territorio” eseguita dall'autorità di bacino della basilicata, in collaborazione con il dipartimento di ingegneria e fisica del l'ambiente del l'università degli studi del la basilicata, al fine di analizzare i punti potenzialmente critici del corso d'acqua, quali attraversamenti, canalizzazioni ed in genere tutte le opere trasversali e longitudinali (autorità interregionale di bacino della basilicata, 2004). la documentazione, prodotta nell'ambito di tale attività di studio e contenente dati e fotografie inerenti lo stato di conservazione di tutte le opere presenti in alveo, è stata utilizzata come base per verificare sul campo l'intensità dei processi erosivi ed in particolare l'entità dei fenomeni di incisione. inoltre, sempre l'autorità interregionale di bacino della basilicata, nell'anno 2003, ha portato a termine un campionamento dei sedimenti d'alveo del f. sinni, i cui dati sono stati messi gentilmente a disposizione degli autori. questo campionamento, consistito complessivamente nel prelievo dall'alveo di 293 campioni, 94 dei quali all'interno del tratto oggetto di studio e riferibili al canale principale, ha permesso di definire la distribuzione granulometrica dei sedimenti (fig. 5) e, in assenza di misure specifiche di trasporto solido di fondo, costituisce un importante punto di riferimento per la definizione dei caratteri sedimentari del corso d'acqua. sulla base dei dati acquisiti, la porzione del fiume oggetto di studio è stata suddivisa in tre tratti omogenei dal punto di vista morfologico-sedimentario (fig. 1). nel dettaglio, gli elementi che hanno maggiormente influito nell'individuazione dei tratti sono: l'estensione e la configurazione della pianura alluvionale; la configurazione morfologica dell'alveo; la distribuzione granulometrica dei sedimenti del canale. di seguito si riporta una breve descrizione dei tratti individuati. 3.1 tratto 1 in questo tratto il f. sinni è caratterizzato da una morfologia monocanale a barre alternate e presenta una debole tendenza a formare meandri: la sinuosità media è pari a 1,45 (fig. 6). per quasi tutto il tratto il fiume è confinato in una stretta valle alluvionale la cui larghezza varia tra un minimo di 100 m ed un massimo di 490 m; a valle della dorsale valsinni colobraro, la pianura alluvionale si fa più ampia (in media 800 m) ma il fiume rimane monocanale e meandriforme. i dati granulometrici indicano che i sedimenti del fondo dell'alveo sono estremamente grossolani ed eterogenei: il diametro medio dei clasti (ottenuto utilizzando tutti i campioni prelevati in questo tratto dall'adb della basilicata) è pari a circa 58 mm e numerosi campioni evidenziano la presenza di massi di notevoli dimensioni (fig. 5). in realtà, per i primi 7 km, dallo sbarramento fino alla confluenza con il f. sarmento, la portata è molto modesta e coincide col deflusso minimo vitale imposto in uscita dall'invaso; l'alveo risulta stretto (mediamente misura appena 30 m) e fortemente vegetato. il f. sarmento svolge un ruolo molto importante nella dinamica morfologico-sedimentaria del f. sinni, soprattutto se si considerano le condizioni in cui si trova il corso d'acqua dopo la costruzione dell'invaso di m. cotugno. il sarmento, infatti, non soltanto è l'affluente principale (il suo bacino rappresenta circa il 152 fig. 4 misura dell'indice di intrecciamento. in a) sono riportati i segmenti ed il poligono (linea tratteggiata) che rappresentano l'alveo attivo ; in b) sono riportati i segmenti riferibili ai canali di magra. measure of the braiding index. the polygon and the segments that represent the active riverbed (a) and the segments related to the low flow channels ( b) are highlighted. c. cencetti & a. fredduzzi 153 fig. 5 variazione del diametro medio dei sedimenti d'alveo. le distanze progressive sono misurate a partire dalla diga di m. cotugno. variation of the mean diameter of the riverbed sediments. the progressive distances are measured starting from the mt. cotugno dam. fig. 6 rappresentazione planimetrica del tratto 1. in bianco sono evidenziati i canali di magra (la base topografica è l'ortofotocarta del 2003). planimetric view of the reach 1. the white line highlights the low flow channels. (the topographic map is the orthorectified aerial map, 2003). 22% dell'intero bacino idrografico del sinni), ma presenta anch'esso un alveo ghiaioso, caratterizzato da un trasporto solido molto elevato; forma infatti un ampio conoide in corrispondenza della confluenza ed è caratterizzato da portate idriche paragonabili a quelle del suo recipiente. quanto detto si riflette sulla granulometria dei sedimenti d'alveo: il grafico di figura 5 mostra come il diametro medio dei sedimenti del canale subisca un incremento molto consistente proprio in corrispondenza della conoide del f. sarmento. il valore massimo dello stesso grafico si riferisce al campione prelevato in corrispondenza della sezione denominata sz-sb 167, localizzata nel punto in cui il fiume attraversa la dorsale valsinni colobraro e lambisce i versanti su cui affiorano le formazioni terrigene cretacico-mioceniche del flysch numidico e della formazione di serra palazzo (fig. 7): la vicinanza dei versanti, caratterizzati dall'affioramento delle suddette formazioni litoidi, spiega l'elevata frequenza di massi arenacei di notevoli dimensioni che si riscontrano nell'alveo e nel canale. analisi attraverso metodologia gis ... nella prima parte del tratto, dallo sbarramento alla confluenza con il sarmento, si rileva una debole tendenza all'approfondimento del fondo dell'alveo (evidenziata, ad esempio, dallo scalzamento della fondazione di un viadotto). questo fenomeno, dovuto in genere ad un deficit sedimentario, è comunque poco marcato, in quanto le portate idriche sono mantenute piuttosto basse dall'esercizio dell'invaso situato a monte. a valle della confluenza con il sarmento il corso d'acqua si presenta in condizioni migliori dal punto di vista morfologico-sedimentario: l'alveo è in equilibrio con la pianura alluvionale (sponde basse) e non si riscontrano fenomeni di incisione. tutto ciò è senza dubbio dovuto ai consistenti apporti sedimentari dello stesso sarmento. 3.2 tratto 2 in questo tratto, che si estende complessivamente per circa 12,7 km sino alla traversa di s. laura, il tracciato del f. sinni assume una morfologia spiccatamente multicanale (b r a i d e d) con un elevato grado di intrecciamento e si espande notevolmente nella pianura alluvionale: la larghezza dell'alveo misura in media 270 m ed in alcuni punti supera i 700 m (fig. 8). anche la valle è molto ampia (in media 2 km) ed è delimitata da blandi versanti collinari su cui affiorano i litotipi argillosi e sabbiosi del plio-pleistocene. i sedimenti dell'alveo sono molto eterogenei (dal limo alla ghiaia), ma nettamente meno grossolani rispetto al tratto precedente: il diametro medio dei clasti, ottenuto utilizzando i dati di tutti i campioni prelevati in questo tratto, è pari a circa 32 mm. l'alveo è caratterizzato da sponde non eccessivamente alte (da 1,5 a 4 m) ed anche in questo caso non si rilevano evidenti segni di incisione ed approfondimento del fondo. ciò è messo in evidenza dalle condizioni delle pile del “ponte tubo” in località caramola, che non mostrano segni di scalzamento delle loro fondazioni. nei tre chilometri terminali la pendenza diminuisce bruscamente, per effetto della presenza della traversa di s. laura, realizzata nel 1953 e, allo stato attuale, completamente interrita. il rallentamento della corrente e la conseguente deposizione dei sedimenti più fini hanno favorito l'attecchimento della vegetazione che ricopre l'alveo quasi completamente. 154 fig. 7 schema litologico-formazionale dell'area del bacino del f. sinni. legenda: 1) alluvioni recenti ed attuali (olocene); 2) sedimenti clastici continentali (pliocene-pleistocene); 3) formazione di serra palazzo (miocene inferiore-medio); 4) flysch di gorgoglione (miocene inferiore-medio); 5) flysch numidico (miocene inferiore); 6) unità liguridi (cretaceo-miocene inferiore); 7) piattaforma appenninica (trias-miocene inferiore); 8) piattaforma apula (trias-paleogene); 9) successioni lagonegresi (trias-cretaceo). da autorità interregionale di bacino della basilicata, 2007 (ridisegnato e semplificato). lithological-formational sketch of the area including the watershed of sinni river. legenda: 1) recent and present alluvial sediments (olocene); 2) continental clastic sediments (pliocene-pleistocene); 3) serra palazzo formation (lower-middle miocene); 4) gorgoglione flysch (lower-middle miocene); 5) numidic flysch (lower miocene); 6) ligurides units (cretaceous lower miocene); 7) apenninic platform (triassic lower miocene); 8) apul platform (triassic paleogene); 9) lagonegro successions (triassic cretaceous). from autorità interregionale di bacino della basilicata, 2007 (redrawn and semplified). c. cencetti & a. fredduzzi 3.3 tratto 3 l'ultimo tratto si estende a partire dalla traversa di s. laura fino alla foce nel mar ionio ed è lungo complessivamente 10,7 km (fig. 9). in questo tratto il corso d'acqua torna ad assumere una morfologia monocanale a barre alternate (w a n d er i n g). è caratterizzato da una sinuosità piuttosto bassa (1,15) e si restringe notevolmente, mostrando una larghezza dell'alveo attivo mediamente pari a 37,5 m. dopo circa 2,5 km, l'alveo lambisce il versante in destra idrografica, costituito dalle formazioni plio-pleistocenche che, più a valle, lasciano il posto ai terrazzi marini del pleistocene superiore. nel tratto in prossimità della foce il corso d'acqua scorre attraversando la pianura costiera, costituita dai depositi marini olocenici. le foto aeree del volo g.a.i. (1954) ed anche la carta igm (1875-1900) evidenziano come, sulla pianura alluvionale in sinistra idrografica, fosse presente un bosco planiziale ormai relitto (bosco del pantano). attualmente gran parte di quest'area boschiva è stata sostituita da campi coltivati; un'ultima traccia rimane oggi solo nei pressi della foce. per quanto riguarda la granulometria dei sedimenti d'alveo, si assiste ad un ulteriore decremento delle dimensioni dei clasti (fig. 5). ciò è dovuto principalmente alla bassa pendenza del fondo, considerata la prossimità della foce: il diametro medio dei sedimenti del canale (ottenuto utilizzando tutti i campioni prelevati in questo tratto) è pari a circa 8,5 mm. va considerato, inoltre, l'effetto della traversa di s. laura che ha trattenuto totalmente il trasporto solido di fondo, sino al suo completo interrimento. allo stato attuale la briglia non svolge più questa funzione di interruzione del c o n t in u u m sedimentario; tuttavia i materiali più grossolani vengono comunque depositati nel tratto a monte, a causa della netta diminuzione di pendenza dell'alveo. in questo tratto si rileva un grado di incisione e di approfondimento del fondo molto marcato, evidenziato dagli stessi caratteri morfologico-sedimentari dell'alveo: i corpi sedimentari sono frequentemente occupati da vegetazione arborea e spesso sospesi; inoltre, le sponde dell'alveo sono alte e soggette a processi di erosione laterale diffusi. lo stato di conservazione dei manufatti presenti in alveo costituisce un'ulteriore indicazione 155 fig. 8 rappresentazione planimetrica del tratto 2. in nero sono evidenziati i canali di magra (la base topografica è sempre l'ortofotocarta del 2003). planimetric view of the reach 2. the black line highlights the low flow channels. (the topographic map is the orthorectified aerial map, 2003). fig. 9 rappresentazione planimetrica del tratto 3, in bianco sono evidenziati i canali (base topografica ortofoto 2003). planimetric view of the reach 3. the white line highlights the low flow channels. (the topographic map is the orthorectified aerial map 2003). analisi attraverso metodologia gis ... di tale tendenza all'approfondimento: la platea di fondazione della traversa di s. laura e le pile del “ponte tubo” in località pantanello, ad esempio, appaiono scalzate per oltre un metro (fig. 10). 4. risultati e interpretazione dei dati l'analisi storico-cartografica dell'alveo del f. sinni a valle della diga di m. cotugno ha consentito di quantificare le variazioni planimetriche verificatesi nell'ultimo cinquantennio. i risultati mostrano che dal 1954 al 2003 si è verificata una forte riduzione della larghezza media dell'alveo attivo (da 425 m a 110 m), accompagnata da una netta diminuzione dell'indice di intrecciamento (da 3,1 a 1,7). un altro cambiamento molto evidente riguarda lo stato vegetativo dei corpi sedimentari in quanto, a fronte di un generale restringimento dell'alveo, la superficie delle barre fortemente vegetate e/o arborate si è praticamente triplicata: nel 1954 queste occupavano soltanto il 28,3 % dell'alveo, mentre nel 2003 ne occupavano l'83,3 % (fig. 11). la trasformazione più importante si è verificata nel tratto terminale a valle della traversa di santa laura (lungo circa 11 km), dove la configurazione morfologica dell'alveo è completamente cambiata: il corso d'acqua è passato da una tipologia multicanale intrecciata ad una monocanale a barre alternate (fig. 12). l'analisi delle carte igm (1875-1900) che, sebbene non forniscano indicazioni sulla vegetazione, permettono di determinare larghezza e grado di intrecciamento dell'alveo, in quanto sono riportati i corpi sedimentari (fig. 2), dimostra come questi cambiamenti siano iniziati successivamente al 1954. quest'ultimo dato, vale a dire la velocità dei processi evidenziati dall'analisi storica, costituisce un primo importante indizio sulla natura antropica delle cause che li hanno prodotti, in quanto i fattori naturali, tranne rare eccezioni che rientrano comunque nella categoria degli eventi catastrofici, agiscono in maniera estremamente lenta tanto che, spesso, le modificazioni 156 fig. 10 effetti dei processi di erosione ed incisione nell'ultimo tratto del f. sinni. a sinistra si vede lo scalzamento al piede della traversa di s. laura, mentre a destra l'incisione è evidenziata dalle condizioni critiche del pilone di un ponte. effects of the erosional processes in the final reach of sinni river. on the left the s. laura check dam is shown; on the right the downcutting is highlighted by the critical conditions of a bridge pylon left. fig. 11 confronto storico relativo ad una porzione dell'alveo a monte della traversa di s. laura. historical comparison related to a reach upstream the s. laura check dam. c. cencetti & a. fredduzzi prodotte non sono apprezzabili alla scala della vita umana. entrando nel dettaglio e mettendo in relazione i cambiamenti evidenziati dall'analisi storica con le caratteristiche morfo-sedimentarie attuali dell'alveo (definite in base ai rilevamenti diretti sul terreno), emerge come la trasformazione del corso d'acqua si sia verificata con modalità diverse lungo il tratto studiato. nella prima parte, dalla confluenza con il tributario più importante (t. sarmento) sino alla traversa di s. laura, per una lunghezza di circa 27 km, il restringimento dell'alveo attivo è dovuto alla riduzione delle portate liquide che ha comportato il progressivo abbandono dei corpi sedimentari e la loro progressiva stabilizzazione (barre arborate), ma non si riscontrano fenomeni di erosione verticale e di incisione. di norma, la presenza di processi di tal genere indica condizioni di instabilità e disequilibrio dell'alveo, dovuti ad un esubero di stream power (cioè della capacità di trasporto dei sedimenti rispetto alla quantità di materiale a disposizione per il trasporto solido). sono, pertanto, processi che indicano un deficit sedimentario; la loro assenza, nel caso in esame, va considerata indicativa di una condizione di sostanziale stabilità dell'alveo del f. sinni. l'analisi storica ed il rilevamento dell'alveo evidenziano, in sintesi, come nel tratto a valle della confluenza con il t. sarmento sino alla traversa di s. laura, si sia ridotta in maniera consistente l'area di pertinenza del corso d'acqua e come questo sia avvenuto senza che si sia instaurata alcuna condizione di instabilità e disequilibrio del sistema fluviale. come già detto, tutto ciò è imputabile essenzialmente ad una consistente riduzione delle portate liquide del corso d'acqua. sebbene non sia possibile escludere che tale riduzione delle portate possa essere connessa ad una variazione del regime pluviometrico e, quindi, più in generale ad un fattore di carattere climatico, è ragionevole affermare che tale causa possa essere ritenuta trascurabile rispetto all'impatto che la realizzazione di un invaso da 530 milioni di m3 ha avuto sul regime idrologico del f. sinni. le buone condizioni morfologico-sedimentarie dell'alveo in questo tratto sono dovute al fatto che l'interruzione del continuum sedimentario, prodotta dall'esercizio della diga di m. cotugno, è in qualche modo compensata dalla diminuzione di portata liquida e dalla modulazione dei deflussi idrici operata dalla diga stessa (che comunque ha determinato la riduzione dell'area attiva dell'alveo), nonché dal cospicuo apporto solido del t. sarmento. la situazione è completamente diversa negli ultimi 11 km del corso d'acqua (dalla traversa di s. laura sino alla foce) dove il restringimento, invece, è stato accompagnato proprio da una consistente incisione dell'alveo e da processi diffusi di erosione, sia verticale che laterale, che hanno comportato e comportano tuttora una generale condizione di dissesto dell'alveo (fig. 10). infatti è stato prodotto, in questo tratto, un completo stravolgimento delle condizioni naturali del corso d'acqua che è passato da una morfologia multicanale tipicamente intrecciata (analoga a quella che tutt'oggi caratterizza la porzione a monte) ad una morfologia monocanale a barre alternate (wandering). in pratica, a valle della traversa, nessun elemento ha concorso a mitigare il deficit sedimentario poiché, come noto, una briglia blocca il trasporto solido, ma 157 fig. 12 confronto storico relativo ad una porzione dell'alveo a valle della traversa di s. laura. historical comparison related to a reach downstream the s. laura check dam. analisi attraverso metodologia gis ... non ha la capacità di laminare le piene; inoltre, a valle della stessa, non si riscontra la presenza di affluenti importanti che possano rifornire di materiale l'alveo del collettore principale. soprattutto in questo caso la velocità con la quale la trasformazione si è verificata denota senz'altro una causa antropica: si può affermare che le foto aeree del volo g.a.i. (1954) identificano la configurazione morfologica appena antecedente l'inizio dei processi suddetti; infatti la costruzione della traversa di s. laura è stata ultimata nel 1955, mentre la realizzazione della diga è più recente (1983). la trasformazione subita dal corso d'acqua in questo tratto si inserisce in un'ampia letteratura che riguarda le variazioni morfologiche dei fiumi europei e, in particolare, dei fiumi italiani. numerosi studi, infatti, hanno messo in evidenza come processi quali l'abbassamento del fondo, il restringimento dell'alveo nonché il cambiamento della configurazione morfologica abbiano interessato, soprattutto nel corso degli ultimi decenni, la gran parte dei fiumi italiani (maraga & mortara, 1981; gentili & pambianchi, 1987; becchi & paris, 1989; braga & ge r v a s o n i, 1989; ta c c o n i & bi l l i, 1990; ce n c e t t i e t al., 1991, 1994, 2002, 2004; coltorti et al., 1991; canut i et al., 1992, 1994; ma r a g a, 1992; la m b e r t i, 1993; dutto & maraga, 1994; billi et al., 1994; sabato, 1994; castaldini & piacente, 1995; capelli et al., 1997; surian, 1999; aucelli & rosskopf, 2000; marchetti, 2002; burnelli et al., 2003; surian & rinaldi, 2003). in particolare, facendo riferimento allo schema (fig. 13) proposto da surian & rinaldi (2003), la trasformazione dell'alveo nell'ultimo tratto corrisponde al passaggio dalla tipologia c, ossia dei fiumi a canali intrecciati, alla tipologia transizionale f (alvei sinuosi a barre alternate). le cause che generalmente gli autori individuano come responsabili delle variazioni morfologiche sono essenzialmente di natura antropica e sono riconducibili a interventi localizzabili sia a scala di bacino sia a scala di alveo (o di tratto). per riassumere sinteticamente si possono citare: le variazioni dell'uso del suolo (dovute al progressivo abbandono delle pratiche agricole o agli interventi di riforestazione), l'estrazione di inerti in alveo e nella pianura alluvionale, la realizzazione di dighe e opere di sbarramento in genere (come briglie e traverse che spesso pervadono diffusamente gli alvei fluviali), la realizzazione di opere di difesa e di canalizzazione del flusso. sebbene altri autori abbiano mostrato come anche le variazioni climatiche (ed in particolare l'effetto delle stesse sull'intensità e sulla frequenza degli eventi di piena) possano giocare un ruolo importante sull'instabilità degli alvei (knox, 1983; rumsby & macklin, 1994), è ben difficile individuarne gli effetti soprattutto in un territorio, come quello italiano, dove le conseguenze dei molteplici impatti antropici perpetrati nel tempo sono molto più evidenti. tornando allo specifico del f. sinni, tra le cause che hanno portato alla situazione attuale e che è stato possibile in prima analisi accertare, vanno citate, oltre alle suddette opere trasversali, la realizzazione di opere di canalizzazione del flusso (arginature e difese spondali) e l'estrazione diretta di inerti dall'alveo. quest'ultima è stata perpetrata per anni in maniera veramente ingente, soprattutto nel tratto terminale, quello attualmente più in crisi. le stime indirette, realizzate sulla base della stima dei volumi di materiali necessari alla costruzione di grandi opere, strade di fondo valle e dighe per il periodo che va dal 1965 al 1977, sono pari a circa 15 milioni di m3 ( co c c o et al. , 1978). a questi possono essere aggiunti altri 2,5 milioni di m3 calcolati, probabilmente per difetto, in base alle autorizzazioni concesse tra il 1978 ed il 1992 (spilotro et al., 2000). ringraziamenti gli autori desiderano ringraziare il personale tecnico dell'autorità interregionale di bacino della basilicata ed in particolare il segretario generale ing. michele vita, per aver messo gentilmente a disposizione tutti i dati cartografici, topografici e sedimentologici in possesso dell'adb, risultati utilissimi ai fini del presente studio. 158 fig. 13 schema di classificazione delle variazioni morfologiche degli alvei dei fiumi italiani (da surian & rinaldi, 2003). classification of morphological variations of italian riverbeds (from surian & rinaldi, 2003). c. cencetti & a. fredduzzi 5. riferimenti bibliografici aucelli p.p.c. & rosskopf c. (2000) last century valley floor modifications of the trigno river (southern italy): a preliminary report. geogr. fis. dinam. quat., 23, 105-115. autorità interregionale di bacino della basilicata (2004) ricognizione di attività di polizia idraulica e control lo del terri tor io . rapporto tecnico, h t t p : / / w w w . a d b . b a s i l i c a t a . i t / a d b / p o l i z i a / c i c l o 2 0 0 4 .asp . autorità interregionale di bacino della basilicata (2007) relazione sul piano stralcio per la difesa dal rischio idrogeologico . segreteria tecnica operativa dell'adb della basilicata (potenza), 169 pp. h t t p : / / w w w . a d b . b a s i l i c a t a . i t / a d b / p s t r a l c i o / r e l az i one07.asp becchi i. & paris e. (1989) il corso dell'arno e la sua evoluzione storica. acqua aria, 6 , 645-652. bell f.c. & vorst p.c. (1981) geomorphic parameters of representatives basins and their hydrologic s i g n i f i c a n c e . in australian water resource counci l technical paper, 5 8 . austral ia government publishing service, canberra. billi p., chiaverini i. & ostuni d. (1994) studi preliminari su degradazione fisica e stabilità dell'alveo del f. cecina. il quaternario, 7 (1), 311-316. bovee k.d. (2004) a guide to stream habitat analysis using the instream flow incremental m e t h o d o l o g y . instream flow information, paper 12, fws/obs-82/26, co-operative instream group, us fish and wildlife service, office of biological services. braga g. & ge r v a s o n i s. (1989) evolution of the po river: an example of the application of historic maps. in: petts, g.e., moller, h., roux, a.l. (eds.) “historical change of large alluvial rivers: western europe”, wiley, pp. 113-126. br a v a r d j., am o r r o s c., pa t o u g., bo r n e t t e g., bo rn a u d m., cr e u z e de s ch a t e l l i e r m., gi l b e r t j . , pe i r y j., pe r r i n j., ta c h e t h. (1997) river incision in south-east france: morphological phenomena and ecological effects. regulated rivers: research and management, 13, 75-90. burnelli a., cencetti c. & marchesini i. (2003) il bacino del t. spina (umbria centro-orientale): analisi dei caratteri morfologici e sedimentari dell'alveo, interventi antropici e condizioni di rischio geologic o i d r a u l i c o. atti del 1° congresso nazionale aiga (chieti, 19-20 febbraio 2003), 113-126. rendina editori, roma, isbn: 88-86698-40-2. canuti p., cencetti c., conversini p., rinaldi m. & tacconi p. (1992) dinamica fluviale recente di alcuni tratti dei fiumi arno e tevere. atti del convegno “fenomeni di erosione e alluvionamenti degli alvei fluviali” (ancona, 14-15 ottobre 1991), 21-35. canuti p., cencetti c., rnaldi m. & tacconi p. (1994) the f luvial dynamics of the arno river 2. historical evolution of the arno river bed. m e m . soc. geol. it., 48, 851-864. capelli g., miccadei e. & raffi r. (1997) fluvial dynamics in the castel di sangro plain: morphological changes and human impact from 1875 to 1992. catena, 30, 295-309. castaldini d. & piacente s. (1995) channel changes on the po river, mantova province, northern italy. in: hickin, e.j. (ed.) “river geomorphology”, wiley, 193-207. ce n c e t t i c. (2002) la cartografia storica come strumento per lo studio dell'evoluzione degli alvei fluv i a l i . atti della 6a conferenza nazionale asita “geomatica per l'ambiente, il terr itorio e il patrimonio culturale” (perugia, 5-8 novembre 2002), 757-762. cencetti c., conversini p., martani c. & nejad massoum m. (1991) considerazioni sulla dinamica fluviale del f. tevere nel tratto tosco-umbro compreso tra l'invaso di montedoglio e s. lucia. ricerca scientifica ed educazione permanente, suppl. 93, 527536. cencetti c., tacconi p. & conversini p. (1994) attività antropica e dinamica fluviale nell'alta val tiberina. atti del “1° convegno internazionale per la protezione e lo sviluppo dell'ambiente montano man and mountain '94” (ponte di legno, 20-24 giugno 1994), 631-656. ce n c e t t i c., fr e d d u z z i a. & ma r c h e s i n i i. (2002) evoluzione e dinamica dell'alveo del torrente chiani (umbria): problemi di rischio geologicoidraulico e di conservazione dell'ambiente fisico. atti del convegno nazionale “conservazione dell'ambiente e rischio idrogeologico” (assisi, 11-12 dicembre 2002). cnr-gndci, pubbl. n. 2830, 108-120. ce n c e t t i c., fr e d d u z z i a. & ma r c h e s i n i i. (2004) processi di erosione negli alvei ghiaiosi dell'italia centrale. il fiume paglia (bacino del tevere). atti del la 8a conferenza asita “geomatica standardizzazione, interoperabilità e nuove tecnologie “ (fiera di roma, 14-17 dicembre 2004), vol. i, 731-736. isbn: 88-900943-6-2. co c c o e., de magistris m.a. & de pi p p o t. (1978) studi sulle cause dell'arretramento della costa lucana ionica: i. l'estrazione degli inerti lungo le aste fluviali. mem. soc. geol. it., 4, 421-428. co l t o r t i m., na n n i t. & vi v a l d a p. (1991) la bassa valle del fiume musone (marche): geomorfologia e fattori antropici nell'evoluzione della pianura alluvionale. geogr. fis. dinam. quat., 14, 101-111. dutto f. & maraga f. (1994) variazioni idrografiche e condizionamento antropico. esempi in pianura padana. il quaternario, 7, 381-390. gentili b. & pambianchi g. (1987) morfogenesi fluviale ed attività antropica nelle marche centro-meridionali. geogr. fis. dinam. quat., 10 , 204-217. gu r n e l l a.m., pe i r y j.l., pe t t s g.e. (2003) u s i n g historical data. in: kondolf g.m. and piegay h. (ed) “tools in fluvial geomorphology”. john wiley & sons ltd, 77-101. kn o x j.c. (1983) responses of river systems to holocene climates. in: wright, h.e. (ed) “late quaternary environments of the united states. vol.2, the holocene”. university of minnesota press, minneapolis, 26-41. lamberti a. (1993) le modificazioni recenti verificatesi nell'asta principale del po e problemi connessi. acqua-aria, 6, 589-592. le y s f. & we r r i t t y a. (1999) river channel planform change: software for histor ical analysis. geomorphology, 29, 107-120. 159analisi attraverso metodologia gis ... maraga f. (1992) riduzione del campo di attività fluviale e disponibilità di sedimento nei tratti d'alveo pluricursali: casi di studio nella pianura padana. atti del convegno “fenomeni di erosione e alluvionamenti degli alvei fluviali” (ancona, 14-15 ottobre 1991), 51-62. ma r a g a f. & mo r t a r a g. (1981) le cave per inerti lungo i corsi d'acqua: rapporti con la dinamica fluviale. boll. ass. min. subalp., 18, 3-4, 385-395. ma r c h e t t i m. (2002) environmental changes in the central po plain (northern italy) due to fluvial modifications and anthropogenic activi t ies. geomorphology, 44, 361-373. neteler m. & mitasova h. (2002) open source gis a grass gis approach . kluwer academic publishers, boston. ru m s b y b.t. & ma c k l i n m.g. (1994) channel and floodplain response to recent abrupt climate change; the tyne basin, northern england. earth surf. proc. and land., 19, 499-515. sa b a t o l. (1994) human impact on alluvial environments in calabria (southern italy). mem. soc. geol. it., 48, 935-941. sp i l o t r o g., di br a t t o m., ce c i l i a g. & le a n d r o g . (2000) evoluzione recente del litorale alto ionico compreso tra foce sinni e foce bradano . rapporto la.t.i.b.i., linea 17, n. 1, università di bari. surian n. (1999) channel changes due to river regulation: the case of the piave river, italy. earth surf. proc. and land., 24, 1135-1151. su r i a n n. (2002) utilizzo di cartografia storica nello studio del la dinamica fluviale . atti del la 6° conferenza nazionale asita “geomatica per l'ambiente, il territorio e il patrimonio culturale” (perugia, 5-8 novembre 2002), 1925-1930. surian n. & rinaldi m. (2003) morphological response to river engineering and management in alluvial channels in italy. geomorphology, 50, 4, 307-326. ta c c o n i p. (1990) la dinamica fluviale. atti del vii congresso nazionale dell'ordine dei geologi, (roma, 25-27 ottobre 1990), 29-42. ta c c o n i p. & bi l l i p. (1990) indagine sull'abbassamento del fiume po. analisi morfometrica dello stato attuale e tendenza evolutiva dell'alveo. po acquagricolturambiente, vol. i i: “l'alveo e il delta”, società editrice il mulino, bologna, 15111. thorne c. l. (1997) channel types and morphological c l a s s i f i c a t i o n”. in thorne c. r., hey r. d. & newson m. d. (eds) “applied fluvial geomorphology for river engineering and management”. john wiley & sons, chichester. wi n t e r b o t t o m s. j. (2000) medium and short-term channel planform changes on the river tay and tummel, scotland. geomorphology, 34, 195-208. 160 ms. ricevuto il 20 febbraio 2008 testo definitivo ricevuto il 30 maggio 2008 ms. received: february 20, 2008 final text received: may 30, 2008 c. cencetti & a. fredduzzi caesar: un modello per la simulazione delle dinamiche d'alveo thomas coulthard1, pierluigi de rosa2 & ivan marchesini2 1department of geography, university of hull (uk) 2dipartimento di ingegneria civile ed ambientale, università di perugia e-mail: pierluigi.dr@alice.it riassunto: coulthard t., de rosa p., marchesini i.: caesar: un modello per la simulazione delle dinamiche d'alveo. (it issn 03943356, 2008). ceasar è un modello bidimensionale di tipo cellular automata, sviluppato per simulare le modificazioni morfologiche di un corso d'acqua. il modello agisce per iterazioni successive, durante le quali il dem del bacino viene modificato in accordo con il flusso idrico e di sedimenti e/o con l'intensità di pioggia immessa. caesar è stato inizialmente progettato per simulare le risposte geomorfologiche di un bacino ai cambiamenti climatici o di uso del suolo per passi temporali molto grandi. sviluppi più recenti hanno permesso al modello di simulare situazioni anche più complesse (es. fiumi meandriformi) e per piccole scale temporali. caesar divide il bacino in celle, ognuna avente un proprio valore di quota, portata idrica, battente idrico, vegetazione, profondità del bedrock e granulometria. per ogni iterazione il modello aggiorna questi valori in accordo con regole proprie e tenendo conto delle interazioni con le celle vicine. caesar ha 4 tipologie di set di regole: • regole idrologiche • regole di erosione e sedimentazione fluviale • processi di versante • processi vegetativi nel presente lavoro si mostrano le capacità di questo modello con alcune applicazioni per prevedere gli effetti che possono avere le opere idrauliche sul fiume e sulla pianura alluvionale. abstract: coulthard t., de rosa p., marchesini i.: caesar: a model to simulate river dynamics. (it issn 03943356, 2008). caesar is a two dimensional ca (cellular automata) model used to simulate the morphological changes of watersheds and rivers. for every model iteration, a dem of a river basin is modified according to the water and sediment fluxes and/or to the rainfall data entered by the user. caesar was initially designed to simulate the geomorphologic response of river catchment to changes in climate or land cover for relevant time scales. more recent developments of the model allows users to model over smaller time and space scales and in more complex morphological situation (river meandering, for example). this paper aims to describe caesar and its capabilities to the italian scientific community, where it is still almost unknown. some applications are shown to simulate the presence of hydraulics works interfering with the stream. a flow and sediment transport model indeed allows to better evaluate the functionality of hydraulic features of the river and to forecast its effects on the river bed-alluvial plain system. parole chiave: modellistica fluviale, cellular automata, dinamica fluviale. keywords: river modelling, cellular automata, fluvial dynamics. il quaternario italian journal of quaternary sciences 21(1b), 2008 207-214 1. breve cenno ai modelli fluviali “a celle” i modelli “a celle” vengono utilizzati in geomorfologia per rappresentare il territorio attraverso una griglia di celle. le modificazioni morfologiche del rilievo sono determinate proprio dalle interazioni tra le varie celle, che seguono regole basate su equazioni semplificate dei processi fisici che intervengono. in particolare nello studio geomorfologico dei fiumi, i modelli a celle utilizzano adattamenti semplificati o relazionati delle complesse equazioni utilizzate nei model li cfd (computational fluid dynamics). ciò permette di incrementare le potenzialità dei modelli a celle, in quanto velocizza le operazioni computazionali ed inoltre permette di includere nel modello i processi di trasporto solido tra celle. il primo di tali modelli è stato quello implementato da murray e paola (mu r r a y & pa o l a, 1994) che simulava l'evoluzione di un fiume braided sotto l'effetto della portata liquida che attraversava una griglia di celle che rappresentava il canale. l'erosione di tali celle avveniva secondo semplici regole di portataerosione ed il materiale eroso veniva trasportato nelle celle adiacenti a seconda della pendenza stabilita. questo semplice modello non solo permise di ottenere un flusso divergente o convergente ma, ben più importante, la larghezza del canale veniva rappresentata attraverso una o più celle. non erano presenti invece calcoli della profondità o della velocità del flusso; tuttavia i risultati che vennero ottenuti per i fiumi braided furono qualitativamente realistici. con tale modello è stato possibile riprodurre il comportamento di un canale braided con migrazione di barre e canali verso valle e lateralmente. murray e paola hanno ricreato le condizioni che portano un fiume ad intrecciarsi: flussi non confinati lateralmente, materiale mobile sul fondo e sponde in erosione, semplificando così le leggi fisiche che sono all'origine di tale fenomeno. benché molto semplice, tale modello ha rappresentato storicamente un importante approccio per i ricercatori, in quanto è stato precursore di ulteriori implementazioni migliorative dello stesso. 1. 1 caesar caesar si è ispirato proprio al modello di murray e paola. caesar, per le sue peculiarità, appartiene alla 208 coulthard et al. categoria di modelli bidimensionali a celle che riescono a colmare meglio il gap esistente tra i modelli cdf 2d e 3d (ni c h o l a s, 2005) che sono spesso difficilmente applicabili a scala di bacino o per time scale maggiori di un singolo evento. caesar è un modello bidimensionale, di tipo cellular automata, che simula l'evoluzione morfologica del territorio dovuta agli effetti delle dinamiche d'alveo, utilizzando come input il dem di un alveo a scala di bacino o tratto, portate solide e liquide e dati di pioggia. caesar, implementando al suo interno un modello di trasporto dei sedimenti, è in grado di simulare i cambiamenti morfologici sia di un alveo che del reticolo idrografico. grazie all'utilizzo della “funzione tracciante” è possibile seguire i percorsi dei diversi tipi di sedimenti, la loro diffusione e concentrazione a valle. inizialmente, il software era stato progettato per studiare le variazioni morfologiche di un bacino idrografico su lunghe scale temporali a seguito di cambiamenti climatici e/o dell'uso del suolo (coulthard et al., 2002). per ogni cella rappresentante il bacino o il tratto fluviale caesar gestisce proprietà quali la quota, la portata idrica e il battente, la copertura vegetale, la profondità del bedrock e la granulometria. il modello utilizza il concetto di “automazione cellulare”, per cui ripetute iterazioni di una serie di regole su ognuna delle celle conducono ad un'evoluzione del territorio indicando il comportamento dell'intero sistema. caesar ha una serie di regole che possiamo raggruppare in: 1. regole idrologiche 2. regole di routing di portata 3. regole per l'erosione e la sedimentazione fluviale 4. regole per i processi di versante per ogni iterazione caesar modifica i valori delle proprietà della cella analizzata, al passo temporale precedente, in accordo con i set di regole appena elencati e con i valori delle proprietà delle celle adiacenti. questo significa che, ad esempio, la quantità totale di erosione di una cella viene a dipendere dal battente idrico della cella e dalla pendenza tra la stessa celle e quelle adiacenti. caesar può funzionare sia a scala di bacino idrografico che a scala d'alveo; a scala di bacino utilizza come input una pioggia oraria, costante su tutto il bacino, che diventa poi portata defluente attraverso l'utilizzo, come modello afflussi-deflussi, di un topmodel modificato. qualora si volesse utilizzare caesar a scala di tratto, l'input richiesto dal modello è rappresentato dalle portate (solide e liquide) in ingresso. per ogni scan (dove per s c a n si indica la scansione e l'aggiornamento dei valori di tutte le celle del territorio per un dato passo temporale) il flusso idrico (sia che si operi a scala di tratto che a scala di bacino) è indirizzato verso le tre celle idraulicamente più a valle (fig. 1) ma, se il flusso idrico totale è maggiore del flusso subsuperficiale, l'eccesso è trattato come deflusso e di conseguenza viene calcolato anche il battente attraverso un adattamento dell'equazione di manning: 23q = u . a = (h . √–s . a) (eq 1) dove q, u e h rappresentano rispettivamente la portata, la velocità di flusso e il battente idrico, a è l'area della sezione trasversale del flusso, s è la pendenza. per le celle per cui è stato calcolato il battente, viene quindi calcolato il tasso di erosione e sedimentazione fluviale attraverso l'equazione di wilcock e crowe ( wi l c o c k & cr o w e, 2003) applicata ad undici diverse frazioni granulometriche (da 1 a 256 mm) che definiscono la granulometria del letto dell'aveo a sua volta suddiviso in una serie di 10 layers attivi (secondo l'approccio di hoey & ferguson, 1994). a seconda delle dimensioni i diversi clasti sono trasportati sia come carico di fondo che come sedimenti sospesi, determinando la creazione di una superficie “corazzata” (armoured) e di una stratificazione del fondo. quando si effettuano simulazioni molto lunghe è necessario assicurarsi che si siano depositati sedimenti più fini che fungeranno da “risorse” per i processi di erosione futuri. il principale “motore” del modello, responsabile delle modificazioni morfologiche che avvengono nell'alveo, è legato ai processi di presa in carico, trasporto e sedimentazione dei materiali. il processo di trasporto è guidato da una formula “mixed-size”, che calcola il tasso di trasporto per ogni i-esima classe granulometrica di sedimenti (wi lcock & crowe, 2003): fig. 1 schema dell'algoritmo di scan del modello digitale del terreno utilizzato da ceasar (tratto da coulthard et al., 2002). schematic diagram of the caesar scanning flow routing algorithm (from co u l t h a r d et al., 2002). fi . u3 . w* i qi = –––––––––––– (eq 2) (s-1) . g dove fi rappresenta la frazione di volume dell' i-esima classe granulometrica nel layer attivo, u è la shear velocity, s il rapporto tra la densità dei sedimenti e dell'acqua, g è la costante gravitazionale e w* i è una funzione complessa che mette in relazione il tasso di trasporto della frazione granulometrica con il tasso di trasporto totale. allo stato attuale, nel codice sono presenti anche regole per i processi di versante. questi tipi di processi sono limitati a movimenti di massa nel momento in cui viene superato un valore di inclinazione limite, insieme a fenomeni di soil creep. il materiale viene quindi immesso nel sistema fluviale come i n p u t p r o v e n i e n t e dal versante (al fine di simulare fenomeni come i collassi di sponda). una volta che il tasso di erosione/sedimentazione è calcolato, vengono aggiornati i valori di quota e granulometria per ogni cella del territorio modellato. uno degli aspetti più innovativi presenti in caesar è sicuramente l'utilizzo di un “time step” variabile. come visto, i modelli di automazione cellulare applicano per ogni iterazione temporale una serie di regole o equazioni ai valori delle proprietà delle celle; caesar utilizza per ogni iterazione un passo temporale che varia in funzione della massima quantità di erosione o sedimentazione assicurando che tale valore non superi mai il 10% della pendenza locale. in questo modo si prevengono eventuali instabilità computazionali che possono portare ad una non realistica evoluzione del territorio. viene definito un parametro (e r o d e l i m i t) , imposto dall'utente, che rappresenta la massima quantità di materiale eroso o sedimentato che può essere coinvolto in ogni time step. se la massima quantità di materiale eroso o depositato è superiore al valore di erodelimit allora il modello dimezza il time step e ripete il calcolo fino a che tale valore è sotto il limite. in questo modo si controllano di nuovo le eventuali instabilità computazionali, poiché non vengono mai coinvolte eccessive quantità di materiale eroso o depositato, permettendo al modello di avere lunghi time steps (fino a 1 ora) nei periodi di quiescenza (ad esempio basse portate) ma anche piccoli time steps (fino al decimo di secondo) nei periodi di alte portate o di forte attività erosiva. un aspetto importante è rappresentato anche dalla risoluzione e dalla dimensione delle celle del dem. il parametro erodelimit dipende dalla dimensione delle celle; infatti la variazione di quota delle celle comporta cambiamenti nelle pendenze locali. un aumento di quota di 0.1 m per una cella appartenente ad una griglia di dimensione 1 m determina, rispetto alle celle limitrofe inalterate, un aumento di pendenza del 10%. invece, se la dimensione della cella è di 10 m, il cambiamento è del 1%. quindi, incrementando le dimensioni delle celle, i cambiamenti tra le celle sono meno severi nell'alterazione delle pendenze. questo indica che la scelta del valore di erodelimit deve essere fatta dall'utente consapevolmente ed in funzione anche della dimensione delle celle. il problema delle risoluzione è connesso alla dura209caesar: un modello per la simulazione ... ta della simulazione: un singolo evento di piena simulato attraverso un'alta risoluzione temporale connessa ad una elevata risoluzione spaziale (numero di celle superiore a 500.000), può richiedere anche un intero giorno di elaborazione. caesar viene rilasciato con licenza gpl (il sorgente del codice è liberamente scaricabile al sito www.coulthard.org.uk) e viene sviluppato principalmente presso l'università di hull (uk) (coulthard & van de wiel, 2007). 2. alcuni esempi di applicazioni di caesar caesar, grazie alla licenza gpl di rilascio, è stato adattato anche ad altri scopi di studio. il modello possiede infatti anche una routine per permettere l'evoluzione laterale e quindi simulare l'evoluzione di un fiume meandriforme, oltre che braided (co u l t h a r d, 2006). i risultati raggiunti nelle simulazioni sono stati soddisfacenti , in quanto si è dimostrato come l'erosione laterale possa essere simulata in un modello ca (cellular automata). le sponde esterne dei meandri sono state erose in quantità maggiori in corrispondenza delle curve più strette (fig 2). per simulare la sedimentazione e la ridistribuzione dei sedimenti nel canale è stato utilizzato un algoritmo che calcola il raggio di curvatura locale del meandro. la maggiore erosione nelle sponde esterne è stata valutata proprio attraverso il valore del raggio di curvatura del meandro. benché siano sicuramente possibili miglioramenti del modello per lo studio di fiumi meandriformi, caesar sta dimostrando le sue potenzialità anche per quanto riguarda questi tipi di alvei. un ulteriore esempio di applicazione di caesar è quello in cui lo stesso modello è stato opportunamente modificato per simulare l'immissione in alveo di grandi quantità di sedimenti provenienti dal versante, allo scopo di simulare (de rosa, 2007 vedi fig. 3) gli effetti di un processo gravitativo che interferisce con l'alveo, ostruendolo parzialmente o totalmente. al fine di verificare le funzionalità del modello caesar così modificato, sono state effettuate diverse simulazioni su un tratto del fiume tagliamento (friuli venezia-giulia), di cui si aveva a disposizione un opportuno modello digitale del terreno comprendente anche l'alveo sommerso. la simulazione eseguita per il tratto di fiume studiato, ha immesso nell'alveo circa 300.000 m3 di materiale in 3 ore, mentre nel fiume transitava una portata liquida di circa 20 m3/s . la figura 3 mostra alcuni screenshots di caesar, relativi alla simulazione effettuata, in cui si nota come il modello simula l'immissione di sedimenti in alveo dal versante. la simulazione ha mostrato come si sia sviluppata una parziale occlusione d'alveo, cosa molto verosimile, considerate le dimensioni del corso d'acqua (in termini di larghezza d'alveo e di portata liquida) e dei volumi immessi. la modifica apportata ha permesso di creare un modello numerico per simulare la dinamica dell'alveo a seguito dell'immissione di materiale dai versanti. il caesar modificato, quindi, si pone come un modello utile per la stima degli effetti dovuti a immissione di materiale in alveo per frana, in sostituzione dei vari indici fino ad oggi utilizzati (casagli & ermini, 1999). 3. simulazione degli effetti di opere in alveo nel presente lavoro caesar è stato utilizzato per studiare gli effetti prodotti, a scala di tratto fluviale, a seguito della realizzazione di opere trasversali deflettori di flusso (pennelli). per motivi di opportunità, essendo già disponibili i dati relativi al dem e alle portate, la simulazione è stata effettuata sullo stesso tratto del fiume tagliamento utilizzato per lo studio delle frane in alveo mostrato in figura 3, gentilmente fornito dall'autorità di bacino dei fiumi isonzo, tagliamento, livenza, piave, brenta-bacchiglione. il dtm del tagliamento che è stato utilizzato è frutto di un rilievo laseraltimetrico, la cui “nuvola” di punti è stata interpolata con risoluzione pari a 2 metri al suolo. al fine di rendere più performante la simulazione (riducendo i tempi di calcolo necessari per la simulazione di un periodo di oltre 750 giorni) la risoluzione del dtm è stata portata a 10 metri al suolo. come già descritto nei capitoli precedenti, caesar necessita, tra i vari dati di input, della distribuzione granulometrica dei sedimenti presenti in ogni cella del territorio di cui si sta simulando l'evoluzione. caesar infatti può gestire fino a 9 granulometrie differenti per 10 layers in profondità. questo è, da un lato, un vantaggio poiché si possono avere simulazioni dove si riproducono i fenomeni delle dinamiche d'alveo in modo più realistico; dall'altro rappresenta invece una difficoltà operativa, a causa del reperimento di dati così dettagliati che risultano essere raramente disponibili. in questi casi la procedura classica adottata consiste nell'assegnare una distribuzione granulometrica uguale per tutte le celle e costante in profondità e simulare successivamente un periodo di “spin-off”. durante il periodo di spin-off si fanno transitare nel tratto fluviale in questione portate idriche compatibili con i valori reali. questa simulazione permette lo sviluppo di un dato granulometrico che, anche se fittizio, è il più possibile simile a quello presente all'interno dell'alveo. si sviluppano, infatti, i processi sedimentari tipici di un alveo, come il corazzamento del canale oppure la differenza tra la distribuzione granulometrica presente in una barra (con granulometrie che decrescono passando dalla testa alla coda dei corpi sedimentari), ecc... nel caso in esame la distribuzione granulometrica di partenza è stata desunta dai dati riportati in surian ( su r i a n, 2002) riguardanti il fiume piave, che presenta caratteristiche geomorfologiche e sedimentarie molto simili a quelle del tagliamento. ai nostri fini tale assunzione è più che sufficiente, in quanto la simulazione non è finalizzata allo studio del le variazioni granulometriche dell 'a lveo del tagliamento, quanto piuttosto a valutare l'affidabilità del modello nel prevedere gli effetti dovuti alla realizzazione di opere idrauliche. il risultato della fase di spinoff (di durata pari a 10 mesi) è mostrato in figura 6a, dove l'intensità della scala di grigio è funzione del d50 del layer superficiale; si apprezza come, al termine della fase di spin-off, i valori più alti del d50 si posizionano in corrispondenza dei canali, come è logico aspettarsi. la simulazione vera e propria è stata effettuata inserendo 5 pennelli longitudinali posti a protezione della sponda posta in sinistra idrografica e l'effetto di tali opere è stato simulato utilizzando un periodo di 750 giorni ( circa 2 anni). l'idrogramma in input, ribadendo che lo scopo del lavoro consiste nel testare il comportamento del modello in tali condizioni da un punto di vista qualitativo, non è reale ed è stato ricostruito sulla base dei valori medi (200m3/s) e di picco (1000 m3/s) riportati su surian e rinaldi (2003). in figura 4 è raffigurato il battente idrico ottenuto durante la simulazione, prima e dopo l'immissione dei 210 fig. 2 evoluzione di un tratto fluviale meandriforme (tratto da coulthard & van de wiel, 2006). in figura (a) si osserva l'evoluzione del meandro. le diverse ombreggiature corrispondono a 5 diversi stadi evolutivi. in figura (b) è riportato invece il confronto tra lo stadio iniziale (in bianco)e quello finale (in nero). meander development (from coulthard & van de wiel, 2006). (a) meander growth; the different shades correspond to five different time slices from the model. (b) initial and final channel positions. coulthard et al. 211caesar: un modello per la simulazione ... pennelli. in (a) è raffigurata la situazione originaria senza la presenza dei pennelli mentre la figura (b) mostra il battente idrico che si ottiene dopo un periodo simulato di due anni dall'immissione dei pennelli. si nota come la presenza delle opere trasversali abbia sviluppato maggiormente il canale secondario (posto grossomodo al centro dell'alveo attivo) rispetto alla situazione riportata in (a). oltre ad analizzare la nuova configurazione del battente idrico, è stato analizzato il processo erosivo deposizionale, effettuando il confronto tra il modello digitale del terreno prima e dopo la simulazione (fig. 5), tramite una semplice operazione di map algebra. l'analisi mette in evidenza una prevalenza di zone in sedimentazione (colore scure) a monte dei pennelli, mentre si manifesta una zona prevalentemente in erosione (zone chiare) al centro dell'alveo, appena oltre la fine dei pennelli. in figura 6 è riportata la distribuzione del d50 del layer superiore al termine del periodo di spin-off (a) e dopo i 750 giorni di simulazione (b). il confronto mostra come le classi granulometriche di diametro più elevato 212 fig. 4 mappa del battente idrico simulato con caesar, prima (a) e dopo (b) l'immissione nel modello delle opere di difesa spondale. i valori in legenda rappresentano il battente idrico, espresso in metri. map of waterdepth simulated by caesar before (a) and after (b) the introduction of hydraulic works. the value legend are in meters. fig. 5 mappa del pattern erosivo deposizionale ottenuto tramite un confronto tra il modello digitale del terreno prima e dopo la simulazione. in legenda i valori sono espressi in metri; i valori negativi indicano sedimentazione, i positivi erosione. map of erosion-deposition pattern comparing a digital elevation model before and after simulation. the value legend are in meters; negative values indicate deposition, positive erosion. fig. 6 d50 del tratto studiato prima (a) e dopo l'immissione dei pennelli (b). il colore grigio più chiaro rappresenta classi granulometriche più grossolane. map of d50 of reach before (a) and after (b) the presence of hydraulic works. the dark gray color represent a finer granulometic class. coulthard et al. 213 si siano spostate congruentemente con quanto evidenziato dal battente idrico e dal processo erosivo/deposizionale. al fine di studiare con maggiore chiarezza gli effetti erosivi deposizionali causati dalla presenza dei pennelli, è stato costruito un profilo di una seziona fluviale subito a monte di uno dei pennelli, come mostrato in figura 7. l'esame della sezione riportata in figura 8 consente di apprezzare con maggior dettaglio i cambiamenti morfologici prodotti dalla simulazione. sono stati individuati alcuni punti, numerati da 1 a 4 lungo la sezione , utilizzati per spiegare e comprendere bene gli effetti avuti lungo questa sezione. si nota come il canale a ridosso del versante in sinistra idrografica (punto 1 in fig. 8), cioè il canale principale precedente, sia stato colmato quasi completamente a causa dell'influenza del pennello. l'opera stessa, deviando il flusso idrico in destra idrografica, ha comportato una parziale erosione della barra nel punto 2. si nota infatti, in sezione, che la barra si assottiglia molto dopo solo due anni di attività delle opere di difesa spondale. il canale al punto 4, al contrario, non risente delle opere, essendo situato ad una distanza consistente da esse (circa 400 metri). 4. conclusioni lo scopo del lavoro è quello di testare caesar anche al di fuori del campo di applicazione per cui il modello nasce. caesar, infatti, è stato sviluppato principalmente per studiare le variazioni geomorfologiche a scala di bacino o di alveo per lunghi periodi temporali (centinaia di anni). le altre applicazioni mostrate in questa sede hanno richiesto alcune modifiche del codice sorgente. in questa sede caesar è stato utilizzato per simulare gli effetti di opere idrauliche trasversali a scala di tratto fluviale per un intervallo temporale breve (2 anni circa), mostrando sostanzialmente risultati realistici. caesar è un modello quantitativo che attualmente viene utilizzato prevalentemente a fini di ricerca. la correttezza delle simulaz ioni, invece, è stata testata essenzialmente da un punto di vista qualitativo. i risultati ottenuti, riguardanti i processi erosivi/deposizionali, il battente idrico (connesso alla configurazione dei canal i di magra) e la distribuzione del d50 all'interno dell'alveo sono congruenti con la presenza dei pennelli. fig. 7 traccia del profilo trasversale raffigurato nel grafico successivo . trasverse profile shown in next figure. fig. 8 la linea tratteggiata rappresenta il profilo finale della sezione trasversale ab riportata in figura mentre la linea continua quello iniziale. i principali cambiamenti all'interno dell'alveo, dovuti alla simulazione possono essere così sintetizzati: il pennello ha causato sedimentazione di materiale all'interno del vecchio canale principale (punto 1); nel punto 2 si vede come la barra è stata erosa a seguito dello spostamento del flusso dovuto alla presenza del pennello; nel punto 3 uno dei canali secondari è stato parzialmente eroso, mentre il canale presente nel punto 4 risente solo marginalmente della presenza delle opere trasversali. the dotted line represent the ab final profile, while the continuous line is the initial profile. the main change are in 1 where is shown a deposition. in 2 the bar has been eroded; in 3 ones of secondary channel has been partially eroded. in 4 we do not see any change. caesar: un modello per la simulazione ... nel dettaglio, la simulazione ha prodotto il colmamento quasi completo del canale a ridosso del versante in sinistra idrografica, la conseguente erosione della barra longitudinale limitrofa e una nuova configurazione dei canali di magra perfettamente coerente con la presenza dei pennelli all'interno dell'alveo. l'intervallo di tempo simulato nel presente lavoro è pari a circa due anni. è opportuno sottolineare che i tempi di calcolo necessari al modello, che dipendono dalla risoluzione del dtm e dall'intervallo di tempo che si vuole simulare, sono abbastanza lunghi. nel caso specifico sono state necessarie circa 20 ore per simulare il periodo di 750 giorni. in conclusione, è possibile affermare che caesar riproduce risultati realistici, almeno qualitativamente, anche per studiare gli effetti sulle dinamiche d'alveo dovute alla presenza di opere idrauliche. e' interessante, approfondire l'aspetto quantitativo; per far questo, è necessario reperire una consistente mole di dati riguardanti batimetrie, profili, distribuzioni granulometriche, portate liquide e solide, distribuite su un intervallo temporale sufficientemente ampio ed in alvei con caratteristiche morfologico-.sedimentarie differenti. bibliografia ca s a g l i n., er m i n i l. (1999) geomorphic analysis of landslide dam of northern appenine. transaction of the japanese geomorphological union, 20 (3), pp. 219-249. coulthard t.j., hicks d.m., van de wiel m.j. (2007) cellular modelling of river catchment and reaches: advantages, limitation and prospect . geomorphology, 90, pp. 192-207. co u l t h a r d t.j. & va n de wi e l m.j. (2006) a cellular model of river meandering. earth surface processes and landforms, 31 (1), pp. 123-132. coulthard t.j., macklin m.g. & kirkby m.j. (2002) a cellular model of holocene upland river basin and alluvial fan evolution. earth surface processes and landforms, 27, pp. 269-288. de ro s a p. (2007) un approccio modellistico per il fenomeno delle frane in alveo: una modifica al model lo caesar. giornale di geologia applicata, in stampa. hoey t. & ferguson r. (1994) numerical simulation of downstream fining by selective transport in gravel bed rivers: model development and illustration. water resources research, 3 0 (7), pp. 22512260. murray ab & paola c. (1994) a cellular model of braided rivers. nature, 371, pp. 54-57. nicholas a.p. (2005) cellular modelling in fluvial geom o r p h o l o g y. earth surface processes and landforms, 30, pp. 645-649. su r i a n n. (2002) downstream variation in grain size along an alpine river: analysis of controls and processes. geomorphology, 43 (1-2), pp. 137-149. surian n. & rinaldi m. (2003) morphological response to river engineering and management in alluvial channels in italy. geomorphology, 5 0 (4), pp. 307-326. wilcock p.r. & crowe j.c. (2003) surface-based transport model for mixed-size sediment. journal of hydraulic engineering, asce, 1 2 9 (2), pp. 120 128. 214 ms. ricevuto il 28 marzo 2008 testo definitivo ricevuto il 29 maggio 2008 ms. received: march 28, 2008 final text received: may 29, 2008 coulthard et al. imp.capaccioni& caratterizzazione idrochimica di un acquifero superficiale: il caso della circolazione idrica nei corpi di frana nella dorsale carbonatica di m. pietralata – m. paganuccio (appennino marchigiano) bruno capaccioni1, olivia nesci2, enrico maria sacchi2, daniele savelli2 & francesco troiani2 1istituto di vulcanologia e geochimica, università degli studi “carlo bo”, campus scientifico, loc. crocicchia, 61029 urbino – b.capaccioni@uniurb.it 2istituto di geologia, università degli studi “carlo bo”, campus scientifico, loc. crocicchia, 61029 urbino – d.savelli@uniurb.it riassunto: capaccioni b., nesci o., sacchi e. m., savelli d. & troiani f., caratterizzazione idrochimica di un acquifero superficiale: il caso della circolazione idrica nei corpi di frana nella dorsale carbonatica di m. pietralata m. paganuccio (appennino marchigiano). (it issn 0394-3356, 2004). nella presente nota sono descritti i risultati di una ricerca sulle caratteristiche idrochimiche delle acque di sorgente emergenti dai corpi di frana che interessano i fianchi della dorsale anticlinalica di m. pietralata – m. paganuccio. il collasso gravitativo di gran parte dei fianchi della dorsale, legato principalmente all’assetto morfostrutturale e litostratigrafico dell’area, coinvolge generalmente il substrato e ha prodotto vasti e spessi accumuli di frana, variamente dislocati e disarticolati. le masse franate, avendo sviluppato una elevata permeabilità secondaria, hanno costituito acquiferi propri e sensibilmente condizionato la circolazione idrica sotterranea più superficiale. ciò ha generato numerosi punti di scaturigine distribuiti sia alla base del rilievo, ai margini dei principali corpi di frana, sia all’interno dei corpi stessi. in certi casi, invece, gli accumuli di frana probabilmente ricoprono sorgenti legate a circuiti più profondi, all’interno delle rocce del substrato. i risultati delle analisi chimiche effettuate sulle acque di sorgente nelle campagne di monitoraggio del 1984 e del 2004, oltre a caratterizzare facies idrochimiche sub-superficiali direttamente legate ai corpi di frana, sottolineano proprio una loro probabile miscelazione con acque di provenienza più profonda.. abstract: capaccioni b., nesci o., sacchi e. m., savelli d. & troiani f., the hydrochemical feature of surficial groundwaters: the groundwaters from landslide deposits of the carbonatic ride of mts. pietralata-paganuccio (marche appennines. (it issn 0394-3356, 2004). geological-geomorphological and hydrochemical studies have been carried out throughout the anticline ridge of pietralata-paganuccio mts. (northern umbria-marche apennines, central italy) in order to find a possible correlation between the large landslides almost affecting the entire mountain flanks and spring-water characteristics. the study area embraces the northernmost sector of a much longer calcareous anticline ridge extending all along the marche region. the furlo gorge, a narrow transverse canyon deeply cut by the candigliano river (metauro river basin), breaches the anticline ridge separating the two mountains from each other. this sector of the ridge, although rather simple as for its morphostructure, is indeed one of the most important examples of such landforms so characteristic of the umbria-marche apennines. pietralata and paganuccio mts. consist of the mostly calcareous and marly-calcareous mesocenozoic units of the umbria-marche succession. the jurassic-cretaceous terrains, ranging from the calcare massiccio fm. and the scaglia bianca fm., crop out in the furlo gorge area only, deeply cut in its turn at the core of the anticline. the flanks and the crest of the anticline ridge, on the contrary, are made up of createceous-oligocene terrains, namely scaglia rossa-scaglia cinerea and bisciaro fms. pietralata and paganuccio mts. are an explicatory example of an exhumed anticline, where the geological structure is distinctly replicated by the relief topography. indeed, the ridge morphology almost perfectly displays both the rounded geometry of the anticline and its northwestern and southeastern plunge-out areas. furthermore, characteristic flat top-surfaces markedly reflect the sub-horizontal/gently-dipping bedding of the hinge zone, while the mountain sides slope at angles approximating the downslope-dipping layering values. although the peculiar morphostructural arrangement of the ridge has been shaped by different processes, the role of large, deep-seated mass movements is once more today among the most effective ones. landslides, affecting both sides of the ridge for the most part, find their key predisposing factors in the dip-slope layering attitude on the two sides of the anticline ridge, as well as in the occurrence of weak marly horizons (e.g. marne a fucoidi fm., marly members of scaglia rossa fm., etc.),embedded among calcareous units in different stratigraphic positions. the occurrence of an intense local rock-fracturing is an effective additional predisposing factor. as a result, the most part of the anticline ridge flanks have been extensively denudated by more or less shallow landsliding, able to highlight both lithologic contrasts of the jurassic-miocene “multilayer” and structural features, such as fault-zones and bended bedding surfaces. the gravitational sagging and collapse of the anticline flanks encompass several, different field evidence. as a rule, the landslide head areas display tension cracks and more or less distinct trenches, scarps and counterslopes; the slid mass becoming more and more disrupted and chaotic downslope, where an over-100m thickness is often reached and stressed by deep gully dissection of the landslide mass. indeed, the substantial permeability acquired by progressive fracturing of the sliding rock bodies allows for a great number of frequently perennial aquifers and springs to occur within the slid-bodies and/or at the toe of the major landslides. on the contrary, in some places, the landslide materials have probably blanketed some springs related to relatively deep bedrock aquifers. hydrochemical data show that the characteristics of the majority of the analysed waters set in the field of ca2+ hco3 compositions, with two different trends, namely “a”, trending towards na+ clcompositions, and “b”, trending towards ca2+ so4 2compositions. a possible reason of these two trends is the mixing of superficial water circulating inside the landslide masses with waters flowing out from deeper bedrock-aquifers. water samples from the pietralata mt. area, according to the most part of waters from carbonatic rocks of the marche region, display contents in ca2+, mg2+ and hco3 which are mostly due to magnesian-calcite solution or, alternatively, to a mixing of calcite and dolomite (this latter, especially for waters from relatively deep aquifers). as regards water saturation in calcite at different pco2 conditions, the analysed samples display a range of values approximating those typical for soils (0.15 bar). being such values much higher than those already reported for carbonate aquifers of nerone mt. (0.0003 – 0.003 bar), a near-surface water circulation can be alleged. in this respect, a similar assumption can be drawn from both the relatively low discharges of the studied springs, and from the recurring traces of no3 concentration. as regards this latter, in particular, its relatively high concentration in both 1984 and 2004 samplings is likely to be related to both biologic activity and humification (nitrification) on the surface of the slid-masses, although a less important amount of no3 from fertilizers cannot be ruled out. moreover, a low ca2+ so4 2composition of the samples at issue can be related to the mixing of relatively deep waters from bedrock aquifers whose springs are blanketed by thick landslide accumulations. finally, the observed trend “a”, towards na+ clcompositions, can be ascribed to cyclic salts coming from near marine areas. parole chiave: corpi di frana, idrochimica, dorsali carbonatiche, monti paganuccio e pietralata, italia. keywords: landslide bodies, hydrochemistry, carbonate ridges, paganuccio-pietralata mts., central italy. il quaternario italian journal of quaternary sciences 17(2/2), 2004, 585-595 586 b. capaccioni et al. 1. introduzione la dorsale carbonatica del m. paganuccio-m. pietralata (fig. 1) presenta numerose sorgenti, distribuite sia sulle aree più elevate che lungo le sue fasce perimetrali e alla base dei versanti. l’ubicazione delle principali sorgenti perenni, monitorate nel 2004, è riportata nelle figure 2 e 3. i punti di scaturigine di alcune di esse si trovano su roccia in posto (sorgenti n. 1, 4, 5 8 in figura 3), soprattutto in prossimità e/o in corrispondenza di apprezzabili contrasti litologici o di dislocazioni tettoniche. la maggior parte delle sorgenti è invece ubicata sul margine di potenti coltri detritiche e/o su rocce interessate da reti di fratture secondarie più o meno persistenti ed evidenti in superficie. il numero relativamente elevato di sorgenti associate a masse detritiche e/o rocce fratturate si collega direttamente al collasso gravitativo quasi generalizzato dei fianchi della dorsale, determinato dall’assetto litostratigrafico e morfo-strutturale della stessa (cf. burattini et al., 1989; diligenti et al., 2004). i movimenti di versante, vasti e spesso profondi, hanno infatti dato origine sia a un’intensa fratturazione secondaria delle rocce, sia alla formazione di potenti coltri costituite da materiale roccioso variamente mobilizzato e disgregato (nesci & savelli, 1986). proprio questa situazione ha determinato lo sviluppo di un certo numero di acquiferi relativamente superficiali localizzati all’interno o al margine dei corpi interessati da collasso gravitativo e sostenuti da orizzonti acquicludi e acquitardi in corrispondenza dei livelli di scivolamento. oggetto della presente nota è fornire alcune indicazioni di carattere geologico-geomorfologico utili all’inquadramento e caratterizzazione delle emergenze idriche e allo stesso tempo di descrivere tali emergenze da un punto di vista idrochimico, nonché di individuare eventuali possibili interazioni tra gli acquiferi superficiali e quelli più profondi. 2. assetto geologico e geomorfologico i monti pietralata e paganuccio (qui detti monti del furlo, seguendo una denominazione locale), separati fra loro dalla profonda gola diaclinale del furlo (figg. 1-3), costituiscono un esempio particolarmente esplicativo, sebbene piuttosto semplice dal punto di vista morfostrutturale, delle dorsali anticlinaliche carbonatiche che caratterizzano l’appennino umbromarchigiano (cf. diligenti et al., 2004). i due rilievi anzidetti costituiscono la terminazione settentrionale di una più ampia morfostruttura ad assetto anticlinorico (dorsale marchigiana di centamore et al., 1972) che partendo dal massiccio dei monti sibillini attraversa quasi l’intera regione marchigiana, estendendosi verso nw fino al bacino del fiume metauro e andando così a costituire uno degli elementi morfostrutturali più rilevanti di questo settore dell’appennino (bisci & dramis, 1991 cum bibl.). i rilievi del monte paganuccio (a se, 976 m) e del monte pietralata (a nw, 888 m), in particolare, corrispondono a una accentuata culminazione della dorsale che, in direzione assiale, fig. 1 ubicazione dell’area e assetto geologico regionale. 1 = termini calcarei e calcareo-marnosi meso-cenozoici delle dorsali carbonatiche; 2 = termini marnoso-calcarei, evaporitici e silicoclastici cenozoici; 3 = coltre della val marecchia; 4 = termini terrigeni pliopleistocenici; 5 = depositi alluvionali e costieri del pleistocene medio-olocene; m = dorsale marchigiana; um = dorsale umbromarchigiana; a = dorsale minore di acqualagna; c = dorsale minore dei monti della cesana. location of the study area and regional geologic setting. 1 = meso-cenozoic calcareous and marly-calcareous formations of the carbonatic ridges; 2 = cenozoic marly-calcareous, evaporitic and siliciclastic formations; 3 = val marecchia allochthon; 4 = plio-pleistocene terrigenous formations; 5 = middle pleistocene-holocene fluvial and coastal deposits; m = marche ridge; um = umbria-marche ridge; a = acqualagna minor ridge; c = monti della cesana minor ridge. digrada rapidamente sia verso nw (terminando nella valle del metauro all’altezza di fermignano, fig. 1), sia verso se (descrivendo l’ampia depressione topografica attraversata dalla valle del fiume cesano, fig. 1). verso nord-est la dorsale si collega con una stretta depressione sinclinalica (sinclinale del metauro) che la separa da una dorsale anticlinalica minore più esterna (monti della cesana), mentre verso le aree interne (sud-ovest), si collega all’ampio sinclinorio corrispondente col cosiddetto bacino marchigiano interno (centamore et al., 1972). dal punto di vista strutturale la dorsale coincide con una piega ne-vergente, caratterizzata da una geometria a scatola, con cerniera piatta e fianchi ripidi (deiana & pialli, 1994 cum bibl.) e asse localmente con direzione n120°. l’immersione della linea di cerniera, rispettivamente verso nw a monte pietralata e verso se a monte paganuccio, evidenzia come la culminazione topografica della dorsale, espressa dai monti del furlo, corrisponda a una culminazione strutturale dell’anticlinale. inoltre, singolarmente, è proprio in corrispondenza della culminazione stessa (figg. 2 e 3) che il fiume candigliano oltrepassa la dorsale attraverso il profondo canyon della gola del furlo (cf. mayer et al., 2003). a differenza di quanto si osserva in molte anticli587caratterizzazione idrochimica di un acquifero ... nali umbro-marchigiane, il fianco esterno della struttura non presenta superfici di sovrascorrimento riconoscibili in affioramento. il versante che collega la sommità della dorsale con il fondovalle (qui coincidente con la zona assiale della sinclinale del metauro) è invece interessato da un esteso retroscorrimento (capuano & giampieri, 1989). la strutturazione della dorsale è iniziata nel tortoniano, a seguito di una tettonica a pieghe e thrust con vergenza orientale (centamore et al., 2002 cum bibl. ) . tra la f ine del pleistocene inferiore e i l pleistocene medio, l’attività plicativa e dei thrust si è esaurita, lasciando posto a un sollevamento generalizzato accompagnato da movimenti differenziali e da una deformazione post-thrusting cui corrispondono faglie associabili a una estensione orientata in senso wswene (di bucci et al., 2003). i terreni che costituiscono i monti del furlo appartengono (cf. cecca et al., 2001) ai termini meso-cenozoici della successione umbro-marchigiana (fig. 3) compresi fra le formazioni del calcare massiccio (lias inferiore) e del bisciaro (miocene inferiore). il nucleo della dorsale anticlinalica è costituito dal calcare massiccio (fig. 3), la formazione più antica affiorante nell’area, ben visibile sia sulle pareti della gola del furlo (con spessori superiori a 500 m) che nell’adiacente fig. 2 dtm dei fianchi sud-occidentale (a) e nord-orientale (b) dei monti del furlo e ubicazione delle sorgenti perenni monitorate nel 2004. si notino alla base dei versanti, in a, la serie dei flatirons e, in b, la fitta rete di solchi di erosione. per una discussione più approfondita si veda il testo. esagerazione verticale 1:2. dtm of south-western (a) and north-eastern (b) flanks of monti del furlo and location of the perennial springs monitored in 2004. please note at the ridge foot-slope, in a the series of flatirons, and in b the closely-spaced parallel gullies. see the text for a more detaild discussion. vertical exaggeration 1:2. 588 forra del buzzo e rappresentata da calcari dolomitici in strati mal definiti, da spessi a molto spessi, deposti in ambiente di piattaforma carbonatica. i termini del giurassico inferiore e medio compresi fra il calcare massiccio e la base della maiolica sono rappresentati da litofacies prevalentemente carbonatiche, spesso nodulari, con rapporti geometrici complessi e notevole variabilità laterale (cf. cecca et al., 2001 cum bibl.) che esprimono un ambiente di deposizione di scarpata/alto strutturale. la maiolica (giurassico superiore-cretacico inferiore), di spessore variabile da poco più di 100 m a circa 300 m, costituita da calcari micritici bianchi ben stratificati con selce grigio-nerastra in liste e noduli, affiora tutt’attorno al nucleo dell’anticlinale inciso dalla gola del furlo e dalla forra de il buzzo (fig. 3). le sovrastanti marne a fucoidi (cretacico medio, spessore di circa 80 m), rappresentate da argille e marne varicolori passanti verso l’alto a calcari marnosi da biancoverdastri a bianco rosati con liste e noduli di selce varicolore, separano la maiolica dai termini del gruppo delle b. capaccioni et al. fig. 3 schema geologico-geomorfologico dei monti del furlo e ubicazione delle sorgenti perenni monitorate nel 2004. 1 = calcare massiccio-corniola (triassico superiore-giurassico inferiore); 2 = rosso ammonitico (giurassico inferiore); 3 = bugarone-maiolica (giurassico medio-cretaceo medio); 4 = marne a fucoidi (cretaceo medio); 5 = scaglia rossa-scaglia cinerea (cretaceo superioreoligocene); 6 = bisciaro (miocene inferiore); 7 = corpo di frana (pleistocene superiore-olocene); 8 = detrito caotico di versante (pleistocene superioreolocene); 9 = alluvioni in parte terrazzate (olocene); 10 = alluvioni terrazzate (pleistocene superiore); 11 = alluvioni terrazzate (pleistocene medio-finale); 12 = alluvioni terrazzate (pleistocene medio). geologic-geomorphologic sketch map of monti del furlo and location of the spring monitored in 2004. 1 = calcare massiccio-corniola fms. (upper triassic-lower jurassic); 2 = rosso ammonitico fm. (lower jurassic); 3 = bugarone-maiolica fms. (middle jurassic-middle cretaceous); 4 = marne a fucoidi fm. (middle cretaceous); 5=scaglia rossa-scaglia cinerea fms. (upper cretaceous-oligocene); 6 = bisciaro fm. (lower miocene); 7 = landslide (upper pleistocene-holocene); 8 = slope-waste deposits (upper pleistocene-holocene); 9 = modern flood plain deposits and holocene alluvium (holocene); 10 = terrace alluvium (upper pleistocene); 11 = terrace alluvium (late-middle pleistocene); 12 = terrace alluvium (middle pleistocene). 589 scaglie (formazioni della scaglia bianca, scaglia rossa, scaglia variegata e scaglia cinerea). questi ultimi, riferibili all’intervallo cretacico superiore-oligocene, con uno spessore complessivo di quasi 600 m, ricoprono gli interi fianchi della dorsale anticlinalica (fig. 3), e sono caratterizzate da litofacies calceree e calcareo-marnose a luoghi contenenti liste e noduli di selce da nerastra a rosata. data la posizione di questi terreni sui fianchi della dorsale, la differente competenza litologica dei diversi intervalli e, soprattutto, la presenza di spessi orizzonti marnosi intercalati a calcari/calcari marnosi ben stratificati, costituiscono elementi di importanza fondamentale nel predisporre la struttura ai collassi gravitativi oggetto della presente nota. in tale ambito, assumono un significato molto rilevante i caratteri litostratigrafici della scaglia rossa che, in accordo con la suddivisione di wezel (1979) risulta localmente costituita (dal basso verso l’alto) da calcari rosati con selce (lower cherty mbr.), calcari rossi senza selce (calcarenite mbr.), un orizzonte marnoso (marly mbr.), calcari marnosi rossi senza selce (marls and limestones mbr.), calcari rosati con selce (upper cherty mbr.). in particolare, alcuni livelli marnosi paleocenici, con spessori compresi fra circa 3 e 10 m, intercalati nella porzione inferiore dei calcari marnosi rossi senza selce, giocano un ruolo determinante nella predisposizione al dissesto dei due fianchi della dorsale anticlinalica. altrettanto importanti sono i numerosi e raffittiti interstrati marnosi di spessore decimetrico che caratterizzano sia i calcari rosati con selce della parte superiore della formazione che la base della sovrastante scaglia variegata. la formazione del bisciaro (miocene inferiore, circa 70 m di spessore), costituita da calcari siliceomarnosi e marne di colore grigio-verdastro in strati variabili da pochi centimetri a 10∏20 cm, chiude la locale successione (fig. 3) e va a costituire l’ossatura di una serie di rilievi omoclinali (flatirons) distribuiti lungo l’intero fianco orientale dell’anticlinale (fig. 2). l’assetto geomorfologico dell’area al di fuori della gola del furlo ricalca piuttosto fedelmente la struttura anticlinalica del substrato. i due settori principali della dorsale, rappresentati da monte pietralata e monte paganuccio (figg. 2 e 3), evidenziano efficacemente sia la geometria arrotondata della struttura anticlinalica che le immersioni assiali verso l’area periclinalica (a nordovest) e verso una accentuata depressione assiale (a sud-est). i fianchi della dorsale sono inoltre bordati da dorsali omoclinali segmentate in caratteristici flatirons (fig. 2). inoltre, in corrispondenza della stratificazione sub-orizzontale o debolmente inclinata della zona di cerniera si sviluppano caratteristici piani sommitali, mentre i versanti, a franapoggio, presentano angoli di pendio che approssimano l’inclinazione degli strati o sono leggermente maggiori. la morfostruttura ha acquisito la sua attuale conformazione grazie all’intervento di processi diversi, dalla degradazione ai movimenti di massa, al dilavamento, a fenomeni crionivali. a prescindere dal tipo di processo, l’erosione selettiva ha quasi ovunque accentuato sia i caratteristici contrasti litologici nei termini giurassico-miocenici della locale successione, sia le geometrie delle superfici di strato e le zone di faglia. inoltre, dato che degradazione ed erosione sono stati molto più efficaci nel corso degli episodi freddi pleistocenici, molte delle forme strutturali che oggi caratterizzano i monti del furlo, sono quasi completamente ereditate da fasi morfogenetiche fredde del passato (nesci & savelli 1986; diligenti et al., 2004). fra i meccanismi morfoevolutivi più recenti un’importanza fondamentale è rivestita da grandi frane per scivolamento che si osservano lungo i versanti a franapoggio che caratterizzano i fianchi della dorsale carbonatica (fig. 3). queste, come poco sopra accennato, trovano il fattore predisponente sia nella condizione giaciturale degli strati sui fianchi della struttura, sia nella presenza a vari livelli di intervalli litologicamente deboli, come le marne a fucoidi o gli intervalli marnosi all’interno della scaglia rossa poc’anzi menzionati. altro importante fattore che predispone al collasso di interi versanti e al progressivo “sgusciamento” della struttura, è la presenza di fitte reti di fratture che interessano le rocce del substrato con direzioni sia sub-parallele che trasversali all’asse dell’anticlinale. il collasso gravitativo dei versanti si manifesta in svariati modi, dalle semplici fratture di tensione e piccole trincee che, specie nelle zone sommitali, esprimono un blando scorrimento superficiale degli strati, ai potenti ammassi di detrito caotico che ricoprono spesso interi versanti. per tutta l’estensione dei versanti (cf. figg. 2, 4, 5) si possono osservare vistose gradonatore e terrazzamenti a sviluppo ortogonale alla linea di massima pendenza, nicchie di distacco, pacchi di strati ruotati o completamente scompaginati. la maggior parte dei fenomeni gravitativi dell’area coinvolge il substrato roccioso, costituito soprattutto dalle formazioni appartenenti al gruppo delle scaglie. molte delle maggiori frane (come p. es. quella di ca i fabbri, figg. 2 e 3, cf. diligenti et al., 2004) hanno origine dai piani sommitali, in corrispondenza della cresta della struttura anticlinalica (figg. 2 e 3). in alcuni casi (p. es. ca i fabbri) sono presenti accentuate scarpate di frana, mentre in altri casi il movimento si sviluppa con gradualità, senza che la zona di coronamento mostri una vera e propria scarpata principale. una caratteristica comune a tutti i maggiori corpi di frana è una evoluzione retrogressiva, con presenza di masse rocciose roto-traslate poco scompaginate e morfologie di frana molto fresche nella parte alta e disarticolazione dei materiali via via crescente verso il piede dei versanti. nella parte medio-inferiore dei versanti, in particolare, gli accumuli sono rappresentati da potenti ammassi detritici (fino a oltre 100 m di spessore) ad assetto caotico (cf. fig. 9 in nesci & savelli, 1986). la scarsa coesione di queste masse, inoltre, fa sì che su di esse si imposti tutta una serie di movimenti di massa superficiali e che esse vengano attivamente smantellate dalle acque superficiali, con produzione di profondi solchi d’erosione cui si collegano coni detritici e detritico-alluvionali (figg. 2-5). i principali accumuli di frana e/o i corpi rocciosi traslati e disarticolati anche in modo molto blando, sviluppando una significativa permeabilità secondaria, sono associati ad acquiferi e sorgenti perenni (figg. 2 e 3) o a deflusso saltuario emergenti sia alla base del rilievo che a quote più elevate. in certi casi, gli accumuli di frana sembrano costituire “mezzi filtranti” in grado di rimescolare le acque “di frana” superficiali con acque di provenienza relativamente più profonda caratterizzazione idrochimica di un acquifero ... 590 b. capaccioni et al. fig. 4 veduta del versante nord-orientale di m. paganuccio. in evidenza la morfologia di frana sull’intero versante e le profonde incisioni al piede di grandi accumuli di frana ormai stabilizzati. the north-eastern flank of monte paganuccio. please note the landslide morphology on the whole hillslope and, in the lower sector of the slope, some deep gullies affecting inactive chaotic landslide deposits. fig 5 morfologia di frana sul versante sud-occidentale di m. paganuccio. si notino al piede del versante le forme calanchive impostate su materiali di frana caoticizzati. landslide morphology on the south-western flank of monte paganuccio. accelerate erosion emphasized by deep gullying is actively removing the down-slope part of the landslide deposits. 3. caratterizzazione idrochimica delle acque sorgive i principali accumuli di frana e/o i corpi rocciosi traslati e disarticolati anche in modo molto blando, sviluppando una significativa permeabilità secondaria, sono sede di acquiferi e sorgenti perenni o a deflusso saltuario emergenti in generale alla base del rilievo. dal diagramma quadrato di langelier-ludwig (1942) (fig. 6) si evidenzia come la totalità delle acque campionate si colloca nel campo delle bicarbonato calciche. dalle analisi del 1984 (noschese, 1984) risultavano due tendenze distinte, una verso composizioni clorurato sodiche (trend “a”), con un campione (quello a più alta salinità) con caratterizzazione clorurato sodica, e una verso composizioni solfato calciche (trend “b”). i campioni prelevati nel 2004, ad eccezione di uno che segue il trend “a”, si concentrano all’origine dei due trend nel campo caratteristico delle acque bicarbonato calciche. il diagramma di saturazione della calcite (fig. 7) evidenzia una distribuzione dei campioni tra la curva di saturazione della calcite alla pressione di co2 dei gas del suolo pari a 0.15 bar e quella dell’aria pari a 0.003 bar. la distribuzione dei campioni mostra una netta dipendenza dalla dissoluzione di calciti magnesiache, mentre si nota come i contenuti di hco3 del 2004 rispetto a quelli del 1984 abbiano subito uno slittamento verso valori più prossimi alla curva di saturazione per una pco2 tipica dei gas del suolo. a titolo di comparazione dei dati sono stati inserite nel grafico le aree composizionali tipiche degli acquiferi profondi del massiccio carbonatico di monte nerone (capaccioni et al, 2001) e le quelle di acquiferi superficiali in corpi di frana nell’alta valle del torrente apsa nei pressi di urbino (sambuchi, 2004). risulta evidente come i campioni si collochino in un campo di pco2 intermedio tra quello tipico degli acquiferi in equilibrio con i valori tipici di un suolo maturo e quello caratteristico degli acquiferi profondi. il diagramma di correlazione tra sodio e cloruri 591caratterizzazione idrochimica di un acquifero ... fig. 6 diagramma classificavo di langelier-ludwig delle acque dei monti del furlo. circoletti = campioni prelevati nel 1984 sul monte pietralata. quadrati=campioni prelevati nel 2004 sul monte pietralata. triangoli=campioni prelevati nel 2004 sul monte paganuccio. langelier-ludwig’s classification diagram of the monti del furlo spring water. open circles=samples from monte pietralata, year 1984. open squares= samples from monte pietralata collected on 2004. open triangles=samples from monte paganuccio, year 2004. (fig. 8) evidenzia che le acque dei campioni prelevati tendono ad allinearsi in prossimità della retta di rapporto di equivalenza sodio/cloruri 1:1, rapporto che si ottiene quando i due ioni derivano dalla dissoluzione di cloruro di sodio. dal grafico ca2+ / so4 2(fig. 9) si nota come la distribuzione della maggior parte dei campioni prelevati nel 1984 e nel 2004 non mostrano correlazioni significative tra le due variabili, con rapporti tra i due elementi decisamente superiore all’unità, indicando quindi una netta e costante dominanza della componente calcica, mentre le acque campionate nel 1984 del trend “b” mostrano una netta correlazione positiva parallela alla retta di equivalenza calcio/solfati. in base ai dati idrochimici raccolti (tab. 1) si può affermare che le acque sotterranee pur appartenendo alla categoria delle bicarbonato calciche mostrano una tendenza verso composizioni clorurate sodiche. in considerazione dell’assenza di depositi noti di nacl nelle formazioni che costituiscono gli acquiferi, tale caratteristica potrebbe essere imputabile alla dissoluzione nelle stesse di cloruro di sodio probabilmente di origine “ciclica”, ovverosia da deposizione umida o secca di microcristalli di nacl originatesi da spray marino e trasportati in sospensione nell’entroterra. in particolare, a risentire dei sali ciclici sono per lo più le sorgenti poste alle quote più elevate. la tendenza verso composizioni solfato calciche, evidente sui campioni del 1984 (trend “b”, fig. 6), potrebbe essere messa in relazione a miscelazioni con acque di circuiti idrogeologici più profondi, la cui caratterizzazione solfato calcica potrebbe derivare da processi ossidativi su solfuri dispersi, la cui presenza è documentata sulle formazioni della scaglia bianca, marne a fucoidi e maiolica (cf. coccioni at al., 1994; 1987.) l’assenza di evidenze di processi di miscelazione nei campioni prelevati nel 2004 potrebbe derivare da un generale abbassamento dei livelli piezometrici durante l’ultimo ventennio e/o dalla localizzazione delle loro emergenze a quote superiori ai 300 m slm. i campioni dell’area in esame, come la maggior parte dei campioni di acque provenienti dagli acquiferi carbonatici della regione, mostrano contenuti in ca2 +, mg2 + e hco3 riferibili a prevalente dissoluzione di calciti magnesiache. le acque in esame mostrano valori di pressione di co2 prossimi a quelli tipici dei suoli (0.15 bar), ciò indica verosimilmente una circolazione idrica relativamente superficiale, come del resto testimoniata dai bassi valori di portata misurati. inoltre si è notato come le sorgenti alle pendici dei massicci presentino un contenuto di co2 minore rispetto le sorgenti poste alle quote più elevate. nel grafico in esame la traslazione dei campioni rispetto le due campagne di monitoraggio è dovuta verosimilmente al fatto che nel 1984 i campioni sono stati prelevati nel mese di settembre, periodo siccitoso, mentre nel 2004 i campioni prelevati nel mese di febbraio hanno risentito della miscelazione con acque di circolazione più superficiali, le quali si sono arricchite di co2 come conseguenza della circolazione negli orizzonti più superficiali del suolo. inoltre nel mese di febbraio gli apporti di acque superficiali hanno fatto si che la componente bicarbonato calcica prevalga in modo 592 b. capaccioni et al. fig. 7 diagramma di saturazione della calcite. simboli come in fig. 6. calcite saturation diagram. symbols as in fig. 6. decisivo sulle altre due. un’ulteriore conferma della superficialità degli acquiferi deriva dalle concentrazioni di nitrati, relativamente alte, riscontrate nelle campagne di monitoraggio del 1984 e 2004, la cui origine è imputabile all'attività biologica negli orizzonti superficiali humificati (nitrificazione). a tutt’oggi, i valori di tali composti sono rimasti pressoché inalterati, unica eccezione è il campione sito in località ca’bernardi (sorgente n° 10) in cui i valori si aggirano attorno ai 52 mg/l; tale anomalia potrebbe essere connessa al fatto che le acque sotterranee circolano al di sotto di aree adibite ad uso agricolo. 593caratterizzazione idrochimica di un acquifero ... fig. 8 diagramma di correlazione cl-/na+. simboli come in fig. 6. cl-/na+ correlation diagram. symbols as in fig. 6. fig. 9 diagramma di correlazione ca2+/so4 2-. la linea tratteggiata indica i campioni corrispondenti al trend “b” di fig. 1. simboli come in fig. 6. ca2+/so4 2correlation diagram. dashed line points out samples from trend “b” on fig. 1. symbols as in fig. 6. 594 b. capaccioni et al. tab.1 parametri chimici determinati. i campioni del 1984 privi di numerazione sono quelli non ricampionati e quindi non comparati con quelli del 2004. chemical parameters. the unnumbered samples, collected only in 1984, are not compared with 2004 samples. analisi chimiche dei campioni prelevati nel 1984 sorgente nitrati solfati cloruri alcalinità potassio sodio cloro magnesio n° ppm ppm ppm ppm ppm ppm ppm ppm 0,8 4,5 14 171 0,7 5,0 58 2,0 1,5 3,0 21 195 1,6 10,5 64 2,0 2,0 8,0 13 108 2,0 14,0 24 2,4 1,1 9,0 22 256 1,2 9,5 82 6,0 1,2 2,0 17 180 0,6 6,0 58 4,0 8 2,0 4,5 20 210 1,3 11,0 66 4,0 2,0 9,0 22 201 1,1 11,0 63 8,0 4,2 8,0 26 201 0,7 10,0 62 8,0 3,0 3,0 22 250 2,3 11,0 81 3,0 16,0 36,0 18 210 1,4 11,8 65 14,0 1,5 39,0 29 271 3,6 28,0 77 11,0 8,0 20,0 26 223 2,0 13,0 70 11,0 1,7 30,0 40 220 1,5 18,0 67 15,0 1,2 19,0 22 213 1,8 12,0 65 9,0 9 0,9 3,0 18 170 0,9 8,0 49 7,0 1,2 10,0 20 165 0,8 6,6 54 1,0 0,9 5,0 19 213 0,5 8,1 66 6,0 1,2 2,0 16 201 0,6 5,3 70 1,0 1,9 5,0 25 314 2,2 17,0 83 13,0 1,5 24,0 14 296 0,9 7,5 92 10,0 1,2 101,0 23 268 0,9 12,5 100 5,0 1,2 13,0 29 232 2,0 14,5 73 7,0 1,0 95,0 19 177 1,4 101,0 50 30,0 4 1,3 58,0 19 168 0,5 8,5 53 18,0 0,4 3,0 15 165 9,9 6,0 50 4,0 7 1,2 6,0 18 198 0,6 7,2 65 4,0 0,8 10,0 17 134 0,6 7,2 47 2,0 0,8 38,0 23 256 0,7 10,9 81 14,0 1,2 11,0 13 195 0,5 5,5 65 4,0 1 1,5 5,0 24 170 9,8 9,9 60 2,0 1,0 55,0 22 223 0,9 10,0 70 18,0 1,1 12,0 20 241 0,7 8,0 72 10,0 1,5 80,0 21 201 1,2 9,0 62 25,0 1,4 23,0 27 210 1,5 11,5 67 10,0 1,4 12,0 19 204 0,7 7,0 65 7,0 1,4 95,0 21 183 2,6 7,5 94 6,0 5,0 42,0 197 244 4,8 110,0 76 22,0 analisi chimiche dei campioni prelevati nel 2004 sorgente nitrati solfati cloruri alcalinità potassio sodio cloro magnesio n° ppm ppm ppm ppm ppm ppm ppm ppm 1 3,1 14,6 38,0 213,5 0.01 27,5 68,8 2,8 2 0,3 9,0 26,8 298,9 0,48 16,5 97 2,3 3 1,3 8,0 11,6 250,1 0,74 7,4 91 1,7 4 0,4 9,4 13,6 262,3 0,48 13,6 88,8 2,5 5 1,2 12,0 19,4 231,8 1,68 12,3 73 1,8 6 1,6 6,4 15,2 237,9 0,62 10,6 76,5 2 7 0,2 7,2 23,8 231,8 0.01 8,4 74 1,8 8 0,3 8,0 11,8 256,2 0,64 13,9 79 2 9 1,3 5,8 19,0 183,0 0.01 7,6 55 3 10 52 7,6 20,2 213,5 0.01 8,8 70,3 1,8 4. conclusioni sono state visionate numerose sorgenti presenti sulla dorsale carbonatica di m. pietralata-m. paganuccio, molte delle quali ubicate in corrispondenza dei principali accumuli di frana, allo scopo di fornire l’inquadramento geologico-geomorfologico delle stesse e fornire una caratterizzazione idrochimica. le principali conclusioni sono riassumibili come segue: • le frane alle quali molte sorgenti sono collegate sono dei profondi scorrimenti di carattere roto-traslativo legate sia alla giacitura a franapoggio che alla presenza di livelli litologicamente “deboli” all’interno della locale successione. le frane sono caratterizzate da settori attivi, o comunque di più recente attivazione soprattutto verso le zone di coronamento del corpo principale. verso la base i corpi di frana sono invece costituiti da potenti accumuli detritici ad assetto caotico. la maggior parte delle sorgenti è ubicata ai piedi o ai margini dei corpi di frana di cui sopra. altre sorgenti, invece, scaturiscono direttamente da rocce del substrato. • le acque medio minerali dei detriti si caratterizzano prevalentemente in bicarbonato calciche con elevati valori di pco2 all’equilibrio e significativa presenza di nitrati. i dati idrochimici del 1984 mostrano trend di miscelazioni riferibili a risalite di acque da circuiti idrogeologici più profondi, mentre la modesta tendenza verso composizioni clorurato sodiche potrebbe associarsi alle deposizioni umide da sali ciclici. bibliografia bisci c. & dramis f. (1991) la geomorfologia delle marche. in: minetti a., nanni t., perilli f., polonara l. & principi m. (eds.), l’ambiente fisico delle marche. geologia, geomorfologia, idrogeologia. regione marche, giunta regionale, assessorato urbanistica-ambiente, pp. 81-113. burattini f., nesci o. & savell i d. (1989) late quaternary slope movements in the north marche apennines. examples from the lower candigliano and middle metauro river basins. acta naturalia de "l'ateneo parmense", 25 (1/4), pp. 61-70. capaccioni b., didero m., paletta c., salvatori p. (2001) hydrogeochemistry of groundwaters from carbonate formation with basal gypsiferous layers: an example from the mt catria-mt nerone ridge (northern appennines, italy). j. hydrol., 253, pp. 14-26. capuano n. & giampieri a. (1989) appennino marchigiano settentrionale: il retroscorrimento dei monti della cesana. boll. soc. geol. it., 108, pp. 59-68. cecca f., catenacci v., conte g., cresta s., d'andrea m., graziano r., menichetti m., molinari v., pampaloni m. l., pantaloni m., pichezzi r. m., rossi m., (2001) risultati preliminari del rilevamento nel settore sud-occidentale del foglio 280 fossombrone della carta geologica d'italia. boll. serv. geol. d’it., 115 (1996), pp 3-70. centamore e., jacobacci a. & martelli g., (1972) modello strutturale umbro-marchigiano. correlazioni possibili con le regioni adiacenti. boll. serv. geol. d’italia, 93, pp. 155-185. centamore e., fumanti f. & nisio s. (2002) the central-northern appennines geological evolution from triassic to neogene time. boll. soc. geol. it., vol. spec. 1, pp. 181-197. coccioni r., moretti e., nesci o., savell i d., tramontana m., veneri f., wezel f. c., con contributo di cecca f., cresta s., passeri l. (1994) assetto stratigrafico e strutturale della successione umbro-marchigiana-romagnola . guide geologiche regionali, 7, pp. 103-118. coccioni r., nesci o., tramontana m., wezel f. c., moretti e. (1987) descrizione di un livello guida “radiolaritico-bituminoso-ittiolitico” alla base delle marne a fucoidi nell’appennino umbro marchigiano. boll. soc. geol. it., 106, pp. 183192. deiana g. & pialli g. (1994) le province strutturali dell’appennino umbro-marchigiano. mem. soc. geol. it., 48, pp. 473-484. di bucci d., mazzoli s., nesci o., savell i d., tramontana m., de donatis m. & borraccini f. (2003) active deformation in the frontal part of the northern apennines: insights from the lower metauro river basin area (northern marche, italy) and adjacent adriatic off-shore. j. geodyn., 36, pp. 213-238. dil igenti a., nesci o. & savell i d. (2004) geomorphosites in the landscape of monti del furlo (northern marche apennines). il quaternario, it. journ. quat. sc., in stampa. langelier w.f., ludwig h.f. (1942) graphical method for indicatine the mineral character of natural waters. j. am. waterworkss assoc., 34, pp. 335352 mayer l., menichetti m., nesci o. & savelli d. (2003) morphotectonic approach to the drainage analysis in the north marche region, central italy. quat. internat., 101-102, pp. 157-167. nesci o. & savelli d. (1986) cicli continentali tardoquaternari lungo i tratti vallivi mediani delle marche settentrionali. geogr. fis. dinam. quat., 9, pp. 192-211. noschese t. (1984) gli acquiferi della serie marchigiana nella zona dei m.ti delle cesane-pietralata. studio delle sorgenti e delle caratteristiche chimico-fisiche delle acque. tesi di laurea inedita, università degli studi di urbino, 168 pp. sambuchi p. (2004) studio idrogeochimico delle acque sotterranee nell’area franosa dell’alta valle dell’apsa (urbino). tesi di laurea inedita, università degli studi di urbino, 137 pp. wezel f. c. (1979) the scaglia rossa formation of central italy: results and problems emerging from a regional study. acta naturalia de "l'ateneo parmense", 15 (4), pp. 243-259. 595caratterizzazione idrochimica di un acquifero ... ms. ricevuto il 26 aprile 2004 testo definitivo ricevuto il 22 dicembre 2004 ms. received: april 26, 2004 final text received: december 22, 2004 sess 1_160211.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 1. introduction coastal wetlands exist in a dynamic equilibrium between forces that lead to their establishment and maintenance and forces that lead to their deterioration (day j.w. et al., 1999). one of the most important processes currently affecting coastal wetlands is relative sea level rise (rslr). marshes survive rising water levels only if they are able to accrete at a rate sufficient to offset rslr (cahoon d. et al., 1995). in addition to longterm sea level variations, salt marsh evolution is influenced by short-term fluctuations, such as those caused by tides. in fact, during the flood events the accelerating sea level rise promotes a rapid increase not only in water depth, but also in deposition rate on the marsh platform; on the other hand, the expanding tidal prism can enhance erosion and an expansion of the channel network, reducing the marsh area (allen j.r.l.,1997). the present paper documents the evolution, in the last seventy years, of a natural salt marsh located in the venice lagoon (italy), and points out the role of sea level variations in influencing its modifications. the study was carried out through the joint analysis of several high resolution aerial photographs taken from 1938 to 2007 (which documented the tidal channel changes) and the 1938-2007 yearly time series of the rslr (including eustacy and natural and human-induced subsidence) measured at the venice tide gauge station (carbognin l. et al., 2009). 2. general characteristics of the study area the lagoon of venice, covering an area of about 550 km2, is the widest in italy and the most important survivor of a larger system of lagoons that characterized the north adriatic coast in roman times. in the whole basin, water circulation is mainly guaranteed by a semidiurnal tide, with a range of about 1.4 m, and by the bora and scirocco winds, from ne and se respectively, which trigger mixing and transport processes and locally create wind waves responsible for re-suspension of sediments in lagoon shallows (umgiesser g. et al., 2004). in addition, along the navigable channels wave motion is also induced by boat traffic, which causes local erosion. recent short-term evolution of a venice lagoon salt marsh (italy) federica rizzetto & luigi tosi istituto di scienze marine cnr, venice, italy corresponding author: f. rizzetto <federica.rizzetto@ve.ismar.cnr.it> abstract: rizzetto f. & tosi l., recent short-term evolution of a venice lagoon salt marsh (italy). (it issn 03493356, 2011) the recent geomorphological evolution of a venice lagoon salt marsh was identified through the analysis of high resolution aerial photographs taken from 1938 to 2007, and compared with the yearly time series of relative sea level rise (rslr) measured in venice in the same period. the investigations pointed out a significant retreat of the southern salt marsh margin and modifications of the marsh drainage network. in the last century, relative sea level variations, decrease of sediment input, and hydrodynamic processes were responsible for erosion in large portions of the venice lagoon tidal flats. in contrast with this general trend, the studied salt marsh was able to offset rslr. although this behavior reflected the system’s local response to many factors, relations between geomorphological modifications and sea level changes appeared clearly evident. riassunto: rizzetto f. & tosi l., evoluzione recente di una barena situata nella laguna di venezia (italia). (it issn 0349-3356, 2011) l’evoluzione geomorfologica recente di una barena situata nella laguna di venezia è stata studiata attraverso l’analisi di foto aeree ad alta risoluzione scattate dal 1938 al 2007 ed è stata poi confrontata con i valori annuali di sollevamento relativo del livello del mare (rslr) registrati a venezia nello stesso periodo. le indagini hanno evidenziato un significativo arretramento del margine meridionale della barena e modificazioni dei suoi ghebi. nell’ultimo secolo le oscillazioni del livello del mare, la diminuzione dell’apporto di sedimenti ed i processi idrodinamici hanno provocato erosione generalizzata nelle piani tidali della laguna di venezia. in contrasto con questa tendenza, la barena in esame è riuscita a contrastare il rslr. sebbene tale comportamento sia stato condizionato da molti fattori, è apparsa chiaramente evidente una stretta relazione tra le principali modificazioni morfologiche e le oscillazioni del livello marino. key words: salt marsh, tidal creeks, sea level, venice lagoon. parole chiave: barena, ghebi, livello marino, laguna di venezia  57 59 58 in the last century, erosion, scarce fluvial sediment supply, loss of material through the inlets, and rslr (enhanced by human-induced land subsidence) were responsible for the reduction and disappearance of a large portion of venice lagoon salt marshes, except for some located in the northern basin, which preserve their original characteristics and are locally growing (ciavola p. et al., 2002; cappucci s. et al., 2004). their survival mainly depends on the flooding water turbidity and on the presence of sea grass that reduces wave and tide actions and favors the entrapment of sediments and their deposition on the marsh surface (bellucci l.g. et al., 2007). one of these intertidal well preserved landform, i.e. the san felice salt marsh, was chosen as study area. it is located north of the lido inlet (fig. 1) at the confluence of two tidal channels, i.e. the gaggian and the san felice. it is crossed by a meandering-dendritic network of tidal blind-ended creeks, extending from the san felice channel to the north, which allow the distribution of water and suspended sediments on the marsh platform during tidal flow and their return to the surrounding lagoon during ebb tide. moreover, many ponds are present in the northern zone. the san felice salt marsh is composed of clayey sandy silt and is mainly colonized by halophytic species. its elevation ranges from 0.0 m to about 0.7 m a.s.l. and generally decreases from south to north; consequently, the northern part can be considered a marsh flat. the presence of the jetties at the lido inlet, built at the end of the 19th century, has greatly reduced and disturbed the sediment input from the sea to the marsh platform and enhanced high energy processes close to the inlet (day et al., 1999). 3. discussion in the last seventy years the investigated area suffered significant geomorphological modifications (fig. 2). as regards the southern salt marsh margin, close to the san felice channel, a general retreat, estimated up to about 38 m in the western sector and up to 24 m in the eastern one, occurred over the whole period. expansion of the tidal creek network was produced by tributary addition, mainly in correspondence of channel bends where the bottom shear stress arises, and headward erosion of the existing creeks, as the higher values of shear stress are registered in correspondence of the channel tips (pethick j.s., 1969; steel t.j. & pye k., 1997; feola a. et al., 2005). other channel modifications fig. 1, location of the study area. ubicazione dell'area studiata.  fig. 2, detail of the tidal creek modifications occurred from 1938 to 2007. dettaglio delle variazioni morfologiche dei ghebi verificatesi dal 1938 al 2007. f. rizzetto & l. tosi 59 ms. received: testo ricevuto il consisted of sinuosity changes, enlargement of some important creeks, meander migration, and variations of shape and distribution of pans. comparison between salt marsh evolution and rslr trend (fig. 3) over the whole period pointed out that sea level variations significantly influenced geomorphological changes. from 1938 to 1970 groundwater exploitation was responsible for high subsidence, which increased rslr rates. this process was particularly intense between 1950 and 1970 and determined a severe retreat of the salt marsh margin, increase of channel width, decrease of channel sinuosity, headward extension of creeks, and formation of new ones. after 1970 lower rslr rates were measured because the groundwater extraction was regulated. however, minor sea level fluctuations were identified: (a) between 1970 and 1990 rslr rates slowed down, (b) in the period 1990-2001 rslr grew again, (c) from 2001 and 2007 new steady conditions appeared. since 1970, margin shift was in agreement with rslr, showing retreat when rslr increased and stabilization when sea level was stable. on the other hand, modifications of the tidal creek network were only partially in agreement with rslr, showing planform morphological variations also during periods of quite steady sea level conditions. this behavior reflected the local response to many other factors, such as tides, sediment availability, vegetation growth and density, and wave action. however, results from this study pointed out that rslr alone was responsible for a large part of the geomorphological modifications occurred over the whole period. acknowledgements this study was performed within the framework of the vector (action 3 r.l. 5 cliven) and cnr-rstl n. 809 projects. part of aerial photographs is courtesy of the magistrato alle acque consorzio venezia nuova. references allen j.r.l. (1997) simulation models of salt-marsh morphodynamics: some implications for high-intertidal sediment couplets related to sea-level change. sediment. geol., 113 (3-4), 211-223. bellucci l.g., frignani m., cochran j.k., albertazzi s., zaggia l., cecconi g. & hopkins h. (2007) 210pb and 137cs as chronometers for salt marsh accretion in the venice lagoon e links to flooding frequency and climate change. j. environ. radioact., 97, 85-102, doi:10.1016/j.jenvrad.2007.03.005. cahoon d., reed d. & day j.w. (1995) estimating shallow subsidence in microtidal salt marshes of the southeastern united states: kaye and barghoorn revisited. mar. geol., 128, 1-9. cappucci s., amos c.l., hosoe t. & umgiesser g. (2004) slim: a numerical model to evaluate the factors controlling the evolution of intertidal mudflats in venice lagoon, italy. j. mar. syst., 51, 257-280. carbognin l., teatini p., tomasin a. & tosi l. (2009) global change and relative sea level rise at venice: what impact in term of flooding. clim. dyn., doi: 10.1007/s00382-009-0617-5. ciavola p., organo c., vintrò` l.l. & mitchell p.i. (2002) sedimentation processes on intertidal areas of the lagoon of venice: identification of occasional events (acqua alta) using radionuclides. j. coast. res., s.i. 36, 139-147. day j.w. jr., rybczyk j., scarton f., rismondo a., are d. & cecconi g. (1999) soil accretionary dynamics, sea-level rise and the survival of wetlands in venice lagoon: a field and modelling approach. estuar., coast. shelf sci., 49, 607-628. feola a., belluco e., d’alpaos a., lanzoni s., marani m. & rinaldo a. (2005) a geomorphic study of lagoonal landforms. water resour. res., 41, w06019, issn: 0043-1397, doi:10.1029/2004wr003811. pethick j.s. (1969) drainage in tidal marshes. in steers j.r. (ed.) the coastline of england and wales (third edition), cambridge university press, new york, 725-730. steel t.j. & pye k. (1997) the development of salt marsh tidal creek networks: evidence from the uk. in: proceedings of the canadian coastal conference, guelph, ontario, 267-280. umgiesser g., sclavo m., carniel s. & bergamasco a. (2004) exploring the bottom stress variability in the venice lagoon. j. mar. syst., 51, 161-178.  fig. 3, venice tide gauge data from 1938 to 2007. variazioni del livello marino misurate a venezia dal 1938 al 2007. recent short-term evolution of a venice ... january 14, 2011 14 gennaio 2011 imp.diolaiuti& natural assets in glacialized areas and the use of gis for the valorization of high-mountain regions guglielmina diolaiuti1,2, claudio smiraglia1,2, manuela pelfini1,2 , carlo d’agata1,2 & marco caccianiga3 1“ardito desio” earth sciences department, university of milan, via mangiagalli 34-20133 milano italy. guglielmina.diolaiuti@unimi.it 2italian glaciological committee 3université laval, québec, canada marco.caccianiga@cen.ulaval.ca abstract: g. diolaiuti et al., natural assets in glacialized areas and the use of gis for the valorization of high-mountain regions. (it issn 0394-3356, 2005). the paper presents the preliminary results obtained through an experimental project focused on the use of gis software to manage environmental data surveyed in a sample area in the high italian alps (val viola bormina, so). the processing of the data (collected from field surveys with the gps rtk technique and from aerial photogrammetry analysis) made it possible to obtain geomorphological and vegetational maps (1:10.000 scale). the environmental assets were identified in the sample area through the application of some floristic indices to the vegetational data and a national sheet for the identification and the evaluation of geosites (according to the international unesco protocol) applied to the surveyed geomorphological evidences. these assets were called “high-quality floristic and vegetational zones” in the case of the botanical assets and “geomorphological sites or geomorphosites” for the geomorphological assets. the identification of the environmental assets represents the first phase of a valorisation and tourism-promotion project regarding high mountain areas. some naturalistic educational trails were prepared for this purpose. they suggest some locations for tourists to stop and observe the main environmental features of the natural landscape (both germorphosites and high-quality floristic and vegetational zones). the trails are reported in the gis on a specific layer and the linked browser also contains logistic information (time needed to reach the trail, difficulty level, hut presence, etc.) useful for organizing the trip. an advantage of the system is that users can make queries (by using the browser and/or the links on the thematic maps) to obtain information or to make changes and variations in the trail route (for instance adding new stops in the vicinity of some of the geomorphological or botanical evidences reported on the maps, but perhaps not included along the suggested trail route). this feature makes the system flexible, serving also for school use (for preparing a school trip or taking a virtual tour of the mountain region before the real trip in the field). the distribution of this product will take place through some computer points located close to the mountain regions studied and by means of an open-source cd-rom. riassunto: g. diolaiuti et al., beni naturalistici in aree glaciali e l’uso del gis per la valorizzazione di aree di alta montagna. (it issn 0394-3356, 2005). si presentano i risultati conseguiti nell’ambito di un progetto pilota che ha visto la gestione in ambiente gis di un database georeferenziato contenente tutte le informazioni naturalistiche di un’area campione dell’alta montagna alpina italiana (val viola bormina so). l’elaborazione dei dati (sia telederivati che rilevati sul terreno attraverso campagne dedicate con l’ausilio di strumentazione gps) ha portato alla compilazione di cartografia geomorfologica e vegetazionale alla scala 1:10.000. l’applicazione di appositi indici ai dati vegetazionali e del protocollo nazionale per l’identificazione dei geositi ai dati geomorfologici ha permesso l’identificazione dei beni naturalistici presenti nell’area studiata e definiti “zone di qualità floristico-vegetazionale” per la botanica e “beni geomorfologici o geomorfositi” per la geomorfologia. l’identificazione dei beni naturalistici rappresenta la prima fase di un progetto di valorizzazione e di promozione turistica delle aree di alta montagna alpina. sono stati allestiti percorsi didattici che suggeriscono al turista frequentatore alcuni stop dai quali è possibile osservare le principali emergenze naturalistiche, i geomorfositi e le aree di qualità floristico-vegetazionali presenti. i percorsi sono inseriti nel gis in layer dedicati ed i relativi database contengono anche informazioni tecnico-pratiche (difficoltà, tempo di percorrenza) per affrontare l’itinerario. l’interattività del sistema permette, inoltre, al potenziale turista di personalizzare ed arricchire l’itinerario prescelto attingendo le informazioni dall’intero data-base naturalistico a disposizione, suggerendo un approccio didattico ed un turismo virtuale dell’area in preparazione alla vera uscita sul terreno. la divulgazione del prodotto avverrà presso opportune postazioni informatiche localizzate in prossimità delle aree studiate e attraverso cd-rom distribuiti a cura dei competenti uffici regionali. keywords: geomorphosites, high mountain environment, gis. parole chiave: beni geomorfologici, ambiente di alta montagna, gis. il quaternario italian journal of quaternary sciences 18(1), 2005 volume speciale, 275-283 1. high-mountain natural assets: previous studies and features the idea that among “cultural assets” we have to consider man-made evidences, as well as those created by nature, is not limited to scientific spheres, for it is also a common belief (panizza, 1988). the same may be said about the knowledge, valorisation and conservation required for these kinds of assets, which can be defined as true land resources (burlando, 1997a). among natural assets, geomorphological assets are the most widespread and visible (panizza, 2001). surely they are also the simplest, most understandable and recognisable because of their actions in characterizing and determining the landscape. the interest in natural assets sensu latu (biological and non-biological ones) and particularly in the geomorphological type (geomorphosites), with efforts being made for their inventory, conservation and promotion, is a relatively recent phenomenon. after some pioneer studies (for 276 g. diolaiuti et al. example nangeroni, 1968), it was only in the 1990s that a “scientific culture in geo-conservation” (translated from panizza & piacente, 2002) saw development. more recently, following the 2nd international symposium on the conservation of geological heritage in rome (1996), many efforts and projects have contributed to the growing circulation of some initiatives such as the classification, conservation and promotion of geosites. there is now a large number of papers and other published works dealing with inventories, evaluations and methodology of conservation and promotion of italian geomorphosites (see for example panizza et al., 1983; bertacchini et al., 1999 for the apennine area; burlando, 1997b; brancucci & burlando, 1999 for liguria; barca & di gregorio, 1991 for sardinia). instead, there has been less interest in highmountain areas (indicating in this non-specific way, the zones above the tree-line, smiraglia, 2001a). this could be due to numerous factors: the more limited surface extension of these areas with respect to others located downvalley, the more difficult conditions involved in visiting high-mountain lands and consequently, the problems involved in checking data collected through indirect survey techniques, the lower influx of tourists and thus the less pressing need (from a theoretical point of view) to understand the morphogenetic systems and to conserve the geomorphosites. some inventories of geomorphosites have been conducted in the province of turin (mortara, 2001), while others have focused on glacial geomorphological sites located in upper valtellina, on their promotion (diolaiuti & smiraglia, 2001; diolaiuti et al., 2001ab; 2002) and on glaciers in lombardy (pelfini et al., 1989). there are at least two strictly connected reasons suggesting a need to dedicate more interest in highmountain geomorphosites. the first one is the need for conservation and ethic promotion resulting from the increase of the tourism in high-mountain areas. this influx has made climbing and trekking popular activities not only in the alps, but also in mountain chains outside of europe such as the himalayas and the karakoram, with the inevitable growth of the magnitude of human impact and pollution. the second reason is the rapid evolution of high-mountain geomorphosites, which could shortly (a few decades) bring about not only detectable changes in their geometric and morphological features, but also their complete extinction. these last considerations may apply for particular types of morphologies, among which alpine glaciers, which with their appeal and scenic value, determine high-mountain landscapes and which, more than other natural elements of the same morpho-climatic system, are characterised by swift dynamics in responding to climatic variations through modifications in shape and volume, and through changes in the features of the landscape. in this paper, our intention is to underscore the possibility of considering glaciers and some glacier morphologies as cultural assets, more precisely as geomorphosites, and also, to suggest a method of study that is based on scientific knowledge of this natural asset, on an understanding of the natural laws governing its evolution and on an awareness of its value for mankind. we also suggest consideration of the other natural assets present in high-mountain areas and that are strictly dependent on glacier dynamics such as the floristic and vegetational assets. these biological assets respond quickly to climatic and environmental changes and have a profound impact on the mountain landscape. moreover, this kind of asset also needs to be inventoried, conserved and promoted, for an understanding of them and knowledge about them could contribute to a complete and exhaustive picture of the history of high-mountain environments (fig. 1). fig. 1 glacier as cultural asset: a black and white version of a painting of the grindelwald glacier by joann ludwig aberli (1762). il ghiacciaio come bene culturale: una versione in bianco e nero di un dipinto del ghiacciaio di grindelwald di joann ludwig aberli (1762). it is also important to note that natural processes are particularly rapid in the alpine environment and their evolution is detectable on a human time scale. therefore, the importance of glaciers as hydrological and hydro-electrical resources, as tourist attractions, as well as the geomorphological and vegetational features observable on them and on their proglacial areas, makes high-mountain zones precious lands to be conserved and promoted. 2. high-mountain tourism: distribution and differences high-mountain alpine regions are used for both traditional economical activities (agro-pastoral type) and more recently, for leisure time activities. these latter, and particularly trekking, climbing and skiing, are not distributed in a homogeneous way in the alps. they are instead concentrated in limited areas, where some elements and features of the physical landscape constitute attraction factors for tourists or where the presence of anthropic infrastructures (hotels, huts, trails, roads and cableways) make tourism possible. the result is thus that some high-mountain areas are subjected to a heavy tourist frequentation, while other areas are less well known or not known at all, and therefore completely ignored by tourists. the issue at hand is how we can contribute to an increased awareness about these lesser known areas, which are also frequently rich in unknown or undervalued natural assets, and also increase the tourist influx there, while protecting the assets. in order to obtain a greater influx to these areas, the construction of tourist infrastructures and facilities (cableways, roads, huts and hotels) is a possibility a possibility, however, that will increase not only frequentation of these zones, but also human impact on the natural landscape. if our purpose is not merely the quantitative increment of human frequentation and we aim also to increase the quality of the tourist flow, the solution may lie in our knowledge and valorisation of these areas through surveys and inventories of the existing natural assets. the environmental assets identified and inventoried have to be proposed to potential tourists in order to encourage and prepare them for a conscious use and responsible frequentation of high-mountain areas, with the aim being sustainable tourism. a first attempt to resolve this issue was proposed by the operative unit of the university of milan through the research program “valorizzazione turistica e fruizione compatibile dello spazio naturale delle alpi lombarde”, in the national cofin-murst 40% framework “la valorizzazione turistica dello spazio fisico come via alla salvaguardia ambientale” (national leader: prof. r. terranova, local coordinator: prof. m. pelfini) and in the research program “pericolosità geomorfologica in ambiente montano in relazione alle modificazioni climatiche ed alla frequentazione turistica” in the national cofin-murst 40% framework “il clima e i rischi geomorfologici in relazione allo sviluppo turistico” (national leader: prof. m. piccazzo, local coordinator: prof. m. pelfini). the study reported here proposes some methodologies for increased knowledge and valorisation of high-mountain glacial areas that are undervalued and less or not frequented at all by summer tourists. 3. applied methods this study was carried out according to the following stages and with the adoption of the following methods: 1) identification of a sample area 2) identification of the geomorphological, vegetational and floristic features by aerial photogrammetry analysis and through field surveys, combined with the gps rtk technique for the georeferencing of data. 3) data entered into a geographical browser processed by gis software. 4) selection of the surveyed features and definition of 277natural assets in ... the “geomorphosites” (according to the international protocol for the identification and evaluation of geomorphological assets) and of the “high-quality floristic and vegetational zones” (by applying botanical indices to the data collected). 5) valorization plan for the sample area by means of tourist trails to visit the environmental assets identified. 4. sample area on the basis of the authors' previous experience and knowledge of the areas, a region in upper valtellina (lombardy alps) was selected as the sample area because of its natural and anthropic characteristics. the study area is val viola bormina (so) (fig.2). this valley is divided into two sectors. in the first one, with a ne aspect, tourists are virtually an unknown presence because of the absence of lodging facilities (hotels, huts, etc.) or roads that would allow travel at least by jeep, while paths are either inexistent or poorly marked. the nw sector is instead well known and witnesses a strong influx of summer tourists due to the presence of huts and restaurants, a trail that is easily traveled by jeep and well-marked paths. the ne sector (particularly val cantone di dosdè and val dosdè) offers a wealth of geomorphological features mainly linked to present-day glaciation and glacial and periglacial morphology, in addition to a wealth of botanical features. all of the region's glaciers are located here (with the sole exception of the cima piazzi glaciers) and though the region may not reach very high altitudes (barely approaching 3,300 m), the peaks offer a picture of a high-mountain landscape, which, owing to the glaciers, stands up to any comparison with higher regions. the aim of the project was to promote frequentation of the ne valley sector through some trails that would allow tourists to understand and to learn to appreciate the natural resources present there. therefore, our attention was focused on this valley sector untouched by tourism until now, in order to identify the natural features there, particularly those of a geomorphologicalglaciological and vegetational type, and of such importance and significance as to be classifiable as natural assets (fig. 3). fig. 2 location map. ubicazione dell’area di studio. 278 5. work stages survey methods and laboratory analyses were both used for this research. in the preliminary stage, the interpretation of aerial photographs of the study area was carried out to identify the geomorphological features and the various typologies of vegetation. this first stage was followed by field surveys performed using gps instrumentation (fig. 4) as confirmation of the results of the aerial photograph analysis and to inventory all the other evidences that were not identifiable on the aerial photographs because of their small size. all the data collected were then entered in georeferenced browsers (differing for botanical and geomorphological features and for the abiotic features also divided in different layers on the base of the different processes active: glacial, periglacial, wasting of slopes, runoff water, man made) and processed by gis software to produce thematic maps (1:10,000 scale) (figs. 5a and 5b). some floristic indices applied to the vegetational data and an international protocol for the identification and the evaluation of the geosites applied to the surveyed geomorphological evidences, made it possible to identify the environmental assets in the sample area. these latter were called “high-quality floristic and vegetational zones” in the case of the botanical assets and “geomorphological sites or geomorphosites” in the case of the geomorphological assets. floristic indices (degree of rarity, naturalness and species richness) were applied to the vegetational data and non-biotic indices (educational value, scenic appeal, scientific value, rarity and uniqueness) were used for the geomorphological data to identify which of the various evidences (both vegetational and geomorphological ones) fully qualify as natural assets because of their special characteristics (fig. 6). an increasing numerical score (scale 1-5) has been applied to quantify the value of each surveyed evidence for each considered index (both abiotic and biotic ones). the browsers allowed to analyze all the inserted values and to verify the possibility for each evidence to be considered as a natural asset. we considered natural asset only the vegetational evidences that have a value ≥ 3 for all the three considered indices or the geomorphological evidences that reach (considering the sum of all the indices) a value of 15. the survey of the natural assets was conducted with the aid of gps instrumentation in order to set up a georeferenced browser, which is indispensable for entering data in a gis. the data on natural assets that were gathered during special survey campaigns were organized in dedicated layers for the purpose of producing thematic maps (glaciological, geomorphological and vegetational maps), sectorial maps or maps derived from the overlapping of different thematic layers. emergences defined as natural assets as a result of the previous stage of analyses, were considered to be the quintessential points of the areas studied, and were thus utilized as points of attraction for tourists also interested in the scientific and cultural aspects of the areas. g. diolaiuti et al. fig. 3 natural assets in val viola: glaciers, peaks and moraines in the ne sector. beni naturali in val viola: ghiacciai, cime di montagne e morene nel settore ne. fig. 4 gps survey on dosdè est glacier. rilievo gps sul ghiacciaio di dosdè est. 279natural assets in ... fig. 5a geomorphological map of the studied area processed by gis software (all the thematic layers are showed). carta geomorfologica dell’area studiata elaborata con programmi gis (tutti i layers tematici sono visualizzati). using the data collected, hypotheses were then formulated concerning the possible valorization of the study area. more specifically, the data on natural elements entered into the browsers for the preparation of the thematic maps, were used to propose multi-theme itineraries through the valley sector (the ne one), which is not as well known, but rich in interesting elements. the objective is to promote tourism through the identification and interconnection of preferential observation points. each itinerary lies within a dedicated layer and is characterized by a linked browser, in which it is possible to find data on the characteristics that make the natural element an environmental asset, as well as 280 information on logistics for the route proposed (traveling time, degree of difficulty, distances from the main lodging or assistance facilities such as camps and huts) (fig. 7). therefore, single-theme or multi-theme itineraries are proposed to the tourist to use and gain knowledge about this high-altitude valley. special attention is given to the proglacial areas, which have undergone intensive changes in the recent period. in these regions, the recent rapid glacier recession, followed by the brief advancing phase of the 1970s and 1980s, has left relatively ample areas exposed. geomorphological evidences left by glacial activity are easily observable there, particularly the newly formed moraines (diolaiuti, 2001; rossi et al., 2003), roches moutonnées, and subglacial morphological features, where stream, periglacial and slope morphodynamics are presently predominant. geomorphological interests can be combined with botanical interests. in fact, the pioneer vegetation is colonizing larger sectors of the area, transforming them g. diolaiuti et al. fig 5b map about the vegetation quality of the studied area processed by gis software (all the thematic layers are showed). carta della qualità vegetazionale dell’area considerata elaborata con programmi gis (tutti i layers tematici sono visualizzati). into actual open-air laboratories. in addition to the preparation of thematic maps and specific tour routes, the environmental assets inventoried and entered in the gis offer users an interactive selection regarding the route to follow or the natural asset to identify and visit. so the users have the option of making queries (using the browser and/or the links on the thematic maps) to obtain information or to make changes and variations in the routes (for instance adding new stops in the vicinity of some of the geomorphological or botanical assets reported on the maps, but perhaps not included on the suggested path). this feature makes the system flexible, serving also for school use (for preparing a school trip or taking a virtual tour of the mountain region before the real trip in the field). in this manner, tourists will have the option of locating the assets in the database, taking into account scientific criteria (quantitative and descriptive data concerning the assets) and other criteria concerning logistics and recreational aspects. for the concluding stage of this research, the proposal consists of making available information on the tour routes and the related natural aspects through the creation of a webgis dedicated to the promotion of natural resource tourism in val viola. circulation of all the material in the school system is another possibility. this would allow schools that are planning trips to the area to prepare students in advance as to what they will find there, as well to offer a sort of virtual tour with the gis prior to the actual trip. on-site signs and markings of the proposed itineraries must be carried out with the intention of keeping environmental impact to an absolute minimum, taking full advantage of any pre-existing paths or tracks. in this regard, the suggestion has been made to follow the respective indications on the subject contained in a path manual published by the italian alpine club (club alpino italiano, 1999). in practical terms, a general information panel board is a possibility for the valley entrance zone. the board would serve for viewing the routes in their entirety, along with a description of the respective observation points. in cases where paths are unmarked, the routes will be marked by trail sign stakes 281natural assets in ... fig. 6 the international sheet used for the inventory of the geomorphosites surveyed in the studied area. each point of the sheet became a field in the geomorphological browsers linked to thematic layers (divided on the base of the different geomorphological processes active: glacial, periglacial, wasting of slope, runoff water , man-made) in the gis project carried out for this study. il protocollo internazionale utilizzato per il catasto dei geomorfositi rilevati nell’area di studio. ogni punto del protocollo inizia con un campo nelle tabelle geomorfologiche collegate ai layers tematici (divisi sulla base dei differenti processi geomorfologici attivi: glaciali, periglaciali, gravitativi, di scorrimento delle acque superficiali , antropiche) nel progetto gis portato avanti per lo studio. fig. 7 an example of a thematic browser l inked to each layer. un esempio di tabella tematica collegata ad ogni layer. and cairns, made of natural materials characterized by low environmental impact. 6. conclusions the work presented here represents an example of the combination of research and its application. in fact, it is based on traditional methodologies adopting geomorphological and botanical analyses in high-altitude regions (identification of geomorphological and botanical evidence, along with the preparation of the relative maps). the analyses, however, are also utilized for the identification and selection of the high-mountain natural assets. the most important assets characterising the high-mountain landscape have been identified as glaciers and proglacial morphologies, with the resulting necessity to survey, inventory, evaluate and protect them. the different values (scientific, cultural, socioeconomic and scenic) of these assets make them natural resources that cannot be neglected and identifiable not only as objects of the natural landscape, but also as sensitive systems (smiraglia, 2001b) and true examples of geo-diversity. moreover, glacier action on the extension, velocity and degree of development of the vegetational distribution is underscored, for it adds further value to the high-mountain environment and can itself be defined as a natural asset. the use of the international protocol for the identification of the geomorphosites is suggested and applicable to glacier lands and morphologies. however, some changes in this protocol are also required in order to take into account the characteristics and features specific to these landforms. it is particularly important to underscore two features that augment the scientific quality of glacier environments, but also the difficulties involved in studying them. the first feature is the rapid evolution time of alpine glaciers and glacier morphologies in responding to the climatic and environmental driving factors of landscape change. the second factor is that they represent excellent keys for the study and understanding of the world's global equilibrium. regarding the fast evolution of high-mountain landscape changes, the rapidity, dimensions and dynamics of the changes in glaciers, allow the glaciers themselves to take on a representative and emblematic role in the global environmental system and in its delicate and changeable balance. glacier changes over time do not affect solely their scientific value, but also the other values of these landforms, particularly their scenic value. a good example of this last feature comes from the comparison of historical iconographies. it provides further clarification of the weight of glaciers in modelling the high-mountain landscape and their influence on human perception of the alpine environment. as for the function of glaciers in the world's environmental balance, we must stress the key role they play in all scientific research aimed at understanding the relationships between the lithosphere, hydrosphere and atmosphere, in reconstructing past climate history and in terms of their importance as sensitive climate indicators. all things considered, glaciers really can represent true environmental assets and natural resources and to repeat the words of sharp (1988), they are “unusual, intriguing elements of our natural environment..., a never-ending source of fascinating information and discovery..., in themselves beautiful and mysterious. by their actions they have helped create some of the most spectacular scenery of this earth.” in conclusion, the main aim of the project was to increase popular knowledge about high-mountain regions through the promotion of a tourism that is nondestructive and of low impact, especially with respect to areas where tourist traffic is inexistent or very limited. the application of a gis revealed to be a useful and flexible tool for this purpose and it allowed for simple management of all the natural assets surveyed. acknowledgements the authors thank anna lombardi for collecting and processing part of the field data. the research was conducted as part of project “pericolosità geomorfologica in ambiente montano in relazione alle modificazioni climatiche ed alla frequentazione turistica” in the national cofin-murst 40% framework “il clima e i rischi geomorfologici in relazione allo sviluppo turistico” (national leader: prof. m. piccazzo, local coordinator: prof. m. pelfini). references barca s. & di gregorio f. (1991) proposta metodologica per il rilevamento dei monumenti geologici e geomorfologici bollettino aic, 83. bertacchini m., giusti c., marchetti m., panizza m. & pellegrini m. (eds.) (1999) i beni geologici della provincia di modena artioli, modena, 1999, 104 pp. brancucci g. & burlando m. (1999) geosites inventory in liguria (northern italy): activation phases and its possible future developments in: societad geologica de espana (ed.), towards the balanced management and conservation of the geological heritage in the new millennium, iii intern. symp. progeo on conservation of geological heritage, proc. book, pp. 441-446. burlando m. (1997a) la tutela del patrimonio naturale: le emergenze geologico-geomorfologiche in “pro natura”, genoa, xvi (71), pp. 16-20. burlando m. (1997b) censimento dei beni ambientali a carattere geologico nell'ambito delle aree protette della regione liguria: primo contributo relativo al parco naturale regione del bric tana, comune di millesimo (sv) – in: ii intern. symp. on conservation of our geological heritage, rome pre-prints, 16. club alpino italiano comitato scientifico centrale (1999) sentieri: ripristino manutenzione segnaletica i manuali del club alpino italiano n.6, 137 pp. diolaiuti g. (2001) evoluzione recente dei sistemi morfodinamici nelle aree proglaciali della val viola (alpi lombarde) uomo e ambiente d’alta montagna. dalla conflittualità all’integrazione, msgi, 282 g. diolaiuti et al. lxvi, rome, pp. 245-262. diolaiuti g. & smiraglia c. (2001) a new method for sustainable ecotourism in protected mountain environment areas: the glacier trai ls in the lombardy alps geotema, bologna, 15, pp.4245. diolaiuti g., d'agata c., pelfini m. & smiraglia c. (2001a) gestione tramite gis di beni geomorfologici, glaciologici e naturalistici per la valorizzazione mediante un turismo sostenibile di aree di alta montagna abstracts convegno gis per la tutela e valorizzazione dei beni ambientali e storico-culturali, florence. diolaiuti g., pelfini m., smiraglia c. & codazza v. (2001b) il turismo estivo al passo dello stelvio (alpi centrali): problemi e prospettive della fruizione antropica di un ghiacciaio alpino in un’area protetta, geotema, bologna, 15, pp. 46-55. diolaiuti g., d’agata c., pelfini m. & smiraglia c. (2002) geomorphosites in glacialized areas: routes in the upper valtellina for the valuing of the high mountain environment – in: p. coratza & m. marchetti (eds.), proceedings workshop geomorphological sites: research, assessment and improvement, modena italy, 19-22 june, 2002, pp. 57-58. mortara g. (2001) i geositi della provincia di torino, proposte di valorizzazione pubbl. provincia di torino, turin. nangeroni g. (1968) protezione dei fenomeni geologici e geomorfologici in italia atti ii conv. pro natura italica, varallo, ass. pro natura valsesiana, varallo. panizza m. (1988) geomorfologia applicata. metodi di applicazione alla pianificazione territoriale ed alla valutazione di impatto ambientale la nuova italia scientifica, rome, 342 pp. panizza m. (1992) geomorfologia bologna, pitagora,.396 pp. panizza m. (2001) problemi attuali di rischio e impatto ambientale in alta montagna uomo e ambiente d’alta montagna. dalla conflittualità all’integrazione, msgi, lxvi, rome, pp. 5368. panizza m. & piacente s. (2002) geositi nel paesaggio italiano: ricerca, valutazione e valorizzazione. un progetto di ricerca per una nuova cultura geologica in: i geositi – http://www.geologia.com/geositi/panizza.html”. panizza m., bertolani m., carton a. & solmi m. (1983) principali evidenze geomorfologiche della provincia di modena. in: various authors (eds.), relazione sullo stato dell'ambiente nella provincia di modena, provincia di modena, pp. 185-193. pelfini m. & smiraglia c. (2003) i ghiacciai, un bene geomorfologico mutevole ed in rapida evoluzione bollettino società geografica italiana serie xii, vol viii, pp. 49-68. pelfini m., smiraglia c. & voltolini c. (1989) il glacialismo attuale delle alpi lombarde: conoscenza, utilizzazione di un particolare bene naturale l'italia che cambia. il contributo della geografia, vol. ii, catania, pp. 479-490. rossi s., diolaiuti g., forasacco e., montrasi l., mutti m., pelfini m., smiraglia c. & spreafico p. (2003) evidenze geomorfologiche della più recente espansione glaciale correlabile all’episodio freddo degli anni ’50-’70 del xx secolo sulle alpi lombarde in “risposta dei processi geomorfologici alle variazioni ambientali”, atti convegno conclusivo, bologna, 10-11 febbraio 2000, pp. 377-395. sharp r. p. (1988) living ice. understanding glaciers and glaciation cambridge, university press, 145 pp. smiraglia c. (2001a) uomo, ambiente, alta montagna. nodi problematici e ipotesi di definizione uomo e ambiente d’alta montagna. dalla conflittualità all’integrazione, msgi, lxvi, rome, pp. 17-24. smiraglia c. (2001b) ghiacciai: da oggetti del paesaggio a sistemi sensibili “ghiacciai e aree protette atti del convegno internazionale di sondrio, 1997”, sondrio, centro documentazione aree protette, pp. 113-125. 283natural assets in ... schede di rilevamento geomorfologico di alvei fluviali massimo rinaldi dipartimento di ingegneria civile e ambientale, università di firenze e-mail: mrinaldi@dicea.unifi.it riassunto: rinaldi m., schede di rilevamento geomorfologico di alvei fluviali (it issn 0394-3356, 2008). si propone una serie di schede per il rilevamento geomorfologico di alvei fluviali. esse sono utilizzate per riportare in maniera sistematica ed organizzata le osservazioni e le misure quantitative da effettuare durante un rilievo geomorfologico sul terreno di un tratto di un corso d'acqua, integrandole con altri dati ed informazioni preesistenti (rilievi topografici esistenti, foto aeree). tali schede derivano da una semplificazione di quelle proposte da th o r n e (1998), integrandole con osservazioni ed informazioni più dettagliate riguardo le variazioni morfologiche passate e le tendenze evolutive attuali. il gruppo completo si compone di tre parti: (1) caratteristiche morfologiche attuali; (2) variazioni morfologiche; (3) tendenze attuali. le tre parti si differenziano tra loro per la scala temporale a cui si fa riferimento nelle osservazioni: (1) le caratteristiche morfologiche attuali si riferiscono alla scala temporale attuale, cioè si riportano le forme ed i processi osservati al momento della compilazione delle schede; (2) le variazioni morfologiche si riferiscono alla scala temporale degli ultimi 100-150 anni; (3) le tendenze attuali si riferiscono alla scala temporale degli ultimi 10-15 anni. se ne descrivono inizialmente alcune caratteristiche generali, quali i campi di applicazione, la lunghezza del tratto da rilevare, le possibili misure da effettuare per integrare le osservazioni di campo. successivamente si descrivono brevemente le varie parti di cui si compone ogni scheda. tali schede, oltre che per una caratterizzazione morfologica generale del tratto, possono essere utilizzate per classificare il corso d'acqua non tanto in funzione delle forme (come generalmente accade nella maggior parte delle classificazioni morfologiche di alvei fluviali), quanto piuttosto in funzione delle variazioni passate e delle tendenze attuali, offrendo in tal modo molte potenziali applicazioni nel campo della gestione dei corsi d'acqua. abstract: rinaldi m., geomorphological sheet forms for river channel survey (it issn 0394-3356, 2008). during the last years, fluvial geomorphologists have experienced an increasing need to develop schemes to evaluate channel processes, adjustments and trends by a field survey. stream reconnaissance field survey can be defined as a field procedure for the collection of morphological data and information, possibly using specific record sheets aiming to collect data in a systematic and organised way (downs & thorne, 1996; thorne, 1998). definition of recent and present channel adjustments is fundamental in studies concerning channel dynamics. while sufficient data is usually available to reconstruct planform changes, more difficulties concern the definition of altimetric adjustments (incision or aggradation) of the channel bed, given that past topographic surveys are often limited or not available. a set of record sheet forms for field surveys has been developed with the specific aim of facilitating interpretation and classification of channel adjustments. the proposed sheets partly derive from a simplification of previous record sheets proposed by thorne (1998), and from further developments of record sheet forms used in previous geomorphological projects. they have been adapted to the specific scopes of the prin 2005 project "present and recent dynamics of river channels in northern and central italy: evolutionary trends, causes and management implications" (miur). the main focus of these sheets is therefore the interpretation of channel adjustments, rather than a simple description of channel forms. the forms, although suitable for all types of alluvial river channels, have been developed with particular reference to the river types investigated within the prin 2005 project, that are gravel-bed rivers with wandering or braided morphologies. the complete set of sheets include three distinct parts: (1) geomorphological characterization. it consists of a general description of the morphological features and processes, including a morphological sketch of the site, a description of the different geomorphic surfaces, a representative cross-section, channel sizes, sediment properties, river banks, vegetation, and human interventions. (2) morphological changes. this sheet refers to the description of the channel changes during a time scale of about 100 150 years, with the scope of describing the net changes which occurred in this interval. it is compiled by a combination of available data (aerial photos, topographic surveys) that need to be collected and pre-processed before the survey, and field evidence. three main sections are distinguished: (a) width changes (narrowed, unchanged, widened); (b) pattern changes; (c) vertical changes (incised, unchanged, aggraded). (3) present trends of adjustment. this sheet refers to the time scale of the last 10-15 years, with the specific scope of interpreting ongoing channel adjustments. similarly to the previous record sheet form, aerial photos and topographic data are used when available. present adjustments in channel width and pattern are usually identified on the basis of the two most recent aerial photos available, with the support of field evidence. because topographic data is seldom available, the main focus of this form is on a series of selected diagnostic variables (field evidence) to identify vertical adjustments (incising, equilibrium, aggrading). the record sheets have been applied to a number of representative rivers (magra, panaro, cecina, piave, tagliamento, etc.). these sheet forms can be utilised for a classification of the river channel based on recent channel changes and present trends of adjustments rather than simply on channel form, as generally done in most of the existing morphological stream classifications. parole chiave: rilevamento geomorfologico, schede, alvei fluviali keywords: stream reconnaissance, sheet forms, channel adjustments il quaternario italian journal of quaternary sciences 21(1b), 2008 353-366 1. introduzione le variazioni morfologiche e le tendenze evolutive di alvei fluviali rappresentano una conoscenza fondamentale in qualunque studio di dinamica fluviale, sia esso funzionale all'individuazione delle condizioni di rischio da dinamica d'alveo, che finalizzato alla gestione dell'alveo e dei suoi sedimenti o di riqualificazione fluviale. per quanto riguarda l'analisi delle variazioni planimetriche dell'alveo, in genere (almeno per alvei fluviali di sufficienti dimensioni) l'esistenza di foto aeree attuali 354 m. rinaldi e pregresse permette di disporre di un numero sufficiente di dati. le variazioni della quota del fondo sono invece più difficili da investigare, essendo i rilievi topografici pregressi in genere in numero limitato o spesso del tutto assenti. durante gli ultimi anni si registrano importanti e rapidi progressi tecnico-scientifici per il rilevamento di alvei fluviali (gps, laser scanning, fotogrammetria, sistemi di monitoraggio, ecc.) (si veda ad es. hi c k s e t a l., 2008; mi l a n et al., 2007); tuttavia tali tecnologie meglio si adattano a studi specifici di monitoraggio morfologico, piuttosto che alla ricostruzione delle variazioni passate e delle tendenze evolutive recenti. inoltre, per studi a scala di sistema fluviale e condotti in un periodo di tempo relativamente breve, come accade nel caso di ricerche applicate alla gestione del corso d'acqua, le risorse ed i tempi spesso non sono sufficienti per l'applicazione di tecnologie avanzate di monitoraggio. nello stesso tempo, si è registrato un crescente interesse nel campo della dinamica fluviale a sviluppare ed applicare schemi per valutare gli aspetti geomorfologici di un corso d'acqua sulla base del rilevamento sul terreno, ciò soprattutto a seguito del crescente coinvolgimento degli aspetti geomorfologici nei progetti di gestione e di riqualificazione di alvei fluviali. il rilevamento geomorfologico permette una raccolta diretta di informazioni morfologiche, utilizzando specifiche schede da riempire durante la ricognizione che riportino in maniera sistematica ed organizzata le osservazioni qualitative e le eventuali misure da effettuare (thorne & easton, 1994; downs & thorne, 1996; th o r n e, 1998). come descritto più in dettaglio nella prossima sezione, esistono varie procedure morfologiche proposte e varie sono le applicazioni in italia. nonostante ciò, la proposta di nuove schede di rilevamento geomorfologico di alvei fluviali deriva da alcune esigenze e necessità, che possono essere sintetizzate come segue: (a) sviluppare una versione semplificata delle schede proposte da th o r n e (1998), le quali possono risultare troppo dettagliate per alcuni aspetti e richiedere tempi lunghi per la loro applicazione. versioni semplificate delle schede di thorne sono peraltro già state impiegate nell'ambito di recenti progetti di ricerca (siviglia et al., 2004; rinaldi, 2005; 2007) e riportate in govi & su r i a n (2003). le schede proposte in questa nota rappresentano un ulteriore sviluppo delle versioni precedenti. (b) necessità di finalizzare maggiormente le osservazioni per l'interpretazione delle variazioni morfologiche recenti e delle tendenze evolutive attuali, per rispondere alle esigenze specifiche del progetto “dinamica recente ed attuale di alvei fluviali in italia centro-settentrionale: tendenze evolutive, cause ed implicazioni applicative” (prin 2005) nell'ambito del quale questa attività si inserisce. vanno infine aggiunte le nuove motivazioni legate alla necessità dell'applicazione della direttiva quadro acqua 2000/60 la quale richiede una valutazione del discostamento di un corso d'acqua rispetto ad un suo stato di riferimento. in quest'ottica, la conoscenza delle variazioni avvenute rispetto ad una condizione del passato più naturale e delle tendenze evolutive (ulteriore discostamento o recupero morfologico) possono essere di fondamentale importanza e sono aspetti di cui raramente si tiene conto nelle attuali metodologie di caratterizzazione dello stato attuale di un corso d'acqua. l'obiettivo di questo articolo è pertanto quello di proporre un nuovo insieme di schede geomorfologiche di alvei fluviali che vadano a soddisfare tali esigenze. si riporta pertanto in questa nota l'insieme completo delle schede, illustrandone la struttura e le principali caratteristiche, rinviando invece a successive pubblicazioni per una spiegazione dettagliata dei termini utilizzati e delle metodologie di rilievo. 2. rilevamento geomorfologico di alvei fluviali il rilevamento geomorfologico sul terreno di alvei fluviali (stream reconnaissance field survey: th o r n e & ea s t o n, 1994; do w n s & th o r n e, 1996; th o r n e, 1998) può essere definito come una procedura di raccolta di informazioni morfologiche, in genere attraverso l'uso di schede da riempire durante il sopralluogo sul terreno, che riportino in maniera sistematica ed organizzata le osservazioni e le misure quantitative da effettuare. tale rilevamento non è da intendere come un sostituto o un'alternativa ad altri tipi di dati, ma il suo vantaggio è quello di permettere di raccogliere i dati e le informazioni necessarie durante il rilevamento sul terreno. esso si può quindi integrare ad altri tipi di metodi (studio delle variazioni storiche e recenti dell'alveo) e/o può essere seguito da una serie di passi successivi (monitoraggio, modellazione e quantificazione dei processi, ecc.) che possano permettere una previsione delle possibili tendenze evolutive future (downs & thorne, 1996). in molti progetti, tuttavia, a causa di limitazioni di tempo e di risorse, il rilevamento geomorfologico costituisce una delle poche soluzioni percorribili per consentire un'interpretazione delle tendenze evolutive ed in tal caso assume rilevanza ancora maggiore. per quanto riguarda la scala spaziale ed il grado di dettaglio di un rilevamento geomorfologico, generalmente si tende a distinguere tra un rilevamento geomorfologico iniziale del corso d'acqua (initial stream reconnaissance), cioè una prima ricognizione più speditiva condotta alla scala dell'intero sistema fluviale, da un rilevamento geomorfologico di dettaglio del corso d'acqua (detailed stream reconnaissance), condotto alla scala del singolo sito o tratto. il rilevamento geomorfologico iniziale è generalmente eseguito attraverso brevi visite nel maggior numero possibile di punti dai quali l'alveo è facilmente accessibile o visibile (tipicamente in corrispondenza di tutti i ponti presenti), ma può essere eseguito anche attraverso uno specifico volo aereo, in elicottero a bassa quota o percorrendo il corso d'acqua attraverso una imbarcazione. il rilevamento geomorfologico di dettaglio invece viene condotto esclusivamente sul terreno, percorrendo un determinato tratto del corso d'acqua, anche se tale attività generalmente viene integrata da altri tipi di dati (ad esempio l'analisi delle foto aeree disponibili del tratto). sono state sviluppate varie procedure e schede di rilevamento di campo adatte a diverse scale e con vari scopi, dalla valutazione dell'instabilità di un tratto di alveo alla classificazione delle condizioni 'idromorfologiche' del corso d'acqua. in tabella 1 si riportano gli esempi più significativi di procedure sviluppate con varie finalità specifiche. per quanto riguarda le loro applicazioni in campo nazionale, l'indice di instabilità potenziale (simon et al., 1989; simon & downs, 1995) è stato per primo applicato in uno studio relativo ai fiumi della toscana (catani et al., 1995). le schede di thorne (1998), certamente le più complete nel campo del rilevamento geomorfologico di alvei fluviali, sono state prevalentemente utilizzate in studi specifici sulla stabilità di sponde fluviali (ad es. ri n a l d i & ca s a g l i, 1999; dapporto et al., 2003). infine, si cita la procedura river habitat survey (rhs: ea, 1997; 2003; ra v e n et al. , 1998) ed il successivo caravaggio (core assessment of river habitat value and hydro-morphological condition: buffagni et al., 2005), suo adattamento al contesto italiano e mediterraneo, seppure si tratti di una metodologia che non nasce in maniera specifica per la caratterizzazione morfologica o per l'interpretazione delle tendenze evolutive di alvei fluviali. in essa, infatti, la classificazione degli aspetti morfologici assume un ruolo molto rilevante, soprattutto nell'ottica del recepimento della direttiva quadro acqua 2000/60. 3. schede di rilevamento le schede di rilevamento geomorfologico di alvei fluviali, riportate integralmente in fondo all'articolo (disponibili anche alla pagina w w w . d i c e a . u n i f i . i t / m a s s imo.rinaldi/_private/schede), si compongono complessivamente di tre parti: (1) caratteristiche morfologiche attuali (4 schede); (2) variazioni morfologiche (1 scheda); (3) tendenze attuali (1 scheda). le tre parti si differenziano tra loro per la scala temporale a cui si fa riferimento nelle osservazioni: (1) le caratteristiche morfologiche attuali si riferiscono alla scala temporale attuale, cioè si riportano le forme ed i processi osservati al momento della compilazione delle schede; (2) le variazioni morfologiche si riferiscono alla scala temporale degli ultimi 100-150 anni; (3) le tendenze attuali si riferiscono alla scala temporale degli ultimi 10-15 anni. tali schede, come anticipato precedentemente, derivano da una semplificazione di quelle proposte da th o r n e (1998), ed allo stesso tempo dall'esigenza di 355schede di rilevamento geomorfologico ... una maggiore focalizzazione sulle variazioni morfologiche e sulle tendenze attuali, con particolare riferimento ai corsi d'acqua italiani. le schede di thorne rimangono le più indicate per rilievi di maggior dettaglio associati a studi più specifici sulla morfologia dell'alveo o, soprattutto, sui processi e sulla stabilità delle sponde fluviali. viceversa, le schede qui proposte possono essere anche ulteriormente semplificate, impiegandole per una ricognizione più speditiva (initial stream reconnaissance) ed omettendo alcune parti ritenute non fondamentali in una fase iniziale. le schede si applicano ai tratti alluvionali mobili dei corsi d'acqua principali di un bacino idrografico, essendo focalizzate sul riconoscimento della varietà di forme e sull'osservazione di variazioni morfologiche verificatesi nel tempo. non sono invece ben applicabili al caso di torrenti montani, dove esiste una minore diversità morfologica e dove le variazioni morfologiche sono in genere più limitate rispetto ai fiumi di pianura. tuttavia, le schede comprendono anche alcune caratteristiche di questi tipi di corsi d'acqua, e pertanto sono applicabili anche ad essi riempiendo solo le voci ad essi riferite ed omettendo quelle relative a fiumi di pianura; ciò anche tenuto conto del fatto che talora gli stessi alvei alluvionali mobili possono avere dei tratti intermedi semiconfinati con caratteristiche simili a torrenti montani, quali ad esempio affioramenti rocciosi in alveo e forti pendenze. per quanto riguarda le strategie di rilevamento ed in particolar modo la lunghezza di un tratto rappresentato da un singolo gruppo di schede, esse devono essere definite all'inizio dello studio in funzione degli scopi, della durata e delle risorse disponibili. spesso un tratto di studio è sufficientemente uniforme da un punto di vista morfologico da poter essere coperto da un'unica serie completa di schede. tuttavia, dove esistono marcate variazioni morfologiche all'interno di un certo tratto, può essere necessario suddividerlo in una serie di sottotratti più brevi. al livello di maggior dettaglio possibile, per corsi d'acqua a canale singolo si ritiene comunemente che la lunghezza minima di un tratto, affinché sia significativo, debba essere dell'ordine di 10-20 volte la larghezza dell'alveo stesso (th o r n e, 1998). tuttavia, nel caso di alvei a canali intrecciati o di metodo finalità riferimenti applicazioni in bibliografici italia valutazione specifico per la valutazione simon et al. (1989); catani et al. (1995) dell'instabilità dell'instabilità di un alveo simon & downs (1995) potenziale fluviale, soprattutto in corrispondenza di ponti schede di rilevamento procedura sistematica di thorne & easton (1994); rinaldi & casagli (1999); geomorfologico raccolta informazioni e dati su thorne et al. (1996a, b); dapporto et al. (2003) forme e processi utilizzabile thorne (1998) per varie finalità river habitat survey censimento degli habitat in ea (1997, 2003); buffagni et al. (2005) (rhs) caravaggio relazione alle caratteristiche raven et al. (1998); idromorfologiche del corso buffagni et al. (2005) d'acqua tab. 1 principali metodi che includono il rilevamento sul terreno di caratteristiche morfologiche di alvei fluviali per varie finalità e principali applicazioni in italia. main field methods including a survey of channel morphological characteristics for various aims and main applications in italy. tipo transizionale (wandering), tale lunghezza può essere eccessiva, data la larghezza dell'alveo in genere relativamente grande. l'estrema variabilità morfologica all'interno di un tratto potrebbe quindi risultare difficilmente rappresentabile in un singolo gruppo di schede. pertanto, nel caso di alvei di una certa dimensione, è opportuno che la lunghezza del tratto investigato sia dell'ordine di 1-2 volte la larghezza (e comunque dell'ordine di 500 m al massimo). seppure le schede siano finalizzate ad un rilevamento sul terreno, esse richiedono l'integrazione con altri tipi di informazioni e dati che presuppongono un lavoro preliminare, in particolar modo l'acquisizione di dati desunti da carte topografiche e da foto aeree. ciò comporta il vantaggio per il rilevatore di recarsi sul terreno avendo già una conoscenza delle caratteristiche passate ed attuali del corso d'acqua. seppure le foto aeree rappresentino i supporti più importanti e di più facile reperimento, le immagini satellitari con alta risoluzione a terra stanno acquisendo sempre maggiore diffusione e possono anche esse essere impiegate per tali scopi. infine, è opportuno sottolineare che le osservazioni raccolte durante la compilazione delle schede non sono da intendersi come sostitutive di misure, ma al contrario sono possibilmente da abbinare a vari tipi di misure, quali: (a) rilievo topografico del profilo del fondo e di sezioni rappresentative; (b) misure granulometriche; (c ) misure per la caratterizzazione dei sedimenti di sponda (in studi specifici riguardanti la stabilità delle sponde); (d) misure effettuate sui detriti legnosi (in studi specifici su questi aspetti). 3.1 caratteristiche morfologiche attuali la prima parte, comprendente quattro schede, ha come oggetto la descrizione delle caratteristiche morfologiche attuali dell'alveo. si compone a sua volta di varie sezioni, brevemente descritte di seguito. 1. generalità: si riportano alcune informazioni di carattere generale, quali la data, il corso d'acqua, il tratto, i rilevatori e la posizione del sito di rilevamento. 2. caratteristiche morfologiche generali. si descrivono le caratteristiche essenziali per una prima definizione della morfologia dell'alveo (confinamento, morfologia planimetrica, barre, sedimenti, configurazione e controlli del fondo). per quanto riguarda le tipologie d'alveo, i termini riportati tengono conto delle varie classificazioni proposte in letteratura (ke l l e r h a l s et al. , 1976; br i c e, 1984; sc h u m m, 1977; 1985; ro s g e n, 1994), sintetizzate in thorne (1997), inclusi alcuni termini relativi a morfologie frequenti nel contesto italiano (sinuoso a barre alternate, transizionale o wander i n g) (ri n a l d i, 2003; su r i a n & ri n a l d i, 2003). per le tipologie di barre, si fa riferimento alla classificazione riportata da ke l l e r h a l s et al. (1976), mentre per le configurazioni del fondo si riportano le cinque tipologie principali definite da mo n t g o m e r y & bu f f i n g t o n (1997). 3. schema morfologico planimetrico. viene tracciato uno schema generale che metta in evidenza le principali caratteristiche morfologiche del tratto (andamento del canale o dei canali e delle barre, altre superfici, opere, punti di ripresa fotografica, ecc.). 4. superfici. vengono riportate le superfici morfologiche osservate nel tratto (canale, barre attive e barre alte, isole, berme, piana inondabile, canali secondari, terrazzi o versanti che eventualmente delimitano l'alveo). i termini adoperati tengono conto di quanto riportato da vari autori in letteratura (in particolare os t e r k a m p & hu p p, 1985; hu p p & os t e r k a m p, 1996; thorne, 1997). in particolare, le isole si differenziano dalle barre longitudinali per essere delle forme più stabili e ricoperte da vegetazione (th o r n e, 1997; gurnell et al., 2005), mentre le barre alte presentano caratteristiche intermedie tra piana inondabile e barre (hu p p & ri n a l d i, 2007), e si distinguono da queste ultime per caratteristiche topografiche (posizione topografica generalmente più alta), tessitura (è in genere presente una consistente quantità di sabbia) e vegetazione (in genere si osserva una consistente copertura erbacea ed arbustiva). 5. schema sezione. alla descrizione precedente si abbina anche in questo caso uno schema che esemplifichi le superfici presenti e la loro disposizione altimetrica in sezione. 6. caratteristiche e dimensioni alveo. in questa sezione si forniscono indicazioni più precise sulle caratteristiche della corrente, sulle dimensioni dell'alveo di piena (bankfull), secondo le definizioni di leopold et al. (1964) e di williams (1978), e sulle dimensioni dei sedimenti d'alveo, richiedendo l'inserimento di alcune misure da effettuare in campo (larghezza dell'alveo, diametro mediano dei sedimenti, ecc.). per quanto riguarda le varie tecniche di misura dei sedimenti, si rimanda alla rassegna di bu n t e & ab t (2001). si è ritenuto opportuno inserire in questa parte anche una descrizione dei tipi di flusso osservati al momento del rilevamento, secondo la classificazione definita originariamente nell'ambito del river habitat survey (ea, 1997; raven et al., 1998). questi rappresentano infatti alcune tra le caratteristiche più importanti sulle quali si basa la classificazione dei tipi di habitat nella procedura rhs-caravaggio. 7. sponda sinistra e destra. in questa scheda si fornisce una descrizione delle due sponde, riportandone la geometria, i sedimenti che le costituiscono, i processi di arretramento e di accumulo di sedimenti alla base. le definizioni adottate in questa parte fanno riferimento a quanto riportato da thorne (1998) ed in rinaldi & dapporto (2005). 8. vegetazione. si descrive la presenza o meno di vegetazione viva e/o di detriti legnosi sulle varie superfici precedentemente riconosciute. 9. opere. si riporta la presenza, tipo ed ubicazione di opere (interventi di stabilizzazione del fondo o delle sponde, argini, opere esterne all'alveo) nel tratto indagato. 9. note e commenti. sul fondo di ogni scheda è sempre riservato uno spazio per eventuali note e commenti, dove è possibile eventualmente indicare i codici delle foto e le relative coordinate gps. 3.2 variazioni morfologiche la quinta scheda relativa alle variazioni morfologiche ha come oggetto la descrizione e classificazione delle variazioni avvenute in una scala temporale dell'ordine degli ultimi 100-150 anni circa, vale a dire a partire 356 m. rinaldi da un'epoca in cui comincia ad essere disponibile una documentazione (ad esempio le prime levate delle tavolette igm) sulla base della quale si possono valutare le modifiche avvenute in maniera sufficientemente attendibile. 1. variazioni di larghezza. si fa riferimento a tre situazioni rappresentative: (a) xix secolo; (b) anni '50 del xx secolo; (c) ultimo volo aereo (o immagine satellitare) disponibile. si riportano le misure di variazione di larghezza rispetto alle due situazioni di riferimento (a) e (b). le misure possono essere effettuate precedentemente al rilevamento sul terreno, oppure possono essere fatte preliminarmente sul terreno (sulla base della documentazione richiesta) e poi perfezionate successivamente. ciò ha essenzialmente lo scopo di facilitare la comprensione delle superfici presenti sul terreno e delle variazioni avvenute. 2. variazioni tracciato. analogamente alla sezione precedente, in questo caso si descrivono le variazioni di morfologia planimetrica (caratteri di intrecciamento o sinuosità, barre, spostamenti laterali, morfologia complessiva dell'alveo) in maniera qualitativa (diminuito, invariato, aumentato) (eventuali misure dei parametri di interesse sono rinviate ad una fase di analisi successiva). 3. variazioni altimetriche. si indicano dapprima i dati eventualmente disponibili (rilievi topografici di profili e/o sezioni), sulla base dei quali si ricava una stima delle variazioni avvenute. nel caso, peraltro frequente, di assenza di dati, si ricorre ad evidenze sul terreno. nel caso di incisione, si effettua una valutazione dell'abbassamento complessivo del fondo sulla base della misura di dislivelli tra superfici omologhe (piana inondabile attuale e terrazzo oppure sommità della barra attuale e sommità dei depositi di barra riconosciuti in affioramento in corrispondenza di scarpate). tali determinazioni si devono avvalere di osservazioni fatte da foto aeree, che possano permettere di ricavare informazioni cronologiche certe sulle superfici rispetto alle quali si misurano i dislivelli. ad esempio, una superficie attuale di piana inondabile o di terrazzo può essere riconosciuta sulle foto aeree di un determinato anno come una barra: misurando in campo il dislivello tra sommità delle ghiaie lungo una scarpata di erosione di tale superficie e la sommità delle ghiaie delle barre attuali, è possibile ricavare una stima dell'abbassamento del letto rispetto a quel determinato anno. e' opportuno sottolineare che tali misure sono affette da un certo grado di incertezza e, per avere stime sufficientemente attendibili, è necessario effettuare più osservazioni in uno stesso tratto. sulla base dei dati disponibili e/o dei dati di campo, si giunge ad una classificazione delle variazioni altimetriche. infine, essendo molte di queste valutazioni interpretative e soggette ad un certo grado di incertezza, si richiede di esprimere un giudizio complessivo sul livello di confidenza. 3.3 tendenze attuali la sesta scheda relativa alle tendenze attuali ha come oggetto le variazioni in atto, facendo riferimento ad una scala temporale che abbraccia gli ultimi 10-15 anni circa. 1. tendenza larghezza. si fa riferimento agli ultimi due voli aerei disponibili (o eventualmente immagini satellitari ad alta risoluzione), sulla base dei quali si effettuano le misure di larghezza (con modalità analoghe alla scheda precedente) e quindi si stima la tendenza attuale (in restringimento, in equilibrio, in allargamento). tali misure possono essere eventualmente integrate da dati o evidenze sul terreno (sponde in avanzamento o in arretramento). 2. tendenza altimetrica. analogamente alla scheda delle variazioni, si fa riferimento inizialmente agli eventuali dati esistenti (due rilievi topografici relativi agli ultimi 10-15 anni), nel qual caso è possibile definire le variazioni di quota del fondo avvenute. sono inoltre definiti alcuni dati o evidenze valutabili dall'osservazione di immagini telerilevate (variazioni dell'indice di intrecciamento e/o delle dimensioni e numero delle barre), che forniscono informazioni indirette sulla possibi le tendenza attuale. successivamente si riporta una lista di dati o evidenze osservabili sul terreno. a tal fine, è stata effettuata una ricerca bibliografica (ad es. simon, 1995; simon & do w n s, 1995; fpcbc, 1996) per individuare quelle evidenze sul terreno che, anche secondo altri autori, potessero essere diagnostiche per l'interpretazione delle tendenze attuali. i dati e le evidenze selezionati sono ordinati su tre colonne, a seconda che indichino una tendenza all'incisione (colonna sinistra), all'equilibrio (colonna centrale) o alla sedimentazione (colonna a destra). inoltre sono divisi secondo tre categorie: (a) morfologia, (b) sedimenti, (c) vegetazione e detriti legnosi. tutti i dati o evidenze sul terreno (compresi quelli indiretti da foto aeree o immagini satellitari) sono identificati attraverso un codice (f1, m1, ecc.), sulla base del quale è possibile distinguere tra: (a) variabili diagnostiche (indicate con lettera maiuscola), vale a dire variabili di maggior peso, la cui presenza è fortemente indicativa di una tendenza; (b) variabili non diagnostiche (indicate con lettera minuscola), cioè evidenze che da sole non permetterebbero l'attribuzione ad una certa tendenza (in quanto non esclusivi di essa) ma che vanno a rinforzare le variabili diagnostiche, se presenti, della stessa tendenza. tali codici sono predisposti anche in funzione della definizione successiva di un indice di tendenza (si veda paragrafo successivo). analogamente alla scheda delle variazioni, è possibile riportare alcune misure di dislivelli tra superfici omologhe che possono fornire una stima di massima dell'entità della tendenza attuale. infatti, nei casi in cui si osserva la sommità delle ghiaie in scarpate di erosione che mettono in contatto l'alveo con una piana inondabile di recente formazione (ultimi 10 15 anni), è possibile raffrontare tale livello con la sommità delle barre attuali. nel caso in cui la sommità delle barre attuali è superiore rispetto alle ghiaie in affioramento lungo la scarpata, si può desumere che l'alveo ha una tendenza attuale all'aggradazione, e viceversa nel caso di incisione in atto. anche in questo caso, è opportuno abbinare tali interpretazioni sul terreno con osservazioni di foto aeree degli ultimi 10 15 anni ed effettuare più determinazioni in uno stesso tratto. il grado di incertezza di tali interpretazioni aumenta nel caso di alvei con morfologie a canali intrecciati, dove le altezze delle barre sono molto variabili. 357schede di rilevamento geomorfologico ... si riporta poi se e quando si è verificato (limitatamente agli ultimi 10 anni circa) un evento di piena di una certa intensità, in modo da tener presente che alcune evidenze potrebbero essere o meno condizionate da tale evento e non necessariamente essere indicative di una tendenza. infine, analogamente a quanto fatto per le variazioni, si classifica il tratto in funzione delle tendenze altimetriche, attribuendolo ad una delle tre classi (incisione, equilibrio, sedimentazione). l'attribuzione ad una certa tendenza altimetrica si basa sul fatto che tutte o la maggior parte delle evidenze sul terreno riconosciute (in particolar modo quelle considerate come diagnostiche) siano attribuite a tale tendenza. d'altra parte non è infrequente il caso in cui si possano avere nello stesso tratto indicatori di tendenze opposte (incisione e sedimentazione). ciò si può verificare soprattutto in alvei a morfologie complesse (w a n d e r i n g, canali intrecciati) e con numerose barre e canali, dove è molto frequente il caso in cui nello stesso tratto esistano zone in erosione e zone in sedimentazione, come messo in evidenza anche in recenti studi basati su analisi fotogrammetriche (si veda ad es. hicks et al., 2008). in questi casi, se non esiste una tendenza chiaramente prevalente sull'altra, il tratto si interpreta come in condizioni di equilibrio dinamico. 4. applicazioni e sviluppi successivi le schede di rilevamento geomorfologico di alvei fluviali qui proposte derivano dall'esigenza di caratterizzare un tratto di alveo ed interpretarne le variazioni passate e le tendenze attuali, attraverso un rilievo sul terreno integrato con altri tipi di dati (in particolare l'analisi delle foto aeree), allo stesso tempo cercando di semplificare la procedura proposta da thorne (1998). versioni precedenti delle schede qui proposte sono state già ampiamente impiegate sul f. tanaro, f. magra e f. vara (siviglia et al., 2004; rinaldi, 2005; 2007). la versione qui proposta è stata finora applicata a numerosi casi di studio rientranti nel progetto prin 2005 “dinamica recente ed attuale di alvei fluviali in italia centro-settentrionale: tendenze evolutive, cause ed implicazioni applicative”, quali f. panaro, f. cecina, f. piave, f. tagliamento, f. trebbia, f. orco e f. stura. si prevede, come sviluppi successivi, di abbinare a queste schede di base alcuni moduli integrativi relativi a possibili misure che preferibilmente andrebbero effettuate (rilievi topografici, misure granulometriche, misure dei detriti legnosi, ecc.). inoltre si prevede di ricavare un indice o una serie di indici, basati sulla somma delle variabili diagnostiche (quelle indicate con lettera maiuscola nella sesta scheda) e non diagnostiche (quelle indicate con lettera minuscola), che tengano conto di tutti gli indicatori rilevati e che esprima in maniera sintetica la tendenza attuale del fondo. le schede presentate non sono direttamente associate ad una particolare classificazione delle morfologie fluviali, in quanto si preferisce lasciare a chi le utilizza la scelta della classificazione che ritiene più adatta al suo caso di studio ed alle finalità del progetto. tuttavia, le informazioni contenute in queste schede sono sufficienti per l'applicazione di quasi tutti i sistemi di classificazione proposti in letteratura, incluso quello sviluppato da ro s g e n (1996). l'utilizzo delle schede permette una classificazione di: (a) variazioni della quota del fondo (inciso, invariato, aggradato) e della larghezza (ristretto, invariato, allargato); (b) tendenze attuali del fondo (in incisione, in equilibrio, in sedimentazione) e di larghezza (in restringimento, in equilibrio, in allargamento). combinando queste informazioni, è possibile sinteticamente descrivere le condizioni attuali del corso d'acqua come risultato delle variazioni passate e delle tendenze attuali, ed eventualmente attribuire il tratto studiato ad uno schema di classificazione basata sugli aggiustamenti morfologici (surian & rinaldi, 2003) o ad un modello generale di evoluzione. si vuole rimarcare che la metodologia di rilevamento geomorfologico qui descritta vuole rappresentare il punto di partenza, piuttosto che l'obiettivo ultimo, di uno studio delle condizioni di instabilità di un alveo fluviale e di eventuali previsioni delle tendenze evolutive future, che dovrebbe essere seguito da una fase successiva più analitica e di quantificazione dei processi, secondo quanto suggerito da simon et al. (2007). tale tipo di classificazione risulterebbe anche molto funzionale alle esigenze di classificazione e monitoraggio dei corsi d'acqua ai fini del recepimento della direttiva quadro acqua 2000/60, la quale richiede di classificare il fiume in base al suo discostamento rispetto ad un dato stato di riferimento. ringraziamenti ricerca finanziata dal miur nell'ambito del progetto prin 2005 “dinamica recente ed attuale di alvei fluviali in italia centro-settentrionale: tendenze evolutive, cause ed implicazioni applicative” (responsabile nazionale: n. surian, responsabile u.o. firenze: m. rinaldi). si ringraziano c. audisio, g. barbero, a. cisotto, g. doretti, g. duci, l. cibien, f. maraga, l. nardi, l. pellegrini, c. simoncini, n. surian, l.b. teruggi, o. turitto, p. vercesi e l. ziliani per i commenti ed i preziosi suggerimenti forniti durante il corso di svolgimento del progetto di ricerca. si ringraziano infine m. coltorti e a. fontana e n. surian per aver contribuito a migliorare l'articolo attraverso i loro commenti costruttivi. bibliografia br i c e j.c. (1984) planform properties of meandering r i v e r s in elliott c.m. (ed), river meandering, proc.conf.rivers'83, asce, new york, 1-15. bunte k. & abt s.r. (2001) sampling surface and subsurface particle-size distributions in wadable graveland cobble-bed streams for analyses in sediment transport, hydraulics, and streambed monit o r i n g u.s.department of agriculture, forest service, rocky mountain research station, general technical report rmrs-gtr-74, 428 pp. buffagni a., erba s. & ciampittiello m. (2005) il rilevamento idromorfologici e degli habitat fluviali nel contesto della direttiva europea sulle acque (wfd): principi e schede di applicazione del metodo caravaggio notiziario dei metodi analitici, 2, istituto di ricerca sulle acque, cnr irsa, 32-34. ca t a n i f., ri n a l d i m. & ro m i z i a. (1995) v a l u t a z i o n e 358 m. rinaldi della instabilità di alvei fluviali in corrispondenza di strutture di attraversamento atti ii incontro internazionale giovani ricercatori in geologia applicata, peveragno (cu), 11-13 ottobre 1995, 154-159. ch u r c h m.a. (1992) channel morphology and t y p o l o g y in: callow p.e petts g.e. (eds), the rivers handbook, oxford, blackwell. da p p o r t o s., ri n a l d i m., ca s a g l i n. & va n n o c c i p . (2003) mechanisms of riverbank failure along the arno river, central italy earth surface processes and landforms, 28 (12), 1303-1323. downs p.w. & thorne c.r. (1996) a geomorphological justification of river channel reconnaissance survey trans.inst.br.geogr., ns 21, 455-468. en v i r o n m e n t ag e n c y (1997) river habitat survey field survey guidance manual, 41 pp. en v i r o n m e n t ag e n c y (2003) river habitat survey in bri tain and ireland. fie ld survey guidance manual: 2003 version 136 pp. fo r e s t pr a c t i c e s code of british co l u m b i a (1996) channel assessment procedure guidebook, 37 pp. govi m. & surian n. (2003) una proposta di monitoraggio morfologico degli alvei fluviali c i n q u e fiumi, anno ii, n. 2 3, rivista dell'autorità di bacino dei fiumi isonzo tagliamento livenza piave brenta-bacchiglione, gangemi editore, venezia, 4-11. gurnell a., tockner k., edwards p. & petts g. (2005) effects of deposited wood on biocomplexity of river corridors front.ecol.environ., 3 (7), 377382. hicks d.m., duncan m.j., lane s.n., tal m. & westaway r. (2008) contemporary morphological change in braided gravel-bed rivers: new developments from field and laboratory studies, with particular reference to the influence of riparian vegetationin: habersack h., piégay h. e rinaldi m. (eds), gravel-bed rivers vi from process understanding to river restoration, elsevier, 557-586. hupp c.r. & osterkamp w.r. (1996) riparian vegetation and f luvial geomorphic processes geomorphology, 14, 277-295. hupp c.r. & rinaldi m. (2007) riparian vegetation patterns in relation to fluvial landforms and channel evolution along selected rivers of tuscany (central i t a l y ) annals of the association of american geographers, 97 (1), 12-30. ke l l e r h a l s r., ch u r c h m. & br a y d.i. (1976) classification and analysis of river processes j.hydraul.div., asce, 102, no.hy7. le o p o l d l.b., wo l m a n m.g. & mi l l e r j.p. (1964) fluvial processes in geomorphology freeman, s.francisco. mi l a n d.j., he r i t a g e g.l. & he t h e r i n g t o n d. (2007) application of a 3d laser scanner in the assessment of erosion and deposition volumes and channel change in a proglacial river earth surface processes and landforms, 32 (11), 16571674. mo n t g o m e r y d.r. & bu f f i n g t o n j.r. (1997) c h a n n e l reach morphology in mountain drainage basins geological society of america bulletin, 1 0 9 ( 5 ) , 596-611. osterkamp w. r. & hupp c. r. (1984) geomorphic and vegetative characteristics along three northern virginia streams geological society of america bulletin, 95,1093-1101. ra v e n p.j., ho l m e s n.t.h., da w s o n f.h., fo x p . j . a . , ev e r a r d m., fo z z a r d i.r. & ro u e n k.j. (1998) river habitat quality. the physical character of rivers and streams in the uk and isle of man river habitat survey report no. 2, 34 pp. rinaldi m. (2003) recent channel adjustments in alluvial rivers of tuscany, central italy earth surface processes and landforms, 28 (6), 587-608. rinaldi m. (2005) studio geomorfologico dei principali alvei fluviali nel bacino del fiume magra finalizzato alla definizione di linee guida di gestione dei sedimenti e della fascia di mobilità funzionale relazione finale convenzione di ricerca tra autorità di bacino del fiume magra e dipartimento di ingegneria civile, università di firenze, 160 pp. ri n a l d i m. (2007) approfondimenti dello studio geomorfologico dei principali alvei fluviali nel bacino del fiume magra finalizzato alla definizione di linee guida di gestione dei sedimenti e della fascia di mobi lità funzionale relazione finale convenzione di ricerca tra autorità di bacino del fiume magra e dipartimento di ingegneria civile e ambientale, università di firenze, 154 pp. ri n a l d i m. & casagli n. (1999) stability of streambanks formed in partially saturated soils and effects of negative pore water pressures: the sieve river (italy) geomorphology, 2 6 (4), 253277. rinaldi m. & dapporto s. (2005) monitoraggio e analisi dei processi di arretramento e dei meccanismi di instabilità di sponde fluviali in: brunelli m. & farabollini p. (eds), dinamica fluviale, atti giornate di studio sulla dinamica fluviale, grottammare, giugno 2002, ordine dei geologi marche, 165-201. ro s g e n d.l. (1996) applied river morphology wildland hydrology books, pagosa springs, colorado, 390 pp. rosgen d.l. (2001) a stream channel stability method o l o g y. proceedings of the seventh federal interagency sedimentation conference, reno, nevada, ii-18 ii-26. schumm s.a. (1977) the fluvial system wiley, new york, 338 pp. schumm s.a. (1985) patterns of alluvial rivers annual review of earth and planetary sciences, 13, 5-27. simon a. (1995) adjustment and recovery of unstable alluvial channels: identification and approaches for engineering management earth surface processes and landforms, 20, 611-628. si m o n a. & do w n s p.w. (1995) an interdisciplinary approach to evaluation of potential instability in alluvial channels geomorphology, 12, 215-232. simon a., outlaw g.s. & thomas r. (1989) evaluation, modelling, and mapping of potential bridge scour, west tennessee in: proc.national bridge scour symp., federal highway administration report fhwa-rd-90-035, 112-129. si m o n a., do y l e m., ko n d o l f m., sh i e l d s f.d. jr., rhoads b. & mcphiilips m. (2007) critical evalua359schede di rilevamento geomorfologico ... tion of how the rosgen classification and associated “natural channel design” methods fail to integrate and quantify fluvial processes and channel r e s p o n s e. journal of american water resources association, 43 (5), 1117-1131. si v i g l i a a., fe d e r i c i b., be c c h i i. & ri n a l d i m. (2004) sediment transport and morphodynamic of the tanaro river, north-western italy in: sediment transfer through the fluvial system, proceedings symposium held in moscow, august 2004, iahs publ.288, 308-315. surian n. & rinaldi m. (2003) morphological response to river engineering and management in alluvial channels in italy geomorphology, 50 (4), 307326. thorne c.r. (1997) channel types and morphological c l a s s i f i c a t i o n in: thorne c.r., hey r.d. e newson m.d. (eds), applied fluvial geomorphology for river engineering and management, john wiley & sons ltd., 175-222. th o r n e c.r. (1998) stream reconnaissance handbook. geomorphological investigation and analysis of river channels john wiley & sons ltd, chichester, england, 133 pp. th o r n e c.r. & ea s t o n k. (1994) g e o m o r p h o l o g i c a l reconnaissance of the river sence, leicestershire for r iver restorationthe east midland geographer, 17, 40-50. thorne c.r., reed s. & doornkamp j.c. (1996a) a procedure for assessing river bank erosion problems and solutionsnational rivers authoruty, r&d report 28, 48 pp. th o r n e c.r., al l e n r. & si m o n a. (1996b) geomorphological river channel reconnaissance for river analysis, engineering and management transactions of the institute of brit ish geographers, ns 21, 469-483. wi l l i a m s g.p. (1978) bank-full discharge of rivers water resources research, 14 (6), 1141-1154. 360 ms. ricevuto il 6 dicembre 2007 testo definitivo ricevuto il 29 aprile 2008 ms. received: december 6, 2007 final text received:april 29, 2008 m. rinaldi 361schede di rilevamento geomorfologico ... 362 m. rinaldi 363schede di rilevamento geomorfologico ... 364 m. rinaldi 365schede di rilevamento geomorfologico ... 366 m. rinaldi imp.cardara& geomorphological changes due to human actions at coppa nevigata (tavoliere di puglia, southern italy) reconstructed through core analyses massimo caldara1, ilena caroli2 & oronzo simone1 1dipartimento di geologia e geofisica, sezione di geografia fisica e geomorfologia – università degli studi di bari, campus universitario, via orabona 4, 70125 bari, italia; 2dottorato di ricerca in geomorfologia e dinamica ambientale – università degli studi di bari correspondence should be addressed to massimo caldara: caldara@geo.uniba.it abstract: m. caldara et al., geomorphological changes due to human actions at coppa nevigata (tavoliere di puglia, southern italy) reconstructed through core analyses. it issn 0394-3356, 2004 the area surrounding the coppa nevigata settlement is one of the best places for the reconstruction of the relationship between human activities and the environment since the first tavoliere di puglia population phases. the settlement is the best studied in the tavoliere plain, it is situated between the foot of the gargano headland and the inner shore of the ancient salpi lagoon, in a very sensitive area from the environmental point of view. previous studies highlighted the environment evolution and its chronology. the close relationship between the wet area facing the settlement and the population pattern in some cases was documented. the preliminary study of six new cores and considerations made on three previously drilled successions are the base of this research. the studied successions were grouped in three transects and described in function of their distance from the settlement. these are the a (distal), b (in the middle) and the c (proximal) transects. there were recognized eight different phases attributable to two different evolutionary patterns. the environments set under or modified by intentional anthropic action, such as the b (terrestrial phase i), d (terrestrial phase ii) and h (historical reclamation) phases, have to be ascribed to the first one. the almost "natural" phases belong to the second one, even if the accumulated material is often related to human actions. these are the phases a (natural phase i), c (natural phase ii), e (natural phase iii), f (arid terrestrial phase) and g (natural phase iv). the b and d anthropic phases have been recognized beneath the ground surface up to about 90 m far from the nearest exploration ditches dug by archaeologists on the side of the coppa nevigata knoll. we were not able to put a boundary between these two phases within the c transect cores, but they are well defined in the a transect. the anthropic phase b corresponds to an urbanization phase that seems to have been started from the most internal settlement areas through the artificial compaction/leveling of marshy/lagoonal deposits, whereas the presence of hearths in distal areas could be attributed to activities carried out outside the defensive wall system. the anthropogenic d phase shows, in the area next to the hillock side, the presence of simple inhabitation structures that lasted for a relatively long time, as testified by numerous tramped and/or leveled surfaces (simple or superimposed) associated to concotto levels and hearths. on the other hand in distal areas the d phase seems to be characterized by an agricultural/pastoral land use. the h phase sediments have locally accumulated under nearly natural conditions, even if they are directly related to reclamation works made during the last two centuries. in conclusion, through time man modified and shaped the environment around the coppa nevigata knoll, in particular during the middle bronze age (b phase), the iron age (d phase) and during the last two centuries (h phase). sometimes the sedimentation processes under natural conditions were also strongly influenced by man, as suggested by the presence of the organic deposits accumulated during the a phase or by the c phase sediments. riassunto: m. caldara et al., variazioni dell’ambiente geomorfologico indotte dall’uomo desunte dallo studio di carotaggi a coppa nevigata (tavoliere di puglia). it issn 0394-3356, 2004 l’area a ridosso dell’insediamento preistorico di coppa nevigata è quella che meglio si presta per la ricostruzione dei rapporti intercorsi tra l’uomo e l’ambiente a partire dalle prime fasi di popolamento del tavoliere di puglia. difatti, questo insediamento è certo quello più studiato del tavoliere ed inoltre era collocato ai piedi del promontorio del gargano sul margine interno dell’antica laguna di salpi, in un’area ad alta sensibilità ambientale, in quanto soggetta alle rapide modificazioni dovute alla combinazione di processi diversi (fluviale, marino, eolico ecc.) e all'opera dell'uomo. studi precedenti degli autori hanno delineato l’evoluzione degli ambienti e la loro collocazione cronologica. inoltre, in alcuni casi hanno messo in evidenza la stretta correlazione fra l’area umida antistante l’abitato di coppa nevigata e le modalità di vita e di sviluppo dell’insediamento. lo studio preliminare di sei nuove perforazioni, realizzate ad hoc a ridosso della collina di coppa nevigata, unito ad altre tre fatte precedentemente, è alla base del presente lavoro. le successioni sono state riunite in tre gruppi e descritte in funzione della loro distanza dall’insediamento (transetto a, distale; transetto b, intermedio e transetto c, a ridosso della collina di coppa nevigata). sono state riconosciute otto diverse fasi riconducibili grosso modo a due differenti modelli evolutivi. al primo appartengono gli ambienti originatisi o rimodellati intenzionalmente dall’uomo: fasi b (fase continentale i), d (fase continentale ii), e h (colmate storiche). al secondo appartengono gli ambienti dove il meccanismo di accumulo dei sedimenti è naturale, anche se molte volte i materiali accumulatisi sono riconducibili alle attività dell’uomo: fasi a (fase naturale i), c (fase naturale ii), e (fase naturale iii), f (fase continentale arida) e g (fase naturale iv). le fasi antropiche b e d che non si riescono a differenziare nelle successioni del gruppo c, quelle a ridosso dell’insediamento, e che sono ben separate nelle successioni del gruppo a, si ritrovano fino a circa 90 metri dai più vicini saggi archeologici. la fase antropica b corrisponde ad una fase di urbanizzazione che sembra procedere a partire dalle aree più prossime all’insediamento compattando i depositi palustri e/o lagunari con battuti, mentre nelle aree più lontane l’attività, limitata a soli focolari, sembra quella svolta all’esterno delle mura. la fase antropica d mostra, nell’area a ridosso della collina di coppa nevigata, la presenza, più o meno continua nel tempo, di strutture abitative semplici (abbondanza di battuti singoli e/o sovrapposti uniti a livelli di concotto e a focolari), mentre per le aree distali mostra una utilizzazione di tipo agricolo-pastorale. la fase antropica h è riconducibile alle colmate storiche degli ultimi secoli. si tratta di un deposito realizzato con intenzionalità dall’uomo anche se i meccanismi di sedimentazione sono praticamente naturali. in definitiva nell’area di coppa nevigata l’uomo ha rimodellato e modificato il paesaggio più volte, durante il bronzo medio (fase b), l’età del ferro (fase d) e negli ultimi due secoli (fase h). comunque è stato fortemente attivo condizionando la sedimentazione anche nella fase a con depositi organici, e nella fase c. keywords: buried morphology, geoarchaeology, tavoliere di puglia, holocene. parole chiave: morfologie sepolte, geoarcheologia, tavoliere di puglia, olocene. il quaternario italian journal of quaternary sciences 17(2/2), 2004, 495-508 496 m. caldara, i. caroli & o. simone 1. introduction the coppa nevigata settlement is one of the best known archaeological sites in the apulian region. it is located at 41°33’26”n, 15°50’00”e, some five kilometres from the modern coast, between the gargano promontory and the tavoliere plain. the site was situated on the inner shore of the holocene salpi lagoon (boenzi et al., 2001), a coastal waterbody extended from south of manfredonia to the ofanto river delta and now totally disappeared because of both natural infilling and land reclamation works (boenzi et al., in press; caldara et al., 2002b). the archaeological site is known since the first years of the xx century (mosso, 1909). nevertheless, it was subjected to systematic archaeological explorations only from the '50s of last century (puglisi, 1955; 1975; 1982). the investigations started again in 1983 with extensive excavations still in progress (cazzella & moscoloni, 1988; 1990; cazzella et al., 2001). the archaeological research evidenced a complex stratigraphy spanning from the early neolithic, throughout the bronze age and into the iron age (cazzella, 1996; cazzella & moscoloni, 1999). during the various inhabitation phases the mode of occupation changed (caldara et al., 2003a). since the '90s the authors have been investigating the coastal plain of the tavoliere, but the choice to focalise the multidisciplinary efforts in a sample area occurred only later. the coppa nevigata settlement offered good research possibilities, since the good knowledge acquired through decades of archaeological study as well as its location in a high sensitive environmental frame. the best available information suggests that the population around the lagoonal area increased and decreased several times. one explanation of this is past changes in the regional environmental conditions (boenzi et al., 2001; caldara et al., 2002b). in 1997 five cores were drilled (cn1 to cn5) at various distances from the settlement (fig. 1). the fig. 1 location of the studied areas. cnn = coring site. ubicazione dell’area. cnn = posizione dei sondaggi. study of two of the nearest cores to the site (cn2 and cn5) is by now complete (caldara et al. 1999; 2001; 2003b; in press c), while the most distant ones (cn3 and cn4) are still under examination (simone 2003; caldara et al., in press c). the first results obtained were the reconstruction of the environment evolution close to the site (caldara et al., 1999; 2001) and the understanding of chronology of the events (caldara et al., 2003a). the idea at the base of our research were that there was a close relationship between the wet area facing the coppa nevigata knoll and the way in which the settlement developed (caldara et al., 2002a). this connection has been documented in various cases. as an example, at the site were found ceramic artifacts, dating back between the proto-apennine and the subapennine periods, containing tephra (levi et al. 1999). the use of pyroclastic material as a tempering ingredient to make ceramics was possible by the presence of this kind of sediments in the lagoon bottom (caldara et al., 2001). an other example is the use of the cockle cerastoderma glaucum as a food resource, in particular during the neolithic and the bronze age (late subapennine), as documented by minniti (1999). as the study progressed we realized that, especially during the middle bronze age, man influenced the local environment evolution (caldara & simone 2003; in press), as attested by the presence of deposits directly related to anthropogenic activities only within the cores nearest to the settlement. the aim of this research is to asses how strong was the impact of human actions on the surrounding environment. one of the possible ways to reach this goal was the detailed reconstruction of the geometries of buried sedimentary bodies (both of natural and anthropic origin). to verify our hypotheses, six new cores were drilled in 2002 (cn11 to cn16). the coring locations were accurately decided on a detailed map (fig. 1), in order to get a good distribution of samples. thus, at the base of this paper are the preliminary results of the study of the six new cores plus the cn1, compared and integrated with data obtained by the analysis of cn2 and cn5 successions. 2. geological and morphological setting the coppa nevigata knoll is situated along the south-east transition area (fig. 2) between the smooth limestone surface of the southern gargano terraces area, called "pedegargano" by caldara & palmentola (1991), and the alluvial coastal plain of the tavoliere di puglia (southern italy). the gargano is a calcareous massif, part of the mesozoic apulia platform. the outcropping rocks in the southern area of the headland are the oolithic, pseudooolithic, detrit ic and micrit ic l imestone of the portlandian, "calcari oolitici di coppa guardiola" formation (luperto sinni & masse, 1986). in particular, the lower terrace at the foot of the headland, dips gently eastward starting from elevations slightly above 100 meters a.s.l.. the sub-horizontal surface, in correspondence of the terminal section of the candelaro stream, has been divided in several minor block by nw-se faults. 497geomorphological changes ... the tavoliere plain subsoil is made of a thick succession of quaternary terrigenous sediments overlaying the bradanic cycle deposits, in particular the "argille subappennine" formation. starting from the end of the lower pleistocene, due to some stands of the regional uplift combined with glacio-eustatic movements, the tavoliere landscape was shaped in a number of marine terraces gently sloping down towards the sea. some of them are now covered by broad alluvial deposits (caldara & pennetta, 1993a). during the last glacial phase, because of the lower sea level, the tavoliere coastland was deeply incised by rivers flowing from the apennine chain (caldara & pennetta, 1996; caldara et al., 2002b). at the end of the last glacial phase, the eastern margin of the tavoliere took the characters of a submergence alluvial plain coast. as the sea level raised, several lagoons set on the margin of the submerging plain. time after time, the eastern area of the tavoliere was then characterized by a variety of transitional environments, such as dune belts, lagoons, swamps and a broad alluvial coastal plain. in correspondence of the breaks of slope between the gargano and the pedegargano areas and between the pedegargano and the tavoliere plain, in particular at the mouths of the streams flowing down the headland, a number of alluvial fans developed during low sea level periods. these are broad sedimentary bodies made of limestone breccias whose rounded elements are well cemented in a calcareous matrix (boenzi & caldara, 1999). during the middle-late holocene a broad coastal lake set up, the salpi lagoon (caldara et al., 2002b). through its history, this lagoon underwent many changes in its shape and extent. nearly at the end of its existence, the coastal waterbody became a marshy and unhealthy land. recently, in particular during the last two centuries, the coastal plain was subjected to reclamation. in fact, several streams have been diverted in order to facilitate the infilling of coastal depressions, such as the versentino and salso lakes. as a result, the alluvial sediments covered and concealed all the features that characterized the coastal plain, including the deposits of lagoon-sabkha environments (studied by caldara & pennetta, 1993b and boenzi et al., 2001), the dune belt that separated it from the sea (schmiedt, 1973) and the historical lake deposits. nowadays an enclave of the ancient lagoon exists, this is the palude frattarolo (caldara et al., 1994), a broad coastal swamp situated south of manfredonia, between the coppa nevigata knoll and the coastline. 3. results acquired since former works so far in the coppa nevigata area four cores were studied (caldara et al., 1999; 2001; 2003b; in press c; simone 2003). two of those, the cn2 and cn5, were drilled in vicinity of the archaeological site, next to the lagoon shore. the other two bore holes, cn4 and cn3, were respectively made at 0.4 km and 0.8 km far from the settlement, towards the middle of the basin. the drillings at the foot of the settlement went across to sediments accumulated between before 3600 yr bp ("avellino eruption" tephra) and recent times. a stop in 498 m. caldara, i. caroli & o. simone fi g 2 s ch em at ic g eo m or p ho lo gi ca l m ap . k ey t o sy m b ol s: 1 = li m es to ne d ep os its ( m es oz oi c) , p lio -p le is to ce ne c al ca re ni te a nd q ua te rn ar y sl op e d ep os its ; 2 = t av ol ie re d i p ug lia t er ra ce d d ep os its (m ar in e an d fl uv ia l); 3 = p re se nt d ay s an d ; 4 = h ol oc en e al lu vi al d ep os its ; 5 = h is to ric al r ec la m at io n se d im en ts ; 6 = a llu vi al fa n; 7 = b ur ie d d un e b el ts ; 8 = d ol in e; 9 = e sc ar p m en t d ue to m ar in e ab ra si on ; 1 0 = es ca rp m en t d ue t o flu vi al e ro si on ; 1 1 = " v " sh ap ed f lu vi al v al le y; 1 2 = f la t b ot to m ed f lu vi al v al le y; 1 3 = f os si l d ra in ag e, p al ae oriv er b ed ; 1 4 = d ra in ag e d itc h (r ea liz ed to r ec la im a n ar ea b y d ra in ag e) ; 1 5 = r oa d ; 1 6 = r ai lro ad . c ar ta g eo m or fo lo gi ca s ch em at ic a. l eg en d a: 1 = d ep os iti c ar b on at ic i m es oz oi ci , ca lc ar en iti p lio -p le is to ce ni ch e e d ep os iti d i ve rs an te q ua te rn ar i; 2 = d ep os iti t er ra zz at i m ar in i e flu vi al i d el ta vo lie re d i p ug lia ; 3 = sa b b ie a tt ua li; 4 = a llu vi on i o lo ce ni ch e; 5 = co lm at e st or ic he ; 6 = c on oi d e al lu vi on al e; 7 = c or d on i d un ar i s ep ol ti; 8 = d ol in a; 9 = s ca rp at a d i a b ra si on e m ar in a; 1 0 = s ca rp at a d i e ro si on e flu vi al e; 1 1 = in ci si on e a v ; 1 2 = in ci si on e co n fo nd o p ia tt o; 1 3 = d re na gg io fo ss ile , p al eo al ve o; 1 4 = c an al e d i b on ifi ca ; 1 5 = s tr ad a; 1 6 = fe rr ov ia . 499 deposition, highlighted by an erosive surface, occurred between the conventional 14c ages 2870±40 bp and 370±50 bp. in the middle of the basin (cn3 succession), at the bottom of the core, sediments have an age of 5580±40 yr bp. a hiatus is recorded between the conventional ages 3110±50 bp and 140±40 yr bp (caldara & simone, in press). materials found within the successions close to the settlement suggest the existence of a stable community in the nearby, particularly during the bronze age (caldara et al., 1999; 2001; 2003b). the cn2 and cn5 series show upcore alternating terrestrial and brackish horizons. one could interpret this alternation as the expression of four negative sea level fluctuations, marked by the deposition of terrestrial/marshy sediments (caldara & simone, in press). on the other hand, no evidence of sea level fluctuations were found in the middle of the basin (simone, 2003; caldara et al., in press c). according to caldara & simone (in press), three of the four fluctuations recognized in vicinity of coppa nevigata were most likely due to colonization of environments situated at the margin of the wet area, that is to say that the terrestrial/marshy environments should be considered as the expression of an aggrading coastline (whatever the cause) rather than a sea level fall. the analysis of the cn2 and cn5 cores made possible the reconstruction of palaeoenvironmental changes occurred in the nearby of the coppa nevigata settlement at least from 3600 years bp. on the basis of the fossiliferous assemblages, a descriptive name was given to each reconstructed environment (fig. 3). these, listed starting from the most ancient, are: 3.1. hydrobiidae spp. and cerastoderma lagoon mainly represented by clayey sediments, dominated by lagoon species, a few marine taxa occur in the lower section (caldara et al., 1999, 2001). during this first lagoon phase, two episodes conditioned the accumulation processes. the first event was the accumulation of a tephra layer containing materials from at least two different eruptions (caldara et al., 2001; 2003a). one of these has been identified as the "avellino eruption" of the vesuvius, dated at about 3500 ÷ 3600 bp (terrasi et al., 1999; albore livadie et al., 1998; rolandi et al., 1993; andronico et al., 1995). the rest of the tephra granules could be referred to one of the eruptions occurred during the last phase (4100 ÷ 3700 yr bp) of the phlegrean fields activity (caldara et al., 2001; 2003a). the second episode characterized the upper part of the hydrobiidae spp. and cerastoderma lagoon. at this level accumulated a horizon characterized by a high organic matter content, whose principal constituents are related to human activities, such as charred seeds and fruits, cereal remains, domestic animal bones, remains of insects living in granaries or breeding in decomposing meat and pottery fragments. given the excellent preservation state, we can say that these materials underwent a short transportation before the definitive deposition (caldara et al., 1999; 2001; 2003a). the accumulation of lagoon sediments continued until shortly after the radiocarbon date 3090±40 bp (cn5 core). 3.2. terrestrial phase i the successions continue upcore with sediments accumulated under sub-aerial conditions. the first centimetres are rich in organic matter and have a similar aspect in comparison to the ones above defined. the rest of the sub-aerial horizon is a soil made of siltyclayey sediment. the findings of pottery fragments, stones and concotto suggest that the settlement expanded towards the plain. according to the chronological data available, these structures were built after the radiometric date 3000±80 years bp and before 2870±40 bp (caldara et al., 1999; 2001; 2003a). 3.3. cerastoderma lagoon the terrestrial deposits are overlaid by grey clayey silts. the fauna, characterized by a low diversity, is dominated by cerastoderma glaucum (caldara et al., 2001; 2003a). 3.4. salt marsh i gradually, the lagoon environment evolved to a brackish marshy area. the lower part of this interval is characterized by clayey silts with thin arenaceous beds, whereas in the upper part there are calcareous lumps and thin black levels made of organic matter. this environment was described as a salt marsh (caldara et al., 2001; 2003a). 3.5. hydrobiidae spp. and abra segmentum lagoon the sediments that constitute this third lagoon episode are clayey silts with pebbles in its lower part, silts with thin black organic matter levels and calcareous lumps in the upper part. the macrofauna is represented mostly by lagoon taxa. progressively the environment underwent a relative lowering of the water level. 3.6. terrestrial phase ii this is a new terrestrial phase whose sediments are clayey silts dark-grey in color, with several thin organic matter levels and small calcareous lumps. the fauna is characterized by a mixed assemblage made of broken terrestrial mollusc shells and young individuals of lagoon species. 3.7. salt marsh ii this environment is represented by dark gray clayey silts with alternating calcareous levels. the mollusc fauna is poor and dominated by hydrobiidae, few young individuals of cerastoderma glaucum and abra segmentum also occur. 3.8. arid or semiarid terrestrial phase it is not clear yet when the salt marsh sediments stop to accumulate. in fact, these are cut by an erosive surface. a sub-aerial period, under arid or sub arid conditions, is testified by the formation of calcareous crust levels and lumps. 3.9. bithynia leachi and ovatella myosotis wetland shortly before the radiocarbon date 370±50 bp, the area at the foot of the coppa nevigata hillock was submerged by fresh water. the sediments accumulated in this interval are sandy silts rich of ovatella myosotis and bithynia leachi. geomorphological changes ... 500 m. caldara, i. caroli & o. simone fi g. 3 s tr at ig ra p hi c co rr el at io ns a m on g th e st ud ie d c or es . t he a , b , a nd c tr an se ct s ar e p ar al le l, w hi le t he d a lig nm en t is p er p en d ic ul ar t o th e fir st o ne s. b es id e th e tr an se ct s, t he a h le tte rs r ef er t o th e re co gn iz ed p ha se s, w hi le t he t er m in ol og y us ed is t he s am e as in li te ra tu re . c or re la zi on i s tr at ig ra fic he . s on o d is eg na ti i t ra ns et ti a ,b ,c p ar al le li fr a lo ro e d p er p en d ic ol ar e. s on o rip or ta ti a fia nc o d ei t ra ns et ti le le tt er e a -h rif er ite a lle f as i d a nc he la t er m in ol og ia d eg li am b ie nt i c om e d ef in ita in le tt er at ur a. 3.10. terrestrial phase iii the very upper part of the cn2 and cn5 cores is made of silty-clayey soil, densely laminated and scarcely pedogenized. the faunistic content, mostly terrestrial shell fragments, is scarce. 4. description of the studied successions for convenience the successions were grouped in three transects and described in function of their distance from the settlement. in particular, in the a group there are three successions drilled at the foot of the coppa nevigata knoll; the c group consists of four series sampled close to the settlement; in the b transect there are only two cores drilled in the middle between the a and c groups (fig. 1). 4.1. a transect cn13, cn2 and cn5 cores these three cores show a great lithological variability (fig. 3), due to the thick alternation of deposits accumulated in natural conditions or under the more or less direct anthropic influence. the environments formerly reconstructed for the cn2 and cn5 cores show a good mutual correspondence (caldara et al., 1999; 2001). on the other hand, only the lower and higher sections of the cn13 core could be correlated in a satisfactory way with the homologue environments reconstructed for the cn2 and cn5 cores. at the bottom, the cn2 and cn5 cores show lagoon deposits, mostly clayey (hydrobiidae and cerastoderma lagoon; caldara et al., 1999; 2001; 2003a; in press a). between 4.05 m and 3.60 m below m.s.l. (cn2 core) the accumulation of tephra deposits occurred (caldara et al., 2001; 2003a). in both the cn2 and cn5 cores the upper section of the hydrobiidae and cerastoderma lagoon and the lower part of the overlaying terrestrial sediments are characterized by the accumulation of an organic sediment, dark in colour, mainly made of heterogeneous material originated after the activities carried out at the settlement during the bronze age (caldara et al., 2001; 2003a; in press a). in the cn13 core the accumulation of this kind of sediments started under brackish conditions and continued in a paludal environment dominated by fresh water molluscs. the series continue upcore with terrestrial deposits (terrestrial phase i; caldara et al., 2003a). these sediment are clayey to sandy, grey or reddish-grey, with small calcareous lumps, calcareous crust fragments, pottery fragments and broken domestic animal bones (ox, pig, sheep, dog etc.). in the cn13 core, between 1.49 m and 1.29 m below m.s.l., there is a thin black horizon made of tiny charcoals. another charcoal level, about one centimetre thick, lies under a leveled surface1. concotto fragments, limestone and sandstone clasts have been found at several levels within the cn2 and cn5 successions. these findings were attributed to the remnants of a wall structure (caldara et al., 1999; 2001; 2003a; in press a). in the following section, up to the present day sea level, the sedimentation around the three bore holes occurred under different conditions. in particular, the sediment in the cn2 and cn5 successions is a lagoon clayey silt (cerastoderma lagoon, cn2 core, caldara et al., 2001; hydrobiidae lagoon, cn5 core, caldara et al., 1999). upcore the lagoon evolved to a more superficial environment in which accumulated clayey silt rich in organic matter characterized by young individuals of brackish taxa (salt marsh i in caldara et al., 1999; 2001; 2003a). the upper part of this section is again represented by lagoon clayey silt (cn2 core). the assemblages are dominated by lagoon taxa, the other accompanying species belong to the marine domain (hydrobiidae and abra lagoon in caldara et al., 1999; 2001; 2003a). on the other hand, the corresponding section of the cn13 core is characterized by sediments virtually similar to the ones that lay directly below, i.e. dark silt with dispersed calcareous crust fragments, charcoals and pottery fragments. between 0 m and 0.40 m circa above m.s.l. the successions recorded a new terrestrial phase (terrestrial phase ii, caldara et al., 2003a), with the accumulation of clayey to sandy silt. several organic levels and dispersed small calcareous lumps also occur. the assemblages are made of terrestrial mollusc fragments and young individuals of brackish taxa. some domestic and wild animal bones also occur (caldara et al., 1999; 2001). burnt bone fragments and marine gastropods have been found within thin dark levels in the cn2 core. the successions continue upcore with dark grey silt accumulated in brackish-marshy environments (salt marsh ii, caldara et al., 1999; 2001; 2003a). the fossil association is made of scarce brackish molluscs, foraminifers and ostracods. these sediments are cut by an erosive surface, marked in the cn2 and cn5 cores by a thick accumulation of a secondary calcareous crust, originated by groundwater evaporation. on the erosive surface lays a sandy silt deposit with fresh water fauna. the reconstructed environment is a marshland characterized by a variable fresh water covering (bithynia and ovatella wetland, cn2 core; bithynia wetland and ovatella wetland, cn5 core. caldara et al., 1999; 2001; 2003a). the very upper part of these three sequences is made of soil disturbed by the intense ploughing activities (terrestrial phase iii, caldara et al., 2003a). 4.2. b transect cn11 and cn1 cores in this group there are only two cores (cn11 and cn1, fig. 3). despite the care taken during coring activities, there have been two metres of sample loss in the cn1 core. thus we were able to correlate these successions only in a partial way. further data should be collected with additional cores. the lower part of the cn1 succession, is a greygreenish clayey sediment, somewhere sandy. there are scattered charcoals, calcareous crust fragments and domestic animal bones (sheep). between 2.50 and 2.00 501geomorphological changes ... 1 with "leveled surface" we mean a surface made regular by spreading of fine sediment, whatever it is (generally calcareous or clayey). the use to spread material in order to regularize the ground is well known to the archaeologists that worked on the coppa nevigata site. m below m.s.l. the sediment is dark, compressible and rich in vegetal detritus. in the whole this deposit is quite similar to the high organic deposit found in the cn2 and cn5 cores (caldara et al., 2003a). from the base of the cn11 core and above the two metres gap in the cn1, the two drillings went across to fine sediments, mostly clayey, greyish to dark, hardly stratified, deposited under the direct anthropic influence (scattered bone fragments, charcoals, bronze age pottery fragments). in three occasions the core sediments differ from the general pattern above described. in particular, at the bottom of the cn11 core, there is a rudite horizon made of heterogeneous materials, such as lithic fragments (limestone crust and siliceous pebbles), bones, pottery, terrestrial molluscs and charcoals. in the cn1 core, at circa 0.30 m above m.s.l., there is a reddish concotto horizon six centimetres thick. finally, in the cn11 core, at 0.70 m above m.s.l., a horizon made of calcareous crust fragments suggests the presence of a probable leveled surface. the two successions continue with a brown clayey soil with small lithic fragments. the upper part of this soil is deeply disturbed by ploughing. 4.3. c transect cn12, cn14, cn15 and cn16 cores in this group there are the successions drilled close to the settlement. the lower part of the sequence accumulated under mostly natural environments (lagoon, salt marsh and fresh marsh), the upper part is made of sediments deposited under the more or less direct anthropic influence. the cn16 core is the only one that reached the limestone substrate in this area. the transgression surface, cut on cretaceous limestone, is marked by holes made by marine molluscs and sponges and covered by a thin calcareous sand with marine shell fragments (ostrea, mytilus and pinna). rapidly, the assemblage becomes typically lagoonal (cerastoderma glaucum, abra segmentum, cyclope neritea and ammonia beccarii and haynesina germanica). the same fauna characterizes the overlaying clayey deposit. we considered natural the sediments accumulated at the base of the cn12 core (up to 1.22 m below m.s.l.). in particular, between the base and 1.66 below m.s.l., the sediments are silty with tiny vertical roots and characterized by lagoon taxa (abra segmentum, hydrobiidae, haynesina germanica and ammonia beccari). in the middle part of this section there are three volcanoclastic horizons (fig. 4d). the first one, the thicker, has a fairly regular base, whilst the contact between the other two and the sediment below is less evident. between the horizons with tephra some volcanic granules occur scattered within the sediment. the faunistic assemblages indicate a lagoon environment. between 1.40 and 1.22 m below the m.s.l. the sediment is silty-sandy. the collected fauna (mostly ovatella myosotis and truncatella subcylindrica) suggests a salt marsh environment with some fresh water input (occurrence of bithynia leachi). at the bottom of cn14 succession (fig. 4a) there is a yellowish sand level with cerastoderma glaucum, abra segmentum and hydrobiidae; several bithynia leachi also occur. a sharp contact separates the sand from a greyish clay layer accumulated in an almost natural environment. the clayey unit could be subdivided in three horizons. the lower and the upper ones are characterized by a thick lamination due to the presence of organic detritus (fig. 4e). the central part is made of massive clay with subvertical tiny roots. faunal assemblage is dominated by brackish organisms: ovatella myosotis and truncatella subcylindrica, some miliolids (quinqueloculina spp.). we interpreted this environment as a salt marsh. the natural deposit at the lower end of the cn15 succession is a silty sand made mostly by tephra granules mixed to lagoon molluscs (hydrobiidae and abra segmentum), foraminifers and ostracods. the upper part of the natural deposit is represented by a fine greygreenish sediment, slightly sandy, with fragments of reworked molluscs, perhaps accumulated in a marshy environment. the rest of the sequence accumulated under the more or less direct anthropic influence. in all the cores the contact between natural and anthropogenic sediments is sharp and occurs at similar elevations in the cn12, cn14 and cn15 series, while it is deeper in the cn16 core. the anthropogenic sediments are porous, dark grey, with scattered bronze age pottery fragments, concotto, lithic tools, domestic animal bones (sometimes burnt), marine shells (phyllonotus trunculus) and charcoals. the bedding planes are hardly visible, except when the drillings went across to black hearth material, concotto levels, tramping and/or leveled surfaces and structures in use for a considerable time span (fig. 4a). a number of leveled surfaces have been found in all the drillings in this group. these are well evident in the cn12, cn14 and cn15 cores, because realized with materials very different (in colour and nature) from the rest of core sediments. in some cases the surfaces were leveled by spreading a fine yellowish calcareous sediment, originated from the weathering of the mesozoic limestone that outcrop in the nearby area (fig. 4c). in other cases the material spread to create a plain surface is a clayey sediment with high carbonates content. several tramping surfaces lay around the same elevation. the deeper surface lays at 1.06 m below m.s.l. in the cn14 and cn15 cores (fig. 4f). there is, in the same two cores, another yellowish surface at 0.19 m above m.s.l., while in the cn12 and cn15 series, drilled at a greater distance, a leveled surface lays around 1.5 m above present day sea level. the upper part of the cn12 core (between 1.44 and 2.08 m above m.s.l.) and the middle of the cn14 core (between 0.17 and 0.49 m above m.s.l.) are characterized by two horizons with many superimposed thin levels, made of alternating fine yellowish and greyish sediments, charcoal levels, brown soil, concotto etc. (fig. 4b). we think that at those horizons the cores went across to structures in use for a long time span (e.g., a hut). on the other hand, in the cn16 core the leveled surfaces seem to have been realized with a different technique. in fact, these are just a few centimetres thick and realized with limestone, calcarenite, siliceous pebbles and calcareous crust fragments. the upper part of the cn12, cn14 and cn16 continue with a brown clayey soil with small lithic fragments deeply disturbed by ploughing. 502 m. caldara, i. caroli & o. simone 503geomorphological changes ... fig. 4 cn 14 core (a) and close ups of some cores (b-f): b = cn14 core, d phase, alternation of yellow and grey sediments used to level the ground, red concotto levels and black burnt hearth grounds; c = cn12 core, d phase, two beds, yellow and grey, of material spread to level the ground; d = cn12 core, a phase, silt with tiny vertical roots, lagoon taxa and volcanoclastic horizon; e = cn14 core, a phase; from the bottom: yellowish sand with lagoon fauna, thick lamination due to the presence of organic detritus and greyish clay (salt marsh); f = cn15 core, b phase, grey sediment spread to level the ground and a black horizon of burnt vegetal remains. except for the cn1, cn2 and cn5 cores, got by an hydraulic corer, all the other cores (among which the ones above) were obtained by a percussion drilling machine. carotaggio cn 14 (a) e particolari di alcune carote (b-f): b = cn14 perforazione, fase d, alternanza di piani battuti gialli e grigi, con livelli rossi di concotto e neri di suoli bruciati; c = perforazione cn12, fase d, due battuti giallo e grigio; d = perforazione cn12, fase a, limi con sottili radici verticali sormontati da un orizzonte vulcanoclastico caratterizzati da faune lagunari; e = perforazione cn14, fase a, sabbie giallastre con fauna lagunare sormontate da argille sottilmente laminate ricche di sostanza organica che passano ad argille grigie massicce con tracce di radici. l’ambiente delle argille è di salt marsh; f = perforazione cn15, fase b, piano battuto di colore grigio sormontato da un orizzonte di resti vegetali combusti. le carote cn1, cn2 e cn5 sono state ottenute con una macchina idraulica, per tutte le altre (tra cui quelle in figura) è stato utilizzato il metodo di carotaggio a percussione. 5. events reconstruction due to the elements collected after this study we can give a tentative reconstruction of the events at the foot of the coppa nevigata knoll. the events succession is described starting from the most ancient one (fig. 3). 5.1. a phase natural phase i the natural phase a is characterized by environments with different peculiarities, but under absent or minimal human influence. this phase has been recognized in almost all the successions, except for cn11 (that did not reach those levels) and cn1 (whose bottom is characterized by probably colluvial sediments). the cn16 core is the only one that reached the cretaceous limestone substrate and presenting evidence of marine sedimentation. above this episode and within the other drillings, the sediments are dominated by lagoon species. the lagoon environment in the external (distal) successions (a transect) is characterized by salinities ranging between 25 and 18‰ (after molluscan analysis). the correspondent section, in the internal (proximal) cores (c transect), drilled at higher elevations, seem to be conditioned by a lower salinity. all those lagoonal deposits can be related to the "hydrobiidae and cerastoderma lagoon" found in the cn2 and cn5 cores. the cores at the western end of the c transect (cn12 and cn14) show, above the lagoon sediments, salt marsh deposits. on the other hand, in the cn15 core the lagoon sediments are overlain by deposits accumulated in a dry environment at the edge of a fresh marsh. among the a transect drillings, pyroclastic deposits were found only in the cn2 core (caldara et al., 2001; 2003a), whilst in the c transect tephra are present in the cn12 (fig. 4d) and cn15 cores. tephra deposits have been found in marginal lagoon environments, within the proximal cores. the thickness of these deposits, as well as the depth, increases with the distance from the centre of the settlement. this should confirm what hypothesised in caldara et al. (2003a), that is there was first a phase of tephra accumulation due to direct fall on a large surface characterized by different environments, followed by erosion and secondary deposition in low areas. the organic deposit (caldara et al., 2001; 2003a, in press a) has been found in all bore holes in the a transect and in the deeper one in the b transect, while it is not present next to the settlement (c transect). the maximum thickness of this deposit occurs in cn13 core (a transect). at this point it looks more probable that the deposition of the organic horizon is due to washing processes acting along the slopes of the coppa nevigata knoll, rather than intentional accumulation of material dumped by man next to the lagoon edge (caldara et al., 2003a; in press a). in conclusion, in the natural phase a there are lagoon (hydrobiidae and cerastoderma lagoon), salt marsh (ovatella myosotis facies), paludal and colluvial deposits, with abundant input of sediments from the settlement. 5.2. b phase – terrestrial phase i this phase corresponds to the terrestrial phase i (caldara et al., 2003a) in the a transect cores and probably in the b transect and seems to start during the early sub-apennine (caldara et al., 2003a; in press a). the erosive surface that separates the a phase from the b phase sediments appears as sloping towards the middle of the lagoon except for the cn16 core, where a depression is outlined. actually, the cn16 core represents an anomaly; in fact, in this succession the pyroclastic horizon occurs in the b phase and not in the natural interval. this drives us to hypothesize that the area around the cn16 core, no longer lagoonal, were utilized by the coppa nevigata community from the cetina phase (recchia, 2002), or at least from the early bronze age (before the "avellino" event). the b phase is characterized by the occurrence of the first leveled surfaces (cn14 and cn15 cores, fig. 4f) and by a thick accumulation of burnt material (cn13 core). the end of the b phase is well identifiable within the distal cores (cn2 and cn5) because of the return of brackish conditions. in the other cores the b phase seems to be in continuity with the d phase. tentatively we put the limit between the b and d phases at the base of the yellowish tramping surfaces slightly above the sea level within the c transect cores, and at the base of a tramping surface laying at 0.82 m below m.s.l. in the cn13 core. 5.3. c phase natural phase ii at the moment the c phase has been recognized only for the distal cores (cn2 and cn5), while we hypothesize its continuity in the area around the cores of the b transect (fig. 3), this should be assessed by means of new drillings. in other words, the setting of the natural phase ii seems as occurred only in the northern part of the studied area, facing the present day coastline (fig. 1). the natural phase ii is characterized by the succession of three brackish environments, i.e. cerastoderma lagoon, salt marsh i and hydrobiidae and abra segmentum lagoon (caldara et al., 1999; 2001). these environments have been correlated to the hydrobiidae and cerastoderma lagoon, recognised in the middle of the basin (cn4 and cn3 cores; caldara & simone, in press). this phase occurred between the final bronze and a not well defined iron age (caldara et al., 2003a). 5.4. d phase – terrestrial phase ii in the distal area (a transect cores), the d phase corresponds to the terrestrial phase ii (caldara et al., 2003). this one represents a new phase of occupation of the areas freed by lagoon waters. the lagoon retreat seems to have been occurred because of natural causes (caldara & simone, in press). we do not know exactly when this phase developed, perhaps between the iron age and roman period (caldara et al., 2003a; in press a). the erosive surface that separates sediments pertinent to the c and d phases lays around 0 m in the distal area (a transect), whilst within the b and c transect cores, given the similar characteristics that sediments show, the limit between b and d phases is somewhat undefined. the d phase is characterized by a number of tramping/leveled surfaces. these can be single (cn15) 504 m. caldara, i. caroli & o. simone or superimposed, sometimes there is an alternation of tramping/leveled surfaces, concotto levels and burnt hearth grounds (cn12 and cn14, fig. 4b,c). as regards to the distal area (cn2 and cn5 cores), given the findings of burnt soils and domestic bone fragments, caldara et al. (in press a) hypothesized a pastoral-agricoltural land use. nevertheless, the evidence collected with this study suggests that, at the foot of the knoll, several simple inhabitation structures were in existence during the various occupation phases. 5.5. e phase natural phase iii the e phase has been identified only in the distal drillings (a transect) and corresponds to the salt marsh ii (caldara et al., 2003a). therefore, the recovery of natural environment seems has been occurred in the areas at the external margin of the settlement. the e phase sediments are cut in their upper part by an erosive surface. their chronological position is not well defined yet. in addition there were not found any anthropogenic indicators, therefore we think that, during the deposition of the e phase sediments, the coppa nevigata knoll was not inhabited. the more recent findings are vi century bc pottery fragments (pallottino, 1951); that could mean that the e phase sediments accumulated successively. 5.6. f phase arid terrestrial phase the f phase did not leave sediments; it is recognizable because of two elements, i. e. the erosive surface that cut the paludal deposits in all the distal cores (a transect) at different elevations and the presence of calcareous crusts and lumps (evaporite) in the upper part of e phase sediments. these features suggest a subaerial phase characterized by a marked pedogenesis. the thick calcareous crust indicates arid conditions lasting for a long span of time. that is why we called this phase "arid terrestrial". at the moment we are not able to say how long the terrestrial phase lasted and when the erosion occurred. the only chronological indication comes from the stratigraphic position of this event. 5.7. g phase natural phase iv the g phase corresponds, in the distal area (a transect), to the bithynia and ovatella wetland (caldara et al., 2003a). in the lower part of the g phase sediments the environment seems to be fairly brackish, whilst in the upper part the waterbody is exclusively conditioned by fresh water input. radiocarbon data, 370±50 yr bp (cn2 caldara et al., 2001) and 140±40 yr bp (simone, 2003), suggest that this wet area was set around the end of the middle ages. documentary data show that this wet area (part of salso and versentino lakes) reached its maximum development around the end of the xviii century (caldara et al., 2002b), after the ruinous floods of the cervaro and carapelle streams in 1795 (giustiniani, 1797 1805). 5.8. h phase – historical reclamation these sediments correspond to the terrestrial phase iii in caldara et al. (2003a). the h phase is well recognizable within the a and b transects, while is less apparent in the c transect because of a loss of sample occurred during coring operations. nevertheless, these sediments cover both e phase (natural wet area) and d phase sediments (anthropogenic). the accumulation of the h phase deposits occurred after reclamation projects carried out through the diversion of the candelaro stream. the very upper part of this interval is deeply disturbed by ploughing activities. 6. conclusions by this research, in the coppa nevigata area we reconstructed eight different phases grossly attributable to two different evolution patterns (fig. 3). the first one includes sediments intentionally accumulated or reworked by man. the latter includes deposits which sedimentation was basically driven by natural processes, even though materials accumulated are often directly due to man activities at the settlement. we ascribed to the "anthropogenic" pattern the b, d and h phases. the "natural" pattern includes the phases a, c, e, f and g. we found the anthropogenic sediments (b and d phases) underground, up to circa 90 m from the nearest trenches dug by archaeologists (fig. 1). these deposits were not found within the cn4 and cn3 cores, drilled respectively 400 and 800 m far from the settlement (caldara & simone, in press). on the contrary, the cn3 and cn4 cores show that the hydrobiidae and cerastoderma lagoon persisted without interruptions from the neolithic to the iron age (caldara et al., 2003b). therefore, we correlate the hydrobiidae and cerastoderma lagoon found in the cn3 and cn4 cores to the a, b, c, d and e phases identified close to the settlement. at the moment it is not possible to distinguish the limit between the anthropogenic b and d phases within the successions of the c group (next to the settlement), while these are well distinguishable in the distal a group. even though directly related to anthropogenic activities carried out at the settlement, we defined as "natural" the high organic content material included in the a phase. we consider these sediments as washed out along the side of the knoll and deposited in a hollow at its foot, instead of intentionally disposed by man in a dumping area. the developing of the b phase seems to have been started from the most internal settlement areas (cn14 and cn15 cores). this would be in accordance with a urbanization phase occurred within the perimeter described by joining the hypothetical buried parts of defensive wall found by geophysical analysis (fig. 1). on the other hand, the presence of hearths in distal areas (cn13) could be attributed to activities carried out outside the defensive wall system. as regarding the d phase (anthropogenic), by the study of the cn2 and cn5 cores (in the distal area) caldara et al. (in press b) assumed an agriculturalpastoral land use for those levels. after this study, given the presence of a number of single or multiple (superimposed) tramping/leveled surfaces in association with 505geomorphological changes ... concotto and hearths levels (cn12, cn14 and cn15), we can hypothesize, at least for the areas surrounding the settlement, the persistence of simple inhabitation/occupation units. the b and d anthropic phases recorded within the cn16 sediments are worthy of further analyses. in particular, the first consideration is that around the cn16 drilling site the colonization occurred earlier than other investigated places within the coppa nevigata area. in that case the first post neolithic occupation phases would be occurred at least starting from the early bronze age (before the "avellino" event) or perhaps from the cetina phase (recchia, 2002). in addition, the cn16 core suggests a use of the area outside the apennine defensive system (part of the wall has been found beneath the surface by geophysical surveys; fig. 1). the h phase considerably differs from the two above mentioned b and d anthropic phases. the h phase deposits accumulated after direct anthropic actions, even though sedimentation processes occurred under almost natural conditions. in fact, during the xix century, the candelaro and cervaro streams used to wander in the coastal plain without flowing into the sea through a defined mouth. as a result, great part of the tavoliere coastal area was marshy and unhealthy (caldara et al., 2002b). for this reason in that period challenging reclamation projects have been conceived (afan de rivera, 1838; 1845). to protect their fields from frequent floodings the landowners started to build embankments. subsequently, the candelaro and cervaro streams were partially (sometimes totally) diverted towards the hollows (surrounded by artificial dikes) in order to fill them by siltation. in particular, the candelaro stream was embanked and its mouth was progressively shifted downstream towards the middle of the former salso lake. as examples we quote here reclamation works made between the 1869 and the 1909 (pareto, 1865; historical maps by the italian military geographical institute), in 1939 (rotella 1984) and after the world war ii. by this study we described the evolutionary mechanisms, both anthopic and natural, that acted in the coppa nevigata area since the neolithic. nevertheless, several problems have to be fixed in the future. in particular we found that correlations among the group b cores are not reliable, thus should be useful to drill more cores around the cn1 site. the chronology of the b and d anthropic phases, well defined for the distal drillings, is not verified for those close to the settlement (c group) and raises perplexities among the archaeologists. in addition, the area around the cn16 core should be investigated, in order to verify the existence of an early colonization phase occurred outside the walls and define the limits of the bulge in the limestone substrate (fig. 3). an other arousing question is from where the coppa nevigata inhabitants supplied material used for ground leveling and to realize the tramping surfaces. in conclusion, it is apparent how man was able, through time, to modify the surrounding environment, in particular during the middle bronze (b phase), the iron age (d phase) and during the last two centuries. even when the accumulation of sediments occurred under almost natural conditions, anthropogenic activities conditioned the environment evolution, such as during the deposition of the high organic content sediments in the a phase and during the c phase. acknoledgements this study was made possible thanks to funding from the bari university research project “genesi ed evoluzione geomorfologica delle piane pugliesi e lucane”, led by prof. f. boenzi, and the bari university "dottorato di ricerca in geomorfologia e dinamica ambientale". we wish also to thank dr. giulia recchia for chronological attribution of the many pottery fragments found within the new cores and for the useful discussions about the anthropogenic sediments. references afan de rivera c. 1838 memoria su i mezzi di ritrarre il massimo profitto dal lago salpi, coordinando quest'impresa a quella piu' vasta di bonificare e migliorare la pianura della capitanata. stamperia e cartiere del fibreno, napoli. afan de rivera c. 1845 del bonificamento del lago di salpi coordinato a quello della pianura della capitanata. napoli, stamperia e cartiere del fibreno, 638 p. albore livadie c., mastrolorenzo g. & vecchio g. 1998 eruzioni pliniane del somma-vesuvio e siti archeologici dell’area nolana. in: guzzo p.g. peroni r. (ed.), archeologia e vulcanologia in campania. napoli, 39-86. andronico d., calderoni g., cioni r., sbrana a., sulpizio r. & santacroce r. 1995 geological map of somma vesuvius volcano. periodico di mineralogia, 64, 77-78. boenzi f. & caldara m. 1999 il gargano: l’uomo e l’ambiente geologico. l’universo 79(6), 736-754. boenzi f., caldara m., moresi m. & pennetta l. 2001 history of the salpi lagoon-sabhka (manfredonia gulf, italy). il quaternario 14(2) 2001, 93-104. boenzi f., caldara m., pennetta l. & simone o. in press environmental aspects related to the physical evolution of some wetlands along the adriatic coast of apulia (southern italy): a review. journal of coastal research si 39, (proceendigs of the 8th int. coastal symp.) march 14-19, 2004, itajaí, brazil. caldara m., cazzella a., fiorentino g., lopez r., magri d., simone o. 1999 primi risultati di una ricerca paleoambientale nell’area di coppa nevigata (foggia). atti del xix conv. naz. preistoria, protostoria e storia della daunia, s. severo 28-29 novembre 1998, 199-236, foggia. caldara m., cazzella a., fiorentino g., lopez r., magri d., moscoloni m., narcisi b. & simone o. 2003a the relationship between coppa nevigata settlement and the wetland area during the bronze age (south-eastern italy). in: fouache e. (ed.) the mediterranean world environment and history, 429-438, elsevier, paris. caldara m., cazzella a., fiorentino g., lopez r. & simone o. 2001 nuovi dati sull'evoluzione 506 m. caldara, i. caroli & o. simone paleoambientale nell'area di coppa nevigata (foggia). atti del xxi conv. naz. preistoria, protostoria e storia della daunia. s. severo 25-26 novembre 2000, 87-132, foggia. caldara m., cazzella a., fiorentino g. & simone o. in press a l’insediamento archeologico di coppa nevigata (tavoliere di puglia) tra uomo e ambiente. atti della riunione di lavoro del gruppo di lavoro aigeo “il contributo della geografia fisica e della geomorfologia alla ricerca archeologica”, gonnesa (ca) 2-4 settembre 2003. caldara m., cazzella a. & moscoloni m. 2002a il rapporto tra l’insediamento di coppa nevigata e l’area umida durante l’età del bronzo. in: “paesaggi d’acque. ricerche e scavi”, a cura di nuccia negroni catacchio. atti del quinto incontro di studi sulla preistoria e protostoria in etruria. sorano-farnese, 12-14 maggio 2000, 343-354, centro studi di preistoria e archeologia milano. caldara m. & palmentola g. 1991 lineamenti geomorfologici del gargano con particolare riferimento al carsismo. international conference on environmental change in karst areas, apulian excursion, september 23th -27th, 1991, “itinerari speleologici”, s. ii, v, 53-66, castellana grotte. caldara m. & pennetta l. 1993a nuovi dati per la conoscenza geologica e morfologica del tavoliere di puglia. bonifica, 8(3), 25-42, bastogi, foggia. caldara m. & pennetta l. 1993b ambienti aridi del tipo "sabkha" nei sedimenti olocenici della piana costiera fra manfredonia e zapponeta. bonifica, 8(3), 73-82, bastogi, foggia. caldara m. & pennetta l. 1996 influenza del clima sul paesaggio neolitico del basso tavoliere di puglia atti seminario internazionale "forme e tempi della neolitizzazione nell'italia meridionale e in sicilia" rossano calabro, 29 aprile 2 maggio 1994, tomo ii, 559-568, con bibliografia. caldara m., pennetta l. & simone o. 2002b holocene evolution of the salpi lagoon (puglia, italy) int. coastal symp., templepatrick, northern ireland, march 25th-29th 2002, journal of coastal research si 36, 124-133. caldara m., pennetta l. & simone o. in stampa b l’ambiente nell'area dell'insediamento neolitico di masseria candelaro. in: “il villaggio neolitico di masseria candelaro” a cura di cassano s. & manfredini s., 20pp, figg 8, grenzi editore, foggia caldara m., pennetta l. & zito g. 1994 l'area umida alla foce del candelaro: osservazioni paleoambientali e climatiche. atti ii workshop sul tema "parchi naturali ed aree protette" del progetto strategico "clima ambiente e territorio nel mezzogiorno", s. maria di salina (isole eolie me) 28-30 maggio 1990, 211-234. caldara m. & simone o. 2003 the area of coppa nevigata settlement between history and environmental changes. final conference “quaternary coastal morphology and sea-level changes”, otranto/taranto – puglia (italy) 22-28 september 2003, field guide book gi2s coast, research publication 5, 139-147. caldara m. & simone o. (in press) coastal changes in the eastern tavoliere plain (puglia, italy) during the late holocene: natural or anthropic? quat. sci. rev. caldara m., simone o., gehrels r.w., in preparation holocene environmental changes in the palude frattarolo lago salso area (tavoliere plain southern italy). to be submitted. caldara m., simone o., porzia s., 2003b l’aera umida di coppa nevigata tra neolitico e l’età del bronzo. atti del 23° convegno nazionale sulla preistoria, protostoria e storia della daunia, s. severo 23 24 novembre 2002. stabilimento litografico centrografico francescano, foggia, 203-230. cazzella a. 1996a coppa nevigata. atti seminario internazionale "forme e tempi della neolitizzazione nell'italia meridionale e in sicilia" rossano calabro, 29 aprile 2 maggio 1994, tomo i, 108-114 cazzella a. & moscoloni m. 1988 la ripresa degli scavi nei livelli dell’età del bronzo di coppa nevigata. atti vii convegno preistoria, protostoria e storia della daunia, san severo, dicembre 1985, 103110. cazzella a. & moscoloni m. 1990 recenti scavi nei livelli dell’età del bronzo di coppa nevigata (campagne 1988-1989). atti xi convegno nazionale sulla preistoria, protostoria e storia della daunia, san severo, dicembre 1989, 99-115. cazzella a. & moscoloni m. 1999 the walled bronze age settlement of coppa nevigata, manfredonia, and the development of craft specialisation in southeastern italy. in: tykot r.h., morter j., robb j.e. (eds.), social dynamics of the prehistoric central mediterranean. accordia specialist studies on the mediterranean 3, 205-216, london. cazzella a., moscoloni m. & recchia g. 2001 coppa nevigata: campagne di scavo 1999 e 2000. atti xix convegno nazionale sulla preistoria, protostoria e storia della daunia, 24-26 novembre 2002, san severo, 153-170. giustiniani l. 1797-1805 dizionario geografico ragionato del regno di napoli. stamperia giovanni de bonis, tomo xi (parte ii, tomo i), napoli. levi s.t., cioni r. & cazzella a. 1999 presenza di materiale pomiceo dell’eruzione vesuviana di avellino nella cerimica dell’età del bronzo di coppa nevigata (fg). in: c. albore livadie (ed.) “l’eruzione vesuviana delle “pomici di avellino” e la facies di palma campania, 341-354, edipuglia, bari. luperto sinni e. & masse j.p. 1986 données nouvelles sur la stratigraphie des calcaires de plateforme du crétacé inférieur du gargano (italie méridionale). riv. it. paleont. strat., 42, 33-66. minnitti c. 1999 lo sfruttamento dei molluschi nell’età del bronzo di coppa nevigata atti xix conv. preistoria, protostoria e storia della daunia, san severo, 28-29 novembre 1998, 177-197. mosso a. 1909 stazione preistorica di coppa nevigata presso manfredonia. monumenti antichi dei lincei, 19, roma. pallottino m. 1951 vaso egiziano inscritto proveniente dal villaggio preistorico di coppa nevigata. rend. acc. lincei, vi fasc. 11-12, 580-590. pareto r. 1865 sulle bonificazioni, risaie ed irrigazioni del regno d'italia. relazione a s.e. il ministro di agricoltura, industria e commercio. milano, 507geomorphological changes ... tipografia e litografia degli ingegneri, 270 pp. puglisi s.m. 1955 industria microlitica nei livelli a ceramica impressa di coppa nevigata. riv. sc. preist. 10, 19-37. puglisi s.m. 1975 lo strato neolitico di coppa nevigata. atti colloquio internazionale sulla preistoria e protostoria della daunia, foggia, 2428 aprile 1973. iipp, firenze. puglisi s.m. 1982 coppa nevigata (manfredonia, foggia). in: vagnetti l. (ed.), magna grecia e mondo miceneo. nuovi documenti. atti xxii conv. studi magna grecia, taranto 7-11 ottobre 1982, 45-51. recchia, g. 2002 i siti costieri garganici e i loro rapporti transmarini tra eneolitico ed età del bronzo. in: "paesaggi d’acque" a cura di n. negroni capacchio, sorano-farnese 13-14 maggio 2000, 331-341. rolandi g., mastrolorenzo g., barrella a.m. & borrelli a. 1993 the avellino plinian eruption of sommavesuvius (3760 y. b.p.): the progressive evolution from magmatic to hydromagmatic style. journal of volcanology and geothermal research, 58, 67-88. rotella g. 1984 cinquant’anni di bonifica nel tavoliere. in: ciccone s. (ed.) cinquant’anni di bonifica nel tavoliere, 31-171, bastogi ed. foggia schmiedt g. 1973 contributo della fotografia aerea alla ricostruzione dell'antica laguna compresa fra siponto e salapia, arch. stor. pugl., 26, 159-172. simone o. 2003 evoluzione olocenica e dinamica ambientale delle piane costiere pugliesi. tesi di dottorato inedita. università degli studi di bari bari, 171 pp. terrasi f., campajola l., petrazzuolo f., roca v., romano m., brondi a., d’onofrio a., romoli m. & moniot r.k. 1999 datazione con la spettrometria di massa ultrasensibile di campioni provenienti dall’area interessata dall’eruzione delle “pomici di avell ino” . in: albore livadie c. (a cura di), l’eruzione vesuviana delle “pomici di avellino” e la facies di palma campania. edipuglia, bari, 139146. 508 ms. ricevuto il 17 luglio 2004 testo definitivo ricevuto il 28 settembre 2004 ms. received: july 14, 2004 final text received: september 28, 2004 m. caldara, i. caroli & o. simone imp.resoconto la stratigrafia in italia. inquadramento storico, stato dell'arte, dibattito sui problemi emergenti (breve resoconto sul workshop) maria bianca cita abstract: m. b. cita, stratigraphy in italy. gssps, geosites, mapping problems, quaternary definition. the second workshop of the renovated italian commission on stratigraphy, held during two days (september 10 and 11, 2007) at the 6th italian forum of geological sciences is here reported. after an initial historical introduction, special attention was given to the gssps defined or proposed in italy, to the geosites, to the relevance of stratigraphic principles in official geological maps. the newly published volumes of the catalogue of italian formations were commented and distributed. finally, the present debate on the status of the quaternary was discussed without reaching a consensus position. parole chiave: stratigrafia, piani standard definiti o proposti in italia, geositi, quaternario. keywords: stratigraphy, gssps, geosites, catalogue of italian formations, quaternary. il quaternario italian journal of quaternary sciences 21(1a), 2008 5-6 questo è il titolo di un workshop della durata di due intere giornate indetto dalla commissione italiana di stratigrafia (cis). conveners, il presidente m.b. cita e il vice-presidente b. d'argenio, coadiuvati dai due segretari m. balini e f. lirer. si tratta del secondo workshop indetto in occasione dei convegni biennali della fist. il primo si era svolto a spoleto due anni fa. come quello, anche il secondo workshop è stato seguito assiduamente e con molto impegno da diverse decine di partecipanti appartenenti al mondo accademico, al servizio geologico, a enti di ricerca e professionisti. notata la presenza occasionale anche di alcuni stratigrafi stranieri. i l programma era stato studiato con cura in modo da presentare diversi temi con interventi tutti a invito. il primo tema (inquadramento storico) è stato trattato da g.b. vai, m.b. cita e b. d'argenio nell'ordine, illustrando sinteticamente la preistoria della stratigrafia italiana (g.b. vai), i codici di nomenclatura stratigrafica (m.b. cita) e l'influenza della geologia stratigrafica di azzaroli e cita (1963) sulla stratigrafia ital iana (b.d'argenio). il secondo tema (stratotipi definiti/proposti in italia) ha visto la presentazione mediante power points molto ben documentati delle seguenti sezioni in fase di studio avanzato: prati di stuores (presso pralongià nelle dolomiti ampezzane) per il carnico gssp (presentazione m. balini) pizzo mondello (sicilia) per il norico (presentazione m. balini e p. di stefano) sezione di alano di piave nel trevigiano occidentale per il gssp del priaboniano e forse anche per il gssp del bartoniano (presentazione i. premoli silva e d. rio) monte conero per il gssp del cattiano (presentazione i. premoli silva e r. coccioni) infine f. lirer e s. iaccarino hanno presentato un ampio rapporto sull'attività della rcmns (regional committee on mediteranean neogene stratigraphy, di cui f. lirer è il segretario) sulla stratigrafia integrata e sul prossimo congresso che si terrà a napoli nel 2009, organizzato da s. iaccarino, b. d'argenio e f. lirer. alla fine della sessione sono stati presentati i tre piani proposti per il quaternario che sono stati illustrati e presi in seria considerazione anche nel congresso inqua tenutosi recentemente a cairns (australia) (presentazione di m. coltorti e f. antonioli) in assenza di e. di stefano, il calabriano è stato presentato da n. ciaranfi. sempre n. ciaranfi ha presentato anche lo ioniano, il cui gssp è stato correlato al limite brunhes/matuyama. infine f. antonioli e g.b. vai hanno presentato la sezione del mare piccolo di taranto, che potrebbe essere proposta come gssp del pleistocene superiore in sostituzione dell'eemiano e/o del tirreniano. il terzo ed ultimo tema della prima giornata (geositi e gssp) è stato di grande interesse per tutti. degli otto gssp definiti e ratificati finora in italia, soltanto quello del limite eocene/oligocene che si trova all'interno del parco del conero risulta essere segnalato adeguatamente e protetto (relazione r. coccioni e i. premoli silva). sui siti che definiscono il limite miocene/pliocene e la base dello zancleano, nonché i l gssp del piacenziano che si trovano in provincia di agrigento, riferisce ampiamente p. di stefano, che intrattiene ottimi rapporti con le autorità locali, ma incontra grosse difficoltà nel raggiungere risultati concreti e definitivi a causa della mobilità delle autorità referenti. p. di stefano ritiene indispensabile un'azione coordinata a livello nazionale. l'intervento del vulcanologo l. lirer evidenzia un altro aspetto del problema, ossia la fruibilità turisticoculturale di aree di straordinario significato geologico. infine l'intervento dell'ingegnere l. bonci del dipartimento difesa dell'ambiente e della natura dell'apat mostra i risultati del censimento dei geositi effettuato dopo il workshop della commissione italiana di stratigrafia svoltosi a spoleto nel 2005 riguardanti i vari gssp. nel dibattito seguente si ravvisa l'opportunità di proporre concretamente al dott. a. todisco, direttore del dipartimento difesa dell'ambiente e della natura dell'apat di gestire direttamente i geositi dei gssp, che rappresentano un punto di riferimento mondiale di uno standard accettato da tutti gli organi preposti (proposta di p. di stefano). la seconda giornata si è aperta con il tema la stratigrafia nella cartografia geologica italiana. dopo una breve introduzione sul lavoro settennale svolto dalla commissione italiana di stratigrafia per conto del servizio geologico d'italia attraverso una serie di accordi di programma e contratti gestiti dal prof. p. manetti, la prof.ssa cita annuncia la pubblicazione degli ultimi quattro fascicoli della serie (quaderno 7) che illustrano formazioni definite in italia e validate dalla commissione italiana di stratigrafia nonché (negli ultimi due fascicoli) i cosiddetti nomi tradizionali. i fascicoli appena stampati sono esposti allo stand del servizio geologico al geoforum e tutti gli intervenuti sono invitati a ritirarne una copia durante il coffee break. i primi interventi, molto efficaci e convincenti, sono presentati da geologhe del servizio geologico. c. d'ambrogi illustra problemi e potenzialità delle ubsu per l'interpretazione e rappresentazione cartografica dei depositi marini. e. la posta tratta dei depositi plio-quaternari continentali dell'italia centro-meridionale. e. chiarini tratta dei depositi dell'arco alpino, della pianura padana e sardegna. altri interventi sull'utilizzo delle ubsu sono stati presentati da: giannandrea e principe sui depositi vulcanici del monte vulture (foglio melfi, ora pubblicato in un volume speciale della regione basilicata). g. pappone e b. d'argenio presentano il foglio salerno (cartografia terra e mare, raccolta dati durata oltre 10 anni). seduta interessante con interventi di m. coltorti e miccadei, anche se il dott. galluzzo, direttore del carg, lamenta l'assenza di molti operatori del settore. seguono gli interventi di l. sagnotti sulle variazioni paleomagnetiche secolari in record sedimentari marini e di g. muttoni su esempi di applicazioni della stratigrafia paleomagnetica alla definizione di gssp triassici. il tema più scottante all'interno del workshop avrebbe dovuto essere quello finale (la querelle sul quaternario). le discussioni non sono mancate, e hanno talvolta raggiunto toni accesi. al congresso inqua appena tenutosi a cairns la votazione per abbassare il limite del quaternario è passata senza voti contrari. ma secondo alcuni fra i presenti non è sufficiente che il quaternario venga riconosciuto come sistema e che la comunità internazionale sia incline o addirittura pronta ad adottare come sezioni-tipo quelle dell'italia meridionale, ma considerano irrinunciabile mantenere il limite attuale. questo atteggiamento ha fatto si che non si arrivasse a una posizione condivisa dalla comunità stratigrafica italiana. in conclusione il workshop è stato utilissimo per chiarire a che cosa serve veramente la commissione italiana di stratigrafia, che non può certo coordinare o migliorare la produzione scientifica degli italiani. essa ha due funzioni principali: 1) rappresenta l'interfaccia con la commissione internazionale di stratigrafia; 2) interagisce con il servizio geologico d'italia. la cartografia ha bisogno di una stratigrafia corretta, valida, aggiornata e la commissione ha bisogno del servizio. il nuovo legame con il dipartimento per la difesa dell'ambiente e della natura dell'apat che ci si propone di stabilire per la protezione dei gssp rappresenta il trait d'union tra le due interfacce. gli interventi programmati non avevano dato luogo alla presentazione di riassunti prima del workshop. essi sono stati raccolti e quelli presentati in tempo utile sono pubblicati in questo fascilo. milano, 1° ottobre 2007 6 maria bianca cita ms. ricevuto il 2 aprile 2008 testo definitivo ricevuto il 17 aprile 2008 ms. received: april 2, 2008 final text received: april 17, 2008 il ruolo svolto da piene straordinarie nel rimodellare la geometria di un alveo fluviale ornella turitto, chiara audisio & andrea agangi consiglio nazionale delle ricerche istituto di ricerca per la protezione idrogeologica (cnr-irpi) strada delle cacce, 73 10135 torino e-mail: ornella.turitto@irpi.cnr.it riassunto: turitto o., audisio c. & agangi a., il ruolo svolto da piene straordinarie nel rimodellare la geometria di un alveo fluviale (it issn 0394-3356, 2008). in alcuni corsi d'acqua dell'italia centro-settentrionale è stata recentemente osservata una tendenza ad un più o meno sensibile aumento della larghezza globale del letto, subentrata dopo un lungo periodo culminato negli anni '70 e '80 del secolo scorso in cui si erano diffusamente manifestati fenomeni di restringimento ed incisione degli alvei. questi ultimi fenomeni, risultati particolarmente accelerati da vari tipi di condizionamento da parte dell'uomo, avevano portato alla trasformazione dell'originario modello fluviale a più canali di deflusso, tipico del xix secolo, verso forme ad unico canale. ne era derivata un'acquisizione di nuovi spazi ad uso antropico, ma con gravi ripercussioni sulla vulnerabilità di beni pubblici e privati collocati all'interno o in prossimità dell'ambito fluviale. il caso di studio presentato si riferisce al torrente orco, tributario alpino del fiume po in territorio piemontese. nella nota viene inizialmente fornito un quadro delle tappe evolutive (dedotte da analisi multitemporale di cartografia storica e di riprese aerofotografiche, con il supporto di applicativi gis) che, a partire dal xix secolo, hanno accompagnato la semplificazione dell'assetto planimetrico dell'alveo, con marcata riduzione della sua larghezza; i minimi valori di ampiezza sono stati raggiunti negli anni '70 e '80, in concomitanza della massima diffusione e intensità dell'attività estrattiva. si descrivono quindi i meccanismi prevalenti che, in occasione di recenti piene eccezionali con valori di portata superiori ad ogni massimo precedente (nel settembre 1993 e nell'ottobre 2000), hanno indotto un'inversione di tendenza; in particolare si illustra come nel 2000 un sensibile aumento di larghezza dell'alveo sia avvenuto attraverso processi di erosione laterale o per riattivazione di originari spazi fluviali naturalmente abbandonati o artificialmente sottratti, con risultati che ripropongono, seppur localmente e forse solo temporaneamente, forme d'alveo pluricursali analoghe a quelle del passato. brevi cenni sulle differenti variazioni morfologiche intervenute durante le gravi piene del settembre 1947 e dell'ottobre 1977, con portate tra loro confrontabili, sottolineano ulteriormente gli effetti del condizionamento imposto dall'uomo: nel 1947, con sistema di deflusso non ancora monocursale e disponibilità di sedimenti in alveo, si è prodotto in lunghi tratti un aumento della sezione d'alveo; nel 1977, con unico canale di deflusso sinuoso-meandriforme in fase di incisione e massiccio depauperamento di sabbie e ghiaie, l'alveo non ha mostrato un significativo aumento di larghezza, ma un'accentuazione delle anse presenti. le varie situazioni vengono illustrate attraverso il confronto di immagini tratte da riprese aeree eseguite prima e dopo gli episodi di piena. infine, nell'ottica di una cautelativa gestione dell'ambito fluviale indagato, si sottolinea la necessità di salvaguardare gli spazi necessari alla potenziale mobilità laterale del corso d'acqua chiaramente emersa nel corso della piena del 2000 per garantirvi in futuro un naturale sviluppo delle componenti morfologiche e biologiche. abstract: turitto o., audisio c. & agangi a., the role of severe floods in the adjustment of river channel geometry (it issn 03943356, 2008). numerous studies on river channel adjustments have focused on the role played by human activities in the processes of channel narrowing and incision which took place in several alluvial channels of the italian rivers. the influence of embankments, bank protections, bridge structures and sediment mining appeared remarkable from the 1950s until the 1980s. whereas a more or less evident process of channel widening was observed in some of these italian rivers after the 1980s, leading to an opposite trend. through this note the authors mean to provide a representative example. the study case refers to the orco river, an alpine tributary of the po river in the turin territory (north-western italy); it drains 906 km2 and its channel is 83 km long. in the study reach, corresponding to the lower 36 km of the river course (mean channel slope 0.7%), the channel is incised in the cobble and gravel deposits of the plain. data collected come from different sources: a) published and unpublished information derived above all from ministero dei lavori pubblici official publications about italian rivers, from technical reports and designs of fluvial defence or bridge construction (mainly produced by genio civile) and from regione piemonte archives (as flood levels and discharges recorded at a historical hydrometric gauging station); b) historical and most recent maps dating from 1881 to 1991 (by istituto geografico militare italiano, magistrato per il fiume po, regione piemonte) at scales ranging between 1:25.000 and 1:5.000; c) aerial photographs taken every decade since 1945 until 2003 (by istituto geografico militare italiano, cnr-irpi di torino, regione piemonte and provincia di torino) at scales ranging between 1:45.000 and 1:5.000. through aerial photographs one could also verify the hydrographical configuration of the river on the maps drawn at the same date. through geographical information system (gis) procedures, the planimetrical situations of the river channel at various dates were superimposed over the regional technical map of the regione piemonte on a 1:10.000 scale; the different channel configurations were compared and measured. investigations demonstrated that during the 19th century the river course showed almost everywhere a multi-thread channel with forms and numbers of ramifications variable both in space and time. however a slow and progressive simplification of fluvial configuration was observed; it was mainly produced through the abandoning of secondary ramifications and the islands joining the surrounding floodplain. this process was partly due to natural phenomena, persisting until the first half of the 20th century. in the last 50 years, however, the process was heavily accelerated by human activity, above all by channel regulation works and excessive sediment mining. these activities led to a rapid change in channel patterns, from multi-thread to wandering or single-thread configuration, favoured by a deepening of the river bed (1÷2 m on an average and a local maximum of 3.5 m). severe floods which occurred during the last years, in september 1993 (1500 m3/s) and in october 2000 (1650 m3/s), modified, however, the river bed geometry. in particular, the 2000 flood (the largest in the 80-year recording period) induced a remarkable increase of the mean channel width, also due to the renewed availability of sediments in the river bed due to the stop of excessive sediment mining after the 1980s. the aim of this work is to illustrate some morphological effects triggered by these two severe floods. it also provides some examples of il quaternario italian journal of quaternary sciences 21(1b), 2008 303-316 304 o. turitto et al. 1. introduzione ricerche condotte sulle variazioni planimetriche degli alvei, con trasformazione dell'originario modello fluviale da forme pluricursali (tipiche del xix secolo) verso forme tendenti al monocursale, hanno sottolineato il contributo fornito dalle attività antropiche in questi processi, in particolare sul restringimento e sull'incisione del letto riscontrati in numerosi corsi d'acqua italiani. della numerosa produzione scientifica disponibile sull'argomento si segnalano, a titolo di esempio, i lavori su corsi d'acqua dell'italia settentrionale pubblicati da pell e g r i n i et al. (1979), ca s t i g l i o n i & pe l l e g r i n i ( 1 9 8 1 ) , maraga & mortara (1981), bezoari et al. (1984), maraga (1989), go v i & tu r i t t o (1993), du t t o & ma r a g a ( 1 9 9 4 ) , ca s t a l d i n i et al. (1999), su r i a n n. (1999), ma r c h e t t i (2002), su r i a n et al. (2005). gli aspetti emersi lungo corsi d'acqua dell'italia centro-meridionale, talora con gravi ripercussioni anche sul fenomeno di arretramento della linea di costa, sono descritti, ad esempio, nelle pubblicazioni di gentili & pambianchi (1987), coltorti et a l. (1991), ca n u t i et al. (1992), bi g g i e r o et al. (1994), rinaldi & rodolfi (1995), rinaldi & simon (1998), aucelli & ro s s k o p f (2000), ri n a l d i (2003), sa b a t o & tr o p e a n o (2004). in anni recenti sono state inoltre prodotte sintesi sull'argomento, sia attraverso una dettagliata analisi di casi nazionali, sia mettendo a confronto situazioni italiane ed estere (su r i a n & ri n a l d i, 2003; ri n a l d i et al. , 2005). in questi lavori emerge come l'influenza esercitata da arginature, da protezioni di sponda, da strutture di attraversamento fluviale ed in particolare da attività estrattiva in alveo sia risultata determinante nell'esaltare i processi di restringimento e di incisione del letto, soprattutto a partire dalla seconda metà del '900. per contro, in alcuni corsi d'acqua dell'italia centro-settentrionale è stata recentemente osservata un'inversione di tendenza documentata da fine anni '80 o da inizio anni '90, a seconda dei vari bacini che ha portato ad un aumento di larghezza dell'alveo attraverso processi di erosione spondale o di riattivazione di originarie superfici fluviali e ramificazioni periferiche abbandonate da tempo (surian & rinaldi, 2004; surian et al., 2005; turitto & audisio, 2005; surian, 2006). gli incrementi di larghezza riscontrati hanno assunto valori particolarmente elevati in riferimento ad un corso d'acqua, il torrente orco (pe l l e g r i n i et al., 2008), lungo il quale nell'ultimo decennio del secolo scorso sono transitate in due occasioni (nel 1993 e nel 2000) portate superiori al massimo storico precedente. il risultato delle repentine modificazioni di forma e dimensione d'alveo intervenute durante questi episodi di piena (ad elevata intensità, ma bassa frequenza) non può però ritenersi duraturo, in quanto dipeso da portate ben al di sopra di quelle “efficaci” (an d r e w s, 1980) necessarie e sufficienti per una movimentazione di sedimenti in grado di mantenere nel tempo una determinata configurazione d'alveo. tuttavia si ritiene che un'analisi di queste profonde modificazioni illustrate nella presente nota, unitamente a cenni di confronto su quanto avvenuto anche nel corso delle piene del 1947 e del 1977 possa fornire utili spunti di riflessione sulle potenzialità dinamiche di un corso d'acqua in occasione di eventi di estrema gravità. ciò soprattutto nell'ottica di un ipotizzato “aumento nella frequenza di eventi intensi di precipitazione negli ultimi decenni” (rogora et a l., 2004) per effetto dei cambiamenti climatici in atto (société hydrotecnique de france, 2004; lebensministerium, 2006) anche se, a tal riguardo, sussistono motivi di incertezza (european environment agency, 2004). 2. il caso di studio il torrente orco, tributario alpino del fiume po, si origina dalle pendici della becca di moncorvè (3865 m s.l.m.) nel massiccio cristallino del gran paradiso, composto da prevalenti gneiss occhiadini. il corso d'acqua drena una superficie di 906 km2, di cui 617 km2 in territorio montano, ed ha una lunghezza di 83 km dalla sorgente al fiume po, in cui sbocca a quota 177 m s.l.m.; percorre gli ultimi 36 km nel tratto di pianura (fig. 1), dove presenta un alveo a fondo ciottoloso-ghiaioso con una pendenza media di 0,7%. la nota prende spunto da una ricerca che era stata condotta su questo percorso di pianura (turitto & audisio, 2005) per ricostruire le modificazioni avvenute durante gli ultimi due secoli nel contesto naturale e antropico. indagini di maggior dettaglio si erano focalizzate sul tratto intermedio di 25 km, suddiviso nei sottotratti (oc01.02, oc02.01, oc02.02, oc03.01 in fig. 1) che in uno studio promosso dall'autorità di bacino del fiume po venivano definiti omogenei, in funzione del modello fluviale (alveotipo) allora prevalente (autorità di the effects triggered by previous severe floods similar to each other in peak flow discharge which, however, occurred in different morphological conditions and sediment availability: with plenty of sediments the september 1947 flood (1410 m3/s, the largest before the 1993) induced a widening of the braiding/wandering channel; with lack of sediments the october 1977 flood (about 1300 m3/s) did not produce a widening of the channel (which meanwhile had turned into a narrow, incised and sinuous channel), but a bend growth. the selected cases shown in the figures point out the most frequently observed processes: reactivation of old branches naturally abandoned or artificially closed off; severe bank erosion; opening of new peripheral branches by overflowing; variation of river bed elevation; bend growth; formation of new islands dissected from the floodplain by channel avulsion; adjustment of channel geometry proposing again (maybe only temporarily) the old multi-thread morphological configuration. the study points out that the channel widening which occurred during the 2000 flood suggests the necessity to assign to the river a large space of mobility to explain fluvial dynamics. moreover, for a more natural future river management, an undisturbed wide space of freedom will allow a restoration of both morphological and biological components of the fluvial system. parole chiave: dinamica fluviale, piena estrema, analisi multitemporale, torrente orco, italia nord-occidentale. keywords: fluvial dynamics, extreme flood, multitemporal analysis, orco river, north-western italy. bacino del fi u m e po, 1995). in particolare, gli alveotipi segnalati per ciascun sottotratto erano, da monte verso valle: oc01.02 da sinuoso a subrettilineo con barre longitudinali e laterali; oc02.01 sinuoso con barre longitudinali e laterali e isole; oc02.02 sinuoso con caratteri pluricursali; oc03.01 da sinuoso a meandriforme nel settore superiore e intermedio, ramificato con barre longitudinali nel settore inferiore. dall'analisi più approfondita erano stati esclusi i primi 10 km di monte, perchè qui la geomorfologia locale non aveva consentito al corso d'acqua di manifestare una mobilità planimetrica tale da garantire significative misure di variabilità, e il chilometro finale, perchè qui le vicende evolutive dell'orco erano strettamente legate alle vicende del po e ormai troppo compromesse per l'eccessivo condizionamento subito da parte dell'uomo. la ricerca aveva preso avvio dalla consultazione di materiale bibliografico ed archivistico: monografie sul corso d'acqua e sugli eventi di piena; pubblicazioni ufficiali del ministero lavori pubblici (come i “dati caratteristici dei corsi d'acqua italiani”, editi dal 1934 al 1980); rapporti tecnici e progetti del genio civile, corredati da planimetrie di dettaglio, compilati in occasione di realiz305il ruolo svolto da piene straordinarie ... zazioni, ricostruzioni o adeguamenti di opere di difesa o ponti; articoli di giornali a diffusione nazionale e locale; serie storica degli idrogrammi registrati alla stazione di misura di pont canavese (consultata presso gli archivi dell'arpa piemonte). verifiche e integrazioni del quadro acquisito erano derivate da analisi multitemporale comparata di cartografia storica e foto aeree in visione stereoscopica. nel primo caso si era fatto uso di cartografie di inizio e metà '800 in scala 1:50.000, delle tavolette dell'istituto geografico militare italiano (igmi) in scala 1:25.000 (edizioni dal 1881 agli anni '60 del secolo scorso) e delle restituzioni aerofotogrammetriche, sia in scala 1:5.000 (magistrato per il fiume po, 1962), sia in scala 1:10.000 (carta tecnica regionale, ctr del piemonte, 1991). nel secondo caso si erano utilizzate riprese aeree con scala media compresa tra 1:45.000 e 1:5.000 che, a partire dal 1945, coprono l'asta fluviale indagata anche più volte nello stesso decennio, fino al 2003 (realizzate dall'igmi, dal cnr-irpi di torino, dalla regione piemonte, dalla provincia di torino e da privati). con l'ausilio di applicativi gis (geographical information s y s t e m) le configurazioni idrografiche di ciascun anno erano state sovrapposte sulla base topografica della ctr in scala 1:10.000, consentendo confronti sulla presenza e distribuzione dei vari elementi fluviali, nonché misure di alcuni parametri, tra cui la larghezza dell'alveo. vengono qui di seguito sintetizzati i principali aspetti emersi nel corso della ricerca. 2.1 semplificazione del sistema di deflusso per tutto il xix secolo il torrente orco ha manifestato nel tratto di pianura un modello fluviale a più o meno marcata plur icursalità, variabile nello spazio e nel tempo, accompagnata da una lenta e progressiva semplificazione del sistema di deflusso. l'occasionale perdita di ramificazioni secondarie, dovuta in parte a cause naturali come le variazioni delle condizioni idrologiche a scala di bacino (me r c a l l i & ca t be r r o, 2005), è perdurata fino al la prima metà del xx secolo. nella seconda metà del secolo, invece, tale processo di sempli ficazione è apparso pesantemente accelerato per motivi strettamente connessi all'attività antropica nelle sue varie forme, soprattutto per la costruzione di difese e ponti ( tu r i t t o & au d i s i o, 2008) e per l'estrazione di inerti dall'alveo (govi, 1976). ciò ha comportato un'accentuata perdita degli originari spazi fluviali periferici con fig. 1 torrente orco nel percorso di pianura. sono indicati i sottotratti indagati: oc01.02, oc02.01, oc02.02, oc03.01, definiti “omogenei” dall'autorità di bacino del fiume po in funzione dell'alveotipo prevalente. sono inoltre ubicati i siti che compaiono nelle figure da 4 a 8. the orco river course in the plain. the investigated sub-reaches are indicated: oc01.02, oc02.01, oc02.02, oc03.01, they have been defined “homogeneous” by autorità di bacino del fiume po on the basis of the prevalent channel pattern. the sites shown in figures 4 to 8 are also indicated. trasformazione della geometria dell'alveo da forme pluricursali a forme di transizione verso il singolo canale di deflusso (fig. 2); il fenomeno si è tradotto in una riduzione della larghezza globale dell'alveo (fig. 3a) comprensivo, oltre che dei canali occupati dalle acque, anche delle barre e delle isole, elementi fluvial i intesi secondo quanto descritto da br i c e (1964) e riproposto da thorne (1997). nel periodo 1881-1989 tale riduzione è risultata variabile tra il 50% e il 70% per i vari sottotratti, ma quasi ovunque particolarmente concentrata tra gli anni '60 e '80 del secolo scorso, con un massimo del 52% per il tratto intermedio oc02.02. contemporaneamente si è riscontrato un abbassamento del fondo alveo per incisione del canale dei deflussi ordinari, che col tempo si è trovato a prevalere rispetto ad altri rami secondari. a seguito di misure eseguite negli anni '70 con tecniche topografiche e fotointerpretative su 14 siti campione distribuiti lungo tutto il percorso di pianura ( go v i, 1976), l'entità dell'approfondimento subito nel periodo 1961-1975 è stato valutato mediamente in 1÷2 m, con un massimo locale di 3.50 m ottenuto pochi chilometri a monte dello sbocco di orco in po. 2.2 inversione di tendenza analizzando la figura 3a appare evidente come le variazioni di larghezza dell 'alveo riscontrate in ciascun sottotratto considerato, pur seguendo andamenti abbastanza diversificati per il differente contesto morfologico e antropico, mostrino i minimi valori tra gli anni '60 e '80 del secolo scorso. analogamente, in tutti i sottotratti si può notare un incremento dei valori nel periodo successivo al 1989; l'incremento minimo ha riguardato il sottotratto oc03.01 (+99%), il massimo è stato misurato in oc02.02 (+213%). tali picchi nei valori di larghezza dell'alveo risultano essere in gran parte connessi agli effetti morfologici prodotti dalle piene del settembre 1993 e dell'ottobre 2000 che, con portate rispettivamente di 1500 m3/s e di 1650 m3/s, hanno superato il massimo storico precedente (1410 m3/s) registrato nel settembre 1947 (fig. 3b). grazie alla documentazione aerofotografica in visione stereoscopica realizzata dopo ciascun evento, è stato possibile confrontare la nuova situazione morfologica modellata dal corso d'acqua durante le piene con quella ripresa in precedenza, a pochi anni di distanza; ciò ha permesso di analizzare con dettaglio il risultato della molteplicità di processi innescati dalla corrente fluviale. inoltre, la disponibilità del materiale aerofotografico realizzato con notevole ripetitività dopo il 1945 ha permesso di fornire alcuni esempi di quanto avvenuto lungo il corso d'acqua anche in occasione di analoghe gravi piene precedenti a quelle di fine secolo. 3. esempi di effetti morfologici prodotti dalle piene le notevoli capacità dinamiche manifestate dal torrente orco a fronte dell'evento straordinario dell'ottobre 2000, sono state in grado di rimodellare profondamente la geometria dell'alveo lungo pressoché l'inte306 fig. 2 torrente orco tra rivarolo e feletto. mobilità planimetrica manifestata dai canali di deflusso dal 1881 (da carta topografica igmi in scala 1:25.000) al 1989 (da ripresa aerea igmi in scala media 1:36.000) con trasformazione del modello fluviale dal pluricursale verso il monocursale. the orco river from rivarolo to feletto. planimetric mobility of the channel between 1881 (from igmi topographic map on a 1:25.000 scale) and 1989 (from igmi aerial photograph on a 1:36.000 mean scale) with the pattern transformation from the multi-thread toward the singlethread configuration. o. turitto et al. 307 fig. 3 a: larghezza dell'alveo comprensivo delle isole fluviali (l) nel periodo 1881-2003 in ciascun sottotratto “omogeneo” per tipologia d'alveo (oc01.02: da sinuoso a subrettilineo con barre longitudinali e laterali; oc02.01: sinuoso con barre longitudinali e laterali e isole; oc02.02: sinuoso con caratteri pluricursali; oc03.01: da sinuoso a meandriforme nel settore superiore e intermedio, ramificato con barre longitudinali nel settore inferiore). la larghezza dell'alveo è ricavata da cartografia in scala 1:25.000 (cerchio vuoto) e da aerofotografie a varia scala (cerchio pieno). b: variazione dei valori al colmo di altezza (h, linea sottile) e/o portata (q, istogramma) registrati alla stazione di misura di pont canavese (617 km2 di bacino sotteso) fino al 1979 e nel 1993, alla stazione di cuorgnè (630 km2 di bacino sotteso) nel 2000. a: width of river channel including fluvial islands (l) over the 1881-2003 period in each sub-reach with a “homogeneous” channel pattern (oc01.02: sinuous to straight with longitudinal and lateral bars; oc02.01: sinuous with longitudinal and lateral bars and islands; oc02.02: sinuous with multi-thread features; oc03.01: sinuous to meandering in the upper and middle parts, multi-thread with longitudinal bars in the lower part). channel width derives from maps on a 1:25.000 scale (empty circles) and from aerial photographs on various scales (full circles). b: variation of peak levels (h, thin line) and/or discharges (q, histogram) recorded at the pont canavese gauging station (617 km2 of drainage basin) up to 1979 and in 1993, at the cuorgnè gauging station (630 km2 of drainage basin) in 2000. il ruolo svolto da piene straordinarie ... ro suo percorso, riconquistando antichi spazi, acquisendone di nuovi e riproponendo in più punti il modello fluviale originario a più canali di deflusso obliterato da lungo tempo. è apparsa evidente la relazione tra intensità dei cambiamenti morfologici e necessità della corrente di adeguare forma e dimensione dell'alveo all'eccezionalità dell'apporto liquido e del carico solido messi in gioco in corso di evento (ri c h a r d s, 1982). infatti, nel caso dell'apporto liquido esso è stato nel 2000 superiore ad ogni massimo storico, come ricordato in precedenza, ed il carico solido è risultato abbondante per la capacità della corrente di autoalimentarsi con presa in carico di sedimenti dalle sponde e dal fondo, in condizioni, peraltro, di cessata attività estrattiva in alveo. in riferimento al prelievo di inerti, si sottolinea che, per valutarne l'impatto sul sistema e non disponendo di dati sulle concessioni, si è ricorsi all'analisi delle riprese aeree in visione stereoscopica. ne è emerso che le operazioni di prelievo, modestissime negli anni '50 e già molto diffuse negli anni '60, nel 1975 occupavano circa il 60% dell'alveo per profondità notevoli, anche se non quantificate. la situazione si è riproposta sulle riprese del 1980, mentre nel 1989 le attività apparivano molto ridotte in estensione, ma soprattutto in profondità, e condotte per lo più in prossimità degli impianti di lavorazione (tu r i t t o & au d i s i o, 2005). il cambiamento è attribuibile agli effetti della legge regionale del piemonte n. 69 del 22.11.1978, con cui veniva disciplinata l'attività estrattiva, prevedendo tuttavia ancora autorizzazioni, anche se con precise norme di conduzione. successivamente, con l'istituzione dell'autorità di bacino del fiume po (legge 183/89) le norme sui prelievi nelle fasce fluviali sono divenute molto restrittive, destinando le operazioni in alveo ai soli interventi di carattere manutentivo o di emergenza (bi a n c o, 1997). tali restrizioni hanno quindi consentito di preservare gran parte dei depositi in alveo negli anni di poco precedenti agli eventi di fine secolo. si ritiene che la rinnovata disponibilità di sedimenti sia stata particolarmente determinante nel 2000, in quanto la presenza di sabbie, ghiaie e ciottoli mobilizzati durante la precedente piena del 1993 e nella fase del post alluvione con profonda ed estesa movimentazione di sedimenti per operazioni di ricalibratura dell'alveo, di rimbottimento di sponde e di messa in sicurezza di beni pubblici e privati ha ancor più favorito la presa in carico, il trasporto e la ridistribuzione di elementi granulometrici eterogenei privi di coesione. alla luce di questi fatti è giustificato l'aspetto parossistico assunto da taluni processi di modellazione. tra le numerose situazioni emerse, sono state selezionate e vengono qui illustrate quelle ritenute rappresentative dei vari aspetti della dinamica di piena. la casistica proposta, riferita prevalentemente agli episodi del 1993 e del 2000, ma con occasionali riferimenti a quanto avvenuto negli stessi siti durante gli eventi del 1947 e del 1977, è suddivisa secondo il meccanismo prevalente che ha dato origine alle più significative modificazioni nella globale geometr ia d'alveo preesistente. l'ubicazione dei siti che compaiono nelle immagini a corredo del testo è indicata in figura 1. 3.1 riattivazione di rami secondari preclusi gli elevati livelli idrometrici raggiunti durante le piene del 1993 e del 2000 hanno permesso alle acque di imboccare e percorrere con estrema violenza ramificazioni periferiche attive nel xix secolo e da lungo tempo precluse con opere di sbarramento. è il caso mostrato in figura 4, in cui si nota un canale seconda308 fig. 4 località goritti di cuorgnè, deflusso verso destra. le frecce sottolineano il percorso seguito dalla corrente di piena nel 1993 (a) e nel 2000 (b) lungo un antico ramo di deflusso precluso a fine '800 per derivazioni a scopo industriale (c). the goritti site near cuorgnè, downflow to the right. the arrows indicate the direction followed by the flow during the 1993 (a) and 2000 (b) floods along an old branch closed off since the end of 1800s for industrial water use (c). o. turitto et al. 309 fig. 5 località rivarotta presso salassa, deflusso verso destra. aspetto dell'alveo nel 1975 (a), nel 1993 (b) e nel 2000 (c). gli intensi processi di erosione laterale innescati dalla piena del 2000 hanno provocato sensibili arretramenti di sponda rispetto alla situazione modellata dalla piena 1993; l'entità dello spostamento risulta di 200 m e 300 m in destra, di 90 m in sinistra idrografica (distanze misurate lungo le linee tracciate in b e c). sulle immagini sono evidenziati in tratteggio, come riferimento, i filari di alberi in destra e il campo in sinistra. the rivarotta site near salassa, downflow to the right. the pictures show the river course in 1975 (a), 1993 (b) and 2000 (c). severe bank erosion processes induced by the 2000 flood produced remarkable bank retreat compared with the bank position after the 1993 flood; the extent of bank retreat reached 200 m and 300 m on the right and 90 m on the left (distances measured along the lines in b and c). broken lines drawn on the pictures indicate rows of trees and a field as reference marks. rio in destra orco a monte dell'abitato di cuorgnè, sfruttato a fine '800 come derivazione a scopo industriale e già imboccato dalle acque di piena nel 1947 e nel 1948, con distruzione delle opere di presa. 3.2 erosione spondale l'energia della corrente ha in più punti prodotto consistenti erosioni di sponda con presa in carico di ingenti volumi di materiale. è il caso mostrato in figura 5, avvenuto nel 2000 presso la località rivarotta di salassa dove, per effetto dell'erosione laterale, sono stati misurati arretramenti di sponda fino ad alcune centinaia di metri. 3.3 apertura di nuovi canali di deflusso i violenti disalveamenti sulla piana inondabile hanno spesso innescato processi erosivi tali da dar luogo a un nuovo percorso periferico che, negli anni successivi, ha talora assunto il ruolo di canale di deflusso principale. è quanto avvenuto in località cascina bianco di salassa per la piena del 1947 con disalveamento e apertura di un nuovo ramo in sinistra (figg. 6a e 6b) che è divenuto col tempo la sola via di deflusso per progressivo abbandono del ramo di destra (figg. 6b e 6c). si può però notare che questo ramo abbandonato in destra è stato nuovamente imboccato dalla corrente durante la piena del 2000 (fig. 6d). 3.4 variazioni di fondo oltre ai cambiamenti morfologici riscontrati a livello planimetrico, i processi erosivi e deposizionali hanno indotto variazioni anche nella configurazione altimetrica dell'alveo. la sezione topografica rilevata prima e dopo la piena del 2000 presso la cascina bianco di salassa (fig. 6e) rappresenta un esempio dell'effetto producibile da tali processi. in alcuni casi questi meccanismi hanno portato ad una “inversione del profilo della sezione” (ma r a g a & mo r t a r a, 1977) per colmamento del canale dei deflussi ordinari e incisione di un nuovo canale spostato sul lato opposto dell'alveo. 3.5 accentuazione di anse alla fine degli anni '70, nel periodo di massima trasformazione del modello fluviale verso forme di transizione tendenti al monocursale con andamento sinuoso-meandriforme, l'effetto di piene straordinarie si è tradotto in una marcata accentuazione delle anse. ciò è il ruolo svolto da piene straordinarie ... 310 fig. 6 località cascina bianco di salassa, deflusso verso il basso. il ripetersi di occasionali disalveamenti in sponda sinistra (freccia in a) hanno portato durante la piena del 1947 all'attivazione permanente di un nuovo ramo (freccia in b), costretto nella sua posizione da una difesa costruita nel 1949 (difesa s. antonio in b). negli anni successivi questo ramo è diventato il canale di deflusso principale ed il ramo in destra è stato abbandonato (c). nel 2000 (d) le acque di piena hanno imboccato anche il ramo disattivato in destra, scalzando al piede il terrazzo di cascina bianco. sulla sezione topografica rilevata prima e dopo la piena del 2000 presso cascina bianco (x-y in e) si notano le variazioni di fondo alveo intervenute in corso di evento: in tonalità scure le aree di deposizione, in tonalità grigie quelle di asportazione (per gentile concessione dell'ing. aldo gervasio, piemontecnica-torino; scala originale delle lunghezze 1:2000 e delle altezze 1:200, riduzione del 73%). the cascina bianco site near salassa, downflow to the bottom. after recurrent overflowings on the left side of the river (arrow in a) the 1947 flood activated a new branch (arrow in b) controlled in its position by an embankment. afterwards the new branch on the left turned into the main channel and the old branch on the right was abandoned (c). during the 2000 flood (d) the water followed the left branch again, inducing severe bank erosion at the foot of the cascina bianco terrace. topographic cross-sections plotted near cascina bianco before and after the 2000 flood (x-y in e) show the altimetrical adjustments of river bed geometry induced by water flow: depositional areas are dark and erosional areas are grey (courtesy of ing. aldo gervasio, piemontecnica-torino; original horizontal scale 1:2000 and vertical scale 1:200, reduction of 73%). o. turitto et al. avvenuto nel settore medio-inferiore del tratto di pianura dell'orco, dove aveva preso avvio ed era in fase più avanzata la trasformazione fluviale (figg. 7a e 8b). in questo settore sono state eseguite misure in 16 siti dove, per effetto della sola piena del 1977, erano apparsi evidenti i processi di accentuazione di anse rispetto alla situazione ripresa nel 1975; gli arretramenti di sponda risultano oscillare più frequentemente su valori di 60÷80 m, con minimi di 40 m ed un unico massimo di 120 m. 3.6 formazione di nuove isole fluviali in alcuni settori le correnti idriche non contenute in alveo hanno attraversato ed eroso il piano campagna creando direttrici di deflusso lungo nuovi, recenti o antichi percorsi. nel 2000 tale meccanismo ha isolato parti della piana inondabile con conseguente formazione di isole fluviali. sono un esempio di questi effetti morfologici le immagini proposte nelle figure 5c, 6d e 7c dove emerge che, in diverso numero ed estensione, porzioni di territorio perifluviale sono entrate a far parte del nuovo alveo sottoforma di isola vegetata. 3.7 rimodellazione di un sistema di deflusso pluricursale attraverso i vari meccanismi descritti, le variazioni di forma e di dimensione del nuovo letto ricostruito dal corso d'acqua durante la sola piena del 2000 si sono localmente tradotte in un sensibile allargamento dell'alveo, accompagnato da una trasformazione del modello fluviale preesistente. ne sono un esempio le situazioni illustrate nelle figure 6, 7 e 8, che documentano una riconfigurazione dell'alveo con forme fluviali a più canali di deflusso, abbandonate in quelle località nella prima metà del '900. 4. discussione e considerazioni conclusive con il caso presentato si è voluto fornire un contributo conoscitivo sugli effetti parossistici che possono innescarsi in occasione di piene eccezionali, portando ad un drastico rimodellamento della geometria di un alveo per accentuate erosioni laterali, per violenta invasione della piana inondabile e per neoformazione di 311 fig. 7 confluenza orco-malesina presso foglizzo, deflusso verso il basso. sulle immagini riprese dopo le piene del 1977 (a), del 1993 (b) e del 2000 (c) è tracciato con linea bianca o nera l'andamento seguito dal corso d'acqua prima della piena. il modello fluviale sinuoso subentrato negli anni '70 è stato esaltato nel 1977 per accentuazione delle anse, ancora mantenuto nel 1993, ma obliterato dalla piena del 2000, che ha sensibilmente ampliato l'alveo e riproposto un modello fluviale a più canali di deflusso. la riattivazione di un antico ramo (freccia in c) ha trasformato una porzione della piana inondabile in isola fluviale. the orco-malesina confluence site near foglizzo, downflow to the bottom. on the aerial photographs taken after the 1977 (a), 1993 (b) and 2000 (c) floods the white or black lines show the position of the river course before the flood. the sinuous pattern established in the 1970s persisted during the 1977 flood (with a severe bank erosion due to the bend growth) and still during the 1993 one. whereas during the 2000 flood the river cancelled the sinuous pattern, leading again to a multi-thread configuration. the reactivation of a relic channel (arrow in c) isolated a floodplain portion, transforming it into a fluvial island. il ruolo svolto da piene straordinarie ... rami secondari o riattivazione di quelli abbandonati nel passato. è stato documentato come durante la piena del 2000 tali processi abbiano riproposto anche solo localmente e forse solo temporaneamente il modello fluviale originario a più canali di deflusso, obliterato da tempo per cause naturali o per motivi antropici. dagli studi condotti è emerso come la configurazione d'alveo imposta al torrente orco negli anni '70 e '80 del secolo scorso (stretto canale di deflusso ad andamento sinuoso-meandriforme) abbia indotto a un falso concetto di sicurezza, suggerendo condizioni di equilibrio dinamico duraturo. l'indagine storica, basata su una lunga serie di documentazione multitemporale e sulla lettura delle forme fluviali presenti sul territorio a testimonianza dei percorsi abbandonati nel passato, hanno invece permesso di capire che quella configurazione d'alveo era stata in gran parte artificialmente indotta e non corrispondeva pertanto alle reali potenzialità dinamiche del corso d'acqua. nel produrre le sensibili modificazioni nel letto fluviale, è apparsa determinante l'intensità dei processi di erosione spondale, unitamente alla rinnovata disponibi312 fig. 8 località cascina mure presso san benigno, deflusso verso il basso. il modello fluviale di inizio anni '60 (a) appare in trasformazione verso forme monocursali sinuose, sottolineate dalla presenza di una grande ansa (freccia). sulle riprese successive, scattate dopo le piene del 1977 (b), del 1993 (c) e del 2000 (d), è tracciato con linea bianca o nera l'andamento seguito dal corso d'acqua prima della piena. dopo il taglio della grande ansa del 1961, avvenuto a fine anni '60, la piena del 1977 ha notevolmente accentuato le sinuosità a monte del taglio (frecce in b). la piena del 1993 (c) non ha modificato molto questo andamento, mentre la piena del 2000 (d) ha sensibilmente ampliato l'alveo, impostando un sistema articolato in più canali di deflusso. the cascina mure site near san benigno, downflow to the bottom. in the beginning of the 1960s (a) the fluvial pattern was going to change into the single-thread configuration, with a large bend (arrow). on the following aerial photographs taken after the 1977 (b), 1993 (c) and 2000 (d) floods the white or black lines show the position of the river course before the flood. after the cut-off of the 1961 bend, occurred at the end of 1960s, the 1977 flood increased the river sinuosity upstream the cut-off (arrows in b). during the 1993 flood (c) the channel configuration was not much modified, but after the 2000 flood (d) the river channel appeared considerably widened and transformed into the old multi-thread system. o. turitto et al. lità di materiale alluvionale in alveo (per cessazione del prelievo incontrollato) che le notevoli portate in transito sono state comunque in grado di ridistribuire con diffusi processi di presa in carico, di trasporto e di deposito. anche in occasione della piena del 1947 (1410 m3/s, la massima storica prima del 1993), avvenuta in condizioni di disponibilità di sedimenti per assenti o scarsissimi prelievi di inerti, si è prodotto un rimodellamento delle forme fluviali con ampliamento dell'alveo nel settore intermedio del percorso analizzato, dove era ancora sviluppato il modello a più canali di deflusso. ciò è emerso dal confronto delle riprese aeree precedenti (1945) e successive (1954) all'evento (cfr. ampiezza 1945 e 1954 dei tratti oc02.01 e oc02.02 in fig. 3a) e supportato da documenti d'archivio. per contro, nello stesso settore ma in periodo di massimo approvvigionamento di inerti ed in presenza di un unico canale ad andamento sinuoso in fase di incisione, la piena del 1977 (valutata intorno a 1300 m3/s) non ha dato luogo a significativi fenomeni di ampliamento dell'alveo, ma ad un'accentuazione delle anse presenti (cfr. figg. 7a e 8b). è ragionevole supporre che ciò sia avvenuto a seguito di un deficit di carico solido, compensato con autoalimentazione a scapito delle sponde concave del percorso sinuoso, associato ad una maggior capacità contenitiva del canale di deflusso soggetto ad erosione di fondo per gli intensi e incontrollati prelievi di sabbie e ghiaie. si ritiene pertanto che questi diversi effetti morfologici prodotti lungo l'orco dagli eventi del 1947 e del 1977 con elevati valori di portata registrati alla stessa stazione di misura, ma in differente contesto di gestione dei sedimenti in alveo pongano ulteriormente in evidenza due aspetti: la capacità delle piene nel rimodellare forme fluviali secondo una tipologia d'alveo a più canali di deflusso, se ai volumi idrici si associa una disponibilità di sedimenti da movimentare (come nel 1947 e nel 2000); l'interferenza operata dall'uomo sulle morfodinamiche di piena, privando il sistema di un elemento fondamentale quale il carico solido (come nel 1977). tale ultimo aspetto è stato peraltro ricorrentemente richiamato in molti lavori, tra cui quelli citati in introduzione, come concausa o addirittura causa prevalente dei rapidi processi di restringimento e incisione degli alvei osservati tra gli anni '60 e '80 del secolo scorso. sotto questo aspetto, quindi, si può affermare che quanto avvenuto in orco in quei decenni rispecchi con buona contemporaneità e analogia di effetti e cause quanto avvenuto in numerosi corsi d'acqua della rete idrografica nazionale. anche il fenomeno di allargamento della sezione d'alveo, che ha riguardato l'orco dopo gli anni '80, è stato segnalato pressoché contemporaneamente in buona parte dei corsi d'acqua recentemente indagati nell'italia centro-settentrionale, proprio in concomitanza dell'applicazione di norme più restrittive in materia di estrazione di inerti (surian et al., 2008). il valore di allargamento è stato tuttavia più elevato in orco, rispetto agli altri casi analizzati, per il carattere di singolarità derivato dal manifestarsi della piena estrema del 2000. va infine sottolineato che negli anni futuri, in assenza di eventi eccezionali confrontabili con quelli di fine secolo, l'assetto planimetr ico modellato dal torrente orco nel 2000 potrà essere rielaborato per dare nuove forme di equilibrio dinamico, in funzione delle portate in transito e della disponibilità di materiale in alveo, ferma restando una situazione di erodibilità delle sponde (pi é g a y et al., 2005; su r i a n & ci s o t t o, 2007). gli elementi fluviali periferici ubicati a quote maggiori potranno essere risparmiati da violente correnti e solo occasionalmente sommersi dalle acque con modesti battenti. ne potrà derivare col tempo una loro mancata connessione con il canale di deflusso principale, una rapida colonizzazione da parte della vegetazione ed una progressiva esclusione dall'ambito dell'alveo, riducendone in qualche misura i valori di larghezza globale raggiunti dopo la piena del 2000. a tal proposito si fa rilevare che recenti verifiche effettuate sulle ortofotocarte del 2006 lungo un tratto campione di circa 2 km presso il ponte di feletto hanno fatto registrare un valore di larghezza dell'alveo inferiore a quello del 2003 (-27%), tuttavia ancora superiore a quello del 1989 (+11%). anche se nel prosieguo delle indagini verrà confermata sull'intero percorso indagato una generale tendenza alla riduzione della notevole larghezza d'alveo raggiunta nel 2000, ai fini di una cautelativa gestione degli ambiti fluviali occorrerà sicuramente tener conto degli spazi necessari alla “funzionalità della dinamica evolutiva del corso d'acqua” e fondamentali per la “tutela della biodiversità acquatica e ripariale” (autorità di bacino del fiume po, 2000), senza tuttavia sottovalutare i possibili effetti di futuri eventi di piena estremi. ringraziamenti ricerca iniziata nel l'ambito del progetto “monitoraggio e manutenzione del fiume orco” promosso dalla regione piemonte-direzione difesa del suolo (responsabile scientifico: ing. giorgio lo l l i n o del cnr-irpi di torino) e proseguita con fondi del progetto miur-prin 2005 “dinamica recente e attuale di alvei fluviali nell'italia centro-settentrionale: tendenze evolutive, cause ed implicazioni appl icative” (responsabile nazionale: dott. nicola su r i a n dell'università di padova; responsabile locale: dott.ssa luisa pellegrini dell'università di pavia). si ringraziano gli anonimi revisori per gli utili commenti e suggerimenti, nonché il prof. daniel hartley per la revisione delle parti di testo in lingua inglese. i fotogrammi a corredo del testo sono stati resi liberi per gli usi consentiti dalla legge (d.p.r. 367 del 29.09.2000). bibliografia andrews e.d. (1980) effective and bankfull discharges of streams in the yampa river basin, colorado and wyoming journal of hydrology, 46(3/4), pp. 311-330. aucelli p.p.c. & rosskopf c. (2000) last century valley floor modifications of the trigno river (southern italy): a preliminary report geografia fisica e dinamica quaternaria, 23, pp. 105-115. autorità di bacino del fi u m e po (1995) c a r a t t e r i zzazione geometrica, geomorfologica ed idraulica del reticolo idrografico delle aree soggette ad alla313il ruolo svolto da piene straordinarie ... g a m e n t o attività 2 della fase 1a (stralcio piemonte) del sottoprogetto sp1 (piene e naturalità alvei fluviali), parma. autorità di bacino del fiume po (2000) piano stralcio delle fasce fluviali-relazione parma, 143 pp. bezoari g., braga g., gervasoni s., larcan e. & paoletti a. (1984) effetto dell'estrazione di inerti sull'evoluzione dell'alveo del fiume trebbia atti del 2° convegno di idraulica padana, parma, 15-16 giugno 1984, parte ii, pp. 163-182. bianco g. (1997) attività estrattiva nelle fasce di pertinenza fluviale atti della giornata di studio su “aspetti tecnici e normativi nell'estrazione di inerti e pietre calcaree per uso industriale”, torino, 13 novembre 1997, politecnico di torino, pp. 61-67. bi g g i e r o v., fi o r e n t i n o m. & pi a n e s e d. (1994) evoluzione d'alveo del fiume volturno xxiv convegno di idraulica e costruzioni idrauliche, vol. ii, t4, pp. 233-246. brice j.c. (1964) channel patterns and terraces of the loup rivers in nebraska geological survey professional paper 422-d, 41 pp. canuti p., cencetti c., conversini p., rinaldi m. & tacconi p. (1992) dinamica fluviale recente di alcuni tratti dei fiumi arno e tevere atti del convegno “fenomeni di erosione e alluvionamenti degli alvei fluviali”, università di ancona, 14-15 ottobre 1991, pp. 21-35. ca s t a l d i n i d., pi a c e n t e s. & ma l m u s i s. (1999) evoluzione del f. secchia in pianura nel xix e nel xx secolo (province di reggio emilia, modena e mantova, italia settentrionale) in: or o m b e l l i g . (ed.) studi geografici e geologici in onore di severino belloni, brigati, genova, pp. 169-187. ca s t i g l i o n i g.b. & pe l l e g r i n i g.b. (1981) geomorfologia dell'alveo del brenta nella pianura tra bassano e padova in: zunica m. (ed.) il territorio della brenta, amministrazione provinciale di padova e università di padova, pp. 12-32. co l t o r t i m., na n n i t. & vi v a l d a p. (1991) la bassa valle del fiume musone (marche): geomorfologia e fattori antropici nell'evoluzione della pianura alluvionale geografia fisica e dinamica quaternaria, 14, pp. 101-111. dutto f. & maraga f. (1994) variazioni idrografiche e condizionamento antropico. esempi in pianura padana il quaternario, 7(1), pp. 381-390. eu r o p e a n en v i r o n m e n t ag e n c y (2004) impacts of europe's changing climate, an indicator-based assessment eea report n. 2/2004, copenhagen, 100 pp. gentili b. & pambianchi g. (1987) morfogenesi fluviale e attività antropica nelle marche centro-meridionali geografia fisica e dinamica quaternaria, 10, pp. 204-217. go v i m. (1976) ricerche sui processi di riattivazione delle capacità erosive negli alvei dei torrenti stura di lanzo e orco la ricerca scientifica, 46(2), pp. 332-334. govi m. & turitto o. (1993) processi di dinamica fluviale lungo l'asta del po acqua aria, 6, pp. 575588. le b e n s m i n i s t e r i u m (2006) cambiamenti climatici nella regione alpina: conseguenze e sfide wien, 43 pp. maraga f. (1989) ambiente fluviale in trasformazione: l'alveo-tipo pluricursale verso un nuovo modellamento nell'alta pianura padana proceedings of the iv geoengineering international congress “suolosottosuolo”, turin, 27-30 september 1989, 1, pp. 119-128. maraga f. & mortara g. (1977) modificazioni dell'alveo e trasporto solido al fondo nel t. pellice in riferimento alla piena del 19-20 maggio 1977 atti del congresso “misura del trasporto solido al fondo nei corso d'acqua: problemi per una modellistica matematica”, firenze, 13-14 ottobre 1977, c2, pp. 1-16. maraga f. & mortara g. (1981) le cave di inerti lungo i corsi d'acqua: rapporti con la dinamica fluviale bollettino dell'associazione mineraria subalpina, 18(3-4), pp. 385-395. ma r c h e t t i m. (2002) environmental changes in the central po plain (northern italy) due to fluvial modifications and anthropogenic activit ies geomorphology, 44, pp. 361-373. me r c a l l i l. & ca t be r r o d. (2005) climi, acque e ghiacciai tra gran paradiso e canavese società meteorologica subalpina, bussoleno (to), 755 pp. pellegrini l., maraga f., turitto o., audisio c. & duci g. (2008) evoluzione morfologica di alvei fluviali mobili nel settore occidentale del bacino padano (in questo volume). pe l l e g r i n i m., pe r e g o s. & ta g l i a v i n i s. (1979) l a situazione morfologica degli alvei affluenti emiliani del po estratto dagli atti del convegno di idraulica padana, parma, 19-20 ottobre 1979, 9 pp. piégay h., darby s.e., mosselman e. & surian n. (2005) a review of techniques available for delimiting the erodible river corridor: a sustainable approach to managing bank erosion river research and applications, 21, pp. 773-789. richards k. (1982) rivers: form and process in alluvial channels methuen, london, 358 pp. rinaldi m. (2003) recent channel adjustments in alluvial rivers of tuscany, central italy earth surface processes and landforms, 28, pp. 587-608. ri n a l d i m. & ro d o l f i g. (1995) evoluzione olocenica della pianura alluvionale e dell'alveo del fiume sieve nel mugello (toscana) geografia fisica e dinamica quaternaria, 18, pp. 57-75. rinaldi m. & simon a. (1998) bed-level adjustment in the arno river, central italy geomorphology, 22(1), pp. 57-71. ri n a l d i m., wy z g a b. & su r i a n n. (2005) s e d i m e n t mining in alluvial channels: physical effects and management perspectives river research and applications, 21, pp. 805-828. ro g o r a m., ar i s c i s. & mosello r. (2004) r e c e n t trends of temperature and precipitation in alpine and subalpine areas in north western italy geografia fisica e dinamica quaternaria, 27, pp. 151-158. sa b a t o l. & tr o p e a n o m. (2004) fiumara: a kind of high hazard river physics and chemistry of the earth, 29(10), pp. 707-715. so c i é t é hydrotecnique de fr a n c e (2004) étiages et crues extrêmes régionaux en europe: perspectives historiques colloque d'hydrotechnique, 314 o. turitto et al. lyon, 28-29 janvier 2004, 166 pp. surian n. (1999) channel changes due to river regulation: the case of the piave river, italy earth surface processes and landforms, 2 8, pp. 587608. surian n. (2006) effects of human impact on braided river morphology: examples from northern italy. in: sa m b r o o k sm i t h g.h., be s t j.l., br i s t o w c.s. & pe t t s g.e. (eds.) braided rivers: process, deposits, ecology and management, blackwel publishing, pp. 327-338. su r i a n n. & ci s o t t o a. (2007) channel adjustment, bedload transport and sediment sources in a gravel-bed river, brenta river, italy earth surface processes and landform, 32, pp. 1641-1656. su r i a n n., pe l l e g r i n i g.b. & sc o m a z z o n e. (2005) variazioni morfologiche dell'alveo del fiume brenta indotte da interventi antropici geografia fisica e dinamica quaternaria, suppl. vii, pp. 339-345. surian n. & rinaldi m. (2003) morphological response to river engineering and management in alluvial channels in italy geomorphology, 5 0, pp. 307326. surian n. & rinaldi m. (2004) channel adjustments in response to human alteration of sediment fluxes: examples from italian rivers proceedings of a symposium “sediment transfer through fluvial system”, moscow, august 2004, iahs pubbl. n. 288, pp. 276-282. surian n., rinaldi m., pellegrini l., audisio c., maraga f., te r u g g i l., tu r i t t o o. & zi l i a n i l. (2008) channel adjustment in northern and central italy over the last 200 years (in stampa su geological society of america special paper). thorne c.r. (1997) channel types and morphological c l a s s i f i c a t i o n in: th o r n e c.r., he y r.d. & ne ws o n m.d. (eds.) applied fluvial geomorphology for river engineering and management, wiley, chichester, pp. 175-222. turitto o. & audisio c. (2005) analisi dei motivi naturali e antropici all'origine di modificazioni planimetriche riscontrate lungo l'alveo del torrente orco negli ultimi due secoli convenzione tra regione piemonte-direzione difesa del suolo e cnr-irpi di torino nel l'ambito del programma “monitoraggio e manutenzione del fiume orco”, cnr-irpi torino, r.i. 05/36, 61 pp. turitto o. & audisio c. (2008) ponti e dinamica fluviale: effetti di reciproca interferenza l'acqua, 2/2008, pp. 7-16. 315 ms. ricevuto il 29 novembre 2007 testo definitivo ricevuto il 18 aprile 2008 ms. received: november 29, 2007 final text received: april 18, 2008 il ruolo svolto da piene straordinarie ... riduzione del trasporto solido fluviale e modificazioni della linea di riva tra le foci del vomano e del pescara: trend storico recente carlo manzo arpa piemonte e mail: c.manzo@arpa.piemonte.it riassunto: manzo c.: riduzione del trasporto solido fluviale e modificazioni della linea di riva tra le foci del vomano e del pescara: trend storico recente (it issn 0394-3356, 2008). principale obiettivo del presente lavoro è l'analisi dell'evoluzione storica recente della linea di costa compresa tra le foci del fiume vomano e del fiume pescara (abruzzo medio adriatico), focalizzandone i nessi con l'apporto solido fluviale. come già evidenziato da diversi aa. l'erosione costiera nella zona del medio adriatico ha interessato soprattutto le zone prospicienti alle foci fluviali a causa del deficit sedimentario determinato in gran parte dall'impatto delle attività umane nei bacini idrografici. il presente studio in effetti conferma questo quadro, mettendo in rilievo il potenziale contributo del clima ed in particolare delle variazioni del regime pluviometrico. tralasciando una dettagliata caratterizzazione di alcuni aspetti pure importanti negli studi di dinamica costiera, quali il clima di moto ondoso, la batimetria e le proprietà fisico-sedimentologiche della spiaggia, l'attenzione è stata focalizzata sulle informazioni che si possono trarre dall'andamento planimetrico delle linee di riva successive. e' stata ricostruita una serie storica delle linee di riva che copre all'incirca gli ultimi 200 anni, attraverso la georeferenziazione di mappe storiche e foto aeree. la serie storica ottenuta è stata utilizzata per avere una stima dell'andamento del bilancio sedimentario netto, moltiplicando il tasso di variazione dell'area costiera per lo spessore di spiaggia interessata da movimento sedimentario significativo. i risultati mostrano come nel corso dell'800 la linea di riva fosse inizialmente piuttosto rettilinea, successivamente con tendenza all'aumento della prominenza delle foci fluviali, con un netta tendenza all'avanzamento ed un elevato bilancio sedimentario positivo. tale tendenza cambia agli inizi del '900, parallelamente ad una pressione crescente delle attività umane nei bacini idrografici: il bilancio sedimentario netto era circa nullo tra il 1920 ed il 1940 e diviene negativo, con trend piuttosto costante, a partire dagli anni '40. in questa ultima fase, che si protrae fino ad oggi, si rileva una marcata tendenza all'arretramento nelle zone di delta. per quest'ultimo periodo è stato implementato un modello matematico semplificato “ad una linea”, con lo scopo di identificare il comportamento generale della dinamica costiera con particolare riferimento ai termini di ingresso sedimentario attraverso il trasporto solido fluviale e alle perdite verso li largo. il modello utilizzato si basa su una soluzione alle differenze finite dell'equazione di diffusività alle derivate parziali, che descrive le variazioni della linea di riva nel tempo. e' stato effettuata un'analisi inversa al fine di tarare il modello sulla base del bilancio sedimentario e delle posizioni successive delle linee di costa ricostruite. sotto l'ipotesi di un bilancio sedimentario costante il modello rileva che con buona probabilità l'arretramento della linea di costa, che finora ha interessato principalmente le zone deltizie, tenderà a propagarsi progressivamente verso le zone interdeltizie. nonostante il modello utilizzato non sia completamente realistico, può essere considerato un giusto compromesso in grado di riprodurre a grandi linee la realtà fisica del fenomeno, costituisce una base di partenza per ulteriori studi ed osservazioni e per testare criticamente le ipotesi inizialmente fatte. i risultati ottenuti sono parzialmente osservabili e mettono in rilievo un modello concettuale che, anche potendo essere ulteriormente affinato, costituisce un contributo alla comprensione della dinamica costiera di quest'area, strettamente correlata al trasporto solido fluviale. abstract: manzo c.: reduction of river sediment transport and shoreline modifications between vomano and pescara river mouths: late historical trend (it issn 0394-3356, 2008). the main purpose of the study is the coastline evolution analysis of the stretch situated between vomano and pescara river outlets (middle adriatic sea, abruzzo, italy), focusing on the relationships between river sediment transport and coastline evolution. many authors suggest that erosion in the middle adriatic area mainly took place on the river deltas as an effect of sedimentary deficit due to human activities in the river basins. the present work confirm such a description, highlighting the relationships of coastal evolution both to social-economic aspects (impact of human activities in the river basins) and to climate (variability of annual rainfall). leaving out a detailed characterizations of some important factors conditioning coastal dynamics, such as wave motion, bathymetry and physical-sedimentological properties of the beach, the study is focused on the planform analysis of subsequent coastlines shapes and positions. historical maps and aerial photographs covering the last two centuries were georeferenced with the aim to reconstruct a time series of multiple shoreline positions. therefore the course of sedimentary budget was obtained multiplying the rate of coastal area variation by the depth of appreciable send movement. in the first part of xix century the coastline appeared quite rectified with small delta cusps protrusion. the second half of the xix century reveals high delta protrusion and high sedimentary budgets. this trend became to change at the beginnings of xx century with the increment of human activities in the river basins: the sedimentary budget was about zero from 1920 till 1940 and it tends to become quite constant negative beginning from 1940, with strong erosion of river deltas. such long-term trend allowed to implement a simplified one-line model, with the aim to identify a general coastal behaviour related to river inputs and seaward sedimentary losses. the model used is based on a finite differences solution of the diffusivity differential equation, describing the shoreline variations vs. time. a back analysis was made in order to get the best fitting of the phenomenon, using the sedimentary balance and the time series of multiple shoreline positions as the input calibrating information. assuming that the rate of sedimentary balance will remain constant, the future scenario predicted by the model reveal that erosion will tend to involve more and more sectors progressively. even if such simplified model is not completely realistic, it seems to be a successful balance between realism and practicality, it can direct further studies and observations and help to critically test hypothesis. actually the results are partially observable. such results show a conceptual model which should lead to further studies, though it can be considered a contribution to the comprehension of behaviour of this coastal tract, whose dynamics are strongly related to river sediment transport. parole chiave: linea di riva, erosione, tendenza evolutiva, bilancio sedimentario, trasporto solido fluviale, vomano, pescara, saline, italia keywords: shoreline, erosion, trend, sedimentary budget, river sediment transport, vomano, pescara, saline, italy il quaternario italian journal of quaternary sciences 21(1b), 2008 193-206 194 c. manzo 1. introduzione il tratto costiero oggetto del presente lavoro, posto tra le foci dei fiumi vomano e pescara, così come gran parte del settore costiero italiano adriatico, è interessato da una tendenza all'arretramento in presenza di zone densamente urbanizzate. in quest'area la presenza di spiagge ampie e sabbiose costituisce una risorsa preziosa per il settore turistico e per la protezione degli insediamenti retrostanti. nel danno economico dovuto al processo erosivo è stata determinante la non corretta gestione del territorio: una forte urbanizzazione ha avuto luogo senza tenere in debita considerazione la forte dinamicità dei processi morfogenetici fluvio-costieri. gli sforzi fatti dalle amministrazioni locali per contrastare il fenomeno si sono basati principalmente nella realizzazione di scogliere emerse parallele alla costa che, nonostante la loro efficacia nel contrastare l'erosione a livello localizzato, hanno fortemente deteriorato il paesaggio e le caratteristiche qualitative del sedimento e delle acque in prossimità della riva. la ricostruzione dell'evoluzione storica recente della linea di costa permette di ricavare importanti informazioni riguardo il bilancio sedimentario e l'apporto solido fluviale che ne rappresenta il termine positivo principale, ma anche sull'efficacia delle azioni di mitigazione del fenomeno erosivo che si sono succedute nel tempo. 2. contesto geologico-geomorfologico la fascia costiera abruzzese è costituita da una sottile area pianeggiante delimitata dai retrostanti rilievi collinari prevalentemente argillosi plio-pleistocenici e formatasi nella fase finale della trasgressione flandriana (olocene), attraverso la progradazione degli apparati di foce e degli ambienti deposizionali costieri a questi strettamente connessi (fig.1). la redistribuzione del trasporto solido fluviale attraverso il trasporto litoraneo lungo-costa ha portato alla formazione di cordoni sabbiosi e aree palustri retrostanti, su cui successivamente sono sorte estese aree urbanizzate. l'area in oggetto è delimitata a nord dall'apparato di foce del fiume vomano e a sud dalla foce del pescara, su cui sorge l'omonimo porto-canale. l'apporto sedimentario è principalmente derivante dai maggiori corsi d'acqua afferenti (fiumi vomano, saline, e pescara) i cui bacini idrografici drenano, nella zona interna, formazioni affioranti di tipo carbonatico (piattaforma carbonatica laziale-abruzzese), mentre nella parte media e finale incidono principalmente terreni sabbiosi ed argillosi (depositi terrigeni dell'avanfossa peri-adriatica). vi sono inoltre bacini idrografici minori che drenano i rilievi collinari, in particolare quello del torrente calvano, che sfocia presso l'abitato di pineto, quello del torrente cerrano, e quello del piomba, la cui foce è posta poche centinaia di metri a nord della foce del saline. 2.1 caratteristiche geomorfologiche e sedimentarie del tratto costiero il tratto costiero è caratterizzato prevalentemente da un'ampia spiaggia di sabbia fine-finissima. fanno eccezione le zone di foce del vomano e del saline, presso cui la spiaggia si presenta sottile e prevalentemente ghiaioso-ciottolosa. in questi ultimi tratti sono presenti forme tipiche associate all'azione erosiva del moto ondoso quali gradini erosivi, berme ghiaiose ad elevata pendenza ed affioramenti di limi coesivi di retrospiaggia (figura 5). la linea di costa è piuttosto rettilinea con le uniche blande irregolarità costituite dagli apparati di foce e dal piccolo promontorio su cui sorge la torre di cerrano, dove per un breve tratto la fascia pianeggiante scompare del tutto e le argille plio-pleistoceniche affiorano in prossimità della spiaggia. in base alla situazione descritta è possibile distinguere due differenti sub-unità fisiografiche (di seguito indicate come unità fisiografiche): una a nord, delimitata dalle foci del vomano e del saline, ed una a sud, compresa tra la foce del saline ed il porto di pescara. il moto ondoso assume una direzione regnante da s/se ed una direzione secondaria da n/ne: si hanno quindi due componenti opposte del flusso energetico longitudinale del moto ondoso. questo fa sì che le blande prominenze deltizie siano determinanti nell'influenzare la deriva sedimentaria longitudinale netta (fig. 1). delle due unità fisiografiche quella posta a sud ha caratteristiche di più alto grado di antropizzazione, essendo compresa in un contesto urbano ed interamente protetta da barriere emerse distaccate realizzate a partire dagli anni '70 '80. questo tratto presenta una spiaggia generalmente molto ampia (con punte massime di circa 200 m in corrispondenza della zona nord di pescara) le cui caratteristiche paiono però alterate dal forte grado di protezione. nella zona meno antropizzata, nell'unità fisiografica nord, si riscontrano alcune differenze di tipo morfologico tra i tratti posti in prossimità delle foci e quelli inter-foce. questi ultimi presentano pendenze della spiaggia sommersa molto blande con 3-4 ordini di barre sabbiose, e una spiaggia emersa ampia (larghezze perlopiù comprese tra i 40 e i 100 m). i tratti deltizi sono invece caratterizzati da pendenze più accentuate con 1 o 2 ordini di barre e spiagge ghiasioso-ciottolose sottili (dal cin, simeoni,1987; simeoni, 1989). tali differenze di tipo gemorfologico e sedimentario riflettono il diverso comportamento dei tratti deltizi, caratterizzati da spiccata tendenza all'arretramento, dai tratti interdeltizi, stabili o in lento avanzamento. 3. la diminuzione del trasporto solido fluviale 3.1 fattori antropici l'attuale tendenza erosiva è attribuita in maniera piuttosto concorde da diversi autori alle attività umane nei bacini idrografici, quali le escavazioni in alveo, la reatab. 1 superficie dei bacini idrografici. area of hydrograph basins. bacino vomano calvano cerrano piomba saline pescara superficie (km2) 786 39 26 109 612 3169 lizzazione di invasi artificiali e traverse, l'irrigidimento delle aste fluviali, che hanno fortemente diminuito il trasporto solido di fondo dei corsi d'acqua (ad a m o l i, 1991; ad a m o li, 1994; pa r e a, 1978). in diversi tratti delle aste fluviali abruzzesi, specialmente in quelli medio-terminali, l'alveo attivo si trova a scorrere direttamente sul substrato costituito dalle argille grigio-azzurre, avendo inciso per erosione lineare il materasso alluvionale soprastante. questa situazione, unitamente alla presenza di fenomeni di a r m o u r i n g del letto, determina verosimilmente uno squilibrio del trasporto solido di fondo nei tratti di alveo posti a valle delle opere di ritenuta o delle aree di estra195riduzione del trasporto solido fluviale ... zione di ghiaia e sabbia (bu c c o l i n i, ti b e r i o, 2001). alcuni dei fattori antropici indicati come causa del disequilibrio dei corsi d'acqua possono essere supportati da documentazione riguardante i volumi prelevati in alveo, principalmente negli anni '50, '60 e '70. la tabella sottostante sintetizza le informazioni a riguardo tratte da uno studio condotto da aquater per conto della regione abruzzo nel 1982, da cui si può avere un'idea di come i prelievi effettuati nel periodo tra il 1966 ed il 1975 siano stati superiori al trasporto solido potenziale dei corsi d'acqua nei rispettivi tratti terminali. al fine di quantificare l'impatto dovuto alle instalfig 1. schema geologico e principali caratteri geomorfologici del tratto di costa tra i fiumi vomano e pescara. geological sketch and main geomorphologic aspects of the coast tract between vomano and pescara rivers. bacino periodo volumi asportati estrazione media annua intervallo di trasporto solido di (m3) (m3) fondo potenziale (m3/anno) vomano 1966 1975 3187904 318790 55000 100000 saline 1966 1975 1889263 188926 55000 100000 pescara 1966 1975 2831733 283173 190000 390000 tab. 2 lazioni idroelettriche e agli invasi artificiali connessi si può fare invece riferimento alla diminuzione dei volumi di invaso a causa dell'interramento. la prima insta llazione idroelettrica, realizzata alla fine degli anni '40 nel medio corso del fiume pescara, ha indotto un tasso di interramento medio di circa 32.000 m3 annui all'interno di 4 invasi artificiali della capacità complessiva di circa 107 m3. sul fiume tavo-saline fu invece realizzato nel 1969 il lago di penne: la capacità di invaso iniziale di 10,6*106 m3 risulta attualmente diminuita a circa 8,8*106 m3. sull'alto corso del vomano e sul mavone, suo principale affluente, sono stati realizzati tre invasi artificiali agli inizi degl i anni '50 con una capacità complessiva di circa 3 2 0 * 1 06 m3, dei quali non sono disponibi li informazioni sul tasso di interramento. risulta inoltre alterato l'originario bacino imbrifero dalla realizzazione di canali di gronda situati a varie quote e centrali di pompaggio per il riutilizzo dell'acqua tra un serbatoio e l'altro (tei, regione abruzzo, 1986). 3.2 fattori climatici il fenomeno della diminuzione del trasporto solido fluviale è da correlare con molta probabilità anche alla variabilità climatica. sulla base della ricostruzione di alcune serie storiche delle precipitazioni totali annue si possono individuare possibili connessioni con l'evoluzione degli alvei e della linea di costa. sono state utilizzate le serie storiche ricavate dalle registrazioni delle stazioni pluviometriche di chieti ed atri (la prima parte dal 1868 mentre la seconda dal 1922), da considerarsi piuttosto rappresentative per l'area in oggetto. tali serie cronologiche rispecchiano a grandi linee l'andamento generale italiano (fa n t u c c i e ma r g o t t i n i, 1996) sia nel t r e n d c h e nelle oscillazioni di breve durata. un periodo particolarmente piovoso ha interessato la seconda metà dell'800 ed i primi due decenni del '900, seguito da un decennio più secco. a questo è seguito un breve periodo umido tra il 1930 ed il 1940 ed un periodo secco protrattosi fino ad oggi. in figura 3 è riportata la serie storica delle precipitazioni annue registrate dalla stazione di chieti e la relativa media mobile di passo 7 anni. e' chiaramente individuabile un andamento oscillatorio smorzato con trend generale decrescente a partire dal 1920 circa. i principali effetti degli interventi antropici nei bacini idrografici e della diminuzione delle precipitazioni annue si sono probabilmente sovrapposti nello stesso periodo temporale e ne risulta dunque difficoltosa una quantificazione separata. inoltre non sono disponibili informazioni riguardanti il cambiamento dell'uso del suolo e in generale della copertura vegetale dei bacini idrografici, fattore che con buona probabilità ha contribuito alla variazione di produzione di sedimento e del conseguente apporto solido alla costa. le immagini di fig. 3 ritraggono alcune evidenze di incisione lineare nell'alveo del fiume fino, compreso nel bacino idrografico del saline, in un tratto posto a circa 9 km dalla foce: sono evidenti i fenomeni di sottoescavazione di una briglia e di un plinto realizzato per l'attraversamento di un metanodotto. sulla base della data di realizzazione del metanodotto si può stimare un tasso di approfondimento dell'alveo di circa 7-8 cm/anno. 4. altre cause nel tratto in oggetto possono aver giocato un ruolo nell'evoluzione della linea di riva ulteriori fattori individuabili essenzialmente nell'innalzamento tettonico, nell'innalzamento eustatico e nelle variazioni nel tempo dell'energia e delle caratteristiche del moto ondoso . l'innalzamento tettonico è stato valutato per l'area in questione in circa 0,5 mm/anno (carobene, 2004), e può essere considerato di importanza secondaria rispetto al deficit sedimentario di apporto solido nella scala temporale caratteristica dello studio in oggetto. da un punto di vista concettuale tale fattore determinerebbe un avanzamento della linea di riva piuttosto che 196 fig 2. serie cronologica delle precipitazioni annue anni relativa alla stazione meteo-pluviometrica di chieti con media mobile di passo 7 (1867-1994). annual rainfall time series whit 7 years moving average, chieti meteo-pluviometer observation data (1867-1994). fig. 3. evidenze del disequilibrio dell'alveo del fiume fino, nei pressi della confluenza con il saline e a circa 9 km dalla foce: sottoescavazione di una briglia (a )e di un plinto (b). deepening of the fino riverbed, near its confluence with saline about 9 km far from the outlet: dam under excavation (a); current erosive action on a plinth (b). c. manzo un arretramento, sebbene possa indurre fenomeni di incisione lineare nei corsi d'acqua o morfologie erosive sulla costa. ma le evidenze osservate, che consistono principalmente nell'arretramento della costa e nell'incisione lineare dei corsi d'acqua, non concordano con tale modello. l'innalzamento eustatico può essere determinato dai ben noti mutamenti climatici legati al riscaldamento globale. verosimilmente tale fattore potrà giocare un ruolo importante in scenari futuri che vedono sensibili innalzamenti del livello medio del mare, ma sembra aver avuto un ruolo secondario, o poco apprezzabile, fino ad oggi. da un punto di vista concettuale un innalzamento progressivo del livello medio del mare determinerebbe una tendenza al sovralluvionamento in corrispondenza degli alvei (a causa dell'innalzamento del livello di base dei corsi d'acqua) e parallelamente un arretramento della linea di costa. l'arretramento della linea di riva che si verrebbe a determinare dovrebbe essere generalizzato e non differenziale a seconda che si considerino le zone di foce o le zone inter-foce. anche tale meccanismo non sembra concordare concettualmente con le informazioni raccolte. le variazioni temporali delle caratteristiche del moto ondoso hanno probabilmente giocato un ruolo importante nell'evoluzione della linea di riva in oggetto. tale fattore esula dagli strumenti e dagli obiettivi del presente lavoro ed andrà tenuto in debita considerazione in occasione di eventuali passi successivi. tuttavia, anche in assenza di dati sulle variazioni storiche delle caratteristiche del moto ondoso, pare distinguibile l'effetto delle variazioni di apporto solido fluviale, soggiacente al trend evolutivo che può essere inferenziato dalla serie storica delle linee di riva. un effetto diretto ed evidente hanno avuto, e tuttora hanno, le difese costiere e la realizzazione dei moli del porto di pescara. i grafici che riportano le variazioni nel tempo delle linee di riva mostrano sensibili avanzamenti nei tratti interessati dalle difese costiere in particolar modo nel periodo immediatamente successivo alla loro realizzazione, al contrario marcati arretramenti vengono da queste indotti nei tratti adiacenti non protetti. come verrà trattato più in dettaglio, la costruzione di barriere emerse distaccate lungo la costa ha caratterizzato a partire dalla prima metà degli anni '70 il tratto compreso tra la foce del fiume saline ed il porto canale di pescara: qui i tratti protetti sono stati ampliati progressivamente fino ad interessare l'intera unità fisiografica. 5. evoluzione della linea di costa 5.1 ricostruzione della serie storica delle linee di costa per la ricostruzione della serie cronologica delle successive posizioni della linea di riva si è reso necessario il reperimento di carte storiche e riprese aeree con un certo grado di attendibilità e di dettaglio tale da permetterne una corretta georeferenziazione. sulla base di tali caratteristiche sono stati selezionati alcuni documenti cartografici realizzati nel corso dell'800 che coprono l'area in questione o che la rappresentano in parte (“pianta del litorale dell'adriatico, con l'indicazione della strada nuova che vi si progetta”, 1819, archivio di stato di napoli; “mappa topografica di pescara, castellammare adriatico, montesilvano e francavilla, 1838”, archivio di stato di pescara; rilevi dello stato borbonico relativi al 1859; rilievi dell'igmi relativi agli anni 1872-76). ulteriori informazioni riguardanti linee di costa storiche relative al tratto compreso tra il saline ed il pescara sono state tratte da fo d e r à (1954), in particolare per quanto riguarda le linee di riva del 1894 e del 1926-29. per la ricostruzione delle linee di costa più recenti sono state prese in considerazione le riprese aeree della raf (anni 1943-44), dell'igmi (anni 1955, 1976, 1995) e della compagnia generale riprese aeree (cgr, progetto it2000), accessibile attraverso il sistema del portale cartografico nazionale (www.atlanteitaliano.it) gestito dal ministero dell' ambiente del territorio e del mare. ulteriori informazioni 197 fig. 4. ubicazione dell'asse di riferimento e dei transetti utilizzati per la costruzione dei grafici di figura 5 e dei diversi settori relativi ai grafici di figura 6. baseline, transects and different sectors used for the measurements plotted in figures 5 and 6. riduzione del trasporto solido fluviale ... sono state tratte dalle ortofotocarte relative al 1987-88 realizzate dalla regione abruzzo nonché dalle tavolette a scala 1:25000 dell'igmi (aggiornata per l'area in questione nel 1982). la linea di riva più recente, riferita al 2004, è stata ottenuta mediante internet attraverso l'applicativo google earth®. per il processo di georeferenziazione è stato utilizzato un software di trasformazione in grado di rototraslare e deformare le immagini acquisite secondo funzioni polinomiali, in modo da ottenere la migliore correlazione tra punti presenti nell'immagine e omologhi punti aventi coordinate note (gcps), individuati su carte ortorettificate o direttamente sul terreno. mediante tale procedimento è possibile determinare anche l'errore connesso con l'operazione (root mean square error), che definisce il grado di imprecisione in metri nell'immagine trasformata. al fine di limitare l'imprecisione, oltre alla scelta del maggior numero possibile di gcps distribuiti in modo per quanto possibile omogeneo, sono state prese in considerazione percentuali ridotte dei fotogrammi o delle carte originarie. trattandosi inoltre di aree pianeggianti non si è reso necessario tenere in considerazione l'effetto di distorsione indotto dalla topografia. l'uso delle mappe storiche risalenti al xix secolo implica necessariamente l'introduzione di un elevato grado di incertezza a causa dell'imprecisione delle mappe stesse e della maggiore difficoltà nell'individuazione di punti di riferimento per la georeferenziazione. questi sono in numero progressivamente minore in funzione dell'età delle mappe, motivo per cui il grado di attendibilità delle stesse è stato attentamente e criticamente valutato verificando la coerenza tra quelle relative allo stesso periodo, ma anche la corrispondenza delle linee di riva ricostruite con il trend evolutivo generale. con la successiva digitalizzazione delle diverse linee di costa è stata ricavata la serie storica, utilizzata per il computo del tasso di variazione della posizione della linea di riva. inoltre ne è stato ricavato il tasso di variazione in termini di superficie emersa, al fine di ottenere una stima indiretta dell'andamento del bilancio sedimentario. 5.2 tendenza evolutiva la differente tendenza evolutiva dei tratti posti in prossimità delle foci del vomano e del saline rispetto ai tratti interdeltizi è messa in evidenza in figura 5, in cui vengono riportati i grafici delle diverse posizioni della linea di riva in corrispondenza di transetti rappresentativi posti lungo l'asse di riferimento longitudinale (riportato in figura 4). i grafici di figura 6 riportano invece la variazione nel tempo della superficie compresa tra la linea di costa e l'asse di riferimento, per i diversi settori presi in considerazione. in riferimento a tali figure si può notare come la posizione della linea di costa abbia subito un generale repentino avanzamento nel corso del xix secolo, caratterizzato da un bilancio sedimentario del litorale positivo. equiparando il bilancio sedimentario all'andamento delle variazioni della superficie costiera (fig.6), esso sembra subire una flessione agli inizi del '900, assumendo un valore intorno allo zero nel periodo compreso all'incirca tra il 1920 ed il 1940. successivamente assume un valore negativo e piuttosto costante nel tempo fino ai giorni nostri. e' evidente il marcato trend erosivo nel corso del xx secolo, a partire dal 1943, in corrispondenza del transetto 'a', posto a poche centinaia di metri dalla foce del vomano e del transetto 'c', in corrispondenza dell'apparato di foce del saline. il tasso di arretramento presso la foce del vomano subisce un'inversione di tendenza nelle ultime 3 osservazioni, probabilmente a causa di interventi di ripascimento e di protezione realizzati nella prima metà degli anni '80. la zona di foce del saline ha fatto registrare i tassi di arretramento medi più elevati (circa -2,4 m/anno), con i valori maggiori tra il '43 ed il '55 (circa -5,8 m/anno). ben diverso è il comportamento in corrispondenza del transetto 'b', posto in zona interdeltizia tra la torre di cerrano e l'abitato di silvi: qui si ha un avanzamento che interessa tutto il periodo di osservazione, con un valore che si aggira intorno a 0.9 m/anno. la situazione nella zona centrale dell' unità fisiografica sud è ancora diversa: qui la realizzazione delle barriere emerse a partire dalla metà degli anni '70 ha alterato la tendenza naturale facendo registrare considerevoli avanzamenti a tergo delle scogliere. la situazione presso il transetto 'd' sembra andare verso una stabilizzazione, e tendere localmente ad una più recente fase erosiva nelle ultime 3 osservazioni, probabilmente anche a causa del potenziamento delle difese parallele in un tratto adiacente, in corrispondenza dell'abitato di montesilvano. in riferimento alla figura 6a, che riporta le variazioni areali per le due unità fisiografiche (vomano-saline saline-pescara), è evidente il diverso comportamento del tratto sud, completamente protetto, dalla porzione nord quasi priva di strutture protettive. a partire dal 1943 circa il t r e n d assume un andamento piuttosto regolare e può essere ricavato interpolando linearmente i grafici di fig.6: il tasso di variazione medio della superficie di costa corrisponde alla derivata rispetto al tempo della curva interpolante. in particolare dal 1943, la variazione nel tempo della superficie costiera tra il vomano ed il saline è di circa -5429 m2/anno, mentre risulta pari a circa 6077 m2/anno per la zona compresa tra il saline ed il porto di pescara. un'ulteriore differenziazione dell'unità fisiografica nord in 2 sottosettori (fig. 6b) mette in evidenza gli effetti degli interventi di ripascimento effettuati negli anni '80 nei pressi della foce del vomano. l'aumento di superficie registrato dall'ultima osservazione (2004) è infine da attribuirsi ai recenti interventi di ripascimento e di realizzazione di barriere sommerse, effettuati dalla regione abruzzo lungo un tratto posto a nord della foce del saline. il prodotto delle variazioni di superficie, avvenute in un determinato intervallo temporale, per lo spessore del profilo di spiaggia attivo (pari alla somma della “profondità di chiusura” e dell'altezza di spiaggia emersa interessata dal moto ondoso) può fornire una stima approssimativa dei volumi in gioco. lo spessore del profilo di spiaggia attivo è per definizione pari alla somma della “profondità di chiusura” e dell'altezza di spiaggia emersa interessata dal moto ondoso. la profondità di chiusura è, rispetto al livello medio del mare, quella oltre la quale può considerarsi trascurabile il movimento sedimentario dovuto all'azione del moto ondoso. in fig. 11a viene riportato lo 198 c. manzo 199 fig. 5 situazione riscontrata presso i transetti di misura rappresentativi indicati in fig. 4.: a) vista della spiaggia in corrispondenza del transetto 'a' con relativo andamento nel tempo della posizione della linea di riva; in foto sono evidenti i diversi riduzione del trasporto solido fluviale ... ordini di “crest berms” a granulometria ciottolosa; b) panoramica della spiaggia nei pressi del transetto 'b' e relativo grafico; c) tratto di spiaggia posto in corrispondenza del transetto 'c', nei pressi della foce del saline; è distinguibile il gradino erosivo con messa a nudo di limi di retro-spiaggia, da mettere in relazione con la marcata tendenza all'arretramento evidenziata nel sottostante grafico; d) vista di un tratto di spiaggia posta nella zona sud di montesilvano e grafico relativo al transetto 'd'. images and graphics of the main significant beach stretches (see fig. 4): a) photograph taken by the transect 'a' with related graphic showing temporal variation of the coastline; see different steep pebbled berm orders; b) wide sandy beach nearby the transect 'b' and related graphic; c) pebble beach placed by the transect 'c', few hundred meters north to saline outlet; the outcrop of cohesive backshore silts is a clear effect of beach erosion, showed in the related graphic; d) view of the beach placed nearby the south end of montesilvano town and graphic showing coastline variations at transect 'd'. schema esemplificativo di un volume elementare di spiaggia in condizioni di equilibrio del profilo trasversale, con indicazione del significato dei diversi termini del bilancio. sulla base di informazioni bibliografiche (aquater, regione abruzzo, 1982, 1985; provincia di teramo, assessorato ai lavori pubblici, 1998) è stato considerato uno spessore del profilo attivo pari a 7 m che porta, per l'unità fisiografica nord, ad un bilancio sedimentario medio pari a circa -38000 m3/ a n n o per il periodo 1943 ÷ 2000. un'analoga stima relativa all'unità sud perde invece di significato a causa delle forti alterazioni indotte dalla realizzazione delle barriere sulla morfologia della spiaggia sommersa. tale stima fornisce ovviamente indicazioni approssimative che possono essere utilizzate perlopiù ai fini della formulazione di un modello preliminare: si basa infatti sull'assunto che il profilo di equilibrio della spiaggia rimanga mediamente invariato, dipendendo principalmente dall'energia media del moto ondoso e dalle proprietà fisiche dei sedimenti, che possono ritenersi mediamente costanti a determinate scale temporali. tale esemplificazione costituisce il principale limite insito nella ricostruzione del bilancio sedimentario a partire da informazioni di tipo essenzialmente planimetrico. 5.3 definizione del modello evolutivo le informazioni raccolte suggeriscono la formulazione di un modello concettuale che mette in relazione l'apporto solido fluviale alle variazioni della linea di costa. la situazione emersa evidenzia come il corso del xix secolo sia stato contraddistinto da un elevato bilancio sedimentario costiero tanto che ampie aree, su cui sorgono gli abitati di pescara, montesilvano e silvi marina, sono state urbanizzate su terreni formatisi a partire dalla seconda metà dell'800. il bilancio diviene poi negativo nel corso del xx secolo, con valore assoluto però inferiore a quello del secolo precedente. gli apparati di foce, avendo una conformazione convessa, rappresentano zone di divergenza della deriva sedimentaria lungo-costa. essi hanno subito le maggiori modificazioni, sia in avanzamento nel corso dell'800, sia in occasione dell'inversione di tendenza avutasi a partire dai primi decenni del '900 (figg. 7 e 9). le modificazioni dei tratti interdeltizi, che al contrario costituiscono le principali zone 200 fig. 7 principali modificazioni del delta del vomano avvenute negli ultimi due secoli, riportate su una ripresa aerea del 1998. main modifications of vomano river delta in the last two centuries, plotted on a 1998 aerial image. c. manzo fig. 6 variazioni della superficie costiera delimitata dall'asse di riferimento secondo una suddivisione in diversi settori: a) variazioni di superficie costiera nelle due principali unità fisiografiche considerate; b) variazioni di superficie presso due sotto-settori compresi nell'unità fisiografica nord, tra il fiume vomano e la torre di cerrano e tra la torre di cerrano ed il fiume saline. coastal area variations vs. time of principal coastal plain sectors, delimited by the baseline: a) area variations in the two physiographic units considered; b) area variations in two sub-sectors of the northern physiographic unit, the first placed between vomano and torre di cerrano and the latter between torre di cerrano and saline river. 201 fig. 8 principali variazioni della linea di costa nel tratto posto in corrispondenza della torre di cerrano e dell'abitato di silvi marina, riportate su foto aerea del 1998. si può notare la relativa stabilità della linea di riva mentre sono distinguibili 3 ordini di barre sabbiose nella spiaggia sommersa. main modifications of the coast stretch nearby the torre di cerrano and the village of silvi marina, plotted on a 1998 aerial image. the image shows a quite coastline stability in the last two centuries and three orders of submerged sand bars. fig. 9 principali modificazioni delle zone di foce del saline e del piomba avvenute negli ultimi due secoli, riportate su ripresa aerea del 1998. main modifications of saline and piomba river mouths in the last two centuries. riduzione del trasporto solido fluviale ... di convergenza del trasporto sedimentario, sono invece “smorzate” e ritardate rispetto alle dinamiche dei delta fluviali (figg. 8, 10). in riferimento alle figure 7 e 9, è possibile notare come i tratti terminali del vomano e del saline presentassero un andamento tipicamente b r a i d e d con alvei attivi molto ampi e considerevoli modificazioni del tracciato fino agli anni '40-'50. attualmente gli stessi alvei appaiono più stretti, di tipo monocursale e quasi del tutto privi di barre attive. risulta invece più stabile nel tempo il tracciato di foce del fiume pescara. il comportamento evidenziato può essere ricondotto ad una continua fase di riequilibrio del profilo planimetrico della linea di costa in funzione delle variazioni del budget sedimentario. questo può essere descritto in maniera semplificata dall'equazione di diffusività, combinata ai termini di ingresso ed uscita dal sistema: ∂y/∂t=ε∂2y/∂x2 + i l (1) ossia, la variazione della posizione della linea di riva nel tempo è pari alla derivata seconda rispetto all'asse longitudinale moltiplicata per il fattore di diffusività (ε), e sommata ai termini di ingresso (i), rappresentati dall'apporto solido, e di uscita (l), dovuti alle perdite verso il mare. il fattore di diffusività dipende dalle caratteristiche del moto ondoso, dal profilo trasversale della spiaggia e dalle proprietà fisiche del sedimento, ed è quindi un parametro di difficile quantificazione sperimentale. generalmente è possibile definirlo mediante analisi inversa. in particolare: k h2 b cgb ρ 1 1 ε = __________ ( ______) (______ ) (________ ) (2) 8 ρs ρ 1 n db + dc dove hb è l'alezza dell'onda al frangimento, cgb la velocità di gruppo del moto ondoso, ρ e ρs sono rispettivamente la densità dell'acqua e del sedimento, db e dc sono rispettivamente l'altezza di spiaggia emersa interessata dal moto ondoso e la profondità rispetto al livello medio del mare interessata da movimento sedimentario significativo. l'equazione della diffusività può essere ottenuta dalla combinazione dell'equazione di continuità del flusso sedimentario con una relazione in grado di descrivere il trasporto sedimentario lungo-costa in funzione della componente longitudinale del flusso energetico del moto ondoso, quale ad esempio: q=q0*k*tan(α), generalmente valida per 0< tan(α)<1.23 (3) in tale relazione 'k' è una costante ed 'α' rappresenta l'angolo formato tra le creste d'onda e la linea di riva (u.s. army corps of engineers®, 2002). si è scelto di utilizzare una soluzione alle differenze finite dell'equazione (1), per simulare l'evoluzione della linea di costa nell'unità fisiografica nord, non interessata da interventi massicci di difesa che possano averne alterato la naturale tendenza evolutiva. come ulteriore esemplificazione si è scelto di far partire la simulazione dal 1943, assegnando come situazione di partenza la rispettiva linea di riva, dal momento che il trend del bilancio di sedimento risulta pressoché costante a partire da questa data. e' stata quindi operata una discretizzazione longitudinale di 100 m e temporale di 4 mesi. il fattore 'ε' è stato ricavato in seguito ad un'operazione di taratura effettuata sulla base delle linee di costa osservate. i risultati della simulazione vengono mostrati in fig 12b e confrontati con le diverse linee di costa ricostruite (fig 12a). considerato che ai bordi del modello sono poste le foci dei fiumi vomano (al confine nord) e saline202 fig. 11 schema di un volume elementare di spiaggia in condizioni di equilibrio del profilo trasversale (a). definizione dell'angolo di incidenza del moto ondoso αb (b) scheme of elemental volume on equilibrium beach profile (a). definition of local breaker angle ab (b). c. manzo fig. 10 principali variazioni della linea di costa in un tratto di costa posto in corrispondenza della città di pescara, riportate su foto aerea del 1998. e' visibile la notevole ampiezza della spiaggia, dovuta all'avanzamento registrato in seguito alla realizzazione delle barriere emerse. main modifications in the coast stretch of pescara, plotted on a 1998 aerial image. the wide is due to the advancement which took place after the realization of the emerged barriers. piomba (confine sud) i valori di trasporto solido posti come condizioni al contorno sono stati inizialmente impostati pari alle indicazioni bibliografiche riportate in tab.2. tali valori sono stati modulati, in seguito ad un'operazione di taratura, al fine di ottenere un'evoluzione temporale della linea di costa confrontabile con quella osservata, risultando pari a 53000 m3 per il confine nord e 44000 m3/anno per il confine a sud. di fatto, in base alle informazioni rguardanti la deriva sedimentaria longitudinale netta (aquater, regione abruzzo, 1982; aquater, regione abruzzo, 1985; noli et al., 1998) ricavata in funzione di uno studio del clima di moto ondoso, tali condizioni di flusso sedimentario in ingresso ai bordi del modello sono attribuibili in massima parte al trasporto solido fluviale. le perdite verso il largo sono state inizialmente poste, in valore assoluto, pari a 10 m3 annui per metro lineare, sempre sulla base delle indicazioni bibliografiche di cui sopra. in seguito al processo di taratura del modello i valori ottimali medi sono risultati molto simili ai valori assunti inizialmente, sebbene sia stato necessario modularli lungo l'asse longitudinale. in particolare la convergenza ottimale con la situazione reale è stata ottenuta utilizzando valori massimi in corrispondenza delle zone di foce (pari a circa 11 m3 a n n u i per metro lineare), e valori minimi in corrispondenza del promontorio della torre di cerrano (circa 4,2 m3 annui per metro lineare). tale assunzione trova giustificazione nella conformazione batimetrica, con pendenze maggiori nelle zone di foce rispetto alla parte centrale dell'unità fisiografica. qui la presenza di condizioni particolarmente dissipative nei confronti del moto ondoso potrebbero inoltre essere determinate dalla presenza di fondali poco profondi la cui morfologia pare influenzata dalla zona di accumulo di antichi movimenti gravitativi (buccolini et al., 1994). secondo alcuni autori tali movimenti, di tipo rotazionale multiplo, avrebbero interessato i versanti collinari che degradano verso il mare: il promontorio della torre di cerrano, che costituisce una delle poche irregolarità di tipo morfologico a perturbare l'andamento della linea di riva, ne sarebbe una delle testimonianze più evidenti1. in generale comunque le linee di riva osservate appaiono più irregolari rispetto a quelle simulate, come effetto delle semplificazioni del modello, che non considera la variabilità spaziale e/o temporale dei parametri di ingresso (quali il trasporto solido fluviale, le perdite verso il mare, la diffusività e la direzione di provenienza del moto ondoso) né l'effetto delle difese costiere. inoltre è da tenere in considerazione che la spiag203 1 in corrispondenza del tratto di costa della torre di cerrano si possono osservare, in posizione sub-affiorante, blocchi isolati di conglomerati appartenenti alla successione siciliana, depositatasi al top della formazione delle argille arigio-azzurre, che rappresentano i resti di queste frane. vi sono inoltre notizie sulla presenza di un antico porto in questa zona, attivo fino al xv secolo (buccolini et alii, 1994; noli et al., 1998), di cui vi sarebbero testimonianze nella presenza di blocchi sommersi presenti fino a circa 700-900 m dalla riva. anche tali blocchi però, piuttosto che riconducibili a manufatti in calcestruzzo, potrebbero derivare dalla frammentazione del corpo conglomeratico siciliano. fig. 12 linee di riva del tratto compreso tra il vomano ed il saline, ricostruite mediante l'indagine storica, riportate con discretizzazione longitudinale di passo pari a 100 m (a). linee di riva simulate mediante il modello per il medesimo tratto (b). observed coastlines of the stretch between vomano and sali90ne river mouths, plotted with a 100 m discretization step (a). simulated coastlines of the same coast stretch (b). riduzione del trasporto solido fluviale ... gia è un corpo sedimentario che può modificare la sua forma ma non necessariamente il suo volume, e la linea di riva risente ovviamente di tali modifiche. tuttavia la metodologia utilizzata può risultare un buon compromesso tra i costi e i risultati: eventuali metodologie più raffinate necessitano infatti della definizione di svariati parametri naturali che hanno un'estrema variabilità spaziale e temporale di difficile quantificazione (caratteristiche batimetriche, sedimentologiche, meteo-marine, agli apporti solidi fluviali, agli effetti delle opere antropiche) ed implicano l'utilizzo di modelli interpretativi complessi che comportano problematiche di gestione del processo di calcolo (stabilità, convergenza) ed i cui risultati devono essere valutati attentamente. nonostante il modello r isult i quindi estremamente semplificato, sembra comunque in grado di riprodurre, a grandi linee, la dinamica del tratto di litorale in oggetto: la progressiva rettificazione della linea di costa dovuta allo smantellamento degli apparati di foce (ai bordi del grafico) è accompagnata dalla modesta progradazione del tratto posto al centro dell'unità fisiografica. mantenendo un bilancio sedimentario costante, tuttavia, i tratti in erosione tendono a coinvolgere progressivamente anche le zone più distanziate dalle foci, come la zona sud di silvi e la spiaggia posta in corrispondenza dell'abitato di pineto. la prominenza degli apparati di foce aumenta al crescere del bilancio sedimentario del litorale, per cui la morfologia del delta del saline di fine '800 è verosimilmente riconducibile ad un elevato budget sedimentario avutosi in questo periodo, mentre una probabile diminuzione dello stesso agli inizi del '900, anche non configurandosi ancora come una situazione di deficit, può averne determinato la fase di arretramento ancor prima dell'effetto dovuto alla forte antropizzazione dei bacini. tale considerazione è teoricamente valida a condizione che l'andamento nel tempo della diffusività (ε) sia di tipo stazionario, cosa che dovrà essere verificata attraverso lo studio di eventuali cambiamenti del clima di moto ondoso occorsi nel periodo investigato. 6. considerazioni conclusive tramite la ricostruzione della serie storica delle variazioni della linea di riva del tratto costiero in questione è possibile rilevare una differenziazione in termini di trend evolutivo di diversi settori: quelli deltizi, a forte dinamicità sia in avanzamento (durante le fasi di bilancio sedimentario positivo) sia in arretramento (nelle fasi di deficit); quelli interdeltizi, a minor tasso di variazione in termini assoluti, la cui risposta ai cambiamenti di apporto solido è ritardata rispetto alle zone di foce. in base alla ricostruzione delle linee di costa storiche e alle simulazioni effettuate con il modello è possibile constatare come una variazione del bilancio sedimentario inneschi un fenomeno di riequilibrio del profilo planimetrico della linea di costa, che interessa dapprima le zone di delta per poi propagarsi progressivamente alle zone interdeltizie. in conseguenza della diminuzione dell'apporto solido a mare avutasi a partire dai primi decenni del secolo passato, il bilancio sedimentario è passato da un valore decisamente positivo ad un valore negativo. la fase di arretramento che ne è seguita non ha interessato in maniera uniforme il litorale ma soprattutto le zone di foce, mentre un ampio tratto posto in corrispondenza dell'abitato di silvi marina e della torre di cerrano ha continuato ad avanzare grazie alle condizioni di convergenza del trasporto sedimentario longitudinale. sotto la condizione ipotetica di un bilancio sedimentario costante, l'arretramento potrà interessare anche quest'ultimo tratto, a partire dal momento in cui sarà completata la fase di riequilibrio dinamico con il raggiungimento di una conformazione morfo-planimetrica stabile. tale fenomeno sarebbe però attenuato dalle condizioni dissipative determinate dall'azione di ridosso esercitata dai fondali antistanti, che in questo tratto di litorale risultano piuttosto superficiali e poco acclivi. le dinamiche dei litorali paiono quindi in stretta connessione con le quelle fluviali, specialmente nei loro tratti medio-terminali: parallelamente all'arretramento della linea di riva nelle zone deltizie si è innescato un fenomeno di approfondimento degli alvei con una conseguente modificazione del profilo longitudinale dei corsi d'acqua. lo schema concettuale semplificato del fenomeno è illustrato in fig.12. sebbene i risultati presentati abbiano soprattutto un valore qualitativo, si ritiene che il modello concettuale derivante sia generalizzabile agli ambiti in cui la dinamica del litorale risulta in stretta connessione con quella fluviale. la metodologia utilizzata, grazie alla progressiva diffusione di immagini aeree e satellitari, promette di fornire buoni risultati a basso costo. foto aeree: immagini terraitalytm © compagnia generale ripreseaeree s.p.a. www.terraitaly.it 204 fig. 13 schema semplificato degli effetti del deficit sedimentario sul sistema fluvio-costiero, avvenuti nell'ultimo secolo (disegno non in scala): modificazioni del profilo planimetrico della linea di riva (a); modificazione del profilo longitudinale dei corsi d'acqua nei tratti medio-terminali (b). simplified scheme of sedimentary deficit effects on the river-coastal system, occurred in the last century (without scale drawing): coastline modifications a); longitudinal profile modifications on middle-lower reaches of stream branches (b). c. manzo riferimenti bibliografici adamoli l. (1991) variazioni della linea di riva e cause dell'erosione del litorale abruzzese dal tronto al p e s c a r a . atti del 3o geological day “la costa abruzzese: dinamica del litorale, processi erosivi, degrado ambientale e possibili strategie di intervento”. ordine nazionale dei geologi, ccr abruzzo. 45-61. pescara. ad a m o l i l. (1994) interventi antropici ed ambiente geologico in abruzzo: alcuni esempi di impatto sul sistema fluviale-costiero e sul sistema acquifero s o t t e r r a n e o . in “viii congresso di scienze della terra e trasformazioni antropiche, un rapporto in evoluzione”. consiglio nazionale dei geologi. 227-231. al b e r t i a., li p p a r i n i t., st a m p a n o n i g., mi n i s t e r o d e l l' in d u s t r i a d e l co m m e r c i o e d e l l' ar t i g i a n a t o, di r e z i o n e ge n e r a l e d e l l e mi n i e r e, se r v i z i o ge o l o g i c o d' it a l i a (1967) note illustrative della carta geologica d'italia foglio 141 pescara. 47 pp. poligrafica & cartevalori, ercolano (napoli). aquater, regione abruzzo (1982) studio generale per la difesa della costa, prima fase. 3 valutazione dell'apporto solido a mare; 4 aspetti meteomarini e determinazione e del trasporto litoraneo. s. lorenzo in campo (progetto depositato presso l'assessorato ai ll.pp. della regione abruzzo, l'aquila).. aquater, regione abruzzo (1985) studio generale per la difesa della costa, seconda fase. analisi del regime del trasporto litoraneo e bilancio dei sedimenti. s. lorenzo in campo (progetto depositato presso l'assessorato ai ll.pp. della regione abruzzo, l'aquila). bu c c o l i n i m., cr e s c e n t i u, sc i a r r a n. (1994) interazione tra dinamica dei versanti ed ambienti costruiti: alcuni esempi in abruzzo. dipartimento di scienze, storia dell'architettura e restauro, università g.d'annunzio, pescara. buccolini m., tiberio s. (2001) evoluzione recente ed in atto nell'alveo del fiume tavo-saline (abruzzo centrale. mem. soc. geol. it., 56, 243-248. carobene (2004) uplifted coastlines and marine terraces. 174-177. geology of italy, florence2004. da l ci n r., si m e o n i u. (1987) l'analisi multivariata applicata alla caratterizzazione ambientale dei litorali nord-abbruzzesi (medio adriatico). mem. soc. geol. it. 37, 379-389. dal cin r., simeoni u. (1987) analisi ambientale quantitativa dei litorali marchigiani fra gabicce e ancona. livello del rischio naturale e del degrado, distribuzione dei sedimenti e loro possibile impiego per ripascimenti artificiali. boll. soc. geol. it. 106, 377-423. dal cin r. (1991) i litorali tra san benedetto ed ortona (medio adriatico): sedimenti, degrado ambientale, zonazione costiera, possibil i s trategie di i n t e r v e n t o. atti del 3o geological day “la costa abruzzese: dinamica del litorale, processi erosivi, degrado ambientale e possibili strategie di intervento. ordine nazionale dei geologi , ccr abruzzo. 11-44. pescara. fa n t u c c i r., ma r g o t t i n i c. (1996) c l i m a t o l o g i c a l trends on some of the longest rainfall data sets in italy. the integrated geological risk assessment. environmental and climate program, european commission. fo d e r à o. (1954) le variazioni della linea di spiaggia della costa ed il demanio pubblico marittimo nella provincia di pescara. estratto dalla rivista del catasto e dei servizi tecnici erariali, 25 pp. ministero ll.pp. servizio idrografico. annali idrologici (pescara). parte i e ii. 1919 1994. no l i a., to g n a a., co n t i n i p., sa l t a r i d., pr o v i n c i a d i teramo (1998) litorale tramano compreso tra le foci del vomano e del piomba (studio di dinamica l i t o r a n e a ). 63pp. documento depositato presso l'assessorato a i ll.pp. del la provincia di teramo. parea g.c. (1978) trasporto dei sedimenti ed erosione costiera lungo li litorale tra li tronto ed il fortore (adriatico centrale). mem. soc. geol. it. 19, 361367. simeoni u. (1989) rapporti tra barre e caratteri idrodinamico-geomorfologici nei litorali nord-abruzzesi (medio adriatico). boll. soc. geol.it. 108, 161-173. tei, regione abruzzo (1986) piano di risanamento dei bacini idrografici dei fiumi vomano, aternopescara e sangro. rapporto conclusivo, 29-42. u.s. army corps of engineers®, rosati j. d., walton t., bo d g e k. (2002) coastal engineering manual, parte iii, cap.2: longshore sediment transport, 119 pp. 205 ms. ricevuto il 18 marzo 2008 testo definitivo ricevuto il 28 maggio 2008 ms. received: march 18, 2008 final text received: may 28, 2008 riduzione del trasporto solido fluviale ... imp.martino& aspetti morfotettonici dell’evoluzione geomorfologica della valle del melandro (appennino campano-lucano) claudio martino 1 & marcello schiattarella 1 1 dipartimento di scienze geologiche, università degli studi della basilicata, potenza riassunto: c. martino & m. schiattarella, aspetti morfotettonici dell’evoluzione geomorfologica della valle del melandro (appennino campano-lucano). (it issn 0394-3356, 2006). la valle del melandro è una depressione tettonica che si sviluppa in direzione no-se lungo la zona assiale della catena sud-appenninica. è colmata da sedimenti quaternari che giacciono su due grandi unità tettoniche sovrapposte: l’unità dei monti della maddalena, costituita prevalentemente da carbonati meso-cenozoici di mare basso, a tetto e le unità lagonegresi, formate da successioni pelagiche mesozoico-terziarie, a letto. tali caratteri rendono l’area particolarmente adatta alla stima dei tassi di sollevamento: sono infatti presenti successioni sufficientemente resistenti all’erosione da conservare diversi elementi morfotettonici relativamente antichi, con particolare riferimento alle superfici erosionali sospese, sufficientemente vincolabili cronologicamente grazie alla presenza di successioni plioceniche e pleistoceniche. i tassi di sollevamento sono stati calcolati usando la differenza di quota tra superfici erosionali ed il livello di base assoluto (livello del mare) e locale (talweg attuale). sono stati inoltre stimati i tassi di sollevamento per intervalli temporali compresi tra due fasi di erosione consecutive (sollevamento “partizionato”), considerando la differenza di quota tra un dato ordine di superfici e quello immediatamente più giovane. nella valle e sui rilievi contigui sono stati distinti quattro ordini di superfici erosionali con peculiari caratteristiche morfologiche, che differiscono tra la dorsale carbonatica in sinistra orografica ed il fianco opposto in terreni lagonegresi. l’ordine più antico (s1) corrisponde alla paleosuperficie auctt. di età altopliocenica, poichè rasa depositi marini del pliocene inferiore-medio affioranti sui monti della maddalena. morfologicamente incastrate nella superficie sommitale appaiono le superfici s2, s3 ed s4. le superfici s3 rasano il riempimento continentale del bacino della valle del melandro del pleistocene inferiore: ciò permette di attribuire tale ordine alla parte alta del pleistocene inferiore, al passaggio con il pleistocene medio. le superfici s2, interposte tra s1 e s3, sono conseguentemente attribuibili al pleistocene inferiore. infine, le superfici s4 sono databili al pleistocene superiore per correlazione morfostratigrafica su scala regionale. le superfici s1, modellate nel pliocene superiore, sono state tettonicamente sbloccate durante l’inizio del pleistocene inferiore, mentre quelle s2, che si sono formate prima della deposizione del riempimento continentale del bacino della valle del melandro, hanno iniziato a sollevarsi durante l’episodio tettonico regionale di età emiliana. i glacis erosionali s3, modellati dopo l’aggradazione del bacino ad opera dei depositi alluvionali, sono stati disattivati e sollevati al debutto del pleistocene medio, mentre i terrazzi erosionali (s4), morfologicamente incastrati nei precedenti, hanno subito un sollevamento durante il pleistocene superiore. i due fianchi del bacino presentano modalità di sollevamento differenti. nel corso del pleistocene inferiore, il versante in destra orografica si solleva più velocemente rispetto a quello opposto, mentre a partire dal pleistocene medio avviene il contrario. in generale, i tassi di sollevamento calcolati per l’intero bacino della valle del melandro hanno messo in evidenza un decremento dei valori tra il pleistocene inferiore e quello medio, considerando il sollevamento locale e “partizionato”, a differenza dei dati relativi al sollevamento regionale che descrivono un trend crescente a partire dall’inizio del pleistocene. la comparazione tra le quote dei relitti di superfici erosionali con il profilo longitudinale del fiume sele, a partire dal torrente pergola (affluente del fiume melandro, che fa appunto parte del sistema idrografico a recapito tirrenico del sele), ha permesso di ipotizzare una formazione in ambiente genetico fluviale delle superfici s3 ed s4 ben al di sopra del livello del mare. queste presentano, infatti, un andamento conforme a quello del profilo longitudinale del fiume sele. le superfici s1 ed s2 hanno, invece, un andamento molto regolare e prossimo alla orizzontalità, come possibile conseguenza di un modellamento in corrispondenza del livello del mare, geneticamente legato all’azione dell’abrasione marina. queste considerazioni permettono di operare una correzione alla stima dei tassi di sollevamento regionale per le superfici s3, sulla base della differenza di quota che intercorre tra tali superfici ed il paleo-livello di base relativo alla parte alta del pleistocene inferiore, impostato sui conglomerati di eboli. tale correzione modifica l’andamento del tasso di sollevamento regionale e lo rende congruente con i tassi di uplift locale e “partizionato”. abstract: c. martino & m. schiattarella, morphotectonics and quaternary geomorphological evolution of the melandro valley, southern apennines, italy. (it issn 0394-3356, 2006). the target of this study is to furnish new data on the morphotectonic setting of a key-area of the southern italian apennines, the valley of melandro river, by means of both geomorphological and structural analyses. further, a fruitful attempt of morphostratigraphic correlation of several orders of sub-horizontal land surfaces and flat summit landscapes with other similar geomorphic features on a regional scale has been done. the age attribution of such features to sufficiently constrained pliocene and pleistocene time intervals allowed the calculation of the regional and local uplift rates and the reconstruction of the morphotectonic history of the study area. the melandro river basin is a tectonic depression located in the axial zone of the south-apennines chain, a fold-and-thrust belt strongly uplifted and fragmented by neotectonics and therefore characterized by many quaternary longitudinal and transversal morphostructural depressions. the uplift rates have been estimated using geomorphological, stratigraphical and structural data. geomorphic data consist essentially of elevation values, ages and arrangement of erosional gently dipping land surfaces and other morphotectonic indicators. the morphostructural evolution of the melandro river basin is characterized by stages of uplift alternated with slack periods in which the erosional surfaces developed. in particular, four generations of land surfaces have been detected on the basis of both field survey and map analysis. the age of these surfaces have been defined on the basis of morphostratigraphic relationships with the pliocene and quaternary deposits. specifically, the oldest surface was sculptured also in the marine pliocene deposits whereas the intermediate surface cuts the continental lower pleistocene sediments filling the main depression. the youngest surface is late pleistocene in age, as verified for similar terraces in adjacent areas. the uplift rates have been calculated on the basis of the difference in height between the absolute (sea level) or local (present-day talweg) erosion base levels and the several generations of land surfaces. further, in this study we also calculated the stage (or partitioned) uplift on the basis of the difference in height between a given order of land surfaces and that immediately younger, aiming to consider the behaviour trend in specific time intervals. the trend of stage uplift is characterized by two increments: the first during the upper part of the early pleistocene and the second during the late pleistocene. new data permitted us to restore the palaeomorphology of the different land surfaces and, by comparing them with present-day longitudinal stream profiles, to formulate suitable hypotheses on the genetic environments of these ancient erosional flat landscapes. in particular, the older surfaces seem to be generated at the sea level by marine erosion, whereas the younger ones show a continental origin, maybe related to cold periods of the pleistocene, and were altered under warm-humid climatic conditions, as deduced from the presence of peculiar weathering fronts and as suggested by correlations with the global sea-level changes. parole chiave: geomorfologia strutturale, superfice erosionale, tasso di sollevamento, val melandro, appennino campano-lucano. keywords: structural geomorphology, land surface, uplift rate, melandro valley, southern apennines (italy). il quaternario italian journal of quaternary sciences 19(1), 2006 119-128 120 c. martino & m. schiattarella 1. introduzione negli ultimi anni viene registrato un sempre crescente interesse verso le problematiche relative alle velocità di sollevamento e alle conseguenti implicazioni sull’evoluzione geomorfologia di aree orogeniche. per l’appennino meridionale simili tematiche sono state affrontate, recentemente, con approcci multidisciplinari volti alla comparazione tra sollevamento e smantellamento erosivo (schiattarella et al., 2003, 2006; boenzi et al., 2004). la valle del melandro è una depressione tettonica che si sviluppa in direzione no-se lungo la “zona assiale” (sensu ortolani et al., 1992) della catena sudappenninica. è colmata da sedimenti quaternari che giacciono su due grandi unità tettoniche sovrapposte: l’unità dei monti della maddalena, costituita prevalentemente da carbonati meso-cenozoici di mare basso, a tetto e le unità lagonegresi, formate da successioni pelagiche mesozoico-terziarie, a letto. tali caratteri rendono l’area particolarmente adatta alla stima dei tassi di sollevamento: sono infatti presenti successioni stratigrafiche sufficientemente resistenti all’erosione da conservare diversi elementi morfotettonici relativamente antichi, con particolare riferimento alle superfici erosionali sospese, databili grazie alla presenza di successioni plioceniche e pleistoceniche. l’evoluzione geomorfologica della valle del melandro è stata fortemente condizionata da più fasi di sollevamento, peraltro caratterizzate da un differente comportamento dei due fianchi del bacino. infatti, nel corso del pleistocene inferiore, il versante in destra orografica si è sollevato più velocemente rispetto a quello opposto, mentre a partire dal pleistocene medio – è avvenuto il contrario. nella valle e sui rilievi contigui sono stati distinti quattro ordini di superfici erosionali con peculiari caratteristiche morfologiche, che differiscono tra i monti della maddalena in sinistra orografica ed il fianco opposto in terreni lagonegresi. tali elementi morfotettonici, datati grazie ai rapporti con i depositi plio-pleistocenici, sono stati utilizzati nella stima dei tassi di sollevamento. quest’ultimi sono stati calcolati usando la differenza di quota tra superfici erosionali ed il livello di base assoluto (livello del mare) e locale (talweg attuale). inoltre, sono stati stimati i tassi di sollevamento per intervalli temporali compresi tra due fasi erosive consecutive (tasso di sollevamento “partizionato” o stage uplift rate di schiattarella et al., 2006), considerando la differenza di quota tra un dato ordine di superficie e quello immediatamente più giovane. 2. inquadramento geologico e geomorfologico l’area investigata è una piccola porzione del prisma di accrezione sud-appenninico derivante dalla deformazione di diverse unità paleogeografiche ubicate lungo il margine passivo mesozoico della placca adriatica e della copertura ofiolitifera proveniente da un adiacente braccio dell’oceano tetideo (d’argenio et al., 1986; sgrosso, 1988; pescatore et al., 1999, tra gli altri). le differenti unità tettoniche sono sovrascorse l’una sull’altra con vergenza adriatica. da ovest verso est si riconoscono: i) le unità interne, che rappresentano un prisma di accrezione oligo-miocenico con blocchi di ofioliti, corredato da depositi sintettonici del miocene inferiore; ii) la piattaforma appenninica; iii) le unità lagonegresi, derivanti dalla deformazione del bacino omonimo; iv) le unità irpine, depositatesi in bacini satellite e di avanfossa nel miocene medio-superiore al di sopra delle unità lagonegresi deformate; v) la piattaforma apula. la deformazione delle differenti unità paleogeografiche è iniziata secondo alcuni autori nel miocene inferiore (d’argenio et al., 1986; patacca & scandone, 2001, tra gli altri) e per altri nell’oligocene superiore (pescatore et al., 1999) ed è proseguita con la migrazione di sovrascorrimenti, bacini di thrust-top ed avanfosse sino al pleistocene (pieri et al., 1997; patacca & scandone, 2001, tra gli altri). l’edificio appenninico così strutturato è stato ampiamente dislocato da faglie ad alto angolo, plio-quaternarie trascorrenti ed estensionali (schiattarella, 1998). il sollevamento dell’appennino meridionale è strettamente collegato alle fasi tettoniche plio-pleistoceniche avvenute all’interno del sistema mar tirreno – catena. nel pliocene medio si è sviluppata una importante fase tettonica (ortolani, 1978), marcata tra l’altro da una vistosa discordanza angolare nel bacino dell’ofanto (giannandrea, 2003). durante il pliocene superiore domina il fagliamento trascorrente (russo & schiattarella, 1992; ascione & cinque, 1995) con la formazione di alti e bassi strutturali secondo i meccanismi della trastensione e della traspressione (ortolani et al., 1992). in questo periodo ha luogo la subsidenza del bacino di vavilov (sartori, 1989) ed un modesto sollevamento del settore peritirrenico della catena accompagnato dalla formazione dei bacini del golfo di salerno, della piana del fiume garigliano e di quella del fiume volturno (brancaccio et al., 1991). i sollevamenti più significativi, però, iniziano con il pleistocene, in coincidenza di due importanti fasi parossistiche. la prima, sviluppatasi a partire dall’inizio del pleistocene inferiore, è caratterizzata da forti sollevamenti in catena e dalla contemporanea sedimentazione di imponenti serie clastiche continentali quali i conglomerati di auletta (ascione et al., 1992), i conglomerati di eboli (brancaccio et al., 1991) e i depositi del pergolamelandro (lippman provansal, 1987; santangelo, 1991) e marine (d’argenio et al., 1986; brancaccio et al., 1991). una seconda fase parossistica accompagna l’inizio del pleistocene medio con notevoli sollevamenti differenziali che hanno portato ad una disorganizzazione della rete idrografica con la formazione di diversi bacini intermontani lacustri quali, ad esempio, il vallo di diano e il bacino di acerno (d’argenio et al., 1986; brancaccio et al., 1991). durante gli intervalli freddi del pleistocene medio si assiste alla rapida evoluzione delle scarpate di faglia per recessione rettilineo-parallela lungo l’intera fascia peritirrenica (brancaccio et al., 1979) ed i detriti generati ingombrano le valli e colmano i bacini lacustri determinando gli imponenti accumuli clastici attualmente terrazzati e riconoscibili in tutti i bassi morfologici. nel periodo compreso tra le due fasi parossistiche registrate nel mar tirreno ha luogo la subsidenza del bacino dei marsili, a partire da 1.3 ma (sartori, 1989), mentre i fenomeni di uplift si propagano anche nei settori più esterni della catena, nella fossa bradanica e nell’avanpaese (westaway, 1993). in questo stesso periodo, una “fase” tettonica in catena, iniziata 1.2 ma, è responsabile del sollevamento delle superfici erosionali del pliocene superiore e pleistocene inferiore (schiattarella et al., 2003). durante il pleistocene superiore si assiste ad una sostanziale stabilità del settore peritirrenico, come testimoniato dai terrazzi tirreniani posti pochi metri sul livello del mare lungo tutta la costa (cosentino & gliozzi, 1988; bordoni & valensise, 1998; tra gli altri). in questo periodo si sollevano principalmente la zona assiale, il fronte della catena, la fossa bradanica e settori dell’avampaese (cosentino & gliozzi, 1988; westaway, 1993; bordoni & valensise, 1998; cucci & cinti, 1998; amato, 2000; schiattarella et al., 2003, 2006). la depressione tettonica della valle del melandro rappresenta uno dei diversi bacini intermontani pleistocenici dell’appennino meridionale (fig. 1). tra i bacini posti lungo la zona assiale della catena, è l’unico con depositi di età infrapleistocenica (lippman provansal, 121aspetti morfotettonici ... 1987), mentre gli altri (vallo di diano, alta val d’agri, bacino del mercure) sono non più antichi del pleistocene medio. bacini di età comparabile sono invece ubicati lungo il settore tirrenico della catena (bacino di auletta, area dei conglomerati di eboli). la valle del melandro è aggradata da depositi alluvionali del pleistocene inferiore (lippman provansal, 1987) distinti in tre unità litostratigrafiche separate da paleosuoli e superfici di erosione (giano & martino, 2003). tali depositi sono spianati da una superficie erosionale che si estende, seppure in modo frammentato, lungo tutto l’asse vallivo e si raccorda con i versanti dei rilievi adiacenti (martino, 2005). oltre alla superficie impostata sui depositi continentali del bacino, sono state riconosciute diverse superfici di spianamento sia sui monti delle maddalena, a quote superiori ai 1000 m, che sui monti che delimitano la valle ad oriente, tra gli 800-900 m e i 1100-1300 m (santangelo, 1991). fig. 1 carta geologica schematica del bacino del fiume melandro. geological sketch map of the melandro river basin. 122 3. analisi morfostrutturale i margini del bacino della valle del melandro sono contraddistinti da un andamento molto irregolare a causa di un’evoluzione tettonica polifasica (fig. 1). dall’analisi statistica delle mesofaglie rilevate in massima parte nel massiccio carbonatico dei monti della maddalena è stato possibile osservare una cinematica polifasica per tutte le principali famiglie di faglia (fig. 2). alcune faglie mostrano un carattere sin-sedimentario rispetto ai depositi alluvionali del pleifig. 2 diagramma a rosetta delle mesofaglie misurate nell’area del bacino del fiume melandro e frequenza relativa delle cinematiche delle faglie. rose diagram of the mesoscopic faults from the study area and frequency of kinematic behaviour of fault sets. fig. 3 carta morfostrutturale del bacino del fiume melandro. morphostructural map of the melandro river basin. c. martino & m. schiattarella 123 stocene inferiore (giano & martino, 2003). nell’ambito del bacino e dei rilievi al contorno sono stati individuati quattro ordini di superfici (fig. 3) che decrescono di quota sia lungo il fianco occidentale (monti della maddalena) che lungo quello orientale (fig. 4). l’ordine più antico (s1) corrisponde alla paleosuperficie auctt. di età altopliocenica: sulla sommità della dorsale dei monti della maddalena, e segnatamente in località la conca, rasa infatti depositi marini del pliocene inferiore-medio. morfologicamente incastrate nel paleopaesaggio s1 appaiono le superfici s2, s3 ed s4. le superfici s3 rasano il riempimento continentale del bacino della valle del melandro, datato al pleistocene inferiore (lippman provansal, 1987): ciò permette di attribuire tale ordine alla parte alta del pleistocene inferiore. le superfici s2, interposte tra quelle s1 ed s3, sono conseguentemente attribuibili al pleistocene inferiore. infine, le superfici s4 sono state certamente disattivate nel pleistocene superiore, in accordo con quanto rilevato in aree limitrofe da schiattarella et al. (2003), e pertanto la loro genesi può essere compresa tra la parte alta del pleistocene medio e il pleistocene superiore. le superfici s1, modellate nel pliocene superiore, sono state tettonicamente sbloccate durante l’inizio del pleistocene inferiore (brancaccio et al. , 1991; schiattarella et al. , 2003), mentre quelle s2, che si sono formate prima della deposizione del riempimento continentale del bacino della valle del melandro, hanno iniziato a sollevarsi durante l’episodio tettonico emiliano (d’argenio et al., 1986), ed in particolare in corrispondenza dell’intervallo 1.2-1.3 ma (sartori, 1989, 1990; schiattarella et al., 2003). i glacis erosionali s3, modellati dopo l’aggradazione del bacino ad opera dei depositi alluvionali, si sono sollevati al debutto del pleistocene medio (brancaccio et al., 1991; schiattarella et al., 2003), mentre i terrazzi erosionali s4, morfologicamente incastrati nei precedenti, hanno subito un sollevamento durante il pleistocene superiore (0.125 ma in bordoni & valensise, 1998, e schiattarella et al., fig. 4 a: panoramica dei monti della maddalena. è possibile osservare la paleosuperficie auctt. (s1), che rasa la sommità della dorsale carbonatica, e le superfici s2 ed s3 in essa morfologicamente incastrate. b: panoramica della destra orografica del bacino. è possibile osservare la superficie sommitale (s1) che rasa i rilievi modellati nella successione mesozoica lagonegrese. incastrate nel paesaggio della paleosuperficie sommitale sono ben evidenti le superfici più giovani s2 ed s3. a: general view of the maddalena mts: note the highest and oldest palaeosurface (s1) cutting the top of the carbonate ridge, and the younger and lower s2 and s3 land surfaces. b: general view of the right flank of the basin: note the summit land surface cutting the top of the mountains formed of lagonegro units, and the younger and lower s2 and s3 land surfaces. fig. 5 esempi di profili morfostratigrafici trasversali al bacino, utilizzati per la stima dei tassi di sollevamento. examples of morphostratigraphic cross-sections through the basin used for the estimate of uplift rates. 2003). la stima dei tassi di uplift, calcolati sulla base della distribuzione altimetrica delle superfici sopra discusse, dei profili morfostratigrafici che ne derivano (fig. 5), e dell’attribuzione dei marker a range di età aspetti morfotettonici ... 124 relativamente ristretti (fig. 6), ha permesso di apprezzare una differente dinamica del sollevamento per i due fianchi del bacino: nel corso del pleistocene inferiore, il versante in destra orografica si solleva più velocemente rispetto a quello opposto, mentre a partire dal pleistocene medio avviene il contrario. in generale, i tassi di sollevamento calcolati per l’intero bacino della valle del melandro hanno messo in evidenza un decremento dei valori tra il pleistocene inferiore e quello medio, considerando il sollevamento locale e “partizionato”, a differenza dei dati relativi al sollevamento regionale che descrivono un trend crescente a partire dall’inizio del pleistocene. la comparazione tra le quote dei relitti di superfici erosionali con il profilo longitudinale del fiume sele (fig. 7a), a partire dal torrente pergola (affluente del fiume melandro, che fa appunto parte del sistema idrografico a recapito tirrenico del sele), ha permesso di ipotizzare una formazione in ambiente genetico fluviale e ben al di sopra del livello del mare delle superfici s3 ed s4. queste presentano, infatti, un andamento conforme a quello del profilo longitudinale del fiume sele. le superfici s1 ed s2 hanno, invece, un andamento molto regolare e prossimo all’orizzontalità (fig. 7), come possibile conseguenza di una formazione in corrispondenza del livello del mare e geneticamente legata all’azione dell’abrasione marina. queste considerazioni permettono di operare una correzione alla stima dei tassi di sollevamento regionale per le superfici s3, sulla base della differenza di quota che intercorre tra tali superfici ed il paleo-livello di base relativo alla parte alta del pleistocene inferiore, impostato sui conglomerati di eboli (brancaccio et al., 1991). tale correzione modifica l’andamento del tasso di sollevamento regionale e lo rende congruente con i tassi di uplift locale e “partizionato” (fig. 8). inoltre, il tasso di sollevamento regionale così corretto calcolato a 1.2 ma risulta essere pari a circa 1 mm/a, che è un valore corrispondente al tasso di subsidenza del bacino di marsili, stimato per lo stesso periodo da sartori (1989). le superfici s1 sono riconducibil i al la paleosuperficie auctt. a sviluppo regionale, la cui formazione è avvenuta durante il pliocene superiore. in questo periodo il rilievo era molto modesto (bartolini, 2003), per cui le oscillazioni positive del livello del mare hanno giocato un ruolo fondamentale nello spianamento di aree molto ampie (fig. 9). un discorso analogo sembra valere anche per le superfici s2, che in parte sono state modellate sempre in corrispondenza del livello del mare a partire dalle morfologie dei paleopaesaggi altopliocenici e quindi ereditate dalle superfici s1. considerando un intervallo temporale di formazione per la superficie s1 di almeno 0.4-0.5 ma, che termina a 1.8 ma con l’inizio del sollevamento, si può osservare dalla curva eustatica che in questo periodo il livello del mare si trovava mediamente a -40 m rispetto all’attuale (fig. 10). all’interno di questo intervallo temporale vi sono state almeno cinque importanti oscillazioni positive del livello del mare (rispetto ai -40 m), che con ogni probabilità hanno giocato un ruolo fondamentale nel modellamento della superficie. per le superfici s2 si può ipotizzare un periodo di formazione più breve (circa 0.25 ma), essendo queste in parte il prodotto del rimodellamento di quelle s1, come segnalato per la vicina area della val d’agri (boenzi et al., 2004). la comparafig. 6 diagrammi relativi alle variazioni nel tempo dei tassi di sollevamento regionali, locali e locali partizionati stimati per l’area del bacino del fiume melandro. diagrams showing the variations during the quaternary of regional, local and stage uplift rates from the melandro basin area. zione con la curva eustatica suggerisce che le superfici s2, sollevate a partire da 1.2 ma (schiattarella et al., 2003), si sono formate in un periodo in cui il livello del mare si trovava mediamente a -60 m. probabilmente gran parte del modellamento è avvenuto ai due estremi di tale intervallo temporale, in coincidenza di due significative risalite del livello del mare (fig. 10). le superfici s3 ed s4 sono state modellate a quote di alcune centinaia di metri al di sopra del livello del mare (fig. 7), presumibilmente durante periodi freddi, come ipotizzato da lippman provansal (1987) per la formazione dei glacis corrispondenti alle superfici s3, avvenuta in ambiente periglaciale. il fatto che in simili contesti morfoclimatici si possono formare aree pedemontane sub-pianeggianti molto ampie è in accordo con l’estensione delle superfici s3 ed il loro raccordo morfologico a profilo concavo con i versanti adiacenti (fig. 11). i glacis erosionali s3 sono caratterizzati da un carapace di alterazione spesso alcuni metri. in corrispondenza delle alluvioni del pleistocene inferiore, tale orizzonte è caratterizzato da una generale ossidazione dei depositi che conferisce una tipica colorazione rossastra. laddove la superficie s3 insiste sul substrato c. martino & m. schiattarella 125 fig. 7 a) comparazione del profilo longitudinale del fiume sele -torrente pergola con i lembi dei diversi ordini di superfici erosionali relitte; b) ricostruzione della paleomorfologia delle stesse superfici effettuata sulla base della restituzione del rigetto delle faglie. a) comparison of longitudinal stream profile of the sele-pergola rivers and land-surface relicts; b) palaeomorphological reconstruction of land surfaces by fault displacement restoration. fig. 8 tasso di sollevamento regionale corretto sulla base della ricostruzione dei paleolivelli di base dell’erosione (cfr. fig. 8). base-level-corrected regional uplift rate (cf. fig. 8). fig. 9 diagramma a blocchi della possibile genesi multitemporale delle superfici erosionali s1 ed s2; a) abrasione marina durante i periodi di oscillazione positiva del livello eustatico; b) successivo modellamento ad opera dei corsi d’acqua. block diagram illustrating the possible two-step origin of the s1 and s2 land surfaces; a) marine erosion during sea-level raising periods; b) subsequent shaping of the surface by fluvial erosion. ➧ aspetti morfotettonici ... pre-quaternario, si può osservare un fronte di weathering spesso 2-3 m, caratterizzato in special modo nei litotipi costituiti da un’alternanza di livelli argillosi e litoidi, come ad esempio nella formazione dei galestri – da blocchi litoidi di varie dimensioni immersi in una matrice argillosa fortemente alterata. inoltre, all’interno della componente argillosa è possibile osservare delle plaghe biancastre, corrispondenti a livelli di precipitazione calcarea prossimi alla superficie, che ricalcano l’andamento della topografia e, segnatamente, delle superfici piane o blandamente ondulate. l’insieme di questi caratteri fa supporre che il carapace di alterazione si sia formato in un clima caldo-umido e con la superficie non ancora dissecata dall’erosione lineare. simili fronti regolitici possono essersi formati poco prima dell’inizio del sollevamento del glacis, periodo in cui si registra un picco eustatico positivo (fig. 10). 4. considerazioni finali il bacino della valle del melandro è caratterizzato da un’evoluzione morfotettonica polifasica che ha determinato una complessa articolazione dei suoi margini. episodi di sollevamento sono intervallati a periodi di stasi durante i quali sono state generate superfici erosionali, organizzate in quattro ordini distribuiti temporalmente dal pliocene superiore al pleistocene superiore. i tassi di sollevamento, calcolati grazie all’attribuzione cronologica per correlazione morfostratigrafica delle superfici ad intervalli temporali sufficientemente vincolati, hanno permesso di evidenziare un comportamento differenziale del sollevamento dei due fianchi del bacino, più rapido in destra orografica durante il pleistocene inferiore e a velocità invertite a partire dal pleistocene medio. in generale, i tassi di uplift calcolati per l’intero bacino della valle del melandro mostrano per il sollevamento locale e “partizionato” un decremento dei valori tra il pleistocene inferiore e quello medio, a differenza dei dati relativi al sollevamento regionale che descrivono un andamento crescente a partire dall’inizio del pleistocene. la ricostruzione del paleolivello di base riferibile alle superfici s3 ed s4 per126 fig. 10 intervalli cronologici in cui si sono modellati i diversi ordini di superfici, nel quadro della curva eustatica plio-quaternaria (modificata da bintanja et al., 2005, per il primo milione di anni; per la restante parte ricavata dalla curva degli isotopi dell’ossigeno di gradstein et al., 2004). time intervals related to the genesis of different land surface, in the frame of the global sea level curve (modified after bintanja et al., 2005, for the last 1 my, and reconstructed for the remaining part by means of marine oxygen-18 isotope curve after gradstein et al., 2004). fig. 11 raccordo concavo tra il versante settentrionale del monte il crocifisso e la superficie s3 di serra murgia longa, impostata sui conglomerati del pleistocene inferiore. concave profile of the northern slope of mt. il crocifisso connected with the s3 land surface of the serra murgia longa lower pleistocene conglomerates. c. martino & m. schiattarella mette di operare una correzione al valore del tasso di sollevamento regionale, che in seguito a questa modifica assume un trend comparabile con quello del sollevamento locale e “partizionato”. la comparazione tra il profilo longitudinale del fiume sele con i lembi delle superfici relitte ha permesso di ipotizzare per le superfici s1 ed s2 una formazione in corrispondenza del livello del mare e per quelle più giovani (s3 ed s4) un modellamento avvenuto alcune centinaia di metri al di sopra del livello di base assoluto. le superfici s1 ed s2 sono state modellate probabilmente durante le oscillazioni positive del livello del mare del pliocene superiore e del pleistocene inferiore. al contrario, le superfici s3 ed s4 sono state scolpite durante fasi climatiche fredde che hanno generato ampi glacis in roccia. inoltre, le superfici s3 sono caratterizzate da uno spesso carapace di alterazione probabilmente prodotto in un clima caldo-umido. si può dunque ipotizzare che il glacis s3 è il prodotto derivante dall’accoppiamento di un regime climatico di tipo periglaciale, che ha favorito lo spianamento, con un successivo periodo caldo-umido, durante il quale è stata alterata la superficie. ringraziamenti gli autori desiderano ringraziare due referee anonimi per gli utili suggerimenti. lavoro finanziato con il contributo cofin prin 2005, unità operativa dell’università della basilicata (resp. m. schiattarella). bibliografia amato a. (2000) estimating pleistocene tectonic uplift rates in the southern apennines (italy) from erosional land surfaces and marine terraces. in: slaymaker o. (ed.), “geomorphology human activity and global enviromental change”. john wiley & sons, new york, 67-87. ascione a. & cinque a. (1995) l’età della tettonica trascorrente nell’appennino campano: il contributo dell’analisi geomorfologica. studi geol. camerti, vol. spec. 1995/2, 41-52. ascione a., cinque a. & tozzi m. (1992) la valle del tanagro (campania): una depressione strutturale ad evoluzione complessa. studi geologici camerti, vol. spec. 1992/1, 209-219. bartolini c. (2003) when did the northern apennine became a mountain chain? quaternary international, 101-102, 75-80. bintanja r., van de wal r. s. w. & oerlemans j. (2005) modelled atmospheric temperature and global sea levels over the past million years. nature, 437, 125-128. boenzi f., capolongo d., cecaro g., d’andrea e., giano s. i., lazzari m. & schiattarella m. (2004) evoluzione geomorfologica polifasica e tassi di sollevamento del bordo sud-occidentale dell’alta val d’agri (appennino meridionale). boll. soc. geol., 123, 357-372. bordoni & valensise (1998) deformation of the 125 ka marine terrace in italy: tectonic implications. in: stewart i. & vita-finzi c. (eds), “late quaternary coastal tectonics”. geological society, london, special publications, 146, 71-110. brancaccio l., cinque a. & sgrosso i. (1979) forma e genesi di alcuni versanti di faglia in rocce carbonatiche: il riscontro naturale di un modello teorico. ren. acc. sc., let. e art. in napoli, 46, 1-21. brancaccio l., cinque a., romano p., rosskopf c., russo f., santangelo n. & santo a. (1991) geomorphology and neotectonic evolution of a sector of tyrrhenian flank of the southern apennines (region of naples, italy). z. geom., suppl-bd, 82, 47-58. cosentino d. & gliozzi e. (1988) considerazioni sulle velocità di sollevamento di depositi eutirreniani dell’italia meridionale e della sicilia. mem. soc. geol. it., 41, 653-665. cucci l. & cinti f. r. (1998) regional uplift and local tectonic deformation recorded by the quaternary marine terraces on ionian coast of northern calabria (southern italy). tectonophysics, 292, 6783. d’argenio b., ortolani f. & pescatore t. (1986) geology of southern apennines. a brief outline. geol. appl. idrogeol., 21, 135-160. giannandrea p. (2003) analisi sedimentologica del sintema di monte sirico (parte alta della successione del bacino dell’ofanto), appennino meridionale, basilicata. il quaternario, 16, 269-277. giano s. i. & martino c. (2003) assetto morfotettonico e morfostratigrafico di alcuni depositi continentali pleistocenici del bacino del pergola-.melandro (appennino lucano). il quaternario, 16, 289-297. gradstein f.m. et al. (2004) a geologic time scale 2004. geological survey of canada, miscellaneous report 86, 1 poster. lippman provansal m. (1987) l’apennin meridional (italie): etude geomorphologique. these de doctorat d’etat en geographye physique, universitè d’aix-marseille. martino c. (2005) studio morfostrutturale e valutazione dei tassi di sollevamento e dei carichi tettonici nell’area del bacino del pergola-melandro (appennino lucano). tesi di dottorato inedita, università della basilicata, pp. 168. ortolani f. (1978) alcune considerazioni sulle fasi tettoniche mioceniche a plioceniche dell’appennino meridionale. boll. soc. geol. it., 97, 609-616. ortolani f., pagliuca s., pepe e., schiattarella m. & toccaceli r. m. (1992) active tectonic in the southern apennines: relationships between cover geometries and basement structure. a hypothesis for a geodynamic model . igcp n. 276, newsletter, 5, 413-419. patacca e. & sscandone p. (2001) late thrust propagation and sedimentary response in the thrust belt-foredeep system of the southern apennines (pliocene-pleistocene). in: vai g.b., martini i.p. (eds): “anatomy of a mountain: the apennines and adjacent mediterranean basins”. kluwer academic publishers, 401-440. pescatore t., renda p., schiattarella m. & tramutoli m. (1999) stratigraphic and structural relationships between meso-cenozoic lagonegro basin and coeval carbonate platforms in southern apennines, italy. tectonophysics, 315, 269-286. 127aspetti morfotettonici ... pieri p., vitale g., beneduce p., doglioni c., gallicchio s., giano s. i., loizzo r., moretti m., prosser g., sabato l., schiattarella m., tramutoli m. & tropeano m. (1997) tettonica quaternaria nell’area bradanico-ionica. il quaternario, 10, 535-542. russo f. & schiattarella m. (1992) osservazioni preliminari sull’evoluzione morfostrutturale del bacino di castrovillari (calabria settentrionale). studi geologici camerti, vol. spec., 1992/1, 271-278. santangelo n. (1991) evoluzione geomorfologica e stratigrafica di alcuni bacini lacustri del confine calabro-lucano (ital ia meridionale) . tesi di dottorato inedita, università “federico ii”, napoli. sartori r. (1989) evoluzione neogenico-recente del bacino tirrenico e suoi rapporti con la geologia delle aree circostanti. giornale di geologia, 51, 139. sartori r. (1990) the main results of odp leg 107 in the frame of neogene to recent geology of perityrrhenian areas. in: kastens k.a., mascle j. et alii (eds.), proc. odp, scientific results, 107, 715730. schiattarella m. (1998) quaternary tectonics of the poll ino ridge, calabria-lucania boundary, southern italy. in: holdsworth r. e., strachan r. a. & dewey j. f. (eds.), continental transpressional and transtensional tectonics. geological society, london, special publications, 135, 341354. schiattarella m., di leo p., beneduce p. & giano s.i. (2003) quaternary uplift vs tectonic loading: a case-study from the lucanian apennine, southern italy. quaternary international, 101-102, 239-251. schiattarella m., di leo p., beneduce p., giano s.i. & martino c. (2006) tectonically driven exhumation of a young orogen: an example from the southern apennines, italy. in: willett s.d., hovius n., brandon m.t. & fisher d. (eds): “tectonics, climate, and landscape evolution”. geological society of america, special paper 398, penrose conference series, 371–385. sgrosso i. (1988) nuovi elementi per un più articolato modello paleogeografico nell’appennino centromeridionale. mem. soc. geol. it., 41, 225-242. westaway r. (1993) quaternary uplift of southern italy. journ. geophys. res., 98, 21741-21772. 128 ms. ricevuto il 6 giugno 2006 testo definitivo ricevuto il 17 ottobre 2006 ms. received: june 6, 2006 final text received: october 17, 2006 c. martino & m. schiattarella imp.bottari& tectonic genesis of the salt marshes on the sicilian coast of the straits of messina (sicily) antonio bottari1, carla bottari2 & pietro carveni3 1osservatorio sismologico, università di messina, via osservatorio 4, 98121 messina, italia. fax +39090363533, 2istituto nazionale di geofisica e vulcanologia, via di vigna murata, 605 00143 roma, italia. fax +39065186507 3dipartimento di scienze geologiche, università di catania, corso italia 57, 95129 catania. fax +39095412646, e-mail carveni@unict.it abstract: bottari a., bottari c. & carveni p., tectonic genesis of the salt marshes on the sicilian coast of the straits of messina (sicily, southern italy). (it issn 0394-3356, 2005). based on historiographical, geophysical and seismological data a detailed geological and geomorphological survey has been carried out to reconstruct the genesis of two sicilian salt marshes. these salt marshes, called pantano piccolo and pantano grande, are located respectively on the northern and southern seashore of the coastal plain of peloro cape. the peloro cape is placed at the northern opening of the straits of messina and together with the two salt marshes, constitute a complex eco-system of great interest because of the multiple implications of anthropic and naturalistic nature. the result of geological and geophysical surveys shows that the origin of these salt marshes was due to the activity of some normal faults that conform peloro cape peninsula and that control the level of coastal plain. the shallow basin of pantano grande (big marsh), has a lengthened shape along the ionian coastline. it is delimited to n by a normal fault that set the limits to s of the horst of granatari hill and to s from some small faults that conform the southern shore. the southern coastline of pantano grande is composed by a narrow strip of alluvium deposits that separate the salt marsh basin by ionian sea; here along the coastline a narrow strip of paleontologically sterile conglomerate outcrops. otherwise, the atypical morphology of pantano piccolo (small marsh) is characterized by a high depth (m = 28 m) compared with its horizontal dimensions; from the bathymetric analysis results that the facing tyrrhenian sea is less deep of the pantano piccolo basin till 600 m far from the coastline. the basin of this salt marsh is situated inside a small semi-graben n-s oriented and it is located in the coastal lowland that conforms to e the peloro cape peninsula. in short, the analysis of geomorphologic characteristics and the results of geological, geophysical and seismological surveys support a tectonic genesis for both the salt marshes. riassunto: bottari a., bottari c. & carveni p., genesi tettonica degli stagni salmastri ubicati sulla costa siciliana dello stretto di messina (sicilia). (it issn 0394-3356, 2005). lo stretto di messina è un graben che dall’inizio del pliocene ha subito un’intensa evoluzione; esso è limitato da un sistema di faglie nne-ssw lungo la costa siciliana e da un sistema di faglie ne-sw lungo quella calabra. la penisola di capo peloro, estrema propagine nord-orientale della sicilia, è situata all’imboccatura settentrionale dello stretto, ed è formata da una zona collinare con sviluppo ew, corrispondente ad un horst, delimitato a settentrione dalla faglia di mortelle ed a meridione dalla faglia di ganzirri; nella zona collinare affiora prevalentemente la formazione di messina, un deposito ghiaioso-sabbioso clinostratificato di facies deltizia, discordante su limitati affioramenti di conglomerati tortoniani, su lembi discontinui della serie gessoso-solfifera messiniana e di trubi infrapliocenici; al disopra della formazione di messina si trovano limitati affioramenti di sabbie a ostrea e, sopra di queste, livelli di sabbie a strombus bubonius. la zona collinare è bordata da una pianura costiera di larghezza variabile. tale pianura, che non supera 4 m di quota, è formata da ghiaie, sabbie e limi; al suo interno si trovano due specchi di acqua salmastra, denominati pantano piccolo e pantano grande, i quali costituiscono un importante e complesso ecosistema, di grande interesse per le molteplici implicazioni di carattere antropico e naturalistico. sulla base di dati di ricerche storiografiche, geofisiche e sismologiche, cui hanno fatto seguito rilievi geologico-geomorfologici di dettaglio, è stata ricostruita la genesi dei due pantani che è da attribuire all’attività di alcune faglie normali: il bacino del pantano grande, poco profondo, con forma a clessidra allungata parallelamente alla linea di costa ionica, è delimitato a settentrione dalla faglia di ganzirri ed a meridione da una serie di piccole faglie che ne conformano la riva; la linea di costa, che delimita a meridione il sottile cordone di depositi alluvionali che separano il pantano grande dal mare ionio, è marcata da un affioramento di conglomerato paleontologicamente sterile. il pantano piccolo presenta una morfologia atipica, caratterizzata da una grande profondità (m = 28 m) paragonata alle dimensioni orizzontali del bacino, da un gradiente batimetrico circa triplo di quello dell’antistante braccio di mar tirrenico che risulta essere meno profondo del pantano piccolo fino ad oltre 600 m dalla linea di costa. in sintesi, l’analisi delle caratteristiche geomorfologiche e dei risultati di indagini geologiche, geofisiche e sismologiche supportano una genesi tettonica per entrambi i pantani. keywords: straits of messina, coastal salt marshes, tectonics, morphologye. parole chiave: stretto di messina, stagni costieri salmastri, tettonica, morfologia. il quaternario italian journal of quaternary sciences 18(2), 2005 113-122 1. introduction the peloro cape peninsula, placed on the sicilian shore of the straits of messina, presents peculiar geomorphological characteristics which make it of notable morphotectonic and landscape interest (fig. 1). it is composed by a hilly zone along an e-w direction, and bounded by a coastal plain of variable width. in particular, the salt marshes of faro and ganzirri, called respectively pantano piccolo (small marsh) (fig. 1: pp) and pantano grande (big marsh) (fig. 1: pg), situated inside the coastal plain, constitute a complex ecosystem of great interest of anthropic and naturalistic nature. recently, the attention of environmental characteristics of this area was enlarged by proposing of realization of a bridge to connect the two shores of the 114 a. bottari, c. bottari & p. carveni straits of messina. among the unsolved problems of prevailing geological interest detaches that one relative to the genesis and evolutional history of the basins of pantano piccolo and pantano grande. with this aim, and starting from analysis of historiographical, geophysical and seismological data, some new geological and geomorphologic surveys have been carried out. 2. historiographic outlines the first known human settlement on the sicilian shore of the straits was located in the area between ganzirri and faro as shown by the finding of some pieces of pot that were brought to light in the 1960s excavation. the dating of this material between 2200-2000 bc provides a terminus post quem for the prehistoric village (biddittu et al., 1979). historical sources of roman age mention that the legendary town of risa, placed on granatari hill, collapsed during an earthquake and its remains fell down in the pantano piccolo. the same sources relate that two temples were once in the area between the two salt marshes. the first one was built by orion and was probably dedicated to neptune. remains of this building were brought to light in 1835, during the digging work of a waterflow to connect pantano grande to pantano piccolo (fig. 2: c3). the second temple was built in a third salt marsh, deep only 0.5 m, located between pantano grande and pantano piccolo. this temple was destroyed in roman times and the salt marsh was filled in (fig. 2: p1). indeed, at around ad 1500, only two marsh existed, pantano piccolo and pantano grande (maurolico, 1543). the material deriving either from the digging work of the first canal or from the digging work of a second canal, which was built in the 18th century to connect pantano piccolo (faro) with the ionian sea (fig. 2: c1), was used to drain a fourth small marsh (fig. 2: p2) which had formed between pantano grande and pantano piccolo (abbruzzese & genovese, 1952). in conclusion, the whole historiographical data documents that the area between the two salt marshes (pantano grande and pantano piccolo) was influenced by local subsidence in the last two thousand years which produced in different times another two small basins at least (fig.1: p1 and p2) that no longer exist as they were filled in by man. 3. geological and structural features of the peloro cape peninsula the peloro cape peninsula is the extreme northeastern tip of sicily, and forms the western shore of the straits of messina in a tract where the minimum distance from the calabrian shore is 3.2 km. the straits of messina is a graben which suffered an intense evolution at the beginning of the pliocene; it is bounded by fault systems in a nne–ssw direction along the sicilian shore and ne-sw fault systems along the calabrian shore; it was partial ly f i l led by transgressive plio–pleistocene deposits on a crystalline allochthofig. 1 geological sketch of the peloro cape peninsula. nous basement and mio-pliocene deposits (jacobacci et al., 1961). most authors affirm that the origin of the straits of messina can be attributed to lowering movements along normal faults which were active in the plio–pleistocene, although different opinions exist about movements along the structures, and for the number of tectonic phases which have resulted in the present day setting of the territory (selli, 1978; bousquet et al., 1980; ghisetti, 1981). the deepest geometrically geological formation in the stratigraphic succession which outcrops in the straits area is formed by pre-mesozoic high grade metamorphites, transposed as nappes in the mid miocene and making up part of the aspromonte unit; in particular, it features pegmatoid gneiss for the sicilian area (atzori et al., 1974) and high grade monzogabbro, augengneiss, paragneiss and micaschists for the calabrian shore (pezzino & puglisi, 1980). neogenic quartenary sediments relating to the filling of subsiding basins formed immediately after the mid – miocene orogenic transport phase, lie in transgression on metamorphic rocks. (barbano et al., 1978; lentini & vezzani, 1978). in particular, the polygenetic sterile base conglomerate evolved as a sandstone – clay alternation of the tortonian age (jacobacci et al., 1961), on which tongues of evaporitic limestone and messinian gypsum lie in sedimentary continuity; trangressional on these is early–pliocene white globigerine 115tectonic genesis of the salt ... marl (trubi) (jacobacci et al., 1961); early–pleistocene limestone deposits lie transgressive on all the formations described (lombardo, 1980 a; 1980 b) and on which lie the early-pleistocene argille di vito superiore; yet discordant on all the terms listed lies clinostratigraphic mid pleistocene gravel and sand from the formazione di messina (lombardo, 1980 a; 1980 b). still in discordance, late pleistocene terraced deposits, both in marine and continental facies, outcrop on this (ghisetti, 1981): the stratigraphic succession is closed and completed by alluvial fans, recent and present-day alluvial and beach deposits. the following succession outcrops in the survey area: 1) the formazione di messina: this consists of clinostratigraphic deposits, mainly delta facies, laterally passing to organogenic sandstone calcarenite, coastal facies sand and gravel; its thickness ranges between 70 and 250 meters; to the west of the study area, the formation lies in discordance on tortonian rocks, on the messinian ones of the serie gessoso solfifera and on trubi; because of faults, it is in contact with the metamorphic rocks of the aspromonte unit; the formazione di messina was recognized to be discordant and transgressive on the substratum (jacobacci et al., 1961) and was ascribed to the early and/or mid pleistocene; according to selli, (1978) it was formed in a river fed deltaic environment; according to sauret (1980) and barrier (1984), it was a regressive and diachronic fig. 2 map of the peloro cape peninsula with the bathymetry of surrounding seas; c1, linking canal between pantano piccolo and the ionian sea, c2, linking canal between pantano piccolo and tyrrhenian sea, c3, linking canal between pantano piccolo and pantano grande, c4, linking canal between pantano grande and ionian sea; p1 and p2 , assumed locations of two ancient marshes which are not more existing; x-y and y-z, shares of the sterile conglomerate outcropping along the shoreline of ganzirri – punta sottile; d1 and d2, geognostic boring locations (modified from carta dello stretto di messina, i.i.m., scale 1:30000). 116 facies due to centripetal progradation towards the centre of the straits, caused by a rapid uplift of the crystalline hinterland; 2) gravel and sand with ostrea: to the east of the papardo river, approximately 60 m above sea level, minute gravel lies in discordance and transgression on clinostratigraphic deposits of the formazione di messina, except for a sub-horizontal surface of marine erosion. this gravel is characterised by the presence of ostrea shells; higher up, this is followed by sand in which specimens of strombus bubonius and glycimeris have been found and which have been attributed to the tyrrhenian; the highest altitude of these sediments is about 85 m (bonfiglio & violanti, 1983); 3) terraced alluvial deposits: these are formed by gravel, sand and reddish silt with alluvial facies; cardium coastal facies are often present at the base; the elements that make up the deposit derive mainly from crystalline rock erosion from the aspromonte unit and secondarily by their sedimentary covering. they were related to tyrrhenian (hugonie, 1974); 4) recent alluvial and coastal plains: this term indicates deposits situated on the edges of naturally formed water channels; they are formed from gravel, sand and silt originating from metamorphic rocks and from the previously described conglomerate and gravel formations; their thickness range from one to tens of meters and occupy the edges of main rivers and the strip of coast that forms the extreme tip of the peloro cape, which enclose the two salt marshes in ganzirri and faro; inside coastal deposits there are lens of sterile conglomerate, about 1m thick, strongly cemented (bonfiglio & violanti, 1983); 5) eluvial and colluvial sheets: this is a strip which extends from the foot of the hilly area for several tens of kilometres and is made up of a brown-reddish, gravellysandy deposit, sometimes in the form of alluvial cones; its litho–structural characteristics and area distribution make it relative to the superimposition of successive accumulations of the slope declivity deriving from the weathering of previous territories; states of various inclinations can be seen along the man made trench, as a consequence of the trend of the sub-stratum; 6) present day alluviums and beaches: present day alluviums are found along the river beds; they originate from the erosion of previous terms and present a variable size; current beaches are formed by gravel fashioned by wave movement and currents. 4. geomorphological characteristics the peloro cape peninsula presents a smooth morphology, related more to the outcropping lithologies than the tectonic structures. it is characterized by a hilly range and a coastal plain which houses two salt marshes (fig. 1). the hilly range is formed by a series of small rises with flat peaks; the watershed descends gradually from the west to the east, separating the northern slope from the southern one. the northern slope is characterised by an average slope of 25% and a series of small streams. the southern slope is less sloping (17%) of the previous one, with numerous small and less pronounced streams. the width of the coastal plain varies from a minimum of 75 m in lido di mortelle on the northern coast, to a maximum of 1,750 m between granatari and peloro cape; the isobaths form a cusp on the extension of this alignment (fig. 1). the different trend of bathymetric gradient along the northern shore of peloro cape peninsula (tyrrhenian sea side) compared with that of southern shore (ionian sea side) is evident (fig.2). the ionian coast from messina to peloro cape is bordered by a coastal plain which is characterized by different morphological features: from messina to the outlet of the guardia river (fig. 1: fg), it lies in a roughly nne-ssw direction, with an approximately straight trend, modelled by small recesses and protrusions and is several tens of meters wide; at the outlet of the guardia river, the coastline diverts clearly towards ene and assumes a straight trend as far as peloro cape. in this last stretch, the width of the coastal plain is still several tens of meters wide as far as ganzirri, and from ganzirri beach to pantano grande it sharply widens reaching approximately 500 m (figs. 1, 2). along this coast the tidal currents which can reaches 7 knots have a strongly erosional influence on the shore (montenat et al., 1987; amore et al., 1988). the active tectonic from upper pleistocene until today carry an important rule in conditioning the geomorphological conformation of this area as pointed out by analysis of the paleoseismicity (valensise & pantosti, 1993), of the deformation/rupture/dislocation of superficial terrains observed after strong seismic events (lo perfido, 1909; baratta, 1910) and of the focal mechanism of earthquakes. the straits of messina area is characterized by high values of magnitude (m) of the strongest earthquakes occurred in the last 220 years (7.0 ≤ m ≤ 7.2). the 1908 seismic event (m = 7.2) was the most catastrophic event of the last century, with epicentre in the straits, focal depth h = 18 km and seismogenetic rupture along the ne-sw direction which was 45 km long and 14 km wide. the focal mechanism was normal with a strike-slip component, consistent with distensive stress condition (bottari et al.., 1986; bottari et al., 1989). among the major coseismic effects observed after the 1908 earthquake in the mesoseismic area should be pointed out the lowering of peloro cape terrains of about 20 cm, the subsidence/ ruptures along the southern slope of granatari hill and the underwater landslides along the ionic coast (lo perfido, 1909; baratta, 1910). the lengthening of the isosismal lines in ne-sw direction of the near field of earthquakes with origin in the straits is consistent with the analysis of focal mechanism and the geostructural framework of this area (bottari et al., 1984). the most recent earthquakes (4.0 ≤ m ≤ 4.7), which occurred between 1975 and 1995, with hypocentral depth encompassed between 8 and 21 km, show either normal or strike-slip focal mechanism along the ne-sw direction and in some case along e-w direction (caccamo et al., 1996: neri et al., 1996; frepoli & amato, 2000). therefore, analysis of intensity distributions and focal mechanisms of earthquakes originating in the area of the straits shows the actual seismogenetic activity of faults of the ne-sw structural system but also of tectonic structures with e-w trend. a. bottari, c. bottari & p. carveni 117 5. the salt marshes 5.1 pantano piccolo pantano piccolo is the deepest natural basin of sicily. it presents an almost rectangular shape with the major diagonal oriented in a nw-se direction where it reaches a length of about 650 m (fig. 3). the bathymetric trend of this marsh is asymmetrical, as noted also by abbruzzese & genovese (1952): starting from the western shore, the depth increases very little and gradually from 0 until some meters at a distance of 250 m from the coast; the maximum depth m = -28 m is found in the central eastern area of the basin (fig. 3). the same authors put forward the hypothesis that the genesis of the basin was tectonic, due to the collapse of its base. the basin, placed inside the northern sector of the coastal plain is bounded to w by a nw-se normal fault, with a ne dipping (fig. 1: h) and to e by two small ne-sw normal faults which lower to nw (fig. 1: i, l). these faults were pointed out through seismic surveys (del ben, 1985). to north the basin of the small marsh is separated from the tyrrhenian sea from a strip of beach deposits, primarily gravel-sandy, 150 m wide. the width of the actual beach is of around 70-80 m and the corresponding back beach is characterized by low elevation that locally do not reach 1 m above sea level. for the protection of such places from the west sea storms in different times banks in masonry and more recently in relief of gravels and sands were realized. the bathymetric gradient of the tyrrhenian sea overlooking the northern shore of the small marsh is 3-4 times smaller of that in relief in the lake basin: the bathymetric line of -10 m, that in the tyrrhenian sea is located at around 200 m from the coastline, in the small marsh is placed at around 55 m from the northern shore; the maximum depth m = -28 m, that in the basin it is located at around 240 m from the northern shore, in the sea it usually is located at around 600 m by the line of coast. toward the end of the 18th century, the small marsh and the ionian sea were connected through the construction of a channel (fig. 2: c1) ; in 1962 it was also connected to the tyrrhenian sea (fig. 2: c2). both the digging works were realized for favouring the development of the harvest of mussels. the northern coast of peloro cape peninsula, from acquarone to the mortelle beach, is modelled by a normal fault (fig. 1: i), that lowers to north, that was mapped from jacobacci (1961), bonfiglio & violanti (1983) and del ben & finetti (1985). nevertheless the trend of bathymetric lines overlooking the northern coastal lowland seems us compatible with his prolongation to east to peloro cape. the strong asymmetry of the marsh bathymetry, the steep slope of the northern and eastern shores and the maximum depth value, which is the greatest of all natural basins of sicily, support the hypothesis of a tectonic genesis. 5.2 pantano grande pantano grande in ganzirri is a small and shallow coastal basin (surface, 0.34 km2, maximum depth, 6.5 m, 1.67 km long, and approximately 0.28 km wide, roughly rectangular in shape, with a rapport to the extension equal to 5.9) and its biggest sides run parallel to the coastline (figs. 2, 4). it is located to the north of ganzirri village, where the coastal plain is approximately 500 m wide and it is separated from the sea by a strip of holocene alluvium deposits formed by silt, sand and gravel (gargano, 1994) on which aeolian deposits outcrop (bonfiglio & violanti, 1983). as regard the genesis of the big marsh we should consider that for the development of a coastal lake we needed: (1) a submerged coastal zone and many inlets; (2) a very shallow sea; (3) fluvial mouths which provide remarkable amount of sands and/or gravels. in this condition, it is possible to get a coastal bar at a short distance from the coast, next to an inlet. the bar develops to a tombolo and the bay become a lagoon or a fig. 3 pantano piccolo salt marsh: above, map of the isobaths (continuous curve distance 5 m and dot curves distance 1 m, maximum depth m = 28 m); below, altimetric-bathymetric profiles along a-b and c-d shares (derived from abbruzzese & genovese, 1952). fig. 4 pantano grande salt marsh: above, map of the isobaths (continuous curve distance 1 m); below, altimetricbathymetric profile along m-n share. tectonic genesis of the salt ... 118 coastal pond. the general features of a coastal pond are: low shores and shallow depth and finally a lengthened shape parallel to the coastline. for such morphological characteristics of pantano grande basin, and particularly for the shallow depth of its waters could be preliminary supposed that it is a coastal basin (fig. 4). it could be formed by an amassing of sands and gravels which were carried away and after deposited by the sea currents and wave motion. however the other conditions are not satisfied. the straits of messina results to be uplifting (westaway, 1993), there are not inlets and there are not water-courses to convey enough amount of sands and gravels. besides the sea depth along the coasts increases sensibly with the distance from the seashore (figs. 1, 2). consequently a sedimentary genesis for the pantano grande cannot be proposed. concerning the sediments that form the submerged beach, colantoni (1987) reports a dimension encompassed between medium size sand and gravel. according to amore et al. (1988) the submerged beach is formed by sands whose medium size is 1.8÷2.0 mm, while the emerged beach is prevalently constitutes by sand. the portion of the coastal plain where is located pantano grande is interested from two faults with direction ene-wsw, partly already noticed by gargano (1994) and from lentini et al. (1998; 2000): in the maps of these authors the faults, that are here indicated with the letter a and b, are interrupted at 2 km to wsw from the pantano grande (fig. 1). del ben (1985) and del ben & finetti (1985) noticed, through investigations of high-resolution seismic surveys, that on prolongation of fault b there is a direct fault, with rejection of around 10 m and a lower southern block (fig. 1: g). this fault, that is located to some tens of meters upstream of the northern shore of the pantano grande (fig. 1), will be subsequently indicated as faglia di ganzirri. it was shown up during two seismic profiles denominated ms2 and ms7 (figs. 5, 6), and it extends to north till the small marsh. this fault displaces of about 10 m the refractor horizon “a” placed at the top of sub-weathering in the gravels and sands of the formazione di messina. in addition, the same authors have revealed that some small normal faults nw dipping model the southern shore of the salt marsh (fig. 1: d, e, f); some direct faults on the prolongation of fault a, approximately parallel to the coastline, fault downward the straits (fig. 1). the basin is transversally bound by the extension of two direct faults, parallel to each other, and which make up part of an ene–wsw oriented system (lentini et al., 1998). the same authors indicated that a doubtful fault (fig. 1: c), with the same direction, which was located adjacently to the greatest axis of pantano grande. gargano (1994) reported the same faults (a and b), but did not recognize any fault along the pantano grande basin. as observed, and together with an analysis of the geomorphological characteristics of the peloro cape area, the coastal plain is bounded by two direct fault plans ene–wsw oriented. the first one (fig. 1: g) is situated along the nw shore of the pantano grande, fig. 5 sm-2 seismic high resolution profile along c-d share (fig. 1): a) diagram of the intercept-times; b) seismic section (after del ben & finetti, 1985). a. bottari, c. bottari & p. carveni above the mentioned holocene deposits and in contact with the underlying mid-pleistocene formazione di messina. this fault plan is not visible anymore due to the intense urbanisation experienced by the site, to the scarce mechanical characteristics of the formations and to the existence of a colluvium covering. the second fault, on an extension of a, situated to the south of the southern shore of the basin and parallel to b, conforms the coastline between the outlet of the guardia river and peloro cape (fig. 1: a’). 5. new data and surveys summarizing, the results of the morphological characteristics, tectonic elements and seismic surveys mentioned above, indicate that the ionian coastal plain is bound by two direct faults, parallel to each other and ene–wsw oriented, with the edge that lowers towards the sse. the basin of pantano grande is situated inside such a step: the northernmost of the two faults conforms the northern shore of pantano grande, while the southern shore is conformed by some small faults (del ben, 1985) which lower towards nw (fig. 1, d, e and f). a wide substratum of steri le conglomerate beneath sea level (fig. 7) prevalently outcrops along the waterline between ganzirri and faro; it has been mapped during an underwater survey. the outcrop (fig. 8) bound a strip of beach 2.3 km long, from pantano grande to punta sottile. the average width of the outcrop measures approximately 20 m, with a maximum values around 35 m and thickness up to 3 m. such a value is greater than that already ascertained from boreholes drilled to the ne, near punta sottile (fig. 2: s1), where intercalations of coarse pebble conglomerate present a thickness of about 50 cm which were found within the sand and gravel deposits (bonfiglio & violanti, 1983). according to the same authors this deposit is a beach rock. conversely, this conglomerate is missing in a layer 30 m thick, formed by medium size sand and grey polygenetic gravels with lens of mud in the upper part, investigated during geognostic boring carried out 300 m to west of la torretta (servizi tecnici s.p.a. fintecna gruppo iri, 1999; fig. 9). with its squashed funnel shape, pantano piccolo presents a bathymetric trend that can be justified by assuming that the basin was formed by a tectonic pro119 fig. 6 sm-7 seismic high resolution profile along e-f share (fig. 1): a) diagram of the intercept-times; b) seismic section (after del ben & finetti, 1985). fig. 7 particular of the mid-pleistocene sterile pebble conglomerate outcropping along ganzirri shoreline. tectonic genesis of the salt ... cess connected with the activity of the faults that conform to the peloro cape peninsula. the strong acclivity of the bottom along an e-w direction near the centre of the basin corresponds to a direct fault oriented approximately nnw–sse, that lowers towards ene and was reported by del ben (1985) and del ben & finetti (1985). samples taken from the marsh bottom next to bathymetric line of – 5m, on the edge of the scarp that bounds the southwestern sector of the basin, show that they were formed by conglomerate presumably belonging to the formazione di messina. as a whole, the data from literature and the results of various tests carried out in the study area allow to define the geological section of the area of study (fig. 10). the direct fault along the northern shore of pantano grande (fig.1: g) is supported by the previously mentioned geophysical surveys such as the small faults (fig. 1: d, e and f) which bound it to the south, and are compatible with the evidence of local subsidence derived from historiographical documentation; the existence of the fault which conforms to the coastline (fig. 1: a’) is supported by the morphological analysis and the results of geophysical exploration (del ben, 1985). 6. conclusive suggestions the observation reveal that the genesis of the pantano piccolo and pantano grande basins is markedly tectonic, as supported by the following points: a) the hilly relief located upstream of pantano grande, makes up a small horst bound by faults ene–wsw oriented; the northern fault constitutes the limit of the mortelle coastal plain on the tyrrhenian sea slope (fig. 1: i); the less evident southern fault (faglia di ganzirri; fig. 1: g) delimits the northern shore of pantano grande. the lengthened shape of the basin 120 fig. 8 map of the mid-pleistocene sterile pebble conglomerate outcropping along ganzirri shoreline (above) and ganzirri-punta sottile shoreline (below). fig. 9 shallow stratigraphy resulting from geognostic boring 300 m at w of la torretta (d2 , in fig. 2). a. bottari, c. bottari & p. carveni parallel to ganzirri fault direction and the contiguous location of this fault with the basin are substantial elements which configure the causal nexus about the tectonic genesis of pantano grande. besides, with reference to the remains of ancient temple uncovered at a few meters depth during the digging work of a canal between pantano piccolo and pantano grande and of present-day molluscs of brackish environment brought to light during well borings in margi, show that level was correspondent to the bottom of one or more ancient small marshes which at the present-day are not anymore existing. such evidence are to be related to local subsidence processes activated by movement of the direct fault of ganzirri; (b) the transversal dimension of pantano grande is bound to the north by the above mentioned g fault and to the south by some small direct faults which lower towards the nnw (fig. 1: d, e, f); another normal fault ene–wsw oriented, and which lowers towards the sse, model the ionian coastline from the outlet of the guardia river to peloro cape (fig. 1: a’); c) the basin of pantano piccolo, located in the northern coastal plain, is characterised by a conspicuous depth compared to its horizontal dimensions, by a marked asymmetry of the isobaths and by a steep slope acclivity of northern and eastern shores. in the eastern sector of the basin, where the depth reaches the maximum value, the bathymetric trend along the we profile suffers a rough increase and the depth by an initial value of -1.5 reaches -28 m. in this portion the bathymetric trend is three times of that observed along the tyrrhenian shore. the basin is located in a semigraben, formed by a direct fault nw-se oriented and ne dipping (fig.1: h) and by two direct small faults nesw oriented and nw dipping (fig. 1: i, l ). in conclusion, the analysis of geomorphological features of pantano piccolo correlated to those of the area in which the salt marsh is placed is consistent with a tectonic genesis. acknowledgments this work was financially supported by pra 2003 ateneo di messina (a. bottari) and m.i.u.r. in the framework of morpho-dynamics of seismically active coastal zone (p. carveni). references abbruzzese d. & genovese s. (1952) osservazioni geomorfologiche e fisico-chimiche sui laghi di ganzirri e di faro. boll. pesca, piscicoltura e idrobiologia, anno xxvii, 7 (1), 3-20. amore c., di geronimo i., giuffrida e. & randazzo g. (1988) atlante spiagge italiane, foglio 254 (messina – reggio calabria) . c.n.r., p.f. conservazione del suolo – sottoprogetto dinamica dei litorali. atzori p., d’amico c. & pezzino a. (1974) relazione geopetrografica preliminare sul cristallino della catena peloritana. riv. min. sic., 25, 1-8. baratta m. (1910) la catastrofe sismica calabro messinese (28 dicembre 1908), relazione alla società geografica italiana, roma. barrier p. (1984) evolution tectono-sédimentaire pliocène et pleistocène du détroit de messine. thése un. marseille, 270 pp. biddittu i., bonfiglio l. & riccobono f. (1979) eneolitico di facies di piano conte a ganzirri (capo peloro, messina). sicilia archeologica, 12 (40), 87-90. bonfiglio l. & violanti d. (1983) prima segnalazione di tirreniano ed evoluzione pleistocenica di capo peloro (sicilia nord-orientale). geogr. fis. dinam. quat., 6, 3-15. bottari a., federico b. & lo giudice e. (1984) the correlation between the macroseismic attenuation trend and the geo-structural framework: the calabropeloritan arc as an example . tectonophysics, 108, 33-49. bottari a., carapezza e., carapezza m., carveni p., cefali f., lo giudice e. & pandolfo c. (1986). the 1908 messina earthquake in the regional geostructural framework. j. geodynamics, 5, 275-302. bottari a., capuano p., de natale g., gasparini p., neri g., pingue f. & scarpa r. (1989) source parameters of earthquakes in the straits of messina, italy, during this century. tectonophysics, 166, 221234. bousquet j.c., carveni p., lanzafame g., philip h. & tortorici l. (1980) la distension pléistocène sur le bord oriental du détroit de messine: analogies entre les résultats microtectoniques et le mécanisme au foyer du séisme de 1908. boll. soc. géol. france, 22 (3), 327-336. 121 fig. 10 a-b geological cross-section of the peloro cape peninsula (fig. 1): 1, al luvial deposits (holocene); 2, terraced deposits (late pleistocene); 3, sand and gravel of the formazione di messina (mid-pleistocene); 4, normal fault. tectonic genesis of the salt ... caccamo d., neri g., saraò a. & wiss m. (1996) estimates of stress directions by inversion of earthquake fault-plan solution in sicily, geophis. j. int., 125, 857-868. colantoni p. (1987) marine geology of straits of messina. documents et travaux institut geologique albert de lapparent, paris, 11, 191209. del ben a. (1985) technical report n°85001. stretto di messina s.p.a., roma. del ben a. & finetti i. (1985) technical report n° 850016. stretto di messina s.p.a., roma. frepoli a. & amato a. (2000) fault plane solutions of crustal earthquakes in southern italy (1988-1995): seismotectonic implications, ann. geofis., 43 (3), 437-467. gargano c. (1994) carta geologica di messina e del settore nord-orientale dei monti peloritani (sicilia n.e.), scala 1:25.000, s.el.ca., firenze. ghisetti f. (1981) l’evoluzione strutturale del bacino plio-pleistocenico di reggio calabria nel quadro geodinamico dell’arco calabro. boll. soc. geol. it., 100, 433-466. jacobacci a., malatesta a. & motta s. (1961) piano di studi sullo stretto di messina per il collegamento della sicilia con la calabria: ricerche geologiche. ires, palermo, 66 pp. hugonie g. (1974) le relief de la region de messine (sicile). méditerranée, 1, 43-61. lentini f. & vezzani l. (1978) tentativo di elaborazione di uno schema strutturale della sicilia orientale. mem. soc. geol. it., 19, 495-500. lentini f., caliri a., carbone m.s., carveni p., catalano s., gargano c., lentini r., strazzulla s. & vinci g. (1998) carta geologico-strutturale della sicilia nord-orientale. scala 1 :100.000. se.l.ca., firenze. lentini f., caliri a., carbone m.s., carveni p., catalano s., gargano c., grasso m., la manna f., lentini r., strazzulla s., vinci g. & vinciguerra g. (2000) carta geologica della provincia di messina. scala 1:50.000. se.l.ca., firenze. lombardo g. (1980 a) stratigrafia dei depositi pleistocenici della sicilia nord-orientale. att. acc. gioenia sc. nat. catania, 12, 84-113. lombardo g. (1980 b) stratigrafia del plio-pleistocene nella zona di reggio calabria. att. acc. gioenia sc. nat. catania, 12, 233-298. lo perfido a. (1909) livellazione geometrica di precisione eseguita dall’i.g.m. sulla costa orientale della sicilia da catania a messina, a gesso ed a capo peloro, sulla costa occidentale della calabria da gioia tauro a melito di porto salvo, per incarico del ministro dell’agricoltura, industria e commercio, relazione alla commissione della reale accademia dei lincei, 35 p. maurolico f. (1543) lettera ad petrum gillium (from panormi apud ignatium virzì by facciolà, 1893). montenat c., barrier p. & di geronimo i. (1987) the strait of messina, past and present: a review. in le détroit de messine (italie): evolution tectonosédimentaire récente et environnement actuel. doc. et trav. igal, paris, 11, 272 p. neri g., caccamo d., cocina o. & montalto a. (1996) geodynamic implications of earthquake data in the southern tyrrhenian sea. tectonophysics, 258, 233-249. pezzino a. & puglisi g. (1980) indagine geologicopetrografica sul cristallino dell’aspromonte centro settentrionale (calabria). boll. soc. geol. it., 99, 255-268. sauret b. (1980) contribution à l’étude néotectonique du détroit de messine (italie, sectur de reggio calabria). thése 3me cycle, univ. paris, vii, 1258. selli r. (1978) geologia e sismotettonica dello stretto di messina. convegno su: l’attraversamento dello stretto di messina e la sua fattibilità, 4-6 luglio 1978. att. acc. naz. lincei, 43, 119-154. servizi tecnici s.p.a. fintecna gruppo iri (1999) perizia di variante e suppletiva al progetto (n° l16) per la realizzazione della stazione media di messina ganzirri: relazione geologica. ministero del ll.pp, roma, 17 p. valensise g. & pantosti d. (1992) a 125 kyr-long geological record of seismic source repeatability: the messina straits (southern italy) and the 1908 earthquake (ms 71/2). terra nova, 4, 472-483. westaway r. (1993) quaternary uplift of southern italy. j.g.r., 98, 21741-21772. 122 ms. ricevuto il 1° febbraio 2005 testo definitivo ricevuto il 2 settembre 2005 ms. received: february 1, 2005 final text received: september 2, 2005. a. bottari, c. bottari & p. carveni imp.gordini& i depositi cementati del golfo di trieste (adriatico settentrionale): distribuzione areale, caratteri geomorfologici e indagini acustiche ad alta risoluzione emiliano gordini1, ruggero marocco2, giorgio tunis2 & riccardo ramella1 1istituto nazionale di oceanografia e di geofisica sperimentale ogs, trieste egordini@ogs.trieste.it rramella@ogs.trieste.it 2dipartimento di scienze geologiche, ambientali e marine, università degli studi di trieste -marocco@units.it tunis@units.it riassunto: e. gordini, r. marocco, g. tunis & r. ramella, i depositi cementati del golfo di trieste (adriatico settentrionale): distribuzione areale, caratteri geomorfologici e indagini acustiche ad alta risoluzione. it issn 0394-3356, 2004. l’elevato numero (ca. 250) d’affioramenti rocciosi individuati nei fondali poco profondi del golfo di trieste, la loro distribuzione areale e i loro caratteri morfologici essenziali hanno permesso di formulare alcune ipotesi sulla loro genesi e, più in generale, sulle vicende geologiche che hanno interessato questa parte più settentrionale dell’alto adriatico. questi veri e propri geositi che sotto vari punti di vista arricchiscono l’ambiente marino delimitato dalle acque slovene e croate, si distribuiscono essenzialmente nell’ampia fascia delle sabbie di piattaforma (d’orientazione ne-sw) e in quest’ambito maggiormente (85%) nel versante che degrada verso le profondità maggiori. analoghe ricerche eseguite sul golfo di venezia e nel versante sloveno dell’alto adriatico, fanno ritenere che queste rocce siano molto diffuse (sull’ordine delle migliaia) e che la loro presenza condizioni la morfologia e la vita acquatica di questo mare. nell’area indagata la maggioranza degli affioramenti presenta una tipologia essenzialmente tabulare e subordinatamente a “panettone” e pinnacoli; la loro concentrazione massima è di 3,2 affioramenti per km2. l’analisi statistica elementare effettuata su un numero rappresentativo di affioramenti ha evidenziato che essi si rinvengono a profondità mediamente pari a 17,1 m (min 8,3 e max 21,5 m), e presentano spessori compresi tra un massimo di 2,7 ad un minimo di 0,4 m (medio 1,0 m). la tipologia di affioramento è stata definita in otto classi che comprendono forme essenzialmente tabulari (con quattro sottoclassi; da a a d, complessivamente 89%), a panettone (e, 1%) e pinnacolari (f, pari al 10%). la classe tabulare è stata suddivisa ulteriormente a seconda della disposizione rispetto al fondale (apicale su alti morfologici, intensamente fratturato con nucleo più esteso, compatto e tondeggiante, assetto inclinato) nelle forme b1 (27%), b2 (10%), b3 (36%) e c (6%) mentre a seconda dello spessore, forma ed associazione con altri affioramenti nella tipologia d (9%). raramente questi fondi duri si rinvengono nelle aree di bassura sottomarina (6%) o alla sommità delle trezze (secche, 9% circa), sempre però nell’immediato intorno delle sabbie di piattaforma (36 % sulle sabbie pelitiche e l’1% nelle peliti molto sabbiose). in questa fase della ricerca di particolare importanza si sono rivelate le osservazioni dirette in immersione che hanno palesato ammassi di concrezioni organogene poggianti su substrati costituiti da lastroni di sabbia cementata, adagiati o affioranti sul fondale sabbioso. questi presentano solitamente fratture ortogonali alla stratificazione, altre ad andamento casuale e quasi sempre più o meno profonde nicchie d’erosione alla base che non fanno intravedere, però, una continuità con il substrato. per far questo si è impiegata la metodologia sub-bottom profile chirp che ha permesso di indagare con notevole dettaglio l’assetto sedimentario del sottofondo marino (da 7 a 14 m ca.), con una risoluzione compresa tra 20 e 30 cm. emerge che la maggioranza degli affioramenti tabulari presenta un limitato o talvolta quasi assente sviluppo radicale, che si esaurisce all’interno del materasso sabbioso riconducibile al tetto dei depositi continentali del sistema lst (30-40 cm dal fondo). anche gli affioramenti a forma di “panettone”, che presentano radici più profonde, sono radicati ai depositi continentali del corpo sedimentario lst, costituito da facies acustiche prevalentemente piano parallele, variabili in ampiezza e frequenza, con orizzonti torbosi e una diffusa presenza di gas, manifestata da evidenti lacune acustiche tipiche. anche in superficie, sulla verticale degli affioramenti a volte si riscontrano emanazioni di gas e sul fondo si sono riconosciute macchie di solfo-batteri che porterebbero ad ipotizzare una genesi per ossidazione del metano. ulteriori studi sono attualmente in corso al fine di verificare tali ipotesi. sulla base dei dati raccolti e soprattutto dalle risultanze delle prime analisi dei campioni di roccia si è propensi a ritenere che gli affioramenti rocciosi del golfo di trieste siano un insieme di forme poligeniche (costituite da depositi litorali e marini, ma anche alluvionali) messe a giorno dalla trasgressione versiliana e poi rielaborate dai processi biologici e geomorfici attualmente in atto sui fondali adriatici. abstract: e. gordini, r. marocco, g. tunis & r. ramella, the cemented deposits of the trieste gulf (northern adriatic sea): areal distribution, geomorphologic characteristics and heigh resolution seismic. it issn 0394-3356, 2004. echo-sounding profiles, lateral scanning echo-sounding surveys and scuba divings carried out in several years allowed the identification of at least 250 rocky outcrops in the gulf of trieste. the analysis of the areal distribution and of the main geomorphic characteristics (extension, shape, thickness, etc.) showed that these very peculiar rocks lie beyond the coastal sedimentary prism (13 to 21 m depth), in correspondence to the shelf sands, displaying a ne-sw direction, reaching the gulf of venice. the rocky outcrops are located, almost in continuum, along the southern sides of the banks (the morphological reliefs called “trezze”), and on the small depressions among them, where they reach the maximum values of density of about three outcrops squared kilometres. the outcrops are made of sandstone and they emerge from shelf sands usually (73%) showing planar-tabular morphotypes (with clear stratification), sometimes massive or pinacular, always covered by cap reefs. bubbling reefs, locally defined as “bromboli” are rarely present. their mean thickness is one metre and they show a preferential elongation following the 13, 16 and 19 m bathymetric countours. the statistical analysis performed on morpho-sedimentological parameters characterising these subaqueous outcrops has shown that they are essentially strictly related to the morphology and the water depth such as sediment texture and outcropping type. on the basis of specific characteristics, the rocky outcrops can be divided, at least, into four main groups. direct diving observations highlighted that sandstones are often fractured orthogonally to stratification and appear associated to more irregular trends and small caves or erosional niches at the base. these fractures do not reveal the presence of roots nor do they suggest a further extension under the sea-bed. the sub-bottom profile chirp methodology appeared a good application in the definition of the buried geometric characteristics of these numerous rock outcrops present in the seafloor of the trieste gulf, but also allowed to define a good sedimentological characterization of the sub-surficial sediments. the acoustic penetration of the seismic signal is varying from 7 to 14 meters being notably influenced by the type of investigated sediment, while the resolution range is between 20 and 30 cm. from this study it has emerged that the investigated rock outcrops reveal a limited, or sometimes absent radical development within il quaternario italian journal of quaternary sciences 17(2/2), 2004, 555-563 556 e. gordini et al. 1. introduzione da tempo si sta indagando sugli affioramenti rocciosi del golfo di trieste. in lavori precedenti e attraverso indagini essenzialmente dirette si è messo in evidenza la distribuzione areale e i variegati aspetti morfologici di questi fondi duri che sono una ricchezza biologica per l’alto adriatico (caressa et al., 2001; gordini et al., 2003), tanto da giustificare un inserimento di questi geotopi in aree marine vincolate (fig. 2). la ricerca è proseguita poi, con diverse campagne marine incentrate su indagini indirette (side scan sonar, ecoscandaglio digitale, sub-bottom profiler chirp; gordini et al., in stampa) e dirette (immersioni subacquee, campionature dei sedimenti e delle rocce) attualmente in fase di elaborazione. i risultati fino ad ora raggiunti non permettono di definire con precisione la genesi di questi affioramenti subacquei che secondo altri autori (colantoni et al., 1998; stefanon & zuppi, 2000; conti et al., 2002) sono il prodotto dell’ossidazione del metano fuoriuscito dal sottofondo marino, tramite un meccanismo diagenetico analogo a quello individuato nei mari del nord da jensen et al., 1992 (bubbling reef). l’elevato numero d’affioramenti individuati in una relativamente ristretta area del golfo di trieste, delimitato dai confini con la slovenia e croazia, e i caratteri d’insieme degli affioramenti (estensione, forma, potenza, fatturazione, ecc), inducono ad ipotizzare un insieme di forme poligeniche (costituite da depositi litorali e marini, ma anche alluvionali, “messi a giorno” dalla trasgressione versiliana), rielaborate dai processi biologici e geomorfici attualmente in atto sui fondali adriatici. l’analisi del cemento delle rocce e del gas che gorgoglia dal fondo del mare, oggetto di una prossima ricerca, dovrebbe dar risposta a questi quesiti. 2. generalità ed acquisizione dei dati per l’individuazione degli affioramenti rocciosi si sono utilizzate le numerose segnalazioni dei pescatori e dei subacquei che sono state in parte verificate, poi, con una serie di strisciate batimetriche e side scan sonar. preziosa sotto questo punto di vista è stata la collaborazione con il sub nino caressa di grado che ha fornito circa 250 segnalazioni di affioramenti rocciosi, determinate con traguardi a terra, coordinate loran, e ultimamente, rilevamenti gps (caressa et al., 2001). tutti questi siti sono stati schedati secondo coordinate geografiche, profondità del fondale e spessore (potenza) dell’affioramento; sono state calcolate inoltre la distanza dalla costa e la tipologia morfologica e sedimentologica del fondale circostante. caressa ha fornito anche una succinta descrizione degli affioramenti che ha permesso una prima classificazione della loro forma (caressa et al., 2001). tutti questi dati sono stati, in seguito, verificati in immersione. il rilievo batimetrico è stato eseguito con la m/n “castorino 2” (fig. 1), utilizzando un ecografo x – 16 computer sonar lowrence e un ecoscandaglio digitale lowrence x16c digital computer sonar. la posizione è stata definita in tempo reale con strumentazione gps e dgps. il posizionamento è stato quindi elaborato con un software di navigazione: l’errore planimetrico medio è stato stimato essere inferiore a 5 m. la registrazione del fondo marino è stata corretta considerando la profondità del sensore dell’ecoscandaglio, l’escursione della marea, riportando il valore così ottenuto al livello medio mare locale (trieste). l’errore di profondità stimato è di 10 +/5 cm. in seguito all’individuazione delle aree d’affioramento, su alcuni siti, ritenuti più interessanti, sono stati eseguiti rilievi side scan sonar ed immersioni subacquee. il sistema side scan sonar utilizzato è quello della transceiver unit della edgetech df-1000 dci kit interfacciato con workstation coda octopus; il digital tow fish è della edgetech df-1000 saf-t-link™ digital towfish, con doppia frequenza simultanea di acquisizione 100/500khz. il software utilizzato per l’elaborazione dei dati è il coda geosurvey mosaic. il tow fish è stato trainato a poppa dell’imbarcazione a circa 6 m di profondità e ad una distanza di 15 m. la differenza di posizione tra il “pesce” e l’antenna gps è stata calcolata e inserita nel programma attraverso il software d’acquisizione dati. per il rilievo subacqueo degli affioramenti sono state adottate le normali tecniche scuba. durante le operazioni in immersione, particolare attenzione è stata rivolta alla descrizione della forma dell’affioramento, alla presenza di stratificazioni al letto della roccia, alla disposizione delle fratture e alla presenza, o meno, di fenomeni di gorgogliamento di gas dal substrato. si è passato quindi alla campionatura della roccia e dei sedimenti nell’intorno. the sandy mattress, of the system tst (transgressive sistem tract). the thickness of the rocky outcrops (about 1 m) puts them of to the top of the continental deposits of the lst. in this situation the most reasonable hypothesis about their genesis is referable to lithification processes in the ancient lowland before the sea transgression or to recent cementation processes of the sea foundation. then, they outcropped and underwent the colonization of calcareous algas, briozoas and serpulidi, which provideld actual configuration. the sedimentary body lst is constituted by acoustic facies marked by parallel reflections. they appear predominantly plain, of varying amplitude and frequency, with the main reflectors few meters spaced and thin packages, characterized by less reflectivity. in this alluvial sedimentary blanket, peat horizons and a diffused presence of gas have been recognized, as revealed by transparent facies in the seismic profiles. on the basis of the above data, as preliminary results, due to the high number of surveyed and hypothesised rocky outcrops along with their shape and areal distributions, it is presumed that they were not produced by a single process, but that several different processes interacted on the littoral and marine environment, as well as on alluvial deposits of the paleo-plain, which outcropped as the consequence of the versilian transgression. parole chiave: affioramenti rocciosi, geomorfologia subacquea, facies acustiche, golfo di trieste, italia. keywords: rock outcrops, subacqueous geomorphology, acoustic facies, trieste gulf, italy. grazie a questi rilievi il quadro delle conoscenze sui geotopi ha raggiunto un buon livello e in particolare ha permesso di elaborare statisticamente le informazioni ottenute (elaborazione eseguita su 104 affioramenti dei 250 segnalati inizialmente) e di raggruppare gli affioramenti in otto tipologie morfologiche (caressa et al., 2001). a completamento della ricerca è stata promossa una campagna di indagine acustica ad alta risoluzione nel sottofondo marino utilizzando il sub-bottom profiler chirp (cap-6600 della datasonics con tow vehicle ttv190). la configurazione adottata ha permesso di acquisire contemporaneamente il segnale acustico su due bande di frequenza differenti, rispettivamente con sweeps da 2 a 7 khz e pattern radiativo conico di 45° e simultaneamente anche con sweeps da 8 a 23 khz con cono da 30°. il tow vehicle è stato trainato a poppavia dell’imbarcazione, ad una profondità di 3 m dalla superficie ed ad una distanza di 12 m. la penetrazione ottenuta varia da 7 a 14 m essendo notevolmente influenzata dai diversi tipi di sedimento indagato; la risoluzione è stata mediamente compresa tra 20 e 30 cm. 3. breve inquadramento geologico le caratteristiche del fondo e del sottofondo del golfo di trieste sono il risultato di processi evolutivi tardo-pleistocenici ed olocenici che hanno visto da un lato la progressiva ingressione marina postglaciale e 557i depositi cementati del ... dall’altro l’aggradazione della costa alluvionale, alimentata dai paleofiumi tagliamento ed isonzo, due dei più importanti fiumi dell’italia settentrionale (colantoni et al., 1985; marocco, 1991). la situazione attuale del golfo palesa la presenza lungo costa di un primo esteso prisma sedimentario che copre una fascia continua che va dall’apparato deltizio isontino (ad est) al delta del fiume tagliamento ed oltre (ad ovest), fino alla profondità di ca. 12-13 m (gordini et al., 2003). questo corpo sedimentario presenta la classica stratigrafia di conoide progradazionale ed è costituito da sedimenti fluviali attuali/recenti, rielaborati continuamente dal moto ondoso e dalle correnti litoranee. il prisma sedimentario costiero rappresenta il tratto finale del sistema hst (highstend system tract) che termina in una zona sub-pianeggiante e mossa per la presenza di rilievi sabbiosi e affioramenti rocciosi che si inseriscono nell’ambito dei depositi trasgressivi del tst (trasgressive system tract). la sottile coltre dei depositi trasgressivi (variabile da 30 a 40 cm, salvo valori particolari di 1,5 m in corrispondenza di dune sommerse) assume, in corrispondenza dell’alto morfologico della trezza grande, massima potenza (6 m) e definisce un cono deltizio annegato in seguito all’innalzamento del livello marino nel tardiglaciale (gordini et al., 2002). questi depositi sono sabbie medie e mediofini, carbonatiche derivate da sedimenti rielaborati dalla trasgressione marina (colantoni et al., 1985; marocco, 1991). sono ricchi di frammenti organogeni, alghe calcaree, spugne, molluschi, echinodermi, briozoi, ecc. fig. 1 schema del sistema d’acquisizione dei rilievi acustici (batimetrici, side scan sonar, chirp). sketch of the acoustic profiles acquisition system (echo-sounding, side scan sonar, chirp). 558 essi presentano, nel loro limitato spessore, una gradazione normale con all’interno livelli di tritume conchigliare ad indicare una trazione da parte di correnti di fondo e, in altri casi, contatti erosivi tra sedimenti grossolani e sedimenti pelitico-torbosi continentali. l’età dei depositi trasgressivi non è stata determinata analiticamente; sulla base di considerazioni climatiche ed eustatiche generali e in relazione alla età di formazione del delta tilaventino (marocco,1991) e della laguna di caorle, nel retroterra (ca. 9.000 anni; marocco et al., 1996; galassi & marocco, 1999), si può ritenere che almeno l’annegamento del corpo sedimentario della trezza sia avvenuto tra i 16.000 e 11.300 anni fa (gordini et al., 2002). i depositi sabbiosi sormontano con contatti netti il corpo dei sedimenti pelitico -torbosi continentali del sottofondo, ascrivibili al sistema lst (lowstand system tract) e con età pleniglaciale (da 19.945 a 22.120 anni bp; sempre gordini et al., 2002). per la descrizione morfo-sedimentologica dei fondali del golfo di trieste si rimanda a gordini et al. (2003) e caressa et al. (2001). per quanto riguarda gli studi eseguiti sugli affioramenti rocciosi dell’alto adriatico si rimanda a stefanon (1967); stefanon (1979); braga & stefanon (1969); stefanon & mozzi (1972; 1973) newton & stefanon (1975;1976); boldrin (1979) e recentemente da colantoni et al. (1998); mizzan (1999) oltre a caressa et al. (2001) e gordini et al., in stampa. 4. sintesi dei risultati un primo risultato conseguito da questa ricerca (ancora in corso) è stato l’identificazione di un cospicuo numero di campi d’affioramenti rocciosi, ognuno costituito da più rocce singole, molto ravvicinate e solo in parte conosciute dagli autori precedenti. pertanto questi affioramenti non sono singoli ammassi rocciosi che spuntano dal fondale, ma gruppi di rocce, tutte con caratteristiche abbastanza simili che si estendono su vasti areali marini (fig. 2). solamente le formazioni a “panettone” che sono molto estese (50-80 m), si presentano singolarmente o al massimo in coppia. su un centinaio di campi di rocce sottomarine e sui panettoni è stata condotta un’analisi morfologica quantitativa degli elementi più rappresentativi (forma, estensione, profondità, distanza dalla costa, tessitura e morfologia del fondale circostante, ecc). dalla distribuzione areale dei campi di rocce emerge un andamento abbastanza disperso nell’ambito del golfo, con punti o allineamenti di concentrazione nella direzione ne-sw, che coincide con l’area di distribuzione delle sabbie di piattaforma. quest’area è stata contraddistinta da generali fenomeni d’erosione dei sedimenti superficiali, avvenuta con forte intensità durante la fase trasgressiva postglaciale e ancora presente in forma più lieve in concomitanza con le mareggiate più e. gordini et al. fig. 2 – distribuzione e tipologia degli affioramenti rocciosi nel golfo di trieste. distribution and types of the rocky outcrops in the gulf of trieste. 559 violente. nell’ambito di questo trend distributivo, sembrano assumere particolare valenza i locali allineamenti fra affioramenti morfologicamente simili, distribuiti secondo l’andamento delle batimetriche 13, 16 e 19 m. la concentrazione massima di queste rocce è di 3,2 affioramenti per km2. statisticamente (fig. 3) si rinvengono mediamente a 17,1 m (min 8,3 e max 21,5 m), con spessori compresi tra un massimo di 2,7 ad un minimo di 0,4 m (medio 1,0 m). raramente questi fondi duri si rinvengono nelle aree di basso morfologico o avvallamenti sottomarini (6%) o alla sommità delle trezze (secche, 9% circa), sempre però nell’immediato intorno alle sabbie di piattaforma (36 % sulle sabbie pelitiche e l’1% nelle peliti molto sabbiose). la distanza massima dalla costa è risultata di ca. 17 km, quella minima di 2 e quella media di 10 km. la tipologia d’affioramento è stata definita in otto classi (fig 3 e 4) che comprendono forme essenziali depositi cementati del ... fig. 3 – distribuzione di frequenza dei principali parametri che caratterizzano gli affioramenti rocciosi del golfo di trieste. frequency distribution of the main parameters characterising the rocky outcrops in the gulf of trieste. fig. 4 (a sinistra, 4a) tabella riassuntiva dei principali caratteri morfologici e geometrici degli affioramenti rocciosi del golfo di trieste (da caressa et al., 2001 modificato). (a destra, 4b) fotografie delle varie tipologie morfologiche. (left, 4a) the main morphological features of the rock outcrops in the trieste gulf (from caressa et al., 2001 modified). (right, 4b) photographs of the different morphological typologies. a) b) 560 mente tabulari (con quattro sottoclassi; da a a d, complessivamente 89%), a panettone (e, 1%) e pinnacolari (f, pari al 10%). la classe tabulare è stata suddivisa ulteriormente a seconda della disposizione rispetto al fondale e alle fatturazioni presenti (apicale su alti morfologici, intensamente fratturato con nucleo più esteso, compatto e tondeggiante) nelle tre forme b1 (27%), b2 (10%) e b3 (36%; fig. 5); mentre le tipologie c (6%; affioramenti inclinati), d ( circolari , abbinati a pinnacoli; 9%); ed e (1 %; panettoni) e, infine f (10 %; pinnacoli). l’indagine in immersione ha confermato quanto riportato da studi precedenti (stefanon, 1967; braga & stefanon, 1969; stefanon & mozzi, 1972; stefanon & mozzi, 1973; newton & stefanon, 1975; newton & stefanon, 1976; boldrin, 1979), ovvero il ricoprimento organogeno da parte d’individui costruttori (lithophillum, peyssonelia e lithothamnium) di un substrato solido sabbioso, non sempre ben visibile, ma quando rilevabile caratterizzato da una marcata stratificazione piano parallela, resa più evidente da fenomeni d’erosione selettiva. si è constatato, inoltre, che i litosomi sono incisi da profonde fenditure per l’intero spessore e che assumono andamenti quasi sempre ortogonali alla stratificazione. l’origine di tali fenditure sembra essere recente e da ricercarsi nell’azione erosiva delle correnti di fondo che scalzano alla base la roccia cementata, determinando una prima fenditura e poi il crollo delle parti sospese. da queste indagini non è stato possibile e. gordini et al. fig. 5 – mosaico di sonogrammi a scansione laterale di un gruppo d’affioramenti di tipo “b3 tabulare”. mosaic lateral scanning echosouding diagram showing an outcrop group “ tabular b3” type. fig. 6 – operazioni di campionatura delle rocce (destra) e sezione di un campione (sinistra). rocks sampling (right) and sample section (left). definire la profondità del letto dell’affioramento che risulta annegato sui sedimenti del fondo. analisi eseguite sui campioni di roccia (in fase di perfezionamento) e sui sedimenti evidenziano una analogia mineralogica e granulometrica dei depositi cementati con le sabbie di piattaforma adiacenti. le rocce sono arenarie fini, grano o fango sostenute, con minimo cemento carbonatico, ricristallizzato (fig. 6). da un punto di vista paleontologico le rocce sono prive di macro e microfaune ad eccezione di pochi casi. al fine di verificare il radicamento di questi affioramenti rocciosi nel sottofondo e per indagare sulla loro possibile continuità con i depositi trasgressivi superficiali (del sistema tst) o con quelli più profondi (del sistema lst) è stata utilizzata la metodologia sub-bottom profile chirp (fig. 7). e’ emerso che la maggioranza 561i depositi cementati del ... fig. 7 indagine acustica sub-bottom profiler chirp (2-7 khz). (a) rappresentazione 3d; (b) mappa del fondale marino (prospezione con ecoscandaglio digitale); (c) profilo acustico (e interpretazione) eseguito in corrispondenza di due affioramenti rocciosi (a-b). il profilo evidenzia la tipica forma a panettone di questa tipologia morfologica d’affioramento. in particolare mostra una soluzione di continuità tra i due affioramenti rocciosi presenti, sottolineata dall’ottima penetrazione del segnale nella successione sedimentaria intermedia. i corpi rocciosi presentano radici estese all’interno della coltre sedimentaria superficiale; (d, e) profili acustici (e interpretazioni) eseguiti perpendicolarmente alla direzione di massimo sviluppo degli affioramenti rocciosi (c-d ed e-f ). i due transetti evidenziano molto bene la geometria tabulare degli orizzonti sedimentari presenti nell’area di indagine, interrotti solamente dalle tipiche lacune acustiche in presenza di corpi rocciosi superficiali (c-d). la presenza di riflettori acustici irregolari è determinata essenzialmente da accumuli di gas intrappolato all’interno dei sedimenti. sub-bottom profiler chirp (2-7 khz) survey. (a) 3d sketch; (b) seafloor map (digital echosounder survey); (c) sonar profile (and the interpretation) performed across two rock outcrops (a-b). the profile shows the typical “panettone – christmas sweet bread” shape of these rock outcrops. in particular a good continuity between the rock outcrops is shown. it is underlined by the good penetration of the signal within the stratigraphic sequence. the rocky bodies introduce wider roots inside the superficial sedimentary blanket; (d, e) sonar profile (and the interpretations) performed perpendicular to the direction of the rocky outcrops maximum development (c-d and e-f). the two profiles underline well the tabular geometry of the sedimentary section, locally interrupted by acoustic gaps due to surficial rocky bodies (c-d). the presence of irregular acoustic reflectors is determined by accumulations of gas within the sediments. degli rock outcrops a forma tabulare presentano una limitata potenza (ca. 1 m) e un ridotto o talvolta assente sviluppo radicale, ben visibile all’interno del materasso sabbioso riconducibile al sistema tst. le radici degli affioramenti quasi sempre si esauriscono al tetto dei depositi continentali del lst che si trovano a 30-40 cm dal fondo. anche gli affioramenti a forma di “panettone”, più radicati, sembrano prendere origine da questi depositi continentali con processi analoghi a quelli visti per gli affioramenti tabulari. il corpo sedimentario lst viene contraddistinto da facies acustiche contrassegnate da riflessioni prevalentemente piano parallele, variabili in ampiezza e frequenza, in cui i riflettori principali appaiono spaziati di alcuni metri e livelli decimetrici, indicanti superfici meno riflettenti. in questa coltre sedimentaria alluvionale si riconoscono orizzonti torbosi e una diffusa presenza di gas manifestata da evidenti lacune acustiche tipiche. in estrema sintesi, i dati fino ad ora raccolti portano a ritenere che almeno per alcuni di questi litosomi sembra accertata un’origine per cementazione dei clasti per ossidazione del metano contenuto nel sottosuolo. lo stanno a dimostrare le manifestazioni gassose che si rinvengono sulla loro verticale (bromboli), le sacche di gas individuate nel sottosuolo e la presenza di solfo batteri che si rinvengono al loro intorno (fig. 8). anche altri studi eseguiti nell’area (e anche in aree finitime, come il golfo di venezia e l’adriatico in generale) da autori precedenti hanno evidenziato la stessa genesi per alcuni affioramenti indagati. al momento però dall’analisi degli affioramenti del golfo di trieste non si arriva ad una certificazione analitica di questa genesi, in quanto le indagini sul cemento sono estremamente problematiche a causa della scarsità di materiale reperibile e da processare con i normali metodi della geochimica isotopica. rimane, comunque, la constatazione che non tutti gli affioramenti individuati sono connessi a sacche di gas riconosciute nel sottosuolo. a ciò si aggiunga che il gran numero di campi d’affioramenti sottomarini individuati, ognuno con diverse rocce singole, la loro diversità di forma, il loro scarso radicamento sul sottofondo marino, la coincidenza a volte con la presenza di mattes di posidonia oceanica morta e, a complicare ancora di più la situazione, l’analogia di alcune rocce con i livelli cementati dei suoli (pan), mentre per altre con componenti organogene, la similitudine con le attuali sabbie di piattaforma inducono a supporre una diversità di genesi di questi litosomi nell’ambito dello stesso ambiente marino e in quello continentale sottostante. non si esclude, pertanto, che oltre alla cementazione in loco di depositi continentali legati alla fuoriuscita di gas metano, originato probabilmente da processi di decomposizione delle torbe depostesi durante l’ultima glaciazione würmiana, altri possibili processi di cementazione precoce siano intervenuti nei depositi del sottofondo e fondo marino del golfo di trieste. in via del tutto preliminare si ritiene che questi processi possono essere ricercati in: • una cementazione di depositi sabbiosi marino-litorali, avvenuta all’interno dell’antico prisma sedimentario costiero e sulle antiche linee di riva; • una venuta a giorno, per erosione della coltre sedimentaria soprastante, di depositi alluvionali cementati inclusi nel materasso sabbioso della paleopianura tardiglaciale; • una cementazione dei depositi sottostanti le praterie di posidonia oceanica una volta abbondanti in questi mari e attualmente scomparse per cause ancora dibattute. le indagini programmate per il prossimo futuro dovranno dare risposta a queste ipotesi. 562 e. gordini et al. fig. 8 presenza di chiazze biancastre batteriche sul fondo marino in corrispondenza delle emanazioni gassose. photograph showing the presence of white bacterial mats on the seabed in an area of active gas seepage. bibliografia boldrin a. (1979) aspetti ecologici delle formazioni rocciose dell’alto adriatico. atti del conv. sc. naz. p.f. ocean. e fondi mar., 3, 1197-1207. braga g. & stefanon a. (1969) beachrock ed alto adriatico: aspetti paleogeografici, climatici, morfologici ed ecologici del problema. atti ist. ven. sc. lett. art. cxxvii, 351-359. caressa s., gordini e., marocco r.& tunis g. (2001) caratteri geomorfologici degli affioramenti rocciosi del golfo di trieste (adriatico settentrionale). gortania, 23, 5-29. colantoni p., fanzutti g.p. & marocco r. (1985) geologia della piattaforma adriatica . p.f. oceanografia e fondi marini, 49-85. colantoni p., gabbianelli g., ceffa l. & ceccolini c. (1998) bottom features and gas seepages in the adriatic sea . estratto da: v international conference on gas in marine sediments, 28-31. conti a., stefanon a. & zuppi g.m. (2002) gas seeps and rock formation in the northern adriatic sea. cont. shelf res., 22, 2333-2344. galassi p.& marocco r. (1999) relative sea-level rise, sediment accumulation and subsidence in the caorle lagoon (northern adriatic sea, italy) during the holocene. il quaternario, 12 (2), 249-256. gordini e., marocco r. & vio e. (2002) stratigrafia del sottosuolo della “trezza grande” (golfo di trieste, adriatico settentrionale). gortania, 24, 31-63. gordini e., caressa s. & marocco r. (2003) nuova carta morfo-sedimentologica del golfo di trieste (da punta tagliamento alla foce dell’isonzo). gortania, 25, 5-29. gordini e., ramella r., romeo r., deponte m. & marocco r., (in stampa) indagini acustiche sugli affioramenti rocciosi del golfo di trieste (adriatico settentrionale). gortania. jensen p., aagaard i., burke jr r. a., dando p. r., jorgensen n. o., kuijpers a., laier t., o’hara s. c. m. & schmaljohann r. (1992) bubbling reefs in the kattegat: submarine landscapes of carbonate-cemented rocks support a diverse ecosystem at methane seeps. mar. ecol. prog. ser, 83, 103-112. marocco r. (1991) evoluzione tardopleistocenica-olocenica del delta del f. tagliamento e delle lagune di marano e grado, (golfo di trieste). il quaternario, 4(1b), 223-232. marocco r., melis r., montenegro m.e., pugliese n., vio e. & lenardon g. (1996) holocene evolution of the caorle barrier-lagoon (northern adriatic sea, italy). riv. ital. pal. strat., 102 (3), 385-396. mizzan l. (1999) localizzazione e caratterizzazione di affioramenti rocciosi delle coste veneziane. primi risultati di un progetto di indagine. boll. mus. civ. st. nat. ven., 50, 195-212. newton r. & stefanon a. (1975) the “tenue de ciosa” area: patch reefs in the northern adriatic sea. mar. geol., 8, 27-33. newton r. & stefanon a. (1976) primi risultati dell’uso simultaneo in alto adriatico di side scan sonar, subbottom profiler ed ecografo. mem. biogeogr. adriat., 9, suppl., 33-60. stefanon a. (1967) formazioni rocciose del bacino dell’alto adriatico. atti ist. ven. sc. lett. arti, 125, 79-85. stefanon a. (1979) gli affioramenti rocciosi dell’alto adriatico: considerazioni sulla loro distribuzione, struttura ed evoluzione, nel contesto della problematica del bacino. conv. pf oceanografia e fondi mar., roma, 1233-1242. stefanon a. (1984) sedimentologia del mare adriatico: rapporti tra erosione e sedimentazione olocenica. boll. ocean. teor. appl., ii, 4, 281-324. stefanon a. (1985) marine sedimentology through modern acoustical methods: i. side scan sonar. boll. ocean. teor. appl., iii, 1, 3-38. stefanon a. (1980) the acoustic response of some gas-charged sediments in the northern adriatic sea. bottom interacting ocean acoustics conference, saclant asw centre, la spezia, 73-84. stefanon a. & mozzi c. (1972) esistenza di rocce organogene nell’alto adriatico al largo di chioggia. atti ist. ven. sc. lett. arti, 130, 495499. stefanon a. & mozzi c. (1973) rock outcrops in the nortern adriatic sea. scien. div. inter, 203-206. stefanon a. & zuppi g.m. (2000) recent carbonate rock formation in the northern adriatic sea. hydrogèologie, 4, 3-10. 563i depositi cementati del ... ms. ricevuto l’8 giugno 2004 testo definitivo ricevuto il 23 novembre 2004 ms. received: june 8, 2004 final text received: november 23, 2004 available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 37 (1), 2024, 29-51 https://doi.org/10.26382/amq.2024.02 preserved and allow for more detailed stratigraphic reconstructions, which are meaningful to better understanding time-space relationship between glacial and proglacial environments (accorsi et al., 1990; monegato & ravazzi, 2018; palmer et al., 2019). the sensitivity of glaciolacustrine systems to icemass and landscape changes (carrivick & tweed, 2013) makes them valuable archives of glacier dynamics, particularly of deglaciation phases (i.e., shaw, 1975; orombelli & gnaccolini, 1978; colman et al., 1994; winsemann et al., 2009, 2018; nehyba et al., 2017; lang et al., 2018, 2021; kurjanski et al., 2021). here, proglacial lakes act as sedimentary sinks, in which the glacier discharges huge amounts of sediments, with important spatio-temporal variations in the flow regime (marren, 2005; fielding, 2006; duller et al., 2008; cuffey & paterson, 2010; carling, 2013; dowdeswell et al., 2015; fitzsimons & howarth, 2018; lang et al., 2021). they can be viewed as low-energy lakes receiving sediments from both glacial and fluvial-glaciofluvial input via a diversified range of steady to more episodic (e.g., slow fallout from the water column, density flows, supercritical flows) flows (church & gilbert, 1975; gustavson et al., 1975; bennet et al., 2002; palmer et al., 2019; lang et al., 2017, 2021). the prevailing depositional process is largely determined by climate-driven modifications of the glacier and landscape (bennett et al., 2002; fielding, 1. introduction understanding sedimentary processes of moraine systems is key to reconstruct past glacial dynamics. most of the best-studied moraine amphitheatres (also referred to as glacial amphitheatres) are relatively large examples formed after long sequences of glacial oscillations (ehlers & gibbard, 2004; ivy-ochs et al., 2018). moraine (or glacial) amphitheatres correspond to semicircular, concentric end-moraine systems, built up during the middle and upper pleistocene by glacier piedmont lobes flowing out of the major alpine valleys (fig. 1a; fairbrigde, 1968; cremaschi, 1987; bini & zuccoli, 2004). despite large glacial amphitheatres provide longterm sedimentary records that span multiple glacial and interglacial stages, the preservation potential of deposits and landforms, formed during each of these stages, is generally low (gibbons et al., 1984; cremaschi, 1987; bini & zuccoli, 2004; monegato et al., 2017). in fact, glacier front advances are generally able to destroy the most of previous stage deposits, making it difficult to infer processes from the sedimentary record, including those governing sedimentation in proglacial environments (jopling & mcdonald, 1975; ehlers & gibbard, 2004; carrivick & tweed, 2013). on the other hand, smaller moraine systems developed during the last glacial phases of the pleistocene are comparatively better last glacial maximum glaciolacustrine deposits from the adige moraine amphitheatre (rivoli veronese, northern italy): distribution, sedimentary facies, and significance andrea pezzotta 1 , guido s. mariani 2 , mattia marini 1 , mauro cremaschi 1 , andrea zerboni 1 dipartimento di scienze della terra “a. desio”, università degli studi di milano, milano, italy. dipartimento di scienze della terra, università degli studi di torino, torino, italy. corresponding author: andrea pezzotta <andrea.pezzotta@unimi.it> abstract: proglacial lakes formed between ridges, small fluvioglacial plains and glacier fronts of end-moraine systems are excellent sedimentary archives capable of accurately recording environmental variations linked to deglaciation. the adige moraine amphitheatre (ama) at the outlet of the adige valley in the southern foothill of the alps (rivoli veronese, verona; northern italy) is a multi-moraine ridges system built during the last glacial maximum (lgm) by two subsequent glacial advances of the adige glacier. within the innermost moraine arc of the ama, the topography of glacial deposits acted as a dam originating two separated proglacial lakes, collecting meltwaters. geomorphological and geological mapping allowed identifying the vestiges of a complex glaciolacustrine system with a branching proglacial lake in which deltaic and ice-contact situations coexisted. four sedimentary facies associations suggestive of ablating ice-front, glaciofluvial, deltaic, and glaciolacustrine depositional settings were recognised, and their spatial relationship clarified through facies analysis. results suggest the proglacial lake was likely enclosed by the glacier front, moraine ridges, and other glacial deposits that obstructed the pre-existent adige canyon, and that the two identified lake branches coalesced during the final phase of glacier retreat. the process controlling the draining of the lake is not completely known, but the occurrence of boulders (recurrently named as “erratics”) in the uppermost deposits of the adige river glaciofluvial fan to the south of ama suggests these may represent mega-clasts transported during the post-lgm collapse of the adige glacier. we propose that these mega-clasts were mobilized by a glacial lake outburst flood resulting from the collapse of the deposits obstructing the adige canyon upstream. our results add to better understanding of the ama deglaciation phases and to the reconstruction of the lgm-post-glacial transition period in the foothills of the southern central alpine region. keywords: proglacial lake, adige moraine amphitheatre, last glacial maximum, deglaciation, moraine amphitheatre. 2006; winsemann et al., 2009, 2018; palmer et al., 2019; lang et al., 2021), which typically results in strongly cyclical facies associations that may be used to reconstruct seasonal to secular limnological and glaciological changes (bersezio et al., 1999; pawlowsky et al., 2013; palmer et al., 2019). this contribution reports on glaciolacustrine deposits of the upper pleistocene adige moraine amphitheatre (ama), also known as the rivoli veronese moraine system (cremaschi, 1987), which was part of the greater adige-sarca glacial system of northern italy during most of pleistocene glaciations. the latter consists in the piedmont area by two sets of frontal-moraine systems characterized by a semi-circular amphitheatre-like shape, the garda and adige glacial amphitheatres (fig. 1 and 2; penck & brückner, 1909; venzo et al., 1969; bini & zuccoli, 2004; bini, 2012). located at the termination of the confined adige valley and at the foothills of the southern alps, the ama is one of the smallest yet best-preserved terminal moraine systems of continental europe (i.e., penck & brückner, 1909; venzo, 1961; cremaschi, 1987; bini, 2012). indeed, most of its recent construction, occurred during the last glacial maximum (lgm; accorsi et al., 1990), preserved it from 30 pezzotta a. et al >>>>> ------------------------------ >>>>>> fig. 1 (a) map of the alps illustrating the distribution of the maximum ice extent during middle-upper pleistocene, highlighting the main glacial amphitheatres of north italy (modified after ehlers & gibbard, 2004; margottini & vai, 2004; bini, 2012; ivy-ochs, 2015; ivy-ochs et al., 2018). countries’ borders from “world country” (porto tapiquén, 2015). (b) regional structural setting of the southern alps and po plain (hydrography and 20m resolution dem from ispra, 2012; redrawn after bigi et al., 1990; fantoni et al., 2004; scardia et al., 2014). (c) extension and age attribution of the moraine ridges formed during the pleistocene by the adige-sarca glacial system. with dotted lines the main meltwater pathways in the area comprised between the two amphitheatres (redrawn after venzo, 1957, 1961, 1965; venzo et al., 1969; cremaschi, 1987; accorsi et al., 1990; bini & zuccoli, 2004; monegato et al., 2017). marked by the red rectangle the ama (fig. 2). structural block gently tilted towards the po plain (fantoni et al., 2004; scardia et al., 2015). specifically, the lower adige valley is developed along the “giudicarie deformation system”, a nne-ssw trending polyphasic fault system (fig. 1b), connecting the lessini plateau to the deeper western lombardian basin (venzo et al., 1969; accorsi et al., 1990; fantoni et al., 2004; bassetti & borsato, 2005). the bedrock outcropping in the ama area belongs to the upper triassic upper eocene ‘so called’ venetian series and is composed by limestones, marly limestones, and marls of jurassic cretaceous age (venzo, 1961; venzo et al., 1969). the “giudicarie deformation system”, active since the mesozoic until the quaternary, coupled with differential subsidence, influenced the geomorphological evolution of the adige valley, resulting in an overexcavation of the lower part of the valley (venzo et al., 1969; sorbini et al., 1984; accorsi et al., 1990). many authors investigated the dynamics of the garda glacier, reconstructing multiple glacial advances from the early pleistocene up to the lgm two-fold glacial advance, which separated the garda and adige glaciers (fig. 1c) (i.e., nicolis, 1899; penck & brückner, 1909; cozzaglio, 1933, 1934a, 1934b, 1939; venzo,1957, 1961, 1965; habbe, 1960, 1969; mancini, 1960, 1969; fraenzle, 1965; venzo et al., 1969; cremaschi, 1987; cremaschi et al., 1987; accorsi et al., 1990; bini & zuccoli, 2004; ravazzi et al., 2014; monegato et al., 2017). specifically, the area has been intensively investigated since the 19th century (paglia, 1861; sacco, 1896; nicolis, 1899), leading to early recognition of the hills surrounding the garda lake as reworking and partial dismantling by further glacial advances as much as by post-glacial processes. because of subsequent phases of glacial retreat, terminal proglacial lakes formed in the innermost area of the ama (venzo, 1961; venzo et al., 1969; accorsi et al., 1990) and hosted glaciolacustrine sedimentation in a range of sub-environments (fig. 2 and 3). the resulting deposits are almost well-preserved, although the outcrops are usually not extensive, and provide a valuable record of lgm glaciolacustrine sedimentation which may help constraining dynamics and mechanics of the final retreat of the adige glacier. this work aims at providing constraints on the paleogeography of the latest lgm advance of the adige glacier and describing processes acting at the onset of the deglaciation. to accomplish this task, we mapped the spatial distribution of the sedimentary facies associations making up the proglacial deposits of the lgm adige glacier through the combined use of geomorphological and geological mapping and sedimentary facies analysis of type sections and key outcrops. 2. geological setting and previous works on the quaternary evolution of the garda and adige moraine amphitheatres from a geological point of view, the adige valley belongs to the southern alps domain, a fold-and-thrust belt formed during the alpine orogenic phase (laubscher, 1985; picotti et al., 1995; scardia et al., 2015). to the east, the garda and adige glacial amphitheatres are bounded by the lessini plateau (fig. 1b), a 31 lgm glaciolacustrine deposits from the adige moraine amphitheatre fig. 2 (a) interpretation for the relative age attribution of the glacial units of the ama; noting adige canyon is also known as chiuse d’adige canyon in the text (fig. 2b). the investigated area discussed in this paper is marked by the blue rectangle (fig. 3). (b) satellite image of the adige river glacial amphitheatre with topological references (google satellite, cnes/airbus, 2021). quaternary moraines (tab. 1). penck & brückner (1909) framed these into their four-stage (günz mindel riss würm) glaciation schema, which was later adopted with slight modifications by the detailed works of cozzaglio (1934a, 1934b, 1939) and venzo (1957, 1961, 1965). however, the chronostratigraphic attribution of these moraine ridges has been since long debated, highlighting the limitations of penck & brückner’s stratigraphic schema (cremaschi, 1987; bini & zuccoli, 2004). a synthesis of alternative hypotheses on stratigraphic attribution and significance of the glacial deposits in the garda glacial amphitheatre is reported in table 1. starting from the seminal work of penck & brückner (1909), both relatively younger and older glacial deposits have been consistently recognised in more internal (closer to the garda lake) and more external locations, respectively (fig. 1c). many scholars (tab. 1) follow a substantial homogeneity in stratigraphic classification, modifying the four-stage glaciation schema by revising it and adding or removing stages of minor advances (i.e., würm i, ii, iii; riss i, ii, etc.; cacciamali, 1914; cozzaglio, 1932; venzo, 1957, 1961, 1965; venzo et al., 1969). venzo (1957) recognized and separated the innermost moraine ridges based on their geological features quite different between them and from the rest of the amphitheatre but he was not able to move out the four-stage glacial schema (bini & zuccoli, 2004). cremaschi (1987) reconstructed the garda glacier history on correlations based on lithostratigraphy, magnetostratigraphy, paleopedostratigraphy and archeostratigraphy. he also further applied the correlations in a chronostratigraphic framework, recognizing 5 phases of glacial advance in the garda amphitheatre from the early pleistocene to the late pleistocene (tab. 1). furthermore, he hypothesized the subdivision of the last glacial advance into two substages, with the first corresponding to the main moraine ridge (cremaschi, 1987). bini & zuccoli (2004) and bini (2012) adopted the concept of allostratigraphic unit (richmond, 1962; bini 1997a) to reconstruct the chronology, evolution, and palaeogeography of the geological deposits. starting from the methodologies applied in the survey of the verbano and lario moraine amphitheatres (fig. 1a; bini, 1987; bini 1997b; bini et al., 2001; bini et al., 2014), 32 pezzotta a. et al fig. 3 quaternary geological sketch map of the ama innermost moraine ridge. the glacial units are summarized into three group, based on morphostratigraphic criteria: glacial advance 1, glacial advance 2, glacial retreat. furthermore, we reported also pre-glacial substrate (mesozoic limestones, venzo et al., 1969; accorsi et al., 1990) and post-glacial deposits. the outcrops and stratigraphic sections described in this paper are highlighted. smaller kame terraces are highlighted on the northern flank of mt la mesa by glaciofluvial deposits (gf3). cross sections are represented in fig. 5. cremaschi, 1987; monegato et al., 2007; gianotti et al., 2008, 2015; bini et al., 2014; ivy-ochs et al., 2018; monegato & ravazzi, 2018; rossato et al., 2018; braakhekke et al., 2020; kamleitner et al., 2022). monegato et al. (2017) identified fresh geomorphological, stratigraphical, and chronological evidence extending the validity of the model to the garda glacial amphitheatre (fig. 1c). it is therefore reasonable to attribute a similar lgm behaviour to its adige glacier companion (fig. 2 and 3). 2.1. focus on ama: geology, geomorphology and historical background the study area occupies an area of circa 6 km2 belonging to the innermost part of the ama system, which lies at the outlet of the adige valley and to the east of the garda glacial amphitheatre (fig. 1). yet, the smaller adige glacier impacted heavily on the surrounding landscape, occupying with its amphitheatre an area of more than 15 km2 (fig. 2). the elevation of the area is comprised between 87 and 460 m a.s.l., with an average of 218 m a.s.l. (fig. 2 and 3). the landscape is characterized by the presence of 7/8 semi-circular concentric moraine ridges, arranged in an “amphitheatre” shape, that border a series of glaciofluvial and glaciolacustrine plains/terraces, downscaling towards the current course of the adige river (fig. 4). figures 1c and 2a show the distribution of the ama moraine ridges: the outer part of the system includes two major moraine ridges; in the inner amphitheatre, ridges decrease in elevation towards the valley and become more discontinuous (fig. 3) (penck & brückner, 1909; venzo,1961; cremaschi, 1987; accorsi et al., 1990). furthermore, in the southern sector, the “chiuse d’adige” canyon is one of the main features (fig. 2): it is a small pathway bordered by very steep oolitic limestone walls characterized by notches on different levels and a meander geometry, developed due to the interaction of karst and fluvial prothey recognized up to 12 alloand lithostratigraphic units in the western portion of the garda glacial amphitheatre, leading to the individuation of 8 different glaciations (sensu richmond, 1986) from the lower pleistocene (mis 100-96) to the lgm (mis 2) (bini & zuccoli, 2004; bini, 2012). there is widespread consensus in literature that during the pleistocene glaciations, the garda and adige glaciers were part of the adige-sarca glacial system, a larger valley glacier bifurcating north of the city of trento. one larger tongue descended the sarca valley forming a piedmont glacier in correspondence to the presentday garda lake, while a smaller glacier developed along the adige valley (fig. 1a) (lenotti, 1980; cremaschi, 1987; bini, 2012; ravazzi et al., 2014). the extent and complexity of adige-sarca glacial system c. 15.000 km2 during the lgm, spanning a range of sedimentary, volcanic, magmatic, and metamorphic terranes explains the very varied lithological composition of its deposits. these include allochthonous clasts of rhyolites, porphyries, granitoids and meta-granitoids derived from the erosion of volcanic bodies in the eastern alps and from the alpine crystalline basement (baroni & cremaschi, 1987; bini & zuccoli, 2004; ravazzi et al., 2014). to the south, the garda and adige glaciers were probably confluent for most of the pleistocene glaciations, forming a single glacial amphitheatre (the prelgm garda glacial amphitheatre; bini & zuccoli, 2004). the two glaciers were in fact individual glacial bodies only during the last glacial advance, which terminated with separated end-moraine systems (garda and adige moraine amphitheatres; fig. 1) (cremaschi, 1987; bini, 2012). recently, several scholars reinvestigated many of the italian alpine pleistocene glacial amphitheatres and proposed a two-fold glacial advance model during the lgm at the southern alpine margin (bini, 1987; 33 lgm glaciolacustrine deposits from the adige moraine amphitheatre tab. 1 the different stratigraphical attributions of the glacial stages of the garda glacial amphitheatre. cesses. moreover, near caprino veronese, north of the ama, older till deposits are found which, due to the absence of absolute dating, can be doubtfully attributed to the early middle pleistocene (cozzaglio, 1933, 1934a; cremaschi, 1987; accorsi et al., 1990). in table 2 we report the correlations between different stratigraphies adopted in previous studies (nicolis, 1882; penck & brückner, 1909; cozzaglio, 1933, 1934a; habbe, 1960; venzo, 1961; venzo et al., 1969; cremaschi, 1987; accorsi et al., 1990; ravazzi et al., 2014). in the first work describing the area, the “carta geologica della provincia di verona” (“geological map of the verona province”; nicolis, 1882), the author recognized glacial deposits and moraines surrounding rivoli veronese town but was not able to separate different glaciations. penck & brückner (1909), in their seminal work on alpine glaciers, attributed the outermost moraine ridges to the riss glaciation, and the inner ones to the würm period. later works followed this concept with some modifications, moving the attribution of one or more moraine ridges to the würm or riss glaciations. cozzaglio (1933) hypothesised the existence of a mindel age moraine in the subsoil in front of the ama; furthermore, cozzaglio recognized muddy sediments in the inner würm moraine ridges and interpreted them as lacustrine-basinal sediments. habbe (1960) attributed all the amphitheatre to the riss glaciation based only on pedological analyses. in his comprehensive work on the quaternary geology of the garda and adige glacial amphitheatre, venzo (1961) suggested a two-fold glaciation model to explain the formation of the quaternary deposits of the ama, respectively to the riss and würm glacial expansions. to explain the presence of more than two major moraine ridges (fig. 2), venzo (1961) subdivided both glaciations into multiple phases of advance and retreat and attributed the outer moraine ridges to the riss glaciation and the inner system moraine ridges to the würm glaciation. he further divided the latter into three stages (würm i to würm iii), suggesting that the moraine system acted as a dam during the würm ii-würm iii interstage and triggered the formation of ice-marginal lakes at the mouth of the adige valley (venzo, 1961). however, in his following work (venzo et al., 1969), he simpli 34 pezzotta a. et al fig. 4 panoramic view from mt castello to the north (see fig. 2 for the location). on the landscape are highlighted the moraine ridge and glacial deposits (g and red lines), particularly in foreground and in background. in the middle a series of glaciolacustrine and glaciofluvial (gl) terraces are shown. tab. 2 the different stratigraphical attributions of the glacial stages of the ama. area is registered and related to the pedostratigraphical description of loess deposits (accorsi et al., 1990). ravazzi et al. (2014) attributed all ama moraine ridges to the lgm, without distinction of different advance phases, unlike the garda glacial amphitheatre (tab. 1 and 2). other information on the evolution of the ama come from studies involving the surrounding landscape. sorbini et al. (1984) surveyed the venetian plain south of verona and downstream the ama. they reported large boulders embedded in alluvial deposits cropping out in the venetian plain, characterized by dimensions up to 2 m in diameter and petrography coherent to the adige-sarca glacial system (sorbini et al., 1984). these features, combined with their position downstream circa 20 km south from the ama and 15 km east from the maximum glacial expansion of the adige-sarca glacial system, suggest that the boulders are related to the final stages of the adige glaciofluvial fan aggradation (sorbini et al., 1984). 3. methods mapping, data collection and interpretation proceeded through the following path: remote sensing infied his relative chronology and attributed the previous riss, würm i and würm ii to the riss glaciation, leaving the würm iii as the only deposits of the würm glaciation (tab. 2). such revisions come after the completion of the survey of both the garda and adige glacial amphitheatres (completed in 1965: venzo, 1965) and for reasons of scale. lenotti (1980) just gave some passing remarks to the discussion of the ama formation and referred to previous authors. more recent investigations, based on the abovementioned criteria for the classification of the garda glacial amphitheatre (cremaschi, 1987), permitted to attribute the outermost moraine ridge to the sedena stage (late middle pleistocene), and all the inner ones to the solferino stage (late pleistocene) (cremaschi, 1987). later, in accorsi et al. (1990) cremaschi made a review of the ama and reattributed the outermost moraine ridge to the m.te crivellino unit (middle pleistocene), the main moraine ridge to the m.te police unit (upper pleistocene) and the other ones to the fiffaro unit (upper pleistocene). in this framework, the presence of glaciolacustrine deposits is related to the glaciofluvial deposits of the late glacial paleochannel of the adige river (rivoli unit) (accorsi et al., 1990). the presence of occasional strips of older deposits in the ama 35 tab. 3 facies associations, facies types and codes. lgm glaciolacustrine deposits from the adige moraine amphitheatre vestigation, field survey with identification and descryption of key stratigraphic sections and outcrops, facies interpretation and morphostratigraphic correlations. for remote sensing investigations, we made combined use of 1:5.000 and 1:10.000 topographic maps and a digital elevation model (dem) with horizontal resolution of 5 m (regione veneto, 2018). all outcrops and stratigraphic sections (fig. 3 and s1) were mapped in wgs 84/utm zone 32n coordinate system using qgis (versions 3.4 and 3.16: qgis development team, 2019, 2021). each outcrop and stratigraphic section was associated to a code and georeferenced (material available through supplementary material fig. s1, tab. s1). the deposits were described by their properties (bini, 1990), including context, size and geometry of the outcrop, definition, grain size, texture, consolidation and cementation, clast morphology and petrographic composition, sedimentary structures, colours (with the munsell soil color charts code), and sedimentary facies defined following classical schemes (miall, 1977, 1978, 1996; eyles & miall, 1984; bini, 1990; bennet et al., 2002; johnsen & brennand, 2006; winsemann et al., 2009, 2018; bini et al., 2014; lang et al., 2017, 2021; lee, 2018; palmer et al., 2019; kurjanski et al., 2021). several sedimentary facies were identified (tab. 3), which were later grouped into four facies associations diagnostic of as many depositional settings (section 4.1), based on their spatial distribution, geomorphological meaning (section 4.2), occurrence in key outcrops and logged stratigraphic sections (section 4.3). the stratigraphic interpretation of the recognized units was extrapolated through the interpolation between dem, topography, and outcrops data (section 4.4), heading to a comprehensive morphostratigraphy of the ama innermost moraine ridge (fig. 3 and 5; gibbons et al., 1984; ivy-ochs et al., 2018). 4. results 4.1. facies associations this section reports the four different types of facies associations described in the study area, and details the distribution, properties, and significance of facies associations. 4.1.1. glacial diamictons (facies association g) this facies association consists of a variety of matrixand clast-supported gravelly diamictons forming moraine ridges, such those shown in the map of figure 3. the deposit is represented by generally poorly-sorted sediment admixtures (fig. 6a-b) with observed thicknesses up to 6 m highly variable textures (tab. 3). gravel-grade clasts represent the dominant volumetric fraction, accompanied with variable proportions of sand and mud. sands locally form discontinuous beds up to 0.6 m-thick with lateral continuity less than a few metres. internally, these deposits are massive, except for relatively better sorted lenses, which can show crossstratification and clast imbrication (fig. 6a-b; tab. 3). clasts are angular to well-rounded, with average size of 16 cm and max size of 150 cm. the matrix grain-size ranges from clay to coarse sand, with a colour varying from 7.5yr 7/2 (pinkish gray) to 10yr 6/3 (pale brown). the lithological composition of the coarse fraction is well -diversified (polygenic gravel), with abundant limestone clasts (60-70%), a moderate quantity of purple and green rhyolites-porphyries (20-30%), and less frequent basement lithologies (orthogneiss and quarzitic paragneiss, 10-20%). all clasts usually show very poor to poor weathering. occurrence and interpretation: the sedimentary character and geometry of these diamicton deposits suggest they can represent melt-out and, secondarily, 36 pezzotta a. et al fig. 5 the two stratigraphic cross sections of the ama innermost moraine ridge traced in fig. 3, showing the morphostratigraphy of the southern (a-b-c section, above) and northern (d-e-f section, below) sectors of the investigated area. vertical exaggeration is by two. colour varying from 7.5yr 6/4 (light brown) to 5yr 6/3 (light reddish brown) to 5yr 3/4 (dark reddish brown). the lithological composition of the coarse fraction is well -diversified (polygenic gravel), with abundant limestone clasts (50-70%), a moderate quantity of purple and green rhyolites-porphyries (20-30%), and less frequent basement lithologies (orthogneiss and quarzitic paragneiss, 10-20%). disregarding their composition, clasts show very poor to poor weathering. occurrence and interpretation: this facies association occurs in the uppermost terraced sitting on top of glacial diamictons of facies association g (section 4.1.1). sedimentary structures and depositional geometries are suggestive of deposition in a glaciofluvial setting at the glacier ice-front, in which fluvial processes and traction organise sediments in a range of fluvial bar types (jopling & mcdonald, 1975; bersezio et al., 1999; bennet et al., 2002; winsemann et al., 2018; lang et al., 2021; kurjanski et al., 2021). 4.1.3. deltaic deposits (facies association d) this facies association is composed of gravelly flow tills accumulated at the ablating ice-front. on the other hand, cross-stratified and better-sorted deposits are interpreted as the result of traction from stream waters able to rework sediments so as to form mediumscale bedforms (bini, 1990; winsemann et al., 2009; lee, 2018). 4.1.2. glaciofluvial deposits (facies association gf) this facies association is composed of clastsupported gravels and sandy gravels, forming rather monotonous sections up to at least 10 m (tab. 3). the stratification of these deposits lays horizontally. the finer -grained component of the deposits is represented by up to 40% of sand and c. 10% of silt. beds are erosionally based, with scours up to several tens of cm-deep or channelised (composite) basal surfaces. internally, the deposit can be structured, with throughand planar cross-stratifications and occasional clast imbrication (fig. 6c-d), and ungraded to crudely graded (fig. 7b). clasts are sub-angular to well rounded, with average size of 8 cm and max size of 50 cm. matrix grainsize is comprised between silt and coarse sand, with 37 lgm glaciolacustrine deposits from the adige moraine amphitheatre fig. 6 examples of facies from glacial diamictons, glaciofluvial and deltaic facies associations. (a) matrix-supported, stratified diamicton with evidence of current reworking, ascribed as flow till (northern flank of mt la mesa, id: 44). (b) matrix-supported, massive diamicton, ascribed as melt-out till (north of zuane, id: 127). (c) planar and through cross-stratified gravel (north-east of zuane di sotto exposure, id: 110). (d) clast-supported, imbricated gravel infilling a channel scour in matrix-supported massive diamicton (interpreted as till), highlighted by different grain sizes, clast-supported texture, and cementation (south-east of mt castello, id: 41). sands and relatively rarer clast-supported gravels forming bedsets up to c. 5 m-thick (tab. 3). the stratification of these deposits lay horizontally in all outcrops except from one locality (napoleonic monument exposure in section 4.3; fig. 7f), where it dips toward the nw with angles up to 20°. the finer-grained component of the deposits is represented by up to 40% of sand and c. 10% of silt. bed bases are flat to slightly erosional. internally, the deposit can be either massive (fig. 8a) or structured, with throughand planar cross-stratifications (fig. 7f, 9c-e) suggestive of migrating 2d and 3d dunes, and ungraded to normally graded (fig. 9f and 10d). notably, in the outcrop with inclined stratification these deposits are chiefly massive or normally graded, with little evidence of internal organisation, and interbedded with finer-grained glaciolacustrine deposits. here, some beds show evidence of soft sediment deformation, likely related to incipient gravity-driven slumping. the character of gravel-grade clasts is similar to that of facies association gf except for a relatively higher roundness and finer grain-size. occurrence and interpretation: this sedimentary facies association is exposed at different localities along the slopes facing the adige river (fig. 3) and are locally vertically and associated with glaciolacustrine deposits (facies association gl). massive to normally graded beds with inclined bedding and soft sediment deformations, such those cropping out at the napoleonic monument exposure (fig. 7f; section 4.3), can be interpreted as the product of deposition from a range of subaqueous sediment gravity flow types (including debris flows, hyperconcentrated turbidity currents and mass movements) in the relatively steep upper part of a delta front (bersezio et al., 1999; bennet et al., 2002; johnsen & brennand, 2006; winsemann et al., 2009, 2018; lee, 2018; kurjanski et al., 2021). on the other hand, structured deposits interbedded with glaciolacustrine deposits (e.g., in the rivoli section) resemble hyperpycnal bedload facies b1-b2 of zavala and pan (2018) and reported occurring on glaciolacustrine deltas by lang et al. (2017), and are thus better interpreted as the product of deposition from long-lived, flood-generated density flows in pro-delta settings (i.e., powell, 1990). 4.1.4. glaciolacustrine deposits (facies association gl) this facies association form a few to several mthick bedsets which locally sandwich (e.g., in the rivoli section, fig. 9) deltaic deposits (facies association d). it is represented by very thinto medium-bedded normally graded deposits including a range of sandy gravels to gravelly sands and very fine well-sorted sands, silts and clays (fig. 7c-f, 8b-d, 9b, e-g, and 10; tab. 3). gravels are generally erosionally-based and massive, with sparse out-sized mud clasts up to 5 cm. on the other hand, sands show flat bases and are internally characterised by throughand planar-cross stratification, 38 pezzotta a. et al fig. 7 outcrops from the northern investigated area. (a) global view of the zuane di sotto exposure. (b) normally graded pebbly gravel to granule and sand (deltaic facies association d), particular from the upper zuane di sotto exposure. (c) massive silt (glaciolacustrine facies association gl), particular of the lower zuane di sotto exposure. (d) “napoleonic monument” exposure, showing planarand crossstratified sand (glaciolacustrine facies association gl). (e) lowermost portion of the napoleonic monument exposure, composed by massive mud (glaciolacustrine facies association gl). (f) outcrop near napoleonic monument, composed by deltaic and glaciolacustrine facies associations; the dotted lines highlight the bedding, the solid lines highlight the boundaries between facies associations. notice the deformed stratification in the sandy deposits, interpreted as slumping. ted by flood-generated hyperpycnal flows (bennet et al., 2002; winsemann et al., 2009, 2018; lang et al., 2017; fitzsimons & howarth, 2018; palmer et al., 2019; sutherland et al., 2019; kurjanski et al., 2021). 4.2. geomorphology and spatial distribution of sedimentary facies associations from a morphological point of view, the study area is characterized by the presence of c. 15 (moraine) ridges, constituted by glacial diamictons of facies association g, at elevations in the range 170-215 m a.s.l. in the western flat area, and at elevations in the range 180 -305 m a.s.l. on the northern slopes of mt la mesa and mt pipalo (fig. 3). the northern slope of mt la mesa is also characterized by small (kame) terraces (at elevations of 215 and 240 m a.s.l.), infilled mainly by glaciofluvial deposits of facies association gf (fig. 3). in this setting, mt rocca, mt castello and the slope to the north of zuane di sotto exposure are constituted by mesozoic carbonates (fig. 3). the abovementioned western flat area (172-195 m a.s.l.) is composed of at least 10 m-thick glaciofluvial deposits (facies association gf), which are exposed along a quite continuous escarpment (northern escarpment, hereafter), extending from the zuane di sotto exposure to the north and the castello outcrop to the south. furthermore, these deposits surround the moraine ridges in the central and south-western portion of the area (fig. 3). to the south of rivoli veronese town, glaciolacustrine deposits cross-laminations (fig. 7d and 9d; tab. 3). very thinbedded alternations of sands, silts and clays result in heterolithic bedsets up to c. 1 m-thick, in which sands can form isolated sandy ripples (fig. 9b, 10c-f). gravel-grade clasts are sub-angular to well rounded, with average size of 0.5 cm and max size of 5 cm. the deposit colour varies from 10yr 6/4 (light yellowish brown), 7.5yr 8/4 (pink), to 5yr 6/3 (light reddish brown), to 2.5yr 6/3 (light reddish brown). the lithological composition of the gravel fraction is well-diversified (polygenic gravel), with presence of limestone, purple rhyolites-porphyries, and quartz; among the sand-grade, limestones and purple rhyolites-porphyries clasts, mica and quartz are recognizable. clasts are very poorly to poorly weathered. occurrence and interpretation: this facies association tends to form monotonous thin-bedded sections several m-thick and can be stratigraphically associated to deltaic deposits. the heterolithic structure of the deposits, in which beds with variable grain-sizes and sedimentary structures alternate, suggest deposition from numerous and discrete depositional events in a lowenergy glaciolacustrine setting occasionally reached by sediment gravity flows. silts and clays are the result of fall out deposition from suspension and may relate to homoand hypo-pycnal flood-generated flows, originating rhytmites. conversely, the thickest sand beds represent the product of en-masse and traction plus fall-out deposition from sediment gravity flows, most likely igni 39 lgm glaciolacustrine deposits from the adige moraine amphitheatre fig. 8 castello outcrop, northern sector. (a) global vision of the outcrop. gravel scours, characterized by clast-supported massive pebbly gravel (deltaic facies association d) are highlighted by an erosional surface above glaciolacustrine facies association gl. (b) particular showing normally graded sand (glaciolacustrine facies association gl); the dotted line highlights the inclined lamination. (c) ice-wedge cast within mud-prone deposit (glaciolacustrine facies association gl); the dotted line evidences the cast. (d) particular from fig. 8c, showing vertical and high-angle inclined lamination highlighted by dotted lines. 40 pezzotta a. et al f ig . 9 . r iv o li s e c ti o n w it h t h e ( a ) s tr a ti g ra p h ic l o g o f th e r iv o li s e c ti o n ( d ra w n w it h s e d lo g v .3 .1 , z e rv a s e t a l. , 2 0 0 9 ) a n d t h e m a in f a c ie s a s s o c ia ti o n s c o m p o s in g i t. t h e p o s it io n s o f th e fa c ie s r e p re s e n te d i n b -g a re d is p la y e d o n t h e l e ft o f th e s tr a ti g ra p h ic l o g . (b ) r h y tm it e s c o m p o s e d b y h o ri z o n ta lly l a m in a te d a lt e rn a ti n g s ilt , v e ry f in e s a n d a n d c la y ( g la c io la c u s tr in e f a c ie s a s s o c ia ti o n g l ) a t 1 7 .6 0 m . (c ) c e m e n te d s a n d , s a n d y g ra v e l a n d g ra v e l w it h p la n a r a n d t ro u g h c ro s s -s tr a ti fi c a ti o n ( d e lt a ic f a c ie s a s s o c ia ti o n d ) a t 1 3 -1 4 .5 0 m . (d ) p a rt ic u la r fr o m f ig . 9 c s h o w in g t h e t ra n s it io n f ro m t ro u g h c ro s s -s tr a ti fi e d g ra v e l, t o p la n a r a n d t ro u g h -c ro s s s tr a ti fi e d s a n d . (e ) p a rt ic u la r fr o m l o w e r f ig . 9 c h ig h lig h ti n g t h e p re s e n c e o f n u m e ro u s i n tr a c la s ts a t th e b a s e a n d w it h in p la n a r c ro s s -s tr a ti fi e d p e b b ly g ra v e l. ( f) s e q u e n c e o f c h a n n e l fi lls , c h a ra c te ri z e d b y n o rm a lly g ra d e d s a n d t o s ilt a n d g ra v e l to v e ry f in e s a n d o r s ilt ( g la c io la c u s tr in e (g l ) a n d d e lt a ic ( d ) fa c ie s a s s o c ia ti o n ) a t 1 -3 .5 0 m . (g ) p a rt ic u la r fr o m f ig . 8 f s h o w in g t h e c h a n n e liz e d s tr u c tu re s w it h g ra n u le s a n d p e b b le s a lo n g t h e b a s e o f th e c h a n n e l. v v v v v ------------------------------------------------------------------------------------------------------------------ v v v v v v f ig . 1 0 m t l a m e s a s e c ti o n w it h t h e ( a ) s tr a ti g ra p h ic l o g o f th e m t l a m e s a s e c ti o n ( d ra w n w it h s e d lo g v .3 .1 , z e rv a s e t a l. , 2 0 0 9 ) a n d t h e m a in f a c ie s a s s o c ia ti o n s c o m p o s in g i t. t h e p o s it io n s o f th e f a c ie s r e p re s e n te d i n b -g a re d is p la y e d o n t h e l e ft o f th e s tr a ti g ra p h ic l o g . (b ) g lo b a l v ie w o f th e s tr a ti g ra p h ic s e c ti o n . (c ) e ro s io n a l s u rf a c e s e p a ra ti n g r h y tm it e s c o m p o s e d o f s ilt , c la y a n d f in e a n d v e ry f in e s a n d ( g la c io la c u s tr in e f a c ie s a s s o c ia ti o n g l ) fr o m b e d s c o m p o s e d o f n o rm a lly g ra d e d s a n d t o m u d a n d n o rm a lly g ra d e d g ra v e l to s a n d ( g la c io la c u s tr in e fa c ie s a s s o c ia ti o n g l a n d h y p e rp y c n a l d e p o s it ) a t 5 .2 0 -6 .5 0 m . (d ) f in in g u p w a rd s t re n d c o m p o s e d a t th e b o tt o m b y c la s ts u p p o rt e d s a n d y g ra v e l w it h n o rm a l g ra d a ti o n a n d p la n a r c ro s s s tr a ti fi c a ti o n ( h y p e rp y c n a l d e p o s it s ), p a s s in g t o t h e t o p a t rh y ti m it e s o f fi n e s a n d , s ilt a n d c la y ( g la c io la c u s tr in e f a c ie s a s s o c ia ti o n g l ) a t 3 .9 0 .0 0 -5 .0 0 m . n o ti c e t h e i rr e g u la ri ty o f g ra v e l e ro s io n a l b a s e . (e ) e ro s io n a l b a s e o f th e s a n d y g ra v e l w it h e v id e n c e o f p la n a r a n d t ro u g h -c ro s s s tr a ti fi c a ti o n ( h y p e rp y c n a l d e p o s it s ) a b o v e f in e ly l a m in a te d /r h y tm it e s o f s a n d , c la y , a n d s ilt (g la c io la c u s tr in e f a c ie s a s s o c ia ti o n g l ) a t 3 .3 0 -4 .0 0 m . (f ) f in in g u p w a rd s t re n d c o m p o s e d a t th e b o tt o m b y m a s s iv e s a n d y g ra v e l (h y p e rp y c n a l d e p o s it s ), p a s s in g u p w a rd s t o w a rd s f in e ly la m in a te d s a n d , s ilt a n d c la y , n o rm a lly g ra d e d f in e s a n d , a n d f in e ly l a m in a te d m u d ( g la c io la c u s tr in e f a c ie s a s s o c ia ti o n g l ) a t 2 .6 0 -3 .4 0 m . (g ) n o ti c e t h e p e b b le ( m a rk e d b y t h e r e d c ir c le ) in s id e m a s s iv e s ilt y m e d iu m s a n d ( g la c io la c u s tr in e f a c ie s a s s o c ia ti o n g l ) a t 0 .4 0 m . 41 lgm glaciolacustrine deposits from the adige moraine amphitheatre (facies association gl) compose the flat area, adjacent to the lowermost moraine ridges of mt la mesa and to the west of a continuous escarpment (southern escarpment, hereafter), extending from the mt castello to the north to the mt rocca to the south (fig. 3). along the slopes connecting both the northern and southern escarpments to the present-day course of the adige river (96 m a.s.l.), glaciolacustrine deposits (facies association gl) outcrop. in the specific, the northern slope displays multiple terraces (with elevations varying within the range 128-155 m a.s.l.; fig. 4). these deposits show an up to 50 m-thick overall coarsening-upward trend in the upper part of the slope and are locally intercalated by erosionally-based, coarse-grained deltaic deposits (e.g., to the east of the napoleonic monument; fig. 3 and 5). at the bottom of the slope, c. 3 m of glacial diamictons of facies association g are exposed along the deeply incised creek to the south of the napoleonic monument (fig. 3). in the meanwhile, the southern slope shows a coarsening-upward trend with glaciolacustrine deposits and heteropic erosionally-based coarse-grained deltaic deposits. the deltaic facies association crops out to the south-west of mt rocca and more continuously from mt castello to the rivoli section (fig. 3). 4.3. key outcrops and type stratigraphic sections this section presents a comprehensive summary of observations made at five key-sites and typestratigraphic sections within the investigated area. these noteworthy outcrops are listed from north to south, contributing significantly to the realization of the cross-sections of fig. 5. 4.3.1. the zuane di sotto exposure this exposure (fig. 7a) is constituted by a series of relatively small outcrops straddling the northern escarpment in its north-eastern termination and located at elevations in range 170-178 m a.s.l. (fig. 3). proceeding from lower to higher elevations, glaciolacustrine, deltaic and glaciofluvial deposits crop out. glaciolacustrine and deltaic deposits (facies associations gl and d) are represented by interbedded heterolithic deposits and variously structured gravelly sands and sandy gravels, respectively (fig. 7c). the eastern escarpment exposes c. 2 m of the glaciofluvial gravels of facies association gf which demonstrably composes the topmost terrace (fig. 7b). the boundary between glaciolacustrine and the glaciofluvial deposits is not exposed. however, based on morphostratigraphic relationships and observations made along the northern escarpment, we may suggest heteropic transition and coarsening upwards trend from glaciolacustrine s.l. deposits (facies associations d and gl) towards glaciofluvial deposits of facies association gf (fig. 5). 4.3.2. the napoleonic monument exposure compared to the zuane di sotto, the napoleonic monument exposure is located in a more southern position (fig. 3 and 5) and at lower elevations (98-128 m a.s.l.). it consists of a series of scattered small outcrops in which from lower to higher elevations, a progression from thinly-bedded and generally fine-grained glaciolacustrine deposits (facies association gl; fig. 7d-e) to coarse-grained and generally less-organised deltaic deposits (facies association d) is observed. here, the bedding of deltaic deposits locally shows inclination angles as high as c. 20° associated with evidence of soft -sediment deformations, which suggest a relatively highgradient delta-front slope subject to gravitational deformation and slumping (fig. 7f). 4.3.3. the castello outcrop one of the key outcrops of the northern sector is located further to the south, c. 350 m to the northwest of mt castello and at an elevation of 170 m a.s.l. (fig. 3). the castello outcrop rests on top and to the north of a moraine ridge made of glacial diamictons belonging to facies association g (fig. 3). it is c. 10 m-long and exposes c. 1.5 m of deposits represented, from base to top, by glacial diamictons, trough cross-stratified sandy gravels resembling deposits of the deltaic facies association d, and heterolithic and thinly-bedded fine-grained deposits. the latter include finely laminated sand and mud, and massive mud (fig. 8a-b) characterized by vertical sub-millimetric to millimetric discontinuities highlighted by redoximorphic features (fig. 8c-d) and interpretable as ice wedge casts (cremaschi & van vlietlanoë, 1991; shur & zhestkova, 2003; mariani et al., 2015). 4.3.4. the rivoli section the rivoli stratigraphic section is exposed along the upper (between 169-189 m a.s.l.) part of a laterally extensive escarpment located immediately below the town of rivoli veronese (fig. 3). the section (fig. 9a) is c. 20.30 m-thick but partly covered and starts with thin to medium bedded alternations of muds and graded gravelly sands (facies association gl) suggestive of deposition in a proximal glaciolacustrine environment (fig. 9fg). above a partly exposed interval c. 7.5-thick, c. 5 m of planar-parallel and cross-stratified gravelly sands occur (fig. 9c-e) interpretable as hyperpycnal deposits accumulated in a pro-delta setting (facies association d). the section ends with a few metres of finely laminated alternations of clays, silts and very-fine sands (fig. 9b), most likely representing a relatively distal glaciolacustrine deposit. 4.3.5. the mt la mesa section this 6.90 m-thick section (fig. 10a) is exposed between 185-191 m a.s.l. along a road cut at the base of the northern slope of mt la mesa (fig. 3). the section is rather repetitive and overall finer-grained than the rivoli section. it is represented by an alternation of very thinbedded graded sands and muds with abundant plant fragments (fig. 10c-d). these are intercalated by rarer but thicker beds (thickness in the range 15-50 cm) of sands and sandy gravels locally rich in mud clasts (fig. 10c-g) and can be interpreted as sediments accumulating in a glaciolacustrine environment with occasional deposition from a range of sediment gravity flow types. 4.4. morphostratigraphic units based on sedimentary facies composition, spatial relationship between key sites, and geomorphological 42 pezzotta a. et al strate and on glacial advance 1 deposits (accorsi et al., 1990). this unit corresponds to previously attributed: würm i and würm ii gravel moraines (venzo, 1961); riss gravel moraines (venzo et al., 1969); diamicton from solferino moraine stage late pleistocene (cremaschi, 1987); moraine ridges related to the retreat of the adige-sarca glacial system from the fiffaro unit upper pleistocene (accorsi et al., 1990); glacial ridges of the lgm (ravazzi et al., 2014). 4.4.4. glacial retreat this unit consists of glaciofluvial gravels and sandy gravels (unit gf3), deltaic sandy gravels (unit d3), glaciolacustrine heterolitic deposits (unit gl3), and glacial diamicton (unit g3) (fig. 3). unit g3 glacial diamicton compose the tills of the moraine ridges surrounding zuane to the north and to the west, the ridges to the west of mt castello and rivoli veronese town, and the ones at the base of the northern flank of mt la mesa (fig. 3). unit g3 glacial diamicton are overlaid/ juxtaposed and partially eroded by units gf3, d3, and gl3 (glaciofluvial, deltaic and glaciolacustrine deposits). glaciolacustrine deposits (unit gl3) overlay unit g3 glacial diamicton, and are composed by sand, silt and clay representing a proglacial lake system (see section 4.1.4). unit gl3 outcrops along both northern (between the adige river, zuane and mt castello) and southern (between mt castello, rivoli veronese and mt la mesa) slopes. along the slopes, heteropic deltaic sandy gravels of unit d3 crops out near the napoleonic monument location, along the escarpment below the rivoli veronese town, and to the south-west of mt rocca. to the south, unit gf3 glaciofluvial gravels compose the infilling of small kame terraces (length is c. 150-180 m) along the northern flank of mt la mesa, and dominate the western portion of the investigated area as an outwash proglacial system, which erodes all the other deposits and units. this morphostratigraphic unit differs from the other glacial ones by its inner position, highlighted by the concentric and discontinuous moraine ridges. the upper boundary is the current topography and is characterized by a 50 cm thick 10yr to 7.5yr soil horizon, or sometimes by the erosional surface of the post-glacial unit. clasts are not weathered but some deposits are characterised by thin calcretes. the lower boundary with other units is an erosional surface. this unit corresponds to previously attributed: würm ii and würm iii gravel moraines, würm ii glaciofluvial coarse gravels and würm iii fluvio-lacustrine deposits (venzo, 1961); riss and würm gravel moraines, riss i and riss ii glaciofluvial gravels, würm-riss interglacial fluviolacustrine deposits (venzo et al., 1969); diamicton from solferino moraine stage late pleistocene (cremaschi, 1987); moraine ridges related to the retreat of the adige glacier (fiffaro unit upper pleistocene), kame terraces and glaciofluvial deposits related to the retreat of the adige glacier (zuane unit upper pleistocene), glaciolacustrine deposits of the rivoli veronese town and deposits of the late glacial paleochannel of the adige river (rivoli unit late glacial) (accorsi et al., 1990); glacial ridges of the lgm (ravazzi et al., 2014). features of the morphostratigraphic unit mapped in figure 3, this section addresses the stratigraphic architecture of the innermost moraine ridge of the ama. these units are coded with an acronym: the letters indicate the dominant facies association and the depositional setting (see section 4.1 “facies associations”), while the number denotes the glacial stage as reported in figures 2 and 3. 4.4.1. pre-glacial substrate the bedrock in the area is composed by nodular limestone, well-bedded marly limestone and oolitic limestone, reported as undistinguished mesozoic limestones (unit c) in figure 3. the substrate crops out to the north of the zuane di sotto exposure and on most of mt castello; to the south, limestones crop out to the north of mt pipalo and constitutes mt rocca (fig. 3). limestones are eroded and covered by most successive units. this bedrock is reported in literature by venzo (1961) as “cretaceous and pre-cretaceous series”, with references to cozzaglio (1934); venzo et al. (1969) attributed the sedimentary succession as bajocian-lower tithonian in age. 4.4.2. glacial advance 1 this unit consists of glacial diamicton (unit g1) (fig. 3). these deposits compose the tills of the moraine ridges in the mt pipalo area, at the southernmost point of the investigated area. compared to younger glacial units (see section 4.4.3 and section 4.4.4), ridges belonging to this unit are comparatively less continuous and more external (fig. 2 and 3). the upper boundary is the current topography and is characterized by a 50 cm thick 10yr to 7.5yr soil, or alternatively by an erosional surface from post-glacial, glacial retreat and glacial advance 2 units. the clasts are not weathered but most of its deposits are characterised by thin and discontinuous calcretes and caco3 nodules. the lower boundary is not exposed; however, based on morphostratigraphic interpretations we hypothesise an erosional surface above the pre-glacial substrate. this unit corresponds to previously attributed: würm i and riss gravel moraines (venzo, 1961); riss gravel moraines (venzo et al., 1969); diamicton from solferino moraine stage late pleistocene (cremaschi, 1987); moraine ridges of the greatest glacial expansion from m.te police unit upper pleistocene (accorsi et al., 1990); glacial ridges of the lgm (ravazzi et al., 2014). 4.4.3. glacial advance 2 this unit consists of glacial diamicton (unit g2) (fig. 3). these deposits compose the tills of the moraine ridges on the northern flank of mt la mesa and at its top, in the southern portion of the investigated area. this unit differs from the other glacial phases by higher and more continuous ridges, and sometimes doubling ridges (fig. 2 and 3). the upper boundary is the current topography and is characterized by a 50 cm thick 10yr to 7.5yr soil, or alternatively by an erosional surface from postglacial and glacial retreat units. the clasts are not weathered but most of its deposits are characterised by thin calcretes and caco3 coatings on clasts. the lower boundary is an erosional surface on the pre-glacial sub 43 lgm glaciolacustrine deposits from the adige moraine amphitheatre 44 pezzotta a. et al fig. 11 proposed reconstruction model of the ice-contact proglacial lake of the innermost moraine ridge of the ama. (a) last advance stadial phase with moraine ridge build-up and meltwater streams passing through the moraine ridges. (b) onset of the proglacial lakes. here the lake is split by the bedrock of mt. castello. (c) coalescence of the two lakes due to the progressive glacial retreat. (d) final glof of the proglacial lake generated by the breakthrough in the sedimentary plug. glaciolacustrine sedimentation. whereas along the southern slope, comprised between mt castello to the north and mt la mesa to the south, glaciolacustrine sediments show a coarsening upwards trend, with alternating mud-prone and sandy deposits heteropic to deltaic facies association. in this context, the presence of coarser-grained deposits in the rivoli section can attest to a proximal/deltaic setting respect to the finer-grained sediments of the mt la mesa section, which can testify distal glaciolacustrine environment. studied sections and facies associations show that proglacial lakes included delta systems, transitioning laterally to direct contact of the ablating ice-front to the proglacial lake (fig. 11). in this context, the glaciolacustrine setting is characterized by shifting from deltaic system to proximal and distal glaciolacustrine depositional environments. delta systems show great mobility in their sedimentary distributary pattern, with erosionally -based gravelly deltaic heteropic to sandy and mudprone glaciolacustrine deposits. this reflects how the proglacial lake depositional style is dominated by a series of gravity flows driven processes, such as debris flows, hyperconcentrated and concentrated density flows, highand low-density turbidity currents, slumping, up to fall out settling, but also related to fluvial processes with tractive currents and hyperpycnal flows (i.e., bersezio et al., 1999; bennet et al., 2002; winsemann et al., 2009; lang et al., 2017, 2021; palmer et al., 2019). these depositional processes may have an episodic to quasi-steady nature led by different trigger mechanisms, from remobilisation of sediments to sustained flows of turbidity currents originated by meltwater and deltaic input, to currents generated by more or less continuous river floods (i.e., hyperpycnite). erosional activity is recorded by scours, intraclasts, and gravelly erosional bases (bennet et al., 2000, 2002); although they may correspond to water level fluctuations, no basin-wide unconformity was recognised. in this setting, the potential water depths is not very high with maximum water depth circa 25-50 m. the infilling of the basin is also a matter of discussion, since there is no incontestable evidence of a single cycle of basin-fill before the final lake drainage happened during glacial retreat. while we do not exclude a priori the possibility of multiple cycles of basin-fill, the absence of recognizable lakewide unconformities suggests a single cycle model (i.e., bennet et al., 2002). the rapid variations of the depositional environments can be related to different factors, such as the available accommodation space, the fluctuations of the glacier front, the sedimentary input pathways (delta vs ice-front), and the quantity of water vs sediments discharge (i.e., bennet et al., 2000, 2002; winsemann et al., 2018; palmer et al., 2019). all these factors can change between the northern and southern branches, which show great affinity but also some divergences. among them, the different stacking of facies associations suggests the plausible development of two separated lacustrine branches during part or all of the final stage of glacial retreat, possibly coalesced together (fig. 11b-c). frost action, recorded by the occasional presence of ice-wedge casts formed into glaciolacustrine sediments (fig. 8), was also effective during the 4.4.5. post-glacial this unit consists of alluvial deposits (unit a) and slope deposits (unit s) (fig. 3). unit a deposits are composed of silt, sand and gravel, which presence is limited to the banks and terraces on the current course of the adige river. unit s deposits are formed by colluvium and slope debris and derive from the dismantling of previous glacial, glaciofluvial and substrate deposits. the lower boundary with other units is always an erosional surface. the upper boundary is the current topography and is characterized either by the absence of soil cover or by a 10yr to 5yr soil up to 50 cm thick. 5. discussion: basin-fill architecture and evolution of the ama innermost moraine ridge morphostratigraphic investigations show different types of facies associations occurring in the study area that can be attributed to different units of late pleistocene (glacial, glaciofluvial, glaciolacustrine) and holocene (related to fluvial or pediment systems) deposits (fig. 3). furthermore, field survey indicates that two different glacial advances occurred in the area, followed by a glacial retreat. notably, these phases are marked by tills forming moraine ridges and double ridges. this context implies a complex glacial history occurred in the lgm and pedogenesis affecting deposits only during the holocene (accorsi et al., 1990). the age attributions are based on morphostratigraphic markers and correlations made according to literature (cremaschi, 1987; accorsi et al., 1990; bini & zuccoli, 2004; bini, 2012; monegato et al., 2017) due to the lack of absolute dating. once the adige glacier retreated behind the innermost moraine ridges (fig. 11a), meltwater infilled the depression, also thanks to the low permeability of the underlying tills (anderson, 1989; bersezio et al., 1999; fig. 11b). two different interpretative models can explain such setting: 1) a kame terracing sequence, with a series of younger downscaling terraces during glacial retreat; 2) the infilling of the ama innermost moraine ridge by one or more proglacial lake systems. we propose the glaciolacustrine hypothesis. the morphostratigraphic approach suggests that such proglacial lakes were a continuum between an ice-contact proglacial lake and a glaciolacustrine delta system (fig. 11b-c); furthermore, the proglacial lakes were dammed by moraine ridges and other glacial deposits, as well as by the glacier itself. such barriers also occluded the pre-existing adige canyon, thus constraining the meltwater drainage pathways of the adige glacier to move west, cutting down the moraine ridges during both glacial advances and retreat (fig. 1, 2 and 11). along the innermost moraine ridges of the ama, the glaciolacustrine succession is almost continuous, occasionally interrupted by deltaic sandy gravels. these intercalations may be related to more continuous and sustained hyperpycnal flows or to aggradation and backstepping of delta systems. the northern slope, comprised between zuane di sotto exposure to the north and mt castello outcrop to the south, shows a general coarsening-upward trend from mud-prone to sandy deposits, suggesting a transition from distal to proximal 45 lgm glaciolacustrine deposits from the adige moraine amphitheatre glacial retreat phase at the end of lgm as well as during previous periods (cremaschi & van vliet-lanoë, 1991; mariani et al., 2015). these casts show the occurrence of freeze-thaw cycles at the surface of the deposits and mark clear evidence of seasonal permafrost formation in a periglacial environment after the desiccation of proglacial lakes. the presence of redoximorphic features inside the casts can indicate successive water saturation processes possibly related to a warmer climate phase (i.e., cremaschi, 1990; cremaschi & van vliet-lanoë, 1991; shur & zhestkova, 2003; mariani et al., 2015). in the final retreat of the adige glacier the proglacial lake disappeared (fig. 11d). this can possibly relate to the reopening of the adige canyon. in fact, we postulate that the canyon was already incised before the lgm, considering the tectonic, seismic activity, and subsidence movements that characterized both the venetian plain and lower adige valley since the pliocene up to the middle pleistocene, and still seismically active in historical times (sorbini et al., 1984; scardia et al., 2015; martin et al., 2020). the adige canyon (fig. 2) is a small passageway bordered by very steep limestone walls and a meander geometry: the formation of such incision must have required an erosional work much longer than the post-deglaciation time-window. since the canyon threshold is significantly lower than the ama level, meltwater would have preferentially passed in it instead of eroding the ama moraine ridges, making it implausible to forming proglacial lake inside the ama and meltwater pathways between the two moraine amphitheatres. the obstruction of the canyon is confirmed by the presence of notches (inland karst notches, shtober-zisu et al., 2015) on the walls in the passageway and of glacigenic sediments on both sides of the canyon. furthermore, another portion of the adige river path is incised in the bedrock between parona and verona (fig. 1; dal piaz et al., 1968; venzo et al., 1969; sorbini et al., 1984). furthermore, the canyon obstruction is corroborated by the morphology of the ama, which shows how the lgm meltwater pathways from the adige glacier flowed towards the west, cutting moraine ridges and bending south in the lowlands between the garda and adige glacial amphitheatres (fig. 1 and 11; venzo, 1961; venzo et al., 1969; cremaschi, 1987). this condition would have lasted until the final recessional phase, when the adige river finally managed to break the sedimentary plug and started to flow through the canyon, as is the current river setting (fig. 11d). the presence of glacial deposits filling most of the canyon is supported by the occurrence of boulders in the lgm adige glaciofluvial fan sedimentary succession near the city of verona, c. 20 km south the ama and 15 km east the maximum glacial expansion of the adigesarca glacier (cozzaglio, 1933; sorbini et al., 1984). in fact, during the lgm glacial tongues did not reach the area of verona, making the occurrence of these megaclasts (named in literature “erratics” or “glacial erratics”) only possible through transportation by high-concentrated floods. considering these points, we propose that the opening of the adige canyon was a sudden, dramatic event, likely a glacial lake outburst flood (glof; fig. 11d). the glof could have been triggered by a landslide of glacial sediments and/or ice in the icecontact lake or by a huge and rapid high-density meltwater discharge from the proglacial lake. glofs have been reported from numerous locations in other sectors of the venetian and friulan plain (northern italy) and they are also common in other glaciated areas of the world (i.e., desio & orombelli, 1983; hewitt, 2009; monegato et al., 2020; panin et al., 2020; emmer, 2023). in such perspective, the sedimentary process in charge of the placement of the ‘verona erratics’ is more similar to the one proposed by desio & orombelli (1983) to interpret the origin of the ‘punjab erratics’. furthermore, the drainage of the proglacial lake generated a fluvial erosional surface, composed by erosional river terraces and channel (i.e., bennet et al., 2000, 2002; panin et al., 2020). 6. conclusions the mapping and sedimentary facies analysis of the innermost moraine ridge of the ama gives a complex insight on the adige glacier evolution during the lgm and the critical phase of the last deglaciation, regionally dated between 24 and 17 ka (fontana et al., 2014; ravazzi et al., 2014; wirsig et al., 2016; monegato et al., 2017; braakhekke et al., 2020). in our study we could assess that:  the main and outermost moraine ridges of the ama were built during at least two glacial advances, while the inner ones during a glacial retreat. in the absence of absolute ages, morphostratigraphy suggests that these advances can be correlated to lgm multi-fold advances (i.e., monegato & ravazzi, 2018).  landscape evidence, morphostratigraphy and depositional architecture from the sedimentary facies associations of the ama innermost moraine ridge indicate that this area was occupied by a two branching proglacial lake, dammed by moraine ridges and glacial deposits as well as by the glacial front.  the basin-fill of the proglacial lakes shows that this setting can be interpreted as a continuum between an ice-contact proglacial lake and a glaciolacustrine delta system, with many vertically and laterally shifts of facies associations.  the reconstruction of the drainage of the proglacial lakes leads to a glof hypothesis related to the reopening of the adige canyon. this is supported by the presence of boulders (“erratics”) along the lgm adige glaciofluvial fans (cozzaglio, 1933; sorbini et al., 1984) and by the formation of a fluvial erosional surface in the innermost moraine ridge of the ama. this model is in accordance with similar dynamics from other southern alpine contexts (i.e., fontana et al., 2014; monegato et al., 2020) and adds a key piece in the transition from the lgm to the deglaciation in the region. acknowledgment the authors wish to thank two anonymous reviewer who greatly ameliorate the quality of the original manuscript. additionally, the authors extend their appreciation to the editor in chief dr. i.mazzini and associate 46 pezzotta a. et al switzerland). southern alps quaternary geology, igcp 378 meeting, lugano oct 1995. geologia insubrica, 2 (2), 21 46. bini a. (2012) i ghiacciai del passato. in: bonardi l., rovelli e., scotti r., toffaletti a., urso m., villa f., (eds.), i ghiacciai di lombardia. evoluzione e attualità, 10-19. bini a., zuccoli l. (2004) prime note sul rilevamento dell’anfiteatro del garda: metodi e unità provvisorie. il quaternario, 17, 333-342. bini a., felber m., pomicino n. e zuccoli l. (2001) geologia del mendrisiotto (canton ticino, svizzera): messiniano, pliocene e quaternario. berichte des bundesamt für wasser und geologie. rapporti dell'ufficio federale delle acque e della geologia bwg/ufaeg, 1, pp. 459. bini a., bussolini c., turri s., zuccoli l. (2014) carta geologica alla scala 1:100.000 dell’anfiteatro morenico del verbano. sibrium, xxviii, 24 81. braakhekke j., ivy-ochs s., monegato g., gianotti f., martin s., casale s., christl m. (2020) timing and flow pattern of the orta glacier (european alps) during the last glacial maximum. boreas, 49, 315-332, doi: 10.1111/bor.12427 cacciamali g.b. (1914) appunti sull’anfiteatro morenico benacese. rend. r. ist. lomb. sc. lett., 47 (9), 431-450. carling p.a. (2013) freshwater megaflood sedimentation: what can we learn about generic processes? earth-sci. rev., 125, 87-113. carrivick j.l., tweed f.s. (2013) proglacial lakes: character, behaviour and geological importance. quaternary science reviews, 78, 34-52. church m., gilbert r. (1975) proglacial fluvial and lacustrine environments. in: jopling a.v., mcdonald b.c. (eds.), fluvioglacial and glaciolacustrine sedimentation. society of economic paleontologists and mineralogist, special publication, 23, 22100. cnes/airbus (2021) european space imaging [basemap]. world imagery. last accessed october, 09, 2022, from https://earth.google.com. colman s.m., clark j.a., clayton l., hansel a.k., larsen c.e. (1994) deglaciation, lake levels, and meltwater discharge in the lake michigan basin. quatern. sci. rev., 13, 879-890. cozzaglio a. (1932) le formazioni glaciali del lago di garda. memorie dell’ateneo di salò, 2, 7-14. cozzaglio a. (1933) note illustrative della carta geologica delle tre venezie. fogli peschiera e mantova. ufficio idrografico r. magistrato delle acque, sezione geologica, padova. cozzaglio a. (1934a) carta geologica delle tre venezie. foglio peschiera. ufficio idrografico r. magistrato delle acque, sezione geologica, padova. cozzaglio a. (1934b) carta geologica delle tre venezie. foglio mantovaufficio idrografico r. magistrato delle acque, sezione geologica, padova. cozzaglio a. (1939) carta geologica d'italia. foglio brescia ufficio geologico, roma. cremaschi m. (1987) paleosols and vetusols in the editor dr. g. scardia for their supervising during the submission process of this article. we wish to thank dr. p. bellotti, for helping during field works, and dr. a. perego, for contributing to the drawing of fig. 1a. funding for fieldwork was provided by the università degli studi di milano (progetto linea 2, 2017) and project cte_nazpr19azerb_01 entrusted to a. zerboni. references accorsi c.a., aitken m.j., cremaschi m., ferraris m., mcelroy c., questiaux d., van vliet-lanoë b. (1990) the loess deposits of the rivoli moraine system. in: cremaschi m. (ed.), the loess in northern and central italy: a loess basin between the alps and the mediterranean region. c.n.r., centro di studio per la stratigrafia e petrografia delle alpi centrale, milano, italy, 21-39. anderson m.p. (1989) hydrogeologic facies models to delineate large-scale spatial trends in glacial and fluvioglacial sediments. geological society of america bulletin, 101, 501-511. baroni c., cremaschi m. (1987) geologia e pedostratigrafia della collina di ciliverghe (brescia). natura bresciana, 23, 55-78. bassetti m., borsato a. (2005) evoluzione geomorfologica della bassa valle dell’adige dall’ultimo massimo glaciale: sintesi delle conoscenze e riferimenti ad aree limitrofe. studi trentini di scienze naturali, acta geologica, 82, 31-42. bennet m.r., huddart d., mccormick t. (2000) an integrated approach to the study of glaciolacustrine landforms and sediments: a case study from hagavatn, iceland. quaternary science reviews,19, 633-665. bennett m.r., huddart d., thomas g.s.p. (2002) facies architecture within a regional glaciolacustrine basin: copper river, alaska. quaternary science reviews, 21, 2237-2279. bersezio r., bini a., giudici m. (1999) effects of sedimentary heterogeneity on groundwater flow in a quaternary pro-glacial delta environment: joining facies analysis and numerical modelling. sedimentary geology, 129, 327-344. bigi g., castellarin a., coli m., dal piaz g.v., sartori r., scandone p., vai g.b. (1990) structural model of italy scale 1:500.000, sheet 1. c.n.r., progetto finalizzato geodinamica, selca firenze. bini a. (1987) l’apparato glaciale würmiano di como. tesi di dottorato di ricerca, dipartimento di scienze della terra, università degli studi di milano. bini a. (1990) dispense di geologia del quaternario 1 descrizione di affioramenti e sezioni stratigra-fiche. ghedini editore, milano, pp. 180. bini a. (1997a) problems and methodologies in the study of the quaternary deposits of the southern side of the alps. southern alps quaternary geology, igcp 378 meeting, lugano oct 1995. geologia insubrica, 2 (2), 1120. bini a. (1997b) stratigraphy, chronology and palaeogeography of quaternary deposits of the area between the ticino and olona rivers (italy 47 lgm glaciolacustrine deposits from the adige moraine amphitheatre central po plain (northern italy). edizioni unicopli, milano, pp. 306. cremaschi m. (1990) the loess in northern and central italy: a loess basin between the alps and the mediterranean region, cremaschi m. (ed.), quaderni di geodinamica alpina e quaternaria, milano, pp. 187. cremaschi m., van vliet-lanoë b. (1991) traces of frost activity and ice segregation in pleistocene loess deposits and till of northern italy: deep seasonal freezing or permafrost. quaternary international, 5, 115-124. cremaschi m., alessio m., allegri l., azzi c., calderoni g., cortesi c., petrone v., spezzi bottani c. (1987) una data radiocarbonica del paleosuolo su loess incluso nella successione stratigrafica della val sorda (sistema morenico del garda). rend. soc. geol. it., 10, 29-32. cuffey k.m.. paterson w.s.b. (2010) the physics of glaciers. elsevier, amsterdam, pp. 693. dal piaz g.b., dal cin r., de vecchi g.p., monese a., sassi f., bianchi a., zanettin b., corsi m., gatto g., gatto g.o., piccoli g., rui a., bosellini a., leonardi p., malaroda r. (1968) carta geologica d’italia foglio 49 ‘verona’. italian geological survey, rome, 1:100.000 scale geological map. desio a., orombelli g. (1983) the "punjab erratics" and the maximum extent of the glaciers in the middle indus valley (pakistan) during the pleistocene. atti della accademia nazionale dei lincei, scienze matematiche, fisiche e naturali, 17 (3), pp. 30. dowdeswell j.a., hogan k.a., arnold n.s., mugford r.i., wells m., hirst j.p.p., decalf c. (2015) sedimentrich meltwater plumes and ice-proximal fans at the margins of modern and ancient tidewater glaciers: observations and modelling. sedimentology, 62, 1665-1692. duller r.a., mountney n.p., russell a.j., cassidy n.c. (2008) architectural analysis of a volcaniclastic jökulhlaup deposit, southern iceland: sedimentary evidence for supercritical flow. sedimentology, 55, 939-964. ehlers j., gibbard p. (2004) quaternary glaciations extent and chronology. part i: europe. developments in quaternary science series volume 2, elsevier, amsterdam, pp. 475. emmer a. (2023) vanishing evidence? on the longevity of geomorphic glof diagnostic features in the tropical andes. geomorphology, 422, 108552, issn 0169-555x. doi: 10.1016/j.geomorph.2022.108552 eyles n., miall a.d. (1984) glacial facies. in: walker r.g. (ed.), facies models. geoscience canada reprint series, 1, 15-38. fairbridge r.w. (1968) encyclopedia of geomorphology. dowden, hutchinson & ross inc. fantoni r., bersezio r., forcella f. (2004) alpine structure and deformation chronology at the southern alps-po plain border in lombardy. bollettino della società geologica italiana, 123, 463476. fielding c.r. (2006) upper flow regime sheets, lenses and scour fills: extending the range of architectural elements for fluvial sediment bodies. sed. geol., 190, 227-240. fitzsimons s., howarth j. (2018) chapter 9 glaciolacustrine processes. in: menzies j., van der meer j.j.m. (eds.), past glacial environments, second edition. elsevier, 309-334. fontana a., monegato g., zavagno e., devoto s., burla i., cucchi f. (2014) evolution of an alpine fluvioglacial system at the lgm decay: the cormor megafan (ne italy). geomorphology, 204, 136-153. fraenzle o. (1965) die pleistozaene klima und landschaftsentwicklung der nordlichen po ebene im lichte bodengeographischer untersuchungen. akad. wiss. lit. abb. mat. nat. kl., 8, 336-456. gianotti f., forno m.g., ivy-ochs s., kubik p.w. (2008) new chronological and stratigraphical data on the ivrea amphitheatre (piedmont, nw italy). quaternary international, 190, 123-135. gianotti f., forno m.g., ivy-ochs s., monegato g., pini r., ravazzi c. (2015) stratigraphy of the ivrea morainic amphitheatre (nw italy): an updated synthesis. alpine and mediterranean quaternary, 28, 29-58. gibbons a.b., megeath j.d., pierce k.l. (1984) probability of moraine survival in a succession of glacialadvances. geology, 12, 327-330. gustavson t.c., ashley g.m., boothroyd j.c. (1975) depositional sequences in glaciolacustrine deltas. in: jopling a.v., mcdonald b.c. (eds.), fluvioglacial and glaciolacustrine sedimentation. society of economic paleontologists and mineralogist, special publication, 23, 264-280. habbe k.a. (1960) zur klimatischen morphologie des alpensudrands. untersuchungen in den moranenamphitheatern der etsch und des gardasces. nachrichten d. akad. d. wissenschaft in gottingen, 10, 179-203. habbe k.a. (1969) die würmzeitliche vergletscherung des gardasee. gebietes freiburger geographische arbeiten, 3. hewitt k. (2009) catastrophic rock slope failures and late quaternary developments in the nanga parbat -haramosh massif, upper indus basin, northern pakistan. quaternary science reviews, 28, 10551069. ispra (2012) rete del sistema informativo nazionale ambientale. dem20. retrieved from http:// www.sinanet.isprambiente.it/it/sia-ispra/downloadmais/dem20/view. ivy-ochs s. (2015) glacier variations in the european alps at the end of the last glaciation. cuadernos de investigación geográfica, 41, 295-315. ivy-ochs s., lucchesi s., baggio p., fioraso g., gianotti f., monegato g., graf a., akçar n., christl m., carraro f., forno m.g., schlüchter c. (2018) new geomorphological and chronological constraints for glacial deposits in the rivoli-avigliana end-moraine system and the lower susa valley (western alps, nw italy). journal of quaternary science, 33(5), 550-562. doi: 10.1002/jqs.3034 johnsen t.f., brennand t.a. (2006) the environment 48 pezzotta a. et al rothschild seminar on atmospheric dust, dust deposits (loess) and soils in deserts and the desert fringe 2015. marren p.m. (2005) magnitude and frequency in proglacial rivers: a geomorphological and sedimentological perspective. earth-sci. rev., 70, 203-251. martin s., ivy-ochs s., viganò a., campedel p., rigo m., vockenhuber c., gabrieli f., mair v., rossato s. (2020) landslides of the western dolomites: case studies from the adige and sarca valleys (ne italy). alpine and mediterranean quaternary, 33(2), 191-207. doi: 10.26382/amq.2020.15 miall a.d. (1977) a review of the braided river depositional environment. earth science reviews 13, 162. miall a.d. (1978) fluvial sedimentology. canadian society of petroleum geologists, 5. miall a.d. (1996) the geology of fluvial deposits. springer verlag, berlin. monegato g., ravazzi c. (2018) the late pleistocene multifold glaciation in the alps: updates and open question. alpine and mediterranean quaternary, 31 (quaternary: past, present, future aiqua conference, florence, 13-14/06/2018), 225-229. doi: 10.26382/aiqua.2018.aiquaconference monegato g., ravazzi c., donegana m., pini r., calderoni g., wick l. (2007) evidence of a two-fold glacial advance during the last glacial maximum in the tagliamento end moraine system (eastern alps). quaternary research, 68(2), 284-302. doi: 10.1016/j.yqres.2007.07.002 monegato g., scardia g., hajdas i., rizzini f., piccin a. (2017) the alpine lgm in the boreal ice-sheets game. scientific reports, 7, 2078. doi: 10.1038/s41598-017-02148-7 monegato g., mozzi p., paiero g., rossato s. (2020) sedimentary evidence of glacial lake outburst floods (glofs) during the last glacial maximum in the venetian-friulian plain (ne italy). quaternary international, 538, 44-52. doi: 10.1016/j.quaint.2018.04.042 nehyba s., hanáček m., engel z., stachoň z. (2017) rise and fall of a small ice-dammed lake-role of deglaciation processes and morphology. geomorphology, 295, 662-679. nicolis e. (1882) carta geologica della provincia di verona. memorie dell’accademia d’agricoltura arti e commercio di verona. nicolis e. (1899) triplice estensione glaciale ad oriente del lago di garda. ibid, tomo lviii, venezia. orombelli g., gnaccolini m. (1978) sedimentation in proglacial lakes: a würmian example from the italian alps. zeitschrift fur geomorphologie, 22(4), 417-425. paglia e. (1861) sulle colline di terreno erratico intorno all’estremità meridionale del lago di garda. atti soc. it. sc. nat., 2, 337-342. palmer a.p, bendle j.m., macleod a., rose j., throndycraft v.r. (2019) the micromorphology of glaciolacustrine varve sediments and their use for reconstructing palaeoglaciological and palaeoenvironmental change. quaternary science rein and around ice-dammed lakes in the moderately high relief setting of the southern canadian cordillera. boreas, 35, 106-125, oslo, issn0300-9483. doi: 10.1080/03009480500359145 jopling a.v., mcdonald b.c. (1975) fluvioglacial and glaciolacustrine sedimentation. society of economic paleontologists and mineralogist, special publication, 23, pp. 325. kamleitner s., ivy-ochs s., monegato g., gianotti f., akçar n., vockenhuber c., christl m., synal, h.a. (2022) the ticino-toce glacier system (swissitalian alps) in the framework of the alpine last glacial maximum. quaternary science reviews, 279, 107400. kurjański b., rea b.r., spagnolo m., cornwell d.g., howell j., comte j.c., gonzález quirós a., palmu j.-p., oien r.p., gibbard p.l. (2021) cool deltas: sedimentological, geomorphological and geophysical characterization of ice-contact deltas and implications for their reservoir properties (salpausselkä, finland). sedimentology, 68, 3057-3101. doi: 10.1111/sed.12884 lang j., sievers j., loewer m., igel j., winsemann j. (2017) 3d architecture of cyclic step and antidune deposits in glacigenic subaqueous fan and delta settings: integrating outcrop and groundpenetrating radar data. sedimentary geology, 362, 83-100. lang j., lauer t., winsemann j. (2018) new age constraints for the saalian glaciation in northern central europe: implications for the extent of ice sheets and related proglacial lake systems, quaternary science reviews, 180, 240-259. lang j., le heron d., van den berg j.h., winsemann j. (2021) bedforms and sedimentary structures related to supercritical flows in glacigenic settings. sedimentology, 68: 1539-1579. doi: 10.1111/sed.12776 lee j. (2018) chapter 11 glacial lithofacies and stratigraphy. in: menzies j., van der meer j.j.m. (eds): past glacial environments (second edition), elsevier, 377-429. doi: 10.1016/b978-0-08-100524-8.00011-7 lenotti b. (1980) l’anfiteatro morenico atesino di rivoli veronese. vallagarina arti grafiche r. manfrini s.p.a., p. 24. laubscher h. (1985) large-scale, thin-skinned thrusting in the southern alps: kinematic models. geological society of america bulletin, 96, 710-718. mancini f. (1960) osservazioni sui loess e sui paleosuoli dell’anfiteatro orientale del garda e di quello di rivoli (verona). atti soc. it. scienze nat., 99, 221248. mancini f. (1969) notizie sui paleosuoli e sui loess dell’anfiteatro occidentale e frontale del garda. atti soc. it. scienze nat., 109 (2), 186-219. margottini c., vai g.b. (2004) climex maps italy, lithopalaeoenvironmental maps of italy during the last two climatic extremes. enea. mariani g.s., zerboni a., amit r., porat n., cremaschi m. (2015) the southernmost evidence in europe for upper pleistocene ice-wedge casts in loess (gajum, north italy). conference: batsheva de 49 lgm glaciolacustrine deposits from the adige moraine amphitheatre views, 226, 105964. doi: 10.1016/j.quascirev.2019.105964 panin a.v., astakhov v.i., lotsari e., komatsu g., lang j., winsemann j. (2020) middle and late quaternary glacial lake-outburst floods, drainage diversions and reorganization of fluvial systems in northwestern eurasia. earth-science reviews, 201, 103069. doi: 10.1016/j.earscirev.2019.103069 pawloski d., gruszka b., gallas h., petera-zganiacz j. (2013) changes in the biota and sediments of glacial lake koźmin, poland, during the late saalian (illinoian). journal of paleolimnology, 49, 679696. doi: 10.1007/s10933-013-9692-z penck a., brückner e. (1909) die alpen im eiszeitalter. tauchnitz, leipzig. picotti v., prosser g., castellarin a. (1995) structures and kinematics of the giudicarie-val trompia fold and thrust belt (central southern alps, northern italy). memorie di scienze geologiche, 47, 95-109. porto tapiquén e.c. (2015) "world countries". retrieved from http://tapiquen-sig.jimdo.com. orogénesis soluciones geográficas. based on shapes from enviromental systems research institute (esri). free distribution. powell r.d. (1990) glacimarine processes at grounding-line fans and their growth to ice-contact deltas. in: dowdeswell j.a., scourse j.d. (eds.), glacimarine environments: processes and sediments. geological society of london, special publication, 53, 53-73. qgis development team (2019) qgis geographic information system; version 3.4. open source geospatial foundation project. http://qgis.osgeo.org qgis development team (2021) qgis geographic information system; version 3.16. open source geospatial foundation project. http://qgis.osgeo.org ravazzi c., pini r., badino f., de amicis m., londeix l., remeir p.j. (2014) the latest lgm culmination of the garda glacier (italian alps) and the onset of glacial termination. age of glacial collapse and vegetation chronosequence. quaternary science reviews, 105, 26-47. regione veneto (2018) cartografia tecnica regionale numerica alla scala 1:5.000, geoportale regione veneto. richmond g.m. (1962) quaternary stratigraphy of the la sal mountains utah. geological survey professional paper, 342, 1-103. richmond g.m. (1986) stratigraphy and chronology of glaciations in yellowstone national park. in: sibrava v., bowen d.q., richmond g.m. (eds.), quaternary glaciations in the northern hemisphere. report igcp n°24. quaternary science reviews, 5(1-4), 83 98 rossato s., carraro a., monegato g., mozzi p., tateo f. (2018) glacial dynamics in pre-alpine narrow valleys during the last glacial maximum inferred by lowland fluvial records (northeast italy). earth surface dynamics, 6, 809-828. doi: 10.5194/esurf-6-809-2018 sacco f. (1896) l’anfiteatro morenico del lago di garda. ann. r. acc. agric. torino, 38, pp. 54. scardia g., festa a., monegato g., pini r., rogledi s., tremolada f., galadini f. (2015) evidence for late alpine tectonics in the lake garda area (northern italy) and seismogenic implications. gsa bullettin, 127, 113-130. shaw j. (1975) sedimentary successions in pleistocene ice-marginal lakes. in: jopling a.v., mcdonald b.c. (eds.), fluvioglacial and glaciolacustrine sedimentation. society of economic paleontologists and mineralogist, special publication, 23, 281 -303. shtober-zisu n., amasha h., frumkin a. (2015) inland notches: implications for subaerial formation of karstic landforms an example from the carbonate slopes of mt. carmel, israel. geomorphology, 229, 85-99. shur y., zhestkova t. (2003) cryogenic structure of a glacio-lacustrine deposit. in: phillips m., springman s.m., arenson l.u. (eds.), permafrost: proceedings of the 8th international conference on permafrost 2003. swets & zeitlinger, lisse, 10511056. sorbini l., accorsi c.a., bandini mazzanti m., forlani l., gandini f., meneghel m., rigoni a., sommaruga m. (1984) geologia e geomorfologia di una porzione della pianura a sud-est di verona. memorie del museo civico di storia naturale di verona (ii serie), sezione scienze della terra, 2, pp. 91. sutherland j.l., carrivick j.l., shulmeister j., quincey d.j., james w.h.m. (2019) ice-contact proglacial lakes associated with the last glacial maximum across the southern alps, new zealand. quaternary science reviews, 213, 67-92. doi: 10.1016/j.quascirev.2019.03.035 venzo s. (1957) rilevamento geologico dell'anfiteatro morenico del garda. parte i: tratto occidentale gardone-desenzano. memorie della società italiana di scienze naturali e del museo civico di storia naturale di milano, 12, 73 140. venzo s. (1961) rilevamento geologico dell’anfiteatro morenico del garda: parte ii: tratto orientale e anfiteatro atesino di rivoli veronese. memorie della società italiana di scienze naturali e del museo civico di storia naturale di milano, 13, pp. 64. venzo s. (1965) rilevamento geologico dell'anfiteatro morenico frontale del garda dal chiese all'adige memorie della società italiana di scienze naturali e del museo civico di storia naturale di milano, 14, 3 82. venzo s., lipparini t., perrella g., medioli f., malaroda r., sturani c., carraro f., zanella e., dal piaz g.b., corsi m., gatto g., piccoli g. (1969) carta geologica d’italia foglio 48 ‘peschiera del garda’. italian geological survey, rome, 1:100.000 scale geological map. winsemann j., hornung, j.j., meinsen j., asprion u., polom u., brandes c., bußmann m., weber c. (2009) anatomy of a subaqueous ice-contact fan and delta complex, middle pleistocene, nw ger 50 pezzotta a. et al zavala c., pan s.x. (2018) hyperpycnal flows and hyperpycnites: origin and distinctive characteristics. lithologic reservoirs, 30 (1), 1-27. zervas d., nichols g.j., hall r., smyth h.r., lüthje c., murtagh f. (2009) sedlog: a shareware program for drawing graphic logs and log data manipulation. computers & geosciences, 35, 2151-2159. many. sedimentology, 56, 1041-1076. winsemann j., lang j., polom u., loewer m., igel j., pollok l., brandes c. (2018) ice-marginal forced regressive deltas in glacial lake basins: geomorphology, facies variability and large-scale depositional architecture. boreas, 47(4), 973-1002. doi: 10.1111/bor.12317 wirsig c., zasadni j., christl m., akçar n., ivy-ochs s. (2016) dating the onset of lgm ice surface lowering in the high alps. quaternary science reviews, 143, 37-50. 51 ms. received: october 5, 2023 revised: january 5, 2024 accepted: january 15, 2024 available online: jannuary 30, 2024 lgm glaciolacustrine deposits from the adige moraine amphitheatre i depositi del pleistocene inferiore della bassa val di cecina (toscana, italia): ricostruzione stratigrafico–deposizionale e proposta di suddivisione in unita’ allostratigrafiche giovanni sarti1, andrea ciampalini2, ilaria consoloni1 & andrea cerrina feroni3 1dipartimento di scienze della terra, via s. maria 53, pisa, sarti@dst.unipi.it 2dipartimento per lo studio del territorio e delle sue risorse, corso europa 26, genova, andrea.ciampalini@dipteris.unige.it 3istituto di geoscienze e georisorse, via s. maria 53, pisa, cerrina@dst.unipi.it riassunto: sarti et al. i depositi del pleistocene inferiore della bassa val di cecina (toscana, italia): ricostruzione stratigrafico–deposizionale e proposta di suddivisione in unita’ allostratigrafiche (it issn 0394-3356, 2007). nella zona compresa fra gli abitati di riparbella e casale marittimo (bassa val di cecina, toscana, italia) affiorano diffusamente depositi pleistocenici. attraverso un rilevamento di dettaglio ed un’analisi di facies sono state individuate, all’interno dei depositi del pleistocene inferiore, cinque unità litostratigrafiche successivamente raggruppate in tre unità allostratigrafiche (ua). la più antica (ua7), discordante sui depositi pre-quaternari, è costituita da due unità litostratigrafiche di ambiente marino-deltizio, in parziale eteropia (“conglomerati delle ginepraie” e “sabbie ed argille ad arctica islandica”) organizzate in un ciclo trasgressivo-regressivo. la seconda (ua6), che giace in discordanza angolare sulla ua7, è anch’essa costituita da due unità (“conglomerati delle lame” e “arenarie e sabbie di montescudaio”) di ambiente marino litorale delle quali è preservata solo la porzione trasgressiva. la terza (ua5, “conglomerati di serra all’olio”) discordante sulle precedenti si è invece depositata in un ambiente fluviale di tipo braided. la posizione stratigrafica di questa unità rende probabile una sua attribuzione al pleistocene medio. questo tipo di ricostruzione stratigrafico deposizionale differisce fortemente dalle precedenti interpretazioni. abstract: g. sarti et.al., stratigraphic and depositional reconstruction of the lower pleistocene deposits from lower val di cecina (tuscany, italy): a proposal of subdivision in allostratigraphic units. (it issn 0394-3356, 2007). in the area comprised between the villages of riparbella and casale marittimo (lower cecina valley, tuscany, italy) a large amount of pleistocene deposits outcrops. through a detailed geological survey integrated with facies analysis five litostratigraphic units, grouped in three allostratigraphic units (ua), have been detected. the oldest (ua7), lower pleistocenic in age, is formed by two litostratigraphic units (“conglomerati delle ginepraie” and “sabbie ed argille ad arctica islandica”) showing latero-vertical relationships and are organized in a transgressive-regressive cycle. the “conglomerati delle ginepraie” are arranged in a fining upwards trend and were deposited in small coalescent deltaic environments. three depositional facies are recognized within the “sabbie ed argille ad arctica islandica” recording a fining-coarsening and deepening shallowing upward trend. the ua7 lies in unconformity above pre-quaternary deposits. the second (ua6), lower pleistocenic in age, is also constituted by two heteropic and transgressive litostratigraphic units (“conglomerati delle lame” and “arenarie e sabbie di montescudaio”) lying in angular unconformity on the ua7. the “conglomerati delle lame”, showing a well developed imbrication, were deposited in a foreshore to upper shoreface depositional environment. the “arenarie e sabbie di montescudaio” are characterized by a high to low planar-cross stratification and sometimes by overturned stratification and were deposited in a shallow marine environment. the regressive phase of this ua is not preserved due to erosive processes. the youngest unit (ua4, “conglomerati di serra all’olio”), was instead deposited in fluvial-braided environment and lies in angular unconformity on the others ua. the middle pleistocenic age of this unit has been inferred on the basis of its stratigraphic position. this stratigraphic reconstruction strongly conflict from previous interpretations. important climatic and geological remarks derive from the finding of two taxa (arctica islandica and the coral cladocora caespitosa) at different stratigraphic positions within the oldest unit (“sabbie ed argille ad arctica islandica”). the arctica islandica testifying cold temperatures (4°c to 13°c) characterizes the first 5 meters of the unit, while beds of cladocora caespitosa (15°c to 22°c the temperature range of this coral) only occur upwards. we retain that the deposition of the “sabbie ed argille ad arctica islandica” takes place during a warming phase and that the development of cladocora caespitosa beds could be related to the maximum flooding conditions at the end of the transgressive phase. this interpretation leads to some notable chronostratigraphic implications. parole chiave: rilevamento geologico, analisi di facies, pleistocene inferiore, unità allostratigrafiche, val di cecina. keywords: geological survey, facies analysis, lower pleistocene, allostratigraphic units, val di cecina. il quaternario italian journal of quaternary sciences 20(2), 2007 151-162 1. introduzione l’area di studio ubicata nella bassa val di cecina, tra gli abitati di riparbella e casale marittimo (fig. 1), è stata rilevata alla scala 1:10.000 (cerrina feroni et al., 2003) nell’ambito del progetto carg finanziato dalla regione toscana insieme a tutta la porzione costiera che si sviluppa da piombino fino a livorno, dove sono particolarmente sviluppati depositi quaternari. da un punto di vista generale questa area è caratterizzata da un insieme di bacini estensionali, sviluppatisi nella toscana a sud dell’arno, come conseguenza di una tettonica a carattere prevalentemente distensivo che ha interessato, a partire dal tortoniano superiore, l’intero versante occidentale della catena appenninica in risposta ai processi di apertura del mar tirreno ed alla contemporanea migrazione antioraria del sistema catenaavanfossa-avampaese (malinverno & ryan, 1986; sartori, 1990; martini & sagri, 1993; patacca et al., 1993; meletti et al., 1995). la maggior parte di questi bacini, a direzione appenninica, è stata riempita, a partire dal tortoniano superiore, da una notevole quantità di sedi152 g. sarti et al. menti neogenico-quaternari (lazzarotto & mazzanti, 1978; ambrosetti et al., 1979; bossio et al., 1981; giannelli et al., 1981; mazzanti, 1983; mazzanti & sanesi, 1987; bossio et al., 1993; sarti, 1995; boschian et al., 2006. in particolare nell’area di studio sono distribuiti diffusamente sedimenti quaternari depostisi prevalentemente in ambienti paralici caratterizzati da rapide variazioni latero-verticali, la cui restituzione cartografica, considerata anche la non eccellente qualità e quantità di affioramenti, non è sempre stata agevole. in questo senso seguire le linee guida raccomandate dal carg, che suggeriscono di procedere alla suddivisione delle varie unità in unconformity bounded stratigraphic units ubsu (apat, 1992) in accordo con le indicazioni dell’international subcommission on stratigraphic classification (iscc, salvador, 1994) ha posto non pochi problemi. il potenziale di applicabilità di tale tipo di unità nella toscana marittima è stato discusso in sarti & guidi (2005), a cui si rimanda per approfondimenti, che propongono di utilizzare una suddivisione in unità allostratigrafiche (ua). in particolare sarti & guidi (2005) propongono di suddividere i depositi quaternari estesi tra piombino e livorno in 7 ua (fig. 2), numerate informalmente dalla più giovane alla più antica, senza però entrare nel dettaglio della descrizione puntuale dei dati relativi alle caratteristiche stratigraficodeposizionali di ciascuna ua. nel presente lavoro vengono descritte le caratteristiche stratigrafico-deposizionali delle tre ua basali (ua7, ua6 e ua4 in sarti & guidi, 2005), distribuite nella bassa val di cecina, nelle quali sono state ulteriormente divise ed accorpate le formazioni corrispondenti in letteratura (giannelli et al., 1981; mazzanti, 1983; mazzanti & sanesi, 1987; bossio et al., 1993; boschian et al., 2006 ) alle “sabbie ed argille ad arctica islandica”, ai “conglomerati di villa magrini”, ai ”conglomerati di riparbella” ed ai “calcari di montescudaio”. fig. 1 area di studio e carta geologica schematica. study area and schematic geological map. 2. metodi considerato che l’obiettivo dello studio è stato quello di definire e tracciare cartograficamente limiti che delimitassero unità inconformi si è cercato un approccio metodologico il più possibile interdisciplinare che permettesse di dedurre, laddove tali limiti non fossero visibili e seguibili sul terreno (così come invece richiederebbe la definizione di ubsu), cambiamenti bruschi di facies e dunque discontinuità. essendo questa la situazione ricorrente è sembrato più corretto (sarti & guidi, 2005) utilizzare le unità allostratigrafiche nella cui definizione viene ammessa la possibilità di poter tracciare limiti attraverso aree dove questi non siano visibili sul terreno. il rilevamento, effettuato alla scala 1:10.000 delle sezioni 294040 (riparbella) e 294080 (guardistallo) della carta tecnica regionale della regione toscana, integrato da fotointerpretazione, è stato compiuto producendo inizialmente una carta degli affioramenti in modo da separare il più possibile il dato dall’interpretazione. sono state misurate, campionate (oltre 200 i campioni raccolti ed analizzati) e ricostruite più sezioni stratigrafi153i depositi del pleistocene inferiore ... che, che attraverso l’analisi di facies, integrata con i risultati del contenuto paleontologico, hanno permesso di definire l’evoluzione nel tempo e nello spazio dei vari ambienti deposizionali e di individuare così le relazioni geometriche tra le varie unità litostratigrafiche cartografate. infine, essendo varie unità costituite da conglomerati, si è anche proceduto, utilizzando il metodo di howard (1993), ad una analisi composizionale quantitativa dei clasti allo scopo di acquisire ulteriori elementi discriminanti circa le possibili correlazioni. 3. stratigrafia per non incrementare il numero, peraltro già eccessivo, dei nomi attribuiti alle varie unità litostratigrafiche cartografate si è cercato, dove possibile, di fig. 2 proposta di suddivisione in unità allostratigrafiche nel tratto costiero compreso tra piombino e livorno (modificata da sarti & guidi, 2005). proposal of subdivision in allostratigraphic units in the zone comprised between piombino and livorno (modified after sarti & guidi, 2005). 154 conservare la nomenclatura presente in letteratura (giannelli et al., 1981; mazzanti, 1983; mazzanti & sanesi, 1987). fatta questa premessa i raggruppamenti in ua proposti per i depositi del pleistocene inferiore (giannelli et al., 1981), sono di seguito descritti, dal basso verso l’alto, mantenendo la numerazione già proposta in sarti & guidi (2005) (fig. 2). 3.1 unità allostratigrafica 7 (pleistocene inferiore) questa unità giace in discordanza angolare sui depositi pre-quaternari ed è costituita da due unità litostratigrafiche in reciproci rapporti di latero-verticalità: i “conglomerati delle ginepraie” che corrispondono alla parte basale dei “conglomerati di riparbella” di giannelli et al. (1981) e a parte dei “conglomerati di v.la magrini” di boschian et al. (2006) e le “sabbie ed argille ad arctica islandica” (fig. 2). 3.1.1 “conglomerati delle ginepraie” giacciono discordanti e con superficie erosiva sia direttamente sul substrato pre-neogenico sia sui depositi mio-pliocenici con uno spessore compreso tra 5 e 20 m ed hanno un’estensione limitata essendo presenti esclusivamente a nord del fiume cecina a ridosso dei rilievi costituiti dalle unità liguri (fig. 1). l’inclinazione degli strati è piuttosto forte (25°÷30°) e può raggiungere anche 45° con immersione verso sw. nel complesso si tratta di conglomerati mal classati, organizzati in un trend generale fining upward, con clasti da angolari a sub-arrotondati, la cui dimensione può raggiungere i 25 cm, sostenuti prevalentemente da una matrice sabbiosa (fig. 3). procedendo verso s-sw la granulometria tende rapidamente a diminuire, i conglomerati aumentano il proprio grado di classazione, di arrotondamento dei clasti, di organizzazione interna (presenza di stratificazione incrociata planare) e compaiono intercalazioni di sabbia grossolana a stratificazione incrociata planare e concava, che progressivamente sostituiscono il conglomerato stesso e vengono a definire la base delle “sabbie ed argille ad arctica islandica”. da un punto di vista composizionale il conglomerato riflette la natura del substrato affiorante. così, mentre nella zona di riparbella i clasti hanno una composizione prevalentemente ofiolitica (90% circa) e subordinatamente derivano dalla loro copertura sedimentaria, verso est diminuiscono i clasti ofiolitici (40%) ed aumentano notevolmente quelli costituiti da diaspri (45%) (tab. 1). nella matrice sono dispersi frammenti abrasi di bivalvi e di gasteropodi oltre a numerosi microfossil i , prevalentemente mil iol idi, anch’essi fluitati. i caratteri tessiturali e sedimentologici associati all’evidenza dei rapporti di latero-verticalità che i “conglomerati delle ginepraie” mostrano con l’unità marina delle “sabbie ed argille ad arctica islandifig. 3 affioramento dei “conglomerati delle ginepraie” nei pressi di riparbella. “conglomerati delle ginepraie” outcrop near riparbella. ca” suggeriscono una loro deposizione in ambienti di piccoli fan delta coalescenti, alimentati da aree distinte e localizzati allo sbocco di piccoli sistemi fluviali. l’eteropia con le “sabbie ed argil le ad arctica islandica” permette di datare questa ua al pleistocene inferiore. 3.1.2 sabbie ed argille ad arctica islandica le “sabbie ed argille ad arctica islandica”, il cui spessore è compreso tra 15 e 200 m, giacciono in discordanza sui terreni pre-pleistocenici e mostrano rapporti di latero-verticalità con i “conglomerati delle ginepraie” (fig. 1). gli strati, immergono mediamente di circa 25° verso sw. sono state riconosciute tre facies deposizionali principali (a,b,c) che nel complesso descrivono un trend fining-coarsening e deepening-shallowing upward. la prima facies deposizionale (a), spessa pochi metri, caratterizza la base delle “sabbie ed argille ad arctica islandica” ed è costituita da sabbie a granulometria medio-grossolana, bioturbate e massive, anche se localmente è stata osservata una stratificazione incrociata planare a basso angolo. al passaggio con i “conglomerati delle ginepraie” si osservano frequentemente dispersi, al loro interno, clasti di dimensioni ruditiche fini, comprese tra pochi millimetri e 2 cm, che riflettono la composizione del conglomerato stesso, e abbondanti macrofossili (ostreidi, pectinidi e veneridi, tra cui arctica islandica) in cattivo stato di conservazione. le microfaune sono anch’esse abbondanti anche se visibilmente trasportate. le forme più frequenti sono rappresentate da ammonia beccarii ed elphidium crispum di grandi dimensioni e da miliolidi. verso l’alto queste sabbie passano gradualmente alla seconda facies deposizionale (b) costituita da alternanze fra livelli di arenarie e sabbie a granulometria media con stratificazione incrociata planare ad alto angolo o piano-paralg. sarti et al. 155 lela e visibili prevalentemente a sud del fiume cecina. contengono numerosi macrofossili costituiti principalmente da ostreidi e pectinidi (fig. 4) e subordinatamente da accumuli di cladocora caespitosa. le microfaune, anch’esse molto abbondanti, sono dominate da ammonia beccarii ed elphidium crispum, spesso associati ad altre forme come florilus boueanum e lobatula lobatula. la terza facies deposizionale (c) giace, laddove visibile, con contatto netto sulla seconda facies deposizionale (b) ed è costituita da sabbie a granulometria medio-grossolana color grigio-arancio con stratificazione incrociata planare a basso angolo o stratificazione tipo wavy bedding. e’ osservabile in modo discontinuo prevalentemente a nord del fiume cecina dove sono stati osservati anche slump (fig. 5). da un punto di vista microfaunistico questa unità deposizionale è caratterizzata dalla presenza saltuaria di foraminiferi con evidenti segni di trasporto associata a rari esemplari di ilyocypris gibba indicativi di ambiente dulcicolo. alcuni campioni sono invece caratterizzati da faune dominate dal gruppo ammonia tepida ammonia parkinsoniana ed esemplari di lobatula lobatula ad avvolgimento irregolare. nell’insieme si tratta, dunque, di un’associazione faunistica tipica di un ambiente costiero soggetto a frequenti variazioni di salinità determinate da periodici influssi fluviali. le “sabbie ed argille ad arctica islandica” registrano un ciclo trasgressivo-regressivo caratterizzato alla base (facies a) da depositi di ambiente marino litorale (shoreface superiore) in progressivo approfondimento fino ad uno di shoreface inferiore (facies b. la facies (c) indica, invece, un trend regressivo testimoniato da depositi di fronte deltizia. le “sabbie ed argille ad arctica islandica” sono state attribuite ad un “pleistocene inferiore non molto inoltrato” (giannelli et al., 1981) per la presenza di ospiti nordici, tra cui arctica islandica, e la contemporanea presenza di turritella vermicularis, sopravvissuto pliocenico (giannelli et al., 1981; ragaini & menesini, 1997) e di nucula piacentina e tellina corbis, estintesi nella parte terminale del siciliano sensu ruggieri & sprovieri (1975) secondo mazzanti (1983) e mazzanti & sanesi (1987). inoltre, il ritrovamento in livelli argillosi provenienti da sondaggi perforati nella piana di vada, ad ovest dell’area di studio, di nannofossili calcarei riferit i al la zona gephyrocapsa oceanica calcidiscus macintyrei da giannelli et al. (1981) consentono l’attribuzione di questa unità alla zona ad arctica islandica di ruggieri & sprovieri (1975 e 1977) e quindi sono riferiti da bossio et al. (1993) al santerniano sensu ruggieri & sprovieri (1975). tuttavia è importante sottolineare che è stato recentemente proposto (catanzariti et al., 2002) di anticipare la comparsa di arctica islandica nel mediterraneo al gelasiano. 3.2 unità allostratigrafica 6 (pleistocene inferiore) questa ua (fig. 2) giace in discordanza angolare e con base erosiva sulla ua7 ed è costituita dai “conglomerati delle lame”, corrispondenti a parte dei “ conglomerati di riparbella “ di giannelli et al. (1981) e di mazzanti & sanesi (1987) e dalle “arenarie e sabbie di montescudaio”, equivalenti a parte dei “calcari sabbiosi di montescudaio” degli stessi aa.. queste due unità litostratigrafiche mostrano reciproci rapporti di lateroverticalità. 3.2.1 conglomerati delle lame giacciono in discordanza angolare e con base erosiva sulle “sabbie ed argille ad arctica islandica” con spessori compresi tra 10 e 20 m e sono organizzati composizione dei conglomerati o d l t n a ua 7 conglom. delle ginepraie proggi (1) 97,75% 1,00% 0,50% 0,00% 0,00% 0,75% serra all'olio (2) 80,75% 6,50% 12,75% 0,00% 0,00% 0,00% botro delle ginepraie (3) 84,00% 1,50% 14,50% 0,00% 0,00% 0,00% urlari (4) 41,25% 44,00% 14,50% 0,00% 0,00% 0,25% ua 6 conglomerato delle lame botro spadini (5) 1,25% 16,00% 70,75% 3,00% 2,25% 6,75% riparbella (6) 3,00% 6,25% 69,00% 5,50% 3,50% 12,75% le giuncaie (7) 0,00% 4,00% 72,50% 2,00% 2,50% 19,00% montescudaio nord (8) 3,00% 12,00% 78,00% 2,00% 5,00% 0,00% podere fedeli (9) 1,75% 4,00% 77,50% 5,00% 3,25% 8,50% i salacchi (10) 1,00% 10,00% 60,00% 7,00% 2,00% 20,00% montescudaio sud (11) 4,25% 9,00% 68,00% 0,00% 2,00% 16,75% le serre (12) 2,75% 11,50% 68,00% 7,75% 5,75% 4,25% ua 4 conglom. di serra all'olio pod. felciaione (13) 9,00% 6,25% 75,25% 6,25% 2,25% 1,00% serra all'olio (14) 2,75% 11,50% 68,00% 7,75% 5,75% 4,25% le cerretelle (15) 0,25% 11,00% 65,25% 8,50% 5,00% 10,00% tab. 1 composizione litologica dei conglomerati nelle località campionate. per ogni località sono stati conteggiati 400 clasti. o = ofioliti, d = diaspri, l = calcari e arenarie del dominio ligure, t = clasti delle formazioni del dominio toscano, n = clasti delle formazioni neogeniche, a = indeterminabili e alterati. il numero si riferisce alla fig. 1. conglomerates lithologic composition in the sampled areas. 400 clasts have been collected for each area. o = ophiolites, d = jasper, l = limestone and sandstone of the ligurian domaine, t = tuscan formations clasts, n = neogenic formations clasts, a = unknown or altered. numbers refered to fig. 1. i depositi del pleistocene inferiore ... 156 segnalati in precedenza (tab. 1). tali clasti, anche se poco numerosi (4%), non sono stati ritrovati nei “conglomerati delle ginepraie” e testimoniano un qualche cambiamento, sia dell’area di alimentazione sia del sistema di drenaggio. i “conglomerati delle lame” sono attribuiti al pleistocene inferiore sulla base dei loro rapporti eteropici con le “arenarie e sabbie di montescudaio”. 3.2.2 arenarie e sabbie di montescudaio mostrano rapporti di latero-verticalità (fig. 2) coi “conglomerati delle lame” con inclinazioni modeste (intorno ai 5÷10°)” e sono in discordanza angolare sulle “sabbie ed argille ad arctica islandica”. questa unità litostratigrafica (fig. 1), di spessore compreso tra 10 e 20 m, è caratterizzata da areniti con frazione carbonatica variabile e diverso grado di cementazione. l’analisi petrografica di alcuni campioni ha evidenziato come questi depositi siano più correttamente classif icabil i come arenarie ibride sensu zuffa (1980). per questo motivo si è deciso di cambiare la denominazione litologica originaria (calcari sabbiosi di montescudaio, di giannelli et al., 1981 o più recentemente “calcari di montescudaio” di boschian et al ., 2006) in “arenarie e sabbie di montescudaio”. insieme ai “conglomerati delle lame” costituiscono un nuovo ciclo fig. 5 pieghe da slump nella porzione stratigraficamente alta delle “sabbie ed argille ad arctica islandica”. slump structure in the upper portion of “sabbie ed argille ad arctica islandica”. in un trend complessivo f ining upward. si tratta di un conglomerato clasto-sostenuto, localmente matrice-sostenuto, moderatamente classato, con granulometria compresa fra pebble e cobble con grado di arrotondamento variabile da subarrotondato ad arrotondato e forma dei clasti frequentemente tabulare. i clasti mostrano inoltre un embricamento che si sviluppa sia lungo l’asse maggiore sia lungo quello minore (ap; ai e at; bi sensu harms et al., 1982) e talvolta sono organizzati in lamine a gradazione inversa. lateralmente i conglomerati sono eteropici con sabbie a stratificazione incrociata planare a basso angolo, che costituiscono la porzione basale delle “arenarie e sabbie di montescudaio” (fig. 6); tale eteropia rappresenterebbe, secondo massari & parea (1988), un elemento caratterizzante di un ambiente di shoreface superiore / foreshore tipico delle spiagge ghiaiose. l’ambiente marino litorale, verosimilmente ad alta energia, è anche testimoniato dalla presenza seppur scarsa di microfaune oligotipiche (elphididi e rotalidi) e di bivalvi marini (ostreidi e glycimeridi) fortemente abrasi e dalla gradazione inversa osservata in alcune lamine conglomeratiche indicativa di processi di trazione da onda su battigia (ricci lucchi, 1980). significativi i dati relativi alla composizione del conglomerato per la presenza, all’interno di un’alimentazione derivante prevalentemente dalla copertura sedimentaria delle ofioliti (circa 70%), di clasti provenienti dalla falda toscana e dal suo substrato mai g. sarti et al. fig. 4 accumulo di macrofossili nei livelli basali delle “sabbie ed argille ad arctica islandica”. macrofossils’s accumulation at the base of “sabbie ed argille ad arctica islandica”. trasgressivo del quale non è visibile la porzione regressiva sia perchè erosa delle ua sovrastanti (“conglomerati di serra all’olio, “conglomerati di bolgheri”) sia perché sono preservati invariabilmente in posizioni strutturali alte (fig. 1). le “arenarie e sabbie di montescudaio” sono caratterizzate da un passaggio per alternanza ai “conglomerati delle lame” e sono costituite da sabbie più o meno cementate a stratificazione incrociata planare da basso ad alto angolo e localmente da stratificazione tipo overturned (fig.7). il contenuto faunistico è assente o caratterizzato da associazioni povere costituite esclusivamente da rotalidi ed elphididi fortemente abrasi. nel complesso, dunque, le “arenarie e sabbie di montescudaio” registrano un nuovo ciclo trasgressivo caratterizzato da depositi di shoreface superiore che si interdigitano con i depositi di foreshore/shoreface superiore ghiaioso costituiti dai “conglomerati delle lame”. interessante la presenza nella porzione basale di stratificazione overturned. per questo tipo di stratificazione è stata invocata da vari autori un’origine sismogenetica (si veda ad esempio allen & banks, 1972; owen, 1995; davies et al., 2004) anche se doe & dott (1980) indicano le medesime strutture come causate dall’elevato tasso di apporto sedimentario e dunque a meccanismi di soft deformation sinsedimentaria. nel caso in esame la presenza latero-verticale di depositi riferibili a spiagge ghiaiose e dunque verosimilmente alimentati da un sistema deltizio vicino, sono compatibili con il meccanismo deposizionale proposto da doe & dott (1980), anche se la causa sismogenetica non può essere a priori esclusa. come già accennato nella parte introduttiva le “arenarie e sabbie di montescudaio” corrispondono solo in parte ai “calcari sabbiosi di montescudaio” definiti da giannelli et al., 1981 ed in particolare solo alla porzione stratigraficamente più alta di questi. infatti, sulla base dei dati acquisiti, è evidente la riduzione di spessore delle “arenarie e sabbie di montescudaio”, stimata al massimo in 30 m, in accordo con moratti et al. (2003), rispetto alla stima di 100 m dei lavori precedenti (giannelli et al ., 1981; mazzanti, 1983; mazzanti & sanesi, 1987; bossio et al., 1993; costantini et al., 1993; boschian et al., 2006). in questi lavori il limite fra le “sabbie ed argille ad arctica islandica” e i “calcari di montescudaio” viene posto, sostanzialmente, in corrispondenza di un cambiamento del grado di cementazione che coincide con la base dei “calcari di montescudaio” (boschian et al ., 2006, cum biblio). tuttavia, indipendentemente dal grado di cementazione, le caratteristiche stratigrafico-deposizionali, di facies ed il contenuto faunistico sono gli 157 fig. 6 stratificazione incrociata planare a basso angolo e interdigitazioni sabbiose nei “conglomerati delle lame”. low-angle planar cross-stratification in the “conglomerato delle lame”. fig. 7 overturned cross-stratification nelle “arenarie e sabbie di montescudaio”. overturned cross-stratification in the “arenarie e sabbie di montescudaio”. i depositi del pleistocene inferiore ... stessi. inoltre, anche in porzioni sicuramente attribuibil i al le “sabbie ed argille ad arctica islandica” anche da parte dei precedenti autori, si ritrovano, con relativa frequenza, livelli con un grado di cementazione assolutamente paragonabile a quello dei “calcari di montescudaio” auct.. il grado di cementazione e dunque la percolazione del carbonato di calcio è, a nostro avviso, imputabile spesso a cause secondarie, come ad esempio la forte decarbonatazione dei sovrastanti depositi del pleistocene medio (“conglomerati di bolgheri”) che affiorano proprio nelle zone dove i sedimenti del pleistocene inferiore appaiono più cementati. riteniamo, dunque, che la distinzione tra i “calcari di montescudaio” auct. e le “sabbie ed argille ad arctica islandica” sia stata basata su un criterio (grado di cementazione) non valido. come conseguenza di queste considerazioni, confortate dai dati di rilevamento e di analisi di facies, buona parte dei “calcari di montescudaio” auct., viene incorporata, nel presente lavoro, nella “sabbie ed argille ad arctica islandica”, mentre gli spessori modesti che rimangono di pertinenza del “ciclo di montescudaio” (“arenarie e sabbie di montescudaio”) sono separati, in evidente discordanza angolare, dalle “sabbie ed argille ad arctica islandica” dai “conglomerati delle lame” ed hanno caratteristiche deposizionali decisamente differenti. l’implicazione cronostratigrafica di questo ragionamento, che associa una posizione stratigrafica più alta alla base delle “arenarie e sabbie di montescudaio”, è il ringiovanimento dell’unità litostratigrafica stessa rientrando, a nostro parere, nelle “sabbie ed argille ad arctica islandica” le associazioni emiliane (sensu ruggieri & sprovieri, 1975) di acque fredde (arctica islandica e mya truncata) segnalate alla base (si veda la fig. 9) da giannelli et al., 1981 158 fig. 8 base erosiva e canalizzazione nei “conglomerati di serra all’olio”. channel basal erosion and channel fill in the “conglomerati di serra all’olio”. fig. 9 schema morfostratigrafico del pleistocene della toscana costiera proposto nei precedenti lavori. (ridisegnato da boschian et al., 2006). la fm. di san marco, la fm. di bibbona la fm. case saracino e la fm. delle fabbriche non sono presenti nell’area di studio. morphostratigraphic sketch of the pleistocene of the “coastal tuscany” based on previous interpretations. (redrawn after boschian et al., 2006). san marco, bibbona,. case saracino and delle fabbriche fms. are not present in the studied area. g. sarti et al. 3.3 unità allostratigrafica 4 (pleistocene medio?) questa unità presente solo nella zona di studio è costituita da un'unica unità litostratigrafica denominata “conglomerati di serra all’olio” (fig. 2). viene descritta perché i conglomerati che la costituiscono erano stati associati, nei precedenti lavori (giannelli et al., 1981; mazzanti & sanesi, 1987; boschian et al., 2006), ai “conglomerati di riparbella”. i dati acquisiti ne attestano invece la giacitura discordante ed erosiva sia sull’ua7 sia sulla ua6 (fig.1). 3.3.1 conglomerati di serra all’olio i “conglomerati di serra all’olio” sono preservati soprattutto a nord del fiume cecina e costituiscono un corpo, a giacitura sub-orizzontale, che si sovrappone in discordanza angolare con base erosiva su entrambe le unità litostratigrafiche dell’ua6. spesso circa 10÷15 m, è costituito da un conglomerato matrice-sostenuto, moderatamente classato (fig. 8) con clasti da subarrotondati ad arrotondati con dimensioni variabili da pebble a cobble, frequentemente embricati lungo l’asse minore (at; bi sensu harms et al., 1982). la matrice è costituita da sabbia a granulometria medio-grossolana di colore giallastro che localmente forma lenti o livelli di sabbia più o meno continui. in alcuni casi sono stati osservati livelli centimetrici di argilla al cui interno sono stati riconosciuti esemplari di ostracodi dulcicoli (candona spp. e ilyocypris gibba). stratificazione incrociata planare ad alto angolo o concava, canalizzazioni e sequenze di riempimento di canale costituiscono un elemento ricorrente dei “conglomerati di serra all’olio”. dal punto di vista composizionale, invece, questi risultano essere molto simili ai “conglomerati delle lame”, essendo i clasti costituiti in netta prevalenza dai calcari e dalle arenarie della copertura sedimentaria delle ofioliti, ma contenendo anche clasti provenienti dalle formazioni del dominio toscano (tab. 1). a questi si aggiungono localmente anche clasti appartenenti alle sottostanti “arenarie e sabbie di montescudaio”. l’insieme delle osservazioni e dei dati raccolti suggerisce che i “conglomerati di serra all’olio” si siano deposti in ambiente continentale, all’interno di un sistema fluviale di tipo braided con trasporto al fondo prevalentemente ghiaioso (sensu orton & reading, 1993). non sono disponibili criteri paleontologici per inquadrare da un punto di vista cronostratigrafico questa nuova unità. tuttavia la posizione stratigrafica discordante ed erosiva al di sopra delle “arenarie e sabbie di montescudaio” e la presenza, nel conglomerato, di clasti appartenenti a queste ultime nel conglomerato implica un’età sicuramente più recente delle “arenarie e sabbie di montescudaio” e probabilmente riferibile alla base del pleistocene medio. 4. discussione e conclusioni rilevamento ed analisi di facies hanno permesso di riconoscere, nei depositi del pleistocene inferiore della bassa val di cecina, cinque unità litostratigrafiche raggruppabili in tre unità allostratigrafiche. la più antica (ua7) giace discordante sui depositi pre-pleistocenici ed è costituta nelle porzioni più prossimali da conglomerati (“conglomerati delle ginepraie”) organizzati in trend fining-upward che composizionalmente riflettono la natura del substrato circostante e riferibili a depositi di fan delta che si interdigitano con sabbie grossolane (parte basale delle “sabbie ed argille ad arctica islandica”) di ambiente marino litorale. la porzione intermedia e sommitale delle “sabbie ed argille ad arctica islandica” registra un approfondimento del sistema deposizionale fino ad uno shoreface inferiore prima e successivamente una inversione del trend deposizionale con evidenze di progradazione deltizia. data la scarsità di affioramenti di questa ultima facies deposizionale non può essere a priori esclusa la presenza di una eventuale discontinuità, seppur di ordine minore (cerrina feroni et al., 2005; sarti & guidi, 2005), tra questa e le sottostanti. su questa ua giace in discordanza angolare la ua6 della quale è conservata solo la porzione trasgressiva caratterizzata alla base da conglomerati relativi a spiagge ghiaiose (“conglomerati delle lame”) alimentate da un sistema fluviale che doveva essere attivo nelle vicinanze. i conglomerati passano lateralmente e verso l’alto ad arenarie e sabbie (“arenarie e sabbie di montescudaio”) deposte in uno shoreface superiore. e’ importante notare che la composizione dei “conglomerati delle lame” differisce da quella di “conglomerati delle ginepraie” per la presenza di elementi riferibili alla falda toscana (tab. 1) che indicano, quindi, un cambio ed un ampliamento del bacino di drenaggio, la cui definizione necessita, però, di ulteriori studi in corso di svolgimento. infine i “conglomerati di serra all’olio” (ua4), che costituiscono l’unità più giovane illustrata in questo lavoro, giacciono discordanti su la ua6 e registrano un netto cambiamento dell’ambiente deposizionale con l’impostazione di un sistema fluviale di tipo braided, caratterizzato da prevalente trasporto al fondo ghiaioso. questo tipo di ricostruzione stratigrafico-deposizionale differisce fortemente da quanto precedentemente proposto in letteratura (giannelli et al., 1981; mazzanti, 1983; mazzanti & sanesi, 1987; bossio et al., 1993; boschian et al., 2006) dove l’insieme di questi depositi (“conglomerati di v.la magrini”, “conglomerati di riparbella”, “sabbie ed argille ad arctica islandica” e “calcari sabbiosi di montescudaio”) erano considerati come facenti parte di un unico ciclo trasgressivoregressivo (fig.9). peraltro, già in questi lavori erano più o meno evidenti dati contrastanti con questo tipo di interpretazione (ciclo unico): ad esempio osservando la figura dei rapporti stratigrafici (boschian et al., 2006) (fig. 9) i “calcari di montescudaio” sono contemporaneamente trasgressivi e regressivi oppure osservando le carte geologiche di giannelli et al. (1981), di mazzanti & sanesi (1987), e di costantini et al. (1993), e di dove la medesima unità, nonostante costituisca la porzione regressiva del ciclo, appoggia direttamente “trasgressiva” sul substrato pre-pleistocenico. comunque, in sintesi ed in modo più organico, le differenze rispetto ai precedenti lavori riguardano: i) la riorganizzazione dei “conglomerati di riparbella” e “conglomerati di villa magrini” (giannelli et al., 1981; mazzanti, 1983; mazzanti & sanesi, 1987; boschian et al., 2006) in tre differenti unità litostratigrafiche (“conglomerati delle ginepraie”, “conglomerati delle lame”, “conglomerati di serra all’olio”) con differenti caratteristiche deposizionali e composizionali ed appartenenti a tre unità a limiti inconformi distinte; ii) l’evidenza dei rapporti di lateroverticalità tra i “conglomerati delle ginepraie” con le 159i depositi del pleistocene inferiore ... “sabbie ed argille ad arctica islandica” nelle quali è stato individuato un ciclo trasgressivo-regressivo; iii) la presenza di una discordanza angolare tra questa ua e la soprastante (ua6) nella quale sono stati definiti i rapporti di latero-verticalità tra i “conglomerati delle lame” e le “arenarie e sabbie di montescudaio”, e riconosciuta la base di un nuovo ciclo trasgressivo; iv) l’introduzione della denominazione “arenarie e sabbie di montescudaio”, preferita ai termini “calcari sabbiosi di montescudaio” e “calcari di montescudaio” per la rilevante frazione silicoclastica contenuta in questi depositi, ed infine, v) l’introduzione di una nuova unità litostratigrafica “conglomerati di serra all’olio” (ua4) discordante su tutte le altre unità. fatte queste precisazioni, ulteriori considerazioni possono infine essere svolte riguardo all’inquadramento cronostratigrafico. infatti, da questo punto di vista, elementi significativi possono essere derivati dalle “sabbie ed argille ad arctica islandica”. questa unità è stata attribuita al santerniano (sensu ruggieri & sprovieri, 1975) sia sulla base delle associazioni nannofloristiche (zona a gephyrocapsa oceanica-calcidiscus macintyrei, secondo giannelli et al., 1981) sia sulla base della presenza degli ospiti freddi, in particolare arctica islandica, precedentemente descritti, anche se, come già sottolineato, la comparsa di questa forma nel mediterraneo (attualmente vive al di sopra 65° di latitudine con temperature comprese tra 4°c and 13°c) è stata recentemente anticipata al gelasiano (catanzariti et al., 2002), e dunque a circa 2,2 milioni di anni fa. nelle “sabbie ed argille ad arctica islandica” presenti nella bassa val di cecina (ma il dato può sicuramente essere esteso ad altre zone della toscana: cfr. sarti et al., submitted) la presenza di arctica islandica è confinata solo alla parte basale dell’unità (primi 5 m). stratigraficamente più in alto compaiono coralli della specie cladocora caespitosa, taxon caratteristico di acque temperato-calde. questa specie tuttora vivente nel mediterraneo a temperature comprese tra 15°c e 22°c è stata segnalata anche nei sedimenti del pleistocene inferiore della valle di crati in calabria (bernasconi et al., 1997). i ritrovamenti di livelli di notevole spessore di cladocora caespitosa (peirano et al., 2004) associati a strombus bubonius nei sedimenti del tirreniano (sensu ruggieri & sprovieri, 1975) confermano che questo corallo prediligeva temperature anche maggiori rispetto alle odierne. sembrerebbero, dunque, esistere chiare evidenze di fluttuazioni climatiche durante la deposizione di questa unità litostratigrafica. in ogni caso riferendosi alla situazione “toscana”, ed in particolare a quella oggetto di studio, alcune considerazioni ed ipotesi di lavoro di ordine più generale con implicazioni cronostratigrafiche possono comunque essere svolte. nei bacini neogenici della toscana costiera la prima deposizione pleistocenica avverrebbe, secondo i dati di letteratura (dallan & salvatorini, 1967; bossio et al., 1981; rio et al., 1990; boschian et al., 2006), dopo una fase di sollevamento generalizzato invocata per spiegare la sistematica assenza in tutta la toscana di depositi marini riferibili al pliocene superiore. con l’inizio del pleistocene si attiverebbe invece una nuova fase di sprofondamento tettonico. anche se non è ancora chiaro il contributo che separatamente tettonica ed eustatismo quaternari avrebbero giocato nella determinazione della variazione relativa del livello marino, appare poco probabile che una fase trasgressiva si attivi, in un’area peraltro precedentemente soggetta a sollevamento, durante una fase fredda e dunque di caduta eustatica. se a questo aggiungiamo che la presenza di arctica islandica è confinata solo ai primissimi metri dell’unità ed è successivamente sostituita da coralli, indicativi di un clima temperato, sembra più logico supporre che la fase trasgressiva si attivi già durante o all’inizio di una fase di riscaldamento e dunque di rapida risalita eustatica. sebbene ulteriori studi siano necessari per confermare tale ipotesi, ciò implicherebbe un ringiovanimento dell’età di questa unità litostratigrafica. ringraziamenti si ringrazia s. c. vaiani per le discussioni ed i suggerimenti relativi alle associazioni microfaunistiche. si ringraziano inoltre anche i prof. carraro, il prof. ciaranfi ed il prof carrara per la lettura critica del manoscritto e per i loro contributo al miglioramento del lavoro. bibliografia allen j.r.l & banks n.l. (1972) an interpretation and analysis of recumbent-folded deformed crossbedding. sedimentology, 19, pp. 257-283. ambrosetti p., carboni m.g., conti m.a., costantini a., esu d., gandin a., girotti o., lazzarotto a., mazzanti r., nicosia u., parisi g. & sandrelli f. (1979) evoluzione paleogeografica e tettonica nei bacini tosco-umbro-laziali nel pliocene e nel pleistocene inferiore mem. soc. geol. it., 19, pp. 573-580. apat (1992) carta geologica d’italia 1:50.000 – guida al rilevamento quaderni, serie iii, 1/1992. bernasconi m.p., corselli c. & carobene l. (1997) a bank of the scleractinian coral cladocora caespitosa in the pleistocene of the crati valley (calabria, southern italy): growth versus environmental conditions boll. soc. paleontol. ital., 36 (1-2), pp. 53-61. boschian g., bossio a., dall’antonia b., & mazzanti r. (2006) il quaternario della toscana costiera studi costieri, 12, pp. 21-36. bossio a., costantini a., lazzarotto a., liotta d., mazzanti r., mazzei r., salvatorini g. & sandrelli f. (1993) rassegna delle conoscenze sulla stratigrafia del neoautoctono toscano mem. soc. geol. it., 49, pp. 17-98. bossio a., giannelli l., mazzanti r., mazzei r. & salvatorini g. (1981) gli strati alti del messiniano, il passaggio mio-pliocene e la sezione pliopleistocenica di nugola nelle colline a ne dei monti livornesi ix convegno s.p.i., firenzepisa 3-8/9/1981, pp. 55-90. catanzariti r., ottria g. & cerrina feroni a. (2002) tavole stratigrafiche 2 carta geologico strutturale dell’appennino emiliano-romagnolo, scala 1:250000. ed. cnr. selca, firenze. cerrina feroni a., ciampalini a., consoloni i., sarti g. & vaiani s.c. (2005) geological survey and facies analysis of the pleistocene deposits outcropping between riparbella and casale marittimo (lower cecina river valley, tuscany, italy). epitome, geoitalia 2005, spoleto 21-23 settembre 160 g. sarti et al. 2005,vol. 1, pp. 72-73. cerrina feroni a., sarti g., ciampalini a., consoloni i., simonelli e., testa g. & martinelli p. (2003) carta geologica f.294 cecina, sez. 294040, scala 1/10000 regione toscana. costantini a., lazzarotto a., maccantelli m., mazzanti r., sandrelli f., tavarnelli e. & elter f.m. (1993) geologia della provincia di livorno a sud del fiume cecina suppl. n° 2, quad. mus. stor. nat di livorno, 13, pp. 1-164. dallan l. & salvatorini g. (1967) biostratigrafia del pliocene della toscana marittima atti soc. tosc. sci. nat., mem., serie a, 74, pp. 570-578. davies n.s., turner p. & sansom i.j. (2004) soft-sediment deformation structures in the late silurian stubdal formation: the result of seismic triggering – norwegian journal of geology, 85, pp. 233-243. doe t.w. & dott r.h. jr. (1980) genetic significance of deformed cross bedding – with examples from the navajo and weber sandstones of utah – journ. sed. petrology, 50, pp.793-812. giannelli l., mazzanti r., mazzei r., salvatorini g. (1981) i sedimenti del pliocene e del pleistocene inferiore della zona compresa fra riparbella e bibbona (province di pisa e livorno) boll. soc geol. it., 100, pp. 41-56. harms j.c., southward j.b. & walker r.g. (1982) structures and sequences in clastic rocks sepm lecture notes short course, 9. howard j.l. (1993) the statistics of counting clasts in rudites: a review, with examples from the upper palaeogene of southern california, usa sedimentology, 40, pp. 157-174. lazzarotto a. & mazzanti r. (1978) geologia dell’alta val di cecina boll. soc. geol. it., 95 (1976), pp. 1365-1487. malinverno a. & ryan w.b.f. (1986) exstension in the tyrrhenian sea and shortening in the apennines as result of arc migration driven by sinking of the litosphere. tectonics, 5, pp. 227-245. martini p. & sagri m. (1993) tectono-sedimentary characteristic of late-miocene-quaternary extensional basins of the northern apennines, italy. earth sc. rew., 34, pp. 197-233. massari f. & parea g.c. (1988) progradational sequences in a moderateto high-energy, microtidal marine environment sedimentology, 35, pp. 881-913. mazzanti r. (1983) il punto sul quaternario della fascia costiera e dell’arcipelago di toscana boll. soc. geol. it., 102, pp. 419-556. mazzanti r. & sanesi g. (1987) geologia e morfologia della bassa val di cecina suppl. 1 quad. mus. storia nat. di livorno, 7 (1986), pp. 1-27. meletti c., patacca e. & scandone p. (1995) il sistema compressione-distensione in appennino in: bonari g., de vito b., gasparini p., vallario a., (eds.) “cinquanta anni di attività didattica e scientifica del prof. felice ippolito”, liguori ed., napoli, pp. 361-370. moratti g., benvenuti m. & tanini c. (2003) carta geologica f.294 cecina sez. 294080, scala 1/10000 regione toscana. orton g.j. & reading h.g. (1993) variability of deltaic processes in terms of sediment supply, with particular emphasis on grain size sedimentology, 40, pp. 475-512. owen g. (1995) soft-sediment deformation in upper proterozoic torridonian sandstones (applecross formation) at torridon, northwest scotland journ. sed. res., a65, pp. 495-504. patacca e., sartori p., scandone p. (1993) tyrrhenian basin and apennines. kinematic evolution and related dynamic constraints in: recent evolution and seismicity of the mediterranean region, boschi e., mantovani e. and morelli a. (eds.), kluwer academic publishers, dordrecht, pp. 161171. peirano a., morri c., bianchi, c.n., aguirre j., antonioli, f., calzetta g., carobene l., mastronuzzi g. & orrù p. (2004) the mediterranean coral cladocora caespitosa: a proxy for past climate fluctuations? – global and planetary change, 40, pp.195-200. ragaini l. & menesini e. (1997) paleocomunità a molluschi nel pleistocene inferiore della bassa val di cecina (pisa) atti soc. tosc. sci. nat., mem., 104, pp. 67-74. ricci lucchi f. (1978) sedimentologia coop. libr. univers. ed. bol., pp 545. rio d., raffi i. & villa g. (1990) pliocene-pleistocene calcareous nannofossil distribution patterns in the western mediterranean proc.odp sci. results, 107, pp. 513-533. ruggieri g. & sprovieri r. (1975) la definizione dello stratotipo del piano siciliano e le sue conseguenze. riv. min. sic., pp.151-153. ruggieri g. & sprovieri r. (1977) a revision of italian pleistocene stratigraphy. geologica romana, 16, 131-139. salvador a. (1994) international stratigraphic guide. a guide to stratigraphic classification, terminology, and procedure j.u.g.s. and geol. soc. america (eds.), pp. 214. sarti g. (1995) rapporti tra controllo tettonico ed eustatico sulla deposizione miocenica superiore della val di fine (toscana, pisa) studi geologici camerti, vol. spec. 1995/1, pp. 581-592. sarti g. & guidi r. (2005) il potenziale di applicabilità delle unità stratigrafiche a limiti inconformi nella cartografia geologica del quaternario: l’esempio della fascia costiera compresa fra livorno e piombino (toscana, italia) – atti soc. tosc. sci. nat., mem., serie a, 110, pp.73-80. sarti g., testa g. & zanchetta g. (submitted) new stratigraphic insigth from the lower pleistocene cycles of the lower valdarno (tuscany, italy). riv. it. paleont. strat.. sartori r. (1990) evoluzione neogenico-recente del bacino tirrenico e i suoi rapporti con la geologia delle aree circostanti giorn. geol., ser. 3°, 51 (2), pp. 1-39. zuffa g.g.(1980) hybrid arenites: their composition and classification journ. sed. petrology, 50, pp.19-21 161 ms. ricevuto il 19 luglio 2007 testo definitivo ricevuto il 16 ottobre 2007 ms. received: july 19, 2007 final text received: october 16, 2007 i depositi del pleistocene inferiore ... impaginatopelfini ii gghhiiaacccciiaaii ddeellllaa vvaall ssiissssoonnee ((vvaalltteelllliinnaa,, aallppii rreettiicchhee)) ee llaa lloorroo ssttoorriiaa oolloocceenniiccaa mm.. ppeellffiinnii,, gg.. ddiioollaaiiuuttii && cc.. ssmmiirraagglliiaa con la collaborazione di l. montrasi dipartimento di scienze della terra, università di milano riassunto – i ghiacciai della val sissone (valtellina, alpi retiche) e la loro storia olocenica. la ricostruzione dell’evoluzione di alcuni ghiacciai della val sissone (alpi retiche), in particolare quello del disgrazia, ha permesso di fornire un contributo alla conoscenza delle fluttuazioni glaciali alpine con particolare riguardo alla piccola età glaciale ed ai periodi più recenti. attraverso l’utilizzo di diversi metodi di datazione (radiocarbonio, dendrogeomorfologia, documentazione storica), la massima espansione olocenica dell’apparato glaciale del disgrazia dovrebbe collocarsi dopo il xiv secolo, con altre espansioni negli anni ’20-‘30 o negli anni ’50 del xix secolo ed infine negli anni ’20 e ’80 del xx secolo. la tendenza del xx secolo, documentata da misure dirette delle variazioni frontali, è stata in ogni caso nettamente negativa e ha portato la fronte del disgrazia ad arretrare di circa 1 km. abstract – the val sissone glaciers (valtellina, rhetian alps) and their holocenic evolution. the reconstruction of the evolution of some val sissone glaciers (rhetian alps, italy), with particular attention to the disgrazia glacier, gives a contribution to the knowledge of the glacial fluctuations since the little ice age in the italian alps. by utilizing different dating methods (radiocarbon, dendrogeomorphology, historical documentation), it is possible to attribute the maximum glacial advance to a period after the xix century. other glacier expansion phases belong to the ’20 yrs of the xix century and to the ’20 and ’80 years of the xx century. the xx century trend, based on terminus variation direct measurements, was in any case absolutely negative and caused a retreat of the disgrazia glacier snout of about 1 km. parole chiave: variazioni glaciali, olocene, piccola età glaciale, datazioni radiometriche, dendrogeomorfologia key-words: glacier variations, holocene, little ice age, radiocarbon dating, dendrogeomorphology il quaternario italian journal of quaternary sciences 1155(1), 2002, 3-9 11.. iinnttrroodduuzziioonnee l’attuale fase di regresso dei ghiacciai alpini è una realtà ormai acquisita, con ritmi che sembrano incrementarsi nel tempo e con modificazioni indotte nel paesaggio di anno in anno sempre più evidenti ed accentuate. la ricostruzione della storia glaciale passata rappresenta un importante contributo alla conoscenza della dinamica ambientale attuale: infatti, solamente attraverso un’accurata ricostruzione delle vicende, antiche e recenti, che hanno caratterizzato l’evoluzione delle masse glaciali alpine, è possibile riconoscere la sincronia degli eventi anche in regioni lontane, comprendere meglio la dinamica delle risposte glaciali alle variazioni climatiche, cogliere le tendenze in atto e, infine, formulare futuri scenari evolutivi. il lavoro qui presentato si propone come un esempio di indagine, realizzata mediante l’integrazione di diverse discipline e metodi di datazione, finalizzata alla ricostruzione della storia glaciale recente di una valle delle alpi lombarde, la val sissone, situata alla testata della valmalenco, tributaria della valtellina (alpi retiche, italia). nel paesaggio glaciale della val sissone spiccano le forme di accumulo glaciale rappresentate da morene che, come per la maggior parte delle vallate alpine, sono morfologicamente ben delineate, scheletriche, con suolo poco evoluto, prive di vegetazione o poco inerbite, disposte in modo quasi concentrico a formare piccoli anfiteatri. queste forme sono il segno lasciato dai ghiacciai alpini, nel corso degli ultimi 150 anni, nell’ambiente d’alta quota, ghiacciai che hanno manifestato in quest’intervallo di tempo un regresso frontale quasi continuo, interrotto da modeste avanzate. la fase di ritiro, tuttora in corso, ha segnato la conclusione della piccola età glaciale (peg), intervallo temporale durante il quale la maggior parte dei ghiacciai alpini ha manifestato la massima avanzata olocenica. 22.. ii gghhiiaacccciiaaii ddeellllaa vvaall ssiissssoonnee la val sissone è ubicata alla testata della valmalenco, nel gruppo del bernina-disgrazia, a n del m. disgrazia (fig. 1). su di essa si affacciano i ghiacciai disgrazia, sissone e vazzeda ed alcuni apparati minori originatisi negli ultimi decenni in seguito al frazionamento di questi ultimi. al culmine della peg, la testata della valle era occupata da un unico grande ghiacciaio avente un’estensione di circa 803.9 ha; successivamente, la massa glaciale si è frazionata in una serie di individui minori che nel 1992 coprivano complessivamente una superficie di 474.28 ha (folladori, 1997) con una diminuzione del 41% circa rispetto all’estensione assunta durante la peg e con un ritiro lineare di oltre un chilometro e mezzo per il solo ghiacciaio del disgrazia. quest’ultimo rappresenta l’apparato glaciale più esteso della zona; si tratta di un ghiacciaio di circo-pendio esposto a nord che occupa una superficie di 335 ha, con lunghezza massima di 2400 m e larghezza pari a 2100 m (servizio glaciologico lombardo, 1992). gli altri corpi glaciali della zona sono tutti apparati di circo di varie dimensioni; i ghiacciai di punta baroni e del passo di chiareggio sono di limitata estensione, rispettivamente di 10 e 23 ha, mentre il ghiacciaio sissone con 80,5 ha di superficie è decisamente più ampio. parzialmente unito al sissone è il ghiacciaio di rosso sud-est, con estensione di 12 ha. completano il quadro del glacialismo locale i ghiacciai cima di rosso est (19 ha) e vazzeda (ubicato nella vicina val muretto). 33.. mmeettooddoo ddii llaavvoorroo e’ stato effettuato sul terreno un rilevamento geomorfologico di dettaglio, affiancato da fotointerpretazione sui fotogrammi 22 e 23 della strisciata 67 (volo del 18-08-1982 dell’aeronautica militare) alla scala 1:30.000 e su alcuni ingrandimenti alla scala 1:5000. tale lavoro ha portato alla realizzazione di una carta geomorfologica alla scala 1:10.000. per gli argini morenici riconosciuti sul terreno e cartografati sono state proposte datazioni basate su dendrocronologia e radiocarbonio (applicato a suoli e resti legnosi sepolti) e sull’analisi di documenti storici, cartografici ed iconografici. per quanto riguarda questi ultimi è appena il caso di ricordare come il loro utilizzo a fini geomorfologici fornisca dati attendibili solo dopo la metà del 1800. decisamente più quantitativi, sebbene nel caso in oggetto utilizzabili con molte cautele, sono i metodi dendrocronologici e radiometrici, sui cui principi e problemi di utilizzazione in campo geomorfologico-glaciale si rimanda alla letteratura (giordano, 1971; fritts, 1976; pelfini, 1987; mortara et al., 1992; schweingruber, 1996; pelfini & orombelli, 1997; pelfini 1999). per quanto riguarda la storia glaciale del xx secolo si sono utilizzati soprattutto i dati delle variazioni frontali rilevati annualmente dagli operatori glaciologici. 44.. llaa ssttoorriiaa ggllaacciiaallee oolloocceenniiccaa ddeellllaa vvaall ssiissssoonnee ssiinnoo aall xxiixx sseeccoolloo la storia glaciale della val sissone è stata studiata analizzando in particolare l’apparato morenico frontale del ghiacciaio del disgrazia (fig. 2), la cui lingua raccoglieva durante la peg e ancora fino al 1910 tutte le masse glaciali provenienti dalla testata della valle. le morene più avanzate deposte da questo apparato glaciale sono situate a circa 1780 m di quota sulla destra idrografica del torrente sissone. si tratta di tre argini latero-frontali ben conservati (1, 2 e 3 in fig. 2); sulla sinistra, correlabile dal punto di vista geometrico con la n. 3, è invece riconoscibile un unico breve argine (4 in fig. 2), che è possibile raccordare con due tronconi (5 e 6) in posizione nettamente laterale. la morena più esterna (n. 1), che testimonia la massima avanzata olocenica, presenta uno spessore modesto (si alza di 2-3 metri rispetto alla topografia circostante) e risulta parzialmente coperta nel suo settore laterale da detrito di versante. durante la fase di deposizione della morena, il ghiacciaio ha sigillato il suolo sottostante; al disotto dell’orizzonte organico sepolto si è conservata una porzione di tronco sepolto da un grosso masso appartenente alla morena frontale più esterna. il peso del masso ha deformato l’intera successione degli strati che tendono ad immergere sotto di esso. la deformazione degli strati documenta come la successione che costituisce la sezione fosse già presente prima della messa in posto della morena. la fig. 3 riporta la sezione e lo schema dei rapporti stratigrafici. la lontananza dal versante e l’ubicazione del masso entro la morena, consentono di escludere la messa in posto del masso da parte di processi di versante. l’età 14c ottenuta presso il “geochron laboratories”, massachusset) (campione 99406295 gx 22254) è risultata pari a 600 ± 75 anni b.p. la data è stata sottoposta a calibrazione mediante il programma oxcal (stuiver & reimer, 1993) e si è ottenuto come intervallo di maggior probabilità il xiv secolo o, al limite, il periodo fra il 1280 e il 1440 (anni calendario). poiché il reperto non è in posizione primaria, la sua età è sicuramente e in ogni caso un termine post quem per la messa in posto della morena; questa è dunque avvenuta in un periodo compreso tra il 12801440 ad e l’età della morena immediatamente più interna (n. 2 in fig. 2). il tempo necessario al seppellimento del reperto ligneo e alla formazione del suolo al di sopra delle sabbie che lo inglobano, induce a ritenere che la fase di recrudescenza climatica che ha determinato l’espansione del ghiacciaio del disgrazia si collochi nella piccola età glaciale, forse in una delle sue fasi più antiche. per la datazione della morena n. 2 e delle altre morene più interne e quindi per la ricostruzione della storia glaciale della peg si è provato ad utilizzare metodi lichenometrici e dendrocronologici. 4 pelfini-diolaiuti-smiraglia fig. 1 localizzazione della val sissone. location of the val sissone nell’intera val sissone è stata effettuata una serie di misure lichenometriche. nonostante la relativa facile reperibilità dei licheni, non sono stati trovati talli cresciuti su superfici di esposizione nota. e’ risultato pertanto impossibile costruire una curva di crescita locale sia per il gruppo rhizocarpon geographicum, sia per l’aspicilia cinerea e utilizzare la lichenometria per datazioni assolute. per la morena n. 3 si è proceduto ad indagini dendrocronologiche. similmente alla morena n. 2, questo argine detritico è ben conservato e si snoda lungo il fianco destro della val sissone. le analisi dendrocronologiche non risolvono tuttavia il problema della sua datazione. le misure effettuate su alcuni larici che crescono sull’area prativa immediatamente a monte della morena indicano che il più vecchio di questi presenta 104 anelli di accrescimento; gli estremi cronologici della carota prelevata sono quindi 1892-1995. aggiungendo a questi gli anni necessari a raggiungere il metro di altezza (altezza a cui vengono prelevati i campioni e pari a circa 15-20 anni di età dell’esemplare) e quelli stimati per la colonizzazione (15-20 anni), la pianta potrebbe presentare circa 140 anelli. ciò potrebbe riportare alla metà del xix secolo (1852). va ricordato che alcuni autori aggiungono anche un numero di anelli maggiore. deline (1999) per esempio, in val veny (ao) aggiunge sino a 65-70 anelli per ottenere l’età minima di messa in posto delle morene. la scelta di aggiungere una quarantina di anelli al massimo deriva dalle esperienze fatte in alcune valli delle alpi centrali, per le quali questo valore sembra più ragionevole. utilizzando i valori più elevati proposti da altri autori, si potrebbe ipotizzare un’avanzata intorno al 1830, mentre mantenendo i valori proposti in questo lavoro l’area sembra essersi deglaciata e resa libera per la colonizzazione vegetale almeno a partire dalla metà del xix secolo. la localizzazione del limite inferiore del ghiacciaio durante l’ultimo secolo della peg è confermata dalle carte topografiche del xix secolo, pur tenendo conto della loro non totale affidabilità (specialmente per quelle della prima metà del secolo). la carta dello stato maggiore austriaco del 1833 alla scala 1:86.400, ad esempio, mostra la fronte del ghiacciaio a circa 18101850 m di quota, poco a monte delle morene sopra descritte. la carta topografica svizzera alla scala 1:100.000 rilevata tra il 1854 e il 1871 colloca la fronte del ghiacciaio ad una quota di circa 1900 m, mentre nel 1890 la carta dell’istituto geografico militare (igm) alla scala 1:50.000, che introduce le curve di livello e per la 5i ghiacciai della val sissone ... fig. 2 le morene della val sissone. i numeri indicano i depositi glaciali descritti nel testo. the val sissone moraines. the glacial deposits described in the text are indicated by numbers. fig. 3 profilo del suolo aperto entro la morena n. 1 di figura 2 a quota 1780 m. dall’alto i livelli rappresentano: 0-8 cm orizzonte organico attuale con superficie a prato; 8-14 cm orizzonte organico nero, a tessitura limosa, ricco di frammenti di legno e radici; 14-18 cm sabbia grigio-bruna media, 18-34 cm sabbia media limosa, di colore bruno con venuta d’acqua, 34-40 cm sabbia contenente il reperto ligneo. soil profile of the n° 1 moraine (fig.2), 1780 m a.s.l. from the top: 0-8 cm, present organic level with meadow; 8-14 cm black organic silt level, with wood and root fragments; 1418 cm grey-brown medium sand; 18-34 cm brown medium sand with silt; 34-40 cm sand with wood fragment.. prima volta le quote delle fronti glaciali, indica la fronte a 1945 m. a partire dalla fine del xix secolo, la ricostruzione della storia glaciale si arricchisce di particolari in quanto sono disponibili testimonianze dirette, cartografia aggiornata e rilevata in modo più preciso, relazioni annuali da parte degli osservatori della commissione glaciologica del club alpino italiano, resoconti di ascensioni alpinistiche, fotografie (quali ad esempio quelle di v. sella relative al ghiacciai del disgrazia e vazzeda dal 1896), tutti documenti che hanno consentito una ricostruzione più precisa della storia glaciale recente di questa valle. le fronti glaciali della val sissone sono state visitate con intenti scientifici per la prima volta alla fine del xix secolo da l. marson, che prosegue le osservazioni della lingua del disgrazia sissone per cinque annate consecutive; poi, dopo un periodo di stasi, i rilievi ricominciano a cura degli operatori del comitato glaciologico italiano e proseguono con qualche lacuna fino ad oggi. nel 1893-95 secondo il racconto di alcuni pastori, citato da marson nella sua relazione sull’osservazione delle fronti glaciali della val sissone compiuta nel 1896 (nell’occasione lo studioso pose presso la fronte i primi segnali di misura), il ghiacciaio si trovava in fase di progresso, tanto da aver reso inaccessibili alcune rupi e prati che si potevano raggiungere fino a pochi anni prima (marson, 1897); non sono state però ritrovate evidenze geomorfologiche di tale fase di progresso. secondo marson (1897), che prosegue le osservazioni glaciologiche fino ai primi anni del 1900, nel 1896 la fronte del disgrazia-sissone giungeva a 1945 m di quota e la lunghezza dell’apparato glaciale, calcolata dal passo di s. martino (oggi chiamato passo di mello) fino alla fronte era di 2359 m. tra il 1896 ed il 1897 lo stesso osservatore misura un arretramento frontale pari a 7,8 m (marson, 1898), mentre dal 1897 al 1898 registra un’avanzata di 3,7 m (marson, 1899). 55.. ssttoorriiaa rreecceennttee ddeell ggllaacciiaalliissmmoo ddeellllaa vvaall ssiissssoonnee ((xxxx sseeccoolloo)) la fonte principale della storia glaciale della val sissone nel xx secolo è rappresentata dalle relazioni annuali degli operatori del cgi, raccolte nei bollett ini del comitato glaciologico italiano dal 1913 al 1977 e in geografia fisica e dinamica quaternaria dal 1978 ad oggi. con questo materiale è stato possibile tracciare le curve tempo-distanza delle variazioni frontali dei ghiacciai in oggetto e in particolare di quello del disgrazia, che ben testimonia quantitativamente l’evoluzione nel xx secolo del glacialismo della val sissone (figg. 4 e 5). l’inizio del xx secolo è caratterizzato da un fase di regresso; nel 1907, quando marson ritorna a visitare la valle, la lingua del ghiacciaio è infatti arretrata di 83,35 m rispetto alla posizione registrata nel 1899. dopo marson i rilievi sul ghiacciaio del sissone vengono condotti da d. sangiorgi a partire dal 1910. con la prima relazione (sangiorgi, 1912) l’autore sembra suggerire l’avvenuta separazione tra i due apparati principali; in effetti, a partire da quell’anno la lingua glaciale che percorre la val sissone sarà denominata solo “del disgrazia”. dal 1911 al 1916 le sue relazioni testimoniano un continuo ed intenso ritiro che termina solo nel 1917 con un avanzamento frontale di 22 m (sangiorgi, 1919). da allora inizia un nuovo periodo di progresso frontale, in fase con quanto registrato dalla maggior parte dei ghiacciai alpini per i quali si disponga di dati relativi alle variazioni frontali (vivian, 1975; reynaud, 1983; cerutti, 1995). l’avanzata è rapida e nel 1926 la fronte del ghiacciaio è scesa fino a 1970 m di quota. da quell’anno riprende una tendenza al regresso che porta, nel 1928, il ghiacciaio a ritirarsi di ben 25 m (sangiorgi, 1929). nel 1928 la val sissone ed i l ghiacciaio disgrazia vengono visitati e studiati anche da g. nangeroni. da allora continua inesorabile il ritiro e la fronte del ghiacciaio nel 1949 arriva a 2020 m di quota, dopo il distacco di una placca di ghiaccio che porta l’apparato ad isolarsi sopra un gradino roccioso e abbandona a valle la porzione crollata ormai separata dal resto del ghiacciaio, coperta di morenico, a formare un cospicuo lembo di ghiaccio morto. nel settembre 1950 l’alta val sissone viene profondamente modificata da “una grande improvvisa alluvione ed un imponente smottamento di parte della morena laterale sinistra del ghiacciaio disgrazia” (nangeroni, 1951). questi eventi rimodellano intensamente l’area proglaciale e parzialmente 6 pelfini-diolaiuti-smiraglia fig. 4 curva delle variazioni frontali cumulate del ghiacciaio disgrazia dal 1895 al 1999 costruita sulla base dei dati raccolti dagli operatori del comitato glaciologico italiano cumulative frontal variations of disgrazia glacier from 1895 to 1999 by italian glaciological committee data. 7i ghiacciai della val sissone ... fig. 5 a) il ghiacciaio disgrazia in una fotografia dell’inizio del xx secolo di autore sconosciuto; b) lo stesso ghiacciaio nel 1997 in una fotografia di l. montrasi. a) disgrazia glacier xxth century beginning (photograph by unknown author). b) same glacier in 1997 (by l. montrasi photograph). a) b) 8 pelfini-diolaiuti-smiraglia distruggono ed occultano i depositi morenici del fondovalle. le relazioni degli anni successivi descrivono una fronte arroccata su un gradino roccioso in continuo ritiro ed una placca di ghiaccio relitto, in fusione, destinata a scomparire. delle morene della valle non si parla più fino al 1954 quando a. riva, nella sua annuale relazione sottolinea la completa demolizione dell’apparato morenico del vecchio ghiacciaio (riva, 1955). fino al 1957 le osservazioni annuali al ghiacciaio vengono condotte con regolarità ed in quell’anno la fronte della placca di ghiaccio morto viene registrata a 2110 m di quota; poi per più di un ventennio la val sissone viene dimenticata, se si fa eccezione per il rilievo condotto da c. corona nel 1974. negli anni ’80 riprendono le osservazioni e le misurazioni frontali del ghiacciaio disgrazia. l’operatore che lo visita (catasta, 1981) osserva la fronte a 2400 m con il ghiacciaio in fase di netto progresso che sembra unito al ghiacciaio punta baroni che si trova alla sua sinistra. il progresso frontale continua per qualche anno e nel 1981 catasta (1982) rileva che la lingua di sinistra, avanzando verso il fondovalle, sta formando un arco morenico di spinta, mentre la fronte vera e propria, avanzando, è andata unendosi al ghiaccio crollato dalle regioni superiori a formare ghiaccio di rimpasto. nel 1984 la fronte è scesa fino a 2030 m di quota (considerando per fronte la porzione di ghiaccio di rimpasto o rigenerato ormai conglobato con la lingua vera e propria) ed è abbondantemente coperta di materiale morenico grossolano (catasta, 1986). la fase positiva è ancora in atto nel 1988, anche se il progresso non risulta quantificabile, poiché i segnali sono stati spazzati via dall’alluvione che ha colpito la valtellina nel 1987. si tratta dell’ultimo periodo di avanzata glaciale, in fase con quella che ha caratterizzato la maggior parte degli apparati alpini europei ed extraeuropei (wood, 1988; zanon, 1991; cerutti, 1992; pelfini & smiraglia, 1992) in conseguenza della recrudescenza climatica globale nota come “episodio freddo” (pinna, 1996). gli indizi di regresso si manifestano a partire dal 1990 nelle colate laterali, mentre la colata principale, protetta da una spessa coltre di morenico, continua una lieve avanzata. la tendenza al ritiro si afferma negli anni successivi e porta la fronte a retrocedere, fino ad un massiccio distacco di una porzione terminale nel 1995, che lascia una fronte sospesa su ripido pendio roccioso a 2250 m di quota ed una porzione di ghiaccio isolato, “morto”, coperto da morenico nel fondovalle (mariani, 1997). da allora il ghiacciaio ha continuato a ritirarsi per un arretramento lineare valutabile in oltre 450 m che ha portato la fronte sino a quota 2370 m. dinamica glaciale simile ha manifestato nel tempo il ghiacciaio del sissone, monitorato anch’esso a partire dal 1911 da sangiorgi ed attualmente in fase di marcato regresso. 66.. ccoonncclluussiioonnii l’utilizzo di metodologie integrate (rilievi geomorfologici, dendrocronologia, documentazione storica) ha permesso di individuare numerose fasi di espansione olocenica del ghiacciaio del disgrazia e di proporre, seppur con incertezze, alcune date di deposizione delle morene. ad esempio, la massima estensione, testimoniata da evidenti morene frontali, potrebbe non essere stata raggiunta al culmine della peg, che generalmente si colloca intorno al 1820-25 (ad esempio per la mer de glace), bensì dopo il xiv secolo. alle ulteriori fasi di espansione della peg (primi decenni oppure metà del xix secolo), segue una fase di intenso regresso quasi continuo, brevemente interrotto dalle due limitate fasi di avanzata degli anni ’20 e degli anni ’80 del xx secolo. per quanto riguarda quest’ultimo secolo, anche se le morfologie non si sono perfettamente conservate e solo le più recenti sono rimaste a testimonianza della dinamica glaciale, i documenti storici e le misure dirette condotte per oltre cento anni, hanno permesso di ricostruire in misura attendibile la storia glaciale della valle e di verificare che i ghiacciai della val sissone hanno manifestato una risposta all’effetto forzante del clima in fase con altri apparati glaciali alpini. lavoro realizzato nell’ambito del cofinanziamento murst 1999, progetto di ricerca: “ghiacciai alpini e variazioni ambientali”. responsabile nazionale prof. a. biancotti, responsabile locale prof. a. bini. si precisa che il lavoro è stato realizzato e scritto congiuntamente dai tre autori. bbiibblliiooggrraaffiiaa catasta g. (1981) relazione della campagna glaciologica 1980. geogr. fis. dinam. quat., 4 (2) 160-161. catasta g. (1982) relazione della campagna glaciologica 1981. geogr. fis. dinam. quat., 5 (2) 387-389. catasta g. (1986) relazione della campagna glaciologica 1984. geogr. fis. dinam. quat., 9 (1) 25. cerutti a.v. (1992) l’espansione dei ghiacciai del monte bianco fra il 1962 e il 1989. geogr. fis. dinam. quat., 15, 75-84. cerutti a.v. (1995) variazioni dei ghiacciai del monte bianco in epoca storica. in: “archivi glaciali. le variazioni cl imatiche ed i ghiacciai.” att i dell’incontro di courmayeur, 2-3 settembre 1995, 9-28. corona c. (1974) relazione della campagna glaciologica 1974. boll. com. glac. it., serie ii, 22, 262-263. deline p. (1999) la mise en places de l’amphithèatre morainique du miage (val veny, val d’aoste). geomorphologie. folladori l. (1997) “global change: studio delle variazioni climatiche e ambientali oloceniche nelle alpi lombarde, mediante indagini geomorfologiche e glaciologiche”. in: collana ricerca e risultati, fondazione lombardia per l’ambiente, 30 pp.100123 fritts h.c. (1976) tree rings climate. academy press, london, 567 pp. giordano g. (1971) tecnologia del legno 1° la materia prima. 1986 pp, u.t.e.t., torino. mariani v. (1997) relazione della campagna glaciologica 1996. geogr. fis. dinam. quat., 20 (2), 391-392. 9i ghiacciai della val sissone ... marson l. (1897) sui ghiacciai del massiccio del monte disgrazia o pizzo bello. memorie soc. geogr. it., 7 (1), 63-68. marson l. (1898) sui ghiacciai del massiccio del monte disgrazia e bernina. memorie soc. geogr. it., 8 (2), 168-170. marson l. (1899) sui ghiacciai del massiccio del monte disgrazia e bernina. memorie soc. geogr. it., 9, 170-173. mortara g., orombelli g., pelfini m. & tellini c. (1992) suoli e suoli sepolti olocenici per la datazione di eventi geomorfologici in ambiente alpino: alcuni esempi tratti da indagini preliminari in val d'aosta. ii quaternario 5 (2),135-146. nangeroni g. (1951) la frana di val sissone (15 settembre 1950). natura, 42, 11-17. pelfini m. & orombelli g. (1997) variazioni recenti dell’ambiente alpino registrate nelle serie di anelli di accrescimento delle conifere. applicazioni della dendrogeomorfologia. acqua e aria, 6, 103-110 pelfini m. & smiraglia c. (1992) recent fluctuations of glaciers in valtellina (italian alps) and climatic variations. journ. glac., 38, 309-313. pelfini m. (1987) contributo alla conoscenza delle fluttuazioni oloceniche del ghiacciaio dei forni. natura bresciana ann. mus. civ. sc. nat., brescia, 24, 237-257. pelfini m. (1999) dendrogeomorphological study of glacier fluctuations in the italian alps during the little ice age. annals of glaciology 28, 123 – 128. pinna m. (1996) le variazioni recenti del clima. angeli, milano. reynaud l. (1983) european glaciological data and their relation with the climate. in “new perspectives in climate modelling”, edited by a.l. berger and c. nicolis, elsevier science publishers b.v., amsterdam riva a. (1955) relazione della campagna glaciologica 1954. boll. com. glac. it., serie ii, 6, 188-191. sangiorgi d. (1912) osservazioni sui ghiacciai di valmalenco. rivista cai, 2, 43-45. sangiorgi d. (1919) relazione preliminare sui ghiacciai della valtellina. boll. com. glac. it, 3, 18. sangiorgi d. (1929) relazione della campagna glaciologica 1928. boll. com. glac. it, 9, 276-279. schweingruber f.h. (1996) tree rings and environment dendroecology. haupt verlag. servizio glaciologico lombardo (1992) ghiacciai in lombardia. edizioni bolis, bergamo. stuiver m. & reimer p.j. (1993) radiocarbon, 35, 215230. vivian r. (1975) les glaciers des alpes occidentales. grenoble, allier wood f. (1988) global alpine glacier trends 1960s to 1980s. arct. alp. res., 20, 4, 404-413. zanon g. (1991) vent’anni di progresso dei ghiacciai 1965-1985. atti del convegno “le variazioni climatiche recenti (1800-1990) e le prospettive per il xxi secolo”, roma, 5-6 aprile 1990, mem. soc. geogr. it., 46, 153-165. ms. ricevuto il 28 dicembre 2000 testo definitivo ricevuto il 24 luglio 2001 ms. received: december 28, 2000 final text received: july 24, 2001 processi di approfondimento dell'erosione in alveo ed effetti dell'inquinamento nei fiumi delle marche centro-meridionali (italia centrale) piero farabollini, domenico aringoli, bernardino gentili, marco materazzi & gilberto pambianchi dipartimento di scienze della terra università di camerino e-mail: piero.farabollini@unicam.it riassunto: farabollini p. et al., processi di approfondimento dell'erosione in alveo ed effetti dell'inquinamento nei fiumi delle marche centro-meridionali (italia centrale) (it issn 0394-3356 2008). recenti numerosi studi geomorfologici sulla dinamica fluviale hanno permesso di verificare intensi e veloci processi di approfondimento lineare in alveo su numerosi fiumi italiani interpretandoli come il risultato dell'intervento antropico: il loro effetto morfologico è comparabile agli effetti prodotti dalle variazioni climatiche quaternarie. l'attribuzione di tali fenomeni all'influenza più o meno diretta delle diverse attività antropiche sulla dinamica ambientale dimostra che i sistemi idrografici sono tra le componenti del paesaggio fisico che più rapidamente reagiscono ai cambiamenti ambientali. il presente lavoro, che ha l'obiettivo di approfondire la conoscenza su tale argomento, risulta da una serie di dettagliati rilievi geomorfologici, coadiuvati da analisi geotecniche, che hanno riguardato nel corso dell'ultimo decennio alcuni fiumi delle marche (versante adriatico dell'italia centrale; marche centro-meridionali). nonostante il breve periodo di osservazione, è stato possibile osservare considerevoli variazioni nella geometria degli alvei fluviali, le quali possono essere attribuite senza dubbio alle attività antropiche. recenti indagini di dettaglio su alcuni corsi d'acqua hanno evidenziato intensi processi erosivi soprattutto a valle di alcuni depuratori, dove l'erosione sembra essere innescata o accelerata dalle acque inquinate che causano la rottura di particolari legami ionici, in particolar modo nei minerali argillosi del substrato. un ulteriore contributo nei riguardi dell'approfondimento della rete idrografica, il cui tasso ha raggiunto, in quasi tutti i fiumi considerati nel presente lavoro ma la situazione è facilmente riscontrabile nella maggior parte dei fiumi marchigiani anche diversi metri in alcuni anni, è dato dall'intensa e sempre crescente occupazione delle piane alluvionali da parte dell'uomo. in tale caso, deve essere evidenziato come spesso il drenaggio viene ostacolato soprattutto al raccordo tra reticolo idrografico principale (fondovalle) e secondario (versanti). altri processi erosivi hanno luogo anche a valle di confluenze con canali artificiali (privati e pubblici), dove si registra un incremento della portata e del carico solido che favorisce un'intensa erosione laterale e l'approfondimento dell'alveo. viene, infine, anche valutato come, lungo le pianure alluvionali, il notevole emungimento di acque (che nel periodo estivo avviene senza un'adeguata ricarica dell'acquifero), possa produrre vistosi fenomeni di crepacciatura nel suolo, i quali predispongono il terreno ad ulteriori fenomeni erosivi. abstract: farabollini p. et al., deepening erosional fluvial processes and effects of water pollution in the middle-southern marchean rivers (central italy) (it issn 0394-3356 2008). many modern geomorphological studies on fluvial dynamics carried out on some italian rivers highlighted that intense and showy erosion processes affect them and interpreted this mostly as the result of human intervention: their morphological effects, notwithstanding the short duration of processes, are somehow comparable with those produced by pleistocene climatic variations. the attribution of such phenomena to more or less direct influence of different anthropic activities on fluvial dynamics demonstrates that hydrographic systems are among the components of the physical environment that reacts more quickly to environmental changes. this paper aims at deepening our understanding of the topic and derives from detailed geomorphological surveys, sided by geotechnical analyses, carried out during the last decade along the reaches of the marchean rivers (central-southern marche, adriatic side of central italy). notwithstanding the short duration of observation, it was possible to observe relevant geometric variations of river beds that can be unquestionably attributed to human activities. recent detailed investigations on some streams highlighted the activity of intense erosional processes, mostly valleyward of some purifiers. there, erosion is probably triggered or accelerated by water pollution that causes the breaking of particular ionic links, especially in clay minerals. another contribution to stream deepening, whose rate sometimes reaches some meters in few years, is given by the strong and ever increasing occupation of alluvial plains for human purposes. in such situation, it is to be evidenced that drainage is often obstacled in links between main and secondary hydrographic network. another erosional process takes place downstream of confluences of artificial water channels (private or public), where discharge and solid load increase, resulting in more intense lateral erosion and downcutting. finally, the notable extraction of water from alluvial plains is studied since, mainly during summer, it is not balanced by an adequate recharge, thus producing important cracking phenomena and, subsequently, leading to further fluvial deepening parole chiave: processi erosivi; composizione mineralogica argillosa; antropizzazione; potenza e chienti; italia centrale. keywords: erosional processes, clay mineralogical composition, anthropization, potenza and chienti rivers, central italy. il quaternario italian journal of quaternary sciences 21(1b), 2008 317-330 1. introduzione negli ultimi decenni, numerosi studi riguardanti gli aspetti morfodinamici dei sistemi fluviali italiani hanno messo in chiara evidenza come l'estrazione di inerti, praticata direttamente all'interno degli alvei fluviali o nelle piane limitrofe, sia stata la principale causa di attivazione di intensi e vistosi processi di erosione lineare, riconosciuti nella quasi totalità dei corsi d'acqua nella seconda metà del xx secolo. accanto all'attività estrattiva è stato evidenziato come anche lo sbarramento fluviale per la creazione di invasi artificiali abbia innescato intensi processi erosivi, in quanto gli stessi invasi hanno funzionato da trappole sedimentarie. ad essi si sono 318 p. farabollini et al. associati effetti negativi anche sulle linee di riva delle corrispondenti foci, caratterizzate da generali fenomeni di arretramento. tali intense dinamiche sono del tutto comparabili con quelle rilevate in analoghi contesti geomorfologici e socio-economici del bacino mediterraneo come di altre aree del globo (ve g g i a n i, 1963; ro v e r i, 1964; pe l l e g r i n i & za r o t t i, 1975; ta v a g l i n i, 1975; ra g l i o n e & ro d o l f i, 1977; co c c o et al., 1978; pa r e a, 1978; pe t t s, 1979; pe l l e g r i n i et al., 1980; ma r a g a & mortara, 1981; barnard & melhorn, 1982; kellerhals, 1982; winkley, 1982; conti et al., 1983; williams & wolm a n, 1984; buccolini & ge n t i l i, 1986; an d r e w s, 1986; gentili & pambianchi, 1987 cum bib.; bisci et al., 1992; ca n u t i et al., 1992; la m b e r t i, 1993; ce n c e t t i et al. , 1994a e b; du t t o & ma r a g a, 1994; kl i n g e m a n et al. , 1994 cum bib.; sa b a t o, 1994; wi l s o n & tu r n i p s e e d, 1994; co l t o r t i et al., 1995; la j e c z a k, 1995; ri n a l d i & ro d o l f i, 1995; pe t i t et al., 1996; bi l l i & ri n a l d i , 1 9 9 7 ; coltorti, 1997; rinaldi & simon, 1998; sear & archer, 1998; surian, 1999; farabollini et al., 2000; decroix & ga u t i e r, 2002; ma r c h e t t i, 2002; ar i n g o l i et al., 2003; surian & rinaldi, 2003 cum bib.; coltorti & farabollini, 2004; brunelli & fa r a b o l l i n i, 2005 cum bib.; ho o k e, 2006 cum bib.; simon & rinaldi, 2006; wohl, 2006 cum bib.) la tematica di ricerca è stata sviluppata anche nei corsi d'acqua del settore marchigiano dell'italia centrale adriatica, in particolare nei loro tratti medio-bassi, con analisi geomorfologiche di dettaglio, ripetute su periodi diversi, i cui principali risultati ottenuti sono compendiati nella tabella 1. con la presente nota si intende portare un ulteriore contributo alla conoscenza dei processi di erosione in alveo, prendendo in considerazione le più recenti modificazioni morfologiche rilevate sulle sponde di tre dei principali sistemi fluviali dell'area (potenza, chienti e tenna fig. 1), sempre connesse ad attività antropiche sviluppate in alveo, anche se diverse da quelle citate. in particolare, viene analizzato il ruolo svolto dalle caratteristiche chimiche delle acque sull'erodibilità del substrato argilloso, visto che quest'ultimo costituisce attualmente, per effetto dello smantellamento dei depositi alluvionali, il t a l w e g della maggior parte dei tratti mediobassi dei citati fiumi. i dati ottenuti, vengono illustrati ed interpretati facendo anche riferimento alla specifica, non copiosa, letteratura scientifica internazionale (ar u n a l a nd a n et al., 1973; os m a n & th o r n e, 1988; es p o s i t o & di og e n e, 2002; ar i n g o l i et al., 2003; ma t t i a s, 2004). 2. lineamenti fisiografici e climatici e impatto antropico nei bacini imbriferi marchigiani l'area di studio è localizzata nelle marche centromeridionali ed in particolare comprende diversi siti campione appartenenti a limitati tratti dei bacini idrografici dei fiumi potenza, chienti e tenna. l'assetto geomorfologico complessivo dei bacini ed i loro fondamentali parametri morfometrici (tab. 2) sono condizionati, per lo più, dal contesto geologico (ce n t a m o r e & deiana, 1986) e dal gradiente topografico regionale. su tale base è possibile suddividere il territorio regionale in tre settori distinti (fig.1). il primo settore è inciso nella fascia montana corrispondente alla dorsale appenninica; la morfologia del paesaggio fisico è strettamente connessa alla presenza dei litotipi più competenti della sequenza umbrom a r c h i g i a n a, costituiti da calcari, calcari marnosi e marne (lias oligocene), che affiorano in due ampi ed estesi anticlinori (la dorsale umbro-marchigiana s.s., occidentale e marchigiana, orientale); essi, intensamente fratturati, piegati e sovrascorsi, si fondono verso sud nel “massiccio” dei monti sibillini. l'assetto morfologico è caratterizzato da valli fluviali ad andamento generalmente lineare, spesso incassate in gole; il canale di magra dei fiumi è unico, largo pochi metri, inciso a tratti nel substrato roccioso ed a tratti nei depositi alluvionali di esiguo spessore. i versanti sono occupati prevalentemente dal bosco e presentano a luoghi notevoli accumuli di detrito stratificato. a causa della forte pendenza, i suoli sono poco sviluppati nelle aree boschive, mentre diminuiscono ulteriormente di spessore nelle zone di recente abbandono o dove viene praticata l'attività tabella 1 escavazione in alveo nei fiumi marchigiani e relativi effetti indotti sulle aste e sulle foci fluviali (modificato da gentili & pambianchi, 1987 e coltorti et al., 1995). quarrying activity and related effects on fluvial axes and mouths along the marchean rivers (modified from gentili & pambianchi, 1987 and coltorti et al., 1995) durata escavazione quantità di approfondimento arretramento (-) della bacino area in alveo tra il 1960 e materiale lineare medio linea di riva in idrografico (km2) il 1975 circa escavato dell'alveo corrispondenza della (anni) (m3 x 106) (m) foce (m) foglia 701 10 2 3.0-4.0 27 metauro 1405 10 3 6.0-7.0 75 cesano 413 3 0.2 2.0-2.5 155 misa 376 5 0.02 1.0 5 esino 1148 6 2 3.0 190 musone 642 10 0.5 3.0-3.5 50 potenza 773 7 1.4 3.0 102 chienti 1294 10 2.7 4.0 240 tenna 484 7 0.8 5.0 130 aso 280 8 0.4 2.5-3.0 120 tronto 1192 7 0.8 3.5 465 agro-pastorale. la permeabilità è elevata, con valori di infiltrazione efficace medi di circa 550 mm/anno rapportati a precipitazioni medie dell'ordine di 1.000-1.100 mm/anno. il secondo settore è scolpito nella fascia pedemontana, data da sedimenti miocenici, costituiti da alternanze di torbiditi arenacee, arenaceo-pelitiche e pelitico-arenacee alle quali si intercalano, in subordine, gessi e torbiditi carbonato-silicatiche (miocene mediosuperiore); l'assetto strutturale, piuttosto complesso, è caratterizzato da pieghe, faglie e sovrascorrimenti, per lo più sepolti. le incisioni vallive del terzo settore, in cui ricadono i siti oggetto del presente studio, si sono realizzate 319processi di approfondimento dell’erosione ... nei sedimenti marini del ciclo plio-pleistocenico della fascia peri-adriatica, in cui dominano le argille, entro le quali si alternano a vari livelli stratigrafici corpi arenaci, conglomeratici e sabbioso-conglomeratici, disposti regolarmente a monoclinale con vergenza circa orientale. i corsi d'acqua principali, cataclinali, incidono i litotipi appena descritti e disarticolano il rilievo monoclinale in una successione di rilevi alto-collinari e collinari dalla tipica morfologia a cuesta, con le basi rivolte ad oriente e bordate sui quadranti occidentali da elevate scarpate strutturali scolpite nelle unità litoidi più rigide. le estese morfostrutture costiere sono limitate da falesie antiche, per lo più scolpite nei potenti corpi conglomeratici, separate dal mare da coste sabbiose di ampiezza variafig. 1 schema delle unità fisiografiche delle marche (da bisci et al., 1991, modificata). schematic marchean physiographic units (from bisci et al., 1991, modified). bile dal centinaio al migliaio di metri, e sono dissecate da sistemi fluvio-torrentizi di basso ordine, cataclinali, drenanti direttamente nell'adriatico. i fondivalle sono terrazzati da più ordini di depositi alluvionali, costituiti da depositi di ghiaie calcaree poligeniche, organizzati, di norma, in tre ordini di terrazzi, di origine francamente climatica, la cui messa in posto è iniziata nel ple istocene medio (1° ordine), è proseguita nel pleistocene medio-finale (2° ordine) e si è conclusa, con il 3° ordine, nel pleistocene superiore; segue un 4° ordine (olocene), entro cui è inciso l'attuale alveo fluviale, la cui genesi viene prevalentemente associata all'antropizzazione dei versanti (biondi & coltorti, 1983; gentili & pambianchi, 1987; coltorti, 1997). le caratteristiche climatiche dell'area di studio, determinate sulla base dei dati riferiti al periodo 19212003, sono piuttosto omogenee e del tutto congruenti con quelle del più esteso settore centrale e meridionale del versante adriatico dell'italia (fa z z i n i & gi u f f r i d a, 2005). la piovosità media annua è compresa tra i 600 mm della costa ed i 1.100 mm della fascia montana; il numero dei giorni di pioggia è compreso tra 60 e 75, pur con una forte variabilità intrannuale; le intensità medie giornaliere sono di 10-12 mm. le precipitazioni tendono in genere ad aumentare avvicinandosi al fianco orientale della dorsale appenninica, con un evidente aumento, per il prevalente effetto orografico, dei valori pluviometrici in corrispondenza delle dorsali spartiacque. il regime pluviometrico dominante è di tipo sublitoraneo, con un massimo assoluto mensile in novembre; l'autunno risulta essere la stagione più piovosa, con un secondo massimo in primavera. la stagione estiva è piuttosto secca, ma, di norma, non siccitosa. infatti, raramente i periodi senza precipitazioni superano i 40 giorni ed inoltre si registra una marcata differenza tra le aree pedemontane, nelle quali in estate sono più frequenti i fenomeni temporaleschi di tipo convettivo-orografico, e quelle litoranee. le temperature medie annue variano tra i 12,5°c ed 15,5°c; il mese più freddo è gennaio (3,5-7°c) e le temperature massime si registrano in luglio ed agosto (22-25°c circa). l'escursione termica annua si attesta tra 17 e 19°c mentre quella giornaliera oscilla tra i 7°c della costa ed i 10°c delle conche interne. il gradiente termico verticale annuo è di 0,54°c/100m. le caratteristiche termo-pluviometriche dell'ottantennio considerato possono essere estese indietro nel tempo fino alla seconda metà del secolo xix, mentre per i tre secoli precedenti (1550-1850) anche nell'area di studio si sono risentiti gli effetti della “piccola età glaciale”, caratterizzata, alle latitudini medie, da un aumento complessivo delle precipitazioni e dal ripetersi di estati piovose (le roy ladurie, 1971; pinna, 1984). nel versante adriatico dell'italia centrale l'impatto antropico assume valenza morfogenetica a partire dal xvi secolo, con l'avvio di attività agro-silvo-pastorali nelle aree circostanti ai primi nuclei urbani, estese ampiamente nei secoli successivi sia in relazione al progressivo incremento demografico che, soprattutto, all'assenza di uno stabile legame tra il sito messo a coltura e il colono. infatti, quest'ultimo ricavava campi e pascoli da diboscamenti di aree ottenute in concessione, sfruttandone le massime potenzialità produttive del suolo, senza porre in essere opere tendenti alla conservazione di esso (an s e l m i, 1971 e 1985). veniva così favorita l'attivazione di rapidi ed intensi processi erosivi, che spintisi fino al livello regolitico, rendevano impossibile il prosieguo dell'attività agricola o pastorale, costringendo l'agricoltore a spostarsi su altre aree dove ripetere le stesse pratiche ("nomadismo", ge n t i l i, 2002). un ulteriore ed importante fattore di controllo dell'intensa morfodinamica del periodo può essere individuato nel contemporaneo incremento delle precipitazioni della già citata “piccola età glaciale”. tale assetto morfo-colturale veniva modificato a partire da circa metà del xix secolo, in seguito all'affermazione della piccola proprietà terriera, che legando stabilmente il colono ai siti messi a coltura ha indotto quest'ultimo ad operare la preventiva o contestuale sistemazione agraria dei pendii (terrazze, fossi, siepi, ecc.), ad effettuare la continua ed attenta manutenzione degli stessi e ad attuare pratiche colturali idonee alla conservazione del suolo. con i primi decenni del xx secolo si sono definitivamente consolidati i lineamenti 320 tabella 2 principali caratteristiche morfologiche e morfometriche dei fiumi delle marche (modificato da coltorti et al., 1995). main morphologic and morphometric characteristics of the marchean rivers (modified from coltorti et al., 1995). bacino asta principale bacino di drenaggio bacino area quota (m s.l.m.) rapporto di lunghezza pendenza f* d* idrografico (km2) max media rilievo (rh) (km) media (%) (km-2) (km-1) foglia 701 1049 359 0.02 71.5 1.4 0.71 0.88 metauro 1405 1384 470 0.02 94 1 0.77 0.98 cesano 413 1071 322 0.02 56.5 1.8 0.73 0.91 misa 376 793 217 0.02 44 1.1 0.82 1.06 esino 1148 1361 404 0.02 77.5 1.5 0.86 1.13 musone 642 1479 278 0.03 65 2.2 0.78 potenza 773 1571 430 0.02 88 0.9 0.85 1.11 chienti 1294 2102 508 0.03 91 1.2 0.86 1.13 tenna 484 2233 555 0.04 69 3.2 0.93 1.24 aso 280 2476 585 71.5 2.7 1.01 1.37 tronto 1192 2476 784 0.03 97.5 2.1 1.12 1.55 (*) frequenza di drenaggio e densità di drenaggio; valore estimato alla scala 1:100.000 (da dramis & gentili, 1975) p. farabollini et al. fondamentali del paesaggio rurale dell'area, caratterizzato dall'a l b e r a t a: campo coltivato a seminativo in cui veniva coltivata contemporaneamente la vite, “maritata” ad un sostegno vivo costituito dall'acero campestre (acer campestre) o dall'olmo comune (ulmus minori) . l'alberata, compresa in “campi chiusi” delimitati da siepi, scarpate e fossi di scolo (che afferivano ad una rete idrografica incassata e ben delineata), ha rappresentato l'elemento distintivo del paesaggio rurale dell'italia centrale fino al primo decennio della seconda metà del xx secolo con la profonda trasformazione agraria, iniziata sul finire degli anni '50 e realizzatasi attraverso il massiccio uso di mezzi meccanici, i versanti sono stati riportati agli originari profili (producendo di conseguenza “campi aperti”) nei quali si sono affermate rapidamente le colture estensive. (de s p l a n q u e s, 1975; sereni, 1979; gentili & pambianchi, 2002; buccolini et al., 2007). relativamente agli alvei fluviali, si segnala la presenza di importanti opere antropiche: invasi artificiali e opere di derivazione, costruiti in tempi diversi per usi irrigui o per la produzione di energia elettrica, che interrompono, talora in più punti, i corsi d'acqua principali e/o i loro maggiori affluenti. numerose sono anche le opere di regimazione, costituite essenzialmente da briglie, soglie di fondo, pennelli ed argini artificiali a difesa spondale, costruiti per larghissima parte nella prima metà del secolo appena trascorso. inoltre, notevoli cambiamenti nel bilancio idrico vengono prodotti anche da una fitta rete di canali artificiali e da numerose derivazioni e captazioni, presenti soprattutto nel tratti medio-finali dei corsi d'acqua (conti et al., 1983; coltorti et al., 1995; farabollini, 1995). 3. i fenomeni erosivi nei principali fiumi marchigiani: stato dell'arte delle conoscenze numerosi sono i fenomeni erosivi riscontrabili lungo gli alvei delle basse e medie valli dei fiumi marchigiani: in quasi tutti i fondivalle si evidenziano infatti vistosi processi di approfondimento dell'erosione in alveo che interessano, in particolar modo, le zone di confluenza tra i maggiori affluenti e l'asta fluviale principale (es.: chienti-ete morto; chienti-cremone; potenza-monocchietta; ecc.). l'intensa attività agricola in atto sui versanti e, soprattutto, le attuali tecniche agricole ed i tipi colturali adottati, hanno ridotto fortemente i tempi di corrivazione, favorendo apporti liquidi all'asta fluviale, tanto cospicui e rapidi da attivare intensi fenomeni erosivi. a questi ultimi risultano associati, sempre più frequentemente, fenomeni franosi, che interessando soprattutto litologie pelitiche e depositi eluvio-colluviali fini, vengono rapidamente allontanati dalle acque correnti superficiali. numerosi sono infatti gli autori (per citarne alcuni: co n t i et al., 1983; bu c c o l i n i & ge n t i l i, 1986; ge n t i l i & pa m b i a n c h i, 1987; bi s c i et al., 1992; co l t o r t i et al. , 1995; ar i n g o l i et al., 2003; co l t o r t i & fa r a b o l l i n i, 2004; br u n e l l i & fa r a b o l l i n i, 2005). che evidenziano tale diffusa situazione, peraltro confermata da ricerche più estensive effettuate dalla regione marche nell'ambito del cosiddetto progetto “rim reticolo idrografico minore”. lungo la maggior parte degli alvei fluviali dei principali fiumi marchigiani, in corrispondenza di opere di regimazione idraulica realizzate soprattutto per scopi irrigui, sono stati rilevati, nell'arco di tempo di circa un decennio, arretramento delle scarpate fluviali dell'ordine della decina di metri (aringoli et al., 2003; brunelli & fa r a b o l l i n i, 2005). le analisi, effettuate attraverso la comparazione di di foto aeree e di documentazione cartografica di periodi diversi, anche a diversa scala (cartografia igm del 1876, del 1955 e del 1977; alla scala 1:25.000; ctr regione marche alla scala 1:10.000 del 1971 e del 1999), hanno permesso di stabilire per i processi in parola una loro significativa intensificazione dopo il 1977. consistenti modificazioni morfologiche sono state rilevate anche per quanto riguardano le configurazioni d'alveo dei corsi d'acqua, con intensificazioni di particolari processi (migrazioni di meandri; accentuazione di sinuosità; arretramento di scarpate; ecc.) che hanno portato alla realizzazione di numerosi interventi di consolidamento, molti dei quali attraverso gabbionate e interventi di ingegneria naturalistica, i primi dei quali, realizzati da circa 10 anni, non hanno dato, al momento, i risultati attesi. il restringimento delle sezioni di deflusso, prodotto dall'incisione ha attivato processi di erosione delle sponde, anche di qualche metro (fig. 2), soprattutto a valle delle opere idrauliche (briglie, traverse, pennelli, ecc.), producendo seri danneggiamenti, a volte di difficile recupero funzionale, dei manufatti posti lungo i corsi d'acqua. ulteriori fenomeni erosivi si rilevano nei tratti fluviali posti immediatamente a valle delle confluenze di canalizzazioni realizzate per uso idrico, dove il repentino aumento di portata liquida e la ristretta sezione di deflusso del canale confluente esalta la capacità erosiva delle acque dando luogo a processi di erosione laterale e verticale. situazioni eclatanti, con scalzamento al piede e genesi di scarpate di altezze dell'ordine della decina di metri, vengono riscontrate nella maggior parte dei fiumi marchigiani (esino, musone, potenza, chienti, tenna, aso, tronto). in particolare, tali fenomeni vengono esaltati dal forte sfruttamento dell'acquifero di subalveo che, soprattutto durante i mesi estivi, contribuendo significativamente al drastico abbattimento delle portate di magra, favorisce la genesi nello stesso letto fluviale di fenomeni di "crepacciatura" delle argille, determinanti per l'attivazione di successivi processi erosione (farabollini et al., 2000; aringoli et al., 2003). sul fiume tenna e sul fiume aso si registrato i più alti valori dell'approfondimento dell'erosione in alveo, tanto che in molte parti, per contrastare tale fenomeno, sono state costruite, negli anni '70, briglie e traverse (conti et al., 1983; buccolini & gentili, 1986; gentili & pa m b i a n c h i, 1987; bi s c i et al., 1992; co l t o r t i et al. , 1995). in molti casi tali interventi hanno innescato una serie di processi erosivi che hanno esaltato ancor di più l'erosione in alveo. a seguito dell'erosione regressiva innescata dalla realizzazione di tale opere, si sono prodotti intensi fenomeni di scalzamento al piede delle stesse opere in alveo (fig. 3), ed in alcuni casi si sono prodotti cedimenti e crolli di infrastrutture viarie, realizzate a valle delle briglie e traverse (grottazzolina, servigliano, ecc.). nelle zone di raccordo tra l'asta fluviale principale e la rete idrografica di basso ordine, si rilevano forti diffi321processi di approfondimento dell’erosione ... coltà di deflusso per le acque di versante, legate alle opere connesse alla diffusa e continua espansione delle attività antropiche (estensione delle aree coltivate, sviluppo di nuovi nuclei abitati ecc.), che tendono a ridurre le sezioni di deflusso dei tratti terminali dei canali della rete idrografica minore, modificandone le condizioni di permeabilità di superfici di estensione significativa. a tale assetto della rete idrografica sono connessi gli intensi e frequenti fenomeni di esondazione e/o allagamento delle piane alluvionali della maggior parte dei sistemi fluviali marchigiani, verificatisi di recente anche in periodi di precipitazioni meteoriche non eccezionali (potenza 1998, 1999, 2001; chienti, 1999, 2000 e 2001; tenna, 1999, 2001, 2002; tronto, 2000, 2002; aspio, 2006). lungo l'asta fluviale del fiume tronto, interessata nell'aprile del 1992 da una disastrosa piena che ha causato ingenti danni (bisci et al., 1999), è stato possibile verificare come l'intensa antropizzazione del territorio, iniziata fin dai primi anni del 1900, modificando notevolmente sia la configurazione di alveo del fiume stesso che le caratteristiche idrauliche dell'alveo, sia stata la principale responsabile dell'evento calamitoso (fa r abollini, 1995; farabollini et al., 2000; brunelli & farabollini, 2005; coltorti & farabollini, 2007). 4. i fenomeni erosivi nei fiumi potenza, chienti e tenna: dati e discussione il presente lavoro illustra ed interpreta i dati acquisiti da recenti osservazioni condotte principalmente lungo gli alvei dei fiumi chienti, potenza e tenna (marche centrali) soprattutto nel loro tratto intermedio. indagini di dettaglio, svolte sia sul terreno che attraverso la documentazione storica, hanno messo in particolare evidenza intensi processi erosivi in corrispondenza dei tratti di alveo situati a valle di impianti di depurazione delle acque reflue. le analisi di laboratorio eseguite su campioni di argille del substrato affioranti in alveo nei pressi di detti impianti, evidenziano alcune importanti modificazioni sulla struttura cristallina dei minerali argillosi. nell'alveo del chienti, nel tratto compreso tra l'abitato di tolentino e la corrispondente zona industriale, l'approfondimento dell'erosione lineare in alveo ha raggiunto valori di 10-12 metri all'interno del substrato pelitico. rispetto alle osservazioni effettuate nel 1987 ( ge n t i l i & pa m b i a n c h i, 1987), tale approfondimento nel substrato sembra essere attualmente regredito verso monte provocando lo scalzamento al piede dei piloni della superstrada “valdichienti”. 322 fig. 2 fenomeni franosi connessi con l'approfondimento dell'incisione in alveo, in un tratto del fiume chienti (a tolentino) con evidente allargamento della sezione fluviale. landslides due to downcutting in the river chienti (at tolentino), with enlargement of fluvial section. fig. 3 evidenti fenomeni di scalzamento al piede: a) briglia nel fiume tenna; b) traversa nel fiume chienti. erosion phenomena at the foot of the slope. small dam: a) in the river tenna; b) in the river chienti. p. farabollini et al. nei pressi del depuratore di tolentino (località la rancia) l'incisione dell'alveo, appena abbozzata nel 1987, attualmente risulta molto profonda. il confronto tra i dati derivanti da osservazioni dirette di campagna, su strutture ed infrastrutture antropiche, testimonianze orali e documenti cartografici di periodi diversi, permettono di valutare un incrementato dell'erosione lineare in alveo 1,5-2 m in circa 10 anni. per effetto di tale approfondimento si è registrata, nei pressi della centrale elettrica di pianarucci, posta poco a monte dello scarico del depuratore: la distruzione della soglia in cemento armato che collegava il canale artificiale all'alveo fluviale; la propagazione verso monte dell'erosione, per circa 50 m; una profonda incisione che ha modificato la geometria del piede del versante attivando sullo stesso processi gravitativi che hanno coinvolto strutture abitative. il confronto tra le foto aeree del 1978 e del 1999, permette di rilevare significative variazioni del tracciato fluviale del chienti. il tracciato fluviale del 1978 oltre ad apparire molto più regolare e rettilineo, risultava delimitato da scarpate poco elevate. la “penisola” delimitata in sinistra idrografica dal fiume chienti ed in destra dal canale di irrigazione, risultava allungata in direzione nne-ssw e dalla forma regolare; attualmente invece tale forma risulta erosa per circa 20 m rispetto alla situazione del 1978 e presenta una forma fortemente sinuosa derivante dallo spostamento verso sud dell'alveo del chienti, proprio in corrispondenza del tratto in cui è stato realizzato il depuratore (fig. 4). le sponde che delimitano attualmente il letto fluviale, presentano acclività molto più accentuata del passato con versanti 323 fig. 4 confronto tra le situazioni morfologiche dell'alveo del fiume chienti nei pressi di tolentino: sopra nel 1992, sotto nel 2002. comparison among several morphologies in the river chienti, near tolentino: upper, in 1992; lower, in 2002. processi di approfondimento dell’erosione ... ripidi e la larghezza della sezione fluviale appare più ampia per effetto dell'arretramento delle stesse sponde; l'entità del fenomeno può essere valutata, in alcuni punti, anche in qualche metro. i periodici sopralluoghi effettuati negli ultimi anni, con cadenza semestrale, hanno permesso di verificare come il letto di magra del fiume sia in approfondimento, i cui tassi sono prossimi ai 10 cm/anno. attualmente l'intera area è oggetto di interventi di risanamento effettuati attraverso opere di riprofilatura dei versanti e di ingegneria naturalistica. ulteriori fenomeni erosivi si rilevano nei tratti fluviali posti immediatamente a valle delle confluenze di canalizzazioni realizzate per uso idrico, dove il repentino aumento di portata liquida e la ristretta sezione di deflusso del canale confluente esalta la capacità erosiva delle acque dando luogo a processi di erosione laterale e verticale. particolarmente vistoso è il processo in atto a valle della citata centrale enel-pianarucci, dove, soprattutto in sinistra idrografica, è in corso lo scalzamento al piede di una scarpata dell'altezza di oltre 15 metri. analogo fenomeno si rileva in località rocchetta (nell'alveo fluviale del potenza), dove opere di regimazione idraulica realizzate soprattutto per scopi irrigui, hanno provocato, nell'arco di tempo di circa un decennio, un arretramento decametrico delle scarpate fluviali. il confronto dei dati derivanti dall'esame di foto aeree e documenti cartografici di periodi compresi tra il 1955 e il 1999, permette di stabilire per i processi in parola una loro significativa intensificazione dopo il 1977. il canale artificiale della centrale enel di rocchetta, già esistente nel 1955, che correva in sinistra idrografica al fiume potenza, ad una quota di circa 180 m s.l.m., poco prima del 1977 è stato spostato verso monte di circa 200 m, alla quota di circa 185 m s.l.m., a causa dei processi gravitativi che stavano interessando il versante tra il canale artificiale e la sponda di sinistra del fiume potenza, in conseguenza della creazione del gradino di raccordo del canale artificiale stesso con il fiume potenza (fig. 5). consistenti modificazioni morfologiche sono state rilevate anche per il meandro ubicato poco a monte dell'abitato di rocchetta, la cui scarpata esterna è arretrata con un tasso di circa 0,5 m/anno (24 m nel periodo compreso il 1955 e il 1999). tale scarpata è stata oggetto di diversi interventi di consolidamento (mediante gabbionate), i primi dei quali, realizzati da circa 10 anni, non hanno dato positivi risultati; nuove opere sono state eseguite nel 1998, più estese e meglio intestate nel substrato geologico. inoltre, in questo tratto fluviale, soprattutto a valle della confluenza del canale di scarico delle acque che alimentano la centrale, sono in atto fenomeni di approfondimento dell'erosione in alveo, che per il periodo 1987-1999 vengono valutati in 8-9 m (circa 0,7 m/anno); vi si possono apprezzare anche modificazioni planimetriche del tracciato del letto fluviale ordinario (fig. 6). infatti i processi di erosione laterale ed i connessi fenomeni franosi attivati alternativamente sulle sponde destra e sinistra, hanno prodotto una complessiva migrazione verso valle del meandro. 4.1 analisi chimica delle acque a causa del suo altissimo potere solvente, l'acqua, oltre a contenere le diverse sostanze naturali contiene anche quelle prodotte dall'attività umana. queste sostanze si trovano, in forma ionica, in un ampio range di concentrazione (da pochi nanogrammi per litro ng/l) a diverse centinaia di milligrammi per litro mg/l) in funzione della loro abbondanza in natura, della loro solubilità e dei processi chimico-fisici cui sono sottoposte. i principali elementi e/o composti disciolti nell'acqua sono i cationi ca++, na+, mg++, gli anioni hco3 -, so4 =, cl-, e la silice (sio2). il contenuto e la percentuale dei principali ioni dipende, certamente, dalla composizione chimica delle rocce e dei terreni presenti nell'area di drenaggio (fetter, 1999). le sostanze che più frequentemente è possibile trovare, soprattutto derivanti dalle attività umane, e quindi come traccia di inquinamento, sono: a c i d i e a l c a l i , c l o r o (vari tipi di cloruri), a m m o n i a c a ( n h3 e sali ammoniacali), idrogeno solforato, solfati ( s o4 -) soprattutto se 324 fig. 5 confronto tra le situazioni morfologiche dell'alveo del fiume potenza nei pressi di la rocchetta dalla cartografia topografica del 1978 e del 1999. comparison among several morphologies in the river potenza near la rocchetta obtained from topographic maps of 1978 and 1999. p. farabollini et al. presenti delle cartiere, s o l f i t i ( s o3 -), c i a n u r i ( c n-), n i t r i t i ( n o2 -), n i t r a t i ( n o3 -), fosfati, sali di ferro e m a n g a n e s e, residui vari di idrocarburi, olii vegetali, composti organici e metalli pesanti, fino anche ai r a d i o i s o t o p i . l'equilibrio chimico e fisico dell'ambiente idrico è importante non solo per gli effetti diretti che può avere sulla salute dell'uomo, ma anche per gli effetti meno evidenti che può avere sul sistema naturale. un esempio è dato dalle soluzioni acquose che interagiscono con il materiale adsorbente, sia organico che inorganico, che adsorbe una parte dei solidi in soluzione, sia dissociato che non dissociato. tale adsorbimento è dovuto all'attrazione fisica tra due particelle solide, ma anche all'attrazione elettrostatica di due cariche elettriche di segno contrario (adsorbimento selettivo o chimico); in questo ultimo caso gli ioni non vengono adsorbiti solo sulla superficie del minerale, ma alcuni di essi possono entrare nel reticolo cristallino, attraverso il processo dello scambio ionico (chiesa, 1998). nella tabella sottostante, vengono riportati i risul325 fig. 6 processi gravitativi interessanti la sponda in destra idrografica del fiume potenza (a valle di san severino marche). gravitational phenomena affecting the right side of river potenza (valleyward of san severino marche). tabella 3 elementi chimici (in mg/l) e conducibilità elettrica calcolati per le acque campionate. concentration of ions (mg/l) and electric conductivity of water samples. tenna camerino camerino s. severino s. severino tolentino tolentino a valle a monte a valle a monte a valle a monte a valle calcio (mg/l) 108,8 109,2 109,2 80,5 86,2 81,6 83,9 magnesio (mg/l) 22 7,4 8,6 4,7 4,2 5,7 5,7 sodio (mg/l) 28,6 12,5 15,2 16,8 15,8 12,6 14 potassio (mg/l) 8,4 5,6 6,8 7,2 7,3 6,8 6,6 bicarbonato (mg/l) 322 330 338 275 280 258 264 cloruri (mg/l) 58,8 20,6 22,4 15,5 17,1 19,3 23,4 solfati (mg/l) 86,2 36,7 41,3 17,8 23,2 23,3 22,6 conducibilità elettrica (µs/cm) 930 578 582 413 423 463 475 processi di approfondimento dell’erosione ... tati delle analisi chimiche, effettuate presso i l dipartimento di scienze igienistiche dell'università di camerino, delle acque campionate in corrispondenza degli impianti di depurazione, sia a monte che a valle dello scarico. tali valori sono stati anche messi a confronto con i risultati di ricerche effettuate dallo stesso laboratorio negli anni precedenti (branca, 1976) 4.2 caratteristiche fisico-meccaniche e mineralogiche delle argille plioceniche al fine di verificare se la presenza di inquinanti nelle acque reflue degli impianti di depurazione potesse produrre variazioni mineralogiche e fisico-meccaniche nelle argille del substrato (es p o s i t o & di o g e n e, 2000), tali da favorire i fenomeni di incisione rilevati e descritti, sono stati prelevati tre campioni (uno a monte e due a valle del depuratore di tolentino, identificati con tol. 1, tol. 2 e tol. 3) sottoposti ad analisi geotecniche e mineralogiche i risultati iniziali delle analisi del primo tipo sono riportati in tabella 4. sono tuttora in corso ulteriori analisi per la valutazione della resistenza al taglio, della capacità di scambio cationico, e del chimismo delle acque di depurazione, al fine di giungere ad una più diretta ed esauriente interpretazione e valutazione dei meccanismi di alterazione. tuttavia, da tali prime analisi, si può già verificare come tra il campione di monte ed i campioni di valle vi sia una evidente diminuzione nel contenuto di acqua naturale e nel valore del limite di liquidità a cui corrisponde un aumento nell'indice di plasticità. sugli stessi campioni citati sono state successivamente eseguite analisi diffrattometriche ai rx sulla sola frazione argillosa passante al setaccio astm 270 (ø 0,064mm). tale analisi è stata eseguita attraverso la preparazione di vetrini su cui è stata fatta decantare una miscela di acqua e argilla raccolta attraverso una pipetta, in modo tale da avere campioni orientati (aon) per avere una migliore risoluzione della componente mineralogica argillosa. i tracciati diffrattrometrici, derivanti dall'analisi ai rx (condizioni strumentali: 40kv x 20 ma; 1cm/min; 1°/min; ct = 4''; r = 4 x 102; da 2° a 35°), sono stati quindi interpretati e confrontati tra loro in modo da evidenziare le eventuali differenze nella composizione mineralogica tra il campione prelevato a monte del depuratore (tol. 1) ed i campioni prelevati a valle dello stesso (tol. 2 e tol. 3). tale comparazione evidenzia una sostanziale uniformità composizionale dei campioni (tab. 5), ma d'altra parte permette anche di verificare che esistono notevoli differenze da un punto di vista delle percentuali di contenuto delle singole componenti 326 contenuto mineralogico tol. 1 tol. 2 tol. 3 smectite ++ +++ +++ illite + non valutabile non valutabile interstrati i-mo ++ +++ +++ clorite + caolinite ++ + + calcite +++ + + quarzo ++ + + plagioclasi + +/+/minerali in tracce dolomite gesso; dolomite gesso; dolomite tabella 4 caratteristiche fisico-meccaniche del substrato argilloso pliocenico nelle varie località prese in considerazione (cm= camerino monte; cv= camerino valle; ssm= san severino monte; ssv= san severino valle; tol1= tolentino monte; tol2 e tol3= tolentino valle; w (%) = contenuto naturale d'acqua; y (gr/cm3) = peso volume; ll (%) = limite di liquidità; lp (%) = limite di plasticità; ip = indice di plasticità; ic = indice di consistenza) geotechnical characteristics of the clayey bedrock sampled in the study areas (cm= camerino, mountainward of the purifier; cv= camerino, valleyward of the purifier; ssm= san severino, mountainward of the purifier; ssv= san severino, valleyward of the purifier; tol1= tolentino, mountainward of the purifier; tol2 e tol3= tolentino, valleyward of the purifier; w (%) = natural water content; y (gr/cm3) = specific gravity; ll (%) = liquidity limit; lp (%) = plasticity limit; ip = plasticity index; ic = consistence index) calcare limiti di atterberg campione totale w (%) y (g/cm3) ph % caco3 ll (%) lp (%) i.c. i.p. cm 43.70 25.40 1.919 8.74 31.10 17.73 0.43 13.37 cv 38.60 32.44 1.873 8.41 37.3 19.66 0.27 17.60 ssm 42.00 22.49 1.822 8.64 26.97 19.98 0.64 6.991 ssv 37.40 29.16 1.821 8.60 26.47 20.19 n.p. 6.29 tol 1 49 15.35 2.23 9 49 26 n.p. 23 tol 2 42 4.76 2.27 8 61 25 n.p. 36 tol 3 48 10.12 2.30 8 68 27 n.p. 41 tabella 5 composizione mineralogica ricavata dall'interpretazione dei tracciati diffrattometrici. mineralogical composition from xrd pattern interpretation. p. farabollini et al. mineralogiche; particolarmente evidenti tra il campione di monte rispetto a quelli di valle. piccole differenze si riscontrano anche tra i due campioni di valle, ma tali differenze, anche sulla base delle caratteristiche fisicomeccaniche degli stessi, sembrano imputabili a variazioni litologiche e/o granulometriche. in particolare è da notare come nei campioni di valle vi sia un netto aumento del contenuto di smectite e minerali interstratificati di tipo smectite-illite a scapito della clorite-caolinite. analogamente sia il contenuto di calcite che di quarzo sembrano diminuire sensibilmente, soprattutto per quanto riguarda quest'ultimo, anche se allo stato attuale non è ancora possibile attribuire tale modificazione a scambio cationico, cui può essere stato sottoposto il substrato argilloso, a seguito dell'inquinamento delle acque di scarico del depuratore. le analisi difrattometriche eseguite, testimoniano una differenza composizionale dei campioni prelevati a valle del depuratore, imputabile, in accordo con esposito & diogene (2002), a modificazioni legate alla presenza di sostanze inquinanti nelle acque di scarico che provocherebbero la rottura di particolari legami ionici. tali modificazioni sono inoltre testimoniate dal valore dell'indice di plasticità dei campioni di valle rispetto a quelli di monte. il maggior contenuto in minerali di tipo smectitico o di tipo interstratificati i-mo, riscontrato nei campioni di valle rispetto a quelli di monte (tab. 5), a scapito dei minerali argillosi di tipo illitico e cloritico-caolinitico, permetterebbe quindi una più facile ed efficace aggressione da parte dei processi erosivi fluviali, favorendo la più accentuata incisione dell'alveo. infatti, le analisi mineralogiche preliminari (aringoli et al., 2003) permettono di ipotizzare come il passaggio illite-interstratificati i-mo-smectite sia alla base della maggiore facilità alla rottura dei legami ionici delle argille del substrato. a questo, inoltre, si aggiunge la possibilità che gli strati più superficiali di terreno, subendo cicli stagionali di essiccamento ed umidificazione, a seguito di maggiori emungimenti della falda di subalveo, soprattutto in condizioni di periodi siccitosi lunghi, possano aumentare la "crepacciatura" e quindi il maggior degrado del substrato argilloso. 5. conclusioni i risultati presentati in questo lavoro si riferiscono a 15 anni di osservazioni e monitoraggi eseguiti soprattutto nei tratti medio-bassi degli alvei dei fiumi chienti e potenza dove, a seguito della forte e crescente antropizzazione della piana alluvionale, sono stati realizzati restringimenti della sezione dell'alveo, impermeabilizzazioni della piana alluvionale, impianti di depurazione, scarichi di sostanze inquinanti, con conseguente considerevole modificazione della dinamica idrologica. lo stato generale dei fenomeni di erosione in alveo mostra dal 1987, quando iniziarono le prime osservazioni di dettaglio, ad oggi, un aumento considerevole dei fenomeni di approfondimento sia nel materasso alluvionale che, soprattutto, nel substrato pelitico dei tratti medi dei corsi d'acqua considerati. nel caso dei depuratori, studi intrapresi di recente hanno messo in luce come, a valle degli stessi, i processi erosivi si manifestano con una maggiore intensità e con approfondimenti del corso d'acqua maggiori che a monte dell'impianto: analisi mineralogiche e geotecniche, eseguite su campioni di substrato, che in tutti i casi era dato da argille plioceniche, affioranti in alveo nei pressi dei depuratori evidenziano alcune importanti modificazioni della struttura cristallina dei minerali argillosi. con molta probabilità la presenza di sostanze inquinanti nelle acque di scarico dei depuratori, provocherebbero la rottura di alcuni legami ionici, favorendo una maggiore e più intensa erosione del substrato pelitico. analogamente, le opere idrauliche (canale di derivazione, ecc.) costruite lungo il fiume potenza, in corrispondenza di la rocchetta, sono alla base degli intensi approfondimenti e soprattutto dell'evidente arretramento della scarpata esterna dell'ansa del fiume potenza che, con un arretramento superiore ai 20 metri in 40 anni, ha interessato anche la strada statale della valle del potenza. gli esempi sopra riportati rappresentano casi emblematici e comuni per la quasi totalità delle piane alluvionali delle marche che hanno subito, soprattutto nei loro tratti medio-bassi una rapida antropizzazione particolarmente intensa negli ultimi decenni. gli alvei fluviali già particolarmente compromessi da: attività estrattive in alveo degli anni '60-'70; interventi di regimanzione degli anni successivi, talvolta non adeguatamente dimensionati; entrata in funzione degli impianti di depurazione delle acqua reflue nella metà degli anni '80, hanno mostrato una intensa e altrettanto rapida risposta agli squilibri indotti dall'antropizzazione testimoniando, con ogni probabilità, il superamento della soglia di sostenibilità dell'ambiente fluviale. ringraziamenti gli autori desiderano ringraziare i due revisori anonimi per i consigli ed i suggerimenti utili a migliorare la versione originale del manoscritto. questo lavoro è stato eseguito con i finanziamenti dell'università degli studi di camerino (far 2006 e 2007 farabollini e materazzi). bibliografia an d r e w s e.d. (1986) downstream effects of flaming gorge reservoir on the green river, colorado and utah. boll. geol. soc. am., 97, pp. 1012-1023. anselmi s. (1971) economia e vita sociale in una regione italiana tra sette o ottocento. argalia, pp. 224. anselmi s. (1985) una storia dell'agricoltura marchigian a. cassa di risparmio di jesi, consorzio librai marchigiani, ancona. ar i n g o l i d., bi s c i c., fa r a b o l l i n i p., fa z z i n i f., ge n t i l i b., materazzi m. & pambianchi g. (2003) recent observation on erosional processes in the potenza and chienti river alluvial plains (central marche, italy). in: castaldini et al., eds, “geomorphological sensitivity and system response”, proc. viii italian-romanian workshop on geomorphology, camerino-modena 4-9 luglio 2003, pp. 21-34. ar u n a l a n d a n k., sa r g u n a m a., lo g a n a t h a n p., kr o n e r.b. (1973) application of chemical parameters to prediction erodibility. in soil erosion: causes 327processi di approfondimento dell’erosione ... and mechanism; prevention and control: special report hrb n. 135, national academy of science, washington d.c. ba r n a r d r.s. & me l h o r n w.n. (1982) m o r p h o l o g i c and morphometric response to channelization: the case history of big pine creek ditch, benton county, indiana. in: craig, r.g., craft, j.l. (eds.), applied geomorphology, proc., 11t h b i n g h a m t o n geomorphology symposium, pp. 224-239. bi l l i p. & ri n a l d i m. (1997) human impact on sediment yield and channel dynamics in the arno river basin (central italy). in: walling et al., eds., human impact on erosion and sedimentation. proc. of rabat symp., iahs, publ. 245, pp. 301-311. bi o n d i e. & coltorti m. (1983) the esino flood plain during the holocene . xi inqua congress, moscow. bisci c., dramis f. & gentili b. (1992) recent and present geomorphological evolution of river beds and mouths in central-southern marche (italy). geooko plus, 3, pp. 83-96. bi s c i c., fa r a b o l l i n i p., fa z z i n i m. & ma r z i a l e t t i v . (1999) influenza di fattori naturali ed antropici sull'evento alluvionale del 1992 del fiume tronto (italia centrale adriatica). studi geol. camerti, vol. spec. “workshop nazionale sulle acque: il ciclo dell'acqua”, pp. 61-68. br a g a g. & ge r v a s o n i s. (1989) evolution of the po river: an example of the application of historic maps. in: petts, g.e., moller, h., roux, a.l. (eds.), historical change of large alluvial rivers: western europe, wiley, pp. 113-126. br a n c a g. (1976) studi sull'inquinamento dei fiumi chienti e potenza. amm. prov. macerata, pp. 198. brunelli m. & farabollini p. (2005) fenomeni di erosione e dinamica fluviale in alcuni fiumi delle marche centro-meridonali . in: brunel li & farabollini, eds., dinamica fluviale. ordine dei geologi delle marche, tip. bellabarba, pp. 31-64. buccolini m. & gentili b. (1986) variazioni della foce in relazione all'evoluzione morfodinbamica recente dei fiumi chienti e tenna (marche centro-meridionali). mem. soc. geol. it., 42, pp. 343-349. buccolini m., gentili b., materazzi m., pambianchi g. & pi a c e n t i n i t. (2007) human impact and slope dynamics evolutionary trends in the monoclinal relief of adriatic area of central italy. catena, 71, pp. 96-109. canuti p., cencetti c., conversini p., rinaldi m. & tacconi p. (1992) dinamica fluviale recente di alcuni tratti dei fiumi arno e tevere. in: “fenomeni di erosione ed alluvionamento degli alvei fluviali”, ancona, pp. 21-36. cencetti c., tacconi p. & viglione f. (1994a) effetti di sistemazione d'alveo sulla dinamica fluviale di un torrente ghiaioso. atti conv. “man & mountain '94”, ponte di legno, 20-24 giugno 1994, pp. 221-229. cencetti c., tacconi p. & conversini p. (1994b) attività antropica e dinamica fluviale nell'alta val tiberina. atti conv. “man & mountain '94”, ponte di legno, 20-24 giugno 1994, pp. 631-656. ce n t a m o r e e. & de i a n a g. (1986) la geologia delle m a r c h e. studi geologici camerti, vol. spec., pp. 145. ch i e s a g. (1998) inquinamento delle acque sotterranee. metodi di indagine e di studio per la bonifica e la gestione delle acque inquinate. ulrico hoepli ed., milano, pp. 696. co c c o e., de ma g i s t r i s m.a. & de pi p p o t. (1978) studi sulle cause dell'arretramento della costa lucano-ionica: 1l'estrazione degli inerti lungo le aste fluviali. mem. soc. geol. it., 19, pp. 421-428. coltorti m. (1997) human impact in the holocene fluvial and coastal evolution of the marche region. catena, 30(4), pp. 311-335. coltorti m. & farabollini p. (2004) fluvial sedimentation in the marchean river valleys. field trip guidebook, flag-seqs 2004 meeting, siena, 711 september 2004, pp. 41-57. coltorti m. & farabollini p. (2007) geomorphological changes and human impact in the fluvial-coastal system of the river tronto (italy). quat. int., in stampa. co l t o r t i m., ge n t i l i b. & pa m b i a n c h i g. (1995) evoluzione geomorfologica ed impatto antropico nei sistemi idrografici delle marche: riflessi sull'ambiente fisico. mem. soc. geol. it., l i i i, pp. 271-292. conti a., di eusebio l., dramis f. & gentili b. (1983) evoluzione geomorfologica recente e processi in atto nell'alveo del tenna (marche meridionali). atti xxiii congr. geogr. it., 2(3), pp. 53-56. de s c r o i x l. & gautier e. (2002) water erosion in the southern french alps: climatic and human mechanism. catena, 50, pp. 53-85. de s p l a n q u e s h. (1975) campagne umbre: contributo allo studio dei paesaggi rurali dell'italia centrale. quaderni regionali dell'umbria, perugia, 1, pp. 135. dr a m i s f. & ge n t i l i b. (1975) la frequenza areale di drenaggio ed il suo impiego nella valutazione quantitativa dell'erosione lineare di superfici con caratteristiche omogenee. mem. soc. geol. it., 14, pp. 337-349. dutto f. & maraga f. (1994) variazioni idrografiche e condizionamento antropico. esempi in pianura padana. il quaternario, 7, pp. 381-390. es p o s i t o l. & di o g e n e g. (2002) effetti dell'inquinamento sul comportamento meccanico dei terreni. quad. geol. appl., 9(2), pp. 5-22. farabollini p. (1995) evoluzione geomorfologica quaternaria della fascia periadriatica tra ancona e v a s t o. tesi di dottorato inedita, università di perugia, pp. 155. fa r a b o l l i n i p., ge n t i l i b. & pa m b i a n c h i g. (2000) impatto antropico e dinamica fluviale nei bassi fondivalle delle marche centro-meridionali e dell'abruzzo settentrionale. atti conv. “le pianure. conoscenza e salvaguardia”, ferrara, 9-11 novembre 1999, pp. 51-55 fazzini m. & giuffrida a. (2005) une nouvelle proposition quantitative des regimes pluviometriques dans le territoire de l'italie: premiers resultats. in : climat urbain, ville et architecture, actes xviii colloque internationale de climatologie, genes, pp. 361-365. fe t t e r c.w. (1999) contaminant hydrogeology. prentice hall, pp. 500. ge n t i l i b. (2002) note di geomorfologia del parco 328 p. farabollini et al. nazionale dei monti sibillini. quaderni scientificodivulgativi, parco nazionale dei monti sibillini, n.6, aniballi, ancona, pp. 50. gentili b. & pambianchi g. (1987) morfogenesi fluviale ed attività antropica nelle marche centro-meridionali. geogr. fis. dinam. quat., 10, pp. 204-217. gentili b. & pambianchi g. (2002) la dégradation gèomorphologique dans quelques régions viticoles et vinicoles des marches (italie centrale). géologues, 135, pp. 107-113. hooke j.m. (2007) human impacts on fluvial systems in the mediterranean region. geomorphology, 79, pp. 311-355. ke l l e r h a l s r. (1982) effects of river regulation on channel stability. in: hey et al., eds., gravel bed rivers. wiley, chichester, pp. 685-715. klingeman p.c., bravard j.p. & giuliani y. (1994) les impact morphodynamiques sur un cours d'eau soumis à un amenagement hydroelectique à derivation: le rhone en chautagne (france). rev. geogr. lyon, 69(1), pp. 75-89 lamberti a. (1993) le modificazioni recenti verificatesi nell'asta principale del po e problemi connessi. acqua-aria, 6, pp. 589-592. la j e c z a k a. (1995) the impact of river regulation, 1850-1990, on the channel and floodplain of the upper vistula river, southern poland. in: hickin, ed., river geomorphology. john wiley, new york, pp. 209-233. le ro y la d u r i e e., (1971) times of feast, times of famine: a history of climate since the year 1000. trans. b. bray, new york, doubleday, 426 pp. ma r a g a f. & mo r t a r a g. (1981) le cave per inerti lungo i corsi d'acqua: rapporti con la dinamica fluviale. bollettino associazione mineraria subalpina, 18(3-4), pp. 385-395. ma r c h e t t i m. (2002) environmental changes in the central po plain (northern italy) due to fluvial modifications and anthropogenic activi t ies. geomorphology, 44, pp. 361-373. mattias p. (2004) appunti di mineralogia nei problemi ambientali di inquinamento . quaderni del la facoltà di scienze mm.ff.nn., pp. 66. osman a.m. & thorne c.r. (1988) river bank stability analysis. jour. of hydraulics dvn., a.s.c.e., 114(2). parea g.c. (1978) trasporto dei sedimenti ed erosione costiera lungo il litorale tra il tronto e il fortore (adriatico centrale). mem. soc. geol. it., 1 9, pp. 361-367. pellegrini m. & zarotti l. (1975) un esempio di erosione accelerata in alveo: il torrente tiepido presso maranello (modena). atti soc. nat. mat. di modena, 106, pp. 145-156. pellegrini m., perego s. & tavaglini s. (1980) la situazione morfologica degli alvei degli affluenti emiliani del po. min. lav. pubbl., magistrato del po, parma. pe t i t f., po i n s a r t d. & br a v a r d j.p. (1996) c h a n n e l incision, gravel mining and bedload transort in the rhone river upstream of lyon, france (“canal de mirabel”). catena, 26, pp. 209-226. petts g.e. (1979) complex response of river channel morphology subsequent to reservoir construction. progr. phys. geogr., 3, pp. 329-362. pinna m. (1984) la storia del clima: variazioni climatiche e rapporto clima-uomo in età post-glaciale. mem. soc. geogr. it., 36, pp. 264. raglione m. & rodolfi g. (1977) osservazione sui processi morfogenetici in atto nel basso corso del fiume soleo (calabria). ann. ist. sper. studio difesa del suolo, 8, pp. 37-63. ri n a l d i m. & ro d o l f i g. (1995) evoluzione olocenica della pianura alluvionale e dell'alveo del fiume sieve nel mugello (toscana). geogr. fis. dinam. quat., 18, pp. 57-75. rinaldi m. & simon a. (1998) bed-level adjustments in the arno river, central italy. geomorphology, 22, pp. 57-71. roveri e. (1964) sul ciclo di erosione rinnovatosi lungo i corsi d'acqua dell'appennino emiliano. boll. soc. geol. it., 84, pp. 289-309. sa b a t o l. (1994) human impact on alluvial environments in calabria (southern italy). mem. soc. geol. it., 48, pp. 935-941. sear d.a. & archer d. (1988) effects of gravel extraction on stability of gravel-bed rivers: the woole water, northumberland, uk. in: kl i n g e m a n et al. , eds., gravel-bed rivers in the environment. water resources publications, llc, pp. 415-432. sereni e. (1979) storia del paesaggio agrario italiano. laterza, bari, 484pp. simon a. & rinaldi m. (2006) disturbance, stream incision, and channel evolution: the roles of excess transport capacity and boundary materials in controlling channel response. geomorphology, 7 9, pp. 361-383. surian n. (1999) channel changes due to river regulation: the case of the piave river, italy. earth surf. proc. land., 24, pp. 1135-1151. su r i a n n. & ri n a l d i m. (2003) morphological response to river engineering and management in alluvial channels in italy. geomorphology, 5 0, pp. 307-326. tagliavini s. (1975) aspetti e problemi geomorfologici connessi con l'attività estrattiva dell'emilia occidentale. atti conv. “cave e assetto del territorio”, bologna, 17 maggio 1975. veggiani a. (1963) ancora un esempio dei danni causati dalla ripresa del ciclo erosivo dei fiumi appenninici. boll. c.c.i.a.a., 17, pp. 17. wi l l i a m s g.p. & wo l m a n m.g. (1984) d o w n s t r e a m effects of dams on alluvial rivers. u.s. geological survey professional paper, 1286, pp. 83. wi l s o n k.v. & tu r n i p s e e d d.p. (1994) g e o m o r p h i c response to channel modifications of skuna river at the state highway 9 crossing at bruce, calhoun county, mississippi. u.s. geological surveywater-resources investigations report, vol. 94-4000, pp. 43. wi n k l e y b.r. (1982) response of the lower mississippi to river training and realignment. in: he y et al., eds. gravel-bed rivers. wiley, chichester, pp. 652-681. wohl e. (2006) human impacts to mountain streams. geomorphology, 79, pp. 217-248. 329 ms. ricevuto il 21 dicembre 2007 testo definitivo ricevuto il 18 marzo 2008 ms. received: december 21, 2007 final text received: march 18, 2008 processi di approfondimento dell’erosione ... imp.bondesan ppaalleeooeennvviirroonnmmeennttaall rreeccoonnssttrruuccttiioonn ffrroomm llggmm ttoo hhiissttoorriiccaall ttiimmee iinn tthhee lloowweerr ccooaassttaall ppllaaiinn ooff tthhee ppiiaavvee rriivveerr.. pprreelliimmiinnaarryy ppoolllleenn aannaallyyssiiss oonn aa 2200 mm ccoorree ooff llaaggoooonn aanndd fflluuvviiaall sseeddiimmeennttss aallddiinnoo bboonnddeessaann11,, mmiirrccoo mmeenneegghheell11,, aannttoonneellllaa mmiioollaa22 && ggiiaannnnaa vvaalleennttiinnii22 1 dept. of geography, university of padova, via del santo 26 35123 padova 2 dept. of biology, university of padova, via g. colombo 3 35131 padova abstract this work presents the first results of a multidisciplinary study in the flood plain of the piave river located ne of the venice lagoon. the aim of the work is to reconstruct the late quaternary geomorphological evolution of the area. this study is part of a wider research on the veneto-friuli plain based on geomorphological surveys, remote-sensing, sediment analyses, archaeological and historical map analyses. in the frame of this study, three cores of 20 m depth were collected along a n-s transect 20 km long between san donà di piave and the coast of the adriatic sea. the transect crosses the present course of the piave river and its fluvial ridge, while the corings were performed on the surface of old flat marshes, now reclaimed. pollen-stratigraphical data and 14c dates are presented for the intermediate core of palazzetto. the results of radiocarbon dating indicate that the sequence spans the last glacial maximum (lgm) and the holocene. at the base of the sequence, a peat layer (21,250±150 yr bp) is characterised by dominance of cyperaceae (pollen, epidermal and roots fragments, fruits) as many other peat layers formerly described by other authors in the veneto and friuli plain. fine fluvial sediments attributed to the piave river bury the basal peat. the changes in the local plant communities from fresh water to brackish/salt water communities have been recognised at the depth of ca. 6 m. this level testifies the flandrian transgression not yet investigated in the san donà di piave area. the geochronological dating and the pollen analysis of the three cores will let us know the dynamic of the ingression of the sea at ne of the venice lagoon. at the top of the core the pollen assemblage of a peat layer (500±70 yr bp) suggests the presence of a marsh environment. riassunto ricostruzione paleoambientale dell’area planiziale costiera del basso piave dall’ultimo massimo glaciale all’olocene. analisi polliniche preliminari di una carota di 20 m di sedimenti fluviali e lagunari. questo contributo riporta i primi risultati di un’indagine multidisciplinare condotta nella pianura alluvionale del fiume piave a ne della laguna di venezia. lo scopo della ricerca è di comprendere l’evoluzione geomorfologica dell’area nel quaternario recente. essa è parte di un vasto studio della pianura veneto-friulana, condotto attraverso indagini geomorfologiche, remote-sensing, analisi dei sedimenti, analisi di mappe storiche e di reperti archeologici. in questo contesto sono stati eseguiti tre carotaggi fino a 20 m di profondità, collocati lungo un transetto n-s della lunghezza di una ventina di km tra san donà di piave e la costa settentrionale del mare adriatico. il transetto attraversa l’attuale corso del fiume piave e il suo dosso fluviale. i carotaggi sono stati eseguiti in corrispondenza di antiche aree paludose, oggi bonificate. in questo lavoro vengono presentati i risultati dello studio della sequenza di palazzetto, collocato circa a metà del transetto. lo scarso contenuto pollinico dei sedimenti analizzati limita l’utilizzo dei dati pollinici alla ricostruzione dei cambiamenti avvenuti nell’ambiente di sedimentazione. i risultati della radiodatazione di quattro livelli di sedimenti organici fanno ritenere che la sequenza si sia deposta tra l’ultimo massimo glaciale e l’olocene recente. alla base sono stati individuati strati torbosi (21.250±150 a bp) a prevalenti cyperaceae (polline, frammenti di radici e di epidermidi, frutti), caratterizzati dalla stessa flora pollinica di altri depositi torbosi, già descritti da vari autori in sequenze della pianura veneta e friulana, di età compresa tra i 18.000 e i 22.000 anni bp. le torbe basali sono ricoperte da depositi sabbiosi e limosi fluviali attribuiti alle esondazioni del piave e depostisi in un breve periodo di tempo, circa 2000 anni. le analisi polliniche indicano un radicale cambiamento nelle comunità vegetali locali nei sedimenti argillo-torbosi collocati a circa 6 m di profondità (6520±150 a bp): comunità vegetali di acqua dolce sono sostituite da comunità tipiche di ambienti di acque salate/salmastre. questi sedimenti sono la prima testimonianza della trasgressione flandriana nella zona di san donà di piave. alla sommità della sequenza è stato analizzato uno strato torboso di età radiometrica di 500±70 a bp (cal ad 1300-1500); l’associazione pollinica esaminata suggerisce la presenza locale di comunità di piante prevalentemente erbacee di palude e nessun indizio di insediamenti umani. key words: late glacial maximum, holocene, stratigraphy, geomorphology, pollen and spores analysis, piave river, north adriatic. parole chiave: ultimo massimo glaciale, olocene, stratigrafia, geomorfologia, analisi di polline e spore, fiume piave, nord adriatico. il quaternario italian journal of quaternary sciences 1166(1bis), 2003, 183-192 iinnttrroodduuccttiioonn the paleoenvironmental reconstruction of the venice area has been the aim of several multidisciplinary researches (bortolami et al., 1977; castiglioni & favero, 1987; blake et al., 1988; correggiari et al., 1996; mullenders et al., 1996; serandrei barbero et al., 2001; kent et al., 2002). the main task of these studies is the improved knowledge of subsidence phenomenon in the past and the effects of human activities on its evolution. the nearby coast located ne is poorly known, even if its evolution in the past influenced or has been influenced by the hydrological conditions of the venice area. therefore a wider research on the veneto-friuli plain has started some years ago. it is based on geomorphologic surveys, remote-sensing, sediment analyses, archaeological and historical map analyses (bondesan et al., 1998; bondesan, 2000; bondesan & furlanetto, 2000; bondesan et al., 2002a; bondesan et al., 2002b; ghedini et al., 2002). in the framework of this study, we collected three continuous cores along a 20 km long n-s transect that goes from san donà di piave to the coast of the adriatic sea (fig. 1), hopefully contributing to the study of evolution in the venetian coastal plain of the past by means of pollen and spore analysis. in this paper 14c dates and pollen-stratigraphic data are 184 a. bondesan et al. presented for the intermediate core of palazzetto. the studied area is located along the modern course of the piave river, at the north-eastern border of the lagoon of venice, into the coastal plain between sile and livenza rivers. the territory is characterised by a dense hydrographical network, where the main rivers (piave, sile and livenza) which are south-eastwards oriented, flow in connection with the artificial canals dug in xiii century by the republic of venice. due to the hydraulic reclamation, a closed network of small canals and ditches crosses the whole plain. there are many evident traces due to the ancient shorelines, back from the present coastline; from them we can establish the existence of at least two paleo-piave deltas, now extinct and buried. the plain surface is mainly constituted by agricultural fields, most of which laying below the sea level: the lower elevations are found northern of caorle (livenza mouth), where they locally reach values lower than 4 m below sea-level. higher heights mainly stand along fluvial ridges and old dunes closed to present littoral. all this territory was scattered by wide swamps, marshes and lagoons until the end of xix century when the reclamation started, joined with a strong reduction of old dunes and fluvial ridges. it is well known that during the last strong cold pulsation of the pleistocene the sea level dropped more than one hundred metres below the present one. because of the shallowness of the adriatic sea, the coast in the lgm shifted towards south for more than 200 km to the latitude of ancona. the present north adriatic sea was then a fluvial plain where all the rivers of the po plain converged and perhaps joined. the venetian plain was then rich of marshes and swamps that left extended layers of peat dating from ca. 22,000 to 18,000 yr bp (bondesan et al., 2002b). at the same time, huge glaciers flowed south from the alps and the majority of them reached the plain. the glacier of the piave river basin had two snouts at quero and vittorio veneto where it left its moraines. an end moraine of the vittorio terminus has been dated to 17,670 ± 320 yr bp (bondesan, 1999); from that date onwards the glaciers started to retreat as a consequence of the climatic improvement. along with the glaciers retreat, the sea level started to lift and the coast shifted again to the north (flandrian transgression). according to brambati (1985) the coastline reached a position similar to the present one at about 7-6000 yr bp, while correggiari et al. (1996) fixed the maximum sea ingression around 5000 calendars years bp, by the dating of lagoonal sediments. the transgression probably joined with changes in the rivers hydrological state, and this led to an instability of the lower reaches of the rivers that could be affected by avulsions as happened for the rhine and mose delta as described by stouthamer (2001). an avulsion node is that of san donà di piave, from which starts the fluvial ridge crossed by the transect described in this paper. ggeeoommoorrpphhoollooggiiccaall oouuttlliinneess the plain belonging to the piave river (fig. 2) is a complex form, generated by deposition and erosion phenomena mainly due to fluvial sediments, with contributions of fluvio-glacial and marine deposits. looking from the point where the mountains merge into the plain, at the height of nervesa, we found a progressive change from the large fan of the foothills to the low plain and finally to the proper coastal plain, this last one being the result of the interference of marine and fluvial dynamics. looking at the altimetry the surface lies between 80 m above sea level at nervesa and 4 m below sea level along the coast. the system of the high plain is formed by a sequence of great, flat, gravelly alluvial fans that lie one overlaid to the other on the prealpine border (bondesan, 2000). the nervesa fan, which constitutes the nervesa unit, is furrowed by the present piave river bed (bondesan et al., 2002b); it started to form soon after the upper-pleistocene fluvial diversion of the piave river from the montebelluna to the nervesa course. the fan is not very steep, showing a dip of 3-4‰ at the apex and 1.5-2‰ uphill of the alignment treviso-ponte di piave; downhill it is less than 1‰. its gravelly sandy sediments extend eastward up to oderzo, coming close to river livenza. there are five main recognizable fluvial ridges and all of them start from the fan apex at nervesa; they are related to paleo-piave beds and to the present fluvial ridge of the piave river, which is continuously elevated on the plain as far as the mouth. almost all the traces, visible on aerial photographs, situated on the left wing of the nervesa fan, can be classified as braided streams; they have been dated from 4170±60 yr bp to present day. descending towards the sea, the low plain is found where the hydrographical network becomes denser, the gradient decreases and the sediments become finer. here we find fluvial ridges both along present river courses and also along abandoned rivers. sometimes, a small watercourse interprefig.1 location map of the studied area. 185paleoenvironmental reconstruction from lgm ... ted as relict hydrography remains on the top of the ridge. this process leads to the formation of a network of ridges surrounding closed or semi-closed hollows where the drainage is barred. s. donà di piave constitutes an avulsion node, from which different watercourses in different times depart. there are four main ridges branching out from this point across the coastal plain. the western one is the piave vecchia ridge (pv in fig. 2), rimming the venice lagoon border. eastwards, the taglio da re ridge (tr in fig. 2) gains the cavetta channel, back of jesolo; it is the outreach of a diversion channel excavated by the venetians in 1534. nowadays the ridge is overflowed by a scant reclamation channel. the present main piave river bed is artificially excavated and it gets eraclea flowing straight for some kilometres. it follows the left flank of the ridge (pc in fig. 2), 3 km wide and 3 m height over the surrounding plain, probably created by a former ancient piave. it shows branches and crevasse splays with traces of ancient channels well documented in antique and modern maps. the piovan (or piveran) channel (cp in fig. 2) is very interesting: it flows along a great ridge starting from s. donà di piave and it turns southeast after the confluence with the grassaga channel toward stretti. the ridge is 3 km wide and 2 m high at s. donà di piave, but it becomes narrow and flat as far as it looses any morphological evidence. the via annia, an ancient roman way, follows the path of the ridge and changes its direction when it crosses the mound through a roman bridge whose remains were found along the grassaga channel; then the ridge follows on to the archaeological site of cittanova. the fluvial ridges define large low-laying interfluvial areas, where paleo-river beds and paleo-lagoon channels are clearly visible on aerial photo-fig. 2 geomorphological sketch map of the piave river plain. 186 graphs. the medieval and modern ingression of the lagoon is marked along the stretch north of taglio del sile, going along the line linking s.donà di piave to boccafossa (livenza river) (castiglioni & favero, 1987; murst, 1997). the lagoon deposits spill at the surface and we assert they are very recent. organic samples of surface lagoon sediments gave a geo-chronological age of 1200±190 yr bp (utc 7801), 955±55 yr bp (rome – 1180) and 658±39 yr bp (utc 7802) (personal communication of henk berendsen, 1998; bondesan et al., in press-b). these data confirm that the lagoon sediment sealed the depressions between the older main fluvial ridges in historical times. along the coast we find the littoral unit (bondesan et al., 2002b) constituted by ancient coastlines and alignment of paleo-dunes, most of them now artificially levelled. the inner traces could be connected with the littoral deposits formed at lio maggiore and lio piccolo which are dated about 6500 yr bp (blake et al., 1988). the ancient coastlines are distributed over the whole district between rivers piave and sile. the general distribution of alignments shows at least four zones, each representing an advancing phase of the littoral, followed by an erosion event in all likelihood. the coastal stretch defines a cuspate delta, probably asymmetric, well developed in the area nowadays occupied by the piave mouth, but perhaps much more protruded into the sea, and lately interested by an erosion phase. the development of the older paleo-delta is ascribed to the upper atlantic, while during the transition atlanticsubboreal, the right portion of the piave paleo-delta might have started. the formation of the more recent cuspate delta, whose traces are scarce, seems to have started in the second part of the subboreal (bondesan et al., in press-a). mmaatteerriiaallss aanndd mmeetthhooddss the continuous core of palazzetto was collected using a mechanic sampler, down to a depth of 21.71 m. the lithology of sediments is indicated at the left side of the diagrams, according to the troels-smith system. we selected 42 samples (2 cm3). the uppermost 80 cm (agricultural soil and sand) and the sediments from 6.96 m to 10.10 m and from 18.49 m to 19.39 m (sands) were not considered because unsuitable for pollen conservation. tablets of a known concentration of lycopodium spores were added to each samples prior to preparation so that fossil pollen concentration could be estimated. samples were treated with hcl (37%), cold hf (50%) and boiling naoh (10%). a sieve of mesh of about 200 µm was employed to isolate macrofossil and epidermal fragments from peat sediments. in the end, samples were acetolysed. residues were mounted on slides, in glycerine. all samples were analysed to count pollen and spores of ferns, bryophytes, algae and fungi; epidermal fragments were only identified. identification and counting were made with a magnification of 400x and critical determination at 1000x. identification was aided by a modern pollen and spore reference collection, and illustrations and keys including reille (1992; 1998), punt (1976), punt & clarke (1980; 1981; 1984), punt et al. (1988) and moore et al. (1991). “saccate grains” indicates broken pollen grains of the pinaceae family, but their genus or species are indeterminable. type 303, is described by van geel et al. (1981). they do not identify it, but they report that it mainly occurs in the late glacial (younger dryas) and early holocene sediments. we record high values of type 303 in peat that was rich of mosses fragments; therefore we put forward the hypothesis that one/more members of bryophytes could produce it. studies are in progress. type 200 is described by van geel et al. (1989) and kuhry (1997). the zygospores of the zygnemataceae are described by van geel (1978), van geel & van der hammen (1978) and van geel et al. (1981). identification of some epidermal fragments was aided by a modern collection. pollen counting mostly continued until pollen sum (trees+shrubs+upland herbs) reached 100÷250 units, according to the pollen content of the sample. the percentage of helophytes and hydrophytes, of pterydophytes, of bryophytes, of algae, of fungi and of foraminifera remains, respectively, is calculated over the pollen sum added to each group’s total. unknown grains did not show the characteristic features of pollen grains; therefore they were not included in the pollen sum. indeterminable grains (degraded, corroded, broken, pyritized) have been counted, their percentage is calculated over the sum of all pollen grains (identified, indeterminable and hidden). the pollen diagrams were calculated and drawn using the programs tilia and tilia.graph (grimm, 1990). we present a pollen preservation diagram (fig. 3), a pollen and spore concentration diagram (fig. 4), a pollen and spore percentage synthetic diagram (fig. 5), a pollen percentage diagram of selected taxa (fig. 6) and a pollen percentage diagram of helophytes and hydrophytes (fig. 7). when terrestrial pollen sum didn’t reach 100 units, we have marked the sporomorphs findings with a plus sign in the diagrams. the occurrence of epidermal fragments has been indicated with circle signs. four 14c dates were obtained from sediment associated with a specific layer identified from the pollen diagrams (tab. 1). radiocarbon dating was conducted at the beta-analytic inc. miami – florida. tab. 1 radiocarbon dates from palazzetto core. lab. reference sample depth 14c age method (cm) (yr bp) beta 173728 76-80 500±70 standard beta 168127 581-609 6520±50 standard beta 168128 1323-1333 19850±120 standard beta 168129 2049-2059 21250±150 standard rreessuullttss we have analysed 42 samples from the palazzetto core (fig. 3), but 15 samples were virtually free of pollen (pollen sum<10 grains) and 8 samples were rather poor in pollen (pollen sum<100 grains). pollen concentration is generally low in the a. bondesan et al. 187 part of the core the pollen preservation is poor, with up to 40% indeterminable pollen, probably resulting from physical transport of the pollen grains in the silt sediments. grains infilled with crystals of pyrite (pyritized) are continuously present in the upper part of the core documenting chemically-reducing alluvial environment (berglund & ralska-jasieviczowa, 1986). the development of local and upland vegetation has not been continuously documented in the sequence because of the presence of sterile sand layers (see lithology), and because of the scarcity of pollen grains in fluvial sediments. nevertheless indicative local environments may be reconstructed from the following stratigraphical-pollen data to recognise transgressive trend of the coast line at the north of venice lagoon. the chronology of the sequence is based on radiocarbon dates (tab.1). hereafter the most important features of the pollen analysis are described. 2211..4444÷÷1188..1199 mm. the basal peat (20.59÷20.34 m) contains a high percentage of uplands herbs (nap) including poaceae (53% average), artemisia, that reaches its highest value for the entire record (12%), chenopodiaceae, asteroideae undiff. and thalictrum. trees and shrubs are represented by low percentage: pinus (6% average), betula, ephedra fragilis type, larix type, abies, fagus sylvatica type and acer campestre type. the local wetland vegetation is mostly represented by cyperaceae pollen (93% of helophytes+hydrophytes fig. 7) and by aerial fragments, roots and fruits of carex species. we also find pollen of lemna, potamogeton subg. p. type, nuphar, and sparganium emersum type. high percentage of algal spores (zygnema type) is recorded in this layer. the presence of mosses in the local environment is indicated by the highest value (67%) of spore percentage in the entire sequence and by many fragments of leaves and little stems. the dominant type of spores is type 303. upland local vegetation is dominated by populus (16%) that could occur in the area surrounding the depressions, among grassy vegetation of poaceae. the pollen and bryophytes concentrations decrease in the peat layer paleoenvironmental reconstruction from lgm ... fig. 4 pollen and spores concentration diagram of palazzetto core. fig. 3 pollen preservation in the sediment of palazzetto core (total pollen sum: trees, shrubs, upland and wetland herbs, indeterminable, hidden pollen grains). sequence: it reaches the value of about 100 x 103 grains/cm3 only at the depth of 20.34 m (peat) and at the depth of 5.84 m (organic clay) (fig. 4). we believe that the scarcity of pollen grains was caused by a fast rate of silt and clay sedimentation in the floodplain environment. in fact unsuitable conditions of preservation are unlikely because of the good state of the rare grains we found, almost from the bottom to the depth of 5.84 m and the percentage of indeterminable grains (degraded, corroded, broken and pyritized) surpassing 20% only in the sample at the depth of 13.00 m (fig. 3). in the upper 188 a. bondesan et al. fig. 5 pollen and spore percentage synthetic diagram of palazzetto core. at 18.34÷18.39 m but the pollen assemblage does not change. the fungal spore concentration increases. the dominant type is type 200. the occurrence of pollen in the next layers up to 13.84 m is very low. 1133..8844÷÷1122..8811 mm. nap continues to dominate the pollen assemblage. the higher value of total pollen concentration (60 x 103 grains/cm3) corresponds with a peat layer (13.18÷13.16 m). poaceae are the dominant taxon (maximum value 85%). cyperaceae’s percentage shows a declining trend. the sediments at the top contain the highest percentage of hydrophytes (61% of helophytes + hydrophytes). instead artemisia and chenopodiaceae percentages decrease. arboreal taxa are mostly represented by pinus (p. cembra, p. mugo/p. sylvestris) and “saccate grains”. populus and salix show increasing percentages, while alnus is rare. picea and castanea sativa type are recorded for the first time. 1122..8811÷÷1100..0000 mm. nap continues to dominate the pollen assemblage and poaceae are the dominant taxon: the highest concentration value corresponds to a layer of organic clay at the depth of 11.54÷11.52 m. cyperaceae pollen percentage increases. hydrophytes show lower concentration and percentage values if compared to the previous layers. we do not find any significant changes in the other herbaceous pollen taxa, as artemisia, chenopodiaceae, asteroideae undiff. and cichorioideae undiff. pinus undiff. prevails even if with low percentages; betula, picea, larix type, abies are present with only few pollen grains. 77..0000÷÷33..7766 mm. a 3 m thick layer of sand separates these layers by the previous ones. the pollen content of the samples from 7.00 m to 5.76 m is very low (<10 grains per slide). we have identified few pollen taxa: pinus undiff., picea, larix type, salix, poaceae and cyperaceae. the occurrence of 3 inner organic linings of ammonia beccarii at the depth of 6.20 m, is very interesting, mostly because of the poorness of samples. we have continuously found it from this layer up to the top of the core. the pollen assemblage of the organic clay samples (5.86÷5.78 m) is characterised by the dominance of nap as in the previous layers, but it shows some changes in pollen taxa distribution. some of the previously most important taxa decrease: helophytes and hydrophytes are rare, poaceae decrease to a percentage values of about 10%, chenopodiaceae pollen is abundant for the first time: it attains a maximum of 44%. new taxa of plumbaginaceae are found: limonium vulgare type a and armeria maritima type a and b, that include species living in salt marshes as l. narbonense miller. plumbaginaceae undiff. pollen attains its highest frequency in the core (7%). arboreal pollen does not dominate in the pollen assemblage but some taxa show their maximum concentration value in the core: quercus robur group, corylus, fagus sylvatica type, pinus undiff., “saccate grains”, betula. carpinus type firstly occurs. castanea sativa type (<1%) is continuously represented from here up to the top of the core with values ranging around 2-3%. the inner organic lining of ammonia beccarii (“other” in fig. 5) attains a maximum concentration value in the core. silty grey clay sediments constitute the upper layer and they are virtually barren of sporomorphs. 33..7766mm÷÷11..0088 mm. the pollen assemblages are characterised by: i) the dominance of ap; ii) the first notable increase of several broad-leaf trees taxa; iii) the contemporaneous presence of quercetum s.l. elements, of pinus (decreasing) and betula, and of picea, fagus and abies. ap percentage value attains 90% at the bottom of these layers, but it shows a declining trend in the upper layers. the palynological richness attains its maximum value of 19 arboreal pollen taxa and 14 herbaceous pollen taxa. riparian plants, such as alnus, populus and salix, show increased percentages. poaceae slightly increase from the bottom to the top. 189paleoenvironmental reconstruction from lgm ... there is a reduction of helophytes and hydrophytes. indeterminate grains (mechanically damaged) and “saccate grains” are continuously found with the highest concentration and percentage values at the top of the core. there is a notable reduction of pollen content at the top: total pollen concentration drops to 8 x 103 grains/cm3. ammonia beccarii inner organic linings are found in each sample. 11..0088÷÷00..8822 mm. the pollen concentration increases at the top of the core, but deciduous plants disappear except for populus and salix. helophytes and hydrophytes pollen prevail on the other taxa. the spores of pterydophytes and bryophytes are very abundant. we do not find pollen that indicates the nearby presence of human activities. iinntteerrpprreettaattiioonn ooff rreessuullttss the lithology of sediment, along with pollen and macrofossil records point to the fact that the sedimentation environment at the bottom of palazzetto core, changed from an open water stage (22.00÷21.00 m), probably with a high rate of sedimentation, to a mire stadium (20.49÷20.34 m), with carex species and brown mosses at 21,250±150 yr bp. the presence of a water table close to the surface or other geomorphological conditions, i.e. shallow closed depressions or lasting snow cover, are suggested by the ecological optimum of some carex species (c. ferruginea scop., c. limosa l., c. rostrata stokes), which is characterised by a good water availability (buffa & sburlino, 2001; bragazza, 1999). the assemblage of spores of zygnema type and aquatic taxa (lemna, potamogeton, callitriche, and nuphar) pollen points to the local occurrence of pools in some shallow depression of the mire. the conditions of sedimentation change significantly at the depth of 19.30 m. silt and sand layers indicate an active nearby fluvial system. in the upper peat layer (18.34÷18.39 m) the occurrence of fungal type 200 could be indicative of marked table fluctuations during the growing season and of relatively dry microhabitats in temporary desiccating bottoms of pools. the pollen concentration and assemblage are typical of a cold and dry climate, that corresponds to the radiocarbon dating results. the low pollen concentration found in the analysed sediments until 13.84 m could be linked to the high rate of sedimentation suggested by the radiocarbon dates. from the depth of 13.84 m the local conditions gradually change: the total pollen concentration increases in concomitance with the development of a new mire stadium (13.16÷13.18 m). initially high percentage and concentration values of aquatic plants pollen suggest that aquatic conditions prevail. poaceae (perhaps phragmites sp.) and cyperaceae stands, grow around the basin but they gradually fill it up, until the formation of a mire (13.16÷13.18 m). the lithology of sediments from 12.81 m to 7.00 m (roughly represented in this paper) suggests that the sedimentation environment changed many times, but we didn’t note significant changes in pollen associations. from the age of 6520±150 yr bp (6.09÷5.81 m), many records suggest local development of a lagoon environment. plumbaginaceae (limonium vulgare type a and armeria maritima type b include l. narbonense miller), poaceae, cheno-podiaceae and asteraceae asteroideae undiff. represent the local vegetation. we suppose that modern analogue could be found in pioneer vegetation of silt and silty sands, living in salt marshes of the lagoons in the northern adriatic coast. lymonium narbonense miller, spartina maritima (curtis) fernald and some species of chenopodiaceae form the association limonio narbonensis-spartinetum maritimae that changes in limonio narbonensispuccinellio festufig.6 pollen percentage diagram of selected taxa of palazzetto core. ciformis when the ground level increases (caniglia et al., 1997). pollen morphology does not allow any identif ication of spartina marit ima (curtis) fernald or puccinellia palustris (seen.) hayek or different species of chenopodiaceae; therefore the stage of vegetation dynamics is not given to know. studies are in progress to recognise epidermal fragments of roots. the presence of ammonia beccarii inner organic linings is another important feature of the zone, because a. beccarii is the dominant taxon among the foraminifera that today are living in the water of venice lagoon (serandrei barbero et al., 2001). its occurrence is indicative of an open salt/brackish water environment too. upland vegetation abruptly changes: we note that pollen percentage of pinus is overtaken by pollen percentage of thermophilous broad-leaf plants. rizzi longo (1996) reviewed pollen records from friuli plain sequences. she underlies that pinus decreases during the passage from pre-boreal to boreal period and the association of oaks and other broad-leaf trees grows. in the plain belt mixed oak forest dominates until historical times. radiocarbon dating and the results of our preliminary pollen analysis is in full accordance with these data. from the depth of 3.76 m an open water environment covered the area and upland forest vegetation was probably near the banks: riparian plants, such as alnus, salix and populus lived near the basin, mixed oak forest covered the surrounding areas. the low percentage of cyperaceae, aquatic plant pollen, and fresh-water algal spore, and the constant presence of ammonia beccarii indicate a salt/brackish quality of water. dominance of quercetum s.l. decreases towards the top of the core; castanea and corylus pollen are constantly present and do not change their trends. these are common features of friuli plains pollen diagrams and they are dated to historical times (rizzi longo, 1996). drastic changes in pollen association suggest the development of new environmental conditions at the age of 500÷70 yr bp (cal ad 1400 to 1450). the disappearance of tree pollen and the consistent presence of pterydophytes spores could be the signs of the late middle age human activity in the area (cagnin, 2000). the presence of type 200 fungal spore indicates that the area was subject to marked fluctuations of the water table, during the growing season. the decline in ammonia beccarii and increased frequencies of freshwater plants suggest a lower influence of seawater. ccoonncclluuddiinngg rreemmaarrkkss the results from radiocarbon dating suggest that the palazzetto sequence spans the lgm and the historical times. the depositions of silt and sand layers interrupted the pollen and lithological sequence, and therefore the history of the local environment is fragmented. probably the studies in progress of the other two cores (ca’ fornera and fiorentina) will add further elements to the history of the area. cyperaceae peat layers were deposited at the bottom of the core during the end of the last glacial period. these layers could be correlated with similar peat layers from the veneto and friuli plain, already described by other authors (bortolami et al., 1977; mullenders et al., 1996; serandrei barbero et al., 2001; bondesan et al., 2002b): studies are in progress. four events of fluvial sedimentation, attributed to the piave river, follow the deposition of the basal peats at the depth of about 19 m, 17.5 m, 15 m and 11 m. they occurred before the beginning of the holocene. the last important fluvial sedimentation (10÷7 m) occurs before the development of brackish/salt communities in the area, at the age of ca. 6520±150 yr bp. pollen and spore association at the depth of ca. 6 m, documents the development of a lagoon environment, connected to the flandrian transgression not yet described in the san donà di piave plain. in the nearby venice lagoon, first lagoon sediments after the flandrian transgression have been dated to 5090±100 yr bp by serandrei barbero et al. (2001). the geochronological dating and pollen analysis of the three cores will let us verify the dynamics of the ingression of the lagoon. aacckknnoowwlleeddggeemmeennttss we would like to thank the anonymous referees for their comments and useful suggestions on a previous draft and dr. alessandra asioli for the identification of ammonia beccari inner organic lining. we thank dr. paolo mozzi for the given help in core analysis. 190 a. bondesan et al. fig. 7 helophytes and hydrophytes percentage diagram of palazzetto core. rreeffeerreenncceess berglund b.e. & ralska-jasiewiczowa m. (1986) pollen analysis and pollen diagrams. in: handbook of holocene palaeoecology and palaeohydrology. berglund b. e. (ed.), john wiley & sons, chicester, p. 455-484. blake h., bondesan a., favero v., finzi e. & salvatori s. (1988) cittanova heraclia 1987: risultati preliminari delle indagini geomorfologiche e paleogeografiche, quad. arch. del veneto, 44, p. 112135. bondesan a. (1999) una nuova data 14c nell’anfiteatro morenico di vittorio veneto e la costruzione del suo sandur (pianura del f. meschio), viii convegno glaciologico italiano bormio, 9-12 settembre 1999, risposta dei ghiacciai alpini ai cambiamenti climatici, seminario murst: “risposte dei processi geomorfologici alle variazioni climatiche in ambiente montano”. bondesan a. (2000) i fiumi, le lagune e il mare. la geomorfologia della laguna, in “il piave”, cierre, verona, p. 76-82. bondesan a., calderoni g. & rizzetto f. (in press-a) geomorphologic evolution of the lower piave river, suppl. geogr. fis. dinam. quat. in press. bondesan a., caniato g., valerani v. & zanetti m. (eds) (1998) il sile, cierre, unesco, verona, pp. 357. bondesan a., caniato g., valerani v. & zanetti m. (eds) (in press-b) il brenta, cierre, verona. bondesan a. & furlanetto p. (2000) l’uomo e le acque: cartografia storica e indagine geomorfologica a confronto, in “il piave”, cierre, verona, p. 87-91. bondesan a., bertani b., fontana a., furlanetto p. & primon s. (2002a) carta della fotointerpretazione e dei siti archeologici della provincia di venezia tra i fiumi livenza e tagliamento, cd-rom edito dal magistrato alle acque consorzio venezia nuova. bondesan a., mozzi p. & calderoni g. (2002b) l’assetto geomorfologico della pianura veneta centro-orientale: stato delle conoscenze e nuovi dati, scritti in ricordo di giovanna brunetta, dip. geogr. univ. padova, p. 19-38. bortolami g.c., fontes j., markgraf v. & saliege j.f. (1977) land, sea and climate in the northern adriatic region during late pleistocene and holocene, palaeogeography, palaeoclimatology, palaeoecology, 2211, p. 139-156. bragazza l. (1999) spatial patterns of plant species in a poor mire on the southern alps (italy), plant biosystems, 113333,, no. 1, p. 83-92. brambati a. (1985) modificazioni costiere nell’arco lagunare dell’adriatico settentrionale, antichità altoadriatiche, studi jesolani, 2277, p. 13-47. buffa g. & sburlino g. (2001) carex ferruginea grasslands in the south-eastern alps, plant biosystems, 113355, no. 2, p. 195-206. cagnin g., (2000) “per molti e notabel danni i qual riceve campi, pradi, ville e vigne per lo corso macor de la piave”. il difficile rapporto tra un fiume e il suo territorio nel medioevo”, in “il piave”, cierre, verona, p. 212-227. caniglia g., contin g., fusco m., anoè n. & zanaboni a. (1997) confronto su base vegetazionale tra due barene della laguna di venezia, fitosociologia, 3344, p. 111-119. castiglioni g.b. & favero v. (1987) linee di costa antiche ai margini orientali della laguna di venezia e ai lati della foce attuale del piave, ist. ven. ss. ll. aa., rapporti e studi, 1100, p. 17-30. correggiari a., roveri m. & trincardi f. (1996) late pleistocene and holocene evolution of the north adriatic sea, ii quaternario, 99, no. 2, p. 697-704. ghedini f., bondesan a. & busana s. (eds) (2002) la tenuta di ca’ tron. ambiente e storia nella terra dei dogi, cierre, verona, pp. 240. grimm e.c. (1990) tilia and tilia.graph, pc spreadsheet and graphics software for pollen data, inqua working group data handling methods newsletter 44, p. 5-7. kent d.v., rio d., massari f., kukla g. & lanci l. (2002) emergence of venice during the pleistocene, quaternary science review, 2211, p. 1719-1727. kuhry p. (1997) the palaeoecology of a treed bog in western boreal canada: a study based on microfossils, macrofossils and physico-chemical properties, rev. palaeobot. palynol., 9966, p. 183224. moore p.d., webb j.a. & collinson m.e. (1991) pollen analysis, ii ed., blackwell science, oxford, pp. 216. mullenders w., favero v., ciremans m. & dirickx m. (1996) analyses polliniques de sondages a venise (ve-i, ve-i bis, ve-ii), in "pleistocene palynostratigraphy". gullentips f. (ed), aardk. mededel., 77, p. 87-117. murst (1997) carta geomorfologica della pianura padana, 3 fogli, scala 1:250.000, s.el.ca., firenze. punt w. (1976) the northwest european pollen flora, i. rev. palaeobot. palynol., 1177,, 1199 e 2211. elsevier, amsterdam, pp. 145. punt w., blackmore s. & clarke g.c.s. (1988) the northwest european pollen f lora, v. rev. palaeobot. palynol., 5577, elsevier, amsterdam, pp. 154. punt w. & clarke g.c.s. (1980) the northwest european pollen f lora, ii. rev. palaeobot. palynol., 2266, elsevier, amsterdam, pp. 265. punt w. & clarke g.c.s. (1981) the northwest european pollen f lora, iii. rev. palaeobot. palynol., 3333, elsevier, amsterdam, pp. 138. punt w. & clarke g.c.s. (1984) the northwest european pollen flora, iv. rev. palaeobot. palynol., 4422, elsevier, amsterdam, pp. 369. reille m. (1992) pollen et spores d’europe et d’afrique du nord, marseille, pp. 520. reille m. (1998) pollen et spores d’europe et d’afrique du nord, supplement 2, marseille, pp. 521. rizzi longo l. (1996) palynological evidence of the forest vegetation of the friuli plain, allionia, 3344, p. 287-295. serandrei barbero r., lezziero a., albani a. & zoppi u. (2001) depositi tardo-pleistocenici ed olocenici nel sottosuolo veneziano: paleoambienti e cronologia, il quaternario, 1144, no. 1, p. 9-22. stouthamer e. (2001) holocene avulsions in the rhine-meuse delta, the netherlands, e. stouthamer, utrecht, pp. 223 191paleoenvironmental reconstruction from lgm ... van geel b. (1978) a palaeoecological study of holocene peat bog sections in germany and the netherlands, based on the analysis of pollen, spores and macroand microscopic remains of fungi, algae, cormophytes and animals, rev. palaeobot. palynol., 2255, p. 1-120. van geel b., bohncke s.j.p. & dee h. (1980-1981) a palaeoecological study of upper late glacial and holocene sequence from “de borchert”, the netherlands, rev. palaeobot. palynol., 3311, p. 367448. van geel b., coope g.r. & van der hammen t. (1989) palaecology and stratigraphy of the lateglacial type section at usselo (the netherlands), rev. palaeobot. palynol., 6600, p. 25-129. van geel b. & van der hammen t. (1978) zygnemataceae in quaternary colombian sediments, rev. palaeobot. palynol., 2255, p. 377-392. 192 a. bondesan et al. imp.gioia_schiattarella caratteri morfotettonici dell’area del valico di prestieri e dei monti di lauria (appennino meridionale) dario gioia1 & marcello schiattarella1 1 dipartimento di scienze geologiche, università della basilicata, potenza riassunto: d. gioia & m. schiattarella, caratteri morfotettonici dell’area del valico di prestieri e dei monti di lauria (appennino meridionale). (it issn 0394-3356, 2006). i monti di lauria, ubicati ad occidente del bacino del mercure – che li separa dai vicini rilievi dalla catena del pollino rappresentano un alto strutturale di carbonati mesozoici la cui morfoevoluzione è stata fortemente controllata dalla tettonica quaternaria. a sud della dorsale compresa tra gli abitati di lauria e castelluccio si sviluppa per circa 15 km il “corridoio morfologico” del valico di prestieri, nel quale trovano posto sedimenti continentali quaternari organizzati in più corpi deposizionali. in questa nota viene proposto un quadro stratigrafico e morfostrutturale dell’intera area, unitamente alla ricostruzione della sequenza morfo-tettonoevolutiva neogenico-quaternaria. la primitiva struttura contrazionale neogenica risulta smembrata dalla riattivazione mediopleistocenica, in regime estensionale, di un’associazione di faglie originariamente prodotta durante il pliocene superiore – pleistocene inferiore in una zona di taglio orientata all’incirca n120°. sono stati riconosciuti diversi momenti di crisi tettonica nel pleistocene e periodi di quiescenza durante i quali ha avuto luogo il modellamento in corrispondenza del paleolivello di base locale dell’erosione di superfici erosionali più o meno estese e la genesi di corpi sedimentari con top deposizionali a bassa pendenza. l’utilizzo di simili indicatori morfotettonici – ai quali è stato possibile attribuire un’età per correlazione geomorfologica con i vicini bacini del mercure e del sinni ha permesso di valutare i tassi di sollevamento regionali e locali dell’area e la velocità di scivolamento delle principali faglie. i tassi del sollevamento regionale vanno ad assestarsi su valori di circa 1 mm/a mentre quelli locali sono corrispondenti in linea di massima ai tassi di attività delle faglie e raggiungono i valori più elevati (0,5-0,6 mm/a circa) al passaggio pleistocene inferiore–medio, in coincidenza dell’attivazione della tettonica estensionale ad asse ne-so. l’entità dell’esumazione quaternaria legata all’erosione lineare, calcolata attraverso il tasso di incisione delle superfici di spianamento relitte, risulta nettamente minore rispetto a quella necessaria per smantellare le volumetrie responsabili del carico tettonico ipotizzabile per l’area di studio. la necessità di invocare altri meccanismi di esumazione permette allora di collegare le faglie a basso angolo con cinematica normale o trastensiva, rilevate lungo i rilievi di monte la spina e monte zaccana, a fenomeni, probabilmente di età pliocenica, di denudamento tettonico dell’orogene. abstract: d. gioia & m. schiattarella, morphotectonics of the valico di prestieri area and adjacent lauria mts (southern appennines). (it issn 0394-3356, 2006). lauria-castelluccio mountains, located to the west of the mercure basin and separated by it from the pollino ridge, form a morphostructural high of the calabria-lucania border, southern italy, made of mesozoic shallow-water carbonates, whose evolution has been strongly controlled by quaternary tectonics. to the south of the ridge, a 15 km-long narrow depression, named valico di prestieri, is filled by continental pleistocene deposits organized in several sedimentary bodies. in this paper, the stratigraphic and morphostructural picture of the quaternary deposits and surrounding areas is widely discussed and, in the end, a reconstruction of miocene to pleistocene tectonic and morpho-evolutionary sequences is proposed. the original contractional structure – built on during late miocene to pliocene time-span – has been dismembered by pleistocene strike-slip and normal faulting along a n120°striking shear zone. several episodes of both tectonic crisis and quiescence have been recognized. during the quiescence periods, sculpture of erosional land surfaces and deposition of sedimentary bodies with gently dipping tops (alluvial fans and flood), both related to the different past base levels of the trough, took place. the use of such features as morphotectonic markers – whose ages have been deduced by morphostratigraphic correlations with the close mercure river and sinni river basins – allowed the estimation of the regional and local uplift rates and the calculation of the slip rates of the main high-angle faults. regional uplift rates are settled on a value of about 1 mm/yr, whereas the local rates are nearly coincident with the magnitude of the fault slip rates, reaching the highest values (about 0,5-0,6 mm/yr) at the passage between early and middle pleistocene, in correspondence of the beginning of the extensional tectonics with ne-sw oriented tensile axis. the amount of quaternary denudation due to fluvial erosion, calculated on the base of bedrock incision rates, is clearly less than tectonic burial (several km) suffered by the mesozoic formations of the lauria mts and surrounding areas. therefore, it is necessary to invoke alternative mechanisms of exhumation, such as tectonic erosion or denudation, that may adequately justify also the presence of lowangle normal or oblique faults, surveyed at mt. la spina and mt. zaccana and probably pliocene in age. parole chiave: evoluzione morfotettonica polifasica, tasso di sollevamento, faglia normale a basso angolo, denudamento tettonico, monti di lauria (appennino calabro-lucano). keywords: polyphase morphotectonic evolution, uplift rate, low-angle normal fault, tectonic denudation, lauria mts (calabria-lucania apennines, italy). il quaternario italian journal of quaternary sciences 19(1), 2006 129-142 1. introduzione i monti di lauria rappresentano una morfostruttura modellata nelle successioni calcareo-dolomitiche meso-cenozoiche di piattaforma costituenti le monoclinali del confine calabro-lucano (fig. 1), orlate a nord da un fronte di sovrascorrimento con vergenza verso n-ne e vistosamente smembrate dalla tettonica fragile plioquaternaria. la dorsale è infatti confinata a meridione dal corridoio morfotettonico del valico di prestieri, aggradato da sedimenti quaternari organizzati in più corpi deposizionali di ambiente continentale. in questa nota viene presentato uno studio geomorfologico della depressione e dei rilievi contigui, finalizzato alla rico130 d. gioia & m. schiattarella struzione della sequenza morfo-tettonoevolutiva che ha caratterizzato questo settore di catena dal neogene al quaternario. recenti studi enfatizzano il ruolo delle superfici di spianamento relitte e delle anomalie nei profili longitudinali dei corsi d’acqua come marker morfo-cronologici sui quali fondare le stime quantitative dei tassi di sollevamento regionali e locali della catena appenninica (schiattarella et al., 2003; 2006; boenzi et al., 2004). il buon grado di conservatività morfologica che caratterizza l’ossatura carbonatica dei monti di lauria e la presenza di diverse generazioni di depositi continentali nell’area del valico di prestieri, unitamente alla mancanza di studi a carattere morfostrutturale, sono i fattori che rendono di particolare interesse l’area di studio. il rilevamento geologico di dettaglio, con particolare riferimento ai depositi quaternari, ha interessato l’area compresa tra i rilievi di monte zaccana e monte la spina a nord e le dorsali di monte rossino e serra la nocara a sud. l’analisi geomorfologica è stata mirata in particolare alla dettagliata cartografazione delle superfici topografiche erosionali e/o deposizionali a basso angolo, oltre che al riconoscimento dei morfolineamenti di origine tettonica e di altri elementi del paesaggio fisico legati ai processi tettonici, ed è stata supportata anche dall’analisi morfometrica del reticolo idrografico, realizzata attraverso il calcolo di alcuni parametri geomorfici significativi dal punto di vista morfotettonico (rb, rbd, r) e la valutazione delle direzioni preferenziali di deflusso dei corsi d’acqua. l’analisi mesostrutturale degli elementi della deformazione fragile, con particolare riguardo allo stato di fratturazione dei terreni del bedrock carbonatico pre-quaternario, si è resa necessaria per la comparazione degli andamenti delle aste fluviali e delle famiglie di discontinuità e per la comprensione della cinematica di alcune faglie ad alto e basso angolo. il riconoscimento di diverse generazioni di superfici erosive sospese – alle quali è stato possibile attribuire un’età per correlazione morfostratigrafica con i vicini bacini del fiume mercure e del fiume sinni – dislocate dalle strutture tettoniche, ha permesso di valutare i tassi di sollevamento regionali e locali quaternari dell’area e di discriminare quantitativamente l’entità dei movimenti verticali associati alle diverse fasi morfoevolutive. la distribuzione plano-altimetrica di alcune generazioni di superfici di erosione relitte è stata, inoltre, confrontata con la quota sul livello del mare delle anomalie (punti di flesso o knickpoint) e di salti morfologici più pronunciati, non legati a morfoselezione, del profilo longitudinale di alcuni corsi d’acqua. come detto, pochi lavori a carattere geomorfologico e morfostrutturale hanno interessato in qualche modo i monti di lauria e dintorni: tra questi, si ricordano gli studi di bousquet & gueremy (1968), palmentola et al. (1980), la rocca & santangelo (1991) e schiattarella et al. (1994), nei quali l’area è tuttavia presa in considerazione nell’ambito di contesti più ampi. i caratteri geologici sono stati oggetto della memoria di bonardi (1966) e, nel contesto di una trattazione più generale sul confine calabro-lucano, dello scritto di lorenzo et al. (2001). 2. inquadramento geologico dell’appennino meridionale e dell’area del confine calabro-lucano l’appennino meridionale è una catena montuosa con generale vergenza nord-orientale, formata in prevalenza da falde derivanti dalla deformazione del paleomargine apulo-africano mesozoico-terziario, sovrascorse e impilate sulla microplacca adriatica in subduzione. dall’oligocene terminale, la tettonica compressiva ha coinvolto, in un primo stadio di accrezione, la crosta ofiolitica dell’oceano liguride con la relativa copertura (knott, 1987; mauro & schiattarella, 1988; bonardi et al., 1988) e successivamente i terreni di piattaforma e bacinali del margine passivo continentale (pescatore et al., 1999; cello & mazzoli, 1999). la migrazione verso est del fronte dei sovrascorrimenti, accompagnata dalla sedimentazione di potenti successioni clastiche sintettoniche, è stata seguita da una estensione di retroarco che ha interessato diacronicamente in tempi plio-pleistocenici prima la fascia tirrenica e poi quella assiale dell’orogene sud-appenninico. evidenze di attività compressiva pleistocenica sono invece documentate nella porzione esterna della catena (pieri et al., 1997). in molti settori della catena, come per la grande morfostruttura del pollino – monti di lauria, la primitiva struttura contrazionale neogenica risulta smembrata da faglie plio-quaternarie trascorrenti ed estensionali con diversi andamenti. particolare importanza rivestono i lineamenti tettonici con orientazione n120°, in quanto responsabili della genesi e dell’evoluzione di molti bacini quaternari, compresi quelli dell’area del confine calabro-lucano (schiattarella, 1998). il segmento sudappenninico è anche caratterizzato da faglie normali a basso angolo con cinematica estensionale ed obliqua, che realizzano contatti tettonici anomali del tipo “giovane su vecchio”, interpretati in maniera assai differente dai diversi autori che se ne sono occupati (d’argenio et al., 1986; ietto & d’argenio, 1990; schiattarella, 1996; ferranti et al., 1996; schiattarella et al., 2006). il confine calabro-lucano rappresenta, secondo molti autori (dewey et al., 1989; turco et al., 1990; cinque et al., 1993; catalano et al. , 1993; schiattarella, 1996; 1998; marra, 1998), la fascia di fig. 1 schema geologico del confine calabro-lucano. geological sketch map of the calabria-lucania border. svincolo cinematico tra l’appennino meridionale e l’arco calabro, che si realizza attraverso lo sviluppo di una zona di taglio sinistra orientata all’incirca n120°. nell’area affiorano estesamente unità interne ofiolitifere, di norma in sovrapposizione tettonica su unità carbonatiche derivanti dalla deformazione della piattaforma appenninica. lungo il margine settentrionale della catena del pollino e dei monti di lauria si osserva tuttavia il sovrascorrimento fuori sequenza delle successioni carbonatiche mesozoiche sugli antistanti termini bacinali (schiattarella, 1996; 1998). le formazioni che compongono le successioni di mare basso ascrivibili alle unità che derivano dalla deformazione della piattaforma campano-lucana sono rappresentate da un complesso calcareo-dolomitico di età compresa tra il trias superiore ed il cretacico superiore, su cui poggiano in concordanza l’alternanza paleogenica calcareo-marnosa della formazione di trentinara o le calcareniti a glauconite della formazione di cerchiara del miocene inferiore. la successione è chiusa dalla formazione del bifurto, data da un’alternanza di età infra-mesomiocenica di argilliti, calcari marnosi, calcareniti, brecciole a macroforaminiferi rimaneggiati e quarzareniti, che rappresenta la fase di annegamento della piattaforma carbonatica. l’assetto tettonico della catena del pollino e dei monti di lauria-castelluccio deriva dallo smembramento della struttura contrazionale mio-pliocenica ad opera delle faglie prevalentemente quaternarie. un complesso pattern strutturale (turco et al., 1990) viene così prodotto nell’ambito della deformazione trascorrente, attiva dal pliocene superiore, le cui faglie sono successivamente riattivate in regime estensionale (russo & schiattarella, 1992; schiattarella, 1998). studi morfostrutturali sui bacini di castrovil lari (russo & schiattarella, 1992), del mercure (schiattarella et al., 1994) e di morano calabro (perri & schiattarella, 1997) hanno consentito di porre un vincolo temporale all’attività trascorrente, che risulta ancora in essere durante il siciliano, mentre la tettonica estensionale, tuttora attiva, si sviluppa a partire dal passaggio tra il pleistocene inferiore e medio. 3. stratigrafia dei monti di lauria e depositi quaternari del valico di prestieri i monti di lauria sono costituiti da una serie di dorsali allungate in direzione n120°, in prevalenza costituite dai termini cretacici della successione carbonatica della piattaforma campano-lucana. i rilievi di serra rotonda e serra destra del tornesiello, ubicati lungo il margine nord-occidentale dell’area, e quelli di serra sardina e serra la nocara, che costituiscono rispettivamente il bordo occidentale e sud-occidentale del basso strutturale del valico di prestieri, sono caratterizzati da calcari con rudiste. dolomie altotriassiche formano invece l’ossatura dei rilievi di monte la spina e monte zaccana, alla cui sommità si rinvengono, in contatto tettonico per faglia normale a basso angolo, lembi calcarei giurassici e cretacici. alternanze terrigene mioceniche, in giacitura spesso caotica, sono conservate in aree di basso strutturale, come ad esempio in località la starsia, e formano parte del paesaggio collinare che 131caratteri morfotettonici dell’area ... si dipana lungo il pedemonte meridionale di serra rotonda. la formazione di trentinara costituisce, invece, parte della dorsale di serra pastorella, poco ad est dell’abitato di lauria. nell’area investigata, brecce di versante a matrice arrossata giacciono su ripiani erosionali sospesi rispetto al top deposizionale del riempimento fluvio-lacustre del mercure (ad esempio immediatamente ad est di monte zaccana). simili brecce, molto tettonizzate, si rinvengono a la starsia, in posizione di basso relativo e totalmente sganciate dai rilievi alimentatori. il deposito è caratterizzato da clasti carbonatici eterometrici da centimetrici a decimetrici, cementati, con matrice sabbiosa rossastra a luoghi molto abbondante. schiattarella et al. (1994) correlano questi depositi detritici, prodotti dal disfacimento dei primi versanti di faglia dell’area, alle facies prossimali delle “sabbie e conglomerati di serra corneta” (vezzani, 1967), attribuibili al pleistocene inferiore-medio. i sedimenti continentali quaternari del valico di prestieri affiorano, in prevalenza, alla base dei versanti meridionali di monte la spina e monte zaccana (fig. 2), a formare una serie di apparati conoidali che verso valle si interdigitano ai depositi lacustri mediopleistocenici del bacino del mercure. si tratta di ghiaie clasto-sostenute, solo localmente cementate, con elementi subarrotondati e sottili livelli sabbiosi, soprattutto nelle porzioni distali delle conoidi, che definiscono grossolanamente una clinostratificazione. il deposito è stato attribuito alla parte bassa del pleistocene medio da schiattarella et al. (1994). nell’area si rinviene un’altra serie di conoidi alluvionali, incastrate morfologicamente nelle precedenti, costituite da ghiaie massive con clasti carbonatici, in prevalenza dolomitici, a spigoli vivi di dimensioni da centimetriche a decimetriche; localmente si osservano grossi blocchi disposti caoticamente, che tendono a sparire nelle zone distali dove alle ghiaie si alternano livelli sabbiosi. a luoghi, le ghiaie sono caratterizzate da una matrice sabbiosa di colore rossastro. si osservano regolarmente anche intercalazioni di paleosuoli costituiti da argille limose brune con scheletro di varie dimensioni, che testimoniano ripetuti periodi di stasi nella sedimentazione alluvionale. lo spessore di questi depositi, rilevato da dati inediti di perforazione per ricerche idriche, raggiunge i 30 metri nelle zone distali. sulla base di considerazioni morfologiche, è possibile attribuire queste alluvioni alla parte alta del pleistocene medio. depositi colluviali e coni detritici del pleistocene superiore – olocene poggiano quasi ovunque sui depositi precedentemente descritti. 4. assetto tettonico e analisi strutturale per quanto concerne il fronte montuoso settentrionale dei monti di lauria-castelluccio, bonardi (1966) segnala la presenza di un piano di faglia che realizza il sovrascorrimento delle dolomie sui depositi terrigeni miocenici lungo il versante orientale della dorsale tempa arena bianca – monte lanzino, a nord di monte la spina. più estesamente, a nord della dorsale monte zaccana monte la spina serra rotonda, 132 schiattarella (1996) rileva il sovrascorrimento fuori sequenza dei terreni carbonatici sulle successioni pelagiche liguridi e lagonegresi. fenomeni di deformazione contrazionale o traspressiva di probabile età pliocenica sono stati riconosciuti anche lungo il fronte settentrionale della catena del pollino (schiattarella, 1996) e nei monti di maratea (lorenzo et al., 2001). alla sommità e lungo i versanti meridionali dei rilievi di monte la spina e monte zaccana si osservano le faglie trastensive a basso angolo che, come detto, realizzano la sovrapposizione di lembi calcarei giurassici o cretacici su dolomie altotriassiche. ietto & d’argenio (1990) interpretano i contatti “giovane su vecchio” come espressione di una tettonica estensionale sovrapposta alla tettonica contrazionale neogenica. ferranti et al. (1996) sostengono che l’estensione, avvenuta parallelamente all’asse della catena, si sia formata in risposta all’aumento della lunghezza e dell’inarcamento della catena, mentre perri & schiattarella (1997) relazionano le faglie a basso angolo e scivolamento obliquo, sulla base della compatibilità cinematica, al fagliamento trascorrente suprapliocenico-infrapleistocenico all’interno di zone di taglio orientate n120°. la differenza tra l’entità dei tassi di sollevamento quaternari (legati alla tettonica estensionale accoppiata con la risalita isostatica/termica dell’orogene e, in misura minore, allo stesso fagliamento trascorrente, attivo durante le prime fasi neotettoniche) ed i valori del carico tettonico sopportato dalle successioni mesozoiche, suggerisce invece di collegare geneticamente queste strutture a processi di denudamento tettonico attivi fin dalle fasi contrazionali di costruzione della catena (schiattarella et al., 2003; 2006). le superfici tettoniche a basso angolo con componente normale del movimento appaiono in ogni caso più vecchie delle faglie neotettoniche. una faglia normale ad alto angolo orientata all’incirca e-o, ad esempio, disloca un simile contatto lungo il versante meridionale di monte la spina (fig. 3). la dissezione ad fig. 2 carta geologica dell’area del valico di prestieri. nel riquadro in basso a destra, schema tettonico dell’area del confine calabrolucano (da schiattarella, 1998). geological sketch map of the valico di prestieri area. in the box below on the right, tectonic sketch map of the calabria-lucania boundary (after schiattarella, 1998). fig. 3 sezione geologica del versante meridionale di monte la spina. geological cross-section of the southern slope of mt. la spina. d. gioia & m. schiattarella 133 opera delle faglie quaternarie, la dissecazione del rilievo causata dai corsi d’acqua, susseguenti e non, e i processi di erosione selettiva sono infine responsabili dell’attuale configurazione “a lembi” delle sovrapposizioni tettoniche anomale. il versante sud-occidentale dei rilievi di serra sardina e serra rotonda è delimitato da una faglia subverticale normale orientata n160°, che accosta i calcari cretacici ai terreni miocenici. la dorsale monte rossino – serra la nocara, allungata in direzione n120°, appare invece dislocata trasversalmente a gradinata da una serie di faglie a direzione antiappenninica e componente prevalentemente normale, con aumento dei rigetti da se a no, come mostrato dalla distribuzione e dalla dislocazione delle superfici erosionali (vedi paragrafo successivo). immediatamente a sud della dorsale compresa tra lauria e castelluccio inferiore, si dipana per circa 15 km il basso strutturale del valico di prestieri, perimetrato da faglie orientate n120°, n-s e n30-40° e colmato da sedimenti continentali quaternari. i dati relativi alle mesostrutture fragili, relativi a tre stazioni di misura ubicate in figura 4, sono stati accorpati per famiglie azimutali (fig. 5). ciò ha permesso di identificare la fase tettonica più recente, a carattere distensivo ed asse tensile in direzione ne-so, responsabile della produzione delle faglie normali con orientazione media n150-160° che tagliano tutte le altre strutture della deformazione fragile. i piani n120-130° presentano spesso cinematica trastensiva destra, proprio in funzione della riattivazione in regime estensionale delle faglie trascorrenti. un simile motivo polifasico caratterizza anche le faglie meridiane e antiappenniniche con valori dell’angolo di pitch alquanto variabile, a testimonianza di ripetuti fenomeni di riattivazione di piani di discontinuità preesistenti. si registra, infine, la diffusa presenza di sistemi di joint estensionali all’incirca meridiani (fig. 5d), che hanno avuto una certa influenza nel condizionamento del reticolo idrografico. 5. analisi morfostrutturale le dorsali carbonatiche dei monti di lauria sono bordate da faglie ad alto angolo trascorrenti ed estensionali che hanno generato una serie di depressioni occupate dai depositi continentali quaternari e, in misura minore, dai sedimenti terrigeni miocenici. la depressione maggiore, aggradata da una serie di conoidi alluvionali quaternarie, si colloca tra i rilievi dolomitici di monte la spina e monte zaccana e quelli calcarei di monte rossino e serra la nocara. il basso strutturale de la starsia, meno esteso del precedente, caratterizza, invece, la parte nord-occidentale dell’area di studio ed è impostato nelle successioni terrigene mioceniche. in quest’area si ritrovano affioramenti di brecce in lembi più o meno estesi ascrivibili al pleistocene inferioremedio. diverse evidenze morfologiche (discontinuità altimetriche e plano-altimetriche dei versanti, versanti a sviluppo rettilineo, allineamenti di vette e doline) e anomalie del reticolo idrografico (corsi d’acqua a sviluppo rettilineo, gomiti e doppi gomiti fluviali, forre) mettono in luce, in accordo con l’analisi strutturale, sistemi di faglie distribuiti sistematicamente secondo le direzioni n-s, fig. 4 reticolo idrografico gerarchizzato con relativi valori degli indici morfometrici (nu = numero di corsi di ordine u; rb = rapporto di biforcazione; ndu = numero di corsi di ordine u che fluiscono in corsi di ordine u+1; rbd = rapporto di biforcazione diretto; r = indice di biforcazione) e ubicazione delle stazioni di misura strutturale. in tratteggio, i corsi d’acqua analizzati come indicatori morfotettonici del sollevamento quaternario. drainage network pattern with the relative values of morphometric parameters (nu = number of streams of the u order ; rb = bifurcation ratio; ndu = number of streams of u order flowing in u+1 order; rbd = direct bifurcation ratio; r = bifurcation index) and location map of the structural measurement stations. in dotted line, the channels analysed like morphotectonic indicators of the quaternary uplift. fig. 5 stereogrammi delle faglie rilevate nei terreni carbonatici, accorpate per famiglia azimutale. a) no-se; b) n-s; c) n30-60°; d) diagramma azimutale dei sistemi di frattura rilevati, alla mesoscala, nei carbonati meso-cenozoici. stereoplots of faults collected in carbonate rocks, separated on the basis of the azimuthal classes. a) nw-se; b) n-s; c) n30°-60°; d) rose diagram of the tectonic joint sets affected meso-cenozoic carbonates of the study area. caratteri morfotettonici dell’area ... 134 n120°, n30-50° e n160° (fig. 6). la realizzazione di alcuni profili morfostratigrafici, corredati da dati geologici e strutturali, ha dimostrato che queste strutture tettoniche sono responsabili della dislocazione delle diverse generazioni di superfici di spianamento relitte (figg. 7, 8 e 9). reticolo idrografico i l reticolo idrografico dei monti di lauriacastelluccio (fig. 4) mostra, in generale, una bassa densità di drenaggio, insistendo principalmente sui carbonati che formano l’ossatura della monoclinale e sui depositi alluvionali quaternari caratterizzati da una buona permeabilità e da bassi gradienti di pendio. il deflusso delle acque mostra una migliore organizzazione in corrispondenza degli affioramenti delle dolomie bianche altotriassiche, soprattutto nella zona di testata e, in misura maggiore, laddove insiste sulle litologie delle successioni terrigene. l’organizzazione e il grado di maturità del reticolo può essere desunta dagli alti valori degli indici morfometrici (avena et al., 1967) dei quattro sottobacini del 4° ordine in cui è divisa l’area. in particolare, gli alti valori dell’indice di biforcazione delle aste di alto ordine gerarchico (valori di 1,4 e 2 per il 2°/3° ordine e il 3°/4° ordine, rispettivamente) sono probabilmente dovuti alla diffusa presenza di segmenti anomali nei corsi d’acqua maggiori ed indicano una struttura del reticolo alquanto disorganizzata, propria delle aree in cui l’evoluzione del reticolo è controllata dalla struttura (firpo & spagnolo, 2000). l’analisi su base statistica delle direzioni di deflusso delle acque (fig. 6) ha messo in luce alcuni andamenti preferenziali nella direzione dei corsi d’acqua. il diagramma “a rosetta” relativo alle aste di basso ordine gerarchico (1° e 2° ordine, fig. 6d) mostra un massimo assoluto attorno alla classe meridiana, oltre ad un picco meno sviluppato in corrispondenza della classe n90-100°. per quanto concerne le sole aste del 1° ordine, anche la classe n30-40° appare statisticamente significativa (fig. 6a). il diagramma azimutale delle fratture ad alto angolo (costruito sulla base delle 331 misure effettuate nelle tre stazioni riportate in fig. 4) mostra l’esistenza di un chiaro massimo assoluto in corrispondenza dell’andamento meridiano, oltre ad un picco meno sviluppato attorno alla classe n90-100° (fig. 5d). la geometria del sistema di fratture è pertanto rappresentata nell’intera area da due famiglie ortogonali, come rilevato alla mesoscala, ad esempio, a serra la nocara. la buona corrispondenza tra le direzioni di deflusso preferenziale delle aste di basso ordine gerarchico e quelle dei sistemi di frattura dimostra che la nascita e lo sviluppo dei corsi d’acqua minori sono fortemente controllati dallo stato di fratturazione dell’ammasso roccioso carbonatico. il massimo relativo n3040° relativo alle aste del 1° ordine sembra invece più semplicemente relazionato alle direzioni di massima pendenza (il trend è ortogonale all’allungamento morfostrutturale della depressione). le aste del 3° ordine si distribuiscono intorno a più direzioni. nonostante una certa dispersione dei dati, si possono riconoscere i trend n-s, n40-50°, n90-100° e n140-150°. è da notare che alcune direzioni preferenziali di deflusso delle aste del 3° ordine corrispondono, almeno in parte, agli andamenti dei morfolineamenti più fig. 6 a) diagramma azimutale delle aste del 1° ordine; b) diagramma azimutale delle aste del 2° ordine; c) diagramma azimutale delle aste del 3° ordine; d) diagramma azimutale delle aste del 1° e del 2° ordine; e) diagramma azimutale dei morfolineamenti di origine tettonica (base dei versanti di faglia, corsi d’acqua rettilinei, gomiti fluviali, ecc.) dell’area; f) diagramma azimutale costruito sulla base della lunghezza dei morfolineamenti di origine tettonica (modulo unitario di 500 m). a) rose diagrams of the i order streams; b) rose diagrams of the ii order streams; c) rose diagrams of the iii order streams; d) rose diagrams of the i and ii order streams; e) rose diagrams of the tectonic lineaments of the area; f) rose diagrams constructed on the basis of the length of tectonic lineaments (unit module = 500 m). lunghi dell’area e, in particolare, ai lineamenti con orientazione n-s, e-o e n130-140° (cfr. figg. 4 e 6f). i profili longitudinali di alcuni corsi d’acqua (fosso rubbiolo e torrente salice, fig. 10) mostrano alcuni flessi e salti non legati a morfoselezione, dovuti alla risposta dei corsi d’acqua al sollevamento recente (boenzi et al., 2004; molin et al., 2004), che appaiono in accordo con la distribuzione altimetrica delle superfici erosionali (figg. 8 e 9; cfr. sottoparagrafo successivo). i tratti di corsi d’acqua a sviluppo rettilineo, i segmenti rettilinei di forre (torrente caffaro, fosso della zaccana e vallone buona zita), i gomiti e i doppi gomiti fluviali, unitamente ai versanti a sviluppo rettilineo, alle faccette triangolari ed alle discontinuità altimetriche e plano-altimetriche dei crinali, hanno permesso di individuare famiglie di faglie, la cui espressione morfologica è stata anche riconosciuta dall’analisi di aerofoto e verificata sul terreno, distribuite attorno alle classi azimutali d. gioia & m. schiattarella n-s, n50-60°, n90-100°, n120°-n150°. il trend meridiano è chiaramente prevalente nell’area, pur risultando significativamente presenti anche gli andamenti compresi nei quadranti no e se, come meglio mostrato dal diagramma costruito in funzione della lunghezza dei morfolineamenti (fig. 6f). in particolare, le faglie con orientazione n120°, che peraltro rappresentano elementi strutturali a valenza regionale (schiattarella, 1998), hanno esercitato una certa influenza solo sui corsi d’acqua di alto ordine gerarchico, come ad esempio si può rilevare alla base del versante nord-orientale di monte fossino, dove il fosso rubbiolo si dispone secondo tale andamento con un percorso pressoché rettilineo (fig. 4). 135 fig. 7 schema morfostrutturale dell’area dei monti di lauria e del valico di prestieri. morphostructural map of the lauria mts – prestieri trough area. caratteri morfotettonici dell’area ... superfici erosionali e deposizionali molti dei versanti di faglia dell’area investigata sono caratterizzati da profili convessi o da profili complessi realizzati da superfici erosionali a debole pendenza sospese rispetto all’attuale livello di base che raccordano tratti di versante ad inclinazione costante ma diversa per i differenti segmenti. entrambi i casi testimoniano l’evoluzione polifasica del rilievo, prodotta dall’alternanza di momenti di sollevamento e di fasi erosive. durante antichi stazionamenti dei livelli di base locali dell’erosione, la morfogenesi ha prodotto superfici di spianamento o cenge e ripiani erosionali, scolpiti in 136 fig. 8 distribuzione plano-altimetrica dei lembi relitti di superfici erosionali e deposizionali e principali morfolineamenti di origine tettonica. spatial arrangement of the relict erosional and depositional surfaces and main tectonic lineaments of the area. d. gioia & m. schiattarella 137 fig. 9 profili morfostratigrafici, integrati da dati geologico-strutturali, che intercettano i diversi ordini di superfici erosionali e deposizionali relitte morphostratigraphic sections showing the different orders of relict erosional and depositional surfaces of the area. discordanza prevalentemente nelle unità carbonatiche mesozoiche, ma anche nelle successioni terrigene mioceniche e nei depositi continentali plio-quaternari. i singoli lembi hanno dimensioni variabili da poche centinaia di metri ad alcuni chilometri quadrati, pendenze inferiori ai 7-8° e bassa energia di rilievo. i lembi alle quote più caratteri morfotettonici dell’area ... elevate si configurano come relitti di più ampie superfici erosionali mentre quelli situati a quote più basse presentano caratteristiche che sembrano indicare un modellamento più simile alle condizioni prodotte dal reticolo idrografico attuale. nell’area dei monti di lauria-castelluccio sono stati riconosciuti quattro ordini di superfici di erosione sospese rispetto al fondovalle attuale, indicative di altrettanti paleolivelli di base locali dell’erosione, distribuite tra 1600 m e 700 m di quota s.l.m.; a ciascun ordine di superfici spianate è stata attribuita un’età di disattivazione (riferita al momento in cui viene dislocata una superficie di erosione, si deprime il livello di base e si innesca un approfondimento verticale che si sviluppa con maggiore energia rispetto all’erosione laterale) sulla base dei dati di letteratura, con particolare riferimento alle aree del bacino del mercure e della catena del pollino (schiattarella et al., 1994; 2006). l’elemento geomorfologico più antico (s1) è rappresentato dai resti di un antico paesaggio erosionale sub-pianeggiante di estensione regionale (“paleosuperficie” in capaldi et al., 1988) posto in posizione sommitale sui monti di lauria-castelluccio, a cui è stata attribuita un’età di disattivazione compresa tra il pliocene superiore ed i l pleistocene inferiore (schiattarella et al., 2003; boenzi et al., 2004). i lembi della superficie sommitale, scolpiti in discordanza sui terreni carbonatici e distribuiti a quote superiori ai 1300 metri, sono fortemente rimodellati e presentano forme tipiche di morfogenesi in ambiente fluvio-carsico, come sulla sommità del monte rossino, dove la s1 si presenta debolmente ondulata e con tracce di erosione subaerea quali incisioni e doline. i lembi che formano la cima di serra rotonda e di monte la spina sono invece ridotti in estensione dal modellamento retrogrado dei versanti e la preesistente spianata è testimoniata solo dall’andamento sub-orizzontale dei crinali. l’originaria genesi della paleosuperficie auctt. è stata attribuita a processi di modellamento in ambiente marino-transizionale (boenzi et al., 2004), le cui tracce risultano obliterate dal successivo rimodellamento in contesti morfoclimatici continentali. la sovrapposizione di diversi episodi morfogenetici permette di considerare la superficie s1 come una superficie di spianamento poligenica; inoltre essa è da considerare anche policiclica, a causa della riattivazione tettonica del ciclo erosivo. i lembi della superficie sommitale sono delimitati da un versante di faglia che si raccorda ad un ampio paesaggio di erosione (superficie di erosione s2), riconducibile ad un modellamento composito di tipo fluviocarsico, che insiste sia sul substrato carbonatico che, a luoghi, sulle “brecce antiche” di bousquet et al. (1969). i lembi della s2 hanno dimensioni abbastanza ridotte e si distribuiscono attorno a quote comprese tra 1300 ed i 1000 metri s.l.m.; il carattere poligenico della superficie s2, alla quale è possibile attribuire un’età di disattivazione compresa nell’intervallo temporale 1.4-1.1 ma (in cui ricade la crisi tettonica “emiliana”, documentata nell’area da russo & schiattarella, 1992), è evidenziato dalla sovrapposizione di forme riconducibili a processi di erosione lineare su elementi morfologici legati ad un modellamento di tipo carsico. la superficie s3 presenta caratteristiche diverse rispetto ai paesaggi più antichi in quanto si configura come un glacis d’erosione o di accumulo che si raccorda alle superfici s1 e s2 tramite versanti di faglia regolarizzati, profondamente inciso dai corsi d’acqua e sospeso rispetto al fondovalle attuale. i lembi della superficie s3 sono i più ampi e diffusi dell’area di studio, distribuiti tra gli 800 e i 1000 metri di quota e frequentemente modellati sui calcari cretacici. l’età di disattivazione attribuibile alla superficie s3 è di circa 0.8-0.7 ma, poiché essa appare correlabile con il top deposizionale delle brecce di misciarolara, affioranti alla terminazione nord-orientale della dorsale dei monti di lauria e attribuite da schiattarella et al. (1994) al pleistocene inferiore-medio. la superficie s4 coincide con il top deposizionale delle conoidi alluvionali recenti dell’area del valico di prestieri ed è sospesa a poche decine di metri rispetto al fondovalle attuale. l’incisione di questo elemento ad opera del torrente salice è iniziata presumibilmente a 0.13-0.11 ma circa, in seguito al vistoso approfondimento del reticolo idrografico del contiguo bacino del mercure, aggradato da sedimenti lacustri post-mindeliani, a sua volta innescato dal sollevamento “tirreniano”. i profili morfometrici qui presentati (fig. 9) mostrano chiaramente il carattere erosionale delle superfici poste a quote più elevate, scolpite in discordanza rispetto alla giacitura del substrato carbonatico. l’attività delle faglie ha dislocato e sospeso le superfici di spianamento, attivando nuovi cicli morfogenetici, probabilmente caratterizzati anche da condizioni morfoclimatiche diverse, e ne ha determinato il carattere poli138 fig. 10 anomalie, non legate a morfoselezione, nei profili longitudinali del torrente salice e del fosso rubbiolo, correlabili ai livelli di base locale dell’erosione riconosciuti attraverso le superfici relitte. knickpoints of the longitudinal profiles of salice and rubbiolo streams, correlated with the same orders of erosional and depositional surfaces. d. gioia & m. schiattarella genico e policiclico. altre faglie sono invece rasate, e dunque fossilizzate, dal modellamento della superficie (si veda ad esempio il profilo a-a’). i rigetti verticali maggiori si registrano lungo i versanti che raccordano le superfici s2 con quelle s3. localmente si può osservare come alcuni lembi originariamente orizzontali siano basculati e ruotati contro monte dall’attività tettonica. al fine di individuare i paleolivelli di base locale dell’erosione, sono stati anche eseguiti alcuni profili longitudinali a scala di dettaglio (1:5000) lungo corsi d’acqua minori dell’area in esame (fig. 10). la risposta di un corso d’acqua al sollevamento recente porta all’alterazione del suo profilo attraverso la formazione di un flesso (knickpoint), in corrispondenza dello stazionamento degli antichi livelli di base locali, che si conserva nel medio termine in litologie lapidee. la presenza di piccoli terrazzi strath e cenge erosionali in roccia in coincidenza dei punti di flesso corrobora tale ipotesi. gli intervalli di quota delle anomalie ed i salti non legati a morfoselezione dei profili longitudinali dei corsi sono stati quindi confrontati con quelli delle superfici di erosione. la correlazione altitudinale, operata per settori omogenei, mostra una buona corrispondenza tra gli indicatori di paleolivelli di base più recenti. la differenza di quota tra le anomalie nel profilo longitudinale del torrente salice e quelle del fosso rubbiolo, che mostra il paleolivello di base locale corrispondente alla superficie s3 a quote maggiori, può essere imputata al fatto che quest’ultimo intercetta alcune faglie che non incrociano, invece, il corso del torrente salice. 6. tassi di sollevamento l’età e la distribuzione altimetrica dei diversi ordini di superfici erosionali dell’area di studio hanno permesso di calcolare i tassi di sollevamento e l’entità dei rigetti verticali prodotti dalle faglie. il grafico quota/età (fig. 11) evidenzia che nel quaternario l’energia del rilievo è stata acquisita in modo pressoché costante. si osserva solo un leggero aumento della velocità dell’acquisizione del rilievo (maggiore pendenza della curva) dalla metà del pleistocene inferiore all’inizio del pleistocene medio. i tassi di sollevamento regionale vanno ad assestarsi su valori medi di circa 1 mm/a, con una crescita costante dal pliocene terminale al pleistocene medio. i tassi di sollevamento locale, che coincidono in linea di massima con il tasso di scivolamento lungo le faglie dell’area, mostrano valori medi intorno a 0,5 mm/a fino al pleistocene medio per diminuire sensibilmente in seguito. il decremento dei tassi di sollevamento durante il pleistocene superiore è in accordo con i dati provenienti da altre zone dell’appennino meridionale e può essere suffragato, nell’area del confine calabro-lucano, dai dati paleosismologici e dalla scarsità di evidenze di deformazione nei depositi più recenti (ferreli et al., 1996; perri & schiattarella, 1997). la dislocazione tettonica delle superfici spianate è stata utilizzata per calcolare il tasso di scivolamento lungo la faglia che borda a sud il rilievo di monte zaccana e che rappresenta forse il principale elemento strutturale dell’area. il rigetto verticale totale cumulato nel corso del quaternario è di circa 700 metri, con uno slip rate di 0,5 mm/a. 7. conclusioni sulla base dei dati morfostratigrafici e morfostrutturali acquisiti in questo studio, la storia tettono-evolutiva dell’area dei monti di lauria e del valico di prestieri può essere riassunta nel modo di seguito illustrato e rappresentato schematicamente in figura 12. le strutture legate alla tettonica contrazionale oligo-miocenica (pescatore et al., 1999) che non avevano prodotto un rilievo apprezzabile, almeno nell’area investigata vengono tagliate e dislocate, probabilmente durante il pliocene inferiore, da piani di taglio a basso angolo con cinematica normale o obliqua. l’ipotesi più probabile, avallata anche dal confronto tra i dati relativi ai tassi di sollevamento quaternari e dei carichi tettonici stimati per l’area dei massicci carbonatici silentini, per le unità interne ofiolitifere e per il nucleo profondo della catena appenninica (schiattarella et al., 2003; 2006; aldega et al., 2005; di leo et al., 2005), è che si tratti di strutture generate da processi di denuda139 fig. 11 rappresentazione grafica dei tassi di sollevamento quaternari regionale e locale. il tasso di scivolamento della faglia che borda, con andamento all’incirca n120°, il versante meridionale di monte zaccana è stato calcolato sulla base dell’entità dei rigetti verticali cumulati dalle superfici erosive sospese. diagrams showing quaternary regional and local uplift rates. slip rates of the fault bordering the southern slope of mt. zaccana has been calculated on the basis of the erosional surfaces displacement. caratteri morfotettonici dell’area ... mento tettonico, attivati e guidati dalla topografia della catena acquisita durante la deformazione contrazionale tardoe post-miocenica, come recentemente sostenuto da schiattarella et al. (2003; 2006). il principale vincolo cronologico per determinare l’intervallo di attività del denudamento tettonico è rappresentato dall’età di emersione della catena nel settore assiale (non prima del tortoniano inferiore, età più recente dei depositi terrigeni miocenici dell’area, cfr. aldega et al., 2005). inoltre, i rapporti intercorrenti con la paleosuperficie auctt. permettono in ogni caso di considerare queste strutture nei carbonati mesozoici più antiche del pliocene superiore e di collocarle perciò nell’ambito della deformazione infrapliocenica. le faglie a basso angolo con componente normale, responsabili dei contatti tettonici “giovane su vecchio” (ietto & d’argenio, 1990), si configurano pertanto come dei relitti morfostrutturali antichi, in posizione apicale rispetto ai versanti di faglia pleistocenici, dislocati dalla tettonica fragile plio-quaternaria e isolati dall’erosione lineare. successivamente ai fenomeni di denudamento tettonico (e quindi probabilmente a partire dal pliocene medio) ha luogo il sovrascorrimento fuori sequenza dei terreni carbonatici sulle unità interne, che lungo il bordo settentrionale della catena del pollino è interpretabile per quanto concerne la sua evoluzione infrapleistocenica e sulla base di considerazioni cinematico-giaciturali (schiattarella, 1996) come legato alla rotazione antioraria di circa 30° lungo l’asse verticale di blocchi rigidi individuati dall’intersezione di faglie trascorrenti sinistre con orientazione n120° e faglie trascorrenti destre ad andamento meridiano. i modesti rigetti verticali prodotti da questa tettonica a scala regionale promuovono il modellamento di una morfologia matura (paleosuperficie auctt.) che viene dislocata tra il pliocene superiore ed il pleistocene inferiore, in risposta al perdurare del regime di trascorrenza sinistra lungo i lineamenti n120° (russo & schiattarella, 1992; perri & schiattarella, 1997). la direzione di estensione compatibile con questo campo deformativo genera faglie dirette o trastensive ad andamento n30-60°, che producono deboli rigetti verticali ed individuano bassi morfostrutturali all’interno dei quali si accumulano i depositi clastici (“brecce antiche”) derivanti dalla degradazione dei primi versanti di faglia. nel passaggio tra il pleistocene inferiore e medio il nuovo regime estensionale ad asse ne-so genera faglie normali orientate circa n150-160° e riattiva le faglie trascorrenti n120° con movimenti obliqui o normali, mentre quelle antiappenniniche e meridiane assolvono passivamente al compito di trasferire la deformazione in settori adiacenti (schiattarella et al., 1994; schiattarella, 1998). in questa fase i rilievi carbonatici dei monti di lauria-castelluccio acquisiscono i massimi rigetti verticali e il basso del valico di prestieri, che guadagna spazio di accomodamento per i sedimenti, viene riempito dai depositi di conoide alluvionale. tale stadio deformativo perdura durante il pleistocene medio in quanto sblocca la superficie s3 dell’area di studio e tettonizza i depositi lacustri del bacino del mercure (schiattarella et al., 1994). l’attività delle faglie sembra invece diminuire nel pleistocene superiore: i depositi di conoide altopleistocenici non presentano evidenze di deformazione, in accordo con i dati paleosismologici (ferreli et al., 1996), e si assiste solo alla reincisione dei depositi alluvionali altopleistocenici e alla deposizione dei depositi detritici recenti. il riconoscimento di diversi ordini di superfici di spianamento poligeniche e polifasiche ha permesso di determinare l’entità dei movimenti verticali quaternari. l’energia del rilievo è stata acquisita nell’area tramite la congiunzione del sollevamento regionale e dell’attività delle faglie ad alto angolo, come del resto accaduto per l’intero appennino meridionale, vistosamente smembrato dagli eventi neotettonici. il tasso di sollevamento regionale si attesta attorno a 1 mm/a, mentre la velocità di scivolamento delle superfici delle faglie principali è mediamente di 0,5 mm/a. le evidenze morfostrutturali permettono di affermare che gli slip rate delle faglie dell’area si distribuiscono intorno a valori più elevati nell’intervallo temporale relativo al passaggio pleistocene inferiore-medio. il sollevamento tettonico ed i periodi di stasi sono stati registrati anche dai corsi d’acqua dell’area, attraverso la formazione di knickpoint in corrispondenza delle quote dei paleolivelli di base locale dell’erosione più recenti. le direzioni preferenziali di deflusso 140 fig. 12 sequenza morfo-tettonoevolutiva dell’area di studio dal miocene medio al quaternario. legenda: i segni + e indicano rispettivamente i blocchi rialzati e ribassati, le aree con puntinato i depositi quaternari, le linee diritte con frecce o tratti rappresentano rispettivamente le faglie trascorrenti e dirette, le linee tratteggiate le faglie di trasferimento, le linee curve con triangoli i sovrascorrimenti, le linee curve con frecce e trattini le faglie normali a basso angolo. morphotectonic evolutionary sequence of the study area from middle miocene to quaternary. legend: signs + and show uplifted and downthrown blocks, dotted parts represent the quaternary deposits, straight lines with arrows or dashes are respectively strike-slip and normal faults, broken lines are transfer faults, curved lines with triangles represent thrusts, curved lines with arrows and dashes represent low-angle normal faults. d. gioia & m. schiattarella delle acque coincidono inoltre con le direzioni delle strutture tettoniche recenti. in particolare, lo sviluppo del reticolo risente fortemente dell’influenza della tettonica mediopleistocenica: i corsi d’acqua di basso ordine gerarchico sono impostati sulle vie di minore resistenza che nelle litologie carbonatiche sono rappresentate tipicamente da fratture ad alto angolo che pervadono l’ammasso roccioso, mentre le aste di ordine maggiore si distribuiscono lungo i principali lineamenti strutturali, secondo percorsi pressoché rettilinei e valli ripide e strette. la fase tettonica mediopleistocenica determina anche un’ondata di erosione regressiva che produce un generale approfondimento dei corsi d’acqua, il terrazzamento dei depositi conoidali del valico di prestieri e l’incisione del substrato. a questo generale approfondimento del reticolo sono collegati anche i fenomeni di esumazione della base di alcuni versanti di faglia, la genesi di numerose forre e probabilmente qualche fenomeno di cattura fluviale (p.es. alto corso del t.te caffaro). è interessante notare, in conclusione, come l’attuale assetto geomorfologico di un’area relativamente poco estesa sia il risultato della stessa sommatoria di avvenimenti tettonici, deposizionali ed erosivi che hanno interessato l’intera zona assiale dell’appennino meridionale e che, pertanto, anche da simili aree si possono ricavare informazioni atte a verificare la congruenza di modelli evolutivi relativi a contesti più ampi. ringraziamenti gli autori desiderano ringraziare due referee anonimi per gli utili suggerimenti. lavoro finanziato con il contributo cofin prin 2005, unità operativa dell’università della basilicata (resp. m. schiattarella). lavori citati aldega l., corrado s., di leo p., giampaolo c., invernizzi c., martino c., mazzoli s., schiattarella m. & zattin m. (2005) the southern apennines case history: thermal constraints and reconstruction of tectonic and sedimentary burials. atti ticin. sc. terra, serie spec., 10, pp. 45-53. avena g.c., giuliano g. & lupia palmieri e. (1967) sulla valutazione quantitativa della gerarchizzazione ed evoluzione dei reticoli fluviali. boll. soc. geol. it., 86, pp. 781-796. boenzi f., capolongo d., cecaro g., d’andrea e., giano s.i., lazzari m. & schiattarella m. (2004) evoluzione geomorfologica polifasica e tassi di sollevamento del bordo sud-occidentale dell’alta val d’agri (appennino meridionale). boll. soc. geol. it., 123, pp. 357-372. bonardi g. (1966) osservazioni geologiche sui monti di lauria. boll. soc. natur. in napoli, 75, pp. 181200. bonardi g., amore f.o., ciampo g., de capoa p., miconnet p. & perrone v. (1988) il complesso liguride auct.: stato delle conoscenze e problemi aperti sulla sua evoluzione pre-appenninica ed i suoi rapporti con l’arco calabro. mem. soc. geol. it., 41, pp. 17-35. bousquet j.c. & gueremy p. (1968) quelques phénomènes de néotectonique dans l’apennin calabro-lucanien et leurs conséquences morphologiques. i) bassin du mercure et haute vallée du sinni. rev. géogr. phys. géol. dynam., 10, pp. 225-238. bousquet j.c. & gueremy p. (1969) quelques phénomènes de néotectonique dans l’apennin calabro-lucanien et leurs conséquences morphologiques. ii) l’escarpement méridional du pollino et son piémont. rev. géogr. phys. géol. dynam., 11, pp. 223-236. capaldi g., cinque a. & romano p. (1988) ricostruzione di sequenze morfoevolutive nei picentini meridionali (campania, appennino meridionale). suppl. geogr. fis. dinam. quat., 1, pp. 207-222. catalano s., monaco c., tortorici l. & tansi c. (1993) pleistocene strike-slip tectonics in the lucanian apennine (southern italy). tectonics, 12, pp. 656665. cello g. & mazzoli s. (1999) apennine tectonics in southern italy: a review. journ. geodyn., 27, pp. 191-211. cinque a., patacca e., scandone p. & tozzi m. (1993) quaternary kinematic evolution of the southern apennines. relationships between surface geological features and deep lithospheric structures. annali di geofisica, 36, pp. 249-260. d’argenio b., ietto a. & oldow j.s. (1986) low angle normal faults in the picentini mountains, southern appennines. rend. soc. geol. it., 9, pp. 113-122. dewey j.f., helman m.l., turco e., hutton d.h.w. & knott s.d. (1989) kinematics of the western mediterranean. in: coward m.p., dietrich d. & park r.g. (eds), alpine tectonics, geol. soc. spec. publ., 45, pp. 265-283. di leo p., schiattarella m., cuadros j. & cullers r. (2005) clay mineralogy, geochemistry and structural setting of the ophiolite-bearing units from southern italy: a multidisciplinary approach to assess tectonic history and exhumation modalities. atti ticin. sc. terra, serie spec., 10, pp. 87-93. ferranti l., oldow j.s. & sacchi m. (1996) prequaternary orogen-parallel extension in the southern apennine belt, italy. tectonophysics, 260, pp. 325-347. ferreli l., michetti a.m., serva l., vittori e. & zambonelli e. (1996) tettonica recente ed evidenze di fagliazione superficiale nella catena del pollino (calabria settentrionale). mem. soc. geol. it., 51, pp. 451-466. firpo m. & spagnolo m. (2000) morphometric analysis of sansobbia river basin (liguria, italia) and tectonic implications. geogr. fis. dinam. quat., 24, pp. 57-63. ietto a. & d’argenio b. (1990) some accounts on thrust and subsequent extensional tectonics in the pollino mountains. southern apennines. rend. soc. geol. it., 13, pp. 121-124. knott s.d. (1987) the liguride complex of southern italy – a cretaceous to paleogene accretionary wedge. tectonophysics, 142, pp. 217-226. la rocca s. & santangelo n. (1991) nuovi dati sulla stratigrafia e sull’evoluzione geomorfologica del 141caratteri morfotettonici dell’area ... bacino lacustre pleistocenico del fiume noce (basilicata). geogr. fis. dinam. quat., 14, pp. 229242. lorenzo p., schiattarella m., sdao f. & tansi c. (2001) inquadramento geologico e condizioni di stabilità dei versanti dell’area interessata dal sisma del 9 settembre 1998. in: “dissesti prodotti o aggravati dal sisma del 9 settembre 1998 nei territori del confine calabro-lucano” a cura di gulla’ g. & sdao f., cnr-gndci, 2121, pp. 9-37. marra f. (1998) evidenze di tettonica trascorrente alto pleistocenica al confine calabro-lucano: analisi morfostratigrafica e strutturale del bacino del mercure. il quaternario, 11, pp. 201-215. mauro a. & schiattarella m. (1988) l’unità silentina di base: assetto strutturale, metamorfismo e significato tettonico nel quadro geologico dell’appennino meridionale. mem. soc. geol. it., 41, pp. 1201-1213. molin p., pazzaglia f.j. & dramis f. (2004) geomorphic expression of active tectonics in a rapidly-deforming forearc, sila massif, calabria, southern italy. am. journ. sci., 304, pp. 559-589. palmentola g., marchese f. & vignola n. (1980) dati e considerazioni sulla neotettonica dell’area dei fogli 199 (potenza) e 210 (lauria). c.n.r. contributi conclusivi per la realizzazione della carta neotettonica d’italia progetto finalizzato geodinamica – sottoprogetto neotettonica, pubbl. n. 269, pp. 135-153. perri e. & schiattarella m. (1997) evoluzione tettonica quaternaria del bacino di morano calabro (catena del pollino, calabria settentrionale). boll. soc. geol. it., 116, pp. 3-15. pescatore t., renda p., schiattarella m. & tramutoli m. (1999) stratigraphic and structural relationships between meso-cenozoic lagonegro basin and coeval carbonate platforms in southern apennines, italy. tectonophysics, 315, pp. 269286. pieri p., vitale g., beneduce p., doglioni c., gallicchio s., giano s. i., loizzo r., moretti m., prosser g., sabato l., schiattarella m., tramutoli m. & tropeano m. (1997) tettonica quaternaria nell’area bradanico-ionica. il quaternario, 10, pp. 535-542. russo f. & schiattarella m. (1992) osservazioni preliminari sull’evoluzione morfostrutturale del bacino di castrovillari (calabria settentrionale). studi geol. camerti, vol. spec., 1992/1, pp. 271-278. schiattarella m. (1996) tettonica della catena del pollino (confine calabro-lucano). mem. soc. geol. it., 51, pp. 543-566. schiattarella m. (1998) quaternary tectonics of the poll ino ridge, calabria-lucania boundary, southern italy. in: holdsworth r.e., strachan r.a., dewey j.f. (eds), “continental transpressional and transtensional tectonics”. geological society, london, spec. publ., 135, pp. 341-354. schiattarella m., di leo p., beneduce p. & giano s.i. (2003) quaternary uplift vs tectonic loading: a case-study from the lucanian apennine, southern italy. quaternary international, 101-102, pp. 239251. schiattarella m., di leo p., beneduce p., giano s.i. & martino c. (2006) tectonically driven exhumation of a young orogen: an example from the southern apennines, italy. in: willett s.d., hovius n., brandon m.t., fisher d. (eds), “tectonics, climate, and landscape evolution”. geological society of america, spec. papers, 398, pp. 371385. schiattarella m., torrente m.m. & russo f. (1994) analisi strutturale ed osservazioni morfostratigrafiche nel bacino del mercure (confine calabro-lucano). il quaternario, 7, pp. 613-626. turco e., maresca r. & cappadona p. (1990) la tettonica plio-pleistocenica del confine calabro-lucano: modello cinematico. mem. soc. geol. it., 45, pp. 519-529. vezzani l. (1967) osservazioni sul bacino lacustre del fiume mercure . atti acc. gioenia sc. nat. catania, 18, pp. 229-235. 142 ms. ricevuto il 6 giugno 2006 testo definitivo ricevuto il 17 ottobre 2006 ms. received: june 6, 2006 final text received: october 17, 2006 d. gioia & m. schiattarella imp.giraudi mmiiddddllee pplleeiissttoocceennee ttoo hhoolloocceennee aappeennnniinnee ggllaacciiaattiioonnss ((iittaallyy)) ccaarrlloo ggiirraauuddii enea, p.o. box. 2400, 00100 roma a.d. abstract knowledge of the apennine glaciations may be summarized as follows: it is certain that in the apennines there are traces of at least one glacial expansion older and more extensive than that of the last glacial maximum (lgm). its age is not known in detail, but it is highly likely that it dates from the final part of the middle pleistocene. an additional earlier glacial phase might also be represented. the late pleistocene glaciation has left few traces relating to marine isotope stage 4, but abundant sediments and features relating to the lgm and to its recessional phases are found. radiometric dating of these glacial oscillations is still rather scanty. in the last few years tephra layers and some eolian deposits have been found which, being isochronous, make it possible to obtain a chronological setting and a precise correlation even between the moraines situated at latitudes and elevations very different from one another. the late pleistocene lgm glaciers started to expand earlier than 22,680±630 14c years bp (campo imperatore stadial), and began to retreat slowly around 21,500 14c years bp, and then more rapidly until about 17,000 14c years bp. after 17,000 years bp there was a readvance. this fontari stadial was followed by recessional phases lasting until after 11,760 ±160 14c years bp. another readvance followed, the mount aquila stadial, which may be correlated with the younger dryas. the recessional phases of this stadial are probably represented by the earliest holocene moraines: later the glaciers melted. they reformed in the second half of the holocene (calderone stadial) after 3890±60 14c years bp, and re-expanded after ca. 2650±60, 1450±40, 670±40 14c years bp and reached their maximum length during the little ice age. the calderone glacier, the only one that now exists in the apennines, has strongly melted back in the 20th century. riassunto le conoscenze relative alle glaciazioni dell'appennino possono essere sintetizzate nel modo seguente. e' sicuro che sull'appennino vi sono le tracce di almeno una espansione glaciale più estesa di quella dell‘ultimo massimo glaciale: la sua età non è nota in dettaglio, tuttavia è molto probabile che risalga al pleistocene medio, forse alla sua parte finale. potrebbe essere documentata anche una fase glaciale precedente, per la quale risulta difficile una attribuzione cronologica. la glaciazione del pleistocene superiore ha lasciato poche tracce relative allo stadio isotopico 4, ma moltissimi depositi e morfologie relativi all‘ultimo massimo glaciale ed alle sue fasi di ritiro. i ghiacciai della fase finale del pleistocene superiore si sono espansi a partire da un momento precedente a 22,680±630 anni 14c bp (campo imperatore stadial), ed hanno cominciato a ritirarsi lentamente attorno a 21,500 anni 14c bp, e poi, più velocemente, fino a circa 17,000 anni 14c bp. in un periodo poco più recente di 17,000 anni 14c bp vi fu la riespansione glaciale denominata fontari stadial, seguita da fasi di ritiro che durarono fino ad un momento più recente di 11,760±160 anni 14c bp. si verificò poi la riespansione glaciale denominata m. aquila stadial, correlabile al younger dryas: le fasi di ritiro di questo stadio dovrebbero essere rappresentate dalle prime morene oloceniche. per quel che riguarda le espansioni glaciali oloceniche e la neoglaciazione occorre tenere presente che i dati sono scarsi poiché le località studiabili sono pochissime e ristrette alle porzioni più elevate dei due massicci più elevati dell'appennino. i ghiacciai presenti nella fase iniziale dell'olocene scomparvero e si riformarono poi nella seconda metà dell'olocene in un periodo più recente di 3890± 60 anni 14c bp, furono soggetti a varie fasi di espansione dopo 2650±60, 1450±40, 670±40 anni bp (calderone stadial) e raggiunsero la loro massima lunghezza nel corso della piccola età glaciale. il ghiacciaio del calderone, l'unico attualmente presente sull'appennino, ha mostrato nel corso del xx secolo una forte riduzione di volume ed appare sull‘orlo dell‘estinzione. key words: apennines, glaciations, middle pleistocene, late pleistocene, holocene. il quaternario italian journal of quaternary sciences 1166(1bis), 2003, 37-48 iinnttrroodduuccttiioonn the apennines form the backbone of the italian peninsula, extended into the mediterranean sea between 38° n and about 44°30’ n (fig. 1). traces of former glaciation have been known for the apennines since the 19th century and have been the subject of many investigations. in the present work, however, only the most recent studies will be taken into consideration. the highest peaks in the apennines are found in the central sector, between about 42°50’ n and 41°30’ n where they include the gran sasso (2912 m), maiella (2793 m), velino (2486 m), sibillini (2476 m) and laga (2458 m) massifs, but numerous other peaks exceed 2000 m. in contrast, the mountains of the northern apennines exceed 2000 m only at mounts cusna (2121 m), cimone (2165 m) and prato (2054 m), and the mountains of the southern apennines exceed 2000 m only in mounts sirino (2005 m) and pollino (2266 m). at present only a single small glacier which is rapidly melting is found in the apennines: the calderone glacier in the gran sasso. until around 15 years ago, the study of the apennine glaciations was limited to examination of the glacial features, the weathering of the till and calculation of the equilibrium line altitude (ela) of the former glaciers. the chronological framework of the glacial phases relied largely on the correlation between the local ela and those of the alps. it is only since 1989 that the use of 14c dates and of tephra layers (frezzotti & narcisi, 1989, frezzotti & giraudi, 1989) has made it possible to date the glacial deposits directly, although as yet only 38 c. giraudi very few dates are available. in the apennines there are traces of at least two glaciations: the most ancient ones, while certain, are rather scanty, whereas traces of the most recent glaciation are very abundant and well preserved. the great majority of the glaciers were present in valleys and glacial cirques orientated towards the north, while only a few developed in valleys orientated towards the west and the east, and hardly any occurred in valleys with a southern alignment. mmiiddddllee pplleeiissttoocceennee ggllaacciiaattiioonn it is only recently that the traces of an early glaciation were identified with certainty (federici, 1977). since the glacial stratigraphy of the apennines has been correlated with that of the alps, the oldest moraines have been attributed to the rissian glaciation or to a generic pre-würmian event. pre-würmian moraines have been reported from the northern apennines, in the area of mount navert (federici, 1977; jaurand, 1994, 1998), and in the central apennines, at sibillini massif (coltorti & farabollini, 1995), at campo imperatore in the gran sasso massif (giraudi, 1994; jaurand, 1994, 1998; giraudi & frezzotti, 1997; bisci et al., 1999), in various places of the velino massif (cassoli et al., 1986; giraudi, 1998b) and at mount greco (frezzotti & giraudi, 1989; cinque et al. 1990). according to damiani & pannuzi (1991), however, the 'rissian' moraines at mount greco should be attributed to the early würmian glaciation. judging from the distribution of till in the central italian massifs, the extension of the glaciers during this period must have exceeded that of the last glacial maximum (lgm) by some 5 10%. it is not possible to assess the ela of the glaciers because the apennine chain has been affected by intense neotectonic movements, and it is likely that the characteristics of the catchment areas of the glaciers have changed considerably. overall the data are so scanty that no glacial limits can be mapped. according to kotarba et al. (2001), uranium series datings have been done on calcite crystals included in fig. 1 location of the apennine chain and of the main mountain massifs. legend: 1 areas above 1000 m; 2 present shoreline; 3 last glacial maximum shoreline. moraine deposits at campo imperatore: the ages of 121 (+13/-12) and 135 (+10/-9,7) allow the authors to assume a late-middle pleistocene age for the older glaciation phase. in a recent study (giraudi, 1998b) of the campo felice area in the velino massif (central apennines), the relative age of some of the older moraines were determined. these 'rissian' glaciation moraines are overlain by aeolian deposits which mainly include volcanic minerals. they contain a palaeosol. in addition, these deposits have also yielded a mousterian chert artefact. in central italy mousterian cultural remains occur from at least marine isotope substage 5e (i.e. eemian) and unti l the end of mis 4 (i.e. middle würmian). since the moraines predate the aeolian deposits, the palaeosol and the artefacts, it is highly improbable that the ice advance occurred during mis 4 and 5 (i.e. early or middle würmian). the first major ice advance in the apennines must therefore date at least from one of the cold stages preceding mis 5e; it must be middle pleistocene. because the moraines are fairly well preserved, a late middle pleistocene age is most likely (i.e. potentially mis 6 or 8). according to jaurand (1994, 1998), the mount navert moraine, another pre-würmian feature that was preserved in a palaeolandscape, may be even older. it might indicate glaciation of the apennines before the late middle pleistocene. uuppppeerr pplleeiissttoocceennee ggllaacciiaattiioonn,, tthhee llaasstt ggllaacciiaall mmaaxxiimmuumm aanndd iittss rreettrreeaatt pphhaa-sseess traces of the upper pleistocene glaciation have been reported in a number of papers, but only the most recent will be considered. the considered works on the northern apennine glaciers are: bertolini & trevisan (1984), braschi et al. (1986), castaldini et al. (1998), federici (l977, 1978, 1981), federici & scala (1966), federici & tellini (1983), gabert (1962), giglia (1967), gruppo ricerca geomorfologia (1982), jaurand (1994, 1998), losacco (1982), nardi (1961), pelletier (1959), suter (1950) and trevisan et al. (1971). the works on the central apennines glaciers are by bally (1954), biasini (1966), brancaccio et al. (1980), cassoli et al. (1986), castaldo (1965), catenacci (1974), cinque et al. (1990), damiani (1975), damiani & pannuzi (1976, 1979, 1985-1986 a,b, 1991, 1993), demangeot (1965), dramis & kotarba (1994), dramis et al. (1987), dramis et al. (1980), federici (1979, 1980), frezzotti & giraudi (1989, 1990, 1992), frezzotti & narcisi (1989, 1996), giraudi (1988, 1989a, 1989b, 1992, 1994, 1997a, 1997b, 1997c, 1997d, 1998 a, 1998b, 1998c, 1998d, 2000), giraudi & frezzotti (1995, 1997), jaurand (1994, 1998), mongini (1970), palmentola et al. (1990), pfeffer (1967), praturlon (1968), raffy (1983), rasse (1994) and tagliaferro (1982). the works on the southern apennines glaciers are by boenzi & palmentola (1971, 1972a, 1972b, 1974, 1975), giraudi (1998f), lippmannprovansal (1987), palmentola & acquafredda (1983), palmentola et al. (1990) and palmentola & pennetta (1979). savelli et al. (1995) report the presence of glacial 39middle pleistocene to ... remains on mount catria (1700 m a.s.l., north-central apennines). as the authors point out, the glacial traces on mount catria are somewhat problematic and they lack age control. the glacier is said to have developed in a south-facing valley and its front must have reached down to an extremely low level (about 580 m a.s.l.), far lower than the levels reached by the major glaciers of the northern apennines with a northern exposure. glacial landforms are absent from the highest peak of the mountains, which is exposed to the west, and is theoretically best suited to support a glacier. therefore, this supposed past glacier cannot be discussed until new evidence becomes available. upper pleistocene glacial morphological features and deposits can almost exclusively be dated to the last glacial maximum and its retreat phases. older outwash sediments have only been identified (frezzotti & giraudi, l992) from the margins of the velino massif (central apennines). these sediments predate a fossil soil on volcanic material, dated to 33,140±1700 14c years bp and developed, probably, during marine isotopic stage 4. the most recent summaries of data on the late pleistocene glaciation of the apennines were presented by federici (1979) for the central and northern apennines, palmentola et al. (1990) for the southern apennines and jaurand (1994, 1998) for the whole mountain range. federici (1979), using the degree of preservation of the landforms, but without any radiometric dates, correlated the moraines of the maximum ice advance of the central apennines to the 'würm iii' of the alps. this expansion was related by him to between c. 21,000 and 18,000 years bp. he also differentiated various successive retreat stages: apennine stage 1, correlated with the alpine altstadien, which is marked by a rise of the equilibrium line altitude (ela) of 110-240 m; apennine stage ii, correlated with the bühl-schlern stages of the alps, with ela 300 m higher than 'würm iii'; apennine stage iii, correlated with the gschnitz of the alps, with ela about 600 m higher than 'würm iii'; apennine stage iv, correlated tentatively with the daun of the alps, with ela about 700-800 m higher than 'würm iii'. according to panizza (1985), the alpine bühlschlern and gschnitz stages are included in the oldest dryas, while the daun corresponds to the older dryas. in the southern apennines, palmentola et al. (1990), again in the absence of absolute dates, correlated the maximum ice advance to the alpine würm iii and distinguished three successive retreat stages: apennine stage 1, which they correlated with the oldest dryas, with an ela of about 150-170 m higher than würm iii; apennine stage ii, which they correlated with the older dryas, in which an ela of about 300 m higher than in würm iii was determined, and apennine stage iii, which they correlated with the younger dryas, with an ela about 400 m higher than during würm iii. later, frezzotti & giraudi (1989, 1992) dated the late-glacial climatic phases in the area of mount greco and the outwash sediments of mount velino (central apennines). for the first time they were able to demonstrate that the apennine lgm was more recent than a 40 series of depositional and erosional events younger than c. 30,000 14c years bp but older than c. 15,000 14c years bp. lowe (1992) dated lacustrine sediments behind a number of stadial moraines in the northern apennines. following study of the glacial events throughout the apennines, jaurand (1994, 1998) based his synthesis on a number of radiocarbon dates reported in frezzotti & giraudi (1989, 1992) and lowe (1992). jaurand (1994, 1998) attributed the lgm moraines to an ice advance which reached its maximum around 19,000 14c years bp. he recognized four successive stages: apennine stage i, which corresponded to a rise of the ela of 50-125 m; apennine stage iia, correlated with the oldest dryas, older than 13,000 14c years bp, with a rise of the ela of 250-300 m; apennine stage iib, which he correlated with the younger dryas, with a rise of the ela of about 400 m and apennine stage iii, correlated with the preboreal, with a rise of the ela of 550-600 m with respect to that of the last glacial maximum (lgm). regarding the southern apennines, jaurand (1994, 1998) denies, on the basis of sedimentological and morphological evidence, the glacial origin of deposits in calabria, south of mount pollino formerly postulated by boenzi & palmentola (1972b, 1974, 1975b). more recently, giraudi (1997a, 1997b, 1997c, 1997d, 1998 a, 1998b, 1998c, 1998d, 2000, in the press) and giraudi & frezzotti (1997) carried out more detailed investigations on a number of massifs in the central apennines (gran sasso; greco, terminillo, velino, maiella, breccioso, matese) and in the southern apennines (sirino and pollino). on the gran sasso massif, thanks to a series of radiocarbon dates and the neapolitan yellow tuff tephra (recognized by frezzotti & narcisi, 1989, 1996), giraudi & frezzotti (1997) were able to date various phases of the lgm (campo imperatore stadial). the longest glacier in the apennines had already reached its maximum extent before 22,680±630 14c years bp. its glacier tongue blocked a small tributary valley, damming a proglacial lake. glacial retreat began around 21,450±250 14c years bp, when outwash was deposited. a further phase of intense glacial melting is again dated from outwash deposits to a little less than 17,840±200 14c years bp. moreover, many recessional moraines are recognized: all of which, except the highest on mount aquila, predate the neapolitan yellow tuff tephra, dated at 12,300±300 14c years bp (alessio et al., 1973). the authors were able to distinguish two interstadial periods, the fornaca interstadial, at 1617,000 14c years bp, and the venacquaro interstadial, radiocarbon-dated to 13,000 11,000 years bp. giraudi & frezzotti (1997) summarize the sequence of events as follows: • in addition to the last glacial maximum (lgm) moraines of the campo imperatore stadial, on the gran sasso there are three recessional moraines that predate the fornaca interstadial. • afterwards these interstadial glaciers readvanced during the fontari stadial. a set of three recessional moraines formed prior to the subsequent venacquaro interstadial. • this was followed by a minor glacial readvance in the monte aquila stadial, after 11,760±160 and before 8035±140 14c years bp, which may be correlated with the younger dryas. despite having no new 14c dates available, giraudi (1997a, 1997b, 1997c, 1997d, 1998a, 1998b, 1998c, 1998d, 2000) in his studies of other massifs in the central-southern apennines recognized a number of stratigraphic markers (tephra and aeolian sediments) which are fundamental for the dating and correlation of the glacial events on the different massifs. later on, new data about tephra layers found on glacial debris allowed the number of stratigraphic markers, described below, to be improved. in all the glaciated areas studied (except for the gran sasso and majella), the most recent moraines (ela some 400-475 m higher than that of the lgm) are overlain by the neapolitan yellow tuff tephra, radiocarbon dated 12,300±300 14c years bp (alessio et al., 1973). on the matese massif (central apennines) a tephra layer predating the neapolitan yellow tuff overlies moraines which indicate a rise of the ela of c. 300 m with respect to the lgm. the tephra was analyzed by narcisi (2000, personal communication) using sem analysis: the chemical composition appears very similar both to the tephra of the "greenish" and "basale" eruptions of mount vesuvius. near the volcano, the products of the "greenish" eruption cover palaeosols dated 15,500±170 and 14,420±160 14c years bp (santacroce, 1987), and the tephra of the "basale" eruption covers palaeosols dated 16,250±130 and 17,050±40 14c years bp (delibrias et al., 1979) in all glaciated areas, at the bottom of closed depressions on glacial debris, a layer of loess was found. on mounts greco and matese (central apennines) and on mount sirino (southern apennines), this loess consists mainly of quartz. it is the only loess with such a mineralogical composition known in the centralsouthern apennines in the last 30,000 years bp. here it overlies moraines which indicate a rise of the ela of c. 200-280 m with respect to the lgm, but is not present on the younger ones. the precise age of this loess, identified for the first time by frezzotti & giraudi (1989, 1990), is lacking, but its dating is based on the following criteria: • on the aremogna plain (mount greco central apennines) the loess lies on outwash sediments deposited during the lgm recession. on the basis of the data collected by giraudi & frezzotti (1997) on the gran sasso massif, the outwash deposits were, partly, formed after 17,840±200 14c years bp. at the fucino plain, the deposition of outwash sediments from the glacier of the velino massif ended around 17,380±160 14c years bp when the lake covered a soil and produced erosion on such deposits (giraudi, 1998g). on the aremogna plain, the loess, which has been subject to soil formation, was redeposited as colluvium and subsequently overlain by peat dated at 12,850±200 14c years bp (frezzotti & giraudi, 1989). • on mount matese (central apennines) the loess is older than the tephra layer (giraudi, 1997a). similar to the products of the "greenish" and "basale" eruption of vesuvius, datable at c. 14,000-15,000 and 16,000-17,000 14c years bp. the cerchio tephra, a tephra of as yet unknown oric. giraudi 41 gin, was identified on the moraines of the first recessional phases after the lgm (with an ela some 125 m higher than at the lgm) of mount breccioso (central apennines). the first products of tephra reworking have been dated in the nearby fucino plain (giraudi, 1995) at 19,100±650 14c years bp. about the tephra layers that predate neapolitan yellow tuff on the matese massif, and overlie the quartz-rich loess, one can observe that, due to the age of the eruption, there is little probability that it corresponds to the "basale" eruption of vesuvius. the "basale" covers palaeosols dated 16,250±130 and 17,050±40 14c years bp and seems too old to fit in with the chronology of the glacial phases suggested by other datings. otherwise one must assume that during the short period between 17,380±160 and 16,000 – 17.000 14c years bp a glacial re-expansion occurred, with the sedimentation of the quartz-rich loess, and a new retreat phase. it is therefore assumed that the tephra predating the neapolitan yellow tuff on the matese massif pertains to the "greenish" eruption of vesuvius, younger than palaeosols dated 15,500±170 and 14,420±160 14c years bp . following this assumption, one can date the quartz-rich loess, covering moraines of a glacial stadial when ela was 200-280 m higher with respect to the lgm, to a period around or slightly younger than 16,000 14c years bp. using radiocarbon dating and the chronological data stated above, a chronology of the apennine last glacial maximum and its retreat phases has been obtained (fig.2). the maximum glacial extent, i.e. the campo imperatore stadial, was reached just before 22,680 ±630 14c years bp and lasted until ca. 21,450±250 14c years bp. during lgm, ela on the apennines was conditioned by latitude and valley exposures, and varied between 1250 and 1900 m a.s.l. about 21,450±250 14c years bp the glaciers started the early phases of retreat, that lasted until 17,840±200 14c years bp. in this period at least two retreat moraines were formed, produced by glaciers having ela 15-125 and 110-200 m higher than lgm; nevertheless in some massifs the retreat moraines can be three or more because of local topographic reasons. around 17,840±200 14c years bp a very marked retreat phase took place, and a large amount of outwash sediments was produced: such a rapid glacier melting must have been due to a strong climatic change, i.e. to the occurrence of an interstadial (fornaca interstadial). the glacier melting ceased around 17,380±160 14c years bp, when a new stadial advance took place (fontari stadial). during this stadial the last valley glaciers were present on the higher massifs, and ela was 200-280 m higher than during lgm. starting from 16,000 14c years bp, a glacial reduction took place. two retreat moraines were formed: the former, dated about 15.000-16.000 14c years bp, by glaciers having ela 290-390 m higher than during lgm, and the latter, dated around 14,000 14c years bp, by glaciers having ela 400-475 m higher than during lgm. between 12,850±200 14c years bp and at least 11,760±160 14c years bp, the lack of glacial remnants and the presence of lakes in some former glacial cirques (giraudi & frezzotti, 1995) suggest a very small extension of the glaciers. this time lapse is called venacquaro interstadial and corresponds to the böllingalleröd interstadial. later, between 11,760±160 and 8035±140 14c years bp, a new small glacial advance took place (m. aquila stadial) corresponding to the younger dryas chron. it is clear that the dates obtained generally show an earlier age for the glacial events than assumed before. hhoolloocceennee nneeooggllaacciiaattiioonn the presence of glaciers in the apennines during the holocene is shown by the calderone glacier. this glacier, located on the gran sasso massif, is the southernmost in europe (gellatly et al.,1994). it is found at an elevation above c. 2670 m in a cirque situated on the northern slope of the corno grande (2912 m). its tongue is rapidly melting and is almost completely covered by debris, but it was still some 15 m thick in its lower part (gellatly et al.,1994; fiucci et al., 1997). the glacier is situated at the head of the cornacchie valley. here new investigations have begun; in the upper part there are some moraines, which were formed by glaciers with an ela more than 800-1050 m higher than that of the lgm. they must be of holocene age, because the younger dryas ela was at least 250 m lower. there are no precise dates for these oldest holocene moraines: the only chronological indication is provided by a sequence of colluvial sediments and soils overlying the till that include a tephra layer. the tephra, of uncertain provenance, may be correlated mineralogically with the duchessa tephra (giraudi, 2001). this unit has also been found on other moraines in the central apennines, and overlies soils dated to 4390±50 (beta 117017), 4220±80 (beta 106450) and 4020±70 (beta 111004) 14c years bp. the moraines, which indicate a glacier with an ela about 800 m higher than that of the lgm, may possibly represent the recessional phases of the mount aquila stadial dated to the younger dryas chron. the moraines situated at the threshold of the calderone glacier cirque, with their ela about 10001050 m higher than the lgm, have been attributed to the little ice age (lia) by various authors (federici, 1979; jaurand, 1994, 1998; gellatly et al., 1994). in the course of new observations on these moraines, three different tills have been recognized (giraudi, 2000, 2002). the oldest till, almost completely covered by the successive units, has a dark grey matrix of silt rich in organic matter, derived from a soil on volcanic material. its mineralogical composition is analogous to that of the duchessa tephra. the organic matter has been dated to 3890±60 14c years bp. consequently, the glacial advance (calderone 1 stadial) that formed the moraine must be younger than that date and represents the first known apennine neoglacial expansion. in view of the very steep sides of the glacial cirque, the soil could only be derived from the cirque, which is currently occupied by the glacier. therefore, starting from about 4300 14c years bp and until around 3890 ±60 14c years bp, the middle pleistocene to ... 42 c. giraudi fig. 2 chronological framework of the last glacial maximum, late pleistocene and holocene apennine glacial stadials. calderone glacier was absent or was definitely much smaller than at present. but according to others palaeoclimatic data on the central apennines area and the correlations with alpine glacial phases, giraudi (2000) hypotesized that the glaciers on the apennines disappeared about 9000 14c years bp. in order to detect the age of the debris of glacial origin lying just down-valley of the threshold of the cirque of calderone glacier, giraudi (2002) dated the interbedded soils by means of radiocarbon analysis. the datings point out four more glacial expansions: the first (calderone 2) following 2650±60 14c years bp, the second (calderone 3a) bracketed between 1450±40 and 670±40 14c years bp, the tird (calderone 3b) following 670±40 14c years bp, the last one (calderone 3c) datable to the xix century. the calderone 3b expansion, occurred during the little ice age, can be considered the neoglacial maximum. thus, the following sequence of events has been deduced: the early holocene saw the recessional phases of the mount aquila stadial glaciers. after 9000 14c years bp, these glaciers melted completely. subsequently the calderone glacier expanded, after 3890±60, 2650±60, 1450±40, 670±40 14c years bp and during the xix century. moraines colonized by only very little vegetation, are also preserved at high altitudes at a number of valley heads in the maiella massif (central apennines). they have been attributed to the holocene (giraudi, 1998e). at the head of the cannella valley, an extremely small moraine situated at 2540 m is almost completely devoid of vegetation, comparable to the till of the calderone glacier attributed to the lia above-mentioned. it is therefore probable that in this valley a small glacier also formed during the lia. traces of neoglaciation are probably found on only the two highest massifs of the apennines, since the peaks of the other massifs are below the altitude of the calderone stadial moraines. ccoommppaarriissoonn bbeettwweeeenn tthhee aappeennnniinnee,, aallppiinnee aanndd ootthheerrss mmoouunnttaaiinn ggllaacciiaattiioonnss the comparison between the apennines and other mountain chain glacial expansions can be reliable only for lgm and holocene, because the older glaciations lack a suitable chronological framework. the upper pleistocene maximum glacial expansion, dated in the apennines between 22,680±630 and 21,450±250 14c years bp, was not synchronous in the european mountain chains. in the pyrenees lgm occurred in a period older than 38,000 14c years bp, and a secondary glacial expansion took place ca. 26,000 14c years bp (jalut et al. 1992; florinet & schlüchter, 2000). on the massif central, lgm occurred before 28,000 14c years bp, while a minor expansion took place ca. 18,000 14c years bp (etlicher & de goer de hervé, 1988; florinet & schlüchter, 2000). on the jura, lgm is dated between 25,000 and 15,000 14c years bp (campy & richard, 1998). in the northern alpine foreland lgm was reached in a time lapse between 28,000 e 20,000±1800 14c years bp (ivy-ochs, 1996; florinet & schlüchter, 2000), while in the southern alpine foreland it took place between 24,000 and 17,700±360 14c years bp (fliri, 1989, orombelli, 1974; bini, 1997). the lgm datings in the apennines, the alps and the jura are essentially similar. although the beginning of the glacial retreat in the italian alps (17,700±360 14c years bp according to orombelli, 1974) clashes with the start of the fast retreat of the apennine glaciers (ca.17,840±200 14c years bp), in the apennines a slow glacial melting occurred after ca 21,450±250 14c years bp. the early apennine glacial retreat was produced by a climatic change from cold and wet to cold and dry (giraudi & frezzotti, 1997). this change probably occurred only in the italian peninsula, not in the alps, or the climate change was weak and not able to affect the alpine glacial system having greater inertia. according to florinet & schlüchter (2000) the different chronological framework for the pyrenees and the vosges lgm is the consequence of palaeoclimatic condit ions l inked to some differences in the upper pleistocene atmospheric circulation. about holocene, baroni & orombelli (1996), orombelli & mason (1997), grove (1997), grove & gellatly (1997) and jania (1997) report that between 9000 and 8000 14c years bp in the alps, the pyrenees and the tatramountains, the largest glaciers were smaller than today and the smallest ones melted: strong glacial expansion took place only after 5000 14c years bp. during the same period the calderone glacier melted, leaving the apennines without glaciers. the same glacier, lying at both a lower altitude and latitude than other mountain glaciers, reappeared only in a period more recent than 3895±65 14c years bp, when ela went down to a height lower than the gran sasso peak. grove (1997), in a paper on the holocene european glacial phases, reports glacial advances in the alps ca. 3000-3600, 2100-2600 14c years bp, 800900 ad, and much glacial expansion since 1350 ad. these glacial expansions can be correlated with the calderone stadials 1, 2, 3a, 3b, 3c. in particular, about the italian alps, orombelli & pelfini (1985) report an advance of the forni glacier (ortles-cevedale massif) older than peat dated 2670±130 14c years bp, which can be correlated to the calderone stadial 1. in the pisgana glacier (adamello massif) a glacial expansion took place between 3015±75 and 2345±125 14c bp (baroni & carton, 1991) coincident with the calderone stadial 2. the brenva glacier (mt. bianco massif) advanced (orombelli & porter,1982) and the moraines covered a tree dated 1170±75 14c years bp (760÷980 cal. ad); strumia (1997) found some soil dated 1185±80 14c years bp (734÷980 cal. ad), buried because of the advance of the lys glacier (mt. rosa massif). these glacial advances can be correlated with the calderone stadial 3a. in the alps, starting from the xv century, i.e. during the little ice age, a great deal of glacier expansions took place (for a synthesis see baroni, 2000) which can be coeval, on the whole, to the apennine calderone stadial 3b,3c. 43middle pleistocene to ... ccoonncclluussiioonnss in the apennines the main phases of glacial expansion occurred in the middle pleistocene (probably during the marine isotopic stage 6 or 8) and in the late pleistocene lgm. the middle pleistocene glaciers were 5-10% larger that the upper pleistocene ones during lgm, some glaciers reached an altitude of 700-800 m a.s.l.. the ela value was between 1250 and 1900 m a.s.l., changing according to the altitude, latitude, exposition of the glacial valleys, amount of snow precipitation etc., and according to the distribution of land and seas as pointed out by messerli (1967) for the mountains surrounding the mediterranean sea. ela varied between 1250 and 1550 m, 1550 and 1900, 1600 and 1800 in the northern, central and southern apennines. messerli (1967;1980) calculated the present day snow limits in the northern (ca. 3000 m 44 c. giraudi fig. 3 glacial stadials and equilibrium line altitude (ela) variations from last glacial maximum to the early holocene. the data from the northern apennines stadial ela’s are based on val parma glaciers facing north (from jaurand, 1994, 1998). maximum and minimum ela values reported for the central and southern apennines depend on the different massifs and valley orientations. in the southern apennines, the glaciers melted earlier than in the northern apennines despite the maximum elevation being higher. in the northern apennines the ela is clearly lower than in the central apennines, while there is only a small difference between the central and southern apennines. a.s.l), central (ca. 3220 m a.s.l), and southern apennine (ca. 3330 m a.s.l). as well as during the lgm, the difference between northern and central apennine is bigger than between the central and southern apennine. the moraines are preserved better in the calcareous central and southern apennines than in the northern, formed mainly by marly and arenaceous sediments. in spite of the different data-base, a comparison between the sectors of the apennines chain can be made. in the central apennines, reaching the maximum altitude, the glaciers lasted until the early holocene (fig. 3); later they disappeared but the calderone glacier reappeared and reached its maximum neoglacial length during the little ice age; the same glacier, although very small and completely covered by debris, lies in a portion of the gran sasso high cirque even today. during lgm, the northern apennines ela was lower than in the central and southern sectors. in spite of the elevation of the mountains, in the southern apennines the glacier melted earlier (about 15,000 14c years bp) than in the northern part, where glaciers disappeared about 13,000 14c years bp (fig. 3). according to the published datings, the apennine late pleistocene and holocene glacial advances and retreats were nearly synchronous with the alpine ones: the clearest difference is represented by the early beginning of the lgm apennine glaciers retreat, which started about 21,000 14c years bp. aakknnoowwlleeddggeemmeennttss the present work has been carried out with the financial support of the italian ministry for environment in the frame of the “accordo di programma enea – ministero per l ’ambiente”, project 2.4 – climate variations. rreeffeerreenncceess alessio m., bella f., improta s., cortesi c. & turi b. (1973) university of rome carbon -14 dates, ix. radiocarbon, 1155, 165-178. bally a. (1954) geologische untersuchungen in den se-abruzzen: gebiet zwischen der ebene von sulmona und der taler des pescara und des unteren sangro. zürich, bühler buchdruck, 291 p. baroni c. (2000) il comportamento dei ghiacciai alpini in risposta alle variazioni climatiche oloceniche. il quaternario, 1133 (1), 100-103. baroni c. & carton a. (1991) vedretta di pisgrana (gruppo dell'adamello). geomorfologia e variazioni oloceniche della fronte. natura bresciana, ann.museo civ. sc. nat. brescia, 26. baroni c. & orombelli g. (1996) the alpine iceman and holocene climatic change. quaternary research, 4466,, 78-83. bertolini n. & trevisan l. (1984) ghiacciai würmiani sul monte molinatico (appennino settentrionale). atti della società toscana di scienze naturali, ser. a, 9911, 181-187. biasini a. (1966) elementi morfotettonici, tratti da un rilievo fotogeologico, al margine dell'altipiano di ovindoli (abruzzo). geologica romana, 55, 303312. bini a. (1997) stratigraphy, chronology and paleogeography of quaternary between ticino and olona rivers. geologia insubrica, 22, 21-46. bisci c., ciccacci s., dramis f. & kotarba a. (1999) the extent of pleistocene glaciations in the western part of campo imperatore (gran sasso massif, central italy). landform analysis, 22, 37-43. boenzi f. & palmentola g. (1971) tracce della glaciazione würmiana sul massiccio del pollino al confine calabro-lucano. bollettino società geologica italiana, 9900, 139-150. boenzi f. & palmentola g. (1972a) nuove osservazioni sulle tracce glaciali nell'appennino lucano. bollettino del comitato glaciologico italiano, nuova serie, 2200, 9-52. boenzi f. & palmentola g. (1972b) alcune considerazioni di neotettonica sull'appennino calabro-lucano in base al ritrovamento di tracce glaciali sul m. la mula in calabria. bollett ino della società naturalisti in napoli, 8811, 485-498. boenzi f. & palmentola g. (1974) prima segnalazione di tracce glaciali würmiane nei dintorni di monte botte donato (sila). bollettino società geologica italiana, 9933, 309-315. boenzi f. & palmentola g. (1975a) osservazioni sulle tracce glaciali della calabria. bollettino società geologica italiana, 9944,, 961-977. boenzi f. & palmentola g. (1975b) effetti di fenomeni glaciali quaternari nella calabria nord-occidentale. bollettino società geologica italiana, 9944,, 871-875. brancaccio l., sgrosso i., cinque a., orsi g., pece r. & rolandi g. (1980) lembi residui di sedimenti lacustri pleistocenici sul versante settentrionale del matese presso s. massimo. bollettino società naturalisti in napoli, 8888, 275-286. braschi s., del freo p. & trevisan l. (1986) ricostruzione degli antichi ghiacciai sulle alpi apuane. atti società toscana di scienze naturali, ser. a, 9933,, 203-219. campy m. & richard h. (1988) modalitè et chronologie de la dèglaciation würmienne dans la chainejurassienne. bulletin de l‘association francaise pour l‘etude du quaternaire, 3344--3355, 81-90. cassoli a., corda l., lodoli c., malatesta a., molaroni m. v. & ruggeri a. (1986) il glacialismo quaternario del gruppo velino-ocre-sirente. memorie società geologica italiana, 3355, 855-867, 5 ff. castaldini d., caredio f. & puccinelli a. (1998) geomorfologia delle valli del rio delle pozze e del torrente motte (abetone, appennino toscoemiliano). geografia fisica dinamica quaternaria, 2211,, 177-204. castaldo g. (1965) sul glaciale del m. miletto (massiccio del matese). bollett ino società naturalisti in napoli, 7744, 193-203. catenacci v. (1974) note illustrative della carta geologica d'italia alla scala 1:100,000, foglio 147 lanciano. roma, servizio geologico d'italia, 87 p. cinque a., liccardo c., palma b., pappalardo l., rosskopf c. & sepe c. (1990) le tracce glaciali nel parco nazionale d'abruzzo (appennino centrale): nota preliminare. geografia fisica dinamica quaternaria, 1133,, 121-133. 45middle pleistocene to ... coltorti m. & farabollini p. (1995) quaternary evolution of the „castelluccio di norcia„ basin (umbromarchean apennines, central italy). i l quaternario, 88 (1), 149-166. damiani a.v. (1975) aspetti geomorfologici e possibile schema evolutivo dei m. sibillini (appennino umbro-marchigiano). bollettino servizio geologico d'italia, 9966 (2), 231-314. damiani a.v. & pannuzi l. (1976) la glaciazione würmiana nell'appennino laziale-abruzzese (1) : il ghiacciaio del fosso di s. onofrio nei monti sombruini-ernici. bollettino servizio geologico d'italia, 9977,, 85 106. damiani a.v. & pannuzi l. (1979) la glaciazione würmiana nell'appennino laziale-abruzzese (2) : i ghiacciai della valle granara e della fiumata (alta valle dell 'aniene). bollett ino servizio geologicod'italia, 110000, 287-310. damiani a.v. & pannuzi l. (1985-1986a) la glaciazione würmiana nell'appennino laziale-abruzzese (3): opportunità di precisazioni terminologiche, metodologiche ed introduzione di parametri morfometrici. bollettino servizio geologicod'italia, 110055, 7596. damiani a.v. & pannuzi l. (1985-1986b) la glaciazione würmiana nell'appennino laziale-abruzzese (4): i ghiacciai del gruppo montuoso della genzana (scanno sulmona) e considerazioni neotettoniche. bollettino servizio geologico d'italia, 110055, 97136. damiani a.v. & pannuzi l. (1990) la glaciazione würmiana nell'appennino laziale-abruzzese (5) : i ghiacciai dei m. simbruini (campo ceraso, valle monazzone, fiumata, valle granara) e considerazioni di tettonica recente. memorie descrittive carta geologica d'italia, 3388,, 215-250. damiani a.v. & pannuzi l. (1991) la glaciazione würmiana nell'appennino laziale-abruzzese (6) : i ghiacciai del gruppo del m. greco e considerazioni di tettonica recente (abruzzo). bollettino servizio geologicod'italia, 111100, 111-158. damiani a.v. & pannuzi l. (1993) la glaciazione pleistocenica nell'appennino laziale-abruzzese. nota vi: i ghiacciai del gruppo del m. greco e considerazioni di tettonica recente. bollettino servizio geologicod'italia, cx, 111-158. delibrias g., di paola g.m., rosi m., santacroce r. (1979) la storia eruttiva del complesso vulcanico somma-vesuvio ricostruita dalle successioni piroclastiche del m. somma. rendiconti della società italiana di mineralogia e petrologia. 3355, 411-438. demangeot j. (1965) géomorphologie des abruzzes adriatiques. thèse, paris, c.n.r.s., memoires at documents, numéro hors-série, 403 p. dramis f., coltorti m. & gentili b. (1980) glacial and periglacial morphogenesis in the umbria-marche apennines. abstract, 24th international geographical conference, tokyo, 11 (1), 114-115. dramis f., genti l i b. & pambianchi g. (1987) deformazioni gravitative profonde nell'area di m. gorzano (monti della laga, appennino centrale). bollettino società geologica italiana, 110066 (2), 265271. dramis f. & kotarba a. (1994) geomorphological evidences of high mountain permafrost in central apennine. geografia fisica dinamica quaternaria, 1177, 29-36. federici p.r. (1977) tracce di glacialismo prewürmiana nell'appennino parmense. rivista geografica italiana, 8844 (2),205-216. etlicher b.& de goer de hervé a. (1988) la déglaciation würmienne dans le massif central française: le point des travaux recents. bulletin de l’association française pour l ’etude du quaternaire. 3344--3355, 103-110. federici p.r. (1978) una possibile copertura terziaria dell'unità toscana delle panie (a proposito di una morena di "macigno" nelle alpi apuane). atti società toscana scienze naturali, ser.a,8855, 5159. federici p.r. (1979) una ipotesi di cronologia glaciale würmiana, tardo e post-würmiana nell'appennino centrale. geografia fisica dinamica quaternaria, 22, 196-202. federici p.r. (1980) on the riss glaciation of the apennines. zeitschrift für geomorphologie, 2244 (1), 111-116. federici p.r. (1981) the quaternary glaciation on the seaward side of the apuan alps. rivista geografica italiana, 8888 (2), 183-199. federici p.r. & scala f. (1966) il ghiacciaio würmiano del m. gottero-val gotra (appennino parmense). annali di ricerche e studi di gegrafia, 44 (1),86119. federici p.r. & tellini c. (1983) la geomorfologia dell'alta val parma (appennino settentrionale). rivista geografica italiana, 9900 (3-4), 393-428. fiucci a., gigante b., rossi c., smiraglia c. & veggetti o. (1997) the calderone glacier (gransasso d'italia). determination of ice thickness and bedrock morphology by means of radio-echo sounding. geogr. fis. dinam. quat., 2200, 305-308. fliri f. (1989) eine bestimmung des beginnes der haupt-würmvereisung in zentralraum der alpen (albeins bei brixen). der schlern, 62-65. florinet d. & schlüchter c. (2000) alpine evidence for atmospheric circulation patterns in europe during the last glacial maximum. quaternary research, 54, 295-308. frezzotti m. & giraudi c. (1989) evoluzione geologica tardo-pleistocenica ed olocenica del piano di aremogna (roccaraso abruzzo): implicazioni climatiche e tettoniche. memorie società geologica italiana, 4422, 5-19. frezzotti m. & giraudi c. (1990) late glacial and holocene aeolian deposits and features near roccaraso (abruzzo, central italy). quaternary international, 55, 89-95. frezzotti m. & giraudi c. (1992) evoluzione geologica tardo-pleistocenica ed olocenica del conoide complesso di valle majelama (massiccio del velino abruzzo). il quaternario, 55 (1), 33-50. frezzotti m. & narcisi b. (1989) identificazione di un andosuolo, possibile livello guida per la cronostratigrafia olocenica dell 'appennino centrale. memorie società geologica italiana, 4422, 351-358. frezzotti m. & narcisi b. (1996). late quaternary tephra-derived paleosols in central italy's carbonate apennine range: stratigraphical and paleoclimatological implications. quaternary international 344-46 c. giraudi 3366, 147-153. gabert p. (1962) les plaines occidentales du po et leurs piedmonts. thèse.gap, impr. louis jean, 531 p. gellatly a.f., grove j.m. & smiraglia c. (1992) alcuni risultati di recenti ricerche sul ghiacciaio del calderone (gran sasso d'italia, abruzzo). geogr. fis. din. quat., 1155, 111-113. giglia g. (1967) geologia dell'alta versilia settentrionale (tav. m. altissimo). memorie società geologica italiana, 66, 67-95. giraudi c. (1988) segnalazione di scarpate di faglia post-glaciali nel massiccio del gran sasso (abruzzo): implicazioni tettoniche, rapporti tra tettonica recente e morfologia, paleosismicità. memorie società geologica italiana, 4411,,627-635. giraudi c. (1989a) datazione di un evento sismico preistorico con metodi geologici e radiometrici: piani di aremogna e delle cinque miglia. in: i terremoti prima del 1.000: storia, archeologia, sismologia. istituto nazionale di geofisica,5533--6655. ed. s.g.a. bologna. giraudi c. (1989b) datazione con metodi geologici delle scarpate di faglia post-glaciali di ovindoli piano di pezza (abruzzo italia centrale): implicazioni. memorie società geologica italiana, 4422,, 2939. giraudi c. (1992) segnalazione di scarpate di faglia tardo-pleistoceniche sui monti della magnola (massiccio del velino abruzzo). il quaternario, 55 (1), 27-32. giraudi c. (1994) elementi di geologia del quaternario della piana di campo imperatore (massiccio del gran sasso italia centrale). in atti ticinesi scienze della terra (serie speciale), 22, 137-143. giraudi c. (1995) i detriti di versante ai margini della piana del fucino (italia centrale): significato paleoclimatico ed impatto antropico. i l quaternario, 88 ((1), 203-210. giraudi c. (1997a) dating and correlation of glacial deposits using tephra layers and loess: the example of m. matese (campania-molise) southern italy. studia geomorphologica carpathobalcanica. xxxi, 45-56. giraudi c. (1997b) le oscillazioni tardo-pleistoceniche ed oloceniche del lago effimero del piano di pezza (abruzzo italia centrale). il quaternario, 1100 (2), 191-200. giraudi c. (1997c) i depositi post-glaciali della bassa valle peschio di iorio (pescasseroli, parco nazionale d'abruzzo). datazione ed interpretazione paleoclimatica. il quaternario, 1100 (2), 207-212. giraudi c. (1997d) prima segnalazione dell'apparato glaciale del m. breccioso (val roveto abruzzo): un contributo all'inquadramento cronologico delle fasi glaciali tardo-pleistoceniche. il quaternario, 1100 (2), 201-206. giraudi c. (1998a) alcuni dati per l'inquadramento cronologico delle fasi glaciali tardo-pleistoceniche dei monti greco e serra chiarano (abruzzo italia centrale). il quaternario, 1111 (1), 115-120. giraudi c. (1998b) the late quaternary geologic evolution of campo felice (abruzzo central italy). giornale di geologia, sez. 3, 6600, 67-82. giraudi c. (1998c) i laghi effimeri tardopleistocenici ed olocenici di campo imperatore e del massiccio del gran sasso d'italia (abruzzo italia centrale). il quaternario, 1111 (2), 1-9. giraudi c. (1998d) il glacialismo tardo-pleistocenico del massiccio del terminillo (lazio appennino centrale). il quaternario, 1111 (1), 121-125. giraudi c. (1998e) nuovi dati sul glacialismo della montagna della maiella (abruzzo-italia centrale). il quaternario, 1111 (2), 265-271. giraudi c. (1998f) la deglaciazione tardopleistocenica sui m. sirino e pollino (basilicata, calabria-italia meridionale). il quaternario, 11 (2), 247-254. giraudi c. (1998g) late pleistocene and holocene lake-level variations in fucino lake (abruzzo, central italy) inferred from geological, archaelogical and historical data. in b. frenzel et al (eds.) paleohydrology as reflected in lake-level changes as climatic evidence for holocene times, paläoklimaforschung, bd. 2255, 1-17. giraudi c. (2000) le oscillazioni oloceniche del ghiacciaio del calderone, gran sasso d‘italia (abruzzo italia). il quaternario, 1133 (1-2)31-36. giraudi c. (2001) i sedimenti di riempimento di piccole conche sulle morene dell’appennino centrale: un contributo alla comprensione delle variazioni ambientali post-glaciali. il quaternario, 1144 (2),131136. giraudi c. (2002) le oscillazioni del ghiacciaio del calderone (gran sasso d‘italia, abruzzo – italia centrale) e le variazioni climatiche degli ultimi 3000 anni. il quaternario, 1155 (2), 145-150. giraudi c. & frezzotti m. (1995) palaeoseismicity in the gran sasso massif (abruzzo, central italy). quaternary international, 2255,, 81-93. giraudi c. & frezzotti m. (1997) late pleistocene glacial events in the central apennine, italy. quaternary research, 4488 (3),280-290. grove j.m. (1997) the spatial and temporal variations of glaciers during the holocene in the alps, pyrenees, tatra and caucasus. palaoklimaforschungpalaeoclimate research, 2244,, 95-103. grove j.m.& gellatly a.f. (1997) glacier fluctuactions in the pyrenees in the little ice age and mid holocene. palaoklimaforschung – palaeoclimate research, 2244, 67-83. gruppo ricerca geomorfologia c.n.r. (1982) geomorfologia del territorio di febbio tra il m. cusna e il f. secchia (appennino emiliano). geografia fisica dinamica quaternaria, 55, 285360. ivy-ochs s. (1996) the dating of the rock surfaces using in situ produced 10be, 26al and 36cl, with examples from antarctica and the swiss alps. unpublished ph.d. thesis, eth-zürich, nr. 11763. jalut g., monserrat-marti j., fontugne m., delibrias g., vilaplana j.m. & julia r. (1992) glacial to interglacial vegetation changes in the northern and sothern pyrénées: deglaciation, vegetation cover and chronology. quaternary science reviews, 1111, 449-480. jania j. (1997) the problem of holocene glacier and snow patches fluctuations in the tatra mountains: a short report. palaoklimaforschung palaeoclimate research, 2244, 85-94. jaurand e. (1994) les heritages glaciaire de l'apennin. 47middle pleistocene to ... thèse pour le doctorat dès lettres de l'université de paris i panthéon-sorbonne. 600 pp. jaurand e. (1998) glaciers disparù de l’apennin: géomorphologie et paléoenvironments glaciaires de l’italie peninsulaire. monographie de l’universitè de la sorbonne, geographie, 10, 382 pp. kotarba a., hercman h.& dramis f. (2001) on the age of campo imperatore glaciations, gran sasso massif, central italy. geografia fisica e dinamica quaternaria, 2244 (1), 65-69. lippmann-provansal m. (1987) l'apennin campanien méridional (italie): étude géomorphologique. thèse inédite. université d'aix-marseille. ii, 22tt, 770 p. lowe j.j. (1992) late glacial and early sediments from the northern apennines, italy: pollen stratigraphy and radiocarbon dating. boreas, 2211 (3), 193-208. losacco u. (1982) gli antichi ghiacciai dell'appennino settentrionale: studio morfologico e paleogeografico. atti società naturalisti matematici modena, 111133, 1-224. messerli b. (1967) die eiszeitliche und die gegenwärtige vergletscherung im mittelmeerraum.geografica helvetica, 2222 (3),105-228. messerl i b. (1980) mountain glaciers in the mediterranean area and africa. in: world glacier inventore (proceedings of the riederalp workshop, september 1978), international association of hydrological sciente, pubbl. n. 112266, 197211. mongini g.m. (1970) la morfologia del gruppo orografico del vettore, monti sibillini. roma, istituto di geografia dell'università di roma, pubbl. ser. a, 1100, 43 p. nardi r. (1961) geologia della zona tra la pania della croce, gallicano e castelnuovo garfagnana (alpi apuane). bollettino società geologica italiana, 8800 (2), 257-334. orombelli g. (1974) alcune date 14c per il quaternario lombardo. studi trentini di scienze naturali, 51, 125-127. orombelli g. & mason p. (1997) holocene glacier fluctuations in the italian alpine region.in: glacier fluctuaction during the holocene. palaoklimaforschung palaeoclimate research, 2244, 59-65. orombelli g. & pelfini m. (1985) una fase di avanzata glaciale nell'olocene superiore, precedente alla piccola glaciazione, nelle alpi centrali. rend.soc.geol.it., 88, 17-20. orombelli g. & porter s.c. (1982) late holocene fluctuations of brenva glacier. geogr. fis. dinam. quat.55,13-37. palmentola g. & acquafredda p. (1983) gli effetti dei ghiacciai quaternari sulla montagna del matese, al confine molisano-campano.geografia fisica dinamica quaternaria, 66, 117-130. palmentola g., acquafredda p. & fiore s. (1990) a new correlation of the glacial moraines in the southern appennines, italy. geomorphology, 33, 18. palmentola g. & pennetta l. (1979) le tracce glaciali quaternarie: un aspetto della montagna lucana. atti dell'8 simposio nazionale dell'istituto di zoologia dell'università di bari sulla conservazione della natura, 26-26 aprile 1979, 59-69. panizza m. (1985) schemi cronologici del quaternario. geografia fisica dinamica quaternaria, 88, 44-48. pelletier j. (1959) le relief de l'appenin septentrional: fast et problèmes généraux de la partie occidentallee.. revue de géographie de lyon, 3344 (2), 89-111. pfeffer k.h. (1967) beitrage zur geomorphologie der karstbecken im bereiche des monte velino (zentralapennin). frankfurter geographische hefte, 4422, 86p. praturlon a. (1968) note illustrative della carta geologica d'italia alla scala 1:100.000, foglio 152, sora. roma, servizio geologico d'italia, 76 p. raffy j. (1983) le versant tyrrhenièn de l'apennin central: étude géomorphologique. thèse, saintchamond, impr. g. montet, 442 p. rasse m. (1994) l'apennin ombrien: morphogénèse d'une dorsale récente. thèse ined. université de paris iv sorbonne, 22tt, 538 p. santacroce r. (1987) somma-vesuvio. quaderni del “la ricerca scientifica”, 111144, 8, 252 pp. cnr, roma. savelli d., nesci o. & basili m. (1995) evidenze di un apparato glaciale pleistocenico sul massiccio del catria (appennino marchigiano). geografia fisica dinamica quaternaria, 1188, 331-335. strumia g. (1997) oscillazioni glaciali precedenti la piccola età glaciale documentate da un suolo sepolto in una morena del ghiacciaio del lys. il quaternario, 1100 (2), 153-158. suter k. (1950) die eiszeitliche vergletscherung des nordapennins. vierteljahrsschrift der naturforschenden. gesellschaft in zürich, 9955, 224-241. tagliaferro m.c. (1982) lembo morenico presso arquata del tronto. bollettino società geologica italiana, 110011 (2), 211-218. trevisan l., dallan l., federici p.r. (1971) note illustrative della carta geologica d'italia alla scala 1:100.000, foglio 96, massa. roma. servizio geologico d'italia, 57 p. 48 c. giraudi imp.mozzi ssttrraattiiggrraapphhyy,, ppaallaaeeooppeeddoollooggyy aanndd ppaallyynnoollooggyy ooff llaattee pplleeiissttoocceennee aanndd hhoolloocceennee ddeeppoossiittss iinn tthhee llaannddwwaarrdd sseeccttoorr ooff tthhee llaaggoooonn ooff vveennii-ccee ((iittaallyy)),, iinn rreellaattiioonn ttoo tthhee ccaarraannttoo lleevveell ppaaoolloo mmoozzzzii11,, ccllaauuddiioo bbiinnii22,, lluucciiaa zziilloocccchhii22,, rroobbeerrttoo bbeeccaattttiinnii33,, mmaarrttaa mmaarriioottttii lliippppii33 1 dipartimento di geografia, università di padova, via del santo 26, padova, italy e-mail: paolo.mozzi@unipd.it 2 dipartimento di scienze ambientali, università di venezia, 2137 dorsoduro, venezia , italy. e-mail: bini@unive.it 3 dipartimento di biologia vegetale, università di firenze, via la pira 4, firenze, italy e-mail: mariotti@unifi.it abstract the present investigation brings new stratigraphic, palaeopedological and palynological data deriving from the study of 4 cores, bored to a maximum depth of 15 m in the central sector of the lagoon of venice, along the inner shores, between the mouth of the dese river and porto marghera. in agreement with the general stratigraphy known from previous studies, the lowermost deposits in the cores are fluvial, radiocarbon dated to 21,000 – 18,000 bp. the correlation to the stratigraphic framework of the central veneto plain shows that they belong to the late pleistocene fluvial sedimentary system of the brenta river, the bassano megafan. the pollen record of this alluvium is characterized by typical hydrophilous plants (typha, potamogeton, nymphaea...), which are referred to swampy environments during the last glacial maximum and the late glacial. the compact level known as caranto, located at the top of the fluvial sediments at a depth of some metres from the ground surface, has been recognized as consisting of a set of pedogenetic calcic and gley b and c horizons. this palaeosol formed on the alluvial plain of the distal reaches of the bassano megafan, in the time span comprised between the deactivation of fluvial processes, which took place after 14,500 bp and probably before the beginning of the holocene, and the lagoon transgression. as the latter apparently interested the study area only in post roman times, pedogenesis could act for 8000 – 12,000 years. the definition of the pedogenetic nature of the weathering features is based on macro and micromorphological observations, associated with physico-chemical analyses. the palynological analysis shows that the caranto level is characterized by a very low pollen content. the late holocene lagoonal deposits which cover the caranto palaeosol have dominant subtidal / intertidal mud flat and salt marsh facies, within a context of varying water salinity probably related to river inputs. the presence of a slightly pedogenized level developed in a salt marsh environment, indicates a hiatus in the deposition of the lagoonal sediments. two radiocarbon datings of the organic o horizons of this soil in two cores show that this discontinuity is of medieval age. furthermore, they provide a reliable chronostratigraphic support to the determination of the recent relative sea level rise. this latter has been estimated 2.3 m since 1055 – 954 cal bp to present day in porto marghera, enirisorse area, and 1.1 m since 640 – 592 cal bp to present day in porto marghera fusina, abibes area. riassunto nel corso di questa ricerca sono stati studiati dal punto di vista stratigrafico, paleopedologico e palinologico le carote provenienti da 4 sondaggi ubicati al margine interno del settore centrale della laguna di venezia, tra la foce del f. dese e porto marghera, per una profondità massima di 15 m dal piano campagna. in accordo col contesto stratigrafico generale già definito in numerosi studi precedenti, i depositi lagunari olocenici ricoprono qui, con spessore esiguo, una serie fluviale datata 21.000 – 18.000 bp. il record pollinico di questi sedimenti è caratterizzato da piante idrofile (typha, potamogeton, nymphaea ...), tipiche di ambienti palustri riferibili all’ultimo pleniglaciale e al tardiglaciale. inquadrando i depositi fluviali nell’ambito della pianura veneta centrale, si evince che il sistema sedimentario attivo nell’area di studio era quello tardopleistocenico del brenta (megafan di bassano), in aggradazione fino al tardiglaciale. al tetto dei depositi alluvionali è presente il livello alterato, sovraconsolidato, con screziature e noduli carbonatici, conosciuto nell’area lagunare con il nome di “caranto”. mediante uno studio paleopedologico, e comparando i risultati con le caratteristiche dei calcisol presenti sulle superfici distali del megafan di bassano in prossimità della laguna, è stato possibile confermare la natura pedogenetica delle figure di alterazione che lo contraddistinguono. il “caranto” è stato dunque interpretato come un suolo sepolto, che si è sviluppato sui depositi di esondazione del tratto distale del megafan di bassano. l’arco temporale per la sua formazione è compreso tra la cessazione dei processi fluviali, avvenuta successivamente a 14.500 bp e, probabilmente, prima dell’inizio dell’olocene, e l’ingressione lagunare. nell’area di studio quest’ultima è attribuibile al periodo post romano, e dunque l’intervallo complessivo durante il quale la pedogenesi ha potuto agire è di 8000 – 12.000 anni. l’analisi palinologica ha mostrato che nel “caranto” il contenuto in polline ha valori estremamente bassi, probabilmente a causa della distruzione dei granuli durante la pedogenesi. i depositi lagunari indagati, riferibili all’olocene recente, presentano prevalentemente facies di fondo lagunare / piana intertidale e di palude salmastra (barena / salt marsh), con evidenza di fluttuazioni nella salinità dell’acqua, probabilmente dovute all’alterno influsso dei fiumi che sfociavano in laguna. la presenza di un livello debolmente pedogenizzato in ambiente di palude salmastra, indica l’esistenza di una lacuna stratigrafica all’interno della serie lagunare indagata. due datazioni al radiocarbonio degli orizzonti organici di questo suolo in due diverse località, indicano che tale hiatus ricade in età medievale. questi dati cronostratigrafici permettono, inoltre, di fornire una stima del recente innalzamento relativo del livello marino, pari a 2.3 m da 1055 – 954 cal bp al presente nell’area enirisorse di porto marghera, e 1.1 m dal 640 – 592 cal bp al presente nell’area abibes di porto marghera fusina. key words: venice, last glacial maximum, late glacial, palaeosol, palynology, alluvial plain, lagoon. parole chiave: venezia, last glacial maximum, tardiglaciale, paleosuolo, palinologia, pianura alluvionale, laguna. il quaternario italian journal of quaternary sciences 1166(1bis), 2003, 193-210 194 p. mozzi et al. 11.. iinnttrroodduuccttiioonn the lagoon-and-barrier sedimentary system of the lagoon of venice (fig. 1) is the result of a long-term history of delicate equilibrium between sea and land, that is, between coastal and fluvial processes. during the holocene, the sea level has been continuously rising, as a result of the combined effect of the post glacial eustatic sea level rise and local land subsidence. meanwhile, the piave and brenta rivers have been delivering large volumes of sediments to the adriatic sea. these materials, due to redistribution along the coast, have been providing the sands for the upbuilding of the barrier islands. on the other hand, these large alpine rivers repeatedly had their mouths within the lagoon itself, together with smaller rivers such as the musone, marzenego, dese and sile. in fig. 1a, it is possible to perceive how a further southwestern expansion of the piave sedimentary system, in connection with the sile system, would imply the infilling of the northern lagoon, as much as a progradation of the brenta system would bring about a forced regression in the southern lagoon. the only area in which there has been no important fluvial activity is in the central lagoon, where the distal fringes of the late pleistocene bassano megafan and nervesa megafan pro parte, reach the lagoon shores. in the underground, these late pleistocene continental deposits represent the bed on which the lagoonand-barrier sediments lie (fig. 1b). rivers freely choose their way to the lagoon just until the beginning of the second millenium a.d., when human control on the hydrographic network became progressively stricter. in fact, rivers brought about a lowering of the salinity near their mouths, because of the mixing of fluvial fresh-water with salty sea water. they also enhanced sedimentation, as they delivered alluvial sediments into the lagoon. both these tendencies were regarded as negative, and strongly contrasted by the venetians, for both sanitary (prevention of malaria) and economic (navigation in the lagoon) reasons. between the 11th and fig. 1a geomorphological sketch of the central veneto plain (modified from bondesan et al., 2002). 1. nervesa megafan (late pleistocene, holocene); 2. montebelluna megafan (late pleistocene); 3. bassano megafan (late pleistocene); 4. brenta alluvial plain (holocene); 5. monticano, cevada and meschio fans (holocene); 6. livenza alluvial plain (holocene); 7. sile, dese and zero alluvial plain (holocene); 8. musone alluvial plain (holocene); 9. piedmont fans (holocene); 10. littoral sandy deposits (holocene); 11. moraines (late pleistocene); 12. fluvial erosive scarps; 13. hills and mountains; 14. natural (a) and artificial (b) hydrography; 15. core location; 16. location of the geological cross section of fig. 1b. fig. 1b geological cross section (modified from broglio et al., 1987). 1. alluvial deposits of the bassano megafan (late pleistocene); 2. lagoonal deposits (holocene); 3. littoral deposits (holocene). a) b) 17th century a.d., the main rivers were artificially driven out of the lagoon by the venice republic, and only the minor watercourses were let in. in order to investigate the complex relations between the alluvial and lagoon sedimentary systems during the upper pleistocene and holocene, the inner shores of the central lagoon of venice, between the mouth of the dese river and porto marghera, have been chosen as a study area. particular attention has been devoted to the firm, mottled horizon locally known as caranto, widespread in the underground of the central lagoon, with the aim of understanding its genesis and evaluating its stratigraphic importance. 22.. tthhee ggeeoollooggiiccaall ffrraammeewwoorrkk the holocene lagoon-and-barrier sedimentary complex of the lagoon of venice started forming most probably around 7000 6000 bp (bortolami et al., 1977); the oldest radiocarbon datings of organic materials at the base of the lagoonal deposits are 7210±40 bp (depth of ca. 4.00 m below mean sea level) in the island of s. erasmo (schiozzi & brambati, 2000), 5090±100 bp (depth of 5.95 m below mean sea level) in the northern lagoon (serandrei barbero et al., 2001), 4670±70 bp in the underground of piazza s. marco, venice (depth of 5.80 m below mean sea level) (serandrei barbero et al., 2001). in general, in the central lagoon the deposits have an average thickness of around 5 m, progressively thinning towards the mainland (fig. 1b), but the scours of the tidal channels can be more than 10 m deep (alberotanza et al., 1977; mcclennen et al., 1997). in the underground of the city of venice, the lagoonal deposits, consisting of both silty clay sediments and sandy infillings of tidal channels, have a thickness of between 2 and 6 m. the sandy littoral deposits of the barrier islands, which separate the lagoon of venice from the adriatic sea, reach a maximum thickness of ca. 15 m (gatto, 1980; tosi, 1994). the accomodation space of the lagoon-and-barrier deposits has been provided by the coupled post glacial eustatic sea level rise and local land subsidence, that together constitute the relative sea level r ise. considering the last 6000 years, the sea level changes derived from coral dating in tahiti (bard et al., 1996) and speleothemes dating in the thyrrhenian sea (alessio et al., 1997) are consistent in indicating an eustatic sea level rise between 2 and 3 m. these trends, based on a reliable record for the last 12,000 years (antonioli & silenzi, 1998), may be taken as an indication also for the northern adriatic sea. the average subsidence rate in the lagoon of venice during the holocene has been estimated to be ca. 1.3 mm/year (bortolami et al., 1977; bortolami et al., 1984; serandrei barbero et al., 1997, serandrei barbero et al., 2001). altogether, this would suggest a theoretical relative sea level rise for the lagoon of venice of ca. 10 m during the last 6000 years (8 m due to land subsidence and 2 m to eustatic sea rise). available levelling measurements for the 1908–1930 period give a much lower subsidence rate of about 0.5 mm/year in the lagoon of venice (gatto & carbognin, 1981; carbognin et al., 1984; carbognin & tosi, 2003). these measurements were carried out before the peak of man-induced subsidence, related to over-pumping of underground water for industrial use in porto marghera during the mid20th century, and are thus indicative of the natural trend. based on this latter subsidence rate, the theoretical relative sea level rise for the lagoon of venice during the last 6000 years, before human impact, would only be ca. 5 m (3 m due to land subsidence and 2 m to eustatic sea rise). for comparison, we recall that the relative sea level rise since 6000 195stratigraphy, palaeopedology and palynology of late pleistocene ... bp has been estimated to be about 4 m in the lagoon of caorle, 30 km to the east of the lagoon of venice, and 8 9 m in the lagoon of marano, 15 km farther east (galassi & marocco, 1999). these differences may be due to different rates of land subsidence in different locations and time intervals. the lagoon-and-barrier sediments lie on top of late pleistocene alluvium (fig. 1b). in venice, the overall thickness of the fluvial deposits posterior to the last interglacial (marine isotopic stage 5e) is about 60 m (mullenders et al., 1996; kent et al., 2002). the topmost, radiocarbon dated, peat levels indicate that fluvial sedimentation was still active in the lagoon area during the last glacial maximum (bortolami, et al., 1977; tosi, 1994; serandrei barbero et. al., 2001); the latter is here intended as the period extended from about 22,000 to 15,000 bp, within the marine isotopic stage 2, during which the last maximum expansion of ice sheets and mountain glaciers took place in the northern emisphere (crowley & north, 1991, p. 47; orombelli & ravazzi, 1996). in the central lagoon these deposits mainly belong to the pleistocene brenta sedimentary system, which formed a megafan with the apex at the mouth of the brenta valley near bassano del grappa, elongated in a se direction (bassano megafan, fig. 1a) (mozzi, 1995; 1998; bondesan et al., 2002). the aggradation of the distal portions of this megafan was continuous until ca. 14,500 bp, after which the deactivation of the distributary system took place, due to fan-head trenching in the piedmont sector. this probably happened in response to the deglaciation of the alpine area, a crucial environmental change which occurred at the pleistocene – holocene transition. in any case, the presence of mesolithic (sauveterrian) sites at the surface in the distal bassano megafan, near the lagoon shores (broglio et al., 1987), indicates that sedimentation had already stopped by the early holocene. in the lagoon and in the mainland, these late pleistocene fluvial sediments consist of scarcely interconnected, few-metresthick, sandy channel deposits embedded in laminated, silty clay overbank deposits, with common, few-centimetres-thick peaty levels with lateral extension up to a few kilometres (favero et al., 1973; serandrei barbero et. al., 2001; iliceto et al., 2001; bondesan et al., 2002; bondesan & mozzi, 2002). at the top of the continental series is a compacted, mottled, 1 – 3 m thick level, with common millimetric to centimetric carbonatic nodules. gatto & previatello (1974) called this level a palaeosol, but they did not support this statement with any analytical or morphological assessment. it is regarded as rather continuous in the underground of the central lagoon, mantling the slightly undulated, gently southwards dipping unconformity surface positioned between the late pleistocene continental series and the overlying, mid-holocene barrier-andlagoon deposits (gatto, 1980). it is locally known as caranto, a word which was introduced in the scientific literature by the early geotechnical studies concerning the underground of venice (matteotti, 1962); the foundations of the city of venice rest on wood bearing piles which are driven in the resistant caranto. in fact, caranto is a word in venetian dialect with which peasants in the mainland traditionally indicate hard, cemented horizons, often forming few centimetres thick crusts, outcropping in the fields during tillage. soils with such horizons are 196 the typical calcisols widespread in the venetian plain, having late pleistocene, fine silty alluvial deposits as parent material (giandon et al., 2001). much palynological research has been carried out on the quaternary deposits of the lagoon of venice (bertolani marchetti, 1967; horowitz, 1967; paganelli, 1967; buurman, 1970; bandini mazzanti et al., 1974; calderoni et al., 2000). these studies evidence the occurrence of a continental environment during the glacial period, characterized by pine forests, particularly constituted by pinus sylvestris or p.mugo, and other microthermic plants. in the holocene, the area was dominated by mixed oak woods. the withdrawal of the arboreal plant pollen and the appearance of grains of hygro-hydrophytes record the development of wet environments. pollen grains which may be referred to a typical lagoon flora have been detected in most surface levels. 33.. mmeetthhooddss during this investigation the sedimentary series have been cored continuously to depths ranging between 5 and 15 m, in four different locations on the inner shores of the lagoon (fig. 1a): core pm 1, punta montiron, at the mouth of the dese river, depth 0 15 m; er 32, porto marghera, enirisorse area, depth 0 8 m; vecon 6, porto marghera, vecon area, depth 0 10 m; ab 6, porto marghera fusina, abibes area, depth 0 5 m. the deposits have been described in order to recognize the sedimentary and pedological features. 14c datings have been carried out by g. calderoni of the university of rome “la sapienza” (bondesan et al., 2002; bondesan & mozzi, 2002). radiocarbon dates have been calibrated with the calibration program calib rev 4.3, based on stuiver & reimer, 1993 (probability distribution, 1 sigma). palynological and palaeopedological analyses have been carried out just on cores pm 1, vecon 6 and ab 6, in the interval centred on the main unconformity between the continental and lagoon deposits. the sediment samples used for chemical and physical analyses have been air-dried and crushed to pass through a 2 mm sieve. standard laboratory methods have been carried out on the fraction <2mm, and included particle size distribution (clay, silt and sand content) by pipette method, organic carbon content according to walkey and black method, and ph (1:2.5 soil water ratio). cation exchange capacity (cec) and total acidity have been determined by titration after extraction with triethanolamine and bacl2 buffered at ph 8.2. total carbonates have been determined by gas-volumetric method using dietrich-fruehling calcimeter. micromorphology has been carried out on selected undisturbed samples, impregnated with resin and cut to obtain thin sections ca. 30 µm thick. description of thin sections has been carried out following bullock et al., 1985. for palynological analyses, the available sediment samples have been treated with cold hcl and hf, hot hcl and na-hexametaphosphate, sieved (250 µm), treated with hot naoh, stored in a water/glycerol solution 50% v/v. pollen percentages are calculated on the total of pollen grains and spores. 44.. ccoorreess ssttrraattiiggrraapphhyy aanndd ppaallaaeeooppeeddoollooggyy ccoorree ppmm 11 stratigraphy between 15.00 m and 12.60 m two main sand bodies, with erosive lower boundaries, are present (fig. 2). both show fining upward sequences, the lower one (14.90 ÷ 14.50 m) from medium sand to fine sand, the upper one (13.80 ÷ 12.60 m) from fine sand to sandy silt. between the two is a set of thinly laminated silt and silty sand, with a 15-cm-thick layer of silty clay at the bottom. on top of the upper sandy layer is a 10-cm-thick layer of peat, radiocarbon dated 20,630±240 bp (rome1188; bondesan et al., 2002), followed by 65 cm of silty clay which grades upwards to sandy silt. above lie a set of laminated alternances of silt and very fine sand, capped by 20 cm of silty clay. between 10.65 and 10.55 m there is another peat level, dated 18,720±200 bp (rome-1187; bondesan et al., 2002), 22,630 – 21,810 cal bp. the peat is covered by 2.25 m of clay silt, with evident millimetric planar bedding, containing common remnants of canes. three peaty layers are present within this sequence: the upper, and thicker one, at a depth of 8.55 ÷ 8.45 m, has an age of 18,200±190 bp (rome-1186; bondesan et al., 2002), 22,010 – 21,130 cal bp; these peat layers, as the others present in the core, show abrupt upper boundaries, while the lower boundaries are transitional in 2 4 cm. on top lie two thin sandy layers, separated by a clay silty loam interval between 7.80 and 7.50; the lower one shows positive grading from fine sand to very fine silty sand, the upper one consist of silty fine sand. the stratigraphic sequence is interrupted at the depth of 7.00 m, as the core has been damaged during drilling operations, and starts again at 6.00 m. between 6.00 and 4.50 m, the sediment is mainly silty; above 5.30 m, this interval is characterized by a firm consistence (pocket penetrometer test on the core give values of 3.50 kg/cm2), a massive structure, the presence of many hard carbonatic nodules several millimetres large, and abundant greyish and yellowish mottles. between 4.50 and 4.00 m is an organic rich silty loam, followed by thinly laminated, centimetric and decimetric alternances of fine sand, with varying percentages of silt and clay, and silty loam. many broken shells are present in the 4.00 – 2.30 m interval. the top 1.5 m are anthropogenic, and consist of urban garbage, as the borehole is located in an abandoned waste. see also tab.1 for details. textural and pedological analyses the uppermost samples (pm 1/1 to 5) are sandy, though in varying percentages, while the lower ones are more silty (fig. 3). all the samples examined show neutral to subalkaline reaction, and low carbonate percentage in the upper layers (samples pm 1/1 to 4); carbonate tends to disappear in the intermediate levels (samples pm 1/5-6-7), and to increase at the bottom. cation exchange capacity (cec) is medium to low, and decreases with depth; organic matter presents variable contents (range 1.5 – 6.5%) at the surface, decreasing with depth. micromorphology thin section examination of selected samples from p. mozzi et al. 197stratigraphy, palaeopedology and palynology of late pleistocene ... fig. 2 stratigraphic logs (see also tables 1, 2 and 3 for facies description and interpretation). 1. c: clay, z: silt, s: sand, g: gravel; 2. sand, silty sand; 3. silt, sandy silt, clay silt; 4. clay, silty clay; 5. organic loam; 6. peat; 7. anthropic deposits; 8. shells; 9. plant remains (leaves, canes, wood, rootlets); 10. carbonatic nodules; 11. buried soil, with horizons; 12. 14c date; 13. sample; 14. core gap; 15. tentative correlation of the top of the medieval organic horizons; 16. tentative correlation of the top of the caranto palaeosol. 198 this core indicates these prominent features. sample pm 1/7 presents a close porphyric microstructure, with high coarse/fine (c/f) ratio and few interconnected pores. blackish-brown undifferentiated organic components (undecomposed tissue fragments) are scarce. the coarse fraction consists of medium and fine sand, and coarse silt. quartz grains dominate, followed by mica flakes. the groundmass is greyish and the birefringence in the fine fraction results from small mica flakes and from randomly distributed clay domains. no calcitic features have been observed. the sample beneath (pm 1/8) is a yellowish-brown clayey-silt with greyish mottles. the microstructure is laminated, with graded subhorizontal laminae; coarser material is found at the bottom, and is constituted by fine quartz grains in a calcareous, silty groundmass. in this calcareous silt, carbonate nodules and semi-continuous crusts form in the bottom part of the layer. the samples underneath (pm 1/9, pm 1/10) present finer texture with thin laminations, alternatively oxidized (silty) and reduced (sandy), in a clayey-calcareous matrix; the thinner laminations tend to aggregate in calcareous nodules, similar to those of the above described horizon. ccoorree eerr 3322 stratigraphy between 8 and 6 m, the series is characterized by centimetric to decimetric alternances of fine sand and silt (fig. 2). the thicker sandy layer in this interval, between 7.70 and 7.40 m, is coarser (medium sand) and better sorted. from 6.00 to 4.60 m the sediment is a silty clay loam, firm, with up to 50% greyish (5y 6/1) and yellowish (2.5y 6/8) mottles, 2 – 10 mm large; between 5.45 and 4.60 m, there are up to 25% hard and soft caco3 nodules, 2 – 4 mm large. above there are 10 cm of grey (10y 5/1) silty clay, with many cuticles of canes, passing gradually (in 3 cm) to a dark grey (5y 5/2) peat (4.50 ÷ 4.05 m), dated 1095±55 bp (rome-1206), 1055 – 954 cal bp. this organic layer is covered by a 15-cm thick layer of very fine sand (abrupt boundary), which in turn lies under 30 cm of medium sand, well sorted, containing many cardium shells; the boundary between the two is erosive. on top there are more than 3-m thick anthropogenic deposits (landfill of the industrial area of porto marghera). ccoorree vveeccoonn 66 stratigraphy the lowermost sediments in the core (fig. 2), between 10.00 and 9.70 m, consist of 1 – 3 mm thick alternances of fine sand and silt, overlain by 1 m of laminated clay silt. above, between 8.70 and 6.90 m, is a rather thick layer of silty fine sand, which grades upward to sandy silt (6.90 ÷ 6.20 m), and is covered, through an abrupt boundary, by silt (6.20 ÷ 5.90 m). between 5.90 and 3.45 m the series is rather homogeneous from a grain size point of view, spanning from silty clay to silty loam, but the general characteristics differ much in the various levels. between 5.20 and 3.55 the sediments are firm (up to 4.5 kg/cm2 with the pocket penetromer), massive, stained by many yellowish and greyish mottles, with up to 7% hard caco3 nodules. underneath (5.90 ÷ 5.20 m), the sediments are grey and less firm; the same applies to the 3.55 ÷ 3.45 m interval, which in addition contains common millimetric plant remains p. mozzi et al. fig. 3 pedological analyses of core pm 1 (wood, cuticles). between 3.45 and 2.80 m the silty sand sediments contain many, partly decomposed, wood fragments and much dispersed organic matter, the latter showing a peak in the top 10 cm. the 2.80 ÷ 2.40 m layer consists of laminated silty clay. the topmost deposits are anthropogenic (landfill of the industrial area of porto marghera). see also tab. 2 for details. texture and pedological analyses the analysed portion of the core is characterized by marked variations (fig. 4). the upper sample (vecon 6/1) is a subalkaline silty clay; carbonate and organic matter contents are moderately high, and cec is moderate. underneath there are two coarser levels (samples vecon 6/2, 6/3), loamy to loamy sand, decarbonated and acid, with high organic matter content and cec. further underneath (sample vecon 6/4) a change occurs, with a marked decrease in sand content (<10%); in this subacid silty-clay level carbonates are absent, organic matter and cec are low. the samples beneath this one (vecon 6/5 to 6/12) present rather uniform characteristics. texture is clay silty, with sand contents ranging from 1% to 10%. reaction is overall subalkaline; carbonates are abundant and organic matter content is very low or absent, cec is low. the deepest sample (vecon 6/13), instead, is a subalkaline sandy loam, calcareous, with very low cec. micromorphology sample vecon 6/3 presents coarse texture with high porosity (>20%) determined by interconnected chambers and channels. the mineral fraction in the groundmass is greatly masked by abundant, reddish brown organic matter fragments (mostly roots and undecomposed tissue fragments). remnants of calcareous shells are frequent too. underneath, a layer (sample vecon 6/4) with fine texture, uniformely distributed throughout, occurs. the groundmass is prevalently silty-calcareous, with a few sand-size quartz relicts. in the top part of this layer organic fragments are still present, while in the bottom part these disappear; ferrugineous nodules and yellow mottles occur in a grey matrix. microstructure is apedal with very low porosity (total pores <5%); calcareous features are absent. the previously described layer shades off gradually in a set of fine silty, calcareous levels with a grey colour and pale yellow fine sand laminations. calcareous material in the matrix is arranged into cryptocrystalline nodules of septaria type (sample vecon 6/5, fig. 6e); some of these nodules are cut by thin fissures. at the bottom of these levels, coarser material (fine sand) forms discontinuous laminations with the finer one; the groundmass is greyish with yellowish mottles and fine fe-mn granulations, and the calcareous material is arranged in concretionary forms (sample vecon 6/6, fig. 6f), as above. ccoorree aabb 66 stratigraphy between 5.00 and 4.30 m the silty and silty clay loam contains many hard and soft carbonatic nodules, often in horizontal laminae (fig. 2); it is firm and with yellowish and greyish mottles. the overlying silty clay loam (4.30 ÷ 3.80 m) also contains few soft carbonatic 199stratigraphy, palaeopedology and palynology of late pleistocene ... fig. 4 pedological analyses of core vecon 6 nodules, but the matrix is not carbonatic. between 3.80 and 3.20 m there are centimetric alternances of silt, silty loam and loam, covered by a 40-cm thick layer of peat, the top 10 cm of which have been dated 585±50 bp (rome-1205), 640 – 592 cal bp. over the peat, between 2.80 and 2.30 m, is a clay to silty loam; partly decomposed plant remains (cuticles of canes) are commonly present in the lower 30 cm, while in the upper part some rootlets are present and the remaining organic matter is dispersed or in the form of carbonaceous flecks. see also tab. 3 for details. texture and pedological analyses the whole section is characterized by a relevant vertical variability, as evidenced by textural differences and by total carbonate and organic matter contents, ph and cec values (fig. 5). the upper sample (ab 6/1) is a fine clay silt with a neutral reaction, calcareous, with low cec and moderate organic matter content. beneath is a silty clay layer (sample ab 6/2), subacid, with medium cec and high organic matter content. the mineral fraction of the peaty layer underneath (sample ab6/3b) is a sandy loam; carbonate is absent, ph is acid, cec and % of organic matter are high. sample ab 6/4 is an acid loam, non calcareous, moderately active, with high organic matter content. the underlying samples (ab 6/5, 6/6, 6/8 and 6/7) are characterized by textures ranging from silty clayey to silty. the ph increases to subalkaline values and therefore carbonate is present with relevant concentrations (up to 40%); instead, organic matter is low (<1%), as well as cec. micromorphology sample ab 6/4 (fig. 6a) presents a moderately developed subangular blocky microstructure; total voids are 20%, with interconnected planes and channels; basic mineral components are rounded quartz grains; organic components are partly decomposed fragments of tissue, which contribute to the grey-blackish colour of the matrix. the fine fraction is fine silty with close porphyric speckled b-fabric and randomly distributed clay domains with a weak birefringence. the sample underneath (ab 6/5, fig. 6b) presents similar subangular blocky microstructure, but the soil matrix appears bleached (yellowish to greyish), and ferrugineous features are present in the form of impregnative nodules and dendritic segregations, frequently bordered by clay papules. textural pedofeatures are present in the form of fine and coarse laminations, with common fragments of terrestrial gasteropod shells. in sample ab 6/6 there are common caco3 crusts and nodules (fig. 6c). underneath, sample ab 6/8 (fig. 6d) shows apedal to very weakly developed subangular blocky microstructure, with total voids <10%; calcitic features predominate in the form of weakly laminated calcareous crusts and channel infillings. few shell fragments are present. the groundmass is rather uniform in all samples. the coarse fraction (>5 µm) consists of medium and fine sand, where quartz grains dominate, followed by mica flakes, ferrugineous segregations and organic fragments. 200 p. mozzi et al. fig. 5 pedological analyses of core ab 6 201stratigraphy, palaeopedology and palynology of late pleistocene ... fig. 6 thin sections of selected soil horizons: a) cg horizon in core ab6 (sample 4, cross polarized light xpl): speckled b-fabric, with traces of subvertical rootlets; b) 2bcg horizon in core ab 6 (sample 5, xpl): iron – manganese nodule with clay rim, in non calcareous, closed-porphyric matrix ; c) 2ckg1 horizon in core ab 6 (sample 6, plane polarized light ppl): laminated calcareous crusts; d) 2ckg2 horizon in core ab 6 (sample 8, xpl): laminae with caco3 nodules; e) 2ckg1 horizon in core vecon 6 (sample 5, xpl): septaria calcite nodule in compact matrix; f) 2ckg2 horizon in core vecon 6 (sample 6, ppl): dusty carbonatic nodules. 55.. ppaallyynnoollooggiiccaall aannaallyyssiiss ccoorree ppmm11 in this core (fig. 2, fig. 7), samples pm 1/16 and from 7 to 1 present an apf (absolute pollen frequency) ranging from 900 to 3,400 grains per gram. samples pm 1/15 8 proved palynologically quite sterile. in sample pm 1/16, the nap (herbaceous plant pollen) sharply prevails over the ap (arboreal and shrubby plant pollen). with regard to the ap, pinus pollen is the most abundant; a large part of the grains is attributable to pinus sylvestris l. or to pinus mugo turra. other microthermic species are picea, abies and betula. ephedra fragilis type is also present. elements of the oak mixed forest (such as quercus, corylus, carpinus) and hygrophilous trees are scarce. among the nap, cyperaceae dominate (37.7%), showing their highest percentage within the pm 1 core; other hygrophilous and hydrophilous plants (typha cf. latifolia, potamogeton, nymphaea) are present. gramineae are relatively abundant, followed by chenopodia-ceae and artemisia. samples pm 1/7 and pm 1/6 are characterized by very high percentages of chenopodiaceae grains, up to 47%. these noticeable values are ac-companied by significant plumbagina-ceae (cf. limonium) pollen percentages (7.8% and 6.3%). cyperaceae percentages drop. the ap are less numerous than in sample pm 1/16. samples pm 1/5 and pm 1/4 show a sharp increase of deciduous tree pollen, while pinus pollen has low percentages. quercus becomes the dominant genus among the ap, followed by corylus, carpinus betulus l. and other elements of the oak mixed forest; these plant curves show their maximum value in sample pm 1/4. fagus curve achieves a maximum in sample pm 1/5. alnus pollen is abundant, particularly in sample pm 1/5, where it is accompanied by salix. among the nap, chenopodiaceae percentages sharply fall and reach their lowest value (11%) at pm 1/4. plumbaginaceae curve follows the same trend as chenopodiaceae. cyperaceae and aquatic plants are scarce. in samples pm 1/3 and pm 1/2, the percentage of the oak mixed forest elements slowly decreases, as well as the alnus percentages. abies shows a rise in sample pm 1/2 (8.4%). among the nap, chenopodiaceae record firstly an increase and later a decrease; cyperaceae are increasingly represented. in sample pm 1/1, the ap present again an increased percentage. the oak mixed forest seems to be expanded, deciduous quercus and corylus being the best represented trees. castanea achieves its highest percentage. alnus reaches 8%. among the nap, chenopodiaceae are well represented, while cyperaceae have decreased, though their percentage remains significant. ccoorree vveeccoonn 66 the most ancient samples vecon 6/13 and vecon 6/12 present very low pollen content, especially sample vecon 6/13 (apf=100) (fig. 2, fig. 8). in sample vecon 6/12, most of the grains are referable to the nap, expecially to cichorioideae, gramineae and cyperaceae; sparganium/typha angustifolia is also present. among the ap, pinus pollen dominate; the grains are referable to some different species, among which p. sylvestris and p. mugo. samples from vecon 6/11 to vecon 6/5 result quite palynologically sterile. samples vecon 6/4, 6/3 and 6/1 are rich in grains, apf ranging from 2,300 to 16,600 grains per gram. on the contrary, sample vecon 6/2 present a low apf (200 grains per gram) and badly preserved grains. in the latter samples, ap percentage is low, suggesting a very scarce arboreal cover. however, the oak mixed forest plants are represented by different morphotypes, which are expecially numerous in sample vecon 6/1. pinus 202 p. mozzi et al. f ig . 7 p er ce nt ag e po lle n di ag ra m o bt ai ne d fr om c or e p m 1 pollen is always present in low percentages. alnus and salix, with the sporadic occurrence of populus, indicate the presence of wet environments, as well as cyperaceae among the nap. cyperaceae percentage increases upwards where aquatic plants, such as callitrichaceae and potamogeton, are present too. chenopodiaceae are very abundant throughout the section, with the exception of sample vecon 6/2. plumbaginaceae and chenopodiaceae indicate the occurrence of brackish environments. ccoorree aabb 66 only samples ab 6/1, 6/2 and 6/3b present a sufficiently high pollen concentration to allow an exhaustive pollen analyses, apf ranging from 600 to 21,100 grains per gram (fig. 2, fig. 9). samples ab 6/8, 6/7, 6/6, 6/5 and 6/4 proved almost sterile. the ap percentages are very low (7 25%). consequently, we can hypothesise that the arboreal cover was almost totally absent near the sampling site. the arboreal plant grains in the list may have been longdistance transported from mountain (i.e. picea, abies) and oak mixed forests (i.e. quercus, carpinus, corylus). among the nap, chenopodiaceae pollen is the most abundant (34 39.2%). the examined morphotypes are similar to those of the salicornieae, which grow on salty soils, as well as plumbaginaceae (cf. limonium) that are also present in the samples. the percentages of these last plants, which are generally underrepresented in the spectra (heim, 1975), validate the widespread of brackish habitats. cyperaceae, which indicate moist environments, are well represented. other records significant for water habitats (juncus, typha cf. latifolia, sparganium/typha angustifolia, callitrichaceae, potamogeton) have been found especially in the lowest sample. 66.. sseeddiimmeennttaarryy eennvviirroonnmmeennttss aanndd ffaacciieess the characteristics of the lowermost sediments in core pm 1, in the interval 15.00 ÷ 5.30 m, allow their interpretation as fluvial deposits. overbank fines are dominant; the only evident channel deposits are those of the graded sandy layer between 13.80 and 12.60 m, while the thinner sand bodies most probably represent crevasse splays. the peat on top of the channel body, dated 20,630±240 bp, marks the deactivation of the channel. the presence of several peaty layers within the floodplain sequences indicates the recurrence of events of diminished sedimentation in the flood basins and the formation of marshes with prevalent organic sedimentation. the radiocarbon dates show that they formed during the last glacial maximum. sediments with similar 203stratigraphy, palaeopedology and palynology of late pleistocene ... f ig . 8 p er ce nt ag e po lle n di ag ra m o bt ai ne d fr om c or e v ec on 6 facies are found in core er 32, between 8 and 6 m, and in core vecon 6, between 10 and 6 m, where a channel body is present between 8.70 and 6.90 m, covered by silty loam natural levee. all these deposits belong to the pleistocene brenta sedimentary system, which extends at the back of the central sector of the lagoon of venice (fig. 1); they represent the distal fringes of the bassano megafan, in aggradation unti l after 14,500 bp. geochronology is consistent with the palynological data. in fact, the sampled sediments in pm 1 and vecon 6 (samples pm 1/16, vecon 6/12), have low ap percentages, but relatively high values of pinus pollen, particularly pinus sylvestris / mugo pollen group; other plants from cold or cold-dry climate (picea, abies, betula, ephedra belonging to the e. fragilis pollen type) are also present. actually, in all the samples of the three cores, the ap percentages are generally low or very low, suggesting that the arboreal cover was always scarce, or almost totally absent, at the sampling sites. among the nap, gramineae and cyperaceae are abundant; chenopodiaceae show significant percentages. the results suggest the presence of woodlands characterized by picea, pinus sylvestris and/or p. mugo and betula, trees that today grow in mountain areas; the quercetum was poorly widespread. lacustrine or marsh habitats were frequent; xerophilous plants occurred on dry, perhaps sandy, substrates. the spectra recorded are in agreement with those of previous palynological studies carried out on pleistocene or preboreal sediments from veneto, po plain and from the central adriatic sea (bertolani marchetti, 1967; paganelli, 1967; paganelli & miola, 1991; accorsi et al., 1996; bertoldi, 1996; lowe et al., 1996; paganelli, 1996a; 1996b). between 5.30 and 4.50 m in pm 1, 6.00 and 4.60 m in er 32, 5.90 and 3.55 m in vecon 6, 5.0 and 3.80 m in ab 6 there is evidence of post depositional weathering of the alluvial deposits. the most striking features are the abundant caco3 nodules and mottling, evident both to macroand microscopic observation, and the high matrix consolidation, measured on some cores with the pocket penetrometer (tab. 1, 2, 3). all these elements are indicative of the caranto level, as described in previous l i terature (gatto & previatello, 1974; alberotanza et al., 1977; tosi, 1994; serandrei barbero et al., 2001). nevertheless, it is to be noted that also the calcic horizons of the silty clay soils in the mainland, developed on the late pleistocene alluvial plain in the distal reaches of the bassano megafan, at the immediate proximity of the lagoon, have similar characteristics (giandon et al., 2001); regarding the overconsolidation, the b and c horizons of these latter soils are commonly as firm as the caranto, with mean values of 3.0 4.0 kg/cm2 to the pocket penetrometer. the different horizons of the caranto level observed in the cores (fig. 2; tab. 1, 2, 3) are thus, most likely, pedogenic calcic b and c horizons as well, having the silty clay calcareous sediments of the top of the underlying fluvial sequence as the parent material. the redistribution of carbonates along the profile, due to leaching in the upper horizons and reprecipitation in the lower ones, was associated with alternating oxidizing and reducing conditions, as evidenced by the abundant mottling. the non calcareous 2bcg horizon in core ab 6, between 3.80 and 4.00, probably represent the upper horizon of the original soil profile, depleted of caco3 by vertical leaching. 204 p. mozzi et al. f ig . 9 p er ce nt ag e po lle n di ag ra m o bt ai ne d fr om c or e a b 6 205stratigraphy, palaeopedology and palynology of late pleistocene ... dd eepp tthh ss aamm ppll ee ttee xxtt uurr ee ss ttrruu cctt uurr ee mm uunn ssee llll mm oott ttllee ss cc aacc oo 33 cc aacc oo 33 oo .. mm .. pp llaa nntt rree mm aaii nnss ss hhee llllss lloo ww eerr ffaa ccii eess m # (u s d a ) (a nd p .p . t es t) cc ooll oouu rr % , c ol or , d im en si on s nn oodd uull eess % % bboo uunn ddaa rryy 1. 50 –1 .8 0 1 lo am y la m in at ed , s of t 5y 4/ 1 n o n o 8 15 n o n o a br up t la go on sa nd (0 .5 0 kg /c m 2 ) 1. 80 -1 .9 0 n o sa m pl e lo am y sa nd m as si ve , s of t 5y 4/ 1 n o n o n o n o a br up t la go on lo am (0 .5 0 kg /c m 2 ) 1. 90 -2 .3 0 2 s an dy la m in at ed , s of t 5y 4/ 1 n o n o 5 65 n o n o a br up t la go on (0 .5 0 kg /c m 2) 2. 30 -2 .7 0 3 s ilt y lo am la m in at ed , s of t 5y 4/ 1 n o n o 5 19 n o m an y, n ot la go on (0 .5 0 kg /c m 2 ) br ok en ob se rv ed 2. 70 -3 .3 0 c or e ga p 3. 30 -3 .5 0 n o sa m pl e s ilt y lo am m as si ve , s of t 5y 5/ 1 15 % , 5 y 5/ 3, 5 m m n o n o c om m on tr an si tio na l, la go on (0 .3 0 kg /c m 2 ) 2c m 3. 50 -3 .7 0 4 s an dy lo am m as si ve , s of t 5y 5/ 1 n o n o 10 26 n o c om m on a br up t la go on (0 .3 0 kg /c m 2 ) 3. 70 -3 .8 0 n o sa m pl e lo am y sa nd m as si ve , s of t 5y 5/ 1 n o n o n o m an y a br up t la go on (0 .3 0 kg /c m 2 ) 3. 80 -4 .0 0 5 lo am la m in at ed , s of t 5y 5/ 1 n o n o 0 32 n o c om m on a br up t la go on (0 .3 0 kg /c m 2 ) 4. 00 -4 .5 0 6, 7 s ilt y cl ay m as si ve , s of t n 5 n o n o 0, 0 27 , m an y ca rb on ac eo us n o tr an si tio na l, s al t m ar sh , a lo am ; l oa m (0 .5 0 kg /c m 2 ) fle ck s 4c m so il ho riz on 4. 50 -4 .7 0 8 s ilt y lo am m as si ve , f irm 5y 6/ 2 25 % , 5 y 6/ 1, 2 m m h ar d, 12 s om e ro ot le ts , n o tr an si tio na l 2b c k so il (1 .7 5 kg /c m 2 ) 10 % , 5 y 6/ 4, 2 m m 25 m m , 5 % φ =1 m m 3c m ho riz on 4. 70 -4 .8 5 9 s ilt y lo am m as si ve , v er y fir m 2. 5y 6/ 3 20 % , 5 y 6/ 1, 3 m m h ar d, 21 n o n o a br up t 2c k1 s oi l (3 .5 0 kg /c m 2 ) 15 % , 5 y 5/ 6, 3 m m 3 m m , 2 % ho riz on 4. 85 -5 .3 0 10 s ilt y lo am m as si ve , v er y fir m 2. 5y 6/ 4 10 % , n 6, 5 m m h ar d, 30 n o n o tr an si tio na l, 2c k2 s oi l (3 .5 0 kg /c m 2 ) 10 % , 2 .5 y 5/ 6, 3 m m 27 m m , 8 % 5c m ho riz on 5. 30 -5 .5 0 11 s ilt y lo am m as si ve , v er y fir m 5y 7/ 2 20 % , 5 y 6/ 4, 4 m m n o 38 n o n o tr an si tio na l, 2c s oi l (3 .5 0 kg /c m 2 ) 8c m ho riz on 5. 50 -6 .0 0 15 s ilt y lo am la m in at ed , f irm n 6 n o n o 33 n o n o n ot o bs er ve d fl uv ia l, (1 .2 0 kg /c m 2 ) ov er ba nk 6. 00 -7 .0 0 c or e ga p 7. 00 -7 .5 0 n o sa m pl e s an dy lo am la m in at ed , f irm n 6 n o n o n o n o a br up t fl uv ia l, (1 .7 5 kg /c m 2 ) cr ev as se s pl ay 7. 50 -7 .8 0 16 s ilt y cl ay la m in at ed , f irm 5y 7/ 1 n o n o 33 n o n o a br up t fl uv ia l, lo am (1 .7 5 kg /c m 2 ) ov er ba nk 7. 80 -8 .3 0 n o sa m pl e s an dy lo am fi ni ng u pw ar d, s of t 5y 7/ 1 n o n o n o n o a br up t fl uv ia l, (0 .7 5 kg /c m 2 ) cr ev as se s pl ay t ab . 1 t he m ai n ch ar ac te ris tic s of th e sa m pl ed in te rv al in c or e p m 1 . 206 p. mozzi et al. dd eepp tthh ss aamm ppll ee ttee xxtt uurr ee ss ttrruu cctt uurr ee mm uunn ssee llll mm oott ttllee ss cc aacc oo 33 cc aacc oo 33 oo .. mm .. pp llaa nntt rree mm aaii nnss ss hhee llllss lloo ww eerr ffaa ccii eess m # (u s d a ) (a nd p .p . t es t) cc ooll oouu rr % , c ol or , d im en si on s nn oodd uull eess % % bboo uunn ddaa rryy 2. 40 –2 .8 0 1 s ilt y cl ay la m in at ed , s of t 5y 5/ 1 n o n o 15 24 n o n o a br up t la go on (0 .7 5 kg /c m 2 ) 2. 80 -2 .9 0 2 s an dy lo am m as si ve , s of t 5y 4/ 1 n o n o 0 64 n o n o a br up t s al t m ar sh , a (0 .7 5 kg /c m 2 ) so il ho riz on 2. 90 -3 .4 5 3 s an dy lo am m as si ve , s of t 5y 3/ 1 n o n o 0 60 m an y w oo d an d ca ne n o a br up t s al t m ar sh , (0 .7 5 kg /c m 2 ) fra gm en ts , 1 ÷3 m m a c s oi l h or iz . 3. 45 -3 .5 5 4 s ilt y cl ay m as si ve , f irm 5g 5/ 1 n o n o 0 17 c om m on w oo d an d ca ne n o tr an si tio na l, s al t m ar sh , (1 .2 5 kg /c m 2 ) fra gm en ts , 1 ÷3 m m 3c m c g so il ho riz . 3. 55 -4 .0 0 5 s ilt y lo am m as si ve , s of t 5y 6/ 1 15 % , 5 y 6/ 8, 4 m m c ac o 3, h ar d, 13 9 n o n o tr an si tio na l, 2c kg 1 so il (0 .7 5 kg /c m 2 ) 3m m , 7 % 3c m ho riz on 4. 00 -5 .2 0 6, 8, 7 s ilt y cl ay lo am m as si ve , v er y fir m 5y 7/ 1 30 % , 2 .5 y 6/ 8, 1 5m m c ac o 3, h ar d, 28 , 3 5, 2 9 n o n o tr an si tio na l, 2c kg 2 so il (4 .5 0 kg /c m 2 ) 20 % , 1 0g y 6/ 1, 2 0m m 3m m , 5 % 5c m ho riz on 5. 20 -5 .9 0 9, 10 s ilt y cl ay lo am m as si ve , v er y fir m n 6 30 % , n 7, 2 0m m n o 30 , 2 9 n o n o tr an si tio na l, 2c g so il (4 .5 0 kg /c m 2 ) 15 % , 5 y 5/ 6, 1 0 m m 10 cm ho riz on 5. 90 -6 .2 0 n o sa m pl e s ilt y lo am la m in at ed , v er y 10 y 6/ 1 n o n o n o n o a br up t fl uv ia l, e fir m (3 .2 5 kg /c m 2 ) na tu ra l l ev e 6. 20 -6 .9 0 11 ,1 2 s ilt y lo am la m in at ed , f irm 10 y 6/ 1 n o n o 32 ,3 0 n o n o a br up t fl uv ia l, (1 .7 5 kg /c m 2 ) na tu ra l l ev ee 6. 90 -8 .7 0 13 s an dy lo am la m in at ed , s of t 10 y 6/ 1 n o n o n o n o a br up t fl uv ia l, ch an ne l t ab . 2 t he m ai n ch ar ac te ris tic s of th e sa m pl ed in te rv al in c or e v ec on 6 . dd eepp tthh ss aamm ppll ee ttee xxtt uurr ee ss ttrruu cctt uurr ee mm uunn ssee llll mm oott ttllee ss cc aacc oo 33 cc aacc oo 33 oo .. mm .. pp llaa nntt rree mm aaii nnss ss hhee llllss lloo ww eerr ffaa ccii eess m # (u s d a ) (a nd p .p . t es t) cc ooll oouu rr % , c ol or , d im en si on s nn oodd uull eess % % bboo uunn ddaa rryy 2. 30 –2 .5 0 1 s ilt y lo am la m in at ed 10 y 5/ 1 n o n o 12 24 c om m on c ar bo na ce ou s n o a br up t s al t m ar sh fle ck s 2. 50 -2 .8 0 2 c la y lo am la m in at ed 10 g 4/ 1 n o n o 5 59 le av es o f c an es n o a br up t s al t m ar sh 2. 80 -3 .2 0 3b p ea t fi br ou s 10 y r 3/ 1 n o n o 0 21 3 p ea t n o tr an si tio na l, s al t m ar sh , o 3c m so il ho riz on 3. 20 -3 .8 0 4 lo am la m in at ed 5g y 4/ 1 n o n o 0 48 n o n o a br up t c g so il ho riz on 3. 80 -4 .0 0 5 s ilt y cl ay m as si ve , f irm 10 y 5/ 1 15 % , 5 y 6/ 8, 4 m m s of t, 3m m , 3 % 0 14 n o n o n ot o bs er ve d 2b c g so il lo am ho riz on 4. 00 -4 .3 0 6 s ilt y lo am m as si ve , f irm 2. 5y 6/ 2 25 % , 5 y 6/ 1, 3 m m h ar d an d so ft, 0 11 n o n o a br up t 2c kg 1 so il 3m m , 8 % ho riz on 4. 30 -5 .0 0 8, 7 s ilt , s ilt y cl ay lo am m as si ve , f irm 5y 6/ 1 30 % , 5 y 6/ 4, 5 m m h ar d, 5 m m , 4 % 25 ,4 3 17 ,8 n o n o n ot o bs er ve d 2c kg 2 so il ho riz on t ab . 3 t he m ai n ch ar ac te ris tic s of th e sa m pl ed in te rv al in c or e a b 6 . brackish environments, with episodes of varying salinity in the water and soils. this may be due to the alternating prevalence of sea water vs. fluvial fresh-water of rivers flowing into the lagoon. from a palynological point of view, the results are consistent with those of the previous literature. particularly, the presence of sterile layers, which separate a lower group of sediments, attributed to a continental, fluvial environment, from an upper group with evident brackish characteristics, was observed by bertolani marchetti (1967). the sediments that lie unconformably on top of the caranto (above the dotted line n. 16 in fig. 2) were deposited in a paralic context, typical of the landward sector of the lagoon. here, tidal processes interacted with fluvial activity, in a metastable equilibrium which could rapidly change in space and time. subtidal flats, intertidal flats and tidal channels could alternate laterally (in space) or vertically (in the stratigraphy) with vegetated salt marshes and small deltas, the latter related to the delivery of fluvial sediments into the lagoon. such geomorphic and sedimentary model applies well to the complex stratigraphic record of the studied cores (fig. 2; tab. 1, 2, 3). considering the whole ne – sw transect of fig. 2, the lowermost lagoonal deposits are found at depths comprised between 1 and 2.5 m below mean sea level. in the observed lagoonal deposits there is a prevalence of subtidal / intertidal mud flat facies, with salt marshes (tab. 1, 2, 3); only in core er 32, at the depth of ca. 1.50 m below mean sea level, there is evidence of a sandy tidal channel (fig. 2). it is, furthermore, possible to recognize two main sedimentary events (separated by the dash line n. 15 in fig. 2). the sediments of the first one are altogether less than 1 m thick, and are capped by the organic horizons radiocarbon dated to the middle ages. these latter are pedogenetic a and o horizons, underlain by gley ac and c horizons, which constitute a weakly developed, subacid soil. the activity of soil forming processes implies the existence of a subaerial topographic surface, while the presence of near surface gley horizons indicates a high underground water table. this is consistent with the salt marsh environment shown by the pollen record. in fact, salt marshes lie immediately above the average high tide level, and are only seldom submerged during maximum high tides (albani et al., 1984; castiglioni, 1986). in vecon 6, where the a and ac horizons are well developed, the micropedological analysis of the underlying cg horizon allowed for the recognition of yellowish mottles and ferruginous nodules, which are indicative of occasional conditions above the water table. the greyish – greenish colour of the a horizon in pm 1 indicates a badly drained situation with permanent reducing conditions, and the same applies to the cg horizons under the o horizons in core er 32 and ab 6. the lateral variations from a horizons, with partly mineralized organic matter, and o horizons, made of indecomposed organic matter, can be interpreted as a hydro-pedosequence, where the former occupy the higher, relatively better drained topographic positions, and the latter the depressions. the average high tide level most probably used to cut the soil profile in cores er 32 and ab 6 at the lower boundary of the o horizons. therefore, the 1055 – 954 cal bp average high tide level is now ca. 2 m below the present mean sea level (core er 32), while the one of 640 in order to estimate the time-length required for the development of these soil horizons, some considerations can be made. the deactivation of the bassano megafan took place after 14,500 bp, probably before the onset of the holocene, when the sea level was still more than 50 m below the present day one. from that moment onwards, sedimentation in the bassano megafan stopped, and soil forming processes became dominant. the early and middle holocene mild environmental situation, with dense forest cover, involved optimal conditions for soil formation. at the same time, the continuous relative sea level rise brought about a progressive submersion of the alluvial plain that occupied the northern adriatic basin during the last glacial sea lowstand. by 6000 bp, the lagoon of venice had already started forming, which implies that the more distal fringes of the bassano megafan, were submerged and pedogenesis had already ceased. all this allows a time slice of 4000 to 8000 years for soil formation on this stretch of alluvial plain. the study area, in a more landward position, was still emerging at that time, and most probably all along the middle to late holocene. in our research, no evidence has been gathered about when the study area evolved to paralic, brackish conditions. an indication is provided by a recent investigation carried out in the ca’ tron area, on the northern lagoon shores about 15 km to the east of the study area, nearby the old mouth of the sile river in the lagoon. here, the maximum transgression on the late pleistocene alluvial plain has been dated to post roman times (bondesan & mozzi, 2002). if also in the study area the first lagoonal deposits were post roman, this would allow some other 4000 years to pedogenesis. in this framework, the studied caranto palaeosol may have formed in 8000 to 12,000 years. the palynological data clearly show that the apf falls to very low values in these weathered horizons. the drastic decrease of apf is, here, probably due to the alternating oxidative-reductive conditions and leaching during the soil formation. indeed, oxidation and subsequent wetting and drying cause damage of the exine (horowitz, 1992). in the samples collected in the layers above the caranto, a decrease of the microthermic elements and an increase of the deciduous broadleaf trees is recorded. this trend may be considered an index of climatic improvement. quercetum s.l. is well represented and quercus appears to be the leader tree; it reaches the widest expansion in samples vecon 6/4-3 and pm 1/5-4. the significant percentages of hygrophilous and hydrophilous plants, particularly alnus, underline the presence of alluvial environments and the occurrence of water bodies. the consistency of these data with the literature about the holocene (bertolani marchetti, 1967; accorsi et al., 1989; 1996; bertoldi, 1996; lowe et al., 1996; paganelli, 1996a), indicate that the deposits formed in the late holocene. this is coherent with the probable post roman age of the whole sequence, and with the medieval ages of the radiocarbon dated organic horizons intercalated in the sediments (fig. 2). as regards the vegetation with edaphic determinism, among the nap the alternate prevalence of cyperaceae and plants of fresh water habitats (typha cf. latifolia, sparganium/typha angustifolia, potamogeton, callitrichaceae) and halophytes (chenopodiaceae and plumbaginaceae) attests the presence of 207stratigraphy, palaeopedology and palynology of late pleistocene ... – 592 cal bp is 0.8 m below mean sea level (core ab 6). taking the 0.3 m a.s.l. high tide average height of the present day lagoon of venice (albani et al., 1984; castiglioni, 1986) as a reference, the mean sea level was respectively 2.3 and 1.1 m below the present one. this is a consequence of the relative sea level rise during the last centuries, deriving from the sum of the following phenomena: eustatic sea level rise, natural subsidence, man induced subsidence (since the second half of the 20th century). the second event buried these weakly developed palaeosols in late medieval and modern times. on top are the artificial landfills related to the land reclamation at the lagoon fringes during the 20th century. 77.. ccoonncclluussiioonnss the study of the sedimentary, pedological and palinological features of the cores, has enabled to recognize the sequence of events occurred in the late quaternary at the landward margin of the central sector of the lagoon of venice. during the last glacial maximum, the deposition of fluvial sediments took place in the study area, mainly as overbank fines with only limited sandy channel bodies. these deposits belong to the pleistocene brenta sedimentary system, the bassano megafan, which corresponds to a large stretch of the central veneto plain between the alpine piedmont and the lagoon of venice. arboreal vegetation was scant, and mainly consisted of microthermic elements. after the deactivation of this megafan, probably at the pleistocene – holocene transition, sedimentation in the area stopped and soil forming processes became dominant, acting on the calcareous, silty clay parent material of fluvial origin, probably for 8000 – 12,000 years. processes of redistribution of carbonates along the soil profile led to the formation of calcic b and c horizons, characterized by the accumulation of caco3 in nodules and crusts; just in one core (ab 6), the b horizon depleted of the carbonates by vertical leaching, which is normally on top of the calcic horizons, has been preserved. alternating oxidizing and reducing conditions, related to the fluctuation of the underground watertable, brought about greyish and yellowish mottling, and alteration of the pollen grains originally present in the sediment. this palaeosol corresponds to the so-called caranto level auctorum. it is in physical continuity with the calcisols of the stretch of plain at the back of the lagoon, belonging to the bassano megafan, and have similar pedogenetic features. it represents a major uncomformity in the stratigraphy of the lagoon area. the first lagoonal deposits in the study area are, most probably, of post roman age. they lie directly on top of the caranto palaeosol at depths comprised between 1 and 3 m below mean sea level. pollen analysis shows that salt marshes with halophytes formed in the higher parts of the tidal flats, while other areas evolved into more open lagoon environments, probably with recurrent input of fluvial sediments and water. less than 1 m of sediments were deposited during a first sedimentary event. its upper boundary corresponds to an unconformity of low rank, indicated by the presence of a slightly pedogenized level which formed in medieval times. the radiocarbon dating of organic o horizons of this soil, developed in a salt marsh environment, provides a chronostratigraphic support to the determination of the recent relative sea level rise. this is estimated to have been 2.3 m since 1055 – 954 cal bp to present day in porto marghera, enirisorse area, and 1.1 m since 640 – 592 cal bp to present day in porto marghera fusina, abibes area. the sediments of the following, last sedimentary event, spanning since the middle ages to modern times, reach a maximum thickness of ca. 2 m. aacckknnoowwlleeddggmmeennttss this research has been carried out within the project of the italian ministry of research “the response of geomorphic processes to environmental change” (murst 1997). we are grateful to prof. g. calderoni for the 14c datings, and dr. s. citran for having allowed access to the cores. rreeffeerreenncceess accorsi c.a., bandini mazzanti m., forlani l., meneghel a., rigoni a., sorbini l., 1989 primi dati stratigrafici e palinologici sulla sequenza di bernascone (verona), datata alla base 18.870 ±300 b.p. inf. bot. ital., 2211, 240-245. accorsi c.a., bandini mazzanti m., mercuri a.m., rivalenti c., trevisan grandi g., 1996 holocene forest pollen vegetation of the po plain northern italy (emilia romagna data). allionia, 3344, 233-276. alberotanza l., serandrei barbero r. & favero v., 1977 i sedimenti olocenici della laguna di venezia (bacino settentrionale). boll. soc. geol. it., 9966, 243-269. albani a., favero v. & serandrei barbero r., 1984 apparati intertidali ai margini di canali lagunari. studio morfologico, micropaleontologico e sedimentologico. ist. veneto di scienze lett. ed arti. commissione di studio dei provvedimenti per la conservazione e difesa della laguna e della città di venezia, 99, 137-162. alessio m., allegri l., antonioli f., belluomini g., improta s., manfra & preite m., 1997 la curva di risalita del mare tirreno negli ultimi 43 ky ricavata da datazioni su speleotemi sommersi e dati archeologici. memorie descrittive del servizio geologico nazionale, 52. antonioli f. & silenzi s., 1998 rassegna dello stato dell’arte sulle ricerche delle variazioni del livello del mare relativo all’ultimo semiciclo climatico e sul concetto di stabilità tettonica. il quaternario, 1111(1), 5-18. bandini mazzanti m., bertolani marchetti d., soletti g.a., 1974 palinologia di un livello torboso a -60 m a porto marghera. mem. biogeogr. adriatica, 99 (1973-74), 119-122. bard e., hamelin b., arnold m., montaggioni l., cabioch g., faure g., & rougiere f., 1996 deglacial sealevel record from tahiti corals and the timing of global meltwater discharge. nature, 338822, 241-244. bertolani marchetti d., 1967 vicende climatiche e flori208 p. mozzi et al. stiche dell’ultimo glaciale e del postglaciale in sedimenti della laguna veneta. mem. biogeogr. adriatica, 77 (1966-67), 193-225. bertoldi r., 1996 pre-holocenic and holocenic palynological outlines of western padania. allionia, 3344, 137-147. bondesan a., calderoni g. & mozzi p., 2002 l’assetto geomorfologico della pianura veneta centro-orientale: stato delle conoscenze e nuovi dati. in: zunica m. & varotto m. (eds.) volume in memoria di g. brunetta. dipartimento di geografia, università di padova, padova. bondesan a. & mozzi p., 2002 aspetti geomorfologici della tenuta di ca’ tron. in: ghedini f., bondesan a. & busana s. (eds.) la tenuta di ca’ tron. ambiente e storia nella terra dei dogi. cierre edizioni, verona. bortolami g., fontes j.ch., markgraf v. & saliege j.f., 1977 land, sea and climate in the northern adriatic region during late pleistocene and holocene. palaeogeography, palaeoclimatology, palaeoecology, 2211, 139-156. bortolami g.l., carbognin l. & gatto p., 1984 the natural subsidence in the lagoon of venice, italy. land subsidence, iahs publ. 115511, 777-785. broglio a., favero v., marsale e., 1987, ritrovamenti mesolitici attorno alla laguna di venezia. rapporti e studi, istituto veneto di scienze, lettere ed arti, 1100, venezia. bullock p., fedoroff n., jongerius a., stoops g., tursina t. & babel u., 1985 handbook for soil thin section description. waine research publications. buurman p., 1970 pollen analysis of holocene and pleistocene sediments in the neighbourhood of portogruaro (venezia-italy). mem. biogeogr. adriatica, 88 (1969-70), 41-51. calderoni g., paganelli a. & sartori e., 2000 la presenza di sedimenti marini, riferibili al tirreniano, in una carota della laguna di venezia, attraverso una indagine palinologica. aiqua congress, “l’eemiano e il tirreniano in italia”, verona, 12-13 september 2000, 36-37. carbognin, l., gatto, p. & marabini, f., 1984 the city and the lagoon of venice, a guidebook on the environment and land subsidence. third international symposium on land subsidence, municipality of modena, modena. carbognin l. & tosi l., 2003 il progetto ises per l’analisi dei processi di intrusione salina e subsidenza nei territori meridionali delle province di padova e venezia. progetto ises, grafiche erredici, padova. castiglioni g.b., 1986 recenti studi sulla laguna di venezia. rivista geografica italiana, 9933,, 415-423. crowley t.j. & north g.r., 1991 paleoclimatology. oxford monographs on geology and geophysics, oxford university press, new york. favero v., alberotanza l. & serandrei barbero r., 1973 aspetti paleoecologici, sedimentologici e geochimici dei sedimenti attraversati dal pozzo ve 1bis cnr. c.n.r., istituto per la dinamica grandi masse, tech. rep. 63, venezia. galassi p. & marocco r., 1999 relative sea level rise, sediment accumulation and subsidence in the caorle lagoon (northern adriatic sea, italy) during the holocene. il quaternario, 12(2). gatto p., 1980 il sottosuolo del litorale veneziano. c.n.r., istituto per lo studio della dinamica delle grandi masse, tech. rep. 108, venezia. gatto p. & previatello p., 1974 significato stratigrafico, comportamento meccanico e distribuzione nella laguna di venezia di un’argilla sovraconsolidata nota come “caranto”. c.n.r., istituto per lo studio dinamica grandi masse, tech. rep. 67, venezia. gatto p. & carbognin l., 1981 the lagoon of venice – natural environmental trend and man-induced modification. hydrological sciences bullettin, 2266, 379-391. giandon p., garlato a., mozzi p., ragazzi f. & vinci i., 2001 la carta dei suoli del bacino scolante in laguna di venezia. bollettino della società italiana di scienze del suolo, suppl. vol. 50. heim j., 1975 recherches palynologiques sur les pres sales. 1. la lagune de venise. colloques phytosociologiques, 4, 463-469. horowitz a., 1967 palynological studies in the lagoon of venice. mem. biogeogr. adriatica, 77 (1966-67), 17-27. horowitz a., 1992 palynology of arid lands. elsevier, amsterdam. iliceto v., meloni f., mozzi p. & rizzetto f., 2001 il sottosuolo della cappella degli scrovegni a padova. geologia tecnica e ambientale, 99 (4). kent d.v., rio d., massari f., kukla g. & lanci l. 2002 emergence of venice during the pleistocene. quaternary science reviews, 2211 (14-15), 17191727. lowe j.j., accorsi c.a., bandini mazzanti m., bishop a., van der kaars s., forlani l., mercuri a.m., rivalenti c., torri p., watson c., 1996 pollen stratigraphy of sediment sequence from lakes albano and nemi (near rome) and from the central adriatic, spanning the interval from oxygen isotope stage 2 to the present day. mem. ist. ital. idrobiol, 5555, 71-98. matteotti g., 1962 sulle caratteristiche dell’argilla precompressa esistente nel sottosuolo dei venezia marghera. notiziario dell’ordine degli ingegneri della provincia di padova, 66, padova. mcclennen c.e., ammerman a.j. & shock s.g., 1997 framework stratigraphy for the lagoon of venice, italy: revealed in new seismic-reflection profiles and cores. journal of coastal research, 1133 (3), 745-739. mozzi p., 1995 evoluzione geomorfologica della pianura veneta centrale. unpublished phd thesis, university of padua, padova. mozzi p., 1998 nascita e trasformazione della pianura del sile. in: bondesan et al. (eds.) il sile, cierre edizioni, verona. mullenders w., favero v., coremans m. & dirickx m., 1996 analyses polliniques de sondages a venise (ve-i, veibis, ve-ii). in: gullentops f. (ed.), pleistocene palynostratigraphy, aardkundige mededelingen, 77, leuven. orombelli g. & ravazzi c., 1996 the late glacial and early holocene: chronology and paleoclimate. il quaternario, 99(2), 439-444. paganelli a., 1967 primi risultati di alcune analisi polli209 niche eseguite su una terebrazione di porto marghera (venezia). mem. biogeogr. adriatica, 77, 151-157. paganelli a., 1996a a palynological study of forest vegetation in the veneto-po plain. allionia, 3344, 189-217. paganelli a., 1996b evolution of vegetation and climate in the veneto-po plain during the late-glacial and the early holocene using pollen-stratigraphic data. il quaternario, 99, 581-590. paganelli a. & miola a, 1991 chestnut (castanea sativa mill.) as an indigenous species in northern italy. il quaternario, 44, 99-106. schiozzi l. & brambati a., 2000 evoluzione paleoambientale tardoquaternaria dell’isola di s. erasmo (laguna di venezia). studi trentini di scienze naturali acta geologica, 7777, 139-154. serandrei barbero r., albani a.d. & zecchetto s., 1997 palaeoenvironmental significance of a benthic foraminifera from an archaeological excavation in the lagoon of venice. palaeogeography, palaeoclimatology, palaeoecology, 113366,, 41-52. serandrei barbero r., lezziero a., albani a. & zoppi u., 2001 depositi tardo-pleistocenici ed olocenici nel sottosuolo veneziano: paleoambienti e cronologia. il quaternario, 1144(1), 9-22. stuiver m. & reimer p.j.,1993 extended 14c data base and revised calib 3.0 14c age calibration program. radiocarbon, 3355, 215-230. tosi l., 1994 l’evoluzione paleoambientale tardo-quaternaria del litorale veneziano nelle attuali conoscenze. il quaternario, 77(2), 589-596. 210 imp.cattuto_gambini& il ruolo della geomorfologia nella tutela della torre pendente di vernazzano (umbria) carlo cattuto1, ermanno gambini 2 & lucilia gregori 3 1 dipartimento di scienze della terra università degli studi di perugia, cattuto@unipg.it; lucilia@unipg.it 2 dipartimento di filosofia linguistica e letterature università degli studi di perugia riassunto: c. cattuto, e. gambini & l. gregori, il ruolo della geomorfologia nella tutela della torre pendente di vernazzano (umbria). (it issn 0394-3356, 2007). lungo il versante a oriente del lago trasimeno, presso la confluenza di due torrenti (f.so tegone e t. rio), si trovano i ruderi di un castello medievale del quale è rimasta pressoché intatta soltanto la torre di guardia; a causa della sua vistosa inclinazione, questo possente elemento architettonico è noto come la torre pendente di vernazzano. gli insediamenti del castello (case, chiese, mura, ecc.) sono stati progressivamente raggiunti e portati alla distruzione dai fenomeni franosi che hanno accompagnato la profonda e rapida incisione del f.so tegone e del t. rio entro la potente pila di “arenarie del trasimeno”, affioranti nel territorio come strati e banchi di arenarie e di calcareniti caratterizzati da un elevato grado di fratturazione. la rapida evoluzione dei versanti ha ridotto il vasto piano fondale del castello ad un’esigua superficie, limitata da un’alta scarpata verticale, continuamente ridotta da crolli lungo tutto il suo bordo. anche la torre pendente è stata raggiunta dalla nicchia di distacco di un’ampia frana e la sua inclinazione deriva dallo scivolamento e dal collasso della fondazione entro la pila litoide, progressivamente disarticolata dai fenomeni franosi. come intervento di “primo soccorso”, per evitare il crollo rovinoso della torre, è stato realizzato un sistema di ancoraggio, mediante gabbia d’acciaio e tiranti, ma si dovrà intervenire anche sul piano fondale della torre pendente (ancora ignoto), sul drenaggio delle acque dall’intera superficie e sulla riduzione dell’erosione al piede del versante. abstract: c. cattuto, e. gambini & l. gregori, the role of geomorphology in the conservation of the leaning tower of vernazzano (umbria). (it issn 0394-3356, 2007). in the estern side of the trasimeno lake, near the confluence between tegone and rio streams, lie the ruins of a medieval castle of which only the guard tower remains almost intact. because of its visible inclination this mighty architectural feature is known as the leaning tower of vernazzano. the castle premises (houses, churches, walls, etc.) have been progressively affected and destroyed by the landslide processes associated with the deep and rapid erosion of the tegone and rio streams within the thick layer of “arenarie del trasimeno” sandstone, surfacing as highly fractured layers and beds of sandstone and calcarenites. the fast evolution of the slopes has reduced the large foundation plane of the castle to a small surface, delimited by a high vertical escarpment continuously reduced by rockfalls along its whole edge. on top of the above surface activity, deeper and more complex landslide processes are present which – together with the rotational displacements in the rock – have been affecting the nort-eastern part of the relief supporting the leaning tower. downstream of this structure, even though at a significant distance, lies a disordered pile of stones, eradicated trees, and layers and blocks of rock sloping down into the bed of the rio torrent. the movement of this aggregate doesn’t occur as a whole, but happens through rockfalls and landslides occurring at different moments and locations. this alternates with periods of comparative stability, to the point that a path leading to the tower lies over the pile, even though it often gets interrupted or dragged downstream. this landslide event appeared localized and ascribable to the stream erosion at the base of a detritic cone. the geomorphologic study of the area, instead, has shown that the landslide is the surface manifestation of deeper and more complex landslides that can be regarded as rotational displacements in rock. such displacements have eventually reached the foundation zone of the leaning tower, triggering planar sliding phenomena which led the tower to lose its verticality, leaning in the directions of the strata. as a first-aid measure to prevent the collapse of the tower, an anchorage system consisting of a steel cage and tie rods was deployed, but in the future it will be necessary to work on the (still unknown) foundation plane of the tower, on draining water from the entire surface and on reducing the erosion at the base of the slope. parole chiave: geoarcheologia, geomorfologia, reticolo idrografico, umbria, lago trasimeno. keywords: geoarcheology, geomorphology, hydrographic pattern, umbria region, trasimeno lake. il quaternario italian journal of quaternary sciences 19(2), 2006 233-240 introduzione circa 200 m a nw del piccolo centro abitato di vernazzano, in comune di tuoro sul trasimeno (pg), si trovano i resti di un antico castello tra i quali spicca un’alta torre vistosamente inclinata verso ne (fig. 1) e perciò comunemente indicata e nota come la “torre pendente” di vernazzano. l’area è stata studiata, dal punto di vista storico e geologico (cattuto c. & gambini e., 2002), ipotizzando le cause che hanno condotto alla distruzione del castello e alla progressiva perdita della verticalità della torre. sulla base di questi studi è stato realizzato un progetto per la messa in sicurezza di questa importante testimonianza del passato. condizioni geomorfologiche generali l’area d’interesse, ubicata lungo il versante a oriente del l. trasimeno, comprende parte del versante sudoccidentale del m. castiglione (fig. 2) ed è solcata 234 c. cattuto, e. gambini & l. gregori da due corsi d’acqua, il f.so tegone e il t. rio, che confluiscono nei pressi del vecchio centro abitato di vernazzano. la torre pendente si colloca a nord della confluenza tra i due corsi d’acqua (fig. 3), sopra un rilievo la cui sommità risulta “spianata”, poco sopra l’isoipsa dei 375 m, da fenomeni di dubbia interpretazione. e’ probabile che detta superficie sia riferita ad antichi fenomeni erosivi del ciclo fluviale della valle del trasimeno (cattuto c. et alii, 1992) e che quindi si identifichi, in larga misura, come terrazzo orografico, prodotto dalla tettonica e dal conseguente adattamento del reticolo idrografico locale (fig. 4). la stessa superficie, tuttavia, è stata modellata, almeno in parte, per esigenze agricole e per necessità di insediamento. la profonda incisione operata dal f.so tegone e dal t. rio ha provocato la rapida regressione dei loro versanti al punto che, attualmente, la superficie spianata sulla quale sorge la torre pendente è limitata da una netta scarpata praticamente verticale. particolarmente energica risulta l’erosione del t. rio che, nel tratto compreso tra i 300 e i 500 m s.l.m., sta ancora incidendo il “gradino”, corrispondente alla superficie spianata sulla quale era edificato il castello, prodotto da una faglia diretta (fig. 4). condizioni geologiche generali nell’area in questione affiorano le “arenarie del trasimeno”, arenarie quarzoso feldspatiche micacee alternate con argille e marne, considerate torbiditiche ad “affinità toscana” (boscherini a. et alii, 1982 ; damiani a.v. & pannuzi l, 1985), che si presentano in banchi di notevole potenza, assetto monoclinalico e immersione nordorientale. mentre lungo il versante sinistro del f.so tegone gli strati sono a reggipoggio, lungo il versante destro del t. rio, il generale andamento a franapoggio (fig. 5) è localmente modificato dalla presenza di pieghe a stretto raggio e, soprattutto, dalla sconnessione delle rocce provocata da movimenti franosi (fig. 6). spesso inoltre, si rileva un assetto decisamente caotico degli strati, mentre alcune faglie dirette di modesto rigetto dislocano il versante “gradonandolo” fin quasi al lago trasimeno. caratteristiche litologiche per comprendere l’evoluzione dei versanti del rilievo sul quale si trova la torre pendente, si ricorda che: le rocce in affioramento sono in prevalenza carbonatiche e fig. 1 la torre pendente di vernazzano in comune di tuoro sul trasimeno. the leaning tower of vernazzano in tuoro sul trasimeno. fig. 2 cartografia geologica schematica dell’area della torre pendente: 1. direzione/immersione degli strati, 2. faglia diretta di modesto rigetto, 3. depositi clastici di copertura (detrito di falda, colluvioni, alluvioni), 4. basamento litoide costituito dalle “arenarie del trasimeno” (oligocene superiore – burdigaliano medio). schematic geological map of the leaning tower area: 1. strike and dip of the strata, 2. normal fault, 3. clastic deposits (debris, colluvium and alluvial), 4. bedrock composed of “arenarie del trasimeno” (upper oligocene – middle burdigalian). affette da un elevato grado di fratturazione; infatti le arenarie, e ancor più le calcareniti la cui potenza nei banchi supera spesso il metro, in virtù della loro 235il ruolo della geomorfologia nella tutela ... durezza e fragilità, sono intensamente fratturate al punto che, a luoghi, il complesso litoide, almeno nell’area d’indagine, può essere assimilato ad un mezzo semicoerente e/o incoerente (fig. 6); i giunti di strato sono segnati dalla presenza di veli argillitici e da marne fogliettate che spesso costituiscono non solo una superficie di discontinuità, ma anche un piano di possibile e facile scivolamento. solo raramente, infatti, i giunti di strato sono interessati da ondulazioni e strutture sedimentarie (ripple marks, flute casts, ecc.) in grado di conferire loro “scabrezza” e, quindi, incremento della resistenza allo scorrimento; la presenza del lago trasimeno determina elevati valori annui dell’umidità relativa e questa, sui corpi litici molto fratturati e relativamente freddi, dà luogo a “precipitazioni occulte” in grado di incrementare l’infilfig. 3 schema geomorfologico dell’area della torre: 1. direzione/immersione strati, 2. frana, 3. scarpata, 4. deposito colluvio-alluvionale, 5. superficie spianata, 6. corso d’acqua, 7. sentiero, 8. manufatto. geomorphological scheme of the leaning tower area: 1. strike and dip of strata, 2. landslide, 3. escarpment, 4. colluvial and alluvial deposits, 5. flattened surface, 6. strema, 7. path, 8. artifact. fig. 4 schema morfoevolutivo del versante orientale del lago trasimeno e relazione con i processi erosivi dei corsi d’acqua che lo alimentano: 1. depositi colluvio-alluvionali, 2. bedrock marnoso arenaceo, a. faglie dirette di modesto rigetto intercettano il profilo dei corsi d’acqua incrementando i dislivelli locali, b. questo evento provoca il “ringiovanimento” del ciclo erosivo dei corsi d’acqua che, ancora oggi, incassano profondamente nel bedrock il loro alveo; a quote ricorrenti restano superfici spianate utilizzate per l’agricoltura e gli insediamenti. morphoevolutionary scheme of the eastern side of the trasimeno lake, and relation to the erosional processes driven by feeder streams: 1. colluvium and alluvial deposits, 2. bedrock (marls and sandstones), a. normal faults with small throw cross the path of water streams, increasing local height differences, b. this event causes the “rejuvenescence” of the erosional cycle of water streams which – still today – carve their channel deeply into the bedrock. at specific heights there are flattened surfaces used for agriculture and settlement. fig. 5 il colle sul quale si erge la torre pendente è limitato da un’alta e ripida scarpata che evidenzia gli strati e i banchi delle “arenarie del trasimeno”. the hill over which the leaning tower lies is limited by a tall and steep escarpment that highlights the strata of the “arenarie del trasimeno”. fig. 6 l’elevato grado di fratturazione delle rocce affioranti ne assimila il comportamento meccanico a quello delle rocce semicoerenti e incoerenti. the high degree of fracturing of surfacing rocks makes their mechanical behavior similat to that of semi-coherent and incohesive rocks. 236 trazione, lo stato di saturazione del terreno e finanche una moderata dissoluzione delle rocce carbonatiche; l’escursione termica diurna può essere molto alta e, frequentemente, durante l’inverno, il termometro oscilla sopra e sotto lo zero; in queste condizioni i fenomeni locali di gelo-disgelo diventano morfogeneticamente importanti; l’elevato grado di fratturazione delle rocce permette alle acque meteoriche di infiltrarsi profondamente entro la pila litoide e di esercitare locali, rapidi incrementi del carico idrostatico, in specie dove la presenza di livelli a bassa permeabilità allunga i tempi di corrivazione sotterranea creando accumuli idrici temporanei; durante o dopo piogge abbondanti, infatti, lungo i versanti del rilievo sul quale è posta la torre, è facile rilevare emergenze idriche un po’ ovunque mentre clasti e massi anche di notevoli dimensioni crollano a valle in grande quantità. i ruderi del castello e la torre pendente di vernazzano la superficie spianata indicata è ingombra di pietrame proveniente dalle macerie dei manufatti ivi costruiti; tra il materiale diruto emergono porzioni di muri ancora in posto, la base di una torre rotonda e, un po’ più distante, una piccola chiesa (fig. 7), probabilmente s. maria delle trosce. la torre pendente, a base rettangolare (m 5 x 5.5), ha un’altezza massima di m 20.95 alla sommità dello spigolo di sw e di m 20.42 a quella dello spigolo di ne verso il quale la torre ha raggiunto la massima inclinazione. nel perdere la verticalità, la parte sommitale della torre ha subito anche una evidente rotazione passando progressivamente dalla sezione rettangolare (angoli di 90°, ancora mantenuti alla base), ad una sezione rombica. la parte sommitale dello spigolo di ne, sottoposta a maggior tensione, si è “allentata” per aver superato i 90° e le pietre che componevano la muratura si sono distaccate, distanziate e infine sono crollate (fig. 8). oltre quelle indicate, non esistono altre misure esatte, anche se buattini a. (1846) ha fornito un’accurata descrizione della torre e misure sufficientemente attendibili. questo autore descrive anche la base della torre che oggi non è visibile, perché mascherata da macerie e, soprattutto, perché infossata nel terreno. il confronto tra le misure fornite dal buattini e quelle oggi rilevabili dimostra come, in 150 anni, la torre si sia : infossata nel terreno per almeno m 1.80 (il buattini colloca, a m 4.63 da terra, la porta di accesso alla torre, mentre oggi la stessa si trova a m 2.80), inclinata ulteriormente (il fuori piombo alla base della torre, misurato dal buattini in m 2.35, oggi è di m 3.88; pertanto, nel 1846, l’inclinazione della torre era di circa 7°, oggi è quasi il doppio (13° lungo il lato ovest). la distruzione del castello: idrografia e stabilità dei versanti in virtù delle caratteristiche meccaniche e del grado di fratturazione delle rocce, l’arretramento dei versanti si attua essenzialmente per fenomeni gravitativi; più spesso mediante crolli (rock fall) di massi e di pietrisco, ma sono riconoscibili anche fenomeni più complessi, compositi (wp/wli, 1993), come valanghe di detrito (debris avalanches) e scorrimenti rotazionali in roccia. al riguardo si segnala il sistema franoso che più direttamente minaccia la stabilità della torre e che è perfettamente visibile da chi percorra il sentiero che, dall’alveo del t. rio, si inerpica fino alla torre pendente. tale sentiero viene spesso spostato verso valle e parzialmente o completamente ostruito da corpi franosi diversi, sovrapposti e/o accostati, che si muovono in modo autonomo, in tempi diversi e senza apparenti rapporti di causa/effetto. fig. 7 il rudere della piccola chiesa di s. maria delle trosce. the remains of the small curch of st. mary of trosce. fig. 8 nel perdere la verticalità, la torre ha subito anche una vistosa rotazione al punto che la sua porzione sommitale, in origine a sezione rettangolare, si è progressivamente deformata diventando romboidale; dove l’angolo ha superato i 90° le pietre di costruzione si sono distaccate e poi sono crollate. on losing its verticalità, the tower underwent a visibile rotation, to the point that its top, originally rectangular, was progressively deformed, becoming rhomboidal. in places where the angle exceeded 90 degrees, the construction stones have detached and then have fallen down. c. cattuto, e. gambini & l. gregori 237 seguendo l’assetto degli strati e l’evoluzione dei fenomeni franosi che interessano il sentiero, si è ipotizzato che, sotto la spinta sia del carico litostatico che idrostatico, l’ammasso roccioso possa muoversi anche lungo piani di scivolamento debolmente inclinati contromonte, sia esistenti (ondulazioni degli strati) che di neoformazione. in pratica si tratta di scorrimenti rotazionali in roccia che, presso la superficie, con la progressiva diminuzione dei vincoli laterali, danno luogo a crolli e a locali colamenti. questo rapido allontanamento del materiale provoca una nuova depressione “a tergo” innescando altri fenomeni di tensione, movimento reciproco dei blocchi fratturati, ampliamento delle fratture e scivolamento planare delle rocce sovrastanti. frequentemente gli ammassi litici sono omogenei, mantengono pressoché indisturbata la stratificazione e sembrano in posto; si ritiene pertanto che questi corpi rocciosi, che emergono come schegge dalla massa litica ridotta in clasti, possano muoversi, episodicamente, lungo piani preferenziali di scivolamento, talora cambiando la direzione del movimento. più spesso tuttavia l’ammasso roccioso è completamente caotico e in esso si trovano massi e blocchi di roccia, pietrisco, terra e resti vegetali (arbusti e tronchi). la geometria di questo ammasso e il tipo di movimento sono riconducibili al “colamento”, tuttavia l’elevata pendenza dei vari piani di scivolamento lungo i quali si realizza il franamento lo identificano, più spesso, come “debris avalanche” (varnes d.j., 1978). già presso la base della torre sono visibili gradini e lesioni del terreno, assimilabili a nicchie di distacco che disarticolano la massa rocciosa tanto profondamente che ormai dalla torre all’alveo del t. rio il corpo franoso, almeno in superficie, può essere considerato unico (fig. 9). questo movimento franoso si è evoluto a causa della progressiva erosione retrogressiva dei versanti tutt’attorno al rilievo che sovrasta la confluenza t. rio/f.so tegone (fig. 9), portando un po’ alla volta al crollo delle strutture del castello ivi edificato. ancora oggi, lungo l’alveo dei due torrenti, tra il materiale che ne costituisce il carico solido, è facile rinvenire pietre squadrate che possono essere riferite a strutture murarie. dapprima i piani fondali devono aver subito fenomeni assimilabili a cedimenti differenziali (gli “sprofondamenti” di cui parla il buattini) a causa dello scivolamento planare degli strati sui quali poggiavano e, quindi, della rottura a comfig. 9 l’erosione in alveo e i processi gravitativi hanno provocato la distruzione del castello di vernazzano e l’inclinazione della torre: 1. la torre, probabilmente quella di “guardia” del castello di vernazzano, è stata edificata nel xiii secolo, 2. la profonda incisione operata dal f.so tegone e dal t. rio provoca la progressiva distruzione del castello e, già dal 600, sono segnalati i fenomeni franosi, ancora in atto, che porteranno la torre ad inclinarsi verso ne. nel 1846 l’inclinazione della torre aveva raggiunto i 7°, 3. situazione attuale. la torre è inclinata di ben 13° ed è profondamente lesionata. streams erosion and gravitative processes caused the destruction of the castle of vernazzano, and the inclination of the tower: 1. the tower, probably the guard tower of the castle of vernazzano, was built in the 13th century, 2. the deep incision effected by the tegone and rio rivers causes the progressive destruction of the castle. landslides, still going on, have been reported since 1600. they lead the tower to lean towards north-east. in 1846 the inclination of the tower had reached 7 degrees, 3. current status. the tower is inclined by as much as 13 degrees and is deeply damaged. il ruolo della geomorfologia nella tutela ... 238 pressione dell’appoggio fondale via via sempre meno contrastato dallo scorrimento rotazionale dell’ammasso roccioso; a seguito di questi movimenti, le strutture si sono inclinate verso valle, come la torre, seguendo il movimento della massa litica in questa direzione (o, più raramente, “contromonte”) e, infine, sono crollate, insieme con ampie porzioni di roccia, per mancanza di sostegno al piede 1. datazione del fenomeno franoso che interessa la torre attorno al 1250, quando fu edificato il castello, l’area fondale dava probabilmente le migliori garanzie di stabilità, in virtù del tipo di roccia affiorante e della situazione topografica locale (superficie spianata), ma proprio le condizioni geomorfologiche che fornivano alla costruzione una posizione dominante e inaccessibile, nel lungo tempo, l’hanno portata alla distruzione. e’ diffusa la credenza che il castello sia crollato a seguito dei terremoti ma, come rilevato da cattuto c. & gambini e. (2002), almeno la torre ha resistito abbastanza bene agli eventi sismici che, a più riprese, hanno interessato il territorio orientale del lago trasimeno; tra quelli più intensi (sup. int. vi della scala mercalli), baratta m. (1901) e postpischl d. (1985) segnalano quelli distruttivi di sansepolcro del 1345 (int. ix), di città di castello del 1389 (int. viii) e di sansepolcro e monterchi del 1414. che hanno raggiunto l’intensità ix della scala mercalli. tuttavia, storicamente, non viene segnalato alcun rapporto tra questi terremoti e la distruzione del castello, mentre si deve considerare che lo shock sismico può avere, ripetutamente, innescato e/o favorito i movimenti franosi, in specie quando il terreno si trovava in condizioni sature. non v’è dubbio quindi che i fenomeni di frana e di crollo conseguenti la profonda incisione operata dal t. rio 2 siano i veri responsabili della progressiva distruzione dell’area edificata. agli inizi del seicento sono infatti segnalati i primi fenomeni franosi, ma i più deleteri si sono manifestati in un periodo abbastanza breve, tra il 1750 e il 1775 e, a causa di questi, la torre si è infossata nel terreno. nello stesso periodo sono segnalati (gambini e., 1995) i più alti livelli idrici del lago trasimeno, ovviamente legati ai più abbondanti afflussi meteorici, gli stessi che potrebbero aver aggravato l’instabilità del territorio. e’ molto probabile quindi che l’elevato grado di fratturazione della roccia e soprattutto la mancanza di vincoli laterali (rimossi dal franamento) abbiano portato allo schiacciamento dell’appoggio fondale e al cedimento della torre 3. considerati i meccanismi di frana (tensione e lesionamento della roccia, ampliamento delle fratture con scorrimento della porzione a valle, parziale rottura a compressione della roccia in fondazione rapidamente sottoposta al carico della struttura e, infine, scivolamento della stessa verso valle), si ritiene che l’inclinazione della torre non si sia attuata gradualmente, ma procedendo a “scatti” corrispondenti ad eventi concomitanti (precipitazioni gravose, deflussi sotterranei elevati, shock sismici, ecc.). 1 anche dalla documentazione storica si ricava che, sulla spianata ove erano fondati i vari edifici, si sono manifestate lesioni sempre più ampie del terreno e “sprofondamenti” (cavità riconducibili probabilmente all’ampliamento delle fratture tra i blocchi calcarenitici in movimento relativo tra loro), entro cui franavano il pavimento delle abitazioni o intere porzioni murarie. questi eventi sono segnalati già nei primi decenni del 1400, tanto che nel 1455 viene restaurata la stessa torre, forse già danneggiata dai cedimenti che ne hanno preceduto l’inclinazione, mentre nel 1457 viene rifatta la rocca di vernazzano che, in alcune parti, “minacciava rovina” (pellini p., 1664). nei primi decenni del 1500 le mura del castrum risultano semidirute e la documentazione, fattasi più dettagliata dalle “relazioni” delle visite pastorali effettuate dai vescovi al castello di vernazzano e in particolare alla chiesa di s. michele arcangelo che sorgeva presso la torre, dimostrano che i fenomeni di cedimento e di lesionamento sono progressivi, seppure alternati con periodi di minore attività. infatti, nel 1626, nella relazione del vescovo de torres (archivio diocesi perugia, vol. xv), vengono segnalati i primi danni alle fondazioni della chiesa, successivamente, nel 1655, come si legge nella relazione della visita pastorale del vescovo monaldi (archivio diocesi perugia, vol. xx) si tenta di riparare la stessa chiesa con l’introduzione di terra entro i vuoti che si erano prodotti sotto le fondazioni, ma nel 1747, a seguito della visita del vescovo ferniani (archivio diocesi perugia, vol. xxvii) la stessa chiesa è dichiarata inagibile a causa di lesioni murarie e cedimenti del pavimento molto gravi e infine, nel 1763 il vescovo amadei (archivio diocesi perugia, vol. xxviii), dichiara impossibile qualsiasi opera di riparazione e decreta l’abbandono della struttura. curiosamente, anton maria garbi, un noto pittore locale, in un pregevole quadro del 1769 dipinge parte del castello ancora in piedi, così come la chiesa di s. michele arcangelo e la torre, in posizione praticamente verticale; ma secondo il buattini (1846), la chiesa di s. michele arcangelo venne chiusa al culto nel 1772 ”per lo spavento arrecato alle genti dalle pendenze della torre”. stando a questi documenti, pertanto, la torre sarebbe stata coinvolta nel movimento franoso nel brevissimo periodo di un triennio. 2 ovviamente non è nota la profondità del f.so tegone e del t. rio, rispetto al piano di posa delle strutture murarie edificate nel tredicesimo secolo; tuttavia è probabile che la posizione “dominante” del castello derivasse proprio dalla profonda incisone dei due torrenti, compresa almeno tra i 5 e i 10 m. attualmente il dislivello tra la base della torre e il t. rio è di circa 20 m, pertanto è probabile che, in circa sette secoli, l’erosione in alveo abbia raggiunto un tasso medio di 1.5 cm/anno. 3 pur in assenza di dati geotecnici puntuali è di misure esatte relative alla larghezza delle sue fondazioni, è interessante notare che la torre, con i suoi 20 m di altezza e con una base di m 5 per 5.5, progressivamente rastremata verso l’alto, raggiunge un volume fuori terra di poco superiore ai 500 mc; dal momento che il vuoto interno è di soli 30 (forse 40) mc, il volume complessivo ammonta a 460/470 mc. la roccia utilizzata per la sua costruzione, seppure con i vuoti delle connessure, può raggiungere un peso di volume di almeno 2.5 t/mc; pertanto il peso complessivo della torre potrebbe aggirarsi attorno alle 1.200 t corrispondenti, in fondazione e se questa fosse una superficie piana, ad almeno 4 kg/cm2. questo valore non è particolarmente elevato, ma la diversa risposta meccanica delle rocce in fondazione (argilliti, marne, arenarie e calcareniti), il loro elevato grado di fratturazione, la possibilità di locali fenomeni di dissoluzione e di variazione rapida del carico idrostatico, possono giustificare la locale, bassa resistenza alla compressione della roccia e, quindi, il cedimento differenziale delle strutture e il loro collasso non appena l’appoggio fondale viene rimosso. c. cattuto, e. gambini & l. gregori conclusioni e messa in sicurezza della torre lo studio geomorfologica del territorio ha permesso di legare, con rapporti di causa/effetto, fenomeni e situazioni che sembravano indipendenti, quali: l’inclinazione della torre, attribuita a cedimento differenziale del terreno fondale, l’ammasso di pietrame, alberi e strati di roccia accumulati, e in movimento come valanga di detrito, lungo il versante destro del t. rio, abbastanza lontano dalla torre, il continuo crollo di materiale roccioso dalle scarpate richiamato a valle dallo scalzamento al piede operato dall’erosione del t. rio. quello che sembrava un semplice fenomeno di scivolamento del materiale clastico, accumulato come cono detritico lungo il versante destro del t. rio, si è rivelato invece la manifestazione superficiale di un fenomeno franoso più profondo e complesso, in gran parte riconducibile a scorrimenti rotazionali in roccia in movimento retrogressivo che, almeno nella zona sommitale del rilievo, innescano fenomeni di scivolamento planare. la torre pendente, seppur lontana dalla valanga di detriti segnalata lungo il versante del t. rio, è stata interessata, in un primo tempo, dallo scivolamento planare delle rocce in fondazione 4 e si è inclinata; ora è molto vicina alla nicchia di distacco del più alto degli scorrimenti rotazionali profondi ed è quindi prossima al collasso totale. negli anni 2004/2005 il comune di tuoro ha realizzato l’ardito progetto di messa in sicurezza della torre elaborato dallo studio tecnico ing. o. zucchini di camucia. nell’area prossima al ciglio occidentale della superficie spianata è stato incassato un voluminoso blocco di calcestruzzo (circa 150 mc) al quale sono state ancorate 5 coppie di cavi d’acciaio che tirantano una struttura costituita da angolari d’acciaio disposti lungo i quattro spigoli della torre, per tutta la loro altezza (fig. 10). senza questo lavoro di “primo soccorso” la torre sarebbe già crollata. tuttavia il progetto deve essere completato con la realizzazione di altre opere tese a frenare l’erosione in alveo del t. rio (costruzione di briglie), a ridurre l’infiltrazione delle acque sul corpo di frana e sull’intera zona ove affiorano i ruderi del castello (opere di drenaggio), a bonificare, per quanto possibile, la frana stessa (infiltrazioni di resine e/o malta cementizia) e, infine, a mettere in luce quanto di archeologicamente interessante emergerà dagli scavi che verranno condotti, alla base della torre, per controllarne la tipologia e lo stato delle fondazioni. bibliografia baratta m. (1901) i terremoti d’italia. saggio di storia, geografia e bibliografia sismica italiana. bocca, torino. boscherini a., nocchi lucarelli m. & pialli g. (1982) geologia della riva etrusca del tevere tra le confluenze del t. niccone e del t. nese. rend. acc. sc. fis. e nat., soc. naz. di sc. e lett. in napoli, 48, 409-438. 239 4 durante lo scavo per la posa del blocco di calcestruzzo al quale ancorare la torre, a circa 3 m di profondità dal piano di campagna, è stato intercettato il probabile piano di scivolamento planare più direttamente responsabile dell’inclinazione della torre. e’ facilmente riconoscibile poiché si identifica come piano di stratificazione sopra al quale gli strati calcarenitici sono ridotti in blocchi distanziati da ampie fratture riempite con depositi eluviali mentre, sotto questo piano, la roccia è omogenea e si può seguire il profilo degli strati per tutta la loro estensione, dal momento che le fratture non sono mai beanti e molte sono cementate da calcite. fig. 10 per sostenere il peso della torre, contrastandone la caduta, è stata allestita una gabbia d’acciaio tirantata e ancorata ad un blocco di calcestruzzo. in order to support the weight of the tower, preventing its fall, a steel cage was built, anchored with tie rods to a block of concrete. il ruolo della geomorfologia nella tutela ... 240 buattini a. (1846) memoria sopra le pendenze della torre di vernazano. tipografia di v. santucci, perugia. cattuto c. & gambini e. (2002) la “torre pendente” del castello di vernazzano. arnaldo lombardi editore. cattuto c., cencetti c., gregori l. (1992) il pliopleitocene nell'area medio-alta del bacino del fiume tevere: possibile modello morfotettonico studi geolog. camerti vol. spec, (1992/1),103108. damiani a. v. & pannuzi l. (1985) unità litologiche nell’ambito degli “argilloscisti varicolore” fra il cortonese e l’eugubino e preliminari considerazioni paleogeografiche e stratigrafiche. boll. serv. geol. d’ it., 103, 241-276. gambini e. (1995) le oscillazioni di livello del lago trasimeno. quaderni museo pesca lago trasimeno, 2. pellini p. (1664) dell’historia di perugia. venezia postpischl d. (1985) catalogo dei terremoti italiani dall’anno 1000 al 1980. cnr – pf “geodinamica” n. 114, vol. 2 b. varnes d. j. (1978) slope movements. types and processes. in: schuster & krizek (eds) landslides: analysis and control spec. rep. 176. transp. res. board. national academy of sciences. washington, 11-33. wp/wli international geotechnical societes' unesco working party on world landslide inventory (1993) multilingual glossary for landslides. bitech, richmond, british columbia, 59 pp. ms. ricevuto il 20 febbraio 2006 testo definitivo ricevuto il 31 ottobre 2006 ms. received: february 20, 2006 final text received:october 31, 2006 c. cattuto, e. gambini & l. gregori imp. miola ppoolllleenn ddaattaa ffoorr aa bbiioossttrraattiiggrraapphhyy ooff llggmm iinn tthhee vveenneettiiaann ppoo ppllaaiinn aannttoonneellllaa mmiioollaa11,, ddiieeggoo aallbbaanneessee22,, ggiiaannnnaa vvaalleennttiinnii11,, lliivviioo ccoorraaiinn33 1 dipartimento di biologia – università di padova 2 dipartimento di geologia, paleontologia e geofisica – università di padova 3 dipartimento di statistica – università di padova abstract during the last forty years many works have been published on sedimentary sequences from the planitial area of north-eastern italy. many authors refer about stratigraphic sequences which contained peat layers at different depths from the ground level. radiocarbon dating of peats has been given ages ranging from 22,500 to 18,000 yr bp. the area with suitable conditions for the formation of peat, seems to cover all the venetian planitial area for a brief period of time during the lgm. we are interested in the microfossil content of lgm peats, because it can contribute to the definition of past local hydrological conditions. we would like to answer to the following questions: i) can we say that the same type of vegetation has formed the lgm peats? ii) can we hypothesize that the same hydrological conditions were established during lgm in the plain? iii) can we use the peat horizon as a biozone for the venetian plain? we approach the topic by analysing new pollen data of peat sediments from a coastal area at the north of the venice lagoon, by means of a new statistical method of data analysis, namely the nonparametric combination of dependent permutation (npc) tests (pesarin, 2001). the statistical analysis of pollen data does not include the pollen records from other sites (tab.1), since they are not entirely reported in literature; therefore a successful comparison was not achievable. the npc test results confirm that there aren’t significant differences between the peat sediments. hence we can assert that the area was mostly covered by cyperaceae and poaceae, and this confirm our hypothesis. some other herbaceous taxa were present and many taxa of fungi, algae and mosses. studies for the identification of the latter and other plant fragments are in progress and they will lead to a finer characterization of the plant community. riassunto elementi palinologici per una biostratigrafia dell’ultima espansione glaciale nella pianura padano-veneta. negli ultimi quarant’anni sono stati pubblicati molti risultati di ricerche su sequenze sedimentarie provenienti dall’area planiziale dell’italia nord-orientale. molti autori hanno segnalato la presenza di strati torbosi di un’età compresa tra i 22.500 e i 18.000 a b.p., a profondità diverse dal livello di campagna. ciò suggerisce l’ipotesi che condizioni adatte alla formazione di torbe si siano instaurate in un’area che copriva gran parte della pianura veneta per un breve periodo di tempo in corrispondenza dell’ultima massima espansione glaciale (lgm). lo studio dei microfossili vegetali contenuti nelle torbe può contribuire alla ricostruzione delle condizioni idrologiche in cui si formarono le torbe e a rispondere alle seguenti domande: i) un unico tipo di vegetazione ha formato le torbe lgm della pianura veneta? ii) possiamo ipotizzare che le stesse condizioni idrologiche si siano instaurate nella pianura durante l’ultima espansione glaciale? iii) l’orizzonte torboso può essere considerato una biozona per la pianura veneta? abbiamo iniziato ad affrontare queste problematiche analizzando nuovi dati pollinici ottenuti dall’esame di torbe estratte in quattro sondaggi eseguiti nell’area costiera a nord della laguna di venezia. i dati pollinici sono stati confrontati attraverso un nuovo metodo di analisi statistica, il nonparametric combination of dependent permutation (npc) tests (pesarin, 2001), al fine di verificare l’esistenza di differenze tra i contenuti pollinici dei diversi campioni torbosi. i dati pollinici di altri autori (tab.1) non sono stati compresi nell’analisi eseguita, perché riportati solo parzialmente negli articoli pubblicati. l’npc test non ha individuato differenze tra i dati pollinici delle torbe esaminate, quindi possiamo ipotizzare che l’area a nord della laguna di venezia fosse occupata da una comunità di piante erbacee produttrici di torbe, caratterizzata dalla prevalenza di cyperaceae e poaceae, dalla presenza di callitriche, caltha palustris, hydrocharis morsus-ranae, menyanthes trifoliata, lemna, myriophyllum verticillatum, nuphar luteum, potamogeton subg. p. type e da molti taxa di funghi, alghe e briofite. il riconoscimento di quest’ultimi, la cui analisi è tuttora in corso, sarà di ulteriore aiuto nella ricostruzione dell’intera comunità vegetale. parole chiave: pianura padano-veneta, analisi pollinica, npc test, ultimo massimo glaciale keywords: venetian-po plain, pollen analysis, npc test, last glacial maximum il quaternario italian journal of quaternary sciences 1166(1), 2003, 21-25 iinnttrroodduuccttiioonn during the last forty years many works have been published on sedimentary sequences from the planitial area of north-eastern italy. they report results of lithological, stratigraphical, geological and paleobiological studies (bertolani marchetti, 1967; bortolami et al., 1977; paganelli, 1996a; rizzi longo, 1996; aa. vv., 1999; serandrei barbero et al., 2001). these works have contributed to a better knowledge of the evolution of the area, during late quaternary. they show the importance of floodplain sediments as valuable sources of information for paleoenvironmental reconstruction. in the venetian alluvial plain the sedimentation has been greatly influenced by the evolution of the principal fluvial systems (adige, brenta, piave and tagliamento) and by the sea-level fluctuations (castiglioni & pellegrini, 2001; bondesan et al., 2002). moreover the continental sedimentary sequences from different sites of the plain cannot be easily correlated using lithological data. as far as it concerns the microfossil content of the sediments, it is quite poor in sands, silts and sometimes also in clays: therefore this excludes the use of a biostratigrapic approach to correlate these kinds of sediments. 22 a. miola et al. nevertheless, many authors refer about stratigraphic sequences, which contained peat layers at different depths from the ground level (bortolami et al., 1977; accorsi et al., 1984; castiglioni et al., 1987; paganelli et al., 1988; accorsi et al., 1989; marocco, 1989; calderoni et al., 1996; mullenders et al., 1996; paganelli, 1996b; miola & gallio, 1997; lezziero, 1999; iliceto et al., 2001; serandrei barbero et al., 2001). radiocarbon dating of peats has been given ages ranging from 22,500 to 18,000 yr bp, i.e. the period of peat sedimentation is the lgm (tab. 1). pollen content has been analysed in some of them, but pollen data have not been correlated at a regional scale. the area with suitable conditions for the formation of peat during the lgm, seems to cover all the venetian planitial area (fig. 1). studies on this topic are in progress at the dept. of geography (university of padova). if they confirm that peat layers have been formed during a brief period of time, as some radiocarbon dates seem to suggest, and in an extensive regional area, their deposition may be considered a stratigraphic event for the venetian plain. we are interested in the microfossil content of lgm peats. peat originates mostly from the remains of plant communities, that live in waterlogged conditions. the quality of water, i.e. its dissolved mineral salts content, and the hydrological conditions determine the types of vegetation that live in a peatland (goodwin, 1981). therefore, pollen and spore analysis of peat sediments and the identification of other plant fragments can contribute to the definition of past local hydrological conditions. we would like to answer to the following quefig. 1 location of sites where peat layers from 22,500 to 18,000 yr bp have been found. ubicazione dei siti nei quali è stata segnalata la presenza di strati torbosi di età compresa tra 22.500 e 18.000 anni bp. 1) bernascone (vr), 2) basso acquar, 3) orgiano (vi), 4) villaga barbarano (vi), 5) rubano (pd), 6) galzignano (pd), 7) padova, 8) alveo brenta (pd), 9) conca romea (ve), 10) motte di volpego (ve), 11) pozzo venezia 1bis (ve), 12) la fenice (ve), 13) punta sabbioni (ve), 14) sant’erasmo (ve), 15) treporti (ve), 16) fiorentina (ve), 17) palazzetto (ve), 18) ca’fornera (ve), 19) crosere (ud), 20) latisana (ud), 21) laguna di marano (ud). tab.1 peat layers and relative 14c dates in the venetian plain from literature. età 14c convenzionali di strati di torba rinvenuti nella pianura padanoveneta già pubblicati. ssiitteess ddeepptthh ffrroomm tthhee 1144cc ccoonnvveennttiioonnaall ppoolllleenn rreeffeerreenncceess ggrroouunndd lleevveell ((mm)) ddaattiinnggss ((yyrr bb..pp..)) aannaallyyssiiss bernascone (vr) 5.6-5.7 18,870 ± 300 + accorsi et al., 1989 basso acquar (vr) 16.0-21.0 18,800 ± 2000 + accorsi et al., 1984 orgiano (vi) 4.4-4.5 17,760 ± 160 + paganelli, 1996b villaga barbarano (vi) 6.05-6.25 19,250 ± 210 + paganelli et al., 1988 paganelli, 1996b rubano 5 (pd) 9.40-9.46 19,200 ± 250 castiglioni et al., 1987 rubano 4 (pd) 7.94-8.00 18,100 ± 700 castiglioni et al., 1987 padova c. scrovegni b 15.0 19,830 ± 220 iliceto et al., 2001 galzignano (pd) 3.3-3.4 19,000 ± 1200 + calderoni et al., 1996 miola & gallio, 1997 alveo brenta (pd) 15.5-15.9 20,250 ± 900 bortolami et al., 1977 motte di volpego (ve) 10.6 19,620 ± 315 + bortolami et al., 1977 bertolani marchetti, 1967 sant’erasmo (ve) 19.0-19.4 19,250 ± 300 bortolami et al., 1977 treporti (ve) 27.5 22,440 ± 500 bortolami et al., 1977 punta sabbioni (ve) 18.0-18.5 20,000 ± 400 bortolami et al., 1977 conca romea (ve) 13.2-13.4 20,950 ± 900 bortolami et al., 1977 conca romea (ve) 6.4-6.7 19,410 ± 800 bortolami et al., 1977 la fenice (ve) 12.0 20,120 ± 90 serandrei barbero et al. 2001 ponte moro 1 (ve) 10.19 19,700 ± 250 serandrei barbero et al. 2001 p.zo venezia 1bis (ve) 24.3 21,750 ± 730 + mullender et al., 1996 venezia 12.0-10.0 19,800 ± 250 lezziero, 1999 laguna di marano s9 22.0 20,200 ± 720 marocco, 1989 candelù (tv) 20.3-20.5 19,170 ± 400 bortolami et al., 1977 stions: i) can we say that the same type of vegetation has formed the lgm peats? ii) can we hypothesize that the same hydrological conditions were established during lgm in the plain? iii) can we use the peat horizon as a biozone for the venetian plain? the purpose of this work is to approach the topic by comparing pollen data from peat sediments using a suitable statistical method. we recently analysed pollen and spores content of peat from a coastal area at the north of the venice lagoon. peat samples from palazzetto (pal-1819, pal-1834, pal-2034, pal2039, pal-2049), fiorentina (fio-1988, fio-1992), and ca’ fornera (caf-1956, caf-1967, caf-1978, caf1989) have been drilled near the river piave, between san donà di piave (venezia) and the coast of the adriatic sea, at a depth of about 20 m from the ground level (bondesan et al., 2003). latisana samples (lat410, lat-420) have been drilled near the tagliamento river at a depth of about 4 m. latisana samples have been radiodated 18,100±100 yr bp (fontana, pers. comm.). radiodating of the other samples are in progress. all the samples are characterized by low percentages (<20%) of arboreal taxa, among which pinus is the most abundant, followed by betula, abies, picea, larix, ephedra and juniperus. boreal broadleaf plants are rare. the grasses are represented by local aquatic plants and by cyperaceae, poaceae, artemisia, chenopodiaceae, caryophyllaceae, asteraceae asteroideae and apiaceae. this fossil pollen assemblage is indicative of a very sparse arboreal vegetation, with cold-climate taxa and it is often correlated to the last pleniglacial period (paganelli, 1996a) we compared our pollen records by means of a new statistical method of data analysis, namely the nonparametric combination of dependent permutation (npc) tests (pesarin, 2001). this new method has been adopted because the data configuration is characterized by a relatively high number of variables, i.e. pollen taxa, compared to the number of statistical units, i.e. peat samples. in this situation a standard multivariate approach, as principal component analysis, is not appropriate and applicable and in general it does not permit any kind of decision on the problem of determining whether there is an equal distribution of pollen associations among the sites. moreover, a classical inferential approach as manova (multivariate analysis of variance), apart from the very strong assumption of normality, is itself not allowed with a relatively small sample size as in our case (pesarin, 2002). on the contrary, the npc methodology frees the researcher from stringent assumptions of parametric methods and allows a more flexible analysis by specifying both multivariate and univariate hypotheses. one of the most relevant features of npc test is that it does not need a modelling for dependence among variables. pollen records have been subdivided into three groups, ca’ fornera (n° of records = 4), 23pollen data for a biostratigraphy ... fiorentina-latisana (n° of records = 4) and palazzetto (n° of records = 5). the considered pollen taxa are 20, but some of them have been joined and rare taxa and spore types have not been included. pairwise comparisons between groups of the relative frequencies of taxa have been performed with the aim of determining whether an equal distribution of pollen association is supported or not by our data set. the statistical analysis of pollen data does not also include pollen records from other sites (tab.1), as they are not entirely reported in literature: hence a successful comparison was not achievable. ssttaattiissttiiccaall aannaallyyssiiss ooff ppoolllleenn ddaattaa our statistical analysis starts with a descriptive overview of collected data. table 2 shows the mean and the standard deviation of the relative frequencies for all the pollen taxa included in our analysis; they are divided by site and also pooled for all sites. for the most important taxon, i.e. cyperaceae, we also provide a frequency graph (fig. 2), where an equal table 2 descriptive statistics for all considered taxa within each site. statistiche descrittive per i taxa analizzati in ogni sito. fig. 2 frequency distribution of cyperaceae on the three sites. distribuzione di frequenza delle cyperaceae nei tre siti. 24 distribution among sites could be possible. by means of a boxplot (fig. 3) we also provide a visual measure of the pooled distribution for the most relevant taxa or group of taxa, that are pinus undiff., cyperaceae, poaceae and hydrophytes. a simple descriptive analysis is only the first step of the work but we are not able to take a decision concerning a possible equal distribution of the relative frequencies of taxa among the sites. for this purpose we perform a npc test analysis, considering each single taxon and the global distribution of all taxa considered together. the npc test hypothesis system can be expressed in the following formal form, where a and b represent two sites, and xi represents the frequency of a given taxon (the i-th). the null hypothesis h0 states an equal global (multivariate) distribution between the two groups of all taxa (letter xx bold) considered together. the global null hypothesis is broken down into a set of k (20 in our study) partial null subhypotheses h0i which states an equal single (univariate) distribution for the i-th taxon between the two groups. for a detailed introduction and explanation of npc test methodology we refer to pesarin (2001). npc test solutions are provided by the new and innovative statistical software npc test 2.0 (more details at www.methodologica.it) that implements the npc methodology offering both flexibility and a user-friendly interface. as result of npc analysis (tab. 3), we obtain for each pairwise comparison a set of 20 pvalues concerning with each taxon and finally another one pvalue relating to the global null hypothesis. we should remember that a p-value less than the adopted significance α-level (in our case 5%, i.e. 0.05) means that there is a significant difference in the frequency distribution between the groups. ccoonncclluussiioonnss the npc test results confirm that there aren’t significant differences between peat sediments of the three groups if we look at their pollen associations (all global p-value are greater than 0.05). therefore we can support our hypothesis, that a plant community mostly consisting of cyperaceae and poaceae covered the entire area. some other herbaceous taxa were present, e.g. callitriche, caltha palustris, hydrocharis morsus-ranae, menyanthes trifoliata, lemna, myriophyllum verticillatum, nuphar luteum, potamogeton subg. p. type and many taxa of fungi, algae and mosses. studies for the identification of the latter and other plant fragments are in progress and they will lead to a finer characterization of the plant community. our results agree with the literature, in fact pollen analyses in tab. 1, showed dominance of herbaceous plant pollen, mostly of cyperaceae and poaceae, but little information about the other herbaceous plants. our research is continuing with pollen and fungi, algae and bryophytes microfossils analysis of lgm peats from other sites of the venetian plain in padova and near treviso. fig. 3 relative frequencies distribution of the most relevant taxa. distribuzione delle frequenze dei taxa più rilevanti.{h0: [pa = pb ] = [xxa d = xxb ] ⇒ {h0: [ k i =1 xai d = xbi ] = k i =1 h0i h1: [pa pb ] = [xxa d xxb ] h1: [ uu k i =1 xai d xbi ] = uu k i =1 h1i tab. 3 p-values table provided by npc test analysis. bold characters indicate values which are lower than the adopted significance α-level (0.05). tabella dei p-values ottenuta con l’analisi npc test. i numeri in grassetto indicano il valore di significatività inferiore allo 0,05. a. miola et al. uu uu 25 aacckknnoowwlleeddggeemmeennttss we would like to thank the anonymous referees for their comments and useful suggestions on a previous draft. rreeffeerreenncceess aa. vv. (1999) atti del convegno “le pianure. conoscenza e salvaguardia. il contributo delle scienze della terra”. ferrara, 8-11 novembre, 1999. accorsi c. a., bandini mazzanti m. & forlani l. (1984) spettri pollinici tardopleistocenici in sedimenti di pozzi nella pianura veronese. mem. mus. civ. st. nat. verona (ii serie), sez. sc. terra, 2, p. 35-63. accorsi c. a., bandini mazzanti m., forlani l., meneghel m., rigoni a. & sorbini l. (1989) primi dati stratigrafici e palinologici sulla sequenza di bernascone (verona), datata alla base 18.870± 300 b.p. infor. bot. ital., 21, p. 240-245. bertolani marchetti d. (1967) vicende climatiche e floristiche dell’ultimo glaciale e del postglaciale in sedimenti della laguna veneta. mem. biogeograf. adriatica, 7, p. 193-225. bondesan a., meneghel m., miola a. & valentini g. (2003) pollen analyses of lagoon and fluvial sediments of a 20 m core in the lower coastal river piave plain. palaeoenvironmental reconstruction from lgm to present. i l quaternario, 16, no. 1bis, p. 183-192. bondesan a., mozzi p. & calderoni g. (2002) l’assetto geomorfologico della pianura veneta centro-orientale, stato delle conoscenze e nuovi dati. scritti in ricordo di giovanna brunetta, dip. geografia dell’università di padova, p. 19-38. bortolami g. c., fontes j., markgraf v. & saliege j. f. (1977) land, sea and climate in the northern adriatic region during late pleistocene and holocene. palaeogeography, palaeoclimatology, palaeoecology, 21, p. 139-156. calderoni g., castiglioni g. b., foddai d., gallio s., hinterwipflinger v., lombardo m., miola a. & zangheri p. (1996) palaeoenvironmental features of a perieuganean (padua, n italy) depression during the late quaternary, f irst results. i l quaternario, 9, no. 2, p. 667-670. castiglioni g. b., girardi a. & rodolfi g. (1987) le tracce degli antichi percorsi del brenta per montà e arcella nei pressi di padova, studio geomorfologico. mem. scienze geologiche, 39, p. 129-149. castiglioni g. b. & pellegrini g. b. (eds.) (2001) note illustrative della carta geomorfologica della pianura padana. geogr. fis. dinam. quat. suppl. iv, 208 pp. goodwin h. (1981) the archives of the peat bogs. cambridge university press, cambridge, 229 pp. iliceto v., meloni f., mozzi p. & rizzetto f. (2001) il sottosuolo della cappella degli scrovegni a padova. geologia tecnica e ambientale, 4, p. 3-17. lezziero a. (1999) il sottosuolo di venezia, sedimentologia e paleoambienti. in: a.a. v.v., atti del convegno “le pianure. conoscenza e salvaguardia. il contributo delle scienze della terra”. ferrara, 8-11 novembre, 1999, p. 195-197. marocco r. (1989) evoluzione quaternaria della laguna di marano (friuli-venezia giulia). il quaternario, 2, no. 2, p. 125-137. miola a. & gallio s. (1997) primi dati palinologici sulla sequenza di galzignano del pleistocene superiore colli euganei (padova nord italia). in: accorsi c. a., bandini mazzanti m., labate d., trevisan grandi g. (eds.), “giornata di studi in ricordo di daria bertolani marchetti” (formigine, 18-5-96). deput. storia e patria. aedes muratoriana, modena, p. 415-420. mullenders w., favero v., ciremans m. & dirickx m. (1996) analyses polliniques de sondages a venise (ve-i, ve-i bis, ve-ii). in: gullentips f. (ed.) “pleistocene palynostratigraphy”, aardk. mededel., 7, p. 87-117. paganelli a. (1996a) a palynological study of forest vegetation in the veneto po plain. allionia, 34, p. 189-217. paganelli a. (1996b) evolution of vegetation and climate in the veneto po plain during the late-glacial and the early holocene using pollen–stratigraphic data. il quaternario, 9, no. 2, p. 581-590. paganelli a., miola a. & todaro a. (1988) ricerche palinologiche nel basso veneto. 1. biostratigrafia palinologica e dati radiometrici di alcuni depositi fluvio-lacustri. athesia, 2, p. 105-122. pesarin f. (2001) multivariate permutation tests with applications in biostatistics. wiley, chichester, 432 pp. pesarin f. (2002) extending conditional inferences to unconditional ones. journal of the italian statistical society, (in press). rizzi longo l. (1996) palynological evidence of the forest vegetation of the friuli plain, allionia, 34, p. 287-295. serandrei barbero r., lezziero a., albani a. & zoppi u. (2001) depositi tardo-pleistocenici ed olocenici nel sottosuolo veneziano, paleoambienti e cronologia. il quaternario, 14, no. 1, p. 9-22. ms. ricevuto il 6 novembre 2002 testo definitivo ricevuto il 25 marzo 2003 ms. received: november 6, 2002 final text received: march 25, 2003 pollen data for a biostratigraphy ... imp.bertini eeaarrllyy ttoo mmiiddddllee pplleeiissttoocceennee cchhaannggeess ooff tthhee iittaalliiaann fflloorraa aanndd vveeggeettaattiioonn iinn tthhee lliigghhtt ooff aa cchhrroonnoossttrraattiiggrraapphhiicc ffrraammeewwoorrkk aaddeellee bbeerrttiinnii department of earth sciences and museum of natural history, section of geology and paleontology, university of florence, via g. la pira 4, 50121 florence italy. abertini@geo.unifi.it abstract palynological data from selected pleistocene italian sites are presented. the chronostratigraphic framework of floral and vegetational events illustrates the development of cooler climates during the early and middle pleistocene. floral and vegetational response to glacial/interglacial cycles, as well as major floristic and vegetal replacements (e.g. taxodiaceae, cathaya, tsuga) are analysed with special attention to latitudinal and altitudinal gradients and to the different physiography of italy. the pollen flora shows marked changes both at the beginning of the pleistocene as well as at the time of the mid-pleistocene climate transition, when a major decrease in temperature, during steppe and forest phases, occurred. alternations of artemisia steppe and temperate to warm-temperate deciduous forest mark the overall glacial-interglacial vegetation changes in italy. glacials, however, do not correspond to dramatic drops of moisture in northern italy. cycles here are characterized by the alternating spread of deciduous broad-leaved forests and altitudinal coniferous forests (mainly picea) with no significant occurrence of steppe vegetation. several sites from northern, central and southern italy are described; reference sections permit correlations also of sites with poor time-diagnostic content. the quality of data is crucial in the application of advanced methodologies in palynology for reliable climate quantifications as well as for the elaboration of vegetation paleomaps. riassunto la palinologia rappresenta, potenzialmente, un importante strumento per la ricostruzione paleoambientale durante il pleistocene. durante questo intervallo di tempo la composizione floristica e la vegetazione sono ancora diverse da quelle presenti attualmente; un complesso melange di taxa aventi oggi una distribuzione geografica separata domina infatti le associazioni palinologiche. numerosi taxa, ancora presenti nel nostro paese (e.g. quercus, picea, abies), sono associati ad altri aventi invece una distribuzione asiatica e/o americana (e.g. taxodiaceae, cathaya, tsuga, carya). il progressivo fenomeno di raffreddamento, già cominciato durante il pliocene, determina la progressiva scomparsa dei taxa relativamente più termofili come ad esempio taxodiaceae, cathaya, parrotia persica, tsuga, cedrus e liquidambar. tali scomparse si verificano, nei diversi paesi europei e del litorale mediterraneo, in modo diacrono risultando fortemente influenzate da diversi gradienti climatici; la scomparsa delle taxodiacee, avviene in modo tempo-trasgressivo all’interno della stessa penisola italiana. tali eventi, possono, perciò, essere utilmente usati, solo se inseriti all’interno di un quadro cronostratigrafico di riferimento. la necessità di integrazione del record palinologico con altri strumenti stratigrafici è ribadita anche dal carattere spesso discontinuo di alcuni record così come dalla variabilità della vegetazionale locale. l’integrazione con elementi tempo-diagnostici quali la tefrostratigrafia o la magnetostratigrafia consente di inserire gli eventi ecobiostratigrafici in uno schema temporale; in tal modo essi diventano a loro volta elementi tempo-diagnostici in grado di migliorare la risoluzione stratigrafica; cio’ rende possibile anche un loro corretto utilizzo per la definizione e la caratterizzazione di unità climatostratigrafiche e di biozone. in tal modo la palinologia diventa uno strumento efficace ed indispensabile per le ricostruzioni stratigrafiche e paleoambientali. le diverse successioni italiane analizzate in questo lavoro di sintesi sono state selezionate sulla base della qualità del dato pollinico e della presenza di un adeguato quadro cronostratigrafico di riferimento. ciò ha consentito di tracciare, in accordo con i cambiamenti relativi alla latitudine, altitudine e alle diverse caratteristiche fiosiografiche dei siti analizzati, la risposta della flora e della vegetazione ai cicli glaciale/interglaciale (g/i) durante il pleistocene inferiore e medio. la palinoflora, già depauperata all’inizio del pleistocene, subisce un progressivo ulteriore impoverimento in corrispondenza della transizione climatica del pleistocene medio quando un’importante diminuizione della temperatura marca sia le fasi forestali che steppiche. in italia, i cicli g/i determinano, generalmente, un’alternanza tra una vegetazione di tipo aperto prevalentemente steppica (ad artemisia) sotto un clima arido da fresco a freddo ed una forestale dominata dalle latifoglie decidue sotto un clima umido e caldo-temperato. tuttavia, nessuna importante diminuizione dell’umidità con conseguente espansione della vegetazione steppica è stata registrata durante i glaciali, nei siti dell’italia settentrionale; qui, infatti, i cicli g/i sono caratterizzati dalla contrapposizione tra foreste di conifere di altitudine (principalmente a picea) e foreste di latifoglie decidue. l’analisi floristica e vegetazionale delle diverse successioni analizzate evidenzia la buona potenzialità di alcune di loro a costituire delle sezioni di riferimento rappresentative delle diverse aree chiave della nostra penisola (nord, centro, sud). la definizione e la calibrazione dei principali eventi floristici e vegetazionali facilita le correlazioni sia a piccola con sezioni geograficamente vicine a quelle di riferimento, non provviste di nessun altro supporto cronologico – che a grande scala. i dati selezionati potranno essere efficacemente utilizzati nell’ambito delle quantificazioni climatiche e per la ricostruzione di paleomappe di vegetazione; entrambi questi approcci sono già stati applicati con successo a siti neogenici. key words: pollen, flora, vegetation, climate, early-middle pleistocene, italy. parole chiave: polline, flora, vegetazione, clima, pleistocene inferiore e medio, italia. il quaternario italian journal of quaternary sciences 1166(1bis), 2003, 19-36 11.. iinnttrroodduuccttiioonn pollen represents, potentially, an important mean for the reconstruction of the patterns and processes of vegetation and climatic changes during the pleistocene. at this time, the floral composition and vegetation of the mediterranean and central european areas were still quite different from those present today; new species seldom appear and the disappearance of some thermophilous taxa (e.g. taxodiaceae, parrotia persica, cedrus, liquidambar) has a diachronous character (e.g. zagwijn, 1975; suc, 1986; combourieu-nebout, 1987; fusco, 1996). the palynologic content must thus be used warily in describing biozones or climatostratigraphic units, especially when they do not make part of an established chronostratigraphic framework. several 20 a. bertini palynostratigraphic correlations made in the past (e.g. those based on the disappearance of taxodiaceae interpreted as an isochronous event; lona et al., 1969; lona & bertoldi, 1972) are incorrect (e.g. zagwijn, 1975; bertolani-marchetti et al., 1979; michaux et al., 1979) because based on two hazardous assumptions: the belief that the same (or similar) pollen assemblage zones in separate sections denote synchronous pollen signals; and the subsequent chronostratigraphic significance (e.g. tiberian phase and boundary; lona et al., 1969; lona & bertoldi, 1972) attributed to some of these “ecobiostratigraphic” phases. this blurred the boundary between biostratigraphy and chronostratigraphy. because of local vegetational variability and of the scantiness of many records (notably that from continental areas) palynology needs to be associated to other stratigraphic tools. in fact, the integration of time-diagnostic evidence (e.g. magnetostratigraphy and tephrostratigraphy) gives chronological value to ecobiostratigraphic events, thus enhancing stratigraphic resolution. hence, correlation at local to regional scale between the successions lacking time-diagnostic elements is also made possible. moreover, contrary to other fossils, palynomorphs, being contained in both marine and non-marine sediments, permit the correlation between onshore and offshore successions. all this makes palynology a very powerful tool for stratigraphic and palaeoenvironmental reconstructions. these observations justified the selection of the lower to middle pleistocene successions of italy discussed in the paper (figs. 1-2). the responses of the flora and vegetation to the glacial/interglacial cycles with special attention to latitudinal and altitudinal gradients are analysed, together with the major vegetation replacements. 22.. ssttrraattiiggrraapphhiiccaall sseettttiinngg the neogene regional and global events (e.g. messinian salinity crisis, early pliocene transgression, late pliocene expansion of the arctic ice cap and consequent start of glacial/interglacial cycles), strongly affected the successive pleistocene history of the mediterranean settings. from about 2.6 to 0.9 ma, the glacial/interglacial fluctuations (g/i cycles) were dominated by orbital obliquity cycles, which have a periodicity of 41 ka; fluctuations of 100 ka, related to orbital eccentricity cycles, prevailed thereafter (ruddiman et al., 1989). this shift toward a more extended periodicity and amplitude indicates more intense glacial conditions, particularly between ca 0.9 and 0.6 ma. in land settings, this modification in the g/i cycles produced a significant change in the vegetation and flora: steppes spread, while extreme thermophilous taxa, especially those distributed in subtropical areas today, progressively demised. the important geomorphic changes linked to the uplift of the apennines also produced an important reorganization and restructuring of vegetation. increased elevation led to climatic conditions similar to those found at higher latitudes; this also gave rise to diffig. 1 location map of the selected sections 21early to middle pleistocene changes ... f ig .2 s tr at ig ra ph ic al lo ca tio n of th e se le ct ed s ec tio ns 22 a. bertini ferent belts of vegetation at different altitudes. all these modifications in climate and vegetation inexorably affected large mammal assemblages as well. in fact, important turnovers are detected in the villafranchian mammal faunal communities (e.g. torre et al., 2001; fig. 2). a strong drop in ruminant diversity, as well as the arrival of social carnivores, mark the end of the reunion subchron and the onset of the olduvai subchron (azzaroli et al., 1988). this is known as the “wolf-event” (azzaroli, 1983; 1995; rook & torre, 1996). another change in the villafranchian faunal community, marked by the arrival of mammuthus (archidiskodon) and equus, and known as the “elephant-equus event”, had occurred shortly before, approximately at the gauss/matuyama transition (azzaroli, 1995; torre et al., 2001). the low ruminant diversity persisted until the middle pleistocene, when it grew again, equalling the final pliocene levels, thanks to the arrival of new incomers. the successions analysed in this work are mostly located in the pre-alps and in the apennines (fig. 1). the schematic stratigraphic position of these sites are shown in figure 2. the triassic to paleogene marine successions exposed in the southern alps were involved in the final miocene pulses of the alpine deformation which caused the emergence of most of this area. several valleys in the pre-alps, which had formed before the end of the messinian (bini et al., 1978), were filled with pliocene marine sediments (bini et al., 1978; brambilla et al., 1983; brambilla & lualdi, 1987; violanti, 1991). during the plio-pleistocene, the upper lombardy plain emerged. fluvial sediments deposited during a successive phase of aggradation. tributary valleys finally dammed at the end of the aggradation phase, and lacustrine basins were formed, as for example those of leffe (cremaschi & ravazzi, 1995) and fornaci di ranica (ravazzi et al., in press). several terraced deposits were formed during the successive middle and late pleistocene fluvial downcut. the apennines started to arise in the latest cretaceous, during the eo-alpine phase. from the late tortonian to the early middle pleistocene, extensional faulting affected the inner sectors of the apennine chain, generating numerous, relatively small, eastward-progressing and younger, marine and continental basins, extended wsw of the orographic divide. three major successions of marine to continental deposits characterize the peri-tyrrhenian extensional areas (an outline can be found in ghisetti & vezzani, 1999). martini & sagri (1993), and bossio et al. (1998) described the successions outcropping in the northern apennines, while cinque et al. (1993) the ones exposed in the southern apennines. compressional basins (“piggyback” and “foredeep” basins; ori & friend, 1984; riccilucchi, 1986; 1990) formed on the adriatic side of the mountain divide. 33.. mmaatteerriiaallss aanndd mmeetthhooddss the pleistocene sections selected for this study (figs. 1, 2) are among the most dependable from the chronological viewpoint. the main stratigraphical and geological information is summarized below, whereas the pollen records are discussed in the following paragraphs. 11. the ssttiirroonnee succession outcrops on the banks of the stirone river, along the northern apennine foothills, some 28 km west of parma (northern italy). because of its rich stratigraphical and paleontological documentation, it is one of the best known pliocene to pleistocene successions of northern italy (e.g. papani & pelosio, 1963; pelosio & raffi, 1974; raffi, 1982; iaccarino & pugliese, 1988; capotondi, 1992; mary et al., 1993; channel et al., 1994; monegatti & pelosio, 1994; iaccarino, 1996). the stirone succession consists, from the base upwards, of about 900 m of lower to upper pliocene marine deposits and of over 100 m of pleistocene infralittoral sediments, with intercalations of brackish and fresh water beds. the palynological content of the pliocene sediments was analysed by bertini (1992; 1994a, b; 2001) and bertini & vannucchi (1993), whereas that of the upper pliocene to lower pleistocene sediments by lona & bertoldi (1972), becker-platen et al. (1977) and bertolani-marchetti et al. (1979). 22. the uuppppeerr vvaallddaarrnnoo (central italy) is one of the most extensive plio-pleistocene intermontane basins of the northern apennines. it is located 35 km se of florence between the chianti mountains and the pratomagno ridge. it is filled with some 550 m of fluviolacustrine deposits which can be divided into three main sedimentary successions (e.g. merla & abbate, 1967; azzaroli & lazzeri, 1977; abbate, 1983; magi & sagri, 1994) of middle pliocene to pleistocene age on the basis of bioand magnetochronological evidence (torre et al., 1993, 1996; albianelli et al., 1997; napoleone et al., this volume). pollen analyses were carried out by bertini (1994b; in press), bertini & roiron (1997) and mazza et al. (submitted). 33. the sseemmaaffoorroo--vvrriiccaa composite section outcrops 4 km south of crotone (calabria, southern italy). it consists of about 451 m of pliocene and pleistocene marine blue grey silty-marly claystones with sapropelic laminite and cineritic intercalations. at vrica, the base of the marine claystones, which conformably overlies the sapropelic marker bed "e", marks the onset of the pleistocene series (aguirre & pasini, 1985; basset, 1985; van couvering, 1997). palynological analyses were carried out by bertolani-marchetti (in selli et al., 1977), nakagawa et al. (1980; 1997), combourieunebout & vergnaud-grazzini (1991), and combourieunebout (e.g. 1993; 1995). 44. the marine plio-pleistocene section of ggeellaa, in sicily (agrigento, southern italy), is well known in literature thanks to the studies of rio et al. (1984) and sprovieri et al. (1986). palynological studies there were carried out by bertoldi et al. (1989). 55.. llee ccaasstteellllaa is a marine section located on the ionian side of northern calabria (crotone basin). it was first described by emiliani et al. (1961). calcareous nannofossil biostratigraphy (raffi & rio, 1980) revealed a fairly long hiatus at the sandy “marker bed” of emiliani et al. (1961). pollen records are available from the upper part of the late pliocene, as well as from the middle part of early pleistocene (bertoldi, 1977; bertoldi et al., 1989). 66.. the ccaammeerroottaa basin, in the cilento promontory, is a structural depression formed during the late pliocene extensional tectonics that disrupted the eastern margin of the southern tyrrhenian basin (borrelli et al., 1988). here palynological research was 23early to middle pleistocene changes ... performed in sediments of an about 40-50 m thick lacustrine succession of clays and marls with recurrent tephra and peat beds in the upper portion (baggioni et al., 1981; brenac, 1984; russo-ermoll i , 1999). unfortunately, these deposits are void of significant time-diagnostic elements. the only sure stratigraphical reference are santernian marine deposits which unconformably cap the sequence. 77. the lleeffffee section, in the lombardian pre-alps, consists of a plio-pleistocene continental succession of clays, brown-coals, peats, gyttja, and biogenic calcareous laminites. more precisely, the succession extends between the top of the olduvai (muttoni, in progress, and ravazzi, pers. com. 2002, claim that it possibly reaches the base of the olduvai) and the base of the jaramillo (which however was never located). the palynologic content of this sequence was studied by lona (1950), lona & follieri (1957), lona & bertoldi (1972), ravazzi (1993: see for geological and stratigraphical references), ravazzi & rossignol-strick (1994; 1995), ravazzi & moscariello (1998) and pini & ravazzi (2002). 88. the llaammoonnee succession, in the north-eastern apennines, consists of marine grey-blue clays of the argille azzurre fm. this succession is santernian to emilian in age, on the basis of its foraminiferal content (vaiani, 1996). palynological studies have been carried out in two separate sections (fusco, 1996). the first one contains the santernian/emilian boundary, marked by the appearance of the benthonic foraminifer hyalinea baltica (pasini & colalongo, 1994). this same taxon is distributed throughout the whole second section, which therefore is dated to the emilian. 99. the ppiieettrraaffiittttaa lacustrine succession outcrops in the tavernelle basin, which forms the upper valley of the nestore river (umbria, central italy). the succession consists of clays, peaty clays and lignite beds. the latter have yielded numerous fossil remains of vertebrates, invertebrates, and macroflora. the mammal remains have been referred to the farneto faunal unit (late villafranchian mammal age; gliozzi et al., 1997). an early pleistocene age is also consistent with the inverse magnetic polarity detected in the l ignite beds (napoleone & albianelli, pers. com. 2002). ricciardi (1961) and lona & bertoldi (1972) carried out the palynological analyses of this succession. 1100.. mmoonnttaallbbaannoo iioonniiccoo, southernmost part of the bradano trough (basilicata, southern italy). this marine succession consists of about 400 m of silty clays (“argille subappenine” formation), with nine volcanoclastic intercalations. the succession was found to straddle the lower-middle pleistocene boundary on the basis of nannofossil and magnetostratigraphic evidence (e.g. ciaranfi et al., 1996; 2001). preliminary palynological analyses were performed by suc (suc, pers. com. 1999). 1111. the mmoonnttee ssaann ggiioorrggiioo succession, north of caltagirone (sicily), consists of 150 m of marine clayey and sandy marls intercalated to clays. palynological analyses were carried out along a 60 m section where the continental and marine records indicated a dating from 1.23 to 1.095 ma (dubois, 2001). 1122.. ssaannttaarrccaannggeelloo is a pliocene to pleistocene satellite basin in the southern apennines (basilicata, southern italy). palynological research has been carried out in the lacustrine deposits of the san lorenzo unit (bertini in sabato et al., in press; bertini, in progress). the latter is an over 200 m thinly bedded claystone and silty claystone with sandstone, carbonate and volcanoclastic intercalations. a late biharian mammal assemblage was found in this succession (masini et al., in press). palaeomagnetic investigations allow the identification of the jaramillo subchron, as well as the base of the brunhes chron (sabato et al., in press). 1133. the ccoollllee ccuurrttii and cceessii fluvio-lacustrine basins are located in the umbria-marchean apennine mountains (central italy), at about 850 m and 820 m above sea level, respectively. they were formed in the early to middle pleistocene when extensional tectonics affected the mountain chain (e.g. coltorti et al., 1998). the colle curti mammalian faunal assemblage defines the homonymous faunal unit, which marks the beginning of the galerian mammal age in italy (e.g. ficcarelli et al., 1997). magnetostratigraphical research identified the c1r.2r p.p., c1r.1n (jaramillo), c1r.1r and c1n p.p. (brunhes) chrons and subchrons. pyroclastic sediments about 30 m above the top of the section, yielded an ar/ar date of 424 ka (coltorti et al., 1998). the palynological content of both sections was studied (e.g. bertini, 2000). 1144. the lacustrine succession of ffoorrnnaaccii ddii rraanniiccaa, at the outlet of the seriana valley in the bergamo foothills (northern italy). multidisciplinary studies carried out throughout a 13 m long-core suggest that the sedimentation occurred in the late early pleistocene, apparently during the jaramillo subchron. nevertheless, the impossibility to discriminate between cervalces latifrons and c. carnutorum do not exclude a correlation to the cryptochron cobb (ravazzi et al., in press). 1155. the vvaallllee ddii mmaanncchhee section, south-east of the san mauro marchesato area, in the crotone basin (southern italy). here the middle pleistocene deposits underwent detailed stratigraphical studies (see in massari et al., 2001 for references). the valle di manche section contains the three main units defined in the san mauro group (san mauro 1, 2, 3) extending approximately just above the top of the jaramillo and the “parmenide ash” key bed. the brunhes matuyama boundary correlates with the“pitagora ash”, in the mainly muddy san mauro 2 unit. capraro in massari et al. (2001) performed palynological analyses from the base to the lower part of s. mauro 3, which mainly consists of prograding sand bodies. 1166.. llaa ppiinneettaa - iisseerrnniiaa. the archaeological site of la pineta lies at about 450 m a.s.l in the intermontane isernia–venafro lacustrine basin, in the upper part of the volturno valley (southern italy). the basin was filled up between 870 ±150 and 520 ±50 ka ago (van otterloo & sevink, 1983). five units have been recognized (cremaschi, 1983; cremaschi & peretto, 1988), with a lacustrine episode at the base. the latter is overlain by a fluvial unit containing mammal remains and lower paleolithic lithic industry. delitalia et al. (1983) obtained a k/ar dating of 736 ±40 ka (for the archaeological bed). such a dating, however, was first challenged by von koenigswald & kolfschoten (1996) because of the occurrence of arvicola cantiana, and afterwards by belluomini et al. (1997) who obtained an amino-acid dating of 550 ±140 ka. pollen analyses were carried out by lebreton (2001; 2002). 1177.. ppiiaanniiccoo--sseelllleerree, south of the italian alps, consists of an about 50 m varved lacustrine succession 24 (moscariello et al., 2000). the k/ar dating of a distal tephra in the sequence gave an age of 779 ± 13 ka. palaeomagnetic analyses consistently detected the matuyama/brunhes transition. the latter is dated 780 ka (pinti et al., 2001) and correlates both with the marine oxygen isotopic stage 19 (mis 19) and with the oldest interglacial phases of the cromerian complex of central europe (e.g. turner, 1996). 1188.. vvaalllloo ddii ddiiaannoo is a large tectonic basin in the campanian apennines (southern italy). here a borehole about 150 m deep was drilled through a lacustrine sequence. a 601 ± 7 ka 40ar/39ar dating at the base of the sequence, matched with oxygen isotopic data, suggested that the pollen record (e.g. russo-ermolli, 1994; russoermolli et al., 1995) covers a 650 to ca 450 ka span (mis 16 to 13) (e.g. russo-ermolli & chedaddi, 1997). 1199.. tthhee aacceerrnnoo bbaassiinn (southern italy) represents a middle pleistocene tectonic paleolake formed in the southern apennines. a 98 m continuous coring drilled through a sequence consisting, from the base upwards, of fluvial conglomerates, silt and white marl alternations, and fluvial conglomerates with silt and sand interfingings. thirty pyroclastic beds were identified. the thickest tephra bed correlates with mis 9 and 8 because of the presence of the lower white trachytic tuff marker horizon dated to 297 ka (munno et al., 2001). pollen analyses of this sequence were carried out by elda russo-ermolli (2000). 44.. tthhee eeaarrllyy pplleeiissttoocceennee the marine composite section of sseemmaaffoorroo--vvrriiccaa (crotone, calabria) is used as reference to locate stratigraphically the main late pliocene to early pleistocene floral, vegetational and climatic changes. in the vrica section, in particular, the gssp of the base of the pleistocene series has been ratified, whereas the calabrian stage as well as the emilian and santernian substages have only been proposed (aguirre & pasini, 1985; basset, 1985; pasini & colalongo, 1994; ruggieri & sprovieri, 1997; pasini & colalongo, 2001). successive studies (e.g. hilgen, 1991; zijderveld et al., 1991; lourens et al., 1966a,b; 1998; raffi, 2002) provided further stratigraphic evidence completing the original definitions. zijderveld et al. (1991) repositioned the plio-pleistocene boundary (ppb) placing it just below the top of the olduvai subchron. lourens et al. (1996a) showed that the pleistocene part of the vrica section ranges from the standard oxygen isotope stage 65 to 36, stressing the substantial difference from previous interpretations (combourieu-nebout & vergnaudgrazzini, 1991; sprovieri, 1993). in contrast to oceanic sequences, the base of the large gephyrocapsa (blg) zone correlates with stage 55 and not with stage 48 (or with the top of stage 49) (raffi et al., 1993; lourens et al., 1998; raffi, 2002). consequently, the fad of the benthic foraminifer hyalina baltica does not match with the base of the large gephyrocapsa zone. by carrying out the most detailed and accurate palynological studies of the plio-pleistocene composite sections of southern italy, combourieu-nebout (e.g. 1993; 1995) reconstructed the changes in vegetation and climate during the 2.46 to 1.36 ma time span. the main vegetation changes were shown to closely match global climatic variations (e.g. combourieu-nebout & vergnaud–grazzini, 1991). forest to open herbaceous vegetation fluctuations, which reflect the climatic oscillations linked to glacial/interglacial cycles, are documented from the base of the semaforo section (ca at 2.46 ma). likewise other mediterranean sites (see references in suc et al., 1995), the succession of four main vegetational assemblages attests to a gradual transition from warm and moist (interglacials) to cold and dry (glacials) conditions. the start of an interglacial event is marked, at first, by the expansion of deciduous forests, and then, by that of subtropical moist forests indicating an increase in temperature followed by an increase of the humidity. subtropical moist forests progressively reduced from the late pliocene on. the successive increase of high-altitude coniferous forest taxa indicates a temperature drop but no marked variations in humidity. finally, the considerable spread of open vegetation with artemisia indicates a substantial decrease in humidity. g/i cycles are marked by four following vegetation units in northern italy as well. this is clearly documented in the marine succession of llaammoonnee (north-eastern apennines; fusco, 1996), which is more or less equivalent in time to the vrica section. cycles, though, differ from those described at vrica (e.g. combourieu-nebout, 1993) because of the lesser expansion of herbs (especially artemisia) and wider spread of picea. the diffusion of montane arboreal vegetation, in particular picea, during glacial phases, as well as the limited expansion of the herbaceous vegetation, both in time and space is attested to in several plio-pleistocene marine and continental deposits of northern italy (leffe: lona, 1950; ravazzi & rossignol-strick, 1995; castell’arquato: lona, 1962; lona & bertoldi, 1972; stirone, pliopleistocene portion: lona & bertoldi, 1972; bertolanimarchetti et al., 1979; pliocene portion: bertini, 2001; marecchia valley: rio et al., 1997). a phase characterized by high percentages of artemisia but associated to picea and larix, is recorded from the upper part of the early pleistocene continental succession of lleeffffee (lombardy pre-alps) (ravazzi & rossignol-strick, 1995). the limited expansion of steppe taxa seems due to local climatic constraints existing at the time in northern italy, more than to the apparent result of some taphonomic bias, or insufficient chronologic resolution. this strengthens the hypothesis that, roughly since the pliocene, the po region had a very peculiar vegetation and climate (bertini, 2001; fauquette & bertini, in press). plio-pleistocene glacial-interglacial cycles of continental intermontane sequences of central italy have intermediate characteristics between those of southern and northern italy. typical examples are those of the uuppppeerr vvaallddaarrnnoo (e.g. bertini, 1994b; albianelli et al., 1995; torre et al., 1996; albianelli et al., 1997; bertini, in press), the tiber basin (pontini, 1997; pontini & bertini, 2000; pontini et al., 2002), and ppiieettrraaffiittttaa (lona & bertoldi, 1972). on the basis of palynological, biostratigraphical and isotopical evidence from southern italy, bertoldi et al. (1989) observed a different response of vegetation to g/i cycling. in the upper pliocene to lower pleistocene sites of llee ccaasstteellllaa and ggeellaa, in particular, these authors proposed that glacials are marked by forests, while interglacials by open vegetation. a. bertini in the light of the information presented above, it is apparent that repeated g/i cycles contributed to the compositional and structural changes in the vegetation. the upper pliocene of vrica is particularly enlightening. a significant demise of the taxodiaceae forests is attested to from about 2.38 ma on, followed by a spread of cathaya, especially from ca 1.92 to 1.74 ma, as well as of artemisia, from ca 1.87 ma on. in the course of the same interval, warm temperate woodlands expanded at the expense of subtropical forests. the same occured in the upper valdarno, but the record in this case is rather less continuous (bertini, 1994b; bertini, in press). the distribution of taxodiaceae in space and time, as well as their stratigraphical implications during the upper pliocene to early pleistocene time span, are analysed in more detail in paragraph 6.1. the arrival of the large gephyrocapsa, at about 1.56 ma, and successively of hyalina baltica at the santernian-emilian boundary about 1.49 ma, characterizes the marine realm. on lands, a general expansion of open vegetation at this time, in particular of steppe taxa, such as artemisia, a taxon indicative of dry conditions, is recorded at vrica. here, roughly after 1.47 ma (i.e. above laminite q), altitude trees reach their highest percentages, tsuga replacing cathaya in forest associations. this indicates cooler but relatively moist conditions. at lamone (fusco, 1996), in northern italy, a similar trend is observed near to the occurrence of hyalina baltica. a well marked cyclic expansion and dynamism of different vegetations can also be observed. a similar evolution is documented at stirone (lona & bertoldi, 1972; bertolani-marchetti et al., 1979) and leffe (ravazzi & rossignool-strick, 1995). in the latter, in particular, high resolution pollen analyses recently permitted the identification of eleven cyclic changes in vegetation and climate (pini & ravazzi, 2002; in progress) from the end of the late pliocene to the early pleistocene, just before the jaramillo subchron. palynological evidence stops at about 1.36 ma at vrica. additional information from 1.23 and 1.095 ma (the lower part of the sicilian) is available at mmoonnttee ssaann ggiioorrggiioo (caltagirone, sicily). here, glacial/interglacial cycles recall those detected at vrica, with only minor differences (dubois, 2001). 55.. tthhee llaattee eeaarrllyy aanndd mmiiddddllee pplleeiissttoocceennee the most complete late early and middle pleistocene marine and continental successions outcrop in southern italy. the marine successions permit the formal definition of standard pleistocene chronostratigraphic units. the mmoonnttaallbbaannoo jjoonniiccoo section (basil icata, southern italy), with its f irst occurrence of gephyrocapsa sp. 3 near the top of the jaramillo subchron and in correlation with oxygen isotopic stage 25 (ciaranfi et al., 2001), was the proposed gssp (global boundary stratotype section and point) of the middle pleistocene. it is an alternative to the japanese section of boso peninsula, where kumai’s (1996) proposed gssp lies in the proximity to the brunhesmatuyama magnetic reversal. unfortunately, a pilot survey revealed that the uppermost part of the analysed samples from montalbano jonico section are barren in sporomorphs (suc, pers. com. 1999). instead, pleistocene continental deposits (san lorenzo cycle) from the neighbouring ssaannttaarrccaannggeelloo basin offer a rich palynological documentation (bertini in sabato et al., in press). here the pollen record evidenced repeated alternations of open landscapes, dominated by steppe taxa such as artemisia and ephedra, and forests (mostly quercus) throughout the late early pleistocene. detailed palynological analyses of the upper part of the succession are in progress. the palynological analysis of both the santarcangelo and montalbano jonico sections are expected to permit marine-continental correlations during a key moment of the pleistocene. preliminary pollen data (capraro in massari et al., 2001) from the marine vvaallllee ddii mmaanncchhee section, about 150 km south of montalbano jonico, in the crotone area, are in agreement with those from santarcangelo. in central italy, the main changes in the palaeoflora and vegetation detected in the ccoollllee ccuurrttii and cceessii fluvio-lacustrine deposits (bertini, 2000), occurred between 0.9 and 0.6-0.7 ma (ficcarelli et al., 1997; coltorti et al., 1998), which is approximately the same time span covered by the santarcangelo record. the two successions reveal a progressive increase in aridity, as well as a progressive decrease in temperature, which is associated to the middle pleistocene shift from the 41 to 100 ka cyclicity in the milankovitch orbital record (bertini, 2000). during the successive open vegetation phases (glacials), chenopodiaceae and artemisia progressively increase, whereas cyperaceae decline. forest phases are first dominated by tsuga, then by abies plus picea and, finally, pinus; but these forests show no significant expansion of broad-leaved deciduous elements. palynological, sedimentological, and taphonomic evidence reveal the occurrence of several hiatuses in the early parts of the interglacials. these hiatuses were considered the palaeoenvironmental response to climatic changes affecting local lithological and geomorphological settings (karst) (bertini, 2000). the same trend observed at colle curti and cesi for tsuga, with peak of abundance during the jaramillo subchron, was also observed at ffoorrnnaaccii ddii rraanniiccaa (ravazzi et al., in press), in northern italy. at c. curti, tsuga reaches another peak, before its final decline, in the post-jaramillo inverse polarity interval. in the ppiiaanniiccoo--sseelllleerree continental succession, near fornaci di ranica, tsuga, as well as pterocarya, carya, and cedrus, are lacking at about 779 ± 13 ka, which is the date of a tephra included in the middle part of the succession (pinti et al., 2001). a much younger age, correlative with mis 5, 7 or 9, was previously suggested for this succession, on the basis of the geological setting and macroflora studies (moscariello et al., 2000). the previously mentioned climatic gradients, which characterized the mediterranean area at least since the neogene, account for the major expansion of herbs and reduced presence of relatively moister arboreal taxa in southern sites than in northern ones. tsuga is less abundant in the south, as testified by the pollen records from monte san giorgio, santarcangelo and llaa ppiinneettaa (isernia) which, taken as a whole, extend in time from the upper part of the early pleistocene to the beginning of the middle pleistocene. the available pollen data (suc & bessais, 1990; bertini et al., 1998) 25early to middle pleistocene changes ... shows that ever since the neogene this taxon has never been an important element of the forests at the latitude of sicily. at vvaalllloo ddii ddiiaannoo (southern italy) tsuga is virtually absent from 650 to 450 ka, whereas carya is constantly present, and pterocarya is sporadic. two main climatic oscillations were recognized and correlated with the glacial–interglacial cycles mis 16 to 13. as at santarcangelo the glacial intervals are characterized by high concentrations of herbaceous and steppe pollen, while the interglacial intervals are dominated by arboreal pollen. the lacustrine succession of aacceerrnnoo, southern italy, was correlated with isotopic stages 9 and 8 because of the presence of the lower white trachytic tuff (wtt) marker horizon which is dated 297 ka (munno et al., 2001). pollen analyses confirmed an interglacial-glacial cycle. interglacial conditions are indicated by a phase of oak forest expansion, while glacial conditions are marked by a sharp drop in all arboreal taxa, as well as by the simultaneous spread of herbaceous and steppe elements. here tsuga and carya are absent. 66.. ddiissccuussssiioonn the selected pollen data contribute substantially to the reconstruction of the lower and middle pleistocene landscapes in italy because they permit a direct comparison of the main palaeonvironmental (e.g. climatic and tectonic) events, at both global and local scale, with significant floristic and vegetation changes. they also address some key stratigraphic questions relevant to this time interval. 6.1. the ppb, the tiberian boundary, and the pliopleistocene range of taxodiaceae the ppb, located at the base of the marls overlying sapropel marker bed ‘e’ in the vrica section, corresponds to the beginning of a glacial period, as attested to by the spread of herbaceous and steppe vegetation after a long period of relatively homogenous, warm conditions (interglacial) (e.g. combourieu-nebout et al., 1990). in the semaforo-vrica composite section, on the other hand, the glacial-interglacial cycling starts 350 m below marker bed “e” (e.g. combourieu-nebout, 1995). therefore this event is not an unequivocal climatic signal. g/i cycles seem to set off limited change in the composition of flora associations after 2.46 ma. they must therefore be distinct. artemisia progressively gained importance in the open vegetation communities of glacial intervals, whereas warm-temperate taxa prevailed on subtropical taxa, which progressively disappeared, in forest associations during interglacials. continental sites lack most of the stratigraphical information available in marine settings. therefore, the glacial event near marker bed “e” at vrica may be a useful reference for identifying the ppb only when it is associated to the palaeomagnetic record. in fact, in the fluviolacustrine uuppppeerr vvaallddaarrnnoo basin (central italy), the recognition of the split olduvai (zijderveld et al., 1991) permitted the same resolution of marine sediments in calibrating the pollen assemblage zones to climate zonation, as well as in correlating mammal fauna biochronology with marine biostratigraphy (albianelli et al., 2002). the changes in vegetation, in particular, closely matched the climatic fluctuations, which were recorded by oxygen isotopic stages. in particular, near the ppb, an 89 % peak of herbs (glacial) follows a warm-and humid phase dominated by forest taxa (interglacial). in the past, some italian palynologists placed the ppb in correspondence to the disappearance (or better the dramatic fall) of taxodiaceae. lona et al. (1969; 1971) observed the sudden disappearance of taxodium pollen just after an acme phase in the lacustrine ppiieettrraaffiittttaa succession and called this event the “ tiberian boundary”. later on, the tiberian boundary was also recognized in the marine section of stirone about 10 meters below the level where papani & pelosio (1963) found arctica islandica (and where the ppb was placed). lona et al. (1969) and lona & bertoldi (1972) correlated this event with the beginning of the calabrian and with the ppb, pointing out the delay in the appearance of the northern marine guests. in 1977 the recovery of a. islandica specimens (pelosio & raffi, 1977) at the top of the “calcarenite” of the stirone section permitted a repositioning of the ppb. iaccarino (1996) argued that the plio-pleistocene transition occurs about 3 m below the base of the “calcarenite”, in correspondence to a downward-shift (mutti pers. com. in capotondi, 1992). these new data cleared the discrepancy between the arrival of the northern marine guests and the disappearance of the taxodiaceae, and confirmed the position of the tiberian boundary (and of the ppb). bertoldi (1977) recognized the tiberian boundary at the marker bed in the marine section of le castella. in the upper valdarno, a strong decrease in taxodium type pollen after an acme phase was observed close to the ppb (bertini, in press), as well as in pietrafitta and stirone. nevertheless, it is important to stress that the recurrence of the episodes of sudden fall in the pollen percentage of taxodiaceae during the upper part of the late pliocene does not make these events an unequivocal signal. moreover, taxodiaceae survive the ppb in many italian sites (e.g. bucha et al., 1975; bertolanimarchetti et al., 1979; fusco, 1996; ravazzi & rossignol-strick, 1995; combourieu-nebout, 1993; 1995; bertini, 2001). this prevents an exact location of this limit, especially in short and discontinuous successions without the support of marine stratigraphy or timediagnostic elements; the latter remark was also made by lona & bertoldi (1972). the climatic requirements and geographic distribution of some extant taxodiaceae, which are shown in table i, can explain why different components of this family disappeared during the late pliocene and pleistocene in the mediterranean area (see also the interpretations of lona, 1963; lona et al., 1971; lona & bertoldi, 1972; bertolani-marchetti, 1978). in the italian pollen record, taxodiaceae are mainly represented by sciadopitys, taxodium type (which includes taxodium cf. distichium and glyptostrobus) and sequoia type (which includes sequoiadendron giganteum, sequoia sempervirens, metasequoia, cunninghamia and cryptomeria). both taxodium type and sequoia type include different genera with similar pollen morphology which prevents their specifical identification at the optical microscope. taxodiaceae were among the most important components of the zanclean and early 26 a. bertini piacenzian thermophilous forests. starting from the late piacenzian, and especially during the gelasian, after the start of g/i cycles, taxodiaceae considerably declined. the analysis of the sections selected permit the tracking of their spatial and temporal distribution in italy during the late pliocene and pleistocene (fig. 3). in the stirone and lamone successions, taxodium type is quite well represented, whereas sequoia type is scattered. at lamone, the former reaches 11.2 % in abundance in the santernian, and 4.6 % in the emilian. aside from leffe, taxodium type is absent during the emilian; it occurs at low percentages only in the lower part of cycle m, which was correlated with isotopic stages 51/50 or 53/52 by ravazzi & rossignol-strick (1995). at pietrafitta, as mentioned above, taxodiaceae (taxodium type, principally) are supposed to disappear at the ppb (lona et al., 1969), but this section lacks a precise chronostratigraphic reference. taxodiaceae are absent along the whole colle curti and cesi record (i.e. from about the upper part of c1r.2r subchron on). in the south, the dominant taxodiaceae at vrica is sequoia type, and its occurrence is testified until about 1.3 ma; at monte san giorgio they are sporadic between 1.23 and 1.095 ma. at santarcangelo, taxodiaceae are sparsely present only in the basal part of the succession. they are absent in the younger sites of isernia, vallo di diano (here sparse grains of taxodiaceae were interpreted as probably reworked elements), and acerno. the analysis of the vegetation assemblages and of their spatial distribution, together with the geological and sedimentological features of the deposits, evidenced a predominant climatic control on the taxodiaceae disappearance. edaphic and depositional factors played a subordinate role, which explains their survival as relicts (or in previous times phases of particular wide spread) in swamp environments, predominantly with taxodium type (e.g. in the tiberino or upper valdarno basins), or close to slopes (e.g. at crotone, close to the sila), mostly with sequoia type. the taxodiaceae stratigraphical range shows that their disappearance cannot be considered as an isochronous and sudden event matching exactly the ppb. it is therefore impossible to use such event (i.e. the tiberian boundary) to cross-correlate italian successions. using the tiberian boundary to establish widescale correlations resulted incorrect (lona, 1971) [see, for instance, the correlation of the tiberian boundary with the reuverian/pretigl ian transit ion of the netherlands (zagwijng, 1975). the latter in fact is correlatable with the piacenzian/gelasian boundary (at ca 2.6 ma) and not with the ppb (at ca 1.8 ma), on the basis of chronostratigraphical considerations]. 6.2. the disappearance of subtropical to warm temperate/temperate taxa during the neogene and the pleistocene, the progressive decrease of temperature in italy, as well as the change in amount and distribution of precipitations, caused not only the already mentioned gradual disappearance of taxodiaceae, but also that of many other taxa with present day tropical to subtropical, or even extraeuropean warm-temperate/temperate range. some of them, such as cathaya, tsuga, cedrus, carya, pterocarya, liquidambar, survive for a while as relicts under microclimatic and/or edaphic conditions, before becoming thoroughly extinct. ccaatthhaayyaa is a pinaceae which now lives at various altitudes, from less than 300 m to over 1800 m a.s.l. (liu et al., 1997), only in a restricted area of northern china (wang, 1961; liu et al., 1997). the climatic requirements of cathaya identified by faquette et al. (1998a, b) are shown in table i, although this taxon probably has a wider potentiality of occurrence. cathaya shows repeated phases of expansion during the middle (e.g. at stirone; bertini, 2001) and late (e.g. at vrica; combourieu-nebout & vergnaudgrazzini, 1991) pliocene, when it became one of most important components of the mesophilous forests, remplacing taxodiaceae which characterized the zanclean thermophilous forests. cathaya progressively declined during the early pleistocene (along with pinus haploxylon type), while at the same time tsuga shows successive peaks in abundance. nowadays ttuussggaa occurs with 14 species in temperate zones of the northern hemisphere (north america, china, japan and himalaya), where it grows both alone and in association with deciduous elements. it is more tolerant than any other pinaceae to the shade, but it is also the less resistant to drought; in fact, it requires at least 1000 mm of annual precipitation. the aridity was an important limiting factor also in the past distribution and expansion of tsuga; in fact, as already discussed in paragraph 5, it has never been a major component of the vegetation in southern sites. in northern and central italy, tsuga expanded repeatedly since the early pleistocene, especially close to the jaramillo interval; the ranica, upper valdarno, cesi and colle curti samples clearly attest this. in the cesi and colle curti successions, the disappearance of tsuga, during the lower part of the brunhes chron, followed repeated phases of peak abundance between the jaramillo and the overlain c1r.1r subchron. bertini (2000) related this to the shift in global aridity. in the netherlands and at tenaghi phil ippon iii (macedonia, greece), tsuga shows a similar trend during the same time-interval (zagwijn, 1963; zagwijn & de jong, 1984; van der wiel & wijmstra, 1987). these data confirm the global effects of the mid-pleistocene climate transition at ca 0.9 ma (ruddiman et al., 1989; raymo et al., 1997). in the pollen diagrams, tsuga is often associated to cceeddrruuss to form the so called “tsugacedrus complex “ (e.g. bertoldi, 1995). today cedrus has a discontinuous range restricted to the montane or high montane areas between latitudes 30-40° n in three main separated regions in northern africa and southern asia. according to combourieu-nebout et al. (2000) its climatic requirements are 4 to 10 °c of ta, and 500 to 2000 mm of pa whereas fauquette et al. (1998a) propose a larger range (tab. i). because of its greater tolerance, cedrus lasted longer than tsuga (tab. i), though at generally lower percentages in the late early pleistocene records (e.g. cesi, la pineta and vallo di diano). cedrus is absent only at pianico-sellere and acerno. together with the earlier coniferous forest taxa, many subtropical to warm temperate deciduous taxa, typical of the warm mixed forests, progressively disappear following climatic gradients; some of the disappeared taxa live today in the eastern mediterranean. among the juglandacee, engelhardia, carya and pterocarya progressively disappeared from the pleistocene records. among the numerous pliocene and early pleistocene 27early to middle pleistocene changes ... 28 a. bertini f ig .3 g en er al s ch em e of v eg et at io n an d cl im at e in it al y du rin g th e la te l at e p lio ce ne a nd th e m id dl e p le is to ce ne . t he m ai n flo ris tic e ve nt s de te ct ed in th e su cc es si on s ar e sh ow n on th e rig ht . genera of hamamelidaceae, embolathera, distylium, parrotiopsis, parrotia persica, and liquidambar disappeared one after another. the climatic requirements of some of these taxa are reported in table i. zelkova, a genus of ulmaceae, a family also including ulmus and celtis, represents a typical example of lazarus taxon. it was widespread during early and middle pleistocene, with variable abundances. it then survived in the eemian during forest phases and finally disappeared from central italy at about 31 ka (follieri et al., 1986; 1988). no other records testified its presence later than this time in italy until it was discovered in a relict station in sicily (di pasquale et al., 1992). 6.3. vegetation and climatic history during the early and middle pleistocene the early pleistocene pollen assemblages originated from a thorough restructuring of the neogene palaeonvironmental settings. the changes in temperature and precipitation following the maximum expansion of the arctic ice at 2.6 ma, as well as the new topography resulting from the rise of apennines caused the already mentioned progressive disappearance of tropical and subtropical forest taxa, a spread of both altitudinal arboreal taxa and herbs, and the creation of new competition patterns (fig. 3). the effects of the climatic modifications at the transition to the middle pleistocene gave rise to new major changes in the floristic and vegetal assemblages, which progressively attained a modern aspect. the eeaarrllyy pplleeiissttoocceennee is a time when open vegetation (arid and cool to cold climate conditions) and forest (humid and warm-temperate climate conditions) alternated, reflecting g/i fluctuations. the open vegetation assemblages include a large amount of steppe taxa, among which artemisia and ephedra, and sometimes also thermophilous taxa, such as cistus and phlomis fruticosa. the warm temperate forest assemblages include deciduous taxa, such as quercus, carya, carpinus, pterocarya, ulmus and zelkova. in northern italy, g/i cycles are marked by alternations of coniferous forests (especially formed by picea, with minor abundance of cedrus and tsuga) and deciduous forests (especially formed by carya, quercus, carpinus, pterocarya,) which translate relatively humid and cool to cold /humid warm temperate fluctuations. during the mmiiddddllee pplleeiissttoocceennee, the climate keeps alternating, and vegetation accordingly. the southern italian sites show alternations of artemisia (plus ephedra) steppes and temperate to warm-temperate deciduous forests. nonetheless, a generalized drop in temperature in both steppe and forest phases is indicated by changes in the floristic assemblages. for example, hippophaë rhamnoides expanded during the steppe phases, whereas thermophilous taxa, such as cistus and phlomis fruticosa, disappeared. the most thermophilous arboreal taxa progressively declined during the forested phases in accordance with climatic gradients (e.g. parrotia persica, carya, pterocarya and liquidambar). this is in agreement with the marine oxygen isotopic records, and the so called mid-pleistocene climate transition. 6.4. the palynological record from other italian sites palynological studies were carried out in many other sites, which were not included here because of their controversial stratigraphic position. the palynological content of three cores (ve-i, ve-i bis, ve-ii), collected from the holocene upper pliocene succession (cnr 1971; favero et al., 1973) of the venise area, at the northern end of the adriatic sea, in a foreland wedged between the eastern southern alps and the apennine chain, has been analysed by mullenders et al. (1996), who proposed to place the plio-pleistocene boundary at about 900 m and the tiberian boundary at about 820 m giving rise to an evident conflict. more recently kent et al. (2002) made an integrated magneto-bio-cyclostratigraphical study ena29early to middle pleistocene changes ... tab. i climatic indications yielded by selected taxa, and their present geographic distribution (from fauquette et al. 1998 a, b). pa: total annual precipitation; ta: mean annual temperature, tc: mean temperature of the coldest month, tw: mean temperature of the warmest month. the reader should refer to thompson et al. (1999) for additional information on climatic parameters. in this paper one can find alternative observations to fauquette et al..’s (1998 a, b) data, especially about sequoia sempervirens. ttaaxxaa ppaa ((mmmm ttaa ((°°cc)) ttcc ((°°cc)) ttww ((°°cc)) mmooddeerrnn ddiissttrriibbuuttiioonn engelhardia 800-2000 15-25 10-20 25-35 mexico, se asia, india, south china, taiwan, malaysia dystilium 800-2000 15-25 10-20 25-35 se asia, china, indonesy parrotia persica 300-1500 14-20 4-8 24-35 iran parrotiopsis 300-1000 7-13 -7-3 17-24 afghanistan, pakistan, india metasequoia 800-1600 10-20 0-10 20-30 china sciadopitys 1000-2500 5-15 -5-5 15-25 japan sequoia sempervirens 1200-2500 15-18 5-15 10-25 california sequoiadendron giganteum 900-1500 8-15 0,5-11 9-26 california taxodium distichium 1100-2400 16-25 5-20 25-30 se usa cathaya 1000-1600 10-20 5-10 15-30 north china liquidambar 1000-1600 10-23 0-18 20-30 north america, mexico, east asia and turkey, japon tsuga 1000-2000 0-12 -10-6 5-15 north america; japon, china, himalaya phlomis fruticosa 400-800 15-20 5-15 20-30 east mediterranean, sicily, middle east cedrus 500-1500 7-18 -1-11 18-28 northern africa and southern asia cedrus 750-1250 8-13 1-5 17-23 bling the reconstruction of the pleistocene history of sea-level changes in the venice region, in a 950 meterdeep drill core, named vveenniiccee--11 which corresponds to the composite section of the two cores ve-i and ve-i bis. kent et al.’s (2002) study permits the detection of the brunhes and upper matuyama chrons (not older than 1.7 ma) from the top of the core to 727.8 m, and from 727.8 m at least to the unconformity at 813 m, respectively. the interpretation of the succession from the break to the base of the measured section is debated. according to kent et al. (2002) the lower matuyama might extend from 813 to 887.2 m, with a hiatus cutting out at least the whole olduvai subchron (including the ppb). in this case, the matuayama/gauss boundary (at 2.58 ma) would occur at 887.2 m. alternatively, the normal polarity interval extending from 887.2 m downwards could correspond to an extremely long reunion subchron (2.14-2.15 ma) section. in spite of its above mentioned hiatus from the upper pliocene to the lower calabrian, venice-i, appears to be a significant succession to document the major lower and middle pleistocene floristic and vegetational changes in a prevalently marine environment of northern italy. the accurate revision of the palyological record (e.g. not all the recognized taxa are shown in the palynological diagrams, sporae are included in the pollen sum) made by mullenders et al. (1996) needs to be included in an adequate stratigraphical framework. such an integration has been tempted (luca capraro, 2003: pers. com.; massari et al., submitted). on the basis of kent et al.’s (2002) stratigraphical evidence, i supposed that mullenders et al.’s (1996) location of the ppb and of the tiberian boundary must be rejected. in fact, the tiberian boundary would fall below the unconformity at 813 m, i.e. in the matuyama reverse polarity interval, at least at 1.95 ma. the taxodium acme event (value up to 20%) used by mullenders et al. (1996) to define the tiberian boundary could correspond to one of the repeated climatic fluctuations which occur between 2.6 and 1.95 ma. in the succession from 950 to 820 m, the sparse occurrence of taxodium (2.2%, 14% and 0.8%), as well as the absence of repeated changes in the palynological assemblages (mullenders et al., 1996) which match the g/i cycles possibly suggest a younger age as well as a shorter overall extent of this portion (i.e. it would be the only occurrence of the reunion) than in the case of an occurrence of the gauss/matuyama boundary. the absence of significant changes near the top of the supposed gauss/matuyama boundary, where the first glacial phases start, at 2.6 ma, apparently supports this hypothesis. taxodium is almost completely absent from the pleistocene section of the sequence, with only a virtually occurrence of 0.2% and 0.6% at 561 m and 453.65 m, respectively. cathaya is not included in the floristic taxa, but it might not have been distinguished, at least in the pliocene interval, from the pinus haploxylon type, which is present up to 518 m. tsuga shows important acme phases throughout the upper matuayama. just above the highest occurrence of the large gephyrocapsa (kent et al., 2002) tsuga strongly decreases to show an isolate peak in the lower part of the brunhes (close to mis 18; kent et al., 2002). mullenders et al. (1996) recognized the first cold phase (“cryomère”) in the section from the so-called veneziano” boundary, just under the base of the brunhes, up to 576 m. the absence of evidence of previous cold phases (e.g. those corresponding to mis 22) in the palynological record is perplexing. furthermore, drops in the abundances of many taxa, such as cedrus, carya, zelkova, pterocarya, also occur before this boundary. later on, occurrences generally maintain very low (only pterocarya and zelkova show significant expansions). the ccoommppiiaannoo continental basin is located in northern italy (val di taro). pollen analyses were carried out in 6 main short sections by bertoldi (1995). in the lower portion of the outcrops sciadopitys reaches 19.4 %, followed by taxodium type (at 7.4%). moving upwards in the sequence, tsuga, cedrus, pinus haploxylon s.s. dominate the assemblages, whereas carya and pterocarya are scanty and sporadic. in the upper beds, all these taxa are missing. on the basis of this paleobotanical evidence, and in particular of the occurrence and disappearance of taxodium type, bertoldi (1995) referred the lower part of the compiano succession to the plio-pleistocene transition, and dated the overlying part of the sequence to the early and middle pleistocene. tsuga, pinus haploxylon type, cedrus, carya, pterocarya and zelkova also occur in the continental sediments of the gguubbbbiioo (perugia) and lleeoonneessssaa (rieti) basins (central italy), at 425 m and 900 m above sea level, respectively (lona & ricciardi, 1961a; ricciardi, 1965). zelkova is also reported in the mmeerrccuurree basin (southern italy), at 500 m above sea level, while tsuga, pinus haploxylon type and cedrus are missing (lona & ricciardi, 1961b); here, rare pollen grains of carya and pterocarya are regarded as reworked elements. in the light of this palynological evidence, the gubbio and leonessa deposits seem older than the mercure succession, which in turn seems to correlate with the previously described cesi sequence (bertini, 2000). unfortunately, the different latitude and altitude of the latter four continental sites, added to the already mentioned absence of an ascertained time reference, make any interpretation and attempted correlation very doubtful. lacking a well-defined palynostratigraphical framework for the early and middle pleistocene, integrated by time-diagnostic elements, correlations based solely on ecobiostratigraphical events, including last occurrences of specific key taxa, are hazardous. nevertheless, this summary singled out several key-sections in northern, central and southern italy with well calibrated major floristic and vegetational events. these can represent significant reference sections provided that geographical and edaphic factors are duly inspected. 77.. ccoonncclluussiioonn this paper aimed at showing the power of the pollen record in paleoenvironmental reconstructions and stratigraphical research, especially associated to mighty time-diagnostic implements such as tephras, magnetoand/or bio-magnetostratigraphy. this is the basis for high resolution studies and reliable correlations. the sites selected here delineate the following 30 a. bertini history of the italian early to middle pleistocene flora and climate: the unsuitable climatic conditions of this time progressively depleted the flora. in the early pleistocene, the g/i cycles caused the disappearance of extreme thermophilous taxa which are prevalently distributed in subtropical to warm temperate habitats today. the transition to the middle pleistocene was marked by a drop in the temperature and by a change in the dominant ciclicity; the effects on the flora were thus amplified. taxodiaceae, cathaya (plus pinus haploxylon type), tsuga, cedrus, carya, pterocarya, along with other taxa, progressively disappeared throughout the pleistocene. climatic gradients linked to the latitude, altitude, physiography of the sites justify their different calendar of extinction: a precise chronological reference for all these events thus is mandatory to establish reliable correlations with other such records in northern europe as well as in other mediterranean areas. changes in vegetation, also linked to g/i cycles, have been detected in both the early and middle pleistocene. glacials are generally marked by a dominance of herbaceous taxa indicative of steppe-like conditions. nevertheless, herbs never became important components of the landscape in the northern sites; on the contrary, coniferous forests dominated. interglacials are indicated by the expansion of mesophilous deciduous trees. middle pleistocene g/i cycles were characterized by lower temperatures, which caused the disappearance of extreme thermophilous taxa. on this basis we can distinguish between early pleistocene “warm’ steppes and middle pleistocene “cold’ steppes. the early pleistocene is characterized by short alternations of xeric-cool-temperate phases (or only cooltemperate phases with irrelevant decreases in humidity, in the north) (glacials) and warm moist phases (interglacials) with a predominance of 41 ka cycles. long alternations of xeric cool to cold phases (glacials) and humid warm temperate phases (interglacials) with a predominance of 100 ka cycles characterized the middle pleistocene. the selection of reference sections is indispensable to correlate sites with a controversial stratigraphical position. the information provided by the selected sections form an indispensable reference for most reliable climate quantifications and mappings of the vegetation for the early to middle pleistocene interval. the combination of these two approaches has secured striking results in studies of neogene sites (e.g. suc et al., 1999; fauquette et al., 1998a, b; fauquette & bertini, in press; fauquette et al., submitted). aacckknnoowwlleeddggmmeennttss the works of adele bertini were financially supported by m.i.u.r. funds. this work also contributed to the projects: " la biodiversité végétale méditerranéenne depuis 6 ma environnements, vie et sociétés: institut français de la biodiversité" and galileo 2003 (c.r.u.i.). special thanks to paul mazza for improving the english of the manuscript. rreeffeerreenncceess abbate e., 1983 schema stratigrafico della successione neoautoctona del valdarno superiore e del bacino di arezzo. in: abbate e. & sagri m. (eds.), “i depositi fluvio-lacustri del valdarno superiore”. ist. geol. paleont. univ. firenze, 1-6. aguirre e. & pasini g., 1985 the pliocene pleistocene boundary. episodes, 88//22, 116 120. albianelli a., bertini a., magi m., napoleone g. & sagri m., 1995 il bacino plio-pleistocenico del valdarno superiore: eventi deposizionali, paleomagnetici e paleoclimatici. il quaternario, 88 (1), 11-18. albianelli a., azzaroli a., bertini a., ficcarelli g., napoleone g. & torre d., 1997 paleomagnetic and palynologic investigations in the upper valdarno basin (central italy): calibration of an early villafranchian fauna. riv. it. paleont. strat., 110033,, 111-118. albianelli a., magi m., mazzini m. & napoleone g., 2002 the plio-pleistocene boundary in the northern apennine continental deposits as defined by the faella magnetostratigraphic section in the upper valdarno. bol. soc. geol. it., volume speciale, 11, 473-479. azzaroli a., 1983 quaternary mammals and the endvillafranchian dispersal event a turning point in the history of eurasia. palaeogeogr., palaeoclimatol., palaeoecol., 4444, 117-149. azzaroli a., 1995 the “elephant-equus” and the “endvillafranchian” dispersal events in eurasia. in: vrba e.s., denton g.h., partridge t.c. and burckle l.s., (eds.): palaeoclimate and evolution, with emphasis on human origins. yale university press, 311-318. azzaroli a. & lazzeri l., 1977 i laghi del valdarno superiore. centro studi geol. appennino, cnr, univ. di firenze, publ. 2266, 4 pp., geological map. azzaroli a., de giuli c., ficcarelli g. & torre d., 1988 late pliocene to early mid-pleistocene mammals in eurasia: faunal succession and dispersal events. palaeogeogr., palaeoclimatol., palaeoecol., 6666, 77-100. baggioni m., suc j.-s. & vernet j.l.,1981 le pliopléistocène de camerota (italie méridionale): géomorphologie et paléoflores. géobios 1144, 229-237 bassett, m. g., 1985 towards a "common language" in stratigraphy. episodes, 88 (2), 87-92. becker-platen j.d., benda l., cepek p., daniels c.h., mengeling h., meyer k.j., steffens p., streif h. & vinken r., 1977 beitrage zur plio-pleistozängrenzziehung in mittelitanien. giorn. geol., 22 xli (i-ii), 107-114. belluomini g., manfra l. & palombo m.r., 1997 a recent aminochronology of pleistocene mammals from rome area and isernia-la pineta deposits (italy). geol. romana, 3333, 73–79. bertini a., 1992 palinologia ed aspetti ambentali del versante adriatico dell’appennino centro-settentrionale durante il messiniano e lo zancleano. unpublished phd, university of modena (italy), 88 pp. bertini a., 1994 a messinian-zanclean vegetation and climate in north-central italy. hist. biol., 99, 3-10. bertini a., 1994 b palynological investigations on upper neogene and lower pleistocene sections in central and northern italy. mem. soc. geol. it., 31early to middle pleistocene changes ... 4488, 431-443. bertini a., 2000 pollen record from colle curti and cesi: early and middle pleistocene mammal sites in the umbro-marchean apennine mountains (central italy). j. quat. sci., 1155 (8), 825-840. bertini a., 2001 pliocene climatic cycles and altitudinal forest development from 2.7 ma in the northern apennines (italy): evidence from the pollen record of the stirone section (~5.1 to ~2.2 ma). géobios, 3344 (3), 253-265. bertini a., in press palynological evidence of upper neogene environments in italy. acta universitatis carolinae-geologica. bertini a. & roiron p., 1997 evolution de la végétation et du climat pendant le pliocène moyen, en italie centrale: apport de la palynologie et de la macroflore à l’étude du bassin du valdarno supérieur (coupe de santa barbara). c. r. acad. sci. paris, 332244, série iia, 763-771. bertini a. & vannucchi d., 1993 etude palynologique du pliocène de l’italie septentrionale: la section de stirone. xiii aplf symposium, abstracts, 33. bertini a., londeix l., maniscalco r., di stefano a., suc j.-p., clauzon g., gautier f. & grasso m., 1998 paleobiological evidence of depositional conditions in the salt member, gessoso-solfifera formation (messinian, upper miocene) of sicily. micropaleontology, 4444 (4), 413-433. bertolani-marchetti, d., 1978 possibile significato paleogeografico e paleoecologico delle taxodiaceae nei diagrammi pollinici del pliocene terminale e dell’eopleistocene. giorn. bot. it., 111122: 296-297. bertolani-marchetti, d., accorsi c.a., pelosio g. & raffi, s., 1979 palynology and stratigraphy of the pliopleistocene sequence of the stirone river (northern italy). pollen et spores, 2211 (1-2), 149-167. bertoldi r., 1977 studio palinologico della serie di le castella. acc. naz. lincei, rend. cl. sc. ff. mm.nn., sviii, 6622, 547-555. bertoldi r., 1995 palinostratigrafia dei bacini intermontani dell’appennino nord-occidentale. il quaternario, 88 (1), 61-70. bertoldi r., rio d. & thunell r., 1989 pliocene/ pleistocene vegetational and climatic evolution of the south-central mediterranean. palaeogeogr., palaeoclimatol., palaeoecol., 7722, 263-275. bini a., cita m.b. & gaetani m., 1978 southern alpine lakes – hypothesis and an erosional origin related to the messinian entrenchment. marine geology, 2277, 271-288. borrelli a., ciampo g., de falco m., guida d. & guida m., 1988 la morfogenesi di m.te bulgheria (campania) durante il pleistocene inferiore e medio. mem. soc. geol. it., 4411, 667-672. bossio a., costantini a., foresi l.m., lazzarotto a., mazzanti r., mazzei r., pascucci v., salvatorini g., sandrelli f. & terzuoli a., 1998 neogenequaternary sedimentary evolution in the western side of the northern apennines (italy). mem. soc. geol. it., 5522, 513-525. brambilla g. & lualdi a., 1987 il pliocene della provincia di bergamo (italia settentrionale): analisi faunistica ed inquadramento cronologico e paleoambientale. bol. soc. paleont. it., 2255 (3), 237-266. brambil la g., cantalupi g. & lualdi a., 1983 panorama generale del pliocene nel bergamasco. riv. mus. civ. sci. nat. bergamo, 66, 3-25. brenac p., 1984 végétation et climat de la campanie du sud (italie) au pliocène final d’après l’analyse pollinique des dépôts de camerota. ecologia mediterranea, 1100, 207-216. bucha v., horacek j., koci a., sibrava v. & lozek v., 1975 paleomagnetic correlations of pleistocene sediments of central europe. i.g.c.p., quaternary glaciations in the northern hemisphere, report 2, salzburg, september, 1100--1144, 1974, 59-72. capotondi l., 1992 eventi faunistici ed isotopici del tardo neogene registrati nel mediterraneo. implicazioni stratigrafiche e paleoceanografiche. unpublished phd thesis university of parma (italy), 134 pp. cinque a., patacca e., scandone p. & tozzi m., 1994 quaternary kinematic evolution of the southern apennines. relationships between surface geological features and deep lithospheric structures. ann.geofisica, 3366,, 249-260. channel j.e.t., poli m. s., rio d., sprovieri r. & villa g., 1994 magnetic stratigraphy and biostratigraphy of pliocene “argille azzurre” (northern apennines, italy). palaeogeogr., palaeoclimatol., palaeoecol., 111100, 83-102. ciaranfi n., marino m., sabato l., d’alessandro a., & de rosa r., 1996 studio geologico-stratigrafico di una successione infra e mesopleistocenica nella parte sudoccidentale della fossa bradanica (montalbano jonico, basilicata). bol. soc. geol. it., 111155, 379-391. ciaranfi n., d’alessandro a., girone a., maiorano p., marino m., soldani d. & stefanelli s., 2001 pleistocene sections in the montalbano jonico area and the potential gssp for early-middle pleistocene in the lucania basin (southern italy). mem. sc. geol., 5533, 67-83. cnr, 1971 relazione sul pozzo venezia 1-cnr. 1° fase: operazioni di cantiere e analisi delle carote. laboratorio dinamica grandi masse, consiglio nazionale delle ricerche, venice. coltorti m., albianelli a., bertini a., ficcarelli g., laurenzi m.a., napoleone g. & torre d., 1998 the colle curti mammal site in the colfiorito area (umbria-marchean apennine, italy): geomorphology, stratigraphy, paleomagnetism and palynology. quat. int., 4477//4488,107-116. combourieu-nebout n., 1987 les premiers cycles glaciaire-interglaciaire en région méditerranéenne d'après l'analyse palynologique de la série pliopléistocène de crotone (italie méridionale). thèse, univ. montpellier, 161 pp. combourieu-nebout n., 1993 vegetation response to upper pliocene glacial/interglacial cyclicity in the central mediterranean. quat. res., 4400, 228-236. combourieu-nebout n., 1995 réponse de la végétation de l’italie méridionale au seuil climatique de la fin du pliocène d’après l’analyse pollinique à haute résolution de la section de semaforo (2.46 à 2.1 ma). c. r. acad. sci. paris, t. 332211, série iia, 659-665. combourieu-nebout n. & vergnaud-grazzini c., 1991 late pliocene northern hemisphere glaciations: the continental and marine responses in the central mediterranean. quat. sci. rev., 1100, 319-334. combourieu-nebout n, semah f. & djubiantono t., 32 a. bertini 1990 la limite pliocène-pléistocène: précision magnétostratigraphiques et climatiques par l’étude sériée de la coupe-type de vrica (crotone, italie). c. r. acad. sci. paris, t. 311, série iia, 851-857. combourieu-nebout, n., fauquette s. & quézel p., 2000 what was the late pliocene mediterranean climate like: a preliminary quantification from vegetation. bul. soc. géol. france, 117711 (2), 271-277. cremaschi m., 1983 la serie pleistocenica di isernia la pineta (molise) e la posizione stratigrafica dei suoli d’abitato paleolitici in essa inclusi. in: c. peretto, c. terzani, m. cremaschi (eds.), isernia la pineta, un accapamento più antico di 700 000 anni, calderini, bologna, 49–62. cremaschi m. & peretto c., 1988 les sols d’habitat du site paléo-lithique d’isernia la pineta (molise, italie centrale). l’anthropologie, 9922 (4), 1017–1040. cremaschi m. & ravazzi c., 1995 nuovi dati stratigrafici e geocronologici sul bacino di leffe (prealpi lombarde bergamo). il quaternario, 88 (1), 167-182. delitala m.c., fornaseri m. & nicoletti m., 1983 datazioni argon– potassio sulla serie pleistocenica di isernia la pineta. in: c. peretto, c. terzani, m. cremaschi (eds.), isernia la pineta, un accapamento più antico di 700 000 anni, calderini, bologna, 65–66. di pasquale g., garfi g. & quézel p., 1992 sur la présence d’un zelkova nouveau en sicile sud-orientale (ulmaceae). biocosme mésogéen, 88, (4,9,1), 401-409. dubois j.m., 2001 cycles climatiques et paramètres orbitaux vers 1 ma. etude de la coupe de monte san giorgio (caltagirone, sicile): palynologie, isotope stables, calcimétrie. mémoire du dea-lyon (france), 52 pp. emiliani c., mayeda t. & selli r., 1961 paleotemperature analysis of the plio-pleistocene section at le castella, calabria, southern italy. geol. soc. am. bull., 7722, 679-688. fauquette s. & bertini a., in press quantification of the northern italy pliocene climate from pollen data: a very peculiar region. boreas fauquette s., guiot j. & suc j.-p., 1998 a a method for climatic reconstruction of the mediterranean pliocene using pollen data. palaeogeogr., palaeoclimatol., palaeoecol., 114444, 183-201. fauquette s., quézel p., guiot j. & suc j.-p., 1998 b signification bioclimatique de taxons-guides du pliocène méditerranéen. géobios 3311, 151-169. fauquette s., suc j.-p., bertini a., popescu s.-m., warny s., bachiri taoufiq n., perez villa m.-j., ferrier j., chikhi h., subally d., feddu n. & clauzon g., submitted. how much did climate force the messinian salinity crisis? quantified climatic conditions from pollen records in the mediterranean region. palaeogeogr., palaeoclimatol., palaeoecol. faverov., alberotanza l. & barbero s .r., 1973 aspetti paleoecologici, sedimentologici e geochimici dei sedimenti attraversati dal pozzo ve 1 bis. c.n.r.,consiglio nazionale delle richerche, venezia., 51pp. ficcarelli g., abbazzi l., albianelli a., bertini a., coltorti m., magnatti m., masini f., mazza p., mezzabotta c., napoleone g., rook l., rustioni m. & torre d., 1997 cesi an early middle pleistocene site in the colfiorito basin (umbro-marchean apennine), central italy. j. quat. sci., 1122 (6), 507-518. follieri m., magri d. & sadori l., 1986 late pleistocene zelkova extinction in central italy. new. phytol., 103, 269-273. follieri m., magri d. & sadori l., 1988 250,000-year pollen record from valle di castiglione (roma). pollen et spores, 3300 (3-4), 329-356. fusco f., 1996 analisi polliniche nelle successioni pleistoceniche inferiori della valle del lamone (appennino nord-orientale). evoluzione paleovegetazionale e paleoclimatica. unpublished phd thesis, university of bologna (italy), 96 pp. ghisetti f. & vezzani l., 1999 depth and modes pliocene-pleistocene crustal extension of the apennines (italy). terra nova, 1111 (2-3), 67-72. gliozzi e., abbazzi l., argenti p., azzaroli a., caloi l., capasso barbato l., di stefano g., esu d., ficcarelli g., girotti o., kotsakis t., masini f., mazza p., mezzabotta c., palombo m.r., petronio c., rook l., sala b., sardella r., zanalda e. & torre d., 1997 biochronology of selected mammals, molluscs and ostracods from the middle pliocene to the late pleistocene in italy. the state of the art. riv. it. paleont. strat., 110033 (3), 369-388. hilgen f.j., 1991 astronomical calibration of gauss to matuyama sapropels in the mediterranean and implication for the geomagnetic polarity time scale. earth planet. sci. lett., 110044, 226-244. iaccarino s., 1996 il plio-pleistocene del torrente stirone: evoluzione delle conoscenze. in guida alle escursioni del xiii convegno della società paleontologica italiana, 19-26. iaccarino s. & pugliese n., 1988 prime considerazioni sul passaggio zancleano-piacenziano nella serie del torrente stirone (emilia-romagna). atti iv simposio ecologia e paleoecologia delle comunità bentoniche, sorrento, 805-814. kent d. v., rio d., massari f., kukla g. & lanci l., 2002 emergence of venice during the pleistocene. quat. sci.rev., 2211, 1719 1727. kumai h., 1996 overview of chiba research area and section proposal for a stratotype for the lowermiddle pleistocene boundary. proceedings on the research of stratotype for the lower-middle pleistocene boundary, international tesearch group for the lower-middle, middle-upper pleistocene boundary, japan association for quat. res., 3-12. lebreton v., 2001 paysages et climats contemporains des premiers hominidés en italie. analyse pollinique des sites du pléistocène inférieur et moyen de ca’ belvedere di monte poggiolo (forlì, emilieromagne) et de la pineta (isernia, molise). thèse, muséum national d’histoire naturelle de paris, france, 261 pp. lebreton v., 2002 végétation et climat au pléistocène inférieur et moyen à la pineta (isernia, italie). c. r. palevol., 00, 1–7. liu y.s., setter r. & fergusson d.k., 1997 fossil pollen grains of cathaya (pinaceae) in the miocene of estern china. in: proceeding of the 4th european paleobotanical and palynological conference. mededelingen nederlands instituut voor toegepaste geowetenshappen, 5588, 227-235. 33early to middle pleistocene changes ... lona f., 1950 contributi alla storia vegetazione e del clima nella val padana. analisi pollinica del giacimento villafranchiano di leffe (bergamo). atti soc. ital. sc. nat., 8899, 120-178. lona f., 1962 prime analisi pollinologiche sui depositi terziari-quaternari di castell’arquato: reperti di vegetazione da clima freddo sotto le formazioni calcaree a amphistegina. bol. soc. geol. it., 8811, 1-5. lona f., 1963 boschi di cedrus a sciadopitys in emilia durante il pliocene. giorn. bot. it., 8811, 1-5. lona f., 1971 correlazioni tra alcune sequenze micropaleobotaniche plio-pleistoceniche continentali e marine dell’italia centro-settentrionale ed europa centro-occidentale con riferimento al limite tiberiano. l’ateneo parmense – acta naturalia, 66, 145-157. lona f. & bertoldi r., 1972 la storia del pliopleistocene italiano in alcune sequenze lacustri e marine. mem. ac. naz. lincei, 88, 1-47. lona f. & follieri m., 1957 successione pollinica della serie superiore (günz-mindel) di leffe (bergamo). verhandlungen der vierten internaz. tagung der quartärbotaniker. veröff. geobot. inst. rübel in zürich, 3344, 86-98. lona f. & ricciardi e., 1961 a studio pollinologico stratigrafico su una serie pleistocenica dell’italia centrale (bacino di gubbio, perugia). pollen et spores, 33 (1), 93-100. lona f. & ricciardi, e., 1961 b reperti pollinologici nei depositi pleistocenici del bacino lacustre del mercure (italia meridionale, regione lucanocalabra). pollen et spores, 33 (1), 85-92. lona f., bertoldi r. & ricciardi e., 1969 pliopleistocene boundary in italy based on the leffian and tiberina vegetational and climatological sequences. coll. viii inqua congress, sect. stratigraphy, paris, 573-574. lona f., bertoldi r. & ricciardi e., 1971 synchronization of outstanding stages of some italian upper pliocene and lower pleistocene sequences, especially by means of palynological researches. comm. v congr. du neogene medit., sect. paleobot., lyon. lourens l.j., hilgen f.j. & raffi i., 1998 base of large gephyrocapsa and astronomical calibration of early pleistocene sapropels in site 967 and hole 969d: solving the chronology of the vrica section (calabria, italy). in: robertson a.h.f., emeis k.c., richter c., camerlenghi a. (eds.), proc.odp sci. results 116600, 191-197. lourens l.j., hilgen f.j., raffi i. & vergnaud-grazzini, c., 1996a early pleistocene chronology of the vrica section (calabria, italy). paleoceanography, 1111, 797-812. lourens l.j., hilgen f.j., zachariasse w.j., van hoof a.a.m., antonarakou a. & vergnaud-grazzini c., 1996b evaluation of the plio-pleistocene astronomical time scale. paleoceanography, 1111, 391-413. magi m. & sagri m., 1994 the valdarno basin. 15th ias regional meeting. ischia (italy), excursion b4 guidebook, 54-61. martini i.p. & sagri m., 1993 tectono sedimentary characteristics of late miocene-quaternary extensional basins of northern apennines, italy. earth sci. rev., 3344, 197-233. mary c., iaccarino s., courtillot v., besse j. & aissaoui d.m., 1993 magnetostratigraphy of pliocene sediments from the stirone river (po valley). geophys. j. int., 111122, 359-380. masini f., giannini t., abbazzi l., fanfani f., delfino m., maul l.c. & torre d., in press a small vertebrate fauna from the lacustrine succession of san lorenzo (santarcangelo basin, basilicata) and remarks on pleistocene rodent chronology. quat. int. massari f., rio d., sgavetti m., asioli a., backman j., capraro l., d’alessandro a., fornaciari e. & prosser g., 2001 the middle pleistocene of the crotone basin. mem. sc. geol., 5533, 85-123. mazza p., bertini a. & magi m., submitted the late pliocene site of poggio rosso (central italy): taphonomy and paleoenvironment. palaios merla g. & abbate e., 1967 note illustrative della carta geologica d’italia, f. 114 (arezzo). servizio geologico d’italia, 52 pp. michaux j., suc j.p. & vernet j.l., 1979 climatic inference from the history of the taxodiaceae during the pliocene and the early pleistocene in western europe. rev. palaeobot. palynol., 2277, 185-191. monegatti p. & pelosio g., 1994 paleoenvironmental evolution of a pleistocene lagoon (stirone river, emilia, north italy). bol. soc. paleont. it., spec.vol., 22, 197-202. moscariello a., ravazzi c., brauer a., mangili c., chiesa s., rossi s., beaulieu j.l. de, & reille m., 2000 a long lacustrine record from the pianicosellere basin (middle-late pleistocene, northern italy). quat. int., 7733//7744, 47-68. mullenders w., favero v., coremans m. & dirickx m., 1996 analyses polliniques de sondages a venise (ve-i,ve-i bis,ve-ii). aardkundige mededelingen 77, 87 -117. munno r., petrosino p., romano p., russo ermolli e. & juvigné e., 2001 a late middle pleistocene climatic cycle in southern italy inferred from pollen analysis and tephrostratigraphy of the acerno lacustrine succession. géographie physique et quaternaire, 5555,, 87-99. nakagawa h., niitsuma n., takayama t., tokunaga s., kitazato h. & koizumi i. 1980 preliminary results of magnetoand biostratigraphy of the vrica section (calabria, southern italy) in: nikiforova k.v. & dodonov a.y. (eds.), proceedings of the second symposium on the neogene/quaternary boundary, ussr, 115566. moscow, akademia nauk. nakagawa h., niitsuma n., takayama t., matoba y., oda m., tokunaga s., kitazato h., sakai t. & koizumi i. 1997 the magnetostratigraphy of the vrica section, italy and its correlation with the pliopleistocene of the boso peninsula, japan. in: van couvering (ed.), the pleistocene boundary and the beginning of the quaternary. world and regional geology, 99., 46-56. cambridge university press napoleone g., albianelli a., azzaroli a., bertini a., magi m., mazzini m., this volume calibration of the upper valdarno basin for correlating the apennine continental sequences. ori g.c. & friend p.f., 1984 sedimentary basins formed and carried piggy-back on active thrust sheets. geology, 1122, 475-478. papani g. & pelosio g., 1963 la serie plio-pleistocenica del t. stirone (parmense occidentale). bol. 34 a. bertini soc. geol. it., 8811(2), 293-335. pasini g. & colalongo m.l., 1994 proposal for the erection of the santernian/emilian boundary-stratotype (lower pleistocene) and new data on the pliocene-pleistocene boundary stratotype. bol. soc. paleont. it., 3333,101-120. pasini g., & colalongo m.l., 2001 the pliocenepleistocene boundary-stratotype and the proposed santernian/emilian boundary-stratotype (lower pleistocene) at the vrica section (calabria, southern italy). mem. sci. geol., 5533, 113-123. pelosio g. & raffi s., 1974 osservazioni su arctica islandica ed altri lamellibranchi dell’emilia occidentale. ateneo parmense-acta naturalia, 1100, 347367. pelosio g. & raffi s., 1977 preliminary remarks on mollusc assemblages of the stirone river pleistocene series (parma province, northern italy). x inqua congress, birmingham, 1-19. pini r. & ravazzi c., 2002 eleven vegetational and climatic cycles in the complete pollen diagram of leffe (late pliocene-early pleistocene, italian pre-alps, northern italy). 6th european paleobotany palynology conference. athens. abstract, 145-146. pinti d.l., quidelleur x., chiesa s., ravazzi c. & gillot p.y., 2001 k-ar dating of an early middle pleistocene distal tephra in the interglacial varved succession of piànico-sèllere (southern alps, italy). earth planet. sci. lett., 118888, 1-7. pontini m. r., 1997 analisi palinologica e interpretazione paleoclimatica dei depositi continentali del bacino tiberino (umbria, italia). umpublished ph.d thesis, university of perugia (italy), 134 pp. pontini m.r. & bertini a., 2000 late pliocene vegetation and climate in central italy: high resolution pollen analysis from the fosso bianco section (tiberino basin). géobios, 3333 (5), 519-526. pontini m.r., albianelli a., basilici g., bertini a. & napoleone g., 2002 pollen record and magnetostratigraphy of the middle-late pliocene lacustrine sequence in the tiberino basin, (central italy). bol. soc. geol. it., volume speciale, 11, 467-472. raffi s., 1982 stato delle conoscenze sulla sezione pleistocenica marina del torrente stirone (parma). in: cremonini, g. & ricci-lucchi f. (eds.), guida alla geologia del magine appenninico-padano,141-144. guida gelogica. regionale della s.g.i, bologna. raffi i., 2002 revision of the early-middle pleistocene calcareous nannofossil biochronology (1.75 -0.85 ma). marine micropaleontology, 4455, 25-55. raffi i. & rio d., 1980 calcareous nannofossil biostratigraphy of dsdp site 132 – leg 13 (tyrrhenian sea – western mediterranean). riv. it. paleont. strat., 8855, 127-172. raffi i., backman j., rio d. & shackleton n.j., 1993 plio-pleistocene nannofossi biostratigraphy and calibration to oxygen isotope stratigraphies from deep sea drilling project site 607 and ocean drilling program site 677. paleoceanography, 8, 387-408. ravazzi c., 1993 variazioni ambientali e climatiche al margine meridionale delle alpi nel pleistocene inferiore: stratigrafia e analisi pollinica della serie di leffe. unpublished phd thesis, university of milano (italy), 269 pp. ravazzi c. & moscariello a., 1998 sedimentation, paleoenvironmental evolution and time duration of earliest pleistocene climatic cycles in the 24-56 m fm core interval (leffe basin, northern italy). mededelingen nederlands inst. voor toegepaste geowetenschappen tno the dawn of the quaternary ed. by th. van kolfschoten and ph. gibbard 60, 467-489. ravazzi c. & rossignol-strick m., 1994 interglacialglacial cycles on the early pleistocene of the leffe basin (northern italy): preliminary report. hist.biol., 99, 11-15. ravazzi c. & rossignol-strick m., 1995 vegetation change in a climatic cycle of early pleistocene age in the leffe basin (northern italy). palaeogeogr., palaeoclimatol., palaeoecol., 111166, 105-122. ravazzi c., pini r., breda m., martinetto e., mattoni g., chiesa s., confortini f. & egli r., in press the lacustrine deposits of fornaci di ranica (late early pleistocene, italian pre-alps): stratigraphy, palaeoenvironment and geologic evolution. quat. int. raymo m.e., oppo d.w & curry w., 1997 the midpleistocene climate transition: a deep sea carbon isotopic perspective. paleoceanography 1122 (4), 546-559. ricci-lucchi f., 1986 the oligocene to recent foreland basins of the northern apennines. in p.a. allen and p. homewood (eds.), forelands basins. spec.publ. int. assoc. sedimentol., 88, 105-139. ricci-lucchi f., 1990 turbidites in foreland and onthrust basins of the northern apennines. palaeogeogr., palaeoclimatol., palaeoecol., 7777, 51-66. ricciardi e., 1961 analisi pollinologica dei sedimenti lacustri di pietrafitta (perugia, italia). pollen et spores, 33 (2), 325-328. ricciardi e., 1965 analisi polliniche di una serie stratigrafica dei sedimenti lacustri del pleistocene inferiore nel bacino di leonessa (rieti-italia centrale). giorn. bot. it., 7722, 62-82. rio d., channell j.e.t., bertoldi r., poli m.s., vergerio p.p., raffi i., sprovieri r. & thunnell r., 1997 pliocene sapropels in the northern adriatic area: chronology and paleoenvironmental significance. palaeogeogr., palaeoclimatol., palaeoecol. 135, 1-25. rio d., sprovieri r. & raffi i., 1984 calcareous nannofossil biostratigraphy of dsdp site 132 – leg 13 (tyrrhenian sea – western mediterranean). riv. it. paleont. strat., 8855, 127-172. rook l. & torre d., 1996 the wolf-event in western europe and the beginning of the late villafranchian. n. jb. geol. paläont. mh., 88, 495-501. ruddiman w.f., raymo m.e., martinson d.g., clement b.m. & backman j., 1989 pleistocene evolution: northern hemisphere ice sheets and north atlantic ocean. paleoceanography, 44 (4) 353–412. ruggieri g. & sprovieri r., 1997 a revision of italian pleistocene stratigraphy. geol. romana, 1166, 131-139. russo ermolli e., 1994 analyse pollinique de la succession lacustre pléistocène du vallo di diano (campanie, ital ie). annales de la societé géologique de belgique, 111177(2), 333-354. russo-ermolli e., 1999 vegetation dynamics and climate changes at camerota (campania, italy) at the pliocene-pleistocene boundary. il quaternario, 1122 (2), 207-214. 35 russo ermolli e., 2000 pollen analysis of the acerno palaeolacustrine succession (middle pleistocene, southern italy). geol. soc. london, special publication, 118811, 151-159. russo ermolli e. & cheddadi r., 1997 climatic reconstruction during the middle pleistocene: a pollen record from vallo di diano (southern italy). géobios, 3300 (6) 735–744. russo ermolli e., juvigné e., bernasconi s., brancaccio l., cinque a., lirer l., ozer a., santangelo n., 1995 le premier stratotype continental de quatre stades isotopiques successifs du pléistocène moyen pour le bassin méditerranéen septentrional: le vallo di diano (campanie, italie). c. r. acad. sci. paris, série iia,, 332211, 877– 884. sabato l., bertini a., masini f., albianelli a. napoleone g. & pieri p., in press the lower and middle pleistocene geological record of the san lorenzo lacustrine sequence in sant’arcangelo basin. (southern apennines, italy). quat. int. selli r., accorsi c.a., bandini mazzanti m., bertolani marchetti d., bigazzi g., bonadonna f.p., borsetti a.m., cati f., colalongo m.l., d' onofrio s., landini w., menesini e., mezzetti r., pasini g., savelli c. & tampieri r., 1977 the vrica section (calabria, italy). a potential neogene/quaternary boundary stratotype. giorn. geol., 4422, 181-204. sprovieri r., 1993 pliocene early pleistocene astronomically forced planktonic foraminifera abundances fluctuations and chronology of mediterranean calcareous plankton bioevents. riv. it. paleont. strat., 9999, 371-414 sprovieri r., thunell r. & howell m., 1986 paleontological and geochemical analysis of three laminated units of late pliocene-early pleistocene age from the monte san nicola section in sicily. riv. it. paleont. strat., 9922, 401-434. suc j.-p., 1986 florès néogènes de méditerranée occidentale. climat et paléogeographie. bull. centres rech. explor. – prod. elf-aquitaine, 1100 (2), 477-488. suc j.-p. & bessais e., 1990 pérennité d’un climat thermoxérique en sicile, avant, pendant et après la crise de salinité messinienne. c. r. acad. sci. paris, 331100 ser. ii, 1701-1707. suc j.-p., bertini a., combourieu-nebout n., diniz f., leroy s., russo-ermolli e., zheng z., bessais e. & ferrier j., 1995 structure of west mediterranean vegetation and climate since 5.3 ma. acta zoologica cracoviense, 3388 (1), 3-16. suc j.-p., fauquette s., bessedik m., bertini a., zheng z., clauzon g., suballyova d., diniz f., quezel p., feddi n., clet m., bessais e., bachiri taoufiq n., méon h. & combourieu-nebout n., 1999 neogene vegetation changes in west european and west circum-mediterranean areas. in "hominoid evolution and climatic change in europe, agusti j., rook l. & andrews p. eds., cambridge univ. press, 11, 378-388. thompson r. s., anderson k. h. & & bartlein p. j., 1999 atlas of relations between climatic parameters and distributions of important trees and shrubs in north america. usgs 1999, professional paper 1650 a&b, http://pubs.usgs.gov/pp/1999/p1650-a/. torre d., albianelli a., azzaroli a., ficcarelli g., magi m., napoleone g., & sagri m,. 1993 paleomagnetic calibration of the late villafranchian mammal faunas of the upper valdarno, central italy. mem. soc. geol. it., 4499, 335-344. torre d., albianelli a., bertini a., ficcarelli g., masini f. & napoleone g., 1996 paleomagnetic calibration of plio-pleistocene mammal localities in central italy. acta zoologica cracoviense, 39, 559-570. torre d., abbazzi l., bertini a., fanfani f., ficcarelli g., masini f., mazza p. & rook l., 2001 structural changes in italian late pliocene pleistocene large mammal assemblages. bol. soc. paleont. it., 4400 (2), 303-306. turner c., 1996 a brief survey of the early middle pleistocene in europe. in: c. turner (ed.), the early middle pleistocene in europe, balkema, rotterdam, pp. 295-317. vaiani s.c., 1996 micropaleontologia e stratigrafia isotopica dello stronzio nel pleistocene mediterraneo. unpublished phd thesis, university of bologna (italy). van couvering j., 1997 preface. in: van couvering. j.a., ed.: the plio-pleistocene boundary and the beginning of the quaternary. world and regional geology series, 99, xi-xvii. cambridge university press, 296 pp. van der wiel a.m. & wijmstra,t.a., 1987 palynology of the 112.8-197.8 m interval of the core tenaghi philippon iii, middle pleistocene of macedonia. rev. palaeobot. palynol., 5522, 89-117. van koenigswald w. & van kolfschoten t., 1996 the mimomys arvicola boundary and the enamel thickness quotient (sdq) of arvicola as stratigraphic markers in the middle pleistocene, in: c. turner (ed.), the early middle pleistocene in europe, balkema, rotterdam, 211–226. van otterloo r. & sevink j., 1983 the quaternary evolution of the upper–volturno basin. in: c. peretto, c. terzani, m. cremaschi (eds.), isernia la pineta, un accampamento più antico di 700 000 anni, calderini, bologna, 35–39. violanti d., 1991 i foraminiferi pliocenici di castel di sotto (novazzano, canton ticino): considerazioni biostratigrafiche e paleoambientali. boll. soc. tic. sc. natur., 7799 (1), 49-70. wang c.w., 1961 the forest of china with survey of grassland and desert vegetation – maria moors cabot foundation publication series, 55. harward university, cambridge, massachussetts. zagwijn w.h., 1963 pollen-analytic investigations in the tiglian of the netherlands. mededelingen geologische stichting, n.s., 1166, 49-71. zagwijn w.h., 1975 variations in climate as shown by pollen analysis, especially in the lower pleistocene of europe. in wright a. e. & moseley f. (eds), ice ages: ancient and modern, 137-152. zagwijn w.h. & jong j. de., 1984 die interglaziale von bavel und leerdam und ihre stratigraphische stellung im niederland-isschen früh-pleistozän. mededelingen geologische stichting, 3377,, 155-159. zijderveld j.d.a., hilgen f.j., langereis c.g., verhallen p.j.j.m. & zachariasse w.j., 1991 integrated magnetostratigraphy and biostratigraphy of the upper pliocene lower pleistocene from the monte singa and crotone areas in calabria, italy. earth planet. sci. lett., 110077, 697-714. 36 il tardoglaciale nelle alpi italiane e in pianura padana. evoluzione stratigrafica, storia della vegetazione e del popolamento antropico cesare ravazzi1, marco peresani2, roberta pini1, elisa vescovi1,3 1consiglio nazionale delle ricerche – istituto per la dinamica dei processi ambientali laboratorio di palinologia e paleoecologia cesare.ravazzi@idpa.cnr.it, roberta.pini@idpa.cnr.it 2università di ferrara dipartimento di biologia ed evoluzione sezione di paleobiologia, preistoria e antropologia marco.peresani@unife.it 3institute of plant sciences, university of bern elisa.vescovi@ips.unibe.ch riassunto: c. ravazzi, m. peresani, r. pini, e. vescovi, il tardoglaciale nelle alpi e in pianura padana. evoluzione stratigrafica, storia della vegetazione e del popolamento antropico. (it issn 0394-3356, 2007). viene presentato un quadro di sintesi dell’evoluzione stratigrafica e paleoambientale nel tardoglaciale (19 – 11,5 mila anni cal bp) e dei suoi rapporti con il popolamento antropico sul versante meridionale delle alpi e in pianura padana, basato su successioni stratigrafiche ad alta risoluzione e dotate di datazioni radiometriche. dopo il ritiro dei ghiacciai dagli anfiteatri pedemontani e dai grandi laghi prealpini, nella prima parte del tardoglaciale si verifica il collasso dei ghiacciai entro le vallate alpine, accompagnate da una intensa evoluzione dei fondovalle e dei versanti in ambiente paraglaciale. in questo intervallo, che registra le prime installazioni antropiche al piede delle prealpi, la vegetazione forestale era limitata alle aree stabili del settore pedemontano, agli anfiteatri deglaciati in corso di colonizzazione e alle aree prossimali della pianura, mentre i settori distali dei megaconoidi erano in attiva aggradazione. con l’inizio (14,5±0,2 mila anni cal bp) dell’interstadio di bølling –allerød, le foreste avanzarono rapidamente fino a 1700-1800 metri. gli effetti del riscaldamento sono rilevabili da un aumento di produttività dei sistemi lacustri e palustri nelle alpi. gli insediamenti epigravettiani si portano nella fascia montana delle alpi orientali. in conseguenza dei mutamenti ecologici durante gli interstadiali, ha inizio la colonizzazione epigravettiana delle prealpi e delle dolomiti e si verifica la diffusione di insediamenti differenziati per posizione altimetrica e orientamento funzionale. nella seconda parte dell’interstadio si diffusero latifoglie termofile. la culminazione di quest’ultima fase coincise con la deposizione del laacher see tephra (13 – 12,9 mila anni cal bp) e precedette di due secoli l’inizio del dryas recente, che pertanto appare sincrono con il centro-europa. gli effetti del dryas recente nel bacino padano sono riconducibili a condizioni climatiche continentali quasi semiaride, con stagioni molto contrastate. nella seconda metà del dryas recente inizia una fase complessa di avanzata dei ghiacciai (stadi di egesen, kartell, kromer), che interessa anche i primi due millenni dell’olocene. allo stato attuale, i dati archeologici non sono in grado di rilevare l’impatto del dryas recente sulle dinamiche insediative. abstract: c. ravazzi, m. peresani, r. pini, e. vescovi, the late glacial in the italian alps and in the po plain: stratigraphy, vegetation history and human peopling. (it issn 0394-3356, 2007). the palaeoenvironmental evolution and its relationship with the human peopling of the southern side of the alps, their foreland and the po plain during the lateglacial, i.e. the interval following the global last glacial maximum between 19 and 11.5 ka cal bp, is reconstructed on the base of high-resolution stratigraphic successions. after the major glaciers retreat from the pedemontane amphitheatres and from the great pre-alpine lakes, a collapse of the dendritic valley glaciers occurred during the first part of the lateglacial and well before the bølling –allerød interstadial. forest vegetation was limited to the foreland and the external belt of pre-alps, and did not enter the inner valleys, still subjected to intense paraglacial evolution. this period records the first human occurrences at the prealpine foothills. the onset of the bølling–allerød interstadial, dated 14.7 – 14.3 ka cal bp, allowed the treeline to reach 1700-1800 m a.s.l., promoted productivity in the lacustrine and palustrine systems, and peat formation commenced up to an altitude of 1800 m a.s.l. together with warming and reforestation, human settlements expanded in the eastern alps. as a consequence of the interstadial ecological modifications, the epigravettian colonization of the pre-alps and the dolomites starts. sites increase in number and differentiate in altitude and function. the second part of this interstadial is marked by the expansion of thermophilous broad-leaved trees, the peak of which coincided with the deposition of the laacher see tephra in lago piccolo di avigliana, dated 13 or 12.9 ka cal bp, and anticipated the beginning of the younger dryas by about two centuries. the yd onset, therefore, appears to be synchronous in northern italy and central europe. the yd in the po plain was characterized by continental dry climate, close to the semiarid regime, with strong seasonal contrast. during the second half of yd, a renewed glacial activity (egesen, kartell, and kromer stadials) is recorded in the high valleys. this glacial multiphase extends well into the early holocene. at the present state, the archaeological data are still unsufficient for revealing the possible impact of the yd on the settlement dynamics. parole chiave: stratigrafia, tardoglaciale, storia della vegetazione, popolamento umano, dryas recente, alpi, pianura padana. keywords: stratigraphy, lateglacial, vegetation history, alps, human peopling, younger dryas, po plain. il quaternario italian journal of quaternary sciences 20(2), 2007 163-184 1. introduzione la parte finale dell’ultima glaciazione che segue l’ultimo massimo glaciale (umg) è uno dei momenti più salienti della storia del paleoambiente alpino e padano e del popolamento preistorico dei territori montani, durante il quale si configura l’assetto moderno delle vallate alpine e di parte della pianura, e si sviluppano i biomi forestali che hanno caratterizzato l’ambiente naturale durante il presente interglaciale, prima delle modificazioni antropiche. durante questo intervallo, che si estende tra 19 e 11,5 mila anni cal bp e dura circa 8 millenni, si sono succeduti eventi brevi e bruschi e il paesaggio dell’italia settentrionale si è via via diversificato dando origine ad un complesso insieme di ambienti con il quale si sono relazionati i cacciatori-raccoglitori della fase recente del paleolitico superiore. per ottenere una scansione più 164 c. ravazzi et al. dettagliata possibile di questo complicato periodo è perciò importante disporre di una cronologia raffinata che consenta di svolgere correlazioni tra eventi climatici a scala regionale e di coglierne il rapporto con gli eventi bio-culturali. il presente contributo è inteso a presentare un quadro di sintesi aggiornato (lavori pubblicati fino all’anno 2007) dell’evoluzione stratigrafica, glaciale, vegetazionale delle alpi italiane e della pianura padana. la prima parte del lavoro prende in considerazione una serie di problemi di suddivisione e correlazione che si incontrano nelle indagini stratigrafiche sull’ultima transizione glaciale-interglaciale. la seconda parte esamina l’evoluzione del versante meridionale delle alpi e della pianura antistante, ma contiene anche richiami e spunti di indagine derivanti dal versante settentrionale alpino. sono di particolare utilità le conoscenze geocronologiche relative agli stadi glaciali tardoglaciali e alla struttura fine degli eventi climatici tardoglaciali della regione alpina, recentemente acquisite nelle alpi svizzere e austriache. le informazioni paleoclimatiche e paleovegetazionali provengono, in gran parte, da successioni polliniche ad alta risoluzione (= distanza cronostratigrafica media tra i campioni inferiore a 150 anni), e dotate di più datazioni radiometriche nell’intervallo corrispondente al tardoglaciale. datazioni radiometriche e isotopiche sono anche disponibili per gli stadi che individuano la posizione dei ghiacciai durante la deglaciazione e per le fasi di aggradazione dei megafan della pianura. a fronte di questi sviluppi nelle conoscenze sull’evoluzione paleogeografica e paleobiologica, si è tentato di interfacciare il quadro climatostratigrafico ed ecologico con le dinamiche comportamentali proprie al popolamento umano della regione in esame avvenuto nel corso dell’epigravettiano. i dati archeologici a riguardo di questo vasto fenomeno sono in continua acquisizione grazie a nuove scoperte e ad un rinnovamento concettuale e metodologico. la localizzazione dei siti selezionati per la ricostruzione stratigrafica e del popolamento è indicata in fig. 1. la tab. 1 contiene indicazioni bibliografiche per la consultazione delle informazioni di dettaglio relative a ciascun sito. le date sono sempre espresse in età calendario, calibrate secondo stuiver & reimer (19862005), e indicate come anni cal bp. in pochi casi vengono riportate anche età radiocarbonio (indicate come anni 14c bp). la nomenclatura botanica fa riferimento a pignatti (1982). 2. metodi e problemi nello studio dell’ultima transizione glaciale-interglaciale 2.1. gli archivi naturali util i per gli studi sul tardoglaciale gli archivi naturali continentali utili per la registrazione di eventi di durata decennale, secolare o millenaria devono essere caratterizzati da continuità stratigrafica, assenza di modificazioni post-deposizionali, alta risoluzione nella registrazione paleoclimatica e sensibilità alla variabilità inter e intra-annuale. questi archivi sono rappresentati da successioni lacustri (con i dati proxy costituiti da polline, isotopi stabili dell’ossigeno, varve, cronologia radiometrica), da calotte di ghiaccio (con i seguenti proxy: isotopi stabili dell’ossigeno e dell’idrogeno sull’acqua e i gas imprigionati, polveri, strati annuali di ghiaccio), da serie dendrocronologiche (isotopi stabili dell’ossigeno e del carbonio, cronologia radiocarbonica, anelli annuali di legno) e da speleotemi (isotopi stabili dell’ossigeno e del carbonio, isotopi radiogenici, cronologia radiometrica, lamine di crescita annuale, elementi in traccia, luminescenza uv attivata da molecole organiche). nella regione alpina è ampiamente diffuso lo studio di successioni lacustri e palustri, che abbondano nelle regioni glacializzate a partire dall’ultima deglaciazione (fig. 1). anche gli archivi dendrocronologici tardoglaciali sono significativi sul versante meridionale delle alpi (fig. 1), poichè diverse conifere erano già presenti a partire dall’inizio della deglaciazione (ravazzi et al., 2004). lo studio degli speleotemi tardoglaciali delle prealpi sud-orientali è stato avviato con successo nell’ultimo decennio (frisia et al., 2005). depositi fluviali, fluvioglaciali, alluvionali e di versante presentano tassi di accumulo molto variabili e scarsa continuità stratigrafica, ma, se accompagnati da accurate datazioni radiometriche, il loro studio consente di riconoscere gli effetti degli eventi climatici su svariati processi attivi durante la deglaciazione (fontana et al., 2004). più difficile la datazione di depositi glaciali riferibili agli stadi tardoglaciali, per la scarsità di vegetazione nelle vallate al tempo della deglaciazione. il quadro cronostratigrafico resta maldefinito, anche se da diversi anni si stanno affinando tecniche di datazione tramite isotopi cosmogenici (10be) che datano il tempo intercorso dalla stabilizzazione di erratici su morene (ivy-ochs et al., 2007) e luminescenza su depositi sabbiosi proglaciali (klasen et al, 2007). 2.2. il tardoglaciale: definizione e limiti il termine tardoglaciale – che è una traduzione dell’inglese lateglacial indica il complesso di eventi che hanno caratterizzato la transizione climatica tra l’ultima culminazione glaciale dell’ultima glaciazione e l’inizio dell’interglaciale attuale, cioè dell’olocene. i l l imite cronostratigrafico superiore del tardoglaciale è definito in maniera precisa e univoca da un brusco e vistoso evento di aumento della temperatura globale, ben riconoscibile in quasi tutti gli archivi naturali dell’emisfero nord del pianeta, datato 11,57 mila anni cal bp nelle successioni di anelli degli alberi dell’europa centrale (friedrich et al., 1999) e 11,6±0,24 mila anni cal bp (gisp2) ovvero 11,55±0,90 mila anni (grip) nelle successioni di ghiaccio (dansgaard et al, 1989). l’età radiocarbonica corrispondente (10 mila anni 14c bp) è stata assunta come limite cronostratigrafico pleistocene / olocene nella scala del tempo geologico internazionale (gradstein et al, 2004). al contrario il limite inferiore del tardoglaciale non è segnato da un episodio climatico altrettanto brusco ed evidente con cui far iniziare l’ultima deglaciazione del pleistocene. inoltre è ben noto che l’ultima deglaciazione non è avvenuta con modalità sincrone nelle diverse aree glacializzate del pianeta. attualmente sono in uso tre diverse definizioni per il limite inferiore del tardoglaciale (fig. 2): 165il tardoglaciale nelle alpi ... fig. 1 ubicazione geografica delle località citate nel testo. sono stati scelti i siti di maggiore rilevanza per la ricostruzione della storia del tardoglaciale delle alpi italiane e della pianura padana, in quanto dotati di una cronologia radiometrica o cosmogenica affidabile. area in grigio chiaro: rilievo oltre 200 m s.l.m. triangoli: siti di interesse paleoglaciologico. 1 – argentera; 2 – aletschgletscher; 3 – julier pass; 4 – gschnitz. cerchi pieni: successioni lacustri, fluviali e di torbiera. 5 – lago piccolo di avigliana; 6 – lago di alice superiore; 7 – lago di viverone; 8 – leysin; 9 – regenmoos; 10 – gerzensee; 11 – soppensee; 12 – rotsee; 14 – lago di ganna; 15 – lago di origlio; 16 – lago di annone; 17 – moso di crema; 18 – paleolago e torbiera di cerete; 19 – paleolago / torbiera del pian di gembro; 20 – lago lucone; 21 – torbiera del passo del tonale; 22 lago di ledro; 23 – totenmoos; 24 – lago di lavarone; 25 – depositi fluviali di bubano; 27 – depositi fluviali e palustri di forli; 28 – depositi fluviali e palustri di rimini; 29 – laghi di revine; 30 – paleolago / torbiera di palughetto di cansiglio; 32 – depositi fluviali e di torbiera di bannia; 33 – lago di ragogna. quadrati: siti di interesse dendrocronologico e speleotemi. 5 – avigliana; 13 – dättnau, svizzera; 29 – cava presso laghi di revine; 30 – palughetto di cansiglio; 34 – grotta savi. aree barrate: alcuni dei grandi corpi sedimentari in formazione durante il tardoglaciale in pianura padana. 26 – megafan di bassano; 31 – megafan del cellina. asterischi: distribuzione dei siti epigravettiani tardoglaciali di maggiore importanza nel trentino – alto adige, veneto e friuli. le alpi centro occidentali non dispongono di un insieme altrettanto rilevante e pertanto sono state omesse dalla figura. a riparo soman; b riparo tagliente; c riparo la cogola; d – altopiano dei fiorentini e malga campoluzzo di mezzo; e val lastari; f riparo battaglia; g riparo dalmeri; h – le viotte del monte bondone; i terlago; l andalo; m le regole; n ripari villabruna; o pian dei laghetti; p riparo tschonstoan; q bus de la lum e palughetto; r busa di villotta e pian delle more; s grotte verdi di pradis e grotta del clusantin; t riparo di biarzo. location of sites mentioned in the text. only successions relevant for the reconstruction of the late glacial history in the italian alps and in the po plain were chosen, as they provide a reliable radiometric or cosmogenic chronology. light grey area: reliefs above 200 m triangles: sites of palaeoglaciological interest. 1 – argentera; 2 – aletschgletscher; 3 – julier pass; 4 gschnitz solid circles: lacustrine, fluvial and peat-bog successions. 5 – lago piccolo di avigliana; 6 – lago di alice superiore; 7 – lago di viverone; 8 – leysin; 9 – regenmoos; 10 – gerzensee; 11 – soppensee; 12 – rotsee; 14 – lago di ganna; 15 – lago di origlio; 16 – lago di annone; 17 – moso di crema; 18 – palaeolake and peat-bog of cerete; 19 – palaeolake / peat-bog of pian di gembro; 20 – lago lucone; 21 – peat-bog of passo del tonale; 22 lago di ledro; 23 – totenmoos; 24 – lago di lavarone; 25 – fluvial deposits of bubano; 27 – fluvial and palustrine deposits of forlì; 28 – fluvial and palustrine deposits of rimini; 29 – quarry near laghi di revine; 30 – palaeolake / peat-bog of palughetto di cansiglio; 32 – fluvial and peat-bog deposits of bannia; 33 – lago di ragogna. squares: sites of dendrochronological interest and speleothems. 5 – avigliana; 13 – dättnau, switzerland; 29 – quarry near laghi di revine; 30 – palughetto di cansiglio; 34 – grotta savi. dashed areas: some large sedimentary bodies formed during the late glacial in the po plain. 26 – megafan of bassano; 31 – megafan of the cellina river. asterisks: distribution of late glacial epigravettian sites of interest in trentino – alto adige, veneto and friuli. sites in the centralwestern alps are not shown in this figure, because they do not yield comparable evidences. a riparo soman; b riparo tagliente; c riparo la cogola; d – altopiano dei fiorentini and malga campoluzzo di mezzo; e val lastari; f riparo battaglia; g riparo dalmeri; h – le viotte del monte bondone; i terlago; l andalo; m le regole; n ripari villabruna; o pian dei laghetti; p riparo tschonstoan; q bus de la lum and palughetto; r busa di villotta and pian delle more; s grotte verdi di pradis and grotta del clusantin; t riparo di biarzo. 166 tab. 1 i siti impiegati per il presente studio (la numerazione fa riferimento alla fig. 1). sites selected for this study. numbering refers to figure 1. siti di interesse paleoglaciologico (depressione della linea di equilibrio dal ad 1850) 1 argentera federici et al., 2006 2 aletschgletscher 170-240 m kelly et al., 2004 3 julier pass ivy-ochs et al, 1999 4 gschnitz 700 m ivy-ochs et al., 2006 successioni lacustri, fluviali e di torbiera 5 lago piccolo di avigliana 353 m schneider, 1978; finsinger et al., 2006 6 lago di alice superiore 570 m schneider, 1978 7 lago di viverone 220 m schneider, 1978 8 leysin 1230 m wick, 2000 9 regenmoos 1260 m wick, 2000 10 gerzensee 603 m wick, 2000 11 soppensee 596 m lotter, 2001 12 rotsee 419 m lotter, 1990 14 lago di ganna 452 m schneider & tobolski, 1985 15 lago di origlio 416 m tinner et al., 1999 16 lago di annone 226 m wick, 1996 17 moso di crema 75 m deaddis et al., 2007; 18 cerete 458 m orombelli & ravazzi, 1995 19 paleolago/torbiera di pian di gembro 1350 m pini, 2002 20 lago lucone 249 m valsecchi et al., 2006 21 torbiera del passo del tonale 1883 m gehrig, 1997 22 lago di ledro 652 m beug, 1964 23 totenmoos 1718 m heiss et al., 2005 24 lago di lavarone 1100 m arpenti, inedito 25 depositi fluviali di bubano 12,5 m ravazzi et al., 2006 27 depositi fluviali e palustri di forlì aa.vv., 2005 28 depositi fliuviali e palustri di rimini aa.vv., 2005 29 laghi di revine 224 m casadoro et al, 1976; 30 paleolago / torbiera di palughetto di cansiglio 1040 m avigliano et al., 2000; vescovi, 2007 32 depositi fluviali e di torbiera di bannia 20 m donegana et al., 2005 33 lago di ragogna 188 m wick, 2006b siti di interesse dendrocronologico e speleotemi 5 avigliana 353 m friedrich et al., 1999 13 dättnau, svizzera ca. 400 m friedrich et al., 2001 29 cava presso i laghi di revine ca. 220 m friedrich et al., 1999; kromer et al., 1998 30 palughetto di cansiglio 1040 m friedrich, kromer, talamo, in corso 34 grotta savi 300-350 m frisia et al, 2005 alcuni grandi corpi sedimentari in formazione durante il tardoglaciale in pianura padana 26 megafan di bassano fontana et al., 2004 31 megafan del cellina fontana et al, 2004 siti epigravettiani tardoglaciali di maggiore importanza nel trentino-alto adige, veneto e friuli a riparo soman 110 m battaglia et al., 2002 b riparo tagliente 226 m fontana et al., 2002 c riparo la cogola 1070 m dalmieri, 2004 d fiorentini 1482 m bartolomei & broglio, 1967 d malga campoluzzo di mezzo 1400 m angelucci, 1995 e val lastari 1060 m broglio et al., 1992; peresani et al, in stampa f riparo battaglia 1050 m broglio, 1964 g riparo dalmeri 1240 m broglio & dalmeri, 2005; dalmeri & cusinato, 2005 h le viotte del monte bondone 1600 m bagolini & guerreschi, 1978 i terlago 414 m bagolini & dalmeri, 1983 l andalo 1039 m guerreschi, 1984 m le regole 1240m dalmeri et al., 2004 n ripari villabruna 500 m aimar et al., 1992 o pian dei laghetti 1488 m bagolini et al., 1984 p riparo tschonstoan 1870 m avanzini et al, 2002 q bus de la lum 995 m peresani et al., 1999-2000 q palughetto 1040 m di anastasio et al., 1995 r busa di villotta 1200-1300 m guerreschi, 1975 r pian delle more 1193 m duches et al., in stampa s grotte verdi e 515 m bartolomei et al., 1977 s grotta del clusantin 520 m peresani et al., in stampa t riparo di biarzo 165 m guerreschi, 1996 c. ravazzi et al. 167 fig. 2 schema della stratigrafia climatica del tardoglaciale in groenlandia e in europa centrale, dei principali vincoli cronologici disponibili e degli eventi vegetazionali documentati sul versante sud delle alpi. sono illustrate: fig. 2a la stratigrafia isotopica grip (cronologia ss09, johnsen et al., 1997; le barre orizzontali indicano intervalli di 100 anni); la cronologia e la suddivisione stratigrafica proposta da intimate (cronologia di bjorck et al., 1998); la cronologia e la stratigrafia delle successioni varvate dell’europa centrale (cronologia di litt et al., 2001); le serie dendrocronologiche (cronologia di friedrich et al., 2001; 2004). tra le due cronologie ss09 e intimate relative alla carota grip esistono discrepanze (evidenziate da tre livelli di correlazione). fig 2b (alpi) – le climatozone proposte nel presente lavoro; la successione di stadi glaciali definiti nelle alpi su base paleoglaciologica (maisch, 1982; ivy-ochs et al., 2006); i principali eventi vegetazionali documentati sul versante meridionale delle alpi. sono stati abbandonati i termini bühl e steinach, in base alle considerazioni di reitner (2007). il termine pleniglacial viene impiegato tuttora nella stratigrafia del pleistocene superiore dell’europa centrale (fig. 2a) per indicare l’intervallo (circa 60 mila anni) a dominanza di steppa e tundra artica che si sviluppa tra l’inizio dello stadio isotopico marino 4 e la riforestazione all’inizio dell’interstadio di bølling –allerød. pleniglacial ha un significato ambiguo nelle regioni centro-meridionali dell’europa. il suo impiego va perciò evitato. si sottolinea che le climatozone sono definite sulla base di biozone polliniche, la cui definizione non corrisponde ai criteri tempo-trasgressivi comunemente impiegati per la definizione di “zone polliniche di associazione”. si tratta invece di zone polliniche di abbondanza, i cui limiti fanno riferimento alle variazioni nelle proporzioni tra i tipi dominanti, causate da variazioni della paleoproduttività (vedi discussione nel cap. 2.7). si noti inoltre che l’oldest dryas (dryas più antico) in europa centrale è inteso come un episodio di breve durata all’interno dell’interstadio di bølling-allerød. la sua posizione cronostratigrafica non è univoca (vedi discussione nel testo). l’individuazione di stadi glaciali è basata sul calcolo dell’abbassamento della ela, cioè della linea di equilibrio dei ghiacciai, proprio di ciascuno stadio, e dei rapporti stratigrafici tra i depositi riferibili a ciascuno di essi. climatostratigraphic scheme for the late glacial, showing the main chronological constraints available and the vegetational events documented on the southern side of the alps. fig. 2a – isotopic stratigraphy from grip (ss09 chronology, johnsen et al., 1997; horizontal bars indicate intervals of 100 years); chronology and stratigraphic subdivision proposed by intimate (chronology after bjorck et al., 1998); chronology and stratigraphy of central european varved successions (chronology after litt et al., 2001); dendrochronological series (chronology after friedrich et al., 2001; 2004). between the two available grip chronologies (ss09 and intimate) there are discrepancies, evidenced by shifts in three selected correlation lines. fig. 2b (alps) – climatozones proposed in the present paper; the succession of glacial stages defined in the alps on a palaeoglaciological base (maisch, 1982; ivy-ochs et al., 2006); the main vegetation events documented on the southern side of the alps. the terms bühl and steinach were abandoned based on considerations by reitner (2007). the term pleniglacial is still used in the central european late pleistocene stratigraphy (fig. 2a) for the interval of about 60 thousand years dominated by steppes and arctic tundra constrained between mis 4 and the reforestation at the beginning of the bølling – allerød interstadial. in the central and southern regions of europe the term pleniglacial has an ambiguous meaning and its use has to be avoided. please note that the definition of climatozones is based on pollen biozones, the definition of which does not correspond to time-transgressive criteria used for pollen assemblage zones. they are indeed pollen abundance zones, the boundaries of which refer to changes in the ratio between dominant types, caused by palaeoproductivity changes (see discussion in chapter 2.7). please note that in central europe the oldest dryas is intended as a short-lived event inside the bølling-allerød interstadial. its chronostratigraphic position is not univocal (see discussion in the text). the recognition of glacial stages is based on calculation of ela (equilibrium line altitude of glaciers) lowering during each stage and of stratigraphic relationships between their deposits. il tardoglaciale nelle alpi ... 168 (i) il brusco evento di miglioramento climatico posto a 14,7 mila anni cal bp nel record isotopico della carota grip, che segna l’inizio del gi-1 (greenland interstadial 1) e a circa 12,4 mila anni 14c nelle successioni lacustri dell’europa centro-occidentale, che segna l’inizio dell’interstadio bøllingallerød. con questa accezione è stato usato ad esempio da johnsen et al. (1997), lowe & walker (1997), litt et al. (2003). (ii) il primo gradino di risalita della curva glacioeustatica del livello del mare, cioè l’inizio della deglaciazione a scala globale, ovvero il termine dell’ultimo massimo glaciale globale (umg, last glacial maximum), posto a 18-19 mila anni cal bp (lambeck et al., 2002). (iii) l’inizio della deglaciazione in una specifica area glacializzata. adottando il criterio (iii), basato sull’età della deglaciazione locale, si hanno diverse età per l’inizio del tardoglaciale. ad esempio: 15,8 -14,4 mila anni cal bp in scozia (birnie et al., 1993), e 17,5 mila anni cal bp in svizzera (preusser et al., 2003; preusser, 2004). d’altra parte il miglioramento climatico che segna l’inizio del gi-1 (14,7 mila anni cal bp) posticipa di quasi 4 millenni il termine dell’umg globale (18-19 mila anni cal bp). nel presente lavoro si impiegherà il criterio (ii), che fa iniziare il tardoglaciale al termine dell’umg globale, come indicato in orombelli et al. (2005). 2.3. criteri bioe climatostratigrafici per la suddivisione del tardoglaciale la suddivisione impiegata in europa centro-settentrionale fin dal 1930 era basata su criteri biostratigrafici, soprattutto l’identificazione di zone polliniche distinte sulla base delle trasformazioni subite dalla vegetazione sotto la pressione dei cambiamenti climatici e dei fattori ecologici (jessen, 1935). poiché i limiti delle zone polliniche sono spesso tempo-trasgressivi, mangerud et al. (1974, 1982) proposero una suddivisione in cronozone, che impiegava limiti arbitrariamente basati su età 14c multiple di 1000 o 500, ma che utilizzava gli stessi nomi assegnati a suo tempo alle zone polliniche. negli ultimi vent’anni, il confronto tra gli eventi bruschi individuati su base isotopica, pollinica e tefrostratigrafica nelle carote di ghiaccio in groenlandia, nell’oceano atlantico settentrionale e nelle successioni lacustri ad alta risoluzione in europa centrale ha portato all’abbandono di questa cronozonazione in favore di una divisione climatostratigrafica (björck et al., 1998, lowe, 2001; lowe et al., 2001; litt et al., 2003). il confronto tra gli archivi dell’europa centro-occidentale e settentrionale ha infatti evidenziato una successione di eventi climatici sostanzialmente sincroni nelle regioni artica e centro-europea (litt et al., 2003, fig. 2), anche se le stime di temperatura media e precipitazioni per ciascuna climatozona forniscono differenze regionali connesse con la circolazione atmosferica e forti gradienti causati dall’influenza della calotta glaciale della fennoscandia di spessore chilometrico (lowe et al., 1994). 2.4. tempo-trasgressività delle biozone e’ noto che la dinamica della vegetazione dipende solo in parte da fattori climatici: processi come la migrazione e l’espansione delle popolazioni forestali possono richiedere millenni, anche in assenza di perturbazioni climatiche. si veda l’esempio della storia dell’abete rosso nelle alpi, che è stato oggetto di vari studi recenti (ravazzi, 2002; ravazzi & pini, 2002; van der knaap et al., 2005; latalova & van der knaap, 2006). in breve, la migrazione dell’abete rosso inizia circa 14 mila anni fa nelle prealpi sud-orientali e, avanzando verso ovest, invade progressivamente l’intero arco alpino. in una parte delle alpi marittime l’abete rosso è arrivato dopo l’età romana, e, in alcuni territori, non è ancora giunto oggi. per queste ragioni la maggior parte delle zone polliniche di associazione, basate sull’espressione di processi ecologici, è tempo-trasgressiva e insoddisfacente per le finalità di correlazione cronostratigrafica (mangerud et al., 1974). un diverso approccio palinologico consiste nell’individuazione di zone polliniche di abbondanza, basata sulla valutazione della paleoproduttività. questa procedura ha altresì consentito di riconoscere gli effetti di eventi climatici anche brevi e rapidi e di dimostrarne il sincronismo in successioni a risoluzione annuale (litt et al., 2001, 2003). il presupposto è il seguente: poiché la produzione pollinica dipende dalle condizioni climatiche stagionali e dal numero di individui (cioè dalla loro biomassa), livelli stratigrafici caratterizzati da una brusca espansione di una popolazione di una specie, già precedentemente presente in una data località, ma limitata nella sua capacità di espansione da fattori climatici, possono segnalare un evento di natura climatica. la risposta della produttività di polline di una popolazione di angiosperme ad una variazione del clima è immeditata, tanto che il tasso annuale di deposizione di polline (pollen accumulation rate o pollen influx) viene impiegato per valutare comportamenti meteorologici di carattere stagionale (hicks, 2001). inoltre, l’incremento di una popolazione forestale indotta da una trasformazione climatica permanente può tradursi in un processo esponenziale che può essere modellato (magri, 1994). questi criteri consentono di impiegare le curve polliniche come proxy per l’individuazione di variazioni climatiche. i risultati di questa analisi possono essere testati mediante indagini multistratigrafiche, ad esempio correlando serie polliniche con serie di isotopi stabili dell’ossigeno e serie di chironomidi dallo stesso sito (magny et al., 2006). infine, il confronto tra diversi parametri paleoclimatici fornisce la base per la delimitazione di unità climatostratigrafiche (walker et al., 1999; ravazzi, 2003; walker, 2005), che saranno impiegate nel presente lavoro. si noti che il segnale pollinico delle popolazioni forestali, con le precisazioni sopra discusse, fornisce un criterio importante per la suddivisione climatostratigrafica. in base a queste considerazioni appare chiaro che, nei territori privi di alberi e/o di arbusti, l’individuazione di eventi climatici su base palinologica è più difficile. durante l’ultimo massimo glaciale e la prima metà del tardoglaciale, il versante nord-alpino rimase privo di vegetazione forestale (ammann et al., 1989), mentre numerose conifere e betulle sopravvissero al margine meridionale delle alpi (ravazzi et al., 2004). non sorprende quindi che le vicende biostratigrafiche relative a questo intervallo di tempo sono più articolate a sud delle alpi. 2.5. la suddivisione classica del tardoglaciale nei sistemi biostratigrafici centro-europei la storia oramai secolare della ricerca paleoecoc. ravazzi et al. logica sul tardoglaciale è stata condizionata da una visione nordica, dovuta prima alla formulazione e alla reiterazione della classica zonazione pollinica tardoglaciale tra la danimarca, la germania settentrionale e la svezia, tra 14,5 e 11,5 mila anni cal bp (jessen, 1935; iversen, 1954; menke, 1968; van geel et al., 1989), alla sua ridefinizione in cronozone (mangerud et al, 1974) e, di recente, alla sua reinterpretazione climatostratigrafica nelle carote di ghiaccio in groenlandia (walker, 1999; walker et al., 1999; fig. 2a). in questi schemi, il lateglacial inizia al termine del “pleniglacial”, circa 14,45 / 14,7 mila anni cal bp ed è suddiviso nella seguente successione di zone polliniche: (meiendorf), oldest dryas, bølling, older dryas, allerød, younger dryas. la validità della zona meiendorf (menke, 1968), accettata da litt et al. (2003) e nel presente lavoro (fig. 2a), non è accolta da altri, che la comprendono nel bølling (si veda de klerk, 2004). conseguentemente, la posizione cronostratigrafica dell’oldest dryas e dell’older dryas non è univoca: con lo stesso nome diversi autori hanno indicato eventi climatici diversi. tuttavia, in tutti i sistemi, oldest dryas e older dryas indicano eventi di breve durata che si verificano nella prima parte dell’interstadio con cui si conclude il “pleniglacial”. nel presente lavoro si impiegherà la seguente definizione climatostratigrafica: l’interstadio compreso tra il brusco miglioramento climatico evidenziato a 14,45 – 14,7 mila anni cal bp e il deterioramento climatico a 12,7 mila anni cal bp è complessivamente indicato come “interstadio di bølling –allerød” (fig. 2b). 2.6. l’età della deglaciazione nelle alpi e il problema dell’oldest dryas la correlazione tra la stratigrafia centro-europea e circumalpina ha evidenziato diverse difficoltà nomenclaturali e sostanziali, solo in parte oggi risolte. innanzitutto va sottolineato il forte anticipo della deglaciazione alpina rispetto alla fine del “pleniglacial” nell’europa centrale (sull’impiego di questo termine si veda la fig. 2). il ritiro dei ghiacciai alpini dagli anfiteatri pedemontani è datato tra 21 e 18 mila anni cal bp, sia in svizzera che in italia (ivy-ochs et al., 2004; van husen, 2004; monegato et al., 2007) e si sa che i principali laghi prealpini, situati all’interno degli anfiteatri, erano già sgombri dai ghiacciai circa 14,6 mila anni 14c bp, cioè circa 17,5 mila anni cal bp (lister, 1988; niessen & kelts, 1989). circa 19,5 – 19,3 mila anni cal bp il settore inferiore del ghiacciaio del piave, chiuso nella conca del vallone bellunese, stazionava ad una quota circa 100 m inferiore al massimo invaso raggiunto durante l’umg (pellegrini et al. 2005). datazioni sensibilmente più recenti per la deglaciazione degli anfiteatri e dei laghi pedealpini, spesso riportate anche nella letteratura più recente (bini et al., 2007), devono essere intese come età minime. tra l’inizio della deglaciazione delle valli alpine e l’interstadio di bølling –allerød corrono dunque circa 3500 anni che sono tuttora privi di una qualsiasi sistemazione cronostratigrafica. il problema è evidente nei bacini situati nelle aree pedemontane alpine e nella pianura padana, ove la sedimentazione non si è mai interrotta dopo il termine dell’umg (kaltenrieder et al, 2004; wick, 2006a; pini, ined.). nel presente lavoro questo intervallo è indicato come “prima parte del tardoglaciale”. durante questa fase il versante alpino settentrionale rimase totalmente privo di vegetazione forestale (lang, 1994), e sinora è stato possibile distinguere solo sottozone polliniche basate sulla vegetazione erbacea pioniera, steppica e camefitica (legnosa nana) che vi allignava (gaillard, 1984; ammann et al., 1989). in assenza di criteri biostratigrafici, l’oldest dryas è stato esteso indietro nel tempo fino alla base delle successioni lacustri nei bacini originati a seguito della deglaciazione alpina (ad es. zoller, 1960; welten, 1982). questa palese difformità rispetto al significato originario della biozona non è ancora stata corretta dagli autori che lavorano sul versante francese delle alpi e nel giura, dove si continuano a riproporre schemi privi di valore stratigrafico (ad es. magny et al., 2006). infatti, una biozona delimitata inferiormente su base litostratigrafica non è accettabile in base al codice internazionale di stratigrafia (salvador, 1994). l’impiego della biozona / climatozona oldest dryas va quindi evitato, almeno fintanto che non se ne dimostrerà l’effettiva correlabilità con le sezioni ad alta risoluzione del centro-europa. inoltre deve essere fatto uno sforzo per giungere ad una nuova biozonazione della prima metà del tardoglaciale nelle alpi. 2.7. problemi di visibilità e di variabilità del record archeologico nelle alpi, il grado di preservazione degli insediamenti paleolitici dipende dalle dinamiche dei fattori post-deposizionali, spesso responsabili di profonde riduzioni nelle categorie di reperti, limitate nella maggior parte dei casi alle sole industrie litiche (angelucci et al., 1995; angelucci & peresani, 2000). vi sono palesi difficoltà nella distinzione delle singole occupazioni antropiche soprattutto nei siti all’aperto, anche se resti di strutture abitative associate a testimonianze di attività economiche complesse possono essere rinvenuti nei suoli d’abitato dei ripari sottoroccia e delle cavità atriali. la possibilità di attribuire delle evidenze culturali ad una delle fasi dell’epigravettiano recente dipende anche dalla diversità nell’orientamento funzionale degli insediamenti. numerosi siti a predominante attività produttiva sono correlati alla vicinanza con giacimenti di selci, di campi temporanei di caccia con trattamento delle prede o vocati al trattamento di una più ampia gamma di materie prime animali e vegetali, di luoghi deputati a cerimonie. attività diverse producono insiemi litici diversi che alterano i rapporti strutturali tra le categorie principali di manufatti, fornendo da un lato indicazioni relative alla funzione (broglio, 1988-89; ziggiotti, 2005), ma vanificando la possibilità di formulare un’attribuzione crono-culturale del sito in assenza di elementi o di associazioni culturali diagnostiche. a questi problemi si aggiunge il fatto che, a fronte dell’elevato dettaglio di risoluzione raggiunto nella cronologia e nella paleoclimatologia del tardoglaciale e della variabilità del record archeologico, la periodizzazione dell’epigravettiano recente appare sempre più come uno strumento insufficiente nel supportare la ricostruzione delle dinamiche insediative e della loro evoluzione. nell’ultima quindicina di anni l’approccio allo studio del popolamento antropico è stato allargato prendendo in considerazione un’insieme di indicatori archeologici, peraltro ancora disomogeno, tra i quali si è recentemente inserita con efficacia la tecnologia litica. nello studio rivolto a riconoscere i diversi sistemi della produzione litica e ad individuarne gli obiettivi 169il tardoglaciale nelle alpi ... specifici, sia dal punto di vista delle tecniche e dei metodi applicati, sia in relazione alle scelte operate dagli epigravettiani, montoya (2004) e montoya & peresani (2005) ne hanno tracciato l’evoluzione nel corso del tardoglaciale correlandola ad importanti modificazioni nel modo di espressione dell'arte mobiliare. a questo contributo si sono aggiunte le scoperte di nuovi insediamenti e l’incremento nel numero di date radiocarbonio, venute a comporre nelle alpi orientali italiane un quadro di riferimento ricco di elementi che, per contro, si presenta decisamente più frammentario negli altri settori della catena. 2.8. l’epigravettiano tardoglaciale: criteri per la suddivisione il sistema di riferimento per l’attribuzione di fatti e di eventi culturali ed economici propri del periodo in esame porta a prendere in considerazione l’epigravettiano italico (laplace, 1966), un’entità culturale autonoma originatasi nel corso dell’ultimo glaciale dallo sviluppo del gravettiano e caratterizzata dalla persistenza di determinate tradizioni riconosciute nella tecnologia e, principalmente, nella tipologia delle industrie litiche. seppure si sia prestata anche una certa attenzione ad altri aspetti come l’evoluzione dell’arte e, recentemente, dei sistemi tecnici della produzione litica, attraverso il medesimo criterio è stata costruita la suddivisione di tale periodo, distinguendo un epigravettiano antico (tradizionalmente da 20 a 15 mila anni 14c bp) da un epigravettiano recente interamente compreso nel tardoglaciale (tradizionalmente da 15 a 10 mila anni 14c bp) caratterizzato quest’ultimo dalla differenziazione in facies regionali (palma di cesnola, 1993). nell’italia nord-orientale, dove il numero di insediamenti consente di costruire una sequenza di evoluzione culturale, la periodizzazione dell’epigravettiano recente si basa sulle variazioni delle caratteristiche tecnologiche delle industrie e tipologiche degli strumenti e delle armature litiche. la fase più antica viene riferita alla prima parte del tardoglaciale e rappresenta uno sviluppo dell’epigravettiano antico; la seconda fase riguarda l’interstadio bølling/allerød e il dryas recente; la terza fase cade sul limite tardoglaciale olocene, comprendendo forse anche una parte del preboreale. le ultime due fasi sono interessate da innovazioni che incidono sempre maggiormente sull’aspetto degli insiemi litici (broglio & improta, 1994-95). la diffusione di determinati strumenti come i grattatoi frontali corti, i coltelli a dorso curvo e diversi tipi di punte a dorso, trapezi, segmenti e triangoli tra le armature, l’affermazione stessa della tecnica del microbulino (peresani, 2006), modificano in maniera assai profonda lo strumentario epigravettiano condividendo questa evoluzione con altri complessi, sia epigravettiani dell’europa orientale e mediterranea, sia dell’europa occidentale atlantica e della grande pianura europea (djindjian et al., 1999). 3. il tardoglaciale: la storia nelle alpi e nella pianura padana 3.1. la prima parte del tardoglaciale (19/18 ca. 14,5 mila anni cal bp) le figg. 3 e 4 forniscono una sintesi delle informazioni palinostratigrafiche relative a quattro biozone climatozone del tardoglaciale riconosciute e correlate lungo il versante alpino meridionale (vescovi et al., 2007). le correlazioni discusse nelle figure non riguardano la parte iniziale del tardoglaciale (19/18 – 15,5 mila anni cal bp) per la quale non disponiamo ancora di un controllo cronologico sufficiente utile a correlare i siti lacustri di riferimento presenti in n-italia. per la storia della vegetazione, oltre ad avigliana (finsinger et al., 2006), è importante il sito di ragogna (wick, 2006b e ined.; monegato et al., 2007). entrambi questi siti sono dotati di 5-6 datazioni 14c ciascuna, eseguite su macroresti di piante terrestri, nell’intervallo 18 – 11,5 mila anni cal bp. per l’evoluzione fluviale vi sono approfondite informazioni cronostratigrafiche limitatamente alla pianura veneta (mozzi et al., 2006). le datazioni disponibili sulla storia della deglaciazione in gran parte riguardano il versante alpino settentrionale. sono stati presi in considerazione i siti epigravettiani con date radiocarbonio e ordinati sulla base della loro posizione altimetrica (tab. 2). essi rappresentano 170 12,00 12,25 12,50 12,75 13,00 13,25 13,50 13,75 14,00 14,25 14,50 14,75 15,00 15,25 15,50 15,75 16,00 16,25 16,50 16,75 17,00 17,25 p rim a p ar te d el t ar d og la ci al e in te rs ta d io d i b ol lin g d ry as a lle ro d r ec en te ka c al b p 22 6 r ip ar o t ag lie nt e 11 0 r ip ar o s o m an 16 5 r ip ar o d i b ia rz o 50 0 r ip ar o v ill ab ru na a 52 0 c lu sa nt in 51 5 g ro tt e v er d i d i p ra d is 99 5 b us d e la l um 10 60 v al l as ta ri 10 70 la c o g o la 12 40 r ip ar o d al m ie ri 12 40 le r eg o le tab. 2 distribuzione altitudinale delle date radiocarboniche per intervalli di 250 anni cal relative a siti epigravettiani dell’italia nord-orientale. distribution of radiocarbon ages along time-windows of 250 yrs. from epigravettian sites of northern italy along an altitudinal transect. see tab. 1 for references. c. ravazzi et al. una porzione minoritaria di un più vasto corpus dell’occupazione antropica del periodo, composto da numerosi siti montani, tuttavia privi di dati cronologici o di collocazione culturale incerta. 3.1.1. l’evoluzione glaciale e paraglaciale delle valli alpine dopo il collasso dei ghiacciai alpini nei settori di anfiteatro e dei grandi laghi (21 a 17,5 mila anni cal bp) si sono verificate riavanzate e stazionamenti, indicati come “stadi tardoglaciali” che hanno dato luogo ad apparati di deposizione glaciale via via più arretrati nelle valli alpine. maisch (1982) distingue nelle alpi svizzere interne gli stadi bühl, steinach, gschnitz, clavadel, daun, egesen. i primi due stadi sono stati descritti come fasi di riavanzata all’inizio della deglaciazione (penck & brückner, 1909), ma una recente revisione sedimentologica nell’area tipo indica una fase di accomodamento di corpi stagnanti di ghiaccio a seguito del collasso delle lingue e della reazione dei ghiacciai tributari, senza implicare un meccanismo climatico forzante (reitner, 2007). il termine “stadiale” non è quindi appropriato per queste prime fasi della deglaciazione (reitner, 2007, cfr. fig. 2). al contrario gli stadi successivi si sviluppano dopo la deglaciazione delle vallate e l’impostazione dei sistemi sedimentari vallivi proe paraglaciali (reitner, 2007). la collocazione cronologica di gschnitz, clavadel e daun resta problematica, perché la mancanza di vegetazione legnosa rende molto difficile la datazione radiocarbonica. lo stadio di gschnitz è stato datato con il metodo del 10be a 1615,5 ± 1,4 mila anni cal bp nell’area tipo (presso innsbruck, austria) e correlato con lo heinrich event 1 da ivy-ochs et al. (2006). questo dato smentisce una ipotetica correlazione con la parte iniziale dell’intersta171 fig. 3 sincronizzazione tra diagrammi pollinici sintetici relativi a cinque siti lacustri e palustri di riferimento per il tardoglaciale delle alpi italiane. in ordinata è riportata una coordinata cronologica (in anni calendario), ottenuta dal modello età profondità proposto da vescovi et al. (2007). e' indicata la posizione delle date 14c impiegate per la costruzione del modello e la rispettiva deviazione standard. a destra la stratigrafia isotopica grip, cronologia ss09. t = somma polline alberi; s = somma polline arbusti (soprattutto juniperus nel tardoglaciale e corylus nell'olocene); h = somma polline erbe e camefite (xerofite escluse); x = somma polline xerofite (comprendono: artemisia, hippophaë, chenopodiaceae, helianthemum). le piante erbacee acquatiche, palustri e di ambienti umidi sono escluse dalla somma pollinica, cioè sono escluse dal calcolo dei valori percentuali. il diagramma pollinico del lago di annone è troncato sotto una discontinuità stratigrafica tra la fine del dryas recente e l'inizio dell'olocene (da vescovi et al., 2007, con variazioni). synchronisation of synthetic pollen diagrams of five late glacial lacustrine and palustrine sites in the italian alps. y axes shows the chronology (calendar years) based on the depth-age model provided by vescovi et al. (2007). position of 14c ages used for the depthage model and standard deviations are shown. on the right: isotopic stratigraphic after grip, ss09 chronology. t = sum of tree pollen; s = sum of shrubs pollen (mainly juniperus in the late glacial and corylus in the holocene); h = sum of herbs and camephytes pollen (xerophytes excluded); x = sum of xerophytes (artemisia, hippophaë, chenopodiaceae, helianthemum). aquatic and wetland species are excluded from the pollen sum, i.e. they are not used for the calculation of the percentage values. the pollen diagram of lago di annone is cut below a stratigraphic discontinuity between the end of the younger dryas and the beginning of the holocene (modified after vescovi et al., 2007). il tardoglaciale nelle alpi ... 172 c. ravazzi et al. dio di bølling –allerød (van husen, 2004). morene frontali attribuite a questo stadio sono ampiamente distribuite sul versante alpino settentrionale, ad una quota di 800-1200 m s.l.m., mentre l’altitudine della linea di equilibrio (ela) è situata a 1900-2000 m s.l.m. (van husen, 1997). e’ stata proposta una correlazione tra lo stadio di daun e la climatozona older dryas (van husen 2004). secondo litt et al. (2001), la durata dell’older dryas è di 190 anni (fig. 2), mentre secondo friedrich et al. (2001) la sua durata dendrocronologica è di soli 20-25 anni, quindi troppo breve, se confrontato con il tempo di risposta di un grande ghiacciaio alpino. viceversa, secondo ivy-ochs et al. (2006, 2007) lo stadio di daun precede l’inizio dell’interstadio di bølling-allerød. in attesa di datazioni, si può collocare il daun tra 15,5 mila anni cal bp e l’inizio del dryas recente. questi dati indicano che gli stadi precedenti il daun si collocano nella prima parte del tardoglaciale, prima dell’inizio dell’interstadio di bølling-allerød. inoltre testimoniano che già 16-15,5 mila anni fa, le principali valli alpine e i versanti esposti a mezzogiorno fino ad oltre 2000 m s.l.m., non interessati da circhi, erano sgombri da ghiaccio. d’altra parte, durante tutta la prima parte del tardoglaciale che precede l’interstadio di bølling-allerød, la vegetazione forestale presentava una copertura trascurabile all’interno delle vallate oltre i 500 m s.l.m. (pini, 2002; heiss et al., 2005). da questo quadro emerge dunque che per alcune migliaia di anni, tra la deglaciazione del settore interno delle vallate (18-16 mila anni cal bp) e l’interstadio di bøllingallerød (14,7-14,3 mila anni cal bp), le vallate alpine rimasero in condizioni paraglaciali, soggette cioè a importanti processi di ridistribuzione, rimaneggiamento e aggiustamento di ingenti masse di sedimento. questa intensa attività, condizionata dalla persistenza dell’attività glaciale a monte, interessò sia il fondovalle (aggradazione di ambienti fluvioglaciali, alluvionali, deltizi e lacustri, talora seguita da rapida incisione nei bacini sospesi sulle valli principali), che il riequilibrio dei versanti (frane catastrofiche, sackungen, talus, rimaneggiamento di depositi glaciali). restarono esclusi dall’azione prevalente dei processi paraglaciali e periglaciali i settori esterni delle prealpi, isolati dai bacini glacializzati, e già occupati da vegetazione continua (praterie e arbusteti) fin dall’ultimo massimo glaciale. 3.1.2. il popolamento umano del primo tardoglaciale al primo tardoglaciale appartengono le prime marcate attestazioni di occupazione dei margini prealpini da parte degli epigravettiani. riparo tagliente nei monti lessini delinea i tratti salienti di sito a frequentazione ripetuta e complessa (fontana et al., 2002), dove stambecchi e bovidi rappresentavano le prede principali nell’economia di caccia (bartolomei et al., 1982). per quanto riguarda invece val lastari sull’altopiano di asiago, all’unica data riferita a questo intervallo non corrispondono prove certe riferibili ad un’occupazione antropica responsabile del consumo di combustibile legnoso. 3.1.3. la vegetazione forestale del margine alpino e l’oscillazione di ragogna la persistenza di conifere (larix decidua, pinus sylvestris, pinus mugo, pinus cembra, picea abies, juniperus sp.) e di alcune latifoglie (betula pendula, b. pubescens, alnus viridis, hippophaë rhamnoides, salix sp. div., rhamnus sp.) al termine dell’umg in pianura padana e al margine alpino orientale è sostenuta da macroresti e da dati palinologici quantitativi datati con il 14c (casadoro et al., 1976; ravazzi et al., 2004; monegato et al., 2007). nelle prealpi orientali è stato stimato un limite degli alberi (incl. pinus mugo) intorno a 700-800 m s.l.m. (ravazzi et al, 2004). bisogna però considerare che questo valore si riferisce a condizioni teoriche riscontrabili su superfici stabili, ma in realtà vaste aree erano soggette all’attività di processi di demolizione e deposizione. d’altra parte il tasso di afforestamento (ap, arboreal pollen) rilevato nelle successioni polliniche (ap = 30-50%) non è compatibile con l’esistenza di foreste, ma piuttosto suggerisce che nelle aree stabili fossero presenti formazioni a parco, caratterizzate da alberi distanziati, boscaglie e arbusteti xerofili, in rapporto ecotonale con steppe (a dominanza di gramineae, compositae, polygonaceae) e semideserti ad artemisia. concentrazioni elevate di microcarbone suggeriscono che gli incendi limitassero l’addensamento della vegetazione forestale (avigliano et al., 2000; pini, 2002; vescovi, 2007). nelle aree di anfiteatro liberate dai ghiacciai è evidente un progressivo aumento del tasso di afforestamento fin dalla prima parte del tardoglaciale, cioè un addensamento della vegetazione forestale pioniera nell’area deglaciata. intorno a 18 mila anni fa, nell’anfiteatro di avigliana (torino) erano insediate formazioni a 173 fig. 4 rappresentazione schematica delle percentuali polliniche cumulative medie relative a quattro finestre temporali per alcuni siti lacustri e palustri. piante legnose di foreste boreali (in blu): somma delle percentuali di pinus, picea, larix, juniperus, betula, alnus viridis, salix, vaccinium. xerofite (in giallo): artemisia, chenopodiaceae, ephedraceae, hippophaë. alberi e arbusti termofili (in rosso): quercus, tilia, ulmus, corylus, alnus glutinosa type, etc. erbacee terrestri (in verde): include anche le camefite (piante legnose nane) non xerofile. da ovest verso est i siti rappresentati sono: lago piccolo di avigliana (finsinger et al., 2006), lago di ganna (schneider & tobolski, 1985), lago di origlio (tinner et al., 1999), lago di annone (wick, 1996), paleolago / torbiera del pian di gembro (pini, 2002), lago di fimon (wick, 2006); depositi fluviali di bubano (ravazzi et al., 2006), paleolago / torbiera di palughetto di cansiglio (avigliano et al., 2000; vescovi et al., 2007). schematic representation along four time-windows of mean total pollen percentages concerning some lacustrine palustrine successions. woody species of boreal forests (in blue): sum of % of pinus, picea, larix, juniperus, betula, alnus viridis, salix, vaccinium. xerophytes (in yellow): artemisia, chenopodiaceae, ephedraceae, hippophaë. thermophilous trees and shrubs (in red): quercus, tilia, ulmus, corylus, alnus glutinosa type, etc. upland herbs (in green): including non-xerophylous camephytes (dwarf woody species). sites indicated from west to east are: lago piccolo di avigliana (finsinger et al., 2006), lago di ganna (schneider & tobolski, 1985), lago di origlio (tinner et al., 1999), lago di annone (wick, 1996), palaeolake / peat-bog of pian di gembro (pini, 2002), lago di fimon (wick, 2006); fluvial deposits of bubano (ravazzi et al., 2006), palaeolake / peat-bog of palughetto di cansiglio (avigliano et al., 2000; vescovi et al., 2007). il tardoglaciale nelle alpi ... ➧ betulle, larice e ginepro (lago piccolo di avigliana: finsinger et al, 2006); sui margini laterali dell’anfiteatro di ivrea vi erano boscaglie ad ontano verde, salix sp. e larice, mentre veri e propri lariceti erano insediati nella zona del lago di viverone (schneider, 1978). durante la prima metà del tardoglaciale, la betulla nana (betula nana), oggi assente in italia settentrionale, fece la sua comparsa nella vegetazione pioniera degli anfiteatri del settore occidentale del margine alpino italiano (avigliana: finsinger et al, 2006; ganna: schneider & tobolski, 1985), ma il record fossile di macroresti vegetali non si spinge avanti oltre l’inizio dell’interstadio di bølling –allerød, fatto salvo una sporadica ricomparsa nel dryas recente. questa specie, considerata il simbolo della vegetazione artica sospinta verso le alpi durante l’ultima glaciazione (lang, 1994), in realtà non è ancora stata rinvenuta in ital ia durante l’umg. probabilmente la sua immigrazione sul versante meridionale delle alpi segue la deglaciazione dell’altopiano svizzero, allorchè la distanza delle popolazioni pioniere insediate in quest’area, intorno a 16-15,5 mila anni cal bp (ammann et al., 1996) divenne compatibile con la capacità di dispersione della specie verso sud attraverso le alpi occidentali. negli anfiteatri più a est, intorno a 17,5-16,5 mila anni cal bp, vi sono formazioni a larice e pino mugo (anfiteatro del garda, lago di ledro: beug, 1964; lago lucone: valsecchi et al, 2006), pinete a bassa copertura e larici-cembreti negli anfiteatri dell’adda (lago di annone: wick, 1996). tra 17,2 e 16,1 mila anni cal bp, nell’anfiteatro di vittorio veneto e sulle colline circostanti si era insediata una foresta a parco di larice, con pino silvestre e pino mugo (laghi di revine: casadoro et al., 1976; kromer et al., 1998; friedrich et al., 1999, fig. 2). nell’anfiteatro del tagliamento sono presenti larici-cembreti (lago di ragogna: wick in monegato et al., 2007). nella successione lacustre di ragogna, all’espansione della foresta a parco durante i l primo tardoglaciale segue una fase di parziale arretramento (17 a 15,6 mila anni cal bp) che precede l’inizio dell’interstadio di bølling–allerød. e’ verosimilmente databile al medesimo contesto climatostratigrafico anche il seppellimento della foresta di revine da parte di depositi di versante, avvenuto subito dopo 16,1 mila anni cal bp. questa interruzione della successione forestale pioniera degli anfiteatri può essere attribuita ad una fase fredda, per la quale è stato indicato il nome di “oscillazione di ragogna” (monegato et al., 2007). di tale evento non abbiamo riscontro biostratigrafico sul versante settentrionale delle alpi, né tantomeno in europa centrale, ove a quel tempo non vi erano specie forestali. si nota, tuttavia, un possibile sincronismo con lo stadio di gschnitz (fig. 2). verso la fine del primo tardoglaciale, formazioni a parco di pini (pino silvestre, pino cembro, pino mugo) e larice sono insediate anche nel settore submontano delle alpi centro-orientali, almeno fino a 500 m s.l.m. (lago di origlio, mendrisiotto: tinner et al. 1999; lago di ganna, schneider & tobolski, 1985; paleolago di cerete, prealpi lombarde: orombelli & ravazzi, 1995; riparo tagliente: maspero, 1996). mughete estese in altitudine fino ad oltre 1050 m sono presenti nelle prealpi venete, trentine e friulane (paleolago di palughetto, cansiglio: avigliano et al., 2000, vescovi, 2007; lago di lavarone: arpenti, inedito). purtroppo non vi sono dati paleobotanici sulla vegetazione pioniera che presumibilmente occupava gli ambienti paraglaciali nei settori più interni delle alpi. 3.1.4. l’evoluzione della pianura padana al termine della prima parte del tardoglaciale, le superfici prossimali più elevate dei megaconoidi, costruite dai principali fiumi alpini e dagli scaricatori glaciali del settore centro-occidentale padano durante l’umg, sono già state abbandonate (calderoni et al., 1996; cremaschi & marchetti, 1995). il fiume adda aveva già iniziato ad incidere la parte intermedia del suo sandur fluvioglaciale sviluppato al termine del braccio di lecco (deaddis et al., 2007 e dati non pubblicati). nel settore orientale della pianura, nonostante le superfici prossimali a maggiore inclinazione dei conoidi fluvioglaciali siano state abbandonate e terrazzate al termine dell’lgm (megafan di bassano, fig. 1; mozzi et al., 2003), persiste l’aggradazione nei settori mediani e distali, come nel caso dei fiumi tagliamento e cellina (fig. 1, avigliano et al., 2002; fontana et al., 2004). in queste aree, ancora soggette alla divagazione di canali fluviali, abbondano le mughete (donegana et al., 2005). vi sono comunque differenze di comportamento anche tra corsi d’acqua adiacenti, in relazione alle caratteristiche dei bacini montani (avigliano et al., 2002; fontana et al. 2004). nel settore friulano, il processo di incisione generalizzata dei megaconoidi è sostanzialmente riferibile all’inizio dell’olocene (avigliano et al., 2002). nonostante il livello del mare abbia già intrapreso la sua risalita glacioeustatica (lambeck et al. 2002), il settore settentrionale dell’adriatico a nord di ancona è ancora occupato dalla terraferma. nel settore più basso della pianura veneta e friulana, inclusa la parte distale della pianura di ravenna e la parte superiore del territorio continentale del nord-adriatico, la parte antica del tardoglaciale è rappresentata dal caranto, una unità pedostratigrafica che testimonia la discontinuità deposizionale che separa la fase alluvionale e fluvioglaciale dell’umg e la trasgressione medio-olocenica (amorosi et al., 1999; serandrei barbero et al., 2001, aa.vv., 2005a). allo sviluppo del caranto nelle aree stabili si accompagna il comportamento erosivo dei fiumi, che incidono canali entro le piane alluvionali formate durante l’lgm. tuttavia, il settore intermedio della pianura reggiana, antistante il margine appenninico, è caratterizzato da condizioni di sedimentazione alluvionale. la piana del santerno è in attiva aggradazione ed è vegetata da pratelli effimeri pionieri su limi e sabbie, mentre la vegetazione fanerofitica (pinus sylvestris, picea, hippophaë) interessa le limitate aree stabili (ravazzi et al., 2006). le aree stabili sono ricoperte da foreste di conifere e miste con betulle (b. pendula; b. pubescens da accertare). queste condizioni perdurano anche durante l’interstadio di bølling –allerød. depositi palustri e di piana alluvionale, che abbracciano quasi tutto il tardoglaciale, sono stati individuati anche in altri siti della bassa pianura reggiana (fig. 1; aa.vv., 2005b). 3.2. l’interstadio di bølling-allerød (14,7/14,3-12,7 mila anni cal bp) negli archivi pollinici lacustri e palustri, dalla 174 c. ravazzi et al. pianura padana fino a oltre 2000 m di altitudine nelle alpi italiane, è ben rilevabile un brusco mutamento vegetazionale datato tra 12,26 e 12,4 mila anni 14c bp, ovvero 14,7 – 14,3 mila anni cal bp (fig. 3). in assenza di dati dendrocronologici e varvologici a risoluzione annuale, l’incertezza associata al dato radiometrico e alla calibrazione non consente di dimostrare se gli eventi datati nei diversi siti siano esattamente sincroni tra loro e con analoghi eventi registrati in europa centrale (litt et al., 2003). comunque le date 14c sono statisticamente indistinguibili e quindi è possibile riferirle ad un unico limite climatostratigrafico, che nel presente lavoro è indicato come inizio dell’interstadio di bølling –allerød. eventi associati all’inizio dell’interstadio sono: i) un forte aumento della paleoproduttività nei bacini lacustri-palustri, che segna l’inizio dell’accumulo di torba (peat initiation) e di altri sedimenti biogenici propri di acque lacustri aperte (gyttja) nella fascia montana e basso montana delle alpi, fino a 1800 m s.l.m. (avigliano et al., 2000; pini, 2002; vescovi, 2007). contestualmente si osserva una brusca diminuzione della componente terrigena e tassi di sedimentazione tra i più bassi (tipicamente 0.1-0.5 mm/anno) degli ultimi 18 mila anni. queste condizioni sono state osservate anche nei laghi svizzeri durante l’interstadio bølling –allerød (lister, 1988); ii) un brusco innalzamento del limite degli alberi, che si porta in qualche centinaio di anni a circa 1700 m s.l.m. siti significativi sono totenmoos, val d’ultimo (heiss et al, 2005) e il passo del tonale, a nord del massiccio dell’adamello (gehrig, 1997); iii) un aumento della densità forestale e diminuzione della frequenza di incendi, segnalati da valori del tasso di afforestamento oltre il 90% e da basse concentrazioni di microcarbone lungo tutto l’ampio range altitudinale compreso tra la pianura padana e oltre i 1350 m s.l.m. (sito di pian di gembro, pini, 2002). le foreste pedemontane presentano composizione variabile, con dominanza di pinus sylvestris, betula, juniperus, larix nelle alpi occidentali (finsinger et al., 2006) e di pinus sylvestris, larix, picea, betula, pinus mugo nelle alpi orientali (vescovi, 2007). nella seconda parte dell’interstadio, a partire da circa 13,5 mila anni cal bp, alcune latifoglie termofile (tilia sp., ulmus sp., quercus sp., fraxinus excelsior) si espandono sia nelle foreste della pianura padana che sui rilievi, formando boschi misti a dominanza più articolata in altitudine e per effetto di variazioni regionali edafiche e climatiche. qualche esempio (in ordine di dominanza nella copertura forestale stimata in base ai dati palinologici e macrobotanici): betula-pinus sylvestris-quercus (margine pedemontano piemontese, finsinger et al., 2006), pinus sylvestris-betula-larix-quercus (margine pedemontano lombardo, wick, 1996; gobet et al. 2000), pinus sylvestris-p. mugo-betula-tilia (margine pedemontano friulano, monegato et al. 2007), picea-quercus-tilia-larix (prealpi venete e friulane, 1000 m s.l.m., vescovi et al. 2007) e’ necessario precisare che non vi sono dati macrobotanici utili a chiarire quali specie dei generi ulmus e quercus siano coinvolte in questo processo di espansione delle latifoglie durante il tardoglaciale. per il genere tilia vi sono ritrovamenti di tilia cordata nella seconda parte dell’interstadio bølling –allerød al lago di ganna (schneider & tobolski, 1985). nella successione lacustre di avigliana è stato individuato il laacher see tephra (lst) che cade nella fase di massima espansione delle latifoglie termofile (finsinger et al., 2006). il lst è datato 12,9 mila anni cal bp sulla serie di varve del meerfelder maar (litt et al., 2003) e 13,2 – 13,01 mila anni cal bp in base a determinazioni radiocarboniche di precisione su serie dendrocronologiche (friedrich et al., 1999). in nessuno dei siti lacustri esaminati nel norditalia è stata sinora evidenziata la struttura fine dell’interstadio di bølling –allerød. complice il basso tasso di sedimentazione e la mancanza di siti a varve, non sono stati evidenziati gli eventi brevi e bruschi che ne scandiscono la sequenza climatostratigrafica nelle carote di ghiaccio in groenlandia (gi-1d, gi1b; walker et al., 1999) e nei laghi svizzeri (aegelsee, gerzensee: lotter et al., 1992; schwander et al, 2000). l’evento indicato nella letteratura centro-europea come older dryas è stato individuato nelle serie dendrocronologiche di avigliana e datato 14,1-14,12 mila anni cal bp (friedrich et al., 2001). secondo litt et al. (2001), la sua età sarebbe sensibilmente più recente (13,54-13,35 mila anni cal bp). queste ampie discrepanze potrebbero dipendere da diacronia regionale o dalla mancanza di accordo nella nomenclatura stratigrafica tra i diversi autori, che probabilmente indicano con lo stesso nome eventi diversi. sono attese novità dagli studi dendrocronologici sulla foresta fossile del palughetto (altopiano del cansiglio), ove sono conservati resti lignei accumulati durante gran parte dell’interstadio (m. friedrich, b. kromer, s. talamo, comunicazione personale). l’espansione forestale all’inizio dell’interstadiale registra l’inizio della penetrazione antropica nella fascia prealpina e nelle dolomiti meridionali, limitata tuttavia ai fondovalle e agli altipiani attorno ai 500 m di quota, dove i siti di riparo villabruna (aimar et al., 1992) e grotta del clusantin (peresani et al., in stampa) testimoniano a partire da 14,7 mila anni cal bp lo sfruttamento di bacini di caccia frequentati da ungulati e da marmotte, queste ultime oggetto anche di predazione specializzata. la colonizzazione dei territori al di sopra dei 1000 metri, cioè la fascia degli altipiani delle prealpi venete e friulane occidentali, si sviluppa in una fase successiva all’innalzamento del limite degli alberi, con un ritardo minimo di 400 anni (tab. 2). veicolato mediante insediamenti stagionali distribuiti tra i principali fondovalle e gli altipiani carsici fino a 1600 m di quota (con una punta a 1870 m) se si accetta l’attribuzione del riparo del tschonstoan sull’alpe di siusi (avanzini et al., 2002), questo fenomeno comporta l’esistenza di un sistema insediativo strutturato in siti complessi, talora deputati ad attività complementari, il cui modello di riferimento si basa sul nesso tra posizione altimetrica e orientamento economico e funzionale (per una recente sintesi vedi bertola et al., 2007). il modello considera i siti in fondovalle come campi oggetto di frequentazioni ripetute e di attività diverse, dove i dati archeozoologici attestano la prevalente predazione del 175il tardoglaciale nelle alpi ... cervo tra la primavera e l’autunno, e in minore misura degli altri ungulati con forte decremento di capridi e bovidi. lo spostamento altimetrico degli ecotoni e i conseguenti nuovi assetti nella distribuzione delle risorse sembrano favorire lo sfruttamento di un più ampio spettro di risorse da parte dei cacciatori-raccoglitori. i dati faunistici mostrano che la risalita stagionale in quota dei gruppi epigravettiani, se da un lato appare strettamente legata alle esigenze di una caccia specializzata allo stambecco nei mesi estivi e autunnali e al conseguente processamento delle prede, dall’altro evidenzia uno spiccato interesse verso una varietà più allargata di risorse biologiche (fiore & tagliacozzo, 2005; phoca-cosmetatu, 2005). a più larga scala, la diversificazione nell’economia alimentare implica per i gruppi umani fasi specifiche nelle attività del loro ciclo annuale, con l’acquisizione, il processamento e lo stoccaggio delle risorse ittiche o delle prede ornitologiche, o di mammiferi di piccola taglia. 3.3. il dryas recente nelle successioni poll iniche dell’ ital ia settentrionale l’interstadio di bølling –allerød è seguito da una progressiva flessione del tasso di afforestamento (ap) seguita da una lunga fase con valori stabilmente più bassi, correlata con il dryas recente. la migliore cronologia per la fase di declino delle latifoglie è fornita dalla successione di avigliana, ove sono disponibili date 14c e il lst, posto 8 cm sotto un brusco declino di quercus che segna l’inizio del dryas recente. in base al modello età-profondità proposto da finsinger et al. (2006), l’inizio del dryas recente è datato 12,7 mila anni cal bp, 200 anni dopo il lst. si noti che negli archivi a varve centro-europei il lst precede di 188198 anni l’inizio del dryas recente, posto a 12,68 mila anni cal bp (merkt & müller, 1999; litt et al., 2001) ovvero 192 anni nelle serie dendrocronologiche di dättnau, svizzera (friedrich et al., 2001, fig. 1). i dati di avigliana stabiliscono, pertanto, che l’inizio del dryas recente in europa centrale e in italia settentrionale è stato sincrono a scala decennale. inoltre la cronologia fine a varve dei laghi centro-europei ha dimostrato che anche il brusco inizio isotopico del dryas recente nelle carote di ghiaccio in groenlandia è sincrono (fig. 2). la flessione di ap (∆ap) è moderata nelle aree pedemontane padane (∆ap= -10%, cfr. lago di annone in fig. 4), mentre è più marcata nelle aree montane (pian di gembro, 1350 m s.l.m., ∆ap= -15÷20%). nel sito di totenmoos, 1718 m s.l.m., il lariceto interstadiale si ritira dal sito (completa scomparsa di stomi nel sedimento, ∆ap= -30%,) circa 12,5 mila anni cal bp, lasciando posto a praterie (non a brughiere) e vi si ristabilisce dopo 1100 anni circa, all’inizio dell’olocene (11,4 mila anni cal bp) (heiss et al., 2005). si può ritenere che l’abbassamento del limite degli alberi sia rimasto nell’ordine di 200-300 m. la produzione pollinica della componente forestale termofila della pianura padana e dei rilievi pedemontani (tilia, ulmus, quercus) subì un moderato decremento (fig. 4). viceversa, nell’anfiteatro del tagliamento e nelle basse prealpi orientali si verifica l’espansione di abete rosso (wick, 2006b, in stampa). dalla diminuzione di densità forestale si avvantaggiano artemisia e altre entità elio-xerofitiche proprie di praterie, steppe e arbusteti xerofitici (juniperus nelle aree pedemontane), mentre non reagiscono ericacee proprie di brughiera (rodoro-vaccinieti, brughiere ad erica). questa dinamica è tipica di climi continentali semiaridi, in cui si sviluppano ecotoni di foresta-steppa, e a forte insolazione (walter & breckle, 1986). durante il dryas recente e l’olocene antico, l’influenza orbitale della precessione determina valori di insolazione estiva massima alle medie latitudini rispetto agli ultimi 20 mila anni e condizioni di massimo contrasto stagionale, cioè una predisposizione verso climi continentali asciutti (berger & loutre, 1991). il tasso di accumulo di particelle di microcarbone resta stabile (tinner et al., 1999; pini, 2002). si può ritenere che la scarsità delle precipitazioni, gli incendi e l’effetto termico siano responsabili della flessione osservata nella densità forestale nelle aree di pianura. nelle successioni lacustri, la bassissima velocità di sedimentazione e la presenza di lacune di sedimentazione nella seconda metà del dryas recente (ad esempio al lago di annone, wick, 1997) nonché l’espansione di piante acquatiche e palustri (thalictrum, potamogeton, pediastrum) suggeriscono un abbassamento dei livelli lacustri. all’interno del dryas recente non si rilevano dinamiche vegetazionali significative, salvo una modesta e progressiva espansione di latifoglie termofile (quercus, tilia, ulmus, fig. 4) nella sua seconda metà, rilevabile nei siti pedemontani (avigliana, annone). alla sostanziale stabilità di questo intervallo si oppone una drammatica esplosione della vegetazione forestale termofila che viene associata al limite tra dryas recente e olocene. per questo evento in italia non disponiamo di datazioni radiometriche sufficienti a mostrarne il sincronismo regionale e a verificarne le relazioni cronologiche con analoghi eventi evidenziati dalla dendrocronologia in europa centrale e dallo studio di speleotemi nelle grotte del carso (frisia et al., 2005). tuttavia le modalità e la posizione stratigrafica del passaggio dryas recente – olocene sono compatibili con l’espressione di un evento di sensibile aumento della temperatura, sincrono nel bacino padano e di durata inferiore ai 50 anni (fig. 3), quindi paragonabile, per espressione climatostratigrafica, alla brusca terminazione del dryas recente che si osserva sia nelle registrazioni isotopiche delle carote di ghiaccio (dansgaard et al., 1989) che nello spessore degli anelli di accrescimento degli alberi (friedrich et al., 1999). l’impatto esercitato dal dryas recente sulla presenza antropica non è rilevabile allo stato attuale della ricerca. alcuni siti come bus de la lum, riparo la cogola, ripari villabruna e riparo soman tracciano una continuità insediativa epigravettiana nella fascia prealpina, sia in fondovalle dove attestano aumenti dei capridi nello spettro delle faune cacciate, che in quota dove documentano la predazione prevalente dei capridi e in minore misura dei cervidi (fiore & tagliacozzo, 2004). tale sistema viene proposto anche nella regione alpina interna e nell’area dolomitica, con insediamenti all’aperto collocati fino a 1500 metri che sembrano attestare una semplificazione delle attività economiche (inferite dallo studio delle industrie litiche) nel quadro di una maggiore mobilità residenziale (peresani & ziggiotti, in preparazione). 176 c. ravazzi et al. 3.4. evoluzione glaciale tra il dryas recente e l’inizio dell’olocene: lo stadio di egesen nelle alpi non sono noti depositi glaciali riferibili all’interstadio di bølling – allerød. presumibilmente i ghiacciai si attestarono su estensioni minori di quelle raggiunte durante lo stadio di egesen. i depositi conservati relativi a questa fase si sviluppano nella seconda metà del dryas recente ed hanno probabilmente cancellato le evidenze di possibili oscillazioni di minore entità (ivy-ochs et al., 2007). le culminazioni dello stadio di egesen sono state datate con il metodo del 10be e quindi correlate con la seconda metà del dryas recente e la prima metà del preboreale, sia nelle alpi svizzere che in quelle italiane occidentali (fig. 1; ivy-ochs et al., 1999; kelly et al., 2004; federici et al., 2006). sul ghiacciaio dell’aletsch, le misurazioni con il 10be hanno evidenziato che con il termine “stadio di egesen” sono state raggruppate morene di età diversa, compresa tra il dryas recente e la parte antica dell’olocene fino al boreale (kelly et al., 2004). ivy-ochs et al. (2007) hanno pertanto proposto di distinguere due stadi olocenici, dapprima inclusi nell’egesen: kartell (di possibile età preboreale) e kromer (forse boreale, evento 8,2 mila anni cal bp ? fig. 2b). e’ auspicabile che anche sul versante meridionale delle alpi sia riesaminata l’età delle morene tradizionalmente attribuite alla parte finale del pleistocene nella cartografia geologica (ad es. il “subsintema di bondo” in castellarin et al. 2005) con particolare riguardo al complesso di sedimenti glaciali riferiti all’egesen, di regola ricoperti da suoli podzolici bene evoluti, oppure immediatamente soggiacenti ai depositi dell’optimum climatico olocenico (porter & orombelli, 1985). anche nelle alpi italiane, infatti, i depositi torbosi antistanti i maggiori ghiacciai attuali e sbarrati da morene correlate con lo stadio egesen presentano alla loro base età posteriori all’inizio dell’olocene (ad es. gngfg cnr, 1986; speranza et al., 1996). la presenza di queste pulsazioni glaciali durante l’olocene antico suggerisce di evitare l’impiego formale del termine “postglaciale”, contrapposto a “tardoglaciale”, perché si tratta di un termine ambiguo (orombelli et al., 2005): da taluni è stato usato con significato climatostratigrafico (castellarin et al. 2005, p. 75), da altri con valore allostratigrafico (bini et al., 2004). 4. conclusioni l’analisi delle registrazioni climatostratigrafiche oggi disponibili nelle alpi italiane e nella pianura padana, con particolare riguardo a recenti studi ad alta risoluzione, ha consentito di delineare un quadro della storia dell’ambiente alpino e del pedemonte padano durante l’ultima transizione glaciale-interglaciale. in particolare sono state documentate le modalità del processo di riforestazione che accompagna la deglaciazione fin dall’inizio del tardoglaciale, 19 mila anni cal bp. le numerose datazioni radiometriche consentono di datare i principali eventi di mutamento degli ecosistemi forestali rispettivamente a 14,7-14,3, 12,7 e circa 11,5 mila anni cal bp. questi sono anche i momenti delle più brusche e più ampie transizioni climatiche, come già evidenziato sul versante svizzero delle alpi e confermato negli studi sugli speleotemi del carso. non sono ancora disponibili studi in grado di risolvere la struttura climatostratigrafica ad alto dettaglio nell’interstadio di bølling –allerød. gli eventi brevi che caratterizzano questo intervallo sono in parte conosciuti grazie agli studi dendrocronologici. la conoscenza delle oscillazioni glaciali è progredita, negli ultimi anni, grazie all’introduzione della geocronologia isotopica e di nuovi studi geologici sulle aree tipo ove sono stati descritti gli stadi glaciali nel secolo scorso. il quadro delle fasi stadiali si è notevolmente trasformato. l’identif icazione di stadi glaciali nell’olocene antico ha fatto crollare il paradigma che tuttora vede contrapposti tardoglaciale e “postglaciale” nella cartografia geologica delle alpi. tuttavia resta difficile studiare le relazioni tra avanzate glaciali e intervalli climatostratigrafici, perché l’incertezza delle datazioni numeriche è ancora molto elevata. nel settore assiale centro-occidentale della pianura del po le conoscenze sull’evoluzione paleoambientale e paleobotanica del tardoglaciale sono scarse, complice la scarsità di successioni lacustri e di datazioni radiometriche in ambiente alluvionale. la risposta in termini di strategie insediative, mobilità e sussistenza dei cacciatori-raccoglitori alle condizioni ambientali tardoglaciali appare complessa e diversificata. in maniera più o meno dettagliata, i contesti epigravettiani portano la testimonianza di modificazioni avvenute nel corso di questi circa 8 millenni a carico delle strutture economiche e forse sociali delle popolazioni epigravettiane. cambiamenti significativi rispetto al periodo precedente si manifestano nel grado di mobilità dei gruppi umani sotto forma di organizzazione dei sistemi insediativi, rottura spazio-temporale delle catene operative litiche e in materie dure animali, introduzione e stoccaggio delle materie prime nei siti, strategie di approvvigionamento, diversificazione dello spettro venatorio. nel contempo, i dati sembrano delineare lungo il tardoglaciale un’evoluzione dei sistemi di produzione e, di concerto, della struttura insediativa. vaste lacune restano ancora aperte soprattutto in determinati momenti chiave del periodo in esame, come la fase terminale dell’epigravettiano recente e una migliore cronologia della fase più antica inquadrata nei primi 3500 anni cal del periodo. sforzi ulteriori sono necessari per giungere ad una modellizzazione del popolamento antropico nelle sue fasi principali, attraverso la definizione del carico di biomassa vegetale e animale e in ottemperanza a criteri di optimal foraging theory. si auspica, per il futuro, l’elaborazione di un quadro climatostratigrafico e paleoambientale multidisciplinare più avanzato per la parte finale del pleistocene in nord italia, attraverso il confronto di serie di vari dati climatici proxies, nonché mediante nuovi studi paleoecologici. tuttavia la condizione prima per giungere a questa sintesi è un incremento delle conoscenze geocronologiche. ringraziamenti ringraziamo enrico arpenti, walter finsinger, willy tinner, verushka valsecchi, lucia wick e gli enti che li hanno sostenuti (institute of plant science, 177il tardoglaciale nelle alpi ... università di berna; c.n.r. idpa; università degli studi di milano; il fondo unico per la ricerca della provincia autonoma di trento-progetto oloambient) per il contributo palinologico da loro portato negli ultimi cinque anni alle conoscenze sulla storia della vegetazione e del clima nel tardoglaciale delle alpi italiane. ringraziamo inoltre stefano marabini (università di bologna) e mauro marchetti (università di modena) per i suggerimenti, donatella magri (università la sapienza, roma) e il secondo revisore anonimo per la revisione del manoscritto. ricerca svolta nell’ambito della commessa “paleoclimatologia”, modulo ta.p02.005.001 presso il cnr-idpa, unità di milano. bibliografia aimar a., alciati g., broglio a., castelletti l., cattani l., d'amico c., giacobini g., maspero a. & peresani m. (1992) les abris villabruna dans la vallèe du cismon preistoria alpina, 28 (1), pp. 227254. aa.vv. (2005a) carta geologica d'italia 1:50.000, fogli 240 forlì, 241 cervia. servizio geologico d'italia regione emilia-romagna. s.el.ca. firenze. aa.vv. (2005b) carta geologica d'italia 1:50.000, foglio 256 rimini. servizio geologico d'italia regione emilia-romagna. s.el.ca. firenze. ammann b., lotter a.f., eicher u., gaillard m.-j., wohlfarth b., haeberli w., lister g., maisch m., niessen f. & schlüchter c. (1989) the würmian late-glacial in lowland switzerland j. quat. sci., 9 (2), pp. 119-125. ammann b., gaillard m.j. & lotter a.f. (1996) switzerland in (berglund, birks, ralskajasiewiczowa, wright eds.): palaeoecological events during the last 15,000 years: regional synthesis of palaeoecological studies of lakes and mires in europe. wiley & sons, chichester. pp. 647-667. amorosi a., colalongo m.l. & fusco f. (1999) glacioeustatic control of continental-shallow marine ciclicity from late quaternary deposits of the southeastern po plain, northern italy quaternary research, 52, pp. 1-13. angelucci d.e. (1995) un nuovo sito paleolitico nelle prealpi venete: malga campoluzzo di mezzo (vicenza) preistoria alpina, 31, pp. 37-51. angelucci d.e., broglio a. & peresani m. (1995) a geoarchaeological approach to living floors: some remarks on palaeo-mesolithic sites of the south-eastern alps proceedings of the i international congress science and technology for the safeguard of cultural heritage in the mediterranean basin, cnr, pp. 1447-1457. angelucci d.e. & peresani m. (2000) the open-air sites of val lastari and malga lissandri (venetian prealps, northern italy): preliminary results on spatial analysis and the study of postdepositional processes atti del workshop scienze e archeologia. quaderni del civico museo storico-archeologico, savona, pp. 47-55. arpenti e. (inedito) studio palinologico delle successioni sedimentarie del lago di lavarone, lago nero di cornisello e lago caldonazzo relazione finale. rapporto interno cnr-idpa, 1/2006. avanzini m., broglio a., de stefani m., lanzinger m., lemorini c. & rossetti p. (2002) i l riparo tschonstoan sull’alpe di siusi seiser alm atti 33 riunione scientifica i.i.p.p., pp. 117-144. avigliano r., di anastasio g., improta, s., peresani m. & ravazzi c. (2000) a new late glacial early holocene paleobotanical and archeological record in the venetian pre-alps: the peat-bog of palughetto (cansiglio plateau) j. quat. sci., 15(8), pp. 789-803. avigliano r., calderoni g., monegato g. & mozzi p. (2002) the late pleistocene-holocene evolution of the cellina and meduna alluvial fans (friuli, ne italy) mem. soc. geol. it., 57, pp. 133-139. bagolini b. & dalmeri g. (1983) site paléolithique tardif – mésolithique du lac de terlago (trento) preistoria alpina, 19, pp. 189-196. bagolini b. & guerreschi a. (1978) notizie preliminari sulle ricerche 1977-78 nell’insediamento paleolitico delle viotte di bondone (trento) preistoria alpina, 14, pp. 7-31. bagolini b., ferrari a., lanzinger m. & pasquali t. (1984) pian dei laghetti – s.martino di castrozza preistoria alpina, 20, pp. 39-52. bartolomei g. & broglio a. (1967) il giacimento dei fiorentini sull’altopiano di tonezza – folgaria origini, i, pp. 11-36. bartolomei g., broglio a. & palma di cesnola a. (1977) chronostratigraphie et écologie de l’epigravettien en italie in (aa.vv.), la fin des temps glaciaires en europe chronostratigraphie et écologie des cultures du paléolithique final. actes colloque international c.n.r.s., pp. 297–234. bartolomei g., broglio a., cattani l., cremaschi m., guerreschi a., mantovani e., peretto c. & sala b. (1982) i depositi würmiani del riparo tagliente annali università di ferrara, n.s. sez. xv, 3, pp. 61-105. battaglia l., broglio a., castelletti l., lanzinger m. & maspero a. (1992) abri soman preistoria alpina, 28 (2), pp. 291-298. berger a. & loutre m.f. (1991) insolation values for the climate of the last 10 million years quat. sci. rev., 10, pp. 297-317. bertola s., broglio a., cassoli p.f., cilli c., cusinato a., dalmeri g., de stefani m., fiore i., fontana f., giacobini g., guerreschi a., gurioli f., lemorini c., liagre j., malerba g., montoya c., peresani m., rocci ris a., rossetti p., tagliacozzo a. & ziggiotti s. (2007) l’epigravettiano recente nell’area prealpina e alpina orientale in (martini f., a cura di), l’italia tra 15.000 e 10.000 anni fa. cosmopolitismo e regionalità nel tardoglaciale. millenni, studi di archeologia preistoria, 5, pp. 39-94. beug h.j. (1964) untersuchungen zur spätund postglazialen vegetationsgeschichte im gardaseegebiet unter besonderer berücksichtigung der mediterranen arten flora, 154, pp. 401-444. bini a., borsato a., carraro f., carton a., corbari d., cucato m., monegato g. & pellegrini g.b. (2004) definizione di alcuni termini in uso nella cartografia dei depositi quaternari continentali in ambito alpino il quaternario, italian journal of 178 c. ravazzi et al. quaternary sciences, 17, pp. 75-82. bini a., corbari d., falletti p., fassina m., perotti c.r. & piccin a. (2007) morphology and geological setting of iseo lake (lombardy) through multibeam bathymetry and high-resolution seismic profiles swiss j. geosci., 100, pp. 23-40. birnie j., gordon j.e., bennett k. & hall a.m., eds. (1993) the quaternary of shetland. quaternary research association, cambridge. björck s., walker j.c., cwynar c.l., johnsen s., knudsen k.l., lowe j.j., wohlfarth b. & intimate members (1998) an event stratigraphy for the last termination in the north atlantic region based on the greenland ice-core record: a proposal by the intimate group j. quat. sci., 13 (4), pp. 283292. broglio a. (1964) il riparo "raffaello battaglia" presso asiago rivista di scienze preistoriche, xix, pp. 129174. broglio a. (1988-89) possibilità di interpretazione funzionale di squilibri strutturali di sistemi litici origini, xiv, pp. 647-652. broglio a. (1992) mountain sites in the context of the north-east italian upper paleolithic and mesolithic preistoria alpina, 28 (1), pp. 293-310. broglio a. & dalmeri g. (a cura di) (2005) pitture paleolit iche nelle prealpi venete: grotta di fumane e riparo dalmeri. atti del simposio memorie museo civico di storia naturale di verona, ii serie, sezione scienze dell’uomo, 9, pp. 106-115. broglio a. & improta s., (1994-95) nuovi dati di cronologia assoluta del paleolitico superiore e del mesolitico del veneto, del trentino e del friuli atti istituto veneto scienze, lettere arti, cliii, pp. 1-45. broglio a., castelletti l., frigo g., martello g., maspero a. & peresani m. (1992) le site epigravettien de val lastari preistoria alpina, 28 (1), pp. 207-225. calderoni g., castiglioni g.b., foddai d., gallo s., lombardo m., miola a. & zangheri p. (1996) palaeoenvironmental features of a peri-euganean (padua, northern italy) depression during the late-quaternary: first results il quaternario, italian journal of quaternary sciences, 9, pp. 667670. casadoro g., castiglioni g.b., corona e., massari f., moretto m.g., paganelli a., terenziani f. & toniello v. (1976) un deposito tardowürmiano con tronchi subfossili alle fornaci di revine (treviso) boll. com. glac. ital., 24, pp. 22-63. castellarin a., dal piaz g.v., picotti v., selli l., cantelli l., martin s., montresor l., rigatti g., prosser g., bollettinari g., pellegrini g.b., carton a. & nardin m. (2005) note illustrative della carta geologica d’italia alla scala 1:50.000. foglio 059 – tione di trento. provincia autonoma di trento, trento. cremaschi m. & marchetti m. (1995) changes in fluvial dynamics in the central po plain (italy) between lateglacial and early holocene. in (frenzel b. ed.): palaeoclimate research, paläoklimaforschung, 14, pp. 173-190. dalmeri g. (a cura di) (2004) studi sul riparo la cogola, carbonare di folgaria – trento. frequentazione umana e paleoambiente preistoria alpina, 40, pp. 99-105. dalmeri g. & cusinato a. (a cura di) (2005) studi sul riparo dalmeri (grigno – trento). ritualità e frequentazione umana preistoria alpina, 41, pp. 161-255. dalmeri g., kompatscher k., hrozny kompatscher m., bassetti m., cusinato a. & piazzi o. (2004) dinamiche comportamentali degli ultimi cacciatori-raccoglitori in area alpina. il caso di studio del sito lr3 del laghetto delle regole (castelfondo, trento) preistoria alpina, 40, pp. 5-26. dansgaard w., white j.w.c. & johnsen s.j. (1989) the abrupt termination of the younger dryas climate event nature, 339, pp. 532-534. de klerk p. (2004) confusing concepts in lateglacial stratigraphy and geochronology: origin, consequences, conclusions (with special emphasis on the type locality bollingso) review paleobot. palynol., 129, pp. 265-298. deaddis m., donegana m., pini r., ravazzi c., wick l., de amicis m., marchetti m. & monegato g. (2007) the onset of the last glacial maximum in northern italy: chronostratigraphical and palaeoecological evidences from alluvial plain and lacustrine successions geophysical research abstracts, 9, p. 11648. di anastasio g., mondini c., peresani m. & villabruna a. (1995) altopiano del cansiglio. scavi di siti paleolitici e mesolitici quaderni archeologia del veneto, xi, pp. 11-18. djindjian f., kozlowski j.k. & otte m. (1999) le paléolithique supérieur en europe. colin ed. paris. donegana m., fontana a., paiero g. & ravazzi c. (2005) le torbe tardiglaciali di bannia – palazzine di sopra: palinologia e ricostruzione ambientale. in (a cura di visentini p.): bannia – palazzine di sopra. quaderni del museo archeologico del friuli occidentale, 5, pp. 15-18. duches r., peresani m. & ziggiotti s. (in stampa) nuovi dati sul popolamento antropico delle prealpi carniche nel tardoglaciale. il sito di pian delle more sul piancavallo rivista di scienze preistoriche, lvii. federici p.r., granger d., pappalardo m., ribolini a., spagnolo m. & cyr a.j. (2006) egesen stage moraine dated in the western alps by means of cosmogenic beryllium-10 inqua-seqs 2006 “quaternary stratigraphy and evolution of the alpine region in the european and global framework”. milano. abstract volume, p. 94. finsinger w., tinner w., van der knaap w.o., ammann b. (2006) the expansion of hazel (corylus avellana l.) in the southern alps: a key for understanding its early holocene history in europe? quat. sci. rev., 25 (5-6), pp. 612-631. fiore i. & tagliacozzo a. (2004) riparo cogola: il contesto paleoecologico e lo sfruttamento delle risorse animali tra epigravetiano e mesolitico antico in (dalmeri g., a cura di): studi sul riparo cogola (carbonare di folgaria). frequentazione umana e paleoambiente. preistoria alpina, 40, pp. 159-186. fiore i. & tagliacozzo a. (2005) lo sfruttamento delle risorse animali nei siti di altura e di fondovalle nel tardiglaciale dell’italia nord-orientale in (malerba 179il tardoglaciale nelle alpi ... g. & visentini p. a cura di): atti del 4° convegno nazionale di archeozoologia. quaderni del museo archeologico del friuli occidentale, 6, pp. 97-109. fontana f., guerreschi a. & liagre j. (2002) riparo tagliente. la serie epigravettiana in (aspes a., a cura di), preistoria veronese. contributi e aggiornamenti. memorie del museo civico di storia naturale di verona, ii serie, sez. scienze dell’uomo, 5, pp. 42-47. fontana a., mozzi p. & bondesan a. (2004) l’evoluzione geomorfologica della pianura venetofriulana in (a cura di bondesan a., meneghel m.): geomorfologia della provincia di vicenza. esedra, padova. pp. 113-138. friedrich m., kromer b., kaiser k.f., spurk m., hughen k.a. & johnsen s.j. (2001) high-resolution climate signals in the bølling / allerød interstadial (greenland interstadial 1) as reflected in european tree-ring chronologies compared to marine varves and ice-core records quat. sci. rev., 20, pp. 1223 – 1232. friedrich m., kromer b., spurk m., hofmann j. & kaiser k.f. (1999) palaeo-environment and radiocarbon calibration as derived from late glacial / early holocene tree-ring chronologies quat. int., 61, pp. 27-39. friedrich m., remmele s., kromer b., hofmann j., spurk m., kaiser k.f., orcel c. & küppers m. (2004) the 12,460-year hohenheim oak and pine treering chronology from central europe — a unique annual record for radiocarbon calibration and paleoenvironment reconstructions radiocarbon, 46 (3), pp. 1111–1122. frisia s., borsato a., spötl c., villa i.m. & cucchi f. (2005) climate variability in the se alps of italy over the past 17000 years reconstructed from a stalagmite record boreas, 34, pp. 445-455. gaillard m.-j. (1984) etude palynologique de l’évolution tardi et postglaciaire de la végétation du moyen-pays romand (suisse) diss. bot., 77, 322 pp. gehrig r. (1997) pollenanalytische untersuchungen zur vegetationsund klimageschichte des val camonica (norditalien) diss. bot., 276, 148 pp. gngfg cnr (1986) ricerche geomorfologiche nell’alta val di peio (gruppo del cevedale) geogr. fis. dinam. quat., 9, pp. 137-191. gobet e., tinner w., hubschmid p., jansen i., wehrli m., ammann b. & wick l. (2000) influence of human impact and bedrock differences on the vegetation history of the insubrian southern alps – veg. hist. archaeobot, 9, pp. 175-187. gradstein f.m., ogg j.g., smith a.g., bleeker w. & lourens l.j. (2004) a new geologic time scale with special reference to precambrian and neogene. episodes, 27 (2), pp. 83-100. guerreschi a. (1975) l'epigravettiano di piancavallo (pordenone) preistoria alpina, 11, pp. 255-293. guerreschi a. (1984) il sito epigravettiano di andalo (trento) ed alcune considerazioni sull’epigravettiano finale nel nord italia preistoria alpina, 20, pp. 15-38. guerreschi a. (a cura di) (1996) il sito preistorico del riparo di biarzo (valle del natisone, friuli) edizioni del museo friulano di storia naturale, 39, pp. 1-144. heiss a.g., kofler w. & oeggl k. (2005) the ulten valley in south tyrol, italy: vegetation and settlement history of the area, and macrofossil record from the iron age cult site of st. walburg palyno-bulletin of the institute of botany, university of innsbruck, 1-2, pp. 63-73. hicks s. (2001) the use of annual arboreal pollen deposition values for delimiting tree-lines in the landscape and exploring models of pollen dispersal review paleobot. palynol., 117, pp. 1-29. iversen j. (1954) the late-glacial flora of denmark and its relation to climate and soil danm. geol. unders., series ii, 80, pp. 87-119. ivy ochs s., schäfer j., kubik p.w., synal h.a. & schlüchter c. (2004) the timing of deglaciation in the northern alpine foreland (switzerland) ecl. geol. helv., 97, pp. 47-55. ivy-ochs s., kerschner h., kubik p.w. & schlüchter c. (2006) glacier response in the european alps to heinrich event 1 cooling: the gschnitz stadial j. quat. sci., 21 (2), pp. 115-130. ivy-ochs s., kerschner h. & schlüchter c. (2007) cosmogenic nuclides and the dating of lateglacial and early holocene glacier variations: the alpine perspective quat. int., 164–165, pp. 53–63. ivy-ochs s., schlüchter c., kubik p.w. & denton g. (1999) moraine exposure dates imply synchronous younger dryas advances in the euporean alps and in the southern alps of new zealand geografiska annaler, 81a (2), pp. 313-324. jessen a. (1935) beskrivelse til geologisk kort over danmark kortbladet haderslev. d.g.u. i.r., pp. 17. johnsen s.j., clausen h.b., dansgaard w., gundestrup n.s., hammer c.u., andresen u., andersen k.k., hvidberg c.s., dahl-jensen d., steffensen d., shoji j.p., sveinbjornsdottir a.e., white j.w.c., jouzel j. & fischer d. (1997) the _18o record along the greenland ice core project deep ice core and the problem of possible eemian climate instability j. geophys. res., 102, pp. 2639726410. kaltenrieder p., ammann b., ravazzi c. & tinner w. (2004) long-term forest dynamics during the past 26,000 years at colli euganei (near padova, italy) in: climate change, impacts on terrestrial ecosystems. 2nd international nccr climate summer school, grindelwald, 30 aug.-6 sept. 2003. kelly m.a., kubik p.w., von blanckenburg f. & schlüchter c. (2004) surface exposure dating of the great aletsch glacier egesen moraine system, western swiss alps, using the cosmogenic nuclide 10be j. quat. sci., 19, pp. 431-441. klasen n., fiebig m., preusser f., reitner j.m. & radtke u. (2007) luminescence dating of proglacial sediments from the eastern alps quat. int., 164–165, pp. 21–32. kromer b., spurk m., remmele s., barbetti m. & toniello v. (1998) segments of atmospheric 14c change as derived from late glacial and early holocene floating tree-ring series radiocarbon, 40 (1), pp. 351-358. 180 c. ravazzi et al. lambeck k., yokoyama y. & purcell t. (2002) into and out of the last glacial maximum: sea-level change during oxygen isotope stages 3 and 2 quat. sci. rev., 21, pp. 343-360. lang g. (1994) quartäre vegetationsgeschichte europas. fischer verlag, jena. laplace g. (1966) recherches sur l’origine et l’évolution des complexes leptolithiques école française rome, pp. 4. latalowa l. & van der knaap w.o. (2006) late quaternary expansion of norway spruce picea abies (l.) karst. in europe according to pollen data quat. sci. rev., 25, pp. 2780–2805. lister g.s. (1988) a 15,000-year isotopic record from lake zürich of deglaciation and climatic change in switzerland quat. res., 29, pp. 129-141. litt t., schmincke h.u. & kromer b. (2003) environmental response to climatic and volcanic events in central europe during the weichselian lateglacial quat. sci. rev., 22, pp. 7-32. litt t., brauer a., goslar t., merkt j. balaga k., muller h., ralska-jasiewiczova m., stebich m. & negendank j.f.w. (2001) correlation and synchronisation of the lateglacial sequences in northern central europe based on annually laminated lacustrine sediments quat. sci. rev., 20, pp. 12331249. lotter a.f., eicher u., siegenthaler u. & birks h.j.b. (1992) late-glacial climatic oscillations as recorded in swiss lake sediments j. quat. sci., 7 (3), pp. 187-204. lotter a.f. (2001) the palaeolimnology of soppensee (central switzerland) as evidenced by diatom, pollen, and fossil-pigment analyses journal of paleolimnology, 25, pp. 65-79. lotter a.f. (1990) die entwicklung terrestrischer und aquatischer ökosystemen rotsee (zentralschweiz) im verlauf der letzten 15000 jahre mitteilungen der naturforschenden gesellschaft luzern, 31, pp. 81-97. lowe j.j. (2001) abrupt climatic changes in europe during the last glacial-interglacial transition: the potential for testing hypotheses on the synchroneity of climatic events using tephrochronology global and planetary change, 603, pp. 73-84. lowe j.j., hoek w. & intimate group (2001) interregional correlation of palaeoclimatic records for the last glacial-interglacial transition: a protocol for improved precision recommended by the intimate project group quaternary science reviews, 20, pp. 1175-1187. lowe j.j. & walker m.j.c. (1997) reconstructing quaternary environments. 2nd ed. prentice hall, halow. lowe j.j., ammann b., birks h.h., björck s., coope g.r., cwynar l.c., de beaulieu j.-l., mott r.j., peteet d.m. & walker m.j.c. (1994) climatic changes in areas adjacent to the north atlantic during the last glacial-interglacial transition (14-9 ka bp) j. quat. sci., 9, pp. 185-198. magny m., aalvergsberg g., bégeot c., benoit-ruffaldi p., bossuet g., disnar j.-r., heiri o., laggoundefarge f., mazier f., millet l., peyron o., vanniere b. & walter-simonnet a.-v. (2006) environmental and climatic changes in the jura mountains (eastern france) during the lateglacialholocene transition: a multi-proxy record from lake lautrey quat. sci. rev., 25, pp. 414-445. magri d. (1994) late-quaternary changes of plant biomass as recorded by pollen-stratigraphical data: a discussion of the problem at valle di castiglione, italy review palaeobot. palynol., 81, pp. 313-325. maisch m. (1982) zur gletscher-und klimageschichte des alpinen spätglazials geographica helvetica, 37, pp. 93-104. mangerud j. (1982) the chronostratigraphic subdivision of the holocene in norden; a review striae, 16, pp. 65-70. mangerud j., anderson s.t., berglund b.e. & donner j. (1974) quaternary stratigraphy of norden, a proposal for terminology and classification boreas, 3, pp. 109-128. maspero a. (1996) dati sulla vegetazione del periodo glaciale: antracologia dei siti paleolitici del nord italia il quaternario, italian journal of quaternary sciences, 9 (2), pp. 591-598. menke b. (1968) das spätglazial von glüsing. ein beitrag zur kenntnis der spätglazialen vegetationsgeschichte in westholstein eiszeitalter und gegenwart, 19, pp. 73-84. merkt j. & muller h. (1999) varve chronology of lateglacial in northwest germany from lacustrine sediments of the hamlsee/lower saxony quat. int., 61, pp. 41-59. monegato g., ravazzi c., donegana m., pini r., calderoni g. & wick l. (2007) evidence of a two fold glacial advance during the last glacial maximum in the tagliamento end moraine system (se alps) quaternary research, 68, pp. 284-302. montoya c. (2004) les traditions techniques à l’epigravettien: analyses de séries du tardiglaciaire entre alpes et méditerranée thése de doctorat, directeur prof. r. chenorkian, université de provence (aix-marseille i). montoya c. & peresani m. (2005) premiers éléments de diachronie dans l’epigravettien récent des préalpes de la vénétie in (bracco j.p. & montoya c. eds.) d’un monde à l’autre. les systèmes lithiques pendant le tardiglaciaire autour de la méditerranée nord-occidentale. actes de la table ronde. mémoire de la societé préhistorique française, xl, pp. 123-138. mozzi p., bini c., zilocchi l., becattini r. & lippi m.m. (2003) stratigraphy, palaeopedology and palynology of late pleistocene and holocene deposits in the landward sector of the lagoon of venice (italy), in relation to the caranto level il quaternario, italian journal of quaternary sciences, 16 (1bis), pp. 193-210. mozzi p., fontana a. & bondesan a. (2006) stratigraphy and paleopedology of the post-lgm unconformity in the venetian-friulian plain inqua-seqs meeting 2006, volume of abstract, pp. 22-23. niessen f. & kelts k. (1989) the deglaciation and holocene sedimentary evolution of southern perialpine lake lugano implications for alpine paleoclimate eclogae geol. helv., 82 (1), pp. 235-263. orombelli g. & ravazzi c. (1995) le torbe di cerete 181il tardoglaciale nelle alpi ... basso (bergamo): una successione stratigrafica di riferimento per il tardiglaciale e l'olocene nelle prealpi lombarde rend. ist. lomb. sci. lett. arti, serie b, 129, pp. 185-217. orombelli g., ravazzi c. & cita m.b. (2005) osservazioni sul significato dei termini lgm (umg), tardoglaciale e postglaciale in ambito globale, italiano ed alpino il quaternario, italian journal of quaternary sciences, 18 (2), pp. 147-155. palma di cesnola a. (1993) il paleolitico superiore in italia. firenze. pellegrini g.b., albanese d., bertoldi r. & surian n. (2005) la deglaciazione alpina nel vallone bellunese, alpi meridionali orientali geogr. fis. dinam. quat., suppl. vii, pp. 271-280. penck a. & brückner e. (1909) die alpen im eiszeitalter. dritter band. die eiszeiten in den sudalpen und im bereich der ostabdachung der alpen. leipzig. peresani m., montoya c. & ziggiotti s. (in stampa) i campi epigravettiani di val lastari. studio sulla produzione litica, le attività venatorie e la trasformazione dei material i di un sito al l’aperto sull’altopiano dei sette comuni preistoria alpina, numero speciale. peresani m. (2006) cultures et traditions du paléolithique supérieur dans les régions nordméditerranéennes in (sanchidrian torti j.l., marquez a.ma. & fullola y pericot j.ma. eds.) la cuenca mediterránea durante el paleolítico superior (38.000-10.000 años). iv simposio de prehistoria cueva de nerja. fundación cueva de nerja, pp. 408-429. peresani m., bertola s., de stefani m. & di anastasio g. (1999-2000) bus de la lum and the epigravettian occupation of the venetian pre-alps during the younger dryas rivista di scienze preistoriche, l, pp. 103-132. peresani m., de curtis o., duches r., gurioli f., romandini m. & sala b. (in stampa) grotta del clusantin, un sito inusuale nel sistema insediativo epigravettiano delle alpi italiane in (mussi m. a cura di) il tardiglaciale in italia. lavori in corso. origini. phoca-cosmetatu n. (2005) landscape use in northeast italy during the upper palaeolithic preistoria alpina, 41, pp. 23-49. pignatti s. (1982) flora d’italia. edagricole, bologna. pini r. (2002) a high-resolution late-glacial holocene pollen diagram from pian di gembro (central alps, northern italy) veg hist archaeobot, 11 (4), pp. 251-262. porter s.c. & orombelli g. (1985) glacier contraction during the middle holocene in the western italian alps: evidence and implications geology, 13, pp. 296-298. preusser f. (2004) towards a chronology of the late pleistocene in the northern alpine foreland boreas, 33, pp. 195-210. preusser f., geyth m.a. & schlüchter c. (2003) timing of late pleistocene climate change in lowland switzerland quat. sci. rev., 22, pp. 14351445. ravazzi c. (2002) late quaternary history of spruce in southern europe review palaeobot. palynol., 120 (1-2), pp. 131-177. ravazzi c. (2003) an overview of the quaternary continental stratigraphic units based on biological and climatic events in italy il quaternario, italian journal of quaternary sciences, 16 (1bis), pp. 1118. ravazzi c. & pini r. (2002) the late-glacial and earlymiddle holocene spruce expansion in the eastern and central alps: a discussion and new data razprave iv sazu, ljubljana, 43 (2), pp. 189-211. ravazzi c., orombelli g., tanzi g. & climex group (2004) an outline of the flora and vegetation of adriatic basin (northern italy and eastern side of the apennine) during the last glacial maximum in (antonioli f. & vai g.b. eds.): litho-paleoenvironmental maps of italy during the last two climatic extremes. explanatory notes. 32nd international geological congress, firenze, pp. 15-20. ravazzi c., donegana m., vescovi e., arpenti e., caccianiga m., kaltenrieder p., marabini s., mariani s., pini r., vai g.b. & wick l. (2006) a new lateglacial site with picea abies in the northern apennine foothills: an exception to the model of glacial refugia of trees veget. hist. archaeobot., 15, pp. 357-371. reitner j.m. (2007) glacial dynamics at the beginning of termination i in the eastern alps and their stratigraphic implications quat. int., 164-165, pp. 64-84. salvador a. ed. (1994) international stratigraphic code second ed. the geological society of america, boulder. schneider r. (1978) pollenanalytische untersuchungen zur kenntnis der spätund postglazialen vegetationsgeschichte am südrand der alpen zwischen turin und varese (italien) bot. jahrb. syst., 100 (1), pp. 26-109. schneider r. & tobolski k. (1985) lago di ganna – late-glacial and holocene environments of a lake in the southern alps diss. bot., 87, pp. 229-271. schwander j., eicher u. & ammann b. (2000) oxygen isotopes of lake marl at gerzensee and leysin (switzerland), covering the younger dryas and two minor oscillations, and their correlation to the grip ice core palaeogeogr. palaeoclimatol. palaeocol., 159, pp. 203-214. serandrei barbero r., lezziero a., albani a. & zoppi u. (2001) depositi tardo-pleistocenici nel sottosuolo veneziano: paleoambienti e cronologia i l quaternario, ital ian journal of quaternary sciences, 14 (1), pp. 9-22. speranza a., ravazzi c., baroni c., carton a., van geel b., mommersteeg h. & orombelli g. (1996) holocene evolution and human impact in central alps: the pian venezia paleobotanical record (trento, italy) il quaternario, italian journal of quaternary sciences, 9 (2), pp. 737-744. stuiver m. & reimer p. (1986-2005) calib radiocarbon calibration program. version 5.0. disponibile al calib website. tinner w., hubschmid p., wehrli m., ammann b. & conedera m. (1999) long-term forest fire ecology and dynamics in southern switzerland j. ecol., 87, pp. 273-289. valsecchi v.,·tinner w.,·finsinger w. &·ammann b. 182 c. ravazzi et al. (2006) human impact during the bronze age in the vegetation at lago lucone (northern italy) veg hist archaeobot., 15, pp. 99-113. van der knaap w.o., van leeuwen j.f.n., finsinger w., gobet e., pini r., schweizer a., valsecchi v. & ammann b. (2005) migration and population expansion of abies, fagus, picea, and quercus since 15000 years in and across the alps, based on pollen-percentage threshold values quat. sci. rev., 24, pp. 645–680. van geel b., coope g.r. & van der hammen t. (1989) palaeoecology and stratigraphy of the lateglacial type section at usselo (the netherlands) review palaeobot. palynol., 60, pp. 25-129. van husen d. (1997) lgm and late-glacial fluctuations in the eastern alps quat. int., 38/39, pp. 109-118. van husen d. (2004) quaternary glaciations in austria in (elhers j., gibbard p.l. eds.), quaternary glaciations extent and chronology – part i: europe. elsevier, amsterdam. vescovi e. (2007) long-term population dynamics of major forest trees under strongly changing climatic conditions tesi di dottorato di ricerca, università di berna e di milano bicocca. pp. 104. vescovi e., ravazzi c., arpenti e., finsinger w, pini r; valsecchi v., wick l., ammann b. & tinner w. (2007) interactions between climate and vegetation during the lateglacial period as recorded by lake and mire sediment archives in northern italy and southern switzerland quaternary science reviews, 26 (11-12), pp. 1650–1669. walker m.j.c. (1999) rapid climate change during the last glacial-interglacial transition; implications for stratigraphic subdivision, correlation and dating global planet. change, 30, pp. 59-72. walker m. (2005) quaternary dating methods wiley, chichester walker m.j.c., björck s., lowe j.j., cwynar l.c., johnsen s., knudsen k.l., wohlfarth b. & intimate group (1999) isotopic “events” in the grip ice core: a stratotype for the late pleistocene quat. sci. rev., 18, pp. 1143-1150. walter h. & breckle s.w. (1986) ecological systems of the geobiosphere. 3: temperate and polar zonobiomes of northern eurasia springer, berlin. welten m. (1982) vegetationsgeschichtl iche untersuchungen in den westlichen schweizer alpen; bern-wallis denkschriften der schweizerischen naturforschenden gesellschaft, 95. wick l. (1996) late-glacial and early-holocene palaeoenvironments in brianza, n italy i l quaternario, ital ian journal of quaternary sciences, 9 (2), pp. 653-660. wick l. (1997) spätund postglaziale vegetationsgeschichte in den südalpen zwischen comersee und splügenpass (norditalien) phd thesis. university of bern. wick l. (2000) vegetational response to climatic change recorded in swiss lateglacial lake sediment palaeogeography, palaeoclimatology, palaeoecology, 159(3), pp. 231-250. wick l. (2006a) fullto late-glacial vegetation and climate changes and evidence of glacial refugia in the south-eastern alps (italy) in (colombaroli d., kaltenrieder p., vescovi e., tinner w., eds.): xxx international moor-excursion 2006. northern and central italy. università di berna. pp. 53-55. wick l. (2006b, in stampa) note illustrative della carta geologica d’italia alla scala 1:50.000. foglio udine presidenza del consiglio dei ministri, dipartimento difesa del suolo. udine. ziggiotti s. (2005) tecnologia e funzione. apporto dell’analisi funzionale delle industria l it iche dell’epigravettiano recente nelle prealpi orientali italiane tesi di dottorato di ricerca in scienze antropologiche, tesi di dottorato di ricerca, xvii ciclo. zoller h.(1960) pollenanalytische untersuchungen zur vegetationsgeschichte der insubrischen schweiz denkschriften der schweizerischen naturforschenden gesellschaft, band lxxxiii, abh. 2. 183 ms. ricevuto il 24 luglio 2007 testo definitivo ricevuto il 9 ottobre 2007 ms. received: july 24, 2007 final text received: october 9, 2007 il tardoglaciale nelle alpi ... imp.giannandrea i depositi terrazzati affioranti nell’alta valle del fiume ofanto (foglio n. 451 “melfi”, appennino campano-lucano) paolo giannandrea dipartimento di geologia e geofisica, università di bari. riassunto: p. giannandrea, i depositi terrazzati affioranti nell’alta valle del fiume ofanto (foglio n. 451 “melfi”, appennino campano-lucano). it issn 0394-3356, 2004 nell’alta valle del fiume ofanto sono presenti a diverse quote superfici di modellamento fluviale, depositi terrazzati, coperture detritiche e depositi vulcanici. tutti questi terreni sono stati organizzati in uno schema stratigrafico, utilizzando un profilo morfostratigrafico rettificato. sono stati distinti 4 ordini di depositi terrazzati indicativi dell’evoluzione del bacino idrografico del fiume ofanto. il riconoscimento di prodotti vulcanici intercalati ai depositi alluvionali terrazzati ha permesso di proporre una correlazione con le principali unità vulcaniche del monte vulture (supersintemi di monte vulture e di monticchio). in particolare i depositi terrazzati più antichi (pleistocene medio), rinvenuti a quote più alte (terrazzi: ia, iia e ib), sono stati correlati con i supersintemi di monte vulture. i depositi terrazzati più recenti raggruppati nei sintemi di conza della campania (terrazzi: iib e iii) e del fosso dello stroppito (terrazzi: ic, iic e iiic) sono stati correlati con il supersintema di monticchio (pleistocene medio – superiore). il sintema di conza della campania comprende anche depositi vulcanici rilevati in località casa rossa e riferibili ad un centro eruttivo delle ultime fasi di attività del monte vulture (sintema dei laghi di monticchio, età 132±12 ka). depositi vulcanici più recenti correlabili, per età (40.7±8.4 ka) e per chimismo, all’eruzione flegrea dell’ignimbrite campana, sono stati individuati in località ripe del cavallo. questo quadro morfostratigrafico consente di arricchire le conoscenze paleogeografiche del bacino idrografico del fiume ofanto e delle relazioni tra il sistema alluvionale e l’attività vulcanica del vulture. abstract: p. giannandrea, the terraced deposits outcrop in the upper valley of ofanto river (foglio n. 451 “melfi” apennine campano-lucano). it issn 0394-3356, 2004 in the upper valley of ofanto river (north of monte vulture) at different heights, more shaped surfaces, terraced deposits, debris sheets and volcanic deposits are visible. a stratigraphic architecture is reconstructed, using a morphostratigraphic profile. the emerged scheme allows us to distinguish four terraced deposits, related to different evolution stages of the valley. the recognition of volcanic deposits, intercalated in the alluvial conglomerates, makes it possible to propose a correlation with the main volcanic units of monte vulture (monte vulture supersynthem and monticchio supersynthem). the oldest and highest deposits (terraces: ia, iia, ib) are correlated with the monte vulture supersynthem (middle pleistocene), while the younger ones (terraces: iib, iii and ic, iic, iiic) are coeval with the monticchio supersynthem (middle – upper pleistocene). more recent volcanic deposits, found near casa rossa outcrop (conza della campania synthem) are referred to a more recent volcanic activity of monte vulture (132±12 ka b.p.). the youngest volcanic products (outcrop of ripe del cavallo), dated 40.7±8.4 ka b.p., are interpreted as belonging to campanian ignimbrite of the campi flegrei area, according to chemical composition. the stratigraphic scheme, proposed in this paper, gives a new contribution to understanding the morphodynamic evolution of the ofanto river valley and the relationship between the drainage system and the monte vulture volcanic activity. parole chiave: quaternario, correlazioni stratigrafiche, terrazzi alluvionali, depositi vulcanici, fiume ofanto, appennino meridionale. keywords: quaternary, stratigraphic correlations, alluvial terraces, volcanic deposits, ofanto river, southern apennines. il quaternario italian journal of quaternary sciences 17(2/2), 2004, 511-521 1. introduzione in questa nota si presentano dati, inerenti ai depositi terrazzati dell’alta valle del fiume ofanto, derivanti dalle ricerche geologiche condotte nell’ambito del progetto di ricerca carg cnr, per il rilevamento geologico del foglio 451 “melfi” (carta geologica d’italia scala 1:50.000). il foglio (fig. 1) si posiziona lungo il confine campano-lucano dell’appennino meridionale, nella porzione sud-occidentale della valle del fiume ofanto. sul suo bordo nord-orientale affiorano parte dei prodotti vulcanici del monte vulture (de lorenzo, 1900). il fiume ofanto (fig. 1) nasce in appennino campano, a nord dell’abitato di lioni, attraversa la successione argillosa dell’avanfossa bradanica, passando a nord-ovest della piattaforma carbonatica murgiana, e sfocia nel mare adriatico a nord-ovest di barletta. il percorso del fiume, nella media ed alta valle, descrive una forma ad esse con direzione prima est-ovest, poi nord-sud ed infine di nuovo est-ovest; la bassa valle, invece defluisce da sud-ovest verso nord-est con un andamento rettilineo. queste geometrie di percorso sono legate a condizionamenti di tipo tettonico. il tratto appenninico, del fiume (carta geologica d’italia, foglio 451 “melfi”, 2004) si sovrappone ad una struttura tettonica ad attività plio-pleistocenica che segmenta le coltri appenniniche. il tratto terminale, invece, ricalca una discontinuità di primo ordine definita “linea del vulture” (schiattarella et al., 2004) che determina la segmentazione della placca “apula” in subduzione e probabilmente ha favorito la risalita dei magmi che hanno ali512 p. giannandrea mentato il vulcano monte vulture. lungo il fiume ofanto e i suoi due maggiori affluenti (fiumare di atella e di venosa) defluiscono le acque derivanti dal monte vulture con abbondante trasporto solido costituito da detrito vulcanico. i terreni quaternari affioranti nell’alta valle del fiume ofanto e della fiumara di atella e compresi nel foglio melfi (fig. 2), sono rappresentati: da depositi terrazzati rilevati sul versante destro del fiume ofanto, da depositi gravitativi (zanzucchi, 1959) presenti a sud del fiume ofanto e della fiumara di atella e da depositi vulcanici ed epiclastici del monte vulture. il substrato prequaternario è costituito in prevalenza dai depositi argillosi del bacino plio-pleistocenico dell’ofanto; dai depositi miocenici, prevalentemente arenacei delle unità irpine (cocco et al., 1972), e dalle successioni di natura argilloso-calcareo-arenacea delle unità del bacino lagonegrese (scandone, 1975). la cartografia geologica dei terreni quaternari e la relativa suddivisione stratigrafica hanno consentito di ricostruire le relazioni stratigrafiche esistenti tra: i) le unità di modellamento riconosciute a diverse quote rispetto agli alvei attuali, ii) i prodotti dell’attività vulcanica del monte vulture, iii) gli estesi fenomeni gravitativi verificati nel settore meridionale del foglio. in questa nota si riportano i risultati delle ricerche condotte lungo la valle del fiume ofanto, che attraversa l'area del foglio per circa venti km in direzione est-ovest, a nord dell’edificio vulcanico. il criterio stratigrafico adottato è quello delle unità stratigrafiche a limiti inconformi (ubsu, salvador, 1987, 1994). 2. stratigrafia dei depositi terrazzati i depositi terrazzati lungo la valle del fiume ofanto (fig. 2), sono stati rilevati tra gli abitati di calitri e s. andrea di conza e a valle della confluenza del fiume ofanto con il torrente osento. un affioramento isolato è presente in località ripe del cavallo. lungo la fiumara di atella sono stati osservati terrazzi solo in corrispondenza dell’abitato di atella. 2.1. bacino del fiume ofanto le correlazioni stratigrafiche sono state eseguite utilizzando un profilo morfostratigrafico rettificato, tracciato longitudinalmente alla valle del fiume ofanto (fig. 3). le superfici di modellamento, osservabili nell’estremità occidentale del profilo longitudinale, tra gli abitati di calitri e sant’andrea di conza (fig. 2), individuano tre ordini di terrazzi alluvionali (fig. 3; fig. 4). l’unità del primo ordine (ib) comprende due terrazzi (terrazzi dei piani di mesole e dell’incoronata di fig. 2) posizionati entrambi a quota 530 m s.l.m. e rispettivamente a 171 m e 136 m di altezza dall’attuale fondovalle del fiume ofanto. la superficie di modellamento è suborizzontale, nel caso del terrazzo di località piano di mesole, e inclinata di circa 10° in direzione ovest nel caso del terrazzo di piano dell’incoronata. solo a luoghi sono presenti piccoli lembi di conglomerato alluvionale rossastro. le tracce di modellamento dei terrazzi del secondo (iib) e del terzo (iii) ordine, ottenute attraverso l’interfig. 1 bacino idrografico del fiume ofanto catchment basin of the ofanto river. polazione dei tratti di terrazzo conservati, risultano inclinate nella stessa direzione dell’attuale fondo valle del fiume ofanto. dei due profili, quello di terzo ordine (il più recente), raggruppa lembi di terrazzi correlabili fino all’estremità ne della carta. esso è sospeso sul fondovalle attuale ad una altezza di 46 m, in prossimità di conza della campania, 61 m in corrispondenza della zona industriale di calitri e 25 m nell’estremità ne del profilo, descrivendo (fig. 3) una superficie convessa verso l’alto. i terrazzi di terzo ordine sono costituiti da 513i depositi terrazzati ... depositi alluvionali di natura sia conglomeratica che sabbiosa. i conglomerati di colore rosso sono generalmente clasto e fango-sostenuti, con a luoghi, nella parte alta, argille e silt sottilmente laminati. nei terrazzi presenti nell’estremità ne del profilo (fig. 2; fig. 3) si osservano depositi conglomeratici alluvionali in cui tra i ciottoli, di natura prevalentemente sedimentaria e subordinatamente vulcanici, sono visibili anche rari clasti di rocce vulcaniche con vistosi cristalli di flogopite, olivina, pirosseno e lapilli tuffisitici, con al nucleo cristalfig. 2 carta geologica dei depositi terrazzati della valle del fiume ofanto. geological map of the terraced deposits in the ofanto valley. 514 li di pirosseno ed olivina. a questi terrazzi sono anche associati depositi di travertino e colluviali. nel settore occidentale del profilo (fig. 3) ai terrazzi di secondo ordine (iib), visibili solo in questo settore, sono anche da ricondurre le estese coperture detritiche affioranti (fig. 2) sulle argille plioceniche (zanzucchi, 1959), nel territorio compreso fra il fiume ofanto, la fiumara di atella e gli abitati di s. andrea di conza, pescopagano e san fele. si tratta di terreni costituiti da argille ed argille marnose di colore rosso, grigio e verde in assetto caotico, con blocchi calcarenitici sparsi di dimensioni massime di 1÷2 m. queste coperture detritiche poggiano, in più punti, sui depositi alluvionali terrazzati del fiume ofanto, sospesi rispetto al fondo valle attuale di circa 100 m e costituiti da conglomerati clastosostenuti con associate lenti di sabbia di colore rosso bruno. nell’estremità ne del profilo morfostratigrafico (fig. 3), sono distinguibili altri due ordini di terrazzi (iia e ia) i cui depositi sono caratterizzati dalla presenza di terreni vulcanici del vulture, sia in facies primaria che epiclastica. tra i terrazzi di primo ordine (ia) (fig. 3) sono compresi quell i morfologicamente più elevati, sospesi sul fondovalle attuale ad una altezza variabile, da monte verso valle, da 75 m a 65 m. tali terrazzi presentano, tra i depositi conglomeratici alluvionali, (fig. 5) un banco massivo, spesso circa 1,50 m, di cenere e pomici centimetriche di colore chiaro. il terrazzo di secondo ordine (iia) (fig. 3) è costituito da un deposito spesso circa 9 m, delimitato alla base da una superficie erosiva che si approfondisce fino a 35 m dal fondovalle attuale del fiume ofanto. comprende dalla base un deposito conglomeratico alluvionale spesso circa 2 m, a cui si sovrappongono circa 7 m di cenere bruna massiva (lahars). superiormente l’unità è delimitata da una superficie di modellamento che si estende anche alle sottostanti arenarie del flysch miocenico. inoltre, lungo la valle del fiume ofanto, nelle località di casa rossa e di ripe del cavallo, affiorano terreni non riconducibili ai depositi alluvionali terrazzati. in località casa rossa (fig. 3) affiorano circa 10 m di depositi vulcanici costituiti da banchi metrici di brecce massive, con superfici irregolari ed a luoghi depositi epiclastici costituiti da sabbie conglomeratiche p. giannandrea fi g. 3 p ro fil o m or fo st ra tig ra fic o lo ng itu d in al e d el la v al le d el f iu m e o fa nt o (d a n ot e ill us tr at iv e d el f og lio 4 51 “ m el fi” , m od ifi ca to ). lo ng itu d in al m or p ho st ra tig ra p hi c p ro fil e of o fa nt o v al le y. (f ro m e xp la na to ry n ot es o f t he f og lio 4 51 ”m el fi” , m od ifi ed ). 515 con stratificazione incrociata concava. nella parte centrale della successione si osservano 70 cm di ceneri brune laminate. tra i clasti della breccia sono abbondanti quelli vulcanici, tra i quali si distinguono blocchi di natura subintrusiva con vistosi cristalli di flogopite, olivina e pirosseno. sono presenti, in tutta la successione stratigrafica, lapilli tuffisitici con al nucleo cristalli o aggregati di cristalli di pirosseno ed olivina e rari noduli di lherzoliti. nella zona periferica dell’affioramento sono osservabili strati di cenere con lamine ondulate (surge). in località ripe del cavallo (fig. 2; fig. 3) si osservano, al di sopra di un esteso fronte di cava realizzato nei conglomerati pliocenici (fig. 6), depositi conglomeratico-sabbiosi con intercalati due livelli di cenere vulcanica. i conglomerati sono sia massivi (debris-flow) che con ciottoli allineati (depositi colluviali), mentre le sabbie hanno una forte componente argillosa e presentano sottili lenti di conglomerato canalizzato. il deposito vulcanico di base (fig. 6a) ha uno spessore complessivo di 74 cm ed è massivo nei primi 20 cm e con stratificazione incrociata concava nella restante parte; la porzione superiore è costituita da due strati, di cui quello inferiore chiaro e quello superiore rossastro. le ceneri sono fini e costituite da vetro vescicolato con rari cristalli submillimetrici di pirosseno e lamelle di biotite. datazioni (buettner et al., 2003) 40ar/39ar eseguite su un campione prelevato nella parte massiva del deposito hanno fornito un’età di 40.7±8.4 ka riconducibili, anche dal punto di vista chimico, all’eruzione flegrea dell’ignimbrite campana. il deposito vulcanico superiore ha uno spessore di 40 cm ed è costituito da cenere fine massiva di colore rossastro. 2.2. bacino della fiumara di atella in corrispondenza dell’abitato di atella (fig. 2) sono presenti depositi vulcanici e lacustri correlabili con le vulcaniti di monte vulture (la volpe & rapisardi, 1977), al di sopra delle quali, separati da uno spesso paleosuolo rossastro, si distinguono tre ordini di terrazzi alluvionali (fig. 2) (ic, iic e iiic). i terrazzi del primo ordine (ic) sono costituiti alla base da travertini, con spessore variabile da 2 m a 5 m, a cui si sovrappongono conglomerati alluvionali. i travertini presentano internamente (la volpe & rapisardi, 1977) superfici piane irregolari, impronte di resti vegetali, cianoficee, rari gasteropodi polmonati, microalghe e diatomee. i terrazzi del secondo (iic) e primo (ic) ordine sono entrambi costituiti da conglomerati alluvionali con, in località la cupa, associati travertini. 3. correlazioni stratigrafiche fra i depositi terrazzati e la successione di prodotti vulcanici di monte vulture il monte vulture è l’unico vulcano quaternario posizionato sul fronte esterno dell’appennino ed è i depositi terrazzati ... fig. 4 foto panoramica dell’area di piano di mesole (vedi fig. 2 per l’ubicazione): si distinguono tre superfici terrazzate. panoramic picture of the piano di mesole sector (location in fig. 2), three terraced surfaces are distinguished. fig. 5 deposito vulcanico correlabile con le ignimbriti di fara d’olivo della successione vulcanica di monte vulture. volcanic deposit correlated with ignimbrite of the fara d’olivo of the monte vulture volcanic succession. 516 costituito da prodotti emessi in un periodo di tempo che comprende quasi per intero il pleistocene medio (cortini, 1975; villa, 1986; brocchini et al., 1994; bonadonna et al., 1998). le vulcaniti sono spesso separate da superfici erosive, paleosuoli e depositi epiclastici, che sono stati utilizzati (giannandrea et al., 2002) per la ricostruzione stratigrafica dell’intero apparato vulcanico. in figura 7 si riporta lo schema stratigrafico delle vulcaniti ricostruito per il foglio 451 “melfi” e le possibili correlazioni con le successioni terrazzate riconosciute nelle valli del fiume ofanto e della fiumara di atella. in tale schema i prodotti vulcanici si suddividono nei supersintemi di monte vulture e di monticchio a loro volta suddivisi, r ispettivamente, nei sintemi di foggianello, barile e melfi, e nei sintemi della valle dei grigi – fosso del corbo e dei laghi di monticchio. ciascun sintema comprende più subsintemi. il sintema di foggianello (fig. 7) è l’unità stratigraficamente più bassa, poggia su una superficie erosiva modellata sia sulle coltri appenniniche, compresi i conglomerati plio-pleistocenici del bacino dell’ofanto, sia sulla parte alta della successione dell’avanfossa bradanica e comprende i subsintemi della spinoritola, di campanile e di fara d’olivo. il subsintema della spinoritola è costituito prevalentemente da conglomerati alluvionali e dai filoni trachitici ad haüyna di località la spinoritola (giannandrea et al. 2002). il subsintema di campanile comprende depositi esclusivamente vulcanici, sia di caduta che derivanti da flussi piroclastici. al subsintema di fara d’olivo vengono infine riferiti ingenti depositi ignimbritici a composizione tefrifonolitica e trachifonolitica, riconosciuti da crisci et al. (1983) alla periferia del vulcano, e la formazione di una caldera (principe & giannandrea, 2002) verificatasi dopo l’effusione delle ignimbriti, e parzialmente osservabile lungo il margine nord-occidentale dell’edificio vulcanico. una lunga fase erosiva (fig. 7) assimilabile con quella denominata “flaminia” (bonadonna et al., 1998), con formazione, a luoghi, di depositi epiclastici e paleosuoli, separa il sintema di foggianello dal sovrastante sintema di barile che comprende quattro subsintemi. alla base dell’unità si riconosce il duomo fonolitico (hieke merlin et al., 1967, de fino et al., 1982, 86) del subsintema di toppo san paolo, a cui sono sovrapposti depositi piroclastici di caduta e subordinatamente di flusso (la volpe et al., 1988; la volpe & principe,1989, 1991; giannandrea et al., 2002) del subsintema di rionero. il sovrastante subsintema di vulture san michele contiene la spessa successione di prodotti affioranti in corrispondenza dell’edificio centrale di monte vulture. esso comprende lave, depositi di flusso concentrato e subordinati strati di cenere e lapilli di caduta (la volpe et al., 1988; la volpe & principe,1989, 1991). le lave sono più abbondanti in numero e in spessore in corrispondenza dell’area craterica e i depositi di flusso sono costituiti da banchi spessi fino a 10÷15 m con blocchi metrici di lava. il subsintema di ventaruolo, che chiude la serie di prodotti riferiti al sintema di barile, comprende (giannandrea et al., 2002) depositi sia di caduta che di flusso concentrato (guest j.e., et al., 1988); quest’ultimo caratterizzato dalla presenza di cristalli di leuciti centimetriche. nel sintema di melfi sono raggruppate le lave haüynofiriche (hieke merlin et al., 1967) del subsintema del castello di melfi e di piano di croce e i depositi epiclastici del subsintema di piano del gaudo. superiormente in tutta l’area del vulture si distingue uno spesso paleosuolo rossastro (m18, la volpe & principe, 1991) che fossilizza una fase tettonica (schiattarella et al., 2004) durante il quale probabilmente si è verificato il ribassamento di circa 100 m della metà meridionale dell’edificio (la volpe et al., 1984; la volpe & principe, 1994; ciccacci et al., 1999), il collasso del suo quarto sud-occidentale (principe & giannandrea, p. giannandrea fig. 6 foto panoramica di località ripe del cavallo e sezione stratigrafica; a) particolare dei depositi vulcanici osservati nella parte inferiore della sezione. panoramic view of ripe del cavallo locality and stratigraphic section of the referred deposits; a) lauer part section showing the volcanic deposits. 2002) e l’attivazione di numerose faglie orientate in direzione n30-40e. il successivo supersintema di monticchio (fig. 7) raggruppa (giannandrea et al., 2002) i prodotti vulcanici emessi da numerosi piccoli centri (identificati come subsintemi) distribuiti su faglie orientate in direzione n30-40e, quelli raggruppati nel sintema della valle dei grigi fosso del corbo, e in direzione n120 ed estovest quelli raggruppati nel sintema di monticchio. al sintema di monticchio (giannandrea et al., 2002) sono associati i prodotti emessi dai centri eruttivi di lago grande e lago piccolo in cui è stata riconosciuta (stoppa & principe, 1997; stoppa, 2003) una frazione juvenile carbonatitica e melilititica ed abbondanti noduli di origine profonda (lherzoliti a spinello) e lapilli tuffisitici. correlazioni stratigrafiche tra le successioni osservate nelle unità terrazzate del fiume ofanto sono presenti depositi vulcanici che consentono precise correlazioni con i prodotti del monte vulture. il terrazzo di primo ordine (ia) (fig. 3) descritto sul margine ne del profilo morfostratigrafico contiene, intercalato tra le facies conglomeratiche, un deposito vulcanico (fig. 5). questo è interpretabile come unità di flusso piroclastico concentrato del tipo dei pumice and ash flow, correlabile con una delle due unità ignimbritiche di fara d’olivo (crisci et al., 1983), comprese nel subsintema di fara d’olivo (giannandrea et al., 2002) (fig. 7). ciò consente di correlare, con una certa approssimazione, i conglomerati di base di tale terrazzo con quelli del subsintema della spinoritola, mentre la 517i depositi terrazzati ... fig. 7 schema stratigrafico delle unità distinte nell’edificio vulcanico del monte vulture e nei bacini idrografici del fiume ofanto e della fiumara di atella. (da note illustrative del foglio 451 “melfi”, modificato) stratigraphic scheme of volcanic units and fluvial terraced deposits of ofantoriver and atella stream (from explanatory notes of the foglio 451”melfi”, modified). superficie di tetto si correla con la discontinuità di tetto del subsintema di fara d’olivo. pertanto il terrazzo del primo ordine (ia), compreso tra due discontinuità, è correlabile anche nella successione vulcanica alla scala di sintema (sintema di foggianello). la superficie erosiva di tetto, rinvenuta fino alla quota di 35 m sul fondo valle attuale del fiume ofanto, probabilmente si forma con la fase erosiva denominata “flaminia” da bonadonna et al. (1998). in questo modo il terrazzo di secondo ordine (iia) può essere inserito nel sintema di barile, poichè comprende ceneri brune in facies epiclastica (mud flow), riferibili alle ultime fasi di attività del sintema. quest’ultima correlazione viene eseguita perchè flussi gravitativi possono essersi innescati solo dopo la formazione del rilievo di monte vulture, che avviene con la messa in posto dei prodotti del subsintema di vulture – san michele. i depositi vulcanici di casa rossa, in facies di breccia, sono indicativi di un centro eruttivo che, da un dettagliato rilievo (fig. 8), si posiziona a casa rossa. inoltre i caratteri petrografici dei componenti vulcanici del deposito e l’allineamento del centro lungo una struttura orientata in direzione n120 consente di associare questa unità con i depositi dei subsintemi di lago grande e lago piccolo. ciò induce a considerare questi depositi appartenenti a un subsintema (subsintema di casa rossa) compreso nel sintema dei laghi di monticchio, anche se attualmente non si conosce la sua età assoluta. il piccolo rilievo craterico (fig. 9), formato a seguito di questa eruzione, deve aver sbarrato nel settore sud-orientale di figura 8 il deflusso delle acque di un torrente. conseguentemente a monte delle vulcaniti si è formato un piccolo lago, colmato da depositi argillosi (fig. 9c) e da travertino. depositi di travertino si rinvengono (fig. 9b) anche lungo il margine nord-occidentale dell’affioramento, sui depositi di casa rossa fino a raggiungere la superficie di modellamento del terrazzo di terzo ordine. tra i conglomerati di quest’ultimo terrazzo si rinvengono ciottoli derivanti dall’erosione del deposito di casa rossa. tutto ciò porta a ritenere che il terrazzo di terzo ordine sia più recente del subsintema di casa rossa. il deposito più antico delle tre unità terrazzate rinvenute nell’intorno dell’abitato di atella poggia su un spesso paleosuolo rossastro correlabile con il paleosuolo m18 (rinvenuto tra i supersintemi di monte vulture e di monticchio). le tre unità terrazzate sono in rapporto tra loro, per cui è possibile ricostruire una precisa successione stratigrafica a limiti inconformi. si individuano tre subsintemi (fig. 7) raggruppati nel sintema del fosso dello stroppito, compreso a sua volta nel supersintema di monticchio. la serie di terrazzi distinti nel tratto ovest del profilo morfostratigrafico si può raggruppare in due sintemi, di questi i terrazzi inclinati nella stessa direzione del fondo valle attuale sono stati inseriti nel sintema di conza della campania, mentre quelli con inclinazione opposta sono stati inclusi nel sintema dei piani di mesole e dell’incoronata. il sintema di conza della campania comprende il terrazzo di secondo ordine (iib), definito subsintema di s. andra di conza, e quello di terzo ordine, correlabile anche nel tratto ne del profilo morfostratigrafico, definito subsintema di caperroni. i depositi del piccolo bacino di ripe del cavallo (fig. 2, fig. 3, fig. 6) hanno un’età più recente contenendo un deposito vulcanico riferibile all’ignimbrite campana (età: 40.7±8.4 ka), diffusamente affiorante in tutto il territorio dell’italia meridionale (sulpizio et al., 2003). nell’area campana le ignimbriti poggiano su una vistosa superficie erosiva e sono separate dalle sottostanti vulcaniti da un paleosuolo e da depositi colluviali ed alluvionali (bellucci et al., 2003). data l’estesa 518 p. giannandrea fig. 8 carta geologica dell’area di casa rossa (vedi fig. 2 per l’ubicazione). geological map of the casa rossa area (see fig. 2 for location). 519i depositi terrazzati ... fig. 9 profilo schematico e foto panoramica di località casa rossa (a) (vedi figura 2 per l’ubicazione); b) rapporto stratigrafico fra i depositi vulcanici ed il travertino, c) depositi lacustri al di sotto dei travertini. legenda: 1) complesso delle argille marnose, 2) arenarie mioceniche, 3) sintema di barile, 4), subsintema di casa rossa, 5) travertino del subsintema di caperroni, 6) depositi alluvionali del fiume ofanto, 7) breccia, 8) lamine ondulate, 9) faglia inversa, 10) faglia diretta. cross section and pictures panoramic view of casa rossa localtity (a) (see fig. 2 for location); b) stratigraphic relationship between volcanic an travertine deposits, c) lacustrine deposits under traverine. legend: 1) clay marl complex, 2) miocene sandstone, 3) barile synthem, 4) casa rossa subsynthem, 5) travertine of the caperroni subsynthem, 6) alluvial deposit of the ofanto river, 7) breccias, 8) cross-lamination , 9) reverse fault, 10) normal fault. superficie di dispersione delle ceneri (abbraccia tutta l’italia meridionale) e i volumi emessi (consentono di individuare con precisione il deposito anche in aree distali, come quella di ripe del cavallo), ritengo sia ragionevole utilizzare, nella stratigrafia dei depositi quaternari, come limite di supersintema la superficie di base o di tetto di questo deposito. pertanto, per una corretta attribuzione formazionale, del deposito di ripe del cavallo, è opportuno fare riferimento a uno schema stratigrafico definito nell’area della piana campana. 4. evoluzione morfostratigrafica della valle del fiume ofanto ed implicazioni tettoniche lungo la valle del fiume ofanto sono presenti elementi stratigrafici che consentono di tentare una ricostruzione delle tappe evolutive dell’area. in primo luogo la presenza, nel settore ne del profilo morfostratigrafico, dell’ignimbrite di fara d’olivo consente di datare a circa 700 ka lo stazionamento del fiume a una quota compresa fra 75 e 65 m dal fondovalle attuale. anche la presenza dei depositi lacustri nella zona dell’abitato di atella e l’assenza di prodotti vulcanici lungo la fiumara di atella, fanno ritenere che tale valle si sia formata a cominciare dalla fine del supersintema di monte vulture. inoltre la diversa inclinazione rispetto al deflusso attuale del fiume ofanto, della superficie di base del sintema dei piani di mesole e dell’incoronata può essere spiegata con l’attivazione di faglie, che avrebbero fatto basculare verso ovest l’andamento dei terrazzi (budetta et al., 1990), oppure con l’appartenenza di questi terrazzi (fig. 10) ad un corso d’acqua digradante verso ovest. và considerato infine che, in coincidenza del tetto del supersintema di monte vulture, nell’area di studio si registra un aumento di attività tettonica, come ben documentato sull’edificio vulcanico di monte vulture (schiattarella et al., 2004). tale attività probabilmente è stata responsabile del sollevamento generale dell’area, dell’attivazione di faglie inverse retrovergenti (fig. 2) e dell’innesco dell’estese coperture detritiche, distinte nell’area compresa tra il fiume ofanto, la fiumara di atella e gli abitati di pescopagano e san fele. tutti questi fenomeni devono aver fatto aumentare la capacità erosiva del fiume ofanto, che di conseguenza deve aver catturato sia le acque del paleo lago di atella che quelle del paleo lago di lioni, i cui depositi affiorano fuori dell’area studiata in corrispondenza dell’abitato di lioni (fig. 1) (hieke merlin et al., 1971; chiocchini et al., 1981). queste considerazioni consentono di raggruppare anche i terrazzi del sintema di piano di mesole e dell’incoronata nel supersintema di monte vulture, e di far rientrare il sintema di conza della campania nel supersintema di monticchio. infine la superficie convessa verso l’alto del subsintema di caperroni può essere ricondotta all’attivazione di una struttura tettonica verticale posizionata in corrispondenza della zona industriale di calitri. una possibile ricostruzione morfostratigrafica del bacino del fiume ofanto durante il pleistocene medio può essere eseguita, quindi, a livello di supersintema. infatti lungo il fiume ofanto, durante la formazione del supersintema di monte vulture, la valle doveva essere divisa in due bacini idrografici digradanti in opposte direzioni, con lo spartiacque posizionato alcuni chilometri a ovest della fiumara di atella. i terrazzi orientali rappresentano i resti dell’originaria superficie di deflusso del fiume ofanto, mentre quelli occidentali dovevano appartenere probabilmente al bacino idrografico del lago di lioni. bibliografia bellucci f., santangelo n. & santo a., (2003) – segnalazione di nuovi depositi piroclastici intercalati alle successioni continentali del pleistocene superiore-olocene della porzione nord-orientale della piana campana. il quaternario, 16 (2), 279287. bonadonna f.p., brocchini d., laurenzi m.a., principe c. & ferrara g. (1998) stratigraphical and chronological correlations between monte vulture volcanics and sedimentary deposits of the venosa basin. quaternary international, 47, 87-96. brocchini d., la volpe l., laurenzi m.a. & principe c. (1994) storia evolutiva del monte vulture. plinius, 12, 22-25. budetta p., calcaterra r., de riso r. & santo a., (1990) geologia e fenomeni franosi dell’alta valle del fiume ofanto (appennino meridionale). mem. soc. geol. it., 45, 309-324. buettner a., principe c. & villa i.m. (2003) ar-ar investigations on quaternary volcanic sequences of monte vulture (southern italy). geophysical research abstracts, 5. carta geologica d’italia (2004) foglio 451 “melfi” scala 1:50.000. servizio geologico d’italia (progetto carg, cnr), copia di prova. chiocchini u., cipriani n., & molinari p., (1981) studio geologico-tecnico per la ricostruzione di lioni (avellino) distrutto da sisma del 23 novembre 1980. boll. serv. geol. d’it., 102, 133-172. ciccacci s., del gaudio v, la volpe l. & sansò p. (1999) geomorphological features of monte vulture pleistocene volcano (basilicata, southern italy). z. geomorph. n.f., 114, 29-48. cocco e., cravero e., ortolani f., pescatore t., russo m., sgrosso i., & torre m. (1972) les faciès sedimentaires miocènes du bassin irpinien (italie meridionale). atti acc. pont., nuova serie, 21, 113. cortini m. (1975) età k-ar del monte vulture (lucania). riv. it. geof. sc. affini, 2, 45-46. crisci g., de fino m., la volpe l. & rapisardi l. (1983) pleistocene ignimbrites of monte vulture (basilicata, southern italy). n. jb. geol. paläont. mh, 12: 731-746. de fino m., la volpe l. & piccarreta g. (1982) magma evolution at mount vulture (southern italy). bull. volcanol., 45, 115-126. de fino m., la volpe l., peccerillo a., piccarreta g. & poli g. (1986) petrogenesis of monte vulture volcano (italy): inferences from mineral chemistry, major and trace element data. contrib. mineral. petrol., 17, 153-145. de lorenzo g. (1900) studio geologico del monte vulture. atti r acc sc fis mat napoli, 10, serie 2a,.207 pp. 520 p. giannandrea giannandrea p. (2003) analisi sedimentologica del sintema di monte sirico (parte alta della successione del bacino dell’ofanto. il quaternario, 16 (2), 269-277. giannandrea p., la volpe l., principe c. & schiattarella m. (2002) carta geologica del monte vulture alla scala 1:25.000. 81a riunione estiva della società geologica italiana, torino, 10-12 settembre 2002 (1a bozza di stampa). giannandrea p., schiattarella m., principe c. & la volpe l., (2004) note illustrative del foglio 451 “melfi” della carta geologica d’italia alla scala 1: 50.000, (c.n.r). 92 pp, 24 fig., 3 tab. (inviate per la stampa) guest j.e., duncan a.m. & chester d.k. (1988) monte vulture volcano (basilicata, italy): an analysis of morphology and volcaniclastic facies. bull. volcanol. 50, 244-257. hieke merlin o., la volpe l. & piccarreta g. (1967) carta geologico-petrografica del gruppo vulcanico del monte vulture (lucania). mem. ist. geol. mineral. univ. padova, 26. la volpe l. & principe c. (1989) guida alla escursione sul monte vulture del 18-19 ottobre 1989. convegno scientifico "genesi ed aspetti geodinamici del vulcanismo potassico ed ultrapotassico: stato dell'arte e prospettive di ricerca". bari, 1718 ottobre 1989, 33 pp. la volpe l. & principe c. (1991) comments on "monte vulture volcano (basilicata italy): an analysis of morphology and volcaniclastic facies" by je guest, am duncan and dk chester. bull volcanol, 53, 222-227. la volpe l. & principe c. (1994) il monte vulture. guida all'escursione generale precongressuale, 77° congr. naz. soc. geol. it., bari. la volpe l. & rapisardi l. (1977) osservazioni geologiche sul versante meridionale del m. vulture; genesi ed evoluzione del bacino lacustre di atella. boll. soc. geol. it., 96, 181-197. la volpe l., patella d., rapisardii l. & tramacere a. (1984) the evolution of the monte vulture volcano (southern italy): inferences from volcanological, geological and deep dipole electrical soundings data. journ. volcanol. geotherm. res., 22, 147162. la volpe l., principe c. & rapisardi l. (1988) monte vulture eruptive history: new stratigraphic and volcanological data . atti del 74° congresso nazionale della societa` geologica italiana, sorrento 13-17 settembre 1988, vol. a, 346-354. principe c. & giannandrea p. (2002) stratigrafia ed evoluzione geologica del vulcano vulture (basilicata, italia) rapporti fra vulcanismo ed ambienti sedimentari. 81a riunione estiva della società geologica italiana, volume riassunti, 280281, torino, 10-12 settembre 2002. salvador a. (1987) unconformity-bounded stratigraphic units. geological society american bulletin, 98, 232-237. salvador a. (ed) (1994) international stratigraphic guide. international union of geological sciences, trondheim, norway, and geological society of america, boulder, 214 pp. scandone p. (1975) the preorogenic history of the lagonegro basin (southern apennines). in: c. squyres (ed.) "geology of italy", the earth sciences society of the libyan arab republic, 305-315. schiattarella m., beneduce p., di leo p., giano s.i., giannandrea p., principe c. (2004) assetto strutturale ed evoluzione morfotettonica quaternaria del vulcano del monte vulture (appennino lucano). inviato per la stampa su: mem. soc. geol. it. stoppa f. & principe c. (1997) eruption style and petrology of a new carbonatitic suite from the mt. vulture (southern italy): the monticchio lakes formation. journ. volcanol. geotherm. res., 78, 251-265. stoppa f. (2003) consensus and open questions about italian co2-driven magma from the mantle. per. mineral, special issue, 72, 1-8. sulpizio r., zanchetta g., paterne m. & siani g., (2003) a review of tephrostratigraphy in central and southern italy during the last 65 ka. il quaternario 16 (1), 91-108. villa i. m., (1986) cronologia 39ar/40ar del complesso vulcanico del monte vulture. rend simp, 41: 146147. zanzucchi g., (1959) frane pleistoceniche nell’alta valle dell’ofanto. boll. serv. geol. it., 80: 203-208. 521i depositi terrazzati ... ms. ricevuto l’11 maggio 2004 testo definitivo ricevuto il 14 luglio 2004 ms. received: may 11, 2004 final text received: july 14, 2004 impaginato bosi ll’’iinntteerrpprreettaazziioonnee ddeellllee ssuuppeerrffiiccii rreelliittttee nneellll’’aappppeennnniinnoo cceennttrraallee:: iill ccaassoo ddeellllaa zzoonnaa ddii ccoollffiioorriittoo ((pprroovv.. ppeerruuggiiaa ee mmaacceerraattaa)) cc.. bboossii c. n. r. istituto di ricerca sulla tettonica recente via del fosso del cavaliere 00133, roma e-mail: bosi@irtr.rm.cnr.it riassunto l’utilizzazione delle successioni di superfici relitte per la ricostruzione dell’evoluzione geologica in aree di catena dispone di presupposti metodologici ancora piuttosto approssimativi, come può ritenersi indirettamente dimostrato dai risultati contrastanti recentemente ottenuti da due gruppi di ricercatori nella zona colpita dal terremoto di colfiorito (settembre-ottobre 1997) nell’alto bacino del chienti (parte centrale dello spartiacque appenninico umbro-marchigiano). questo contrasto è in larga misura connesso ai modelli genetici assunti, nonché ai criteri seguiti nella delimitazione e correlazione dei lembi di superfici relitte. un esame critico della bibliografia geologica ha portato a focalizzare l’attenzione sulle spianate sommitali (di regola interpretate come lembi di una stessa “paleosuperficie sommitale”) e sulle successioni terrazzate di superfici relitte in esse incassate. in relazione al primo argomento, partendo dalla critica alla correlazione delle spianate sommitali in quanto sommitali e dalle riserve sulle ricostruzioni che se ne possono trarre (in particolare su quella che estenderebbe a tutta la penisola la suddetta paloesuperficie), è stata prospettata la possibilità che le spianate sommitali, pur facendo parte del paesaggio relitto esistente all’inizio dell’approfondimento del reticolo idrografico conseguente al sollevamento tettonico, possano essere riferite non ad un unico evento morfogenetico, ma a più eventi verificatisi nell’ambito di tutta l’evoluzione geologica precedente. in relazione al secondo argomento, è stata prospettata l’ipotesi che i lembi, abitualmente modesti, delle superfici che costituiscono le successioni terrazzate non corrispondano alle tracce residue di larghe spianate vallive, ma a ciò che resta di spianamenti verificatisi in corrispondenza di insiemi di più modeste incisioni connesse con livelli di base relativamente uniformi. sulla base di una riconsiderazione metodologica che tiene conto delle ipotesi proposte e dei risultati già pubblicati dai due gruppi di autori sopra citati, è stato eseguito lo studio di una vasta zona comprendente l’area epicentrale del terremoto di colfiorito. questo studio ha portato alla definizione di una successione di superfici relitte, la cui distribuzione plano-altimetrica ha permesso di delineare una successione di 7 distinti ordini di spianate, incassate entro un insieme di spianate sommitali fra loro non correlabili. dalla distribuzione plano-altimetrica dei lembi osservati sono state ricavate precisazioni tettoniche che riguardano: l’inizio del sollevamento che risulterebbe riferibile ad un pliocene inoltrato, e quindi probabilmente più recente di quanto in precedenza ipotizzato; la collocazione cronologica dell’inizio dell’attività delle principali faglie che sembrano rappresentare l’espressione superficiale della struttura sismogenetica responsabile del terremoto. abstract the study of the remnant landsurfaces is of considerable interest with regard to the reconstruction of the geological evolution of the chain area. the methodology available for the use of these surfaces is still rather approximative, as is shown by the contrasting results recently obtained by two groups of researches in the area hit by the colflorito earthquake (september -october 1997, mw 5.6-6.0) in the high valley of chienti, corresponding to the central part of the divide of the chain in the umbria-marche region. this contrast mainly regards the number of landsurfaces and the area distributions of the remnants; it is in the main part connected to the genetic models assumed and to the criteria followed in the delimitation and correlation of the remnants. a critical examination of the geological bibliography regarding the planation surfaces of most of the central and southern apennines, has brought our attention to the summit surfaces and to the terraced flights of the remnant surfaces. in relation to the first argument it has been highlighted that it is not very frequent that the adjacent remnants are so near to prove directliy to belong to the same planation surface. in most cases this belonging is affirmed on the basis of correlations founded on the summit positions of the remnants and on the altitude which is often relatively even. this correlation must be evaluated with great caution in that, not only is it without adequate support, but it lends itself to hard to believe deductions. this has been recently proposed on the extension of the same summit surface to all the apennines. an alternative hypothesis can be proposed, founded on an evolutionary model, according to which the strips of the summit surfaces can be referred to not just one morphogenetic event, but to a group of further events, occurred in all the previous geological evolution. in relation to the terraces flights is formulated the hypothesis that the usually modest strips, that constitute them, do not correspond to the remaining traces of large valley bottoms but of that which remains of planation surfaces in correspondence to a group of more modest incisions attributed to the same level of deepening network. both evolution schemes proposed have noticeable implications with regards to the tectonic interpretation of remnant surfaces. the first leads us to believe that the operation of obtaining information on the extent and the amount of the tectonic uplift from surfaces altitude, must be limited to only the areas where concrete correlations can be proposed. the second, considerably reduces the importance of the present altitude of the surfaces in terraced successions. on the basis of these evolutionary schemes and of a re-examination of the criteria for delimitation and correlation of the observable strips, a study of the area epicentral to the colflorito earthquake, including the plateau of the same name was carried out. this study has led to the definition of a succession of seven distinct planation surfaces carved into a group of summit surfaces, referred to pliocene. with regards to this group, the only possible correlations are those among the remnants maintained in the m.fema m.cavallo sector. some of the most important sufaces to be mentioned are: the m.tito surface widely developed in the colfiorito plateu and in correspondence to the present chienti valley, referable to pliocene or to the initial pleistocene. the rasenna surface present only in the colfiorito and m.lago plateau, that cut sediments having an age of about 420.000 years from the distribution of the strips observed, other tectonic data has been collected that regard: the start of the uplift that would result referable to an advanced pliocene, and thus probably more recent than that which had been previously hypothesised. the chronological collocation of the start of the activity of the main faults that seem to represent the superfcial expression of the sismogenetic structure responsible for the earthquake. parole chiave: superfici relitte, tettonica, appennino centrale key-words: remnant surfaces, tectonics, central appennines il quaternario italian journal of quaternary sciences 1155(1), 2002, 69-82 11.. pprreemmeessssaa le maggiori difficoltà che si incontrano nella ricostruzione dell’evoluzione geologica quaternaria della catena appenninica derivano notoriamente dalla scarsità di successioni stratigrafiche in grado di fornire significativi orizzonti di riferimento per valutazioni tettoniche. i sedimenti plio-quaternari, prevalentemente rappresentati da depositi fluviali terrazzati entro incisioni vallive e da coltri di depositi detritici e colluviali sui versanti, sono infatti molto discontinui e di regola privi di elementi di datazione. le successioni lacustri sono di maggior utilità, ma hanno l’inconveniente di interessare solo una porzione molto piccola della catena. si rende quindi opportuno considerare anche altri elementi geologici, fra i quali hanno un ruolo importante i lembi di spianate riconducibili a superfici relitte, largamente diffusi lungo tutta la catena appenninica (bosi, 1978). in modo molto schematico si può ritenere che queste superfici possano essere utilizzate in due modi diversi. il primo consiste nell’utilizzare le successioni di superfici relitte per ricavarne indicazioni sulla mobilità tettonica delle aree nelle quali queste successioni sono rappresentate. un’approccio di questo tipo è, ad esempio, quello delineato da bosi et al. (1996) mirante a definire zone a diversa mobilità tettonica verticale di zone circostanti il fucino, e più ampiamente sviluppato da amato e cinque (1999) per la caratterizzazione cinematica quaternaria dell’appennino campano-lucano. il secondo modo consiste nel trattare le singole superfici relitte alla stregua di orizzonti di riferimento di tipo stratigrafico (quali strati, discontinuità, limiti di unità, ecc.) per il riconoscimento di specifiche deformazioni tettoniche. lo studio al quale si riferisce la presente nota riguarda prevalentemente le problematiche coinvolte in questo secondo procedimento, prendendo lo spunto dall’esame delle superfici relitte esistenti nell’area maggiormente colpita dal terremoto di colfiorito del settembre-ottobre 1997. la zona esaminata, comprendente le aree epicentrali delle tre scosse principali (cesi mw=5.7; annifo mw=6.0 e sellano mw=5.6, amato et al., 1998), corrisponde alla parte dello spartiacque appenninico delimitato all’incirca dal potenza a nord e dal nera a sud (fig.1). questa zona può essere suddivisa in due settori orograficamente diversi. il settore orientale è costituito da un gruppo di accentuati rilievi, culminanti a nord con il monte pennino (quota 1571) ed a sud con il monte fema (quota 1575), profondamente inciso dalle valli del chienti e del nera. all’estremità nord-orientale di questo settore è chiaramente individuabile un piccolo altopiano caratterizzato da estese depressioni carsiche (piano di monte lago). il settore occidentale corrisponde sostanzialmente ad un altopiano variamente dissecato, caratterizzato da modesti rilievi (quote massime 1000-1100 m) che emergono da un insieme di grandi depressioni carsiche (piano di colfiorito, piano di annifo, ecc.). questo settore risulta sospeso verso w sul bacino del topino e verso s dal bacino del nera da un insieme di ripidi versanti. nei paragrafi che seguono, la descrizione dei risultati ottenuti per quest’area è preceduta dall’inquadramento dei problemi posti dallo studio delle superfici relitte appenniniche, con particolare riguardo a quelle dell’appennino centrale. 22.. ssttuuddii pprreecceeddeennttii superfici d’erosione relitte sono state sommariamente descritte in appennino fino dai primi decenni del ‘900 (marinelli, 1922; sestini, 1939; lipparini, 1935). descrizioni più dettagliate sono quelle degli anni ‘60-‘70 riportate nei lavori di demangeot (1965) e di bertini e bosi (1976; 1978) per l’abruzzo, di desplanques (1969) per le marche, di marchetti (1974), bernini et al. (1977) e marchetti et al. (1979) per l’appennino emiliano, di bartolini (1980) per l’appennino lucchese, nonché di sestini (1981) per le colline del chianti. tutti questi lavori descrivono generalmente superfici relitte sommitali, di solito bene individuabili nel paesaggio attuale, modellate su successioni meso-cenozoiche marine variamente corrugate. lavori più recenti sono quelli citati nella sintesi che segue1. nell’appennino umbro-marchigiano, a partire dal citato lavoro di desplanques è stata ripetutamente illustrata una superficie relitta, generalmente in posizione sommitale, denominata come “la paleosuperficie” o “paleosuperficie sommitale”2, scolpita nelle formazioni calcaree, calcareo-marnose e terrigene della successione marina giurassico-miocenica. per la definizione delle sue caratteristiche si può fare riferimento a ciccacci et al. (1985) che descrivono una superfice relitta spianata o blandamente ondulata, in forte contrasto morfologico con la accentuata pendenza dei versanti delle valli che la incidono. questa superficie è stata generalmente interpretata come un paesaggio a bassa energia di rilievo, reso relitto dai fenomeni di forte incisione innestati dal sollevamento della catena; la sua genesi è stata generalmente imputata a processi erosivi a carattere areale, realizzatisi in condizioni climatiche di tipo probabilmente arido (dramis et al., 1991; dramis, 1992). calamita et al. (1999) e coltorti e pieruccini (2000) hanno avanzato l’ipotesi che la sua realizzazione sia avvenuta a quote prossime a quelle del mare, senza peraltro esplicitarne le motivazioni. la “paleosuperficie sommitale” è stata genericamente attribuita al pliocene inferiore (ciccacci et al., 1985; dramis, 1992) sulla base dei rapporti cronologici con le fasi dell’evoluzione tettonica individuate nell’area. a conferma di questa attribuzione coltorti e pieruccini (1997) hanno precisato che in corrispondenza del bacino di spoleto la superficie è correlabile con una superficie d’erosione ricoperta da sedimenti riferibili alla parte finale del pliocene inferiore. 70 c. bosi 1 per un elenco più completo di lavori sull’argomento si rimanda a messina et al. (2002) e a coltorti e pieruccini (2000). 2 nel seguito le virgolette saranno utilizzate per indicare che questo termine viene utilizzato nel senso indicato dagli autori. tutti gli autori citati sono sostanzialmente d’accordo nel ritenere che la superficie abbia avuto un’estensione regionale, avendo lasciato le sue tracce su tutto l’appennino umbro-marchigiano. recentemente coltorti e pieruccini (2000), hanno ipotizzato che la superficie fosse originariamente estesa addirittura su tutta la penisola italiana. questa ipotesi deriva, in sostanza, dalla correlazione di tutti i lembi di spianate sommitali esistenti nell’area. nella “paleosuperficie sommitale” sono debolmente incassate altre spianate d’erosione che corrispondono agli orographic terraces di ciccacci et al. (1985) ed alle “spianate non intravallive” di nesci et al. (1992); i resti di queste spianate hanno estensione abitualmente modesta (spesso di pochi ettari) ed interessano la parte superiore dei grandi versanti che incidono la paleosuperficie. più decisamente incassata in quest’ultima è una superficie relitta a carattere regionale, costituita prevalentemente da spianate pedimentarie (dramis et al., 1991; dramis, 1992) e correlabile con la “superficie villafranchiana” di demangeot (1965), riferita al pleistocene inferiore sulla base di rapporti con alcune successioni fluvio-lacustri. entro questa superficie sono poi incassate successioni terrazzate costituite sia da superfici d’erosione, 71l’interpretazione delle superfici relitte ... sia da superfici di accumulo, del tipo di quelle descritte da nesci et al. (1992) e da cantalamessa et al. (1986). situazioni analoghe a quella dell’appennino umbro-marchigiano sono note anche nell’appennino laziale-abruzzese. in questa zona sono abbastanza diffuse superfici relitte sommitali (superfici di anzano, di m.te marine e dell’aquilente)3, con caratteristiche del tutto simili a quelle della “paleosuperficie sommitale”; altre superfici (s. di longone sabino, di alto di cacchia e di pescasseroli), incassate in quelle, potrebbero corrispondere alla citata “superficie villafranchiana” (bertini & bosi, 1978; bosi, 1989b; bosi e messina, 1991; galadini e messina, 1993; cacciuni et. al., 1995) ulteriori superfici sono quelle che si osservano sui fianchi delle valli principali, progressivamente incassate le une nelle altre. molte di queste superfici hanno carattere erosionale e sono geneticamente riconducibili ad episodi di pediplanazione connessi con la temporanea stabilità di livelli di base locali; alcune altre corrispondono a superfici di accumulo al top di sedimenti fluviali o lacustri. figura 1 – schema orografico dell’area considerata. 1, 2, 3: epicentri dei principali eventi del terremoto di colfiorito del settembreottobre 1997 (1 – annifo; 2 – cesi; 3 sellano). orographic scheme of the study area; 1, 2, 3: epicentres of main events of the colfiorito earthquake of september-october, 1997 (1annifo; 2cesi; 3sellano). 3 queste superfici sono talora rappresentate da spianate dalle quali emergono modesti rilievi a versanti di regola poco inclinati. in questi casi il termine “superficie sommitale” si riferisce non alla sola spianata, ma all’insieme spianata+rilievo. situazioni di questo tipo sono note nella valle dell’aterno (bertini e bosi, 1993), nella conca del fucino (bosi et al.,1996), nella valle del salto (bosi et al., 1989; chiarini et al., 1997), nella conca di rieti (cavinato, 1993; carrara et al., 1992) ed in quella di pescasseroli (galadini e messina, 1993), nonché nella conca di amatrice (cacciuni et al. lav. cit.). una superficie relitta sommitale con caratteristiche molto simili a quella dell’appennino umbro-marchigiano è stata riconosciuta anche nell’appennino campanolucano; anch’essa era stata inizialmente interpretata come un paleopaesaggio pianeggiante, realizzatosi più o meno contemporaneamente in tutta l’area in funzione di livelli di base regionali (brancaccio e cinque, 1988). a partire dai primi anni ’90 questa interpretazione è però sensibilmente cambiata, nel senso che all’ipotesi di un’unica unità geomorfologica è stata sostituita l’ipotesi di unità plurime, elaboratesi in tempi diversi in relazione a livelli di base locali (cinque 1992; 1995). secondo questo autore l’ipotesi iniziale deve essere accantonata, non solo per alcuni difetti logici nell’impostazione delle ricerche che ne sono alla base, ma soprattutto perché è incompatibile con l’evoluzione strutturale generalmente accettata per l’appennino meridionale. anche in questa parte della catena, nella superficie sommitale sono incassate successioni terrazzate analoghe a quelle dell’appennino laziale-abruzzese. queste successioni sono state riconosciute in varie zone fra le quali sono da citare la val d’agri (amato e dimase, 1997; di niro e giano, 1995), la valle del noce (la rocca e santangelo, 1992), la valle del tanagro (ascione, cinque e tozzi, 1992), il bacino di calvello (amato e cinque, 1992) e la valle del volturno (brancaccio et al., 2000). tornando all’appennino umbro-marchigiano, un’efficace panoramica dei problemi che si incontrano nello studio delle successioni di superfici relitte può essere delineata partendo dal confronto fra due gruppi di lavori, riguardanti la zona oggetto di questa nota. il primo gruppo (ficcarelli et al., 1997; calamita et al.,1997; calamita et al., 2000) interessa una vasta area che si estende dalla valle del topino alla dorsale m.tolagna-m.cavallo, comprendendo l’altopiano di colfiorito. in questi lavori sono individuati numerosi ed estesi lembi di superfici relitte che vengono riferiti ad un’unica planation surface correlabile con la “paleosuperficie sommitale”. le principali differenze di quota fra gruppi di lembi di questa superficie sono imputate a dislocazioni tettoniche. il secondo gruppo di lavori (messina et al., 1999; messina et al., 2002)4 riguarda un’area che presenta un’ampia zona di sovrapposizione rispetto a quella considerata nel primo gruppo di lavori. il quadro delle superfici relitte che viene fornito è però sensibilmente diverso. nel settore occidentale, corrispondente all’altopiano di colfiorito, i lembi riconosciuti sono stati attribuiti a otto ordini distinti, distribuiti all’incirca fra i 750 ed i 1200 metri di quota; nel settore orientale, corrispondente a parte della dorsale m.cavallo-m.tolagna, sono distinti tre ordini di superfici situati fra 1100 e 1400 metri di quota circa. secondo gli autori, i tre ordini riconosciuti sulla dorsale sono riferibili a un paleopaesaggio analogo alla “paleosuperficie sommitale”. a questa superficie potrebbero essere riferiti anche i più alti fra gli ordini di superfici relitte riconosciute nell’altopiano; le differenze di quota con le superfici della dorsale potrebbero essere imputabili a dislocazioni tettoniche. il contrasto fra i due gruppi di lavori non è riconducibile ad una semplice divergenza di opinioni sul numero degli ordini di superfici, ma rimanda a problematiche più generali che riguardano i criteri applicati nella individuazione e nella correlazione delle superfici relitte. nel primo gruppo di lavori questi criteri non sono precisati; non sono quindi espliciti i motivi che hanno portato alla definizione di un’unica superficie relitta a dispetto del fatto, indicato da messina et al. (1999) e confermato dall’analisi svolta nell’ambito del presente lavoro, che nel paesaggio attuale possono essere agevolmente riconosciute successioni di lembi di spianate moderatamente incassate l’una nell’altra. appare quindi chiaro che con la planation surface si è inteso definire un paleopaesaggio “policiclico” comprendente questi lembi, interpretati come effetti di fenomeni di spianamento a carattere locale verificatisi nell’ambito di una fase morfogenetica sostanzialmente unitaria. nel secondo gruppo di lavori i criteri adottati sono più analitici, in quanto quelli che vengono considerati sono i singoli lembi osservati e non un insieme di lembi già interpretati come facenti parte di una stessa unità morfologica. questa impostazione discende chiaramente dall’ipotesi che: (i) i singoli lembi siano geneticamente distinti e suscettibili di correlazione in quanto connessi con la stabilità di livelli di base più generali e (ii) solo i lembi più alti possano essere interpretatati come elementi della “paleosuperficie”. le marcate diversità delle interpretazioni fornite dai due gruppi di autori devono essere ricercate nei modelli genetici che ne sono alla base e nei metodi di studio che ne derivano. 33.. mmooddeellllii ggeenneettiiccii 33..11 llaa ““ppaalleeoossuuppeerrffiicciiee ssoommmmiittaallee”” la maggior parte degli autori che si sono interessati dell’argomento ha ipotizzato che i lembi relitti attribuiti a questa superficie configurino un elemento geomorfologico sostanzialmente unitario; esso corrisponderebbe infatti ad un paleopaesaggio pianeggiante che, nell’ambito dell’area considerata da ciascun autore, si sarebbe originato in una stessa fase morfogenetica ed avrebbe presentato ovunque caratteristiche geomorfologiche analoghe a quelle dei lembi attualmente osservabili. questo paesaggio sarebbe quello esistente all’inizio dell’approfondimento del reticolo idrografico, comunemente riferito al pliocene. in appennino i casi in cui i lembi di spianate presentano una contiguità geometrica tale da comprovare direttamente l’unitarietà della “paleosuperficie sommitale” sono decisamente scarsi. nella maggior parte dei casi questa unitarietà, nell’area considerata da ciascun 72 c. bosi 4 per brevità, nel seguito la citazione dei due gruppi di lavori farà riferimento soltanto a quelli di ficcarelli et al. (1997) e messina et al. (1999) che esprimono compiutamente le valutazioni dei due gruppi di ricercatori. 73l’interpretazione delle superfici relitte ... autore, può quindi essere affermata solo sulla base di una correlazione fra le varie spianate sommitali. questa correlazione, data la mancanza pressochè totale di riscontri stratigrafici, è fondata sostanzialmente su due fatti: a) i lembi di spianate hanno una posizione sommitale; b) le quote dei lembi tendono ad essere relativamente uniformi su aree anche vaste. il valore probatorio di questi fatti deve essere considerato con molta cautela. il primo non ha alcun significato cronologico, se non quello, scontato, che ciascuno dei lembi di spianate sommitali è più antico di tutti gli eventuali lembi in esso incassati. anche il fatto che si tratta di elementi morfologici che precedono la fase di approfondimento del reticolo connessa con il forte sollevamento tettonico, non è che un vincolo “ante quem”, insufficiente per una convincente valutazione cronologica il secondo fatto (la relativa costanza delle quote) può portare a delineare una superficie unitaria solo se si postula che eventuali differenze di quota fra lembi di spianate sommitali, anzichè essere riconducibili all’incassamento di più superfici d’erosione, siano da imputare a dislocazioni tettoniche. e’ evidente che questo postulato è affetto da una marcata circolarità in quanto è fondato sulla supposta originaria unitarietà della paleosuperficie, che è proprio l’elemento in discussione. d’altra parte, nella correlazione fra le diverse spianate sommitali si deve tener conto anche del fatto, non trascurabile, che i lembi osservabili rappresentano generalmente una porzione molto piccola dell’area che si suppone essere stata interessata da quella superficie; tanto piccola che in molti settori della catena il campione rappresentato dai lembi relitti deve addirittura essere considerato come statisticamente non significativo nei riguardi della ricostruzione di qualsivoglia paesaggio originario di appartenenza5. e’ poi importante notare che correlare le spianate sommitali solo perché si tratta delle spianate più antiche (in altre parole correlare le spianate sommitali in quanto sommitali) porterebbe ad estendere la “paleosuperficie” a tutte le zone nelle quali sono presenti spianate sommitali, il che significa, di fatto, a tutto l’appennino. di conseguenza accettare questa correlazione porta, quasi inevitabilmente, ad accettare l’ipotesi di coltorti e pieruccini (2000) sulla continuità della superficie su tutta la penisola italiana. si tratta evidentemente di un’ipotesi che ha importanti conseguenze sulla ricostruzione dell’evoluzione tettonica dell’appennino, in relazione sia agli aspetti metodologici delle ricerche, sia ai vincoli che verrebbero posti alla ricostruzione stessa. essa farebbe infatti della “paleosuperficie sommitale”, da un lato, un prezioso orizzonte di riferimento che permetterebbe di valutare con continuità l’entità del sollevamento su tutta la penisola e, dall’altro, porterebbe ad ammettere un periodo di generale stabilità tettonica di durata tale da permettere una fase erosiva6 in grado di “piallare” l’intero appennino. l’ipotesi avanzata, per quanto suggestiva, appare però poco credibile. essa deve fare i conti, infatti, sia con le citate critiche di cinque (1992; 1995), sia con riserve a carattere più generale. una prima riserva (alla quale ha accennato anche questo autore) è che, a parte la “paleosuperficie sommitale”, nell’evoluzione della catena non sono noti altri indizi di quella fase di stabilità tettonica che essa presupporrebbe. questa circostanza è indirettamente provata dal fatto che l’eventuale eliminazione di questa fase di spianamento non pregiudica in alcun modo la congruenza degli attuali modelli dell’evoluzione tettonica della catena come, ad esempio, quello di calamita et al. (2000) per l’appennino centrale. altrettanto difficile è indicare nelle successioni sedimentarie dei bacini marini che nel pliocene delimitavano la dorsale appenninica (lato tirrenico e lato adriatico), attualmente affioranti ai piedi della catena, quelli che dovrebbero essere i depositi correlativi di una fase erosiva commisurata all’entità dello spianamento invocato7. e’ chiaro, inoltre, che estendere la paleosuperficie sommitale a tutto l’appennino significa aumentare enormemente i casi in cui le differenze di quota fra lembi di spianate sommitali devono essere imputati a dislocazioni tettoniche. l’argomentazione che è alla base dell’ipotesi di una superficie unitaria su tutta la penisola è quindi doppiamente circolare: nei riguardi del rapporto fra paleosuperficie e fase di stabilità tettonica che l’avrebbe generata, e nei riguardi del rapporto fra differenze di quote e dislocazioni tettoniche. un po’ come dire che la fase di stabilità tettonica è dimostrata dalla unitarietà della superficie e che la sua eventuale non-unitarietà geometrica deve essere imputata a dislocazioni tettoniche. un po’ paradossalmente, è quindi proprio la larga diffusione delle spianate sommitali che rappresenta l’elemento di maggior debolezza nei riguardi dell’ipotesi che tutti i lembi siano il risultato di una stessa fase erosiva. per ridurre il peso di questa argomentazione, in modo da poter salvare la possibilità di correlare le spianate sommitali in quanto sommitali e poste a quote simili, si potrebbe pensare di “regionalizzare” la paleosuperficie sommitale. si potrebbe, cioè, rinunciare all’idea di una superficie estesa su tutto l’appennino ripiegando su estensioni più modeste, separando ad esempio una paleosuperficie marchigiana da una laziale-abruzzese o da una umbra. le possibilità di successo di una simile operazione appaiono però piuttosto problematiche in quanto sarebbe necessario, da un lato, tracciare limiti geologicamente motivati fra le diverse aree e, dall’altro, assegnare alle paleosuperfici presenti in ciascuna di queste aree una diversa collocazione temporale ed uno specifico significato tettonico, pena la ricaduta nell’ipotesi della superficie unitaria a scala peninsulare. in un panorama interpretativo così problematico l’argomento che riveste il peso maggiore a favore dell’ipotesi di una superficie unitaria, regionale o peninsulare 5 ovviamente a meno che non si postuli la planarità del paesaggio, ricadendo così nella circolarità dell’argomentazione 6 anche se non è possibile formulare valutazioni quantitative al riguardo, l’entità della discordanza della “paleosuperficie” con le successioni sedimentarie che ne sono erose induce a ritenere quanto meno verosimile che si sia trattato di un fenomeno che ha asportato un volume considerevole di materiali, di durata certamente non breve. 7 depositi di questo tipo potrebbero essere quelli descritti da cantalamessa et al., (1986) peraltro limitati alle marche meridionali 74 c. bosi che sia, resta il fatto che questa sembra corrisponde all’unico modello evolutivo in grado di spiegare i fatti osservati. la prima obiezione che viene fatta al tentativo di negare l’unitarietà della superficie è, infatti, che non si vede in quale altro modo si possa spiegare la situazione osservata, visto che la distribuzione di lembi di spianate sommitali a quote relativamente uniformi non può essere casuale. vale quindi la pena di esplorare la possibilità di schemi genetici alternativi, che siano in grado di spiegare questa distribuzione senza ricorrere all’ipotesi della superficie unica. un tentativo in questo senso può essere effettuato partendo dalle seguenti due circostanze. a) l’evoluzione geomorfologica di gran parte dell’appennino può essere schematicamente divisa in due parti: la prima, essenzialmente pliocenica, comprende una serie di fasi erosive che hanno interagito con la strutturazione della catena; la seconda corrisponde al marcato approfondimento del reticolo conseguente al successivo forte sollevamento. b) in un’evoluzione morfologica dominata dall’erosione, le forme più conservative sono quelle planari e suborizzontali; questa valutazione è avvalorata anche dal fatto che la maggior parte delle attuali superfici relitte è di questo tipo. queste due circostanze, considerate congiuntamente, inducono a ritenere che: le forme originatesi nella prima fase evolutiva e “fossilizzate” ad opera della seconda siano rappresentate prevalentemente da spianate; queste spianate siano disposte di preferenza in posizione sommitale; questa posizione possa essere diversa da quella originaria perché la continua sovrimpressione di forme di erosione può aver obliterato altre spianate (non necessariamente sommitali) poste originariamente a quote anche più alte. la distribuzione plano-altimetrica delle spianate sommitali nel paesaggio attuale verrebbe quindi ad essere sostanzialmente determinata dalle quote attuali dei maggiori rilievi: è quindi inevitabile che là dove queste quote sono contenute in intervalli relativamente ristretti (come succede in molte zone non soltanto appenniniche) i lembi delle spianate sommitali abbiano anch’esse quote relativamente uniformi, creando l’impressione di essere riconducibili ad un’unica “paleosuperficie sommitale”. in questa prospettiva la problematica genetica di questa superficie verrebbe quindi ad avere aspetti in comune con la vecchia questione della gipfelflur (penck, 1955)8, in quanto legata anch’essa alla tendenza delle sommità dei rilievi ad assumere quote relativamente uniformi su vaste aree. uno schema che esemplifica quanto ora esposto è quella delineato nella figura 2, con una successione di quattro paesaggi incassati l’uno nell’altro, profondamente incisa dall’erosione prodotta dal sollevamento della catena. dallo schema appare chiaro che i lembi di superfici relitte più o meno pianeggianti, anche se collocati in un ristretto intervallo altimetrico, non rappresentano affatto quello che resta di un’unica paleosuperficie pianeggiante; essi sono invece il risultato di una storia erosiva che, grazie alla stabilità delle forme planari ed alla relativa similitudine di quota della sommità degli attuali rilievi, ha portato a conservare a quote simili lembi di spianate di età diversa. allo schema di fig.2 si potrebbe obiettare che i quattro paesaggi fittizi che vi sono rappresentati corrispondono a morfologie di comodo, miranti a delineare scenari favorevoli all’ipotesi proposta. in realtà non è così, visto che a risultati analoghi si arriva partendo da qualunque insieme di paesaggi incassati l’uno nell’altro, purchè siano verificate due condizioni: (i) che i paesaggi comprendano superfici pianeggianti diffuse su tutta l’area considerata e (ii) che i dislivelli fra di esse siano molto minori di quelli che separano le spianate relitte presenti entro le valli che incidono la “paleosuperficie figura 2 – schema evolutivo che dimostra la possibilità che spianate sommitali a quote analoghe non siano indicative di una “paleosuperficie sommitale” geneticamente unitaria. 1, 2, 3, 4 : successione di paesaggi pre-sollevamento; 5 paesaggio attuale; i, ii, iii, iv ordine delle spianate riferito alla successione dei paesaggi 1-4. n.b. per ciascun paesaggio non sono stati considerati gli effetti del rimodellamento relativo ai paesaggi più recenti. evolutionary scheme that demonstrates the possibility that summit surfaces at a similar altitude are not indicative of one genetically unitary surface. 1, 2, 3, 4: flights of landscapes; 5-present landscape; i,ii, iii, iv order of the planation surfaces referred to flights 1-4. n.b. for each landscape, the effects of remodelling regarding more recent landscapes have not been considered. 8 si tratta, come è noto, dell’ipotesi che la relativa uniformità delle quote dei rilievi in ampi settori di catena potessero essere dovuti all’esistenza di una fantomatica originaria superficie pianeggiante, corrispondente all’inviluppo delle cime. 75 sommitale”. ambedue queste condizioni sono del tutto compatibili con uno scenario evolutivo caratterizzato, per l’appennino, dalla forte accelerazione dell’erosione provocata dal sollevamento. le principali differenze fra l’ipotesi di una “paleosuperficie sommitale” geneticamente unitaria degli autori ed il modello evolutivo proposto risiede sostanzialmente nelle caratteristiche del paesaggio esistente all’inizio dell’approfondimento del reticolo idrografico e nel ruolo che esso riveste nella ricostruzione della componente verticale delle dislocazioni tettoniche. secondo la prima ipotesi si trattava di un paesaggio pianeggiante, diffuso a scala regionale e, almeno secondo alcuni autori (v. cap.2), originatosi a quote prossime a quelle del mare, suscettibile di fornire un ottimo orizzonte di riferimento per ricostruzioni tettoniche. secondo il modello proposto si trattava invece di un paesaggio non definibile sulla base della morfologia attuale: di esso si può solo dire che doveva comprendere lembi di spianate originatesi nel corso di tutta l’evoluzione geomorfologica precedente, alcune delle quali potevano essere anche più antiche (e più alte) di quelle attualmente conservate. tenendo conto che questa parte dell’evoluzione è interamente precedente alla parte più intensa fase del sollevamento, si può tutt’al più ritenere che il paesaggio fosse probabilmente meno accidentato di quello attuale, senza che sia però possibile alcun riferimento al corrispondente livello del mare. la possibilità di utilizzare la “paleosuperficie sommitale” nelle ricostruzioni tettoniche viene quindi ad essere notevolmente ridimensionata. lo schema evolutivo prospettato in fig. 2 non esclude ovviamente che in appennino possano esistere paleopaesaggi sommitali geneticamente unitari anche estesi; esso porta solo a negare che tutti gli attuali lembi di spianate sommitali siano necessariamente riconducibili ad un unico paesaggio pianeggiante. ipotesi di paesaggi sommitali geneticamente unitari dovrebbero, di conseguenza, essere accettate solo nei casi in cui si disponga di elementi di valutazione ragionevolmente probanti, diversi ovviamente dall’assunto “a priori” della superficie unica. 33..22 llee ssuucccceessssiioonnii tteerrrraazzzzaattee dalla sintesi degli studi riportata nel capitolo 2, emerge che situazioni rappresentate da successioni terrazzate di superfici relitte, spesso incassate in lembi di antiche spianate d’erosione, sono diffuse in tutta la catena appenninica. ciò dimostra che l’approfondimento del reticolo non si è realizzato in modo continuo, ma con alternanze di fasi di incisione e fasi di spianamento che si sono realizzate, non soltanto nell’intervallo di tempo nel quale si sono realizzate le successioni di terrazzi alluvionali generalmente presenti nella parte inferiore dei versanti, ma durante tutta l’evoluzione morfologica che ha portato al paesaggio attuale. anche senza entrare nell’esame dei fenomeni che sono alla base di questa alternanza, appare ovvio che la loro generalità alla scala dell’intera catena non può che indicare una forte influenza climatica. una situazione che rappresenta nel modo più completo l’assetto delle successioni terrazzate nelle marche, senz’altro la zona appenninica più conosciuta sotto questo profilo, è quella sintetizzata in nesci et al. (1992) riportata nella figura 3. da questa figura sembra potersi desumere che, al di là delle distinzioni terminologiche, il fenomeno del terrazzamento è sostanzialmente consistito nel progressivo incassamento di spianate la cui estensione complessiva si è progressivamente ridotta nel corso dell’approfondimento del reticolo, fino ai terrazzi alluvionali conservati nella parte inferiore dei versanti. sembra potersi desumere anche che le spianate più antiche (“spianate non intravallive” corrispondenti agli oroghraphic terraces di ciccacci et al.,1985) dovevano corrispondere a larghissime depressioni pianeggianti, incassate nella “paleosuperficie sommitale”. la verosimiglianza di questa ipotesi appare piuttosto dubbia, soprattutto per la difficoltà di spiegare in modo convincente la genesi di queste spianate. essa non può, infatti, essere imputata a fenomeni di erosione fluviale, dal momento che mancano completamente altri indizi di attività dei fiumi corrispondenti; difficile pure pensare a soli processi pedimentari di questa importanza, ripetuti durante tutto il processo di escavazione. figura 3 – sezioni morfologiche trasversali nell’area di fossombrone. t3, t2, t1 terrazzi poligenici; te terrazzi d’erosione; se spianate non intravallive (da nesci et al. 1992, semplificata). morphological sections in the fossombrone area. t3, t2, tlpoligenic terraces; teerosion terraces: senot intravallies surfaces. (by nesci et al.1992, simplified). l’interpretazione delle superfici relitte ... un altro fatto che lascia perplessi è che, nonostante l’estensione di questi ipotetici spianamenti, l’area dei singoli lembi tende ad essere sempre molto limitata. un modello evolutivo che sembra in grado di spiegare in modo più convincente la grande estensione delle aree nelle quali sono conservati lembi, anche modesti, di uno stesso ordine di spianate è quello schematizzato nella figura 4. secondo questo schema i lembi di superfici relitte sarebbero da riferire non ad un’unica spianata connessa con la stabilità del livello di base della corrispondente larghissima vallata, ma a spianate sviluppatesi sui fianchi di un insieme di valli distinte, che sono espressione di uno stesso stadio di approfondimento del reticolo. si tratterebbe quindi di effetti connessi con la stabilità di livelli di base plurimi, accumunati dal fatto di essere significativamente più bassi di quelli corrispondenti alle spianate immediatamente più antiche e più alti di quelli delle spianate immediatamente più recenti. i limiti delle zone nelle quali sono conservati lembi di spianate di uno stesso ordine corrisponderebbero quindi ai limiti delle aree sulle quali ha agito il sistema di valli appartenenti ad uno specifico stadio di approfondimento del reticolo. e’ da osservare che lo schema evolutivo proposto, se da un lato fornisce una spiegazione più convincente dei fatti osservati, dall’altro complica notevolmente l’interpretazione delle successioni terrazzate di superfici relitte. l’inviluppo dei lembi relitti appartenenti ad uno stesso ordine di superfici dovrebbe infatti essere assimilato non ad una superficie pianeggiante e suborizzontale, ma ad una morfologia più o meno irregolare la cui unica caratteristica certa è quella di presentare quote decrescenti verso i livelli di base. nel caso di successioni di più superfici incassate l’una nell’altra possono di conseguenza aumentare notevolmente le difficoltà che si incontrano sia nel definire correlazioni fra i lembi osservati, sia nel ricavare indicazioni sulle deformazioni tettoniche partendo dalla attuale distribuzione plano-altimetrica degli stessi lembi. per inciso, si può anche osservare che, adottando lo schema di fig.4, le distinzioni terminologiche proposte nel citato lavoro di nesci et al. (terrazzi vallivi poligenici, terrazzi d’erosione, spianate non intravallive), come anche quelle analoghe di altri lavori sull’argomento (v. ad esempio la carta geomorfologica allegata a dramis et al., 1992 ) potrebbero perdere gran parte delle loro motivazioni; tutte le spianate comprese fra quelle sommitali ed i sedimenti alluvionali sospesi sui fondovalle potrebbero, infatti, essere esaurientemente definite dalla loro posizione ordinale e da una precisazione in merito alla loro origine (erosionale o di accumulo). 44.. mmeettooddii ddii ssttuuddiioo in relazione ai metodi seguiti negli studi sulle superfici relitte è opportuno considerare soprattutto i criteri di delimitazione dei lembi di superfici osservati e i criteri di correlazione degli stessi. i criteri di delimitazione devono fare i conti con un’inevitabile soggettività legata a diverse circostanze, fra le quali sono da citare le seguenti: tutte le superfici relitte sono più o meno rimodellate come è dimostrato, fra l’altro, dall’assenza pressoché totale di coltri colluviali e di suoli; la distinzione fra rimodellamento ed incassamento di altre superfici può talora essere piuttosto opinabile; salvo casi eccezionali, i lembi di spianate non sono delimitati da cigli netti, cartografabili con precisione, ma da convessità più o meno pronunciate che raccordano le spianate ai versanti che le intersecano. la soggettività della delimitazione può avere conseguenze importanti sui risultati che si possono ottenere. largheggiare nella delimitazione, ad esempio, finisce inevitabilmente per aumentare in modo rilevante l’area attribuita a resti di paesaggi relitti, contribuendo ad aumentare in modo gratuito la verosimiglianza di ricostruzioni che possono invece essere molto aleatorie; porta inoltre ad ampliare l’intervallo di quota nel quale si sviluppa la superficie e, quindi, ad ipotizzare morfologie originarie più ondulate. d’altra parte, delineare lembi più ristretti (fino a considerare soltanto le quote più alte dei singoli lembi), orienta di fatto verso l’ipotesi di morfologie originarie più piatte, che possono incoraggiare ipotesi di correlazioni su basi prevalentemente altimetriche. più complessi sono i problemi relativi alla correlazione fra i diversi lembi osservati, problemi che sono diversi da quelli già analizzati a proposito delle superfici sommitali (par. 3.1) considerazioni su questo argomento possono prendere le mosse dai criteri indicati in messina et al. (1999), ripresi da bosi et al. (1996), che sono fondati sulle seguenti caratteristiche: quote dei diversi lembi; spaziatura altimetrica fra coppie di superfici apparte76 c. bosi figura 4 – schema evolutivo che riconduce i lembi relitti di successioni terrazzate all’approfondimento “per fasi” di un reticolo idrografico costituito da insiemi di incisioni di modesta entità. n.b. per le tre fasi più antiche non sono state evidenziate le fasi di incisione che hanno terrazzato le spianate di fondovalle dando origine alla successione dei diversi ordini di superfici. evolutionary scheme that leads the planation surfaces of terraces flights to a deepening of a hydrographic network made up by a group of modest incisions. n.b. for the three oldest phases, the phases of incisions that have terraced the valley bottom, giving origin to successions of different surfaces orders, have not been highlighted. nenti a successioni diverse, tenuto conto della loro pendenza originaria; posizione nell’ambito delle diverse successioni. esperienze effettuate in varie zone appenniniche sembrano indicare che questi criteri debbano essere rivisti, soprattutto per il fatto, già ricordato nel paragrafo 3.2, che la pendenza delle superfici originarie non è nota. esiste quindi il rischio, già ventilato, che si finisca con l’adottare un modello rappresentato da una serie di superfici sostanzialmente pianeggianti e suborizzontali progressivamente incassate l’una nell’altra, modello che è privo di adeguate motivazioni. un’altra considerazione che induce alla cautela nella applicazione dei criteri sopra ricordati riguarda il ruolo della posizione ordinale delle superfici nelle diverse successioni. e’ infatti ovvio che questa posizione può essere di ausilio nella correlazione fra i diversi lembi solo a patto che si possano escludere obliterazioni tali da alterare le successioni originarie, annullando le tracce di uno o più ordini di superfici. tenuto conto di queste circostanze e dei modelli evolutivi riportati nel cap.3, nello studio della zona considerata è stata seguita una procedura che può essere sintetizzata come segue. a) sono stati considerati tutti i lembi di spianate d’erosione, da suborizzontali a poco inclinate, che possono essere interpretate come tracce di antiche morfologie realizzatesi con riferimento a livelli di base diversi da quelli attuali. i limiti dei singoli lembi sono stati tracciati in corrispondenza del punto di massima curvatura della convessità che separa la spianata dal sottostante versante, eliminando l’effetto topografico dei più evidenti fenomeni di rimodellamento. b) allo scopo di definire nel modo più affidabile possibile la successione degli eventi di spianamento che hanno interessato la zona, è stato inizialmente individuato un certo numero di “successioni-base”, ciascuna delle quali è rappresentata da due o più spianate raccordate da versanti geometricamente continui, in modo da minimizzare il rischio di trascurare gli effetti di dislocazioni tettoniche. l’insieme delle “successioni-base” ha portato alla elaborazione di una “successione-tipo”, che dovrebbe corrispondere alla successione degli eventi di spianamento e, quindi, agli ordini di superfici da considerare9. c) si è proceduto poi ad una correlazione dei singoli lembi cartografati con la successione-tipo, fondata sui rapporti plano-altimetrici riferiti a scenari paleomorfologici ritenuti ragionevoli. in concreto si potrebbe dire che il quadro delle correlazioni effettuate ha corrisposto ad un processo di best fitting fondato sui vincoli derivanti dalla successione-tipo, dalla distribuzione plano-altimetrica dei lembi osservati e dalle dislocazioni tettoniche cronologicamente caratterizzate. i lembi di attribuzione problematica sono stati opportunamente evidenziati; quelli per i quali il livello di incertezza era troppo elevato sono stati definiti come “non correlabili”. e’ chiaro che la procedura delineata conserva ancora notevoli margini di opinabilità, in relazione sia alla ricostruzione della successione tipo, sia alla attribuzione dei singoli lembi di spianate agli ordini di questa successione. il metodo sembra comunque rappresentare un certo progresso non foss’altro perchè, chiarendo le motivazione delle diverse scelte, facilita la valutazione sull’attendibilità e sulla verosimiglianza della ricostruzione effettuata. 55.. llaa ssuucccceessssiioonnee ddeellllee ssuuppeerrffiiccii rreelliitt-ttee nneellll’’aarreeaa ssttuuddiiaattaa nella zona esaminata, i lembi di superfici relitte (v. carta allegata) sono relativamente numerosi ma di dimensioni generalmente modeste (raramente raggiungono 0.5-1.0 kmq), tanto che si può stimare che la superficie complessiva dei lembi osservati rappresenti mediamente alcuni percento dell’area totale. i lembi sono però distribuiti in modo tale da rendere possibile l’individuazione di un discreto numero di “successionibase” (par.4); fra le più rilevanti ai fini dello studio si possono citare quelle delle zone di m.tito e di m.camorlo, rispettivamente nel settore meridionale e settentrionale dell’area. l’insieme delle successioni-base è stato integrato in una “successione-tipo” costituita da otto ordini di superfici. per queste superfici l’abituale indicazione per ordine numerico (i, ii, iii …. ordine) è stata sostituita da una denominazione analoga a quella usata nella litostratigrafia; ogni superficie è stata cioè contraddistinta con un nome di località, tendenzialmente quella nella quale la essa è più evidente. per le superfici più antiche, riconosciute solo alla sommità dei maggiori rilievi del settore orientale dell’area considerata, è stato utilizzato il termine “gruppo delle spianate sommitali” per esprimere la valutazione che queste superfici, pur appartenendo al paleopaesaggio sul quale si è esplicata l’erosione conseguente al sollevamento, possono non appartenere ad una stessa fase morfogenetica (v. par. 3.1). altre informazioni utili alla interpretazione della carta allegata sono quelle sotto riportate. 1) nell’ambito del “gruppo delle spianate sommitali” l’appartenenza ad un’unica superficie originaria può essere ipotizzata solo per gli estesi lembi conservati alla sommità dei rilievi compresi fra m.fema, e m.cavallo, nel settore sud-orientale dell’area considerata, date le modeste distanze che li separano e l’assenza di importanti incisioni interposte. nessuna correlazione può invece essere ipotizzata fra questi lembi e quelli conservati nelle altre zone. 2) la superficie di m.tito è ben rappresentata alla sommità dei blandi rilievi che caratterizzano il settore occidentale dell’area considerata, ad ovest della dorsali di m.tolagna e di m.prefoglio-m.scalette; essa sembra però aver interessato anche un’ampia zona in corrispondenza della valle del chienti e l’altopiano di m.lago. il suo incassamento nella superficie di m.peletta ed in quelle sommitali si può osservare piuttosto chiaramente nel settore meridionale dell’area considerata. questa superficie è la più recente fra quelle che precedono l’impostazione della depressione tettonica nella quale è contenuta la successio77 9 si può osservare che, come indicato in altri lavori (carraro e ferrarino, 1981), questa successione può essere considerata l’equivalente in campo morfologico delle usuali successioni stratigrafiche (“successione morfosequenziale” in bosi, 1989a). l’interpretazione delle superfici relitte ... ne di cesi-colle curti (ficcarelli et al., 1997). dato che, secondo questi autori, la base di questa successione è riferibile al pleistocene inferiore (più antico di un milione di anni circa) il completamento della superficie di m.tito dovrebbe essere riferito pliocene o, tutt’al più, alla parte basale del pleistocene inferiore. 3) la superficie di rasenna è sviluppata a tetto della parte superiore della successione pleistocenica di cesi-collecurti, studiata da ficcarelli et al. (lav. cit.) e precisata da messina et al. (1999), contenente tephra datati a circa 430.000 anni. 4) la superficie di cavallara, definita sulle alture ad w della palude di colfiorito, è rappresentata nella parte meridionale dell’area considerata ad un sistema di fondovalle sospesi rispetto alle valli attuali. 5) la superficie di borgo corrisponde alla superficie sommitale di un terrazzo fluviale che, a sse del piano di colfiorito, è incassato sia nella superficie di rasenna, sia in quella di cavallara. 6) la superficie di casale paolucci corrisponde al top di conoidi ed a lembi di terrazzi (di erosione e di accumulo)10, sospesi sui fondovalle o su sporadici lembi di terrazzi alluvionali recenti che non sono stati considerati. si deve anche precisare che, nell’interpretazione dei lembi di superfici relitte ad e di colfiorito, si è tenuto conto delle importanti faglie ubicate al piede delle dorsali m.prefoglio-m.scalette e m.tolagna, la cui attività si sarebbe protratta fino all’attuale, come dimostrato dalle dislocazioni verificatesi in occasione del recente terremoto di colfiorito (cello et al., 1997; cinti et al., 1999). secondo altri autori (basili et al., 1998; messina et al., 1999), invece, l’attività di queste faglie si sarebbe praticamente arrestata nel pleistocene medio, ragion per cui esse dovrebbero aver interessato solo le superfici più antiche di quella di rasenna. analoga considerazione si è riservata anche alle faglie che interessano la zona ad ovest della dorsale m.acuto-m.trella che mostrano indizi morfologici di dislocazioni riferibili al pleistocene medio-superiore11. i risultati sintetizzati nella carta differiscono da quelli di ficcarelli et al. (1997) in modo radicale: tutte le superfici che vi compaiono costituiscono infatti differenziazioni dell’unica superficie sommitale individuata dagli autori. i risultati ottenuti sono sensibilmente diversi anche da quelli di messina et al. (1999), oltre che per la diversa interpretazione delle spianate sommitali, per il numero minore di superfici riconosciute nell’altopiano di colfiorito (5 invece di 8) e per la posizione stratigrafica della “superficie di m.tito”, incassata nelle superfici più antiche anziché correlabile con esse. 66.. sscchheemmaa eevvoolluuttiivvoo sulla base dei dati raccolti e delle interpretazioni schematizzate nella carta allegata e precisate nel capitolo precedente, la successione delle fasi erosive che ha interessato la zona può essere divisa in due parti. nella prima, una successione di eventi di spianamento, cronologicamente non precisabili, ha dato origine al gruppo delle “spianate sommitali”; nella seconda si è prodotta una sequenza di almeno sette eventi di spianamento, testimoniati dalle superfici comprese fra quella di colle argentiera e quella di casale paolucci, seguiti da altrettante fasi di escavazione. la successione di tutti questi eventi erosionali si è manifestata in un contesto tettonico determinato, oltre che da un sollevamento generalizzato plio-quaternario (v. cap.2), dall’attività della importante struttura tettonica corrispondente al bordo occidentale del gruppo montuoso m.fema-m.pennino (faglia di m.tolagna e faglia m.prefoglio-m.scalette già citate) (calamita et al., 1997). le modalità con le quali si è realizzata l’interazione erosione-tettonica possono essere sintetizzate come segue. a) dopo la successione degli eventi di spianamento responsabili della formazione del gruppo delle “spianate sommitali”, due distinte alternanze incisionespianamento hanno dato origine alle superfici di colle argentiera e di m.peletta. la distribuzione dei corrispondenti lembi relitti non fornisce particolari informazioni sull’evoluzione del paesaggio nel corrispondente intervallo di tempo; appare comunque probabile che le fasi erosive siano state di entità piuttosto modesta. b) una successiva, e ben più importante, fase erosiva ha portato alla individuazione di due distinti gruppi di rilievi (m.fema-m.tolagna a sud e m.camorlom.pennino a nord), separati da una larga depressione, con asse all’incirca corrispondente all’attuale valle del chienti (v. fig.5). questa fase corrisponde verosimilmente all’inizio del forte sollevamento generalizzato riconosciuto in tutto l’appennino centrale. essa è stata seguita da un importante episodio di spianamento che ha dato origine alla superficie di m.tito, profondamente incassata nelle superfici precedenti e sviluppata in tutta la parte occidentale dell’area considerata, nonché nelle zone corrispondenti alla valle del chienti ed all’altopiano di m. lago. questa fase di spianamento non sembra aver risentito della attività della faglia m.prefoglio-m.scalette. c) la successiva alternanza incisione-spianamento ha dato origine alla superficie di rasenna, moderatamente incassata in quella di m. tito, che mostra una distribuzione sostanzialmente limitata alla parte occidentale dell’area ed alla zona di m. lago12. la diferenza fra questa distribuzione e quella della superficie di m.tito suggerisce una discontinuità del panorama erosivo, probabilmente connessa con l’attività della citata faglia m.prefoglio-m.scalette. d) l’evoluzione geologica successiva alla superficie di rasenna appare condizionata dallo sbarramento del 78 c. bosi 10 nella carta allegata sono indicati solo i lembi più importanti. 11 questa valutazione è ricavata da un’analisi dei rapporti fra elementi morfologici specifici e paesaggi relitti, che sarà oggetto di una imminente pubblicazione. 12 a meno che la superficie di rasenna non possa essere riconosciuta anche nei lembi cartografati come “non attribuibili” nella zona di m.barbontile, nel qual caso la situazione di m.lago dovrebbe essere allargata verso sud. 13 secondo messina et al. (lav.cit.) allo sbarramento ha collaborato anche una grande frana verificatasi in corrispondenza del margine orientale del piano di colfiorito. 79 reticolo ad opera della faglia m. prefoglio-m. scalette13, e dalla impostazione, nell’altopiano di colfiorito, di due distinti bacini separati dalla sella de la pintura (testata del percanestro, a sw del m. tolagna). vengono così a configurarsi tre distinti bacini (colfiorito, m. lago e percanestro), ciascuno caratterizzato da una propria evoluzione, legata peraltro ad un’analoga successione di alternanze incisione-spianamento. e) la parte più recente dell’evoluzione geomorfologica si collega direttamente a quella in atto, determinata dalla forte approfondimento dei bacini del chienti, del topino e del nera e dall’evoluzione endoreica degli altopiani di colfiorito e di m.lago, influenzata da vistosi fenomeni carsici. per l’altopiano di colfiorito appare inoltre evidente il ruolo svolto, anche in questa fase, dalla struttura corrispondente alla faglia m.prefoglio-m.scalette. ai fini della ricostruzione della evoluzione geologica dell’area dovrebbero, ovviamente, essere considerate anche le indicazioni fornite dalle successioni sedimentarie esistenti nell’area. rinviando ad un successivo lavoro lo sviluppo di questo argomento, ci si limita in questa sede a ricordare che le successioni di interesse più generale sono quelle contenute nelle principali depressioni, descritte da ficcarelli et al. (1997) e da messina et al. (1999), cronologicamente collocabili fra gli eventi indicati ai punti b) e c). altre successioni di un qualche rilievo sono quelle immediatamente sottostanti alle superfici di borgo e di c.paolucci. lo schema dell’evoluzione geologica così delineato sembra suggerire che l’inizio del sollevamento generalizzato dell’area sia da porre in un pliocene piuttosto inoltrato, piuttosto che nella parte superiore del pliocene inferiore come ritenuto da coltorti e pieruccini (2000). questa valutazione deriva sia dalla non-significatività della situazione della zona di spoleto, descritta da coltorti e pieruccini, 1997), sia sul verosimile assunto di una durata non breve degli eventi che, oltre alla strutturazione della catena, hanno dato origine all’evoluzione geologica testimoniata dalla successione “superfici sommitali”s. di colle argentiera s.di m.paletta. lo schema porterebbe anche a ritenere che l’inizio dell’attività delle faglie che delimitano verso ovest le dorsali di m.tolagna e di m.prefoglio-m.scalette (o quanto meno l’inizio della fase più importante delle dislocazioni lungo di esse) sia riferibile all’intervallo compreso fra il completamento della superficie di m.tito e la sedimentazione degli strati basali della successione di cesi colle curti. 77.. ccoonncclluussiioonnii l’esame critico della bibliografia geologica relativa alle superfici relitte di buona parte dell’appennino centromeridionale ha portato ad approfondire alcuni aspetti dei modelli genetici che sono alla base delle interpretazioni finora pubblicate. un primo aspetto riguarda l’unitarietà della “paleosuperficie sommitale”. partendo dalla critica al procedimento che porta a correlare le spianate sommitali solo sulla base del fatto che si tratta delle superfici relitte più antiche nell’ambito delle varie successioni terrazzate osservate e dalle numerose figura 5 – quadro schematico della diffusione areale di alcune superfici relitte. legenda: a piano di colfiorito; b piano di monte lago; 1 superficie di m.fema (“gruppo spianate sommitali”); 2 superficie di m.tito; 3 superficie di rasenna; 4 faglie ad attività meso-supra pleistocenica. schematic outline of the distribution of some remnant surfaces. key: a piano di colfiorito; b piano di monte lago; 1 m. fema surfaces (“summit surfaces group”) ; 2 m. tito surface; 3 rasenna surface; 4 – meso-supra pleistocene faults. l’interpretazione delle superfici relitte ... riserve che si possono sollevare nei riguardi delle ricostruzioni che logicamente ne conseguono (come quella che ipotizza l’estensione della paleosuperficie sommitale su tutto l’appennino), è stata prospettata la possibilità che le spianate sommitali possano essere riferibili non ad un unico evento morfogenetico, ma ad un insieme di più eventi verificatisi nell’ambito di tutta l’evoluzione geologica precedente al sollevamento. un secondo aspetto della problematica relativa alle superfici relitte riguarda l’evoluzione dei fenomeni erosivi che sono all’origine della distribuzione spaziale delle più alte delle superfici incassate in quelle sommitali. la difficoltà di ipotizzare valli di larghezza sufficiente a comprendere tutti i lembi appartenenti ad uno stesso ordine (larghezza dell’ordine anche di parecchi km), possono essere rimosse ammettendo che l’alternanza di fasi di approfondimento e di spianamento, che ha caratterizzato tutto l’approfondimento del reticolo, abbia interessato non singole larghe vallate, ma insiemi di valli minori, accumunate dal fatto di essere condizionate da livelli di base relativamente uniformi. ambedue gli schemi evolutivi proposti hanno sensibili implicazioni nei riguardi dell’interpretazione tettonica di superfici relitte. il primo induce a ritenere che l’operazione di ricavare indicazioni sull’entità dei sollevamenti differenziali dalle differenze di quota delle superfici sommitali debba essere limitata alle sole zone nelle quali si possono proporre fondate correlazioni fra le stesse superfici. il secondo, oltre a complicare il problema delle correlazioni fra i lembi relitti, riduce considerevolmente l’importanza che le quote attuali delle superfici relitte hanno nei riguardi della ricostruzione di deformazioni tettoniche. nonostante queste limitazioni, le superfici relitte possono fornire informazioni utili ai fini della ricostruzione della evoluzione geologica di zone di catena. nel caso della zona considerata in questo lavoro, integrando la riconsiderazione dei modelli genetici con precisazioni di ordine metodologico, è stata ricostruita una successione di superfici relitte, la cui distribuzione plano-altimetrica può contribuire a precisare l’evoluzione dell’area considerata. queste precisazioni riguardano sostanzialmente: l’inizio del sollevamento e del conseguente forte approfondimento del reticolo idrografico, che risulterebbe riferibile ad un pliocene inoltrato, e quindi probabilmente più recente di quanto ipotizzato da coltorti e pieruccini (2000); l’inizio dell’attività delle faglie che bordano le dorsali di m.tolagna e m.prefoglio-m.scalette che potrebbe essere riferito all’intervallo cronologico compreso fra il completamento della superficie di m.tito e l’età degli strati basali della successione cesi-colle curti; l’origine dell’altopiano di m.lago che risulterebbe connessa con una evoluzione analoga a quella dell’altopiano di colfiorito, in accordo con le similitudini fra le caratteristiche orografiche delle due aree. rriinnggrraazziiaammeennttii l’autore ringrazia c.bartolini e f.carraro per la revisione del testo e per i suggerimenti forniti. llaavvoorrii cciittaattii amato a., azzara r., chiarabba c., cimini g.b., cocco m., di bona m., margheriti l., mazza s., mele f., selvaggi g., basili a., boschi e., courboulex f., deschamps a., gaffet s., bittarelli g., chiaraluce l., piccinini d. & ripepe m. (1998). the 1997 umbria-marche, italy, earthquake sequence: a first look at the main shocks and aftershocks. geophys. res. lett. 25 (15), 2861-2864. amato a. & cinque a. (1992). il bacino plio-pleistocenico di calvello (potenza): evoluzione geologica e geomorfologica. studi geol. camerti, vol. spec. 1992/1, 181-189 amato a. & cinque a. (1999). erosional landsurface of the campano-lucano appenines (s. italy): genesis, evolution and tectonic implications. tectonophysics, 315, 251-267 amato a. & di mase a.c. (1997). caratteristiche paleoambientali ed evoluzione geomorfologica dei plateaux della media valle dell’agri. il quaternario, 10, 213-230 ascione a., cinque a. & tozzi m. (1992). la valle del tanagro: una depressione strutturale ad evoluzione complessa. studi geol. camerti, vol. spec. 1992/1, 209-219 bartolini c. (1980). su alcune superfici sommitali dell’appennino settentrionale (prov. di lucca e pistoia). geogr. fis. din. quat. 3, 42-60 basili r., bosi v., galadini f., galli p., meghraoui m., messina p., moro m. & sposato a. (1998). the colfiorito earthquake sequence of septemberoctober 1997. surface breaks and seismotectonic implications for the central apennines (italy). journ. earth. eng. 2, 291-302. bernini m., clerici a., papani g. & sgavetti m. (1977). analisi della distribuzione planoaltimetrica delle paleosuperfici nell ’appennino emiliano occidentale. l’ateneo parmense, vol. 13, n. 4 bertini t. & bosi c. (1976). sedimenti continentali probabilmente pliocenici nella valle del salto e nella conca del fucino (rieti-l'aquila). boll. soc. geol. it. 95 (4), 767-801. bertini t. e bosi c. (1978). dati preliminari sulla neotettonica dei fogli 145 (avezzano) e 146 (sulmona). contributi preliminari alla realizzazione della carta neotettonica d’italia, p.f.geodinamica, pubbl. n.155 bertini t & bosi c. (1993). la tettonica quaternaria della conca di fossa (l’aquila). il quaternario, 6, 293314 bosi c., (1978). relazione introduttiva al tema “neotettonica”. mem. soc. geol.it., 19, 521-534 bosi c. (1989a). considerations and proposals on morpho-pedo-litostratigraphic units in quaternary studies. il quaternario, 2, 3-9 bosi c. (1989b). tentativo di correlazione fra le successioni plio-pleistoceniche. in "elementi di tettonica pliocenico-quaternaria ed indizi di sismicità olocenica nell'appennino laziale-abruzzese". guida all’escursione, soc. geol. it., esagrafica roma. bosi c., caiazzo c., cinque a. & messina, p. (1996). superfici relitte ed evoluzione plio-quaternaria dell’area fucense (appennino centrale). il quaternario 9 (1), 381-386. 80 c. bosi 81 bosi, c. & messina, p. (1991). ipotesi di correlazione fra successioni morfo-litostratigrafiche plio-pleistoceniche nell'appennino laziale-abruzzese. studi geol. cam., vol. spec. 1991/2, 257-263. bosi c., messina p. & sposato a. (1989). la depressione del salto. in elementi di tettonica pliocenicoquaternaria ed indizi di sismicità olocenica nell’appennino laziale-abruzzese. guida all’escursione, soc. geol. it., esagrafica roma brancaccio l. & cinque a. (1988). l’evoluzione geomorfologica dell’appennino capano-lucano. mem. soc.geol.it, 41, 83-86 brancaccio l., di crescenzo g., rosskopf c., santangelo n. & scarciglia f. (2000). i l quaternario, 13, 81-94 cacciuni a., centamore e., di stefano r. & dramis f. (1995). evoluzione morfotettonica della conca di amatrice. studi geol. camerti, vol. spciale 1995/2, 95-100 calamita f., coltorti m., pierantoni p.p., pizzi a., scisciani v. & turco e. (1997). relazioni tra le faglie quaternarie e la sismicità nella dorsale appenninica: l’area di colfiorito. studi geologici camerti, xiv, 177-191 calamita f., coltorti m., pieruccini p. & pizzi a. (1999). evoluzione strutturale e morfogenesi plio-quaternaria dell’appennino umbro-marchigiano tra il preappennino umbro e la costa adriatica. boll. soc. geol. it., 118, 125-139 calamita f., coltorti m., piccinini d., pierantoni p.p., pizzi a., ripepe m., scisciani v. & turco e. (2000). quaternary faults and seismicity in the umbro-marchean apennines (central italy): evidence from the 1997 colfiorito earthquake. journ. geodynamics. 29, 245-264. cantalamessa g., centamore e., chiocchini u., colalongo m.l., micarelli a., nanni t., pasini g., potetti m. & ricci lucchi f. (1986). i l pliopleistocene delle marche. in: la geologia delle marche, studi geol. camerti, vol. spec. carrara c., brunamonte f., ferreli l., lorenzoni p., margheriti l., michetti a.m., raglione m., rosati m. & serva l. (1992). i terrazzi della medio-bassa valle del fiume velino. studi geologici camerti, vol.spec. 1992/1, 97-102 carraro f. & ferrarino g. (1981). tentativo di realizzazione di un nuovo tipo di carte morfologiche: la carte morfostratigrafiche. atti xvii conv. naz. ass. it. cartografia, venezia 19-21 nov. 1981 cavinato g.p. (1993). recent tectonic evolution of the quaternary deposits of the rieti basin (central appennines, italy): southern part. geologica romana, 29, 411-434 chiarini e.,, messina p. & papasodaro f. (1997). evoluzione geologica e tettonica plio-quaternaria dell’alta valle del f.salto (italia centrale): primi risultati derivanti dall’analisi delle superfici relitte e dei depositi continentali. il quaternario, 10, 625630 ciccacci s., d’alessandro l., dramis f., fredi p. & panbianchi g. (1985). geomorphological and neotectonic evolution of the umbria-marche ridge, northern sector. studi geol. camerti, x, 7-15 cinque a. (1992). distribuzione spazio-temporale dei movimenti tettonici verticali nell’appennino campano-lucano: alcune riflessioni. studi geologici camerti, vol. spec. 1992/1 cinque a.(1995). verso una reinterpretazione delle evidenze geomorfologiche di neotettonica in un’area di tettogenesi recente: l’appennino campano-lucano. il quaternario, 5 (2) 299-304 cinti f.r., cucci l., marra f. & montone p. (1999). the 1997 umbria-marche earthquake (italy): relation between ground defromation and seismogenic structure. geoph. rese. lett., 26, 895-898 coltorti m. & pieruccini p. (1997). the southern east tiber basin (spoleto, central italy): geology and stratigraphy of the plio-pleistocene sediments. il quaternario 10 (2), 159-180. coltorti m., albianelli a., bertini a., ficcarelli g., laurenzi m., napoleone g. & torre, d. (1998). the colle curti mammal site in the colfiorito area (umbro-marchean apennine, italy): geomorphology, stratigraphy, paleomagnetism and palynology. quat. int. 47/48, 107-116. coltorti m. & pieruccini p. (2000). a late lower pliocene planation surface across the italian peninsula: a key tool in neotectonic studies. journ. geodynamics. 29, 323-328. demangeot j. (1965). geomorphologie des abruzzes adriatiques. cnrs, masson, parigi desplanques h. (1969). champagnes ombriennes. cnrs, paris di niro a. & giano s.i. (1995). evoluzione geomorfologica del bordo orientale dell’alta val d’agri. studi geol. camerti, vol. spec. 1995/2 dramis f. (1992). il ruolo dei sollevamenti tettonici a largo raggio nella genesi del rilievo appenninico. studi geologici camerti, vol. spec. 1992/1, pag.915 dramis f., pambianchi g., nesci o. & consoli m. (1991). il ruolo di elementi struturali trasversali nell’evoluzione tettonico sedimentaria e geomorfologica della regione marchigiana. studi geol. camerti, vol.spec. 1991/2, p.287-293 dramis f., gentili b. & pambianchi g. (1992). la depressione morfostrutturale di macerata. studi geol. camerti, vol. spec. 1992/1 ficcarelli g., abbazzi l., albianelli a., bertini a., coltorti m., magnatti m., mazza p., mezzabotta c., napoleone g., rook l., rustioni m. & torre d. (1997). cesi, an early middle pleistocene site in the colfiorito basin (umbro-marchean apennine, central italy). journ. quat. sci. 12 (6), 507-518. galadini f. & messina p. (1993). stratigrafia dei depositi continentali, tettonica ed evoluzione geologica quaternaria dell’alta valle del f.sangro. boll. soc. geol. it., 112 la rocca s & santangelo n. (1992). nuovi dati sulla stratigrafia e sull’evoluzione geomorfologica del b cino lacustre pleistocenico del f.noce (basilicata). geogr. fis. din. quaternaria 14, 229-242 lipparini t. (1935). i terrazzi fluviali dell’emilia, giorn. geolo., serie 2a, 9bis, 43-88 marchetti g. (1974). studi geomorfologici in rapporto alla neotetonica della fascia pedecollinare piacentina. st. trent. di sc. nat. vol.51. marchetti g., perotti c. & vercesi p.l. (1979). possible significance of the paleosurfaces with reference to the geomorphological plio-quaternari evoluzion of l’interpretazione delle superfici relitte ... the piacenza appennine. proc. 15th plenary meeting og igu commission on geomorphological survey ad mapping. catania 715 sett. 1979 marinelli o. (1922). atlante dei tipi geografici. firenze igm messina p., galadini f., galli p. & sposato a. (1999). evoluzione a lungo termine e caratteristiche della tettonica attiva nell’area umbro-marchigiana colpita dalla sequenza sismica del 1997-1998 (italia centrale). in: l.peruzza (a cura di), metodi innovativi per la stima dell’hazard: applicazione all’italia centrale. cnr – gndt? messina p., galadini f., galli p. & sposato a. (2002). quaternary basin evolution and present tectonic regime in the area of the 1997-1998 umbriamarche seismic sequence (central italy). geomorphology, 42 nesci o., savelli d. & veneri f. (1992). terrazzi vallivi e superfici di spianamento nell’evoluzione del rilievo appenninico marchigiano. studi geol.camerti, vol.spec. 1992/1 penck a. (1955). morphological analysis of landoforms. london, mc millan sestini a. (1939) osservazioni geomorfologiche sull’appennino tosco-emiliano tra il reno ed il bisenzio. att. soc. tosc. scienze nat., xlviii sestini a. (1981). un’antica superficie di erosione nei monti del chianti. riv. geogr. it., 88, 214-220 82 c. bosi ms. ricevuto il 26 marzo 2002 testo definitivo ricevuto il 28 maggio 2002 ms. received: march 26, 2002 final text received: june 28, 2002 imp. ascione llee vvaarriiaazziioonnii ggeeoommoorrffoollooggiicchhee iinnddoottttee ddaallllaa tteettttoonniiccaa rreecceennttee iinn aappppeennnniinnoo mmeerriiddiioonnaallee aalleessssaannddrraa aasscciioonnee && aallddoo cciinnqquuee dipartimento di scienze della terra, università degli studi di napoli “federico ii”, largo s. marcellino 10, 80138 napoli riassunto accanto agli effetti derivanti dallo scuotimento sismico, le deformazioni tettoniche generano nel paesaggio modificazioni i cui tipi ed entità sono funzione dal rapporto tra i tassi delle deformazioni ed i ritmi dei processi eroso/deposizionali con i quali esse interagiscono. in questo lavoro vengono esaminati i principali tipi di variazioni ambientali causati dalle deformazioni tettoniche tardo-quaternarie in appennino meridionale, una regione nella quale i lineamenti tettonici ad attività recente sono caratterizzati da una debole espressione morfologica. ciò appare rappresentare la risposta ad una tettonica che si manifesta con fagliazioni distribuite su numerosi lineamenti, ciascuno dei quali registra bassi tassi deformativi, cui si oppone una dinamica esogena che, grazie al clima, al giovane rilievo ed all’elevata erodibilità dei terreni occupanti vaste aree, risulta particolarmente vivace. abstract besides the effects resulting from the seismic shaking (landslides, sinking, etc.), active tectonics may affect the environment, on a longer time scale, through changes whose types and magnitudes depend on the relationships between the rates of deformation and the rates of geomorphic processes. type and magnitude of changes will thus vary according to the geomorphic scenario in which deformations take place. in this paper is presented an overview on the changes triggered by recent deformations (e.g. to tectonics active since the late quaternary) in environments characterised by different rates of the erosional/depositional processes. the scenarios examined are river valleys, intramontane basins, coastal plains and slope areas. in the region, the observed environmental changes appear on the whole quite subdued: this is due to the interplay between the low slip rates (on the order of few tenths of mm/yr) of the numerous and widely distributed normal faults active within the present extensional regime, and the high rates of the exogenous processes. the latter are controlled by the aggressive mediterranean climate, by the high relief of the young chain (that formed starting from the miocene) and by the widespread occurrence of highly erodible rocks. in contrast, in the volcanic district of the campania region (which comprises the phlegrean fields, the somma-vesuvius and the neapolitan islands), high rate volcano-tectonic vertical movements triggered strong and rapid environmental changes in the holocene; in the coastal campana plain, these vertical movements were roughly counterbalanced by high rates pyroclastic deposition. parole chiave: geomorfologia, tettonica attiva, variazioni ambientali, quaternario, appennino meridionale. keywords: : geomorphology, active tectonics, environmental change, quaternary, southern apennines. il quaternario italian journal of quaternary sciences 1166(1), 2003, 133-140 pprreemmeessssaa l’appennino meridionale, risultato di una strutturazione molto recente, è interessato da una tettonica ancora attiva che, tra l’altro, si manifesta con un’intensa e frequente sismicità che ha dato luogo anche a devastanti terremoti in epoca storica ed attuale. ciò nonostante, la forte articolazione orografica che caratterizza la regione non appare che localmente (e.g. fianco tirrenico) dominata da forme tettoniche: all’interno della catena, infatti, il rilievo è per buona parte scandito da alti versanti strutturali con varie orientazioni che, tuttavia, sono in maggioranza forme a controllo strutturale passivo quali versanti di linea di faglia. d’altra parte, per quei versanti strutturali che sono legati in modo diretto alla tettonica più recente (scarpate di faglia quaternarie) si hanno oramai sufficienti dati geologici e morfologici per concludere che, nel corso delle ultime centinaia di migliaia di anni, essi hanno registrato ritmi di crescita relativamente blandi (nell’ordine dei decimi di mm/a), derivati da riattivazioni di ordine decimetrico con ricorrenze di ordine millenario (ascione & cinque, 1997). evidenze di un rallentamento dei ritmi medi di deformazione della catena nel corso del tardo quaternario sono anche l’estinzione dei grandi bacini lacustri intracatena (creati e mantenuti attivi dalla tettonica del pleistocene inferiore e medio), nonché le recenti emersioni e progradazioni registrate nelle depressioni peritirreniche, che erano invece state occupate da ampi golfi marini nel precedente intervallo a maggiore ritmo di subsidenza. la scarsa espressione morfologica dei lineamenti tettonici sembra essere la conseguenza sia della recente impostazione del regime tettonico attualmente attivo, sia delle modalità con cui esso si manifesta. tale regime, che è regionalmente caratterizzato da estensione (hippolyte et al., 1994) avente direzione analoga a quella ottenuta dai meccanismi focali dei terremoti del sud italia (cello et al., 1982; gasparini et al., 1985) ed ha seguito la cessazione, avvenuta nel pleistocene medio, dei raccorciamenti sul fronte esterno (patacca & scandone, 1999) e dei ribassamenti distensivi sul fianco tirrenico, si è instaurato infatti solo nel tardo pleistocene medio (caiazzo, 2000; cinque et al., 2000). in esso, inoltre, si registra l’attivazione di numerose faglie distribuite su larga parte della catena, dal margine tirrenico fino all’ex-avanfossa: tra le faglie la cui attività recente è stata riconosciuta, ciascuna appare aver assommato piccoli rigetti, con ritmi medi relativamente bassi, nell’ordine di pochi decimi di mm/a nell’intero intervallo tardopleistocene medio attuale (cinque et al., 2000; ascione et al., 2003). 134 a. ascione & a. cinque ad una tettonica agente con bassi tassi, si oppongono processi eroso/deposizionali che sono particolarmente aggressivi sia perché il rilievo locale nella giovane catena è ancora alto, sia per il contesto climatico regionale, sia, infine, perché larga parte della regione (le aree esterne della catena, l’ex-avanfossa, ma anche vaste porzioni delle zone interne come il promontorio cilentano) è occupata da litotipi ad alta erodibilità. 11 llee mmooddiiffiiccaazziioonnii ccrreeaattee nneell ppaaeessaaggggiioo ddaallllaa tteettttoonniiccaa in uno scenario quale l’appennino meridionale, caratterizzato cioè da una tettonica che agisce con ritmi mediamente molto prossimi (se non, a luoghi, inferiori) a quelli della dinamica esogena, ci si attende che le deformazioni recenti abbiano prodotto solo lievi modificazioni del paesaggio. poiché la velocità del modellamento varia in funzione dei tipi e dei ritmi dei processi eroso/deposizionali agenti che, a loro volta, sono condizionati dall’erodibilità dei litotipi affioranti, gli effetti delle fagliazioni variano al variare (oltre che dei ritmi che le sono propri) dei contesti orografici e litologici in cui si articola una regione. nei contesti conservativi in cui i ritmi della dinamica esogena sono lenti, ad esempio, gli effetti delle crisi deformative vanno sommandosi nel tempo, dando luogo a forme più vistose rispetto a quelle che ci si attende di rinvenire nelle aree in cui i processi eroso/deposizionali si manifestano con maggiore vivacità. al contempo, dove i processi esogeni agiscono con alti tassi, le forme tettoniche riconoscibili saranno solo quelle molto recenti. 1.1 effetti delle fagliazioni in ambienti fluviali le interazioni della tettonica con i processi legati al sistema morfodinamico fluviale danno luogo a diversi tipi di modificazioni nel paesaggio (santangelo, 2003); tra esse le più vistose sono quelle dovute al movimento differenziale di blocchi in senso trasversale rispetto ai tracciati fluviali. nella regione qui presa in esame, esempi di recenti sovralluvionamenti causati da questo tipo di fenomeno si hanno nell’alta valle del volturno (brancaccio et al., 1997) e nella piana di alife, al margine nne della piana del volturno, dove sono riferibili al pleistocene finale olocene (successivi alla deposizione dell’ignimbrite campana; quest’ultima ha età 39 ka; de vivo et al., 2002), ma anche nella porzione settentrionale del bacino dell’alta val d’agri; altri casi si riscontrano nel massiccio del m. marzano, dove sono dovuti all’attività di faglie tra le quali quella che ha prodotto dislocazioni durante il terremoto del 1980 (cinque et al., 1980; westaway & jackson, 1987; pantosti & valensise, 1990: ascione et al., 2003). il tipo di risposta del sistema fluviale a movimenti verticali di blocchi è essenzialmente controllato dal rapporto tra il tasso della tettonica e quello della dissezione fluviale, quest’ultimo dipendente, oltre che dal potere erosivo del corso d’acqua, dall’erodibilià dei terreni costituenti la soglia. la creazione di ambienti con sedimentazione lacustre, infatti, è favorita nei casi in cui la soglia è impostata in litologie resistenti all’erosione: in appennino meridionale, il sollevamento relativo di soglie carbonatiche ha, ad esempio, provocato l’instaurarsi di ambienti lacustri nei bacini di acerno (nel pleistocene medio; munno et al., 2001), camerota (nel pliocene superiore), del vallo di diano (tra il pleistocene medio e l’olocene). più complessa è la risposta dove, nell’area interessata dalle disarticolazioni verticali, sono presenti terreni ad alta erodibilità. questi tipi litologici affiorano largamente nella regione, dove sono dati dalla gran parte delle successioni terrigene costituenti le coperture flyschoidi e le falde interne liguridi e sicilidi (tutti occupanti vaste aree, ad es., del promontorio cilentano e della fascia esterna della catena), ma anche le successioni argilloso-sabbioso-conglomeratiche prevalentemente plio-quaternarie che costituiscono il riempimento di bacini satellite (diffuse soprattutto nella fascia esterna della catena), nonché della vasta avanfossa bradanica, oltre ai depositi alluvionali quaternari (fig. 1). da quanto si osserva, nelle aree in cui sono stati creati depocentri a tergo di strutture in sollevamento impostate in terreni ad alta erodibilità, i tassi della dissezione hanno mediamente bilanciato quelli della tettonica. ad esempio, nei bacini della bassa valle del tanagro (pleistocene medio; amato et al., 1991), della valle del melandro (pleistocene inferiore, santangelo, 1991) e dell’alta val d’agri (di niro et al., 1992), che sono chiusi da soglie in rocce tenere, la sedimentazione è caratterizzata prevalentemente da facies fluviali, cui si intercalano limitati intervalli pelitici a testimoniare solo brevi periodi di ostruzione del drenaggio. si può poi osservare che, in questi casi, lo spessore del pacco sedimentario non rappresenta che un’approssimazione per difetto dell’entità di sollevamento relativo della soglia, che veniva interessata da contemporanea dissezione. nelle aree occupate da rocce tenere, la presenza di tratti sovralluvionati costituisce spesso la più evidente, se non l’unica, traccia della disarticolazione del tracciato longitudinale di valli fluviali. infatti, mentre nelle valli chiuse da soglie in rocce resistenti l’aggradazione a monte di un alto in sollevamento è accompagnata dalla nascita di una forra ripida attraverso la soglia, ma anche, se il sollevamento è dovuto all’attività di una faglia, dalla nascita di una ripida scarpata lungo il lineamento (vedi gli esempi citati del vallo di diano, di camerota, di acerno), questi caratteri morfologici possono mancare nel caso di soglie “tenere”. ciò è quanto si osserva, ad esempio, nella bassa valle del tanagro, dove i fianchi vallivi nel blocco sollevato, come pure la scarpata di faglia, mostrano un profilo non sensibilmente diverso rispetto a quelli dei tratti contigui (fig. 2); ciò dipende dal fatto che, con simili terreni, lo slope decline dei versanti vallivi procede tanto rapidamente che, al limite, esso può riuscire a tenere il passo della dissezione. in situazioni di questo tipo, la ricostruzione è confermata dal dato geologico che la base del riempimento alluvionale si pone ben al di sotto (fino a molte decine di metri) della quota del fondovalle nel tratto sollevato. questa conferma diventa decisiva per distinguere i casi di influenza attiva “certa” della tettonica da quelli di controllo passivo esercitato da variazioni litologiche lungo il percorso vallivo, che similmente possono generare tratti stretti senza depositi e tratti più ampi e svasati con fondivalle a copertura alluvionale, che, però, in questi casi è sottile: tali situazioni ricorrono lungo le valli che dissecano la zona esterna della catena, caratterizzata da pieghe e faglie inverse coinvolgenti complessi di erodibilità differenziata. va comunque considerato che, al limite, depocentri potrebbero non nascere anche nel caso di soglie tettoniche impostate in litologie ad erodibilità tanto alta (ad esempio, le argille) da permettere alla dissezione di tenere il passo del tasso di sollevamento. 135le variazioni geomorfologiche ... 1.2 variazioni ambientali legate ai rapporti tra tettonica e sedimentazione nelle depressioni subsidenti, che in appennino meridionale sono date da graben costieri e conche intramontane (fig. 3), l’intergioco tra la dinamica esogena e quella endogena può causare sensibili variazioni ambientali che possono tradursi, nelle aree costiere, in migrazioni della linea di costa e degli ambienti di transizione ed, nelle conche, in modificazioni nei sistemi deposizionali e nell’avvicendamento tra contesti geomorfologico/sedimentari diversi. come esempio, tra le conche intramontane, può citarsi quello del vallo di diano, una depressione tettonica con versanti più attivi lungo il suo margine orientale, in cui si è registrato nel corso del pleistocene medio un sostenuto ritmo dei ribassamenti (intorno a 0.7 mm/a; karner et al., 1999). lo spazio creato dalla notevole mobilità della faglia bordiera è stato accomodato, oltre che dall’aggradazione lacustre, da quella di numerosi apparati di conoide provenienti dallo stesso versante, i cui depositi erano tuttavia confinati presso quello stesso margine. a partire dal tardo pleistocene medio, il ritmo medio dei ribassamenti è andato attenuandosi (esso è valutabile in circa 0.2 mm/a nel pleistocene superiore olocene) fino a divenire inferiore a quello della sedimentazione. ciò ha comportato la vistosa progradazione di ampi sistemi di conoide alimentati dai rilievi orientali sulle facies lacustri che sono state confinate, riducendosi in ampiezza, verso l’opposto margine della depressione (fig. 4) ed, infine, il progressivo colmamento del bacino che, in epoca storica, veniva occupato da un’ampia palude fino alla definitiva bonifica. in questa stessa conca, una possibile recente ripresa della tettonica è suggerita dall’impaludamento che rese necessario, in epoca borbonica, riprendere la bonifica già realizzata in epoca romana allorquando, tra l’altro, si provvide ad approfondire la forra che attraversa la soglia calcarea che richiude la conca verso nord. in altri casi osservati, la recente progradazione fig. 1 schema strutturale dell’appennino meridionale. modificato da modello strutturale d’italia (scandone et al., 1983). structural sketch map of the southern apennines. modified after structural model of italy (scandone et al., 1983). fig. 2 una faglia con componente verticale del rigetto crea un ostacolo attraverso un tracciato fluviale in un’area occupata da rocce altamente erodibili. questo fenomeno può essere denunciato solo dalla presenza, a monte dell’ostacolo, di un tratto sovralluvionato in cui la base dell’accumulo si spinge al di sotto di quella del fondovalle nella forra: il rapido addolcimento dei neogenerati fianchi della forra e scarpata di faglia, infatti, fa si che questi non appaiono più “freschi” rispetto ai più antichi versanti del tratto a monte. a: block diagram illustrating a normal component fault cutting across a valley which dissects highly erodible rocks; b: plan view of the same area. in such cases, the antecedence may be revealed only by the presence of a thick mantle of alluvial deposits whose base is found at an elevation lower than the elevation of the bottom of the neighbouring, downvalley gorge. other expected morphological parameters, such as steep newly generated gorge flanks and a steep fault scarp, are not found due to the slope decline that may proceed fast enough to keep peace with both the river downcutting and the fault slip. 136 degli apparati di conoide disposti lungo fronti montuosi bordati da faglia, come quelli della piana di alife, o alcuni tra quelli del bacino del pantano di s. gregorio magno, costituisce un effetto dello slittamento dell’area di massima deposizione degli stessi conoidi verso la zona centrale del bacino, indotto dal fatto che la faglia si muove con un tasso inferiore a quello della sedimentazione del conoide. in questi casi, fagliazioni recenti hanno interessato gli stessi apparati di conoide, provocando il sollevamento relativo, con conseguente dissezione, della loro porzione apicale e la formazione di nuovi conoidi incastrati nei precedenti ed aventi un’area depocentrale più avanzata rispetto ai primi (fig. 5). nei graben costieri presenti lungo il margine tirrenico della campania, che erano stati sede di considerevoli ribassamenti nel corso del pleistocene (fino ad oltre 3000 m nella piana campana, circa 2000 m nella piana del sele e circa 800 m in quella del garigliano; ippolito et al., 1973; brancaccio et al., 1991), i mutamenti nel rapporto tra il ritmo della sedimentazione e della tettonica occorsi dal tardo-pleistocene – olocene hanno provocato considerevoli variazioni ambientali. in particolare, la cessazione dei ribassamenti ed il sollevamento post-tirreniano di una vasta porzione della piana del sele hanno favorito la progradazione della fascia costiera a partire dalla fine della risalita post-glaciale. nella piana del volturno, che era stata ingredita fino ai rilievi carbonatici bordieri nell’ultimo interglaciale (romano et al., 1994), la sostanziale cessazione della subsidenza e la cospicua aggradazione sedimentaria e vulcanoclastica hanno permesso, nel corso dell’ultimo glaciale e dell’olocene, una progradazione della piana di circa 20 km (barra et al., 1996). nella porzione meridionale della piana campana, la piana del sarno, la presenza di precisi marker, quali livelli torbosi datati, depositi dell’eruzione vesuviana del 79 d.c. e le tracce di linea di riva romana, ha consentito di ricostruire importanti variazioni ambientali occorse nella seconda parte dell’olocene. in tale periodo, nonostante la notevole fig. 3 le depressioni peritirreniche e le principali conche intramontane dell’appennino meridionale. con il rigato verticale, le aree che sono state in aggradazione fino al pleistocene medio p.p.; con il rigato orizzontale, le aree ancora in aggradazione nell’olocene. the peri-tyrrhenian grabens and the main intramontane tectonic depressions of the southern apennines. the vertical lines indicate the areas which have been subject to aggradation until the middle pleistocene p.p.; the horizontal lines mark the areas affected by aggradation in the holocene. fig. 4 evoluzione del vallo di diano durante la parte bassa del pleistocene medio (aa) e nel tardo pleistocene medio olocene (bb). aa: gli alti tassi di scorrimento del lineamento bordiero orientale vengono in parte compensati da aggradazione lacustre e dei conoidi; la sedimentazione di questi ultimi è confinata al margine attivo dove viene continuamente creato spazio. (bb) il tasso di subsidenza è divenuto inferiore a quello della sedimentazione dei conoidi che possono progradare, confinando la sedimentazione lacustre all’opposto margine della conca. evolution of the vallo di diano basin during the lower part of the middle pleistocene (aa) and from the late part of the middle pleistocene to the holocene (bb). aa: high slip rates of the master fault that borders the graben towards the e are compensated by sedimentation of lacustrine and alluvial fan deposits; due to the high subsidence rate, fan deposition is confined to the active margin of the basin. (bb) a decrease in the subsidence rate with respect to the sedimentation rate of the alluvial fans allows progradation of the latter and consequent narrowing of the area occupied by lacustrine sedimentation, which is now confined to the opposite side of the basin. a. ascione & a. cinque 137 subsidenza (media di 1.8 mm/a nel corso degli ultimi 5000 anni; circa 2 mm/a dal 79 d.c. ad oggi) si registra una progradazione della piana di circa 3 km per i notevoli ritmi di aggradazione causati dagli apporti piroclastici del somma-vesuvio (cinque, 1991). va tuttavia precisato che la progradazione della piana del sarno è avvenuta per impulsi, stasi e temporanee inversioni di tendenza, verosimilmente sotto il controllo di interazioni tra moti verticali, fluttuazioni eustatiche minori e variazioni dei ritmi di apporto sedimentario: ad esempio, alla progradazione occorsa nel primo millennio d.c. fece seguito, in epoca medioevale, un arretramento che riportò ambienti di transizione sulla linea di riva di epoca romana (albore livadie et al., 1989). 1.3 effetti delle fagliazioni sul rilievo gli effetti più diretti e localizzati delle fagliazioni, come la creazione di scarpate e dislivelli regionali, sono stati diversi a seconda dei diversi scenari geomorfologici ricorrenti nella regione. negli ambienti favorevoli alla crescita di falde detritiche e/o colluvionali alla base dei versanti di faglia, ad esempio, la presenza e l’altezza di una scarpata denunciante i rigiochi più recenti della faglia sono condizionate dal rapporto tra il tasso di scorrimento della faglia e la velocità dell’accumulo. in appennino meridionale, l’attività tettonica recente dei lineamenti basali di versanti di faglia quaternari risulta spesso priva di conseguenze topografiche (le scarpatine sono modeste rispetto ai movimenti occorsi) perché i rigetti sono stati mascherati dalla crescita di una falda detritica al piede del versante. dove la mancanza di ripiani stabili e/o la natura più fine dei prodotti di alterazione (o degli output clastici) impedisce o quasi l’ispessirsi di falde al piede dei pendii, i rigiochi più recenti della faglia generatrice si manifestano con scarpatine basali (ovvero poste al limite superiore del tratto con copertura detritica) le cui altezza e pendenza sono proporzionali alla resistenza all’erosione dei litotipi affioranti (fig. 6a). nella regione, casi di maggiore espressione morfologica dei rigetti “recenti” si hanno lungo versanti impostati sui calcari di piattaforma carbonatica e sulle successioni silico-carbonatiche bacinali. essi, di norma, consistono in liscioni poco degradati, di altezza non superiore ad alcuni metri, che cumulano gli effetti di eventi di scorrimento risalenti almeno alla fine dell’ultimo glaciale: esempi se ne rinvengono all’interno del massiccio del m. marzano, ma anche al monte s. giacomo e lungo qualche scarpata di faglia tra quelle che bordano le conche tettono-carsiche di s. gregorio magno e buccino, dove corrono al contatto tra i calcari e i depositi di versante. all’estremo opposto si collocano i casi dei versanti impostati su litologie di alta erodibilità quali, ad esempio, i terreni della coltre sicilide e le porzioni argillose delle successioni dell’avanfossa, dove sono estremamente rari i casi di profili di versante con elementi ripidi basali. ciò suggerisce che, su tali litologie, i tempi necessari alla regolarizzazione del profilo dopo che esso è stato spezzato da un rigetto (tipicamente di ordine decimetrico) sono mediamente inferiori ai periodi di inattività che separano gli eventi di scorrimento delle faglie. questi, per quanto emerge dagli studi paleosismologici condotti negli ultimi anni in appennino meridionale, nel tardo quaternario sono stati di ordine millenario (pantosti & valensise, 1990; pantosti et al., 1993a; 1993b; vittori et al., 1995). ovviamente, nei casi in cui il rapido seppellimento o la rapida erosione dei gradini via via creati dalla faglia consentono il mantenimento di un profilo di versante regolare, all’assenza o labilità di conseguenze topografiche in prossimità della faglia fa riscontro, ad una scala più ampia, il progressivo incremento di altezza del versante, con conseguente rinvigorimento dell’erosione nell’ambito del blocco sollevato (fig. 7a; fig. 8). anche nel caso dei versanti di faglia che bordano aree in aggradazione, quali conche intramontane e graben peritirrenici, l’attività tettonica recente molto spesso non da luogo a manifestazioni topografiche lungo i lineamenti, sebbene ad una scala maggiore essa determini il perpetuarsi dell’aggradazione. infatti, molti dei fig. 5 la risposta dei sistemi di conoide a cessazione della fagliazione (aa) e a disgiunzioni con ritmi bassi rispetto a quelli della sedimentazione (bb). aa) in seguito alla cessazione delle dislocazioni, il conoide (la cui sedimentazione era precedentemente confinata all’area prossima alla faglia) inizia a progradare; parallelamente, l’apice del conoide può incunearsi nella valle determinando, come ulteriore effetto, l’aumento di sinuosità del piede del versante. bb) l’apice di un conoide può incunearsi nella valle anche se la faglia basale è attiva, purché il tasso medio di scorrimento di quest’ultima sia inferiore al tasso di sedimentazione; in questo caso, la sedimentazione al piede del versante seppellisce il nucleo roccioso e le fagliazioni interessano il corpo del conoide: ciò provoca erosione in apice e, ancora, progradazione, ma questa volta causata dall’avanzamento del depocentro del conoide. the response of alluvial fans to ceasing of faulting (aa) and to faulting with rates lower than the rates of deposition (bb). aa) the ceasing of faulting allows progradation of the alluvial fan (formerly, aggradation of the fan prevailed over its progradation due to the high subsidence) and also indentation of the fan apex within the valley, with consequent increase of the sinuosity of the mountain front. bb) the apex of a fan may indent within a valley also if the deposition rate overcomes the average slip rate; in this case, the bedrock fault mirror is buried and faulting propagates upwards to displace the alluvial fan: this triggers both downcutting in the apex and progradation of the fan, which is now due to shifting of the depocentre towards the basin axis. le variazioni geomorfologiche ... 138 versanti bordieri di aree in subsidenza e aggradazione mostrano profili dolci che si sviluppano grazie al fatto che la rapida sedimentazione non consente al gradino tettonico di creare una scarpata basale e, pertanto, di interrompere l’evoluzione del versante. ciò è quanto si osserva, ad esempio, per i versanti che bordano la piana campana, e per quelle, tra le scarpate di faglia delle conche tettono-carsiche di s. gregorio mango e buccino, che bordano le porzioni centrali dei due bacini, a maggiore tasso di sedimentazione. in questi stessi ambienti, invece, si rinvengono scarpate nell’ambito delle coperture, dove sono dovute alla propagazione in superficie delle stesse faglie su cui sono impostati i versanti (fig. 6b). infine, si può osservare che negli scenari in cui l’aggradazione tiene il passo delle disgiunzioni, il rilievo locale può non subire sostanziali variazioni nonostante il perdurare dell’attività tettonica (fig. 7b). 22 ccoonnssiiddeerraazziioonnii ccoonncclluussiivvee pur manifestando solo localmente un paesaggio a forte impronta neotettonica (graben peritirrenici; aree con vulcano-tettonica), l’appennino meridionale è un’area nella quale la tettonica ancora in corso, di tipo estensionale e fragile, è comunque in grado di interferire con le dinamiche esogene e apportare modificazioni al paesaggio. in termini di pericolosità ambientale, la tettonica attiva si esprime innanzitutto con scuotimenti sismici e, talora, con l’avvio di crisi di franosità, oltre che con possibili riflessi sull’attività vulcanica, come nel caso delle eruzioni ignimbritiche che hanno accompagnato alcune fasi di collasso nella piana campana. per quanto concerne le conseguenze di ordine geomorfologico trattate in questa nota, è il caso di fare alcune considerazioni sulla entità dei fenomeni e la loro probabilità di accadimento, pur coi limiti imposti dal fatto che si dispone di dati analitici ancora poco numerosi, che non campionano con adeguata fittezza la complessa regione qui presa in esame e che sono spesso caratterizzati da ampi margini di incertezza. a tal fine va innanzitutto considerato il fatto che la fagliazione superfig. 6 effetti morfologici delle fagliazioni su versanti in rocce resistenti senza accumulo basale (aa) e bordanti piane sede di aggradazione (bb). aa) le disgiunzioni modificano il profilo del versante creando un elemento ripido basale. bb) le disgiunzioni hanno effetto in superficie creando scarpate nella sola copertura, mentre l’addolcimento erosionale del versante non subisce interruzioni. the response to faulting of the profile of resistant bedrock fault scarps in various geomorphological scenarios. (aa) where debris accumulation is impeded, the faulting affects the slope profile by creating a steep basal cliff. (bb) if the fault scarp borders a subsiding depressions where aggradation takes place, faulting affects the surface through creation of scarps (generally multiple) in alluvium; in these cases, the slip events do not modify the bedrock slope profile. fig. 7 aa) anche se il gradino tettonico creato dalla faglia alla base del versante è rapidamente mascherato dall’accumulo di una falda detritica, il rilievo locale risulta comunque incrementato sia per aumento dell’altezza della scarpata (da h1 ad h2), sia per l’approfondimento regressivo dei corsi d’acqua (il profilo longitudinale dei corsi d’acqua passa da f1 ad f2). bb) se l’aggradazione riesce a compensare il tasso di scorrimento della faglia, il gradino che nasce lungo la faglia può venire rapidamente mascherato ed il rilievo locale può anche non aumentare; se poi il tasso di sedimentazione supera quello di scorrimento della faglia, il rilievo locale può addirittura diminuire per aggradazione nei fondivalle (da f1 ad f2). aa) even though the slope deposits cover the newborn scarplet hiding the local effect of the faulting, the increase in the scarp height (from h1 to h2) and the consequent regressive deepening of rivers (long rivers profile change from f1 to f2) result in an increase in the local relief. bb) if aggradation equates the slip rate of the fault, the tectonic scarp can be rapidly buried and the local relief may not be increased; furthermore, if the sedimentation rate is larger than the slip rate, the local relief may decrease in response to valley floor aggradation (long rivers profile change from f1 to f2). a. ascione & a. cinque ficiale nella quale si esprime l’attuale regime estensionale si distribuisce su un numero elevato di lineamenti ad attività diacrona, per cui ciascun lineamento registra eventi di scorrimento separati da intervalli di inattività piuttosto lunghi. i singoli eventi di scorrimento (slip event) non sono superiori ad alcuni decimetri e, sulla stessa faglia, essi ricorrono con intervalli di ordine millenario. tralasciando le ben note conseguenze di ordine ingegneristico (danneggiamenti a edifici e infrastrutture) a vantaggio di quelle di ordine geomorfologico (variazioni ambientali), va osservato che eventi dislocativi della entità sopracitata hanno -nel breve termine e in un’ottica antropocentricaconseguenze morfodinamiche trascurabili se vanno ad interessare versanti ed aree interfluviali. i moti verticali associati ai singoli slip event, sebbene di ordine al più decimetrico, possono invece determinare conseguenze sensibili se vanno ad interessare aree costiere a bassa elevazione e gradiente (sommersione e impaludamenti a seguito di ribassamento), oppure fondivalle fluviali a basso gradiente (allagamento o impaludamento di tratti basculati verso monte o posti a monte di settori in relativo sollevamento). sebbene per la regione in esame siano note, anche per tempi storici, sia eventi di istantanea fagliazione superficiale (legate a crisi sismiche particolarmente intense, come quella del 1980) che rapide variazioni ambientali del tipo appena descritto, non sono noti casi di sicura e diretta relazione causa-effetto tra le due tipologie di fenomeni. tale mancato riscontro è, almeno in parte, imputabile al fatto che entrambi i “cataloghi” sono incompleti e soprattutto che non è stata ancora effettuata una approfondita ed estesa ricerca (geologico-geomorfologica, ma anche archivistica e storico-geografica) capace di riconoscere le eventuali concomitanze tra eventi tettonici e geomorfologici. un discorso a parte meritano le aree vulcaniche (vulcani continentali ed insulari dell’area campana) in quanto esse sono state, e possono essere, affette da moti verticali e fagliazioni decisamente più rapide di quelle imputabili a tettonica regionale. vistosi esempi di grandi modifiche del paesaggio, anche in epoca storica, sono offerti dall’area flegrea e dall’isola di ischia: in quest’ultima, linee di riva di età romana si rinvengono a + 25 m (cinque et al., 1997), mentre nell’area del golfo di pozzuoli il terrazzo marino de la starza, emerso dal mare intorno a 5000 anni fa, è stato sollevato sino a circa 60 m di quota e reca scarpate di faglia alte anche alcune decine di metri (cinque et al., 1985). nella stessa area, tracce della linea di riva di epoca romana imperiale si rinvengono fino a – 10 m e quelle di epoca medioevale intorno a – 5 m (cinque et al., 1997); analogamente, a collassi di ordine vulcano-tettonico potrebbe ascriversi anche il ribassamento di circa 4 m manifestato dalla linea di riva romana decorrente sulle pendici sud-occidentali del vesuvio (siti archeologici di ercolano e pompei; cinque & russo, 1986). llaavvoorrii cciittaattii albore livadie c., barra d., bonaduce g., brancaccio l., cinque a., ortolani f., pagliuca s. & russo f. (1989) evoluzione geomorfologica, neotettonica e vulcanica della pianura costiera del fiume sarno (campania) in relazione agli insediamenti anteriori all’eruzione del 79 d.c.. vulcan. paleog. archeol., pact, 1100. amato a., ascione a., cinque a. & lama a. (1991) morfoevoluzione, sedimentazione e tettonica recente dell'alta piana del sele e delle sue valli tributarie. geogr. fis. e dinam. quat., 1144, 5-16. ascione a. & cinque a. (1997) le scarpate su faglia dell’appennino meridionale: genesi, età e significato tettonico. il quaternario, 1100, no. 2, 285-292. ascione a., cinque a., improta l. & villani f. (2003) late quaternary faulting within the southern apennines seismic belt: new data from mt. marzano area (southern italy). quaternary international, 110011--110022, 27-41. 139 fig. 8 effetti delle fagliazioni sul rilievo a diverse scale, in aree oggetto di erosione con alti ritmi. nel riquadro, da 1 a 3, la nascita e cancellazione del gradino creato da uno scatto della faglia attiva. sebbene i gradini via via creati vengano cancellati, il cumularsi delle disgiunzioni provoca un aumento del rilievo a più ampio raggio (da h1 ad h2); la naturale tendenza all’approfondimento del reticolo nel blocco relativamente sollevato può fornire un ulteriore contributo all’aumento del rilievo locale (cf. profili topografici aa e bb). the response of the landscape to faulting on various scales, in areas subject to erosion with high rates. in the little frame, from 1 to 3, the formation and cancellation of a scarplet due to a faulting event. notwithstanding the cancellation of the single steps, the summation of slip leads to an increase in the relief on a wide range (from h1 to h2); a further contribution to the increase in the local relief is offered by rivers downcutting (see profiles aa to bb). le variazioni geomorfologiche ... barra d., romano p., santo a., campajola l., roca v. & tuniz c. (1996) the versilian transgression in the volturno river plain (campania, southern italy): palaeoenvironmental history and chronological data. il quaternario, 99, no. 2, 445-458. brancaccio l., cinque a., di crescenzo g., santangelo n. & scarciglia f. (1997) alcune osservazioni sulla tettonica quaternaria nell’alta valle del f. volturno. il quaternario, 1100, no. 2, 321-328. brancaccio l., cinque a., romano p., rosskopf c., russo f., santangelo n. & santo a. (1991) geomorphology and neotectonic evolution of a sector of the tyrrhenian flank of the southern apennines (region of naples, italy). zeit. geomorph., suppl. -bd. 8822, 47-58. caiazzo c. (2000) l’evoluzione tettonica del margine tirrenico dell’appennino campano-lucano; ricostruzione dei paleostress e analisi morfostrutturale. tesi di dottorato. università degli studi di napoli “federico ii”. cello g., guerra i., tortorici l. turco e. & scarpa r. (1982) geometry of the neotectonic stress field in southern italy: geological and seismological evidence. j. struct. geol., 44, 385-393. cinque a. (1991) la trasgressione versiliana nella piana del sarno (campania). geogr. fis. e dinam. quat., 1144, no. 1, 63-71. cinque a., ascione a. & caiazzo c. (2000) distribuzione spazio-temporale e caratterizzazione della fagliazione quaternaria in appennino meridionale. in f.galadini, c. meletti, a. rebez (eds.) “ricerche del gndt nel campo della pericolosità sismica (1996-1999)”. cnr-gndt spec. publ., 203-218, roma. cinque a., aucelli p.p.c., brancaccio l., mele r., milia a., robustell i g., romano p., russo f., santangelo n. & sgambati d. (1997) volcanism, tectonics and recent geomorphological change in the bay of napoli. i.a.g. iv int. conf. on geomorphology, geogr. fis. din. quat., suppl. iiiiiit.2, 123-141. cinque a., rolandi g. & zamparell i v. (1985) l’estensione dei depositi marini olocenici nei campi flegrei in relazione alla vulcano-tettonica. boll. soc. geol. it., 110044, 327-348. cinque a. & russo f. (1986) la linea di costa del 79 d.c. fra oplonti e stabiae nel quadro della evoluzione olocenica della piana del sarno (campania). boll. soc. geol. it., 110055, 111-121. d’addezio g., pantosti d. & valensise g. (1991) paleoearthquakes along the irpinia fault at pantano di san gregorio magno (southern italy). il quaternario, 44, no. 1a, 121-136. de vivo b., rolandi g., gans p.b., calvert a., bohrson w.a., spera f.j., belkin h.e. (2002) new constraints on the pyroclastic eruptive history of the campanian volcanic plain (italy). mineralogy and petrology, 7733, 47-65 gasparini c., iannaccone g. & scarpa r. (1985) faultplane solution and seismicity of the ital ian peninsula. tectonophysics, 111177, 59-78. hippolyte j.c., angelier j. & roure f. (1994) a major geodynamic change revealed by quaternary stress patterns in the southern apennines (italy). tectonophysics, 223300, 199-210. karner d., russo ermolli e., juvigné e., bernasconi s., brancaccio l., cinque a., lirer l., ozer a. & santangelo n. (1999) a middle pleistocene tephrostratotype: the vallo di diano (campania, italy). global and planet. change, 2211, 1-15. ippolito f., ortolani f. & russo m. (1973) struttura marginale tirrenica dell’appennino campano: reinterpretazione di dati di antiche ricerche di idrocarburi. mem. soc. geol. it., 1122, 227-250. munno r., petrosino p., romano p. & russo ermolli e. (2001) a late middle pleistocene climatic cycle in southern italy inferred from pollen analysis and tephrostratigraphy of the acerno lacustrine succession. géographie physique et quaternarie, 5555, no. 1, 1-37. pantosti d., d’addezio g. & cinti f. (1993a) paleoseismological evidence of repeated large earthquakes along the 1980 irpinia earthquake fault. ann. geofis., 3366, no. 1, 321-330 pantosti d., schwartz d.p. & valensise g. (1993b) paleoseismology along the 1980 surface rupture of the irpinia fault: implications for earthquake recurrence in southern apennines, italy. jour. of geophys. res., 9988, no. b4, 6561-6577. pantosti d. & valensise g. (1990) fault ing mechanisms and complexity of the november 23, 1980, campania lucania earthquake, inferred from surface observations. jour. of geophys. res., 9955, no. b10, 15.319-15.341. patacca e. & scandone p. (1999) late thrust propagation and sedimentary response in the thrust belt – foredeep system of the southern apennines (pliocene – pleistocene). in g.b. vai & i.p. martini (eds) – anatomy of a mountain system: the apennines and the adjacent mediterranean basin. chapman & hall publ. 1999. in stampa. romano p., santo a. & voltaggio m. (1994) l’evoluzione geomorfologica della piana del fiume volturno (campania) durante il tardo quaternario (pleistocene medio-superiore olocene). il quaternario, 77, no.1, 41-56. santangelo n. (1991) evoluzione stratigrafica, geomorfologia e neotettonica di alcuni bacini lacustri del confine campano lucano (italia meridionale). tesi di dottorato, università degli studi di napoli “federico ii”. santangelo n. (2003) interazione tra tettonica recente e processi geomorfici. questo volume. scandone p. (ed.) (1983) structural model of italy. sottoprogetto “modello strutturale tridimensionale” in f. barberi (ed.) “progetto finalizzato geodinamica”, c.n.r.. vittori e., ferreli l., michetti a.m. & serva l. (1995) holocene paleo-earthquakes along the pollino fault zone (northern calabria, italy): implications for seismic hazard assessment. 5th int. conf. on seismic zonation, nice oct. 17-19, 1995, 14001407. ovest editions, presses académiques. westway r. & jackson j.a. (1987) the earthquake of 1980 november 23 in campania-basil icata (southern italy). jour. of struct. volcanol. & geotherm., 4488, 127-137. 140 ms. ricevuto il 7 gennaio 2003 testo definitivo ricevuto il 1° luglio 2003 ms. received: january 7, 2003 final text received: july 1, 2003 a. ascione & a. cinque amq 712 iannucci et al 36,1 75-90.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 36 (1), 2023, 75-90 1. introduction during the quaternary, marked climatic and environmental changes took place at a global scale, most notably affecting meteorological and oceanographic circulations, the intensity of the glacial activity in the northern hemisphere, and the frequency and amplitude of oscillations between cool-arid and warm-humid conditions (shackleton, 1995; flesche kleiven et al., 2002; gibbard et al., 2005; ehlers & gibbard, 2007; etourneau et al., 2010; gibbard & head, 2020). in turn, these changes promoted substantial reorganizations of the large mammal fauna. forty years ago, azzaroli (1983) recognized and named three major “dispersal events” (repenning, 1967, 1980), referring to them as “short periods of rapid intercontinental migrations and faunal replacements” (azzaroli, 1983, p. 117), namely the “elephant-equus event” (between 3.0 and 2.5 ma), the “wolf event” (~1.7 ma), and the “end-villafranchian dispersal event” (~1.0-0.9 ma). in the following years, the proposed timing of these events was further discussed and refined (azzaroli et al., 1988; azzaroli, 1995; gliozzi et al., 1997), eventually correlating the elephantequus event with what is currently recognized as the pliocene-pleistocene transition (~2.6 ma), the wolf event with the gelasian-calabrian transition (~1.8 ma; the pliocene-pleistocene boundary prior to 2009), and the end-villafranchian event with the early-middle pleistocene transition (~0.8 ma). whilst azzaroli (1983) regarded the aforementioned dispersal events as moments of marked faunal renewals and recognized in some cases the gradual character of the associated turnover, the approximate synchronicity between dispersal events and relevant geological transitions exacerbated their geochronological importance. this resulted in a widespread use of the appearance of the “representative” species after which the events were named (e.g., the genus equus for the elephant-equus event) as a stratigraphic datum (see iannucci & sardella, 2023, for discussion). essentially, there are at least two aspects of azzaroli’s dispersal events that resulted in ambiguous applications. first, https://doi.org/10.26382/amq.2023.03 beware of the “wolf event” remarks on large mammal dispersals in europe and the late villafranchian faunal turnover alessio iannucci, beniamino mecozzi, raffaele sardella dipartimento di scienze della terra (paleofactory lab.), università sapienza, roma, italy. corresponding author: a. iannucci <alessio.iannucci@uniroma1.it> abstract: the “wolf event” is a prominent concept in large mammal biochronology of western europe. it was defined in the 1980s as an intercontinental “dispersal event”, best represented by the arrival of a “primitive wolf”, canis etruscus, but also involving other species. the wolf event denoted the late villafranchian faunal turnover, first expressed in italy in the olivola faunal unit. this event was also considered approximately coincident with the pliocene-pleistocene boundary adopted prior to 2009 (~1.8 ma, gelasian-calabrian transition), hence indicating important environmental changes and representing a relevant tool for correlation. whilst it became soon clear that sporadic finds of modern canids (and, to some extent, other species) pre-dated the age assumed for the wolf event, several authors continued to use the term and to associate it to the late villafranchian, referring to the “massive expansion” of the species involved, rather than their first appearance in the european fossil record. several bioevents traditionally included in the wolf event and others that have been considered to occur later are today already documented in middle villafranchian faunas. the “pachycrocuta brevirostris event”, proposed as a replacement term for the wolf event, based on current evidence would be characterized by the arrival in europe of the giant hyena p. brevirostris and panthera gombaszoegensis, and the increase in the documentation of other species traditionally included in the wolf event. however, this does not correspond to a sharp faunal turnover as traditionally envisioned for the wolf event and it is possibly heralded in faunas slightly older than olivola at ~2.0 ma. in other terms, available evidence highlights the rather diachronic nature of large mammal dispersal occurred in the late middle and early late villafranchian (late gelasian, ~2.2–1.8 ma), pushing to critically evaluate the biochronological, paleoecological, and paleobiogeographical significance of each bioevent. for instance, the arrival of hippopotamus in europe is now attested since ~2.2 ma, documenting an african dispersal of a species linked to humid conditions in a context that is generally deemed to denote the spread of open-adapted faunal elements of mainly asian affinities. keywords: biochronology, bioevent, faunal renewal, pleistocene, villafranchian. 76 iannucci a. et al. although named after one or few taxa, these periods of faunal turnover involved, by definition, many species. second, they were envisioned as “short”, but not properly geologically instantaneous intervals. to this list can be added that azzaroli (1983) emphasized the link between faunal and environmental changes, or, in other terms, he inherently included a paleoecological component in the biochronological event. of course, this is not to say that implementations of the dispersal event concept with a meaning that deviate from that used by azzaroli (1983) are necessarily wrong. indeed, as in general for other biochronological terms, concepts, principles, and practices, they are not formally defined within a stratigraphic code, which means that there exist a (legit) variety of approaches among different researchers (e.g., gradstein et al., 1985; lindsay, 2003; palombo & sardella, 2007; palombo, 2009). however, this unavoidably leaves room for ambiguity, most notably when divergent adoptions of a dispersal event are discussed as if referring to the same thing, while different authors might have invested the same term with different meanings. conceptual dichotomies aside, over the years several discoveries have pushed to reconsider the timing of specific bioevents (i.e., those linked to a single taxon), and thus, partly depending on the different acceptances with which azzaroli’s dispersal events have been used, authors opinions diverge as to whether reinterpret, reimagine, or abandon the use of specific dispersal events. the wolf event played a special role in quaternary large mammal biochronology, especially in western europe (fig. 1), given the approximate coincidence between this event (in its original formulation) and the formerly adopted pliocene-pleistocene boundary at ~1.8 ma (i.e., prior to the placement of the pleistocene epoch/series at ~2.6 ma, in 2009; aguirre & pasini, 1985; pillans, 2004; clague, 2006; gibbard & head, 2010; gibbard et al., 2010; head & gibbard, 2015; capraro & maiorano, 2023). here, using the wolf event as a case study, we offer a discussion, partly conceptual, partly factual, on the dispersal of wolf-like canids into europe and on some other specific bioevents currently recognized to have occurred in the late middle and late villafranchian (late gelasian, ~2.2–1.8 ma) that have been the subject of debate and in some instances considered in the framework of the wolf event. 2. the “wolf event” azzaroli (1983) remarked that turnover associated with the wolf event was overemphasized in the italian fossil record due to the lack of middle villafranchian faunas, but he included in the wolf event the arrivals of leptobos etruscus (replacing l. stenometopon), sus strozzii, pachycrocuta brevirostris, and canis etruscus. the latter is the “wolf” after which the event was named. this turnover would correspond to the beginning of the late villafranchian, and to the olivola faunal unit (fu). other groups of canis were considered to appear only in fig. 1 main fossiliferous localities mentioned in this work: 1 fonelas p-1; 2 la puebla de valverde; 3 perrier-les etouaires, rocaneyra; 4 senèze; 5 vialette; 6 saint vallier; 7 oosterschelde; 8 olivola, quercia; 9 valdarno superiore (several localities); 10 montagnola senese; 11 vigna nuova, chiusi basin, torre picchio; 12 monte riccio; 13 bocchignano, castel san pietro; 14 coste san giacomo, fontana acetosa; 15 elis, aetorráchi, hághios demétrios, 16 gerakarou 1. 77 “wolf event” and large mammal dispersal and the proper spread of the group since the beginning of the late villafranchian. further evidence of middle villafranchian canis has piled up in the following decades, some of which perhaps related to wolf-like canids, either deriving from the subsequent tasso fu (azzaroli, 1983). azzaroli et al. (1988) remarked the coincident disappearance of nyctereutes and gazella, the appearance, possibly related to evolutionary changes, of eucladoceros dicranios and dama nestii (currently often referred to ‘pseudodama’, see cherin et al., 2022, and references therein), and the arrival of another species, panthera toscana (today referred to p. gombaszoegensis), alongside the bioevents previously recognized. concerning the latter, however, azzaroli et al. (1988, p. 84) referred to the “massive expansion in europe” of the considered species, rather than their earliest appearance in the fossil record, again leaving room for divergent interpretations. therefore, there are different aspects of azzaroli’s wolf event that need to be critically evaluated based on the available evidence. it is worth considering: first, whether the dispersal of wolf-like canids in europe is coincident with the beginning of the late villafranchian in correspondence of the olivola fu or not; second, how many of the aforementioned bioevents are indeed part of the same “dispersal event”. in the following, these two points are briefly discussed. when azzaroli (1983) schematized the wolf event and placed it in correspondence of the olivola fu, remains of possibly older canis were already known at least from the french site of senèze (martin, 1973), but the chronological consistency of the faunal assemblage recovered from this locality was often doubted (masini & torre, 1990; mazza & rustioni, 1994; rook & torre, 1996). further canid remains were recovered from coste san giacomo (predating olivola and now dated at ~2.2 ma, florindo et al., 2021; coste san giacomo fu) and attributed to canis etruscus by rook & torre (1996), in line with ongoing investigation. rook & torre (1996) also reported the presence of a partial hemimandible of a canid recovered from quercia (near olivola and stratigraphically lower than it; iannucci, 2023), accepted a middle villafranchian age for the canids of senèze, and concluded that the earliest dispersal of modern dogs occurred during the middle villafranchian. nonetheless, rook & torre (1996, p. 499) argued that “the meaning of the “wolf-event” for the beginning of the late villafranchian does not loose its value of “faunal event” in the sense of marked change in faunal assemblages”. in the seminal synthesis on italian biochronology by gliozzi et al. (1997), the status of the wolf event was not directly discussed, but the authors reiterated the first occurrence of wolf-like canids (c. etruscus) in italy from the middle villafranchian of coste san giacomo fig. 2 distribution of canis (a) in the middle villafranchian of western europe: 1 coste san giacomo, fontana acetosa; 2 oosterschelde; 3 roca-neyra; 4 senèze; 5 chilhac 2; 6 saint vallier; 7 quercia; 8 montagnola senese; 9 vigna nuova, torre picchio. silhouettes of canids modified from: iurino et al. (2022; canis etruscus, canis sp.); bartolini lucenti & spassov (2022; canis (x.) lycanoides); wikimedia commons (https://commons.m.wikimedia.org/wiki/file:canis_arnensis_restoration.jpg; canis arnensis). distribution of hippopotamus (b) in the middle villafranchian of western europe: 1 senèze; 2 chiusi basin; 3 castel san pietro; 4 coste san giacomo, fontana acetosa; 5 hághios demétrios, aetorráchi. silhouette of hippopotamus modified from phylopic, by zimices (phylopic.org/image/c2d68ebb-50ec-45f48cd1-6cf52ad02286). new discoveries or reconsiderations of old collections (fig. 2a). two lower incisors assigned to canis sp. were reported by fondi (1972) from montagnola senese, whose fauna has been referred to the coste san giacomo fu (bona et al., 2015). a fragmentary premolar and a portion of a distal metapodial of canis sp. are known from torre picchio (girotti et al., 2003), also referred to the coste san giacomo fu (bona et al., 2015). during the revision of the carnivoran record of saint vallier, argant (2004) identified the presence of a partial neurocranium referable to the genus canis. the locality is customarily biochronologically placed between montopoli and coste san giacomo fus, with estimated ages ranging from 2.5 to 2.0 ma (viret, 1954; azzaroli, 1970, 1977; torre et al., 1992; gliozzi et al., 1997; guérin, 2004; nomade et al., 2014; brugal et al., 2020). reumer & piskoulis (2017) assigned to canis cf. etruscus a mandibular fragmented recovered from the oosterschelde estuary, whose early pleistocene fossil fauna, although resedimented in late pleistocene deposits and collected during dredging activity, is referred to the middle villafranchian, or to ~2.4–2.1 ma (scager et al., 2017). azzarà et al. (2022) described a portion of the axial skeleton of a single individual of canis sp. recovered from the middle villafranchian (coste san giacomo fu) site of vigna nuova, considering it very similar to comparable material of c. etruscus known from olivola (torre, 1967). finally, concerning the long debate on the possibility of age heterogeneity in the faunal assemblage from senèze (see delson et al., 2006), pastre et al. (2015) performed 40ar/39ar datings that constrain the sequence between ~2.2 and 2.09 ma. recently, u-pb dating on volcanic zircons was also applied at senéze, with results providing a mean age of of 2.100 ± 0.029 ma (paquette et al., 2021). an even older record of canis sp. would be that of vialette (heintz et al., 1974), which lacombat et al. (2008) referred to 3.14 ma. however, the attribution of the material and the chronology of the site have been contested. the problems concerning the chronology of the site or, more precisely, the mixing of different faunal elements among those labelled as from vialette in the collection of the musée crozatier (le puy-en-velay), has been commented by several authors (guérin, 2005; van der made et al., 2014; palombo & alberdi, 2017). perhaps the clearest example of chronological heterogeneity is represented by the identification of some remains belonging to late miocene suids, namely assigned to listriodon and cf. “microstonyx” major (van der made 2005; van der made & moullé, 2005), the latter species being more commonly placed in hippopotamodon in recent literature (iannucci et al., 2021a). as for the taxonomic attribution of the canid material to canis, lacombat et al. (2008, p. 67) argued that: “the morphology, the size and the proportions of these remains allow us to exclude genera occurring in the early pliocene”, while böhme et al. (2021) recently suggested it could rather belong to eucyon. on the other hand, böhme et al. (2021) reported material of wolf-like canids from perrier-les etouaires, referring it to 2.78 ma following nomade et al. (2014). this chronology calls for further discussion. nomade et al. (2014) provided this age for pumices of la côte d’ardé, which they considered stratigraphically close to perrier-les etouaires “classical site”. however, as pointed out by iannucci & sardella (2023), this age cannot be accepted uncritically for all the mammal remains recovered from perrier-les etouaires. indeed, it is known that the fauna of perrierles etouaires contains early villafranchian and middle villafranchian species, which originated from layers of different ages (poidevin et al., 1984; palombo & valli, 2004). in any case, following the dating and correlations proposed by nomade et al. (2014) for the entire area of perrier, the fossil findings should be constrained between ~3.1 and 2.6 ma, an age that would be thus enough to make the record of wolf-like canids from perrier-les etouaires reported by böhme et al. (2021) the earliest (excluding vialette) in europe (iannucci & sardella, 2023), although the material has not been described. indeed, the presence of canis aff. etruscus from etouaires was reported by heintz et al. (1974) based on material part of the bravard collection housed in the british museum listed by lydekker (1885, p. 126). however, the material mentioned by lydekker (1885) is possibly from younger deposits at tour-de-boulade, and indeed the author considered it undistinguishable from c. lupus. this view was reaffirmed by torre (1979), who stated that these fossils were of large size, similar to that observed in wolves of the last glaciations (which would correspond to the second part of late pleistocene). marciszak et al. (2023) also reported unpublished material of canis cf. etruscus from węże 2, referring it to 2.9–2.6 ma, also listing further material from poland potentially of middle villafranchian age. in sum, while the evidence for some of the aforementioned findings might not be conclusive, it has long been quite clear that the arrival of wolf-like canids in europe is at least as early as the coste san giacomo fu (middle villafranchian), and there is further putative evidence that would suggest an even older age. it is worth reiterating that the occurrence of wolf-like canids already in the middle villafranchian did not discourage several authors to continue using the wolf event to refer to the late villafranchian faunal turnover as a whole, emphasizing the increase in the abundance of wolf-like canids, rather than their earliest appearance in the fossil record (e.g., rook & torre, 1996). this late villafranchian “massive expansion”, as it has been referred to by azzaroli et al. (1988) and generally agreed in subsequent research (e.g., gliozzi et al., 1997), is well documented in italy, for instance by historical samples from olivola and the upper valdarno, and by the abundant record of pantalla (cherin et al., 2013, 2014). 3. the “hippo event” the earliest dispersal of hippopotamus in europe was not among the bioevents listed by azzaroli (1983) as part of the wolf event, but we consider particularly appropriate to discuss it here as there is now evidence of late middle villafranchian (late gelasian) hippopotamuses from several european localities, some of which also yielded early canis (fig. 2b). in particular, a fragmentary incisor of hippopotamus sp. is known from coste san giacomo (bellucci et al., 2012, 2014; sardella, 2012). the age of the fossil horizon was consid 78 iannucci a. et al. chian hippopotamus in europe (dated at ~2.2 ma), but it is not the only. cassoli & segre naldini (1984) listed hippopotamus sp. among the faunal remains recovered from fontana acetosa, like coste san giacomo, another locality of the anagni basin in central italy. the authors remarked the similar nature of the fossiliferous levels of coste san giacomo and fontana acetosa, yellow sands, although somewhat more clayey at fontana acetosa, but did not exclude the possibility of a slightly younger age for the latter site. the presence of hippopotamus seemed indeed at odds with the then accepted first appearance of the species in the tasso fu (azzaroli, 1983). when bellucci et al. (2012) recognized the presence of hippopotamus at coste san giacomo, they also accepted the correlation between the two sites, although the fauna of fontana acetosa would be in need of a systematic study to clarify the biochronological value of the species reported. during the revision of the fossil collection stored at faculté des sciences de l'université claude bernard, lyon i, a first phalange (fsl 211082), previously ascribed to equus sp., was attributed to hippopotamus cf. antiquus by mazza & rustioni (1994). the fossil was recovered from domeyrat, one of the toponyms generally considered as part of senèze locality. the presence of hippopotamuses at senèze was previously listed by jung (1946) and bout (1960), but then excluded from subsequent faunal lists (e.g., heintz et al., 1974), possibly due the supposedly later arrival of hippopotamus in europe. it seems conceivable that reports older than the work by mazza & rustioni (1994) were based on further undescribed material and, in any case, even after that mazza & rustioni (1994) reaffirmed the occurrence of hippopotamuses at senèze, these were seldom considered in subsequent biochronologic schemes (but see arribas et al., 2009), likely due to the uncertainty on the chronology of the locality (see previous section above). nonetheless, as discussed in the previous section, several radiometric estimates now constrain the succession of senèze at ~2.2–2.1 ma (nomade et al., 2014; pastre et al., 2015; paquette et al., 2021), approximately coeval with coste san giacomo. several findings of middle villafranchian hippopotamuses are known from the area of elis, in greece, as recently reviewed by athanassiou (2022). these remains include: dentognathic material described by thenius (1955), which according to athanassiou (2022) can be considered of earliest pleistocene age owing to invertebrate biochronology; further osteological and dental finds mentioned by symeonidis & theodorou (1986) from hághios demétrios; a juvenile fragmented cranium from aetorráchi (reimann & strauch, 2008). other hippopotamus remains attributed to h. antiquus were recovered from the chiusi basin (cuscani politi, 1966, 1971; mazza, 1995; pandolfi & petronio, 2015). an accompanying faunal assemblage was also reported by pandolfi & petronio (2015), including gazella sp., axis (=‘pseudodama’) cf. nestii and eucladoceros sp., although not described and made up of surface finds, the authors referred it to the coste san giacomo or olivola fus. the occurrence of gazella would point towards the former, considering that the taxon is not recorded in italian localities younger than the coste san ered around 2.1 ma by bellucci et al. (2014), based on magnetostratigraphy, pollen, and small mammals, and further refined at ~2.2 ma by florindo et al. (2021). bellucci et al. (2012) firstly identified the specimen as belonging to a hippopotamus, although a more precise taxonomic attribution is clearly precluded by the scanty nature of the sample. sardella et al. (2018) clarified that the hippopotamus incisor from coste san giacomo was not collected during systematic excavations but is part of the 1980s field collection, causing some authors to doubt the age of the finding (marra et al., 2018; martino & pandolfi, 2022). however, field activities and excavations at coste san giacomo co-directed by one of us (rs) have pointed out that the vertebrate assemblage comes from a single fossiliferous level, from which the old collections can also be related (bellucci et al., 2012, 2014; bona et al., 2015; strani et al., 2015; palombo et al., 2017). it is worth noting that the fauna of coste san giacomo has long been considered a homogeneous assemblage, besides representative of the homonymous fu, the latest of the middle villafranchian (gliozzi et al., 1997). the reason why the hippopotamus record of coste san giacomo has often been considered controversial (e.g., martínez-navarro et al., 2015; pandolfi & petronio, 2015) seems rather contingent. traditionally, the earliest occurrence of hippopotamus in italy was placed in the tasso fu, based on several historical findings from the upper valdarno (nesti, 1820; leonardi, 1947; azzaroli, 1977; gliozzi et al., 1997). napoleone et al. (2003) suggested that the hippopotamuses might be of a younger age than that of the rest of the main upper valdarno fauna, considering the lack of their remains among those collected during modern excavations in the area. this possibility was also previously evoked by faure (1985) and mazza (1991). it is worth noting that most of the fossils from the upper valdarno is part of historical collections gathered at least since the nineteenth century (rook et al., 2013). moreover, the absence of hippopotamus remains from certain deposits might also be related to their ecological requirements, namely their sensitivity to the presence and amount of water (mazza & bertini, 2013). martínez-navarro (2004, 2010) and rook & martínez-navarro (2010), following the suggestion of napoleone et al. (2003) on the younger age of the upper valdarno hippopotamuses, remarked that consequently venta micena yielded the oldest european record of hippopotamus antiquus (although other older records were known, e.g., that from monte riccio, mazzini et al., 2000). mazza & bertini (2013, p. 195) also argued that “the first certified occurrence of hippopotamus antiquus is from the early pleistocene locality of venta micena”, but not excluding the occurrence of earlier findings of uncertain taxonomic status (e.g., the authors quoted fontana acetosa). in brief, the finding of the hippopotamus of coste san giacomo was published at a time when some researchers were hypothesizing a later chronology for the arrival of hippopotamus into europe (bellucci et al., 2012; sardella, 2012). this was, however, not universally accepted (e.g., arribas et al., 2009). in general, the finding of coste san giacomo represents the earliest occurrence of a middle villafran 79 “wolf event” and large mammal dispersal 80 giacomo fu (masini et al., 2013; bellucci & sardella, 2015). the scheme proposed by azzaroli (1983) featured the first appearance of hippopotamus in the tasso fu, which has been most influential in the biochronological correlation of several faunas. the implications for the inferred age of three localities are especially worth mentioning here, recognizing the presence of hippopotamuses in europe already in the middle villafranchian, namely castel san pietro, bocchignano, and monte riccio (all in italy). at castel san pietro, several fossil mammal remains were collected and partly described during the nineteenth century, as a by-product of the exploitation of a lignite mine (tuccimei, 1889a, 1889b, 1891, 1898; maxia 1949). the presence of hippopotamuses from the area of castel san pietro was reported by meli (1882) and tuccimei (1891). pandolfi et al. (2017) carried out a revision of the scanty mammal remains, and further analysis based on ostracods and paleofloristic remains. their results converged to suggest a gelasian deposition of the lignite beds of castel san pietro (~2.5–1.8 ma) in a warm-humid and forested area. concerning the hippopotamuses, the authors casted doubt on their association with the rest of the fauna and commented that the whereabouts of the material are unknown. marra et al. (2018) argued for the presence of two different assemblages at castel san pietro, the older with anancus arvernensis, the younger with h. antiquus. nonetheless, the cooccurrence of a. arvernensis and hippopotamus cannot be ruled out and, if confirmed, would point to a reference to the coste san giacomo fu, as exemplified by the record from the reference fauna of this fu (bellucci et al., 2014). bocchignano is another site whose hippopotamuses remains have been considered indicative of faunal mixing (marra et al., 2018). the fossil remains recovered from the site were reported and described by tuccimei (1889b, 1891, 1893). kotsakis (1988) revised the taxonomic attribution of the arvicoline rodents, referring them to mimomys polonicus or mimomys pliocaenicus. recently, marra et al. (2018) suggested the presence of two different assemblages, the oldest with mimomys (saint vallier to olivola fus), the youngest with hippopotamus (tasso fu). as in the case of castel san pietro, the cooccurrence of the two species is arguably conceivable (if the arvicoline belongs to m. pliocaenicus) and in agreement with a correlation of the fauna with the coste san giacomo or olivola fus (bellucci et al., 2014; bona et al., 2015). unlikely of middle villafranchian age but worth of consideration here is the diverse fauna of monte riccio, including prolagus sp., cf. mammuthus meridionalis, sus strozzii, h. antiquus, leptobos cf. etruscus, procapreolus sp., eucladoceros ctenoides, axis (= ‘pseudodama’) nestii, stephanorhinus cf. etruscus, equus stenonis, vulpes cf. alopecoides, canis etruscus, and megantereon cultridens (mazzini et al., 2000). indeed, this assemblage has been referred to the tasso fu due to the presence of h. antiquus (mazzini et al., 2000; marra et al., 2018), while croitor (2012) suggested a correlation with the olivola fu or even a slightly older age, based on the ruminants. in brief, there is evidence for a middle villafranchian dispersal of hippopotamus into europe ~2.2–2.1 ma, partly documented by remains collected from some of the localities that have been also important to recognize an earlier (than what proposed by azzaroli, 1983) arrival of modern canids, namely coste san giacomo and senèze. the “hippo event” is of paleobiogeographic and paleoecological relevance, in that it testifies to the dispersal into europe of a taxon of clear african origin and of distinct ecology. indeed, though not necessarily limited to warm environments, remains of hippopotamus are indicative of the presence of permanent water bodies and humid climatic conditions (candy et al., 2006, 2010; bellucci et al., 2012; russo ermolli et al., 2010; mazza & bertini, 2013; adams et al., 2022). moreover, morphological considerations and dietary proxies suggest that h. antiquus was even more adapted to an aquatic lifestyle than h. amphibius (palmqvist et al., 2003, 2008; adams et al., 2022). as mentioned previously, perhaps these ecological requirements explain the patchy distribution of middle and late villafranchian occurrences of hippopotamuses in europe, whereas since ~1.5 ma hippopotamus become a common element of the european terrestrial ecosystems (caloi et al., 1980; faure, 1985; kahlke, 1989, 2001; mazza, 1991, 1995; kahlke et al., 2011; van der made et al., 2017; fidalgo et al., 2021; mecozzi et al., 2021; adams et al., 2022; strani et al., 2022). in this regard, it is worth mentioning that paleoenvironmental reconstruction based on ungulate dietary adaptations attest the presence of humid subtropical-like environments at coste san giacomo (strani et al., 2015), whereas comparable analyses point to the occurrence of more open conditions at olivola, where no hippopotamuses are known (strani et al., 2018). 4. other bioevents apart from the arrival of c. etruscus, several other bioevents were listed by azzaroli (1983) and azzaroli et al. (1988) as part of the wolf event, and others have been proposed and discussed over the years. in particular, azzaroli (1983) listed l. etruscus, s. strozzii, and p. brevirostris. the giant hyena is the only species of this contingent whose first appearance in europe is still related to the late villafranchian faunal turnover (see section 5). indeed, while the “massive expansion” (azzaroli et al., 1988) of l. etruscus and s. strozzii can still be placed in correspondence of olivola and tasso fus, remains of both species are already documented in middle villafranchian faunas (masini & sala, 2007; cherin et al., 2018, 2019; iannucci et al. 2020; sorbelli et al., 2023). isolated dental remains of large-sized suids, which are generally referred to s. strozzii, are known from several middle villafranchian sites, including saint vallier, valdeganga ii, coste san giacomo, quercia, and vigna nuova, among others, and the locality of senèze yielded an almost complete skeleton (schaub, 1943; mein et al., 1978; azzaroli et al., 1988; faure, 2004; cherin et al., 2018; iannucci et al., 2020; azzarà et al., 2022; iannucci, 2023). remains of l. etruscus are also known from senèze (masini, 1989; cherin et al., 2019). moreover, the iannucci a. et al. debate surrounding the taxonomy and evolutionary relationships of middle and late villafranchian leptobos spp., the presence of chronologically overlapping different lineages, and the possible appearance per-evolution (rather than per-dispersal) of the species in europe, clearly push to exercise caution in biochronological correlations (cherin et al., 2019; sorbelli et al., 2023). objective difficulties in the attribution of isolated remains and disagreement on the taxonomy also complicate identifying and resolving the timing of specieslevel event of eucladoceros spp. and ‘pseudodama’ spp. between the middle and late villafranchian, as reflected by the many samples left in open taxonomy (e.g., bellucci et al., 2014; pandolfi & petronio, 2015; azzarà et al., 2022). apart from evolutionary changes in the aforementioned cervid lineages, azzaroli et al. (1988) also mentioned the extinctions of nyctereutes and gazella. both are still considered typical middle (or even early) middle villafranchian taxa, but at least gazella is present in some faunas that could be regarded as late villafranchian or as transitional between the middle and the late villafranchian (e.g., fonelas p-1 and gerakarou 1, see section 5). the arrival of the caprinae procamptoceras brivatense was listed among the bioevents characterizing the late villafranchian turnover by gliozzi et al. (1997), based on its occurrence at olivola (azzaroli, 1950), but the species is already present in senèze and tentatively listed in older faunas (heintz et al., 1974; palombo & valli, 2004). in general, the record of p. brivatense is arguably too patchy to be stressed in a biochronological context, although this might change with further discoveries. the arrival of panthera gombaszoegensis was added by azzaroli et al. (1988) among the bioevents characterizing the wolf event. the first appearance of the species in the italian fossil record is still in the olivola fu (ficcarelli & torre, 1968; gliozzi et al., 1997; palombo, 2009). the locality of gerakarou 1 also yielded remains of the species (koufos, 1992, 2014). the occurrence of the species at la puebla de valverde, calibrated between feni and olduvai subchrons at ~2.12–1.92 ma and generally considered close in age to but more progressive than saint vallier (sinusía et al., 2004; cuccu et al., 2023), was listed by madurell-malapeira et al. (2014), but not reported by kurtén & crusafont-pairó (1977) and cuccu et al. (2023). when azzaroli (1983) discussed the wolf event, c. etruscus was the only modern canid whose arrival was correlated with the olivola fu, while the first appearance of canis arnensis and canis falconeri was placed in the following tasso fu. both species are now already documented in middle villafranchian faunas of western europe. recently, bartolini lucenti & spassov (2022) substantially extended the chronological range of the wild dog canis (xenocyon) falconeri, referring to this taxon a mandible from roca-neyra (~2.6 ma), which suggests a patchy distribution of the species in europe since the beginning of the middle villafranchian. the earliest record of c. arnensis known to date is from senèze, based on the available dating for the site and the generally accepted synonymy between c. arnensis and c. senezensis (brugal & boudadi-maligne, 2011; bartolini lucenti & rook, 2016). several early occurrences of canis sp. listed previously (see section 2) might also belong to species other than c. etruscus (fig. 2a). 5. the “pachycrocuta brevirostris event” and the beginning of the late villafranchian the term “pachycrocuta brevirostris event” or similar expressions have been sporadically used since the 1990s, e.g., by masini & torre (1990; “pliohyaena brevirostris event”), torre et al. (1992; “pachycrocuta brevirostris dispersal event”), palombo et al. (2008; “pachycrocuta event”), but it is only with the work of martínez-navarro (2010) that this concept acquired the meaning of a replacement term for azzaroli’s wolf event. as mentioned in section 2, the evidence of middle villafranchian remains of modern canids alone did not push other researchers to abandon the use of the wolf event earlier, mainly emphasizing the increase in abundance of wolf-like canids, rather than their first appearance in the european fossil record (azzaroli et al., 1988; rook & torre, 1996). sardella & palombo (2007) reviewed the concept of the wolf event and analyzed carnivoran faunas of western europe around the old pliocene-pleistocene boundary (aguirre & pasini, 1985; see pillans, 2004 and clague, 2006), i.e., prior to the provisions adopted in 2009, following which the base of the pleistocene epoch/series was placed at ~2.6 ma (gibbard & head, 2010; gibbard et al., 2010; head & gibbard, 2015). sardella & palombo (2007) argued that, considering the carnivorans, the wolf event includes several diachronic bioevents, such as the dispersals of different canids, panthera, and pachycrocuta. the latter, involving the giant hyena pachycrocuta brevirostris, was regarded as the most representative dispersion in europe. according to iannucci et al. (2021b), the earliest calibrated occurrence of p. brevirostris is likely from fonelas p-1, placed between feni and olduvai subchrons, hence between ~2.12 and 1.92 ma (arribas et al., 2009). some uncertainty persists, however, considering that the taxonomic identification is based on few elements of the deciduous dentition (arribas & garrido, 2008), with only one tooth actually exceeding the biometric range known for pliocrocuta perrieri, a species also present in the site (iannucci et al., 2021b). like fonelas p-1, the fauna of gerakarou 1 is either referred to as middle or late villafranchian (or as transitional), especially due to the cooccurrence of p. brevirostris and gazella (koufos, 1992; konidaris et al., 2021). in italy, gazella is not recorded after the coste san giacomo fu (masini et al., 2013; bellucci & sardella, 2015) and indeed its disappearance was listed among the bioevents characterizing the late villafranchian faunal turnover (azzaroli et al., 1988; gliozzi et al., 1997). in france, it could have become locally extinct even earlier, as it is already absent in senèze and other faunas usually considered of similar age (heintz et al., 1974; palombo & valli, 2004). assuming that this absence is not due to the paucity of the fossil record and/or biased by the environmental preferences of gazella, the association of 81 “wolf event” and large mammal dispersal 82 gazella and p. brevirostris suggests an age intermediate between coste san giacomo and olivola fus. this implies a certain degree of subjectivity in referring faunas in which such association is documented, like fonelas p-1 and gerakarou 1, as to middle or late villafranchian. we argue that these faunas could simply be considered transitional between biochronological units traditionally recognized (arribas et al., 2009; konidaris et al., 2021). this is probably the best choice to minimize inconsistency in current research and with previous studies. the fauna of olivola includes p. brevirostris (ficcarelli & torre, 1970) but it is not directly dated. paleomagnetic investigations carried out at poggio rosso, allowed to correlate this latter locality within the olduvai subchron at ~1.92–1.77 ma (napoleone et al., 2001, 2003; mazza et al., 2004). the fauna of poggio rosso has been considered transitional between olivola and tasso fus (gliozzi et al., 1997), or in other terms it cannot be unequivocally ascribed to one of the two fus, but in any case provides indirect constraints for both. the giant hyena p. brevirostris is documented by direct skeletal evidence in ~60 localities across europe (iannucci et al., 2021b), a number that would likely increase taking into account indirect evidence (e.g., coprolites, gnawing marks) and reports in open taxonomy. actually, roughly coeval early occurrences are known from both sides of eurasia at ~2.0 ma (arribas et al., 2009; liu et al., 2021; iannucci et al., 2021b). the giant hyena is a species that played an important role as a taphonomic agent and has been the subject of much research focused on investigating its potential relationships with other carnivorans and early hominins dispersing out of africa (turner & antón, 1996; palmqvist et al., 2011; espigares et al., 2013; madurell-malapeira et al., 2017; iannucci et al., 2021b). this explains why p. brevirostris has been considered a representative species of the late villafranchian faunal turnover (palombo & sardella, 2007; martínez-navarro, 2010). the earliest material referred to pachycrocuta sp. is from the pliocene of east africa, but african remains of pleistocene age are only known from the south of the continent, possibly indicating that pachycrocuta did not survive long in east africa (werdelin, 1999; werdelin & lewis, 2008). pachycrocuta brevirostris is thought to derive from a large-sized population of pliocrocuta perrifig. 3 selected biochronological schemes and mammal ranges proposed over the years (a) and the updated scheme adopted in this work (b). saint vallier has often been placed in italics to emphasize that it is not an italian site. silhouettes modified from: iurino et al. (2022; canis etruscus); iannucci et al. (2021, pachycrocuta brevirostris); phylopic, by zimices (phylopic.org/image/c2d68ebb-50ec-45f48cd1-6cf52ad02286, hippopotamus). iannucci a. et al. eri, most likely in asia, where transitional samples are known (qiu et al., 2004; iannucci et al., 2021b). in western eurasia, remains assigned to pachycrocuta brevirostris and pliocrocuta perrieri are jointly known from fonelas p-1, gerakarou 1, and dmanisi (collectively ~2.1–1.8 ma; koufos, 1992, 2014; vekua, 1995; lordkipanidze et al., 2007; arribas et al., 2009; iannucci et al., 2021b). the two species share an overall similar morphology in many respects and, especially dealing with isolated remains, attributions often relied on biometric comparisons. as the often-evoked “giant” size of p. brevirostris suggests, this approach is generally accepted, but considering the close relationship between the two species and the many implications associated to the appearance of p. brevirostris, it should be accompanied by some reflection (see iannucci et al., 2022b, for discussion). 6. discussion and conclusions azzaroli (1983) named “wolf event” the faunal turnover associated to the beginning of the late villafranchian, coinciding with the olivola fu. this was also roughly coincident with the old (i.e., prior to 2009) plio-pleistocene boundary at ~1.8 ma. initially, this event was considered to document the first appearance in the european fossil record of canis etruscus (the “wolf”, hence the name) and other large mammals (leptobos etruscus, sus strozzii, and pachycrocuta brevirostris), but soon modified to include the “massive expansion” of the considered species and other bioevents (azzaroli et al., 1988, p. 84). the latter adjustment was a good compromise between the need not to disregard occurrences of the considered species potentially older than olivola (but at the time of doubtful chronology or taxonomic attribution, like those from senèze), and the intention of maintaining the reference role of the olivola fu. however, this definition left room for different interpretations. it is now clear that several bioevents traditionally included in the wolf event and others that have been considered to occur later are conversely already documented in middle villafranchian faunas, most notably the arrival in europe of modern canids, but also of s. strozzii and hippopotamus, among others (fig. 3). if a single species has to be taken as representative of the late villafranchian faunal turnover, the best candidate based on the current evidence is the giant hyena pachycrocuta brevirostris (sardella & palombo, 2007; palombo et al., 2008; martínez-navarro, 2010; iannucci et al., 2021b). pachycrocuta brevirostris is indeed the only species among those initially listed by azzaroli (1983) as part of the wolf event whose first appearance in the european fossil record is still coincident with the beginning of the late villafranchian at the olivola fu, and its occurrences are abundant across eurasia. the first appearance in the european fossil record of panthera gombaszoegensis (added in the wolf event as an accompanying species by azzaroli et al., 1988), is also documented at that time. however, the faunas fonelas p-1 (spain) and gerakarou 1 (greece) contains pachycrocuta brevirostris in association with gazella, a “typical” middle villafranchian taxon (actually a holdover of even older faunas) that is not documented in italy after the coste san giacomo fu (last fu of the middle villafranchian, older than olivola) (bellucci & sardella, 2015). gerakarou 1 includes also panthera gombaszoegensis. therefore, even the arrival of pachycrocuta brevirostris and panthera gombaszoegensis somewhat anticipates the chronology previously assumed. moreover, the beginning of the late villafranchian does not correspond to a sharp faunal turnover as traditionally envisioned for the wolf event. current evidence highlights the rather diachronic nature of large mammal dispersal occurred in the late middle and early late villafranchian (late gelasian, ~2.2–1.8 ma). in this regard, it would be arguably better avoiding naming this time-averaged phenomenon after a single species. here, we dedicated space to discuss the “hippo event” (section 3), as we think that this case eloquently speaks for the need of critically evaluating the biochronological, paleoecological, and paleobiogeographical significance of each bioevent. indeed, the presence of hippopotamus in europe is now attested since ~2.2 ma, documenting an african dispersal of a species linked to humid conditions in a context that is generally deemed to denote the spread of open-adapted faunal elements of mainly asian affinities. however, this bioevent was once considered younger than ~1.8 ma and placed in the tasso fu (azzaroli, 1983; gliozzi et al., 1997). consequently, the presence of hippopotamus at coste san giacomo and senèze was perceived at odds with a middle villafranchian age and engendered ideas of mixing with substantially younger faunas, which are, however, not supported by available dating and field evidence (delson et al., 2006; bellucci et al., 2014; palombo et al., 2017; paquette et al., 2021). several other faunas have been considered mixed or younger than they really are due to the presence of hippopotamus, including, for instance, castel san pietro, bocchignano, and to some extent monte riccio (e.g., marra et al., 2018). it might be argued that since the arrival of many species once considered to indicate the beginning of the late villafranchian is now recognized to be older, then the passage between the middle and late villafranchian could be moved back as well. however, such an approach would be inconsistent with a huge body of previous research in which the beginning of the late villafranchian is typified by the olivola fu, and hence it would be unavoidably ambiguous. moreover, while it is true that the arrivals of many species traditionally included in the wolf event are now already recorded in middle villafranchian faunas, their “massive expansion” (sensu azzaroli et al., 1988) can still be correlated with the olivola fu. this is the case of leptobos etruscus, sus strozzii, and not least canis etruscus. we argue that the earliest occurrence of pachycrocuta brevirostris and panthera gombaszeogensis heralds the late villafranchian faunal turnover, which is then best expressed by the increase in the documentation of the other species. to minimize inconsistent approaches, “transitional” faunas like fonelas p-1 and gerakarou 1 could be simply referred to as such. in general, resolving the exact timing of large mammal bioevents in the late gelasian is complicated by the paucity of middle villafranchian localities, as already 83 “wolf event” and large mammal dispersal 84 pointed out by azzaroli (1983). moreover, of the two most important large mammal middle villafranchian faunas postdating the montopoli fu listed in the synthesis of gliozzi et al. (1997), namely those of collepardo and coste san giacomo, only the correlation of the latter has been confirmed (bellucci et al., 2012, 2014; bona et al., 2015). conversely, although the fauna of collepardo was initially considered close in age to saint vallier (gliozzi et al., 1997), it is now recognized as markedly older than the french site and referred to the triversa fu (early villafranchian; bellucci et al., 2019; iannucci et al., 2022a). on the other hand, a huge number of localities, more or less abundant in terms of fossil remains, including mainly either sporadic (i.e., not coming from systematic excavations) and/or historical findings, have yielded early pleistocene large mammal faunas. as shown by the recent case of vigna nuova (azzarà et al., 2022), proper examinations of these samples might reveal further middle villafranchian faunas simply not recognized as such. acknowledgements we are thankful to d.a. iurino and f. strani for discussion and support. comments and suggestions received during the revision of this manuscript from the reviewers were appreciated. this work was funded by sapienza university of rome grandi scavi 2021 (grant no: sa12117a87bc3f0a) and grandi scavi 2022 (grant no: sa1221816893e2ab) to rs; sapienza university of rome “progetti per avvio alla ricerca tipo 1 anno 2020” (grant no: ar120172b7d44b9e) to ai; sapienza university of rome “progetti per avvio alla ricerca tipo 2 anno 2022” (grant no: ar222181333c1b88) and “contributi premiali per i ricercatori e assegnisti di ricerca per rafforzarne la condizione professionale e potenziare il sistema della ricerca del lazio” call proposal of the lazio region (de g05411, 05/05/2022) to bm. references aguirre e., pasini g. (1985) the pliocene-pleistocence boundary. episodes, 8(2), 116-120. adams n.f., candy i., schreve d.c. (2022) an early pleistocene hippopotamus from westbury cave, somerset, england: support for a previously unrecognized temperate interval in the british quaternary record. journal of quaternary science, 37 (1), 28-41. argant a. (2004) les carnivores du gisement pliocène final de saint-vallier (drôme, france). geobios, 37, s133-s182. arribas a., garrido g. (2008) hiénidos [pachycrocuta brevirostris (aymard, 1846) y hyaena brunnea thunberg,1820] del yacimiento de fonelas p-1 (cuenca de guadix, granada). in: vertebrados del plioceno superior terminal en el suroeste de europa: fonelas p-1 y el proyecto fonelas (ed. by arribas a.), instituto geológico y minero de españa, serie cuadernos del museo geominero 10, madrid, 201-230. athanassiou a. (2022) the fossil record of continental hippopotamids (mammalia: artiodactyla: hippopotamidae) in greece. in: fossil vertebrates of greece 2 (ed. by vlachos e.), springer, cham, 281-289. azzarà b., breda m., cirilli o., madurell-malapeira j., ruzza f., sorbelli l., tancredi d., cherin m. (2022) vigna nuova: the first middle villafranchian mammal assemblage from the valdichiana basin, perugia (italy). bollettino della società paleontologica italiana, 61(2), 223-247. azzaroli a. (1950) osservazioni sulla formazione villafranchiana di olivola in val di magra. atti della società toscana di scienze naturali, memorie serie a, 57, 104-111. azzaroli a. (1970) villafranchian correlations based on large mammals. giornale di geologia, 35, 111131. azzaroli a. (1977) the villafranchian stage in italy and the plio-pleistocene boundary. giornale di geologia, 41, 61-79. azzaroli a. (1983) quaternary mammals and the “endvillafranchian” dispersal event a turning point in the history of eurasia. palaeogeography, palaeoclimatology, palaeoecology, 44, 117-139. azzaroli a. (1995) the “elephant-equus” and the “endvillafranchian” events in eurasia. in: palaeoclimate and evolution with emphasis on human origins (ed. by vrba e.s., denton g.h., patridge t.c., burckle l.h.), yale university press, london, 311318. azzaroli a., de giuli c., ficcarelli g., torre d. (1988) late pliocene to early mid-pleistocene mammals in eurasia: faunal succession and dispersal events. palaeogeography, palaeoclimatology, palaeoecology, 66(1-2), 77-100. bartolini lucenti s., rook l. (2016) a review on the late villafranchian medium-sized canid canis arnensis based on the evidence from poggio rosso (tuscany, italy). quaternary science reviews, 151, 58-71. bartolini lucenti s., spassov n. (2022) cave canem! the earliest canis (xenocyon) (canidae, mammalia) of europe: taxonomic affinities and paleoecology of the fossil wild dogs. quaternary science reviews, 276, 107315. bellucci l., sardella r. (2015) the last antilopini bovids from the early pleistocene of italy. quaternary international, 357, 245-252. bellucci l., mazzini i., scardia g., bruni l., parenti f., segre a.g., segre naldini e., sardella r. (2012) the site of coste san giacomo (early pleistocene, central italy): palaeoenvironmental analysis and biochronological overview. quaternary international, 267, 30-39. bellucci l., bona f., corrado p., magri d., mazzini i., parenti f., scardia g., sardella r. (2014) evidence of late gelasian dispersal of africanfauna at coste san giacomo (anagni basin, central italy): early pleistocene environments and the background of early human occupationin europe. quaternary science reviews, 96, 72-85. bellucci l., biddittu i., brilli m., conti j., germani m., giustini f., iurino d.a., mazzini i., sardella r. (2019) first occurrence of the short-faced bear iannucci a. et al. agriotherium (ursidae, carnivora) in italy: biochronological and palaeoenvironmental implications. italian journal of geosciences, 138(1), 124135. böhme m., spassov n., majidifard m.r., gärtner a., kirscher u., marks m., dietzel c., uhlig g., el atfy h., begun d.r., winklhofer m. (2021) neogene hyperaridity in arabia drove the directions of mammalian dispersal between africa and eurasia. communications earth and environment 2, 85. bona f., bellucci l., sardella r. (2015) the gelasian (late villanyan-mn17) diversified micromammal assemblage with mimomys pliocaenicus from coste san giacomo (anagni basin, central italy), taxonomy and comparison with selected european sites. hystrix, 26(2), 141-151. bout p. (1960) le villafranchien du velay et du bassin hydrographique moyen et supérior de l'allier. centre national de la recherche scientifique, imprimerie jeanne d'arc, le puy. brugal j.p., boudadi-maligne m. (2011) quaternary small to large canids in europe: taxonomic status and biochronological contribution. quaternary international, 243(1), 171-182. brugal j.p., argant a., boudadi-maligne m., crégutbonnoure e., croitor, r., fernandez p., fourvel j. -b., fosse p., guadelli j.l., labe b., magniez p., uzunidis a. (2020) pleistocene herbivores and carnivores from france: an updated overview of the literature, sites and taxonomy. annales de paléontologie, 106, 102384. caloi l., palombo m.r., petronio c. (1980) resti cranici di hippopotamus antiquus (= h. major) e hippopotamus amphibius conservati nel museo di paleontologia dell'università di roma. geologica romana, 19, 91-119. candy i., rose j., lee j. (2006) a seasonally ‘dry’ interglacial climate in eastern england during the early middle pleistocene: palaeopedological and stable isotopic evidence from pakefield, uk. boreas, 35, 255-265. candy i., coope g.r., lee j.r., parfitt s.a., preece r.c., rose j., schreve d.c. (2010) pronounced warmth during early middle pleistocene interglacials: investigating the mid-brunhes event in the british terrestrial sequence. earth-science reviews, 103(3-4), 183-196. capraro l., maiorano p. (2023) italian gssps of the quaternary system. alpine and mediterranean quaternary, 36(1). doi: 10.26382/amq.2023.02 cassoli p.f., segre naldini e. (1984) nuovo contributo alla conoscenza delle faune villafranchiane e del pleistocene medio del bacino di anagni (frosinone). in: atti della xxiv riunione scientifica dell’istituto italiano di preistoria e protostoria, firenze, 115-118. cherin m., bertè d.f., sardella r., rook l. (2013) canis etruscus (canidae, mammalia) and its role in the faunal assemblage from pantalla (perugia, central italy): comparison with the late villafranchian large carnivore guild of italy. bollettino della società paleontologica italiana, 52, 11-18. cherin m., bertè d.f., rook l., sardella r. (2014) redefining canis etruscus (canidae, mammalia): a new look into the evolutionary history of early pleistocene dogs resulting from the outstanding fossil record from pantalla (italy). journal of mammalian evolution, 21, 95-110. cherin m., sorbelli l., crotti m., iurino d.a., sardella r., souron a. (2018) new material of sus strozzii (suidae, mammalia) from the early pleistocene of italy and a phylogenetic analysis of suines. quaternary science reviews, 194, 94-115. cherin m., d’allestro v., masini f. (2019) new bovid remains from the early pleistocene of umbria (italy) and a reappraisal of leptobos merlai. journal of mammalian evolution, 26, 201-224. cherin m., breda m., esattore b., hart v., turek j., porciello f., angeli g., holpin s., iurino d.a. (2022) a pleistocene fight club revealed by the palaeobiological study of the dama-like deer record from pantalla (italy). scientific reports, 12(1), 13898. clague j. (2006) status of the quaternary: your opinion sought. quaternary international, 144, 99-100. croitor r., brugal j.p. (2010) ecological and evolutionary dynamics of the carnivore community in europe during the last 3 million years. quaternary international, 212(2), 98-108. cuccu a., valenciano a., azanza b., demiguel d. (2023) a new lynx mandible from the early pleistocene of spain (la puebla de valverde, teruel) and a taxonomical multivariate approach of medium-sized felids. historical biology, 35(1), 127-138. cuscani politi p. (1966) resti di ippopotami provenienti dalla zona di chiusi. atti dell’accademia dei fisiocritici di siena, 12, 1-44. cuscani politi p. (1971) natura dei sedimenti in cui sono stati rinvenuti i resti di ippopotamo (della zona di chiusi) precedentemente studiati. atti dell’accademia dei fisiocritici di siena, 14, 1-13. delson e., faure m., guérin c., aprile l., argant j., blackwell b.a.b., debard e., harcourt-smith w., martin-suarez, e., monguillon a., parenti f., pastre j.-f., sen s., skinner a.r., swisher c.c., valli a.m.f. (2006) franco-american renewed research at the late villafranchian locality of senèze (haute-loire, france). courier forschungsinstitut senckenberg, 256, 275-290. ehlers j., gibbard p.l. (2007) the extent and chronology of cenozoic global glaciation. quaternary international, 164-165, 6-20. espigares m.p., martínez-navarro b., palmqvist p., ros -montoya s., toro i., agustí j., sala r. (2013) homo vs. pachycrocuta: earliest evidence of competition for an elephant carcass between scavengers at fuente nueva-3 (orce, spain). quaternary international, 295, 113-125. etourneau j., schneider r., blanz t., martinez p. (2010) intensification of the walker and hadley atmospheric circulations during the pliocene-pleistocene climate transition. earth and planetary science letters, 297(1-2), 103-110. faure m. (1985) les hippopotames quaternaires noninsulaires d’europe occidentale. nouvelles ar 85 “wolf event” and large mammal dispersal chives du muséum d’histoire naturelle de lyon, 23, 13-79. faure m. (2004) le sus strozzii du pliocène final de saint-vallier (drôme). geobios, 37, s189-s190. ficcarelli g., torre d. (1968) upper villafranchian panthers of tuscany. palaeontographia italica, 34, 173-184. ficcarelli g., torre d. (1970) remarks on the taxonomy of hyaenids. paleontographia italica, 36, 1333. fidalgo d., galli e., madurell-malapeira j., rosas a. (2021) earliest pleistocene european hippos: a review. comunicações geológicas, 108, 69-73. flesche kleiven h., jansen e., fronval t., smith t.m. (2002) intensification of northern hemisphere glaciations in the circum atlantic region (3.5-2.4 ma)-ice-rafted detritus evidence. palaeogeography, palaeoclimatology, palaeoecology, 184(3-4), 213-223. florindo f., marra f., angelucci d.e., biddittu i., bruni l., florindo f., gaeta m., guillou h., jicha b., macrì p., morigi c., nomade s., parenti f., pereira a., grimaldi s. (2021) environmental evolution, faunal and human occupation since 2 ma in the anagni basin, central italy. scientific reports, 11, 7056. fondi r. (1972) fauna cromeriana della montagnola senese. palaeontographia italica, 68, 1-27. gibbard p.l., smith a.g., zalasiewicz j.a., barry t.l., cantrill d., coe a.l., cope j.c.w., gale a.s., gregory f.j., powell j.h., rawson p.f., stone p., waters c.n. (2005) what status for the quaternary? boreas, 34, 1-6. gibbard p.l., head m.j. (2010) the newly-ratified definition of the quaternary system/period and redefinition of the pleistocene series/epoch, and comparison of proposals advanced prior to formal ratification. episodes, 33, 152158. gibbard p.l., head m.j., walker m. (2010) subcommission on quaternary stratigraphy. formal ratification of the quaternary system/period and the pleistocene series/epoch with a base at 2.58 ma. journal of quaternary science, 25, 96102. gibbard p.l., head m.j. (2020) the quaternary period. in: geologic time scale 2020 (ed. by gradstein f.m., ogg j.g., schmitz m.d., ogg g.m.), elsevier, amsterdam,1217-1255. girotti o., capasso barbato l., esu d., gliozzi e., kotsakis t., martinetto e., petronio c., sardella r., squazzini e. (2003) the section of torre picchio (terni, umbria, central italy): a villafranchian site rich in mammals, molluscs, ostracods and plants. rivista italiana di paleontologia e stratigrafia, 109, 77-98. gliozzi e., abbazzi l., argenti p., azzaroli a., caloi l., capasso barbato l., di stefano g., esu d., ficcarelli g., girotti o., kotsakis t., masini f., mazza p., mezzabotta c., palombo m.r., petronio c., rook l., sala b., sardella r., zanalda e., torre d. (1997) biochronology of selected mammals, molluscs and ostracods from the middle pliocene to the late pleistocene in italy. the state of the art. riv. ital. paleontol. stratigr., 1997, 103, 369-388. gradstein f.m., agterberg f.p., brower j.c., schwarzacher w. (1985) quantitative stratigraphy. reidel publication company and unesco, dordrecht and paris. guérin c. (2005) préface. in: les grands mammifères fossils du velay. les collections paléontologiques du plio-pléistocène du mesée crozatier, le puy-en -velay (ed. by lacombat f.), phil’ print, yssingeaux, 11-13. guérin c., faure m., argant a., argant j., crégutbonnoure é., debard é., delson e., eisenmann v., hugueney m., limondin-lozouet n., martínsuárez e., mein p., mourer-chauviré, parenti f., pastre j.-f., sen s., valli a. (2004) le gisement pliocène supérieur de saint-vallier (drôme, france): synthèse biostratigraphique et paléoécologique. geobios, 37, s349-s360. head m.j., gibbard p.l. (2015) formal subdivision of the quaternary system/period: past, present, and future. quaternary international, 383, 4-35. heintz e., guérin c., martin r., prat f. (1974) principaux gisements villafranchiens de france: listes fauniques et biostratigraphie. mémoires du bureau de recherches géologiques et minières, 78(1), 169-182. iannucci a. (2023) sus strozzii (suidae, mammalia) from the historical locality of quercia (early pleistocene, italy). geobios, 77. doi: 10.1016/j.geobios.2023.03.001 iannucci a., sardella r. (2023) what does the “elephant-equus” event mean today ? reflections on mammal dispersal events around the pliocenepleistocene boundary and the flexible ambiguity of biochronology. quaternary, 6(1), 16. iannucci a., gasparik m., sardella r. (2020) first report of sus strozzii (suidae, mammalia) from the early pleistocene of hungary (dunaalmás) and species distinction based on deciduous teeth. the science of nature, 107(1), 5. iannucci a., cherin m., sorbelli l., sardella r. (2021a) suidae transition at the miocene-pliocene boundary: a reassessment of the taxonomy and chronology of propotamochoerus provincialis. journal of mammalian evolution, 28(2), 323-335. iannucci a., mecozzi b., sardella r., iurino d.a. (2021b) the extinction of the giant hyena pachycrocuta brevirostris and a reappraisal of the epivillafranchian and galerian hyaenidae in europe: faunal turnover during the early–middle pleistocene transition. quaternary science reviews, 272, 107240. iannucci a., bellucci l., conti j., mazzini i., mecozzi b., sardella r., iurino d.a. (2022a) neurocranial anatomy of sus arvernensis (suidae, mammalia) from collepardo (early villafranchian; central italy): taxonomic and biochronological implications. historical biology, 34(1), 108-120. iannucci a., cherin m., sardella r. (2022b). the lost hyena from paciano (umbria, italy) reconsidered. alpine and mediterranean quaternary, 35(2), 105117. iurino d.a., mecozzi b., iannucci a., moscarella a., strani f., bona f., gaeta m., sardella r. (2022) a middle pleistocene wolf from central italy pro 86 iannucci a. et al. vides insights on the first occurrence of canis lupus in europe. scientific reports, 12(1), 2882. jung j. (1946) géologie de l’auvergne et de ses confins bourbonnais et limousins. collection mémoires pour servir à l‘explication de la carte géologique détaillée de la france. imprimerie nationale, paris. kahlke r.-d. (1989) die unterpleistozänen hippopotamus-reste von würzburg-schalksberg. quartär, 39, 67-94. kahlke r.‐d. (2001) schädelreste von hippopotamus aus dem unterpleistozän von untermassfeld. in: das pleistozän von untermaßfeld bei meiningen (thüringen), teil 2 (ed. by kahlke r.‐d.), habelt verlag, bonn, 483-500. kahlke r.-d., garcía n., kostopoulos d.s., lacombat f., lister a.m., mazza p.p., spassov n., titov v.v. (2011) western palaearctic palaeoenvironmental conditions during the early and early middle pleistocene inferred from large mammal communities, and implications for hominin dispersal in europe. quaternary science reviews, 30(11-12), 13681395. konidaris g.e., kostopoulos d.s., maron m., schaller m., ehlers t.a., aidona e., marini m., tourloukis v., muttoni g., koufos g.d., harvati k. (2021) dating of the lower pleistocene vertebrate site of tsiotra vryssi (mygdonia basin, greece): biochronology, magnetostratigraphy, and cosmogenic radionuclides. quaternary, 4, 1. kotsakis t. (1988) biostratigraphy of plio-pleistocene arvicolids (rodents) of italy. modern geology, 13, 163-175. koufos g.d. (1992) the pleistocene carnivores of the mygdonia basin (macedonia, greece). annales de paléontologie, 78, 205-257. koufos g.d. (2014) the villafranchian carnivoran guild of greece: implications for the fauna, biochronology and paleoecology. integrative zoology, 9(4), 444-460. kurtén b., crusafont pairó m. (1977) villafranchian carnivores (mammalia) from la puebla de valverde (teruel, spain). commentationes biologicae, 85, 1-39. lacombat f., abbazzi l., ferretti m.p., martíneznavarro b., moullé p.-e., palombo m.r., rook l., turner a., valli a.-m.f. (2008) new data on the early villafranchian fauna from vialette (hauteloire, france) based on the collection of the crozatier museum (le puy-en-velay, haute-loire, france). quaternary international, 179(1), 64-71. leonardi p. (1947) l’ippopotamo del valdarno. palaeontographia italica, 43, 17-44. lindsay e. (2003) chronostratigraphy, biochronology, datum events, land mammal ages, stage of evolution, and appearance event ordination. bulletin of the american museum of natural history, 279, 212-230. liu j., liu j., zhang h., wagner j., jiangzuo q., song y., liu s., wang y., jin c. (2021) the giant short -faced hyena pachycrocuta brevirostris (mammalia, carnivora, hyaenidae) from northeast asia: a reinterpretation of subspecies differentiation and intercontinental dispersal. quaternary international 577, 29-51. lordkipanidze d., jashashvili t., vekua a., de léon m.s.p., zollikofer c.p., rightmire g.p., pontzer h., ferring r., oms o., tappen m., bukhsianidze m., agustí j., kahlke r., kiladze g., martínez-navarro b., mouskhelishvili a., nioradze m., rook l. (2007) postcranial evidence from early homo from dmanisi, georgia. nature, 449, 305-310. lydekker r. (1885) catalogue of the fossil mammalia in the british museum (natural history) cromwell road, s.w. part i. containing the orders primates, chiroptera, insectivora, carnivora, and rodentia. taylor and francis, london. madurell-malapeira j., ros-montoya s., espigares m.p., alba d.m., aurell-garrido j. (2014) villafranchian large mammals from the iberian peninsula: paleobiogeography, paleoecology and dispersal events. journal of iberian geology, 40(1),167-178. madurell-malapeira j., alba d.m., espigares m.p., vinuesa v., palmqvist p., martínez-navarro b., moyà-solà s. (2017) were large carnivorans and great climatic shifts limiting factors for hominin dispersals? evidence of the activity of pachycrocuta brevirostris during the mid-pleistocene revolution in the vallparadís section (vallès-penedès basin, iberian peninsula). quaternary international, 431, 42-52. marciszak a., kropczyk a., gornig w., kot m., nadachowski a., lipecki g. (2023) history of polish canidae (carnivora, mammalia) and their biochronological implications on the eurasian background. genes, 14(3), 539. marra f., petronio c., salari l., florindo f., giaccio b., sottili g. (2018) a review of the villafranchian fossiliferous sites of latium in the framework of the geodynamic setting and paleogeographic evolution of the tyrrhenian sea margin of central italy. quaternary science reviews, 191, 299-317. martin r. (1973) trois nouvelles espèces de caninae (canidae, carnivora) des gisements pliovillafranchiens d'europe. travaux et documents des laboratoires de géologie de lyon, 57(1), 8796. martínez-navarro b. (2004) hippos, pigs, bovids, saber -toothed tigers, monkeys, and hominids, dispersals through the levantine corridor during late pliocene and early pleistocene times. in: human paleoecology in the levantine corridor (ed. by goren-inbar n., speth j.d.), oxbow books, oxford, 37-52. martínez-navarro, b. (2010) early pleistocene faunas and hominin dispersals. in: out of africa i: the first colonization of eurasia (ed. by fleagle j.g., shea j.j., grine f.e., baden a.l., leakey r.e.), vertebrate paleobiology and paleoanthropology. springer netherlands, dordrecht, 207-224. martínez-navarro b., madurell-malapeira j., rosmontoya s., espigares m.p., medin t., hortola p., palmqvist p. (2015) the epivillafranchian and the arrival of pigs into europe. quaternary international, 389, 131-138. martino r., pandolfi l. (2022) the quaternary hippopotamus records from italy. historical biology, 34 87 “wolf event” and large mammal dispersal (7), 1146-1156. masini f. (1989) i bovini villafranchiani dell’italia. unpublished phd thesis, università consorziate: modena, bologna, firenze, roma. masini f., torre d. (1990) large mammal dispersal events at the beginning of the late villafranchian. in: european neogene mammal chronology (ed. by lindsay e.h., fahlbusch v., mein p.), plenum press, new york, 131-138. masini f., palombo m.r., rozzi r. (2013) a reappraisal of the early to middle pleistocene italian bovidae. quaternary international, 288, 45-62. maxia c. (1949) resti di mammiferi rinvenuti nella miniera di lignite di san pietro (sabina). la ricerca scientifica, 19, 346-347. mazza p. (1991) interrelations between pleistocene hippopotami of europe and africa. bolletino della società paleontologica italiana, 30(2), 153-186. mazza p. (1995) new evidence on the pleistocene hippopotamuses of western europe. geologica romana, 31, 61-241. mazza p., rustioni m. (1994) the fossil bear from senèze (southern france). rendiconti lincei, 5, 17-26. mazza p.p., bertini a. (2013) were pleistocene hippopotamuses exposed to climate‐driven body size changes? boreas, 42(1), 194-209. mazza p.p., bertini a., magi m. (2004) the late pliocene site of poggio rosso (central italy): taphonomy and paleoenvironment. palaios, 19(3), 227248. mazzini i., paccara p., petronio c., sardella r. (2000) geological evolution and biochronological evidences of the monte riccio section (tarquinia, central italy). rivista italiana di paleontologia e stratigrafia, 106(2), 247-256. mecozzi b., iannucci a., mancini m., sardella r. (2021) redefining ponte molle (rome, central italy): an important locality for middle pleistocene mammal assemblages of europe. alpine and mediterranean quaternary, 34(1), 131-154. mein p., moissenet e., truc g. (1978) les formations continentales du néogène supérieur des vallées du jucar et du cabriel au ne d’albacete (espagne), biostratigraphie et environment. travaux et documents des laboratoires de géologie de lyon, 72, 99-147. meli r. (1882) sulla zona dei fori lasciati dai litodomi pliocenici nella calcaria giurese di fara sabina. bollettino del regio comitato geologico d’italia, 13, 147-155. napoleone g., albanielli a., azzaroli a., mazzini m. (2001) the poggio rosso locality calibrated to the end-pliocene and its significance for dating the late villafranchian mammal faunas of the upper valdarno, central italy. rivista italiana di paleontologia e stratigrafia, 107, 287-296. napoleone g., albianelli a., azzaroli a., bertini a., magi m., mazzini m. (2003) calibration of the upper valdarno basin to the plio-pleistocene for correlating the apennine continental sequences. il quaternario, 16(1 bis), 131-166. nesti f. (1820) descrizione osteologica dell'ippopotamo maggiore fossile dei terreni mobili del valdarno superiore in toscana. atti della società italiana delle scienze, modena, 28, 1-23. nomade s., pastre j.-f., guillou h., faure m., guérin c., delson e., debard e., voinchet p., messager e. (2014) 40ar/39ar constraints on some french landmark late pliocene to early pleistocene large mammalian paleofaunas: paleoenvironmental and paleoecological implications. quaternary geochronology, 21, 2-15. palmqvist p., gröcke d.r., arribas a., fariña r.a. (2003) paleoecological reconstruction of a lower pleistocene large mammal community using biogeochemical (δ13c, δ15n, δ18o, sr: zn) and ecomorphological approaches. paleobiology, 29(2), 205-229. palmqvist p., pérez-claros j.a., janis c.m., figueirido b., torregrosa v., grocke d.r. (2008) biogeochemical and ecomorphological inferences on prey selection and resource partitioning among mammalian carnivores in an early pleistocene community. palaios, 23(11), 724-737. palmqvist p., martínez-navarro b., pérez-claros j.a., torregrosa v., figueirido b., jiménez-arenas j.m., patrocinio espigares m., ros-montoya s., de renzi m. (2011) the giant hyena pachycrocuta brevirostris: modelling the bone-cracking behavior of an extinct carnivore. quaternary international 243, 61-79. palombo m.r. (2009) biochronology of terrestrial mammals and quaternary subdivisions: a case study of large mammals from the italian peninsula. il quaternario, 22, 291-306. palombo m.r., valli a.m.f. (2004) remarks on the biochronology of mammalian faunal complexes from the pliocene to the middle pleistocene in france. geologica romana, 37(2003-2004), 145163. palombo m.r., sardella r. (2007) biochronology versus biostratigraphy: a true dilemma or a false trouble? the example of the plio-pleistocene large mammalian faunas from the italian peninsula. quaternary international, 160, 30-42. palombo m.r., alberdi m.t. (2017) light and shadows in the evolution of south european stenonoid horses. fossil imprint, 73, 115-140. palombo m.r., sardella r., novelli m. (2008) carnivora dispersal in western mediterranean during the last 2.6 ma. quaternary international, 179, 176 -189. palombo m.r., alberdi m.t., bellucci l., sardella r. (2017) an intriguing middle-sized horse from coste san giacomo (anagni basin, central italy). quaternary research, 87(2), 347-362. pandolfi l., petronio c. (2015) a brief review of the occurrences of pleistocene hippopotamus (mammalia, hippopotamidae) in italy. geologia croatica, 68(3), 313-319. pandolfi l., spadi m., martinetto e., kotsakis t., esu d. (2017) new data on the lower pleistocene (gelasian) lignite beds of castel san pietro (rieti, central italy). rivista italiana di paleontologia e stratigrafia, 123(2), 335-346. 88 iannucci a. et al. paquette j.l., médard e., poidevin j.l., barbet p. (2021) precise dating of middle to late villafranchian mammalian paleofaunae from the upper allier river valley (french massif central) using upb geochronology on volcanic zircons. quaternary geochronology, 65, 101198. pastre j.f., debard e., nomade s., guillou h., faure m., guérin c., delson e. (2015) nouvelles données géologiques et téphrochronologiques sur le gisement paléontologique du maar de senèze (pléistocène inférieur, massif central, france). quaternaire. revue de l'association française pour l'étude du quaternaire, 26(3), 225-244. pillans b. (2004) proposal to redefine the quaternary. episodes, 27(2), 127. poidevin j.l., cantagrel j.m., g.u.e.r.p.a. (1984) un site unique du plio-pleistocene en europe: le pluteau de perrier (puy-de-dôme) confrontation des donneés volcanologiques, stratigraphiques et paléontologiques. revue des sciences naturelles d'auvergne, 50, 87-95. psarianos p. (1954) über das vorkommen von hippopotamus auf kephallinia (griechenland). praktiká akademías athinón, 28, 408-412. qiu z., deng t., wang b. (2004) early pleistocene mammalian fauna from longdan, dongxiang, gansu, chian. palaeontologica sinica n. ser. c, 27, 1-198. reimann k.c., strauch f. (2008) ein hippopotamusschädel aus dem pliozän von elis (peloponnes, griechenland). neues jahrbuch für geologie und paläontologie-abhandlungen, 249(2), 203-222. repenning c.a. (1967) nearctic mammalian dispersal in late cenozoic. in: the bering land bridge (ed. by hopkins d.m.), stanford university press, palo alto, 208-311. repenning c.a. (1980) faunal exchanges between siberia and north america. canadian journal of anthropology, 1, 37-44. reumer, j.w.f., piskoulis p. (2017) a specimen of canis cf. c. etruscus (mammalia, carnivora) from the middle villafranchian of the oosterschelde. netherlands journal of geosciences, 96(1), 3-7. rook l., torre d. (1996) the wolf-event in western europe and the beginning of the late villafranchian. neues jahrbuch für geologie und paläontologie-monatshefte, 1996(8), 495-501. rook l., martínez-navarro b. (2010) villafranchian: the long story of a plio-pleistocene european large mammal biochronologic unit. quaternary international, 219, 134-144. rook l., croitor r., delfino m., ferretti m.p., gallai g., pavia m. (2013) the upper valdarno pliopleistocene vertebrate record: an historical overview, with notes on palaeobiology and stratigraphic significance of some important taxa. italian journal of geosciences, 132(1), 104-125. russo ermolli e., sardella r., di maio g., petronio c., santangelo n. (2010) pollen and mammals from the late early pleistocene site of saticula (sant'agata de'goti, benevento, italy). quaternary international, 225(1), 128-137. sardella r. (2012) evidence of hippopotamus remains in the middle villafranchian faunal assemblages of anagni basin (central italy): evidence for an early dispersal of the genus in europe. quaternary international, 279-280, 427. sardella r., palombo m.r. (2007) the pliocenepleistocene boundary: which significance for the so called “wolf event”? evidences from western europe. quaternaire, 18, 65-71. sardella r., bellucci l., bona f., cherin m., iurino d.a., rook l. (2018) before and after the earliest homo dispersal in europe: evidence from the early pleistocene sites of the italian peninsula. comptes rendus palevol, 17(4-5), 287-295. scager d.j., ahrens h.j., dieleman f.e., van den hoek ostende l.w., de vos j., reumer j.w.f. (2017) the kor & bot collection revisited, with a biostratigraphic interpretation of the early pleistocene oosterschelde fauna (oosterschelde estuary, the netherlands). deinsea, 17, 16-31. schaub s. (1943) die oberpliocaene säugetierfauna von senèze (haute-loire) und ihre verbreitungsgeschichtliche stellung. eclogae geologicae helvetiae, 36, 270-289. shackleton n.j. (1995) new data on the evolution of pliocene climatic variability. in: palaeoclimate and evolution with emphasis on human origins (ed. by vrba e.s., denton g.h., patridge t.c., burckle l.h.), yale university press, london, 242-248. sinusía c., pueyo e.l., azanza b., pocoví a. (2004) datación magnetoestratigráfica del yacimiento paleontológico de la puebla de valverde (teruel). geotemas, 6(4), 339-342. sorbelli l., cherin m., kostopoulos d.s., sardella r., mecozzi b., plotnikov v., prat-vericat m., azzarà b., bartolini-lucenti s., madurell-malapeira, j. (2023) earliest bison dispersal in western palearctic: insights from the eobison record from pietrafitta (early pleistocene, central italy). quaternary science reviews, 301, 107923. strani f., demiguel d., sardella r., bellucci l. (2015) paleoenvironments and climatic changes in the italian peninsula during the early pleistocene: evidence from dental wear patterns of the ungulate community of coste san giacomo. quaternary science reviews, 121, 28-35. strani f., demiguel d., sardella r., bellucci l. (2018) resource and niche differentiation mechanisms by sympatric early pleistocene ungulates: the case study of coste san giacomo. quaternary international, 481, 157-163. strani f., bellucci l., iannucci a., iurino d.a., mecozzi b., sardella r. (2022) palaeoenvironments of the mis 15 site of cava di breccia-casal selce 2 (central italian peninsula) and niche occupation of fossil ungulates during middle pleistocene interglacials. historical biology, 34(3), 555-565. symeonidis n.k., theodorou g.e. (1986) new localities with fossil hippopotamus in northwestern peloponnese. annales géologiques des pays helléniques, 33, 51-67. thenius e. (1955) hippopotamus aus dem astien von elis (peloponnes). annales géologiques. des pays helléniques, 6, 206-212. 89 “wolf event” and large mammal dispersal torre d. (1967) i cani villafranchiani della toscana. palaeontographia italica, 63, 113-138. torre d. (1979) the ruscinian and the villafranchian dogs of europe. bollettino della società paleontologica italiana, 18(2), 162-165. torre d., ficcarelli g., masini f., rook l., sala b. (1992) mammal dispersal events in the early pleistocene of western europe. courier forschungsinstitut senckenberg, 153, 51-58. tuccimei g. (1889a) alcune recenti osservazioni sul villafranchiano della sabina bollettino della società geologica italiana, 8, 566-568. tuccimei g. (1889b) il villafranchiano nelle valli sabine e i suoi fossili caratteristici. bollettino della società geologica italiana, 8, 95-131. tuccimei g. (1891) alcuni mammiferi fossili delle provicie umbra e romana. memorie della pontificia accademia dei nuovi lincei, 7, 89-152. tuccimei g. (1893) resti di arvicola nel pliocene lacustre della sabina. memorie della pontificia accademia dei nuovi lincei, 9, 35-45. tuccimei g. (1898) sopra alcuni cervi pliocenici della sabina e della provincia di roma. memorie della pontificia accademia dei nuovi lincei, 14, 33-55 turner a., antón m. (1996) the giant hyaena pachycrocuta brevirostris (mammalia, carnivora, hyaenidae). geobios, 29, 455-468. van der made j. (2005) le pliocène moyen, le villafranchien inférieur. la faune du velay vers 3 millions d’années. cf. “microstonyx” major. in: les grands mammifères fossils du velay. les collections paléontologiques du plio-pléistocène du mesée crozatier, le puy-en-velay (ed. by lacombat f.), phil’ print, yssingeaux, 58-59. van der made j., moullé p.e. (2005) le pliocène moyen, le villafranchien inférieur. la faune du velay vers 3 millions d’années. in: les grands mammifères fossils du velay. les collections paléontologiques du plio-pléistocène du mesée crozatier, le puy-en-velay (ed. by lacombat f.), phil’ print, yssingeaux, 56-57. van der made j., stefaniak k., marciszak a. (2014) the polish fossil record of the wolf canis and the deer alces, capreolus, megaloceros, dama and cervus in an evolutionary perspective. quaternary international, 326, 406-430. van der made j., rosell j., blasco r. (2017) faunas from atapuerca at the early-middle pleistocene limit: the ungulates from level td8 in the context of climatic change. quaternary international, 433, 296-346. vekua a. (1995) die wirbeltierfauna des villafranchium von dmanisi und ihre biostratigraphische bedeutung. jahrbuch des römisch-germanischen zentralmuseums mainz, 42, 77-180. viret j. (1954) le loess à bancs durcis de saint-vallier (drôme) et sa faune de mammifères villafranchiens. nouvelles archives du muséum d’histoire naturelle de lyon, 4, 1-200. werdelin l. (1999) pachycrocuta (hyaenids) from the pliocene of east africa. paläontologische zeitschrift, 73, 157-165. werdelin l., lewis m.e. (2008) new species of crocuta from the early pliocene of kenya, with an overview of early pliocene hyenas of eastern africa. journal of vertebrate paleontology, 28, 11621170. ms. received: february 10, 2023 revised: march 18, 2023 accepted: march 19, 2023 available online: march 29, 2023 90 iannucci a. et al. imp.bentivenga& il movimento gravitativo profondo di craco (basilicata ionica) mario bentivenga1, mauro coltorti2 & giacomo prosser1 1dipartimento di scienze geologiche, università degli studi della basilicata, campus di macchia romana 85100 potenza 2dipartimento di scienze della terra, università degli studi di siena, via laterina, 8 53100 siena riassunto: m. bentivenga, m. coltorti & g. prosser, il movimento gravitativo profondo di craco (basilicata ionica). it issn 0394-3356, 2004. l’abitato di craco (matera) è stato interessato da ripetuti movimenti franosi che hanno destabilizzato in maniera particolare il versante sud-occidentale dalla fine del 1959 sino all’abbandono coatto di gran parte del paese ed al totale trasferimento nell’intervallo di tempo 1965-1980. la dorsale su cui sorge il paese è orientata nw-se ed occupa una delle porzioni più esterne del fronte dell’appennino meridionale. nell’area di craco, delimitata a sud-ovest dal torrente bruscata ed a nord-est dal torrente salandrella, è stato eseguito un rilevamento geologico e geomorfologico di dettaglio che ha permesso di evidenziare i rapporti esistenti tra l’evoluzione del paesaggio lungo un tratto della porzione frontale di una catena recente e le differenti forme di modellamento dei rilievi. i numerosi affioramenti presenti nell’area hanno evidenziato le relazioni esistenti tra unità tettoniche alloctone intensamente deformate e unità argilloso-sabbioso-conglomeratiche appartenenti a differenti cicli deposizionali di età pliocenica, che si sono depositate durante l’avanzamento del fronte della catena (balduzzi et alii, 1982; sella et alii, 1988; pieri et alii, 1997; bentivenga et alii, 2003). dopo il pleistocene medio, l’area è stata interessata da movimenti di sollevamento che hanno condotto alla genesi di depositi marini terrazzati a quote elevate sui fondi vallivi lungo i margini del golfo di taranto (bentivenga et al., 2004). l’interazione tra sollevamento e cambiamenti climatici quaternari ha portato, nel pleistocene medio e superiore, alla deposizione di unità alluvionali terrazzate e, durante l’olocene, ad un importante approfondimento vallivo a cui è seguita una modesta fase aggradazionale. la stesura della carta geomorfologica di dettaglio ha permesso la comprensione dei movimenti gravitativi che hanno influenzato l’assetto morfologico attuale. e’ stato possibile stabilire l’interazione tra le morfosequenze ed i depositi responsabili del modellamento del paesaggio. i versanti della dorsale di craco sono modellati dall’azione dei corsi d’acqua, dall’erosione calanchiva, ma in maniera prevalente da frane, anche di grandi dimensioni, che interessano tutti i terreni affioranti. l’analisi multitemporale ha permesso di verificare l’evoluzione dei movimenti gravitativi negli ultimi 50 anni. in questo lavoro si propone un modello che interpreta le evidenze raccolte nell’ambito della riattivazione di un movimento gravitativo profondo di versante. viene inoltre presentata una metodologia di indagine che utilizza la geologia del quaternario e la geomorfologia nello studio dei grandi movimenti gravitativi che costituiscono uno dei temi tuttora poco investigati del territorio italiano, malgrado la sua rilevanza in termini di pericolosità e rischi geologici. abstract: m. bentivenga, m. coltorti & g. prosser, deep-seated gravitational movements of craco (basilicata ionica). it issn 0394-3356, 2004. the craco ridge (matera, southern italy) experienced repeated landslide movements, particularly along the southwestern slope, starting from the end of the year 1959. the craco village, located at the top of the ridge, was almost completely abandoned between 1965 and 1980 because of protracted landslide activity. the ridge is oriented nw-se and is located at the most external thrust front of the southern apennines. a geological and geomorphological survey has been performed in the area that extends between the salandrella and bruscata creeks. detailed mapping has been used to show the relationships between landscape evolution and the various landforms in the frontal part of a recent mountain belt. furthermore, several exposures document the relationships between strongly deformed tectonic units and the pliocene deposits, composed of clays, sandstones and conglomerates, that sedimented during the late deformational stages of the mountain belt (balduzzi et alii, 1982; sella et alii, 1988; pieri et alii, 1997; bentivenga et alii, 2003). the area underwent generalised uplift since the beginning of middle pleistocene, as shown by the altitude of the terraced deposits of the same age, all around the taranto gulf (bentivenga et al., 2004). interaction between uplift and quaternary climate changes led to the deposition of terraced alluvial units during the late middle-late pleistocene and to the deepening of the valleys that were filled by minor aggradational deposits during the holocene. the detailed geomorphological map is useful to understand the importance of the gravitational movements in shaping the present landscape. a relationship between the morphological sequences and the deposits responsible for the landscape evolution has been defined. the slopes of the craco ridge have been shaped by streams, badland erosional processes, and, more significantly, by huge landslides, that affected all the oucropping lithologies. multitemporal analysis has been used to show the evolution of the gravitational movements during the last 50 years. in this paper we suggest that landslides represent the reactivation of a deep-seated gravitational slope deformation. furthermore, we propose that evidence coming from studies of quaternary geology and geomorphology should be taken into account to analise huge gravitational movements, a relevant topic in risk assessment still poorly investigated in the italian territory. parole chiave: movimento gravitativo profondo, craco, basilicata. keywords: deep-seated gravitational movements, craco, basilicata. il quaternario italian journal of quaternary sciences 17(2/2), 2004, 613-625 introduzione l’area studiata coincide con una dorsale orientata nw-se appena ad ovest del fronte sepolto della catena appenninica (fig. 1 a, b). il paese di craco è stato edificato lungo il crinale dove affiorano i conglomerati pliocenici verticalizzati da retroscorrimenti che hanno portato in affioramento unità alloctone (fig. 1 c). la morfologia dell’intera dorsale risente molto del complesso assetto tettonico. infatti, sono visibili in affioramento le relazioni esistenti tra le unità tettoniche alloctone e le unità argilloso-sabbioso-conglomeratiche poggianti in discordanza angolare sulle precedenti, ed appartenenti a diversi cicli deposizionali pliocenici. 614 m. bentivenga, m. coltorti & g. prosser numerosi sono i movimenti di massa che interessano tutta l’area, ma è evidente il particolare sviluppo che assumono lungo il versante sud-occidentale di craco. questa accentuata franosità risulta essere in stretto rapporto con la presenza di un movimento di grande dimensioni, che può essere riconducibile ad una deformazione gravitativa profonda di versante (dgpv), anche se, come molti dei fenomeni in natura, esistono tutti i termini di transizione tra le grandi frane e le dgpv e queste ultime mancano di criteri univoci di differenziazione. le continue riattivazioni di questo complesso franoso lungo il versante, che da craco degrada verso il torrente bruscata, hanno minacciato da sempre la stabilità dell’abitato fino ad arrivare alla drastica decisione dell’abbandono. il lavoro è finalizzato allo studio del movimento gravitativo profondo che interessa gran parte del versante sud-occidentale della dorsale di craco. gli studi precedenti effettuati nel’area (del prete & petley, 1982) hanno considerato solamente le frane superficiali, senza tener conto della presenza di dgpv. da un’attenta analisi geomorfologia e l’individuazione delle relazioni esistenti tra il versante in movimento ed i depositi fluviali terrazzati e di fondovalle, è stato possibile stabilire la dinamica del versante, la sequenza degli eventi ed il fig. 1 a) schema geologico regionale dell’appennino meridionale; b) schema tettonico della porzione frontale dell’appennino meridionale, comprendente la faglia scorciabuoi ed il bacino di sant’arcangelo (modificato da patacca & scandone, 2001); c) profilo geologico attraverso il fronte dell’appennino meridionale. a) geological sketch map of the southern apennines. b) tectonic sketch map of the frontal part of the apenninic chain (redrawn after patacca & scandone, 2001);c) cross-section of the front of the southern apennines. grado di attività dei movimenti franosi. per lo studio del movimento gravitativo profondo di craco, è stata seguita una metodologia di semplice applicazione, che però talora non viene utilizzata per lo studio di fenomeni analoghi, preferendone altre più costose e spesso peggiorative per l’equilibrio già precario della massa in movimento. un approccio multidisciplinare facilita la determinazione delle dimensioni, della geometria e del grado di attività dei movimenti gravitativi, anche profondi, conoscenze indispensabili per meglio progettare sia l’ubicazione dei sondaggi che la rete di monitoraggio ed eventuali opere di sistemazione. geologia in prossimità del fronte sepolto della catena appenninica meridionale, in particolare appena ad ovest, si eleva la dorsale di craco su cui è stato edificato nel medioevo il paese (fig. 1a, b). nell’area affiorano unità alloctone sovrascorse sui depositi clastici pliopleistocenici dell’avanfossa bradanica e ricoperte a loro volta da conglomerati, sabbie e argille di età pliopleistocenica deformati dal continuo avanzamento del fronte della catena (fig. 1c). le unità alloctone sono sovrascorse, lungo una superficie sub-orizzontale sui depositi plio-pleistocenici dell’avanfossa, a loro volta poggianti direttamente sulla piattaforma apula, ribassata a gradoni da faglie dirette ad alto angolo. per la messa a punto del modello strutturale è stato fondamentale conoscere i dati relativi ai sondaggi eseguiti per l’esplorazione petrolifera nell’area. dai dati in possesso si può asserire che l’avanzamento delle unità alloctone è avvenuto fino al pleistocene medio, visto che a letto delle unità sovrascorse sono stati trovati depositi del pleistocene inferiore (balduzzi et alii, 1982). in particolare, lungo la dorsale di craco le unità alloctone affiorano grazie alla presenza di retroscorrimenti legati alla deformazione del fronte della catena appenninica (figg. 2 3a). dal punto di vista stratigrafico, i terreni alloctoni sono rappresentati dalle argille varicolori (cretaceooligocene), sulle quali poggiano in discordanza depositi pliocenici suddivisi in due cicli separati da una seconda superficie di discordanza. ciò è evidente in alcuni punti del versante nord-orientale della collina di craco ed in particolare in località macinecchie, dove lungo il crinale si può osservare la superficie di discordanza che separa i due cicli deposizionali ed in particolare l’appoggio in onlap dei depositi del secondo ciclo sulla stessa superficie (fig. 3b). il primo ciclo è composto da corpi conglomeratici lenticolari con intercalazioni sabbiose, sabbie bioclastiche (“sabbie inferiori” in fig. 2), argille marnose con orizzonti sabbiosi ed infine sabbie bioclastiche (“sabbie superiori” in fig. 2), con uno spessore complessivo stimato di circa 350 metri, mentre il secondo ciclo è costituito da argille marnose grigie con intercalazioni di sabbie e livelli tufitici di spessore metrico. le strutture tettoniche osservate nell’area di craco sono lateralmente discontinue, come è facilmente riscontrabile dalla carta geologica (fig. 2). la variabilità laterale nella geometria delle strutture è in parte 615il movimento gravitativo profondo ... legata alla presenza di numerose faglie ad orientazione antiappenninica che dislocano le strutture contrazionali. la presenza di queste faglie è stata verificata cartografando in dettaglio i principali orizzonti conglomeratici situati alla base del primo ciclo. inoltre, importanti faglie antiappenniniche sono ben visibili tra la località macinecchie e tempa s. lorenzo. all’interno di questo sistema la faglia principale presenta un’apparente cinematica trascorrente sinistra e rigetta sia le strutture a vergenza normale che quelle retrovergenti di circa un chilometro (fig. 2). nell’area di craco i depositi pliocenici e le argille varicolori formano una monoclinale immergente verso nord-est (fig. 2 e 3a), situata a tetto di un retroscorrimento principale che porta le argille varicolori sulle argille del secondo ciclo. il contatto tettonico, inclinato di circa 60° verso ne, è ben visibile da fosso bruscata, lungo il versante meridionale della collina di craco. a loro volta le argille varicolori sono ricoperte dal conglomerato basale del primo ciclo, che immerge sempre verso nord-est con inclinazioni di circa 60°. oltre che sul versante sinistro di fosso bruscata, le argille varicolori affiorano anche in corrispondenza del versante nord-orientale della collina di craco, in località macinecchie, dove apparentemente sono sovrapposte ai conglomerati ed alle sabbie inferiori. questa situazione anomala può essere spiegata con un secondo retroscorrimento, che porta le argille varicolori sopra le sabbie inferiori o le argille marnose del primo ciclo, come è stato indicato nel profilo geologico di figura 3a. i dati ottenuti dal rilevamento eseguito nell’area di craco permettono di evidenziare i processi che hanno operato nella parte frontale della catena. in particolare si può documentare come la progressiva deformazione delle unità alloctone sia avvenuta contemporaneamente alla sedimentazione dei depositi pliocenici, come è evidenziato dall’appoggio in onlap dei depositi del secondo ciclo su quelli del primo ciclo (fig. 3b). l’evoluzione tettonica dell’area può essere sintetizzata come segue: i) il processo di formazione del mélange (roure et alii, 1991), responsabile della notevole deformazione interna che caratterizza le argille varicolori, è avvenuto prima della deposizione della successione pliocenica. infatti, i depositi del primo ciclo poggiano direttamente sulle argille varicolori già deformate, che costituivano la porzione frontale del prisma di accrezione dell’appennino meridionale; ii) un’intensa attività tettonica ha caratterizzato la fine del primo ciclo causando un basculamento verso nord-est di tutta la successione; iii) la deformazione è proseguita durante il pliocene – pleistocene inferiore con la genesi di sovrascorrimenti e retroscorrimenti che hanno deformato le argille del pliocene sommitale; iiii) a partire dalla fine del pleistocene inferiore inizio del pleistocene medio l’area è interessata da fenomeni di sollevamento (ciaranfi & d’alessandro, in press) che hanno condotto alla genesi di una serie di terrazzi marini lungo tutto il golfo di taranto (bentivenga et alii, 2004 cum bib.). geomorfologia l’analisi geomorfologica ha messo in evidenza la geometria, lo stato di attività dei corpi franosi e le relazioni spazio-temporali esistenti tra di essi. sono stati 616 fi g. 2 c ar ta g eo lo gi ca d el l’a re a d i c ra co . / g eo lo gi ca l m ap o f t he c ra co a re a. m. bentivenga, m. coltorti & g. prosser 617 individuati, inoltre, tutti gli elementi utili ad un’analisi morfo-cronologica in modo da poter stabilire la sequenza degli eventi che hanno condotto all’assetto attuale del territorio (fig. 4 e 5). a tale scopo, particolare attenzione è stata rivolta alle relazioni esistenti tra il movimento gravitativo profondo di versante, la morfologia ed i depositi del fondovalle. la dorsale di craco ha un’orientazione nw-se secondo le direttrici appenniniche ed è delimitata a sud-ovest dal torrente bruscata e a nord-est dal torrente salandrella. il versante nord-orientale della dorsale ha una pendenza media di circa 13° ed è interessato da numerosi movimenti franosi alcuni dei quali si sviluppano lungo tutto il versante fino a raggiungere il fondovalle. sono stati classificati come frane per scivolamento, colate e più spesso movimenti franosi complessi perché si presentano con una zona di distacco ai piedi della quale sono presenti trincee e contropendenze tipiche delle frane per scivolamento rotazionale, mentre verso valle si sviluppano con lobi ed ondulazioni tipiche delle colate (carrara et alii, 1985). le trincee e le contropendenze presentano in fig. 3 a) sezione geologica che illustra le strutture tettoniche più rappresentative dell’area di craco; b) appoggio in onlap dei depositi del secondo ciclo sulla discontinuità che separa i due cicli della successione pliocenica. e’ evidente la terminazione del corpo di sabbie situato alla base del secondo ciclo. a) cross-sections showing the main tectonic and stratigraphic features of the craco area; b) onlap relation of the upper cycle on the bioclastic sands of the first cycle. the lateral termination of the sand level located at the base of the second cycle is shown. il movimento gravitativo profondo ... 618 fi g. 4 c ar ta g eo m or fo lo gi ca d el l’a re a d i c ra co . g eo m or p ho lo gi ca l m ap o f t he c ra co a re a. m. bentivenga, m. coltorti & g. prosser 619 fi g. 5 c ar ta g eo m or fo lo gi ca r ic os tr ui ta d al le fo to a er ee i. g .m ., vo lo d el 1 95 419 55 . g eo m or p ho lo gi ca l m ap o f t he c ra co a re a d ra w n fr om a re al p ho to gr ap hs (i .g .m ., fli gh t of 1 95 419 55 ). il movimento gravitativo profondo ... genere uno sviluppo lineare limitato sia perché sono dissecate dalle incisioni vallive sia perché si presentano obliterate da processi di colluvionamento. la parte bassa del versante orientale presenta scarpate modellate sui sedimenti argillosi, a reggipoggio e con esposizione verso i quadranti meridionali. le scarpate sono interessate da forme calanchive che si sviluppano talora per diverse centinaia di metri come nella parte settentrionale di contrada macinecchia. ai piedi dello stesso versante si sviluppa un’area pianeggiante occupata dall’ampio letto ordinario del torrente salandrella e dei suoi terrazzi olocenici. il versante sud-occidentale della dorsale di craco ha una pendenza media di circa 11° ed è interessato da movimenti franosi con tipologie simili a quelle descritte per il versante nord-orientale pur presentando in genere dimensioni maggiori. molti sono i corpi di frana che si sviluppano lungo tutto il versante interessando i conglomerati che affiorano alla sommità del rilievo, le argille varicolori poste a mezza costa e le argille plioceniche affioranti nella parte bassa. il movimento gravitativo profondo del versante sud-orientale di craco i movimenti gravitativi profondi di versanti occupano una posizione intermedia tra le frane ed i fenomeni tettonici gravitativi (engelen, 1963; goguel, 1978, dramis, 1984; sorriso-valvo, 1984c; cavallin et alii 1987). in prossimità del crinale della dorsale di craco, tra le ultime case e la chiesetta di santa maria stella verso nord-ovest, si segue una lunga trincea, in parte obliterata da frane minori e colmata da depositi colluviali derivanti dalla degradazione delle scarpate. ai piedi del centro storico è stata rilevata una seconda trincea, quasi in continuità con la precedente sebbene si presenti lievemente ribassata. anche questa trincea è molto evidente in alcuni tratti, nonostante sia in larga parte obliterata dall’edificazione della zona bassa del paese. la presenza delle due trincee allineate nella parte alta del versante sud-occidentale permette di delimitare verso monte il movimento gravitativo profondo. verso nord la trincea perde continuità in corrispondenza del fosso, che dalla chiesetta di santa maria stella va a confluire, con direzione ne-so in sinistra idrografica, nel torrente bruscata. si tratta verosimilmente del fianco destro del movimento franoso. il limite sud-orientale segue il fosso che si origina a se del cimitero e prosegue fino ad arrivare in prossimità di masseria bruscata per poi confluire anch’esso nel torrente bruscata. il limite inferiore del movimento gravitativo profondo ha interessato il fondovalle del torrente bruscata che nel tempo ha subito uno spostamento del proprio percorso verso sw dando vita ad un andamento arcuato e determinando l’erosione della sponda opposta, come si può osservare dalle carte geomorfologiche (figg. 4-5). le dimensioni del movimento gravitativo profondo di versante corrispondono ad una larghezza media di circa 2,6 km ed una lunghezza media di circa 1 km, mentre per quanto riguarda la profondità, ricavata da ricostruzioni geometriche, si può affermare che è certamente superiore a 100 m (fig. 6). infatti, una superficie di scivolamento posta a profondità minore, non sarebbe stata in grado di mobilizzare in massa un movimento delle dimensioni appena citate. in passato sono stati eseguiti numerosi sondaggi geognostici nell’area della frana del centro storico (fig. 5), ma nessuno di questi ha raggiunto la superficie di scorrimento. del prete & petlej (1982) interpretano la frana del centro storico come uno scorrimento retrogressivo con sviluppo a colata, ipotizzando un piano di scivolamento ubicato a 620 fig. 6 sezione schematica del movimento gravitativo profondo di craco e possibili superfici di scorrimento. schematic cross section of the deep-seated gravitational slope deformation of craco illustrating the possibile sliding surfaces. m. bentivenga, m. coltorti & g. prosser circa 70 m dal piano campagna. infatti, profondità elevate giustificano facilmente come il muro di sostegno ad archi (fig. 7a) e quello costruito successivamente su pali profondi solo 30 m (fig. 7b), sono stati divelti in poco tempo. il movimento gravitativo profondo presenta un settore settentrionale in cui la trincea, anche se visibile, è stata modellata nel tempo dai processi erosivi e dove non sono state rilevate fratture e deformazioni. come è facilmente deducibile anche dai dati storici, queste evidenze geomorfologiche indicano che si tratta di un fenomeno con attività ricorrente, suddiviso in settori a vario grado di attività. il settore settentrionale presenta dunque il grado di attività più basso osservato nell’area, mentre la parte centro-meridionale del movimento risulta essere notevolmente più dinamica e questo si evince facilmente dalla presenza di numerose frane superficiali, favorite dalla presenza di acque non regimate, che a monte hanno colmato localmente la trincea per poi svilupparsi verso valle per tutta la lunghezza del versante. lungo il versante le frane superficiali sono classificabili come scivolamenti rotazionali con sviluppo a colate, la componente rotazionale è evidenziata da trincee minori e contropendenze. l’attivazione o riattivazione delle 621 fig. 7 – a) resti del muro ad archi costruito nel 1888; b) muro di sostegno su pali costruito nel 1968. a) remains of the wall with archs built in 1888; b) breast wall built on piles in 1968. il movimento gravitativo profondo ... frane superficiali genera nell’area di distacco scarpate con pendenze elevate successivamente interessate da piccole colate. la presenza di un settore con basso grado di attività, ed altri caratterizzati da una mobilità notevole, ci permette di affermare che il centro abitato di craco è stato interessato dalla riattivazione di un movimento gravitativo profondo. nella parte medio-bassa del movimento gravitativo profondo sono presenti aree interessate da diffusi fenomeni di erosione concentrata che hanno generato nel tempo evidenti forme calanchive. rilevata la larghezza totale del movimento gravitativo profondo di versante e constatato che la porzione più attiva è quella centro-meridionale, si può affermare che il movimento interessa l’intero versante con un piano di scivolamento profondo ubicato nei pressi del fondovalle. la geometria della superficie di scivolamento, che si raccorda alla trincea, può essere sia listrica che biplanare (hutchinson, 1988) (fig. 6). la forte rielaborazione della parte superiore del versante impedisce maggiori differenziazioni. analisi multitemporale l’analisi multitemporale permette di individuare tutti gli elementi utili per stabilire la sequenza degli eventi che hanno portato all’assetto attuale del territorio. l’interpretazione fotogrammetrica, eseguita dalle foto aeree relative al volo 1954-55 del i.g.m, ha permesso la realizzazione di una carta geomorfologia di tutta l’area studiata (fig. 5). per avere un confronto ed evidenziare le modifiche avvenute fino ad oggi, si è ritenuto necessario definire la geomorfologia attuale della stessa area, utilizzando le foto aeree relative al volo del 1991-1992, eseguito sempre dall’i.g.m., assieme a ripetuti riscontri sul terreno (fig. 4). dal confronto delle due carte geomorfologiche è stato possibile osservare il diverso stato di attività di numerosi movimenti franosi superficiali e la loro evoluzione. lungo il versante sud-occidentale della collina di craco sono stati individuati settori del movimento gravitativo profondo interessati da una evidente attività franosa superficiale rispetto ad altri che risultano essere poco interessati, nel lasso di tempo considerato, da riattivazioni. sono state osservate anche le piccole modifiche della rete idrografica e l’evoluzione dei fronti calanchivi che interessano la parte medio-bassa della dorsale di craco. l’analisi dei danni agli edifici permette inoltre di individuare i settori più attivi dei singoli corpi in movimento. sequenza morfoevolutiva tutta l’area di craco è stata soggetta, a partire dal pleistocene medio, a sollevamento. ciò ha portato al continuo adattamento della rete idrografica ai cambiamenti dei livelli di base sia locali che generali. il prevalente approfondimento vallivo ha generato versanti acclivi predisposti all’attivazione di movimenti di massa anche di notevoli dimensioni. di particolare ausilio nella comprensione delle dinamiche evolutive del versante è stata l’individuazione, ad est di masseria bruscata, di un piccolo lembo di terrazzo fluviale che si trova ad una quota di 180 m s.l.m. con una forma allungata in direzione nw-se. la presenza del terrazzo fluviale permette di affermare che l’area limitrofa non è stata interessata dal movimento gravitativo profondo di versante e che lo stesso si è attivato dopo la messa in posto dei depositi alluvionali terrazzati. lo stato di cattiva conservazione del ridotto terrazzo fluviale e l’assenza in tutto il resto della valle del torrente bruscata di altri lembi di terrazzi dello stesso ordine ben conservati, impedisce una sua attribuzione cronologica. si tratta ad ogni modo di un terrazzo la cui genesi è stata condizionata da una rapida aggradazione del fondovalle in condizioni climatiche che avevano indotto una completa eliminazione della coperture vegetale, verosimilmente durante una fase fredda ed arida del pleistocene. dato che si tratta del deposito più prossimo al fondovalle è verosimile che possa rappresentare l’ultima fase fredda pleistocenica (ois 3 e ois 2). a conferma di tale attribuzione, alla sua sommità non è stato osservato nessun indizio di una pedogenesi profonda con differenziazione importante degli orizzonti pedologici come quella attribuita all’ultimo interglaciale, segnalata alla sommità dei terrazzi del pleistocene medio finale del versante adriatico (coltorti et alii, 1991; coltorti & pieruccini, 2002). i sedimenti ghiaiosi non presentano neppure particolari evidenze di orizzonti petrocalcici che in genere sono quelli che maggiormente si preservano nel tempo. il terrazzo costituisce dunque il termine più antico della sequenza di eventi che hanno interessato il versante. se questa attribuzione fosse confermata, l’attivazione del movimento franoso sarebbe avvenuta durante l’olocene. l’evento franoso si è poi attivato in maniera unitaria interessando tutto il versante. il rilevamento geomorfologico ha però permesso di constatare che le frane superficiali attive si sono concentrate nella parte centro-meridionale dell’area in seguito a continui movimenti di riattivazione parziale. questi movimenti differenziati si erano già manifestati quando l’area è stata scelta per l’edif icazione del centro urbano nel medioevo. le case sono state edificate infatti lungo la trincea e nelle locali contropendenze. sono proprio gli effetti di questo ultimo evento e dei fenomeni di franosità superficiale associati, fronteggiati con interventi di bonifica inefficaci ed a volte mal progettati, che hanno portato all’abbandono coatto del centro abitato. la storia evolutiva recente delle frane di craco è documentata dagli atti depositati nell’archivio comunale. nel 1688 fu un terremoto (x° della scala mercalli) localizzato tra craco e pisticci, a riattivare numerose frane tra cui quella che interessa la parte bassa del paese, ma solo nel 1888 si cercò di limitare i danni al patrimonio abitativo costruendo un muro ad archi che appena dopo il suo completamento fu soggetto a spostamenti decimetrici. dopo un apparente periodo di inattività del movimento franoso nel 1954 fu costruito un campo sportivo su di un terrazzo di frana in leggera contropendenza al di sotto della s.s. n° 103 (fig. 5). la costruzione dell’impianto sportivo ha richiesto il livellamento di un’area estesa creando una sostanziale modifica del profilo del versante peggiorandone la stabilità. a scatenare la riattivazione nel 1959 fu una precipitazione eccezionale con 400 mm di pioggia in soli 5 giorni, che destabilizzò 622 m. bentivenga, m. coltorti & g. prosser completamente il campo sportivo, il muro ad archi ed alcune case al di sopra della s.s. n°103. tra la fine del 1963 e l’inizio del 1965, altre riattivazioni portarono al collasso del muro ad archi, all’interruzione della percorribilità della s.s. n°103 ed all’evacuazione di 153 abitazioni rese inagibili (fig. 8). nel 1968 fu decisa la costruzione di un altro muro, questa volta su pali che raggiungevano la profondità di 30 m pensando così di risolvere definitivamente il problema, ma le indagini geognostiche preliminari non misero in evidenza la reale profondità del movimento franoso che come sopra accennato deve estendersi ben al di sotto dei trenta metri. si evince quindi che i pali del muro non hanno oltrepassato lo spessore del materiale in frana, ma sono rimasti sospesi e divelti alla successiva riattivazione della frana. ad ogni modo, anche se essi avessero raggiunto il substrato stabile gli enormi sforzi di taglio non sarebbero stati arrestati dagli interventi sopra citati. la riattivazione della frana distrusse, oltre al muro costruito su una palificata, anche numerose case a monte della s.s. n°103, e fu in quel momento che si decise per l’abbandono del paese. indagini multidisciplinari fino ad oggi per capire la geometria dei corpi in movimento sono stati eseguiti indagini dirette su spessori limitati, mentre potevano dare una risposta più efficace quelle indirette che non sono mai state eseguite nell’area. i metodi geofisici sono infatti meno costosi ed in grado di mettere in evidenza sia la geometria delle frane superficiali che dei movimenti gravitativi profondi di versante. non sono inoltre disponibili misure topografiche di precisione che, se ripetute nel tempo, potevano aiutarci ad avere un’idea degli spostamenti prodotti sia dal movimento gravitativo profondo che da quelli relativamente più superficiali ed interessati da una velocità più differenziata. attualmente il monitoraggio di un’area con problematiche simili potrebbe essere effettuato servendosi di una rete di gps o dell’interferometria radar (strozzi et alii, 2001; turchi et alii 2003). le indagini geognostiche hanno interessato solo l’area della frana del centro storico, ma i sondaggi non hanno superato i 30 m di profondità e sono serviti solo al prelievo di campioni indisturbati per la caratterizzazione geotecnica sia delle argille varicolori che delle argille plioceniche. discussioni e conclusioni le evidenze geomorfologiche, come la presenza di trincee a monte e la deviazione ad arco del corso d’acqua sottostante, hanno permesso di stabilire che il versante sud-occidentale di craco è stato interessato da un movimento gravitativo profondo di versante. un’analisi geomorfologica preliminare del versante interessato da questo processo, ha permesso di valutare il diverso grado di attività che il movimento ha nei vari settori. i movimenti e l’attività dei processi sono stati riconosciuti anche attraverso una attenta analisi multitemporale, realizzando e mettendo a confronto due carte geomorfologiche relative rispettivamente alla situazione attuale ed a quella del 1954-55. l’elevato grado di attività del settore meridionale del movimento è inoltre confermato dalla presenza di frane più superficiali attive. la geometria dei sedimenti che costituiscono il substrato, in parte costituiti da corpi alloctoni fortemente caoticizzati, sembrerebbe più favorevole alla genesi di una serie di corpi franosi con evoluzione indipendente l’uno dall’altro. la notevole continuità laterale della trincea suggerisce invece che il movimento è stato in massa ed ha interessato le varie formazioni affioranti verosimilmente grazie alla presenza delle argille e soprattutto di intercalazioni sabbiose, abbastanza frequenti nella successione pliocenica. la circolazione idrica in pressione all’interno di questi livelli può aver costituito uno dei fenomeni predisponenti l’attivazione del fenomeno guidando l’ubicazione e l’attivazione della superficie di scivolamento. l’analisi geomorfologica di dettaglio ha permesso di ottenere informazioni riguardanti le dimensioni del movimento e la geometria dello stesso. la presenza di un piccolo lembo di terrazzo fluviale verosimilmente attribuibile al pleistocene superiore, ha permesso di delimitare l’area in frana e di ricostruire nel tempo, unitamente alle informazioni storiche, la sequenza degli eventi responsabili dell’assetto attuale del territorio. dopo aver individuato il problema dal punto di vista geomorfologico è possibile pianificare, con oculatezza e con limitate risorse economiche, una rete di monitoraggio che utilizza una o più tecniche tra quelle riportate in precedenza, ma tutte in grado di evidenziare gli spostamenti di qualsiasi settore del movimento gravitativo profondo di versante. inoltre, possono essere meglio scelte e realizzate le opere di intervento, come ad esempio la regimazione delle acque lungo il versante soggetto al degrado mediante dreni profondi, che abbassano il livello di falda, e canalette superficiali, che limitano l’infiltrazione delle acque. queste opere inspiegabilmente non sono state mai eseguite nell’area di craco. in una relazione di un geologo del servizio geologico d’italia (brugner, 1964) vengono evidenziate: • l’assenza di cunicoli di deflusso collegati ai drenaggi dei muri di sostegno; • consistenti perdite della rete idrica e fognaria; • presenza di piccoli laghetti sul corpo della frana del centro storico. il relatore conclude consigliando la realizzazione di opere capaci di regimare le acque lungo tutto il settore del versante interessato dalla frana del centro storico, ma questo negli anni successivi fu completamente disatteso contribuendo certamente alla continua riattivazione del movimento franoso. ringraziamenti si ringrazia il referee anonimo per i suoi utili suggerimenti. lo studio è stato possibile grazie al finanziamento “p.i.l. ex 60%” di mario bentivenga e giacomo prosser e del miur 2003 “approccio integrato allo studio delle strutture tettoniche attive intrappeniniche e dei movimenti gravitativi associati”, resp. mauro coltorti. 623il movimento gravitativo profondo ... 624 fig. 8 – a) veduta di craco; b) casa inclinata lungo il fianco sinistro della frana del centro storico. a) view of the craco village; b)tilted house in the craco village, along the left side of the landslide. m. bentivenga, m. coltorti & g. prosser bibliografia balduzzi a., casnedi r., crescenti u. & tonna m. (1982) il plio-pleistocene del sottosuolo del bacino lucano (avanfossa appenninica). geologca romana, 21, 89-111. bentivenga m., prosser g., prestera a. & sabia m. (2003) assetto strutturale nella zona frontale di una catena recente: l’esempio di craco (appennino meridionale italia). geologia dell’ambiente, 1, 89-98. bentivenga m., coltorti m. prosser g. & tavarnelli e., 2004 a new interpretation of terraces in the taranto gulf: the role of extensional faulting. geomorphology, 60, 383-402. brugner w. (1964) selle condizioni di stabilità dell’abitato di craco (provincia di matera). servizio geologico d’italia, largo s. susanna, 13, roma. carbone s., catalano s, lazzari s., lentini f. & monaco c. (1991) presentazione della carta geologica del fiume agri (basilicata). memorie della società geologica italiana, 47, 129-143. carrara a., d’elia b. & semenza e. (1985) classificazione e nomenclatura dei movimenti franosi. geologia applicata e idrogeologia, 20, 223-243. casero p., roure f., endignoux l., moretti i., müller c., sage l. & vially r. (1988) neogene geodynamic evolution of the southern apennines. memorie della società geologica italiana, 41, 109-120. cavallin a., crescenti u., dramis f., prestininzi a. & sorriso-valvo m. (1987) tipologia e diffusione delle deformazioni gravitative profonde di versante in italia. boll. soc. geol. it.. cavazza w., blenkisop j., de celles p.g., patterson r.t. & reinhardt e.d. (1997) stratigrafia e sedimentologia della sequenza sedimentaria oligocenico-quaternaria del bacino calabro-ionico di avanarco. bollettino della società geologica italiana, 116, 51-77. ciaranfi n. & d’alessandro a., (2005) overview of the montalbano jonico area and section: a proposal for the boundary stratotype of the lower-middle pleistocene in the southern italy foredeep. quaternary international, in press. coltorti m., consoli m., dramis f., genti l i b. & pambianchi g. (1991) evoluzione geomorfologica delle piane alluvionali delle marche centromeridionali. geogr. fis. din. quat., 14 (1), 87-100, torino. coltorti m. & pieruccini p. (2003) le pedosequenze dell’ultimo interglaciale nel contesto litoe morfostratigrafico del quaternario dell’appennino abruzzese. presentazione orale alle “giornate di studio: successioni continentali nell’appennino centro-meridionale.” aiqua-c.n.r. roma 2021/02/2003. del prete m. & petley d.j. (1982) case history of the main landslide at craco, basilicata, south italy. geologia applicata e idrogeologia, 17, 291-304. dramis f. (1984) aspetti geomorfologici e fattori genetici delle deformazioni gravitative profonde di versante. atti i sem. dgpv, boll. soc. geol. it., 103, 681-687. engelen (von) g.b. (1963) gravity tectonics in the north-western dolomites (n. italy). geol. ultraiectina, 13, 1-92. goguel j. (1978) scale-dependent rockslidemechanisms, with emphasis on the role of pore fluid vaporisation. in b. voight (ed.), rockslides and avalanches, develop, in geotechnical engineer, 14a, elsevier, amsterdam. hutchinson j.n. (1988) general report: morphological and geotechnical parameters of landslide in relation to geology and hydrogeology. proc 5th i.s.l. landslides, vol. 1, lausanne. lazzari s. & lentini f. (1980) note illustrative del f.507 pisticci. regione basilicata, potenza, 1-55. patacca e. & scandone p. (2001) late thrust propagation and sedimentary response in the thrust beltforedeep system of the southern apennines (pliocene-pleistocene). in: g.b. and i.p. martini (eds) “anatomy of a mountain the apennines and adjacent mediterranean basins”. kluwier acod publ.”. pescatore t. (1988) la sedimentazione miocenica dell’appennino campano lucano. memorie della società geologica italiana, 41, 37-46. pieri p., vitale g., beneduce p., doglioni c., gallicchio s., giano s.i., loizzo r., moretti m., prosser g., sabato l., schiattarella m., tramutoli m., tropeano m., (1997) tettonica quaternaria dell’area bradanico-ionica. il quaternario, 10 (2), 535542. roure f., casero p. & vially r. (1991) growth processes and melange formation in the southern apennines accretionary wedge . earth and planetary science letters, 102, 395-412. sella m., turci c. & riva a., (1988) sintesi geopetrolifera della fossa bradanica (avanfossa della catena appenninica meridionale). memorie della società geologica italiana, 41, 87-107. sorriso-valvo m. (1984c) presentazione. atti i sem. dgpv, boll. soc. geol. it., 103, 667-669. strozzi t., wegmuller u., tosi l., bitelli g. & volker s. (2001) land subsidence monitoring with differential sar interferometry. photogrammetric engeneering & remote sensing, 67, 11, 12611270. turchi d., casagli n., fanti r., leva d.,luzi g., pasuto a., pieraccini m., silvano s. (2003) landslide monitoring by using ground-based sar interferometry: an example of application to the tessina landslide in italy. engeneering geology, 68, 15-30. 625 ms. ricevuto l’1 giugno 2004 testo definitivo ricevuto il 7 dicembre 2004 ms. received: june 1, 2004 final text received: december 7, 2004 il movimento gravitativo profondo ... morphological and palaeoenvironmental evolution of the vendicio coastal plain in the holocene (latium, central italy) g. aiello1, d. barra1, t. de pippo1, c. donadio1, p. miele2 & e. russo ermolli1 1dipartimento di scienze della terra, università degli studi di napoli federico ii 2c/o dipartimento di scienze della terra, università degli studi di napoli federico ii 10, largo san marcellino – 80138 napoli (italy) corresponding author: prof. tommaso de pippo depippo@unina.it abstract: morphological and palaeoenvironmental evolution of the vendicio coastal plain in the holocene (latium, central italy). (it issn 0394-3356, 2007). morphological, stratigraphical and paleoecological studies carried out along the vendicio coastal plain (southern latium) allowed us to reconstruct the paleoenvironmental evolution of the plain in relation to holocene sea-level changes. on the basis of altitude, texture, microfossil and pollen content of sediments recovered in a 20 m borehole carried out on the backshore, three main transitional palaeoenvironments were recognised. particularly, the 14c dating of a peat layer at the boring base (-16 m a.s.l.), interbedded between sandy silt with organic matter and silty peat levels, gives an age of 7620 ±100 yr bp, equivalent to 8354-8524 cal yr bp. over these deposits, sands with pebbles, sometimes alternated with silt and sandy silt levels, lay. microfossil content, together with sediment features, confirms a transitional sequence from marsh (oligohaline) to lagoon (mesohaline-polyhaline), and finally to marine (littoral) environment, probably due to the last sea ingression related to the mid-holocene climatic optimum peak (~6000 years bp). pollen analysis reveals the existence of a deciduous forest association, rich in high-humidity demanding elements, by now not represented by a regional modern analogue. the present altitude of the dated peat level, correlated with the available eustatic curves, suggests that the vendicio sedimentary succession probably has been affected by a slight subsidence phase during mis 1. the occurrence of a slight subsidence may be also related to late quaternary vertical displacement of adjacent coastal sectors, and fits in with recent morphological evolutionary models of other minor coastal plains of latium. riassunto: evoluzione morfologica e paleoambientale della piana costiera di vendicio (lazio, italia centrale). (it issn 0394-3356, 2007). lo studio delle caratteristiche morfologiche, stratigrafiche e paleoecologiche, connesse a variazioni del livello marino, ha permesso di ricostruire l’evoluzione paleoambientale olocenica della piana costiera di vendicio, ubicata nel lazio meridionale. sulla base delle quote, dei caratteri tessiturali, dei microfossili e di analisi palinologiche condotte su campioni di sedimento, estratti da una carota della spiaggia emersa, sono stati riconosciuti tre differenti paleoambienti di transizione. in particolare un campione di torba alla base della carota (-16 m s.l.m.), posto tra alternanze di limi sabbiosi organici e livelli di torbe limose, ha fornito un’età radiometrica 14c di 7620 ±100 anni dal presente pari ad un’età calibrata di 8354-8524 anni bp. questa successione sedimentaria è troncata da depositi sabbiosi con ciottoli, talora alternati a livelli siltosi e siltoso-sabbiosi. le associazioni a microfossili calcarei di tali depositi, insieme ai caratteri sedimentologici, confermano una progressiva transizione da un ambiente oligoalino a mesoalino-polialino (da palustre a lagunare) ed infine il rapido passaggio a quello marino (litorale), in seguito all’ultima ingressione del mare correlabile al picco dell’optimum climatico medio-olocenico (~6000 anni bp). l’analisi pollinica indica la presenza di una ricca associazione di foresta decidua, con elementi tipici di suoli molto umidi, che non ha riscontro nell’attuale ambiente regionale. la correzione della quota di paleodeposizione del livello torboso datato, condotta mediante le curve eustatiche tratte dalla letteratura, suggerisce che la successione sedimentaria verosimilmente è stata interessata anche da una lieve fase di subsidenza della piana nel corso del mis 1. quest’ultima potrebbe essere connessa a movimenti verticali registrati nel tardo quaternario in settori costieri adiacenti alla piana, in accordo con i recenti modelli morfoevolutivi di altre piane costiere minori del lazio. key-words: coastal geomorphology, lagoons, sea-level changes, holocene, italy. parole chiave: geomorfologia costiera, laguna, variazioni del livello marino, olocene, italia. il quaternario italian journal of quaternary sciences 20(2), 2007 185-194 1 introduction the present study represents a further contribution to the understanding of the holocene sea level rise in southern latium minor coastal plains. a substantial stability of the rocky promontories and a slight subsidence in the plains is indicated for this coastal sector since mis 5.5 (lambeck et al., 2004a; ferranti et al., 2006). no other data are available for the holocene sealevel changes along this coastal zone, apart from geoarcheological evidences in the sites of sarinola and serapo which show during the roman age a sea level of about 1.35 m lower than the present-day (lambeck et al., 2004b). the recovery of a sediment core, on the backshore of the vendicio beach, allowed a paleoenvironmental reconstruction to be performed through paleoecological, sedimentological and palynological analysis and correlated with the evolution of adjacent coastal sectors during the early holocene, where differential vertical movements occurred especially in quaternary times (bordoni & valensise, 1998; antonioli et al., 2006; de pippo et al., 2007). 2 geological and geomorfological outline the vendicio coastal plain is located in southern latium and extends for about 2 km from the headland 186 g. aiello et al. of mount conca, to the w, to marina di castellone, to the e (fig. 1). the coastal sector is bounded, to the ne and nw, by nw-se faults. one of such faults, named gaeta-itri-monte calvo, sharply separates the northeastern area, where cretaceous carbonate dominates, from the southwestern area, where triassic-giurassic dolomite outcrops prevail (servizio geologico d’ital ia, 1968). moving further away from this line and up in the succession more limestones, giurassic in age, are present, as one can observe along the slopes of lisantro and dragone mounts (de riso, 1964). finally, the coastal exposures show the top of the succession, mainly represented by cretaceous l imestones, followed by prevailingly continental pleistocene and holocene deposits (hearty et al., 1986a; 1986b; hearty, 1986; accordi & carbone, 1988). the carbonatic succession, heavily crossed by a network of structural discontinuity with apenninic (nw-se) and anti-apenninic (ne-sw) trends (ambrosetti et al, 1987; cerisola & montone, 1992; carrara, 1995a; 1995b; carrara et al., 1995), have a pronounced influence on the local geomorphological setting. owing to the strict correlation between the tectonic structure and the morphological evolution of the area, the slope of the relief are fault scarp or fault-line scarps, locally also modelled by karstic and denudation processes. therefore, the landscape is characterised by a series of hills often with a cone or truncated cone shape. their slopes are generally of a structural type and separate valleys, which develop according to local tectonic lines, mainly with nwse and ne-sw trends, subordinately e-w ones. the alternation of pocket beaches along the coast is also related to the presence of faults, prevailingly those ne-sw oriented. cliffs were also controlled by tectonics in their development, as noted for the dead or fossil cliffs of mount orlando and those of mount moneta, in the hinterland of the plain of sant’agostino, to the sw. the headland of mount orlando, the highest coastal relief, is constituted by cretaceous limestones with a prevalent eastward dip. the northern slopes are modelled with gentle forms covered by clastic deposits, such as the red sands referable to the lithologic unity called duna rossa antica (ancient red dune: blanc et al., 1953; bergomi et al, 1969; bono, 1985; dai pra, 1995), attributed to middle-upper pleistocene, and colluvial detritus partial ly pedogenesized and vegetated (valente, 1999). the cliff of mount conca, bordering the western side of the vendicio beach, continues under the sea down to about -5 m, where a sandy bottom is present. this coastal segment is characterised by a sandy beach, locally with pebbles, located between the rocky headlands of mount conca and formia. behind the modern dune ridge, hardly dismantled, a minor alluvial plain is also present, delimited in the ne by the southwestern slope of costamezza hill, a palaeocliff oriented nw-se, as the local tectonic alignments. evidence of ancient sea-level standings are scarce along the cliffs of the rocky headlands bordering the beach. at their bases a sandy bottom is usually present, which gently degrades down to -15/-25 m. steep slopes, in a range between -20 and -50 m depth, are present along the submerged southwestern sector. the ne-sw trend (antonioli, 1991; 1995; valente, 1999; miele, 2003) of such morphological elements suggests a structural control, which also influences the direction of the transversal elements, such as the wide fractures which tend to isolate stacks as at montagna spaccata, to the sw. here, some caves, remodelled both by waves and karstic phenomena, continue under the sealevel. along the southwestern coast, evidence of paleosea-level positions are numerous (antonioli et al., 2006; de pippo et al., 2007). in particular, along the slopes of fig. 1 geological outline of the vendicio coastal plain, between gaeta and formia (southern latium, central italy): 1) altitude (m a.s.l.); 2) isobath (-m a.s.l.); 3) mesozoic carbonatic outcrops; 4) miocene flysch; 5) pliocene conglomerate; 6) lower pleistocene-holocene carbonatic talus with pyroclastic levels; 7) upper pleistocene reddish eolian deposits (duna rossa antica formation); 8) upper pleistocene-holocene alluvial deposits; 9) holocene eolian deposits; 10) present-day sandy beach; 11) pleistocene detritic-alluvial fan; 12) fault: a) certain; b) presumed or buried. schema geologico della piana costiera di vendicio, ubicata tra gaeta e formia (lazio meridionale, italia centrale): 1) quota (m s.l.m.); 2) isobata (-m s.l.m.); 3) affioramenti carbonatici mesozoici; 4) flysch miocenico; 5) conglomerato pliocenico; 6) detrito carbonatico con livelli piroclastici del pleistocene inferiore-olocene; 7) depositi eolici rubefatti (formazione della duna rossa antica) del pleistocene superiore; 8) depositi alluvionali del pleistocene superiore-olocene; 9) depositi eolici olocenici; 10) spiaggia sabbiosa attuale; 11) conoide detritico-alluvionale pleistocenico; 12) faglia: a) certa; b) presunta o sepolta. moneta and lisantro mounts, sea-notches, marine terraces, fringe boring by bivalve such as litophaga litophaga linneo and drapes of sediments are present. some marine forms are also preserved along the fossil sea cliffs bounding the vendicio coastal plain. in the western area, along the mount conca cliff and at the back of the waterfront, a sea-notch can be observed at about +0.5 m, bored by l. litophaga linneo. some relics of marine terraces are also present, partially covered by breccias probably referable to the würm regression (mis 2). such breccias are heterometric, seaward dipping, often rubefact in the matrix. in the lower stratigraphic terms mollusc shell debris occurs, consisting of minute bivalve (i.e. glycymeris sp.) and gastropod fragments. such deposits, originated in the intertidal zone, where clasts either from the sea and from the land were deposited without a significant transport, are rather diffuse along this coast, even if sometimes with a negligible thickness. a careful observation of the isobaths, concave seaward in the area in front of the beach and convex and close together in the area where the rocky coast is stretched out, confirms that, under the loose sedimentary mantle which at present covers the sea-bottom, the morphology of the submerged coast, characterised by marine terraces (segre, 1949; antonioli, 1991; 1995), is controlled by the same structural pattern of the emerged area. 3 materials and methods a 20 m long soil boring was carried out on the backshore of the vendicio plain (fig. 2). a peat level is present at the boring base (-16 m a.s.l.), interbedded between sandy silt with organic matter and silty peat levels (a: between -17 and -3 m a.s.l.). the ams 14c dating of the bulk (geochron laboratories usa, sample nr. gx-32021) gives a 7620±100 yr bp age equivalent to 8354-8524 cal yr bp (calib 5.01 – stuiver & reimer, 1993; reimer et al., 2004). above these deposits, sand with pebbles, sometimes alternated with silt and sandy silt levels, lay (b: between -3 and -1.5 m). finally, over these sediments an anthropogenous top soil formed by colluvial layers, carbonatic boulders with litophaga litophaga boreholes, pebbles, sand and landfi l l , lay. (c: between -1.5 and +3 m a.s.l. ) . geomorphological surveys have been performed along the emerged coastal belt, characterised by limestone cliffs bordering a plain with dune ridge and partially anthropised. the geomorphological features have been considered in order to obtain a complete outline of the morphostructural arrangement of the investigated area. environmental features related to ancient positions of the sea-level have been recognised and interpreted, and therefore ascribed to a certain chronological interval thanks to the 14c dating of a boring sample. the correspondence existing between some of the recovered elements, their dating and the sea-level position in the last 8400 years (mis 1), allowed a correlation with the eustatic curves relative to the tyrrhenian sea in the same range of time. remarkable discrepancies exist among the eustatic curves plotted for different geographic areas. therefore, the curve covering the last 22.000 years, after alessio et al. (1996), and 187morphological and palaeoenvironmental evolution ... fig. 2 1) stratigraphic log of the soil boring (s) carried out on the backshore of vendicio: a) darkish sandy silt with organic matter, blackish peat and silty peat levels (brackish with fresh water environment); b) greyish and yellowish fine sand with limestone pebbles, sometimes with greyish silt and sandy silt levels interbedded (littoral environment); c) anthropogeneous top soil formed by carbonatic boulders with lithodomus boreholes, pebbles, sand and landfill (continental environment); 2) paleosalinity diagram of soil boring base, desumed from microfossil association analysed in the sediments: a1) oligo-mesohaline environment; a2) presumed oligo-mesohaline environment; a3) meso-polyhaline environment; *) dated peat sample (7620±100 yr bp 14c age equivalent to 8354-8524 cal yr bp); v1 = sample for palaeoecological and pollen analyses. altitudes are related to present-day sea-level (±m a.s.l.). 1) stratigrafia dei terreni presenti nel sondaggio (s) ubicato nella spiaggia alta di vendicio: a) limi sabbiosi organici, torbe e livelli di torba limosa di colore nerastro (ambiente salmastro con acque dolci); b) sabbie fini grigiastre e giallastre con ciottoli calcarei, talvolta con intercalazioni di livelli limosi e limososabbiosi (ambiente litorale); c) suolo di genesi antropica formato da blocchi carbonatici con fori di litodomi, ciottoli, sabbie e terreno di riporto (ambiente continentale); 2) diagramma della paleosalinità dei depositi presenti alla base del sondaggio, desunto dall’analisi delle associazioni di microfossili nei sedimenti: a1) ambiente oligo-mesoalino; a2) presunto ambiente oligo-mesoalino; a3) ambiente meso-polialino; *) campione di torba datato (età 14c di 7620 ±100 anni bp, equivalente a 8354-8524 anni bp calibrati); v1 = campione per analisi paleoecologiche e polliniche. le quote sono riferite al livello marino attuale (±m s.l.m.). 188 that covering the last 10.000 years, after lambeck et al., (2004a), both plotted by those authors with data collected in the more stable coastal areas of the tyrrhenian sea, were chosen as a reference. paleoecological and palynological analysis were only carried out on the lower part of the core where the sediment grain size and nature was more suitable for fossil preservation. eleven core samples (300 g dried weight) were disaggregated, washed with water through 200 mesh sieves (75 µm) and analysed with the aim of studying calcareous microfossil assemblages. attention was focused especially on ostracod and foraminifer taxa. all the samples yielded at least a few calcareous fossil remains. assemblages are characterised by the presence of ostracods, benthic foraminifers, bivalves, gastropods (shells and opercula) and charophyte oogonia. pollen analysis was carried out on 8 core samples, from -16.55 to -15.15 m a.s.l. chemical (hcl and hf) and physical (10µ filtering 200µ, heavy liquid separation) procedures were used to concentrate the pollen grains in the residue. all samples resulted rich and with a good pollen preservation. pollen sums range from 379 to 684 pollen grains. concentration values oscillate around 70-100.000 grains/g and reach about 200.000 grains/g in the richest levels. 4 calcareous microfossil assemblages the benthic foraminifer assemblages include six species pertaining to five genera; the ostracod assemblages consist of seven species in seven genera. taxa are listed in table 1. some species have been figured in plate 1. semiquantitative abundance of fossil taxa in the samples is represented by the following abbreviations: vr (very rare), r (rare), u (uncommon), c (common), a (abundant). palaeoecological interpretations follow the modern literature on recent paralic/shallow-marine benthic foraminifers and ostracods (i.a. barbeitogonzalez, 1971; hiller, 1972; bonaduce & masoli, 1974; vesper, 1975; bonaduce et al., 1976; hartmann & hiller, 1977; meisch, 2000). the studied specimens are housed in the aiello barra micropaleontological collection (a.b.m.c.), dipartimento di scienze della terra, università degli studi di napoli federico ii, naples (italy). assemblage analysis allows the analysed section to be subdivided into three intervals (fig. 2): a1 – the lowermost sample, v1, yielded an ostracod assemblage dominated by candona neglecta and, subordinately, by potamocypris fallax. ilyocypris bradyi is rare as well as gastropods. these species indicate a tab. 1 semiquantitative distribution of the calcareous remains in the vendicio plain core (a = abundant, c = common, u = uncommon, r = rare, vr = very rare). distribuzione semiquantitativa dei microfossili calcarei presenti nel sondaggio della piana di vendicio (a = abbondante, c = comune, u = poco comune, r = raro, vr = molto raro). samples v1 v2 v3 v4 v5 v6 v7 v8 v9 v10 v11 depth (m a.s.l.) taxa foraminiferida ammonia tepida cushman, 1926 c u c r a u c bolivina sp. vr elphidium cuvilleri lévy, 1966 u vr vr elphidium paralium (tintant, 1954) u u c vr u fursenkoina acuta (d'orbigny, 1846) vr quinqueloculina milletti (wiesner, 1912) c c a u u ostracoda ilyocypris bradyi sars, 1890 vr r candona neglecta sars, 1887 a r cyprideis torosa (jones, 1850) a a a u c c leptocythere rara (g.w. müller, 1894) vr loxoconcha stellifera g.w. müller, 1894 u c c c u u potamocypris fallax fox, 1967 c pseudocandona sp. vr bivalvia r a c a a r r gastropoda u vr u u u c a u a u u characeae vr vr 16 .5 516 .6 0 16 .3 016 .3 5 16 .1 516 .2 0 15 .9 015 .9 5 15 .7 015 .7 5 15 .5 015 .5 5 15 .3 015 .3 7 15 .1 515 .2 0 14 .9 515 .0 0 14 .8 514 .9 0 14 .7 514 .8 0 g. aiello et al. 189 plate 1 fig. 1 quinqueloculina milletti , 4 chamber side, v9, (x 67). fig. 2 elphidium paralium, side view, v9, (x 53). fig. 3 elphidium cuvilleri, side view, v9, (x 37). fig. 4 ammonia tepida, spiral side, v9, (x 48). fig. 5 cyprideis torosa, left valve, v7, (x 68). fig. 6 cyprideis torosa, right valve, v7, (x 77). fig. 7 loxoconcha stellifera, right valve female, v7, (x 66). fig. 8 loxoconcha stellifera, right valve male, v7, (x 76). fig. 9 potamocypris fallax, left valve, v1, (x 68). fig. 10 leptocythere rara, right valve, v9, (x 75). tav. 1 fig. 1 quinqueloculina milletti, veduta del lato a 4 camere, v9, (x 67). fig. 2 elphidium paralium, veduta laterale, v9, (x 53). fig. 3 elphidium cuvilleri, veduta laterale, v9, (x 37). fig. 4 ammonia tepida, veduta del lato spirale, v9, (x 48). fig. 5 cyprideis torosa, valva sinistra, v7, (x 68). fig. 6 cyprideis torosa, valva destra, v7, (x 77). fig. 7 loxoconcha stellifera, valva destra femminile, v7, (x 66). fig. 8 loxoconcha stellifera, valva destra maschile, v7, (x 76). fig. 9 potamocypris fallax, valva sinistra, v1, (x 68). fig. 10 leptocythere rara, valva destra, v9, (x 75). morphological and palaeoenvironmental evolution ... 190 depositional paleoenvironment characterised by continental, oligohaline to mesohaline, relatively cold (<20°c), stagnant waters. benthic foraminifers are not present; a2 – the overlying interval is represented by three samples (v2, v3, v4) devoid of both ostracod and foraminifer specimens. calcareous fossil remains are represented exclusively by rare gastropods fragments and opercula. the sediment consists largely of carbonaceous matter derived from plant remains. the accumulation of organic matter generates the formation of acidic bottom and pore waters, due to the high concentration of metabolically produced carbon dioxide (co2). a low carbonate saturation index may cause the dissolution of the delicate ostracod shells. consequently, these sediments possibly indicate the effect of a cold and arid climate phase in a swampy environment (i.a. gliozzi & mazzini, 1998; belis et al., 1999); a3 – in the seven samples belonging to the upper part of the core (v5 – v11) benthic foraminifers are present and the fossil assemblages are generally richer and less oligotypic than in lower deposits. these portions show a more or less marked influence of marine waters, and the assemblages indicate four different paleoenvironments: samples v5, v6, v7, v11. ostracod assemblages consist of two species: cyprideis torosa, which is very abundant, and, subordinately, loxoconcha stellifera. the foraminifer assemblages are characterised by ammonia beccarii, quinqueloculina milletti and the genus elphidium (these latter not present in sample v6). the assemblages evidence a deposition in polyhaline waters; sample v8. abundant carbonaceous matter, rare specimens of ammonia beccarii and elphidium cuvilleri and the absence of ostracod shells indicates that these sediments were deposited in conditions similar to those in interval 2, but in polyhaline waters; sample v9. three ostracod and six foraminifer species occur, including leptocythere rara, fursenkoina acuta and bolivina which are recorded exclusively in this assemblage. the highest diversity possibly corresponds with the maximum influence of sea waters; sample v10. this assemblage is the only one which shows the presence of i lyocypris bradyi and pseudocandona sp., nonmarine taxa, together with the “marine-brackish” species l. stellifera, q. milletti and e. cuvilleri, suggesting a deposition in mesohaline-polyhaline waters, possibly with rapid (seasonal) salinity variations. 5 palynology pollen analysis results are presented in a detailed pollen diagram (fig. 3) where all the recognised taxa show their percentage values plotted against depth. the arboreal taxa percentage (ap/total curve in fig. 3) was calculated on a pollen sum excluding indeterminate grains, water plants and spores. ap values oscillate around 90% all along the investigated succession giving the image of a rather dense forested landscape (i.a. heim, 1970) in which the main arboreal elements were alnus, corylus, deciduous quercus, carpinus and ulmus. the only ap reduction is observed at 15.50 m depth where a rise in poaceae turns the ap down to fig. 3 detailed pollen diagram. taxa percentages are plotted against depth. diagramma di dettaglio dei pollini. le percentuali dei taxa sono restituite con le relative profondità. g. aiello et al. 68%. the arboreal taxa percentage (curve ap/total in fig. 3) oscillates from 60 to 80% giving the image of a rather dense forested landscape (i.a. heim, 1970). the main arboreal elements are alnus, corylus, deciduous quercus, carpinus and ulmus. deciduous quercus and carpinus do not show important variations. they probably represent the main elements of a slope forest association, established on well drained soils. on the contrary alnus, corylus and ulmus, which are high soil-humidity demanding elements, show more significant percent variations maybe linked to waterbed oscillations. in fact, they should have occupied the vendicio plain in a forestal association by now not represented by a regional modern analogue. vegetation associations dominated by alnus, corylus, carpinus and ulmus now characterise high humidity environments linked to microclimatic conditions, well represented all over italy (pedrotti & gafta, 1996). these elements are also commonly present in alluvial environments of temperate regions in central europe (polunin & walters, 1987) where they form plain-wood strips, by now relicts in italy and have almost disappeared from southern italy, a part from the higrophylous woods of mount circeo (stanisci et al., 1998). small amounts of fagus and betula are the only representatives of the mountainous vegetation belt. mediterranean elements are present but rare all along the analysed succession apart from a slight increase in quercus ilex towards the top. poaceae are the main representatives of the herbaceous elements; their percentages are always below 10% apart from the sample at -15.50 m where they reach 30%. the low percentage of spores and the relative lower percentages of alnus at the same core depth could indicate the reduction of dump soils around the drilling site. cyperaceae are rare but show a slight increase at -15.90 and -16.15 m; the correspondence with the highest values of alnus could indicate the extension of wetlands in the vendicio plain. it is very interesting from a phytogeographical and bioclimatic point of view the constant presence of vitis sp.. the species vinifera, as its wild representative, are now associated with the above mentioned arboreal elements in thermophilous humid forests from central to southern italy (pignatti, 1982) even if the wild representative is in constant regression all over europe (arnold et al., 1998). the 14c age of 7620+/-100 yr bp (8354-8524 cal yr bp) obtained at -16 m a.s.l. places the analysed succession at the beginning of the atlantic chronozone (about 9000-5700 cal yr bp), the holocene thermal optimum (ravazzi, 2003), which is characterised by wetter (about +200 mm/a) and cooler (about -1.5°c tann) climatic conditions in respect to modern values (terral & mengual, 1999; davis et al., 2003; magny et al., 2003). these climatic conditions associated with the humid edaphic conditions typical of a coastal plain can explain the existence of a forestal association like the one recognised in the core. 6 discussion and conclusions in this work the morphological and palaeoenvironmental evolution of the vendicio coastal plain is depicted for the first time (fig. 4) as sedimentological and ecological signatures of ancient coastlines. the analysed sedimentary succession starts in the early 191 holocene (about 8400 yr bp) and covers the main phases of the mid-holocene eustatic sea-level rise. three main transitional palaeoenvironments are recognised in the basal part of the core, on the basis of height, texture, microfossil and palinological analyses. pollen analysis reveals for the first time the existence of humid soils around the drilling site with the occurrence of a plain-forest where elements such as vitis are also recorded. microfossil assemblages together with sediment characteristics, indicate a transitional sequence from oligo-mesohaline to mesopolyhaline (from marsh to lagoon), and finally to marine (littoral) environment, due to the last sea ingression related to the mid-holocene climatic optimum peak (~6000 years bp). such environmental succession was also described in two 6 m long boreholes, carried out along the coastal sector west of formia. according to sewink et al. (1984), lagoonal clays with interbedded fine sand levels indicate a transition from brackish, with fresh water, to marine-brackish, probably littoral, environment. these deposits, intercalated towards the top with several paleosoils, are locally covered by roccamonfina tuffs, after an erosive phase. over this volcanic material, reddish, yellowish and reddish brown eolian sands as well as anthropogeneous colluvial layers are present, confirming the evolution towards a continental environment. in order to delineate the morphodynamic evolution of the vendicio coastal plain in the holocene, two eustatic curves (alessio et al., 1996; lambeck et al., 2004a), were chosen as a reference. the present position of the dated peat level in the study soil boring (-16 m a.s.l.) could indicate both stable conditions or the occurrence of a slight subsidence in the plain, in agreement with literature data (ferranti et al., 2006). on the basis of the chosen references, the sea level position at 8400 years bp was about -15 m lower than the present. the dated peat position at -16 m is consistent with a marsh to shallow water lagoon environment, in stable tectonic conditions. however, a slight subsidence could also be deduced for the considered time interval. no data are specifically available in this area which could better detail the sea level rise during the early holocene, but at 2000 years bp considering geoarchaeological data alessio et al. (1996) indicate a sea level of about 0.6-1.5 m lower than the present, while lambeck et al. (2004b) calculate a sea level of about 1.35 m lower than the current for the sites of sarinola and serapo, close to the study area. as a matter of fact differential movements between adjacent coastal sectors have occurred up to recent times (de pippo et al., 2007). such movements would have occurred along the nw-se faults that represent the borders of the pocket beach system characterising the entire coastal physiography. moreover, such discontinuities act as unblocking elements for adjacent coastal sectors. this fact suggests that the coastline did not behave homogeneously during the late quaternary tectonic phases, as hypothesized for some sectors of the campanian coastline (cinque & romano, 1990; de pippo et al., 1998; esposito et al., 2003). such dislocations, which occurred in the studied coast, can be referred to a sector of the central apennine included between the two main coastal plains of fondi and formia-garigliano where a slight subsimorphological and palaeoenvironmental evolution ... 192 fig. 4 probable palaeoenvironmental evolutionary model of the vendicio coastal plain, desumed from soil borings (see fig. 2 and citations) and morphological features; a) upper pleistocene lower holocene: marsh environment characterised by a coastal pond with debouching stream, dune ridge and beach; b) 8400 years bp mid holocene: development of the lagoon with bebouching stream and the mouth cutting the dune; retreating beach due to sea level rise; c) mid holocene present-day: gradual disappearance of the dune and lagoon; beach retreat due to both sea level rise and recent strong anthropogeneous intervention along the plain; 1) carbonatic rock; 2) duna rossa antica (ancient red dune) formation; 3) carbonatic talus; 4) marsh deposits; 5) eolic deposits 6) marine deposits; 7) lagoon deposits; 8) landfill. the blockdiagram is not in scale; the vertical wired arrow shows the sea level rise, while the horizontal grey the shoreline retreat. modello della probabile evoluzione paleoambientale della piana costiera di vendicio, desunto da sondaggi (cfr. fig. 2 e citazioni) e caratteri morfologici; a) pleistocene superiore olocene inferiore: ambiente palustre con stagno costiero alimentato dal corso d’acqua, cordone dunare e spiaggia; b) 8400 anni bp olocene medio: sviluppo della laguna alimentata dal corso d’acqua, con foce che disseca la duna; spiaggia in arretramento a seguito dell’ingressione marina; c) olocene medio attuale: graduale scomparsa della duna e del retrostante ambiente lagunare; arretramento della spiaggia a seguito sia dell’ingressione marina sia dell’intensa antropizzazione recente della piana; 1) roccia carbonatica; 2) formazione della duna rossa antica; 3) detrito carbonatico; 4) depositi palustri; 5) depositi eolici; 6) depositi marini; 7) depositi lagunari; 8) colmata artificiale. il diagramma stereo non è in scala; la freccia verticale indica la variazione del livello marino, mentre quella orizzontale grigia l’arretramento della linea di riva. g. aiello et al. dence is recorded. in fact, according to recent papers, the whole eastern tyrrhenian margin can be considered from stable to slowly subsiding from mis 5.5 (ozer et al., 1987; ferranti et al., 2006), even if in southern latium local uplift movements are estimated (de pippo et al., 2007). references accordi g. & carbone f. (1988) sequenze carbonatiche meso-cenozoiche. in: g. accordi, f. carbone, g. civitelli, l. corda, d. de rita, d. esu, r. funiciello, t. kotsakis, g. mariotti & a. sposato (eds.), note illustrative della carta delle litofacies del lazio-abruzzo ed aree limitrofe, c.n.r., quad. de «la ricerca scientifica», 114, 11-92. alessio m., allegri l., antonioli f., belluomini g., improta s., manfra l. & preite martinez m. (1996) la curva di risalita del mare tirreno negli ultimi 43ka ricavata da datazioni su speleotemi sommersi e dati archeologici. mem. descr. carta geol. d’it., 52, 261-276. ambrosetti p., bosi c., carraro f., ciaranfi n., panizza m., papani g., vezzani l. & zanferrari a. (1987) neotectonic map of italy. foglio n.6, scala 1:500.000, prog. fin. geodinamica, c.n.r., roma. antonioli f. (1991) geomorfologia subacquea costiera del litorale compreso tra punta stendardo e torre s. agostino (gaeta). il quaternario, 4 (2), 257-274. antonioli f. (1995) ricostruzione di variazioni climatiche quaternarie attraverso indagini subacquee. in: lazio meridionale sintesi delle ricerche geologiche multidisciplinari. enea, dip. ambiente, 52-58. antonioli f., ferranti l. & kershaw s. (2006) a glacial isostatic adjustment origin for double mis 5.5 and holocene marine notches in the coastline of italy. quaternary international, 145-146, 19-29. arnold c., gillet f. & gobat j.m. (1998) situation de la vigne sauvage vitis vinifera ssp. sylvestris en europe. vitis, 37, 159-170. barbeito-gonzalez p.j. (1971) die ostracoden des köstenbereiches von naxos (griechenland) und ihre lebensbereiche. mitteilungen aus dem hamburgischen zoologischen museum und institut, 67, 255-326, 47 pls. belis c.a., lami a., guilizzoni p., ariztegui d. & geiger w. (1999) the late pleistocene ostracod record of the crater lake sediments from lago di albano (central italy): changes in trophic status, water level and climate. j. paleolimnol., 21, 151-169. bergomi c., catenacci v., cestari g., manfredini m. & manganelli v. (1969) note illustrative alla carta geologica d’italia. foglio 171 gaeta e vulcano di roccamonfina. serv. geol. d’it. blanc a.c., segre a.g. & tongiorgi e. (1953) le quaternaire de l’agro pontino. atti iv congr. int. inqua, roma-pisa. bonaduce g. & masoli m. (1974) ostracofaune delle lagune di marano e grado. diffusione ed ecologia. boll. soc. adriatica sc. trieste, 59, 33-105. bonaduce g., ciampo g. & masoli m. (1976) distribution of ostracoda in the adriatic sea. pubblicazioni della stazione zoologica di napoli, 40, suppl. 1, 304 pp. bono p. (1985) seminario informativo sui risultati del progetto “laghi costieri”. sintesi della relazione finale. univ. degli studi la sapienza, roma, vol. 1, 163 pp. bordoni p. & valensise g. (1998) deformation of the 125 ka marine terrace in italy: tectonic implications. geol. soc., london, special publ., 146, 71110. carrara c. (1995a) elementi di geologia regionale. in: lazio meridionale sintesi delle ricerche geologiche multidisciplinari. enea, dip. ambiente, 23-33. carrara c. (1995b) elementi di neotettonica. in: lazio meridionale sintesi delle ricerche geologiche multidisciplinari. enea, dip. ambiente, 34-36. carrara c., dai pra g. & paganin g. (1995) lineamenti di tettonica plio-quaternaria. in: lazio meridionale sintesi delle ricerche geologiche multidisciplinari. enea, dip. ambiente, 151-155. cerisola r. & montone p. (1992) analisi strutturale di un settore della catena dei monti ausoni aurunci (lazio, italia centrale).boll. soc. geol. it., 111, 449-457. cinque a. & romano p. (1990) segnalazione di nuove evidenze di antiche linee di riva in penisola sorrentina (campania) . geografia fisica e dinamica quaternaria, 13, 23-25. dai pra g. (1995) geomorfologia e stratigrafia dei depositi del pleistocene e dell’olocene. in: «lazio meridionale sintesi delle ricerche geologiche multidisciplinari». enea, dip. ambiente, 36-50. davis b.a.s., brewer s., stevenson a.c., guiot j. & data contributors (2003) the temperature of europe during the holocene reconstructed from pollen data. quaternary science reviews, 22, 1701-1716. de pippo t., donadio c. & sgrosso a. (1998) geomorfologia sottomarina di una settore della penisola sorrentina (campania). geogr. fis. din. quat., 21, 103-110. de pippo t., donadio c., miele p. & valente a. (2007) morphological evidence for late quaternary tectonic activity along the coast of gaeta (central italy). geogr. fis. din. quat., 30, 43-53. de riso r. (1964) osservazioni geologiche sui monti di gaeta. mem. e note ist. geol. appl. napoli, 9, 521. esposito c., filocamo f., marciano r., romano p., santangelo n., scarmiglia f. & tuccinei p. (2003) late quaternary shorelines in southern cilento (mt. bulgheria): morphostratigraphy and chronology. il quaternario, 16 (1), 3-14. ferranti l., antonioli f., mauz b., amorosi a., dai pra g., mastronuzzi g., monaco c., orrù p., pappalardo m., radtke u., renda p., romano p., sansò p. & verrubbi v. (2006) markers of the last interglacial sea-level high stand along the coast of italy: tectonic implications. quaternary international, 145-146, 30-54. gliozzi e. & mazzini i. (1998) palaeoenvironmental analysis of the 250.000-year sediment core of valle di castiglione (latium, italy) using ostracods. bull. centre rech. elf explor. mem., 20, 69-81. hartmann g. & hiller d. (1977) beitrag zur kenntnis der ostracodenfauna des harzes und seines nörd193morphological and palaeoenvironmental evolution ... l ichen vorlandes (unter besonderer berücksichtigung der männches von candona candida). jahre naturwissenschaftlicher verein goslar, 125, 99-116. hearty p.j. & dai pra g. (1986a) aminostratigraphy of quaternary marine deposits in the lazio region of central italy. zeit. geomorph. n. f., 62, 131-140. hearty p.j. (1986) an inventory of last interglacial (s.l.) age deposits from the mediterranean basin: a study of isoleucine epimerization and u-series dating. zeit. geomorph. n. f., suppl. bd., 62, 5169. hearty p.j., miller g.h., stearns c.e. & szabo b.j. (1986b) aminostratigraphy of the quaternary shorelines in the mediterranean basin. geol. soc. am. bull., 97, 850-858. heim j. (1970) les relations entre les spectres polliniques récents et la végétation actuelle en europe occidentale. mem. soc. roy. belg., 4, 1-181. hiller d. (1972) unterschungen zur biologie und zur ökologie l imnischer ostracoden aus der umgebung von hamburg. archiv für hydrobiologie, supplement-band, 40 (4), 400-497. lambeck k., antonioli f., purcell a. & silenzi s. (2004a) sea-level change along the italian coast for the past 10,000 yr. quaternary science reviews, 23, 1567-1598. lambeck k., anzidei m., antonioli f., benini a. & esposito e. (2004b) sea level in roman time in the central mediterranean and implication for recent change. earth and planetary science letters, 224, 563-575. magny m., bégeot c., guiot j. & peyron o. (2003) contrasting patterns of hydrological changes in europe in response to holocene climate cooling phases. quaternary science reviews, 22, 15891596. meisch c. (2000) freshwater ostracoda of western and central europe, j. schwoerbel & p. zwick (eds.), spektrum adademischer verlag, heidelberg, germany, 8/3, 522 pp. miele p. (2003) relazione tra linee di riva e tettonica durante il quaternario nel tratto di costa tra marina di minturno e gaeta (lazio meridionale). tesi di dottorato di ricerca in geol. del sedim., dip. di scienze della terra, univ. degli studi di napoli federico ii, napoli, 219 pp. ozer a., demoulin a. & dai pra g. (1987) les indices morphologiques témoins de la stabilité tectonique de la bordure litorale du lazio méridional (italie). zeit. geomorph. n. f., suppl., 63, 103-117. pedrotti f. & gafta d. (1996) ecologia delle foreste ripariali e paludose dell’italia. l’uomo e l’ambiente, università degli studi di camerino, camerino, italy, 23, 162 pp. pignatti s. (1982) flora d’italia. ed. agricole, bologna, vol. iii, 451-620. polunin o. & walters m. (1987) guida alle vegetazioni d’europa. zanichelli ed., bologna, 232 pp. ravazzi (2003) an overview of the quaternary continental stratigraphic units based on biological and climatic events in italy. il quaternario, 16 bis, 1118. reimer p.j., baillie m.g.l., bard e., bayliss a., beck j.w., blackwell p.g., buck c.e., burr g.s., cutler k.b., damon p.e., edwards r.l., fairbanks r.g., friedrich m., guilderson t.p., herring c., hughen k.a., kromer b., mccormac f.g., manning s.w., ramsey c.b., reimer r.w., remmele s., southon j.r., stuiver m., talamo s., taylor f.w., van der plicht j., & weyhenmeyer c.e. (2004) intcal04 terrestrial radiocarbon age calibration, 0-26 cal kyr bp. radiocarbon, 46 (3), 1029-1058. segre a.g. (1949) tracce di morfologia subaerea sul fondo marino litoraneo del lazio meridionale. historia naturalis, anno iii, fasc. 1, 1-3. servizio geologico d’italia (1968) foglio 171 gaeta, carta geologica d’italia, ii ed., 1:100.000. sevink j., remmelzwaal a. & spaargaren o.c. (1984) the soils of southern lazio and adjacent campania. fys. geogr. bodemk. lab., universiteit van amsterdam, publ. nr. 38, 143 pp. stanisci a., presti g. & blasi c. (1998) i boschi igrofili del parco nazionale del circeo (italia centrale). ecologia mediterranea, 24, 73-88. stuiver m. & reimer p.j. (1993) extended 14c data base and revised calib 3.0 14c age calibration program. radiocarbon, 35 (1), 215-230. terral j.f. & mengual x. (1999) reconstruction of holocene climate in southern france and eastern spain using quantitative anatomy of olive wood and arcaeological charcoal. palaeogeography, palaeoclimatology, palaeoecology, 153, 71-92. valente a. (1999) aspetti geologici e geomorfologici del parco regionale di monte orlando (lazio meridionale , italia). mem. descr. carta geol. d’it., 54, 101-110. vesper b. (1975) ein beitrag zur ostracodenfauna schlleswig-holsteins. mitteilungen aus dem hamburgischen zoologischen museum und institut, 72, 97-108. 194 ms. ricevuto il 30 maggio 2007 testo definitivo ricevuto il 3 settembre 2007 ms. received: may 30, 2007 final text received: september 3 , 2007 g. aiello et al. impaginatodavanzo mmaammmmaall sskkeelleettaall rreemmaaiinnss ffrroomm tthhee ffuummaannee ccaavvee ((vveerroonnaa,, nnoorrtthheerrnn iittaallyy)):: aann ooxxyyggeenn iissoottooppee ssttuuddyy aanndd iittss ppaallaaeeoocclliimmaattoollooggiiccaall iimmpplliiccaattiioonnss ss.. ddaavvaannzzoo,, pp.. iiaaccuummiinn && aa.. lloonnggiinneellllii university of parma, department of earth sciences, parco area delle scienze 157/a, 43100 parma, italy abstract a stable isotope study of mammal skeletal remains of palaeolithic age from the fumane cave (verona, n. italy) was carried out to obtain palaeoclimatological information. the studied samples belong to capra ibex, cervus elaphus, capreolus capreolus and bos/bison sp. and come from various levels of the cave deposits of upper and mid palaeolithic age. the δ18o of palaeoenvironmental water was calculated from the δ18op measured on fossil samples, according to the isotope equations previously calibrated on modern specimens. the results obtained suggest that teeth must be considered with great caution for palaeoclimatic reconstruction: in the case of this study they yield quite unreliable results. in a general way, isotopically well-preserved bones are preferrable since the interpretation of their results is more straightforward, more reliable and more meaningful, the bone phosphate representing a mean value of a considerable period of the life of each specimen. the δ18ow calculated from bone samples indicate that the climatic conditions were colder than at present. further isotope data are of importance as a database for detailed reconstructions of the past climatic conditions along ns and ew geographic sections in europe. riassunto sono state eseguite misure della composizione isotopica del fosfato (δ18op) su resti di mammiferi fossili provenienti dalla grotta di fumane (verona) allo scopo di ottenere informazioni paleoclimatiche quantitative o almeno semiquantitative per il paleolitico mediosuperiore nella zona in esame. i campioni provengono da vari livelli di una successione stratigrafica divisa in quattro unità principali (s, br, a e d) ed appartengono alle specie capra ibex, cervus elaphus, capreolus capreolus e bos/bison sp.. i valori di δ18o delle “paleo” acque meteoriche sono stati calcolati a partire dai valori di δ18op misurati sui campioni fossili utilizzando le equazioni isotopiche preventivamente calibrate su individui recenti. i risultati ottenuti indicano che i denti non sono sempre utilizzabili per ricostruzioni paleoclimatiche e che, in generale, è preferibile utilizzare le ossa, almeno quando si ha a che fare con materiali non interessati da processi diagenetici. i valori di δ18ow (acqua paleoambientale) calcolati dai campioni di ossa confermano che il clima, nell’intervallo di tempo relativo alla successione esaminata, era sensibilmente più freddo di quello attuale. questi risultati costituiscono un utile apporto per dettagliate ricostruzioni delle variazioni climatiche nel passato lungo sezioni ns ed eo in europa. keywords: fumane cave, oxygen isotopes, palaeoclimatology, upper and mid-palaeolithic parole chiave : grotta di fumane, composizione isotopica dell’ossigeno, paleoclimatologia, paleolitico medio-superiore il quaternario italian journal of quaternary sciences 1155(1), 2002, 39-44 11.. iinnttrroodduuccttiioonn the fumane cave (verona-northern italy) has been studied by archaeologists for its deposits from palaeolithic age. the cave is located at about 350 m.a.s.l. on the lessini mountains (fig.1). it was repeatedly excavated throughout the last century and an extensive excavation (10 m of sediments) was carried out by the historical museum of verona and the sovraintendenza alle antichità from 1982 to 1983 and by the prehistoric and ethnographic museum “pigorini” of rome from 1987 to recent time (bartolomei et al., 1992a). the 10 m of sediments were divided into four units (d, a, br and s), each one in turn being subdivided into various levels and sublevels. 29 radiocarbon dates are available for 9 of the stratigraphic levels of the d and a units of the fumane cave. the d unit dates approximately from 27,000 to 32,000 bp and the a unit from 32,000 to 38,000 bp. (for a complete review see bartolomei et al., 1992a,b; cassoli and tagliacozzo, 1994; cremaschi et al., 1986; peresani and sartorelli, 1996). three thermoluminescence dates were carried out on burnt flint stones from levels br11, br12 and s7 yielding ages of about 55, 57 and 80 ka bp respectively (broglio, personal communication). deer and ibex are the most abundant faunal remains at fumane cave followed by roe deer, chamois and bovines with subordinated marmot and fox. these remains are essential ly human food refuse. micromammals are also well represented. the study of mammal assemblages and sedimentary analyses from the a and d units point to a wooded landscape and a cool climate at lower levels (a13-a3) and to an open landscape with a cold and arid climate at higher levels (a2-d1) (bartolomei et al., 1992b). 40 davanzo-iacumin-longinellii while the analyses of faunal assemblages from archaeological sites can yield only qualitative palaeoclimatological information, oxygen isotope analyses can provide a quantitative or semi-quantitative information of past climatic conditions in the case of suitable material. mammal bone and tooth oxygen isotope data enable the calculation of the mean oxygen isotope composition of environmental water throughout the period covered by the samples studied. in fact, the δ18op values can be converted into δ18o of palaeoenvironmental water by means of isotope equations calibrated on living specimens of the same species from different climatic areas (e.g. longinelli, 1984; longinelli, 1995; delgado huertas et al., 1995). these equations take into consideration the different metabolic processes characteristic of each species and the overall isotope fractionation of the oxygen taken in. in turn, the mean δ18o value of environmental water is related quantitatively to the yearly mean temperature at the ground. consequently, the δ18op values can be considered variables quantitatively related to palaeoclimatological conditions. 22.. mmaatteerriiaallss aanndd mmeetthhooddss the study was carried out on 119 mammal bone and tooth enamel samples belonging to cervus elaphus, capra ibex, capreolus capreolus and bos/bison sp. in the case of teeth, the enamel sample portion analysed was collected in such a way as to represent the whole period of tooth accretion. consequently, the intra-tooth variation related to seasonal climatic changes is considerably reduced. the samples were prepared according to well established procedures (crowson and showers, 1991 and lécuyer et al., 1993). the final sample of the chemical treatment is ag3po4.the phosphate oxygen is extracted from the samples by reacting the ag3po4 with brf5 at 600°c for about 15 hours. the oxygen is then purified and converted to co2 by cycling over hot graphite in the presence of a platinum catalyst; the co2 is measured for its 18o/16o ratios by means of a mass spectrometer (in this case a finnigan delta s). the isotope results are reported in the δ terminology versus the international v-smow standard. 33.. iissoottooppee rreessuullttss aanndd ddiissccuussssiioonn the phosphate oxygen isotope composition (δ18op) of the measured samples and the oxygen isotope composition of local environmental water (δ18ow) are reported in table 1 along with their stratigraphic position in the cave sedimentary sequence. the δ18ow was calculated from the δ18op values according to the equations suggested by d’angela and longinelli (1990) for cervus and bos and by delgado huertas et al. (1995) for capra and capreolus. the same δ18ow values are also reported graphically in figure 2. the δ18ow calculated from bone samples range from -10.2 to -6.2 per mil with a mean value of -7.8±0.8. the mean δ18ow calculated from tooth samples (-9.6±2.3) is surprisingly lighter than that of bone samples ranging between -13.4 and -3.9 per mil. in general, tooth enamel is considered the most reliable material for δ18op analyses due to its capability of retaining the pristine isotope value throughout long periods (e.g. ayliffe et al., 1994). however, tooth phosphate is not renewed during the lifetime of an individual and, consequently, it records the isotopic signature of climatic conditions referring to a very short period of the individual’s life (bryant et al., 1996; fricke and o’neil, 1996). this is particularly true for the teeth that mineralise during the weaning period which are affected by the nursing processes. in the case of our samples and particularly for the c. ibex from which a number of teeth were measured in the lower units (br and s) the δ18ow values calculated from teeth δ18op are systematically 18o-depleted when compared to δ18ow calculated from bone values, even from the same level (fig.2). only very few teeth values behave in the opposite way being 18o-enriched. since diagenetic processes normally affect preferentially bones leading to an 18o-depletion, this effect can hardly be ascribed to post-depositional processes. therefore, according to the results obtained the time period represented by the br and s units could be considered slightly colder than the period represented by the d and a units. however, this hypothesis is not confirmed by the measurements obtained from other species and, particularly, by the deer samples, several of which were analysed from the br and s levels. it may be inferred that: 1) the ibex fawns lived at a higher elevation; 2) they lived in an area where streams carried down isotopically lighter water from the nearby alpine glaciers; 3) that they were born in a given period so that the permanent teeth mineralised preferentially during the cold season. the 18o-enriched teeth values may be ascribed to the weaning period since milk water is considerably 18oenriched when compared to environmental water (luz et al., 1984). because of the great difference between bone and fig.1 location of the fumane cave, north-eastern italy. ubicazione della grotta di fumane. 41mammal skeletal remains ... lleevveell ssppeecciimmeenn sskkeelleettaall δδ 1188oo pp δδ 1188oo ww rreemmaaiinnss d1e c. ibex bone 17.2 -7.9 d1e c. ibex bone 17.7 -7.3 d1e+d1d c. ibex bone 16.8 -8.4 d1e+d1d c. ibex tooth 12.3 -13.4 d1d c. ibex bone 17.7 -7.3 d1d c. ibex bone 17.5 -7.5 d1c c. ibex bone 16.9 -8.2 d1c c. ibex bone 16.9 -8.2 d1c c. ibex bone 18.2 -6.7 d1a c. ibex bone 15.1 -10.2 d1a c. ibex tooth 20.7 -3.9 d3b c. ibex bone 17.4 -7.6 d3b c. ibex bone 17.9 -7.0 d3b c. ibex tooth 19.4 -5.4 d5 c. ibex bone 17.2 -7.8 d5 c. ibex bone 18.4 -6.5 d6 c. ibex bone 18.2 -6.7 d6 c. ibex tooth 15.2 -10.1 d6 c. ibex tooth 15.9 -9.3 d6 bos/bison sp. bone 16.7 -8.2 d6 bos/bison sp. bone 15.7 -9.1 d6 bos/bison sp. bone 17.9 -6.9 d6 bos/bison sp. bone 15.5 -9.3 a1 c. ibex bone 17.6 -7.4 a1 c. ibex bone 17.6 -7.4 a1 c. ibex bone 17.6 -7.4 a1 bos/bison sp. bone 17.3 -7.6 a1 bos/bison sp. tooth 12.8 -12.0 a2 c. ibex bone 17.7 -7.3 a2 c. ibex tooth 16.7 -8.4 a2 c. ibex tooth 15.2 -10.2 a3 c. ibex bone 17.0 -8.1 a3 c. ibex tooth 17.8 -7.2 a3 bos/bison sp. tooth 15.1 -9.7 a4 c. elaphus bone 16.5 -8.1 a5+6 c. ibex bone 16.5 -8.6 a5+6 c. ibex tooth 17.4 -7.7 a5+6 c. elaphus bone 16.3 -8.2 a5+6 c. elaphus bone 16.9 -7.7 a6 c. ibex bone 16.8 -8.3 a6 c. capreolus bone 17.9 -7.1 a6 c. capreolus bone 17.7 -7.3 a7 bos/bison sp. bone 15.0 -9.8 a10 c. ibex bone 18.4 -6.5 a10 bos/bison sp. tooth 14.2 -10.6 a11 bos/bison sp. tooth 15.1 -9.7 a11 bos/bison sp. tooth 16.2 -8.7 br1 c. ibex bone 17.6 -7.4 br1 c. elaphus bone 17.7 -7.0 br3 c. ibex bone 16.8 -8.3 br4 c. ibex bone 17.4 -7.7 br5 c. ibex bone 17.0 -8.1 br5 c. elaphus bone 16.8 -7.8 br5 c. elaphus bone 17.5 -7.2 br6 c. elaphus bone 17.1 -7.5 br6 c. capreolus bone 16.7 -8.4 br7b c. elaphus bone 17.4 -7.3 br7b c. elaphus bone 17.2 -7.4 br7b c. elaphus bone 16.1 -8.4 lleevveell ssppeecciimmeenn sskkeelleettaall δδ 1188oo pp δδ 1188oo ww rreemmaaiinnss br7c c. elaphus bone 17.4 -7.3 br7f c. elaphus bone 17.6 -7.0 br7f c. elaphus bone 17.7 -6.9 br7f c. capreolus bone 16.7 -9.2 br7f c. capreolus bone 15.9 -9.3 br8 c. ibex bone 17.2 -7.8 br8 c. elaphus bone 17.3 -7.3 br9 c. ibex bone 16.9 -8.2 br9 c. elaphus bone 18.5 -6.2 br9 c. elaphus bone 17.1 -7.5 br9 c. elaphus tooth 16.5 -8.1 br9 c. capreolus bone 16.6 -8.5 br10 c. ibex bone 17.5 -7.5 br10 c. ibex tooth 12.4 -13.4 br10 c. ibex tooth 18.0 -7.0 br11d c. ibex tooth 15.9 -9.3 br11d c. elaphus bone 17.0 -7.7 br11d c. elaphus bone 17.6 -7.0 br11d c. elaphus bone 15.9 -8.6 br11d c. capreolus bone 17.3 -7.8 br11d c. capreolus bone 17.7 -7.3 br12 c. elaphus bone 16.6 -8.0 br12 c. elaphus bone 17.8 -6.9 br12 c. elaphus bone 17.4 -7.3 br12 c. elaphus tooth 16.1 -9.1 br12 c. capreolus tooth 14.2 -11.3 br12 c. capreolus bone 15.7 -9.6 s2 c. elaphus bone 16.5 -8.0 s2 c. elaphus bone 17.1 -7.5 s2 c. elaphus bone 17.0 -7.6 s2 c. ibex tooth 14.9 -10.5 s2 c. ibex tooth 14.8 -10.6 s2 c. capreolus bone 17.5 -7.6 s2 c. capreolus bone 17.9 -7.0 s2 c. capreolus bone 17.6 -7.4 s3 c. elaphus bone 16.8 -7.7 s3 c. elaphus bone 16.9 -7.7 s3 c. elaphus bone 16.1 -8.4 s3 c. elaphus bone 17.3 -7.3 s3 c. ibex tooth 14.8 -10.6 s3 c. ibex tooth 14.3 -11.1 s4 c. elaphus bone 17.0 -7.6 s4 c. elaphus bone 16.3 -8.2 s4 c. elaphus bone 16.8 -7.7 s4 c. ibex tooth 12.5 -13.2 s4 c. capreolus bone 18.4 -6.5 s5 c. elaphus bone 15.3 -9.1 s5 c. elaphus bone 16.3 -8.2 s5 c. ibex tooth 14.8 -10.6 s6 c. elaphus bone 16.0 -8.5 s6 c. elaphus bone 17.4 -7.2 s6 c. elaphus bone 17.0 -7.6 s7 c. elaphus bone 17.2 -7.4 s8 c. elaphus bone 16.5 -8.0 s8 c. elaphus bone 16.8 -7.7 s8 c. elaphus bone 17.8 -6.9 s8 c. elaphus bone 14.1 -10.2 s9 c. elaphus bone 16.8 -7.7 s9 c. elaphus bone 14.4 -9.9 tab.1 δ18op of the samples measured, their stratigraphic position and calculated δ18ow values. valori di δ18op dei campioni misurati, la loro posizione stratigrafica e i valori calcolati di δ18ow. 42 tooth values and the uncertainty on the meaning of the observed difference, teeth were not used for the reconstruction of the palaeoclimatic curve. apart from a few cases the δ18ow values calculated from the δ18op of c. ibex, c. capreolus, c. elaphus and bos/bison sp. bone samples are rather similar along the stratigraphic sequence (fig.3). the observed similarity suggests similar δ18o values for the water taken in by the specimens of the different species despite their different behaviour. if the mean δ18ow values of all the samples measured are taken into consideration the solid curve can be traced through the sequence (fig.3). this curve is characterised by very small δ18ow oscillations and does not show a significant trend, most of the samples yielding results that are not very far from modern mean values of atmospheric precipitation and of environmental water in that area (about -7.5 / -8.0 per mil). this consideration is not acceptable since the time interval considered is known as a cold period belonging to the last glacial. to explain this apparent inconsistency in the results it must be assumed that during glacial periods the isotope composition of ocean water was considerably enriched in heavy isotopes (18o and d) when compared to modern ocean water (shackleton and kenneth, 1975). this enrichment is related to the storage of huge amounts of isotopically light water in the thick and expanded ice caps covering large areas of the northern hemisphere. since the mediterranean basin is known to amplify the climatic effects considerably, it can be assumed that, during the last glacial period, oceanic water was at least 1 to 1.5 per mil heavier than now and the mediterranean water was, very likely, heavier by 1.5 to 2 per mil than now. accordingly, the oxygen isotope composition of the atmospheric water vapour and the atmospheric precipitation were 18o enriched by about the same amount. this means that the mean δ18ow value obtained from most of the samples measured should be shifted by about 2 per mil towards lighter (colder) values. such a shift corresponds to a temperature decrease of about 5°c that can be reasonably accepted to represent the mean difference between the average conditions of the last glacial in this area and modern conditions. if the most negative values obtained are taken into account the δ18ow obtained from levels s8 and d1a are lighter than the modern mean isotope composition of local meteoric water by about 2/2.5 per mil. on the basis of the modern mediterranean temperature gradient (0.39 per mil) the difference between the modern value and the lowest results obtained would correspond to a negative gradient in the yearly mean air temperature of about 9.0/11.0°c if the variation of 1.5/2 per mil of the oxygen isotope composition of the mediterranean water is taken into account. these values seem to be too high and in this case it is worth suggesting once more the possibility that these very negative values may be related to specimens that drank stream water from alpine glaciers or, at least, from high mountains. it is also possible that, given the incompleteness of our curve, the coldest periods are not documented because the cave was not occupied. davanzo-iacumin-longinellii fig.2 oxygen isotope composition of palaeoenvironmental waters calculated from the measured δ18op values reported according to the stratigraphic position of the samples. solid symbols are bones, open symbols are teeth. valori di δ18o dell’acqua paleoambientale, calcolati dai valori di δ18op dei diversi campioni riportati in funzione della loro posizione stratigrafica. i simboli pieni si riferiscono a campioni di ossa, gli altri a campioni di denti. 43 44.. ccoonncclluussiioonnss the reported stable isotope study suggests that: when possible, it is better to avoid the use of fossil teeth for palaeoenvironmental reconstruction along a stratigraphic sequence because they record the conditions existing during a short period of the individual’s life. this short period can be “isotopically” different in comparison to their overall life; the studied samples recorded the climatic conditions during a period considerably colder than the present one with colder climatic episodes; the temperature gradient between the studied period and recent time was not lower than about 5°c, with, probably, considerably colder episodes; these results are of importance as database of the oxygen isotope composition of mammal skeletal remains of palaeolithic age. by comparing all the samples from europe, measured up to now, these new data may help the detailed reconstruction of the impact of each climatic event along ns and ew geographic sections. rreeffeerreenncceess ayliffe l.k., chivas a.r. leakey m.g. – 1994. the retention primary oxygen isotope composition of fossil elephant skeletal phosphate. geochim., cosmochim. acta, 5588, 5291-5298. bartolomei g., broglio a., cassoli p., castelletti l., cremaschi m., giacobini g., malerba g., maspero a., peresani m., sartorelli a. and tagliacozzo a. –1992a. la grotte-abri de fumane. un site aurignacien au sud des alpes. preistoria alpina, museo tridentino di scienze naturali, 2288, 131179. bartolomei g., broglio a., cassoli p., cremaschi m., giacobini g., malerba g., maspero a., peresani m. and tagliacozzo a. 1992b. risultati preliminari delle nuove ricerche al riparo di fumane. annuario storico della valpolicella, 9-64. bryant j.d., froelich p.n., showers w.j. and genna b.j. – 1996. biologic and climatic signals in the oxygen isotopic composition of eocene-oligocene equid enamel phosphate. palaeogeogr., palaeoclimatol., palaeoecol., 112266, 75-89. cassoli p. and tagliacozzo a., 1994. considerazioni paleontologiche, paleoecologiche e archeozologiche sui mammiferi e gli uccelli dei livelli del pleistocene superiore del riparo di fumane (vr) scavi 1988-1991. bollettino museo civico storia naturale verona, 1188, 349-445. cremaschi m., ferrarsi m.r., scola v. and sartorelli a., 1986. note preliminari sul deposito pleistocenico del riparo di fumane (verona). bollettino museo civico storia naturale verona, 1133, 535-567. crowson r.a. & showers w.j. (1991). preparation of phosphate samples for oxygen isotope analysis. analytical chemistry 6633, 2397-2400. mammal skeletal remains ... fig.3 oxygen isotope composition of palaeoenvironmental waters calculated from the δ18op of bone samples reported according to the stratigraphic position of the samples. the curve suggests the possible trend of the “mean” climatic conditions. valori di δ18o dell’acqua paleoambientale, calcolati dai valori di δ18op delle ossa riportati in funzione della posizione stratigrafica. la curva è l’unione dei punti che rappresentano il valore medio dei campioni di ossa presenti nel medesimo strato ed indica il possibile andamento climatico. 44 d’angela d. & longinelli a. (1990). oxygen isotopes in living mammals’ bone phosphate: further results. chemical geology (isotope geoscience section) 8866, 75-82. delgado huertas a., iacumin p., stenni b., sanchez chillon b. & longinelli a. (1995). oxygen isotope variations in mammalian bone and tooth enamel. geochimica et cosmochimica acta 5599, 42994305. fricke h.c. and o’neil j.r., 1996. interand intratooth variation in the oxygen isotope composition of mammalian tooth enamel: some implication for paleoclimatological and paleobiological research. palaeogeogr., palaeoclimatol., palaeoecol., 112266, 91-99. lécuyer c., grandjean p., o’neil . j.r., cappetta h & martineau f. (1993). thermal excursions in the ocean at the cretaceous-tertiary boundary (northern marocco): δ18o record of phosphatic fish debris. palaeogeography, palaeoclimatology, palaeoecology 110055, 235-243. longinelli a. (1984). oxygen isotopes in mammal bone phosphate: a new tool for paleohydrological and paleoclimatological research? geochimica et cosmochimica acta 4488, 385-390. longinelli a. (1995). stable isotope ratios in phosphate from mammal bone and tooth as climatic indicators. in: b. frenzel ed., proceedings of the esf workshop, bern 1993, palaeoklimaforschung bd 15, special issue: 57-70. luz b., kolodny y. and horowitz m., 1984. fractionation of oxygen isotopes between mammalian bone phosphate and environmental drinking water. geochim., cosmochim. acta, 4488, 1689-1693. peresani m. and sartorelli a., 1996. the lithic assemblages at the cave of fumane. new evidence of technological variability in the middle palaeolithic of northern italy. xiii u.i.s.p.p. congress proceedings forli 8-14 novembre 1996 ed. a.b.a.c.o., 22, 269-278. shackleton n.j. and kenneth j.p., 1975. palaeotemperature history of the cenozoic and the initiation of the antarctic glaciation: oxygen and carbon isotope analyses. in: dsdp sites 277, 279 and 281: kenneth et al., (edrs.). initial reports of the dsdp, 29. us gov. print. office, 743-755. davanzo-iacumin-longinellii ms. ricevuto il 31 ottobre 2001 testo definitivo ricevuto il 19 dicembre 2001 ms. received: october 31, 2001 final text received: december 31, 2001 sess 1_160211.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 detecting and modeling active structures in northern calabria: new insights from drainage network morphometric analysis. enrico santoro1, luigi ferranti2, carmelo monaco1, frank j. pazzaglia3 & pierfrancesco burrato4 1dipartimento di scienze geologiche, università di catania, catania 2dipartimento di scienze della terra, università “federico ii”, napoli 3department of earth and environmental science, lehigh university, bethlehem (pa) 4sezione di sismologia e tettonofisica, i.n.g.v., roma corresponding author: e. santoro <enrico.santoro@hotmail.it> abstract: santoro e. et al., detecting and modeling active structures in northern calabria: new insights from drainage network morphometric analysis.(it issn 0394-3356, 2011). a detailed morphometric analysis of the drainage network on the eastern side of the pollino mountain range (northeastern calabria) was performed in order to gain new insights on the active tectonic frame, the landscape evolution state and the response time of the hydrographic network to the tectonic deformations. riassunto: santoro e. et al., individuazione e modellazione di strutture attive in calabria settentrionale: nuove evidenze dall’analisi morfometrica del reticolo idrografico. (it issn 0394-3356, 2011). un’analisi morfometrica di dettaglio delle principali fiumare che drenano il versante orientale del pollino (calabria nordorientale) ha consentito di acquisire nuove conoscenze riguardo il quadro tettonico attivo, lo stato evolutivo del paesaggio e i tempi di risposta del sistema idrografico alle deformazioni imposte dalla tettonica. key words: morphometric analysis, knickpoints, active transpression, north-eastern calabria. parole chiave: analisi morfometrica, convessità, transpressione attiva, calabria nord-orientale.  the longitudinal profile of bedrock channels may yield valuable information about the landscape vertical deformation processes, the rock mass erosional strength, the eustatic cycles and the climatic factors controlling the landforms. a number of studies have been successful in the evaluation of recent deformation features using quantitative analysis of longitudinal profiles (e.g., merritts & vincent, 1989); the realization of this goal, however, remain limited to the areas were local calibration of model parameters is possible (kirby & whipple, 2001). in this study, inspired by previous results obtained through the mapping of the marine terraces and the reconstruction of the relative paleo-shorelines, we have performed a detailed morphometric analysis of the drainage network on the eastern side of the pollino mountain range (north-eastern calabria; fig. 1). the uniform coastal lithology and climate allow us to isolate the tectonic signal from the fluvial morphometric analysis. this region is located on the north-eastern tip of the calabrian arc, which lies above the westerlyplunging ionian slab, and a combination of lithospheric and crustal processes concurred to rapid late quaternary uplift. ferranti et al. (2009) and santoro et al. (2009) mapped ten terrace orders up to 663 m a.s.l., correlated between the coastal slopes of pollino range across the sibari plain, facing the ionian sea side of north-eastern calabria and eastern basilicata. based on the terrace chronology, uplift along the pollino coastal range, in the last ~600 ka, occurred at an average rate of 1 mm/a, but was characterized by the alternation of more rapid (~2.2 mm/a) and slower (~0.7 mm/a) periods of displacement. besides, spatial variability in uplift rates is recorded by the deformation profile of terraces parallel to the coast, which document small-wavelength (~20 km) and amplitude (up to ~100 m) local undulations superposed to the regional uplift pattern, which is the dominant tectonic signal (santoro et al., 2009). based on the structural, geodetic, geophysical and seismic data the paleo-shorelines undulations were interpreted as fault-propagation folds linked to the transpressive shear zones, no-se directed, that affected the region since the early pleistocene. this hypothesis is confirmed by the results of the numeric modelling of the shear zones cutting the coastal area where the major deformations were identified. the good match between the modelled vertical co-seismic deformation and the paleoshorelines deformation profiles testifies that the transpressional regime was active during the middle-upper pleistocene. through an iterative comparison between the paleo-shoreline profiles and the vertical co-seismic deformation it was possible to define the geometric and kinematic fault parameters that best explain the marine terraces deformation. the final deformation model predicts the active uplift of two anticlines along the southeastern flank of the pollino range and the valsinni 60 62 61 ridge (hereafter named pollino and valsinni anticlines, respectively; fig. 1). the morphometric analysis was performed to test and improve the above mentioned deformation model. linear regressions of the logarithms of channel gradient and drainage area data was used to find convexities (knickpoints) and to determine, the concavity index (θ) and the steepness index (ks). the method is based on the shear-stress incision model, predicated on the hypothesis that the bedrock-channel-erosion rate (e), in volume per unit channel area, is a power-law function of basal shear stress (τb): e = kbτb a, (1) where kb is a dimensional coefficient dependent on dominant erosion process, rock resistance and sediment load and a is a positive, processdependent constant. combining the shear-stress incision model with a statement of conservation of mass, assuming that uplift and erosion are uniform in a drainage basin and solving for the river longitudinal slope is possible to write: s = ksa-θ. (2) the coefficient ks (steepness index) and the exponent θ (concavity index) are, respectively, the gradient-axis-intercept and the slope of the linear regressions through the logarithms of channel gradient and drainage area data. we limited our analysis to the bedrock channel region; the results obtained from area controlled by hillslope/colluvial or alluvial processes are, indeed, not reliable. the rivers longitudinal profiles, extracted from dem 10x10 m, were corrected averaging the elevation through a mobile 200 m window, in order to reduce the gradient data dispersion derived by dem errors. following snyder et al. (2000) and whipple (2004) we used a fixed reference concavity (θ = 0.45) in order to calculate a normalized steepness index (ksn); this permitted the comparison between channels characterized by different drainage areas (e.g., kirby et al., 2003). the ksn values increase regularly toward the pollino and valsinni anticlines; in other words, the rivers flowing through the areas that are affected by the higher uplift rates tend to establish a steeper longitudinal profile in order to have the energy sufficient to erode the uplifting tectonic barrier. several knickpoints (steeper channel segments characterized by convexupward shapes and θ<0) were detected along the longitudinal profiles of the trunk streams. being the analyzed rivers adjusted to the sea level (drainage network base level), it is reasonable to hypothesize that some of the knickpoints are related to the glacialinterglacial quaternary cycles. to test this idea, for each knickpoint the reconstruction of the interglacial profile was performed through the ks and the θ values calculated for the respective river. an eustatic origin was considered valid if: 1. the paleolongitudinal profile crosses a marine terrace; 2. at least three knickpoints are related to the same marine terrace (same eustatic regression); 3. the knickpoints correlated to the same eustatic cycle are characterized by migration rates and positions that are in direct relationship with the landward drainage area. for some of the knickpoints the eustatic origin is confirmed by the presence of fluvial terraces aligned with the relative paleolongitudinal profiles; the terraces are, reasonably, the consequence of the erosive wave triggered by the eustatic regression and progressively transmitted to the entire drainage basin through the knickpoint landward migration. generally, the elevation of a knickpoint genetically related to an eustatic sea level regression is influenced by the drainage fig. 1, knickpoints elevation and incision rates compared with the deformation model. altezze dei knickpoints e tassi di incisione fluviali comparati con il modello di deformazione.  detecting and modeling active structures in northern ... 62 ms. received: testo ricevuto il area (migration rate) and the trunk stream longitudinal gradient. as a consequence, holding constant the drainage area the knickpoint elevation can be influenced by gradient changes determined .by differential uplift rates; the higher the uplift rate the higher the gradient and the knickpoint elevation. in the study area this theoretical prediction is perfectly confirmed: all the knickpoints related to the same marine terrace are always characterized by an increase of the elevations toward the pollino and valsinni anticlines (fig. 1) where the higher uplift rates determine a rise of the river gradients. the maximum difference in elevation between the paleo-longitudinal profiles and the present riverbed was evaluated in order to determine the mean fluvial incision rates. as forecasted by the deformation model, the rivers flowing through the pollino and valsinni anticlines are characterized by the higher incision rates (fig. 1). these streams, in order to adjust their equilibrium profile disturbed by the tectonic deformation, increase their gradient and vertically incise through their valley. finally, based on the migration rates, it was possible to determine the drainage network response time considered to be the time necessary for a convexity to migrate through the entire drainage basin. all the analyzed rivers show a low response time (~105 yr) that highlights the youthfulness of the tectonic deformation; indeed, all the tectonic signals older than 105 yr can be considered completely erased by the fluvial erosive processes. the longitudinal profile analysis have permitted to confirm the results independently reached with the marine terraces, the structural and geophysical analysis and the fault modelling, evidencing that compressional regime is still active in this sector of the southern apennines. references ferranti l., santoro e., mazzella m.e., monaco c. & morelli d. (2009) active transpression in the northern calabria apennines, southern italy. tectonophysics, 476 (1-2), 226-251. kirby e., whipple k.x., tang w. & zhiliang c. (2003) – distribution of active rock uplift along the eastern margin of the tibetan plateau: inferences from bedrock channel longitudinal profiles. j. geophys. res., 108 (b4), 2217, doi: 10.1029/2001jb000861. kirby e. & whipple k. (2001) – quantifying differential rock-uplift rates via stream profile analysis. geology, 29 (5), 415-418. merritts d. & vincent k.r. (1989) – geomorphic response of coastal streams to low, intermediate and high rates of uplift, mendocino triple junction region, northern california. geol. soc. am. bull., 101, 13731388. santoro e., mazzella m.e., ferranti l., randisi a., napolitano e., rittner s. & radtke u. (2009) raised coastal terraces along the ionian sea coast of northern calabria, italy, suggest space and time variability of tectonic uplift rates. quaternary international, 206, 78-101. snyder n.p., whipple k.x., tucker g.e. & merritts d.j. (2000) – landscape response to tectonic forcing: digital elevation model analysis of stream profiles in mendocino triple junction region, northern california. geol. soc. am. bull., 112, 1250-1263. whipple k.x. (2004) – bedrock rivers and the geomorphology of active orogens. ann. rev. earth planet sci., 32, 151-185. january 13, 2011 13 gennaio 2011 e. santoro et al. sess 1_160211.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 evidence of coseismic deformation in the taormina region (northeast sicily): new data from the capo schisò area. cecilia rita spampinato1, giovanni scicchitano1, luigi ferranti2, carmelo monaco1 & fabrizio antonioli3 1 dipartimento di scienze geologiche, università di catania 2 dipartimento di scienze della terra, università federico ii, napoli 3 enea casaccia, roma corresponding author: c. r spampinato <ceciliaspampinato@hotmail.it> abstract: spampinato c.r. et al., evidence of coseismic deformation in the taormina region (northeast sicily): new data from the capo schisò area. (it issn 0394-3356, 2011) in this paper the results of a detailed mapping of geological and archaeological indicators of raised holocene shorelines, around capo schisò volcanic headland a few kilometers south of taormina (north-eastern sicily), are discussed. the detailed survey of the promontory of capo schisò has confirmed the existence of three paleoshorelines at different altitudes. the shoreline1 is represented by a fossiliferous beach deposit, which is heavily eroded and only few small sections, about 40 cm thick, at elevation ranging between ~3 and ~5 m, are visible. the shoreline2 was found a max altitude of ~2.90 m and is represented by algal rims, remnants of barnacle bands and serpulid concretions and by a fossiliferous beach deposit. the shoreline3 includes remnants of algal rims, serpulid concretions, remnants of fossil barnacle bands and a beachrock and reaches an elevation of ~1.60 1.80 m a.s.l. new radiocarbon dating results, compared with published data suggest an average uplift rate of 1.7-1.8 mm/yr and the occurrence of three co-seismic uplift events in the last 5 ka (~4.0, ~2.0 and ≤1.0 ka ago). abrupt displacements are attributed to co and post-seismic footwall uplift along the offshore taormina normal fault. riassunto: spampinato c.r. et al., evidenze di deformazione cosismica nella regione di taormina (sicilia nord orientale): nuovi dati dall’area di capo schisò. (it issn 0394-3356, 2011) in questo lavoro, sono discussi i risultati di un dettagliato rilievo degli indicatori geologici e archeologici delle linee di costa oloceniche sollevate a capo schisò, un promontorio vulcanico pochi chilometri a sud di taormina,. l'indagine dettagliata del promontorio di capo schisò (sicilia nord-orientale) ha confermato l'esistenza di tre paleo-linee di costa a diverse quote. la paleo-linea 1 è rappresentata da un deposito fossilifero di spiaggia, il quale è fortemente eroso e solo poche sezioni, con spessori di circa 40 cm, sono state trovate ad altitudini comprese tra 3 e ~5 m. paleo-linea 2 è stata trovata ad una quota massima di circa 2,90 m ed è rappresentata da: rim algali, resti di fasce di balanidi, concrezioni di serpulidi e da un deposito fossilifero di spiaggia. la paleo-linea 3 comprende resti di rim algali, concrezioni di serpulidi, resti di fasce di balanidi fossili e una beach rock, e raggiunge un'altezza di circa 1,60-1,80 m s.l.m. le nuove datazioni al radiocarbonio, confrontate con i dati pubblicati, suggeriscono un tasso medio di sollevamento di 1,7-1,8 mm / anno e il verificarsi di tre eventi di sollevamento co-sismico negli ultimi 5 ka (~ 4 ~ 2 e ≤ 1 ka fa). spostamenti bruschi sono attribuiti al sollevamento coe post-sismico lungo la faglia normale di taormina, ubicata lungo l’offshore. key words: tectonic uplift, coseismic deformation, eastern sicily. parole chiave: sollevamento tettonico, deformazione cosismica, sicilia orientale. 1. introduction southern italy represents one of the major seismogenic areas of the mediterranean region and is characterized by the recurrence of several historical earthquakes (boschi et al., 1995, 1997). an anomaly in the regional seismotectonic frame is represented by the ionian coast of the northeastern sicily, located on the footwall of the offshore taormina fault (scandone et al., 1996; stewart et al., 1997; monaco & tortorici, 2000; catalano & de guidi, 2003) that, despite showing a strong tectonic uplift during the late quaternary, is affected by very low to absent historical seismicity. previous studies on morphological and biological sea level markers document that the coastal sector between taormina and capo s’alessio (fig. 1) has been uplifted also during late holocene and short-term uplift-rate estimates are provided by raised holocene beaches and tidal notches (stewart et al., 1997; rust & kershaw, 2000; de guidi et al., 2003; antonioli et al., 2003; 2006). in order to evaluate vertical tectonic movements in the studied area, during late holocene, we compared age and elevation of published and new data together with predicted holocene sea level curve (lambeck et al., 2010) which takes into account eustatic and glacio-hydroisostatic factors. the final goal of this work is to evaluate the 66 68 67 regional and local contribution to deformation, pointing out relations with the displacement along active normal faults. 2. uplifted holocene shorelines capo schisò is a volcanic promontory located about 3 km southward taormina (fig. 1). the lava substrate is not ideal for the conservation of sealevel markers, however the presence of lava headland along a low sandy-gravelly coast was useful to identify sea-level markers confirming the presence of three raised ancient shorelines. at this site we mapped a higher fossiliferous beach deposit close to the top of the headland (the shoreline 1). the fossiliferous beach deposit is heavily eroded and only few small sections, about 40 cm thick, at elevation ranging between ~3 and ~5 m, are visible. sedimentary features and faunal content suggest that no change in depositional conditions occurred during the time of its development, which occurred in an infralittoral beach environment. we correlated this fossiliferous beach deposit to the highest shoreline located along the coast between st. alessio and taormina (fig. 1), represented by a notch developed at an altitude of ~5 m a.s.l. the shoreline 2 is represented by: i) algal rim probably representing an ancient troittor, that has been found along all the coast of the headland at an altitude of ~2.90 m a.s.l.; ii) serpulid concretions that have been found at elevation of ~2.80 m; iii) fossil balanids, that have been found at an elevation of ~3.0 m, marking the maximum height of this palaeo-shoreline; iv) fossiliferous beach deposit, with base located at ~0.30 m and the top at altitude of ~2.40 m a.s.l. the shoreline 3 includes: i) remnants of algal rims, that have been found at an altitude ranging between ~1.60 m and 1.80 m a.s.l; ii) serpulid concretions, that associated to the algal rims, were found at 1.50-1.80 m elevation; iii) residue of fossil barnacle rims that were found above the algal rims at an elevation of ~2.0 m, marking the maximum height of this palaeo-shoreline; iv) beach rock outcrops, that form a sedimentary body whose bottom reaches -1.0 m depth and the top at 1 m height. serpulid encrusting the beach rock was sampled at an altitude of 0.70 m. the archaeological site of naxos (fig. 1) represent the most ancient settlement of all the greek colonies in sicily. at a distance of ~160 m from the modern coastline, covered slipways of classic greek period (2.4 ka) have been discovered (blackman, 1968; blackman & lentini, 2003). they represent a good palaeo-sea level marker (auriemma & solinas, 2009). in order to calculate the marker elevation, we used the topographic survey carried out during the excavation process (blackman & lentini, 2007). taking into account the points listed in the topographic survey, we rebuilt the entire dry part of the best preserved slipway the obtained marker elevation is 1.4 m a.s.l. taking into account a functional height for the ancient greek slipway of -1.0 m, it is possible to reconstruct a palaeo-sea level of 2.4 m above present sea level. comparing elevation and age with the curve of the predicted sea level rise of lambeck et al., (2010), an uplift rate of ~1.72 mm/ yr for the last 2.4 ka can be estimated. 3. late holocene uplifts in order to estimate the total vertical displacement during the late holocene at capo schisò, data presented in this study have been integrated with published data (stewart et al., 1997; antonioli et al. 2003; 2006; branca et al., 2003). moreover, the elevation-age data have been compared to the local curve of holocene sea-level rise (lambeck et al., 2010). samples from the shoreline 1 have provided an uplift rate of 2.07±0.19 mm/y at st. alessio, of 1.78±0.29 mm/y at taormina and 1.95±0.08 mm/yr at capo schisò. samples from the shoreline 2, suggest uplift rates ranging between ~1.74±0.19 mm/yr at taormina and 1.60±0.11 mm/y at capo schisò (e.g. the algal rim). dendropoma shells collected at taormina suggest an uplift rate of 1.67±0.11 mm/y for the shoreline 3. for the same shoreline, a serpulid fig. 1sketch map of taormina region with locations of investigated holocene sites. mappa della regione di taormina con la localizzazione dei siti olocenici investigati. evidence of coseismic deformation in the taormina ... 68 ms. received: testo ricevuto il sampled at capo schisò provides an uplift rate of 1.75±0.51 mm/y. 4. conclusion the occurrence of three distinct shorelines and their abrupt temporal superposition indicate quasiinstantaneous uplifts, that are probably related to coseismic displacements (see also de guidi et al., 2003). the radiometric results showed that the shoreline1 was active between ~6.4 ka and ~4.4 ka cal bp before being abruptly isolated above the sea by a coseismic event (event i) between ~4.4 and ~4.0 ka bp. the magnitude of vertical displacement occurred during this event is determined from the difference in nominal elevation between the shoreline 1 and shoreline 2 and varies between 1.8 at capo schisò and 1.6 at taormina. considering the large uncertainty of taormina data, the two sites could have been characterized by the same magnitude of vertical displacement. the shoreline 2 has been active for a time span of ~2 ka between ~4.0 and ~2.1 ka bp. then, between ~2.1 and ~1.8 ka bp the shoreline 2 was raised by sudden tectonic displacement (event ii), as constrained by cessation of the shoreline 2 and simultaneous development of the shoreline 3. the amount of vertical displacement is yielded by the difference of nominal elevation between shoreline 2 and shoreline 3 and, considering the large uncertainty, it is consistently of ~1.10 m both at taormina and at capo schisò. the radiometric results show that the shoreline 3 was active for a time interval ranging between ~1.8 and ~1.0 ka bp and after ~1.0 ka it was raised abruptly from a third (~1.20 m) co-seismic event. in conclusion our study documents three palaeoearthquakes probably occurred in the last 4.0 ka with coastal displacement related to the activity of the offshore taormina fault. references antonioli f., kershaw s., rust d. & verrubbi v. (2003) – holocene sea-level change in sicily an its implications for tectonic models: new data from the taormina area, northeast sicily. marine geology, 196, 53-71. antonioli f. et al., (2003) – late pleistocene to holocene record of chancing uplift rates in southern calabria and northeastern sicily (southern italy, central mediterranean sea). tectonophysics , 422, 23-40. auriemma r. & solinas e. (2009) archaeological remains as sea level change markers: a review. quaternary int., 206, 134-146. blackman d. j. (1968) – the shipsheds in morrison, j. s. & williams, r. t., greek oared ships. cambridge 181-192. blackman d. j. & lentini m. c. (2003) – the shipsheds of sicilian naxos: researches 19982001. a preliminary report. rsa 98. blackman d. j. & lentini m. c. (2007) graffiti from the dockyard of sicilian naxos. 13th international congress of greek and latin epigraphy, oxford. boschi e. et al. (1995) – catalogo dei forti terremoti in italia dal 461 a.c. al 1980. istituto nazionale di geofisica, s.g.a., roma. boschi e. et al. (1997) – catalogo dei forti terremoti in italia dal 461 a.c. al 1990. istituto nazionale di geofisica, s.g.a., roma. branca s. (2003) geological and geomorphological evolution of the etna volcano ne flank and relationships between lava flow invasions and erosional processes in the alcantara valley (italy). geomorphology, 53, 247-261. catalano s. & de guidi g. (2003) – late quaternary uplift of northeastern sicily: relation with the active normal faulting. journal of geodynamics, 36, 445-467. de guidi g., catalano s., monaco c. & tortorici l. (2003) – morphological evidences of holocene coseismic deformation in the taormina area (ne sicily). journal of geodynamics, 36, 193-211. lambeck k. et al. (2010) sea level change along italian coast during holocene and a prediction for the future. quaternary int., in press monaco c. & tortorici l. (2000) – active faulting in the calabrian arc and eastern sicily. journal of geodynamics, 29, 407 424. rust d. & kershaw s. (2000) holocene tectonic uplift patterns in northeastern sicily: evidence from marine notches in coastal outcrops. marine geology, 167, 105 126. scandone p., patacca e. & meletti c. (1996) main recent deformation and seismotectonics in the central mediterranean region. workshop on: "geodynamics of the mediterranean area and implications on volcanic and seismic hazards", int. school earth and planetary science (pontignano, siena 1-4 april 1996). stewart i., cundy a., kershaw s. & firth c. (1997) – holocene coastal uplift in the taormina area, north-eastern sicily: implications for the southern prolongation of the calabrian seismogenic belt. journal of geodynamics, 24, 37 50. c.r. spampinato et al. january 13, 2011 13 gennaio 2011 imp.cucci_tertulliani i terrazzi marini nell’area di capo vaticano (arco calabro): solo un record di sollevamento regionale o anche di deformazione cosismica? luigi cucci & andrea tertulliani istituto nazionale di geofisica e vulcanologia, sezione sismologia e tettonofisica, via di vigna murata, 605 – 00143 roma e-mail: cucci@ingv.it, tertul@ingv.it riassunto: cucci l. & tertulliani a., i terrazzi marini nell’area di capo vaticano (arco calabro): solo un record di sollevamento regionale o anche di deformazione cosismica? (it issn 0394-3356, 2006). in questo lavoro presentiamo uno studio di dettaglio dei terrazzi nell’area di capo vaticano (calabria tirrenica), insieme ad una revisione del piano quotato del terremoto del 1905. il campo macrosismico rivisitato conferma che le massime intensità sono state raggiunte in un’area estesa fra vibo valentia e capo vaticano per un evento di magnitudo m=6.8±0.2; la più probabile struttura sismogenetica responsabile dell’evento è una faglia di dimensioni 36x14 km e direzione 80° (faglia “macrosismica”). lo studio dei terrazzi ha invece messo in evidenza che l’area in studio è in sollevamento attivo da almeno 700.000 anni, che tale processo è in lieve ma progressivo aumento nel tempo, con tassi negli ultimi 124.000 leggermente inferiori a ~1 mm/anno, e che a settentrione di capo vaticano i terrazzi sono chiaramente tiltati verso nord. inoltre, le variazioni di quota osservate nelle paleolinee di riva a cavallo di una struttura tettonica ad andamento ono-ese indicano che tale struttura (faglia “geologica”) è attiva da almeno 330.000 anni, con tassi verticali medi che variano negli ultimi 215.000 anni fra 0,12 e 0,16 mm/anno. per verificare quanto ognuna di queste due strutture fosse congruente con gli elementi geologici, topografici e macrosismici a disposizione, abbiamo calcolato il campo di deformazione indotto in superficie dall’azione della faglia “macrosismica” rispetto a quello della faglia “geologica”. il confronto qualitativo fra le deformazioni aspettate evidenzia una buona congruenza nella risposta della faglia “geologica” e rafforza l’ipotesi che a tale struttura possa essere associato l’evento del 1905, anche alla luce di recenti localizzazioni ipocentrali ottenute da inversione di registrazioni storiche. abstract: cucci l. & tertulliani a., the marine terraces in the area of capo vaticano (calabrian arc): only a record of regional uplift or even of coseismic deformation? (it issn 0394-3356, 2006). the area of capo vaticano in western calabria displays a well-developed suite of marine terraces. this same region was hit in 1905 by one of the strongest – and still poorly cleared – earthquakes of the instrumental era. our revision of the intensity map of the event confirms the location of the most damaged area (between vibo valentia and capo vaticano) and indicates that the most likely source is a n80°-trending, 36(l) x 14(w) km structure with a macroseismic magnitude m=6.8±0.2. a detailed study of the marine terraces shows that sustained uplift has been the long-term dominant process of tectonic deformation in this area over the past 700 kyr, with an average long-term uplift rate slightly less than 1.0 mm/yr, and that terraces are tilted northward. moreover, the four lowest paleoshorelines are displaced by a wnw-ese trending fault, that indicates that the fault is active in the last 215,000 years with mean vertical slip rates of 0.12-0.16 mm/yr. finally, we perform a qualitative comparison between the set of geological, topographic and macroseismic data available and the expected deformation fileds induced by each of the afore-mentioned faults. it is therefore suggested that the good response of the wnw-trending fault strenghtens the hypothesis of this structure as the source of the 1905 earthquake. parole chiave: terrazzi marini – arco calabro – sismicità – capo vaticano. keywords: marine terraces – calabrian arc – seismicity – capo vaticano. il quaternario italian journal of quaternary sciences 19(1), 2006 89-101 introduzione l’area di capo vaticano nella provincia calabrese di vibo valentia fu colpita cento anni fa da uno dei più forti, ma poco chiariti, terremoti italiani del secolo passato, che produsse gravi danni in una vasta zona della calabria centrale, con massimo risentimento lungo la costa tirrenica fra lametia e nicotera. nonostante la sua energia (maw=7.1; gruppo di lavoro cpti (2004); ms=7.5 margottini et al., (1993); i=x-xi mcs), la sorgente dell’evento dell’8 settembre 1905 è ancora dibattuta, poiché gli autori hanno proposto diversi epicentri sia a mare che a terra, senza associarli in modo univoco a faglie sismogenetiche conosciute. in questa stessa area è ben visibile una notevole sequenza di terrazzi marini, che sono uno degli effetti più spettacolari del sollevamento quaternario lungo le coste dell’arco calabro. antiche linee di riva sollevate sono presenti in tutta la regione sia lungo la costa tirrenica (fuscaldo, amantea, capo vaticano), che lungo quella ionica (sibari, crotone) così come lungo le coste dello stretto di messina. in questo lavoro presentiamo uno studio di dettaglio dei terrazzi nell’area di capo vaticano, lungo un tratto di ~60 km di costa, insieme ad una revisione degli effetti del terremoto del 1905. confrontiamo quindi i dati geologici di sollevamento e deformazione locale evidenziati dai terrazzi marini con lo scenario del terremoto desunto dalle osservazioni macrosismiche, per cercare di valutare l’attività di alcune strutture tettoniche e di verificarne la compatibilità con l’evento del 1905. 90 l. cucci & a. tertulliani geologia e sismotettonica il promontorio di capo vaticano è un alto strutturale localizzato nella parte centrale dell’arco calabro, in un’area chiave per comprendere alcuni processi direttamente connessi alla subduzione di litosfera oceanica ionica nel piano di benioff del tirreno meridionale. ad esempio, il probabile detachment dello slab in subduzione (spakman et al. 1993; westaway, 1993; hyppolite et al. 1994; gvirtzmann & nur, 1999) o l’arretramento dello slab stesso (malinverno & ryan, 1986; giunchi et al. 1996; meletti et al. 2000; barberi et al. 2004) sono alternativamente proposti dagli autori come responsabili dell’estensione attiva instauratasi perpendicolarmente alla catena e del rapido sollevamento dell’italia meridionale (gignoux, 1913; bousquet, 1973; brogan et al. 1975; aïfa et al. 1988; westaway, 1993; bordoni & valensise, 1998; ferranti et al. 2006). il basamento cristallino che costituisce l’ossatura del promontorio di capo vaticano è rappresentato da graniti, gneiss e quarzofilliti, coperti da affioramenti discontinui di carbonati miocenici-pliocenici e da depositi terrigeni. in tutta l’area di studio e a diverse quote affiorano diffusamente depositi terrazzati marini pleistocenici a luoghi ricoperti da un sottile velo di sedimenti continentali recenti ed attuali. la storia quaternaria dell’area di capo vaticano ricalca dunque piuttosto fedelmente quella dell’intero arco calabro, con l’instaurarsi di un regime estensionale sin dal pliocene superiore, caratterizzato dalla presenza di numerose faglie normali sia parallele (ne-so) che perpendicolari (ono-ese) alla direzione generale dell’arco stesso (fig. 1). a partire dal pleistocene medio, i processi estensionali sono stati accompagnati da un forte sollevamento regionale, di cui i numerosi terrazzi marini sono il principale e più spettacolare effetto sul paesaggio costiero. lo schema tettonico sopra descritto per le zone in affioramento si estende probabilmente anche offshore, lungo il basamento sommerso del promontorio, come fig. 1 mappa sismotettonica dell’area di capo vaticano. la sismicità storica (quadrati neri) (217 bc–2002 ad, m≥5.5) è da cpti (gruppo di lavoro cpti, 2004); la sismicità strumentale (stelle nere) nel periodo 1981-2002 (m≤4) è da castello et al. (2004). i cerchi neri numerati da 1 a 4 indicano i diversi epicentri calcolati sulla base di dati macrosismici per l’evento del 1905 e proposti rispettivamente da 1) postpischl (1985); 2) camassi & stucchi (1997); 3) gruppo di lavoro cpti (2004), e sulla base di dati sismologici da 4) michelini et al. (2005). le strutture tettoniche principali (faglie da ‘a’ a ‘e’) sono da galadini et al. (2000), valensise & pantosti (2001), e tortorici et al. (2003). non c’è uniformità di vedute fra i vari autori sulla cinematica e/o sulla cronologia di tali strutture tettoniche. seismotectonic map of the capo vaticano area black squares indicate m≥5.5 historical earthquakes in the period 217 bc–2002 ad (gruppo di lavoro cpti, 2004) and black stars indicate (m≤4) instrumental seismicity between 1981 and 2002 (castello et al. 2004). black circles numbered 1 to 4 correspond to four different epicenters based on macroseismic data and suggested by 1) postpischl (1985); 2) camassi & stucchi (1997); 3) gruppo di lavoro cpti, (2004), and based on seismological data by 4) michelini et al. (2005). main tectonic structures (faults indicated by letters ‘a’ to ‘e’) are from galadini et al. (2000), valensise & pantosti (2001) and tortorici et al. (2003). authors do not fully agree about kinematics and chronology of these lineaments. suggerito da trincardi et al. (1987) e da argnani & trincardi (1988) sulla base di profili sismici e dati batimetrici. inoltre, chiocci & orlando (1996) descrivono terrazzi marini sommersi lungo la piattaforma continentale a 4-6 km dalla costa di briatico e vibo marina (fig. 1). l’area in studio risulta caratterizzata da una sismicità relativamente sparsa e poco frequente (fig. 1). se si eccettua il grande terremoto del 1905, per il quale vengono proposti quattro differenti epicentri a riprova della incertezza associata a tale evento, il catalogo parametrico dei terremoti italiani (cpti) riporta in zona solo un altro evento avvenuto nel 1928 (m=6, i=vii-viii) lungo il bordo meridionale del promontorio. altri terremoti storici, avvenuti fra il 1659 ed il 1783, pur avendo causato diffusi risentimenti nell’area studiata sono probabilmente ascrivibili all’attività di faglie localizzate nell’adiacente graben del mesima. similmente, la sismicità strumentale nel periodo 1981-2002 è caratterizzata da eventi isolati e di bassa magnitudo; anche in questo caso, le uniche sequenze sismiche registrate (comunque con m≤3.3) sono localizzate nella stessa area dell’evento storico del 1928. il terremoto dell’ 8 settembre 1905 il terremoto dell’ 8 settembre 1905, pur essendo uno dei più forti eventi della storia sismica italiana, resta scarsamente chiarito, soprattutto per quello che riguarda la definizione di una sorgente di riferimento. diversi furono gli studi coevi sul terremoto (i.e. baratta, 1906; mercalli, 1906; rizzo, 1907) che proposero ipotesi “sismogenetiche” legate alle conoscenze dell’epoca, mentre in tempi più recenti gli studi hanno riguardato maggiormente la distribuzione degli effetti dalla quale è stato ricavato un epicentro macrosismico (postpischl, 1985; camassi & stucchi, 1997; gruppo di lavoro cpti, 2004). l’unica magnitudo calcolata da dati strumentali conosciuta è di margottini et al., (1993) ms=7.5, mentre quella di derivazione macrosismica è maw=7.1 (gruppo di lavoro cpti, 2004). galli & bosi (2002) sono gli unici che hanno tentativamente associato un epicentro onshore dell’evento ad una struttura ben definita, la faglia di monte poro (faglia ‘e’ in fig. 1). il maremoto conseguente al terremoto è stato modellato da piatanesi & tinti (2002) su alcune faglie note in letteratura, senza risultati definitivamente attendibili. le due faglie, i cui parametri sono risultati i più vicini al modello numerico risultano quella di capo vaticano e quella di vibo valentia (faglie ‘a’ e ‘b’ in fig. 1), anche se la sorgente del maremoto, secondo gli autori andrebbe cercata più ad ovest. per raccogliere ulteriori elementi utili alla valutazione di ipotesi interpretative sulla sorgente del terremoto è stata avviata la revisione degli effetti dovuti all’evento. il piano quotato di partenza è quello presente sul cfti (boschi et al. 1995). scopo di questa parte del lavoro è stato quello di revisionare il piano quotato a partire dalle descrizioni degli effetti su fonti coeve all’evento, privilegiando i lavori tecnico-scientifici (baratta, 1906; mercalli, 1906; rizzo, 1907). in seconda istanza sono state consultate le cronache locali (cotroneo, 1906) e giornalistiche (malagodi, 1905) ed alcune storie locali (pugliese, 1996; kostner, 2002) pubblicate di recente. parte della ricerca è stata svolta sul posto al 91i terrazzi marini nell’area ... fine di recuperare materiali inediti, soprattutto di tipo iconografico e urbanistico (fig. 2). l’insieme delle informazioni raccolte, incrociato con una rilettura critica delle fonti, ha portato in diversi casi a modificare l’intensità proposta in boschi et al. (1995), soprattutto in zone maggiormente discoste dall’area più colpita, dove, per molte località, l’intensità al sito è risultata essere più contenuta. sono stati anche corretti errori di localizzazione di alcuni punti di intensità presenti in boschi et al. (1995). in particolare viene abbassata da x-xi a x l’intensità massima che viene assegnata a diverse località nell’area intorno a monteleone (attuale vibo valentia). gli effetti risultarono particolarmente distruttivi su molte piccole località site all’interno del promontorio, dove si concentrano quasi tutte le intensità più elevate. c’è da rilevare che in questa zona, diversamente che sulla costa, l’edilizia era particolarmente povera e quindi vulnerabile, come riscontrato direttamente su alcuni edifici superstiti e come già evidenziato da baratta (1906) all’epoca del terremoto. vi è inoltre da considerare la presenza di probabili effetti di sito che hanno aggravato l’impatto del terremoto, spesso in aree lontane dalla zona di massima intensità (a questo proposito vedi mercalli, 1906; mucciarelli, 2005). il riesame dei punti di intensità è stato effettuato allo scopo di poter uti l izzare l’algoritmo boxer (gasperini et al. 1999) per il calcolo di localizzazione, dimensioni e orientamento della sorgente. lo stesso codice boxer usa, per il calcolo della magnitudo momento (mw), il metodo di gasperini & ferrari (1995), basato sulla relazione di wells & coopersmith (1994) per quanto riguarda l’ipotesi sulla dimensione della rottura. entrambe le procedure necessitano di un set di dati macrosismici il più affidabile possibile. poiché in linea di massima la distribuzione delle intensità più elevate è legata alle caratteristiche della sorgente, il calcolo dei parametri di faglia è stato effettuato usando i punti con i ≥ viii-ix, pienamente in accordo con quanto suggerito da gasperini et al. (1999). il risultato (fig. 3) ci mostra una struttura 36x14 km orientata circa n80° (±21°). la soluzione pone l’epicentro del terremoto a 38.68 n – 16.03 e, con mw pari a 6.8±0.2. la soluzione epicentrale è fortemente vincolata a terra dalla distribuzione dei punti di intensità, per cui non si può in questa fase escludere che l’origine del terremoto dell’8 settembre 1905 possa essere al largo della costa di capo vaticano. i terrazzi marini i terrazzi marini, visibili fino a quote di diverse centinaia di metri sul livello del mare nell’area di capo vaticano così come in gran parte del territorio calabrese, rappresentano la testimonianza fossile di antichi episodi di abrasione marina. queste forme del paesaggio, se datate, sono indicatori molto precisi dei tassi di deformazione verticale, poiché ogni terrazzo rappresenta la traccia di un dato regionale incisa nel paesaggio durante una risalita eustatica che culmina con un highstand (alto picco eustatico interglaciale). pertanto, se si riesce a datare uno o più terrazzi all’interno di una sequenza (assumendo che ogni paleolinea di riva sia associabile ad uno dei principali highstands della curva 92 fi g. 2 in f ig ur a so no m os tr at i a lc un i e se m p i d eg li ef fe tt i d is as tr os i d el t er re m ot o su lle lo ca lit à d el v ib on es e. l e im m ag in i, p re se d al li b ro d i p u g li e s e (1 99 7) , s on o an ch e ra p p re se nt at iv e d el le tip ol og ie e d ili zi e, m ol to p ov er e, in u so a ll’ ep oc a ne lla z on a d el t er re m ot o. a ) v ib o v al en tia (e x m on te le on e) ; b ) p is co p io ; c ) z am m ar ò; d ) p ar gh el ia . s om e p ho to s ab ou t th e d is as tr ou s ef fe ct s of t he e ar th q ua ke . in t he p ho to s th e p oo r q ua lit y of b ui ld in gs i s cl ea rly v is ib le . a) v ib o v al en tia ( ex m on te le on e) ; b ) p is co p io ; c) z am m ar ò; d ) p ar gh el ia . t he p ho to s ar e fr om t he b oo k of p u g li e s e (1 99 7) . l. cucci & a. tertulliani 93 fi g. 3 i n fig ur a vi en e m os tr at o il se tt or e ce nt ra le d el p ia no q uo ta to d el t er re m ot o d el l’8 s et te m b re 1 90 5. n el r iq ua d ro è r ip or ta to i l d et ta gl io d el l’a re a d i m as si m a in te ns ità . la s ca la d el le in te ns ità è la s te ss a p er le d ue fi gu re . i l r et ta ng ol o vi si b ile in fi gu ra r ap p re se nt a la s or ge nt e d i r ife rim en to c om e ot te nu ta d al p ro gr am m a b ox er (g a s p e r in i et a l., 1 99 9) . l a st el la in d ic a l’e p ic en tr o ca lc ol at o d al m ed es im o co d ic e. p er l’ in ve rs io ne s on o st at i u sa ti i p un ti d i i nt en si tà i≥ 89. in te ns ity d at a m ap o f th e s ep te m b er 8 , 19 05 e ar th q ua ke ; w e al so s ho w a z oo m o f th e ep ic en tr al a re a. t he in te ns ity s ca le f or t he t w o fig ur es is t he s am e. w e al so in d ic at e th e so lu tio n of t he so ur ce m od el w ith a s ol id b ox , a nd t he m ac ro se is m ic e p ic en tr e w ith t he b la ck s ta r, b ot h co m p ut ed b y th e b ox er c od e (g a s p e r in i et a l., 1 99 9) . o nl y in te ns iti es i≥ 89 w er e us ed t o co m p ut e th e so ur ce m od el . t he s ol ut io n sh ow n is o b vi ou sl y co ns tr ai ne d b y th e in te ns ity d at a se t, t ha t p ar tia lly r ep re se nt s th e at te nu at io n fie ld o f t he e ve nt , e lo ng at ed o n th e co as t. i terrazzi marini nell’area ... 94 eustatica) è possibile ricostruire con grande accuratezza la storia dei sollevamenti della regione costiera in esame, nonché cercare di separare gli effetti del sollevamento regionale da quelli della deformazione locale imposta dalla vicinanza di faglie attive. i terrazzi di capo vaticano sono già stati investigati da alcuni autori, con risultati ed interpretazioni anche profondamente discordanti. a titolo di esempio, dumas et al. (1987) individuano almeno 25 paleolinee di riva pleistoceniche e suggeriscono che il sollevamento differenziale osservato nel settore settentrionale è in qualche modo connesso all’attività della faglia ‘b’ in figura 1. westaway (1993) riconosce solo cinque terrazzi pleistocenici, sollevati uniformemente al tasso di 1 mm/anno e deformati ad un ulteriore tasso di 0,05 mm/anno dalla faglia ‘a’ (fig. 1). al contrario, miyauchi et al. (1994) descrivono almeno 12 ordini di terrazzi, sollevati a tassi oscillanti fra 0,3 e 1,0 mm/anno a causa dell’alternarsi di “doming uplift” e di “regional uplift”, che costituiscono anche l’unica causa di deformazione nell’area. infine, tortorici et al. (2003) riconoscono sei terrazzi completi (più una superficie superiore) e ricostruiscono, esclusivamente sulla base di datazioni tl, sollevamenti compresi fra 0,9 e 4,0 mm/anno, attribuendo la differenza tra questi due valori a deformazione tettonica locale, in gran parte lungo la faglia ‘e’ di fig. 1. nel presente lavoro, la ricostruzione dei terrazzi è stata ottenuta tramite interpretazione aerofotogrammetrica, analisi di carte topografiche alla scala 1:10.000, ed osservazioni di campagna; l’errore associato alle quote rilevate è di ±5 m. margini interni e superfici terrazzate così mappati sono stati correlati morfologicafig. 4 mappa dei margini interni e delle superfici terrazzate cartografati nell’area in studio in base alle foto aeree ed al rilevamento di campagna. i terrazzi sono numerati in ordine crescente di quota. l’attribuzione cronologica dei terrazzi è basata sulla correlazione con i picchi interglaciali della curva eustatica di waelbroeck et al. (2002). vengono anche riportati gli estremi a-b del profilo altimetrico di figura 5 e le tracce dei profili topografici 1 e 2 di figura 6. map of the marine terraces (#1 to #11, lowest to highest) that contour the study area; different colours are associated with the wavecut platforms and black thick lines mark the inner edges. the age of the terraces is based on the correlation with the interglacial peaks of the eustatic curve by waelbroeck et al. (2002). black segments marked by “1” and “2” indicate the traces of the topographic profiles in figure 5; letters “a” and “b” indicate the tips of the profile in figure 6. l. cucci & a. tertulliani mente, basandosi sulla continuità laterale dei terrazzi meglio conservati e sulla spaziatura verticale fra interfluvi adiacenti. questo processo ha portato all’identificazione di 11 terrazzi marini principali (ordinati da t1 a t11 per quote crescenti, fig. 4), con quote comprese fra 20 e 575 metri slm. le piattaforme di abrasione marina possono essere incise sia direttamente sul basamento metamorfico paleozoico, sia su depositi marini plio-pleistocenici. i depositi di terrazzo consistono in sabbie e arenarie marine a contenuto fossilifero quasi sempre scarso. le superfici terrazzate sono generalmente ben preservate (fig. 5); i margini interni ad esse associati, spesso chiaramente riconoscibili per chilometri, sono coperti localmente da un sottile strato di depositi colluviali. a causa di una più prolungata degradazione subaerea i terrazzi più alti e vecchi sono morfologicamente meno evidenti, mentre la superficie sommitale affiorante fino alla quota di ~700 metri appare più profondamente erosa e priva di margine interno. l’andamento delle quote dei margini interni dei terrazzi su un piano verticale parallelo alla linea di costa (fig. 6) è piuttosto variabile. è evidente un incremento delle altezze procedendo verso so, fino alla progressiva km 40 del profilo. il gradiente locale di sollevamento differenziale aumenta procedendo verso i terrazzi più antichi e sollevati, a testimonianza di un processo prolungato nel tempo e tuttora in atto, mentre il progressivo aumento del tasso di basculamento (rapporto fra gradiente locale ed età del singolo terrazzo) in senso inverso è indicativo di un aumento, seppur modesto, delle velocità di sollevamento. a sud di capo vaticano (km 40-45) i terrazzi raggiungono la massima altezza sul livello del mare, mentre il sollevamento differenziale si annulla. si osservano, inoltre, due zone con evidenti anomalie nell’andamento sub-orizzontale dei terrazzi, alle progressive km 18-23 e km 45-50. la ricostruzione della storia dei sollevamenti nell’area studiata si basa sulla revisione critica di una serie di datazioni disponibili in letteratura (vedi box in fig. 4). la datazione-correlazione chiave è quella di vibo marina, dove t3 è stato associato al picco dell’ultimo interglaciale (mis 5.5, ~124 ka), sulla base di una robusta convergenza di: a) la presenza di strombus bubonius nel deposito terrazzato (pata, 1947); b) due datazioni radiometriche u-th indipendenti effettuate su campioni di cladocora caespitosa da dumas et al. (1991) e da dai pra et al. (1993) con risultati omogenei (130.000 anni ± 8.000 e 121.000 anni ± 7.000, rispettivamente); c) una datazione aar su glycymeris che ha fornito un ratio di aminoacidi di 0,37±0,03 (dumas et al. 1989), in accordo con un’età dell’ultimo interglaciale. a conferma della correlazione t3-mis 5.5 c’è l’osservazione che all’highstand più pronunciato e prolungato nel tempo corrisponde il terrazzo morfologicamente più sviluppato e continuo della zona. sulla base delle evidenze citate la figura 7 suggerisce che la storia dei sollevamenti nell’area può essere tracciata a ritroso nel tempo fino a circa 600-700.000 anni fa, con la formazione e la successiva emersione dei due terrazzi superiori (t10 e t11), per i quali comunque esiste un margine di incertezza più ampio. per quanto riguarda la genesi della superficie sommitale, essa è presumibilmente di età siciliana inferiore (~1 ma) sulla base della presenza di globorotalia truncatulinoi95 fig. 5 profili topografici lungo due sezioni rappresentative dell’area in studio (vedi fig. 4 per la localizzazione delle sezioni). i segmenti più spessi marcano le superfici di terrazzo. la scala verticale è esagerata 3x. topographic profiles along two sections representative of the area (see fig. 4 for location of the sections). thicker lines mark the different terrace surfaces. vertical exaggeration of both profiles is 3x. i terrazzi marini nell’area ... des excelsa nei depositi ad essa associati (miyauchi et al. 1994). pur mancando evidenze di brusche variazioni nei tassi di sollevamento calcolati per ogni intervallo di tempo fra due terrazzi consecutivi, tale processo sembra in lieve ma progressivo aumento nel tempo, con velocità medie che passano da ~0,79 mm/anno (calcolate nel periodo 0,7-0,5 ma) a ~0,93 mm/anno (a partire dal picco dell’ultimo interglaciale). in particolare, i valori illustrati in figura 7 sono riferiti alla zona di capo vaticano, dove le paleolinee di riva raggiungono le massime quote nell’area in studio e dove la sequenza di terrazzi è presente quasi al completo. più in generale, lo studio dei terrazzi marini in quest’area mette in luce un inizio del processo di sollevamento a 0.7-1.0 ma e velocità medie leggermente inferiori a 1 mm/anno. tali caratteristiche sono pienamente confrontabili con quelle osservate lungo i ~200 km di arco calabro che vanno dalla piana di sibari a nord all stretto di messina a sud (vedi, fra gli altri: westaway, 1993; bordoni & valensise, 1998; cucci, 2004; ferranti et al. 2006). a sud di capo vaticano (fra le progressive km 45 e 50 di fig. 4) le paleolinee di riva sono intersecate da una struttura tettonica ad andamento ono-ese (faglia ‘e’ in fig. 1, “coccorino fault” o “calimera fault” auct). lo stato di attività di questa faglia è piuttosto dibattuto fra gli autori, dato che alcuni la ritengono tuttora attiva dal pleistocene superiore (michetti et al. 2000; tortorici et al. 2003), altri le attribuiscono una generica attività durante il quaternario (ambrosetti et al. 1987; miyauchi et al. 1994), mentre dumas et al. (1987), 96 fig. 6 andamento altimetrico delle linee di riva lungo una sezione parallela alla costa. i colori corrispondono a quelli di figura 4. elevation profile of inner edges (black thick lines) and wavecut platforms (coloured areas, same colors of fig. 4) along a vertical section parallel to the coast. fig. 7 il grafico mette in relazione il sollevamento netto delle paleolinee di riva a capo vaticano (quota di osservazione corretta per il paleolivello del mare all’epoca della formazione) con l’età corrispondente desunta dalla curva eustatica di waelbroeck et al. (2002). vengono anche indicati i tassi di sollevamento calcolati per ogni intervallo di tempo fra due terrazzi consecutivi. relation between the net uplift of the paleoshorelines at capo vaticano, calculated as the observed elevation corrected for the altitude of the paleosea-level, and the corresponding ages from the sea-level curve by waelbroeck et al. (2002). figures indicate calculated uplift rates between adjacent couples of terraces. l. cucci & a. tertulliani galadini et al. (2000) e valensise & pantosti (2001) la considerano inattiva o non la riconoscono. a tale struttura è comunque associata una evidente scarpata morfologica di una decina di chilometri di lunghezza, la cui continuazione offshore per un tratto almeno altrettanto lungo è molto probabile dall’osservazione della batimetria (argnani & trincardi, 1988). le paleolinee di riva appaiono chiaramente dislocate e la valutazione dell’entità delle dislocazioni permette di ricavare informazioni sull’attività di questa faglia. in figura 8 evidenziamo la separazione verticale osservata sui quattro terrazzi inferiori con i corrispondenti tassi verticali medi a lungo termine attraverso la struttura tettonica, che oscillano fra 0,12 mm/anno e 0,16 mm/anno. tassi verticali su periodi più brevi possono essere desunti dalla dislocazione netta calcolata su ogni coppia di paleolinee consecutive; gli slip rates verticali così ottenuti variano tra 0,04÷0,06 mm/anno (fra il mis 9.3 ed il mis 5.5 – da 330 ka a 124 ka) e 0,21÷0,25 mm/anno (fra il mis 5.5 ed il mis 5.1 – da 124 ka a 80 ka). discussione l’applicazione del codice boxer (gasperini et al. 1999) al campo macrosismico revisionato del terremoto del 1905 mostra come la più probabile struttura sismogenetica responsabile dell’evento possa essere una faglia di dimensioni 36x14 km e direzione ~80º. parallelamente, abbiamo anche visto come le variazioni altimetriche osservate lungo le paleolinee di riva attraverso la faglia ‘e’, la cui direzione è invece circa 100°, abbiano permesso di confermare che tale struttura è attiva. per verificare quanto ognuna di queste due strutture sia congruente con gli elementi geologici, topografici e macrosismici a disposizione, abbiamo calcolato e posto a confronto il campo di deformazione indotto in superficie dall’azione della faglia ottenuta da boxer (faglia “macrosismica”) rispetto a quello della faglia osservata in campagna (faglia “geologica”). la modellazione, basata sulla teoria della dislocazione elastica ed eseguita con il codice ‘faultstudio’ (basili, 2005) assume uno slip uniforme su faglie piane e rettangolari in un semi-spazio elastico (okada, 1985). geometria e dimensioni delle due strutture sono vincolate in un caso dall’output del programma boxer per la faglia “macrosismica”, nell’altro dalle evidenze morfologiche e batimetriche già descritte, oltre che dall’alto valore di magnitudo associato all’evento del 1905. la figura 9 mostra qualitativamente i risultati di questo test applicato a quattro differenti ipotetiche sorgenti sismogenetiche secondo il seguente criterio: una coppia di strutture tipo “macrosismica”, in cui rimanendo costanti tutti gli altri parametri viene fatta variare solo la vergenza della 97 fig. 8 in questo ingrandimento fra le progressive km 43 e 53 di figura 4 evidenziamo la dislocazione verticale delle quattro paleolinee di riva inferiori attraverso la faglia ‘e’. vengono anche indicati i corrispondenti tassi verticali medi a lungo termine attraverso la struttura tettonica, che oscillano fra 0,12 mm/anno e 0,16 mm/anno. this zoom between km 43 and 53 of figure 4 shows the vertical separation evidenced along the four lower paleoshorelines across fault ‘e’. long-term vertical slip rates across this structure range between 0.12 and 0.16 mm/yr. i terrazzi marini nell’area ... 98 fi g. 9 v ar ia zi on i a lti m et ric he p re vi st e d a m od el la zi on i d i f ag lie p ia ne e r et ta ng ol ar i i n un s em isp az io e la st ic o. p er o gn i m od el la zi on e rip or tia m o la z on a d i m as si m o so lle va m en to e s ub si d en za a sp et ta ti (e sp re ss i c om e fr az io ne d el lo s lip un ita rio ), ol tr e al la p ro ie zi on e ve rt ic al e d el p ia no d i f ag lia e d a lla s ua in te rs ez io ne c on la s up er fic ie . m od el lin g of e xp ec te d v er tic al d is p la ce m en t (e xp re ss ed a s a fr ac tio n of t he u ni ta ry s lip ) al on g p la na r fa ul ts e m b ed d ed i n an e la st ic h al fsp ac e. w e al so s ho w t he c ut -o ff l in e of t he u p -d ip p ro je ct io n of t he m od el fa ul t an d it s su rf ac e p ro je ct io n. l. cucci & a. tertulliani faglia (60° verso nno o verso sse, rispettivamente), dato che il programma “boxer” non fornisce informazioni al riguardo; una coppia di strutture tipo “geologica” in cui, rimanendo costanti tutti gli altri parametri, viene fatta variare solo la cinematica della faglia (normale pura in un caso, transtensiva sinistra nell’altro). per ogni modellazione la figura riporta la zona di massimo sollevamento e subsidenza aspettati (espressi come frazione dello slip unitario), oltre alla proiezione verticale del piano di faglia ed alla sua intersezione con la superficie. le due modellazioni relative alla faglia “boxer” forniscono indicazioni piuttosto discordanti. infatti, il campo di deformazione associato alla faglia nord-vergente interessa marginalmente l’area di massima intensità, mentre la soluzione con il piano di faglia sud-vergente è quella che meglio circoscrive all’interno dell’area a massimo gradiente di deformazione aspettato i punti di maggiore intensità osservate. inoltre, la soluzione con la faglia sud-vergente è quella che meglio giustifica la generazione di un maremoto, dato che produrrebbe deformazioni verticali apprezzabili nell’area che è stata effettivamente interessata dall’azione dello tsunami associato all’evento del 1905 (vedi anche piatanesi & tinti, 2002). d’altro canto, nessuna delle due soluzioni “boxer” sembra essere in accordo con le evidenze topografiche e/o geomorfologiche, dato che le aree di depressione allungata che esse produrrebbero non hanno riscontro con l’andamento reale della topografia, né tantomeno con l’andamento delle quote dei terrazzi marini. le due modellazioni ottenute con la faglia “geologica” forniscono indicazioni piu’ omogenee. la soluzione con rake = 270º (faglia normale pura) produrrebbe un gradiente di deformazione simmetrico trasversalmente al piano di faglia, con una depressione piuttosto pronunciata al margine settentrionale della piana di gioia tauro ed un più modesto sollevamento nella dorsale di monte poro. questa soluzione conferma inoltre un elevato accordo fra campo di deformazione previsto ed andamento delle quote delle linee di riva, che verrebbero cosismicamente sollevate soprattutto nei dintorni di capo vaticano e subirebbero una vistosa subsidenza spostandosi verso sud fino a nicotera. la soluzione con rake = 315º (faglia normale con componente trascorrente sinistra) ricalca sostanzialmente quella appena descritta, all’infuori di un gradiente di deformazione leggermente meno ‘piccato’ nei valori assoluti e di un’area di massima subsidenza spostata in mare aperto, che però non ne modifica qualitativamente il confronto con le evidenze topografiche e geomorfologiche. entrambe le soluzioni, infine, mostrano un accordo solo parziale con i dati macrosismici a disposizione, mentre produrrebbero deformazioni verticali vistose nell’area interessata dallo tsunami del 1905. i dati geologici e macrosismici presentati in questo lavoro, nonché il loro confronto con le elaborazioni provenienti dalle modellazioni di sorgenti sismogenetiche, forniscono una serie di evidenze ed offrono lo spunto per la discussione di un numero di questioni ancora aperte. le evidenze sono: a) sono stati riconosciuti undici terrazzi marini principali; b) l’area di capo vaticano è in sollevamento attivo da almeno 700.000 anni, a velocità medie leggermente inferiori a ~1 mm/anno; c) il processo di sollevamento sembra in lieve ma progressivo aumento nel tempo, con velocità medie che passano da ~0,79 mm/anno (fra 0,7 e 0,5 ma) a ~0,93 mm/anno (ultimi 124 kyr); d) è evidente un fenomeno di tilting di terrazzi, con altezze delle paleolinee di riva progressivamente minori procedendo lungo la costa da sud (capo vaticano) verso nord (pizzo). il tilting diviene trascurabile a sud di capo vaticano; e) le variazioni di quota osservate nelle paleolinee di riva a cavallo della faglia ‘e’ indicano che tale struttura è attiva da almeno 330.000 anni; f) i tassi verticali medi sulla faglia ‘e’ variano negli ultimi 215.000 anni fra 0,12 e 0,16 mm/anno. ci sono evidenze di tassi verticali maggiori (fino a 0,25 mm/anno) relativi a periodi più brevi; g) il piano quotato rivisitato del terremoto del 1905 conferma che le massime intensità sono state raggiunte in un’area estesa fra vibo valentia e capo vaticano; h) la magnitudo macrosismica (m=6.8) conferma l’importanza dell’evento in termini energetici. le evidenze appena descritte possono altresì fornire un contributo importante nell’approccio della questione fondamentale riguardante il rapporto fra l’evento del 1905, la sua sorgente, e le faglie sismogenetiche nell’area. abbiamo visto che i terrazzi marini forniscono una chiara indicazione sullo stato di attività recente della faglia ‘e’, anche se è probabile che tale struttura non sia l’unica attiva nell’area; abbiamo anche constatato come la faglia ‘e’, indipendentemente dal tipo di cinematica imposta (normale pura o con componente trascorrente), sia pienamente compatibile con la magnitudo dell’evento del 1905 (ed indirettamente anche con il dato di magnitudo ottenuto per via macrosismica), e produca deformazioni verticali vistose nell’area interessata dall’azione dello tsunami associato all’evento stesso. se si considera che la modellazione del dato macrosismico fornisce indicazioni vincolanti soprattutto per le dimensioni della sorgente e che il più recente lavoro di rilocalizzazione del terremoto del 1905 ne colloca l’epicentro a mare (sebbene con un certo margine di errore) ad una ventina di chilometri ad ovest di capo vaticano (michelini et al. 2005), allora anche l’apparente scarso accordo fra deformazione teorica prodotta dalla faglia e campo macrosismico reale prodotto dal terremoto potrebbe assumere un significato diverso. in questo caso l’epicentro di michelini et al. (2005) potrebbe corrispondere alla nucleazione unilaterale lungo una struttura ad elevata direttività, così da giustificare da un lato la sostanziale omogeneità nelle intensità osservate in tutto il promontorio di capo vaticano data la notevole distanza dall’epicentro, e dall’altro l’evidente decremento delle intensità registrate nella piana di gioia tauro. in questo caso tale faglia agirebbe, con una possibile cinematica transtensiva, come lineamento regionale trasversale di trasferimento della deformazione estensionale fra le già citate strutture ad andamento ne-so nell’offshore tirrenico e quelle, con il medesimo andamento, riportate nella piana di gioia tauro (valensise & pantosti, 2001; galli & bosi, 2002). in conclusione, l’analisi di dati geologici evidenziati dai terrazzi marini ed il confronto con lo scenario del terremoto desunto dalle osservazioni macrosismiche hanno permesso la ricostruzione della storia dei sollevamenti nell’area di capo vaticano e la formulazione di alcune ipotesi riguardanti geometria e cinematica della sorgente del terremoto del 1905. pur nella consa99i terrazzi marini nell’area ... pevolezza che esistano soluzioni alternative, ed auspicando una più cospicua mole di dati di tipo strutturale soprattutto nell’offshore tirrenico, la soluzione proposta indica una struttura con una chiara espressione morfologica e batimetrica, con una attività recente ed attuale testimoniata dalla geologia e dalla microsismicità, in un quadro nel quale la deformazione tettonica locale associata a sorgenti sismogenetiche rimane comunque quasi un ordine di grandezza inferiore al sollevamento regionale. ringraziamenti desideriamo ringraziare i due referees anonimi per i commenti e i preziosi suggerimenti che hanno contribuito a migliorare l’articolo. questo lavoro è stato finanziato nell’ambito della convenzione dpc-ingv, progetto s2: “valutazione del potenziale sismogenetico e probabilità dei forti terremoti in italia”. bibliografia aïfa t., feinberg h. & pozzi j.p. (1988) pliocenepleistocene evolution of the tyrrhenian arc: paleomagnetic determination of uplift and rotational deformation, earth planet. sci. lett., 87, 438452. ambrosetti p., bosi c., carraro f., ciaranfi n., panizza m., papani g., vezzani l. & zanferrari a. (1987) neotectonic map of italy, quad. ric. scient., 114, 4. argnani a. & trincardi f. (1988) paola slope basin: evidence of regional contraction of the eastern tyrrhenian margin, mem. soc. geol. it., 44, 93105. baratta m. (1906) il grande terremoto calabro dell’ 8 settembre 1905, atti soc. toscana di sc. nat., xxii, pp. 57-80 barberi g., cosentino m.t., gervasi a., guerra i., neri g. & orecchio b. (2004) crustal seismic tomography in the calabrian arc region, south italy, physics of the earth and planetary interiors, 147, 297-314. basili r. (2005) new software for the analysis of landscape response to faulting, wp8:modelling of topographic signal, deliverable 8.3, eu project safe, evg1-2000-2005. bordoni p.& valensise g. (1998) deformation of the 125 ka marine terrace in italy: tectonic implications, in: stewaer i.s. & vita-finzi c. (eds.), coastal tectonics. geological society, london special publications, 146, 71-110. boschi e., guidoboni e., ferrari g., valensise g., gasperini p. (1995) catalogo dei forti terremoti in italia dal 461 a.c. al 1980, ing-sga, bologna. bousquet j.c. (1973) la tectonique récente de l’apennin calabro-lucanien dans son cadre géologique et géophysique, geol. rom., 12, 1-103. brogan g.e., cluff l.s. & taylor c.l. (1975) seismicity and uplift of southern italy, tectonophysics, 29, 323-330. camassi r. & stucchi m. (a cura di) (1997) nt4.1 un catalogo parametrico di terremoti di area italiana al di sopra della soglia del danno. cnr-gndt. http://emidius.mi.ingv.it/nt/ castello b., moro m., chiarabba c., di bona m., doumaz f., selvaggi g. & amato a. (2004) revised magnitudes of relocated italian earthquakes catalogue (1981-2002): a new seismicity map of italy, riassunti del xxiii congresso del gruppo nazionale di geofisica della terra solida (gngts), 220-222, 14-16 dicembre 2004, roma. chiocci f.l. & orlando l. (1996) lowstand terraces on tyrrhenian sea steep continental slopes, mar. geol., 134, 127-143. cotroneo r. (1906) in calabria. in giro sulle rovine del terremoto. edizioni brenner, cosenza, 1990. cucci l. (2004) raised marine terraces in the northern calabrian arc (southern italy): a ~600 ka-long geological record of regional uplif, ann. geophys., 47, 4, 1391-1406. dai pra g., miyauchi t., anselmi b., galletti m. & paganin g. (1993) età dei depositi a strombus bubonius di vibo valentia marina (italia meridionale), il quaternario, 6(1), 139-144. dumas b., gueremy p., lhenaff r.& raffy j. (1987) rates of uplift as shown by raised quaternary shorelines in southern calabria (italy), z. geomorph. n. f., 63, 119-132. dumas b., gueremy p., hearty p.j., lhenaff r. & raffy j. (1989) difficulties with connecting geomorphological transects and dating a lot of late quaternary uplifted shorelines in the capo vaticano peninsula (south italy), in: geooko, 2nd int. conf. geomorphol., frankfurt/main, 3-9 sept., 1, pp. 79-80. dumas b., gueremy p., hoang c., lhenaff r. & raffy j. (1991) gisement et rivages tyrrheniens de vibo marina (italie du sud): datation 230th/234u, soulevement differentiel de la calabre meridionale, c. r. acad. sci. paris, 312, 785-791. ferranti l., antonioli f., mauz b., amorosi a., dai pra g., mastronuzzi g., monaco c., orrù p., pappalardo m., radtke u., renda p., romano p., sansò p. & verrubbi v. (2006) markers of the last interglacial sea-level high stand along the coast of italy: tectonic implications, quat. int., 145-146, 30-54. galadini f., meletti c. & vittori e. (2000) stato delle conoscenze sulle faglie attive in italia: elementi geologici di superficie, in: galadini f., meletti c. & rebez a. (eds.), le ricerche del gndt nel campo della pericolosità sismica (1996-1999), internal report of cnr-gruppo nazionale per la difesa dai terremoti, roma, 397 pp. galli p. & bosi v. (2002) paleoseismology along the cittanova fault: implications for seismotectonics and earthquake recurrence in calabria (southern italy), j. geoph. res. 107, b3, 2044, 10.1029/ 2001jb000234, 2002. gasperini p. & ferrari g. (1995) stima dei parametri sintetici, in catalogo dei forti terremoti italiani dal 461 a.c. al 1980, e. boschi et al. (ed.), ing-sga publ., 96-111. gasperini p., bernardini f., valensise g., boschi e. (1999) defining seismogenic sources from historical earthquake felt reports, bull. seism. soc. am., 89, 94-110. 100 l. cucci & a. tertulliani gignoux m. (1913) les formations marines pliocènes et quaternaires de l’italie du sud et de la sicile, annales de l’université de lyon, 36. giunchi c., sabadini r., boschi e. & gasperini p. (1996) dynamic models of subduction: geophysical and geological evidences in the tyrrhenian, geophys. j. int., 126, 555-578. gruppo di lavoro cpti (2004) catalogo parametrico dei terremoti italiani. ing, gndt, sga, ssn, bologna 1999, 92 pp. gvirtzmann z. & nur a. (1999) plate detachment, asthenosphere upwelling, and topography across subduction zones, geology, 27, 563-566. hyppolite j.c., angelier j. & roure f. (1994) a major geodynamic change revealed by quaternary stress patterns in the southern apennines (italy), tectonophysics, 230, 199-210. kostner f. (2002) la tragedia di aiello calabro edizioni klipper, cosenza. malagodi o. (1905) calabria desolata, edizioni klipper, cosenza, ristampa 2005. malinverno a. & ryan w.b.f. (1986) extension in the tyrrhenian sea and shortening in the apennines as result of arc migration driven by sinking of the litosphere, tectonics, 5, 227-245. margottini c., ambraseys n.n. & screpanti a. (1993) la magnitudo dei terremoti italiani del xx secolo. enea, roma, 57 pp. meletti c., patacca e. & scandone p. (2000) construction of a seismotectonic model: the case of italy, pageoph, 157, 11-35. mercalli g. (1906) alcuni risultati ottenuti dallo studio del terremoto calabrese dell’ 8 settembre 1905, atti acc. pontoniana di napoli, xxxvi, mem. 8, pp. 1-9. michelini a., lomax a., nardi a., rossi a., palombo b. & bono a. (2005) a modern re-examination of the locations of the 1905 calabria and the 1908 messina straits earthquakes, geophysical research abstracts, 7, 07909, european geosciences union. michetti a.m., serva l., vittori e. (2000) ithaca (italy hazard from capable faulting), a database of active capable faults of the italian onshore territory, database on cd-rom. internal report of anpaagenzia nazionale protezione ambiente, roma. miyauchi t., dai pra g. & sylos labini s. (1994) geochronology of pleistocene marine terraces and regional tectonics in the tyrrhenian coast of south calabria, italy, il quaternario, 7(1), 17-34. mucciarelli m. (2005) gli effetti di sito del terremoto di pizzo calabro negli studi dell’epoca, 24° gngts, 15-17 novembre 2005, roma. okada y. (1985) surface deformation due to shear and tensile faults in a half-space, bull. seism. soc. am., 75, 1135-1154. pata o. (1947) su di un nuovo giacimento a strombus bubonius lmk presso vibo valentia, atti soc. tosc. sci. nat., 54, 159-166. piantanesi a. & tinti s. (2002) numerical modelling of the september 8, 1905 calabrian (southern italy) tsunami geophys. j. int., 150, 271-284. postpischl d., ed. (1985) catalogo dei terremoti italiani dall’anno 1000 al 1980, consiglio nazionale delle ricerche, progetto finalizzato geodinamica (cnr-pfg). quaderni de “la ricerca scientifica”, n. 1145, 2b, pp. 239. bologna. pugliese f. (1996) il terremoto dell'8 settembre 1905 in calabria, arti grafiche bmb, firenze,. rizzo g.b. (1907) contributo allo studio del terremoto della calabria del giorno 8 settembre 1905, atti r. acc. peloritana, xxii, fasc. i, pp. 2-87. spakman w., van der lee s. & van der hilst r. (1993) travel-time tomography of the europeanmediterranean mantle down to 1400 km, phys. earth planet. inter., 79, 3-74. tortorici g., bianca m., de guidi g., monaco c. & tortorici l. (2003) fault activity and marine terracing in the capo vaticano area (southern calabria) during the middle-late quaternary, quat. int., 101-102, 269-278. trincardi f., cipolli m., ferretti p., la morgia j., ligi m., marozzi g., palumbo v., taviani m. & zitellini n. (1987) slope basin evolution on the eastern tyrrhenian margin: preliminary report, giornale di geologia, 49/2, 1-9. valensise g. & pantosti d. (eds.) (2001) database of potential sources for earthquakes larger than m 5.5 in italy, supplement. to ann. geofis., 44 (4). waelbroeck c., labeyrie l., michel e., duplessy j.c., mcmanus j.f., lambeck k. balbon, e. & labracherie m. (2002) sea-level and deep water temperature changes derived from benthic foraminifera isotopic records. quat. sci. rev., 21, 295305. wells, d. & coppersmith k. (1994) new empirical relationships among magnitude, rupture length, rupture width, rupture area and surface displacement, bull. seismol. soc. am., 84, 974–1002. westaway r. (1993) quaternary uplift of southern italy, j. geophys. res., 98, 21741-21772. 101 ms. ricevuto il 16 maggio 2006 testo definitivo ricevuto il 10 ottobre 2006 ms. received: may 16, 2006 final text received: october 10, 2006 i terrazzi marini nell’area ... imp.bini_zuccoli prime note sul rilevamento dell'anfiteatro del garda: metodi e unità provvisorie alfredo bini & luisa zuccoli dipartimento di scienze della terra, università degli studi di milano, via mangiagalli 34, 20133 milano; alfredo.bini@unimi.it riassunto: bini a. & zuccoli l., prime note sul rilevamento dell’anfiteatro del garda: metodi e unità provvisorie. (it issn 0394-3356, 2004). l'anfiteatro del garda mostra alcuni caratteri peculiari, sia petrografici sia geomorfologici, diversi da quelli che si osservano negli altri apparati alpini, per cui è sempre risultato difficile separare le cerchie moreniche sulla base della classica suddivisione in glaciazioni del quaternario alpino. il principale problema di questo anfiteatro è quello della attribuzione delle diverse cerchie moreniche riguardo al quale le opinioni dei vari e numerosi autori sono contrastanti. i dati del presente rilevamento non sono direttamente confrontabili con quelli degli autori citati in quanto è diverso il linguaggio e non esiste alcun sistema per passare da uno all'altro senza equivoci ed incertezze. il würm degli autori precedenti non coincide con il concetto di lgm attualmente in uso. il würm degli autori comprende probabilmente più glaciazioni nel senso di richmond (1986). in assenza di paleosuoli diffusi, i parametri che sono stati utilizzati per riconoscere le unità sono stati: l'alterazione e il colore del colluvio, lo spessore del calcrete, la geometria dei depositi. benchè il colluvio sia costituito da depositi di colate che hanno spesso rimescolato il materiale originario proveniente da unità diverse esistono particolari situazioni, molto diffuse in anfiteatro, in cui il colluvio proviene solo da una unità, omogenea dal punto di vista sedimentologico, o, meglio, da una sola morena. tenendo conto di queste situazioni esiste un "gradiente di caratteristiche" del colluvio andando dalle rive del lago (unità più recenti), alle unità più antiche. la presenza o l'assenza del calcrete sommitale, così come il suo spessore, sono parametri determinanti sul garda. il calcrete è presente su tutte le unità ad esclusione dell'unità più interna (alloformazione del garda) che ne è completamente priva e che perciò è lo lgm. muovendosi verso l'esterno il calcrete aumenta rapidamente di spessore sino ad interessare l'intera massa dei depositi delle unità. sono state così riconosciute varie unità alloe litostratigrafiche, di cui otto sono costituite da till e rappresentano qundi glaciazioni distinte. abstract: bini a. & zuccoli l., geological survey in the garda moraine amphitheatre: methods and preliminary units (it issn 03943356, 2004). the garda glacial amphitheatre shows some peculiar geomorphological and petrographical features, which differ from those of the other alpine glacial amphitheatres. therefore it has been always difficult to separate the end moraines based on the traditional classification of the quaternary alpine glaciations. the most debated topic regarding the characterisation of the garda amphitheatre, is the correlation among the different end moraines, about which there is no agreement in literature. the results of the survey presented here are not comparable with the data by the previous authors, because different concepts and terminology are used and a conversion to older stratigraphic concepts is not available. for instance the term würm is not coincident with the lgm concept, which is in use at present. the würm auct. includes probably more glaciations (sensu richmond, 1986). if no widespread palesoils are available, other parameters are used to identify the different units, such as weathering and colour of colluvium, thickness of calcretes, geometry of depositional units. the colluvial deposits derive from flows which often mix materials from different sources; nonetheless in a lot of situations, within one amphitheatre, colluvium derives from one single unit, with own sedimentological features, or from a single moraine. taking into account these situations there is a continuum of variations of the features of colluvial deposits, moving from the youngest units (close to the lake shores) to the eldest ones. in the garda amphitheatre, presence or absence of calcrete, and its thickness, represent discriminant features. calcretes are present above all the depositional units, but the most internal one (garda alloformation), which represents the lgm. thickness of calcretes increases systematically moving towards the external sector of the amphitheatre, whose units are therefore completely cemented. in this way several alloand lithostratigraphic units could be recognised, eight of which are formed by tills and therefore represent different glaciations. parole chiave: anfiteatro morenico, morene, colluvio, calcrete, garda keywords: moraine amphitheatre, moraine, colluvium, calcrete, garda il quaternario italian journal of quaternary sciences 17(2/1), 2004, 333-342 introduzione l'anfiteatro del garda, sin dagli albori della teoria glaciale, è uno dei più noti al mondo; infatti, solo per fare un esempio, se si cerca la sottovoce moraine amphitheatres nella encyclopedia of geomorphology di r.w. fairbridge edita da dowden, hutchinson & ross inc. del 1968 si trova citato come unico esempio il garda e una carta dell'anfiteatro del garda si trova alla voce laghi. non stupisce quindi che numerosi ricercatori si siano via via interessati al suo studio. poichè questo anfiteatro mostra alcuni caratteri peculiari, sia petrografici sia geomorfologici, diversi da quelli che si osservano negli altri apparati alpini, è sempre risultato difficile separare le cerchie moreniche sulla base della classica suddivisione in glaciazioni del quaternario alpino. dopo aver rilevato direttamente gli anfiteatri del verbano, del lario e dell'iseo e discusso con coloro che hanno rilevato gli anfiteatri tilaventino e di rivoli torinese, appurato che la metodologia messa a punto in tutti questi anni è valida sia per la cartografia sia per la ricostruzione della storia geologica, si è iniziato il rilevamento dell'anfiteatro del garda con criteri moderni a partire dall'area occidentale all'incirca fra salò e esenta a sud di lonato (fig. 1). 334 a. bini & l. zuccoli il problema dell'età delle cerchie moreniche il principale problema dell'anfiteatro è quello dell'attribuzione delle diverse cerchie moreniche. la letteratura abbonda di lavori eseguiti sulla base di osservazioni generali o di studi dettagliati di singole sezioni estrapolati a tutto l'anfiteatro. gli unici rilevamenti geologici completi sono stati quelli di cozzaglio (1933; 1934a; 1934b; 1939) e di venzo (1957, 1961, 1965). quello che penck e bruckner (1909) hanno considerato riss, viene considerato mindel da venzo e il würm dei due autori transalpini, riss da venzo nel 1957 e würm nel 1961 poi ancora riss nel 1965 al termine dei rilevamenti. il würm di cozzaglio diviene riss per venzo (1957 e 1965): anche le numerose sovrapposizioni di würm sul riss, indicate da cozzaglio sul suo fo peschiera, sono inesistenti. si tratta del consueto fenomeno di erosione e dilavamento del paleosuolo rossiccio del riss, cosicchè affiorano le sottostanti ghiaie bianche di aspetto würmiano, ma di età sempre rissiana, come tutte le grandi cerchie. ... i grandi cordoni morenici del tratto orientale da s. zeno di montagna a pastrengo, si presentano ghiaiosi, bianchi e con versanti piuttosto ripidi, a morfologia giovanile. i lembi di paleosuolo rossastro-bruno del riss, giallastri se erosi del terreno più superficiale, sono ridotti ad esigui affioramenti solo all’ esterno ed in basso ai cordoni. basandosi sui lembi di paleosuolo in genere colluviati venzo (1965) pone il würm a ridosso del lago in posizione più interna rispetto al suo lavoro del 1957: di conseguenza il würm, ancora più interno, risulta glaciazione oltremodo ridotta. esso è testimoniato solo dalle ultime e più basse cerchie che orlano il lago; sbarrandolo verso sud. lo stadio würm iii ... è probabilmente arretrato di qualche decina di chilometri entro il lago. ... l’esiguità della glaciazione wiirmiana rispetto alla rissiana, risulta fenomeno generale a sud delle alpi... habbe (1969) critica il metodo di venzo e cozzaglio e, su base puramente morfologica, attribuisce il riss di venzo (1957 e 1965) al würm. cremaschi (1987), sulla base dello studio di alcune sezioni in tutto l'anfiteatro, fig. 1 foto da satellite dell'anfiteatro del garda e area interessata dallo studio. satellite image of the garda amphitatre and study area. considera pleistocene superiore il riss di venzo. il problema centrale risiede nell'età della cerchia più evidente che, nell'area interessata dal presente lavoro, coincide con il monte forca monte soffiano monte nuvolo monte malocco e che coincide con la cerchia di solferino. per venzo è rissiana, per habbe è würmiana, per cremaschi è pleistocene superiore. i dati del presente rilevamento non sono direttamente confrontabili con quelli degli autori citati in quanto è diverso il linguaggio e non esiste alcun sistema per passare da uno all'altro senza equivoci ed incertezze. in ogni caso, tale cerchia è compresa in un'alloformazione che con ogni probabilità è del pleistocene medio e non del pleistocene superiore. il presente lavoro si basa su un rilievo geologico, metro a metro, del territorio e di conseguenza si trova largamente in accordo con venzo (soprattutto 1957). e' stato osservato che all'interno delle cerchie rissiane di venzo sono presenti depressioni occupate da piccoli laghi. si è sostenuto che se i laghi sono ancora presenti le depressioni intermoreniche devono essere recenti e quindi da ascrivere al würm. in realtà, il problema dell'origine delle depressioni va tenuto separato da quello dell'origine dei laghi. non è sufficiente la presenza di una depressione per dare origine ad un lago; è necessario anche che il fondo della depressione sia impermeabile. quindi una depressione intermorenica più antica può ospitare in periodi più recenti un lago che non era presente all'origine perchè il suo fondo è stato successivamente impermeabilizzato. l'impermeabilizzazione può avvenire per accumulo di colluvio proveniente da suoli evolutisi nel tempo sulle morene, oppure per deposizione di loess durante una successiva glaciazione. non si ritiene pertanto che questa osservazione sia valida da un punto di vista geologico. un altro punto da considerare è che il würm degli autori precedenti e dei loro epigoni non coincide con il concetto di lgm attualmente in uso. a partire dai dati di terreno con metodi geologici o, al massimo, geocronometrici è possibile datare solo l'ultima espansione glaciale (lgm) che corrisponde secondo la definizione di richmond (1986), riportata in bini (1997) e in bini et al. (2001)1, all'ultima glaciazione. il würm degli autori comprende probabilmente più glaciazioni nel senso di richmond. poichè non vi sono criteri per collocare nel tempo i depositi glaciali più antichi dell'ultima glaciazione, non è possibile stabilire se le unità riconosciute sul terreno e appena più antiche dello lgm cadano nell'intervallo tempo che gli autori attribuivano al würm. in quest'ottica l'alloformazione del garda è lo lgm; l'alloformazione di puegnago e l'alloformazione di monte san pietro sono solo più vecchie dello lgm, ma non è possibile stabilire se rientrino, o no, nel periodo di tempo che gli autori attribuivano al würm, poichè non esistono metodi oggettivi per datarle. non ha senso 335prime note sul rilevamento ... quindi identificare il würm degli autori con lo lgm. nonostante le critiche che gli sono state rivolte, venzo è stato l'unico ad eseguire un rilievo geologico, che poteva essere condotto con maggior dettaglio già allora con la base cartografica a disposizione, ma che in ogni caso risponde a criteri geologici e non solamente geomorfologici. venzo ha applicato il suo schema delle glaciazioni a priori e perciò non poteva giungere a risultati diversi, ma ha oggettivamente separato la cerchia morenica più interna a causa dei suoi caratteri ben differenti da tutte le altre dell'anfiteatro assegnandola al würm. osserva che mancano il würm 2 e il würm 3 che egli ritiene meno estesi e percio coperti dal lago e osserva inoltre come l'alterazione aumenti nelle cerchie rissiane dalla più interna alla più esterna. ovvero le suddivisioni in unità operate in questo lavoro erano già state osservate da venzo, ma lo schema a priori da lui utilizzato gli ha impedito di riconoscerle apertamente. metodo impiegato nel rilevamento la suddivisione dei depositi presenti in unità allostratigrafiche, negli anfiteatri del verbano, del lario e del sebino, è stata possibile grazie alla presenza di paleosuoli; infatti l'unico modo per distinguere tra loro due corpi sovrapposti di depositi fluviali o glaciali, che abbiano lo stesso bacino di alimentazione, è la presenza di un suolo o comunque di un'alterazione a tetto dell'unità inferiore (richmond, 1962; bini, 1997; bini et al., 2001). nell'anfiteatro del garda i paleosuoli in posto sono rari, ma non del tutto assenti; il rilievo di dettaglio e l'attuale ampliamento dei vigneti hanno permesso, infatti, di osservarne un certo numero, anche se non è sufficiente a servire da marker per il riconoscimento di unità allostratigrafiche. solitamente si rinvengono spesse coltri di colluvio, sovrastanti depositi glaciali o fluvioglaciali che a tetto presentano un calcrete pedogenetico. lo spessore del calcrete è variabile, ma aumenta muovendosi dalle unità più recenti alle unità più antiche. il colluvio è spesso fortemente arrossato, sino a 5yr delle tavole munsell; presenta in molti casi inversione del profilo con la parte più arrossata in basso e quella meno arrossata in alto. anche in questo caso l'arrossamento del colluvio aumenta verso le unità più antiche. la differenza principale tra i depositi dell'anfiteatro del garda e quelli degli altri anfiteatri risiede nel fatto che sul garda i depositi sono costituiti interamente da clasti e da matrice carbonatici, mentre i clasti cristallini sono molto rari. nei suoli questo fatto comporta la formazione di spessi orizzonti calcici nelle unità più recenti e la completa cementazione delle unità più antiche. questi suoli si sono ovviamente formati in condizioni generali di biostasia. quando si è passati a condizioni di resistasia sia per cause naturali, come l'approssimarsi di un ghiacciaio durante una nuova glaciazione, sia per cause antropiche, come il disboscamento, l'aratura o la preparazione del terreno per la coltivazione della vite, l'intero spessore dei suoli si è mosso lungo i versanti per soliflusso o per colate, andando a costituire le coltri colluviali che attualmente si osservano. lo scivolamento del suolo per aumento del contenuto in acqua in condizioni di resistasia è stato facilitato 1"the term "glaciation" is applied here to a specific glacial advance and recession, the deposits of wich are separable from those of other glaciations by evidence of exstensive recession and downwasting of glaciers or by evidence of a warm climate as interpreted from pollen diagrams or weathering profiles. the terms "warm" and "cold" are used here in a very general sense to indicate broad differences in the climate of intervals separating glaciations." 336 ed è stato completo a causa della presenza del sottostante orizzonte calcico. questi, infatti, oltre ad essere praticamente impermeabile e capace quindi di sostenere una falda locale, costituisce una superficie piana, sufficientemente liscia che sui versanti inclinati delle morene ha rappresentato la superficie preferenziale di scivolamento. in assenza di paleosuoli diffusi, i parametri che sono stati utilizzati per riconoscere le unità sono stati: l'alterazione e il colore del colluvio lo spessore del calcrete la geometria dei depositi riguardo all'uso del colluvio come marker, che venzo (1957, 1961, 1965) aveva già utilizzato, è necessario fare alcune precisazioni. 1) il colluvio è costituito da depositi di colate che hanno spesso rimescolato e omogenizzato il materiale originario proveniente da unità diverse dal punto di vista stratigrafico. considerare come marker il colluvio in genere può essere quindi errato. esistono però particolari situazioni, molto diffuse in ambiente di anfiteatro, in cui il colluvio proviene solo da una unità, omogenea dal punto di vista sedimentologico, o, meglio, da una sola morena. la più chiara di queste situazioni, e una delle più diffuse, si ha quando il colluvio affiora pochi metri sotto la cresta di una morena, poichè in questo caso il colluvio può provenire solo dalla cresta. l'esempio tipico è a san pietro sopra polpenazze del garda (fig. 2) dove 2 o 3 metri sotto la cresta, si può descrivere il colluvio con inversione del profilo che rappresenta il suolo sommitale della morena di san pietro. oppure quando si ha una successione di morene di unità diverse, come in fig. 3 dove il colluvio compreso nella valle tra le unità a e b non è significativo, mentre lo è il colluvio sul lato interno della morena dell'unità b. l'insieme di numerose osservazioni di questo tipo, sulla cui validità non si può eccepire, associato alla geometria dei depositi consente di riconoscere e caratterizzare unità differenti. per quanto riguarda invece il colluvio presente sui depositi fluvioglaciali nei sandur si può essere sicuri della provenienza solo se il sandur era alimentato dal ghiacciaio relativo ad una singola unità, come, ad esempio, nella fig. 4 che schematizza la piana di s. tomaso-brodena, a sud di lonato, completamente compresa tra morene dell'alloformazione di san pietro e ben separata dalle morene dell'alloformazione del monte forca. in altri casi, dove l'alimentazione non è sicura, il colluvio su fluvioglaciale non è utilizzabile a fini stratigrafici. 2) indipendentemente da queste considerazioni esiste una variazione graduale delle caratteristiche del colluvio andando dalle rive del lago, in corrispondenza dell'unità più recente, alle unità più antiche, che comprende: il contenuto in argilla, il colore, la presenza di patine e/o noduli di ferro-manganese, la presenza di screziature, la presenza di carbonati e di gusci di gasteropodi terrestri. la presenza o l'assenza del calcrete sommitale, così come il suo spessore, sono parametri determinanti sul garda. il calcrete è presente su tutte le unità ad esclusione dell'unità più interna (alloformazione del garda) che ne è completamente fig. 2 sezione schematica della morena di san pietro. il colluvio affiora pochi metri sotto la cresta della morena e può provenire solo dalla cresta stessa; rappresenta perciò il suolo sommitale della morena di san pietro. schematic cross section of the san pietro moraine. colluvial deposits crop out a few meters below the top of the moraine so that these deposits could only derive from that ridge. consequently the colluvial deposits represent the soil at the top of the san pietro moraine. fig. 3 sezione schematica che mostra una successione di morene di unità diverse. il colluvio compreso nella valle tra le unità a e b non è significativo, mentre lo è il colluvio sul lato interno della morena dell'unità b. schematic section showing a sequence of moraines belonging to different units. the meaning of the colluvial deposits which lie in the valley between units a and b is not clear, but is obvious for the colluvial deposits that lies on the inner side of the moraine belonging to the unit b. a. bini & l. zuccoli 337 fig. 4 carta schematica semplificata della piana fluvioglaciale di s. tomaso brodena, a sud di lonato, completamente compresa tra morene dell'alloformazione di san pietro e ben separata dalle morene dell'alloformazione del monte forca. in figura la piana fluvioglaciale è rappresentata dall'area a righe orizzontali. semplified map of the sandur (horizontally ruled) near san tomaso-brodena, south of lonato. all the sandur lies within the endmoraines of the alloformazione di san pietro and it is completely separeted from the moraines of the alloformazione di monte forca. prime note sul rilevamento ... 338 priva. poichè l'unità appena più esterna (alloformazione di puegnago) presenta sempre un calcrete centimetrico, l'unità priva di calcrete, quindi con un profilo di alterazione completamente diverso, è lo lgm. muovendosi verso l'esterno il calcrete aumenta rapidamente di spessore sino ad interessare l'intera massa dei depositi delle unità. i valori osservati sono qui di seguito riassunti: alloformazione del garda assente alloformazione di puegnago centimetrico alloformazione di monte san pietro 15 ÷ 30 cm alloformazione di monte forca ≥ 1 m alloformazione cementazione discontinua, di monte cervo localmente completa alloformazione di monte serina cementazione completa da ultimo, ma non per importanza, viene la geometria dei depositi. ossia il mezzo di trasporto dei sedimenti, che sia acqua, ghiaccio o vento, depone i sedimenti con una geometria discreta. i depositi al margine di un ghiacciaio non possono avere qualunque andamento, ma riflettono quella che era la forma del ghiacciaio, la sua dinamica, comprendendo con questo termine sia le linee di flusso sia la distribuzione delle zone di ghiaccio stagnante, di ghiaccio caldo e di ghiaccio freddo, e la distribuzione delle acque al margine del ghiacciaio stesso. nel ricostruire l'andamento delle morene e dei corpi geologici bisogna tener conto di queste considerazioni. la geometria dei depositi è l'argomento che consente a venzo (1965) di attribuire al riss anche le morene che nel tratto orientale (1961) aveva attribuito al wurm a causa dei caratteri di alterazione. il fatto che i depositi cambino caratteristiche lungo una medesima morena o un medesimo gruppo di morene è un fatto che si è già presentato in altri anfiteatri, come quello del verbano, dove le morene orientali sottendono depositi cha hanno, per litologia, caratteristiche diverse da quelle dei depositi sottesi dalle morene occidentali. probabilmente un fatto analogo avviene anche nell'anfiteatro del garda e ha tratto in inganno venzo. unità provvisorie nella parte di anfiteatro del garda sinora rilevato, ossia dal monte luzzago a nord di puegnago sino a esenta a sud di lonato, sono state riconosciute le seguenti unità (fig. 5 e 6): alloformazione del garda (ga) l'unità è costituita da depositi glaciali, fluvioglaciali e lacustri. e' considerata come würm-moräne da habbe (1969) e come würm da venzo (1957). la superficie limite superiore è caratterizzata da un suolo spesso circa 50 cm, di colore 2.5y, privo di calcrete. lateralmente alla morena il colluvio, quando presente, è ricco di carbonati e di nicchi di gasteropodi terrestri ed è di colore 2.5y. la superficie limite inferiore è una superficie di erosione. allogruppo di polpenazze (pol) l'allogruppo è stato istituito perchè in alcune aree con scarsità di affioramenti è difficile distinguere le alloformazioni che lo costituiscono (alloformazione di puegnago e alloformazione di monte san pietro). i depositi dell'allogruppo sono considerati come würm-moräne da habbe (1969) e come riss da venzo (1957). i l riss di venzo (1957) comprende l'alloformazione di monte forca, l'alloformazione di monte cervo e tutto l'allogruppo di polpenazze, tuttavia venzo sottolinea come l'alterazione delle morene più esterne (m. soffiano) sia maggiore di quelle più interne. alloformazione di puegnago (ppu) si tratta di depositi glaciali, fluvioglaciali e lacustri. la superficie limite superiore è costituita da una superficie di erosione che decapita l'unità della parte superiore pedogenizzata. la decapitazione avviene in corrispondenza del tetto degli orizzonti calcici del suolo per cui molti affioramenti si presentano cementati a tetto per spessori di alcuni centimetri. in alcuni affioramenti è visibile la porzione basale del suolo subito al di sopra dell'orizzonte calcico. i ciottoli, esclusivamente carbonatici, sono alterati e il colore è compreso nella pagina 10yr delle tavole munsell. al di sotto dell’orizzonte calcico i clasti di natura cristallina sono arenizzati e il colore della matrice è compreso nella pagina 10yr delle tavole munsell, più raramente nella pagina 7.5yr. in alcuni affioramenti è presente, a tetto, loess limoso argilloso indurito con patine di ossidi di ferro e manganese di colore 10yr. la superficie limite inferiore è una superficie di erosione che tronca i depositi dell’alloformazione di monte san pietro. alloformazione di monte san pietro (ppi) e' costituita da depositi glaciali, fluvioglaciali, deltizi, lacustri e di versante tipo grèzes litées. la superficie limite superiore è caratterizzata da un suolo che nell'orizzonte bt ha colore da 10yr a 7.5yr e, nell'orizzonte b/c, 10yr. clasti cristallini alterati, parziale alterazione dei clasti carbonatici. orizzonte calcico sempre presente. la presenza di un resto di paleosuolo in alcuni affioramenti, indice di clima caldo, consente di suddividere l'allogruppo di polpenazze nelle due alloformazioni di puegnago e di monte san pietro. nella maggior parte degli affioramenti la superficie limite superiore è costituita da una superficie di erosione che decapita l'unità della parte superiore pedogenizzata. la decapitazione avviene in corrispondenza del tetto degli orizzonti calcici del suolo per cui molti affioramenti si presentano cementati a tetto per uno spessore che giunge sino a 30 cm. la superficie limite inferiore è una superficie di erosione. alloformazione di monte forca (sfo) e' costituita da depositi glaciali e fluvioglaciali. e' considerata come come riss ii (venzo, 1957; 1965) e come würm da habbe (1969). la superficie limite superiore è caratterizzata da un suolo in genere troncato che presenta un colore variabile tra 10yr e 7.5yr. i ciottoli a. bini & l. zuccoli 339 fig. 5 carta schematica semplificata dell'area di anfiteatro studiata. e' riportata la massima estensione delle unità. semplified map showing the maximum extension of the units in the portion of the garda amphiteatre here studied. cristallini sono arenizzati. e' presente un orizzonte cca ben sviluppato tanto da trasformare il diamicton sottostante in diamictite per spessori spesso superiori al metro. la decapitazione avviene in corrispondenza del tetto degli orizzonti calcici del suolo per cui molti affioramenti si presentano cementati a tetto. la superficie limite inferiore è una superficie di erosione. l'alloformazione di monte forca copre i diamicton delprime note sul rilevamento ... l'alloformazione di monte cervo e i loess 7.5yr a tetto di quest'ultima unità. la presenza di un paleosuolo decapitato, ma ricoperto da loess e colluvi e successivamente da ghiaie, testimonia che tra la formazione delle morene di monte serina monte cervo e di monte soffiano si è avuta pedogenesi e quindi un interglaciale, ovvero le due unità, alloformazione di monte cervo e alloformazione di monte forca sono due buone unità, hanno il rango di alloformazioni e rappresentano due distinte glaciazioni. l'unità è coperta dai depositi dell'allogruppo di polpenazze e da colluvi di colore variabile da 10yr a 5yr. i colluvi sono osservabili già alcuni metri al di sotto della cresta della morena di monte forca. alloformazione di monte cervo (sce) si tratta di depositi glaciali. e' considerata come riss i (venzo, 1957; 1965) e come riss da habbe (1969). la superficie limite superiore è una superficie di erosione che tronca il suolo originario. la decapitazione avviene in corrispondenza del tetto degli orizzonti calcici del suolo per cui molti affioramenti si presentano cementati a tetto. lo spessore della cementazione è variabile da alcune decine di centimetri a discontinua che può interessare l'intero corpo osservabile ossia per alcuni metri. essa è coperta da loess e colluvi induriti, screziati di colore 7.5yr. l'unità copre in erosione l'alloformazione di monte serina ed è coperta dall'alloformazione di monte forca (condizioni visibili in affioramento). quest'ultima unità copre anche i loess 7.5yr. la presenza di un paleosuolo decapitato, ma ricoperto da loess e colluvi e successivamente da ghiaie, testimonia che tra la formazione delle morene di monte serina monte cervo e di monte soffiano si è avuta pedogenesi e quindi un interglaciale, ovvero le due unità, alloformazione di monte cervo e alloformazione di monte forca sono due buone unità, hanno il rango di alloformazioni e rappresentano due distinte glaciazioni. i clasti cristallini sono alterati e la matrice presenta colore variabile tra 2.5y e 5yr. alloformazione di monte serina (sse) l'unità è costituita da depositi glaciali e fluvioglaciali. e' considerata come come mindel ii (venzo, 1957; 1965) e come riss da habbe (1969). la superficie limite superiore è costituita da una superficie di erosione che decapita l'unità della parte superiore pedogenizzata. la decapitazione avviene in corrispondenza del tetto degli orizzonti calcici del suolo per cui molti affioramenti si presentano cementati a tetto. lo spessore della cementazione è variabile da alcune decine di centimetri all'intero corpo osservabile ossia per alcuni metri. il suolo parzialmente conservato si osserva, in alcuni affioramenti, coperto dal diamicton dell'alloformazione di m. cervo. la presenza di questo paleosuolo decapitato testimonia che tra l'alloformazione di monte cervo e l'alloformazione di monte serina si è avuta pedogenesi e quindi un interglaciale, ovvero le due unità sono due buone unità, hanno il rango di alloformazioni e rappresentano due distinte glaciazioni. i ciottoli cristallini sono arenizzati o con cortex e la matrice presenta colori 7.5yr e 5yr. l'alloformazione di monte serina copre, in erosione, i conglomerati di cà dell'ava e la formazione di cascina colombera ed è coperta dall'alloformazione di monte cervo, da colluvi di colore 10yr÷7.5yr e da loess di colore 10yr. formazione di cascina colombera (co) unità litostratigrafica costituita dal conglomerato di ca’ dell’ava alterato. a letto l'unità passa gradualmente, con limite ad organi geologici, al conglomerato di ca’ dell’ava, mentre a tetto il limite è erosivo ed è coperto dal colluvio. la formazione di cascina colombera si presenta fortemente alterata, indurita, composta da ghiaie poligeniche immerse in un’abbondante matrice di colore 7.5yr÷10yr, ricca in argilla e limo. i ciottoli si frantumano con facilità. lo spessore dell'unità è variabile per erosione da pochi centimetri a qualche metro. conglomerato di cà dell'ava (ca) e' un'unità litostratigrafica costituita da depositi 340 fig. 6 schema dei rapporti stratigrafici nell'area di anfiteatro del garda studiato. non sono compresi in questo schema l'allogruppo di rio naviglio e il conglomerato di pisenze. la sigla pg si riferisce all'unità postglaciale. stratigraphic framework in the portion of the amphiteatre here studied. allogruppo di rio naviglio and conglomerato di pisenze are not included. pg refers to postglacial unit. a. bini & l. zuccoli glaciali e fluvioglaciali cementati. il limite superiore è graduale ad organi geologici con la formazione di cascina colombera. l'unità copre il conglomerato del castello di muscoline a nw dell'area sinora rilevata. in tutto i l territorio ri levato sono stati attribuiti al conglomerato di cà dell'ava tutti i conglomerati in facies glaciale e fluvioglaciale che costituiscono l'anima dei numerosi dossi dell'anfiteatro. in questo settore il conglomerato è fortemente eroso ed è coperto da tutte le unità più recenti. nella zona a nord (tra cà dell'ava e muscoline), si distinguono due fasi formative separate da una superficie di discontinuità (ca1 e ca2) allogruppo di rio naviglio (nav) l'allogruppo è stato istituito per comprendere tutti depositi di facies glaciale e fluvioglaciale, cementati e non cementati aff ioranti al di sotto delle alloformazioni di monte san pietro e di puegnago, sul lato interno, lungo il rio naviglio. unità di picedo (npi) costituita da depositi glaciali e fluvioglaciali induriti e glaciotettonizzati. affiora solo in due affioramenti presso picedo. il limite inferiore è ignoto, mentre a tetto è limitata da una superficie di erosione sopra la quale si trova l'alloformazione di puegnago. conglomerato del castello di muscoline (cam) ghiaia litificata, grossolanamente stratificata di petrografia omogenea esclusivamente carbonatica. forma il ripiano di muscoline e il rilievo del castello in corrispondenza dei quali affiora in tutte le incisioni vallive. secondo venzo (1957, 1965) questo conglomerato, benchè un po' più grossolano, è analogo a quello che affiora a san bartolomeo di salò e che è di età messiniana. i due conglomerati sono in realtà differenti e di conseguenza non si ritiene valida, allo stato attuale, questa correlazione e l'età attribuita al conglomerato di muscoline. il conglomerato del castello di muscoline è coperto da tutte le unità più recenti, in particolare dal conglomerato di cà dell'ava. a tetto si osserva il passaggio all'alterite sviluppata sul conglomerato. il conglomerato si presenta di colore biancastro e fragile con limite superiore ondulato a tasche. l'alterite è costituita da fini massivi ricchi in argilla (orizzonte bt) di colore 10yr6/6 e limite superiore netto erosivo. il passaggio alle alteriti e le alteriti stesse sono attualmente poco visibili in quanto le alteriti sono state oggetto di intenso sfruttamento per la fabbricazione di laterizi. allogruppo di moniga del bosco (mon) l'allogruppo comprende depositi colluviali polifasici provenienti dalle alloformazioni di monte serina, di monte cervo, di monte forca e dalla formazione di cascina colombera. costituisce parte del ferretto degli autori precedenti. il colore è compreso nella pagina 7.5yr delle tavole munsell. lo spessore può essere notevole, l'unità infatti riempie le valli tra i dossi di conglomerato di cà dell'ava. il limite con le unità sottostanti è una superficie di erosione. formazione di torre (tor) unità litostratigrafica costituita dal conglomerato di calvagese alterato. l'unità è stata denominata da venzo: morenico del mindel i, morena di fondo (1957) e morenico del mindel ii (1965). affiora a nord della località torre nell’impluvio sulla sinistra del fiume chiese, a nord di mocasina. si tratta di ghiaie alterate con livelli di sedimenti fini cementati. a letto l'unità passa gradualmente, con limite ad organi geologici, al conglomerato di calvagese, mentre il limite superiore non è stato osservato perchè coperto, ma è ragionevole supporre che l'unità sia coperta dal conglomerato di ca’ dell’ava che affiora pochi metri più in alto, spostato di circa 50 m. conglomerato di calvagese (cal) e' un'unità litostratigrafica costituita da depositi fluviali cementati. l'unità è stata denominata da venzo: ceppo poligenico del günz-mindel (1957) e anaglaciale mindel (1965). affiora solo in due impluvi sulla sinistra del fiume chiese, nei pressi di calvagese della riviera e a nord di mocasina, e nel vallone della valle. si tratta di ghiaie poligeniche, stratificate verso l’alto con immersione verso w, ben cementate. l'unità poggia sulla formazione di ponte clisi è passa gradualmente verso l'alto, con limite ad organi geologici, alla formazione di torre. formazione di ponte clisi (pc) si tratta di un'unità litostratigrafica costituita da depositi glaciali cementati. l'unità è stata denominata da venzo: morenico a ciottoloni alpini del günz ii (1957) e morenico alpino del günz iii (1965). affiora solo in due impluvi sulla sinistra del fiume chiese, nei pressi di calvagese della riviera e a nord di mocasina. alla base è presente una tillite costituita da till di alloggiamento (fini massivi con clasti carbonatici sparsi, alcuni striati e sagomati a ferro da stiro); segue una tillite costituita da till di ablazione contenente massi, quindi un’alternanza di: limi laminati, sabbie medio-grossolane laminate, ghiaie medie e sabbie e argilla parzialmente cementati. il limite inferiore è sconosciuto, il limite superiore è costituito da una superficie di erosione coperta dal conglomerato di calvagese. conglomerato di pisenze (pis) unità litostratigrafica costituita da depositi fluvioglaciali di ambiente deltizio cementati. affiora sul versante settentrionale della rocca di manerba. conclusioni il rilevamento di dettaglio di parte dell'anfiteatro del garda ha permesso di distinguere e cartografare varie unità allostratigrafiche e litostratigrafiche. i metodi utilizzati in questo rilevamento sono in parte differenti da quelli che sono stati impiegati negli anfiteatri già rilevati (bini 1997b, bini et al., 2001) a dimostrazione del fatto che non esiste una regola generale di rilevamento del quaternario continentale valida per qualunque luogo e qualunque contesto. in ogni nuova situazione che si affronta è necessario rivedere, adattare i criteri di rilevamento e metterne a punto di nuovi specifici per quel contesto. le unità che contengono depositi glaciali differenti sono sinora otto. non essendo stato rilevato l'intero anfiteatro è possibile che questo numero vari in futuro; 341prime note sul rilevamento ... del resto è noto (bini et al., 1992; bini 1997, bini et al., 2001) che le unità definitive nel ri levamento del quaternario vanno decise solo al termine del rilevamento stesso. per tali motivi non c'è da stupirsi, come invece fa minelli (1997), del fatto che venzo abbia cambiato idea dal 1957 al 1965 quando ha terminato il rilievo: il metodo di venzo è ormai superato, ma non i concetti geologici di base, per cui le conclusioni sulle unità e sull'evoluzione di un bacino sedimentario, sia esso giurassico o quaternario, si possono trarre solo al termine del rilevamento dell'intero bacino. e' comunque più probabile che non subiscano variazioni le unità interne, mentre altre unità potrebbero aggiungersi all'esterno. le glaciazioni sinora individuate secondo la definizione di richmond (1986),sono: la glaciazione garda, la glaciazione puegnago, la glaciazione monte san pietro, la glaciazione monte forca, la glaciazione monte cervo, la glaciazione monte serina; la glaciazione cà dell'ava e la glaciazione ponte clisi. riguardo al problema dell'età delle cerchie moreniche si deve evidenziare come non sia possibile una soluzione sino a che tutti i geologi, che si interessano anche solo marginalmente al quaternario, non parleranno la stessa lingua. ringraziamenti il lavoro che abbiamo svolto in questi ultimi tre anni, dal 2000 al 2003, non sarebbe stato possibile senza il contributo fondamentale dei nostri studenti: alpago daniele, amigoni edda, anselmi silvia, arpaia paolo, barilli nicola, barzaghi fiorella, bigoni paolo, bonavera mauro, bonzini maria, brioschi laura, brivio luca, colombini ivan, conti roberto, cuzzilla roberta, dell'arciprete diana, dell'orto stefano, drera rosa, felisari andrea, franciamore valeria, galli giuditta, gardoni barbara, gentile erika, gerosa michela, ghiselli alice, grassi davide, grosso davide, locatelli elena, lunghi riccardo, lupis domenico, mainardi dario, mangialetti morena, marchesi cinzia, massaro costanza, molinari michele, monti matteo, moro daniele, pagnoncelli tecla, panella antonio, pasqualino di marineo maria, pedersoli maria teresa, pitaro saverio, pomati davide, pozzi paolo, raimondi matteo, rech alberto, redaelli chiara, ronchetti maurizio, ruggiero mario, santambrogio daniela, sarti chiara, sarti ilaria, scacciante davide, scazzosi valentino, scola simone, soffritti valeria, sommariva nicola, sozzani marta, tendas antonio, turisini chiara, villa ilaria, villa laura, zambarnieri elisa. bibliografia bini a., bosi c., carraro f. e castiglioni g.b. (1992) cartografia geologica del quaternario continentale in: consiglio nazionale delle ricerche, commissione per la cartografia geologica e geomorfologica: carta geologica d'italia 1:50.000 guida al r i levamento, servizio geologico nazionale quaderni (iii) vol. 1: 67 86 bini a. (1997) problems and methodologies in the study of the quaternary deposits of the southern side of the alps southern alps quaternary geology, igcp 378 meeting, lugano ottobre 1995. geologia insubrica 2 (2): 11 20 bini a. (1997) stratigraphy, chronology and palaeogeography of quaternary deposits of the area between the ticino and olona rivers (italyswitzerland) southern alps quaternary geology, igcp 378 meeting, lugano ottobre 1995. geologia insubrica 2 (2): 21 46 bini a., felber m., pomicino n. e zuccoli l. (2001) geologia del mendrisiotto (canton ticino, svizzera): messiniano, pliocene e quaternario berichte des bundesamt für wasser und geologie / rapporti dell'ufficio federale delle acque e della geologia bwg/ufaeg 1: 459 pp cozzaglio a. (1934a) carta geologica delle tre venezie. foglio peschiera mag. acque, venezia cozzaglio a. (1934b) carta geologica delle tre venezie. foglio mantova mag. acque, venezia cozzaglio a. (1939) carta geologica d'italia. foglio brescia ufficio geologico roma cozzaglio a. (1933) note illustrative della carta geologica delle tre venezie. fogli peschiera e mantova mag. acque sezione geologica, padova cremaschi m. (1987) paleosol and vetusols in the central po plain (northen italy) a study in quaternary geology and soil developement edizioni unicopli, milano habbe k. a. (1969) die würmzeitliche vergletscherung des gardasee-gebietes freiburger geographische arbeiten 3. minelli r. (1997) i suoli dell'area morenica gardesana settore bresciano ersal penck a. e bruckner e. (1909) die alpen im eiszeitalter leipzig, bd. 3. richmond g.m. (1962) quaternary stratigraphy of the la sal mountains utah geological survey professional paper, 324: 1-103. richmond g.m. (1986) stratigraphy and chronology of glaciations in yellowstone national park in: sibrava v., bowen d.q. e richmond g.m. (eds.) quaternary glaciations in the northern hemisphere. report igcp n°24, quaternary science reviews 5(1-4): 83 98 venzo s. (1957) rilevamento geologico dell'anfiteatro morenico del garda. parte i: tratto occidentale gardone-desenzano mem. soc. it. sc. nat. e museo civ. st. nat. milano, xii (fasc. ii): 73 140. venzo s. (1961) rilevamento geologico dell'anfiteatro morenico del garda. parte ii: tratto orientale garda-adige e anfiteatro atesino di rivoli veronese mem. soc. it. sc. nat., v. 13, n. 1: 164. milano venzo s. (1965) rilevamento geologico dell'anfiteatro morenico frontale del garda dal chiese all'adige mem. soc. it. sc. nat. e mus. civ. st. nat. milano, xiv (fasc. i): 3 82. 342 ms. ricevuto l’11 maggio 2004 testo definitivo ricevuto il 1° settembre 2004 ms. received: maj 11, 2004 final text received: september 1, 2004 a. bini & l. zuccoli sess 0_retro e indice edi.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 the genus arvernoceros heintz, 1970 in italy: preliminary report carmelo petronio & luca pandolfi dipartimento di scienze della terra, , università sapienza, roma corresponding author: c. petronio <carmelo.petronio@uniroma1.it> abstract: petronio c. & pandolfi l., the genus arvernoceros heintz, 1970 in italy: preliminary report. (it issn 0394-3356, 2011) the first occurrence of the large-sized deer arvernoceros in the early pleistocene of italy is reported. this genus was found in the sites of madonna della strada and selvella (central italy). the considered remains have morphological and biometrical characters similar to those of the species a. giulii and are quite different from those of the genus eucladoceros and of the genus praemegaceros. riassunto: petronio c. & pandolfi l., il genere arvernoceros heintz, 1970 in italia: rapporto preliminare. (it issn 0394-3356, 2011) viene riportata la prima presenza in italia del cervo di grande taglia arvernoceros durante il pleistocene inferiore. questo genere è stato rinvenuto nei siti di madonna della strada e selvella (italia centrale). i resti considerati presentano caratteri morfologici e biometrici simili a quelli della specie a. giulii e sono abbastanza differenti da quelli dei generi eucladoceros e praemegaceros. key words: arvernoceros, italy, early pleistocene parole chiave: arvernoceros, italia, pleistocene inferiore we report here findings constituting some fossil remains of a large-sized deer. they have been discovered in the late villafranchian deposits (late early pleistocene) outcropping in the chiana river valley at selvella and in the wide intra-apennine basin of l’aquila, in locality madonna della strada. both the sites are localized in central italy and are referred respectively to farneta and pirro faunal unit (gliozzi et al., 1997). basing on morphological and biometrical characters, the considered remains can be referred to the genus arvernoceros: these represent the first records of this genus in italy. in fact, before the present description the most common large-sized deer of the late early pleistocene of italy were eucladoceros and praemegaceros (azzaroli & mazza, 1992; gliozzi et al., 1997; abbazzi, 2004). a limited number of specimens of the genus cervalces was also reported in northern italy (azzaroli, 1979a). the genus arvernoceros includes medium and largesized species. it is characterized by a rather conservative specific variability of antler morphology and primitive morphology of dentition, with simple p/4 and relatively long premolar series (heintz, 1970; croitor & kostopoulos, 2004). the systematic position of arvernoceros is still unclear. heintz (1970) included the genus in the megacerini tribe, and thus assumed a phylogenetic relationship with megaloceros. di stefano & petronio (2002) included arvernoceros ardei in the genus axis, and suggested, with morphological considerations, that the latter was related to a strictly similar, but more specialized form of axis shansius. croitor & stefaniak (2009) noticed strict phylogenetic relationships with the modern genus rucervus, while made & tong (2008) noted a similarity with the genus sinomegaceros. before the 1997, in europe, two species are ascribed to arvernoceros: the medium-sized a. ardei, reported in france, spain and poland during the early villafranchian (heintz, 1970; croitor & stefaniak, 2009) and the large-sized a. verestchagini, described by david (1992) and reported in moldova and probably in apollonia (grecia) (david, 1992; croitor & kostopoulos, 2004). in the 1997, kahlke indicated the remains of a large-sized deer in untermassfeld (germany; about 1 ma) in reference to the new species eucladoceros giulii. according to croitor & kostopoulos (2004), the hypothetical reconstruction of the antler, reported by kahlke (1997), was based on scant fossil fragments belonging to individuals of different ontogenetic ages. the large-sized deer from untermassfeld should be ascribed to the genus arvernoceros based on teeth, bones and some antler morphology (croitor & kostopoulos, 2004). the considered remains of the large-sized deer from madonna della strada consist of one upper molar (m1/-m2/) (msgn°376), two astragali (msgn°395 and dessr s.n.) and one metatarsus (dessr s.n.), while the remains of selvella consist of one complete metatarsus (igf14158) and one astragalus (igf14158). the upper molar shows, in occlusal view, a marked parastyle and the paracone profile has rounded central fold and a less marked metacone style. these features are different from eucladoceros; in this genus the upper molars have sharp ribs of paracone and metacone. in the upper 164 166 165 molar of madonna della strada, the protoconal fold is weakly observable; this fold is not present in p. verticornis, but is well marked in eucladoceros and p. obscurus. the posterior wing of the hypocone in madonna della strada is not bifurcated, unlike the genus eucladoceros, and the hypoconal enamel fold is not present, yet is observable in p. obscurus (azzaroli & mazza, 1992; croitor & kostopoulos, 2004; croitor, 2006). weak lingual cingula are present on the upper molar of madonna della strada while cingula are generally absent in the genus praemegaceros (croitor, 2006). in the three considered astragali the distal end of the lateral lip of the proximal trochlea, in anterior view, bends inward, forming a sort groove (fig. 1a). this feature is present in a. giulii, and is absent or less clear in eucladoceros from the various locality of upper valdarno and p. obscurus from pirro nord. also, the proximal end of the medial lip of the proximal trochlea, in medial view (fig. 1b), extends at the posterior through a long and straight edge, as in a. giulii. in all the specimens of eucladoceros from the various locality of upper valdarno, including poggio rosso, p. obscurus from pirro nord and p. verticornis from different locality it extends through a short and curved edge. also, the considered remains are dimensionally larger than eucladoceros; they are comparable with a. giulii and are smaller than a. cf. verestchagini from apollonia -1. the two metatarsi are slender than the different species of the genus eucladoceros; the diaphysis are smaller, while the distal epiphysis almost overlaps the largest eucladoceros from upper valdarno. proportionally, the considered metatarsi are comparable with the specimens of arvernoceros from untermassfeld. in the bivariate diagram of maximal length/transversal distal diameter (fig. 1c) the remain of selvella is comparable with the values of the large-sized deer from untermassfeld and is well-separated from the values of eucladoceros and praemegaceros. also, morphological features distinguish the considered metatarsi from the specimens of eucladoceros from upper valdarno. in particular, the proximal epiphysis is more developed dorso-plantarly and the lateral articular surface is more elongated. furthermore, in dorsal view, the lateral portion of the proximal epiphysis seems to be higher that the medial one and the gap between the throclee in the distal epiphysis appears more enlarged. according to the previous analysis, the remains of the large-sized deer from madonna della strada and selvella have dimensions and morphology comparable with the genus arvernoceros and in particular are similar to the specimens of a. giulii from untermassfeld; this last is larger than a. ardei and relatively smaller than a. cf. verestchagini. the presence of a. giulii in the madonna della strada and selvella sites are the fig. 1, a, b: astragalus (dessr s.n.) from madonna della strada in frontal view (a) and in medial view (b), the bar is of about 2 cm; c: bivariate diagram of metatarsi from madonna della strada (estimated minimal length) and selvella and a. giulii from untermassfeld (data from kahlke, 1997), eucladoceros from upper valdarno (data from azzaroli & mazza 1992), praemegaceros from different sites (data from azzaroli, 1979b; kahlke, 1965, 1969, 1971; abbazzi et al., 1999) and a. cf. verestchagini from apollonia-1 (data from croitor & kostopoulos, 2004). l = absolute length, dtd = distal transversal diameter. a, b: astragalo (dessr s.n.) da madonna della strada, in visione frontale (a) e mediale (b), la barra è di circa 2 cm; c: diagramma bivariato dei metatarsi di madonna della strada (lunghezza minima stimata), selvella e a. giulii di untermassfeld (dati da kahlke, 1997), eucladoceros del valdarno superiore (dati da azzaroli & mazza 1992), praemegaceros da differenti siti (dati da azzaroli, 1979b; kahlke, 1965, 1969, 1971; abbazzi et al., 1999) e a. cf. verestchagini da apollonia-1 (dati da croitor & kostopoulos, 2004). l = lunghezza massima, dtd = diametro distale trasverso. the genus arvernoceros heintz, 1970 in italy: ... 166 ms. received: testo ricevuto il first sure records of this mammal in the pleistocene of italy and the earliest in western europe. the dispersal of a. giulii from asia is probably caused by early pleistocene transformations in eastern paratethys (croitor, 2009) and its occurrence in italy can be favoured by the geographical position of the peninsula and the climate change of the late early pleistocene. arvernoceros was reported in different sites of south-eastern europe and low stands of adriatic sea level could have played a decisive role in the dispersal of this species when the climate turned progressively drier during the considered time span. however, a more detailed analysis is needed to verify this hypothesis and to better investigate the presence of this genus in italy and its relationships with the other late villafranchian deer. references abbazzi l. (2004) remarks on the validity of the generic name praemegaceros portis 1920, and an overview on praemegaceros species in italy. rend. cl. sci. fis. nat. acc. lincei s. 9, 15, 115-132. abbazzi l., croitor r. & david a. (1999) large-sized deer megaceroides obscurus (azzaroli, 1953) from eastern moldova. acta zool. cracov., 42 (3) , 377-392. azzaroli a. (1979a) on the occurrence of the cervid genus libralces in the pleistocene of italy. palaeontogr. ital., 71, 48–54. azzaroli a. (1979b) critical remarks on some giant deer (genus megaceros owen) from the pleistocene of europe. palaeontogr. ital., 71, 6-16. azzaroli a. & mazza p. (1992) the cervid genus eucladoceros in the early pleistocene of tuscany. palaeontogr. ital., 79, 43-100. croitor r. (2006) taxonomy and systematics of large -sized deer of the genus praemegaceros portis, 1920 (cervidae, mammalia). c. forsch-inst. senckenberg, 256, 91-116. croitor r. (2009) systematic position and evolution of the genus arvernoceros (cervidae, mammalia) from plio-pleistocene of eurasia. muz. olten. craiova, 25, 375-382. croitor r. & kostopoulos d.s. (2004) on the systematic position of the large-sized deer from apollonia, early pleistocene, greece. palaeontologische zeitschrift, 78, 137-159. croitor r. & stefaniak k. (2009) early pliocene deer of central and eastern european regions and inferred phylogenetic relationships. palaeontographica, 287, 139. david a. (1992) a new deer species (cervidae, mammalia) from the late pliocene deposits of moldova (in russian). bul. ac. ùtiin e din rep. moldova s. ştiinţelor chim. biol., 1, 67-68. di stefano g. & petronio c. (2002) systematic and evolution of the eurasian plio-pleistocene tribe cervini (artiodactyla, mammalia). geol. romana, 36, 311-334. gliozzi e., abbazzi l., argenti p., azzaroli a., caloi l., capasso barbato l., di stefano g., esu d., ficcarelli g., girotti o., kotsakis t., masini f., mazza p., mezzabotta c., palombo m.r., petronio c., rook l., sala b., sardella r., zanalda e. & torre d. (1997) biochrnology of selected mammals, molluscs and ostracods from the middle pliocene to the late plesitocene in italy. the state of the art. riv. ital. paleontol. stratigr., 103 (3) , 369-388. heintz e. (1970) les cervidés villafranchiens de france et d’espagne. mem. mus. nat. hist. nat. s. c sci. ter. xxii, 303 + 207. kahlke h.d. (1965) die cervidenreste aus dem tonen von voigtstedt in thüringen. paläontol. abh. a, 2 (2-3) , 381-424. kahlke h.d. (1969) die cerviden-reste aus den kiesen von süssenborn bei weimar. paläontol. abh. a, 3 (3-4) , 547-609. kahlke h.d. (1971) family cervidae. in: nikiforova, k.v. (ed.) the pleistocene of tiraspol, 137-156. stinca, kisiniev. [in russian with english summary]. kahlke h.d. (1997) die cerviden-reste aus dem unterpleistozän von untermassfeld. in: r.d. kahlke, (ed.) das pleistozän von untermassfeld bei meiningen (thüringen). monographien des römischgermanischen zentralmuzeums mainz, 40 (1), 181275. made van der j. & tong h.w. (2008) phylogeny of the giant deer with palmate brow tines megaloceros from west and sinomegaceros from east eurasia. quat. inter., 179, 135–162. c. petronio & l. pandolfi january 13, 2011 13 gennaio 2011 sess 3_14022011_edi as (3).pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 preliminary analysis of bos primigenius bojanus,1827 from avetrana (southern italy) carmelo petronio, leonardo salari & luca pandolfi dipartimento di scienze della terra, sapienza, università di roma corresponding author: c. petronio <carmelo.petronio@uniroma1.it> abstract: petronio c., salari l. & pandolfi l., preliminary analysis of bos primigenius bojanus, 1827 from avetrana (southern italy). (it issn 0394-3356, 2011) abundant remains of bos primigenius have been recovered in the early late pleistocene site of avetrana (southern italy). the remains of auroch are referred to at least 37 individuals. also, biometrical analysis of the metapodial bones of the female aurochs from avetrana gave the cue to examine the evolutive trend of the species. riassunto: petronio c., salari l. & pandolfi l., analisi preliminare di bos primigenius bojanus, 1827 di avetrana (italia meridionale). (it issn 0394-3356, 2011) resti abbondanti di bos primigenius sono stati rinvenuti nel sito di avetrana (italia meridionale), riferibile alla prima parte del pleistocene superiore. i resti di uro sono riferibili ad almeno 37 individui. inoltre, l’analisi biometria dei metapodiali degli individui femminili di avetrana ha dato lo spunto per esaminare il trend evolutivo della specie. key words: bos primigenius, avetrana, early late pleistocene, evolutive trend parole chiave: bos primigenius, avetrana, pleistocene superiore iniziale, trend evolutivo the auroch, bos primigenius object of the present study, was found in a karst cavity near avetrana, in the south-eastern area of taranto (apulia, southern italy) (sardella et al., 2005; petronio et al., 2008). the karst filling is rich in bone remains and, on the base of the faunal assemblage, petronio et al. (2008) refer the deposit to the early late pleistocene (melpignano faunal unit). the auroch is the best represented species in the site of avetrana. except for a limited number of elements, which are referable to young subjects, almost the whole of the bones is attributable to adult and subadult specimens. the upper and lower teeth are the most recurrent remains, and on the whole they are in very good condition. the tooth and bone remains are in total referred to at least 37 individuals: four calves of less two years old, five young individuals of just over two years and at least 28 adult individuals with upper and lower teeth (particularly the third lower molar was considered) in different stage of attrition. both the principal component analysis (pca) of the metapodial bones (fig. 1a) that the howard coefficients show that the aurochs of avetrana are predominantly females. solely one intact metatarsus and a few distal portions of metacarpus can be referred to males. the estimated withers height shows a population of auroch with a mean height of about 158.7 cm (153.5 cm from tibia, between 151.4 and 168.5 cm from metacarpus and between 153.5 and 165.8 cm from metatarsus) and 156.9 cm considering the females only. the analysis of biometrical characters of the b. primigenius metapodial bones from avetrana gave the cue to examine the evolutive trend of the species in southern europe, from the middle pleistocene to holocene. to compare the data of the metapodial bones from avetrana with the other from the different sites of southern europe, we have excluded the males. this fact is due to the sexual dimorphism of the species that can alter the results of the diagrams. the box plot relative to the greatest length of the metacarpus (fig. 1b) show the dimensional trend of the different female populations in the considered time spans. from left to right are reported six chronological intervals from the first occurrence of the species (middle pleistocene, mpl0) to holocene. as show in the box plot, the greatest length of the metacarpus has a general increase during the late middle pleistocene (mpl1), with a maximum in correspondence to the early late pleistocene (lpl1, represented by the sites of avetrana and melpignano). an opposite trend is recognized from the upper late pleistocene (lpl2) to holocene. the same tendency is recognized even for the distal transverse diameter of the metacarpus (fig. 1c). as for the greatest length, the maximum point is recorded in correspondence to the lpl1 (only avetrana). what has been shown for the metacarpus, it’s visible for the metatarsus in the box plot concerning the greatest length (fig. 2d) (lpl1 is represent only by avetrana). furthermore, a general change in the shape of the metapodial bones is observable. in particular, during its first occurrence (mpl0), the species is characterized by a “clepsydra” shape of these bones. the two epiphysis, and in particular the distal epiphysis, seem to be more developed than the diaphysis. the same 167 – 169 167 shape of the middle pleistocene (mpl0) is recognized even during the holocene. during the mpl1, mpl2 and lpl1, instead, the metapodial bones seem to have a more “columnar” shape. according to some authors (petronio et al., 2008; degerbøl & fredskild 1970; brugal, 1985; cerilli & petronio, 1992), the auroch is characterized by a relative decrease in size during the late pleistocene and the holocene. however, the marked sexual dimorphism of this species has been not well considered for the analysis of the evolutive trend. this fact has the consequence to hide the effective decrease or increase in size of the different populations during the time. in the present study, the comparative analysis of the explained diagrams allows to recognize a trend in the dimensional variations of the female aurochs. in this trend, we can justified the small-sized aurochs of the middle pleistocene with the presence in southern europe of a cool climate. in fact, the first occurrence of the species in europe, reported in the sites of venosa and rome gra km 2 (southern and central italy) (caloi & palombo, 1979, 1986), are related with the mis 16 and 14 (about 650-550 ky) characterized by a temperate-cool climate. the large-sized aurochs of the latest middle pleistocene and especially the early late pleistocene can be related with a temperate-warm climate, as soon as the decrease in size of the upper late pleistocene with the climatic deteriorations of the last glacial event. also, considering the presence/absence of the genus bison, and the increase of human presence, fig. 1, a:  pca of metacarpus from avetrana (cross) and males (square) and females (circle) from different pleistocene sites of europe; b, c, d: box plot for the greatest length (b) and distal breadth (c) of the metacarpi and the greatest length of metatarsi (d) from avetrana and from different sites of europe (data from requate, 1957; stampfli, 1963; flerow & reshetov, 1972; gerber, 1972; altuna, 1974; caloi & palombo, 1979; descombes, 1980; janossy & vörös, 1981; campy et al., 1983; brugal, 1985; vörös, 1987; tuffreau et al., 1995 and taken by the authors). mpl0 = about 650-500 ky; mpl1 = about 480-300 ky; mpl2 = about 300-200 ky; lpl1 = about 125-0,80 ky; lpl2 = about 75-20 ky. a: pca dei metacarpi di avetrana (croce) e dei maschi (quadrato) e delle femmine (cerchio) di differenti siti del pleistocene dell’europa; b, c, d: box plot della lunghezza massima (b) e del diametro distale (c) dei metacarpi e della lunghezza massima dei metatarsi (d) di avetrana e di differenti siti dell’europa (dati da requate, 1957; stampfli, 1963; flerow & reshetov, 1972; gerber, 1972; altuna, 1974; caloi & palombo, 1979; descombes, 1980; janossy & vörös, 1981; campy et al., 1983; brugal, 1985; vörös, 1987; tuffreau et al., 1995 e presi dagli autori). mpl0 = circa 650-500 ma; mpl1 = circa 480-300 ma; mpl2 = circa 300-200 ma; lpl1 = circa 125-0,80 ma; lpl2 = circa 75-20 petronio c., salari l. & pandolfi l. 168 ms. received: testo ricevuto il we have notice some correlations with the variations in size of the aurochs. in particular, during the first occurrence of the bos, in southern europe the presence of bison schoetensacki is very relevant. this last species disappears during the late middle pleistocene, when the aurochs increase in size. in the upper late pleistocene, the climatic deterioration and the extension of the steppe environment favour the increase of presence of bison priscus in southern europe, factors that can be compete to the decrease in size of b. primigenius. during the second pleniglacial stage and the holocene, the affirmation of human presence in southern europe can be the prevailing factors in the progressive rarefaction and the decrease in size of the aurochs. during this time span, auroch has dimensions and proportions similar to that of the middle pleistocene. the small size of these specimens could therefore be attributable also to a selection made by human beings according to their dietary and/or hunting preferences. references altuna j. (1974) hallazgo de un uro (bos primigenius boj) en la sierra de gibijo (alava). estudio de su esqueleto y de la fauna asociada al mismo. munibe, 26, 27-51. brugal j.p. (1985) le bos primigenius boj., 1827 du pléistocène moyen des grottes de lunel-viel (hérault). bull. mus. d’anthropol. préhistor. monaco, 28, 7-62. caloi l. & palombo m.r. 1979) la fauna quaternaria di venosa: bovidi. boll. serv. geol. it., 100, 101-140. caloi l. & palombo m.r. (1986) resti di mammiferi in livelli del pleistocene medio inferiore affioranti al km 2 del g.r.a. (roma). boll. serv. geol. it., 104, 141-156. campy m., chaix l., eicher u., mouthon j., richard h. & urlacher j.p. (1983) l’aurochs (bos primigenius boj.) d’etival (jura, france) et la séquence tardi et postglaciaire sur les plateaux jurassiens. rev. paléobiol., 2 (1), 61-85. cerilli e. & petronio c. (1992) biometrical variations of bos primigenius bojanus, 1827 from pleistocene to holocene. “ongules/ungulates 91” proc. intern. symp., toulouse, 37-42. degerbøl m. & fredskild b. (1970) the urus (bos primigenius bojanus) and neolitic domesticated cattle (bos taurus domesticus linnè) in denmark, with a revision of bos-remains from the kitchen middens. zoological and palynological investigations. biolog. skrifter, 17 (1), 1-234. descombes j.-c. (1980) la première faune rissienne de la basse vallée de la seine. implications biostratigraphiques et paleoecologiques. these 3eme cycle, univ. de poitiers. flerow c.c & reshetov v.j. (1972) fossil bison and bos from stranska skala. anthropos (praha). studia musei moraviae, 20 (12), 177-179. gerber s.p. (1972) la faune des grandes mamimiferees du würm ancien dans le sud de la france. ph.d. thesis, univ. provence. jánossy d. & vörös i. (1981) pleistozäner skelettfund der ures (bos pimigenius bojanus) von nagybajom (ungarn). frag. mineralog. palaeontol., 10, 79-96. sardella r., bedetti c., bellucci l., conti n., coppola d., di canzio e., pavia m., petronio c., petrucci m. & salari l. (2005) the late pleistocene vertebrate fauna from avetrana (taranto, apulia, southern italy): preliminary report. geo.alp, 2, 25-29. petronio c., bellardini f., arzarello m., bedetti c., bellucci l., cipullo a., di stefano g., pandolfi l., pavia m., petrucci m., sardella r. & salari l. (2008) the deposit of the late pleistocene from avetrana (taranto, southern italy): biochronology and palaeoecology. il quater., 21(2), 409-422. requate h. von (1957) zur naturgeschichte des ures, bos primigenius, nach schädel-und skelettfunden in schleswig-holstein. zeitsch. tierzücht. züchtungsbiol., 70, 297-338. stampfli h. r. (1963) wisent bison bonasus (linné, 1758), ur, bos primigenius bojanus, 1827, und hausrind, bos taurus linné, 1758. in: j. boessneck, i.p. jequier & h.r. stampfli (eds) seeberg burgäschisee-süd. die tierreste. acta bernensia, 2 (3), 117-196. tuffreau a., antoine p., chase p., dibble h., ellwood b., kolfschoten t. van, lamotte a., laurent m., mcpherron s., moigne a.m. & munaut a. (1995) le gisement acheuléen de cagny-l'epinette (somme). bull. soc. préhistor. franç., 92, 169-191. vörös i. (1987) an aurochs (bos primigenius boj.) skeleton from the mesolithic peatbogs at kecel rózsaberek. folia archaeol., 38, 65-88. preliminary analysis of bos primigenius bojanus ... january 13, 2011 13 gennaio 2011 january 13, 2011 13 gennaio 2011 impaginato atti 11.. iinnttrroodduuzziioonnee il suolo, trovandosi all'interfaccia fra litosfera e biosfera, risente profondamente dei processi che alterano l'equilibrio di entrambe, registrandone gli effetti sotto forma di figure permanenti, analizzabili e riconoscibili mediante determinate tecniche analitiche. pertanto, esso può divenire un importante indicatore delle variazioni ambientali che sono avvenute a partire dal pliocene superiore, quando l’area mediterranea fu interessata da fluttuazioni climatiche che produssero una alternanza tra condizioni subtropicali e climi oceanici (cremaschi, 1992). in particolare, per quanto riguarda l ’area prealpina, un classico esempio di questa situazione, è dato dalle terre rosse1, ossia paleosuoli evolutisi su substrati calcarei in condizioni subtropicali mediterranee (pre-glaciali o interglaciali), successivamente troncati da processi connessi al deterioramento climatico durante le diverse fasi glaciali del pleistocene. tali paleosuoli, ove si trovino legati a superfici topografiche il quaternario italian journal of quaternary sciences 1155(1), 2002, 131-140 ppaalleeoossuuoollii ttiippoo tteerrrraa rroossssaa aall mmaarrggiinnee pprreeaallppiinnoo.. iill ccaassoo ddii ssttuuddiioo ddeell mmoonnttee ccaassttoo ((vvaall ssaabbbbiiaa - bbrreesscciiaa)) ll.. ttrroommbbiinnoo11 && ff.. ffeerrrraarroo22 1cnr centro studio geodinamica alpina quaternaria via mangiagalli 34, 20133 milano 2università degli studi di milano dipartimento di scienze della terra, via mangiagalli 34, 20133 milano riassunto paleosuoli tipo terra rossa al margine prealpino. il caso di studio del monte casto (val sabbia brescia). l’area della val sabbia, nel suo tratto prealpino, è caratterizzata dalla presenza di una paleosuperficie su cui si sviluppano suoli di tipo terra rossa, spesso costituiti da coltri colluviate e, solo in particolari situazioni, conservati in posto. il profilo in esame è stato identificato e descritto sulle pendici del monte casto, un piccolo rilievo calcareo che raggiunge i 400 m di quota. il profilo è costituito da due unità pedologiche distinte che vanno a formare un profilo composito: l’unità profonda è un paleosuolo fersiallitico in posto, tipo terra rossa, mentre quella superficiale mostra le caratteristiche di una successione di più coltri di loess pedogenizzate. le due unità sono state distinte in base alle loro caratteristiche micromorfologiche, chimiche e fisiche, e attraverso parametri e indici che ne hanno evidenziato il diverso grado di sviluppo morfologico e di espressione della pedogenesi: conseguenze, queste ultime, di un profondo cambiamento ambientale che ha interessato l’area in esame durante la sua storia geologica più recente. abstract terra rossa paleosols on the prealpine border. the study case of mount casto (val sabbia, brescia northern italy). the prealpine reach of the val sabbia is characterised by the presence of a paleosurface strictly associated to the development of terra rossa type soils. they are often constituted by colluviated blankets of soil material and, only in particular situations, preserved in place. the described soil profile has been identified on the slopes of mount casto (a limestone plateau 400 m high). the profile is composed of two different pedologic units: the deeper one is a terra rossa fersiallitic paleosol in place, while the upper one is a soil developed from some loess blankets. the two units can be identified on the basis of their micromorphological, chemical and physical characteristics and, above all, using indexes and parameters enhancing their different degree of morphological development and of pedogenetic expression; the latter due to a paleoenvironmental change affecting the study area during its recent geological history. parole chiave: terra rossa, paleosuolo, micromorfologia del suolo, analisi elementi maggiori, italia settentrionale. key-words: terra rossa, paleosol, soil micromorphology, major elements analysis, northern italy. 1 non potendo citare in maniera adeguata oltre 150 anni di dibattito scientifico sulla terra rossa (in italiano nel testo zippe, 1853), per quanto riguarda la definizione di terra rossa si rimanda a una recente sintesi sui suoli rossi mediterranei di yaalon (1997), secondo cui il termine terra rossa viene utilizzato più o meno rigorosamente, per indicare i suoli rossi superficiali o poco profondi, che si sviluppano sui calcari in area mediterranea. stabili e non siano sepolti da una coltre di sedimenti sufficientemente spessa da isolarli definitivamente dalla superficie, sono soggetti a fenomeni pedogenetici in equilibrio con il clima attuale ed estranei alle prime fasi del loro sviluppo (cremaschi, 1987). 22.. mmaatteerriiaallii ee mmeettooddii la descrizione di campagna del profilo è stata effettuata attenendosi agli schemi suggeriti da hodgson (1976). il colore dei vari orizzonti e di eventuali screziature è stato determinato utilizzando le tavole munsell ® (1994). la designazione degli orizzonti è stata scelta in base alle keys to soil taxonomy (soil survey staff, 1990). i campioni per le analisi sono stati prelevati sia come indisturbati, sia per le analisi quantitative. le analisi pedologiche di routine sono state svolte seguendo i criteri generali proposti da avery e bascomb (1974) e da gale e hoare (1991). le analisi granulometriche sono state condotte per vagliatura e aerometria. la determinazione quantitativa del ferro estraibile ha previsto l’impiego di soluzioni di ditionito citrato, di ammonio ossalato e di sodio pirofosfato. la separazione dei minerali pesanti è stata effettuata su materiale di granulometria compresa tra 63 µm e 180 µm, preventivamente decarbonatato e deferrificato, utilizzando, come liquido pesante, il metatungstato di sodio, preparato a densità 2.9 g/cm3. per l’analisi geochimica degli elementi maggiori sono state selezionate le frazioni granulometriche più fini, precisamente: limo grossolano (coarse 63 µm 31.2 µm), limo medio (medium 31.2 µm 11 µm), limo fine + argilla (fine inferiori a 11 µm). la dissoluzione del substrato carbonatico, campionato alla base del profilo è avvenuta per immersione in bagno di acido acetico (99-100%) per oltre 2 mesi. sui campioni così preparati è stata condotta un’analisi geochimica attraverso la spettrometria per fluorescenza ai raggi x e spettrofotometria ad assorbimento atomico, al fine di determinare la composizione percentuale degli ossidi degli elementi maggiori e in parti per milione dello zirconio. per quanto riguarda la descrizione micromorfologica, le osservazioni sono state condotte secondo i canoni proposti nel handbook for soil thin section description (bullock et al., 1985). talora, nel corso della discussione è stata parzialmente utilizzata la terminologia del sistema descrittivo proposto da brewer (1964). 33.. iinnqquuaaddrraammeennttoo ggeenneerraallee il monte casto (fig. 1) è un piccolo rilievo che raggiunge i 400 m di quota, costituito da calcare della “corna”, ossia calcare compatto, di colore bianco avorio, giallo grigio, stratificato con strati potenti, a volte indistinti, del triassico superiore giurassico inferiore (definizione di curioni, 1877). la sommità del monte casto, come quella di altri rilievi presenti nell’area, è interessata dalla presenza di 132 fig. 1 carta topografica dell’area e localizzazione del profilo. topographic map and profile location. l. trombino & f. ferraro superfici a debole energia di rilievo: dal punto di vista geomorfologico esse sono i lembi di un penepiano tardo terziario, smantellato a seguito di fenomeni tettonici (chardon, 1975). su una di tale paleosuperficie si sviluppa un paleosuolo di tipo terra rossa (chardon, 1975), costituito da coltri sottili e/o colluviate, solo in particolari situazioni conservato in posto per spessori superiori al metro; spesso la terra rossa risulta coperta da depositi loessici di spessore variabile. per quanto riguarda l’evoluzione quaternaria della val sabbia, essa risulta essere stata interessata da varie fasi di espansione glaciale: riferendosi alla interpretazione fornita da chardon (1975), durante la sua massima avanzata il ghiacciaio della val sabbia sarebbe giunto fino all’altezza di barghe (pochi chilometri a monte dell’area studiata), mentre autori precedenti, quali venzo (1965), identificano depositi morenici anche più a valle del sito, nella zona di clibbio. 44.. ccaarraatttteerriizzzzaazziioonnee ddeell pprrooffiilloo 44..11.. ddeessccrriizziioonnee il profilo è stato descritto sulla parete di una cava abbandonata, che incide il versante nord occidentale del rilievo, non lontano dalla sua sommità. la superficie di campagna si trova ad una quota di 370 m s.l.m. e la copertura vegetale è essenzialmente costituita da robinia pseudoacacia. gli orizzonti identificati sono (fig. 2): o 0 20 cm, lettiera e orizzonte organico bw1 20 45 cm, 7.5 yr 6/6 (giallo rossastro), franco limoso argilloso, aggregazione poliedrica angolare minuta debolmente sviluppata, poliedri moderatamente deboli, presenza di un livello organico nei pressi del limite superiore, limite inferiore diffuso con bw2 45 100 cm, 7.5 yr 5/6 (giallo rossastro), come il precedente, eccetto aggregazione moderatamente sviluppata, rari rivestimenti di argilla sulla superficie dei poliedri, presenza di aggregati subarrotondati di materiale argilloso, limite graduale con 2bt1 100 135 cm, 5 yr 5/6 (rosso giallastro), franco argilloso, aggregazione poliedrica angolare fortemente sviluppata, poliedri resistenti, presenza di rivestimenti di argilla e di noduli e rivestimenti di fe-mn, limite diffuso con 2bt2 135 200 cm, 5 yr 5/8 (rosso giallastro), come il precedente eccetto argilloso, limite chiaro e irregolare con il substrato. 44..22.. ggrraannuulloommeettrriiee le curve granulometriche cumulative (fig. 3) consentono una precisa caratterizzazione degli orizzonti del profilo. in particolare, le curve degli orizzonti bw1 e bw2 mostrano un andamento che ricade nel campo compreso tra la curva del loess fresco e quella del loess alterato, queste ultime costruite da cremaschi (1987) sulla base di 70 campioni prelevati ai margini prealpino ed appenninico. per quanto riguarda gli orizzonti 2bt1 e 2bt2, l’argilla diviene la frazione granulometrica dominante; nell’orizzonte 2bt1 anche il contenuto in sabbia fine e molto fine non è trascurabile. 44..33.. mmiiccrroommoorrffoollooggiiaa in sezione sottile l’orizzonte bw1 è caratterizzato da aggregati poliedrici, separati da numerosi vuoti planari (fig. 4/a). la massa di fondo è costituita da grani di 133 fig. 2 il profilo del monte casto. mount casto profile. quarzo e lamelle di mica delle dimensioni massime rispettivamente della sabbia media e della sabbia fine. la frazione fine è costituita da una massa bruno giallastra, da nebulosa a maculata, costituita da argilla e grani minerali della dimensione del limo, questi ultimi inducono una b-fabric cristallitica. nella parte superiore della sezione sottile sono presenti resti vegetali solo parzialmente decomposti (fig. 4/b), mescolati ad aggregati granulari di piccole dimensioni. infine, per quanto riguarda le figure pedologiche, esse sono costituite essenzialmente da noduli e impregnazioni amorfe di ferro manganese. da un punto di vista micromorfologico, l’orizzonte bw2 è abbastanza simile al bw1: la microstruttura è sostanzialmente identica, così come sono corrispondenti le caratteristiche mineralogiche della frazione fine e grossolana, ad esclusione della presenza di alcuni frammenti subarrotondati di selce con dimensioni superiori ai 2 mm, di probabile provenienza esterna. i resti vegetali sono assenti, mentre sono stati descritti aggregati subarrotondati di argilla rossastra, interpretabili come pedorelitti (brewer, 1964 fig. 4/c). infine, per quanto riguarda le figure pedologiche, oltre a quelle amorfe, sono presenti rari frammenti arrotondati di argilla birifrangente (papulae, brewer, 1964 fig. 4/d). l’orizzonte 2bt1 si differenzia molto bene da quelli descritti in precedenza. la sua massa di fondo è caratterizzata dalla presenza di aggregati poliedrici separati da vuoti planari (fig. 4/e): lo stesso tipo di vuoti, ma più sottili, disloca ulteriormente gli stessi poliedri. la frazione grossolana è costituita da scarsi grani di quarzo e scaglie di mica, con rari frammenti di selce. la frazione fine è costituita da una massa rossa di argilla e ossidi di ferro, opaca, a b-fabric da maculata a striata (fig. 4/f). le figure pedologiche tessiturali sono costituite da rivestimenti di argilla rosso giallastri, mentre quelle amorfe da noduli di ferro manganese della dimensione massima della sabbia grossolana. paleosuoli tipo terra rossa ... l’orizzonte 2bt2 mostra le stesse caratteristiche micropedologiche del precedente, eccezion fatta per un minore contenuto in costituenti minerali grossolani. per una descrizione più dettagliata delle sezioni sottili si rimanda all’appendice. 44..44.. aannaalliissii cchhiimmiiccaa i risultati ottenuti dall’analisi degli elementi maggiori e dello zirconio (tab. 1), condotti sulle frazioni granulometriche limose e argillosa dei principali orizzonti del profilo e sul residuo insolubile prodotto per dissoluzione dei carbonati del substrato in acido acetico, permettono una ulteriore caratterizzazione delle entità pedogenetiche che costituiscono il profilo del monte casto. una prima osservazione riguarda la differenza esistente tra la composizione della coppia di orizzonti bw1 bw2 rispetto al 2bt1, quest’ultimo campionato verso il suo limite inferiore, in modo da essere rappresentativo dell’intera porzione profonda del profilo; l’orizzonte 2bt1, infatti, mostra un tenore in silicio mediamente più basso, un contenuto in alluminio e ferro superiore, ed un moderato quantitativo di calcio. d’altro canto, sempre dal punto di vista chimico, il materiale (o i materiali) da cui si è sviluppato il profilo non sembra essere corrispondente al residuo insolubile della dissoluzione del calcare: quest’ultimo, infatti risulta molto più ricco in silice (resistente all’alterazione) rispetto agli ossidi degli altri elementi chimici (cfr. macleod, 1980; olson et al., 1980; frolking et al., 1983; vanmechelen et al., 1993). alla luce di questa 134 fig. 3 curve granulometriche cumulative degli orizzonti del profilo, confrontate con le curve teoriche del loess fresco ed alterato (modificato da cremaschi, 1987). grain size cumulative curves of the profile horizons in comparison with the fresh loess and weathered loess curves (modified from cremaschi, 1987). ssiioo22 aall22oo33 ffee22oo22 mmnnoo ttiioo22 pp22oo55 mmggoo nnaa22oo ccaaoo kk22oo zzrroo22 bb11 - cc 69.00 13.29 3.96 0.08 2.47 0.04 0.47 1.12 0.17 2.06 351 bb11 - mm 66.02 15.66 4.54 0.02 2.63 0.06 0.42 0.91 0.53 2.60 583 bb11 - ff 47.51 24.66 7.88 0.09 2.57 0.17 1.14 0.30 0.37 2.46 431 bb22 - cc 63.50 16.79 4.91 0.10 2.53 0.02 0.55 1.75 0.18 2.49 376 bb22 - mm 60.35 18.45 5.65 0.00 2.61 0.04 0.54 0.73 0.37 2.62 518 bb22 - ff 49.68 23.93 7.65 0.08 2.49 0.16 1.11 0.29 0.44 2.38 446 22bbtt11 - cc 50.10 22.51 8.52 0.06 2.53 0.09 1.08 0.62 0.28 2.21 334 22bbtt11 - mm 54.04 20.43 7.29 0.09 2.58 0.06 1.03 0.61 0.85 2.26 353 22bbtt11 - ff 46.45 23.97 7.57 0.10 2.57 0.10 1.51 1.16 0.66 2.94 315 rreessiidduuoo 67.62 7.39 2.26 0.02 1.75 0.04 0.15 0.14 0.39 0.45 168 tab. 1 composizione elementale degli orizzonti: valori espressi in percentuale eccetto zro2 in ppm, h2o non mostrata (c = coarse; m = medium; f = fine). elemental composition of the horizons: values in percentage, zro2 in ppm, h20 not showed (c = coarse; m = medium; f = fine). l. trombino & f. ferraro mancata corrispondenza chimica tra orizzonti superficiali e orizzonte profondo, e tra quest’ultimo ed il residuo insolubile, è possibile ipotizzare che l’intero profilo sia stato interessato da apporti di materiale alloctono, in quantità, tempi diversi e proveniente da più sorgenti. 44..55.. aannaalliissii ddeeii mmiinneerraallii ppeessaannttii la determinazione dell’assemblaggio dei minerali pesanti fornisce un elemento di differenziazione tra le due porzioni del profilo, sia da un punto di vista mineralogico, sia per quanto riguarda il livello di alterazione raggiunto (tab. 2). la coppia di orizzonti bw1 e bw2 mostra una composizione mineralogica drasticamente dominata dagli anfiboli (59% e 45%) che, aggiunti ai pirosseni e agli epidoti, portano il totale dei minerali poco resistenti all’alterazione al 75% (bw1) e al 63% (bw2). le specie mineralogiche più stabili (zircone, tormalina e rutilo), al contrario, presentano un contenuto del 7% circa per entrambi gli orizzonti. la prima coppia di orizzonti è anche caratterizzata dalla presenza esclusiva di cianite e clorite. la situazione cambia nettamente con l’orizzonte 2bt1, che mostra un contenuto in anfiboli pari al 25%, un totale di minerali poco stabili dell’ordine del 52% ed un quantitativo di zircone, rutilo e tormalina più che doppio rispetto agli orizzonti precedenti. dunque, due differenti mineralogie si manifestano nel medesimo profilo, con una alterazione crescente nel senso della profondità. infatti l’orizzonte bw2 risulta lievemente più alterato del soprastante bw1, mentre l’orizzonte 2bt1 è più alterato di entrambi i precedenti. 55.. ggllii iinnddiiccii ccaallccoollaattii i dati ricavati dalle descrizioni e dalle analisi condotte sui singoli orizzonti possono essere utilizzati, oltre che per un confronto diretto tra i singoli parametri, 135 a b d f c e fig. 4 il profilo del monte casto in sezione sottile: a) orizzonte bw1, massa di fondo (ppl 16x); b) orizzonte bw1, resti vegetali (ppl 25x); c) orizzonte bw2, pedorelitto (ppl 25x); d) orizzonte bw2, papula (xpl 400x); e) orizzonte 2bt1, massa di fondo (ppl 25x); f) orizzonte 2bt1, massa di fondo (xpl 25x). mount casto profile in thin section: a) horizon bw1, groundmass (ppl 16x); b) horizon bw1, vegetal fragments (ppl 25x); c) horizon bw2, pedorelict (ppl 25x); d) horizon bw2, papula (xpl 400x); e) horizon 2bt1, groundmass (ppl 25x); f) horizon 2bt1, groundmass (xpl 25x). paleosuoli tipo terra rossa ... orizzonti dell’unità profonda rispetto a quelli superficiali, per i quali il grado di arrossamento è moderato (fig. 6). 55..33.. iinnddiiccee ddeell ffeerrrroo aattttiivvoo l’indice del ferro attivo, calcolato secondo rhodes e sutton (1978) e secondo arduino et al. (1984) mostra i seguenti valori: oorriizzzzoonnttee rrhhooddeess ee ssuuttttoonn aarrdduuiinnoo eett aall.. bw1 0.84 7.63 bw2 0.82 9.52 2bt1 0.73 15.19 2bt2 0.71 16.67 anche per una elaborazione più complessa, attraverso la determinazione di appropriati indici che forniscono ulteriori informazioni sullo stato di evoluzione dei suoli. 55..11.. uunniiffoorrmmiittàà ddeell ppaarreenntt mmaatteerriiaall la valutazione di uniformità del parent material è lo strumento “quantitativo” per identificare le principali discontinuità che interessano il profilo (per una sintesi su questo argomento si rimanda a vidic, 1994). a tale scopo viene utilizzato il confronto dei rapporti tessiturali, chimici e mineralogici degli orizzonti del suolo (fig. 5). il primo parametro utilizzato in questa sede è il rapporto tra il contenuto in limo e quello in sabbia dei vari campioni (busacca e singer, 1989). i risultati ottenuti mostrano una variazione di tale rapporto tra l’orizzonte 2bt1 e la parte superiore del profilo. infatti, gli orizzonti bw1 e bw2 (rappresentati graficamente fuori scala) hanno un indice pari a 5.60 e 4.16 rispettivamente, mentre il 2bt1 raggiunge appena l’1.23. la lieve differenza esistente tra i due orizzonti bw sembra dipendere dalla maggiore alterazione di bw2. il primo dei parametri chimici utilizzati è la distribuzione del titanio all’interno del profilo (brewer, 1964). data la costanza dei valori misurati per questo elemento, tale indice non fornisce nessuna informazione sulla presenza di discontinuità, anzi sembrerebbe indicare una sostanziale uniformità del profilo. al contrario, gli altri indici chimici utilizzati (busacca e singer, 1989) sono indicativi della disomogeneità esistente tra l’orizzonte 2bt1 e quelli soprastanti. sia il rapporto calcio / zirconio, sia quello ferro / zirconio presentano infatti una brusco incremento in corrispondenza di tale orizzonte. questo andamento pare condizionato da variazioni che interessano tutti e tre gli elementi considerati, ovviamente con intensità e segno che sono specifiche. infine, anche gli indici mineralogici confermano la separazione tra l’orizzonte 2bt1 e la porzione soprastante del profilo: per quest’ultimo orizzonte infatti, gli indici calcolati secondo brewer2 (1964) e cremaschi3 (1978) mostrano valori tre quattro volte superiori a quelli degli orizzonti bw1 e bw2. è dunque possibile concludere che i l profi lo del monte casto sia interessato da una disomogeneità chimica e mineralogica, condizionata quindi da una diversa litologia nel parent material, coincidente con il limite superiore dell’orizzonte 2bt1, che per altro, corrisponde a una discontinuità nell’organizzazione macro e microscopica del profilo. 55..22 iinnddiiccee ddii aarrrroossssaammeennttoo l’indice di arrossamento (torrent et al., 1980) riferito al profilo del monte casto evidenzia la maggiore rubefazione degli 136 2 zircone + tormalina –––––––––––––––– prosseni + anfiboli 3 zircone + tormalina + ossidi di titanio ––––––––––––––––––––––––––––– pirosseni + anfiboli + epidoti bb11 bb22 22bbtt11 ttrraassppaarreennttii 80.5 61.7 69.4 ooppaacchhii 19.5 38.3 30.6 zziirrccoonnee 1.9 4.7 7.9 ttoorrmmaalliinnaa 5.1 0.7 4.6 rruuttiilloo 0.0 1.3 2.6 ppiirroosssseennii 4.5 6.0 5.9 aannffiibboollii 58.6 44.7 25.0 eeppiiddoottii 11.5 12.0 21.1 ggrraannaattii 5.1 7.3 13.2 ssttaauurroolliittee 1.9 2.7 3.9 ssffeennee 0.6 1.3 4.6 cciiaanniittee 1.3 4.0 0.0 cclloorriittee 2.5 2.7 0.0 bbaarriittee 0.6 1.3 2.0 aallttrrii 0.0 1.3 0.7 aalltteerraattii 5.7 10.0 8.6 tab. 2 assemblaggio dei minerali pesanti del profilo del monte casto (valori espressi in percentuale). heavy minerals composit ion of mount casto profile (values in percentage). fig. 5 valutazione di uniformità del parent material del profilo del monte casto [rapporto limo / sabbia da busacca e singer (1989); contenuto in tio2 da brewer (1964); rapporti cao / zro2 e fe2o3 / zro2 da busacca e singer (1989); indici mineralogici da brewer (1964) e cremaschi (1978)]. parent material uniformity of mount casto profile [silt / sand ratio, from busacca and singer (1989); tio2 content, from brewer (1964); cao / zro2 and fe2o3 / zro2 ratios, from busacca and singer (1989); mineralogical indexes from brewer (1964) and from cremaschi (1978)]. l. trombino & f. ferraro è evidente una chiara differenziazione tra le due unità che compongono il profilo, con un livello di maggiore alterazione pedogenetica per quanto riguarda gli orizzonti più profondi. 55..44.. llaa ppeerrcceennttuuaallee rreessiidduuaa ddeeggllii eelleemmeennttii oorriiggiinnaarrii partendo dai dati ottenuti attraverso le analisi in fluorescenza ai raggi x e assorbimento atomico è anche possibile determinare le variazioni delle quantità relative dei singoli elementi avvenute durante la pedogenesi, attraverso il calcolo della percentuale residua degli elementi originari4 (percentage of element remaining busacca, 1982; busacca et al., 1988; busacca e singer, 1989). in questo caso, la percentuale residua degli elementi originari è stata calcolata riferendosi alla composizione chimica del residuo insolubile della dissoluzione del calcare come parent material ed utilizzando lo zirconio come elemento indice. alla luce del fatto che il profilo si è sviluppato a partire da almeno due distinti materiali, come determinato dalla valutazione di uniformità del parent material (§ 5.1.), i risultati che si ottengono per le due porzioni del profi lo sono profondamente diversi (tab. 3). ciononostante, è sembrato significativo procedere con la indicizzazione, quanto meno per un confronto quantitativo tra le due unità. in realtà, il problema appare ancora più complesso in quanto, sia per il gruppo di orizzonti bw1 e bw2, sia per l’orizzonte 2bt1 si ricava una generalizzata presenza di arricchimenti (valori residui che superano il 100%). di solito, tali arricchimenti sono legati all’esplicarsi dei fenomeni pedogenetici, che provocano una concentrazione degli elementi più stabili, a causa della perdita per alterazione di quelli meno stabili (e.g. busacca e singer, 1989). nel caso specifico, però, la percentuale residua non sembra seguire solamente questo schema: sono infatti presenti anche arricchimenti di elementi di facile alterazione (e.g. sodio e magnesio) accanto a perdite di elementi più stabili (e.g. titanio). appare chiaro come il residuo insolubile non costituisca, da solo, il materiale originario su cui ha avuto luogo la pedogenesi, ma debba, necessariamen137 fig. 6 l’indice di arrossamento del profilo del monte casto reddening index of mount casto profile. ssiioo22 aall22oo33 ffee22oo22 mmnnoo ttiioo22 pp22oo55 mmggoo nnaa22oo ccaaoo kk22oo bb11 - cc 48.74 85,87 83.96 158.58 67.55 55.12 151.39 370.48 20.60 217.53 bb11 - mm 28.09 60.95 57.89 27.93 43.32 46.61 80.83 180.62 39.66 165.88 bb11 - ff 27.33 129.78 135.95 138.81 57.09 186.81 297.79 80.60 37.36 211.66 bb22 - cc 41.84 101.22 97.04 184.30 64.41 31.38 163.71 538.90 20.70 245.59 bb22 - mm 28.91 80.87 81.23 5.45 48.41 36.84 118.12 163.60 30.84 187.67 bb22 - ff 27.62 121.71 127.49 130.17 53.54 175.19 279.27 75.58 42.78 198.50 22bbtt11 - cc 37.16 152.75 189.58 112.96 72.50 122.55 364.26 215.93 36.10 245.13 22bbtt11 - mm 37.95 131.26 153.55 166.94 69.96 76.69 327.70 201.44 104.46 237.67 22bbtt11 - ff 36.56 172.62 178.67 217.31 78.18 157.20 537.20 427.01 90.58 346.88 rreessiidduuoo 100 100 100 100 100 100 100 100 100 100 tab. 3 la percentuale residua degli elementi originari del profi lo del monte casto, riferita alla composizione chimica del residuo insolubile della dissoluzione del calcare del substrato. percentage of element remaining of mount casto profile, using the insoluble residue of limestone dissolution as parent material 4 eh x ipm %er = –––––––– x 100 epm x ih • %er percentuale residua dell'elemento considerato nell'orizzonte (rispetto ad un contenuto originale del parent material pari al 100%); • eh concentrazione dell'elemento considerato nell'orizzonte; • epm concentrazione dell'elemento considerato nel parent material; • ih concentrazione dell'elemento indice (titanio o zirconio) nell'orizzonte; • ipm concentrazione dell'elemento indice (titanio o zirconio) nel parent material. paleosuoli tipo terra rossa ... te, essere stato addizionato da contributi di materiale alloctono. tali contributi risultano massimi, se non esclusivi, per quanto riguarda l’unità superficiale, mentre più limitati, anche se evidenti, per l’orizzonte 2bt1. venendo ad osservazioni più strettamente pedogenetiche, è possibile notare come per l’orizzonte 2bt1 incrementi evidenti siano relativi a ferro, alluminio e manganese, cioè elementi legati ai fenomeni di rubefazione, di formazione di noduli e neoformazione e/o translocazione di argille. viceversa gli incrementi che tale orizzonte manifesta per magnesio, sodio, fosforo e parzialmente per il potassio (elemento stabile), sarebbero da imputarsi, in massima parte, al contributo di materiale di provenienza esterna. anche l’incremento di alluminio nell’unità profonda potrebbe essere imputabile almeno in parte ad una contaminazione eolica a lungo raggio (molinaroli et al., 1993) e non solo al manifestarsi dei fenomeni pedogenetici, precedentemente citati. 66.. ddiissccuussssiioonnee il profilo identificato e descritto sulle pendici del monte casto è costituito da due unità pedologiche distinte che vanno a formare un profilo composito: l’unità profonda è costituita dagli orizzonti 2bt1 e 2bt2, quella superficiale, dagli orizzonti o, bw1 e bw2. le due unità sono distinguibili in base alle loro caratteristiche morfologiche, chimiche e fisiche, ed anche attraverso i parametri utilizzati per evidenziarne il diverso grado di sviluppo morfologico e di espressione della pedogenesi. per quanto riguarda l’unità profonda, essa è costituita da un suolo fersiallitico (duchaufour, 1983), una terra rossa, che mostra le sue tipiche caratteristiche micromorfologiche, chimiche (rubefazione), granulometriche (tenore in argilla). in particolare, per quanto riguarda la micromorfologia, la relativa scarsità di figure pedologiche tessiturali sulla superficie dei vuoti non è in contraddizione con lo sviluppo di suolo fersiallitico, quanto piuttosto con l’incorporazione di tali figure nella massa di fondo a seguito di processi di shrink – swell, che inducono una b-fabric striata, come sintetizzato da fedoroff (1997). inoltre, per quanto riguarda i rapporti tra la sequenza profonda ed il substrato, non vi sono state identificate evidenze di fenomeni di trasporto lungo versante a carico di tali orizzonti: è dunque possibile ipotizzare che il substrato calcareo costituisca (almeno in parte) il parent material di tale porzione di suolo. d’altro canto, occorre anche considerare la terra rossa come un suolo di origine poligenetica, in cui si sommano gli effetti di diversi processi pedogenetici con una intensità relativa che può essere estremamente variabile da caso a caso (cremaschi, 1987; fedoroff, 1997; trombino, 1998): in questo caso risultano evidenti apporti di materiale esterno, probabilmente di natura eolica ad ampio raggio, come confermato dallo squilibrio chimico esistente tra la composizione del residuo insolubile della dissoluzione del calcare, ed il suolo stesso. infine, la sequenza profonda manca degli orizzonti superficiali, ha quindi subito una troncatura, causata da fenomeni di tipo erosionale. un primo elemento di caratterizzazione dell’unità superficiale è dato dal parent material dal quale essa si è formata: le caratteristiche sedimentologiche degli orizzonti bw1 e bw2 sembrano indicare la deposizione di una o più coltri di loess successivamente pedogenizzate. accanto a questa sorgente di tipo eolico occorre considerare la presenza di materiale messo in posto da fenomeni di versante, in particolare per l’orizzonte bw2, nel quale sono stati identificati pedorelitti arrotondati e papulae. tali figure, infatti, sono legate a fenomeni di colluviazione (mücher et al., 1972; bresson, 1974; cremaschi, 1991). dal punto di vista dell’alterazione pedogenetica, essa risulta essere stata sensibile anche per l’unità superficiale, anche se di intensità molto minore rispetto a quella della terra rossa. la superficie che separa le due unità è di facile identificazione, ma gli orizzonti di cui essa costituisce il limite mostrano una zona di transizione, che permette di ipotizzare un certo riarrangiamento. tale riarrangiamento risulta significativo in quanto sembra indicare che la separazione “fisica” delle due unità non vada semplicemente intesa come un evento unico, di breve durata. due sono infatti gli aspetti rilevanti di questa condizione: in primo luogo è possibile invocare un’alternanza di fasi di aggradazione e degradazione del profilo che, in corrispondenza della discontinuità, hanno aumentato il grado di riorganizzazione del materiale. in secondo luogo, la deposizione di una coltre di materiale loessico è un evento che interessa archi di tempo relativamente lunghi, con frequenti apporti di modeste quantità di materiale: un tipo di deposizione che implica un rallentamento piuttosto che una netta interruzione dei fenomeni pedogenetici (cremaschi, 1987; cremaschi e busacca, 1994; busacca e cremaschi, 1998). 77.. ccoonncclluussiioonnii la pedogenesi del profilo descritto sul monte casto presenta caratteristiche polifasiche. partendo dal basso, nel profilo è registrata una prima fase pedogenetica piuttosto spinta, che ha portato alla formazione di un suolo di tipo terra rossa, evidenza di una pedogenesi fersiallitica in clima mediterraneo (duchaufour, 1983). questo primo momento è stato seguito da una interruzione della pedogenesi, connessa ad una fase climatica che ha portato alla troncatura e all’erosione del profilo, quindi alla deposizione di materiale “fresco”. tale materiale risulta di origine prevalentemente eolica (loess), con un moderato apporto dovuto a fenomeni di colluviazione lungo il versante. molto probabilmente le fasi di degradazione del profilo sono state più di una, e l’apporto di materiale ha interessato un intervallo di tempo significativo, coincidente, almeno in parte, con la ripresa della pedogenesi. le fasi pedogenetiche più recenti, che hanno interessato la coltre di sedimenti eolici, sono state sicuramente meno intense della fase antica, ma comunque caratterizzate da processi di decarbonatazione, di scarsa translocazione di argilla e di moderata rubefazione. infine, appare necessario puntualizzare alcune osservazioni paleoclimatiche e cronologiche. la genesi geomorfologica della paleosuperficie su cui si sviluppa la terra rossa al tardo terziario (chardon, 1975), permette di collocare il termine post quem per l’origine e lo sviluppo di questo paleosuolo nel quatenario. d’altra parte, lo sviluppo di suoli con caratteristiche simili a quelle degli orizzonti profondi del profilo descritto necessita di specifiche condizioni climatiche e ambientali che possono essere connesse a periodi caldi come quelli occorsi prima del pleistocene glaciale (dunque pleistocene inferiore cremaschi, 1987; cremaschi e ginesu, 1990) o durante gli interglaciali del pleistocene medio (magaldi et al., 1985; magaldi e bidini, 1991). mancando elementi certi per datare la fase pedogenetica antica e le fasi pedogenetiche successive e, alla luce della natura poligenetica della terra rossa, l’attribuzione cronologica del paleosuolo ad uno dei periodi sopracitati risulta alquanto difficoltosa. il confronto dei livelli di alterazione raggiunti da paleosuoli simili, citati in letteratura, non risulta definitivo a causa della non corrispondenza geografica dei diversi profili: probabilmente solo uno studio pedostratigrafico dell’area potrebbe contribuire alla risoluzione di tale problema cronologico, seppure in modo relativo. ciononostante, il caso di studio del monte casto 138 l. trombino & f. ferraro risulta così un ulteriore esempio di come il suolo resti un imprescindibile strumento nella ricostruzione del nostro passato più recente, proprio in virtù della sua sensibilità alle variazioni che interessano litosfera, biosfera e atmosfera, di cui esso costituisce l’interfaccia. parte integrante di uno studio paleopedologico sono, in questo senso, tutti gli approcci in grado di mettere in luce, con la maggiore sensibilità possibile, le tracce di queste variazioni, registrate sotto varia forma all’interno del profilo del suolo. aappppeennddiiccee ddeessccrriizziioonnee ddeellllee sseezziioonnii ssoottttiillii le descrizioni sono state effettuate secondo i canoni proposti nel handbook for soil thin section description (bullock et al., 1985). talora, nel corso della discussione è stata parzialmente utilizzata la terminologia del sistema descrittivo proposto da brewer (1964). le classi di frequenza nella descrizione sono state attribuite secondo le “general purpose classes” (bullock et al. 1985) come segue: più che dominante > 70 %; dominante 50-70 %; comune 30-50 %; frequente 15-30 %; scarso 5-15 %; raro < 5 %. bbww11 microstruttura e porosità: microstruttura subangular blocky; comuni planes ad andamento ortogonale e lume dalla dimensione massima della sabbia fine media, scarsi canali a lume dalla dimensione massima della sabbia grossolana, scarsi vuoti di costruzione in corrispondenza di un livello organico. massa di fondo: materiale grossolano costituito da comuni grani di quarzo, subarrotondati, lisci, equidimensionali tabulari, di dimensioni fino alla sabbia grossolana, frequenti lamine di mica, subangolari, ondulate, tabulari, di dimensioni fino alla sabbia fine; materiale fine costituito da una massa di argilla, limo e ossidi di ferro, bruno giallastra, nebulosa a mosaico, con b-fabric cristallitica; limite c/f 10 µm, rapporto c/f 45/55, distribuzione relativa c/f porfirica. costituenti organici: resti vegetali parzialmente decomposti, concentrati nella parte superiore della sezione sottile. figure pedologiche: amorfe scarsi noduli di fe-mn, tipici, di dimensioni fino alla sabbia grossolana, scarse impregnazioni di fe-mn. bbww22 microstruttura e porosità: microstruttura subangular blocky; comuni planes a lume dalla dimensione massima della sabbia fine media, rari canali a lume dalla dimensione massima della sabbia media; presenza di aggregati arrotondati a matrice argillosa rossastra. massa di fondo: materiale grossolano costituito da comuni grani di quarzo, subarrotondati, lisci, equidimensionali tabulari, di dimensioni fino alla sabbia grossolana, frequenti lamine di mica, subangolari, ondulate, tabulari, di dimensioni fino alla sabbia fine, rari frammenti di selce subarrotondati, ruvidi, tabulari, con tracce di alterazione superficiale di dimensioni fino alla ghiaia; materiale fine costituito da una massa di argilla, limo e ossidi di ferro, rosso giallastra, opaca nebulosa, con b-fabric cristallitica a mosaico; limite c/f 10 µm, rapporto c/f 45/55, distribuzione relativa c/f porfirica a spazio da singolo a doppio. figure pedologiche: tessiturali, rari frammenti arrotondati di rivestimenti di argilla rosso giallastri; amorfe scarsi noduli di fe-mn, tipici, di dimensioni fino alla sabbia grossolana, scarse impregnazioni di fe-mn. 22bbtt11 microstruttura e porosità: microstruttura subangular blocky, crack all’interno dei poliedri; comuni planes a lume dalla dimensione massima della sabbia fine media, rari canali e camere a lume dalla dimensione massima della sabbia. massa di fondo: materiale grossolano costituito da scarsi grani di quarzo, subarrotondati, lisci, equidimensionali tabulari, di dimensioni fino alla sabbia fine, rare lamine di mica, subangolari, ondulate, tabulari di dimensioni fino alla sabbia fine, rari frammenti di selce di dimensioni fino alla ghiaia; materiale fine costituito da una massa di argilla ossidi di ferro, rossa, opaca a b-fabric maculata reticolare striata; limite c/f 2 µm, rapporto c/f 25/75, distribuzione relativa c/f porfirica a spazio aperto. figure pedologiche: tessiturali, rari rivestimenti di argilla, rosso giallastri, non continui, tipici, sottili, sulla superficie dei vuoti, rari frammenti arrotondati di rivestimenti di argilla rossi; amorfe scarsi noduli di fe-mn, tipici, di dimensioni fino alla sabbia grossolana. 22bbtt22 microstruttura e porosità: microstruttura subangular blocky, crack all’interno dei poliedri; comuni planes a lume dalla dimensione massima della sabbia fine media, rari canali e camere a lume dalla dimensione massima della sabbia grossolana. massa di fondo: materiale grossolano costituito da scarsi grani di quarzo, subarrotondati, lisci, equidimensionali tabulari, di dimensioni fino alla sabbia fine, rare lamine di mica, subangolari, ondulate, tabulari di dimensioni fino alla sabbia fine, rari frammenti di selce di dimensioni fino alla ghiaia; materiale fine costituito da una massa di argilla ossidi di ferro, rossa, opaca a b-fabric maculata reticolare striata; limite c/f 2 µm, rapporto c/f 20/80, distribuzione relativa c/f porfirica a spazio aperto. figure pedologiche: tessiturali, rari rivestimenti di argilla, rosso giallastri, non continui, tipici, sottili, sulla superficie dei vuoti; amorfe scarsi noduli di fe-mn, tipici, di dimensioni fino alla sabbia grossolana. rriinnggrraazziiaammeennttii il nostro primo ringraziamento va a mauro cremaschi: senza il suo aiuto, il suo incitamento e soprattutto senza il suo insegnamento questo lavoro non sarebbe esistito. quindi vorremmo esprimere la nostra gratitudine a lucas vanmechelen che ha stimolato il nostro interesse verso i problemi di contaminazione eolica delle terre rosse italiane. un sentito ringraziamento va ai referees stefano carnicelli e pierluigi pieruccini, che, con le loro osservazioni, ci hanno invitato ad ampliare le nostre vedute sul problema in esame, permettendoci di migliorare la qualità dell’articolo. infine un ringraziamento speciale va a pietro mario rossi, direttore del centro di studio per la geodinamica alpina e quaternaria di milano, per l’incoraggiamento ed il supporto fornitici. bbiibblliiooggrraaffiiaa arduino e., barberis e., carraro f. e forno m.g. (1984). estimating relative ages from iron-oxide / totaliron ratios of soils in the western po valley, italy. geoderma, 3333:: 39-52. 139paleosuoli tipo terra rossa ... avery b.w. e bascomb c. l. [ed.] (1974). soil survey laboratory methods. soil survey technical monograph, 66, harpenden. bresson l.m. (1974). a study of integrated microscopy: rubefaction under wet temperate climate in comparison with mediterranean rubefaction. in: rutherford g.k. [ed.], soil microscopy, pp. 526541. the limestone press, kingston. brewer r. (1964). fabric and mineral analysis of soils. john wiley and sons, new york. bullock p., fedoroff n., jongerius a., stoops g., tursina t. e babel c. (1985). handbook for soil thin section description. waine research publication, albrighton. busacca a.j. (1982). geologic history and soil development, northeastern sacramento valley, california. ph.d. dissertation, university of california, davis. busacca a. e cremaschi m. (1998). the role of time versus climate in the formation of deep soils of the appennine fringe of the po valley, italy. quaternary international, 5511//5522: 95-107. busacca a.j. e singer m.j. [eds.] (1989). pedogenesis of a chronosequence in the sacramento valley, california, usa, ii. elemental chemistry of silt fractions. geoderma, 4444: 43-75. busacca a.j., singer m.j. e verosub k.l. (1988). late cenozoic stratigraphy of the feather and yuba rivers area, california, with a section on soil development in mixed alluvium at honcut creek. u.s. geological survey bulletin, 1590-g. chardon m. (1975). les préalpes lombardes et leurs bordures. librairie champion, paris. cremaschi m. (1978). unità litostratigrafiche e pedostratigrafiche nei terreni quaternari pedeappenninici; loess e paleosuoli tra il fiume taro e il torrente sillaro. geografia fisica e dinamica del quaternario, 1: 4-22. cremaschi m. (1987). paleosols and vetusols in the central po plain (northern italy): a study in quaternary geology and soil development. unicoply, milano. cremaschi m. (1991). paleosuoli. in: cremaschi m. e rodolfi g. [ed.], il suolo, pp. 283-317. nuova italia scientifica, roma. cremaschi m. (1992). la penisola ital iana nel quaternario: aspetti geologici e geoarcheologici. in: guidi a. e piperno m [ed.], preistoria d’italia, pp. 15-39. laterza, bari. cremaschi m. e busacca a. (1994). deep soils on stable or slowly aggrading surfaces: time versus climate as soil-forming factors. geografia fisica e dinamica quaternaria, 1177: 19-28. cremaschi m. e ginesu s. (1990). morfogenesi e pedogenesi tardo terziaria e pleistocenica antica nella nurra occidentale (sardegna). nota preliminare. geografia fisica e dinamica quaternaria, 1133: 81-82. curioni g. (1877). geologia applicata delle province lombarde. milano. duchaufour ph. (1983). pédologie 1: pédogenèse et classification. masson, paris. fedoroff n. (1997). clay i l luviation in red mediterranean soils. catena, 2288: 171-189. frolking t.a., jackson m.l. e knox j.c. (1983). origin of red clay over dolomite in the loess-covered wisconsin driftless uplands. soil science society american journal, 4477: 817-820. gale s.j. e hoare p.g. (1991). quaternary sediments. belhaven press, london. hodgson j.m. [ed.] 1976. soil survey field handbook. describing and sampling soil profiles. soil survey technical monograph, 5, harpenden. macleod d.a. (1980). the origin of the red mediterranean soils in epirus, greece. journal of soil science, 3311: 125-136. magaldi d., angeli a., bidini d., brandini p.g. e magazzini p. (1985). i suoli dell'alveo del lago di bientina e delle colline a sud-ovest di massarella nella bassa valle dell'arno: genesi, cartografia, problemi d'uso. annali istituto sperimentale studio e difesa del suolo, 1166: 29-104. magaldi d. e bidini d. (1991). microscopic and submicroscopic characterization of a well developed plinthite in a buried middle pleistocene soil in northern tuscany (italy). quaderni di scienza del suolo, iiiiii: 31-44. molinaroli e., guerzoni s. e rampazzo g. (1993). contribution of saharan dust to the central mediterranean basin. in: johnsson m.j. e basu a. [ed.], processes controlling the composition of clastic sediments, geological society of america, special paper 228844: 303-312. mücher h.j., carballas j., guitian ojea f., jomgerius p.d., kroonenberg s.b. e villar m.c. (1972). micromorphological analysis of effects of alternating phases landscape stability on two profiles in galicia, north west spain. geoderma, 88: 241-266. munsell ® (1994). soil color charts. 1994 revised edition. munsell ® color, new windsor. olson c.g., ruhe r.v. e mausbach m.j. (1980). the terra rossa limestone contact phenomena in karst, southern indiana. soil science society american journal, 4444: 1075-1079. rhodes e.r. e sutton p.n. (1978). active iron ratio of some soils from three physiographic units in sierra leone. soil science, 112255: 326-328 soil survey staff (1990). keys to soil taxonomy. smss technical monograph 19, virginia polytechnic institute and state university. torrent j., schwertmann u. e schulze d.j. (1980). iron oxide mineralogy of some soils of two river terrace sequences in spain. geoderma, 2233: 191-208. trombino l. (1998). il suolo come memoria storica dei mutamenti paleoambientali. genesi e significato paleoclimatico delle “terre rosse” plio pleistoceniche. tesi di dottorato di ricerca in scienze naturalistiche e ambientali. milano. vanmechelen l., van ranst e., baert g. e aru a. (1993). eolian influence in terra rossa soils overlying dolomite in southwest sardinia, italy. quaderni di scienza del suolo, vv: 59-73. venzo s. (1965). rilevamento geologico dell’anfiteatro morenico frontale del garda, dal chiese all’adige. memorie della società italiana di scienze naturali e del museo civico di storia naturale di milano, xiv, i. vidic n. (1994). pedogenesis and soil age relationships of soils on glacial outwash terraces in the ljubljana basin. ph.d. thesis. university of colorado. yaalon d.h. (1997). soils in the mediterranean region: what makes them different. catena, 2288: 157-169. zippe f.x.m. (1853). über die grotten und höhlen von adelsberg, lueg, planina und laas. wien. 140 ms. ricevuto marzo 2002 ms. received: march 2002 l. trombino & f. ferraro sess 0_retro e indice edi.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 the open air pontinian: technological variability, geomorphology and settlement dynamics daniele aureli1, biagio giaccio2 & mario federico rolfo3 1 università degli studi di siena, dip. di scienze ambientali "g. sarfatti", u.r. ecologia preistorica, siena 2 igagcnr, monterotondo, roma 3 dipartimento di beni culturali facoltà di lettere università degli studi “tor vergata”, roma corresponding author: d. aureli <danieleaureli@gmail.com> abstract: aureli d., giaccio b. & rolfo m.f., the open air pontinian: technological variability, geomorphology and settlement dynamics. (it issn 0394-3356, 2011) this article presents the preliminary results of research carried out in recent years on the neanderthal settlement in the alban hills area. the investigations have been set on two distinct goals; i.e. (i) improving knowledge on pontinian occupations in the alban hills area through the identification and study of new open air sites, and (ii) integrate archaeological data with geological observations in particular for the volcanic complex of alban hills volcanic district. riassunto: aureli d., giaccio b. & rolfo m.f., il pontiniano di plein air: variabilità tecnica, geomorfologia e territorio. (it issn 0394-3356, 2011) cet article présente les résultats préliminaires des recherches menées ces dernières années sur le peuplement de néandertal dans la région de colli albani. les recherches se sont focalisées sur deux objectifs distincts. d'une part, améliorer les connaissances sur le peuplement pontinienne dans les marges septentrionales de l'aire pontinienne (région des colli albani) à travers l'identification et l'étude de nouveaux sites de plein air. deuxièmement, intégrer les données archéologiques aux observations géologiques en particulier avec le complexe volcanique de colli albani. key words: pontinian, open air site, geomorphology and volcanology, technological variability parole chiave: pontiniano, siti all’aperto, geomorfologia e vulcanologia, variabilità tecnica the strategy and the population dynamics of neanderthal populations still remains one of the most debated issue among the international scientific community. what were the ecological and social factors that led or conditioned these men to occupy and exploit specific territories? how can we interpret the behaviour and logical cognitive structures of neanderthals from archaeological data? the archaeological-geological context of the southern coast of latium, as well as its history of research and the peculiar characteristics of archaeological data, make this region an ideal framework to address these questions. the main aim of this paper is to reopen the debate on the scientific definition of the pontinian phenomenon by understanding the problem in its archaeological and geographical complexity. the theoretical condition is fundamental to consider all sites that define the problem of archaeological pontinian as a set system where each site is strictly interdependent with others in an integrated network of relationships that bind them to the deep territory. from there, it is necessary to reassess industries from the full range of sites in the region of plain and hilly area which is considered an important source of information and too little has been previously considered. the study of these series could then give a more accurate picture of the neanderthal occupation in this region. relatively recent research (bietti et al., 1991, grimaldi, 1988-89, kuhn 1990, mussi et al., 1984-87) show some variability in the technical pontinian phenomenon, observable both in time and space. the area defined as pontinian, was described from a geographical point of view as a rectangle of about 100 km long by 30 wide, bounded on the north by the tiber river, to the east by the alban hills and lepine mounts, to the south by the circeo and fondi plain, and west by the tyrrhenian sea. from a temporal view point, this techno-complex has been dated between about 100 and 40 ka, from age determinations mainly obtained in stratified caves sites (kuhn, 1990) and in two open air sites (blanc, 1937; rolfo et al., 2005). the archaeological material that reflects the technical variability of pontinian comes from two categories of sites. on a hand, there are cave sites (circeo and the province of fondi), and other open -air sites (plain and hill region), often found in nearsurface context. they yielded a significant number of stone tools, many of which may be associated with a specific geological setting "plus d’une cen 175 176 176 ms. received: testo ricevuto il taine de sites de surfaces ont été signalés, au cours de prospections systématiques, dans les environs de rome, au nord du tibre, et dans la pianura pontina (caloi l. et al., 1989). on 1999 a research program at the university of "tor vergata" in rome in collaboration with the national research centre was born. it attempts, through field work, to improve knowledge of the palaeolithic settlement of northern margins of the pontinian area (colli albani region) through the discovery of new sites, framed in morphological, tephrostratigraphic and tephrochronologic contexts (rolfo et al., 2007). the results of this research provided a first attempt to contextualise the surface archaeological collections with local morphological and pedo-stratigraphic context, providing a broad geo-archaeological framework for further work on the cultural pontinian phenomenon. the analysis of the areal dispersion of the archaeological material combined with geological observations point out that the lithic industry derive from the uppermost part of a well defined pedostratigraphic horizon. this is a deep paleosol developed on the pyroclastic deposits belonging to the so called faete phase of the alban hills volcanic district (308250 ka), which, in an wide north -eastern area of the alban hills, is overlaid by previously unrecognised distal deposits of the most recent alban hills volcanic activity of the albano maar (c. 70-36 ka) (giaccio et al., 2007). these new tephrostratigraphic and tephrochronologic data, in addition to confirm the independent, archaeological-based attribution of the lithic industries to the middle latium palaeolothic, provide a new, unheard useful dating and correlating tool worth careful consideration for the present and future research on the palaeolithic of the alban hills area (giaccio et al. 2007). in this paper we present the preliminary study of a series of open air sites found in stores. we focused our attention primarily on geomorphological aspects then on the lithic industries. the latter were analysed through a technological and technofunctional approach with the intend to understand the dynamics of land use, the functionality and functionally from the stone tools and the technical systems of flakes production of the pontinian phenomenon. references bietti a. & manzi g. (1991) the fossil man of monte circeo. sabaudia (latina, italy). quaternaria nova, 1, 19-21 october 1989. blanc a. c. (1937) nuovi giacimenti paleolitici del lazio e della toscana. studi etruschi xi, 273-304, firenze. caloi l. et al (1989) le moustérien du latium (italie centrale): archéologie, milieu naturel, chronologie. l'anthropologie, tome 92, n° 4, 73-98. giaccio b., sposato a., gaeta m., hajdas i., karner d.b., marra f., palladino d.m., taddeucci j. & renne p.r. (2005) the late pleistocene explosive activity of the albano maar, alban hills volcanic district, central italy new data for a reappraisal of the eruptive dynamics and history, abstracts for cities on volcanoes 4, quito, ecuador. giaccio b., sposato a., gaeta m., marra f., palladino d.m., taddeucci j., barbieri m., messina p. & rolfo m.f. (2007) mid-distal occurrences of the albano maar pyroclastic deposits and their relevance for reassessing the dynamic of the most recent eruptions at the alban hills volcanic district, central italy, quaternary international 171-172, 160-178. grimaldi s. (1988-89) approccio tecnologico all’industria pontiniana di grotta breuil – monte circeo, latina – tramite la sperimentazione. tesi di laurea università di roma la sapienza. kuhn s. l. (1990) diversity within uniformity: tool manufacture and use in the 'pontinian' mousterian of latium (italy). ph.d. dissertation, university of new mexico. mussi m. & zampetti d. (1984-87) la presenze umana nella pianura pontina durante il paleolitico medio e superiore. origini xiii, 7-26. rolfo m.f., giaccio b. & sposato a. (2007) siti del paleolitico medio nell'area dei colli albani e loro contesto morfologico e pedo-tefrostratigrafico. atti della xl riunione scientifica dell'istituto italiano di preistoria e protostoria “strategie di insediamento fra lazio e campania in età preistorica e protostorica, roma, napoli, pompei 30 novembre – 3 dicembre 2005, 275285. d. aureli, b. giaccio & m.f. rolfo january 13, 2011 13 gennaio 2011 imp.fioraso& manifestazioni carsiche nelle evaporiti messiniane del monferrato e della collina di torino (italia nord-occidentale): analisi dei meccanismi genetici nel quadro dell'evoluzione pliocenico-quaternaria del bacino terziario piemontese gianfranco fioraso1, erica bicchi2, andrea irace3 & paola boano2 1cnr istituto di geoscienze e georisorse, via accademia delle scienze 5, 10123 torino. e-mail: g.fioraso@csg.to.cnr.it 2collaboratore esterno del cnr istituto di geoscienze e georisorse, via accademia delle scienze 5, 10123 torino 3dipartimento di scienze della terra università di torino, via accademia delle scienze 5, 10123 torino riassunto: fioraso g. et al., manifestazioni carsiche nelle evaporiti messiniane del monferrato e della collina di torino (italia nordoccidentale): analisi dei meccanismi genetici nel quadro dell'evoluzione pliocenico-quaternaria del bacino terziario piemontese. it issn 0394-3356, 2004. la successione messiniana affiorante nel bacino terziario piemontese (btp) è interessata da diffusi fenomeni di dissoluzione che coinvolgono i blocchi gessosi, di dimensioni ettometriche-chilometriche, inglobati nella matrice marnoso-argillosa del complesso caotico della valle versa (ctv). la presenza nel monferrato settentrionale e nella collina di torino di numerose cave di gesso a cielo aperto e in sotterraneo, localizzate in contesti strutturali e a livelli stratigrafici differenti, ha fornito lo spunto per effettuare uno studio di dettaglio sulla distribuzione tridimensionale dei sistemi carsici, sulle caratteristiche morfologiche delle cavità e sul tipo di sedimenti di riempimento in essi presenti. le manifestazioni di dissoluzione epigee (camini a profilo cilindrico o conico a sviluppo verticale con diametro non superiore ai 5÷6 m) si localizzano nella prima decina di metri dei blocchi gessosi, al di sotto di una coltre di sedimenti impermeabili di spessore compreso tra i 4÷5 m e i 50 m. più in profondità la dissoluzione da luogo a condotti subverticali (con diametro inferiore a 3÷4 m) e cavità orizzontali a "soffitto piatto": queste ultime sono prodotte dal temporaneo stazionamento del livello di falda endocarsico e da concomitanti fenomeni di "stratificazione di densità" delle acque di percolazione che concentrano l'effetto dissolutivo nei settori marginali delle cavità. l'orientazione delle forme epigee e ipogee è inoltre sempre svincolata rispetto all'andamento locale della stratificazione degli intervalli gessosi del ctv. la dissoluzione è accompagnata da fenomeni di piping che consentono l'ingresso nei circuiti carsici dei prodotti della rielaborazione delle coltri di copertura e il loro trasferimento verso le parti più profonde e libere del reticolato ipogeo: l'infiltrazione dei sedimenti induce, in superficie, lo sviluppo di episodi di subsidenza (cover-subsidence sinkhole) e di sprofondamento (cover-collapse sinkhole) che coinvolgono per ampi tratti i versanti collinari modellati nel ctv. i tappi di sedimenti che occludono le cavità carsiche sono costituiti da: "brecce di collasso", prodotte dall'assestamento gravitativo delle coltri di copertura; "argille e silt massivi e laminati", riconducibili a episodi di decantazione in cavità sature; "sabbie massive e stratificate", veicolate da correnti trattive operanti all'interno dei circuiti carsici; "brecce di estrusione", generate da meccanismi di iniezione e spremitura dei sedimenti argillosi saturi d'acqua nelle parti più profonde e libere delle cavità ipogee. le analisi biostratigrafiche effettuate su 9 campioni di sedimenti prelevati all'interno di alcune cavità ipogee hanno evidenziato associazioni faunistiche rappresentative di un ampio intervallo temporale: burdigaliano (zona n5/6) zancleano (zona mpl4a) per la cava di montiglio, riferimento confermato dalla presenza di globorotalia puncticulata nel campione mnt-1 e di catapsydrax dissimilis, catapsydrax unicavus e globoquadrina dehischens in mnt-2; tortoniano (zona n17) zancleano (zona mpl2) per la cava di moncucco t.se, età confermata dalla presenza di globigerina quinqueloba in mc-13 e di globorotalia margaritae in mc-23; zancleano (zona mpl3) per grana m.to, età confermata dalla presenza di globorotalia margaritae e di globorotalia puncticulata in grn-1. i campioni mnc-1, mnc-2 e mnc-3 provenienti dalla cava di moncalvo sono risultati sterili. le associazioni individuate rispecchiano sempre l'assetto lito-strutturale locale della successione cenozoica presente al tetto delle bancate gessose carsificate. le caratteristiche dei sistemi carsici (assetto tridimensionale, dimensione e gerarchizzazione delle cavità, spessore del volume gessoso coinvolto) sono controllate dall'entità dell'esumazione, e quindi dal grado di dissezione da parte del reticolato idrografico, del ctv: quest'ultimo è caratterizzato nell'insieme da un assetto monoclinalico immergente di 2÷5° verso le aree depocentrali di asti e alessandria, che ha consentito di differenziare procedendo da nord verso sud: un "carso inciso" (entrenched karst), nel quale i blocchi selenitici sono profondamente dissecati dal reticolo idrografico (es. settori di murisengo e moncucco t.se). il gradiente idraulico è in questo caso maggiore rispetto agli adiacenti settori del complesso carsico monferrino e i fenomeni di dissoluzione coinvolgono l’intera potenza carsificabile dei gessi; un "carso subgiacente" (subjacent karst), nel quale l'intervallo gessoso è solo parzialmente inciso e drenato dal reticolato idrografico (es. settori di grana m.to e gessi di moncalvo) e la dissoluzione appare ben sviluppata unicamente al di sopra del livello di base locale; un "carso profondo" (deep-seated karst), nel quale i blocchi gessosi, posti al di sotto dei fondovalle, sono confinati e sigillati al di sotto dalla successione pliocenica monferrina (argille azzurre, sabbie di asti e villafranchiano auct.). le sporadiche manifestazione carsiche presenti sono in questo caso legate alla risalita di acque profonde lungo fasce di deformazione tettonica. la speleogenesi nei gessi è influenzata dalla presenza di potenti coltri di copertura, costituite dalla matrice del ctv e dalla sovrastante successione pliocenico-quaternaria, contraddistinte da bassi coefficienti di permeabilità che ostacolano il deflusso delle acque di percolazione. una volta raggiunta l'interfaccia con il gesso, il controllo sulla circolazione endocarsica è svolto dall'intreccio di 3 principali sistemi di faglie e fratture orientati in direzione e-w, ne-sw e n-s. queste discontinuità costituiscono le uniche vie di deflusso delle acque in un mezzo altrimenti caratterizzato da bassi valori di porosità primaria compresi tra il 4 e l'8% del volume roccioso. le faglie interrompono inoltre la continuità degli interstrati pelitico-bituminosi che imporrebbero altrimenti la compartimentazione dei circuiti idrocarsici all'interno delle bancate gessose. la variazione dei parametri morfometrici (diametro e lunghezza) dei condotti carsici e del loro grado di interconnessione idraulica conil quaternario italian journal of quaternary sciences 17(2/2), 2004, 453-476 454 g. fioraso et al. fermano che il picco dissolutivo si manifesta nei primi 15÷20 m dei corpi gessosi: l'aggressività dell'acqua, infatti, diminuisce in breve tempo e a breve distanza dal punto di ingresso nel sistema carsico, grazie all'elevata velocità di saturazione in caso4 · 2h2o della soluzione in rapporto alla velocità di deflusso. il limitato numero di condotti ipogei intercettati dai fronti di coltivazione spinti al di sotto dei fondovalle (es. cave di gessi di moncalvo, murisengo e montiglio) conferma inoltre l'arresto della dissoluzione in prossimità della superficie della falda freatica, che a sua volta si raccorda con il livello di base locale: le basse velocità di deflusso che contraddistinguono la zona satura rispetto a quella areata non consentono un rapido ricambio delle acque, inibendo l'azione dissolutiva che in tal modo non può svilupparsi nella sua completezza. l'analisi dei rapporti che intercorrono tra l'orientazione degli intervalli evaporitici e la vergenza delle forme dissolutive evidenzia chiaramente la sequenzialità del fenomeno carsico rispetto all'assetto stratigrafico assunto localmente dal ctv. inoltre la presenza di cavità a "soffitto piatto" altimetricamente correlabili con lembi di depositi fluviali terrazzati (con indice di colore massimo pari a 5÷7,5 yr) conservati a varie quote lungo le dorsali collinari del monferrato, avvalora l'ipotesi secondo cui queste morfologie endocarsiche materializzerebbero delle paleo-superfici freatiche originariamente in raccordo con antichi livelli di base. ciò consente di ipotizzare, quanto meno nei settori di maggior maturità dei sistemi carsici (es. murisengo e moncucco t.se), un’età delle forme dissolutive compresa tra la parte superiore del pleistocene medio e l'attuale. i sistemi carsici impostati nei gessi messiniani del monferrato e della collina di torino e i depositi in essi ospitati rappresentano il prodotto di concomitanti fenomeni di dissoluzione e sedimentazione polifasici e policronologici, sviluppati in risposta alle continue variazioni indotte sull'assetto morfologico superficiale dall'esumazione del ctv. quest'ultima è l'espressione della deformazione che ha determinato il sovrascorrimento verso nord della successione cenozoica del btp sull'avanfossa padana: al procedere dell'esumazione si contrappone la migrazione relativa del fronte di dissoluzione, che viene in tal modo a collocarsi in posizioni via via più prossime alla base dell'intervallo evaporitico. abstract: fioraso g. et al., karst phenomena in messinian succession of monferrato and torino hill (north-western italy): speleogenetic mechanism and interaction with pliocenic to quaternary evolution of tertiary piedmont basin. it issn 0394-3356, 2004. in tertiary piedmont basin (tpb) widespread karst phenomena involved messinian gypsum blocks (hectometric to kilometric in extention) cropping out within the clayey matrix of the valle versa chaotic complex (ctv). the presence of some gypsum quarries in northern monferrato area and in torino hill (whether opencast or underground) allowed the investigation of speleogenetic phenomena in different structural and stratigraphic contexts. this study has been carried out in order to detect three-dimensional array of karst systems, morphological characteristics of dissolution cavities and sedimentological analysis of karst infill deposits. moreover, it has been possible to reconstruct some of karst evolutionary stages related to the pliocenic to quaternary exumation of tpb. cilindrical or cone-shaped subvertical pipes less than 5÷6 m in diameter which characterize epigean dissolution morphology are located within upper 10 m of evaporitic rocks, below an impermeable sedimentary cover with thickness ranging between 4÷5 m and 50 m. in depth, dissolution make up subvertical pipes (less than 3÷4 m in diameter) connected with horizontal caves with typical "flat ceilings" and inclined (15÷45°) lateral facets. these forms are caused by a standing of water table combined with water chemical stratification phenomena: local small differences in water density promote natural convection currents inside gypsum caves which enable most pronunciated marginal dissolution by uppermost aggressive layers of water. orientation of epigean and hypogean morphology is geometrically unrelated in respect to the bedding of ctv gypsum layers. gypsum dissolution combine with suffosion processes so that transfer of insoluble sediments of the overlying clayey sequence inside empty karst cavities is enabled. this result in a gradual subsidence of the topographic surface or in a sudden collapse of the overburden, with development of cover-subsidence and cover-collapse sinkhole respectively, depending on granular composition and thickness of the coverbeds. such features are well developed all over the outcropping area of ctv. epikarst depressions and endokarst caves are filled with intricate sequences of deposits, made up of at least 4 sedimentary facies: a) "collapse breccia", developed by gravitational sinking of sedimentary coverbed; b) "massive or laminated silt and clay", due to sediments settling in water-filled karst features; c) "massive or laminated sands", transported by percolating water inside karst system; d) "extrusion breccia", generated by injection and squeezing of water-saturated clayey sediments along deepen free portions of caves. distribution of sedimentary facies within karst network is highly variable in both vertical and horizontal directions. biostratigraphical analysis carried out on 9 samples collected inside few hypogean cavities allows the detection of rich faunal assemblages covering a wide chronological interval: burdigalian (n5/6 zone) zanclean (mpl4a zone) for samples collected in montiglio quarry, in which are present globorotalia puncticulata in mnt-1 and catapsydrax dissimilis, catapsydrax unicavus and globoquadrina dehischens in mnt-2; tortonian (n17 zone) zanclean (mpl2 zone) for samples collected in moncucco t.se quarry, age confirmed by the presence of globigerina quinqueloba in mc-13 and of globorotalia margaritae in mc-23; zanclean (mpl3 zone) for samples grn-1 collected in grana m.to quarry, confirmed by the presence of globorotalia margaritae and globorotalia puncticulata. on the contrary, sediments collected on moncalvo quarry (samples mnc-1, mnc-2 and mnc-3) are completely devoid of microfaunal remains. differences in faunal assemblages from one site to another are due to the specific and local litho-structural arrangement of cenozoic succession resting above the gypsum interval. three-dimentional array of cave network, size and interconnection magnitude of hypogean conduits and thickness of gypsum volume involved in dissolution processes are controlled by exumation rate of ctv and consequently by superficial fluvial erosion. from northern monferrato to torino hill, the messinian succession has a monoclinalic configuration dipping of 2÷5° to the depocentral areas of asti and alessandria, so that it is possible to distinguish, from north to south, three types of intrastratal karst: "entrenched karst", with gypsum completely dissected by fluvial erosion (i.e. murisengo and moncucco t.se areas). hydraulic gradient is greater than in other sectors of karst complex and dissolution operate across the whole thickness of the evaporite formation; "subjacent karst", where gypsum is only partially dissected by superficial drainage system (i.e. grana m.to and gessi di moncalvo areas). dissolution phenomena are well developed inside gypsum rocks only above hydrological base-level; "deep-seated karst", where gypsum sequence is buried and hydrologically confined below a thick post-messinian sedimentary cover, represented by pliocenic argille azzurre and sabbie di asti formations and by pliocenic to quaternary villafranchian complex. due to the thickness of the overburden (> 40÷50 m), deep-seated karst is devoid of any surface expression. locally dissolution phenomena are linked to the rising of deep water along fault zones. development of gypsum dissolution is controlled by lithology and thickness of the coverbeds, generally characterized by low permeability (particularly the clayey matrix of ctv and the argille azzurre formation), that slow down the trasmission of seepage water across the overburden. just in contact with gypsum, water circulation depends on the pattern distribution of at least 3 fault and fracture systems with e-w, ne-sw and n-s directions. such discontiniuties assumed the major role in determining the initial flow path inside a gypsum, otherwise characterised by low percentage (4÷8%) of primary porosity. moreover, fault systems intersect and displace the impermeable bituminous inter-beds (with tickness < 3 m) controlling water circulation between adjacent gypsum intervals. tipology and dimensions (cross-section diameter and length) of karst features combined with analisys of cave pattern prove that the highest dissolution rate occur within the first 15÷20 m below gypsum-coverbed interface: saturation index of solution in respect to caso4 · 2h2o rapidly increase after the entrance inside karst system. moreover, the restricted number of pipes and horizontal caves intercepted by underground mining exploitation below the base-level (i.e. gessi di moncalvo, murisengo and montiglio quarries) con1. introduzione i sistemi carsici rappresentano eccellenti punti chiave per la ricostruzione della storia morfo-evolutiva di un rilievo: in essi, infatti, sono spesso chiaramente conservate le tracce, in forma di cavità di dissoluzione e di depositi di riempimento chemio-clastici, che ne attestano alcune delle infinite tappe evolutive (salomon, 1999; nicod, 2002). inoltre, la particolarità dei sistemi carsici risiede nel poter adeguare più o meno rapidamente la propria fisionomia alle variazioni morfologiche indotte sul territorio dalla mobilità tettonica e dai processi erosivo-deposizionali che avvengono in superficie. la distribuzione tridimensionale delle forme di dissoluzione e dei depositi in esse contenuti costituisce pertanto un ideale registro naturale della successione di eventi che scandiscono l'evoluzione di un rilievo: questo ruolo è favorito dall'elevata conservatività dell'ambiente carsico, legata da un lato alle particolari modalità di infiltrazione e di deflusso ipogeo delle acque di precipitazione, dall'altro all'assenza di un reticolato idrografico di superficie in grado di operare con sufficiente incisività lo smantellamento del rilievo. quanto sopra esposto ben si adatta non solo ai sistemi carsici modellati nei comuni substrati carbonatici, ma anche a quelli, meno diffusi, sviluppati nelle successioni evaporitiche. la carsogenesi nei gessi, tuttavia, pur dando luogo a manifestazioni in prima approssimazione confrontabili con quelle presenti nelle rocce carbonatiche (macaluso et al., 2001; johnson, 2002), è caratterizzata da un'elevata velocità della cinetica dissolutiva: ciò conferisce una minore inerzia del carso gessoso nella risposta offerta alla mobilità tettonica e una sensibile riduzione dei tempi di reazione del sistema carsico alle variazioni morfologiche del rilievo. la rapidità evolutiva costituisce pertanto il principale carattere distintivo dei processi di dissoluzione sviluppati nei gessi, dovuta all'estrema facilità con cui queste rocce possono essere disciolte: in acqua distillata a 20°c e alla pressione di 1 atm, il gesso risulta infatti 183 volte più solubile della calcite (jakucs, 1977), cosicché la dissoluzione può operare con una velocità di due ordini di grandezza più elevata rispetto a quanto mediamente avviene in rocce calcaree (eck & redfield, 1965). il territorio piemontese si caratterizza per la fre455manifestazioni carsiche nelle evaporiti ... quente presenza di gessi, distribuiti in due ben distinti contesti geologici: un primo gruppo di circoscritte masse gessose di età triassica sottolinea alcuni dei principali contatti tettonici e orizzonti di scollamento dell'arco alpino occidentale; un secondo e più cospicuo gruppo affiora nella successione messiniana del bacino terziario piemontese (btp) (fig. 1a), nell’ambito della quale da lungo tempo sono state riconosciute manifestazioni carsiche (sacco, 1889-1890; 1925; marinelli, 1917). i rilievi recentemente condotti per la realizzazione del foglio 157, "trino", alla scala 1:50.000 del progetto carg (dela pierre et al., 2003b) e quelli attualmente in corso di svolgimento nel contiguo foglio 156, "torino est", hanno consentito di delineare con maggior precisione la distribuzione, l’entità e la tipologia di questi fenomeni: da un lato è emersa la notevole frequenza degli episodi di dissoluzione sviluppati a spese degli intervalli gessosi, dall'altro è stata evidenziata la complessità dei sistemi carsici dovuta al concomitante sviluppo di manifestazioni para-carsiche (piping) che coinvolgono estesamente le sovrastanti coltri terrigene di copertura (fioraso & boano, 2002): queste ultime comprendono sia i termini della successione marina post-evaporitica, sia i depositi quaternari continentali (coltri eluvio-colluviali, depositi fluviali e accumuli di frana). in questo contesto sono state effettuate nuove e più dettagliate indagini, finalizzate a chiarire i rapporti intercorrenti tra lo sviluppo del carsismo nell'ambito della successione messiniana e l’evoluzione post-miocenica del btp. l'analisi è stata condotta attraverso la sistematica raccolta di informazioni di carattere morfologico, stratigrafico e micropaleontologico riguardanti le cavità e i relativi depositi di riempimento. il lavoro è stato agevolato dalla presenza, nelle aree del monferrato e della collina di torino, di numerosi fronti di coltivazione a cielo aperto e di cavità minerarie sotterranee che in più punti hanno intercettato il reticolato carsico epigeo e ipogeo. le cave, realizzate per lo sfruttamento dei banchi gessosi, sono distribuite in una fascia compresa tra gli abitati di grana m.to, a est, e moncucco t.se a ovest (fig. 1). tale opportunità ha consentito di definire i limiti e l'assetto tridimensionale dei circuiti carsici e di analizzare i meccanismi speleogenetici a livelli stratigrafici e in contesti strutturali alquanto differenti. in tal modo è stato possibile tracciare un dettagliato quadro firm that dissolution rates drastically reduce in proximity of the water table, the last one fitting with local base-level: flow velocities in phreatic conditions are lower in comparison with those of vadose zone, so that water is not allowed to have a rapid exchange and speleogenesis does not fully develop inside evapotitic rocks. spatial orientation of dissolution pipes diverging from gypsum bedding clearly demonstrate the sequentiality of dissolution phenomena in comparison to litho-structural array of ctv. locally "flat ceilings" in horizontal caves are altimetrically correlable with terraced fluvial deposits (with highest color index of 5÷7,5 yr) preserved along valley sides of monferrato and torino hill: such features materialize paleo-phreatic surfaces originally related to old fluvial base-levels. available data point out a late middle pleistocene to olocene age for the karst systems characterized by highest evolution, like in murisengo and moncucco t.se areas. gypsum karst and related deposits in tpb, representing the products of polyphasic and polychronologic dissolution phenomena, developed in responce to morphological change induced by differential exumation of ctv. uplifting of messinian succession is linked to the tectonic deformation due to the northern thrusting movements of the tpb succession over padanian foredeep: the ongoing exumation is accompained by progressive downward migration of a dissolution boundary (that gradually comes close to and finally intersects the base of evaporitic succession) and by an evolutionary sequence of karst types providing the transition from deep-seated to entrenched karst. parole chiave: carsismo, suffosione, gesso, messiniano, collina di torino, monferrato. keywords: : karst, piping, gypsum, messinian, torino hill, monferrato. 456 g. fioraso et al. fig. 1 a) inquadramento geologico dell'area di studio. 1: catena alpina (al); 2: catena appenninica (ap); 3: falde liguri (fl); 4: bacini sedimentari paleogenico-neogenici su substrato alpino (ct = collina di torino; lg = langhe) e appenninico (mn = monferrato); 4a: successione messiniana (m); 5: sedimenti pliocenico-quaternari; 6: fronti di sovrascorrimento; 7: cava di moncucco t.se. b) schema geologico del monferrato settentrionale (da dela pierre et al., 2003b, modificato). daq: depositi alluvionali quaternari; smd: sabbie di ferrere, silt di s. martino e unità di morialdo ("villafranchiano" auct.); ast: sabbie di asti; faa: argille azzurre; ctv: complesso caotico della valle versa ("formazione gessoso-solfifera" auct.); saf: marne di s. agata fossili; min: marne di mincengo; cto: areniti di tonengo; pdc: pietra da cantoni; ama: arenarie di moransengo; mpi: marne a pteropodi inferiori; ant: formazione di antognola; cad: formazione di cardona; mmp: marne di monte piano; cmo: formazione di casale monferrato; ccp: complesso caotico di la pietra; gs: principali affioramenti di gesso. a: faglie; b: faglie incerte o sepolte; c: traccia delle sezioni geologiche; d e: cave attive e inattive (1 = banengo; 2 = montiglio; 3 = corziagno; 4 = bricco; 5 = murisengo; 6 = pirenta; 7 = borghi; 8 = gessi di moncalvo; 9 = verginetto; 10 = c.ne pietra; 11 = grana m.to; 12 = madonnina); f: sorgenti cloruroe solfato-calciche (s1 = pirenta di murisengo; s2 = calliano); g: sorgenti bicarbonato-calciche e magnesiache (s3 = capriglio; s4 = lussello; s5 = alfiano natta; s6 = ponzano); h: sorgenti cloruro-sodiche (s7 = passerano-marmorito); i: principali lembi di depositi fluviali terrazzati. a) geological sketch of the tertiary piedmont basin. 1: alpine thrust belt (al); 2: apenninic thrust belt (ap); 3: ligurian nappes (fl); 4: alps-related (ct = torino hill; lg = langhe) and apennines-related (mn = monferrato) paleogenic to neogenic sedimentary domains; 4a: messinian succession (m); 5: pliocenic to quaternary sediments; 6: apenninic thrusts; 7: moncucco t.se quarry. b) geological sketch of the northern monferrato area (from dela pierre et al., 2003b, modified). daq: quaternary alluvial sediments; smd: ferrere sands, s. martino silts and morialdo unit ("villafranchiano" auct.); ast: asti sands; faa: argille azzurre; ctv: valle versa chaotic complex ("gessoso-solfifera formation" auct.); saf: s. agata fossili marls; min: mincengo marls; cto: tonengo arenites; pdc: pietra da cantoni; ama: moransengo sandstones; mpi: pteropodi marls; ant: antognola formation; cad: cardona formation; mmp: monte piano marls; cmo: casale monferrato formation; ccp: la pietra chaotic complex; gs: main gypsum bodies. a: faults; b: uncertain or buried faults; c: traces of geological cross-sections; d e: active and inactive quarry (1 = banengo; 2 = montiglio; 3 = corziagno; 4 = bricco; 5 = murisengo; 6 = pirenta; 7 = borghi; 8 = gessi di moncalvo; 9 = verginetto; 10 = c.ne pietra; 11 = grana m.to; 12 = madonnina); f: cl / so4 2/ ca2+ springs (s1 = pirenta di murisengo; s2 = calliano); g: hco3 / ca2+ / mg2+ springs (s3 = capriglio; s4 = lussello; s5 = alfiano natta; s6 = ponzano); h: cl / na+ springs (s7 = passerano-marmorito); i: fluvial terraces. 457 dei fenomeni dissolutivi e dei concomitanti episodi di sedimentazione, consentendo inoltre di delineare un modello evolutivo del fenomeno carsico in accordo con il contesto idrologico e idrogeologico locale. l'analisi integrata dei dati di superficie e di sottosuolo ha infine permesso di ricostruire alcune delle tappe che hanno scandito l'evoluzione del complesso carsico messiniano e accompagnato le ultime e più recenti fasi di strutturazione dei rilievi del monferrato settentrionale e della collina di torino. 2. assetto litostratigrafico e morfologico i depositi messiniani affioranti lungo il margine settentrionale del btp costituiscono una fascia pressoché continua, orientata all’incirca in direzione e-w, lungo i settori meridionali delle unità del monferrato a est e della collina di torino a ovest (rispettivamente mn e ct in fig. 1a). questi sedimenti, compresi nella formazione gessoso-solfifera (bonsignore et al., 1969), sono stati classicamente descritti come un intervallo stratigrafico costituito da marne argillose contenenti lenti e corpi eterometrici di gesso selenitico e di calcari vacuolari (“calcari a cellette”). studi di dettaglio effettuati da sturani (1973) nel settore sw del btp hanno consentito di individuare tre distinti intervalli stratigrafici: un intervallo inferiore “pre-evaporitico”, costituito da sedimenti marini profondi deposti in normali condizioni di salinità e corrispondenti al “tripoli” della sicilia; un intervallo intermedio “evaporitico”, rappresentato da depositi lagunari, introdotto da sottili livelli calcarei (“calcare di base”) e costituito da gesso microcristallino laminato (gesso balatino); un intervallo superiore “post-evaporitico”, costituito da sedimenti alluvionali, palustri e lacustri (“strati a congerie”), confrontabili con le facies "lago-mare" riconosciute in gran parte dell’area mediterranea (rouchy et al., 2001) e descritti e cartografati nel btp meridionale come conglomerati di cassano-spinola (boni & casnedi, 1970). la successione individuata da sturani rappresenta tuttavia un’eccezione all’interno del btp: infatti, al margine se del btp, la gessoso-solfifera è interamente costituita da masse di gesso disarticolate e da livelli, riconducibili a fenomeni di debris-flow, costituiti da cristalli di gesso immersi in una matrice pelitica con zolle di peliti varvate (ghibaudo et al., 1985). anche i rilievi recentemente effettuati nel monferrato settentrionale per la realizzazione del foglio 157 “trino” (dela pierre et al., 2003b) hanno confermato che i depositi messiniani sono in realtà costituiti da un intervallo caotico di sedimenti, informalmente denominato “complesso caotico della valle versa” (ctv) (dela pierre et al., 2003a). i depositi del ctv poggiano in discordanza su sedimenti marini di età compresa tra l’oligocene e il tortoniano (formazione di cardona, areniti di tonengo, marne di mincengo e marne di s. agata fossili) e sono seguiti, sempre in discordanza, dai depositi emipelagici pliocenici della formazione delle argille azzurre, costituita da membri siltoso-argillosi, argillosi e siltoso-sabbiosi (fig. 1b). il ctv è caratterizzato da notevoli variazioni di potenza (con valori massimi pari a 100÷150 m) ed è composto da blocchi di dimensioni chilometriche/decametriche inglobati in una matrice argillosa. i blocchi sono costituiti da calciruditi e calcareniti fossilifere, indicativi di una sedimentazione carbonatica in acque poco profonde, del messiniano inferiore pre-evaporitico, da alternanze di gessi selenitici, peliti e calcari vacuolari riferibili alla fase evaporitica, e da conglomerati poligenici post-evaporitici. sono inoltre presenti blocchi di calcari micritici fortemente cementati, con modelli interni di lucinidi, e brecce carbonatiche, interpretabili come calcari metano-derivati (clari et al., 1994). la matrice del ctv è rappresentata, almeno localmente, da mud-breccias nelle quali è stato riscontrato un notevole mixing delle associazioni a microfossili, testimoniato dalla compresenza di forme riferibili al miocene, all’oligocene e all’eocene (dela pierre et al., 2002). i blocchi di dimensioni maggiori (chilometriche/ ettometriche) sono costituiti da un’alternanza ciclica di banchi di gesso selenitico, potenti da qualche metro fino a un massimo di 30 m, e di livelli pelitici bituminosi di spessore compreso tra pochi decimetri fino a un massimo di 3 m (es. gessi di moncalvo). ogni coppia pelite-gesso costituisce un singolo ciclo evaporitico (vai & ricci lucchi, 1977) e testimonia il graduale passaggio a condizioni iperaline, favorevoli alla precipitazione della selenite che si presenta con la caratteristica geminazione a “coda di rondine”. l’evidente diminuzione di taglia dei cristalli (da decimetrica a millimetrica) verso il tetto dei banchi di gesso riflette la progressiva saturazione dell'originaria salamoia: ciò, tuttavia, non costituisce una regola, potendosi talvolta osservare una gradazione inversa dei cristalli. a vari livelli stratigrafici sono inoltre presenti intercalazioni di corpi gessoruditici e gessarenitici che testimoniano fenomeni erosionali, a pelo d’acqua o subaerei, a spese dei depositi solfatici primari. la potenza complessiva delle bancate gessose è di poco superiore ai 100÷120 m (bosticco et al., 1992; bosticco & marini, 1995). la giacitura della stratificazione è piuttosto irregolare, variando da suborizzontale (es. grana m.to; fig. 2, sez. a-a') o poco inclinata (10° verso se a moncalvo; fig. 2, sez. b-b'), fino a sensibilmente inclinata (50° verso sse) come a murisengo. i gessi del monferrato sono attraversati da tre sistemi di strutture disgiuntive: un sistema e-w, visibile in quasi tutti i fronti di cava, costituito da faglie e fratture, il più delle volte immergenti a sud, con inclinazione compresa tra 50° e 90° e direzione variabile da n70° a n105°; un sistema ne-sw, rappresentato da faglie immergenti sia a se che a nw con inclinazione compresa tra 60° e 90° e direzione variabile da n30° a n65°; un sistema n-s, riscontrabile unicamente nel settore compreso tra murisengo e montiglio, costituito da strutture ad andamento subverticale. anche nella collina di torino l'intervallo messiniano, sempre attribuito al ctv (polino, 2002; irace et al., 2002), è in gran parte caratterizzato da un assetto caotico, espresso dalla distribuzione casuale di blocchi carbonatici e gessosi all'interno di una matrice marnoso-argillosa poco coerente e male esposta. i blocchi carbonatici, da decimetrici a metrici, risultano del tutto confrontabili con quelli presenti nel monferrato. i blocchi di gesso, con l'esclusione della sola area di moncucco t.se, sono di dimensioni assai ridotte e il più delle volte rappresentati da clasti di taglia decimetrica dispersi nella matrice. manifestazioni carsiche nelle evaporiti ... 458 nella collina di torino la superficie basale del ctv corrisponde a una discordanza che comporta la diretta sovrapposizione del complesso sulle marne di mincengo e di s. agata fossili. tuttavia, a differenza di quanto osservato nel monferrato, tale superficie risulta modellata meno profondamente nei termini più antichi ed è ancora possibile osservare (anche se solo localmente) la porzione sommitale delle marne di s. agata fossili, riferibile al messiniano inferiore pre-evaporitico. nella cava di moncucco t.se è visibile la tri-partizione della successione messiniana proposta da sturani (1973), ma in un contesto tettonico che ha in gran parte obliterato gli originari rapporti stratigrafici (fig. 2, sez. d-d'): i depositi pre-evaporitici del messiniano inferiore (marne di s. agata fossili) sono infatti intensamente deformati e giustapposti all’unico corpo gessoso affiorante nella coll ina di torino tramite due sistemi di faglie transpressive: il primo, a direzione media n170÷180°, immerge di 30÷60° verso ene; il secondo, a direzione n20÷30°, è costituito da faglie coniugate con inclinazioni variabili da 50÷60° verso wnw a 20° verso sw, che descrivono in sezione una struttura "a fiore" asimmetrica verso se (festa et al., 2002; polino, 2002). la successione evaporitica si presenta inclinata di 45÷50° verso ssw ed è costituita da bancate di gesso selenitico potenti da 10 a 30 m alternate a livelli pelitici decimetrici (irace et al., 2002). i contatti tettonici sono progressivamente sigillati da marne argillose e da mud-breccias (inglobanti blocchi di gessi selenitici, di gessoruditi, di calcari vacuolari e brecciati), nonché da peliti beige passanti a marne siltose verdastre, contenenti associazioni fossilifere tipiche di acque salmastre (limnocardium sp., dreissena sp., melanopsis sp.), che consentono un riferimento al messiniano post-evaporitico (facies “lago-mare”). infine segue, in discordanza, la formazione delle argille azzurre, di età pliocenica inferiore. i dati il lustrati consentono quindi di delineare un quadro piuttosto articolato della successione messiniana: nel monferrato settentrionale il messiniano è rappresentato da un intervallo caotico di sedimenti (ctv) che ingloba depositi preevaporitici, evaporitici e post-evag. fioraso et al. fig. 2 sezioni geologiche e localizzazione dei punti di campionamento dei sedimenti carsici. per l'ubicazione delle sezioni cfr. fig. 1. ctv: complesso caotico della valle versa; saf: marne di s. agata fossili; daq: depositi alluvionali quaternari; faa/9: argille azzurre membro siltoso-argilloso; faa/10: argille azzurre membro argilloso; ast/2: sabbie di asti membro sabbioso; 1: gesso; 2: terreno di riporto; 3: cavità carsiche; 4: faglie; 5: sigla del campione; 6: livello di coltivazione. geological cross-sections and localization of samples collected inside karst cavities. traces of cross-sections are shown in fig. 1. ctv: valle versa chaotic complex; saf: s. agata fossili marls; daq: quaternary alluvial sediments; faa/9: argille azzurre silty-clayey member; faa/10: argille azzurre clayey member; ast/2: asti sands sandy member; 1: gypsum; 2: waste disposal; 3: karst cavities; 4: faults; 5: sample number; 6: mining drift. poritici; nella collina di torino l’intervallo post-evaporitico, costituito dai depositi di lago-mare, è invece solo in parte caotico e sembra sigillare un importante evento deformativo intra-messiniano. in entrambi i settori investigati l'assetto del ctv è l'effetto della combinazione degli eventi sedimentari connessi alla crisi di salinità messiniana (hsü et al., 1973) e dei fenomeni tettonici sviluppatisi a scala regionale (pieri & groppi, 1981; gelati et al., 1987; piana, 2000; roveri et al., 2001; 2003). il fatto che la successione messiniana del monferrato e della collina di torino sia in gran parte costituita da isolati lembi risedimentati di evaporiti primarie, attualmente in giacitura secondaria, implica infatti una disarticolazione dell'originaria successione che consente di riferire il fenomeno di "caoticizzazione" all’intervallo post-evaporitico. per la genesi del ctv è stato ipotizzato l'intervento di collassi gravitativi a scala regionale guidati dalla tettonica e la concomitante risalita diapirica di sedimenti fini non consolidati e permeati da fluidi (dela pierre et al., 2002; 2003a). dal punto di vista morfologico, l'area di affioramento del ctv è contraddistinta da rilievi collinari poco acclivi che si elevano a non più di 300÷350 m s.l.m. le dorsali spartiacque hanno un profilo trasversale convesso, regolare e simmetrico e si raccordano ai piatti e ampi fondovalle tramite spessori più o meno consistenti di prodotti colluviali. il fondo delle incisioni vallive è costituito da coltri di depositi fluviali siltoso-sabbiosi, con intercalazioni ghiaiose e sabbiose, di esiguo spessore ma che localmente possono raggiungere valori di 6÷8 m. il profilo longitudinale delle dorsali collinari è interrotto da rotture di pendenza che sottendono superfici subpianeggianti di modellamento fluviale, sulle quali sono conservati lembi di sedimenti siltoso-argillosi e siltoso-sabbiosi poco addensati e privi di stratificazione (alessio et al., 1982; carraro & valpreda, 1991; dela pierre et al., 2003a) (fig. 1b). lo spessore dei depositi non è mai elevato e comunque inferiore ai 3÷4 m. il grado di alterazione pedogenetica varia da 5÷7,5 yr per i depositi distribuiti sulle dorsali e nelle fasce altimetriche più elevate dei versanti a 7,5÷10 yr per quelli sospesi di pochi metri sugli attuali fondovalle. la configurazione delle superfici di appoggio basale di questi sedimenti appare piuttosto complessa e articolata: i depositi sono infatti conservati in forma di lembi subpianeggianti, sospesi fino ad oltre un centinaio di metri sui fondovalle, in ampie depressioni allungate ad andamento curvilineo e, talvolta, in corrispondenza di selle ubicate nelle fasce più elevate dei versanti. tali superfici rappresentano il prodotto del graduale approfondimento erosivo del reticolato idrografico pregresso in risposta alla contemporanea e progressiva esumazione del rilievo (carraro & valpreda, 1991; dela pierre et al., 2003a) e che ha accompagnato, almeno fino al pliocene superiore (pieri & groppi, 1981; costa, 2003) e al pleistocene medio (enel, 1984), la strutturazione del thrust padano. i corsi d’acqua attuali, allineati in direzione n-s e ne-sw, mostrano nel complesso valori di gerarchizzazione e di densità di drenaggio piuttosto bassi. alla notevole ampiezza dei fondovalle, talvolta superiori al chilometro (es. valle versa e val cerrina), si contrappongono rii caratterizzati da deflussi con portate modeste o quasi nulle, con significativi rapporti di sottodimensionamento rispetto alla sezione dei solchi vallivi. 3. cavità di dissoluzione in tutte le masse di gesso affioranti o subaffioranti nei rilievi del monferrato e della collina di torino è stata rilevata la presenza di un ampio spettro di cavità di dissoluzione. analogamente a quanto accade nei terreni carbonatici, le cavità epigee, ospitate nella fascia pellicolare della successione evaporitica al contatto con le coltri di copertura, e quelle ipogee, individuate all’interno dei banchi gessosi, mostrano una distribuzione spaziale e caratteri morfo-dimensionali ben distinti in relazione ai differenti meccanismi speleogenetici ed evolutivi che hanno operato e operano nei diversi punti del sistema carsico (fig. 3). le forme di dissoluzione sviluppate nella “zona di assorbimento” dei sistemi carsici si concentrano nei primi metri della successione evaporitica: si tratta di cavità cilindriche o imbutiformi ("camini") a sviluppo subverticale, aventi un'altezza non superiore ai 6÷10 m e un'orientazione dell'asse sempre svincolata dall'andamento locale della stratificazione (fig. 4). le cavità hanno una sezione trasversale subcircolare o subellittica, con diametro compreso tra pochi centimetri e un massimo di 5÷6 m; spesso la sezione presenta un graduale restringimento verso il basso che dà luogo a un profilo longitudinale marcatamente conico. le cavità impostate lungo piani o zone di faglia mostrano invece sezioni irregolari e allungate parallelamente alle discontinuità tettoniche. le pareti delle cavità epigee, con superfici di corrosione regolari e prive di asperità, in taluni casi sono solcate da scanalature di piccolo diametro (5÷10 cm) ad andamento longitudinale. talvolta il numero di cavità per unità di superficie è così elevato da generare frequenti rapporti di interferenza, coalescenza e compenetrazione delle diverse forme carsiche: la configurazione dell'interfaccia gesso-coperture risulta in tal modo estremamente irregolare (“hummocky morphology”) e contraddistinta da culminazioni gessose alternate a depressioni con profondità non superiori ai 10 m (fig. 3). nella “zona di percolazione”, e in palese connessione con le forme epicarsiche, è presente un reticolo di condotti più o meno irregolari e scarsamente ramificati, con asse da molto inclinato (65÷80°) a verticale e uno sviluppo longitudinale accertato di alcune decine di metri (20÷30 m) (fig. 3 e 5). la sezione trasversale delle cavità è sensibilmente più irregolare rispetto alle corrispondenti forme epigee, sebbene non sia infrequente osservare condotti con profilo subcircolare o subellittico; anche le dimensioni variano considerevolmente, con diametri non superiori ai 3÷4 m e la presenza di repentini restringimenti di sezione o di vere e proprie strozzature. in alcuni casi i condotti immettono in cavità a sviluppo orizzontale contraddistinte da “soffitti di dissoluzione” perfettamente piatti e da pareti ad acclività variabile: 5÷15° nel caso di cavità con profilo piano-concavo (es. cava di murisengo), 35÷45° nel caso di cavità con profilo trapezoidale rovescio (es. cava di montiglio) (rispettivamente c1 e c2 in fig. 3). la loro altezza è compresa tra 3÷5 cm e un massimo di un metro, mentre in pianta si estendono per non più di una decina di metri. talvolta si rinvengono isolate all'interno della roccia; più frequentemente appaiono raggruppate e irregolarmente distribuite in senso verticale e comunque con un’orientazione sempre svincolata dall'andamento loca459manifestazioni carsiche nelle evaporiti ... le della stratificazione. queste cavità si sviluppano in ammassi selenitici sostanzialmente compatti e privi di disomogeneità tessiturali o di discontinuità (faglie, fratture o superfici di strato) tali da determinare significativi contrasti nei valori di permeabilità e solubilità della roccia. la loro presenza nell’ambito del sistema carsico può quindi essere spiegata chiamando in causa due distinti meccanismi genetici: il primo prevede l'esistenza di prolungati e ripetuti stazionamenti della superficie freatica, correlabili in superficie con episodi di terrazzamento fluviale, che consentirebbero alle acque sottosature in solfati di operare processi di dissoluzione a prevalente sviluppo orizzontale (warren et al., 1990); 460 g. fioraso et al. fig. 3 schema di distribuzione delle forme carsiche di dissoluzione e dei sedimenti di riempimento (non in scala). 1: brecce di collasso (facies “a"); 2: sabbie massive o stratificate (facies “b"); 3: argille e silt massivi o laminati (facies “c"); 4: brecce di estrusione (facies “d"); 5: coltri di copertura sovrastanti la successione evaporitica; 6: gesso; 7: faglie; 8: strutture da “iniezione”; a: camini di dissoluzione epigei; b: condotti di dissoluzione ipogei; c: cavità orizzontali; d: doline di collasso; e: doline di subsidenza. distribution sketch of karst features and filling deposits (not in scale). 1: collapse breccias (facies “a"); 2: bedded or massive sands (facies “b"); 3: massive or laminated silts and clays (facies “c"); 4: extrusion breccias (facies “d"); 5: post-evaporitic cover; 6: gypsum; 7: faults; 8: injection structures; a: epigean dissolution pipes; b: hypogean dissolution conduits; c: horizontal caves; d: cover-collapse sinkholes; e: cover-subsidence sinkholes. fig. 4 cavità di dissoluzione epicarsiche subverticali nella cava gessi di moncalvo. subvertical epikarst dissolution cavities in gessi di moncalvo quarry. nel secondo interverrebbero fenomeni di “stratificazione di densità” dell'acqua indotti dal diverso quantitativo di caso4 · 2h2o disciolto e, conseguentemente, al diverso peso specifico assunto dalla soluzione nei diversi punti delle cavità sature. secondo un modello evolutivo proposto da kempe (1972) e successivamente ripreso da klimchouk (1996b), il continuo apporto di fluidi sottosaturi provenienti dall'epicarso instaurerebbe un gradiente di densità dell'acqua contenuta all'interno delle cavità tale da consentire l’avvio di una lenta circolazione convettiva. lo strato d'acqua superficiale, più leggero e chimicamente più aggressivo nei confronti del gesso, consentirebbe una rapida solubilizzazione del gesso, concentrata nelle parti sommitali e periferiche delle cavità ("dissoluzione marginale"). arricchitasi in ioni solfato e raggiunti valori critici di concentrazione, la soluzione fluirebbe lungo le pareti dando luogo a correnti di densità caratterizzate da un potenziale dissolutivo decrescente procedendo verso la parte più depressa delle cavità. verrebbe in tal modo a configurarsi un sistema di celle convettive dinamicamente controllato dalle piccole e locali variazioni del chimismo (e quindi di densità) della soluzione presente nel circuito sotterraneo, in grado di modellare la volta delle cavità con un meccanismo di "spianamento" da dissoluzione. nel complesso, le cavità ipogee si estendono all’interno dei blocchi evaporitici per una profondità massima di circa 50÷60 m a partire dall’interfaccia gesso-coperture. la distribuzione delle forme carsiche ipogee è tuttavia piuttosto disomogenea: nelle cave sotterranee di montiglio, murisengo e moncalvo, in cui i livelli di coltivazione sono spinti ben al di sotto dei fondovalle, si osserva infatti un repentino diradamento delle cavità procedendo verso le parti più profonde delle masse gessose, cui si accompagna una diminuzione del loro diametro medio. il fronte di dissoluzione si arresta quasi completamente in prossimità o pochi metri al di sotto degli attuali fondovalle alluvionali. inoltre, il grado di interconnessione idraulica tra le diverse cavità appare, quanto meno a scala macroscopica, piuttosto basso, vista l'assenza di gallerie di trasferimento orizzontali anche di piccolo diametro. questi elementi concorrono nell'indicare una sensibile attenuazione dell'intensità dei processi di dissoluzione già a pochi metri dall'ingresso nel sistema carsico delle acque di percolazione: ciò confermerebbe l'esistenza di un limite fisico verticale allo sviluppo del carsismo, che risulterebbe confinato al di sopra del livello di base del sistema idrologico ipogeo, a sua volta in raccordo con il reticolato idrografico superficiale (klimchouk, 1996c). 4. fenomeni di subsidenza e collasso superficiali la rapidità evolutiva del carso gessoso trova riscontro anche in aree, come quelle del monferrato e della collina di torino, nelle quali l'elevato impatto antropico rappresentato dalle attività agricole causa spesso un intenso e costante rimodellamento del rilievo naturale. nonostante questa difficoltà è infatti possibile distinguere con chiarezza gli effetti indotti dal risentimento superficiale dei fenomeni di dissoluzione. tali effetti possono essere efficacemente descritti come combinazione di due distinti meccanismi genetici, che danno luogo ad altrettante e ben diverse morfologie (fig. 3): "doline di subsidenza" (subsidence doline, jennings, 1985; subsidence sink, arrington & lindquist, 1987; cover-subsidence sinkhole, tihansky, 1999). si tratta di depressioni chiuse o semiaperte, di forma subcircolare o ellittica, con un diametro massimo di circa 200 m (es. pirenta di murisengo) e una profondità non superiore ai 4÷5 m. la loro presenza è stata documentata in tutta l'area di affioramento del ctv (fioraso & boano, 2002); in alcuni settori, quale quello compreso tra gli abitati di cocconato e montiglio, la densità dei fenomeni è così elevata da conferire ai versanti una complessa quanto irregolare morfologia a dossi e depressioni. le doline di subsidenza si sviluppano a seguito della dissoluzione che avviene al contatto gesso-coperture, spesso accompagnata da fenomeni di piping (o “suffosione”, sensu castiglioni, 1986) che causano il trasferimento dei sedimenti siltoso-sabbiosi e argillosi superficiali all'interno dei circuiti carsici: le coltri di copertura, prive di un sufficiente grado di autoportanza, si assestano dando così luogo ad una localizzata subsidenza della superficie topografica (fig. 6). il fenomeno evolve gradualmente e in tempi relativamente brevi (se confrontati con analoghi fenomeni sviluppati in ambienti carbonatici), parallelamente al procedere della 461manifestazioni carsiche nelle evaporiti ... fig. 5 reticolo di condotti carsici ipogei messi in luce lungo i gradoni di coltivazione della cava di moncucco t.se. hypogean dissolution conduits exhumed along benches by exploitation activity in moncucco t.se quarry. dissoluzione nell'epicarso e all'ampliamento delle cavità e dei condotti ipogei; "doline di collasso" (subjacent karst collapse doline, jennings, 1985; arrington & lindquist, 1987; covercollapse sinkhole, tihansky, 1999). si tratta di depressioni chiuse subcircolari di diametro inferiore ai 15÷20 m e una profondità di alcuni metri, delimitate da scarpate molto acclivi o subverticali che configurano una sezione trasversale cil indrica o a imbuto. rispetto ai fenomeni di subsidenza, le doline di collasso presentano un più elevato rapporto profondità/diametro. i fenomeni di collasso, osservati e segnalati nei settori di montiglio, murisengo e guazzolo, sono causati dall'infiltrazione dei sedimenti di copertura siltoso-argillosi nei sottostanti condotti carsici ad opera di fenomeni di piping che inducono la formazione di cavità a cupola al contatto con i banchi di gesso (fig. 6): il continuo e graduale distacco di materiale provoca la migrazione verso l'alto del tetto della cavità e l'assottigliamento della volta che permane in condizioni di stabilità fintanto che le sollecitazioni, ridistribuite nell'intorno del vuoto secondo uno schema "ad arco", non superano la resistenza della calotta. oltrepassato tale limite la volta, non più in grado di sorreggere il proprio peso, collassa causando l'improvviso sprofondamento della superficie. il fenomeno avviene generalmente in tempi rapidi (talvolta nell'arco di pochi minuti o ore) e in occasione di eventi piovosi significativi e prolungati che inducono una variazione del contenuto in acqua, e quindi della plasticità, delle coltri di copertura. le doline di collasso risultano inoltre di gran lunga meno numerose rispetto a quelle di subsidenza, anche perché spesso tempestivamente riempite con materiali di riporto; a ciò si aggiunge l'effetto dei processi erosivi e di rimodellamento che possono in breve tempo mutare l'originario aspetto delle cavità di collasso in semplici depressioni chiuse. 462 g. fioraso et al. fig. 6 meccanismi genetici delle doline di subsidenza e di collasso (modificato da tihansky, 1999). 1: gesso; 2: coltri di copertura; 3: prodotti residuali della dissoluzione e riempimenti; 4: cavità carsiche. evolutionary model of cover-subsidence and cover-collapse sinkholes (from tihansky, 1999, modified). 1: gypsum; 2: sedimentary cover; 3: residual sediments and filling deposits; 4: karst cavities. fig. 7 dolina di collasso di circa 70 m di diametro impostata al contatto tra il membro siltosoargilloso delle argille azzurre e il ctv, fra gli abitati di cocconato e montiglio. alcuni sondaggi effettuati 200 m circa più a nord hanno intercettato, a profondità comprese tra gli 11 e i 16 m, numerose cavità carsiche prive di riempimenti e di dimensioni comprese tra 0,5 e 4 m. cover-collapse sinkhole, 70 m in diameter, located at the contact between ctv and argille azzurre silty-clayey member, between cocconato and montiglio villages. some drill-holes placed 200 m to the north intercepted many karst cavities at a depth of 11÷16 m. karst features have a diameter of 0,5÷4 m and are devoid of sediments. le doline osservabili nel monferrato mostrano spesso caratteri morfologici intermedi tra i fenomeni puri di subsidenza e di collasso (fig. 7): ciò è da mettere in relazione da un lato con le diverse possibili combinazioni dei meccanismi genetici descritti, dall'altro con la composizione granulometrica e lo spessore delle coltri di copertura coinvolte. le doline di subsidenza si concentrano infatti in aree nelle quali la matrice marnoso-argillosa del ctv è caratterizzata da spessori non superiori a qualche decina di metri: coltri più potenti, infatti, attenuano il risentimento superficiale del fenomeno di assestamento al punto da risultare morfologicamente impercettibile. le doline di collasso si verificano invece in aree nelle quali lo spessore delle coltri di copertura è relativamente modesto e indicativamente inferiore ai 10÷15 m: minore, infatti, è il volume dei sedimenti coinvolto, più immediate e appariscenti risulteranno le manifestazioni di sprofondamento. 5. riempimenti carsici la presenza di una coltre di copertura pressoché continua al di sopra dell'intervallo evaporitico ha consentito, parallelamente al procedere della dissoluzione, il trasferimento di ingenti quantità di sedimenti all’interno dei circuiti carsici (fig. 3). ciò ha causato il riempimento e l'occlusione di considerevoli tratti del reticolato ipogeo, interferendo sulle modalità di circolazione delle acque sotterranee e condizionando i processi dissolutivi in atto nelle zone attive e più profonde dei sistemi. l'eterogeneità delle successioni al tetto dei banchi di gesso, alquanto diversificate in termini di facies, spessore ed età, rende indubbiamente più intricata l'interpretazione dei meccanismi di piping. tuttavia, pur in assenza di chiari limiti spaziali tra lo sviluppo della morfogenesi carsica epigea e di quella ipogea, soprattutto in un ambiente con una spiccata dinamica evolutiva quale quello che caratterizza il carso gessoso, nelle cavità del monferrato e della collina di torino è stato possibile riconoscere almeno quattro distinte facies di riempimento: “brecce di collasso”; “argille e silt massivi o laminati”; “sabbie massive o stratificate”; “brecce di estrusione”. facies “a”: brecce di collasso rappresentano la facies di gran lunga più diffusa nell’ambito dell'epicarso: è costituita da sedimenti caotici di aspetto brecciato, con clasti poligenici angolosi di taglia compresa tra 0,2 e 2÷3 cm immersi in una scarsa matrice siltoso-argillosa o siltoso-sabbiosa (fig. 8). i clasti sono costituiti da frammenti di marne argillose e argille cui si aggiungono, in percentuali variabili, frammenti millimetrico-centimetrici di calcari concrezionali e vacuolari: in questi ultimi le microcavità, spesso di forma prismatica e di taglia millimetrica, sono vuote o riempite da calcite spatica e riproducono fedelmente la forma di originari cristalli di gesso cresciuti in una matrice siltoso-argillosa. all'interno delle brecce si rinvengono talvolta clasti di gesso di taglia compresa tra 1÷2 cm e 15÷20 cm (es. cava gessi di moncalvo). ai corpi brecciati sono talvolta associate tasche e lenti di spessore centimetrico-decimetrico di sabbie siltose a stratificazione piano-parallela orizzontale in posizione marginale e al contatto con le pareti delle cavità. le brecce derivano in gran parte dallo smantellamento delle coltri di copertura poste al tetto delle bancate gessose, costituite in primo luogo dai termini postevaporitici del ctv e dal membro siltoso-argilloso delle argille azzurre (cfr. fig. 2). un ulteriore apporto proviene dalla rielaborazione dei sedimenti “residuali” prodotti dalla concentrazione, all’interfaccia gesso-coperture, delle frazioni carbonatica, argillosa e quarzosa, insolubili o relativamente meno solubili, presenti all’interno del mosaico selenitico in percentuali comprese tra il 2 e il 5% (occella, 1958). le brecce possono essere interpretate come il prodotto del collasso gravitativo delle coltri di copertura all'interno delle cavità epicarsiche, con meccanismi che possono differire sensibilmente da luogo a luogo: in alcuni casi il riempimento si verifica a seguito del collasso della volta di vuoti epigei con conseguente rapida occlusione delle cavità (cfr. doline di collasso; fig. 6); in altri casi si tratta di un più graduale assestamento delle coltri di copertura, conseguente alla lenta dissoluzione epidermica del gesso e all’allargamento e all'approfondimento delle depressioni carsiche preesistenti (cfr. doline di subsidenza). lungo alcuni fronti di cava (es. moncalvo e bricco di murisengo) sono state individuate strutture da "iniezione" (sensu castellarin, 1982, e marabini & vai, 1989), localizzate all'interno di cavità cilindriche di grande diametro (3÷5 m) (fig. 3). si tratta di porzioni anche cospi463manifestazioni carsiche nelle evaporiti ... fig. 8 condotto epigeo a sviluppo verticale colmato da brecce di collasso (cava gessi di moncalvo). vertical epigean cavity filled with collapse breccia (gessi di moncalvo quarry). cue di marne e marne argillose biancastre compatte, iniettate (presumibilmente in condizioni di saturazione d'acqua ed elevata plasticità) all'interno delle cavità: il nucleo mostra una struttura caotica e disorganizzata, mentre i contatti con i sedimenti incassanti e con il gesso, sempre di natura discordante, sono netti e marcati da millimetriche fasce di frizione a struttura laminata (scaly fabric). gli episodi di riempimento delle cavità epicarsiche possono manifestarsi in un'unica soluzione oppure, in alternativa, come una successione di distinti eventi deposizionali. e' il caso di una cavità fusoidale messa in luce nella cava gessi di moncalvo, nella quale un nucleo di argillemarnose biancastre è avvolto da un rivestimento di 5÷20 cm di spessore costituito da silt sabbiosi porosi e privi di strutture (fig. 9); il contatto tra i due sedimenti è netto e non risulta dislocato dalle numerose superfici di scorrimento presenti invece all'interno del nucleo argilloso. in questo caso la polifasicità del riempimento è presumibilmente legata alla contrazione del nucleo argilloso per perdita del suo contenuto in acqua, che ha reso disponibile, all'interno della cavità, ulteriore spazio per lo sviluppo di un tardivo episodio di riempimento. facies “b”: argille e silt massivi o laminati costituiscono il riempimento di cavità ipogee a sviluppo orizzontale e, secondariamente, di alcuni tratti di camini e fusoidi (fig. 3). si tratta di sedimenti argillosi, siltoso-argillosi e siltosi di colore beige a laminazione piano-parallela orizzontale, con lamine di spessore millimetrico o decimillimetrico (fig. 10); con l'aumentare della frazione argillosa la laminazione svanisce lasciando il posto a una struttura massiva omogenea. la potenza di questi sedimenti è raramente superiore al metro, costituendo spesso intercalazioni irregolari e discontinue di modesto spessore (0,5÷10 cm) all'interno delle altre facies di riempimento. la presenza di argil le massive o finemente laminate può essere ricondotta alla decantazione di sedimenti trasportati in sospensione dalle acque di percolazione all'interno di cavità periodicamente soggette a episodi di allagamento. le asperità create dalla deposizione di clasti di taglia centimetrico-millimetrica, provenienti dalle parti più elevate del circuito ipogeo, vengono regolarizzate da drappeggi di argille e silt legati a successivi episodi di decantazione. all'interno dei condotti carsici la laminazione è spesso disturbata dalla presenza di soft sediment deformations indotte da fenomeni di collasso gravitativo (fig. 11): esse si manifestano in primo luogo con blande ondulazioni a scala centimetrico-decimetrica e, meno frequentemente, con convoluzioni a stretto rag464 g. fioraso et al. fig. 9 nucleo di marna argillosa biancastra avvolto da un riempimento secondario di silt sabbiosi in una cavità messa in luce nella cava di gessi di moncalvo. karst cavity in gessi di moncalvo quarry with a core of clayey marl enveloped by secondary sandy silt coating. fig. 10 cavità a sviluppo orizzontale nella cava di montiglio. il riempimento, di circa 35 cm di spessore, è costituito da argille siltose laminate contenenti livelli sabbiosi di spessore centimetrico-millimetrico. horizontal cavity inside montiglio quarry. karst infill (35 cm in thick) is made-up of laminated clay and silty-clay with thin (centimetric to millimetric) sandy layers. gio di curvatura; queste strutture possono essere accompagnate da sgradinamenti dei livelli argillosi ad opera di gruppi di "faglie di gravità" dirette, ad alto angolo, con rigetti massimi di 2÷5 cm. le strutture descritte sono l'espressione di fenomeni di richiamo e insaccamento delle argille e dei silt saturi d'acqua verso le zone assiali delle cavità, per effetto del drenaggio e consolidamento dei sedimenti; in altri casi le deformazioni avvengono a causa della rimozione o del crollo del supporto basale del riempimento carsico, innescato dal trasferimento di una parte dei sedimenti nei settori più profondi e liberi del reticolo carsico. i riempimenti siltoso-argillosi sono spesso attraversati da filoncelli di esiguo spessore (al massimo 5÷6 mm) e sviluppo centimetrico-decimetrico, disposti ortogonalmente rispetto all'andamento della laminazione e contenenti sedimenti a granulometria più grossolana (sabbie e clasti argillosi millimetrici). anche queste strutture (mud cracks) sono causate dalla variazione del contenuto in acqua nelle argille e confermano la presenza di periodiche oscillazioni del livello della superficie freatica all'interno delle cavità, con episodi di disseccamento e contrazione dei sedimenti seguiti da nuove fasi di saturazione e riempimento. facies “c”: sabbie massive o stratificate ampiamente diffusa entro i condotti carsici ipogei a sviluppo verticale (fig. 3), questa facies è costituita da sabbie, sabbie siltose e sabbie ghiaiose a stratificazione piano-parallela e gradazione da normale a inversa. talvolta gli intervalli sabbiosi sono privi di strutture e si presentano con un aspetto massivo (fig. 12). la frazione ghiaioso-sabbiosa è rappresentata da clasti carbonatici di taglia millimetrica, arrotondati o subangolosi, e da granuli tondeggianti neri di ossidi di fe-mn di 0,5÷3 mm di diametro; in quantità subordinate si rinvengono frammenti di gusci di bivalvi e gasteropodi, macroforaminiferi bentonici e granuli di quarzo. il rapporto percentuale dei diversi componenti varia sensibilmente da un sistema carsico all'altro: in alcune cavità della cava di grana m.to, ad esempio, l'abbondanza di ossidi di fe-mn è tale da conferire alle sabbie una marcata colorazione bruna. tale circostanza è legata alla diversa composizione delle coltri di copertura situate nei punti di ingresso dei circuiti ipogei e ai diversi meccanismi di selezione, trasporto e concentrazione meccanica operanti nelle cavità di dissoluzione. le facies sabbiose costituiscono il prodotto dell'azione di fenomeni di piping e di correnti trattive in grado di veicolare sedimenti, talvolta anche grossolani, nel reticolato carsico ipogeo. 465manifestazioni carsiche nelle evaporiti ... fig. 11 alternanza di sedimenti siltoso-argillosi laminati (a) e sabbioso-siltosi (b), costituenti il riempimento di un condotto carsico di piccolo diametro (20÷22 cm) nella cava di grana m.to. i diversi livelli cromatici corrispondono a distinti episodi di riempimento della cavità. succession of laminated silty clay (a) and sandy silt (b) inside hypogean dissolution conduit 20÷22 cm in diameter (grana m.to quarry). every level correspond to a distinct episode in the infill sequence. all'interno dei riempimenti sabbiosi sono spesso presenti livelli e tasche di depositi siltoso-argillosi o, più frequentemente, clasti millimetrico-centimetrici argillosi di forma irregolare, provenienti dallo smantellamento dei tappi di sedimenti presenti nei tratti superiori dei condotti carsici. anche i sedimenti sabbiosi sono frequentemente destrutturati per la presenza di fenomeni di collasso simili a quelli descritti per le facies argillose (es. insaccamenti e dislocazioni di piccola entità): tuttavia, l'elevata permeabilità delle sabbie consente da un lato di escludere un legame delle deformazioni con la variazione del contenuto in acqua, dall'altro di ipotizzare fenomeni di assestamento dovuti al trasferimento dei sedimenti sottostanti nelle porzioni inferiori delle cavità. facies “d”: brecce di estrusione sono costituite da ammassi caotici di argille, siltargillosi e sabbie contenenti sporadici clasti carbonatici e talvolta piccoli frammenti di gesso (fig. 13). mostrano una struttura da brecciata a massiva con clasti e porzioni di sedimenti variamente deformati (ma al cui interno sono talvolta ancora preservate le originarie strutture sedimentarie) derivanti dalla rielaborazione delle facies descritte in precedenza. le brecce costituiscono il tipo di riempimento prevalente all'interno dei condotti carsici, rappresentando spesso l'unica facies presente (cfr. fig. 3). l'organizzazione interna delle brecce e i rapporti con le altre tipologie di riempimento, con le quali peraltro risultano spesso variamente associate, consentono di chiamare in causa per la genesi di questi sedimenti due distinti meccanismi: "autoclastismo", fenomeno guidato dalla gravità che comporta in un primo momento il graduale collasso e frammentazione delle originarie facies di riempimento (fig. 14), successivamente il trasferimento dei sedimenti nelle parti più profonde e libere dei condotti carsici sviluppatisi nel frattempo e la loro completa destrutturazione e caoticizzazione. il fenomeno si sviluppa a seguito dell'incremento del contenuto in acqua e del grado di plasticità dei materiali di riempimento. le diverse tappe e i diversi gradi evolutivi del fenomeno sono riconoscibili con buon dettaglio nelle cavità messe in luce nella cava di grana m.to, in cui risultano coinvolte alternanze di sabbie e silt argillosi laminati; "estrusione", fenomeno che si sviluppa quando all'interno dei condotti ipogei vengono a trovarsi tappi di sedimenti con un'elevata frazione siltoso-argillosa e quindi poco permeabili. anche in questo caso l'ingresso nel sistema carsico di consistenti volumi di acqua di percolazione porta in un primo momento all'imbibizione e alla saturazione dei sedimenti, successivamente a un incremento della loro plasticità: raggiunti valori critici di viscosità (di volta in volta controllati dalla composizione granulometrica del materiale di riempimento e dalla forma e dalle dimensioni della cavità), l'aumento di pressione legato al carico idraulico gravante sul tappo consente a quest'ultimo di essere gradualmente sospinto (ed "estruso" nei punti di maggiore restringimento dei condotti) e di fluire verso i tratti più profondi e liberi del circuito ipogeo. l'attrito esercitato dalla massa in movimento lungo le pareti della cavità comporta un grado di destrutturazione tale da fare assumere alla matrice siltoso-argillosa una struttura caotica, talvolta accompagnata da strutture di frizione al contatto con le pareti gessose. fenomeni di estrusione, del tutto simili a quell i segnalati in cavità carsiche nei gessi dell'appennino bolognese (trebbi, 1926), sono stati osservati nelle cave di montiglio e murisengo: alcune gallerie estrattive risultano infatti parzialmente o totalmente ostruite da imponenti colate di argille siltose estruse attraverso le numerose cavità carsiche, anche di piccolo diametro (25÷40 cm), intercettate dai fronti di coltivazione (fig. 15). 6. analisi biostratigrafica dei riempimenti carsici l'abbondanza delle microfaune riscontrate all'interno delle cavità carsiche ha fornito l'opportunità di individuare le aree sorgenti dei sedimenti in esse contenuti. a tale scopo è stata effettuata una serie di campionamenti in alcune cavità individuate nelle cave di grana m.to (cmp. grn-1), gessi di moncalvo (cmp. mnc-1, mnc-2 e mnc-3), montiglio (cmp. mnt-1 e mnt-2) e moncucco t. se (cmp. mc-12, mc-13 e mc23) (cfr. fig. 2). le analisi hanno consentito di caratterizzare, sulla base dell’associazione a foraminiferi 466 g. fioraso et al. fig. 12 sedimenti sabbiosi con clasti e intercalazioni siltosoargillose all'interno di un condotto carsico subverticale di circa 80 cm di diametro (cava di grana m.to). karst infill made-up of sands with silty-clayey lenses and chips inside subvertical dissolution conduit 80 cm in diameter (grana m.to quarry). planctonici, 6 dei 9 campioni esaminati (tab. 1), mentre l’analisi delle associazioni a foraminiferi bentonici ha fornito un quadro delle condizioni paleoambientali durante le quali i sedimenti andavano in origine a depositarsi (tab. 2). grana m.to: campione grn-1 il campione è stato prelevato in corrispondenza dell'unico livello di coltivazione presente nella dismessa cava in sotterraneo di grana m.to (fig. 2, sez. a-a'). si tratta di una complessa associazione di sedimenti sabbiosi e sabbioso-siltosi stratificati (facies "c") di colore variabile dal bruno al nocciola e variamente deformati, presenti all'interno di un articolato sistema di cavità che attraversano verticalmente il banco di gesso (cfr. fig. 12). l'analisi biostratigrafica ha 467manifestazioni carsiche nelle evaporiti ... fig. 13 melange di sedimenti siltoso-argillosi estrusi lungo un condotto carsico di circa 60 cm di diametro (cava di grana m.to). melange of silty-clayey sediments extruded along hypogean dissolution conduit 60 cm in diameter (grana m.to quarry). fig. 14 fenomeno di piping all'interno di un condotto carsico di piccole dimensioni (10÷15 cm di diametro) nella cava di grana m.to. piping phenomenon inside karst conduit 10÷15 cm in diameter (grana m.to quarry). fig. 15 solchi prodotti dall'estrusione di argille siltose attraverso una cavità carsica ubicata al tetto del terzo livello di coltivazione della cava di montiglio. furrows over a silty clay slub extruded from karst conduit at the roof of the workings in the third level of montiglio quarry. 468 g. fioraso et al. tab. 1 associazioni a foraminiferi planctonici riscontrate nei sedimenti di riempimento dei condotti carsici. assemblages of planktic foraminifers inside endokarst deposits. catapsydrax dissimilis x catapsydrax unicavus x dentoglobigerina altispira x globigerina apertura x globigerina bulloides x x globigerina decoraperta x globigerina falconensis x globigerina multiloba x globigerina nepenthes x globigerina praebulloides x x globigerina venezuelana x x globigerinita glutinata x globigerinoides bisphericus* x globigerinoides extremus x x globigerinoides obliquus x globigerinoides obliquus extremus x x globigerinoides quadrilobatus x globigerinoides sacculifer x x g r n -1 m n t1 m n t2 m c -1 2 m c -1 3 m c -2 3 globigerinoides sp. x globigerinoides subquadratus x globigerinoides trilobus x x globoquadrina baroemoenensis* x globoquadrina dehischens x x globoquadrina praedehischens* x globorotalia margaritae (rara) x x globorotalia menardii x globorotalia puncticulata x x globorotalia scitula x x globorotalia sp. x hastigerina siphonifera x neogloboquadrina acostaensis x neogloboquadrina dutertrei x orbulina bilobata x orbulina universa x x orbulina suturalis x x paragloborotalia mayeri x turborotalita quinqueloba x x x g r n -1 m n t1 m n t2 m c -1 2 m c -1 3 m c -2 3 ammonia beccarii x anomalinoides granosus x anomalinoides helicinus x anomalinoides ornatus x bolivina miocenica x brizalina arta x brizalina sp. x bulimina aculeata x bulimina echinata* x bulimina minima x cancris auriculus x cassidulina carinata x cibicides sp. x cibicidoides kullenbergi x cibicidoides pachydermus x cibicidoides pseudoungerianus x x cibicidoides robertsonianus x elphidium crispum x globobulimina affinis x globocassidulina subglobosa x gyroidinoides neosoldanii x gyroidinoides sp. x heterolepa bellincionii x heterolepa dertonensis x lenticulina calcar x lenticulina cultrata x lenticulina curvisepta x lenticulina inornata x lenticulina orbicularis x lenticulina rotulata x g r n -1 m n t1 m n t2 m c -1 2 m c -1 3 m c -2 3 lenticulina spinulosa x marginulina costata x marginulina crebricosta x martinottiella communis x x melonis barleanum x melonis pompilioides x melonis soldanii x neoeponides schreibersi x nodosaria raphanistrum x nodosaria raphanus x oridorsalis umbonatus x orthomorphina sp. x planulina ariminensis x x pullenia bulloides x pullenia salisbury x rectouvigerina siphogenerinoides x x saracenaria italica x sigmoilinita tenuis x siphonina reticulata x x sphaeroidina bulloides x spiroplectinella wrighty x stilostomella sp. x x textularia agglutinans x textularia soldanii x uvigerina auberiana x uvigerina pygmaea x uvigerina rutila x uvigerina striatissima x vaginulinopsis striatissima x vulvulina pennatula x g r n -1 m n t1 m n t2 m c -1 2 m c -1 3 m c -2 3 tab. 2 associazioni a foraminiferi bentonici riscontrate nei sedimenti di riempimento dei condotti carsici. assemblages of benthonic foraminifers inside endokarst deposits. messo in luce un'abbondante associazione a prevalenti foraminiferi bentonici e foraminiferi planctonici, cui si associano ostracodi, frammenti di echinidi e rari ittioliti. gli esemplari sono generalmente ben conservati e spesso di grandi dimensioni. sono stati rinvenuti in percentuali significative anche frammenti di gusci di bivalvi e di gasteropodi. nella frazione inorganica sono diffusamente presenti aggregati e concrezioni carbonatiche, cui si aggiungono, in percentuali minori, granuli millimetrici di ossidi di fe-mn, pirite e glauconite, queste ultime anche come modelli interni di foraminiferi. la presenza di globorotalia margaritae e di globorotalia puncticulata (tab. 2) consente di attribuire al pliocene inferiore (zancleano, zona mpl3; cita, 1975; rio et al., 1994) l’età delle associazioni. tra i taxa bentonici altre forme coeve, o con diffusione a tutto il pliocene inferiore, sono rappresentate da anomalinoides granosus, anomalinoides helicinus, anomalinoides ornatus, heterolepa bellincionii, heterolepa dertonensis, lenticulina spinulosa, uvigerina rutila e vaginulinopsis striatissima. l’associazione sembra indicativa della zona epibatiale superiore (scarpata continentale, prossima al margine della piattaforma), mentre la frequenza di esemplari di grandi dimensioni (in particolare di lenticulina spp. e di nodosaria spp.) sembra suggerire condizioni ambientali ottimali per i taxa. i risultati delle analisi consentono di interpretare i riempimenti delle cavità di grana m.to come il prodotto dell'infiltrazione e della rielaborazione di originari sedimenti riferibili al membro siltoso-argilloso delle argille azzurre (faa/9 in fig. 2). questa unità affiora estesamente lungo la sommità della dorsale collinare entro cui è impostato il giacimento di gesso, ed è separata dai sottostanti sedimenti del ctv da una discontinuità stratigrafica a valenza regionale (dela pierre et al., 2003a). gessi di moncalvo: campioni mnc-1, mnc-2 e mnc-3 i campioni sono stati prelevati lungo i fronti di coltivazione, attualmente dismessi, della cava a cielo aperto ubicata in località gessi di moncalvo: mnc-1 costituisce il riempimento siltoso e siltoso-sabbioso stratificato (facies "b" e "c") di una cavità a sviluppo orizzontale localizzata all'interno del terzo banco gessoso; mnc-2 è costituito da marne argillose biancastre provenienti dal nucleo di una cavità intercettata dagli scavi lungo il terzo banco (cfr. fig. 9); le argille massive del campione mnc-3 sono state infine prelevate all'interno di un piccolo fusoide localizzato entro il ciclo evaporitico inferiore (fig. 2, sez. b-b'). tutti i campioni sono risultati sterili dal punto di vista faunistico. solo in mnc-1 è stato rilevato un melange di resti di organismi marini, fra i quali rarissimi radioli di echinodermi e otoliti di pesci, e di organismi terrestri, fra i quali un molare di micromammifero non determinabile. pertanto, è probabile che in questo settore l'infiltrazione di sedimenti nelle cavità carsiche sia avvenuto a spese di originarie marne siltose biancastre, localmente costituenti la matrice del ctv, che risultano sterili o caratterizzate da associazioni a foraminiferi poco significative (dela pierre et al., 2003a). montiglio: campioni mnt-1 e mnt-2 i campioni provengono rispettivamente dal primo e dal terzo livello di coltivazione della dismessa cava in sotterraneo di montiglio (fig. 2, sez. c-c'), il cui imbocco è posto poche decine di metri a sud dall'alveo del t. versa. per mnt-1 si tratta di sedimenti sabbiosi e argillosi grigi stratificati (facies "b" e "c"), contenenti locali concentrazioni di molluschi dulcicoli (planorbis sp.), ospitati in un ampio e irregolare condotto subverticale parzialmente percorribile; mnt-2 è invece costituito da argille massive e silt argillosi laminati beige (facies "b") ospitati in una cavità a sviluppo orizzontale (cfr. fig. 10). la frazione inorganica è formata da sabbie carbonatiche, noduli millimetrici di ossidi di fe-mn e granuli di pietre verdi, quarzo e muscovite. in entrambi i campioni le associazioni a foraminiferi risultano piuttosto ricche. in particolare, in mnt-1 è stata riscontrata una fauna ottimamente conservata di età pliocenica inferiore (zancleano, zona mpl4a), caratterizzata dalla presenza di globorotalia puncticulata. in associazione sono state rinvenute specie fortemente ricristallizzate, e talora deformate, attribuibili al messiniano, al burdigaliano superiore e al burdigaliano inferiore (evidenziate con * in tab. 2), indicative di un importante melange faunistico. l’associazione a foraminiferi bentonici risulta piuttosto varia ed è caratterizzata da specie infaunali ed epifaunali ialine tipiche della zona epibatiale inferiore mesobatiale (scarpata continentale). per quanto concerne invece il campione mnt-2, l’associazione a foraminiferi è molto più scarsa. la presenza di catapsydrax dissimil is , c. unicavus e globoquadrina dehischens consente tuttavia di attribuire come età limite superiore dei sedimenti il miocene inferiore (burdigaliano, zona n5/6; novaretti et al., 1995). dal punto di vista paleoambientale l’associazione sembrerebbe invece indicativa della zona epibatiale superiore. il mixing faunistico che caratterizza i campioni mnt-1 e mnt-2 trova riscontro nelle particolari associazioni a foraminiferi (riferibili all'intervallo compreso tra l'eocene e il messiniano inferiore) riconosciute da dela pierre et al. (2002) nelle mud breccias del complesso caotico di parona, affioranti nell'area circostante le cave di montiglio, sul versante sinistro della valle versa: secondo questi autori la presenza di simili miscelazioni sarebbe da ricondurre a meccanismi di gravity sliding e di diapirismo, attivi nel messiniano superiore, che avrebbero smembrato l'intervallo evaporitico già deposto e coinvolto localmente anche i termini della successione pre-messiniana. la presenza di associazioni a microfossili di età pliocenica inferiore (zona mpl4a) deriverebbe invece dall'infiltrazione nel sistema carsico di sedimenti riferibili al membro silsoso-argilloso delle argille azzurre, affiorante 300 m a se dell'imbocco della cava. moncucco t.se: campioni mc-12, mc-13 e mc-23 i campioni mc-12 e mc-13 sono costituiti da argille massive di colore beige (facies "b") e provengono da due cavità messe in luce lungo il primo livello di coltivazione della cava di moncucco t.se (fig. 2, sez. d-d'). il campione mc-23, costituito da argille marnose verdi (facies "b"), proviene invece da una cavità ubicata in corrispondenza del quarto livello di coltivazione (fig. 2, sez. d-d’). i campioni mc-12 e mc-13 mostrano caratteri similari e sono caratterizzati da una microfauna piuttosto scarsa e di dimensioni estremamente ridotte (cfr. 469manifestazioni carsiche nelle evaporiti ... tabb. 2 e 3). in mc-12 la presenza di globigerina multiloba è indicativa di un’età miocenica superiore (messiniano, subzona a globigerina multiloba, d’onofrio et al., 1975), mentre in mc-13 la presenza di globigerina quinqueloba permette di attribuire un’etàlimite inferiore delle microfaune al miocene superiore (tortoniano, zona n17). i rarissimi foraminiferi bentonici rinvenuti appartengono a specie infaunali ialine tipiche di fondali fangosi e talora disossici: in questo caso la scarsità di ossigenazione giustificherebbe le ridotte dimensioni degli organismi rinvenuti. mc-23 si discosta notevolmente dai precedenti campioni in quanto costituito da una microfauna ricca, diversificata e ben conservata. globorotalia margaritae è indicativa di un’età pliocenica inferiore (zancleano, zona mpl2). la microfauna bentonica, caratterizzata da forme infaunali ialine e agglutinanti, sembra indicativa della zona epibatiale (scarpata continentale). i risultati delle analisi riflettono la particolarità dell'assetto stratigrafico e strutturale recentemente riconosciuto nella zona di moncucco t.se (polino, 2002; irace et al., 2002): la presenza in mc-12 di globigerina multiloba deriverebbe dal trasferimento, all'interno del sistema carsico, di sedimenti appartenenti ai termini messiniani delle marne di s. agata fossili, che nell'area di cava risultano direttamente giustapposte all'intervallo evaporitico tramite un duplice sistema di faglie transpressive a direzione n170÷180° (festa et al., 2002); le associazioni fossilifere di età pliocenica inferiore presenti nel campione mc-23 proverrebbero invece dalla rielaborazione di sedimenti riferibili al membro siltosoargilloso delle argille azzurre che sigillano, con una superficie di discontinuità, la sottostante successione miocenica. 7. distribuzione dei sistemi carsici la localizzazione e la tipologia delle manifestazioni carsiche riscontrate nel monferrato e nella collina di torino appaiono strettamente dipendenti da un lato dall'assetto stratigrafico e strutturale localmente assunto dal ctv, dall'altro dall'entità dell'esumazione dei rilievi collinari intercorsa nell'intervallo pliocenico-quaternario. a partire dalla direttrice chieri altavilla m.to, lungo la quale affiora in modo pressoché ininterrotto, il ctv immerge mediamente di 2÷5° verso le aree depocentrali di alessandria (a est) e di carmagnola villanova d'asti (a ovest). in questa fascia il ctv risulta inoltre confinato al di sotto di una potente coltre di copertura pliocenico-quaternaria costituita dalle argille azzurre, dalle sabbie di asti e dal complesso "villafranchiano" auct., rappresentato dalle sabbie di ferrere, dai silt di s. martino e dal sintema di morialdo (carraro, 1996; boano & forno, 1999; dela pierre et al., 2003a). nel dettaglio, tuttavia, l'orientazione delle bancate gessose risulta in molti punti molto meno regolare e soprattutto appare svincolata rispetto all'andamento regionale del ctv. quest'ultimo è stato inoltre esposto a un tasso di esumazione progressivamente maggiore procedendo da sud verso nord, in accordo con il carattere differenziale delle deformazioni tettoniche che hanno accompagnato la strutturazione del thrust frontale padano (pieri & groppi, 1981; costa, 2003). al contempo si è verificata la graduale dissezione del nascente rilievo collinare (e conseguentemente del ctv) da parte del reticolato idrografico locale, le cui tracce, in forma di superfici terrazzate e di lembi di depositi, sono diffusamente conservati sul versante sud della dorsale collina di torino monferrato (polino, 2002; dela pierre et al., 2003a). questa evoluzione ha imposto, nel tempo, chiari vincoli fisici all'impostazione e allo sviluppo dei fenomeni dissolutivi, che risultano inevitabilmente condizionati dal contesto morfologico superficiale: l'emersione del rilievo collinare ha infatti consentito l'instaurazione del gradiente idrodinamico necessario alle acque di percolazione per defluire dai settori di alimentazione alle aree in cui le stesse, una volta permeati gli ammassi gessosi, vengono restituite al reticolato idrografico di superficie, che di norma avviene in corrispondenza del punto di raccordo tra il livello di base carsico e gli attuali fondovalle alluvionali. alla luce dei dati fin qui esposti, i fenomeni di dissoluzione descritti possono essere inquadrabili in un carso di "interstrato" (intrastratal karst; palmer & palmer, 1989; klimchouk, 1996a), nel quale la solubilizzazione del gesso avviene al di sotto di un'originaria coltre di copertura impermeabile. l'assetto geometrico del ctv e i rapporti con le limitrofe unità affioranti nel monferrato hanno permesso di individuare tre tipologie carsiche (fig. 16), distinte essenzialmente in base al grado di dissezione ed esposizione subaerea dell'intervallo gessoso e alla distribuzione tridimensionale e alla morfologia delle cavità di dissoluzione: 1) "carso inciso" (entrenched karst; klimchouk, 1996a), nel quale i blocchi selenitici del ctv sono profondamente dissecati e drenati dal reticolato idrografico. il gradiente idraulico che guida la circolazione delle acque sotterranee è più elevato rispetto agli adiacenti settori del sistema carsico. il reticolo di cavità ipogee si estende all'interno delle bancate gessose coinvolgendone l'intera potenza carsificabile (50÷60 m), ma con un'intensità dei fenomeni dissolutivi (in termini di sezione, profondità, frequenza e interconnessione dei condotti) decrescente verso il basso. lo spessore delle coltri di copertura, solitamente rappresentate dalla matrice del ctv e secondariamente da sedimenti pliocenici riferibili alle argille azzurre, è relativamente scarso (< 10 m) e tale da ricalcare l'andamento della morfologia epigea. nel carso inciso gli effetti del risentimento superficiale dei fenomeni di dissoluzione raggiungono la loro massima intensità, confermati dall'elevata frequenza delle doline di subsidenza e di collasso (fioraso & boano, 2002). questa tipologia carsica si manifesta prevalentemente nella fascia di distribuzione del ctv al contatto con i termini più vecchi della successione terziaria (es. marne di mincengo e di s. agata fossili) e in prossimità del settore assiale della dorsale collina di torino monferrato: esempi di carso inciso sono visibil i in corrispondenza delle cave di murisengo, della pirenta (fig. 2, sez. c-c') e di moncucco t.se (fig. 2, sez. d-d'). 2) "carso subgiacente" (subjacent karst; klimchouk, 1996a), nel quale i termini evaporitici sono solo parzialmente dissecati dall'idrografia di superficie. i sistemi carsici appaiono ben sviluppati unicamente al di sopra del livello di base locale, sebbene la dissoluzione possa intaccare, in qualche caso, anche i 470 g. fioraso et al. volumi gessosi a maggiore profondità. gli effetti della morfogenesi carsica raramente si trasmettono fino alla superficie, poiché attenuati dallo spessore delle coltri di copertura che può raggiungere valori di 20÷50 m. queste ultime sono costituite dalla matrice del ctv e dalle propaggini settentrionali della successione pliocenica rappresentata dalle argille azzurre e dalle sabbie di asti. questa tipologia carsica coinvolge buona parte della successione messiniana affiorante nel monferrato settentrionale: i settori nei quali meglio si esprimono le caratteristiche del carso subgiacente sono quelli di grana m.to (fig. 2, sez. a-a'), gessi di moncalvo (fig. 2, sez. b-b') e montiglio. 3) "carso profondo" (deep-seated karst; klimchouk, 1996a), ospitato nelle porzioni meno esumate del ctv e che pertanto risultano sigillate al di sotto della successione pliocenica monferrina. il carsismo in questo caso è privo di una qualsivoglia espressione morfologica, essendo confinato al di sotto di una potente coltre di copertura il cui spessore è il più delle volte superiore ai 40÷50 m. la presenza di fenomeni di dissoluzione profondi è rilevabile unicamente da elementi di tipo "indiretto". in occasione della realizzazione di un pozzo per acqua nei pressi di chieri (lungo il margine meridionale della collina di torino) è stata intercettata all'interno dell'intervallo gessoso una cavità a 80 m dal piano campagna, contenente acque fortemente arricchite in ioni solfato (sacco, 1925). analoga situazione è stata riscontrata nella porzione più meridionale della cava in sotterraneo di gessi di moncalvo, nella quale un sondaggio esplorativo, spinto alcune decine di metri al di sotto dell'attuale livello di coltivazione, ha intercettato abbondanti venute di acque fredde in pressione (~ 3 bar) fortemente arricchite in solfati: diversamente da tutte le manifestazioni carsiche fin qui analizzate, per le quali si è verificata una dissoluzione per descensum dei fluidi, nel secondo caso la mineralizzazione delle acque può essere attribuita all'effetto dissolutivo causato dalla risalita di fluidi profondi (dissoluzione per ascensum) in corrispondenza del prolungamento verso se delle strutture a carattere transpressivo che delimitano l'unità tettonica di ponzano-villadeati (dela pierre et al., 2003a). la presenza di circuiti idrogeologici relativamente complessi e profondi era già stata peraltro ipotizzata da bortolami et al. (2003) per spiegare la presenza, nel monferrato settentrionale, di alcune sorgenti fredde a chimismo solfato-calcico (es. pirenta di murisengo e fontana di calliano; fig. 1b): secondo questi autori, l'arricchimento in ioni solfato con valori prossimi al punto di saturazione sarebbe da ricercare nella risalita di acque lungo zone o superfici di faglia poste in prossimità o all'interno dei banchi gessosi messiniani. 8. meccanismi genetici ed evolutivi dei fenomeni carsici la diffusione delle cavità carsiche nei gessi del monferrato e della collina di torino può essere in primo luogo ricondotta all'elevata solubilità di queste rocce, che in acqua pura possono raggiungere concentrazioni piuttosto elevate e comprese tra 2,22 e 2,67 g l-1 in funzione della temperatura (jakucs, 1977). una conferma della rapidità evolutiva del carso gessoso nel btp è fornita da una serie di misurazioni effettuate da cucchi et al. (1998) per stimare la velocità della dissoluzione sviluppata sulla superficie di alcuni affioramenti selenitici nell'astigiano: i risultati dell'indagine, ottenuti con l'ausilio della metodologia mem (micro-erosion-meter method), hanno consentito di determinare un tasso di dissoluzione pari a 0,93 mm ogni 1000 mm di pioggia, a fronte di un valore medio riscontrato nei gessi messiniani italiani di 0,85 mm ogni 1000 mm di pioggia. significativo per apprezzare la velocità del fenomeno, 471manifestazioni carsiche nelle evaporiti ... fig. 16 schema di distribuzione dei fenomeni carsici nei livelli gessosi del complesso caotico di valle versa a sud della dorsale collina di torino monferrato (non in scala). la sezione corrisponde a un transetto idealmente orientato in direzione nord-sud. idealized cross-section (not in scale) traced along n-s transect with distribution of karst phenomena in the gypsum blocks of the valle versa chaotic complex, southern side of the collina di torino monferrato ridge. questo dato fa tuttavia riferimento a un carso esposto alla dissoluzione subaerea e consente unicamente di valutare l'ordine di grandezza della morfogenesi carsica: esso, infatti, è di difficile estrapolazione all'intero contesto messiniano del btp, caratterizzato quasi ovunque (ad eccezione dei pochi affioramenti subaerei prossimi alle aree di cava) da un carso coperto, nel quale il deflusso delle acque di infiltrazione è drasticamente ostacolato dalle coltri argillose. queste rallentano sensibilmente i fenomeni dissolutivi all'interfaccia gesso-coperture (macaluso et al., 2001), svolgendo un'azione protettiva nei confronti del gesso. infatti, grazie alla diminuzione della velocità di deflusso (funzione della granulometria, della composizione mineralogica e dello spessore delle coperture), le acque a contatto con i gessi raggiungono molto rapidamente la soglia di saturazione: in assenza di un rapido ricambio idrologico viene così a generarsi una sottile frangia ad elevata salinità che inibisce, o quanto meno rallenta, la dissoluzione. i bassi coefficienti di permeabilità che contraddistinguono l'intervallo messiniano (bortolami et al., 1989) sono tali da condizionare anche le modalità di assorbimento, da parte dei sistemi carsici, delle acque di precipitazione. le aree di affioramento del ctv e delle argille azzurre sono infatti prive di un reticolato idrografico ben definito, cui si accompagna l'assenza di inghiottitoi e punti di assorbimento: l'infiltrazione avviene pertanto in modo diffuso, con acque in grado di permeare solo gradualmente le coltri di copertura. queste ultime svolgono in tal senso la funzione di "filtro", rallentando la velocità di ingresso delle acque nel reticolato ipogeo: nelle cavità minerarie, infatti, si rileva uno sfasamento temporale dei picchi di acque edotte rispetto ai periodi di precipitazione, di entità variabile (al massimo qualche giorno), in funzione dello spessore e della natura dei terreni attraversati. solo una volta raggiunta l'interfaccia con il gesso, avvallamenti e depressioni epicarsiche possono costituire un richiamo per le acque di percolazione (con locali effetti di concentrazione e amplificazione della cinetica dissolutiva), che in tal modo hanno facile gioco nell'insinuarsi entro la rete di discontinuità, in primo luogo fratture e faglie, ben riconoscibili all'interno delle bancate evaporitiche. infatti, se i valori di permeabilità primaria dei gessi risultano in prima approssimazione trascurabili (le percentuali dei vuoti sono comprese tra il 4 e l'8% del volume gessoso, con punte massime del 15%; occella, 1958), ben diverso, e sicuramente predominante, è il ruolo svolto dalla fessurazione, grazie alla maglia di sistemi di fratture di estensione metricodecimetrica e di faglie di lunghezza da ettometrica a chilometrica (morelli, 2000; morelli et al., 2001). nel btp il gesso assume quindi le caratteristiche di un acquifero eterogeneo, anisotropo e discontinuo, nel quale le discontinuità costituiscono l'elemento primario nella veicolazione dell'acqua e conseguentemente nel controllo dei processi di dissoluzione (fig. 3). si citano ad esempio le cave di moncucco t.se e di grana m.to, nelle quali alcune cavità carsiche risultano impostate lungo faglie subverticali con direzione rispettivamente n100° e n150°. l'influenza delle strutture fragili risulta ancor più accentuato in presenza di fasce cataclastiche di spessore variabile da pochi millimetri a qualche metro, nelle quali il gesso si presenta minutamente brecciato. la diminuzione della taglia dei cristalli comporta una maggiore superficie specifica intergranulare esposta al contatto con l'acqua e un'accentuazione dei processi di solubilizzazione (cucchi et al., 1998; macaluso et al., 2001): secondo sonnenfeld (1984) la solubilità del gesso raggiunge i massimi valori per cristalli di taglia compresa tra 0,2 e 0,5 µm. ciò favorisce lo sviluppo di fenomeni di dissoluzione differenziali e l'impostazione di vie preferenziali per la veicolazione dei fluidi lungo i piani di faglia anziché all'interno delle bancate selenitiche. il procedere della speleogenesi determina quindi l'ampliamento delle discontinuità e il passaggio da originarie condizioni di flusso laminare lento a flussi turbolenti rapidi. si osserva infine un'accelerazione dei meccanismi dissolutivi in relazione ai minori tempi di contatto acqua-roccia e ai maggiori volumi di acqua sottosatura in transito nei condotti di neoformazione (james & lupton, 1978). questi ultimi divengono in tal modo gli elementi dominanti nella circolazione sotterranea, con rapido sviluppo di fenomeni di cattura delle acque a spese delle fratture e dei condotti idrologicamente meno efficienti (veni, 1987). la dissoluzione esercita nel tempo un controllo non solo sullo sviluppo e sulla configurazione del reticolato carsico (e in ultima analisi sulla macro-permeabilità dell'ammasso roccioso), ma anche sul chimismo e sul potenziale dissolutivo delle acque di percolazione. nell'epicarso la solubilizzazione dei cristalli selenitici risulta infatti molto intensa poiché svolta da fluidi meteorici ampiamente sottosaturi in solfati. l'aggressività dell'acqua diminuisce tuttavia in breve tempo e a breve distanza dal punto di ingresso nel sistema carsico, con conseguente arresto della dissoluzione una volta raggiunte concentrazioni in ioni so4 2prossime al punto di saturazione. nel monferrato questa ipotesi è confermata dalla diminuzione verso il basso del numero di pozzi e gallerie e del loro grado di interconnessione idraulica: all'elevato numero di forme di dissoluzione riscontrate nei primi 15÷20 m delle bancate di gesso si contrappone il ridotto numero di cavità intercettate nei livelli di coltivazione più profondi. anche gli interstrati marnoso-argillosi, generalmente di esigua potenza (20÷150 cm in media) ma caratterizzati da bassi valori di permeabilità, possono condizionare la circolazione delle acque, determinando la "compartimentazione" delle singole bancate evaporitiche: si tratta tuttavia di un controllo a valenza locale, in quanto i sistemi di faglie e-w, ne-sw e n-s che dislocano i blocchi gessosi garantiscono la presenza di soluzioni di continuità nell'ambito dei livelli euxinici. in sintesi l'efficienza dei meccanismi di dissoluzione risulta essere mediata: 1) dalle caratteristiche lito-strutturali della roccia (tessitura; composizione e purezza del gesso, che nel monferrato si aggira sul 95÷98%; presenza di interstrati argillosi, faglie, fratture e microfratture); 2) dalle caratteristiche idrauliche dei circuiti ipogei (sezione, numero e grado di gerarchizzazione e di interconnessione laterale dei condotti); 3) dalle condizioni di sottosaturazione in solfato di calcio dei fluidi. un fattore aggiuntivo che controlla i precedenti e che interviene sulle modalità di sviluppo del carso gessoso, è rappresentato dalla periodicità con cui opera la dissoluzione in relazione alla distribuzione temporale degli eventi piovosi: i volumi di acqua edotti dalle cave 472 g. fioraso et al. in sotterraneo di gessi di moncalvo e di murisengo, mediamente compresi tra i 3 e i 6 l/s, ricalcano l'andamento e l'entità delle precipitazioni. ciò da un lato conferma il carattere epidermico del fenomeno carsico nel btp, dall'altro evidenzia come la dissoluzione avvenga ad opera di acque di percolazione in ambienti ipogei sostanzialmente insaturi, che solo in occasione di prolungati eventi piovosi possono risultare temporaneamente saturi a seguito dell'innalzamento del livello di falda. tale ipotesi è supportata dalla presenza, all'interno di molte cavità, di abbondanti quantitativi di sedimenti argilloso-siltosi decantati e di strutture da disseccamento compatibili con rapide oscillazioni del livello piezometrico (cfr. § 5). inoltre, l'assenza di condotti carsici al di sotto degli attuali fondovalle (es. cave di gessi di moncalvo, murisengo e montiglio; fig. 2), indicherebbe un netto rallentamento della dissoluzione in prossimità della superficie della falda freatica, a sua volta in raccordo con il livello di base locale. infatti, sebbene le acque possano esercitare nella zona satura un attacco chimico sostanzialmente uniforme lungo tutte le discontinuità, le basse velocità di deflusso che contraddistinguono la zona satura rispetto a quella areata non consentono un rapido ricambio delle acque, inibendo l'azione dissolutiva che in tal modo non può svilupparsi nella sua completezza. 9. il fenomeno carsico nel quadro dell'evoluzione pliocenico-quaternaria del monferrato e della collina di torino la dissoluzione carsica può manifestarsi in due distinti momenti della storia evolutiva di una successione evaporitica: nel corso della precipitazione della successione ("carsismo singenetico"), per effetto di variazioni indotte nel contesto deposizionale da oscillazioni eustatiche del livello marino o da variazioni chimico-fisiche (es. diluizione) delle acque di precipitazione (warren, 1999); successivamente alla definitiva chiusura del ciclo evaporitico. nel secondo caso l'età, le modalità di sviluppo e le caratteristiche del carsismo differiscono in funzione del diverso contesto geodinamico e climatico nel quale la successione evaporitica viene di volta in volta a inserirsi nell'arco della propria evoluzione: variazioni nell'assetto stratigrafico, tettonico e morfologico possono infatti compromettere la funzionalità idrogeologica dei sistemi carsici già da tempo impostati, dando luogo a fenomeni di “fossil izzazione” dei circuiti ipogei (paleokarst; bosak et al., 1989), oppure consentire la ripresa di fenomeni dissolutivi da lungo tempo inattivi (exhumed karst; bosak et al., 1989). alla luce dei dati fin qui esposti, le manifestazioni carsiche individuate nella fascia del btp compresa tra il f. po (a nord) e il f. tanaro (a sud) mostrano di essersi sviluppate, sia pure con gradienti sensibilmente diversi, per effetto di una graduale esumazione della successione messiniana. pur in assenza di precisi elementi cronologici di riferimento, numerosi sono gli elementi di carattere stratigrafico, strutturale e morfologico che consentono di inquadrare temporalmente la formazione delle cavità e dei riempimenti, nonché di ricostruire l’evoluzione del complesso carsico del monferrato e della collina di torino. l'analisi, in termini puramente geometrici, dei rapporti intercorrenti fra l'orientazione delle bancate gessose e la vergenza delle forme dissolutive (condotti a sviluppo verticale e soprattutto cavità a "soffitto piatto", che possono in tal senso essere utilizzati come marker della deformazione) evidenzia un chiaro rapporto di sequenzialità del fenomeno carsico rispetto all'assetto stratigrafico locale del ctv. il divario appare meno marcato nei settori in cui minore è l'entità dell'esumazione del btp conseguente all'attivazione del thrust padano (es. grana m.to e molcalvo); risulta invece sensibilmente maggiore nei settori (es. montiglio e moncucco t.se) in cui la componente tettonica pliocenico-quaternaria si è sovrapposta ai fenomeni di collasso gravitativo e di caoticizzazione intra-messiniani che hanno coinvolto buona parte dell’intervallo evaporitico (dela pierre et al., 2002; 2003a) (fig. 16). lo smembramento di quest’ultimo ha inoltre comportato la frammentazione del complesso carsico monferrino in un mosaico di subsistemi, ciascuno dei quali confinato all'interno dei singoli blocchi gessosi (sia pure con estensione talvolta superiore al km2), che risultano idrogeologicamente sigillati dalla matrice argillosa del ctv. l’assenza di interconnessioni dirette tra i vari subsistemi rende i fenomeni dissolutivi all'interno di questi ultimi sostanzialmente indipendenti, pur in un comune e più ampio quadro evolutivo esteso a scala regionale. in questo contesto stratigrafico, l'assetto strutturale rilevabile all'interno delle bancate gessose ha svolto un condizionamento locale e sostanzialmente passivo nella veicolazione in profondità delle acque di dissoluzione (maggior permeabilità delle zone di faglia), nella localizzazione dei fenomeni dissolutivi (maggior solubilità del gesso nelle zone fratturate) e quindi nella circolazione idro-carsica. non sono invece emersi episodi di interferenza sin-morfogenetica tra le strutture tettoniche rilevate all’interno delle bancate gessose e i sistemi carsici, che in più punti vengono in diverso modo a intersecarsi. l’analisi della distribuzione tridimensionale dei fenomeni dissolutivi evidenzia un forte parallelismo tra l'evoluzione morfotettonica quaternaria del rilievo collinare monferrino e lo sviluppo del carsismo: salvo alcune eccezioni, legate alla locale presenza di circuiti profondi con risalita di acque lungo sistemi di faglia (cfr. murisengo e gessi di moncalvo), la dissoluzione è confinata al di sopra del livello di base locale, che costituisce l'elemento di raccordo di tutti i principali fondovalle alluvionali (fig. 16). il livello di base attuale e precedente assume quindi il ruolo di marker morfostratigrafico, che si esprime all’interno dei sistemi carsici con la presenza dei "soffitti di dissoluzione". il locale buon grado di correlazione altimetrica che queste forme mostrano talvolta con le superfici terrazzate distribuite a varie quote lungo le dorsali collinari del monferrato, avvalora l'ipotesi secondo cui tali cavità materializzerebbero delle paleo-superfici freatiche originariamente in raccordo con antichi livelli di base. i depositi fluviali conservati sulle superfici terrazzate più elevate mostrano complessivamente un discreto grado di evoluzione pedogenetica cui corrisponde un indice di colore pari a 5÷7,5 yr (alessio et al., 1982; carraro & valpreda, 1991; dela pierre et al., 2003a): ciò consente di stimare, quanto 473manifestazioni carsiche nelle evaporiti ... meno nei settori di maggior maturità dei sistemi carsici (entrenched karst) come quelli osservati a sud di murisengo e di moncucco t.se (cfr. fig. 2), un’età delle forme di dissoluzione sopravvissute al rimodellamento compresa tra la parte superiore del pleistocene medio e l’attuale. i sistemi idro-carsici del monferrato si sviluppano ed evolvono quindi in continua risposta alle variazioni indotte sull'assetto morfologico locale: all'esumazione del ctv si contrappone la migrazione relativa del fronte di dissoluzione, che viene in tal modo a collocarsi in posizione via via più prossima alla base dell'intervallo gessoso, meccanismo chiaramente rilevabile nei settori che ospitano esempi di subjacent karst (klimchouk, 1996a) (fig. 2, sez. a-a'; fig. 16). il rapporto di interrelazione dinamica tra esumazione tettonica e sviluppo del processo carsico è inoltre in accordo con le informazioni ricavate dall'analisi dei sedimenti di riempimento. due sono gli elementi che in tal senso confermano e affinano il quadro evolutivo proposto: a) le associazioni a microforaminiferi riscontrate nei riempimenti carsici campionati appaiono diversificate in funzione del diverso contesto stratigrafico locale e coprono un’intervallo temporale compreso tra il burdigaliano inferiore e il pliocene inferiore. appare quindi evidente come l’introduzione dei sedimenti nei circuiti ipogei sia iniziata a partire da un contesto tettono-stratigrafico sostanzialmente simile a quello attualmente osservabile e quindi successivo al picco deformativo che ha interessato la fascia settentrionale del btp. quest'ultimo coincide, a scala regionale, alla tettonica che ha determinato da un lato il sovrascorrimento della successione cenozoica del btp sull'avanfossa padana in relazione alla propagazione nord-vergente del thrust padano (pieri & groppi, 1981), dall'altro la risedimentazione gravitativa del ctv (dela pierre et al., 2003a). gli effetti della deformazione risultano particolarmente evidenti nell’area circostante la cava di moncucco t.se, nella quale le marne di s. agata fossili sono sovrapposte sui sedimenti del ctv (festa et al., 2002); b) le complesse alternanze di riempimenti carsici testimoniano il succedersi di episodi erosivo-deposizionali a carattere "ciclico": a momenti di totale occlusione dei condotti (accompagnati dalla formazione di sedimenti massivi o laminati legati a decantazione in acqua) si sono alternate improvvise disostruzioni delle cavità con smantellamento dei riempimenti sovrastanti e trasferimento degli stessi (cfr. “brecce di estrusione”) nelle parti più profonde dei sistemi carsici. questo meccanismo evolutivo ha imposto da un lato una periodica rielaborazione dei sedimenti di riempimento già presenti nei condotti ipogei, dall’altro il continuo apporto di nuovi sedimenti nelle parti più superficiali del sistema. le cavità carsiche del btp e i sedimenti in esse ospitati rappresentano in sintesi il prodotto di fenomeni di dissoluzione e sedimentazione polifasici e policronologici tuttora in evoluzione. nelle masse gessose del ctv sono registrati alcuni degli episodi carsogenetici che di volta in volta vi si sono impressi per effetto del graduale sollevamento ed esumazione dell’intervallo messiniano: quest'ultimo ha in tal modo acquisito un crescente grado di incarsimento in relazione all'approfondimento relativo del fronte di dissoluzione. la presenza di un reticolato ipogeo a prevalente sviluppo verticale è inoltre la conferma di una significativa mobilità verticale del rilievo ospitante il complesso carsico messiniano (nicod, 2002) e di una dissoluzione che ha operato in ambienti ipogei sostanzialmente insaturi (klimchouk, 1996b). nonostante ciò la presenza di livelli di base fossili (materializzati dalla combinazione di cavità a "soffitto piatto" e di lembi di depositi fluviali terrazzati) suggerisce che al graduale processo di esumazione si siano intervallate brevi fasi di relativa stabilità tettonica. simultaneamente, il rimodellamento del rilievo e la componente epigea della dissoluzione hanno comportato un sostanziale “ritocco” dell'originaria configurazione della superficie sommitale dei blocchi evaporitici (variabile in funzione del grado di esposizione subaerea del gesso) e la cancellazione delle tracce di fasi di dissoluzione pregresse. ringraziamenti gli autori desiderano ringraziare il dott. a. festa per aver messo a disposizione la sezione geologica della cava di moncucco t.se e la prof.sa d. violanti per aver effettuato l’esame del campione grn-1. si ringrazia inoltre il prof. f. carraro per la revisione critica del manoscritto e per i preziosi suggerimenti forniti. lavoro effettuato con fondi cnr – istituto di geoscienze e georisorse, sezione di torino. bibliografia alessio m., allegri l., ambrosetti p., bartolomei g., bella f., belluomini g., calderoni g., carraro f., charrier g., cortesi c., esu d., forno m.g., improta s., manfra l. & petrone v. (1982) il giacimento fossilifero pleistocenico superiore di moncucco torinese. geogr. fis. dinam. quat., 5, 219-239. arrington d.v. & lindquist r.c. (1987) thichly mantled karst of the interlachen, florida area. in: b.f. beck & w.l. wilson (eds.), karst hydrogeology: engineering and environmental applications. balkema, 467 pp. boano p. & forno m.g. (1999) la successione “villafranchiana” nell’area di castelnuovo don bosco (asti). il quaternario, 12 (2), 161-194. boni a. & casnedi r. (1970) note illustrative della carta geologica d’italia alla scala 1:100.000. fogli 69 e 70 "asti" e "alessandria". servizio geologico d'italia, 64 pp. bonsignore g., bortolami g.c., elter g., montrasio a., petrucci f., ragni u., sacchi r., sturani c. & zanella e. (1969) note illustrative della carta geologica d'italia alla scala 1:100.000. fogli 56 e 57 "torino" e "vercelli". servizio geologico d'italia, 96 pp. bortolami g., cavallero e., forno m.g. & mosso e. (1989) studio idrogeologico del bacino di asti. caratteristiche e potenzialità degli acquiferi. suolosottosuolo atti del congresso internazionale di geoingegneria. torino, 27-30 settembre 1989, 1, 431-440. 474 g. fioraso et al. bortolami g., masciocco l., de vecchi pellati r., ricci b. & saudino dughera b. (2003) le sorgenti della collina di torino e del monferrato. geam, 108, 77-82. bosak p., ford d.c., glazek j. & horacek i. (1989) paleokarst. developments in earth surface processes, 1. elsevier, 725 pp. bosticco l., bortolami g. & milano p.f. (1992) le coltivazioni di pietra da gesso nella zona di montiglio d'asti: indagine geologico-applicativa. geam, 76, 33-46. bosticco l. & marini p. (1995) i giacimenti di gesso del monferrato centrale (piemonte, ital ia) . 2° i.m.y.r.a.g., peveragno, 413-418. carraro f. (ed.) (1996) revisione del villafranchiano nell’area-tipo di villafranca d’asti. il quaternario, 9 (1), 5-120. carraro f. & valpreda e. (1991) the middle-upper quaternary of the asti basin. il quaternario, 4 (1), 151-172. castellarin a. (1982) tettonica sinsedimentaria e associazioni di facies carbonatiche. in: a. castellarin & g.b. vai (eds.), guida alla geologia del sudalpino centro-orientale. guide geologiche regionali, soc. geol. it., 23-40. castiglioni g.b. (1986) geomorfologia. utet, 436 pp. cita m.b. (1975) studi sul pliocene e sugli strati di passaggio dal miocene al pliocene. vii planktonic foraminiferal biozonation of the mediterranean pliocene deep sea record. riv. it. paleont. strat., 81, 527-544. clari p., fornara l., ricci b. & zuppi g.m. (1994) methane-derived carbonates and chemo-symbiotic communities of piedmont (miocene), northern italy: an update. geo-mar. lett., 14, 201-209. costa m. (2003) the buried, apenninic arcs of the po plain and northern adriatic sea (italy): a new model. boll. soc. geol. it., 122, 3-23. cucchi f., forti p. & finocchiaro f. (1998) gypsum degradation in italy with respect to climatic, textural and erosional conditions. in: j. james & p. forti (eds.), karst geomorphology. suppl. geogr. fis. dinam. quat., iii, t. 4, 41-49. dela pierre f., clari p., cavagna s. & bicchi e. (2002) the parona chaotic complex: a puzzling record of the messinian (late miocene) events in monferrato (nw italy). sedim. geol., 152, 289-311. dela pierre f., piana f., fioraso g., boano p., bicchi e., forno m.g., violanti d., clari p. & polino r. (2003a) note illustrative della carta geologica d'italia alla scala 1:50.000. foglio 157 "trino". apat, dipartimento difesa del suolo, 147 pp. dela pierre f., piana f., fioraso g., boano p., forno m.g., polino r. & clari p. (2003b) carta geologica d'italia alla scala 1:50.000. foglio 157 "trino". apat, dipartimento difesa del suolo. d'onofrio s., giannelli l., iaccarino s., morlotti e., romeo m., salvatorini g., sampò m. & sprovieri r. (1975) planktonic foraminifera of the upper miocene from some italian sections and the problem of the lower boundary of the messinian. boll. soc. paleont. it., 14, 177-196. eck w. & redfield r.c. (1965) engineering geology problems at sanford dam, texas. bull. ass. eng. geol., 3, 15-25. enel (1984) rapporto per la localizzazione di una centrale elettronucleare nella regione piemonte. area po1. rapporto n. 8401. festa a., bicchi e., boano p., cavagna s., clari p., dela pierre f., fioraso g., irace a. & piana p. (2002) tettonica intra-messiniana nella collina di torino: l’esempio della cava di gesso di moncucco torinese. società geologica italiana, 81° riunione estiva, 10-12 settembre 2002. riassunti, 161-162. fioraso g. & boano p. (2002) cavità di dissoluzione e fenomeni di sprofondamento nei gessi del monferrato settentrionale: meccanismi genetici ed effetti sulla stabilità dei versanti. geam, 107, 19-26. gelati r., rogledi s. & rossi m.e. (1987) significance of the messinian unconformity-bounded sequences in the apenninic margin of the padan foreland basin, northern italy. mem. soc. geol. it., 39, 319323. ghibaudo g., clari p. & perello m. (1985) litostratigrafia, sedimentologia ed evoluzione tettonico-sedimentaria dei depositi miocenici del margine sud-orientale del bacino terziario ligurepiemontese (valli borbera, scrivia e lemme). boll. soc. geol. it., 104, 349-397. hsü k.j., ryan w.b.f. & cita m.b. (1973) late miocene desiccation of the mediterranean. nature, 242, 240-244. irace a., clari p.a., dela pierre f., bicchi e., cavagna s. & festa a. (2002) la cava di gesso di moncucco torinese: un’area chiave per comprendere l’evoluzione messiniana della collina di torino bacino terziario piemontese. società geologica italiana, 81° riunione estiva, 10-12 settembre 2002. riassunti, 201-202. jakucs l. (1977) morphogenetics of karst regions. adam hilger, bristol, 284 pp. jennings j.n. (1985) karst geomorphology. blackwell, 293 pp. james a.n. & lupton a.r. (1978) gypsum and anhydrite in foundations of hydraulic structures. géotechnique, 28 (3), 249-272. johnson k.s. (2002) karst in evaporite rocks of the united states. carbonates & evaporites, 17 (2), 90-97. kempe s. (1972) cave genesis in gypsum with particular reference to underwater conditions. cave sci., j. brit. spel. ass., 49, 1-6. klimchouk a. (1996a) the typology of gypsum karst according to its geological and geomorphological evolution. in: a. klimchouk, d. lowe, a. cooper & u. sauro (eds.), gypsum karst of the world. international journal of speleology, 25 (3-4), 61-82. klimchouk a. (1996b) speleogenesis in gypsum. in: a. klimchouk, d. lowe, a. cooper & u. sauro (eds.), gypsum karst of the world. international journal of speleology, 25 (3-4), 49-60. klimchouk a. (1996c) hydrogeology of gypsum formations. in: a. klimchouk, d. lowe, a. cooper & u. sauro (eds.), gypsum karst of the world. international journal of speleology, 25 (3-4), 83-89. macaluso t., madonia g., palmieri a. & sauro u. (2001) atlante dei karren nelle evaporiti della sicilia. quaderni del museo geologico "g.g. gemellaro". dipartimento di geologia e geodesia, università di palermo, 5, 143 pp. 475manifestazioni carsiche nelle evaporiti ... marabini s. & vai g.b. (1989) geology of the monticino quarry, brisighella, italy. stratigraphic implications of its late messinian mammal fauna. boll. soc. pal. it., 28 (2-3), 369-382. marinelli o. (1917) fenomeni carsici nelle regioni gessose d'italia. memorie geografiche di giotto dainelli, 34, 263-416. morelli m. (2000) analisi sulla possibilità di integrazione dei dati telerilevati in studi geologico-strutturali: applicazione nel dominio del monferrato e delle langhe. tesi di dottorato inedita, univ. di torino, 168 pp. morelli m., piana f., polino r., pandiscia g., pirredda p. & milillo g. (2001) utilizzo dei dati lineamentari in studi geologico-strutturali: applicazione al monferrato. atti 5° conf. asita, rimini, 9-12 ottobre 2001, 2, 1079-1084. nicod j. (2002) karsts, palaeogeomorphology, palaeoenvironments. an overview of recent research on french karsts (1992-2001). géomorphologie, 3, 253-268. novaretti a., bicchi e., condello a., ferrero e., maia f., tonon m. & torta d. (1995) la successione oligo-miocenica del monferrato: sintesi dei dati biostratigrafici. in: r. polino & r. sacchi (eds.), atti conv. rapporti alpi-appennino. acc. naz. sci., sc. doc, 14, 39-60. occella e. (1958) caratteristiche di stabilità dei cantieri sotterranei nelle coltivazioni di "pietra da gesso" nell'astigiano. l'industria mineraria, 1958, 525534, 599-611. palmer m.v. & palmer a.n. (1989) paleokarst of the united states. in: p. bosak, d.c. ford, j. glazek & i. horacek (eds.), paleokarst, a systematic and regional review. developments in earth surface processes, 1, 725 pp. piana f. (2000) structural setting of western monferrato (alps-apennines junction zone, nw italy). tectonics, 19, 943-960. pieri m. & groppi g. (1981) subsurface geological structure of the po plain, italy. cnr progetto finalizzato geodinamica. sottoprogetto "modello strutturale". pubblicazione n. 414, 13 pp. polino r. (coord.) (2002) il sistema alpino-appenninico nel cenozoico. società geologica italiana. 81° riunione estiva. guida alle escursioni, 6-9 settembre 2002, 218 pp. rio d., sprovieri r. & di stefano e. (1994) the gelasian stage: a proposal of a new chronostratigraphic unit of the pliocene series. riv. it. paleont. strat., 100, 103-124. rouchy j.m., orszag-sperber f., blanc-valleron m.-m., pierre c., rivière m., combourieu-nebout n. & panaydes j. (2001) paleoenvironmental changes at the messinian-pliocene boundary in the eastern mediterranean (southern cyprus basins): significance of the messinian lago-mare. sedim. geol., 145, 93-117. roveri m., bassetti m.a. & ricci lucchi f. (2001) the mediterranean messinian salinity crisis: an apennine foredeep perspective. sedim. geol., 140, 201-214. roveri m., manzi v., ricci lucchi f. & rogledi s. (2003) sedimentary and tectonic evolution of the vena del gesso basin (northern apennines, italy): implications for the onset of the messinian salinità crisis. geol. soc. am. bull., 115 (4), 387-405. sacco f. (1889-1890) il bacino terziario e quaternario del piemonte. atti soc. it. sc. nat., 634 pp. sacco f. (1925) una zona gessosa presso chieri (torino). atti r. acc. sc. torino, 61, 123-129. salomon j.-n. (1999) le facteur temps dans la karstification. géomorphologie, 3, 195-214. sonnenfeld p. (1984) brines and evaporites. academic press, london, 613 pp. sturani c. (1973) a fossil eel (anguilla sp.) from the messinian of alba (tertiary piedmontese basin): paleoenvironmental and paleogeographic implications. in: c.w. drooger (ed.), messinian events in the mediterranean. k. ned. ak. wetensch, amsterdam, 243-255. tihansky a.b. (1999) sinkholes, west-central florida. a link between surface water and ground water. in: d. galloway, d.r. jones & s.e. ingebritsen (eds.), land subsidence in the united states. u.s. geological survey circular 1182, 177 pp. trebbi g. (1926) fenomeni carsici nei gessi bolognesi. la risorgente dell'"acqua fredda". giornale di geologia, serie 2, 1, 1-31. vai g. & ricci lucchi f. (1977) algal crusts, autocthonous and clastic gypsum in a cannibalistic evaporite basin: a case history from the messinian of northern apennines. sedimentology, 24, 211-244. veni g. (1987) fracture permeability: implications on cave and sinkhole development and their environmental assessment. in: b.f. beck & w.l. wilson (eds.), karst hydrogeology: engineering and environmental applications. balkema, 467 pp. warren j.k. (1999) evaporites. their evolution and economics. blackwell science, 438 pp. warren j.k., havholm k.g., rosen m.r. & parsley m.j. (1990) evolution of gypsum karst in the kirschberg evaporite member near fredericksburg, texas. journal of sedimentary petrology, 60, 5, 721-734. 476 ms. ricevuto l’8 settembre 2004 testo definitivo ricevuto il 23 novembre 2004 ms. received: september 8, 2004 final text received: november 23, 2004 g. fioraso et al. using the past to envisage a better future: the approach of a quaternary scientist. lucilla capotondi 1 , adele bertini 2 , emanuela falcucci 3 , stefano furlani 4 , giovanni monegato 5 , marco peresani 6 , maria rita palombo 7 , paola petrosino 8 , cesare ravazzi 9 , andrea zerboni 10 , ilaria mazzini 7 1 consiglio nazionale delle ricerche, ismar, bologna, italy. 2 dipartimento di scienze della terra, università di firenze, firenze, italy. 3 istituto nazionale di geofisica e vulcanologia (ingv), roma, italy. 4 dipartimento di matematica e geoscienze, università di trieste, trieste italy. 5 consiglio nazionale delle ricerche, igg, padova, italy. 6 dipartimento di studi umanistici, università di ferrara, ferrara, italy. 7 consiglio nazionale delle ricerche, igag, roma, italy. 8 dipartimento scienze della terra, dell’ambiente e delle risorse, università di napoli federico ii, napoli, italy. 9 consiglio nazionale delle ricerche, igag, milano, italy. 10 dipartimento di scienze della terra “ardito desio”, università degli studi di milano, milano, italy. corresponding author: l. capotondi <lucilla.capotondi@bo.ismar.cnr.it> abstract: the study of the past is of fundamental importance in understanding the processes that control the functioning of the earth system and the interaction between ecosystems, human society and natural variability. the quaternary scientist produces a variety of proxies derived from the investigation of natural, archaeological and historical records covering all time scales of the history of planet earth, including current dynamics, and with special focus to extend the calibrations to not instrumentally registered time spans. the covid-19 pandemic has highlighted not only the vulnerability of our world but it also has made plain for all to see the critical role of humans. on the other hand, it has produced the unexpected conditions for a large-scale experiment on the impact of sudden reduced human activities, pointing to the potential for recovery of the natural environment. in this review, we examine how data from the recent past can provide tools to understand the events taking place today and to forecast their developments in the future. keywords: quaternary, nature-human interaction, ecosystems, risk, interdisciplinary approach. available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 34 (2), 2021, 257-275 1. introduction during the last couple of centuries, human activities produced a wide range of environmental changes at unprecedented rates, including changes that are novel to earth history and that eventually became global in extent (waters et al., 2016). it has been stated in key streams of scientific literature that the increased anthropogenic activities (i.e., industrialization, nuclear fallout, microplastic contamination) in the last two decades polluted the atmosphere and hydrosphere, and impacted both biosphere and climate more than natural variability could (ipcc, 2018). yet, before the industrial revolution (or late anthropocene sensu waters et al., 2016; steffen et al., 2018) humans modified the biosphere influencing the climate at regional and global scale, causing changes in sediment fluxes and the ecosphere through fires, deforestation, irrigation, dams and farming (dearing, 2006; williams et al., 2014), thus supporting the parallel concept of palaeoanthropocene (foley et al., 2013). human beings affect nature in numerous ways, which induce changes in climate, ecosystems, and land vulnerability. the effects of the accelerating human impacts towards the end of the century (steffen et al., 2015) drove the earth out of the holocene epoch in which agriculture, sedentary communities, and eventually, socially and technologically complex human societies developed (steffen et al., 2018). human impact could irreversibly alter the earth system, as the current magnitude and rate of some human changes far exceeds the rates of change driven by geophysical or biosphere forces that have modified the earth system trajectory in the past, and even abrupt geophysical events do not approach current rates of human-driven change (steffen et al., 2018). for example, the paleocene-eocene thermal max https://doi.org/10.26382/amq.2021.16 258 capotondi l. et al. imum (petm) at 56 ma bp (before present), a warming event that reached 5-6°c and lasted about 100,000 years, accompanied by a rise in sea level and ocean acidification, drove the extinction of 35-50% of the deep marine benthic foraminifera and led to continent-scale changes in the distributions of terrestrial plants and animals (schneider von deimling et al., 2015). the warming was driven by a carbon release estimated to be ~1.1 gt c y-1 (ipcc, 2013). by comparison, the current human release of carbon to the atmosphere at ~10 gt c y1 is greater by nearly an order of magnitude (ipcc, 2013). cumulative human emissions of co2 from 1870 through 2017 have reached ~610 gt c (ipcc, 2013). recently the occurrence of the acute respiratory syndrome coronavirus 2 (sars-cov-2), linked to coronavirus disease 2019 (covid-19), has emphasized the need to enhance the mutually-affective connection between humans and nature (chin et al., 2020; yunus et al., 2020). in this contest, as quaternary scientists focused on the interaction between natural and past and present anthropogenic processes, we aim to discuss this topic within the framework of the italian territory, underlining the need of urgent actions in order to correctly plan a sustainable management of our territory. indeed, integrated quaternary research shows that deciphering the complex network of mechanisms driving past environmental change, and the resulting timelines of the dynamic history of the planet, is of crucial relevance to plan appropriate conservation actions and to collect insights into future scenarios for earth ecosystems. 2. the quaternary scientists of the 20 th century the growing identity of the scholar of the recent past the quaternary sciences grew up during the 20 th century, partly as a reaction to the splitting of natural sciences into their a-biological and biological components and the cultural divergence between the humanistic and the scientific approaches (izdebski et al., 2016). interdisciplinary studies are a pre-requisite for the study of the history of the environment and the functioning of ecosystems. in the meantime, a considerable degree of model flexibility is necessary when tackling the natural and cultural history, given that factors and processes vary in time and space. as a matter of fact, modern global change brings about phenomena unreported in the written recorded history, but visible inside the quaternary record (elias, 2007). multifactoriality, connectivity and unpredictable internal variability make history a difficult subject to be modelled and split up, even when humans are not involved. quaternary investigations involve researchers from different disciplines in order to integrate information from geology, archaeology, palaeoanthropology, botany, biology, zoology, climatology, chemistry, physics, etc.. the dialogue between different disciplines and the specific interdisciplinary, more than multidisciplinary, approach are the key for the study of the quaternary. quaternary studies are focused on the last periods in the stratigraphic scale, including current dynamics, thus also providing fundamental predictive tools to understand the present and suggest future scenarios. this allows for diversified viewpoints on natural phenomena and processes compared to colleagues from other geological disciplines or focused on older periods. additionally, the quaternary scientist faces large sets of problems related to the climate / environment / human nexus, developing a particular sensitivity towards natural processes and their repercussions on society, and vice versa (forman & stinchcomb, 2015). the research on this interval helps understanding how natural causes of (paleo)climate change strictly interact with human-driven modern climate change. on the other hand, the quaternary scientist establishes specific synergies with the biological sciences providing a historical long-term perspective (willis & birks, 2006; nogué et al., 2017) that sometimes lacks in the analysis of the living biota and could leverage the past to shape sustainable solutions to the current challenges (boivin & crowther, 2021). thus, a deep integration between biogeophysical earth system science and social sciences and humanities aims to put the dynamics of human societies in a global perspective. at present, scientists use models to understand how human activity is affecting the earth’s climate and to provide long-term projections of climate change under different anthropogenic emission scenarios . the models should represent the processes and interactions that drive the earth’s climate, including the atmosphere, oceans, land, and ice-covered regions of the planet. model agreement and confidence in projections depend on the used variables and spatial and temporal averaging. additionally, determining which of the multitude of models is most appropriate remains difficult and uncertainties in projected future climate conditions remain a challenge. forecasts need the observation of climate variability over long time intervals in order to define the different environmental scenarios subjected to changes and to know the subsequent response of the ecosystems. current ecosystem processes can often only be understood by looking back even longer. the observation of climate variability over long time intervals is therefore essential for scholars to record the different modes and timing scales of dynamic interactions. international efforts for uncovering hidden processes in ecological research "because they occur slowly" (magnuson, 1990) generated the long-term ecological research (lter) infrastructure: a network of terrestrial, freshwater, transitional and marine sites, now active at european and global scale (mirtl et al., 2021). lter represents one of the main novel approaches for analyzing how ecosystems change over time, and for describing and interpreting natural variability as opposed to ‘human-made’ variability. however, current lter research is carried out at decadal and secular scale (i.e., at the scale of human generations) and would benefit from longer time scales used by quaternary scientists through the use of multiple proxies. the quaternary approach helps deciphering the earth system dynamics that are controlled by nonlinear processes, interactions, and feedbacks. the twentieth century saw tremendous advances in understanding how the world works physically, chemically, biologically, 259 using the past to envisage a better future: the approach of a quaternary scientist and socially and in the applications of that knowledge to human endeavors. technology plays an important role in terms of both challenges and solutions, but it is worth of note that the complexity of nature is beyond our means of observation. both natural and anthropogenic factors intersect mutually and technological action that does not take into account the totality of factors leads to the degradation of ecosystems. yet the consequences of excess greenhouse gases in the atmosphere are already under our eyes, like climate change and ocean acidification. innovative approaches to solve the problems at hand in our complex human-environment interactions require closer collaboration between scientists and managers. interand transdisciplinary integration is continuously gaining importance in research programs and research infrastructure, development strategies (mirtl et al., 2021) and all these issues are addressed by quaternary investigations. 3. the quaternary history of environmenthuman interaction since its appearance on earth, human population grew and bio-culturally evolved up to colonize extreme landscapes. the huge number of traces unveiled from archaeo-anthropological and geoarchaeological records preserves an array of information that allows interpreting the interaction between climatic/environmental changes and humans since the earliest prehistory. natural archives (e.g. ice sheets, lake, peat, river and marine sediments, speleothems, palaeosoils, loess, tree rings) as much as anthropogenic stratigraphic sequences (open air, underwater and cave/rock shelter archaeological sites), bear palaeoenvironmental proxy data useful to evaluate the responses of ecological communities to (i) shifts from glacial to interglacial conditions or (ii) arid to humid environmental settings, (iii) rapid or gradual landscape changes, and (iv) climate-induced variations in the availability of water and food, which were the main factors driving human migrations (rotilio, 2015) alongside with other resources. for instance, such evidence includes different adaptation to new environmental settings (pini et al., 2020), resilience of human groups living in marginal environments, and eventually the collapse of societies or the relocation of entire population with the consequent abandonment of specific regions (brooks, 2006; butzer, 2012; nicoll & zerboni, 2020). despite this general trend, a growing number of palaeoenvironmental and archaeological studies distributed world-wide are shedding new light on the climate/ environment/human nexus, and especially are highlighting its complexity and non-linearity (boivin & crowther, 2021). if we consider early prehistory, the relationships between environmental modifications and human response seem to be generally unidirectional (environment  humankind). indeed, since the earlymiddle pleistocene transition, the increased magnitude of glacial cycles combined with unstable climatic conditions deeply influenced human population dynamics, punctuated by the effects of the “ebb and flow” process. contractions in population density up to the disappearance of any trace of human presence across vast areas of western eurasia were forced by the harshest climatic conditions with the maximum extension of the ice sheets. on the contrary, favorable conditions which occurred during the middle pleistocene interglacials promoted the growing of human population (hublin & roebroeks, 2009). however, palaeolithic huntergatherers expanded their ecological niches only from the late middle pleistocene onwards, as supported by a set of cultural improvements, consisting in the production of fire as energy budget (roebroeks & villa, 2011), in more effective technologies in stone knapping than in older times, innovation of domestic toolkits and hunting implements, and others. in the middle and late pleistocene eurasia, neanderthal native populations were bioculturally adapted to survive in an array of environments through the maintenance of equilibrate ecological relations (conard & richter, 2011). during the late pleistocene, their number contracted until their definitive disappearance around 40 ka cal bp in coincidence with the spread of homo sapiens (hublin, 2015). among several hypotheses proposed for identifying the forcing factors responsible of the neanderthal extinction (vaesen et al., 2021) disease burden, infections and stress on immune systems (greenbaum et al., 2019), and uvb radiations increase (channell & vigliotti, 2019) have been considered as the most likely. surprisingly, a recent study revealed how a major genetic risk factor for severe symptoms after sars-cov-2 infection is related to a neanderthal genomic segment that is carried by people in south asia and in europe (zeberg & pääbo, 2020). indeed, aside their biological and cultural worldwide affirmation and long-term mixing with native pleistocene people (haidinjak et al., 2021), upper palaeolithic anatomically modern humans experienced dramatic biological turnovers, with severe population bottlenecks across the late pleistocene as well, as attested from discontinuous archaeological record (djindjian et al., 1999; bocquet-appel et al., 2005; maier et al., 2016) and palaeogenetic studies (fu et al., 2016; posth et al., 2016; bortolini et al., 2021). the multiscale shifts that occurred from the last glacial maximum to the onset of the late glacial bølling interstadial (14.7 ka cal bp) are considered to be among the most important events. genetic discontinuities due to long-range migrations progressively contributed to shape the nature of the population dynamics that accompanied the modern human reexpansion into the boreal hemisphere (stoneking & krause, 2011) and the consequent exacerbation of most pleistocene megafauna from eurasia (see section 4). environmental changes associated to rapid climatic shifts are considered the leading factors in these extinction processes. indeed, since their first appearance in the boreal hemisphere, modern humans have also contributed to destabilize megafauna metapopulation structures and to the collapse of the related ecosystems (cooper et al., 2015). holocene records suggest that human transformation and landscape management increased since the neolithic revolution (hole, 1984; robb & van hove, 2003; zanchetta et al., 2013; cremaschi, 2014; zerboni & nicoll, 2019). human agency in shaping earth ecosystems played a long-term and increasing role (archaeoglobe project, 2019) and its effects influenced our planet at different resolution scales, from local to global. their influence on geomorphological processes included the enhancement of slow ongoing natural surface processes, the establishment of new geomorphological processes, and changes of the natural interactions in the critical zone (price et al., 2011) resulting in an intentional and un-intentional human agency on ecosystems. the transition from the subsistence of hunters-fishers-gatherers based on the collection of natural resources, to the economy of food production the so-called neolithic revolution (childe, 1936) and its consequent demographic increase (bocquet-appel, 2011) onset the positive feedback mechanism of a continuously increasing demand of resources. food production (either based upon cultivation or herding) increased since the neolithic revolution, which occurred at different times in each region of the planet. the common effect on the environment was the progressive modification of pristine ecosystems and the introduction of new ones (cremaschi, 2014; pini et al., 2017; archaeoglobe project, 2019; boivin & crowther, 2021). land use shifts and human agency like wood clearance and deforestation, timberline depression, grazing, farming, exploitation of water resources, and modification of natural hydrography (evans, 1998; sadori et al., 2011; cremaschi et al., 2016; henry et al., 2017; regattieri et al., 2019; mariani et al., 2020; morrison et al., 2021) had several effects on the landscape that included changes in soils, shallow aquifers, atmosphere composition, vegetation turnover and overall biodiversity (odgaard, 1999; perego, 2017; nogué et al., 2021). in the last two centuries, human forcing over the natural climate variability became evident, as a consequence of the abnormal increase of greenhouse gases in the atmosphere, which was promoted by anthropogenic emissions (crutzen, 2002). 4. the ecosystem answer to phanerozoic changes and the present-day global change: resilience and/or sixth extinction? the impact extent of anthropogenic factors on present-day ecosystem functioning and biodiversity integrity is a matter of an endless debate among scientists. biodiversity is declining globally at rates unprecedented in human history and the rate of species extinctions is accelerating. based on the recently published iucn report (iucn, 2020), about 67.64% of animal species disappeared from the wild during the last 70 years. available evidence points out the process acceleration as expected due to the continuous intensification of ecological stressors directly or indirectly linked to human activities. for instance, the monitoring of almost 21,000 populations of mammals, birds, amphibians, reptiles and fishes observed around the world between 1970 and 2016 shows a reduction of about 62%-73% (wwf, 2020). moreover, since the actual status of a number of species and subspecies is unknown and various species have been not formally identified/described, the magnitude of the contemporary biodiversity depletion may be underestimated (palombo, 2021). consequently, also considering the current number of critically endangered and vulnerable species (iucn, 2020), the idea of an ongoing sixth mass extinction became popular (barnosky et al., 2011; dirzo et al., 2014; payne et al., 2016; ceballos et al., 2017 and references therein). species extinction was a recurrent phenomenon during the 560 myr-long history of the phanerozoic, but the decline of biodiversity was generally outweighed by the appearance of new species, except for five geologically short times (end-ordovician ~440 ma, late devonian ~370-350 ma, end-permian ~250 ma, end-triassic ~220-200 ma, and end-cretaceous ~65 ma) when the earth lost more than three-quarters of its species (raup & sepkoski, 1986; jablonski, 1994; bambach, 2006; barnoski et al., 2011). although these “big-five” mass extinctions differed in magnitude, temporal extent, and complexity of dynamics, all were triggered by natural events sometimes synergically acting (e.g. sea-level and climate change, including global warming, ocean anoxia and acidification, volcanism, large meteorite impacts, and other abiotic changes in the biosphere) (palombo, 2021). their cascading effects protracted for hundreds of thousands to millions of years, followed by millions or tens of millions of years of biological recovery and biodiversity increase (erwin, 2001). climate forcing, acknowledged for most prequaternary extinction events, was the crucial factor driving flora and fauna turnovers during the pleistocene, inducing structural changes and latitudinal displacements in terrestrial biomes that greatly influenced flora and fauna dynamics. mammal species, for instance, mainly reacted to ecosystem disturbances by varying their geographic range. the pleistocene climatic oscillations (including glaciations, as well as periods of increasing aridity), triggered the secular, long-distance dispersal of several mammal species that entered and colonized new territory, upsetting the equilibrium of the pre-existing communities, leading to the extirpation/ replacement of stenoecious/less competitive species and stimulating new individual responses in other species. as a result, ecosystems significantly restructured during a long recovery period, though no real extinction events occurred (palombo, 2021). the late pleistocene/ early holocene megafauna extinction (lpme) was an exception, but it was an event of very small magnitude if compared to the palaeozoic and mesozoic mass extinction events. the lpme causal mechanisms are still debated. two main counterpoised hypotheses have been proposed that consider climatic changes and human hunting (overkilling) as the most likely drivers of lpme (monjeau et al., 2017). although prehistoric hunters likely increased the risk or accelerated the process of extinction for species already stressed by environmental changes, the available evidence indicates the latest pleistocene climatic changes as one of the dominant factors causing local extirpations, global extinctions and loss of biodiversity. the current global warming can be regarded as one, but possibly not the major factor causing the ongoing biodiversity depletion. the actual impact of climate warming on flora and fauna (particularly on the less ecologically flexible) and its related effects on other species and ecosystem functioning is quite difficult to determine (botkin et al., 2007). nonetheless, it could be argued capotondi l. et al. 260 5. natural hazards, risk and human presence (case studies in italy) natural hazards are among the "environmental problems" currently capturing so much public attention: they are naturally designed to modify ecosystems, but, in many cases, they reflect the impact of humans on their environments, and can largely affect human populations. the switch from hazard to risk occurs when a hazardous phenomenon turns into a disaster and becomes responsible for a great loss of assets and even for casualties (unisdr, 2009). correct practices of territorial planning and management are hence needed to reduce damaging effects. it is well known that under certain circumstances and conditions, the action of humans can actively determine or at least strongly contribute to determine hazard related to natural phenomena to which humans get exposed. these events are actually “human-made natural hazards”. in order to reduce vulnerability and achieve sustainable development targets, humans need to improve their knowledge of the environmental dynamics of the territory they live in and of the related hazards. the natural hazard risk atlas (2015) reports italy as the eighth country in the world, and the first in europe, in terms of exposure to natural hazards. in this contest, we focus here on the italian territory on view of its peculiar geological, morphological, and climatic characteristics (fig. 1). the position of the italian peninsula at the convergence of the eurasian and the african plate causes intense seismicity in most of the italian territory. additionally, geomorphological conditions along with land use changes and the frequent extreme rainfalls induced by climate change (fisher & knutti, 2016) make italy very prone to flooding and landslides. furthermore, wide sectors of the ca. 7500 kilometers long italian coastline is exposed to coastal flood hazard expected to become even more dangerous in the next decades due to sea level rise (bonaldo et al., 2019; antonioli et al., 2020). in 2014, a significant flood episode occurred in genova (liguria, n italy) strongly related to the dense urbanization of the terminal sections of streams and rivers. in general, streams and river beds constrained into small artificial channels or even entombed underground into undersized human-made tunnels (acquaotta et al., 2019) are the principal causes of flood disasters in the present climatic phase characterized by abrupt and extreme rainfall events (pfahl et al., 2017). during the mid-holocene, an increase of precipitations determined an increase of the rate of landslide events in europe (soldati et al., 2004; patton et al., 2019). similarly, the melting of permafrost determines an increase of local gravitational instabilities (matthews et al., 2018). nonetheless, human-made alteration of slope natural profiles, intense deforestation or even construction of infrastructures can make a slope gravitationally unstable and expose humans to risks caused by their own practices. a well-known case is represented by the vajont landslide, whose occurrence was favored by the realization of an artificial dam and the creation of an artificial hydrologic basin at the toe of mt. toc (genevois & tecca, 2013). that it might be more important than during most of the quaternary due to the magnification effect produced by anthropogenic ecological stressors (e.g., palombo, 2021). human activities prompted profound modifications of natural community structure, merging humanintroduced invasive exotic species (including pathogenic organisms) and native species, confining wild species within modified habitats, overharvesting terrestrial and marine resources, conditioning how mammals live and move through the human-altered landscape, causing the destruction and fragmentation of the world’s richest ecosystems, such as tropical forests, wetlands and savannahs. irreversibility on a human time scale (which is what we are interested in) likely has crucial effects on short-term environmental sustainability, with consequent impacts on human well-being because it affects the amount and availability of ecosystem resources and services that we require to survive (díaz et al., 2020). in addition, as stressed by ceballos et al. (2020) a further threat for human health and well-being would be the spread of viruses linked to wildlife trade (a concurrent cause of population and species extirpations and extinctions). a recent example is the current pandemic coronavirus disease (covid-19). human population is rapidly growing and human pressure on the biosphere and human-caused extinction is likely to accelerate. the species surviving in regions with high human impacts, under the action of anthropogenic ecological stressors and related feedbacks will likely further reduce their population number and size and ultimately disappear, triggering regional biodiversity collapses. in the near future, many severely endangered species will likely disappear all over the world as evidenced by data on the biodiversity intactness index trend in different regions, particularly influenced by the effects of land use and related pressures (scholes & biggs, 2005; newbold et al., 2016; wwf, 2020). deconstructing the complex network of mechanisms driving fauna and flora dynamics during the pleistocene, deciphering the relationship between extinction selectivity and extinction intensity, and understanding the past causal factors promoting ecosystem dynamics and the resilience of vulnerable ecosystems to quaternary climate changes is of crucial relevance for better understanding the actual extent of the role of human activity in amplifying the already significant negative effects produced by global warming. understanding the processes that regulated the impact of pleistocene climatic change on biodiversity dynamics, flora and fauna turnovers, species replacement and extirpation could provide interesting clues to predict the current effects of climate change on biodiversity loss (barnosky et al., 2011; willis & macdonald, 2011; palombo, 2021). a lesson from the recent past as the pleistocene fauna dynamics, highlights the relevance of landscape connectivity and the dangerous role of invasive species in preserving the vitality of wild population. it enables us to better understand the actual meaning of the present defaunation and plant biodiversity loss and to promote suitable conservation actions for the conservation of biodiversity in view of the ongoing climate warming and modifications of ecosystems. using the past to envisage a better future: the approach of a quaternary scientist 261 capotondi l. et al. fig. 1 maps of some of the geological “hazard” of the italian territory. in detail: a) map of landslide and hydraulic hazard (ispra, ispra rapporti 287/2018); b) map of seismic hazard (stucchi et al., 2004; ordinanza pcm n. 3519_2006); c) map of volcanic hazard of the campania multi-source area, for possible future explosive eruptions of campi flegrei, ischia island or somma-vesuvius (from lirer et al., 2010). 262 another vulnerability of the italian territory is represented by sinkhole risk. sinkholes commonly occur as features of karstic processes (dissolution of carbonate rocks) and their evolution into paroxysmal collapses of portions of ground surface. however, in anthropogenic environments and urbanized areas, the construction of underground infrastructures, lifelines or pipelines (such as aqueducts or sewer nets) can determine the conditions (i.e., underground erosion, water underexcavation) that can lead to human-induced local and abrupt subsidence, potentially resulting in the generation of sinkholes (gutiérrez et al., 2014). concerning the seismicity risk, although it is not possible to deterministically predict and prevent earthquake occurrences, environmental protection guidelines and correct practices could mitigate the risk associated to earthquakes (i.e., ground shaking, landslides, surface faulting). in the past decades an increasing number of proofs testifies to the occurrence of seismicity small-tomoderate magnitude seismic events in areas interested by human activities. such a phenomenon is referred to as induced and/or triggered seismicity, that means earthquakes induced or triggered by human exploitation of underground natural resources, fluid extraction or injection, wastewater disposal. one of the largest known seismic events of this kind is represented by the mw 5.8 earthquake occurred in 2016, in oklahoma (moschetti et al., 2019). wastewater injection into a high-rate well in the val d'agri oilfield (southern italy), the largest in onshore europe, has induced swarm microseismicity since the initiation of disposal (improta et al., 2017). it is worth of note that quaternary tectonic studies are essential for modern seismic hazard assessment because they represent an important tool to determine the seismic potential of seismogenic faults over much longer time periods than instrumental measurements, historical catalogues or onshore paleoseismic records (nelson et al., 2012). moreover, as a specific field of application, quaternary stratigraphy in the paleoseismological perspective of coastal, marine and lake environments has provided essential input to seismic and tsunami hazard assessments of coastal areas threatened by the effects of local and distant earthquakes (gràcia et al., 2013). the activity of the volcanoes that punctuate the italian territory (ischia, campi flegrei, sommavesuvius, etna, stromboli and vulcano at aeolian islands) represents an important source of risk, as well. nonetheless, in our country as in most of the mediterranean area the fertility of soils generally associated to the favorable geographic location (mostly along the coastline) of active volcanic areas encouraged human settlements over time (cottrell, 2015; freire et al., 2019). differently from earthquakes, which are instantaneous phenomena whose occurrence cannot be temporally predicted to date, volcanic eruptions have several precursory signals (principally seismic shakes, ground deformation, heat flux, compositional changes in volcanic gas and fluids) that, when correctly monitored, allow to forecast the occurrence of an eruption. thanks to the accurate and timely monitoring of these signals, the frequent volcanic crises linked to paroxysmal phases of open-conduit activity at etna and stromboli are successfully managed by the italian civil protection. in as much, very detailed pre-event evacuation plans have been prepared in conjunction with campania region authorities for the areas possibly endangered by future explosive eruptions of somma-vesuvius and campi flegrei. planning an evacuation is always a difficult task, mostly because of the uncertainty in the occurrence of an eruption, and it is even more difficult when evacuation plans involve several hundreds of thousands of people. people preparedness joined to a performing network of volcanic surveillance for the short-term forecast are essential to prevent disasters at active volcanoes. recent studies have improved volcanic risk management by advancing the basic scientific and technological skills employed in risk assessment and mitigation, producing updated computer models, vulnerability databases, and probabilistic risk assessment protocols (thierry et al., 2015). sea level has risen from the last glacial maximum (lgm) to nowadays and strongly modified the landscape, covering wide areas that are presently submerged, such as large part of the adriatic sea, or many submerged natural bridges, such as the one between calabria and sicily (antonioli et al., 2014). human constructions located along the coasts are exposed to flooding risk. nonetheless, for millennia humans have exploited coastal areas since they supply resources and provide a space for trading, as testified by hundreds of historical and archaeological structures at or below sea level. the recent increasing rate of sea level rise, if not slowed down or inverted, could cause an increase in the frequency of flooding events in many coastal regions interested by low-lying coasts and affect most of the human activities there. the fragility of the city of venice and its inestimable geological, cultural, historical, and artistic heritage represents a paradigm in the interaction between natural and human-induced high-water phenomena and the need to preserve the valuable city (zanchettin et al., 2021). the knowledge of the quoted hazardous phenomena (through the comprehension of the predisposing and triggering factors) and the awareness of the role of humans in potentially being a “risk” for themselves is the key to correctly plan the use of territories, in the view of a desirable sustainable development. the final aim of this correct behavior is leaving to natural phenomena the role of “potential hazards” and preventing them to become “risks”. thus, adequate preventive policies towards catastrophic events are strongly needed, along with a punctual regulation of the construction of buildings and infrastructures and in general of respect for the environment. 6. climate changes, human health and pandemic disease understanding the potential interaction between pandemic disease and climate is complex, as pointed out by many studies carried out in different areas of the world including the mediterranean region (mcmichael, 2012; luterbacher et al., 2020). throughout the late holocene, the atmospheric co2 concentration trapped in ice-cores documents an increasing trend (rubino et al., using the past to envisage a better future: the approach of a quaternary scientist 263 2019). some short-term drops (decades or more in duration) of this record, detected during the past two millennia are associated by some scientists with pandemic events responsible for high human mortality (ruddiman, 2007, 2010). based on this idea, the co2 decreases (corresponding to cool-to-cold events) detected at ca a.d. 540 and 1350, are related with the pandemics occurring during the roman period (the plague of justinian, in a.d. 540 to 542 and the “black death” between 1347 and 1352). another significant drop in co2 around 1500 to 1800 coincides with the catastrophic consequences of the arrival in america of europeans since 1492, inducing smallpox and other diseases in precolumbian populations. the consequences of these pandemics as reported by several historical sources are expressed, first of all, by massive mortality rates (crosby, 2003; mcmichael, 2012; koch et al., 2019). this in turn provoked widespread abandonment of rural villages and farms, reduced agricultural activity, and forests recovery (estimated in just 50 years). as a consequence, during pandemics the restored forests could have sequestered sufficient carbon to reduce concentra capotondi l. et al. fig. 2 an unprecedented water transparency venice (northern italy) was determined by the reduction of boat traffic and tourism (braga et al., 2020). the top image, captured 13 april 2020, shows a distinct lack of boat traffic compared to the image from 19 april 2019. (image credit: contains modified copernicus sentinel data (2019-20), processed by esa, cc by-sa 3.0 igo). 264 tions of co2 in the atmosphere as attested in palaeorecords. on the other hand, the end of the pandemic episodes promoted the reestablishment of the population in abandoned areas and the recovery of agriculture (deforestation, etc.) with the consequent increase of atmospheric co2 (and temperature) values. this hypothesis (ruddiman, 2007) clearly refers to global scale effects and require careful analyses of the geographical extent of pandemics and real mortality rates. this subject has been a matter of considerable debate in recent years (i.e., for the justinian plague, mordechai et al., 2019). the importance of the fossil record is also evident from recent discoveries that highlighted the role played by pathogens in the history of ancient empires and civilizations by isolating the genetic sequence of viruses and bacteria from human remains (wagner et al., 2014; rascovan et al., 2019; spyrou et al., 2019a, b). most of the pandemics cited above were caused by the bacterium yersina pestis, including the european neolithic catastrophe about 5,000 years ago, when early bronze age populations came down from the steppe to take the place of the neolithic farming communities of europe (close, 2021). instead, the cocoliztli pandemics that devastated the aztec empire were caused by bacteria belonging to the salmonella genus (close, 2021). the possibility that the geological record offers to identify and document (i) pandemic events over a long period of time, (ii) the source-areas of diffusion, and (iii) their effects on populations and environments, are especially relevant for the contribution to medical research, today much more prepared than in the past in the fight against pathogens. however, despite the remarkable progress of science in various fields, including the fast development of a vaccine for covid-19, the current environmental context, i.e., fast and easy global/ interplanetary travels (communications, interchanges, etc.) and climatic conditions marked by short-term drastic events, open up new challenges. among them, the different rate of forcing (fast worldwide spread of pandemics) vs (slower human) response is one of the main critical aspects. 7. the recent environmental context and conservation paleobiology the covid-19 pandemic has produced the unexpected conditions for a large-scale short-term experi using the past to envisage a better future: the approach of a quaternary scientist fig. 3 examples of waste accumulation at the mouth of the tiber river (latium, italy). top image the tiber river sediment plume in the tyrrhenian sea (image credit: contains modified copernicus sentinel data (2019-20), processed by esa, cc by-sa 3.0 igo). bottom left image: face mask waste along the beach of fiumicino (17 april 2021). bottom right image: plastic waste accumulation at fiumara grande (29 december 2020) (both images courtesy of martina pierdomenico). 265 ment on the impact of sudden reduced human mobility on land, at sea (rutz et al., 2020) and in the air. italy, being the first european country to perform a countrywide lockdown from march 11 th until may 4 th 2020, has experienced two months of unprecedented reduction of human disturbance in the industrial period. satellite images have shown a dramatic improvement of air quality (data from copernicus sentinel-5p about fluctuation of no2 concentrations across europe from 1-1-2020 until 11-2-2020, www.esa.int/esa_multimedia/ videos/2020/03/coronavi rus_ni t rogen_dioxide _emissions_drop_over_italy) and recent studies have shown a significant reduction of pm10, pm2.5, bc, benzene, co and nox in milan (northern italy) as an effect of the lockdown during last spring (collivignarelli et al., 2020). the exceptional conditions that emptied venice of millions of tourists and thousands of gondolas and vaporetti (fig. 2), together with natural seasonal factors, produced unprecedented low levels of suspended sediment and water transparency conditions (braga et al., 2020). limitations in human mobility have provided benefits to wildlife in general (manenti et al., 2020), although the records are always biased toward more appealing and visible taxa (batt, 2009) and trends of invertebrates and plants need to be investigated. a potential way to understand how ecological resilience is maintained even in the face of drastic changes is represented by the conservation biology merged with palaeobiology (fordham et al., 2020). this emerging discipline applies geohistorical records to the conservation and restoration of biodiversity and ecosystem services. since geologists can study times well beyond the limited frame of direct human observations, the use of geohistorical records could lead to a long-term perspective on ecosystems, species and communities of the recent past. a study about the opportunistic bivalve corbula gibba in the gulf of trieste, has demonstrated that the youngest fossil record (holocene-recent) could document the abrupt ecological changes affecting benthic communities during the 20 th century (fuksi et al., 2018). the c. gibba size variations (from 5 to 10-15 mm) were probably driven by a transition towards higher frequency of seasonal hypoxia (tomašových et al., 2020). the foraminifer and ostracod assemblages of the po river coastal plain were investigated with a conservation palaeobiology approach (barbieri et al., 2020) providing a high-resolution palaeoecological record under the influence of holocene sea-level rise, in analogy with the present-day global change. the recently discovered collapse of the native molluscan biodiversity along the israeli mediterranean shelf (albano et al., 2021) has been related both to the fast pace of warming of sea water and the lessepsian migration through the suez canal. with their palaeobiological conservation approach, albano et al. (2021) provided a snapshot of an irreversible change defined as “novel ecosystem”. it is not possible to estimate the extent of the impact of covid-19 as there is no robust data on hand for the analysis of trends in sedimentation rates, heavy metal contamination, algal blooming, invertebrate benthic community changes. although pollution in general is decreased, the worldwide resurgence in the use of disposable personal protective equipment (ppe) and of disposable items in restaurants and other businesses to operate safely is a new potential source for microplastic pollution (espejo et al., 2020). for italy alone, a country with 60.4 million inhabitants, ppe needs for the population during deconfinement has been estimated as 1 billion face masks and 0.5 billion gloves per month. this sums up to the average amount of plastic waste released in the environment that normally accumulates on land, in the lakes, rivers and along the coasts of italy (fig. 3). on the contrary, household waste production has generally decreased during the pandemic, falling by 28% in milan (prata et al., 2020). we could be relatively certain that the covid-19 pandemic will leave a clear signal in the sediments. not only such a signal will be temporally well defined and globally distributed but could be an excellent test to examine the response mechanisms of living populations to different stress factors. 8. concluding remarks: reconsidering the relationships between humans and ecosystems on the italian territory it is evident that we are in a strongly transient phase in which human societies, the biosphere and the climate system are all changing at very rapid rates and our usual activities are necessarily modified. the diffusion of the covid-19 virus highlighted the weakness of our actions towards the protection of our planet as well as our dysfunctional relationship with nature. during the global 2020 lockdown, when population was confined home for a long period of time ranging from a few weeks up to a few months and with nearly the total absence of activities influencing the earth atmosphere and oceans, the answer of nature gave us a great lesson about its resilience and capacity for rapid recovery. the reduction of air pollutants and heavy metals, the unusual transparency of waters in lagoonal areas such as venice, the occurrence of animals in the cities are among the evidence observed by everyone. these observations highlight the importance of longterm ecological observation and monitoring in order to discriminate how ecosystems change and adapt in response to climate variability and human activity (fig. 4). it is urgent to reconfigure our view about nature (fig. 4). we feel that new prospects on human adaptation should respect the independence of natural dynamics, thus developing nature-based solutions through investments in green growth (mandle et al., 2019). the current crisis generated by the health state and the consequent restrictions offers the opportunity for novel insight and makes imperative to adopt sustainable options by reconciling the needs of citizens with the characteristics and vulnerabilities of the territory. even if the peculiarities of the italian territory are particularly prone in originating hazards and risks, several anthropogenic factors have contributed in a decisive way to trigger or intensify their consequences. recently, urbanization, settlement in hazardous areas, and unsustainable land use have put more people and wealth in danger. thus, it is necessary to reconsider urban expansion and space planning. investments in monitoring and surveillance systems are essential for tracking changes in the environment, particularly those factors that affect human capotondi l. et al. 266 using the past to envisage a better future: the approach of a quaternary scientist fig. 4 changing views about nature over the past 50 years reconfigured the human-nature relationship over time, resulting in four main frameworks (1) nature for itself; (2) nature despite people; (3) nature for people; (4) people and nature (mace et al., 2014; folke et al., 2021). perception of these concepts needs a solid scientific basis to which all geoenvironmental disciplines are urged to contribute. we declined frameworks (1) to (4) in a fully quaternary narrative, focusing on the role of quaternary science in terms of perspectives and challenges. we look forward after the narrow perspective of a single human generation (see steffen et al., 2018); we feel that new perspectives to human adaptation should respect the independence of nature dynamics, thus developing nature-based solutions investing in green growth (mandle et al., 2019) (4). image step 1image courtesy of m. lopez-herrera via the olduvai paleoanthropology and paleoecology project and enrique baquedan from www.newhistorian.com/2016/03/13/scientists-reconstruct-habitat-early-human-ancestors/ image step 2 disastro del vajont, 1963. fonte: ansa from www.mountainblog.it/redazionale/la-tragedia-del-vajont-streaming-nondimenticare/. image step 3 volcanic risk map for ischia island active volcanic area from lirer et al. (2010). image step 4 green growth index 2020: measuring performance in achieving sdg targets from gggi.org/report/green-growth-index-2020-measuring-performance-inachieving-sdg-targets/ 267 health. additionally, changes in frequency and intensity of climate anomalies in the recent past contributed to increase the occurrence rate and magnitude of natural disasters. this highlights the importance of analysing the historical rainfall series and generating spatially precise climate simulations in order to develop adequate adaptation strategies and plans (spano et al., 2020). the interaction between scientific research and technology helps in proposing suitable and sustainable interventions. for example, to contrast the negative effects of sea level rise, river flooding, and landslides, it is mandatory to reduce built areas, which cause soil loss and reduce water infiltration leading to soil erosion and floods. a darker scenario at a global scale emerges from the latest reports from the ersl global monitoring laboratory of the noaa, which monitors trends in atmospheric carbon dioxide. “can we see a change in the co2 record bec a u s e o f c o v i d 1 9 ? ” (gml.noaa.gov/ccgg/covid2.html) (browsed september, 2 nd , 2021). it seems that co2 keeps increasing at the same rate recorded in previous years. therefore, we are urged to make investments in renewable energy and in natural carbon longterm storage such as proforestation. proforestation is the practice of purposefully growing an existing forest intact toward its full ecological potential and is a naturebased solution where existing forests are protected as intact ecosystems to foster continuous growth for maximal carbon storage and ecological and structural complexity. this is a powerful climate solution which may be adapted at regional scale (leverett et al., 2021; mack et al. 2021) and may be managed regionally by the collaboration of quaternary palaeoecologists, forestry experts, and decision-makers, by estimating the biomass potential of pristine forests and address the future forest succession (leverett et al., 2021). proforestation is much more effective than planting new tree individuals (zastrtow, 2019). it could reconcile nature-based biological carbon sequestration and an array of ecosystem services such as biodiversity enhancement, water and air quality, flood and erosion control, public health benefits, low impact recreation, and scenic beauty. but actions like proforestation must become a global effort, much more aggressive than the impact that the pandemic forced over the reduction to global co2 emissions. the terminology recently used to distinguish ecosystems based on the degree of human interaction (“novel ecosystems,” “impacted ecosystems,” or “designed ecosystems”) suggests that societies would most efficiently invest time, effort, and financial resources if they focus on managing novel ecosystems for the ecosystem services that they can provide, rather than attempting to restore them to their previous states (morse et al., 2014). viewing “novel ecosystems” in this way and recognizing the trade-offs between their positive and negative aspects will allow managers the pragmatic flexibility needed to make informed and sensible decisions concerning resource use and ecosystem maintenance (morse et al., 2014). however, addressing these questions requires to plan adequate monitoring programs for the data collection and an accurate knowledge of the dynamics, structure, and longevity of past biodiversity to fully depict the influence of human impact and ecosystem response over time. in conclusion, we need scientists with different expertise such as naturalists, biologists, oceanographers, limnologists, geologists, climatologists, historical ecologists, archaeologists, soil scientists, possibly interacting with economists and local stakeholders endowed with specific skills to evaluate environmental sustainability and to propose effective and long-term solutions to address global environmental crises and human responses (fig. 5). we need to face a deep change in perspective: from the post-event emergency response and assistance to risk forecast and prevention. the quaternary record allows our knowledge to capotondi l. et al. fig. 5 world cloud of the main conceptual terms used in the text. it highlights the fact that the global environmental crises lift the curtain on the intrinsic relationship between humans, climate and nature. 268 https://gml.noaa.gov/ccgg/covid2.html stretch beyond the present and to collect insights into the earth ecosystems future scenarios through lessons from the past. although not all the solutions pertain to the expertise pertaining of quaternary scientists, knowing quaternary helps understanding causes and dynamic processes to propose suitable and sustainable interventions. author contributions l.c. conceived of the presented idea and took the lead in writing the manuscript with input from all authors. c.r. focused on paragraph 2 and 8, m.p. and a.z. on paragraph 3, mr. p. on paragraph 4; e.f., pp. and s.f. on paragraph 5, a.b. on paragraph 6, and i.m. on paragraph 7. g.m. provided critical feedback. l.c. c.r., p.p. and i.m. drew the figures. all authors commented on the manuscript. acknowledgements we are grateful to biagio giaccio, guido s. mariani and two anonymous reviewers for their comments and constructive suggestions that improved the final version of the manuscript. many thanks to martina pierdomenico and federica braga for their graphical support. references albano p.g., steger j., bošnjak m., dunne b., guifarro z., turapova e., hua q., kaufman d.s., rilovand g., zuschin m. (2021) native biodiversity collapse in the eastern mediterranean. proceedings of the royal society, b288:20202469. doi: 10.1098/rspb.2020.2469 antonioli f., lo presti v., gasparo morticelli m., bonfiglio l., mannino m.a., palombo m.r., sannino g., ferranti l., furlani s., lambeck k., canese s., catalano r., chiocci f.l., mangano g., scicchitano g., tonielli r. (2014) timing of the emergence of the europe-sicily bridge (40-17 cal ka bp) and its implications for the spread of modern humans. in: geology and archaeology: submerged landscapes of the continental shelf (ed. by harff j., bailey g., luth f.). geological society of london, special publications, 411, 111144. antonioli f., de falco g., lo presti v., moretti l., scardino g., anzidei m., bonaldo d., carniel s., leoni g., furlani s., marsico a., petitta m., randazzo g., scicchitano g., mastronuzzi g. (2020) relative sea level rise and potential submersion risk for 2100 on 16 coastal plains of the mediterranean sea. water, 12, 2173. acquaotta f., faccini f., fratianni s., paliaga g., sacchini a., vilímek v.i. (2019) increased flash flooding in genoa metropolitan area: a combination of climate changes and soil consumption ? meteorology atmospheric physics, 131, 10991110. doi: 10.1007/s00703-018-0623-4 archaeoglobe project (2019) archaeological assessment reveals earth’s early transformation through land use. science, 365, 897-902. bambach r.k. (2006) phanerozoic biodiversity mass extinctions. annual review of earth and planetary sciences, 34, 127-155. barbieri g., rossi v., ghosh a., vaiani s.c. (2020) conservation paleobiology as a tool to define reference conditions in naturally stressed transitional settings: micropaleontological insights from the holocene of the po coastal plain (italy). water, 12, 3420. doi: 10.3390/w12123420 barnosky a.d., matzke n., tomiya s., wogan g.o., swartz b., quental t.b., marshall c., mcguire j.l., lindsey e.l., maguire k.c., mersey b., ferrer e.a. (2011) has the earth’s sixth mass extinction already arrived? nature, 471(7336), 51-57. batt s. (2009) human attitudes towards animals in relation to species similarity to humans: a multivariate approach. bioscience horizons, 2, 180-190. bocquet-appel j.p., demars p.y., noiret l., dobrowsky d. (2005) estimates of upper palaeolithic metapopulation size in europe from archaeological data. journal of archaeological science, 32, 16561668. bocquet-appel j.p. (2011) when the world's population took off: the springboard of the neolithic demographic transition. science, 333, 560-561. boivin n., crowther a. (2021) mobilizing the past to shape a better anthropocene. nature ecology and evolution, 5, 273-284. bonaldo d., antonioli f., archetti r., bezzi a., coreggiari a., davolio s., de falco g., fantini m., fontolan g., furlani s., gaeta m.g., leoni g., lo presti v., mastronuzzi g.a., pillon s., stocchi p., samaras a.g., scicchitano g., carniel s. (2019) integrating multidisciplinary instruments for assessing coastal vulnerability to erosion and sea level rise: lessons and challenges from the adriatic sea, italy. journal of coastal conservation, 23(1), 19-31. bortolini e., pagani l., oxilia g., posth c., fontana f., badino f., saupe t., montinaro f., margaritora d., romandini m., lugli f., papini a., boggioni m., perrini n., oxilia a., aiese cigliano r., barcelona r., visentin, d., fasser n., arrighi s., figus c., marciani g., silvestrini s. (2021) early alpine occupation backdates westward human migration in late glacial europe. current biology, 31, 1-10. botkin d.b., saxe h., araujo m.b., betts r., bradshaw r.h., cedhagen t., chesson p., dawson t.p., etterson j.r., faith d.p., ferrier s., guisan a., skjoldborg hansen a., hilbeet d.w., loehle c., margules c., new m., sobel m.j., stockell d.r.b. (2007) forecasting the effects of global warming on biodiversity. bioscience, 57(3), 227-236. braga f., scarpa g.m., brando v.e., manfè g., zaggia l. (2020) covid-19 lockdown measures reveal human impact on water transparency in the venice lagoon. science of the total environment, 736, 139612. doi: 10.1016/j.scitotenv.2020.139612 brooks n. (2006) cultural responses to aridity and increased social complexity in the middle holocene. quaternary international, 151, 29-49. butzer k. (2012) collapse, environment and society. using the past to envisage a better future: the approach of a quaternary scientist 269 https://doi.org/10.1007/s00703-018-0623-4 pnas proceedings of the national academy of sciences united states of america, 109, 36323639. ceballos g., ehrlich p.r., dirzo r. (2017) biological annihilation via the ongoing sixth mass extinction signaled by vertebrate population losses and declines. pnas proceedings of the national academy of sciences united states of america, 114(30), e6089-e6096. ceballos g., ehrlich p.r., raven p.h. (2020) vertebrates on the brink as indicators of biological annihilation and the sixth mass extinction. pnas proceedings of the national academy of sciences united states of america, 117(24), 13596-13602. channell j.e.t., vigliotti l. (2019) the role of geomagnetic field intensity in late quaternary evolution of humans and large mammals. reviwes in geophysics, 57(3), 709-738. doi:10.1029/2018rg000629 childe g. (1936) man makes himself. oxford university press, oxford, pp. chin a., cui x., gillson l., nelson d., taylor m.p., vanacker v., wang e. (2020) anthropocene in an age of pandemics. anthropocene, 30, 100247. close j. (2021) le epidemie che hanno cambiato il mondo. le scienze, 629, 51-55. collivignarelli m.c., abbà a., bertanza g., pedrazzani r., ricciardi p., carnevale miino m. (2020) lockdown for covid-2019 in milan: what are the effects on air quality? science of the total environment, 732, 139280. doi: 10.1016/j.scitotenv.2020.139280 conard n., richter j. (2011) neanderthal lifeways, subsistence and technology. one hundred fifty years of neanderthal study. vertebrate paleobiology and paleoanthropology series, springer, dordrecht, 287 pp. cooper a., turney c., hughen k.a., brook b.w., mcdonald h.g., bradshaw c.j.a. (2015) abrupt warming events drove late pleistocene holarctic megafaunal turnover. science, 349, 6248. cottrell e. (2015) global distribution of active volcanoes. in: volcanic hazards risks disaster (ed. by papale p., shroder j.f.). elsevier, amsterdam, 116. cremaschi m. (2014) when did the anthropocene begin? a geoarchaeological approach to deciphering the consequences of human activity in preprotohistoric times: selected cases from the po plain (northern italy). rendiconti lincei scienze fisiche e naturali, 25, 101-112. cremaschi m., mercuri a.m., torri p., florenzano a., pizzi c., marchesini m., zerboni a. (2016) climate change versus land management in the po plain (northern italy) during the bronze age: new insights from the vp/vg sequence of the terramara santa rosa di poviglio. quaternary science reviews, 136, 153-172. crosby a. w. (2003) the columbian exchange: biological and cultural consequences of 1492 (vol. 2). greenwood publishing group, pp. crutzen p.j. (2002) geology of mankind. nature, 415, 23. dearing j.a. (2006) climate-human-environment interactions: resolving our past. climate of the past, 2, 187-203. díaz s., settele j., brondízio e., ngo h., guèze m., agard j., arneth a., balvanera p., brauman k., butchart s., chan k., garibaldi l., ichii k., liu j., subrmanian s., midgley g., miloslavich p., molnár z., obura d., pfaff a., polasky s., purvis a., razzaque j., reyers b., chowdhury r., shin y., visseren-hamakers i., wilis k., zayas c. (2020) summary for policymakers of the global assessment report on biodiversity and ecosystem services of the intergovernmental science-policy platform on biodiversity and ecosystem services. www.ipbes.net/sites/default/fi les/downloads/ spm_unedited_advance_for_posting_htn.pdf dirzo r., young h.s., galetti m., ceballos g., isaac n.j., collen b. (2014) defaunation in the anthropocene. science, 345(6195), 401-406. doi: 10.1126/science.1251817 djindjian f., kozłowski j.k., otte m. (1999) le paléolithique supérieur en europe. colin ed., paris, 473 pp. elias s.a. (2007) societal relevance of quaternary research. in: encyclopedia of quaternary science, vol. 1 (ed. by elias s.a.). elsevier, amsterdam, 1-10. erwin d.h. (2001) lessons from the past: biotic recoveries from mass extinctions. pnas proceedings of the national academy of sciences, 98, 13991403. espejo w., celis j.e., chiang g., bahamonde p. (2020) environment and covid-19: pollutants, impacts, dissemination, management and recommendations for facing future epidemic threats. science of the total environment, 747, 141314. evans r. (1998) the erosional impacts of grazing animals. progress in physical geography, 22, 251268. fisher e.m., knutti r. (2016) observed heavy precipitation increase confirms theory and early models. nature climate science, 6, 986-991. foley s.f., gronenborn d., andreae m.o., kadereit j.w., esper j., scholz d., pöschl u., jacob d.e., schöne b.r., schreg r., vött a., jordan d., lelieveld j., weller c.g., altai k.w., gaudzinskiwindheuser s., christian bruhn k., tost h., sirocko f., crutzen p.j. (2013) the palaeoanthropocene the beginnings of anthropogenic environmental change. anthropocene, 3, 83-88. folke carl c., polasky s., rockström j., galaz v., westley f., lamont m., scheffer m., osterblom h., carpenter s.r., chapin iii f.s., seto k.c., weber e.u., crona b.i., daily g.c., dasgupta p., gaffney o., gordon l.j., hoff h., levin s.a., lubchenco j., steffen w., walker b.h. (2021) our future in the anthropocene biosphere. ambio, 50, 834-869. fordham d.a., jackson s.t., brown s.c., huntley b., brook b.w., dahl-jensen d., gilbert m.t.p., ottobliesner b.l., svensson a., theodoridis s., wilmshurst j.m., buettel j.c., canteri e., mcdowell m., orlando l., pilowsky j., rahbek c., nogues-bravo d. (2020) using paleo-archives to capotondi l. et al. 270 https://doi.org/10.1016/j.scitotenv.2020.139280 safeguard biodiversity under climate change. science, 369, eabc5654. doi: 10.1126/science.abc5654 forman s., stinchcomb g. (2015) views on grand research challenges for quaternary geology, geomorphology and environments. frontiers in earth science, 3, 47. freire s., florczyk a.j., pesaresi m., sliuzas r. (2019) an improved global analysis of population distribution in proximity to active volcanoes, 19752015. isprs international journal of geoinformation, 8(8), 341. doi: 10.3390/ijgi8080341 fu q., posth c., hajdinjak m., petr m., mallick s., fernandes d., furtwängler a., haak w., meyer m., mittnik a., nickel b., peltzer a., rohland n., slon v., lazaridis i., lipson m., schiffels s., skoglund p., gély b., benazzi s., gonzales morales m.r., peresani m., straus l.g., caramelli d., lari m., ronchitelli a., valentin f., constantin s., coppola d., grigourescu d., neugebauermaresch c., thevenet c., wehrberger k., crevecoeur i., rougier h., semal p., cupillard ch., bocherens h., mannino m., conard n.j., harvati k., moiseyev v., drucker d.g., svoboda j., pinhasi r., kelso j., patterson n., krause j., pääbo s., reich d. (2016) the genetic history of ice age europe. nature, 534, 200-205. doi: 10.1038/nature17993 fuksi t., tomašových a., gallmetzer i., haselmair a., zuschin m. (2018) 20th century increase in body size of a hypoxia-tolerant bivalve documented by sediment cores from the northern adriatic sea (gulf of trieste). marine pollution bulletin 135, 361 -375. doi: 10.1016/j.marpolbul.2018.07.004. genevois r., tecca p.r. (2013) the vajont landslide: state of the art. italian journal of engineering geology and environment book series (6), 1-39. gràcia e., lamarche g., nelson h., pantosti d. (2013) preface: marine and lake paleoseismology. natural hazards and earth system sciences, 13, 34693478. doi: 0.5194/nhess-13-3469-2013 greenbaum g., getz w.m., rosenberg n.a., feldman m.w., hovers e., kolodny o. (2019) disease transmission and introgression can explain the long-lasting contact zone of modern humans and neanderthals. nature communications, 10 (1), 112. doi: 10.1038/s41467-019-12862-7 gutiérrez f., parise m., de waele j., jourde, h. (2014) a review on natural and human-induced geohazards and impacts in karst. earth-science reviews, 138, 61-88. doi: 10.1016/j.earscirev.2014.08.002 hajdinjak m., mafessoni f., skov l., vernot b., hübner a., fu q., essel e., nagel s., nickel b., richter j., moldovan o.t., constantin s., endarova e., zahariev n., spasov r., welker f., smith g.m., sinet-mathiot v., paskulin l., fewlass h., talamo s., rezek z., sirakova s., sirakov n., mcpherron s.p., tsanova t., hublin j.-j., peter b.m., meyer m., skoglund p., kelso j., pääbo s. (2021) initial upper palaeolithic humans in europe had recent neanderthal ancestry. nature, 592, 253-257. doi: 10.1038/s41586-021-03335-3 henry d.o., cordova c.e., portillo m., albert r.-m., dewitt r., emery-barbier a. (2017) blame it on the goats? desertification in the near east during the holocene. the holocene, 27, 625-637. hole f. (1984) a reassessment of the neolithic revolution. paléorient, 10(2), 49-60. hublin j.j. (2015) the modern human colonization of western eurasia: when and where? quaternary science reviews, 118, 194-210. hublin j.j., roebroeks w. (2009) ebb and flow or regional extinctions? on the character of neandertal occupation of northern environments. comptes rendus palevolution, 8, 503-509. improta l., bagh s., de gori p., valoroso l., pastori m., piccinini d., chiarabba c., anselmi m., buttinelli m. (2017) reservoir structure and wastewater‐ induced seismicity at the val d'agri oilfield (italy) shown by three‐dimensional vp and vp/vs local earthquake tomography. journal of geophysical research, solid earth, 122 (11), 9050-9082. ipcc (2013) climate change 2013: the physical science basis. contribution of working group i to the fifth assessment report of the intergovernmental panel on climate change. stocker t.f., qin d., plattner g.-k., tignor m., allen s.k., boschung j., nauels a., xia y., bex v., midgley p.m. (ed. by). cambridge university press, cambridge, 1535 pp. ipcc (2018) global warming of 1.5°c. an ipcc special report on the impacts of global warming of 1.5°c above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty. masson-delmotte v., zhai p., pörtner h.-o., roberts d., skea j., shukla p.r., pirani a., moufouma-okia w., péan c., pidcock r., connors s., matthews j.b.r., chen y., zhou x., gomis m.i., lonnoy e., maycock t., tignor m., waterfield t. (ed. by). cambridge university press, cambridge, in press. ispra (2018) dissesto idrogeologico in italia: pericolosità e indicatori di rischio rapporti 287/2018. www.isprambiente.gov.it/files2018/ pubb l i caz ion i / rappor t i / rappor to -d isses to idrogeologico/rapporto_dissesto_idrogeologico_ ispra_287_2018_web.pdf. last access december 2020. iucn (2020) the iunc red list. summary statistics, table 9. www. iucnred l i s t .o rg / resources /summary statistics#summary izdebski a., holmgren k., weiberg e., stocker s.r., büntgenfg u., florenzano a., gogou a., leroy s.a.g.. luterbacher j., martrat b., masi a., mercuri a.m., montagna p., sadori l., schneider a., sicre m.-a., triantaphyllou m., xoplakil e. (2016) realising consilience: how better communication between archaeologists, historians and using the past to envisage a better future: the approach of a quaternary scientist 271 https://doi.org/10.1126/science.abc5654 https://agupubs.onlinelibrary.wiley.com/action/dosearch?contribauthorstored=improta%2c+l https://agupubs.onlinelibrary.wiley.com/action/dosearch?contribauthorstored=bagh%2c+s https://agupubs.onlinelibrary.wiley.com/action/dosearch?contribauthorstored=de+gori%2c+p https://agupubs.onlinelibrary.wiley.com/action/dosearch?contribauthorstored=valoroso%2c+l https://agupubs.onlinelibrary.wiley.com/action/dosearch?contribauthorstored=pastori%2c+m https://agupubs.onlinelibrary.wiley.com/action/dosearch?contribauthorstored=piccinini%2c+d https://agupubs.onlinelibrary.wiley.com/action/dosearch?contribauthorstored=chiarabba%2c+c https://agupubs.onlinelibrary.wiley.com/action/dosearch?contribauthorstored=anselmi%2c+m https://agupubs.onlinelibrary.wiley.com/action/dosearch?contribauthorstored=buttinelli%2c+m natural scientists can transform the study of past climate change in the mediterranean. quaternary science reviews, 136, 5-22. jablonski d. (1994) extinctions in the fossil record. philosophical transactions of the royal society of london. series b: biological sciences, 344(1307), 11-17. koch a., brierley c., maslin m.m., lewis s.l. (2019) earth system impacts of the european arrival and great dying in the americas after 1492. quaternary science reviews, 207, 13-36. leverett r.t., masino s.a., moomaw w.r. (2021) older eastern white pine trees and stands accumulate carbon for many decades and maximize cumulative carbon. frontiers in forests and global change, 4, 620450. lirer l., petrosino p., alberico i. (2010) hazard and risk assessment in a complex multi-source volcanic area: the example of the campania region, italy, bulletin of volcanology, 72, 411-429. luterbacher j., newfield t.p., xoplaki e., nowatzki e., luther n., zhang m., khelifi n. (2020) past pandemics and climate variability across the mediterranean. euro-mediterranean journal for environmental integration, 5, 46. mace g.m., reyers b., alkemade r., biggs r., chapin iii f.s., cornell s.e., díaz s., jennings s., leadley p., mamby p.j., purvis a., sholes r.j., aeddon a.w.r., solan m., steffen w., woodward g. (2014) approaches to defining a planetary boundary for biodiversity. global environmental change, 28, 289-297. mack m.c., walker x.j., johnstone j.f., alexander h.d., melvin a.m., mélanie j., miller s.n. (2021) carbon loss from boreal forest wildfires offset by increased dominance of deciduous trees. science, 372, 280-283. magnuson j.j. (1990) long-term ecological research and the invisible present. bioscience, 40(7), 495501. maier a., lehmkuhl f., ludwig p., melles m., schmidt i., shao y., zeeden c., zimmerman a. (2016) demographic estimates of hunter-gatherers during the last glacial maximum in europe against the background of palaeoenvironmental data. quaternary international, 425, 49-61. mandle l., salzman j., daily g.c. (2019) green growth that works: natural capital policy and finance mechanisms from around the world. island press, washington dc. manenti r., mori e., di canio v., mercurio s., picone m., caffi m., brambilla m., ficetola g.f., rubolini d. (2020) the good, the bad and the ugly of covid-19 lockdown effects on wildlife conservation: insights from the first european locked down country. biological conservation, 249, 108728. doi: 10.1016/j.biocon.2020.108728 mariani g.s., muntoni i.m., zerboni a. (2020) the eneolithic/bronze age transition at tegole di bovino (apulia): geoarchaeological evidence of climate change and land-use shift. quaternary, 3(2), 14. matthews j.a., winkler s., wilson p., tomkins m.d., dortch j.m., richard w., hill j.l., owen g., vater a.e. (2018) small rock-slope failures conditioned by holocene permafrost degradation: a new approach and conceptual model based on schmidthammer exposure-age dating, jotunheimen, southern norway. boreas, 47, 1144-1169. doi: 10.1111/bor.12336 mcmichael a.j. (2012) insights from past millennia into climatic impacts on human health and survival. pnas proceedings of the national academy of sciences, 109(13), 4730-4737. mirtl m., kuhn i., montheith d., bäck j., orenstein d., provenzale a., zacharias s. haase p., shachak m. (2021) whole system approach for in-situ research on life supporting systems in the anthropocene (wails), egu general assembly 2021, online, 19-30 apr 2021, egu21-16425. doi: 10.5194/egusphere-egu21-16425 monjeau j.a., araujo b., abramson g., kuperman m.n., laguna m.f., lanata j.l. (2017) the controversy space on quaternary megafaunal extinctions. quaternary international, 431, 194-204. mordechai l., eisenberg m., newfield t. p., izdebski a., kay j.e., poinar h. (2019) the justinianic plague: an inconsequential pandemic? pnas proceedings of the national academy of sciences, 16(51), 25546-25554. morrison k.d., hammer e., boles o., madella m., whitehouse n., gaillard m.-j., bates j., vander linden m., merlo s., yao a., popova l., chad hill a., antolin f., bauer a., biagetti s., bishop r.r., buckland p., cruz p., dreslerová d., dusseldorp g., ellis e., filipovic d., foster t., hannaford m.j., harrison s.p., hazarika m., hajnalka h., hilpert j., kaplan j.o., kay a., goldewijk k.k., kolář j., kyazike e., laabs j., lancelotti c., lane p., lawrence d., lewis k., lombardo u., lucarini g., arroyo-kalin m., marchant r., mayle f., mcclatchie m., mcleester m., mooney s., moskal-del hoyo m., navarrete v., ndiema e., góes neves e., nowak m., out w.a., petrie c., phelps l.n., pinke z., rostain s., russell t., sluyter a. (2021) mapping past human land use using archaeological data: a new classification for global land use synthesis and data harmonization. plos one, 16(4), e0246662. morse n.b., pellissier p.a., cianciola e.n., brereton r.l., sullivan m.m., shonka n.k. wheeler t.b., mcdowell w.h. (2014) novel ecosystems in the anthropocene: a revision of the novel ecosystem concept for pragmatic applications. ecology and society, 19(2), 12. moschetti m.p., hartzell s.h., herrmann r.b. (2019) rupture model of the m5.8 pawnee, oklahoma, earthquake from regional and teleseismic waveforms. geophysical research letters, 46(5), 2494250. doi: 0.1029/2018gl081364 natural hazard risk atlas (2015) natural hazard risk atlas. verisk maplecroft, bath, uk. nelson c.h., gutiérrez pastor j., goldfinger c., escutia c. (2012) great earthquakes along the western united states continental margin: implications for hazards, stratigraphy and turbidite lithology, natu capotondi l. et al. 272 https://doi.org/10.5194/egusphere-egu21-16425 https://agupubs.onlinelibrary.wiley.com/action/dosearch?contribauthorstored=hartzell%2c+s+h https://agupubs.onlinelibrary.wiley.com/action/dosearch?contribauthorstored=herrmann%2c+r+b ral hazards and earth system sciences, 12, 31913208. doi:10.5194/nhess-12-3191-2012 newbold t., hudson l.n., arnell a.p., contu s., de palma a., ferrier s., hill s.l.l., hoskins a.j., lysenko i., phillips h.r., burton v.j., chng c.w.t., emerson s., gao d., pask-hale g., hutton j., jung m., sanchez-ortiz k., simmons b.i., whitmee s.w., zhang h., scharlemann j.p.w., purvis a. (2016) has land use pushed terrestrial biodiversity beyond the planetary boundary? a global assessment. science, 353(6296), 288-291. doi: 10.1126/science.aaf2201 nicoll k., zerboni a. (2020) is the past key to the present? observations of cultural continuity and resilience reconstructed from geoarchaeological records. quaternary international, 545, 119-127. doi: 10.1016/j.quaint.2019.02.012 nogué s., de nascimento l., froyd c.a., wilmshurst j.m., de boer e.j., coffey e.e.d., whittaker r.j., fernández-palacios j.m., willis k.j. (2017) island biodiversity conservation needs palaeoecology. nature ecology & evolution, 1, 0181. nogué s., santos a.m.c., birks h.j.b., björck s., castilla-beltrán a., connor s., de boer e.j., de nascimento l., felde v.a., fernández-palacios j.m., froyd c.a., haberle s.g., hooghiemstra h., sietze k.l., norder j., peñuelas j., prebble m., stevenson j., whittaker r.j., willis k.j., wilmshurst j.m., steinbauer m.j. (2021) the human dimension of biodiversity changes on islands. science, 372, 488-491. odgaard b.v. (1999) fossil pollen as a record of past biodiversity. journal of biogeography, 26 (1), 7-17. palombo m.r. (2021) -thinking about the biodiversity loss in this changing world. geosciences, 11, 370. doi: 10.3390/ geosciences11090370 patton a.i., rathburn s.l., capps d.m. (2019) landslide response to climate change in permafrost regions. geomorphology, 340, 116-128. payne j.l., bush a.m., heim n.a., knope m.l., mccauley d.j. (2016) ecological selectivity of the emerging mass extinction in the oceans. science, 353(6305), 1284-1286. perego r. (2017) contribution to the development of the bronze age plant economy in the surrounding of the alps: an archaeobotanical case study of two early and middle bronze age sites in northern italy (lake garda region). phd thesis, university of basel, basel. pfahl s., o’gorman p.a., fischer e.m. (2017) understanding the regional pattern of projected future changes in extreme precipitation. nature climate change, 7, 423-427. pini r., ravazzi c., raiteri l., guerreschi a., castellano l., comolli r. (2017) from pristine forests to high -altitude pastures: an ecological approach to prehistoric human impact on vegetation and landscapes in the western italian alps. journal of ecology, 105, 1580-1597. pini r., ravazzi c., comolli r., perego r., castellano l., croci c., de amicis m., abu el khair d., furlanetto g., marsetti d. (2020) life on a hilltop: vegetation history, plant husbandry and pastoralism at the dawn of bergamo-bergomum (northern italy; 15th to 7th century bc). vegetation history and archaeobotany, 30, 525-553. doi: 10.1007/s00334-020-00802-1 posth c., renaud g., mittnik a., drucker d.g., rougier h., cupillard c., valentin f., thevenet c., furtwängler a., wißing c., francken m., malina m., bolus m., lari m., gigli e., capecchi g., crevecoeur i., beauval c., flas d., germonpré m., van der plicht j., cottiaux r., gély b., ronchitelli a., wehrberger k., grigorescu d., svoboda j., semal p., caramelli d., bocherens h., harvati k., conard n.j., haak w., powell a., krause j. (2016) pleistocene mitochondrial genomes suggest a single major dispersal of non-africans and a late glacial population turnover in europe. current biology, 26, 827-833. prata j.c., silva a.l., walker t.r., duarte a.c., rochasantos t. (2020) covid-19 pandemic repercussions on the use and management of plastics. environmental science & technology, 54(13), 7760-7765. price s.j., ford j.r., cooper a.h., neal c. (2011) humans as major geological and geomorphological agents in the anthropocene: the significance of artificial ground in great britain. philosophical transactions of the royal society a, 369, 10561084. rascovan n., sjögren k.g., kristiansen k., nielsen r., willerslev e., desnues c., rasmussen s. (2019) emergence and spread of basal lineages of yersinia pestis during the neolithic decline. cell, 176 (1-2), 295-305. raup d.m., sepkoski j.j. jr. (1986) periodic extinction of families and genera. science, 231, 833-836. regattieri e., zanchetta g., isola i., zanella e., drysdale r.n., hellstrom j.c., zerboni a., dallai l., tema e., lanci l., costa e., magrì f. (2019) holocene critical zone dynamics in an alpine catchment inferred from a speleothem multiproxy record: disentangling climate and human influences. scientific reports, 9, 17829. robb j., van hove d. (2003) gardening, foraging and herding: neolithic land use and social territories in southern italy. antiquity, 77(296), 241-254 roebroeks w., villa p. (2011) on the earliest evidence for habitual use of fire in europe. pnas proceedings of the national academy of sciences, 108 (13), 5209-5214. rotilio g. (2015) il migratore onnivoro. carocci editore, roma. 166 pp. rubino m., etheridge d.m., thornton d.p., howden r., allison c.e., francey r.j., langenfelds r.l., steele l.p., trudinger c.m., spencer d.a., curran m.a.j., van ommen t.d., smith a.m. (2019) revised records of atmospheric trace gases co2, ch4, n2o, and  13 c-co2 over the last 2000 years from law dome, antarctica. earth system science data, 11, 473-492. doi: 10.5194/essd-11-473-2019 ruddiman w.f. (2007) the early anthropogenic hy using the past to envisage a better future: the approach of a quaternary scientist 273 https://doi.org/10.5194/essd-11-473-2019 pothesis: challenges and responses. reviews of geophysics, 45(4), rg4001. ruddiman w.f. (2010) plows, plagues, and petroleum: how humans took control of climate. princeton university press, princeton. rutz c., loretto m.c., bates a.e., davidson s.c., duarte c.m, jetz w., johnson m., kato a., kays r., mueller t., primack r.b., topert-coudert y., tucker m.a., wikelski m., cagnacci f. (2020) covid-19 lockdown allows researchers to quantify the effects of human activity on wildlife. nature ecology evolution, 4, 1156-1159. doi: 10.1038/s41559-020-1237-z sadori l., jahns s., peyron o. (2011) mid-holocene vegetation history of the central mediterranean. the holocene, 21(1), 117-129. scholes r.j., biggs r. (2005). a biodiversity intactness index. nature, 434 (7029), 45-49. schneider von deimling t., grosse g., strauss j., schirrmeister l., morgenstern a., schaphoff s., meinshausen m., boike j. (2015) observationbased modelling of permafrost carbon fluxes with accounting for deep carbon deposits and thermokarst activity. biogeosciences, 12, 3469-3488. doi: 10.5194/bg-12-3469-2015 soldati m., corsini a., pasuto a. (2004) landslides and climate change in the italian dolomites since the late glacial. catena, 55, 141-161. doi: 10.1016/ s0341-8162(03)00113-9. spano d., mereu v., bacciu v., marras s., trabucco a., adinolfi m., barbato g., bosello f., breil m., chiriacò m.v., coppini g., essenfelder a., galluccio g., lovato t., marzi s., masina s., mercogliano p., mysiak j., noce s., pal j., reder a., rianna g., rizzo a., santini m., sini e., staccione a., villani v., zavatarelli m. (2020) analisi del rischio. i cambiamenti climatici in italia. doi: 10.25424/cmcc/analisi_del_rischio spyrou m.a., bos k.i., herbig a., krause j. (2019a) ancient pathogen genomics as an emerging tool for infectious disease research. nature reviews genetics, 20(6), 323-340. spyrou m.a., keller m., tukhbatova r.i., scheib c.l., nelson e.a., valtueña a.a., neumann g.u., walker d., alterauge a., carty n., cessford c., fetz h., gourvennec m., hartle r., henderson m., von heyking k., inskip s.a., kacki s., key f., knox e.l., later c., maheshwari-aplin p., peters j., robb j.e., schreiber j., kivisild t., castex d., lösch s., harbeck m., herbig a., bos k.i., krause j. (2019b) phylogeography of the second plague pandemic revealed through analysis of historical yersinia pestis genomes. nature communications, 10(1), 1-13. steffen w., broadgate w., deutsch l., gaffney o., ludwig c. (2015) the trajectory of the anthropocene: the great acceleration. the anthropocene review, 2, 81-98. steffen w., rockström j., richardson k., lenton t.m., folke c., liverman d., summerhayes c.p., barnosky a.d., cornell s.e., crucifix m., donges j.f., fetzer i., lade s.j., scheffer m., winkelmann r., schellnhuber h.j. (2018) trajectories of the earth system in the anthropocene. pnas proceedings of the national academy of sciences, 115(33), 8252-8259. doi: 10.1073/pnas.1810141115 stoneking m., krause j. (2011) learning about human population history from ancient and modern genomes. nature reviews genetics, 12, 603-614. stucchi m., meletti c., montaldo v., akinci a., faccioli e., gasperini p., malagnini l., valensise g. (2004) pericolosità sismica di riferimento per il territorio nazionale mps04 [data set]. istituto nazionale di geofisica e vulcanologia (ingv). doi: 10.13127/sh/mps04/ag thierry p., neri m., le cozannet g., jousset p., costa a. (2015) preface: approaches and methods to improve risk management in volcanic areas. natural hazards earth system sciences, 15, 197201. tomašových a., albano p.g., fuksi t., gallmetzer i., haselmair a., kowalewski m., nawrot r., nervolić v., scarponi d., zuschin m. (2020) ecological regime shift preserved in the anthropocene stratigraphic record. proceedings of the royal society b, 287(1929), 20200695. doi: 10.1098/rspb.2020.0695 unisdr (2009) unisdr: terminology on disaster risk reduction. united nations office on disaster risk reduction. geneva, 35 pp. vaesen k., dusseldorp g.l., brandt m.j. (2021) an emerging consensus in palaeoanthropology: demography was the main factor responsible for the disappearance of neanderthals. scientific reports, 11, 4925. wagner d.m., klunk j., harbeck m., devault a., waglechner n., sahl j.w., enk j., birdsell d.n., kuch m., lumibao c., poinar d., pearson t., fourment m., golding b., riehm j.m., earn d.j.d., dewitte s., rouillard j.m., grupe g., wiechmann i., bliska j.b., keim p., scholz h.c., holmes e.c., poinar h. (2014) yersinia pestis and the plague of justinian 541-543 ad: a genomic analysis. the lancet infectious diseases, 14(4), 319-326. waters c.n., zalasiewicz j., summerhayes c., barnosky a.d., poirier c., gałuszka a., cearreta a., edgeworth m., ellis e.c., ellis m., jeandel c., leinfelder r., mcneill j. r., richter d. d., steffen w., syvitski j., vidas d., wagreich m., williams m., zhisheng a., grinevald j., odada e., oreskes n., wolfe a.p. (2016) the anthropocene is functionally and stratigraphically distinct from the holocene. science, 351(6269), 137-148. williams m., zalasiewicz j., davies n., mazzini i., goiran j.p., kane s. (2014) humans as the third evolutionary stage of biosphere engineering of rivers. anthropocene, 7, 57-63. doi: 10.1016/j.ancene.2015.03.003. willis k.j., birks h.j.b. (2006) what is natural? the need for a long-term perspective in biodiversity conservation. science, 314, 1261-1265. willis k.j., macdonald g.m. (2011) long-term ecological records and their relevance to climate change predictions for a warmer world. annual review of ecology, evolution, and systematics, 42, 267-287. capotondi l. et al. 274 https://doi.org/10.1038/s41559-020-1237-z https://www.nature.com/articles/s41467-019-12154-0#auth-craig-cessford https://www.nature.com/articles/s41467-019-12154-0#auth-hermann-fetz https://www.nature.com/articles/s41467-019-12154-0#auth-micha_l-gourvennec https://www.nature.com/articles/s41467-019-12154-0#auth-robert-hartle https://www.nature.com/articles/s41467-019-12154-0#auth-michael-henderson https://www.nature.com/articles/s41467-019-12154-0#auth-kristin-von_heyking https://www.nature.com/articles/s41467-019-12154-0#auth-sarah_a_-inskip https://www.nature.com/articles/s41467-019-12154-0#auth-sacha-kacki https://www.nature.com/articles/s41467-019-12154-0#auth-felix_m_-key https://www.nature.com/articles/s41467-019-12154-0#auth-elizabeth_l_-knox https://www.nature.com/articles/s41467-019-12154-0#auth-christian-later https://www.nature.com/articles/s41467-019-12154-0#auth-prishita-maheshwari_aplin https://www.nature.com/articles/s41467-019-12154-0#auth-elizabeth_l_-knox https://www.nature.com/articles/s41467-019-12154-0#auth-christian-later https://www.nature.com/articles/s41467-019-12154-0#auth-john_e_-robb https://www.nature.com/articles/s41467-019-12154-0#auth-j_rgen-schreiber https://www.nature.com/articles/s41467-019-12154-0#auth-toomas-kivisild https://www.nature.com/articles/s41467-019-12154-0#auth-dominique-castex https://www.nature.com/articles/s41467-019-12154-0#auth-sandra-l_sch https://www.nature.com/articles/s41467-019-12154-0#auth-alexander-herbig https://www.nature.com/articles/s41467-019-12154-0#auth-kirsten_i_-bos https://doi.org/10.13127/sh/mps04/ag https://doi.org/10.1098/rspb.2020.0695 zastrow m. (2019) china’s tree-planting drive could falter in a warming world. nature, 573, 474-475. zeberg h., pääbo s. (2020) the major genetic risk factor for severe covid-19 is inherited from neanderthals. nature, 587, 610-612. doi: 10.1038/s41586-020-2818-3 zerboni a., nicoll k. (2019) enhanced zoogeomorphological processes in arid north africa on the human-impacted landscape of the anthropocene. geomorphology, 331, 22-35. ms. received: june 9, 2021 revised: august 5, 2021 accepted: september 22, 2021 available online: november 14, 2021 doi: 10.1146/annurev-ecolsys-102209-144704 wwf (2020) wwf living planet report 2020, accessed at ivingplanet.panda.org/about-the-living -planet-report yunus a.p. masago y., hijioka y. (2020) covid-19 and surface water quality: improved lake water quality during the lockdown. science of the total environment, 731, 139012. doi: 10.1016/j.scitotenv.2020.139012 zanchetta g., bini m., cremaschi m., magny m., sadori l. (2013) the transition from natural to anthropogenic-dominated environmental change in italy and the surrounding regions since the neolithic: an introduction. quaternary international, 303, 1-9. zanchettin d., bruni s., raicich f., lionello p., adloff f., androsov a., antonioli f., artale v., carminati e., ferrarin c., fofonova v., nicholls r.j., rubinetti s., rubino a., sannino g., spada g., thiéblemont r., tsimplis m., umgiesser g., vignudelli s., wöppelmann g., zerbini s. (2021) sea-level rise in venice: historic and future trends. natural hazards and earth system sciences, 21, 2643-2678. doi: 10.5194/nhess-21-2643-2021 using the past to envisage a better future: the approach of a quaternary scientist 275 https://doi.org/10.1016/j.scitotenv.2020.139012 https://www.x-mol.com/paperredirect/1326952606796521472 https://www.x-mol.com/paper/journal/113224 https://www.x-mol.com/paper/journal/113224 276 imp.tropeano& depositi carbonatici infrapleistocenici di tipo foramol in sistemi di scarpata (salento italia meridionale) marcello tropeano1, luigi spalluto2, massimo moretti2-3, piero pieri2-3 & luisa sabato2 1dipartimento di scienze geologiche, università della basilicata, campus di macchia romana, 85100, potenza <tropeano@unibas.it> 2dipartimento di geologia e geofisica, università di bari, via orabona 4, 70125, bari <l.spalluto@geo.uniba.it> <m.moretti@geo.uniba.it> <p.pieri@geo.uniba.it> <l.sabato@geo.uniba.it> 3centro interdipartimentale di ricerca per la valutazione e mitigazione del rischio sismico e vulcanico, università di bari, palazzo di scienze della terra, via orabona 4, 70125, bari riassunto: tropeano m., spalluto l., moretti m., pieri p. & sabato l., depositi carbonatici infrapleistocenici di tipo foramol in sistemi di scarpata (salento italia meridionale). it issn 0394-3356, 2004. la penisola salentina, fra otranto e santa maria di leuca, termina verso mare con un articolato e ripido pendio roccioso, che raccorda la porzione sommitale della regione (le serre salentine, una sorta di modesto altopiano costituito da blandi rilievi ed ampie depressioni orientati quasi ortogonalmente alla costa) al canale d'otranto nel mar ionio. il pendio roccioso è costituito da carbonati appartenenti a differenti unità stratigrafiche discordanti fra loro, la cui età è compresa fra il cretaceo ed il quaternario. fra questi depositi sono stati studiati i più giovani, infrapleistocenici, presenti nella parte bassa del pendio roccioso fino al livello del mare, attribuiti in letteratura alle calcareniti del salento e ritenuti, prima di questo lavoro, di ambiente costiero. questi depositi carbonatici di tipo foramol affiorano in maniera discontinua, presentano spessori variabili da pochi metri fino a diverse decine di metri e corrispondono a piccoli corpi isolati sviluppatisi in alcune brusche rientranze del pendio. in particolare, a porto miggiano (santa cesarea) ed a castro marina le successioni sono caratterizzate da lunghi clinoformi interrotti da nicchie di distacco di frane sottomarine evolutesi in piccoli canali effimeri. le nicchie di distacco sono cicatrizzate da backset mentre i canali sono riempiti o da depositi simili a quelli incisi o, caoticamente, dagli stessi materiali in frana. depositi di frana (slumps) ed altre soft-sediment deformation structures si riconoscono soprattutto nella parte bassa delle successioni, dove i clinoformi diminuiscono asintoticamente il loro angolo. l'insieme dei dati sedimentologici porta ad interpretare queste calcareniti come depositi di scarpata e base di scarpata sottomarina, alimentati sia dai sistemi carbonatici di mare sottile presenti fra le serre che da produzione lungo il pendio. questi sistemi si sviluppavano in indentazioni del pendio e costituivano piccoli ed isolati aprons di profondità non elevata. l'interpretazione qui proposta porta a rivedere sia l'attribuzione formazionale dei depositi in oggetto sia le ipotesi circa l'evoluzione pleistocenica del salento. si suggerisce infatti di attribuire i depositi studiati alla formazione della calcarenite di gravina, nota soprattutto nell'area delle murge come l'unità che segna la fase di subsidenza dell'avampaese apulo indotta dalla propagazione verso est dell'orogene sudappenninico; inoltre, la posizione nella parte bassa del pendio dei depositi studiati, a differenza di quanto proposto in precedenza in letteratura, non indicherebbe una fase di stazionamento del mare lungo il pendio dopo un'iniziale fase di sollevamento infrapleistocenica della regione. il sollevamento sarebbe avvenuto solo successivamente, così come evidenziato dalla presenza di una serie di terrazzi marini medio-suprapleistocenici riconosciuti nell'area salentina da altri autori a partire da quote superiori rispetto a quelle di affioramento dei depositi studiati. abstract: tropeano m., spalluto l., moretti m., pieri p. & sabato l., lower pleistocene foramol-type carbonate deposits in slope systems (salento southern italy). it issn 0394-3356, 2004. along the eastern salento coast (southern italy), cretaceous to quaternary carbonates crop out on a 100 m high escarpment that connects a wide and relatively flat area to the otranto strait (ionian sea). along the escarpment, faulted and tilted cretaceous and eocene limestones record deposition in shallow-marine and marginal carbonate environments. younger carbonates disconformably overlie this substratum and they formed when the region was partially submerged. accordingly, priabonian to messinian carbonates which crop out along the escarpment were interpreted as slope deposits linked to reef systems developed on the margin of the top area, while lower pleistocene carbonates cropping out at the base of the same escarpment were considered coastal in origin and formed during the uplift of the region. stratigraphic and sedimentologic studies carried out on these lower pleistocene carbonates demonstrate that also these deposits should be considered as slope deposits. the studied carbonates are foramol-type ones and discontinuously crop out along the lower part of the escarpment. they show a variable thickness (from a few meters up to several tens) and often exhibit a fan morphology; they correspond to small isolated bodies (up to a few km2 wide) developed in some indentations of the escarpment, and are composed of coarse skeletal grains mainly deposited via slumpings or grain flows. successions are characterized by long clinobeds cut by slump scars downward passing to gullies; backsets, slumps and chaotic deposits fill these erosional features. clinobeds are alternatively made up of molechfor and rodhalgal facies which respectively record resedimentation by grain flows of shallow marine carbonates developed on top of the region and along-slope carbonate production. depositional systems correspond to small shallow-marine aprons whose discontinuous distribution along the escarpment (inside indentations) should be considered an original feature. the idea that these deposits record the sicilian sea-level along the escarpment should be abandoned as they are not coastal deposits. the studied deposits should be correlated to the calcarenite di gravina formation which in other areas of the apulian foreland (which the salento region belongs to) are considered as the deposits linked to the subsidence induced by the estward migration of the southapennines orogenic system. the quaternary uplift of the salento region should be begun after the deposition of the studied slope deposits, as indicated also by a series of middle-upper pleistocene marine terraces which start at heights higher than those ones of the studied deposits. parole chiave: carbonati di tipo foramol; depositi di scarpata; pleistocene inferiore; salento; italia meridionale. keywords: foramol-type carbonates; slope deposits; early pleistocene; salento; southern italy. il quaternario italian journal of quaternary sciences 17(2/2), 2004, 537-546 538 m. tropeano et al. 1. introduzione in puglia, principalmente nelle murge e nel salento, affiorano diffusamente carbonati plio-pleistocenici formatisi in contesti ambientali riconducibili a mare sottile (ciaranfi et al., 1988). questi carbonati, di ambiente temperato (pieri, 1975) e con caratteri di tipo foramol (tropeano, 1994a; 1994b), si deponevano sull'avampaese apulo quando la regione, caratterizzata da un esteso ed articolato sistema di alti e bassi morfostrutturali, per progressiva subsidenza evolveva da area emersa a vasto arcipelago (tropeano et al., 2002a). i caratteri morfostrutturali del substrato, dovuti sia all'evoluzione tettonica terziaria dell'avampaese (pieri, 1980; iannone & pieri, 1982; tozzi, 1993; festa, 2003) sia, in parte, a tettonica sinsedimentaria (pieri et al., 1997), determinavano lo sviluppo di differenti sistemi deposizionali e facies nei diversi contesti di sedimentazione incontrati dalla trasgressione indotta dalla subsidenza (iannone & pieri, 1979). in pratica si sviluppava sedimentazione carbonatica sia nei bracci di mare poco profondi che separavano gli alti morfostrutturali, sia lungo i versanti di questi ultimi (isole in via di sommersione), sia sulla loro sommità (banchi) quando gli alti venivano annegati (tropeano & sabato, 2000). i differenti sistemi deposizionali evolvevano su un substrato roccioso carbonatico fagliato, ed i loro caratteri erano determinati sia dalla alternanza dei bassi e degli alti morfostrutturali sia, sui versanti di questi ultimi, dalla spaziatura delle faglie e dalla entità dei loro rigetti verticali. se i versanti erano costituiti da estesi blocchi strutturati da faglie a piccolo rigetto, si sviluppavano rampe carbonatiche a debole pendio, caratterizzate da sedimentazione subtidale e rari corpi di spiaggia (tropeano & sabato, 2000); se i versanti presentavano un pendio più pronunciato, corrispondente ad un esteso blocco roccioso tiltato o ad un substrato roccioso strutturato da faglie molto ravvicinate, si sviluppavano sistemi deposizionali caratterizzati da corpi sigmoidali di ambiente costiero (con geometrie tipo gilbert) passanti distalmente in modo rapido ad ambienti di offshore (pomar & tropeano, 2001); se i versanti erano strutturati a gradinata da faglie con rigetti decametrici, i sistemi deposizionali a ridosso delle strutture erano caratterizzati da depositi di falesia a volte associati a delta ghiaiosi (sabato, 1996; tropeano & sabato, 2000). nelle depressioni, invece, si sviluppavano sistemi deposizionali relativi ad aree di canale o di golfo, sia protette rispetto al moto ondoso, talvolta con sedimentazione di tipo salmastro, sia aperte rispetto al moto ondoso (iannone & pieri, 1979; d'alessandro et al., 2004). sulla sommità dei rilievi, una volta sommersi, si sviluppavano infine piccole piattaforme carbonatiche isolate, caratterizzate da sedimentazione subtidale (tropeano, 1994a; 1994b). nel salento meridionale, lungo la costa che si affaccia sul canale d'otranto (fra otranto e santa maria di leuca), alcune delle successioni carbonatiche infrapleistoceniche affioranti sono state recentemente attribuite a sistemi deposizionali di scarpata e di base di scarpata (tropeano et al. 2000; 2002b), differenti quindi rispetto ai sistemi noti in letteratura e fin qui ricordati. il presente lavoro, a carattere preliminare, intende offrire alcuni elementi interpretativi di questi nuovi sistemi deposizionali riconosciuti, che portano a proporre un quadro paleogeografico locale differente da quello noto in letteratura, e ad avanzare alcune considerazioni di carattere neotettonico e formazionale sull'area salentina investigata. 2. inquadramento geologico il salento rappresenta la porzione meridionale dell'avampaese apulo emerso (fig. 1a) e, come le altre porzioni dell'avampaese, è costituito in affioramento da una potente successione carbonatica mesozoica coperta, in maniera discontinua, da sottili unità più recenti a prevalente costituzione carbonatica (palmentola, 1987; ricchetti et al., 1988). lo studio è stato condotto nella parte sudorientale della penisola salentina, che rappresenta, sotto il profilo morfologico, una sorta di modesto altopiano limitato ad e (verso mare) da una scarpata a luoghi fortemente acclive. l’altopiano è caratterizzato dall'alternanza di blandi rilievi (le serre salentine), con elevazioni massime di circa 190 m rispetto all'attuale livello del mare, e di estese e poco profonde depressioni, le cui quote raggiungono circa 120 m sul livello del mare. questo sistema morfostrutturale, con orientazione nno-sse, ha condizionato lo sviluppo delle unità marine più recenti, che si sono deposte e/o conservate nelle aree depresse prima del sollevamento quaternario della regione (martinis, 1962; palmentola & vignola, 1980) (fig. 1a). la fascia costiera che si affaccia sul canale d'otranto (fra otranto e santa maria di leuca) è orientata quasi ortogonalmente al sistema di rilievi e depressioni delle serre e qui, come accennato, l’altopiano termina verso mare con un articolato e ripido pendio roccioso che raccorda bruscamente l'area delle serre all'attuale piattaforma continentale (budillon & aiello, 1999). il pendio roccioso è costituito in affioramento da carbonati appartenenti a differenti unità stratigrafiche discordanti fra loro e la cui età è compresa fra il cretaceo ed il quaternario. in sintesi, le unità carbonatiche supracretaciche e medioeoceniche rappresentano il substrato deformato su cui si sono addossate unità più giovani; infatti il pendio roccioso attualmente esposto ricorda per lunghi tratti il pendio sommerso che avrebbe caratterizzato la regione dal priaboniano al messiniano e sul quale si sedimentavano i depositi di scarpata relativi ai coevi sistemi deposizionali carbonatici di scogliera che si sviluppavano sul margine della regione salentina (bosellini et al., 1999). per quanto riguarda le unità più giovani, plio-pleistoceniche, affioranti nella porzione meridionale del salento e in parte lungo lo stesso pendio roccioso, queste sono state attribuite a differenti unità formazionali (formazione di leuca, formazione di uggiano la chiesa, calcareniti del salento) e la loro età ed il loro significato ambientale e paleogeografico sono tuttora oggetto di dibattito (a titolo di esempio, la formazione di uggiano la chiesa è considerata di età pliocene medio-superiore da bossio et al., 1987c, di età pliocene medio-santerniano da bossio et al., 1997, e di età pliocene superiore da bosellini et al., 1999). in particolare, le calcareniti del salento affioranti nella parte bassa del pendio roccioso ed oggetto del presente lavoro (fig. 1b) sono state genericamente descritte nei lavori più recenti come depositi costieri (bosellini et al., 1999), e la loro posizione nella parte bassa del pendio è stata addebitata ad uno stazionamento del mare nel siciliano, successivo quindi ad una fase infrapleistocenica (emiliana) di sollevamento della regione (bossio et al., 1987a, 1987b). depositi carbonatici di età relativamente più antica (formazione di uggiano la chiesa) sono invece segnalati sul rilievo ed occupano ampie aree depresse delle serre (fig. 1b). questa ricostruzione non sembra però coerente con alcuni studi di carattere paleoecologico e geomorfologico secondo i quali i depositi carbonatici infrapleistocenici del porto di castro (una delle tipiche località di affiora539depositi carbonatici ... mento delle calcareniti del salento lungo il pendio roccioso oggetto di studio) andrebbero riferiti ad ambienti profondi almeno 100 m, quando anche la parte sommitale della regione salentina era ricoperta da una lama d'acqua non inferiore alla decina di metri, e sarebbero da attribuire sia all'emiliano che al siciliano (taddei ruggiero, 1983; 1993; 1994). per quanto riguarda invece la successione calcarenitica di porto miggiano (anch'essa affiorante nella parte bassa del pendio ed oggetto di questo studio), già attribuita al calabriano da rossi & ungaro (1969), questa è considerata di età siciliana da bossio et al. (1987b) e, nella sua porzione più elevata, di età tirreniana da zezza (1983). fig. 1 a) carta geologica schematica della porzione meridionale della penisola salentina. si noti la distribuzione delle unità plio-pleistoceniche rispetto a quelle più antiche, che rappresentano i rilievi delle serre salentine. b) carta geologica schematica dell’area studiata. si noti: la posizione alla base della scarpata dei depositi attribuiti in letteratura alle calcareniti del salento; la loro ubicazione rispetto alle faglie attive durante la sedimentazione; la loro distribuzione in relazione a quella dei depositi attribuiti in letteratura alla formazione di uggiano la chiesa (da bossio et al., 1997, semplificata). a) geological sketch map of the southern part of the salento peninsula (see the insect for the location in italy). the plio-pleistocene deposits fill morphostructural depressions between older rocks. b) geological sketch map of the study area. the studied deposits (calcareniti del salento) rest at the base of a rocky slope. see both their location respect to sinsedimentary faults and distribution of the uggiano la chiesa formation at the top of the relief (after bossio et al., 1997, modified). 540 per quanto riguarda infine gli aspetti di tipo strutturale, i principali lineamenti tettonici riconosciuti nell'area interessano tutti i termini affioranti lungo il pendio roccioso e presentano rigetti variabili da qualche metro fino ad oltre 200 m (martinis, 1962; 1967). rispetto alle successioni infrapleistoceniche oggetto di studio si può quindi riconoscere un'attività pre-, sin-, e post-deposizionale di queste strutture (moretti, 1997). le strutture riconosciute sono essenzialmente faglie subverticali orientate nno-sse e no-se; sono presenti inoltre sia direttrici trasversali alle precedenti che orientate n-s (sulla costa fra porto badisco e otranto, santa cesarea terme e presso tiggiano martinis, 1962). la maggior parte di queste faglie (soprattutto nel settore sud-occidentale) è di tipo trascorrente con successivi e/o alternati movimenti obliqui e di tipo normale (tozzi, 1993). 3. i depositi carbonatici infrapleistocenici di santa cesarea terme e castro marina nella parte bassa del pendio roccioso che si affaccia sul canale d'otranto, affiorano in maniera discontinua alcune successioni attribuite alla formazione delle calcareniti del salento e ritenute in letteratura di età siciliana (bossio et al., 1997; bosellini et al., 1999). localmente, questi affioramenti non superano i pochi chilometri quadrati di estensione e raggiungono spessori massimi di alcune decine di metri. vengono di seguito descritte ed interpretate le successioni affioranti in maniera spettacolare nei pressi di santa cesarea terme (porto miggiano) e di castro marina, entrambe già oggetto in precedenza di alcuni lavori di dettaglio (rossi & ungaro, 1969; taddei ruggiero, 1983; 1993; 1994; zezza, 1983; bossio et al., 1987a; 1987b). in entrambe le località le successioni si sviluppano in una brusca indentazione del pendio e sono limitate da faglie subverticali; in entrambi i casi è stata evidenziata una attività tettonica sinsedimentaria delle faglie (martinis, 1967; moretti, 1997). 3.1. descrizione le successioni infrapleistoceniche studiate presentano spessori variabili fino ad un massimo di circa 40-50 m e si addossano, in discordanza lungo pendio, sulle unità più antiche. uno dei caratteri interni più evidenti è la diffusa presenza di lunghi clinoformi, il cui angolo di inclinazione varia fino ad un massimo di 25°30°; l'immersione dei clinoformi è verso mare, coerente con l'originale orientazione del paleopendio roccioso, con tendenza ad orizzontalizzarsi asintoticamente verso l'attuale falesia costiera (fig. 2). i clinoformi sono rappresentati da strati, anche sottili, e banchi di spessore superiore al metro e sono costituiti da biocalcareniti, biocalciruditi e, subordinatamente, da calcisiltiti e rari orizzonti argillosi di colore verdastro; sono generalmente bioturbati, con aumento della bioturbazione verso il tetto degli strati. le litofacies riconosciute sono costituite da grainstones e packstones bioclastici ad alghe rosse, briozoi, echinidi, brachiopodi, rari coralli solitari e bivalvi, frequentemente in frammenti. in sezione sottile si riconoscono sia facies ricche in foraminiferi bentonici che facies ricche in foraminiferi planctonici, queste ultime associate a briozoi ed alghe rosse (fig. 3). gli strati presentano rare strutture interne, in genere laminazioni piane (o fantasmi di laminazione) parallele ai clinoformi. le superfici di strato, in tagli paralleli al pendio, appaiono ondulate a grande scala simulando strutture tipo hummocky di ampiezza dell'ordine della decina di metri. i clinoformi sono a volte tagliati da nette superfici erosive canalizzate (con canali di ampiezza di alcuni metri, pareti molto acclivi fino a subverticali e fondo inclinato verso mare) che passano lateralmente a superfici di strato. le forme canalizzate immergono verso mare, spesso con orientazione leggermente differente rispetto a quella dei foreset sottostanti tagliati dall'erosione. le facies di riempimento dei canali sono generalmente simili a quelle dei depositi incisi e, allontanandosi dai canali, le facies a contatto a letto ed a tetto delle superfici erosive non sono distinguibili. in alcuni casi però il riempimento dei canali presenta una complessa stratificazione incrociata, e, più raramente, è costituito da grossi intraclasti (di diametro fino a 50 cm) immersi in una matrice grossolana caotica (fig. 4); la morfologia degli intraclasti indica che la loro messa in posto è avvenuta allo stato plastico o semiconsolidato. inoltre, lungo pendio, sono state osservate strutture tipo backset impostatesi in presenza di brusche variazioni di pendenza delle superfici di appoggio del banco considerato (particolare della fig. 5). a diverse altezze nella successione, e comunque in affioramenti posti alla base del pendio, sono inoltre presenti strutture tipo slump in orizzonti deformati dello spessore di almeno 2-3 m (fig. 6). morfologicamente le strutture sono rappresentate da pieghe asimmetriche, thrusts con chiare superfici di decollement e faglie inverse, piem. tropeano et al. fig. 2 il piede delle calcareniti clinostratificate a porto miggiano toe of the clinobeds. porto miggiano locality. 541 ghe a scatola e strutture imbricate che interessano strati calcarenitici a differente granulometria (moretti, 1997). sono state osservate anche altre soft-sediment deformation structures come: intrusioni di sedimento liquefatto, load-casts e flame structures (moretti, 1997). le intrusioni di sedimento liquefatto (silt ben selezionato e finissimo) sono rappresentate da forme a "pera" od "imbuto" cioé molto strette verso il basso e svasate fino quasi ad orizzontali verso l'alto. le load-casts e le flame structures si rinvengono a vari livelli e sono rappresentate da ondulazioni del contatto fra calcareniti a diversa granulometria. le ondulazioni nella laminazione simulano larghi movimenti verso il basso (load-casts) e strette vie di fuga verso l'alto (flame structures). a luoghi la laminazione originaria risulta troncata da flussi provenienti dal basso. 3.2. interpretazione le facies bioclastiche che caratterizzano gli affioramenti descritti sono riconducibili a sistemi carbonatici di tipo foramol, con associazioni sia di tipo molechfor che di tipo rodhalgal (sensu carannate et al., 1988). in particolare, uno studio condotto da taddei ruggiero (1983) sui foraminiferi planctonici presenti in un campione significativo prelevato dalla successione di castro marina, indica che i sistemi si sviluppavano in climi temperato-temperato caldi non dissimili da quelli del mediterraneo attuale. non è possibile però ricondurre i caratteri stratigrafici e sedimentologici delle successioni studiate ai sistemi carbonatici di tipo foramol descritti per successioni parzialmente coeve affioranti nello stesso avampaese apulo (si veda il paragrafo introduttivo del presente lavoro). i banchi clinostratificati, notevolmente sviluppati in lunghezza e con appoggio asintotico nella parte bassa (troncato dalla falesia attuale), e la presenza di slumps indicano infatti che la sedimentazione delle successioni carbonatiche infrapleistoceniche di castro marina e di porto miggiano avveniva lungo un pendio sottomarino ed al suo piede. i lunghi clinoformi non sono sempre continui lateralmente per la presenza di forme erosive canalizzate che possono essere interpretate come nicchie di distacco di frane sottomarine (slump scars) evolutesi lungo pendio in depositi carbonatici ... fig. 3 esempi di facies riconosciute in sezione sottile: a) grainstone a foraminiferi bentonici e frammenti di bivalvi, alghe rosse ed echinidi; b) packstone con alghe rosse, briozoi e rari foraminiferi; c) packstone a briozoi e foraminiferi planctonici. thin sections of some representative facies: a) grainstone with bentic foraminifers and fragments of bivalvs, red algae ed echinoids; b) packstone with red algae, bryozoans and rare foraminifers; c) packstone with bryozoans and planctonic foraminifers. fig. 4 canale erosivo lungo le calcareniti clinostratificate; la freccia bianca indica un grosso intraclasto nel riempimento del canale. la scala è fornita dalle due persone in alto. località porto miggiano. erosional channel (gully) along clinobeds; the white arrow indicates a big intraclast in the infilling deposits. two people on top for scale. porto miggiano locality. 542 stretti e ripidi canali effimeri (gullies) causati dallo scorrimento della frana su materiali poco consolidati. nella parte inferiore del pendio, il riempimento dei canali era opera dello stesso materiale in frana, sia come deposito caotico a grossi intraclasti (debris flows) sia come classico deposito da slump (strati contorti). in alcuni casi l'erosione ed il riempimento multiplo dei canali determinano la presenza di una stratificazione incrociata molto complessa ma confinata lateralmente. per quanto riguarda le strutture tipo grandi hummocky, queste forme rappresentano un effetto di prospettiva su tagli paralleli al pendio di banchi inclinati a morfologia ondulata; l'ondulazione rappresenta zone di maggiore o minore accumulo dei sedimenti lungo pendio; non si tratta quindi di forme di fondo trattive ma di rilievi e depressioni orientati parallelamente al pendio in un m. tropeano et al. fig. 5 calcareniti clinostratificate a castro. nel particolare è evidenziato un backset. clinobedded calcarenites at castro locality. see the backset in the insect. materasso continuo ed aggradante di sedimenti. la presenza di backset lungo i clinoformi e la cicatrizzazione delle nicchie e dei canali da parte di sedimenti simili a quelli erosi, indicherebbe l'attività di flussi sedimentari tipo grain flow; questi processi erano episodici, come indicato dalla diffusa bioturbazione che aumenta nella parte alta degli strati e dei banchi. infine, le strutture deformative riconosciute oltre gli slumps, indicano che le facies in cui si sviluppavano erano poste nella parte bassa del pendio, in quanto intrusioni di sedimento, load casts e flames si possono originare per processi di liquefazione e fluidificazione indotti da aumento repentino del carico litostatico (overloading) in conseguenza di episodi di sedimentazione di massa. 4. discussione 4.1 sistemi deposizionali ed ipotesi paleogeografiche in base ai caratteri descritti e alla loro interpretazione si ritiene che le successioni studiate rappresentino il prodotto di una sedimentazione carbonatica di tipo foramol in ambienti di scarpata e di base di scarpata. ricordando che durante il pleistocene inferiore il sistema a blandi rilievi e depressioni delle serre salentine ed il pendio di raccordo verso il canale d'otranto erano già presenti, e che il sistema governava la distribuzione di aree emerse e sommerse del salento meridionale, può essere proposta una ipotesi paleogeografica relativa all'origine dei depositi studiati, coerente con le osservazioni sedimentologiche effettuate sulle successioni. le aree sommerse del sistema delle serre salentine, sede di attiva sedimentazione carbonatica di mare sottile, erano rappresentate da zone più o meno profonde (golfi o ampi canali che si alternavano a banchi o altofondi) che passavano verso il pendio a canyon sottomarini in roccia. tali canyon sono tuttora riconoscibili come elementi morfologici del pendio roccioso in indentazioni della falesia e sono impostati o sulla prosecuzione di alcune delle blande depressioni delle serre o in coincidenza di faglie ad attività sinsedimentaria. eventi di alta energia, come correnti di tempesta o di amplificazione tidale nei canali, innescavano il trasporto lungo il pendio (prevalentemente lungo i canyon) dei sedimenti carbonatici prodottisi in mare sottile (facies carbonatiche tipo molechfor) e la loro risedimentazione, nella parte medio-bassa dei canyon e al piede del pendio roccioso, in forma di accumuli sottomarini isolati fra loro (fig. 7). lungo pendio era attiva anche una factory di mare relativamente più profondo che concorreva allo sviluppo delle successioni (facies carbonatiche tipo rodhalgal). gli accumuli sedimentari lungo pendio erano però gravitativamente instabili e soggetti a frane sotto543depositi carbonatici ... fig. 6 esempio di slump nella parte alta della successione; il martello (freccia) come scala. località porto miggiano. slump in the upper part of the succession; the hammer (arrow) for scale. porto miggiano locality. fig. 7 schema paleogeografico dei sistemi di sedimentazione di scarpata e di base scarpata durante il pleistocene inferiore. palaeogeographic sketch of slope and base-of-slope sedimentation during early pleistocene. marine; la cicatrizzazione delle nicchie di distacco giustifica la presenza di discordanze interne riconosciute nelle successioni già da rossi & ungaro (1969). considerando regionalmente la geometria e la posizione delle aree di affioramento, la forma in pianta dei depositi ricorda quella di piccole conoidi sottomarine. queste risultano ubicate in corrispondenza di brusche rientranze del pendio roccioso e andrebbero considerate come una testimonianza della originale distribuzione dei sedimenti infrapleistocenici alla base del paleopendio sottomarino piuttosto che lembi residui di una originale copertura più ampia. l'accumulo lungo pendio, e non solo alla sua base, e la continuità laterale degli strati, nonostante la loro ondulazione ed il fatto di essere incisi da frane e canali effimeri, porta ad interpretare i sistemi deposizionali come apron isolati di piccole dimensioni. si trattava di sistemi deposizionali di relativa bassa profondità, fra 100 e 150 m, in buon accordo con quanto sostenuto su basi paleoecologiche da taddei ruggiero (1983; 1993) 4.2 considerazioni formazionali e neotettoniche l'interpretazione ambientale e paleogeografica qui proposta impone una revisione biostratigrafica delle successioni studiate, in quanto parte dei depositi attribuiti alla formazione di uggiano la chiesa, posti nelle blande depressioni delle serre e considerati mediopliocenico-santerniani (bossio et al., 1997), e quelli attribuiti alle calcareniti del salento, posti alla base del pendio e ritenuti di età siciliana (bossio et al., 1987a; 1987b), dovrebbero essere coevi. questa ipotesi è coerente con la distribuzione dei depositi infrapleistocenici in aree esterne a quella studiata, ed in particolare nella porzione sudoccidentale della penisola salentina, dove si può notare che gli affioramenti posti in corrispondenza dell'attuale livello del mare sono fisicamente continui con quelli posti nelle parti alte della penisola (martinis, 1970; bossio et al. 1997). in questo settore infatti le depressioni morfostrutturali presenti nella parte alta del rilievo si raccordano al mare con un pendio a gradiente costante e costituivano il substrato di sistemi di rampa carbonatica i cui prodotti sedimentari vengono attribuiti ad una unica unità formazionale (calcareniti del salento, come nell'area di tricase in: bossio et al., 1997). se in queste aree gli affioramenti infrapleistocenici affioranti a livello del mare vengono correlati fisicamente a quelli affioranti nelle parti alte della penisola (fino a quote di circa 110-120 m sul livello del mare), anche nell'area considerata nel presente lavoro, in base all'interpretazione ambientale proposta, non sussisterebbe più la necessità di distinguere dal punto di vista formazionale i depositi posti alla base del pendio da quelli affioranti nelle serre. inoltre, a livello regionale, entrambe le unità (calcareniti del salento e formazione di uggiano la chiesa), o parti di esse, sarebbero da attribuire alla formazione della calcarenite di gravina (sensu iannone & pieri, 1979), la cui età nell'area delle murge, dove fu istituita da azzaroli (1968), varia dal pliocene medio al pleistocene inferiore (ciaranfi et al., 1988), un intervallo di tempo compatibile con i depositi salentini in oggetto (si veda anche ciaranfi et al., 1993). anche il significato sedimentario dei depositi studiati sarebbe simile a quello assunto dalla formazione della calcarenite di gravina nelle murge, dove l'unità registra una significativa ingressione marina sull'avampaese apulo (iannone & pieri, 1982). la revisione sedimentologica dei depositi infrapleistocenici descritti in questo lavoro permette di affermare infatti che anche durante il siciliano l'intero pendio roccioso che raccorda le serre salentine al canale d'otranto era posto sotto il livello del mare; la posizione alla base del pendio delle successioni qui studiate, precedentemente interpretate come depositi costieri ed addebitate a fenomeni di stazionamento del mare dopo una fase di sollevamento della penisola salentina avvenuta in un intervallo di tempo compreso fra il santerniano ed il siciliano, non può essere utilizzata direttamente come indicazione di un paleolivello del mare del siciliano lungo il pendio. d'altra parte ipotizzare una fase di rapido e relativamente intenso sollevamento della penisola salentina nel pleistocene inferiore (durante l'emiliano, prima del sollevamento delle murge), seguita da una stasi e poi da un lentissimo sollevamento tuttora in atto non concorda con quanto riconosciuto nel resto dell'avampaese apulo. infatti, regionalmente, l'inizio del sollevamento dell'avampaese apulo, verosimilmente costante nel tempo, è collocato nel pleistocene medio (ciaranfi et al., 1983; doglioni et al., 1994), o nella parte alta del pleistocene inferiore al passaggio con il pleistocene medio (pieri et al., 1996; tropeano et al., 2002a). inoltre, la presenza di una serie di depositi marini terrazzati e di paleolinee di costa di età pleistocene medio-tirreniano indica un sollevamento tettonico costante in interferenza con oscillazioni eustatiche del livello del mare (ciaranfi et al., 1988). in particolare nell'area salentina vengono segnalati una serie di terrazzi marini deposizionali medio-suprapleistocenici riconosciuti a partire almeno dalla quota di 100 m sul livello del mare (fiore & palmentola, 1987) e spianate di abrasione e vecchie linee di costa dello stesso intervallo di età vengono segnalate anche a partire da quote superiori (d'alessandro et al., 1987; ciaranfi et al.., 1988; ricchetti et al., 1988). è importante sottolineare che sia le più alte spianate di abrasione che i più elevati terrazzi deposizionali giacciono a quote superiori rispetto alle quote di affioramento dei depositi qui studiati. un'ulteriore considerazione neotettonica deriva dall'analisi della distribuzione dei depositi alla base della scarpata. come evidenziato, gli affioramenti sono discontinui e ubicati dove il pendio roccioso presenta brusche rientranze. queste sono poste in corrispondenza di faglie sinsedimentarie la cui attività favoriva la presenza di zone di bypass fra le aree sommitali e la base della scarpata. le faglie tagliano una blanda soglia morfologica posta al margine superiore del pendio che ipotizziamo possa in parte corrispondere ad un originale rilievo morfologico ereditato dalle aree di fronte delle scogliere terziarie riconosciute nell'area da bosellini et al. (1999). l'attività delle faglie avrebbe favorito anche il frequente innesco di frane sottomarine lungo la scarpata. 5. conclusioni le osservazioni sedimentologiche e le considerazioni litostratigrafiche esposte in questo lavoro permettono di attribuire a sistemi deposizionali di scarpata e di base di scarpata i depositi calcarenitici infrapleistocenici affioranti nella parte bassa e alla base del pendio roccioso che ad oriente, verso il canale d'otranto, raccor544 m. tropeano et al. da la regione salentina al mare ionio. questo pendio, già riconosciuto in letteratura come un elemento fisiografico della piattaforma apula fino al messiniano, ha rappresentato localmente il margine della stessa piattaforma anche durante il pleistocene inferiore. le successioni osservate sono riferibili a sistemi carbonatici di tipo foramol che, a differenza di quanto noto in letteratura per depositi coevi affioranti sia nelle murge che nel salento, devono essere considerati non classici sistemi di mare sottile ma piccoli ed isolati sistemi tipo apron di non elevata profondità. le aree di produzione carbonatica vanno ricercate sia nelle serre salentine che lungo il pendio stesso. la nuova interpretazione ambientale di questi depositi porta a rivedere la suddivisione formazionale finora operata in questa porzione della regione salentina, in quanto non vi sarebbe più la necessità di distinguere i depositi delle serre (formazione di uggiano la chiesa) da quelli della base del pendio (calcareniti del salento). entrambi i tipi di deposito andrebbero riferiti alla formazione della calcarenite di gravina, l'unità rappresentativa del parziale annegamento mediopliocenico-infrapleistocenico dell'intero avampaese apulo dovuto alla migrazione del sistema appenninico meridionale verso oriente. infine, alcune faglie dirette e/o trascorrenti che tagliano il pendio e che mostrano attività sinsedimentaria rispetto ai depositi descritti, avrebbero interrotto sia la blanda soglia morfologica presente alla sommità del versante (ereditata dalle scogliere terziarie e che impediva di alimentare ovunque la base del pendio) sia il frequente innesco di frane sottomarine. 6. ringraziamenti si ringraziano l. simone ed e. taddei ruggiero per le profique discussioni e gli utili suggerimenti, n. ciaranfi, s. longhitano e m. schiattarella per la lettura critica del manoscritto. lavoro eseguito e pubblicato con fondi miur (cofin 2002, responsabile nazionale l. simone, responsabile locale a. laviano). lavori citati azzaroli a. (1968) calcarenite di gravina. studi illustrativi della carta geologica d'italia formazioni geologiche. servizio geologico d'italia, i, 183185. bosellini a., bosellini f.r., colalongo m.l., parente m., russo a. & vescogni a. (1999) stratigraphic architecture of the salento coast from capo d'otranto to s. maria di leuca (apulia, southern italy) . rivista ital iana di paleontologia e stratigrafia, 105(3), 397-416. bossio a., guelfi f., mazzei r., monteforti b. & salvatorini g. (1987a) studi sul neogene e quaternario della penisola salentina. v note geologiche sulla zona di castro. atti del convegno sulle conoscenze geologiche del territorio salentino, quaderni di ricerche del centro studi geotecnici e d'ingegneria, lecce, 11, 127-145. bossio a., guelfi f., mazzei r., monteforti b., salvatorini g. & varola a. (1987b) studi sul neogene e quaternario della penisola salentina. iv inquadramento bio-cronostratigrafico delle calcareniti del salento di porto miggiano s. cesarea terme. atti del convegno sulle conoscenze geologiche del territorio salentino, quaderni di ricerche del centro studi geotecnici e d'ingegneria, lecce, 11, 89-125. bossio a., mazzei r., monteforti b. & salvatorini g. (1987c) studi sul neogene e quaternario della penisola salentina. ii evoluzione paleogeografica dell'area di leuca nel contesto della dinamica mediterranea. atti del convegno sulle conoscenze geologiche del territorio salentino, quaderni di ricerche del centro studi geotecnici e d'ingegneria, lecce, 11, 31-53. bossio a., mazzei r., monteforti b. & salvatorini g. (1997) carta geologica del salento sudorientale. dip. scienze della terra, università di siena enterprise oil. budillon f. & aiello g. (1999) evoluzione pleistocenica della piattaforma continentale del salento orientale: fattori di controllo tettonici e/o eustatici. il quaternario, 12(2), 149-160. carannante g., esteban m., milliman j.d. & simone l. (1988) carbonate lithofacies as paleolatitude indicators: problems and limitations. sedimentary geology, 60, 333-346. ciaranfi n., ghisetti f., guida m., iaccarino g., lambiase s., pieri p., rapisardi l., ricchetti g., torre m., tortorici l. & vezzani l. (1983) carta neotettonica dell'italia meridionale. progetto finalizzato geodinamica cnr, 515, 62 pp. ciaranfi n., pieri p. & ricchetti g. (1988) note illustrative alla carta geologica delle murge e del salento (puglia centromeridionale). memorie della società geologica italiana, 41, 449-460. ciaranfi n., pieri p. & ricchetti g. (1993) la penisola salentina nel quadro dell'evoluzione sedimentaria e tettonica dell'avampaese apulo. xii convegno soc. paleont. it., terra d'otranto, guida alle escursioni, 9-20. d'alessandro a., loiacono f. & ricchetti g. (1987) note illustrative alla carta geomorfica del salento meridionale (f.525 "gallipoli", 526 "nardò", 527 "otranto", 536 "ugento" e 537 "capo s.maria di leuca"). atti del convegno sulle conoscenze geologiche del territorio salentino, quaderni di ricerche del centro studi geotecnici e d'ingegneria, lecce, 11, 207-222. d'alessandro a., massari f., davaud e. & ghibaudo g. (2004) pliocene-pleistocene sequences bounded by subaerial unconformities within foramol ramp calcarenites and mixed deposits (salento, se italy). sedimentary geology, 166, 89-144. doglioni c., mongelli f. & pieri p. (1994) the puglia uplift (se-italy): an anomaly in the foreland of the apenninic subduction due to buckling of a thick continental litosphere. tectonics 13(5), 13091321. festa v. (2003) cretaceous structural features of the murge area (apulian foreland, southern italy). eclogae geol. helv., 96, 11-22. fiore s. & palmentola g. (1987) le sabbie a brachiopodi del salento leccese: dati e problemi. atti del convegno sulle conoscenze geologiche del terri545depositi carbonatici ... torio salentino, quaderni di ricerche del centro studi geotecnici e d'ingegneria, lecce, 11, 243257. iannone a. & pieri p. (1979) considerazioni critiche sui "tufi calcarei" delle murge. nuovi dati litostratigrafici e paleoambientali. geografia fisica e dinamica quaternaria, 2, 173-186. iannone a. & pieri p. (1982) caratteri neotettonici delle murge. geologia applicata e idrogeologia, xviii (ii), 147-159. martinis b. (1962) lineamenti strutturali della parte meridionale della penisola salentina. geologica romana, 1, 11-23. martinis b. (1967) note geologiche sui dintorni di casarano e castro (lecce). riv. it. paleontologia, 73(4), 1297-1380. martinis b. (1970) note il lustrative della carta geologica d'italia, f°223 "capo s. maria di leuca". servizio geologico d'italia, 65 pp. moretti m. (1997) le strutture sedimentarie deformative. studio delle modalità di deformazione e dell’origine attraverso esempi fossili e modellizzazioni in laboratorio. tesi di dottorato inedita, università di bari, 232 pp. palmentola g. (1987) lineamenti geologici e morfologici del salento leccese. atti del convegno sulle conoscenze geologiche del territorio salentino, quaderni di ricerche del centro studi geotecnici e d'ingegneria, lecce, 11, 7-23 palmentola g. & vignola n. (1980) dati di neotettonica sulla penisola salentina. prog. fin. geodinamica cnr, 5, 173-202. pieri p. (1975) geologia della città di bari. memorie della società geologica italiana, 14, 379-407. pieri p. (1980) principali caratteri geologici e morfologici delle murge. murgia sotterranea, bollettino gruppo speleo martinense, martina franca, 2, 13-19. pieri p., festa v., moretti m. & tropeano m. (1997) quaternary tectonic activity of the murge area (apulian foreland southern italy). annali di geofisica, xl (5), 13951404. pieri p., sabato l. & tropeano m. (1996) significato geodinamico dei caratteri deposizionali e strutturali della fossa bradanica nel pleistocene . memorie della società geologica italiana, 51, 501-515. pomar l. & tropeano m. (2001) the calcarenite di gravina formation in matera (southern italy): new insights for coarse-grained, large-scale, crossbedded bodies encased in offshore deposits. aapg bull., 85, 661-689. ricchetti g., ciaranfi n., luperto sinni e., mongelli f. & pieri p. (1988) geodinamica ed evoluzione sedimentaria e tettonica dell'avampaese apulo. memorie della società geologica italiana, 41, 5782. rossi d. & ungaro s. (1969) i sedimenti quaternari di porto miggiano (penisola salentina). annali università di ferrara, sez. ix, 4/16, 249-260. sabato l. (1996) delta calcareo terrazzato nella calcarenite di gravina (pleistocene inferiore). minervino, murge nord-occidentali. memorie della società geologica italiana, 51, 517-526. taddei ruggiero e. (1983) paleoecologia e biostratigrafia delle calcareniti a brachiopodi di castro (lecce). boll. soc. natur. napoli, 92, 347-413. taddei ruggiero e. (1993) argyrotheca ageriana sp. nov. (brachiopoda): paleoecology and shell ultrastructure. palaeogeography, palaeoclimatology, palaeoecology, 100, 217-227. taddei ruggiero e. (1994) neogene salento brachiopod palaeocommunities. boll. soc. paleont. it., 33, 197-213. tozzi m. (1993) assetto tettonico dell'avampaese apulo meridionale (murge meridionali salento) sulla base dei dati strutturali. geologica romana, 29, 95-11. tropeano m. (1994a). caratteri deposizionali della calcarenite di gravina (pliocene superiore pleistocene inferiore) sul bordo orientale della fossa bradanica nell'area di matera. in: guida alle escursioni del 77° congresso della società geologica italiana bari. quaderni della biblioteca provinciale di matera, 15, 67-86. tropeano m. (1994b) sistemi costieri carbonatici nella calcarenite di gravina (pliocene superiore pleistocene inferiore) nell'area delle murge e della fossa bradanica. tesi di dottorato di ricerca in scienze della terra, università di bari, 169 pp. tropeano m., moretti m., pieri p. & sabato l. (2000) morphostructural constraints on distribution of lower pleistocene coarse-grained base-ofslope/submarine-fan carbonates along the eastern salento escarpment (puglia, southern italy). convegno: millennium flux: sediment supply to basins, southampton, uk, abstract volume, 47. tropeano m., moretti m., pieri p. & sabato l. (2002b) lower pleistocene slope carbonates along the eastern salento escarpment (puglia, southern italy). 16th ias congress, johannesburg, south africa, abstract volume, 380. tropeano m. & sabato l. (2000) response of pliopleistocene mixed bioclastic-lithoclastic temperate-water carbonate systems to forced regression: the calcarenite di gravina formation, puglia, se italy. in: "sedimentary responses to forced regression" (d. hunt & r.l. gawthorpe, eds.), geol. soc. london, sp. publ. 172, 217-243. tropeano m., sabato l. & pieri p. (2002a) filling and cannibalization of a foredeep: the bradanic trough (southern italy). in "sediment flux to basins: causes, controls and consequences" (s.j. jones & l.e. frostick, eds.), geol. soc. london, sp. publ. 191, 55-79. zezza f. (1983) le calcareniti calabriane e tirreniane di porto miggiano sul canale d'otranto. geol. appl. idrogeol., xviii, 33-44. 546 m. tropeano et al. ms. ricevuto il 21 maggio 2004 testo definitivo ricevuto il 15 dicembre 2004 ms. received: may 21, 2004 final text received: december 15, 2004 untitled recent morphological changes of the river panaro (northern italy) doriano castaldini* & alessandro ghinoi* *dipartimento di scienze della terra, università degli studi di modena e reggio emilia, largo s. eufemia 19, i-41100 modena, italy e-mail: doriano.castaldini@unimore.it abstract: castaldini d. & ghinoi a., recent morphological changes of the river panaro (northern italy) (it issn 0394-3356, 2008). this paper describes the morphological changes of the river panaro from the 19t h century to date and provides the relationships between human activity and stream geomorphology. the studies were carried out using historical documents and maps, aerial and satellite imagery taken on various dates, digital treatment of maps and orthophotographs and field surveys. the river panaro has a catchment basin of 1,784 km2 and collects waters from the central section of the northern apennines. it starts from the confluence of the scoltenna and leo torrents and flows down through modena apennines for some 63 km. it then makes its way across the po plain for 85 km until it joins the river po. in the po plain it flows across two distinct sectors with different morphological characteristics: in the upper sector the river runs deep in the alluvial plain, whereas in the mid-lower part it is elevated above the level of the plain, contained within artificial embankments. in the panaro valley, from the 1930s to the 1950s, the river showed a braided pattern which occupied almost the entire flat valley floor. important changes occurred later, due to the downcutting and narrowing of the active channel, which have continued until the present day. in the upper part of the plain., the river occupied a large depression with a braided riverbed at the beginning of the 19th century. in the following periods there was an increase of human interventions along the river (construction of embankments, walls and groynes), in order to reclaim surrounding areas from flooding and turn highwater beds into farming land. this led to narrowing in several stretches of the riverbed, although it still maintained a braided pattern until the 1930s. subsequently, after the 1950s, the braided pattern became canalised and deepened and the shape of the longitudinal profile changed from a hyperbola-type curve to a step-type one. the channel changes in the apennines and in the upper part of the plain were mainly due to gravel excavation along the riverbed. quarrying activities stopped after a law was passed in the early 1980s and, at the same time, fluvial barrages were constructed. on the whole, these hydraulic works reduced the bed load, increasing water erosion power downstream. as a result, the deepening process has continued and a new terrace level has formed in the past 30 years. channel adjustments have led to the change from a braided channel pattern to a transitional one. in the mid-lower part of the plain, the river length has been reduced by 10-11 km (which corresponds to about 13% of its length in this plain sector) by artificial meander cut-offs carried out since the 19th century to reduce flood hazard. in this way, along long stretches of its course, the river panaro has assumed the aspect of an artificial watercourse. since the cut-offs did not adequately reduce flood hazard, “flow regulation systems” were constructed in the area east of modena. it can therefore be stated that the morphology and evolution trend of the river panaro have been conditioned by direct and indirect human activities over the past two centuries, especially after the 1950s, and that its evolution is similar to what has been recorded in other italian rivers riassunto: castaldini d. & ghinoi a., recenti cambiamenti morfologici del fiume panaro (italia settentrionale) (it issn 0394-3356, 2008). il presente articolo descrive i cambiamenti morfologici del fiume panaro a partire dal 19° secolo e illustra le relazioni tra l'attività antropica e la morfologia fluviale. lo studio è stato realizzato analizzando documenti storici, carte, fotoaeree e immagini satellitari di vari periodi, tramite gis, ed eseguendo rilevamenti sul terreno. il f. panaro, che ha un bacino di 1.784 km2, raccoglie le acque dal settore centrale dell'appennino settentrionale e le convoglia nel f. po dopo aver attraversato l'appennino modenese, dove nasce dalla confluenza dei torrenti leo e scoltenna, per 63 km e la pianura padana per 85 km. nella pianura padana il f. panaro si sviluppa in due settori con diverse caratteristiche morfologiche: nel settore di alta pianura scorre incassato mentre nel settore di media-bassa pianura scorre pensile tra argini artificiali. nel tratto vallivo, dagli anni '30 agli anni '50 del secolo scorso, il fiume denotava un alveo a canali intrecciati che occupava quasi l'intero fondovalle. importanti cambiamenti sono intervenuti successivamente in seguito a processi di approfondimento e restringimento dell'alveo che sono continuati sino ad oggi. nel settore di alta pianura, all'inizio del 19° secolo, il fiume occupava una larga depressione con un tracciato a canali anastomizzati. a partire dalla fine di questo secolo, l'aumento degli interventi antropici lungo il fiume (costruzione di argini, muri e pennelli) realizzati per proteggere il territorio dalle esondazioni ed acquisire terreni per l'agricoltura, ha condotto ad un restringimento dell'alveo sebbene abbia mantenuto un tracciato a canali intrecciati sino agli anni '30. successivamente agli anni '50 l'alveo si è approfondito e canalizzato; il profilo longitudinale è passato dalla classica curva a forma di iperbole a quella a gradini. i cambiamenti morfologici dell'alveo del f. panaro sia nel tratto vallivo sia nel tratto di alta pianura sono dovuti principalmente all'attività estrattiva lungo l'alveo, cessata per legge a partire dai primi anni '80, e alla relativa costruzione di briglie. le briglie hanno ridotto il trasporto solido incrementando in tal modo l'energia della corrente nei tratti a valle di queste strutture. il risultato è stato che il processo di approfondimento d'alveo è continuato e un nuovo terrazzo si è formato nell'ultima trentina d'anni. l'evoluzione del fiume ha portato ad un cambiamento d'alveo da una morfologia a canali intrecciati ad una transizionale. nel settore di media e bassa pianura, la lunghezza del fiume è stata ridotta di circa 10-11 km (che corrispondono a circa il 13% del percorso in questo settore) in seguito a tagli di meandri realizzati sin dal 19° secolo per ridurre il pericolo di esondazioni; in questo modo il f. panaro ha assunto in lunghi tratti l'aspetto di corso d'acqua artificiale. poiché i tagli di meandro non hanno ridotto tale pericolo, come testimoniato dalle alluvioni verificatesi dopo la loro realizzazione, ad est di modena sono state costruite delle casse di espansione. in definitiva si può affermare che la morfologia del f. panaro e la sua evoluzione sono stati condizionati direttamente ed indirettamente da interventi antropici succedutisi negli ultimi secoli, ed in particolare a partire dagli anni '50, e che la sua evoluzione è simile a quella riscontrata in altri fiumi italiani. keywords: morphological changes, anthropogenic interventions, river panaro, northern apennines, po plain. parole chiave: cambiamenti morfologici, interventi antropici, fiume panaro, appennino settentrionale, pianura padana. il quaternario italian journal of quaternary sciences 21(1b), 2008 267-278 268 d. castaldini & a. ghinoi 1. introduction it is well known from many studies that in the past few centuries human activity has influenced channel changes and stream morphology all over the world (see le o p o l d, 1973; pe t t s, 1979; hi c k i n, 1983; gr e g o r y, 1987; la j c z a k, 1995; ló c z y, 1997; li e b a u l t & pi e g a y, 2002; herget et al. 2007). as regards italy, channel changes along the river po (the longest watercourse in italy, 652 km), occurring during the 20t h century, are, at least in part, a consequence of river engineering (see govi & turitto, 1993; castaldini & piacente, 1995). the same can be said for the streams enza (pe r e g o, 1988), tidone (fa r a v e l l i & messina, 1997), trebbia and vara (rinaldi et al., 2005) in the northern apennines and rivers dora riparia (franceschetti et al., 1990), piave and brenta (surian, 1999; surian et al., 2005) in the alps. a general outline of the main channel adjustments that have occurred in 27 italian rivers during the past 100 years was given by surian & rinaldi (2003). this paper illustrates the morphological changes of the river panaro (fig. 1) from the 19th century to date and discusses the relationships between human activity and stream morphology. as regards the evolution of the river in previous centuries, see pellegrini m. (1969) and castaldini (1989). studies concerning the recent evolution of the r. panaro go back to 30-40 years ago. in detail, pellegrini & rossi (1967) notice that after a period of flooding or equilibrium, the stretch of the r. panaro, from the lower mountain area as far as the city of modena, has undergone an erosional phase, starting around 1950, which has caused a lowering of the riverbed. quarrying activities within the riverbed have been identified as the main cause of this process, since the authors have noted how the location of quarries correspond to the river stretches subject to erosion; the onset of this process also coincides with gravel and sand extraction on a wider scale. in addition, pe l l e g r i n i m. (1969) notices that some morphological features of the r. panaro, as well as of the nearby r. secchia, tend to have changed: riverbed narrowing, stretching up of the river courses and rejuvenation of the equilibrium profile. these changes are mainly ascribed to artificial causes, such as meander cutoffs and excavation of building materials from riverbeds. pe l l e g r i n i m. et al. (1979) describe the evolution which has taken place in the past decades in the tributaries of the river po in the emilia region. these authors show that the r. panaro is certainly one of the rivers which have undergone major changes due to anthropogenic activities: intense gravel excavation from the riverbed up to the mid-mountain area, subtraction of vast highwater areas for farming practices, construction of embankments in the upper plain area etc. after these studies, though, no significant investigations have been carried out on the evolution of the r. panaro. yet, the simple comparison between the actual morphological situation and the regional technical map (ctr) of the emil ia-romagna region, at a 1:10,000 scale (which is commonly used a as topographic basis for territorial studies) clearly shows that hydrography has undergone remarkable changes also in the past 30 years. in fact, the general representation of morphology, hydrography and vegetation in the ctr second edition corresponds to the situation between 1973 and 1979. therefore, on the one hand this paper aims to be an updating of previous investigations and, on the other hand, it reconstructs the morphological changes of the r. panaro by means of a detailed examination of cartographic and remote sensing documents introduced into a gis. in addition, this research may be considered as a contribution to the outline of channel adjustments in italian rivers, since the river panaro was not considered in the list by surian & rinaldi (2003). 2. geographical, geomorphological and geological setting the river panaro has a catchment basin of 1,784 km2 and collects waters from the central section of the northern apennines. it originates in the mid-modena apennines, at the confluence of the streams scoltenna and leo (altitude of about 320 m a.s.l.) and flows down through modena apennines for some 63 km (fig. 1). after flowing along a flat-bottomed valley, it reaches the po plain at the foot of the apennine chain near vignola (altitude of 110 to 100 m a.s.l.). in the plain, the river panaro flows across two distinct sectors with different morphological characteristics: in the upper sector of the plain, upstream of modena, the river runs deep in the alluvial plain, whereas in the mid-lower part of the plain, it flows elevated over the plain, contained within artificial embankments, as far as the confluence with the river po (altitude of about 10 m a.s.l.). the study area is situated in a temperate climatic zone (type “cfa” of köppen's classification). from the pluviometric viewpoint, it has annual average precipitation ranging from about 1200 mm in the mountain sector to some 700 mm in the plain sector, with seasonal peaks concentrated in autumn and spring, and minimum values in summer (bo c c o l a r i et al. , 1998). therefore, the hydrological regime of the r. panaro is characterised by two very similar peaks in the spring (march-april) and autumn (november), and a minimum in summer (august). the main geological units forming the modena apennines are as follows (bettelli et al. 1989): 1) tuscan units, made up of tertiary deep-water turbidites, continuously cropping out along the apennine chain axis. 2) ligurian units made up of deep-sea sediments including jurassic ophiolites followed by thick sequences of cretaceous to eocene calcareous or terrigenous turbidites. 3) the mainly terrigenous epi-ligurian sequences of the middle eocene to the late messinian, unconformably resting on the previously deformed ligurian units. the epi-ligurian sequences and the ligurian units are exposed in the mid-apennines. 4) the belt of plio-quaternary marine terrigenous deposits unconformably overlying the ligurian units and the epi-ligurian sequences cropping out at the apennine margin and dipping under the alluvial deposits of the po plain. the modena plain lies at the foot of the apennine chain which is still in full evolution. at the apennine margin the streams reaching the plain have built up alluvial fans which extend to the north. since they overlap each other, they can be regarded as part of a continuous belt of coarse alluvial deposits spreading all along the apennine foot. remains of old fans appear at the foot of the apennine chain, and are characterised by paleosols and pleistocene aeolian covers (loess), terraced upstream and buried downstream by the holocene alluvia. many ridges formed by the local evolution of ancient streams depart from the foot of the fans, their patterns revealing the recent migration of these rivers. north of the city of modena, depressed areas are located in between the fluvial ridges. the superficial alluvial deposits in the study area were mainly formed during the holocene; their particle-size distribution ranges from gravel to clay (ga s p e r i et al. , 1989; ca s t i g l i o n i et al., 1997; ca s t i g l i o n i & pe l l e g r i n i g.b., 2001). the plain/apennine boundary is purely morpholo269recent morphological changes ... gical as the apennine structures continue towards nne as far as the river po, buried under the quaternary continental sediments. fault or fold displacements have also involved these deposits (pi e r i & gr o p p i, 1981; di dio, 1998). 3. methods and data sources the study was carried out according to the traditional methods used in geomorphology (bibliographic research; research on historical documents and maps, morphological analysis by means of interpretation of aerial photographs and satellite imagery taken in various periods, morphological field-survey of the present-day river course) as well as methods concerning the digital treatment carried out on maps, aerial photographs and satellite images. the use of digitisers and image processing in geomorphology and especially in fluvial process mapping has been illustrated in several works (see le y s & we r r i t t y, 1999; we s t a w a y et al., 2000; wr i g h t et al. , 2 0 0 0 ) . the technique consists in the elaboration of maps of fluvial features (morphological maps), starting from topographic maps, aerial photographs and satellite images. as the river panaro course has been shown accurately on maps only since the 19t h century, this study has focused on the evolution of the last two centuries. the documents listed in tab. 1 have been considered. the topographic maps of the study area, corresponding to different years, have been rasterised in the first phase. due to their early date of publication, some maps did not present a georeferenced base; it has therefore not been possible to introduce them into a gis. subsequently, they were scanned and georeferenced within the arcgis gis. in this way it was possible to measure, with acceptable approximation, the changes taking place in the riverbeds. as regards aerial photographs and satellite images, the method used consisted in interpretation and fig. 1 location of the study area. legend: 1) basin of the river panaro; 2) stretches of the river panaro shown as examples near casona, spilamberto and s. ambrogio; 3) sectors of the river panaro (as: apennine sector; up: upper part of the plain; mlp: mid-lower part of the plain). ubicazione dell'area di studio. legenda: 1) bacino idrografico del fiume panaro; 2) tratti del f. panaro illustrati come esempi presso casona, spilamberto e s. ambrogio; 3) settori del f. panaro (as: settore apenninico; up: alta pianura ; mlp: medio-bassa pianura). digital treatment using photogrammetry techniques, which afterwards allowed the georeference of geomorphological information. a field-survey of the present-day course has been carried out in order to update the features of the stream through geomorphological mapping. 4. morphological changes of the river panaro since the 19th century in this part the morphological changes of the river panaro since the 19th century to date are illustrated in detail. they were reconstructed on the basis of the documents listed in table 1. this research and its conclusions were supported by analyses carried out on the entire course of the river panaro. the description will be made in chronological sequence, making a division between three sectors: apennine sector (as); upper part of the plain (up); mid-lower part of the plain (mlp). in particular, this paper will focus on the illustration of the channel changes occurring on the most significant partial stretches: casona in the as sector, spilamberto in the up sector and st. ambrogio in the mlp sector (fig. 1). 4.1 channel changes in the apennine sector in the apennine sector the comparison between topographic maps, aerial and satellite imagery and topographic elements currently visible in the field has highlighted substantial changes along the river panaro valley from the first half of the 20t h century (the oldest map examined for this sector are the 1933-35 igm maps). in particular, in the 1930s the river panaro bed showed a braided pattern which occupied almost the entire flat valley bottom; terraces (of small extent) were present only locally, and no significant human dwellings existed (fig. 2a). a very similar situation can be found in the 1954-1955 aerial photographs. important changes are evident in more recent documents. in fact, in the 1970s the river abandons its braided pattern and the river channel gets deeper and narrower, as testified by the formation of side-valley terraces used for farming and human settlements (fig. 2b). some check dams can be found along the river course. the downcutting and narrowing of the active channel has continued until the present day. in detail, besides considerable growth of human activities on the river terraces, the river has undercut its bed forming a new terrace (fig. 2c). this is about 1 m higher than the riverbed and reaches several meters at the apennine margin, just downstream of check dams where the bedrock crops out. this terrace, characterized by dense vegetation, is already visible and developed in the 1988/89 aerial photographs, while it is not present in those of the 1970s. therefore, its formation is likely to date back to the end of the seventies and the beginning of the 1980s. 4.2 upper part of the plain in the first half of the 19t h century the r. panaro occupied a depression in the alluvial plain with a vast extension of deposits and showed a braided pattern (fig. 3a). it is not possible to evaluate the depth between the alluvial plain and the river channels because of lack of information on altimetry in the ca r a n d i n i (1821-1828) maps. the first modest excavations of gravel from the riverbed go back to that period (lombardini, 1865). at the end of the 19t h century (fig. 3b), the river flowed within a depression which, as assessed on the basis of the few altitude points shown, was around 1-2 m lower than the surrounding ground surface. the watercourse still showed braided channels. of course, the trend of the low-water channels had undergone changes compared with the previous period. in this period, the first systematic human interventions along the river (embankments, walls and groynes) were carried out in order to reclaim the surrounding areas from flooding and turn highwater beds into farming land. significant channel changes were recorded in the first half of the 20th century (fig. 3c and 3d), caused by further construction of walls and embankments. this had two consequences: the first was a narrowing of the riverbed (fig. 3d); the second was a result of the first and consisted in a huge aggradation process in the active channel (fig. 4a). nevertheless, the r. panaro maintained its braided pattern. other important human works carried out in this period were the excavation of small gravel pits at the sides of the river. the analysis of the channel changes for the second half of the 20t h century is much better docu270 table 1 documents considered in this study. igm: italian military geographic institute; gai: aerial italian group; ctr: regional technical maps (ctr) of emilia-romagna region; rer: emilia-romagna region; documenti utilizzati nel presente studio: igm: istituto geografico militare italiano; gai: gruppo aereo italiano; ctr: carta tecnica della regione emilia -romagna; rer: regione emilia romagna. type of document age scale/resolution note carandini maps 1821 1828 1:50,000 colour igm maps 1881 1894 1:25,000 black & white igm maps 1911 1914 1:25,000 black & white igm maps 1933 1935 1:25,000 black & white gai aerial photographs 1954 1955 1:33,000 black & white rer aerial photographs 1973 1:15,000 black & white ctr maps 1973 1978 1:10,000 black & white rer aerial photographs 1978 1:20,000 colour ctr maps 1985 1986 1:10,000 black & white volo italia aerial photographs 1988 1989 1:70,000 black & white volo italia 2000 orthophotographs 2000 1 m colour quick bird satellite orthophotographs 2003 0.6 m black & white d. castaldini & a. ghinoi 271recent morphological changes ... mented thanks to ctr maps, new igm maps, aerial photographs, satellite imagery and field surveys. they show important human interventions along the river which have influenced stream morphology (fig. 3e). in this period, quarrying activities and fluvial barrages influenced channel changes. these factors produced the same effects on the river: deepening and canalisation of the riverbed. after the 1950s, the considerable expansion of urban and industrial areas required an increase of building materials and therefore of quarrying activities; these activities were concentrated inside and in proximity of the riverbed. the first effect of excavations inside the riverbed was the removal of the superficial coarse alluvial deposits which brought to the surface alluvial material of different particle size that was easily eroded by the stream. this resulted in increased deepening of the riverbeds and a new channel morphology, which undermi272 d. castaldini & a. ghinoi fig. 3 morphological sketch of the r. panaro in the upper part of the plain near spilamberto. legend: a) first half of 19th century (elaborated from carandini, 1821-28 maps); b) second half of 19th century (from the 1884 igm map); c) 1911 and d) 1935 (from the 1911 and 1935 igm maps); e) second half of 20th century (from the 1978 ctr maps and aerial photographs); f) present situation (from the 2003 quick-bird satellite imagery and field surveys); 1) river channel; 2) fluvial scarp; 3) artificial scarp; 4) artificial embankment; 5) quarrying area (a: active; b: abandoned); 6) check dam; 7) bridge; 8) built-up area. carta geomorfologica schematica del f. panaro nell'alta pianura presso spilamberto. legenda: a) prima metà del 19° secolo (elaborata sulla base della cartografia carandini, 1821-28; b) seconda metà del 19° secolo (dalla cartografia igm del 1884; c) 1911 e d)1935 (dalla relativa cartografia igm); e) prima metà del 20° secolo (dalla ctr e da fotoaeree del 1978); f) attuale (dalle immagini del satellite quick-bird del 2003 e da rilevamenti sul terreno); 1) alveo fluviale; 2) scarpata fluviale; 3) scarpata artificiale; 4) argine artificiale; 5) area di cava (a: attiva; b: abbandonata); 6) briglia; 7) ponte; 8) area antropizzata. ned or damaged bridge piers at marano, vignola, spilamberto and s. donnino (motorway bridge). deepening of over 6 m was recorded near spilamberto bridge (fig. 4b). in order to overcome these unforeseen problems, various check dams were constructed. however, these hydraulic structures have stopped riverbed deepening only locally. in fact, acting as local base levels, these barrages have favoured aggradation processes and the re-deposition of the alluvial cover only in the upstream tracts (fig. 4c). on the whole, check dams have reduced bed load, thus increasing water erosion power downstream. the result was that deepening processes have continued in the stretches downstream of the barrages. riverbed deepening also introduced an important modification. in fact, the reduction of lateral movements caused by downcutting produced a change in morphology from a braided to a wandering pattern. the deepening process was particularly marked in the 1970s. since the 1980s the river has been flowing within a single riverbed (or with very few channels) and the process of downcutting has continued accompanied by a marked narrowing of the active channel (fig. 3f). the deepening, together with the construction of check dams, has also modified the longitudinal profile of the riverbed from a hyperbola-type curve to a step-type one (fig. 5). quarrying activities, located at the sides of the river, have irreversibly altered the natural morphological features of the depression and have dismembered or destroyed the hydraulic defence works constructed since the end of the 19th century. in this way the boundary depression has changed from a “natural” type to an “artificial” type. in the present day, the r. panaro shows a transitional pattern, mainly confined within a single flow channel still characterised by intense downcutting. in order to solve the impacts of quarrying activities on the landscape, some measures have been taken by the province administration board in recent decades. within the framework of a strategy for environmental protection and improvement, local administrations have concentrated their efforts on reclaiming quarrying areas. in this way many of them have become nature protection areas where industrial activities are no longer permitted (provincia di modena, 2003). in short, especially after the 1950s, the river panaro switched from a braided riverbed to a canalised course subject to considerable deepening and narrowing. this trend has lasted up to the present. for instance, near spilamberto, a deepening of 8-9 m and a narrowing of about 390 m (56%) of channel width has been recorded in the past 120 years (fig. 6). 4.3 mid-lower part of the plain in this part of the plain, in the first half of the 19th century, the r. panaro showed several, well developed meanders, with a bend radius of up to 200 m; it also showed alternate channel width: from 80 m (slightly winding stretches) up to 500 m wide (with large highwater beds). in this sector the river flowed within artificial embankments which were “uplifted and strengthened” during this period (lo m b a r d i n i, 1865); this means that floods were a hydrological hazard. at the end of the 19th century, the r. panaro still showed several meanders, even if it was shortened at the beginning of 1889 by about 5.5 km between finale emilia and bondeno. moreover, some meanders appear to have been straightened near its outlet, with a reduction of the watercourse length of about 2 km. in this way the r. panaro was shortened by about 7-8 km. the meander cutoffs were mainly carried out in order to reduce the highwater level along the straightened reach, where the sinuous course caused a slowdown of the flow, and therefore to mitigate flood hazard. in fact the river panaro, in the 19t h c e n t u r y , flooded several times (in 1812, 1813, 1842, 1852, 1862, 1868, 1872 and 1887) (ca s t a l d i n i, 2006). these interventions proved ineffective, as shown by floods which later occurred: after the artificial cutoffs and before the end of the century, the r. panaro flooded again in october 1889 and october 1897. of course, meander cutoffs did not eliminate flood hazard but only transfer273 fig. 4 the r. panaro channel at the bridge of spilamberto: a) in the 1930 circa (by pellegrini m. et al., 1979); b) in the 1967 (by pellegrini m. & rossi, 1967); c) in the 2004 (photo by d. castaldini). l'alveo del f. panaro presso il ponte di spilamberto. a) nel 1930 circa (da pellegrini m. et al. 1979); b) nel 1967 (cfr. by pellegrinii m. & rossi, 1967); c) nel 2004 (foto d. castaldini). a) 1930 b) 1967 c) 2004 recent morphological changes ... red the problem to the river reach downstream of the cutoffs. in the first half of the 20t h century, the course of the r. panaro remained practically identical to the course of the 19th century. in this century the r. panaro flooded several times in the area of modena: in 1928, 1939, 1949, 1951, 1952, 1956, 1960, 1964, 1966, 1969, 1972 and 1973 (ca s t a l d i n i, 2006). in order to reduce flood hazard, the latest meanders cutoff was made in the early 1970s when the r. panaro was shortened by four meanders (a length of about 3 km) near st. ambrogio, east of modena (fig. 7 and 8). but also this work proved ineffective, as testified by the flood which struck the territory of finale emilia in november 1982. therefore, a “flow-regulation system” was planned and constructed to the east of modena, at the boundary between the upper and middle sectors of the plain, adjacent to the river course, in order to better control hydrogeological hazard (castaldini & pellegrini m., 1989). the flow regulation system is located where r. panaro flows inside its natural depression, that is approximately 2 km wide, previously used as quarrying areas (fig. 8). this structure, operating since 1985, consists principally of a regulating dam built across the riverbed and a storage basin (which allows the store of about 24 million m3 of water) almost completely confined by embankments about 6 km long and 4 to 5 m high. during lowwater periods, the water is discharged through mouths located in the regulating dam at the same level as the riverbed. during highwater events, no more than a limited amount could be discharged through the dam's mouths. excess water is stored upstream of the regulating dam, producing an increase in water level and regulating the flow downstream. the flow regulation system was completed in november 1999. the most 274 d. castaldini & a. ghinoi fig. 5 modification of the longitudinal profile of the r. panaro in the upper part of the plain (between the vignola bridge and s. ambrogio bridge). legend: 1) longitudinal profile of the plain level in 1973-1978 (elaborated from the ctr maps at a 1:10,000 scale); 2) longitudinal profile of the r. panaro channel in the 1960s (from pellegrini m. & rossi,i, 1967); 3) longitudinal profile of the r. panaro channel in 1978 (elaborated from the ctr maps at 1:10,000 scale); 4) check dam: 5) bedrock outcrop. the vertical scale is exaggerated with respect to the longitudinal scale. modificazione del profilo longitudinale del fiume panaro tra vignola e il ponte di sant'ambrogio sulla via emilia. legenda: 1) profilo longitudinale del livello della pianura nel 1973-1978 (elaborato dalle ctr a scala 1:10.000); 2) profilo longitudinale dell'alveo del panaro negli anni '60 (da pellegrini m. & rossi,, 1967); 3) profilo longitudinale dell'alveo del panaro nel 1973-1978 (elaborato dalle ctr a scala 1:10.000); 4) briglia: 5) affioramento del substrato. la scala delle altezze è esagerata rispetto a quella delle lunghezze. fig. 6 trends of the channel width in the stretch of the r. panaro in the upper part of the plain near spilamberto since the end of 19th century (the stretch is about 4 km long). channel width was measured on maps, aerial and satellite images as indicated in tab. 1. variazioni della larghezza dell'alveo del f. panaro nell'alta pianura presso spilamberto dalla fine del 19° secolo (il tratto d'alveo è lungo circa 4 km). la larghezza è stata misurata su documenti cartografici, fotoaeree e immagini satellitari indicati in tab. 1. important function of this large hydraulic work is to reduce flood peaks; that is, they intervene on a very limited water capacity but with a high hydrometric level. similar structures were also built on other watercourses of the emilia-romagna region, such as the secchia river to the west of modena. the above mentioned deepening processes of the upper part of the plain have affected also the stretches north of modena, where the r. panaro flows as an elevated river within artificial embankments. moreover fluvial erosion takes place in correspondence with concave banks, causing their undermining which in some places leads to bank retreat and soil slips. in order to curb bank erosion, rockfill protection structures have been set up along many reaches. in several reaches both the banks of the r. panaro are covered by thick riverine vegetation which reduces the water flow section with an increase in hydraulic hazard. 5. conclusions the morphological changes of the r. panaro from the 19th century to date were reconstructed on the basis of reliable and detailed maps, aerial and satellite imagery and field surveys. the morphological changes were examined in three distinct sectors, which are the flat bottom valley in the apennine sector, the upper part of the plain, where the river cuts through the alluvial plain, and the mid-lower plain sector, where it flows as an elevated water course within artificial embankments. in the 19th century all anthropogenic interventions described by ca s t i g l i o n i & pe l l e g r i n i g . b . (2001) are furthermore accentuated in the po plain. a new phenomenon, consisting of ever increasing highwater events takes place starting from 1705, as recorded by instrumental measurements: each highwater event tends to overcome the maximum hydrometric levels of the previous one (for r. panaro, see lo m b a r d i n i, 1865). floods are disastrous and the economies of pre-unity italian states and subsequently of the newly founded kingdom of italy were at the end of their resources. the establishment of land reclamation agencies in this country is the consequence of this situation. among the hydraulic engineers of that period a very heated discussion started about the causes of this phenomenon. according to lo m b a r d i n i ( 1 8 6 5 ) , the causes were to be found exclusively in deforestation. other experts, though, noticed that also the riverbed bottom altitudes were progressively increasing. all the rivers' alluvial deposits, which will be removed in the second half of the 20th century, can be ascribed to the end of 16th century-first half of 20th century period. the climatic meaning of this considerable depositional phase is probably related to the little ice age (see ferrari & pellegrini m., 2007 and annexed bibliography). research aimed to show how the deepening process of the r. panaro, which became very evident in the 1960s, is an alarming phenomenon which has undermined or damaged bridges, piers and weirs (pellegrini m. & rossi, 1967; pellegrini m., 1969; pellegrini m. et al., 1979) and has continued up to recent decades. in fact, it has been demonstrated that a new terrace level was formed in the past 30 years, both in the apennine sector and in the upper part of the plain. pe l l e g r i n i m. & ro s s i (1967) believed that the tendency of watercourses to deepen their riverbeds might have a positive aspect since, by increasing the river section, it also reduced the dangers of flooding even in the stretch where the river is elevated over the surrounding plain. subsequently, though, pe l l e g r i n i m. et al. (1979) showed that the new type of riverbed had caused a change in water runoff dynamics (decrease of highwater events with tendential increase of hydrometric levels but unchanged integral flow rate). according to these authors, this new hydraulic regime, which was a direct consequence of the altered morphological conditions of the river, should be considered the cause of the frequent inundations occurring in the 1960s and 1970s near modena (1960, 1964, 1966, 1969, 1972 and 1973). 275 fig. 7 aerial photograph of the r. panaro near s. ambrogio, east of modena. it flows from the left (south) to the right (north); meander cut-offs carried out in the early 1970s are evident (photo by d. castaldini). foto dall'aereo del f. panaro presso s. ambrogio, a est di modena. il fiume scorre da sinistra (sud) verso destra (nord); risultano evidenti i tagli di meandro effettuati agli inizi degli anni '70 (foto d. castaldini). recent morphological changes ... in order to overcome the downcutting process, various check dams were constructed along the river, but this solution proved ineffective as witnessed by the fact that this phenomenon has continued also in the last three decades. at present new types of barrages allowing the passage of bed load are being designed. they are equipped with small hydroelectric plants located along the sides of the river in order to exploit the morphological step of these check dams for the activation of water turbines. in general, channel adjustments since the 19t h century have led to a change in the channel pattern from braided to transitional. this evolution is similar to what has been recorded by su r i a n & ri n a l d i ( 2 0 0 3 ; 2004) in other italian rivers. as for the causes of these modifications mainly limited to the past 50 years we fully agree with the remarks of the previously mentioned authors and the early authors who studied the river panaro. according to their views, the effects of natural causes (such as uplift of the apennine chain, subsidence of the alluvial plain, climate changes) seem to have played a minimal role, since they have had only gradual repercussions on the evolution of watercourses. on the contrary, emphasis is given to anthropogenic activities affecting the riverbeds (such as quarrying and construction of check dams). nevertheless, other causes for changes are: i) hydraulic non-equilibrium between new flow rates (concentration and increase of qmax) and canalised riverbed; ii) along long stretches water stream erodes weaker bedrock formations with lower roughness index (marine clays of the plio-pleistocene cycle, alluvial marine clays, previously underlying or juxtaposed to gravel deposits; highly weathered gravels with matrix of pleistocene deposits; see gasperi et al., 1989). iii) absence of bed load for the hydraulic arrangement of the basin in the 1950 to date period. 276 d. castaldini & a. ghinoi fig. 8 morphological sketch of the r. panaro near s. ambrogio (east of modena) in the 1930s (elaborated from the 1933 igm map) and at present (elaborated from the 2003 quick-bird satellite image and field survey). to be noted: in the northern sector, the meander cut-offs carried out in the early 1970s and, in the southern sector, the flow regulation system. legend: 1) river channel; 2) paleo-riverbed; 3) fluvial scarp (in some stretches remodelled by man's intervention); 4) artificial embankment; 5) check dam; 6) dam of the flow regulation system; 7) storage basin of the flow regulation system; 8) depleted quarry area (a: dry floor; b: flooded floor); 9) bridge; 10) built-up area. carta geomorfologica schematica del f. panaro presso s. ambrogio, (est di modena) negli anni '30 (elaborata sulla base della cartografia igm del 1934) e nel presente (elaborata sulla base delle immagini del satellite quick bird del 2003 e di rilevamenti sul terreno). legenda: 1) alveo fluviale; 2) paleoalveo; 3) scarpata fluviale (in qualche tratto rimodellata dall'antropizzazione) ; 4) argine; 5) briglia; 6) manufatto regolatore della cassa di espansione; 7) bacino d'esondazione della cassa di espansione; 8) area di cava abbandonata (a: a fondo asciutto; b: a fondo allagato); 9) ponte; 10) area antropizzata. in the mid-lower plain sector, the present course of the r. panaro was conditioned by the meander cutoffs carried out in the late 19t h century and at the beginning of the 1970s. in this study it was calculated that meander cutoffs reduced the length of the r. panaro by about 10-11 km. these length reductions correspond to about 13% of its length in this plain sector before cutoffs (tab. 2). thus, like other rivers of the mid-lower plain south of the r. po, r. panaro has taken on the appearance of an artificial watercourse for long stretches, owing to a decrease of its width and length and the disappearance of its highwater beds. these morphological changes, combined with undercutting processes, which are active also in the mid-lower plain sector, have obviously caused variations of the river's hydrometric characteristics (runoff time, height and flow rate of highwater events). since the cutoffs did not reduce flood hazard adequately, which was the primary goal of these interventions, “flow regulation systems” were constructed in the area east of modena along the river. obviously, also the construction of the flow-regulation system has contributed to modifying both the natural morphology of the riverbeds and water runoff dynamics. according to investigations carried out and data collected, it can be forecast that the r. panaro riverbed will take some more decades before finding a new equilibrium following the changes that have affected it over 50 years; although the ever-present anthropogenic activities will probably never allow a new equilibrium to be fully attained. it can be stated that the present morphology and evolution trend of the river panaro have been conditioned by direct and indirect human intervention over the past centuries, especially since the 1950s. therefore, human action as a morphogenetic agent has been once more confirmed. (padova university), m. rinaldi (firenze university) and m. pellegrini (modena and reggio emilia university) for their critical review of this paper and to a.m. lord and g. tosatti (modena and reggio emilia university) for the revision of the english text. references bettelli g., bonazzi u., fazzini p., gasperi g., gelmini r. & panini f. (1989) nota illustrativa alla carta geologica schematica dell'appennino modenese e delle aree limitrofe. mem. soc. geol. it., 3 9, pp. 487-498. bo c c o l a r i m., fr o n t e r o p., lo m b r o s o l. pu g n a g h i s . , sa n t a n g e l o l. & na n n i s. (1998) climate of modena: temperature and rainfall time series. atti soc. nat. mat. di modena, 129, pp. 5-15. carandini g. (1821-1828) carta del ducato di modena e stati limitrofi. in: pezzoli, s., venturi s., (eds.) topografia degli stati estensi. territori di modena, reggio, garfagnana, lunigiana, massa e carrara. historical maps, 1:50,000 scale, ed. compositori, bologna. ca s t a l d i n i d. (1989) evoluzione della rete idrografica centropadana in epoca protostorica e storica. in: atti conv. naz. studi “insediamenti e viabilità nell'alto ferrarese dall'età romana al medioevo”. cento, 8-9 may 1987, acc. delle sc. di ferrara, pp. 115-134, ferrara. castaldini d. (2006) geomorphological aspects of the flood hazard in the area between the rivers po, secchia and panaro (po plain, northern italy). in: v. so r o c h o v s c h i (ed.) riscuri si catastrofe. an 5 nr. 3/2006, casa cartii de stiinta, cluj napoca, issn 1584-5273, pp. 163-174. castaldini d. & pellegrini m., (1989) a review of the flow regulation systems on the secchia and panaro rivers (modena area, italy). in: c. em b l et o n, p. fe d e r i c i, g. ro d o l f i (eds.) g e o m o rphological hazards, suppl. geogr. fis. din. quat., ii, pp. 35-39. castaldini d., piacente s. (1995) channel changes on the po river, mantova province, northern italy. in: e.j. hickin (ed.) river geomorphology. john wiley and sons, london, pp. 193-207. ca s t i g l i o n i g.b. & pe l l e g r i n i g.b. (eds.) (2001) n o t e illustrative della carta geomorfologica della pianura padana. suppl. geogr. fis. dinam. quat., iv, 207 pp. ca s t i g l i o n i g.b., aj a s s a r., ba r o n i c., bi a n c o t t i a . , bondesan a., bondesan m., brancucci g., castald i n i d., ca s t e l l a c c i o e., ca v a l l i n a., co r t e m i g l i a f., co r t e m i g l i a g.c., cr e m a s c h i m., da ro l d o . , elmi c., favero v., ferri r., gandini f., gasperi g., gi o r g i g., ma r c h e t t i g., ma r c h e t t i m., ma r o c c o r., me n e g h e l m., mo t t a m., ne s c i o., or o m b e l l i g., pa r o n u z z i p., pe l l e g r i n i g.b., pe l l e g r i n i l . , ri g o n i a., so m m a r u g a m., so r b i n i l., te l l i n i c . , tu r r i n i m.c., va i a f., ve r c e s i p.l., ze c c h i r. & zo r z i n r. (1997) carta geomorfologica della pianura padana a scala 1:250.000. s.el.c.a., firenze. di dio g. (ed.) (1998) riserve idriche sotterranee della regione emilia-romagna. regione emil ia277recent morphological changes ... table 2 -length reduction of the r. panaro, following meander cut-offs, in the mid-lower sector of the plain where it flows elevated over the plain within artificial embankments. riduzione in lunghezza del f. panaro in seguito ai tagli di meandro nella media-bassa pianura dove il fiume scorre pensile tra argini artificiali. age of cutoffs 19th century 7.5 km 20th century 3 km total reduction 10.5 km present-day length 70 km length before cutoffs 80.5 km reduction (%) 13% acknowledgment research was carried out in recent years in cooperation with the land reclamation syndicate of burana-leo-scoltenna-panaro, and within the framework of cerg (centre européen sur les risques géomorphologiques, strasbourg, france) research activities and far project research of the earth science department. the authors are grateful to n. surian romagna, eni agip, s.el.c.a., firenze, 120 pp. faravelli d. & messina c. (1997) incidenza dei fattori antropici sull'evoluzione naturale dell'alveo del t. tidone (appennino pavese piacentino). atti tic. sc. terra, 39, pp. 313-327. ferrari i. & pellegrini m. (a cura di) (2007) la dinamica fluviale del po nell'ottocento e le tavole della commissione brioschi. ed. diabasis, reggio emilia, 198 pp., cd-rom attached. franceschetti b., stoppato m. & turitto o. (1990) le modificazioni del corso della dora riparia tra susa e alpignano dal 1881 al 1977: fattori naturali e antropici e riflessi ambientali. riv. geogr. it., 9 7, pp. 475-505. ga s p e r i g., cr e m a s c h i m., ma n t o v a n i ug u z z o n i m . p . , ca r d a r e l l i a., ca t t a n i m. & la b a t e d. (1989) evoluzione plio-quaternaria del margine appenninico modenese e dell'antistante pianura. note illustrative alla carta geologica, memorie società geologica italiana, 39 (1987), pp. 375-431. govi m. & turitto o. (1993) processi e dinamica fluviale lungo l'asta del po. acqua-aria 6, pp. 575588. gregory k.j. (1987) river channels. in: k.j. gregory & d.e. wa l l i n g (eds.) human activity and environmental process. wiley, chichester, pp. 207-235. he r g e t j., di k a u r., gr e g o r y k.j. & va n d e n b e r g h e j . (eds.)(2007) the fluvial system past and present dynamics and controls. special issue. vol. 92, 3-4, 220 pp. hickin e.j. (1983) river channel changes: retrospect and prospect. in: j.d. co l l i s o n & j. le w i n ( e d s . ) modern and ancient fluvial systems. spec. pub. intern. ass. sediment, 6, pp. 61-83. la j c z a k a. (1995) the impact of river regulation, 1850-1990, on the channel and floodplain of the upper vistula river, southern poland. in: e.j. hickin (ed.) river geomorphology, john wiley & sons, london, pp. 209-233. le o p o l d l.b. (1973) river channel change with time: an example. geological society of america bulletin, 84, pp. 1845-1860. leys k.f. & werrity a. (1999) river channel planform change: software for histor ical analysis. geomorphology, 29 (1-2), pp. 107-120. liebault f. & piegay h. (2002) causes of 20th century channel narrowing in mountain and piedmont rivers of southeastern france. earth surf. process. landforms, 27, pp. 425-444. lóczy d. (1997) human impact on rivers in hungary as reflected in changes of channel planform. z. geomorph. n.f. suppl.-bd.110, pp. 219-231. lombardini e. (1865) note sulle condizioni della pianura subappennina tra l'enza e il panaro e i cangiamenti ivi avvenuti. giorn. dell 'ingegnere e dell'architetto, xiiii, 176 pp. pe l l e g r i n i m. (1969) la pianura del secchia e del panaro. atti. soc. nat. mat. di modena, 100, pp. 1-53. pellegrini m., & rossi a. (1967) le variazioni del profilo d'equilibrio del fiume panaro e di alcuni suoi affluenti. atti soc. nat. e mat. modena, 98, pp. 324. pellegrini m., perego s., tagliavini & s. toni g. (1979) la situazione morfologica degli alvei dei corsi d'acqua emiliano-romagnoli: stato di fatto, cause ed effetti. atti conv. la programmazione per la difesa attiva del suolo e la tutela delle risorse: i piani di bacino idrografico. regione emiliaromagna amministrazione provincia le di modena, pp. 169-195. perego s. (1988) variazioni morfologiche recenti e studio geo.ambientale del t. enza nel tratto di conoide (province di parma e reggio emilia). l'ateneo parmense acta naturalia, 30, pp. 5-27. petts g.e. (1979) complex response of river channel morphology subsequent to reservoir construction. progress in physical geography, 3, pp. 329-362. pi e r i m. & gr o p p i g. (1981) subsurface geological structure of the po plain, italy. c.n.r., pubbl. 414 p. f. geodinamica, 13 (7), pp. 278-287. provincia di mo d e n a (2003) il recupero delle aree di cava nel terr itorio modenese (1950-2001) . quaderni di documentazione ambientale, 56 pp. ri n a l d i m., si m o n c i n i c. & so g n i d. (2005) v a r i a z i o n i morfologiche recenti in due alvei ghiaiosi appenninici: il f. trebbia ed il f. vara. suppl. geogr. fis. dinam. quat., vii, pp. 313-319. surian n. (1999) channel changes due to river regulation: the case of the piave river, italy. earth surf. process landforms, 24, pp. 1135-1151. surian n. & rinaldi m. (2003) morphological response to river engineering and management in alluvial channels in italy. geomorphology, 5 0, pp. 307326. surian n. & rinaldi m. (2004) channel adjustments in response to human alteration of sediment fluxes: examples from italian rivers. in: go l o s o v v . , belyaev v. & walling d.e. (eds.) sediment transfer through the fluvial system. iahs publ. 2 8 8, pp. 276-282. su r i a n n., pe l l e g r i n i g.b. & sc o m a z z o n e. (2005) valutazioni morfologiche dell'alveo del fiume brenta indotte da interventi antropici. suppl. geografia fisica e dinamica quaternaria, vii, pp. 339-345. we s t a w a y r.m., la n e s.n. & hi c k s d.m. (2000) t h e development of an automated correction procedure for digital photogrammetry for the study of wide, shallow, gravel-bed rivers. earth surface processes and landforms,vol. 25, issue 2, pp. 209-226. wr i g h t a., ma r c u s w.a. & as p i n e l l a. (2000) evaluation of multispectral, fine scale digital imagery as a tool for mapping stream morphology. geomorphology, 33, pp. 107-120. 278 ms. ricevuto il 30 gennaio 2008 testo definitivo ricevuto il 5 maggio 2008 ms. received: january 30, 2008 final text received: may 5, 2008 d. castaldini & a. ghinoi ojs 647 bertini et al 36,1 91-119 .pub piacenzian to late pleistocene flora and vegetation in italy: a moving sketch adele bertini1, nathalie combourieu-nebout2 1 dipartimento di scienze della terra, università di firenze, firenze, italy. 2 hpnp, umr7194 cnrs, dépt. homme et environnement, muséum national d’histoire naturelle, institut de paléontologie humaine, paris, france. corresponding author: adele bertini <adele.bertini@unifi.it> abstract: the rich late neogene and quaternary stratigraphical record for the mediterranean area is particularly useful for the reconstruction of palaeoenvironments and palaeoclimate changes. 66 italian pollen sites (38 terrestrial and 28 marine) have been selected to cover the 3.60 0.0117 ma time-interval. pollen reveals evidence for the main changes in both flora composition and vegetation structure, tracing the imprint of increasingly cooler climates on italian vegetation since the latest pliocene. the role of both altitudinal gradients and physiographic reorganizations as well as of major taxa replacements and their extinctions-times is evaluated by the study of calibrated pollen records. the response of flora and vegetation to glacial/interglacial (g/i) cycles is especially well expressed from the beginning of the pleistocene, and across the early-middle pleistocene climate transition when a major decrease in temperature, during both g/i phases, occurred. alternations of artemisia steppe and thermophilous forest illustrate the overall vegetation changes during g/i cycles. however, different patterns in the g/i vegetational cycle have been detected in both northern and southern pollen sites. the late pleistocene high-resolution pollen records document the vegetation response to rapid climate changes such as the dansgaard-oeschger “cycles” and heinrich stadials, associated with millennial to sub-millennial events. keywords: quaternary palynology, palaeoenvironment, palaeoclimate, 3.60 0.0117 ma, mediterranean. available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 36 (1), 2023, 91-119 1. introduction since the neogene, the mediterranean area has undergone palaeogeographic and palaeoclimatic changes that have gone hand in hand with significant orogenic activity, which led to the uplift of several chains including the apennines, in italy (e.g. carminati & doglioni, 2012). the collision of the african and eurasian plates reduced the tethys domain from the early miocene onwards. active atlantic-mediterranean water exchanges, through the betic and rifean corridors, assured open marine conditions and circulation until ca 7.2 ma, while the progressive restriction of the corridors accentuated the isolation of the mediterranean basin and supported, at a regional scale, the development of the so-called messinian salinity crisis, from 5.97 ma (e.g. clauzon et al., 1996; roveri et al., 2014). at 5.33 ma open marine conditions were restored at the base of the pliocene (e.g. van couvering et al., 2000). significant geomorphic modifications linked to the progressive uplift of the apennines promoted the formation of numerous eastwardprogressing and younger, marine and continental basins, extending wsw of the orographic divide (e.g. martini & sagri, 1993; santangelo et al., 2012; cosentino et al., 2017). at a global scale, the maximum extension of the arctic ice promoted the onset of well-expressed glacial/interglacial (g/i) cycles from 2.6 ma (berger & loutre, 1991; lisiecki & raymo, 2005; sarnthein et al., 2009). the set of previous changes gave rise, at a regional scale, to important reorganization and restructuring of the italian vegetation, also affecting vertebrate communities, as attested by significant turnover events (e.g. masini & sala, 2007; palombo, 2007, 2014; magri & palombo, 2013; strani et al., 2021), and rearrangement of terrestrial ecosystem structures and patterns. the high number of italian neogene and quaternary deposits has encouraged advances in several areas of geo-stratigraphical research, including palynological analyses. terrestrial vegetation can be reconstructed from the rich pollen records preserved in marine and continental successions, providing a detailed picture of the spatial and temporal modifications of flora, vegetation and climate (e.g. bertini, 2003, 2010; sadori et al., 2013; combourieu-nebout et al., 2015; magri et al., 2017 and references therein). by integrating previous summaries, the present pollen-based review provides an overview of pleistocene italian flora, vegetation, and climate as well as a coherent and comprehensive history of the italian palaeoenvironments, according to a solid stratigraphic framework (fig. 1; tab. 1). https://doi.org/10.26382/amq.2023.05 knowledge of past palaeoenvironments and climate context is highly important in a geological perspective and is crucial for correctly evaluating the present-day ecological and biogeographical patterns; appropriately applied, this knowledge can contribute to biodiversity conservation and landscape restoration. 2. present-day climate and vegetation italy extends at mid-latitude (between 47°n and 35°n) into the mediterranean sea, between the balkan and hellenic peninsula to the east, the iberian peninsula to the west, north africa to the south and continental europe, from which it is separated by the alps, to the north. three major sectors are recognised (figs. 1, 2): a continental sector (northern italy), between the alps to fig. 1 location map of selected piacenzian and pleistocene marine and continental sites. see also table 1 for the numbering of the sites and additional information. heavy black dotted line traces the 42.5°n isocline. 92 bertini a., combourien-nebout n. the north and the conventional line connecting la spezia with rimini to the south (fig. 1); a peninsular sector (central and southern italy, fig. 1), which stretches into the mediterranean in a north-west-south-east direction; and an insular sector encompassing the two largest islands of the mediterranean, namely sardinia and sicily. its territory is largely occupied by hills (up to ca 42 %) followed by mountain (35%), and flat areas (23%). its highest point stands at 4811 m (monte bianco, aosta) while the lowest point lies at 3.44 m (contane, ferrara). the italian climate includes, according to the köppen climate classification, a humid temperate climate (cfa / cfb) to the north and a mediterranean climate with a dry summer period (csa) in the centre-south. a complex climatic gradient is very evident moving from the southern warm-temperate mediterranean climate, through the cool-temperate climate of the apennines and prealpine ranges, to the continental climate of the innermost alps with its marked temperature seasonality. the italian flora comprises more than 7000 species (pignatti, 1982) whose distribution is strongly connected to the complex topographic and climatic features of its territory. plant biodiversity is very high, and endemism is widespread. the italian vegetation has been well documented in a large number of publications (e.g. tomaselli et al., 1973; ozenda, 1975, 1994; bonin, 1981; pignatti, 1998; quézel & médail, 2003; blasi, 2010). the european potential natural vegetation zones and the main physiognomic-ecological units for the italian peninsula are summarised in fig. 2 (modified from pignatti, 2011). 3. materials and methods several italian marine and continental pollen records have been selected for the time interval from the piacenzian to upper pleistocene. the geographical distribution of the pollen sites is shown in fig. 1. for each site, the main stratigraphical and geological information is summarized in tab. 1 (see also bertini, 2003, 2010; combourieu-nebout et al., 2015; magri et al., 2017, and references therein). the most significant pollen evidence for selected single sites is summarized in section 4. 3.1. pollen records the abundance of pollen records permits the detection of past environmental changes and allows the reconstruction of the history of the flora, vegetation and climate throughout the pleistocene in italy. the piacenzian is also part of this revision, particularly for documenting the last warm period preceding the installation of the g/i cycles at 2.6 ma. the main palaeoenvironmental events, acting at both global and mediterranean scales, are taken into account in the reconstructions. each pollen site and its associated record have been assigned to either “northern” or “southern” italy, relative to latitude 42.5°n, according to the isocline for current dry season duration (longer or shorter than 3 months) (fig. 1heavy black dotted line). pollen-inferred vegetation from available well calibrated records (tab. 1 and figs. 3-7) is used to illustrate the succession of climatic and environmental changes within six key stratigraphical intervals during the last 3.6 myr: piacenzian (3.6 2.58 ma), gelasian (2.58 1.80 ma), calabrian (1.80 0.774 ma), chibanian (0.774 0.129 ma), and late pleistocene (0.129 0.0117 ma). in the text piacenzian to pleistocene flora and vegetation in italy 93 fig. 2 present-day vegetation and climate in italy (modified from pignatti, 2011). a selection of climate (ombrothermic) diagrams (calculated using the newlocclim software, grieser et al., 2006) illustrates the modern north-south climate gradient. 94 bertini a., combourien-nebout n. ta b. 1 ( a a nd b ). li st o f t he s el ec te d p ia ce nz ia n an d p le is to ce ne s ite s w ith th e m ai n st ra tig ra ph ic al , g eo lo gi ca l a nd p al yn ol og ic al r ef er en ce s. n um be rs o n th e le ft re fe r to th e ge og ra ph ic al lo ca tio n of s ite s as r ep or te d in f ig . 1. f l/p /l : fl uv ia l-p ea t-l ac us tri ne ; m /l g/ d : m ar in ela go on al -d el ta ic . p : p ia ce nz ia n, g : g el as ia n, c a: c al ab ria n, c h: c hi ba ni an , lp s: l at e p le is to ce ne . r ef er en ce s in cl ud in g pa ly no lo gy a re in b ol d; o th er re fe re nc es in it al ic . t he h ea vy b la ck d ot te d lin e in t ab le 1 a tr ac es th e 42 .5 °n is oc lin e. 95 piacenzian to pleistocene flora and vegetation in italy “taxodiaceae” is in quotation marks; many genera formerly assigned to taxodiaceae are now grouped in subfamilies of cupressaceae, for example taxodioideae endl. ex k. koch (taxodium, glyptostrobus, and cryptomeria) and sequoioideae (luerss.) quinn (sequoia, sequoiadendron, and metasequoia) whereas the genus sciadopitys is now generally placed in sciadopityaceae (brunsfeld et al., 1994; farjon, 1998, 2005). in the italian pollen records, “taxodiaceae” are mainly represented by sciadopitys, taxodium type (which includes taxodium cf. distichum and glyptostrobus) and sequoia type (which includes sequoiadendron giganteum, sequoia sempervirens, metasequoia glyptostroboides, cunninghamia and cryptomeria). a sketchy reconstruction of vegetation distribution is proposed for the piacenzian to late pleistocene, according to different transects from non-specific areas of high relief to coastal areas (figs. 3 7). the arboreal plant cover is in accordance with ap (arboreal plants) / nap (non-arboreal plants) percentages values in pollen diagrams. however, the density and distribution of vegetation are not based on accurate estimates, they only provide a snapshot of vegetation in various areas at different times. the distribution of main taxa is illustrated by informal “plant symbols” and is supplemented by the evidence from previous works integrating pollen and macroflora (bertini & martinetto, 2008, 2011; combourieu-nebout et al., 2015). 3.2. chronology age models for the most recent time intervals are based on 14c dates, links to greenland ice-core records and tephra dates. for the geologically older records k/ ar dates, biostratigraphy (foraminifers and nannofossils), tuning to oxygen isotope records from mediterranean or atlantic marine sediment cores and astronomical tuning were variously used (tab. 1). the chronological framework for terrestrial sites was often provided by biochronology (mammal fauna and palaeomagnetism; e.g. napoleone et al., 2003). it is undoubted that the chronological control of all published age models is quite critical, especially for the older sites (e.g. sarzana and compiano sites; fig. 1, tab. 1). it is not part of our review to discuss the individual age models, and in tab. 1 all sites are noted whether they have a reliable chronology or not. 4. an overview of the italian pollen evidence 4.1. piacenzian (3.6 2.58 ma): the last subtropical forests (fig. 3) during the piacenzian a transition from relatively warm to cooler climates starts to develop until the instauration of high-magnitude g/i oscillations during the quaternary. short-lived cooling episodes punctuated this interval reflecting a progressive decline of temperature. just after glacial marine isotope stage m2, at ∼ 3.3 ma, during the last climate phase that was warmer than today, known as mid-piacenzian warm period (mpwp; e.g., dowsett et al., 2012; haywood et al., 2013; de schepper et al., 2013; de la vega et al., 2020, 2021), sea surface temperatures increased by up to ∼3 °c (haywood and valdes 2004), and co2 concentrations reached values of 400 ppm (pagani et al., 2009; bartoli et al., 2011), similar to the modern anthropogenic values. the italian pollen record is quite remarkable for these last 700 kyr of the piacenzian but it lacks continuous data for the interval spanning the zancleanpiacenzian transition; this is the time when modern european climates begin to develop at ca 3.6 ma (e.g. zagwijn & suc, 1984; suc et al., 1995) in conjunction with a cooling event, and the brunssumian-reuverian transition (zagwijn, 1960; north west european stagesnwes, cohen & gibbard, 2022). in central italy, at santa barbara (upper valdarno intermountain basin) a rich and diverse vegetal assemblage (e.g.taxodium/glyptostrobus type, nyssa, engelhardia, itea, symplocos, cephalanthus, myrica, carya, quercus, carpinus, ulmus, zelkova, clethraceae, cyrillaceae) is documented during the short-lived ‘warm blip’ centred at 3.0 ma, after the mg2 and m2 cold culminations. a humid forest vegetation, typical of subtropical to warm-temperate climate, dominated swamps in a lacustrine system, up to about 2.8 ma when a cooler forest, with picea and fagus, as main components, became widespread. herbs including steppe taxa formed a very minor component (napoleone et al., 2003; bertini, 2010, 2013). the cooling occurred gradually, in agreement with isotopic records (e.g. raymo et al., 1989) that show an increase in glacial intensity over several cycles, rather than an abrupt increase at 2.6 ma. a permanent/ temporary disappearance and/or the significant reduction of some taxa (e.g. symplocaceae, myrica, nyssa, cephalanthus, “taxodiaceae”), points to a progressive floristic impoverishment in many sites of both central (e.g. lower valdarno: valleri et al., 1990, benvenuti et al., 2007; and tiberino basin: pontini & bertini, 2000, pontini et al., 2002, martinetto et al., 2014) and northern (villafranca: francavilla et al., 1970, lona & bertoldi, 1972, carraro et al., 1996; stirone: bertini, 2001; val marecchia: rio et al., 1997; m. falcone-rio crevalese: monegatti et al., 2002) italy. the decrease in temperature, associated with the forthcoming onset of the north hemisphere glaciation, resulted in a gradual increase in relatively more resilient arboreal plants such as quercus and carya, which progressively replaced taxodium/ glyptostrobus type and engelhardia (bertini, 2001; fauquette & bertini, 2003). in southern italy, the piacenzian is only represented by rather short and discontinuous pollen records. at 3.31 ma (close to the fad, first appearance datum, of globorotalia bononiensis) on the site of bianco, a cool, humid climate (with decreased seasonality) has been reconstructed during a short-term forest phase dominated by the picea-abies group, while mediterranean evergreen virtually disappeared and non-arboreal cover declined (bertoldi et al., 1989). between 3 and 2.92 ma, marine isotope stage (mis) 108 to 104 (combourieunebout et al., 2004), at punta piccola, a well-diversified pollen flora suggests an altitudinal zonation of the vegetation and several climate fluctuations during precession cycles illustrated in laminites/carbonates couplets. climate reconstructions from the high resolution pollen 96 bertini a., combourien-nebout n. 97 fig. 3 the piacenzian. on the left (top to bottom): location map of the piacenzian sites (for numbers, see also tab. 1), list of main taxa now extinct in italy and main vegetation groups during the 21 to 41 kyr cycles in north and south italy. on the right the sketchy vegetation profiles for north and south italy. fig. 4 the gelasian. on the left (top to bottom) location map of the gelasian sites (for numbers, see also tab. 1), list of main taxa now extinct in italy and main vegetation groups during the 41 kyr cycles in north and south italy. on the right the sketchy vegetation profiles for north and south italy. piacenzian to pleistocene flora and vegetation in italy record indicate that high temperatures and relatively intense precipitation prevailed during the deposition of brown laminated sediments; in contrast, arid conditions are associated with light carbonates. still in sicily, just before 2.5 ma, at the site of capo rossello, an expansion of mediterranean formations alongside the presence of open vegetation (including steppe and psammophilous taxa), is documented during a general decrease in humidity and the establishment of drier conditions during the warm season (guerrera et al., 1984; bertoldi, 1985a; bertoldi et al., 1989; rio et al., 1990). at stirone in northern italy, climate amplitude method (cam) reconstructions are only available for the last 200 ka of the piacenzian (fauquette & bertini, 2003). they indicate alternating warm/cold phases with temperature and precipitation values very close to those associated with g/i cycles during the following gelasian (see in 4.2.1). 4.2. the pleistocene 4.2.1. gelasian (2.58-1.80 ma): the decline of subtropical trees and the onset of g/i cycles at the beginning of the quaternary (fig. 4) the intensification of the mediterranean outflow and the establishment of the northern hemisphere ice cap from ∼ 3.0 ma (e.g., marlow et al., 2000; lisiecki & raymo, 2007) promoted cooler, more seasonal and in some areas dryer conditions in the mediterranean area (lourens et al., 1996, 2004). in the italian pollen records, 40 kyr obliquity-forced g/i cycles are predominantly characterized by the contrast between forest vegetation and steppes (e.g. bertini, 2010; combourieunebout et al., 2015 and references therein). this pattern is especially well attested in the semaforo section (crotone, calabria; e.g. combourieu-nebout & vergnaud-grazzini, 1991; combourieu-nebout, 1993, 1995; lourens et al., 1996) by both pollen and oxygen isotope data, from 2.46 ma onwards. nevertheless, in other southern italian sites, bertoldi et al. (1989), have highlighted a totally different (opposite) response of the vegetation to g/i cycles, still on the basis of the biostratigraphic and isotopic evidence. in the gelasian (calabrian) le castella and gela (monte san nicola) sites, glacials would have been marked by forests (humid conditions), and interglacials by open vegetation (dry conditions). a different scenario emerges from the northern italian pollen records (castell’arquato: lona, 1962; lona & bertoldi, 1972; stirone: lona & bertoldi, 1972; bertolani marchetti et al., 1979; bertini, 2001; val marecchia: rio et al., 1997; m. falcone-rio crevalese: monegatti et al., 2002). here g/i cycles are apparently characterized by contrasts between the subtropical to warm temperate forest and higher-elevation coniferous forest (mainly picea) without any significant extension in space and time of steppe-like vegetation (minimum values of humidity). herb percentages usually remain low although artemisia, a steppe taxon, can increase but not significantly and according to the specific geographical locations of the above mentioned sites. in the upper valdarno (central italy), the location of the piacenzian santa barbara section, we find evidence for the first substantial spread of herbs, which include a very large component of artemisia (bertini, 1994, 2010), within a distinctive aeolian-dominated sandy deposit (rena bianca section), 35 m thick. on the other hand, in the tiberino pollen record, which falls within the piacenzian-gelasian transition (pontini, 1997; pontini & bertini, 2000; pontini et al., 2002; martinetto et al., 2014), the vegetation response to the g/i cycles is expressed by the competition between coniferous forests dominated by picea and thermophilous arboreal taxa including “taxodiaceae” (mis 100 to mis 82). during the gelasian the flora suffers a very evident and progressive impoverishment. in northern italian pollen sites, the first notable reduction in “taxodiaceae” (with taxodium/glyptostrobus type as the main component) as well as an increase of cathaya are evident from ca. 2.7 ma (at stirone). in the south, at semaforo, where the record starts at 2.48 ma, the first significant demise of “taxodiaceae” forests (with sequoia type as main component) is recorded from about 2.38 ma whereas the spread of cathaya occurs, especially from ca. 1.92 to 1.74 ma (combourieu-nebout & vergnaud-grazzini, 1991; combourieu-nebout, 1993; klotz et al., 2006; suc et al., 2010). cam reconstructions from stirone (northern italy) (fauquette & bertini, 2003) show that during the gelasian warm phases, the climate was similar to that of the zanclean, with high mat, map and available moisture. annual temperatures were almost equal to the modern value (around 12-13 °c) during glacials whereas precipitation values were between 200 and 500 mm higher than today. in central italy, at poggio rosso (upper valdarno) dating to a g/i cycle just before the gelasian/calabrian boundary, the cam method was used to calculate mean annual temperatures of around 12.5-14 °c and mean annual precipitation of around 800 mm, with a minimum of 400 mm during the glacial phase and 15/16-19 °c and 750 -1200 mm during the interglacial (bertini et al., 2010). in southern italy, at semaforo, the probability mutual climatic spheres (pcs) method reveals mean annual temperatures and winter temperatures from ca. 2.46 ma to ca. 2.11 ma (klotz et al., 2006) that were at least 2.8 °c and 2.2 °c warmer, respectively, than today; it also reveals that annual precipitation during interglacials exceeded today’s values by 500 mm. during glacials, temperatures were lower than the present-day, but precipitation was similar. a trend of reduction in annual and winter temperatures (more than 2.3 °c), as well as greater seasonality, were also highlighted over the course of the consecutive interglacials. a significant reduction of at least 1.6 °c in all temperature parameters is also evident during the glacials. 4.2.2. calabrian (1.80-0.774 ma): the demise of subtropical ecosystems from the mediterranean and the beginning of the early-middle pleistocene transition (fig. 5) from 1.4 ma, over the course of the calabrian, a major global climatic reorganization starts to affect ocean and atmospheric circulation, ice sheets and the distribution and evolution of biota, including the ancestors of modern humans (head & gibbard, 2015). during 98 bertini a., combourien-nebout n. this phase, termed the early-middle pleistocene transition (empt) which extends up until 0.4 ma, lowamplitude 41-ka obliquity-driven climatic cycles of the earlier pleistocene were progressively superseded by 100 kyr fluctuations in the later pleistocene. a succession of severe glacial episodes (i.e. mis 36, 24, 22) occurred, particularly in the northern hemisphere. a rich and detailed palynological record, often very well calibrated, is available for southern italy in particular. in the crotone basin (calabria) the most significant pollen sites are: vrica (ca. 2.2-1.36 ma; e.g. combourieunebout et al., 1990), santa lucia (1.356-1.24 ma, mis 43-40; joannin et al., 2007), and valle di manche (0.870.73 ma, mis 22-18.3; capraro et al., 2005, 2015, 2017, 2022). moreover, in basilicata some 150 km north of the crotone basin, the marine montalbano jonico (1.24-0.9 ma and mis 37-mis 23: joannin et al., 2008; 0. 820.774 ma and mis 20-19 p.p.: bertini et al., 2015; toti, 2018; toti & bertini, 2018; nomade et al., 2019;) and the neighbouring continental sant’arcangelo (san lorenzo cycle: ca. 1.1-0.8 ma; sabato et al., 2005) successions were also studied. in sicily, data for the 1.231.095 ma interval are available from the monte san giorgio section (caltagirone; dubois, 2001). in the uppermost part of these sites, g/i fluctuations are well illustrated by open vegetation and forest alternations. the open vegetation assemblages include a large amount of steppe taxa, including artemisia and ephedra, and sometimes also thermophilous taxa, such as cistus and phlomis fruticosa. warm temperate forest assemblages include mainly deciduous taxa, such as quercus, carya, carpinus, pterocarya, ulmus and zelkova after the progressive reduction and disappearance of the most thermophilous taxa, e.g. “taxodiaceae”. however, according to capraro et al. (e.g. 2005, 2015), in the marine valle di manche succession, the glacial interval mis 20 (as well mis 18) is characterized by an alpine type forest (picea, abies, fagus), whereas a wooded steppe landscape was established only later (i.e. at the matuyama-brunhes boundary), during the early-middle pleistocene climatic transition, at the beginning of the deglaciation from mis 20 to mis 19. another very different scenario is expressed by the pollen records from northern italy (lamone, stirone, leffe, pianengo). here, glacial phases are, as in the gelasian, often marked by expansions of coniferous forests dominated by picea, although interglacials do not exhibit major expansions of steppe vegetation but rather thermophilous forests as described in the classic schemes of combourieu-nebout (1993) and fusco (2007). in the lamone marine succession three distinct forest formations, i.e. mixeddeciduous forest (with quercus dominating), juglandaceae forest (with carya dominating) and mountain coniferous forest (with picea dominating) expanded between mis 64-46 (fusco, 2007, 2010). a complete vegetation cycle only developed when forest dynamics were interrupted by the spread of open vegetation, indicating a decrease in humidity (fusco, 2007). flora continued to be depleted as documented, in more detail, in 99 fig. 5 the calabrian. on the left (top to bottom), location map of the calabrian sites (for numbers, see also tab. 1), list of main taxa now extinct in italy and main vegetation groups during the 41 kyr cycles in north and south italy. on the right the sketchy vegetation profiles for north and south italy. piacenzian to pleistocene flora and vegetation in italy both bertini (2010) and magri et al. (2017) papers which also traces the abundance, reduction, and disappearance of certain key taxa (e.g. “taxodiaceae”, cathaya, tsuga, carya, pterocarya) in selected sites (e.g. vrica, saticula, madonna della strada, colle curti, formaci di ranica, pianengo, and piànico-sèllere). the disappearance of the subtropical ecosystems and their replacement by deciduous forest taxa was identified in the mediterranean area at ca. 1.2 ma (combourieu-nebout & vergnaud-grazzini,1991; combourieu-nebout, 1993, 1995) i.e. after the appearance of the large gephyrocapsa a coccolith (at about 1.56 ma), and the foraminifer hyalinea baltica (at about 1.49 ma). climate reconstructions, using the pollen data, indicate an enhanced cooling between 1.4 and 1.3 ma, with winter temperatures decreasing at both interglacial maxima and glacial minima (combourieu-nebout et al., 2015). during the same interval, annual precipitation during both interglacial and glacial stages decreased marking a progressive increase in aridity, especially in glacial times. 4.2.3. the chibanian (0.774-0.129 ma): the development of temperate broadleaf and mixed forests in full empt (fig. 6) in the mediterranean area, the progressive floristic impoverishment, according to climate gradients, continues during the upper portion of the early-middle pleistocene climate transition, which also includes some severe glacial episodes (i.e. mis 12 and 6). the 41 kyr g/i cycles were replaced by 100 kyr cycles, with lengthening of glacial stages (tzedakis, 2005, 2007; leroy, 2007; tzedakis et al., 2012). however, from mis 11 onwards, an abrupt increase in both interglacial temperatures and in reconstructed interglacial co2 values (masson-delmotte et al., 2010; lang and wolff, 2011; mcclymont et al., 2013 and references therein) is revealed by marine, terrestrial and ice-core records during the so-called mid-brunhes event (mbe). early chibanian pollen records from southern sites attest to widespread alternations between artemisia (plus ephedra) steppes and temperate to warmtemperate deciduous forests, during the still dominant 41 kyr g/i cycles. at montalbano jonico, clear expansions of steppe taxa are documented, during both glacials and stadials from mis 19 and the base of mis 16 (e.g. bertini et al., 2015; toti, 2018; toti & bertini, 2018; nomade et al., 2019). at valle di manche, mis 18 is again (as well mis 20) characterized by an alpine type forest (picea, abies, fagus) according to capraro et al. (2005, 2015). at piànico sèllere in northern italy (prealps, lombardy) pollen data document a long interglacial phase within mis 19, dated by the k/ar age of a tephra level (779±13 ka; pinti et al., 2001) and palaeomagnetic data (scardia & muttoni, 2009) within biogenic varved sediments. here the onset of the interglacial is marked by the expansion of broad-leaved deciduous thermophilous forests with quercus, ulmus, tilia and fraxinus, followed by the expansion of abies and carpinus betulus. the interglacial succession is interrupted by a short phase characterized by the almost complete disappearance of thermophilous trees and the expansion of conifer forests (picea, pinus, larix) and herbaceous steppe communities (ravazzi, 2003; pini et al., 2014). a generalized drop in temperature in both steppe and forest phases is indicated by changes in the floristic assemblages; for example, hippophaë rhamnoides expanded during the steppe phases (“cold steppes”), whereas thermophilous taxa, such as cistus and phlomis fruticosa, disappeared. the best calibrated pollen sites permitted the tracing of the chronological distribution of some taxa, notably of “taxodiaceae”, carya, pterocarya and tsuga, including their lo (last occurrence) or lco (last common occurrence). in northern italy, tsuga is virtually absent at pianengo, from the late early pleistocene, and only sporadic pollen grains (0.2-0.8%) were recovered during the early middle pleistocene (muttoni et al., 2003). in central italy tsuga declined during the lower part of the brunhes (bertini, 2000); here, both carya and pterocarya are absent. at torre mucchia (abruzzi) tsuga is still present (at >3%) during mis 17 according to pieruccini et al. (2016). at rignano flaminio (latium) in a diatomite deposit attributed to mis 13, tsuga is absent whereas carya and pterocarya are sporadic (di rita & sottili, 2019). at the archaeological site of ceprano, just below the stratum including hominin remains, pollen analyses permitted a detailed picture of interglacial vegetation development during mis 13 (margari et al., 2018). here tsuga is absent and cedrus sporadic, whereas carya exhibits a continuous presence. moving further south, tsuga is present at valle di manche until mis 18 (ca. 0.73 ma) but with values that never exceed 5%; taxodium, carya, pterocarya, liquidambar and cedrus are also present in low percentages; the lo of carya, specifically, has been recorded between mis 18 and the successive wooded steppe expansion. at vallo di diano, between 0.65-0.45 ma (mis 16 to 13) tsuga is virtually absent (as well as at isernia la pineta; lebreton, 2002) whereas carya is constantly present, and pterocarya is sporadic (russo ermolli, 1994). at sessano, in contrast, tsuga, along with cedrus, zelkova as well as a few grains of pterocarya and taxodium type have been recorded between ca 0.58 and 0.44 ma (mis 15-12) (russo ermolli et al., 2010a). both tsuga and carya are absent in the mercure basin (mis 13; petrosino et al., 2014b) as well as in the lacustrine succession of acerno, where pollen analyses documented an interglacial/glacial cycle correlated with mis 14 and 12 (petrosino et al., 2014a). at boiano, tsuga is absent whereas carya is present until the mis 9 which, at present, represents its latest occurrence in western europe (orain et al., 2013, 2015). according to previous data, tsuga apparently disappeared from southern italy later than in the north. however, in the southern assemblages its presence is usually subordinate, at least since the messinian (suc & bessais, 1990; bertini et al., 1998). bertini (2000), on the one hand, related the disappearance of tsuga to the shift in global aridity as well as the progressive decrease in temperature associated with the middle pleistocene shift from the 41 to 100 ka cyclicity in the milankovitch orbital record (bertini, 2000). ravazzi et al. (2005), on the other hand, linked the tsuga decline (at fornaci di ranica) to catastrophic fires triggered by summer 100 bertini a., combourien-nebout n. 101 fig. 6 the chibanian. on the left (top to bottom), location map of the chibanian sites (for numbers, see also tab. 1), list of main taxa now extinct in italy and main vegetation groups during the 41 to 100 kyr cycles in north and south italy. on the right the sketchy vegetation profiles for north and south italy. fig. 7 the late pleistocene. on the left (top to bottom), location map of the late pleistocene sites (for numbers, see also tab. 1), list of main taxa now extinct in italy and main vegetation groups during the 100 kyr cycles in north and south italy. on the right the sketchy vegetation profiles for north and south italy. piacenzian to pleistocene flora and vegetation in italy drought. however, both hypotheses confirm the global shift toward aridity of the early middle pleistocene climate transition at ca. 0.9 ma (ruddiman et al., 1989; raymo et al., 2004). rare climate data from pollen records provide evidence for increasing drought during increasingly and longer glacials, while the shorter interglacial began to become cooler (combourieu-nebout et al., 2015). 4.2.4. the late pleistocene (~0.129-0.0117 ma): towards the present under the effects of the submilankovitch-scale climate variability (fig. 7) the reconstruction of millennial and sub-millennial fluctuations during the last g/i cycles and the associated floristic and vegetational changes before the main anthropic interferences have mainly been based on the pollen records, especially lacustrine ones, from northern (azzano decimo and fimon; pini et al., 2009a,b; 2010, 2022; badino et al., 2020a,b; venice pro parte: mullenders et al., 1996, massari et al., 2004, canali et al., 2007), central (valle di castiglione: follieri et al., 1988; lagaccione: magri, 1999; vico: leroy et al., 1996, magri & sadori, 1999) and southern (laghi di monticchio: e.g. brauer et al., 2007a) italy. however, a number of marine sedimentary successions were also retrieved from cores in the mediterranean area (figs. 1, 7; tab. 1). recurrent forest and open vegetation developments as well as vegetation dynamics, together with repetitive changes in the vegetation structure, flora composition and plant biomass, are documented by the mainly continuous high resolution pollen records. forest phases developed during the eemian according to a dominant vegetation pattern and with the presence of a small number of taxa now extinct in italy (e.g. pterocarya and cedrus; magri et al., 2017). in fact, most of the changes in floral composition occurred in earlier times. in contrast, steppe phases, usually characterized by the same flora (e.g. artemisia, poaceae, amaranthaceae), are generally less typical with respect to the interglacial ones. at azzano decimo (north-eastern italy), during the last 0.215 ma the mixed temperate forests persisted during mis 7a-7c, whereas they were replaced by the conifer forests after the local glacio-eustatic regression, during early mis 6 (pini et al., 2009a). the azzano decimo eemian forest record, though incomplete, indicates the absence of mediterranean evergreen trees, in accordance with the lake fimon sequence. here, mixed oak forests characterized the first part of the last interglacial; these were then replaced by oceanic mixed forests that persisted for a further 7 ka until the end of the eemian succession (pini et al., 2010). at azzano decimo, repeated stadial-interstadials are evident since ca 0.115 ma. a correlation has been proposed between major xerophyte peaks and ird (ice rafted debris) maxima during heinrich events in deep-sea cores offshore iberia and in the north atlantic. as a consequence, the interstadial phases, marked by picea peaks, were interpreted as being linked to dansgaardoeschger warm events (pini et al., 2009a). the disappearance of broad-leaved thermophilous forests from the north-eastern plain of italy was placed at the end of the early würm with cool-temperate mixed forests persisting in the southern alpine foothills up until the onset of heinrich stadial 4 as documented in the lake fimon record (pini et al., 2010).this high-resolution multiproxy record (including pollen and dust flux) from lake fimon (pini et al., 2022) provided climate evidence of the mis 3-2 interval with a focus on the dynamics of the alpine last glacial maximum and the early alpine lateglacial, including the expression of heinrich stadial 2 and 1, on land. the onset of the last glacial maximum at 27.3 ka was associated with a 4 °c drop in july temperatures, likely responsible for the onset of glacial build-up in the southern alpine piedmont (pini et al., 2022). in central italy, the integrated pollen records from the crater lakes of valle di castiglione, lagaccione and lago di vico document the history of vegetation covering the last two interglacials (last 0.3 ma, from mis 7e). the evidence for floral and vegetation changes allows the most important events e.g. eemian, saint germain i and ii and the pleniglacial interstadials (lazio complex) (follieri et al., 1998) to be recognized. at valle di castiglione, the eemian is characterized by the large scale expansion of thermophilous and mediterranean vegetation (follieri et al., 1988, 1998). the saint germain i forest phase at both valle di castiglione and lagaccione is expressed by the expansion of fagus and abies. the subsequent steppe period is characterized by the almost total absence of trees with the exception of pinus. due to a core gap, the saint germain ii forest phase, is not recorded at valle di castiglione, whereas it is well characterized at lagaccione and lago di vico by the consistent spread of abies. during the following glacial and lateglacial phases, artemisia, poaceae, and amaranthaceae alternately dominated. these steppe and grassland formations were interrupted during the pleniglacial (roughly corresponding to mis 3) by a number of slight expansions of tree cover, in particular of mesophilous and thermophilous taxa; this is termed the “lazio complex” by follieri et al. (1998) and probably corresponds to the heinrich events found in oceanic cores. at monticchio (southern italy), varve chronology indicates the onset of the sedimentation at about 0.133 ma (mis 6 to present, allen & huntley, 2009 and references therein). regional vegetation was dominated by herbs with steppe taxa as the main components during mis 6, 4, and 2. during melisay 1 only, the decrease of steppe taxa together with an increase in betula probably suggest that, although cold, this period had greater moisture availability than other cold periods. mesic woody taxa reached moderate abundance during a large number of mis 3 interstadials, but dominated during the saint germain i and ii and eemian. palaeoclimatic reconstructions as well comparisons with the main european sites reveal significant complexity in the geographical and altitudinal environmental patterns (allen & huntley, 2000, 2009). pollen-based climate reconstructions for southern italian sites (combourieu-nebout et al., 2015) show that the mean temperature of the coldest month (mtco) during marine isotope sub-stage 5e was nearly as warm as during the early pleistocene interglacials. nevertheless, annual precipitation remained low compared 102 bertini a., combourien-nebout n. to the earlier interglacials. during glacials, both temperature and precipitation values were very low. this is probably linked to recurrent mediterranean cooling, along with increased aridity on the continent induced by the global climate effects of heinrich event discharges in the north atlantic, as is also attested by palynological studies on the spanish and portuguese margins (e.g. combourieu-nebout et al., 2002; sánchez gòni et al., 2002). 5. discussion the present overview of italian pleistocene pollen records includes a total of 66 selected pollen sites (with 12 also providing information for the piacenzian) studied since 1950 (i.e. lona, 1950) (fig. 8). a large number of continental (including freshwater terrestrial carbonates such as travertine, calcareous tufas and flowstone) (38) and marine (28) sedimentary successions (sites) are presented, as well as a few sedimentary successions from depositional transitional environments (tab. 1). pollen records are especially abundant for the calabrian and chibanian. the majority of marine pollen records refer to the gelasian when we exclude the offshore sites from the late pleistocene; most sites are located on the south. continental records refer especially to chibanian; again, southern sites are the most abundant. different vegetational belts, at different altitudes between sea level and 850 m a.s.l. (colfiorito basin: colle curti cesi composite section; bertini, 2000) and between the latitudes 45 and 36 °n, have been documented. 5.1. flora and vegetation the piacenzian and pleistocene pollen floras include six main “formation classes”, informal biome/ vegetation units (bertini, 2001), i.e. tropical forest (only some rare, scarce taxa, especially present in southern sites), subtropical humid forest, temperate broadleaved deciduous forest, sclerophyll forest, midto high -elevation forest, open vegetation. in tab. 2 these have been organized in 13 informal pollen groups. their main components as well as their associated climatic and ecological features, are also summarized in bertini & martinetto (2008). over the last 3.6 ma, the composition of such “formation classes” has changed due to the gradual disappearance of some of their main components. the analysis of the stratigraphical distribution of taxa has highlighted frequent asynchronous disappearance events determined by the occurrence of climate gradients across the mediterranean (e.g. bertini, 2010; combourieu-nebout et al., 2015; magri et al., 2017). some taxa (e.g. engelhardia, “taxodiaceae”, cathaya, tsuga, carya, cedrus, liquidambar, symplocos, nyssa, pterocarya, embolanthera, distylium, parrotiopsis, parrotia persica) attained the status of relict under particular microclimatic and (or) edaphic conditions before their definitive extinction under the effects of the progressive decrease of temperature and changes in the amount and distribution of precipitation. the floristic and vegetation changes, affecting the late pliocene and pleistocene italian terrestrial ecosystems, in particular the first significant spread of steppe formation class close to 2.6 ma and the disappearance of the “subtropical humid forest” formation class close to 1.2 ma, contributed to the establishment of the present complex mosaic of different climates/biomes in the mediterranean area (tab. 3). 5.2. pleistocene glacial/interglacial cycles: an overview of the main vegetation patterns at the milankovitch-scale climate variability four (1-4) main vegetal patterns associated with g/i cycles have been identified on the basis of the available italian pleistocene pollen record (bertini, 2010) (fig. 9, tab. 3). pattern 1 is expressed by fluctuations between open vegetation and thermophilous forests. it is usually considered as the most typical and representative pattern for the mediterranean littoral (e.g. combourieunebout & vergnaud-grazzini, 1991; suc et al., 1995a). during the first quaternary cycles, it embraces four main subzones (a-d in combourieu-nebout, 1993): (a) mixed temperate forest (transitional phase following a glacial, with increasing temperatures but still dry conditions), (b) sub-tropical humid forest (interglacial with maximum temperature and precipitation), (c) highaltitude coniferous forest (transitional phase with cooler but still humid conditions), and finally (d) expansion of open vegetation, including steppe taxa (full glacial phase with cooler and dry conditions). sometimes the first (a) or the last (d) one can be absent, as described by combourieu-nebout (1993) at semaforo. during the late pleistocene the pattern shows the following four main subzones: (a) pioneer forest, (b) mixed temperate forest (interglacial with maximum temperature and precipitation), (c) high-altitude coniferous forest (transitional phase with cooler but still humid conditions), and finally (d) expansion of open vegetation. pattern 2 is expressed by fluctuations between altitudinal coniferous forests and thermophilous forests; it was observed in many records from the northern ap 103 fig. 8 the selected piacenzian and pleistocene pollen records summarized according to chronology, geographical location (north and south) and type of sedimentary succession (marine vs terrestrial). piacenzian to pleistocene flora and vegetation in italy 104 bertini a., combourien-nebout n. tab. 2 summary information on piacenzian and pleistocene pollen flora and vegetation. from the left: informal vegetation groups, main floristic taxa, their modern and climate ecology, vegetation images, optical microscope images of selected fossil pollen grains (not to scale). 105 fig. 9 glacial/interglacial cycles: summary of vegetation and climate evidence. pattern 1: gelasian-calabrian theoretical cycle. pattern 1’: end of chibanian and late pleistocene theoretical cycle. pattern 2: northern apennines (e.g. lona & bertoldi, 1972; bertini, 2001). pattern 3a (e.g. bertoldi et al., 1989) and pattern 3b (e.g. capraro et al., 2005) both described for the southern italian sites. see text for detail. tab. 3 main floristic, vegetal and climate evidence according to glacial/interglacial phases between the late piacenzian and the late pleistocene. piacenzian to pleistocene flora and vegetation in italy ennines (e.g. stirone, castell’arquato, monte falconerio crevalese, val marecchia). when comparing the theoretical cycle of semaforo with those described for stirone (bertini, 2001) and for lamone (fusco, 2007), pattern 2 seems to correspond to pattern 1 when its subzone (d) is lacking or extremely reduced. patterns 3a and 3b are both expressed by fluctuations between thermophilous forest and open vegetation describing humid glacials and dry interglacials according to the pollen records from some southern sites (e.g. bertoldi et al., 1989; capraro et al., 2005), as already addressed in 4.2.1-4.2.3. according to this evidence, steppe (i.e. arid conditions) should not be connected to glacial maxima without independent supporting data. consequently, the role of orbital signatures on longterm vegetation patterns in the mediterranean needs to be attentively evaluated before proposing terrestrial chronologies through astronomical tuning of vegetational phases. an explanation for patterns 3a and 3b may lie in the interplay between local factors and the effects of obliquity related warm/humid-cold/dry “interglacial” “glacial” cycles superimposed by precession related warm/dry-cold/humid cycles, as proposed by klotz et al. (2006) and joannin et al. (2007). 5.3. pollen and quaternary stratigraphy italy is very rich in late neogene and quaternary sites with many of them having a significant role in chronostratigraphy. fig. 10 shows the gssp from 3.6 ma to 0.0117 ka and the main coeval italian pollen sites; the locations of some of them correspond exactly with a type-locality (in bold in the figure, e.g. vrica). palynology is a powerful tool not only in the area of palaeoclimatic and palaeoenvironmental reconstructions but also with respect to the stratigraphic issues. however, this requires appropriate application of the stratigraphic principles in the interpretation of the significance of pollen zones. the fact that it is almost impossible to identify first appearance events, as well as to exactly trace the time-transgressive extinction of pollen taxa, complicates the use of the pollen content in describing biozones (except for assemblage and acme zones) or climatostratigraphic units, especially when they lack a solid chronostratigraphic framework. the ecobiostratigraphic events associated with the pliocene and pleistocene pollen zones need to be integrated with timediagnostic (e.g. magnetostratigraphy and tephrostratigraphy) and/or other biological marine or continental evidence in order to render them chronologically significant. in the past, palynostratigraphic correlations were often established according to the idea that the same or similar pollen (assemblage) zones in different sites can identify synchronous pollen signals, e.g. those based on the disappearance of “taxodiaceae” (i.e. tiberian phase and boundary; lona et al., 1969; lona & bertoldi, 1972), or those based on the northern european pollen stratigraphy (e.g. zagwijn, 1957, 1959, 1960, 1963, de jong, 1988). such interpretations, which assigned chronostratigraphic significance to ecobiostratigraphic events, produced a clear misunderstanding between biostrati 106 bertini a., combourien-nebout n. fig. 10 piacenzian and pleistocene gssp. on the right, the stratigraphical distribution of selected pollen sites corresponding or correlative to the gssp locations. (modified from cohen et al., 2013; updated). the ics international chronostratigraphic chart. episodes 36, 199-204 (online version 2022/10). graphic and chronostratigraphic principles and consequent mistakes in the establishment of correlations, also at regional scale, between different sites. for example, the “tiberian boundary (and phase)” was identified in the lacustrine pietrafitta succession with the sudden disappearance of taxodium pollen type directly after an acme phase according to lona et al. (1969) and lona (1971). previous authors also postulated the coincidence of the tiberian boundary with the former pliopleistocene boundary (1.8 ma). later, the tiberian boundary was also recognized in the marine section of stirone (lona et al., 1969, lona & bertoldi, 1972) and at the marker bed, in the controversial marine section of le castella (bertoldi, 1977). in the upper valdarno, a marked decrease in taxodium type pollen, after an acme phase, was also observed close to 1.8 ma (napoleone et al., 2003). however, further evidence demonstrates: 1. recurrent sudden falls in the pollen percentages of “taxodiaceae” throughout the gelasian; and 2. the persistence of “taxodiaceae” after 1.8 ma in many italian sites (e.g. becker-platen et al., 1977; bertolani marchetti et al., 1979; combourieu-nebout, 1993, 1995; ravazzi & rossignol-strick, 1995; fusco, 1996, 2007, 2010; bertini, 2001). the “taxodiaceae” stratigraphical range demonstrates that their disappearance cannot be considered as a synchronous and sudden event matching exactly the former plio-pleistocene boundary at 1.8 ma. it is therefore impossible to use the tiberian boundary to cross-correlate italian successions. the establishment of wide-scale correlations is even more difficult, on this basis: see, for instance, the correlation of the tiberian boundary with the reuverian/ pretiglian transition of the netherlands (zagwijn, 1975) proposed by lona (1971). the reuverian/pretiglian transition corresponds on the basis of chronostratigraphical evidence, to the piacenzian/gelasian boundary (at ca. 2.6 ma) and not to the gelasian/calabrian transition (at 1.8 ma). north-western european continental “stages” (e.g. zagwijn, 1957, 1959, 1960, 1963; de jong, 1988) summarized in zagwijn & hager (1987) and zagwijn (1992) have represented a significant standard in continental neogene stratigraphy. however, their validity, and their use by many authors, e.g. for long-distance chronostratigraphic correlations or to establish chronostratigraphical frameworks, have been criticized conceptually and methodologically (e.g. bertini, 2003; leroy, 2007). substantial revisions were carried out by drees (2005), donders et al. (2007), and kemna & westerhoff (2007). all previous reflections do not reduce the stratigraphical potential of palynology for the study of the late neogene and quaternary. on the contrary, palynology, when correctly applied, is a very powerful tool for stratigraphic and palaeoenvironmental reconstructions, all the more so because, in contrast to other fossils, palynomorphs, being contained in both marine and non-marine sediments, permit direct correlation of onshore and offshore successions (e.g. combourieu-nebout & vergnaud-grazzini, 1991; capraro et al., 2005; joannin et al., 2007; joannin et al., 2008; bertini et al., 2010). 5.4. palaeoclimate change, palaeonvironments and human migration the great abundance of pollen records allows for a coherent spatial and temporal framework of the palaeoenvironmental scenarios during successive pleistocene g/i cycles. this information is also fundamental to understanding the role of climate in the migration and subsequent colonization of the genus homo (e.g. dennell et al., 2011; manzi et al., 2011; messager et al., 2011 and references therein). chronologically wellconstrained pollen records have been included in databases and have often contributed to climate quantification too, contributing to the compilation of regional to continental-scale palaeogeographic maps and the identification of the most likely migration routes for hominin expansion and settlement (e.g. muttoni et al., 2010, 2018; moncel et al., 2018; sànchez goñi, 2022 and references therein). the beginning of the empt which follows several migration attempts can be taken to represent the first undisputed and well-dated phases of human colonization in europe (e.g. head & gibbard, 2005; head et al., 2008; muttoni et al., 2010, 2018; o'regan et al., 2011; abbate and sagri, 2012). it includes the last obliquity-forced climate cycles, when hominins spread from africa to the eurasian continent (e.g. dennell et al., 2011 and references therein). according to some authors (e.g. leroy et al., 2011), the early pleistocene interval could provide the latest best narrow windows of opportunity for hominins to disperse into europe during the transition from glacial to interglacial periods, the full glacials being too cold for them and the interglacial to glacial transition too forested, although this has not yet been demonstrated. what is more evident is the increasing imprint of human populations after the late pleistocene and up to the present-day. the opportunity to better understand the behaviour of the natural vegetation and its adaptation to climate changes in earlier periods may help to develop strategies for sustainable conservation of vegetation in the future. 6. conclusions the overall pollen record allows us to trace the main vegetational features linked to the complex mosaic of different physiographic and climatic conditions of the italian peninsula between ca 3.6 ma and 0.117 ka i.e. preceding the main holocene human impact on the landscape. pollen evidence is chronologically well constrained because it is found on sites that are well calibrated through the use of time-diagnostic tools e.g. magnetostratigraphy, micropalaeontology, biochronology, radiometric dating methods (u/th, 14 c, …) and varve chronology. this approach allows palynologists to address the main scientific stratigraphic and biological issues for the quaternary. particularly relevant is the documentation of the flora and vegetation response to both milankovitch cycles and sub-millennial events. moreover, this set of evidence provides indispensable information for a better comprehension of topics which become crucial during the holocene, i.e human versus natural climate 107 piacenzian to pleistocene flora and vegetation in italy factors, location and extent of the glacial refugia for temperate and mediterranean species, modern floristic richness and genetic diversity. this summary illustrates the behaviour of italian vegetation in the face of natural climatic changes through ancient times and in the absence of any human influence; the aim is to contribute to predictions regarding the future of mediterranean vegetation under ongoing climate changes. acknowledgements authors thank the university of firenze and the cnrs (centre national de la recherche scientifique) for providing financial support for their researches and the erasmus program for the possibilities of exchanges between the two laboratories. references abbate e., sagri m. (2012) early to middle pleistocene homo dispersals from africa to eurasia: geological, climatic and environmental constraints. quaternary international, 267, 3-19. albianelli a. bertini a., magi m., napoleone g., sagri m. (1995) ii bacino pliopleistocenico del valdarno superiore: eventi deposizionali, paleomagnetici e paleoclimatici. ii quaternario (ital. j. quat. sci.), 8 (1), 11-18. allen j.r.m., huntley b. (2000) weichselian palynological records from southern europe: correlation and chronology. quaternary international, 73 (74), 111125. allen j.r.m., huntley b. (2009) last interglacial palaeovegetation, palaeoenvironments and chronology: a new record from lago grande di monticchio, southern italy. quaternary science review, 28, 1521-1538. amato v., aucelli p.p.c., cesarano m., pappone g., rosskopf c.m., russo ermolli e. (2011) the sessano intra-montane basin: new multi-proxy data for the quaternary evolution of the molise sector of the central-southern apennines (italy). geomorphology, 128, 15-31. amorosi a., colalongo m.l., fiorini f., fusco f., pasini g., vaiani s.c., sarti g. (2004) palaeogeographic and palaeoclimatic evolution of the po plain from 150ky core records. global and planetary change, 40 (1-2), 55-78. arias c., bigazzi g., bonadonna f.p., iaccarino s., urban b., dal molin m., dal monte l., martolini m. (1990) valle ricca late neogene stratigraphy (lazio region, central italy). paléobiologie continentale, 17, 61-68. aucelli p., amato v., cesarano m., pappone g., rosskopf c.m., russo ermolli e., scarciglia f. (2011) new morphostratigraphic and chronological constraints for the quaternary palaeosurfaces of the molise apennines (southern italy). geologica carpathica, 62, 17-26. badino f., pini r., bertuletti p., ravazzi, c., delmonte b., monegato g., reimer p., vallé f., arrighi s., bortolini e., figus c., lugli f., maggi v., marciani g., margaritora d., oxilia g., silvestrini s., benazzi s. (2020a) the fast-acting “pulse” of heinrich stadial 3 in a mid-latitude boreal ecosystem. scientific reports, 10(1), 18031. badino f., pini r., ravazzi c., margaritora d., arrighi s., bortolini e., figus s., giaccio b., lugli f., marciani g., monegato g., moroni a., negrino f., oxili g., peresani m., romandini m., ronchitelli a., spinapolice e., zerboni a., benazzi s. (2020b) an overview of alpine and mediterranean palaeogeography, terrestrial ecosystems and climate history during mis 3 with focus on the middle to upper palaeolithic transition. quaternary international, 551, 7-28. baggioni m., suc j.-s., vernet j.l. (1981) le pliopléistocène de camerota (italie méridionale): géomorphologie et paléoflores. geobios 14, 229237. bartoli g., hönisch b., zeebe r.e. (2011) atmospheric co2 decline during the pliocene intensification of northern hemisphere glaciations. paleoceanography, 26(4). basilici g. (1997) sedimentary facies in an extensional and deep lacustrine depositional system: the pliocene tiberino basin, central italy. sedimentology, 109, 73-94. becker-platen j.d., benda l., cepek p., daniels c.h.v., mengeling h., meyer k.j., steffens p., streif h., vinken r. (1977) beiträge zur pliopleistozän-grenzziehung in mittelitalien. giornale di geologia, 41, 107-114. belluomini g., manfra l., palombo m.r. (1997) a recent aminochronology of pleistocene mammals from rome area and isernia-la pineta deposits (italy). geologica romana, 33, 73-79. benvenuti m., degli innocenti d. (2001) the pliocene deposits in the central-eastern valdelsa basin (florence, italy) revised through facies analysis and unconformity-bounded stratigraphic units. rivista italiana di paleontologia e stratigrafia, 107, 265-286. benvenuti m., bertini a., conti c., dominici s. (2007) integrated analyses of litho and bio-facies in a pliocene cyclothemic, alluvial to shallow marine succession (tuscany, italy). geobios, 40 (2), 143158. berger a.m., loutre m.f. (1991) insolation values for the climate of the last 10 million of years. quaternary science review, 10 (4), 297-317. doi: 10.1016/02773791(91)90033-q bertini a. (1994) messinian-zanclean vegetation and climate in north-central italy. historical biology, 9, 3-10. bertini a. (2000) pollen record from colle curti and cesi: early and middle pleistocene mammal sites in the umbro-marchean apennine mountains (central italy). journal of quaternary sciences, 15, 825-840. bertini a. (2001) pliocene climatic cycles and altitudinal forest development from 2.7 ma in the northern apennines (italy): evidence from the pollen record of the stirone section (~5.1 to ca. 2.2 ma). 108 bertini a., combourien-nebout n. geobios 34, 253-265. bertini a. (2002) palynological evidence of late neogene environments in italy. acta universitatis carolinae, geologica, 46, 15-25. bertini a. (2003) early to middle pleistocene changes of the italian flora and vegetation in the light of a chronostratigraphic framework. ii quaternario (ital. j. quat. sci.) 16, 19-36. bertini a. (2010) pliocene to pleistocene palynoflora and vegetation in italy: state of the art. quaternary international, 225, 5-24. bertini a. (2013) climate and vegetation in the upper valdarno basin (central italy) as a response to northern hemisphere insolation forcing and regional tectonics in the late pliocene-early pleistocene. italian journal of geosciences,132, 137148. bertini a., roiron p. (1997) evolution de la végétation et du climat pendant le pliocène moyen en italie centrale: apport de la palynologie et des macroflores à l'étude du bassin du valdarno supérieur (coupe de santa barbara). comptes rendus de l'académie des sciences paris, 324, 763-771. bertini a., martinetto e. (2008) messinian to zanclean vegetation and climate of northern and central italy. bollettino della società paleontologica italiana, 47, 105-121. bertini a., martinetto e. (2011) reconstruction of vegetation transects for the messinian-piacenzian of italy by means of comparative analysis of pollen, leaf and carpological records. palaeogeography palaeoclimatology palaeoecology, 304, 230-246. bertini a., londeix l., maniscalco r., di stefano a., suc j.p., clauzon g., gautier f., grasso m. (1998) paleobiological evidence of depositional conditions in the salt member, gessoso-solfifera formation (messinian, upper miocene) of sicily. micropaleontology 44 (4), 413-433. bertini a., ciaranfi n., marino m., palombo m.r. (2010) proposal for pliocene and pleistocene land-sea correlation in the italian area. quaternary international, 219, 95-108. bertini a., magri d., martinetto e., sadori l., vassio e. (2014) la flora del pleistocene dell’italia centrale. the pleistocene flora of central italy. in: kustatscher e., roghi g., bertini a., miola a. (eds.): la storia delle piante fossili in italia. paleobotany of italy. pubblicato in occasione del xi congresso europeo di paleobotanica, padova, 26-31 agosto 2014. pubblicazione del museo di scienze naturali dell’alto adige n. 9, 308-328. isbn 9788887108064 bertini a., toti f., marino m., ciaranfi n. (2015) vegetation and climate across the early-middle pleistocene transition at montalbano jonico, southern italy. quaternary international, 383, 74-88. bertini a., piccini l., ricci m., massini m. (2022) palynological evidence of middle pleistocene palaeoenvironmental changes from the ‘buca dell’onice’ flowstone (alpi apuane, central italy). the depositional record, 8(1), 340-354. bertolani-marchetti d., accorsi c.a., pelosio g., raffi s. (1979) palynology and stratigraphy of the pliopleistocene sequence of the stirone river (northern italy). pollen et spores, 21, 149-167. bertoldi r. (1977) studio palinologico della serie di le castella (calabria). atti accademia nazionale dei lincei, 62 (4), 535-547. bertoldi r. (1985a) palinostratigrafia in sedimenti marini del pliocene della sicilia e considerazioni paleoclimatiche. atti accademia nazionale dei lincei, 78, 157-164. bertoldi r. (1985b) testimonianze palinologiche di età “villafranchiana” nel deposito fluvio-lacustre di compiano (alta val di taro). acta naturalia dell’ateneo parmense, 21, 23-30. bertoldi r. (1988) una sequenza palinologica di età rusciniana nei sedimenti lacustri basali del bacino di aulla-olivola. rivista italiana di paleontologia e stratigrafia, 94, 105-138. bertoldi r., castello f. (1990) palinoflora di età villafranchiana inferiore nel deposito continentale di sesta godano in val di vara (bacino del f. magra). atti della società toscana di scienze naturali, 97, 31-45. bertoldi r., rio d., thunell r. (1989) pliocenepleistocene vegetational and climatic evolution of the south-central mediterranean. palaeogeography palaeoclimatology palaeoecology, 72, 263275. bertoldi r., binotti a., castello f. (1994) reevesia and itea in the pollen flora of the upper neogene continental deposit at sarzana (lower magra valley, northern italy). review palaeobotany and palynology, 80, 159-172. blasi c. (2010) la vegetazione d'italia con carta delle serie di vegetazione in scala 1:500.000. palombi editore, rome, italy, pp. 536. bonin g. (1981) l'étagement de la végétation dans l'appenin méridional. ecologie mediterranéenne 7, 79-91. borzi m., carboni m.g., di bella l., florindo f., girotti o., piccardi e., sagnotti l. (1998) bioand magneto-stratigraphy in the tiber valley revised. quaternary international 47 (48), 65-72. bossio a., costantini a., lazzaretto a., lotta d., mazzanti r., mazzei r., salvatorini g., sandrelli f. (1993) rassegna delle conoscenze sulla stratigrafia del neoautoctono toscano. memorie della società geologica italiana, 49, 17-98. brauer a., mingram j., frank u., gunter c., schettler g., wulf s., zolitschka b., negendank j.f.w. (2000) abrupt environmental oscillations during the early weichselian recorded at lago grande di monticchio, southern italy. quaternary international, 73 (74), 79-90. brauer a., allen j.r.m., mingram j., dulski p., wulf s., huntley b. (2007a) evidence for last interglacial chronology and environmental change from southern europe. proceedings of the national academy of sciences, 104, 450-455. brauer a., wulf s., mangili c., moscariello a. (2007b) tephrochronological dating of varved interglacial lake deposits from piànico-sèllere (southern alps, 109 piacenzian to pleistocene flora and vegetation in italy italy) to around 400 ka. journal of quaternary sciences, 22, 85-96. brauer a., mangili c., moscariello a., witt a. (2008) palaeoclimatic implications from micro-facies data of a 5900 varves time series from the piànico interglacial sediment record, southern alps. palaeogeography palaeoclimatology palaeoecology, 259, 121-135. brenac p. (1984) végétation et climat de la campanie du sud (italie) au pliocène final d'après l'analyse pollinique des dépots de camerota. ecologie mediterranéenne, 10, 207-216. brolsma m.j. (1978) quantitative foraminiferal analysis and environmental interpretation of the pliocene and topmost miocene on the south coast of sicily. utrecht micropaleontological bullettins, 18, 159. brunsfeld s.j., soltis p.e., soltis d.e., gedek p.a., quinn c.j., strenge d.d., ranker t.a. (1994) phylogenetic relationships among the genera of taxodiaceae and cupressaceae: evidence from rbcl sequences. systematic botany, 19 (2), 253262. buccheri g., capretto g., di donato v., esposito p., ferruzza g., pescatore t., russo ermolli e., senatore m.r., sprovieri m., bertoldo m., carella d., madonia g. (2002) a high resolution record of the last deglaciation in the southern tyrrhenian sea: environmental and climatic evolution. marine geology, 115, 1-24. canali g., capraro l., donnici s., rizzetto f., serandrei -barbero r., tosi l. (2007) vegetational and environmental changes in the eastern venetian coastal plain (northern italy) over the past 80,000 years. palaeogeography palaeoclimatolology palaeoecology, 253, 300-316. capraro l., asioli a., backman j., bertoldi r., channell j.e.t., massari f., rio d. (2005) climatic patterns revealed by pollen and oxygen isotope records across the matuyama brunhes boundary in the central mediterranean (southern italy). in: head m.d., gibbard p.l. (eds.), early-middle pleistocene transition: the land-ocean evidence. geological society of london spec. publ. 247, 159-182. capraro l., macrì p., scarponi d., rio d. (2015) the lower to middle pleistocene valle di manche section (calabria, southern italy): state of the art and current advances. quaternary international, 383, 36-46. capraro l., ferretti p., macrì p., scarponi, d., tateo f., fornaciari e., bellini g., dalan g. (2017) the valle di manche section (calabria, southern italy): a high resolution record of the early-middle pleistocene transition (mis 21-mis 19) in the central mediterranean. quaternary science reviews, 165, 31-48. capraro l., bonomo s., di stefano a., ferretti p., fornaciari e., galeotti s., incarbona a., macrì p., raffi i., sabatino n., speranza f., sprovieri m., di stefano e., sprovieri r., rio d. (2022) the monte san nicola section (sicily) revisited: a potential unit-stratotype of the gelasian stage. quaternary science reviews, 278, 107367. carminati e., doglioni c. (2012) alps vs. apennines: the paradigm of a tectonically asymmetric earth. earth-science reviews, 112(1-2), 67-96. carraro f., ambrosetti p., angela-franchini m., azzaroli a., basilici g., belluomini g., bertoldi r., boano p., bormioli d., campanino f., caramiello r., cerasoli m., ciangherotti a., compagnoni r., esu d., ferrero e., ficcarelli g., forno m.g., genovese g., giardino m., girotti o., gliozzi e., lanza r., mai d., manfra l., martinetto e., masini f., moscariello a., pavia g., perotto a., polino r., sala b., siniscalco c., torre d., violanti d. (1996) revisione del villafranchiano nell'area tipo di villafranca d'asti. il quaternario (ital. j. geosci.), 9, 5-120. caruso a. (2004) climatic changes during late pliocene and early pleistocene at capo rossello (sicily, italy): response from planktonic foraminifera. in: coccioni r., galeotti s., lirer f. (eds.), proceedings of the first italian meeting on environmental micropaleontology. grzybowski foundation special publication 9, pp. 17-36. castradori d., rio d., hilgen f.j., lourens l.j. (1998) the global standard stratotype section and point (gssp) of the piacenzian stage (middle pliocene). episodes, 21, 88-93. chiarini e., giardini m., la posta e., papasodaro f., sadori l. (2007) sedimentology, palynology and new geochronological constraints on quaternary deposits of the corvaro intermontane basin (central italy). review of micropaleontology, 50, 309-314. chiarini e., giardini m., mattei m., papasodaro f., porreca m., sadori l. (2009) plio-quaternary evolution of the high salto river valley: the marano de' marsi unit. il quaternario (ital. j. quat. sci.) 22 (2), 325-344. cita m.b., gartner s. (1973) studi sul pliocene e sugli strati di passaggio dal miocene al pliocene. v. the stratotype zanclean. foraminiferal and nannofossil biostratigraphy. rivista italiana di paleontologia e stratigrafia, 79, 503-558. cita m.b., capraro l., ciaranfi n., di stefano e., lirer f., maiorano p., marino m., raffi i., rio d., sprovieri r., stefanelli s., vai g.b. (2008) the calabrian stage redefined. episodes, 31, 408419. clauzon g., suc j. p., gautier f., berger a., loutre m. f. (1996) alternate interpretation of the messinian salinity crisis: controversy resolved? geology, 24(4), 363-366. cohen k.m., finney s.c., gibbard p.l., fan, j.x. (2013; updated) the ics international chronostratigraphic chart. episodes, 36, 199-204. (online version 2022/10). cohen k., gibbard p. (2022) global chronostratigraphical correlation table for the last 2.7 million years v. 2019 (poster version). mendeley data, v5. doi: 10.17632/dtsn3xn3n6.5 coltorti m., albianelli a., bertini a., ficcarelli g., laurenzi m.a., napoleon g., torre d. (1998) the colle curti mammal site in the colfiorito area 110 bertini a., combourien-nebout n. (umbria-marchean apennine, italy): geomorphology, stratigraphy, paleomagnetism and palynology. quaternary international, 46 (48), 107-116. combourieu-nebout n. (1993) vegetation response to upper pliocene glacial/interglacial cyclicity in the central mediterranean. quaternary research, 40, 228-236. combourieu-nebout n. (1995) réponse de la végétation de l'italie méridionale au seuil climatique de la fin du pliocène d'après l'analyse pollinique haute résolution de la section de semaforo (2,46 à 2.1 ma). comptes rendus de l'académie des sciences paris, 321, 659-665. combourieu-nebout n., vergnaud-grazzini c. (1991) late pliocene northern hemisphere glaciations: the continental and marine responses in the central mediterranean. quaternary sciences review, 10, 319-334. combourieu-nebout n., semah f., djubiantono t. (1990) la limite pliocène/pléistocène: précisions magnétostratigraphiques par l'étude sériée de la coupe type de vrica (crotone, italie). comptes rendus de l'académie des sciences paris, 311, 851-857. combourieu-nebout n., siani g., paterne m., turon j.l. (1998) a high resolution record of the last deglaciation in the central mediterranean sea: palaeovegetation and palaeohydrological evolution. quaternary sciences review, 17, 3-4. combourieu-nebout n., fauquette s., quézel p. (2000) what was the late pliocene mediterranean climate like: a preliminary quantification from vegetation. bulletin de la société géologique de france, 171, 271-277. combourieu-nebout, n., turon j.l., zhan r., capotondi l., londeix l., pahnke k. (2002) enhanced aridity and atmospheric high-pressure stability over the western mediterranean during the north atlantic cold event of the past 50 ky. geology, 30, 863866. combourieu-nebout n., foucault a., mélières f. (2004) vegetation markers of palaeoclimate cyclical changes in the pliocene of punta piccola (sicily, italy). palaeogeography palaeoclimatolology palaeoecology, 214 (1-2), 55-66. combourieu-nebout n., peyron o., bout-roumazeille v., goring s., dormoy i., joannin s., sadori l., siani g., magny m. (2013) holocene vegetation and climate changes in central mediterranean inferred from a high-resolution marine pollen record (adriatic sea). climate of the past 9, 20232042. combourieu-nebout n., bertini a., russo ermolli e., peyron o., klotz s., montade v., fauquette s., allen j.r.m., fusco f., goring s. huntley b., joannin s., lebreton v., magri d., martinetto e., orain r., sadori, l. (2015) climate changes in the central mediterranean and italian vegetation dynamics since the pliocene. review of palaeobotany and palynology, 218, 127-147. corrado p., magri d. (2011) a late early pleistocene pollen record from fontana ranuccio (central italy). ii quaternario (j. quat. sci.) 26, 335-344. cosentino d., asti r., nocentin m., gliozzi e., kotsakis t., mattei m., esu d., spadi m., tallini m., cifelli f., pennacchioni m., cavuoto g., di fiore, v. (2017) new insights into the onset and evolution of the central apennine extensional intermontane basins based on the tectonically active l’aquila basin (central italy). gsa bulletin, 129(9-10), 1314-1336. cremaschi m. (1983) la serie pleistocenica di isernia la pineta (molise) e la posizione stratigrafica dei suoli d'abitato paleolitici in essa inclusi. in: peretto c., terzan, c., cremaschi m. (eds.), isernia la pineta, un accampamento più antico di 700 000 anni. calderini, bologna, 49-62. cremaschi m., peretto c. (1988) les sols d'habitat du site paléo-lithique d'isernia la pineta (molise, italie centrale). l'anthropologie 92, 1017-1040. cremaschi m., ravazzi c. (1995) nuovi dati stratigrafici e geocronologici sul bacino di leffe (prealpi lombarde, bergamo). ii quaternario (j. quat. sci.), 8(1), 167-182. de beaulieu j.l., andrieu-ponel v., cheddadi r., guiter f., ravazzi c., reille m., rossi s. (2006) apport des longues séquences lacustres à la connaissance des variations des climats et des paysages pléistocènes. comptes rendus palevol, 5, 65-72. de jong j. (1988) climatic variability during the past three million years, as indicated by vegetational evolution in northwest europe and with emphasis on data from the netherlands. philosophical transactions of the royal society of london b 318, 603-617. de la vega e., chalk t.b., wilson p.a., bysani r.p., foster, g. l. (2020) atmospheric co2 during the mid-piacenzian warm period and the m2 glaciation. scientific reports, 10(1), 1-8. de la vega e., chalk t.b., wilson p.a., bysani r.p., foster g. l. (2021) author correction: atmospheric co2 during the mid-piacenzian warm period and the m2 glaciation. scientific reports, 11 (1), 1-4. de schepper s., groeneveld j., naafs, b.d.a., van renterghem c., hennissen j., head m.j., louwye s., fabian k. (2013) northern hemisphere glaciation during the globally warm early late pliocene. plos one, 8(12), e81508. delitala m.c., fornaseri m., nicoletti m. (1983) datazioni argon-potassio sulla serie pleistocenica di isernia la pineta. in: peretto, c., terzani, c., cremaschi, m. (eds.), isernia la pineta, un accapamento più antico di 700.000 anni. calderini, bologna, 65-66. dennell r.w., martinon torres m., bermudez de castro j.m. (2011) hominin variability, climatic instability and population demography in middle pleistocene europe. quaternary science reviews, 30, 15111524. desprat s., combourieu-nebout n., essallami l., sicre m.a., dormoy i., peyron o., siani g., bout roumazeilles v., turon j.l. (2013) deglacial and holocene vegetation and climatic changes at the southernmost tip of the central mediterranean from a direct land-sea correlation. climate of the 111 piacenzian to pleistocene flora and vegetation in italy past, 9, 767-787. di bella l., carbonia m.g., bergamin l., iamund f. (2005) the early pleistocene in latium (central italy): palaeoecology from benthic foraminiferal record. quaternary international, 131, 23-34. di donato v., esposito p., russo ermolli e., scarano a., cheddadi r. (2008) coupled atmospheric and marine palaeoclimatic reconstruction for the last 35 ka in the sele plain-gulf of salerno area (southern italy). quaternary international, 190, 146-157. di rita f., sottili g. (2019) pollen analysis and tephrochronology of a mis 13 lacustrine succession from eastern sabatini volcanic district (rignano flaminio, central italy). quaternary science reviews, 204, 78-93. di rita f., anzidei a.p., magri d. (2013) a late glacial and early holocene pollen record from valle di castiglione (rome): vegetation dynamics and climate implications. quaternary international, 288, 73-80. donders t.h., kloosterboer-van hoeve m.l., westerhoff w., verreussel r.m.c.h., lotter a.f. (2007) late neogene continental stages in nw europe revisited. earth-science reviews, 85, 161186. drees m. (2005) an evaluation of the early pleistocene chronology of the netherlands. vertebrate palaeontology, 1, 1-46. www.palarch.nl dowsett h.j., robinson m.m., haywood a.m., hill d.j., dolan a.m., stoll d.k., le chan w., abe-ouchi a., chandler m.a., rosenbloom n.a., otto-bliesner b.l., bragg jf.g., lunt d.j, foley k.m., riesselman, c.r. (2012) assessing confidence in pliocene sea surface temperatures to evaluate predictive models. nature climate change, 2(5), 365-371. dubois j.m. (2001) cycles climatiques et paramètres orbitaux vers 1 ma. etude de la coupe de monte san giorgio (caltagirone, sicile): palynologie, isotope stables, calcimétrie. mémoire dea. lyon university, lyon, france. farjon a. (1998) world checklist and bibliography of conifers. royal botanical gardens, kew, richmond, u.k. farjon a. (2005) a monograph of cupressaceae and sciadopitys. royal botanic gardens, kew, uk 1842460684. fauquette s., bertini a. (2003) quantification of northern italy pliocene climate from pollen data: evidences for a very peculiar climate pattern. boreas, 32, 361-369. fauquette s., combourieu-nebout n. (2013) palaeoaltitude of the sila massif (southern apennines, italy) and distribution of the vegetation belts at ca. 2.4 ma (early pleistocene). review of palaeobotany and palynology, 189, 1-7. favaretto s., asioli a., miola a., piva a. (2008) preboreal climatic oscillations recorded by pollen and foraminifera in the southern adriatic sea. quaternary international, 190, 89-102. federici p.r. (1973) la tettonica recente dell'appennino 1. il bacino villafranchiano di sarzana e il suo significato nel quadro dei movimenti distensivi a nord-ovest delle alpi apuane. bollettino della società geologica italiana, 92, 287-301. ficcarelli g., abbazzi l., albianelli a., bertini a., coltorti m., magnatti m., masini f., mazza p., mezzabotta c., napoleone g., rook l., rustioni m., torre d. (1997) cesi an early middle pleistocene site in the colfiorito basin (umbro-marchean apennine), central italy. journal of quaternary science, 12, 507-518. fidolini f., ghinassi m., magi m., papini m., sagri m. (2013) the plio-pleistocene fluvio-lacustrine upper valdarno basin (central italy): stratigraphy and basin fill evolution. italian journal of geosciences, 132(1), 13-32. follieri m. (1977) evidence on the plio-pleistocene palaeofloristic evolution in central italy. rivista italiana di paleontologia e stratigrafia, 83, 925930. follieri m., magri d., sadori l. (1988) 250,000-year pollen record from valle di castiglione (roma). pollen et spores 30, 329-356. follieri m., magri d., sadori l. (1989) pollen stratigraphical synthesis from valle di castiglione (roma). quaternary international, 3 (4), 81-84. follieri m., giardini m., magri d., sadori l. (1998) palynostratigraphy of the last glacial period in the volcanic region of central italy. quaternary international 47/48, 3-20. forno m. g., gattiglio m., comina c., barbero d., bertini a., doglione a., gianotti f., irace a., martinetto e., mottura a., sala b. (2015) stratigraphic and tectonic notes on the villafranca d’asti succession in type-area and castelnuovo don bosco sector (asti reliefs, piedmont). alpine and mediterranean quaternary (amq), 28 (1), 5-27. francavilla f., bertolani-marchetti d., tomadin l. (1970) ricerche stratigrafiche, sedimentologiche e palinologiche sul villafranchiano tipo. giornale di geologia 36 (02), 701-741. fusco f. (1996) analisi polliniche nelle successioni pleistoceniche inferiori della valle del lamone (appennino nord-orientale). evoluzione paleovegetazionale e paleoclimatica. unpublished phd thesis, university of bologna, italy), pp. 96. fusco f. (2007) vegetation response to early pleistocene climatic cycles in the lamone valley (northern apennines, italy). review of palaeobotany and palynology, 145, 1-23. fusco f. (2010) picea + tsuga pollen record as a mirror of oxygen isotope signal? an insight into the italian long pollen series from pliocene to early pleistocene. quaternary international, 225, 5874. ge.mi.na. (ed.) (1962) ligniti e torbe dell'italia continentale. società geomineraria nazionale, ilte ed. roma, italy. ghinassi m., magi m., sagri m., singer b.s. (2004) arid climate 2.5 ma in the plio-pleistocene valdarno basin (northern apennines, italy). palaeogeography palaeoclimatolology palaeoecology, 207, 37-57. 112 bertini a., combourien-nebout n. giunta s., negri a., morigi c., capotondi l., combourieu-nebout n., emeis k.c., sangiorgi f., vigliotti l. (2003) coccolithophorid ecostratigraphy and multi-proxy paleoceanographic reconstruction in the southern adriatic sea during the last deglacial time (core ad91-17). palaeogeography palaeoclimatolology palaeoecology, 190, 39-59. grieser j., gommes r., bernardi m. (2006) new locclim-the local climate estimator of fao. in geophysical research abstracts, 8, no. 08305, p. 2. guerrera f., coccioni d., corradini d., bertoldi r. (1984) caratteristiche lito-sedimentologiche e micropaleontologiche (foraminiferi, dinoflagellati, pollini e spore) di successioni “tripolacee” plioceniche del bacino di caltanisetta. bollettino della società geologica italiana, 103, 629-660. haywood a. m., valdes p. j. (2004) modelling middle pliocene warmth: contribution of atmosphere, oceans and cryosphere. earth planetary science letters, 218, 363-377. haywood a.m., hill d.j., dolan a.m., otto-bliesner b. l., bragg f., chan w.l., chandler m.a., contoux c., dowsett h.j., jost a., kamae y., lohmann g., lunt d.j., abe-ouchi a., pickering s.j., ramstein g., rosenbloom n.a., salzmann u., sohl l., stepanek c., ueda h., yan q., zhan z. (2013) large-scale features of pliocene climate: results from the pliocene model intercomparison project. climate of the past, 9(1), 191-209. head m.j., gibbard p.l. (2005) early-middle pleistocene transitions: an overview and recommendation for the defining boundary. geological society, london, special publications, 247(1), 1-18. head m.j., gibbard p.j. (2015) early-middle pleistocene transitions: linking terrestrial and marine realms. quaternary international, 389, 7-46. head m.j., gibbard p., salvador a. (2008) the quaternary: its character and definition. episodes journal of international geoscience, 31(2), 234238. hilgen f.j. (1987) sedimentary rhythms and highresolution chronostratigraphic correlations in the mediterranean pliocene. newsletters on stratigraphy, 17, 109-127. hilgen f.j., langereis c.g. (1988) the age of the miocene-pliocene boundary in the capo rossello area (sicily). earth and planetary science letters, 91, 214-222. howell m.w., thunell r., tappa, e., rio d., sprovieri r. (1988) late neogene laminated and opal-rich facies from the mediterranean region: geochemical evidence for mechanisms of formation. palaeogeography palaeoclimatology palaeoecology, 64, 265-286. joannin s., quillévéré f., suc j.p., lécuyer c., martineau f. (2007) early pleistocene climate changes in the central mediterranean region as inferred from integrated pollen and foraminiferal stable isotope analyses. quaternary research, 67, 264-274. joannin s., ciaranfi n., stefanelli s. (2008) vegetation changes during the late early pleistocene at montalbano jonico (province of matera, southern italy) based on pollen analysis. palaeogeography palaeoclimatology palaeoecology, 270, 92-101. karner d. b., juvigne e., brancaccio l., cinque a., russo ermolli e., santangelo n., bernasconi s., lirer, l. (1999) a potential early middle pleistocene tephrostratotype for the mediterranean basin: the vallo di diano, campania, italy. global and planetary change, 21(1-3), 1-15. kemna h.a., westerhoff w.e. (2007) remarks on the palynology-based chronostratigraphic subdivision of the pliocene terrestrial deposits in nw-europe. quaternary international, 164/165, 184-196. kent d.v., rio d., massari f., kukla g., lanci l. (2002) emergence of venice during the pleistocene. quaternary science review, 21, 1719-1727. klotz s., fauquette s., combourieu-nebout n., uhl d., suc j.p., mosbrugger v. (2006) seasonality intensification and long-term winter cooling as a part of the late pliocene climate development. earth planetary science letters, 241, 174-187. lang n., wolff e. w. (2011) interglacial and glacial variability from the last 800 ka in marine, ice and terrestrial archives. climate of the past, 7(2), 361380. lebreton v. (2002) végétation et climat au pléistocène inférieur et moyen à la pineta (isernia, italie). comptes rendus palevol, 1, 11-17. leroy s. (2007) progress in palynology of the gelasian-calabrian stages in europe: ten messages. review micropaleontology, 50, 293-308. leroy s., giralt s., francus p., seret g. (1996) the high sensitivity of the palynological record in the vico maar lacustrine sequence (latium, italy) highlights the climatic gradient through europe for the last 90 ka. quaternary science reviews, 15, 189-201. leroy s.a.g., arpe k., mikolajewicz u. (2011) vegetation context and climatic limits of the early pleistocene hominin dispersal in europe. quaternary science reviews, 30, 1448-1463. lisiecki l.e., raymo m.e. (2005) a pliocenepleistocene stack of 57 globally distributed benthic � 18o records. paleoceanography, 20, pa1003. doi: 10.1029/2004pa001071 lisiecki l.e., raymo m.e. (2007) plio-pleistocene climate evolution: trends and transitions in glacial cycle dynamics. quaternary science reviews, 26 (1-2), 56-69. lona f. (1950) contributi alla storia della vegetazione e del clima nella val padana e analisi pollinica del giacimento villafranchiano di leffe (bergamo). atti della società italiana di scienze naturali, 89, 123178. lona f. (1962) prime analisi pollinologiche sui depositi terziari e quaternari di castell'arquato: reperti di vegetazione da clima freddo sotto le formazioni calcaree a amphistegina. bollettino società geologica italiana, 81, 1-5. lona f. (1971) correlazioni tra alcune sequenze micropaleobotaniche plio-pleistoceniche continentali e marine dell’italia centro-settentrionale ed europa centro-occidentale con riferimento al limite tibe 113 piacenzian to pleistocene flora and vegetation in italy riano. l’ateneo parmense acta naturalia, 6, 145 -157. lona f., bertoldi r. (1972) la storia del pliopleistocene italiano in alcune sequenze vegetazionali lacustri e marine. atti accademia nazionale dei lincei, 11, 1-45. lona f., follieri m. (1957) successione pollinica della serie superiore (günz-mindel) di leffe (bergamo). veröffentlichungen des geobotanischen institutes der eidg. techn. hochschule, stiftung rübel zürich, 34, 86-98. lona f., ricciardi e. (1961a) studio pollinologico stratigrafico su una serie lacustre pleistocenica dell'italia centrale (bacino di gubbio, perugia). pollen et spores, 3, 93-100. lona f., ricciardi e. (1961b) reperti pollinologici nei depositi pleistocenici del bacino lacustre del mercure (italia meridionale, regione lucanocalabra). pollen et spores, 3(1), 85-92. lona f., bertoldi r., ricciardi e. (1969) pliopleistocenic boundary in italy based on the leffian and tiberian vegetational and climatological sequences. verlag nicht ermittelbar. lourens l., antonarakou f., hilgen f.j., van hoof a.m., vergnaud-grazzini c., zacharias w.j. (1996) evaluation of the plio-pleistocene astronomical timescale. paleoceanography, 11, 491-493. lourens l.j., hilgen f.j., laskar j., shackleton n.j., wilson d. (2004) the neogene period. in: gradstein, f.m., ogg, j.g., smith, a.g. (eds.), a geologic time scale 2004. cambridge university press, 409-440. magri d. (1999) late-quaternary vegetation history at lagaccione near lago di bolsena (central italy). review of palaeobotany and palynology, 106, 171 -208. magri d., sadori l. (1999) late pleistocene and holocene pollen stratigraphy at lago di vico (central italy). vegetation history and archaeobotany, 8, 247-260. magri d., palombo m.r. (2013) early to middle pleistocene dynamics of plant and mammal communities in south west europe. quaternary international, 288, 63-72. magri d., di rita f., palombo m.r. (2010) an early pleistocene interglacial record from an intermontane basin of central italy (scoppito, l'aquila). quaternary international, 225, 106-113. magri d., di rita f., aranbarri j., fletcher w., gonzález -sampériz p. (2017) quaternary disappearance of tree taxa from southern europe: timing and trends. quaternary science reviews, 163, 23-55. mai d.h. (1994) fossile koniferenreste in der meridionalen zone europas. feddes repertorium. 105(34), 207-227. mai d.h. (1995) paleocarpological investigations in the villafranchian (pliocene) of italy. bollettino del museo regionale di scienze naturali torino, 13, 407-437. manzi g., magri d., palombo m.r. (2011) early-middle pleistocene environmental changes and human evolution in the italian peninsula. quaternary science reviews, 30, 1420-1438. margari v., roucoux k., magri d., manzi g., tzedakis p.c. (2018) the mis 13 interglacial at ceprano, italy, in the context of middle pleistocene vegetation changes in southern europe. quaternary science reviews, 199, 144-158. marlow j. r., lange c. b., wefer g., rosell-melé a. (2000) upwelling intensification as part of the pliocene-pleistocene climate transition. science, 290(5500), 2288-2291. martinetto e. (2009) palaeoenvironmental significance of plant macrofossils from the piànico formation, middle pleistocene of lombardy, north italy. quaternary international, 204, 20-30. martinetto e., vassio e. (2010) reconstructing “plant community scenarios” by means of palaeocarpological data from the cenofita database, with an example from the ca' viettone site (pliocene, northern italy). quaternary international, 225 (1), 25-36. martinetto e., scardia g., varrone d. (2007) magnetobiostratigraphy of the stura di lanzo fossil forest succession (piedmont, italy). rivista italiana di paleontologia e stratigrafia, 113 (1), 109-125. martinetto e., bertini a., basilici g., baldanza a., bizzarri r., cherin m., gentili s., pontini m.r. (2014) the plant record of the dunarobba and pietrafitta sites in the plio-pleistocene palaeoenvironmental context of central italy. alpine mediterranean quaternary (amq), 27 (1), 29-72. martinetto e., monegato g., irace a., vaiani s.c., vassio e. (2015) pliocene and early pleistocene carpological records of terrestrial plants from the southern border of the po plain (northern italy). review of palaeobotany and palynology, 218, 148 -166. martini i.p., sagri m. (1993) tectono-sedimentary characteristics of late miocene-quaternary extensional basins of the northern apennines, italy. earth-science reviews, 34(3), 197-233. masini f., sala b. (2007) largeand small-mammal distribution patterns and chronostratigraphic boundaries from the late pliocene to the middle pleistocene of the italian peninsula. quaternary international, 160, 43-56. massari f., rio d., sgavetti m., prosser g., d'alessandro a., asioli a., capraro l., fornaciari e., tateo f. (2002) interplay between tectonics and glacio-eustasy: pleistocene succession of the crotone basin, calabria (southern italy). geological society american bullettin, 114, 1183-1209. massari f., rio d., serandrei barbero r., asioli a., capraro l., fornaciari e., vergerio p.p. (2004) the environment of venice area in the past two million years. palaeogeography palaeoclimatolology palaeoecology, 202, 273-308. masson-delmotte v., stenni b., pol k., braconnot p., cattani o., falourd s., kageyama m., jouzel j., landais a., minster b., barnola j.m., chappellaz j., krinner g., johnsen s., röthlisberger r., hansen j., mikolajewicz u., otto-bliesner b. (2010) epica dome c record of glacial and interglacial intensities. quaternary science reviews, 29(1-2), 113-128. 114 bertini a., combourien-nebout n. mcclymont e.l., sosdian s.m., rosell-melé a., rosenthal y. (2013) pleistocene sea-surface temperature evolution: early cooling, delayed glacial intensification, and implications for the midpleistocene climate transition. earth-science reviews, 123, 173-193. messager e., lebreton v., marquer l., russo ermolli, e. orain r., renault miskovsky j., lordkipanidze d., despriee j., peretto c., arzarello m. (2011) palaeoenvironments of early hominins in temperate and mediterranean eurasia: new palaeobotanical data from palaeolithic key-sites and synchronous natural sequences. quaternary science reviews, 30, 1439-1447. moncel m.h., landais a., lebreton v., combourieunebout n., nomade s., bazin l. (2018) linking environmental changes with human occupations between 900 and 400 ka in western europe. quaternary international, 480, 78-94. monegatti p., raffi s., raineri g. (1997) the monte falcone-rio riorzo composite section: biostratigraphic and ecobiostratigraphic remarks. bollettino della società paleontologica italiana, 36, 245260. monegatti p., canali g., bertoldi r., albianelli a. (2002) the classical late piacenzian monte falcone-rio crevalese section (northern italy): palynological evidence and biomagnetostratigraphic constraints for climatic cyclicity and local mollusc extinctions. geobios (mem. spéc.), 24, 219-227. moscariello a., ravazzi c., brauer a., mangili c., chiesa s., rossi s., de beaulieu j.l., reille m. (2000) a long lacustrine record from the piànicosèllere basin (middle-late pleistocene, northern italy). quaternary international, 73 (74), 47-68. mullenders w., favero v., coremans m., dirickx m. (1996) analyses pollinique de sondages à venise (ve-i, ve-i bis, ve-ii). aardkundige mededelingen, 7, 87-116. munno r., petrosino p., romano p., russo ermolli e., juvigné e. (2001) a late middle pleistocene climatic cycle in southern italy inferred from pollen analysis and tefrostratigraphy of the acerno lacustrine succession. géographie physique et quaternaire, 55, 87-99. muttoni g., carcano c., garzanti e., ghielmi m., piccin a., pini r., rogledi s., sciunnach d. (2003) onset of major pleistocene glaciations in the alps. geology, 31, 989-992. muttoni g., ravazzi c., breda m., pini r., laj c., kissel c., mazaud a., garzanti e. (2007) magnetostratigraphic dating of an intensification of glacial activity in the southern italian alps during marine isotope stage 22. quaternary research, 67, 161173. muttoni g., scardia g., kent d. v. (2010) human migration into europe during the late early pleistocene climate transition. palaeogeography palaeoclimatology palaeoecology, 296(1-2), 79-93. muttoni g., scardia g., kent d.v. (2018) early hominins in europe: the galerian migration hypothesis. quaternary science reviews, 180, 1-29. napoleone g., albianelli a., azzaroli a., bertini a., magi m., mazzini m. (2003) calibration of the upper valdarno basin to the plio-pleistocene for correlating the apennine continental sequences. ii quaternario (ital. j. quat. sci.), 16, 131-166. narcisi b., anselmi b. (1998) sedimentological investigations on a late-quaternary core from the lagaccione maar (central italy): palaeoclimatic and palaeoenvironmental inferences. quaternary international, 47/48, 21-28. narcisi b., anselmi b., catalano f., dai pra g., magri g. (1992) lithostratigraphy of the 250,000-year record of lacustrine sediments from the valle di castiglione crater, roma. quaternary science reviews, 11, 353-362. nomade s., bassinot f., marino m., simon q., dewilde f., maiorano p., isguder g., blamart d., girone a., scao v., pereira a., toti f., bertini a., combourieu-nebout n., peral m., bourlès, d.l., petrosino p., gallicchio s., ciaranfi n. (2019) high-resolution foraminifer stable isotope record of mis 19 at montalbano jonico, southern italy: a window into mediterranean climatic variability during a low-eccentricity interglacial. quaternary science reviews, 205, 106-125. orain r., lebreton v., russo ermolli e., combourieunebout n., sémah a.-m. (2013) carya as marker for tree refuges in southern italy (boiano basin) at the middle pleistocene. palaeogeography palaeoclimatolology palaeoecology, 369, 295-302. orain r., ermolli e. r., lebreton v., di donato v., bahain j. j., sémah a.m. (2015) vegetation sensitivity to local environmental factors and global climate changes during the middle pleistocene in southern italy a case study from the molise apennines. review of palaeobotany and palynology, 220, 69-77. o'regan h.j., turner a., bishop l.c., elton s., lamb a.l. (2011) hominins without fellow travellers? first appearances and inferred dispersals of afroeurasian large mammals in the plio-pleistocene. quaternary science review, 30, 1343-1352. ozenda p. (1975) sur les étages de végétation dans les montagnes du bassin méditerranéen. documents de cartographie écologique, 16, 1-32. ozenda p., 1994. la végétation du continent européen. delachaux and nestlé eds, pp. 280. pagani m., caldeira k., berner r., beerling d.j. (2009) the role of terrestrial plants in limiting atmospheric co2 decline over the past 24 million years. nature, 460 (7251), 85-88. palombo m.r. (2007) large mammal guilds on the italian peninsula from the pliocene to the late pleistocene: new methodological approaches. courier forschungsinstitut senckenberg 259, 1346. palombo m.r. (2014) deconstructing mammal dispersals and faunal dynamics in sw europe during the quaternary. quaternary science reviews, 96, 50-71. petrosino p., jicha b.r., mazzeo f.c., russo ermolli e. (2014a) a high resolution tephrochronological record of mis 14-12 in the southern apennines (acerno basin, italy). journal of volcanology and 115 piacenzian to pleistocene flora and vegetation in italy geothermal research, 274, 34-50. petrosino p., russo ermolli e., donato p., jicha b., robustelli g., sardella r. (2014b) using tephrochronology and palynology to date to the mis 13 lacustrine sediments of the mercure basin (southern apennine-italy). italian journal of geosciences, 133(2), 169-186. pieruccini p., di celma c., di rita f., magri d., carnevale g., farabollini p., ragaini l., caffau, m. (2016) sedimentology, faunal content and pollen record of middle pleistocene palustrine and lagoonal sediments from the peri-adriatic basin, abruzzi, eastern central italy. quaternary research, 86(3), 359-372. pignatti s. (1982) flora d’italia, 1-3. bologna. pignatti s. (1998) i boschi d'italia. sinecologia e biodiversità. utet, torino, italy (xvi + pp. 677). pignatti g. (2011) la vegetazione forestale di fronte ad alcuni scenari di cambiamento climatico in italia. forest 8, 1-12. pini r., ravazzi c., donegana m. (2009a) pollen stratigraphy, vegetation and climate history of the last 215 ka in the azzano decimo core (plain of friuli, north-eastern italy). quaternary sciences review, 28, 1268-1290. pini r., ravazzi c., monegato g. (2009b) la storia vegetazionale e climatica del pleistocene superiore nella successione lacustre continua di fimon (colli berici, vicenza). convegno aiqua. “la variabilità del clima nel quaternario: la ricerca italiana” 18-20, 76-77 (roma). pini r., ravazzi c., reimer p. j. (2010) the vegetation and climate history of the last glacial cycle in a new pollen record from lake fimon (southern alpine foreland, n-italy). quaternary science reviews, 29(23-24), 3115-3137. pini r., bertini a., martinetto e., vassio e. (2014) the pleistocene flora of northern italy. palaeobotany of italy. publication of the museum of nature south tyrol, (9), 290-307. pini r., furlanetto g., vallé f., badino f., wick l., anselmetti f. s., bertuletti p., fusi n., morlock m., delmonte b., harrison s.p., maggi v., ravazzi c. (2022) linking north atlantic and alpine last glacial maximum climates via a high-resolution pollen-based subarctic forest steppe record. quaternary science reviews, 294, 107759. pinti d.l., quidelleur x., chiesa s., ravazzi c., gillot p.y. (2001) k-ar dating of an early middle pleistocene distal tephra in the interglacial varved succession of piànico-sèllere (southern alps, italy). earth planetary science letters, 188, 1-7. pontini m.r. (1997) analisi palinologica e interpretazione paleoclimatica dei depositi continentali del bacino tiberino (umbria, italia). unpublished ph.d thesis, university of perugia, italy, pp. 134. pontini m.r., bertini a. (2000) late pliocene vegetation and climate in central italy: high resolution pollen analysis from the fosso bianco section (tiberino basin). geobios, 33, 519-526. pontini m.r., albianelli a., basilici g., bertini a., napoleone g. (2002) pollen record and magnetostratigraphy of the middle-late pliocene lacustrine sequence in the tiberino basin, (central italy). bollettino della società geologica italiana, 1, 467-472. quézel p., médail f. (2003) ecologie et biogéographie des forêts du bassin méditerranéen, elsevierlavoisier eds, paris, france, pp. 571. raffi i., rio d. (1980) nuove osservazioni sulla distribuzione del nannoplancton calcareo nella serie di le castella (calabria). paleontologia, stratigrafia, evoluzione, 1, 181-186. ravazzi c. (1993) variazioni ambientali e climatiche al margine meridionale delle alpi nel pleistocene inferiore: stratigrafia e analisi pollinica della serie di leffe. (phd thesis). university of milan, italy. ravazzi c. (2003) gli antichi bacini lacustri e i fossili di leffe, ranica e piànico-sèllere. cnr special publications. quaderni di geodinamica alpina e quaternaria, bergamo, italy (pp. 176). ravazzi c., rossignol-strick m. (1994) interglacialglacial cycles on the early pleistocene of the leffe basin (northern italy): preliminary report. historical biology, 9, 11-15. ravazzi c., rossignol-strick m. (1995) vegetation change in a climatic cycle of early pleistocene age in the leffe basin (northern italy). palaeogeography palaeoclimatology palaeoecology, 117, 105122. ravazzi c. moscariello a. (1998) sedimentation, palaeoenvironmental evolution and time duration of earliest pleistocene climatic cycles in the 24-56 m fm core interval (leffe basin, northern italy). in: van kolfschoten, th., gibbard, p. (eds.), proceedings of the inqua-seqs symposium “the dawn of the quaternary”meded. ned. inst. toegep. geowet. tno 60, 467-490. ravazzi c., pini r., breda m., martinetto e., muttoni g., chiesa s., confortini f., egli r. (2005) -the lacustrine deposits of fornaci di ranica (late early pleistocene, italian pre-alps): stratigraphy, palaeoenvironment and geological evolution. quaternary international, 131, 35-58. ravazzi c., pini r., breda m. (2009) reconstructing the palaeoenvironments of the early pleistocene mammal faunas from the pollen preserved on fossil bones. quaternary sciences review, 28, 2940-2954. raymo m.e., ruddiman w.f., backman j., clement b.m., martinson d.g. (1989) late pliocene variation in northern hemisphere ice sheets and north atlantic deep-water circulation. paleoceanography, 4 (4), 413-446. raymo m.e., oppo d.w., flower b.p., hodell d.a., mcmanus j.f., venz k.a., kleiven k.f., mcintyre k. (2004) stability of north atlantic water masses in face of pronounced climate variability during the pleistocene. paleoceanography 19, pa2008. doi: 10.1029/2003pa000921 ricci m., bertini a., capezzuoli e, horvatinčić n, andrews j.e, fauquette s, fedi m. (2015) palynological investigation of a late quaternary calcareous tufa and travertine deposit: the case study of bagnoli in the valdelsa basin (tuscany, central italy). review of palaeobotany and paly 116 bertini a., combourien-nebout n. nology, 218, 184-197. ricciardi e. (1961) analisi pollinologica dei sedimenti lacustri lignitiferi di pietrafitta (perugia, italia). pollen et spores, 3 (2), 325-328. ricciardi e. (1965) analisi polliniche di una serie stratigrafica dei sedimenti lacustri del pleistocene inferiore nel bacino di leonessa (rieti-italia centrale). giornale botanico italiano, 72, 62-82. rio d. (1982) the fossil distribution of coccolithophore genus gephyrocapsa kamptner and related pliopleistocene chronostratigraphic problems. in: prell w.l., gardner j.v., et al. (eds.). initial reports of the deep sea drilling project, 68, 325-343. rio d., thunell r., sprovieri r., bukry d., di stefano e., howell m., raffi i., sancetta c., san filippo a. (1989) stratigraphy and depositional history of the pliocene bianco section, calabria, southern italy. palaeogeography palaeoclimatology palaeoecology, 76, 85-105. rio d., raffi i., villa g. (1990) pliocene-pleistocene distribution patterns in the western mediterranean. in: karstetn k.a., mascle j., et al. (eds.), proceedings of odp, scientific results 107, 513-533. rio d., channell j.e.t., bertoldi r., poli m.s., vergerio p.p., raffi i., sprovieri r., thunell r.c. (1997) pliocene sapropels in the northern adriatic area: chronology and paleoenvironmental significance. palaeogeography palaeoclimatology palaeoecology, 135, 1-25. robustelli g., russo ermolli e., petrosino p., jicha b., sardella r., donato p. (2014) tectonic and climatic control on geomorphological and sedimentary evolution of the mercure basin, southern apennines, italy. geomorphology, 214, 423-435. rossi s. (2003) etude pollinique de la séquence lacustre pléistocène de piànico-sèllere (italie). (phd thesis). université de droit, d'economie et des sciences d'aix marseille iii. rossignol-strick m., planchais n. (1989) climate patterns revealed by pollen and oxygen isotope records of a tyrrhenian sea core. nature, 342, 413416. rossignol-strick m., planchais n., paterne m., duzert d. (1992) vegetation dynamics and climate during the last deglaciation in the south adriatic basin from a marine record. quaternary sciences review, 11, 415-423. roulleau e., pinti d., rouchon v., quidelleur x., gillot p.y. (2009) tephrochronostratigraphy of the lacustrine interglacial record of piànico, italian southern alps: identifying the volcanic sources using radiogenic isotopes and trace elements. quaternary international, 204, 31-43. roveri m., flecker r., krijgsman w., lofi j., lugli s., manzi v.,sierro f.j., bertini a., camerlenghi a., de lange g., govers r., hilgen f.j., hübscher c., meijer p.t., stoica m. (2014) the messinian salinity crisis: past and future of a great challenge for marine sciences. marine geology, 352, 25-58. ruddiman w.f., raymo m.e., martinson d.g., clement b.m., backman j. (1989) pleistocene evolution: northern hemisphere ice sheets and north atlantic ocean. paleoceanography, 4 (4), 353-412. russo ermolli e. (1994) analyse pollinique de la succession lacustre pléistocène du vallo di diano (campanie, italie). annales de la société géologique de belgique, 117, 333-354. russo ermolli e. (1999) vegetation dynamics and climate changes at camerota (campania, italy) at the pliocene-pleistocene boundary. ii quaternario (ital. j. quat. sci.), 12, 207-214. russo ermolli e. (2000) pollen analysis of the acerno palaeolacustrine succession (middle pleistocene, southern italy). geological society of london spec. publ., 181, 151-159. russo ermolli e., cheddadi r. (1997) climatic reconstruction during the middle pleistocene: a pollen record from vallo di diano (southern italy). geobios, 30 (6), 735-744. russo ermolli e., di pasquale g. (2002) vegetation dynamics of southwestern italy in the last 20,000 yr inferred from pollen analysis of a tyrrhenian sea core. vegetation history and archaeobotany, 11 (3), 211-220. russo ermolli e., juvigné e., bernasconi s., brancaccio l., cinque a., lirer, l., ozer a., santangelo n. (1995) le premier stratotype continental de quatre stades isotopiques successifs du pléistocène moyen pour le bassin méditerranéen septentrional: le vallo di diano (campanie, italie). comptes rendus de l'académie des sciences paris, 321, 877-884. russo ermolli e., aucelli p.p.c., di rollo a., mattei m., petrosino p., porreca m., rosskopf c.m. (2010a) an integrated stratigraphical approach to the middle pleistocene succession of the sessano basin (molise, italy). quaternary international, 225, 114127. russo ermolli e., sardella r., di maio g., petronio c., santangelo n. (2010b) pollen and mammals from the late early pleistocene site of saticula (sant'agata de' goti, benevento, italy). quaternary international, 225, 128-137. sabato l., bertini a., masini f., albianelli a., napoleone g., pieri p. (2005) the lower and middle pleistocene geological record of the san lorenzo lacustrine sequence in sant'arcangelo basin. (southern apennines, italy). quaternary international, 131, 59-69. sadori l., giardini m., chiarini e., mattei m., papasodaro f., porreca m. (2010) pollen and macrofossil analyses of pliocene lacustrine sediments (salto river valley, central italy). quaternary international, 225, 44-57. sadori l., bertini a., combourieu-nebout n., kouli k., mariotti lippi m., roberts n., mercuri a.m. (2013) palynology and mediterranean vegetation history. flora mediterranea, 23, 141-156. sánchez goñi m.f., cacho i., turon j.l., guiot j., sierro f.j., peypouquet j.p., grimalt j.o., shackleton n.j. (2002) synchroneity between marine and terrestrial responses to millenial scale climatic variability during the last glacial period in the mediterranean region. climate dynamics, 19, 95-105. 117 piacenzian to pleistocene flora and vegetation in italy sánchez goñi m.f. (2022) pollen: a key tool for understanding climate, vegetation, and human evolution. in: progress in botany. springer, berlin, heidelberg. doi: 10.1007/124_2022_63 sangiorgi l., capotondi l., combourieu-nebout n., vigliotti f., brinkhuis h., giunta s., lotter a.f., morigi c., negri a., reichart g.j. (2003) holocene seasonal sea surface temperature variations in the south adriatic sea inferred from a multiproxy approach. journal of quaternary science, 18, 723-732. santangelo n., di donato v., lebreton v., romano p., russo ermolli e. (2012) palaeolandscapes of southern apennines during the late early and the middle pleistocene. quaternary international, 267, 20-29. sarnthein m., bartoli g., prange m., schmittner a., schneider b., weinelt m., andersen n., garbe-schonberg d. (2009) mid-pliocene shifts in ocean over-turning circulation and the onset of quaternary-style climates. climate of the past, 5, 269-283. scardia g., muttoni g. (2009) paleomagnetic investigations on the pleistocene lacustrine sequence of piànico-sèllere (northern italy). quaternary international, 204(1-2), 44-53. strani f., sardella r., mecozzi b. (2021) an overview of the middle pleistocene in the north mediterranean region. alpine and mediterranean quaternary (amq), 34(1), 5-16. suc j.p., bessais e. (1990) pérennité d'un climat thermo-xérique en sicile avant, pendant, après la crise de salinité messinnienne. comptes rendus de l'académie des sciences paris, 294, 10031008. suc j.p., bertini a., combourieu-nebout n., diniz, f., leroy s., russo ermolli e., zheng z., bessais e., ferrier j. (1995) structure of west mediterranean and climate since 5.3 ma. acta zoologica cracoviensa, 38, 3-16. suc j.p., combourieu-nebout n., seret g., popescu s. m., klotz s., gautier f., clauzon g., westgate j., insinga d., sandhu a.s. (2010) the crotone series: a synthesis and new data. quaternary international, 219(1-2), 121-133. suc j.p., popescu s.m. (2005) pollen records and climatic cycles in the north mediterranean region since 2.7 ma. geological society, london, special publications, 247(1), 147-158. tomaselli r., baldazzi a., filipello s. (1973) carta bioclimatica d'italia. la vegetazione forestale d'italia. ministero agricoltura e foreste, roma, 5-24. toti f. (2018) a mediterranean perspective on the early-middle pleistocene transition with emphasis on marine isotope stage 19. unpublished phd thesis, università degli studi di firenze, pp. 388. toti f., bertini a. (2018) mediterranean pollen stratigraphy across the early-middle pleistocene boundary. alpine and mediterranean quaternary (amq), 31 (1), 199-203. tzedakis p.c. (2005) towards an understanding of the response of southern european vegetation to orbital and suborbital climate variability. quaternary sciences review, 25, 1585-1599. tzedakis p.c. (2007) seven ambiguities in the mediterranean palaeoenvironmental narrative. quaternary sciences review, 26, 2042-2066. tzedakis p.c., channell j.e.t., hodell d.a., kleiven h.f., skinner l.c. (2012) determining the natural length of the current interglacial. nature geoscience, 5, 138-141. urban b., arias c., bigazzi g., bonadonna f. (1983) early pleistocene palynostratigraphy of fornace tini, valle ricca (central italy). palaeogeography palaeoclimatology palaeoecology, 41, 153-164. vaiani s.c., venezia p. (1999) la sezione pleistocenica del lamone (appennino romagnolo): associazioni a foraminiferi ed evoluzione paleoambientale. bollettino della società paleontologica italiana, 38, 39-57. valleri g., bertoldi r., bertini a. (1990) foraminifer and pollen assemblages from the pliocene of ponte an elsa (valdarno inferiore, tuscany). bollettino della società paleontologica italiana, 29, 321-333. van couvering j. a., castradori d., cita m. b., hilgen f. j., rio d. (2000) the base of the zanclean stage and of the pliocene series. episodes journal of international geoscience, 23(3), 179-187. van otterloo r.h., sevink j. (1983) the quaternary evolution of the upper volturno basin. in: isernia la pineta (ed.), calderini, bologna, 35-39. von koenigswald w., kolfschoften t. (1996) the mymomys arvicola boundary and the enamel thickness quotient (sdq) of arvicola as stratigraphic markers in the middle pleistocene. in: turner, c. (ed.), the early middle pleistocene in europe. balkema, rotterdam, 211-226. watts w.a., allen j.r.m., huntley b. (1996) vegetation history and palaeoclimate of the last glacial period at lago grande di monticchio, southern italy. quaternary science review, 15, 113-132. watts w.a., allen j.r.m., huntley b. (2000) palaeoecology of three interstadial events during oxygenisotope stages 3 and 4: a lacustrine record from lago grande di monticchio, southern italy. palaeogeography palaeoclimatology palaeoecology, 155, 83-93. wutke k., wulf s., tomlinson e.l., hardiman m., dulski p., luterbacher j., brauer a. (2015) geochemical properties and environmental impacts of seven campanian tephra layers deposited between 40 and 38 ka bp in the varved lake sediments of lago grande di monticchio, southern italy. quaternary science reviews, 118, 67-83. zagwijn w.h. (1957) vegetation, climate and timecorrelations in the early pleistocene of europe. geologie en mijnbouw 19, 233-244. zagwijn w.h. (1959) zur stratigrafischen und pollenanalytischen gliederung der pliozenen ablagerungen im roertal-graben und venloer graben der niederlande. fortschritte in der geologie von rheinland und westfalen 4, 5-26. zagwijn w.h. (1960) aspects of the pliocene and early pleistocene vegetation in the netherlands. mededelingen van de geologische stichting c iii, 118 bertini a., combourien-nebout n. 1-5. 1-78. zagwijn w.h. (1963) pollen-analytical investigations in the tiglian of the netherlands. mededelingen van de geologische stichting, 16, 49-71. zagwijn w.h. (1975) variations in climate as shown by pollen analysis, especially in the lower pleistocene of europe. in: wright a.e., moseley f. (eds.), ice ages: ancient and modern, 137-152. zagwijn w.h. (1992) the beginning of the ice age in europe and its major subdivisions. quaternary science reviews, 11, 583-591. zagwijn w.h., suc j.p. (1984) palynostratigraphie du plio-pléistocène d’europe et de méditerranée nord-occidentales: correlations chronostratigraphiques, histoire de la végétation et du climat. paléobiologie continentale, 14, 475-483. zagwijn w.h., hager h. (1987) correlations of continental and marine neogene deposits in the southeastern netherlands and the lower rhine district. mededelingen van de werkgroep voor tertiaire en kwartaire geologie, 24 (1-2), 59-78. zonneveld k.a.f. (1996) palaeoclimatic reconstruction of the last deglaciation (18 ka bp-8 ka bp) in the adriatic sea region: a land-sea correlation based on palynological evidence. palaeogeography, palaeoclimatology, palaeoecology, 122(1-4), 89106. ms. received: december 12, 2022 revised: april 15, 2023 accepted: april 20, 2023 avaiable online: may 10, 2023 119 piacenzian to pleistocene flora and vegetation in italy 120 imp.derita evoluzione pleistocenica del margine tirrenico dell’italia centrale tra eustatismo, vulcanismo e tettonica donatella de rita, marina fabbri & corrado cimarelli dp.to scienze geologiche, università degli studi roma3, l.go san leonardo murialdo 1, 00146 roma e-mail derita@uniroma3.it riassunto: de rita d. et al., evoluzione pleistocenica del margine tirrenico dell’italia centrale tra eustatismo, vulcanismo e tettonica. (it issn 0394-3356, 2004). viene presentata una sintesi dei dati ottenuti durante la realizzazione dei fogli geologici alla scala 1:50.000 riguardanti alcune aree costiere del lazio. la possibilità di porre a confronto l’evoluzione di settori che presentano problematiche simili ma con situazioni locali specifiche ha permesso di evidenziare, a partire da circa 850 ka, una storia comune per la costa del lazio settentrionale e centrale, diversa da quella che ha invece interessato nello stesso intervallo di tempo la costa del lazio meridionale. la ricostruzione degli eventi a scala regionale ha permesso di distinguere gli effetti di una tettonica regionale (soprattutto di sollevamento isostatico lungo la costa del lazio settentrionale e centrale e di subsidenza per quello meridionale) rispetto a movimenti locali che potrebbero essere essenzialmente legati alle fasi vulcaniche che hanno contemporaneamente interessato il margine tirrenico del lazio. vengono inoltre evidenziate alcune problematiche che riguardano l’organizzazione cartografica nazionale ed in particolare la denominazione dei sintemi a scala regionale e la necessità di introdurre una nomenclatura in grado di associare nel suo interno più sintemi non distinguibili sul terreno. abstract: de rita d. et al., the evolution of the tyrrhenian margin of central italy: the interplay between volcanism, eustatism and tectonciv events). (it issn 0394-3356, 2004). we present a synthesis of the data collected during the field work devoted to the realization of the geological map at the 1:50.000 of italy, concerning some coastal areas of latium. the possibility to compare the evolution of areas envolved in the same geodinamic contest but having different local structural framework, has allowed us to evidence a common history, starting from 850 ka, for the coast of northern and central latium , different from that of the southern coast. the effect of local estensional tectonic related to the volcanism which interested central italy in that period was distinguished. the units have been organized in unconformity bounded stratigraphic units (ubsu) on the base of the hierarchy order of the basal surfaces delimithing them. synthemes have been limited by surfaces recognized at regional scale caused by oscillation of the sea level. each surface has been dated on the base of the geochronological data and /or the faunistic content of the above sediments and then it has been correlated to an isotopic stage. the vulcanic units have been organized following the indication of fisher and schmincke (1984), by introducing the eruption units. “an eruption unit is a deposit defined as a thickness of volcanic material deposited from an eruptive pulse, an eruptive phase or an eruption…it is a conceptual entity that relates volcanic activity and a rock stratigraphic unit”. this method allows to consider all the unconformities recognizable in volcanic areas which cannot be extended at regional scale but are important to reconstruct the main phases of the volcano evolution. it allows even to consider the volcanic evolution in its regional contest. the volcanic deposits originated by the reworking of the primary units have been distinguished in syn-eruption and inter-eruption units (smith, 1991; de rita et alii, 2002 b; giordano et alii, 2002 a). the geological and structural evolution of the island of ponza, zannone and palmarola in the pontine archipelago, 30 km south east from the central coast of latium, has been reconstructed. these three islands are the remnants of a submarine dome complex developed from the upper pliocene to almost 1.1 ma. three main ryolithic domes have been recognized in ponza, developed along ne-trending lineaments and showing different hyaloclastic facies reflecting the different geological contest in which they developed. the norhernmost piana d’incenso dome shows a prevailing hyaloclastic facies made of clast supported breccias and by flow banded lavas produced by its intrusive mode of emplacement, as a cryptodome. similar facies characterize the zannone dome in the zannone island, where the intrusive nature is demonstrated by the structural relationship between the flow-banded lavas and the sedimentary units: these are tilted and deformed along low angle normal faults at the contact with the vulcanites. we have interpreted that the domes emplaced as cryptodome, because they were intruded almost at the center of a structural high of the sedimentary substratum made of the mesozoiccenozoic brittle rocks. the other domes of ponza and palmarola show different hyaloclastic facies, mainly made of thick hyaloclastites showing different degree of brecciation reflecting the different degree of magma-water interaction. we suggest that the extrusive mode of emplacement of these domes is because their emplacement was along regional extensional faults controlling the structural evolution of the continental platform on which the volcanic dome complex developed. in the southern part of ponza a subaerial trachytic dome developed almost 1.1 ma, after that the rhyolitic volcanism ended. the geological gap between the rhyolitic and the trachytic phases of volcanism, is evidenced by a high relief erosive surface. on the three island, in the range between 80 and 110 m a.s.l., marine terraces are present. these terraces have been correlated on the base of their similar morphology and because the above sediments are lithologically similar. they have to be formed after the end of the volcanism in the three islands. the uplifting of the surface occurred probably during a contemporaneous relative low standing of the sea level. we suggest to relate this event with the uplifting of the central coast of latium, that occurred between 0.9 and 0.8 ma, during the isotopic stage 22, when the alkali-potasssic volcanism started. the difference of the altitude at which the surface presently lies, is probably due to the effect of local extensional tectonic. along the northern and the central coast of latium, we have recognized three orders of terraces which coincide in the altitude and the age. in the northern coast the presence of a small basin infilled by volcaniclastic sediments, was helpful in correlating stratigraphic succession of the vulsini, sabatini and vico volcanic districts to the coastal area successions. here, the ubsu have been organized in 5 synthemes whose basal surfaces were produced during low standing of the sea level. on the base of geochronological data and /or the faunistic content of the above sediments, the last three synthems have been ascribed to the 9,7 and 5 isotopic stages respectively (de rita et alii 2002 b). in the central coast of italy, in the area of roma city, the ubsu have been organized in 7 synthemes (giordano et alii 2003), the last three of which have the same altitude and age of those recognized along the northern coast. along the southern coast no terraces can be recognized. it has been then possible to establish that the coast of central italy was subjected to a regional uplift evaluated in the order of 0,2 mm/y, whereas the southern coast was subjected to a continuous subsidence active from pliocene. local extensional tectonic related to the volcanism has been recognized in the roman area. some problems related to the organization of the national cartography are evidenced. they concern the nomenclature of synthem at regional scale and the opportunity to introduce a specific hierarchy to indicate an association of synthemes. in fact, in some cases it has not been possible to recognize all the discontinuities related to sea level oscillations, precluding the possibility to distinguish single synthemes that have been unified together. they do not represent a supersynthem because unconformities of major hierachic order were not recognized. parole chiave: tettonica, vulcanismo, pleistocene, eustatismo, margine tirrenico, italia centrale. keywords: tectonics, volcanism, pleistocene, eustatism, tyrrhenian margin, central italy. il quaternario italian journal of quaternary sciences 17(2/1), 2004, 523-536 524 d. de rita, m. fabbri & c. cimarelli introduzione nel pleistocene, l’evoluzione del margine tirrenico dell’italia centrale è stata determinata da più fattori: da una parte gli effetti della tettonica estensionale post orogenica che in quest’epoca raggiunge il suo acme con conseguente sviluppo del processo vulcanico relativo alla nascita del bacino tirrenico, dall’altra le oscillazioni glacio-eustatiche del livello del mare. la complessità degli eventi è stata analizzata e discussa in più lavori la cui attenzione è via via focalizzata ora su un tema ora su un altro. manca, tuttavia, a tutt’oggi un quadro d’insieme degli eventi in cui sia stato valutato il ruolo dei vari fattori. questa nota si propone di dare un contributo alla risoluzione del problema, illustrando i risultati ottenuti durante la realizzazione di più fogli geologici alla scala 1:50.000, (progetto carg). il lavoro di cartografia di dettaglio di più aree costiere, comprese tra il lazio settentrionale e quello meridionale (fig. 1), ha infatti offerto la possibilità di porre a confronto l’evoluzione di settori che presentano problematiche simili ma con situazioni locali specifiche. l’obiettivo cartografico ha portato alla messa a punto di nuove tecniche di analisi di terreno in grado di consentire correlazioni significative alla scala regionale. questo, insieme all’approccio interdisciplinare, è stato di grande ausilio, permettendo di inquadrare i processi vulcanici nell’ambito dell’evoluzione regionale e di valutare gli effetti della tettonica distensiva sia a scala regionale sia locale. e’ stato infine possibile effettuare una valutazione quantitativa dei tassi di sollevamento che le regioni costiere del lazio hanno subito negli ultimi 300 ka. in base alla gerarchizzazione delle superfici che le delimitano, le unità sono state organizzate in unità stratigrafiche a limiti inconformi (ubsu; salvador, 1987a, b). i sintemi sono definiti da superfici riconosciute a livello regionale e legate alle oscillazioni del livello del mare. per le unità vulcaniche, tenendo conto delle differenze sia temporali che di estensione dei processi che avvengono in ambito vulcanico rispetto a quelli caratterizzanti l’ambiente sedimentario costiero, si è preferito mantenere una nomenclatura separata e un’organizzazione stratigrafica legata alla storia evolutiva del vulcano, in cui le superfici di discontinuità identificate possono o meno coincidere con quelle riconosciute a livello regionale (de rita et alii, 2000). i depositi originatisi dal rimaneggiamento delle unità vulcaniche sono stati analizzati in termini di unità sin-eruttive ed inter-eruttive (smith,1991; de rita et alii, 2002b; giordano et alii, 2002a ) i sintemi sono stati datati sulla base di dati geocronologici e/o paleontologici e correlati alla scala degli isotopi dell’ossigeno (shackleton et al i i , 1990; shackleton, 1995). nei primi paragrafi viene presentata una sintesi dei dati più significativi ottenuti nelle aree studiate che sono: le isole pontine settentrionali, l’area costiera del lazio settentr ionale al confine con la toscana (montalto di castro-tarquinia), l’area costiera romana (tra la città di roma ed ardea), il settore sud occidentale del vulcano di roccamfina (fig. 1). in un secondo paragrafo saranno evidenziate le correlazioni e la valutazione degli effetti della tettonica regionale rispetto a quella locale. saranno, inoltre, discusse alcune problematiche inerenti la cartografia nazionale in ambito vulcanico. fig. 1 ubicazione dei settori analizzati lungo la costa tirrenica dell’italia centrale. location of the analyzed sectors along the tyrrhenian coast of central italy. area delle pontine settentrionali e’ stata ricostruita l’evoluzione geologico-strutturale delle isole di ponza, zannone e palmarola, facenti 525evoluzione pleistocenica del margine ... parte del foglio borgo grappa (de rita et alii, in stampa). le tre isole, insieme a ventotene e santo stefano fanno parte dell’arcipelago pontino localizzato a circa 30 km dalla costa dell’italia centrale a sud del circeo (fig. 1). fig. 2 (a) dem delle isole pontine settentrionali. 1) domi. 2) faglia presunta (per la spiegazione vedi il testo). (modificato da de rita et alii, 2001). (b) carta geologica schematica delle isole pontine settentrionali. 1) unità sedimentarie meso-cenozoiche. 2) unità sedimentarie plio-quaternarie. 3) lave riolitiche in dicchi. 4) facies ialoclastica clasto sostenuta. 5) facies ialoclastica matrice sostenuta. 6) prodotti trachitici del domo di m. la guardia. 7) ubicazione dei terrazzi marini. (a) dem of the northern pontine islands. 1) domes. 2) inferred fault (for explanation, see text). (modified from de rita et alii, 2001). (b) schematic geological map of the northern pontine islands. 1) mesozoic-cenozoic sedimentary units. 2) pliocene-quaternary sedimentary units. 3) rhyolitic coherent lava dikes. 4) clast-supported hyaloclastic breccia. 5) matrice-supported hyaloclastic breccia. 6) mt. la guardia dome trachytic products. 7) ubications of marine terraces. 526 le isole giacciono sulla piattaforma continentale tirrenica il cui assetto strutturale è molto simile a quello dell’appennino centrale, costituito, cioè, da unità di thrust mio-plioceniche, disarticolate in una serie di alti e bassi strutturali dalla tettonica estensionale post-orogenica relativa all’evoluzione plio-pleistocenica del bacino tirrenico (zitellini et alii, 1984). le tre isole sono costituite dai resti di un complesso di domi riolitici sottomarini che mostrano una grande variazioni di facies ialoclastiche, da finemente brecciate matrice sostenute a clasto sostenute coerenti, fino a lave coerenti in dicco, connesse al diverso grado di frammentazione subito dal magma al contatto con l'acqua (carmassi et alii, 1983; scutter et alii, 1998; de rita et alii, 2001). nel caso dell’isola di ponza il processo eruttivo da sottomarino divenne subaereo, con un corrispondente cambio di chimismo dei magmi da riolitici a trachitici. nel corso del rilevamento, in base alla natura dei componenti dei depositi ed in base alle correlazioni stratigrafiche si è potuto stabilire che tutti i depositi affioranti nella parte meridionale dell’isola di ponza, poggianti sulle facies ialoclastiche e costituiti da unità di surges, di colata piroclastica e domi lavici, provengono da un unico centro localizzato nell’area di monte la guardia (fig. 2). la loro sequenza stratigrafica illustra le varie fasi di crescita del domo trachitico (de rita et alii, in stampa). oltre al domo finale trachitico di monte la guardia, sull’isola di ponza sono stati riconosciuti altri tre domi riolitici principali: uno in corrispondenza di monte pagliaro, due coalescenti tra loro nell’area di cala dell’acqua ed un terzo nella parte più settentrionale di piana d’incenso (fig. 2). nell’isola di palmarola sono stati identificati almeno tre domi riolitici: uno nella parte settentrionale con centro in corrispondenza di monte tramontana e due coalescenti nella parte meridionale con centro a mare lungo la costa occidentale dell’isola (fig. 2). a zannone è stato identificato un unico domo che comprende la totalità degli affioramenti vulcanici dell’isola (fig. 2). particolare attenzione è stata dedicata ai rapporti strutturali tra le unità vulcaniche e sedimentarie. infatti a zannone lungo la costa settentrionale affiorano unità sedimentarie dal paleozoico al mesozoico con rapporti strutturali complessi variamente interpretati dagli autori (segre, 1952, 1953; parotto & praturlon, 1975). il rilevamento ha permesso di stabilire che i contatti strutturali tra le unità sedimentarie sono superfici a basso angolo determinate dallo scollamento lungo piani debolmente inclinati prodotti dalla spinta di crescita del domo di zannone (fig. 3). tale domo deve essersi messo in posto con modalità tipo criptodomo, al contatto tra il flysch e le unità carbonatiche sottostanti. questa ipotesi è anche supportata dalle facies ialoclastiche del domo che presentano un basso grado di autobrecciazione e un alto grado di coerenza. le stesse facies ialoclastiche caratterizzano il domo di piana d’incenso nella parte più settentrionale di ponza. interessante sottolineare che un dragaggio effettuato poco a largo della costa occidentale dell’isola ha incontrato a circa 30 m di profondità rocce calcareo-dolomitiche (martorelli et alii, 2003), confermando così la presenza di un alto strutturale del basamento prevulcanico già evidenziato da un sondaggio (savelli, 1943) e da dati gravimetrici, nel settore settentrionale dell’isola di ponza (carmassi et alii, 1983; bellucci et alii, 1997). l’alto strutturale si estenderebbe fino all’isola di zannonne dove le rocce calcareo-dolomitiche costituiscono la falesia settentrionale dell’isola. questo dato permette di stabilire che i domi di zannone e piana d’incenso si sono messi in posto come criptofig.3 schema dei rapporti stratigrafici e strutturali dell’isola di zannone. 1) arenarie e filliti permo-triassiche. 2) dolomie triassiche. 3) calcari, marne e arenarie cretacico-mioceniche. 4) argille messiniane. 5) lave riolitiche in dicchi. 6) facies ialoclastica clasto sostenuta. le frecce indicano i piani di scivolamento gravitativo prodotti dalla messa in posto del domo. stritigraphic and structural scheme of zannone island (not to scale). 1) permian-triassic sandstones and phyllites. 2) triassic dolomites. 3) cretaceous-miocene limestones, marls and sandstones. 4) messinian clays. 5) rhyolitic lava dikes. 6) clast-supported hyaloclastic breccia. arrows indicate low angle slide planes due to dome emplacement. d. de rita, m. fabbri & c. cimarelli 527 domi a differenza degli altri domi costituenti le isole di ponza e palmarola che per le caratteristiche delle facies ialoclastiche possono essere considerati domi estrusivi. la modalità di messa in posto come criptodomi o domi esogeni può essere determinata dal contesto strutturale in cui i magmi risalgono in superficie ed in particolare dalla presenza o meno di faglie regionali (cimarelli et alii, 2003). l’età di messa in posto dei domi sottomarini è posteriore al pliocene superiore. infatti, a palmarola sono presenti depositi argillosi, attribuiti al pliocene superiore per la presenza di globorotalia inflata (carrara et alii, 1986), in accordo con le datazioni radiometriche effettuate sulle lave del dicco di monte tramontana, che lo datano a circa 1.6 ma (barberi et alii, 1967). il domo trachitico di monte la guardia ha un’età di circa 1.1 ma (barberi et alii 1967; savelli 1983, 1987; bellucci et alii, 1999). durante l’intervallo di tempo intercorso tra la messa in posto delle vulcaniti sottomarine e le successive unità esplosive del domo trachitico di monte la guardia deve essersi verificato un concomitante fenomeno di sollevamento dell'isola e ritiro del livello del mare. questi eventi hanno prodotto le profonde incisioni vallive visibili nel settore meridionale dell’isola di ponza, successivamente colmate dai prodotti esplosivi e dai depositi del loro rimaneggiamento. tali incisioni erano state precedentemente interpretate come residui di centri idromagmatici (carmassi et alii, 1983; de rita et alii, 1986; vezzoli, 1988; bellucci et alii, 1997, 1999). su tutte e tre le isole tra le quote 80 e 120 m s.l.m., sono presenti depositi terrazzati già riconosciuti e riferiti a momenti diversi di stazionamento del livello del mare (segre, 1952, 1953; barberi et alii, 1967; vezzoli, 1988; carrara et alii 1993, 1994; bellucci et alii, 1997, 1999). questi terrazzi sono invece stati correlati tra loro per evidenze morfologiche e per la similitudine litologica dei depositi e riferiti ad un intervallo di tempo successivo all’attività vulcanica delle tre isole. un affioramento estremamente significativo è quello presente sulla falesia sudorientale di monte la guardia, nel settore meridionale di ponza (fig. 4). in questa località è ben visibile l'appoggio della superficie di terrazzamento su due delle unità piroclastiche trachitiche (unità 2 e 3 della fig. 4) che accompagnano la messa in posto del domo. l’unità piroclastica 3 è all’interno di un canale esposto nella sua integrità. inoltre i dati di terreno indicano che, durante l'attività iniziale del domo di monte la guardia, il livello del mare stazionava più o meno alla quota di affioramento dei depositi relativi che sono di natura idromagmatica, o sono flussi detritici ad alta concentrazione arrivati in acqua. il sollevamento della superficie deve essersi verificato per un processo di uplift continentale concomitante al ritiro del mare. collocare temporalmente questi fig. 4 appoggio del terrazzo marino (5) sulle unità piroclastiche trachitiche (1,2,3,4) del domo di m. la guardia. marine terrace deposit (5) laying on the mt. la guardia trachytic pyroclastic units (1,2, 3,4) evoluzione pleistocenica del margine ... 528 eventi risulta pressoché impossibile. dopo 1.1 ma, lungo la costa tirrenica una superficie di erosione che testimonia un evento di sollevamento regionale concomitante ad un momento di basso stazionamento del livello del mare è posta in correlazione con lo stadio isotopico 22, tra 0.9 e 0.8 ma e potrebbe essere relativa alla risalita dei magmi responsabili del vulcanismo alcalino-potassico del lazio. in tal caso, la superficie potrebbe coincidere con la base delle unità di san marcello e di ponte galeria, rispettivamente lungo la costa settentrionale e centrale del lazio. le differenze in quota della superficie riscontrata sulle tre isole possono essere spiegate da processi tettonici di sollevamento e basculamento che diversi autori hanno già segnalato (carrara et alii, 1993, 1994) e che possono aver svincolato le tre isole tra loro o anche singoli settori delle stesse. ad esempio è possibile ipotizzare un importante svincolo strutturale che limiti da una parte le isole di zannone, palmarola ed il settore settentrionale di ponza rispetto al settore meridionale che risulterebbe maggiormente ribassato. tale lineamento strutturale avrebbe una direzione circa nesw ed insisterebbe sull’area di forte alterazione idrotermale nel settore settentrionale di ponza (area di cava in località cala dell'acqua) e di gavi (fig. 2).un discorso a parte merita la superficie sub pianeggiante e debolmente inclinata verso mare, presente a piano d’incenso nel settore settentrionale di ponza e precedentemente interpretata come superficie di abrasione marina (carrara et alii , 1994). la definizione dei processi vulcanici ha consentito di porre l’accento sulla necessità di distinguere la geometria delle superfici che vengono prese in considerazione in relazione al loro sviluppo in ambito vulcanico. ad esempio, nel caso di corpi intrusivi subsuperficiali di tipo criptodomo, superfici piane debolmente inclinate vengono prodotte dallo stesso processo di risalita del corpo intrusivo e non indicano necessariamente la presenza di un terrazzo marino, a meno del ritrovamento in situ dei sedimenti relativi. gli unici depositi presenti al di sopra della superficie di piano d’incenso sono delle argille che derivano dal processo di alterazione della lava sottostante (de rita et alii, 2003). inoltre, il sollevamento locale dovuto alla risalita a giorno del corpo intrusivo può essere responsabile della formazione di una serie di terrazzi basculati che non necessariamente indicano ordini di terrazzi successivi relazionabili alle oscillazioni del livello del mare. area costiera del lazio settentrionale tra tarquinia e montalto di castro questo settore costiero del lazio settentrionale (fig. 1) ha offerto l’opportunità di analizzare i rapporti tra vulcanismo e sedimentazione costiera, tenendo conto delle variazioni del livello del mare occorse durante il quaternario. a questo scopo è stata determinante l’analisi dei depositi vulcanoclastici di un piccolo bacino sedimentario, bacino di tuscania, collocato tra l’area costiera e la periferia dei distretti vulcanici dei vulsini, di vico e dei sabatini a oriente, che si configura per un lungo periodo come parte dell’apron (sensu smith, 1991) dei vulcani stessi (de rita et alii, 2002). le correlazioni hanno tenuto conto del fatto che il settore costiero del lazio settentrionale è un’area di relativa stabilità tettonica (de rita et alii, 2002). la presenza di depositi terrazzati di origine marina è stata oggetto di approfonditi studi (bonadonna, 1967; alberti et alii, 1970; fazzini et alii, 1972; ambrosetti et alii, 1978, 1981; conato & dai pra, 1980; radtke et alii, 1982; radtke, 1983; bartolini & bosi, 1983; bartolini et alii, 1984; hearty & dai pra, 1986a, b; hearty, 1986; bosi et alii, 1990; messina et alii, 1990; palieri et alii, 1990). i sedimenti più antichi del pleistocene inferiore p.p. sono stati inclusi in un unico supersintema (supersintema monte riccio) in quanto la superficie inferiore è molto articolata lasciando ipotizzare una frammentazione di ambienti imputabile ad una fase tettonica. all’interno del supersintema le unità litostratigrafiche non sono state organizzate in sintemi per l’impossibilità di correlare superfici relative alle oscillazioni del livello del mare tra affioramenti piccoli e discontinui. i depositi costieri e vulcanoclastici relativi al pleistocene inferiore p.p.-pleistocene superiore sono stati organizzati all’interno di 5 sintemi correlati agli stadi isotopici attraverso datazioni geocronologiche e/o associazioni faunistiche (fig. 6). le caratteristiche di facies dei depositi costieri più antichi, organizzati in almeno tre terrazzi marini sviluppati parallelamente alla costa attuale e compresi nel sintema di s. marcello, testimoniano il processo di emersione dell’area avvenuto circa 850 ka fa le prime unità vulcaniche alcalino-potassiche che raggiungono l’area sono comprese nel successivo sintema biedano tra gli stages isotopici 15 e 11. si tratta di unità ignimbritiche provenienti dal centro del paleobolsena (nappi, 1985), datate intorno ai 491±9 ka (villa in funiciello et alii, in stampa), a cui si associa una unità ignimbritica sabatina (rosa, 1995) datata a 433 ± 6 ka (cioni, 1993). nell’area relativa al bacino di tuscania al si sopra delle ignimbriti basali è presente una successione complessa costituita da depositi relativi a flussi iperconcentrati e a debris flow (smith, 1991), a cui si intercalano nella parte alta depositi fluviali e più raramente palustri e lacustri. sono inoltre presenti livelli di ricaduta provenienti dal vulcano di vico, fra cui vico α (cioni et alii, 1987) datato a 419 ±1.5 ka (laurenzi & villa, 1987), e colate di lava vicane. non sono stati rinvenuti in affioramento depositi marini costieri relativi a questo sintema. la mancanza di tali depositi fa ipotizzare che in quel momento la costa fosse più arretrata rispetto all’attuale. l’ipotesi potrebbe essere supportata dalla segnalazione di depositi correlabili, attualmente sommersi (chiocci in de rita et alii, 2002 b) la sedimentazione nel bacino di tuscania continua fino allo stadio isotopico 9, con la deposizione di sedimenti in facies prevalentemente fluviale, lacustre e palustre, in cui si intercalano livelli di ricaduta pliniana e stromboliana e colate di lave di provenienza vicana e vulsina; gli ultimi 12 metri sono fortemente cementati da cemento travertinoso. quindi, l’apporto vulcaniclastico all’interno del bacino diminuisce notevolmente. infatti la geometria e la distribuzione dei depositi relativi allo stadio isotopico 7, che affiorano in terrazzi discontinui lungo i corsi d’acqua principali, indicano che il bacino di tuscania è totalmente riempito. i depositi costieri d. de rita, m. fabbri & c. cimarelli relativi al sintema archi di pontecchio (stadio isotopico 7) hanno al tetto un deposito vulcanico relativo all’attività del centro di latera datato tra i 190 ed i 166 ka (nicoletti et alii, 1981; metzeltin & vezzoli, 1983; barberi et alii, 1984) indicando che la chiusura del bacino permette ormai collegamenti diretti tra le aree vulcaniche e la costa. il tetto del terrazzo relativo si trova in affioramento tra le quote 30 e 45 m s.l.m. il successivo terrazzo affiorante alle quote 10-15 m s.l.m contiene strombus bubbonius ed è riferito quindi al tirreniano (palieri & sposato, 1988). i depositi costieri relativi sono correlati con quelli continentali tramite la presenza del deposito del tufo rosso a scorie nere vicano, datato a 155 ± 0.01 ka (sollevanti, 1983). nel loro insieme queste unità costituiscono il sintema casalone (fig. 6). le correlazioni stratigrafiche e le date geocronologiche hanno permesso, inoltre, di risolvere un’interessante questione che si è rivelata di grande importanza anche per la ricostruzione dell’evoluzione costiera dell’area romana. la questione concerne l’attribuzione cronologica di dama dama tiberina di stefano & petronio che era correlata in passato allo stadio isotopico 7. denti appartenenti a questo cervide sono stati ritrovati all’interno del bacino di tuscania, in una sequenza continua di depositi con al tetto del travertino, la cui età radiometrica è risultata pari a 256 ka +41/31. questo ha portato all’attribuzione di dama dama tiberina allo stadio isotopico 9. 529 fig. 6 schema dei rapporti morfo-litostratigrafici dell’area del lazio settentrionale. 1) unità pre-pleistocene medio; 2) unità del pleistocene medio-superiore; 3) principali superfici erosive. (modificato da de rita et alii, 2002) morpholithostratigraphic scheme of the northern latium area. 1) pre-middle pleistocene units; 2) middle-upper pleistocene units; 3) main erosional surfaces. (modified from de rita et alii, 2002) fig. 5 schema dei terrazzi marini recenti nel lazio settentrionale. 1) superficie del terrazzo marino relativo allo stadio isotopico 5; 2) superficie del terrazzo marino relativo allo stadio isotopico 7; 3) superficie del terrazzo marino relativo alla stadio isotopico 9; 4) limiti di massima trasgressione marina realtivi ai tre terrazzi. (modificato da de rita et alii, 2002). schematic map showing recent marine terraces in northern latium. 1) isotopic stadi 5 marine terrace surface. 2) isotopic stadi 7 marine terrace surface. 3) isotopic stadi 9 marine terrace surface. 4) maximum marine transgression boundary. (modified from de rita et alii, 2002). evoluzione pleistocenica del margine ... area costiera romana l’area analizzata ricade ai limiti occidentali dei fogli geologici alla scala 1:50.000 albano e roma del progetto carg (fig. 1). come per il settore settentrionale, anche nell’area romana l’emersione inizia intorno a 850 ka (giordano et alii, 2003) mentre l’attività vulcanica, relativa ai distretti dei colli albani e dei sabatini, inizia intorno a 560 ka (karner & renne, 1998; giordano et alii, 2003). i sedimenti antecedenti, relativi al pleistocene inferiore sono stati organizzati all’interno di un supersintema, il supersintema monte mario, in quanto limitati da una superficie indotta da una fase tettonica (giordano et alii, 2002b). nell’area romana erano già stati riconosciuti diversi ordini di terrazzi marini (ambrosetti & bonadonna, 1967; bonadonna, 1967; conato & dai pra, 1980; conato et alii, 1980; carbone, 1980) correlati a stadi isotopici dal 15 al 5 (malatesta & zarlenga, 1985, 1986, 1988; milli, 1992, 1997; marra, 1993; marra & rosa, 1995; marra et alii, 1995; karner et alii, 2001a, b; bergamini et alii, 2000; giordano et alii, 2003). nell’area romana è presente un elemento di grande importanza nell’evoluzione del settore che è il corso del tevere. l’antico corso, paleotevere, occupava sicuramente una posizione diversa dall’attuale ed aveva la sua foce nell’area di ponte galeria (marra & rosa, 1995; milli, 1997). i depositi prevulcanici dell’area romana appartengono in gran parte all’attività di questo antico fiume. lo sviluppo del delta si colloca in un intervallo di tempo compreso tra gli stadi isotopici 22 e 16 in una vasta area compresa tra la dorsale di monte mario e la costa, interessata da sedimenti costieri che superano gli 80 m di spessore. la deviazione del corso del paleotevere in un percorso a se avviene tra 700 e 600 ka ed è causata dal sollevamento della dorsale di monte mario (fig. 7) (giordano et alii, 2002b, 2003). e’ probabile che l’ambiente fluvio-palustre relativo alla valle del paeotevere, in corrispondenza dell’area di sviluppo del vulcano tuscolano-artemisio, abbia fornito l’acqua necessaria ad innescare le eruzioni freatopliniane dei così detti “tufi pisolitici” (de rita et alii, 2002a). i depositi delle quattro eruzioni separati da paleosuoli che nel loro insieme comprendono i “tufi pisolitici” auctorum, si trovano in parte nel sintema di santa cecilia (stadio isotopico 15) e in quello di valle giulia (stadio isotopico 13) a testimonianza che un evento importante come l’oscillazione del livello del mare non abbia avuto alcuna ripercussione sullo stile eruttivo del vulcano in un momento di acme della sua attività. questa constatazione rafforza l’opportunità di mantenere nomenclature diverse per le suddivisioni a scala regionale e quelle inerenti all’attività vulcanica, per poter porre facilmente in relazione eventi vulcanici, vulcano-tettonici ed eventi a scala regionale di più ampio significato. gli ingenti volumi di materiale emessi nel corso delle eruzioni dei “tufi pisolitici” costringerà il tevere a modificare ulteriormente il suo percorso verso quello attuale. il sintema valle giulia, relativo allo stadio isotopico 13, oltre alle unità vulcaniche e ai depositi fluviali, contiene ingenti volumi di travertino a testimonianza di una tettonica attiva e di un importante sistema idrotermale (giordano et alii, 2003). nel successivo sintema torrino, relativo allo stadio isotopico 11 si ha la messa in posto dei massimi volumi dei prodotti vulcanici. poco dopo la messa in posto del tufo lionato e del tufo di villa senni datato a circa 350 ka (bernardi et alii, 1982; radicati di brozolo et alii, 1981; karner & renne, 1998) avviene il sollevamento dell’alto di castelporziano-pomezia lungo faglie ad andamento ne, probabile riattivazione di elementi strutturali attivi nel pliocene-pleistocene inferiore ai margini del bacino di ardea (facenna et alii, 1994). le unità del tufo lionato-villa senni nell’area costiera di anzio ed ardea poggiano su sabbie di spiaggia e su sedimenti marini a testimonianza del fatto che quello era il livello del mare al momento della loro deposizione. l’unità del villa senni è stata datata a circa 350 ka (bernardi et alii, 1982); in quest’epoca wealbroeck et alii (2002) hanno calcolato che il livello del mare era a -120 m r.l.m. il top dell’unità di villa senni è interessato da una superficie di abrasione, coperta da sabbie di spiaggia, duna e retroduna (“duna rossa antica” auctorum), relative allo stadio isotopico 9. nell’area di pomezia, castelporziano, questi sedimenti risultano sollevati fino ad una quota di 100 m s.l.m. probabilmente in conseguenza del sollevamento dell’alto avvenuto secondo direttrici strutturali ad orientamento ne (giordano et alii, 2003). i sedimenti del successivo sintema quartaccio si appoggiano alla struttura sollevata: si tratta di due unità, aurelia e vitinia, separate da una superficie di disconformità a basso rilievo (fig. 7). la quota di affioramento dell’unità aurelia è circa 30 m, mentre il tetto dell’unità vitinia è a circa 55-60 m s.l.m. il top dell’unità vitinia è datato a circa 285 ±1 (karner et alii, 2001b) per la presenza al tetto dei sedimenti di pomici riferite al tufo giallo di sacrofano proveniente dal vulcano di sacrofano nel distretto dei sabatini (de rita et alii, 1983). per queste relazioni il sintema quartaccio è correlato con lo stadio isotopico 9 e le due unità aurelia e vitinia sono considerati due suoi subsintemi. questa correlazione permette anche di confermare l’attribuzione del dama dama tiberina a questo stadio isotopico in accordo a quanto osservato lungo la costa settentrionale del lazio. a quote topografiche più basse, circa 3040 m, è stato riconosciuto un altro terrazzo i cui sedimenti costituiscono il sintema campo selva correlato allo stadio isotopico 7 e ancora più in basso, a circa 1530 m s.l.m un ultimo terrazzo i cui sedimenti costituiscono il sintema saccopastore correlato allo stadio isotopico 5. area costiera meridionale al confine con la campania (roccamonfina) per quanto riguarda l’area meridionale del lazio al confine con la campania (fig. 1) è possibile individuare un settore in continua subsidenza fin dalle fasi iniziali dell’evoluzione del vulcano di roccamonfina. infatti, in quest’area, pur avendo individuato sulla base delle analisi di facies e dei caratteri litologici dei sedimenti, le fasi sin e inter-eruttive di ogni eruzione del vulcano in un arco di tempo compreso tra i 600 ed i 250 ka, non è stato possibile stabilire alcuna relazione con la situazione costiera in mancanza di depositi correlabil i (giordano et alii, 2002a; de rita et alii, 2003a). tuttavia, 530 d. de rita, m. fabbri & c. cimarelli sulla base delle date geocronologiche disponibili sono stati identificati 4 sintemi, correlati rispettivamente agli stadi isotopici 11, 9, 7 e 5 (fig. 8) (de rita et alii, 2003a). si riscontra una correlazione sorprendente di questi sintemi con quelli riconosciuti nei settori più a nord, almeno per l’intervallo di tempo relativo agli ultimi 400 ka. al di sotto, l’organizzazione delle unità in ubsu è molto più complessa: la successione delle unità eruttive relative alla crescita del vulcano di roccamonfina è stata organizzata all’interno di un unico sintema (sintema m. ofelio) che in realtà comprende più superfici relative alle oscillazioni del livello del mare, che non possono però essere correlate verso costa per la mancanza di affioramenti. tuttavia è possibile stabilirne l’inizio in coincidenza delle prime manifestazioni vulcaniche dell’area datate circa a 600 ka (ballini et alii, 1989). le unità vulcaniche poggiano su sedimenti sabbioso-argillosi quaternari e su conglomerati riferiti al pliocene superiore (conglomerati di minturno; giordano et alii, 1995), attualmente molto al di sotto del livello del mare, a testimonianza che, lungo questo tratto della costa meridionale del lazio, il vulcanismo è contemporaneo ad un processo di subsidenza. discussione dei dati e note conclusive il confronto dell’evoluzione dei settori analizzati permette alcune considerazioni di interesse generale e alcune conclusioni interessanti ai fini della ricostruzione 531 fig.7 schema delle principali caratteristiche strutturali, vulcaniche e geomorfologiche dell’area costiera romana. 1) terrazzo marino relativo allo stadio isotopico 5; 2) terrazzo marino relativo allo stadio isotopico 7; 3) terrazzo marino relativo allo stadio isotopico 9; 4) alto strutturale di pomezia-castel porziano; 5) corso del paleo-tevere;6) delta del paleo-tevere; 7) faglie principali; 8) caldere; 9) crateri. (modificato da giordano et alii, 2003) scheme of the main structural, volcanic, geomorphologic features of the roman coastal area. 1) isotopic stadi 5 marine terrace; 2) isotopic stadi 7 marine terrace; 3) isotopic stadi 9 marine terrace; 4) pomezia-castel porziano structural high; 5) paleo-tiber course; 6) paleo-tiber delta; 7) main faults; 8) caldera rim; 9) crater rim. (modified from giordano et alii, 2003) evoluzione pleistocenica del margine ... dell’evoluzione del margine costiero del lazio. l’attività vulcanica alcalino potassica è preceduta da un generale sollevamento costiero che porta all’emersione dell’area a circa 850 ka, contemporaneamente sia nel lazio settentrionale che in quello centrale. questo sollevamento ha interessato anche la piattaforma costiera ed è riconoscibile nei terrazzamenti presenti sulle isole pontine. mentre sul margine continentale non sono evidenti elementi strutturali significativi che hanno accompagnato tale sollevamento, nelle isole è ipotizzabile una tettonica estensionale che potrebbe risalire a questo intervallo di tempo. nel caso delle isole pontine, il lavoro di riconoscimento e correlazione delle superfici di discontinuità e dei terrazzi, ha posto una serie di problemi che vale la pena di riassumere: in caso di presenza di corpi intrusivi subsuperficiali di tipo criptodomi, superfici piane debolmente inclinate vengono prodotte dallo stesso processo di risalita del corpo intrusivo e non indicano necessariamente la presenza di un terrazzo marino, a meno del ritrovamento in situ dei sedimenti relativi. superfici piane, ad esempio si sono sviluppate durante la crescita del domo di syowa sinzan in giappone o del domo di lassen peak in california (williams & mc birney, 1979). la veloce crescita di questi domi, da pochi mesi a poche centinaia di anni, è in grado inoltre di giustificare, nel caso di domi cresciuti lungo la costa, la presenza di uno o più terrazzi basculati che non necessariamente indicano ordini di terrazzi successivi relazionabili alle oscillazioni del livello del mare (vedi il caso dell’isola di panarea). e’ quindi necessaria un’attenta valutazione della genesi delle varie superfici ed un loro confronto con quelle identificabili lungo la costa continentale. un altro dato interessante, ottenuto tramite la correlazione delle superfici di base dei sintemi con i momenti di basso stazionamento del livello del mare (fig. 8) è la presenza, lungo la costa del lazio, di tre ordini di terrazzi correlati agli stadi isotopici 9, 7 e 5, confrontabili tra loro per numero, età e quote. i tassi di sollevamento calcolati per l’area costiera del lazio settentrionale e per quella romana (fig. 9) sono dell’ordine di 0,2 mm annui, confrontabili tra loro ed in accordo con i tassi di sollevamento regionale calcolati per il tirreniano (bordoni & valensise, 1998, anzidei et alii, 2002). questo dato permette a sua volta di valutare gli effetti della tettonica regionale rispetto a quella locale. ad esempio localmente nell’area di castel porziano i l tasso di sollevamento del sintema quartaccio, calcolato di circa 2,0 ± 0,2 mm/anno (giordano et alii, 2003), risulta di entità maggiore e consente di valutare tale entità come connessa all’azione di una tettonica locale. considerato poi l’intervallo di tempo relativo è possibile relazionare il sollevamento al climax dell’attività vulcanica, ricorso appunto in questo periodo (cavinato et alii, 1992, 1994). il riconoscimento di terrazzi analoghi sulla costa settentrionale e centrale del lazio pone un quesito interessante ai fini dell’organizzazione cartografica nazionale: i sintemi relativi infatti possono essere considerati a tutti gli effetti gli stessi (fig. 8) e come tali dovrebbero essere nominati allo stesso modo. questo significa che le nomenclature locali, prese dai toponimi maggiormente significativi per i fogli rilevati, non dovrebbero più essere valide e bisognerebbe trovare un nome significativo alla scala regionale, almeno del lazio. questo problema diviene ancora più evidente quando la correlazione dei sintemi si estende anche a settori come quello di roccamonfina (fig. 8) dove non sono presenti sedimenti costieri. il metodo di rilevamento ha però consentito di individuare nell’area vulcanica sintemi regionali che tramite le date geocronologiche si correlano perfettamente a quelli già individuati più nord. quindi anche in questo caso i sintemi dovrebbero avere una nomenclatura unificata. sarebbe interessante a questo punto avere dei confronti nell’area sabatina, non ancora oggetto di rilevamento alla scala 1:50.000, che potrebbe essere risolutiva per questo problema e dove tra l’altro sono presenti fattori locali di grande interesse come la messa in posto dei domi intrusivi di tolfa, dei ceriti e dei cimini che per età costituirebbero l’anello mancante tra l’area delle pontine e quella della costa sia in termini di estensione regionale che temporale. un altro problema riguarda la risoluzione di alcuni sintemi che sia nel lazio settentrionale che in quello centrale sono in realtà la somma di più sintemi (s. marcello a nord, ponte galeria al centro e m. ofelio a sud). questi sintemi in realtà contengono sicuramente più superfici relative a diversi momenti di basso ed alto stazionamento del livello del mare (milli, 1997; marra et alii, 1998) che non sono state introdotte per più motivi. a nord per la mancanza di sufficienti affioramenti, nel centro e a sud perché elementi come il delta del tevere e la crescita di un vulcano rendono difficile con la loro rapida sedimentazione l’attibuzione certa delle superfici riconosciute alle oscillazioni del livello del mare. quindi a rigore di logica in realtà i sedimenti relativi non costituiscono un unico sintema ma un’associazione di sintemi, che non può essere definita supersintema perché per questa definizione è necessaria una gerarchia delle superfici limiti maggiore. si vuole pertanto suggerire di introdurre un’ulteriore nomenclatura ad esempio associazione di sintemi, per apportare ulteriore suddivisioni nel futuro, qualora il dettaglio stratigrafico lo consentisse. un ultimo dato importante che vale la pena di sottolineare riguarda proprio la mancanza dei sedimenti nell’area costiera di roccamonfina. tale assenza permette di evidenziare il processo di subsidenza, per altro già noto, di questo settore (ippolito et alii, 1973; naso & tallini, 1993; catenacci & molinari, 1965; giordano et alii, 1995). si ringraziano vivamenti tutti i collaboratori al progetto carg, fogli geologici montalto di castro, tarquinia, roma , albano, borgo grappa e del progetto pilota roccamonfina. nota in una riunone avvenuta in sede apat nel gennaio 2005 è stata proposta una nomenclatura unificata dei supersintemi e dei sintemi riconosciuti come gli stessi lungo la costa del lazio. pertanto attualmente il supersintema aquatraversa ha sostituito i supersintemi monte riccio e monte mario; il supersintema aurelio-pontino ha sostituito i supersintemi marta, zannone e galeria; il sintema ponte galeria si chiama magliana; il sintema flaminia sostituisce il sintema santa cecilia; il sintema villa glori il valle giulia; il sintema barca di parma i l quartaccio; i l sintema fiume fiora archi di pontecchio e campo selva; ed infine il sintema fiume marta il casalone, zannone sud e saccopastore. il supersintema ponza ed il sintema pontino sono stati soppressi non avendo superfici di base identificate. 532 d. de rita, m. fabbri & c. cimarelli 533 fig. 9 confronto dei tassi di sollevamento calcolati per l’area costiera del lazio settentrionale e per l’area costiera romana. comparison of the uplift rates computed for the northern latium coastal area and for the roman coastal area. fig. 8 correlazione delle unità a limiti inconformi rapportata alla scala degli stadi isotopici (shackleton et alii, 1990; shackleton, 1995). lo schema evidenzia come l’organizzazione delle unità in ubsu, rapportata alle variazioni del livello del mare, permetta correlazioni significative a livello regionale, ponendo il problema della nomenclatura dei sintemi e supersintemi a questa scala. correlations between unconformity buonded stratigraphic units compared to the isotopic stadi scale (shackleton et alii, 1990; shackleton, 1995). the scheme evidences the ubsu methodology capability to allow stratigraphic correlations at regional scale. evoluzione pleistocenica del margine ... riferimenti bibliografici alberti a., bertini m., bono g.l., nappi g., salvati l. (1970) note illustrative della carta geologica d'italia alla scala 1:100.000. foglio 136 tuscania, foglio 142 civitavecchia servizio geologico d’italia. ambrosetti p., bonadonna f.p. (1967) revisione dei dati sul plio-pleistocene di roma atti acc.gioe. di sc. nat. catania, 18, pp. 33-70. ambrosetti p., bartolini c., bosi c. (1981) l’evoluzione geologica e morfologica quaternaria dell’area adiacente la bassa valle del fiume fiora (viterbo). geog. fis. dinam. quat. 4, pp. 104-134. ambrosetti p., carboni m.g., conti m.a., costantini a., esu d., gandin a., girotti o., lazzarotto a., mazzanti r., nicosia u., parisi g., sandrelli f. (1978) evoluzione paleogeografica e tettonica nei bacini tosco-umbro-lazial i nel pliocene e nel pleistocene inferiore – mem. soc. geol. it. 19, pp. 573-580. anzidei m., esposito a., benini a. (2002) using roman age submerged structures as leveling benchmarks: interaction between recent sea level variations and crustal deformation 2002 egs general assembly, nice, abstract volume. ballini a. barberi f., laurenzi m. a. mezzetti f.,villa i.m. (1989) nuovi dati sulla stratigrafia del vulcano di roccamonfina. boll. grup. naz. vulc. 2 pp. 533-555. barberi f., borsi s., ferrara g., innocenti f. (1967) contributo alla conoscenza vulcanologica e magmatologica delle isole dell’arcipelago pontino mem. soc. geol. it. 6, pp. 581-606. barberi f., innocenti f., landi p., rossi u., saitta m. santacroce r., villa i.m. (1984) the evolution of the latera caldera (central italy) in the light of subsurface data. bull. volc. 47, pp. 125-141. bartolini c., bosi c. (1983) the tyrrhenian transgression in the tarquinia area (northern latium, italy). geog. fis. din. quat. 6, pp. 131-136. bartolini c., belluomini g., bosi c. (1984) isoleucine epimerazation as a tool for dating northern latium raised beaches boll. soc. geol. it. 103, pp. 485490. bellucci f., grimaldi m., lirer l., rapolla a. (1997) stucture and geological evolution of the island of ponza, italy; inferences from geological and gravimetric data j. volcanol. geotherm. res. 79, pp. 87-96. bellucci f., lirer m., munno r. (1999) geology of ponza, ventotene and santo stefano islands (with 1:15.000 scale geological map). acta vulcanol. 11 (2), pp. 197-222. bergamin l., carboni m.g., di bella l.,marra f., palagi i. (2000) stratigraphical and paleoenvironmental evidences of the pleistocene sediments of m.mario (rome) ecl. geol. helv. 93, pp. 265275. bernardi a., de rita d., funiciello r., innocenti f., villa i.m. (1982) chronology and structural evolution of alban hills volcanic complex, latium, italy workshop on explosive volcanism, s.martino al cimino. bonadonna f.p. (1967) studi sul pleistocene del lazio. iii. linee di costa lungo il litorale di tarquinia (lazio settentrionale). geologica romana 6, pp. 121-135. bordoni p., valensise g. (1998) deformation of the 125 ka marine terrace in italy: tectonic implications in stewart i.s. e vita finzi c. (eds.) coastal tectonics, geol. soc. of london, sp.pub. 146, pp. 71-110. bosi c., palieri l., sposato a. (1990) guida all’escursione sui terrazzi e linee di costa del litorale del lazio settentrionale ottobre aiqua, cnr. carboni m.g. (1980) contributi alla stratigrafia del sottosuolo della campagna romana: il sondaggio malagrottta boll. soc. geol. it., 99, pp. 167-174. carmassi m., de rita d., di filippo m., funiciello r. (1983) geology and volcanic evolution of the island of ponza, italy geol. rom. 22, pp. 211232. carrara c., conato v., dai pra g. (1986) segnalazione di sedimenti pliocenici nell’isola di palmarola (isole pontine, italia centrale) mem. soc. geol. it. 35, pp.127-131. carrara c., conato v., dai pra g. (1993) marine and continetal plio-quaternary deposits of the pontine islands in: quaternary stratigraphy in volcanic areas, field excursion guide book, pp. 53-61. carrara c., cremaschi m., dai pra g. (1994) oscillazioni del livello marino, depositi e morfogenesi continenetali nelle isole pontine (italia centrale). geogr. fis. dinam. quat. 17, pp. 139-153. catenacci e., molinari v. (1966) sull’età dei conglomerati di minturno (lazio meridionale) boll.serv. geol.it. 86, pp. 27-43. cavinato g.p., de rita d., milli s., zarlenga f. (1992) correlazione tra i principali eventi tettonici, sedimentari, vulcanici ed eustatici che hanno interessato l’entroterra (conche intrappenniniche) ed il margine costiero laziale durante il pliocene superiore ed il pleistocene studi geol. camerti, v. spec. 1992/1, pp. 109-114. cavinato g.p., cosentino d., de rita d., funiciello r., parotto m. (1994) tectonic-sedimentary evolution of intrappenninic basins and correlation with the volcano-tectonic activity in central italy mem. desc. carta geol. d’italia 49, pp. 63-76. cimarelli c, de rita d., fabbri m. (2003) facies association of submarine dome complexes: examples from italy iugg 2003 congress sapporo, japan. abstract volume. cioni r. (1993) il complesso di bolsena e il vulcanismo alcalino-potassico del lazio settentrionale. tesi di dottorato v ciclo università di pisa. cioni r., sbrana a., bertagnini a., buonasorte g., landi p., rossii u., salvati l. (1987) tephrostratigraphic correlation in the vulsini, vico e sbatini volcanic successions per min. 56, pp. 137-155. conato v., dai pra g. (1980) livelli marini pleistocenici e neotettonica fra civitavecchia e tarquinia (italia centrale). geol. rom. 19, pp. 181-194. conato v., esu d., malatesta a., zarlenga f. (1980) new data on the pleistocene of rome. quaternaria 22, pp.131-176. de rita d., funiciello r., rossi u., sposato a. (1983) structure and evolution of the sacrofano-baccano caldera (sabatini volcanic complex, rome) jour. volc. geoth. res. 17, pp. 219-236. de rita d., funiciello r., pantosti d., salvini f., sposato a., velonà m. (1986) geological and structural characteristics of the pontine islands (italy) and implication with the evolution of tyrrhenian margin mem. soc.geol. it. 36, pp. 55-65. 534 d. de rita, m. fabbri & c. cimarelli de rita d., fabbri m., giordano g., rodani s., trigari a. (2000) l’utilizzo delle unità stratigrafiche a limiti inconformi in ambiente vulcanico e vulcanoclastico:proposta di una metodologia di terreno e di organizzazione informatica dei dati. boll. soc. geol. it. 119, pp. 749-760. de rita d., giordano g., cecili a. (2001) a model for submarine rhyolite dome growth: ponza island (central italy) – jour. volc. geoth. res., 107, pp. 221-239. de rita d., giordano g., esposito a., fabbri m., paccara p., mazzini i., marsili p., trigari a. (2002 a) large volume, middle pleistocene, phreatomagmatic ignimbrites from the colli albani volcano: stratigraphy, eruptive history and structural control jour. volc. geoth. res. 118, pp. 77-98. de rita d., fabbri m., mazzini i., paccara p., sposato a., trigari a. (2002 b) volcaniclastic sedimentation in coastal environments:the interplay between volcanism and quaternary sea level changes (central italy) quater. inter. 95-96, pp. 141-154. de rita d., giordano g., fabbri m.,rodani s. carta geologica del settore sudoccidentale del vulcano di roccamonfina atlante prototipale per il rilevamento dei nuovi fogli geologici alla scala 1:50.000 coord per le aree vulcaniche: pasquarè g., (in stampa). de rita d., cimarelli c., conte a.m., dolfi d., fabbri m., lombardi l. note illustrative della carta geologica d’italia alla scala 1:50.000. foglio 413 borgo grappa (parte a terra) servizio geologico d’italia (in stampa). faccenna c., funiciello r., bruni a., mattei m., sagnotti l. (1994) evolution of a transfer-related basin:the ardea basin (latium, central italy) basin res. 6, pp. 35-46. fazzini p., gelmini r., mantovani m.p., pellegrini m. (1972) geologia dei monti della tolfa (lazio settentrionale; province di viterbo e roma) mem. soc. geol. it. 11, pp. 65–144. funiciello r., de rita d., sposato a. (coord) note illustrative della carta geologica d’italia alla scala 1:50.000, foglio 353 montalto di castro. in stampa giordano g., naso g., trigari a. (1995) evoluzione tettonica di un settore particolare del margine tirrenico: l’area al confine tra lazio e campania. prime considerazioni studi geol. camerti, v.spec. 1995/2. giordano g., de rita d., fabbri m., rodani s.(2002 a) facies associations of rain-generated versus crater lake-withdraal lahar deposits from quaternary volcanoes, central italy. jour. volc. geth. res. 118, pp. 145-159. giordano g., esposito a., de rita d., fabbri m., mazzini i., paccara p., funiciello r. (2002 b) evoluzione geologica del margine tirrenico laziale tra il pleistoce inferiore e medio. riassunti del convegno fist, torino. giordano g., esposito a., de rita d., fabbri m., mazzini i., trigari a., rosa c., funiciello r. (2003) the sedimentation along the roman coast between middle and upper pleistocene: the interplay of eustatism, tectonics and volcanism, new data and review. il quaternario 16 (bis), pp. 121129. hearthy p.j (1986) an inventory of last interglacial (sensu latu) age deposits from the mediterranean basin: a study of isoleucine epimerazation and useries dating z. geomrph. n.f. 62, pp. 51-69. hearty p.j., dai pra g. (1986a) aminostratigraphy of quaternary marine deposits in the lazio region of central italy z. geomorph. n. f. suppl. 62, pp. 131-140. hearty p.j., dai pra g. (1986b) paleogeographic reconstruction of quaternary shoreline environments in toscana and north lazio, central italy enea rt/pass/86/27. karner d., renne p.r. (1998) 39ar/40ar geochronology of roman volcanic province tephra in the tiber river valley:age calibration of middle pleistocene sea-level changes geol. soc. am. bull. 110, pp. 740-747. karner d., marra f., renne r. (2001 a) the history of the monti sabatini and alban hills volcanoes: groundwork for assessing volcanic-tectonic hazards for rome jour. volc. geoth. res. 107 (1-3), pp. 185-215. karner d., marra f., florindo f., boschi e. (2001 b) pulsed uplift estimated from terrace elevation in the coast of rome: evidence for a new phase of volcanic activity? earth. plan. science lett. 188, (1-2), pp. 135-148. ippolito f., ortolani f., russo m. (1973) struttura marginale tirrenica dell’appennino campano: reinterpretazioni dei dati di antiche ricerche di idrocarburi mem. soc. geol. it. 12, pp. 227-250. laurenzi m. a., villa i. m. (1987) 40ar/39ar chronostratigraphy of vico ignimbrites per. min. 56, pp. 285-293. malatesta a., zarlenga f. (1985) il quaternario di pomezia (roma) e la sua fauna marina boll. soc. geol. it. 104, pp. 503-514. malatesta a., zarlenga f. (1986) evoluzione paleogeografico-strutturale pliopleistocenica del basso bacino romano a nord a a sud del tevere mem. soc. geol. it. 35, pp. 75-85. malatesta a., zarlenga f. (1988) evidence of middle pleistocene marine trasgressions along the mediterranean coast palaeogeo. palaeoclim. palaeoecol. 68, pp. 311-315. marra f. (1993) stratigrafia e assetto geologico-strutturale dell’area romana tra il tevere ed il rio galeria geol. rom. 29, pp. 515-535. marra f., carboni m.g., di bella l., faccenna c., funiciello r, rosa c. (1995) il substrato pliopleistocenico nell’area romana boll. soc. geol. it. 114, pp. 195-214. marra f., rosa c. (1995) stratigrafia ed asssetto geologico-strutturale dell’area romana compresa frea il tevere ed il rio galertia geol. rom. 29, 515535. marra f., florindo f., karner d.b, daniel b. (1998) paleomagnetism and geochronology of early middle pleistocene depositional sequences near rome: comparison with the deep-sea d18 o record – earth. plan. sci. lett. 159, pp. 147-164. martorelli e., chiocci f.l., conte a.m., bellino m., bosman a. (2003) affioramenti vulcanici sottomarini dell’arcipelago pontino occidentale: caratteri petrologici e morfoacustici riassunti del convegno fist geoitalia 2003, bellaria 16-18 settembre. messina p., palieri l. & sposato a. (1990) la diversione del f. fiora (lazio settentrionale) in relazione agli eventi eustatici del pleistocene medio-superiore il quaternario 3 (2), pp. 119-130. metzeltin s., vezzoli l. (1983) contributi alla geologia 535evoluzione pleistocenica del margine ... del vulcano di latera (monti vulsini,toscana meridionale-lazio settentrionale) mem. soc. geol. it. 25, pp. 247-271. milli s. (1992) analisi di facies e ciclostratigrafia in depositi di piana costiera e marino marginali. un esempio nel pleistocene del bacino romano phd thesis, pp. 215 università di roma la sapienza. milli s. (1997) depositional setting and high frequency sequence stratigraphy of the middle-upper pleistocene and holocene deposits of the roman basin geol. rom. 33, pp. 99-136. nappi g.(1985) stratigrafia e petrografia dei vulsini sud-occidentali (caldera di latera) boll. soc. geol. it. 88, pp. 171-181. naso g., tallini m. (1993) tettonica compressiva e distensiva nei monti aurunci occidentali (appennino centrale): prime considerazioni geol. rom. 29, pp. 455-462. nicoletti m., petrucciani c., piro m., triglia r. (1981) nuove datazioni vulsine per uno schema di evoluzione dell’attività vulcanica: nota ii: il quadrante sud-occidentale per. min. 50, pp. 141-169. palieri l., sposato a. (1988) segnalazione di fauna a strombus bubonius nell’area compresa tra tarquinia e montalto di castro il quaternario 1 (2), pp. 161-166 palieri l., raffi i., sposato a., (1990) dati preliminari sul pliocene nella fascia costiera del lazio settentrionale. rend. soc. geol. it., 13:111-114 parotto m., praturlon a. (1975) geological summary of central apennines quaderni de “la ricerca scientifica”, 90. radicati di brozolo f., huneke j.c., papanastasiou d.a., wassemburg g.j. (1981) 40ar/39ar and rb/sr age determinations on qiuaternary volcanic rocks. earth pla. sci. lett. 53, pp. 445-456. radtke u. (1983) genese und altersstellung der marinen terrassen zwischen civitavecchia und monte argentario (mittel ital ien) unter besonderer berucksichitigung der elektronenspin-resonanz altersbestimmungsmethode dusseld: geog. schr., 22, 25-33. radtke u., hennig j., linke w., mungerdorf j. (1981) 230th/234uand esrdating problems of fossils shells in the pleistocene marine terraces (northern latium, central italy) quaternaria, 23., pp. 37-50 radtke u., hennig g. j., mangini a. (1982) untersuchungen zur chronostratigraphie mariner terrassen in mittelitalien 230th / 234u und esrdatierungen an fossilen mollusken eiszeitalter u. gegenwart 32, pp. 49-55. rosa c. (1995) evoluzione geologica quaternaria delle aree vulcaniche laziali: confronto tra il settore dei monti sabatini e quello dei colli albani tesi di dottorato vii°ciclo univerisità di roma “la sapienza”. salvador a. (1987a). uncorformity bounded stratigraphic units geol. soc. am. bull. 98, 232-237. salvador a. (1987b) stratigraphic classification and nomenclature of igneous and metamorphic rock bodies issc. geological society of american bullettin 99, pp. 440-442. savelli c. (1983) età k/ar delle principali manifestazioni riolitiche dell’isola di ponza rend. soc. geol. it. 6, pp. 39-42. savelli c. (1987) k/ar ages and chemical data of volcanism in western pontine islands (tyrrhenian sea) boll. soc. geol. it. 106, pp. 537-546. savelli f. (1943) la bentonite, le argille colloidali e le loro applicazioni scientifiche ed industriali. 21, pp. 202-213. hoepli. milano. scutter c.r., cas r.a.f., moore l. (1998) facies architecture and origin of submarine rhyolitic lava flow-dome complex, ponza, italy jour. geophis. res. 103 (b11), pp. 27551-27566. segre a.g. (1952) formazioni quaternarie marine ed oliche delle isole di palmarola e ponza (mar tirreno, prov. latina) contr. sci. geol. – suppl. a “la ricerca scientifica”; anno 22, pp. 129-137. segre a.g (1953) biogeografia dell’isola di zannone. morfologia e geologia – rend. acc. naz. lincei, 4, serie 4 shackleton n.j., berger a., peltier w.r. (1990) alternative astronomical calibration of the lower pleistocene time scale based on odp site 677 r. soc. edim. trans. (earth sc.) 81, pp. 251-261. shackleton n.j. (1995) new data on the evolution of pliocene climatic variability in: paleoclimate and evolution, with emphasis on human origins. ed. by e.s. vrba, g.h. denton, t.c. partdrige, l.h. burkle, pp. 242-248. yale university/ new haven and london. smith g.a. (1991) facies sequences and geometries in continental volcaniclastic sediments in “sedimentation in volcanic settings” edited by fisher r.v. and smith g.a., society for sedimentary geology special publication 45, pp. 109-121. sollevanti f. (1983) geologic, volcanologic and tectonic setting of the vico-cimino area, italy jour. volc. geoth. res. 17, pp. 203-217. vezzoli l. (1988) attività esplosiva alcalino-potassica pleistocenica dell’isola di ponza boll. gnv, 4 , pp. 584-599. waelbroeck c., labeyrie l., michel e., duplessy j.c., mcmanus j.f., lambeck k., balbon e., labracherie m. (2002) sea level and deep water temperature changes derived from benthic foraminifera isotopic records quat. sc. rev. 21, pp. 295-305. williams h., mc birney a.r. (1979) volcanology freeman cooper & co., san francisco. zitellini n., marani m., borsetti a.m. (1984) post-orogenic tectonic evolution of palmarola and ventotene basins (pontine archipelago) mem. soc. geol. it.; 27, pp. 121-131 536 ms. ricevuto l’11 maggio 2004 testo definitivo ricevuto il 22 giugno 2004 ms. received: may 11, 2004 final text received: june 22, 2004. d. de rita, m. fabbri & c. cimarelli imp.baio& assetto geologico della successione quaternaria nel sottosuolo tra melegnano e piacenza baio mariangelo1, bersezio riccardo2 & bini alfredo2 1aquater, san giuliano milanese (mi) 2dipartimento di scienze della terra, università di milano riassunto: baio m. et al., assetto geologico della successione quaternaria nel sottosuolo tra melegnano e piacenza. (it isnn 03943356, 2004). la presente nota breve ha lo scopo di presentare e descrivere i tratti salienti di una sezione geologica bidimensionale ricostruita nella pianura lodigiana, tra melegnano ed il fiume po, per una lunghezza di oltre 45 km. l’occasione per questo lavoro è stata fornita dalla perforazione di un transetto continuo di sondaggi, pali di fondazione, pozzi ed altre opere di scavo, eseguito per la realizzazione della linea ferroviaria ad alta velocità milano – bologna. scopo del lavoro è principalmente la presentazione di una nuova ed inedita base di dati litologici e geocronometrici, interpretati in via preliminare dal punto di vista stratigrafico. la sezione ricostruita illustra la diversa organizzazione stratigrafica di tre settori. il settore della pianura lodigiana, settentrionale, è caratterizzato dalla presenza di sei unità stratigrafiche di origine fluvioglaciale e fluviale di provenienza sudalpina, di età compresa tra il pleistocene medio (?) e l’olocene; queste si appoggiano lateralmente verso sud sui sedimenti fini di ambiente marino e transizionale della formazione di san colombano (pliocene p.p. – pleistocene inferiore); quest’ultima è coinvolta nel sollevamento tettonico dell’omonima anticlinale di rampa appenninica. il settore del colle di san colombano, immediatamente a sud del precedente, è caratterizzato dalla risalita fino alle vicinanze del piano campagna della formazione già citata, che risulta troncata a tetto da profonde incisioni vallive e ricoperta dalle unità fluvioglaciali e fluviali del pleistocene medio/superiore – olocene, tanto verso nord quanto verso sud. nel settore del po, meridionale, i corpi fluviali olocenici (fino a storici) del po, ricoprono due unità fluvioglaciali e fluviali, di età compresa tra il pleistocene medio (?) ed il pleistocene superiore, alimentate verosimilmente in buona parte dal lato appenninico. l’inferiore di questi corpi ricopre i sedimenti marini del colle di san colombano, riempiendo profonde incisioni vallive sepolte. abstract: baio m. et al., geology of the quaternary succession in the subsurface between melegnano and piacenza. (it isnn 0394-3356, 2004). the current work illustrates a stratigraphic cross-section which crosses the southern plain of lodi, as far south as the po river, 45 km long. the work aims to present the newly available database consisting of the stratigraphic and petrographic data obtained by several tens of boreholes, foundation piles and wells that were drilled for building the high speed railway milano – bologna; these data are complemented by some new geochronometrical 14c ages obtained on samples of organic matter and wood fragments. a preliminary 2d stratigraphic interpretation of this database is provided, in the form of a working hypothesis. the geological cross-section illustrates subsurface stratigraphy, down to a maximum depth of 100 m below sea level. three sectors have been separated on the basis of the geometrical and stratigraphic features, from north to south. in the lodi plain sector (north) six stratigraphic units have been introduced, spanning the middle pleistocene (?) to holocene. the post glacial fluviatile unit, confined within the lambro valley, is entrenched into the glaciofluvial sediments which presumably correlate with the lgm alloformations of the alpine area. these latter unconformably overlay two glacio-fluvial units which have been correlated with different alloformations of the besnate allogroup (late – middle pleistocene), based on 14c age determinations, facies and gravel petrography. the lowermost two units are interpreted as fluviatile and glaciofluvial deposits which might be related to glaciations predating the age of the besnate allogroup. the glaciofluvial units terminate southwards, in the central san colombano hill sector, onto the lowermost stratigraphic unit, whose marine and transitional depositional environments suggest a correlation with the outcropping san colombano fm. (pliocene p.p. – early pleistocene). in the subsurface of this sector, the unit reaches shallow depths (20 m below topography) due to tectonic uplift of the san colombano apenninic ramp anticline. in this same sector it is deeply dissected by an erosion surface which mimics the shape of entrenched valleys. it is covered by the uppermost pleistocene sediments which correlate with the most recent alloformations of the besnate allogroup and with the lgm sediments. in the southern po sector, the holocene po alluvial deposits are cut into glaciofluvial gravel and sands of late pleistocene age, whose petrography suggests a mixing of dominant apenninic gravel with subordinate alpine-derived clasts. the middle – upper pleistocene sediments of the po sector, progressively cover northwards the ancient marine and transitional fine-grained sediments of the san colombano hill sector, which are progressively lowered southwards to depths higher than 100 m below sea level and are no longer reached by boreholes and wells. parole chiave: geologia di sottosuolo, pianura padana, quaternario. keywords: po plain, quaternary, subsurface geology. il quaternario italian journal of quaternary sciences 17(2/1), 2004, 355-359 introduzione i numerosissimi sondaggi geognostici a carotaggio continuo eseguiti lungo il tratto lombardo del tracciato ferroviario alta velocità, spinti nel sottosuolo fino alla profondità media di 40÷50 m e tra i 60 e i 120 m nella zona del po, hanno permesso l'elaborazione di una sezione geologica ininterrotta da melegnano a piacenza (fig. 1). la base dei dati è costituita da nuovi rilievi geologici, in larga parte ancora in corso, dalle stratigrafie sopraccitate alle quali vanno aggiunte le numerosissime stratigrafie ottenute durante l’esecuzione dei pali di fondazione, integrate da numerose altre provenienti da varie banche dati, da campioni di carotaggi solo in parte studiati, da nuove datazioni col metodo del 14c e da recentissime informazioni di tipo archeologico. questa breve nota ha lo scopo di presentare una 356 m. baio, r. bersezio & a. bini versione preliminare della sezione geologica citata, relativa alla fascia dei primi 100÷150 m di sottosuolo. la stessa, lunga circa 45 km, continua poi, attraversando trasversalmente la pianura padana, in un’altra sezione geologica (valloni, baio, bedulli 2003) fino quasi a bologna, per una lunghezza complessiva di entrambe le sezioni di circa 185 km. il lavoro è basato sulla correlazione stratigrafica, eseguita lungo un transetto bidimensionale, delle principali superfici di discontinuità che separano unità stratigrafiche individuate anche sulla base dei caratteri tessiturali e composizionali; queste sono frequentemente caratterizzate dallo sviluppo di sequenze cicliche, spesso di tipo fining upward. sono state riconosciute nove unità informali che rappresentano un primo approccio per gli studi tridimensionali della pianura attualmente in corso. inquadramento geologico la zona di pianura attraversata dalla sezione è localizzata a sud dell'anfiteatro morenico del lario. i sedimenti pleistocenici interessati da questo studio si sviluppano a tetto della successione marina del pliocene pleistocene pro parte e rappresentano i depositi fluvioglaciali e fluviali distali rispetto alle unità glaciali riconosciute a nord (bini, 1997a; b; strini, 2001). questo settore di pianura presenta un’ampia superficie con pendenza quasi uniforme verso se, con gradienti inferiori all'1,5 ‰; in questa superficie sono incisi gli alvei dei fiumi principali, approfonditi entro scarpate di terrazzo decametriche. la stessa superficie è percorsa da paleoalvei con tracce meandriformi delimitati da scarpate metriche e talora occupati da corsi d'acqua sottodimensionati (castiglioni & pellegrini, 2001). poco a nord del po la superficie è interrotta dal rilievo del colle di san colombano (fig. 1) derivante dal sollevamento tettonico pleistocenico di un'anticlinale di rampa connessa con i fronti dei sovrascorrimenti appenninici settentrionali (fantoni et al, 2001; 2003). in affioramento sul colle sono presenti sedimenti marini del pleistocene inferiore (desio, 1952; formazione di san colombano, anfossi et al, 1967). la superficie sommitale della pianura non si raccorda con il livello di base del po essendo troncata dalla scarpata decametrica del terrazzo di somaglia (fig. 2), il quale presenta in questo settore il suo massimo dislivello. l'altezza della scarpata decresce sia verso est sia verso ovest sino ad annullarsi, suggerendo una relazione con il sollevamento dei rilievi appenninici esterni. la sezione melegnano piacenza nella sezione sono riconoscibili tre settori, differenziati su basi stratigrafiche: settore della pianura lodigiana, a nord, settore del colle di san colombano (area di pianura a est del rilievo stesso) e settore del po, a valle della scarpata di somaglia (fig. 2). nel seguito la stratigrafia del sottosuolo relativa a questi settori viene descritta a partire da sud (settore del po) e dall'alto stratigrafico verso il basso. unità a: sabbiosa ghiaiosa limosa. essa affiora nel settore del po e nell'alveo del lambro (settore della pianura lodigiana) (fig. 2). nel settore del po, a valle della scarpata di somaglia, essa comprende i sedimenti deposti dal fiume po in alvei incassati, colmati da tappi di sedimenti fini in seguito all’abbandono dei meandri. a questi si associano sedimenti prevalentemente sabbiosi deposti da corsi d’acqua minori (brembiolino, guardalobbia, mortizza) che incidono o tagliano i meandri fossili del po o vi si sovrappongono. l'età olocenica è testimoniata dalla posizione geometrica e stratigrafica, da una data 14c (2.052 ÷ 2.080, 2.134 ÷ 2.296 cal bc; stuiver e reimer, 1993) eseguita su legni presenti a –12,5 m dal p.c. e dal rinvenimento a -5/-7 m dal p.c. di frammenti fluitati di laterizi di età romana associati a sedimenti grossolani. nella valle del lambro l'unità a è organizzata in tre ordini di terrazzi formati da sedimenti sabbioso ghiaiosi, organizzati in barre di meandro e riempimenti di canali di rotta; a questi si associano sedimenti limoso argillosi di tracimazione. l'età storica dei depositi costituenti il terrazzo intermedio è documentata dai laterizi embricati nelle forme di fondo ghiaiose. unità b: sabbiosa limosa. essa costituisce l'unità superficiale nel settore della pianura lodigiana e nel settore del colle di san colombano sino alla scarpata di somaglia che la interrompe. si tratta di depositi prevalentemente sabbiosi, di colore da bruno a giallo oliva, organizzati in sequenze metriche localmente coronate da facies fini limose argillose talora ricche in materia organica. in questa unità sono inclusi anche i corpi lenticolari sabbiosi ghiaiosi corrispondenti al riempimento della paleovalle del sillaro (fig. 2). lo spessore massimo è dell'ordine dei dieci metri. la composizione petrografica delle ghiaie è caratterizzata dalla prevalenza dei litici sedimentari sui litici magmatici e metamorfici di fig. 1 ubicazione della sezione presentata in fig. 2. index map and location of the geological cross-section of fig. 2. 357assetto geologico della successione ... fi g. 2 – s ez io ne g eo lo gi ca in te rp re ta tiv a ne lla b as sa p ia nu ra l o d ig ia n a t ra m e le g n a n o e p ia c e n za . i so n d a g g i u ti liz za ti s o n o i n d ic at i co n lin ee n er e ve rt ic al i. i p a lli n i n e ri i n d ic a n o l’u b ic az io n e d ei c am p io ni p er d at az io ni 14 c , i tr ia ng ol i ne ri in d ic an o i liv el li ric ch i d i m at er ia o rg a n ic a e fr u s to li ve ge ta li, i q ua d ra ti ne ri in d ic an o i r itr o va m en ti d i m ac ro fo ss ili . le e tà ra d io m et ric he n on c al ib ra te s o n o r ip o rt a te fu o ri s e zi o n e ( si c o n fr o n ti n o n el t es to c o n al cu n i va lo ri c al ib ra ti ). l’ es ag er az io ne v er tic ale è c irc a 50 :1 . in te rp re ta ti ve g eo lo g ic a l c ro ss -s e c ti o n th ro u g h t h e s o u th e rn lo d i p la in ( m el eg an an o – p ia ce nz a) . b or oh ol es ar e lo ca te d b y ve rt ic al lin es ; b la ck d ot s in d ic ate l o ca ti o n o f 1 4 c a g e d e te rm in a ti o n s; th e b la ck t ri an g le s in d ic ate s or ga ni c m at te r an d w o o d y fr a g m e n ts ; b la ck s q ua re s in d ic at es fi n d in g s o f m ac ro fo ssi ls . n o n c a li b ra te d ra d io m e tr ic a g e s a re re p o rt e d a b o ve th e to p o g ra p h y (c o m p ar e w ith t ex t fo r so m e ca lib ra te d v al ue s) . v er tic al ex ag g er at io n i s ab o u t 50 :1 . 358 provenienza alpina. alla base dell'unità un campione di frustoli vegetali ha fornito un'età 14c di 19.909 ÷ 20.785 cal bc (fig.2). unità c: ghiaiosa. essa è presente unicamente nel settore del po, delimitata a tetto e a letto da superfici erosionali talora profondamente incise. essa è costituita da grossi e potenti corpi sedimentari deposti dal po. osservazioni preliminari sulla composizione petrografica delle ghiaie indicano una netta prevalenza di clasti di provenienza appenninica (valle trebbia?) con una modesta presenza di piccoli clasti di provenienza alpina (porfidi, ortogneiss, rocce metamorfiche). alla base dell’unità c è stata ottenuta un'età 14c di 24.833 ± 200 a bp (fig.2). unità d: sabbiosa ghiaiosa. essa è presente nel settore della pianura lodigiana e nel settore del colle di san colombano sino alla scarpata di somaglia che la interrompe (fig. 2). si tratta di sequenze cicliche positive di ghiaie passanti a sabbie di colore grigio, coronate da sedimenti limoso argillosi. questi caratteri sono definiti principalmente nel settore della pianura lodigiana anche in base ad alcune osservazioni effettuate in scavi eseguiti lateralmente rispetto alla traccia della sezione. la continuità verso se di questa unità è attualmente ipotizzata sulla base dei caratteri tessiturali di questo pacco di sedimenti che risulta inquadrato stratigraficamente tra le sabbie brune dell'unità b (a tetto) e le ghiaie prevalenti dell'unità f (a letto). la composizione petrografica delle ghiaie mostra inoltre una marcata differenza rispetto alle ghiaie dell'unità b in quanto è caratterizzata dalla prevalenza dei litici magmatici e metamorfici su quelli sedimentari. due date 14c ottenute da campioni raccolti a tetto e a letto dell'unità nei pressi del fiume lambro (fig. 2) hanno fornito età di 22.035 ± 300 a bp e 23.145 ± 340 a bp. unità e: limosa argillosa e ghiaiosa sabbiosa. essa è presente unicamente a partire dal settore del colle di san colombano. nel settore del po l'unità e comprende una successione prevalentemente limosa argillosa che ricopre potenti corpi sabbiosi ghiaiosi. la successione fine superiore è costituita da un orizzonte esteso trasversalmente alla valle del po per circa 8 9 km, avente spessore variabile da 3 m a 10 m. le litologie prevalenti sono limi, limi sabbiosi e argille localmente ricche di sostanza organica, frustoli vegetali e legni. seguono verso il basso alternanze sottilmente stratificate di limi sabbiosi e sabbie fini. i corpi grossolani sottostanti presentano spessori maggiori di ottanta metri e risultano costituiti da sedimenti sabbiosi ghiaiosi deposti da un paleo po. la composizione petrografica delle ghiaie suggerisce la prevalente provenienza dei clasti dai rilievi appenninici (val trebbia?) con una modesta presenza di piccoli clasti di provenienza alpina (ortogneiss, porfidi e rocce metamorfiche). l'unità termina in corrispondenza del settore del colle di san colombano in appoggio su una superficie erosionale incisa nei sedimenti fini della sottostante unità l. queste geometrie vengono evidenziate da una ricostruzione bidimensionale rispetto alla quale si possono avere variazioni laterali molto significative; per esempio l'emersione del colle di san colombano pochi chilometri a ovest della sezione implica geometrie sostanzialmente diverse. datazioni 14c su legni hanno fornito età maggiori di 42.590 a bp a circa 20 m dal p.c.(fig.2). frequentemente si passa verso il basso in modo graduale a sabbie medio – fini e sabbie grossolane debolmente ghiaiose; localmente si ha un passaggio brusco a ghiaie grossolane con ciottoli e sabbia; non di rado tale passaggio è evidenziato dalla presenza di legni anche di grosse dimensioni (un frammento di legno ha fornito un’età 14c maggiore di 43.580 a bp). unità f: ghiaiosa sabbiosa. nella sezione l’unità f è stata definita a nord del settore del colle di san colombano; le sue relazioni con l’unità e si realizzano lateralmente allo stesso, fuori dalla traccia della sezione. si tratta di due successioni ghiaiose sabbiose sovrapposte, potenti complessivamente fino a 40 m. l’inferiore costituisce una sequenza positiva, con passaggio da corpi ghiaiosi ad unità sabbiose fino a pochi e sottili livelli limosi raramente ricchi in materia organica. la superiore è costituita da un potente pacco di ghiaie, da medie a grossolane, che si sfrangia verso sud in un gruppo di sequenze minori, ghiaiose sabbiose, con livelli limosi argillosi sottili e poco frequenti. la composizione petrografia delle ghiaie è caratterizzata dalla prevalenza dei litici metamorfici e magmatici sui litici sedimentari, di provenienza sudalpina. la terminazione dell’unità f, in appoggio sui sedimenti fini dell’unità l è interpretata in corrispondenza del settore del colle di san colombano. unità g e unità h: sabbiose limose argillose. queste due unità rappresentano i sedimenti più profondi raggiunti dalla sezione di fig.2. come l’unità f, esse sono state riconosciute a nord del settore del colle di san colombano, ove viene interpretato il loro appoggio verticale e laterale sui sedimenti fini dell’unità l. anche in questo caso le relazioni stratigrafiche e geometriche con la parte inferiore dell’unità e non sono interpretabili attraverso questo transetto, realizzandosi lateralmente rispetto alla struttura del colle di san colombano. l’unità g è costituita da sequenze cicliche positive, sabbiose limose argillose, localmente coronate a tetto da un livello limoso argilloso metrico, la cui continuità laterale è interrotta dalla superficie di erosione a letto dell’unità f. anche l’unità h comprende sequenze sabbiose limose argillose, positive, che si caratterizzano per la continuità laterale e lo spessore sempre almeno metrico degli intervalli fini, talora ricchi di materia organica. essa è separata dalla soprastante unità g per mezzo di un livello sommitale limoso argilloso di spessore plurimetrico, continuo pressoché lungo tutta la sezione di fig. 2. l’assenza di ghiaie medie impedisce di confrontare la composizione petrografica di questi sedimenti con quella delle unità soprastanti. la base dell’unità h non è raggiunta lungo il transetto analizzato, se non in corrispondenza della risalita dei sedimenti fini che costituiscono l’unità l, ove viene interpretato l’appoggio su una superficie erosionale molto marcata ed irregolare (fig. 2). unità l: argillosa limosa. essa è stata individuata nel settore del po a profondità superiori a 80 m dal p.c.(fig. 2, roggia brembiolina), mentre a sud di somaglia, in un sondaggio agip, è presente fra –120 m e – 160m circa dal p.c.. nel settore della pianura lodigiana l’unità l non è attraversata dai sondaggi alle profondità massime raggiunte di 150 m sotto il piano m. baio, r. bersezio & a. bini 359 campagna. l'unità è costituita da alternanze sottilmente stratificate di limi, sabbie fini limose e limi argillosi associati a limi sabbiosi, sabbie e sabbie fini limose, ad argille di colore nero ricche di sostanza organica, a limi argillosi con tasche di macrofossili ed a livelli di torba. i fossili si rinvengono nella zona di cascina mandella a una profondità di circa -28 m dal p.c. e a sud di somaglia in un sondaggio agip a partire da -120 m circa dal p.c.. i caratteri di questi sedimenti sono del tutto confrontabili con quelli delle litologie tipiche della formazione di san colombano (pleistocene inf. – pliocene?; anfossi et al, 1967). la forte risalita di quota osservata nel settore del colle di san colombano e la geometria profondamente incisa della superficie di erosione al tetto dell’unità l confermano il suo coinvolgimento nella struttura tettonica positiva di san colombano (desio, 1952). discussione sulla base dei dati stratigrafici disponibili nella sezione bidimensionale presentata è possibile unicamente proporre ipotesi relative all'attribuzione stratigrafica delle unità informali individuate. di conseguenza quanto viene suggerito nel seguito costituisce un'ipotesi di lavoro per gli studi in corso attualmente sull'intera pianura lodigiana. l'unità a, contenuta nei terrazzi inferiori del po e del lambro è correlabile con l'unità postglaciale descritta più a nord (bini, 1997) ed è perciò attribuibile al pleistocene superiore olocene. l'unità b è di più difficile attribuzione presentando, alla base, età radiometriche compatibili con l'intervallo di tempo relativo allo lgm alpino (bini, 1997). d'altra parte i sedimenti sommitali appartenenti a questa unità sono tuttora non datati e sulla base delle caratteristiche tessiturali male si prestano ad essere interpretati come sedimenti fluvioglaciali distali. per questo motivo non si esclude che la parte superiore dell'unità b possa essere attribuita alle fasi di ritiro del ghiacciaio relativo allo lgm o addirittura all'unità postglaciale. l'unità c è presente unicamente nel settore del po e presenta alla base età compatibil i con i l pleistocene superiore prelgm. il carattere grossolano dei sedimenti di questa unità induce ad interpretarla come costituita da depositi fluvioglaciali attribuibili quindi all'intervallo temporale occupato dai fluvioglaciali più recenti appartenenti all'allogruppo di besnate. in assenza di datazioni non si può escludere che la porzione sommitale di questa unità possa essere correlata con fasi glaciali più recenti (lgm) (valloni, baio, bedulli 2003). analogamente l'unità d, presente prevalentemente nella pianura lodigiana, risulta attribuibile per età e facies ad un fluvioglaciale correlabile con l’allogruppo di besnate. l'unità e, presente nel settore del po e del colle di san colombano, ha età superiori al limite del metodo 14c. essa è difficilmente suddivisibile al suo interno. considerata la sua estensione stratigrafica, fino all'appoggio sull'unità l, ed i suoi caratteri litologici, non si può suggerire altro se non il fatto che essa comprenda i fluvioglaciali e i f luviali pleistocenici precedenti l’allogruppo di besnate. in posizione geometrica equivalente all'unità e, a nord del settore del colle di san colombano, sono presenti le unità f, g e h. non si posseggono date geocronometriche per queste unità. sulla base dei caratteri tessiturali e litologici esse possono venire interpretate come successioni fluvioglaciali. tra queste la f presenta i depositi più prossimali ed è plausibilmente correlabile con i fluvioglaciali antichi dell'allogruppo di besnate. alla base dell'intera successione fluviale e fluvioglaciale è presente l'unità l, con caratteri attribuibili ad ambienti transizionali e marini. essa è sollevata in corrispondenza del settore del colle di san colombano e profondamente erosa a tetto. di conseguenza essa risulta probabilmente correlabile con la formazione di san colombano affiorante sul rilievo omonimo ed attribuita al pliocene superiore ? pleistocene inferiore. bibliografia anfossi g., boni a., comizzoli g., desio a., gelati r., laureri s., passeri l., petrucci f. e venzo s. (1967) carta geologica d'ital ia al la scala 1:100.000, foglio 60 piacenza (seconda edizione) servizio geologico d'italia, roma bini a. (1997a) problems and methodologies in the study of the quaternary deposits of the southern side of the alps geol. ins., 2/2, 11 – 20, lugano. bini a. (1997b) stratigraphy, chronology and palaeogeography of quaternary deposits of the area between the ticino and olona rivers (italy switzerland) geol. ins., 2/2, 21-46. castiglioni g.b. & g.b. pellegrini (2001) note illustrative della carta geomorfologica della pianura padana suppl. geogr. fis. dinam. quat., iv, 207 pp. desio a. (1952) movimenti orogenici quaternari nella pianura padana rend. acc. naz. lincei fantoni r., massari f., minervini m., rogledi s. & rossi m. (2001) il messiniano del margine sudalpino lombardo: relazioni tra contesto strutturale e stratigrafico deposizionale geol. ins., 6/1, 95-108. lugano. fantoni r., bersezio r. &. forcella f. (2003) alpine structure and deformation chronology at the southern alps po plain border in lombardy boll soc. geol. it., in press. strini a. (2001) gli occhi pollini della brianza orientale: genesi ed evoluzione del fenomeno nel quadro geologico regionale. tesi di dottorato inedita, xiii ciclo, università di milano, 550 pp. stuiver m. & reimer p.j. (1993) radiocarbon calibration program calib rev4 4.2 radiocarbon, 35, 215 230. valloni r., baio m. & bedulli f. (2003) architettura deposizionale del pleistocene superiore nel sottosuolo della media pianura emiliana. geoitalia, 4° forum fist, riassunti, 125 – 127. ms. ricevuto l’11 maggio 2004 testo definitivo ricevuto il 2 novembre 2004 ms. received: may 11, 2004 final text received: november 2, 2004. assetto geologico della successione ... imp.monicabini an itinerary around the apuan alps (tuscany, italy): an example of landscape modelled by different agents monica bini phd student, università di bologna. research carried out at dipartimento di scienze della terra, università di pisa, email: bini@dst.unipi.it abstract: m. bini, an itinerary around the apuan alps (tuscany, italy): an example of landscape modelled by different agents. (it issn 0394-3356, 2005). the combined action of various exogenous agents, together with the powerful endogenous thrust and anthropic activities, have all contributed to the genesis of the current apuan landscape. this landscape is characterised by numerous geosites, among which the most important is certainly the antro del corchia. this karst cavity of international scientific interest, since its opening to the general public has become an important attraction of the park of the apuan alps. however, it tends to be visited purely as an isolated monument, without links with the rest of the area, which offers, also in the immediate surroundings, the chance to observe various other sites of geological or geomorphological interest of comparable scientific value. the exceptional drawing power of the cave could therefore be used to better divulge information relative to those other lesser known nearby sites, which, connected together in an easily followed itinerary, could tell the story of the area from its geological and geomorphological characteristics to the significant impact of man on this landscape. riassunto: m. bini, un itinerario attraverso le alpi apuane (toscana, italia): un esempio di paesaggio modellato da differenti agenti. (it issn 0394-3356, 2005). la concomitante azione di diversi agenti esogeni, unita alla poderosa spinta endogena e all’attività antropica, ha portato alla genesi dell’attuale paesaggio apuano che è caratterizzato dalla presenza di numerosi geositi tra i quali spicca sicuramente l’antro del corchia. la cavità carsica di interesse scientifico internazionale, dal giorno della sua apertura al pubblico è divenuta una importante attrazione del parco delle apuane, ma sfortunatamente è visitata come un monumento isolato, senza legami con il resto del territorio, che offre, anche nelle immediate vicinanze, l’opportunità di osservare altri siti di interesse geologico geomorfologico, di altrettanto valore scientifico. l’eccezionale potere attrattivo dell’antro potrebbe essere sfruttato per diffondere le conoscenze relative a questi siti meno noti, che, collegati tra loro in un facile itinerario, potrebbero raccontare pienamente la storia del territorio dalle peculiarità geologiche a quelle geomorfologiche fino alla incisiva impronta antropica. keywords: geomorphosites, apuan alps, mt. corchia. parole chiave: geomorfositi, alpi apuane, m. corchia. il quaternario italian journal of quaternary sciences 18(1), 2005 volume speciale, 197-201 1. introduction the apuan alps are rich in geosites and particularly geomorphosites, yet today probably the only site that has been adequately exploited, and the only one recognised by the local community and tourists is the antro del corchia. since its opening to the general public in august 2001 it has received a great number of visitors, who however very often see the cave as an isolated monument, without being able to appreciate the natural context within which it is located. the exceptional drawing power of the antro del corchia could be better exploited also to divulge important scientific concepts associated with the presence of other geological-geomorphological sites which taken singly would otherwise be less well known to the public. these sites, linked to the cavern in a single tourist itinerary, could help fully understand the natural and cultural features of the apuan area. these range from its geological peculiarities and modelling by exogenous agents, to the many signs of human influence which have had a significant impact on an area long characterised by mining activities. this paper proposes a touristic-cultural itinerary which makes the most of the apuan area by means of a series of geosites in the surrounding area of the antro del corchia, so as to exploit the already existing tourist flow to the area. the sites included in the itinerary are the following: • levigliani mercury mine • hercynian discontinuity of mt. corchia • antro del corchia • marble quarries of mt. altissimo • padule di fociomboli for some of these sites emphasis has been placed on obviously non-geological features, such as the biological and historical-cultural component, which were considered particularly important and able to increase the value of the single elements. the itinerary, conceived as an informative and discovery route of the area, proposes some points of reflection on the close link between geotopes and biotopes and on the difficult, but not impossible, relation between safeguarding cultural assets and exploitation of natural resources. 2. itinerary the itinerary starts with a visit to the historical mercury mine of levigliani (fig.1). it is located just before entering the village of levigliani, following the 198 m. bini provincial road, near the first turning for levigliani on the road that runs along the side of canale del bosco. along this channel there are the remains of the mining works for the extraction of mercury and cinnabar, whilst on the orographic left there are the entrances to the mining galleries (fig. 2). active from medieval times, when it gave an impulse to the development of the village of levigliani, the mine is today delapidated and risks deterioration and general decay. the interesting mineralisation, which offers a paragenesis unique in italy, follows the quartz veins that reappear in the paleozoic porphyroid schists. of particular importance is the presence of native mercury in metallic drops and cinnabar, which was used in the past for the manufacture of red pigments for the characters of illuminated manuscripts and ecclesiastical books (mancini, 1998). there are numerous rare minerals, some of which, such as leviglianite, were discovered here for the first time. closed down in 1970, after various vicissitudes, the mine is no longer economically viable for extraction, but if opportunely re-equipped and restored it could certainly become an economic resource from the tourist point of view. leaving behind the mine we proceed along the fig. 1 the itinerary. l’itinerario. provincial road to the village of levigliani, from where, with the shuttle bus of the parco delle apuane, we go towards the antro del corchia. during the uphill trip it is possible to see the torrioni del corchia (fig. 3), at the base of which there is the passage between the paleozoic formations of the hercynian basement and the autochthonous calcareous beds (carmignani & giglia, 1983; tucci, 1980). the presence of this landscape, which corresponds to the discontinuity with hercynian discordancy, makes the landscape particularly spectacular, given the different responses of the two rock types to erosion and weathering. above all it is a key point of the area for the understanding of the geological dynamics of the apennines. in fact, it is here where the structurally deepest zone of the northern apennines crops out. from the bus stop, through an artificial entrance created inside an abandoned mining extraction we enter the antro del corchia. with its 50 km and more of galleries and a depth of 1210 m, the cavern is the most extensive italian karst cavity and one of the largest in the world. via a walking itinerary of about two hours we can savour the typical fascination of the hypogeous karst processes, and we can understand important elements of the geological evolution of the apuan mountain chain, such as the various phases of 199an itinerary around the apuan ... stasis and tectonic uplift. in fact, the cave has a complex network of galleries, made up of large horizontal galleries connected by vertical shafts cut along the main joint patterns. the arrangement of the galleries, in three well defined levels, at 1400 m, 1200 m and 850 m a.s.l. reflects three successive moments of tectonic stasis of the apuan chain occurring respectively in the middle-lower pliocene, the lower pliocene, and in the middle-upper pleistocene. the periods of uplift of the apuan alps originated the vertical shafts (piccini, 1991). another undoubtedly typical feature of this area, without which it would be difficult to understand the culture and nature of this landscape, is that of the marble quarries. visible from the versilia coastline, the quarries are chiselled into the landscape and seem to be in an eternal struggle with the carbonatic rock, with its natural cavities. in this particular equilibrium, the exploration of the karst cavities has often identified good sections and vice versa the quarrying activity, above all in the galleries, has sometimes revealed previously unknown branches of the karst cavities. this situation lends a certain importance to the controversial story of the discovery of the antro del corchia, explored for the first time by emilio simi, naturalist and local entrepreneur. for a long time it was thought that simi had discovered a branch of the cavern during marble excavation in his quarries. in reality, as the note of professor l. pilla shows here, it was initial exploration of the karst cavity that prompted simi in 1841 to start quarrying activities. “on the cliffs of mt. corchia that overlook levigliani there was the discovery of a cavern entrance in 1840, which, arousing the curiosity of many, prompted signor simi to undergo operations in order to penetrate the cavity […]. one of the most notable things that was observed was that once the stalactitic crusts covering the walls were removed, these same walls were seen to be of snow-white statuary marble.” the double interest that mt. corchia stimulates, and which makes it an ongoing bone of contention between naturalists and quarrymen, was almost prophetically noted by simi himself who, in 1872, wrote: “if in that beautiful group of mountains which […] crown the rich versilia, one feature deserves more than any other to attract the attention of the naturalist and the greed of the speculator, then that feature is without doubt mt. corchia” (bartelletti & amorfini, 2001). this dual interest is today still very much reflected in the landscape. in fact, near the entrance to the karst cavity, some highly impressive grottoes open in the galleries, veritable cathedrals of marble cut into the mountainside. probably the best known is borra larga, whose entrance is slightly higher up from the main cavern. another example of a different type of mining technique, the open quarry, can be seen along the path towards the padule di fociomboli, where we can observe on monte altissimo a sharply cut summit-level fig. 2 – system of mercury mine of levigliani (photo by s. mancini 1988). impianti della miniera di mercurio di levigliani (foto di s. mancini 1988). fig. 3 the hercynian unconformity of monte corchia. la discontinuità ercinica di monte corchia. 200 quarry. it is one of those which most evidently modify the landscape of the area, it having been opened on the main ridge of the mountain (fig. 4). due to this man-made activity the crest has been lowered and has taken on the typically geometric shape and snow-white colour now very much the emblem of these mountains. more precisely, this white tone is not due only to the marble quarry walls, but also to another feature typical of this area, the ravaneti, pi les of variously shaped blocks and stone debris originating from the worked waste material and which cover wide areas of the flanks of the apuan alps. the ravaneti can be seen at various points of the it inerary, but because of its extension and particular location, the mt. altissimo example is the most impressive. on this ravaneto, as on many others, it is possible to see the steep and winding access roads for the trucks that carry the marble down. in effect, in an impervious area like that of the apuan alps the problem of marble transport has always been of primary importance. for years the way of getting the marble blocks down was by means of the vie di lizza. these were hazardous tracks, furrowed into the steep apuan slopes, along which the marble blocks were hoisted down attached to a large wooden sledge made to slide down on massive trunks, known as "parati", and kept in position with ropes held by a small team of men. only at the end of the 1960s did truck transport on the access roads replace the dangerous technique of "lizzatura". since then the list paths of the area, an important historical feature, r isk disappearing altogether. there is not even an adequate count of how many there are, unlike that carried out in the nearby massa district (bradly & medda, 1989). a few remains of these ancient tracks can be seen from the road leading from the antro del corchia to the village of levigliani. returning to levigliani following the road to pian di lago and passo croce we reach fociomboli and from here, following c.a.i. footpath n°11 we arrive at the padule di fociomboli (peat bog of fociomboli) recognised as a “site of eu interest” due to its notable naturalistic features (fig. 5). the current peat bog is the remains of an ancient glacial lake. a careful look at the landscape enables us to reconstruct the appearance of the area during the last glaciation. one of the southernmost glaciers of the apuan chain occupied this area. it extended along the northern walls of the mountain starting from a height of 1500-1600 m, as shown by the current glacial cirques, and reached, uncovering some rocky spikes, as far down as 700 m along the val terreno. this is m. bini fig. 4 the “cervaiole” quarry in the m. altissimo area. la cava “le cervaiole” su monte altissimo. fig. 5 view of the peatbog of fociomboli. vista panoramica del padule di fociomboli. 201 shown by the presence of a frontal moraine, and at 750 ÷ 800 m in the valley of canale delle fredde, of large boulders with glacial striations (braschi et al., 1986; federici, 1981). in the area of torretta at 1150 m. there is a stationary moraine, that is left by the glacier in a phase of retreat. it is this moraine that has caused the formation of the lake which today has become one of the few peat bogs of the apuan area. located on impermeable rocks, the peatbog of fociomboli is constantly crossed by streams that maintain a regular humidity. in addition, because they originate in the overlying calcareous relief, these waters neutralise the acidity of the soil. the combined effect of these characteristics makes this area a precious habitat for unusual and often rare flora and fauna, clearly indicating the close relationship between geotopes and biotopes (bartelletti & amorfini, 2001) 3. conclusions the itinerary proposed ambitiously intends to show both tourists and members of the local community, how geological, goemorphological and man-made elements of the same area are not detached from each other, and how, even if in constant competition with one another, they overlap and integrate in a common landscape-forming process. the presence within the fociomboli habitat of rare or unusual biological species enables us to observe the close relationship between geotope and biotope, showing how the lack of protection of the physical environment has a negative influence on the biological environment. furthermore, the presence of two mining sites (the altissimo open quarry and levigliani mine) prompt us to reflect on the difficult but not impossible co-existence of this type of activity and the safeguarding of natural resources. in particular, we can see how the quarrying activity can on the one hand be a menace for the local natural resources (the altissimo and antro del corchia), but on the other, it can itself become a cultural resource (levigliani mine, list paths). the idea of this proposed itinerary is to get away from the visit to a single landscape element and move towards a more integrated visit of the nature and culture of an area. this should be a small step in the direction of a knowledge-based approach which contributes to a true safeguarding and exploitation of natural resources that goes beyond an exclusively restrictive conservation. aknowledgements this work was supported by funds of the research project “the environmental resources of the lucca area: an important patrimony to safeguard and exploit” of the fondazione cassa di risparmio of lucca, at the department of earth sciences of the university of pisa. references bartelletti a. & amorfini a. (2001) corchia nel cuore delle apuane suppl. n.148 de “la rivista del trekking”, agosto amichetti editore, parma bradley f. & medda e. (1989) le strade dimenticate vie di lizza e discesa del marmo nelle alte valli massesi amministrazione provinciale di massa e carrara. braschi s., del freo p. & trevisan l. (1986) ricostruzione degli antichi ghiacciai sulle alpi apuane. atti soc. tosc. sci. nat., mem., serie a. 93 pp. 203-219. carmignani l. & giglia g. (1983) il problema della doppia vergenza sulle alpi apuane e la struttura del monte corchia. mem. soc. geol. it. 26, pp. 515525. federici p.r. (1981) the quaternary glaciation on the sea ward side of the apuan alps riv. geogr. it. v. 88, pp. 183 –199. mancini s. (1998) miniere in versilia. storia e itinerari petrarte edizio, pietrasanta. piccini l. (1991) ipotesi sulla origine e sulla evoluzione del complesso carsico del monte corchia corchia 916° congr. fed. spel. it., stazzema. tucci p. (1980) le metamorfiti della "serie scistosa basale" del monte corchia (alpi apuane)period. min. 49, pp. 57-148. an itinerary around the apuan ... sess 2_16022011_tpr2.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 i ciottoli di verrucano dei depositi quaternari situati ad ovest del monte albano e le loro aree sorgenti carlo bartolini dip. sc. della terra, università di firenze corresponding author: c. bartolini <bartolini@unifi.it> riassunto: bartolini c., i ciottoli di verrucano dei depositi quaternari situati ad ovest del monte albano e le loro aree sorgenti. (it issn 0394-3356, 2011) sulla base delle caratteristiche litologiche e sedimentologiche dei depositi di conoide e fluviali dell’area, viene delineata una possibile evoluzione dell’idrografia fra il pliocene superiore e l’olocene. abstract: bartolini c., the verrucano pebbles in the quaternary deposits outcropping to the west of monte albano and their source areas. (it issn 0394-3356, 2011) the fan and fluvial deposits of the area are investigated, mostly referring to their lithologic and sedimentologic features, of in order to work out the hydrographic pattern evolution since upper pliocene times. parole chiave: verrucano, fluvial deposits, monte albano, monte pisano, cerbaie key words: verrucano clasts, monte albano, monte pisano, cerbaie. la vasta area compresa fra monte albano, ad est, e monte pisano-monti d’oltre serchio, ad ovest, e delimitata a nord dalle propaggini dell’appennino e a sud dalle colline in sinistra d’arno (fig. 1) è stata oggetto di numerosi studi, fino al più recente di sarti et al. (2008). l’interesse è motivato dal fatto che essa ospita una successione neogenica assai articolata, anche se solo parzialmente affiorante, il cui spessore totale supera, nel graben dell’elsa, i 2000 m (ghelardoni et al., 1968). le successioni clastiche sia tardo plioceniche che quaternarie sono fortemente caratterizzate dalla ricorrente abbondanza di clasti di verrucano, la cui area sorgente è stata identificata nei conglomerati fig. 1, area di studio. / studied area . 75 78 76 quarzosi della formazione della verruca (trevisan et al., 1971), tuttora estesamente affioranti sul monte pisano e il cui spessore supera i 600 m. data la considerevole resistenza del verrucano all’alterazione sia fisica che chimica, è tuttavia altamente probabile, come vedremo più avanti, che depositi più antichi (in particolare i “ciottoli di montecarlo”, qfl1 in c.g.i., f. 105) siano stati riciclati nelle unità più recenti e segnatamente nei depositi del “ciclo di altopascio-cerbaie”, qt in c.g.i. tale ipotesi comporta un’analisi dell’idrografia e della sua evoluzione, oggetto specifico del presente studio. in sintesi, e trascurando le numerose unità di ambito soprattutto locale, le formazioni affioranti sono: successione medio pliocenica – infra pleistocenica marina con episodi salmastri e continentali (ps in c.g.i.). affiora sul margine meridionale delle cerbaie, sulle colline di cerreto guidi ed estesamente sulle colline di s. miniato e montopoli. sulla scarpata meridionale delle cerbaie, due livelli conglomeratici riferibili al villafranchiano inferiore auctt. sono caratterizzati dalla presenza di clasti derivati sia dalle unità toscane non metamorfiche, macigno incluso (a quel tempo ancora affioranti sul m. pisano), che dal verrucano (menetti, 1978; zanchetta, 1995). •unità fluvio-lacustre (ql in c.g.i.), limitata all’area centro settentrionale del bacino, dove è stata localizzata anche nei sondaggi (chetoni in favenza cerasa et al., 1980). l’età è compresa fra il pliocene inferiore (rusciniano, dallan, 1989) e il pleistocene inferiore. l’unità è vistosamente tettonizzata. “ciclo di montecarlo” (qfl1 in c.g.i). depositi fluviali (granulometria dai limi ai massi) affioranti sulle colline di montecarlo, porcari e gragnano e a nord di lucca. i clasti sono costituiti esclusivamente da verrucano a montecarlo e porcari, da elementi delle unità toscane a gragnano e da elementi delle unità liguri a nord di lucca. l’unità giace in discordanza sul lacustre. la base è tiltata di 2°– 3° verso sud (braccini, 1984). la loro età, per la collocazione stratigrafica, è compresa fra il pleistocene inferiore p.p. e il pleistocene medio p.p. la formazione si caratterizza, come la precedente, per una vistosa pedogenesi plintitica (magaldi et al, 1983). •“ciclo delle cerbaie-altopascio” (qt in c.g.i.): depositi fluviali fortemente caratterizzati dalla presenza di clasti di verrucano. giacciono in discordanza sulle tre unità precedenti. il top deposizionale, localmente conservato, corrisponde alla sommità delle colline delle cerbaie, dolcemente degradante verso ono. per la loro posizione stratigrafica, sono attribuiti al pleistocene medio. l’età è confermata dalla datazione (0,6 ma, arias et al., 1981; 0,4 ma, marcolini et al., 2003) di uno spesso orizzonte di tufiti cineritiche affiorante presso montopoli all’interno della ”formazione di casa poggio ai lecci”, ritenuta correlabile (e.g. mazzanti, 1983), per facies ed età, con i depositi del “ciclo delle cerbaie-altopascio”. come si è visto, i clasti di verrucano sono presenti, fin dal pleistocene inferiore, in almeno tre delle unità sopraelencate. fatta eccezione per i depositi del “ciclo delle cerbaie-altopascio”, quasi interamente conservati, le loro attuali aree di affioramento costituiscono una evidenza molto parziale della loro distribuzione originaria. la paleogeografia del pliocene e del pleistocene inferiore è stata descritta, fra gli altri, da dallan (1988) e da puccinelli (1991). l’area in oggetto doveva essere largamente occupata da un bacino prima in gran parte marino e salmastro e poi lacustre. il monte pisano, più esteso di oggi come appare anche dallo schizzo paleogeografico di ghelardoni et al. (1968) – doveva costituire di gran lunga la principale fonte di alimentazione. anche i ciottoli di unità toscane, sia metamorfiche che non, rinvenuti sulla scarpata meridionale delle cerbaie (zanchetta, 1995), dovevano avere questa provenienza. le unità della successione toscana non metamorfica sono presenti infatti nei sondaggi poggio, zannone e pontetetto, limitrofi al m. pisano, sotto le coperture plio-pleistoceniche (ghelardoni, et al., ibidem). quanto ai marmi, essi affiorano tuttora nel settore settentrionale dello stesso rilievo. si può viceversa escludere che vi fosse allora un apporto da parte del serchio, instauratosi – come vedremo – successivamente. fra il pleistocene inferiore p.p. e il pleistocene medio p.p. (età attribuita ai conglomerati del “ciclo di montecarlo”) il sollevamento generalizzato che caratterizza l’appennino settentrionale in questo lasso di tempo (bartolini, 2003) interessa il anche il m. pisano. ai suoi margini si formano apparati di conoide la cui estensione complessiva doveva essere, sulla base dei residui affioramenti, dell’ordine di c. bartolini fig. 2, fisiografia schematica dei corpi sedimentari pertinenti al “ciclo di montecarlo” (pleistocene inferiore – medio). schematic physiography of the alluvial fan complex related to the “ciclo di montecarlo” (early-middle pleistocene). 77 un centinaio di km2 (fig. 2). la facies sedimentaria del deposito (menetti, 1978), la dimensione dei clasti, la presenza esclusiva di clasti di verrucano negli affioramenti dell’area centro meridionale (montecarlo) e la loro prevalente provenienza da ovest (menetti, cit.) inducono ad escludere un contributo del f. serchio che, se attivo – come ritengono federici & mazzanti (1988) avrebbe apportato clasti di minori dimensioni, caratterizzati da una considerevole varietà di litotipi. il pervenire del serchio nella piana di lucca (fig. 3) è stato successivamente proprio la causa dell’interruzione della messa in posto degli apparati di conoide e dell’erosione della loro porzione prossimale, corrispondente alla piana di lucca e, in parte, al padule di bientina, nel cui sottosuolo sono presenti i depositi lacustri ql (magaldi et al., 1983). l’evento è cronologi-camente riferibile a quando il sollevamento della dorsale appenninica ha iniziato a produrre un apporto clastico. solo allora si sono create le condizioni fisiografiche per lo sviluppo di un collettore interposto fra il rilievo apuano e quello appenninico (coltorti et al. 2008). l’età dei depositi di provenienza appenninica in garfagnana e, per conseguenza del serchio, è generalmente riferita dagli autori ad un generico pleistocene medio. il fatto che lo sviluppo del f. serchio, in quanto legato al sollevamento della dorsale appenninica prospiciente la garfagnana, sia avvenuto posteriormente al sollevamento del monte pisano (i cui cospicui ed esclusivi apporti caratterizzano il ciclo di montecarlo) appare coerente con la ben accertata migrazione verso ne dei processi geodinamici in appennino settentrionale. i depositi fluviali del serchio corrispondono al “ciclo delle cerbaie-altopascio”, caratterizzato da spessori variabili, generalmente modesti ed allora estesi anche all’area di bientina, dove ne rimane traccia (magaldi et al., 1983). sulle cerbaie i depositi poggiano direttamente sul pliocene, senza l’interposizione del pleistocene lacustre (ql in c.g.i.), estesamente affiorante, invece, sui margini della pianura di pescia e sulle pendici del m. albano (“argille e sabbie di mastromarco”, caredio et al., 1995) e presente nei sondaggi di quella pianura per uno spessore di almeno 150 m (menetti, 1978). secondo caredio et al. (cit.) il bacino lacustre villanfranchiano doveva estendersi, verso sud, fino al valdarno; la lacuna dovrebbe essere quindi imputabile, piuttosto che a mancata sedimentazione, ad un processo erosivo che il serchio avrebbe potuto svolgere prima o contestualmente alla messa in posto del “ciclo delle cerbaie-altopascio”. l’attività erosiva del serchio nell’area in sollevamento, costituita dalle pendici occidentali del monte albano, può essere stata determinata dal fatto che il livello di base di questo corso d’acqua era ormai condizionato da quello dell’arno, i cui depositi, a riprova di una considerevole stabilità del suo profilo, hanno uno spessore complessivo di appena una ventina di metri (pozzi certaldo 2 e 3 e pontedera, ghelardoni et al., 1968). nel sottosuolo del padule fucecchio (chetoni in favenza cerasa et al., 1980), i depositi palustri olocenici poggiano direttamente, a circa 20 di profondità dal p.c., sul pliocene. la lacuna riguarda qui, dunque, non solo il villafranchiano lacustre, come sulle cerbaie, ma anche il pleistocene medio. il processo erosivo che in questa depressione ha interessato i sedimenti del “ciclo delle cerbaiealtopascio” potrebbe essere stato operato coni ciottoli di verrucano dei depositi quaternari ... fig. 3, schema della messa in posto del “ciclo delle cerbaiealtopascio” ad opera del serchio (pleistocene medio). pattern of the “ciclo delle cerbaie-altopascio” layout, carried out by the serchio river (middle pleistocene). fig. 4, ipotetico percorso del f. serchio in una prima fase di incisione, successiva alla messa in posto del “ciclo delle cerbaiealtopascio” (pleistocene medio-superiore). possible former serchio river pattern, following the layout of the “ciclo delle cerbaie-altopascio” (middle-late pleistocene). 78 ms. received: testo ricevuto il giuntamente dalle pescie e dal nievole, che oggi si impaludano, oppure dal serchio. le dimensioni e la forma del solco vallivo farebbero propendere per questa seconda ipotesi (fig. 4), sebbene manchino prove dirette. a monte del padule di fucecchio, il serchio avrebbe dovuto transitare dalla zona di altopascio fra il margine meridionale dei depositi del “ciclo di montecarlo” e quello settentrionale dei depositi del “ciclo delle cerbaie-altopascio”. le evidenze di questa eventuale sella di valle morta, orientativamente databile alla seconda metà del pleistocene medio, potrebbero essere state obliterate dai conoidi tardo pleistocenici del rio leccio e del rio s. gallo, situati ad ovest di montecarlo. il lago di sibolla potrebbe essere una residua testimonianza del solco vallivo non colmato – per la sua ubicazione al margine della pianura – dagli apporti delle pescie. l’ultima fase evolutiva corrisponde al ben noto transito del f. serchio nel padule di bientina quale affluente dell’arno (fig. 5). se questa ricostruzione evolutiva ha senso, il rilievo delle cerbaie, che tutti gli autori (e.g. bartolini & pranzini, 1979) hanno interpretato come delimitato su due lati da faglie, sarebbe invece una forma erosiva e precisamente, secondo la definizione di carraro et al. (1995), un “terrazzo libero privo di omologo”. lavori citati arias c., bigazzi g. & bonadonna f.p. (1981) studio cronologico di alcune serie sedimentarie dell’italia appenninica. contr. prelim. realizz. carta neotett. d’italia. c.n.r., p.f. geodinamica, 356, 1441-1448. bartolini c. (2003) when did the northern apennine become a mountain chain? quat. int., 101 – 102, 75 – 80. bartolini c. & pranzini g. (1979) dati preliminari sulla neotettonica dei fogli 97 (s. marcello pistoiese), 105 (lucca) e 106 (firenze). contributi preliminari alla realizzazione della carta neotettonica d'italia, pubbl. n. 251 del p.f. geodinamica, 481-523. braccini m., 1984 – il quaternario delle colline di montecarlo (lu): rilevamento e indagine paleomagnetica. tesi di laurea inedita, univ. di firenze. carraro f., collo g., forno m. g., giardi no m., maraga f., perotto a. & tropea no d. (1995) l'evoluzione del reticolato idrografico del piemonte centrale in relazione alla mobilità quaternaria. acc. naz. sc., scr. doc., 14, 445-461. coltorti m., pieruccini p. & rustioni m. (2008) – the barga basin (tuscany): a record of plio-pleistocene mountain-building in the northern apennines, italy. quat. int., 189, 56-70. dallan l. (1988) – ritrovamento di alephis l irix nelle argille della serie lacustre di monte carlo (lucca) e considerazioni stratigrafiche sui depositi continentali dell’area tra il monte albano e il monte pisano. atti soc. tosc. sc. nat., mem., serie a, 95, 1-17. favenza cerasa m., bixio m., chetoni r., cornieri e., garbari f., montesi m., righetti g., rotini o.t., simonetta a.m., & siniscalchi d. (1980) – progetto pilota per la salvaguardia e la valorizzazione del padule di fucecchio. arti grafiche giorgi e gambi, firenze. federici p.r. & mazzanti r. (1988) – l’evoluzione della paleogeografia e della rete idrografica del valdarno inferiore. boll. soc. geogr. it., serie xi, 5, 573-615. ghelardoni r., giannini e. & nardi r. (1968) – ricostruzione paleogrografica dei bacini neogenici e quaternari della bassa valle dell’arno sulla base dei sondaggi e dei rilievi sismici. mem. soc. geol. it., 7, 91106. magaldi d., bidini d., calzolari c.& rodolfi g. (1983) – geomorfologia, suoli e valutazione del territorio tra la piana di lucca e il padule di fucecchio. annali ist. sper. st. difesa del suolo, 14, 21-108. marcolini f., bigazzi g., bonadonna f.p., centamore e., cioni r. & zanchetta g. (2003) tephrochronology and tephrostratigraphy of two pleistocene continental fossiliferous successions from central italy. journal of quaternary science, 18 (6), 545-556. mazzanti r. (1983) – il punto sul quaternario della fascia costiera e dell’arcipelago di toscana. boll. soc. geol. it., 102 (4), 419-556. menetti f. (1978) – sedimentologia dei depositi fluviolacustri di montecarlo e vinci – lamporecchio (lu), (pt), (fi). tesi di laurea inedita, univ. di firenze. puccinelli a. (1991) – nuovi aspetti dell’evoluzione paleogeografia e tettonica al plio-quaternario della piana di lucca (toscana). geogr. fis. dinam. quat., 14, 171-177. sarti g., testa g. & zanchetta g. (2008) a new stratigraphic insight of the late pliocene-lower pleistocene cycles of the lower valdarno (tuscany, italy). geoacta, 7, 27-41. trevisan l., brandi g.p., dallan l., nardi r., raggi g., rau a., squarci p., taffi l. & tongiorgi m. (1971) – note illustrative della carta geologica d’italia. foglio 105 lucca. serv. geol. d’it., 51 pp. zanchetta g. (1995) – nuove osservazioni sui depositi esposti sul fianco sud-orientale delle colline delle cerbaie (valdarno inferiore, toscana). il quaternario, 8, (2), 291-304. fig. 5, percorso del serchio nel pleistocene superiore-olocene. serchio river pattern in late pleistocene – holocene c. bartolini january 15, 2011 15 gennaio 2011 sess 0_retro e indice edi.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 early to middle pleistocene dynamics of mediterranean plant and mammal communities donatella magri1 & maria rita palombo2 1 dipartimento di biologia ambientale, sapienza università di roma 2 dipartimento di scienze della terra, sapienza università di roma corresponding author: d. magri <donatella.magri@uniroma1.it> abstract: magri d. & palombo m.r., early to middle pleistocene dynamics of mediterranean plant and mammal communities. (it issn 0394-3356, 2011) the mediterranean paleontological record (pollen and large mammals) shows the disappearance of several tree taxa and the development of the modern mixed oak forest from 1.3 to 0.5 ma, while a major turnover at end of the early pleistocene promoted gradual changes in composition and structure of faunal complexes. riassunto: magri d. & palombo m.r., comunità vegetali e mammalofaune alla transizione pleistocene inferioremedio. (it issn 0394-3356, 2011) i dati relativi alla vegetazione e alle faune del mediterraneo indicano che, nel periodo tra circa 1.3 e 0.5 ma, varie piante si estinsero con il deterioramento climatico dei mis 22 e 16, mentre si svilupparono i moderni querceti misti. il cambiamento più significativo nella composizione e struttura della fauna si attuò alla fine del pleistocene inferiore. key words: pollen, mammal fauna, early pleistocene, middle pleistocene, mediterranean basin parole chiave: polline, mammalofauna, pleistocene inferiore, pleistocene medio, bacino mediterraneo it is well known that the transition early to middle pleistocene (mid-pleistocene revolution, mpr, 1.2 -0.6 ma) marks a fundamental change in the earth’s climate system: 41-ka cycles were progressively superseded by a 100-ka rhythm, accompanied by increased amplitude of the climatic oscillations. the cycles were characterized by an asymmetric structure (slow ice build-up, fast melting) thought to be associated with the precessional cycle. precession had an important control on seasonality, in turn affecting the vegetation cover. a number of review papers have recently reported the floristic and vegetational characters of the southern european peninsulas during the early and middle pleistocene (e.g. tzedakis et al., 2006; gonzález-sampériz et al., 2010; bertini, 2010; manzi et al., 2010). several spanish, italian and greek pollen records indicate the possibility of a local persistence of taxa since at least 2 ma bp. in spite of this long-term persistence of plant taxa, clear differences in the composition of vegetation are recorded between the early and middle pleistocene, partly caused by the disappearance of tree taxa, such as tsuga, cathaya, cedrus, parrotia, and carya, and partly by replacements of the dominant taxa. in particular, large portions of subtropical ecosystems disappeared from the mediterranean area by the end of the early pleistocene, and were replaced by forests, dominated by deciduous quercus. however the accompanying trees were rather different from region to region: mostly evergreen quercus in the iberian peninsula (rodríguez et al., 2010), abies, carpinus, and fagus in the italian peninsula (manzi et al., 2010), and carpinus in greece (tzedakis et al., 2006). at the same time, glacial periods were characterized by increasingly open environments, dominated by poaceae, chenopods and artemisia. the vegetational change of the mpr appears as a progressive process spanning the interval 1.2-0.6 ma, even though the extreme climate conditions of marine isotope stage (mis) 16, and most likely also of mis 22, determined the disappearance of several taxa and the development of the modern mixed oak forest. vegetation changes on land were reflected in the assemblages and diversity of mammals. the responses of biota were regionally different, sometimes synchronous but often diachronous. for instance, in europe since at least 1.3 ma bp scattered bioevents (dispersal of large herbivores, which also persisted throughout the middle pleistocene and turnover phases) led to a progressive reconstruction of mammalian faunal complexes that came to an end during the early middle pleistocene (palombo, 2009 and references therein; kahlke et al. 2010). data from taxonomically revised lists of large mammal species from selected spanish, french, italian and greek local faunal assemblages (lfas, i.e., ranging in age ca. 1.3 to 0.5 ma: kostopoulos & koufos 2007; kostopoulos et al., 2007; palombo 2007, 2009 and references therein; berger et al. 2008; carbonell et al., 2008; madurell-malapeira et al., 2010; bertini et al., 144 146 145 2009; kahlke et al., 2010; martinez et al., 2010; toro et al., 2010; palombo & milli, in press) show that this “faunal revolution” was a quite long renewal phase. in the mediterranean regions the mpr period marks a major faunal reconstruction (see e.g. palombo & valli 2005; kostopoulos et al. 2007; palombo, 2007 and references therein). after the early pleistocene “pseudoextinction” phase, large herbivores began to spread across europe with the opening of the forested landscape. several migrations routes from asia and africa, turned out into the italian and iberian peninsulas, whereas faunal interchanges with central europe concerned the french territories, although the time of large mammals was most likely diachronous in the different regions. the late early pleistocene lfas ranging in age ca. 1.3 to 0.9 ma, include both the last representatives of villafranchian lineages at their highest evolutionary stage and representatives, sometimes archaic, of the socalled “galerian” taxa (e.g stephanorhinus hundsheimensis, praemegaceros verticornis, bison shoetensacki), as well as species recorded only in this period (e.g. ammotragus mediterraneus). such a framework of “mixed faunal elements” suggested to several authors that such faunal complex should be a ‘transitional fauna’ (bonifay, 1978, azzaroli et al. 1988), or a peculiar phase of the villafranchian european land mammal age (elma) (“end-villafranchian event”, azzaroli 1995; latest villafranchian’, koufos 2001, or ‘final villafranchian’ spassov 2003) or even a distinct biochron (e.g. protogalerian, caloi & palombo 1995; epivillafranchian, cfr. kahlke, 2007). the lfas dated 1.3 to 0.9 ma show a peculiar composition that make them different from typical late villafranchian and galerian lfas. however, the progressive and diachronous changing of faunal composition and structure, as well the scattered presence of the so-called epivillafranchian taxa in the mediterranean lfas, make it difficult to clearly define any firmly characterised biochron. at the end of the early pleistocene, a number of large mammals appeared, which lasted during the early middle pleistocene, or even later, while few late villafranchian taxa survived in italy in the middle (e.g. pachicrocuta brevirostris, panthera gombazsoegensis), or even late galerian (e.g. equus altidens, equus suessenbornensis). all in all, scattered dispersal bioevents and a few extinctions characterized the time span from about 1.3 to 0.9 ma, while a major turnover occurred at end of the early pleistocene likely triggered by the change in climate system from 41 ka to about 100 ka cycles. intrinsic biotic control (changes in inter intra-specific competition) and resilience of preexisting taxa promoted gradual changes in composition and structure of faunal complexes. references azzaroli a., de giuli c., ficcarelli g. & torre d. (1988) late pliocene to early mid-pleistocene mammals in eurasia: faunal succession and dispersal events. palaeogeography, palaeoclimatology, palaeoecology, 66, 77–100. azzaroli a. (1995) the ‘elephant-equus’ and the ‘endvillafranchian’ events in eurasia. in vrba e.s., denton g.h., partridge t.c. & burckle l.h. (eds), paleoclimate and evolution with emphasis on human origins. yale university press, new haven and london, 311-318. berger g.w., pérez-gonzález a., carbonell e., arsuaga j.l., bermúdez de castro j.m. & ku t.l. (2008) luminescence chronology of cave sediments at the atapuerca paleoanthropological site, spain. journal of human evolution, 55(2), 300-311. bertini a. (2010) – pliocene to pleistocene palynoflora and vegetation in italy: state of the art. quat. int., 225, 5-24. bertini a., ciaranfi n., marino m. & palombo m.r. (2009) proposal for pliocene and pleistocene land– sea correlation in the italian area. quaternary international, 219, 95-108. bonifay m.f. (1978) faunes de transition du pléistocène moyen de france. bulletin du museum d’anthropologie et préhistoire de monaco, 22, 5–15. caloi l. & palombo m.r. (1995) late early pleistocene mammal faunas of italy, biochronological problems. il quaternario, 8 (2) , 391-402. carbonell e., bermúdez de castro j.m., parés j.m., pérez-gonzález a., cuenca-bescós g., ollé a., mosquera m., huguet r., van der made j., rosas a., sala r., vallverdú j., garcía n., granger d.e., martinón-torres m., rodríguez x.p., stock g.m., vergès j.m., allué e., burjachs f., cáceres i., canals a., benito a., díez c., lozano m., mateos a., navazo m., rodríguez j., rosell j. & arsuaga j.l. (2008) the first hominin of europe. nature 452, 465470. gonzález-sampériz p., leroy s.a.g., carrión j.s., fernández s., garcía-antón m., gil-garcía m.j., uzquiano p., valero-garcés b. & figueiral i. (2010) steppes, savannahs, forests and phytodiversity reservoirs during the pleistocene in the iberian peninsula. rev. palaeob. palynol., 162, 427-457. kahlke r.d. (2007) late early pleistocene european large mammals and the concept of an epivillafranchian biochron. courier forschungs-institut senckenberg, 259, 265-278. kahlke r.d., garcia n., kostopoulos d.s., lacombat f., lister a.m., mazza p.a., spassov n & titov v.v. (2010) western palaearctic palaeoenvironmental conditions during the early and early middle pleistocene inferred from large mammal communities, and implications for hominin dispersal in europe. quat. sci. rev., doi:10.1016/j.quascirev. 2010.09.020 kostopoulos d.s. & koufos g.d. (2007) – palaeoecological remarks on plio-pleistocene mammalian faunas. comparative analysis of several greek and european assemblages. in: proceedings of the international colloquium rcmns, mediterranean early to middle pleistocene dynamics of mediterranean ... 146 ms. received: testo ricevuto il neogene cyclostratigraphy in marine-continental palaeoenvironments, patras, greece. geological society of greece, special publications 9, 139-150. kostopoulos d., palombo m.r., alberdi m.t. & valli a.m. (2007) pliocene to pleistocene large mammal diversity and turnover in north mediterranean region: greek, italian and iberian peninsula. geodiversitas, 29 (3), 401-419. koufos g.d. (2001) the villafranchian mammalian faunas and biochronology of greece. bollettino della societa` paleontologica italiana, 40 (2), 217–223. madurell-malapeira j., minwer-barakat r., alba d.m., garcés m., gómez m., aurell-garrido j., ros -montoya s, moyà-solà s. & berástegui x., (2010) the vallparadís section (terrassa, iberian peninsula) and the latest villafranchian faunas of europe, quaternary science reviews, doi:10.1016/ j.quascirev.2010.09.020 manzi g., magri d. & palombo m.r. (2010) earlymiddle pleistocene environmental changes and human evolution in the italian peninsula. quaternary science reviews, doi:10.1016/j.quascirev.2010.05.034. martínez k, garcia j., carbonel e., agustí j., bahain j-j., blain h-a., burjachs f., cáceres i., duval m., falguères c., gómez m. & huguet r. (2010) a new lower pleistocene archeological site in europe (vallparadís, barcelona, spain), pnas 107(13), 562567. palombo m.r (2007) which boundary for the quaternary period and pleistocene epoch? the contribution to the debate given by turnover patterns in large mammalian complexes from north-western mediterranean region. quaternaire, 18(1), 35-53. palombo m.r. (2009) a scenario of human dispersal in the northwestern mediterranean throughout the early to middle pleistocene. quaternary international, 223224, 179-194. palombo m.r. & milli s. (in press) mammalian fossil recod, depositional setting, and sequence stratigraphy in the middle – upper pleistocene of roman basin. il quaternario. palombo m.r. & valli a.f.m. (2005). highlighting the early-middle pleistocene transition in italian and french large mammal faunas: similarities and faunal renewals. in head m.j. & gibbard p.l. (eds) earlymiddle pleistocene transitions: the land-ocean evidence. geological society, london, special publications, 247, 263-276. spassov n. (2003) the plio-pleistocene vertebrate fauna in south-eastern europe and the megafaunal migratory waves from the east to europe. revue de paléobiologie, 22, 197-229. toro i., martinez-navarro b. & agusti j. (eds) (2010) – occupaciones humanas en el pleistoceno inferior y medio de la cuenca de guadix-baza. monografias archeologia., junta de la andalusia, 582 pp. tzedakis p.c., hooghiemstra h. & pälike h. (2006) the last 1.35 million years at tenaghi philippon: revised chronostratigraphy and long-term vegetation trends. quat. sci. rev. 25, 3416-3430. d. magri & m.r. palombo january 15, 2011 15 gennaio 2011 sess 1_160211.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 post-lgm features along the ionian calabrian margin (southern italy) massimo zecchin1, silvia ceramicola1, emiliano gordini1, michele deponte1 & salvatore critelli2 1 ogs, sgonico (ts), italy 2dipartimento di scienze della terra, università della calabria, arcavacata di rende (cs), italy corresponding author: m. zecchin <mzecchin@ogs.trieste.it> abstract: zecchin m. et al., post-lgm features along the ionian calabrian margin (southern italy). (it issn 03943356, 2011) chirp subbottom profiles performed on the ionian calabrian margin, southern italy, allow the recognition of an irregular seabed topography. it shows both concave-up and concave-down profiles in any dip section and a local stepped geometry, with gradients between 1° and >20°. the steeper slopes are interpreted as relicts of palaeo-coastal cliffs generated by wave action during the post-lgm relative sea-level rise. in particular, the formation of a slope locally exposed between ca. 75 and 100 m water depth is inferred to be related to the melt-water pulse (mwp) 1a (14.3 14.0 ka bp), whose depth range corresponds closely with that of this slope, assuming no subsidence or uplift. a transgressive model for high-gradient settings and stepped sea-level rise is proposed. coastal cliffs develop and retreat due to wave erosion during phases of slow relative sea-level rise. during phases of very high rate of relative sea-level rise, coinciding with melt-water pulses, cliffs tend to be overstepped, drowned and not completely eroded. the present model may be effective in reconstructing stepped sea-level rises and the evolution of shelf areas during late quaternary time. riassunto: zecchin et al., caratteristiche successive all’ultimo massimo glaciale lungo il margine ionico della calabria (italia meridionale). (it issn 0394-3356, 2011) profili sismici chirp rilevati lungo il margine ionico della calabria, italia meridionale, permettono di riconoscere una irregolare topografia del fondo mare. essa mostra profili con la concavità rivolta sia verso l’alto che verso il basso in ogni transetto orientato perpendicolarmente alla linea di costa, e localmente una geometria a gradini, con gradienti tra 1° e >20°. i pendii più inclinati sono interpretati come relitti di paleofalesie generate dall’azione dell’onda durante la risalita del livello relativo del mare successivo all’lgm. in particolare, la formazione di un pendio localmente esposto tra circa 75 e 100 m di profondità è interpretata essere collegata al “melt-water pulse” (mwp) 1a (tra 14.3 e 14 mila anni fa), la cui variazione di profondità corrisponde con quella di questo pendio assumendo ne subsidenza ne sollevamento. e’ proposto un modello trasgressivo per contesti di gradiente elevato ed innalzamento del livello del mare a passi successivi. la falesie si sviluppano e retrocedono a causa dell’azione erosiva dell’onda durante fasi di lenta risalita del livello relativo del mare. durante le fasi in cui il tasso di risalita del livello relativo del mare è molto elevato, coincidenti con i “melt-water pulses”, le falesie tendono ad essere oltrepassate, annegate e non completamente erose. il presente modello può essere efficace nel ricostruire risalite a gradini del livello del mare e l’evoluzione delle aree di piattaforma continentale durante il tardo quaternario. key words: calabrian continental shelf, post-lgm transgression, chirp subbottom profiles parole chiave: piattaforma continentale calabra, trasgressione successiva all’ultimo massimo glaciale, profili sismici chirp the present study is focused on features developed during the post-lgm transgression on the narrow, high-gradient shelf off the crotone area (southern italy) and on the southern part of the amendolara palaeo-island (api). in particular, peculiar features such as submerged coastal cliffs and a seabed typified by irregular step-like geometry characterize the present area. we recognized this area as suitable to develop a transgressive model for very high-gradient settings characterized by coastal cliff development and irregular topography. such a model may be useful in recognizing and understanding the features and style of transgression and variations in its rate, particularly for the post-lgm glacio-eustatic rise. the seabed morphology of the ionian calabrian margin reflects the complex interplay between the south-eastward migration of the calabrian accretionary wedge since mid-miocene and the rapid uplift of onshore and shallow shelf areas since mid-pleistocene (malinverno & ryan, 1986; bonardi et al., 2001). the uplift, documented by a staircase of marine terraces in the subaerial crotone basin, still continues today, and it has been characterized by a rate that, in this area, approximated 1 m/ka (zecchin et al., 2004; antonioli et al., 2006). the geophysical data used for this study consist of chirp subbottom profiles (sbp) acquired across the ionian shelf margin (ism) and the southern side of the api. the information coming from the acoustic character of the sbps have been combined with the morpho-bathymetric information coming from a high-resolution multibeam dataset. two seismic units (unit 1 and unit 2), separated by 71 72 72 ms. received: testo ricevuto il a key stratal surface (unconformity u) are recognizable in the considered sbps, both along the ism and api. unit 1 is the lower unit, and is truncated above by u. this unit is almost opaque along the ism, but it may show basinward-inclined to variably folded reflectors along the api. a prograding wedge, typified by basinward-inclined oblique reflectors that downlap on a less inclines reflector, is recognizable between 90 and 130 m water depth at the margin of the api and locally along the ism. the unconformity u separates the older unit 1 from the younger unit 2, and is characterized by both concaveand convex-up profiles in dip direction. it exhibits a variable dip from 0.5° to a maximum of ca. 30° at relict scarps locally exposed. one of these features is recognizable between ca. 75 and 100 m water depth along both the ism and api. unit 2 is up to 30 m thick and locally appears as a prograding wedge whose reflectors downlaps on the unconformity u. in other cases, it shows onlap relationships with u. the unconformity u, which truncates a unit characterized by variably inclined reflectors (unit 1), is overlain by a younger unit (unit 2), and is locally exposed forming scarps, represents a surface of regional significance. in particular, it is interpreted as a wave ravinement surface (wrs), produced by wave erosion on the shelf during the post-lgm transgression, truncating a pliopleistocene unit. the prograding wedge located between 90 and 130 m water depth in unit 1 is interpreted as the lowstand wedge. the deposition of unit 2 above u has been related to the postlgm glacio-eustatic rise. the scarp recognizable between 75 and 100 m water depth along both the ism and api is interpreted as a partially preserved palaeo-coastal cliff. moreover, such a depth closely matches with the depth range of melt-water pulse (mwp) 1a, during which the eustatic sea-level rose from 96 to 76 m below present sea-level, between 14.3 and 14.0 ka bp (liu & milliman, 2004). this suggests a correlation between the stepped sea-level rise following the lgm and the preservation of coastal cliffs along the continental margins. in particular, it is suggested that the palaeo-coastal cliff recognized between 75 and 100 m water depth generated and started to recede during a phase of slow eustatic rise, and was then overstepped and partially eroded during a subsequent phase characterized by very rapid eustatic rise (i.e. the mwp 1a), otherwise its progressive dismantling would have occurred. this consideration is valid assuming a rough balance between regional uplift and subsidence of glacio-hydro-isostatic origin as shown by pirazzoli et al. (1997). younger accelerations and decelerations of sea-level rise, such as mwp-1b (58-45 m below present sea level, 11.5-11.2 ka bp), could be responsible for the formation of some shallower scarps found in our sbps. a transgressive model for high-gradient shelves during the post-lgm glacio-eustatic rise is proposed. where the transgressed topography is very steep, coastal cliffs developed and retreated during the initial phase of relatively slow sea-level rise, due to wave erosion acting at the toe of the cliff. during phases of very high rate of sea-level rise, coinciding with melt-water pulses, cliffs tended to be overstepped and not completely eroded by the wrs. this model needs further testing in other contexts characterized by highgradient shelf topography, but it has the potential to be useful in recognizing variations in the rate of sea-level rise and in general in reconstructing the late quaternary evolution of shelf to coastal areas. references antonioli f., ferranti l., lambeck k., kershaw s., verrubbi v. & dai pra g. (2006) late pleistocene to holocene record of changing uplift rates in southern calabria and northeastern sicily (southern italy, central mediterranean sea). tectonophysics, 422, 23-40. bonardi g., cavazza w., perrone v. & rossi s. (2001) calabria-peloritani terrane and northern ionian sea. in: g.b. vai and i.p. martini (eds.) anatomy of an orogen: the apennines and adjacent mediterranean basins. kluwer academic publishers, bodmin, 287306. liu j.p. & milliman j.d. (2004) reconsidering meltwater pulses 1a and 1b: global impacts of rapid sealevel rise. j. ocean univ. china, 3, 183-190. malinverno a. & ryan w.b.f. (1986) extension in the tyrrhenian sea and shortening in the apennines as a result of arc migration driver by sinking of the lithosphere. tectonics 5, 227-245. pirazzoli p.a., mastronuzzi g., saliège j.f. & sansò p. (1997) late holocene emergence in calabria, italy. mar. geol., 141, 61-70. zecchin m., nalin r. & roda c. (2004) raised pleistocene marine terraces of the crotone peninsula (calabria, southern italy): facies analysis and organization of their deposits. sed. geol., 172, 165185. january 15, 2011 15 gennaio 2011 m. zecchin et al. << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /none /binding /left /calgrayprofile (dot gain 20%) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /error /compatibilitylevel 1.4 /compressobjects /tags /compresspages true /convertimagestoindexed true /passthroughjpegimages true /createjobticket false /defaultrenderingintent /default /detectblends true /detectcurves 0.0000 /colorconversionstrategy /cmyk /dothumbnails false /embedallfonts true /embedopentype false /parseiccprofilesincomments true /embedjoboptions true /dscreportinglevel 0 /emitdscwarnings false /endpage -1 /imagememory 1048576 /lockdistillerparams false 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/pdfxoutputintentprofileselector /documentcmyk /preserveediting true /untaggedcmykhandling /leaveuntagged /untaggedrgbhandling /usedocumentprofile /usedocumentbleed false >> ] >> setdistillerparams << /hwresolution [2400 2400] /pagesize [612.000 792.000] >> setpagedevice imp.d'alessandro rreessppoonnssee ooff mmaaccrroobbeenntthhooss ttoo cchhaannggeess iinn ppaallaaeeooeennvviirroonnmmeennttss iinn tthhee lloowweerr--mmiiddddllee pplleeiissttoocceennee ((lluuccaanniiaa bbaassiinn,, ssoouutthheerrnn iittaallyy)) aassssuunnttaa dd’’aalleessssaannddrroo11,, rraaffaaeell llaa ppeerrnnaa && nneerrii cciiaarraannffii dipartimento di geologia e geofisica, università di bari campus universitario, via orabona 4, 70125 bari, italia 1corresponding author e-mail address: tina@geo.uniba.it abstract the lucania basin is part of the bradano trough, whose internal sectors were subject to continuous subsidence during the early pleistocene. this led to the deposition of a muddy sequence with a thickness in excess of 500 m in the montalbano jonico area (lucania). during the middle pleistocene, a general shallowing took place, starting from the more internal sectors of the lucania basin. the regressive succession exposed in the badland area of montalbano is candidate of the early/middle pleistocene boundary stratotype. the restored sequence was obtained from selected partial sections correlated by means of nine volcaniclastic layers, each of them characterised by distinct macrofauna assemblages. a gap of unknown thickness (probably a few tens of metres) divides the succession in two intervals: the lower one (a) consists of muddy deposits, the upper one (b) of muddy to sandy deposits, overlain by organogenic calcarenites in the uppermost part. integrated palaeoecologic, taphonomic and ichnologic analyses were performed in order to reconstruct bathymetric fluctuations and environmental changes, based on biotic responses. palaeocommunities from the lower interval point to background environments with moderate sedimentation rate, low hydrodynamic level and low oxygen content, punctuated by numerous events of mass deposition. palaeodepths range from the upper bathyal to the shelf break. through interval b, palaeodepths range from the shelf break to the inner shelf-nearshore. this interval includes genetically different shell beds. the inferred background environments are characterised by sedimentation rates and water-energy ranging from low to high, under fully aerobic conditions. like in the lower interval, blanketing events are numerous. within the general regressive trend, several fifthand sixth-order cyclothems are recognised throughout the sequence. vertical changes in the fossil communities within individual cycles indicate changes in water depth that parallel climatic fluctuations, as proved by climatic indicators in interval b. further, the sea-level curve proposed in the present work matches well the local oxygen isotope curve, but the bathymetric range of some of the cycles suggests a tectonic control superimposed on the climatic influence. riassunto il bacino lucano fa parte della fossa bradanica i cui settori interni furono interessati, nel corso del pleistocene inferiore, da una subsidenza pressoché continua che determinò l’accumulo di depositi prevalentemente fangosi, affioranti per uno spessore di oltre 500 m nell’area di montalbano jonico (lucania). nel pleistocene medio ebbe inizio una fase regressiva a partire dai settori più interni del bacino. la successione regressiva di montalbano è candidata come stratotipo per il limite pleistocene inferiore/medio. la sequenza è stata ricostruita sulla base di numerose sezioni parziali, correlate attraverso nove livelli guida vulcanoclastici, a loro volta caratterizzati da associazioni faunistiche diverse. un’interruzione di entità non valutabile (probabilmente di poche decine di metri) divide la successione in due intervalli: quello inferiore (intervallo a) è rappresentato da depositi fangosi, quello superiore (intervallo b) è costituito da depositi da fangosi a sabbiosi, passanti a calcareniti organogene nella parte sommitale. analisi paleocologiche, tafonomiche ed icnologiche, svolte in maniera integrata, sono state utilizzate per dedurre fluttuazioni batimetriche ed evoluzione paleoambientale. le paleocomunità dell’intervallo inferiore, permettono di dedurre ambienti di background caratterizzati da tasso di sedimentazione generalmente moderato, bassa energia e basso contenuto di ossigeno, sottoposti a numerosi eventi di deposizioni in massa e localizzati a profondità variabili fra il batiale superiore ed il margine di piattaforma. nell’intervallo b, le paleobatimetrie variano tra il margine di piattaforma e la transizione al nearshore. la presenza di shell beds di varia genesi è tipica di questo intervallo. gli ambienti di background sono caratterizzati da tasso di sedimentazione e livello di energia idrodinamica da basso ad alto e da buona ossigenazione. come nell’intervallo inferiore, sono numerosi gli eventi di blanketing. nell’ambito di una generale tendenza regressiva, sono stati riconosciuti diversi ciclotemi di quinto e sesto ordine; tale ciclicità è evidenziata dai cambiamenti, in verticale, delle associazioni fossili. il controllo climatico è confermato dalla presenza di indicatori climatici fra le faune dell’intervallo b. esiste, inoltre, un buon accordo fra i cicli dedotti sulla base del presente studio e la locale curva isotopica dell’ossigeno, anche se l’ampiezza batimetrica di alcuni cicli suggerisce la sovrapposizione di un controllo tettonico a quello climatico. keywords: benthic communities, sea level changes, oxygen changes, early-middle pleistocene, lucania basin. parole chiave: comunità bentoniche, fluttuazioni del livello marino, fluttuazioni nell’ossigenazione, pleistocene inferiore e medio, bacino lucano. il quaternario italian journal of quaternary sciences 1166(1bis), 2003, 167-182 11.. iinnttrroodduuccttiioonn the bradano trough (fig. 1) is part of a foredeep basin, extending from molise to the gulf of taranto. during the lower pleistocene a high sedimentation rate and an almost continuous downlift led to the deposition of thick clastic sequences. particularly, along the apenninic margin of the lucania basin (i.e. the southernmost part of the foredeep), active subsidence caused the deposition of hemipelagic clays interfingered with muddy turbiditic deposits. a generalized shallowing phase started in the middle pleistocene resulting in a relative shallowing of the basin, testified by a shift from upper slope to shelf depositional environments. the pleistocene marine succession cropping out in the badlands area of montalbano (fig. 2) contains fossil assemblages, that clearly indicate short-term cyclic palaeobathymetric changes. as a whole, the sequence shows 168 a. d’alessandro, r. la perna & n. ciaranfi a general regressive trend, from upper slope to inner shelf deposition (ciaranfi et al, 1997). this succession is over 500 m thick and mostly silty-clayey. except for an isolated section about 15 m thick, referred to the “large” gephyrocapsa biozone, the sequence is referred to the “small” gephyrocapsa biozone and to the pseudoemiliania lacunosa biozone, providing a reference for the selection of the lower/middle pleistocene boundary stratotype (ciaranfi et al. 1997, maiorano et al., in press). the present study investigates the palaeoenvironmental evolution inferred from the fossil assemblages in order to discriminate between the cyclically modulated climatic changes, and the tectonic control. a palaeoecological analysis of the macrofauna has been combined with ichnological and taphonomic observations, with the aim of clarify changes in depth, oxygen content, and sedimentation rate. molluscs have been primarily used due to their good distribution and abundance in the studied succession; nevertheless, environmental data have been also obtained from other groups (e.g., echinoderms, decapods, bryozoans, planktonic gastropods). such an integrated approach enables a more detailed stratigraphic resolution within a framework of predictable relations between biota and sedimentation dynamics. 22.. ssttrraattiiggrraapphhyy the “argille subappennine” formation crops out in the montalbano jonico area in a monoclinal, gently sedipping structure. in spite of several mainly n-s and nesw trending faults, a continuous succession (fig. 3) was reconstructed by numerous partial sections over an area of about 2.5 km2 (ciaranfi et al., 2001, fig. 5). nine volcaniclastic beds are present (fig. 2), ranging from a few centimetres to 50 cm in thickness. they consist of pure ashes or volcaniclastic-rich sands, occasionally with pumice clasts as redeposited material. this volcanic material is referred as have been generated by an alkaline undersaturated volcanism (de rosa in ciaranfi et al., 1996). the volcaniclastic beds (v1-v9) are associated to benthic palaeocommunities pointing to different bathymetric trends, and this allows them to be used as marker beds (ciaranfi et al., 2001, fig. 7). the recognition of alternating darker and lighter intervals (3-6 m thick) all through the section and the presence of a dark, laminated horizon rich in delectopecten vitreus (gmelin) provided further tools for correlation (ciaranfi et al., 2001, figs. 5, 7). a gap of unknown thickness (probably a few tens of metres) divides the restored succession in two intervals. the lower interval (aa), about 180 m thick, consists of dark grey, massive to locally laminated mud (i.e., silty clay to clayey silt), commonly bioturbated and with dispersed macrofossils. the upper interval (bb), over 300 m thick, consists of muddy to sandy shelf deposits, generally with abundant macrofauna, and including thick shellbeds. this interval is capped by transgressive continental conglomerates. 33.. mmeetthhooddss three main approaches have been used to unravel the depositional evolution of the study sequence. fig. 1 structural map of southern italy and location of the montalbano jonico sequence. fig. 2 view of the montalbano jonico badlands with the thickest volcaniclastic layers v5 (lower arrow) and v7 (upper arrow). 169response of macrobenthos to changes ... taphonomic observations allowed to infer the main depositional patterns (i.e., background versus event depositions, sedimentation rate, etc.). palaeoichnologic analysis has been useful to infer fluctuations in the oxygen content, and palaeoecology has been mainly applied to reconstruct bathymetric changes. the main difficulty encountered during this study was the extremely time-consuming field work, due the need of recording in continuum taphonomic features, trace fossil distribution, faunal composition and distribution, as well as sedimentological features (raw field data and the list of the taxa are available from the authors on request). the outcrop surface was first cleaned from the weathered part to expose fresh mudrock over a belt 50100 cm wide throughout the succession. mudrock was then removed down to a depth of 10-30 cm and examined. most aragonitic skeletons and, to a less extent, even the calcitic ones, had been weakened by dissolution, frequently fractured by compaction or are preserved as deformed steinkerns. a number of bulk-samples (50-100 kg of sediment) has been taken for a quantitative palaeoecological analysis, although it often turned out that the benthic palaeocommunities (i.e associations) suffered more or less preservational bias. accordingly, most analyses were carried on a qualitative or semi-quantitative base. whenever possible, fossil associations were paralleled to recent mediterranean biocoenoses or to the atlantic communities. the mediterranean biocoenoses were defined (pérès & picard, 1964) qualitatively and each of them is identified by a group of characteristic species, irrespective of their abundance. this bionomic approach, successfully adopted in the mediterranean area, is the most suitable tool for the identification of biotopes (basso & corselli, 2002) and for a more precise bathymetric location of palaeocommunities. 44.. ttaapphhoonnoommyy 44..11 ddeessccrriippttiioonn iinntteerrvvaall aa. the main taphonomic feature of this interval is highly dispersed autochthonous fossils. except for larger specimens, fossils are partly decalcified and preserved as more or less flattened steinkerns, often internally lined by pyrite (pl. 1, fig. 1). pyrite linings, or pyrite steinkerns of the smaller components (pl. 1, figs. 4, 7), can occur in several unrelated taxa, e.g. molluscs, echinoids, decapods (pl. 1, fig. 10), and foraminifers (pl. 1, fig. 14). fossils, often articulated and without signs of abrasion or encrustation, lack any preferred orientation in plane view and are concordant to bedding plane in transversal view. numerous loosely packed concentrations have been regarded as intrinsic biogenic concentrations (kidwell et al., 1986) including three thin, dark, mostly laminated intervals rich in delectopecten vitreus. the mud-pecten shells, concentrated in discontinuous pavements and layers, are pristine, concordant, densely packed, commonly preserved as closed or slightly shifted valves, mostly with an internal pyrite lining, single, and rarely in butterfly position. extrinsic biogenic concentrations are recorded by several small accumulations of small angular bioclasts due to biological activity (pl. 2, fig. 13). several obrution events are inferred by completely fig. 3 reconstructed sequence of montalbano jonico. a and b are the stratigraphic intervals considered in the present work. 170 a. d’alessandro, r. la perna & n. ciaranfi 171response of macrobenthos to changes ... fig. 1 abra longicallus (scacchi). articulated, compressed and partially fragmented specimen with internal pyrite lining. interval a, scale bar 0.5 cm. fig. 2 abra nitida (müller). specimen preserved in butterfly position. interval a, scale bar 0.5 cm. fig. 3 bathyspinula excisa (philippi). articulated, compressed and partially fragmented specimen. interval a, scale bar 0.5 cm. fig 4 delicate erect bryozoan colonies with pyrite infilling. interval b, scale bar 0.5 cm. fig. 5 undetermined “small shrimp” preserved as a muddy steinkern with minor pyrite mineralization. interval a, scale bar 2 mm. fig. 6 amphiura chiajei forbes. fully articulated specimen with arms closed around the disc. interval b (top part), scale bar 2 cm. fig. 7 ebalia nux norman & milne edwards. pyritized carapace steinkern with skeletal remains in dorsal (a) and ventral (b) view. this specimen was fully articulated but appendages were lost during the bulk-sample treatment. interval a, scale bar 2 mm. fig. 8 brissopsis lyrifera (forbes). undeformed muddy steinkern. interval b, scale bar 1 cm. figs. 9, 11 brissopsis lyrifera (forbes). strongly compressed and fragmented tests with attached raised spines. minor pyritization in fig. 11. interval a, scale bars 1 cm. fig. 10 goneplax rhomboides (linnaeus). spectacularly preserved and fully pyritized specimen. note the eyestalks in the cephalic region (arrows). interval b, scale bar 0.5 cm. fig. 12 geryon sp. fully articulated specimen with pyrite infilling in the smaller appendage cavities. interval a, scale bar 1 cm. fig. 13 funiculina quadrangularis (pallas). long fragment with inner pyrite lining. interval a, scale bar 1 cm. fig. 14 discospirina italica (costa). complete test with pyritized chamber infilling. interval a, scale bar 2 mm. fig. 15 brissopsis lyrifera (forbes). detail of articulated and raised spines. interval a, scale bar 0.5 cm. articulated crustacean skeletons and by strongly flattened infaunal echinoid tests, with some diagenetic features, such as pyritization, due to decay of organic matter. another evidence of obrution events comes from obliquely embedded and deformed echinoid tests, occasionally preserved with articulated and raised spines, which are signs of escape attempts (pl, 1, figs. 9, 11, 15). erosional, reddish silt-bearing surfaces with or without dispersed shells indicate episodic rise of waterenergy. rare, poorly evident, thin lenses of dispersed to densely-packed biogenic elements occur as sedimentological concentrations, mainly consisting of hard parts of benthic organisms (e.g., small bivalves and large foraminifers, pl. 2, fig. 3), pteropods (pl. 2, fig. 1), terrestrial leaves (pl. 2, fig. 6) and posidonia oceanica (linnaeus) leaves (pl. 2, figs. 2, 5). two, 10-20 cm thick, graded beds with erosional base occur in the uppermost part of interval a. they are mud-supported, rhodolith-rich accumulations including large and abraded shell fragments of shelf origin, testifying mass deposition events. iinntteerrvvaall bb. fossils are more abundant and better preserved than in the lower interval, but are still dispersed. the hardparts of epifaunal organisms may be encrusted, moderately bioeroded and locally abraded. the degree of disarticulation is generally low to medium, except for some shell beds in the upper part of the sequence, where bivalves are highly disarticulated and exhibit a moderate degree of fragmentation. burial events by muddy plumes are numerous and well documented by the same biostratinomic signatures as in the lower interval associated with common pyrite steinkerns (e.g. minute gastropods, bryozoans, foraminifer tests) or patinas (e.g. pyrite coatings of echinoid spines, internal linings of bivalves, etc.). different genetic types of shell beds occur. some intrinsic biogenic concentrations, such as the associations of erect bryozoans-small pectinids, protula wormscelleporiform bryozoans, and neopycnodonte, record burial episodes of sessile palaeocommunities. commonly, the appearance of these concentrations is abrupt, without any evident basal erosional surface. in rare cases, the erect-bryozoan shell beds are complex, showing a thin, sharp-based layer consisting of densely packed fragments of delicate branching, mud-tolerant bryozoans, overlain by clumps of erect bryozoans. below v3 (fig. 3), the erect bryozoan-small pectinid shell beds alternate with less fossiliferous intervals containing loosely packed to dispersed ditrupa tubes or, more rarely, articulated shells of corbula (in both cases without preferred orientations). rare extrinsic biogenic concentrations, produced by scavengers or deposit-feeders, were encountered. in other cases the original concentration has been partially distorted by high-energy events (e.g. hiatella arctica (linnaeus) and aequipecten opercularis-bearing beds), resulting in mixed concentrations. bivalve remains are densely packed and concordant to bedding, both articulated (closed shells to butterfly position) and disarticulated, complete, and the pectinids are also partially encrusted. a single case of diagenetic concentration was encountered about 15 m above the v2 volcaniclastic layer. it consists of a population of isocardia, whose shells form a loosely packed pavement. this concentration resulted from compression, as indicated by the strong deformation and fragmentation of closed valves. pure sedimentologic concentrations, formed by storm-induced currents, are represented by small lenses of bioclasts, sharp-based silty layers and, upwards, by discontinuous shell pavements (fig. 4) and by few complex shell beds resulting from multiple events. these ➧ 172 a. d’alessandro, r. la perna & n. ciaranfi thick shell beds, occurring in sandy-silty intervals, mainly consist of aequipecten opercularis (linnaeus) valves which are closely-packed, highly disarticulated, convex-upward, sometimes stacked, broken and encrusted. moreover, scattered arctica islandica (linnaeus) and ophiuroid lenses occur in the coarser interval. the bivalves consist of articulated and empty valves, and the amphiura chjaiei (forbes) skeletons are preserved perfectly articulated and with arms closed around the disc (pl. 1, fig. 6). 44..22 iinntteerrpprreettaattiioonn in most cases, background and episodic processes can be clearly distinguished (discrete signatures of speyer & brett, 1991). however, in the upper interval, the taphonomic features reflect more complex interactions, mostly due to higher energy settings (on average) and to more diverse biostratinomic responses to dynamics of sedimentation. the biostratinomic signatures in the lower interval allow to infer low-energy background palaeoenvironments located well below the maximum storm wave base and characterized by low to moderate sedimentation rates, soft and, less commonly, soupy substrates. this is clear evidence of frequent mud blanketing events by deposition of muddy plumes and rarer winnowing episodes by weak bottom currents. the diagenetic features, particularly the common pyrite linings and rarer pyrite cores, suggest low dysaerobic conditions within the sediment (brett & baird, 1986), not always related to burial events. in the upper interval, the biostratinomic signatures prevail over the diagenetic ones, thus allowing a greater accuracy when inferring palaeobathymetry. lowand high-energy taphofacies the latter indicative of settings located above the maximum storm wave base alternate. deeper sett ings, where taphonomic signatures are less evident and distinctive, are better defined on palaeoecological grounds. the higher energy 173response of macrobenthos to changes ... fig. 1 winnowed concentration, mostly consisting of pteropod shells. the dark spots are plant remains. interval a, scale bar 2 cm. fig. 2 winnowed concentration of posidonia oceanica (linnaeus) leaves. interval a, scale bar 1 cm. fig. 3 winnowed concentration of cyclammina cancellata brady tests. interval a, scale bar 0.5 cm. fig. 4 chondrites targionii (brongniart). interval a, scale bar 1 cm. fig. 5 leaf fragment of posidonia oceanica (linnaeus). interval a, scale bar 1cm. fig. 6 quercus sp. leaf. interval a, scale bar 1 cm. figs 7, 10 cross-sections of zoophycos spreiten. interval a, scale bar 1 cm. fig. 8 teredolites isp. in a carbonized wood. interval a, scale bar 1 cm. fig. 9 chondrites patulus fischer-ooster. interval a, scale bar 1 cm. fig. 11 track-like trace. interval b, scale bar 1 cm. fig. 12 cladichnus isp. (detail of a polished surface). interval a, scale bar 0.5 cm. fig. 13 burrow filled with shell debris (extrinsic concentration). interval a, scale bar 0.5 cm. figs. 14, 15 problematica. interval a, scale bars 0.5 cm. ➧ fig. 4 – interval b (upper part). discontinuous pavements of convex-up valves of aequipecten opercularis. some of them are heavily encrusted by corallinaceans and/or serpulids (arrows). taphofacies are indicative of middle and inner shelf settings. numerous winnowing episodes led to firmer substrates suitable for the settlement of sessile fast-growing bryozoans and their epibionts, which characterise this community. in few cases, event-concentrations of mudrelated delicate bryozoans provided the firm substrate colonized by the erect bryozoans (taphonomic feedback). in the uppermost part of sequence, taphonomic features suggest inner shelf, maybe transitional to shoreface, environments. in particular, the arctica and amphiura lenses testify reworking of both dead and living benthic organisms and their catastrophic burials during transgression culminating in a marly sediment with neopycnodonte clumps. the stratigraphic distribution of taphofacies points to clear short-term bathymetric fluctuations, within a general shallowing trend. levels with abundant pyrite steinkerns within small skeletal cavities suggests episodic dysaerobic microenvironments due to rapid burial of organic material. 55.. ppaallaaeeooiicchhnnoollooggyy 55..11 ddeessccrriippttiioonn iinntteerrvvaall aa. this interval is generally bioturbated with a highly variable bioturbation index (nil to mottled). distinctive trace fossils are visible only when they contrast in colour with the host rock. where the sediment is massive, mottling is doubtful, though more than likely. distribution of ichnotaxa and bioturbation index (bi) are reported in appendix. all through interval a, a few centimetres-thick layers, highly bioturbated by chondrites intricatus (brogniart) may occur near silty surfaces with taphonomic evidence of burial events. in the lower part, some intervals up to few metres thick are characterised by dispersed and diverse ichnotaxa (2-4 bi): chondrites (pl. 2, figs. 4, 9), cladichnus (pl. 2, fig. 12) and subordinately alcyonidiopsis are dominant. in the middle part, chondrites-zoophycos intervals may alternate with massive (mottled?) beds, or with phycosiphon-bearing strata (bi 5). zoophycos (pl. 2, figs. 7, 10), which has a discontinuous stratigraphic occurrence, disappears a few metres above the v2 layer (appendix). poorly bioturbated intervals (bi 2 to 3) with small thalassinoides, planolites and undetermined track-like traces (pl. 2, fig. 11) are also present. in the upper part, the degree of bioturbation is generally lower and ichnotaxa are mostly represented by different chondrites ichnotaxa. in three cases, chondrites intricatus is markedly thin and dispersed until its disappearance, which happens in dark, laminated delectopecten vitreus-rich sediment (fig. 5). the thickest of these intervals (fig. 6) coincides with the first occurrence of gephyrocapsa sp. 3 (upper part of the interval a). iinntteerrvvaall bb. bioturbation is poorly defined, except for the volcaniclastic beds, where scolicia (bi 3-5) or thalassinoides (bi 2-3), due to the highly contrasting colour, are clearly evident. more generally, thalassinoides and planolites, sometimes associated with track-like traces, are present, although uncommonly. bioerosion is abundant in the middle-upper part of the sequence and, more generally, in the shallower settings. 55..11 iinntteerrpprreettaattiioonn ichnologic features of interval a (i.e., high abundance and diversity of chemichnia) point to general dysoxic conditions in the muddy sediment, except for the well oxygenated phycosiphon-rich massive package. an increasing oxygen content in the bottom water and/or in the pore water may be inferred by the decrease of chemichinia diversity, as well as by the increased size of traces in the middle-upper part of the sequence. zoophycos has been found in regressive tracts (inferred by the palaeoecological analysis), thus confirming its relation with raising sedimentation rates (brett, 1998). the thin layers with minute ch. intricatus that occur throughout the muddy interval, are interpreted as colonization episodes triggered by abrupt burial of organic matter. the aforementioned, laminated, delectopecten vitreus-rich sediment are an interesting case, since this situation records the exaerobic biofacies of savdra & bottjer (1987): i.e. depletion of oxygen and sealing of the mud bottom by biomats allow specialized chemosymbiotic epifauna to live in an abenthic regime (savdra, et al., 1991). the bacterial mats might have provided a suitable bottom for the epibyssate life habit of d. vitreus. this hypothesis envisages d. vitreus as a facultative chemosymbiotic organism, although no data are found in the literature on this habit. however, hickman (1984) reports a deep-water facies, characterised by mud-pectens, in laminated, organic matter-rich sediments. a second hypothesis suggests colonization by opportunistic shelled organisms during short oxic pulses (sageman et al., 1991), but the absence of any kind of infauna remains unexplained. for interval a, an oxygen curve (fig. 5) has been reconstructed, based on the vertical distribution of oxygen-related ichnoassociations. for the d. vitreus interval containing the first occurrence of gephyrocapsa sp.3, a more detailed curve (fig. 6) was constructed based also on macrobenthic organisms sensitive to oxygen conditions. the ichnologic features of interval b point to fully aerobic conditions. rare cases of moderate dysaerobic conditions are suggested by the occurrence of abundant alcyonidiopsis and small concentrations of faecal pellets, which may be related to local obrution events (blanketing). 66.. ppaallaaeeooeeccoollooggyy 66..11 ddeessccrriippttiioonn iinntteerrvvaall aa. most of the invertebrate macrofauna consists of dispersed molluscs and, subordinately, of burrowing echinoids, macroforaminifers, decapods, and octocorals. the most typical bathyal molluscs are bathyspinula excisa (philippi) (pl. 1, fig. 3), katadesmia confusa (seguenza), delectopecten vitreus, abra longicallus (scacchi) (pl. 1, fig. 1), dentalium agile sars, and entalina tetragona (brocchi), taxa also known from other coeval bathyal sequences (di geronimo & la perna, 1997, di geronimo et al., 1997). in the short basal section, these species are particularly common, but they become more and more dispersed upwards until they are replaced by a monotypic chondrites intricatus (bi 4-5) association. in the remaining part of the interval, the strictly bathyal species and their palaeocommunities exhibit a somewhat discontinuous vertical 174 a. d’alessandro, r. la perna & n. ciaranfi 175response of macrobenthos to changes ... fig. 5 interval a. palaeobathymetric curve, main palaeocommunities and oxygen curve. each palae-ocommunity is named after the most typical faunal component(s). oxygenation levels in the bottom water are according to bromley (1996, fig. 12.1): aer = aerobic, dys = dysaerobic (upper and lower), ex = exaerobic. log abbreviations: dv = delectopecten shell-beds, m = mottling, obr = obrutions (main events), t = turbidites, tl = thin muddy turbidites (main events), w = winnowing (main events). distribution, alternating with taxa characteristic of shallower slope facies such as aporrhais uttingerianus (risso) , a. serresianus (michaud), nassarius cabrierensis (fontannes), kell iel la abyssicola (forbes), parvicardium minimum (philippi), hyalopecten similis (laskey), and fissidentalium rectum (gmelin). d. vitreus exhibits a peculiar distribution. it is uncommon throughout interval a, but forms closely packed concentrations in three cases (see taphonomy), giving rise to a monotypic palaeocommunity preserved in laminated layers. shells mostly belong to fully grown individuals. this species belongs to a group of thin-shelled pectinids with a deep-water distribution on muddy bottoms and facultative epibyssate habits. there is a certain systematic confusion about d. vitreus (gmelin, 1791) due to the supposed existence of a distinct species, d. abyssorum (sars, 1878), which would have slightly different ecologic needs. robba (1996) kept these two species distinct, but there is no general agreement about this distinction. in the present paper, both taxa are considered as a single mud-tolerant species referred to as d. vitreus. echinoids are almost exclusively represented by brissopsis lyrifera (forbes). decapods include the bathyal species ebalia nux norman & milne edwards and the eurybathic goneplax rhomboides (linnaeus). in some thin intervals (1-2 m), a monospecific association of the macroforaminifer discospirina italica (costa) (pl. 1, fig. 14) occurs as loosely packed concentrations. bathyal octocorals are recorded by rare remains of funiculina quadrangularis (pallas) (pl. 1, fig. 13) and isidella elongata (esper), the latter being locally common. iinntteerrvvaall bb. fauna from this interval is richer and referable to several palaeocommunities of clearly different bathymetric settings. however, changes in palaeocommunity composition are mostly gradual, making any clear-cut separation of different palaeocommunities rather difficult. moreover, the biotic response to environmental changes, particularly to edaphic factors, is so marked in shelf settings, that fossil associations highly differ from each other, and it is neither possible to outline general compositional features, nor to describe each community one by one. in this paper, a few case studies 176 a. d’alessandro, r. la perna & n. ciaranfi fig. 6 interval a. oxygen curve for the delectopecten vitreus package containing the fo (arrow) of the calcareous nannofossil gephyrocapsa sp. 3 (sensu rio, 1983). the curve is based on the vertical distribution of oxygen-related trace fossils and on other faunistic and taphonomic features. 177response of macrobenthos to changes ... fig. 7 interval b. palaeobathymetric curve and main associations. each association is named after the most typical faunal component(s). log abbreviations: dv = delectopecten shell beds, m = mottling, obr = obrutions (main events), t = turbidites, w = winnowing (main events), bs = sequence boundary, ts = transgressive surface. symbols: sun = interglacial peak, snowflake= glacial peak. 178 a. d’alessandro, r. la perna & n. ciaranfi are reported to characterise the main environments, related to sea-level fluctuations and encompassing different system tracts of sequence stratigraphy. a polyspecific middle-inner shelf molluscan palaeocommunity (between v2 and v3) contains aequipecten opercularis (linnaeus), venus multilamella (lamarck), plagiocardium papillosum (poli), turritella ex gr. communis risso, t. mediterranea monterosato, trochids (commonly encrusted by bryozoans), and small rhodoliths. below v5, another similar community is represented by arctica islandica, isocardia cor (linnaeus), large cardiids, and a. opercularis. near the top of the sequence, a sharp environmental change is recorded by a middle shelf muddy bottom palaeocommunity (turritella ex gr. communis association) abruptly replaced by an inner shelf-shoreface sandy bottom palaeocommunity (a. opercularis-a. islandica association). the latter is recorded by parautochthonous elements packed in a thick shell bed with complex internal structure, overlying an irregular erosional surface. a protula-encrusting bryozoan palaeocommunity is referred to outer shelf low-stress biotopes with cohesive substrates and low sedimentation rates. upwards, near the v5 layers, the protula-bryozoan palaeocommunity evolves into a palaeocommunity characterised by large-sized hiatella arctica, a weak borer in stiff sediments. this ecological succession culminates with the neopycnodonte cochlear palaeocommunity. nassarius edwardsi (p.fischer) is an associated species which, in this upper part of the succession, replaces the deeper taxon n. cabrierensis. another case study are erect bryozoan-small pectinid palaeocommunities, dominated by adeoniform and r e t e p o r i f o r m growth forms. they alternate with opportunistic softbottom palaeocommunities characterised by ditrupa arietina (müller) or corbula gibba (olivi). 66..22 iinntteerrpprreettaattiioonn in the montalbano succession, palaeocommunities and their stratigraphic successions provide the best tool to identify cyclic sealevel changes and key surfaces of the short-time cyclothems. such changes are recorded throughout the succession. benthic palaeocommunities from interval a are clearly indicative of upper slope environments, with a maximum depth of about 500 m. only near the middle part of this interval, the fauna suggests a shelf-margin setting (fig. 5). within this bathymetric range, several cyclic fluctuations involving changes in sedimentation rate and substrate consistency, are recorded. in these deep water settings, the fluctuations are mainly recognised basing on the relative dominance or abundance of typically bathyal species vs shelf margin and deep shelf species in the associations. palaeocommunities from interval b record outerto inner-shelf palaeocommunities, except for a nassarius cabrierensis-dominated palaeocommunity, located a few metres above the volcaniclastic layer v4, which suggests a transitional-to-slope setting, as is also indicated by the presence of rare bathyal species. like in the lower interval, palaeoecological evidence indicates cyclic sea-level changes (fig. 7), by a distinct change of shelf palaeocommunities. the occurrence, in the shallower phases, of the so-called “boreal guests” arctica islandica and pseudamussium septemradiatum (müller) together with numerous hiatella arctica specimens, whose size is similar to that of the recent north atlantic ones, suggests a climatic control for these fluctuations. sea-level lowstands are recorded by the polyspecific molluscan palaeocommunities occurring in thin horizons between v2 and v3 and below v5. near the top, the lowstand is represented by an erosional surface (ts, fig. 8) capped by a thick shell-rich bed. during deepening phases, protula worms-celleporiform bryozoan palaeocommunities flourished in outer fig. 8 – interval b (top). a = silts with turritella ex gr. communis. b = simple shell bed with arctica islandica, aequipecten opercularis and t. ex gr. communis. sb = sequence boundary. ts = transgressive surface. c = complex shell bed. d = sands with a. islandica and amphiura chiajei lenses. shelf low-stress biotopes characterised by cohesive substrates and a low sedimentation rate. near the v5 layers, the ecological replacement starting with faunas indicative of inner shelf environments, culminates with the neopycnodonte cochlear palaeocommunity that indicates the maximum flooding surface. the inversion of the trend up section is pointed out by gradually shallower palaeocommunities related to higher sedimentation rates. the neopycnodonte palaeocommunity is recurrent in interval b and highlights the positions of the maximum flooding surfaces in several cyclothems. conversely, shallowing phases are highlighted by the ditrupa arietina or corbula gibba opportunistic communities that flourish in condition of high turbidity (di geronimo & robba, 1989) and high sedimentation rate and inhabit soupy-soft substrates. these conditions are common during the late highstand system tracts. the frequent intercalations within these communities of erect-bryozoan communities (that have contrasting ecological needs) can be explained by periodic winnowing that removed the soupy boundary layer and exposed firmer substrates suitable for such sessile communities of fast-growing organisms. the vertical succession of communities confirms the upwards shallowing trend. 77.. ddiissccuussssiioonn changes in the taphonomic and palaeoecological features allowed to infer a sea-level curve for the earlymiddle pleistocene (figs. 5, 7). the curve is composed of short-term fifth(100 ka) and sixth-order (40ka) cycles, as evaluated from the local oxygen isotope curve (brilli in d’alessandro et al., 2002). the ba-thymetric range of cycles is about 100 m, although in so-me cases it considerably exceeds (over 200 m) this value. throughout interval b, the climatic control is proved by the occurrence of “cool water” molluscs indicators in the shallower phases and, occasionally, by “warm water” indicators in the deeper ones, i.e. two teleosteans (girone & varola, 2001) and a serpulid (sanfilippo, in press). conversely, no palaeoclimatic indicator occurs in the lower interval. however, there is a good match between the sea level curve and the oxygen isotope curve, which at present does not cover all the sequence. the same type of control can be then supposed for the whole sequence of montalbano. however, in some intervals, the bathymetric range is too high to be exclusively ascribed to climatic effects; therefore, a tectonic control must be an additional factor. the best example occurs near the volcaniclastic layer v4, where the bathymetric range exceeds 200 m and the kind of palaeocommunities i.e., palaeocommunities dominated by attached forms preserved as loosely to closely packed concentrations versus palaeocommunities of mostly vagile elements, occurring as dispersed assemblages are indicative of a low and high sedimentation rate respectively. the high sedimentation rate events occur during abrupt deepening phases (as inferred by the palaeocommunity succession) or follow them, thus contrasting with the expected sedimentation pattern during the transgressive system tract. this can be attributed to uplift of the continental areas surrounding the foredeep basin and resulting in increased terrigenous supply. hence, the “cycle” is exalted in magnitude and broken down in tectonically controlled steps. in interval a, palaeobathymetric ranges of sea level fluctuations are less detailed due to the intrinsic features of both deep-water fauna and biotopes. anyway, in analogy of the upper interval, the largest cycles are also regarded as partially tectonic-controlled. the ichnological assemblages from the lower interval allowed to draw a curve of changes in the bottom water oxygen content (figs. 5, 6). it is worth noticing that the dysaerobic/anaerobic events occur during maximum flooding phases, as a result of the decreased oxygen supply to the bottom water during interglacial periods. the present study also allows to elucidate the palaeoecological significance of two types of associations hitherto unknown in the l i terature, i .e. the delectopecten vitreus and the discospirina italica communities. in the studied sequence, d. vitreus is commonly present in muddy bottom, bathyal palaeocommunities, as is known in the literature (d’alessandro & de marco, 1993; robba, 1996; di geronimo & la perna, 1997), but this species, when recorded in monotypic palaeocommunities, seems to be related to exaerobic conditions, as suggested by ichnofossil analysis. the “exaerobic model” may be thus adequate to explain the absence of all kind of infauna, including the chondritesmakers. this hypothesis would entail a facultative chemosymbiotic feeding mode for d. vitreus. discospirina italica is an unusual deep-water macroforaminifer (adams, 1973, 1976; hottinger, pers. comm., 2001), whose ecology is poorly known. monotypic associations of discospirina, in the studied sequence, have been found during the early highstands, in slope (interval a) and outer shelf/slope settings, characterising an increased sedimentation rate related to shallowing. there is an overall good match between the inferred cycles and those obtained from other palaeontological studies, although at different degree of resolution. benthic foraminifers provide a detailed reconstruction of bathymetric changes in particular for the upper interval, while the same group allows a better resolution of oxygen changes through the interval a (stefanelli, in press), giving a curve more or less equivalent to that inferred by the ichnofossils. fish otoliths are a fairly good bathymetric indicators in the deeper settings (girone, 2000). tapho-facies analysis was particularly useful in shallower environments (soldani, 2000; ciaranfi et al., 2001). the integrated palaeontological analyses applied to the montal-bano sequence support the statement by brett (1998) that fossils provide a good tool to identify key surfaces and sedimentation dynamics within sequences, while the sequence stratigraphy model provides a predictive framework to interpret probable causes of biotic changes. aacckknnoowwlleeddggmmeennttss we thank the referees b.m. cita (milano university) and f.t. fürsich (würzburg university) for improving of the manuscript and helpful comments, and a. girone (bari university) for determination of crustaceans. the authors were funded by the italian ministry of university and scientific research (grant miur 40%, prof. n. ciaranfi). 179response of macrobenthos to changes ... rreeffeerreenncceess adams c.g., 1973 some tertiary foraminifera. in: hallam a. (ed.), atlas of palaeobiogeography. elsevier, amsterdam, p. 455-468. adams c.g., 1976 larger foraminifera and the late cenozoic history of the mediterranean region. palaeogeography, palaeoclimatology, palaeoecology, 2200, p. 47-66. basso d. & corselli c., 2002 community versus biocoenosis in multivariate analysis of benthic molluscan thanatocoenoses. rivista ital iana di paleontologia e stratigrafia, 110088: p. 153-172. brett c.e., 1998 sequence stratigraphy, paleoecology, and evolution: biotic clues and responses to sea-level fluctuations. palaios, 1133, p. 241-262. brett c.e. & baird g.c., 1986 comparative taphonomy: a key to paleoenvironmental interpretation based on fossil preservation. palaios, 11: p. 207-227. bromley r.g., 1996 trace fossils. biology, taphonomy and applications. chapman & hall, p. 361. ciaranfi n., d’alessandro a. & marino m., 1997 a candidate section for the lower-middle pleistocene boundary (apennine foredeep, south italy). in: w. naiwen and j. remane (eds), proceedings ot the 30th international geological congress, 1111, p. 201-211. ciaranfi n., d’alessandro a., girone g., maiorano p., marino m., soldani d. & stefanelli s., 2001 pleistocene sections in the montalbano jonico area and the potential gssp for early-middle pleistocene in the lucania basin (southern italy). memorie di scienze geologiche dell’università di padova, 5533, p. 67-83. ciaranfi n., marino m. sabato l., d’alessandro a. & de rosa, 1996 studio geologico-statrigrafico di una successione infra e mesopleistocenica nella parte sud-occidentale della fossa bradanica (montalbano jonico, basilicata). bollettino della società geologica italiana, 111155, p. 379-391. d’alessandro a. & de marco a., 1993 bionomic analysis of two upper pliocene communities from southern italy. beringeria, 88, p. 109-137. d’alessandro a., brilli m., ciaranfi n., girone a., la perna r., maiorano p., marino m., soldani d., stefanelli s. & turi b., 2002 lower-middle pleistocene sea-level changes in the lucania basin (southern italy) as recorded by fossil association. in: ciaranfi n. (ed.), abstract convegno aiqua “elementi cronostratigrafici per una correlazione fra successioni marine e successioni continentali: stato delle conoscenze e nuovi dati, p. 1718. di geronimo i., d’atri a., la perna r., rosso a., sanfilippo r. & violanti d., 1997 the pleistocene bathyal section of archi (southern italy). bollettino della società paleontologica italiana, 3366, p. 189212. di geronimo i. & la perna r., 1997 pleistocene bathyal molluscan assemblages from southern italy. rivista ital iana di paleontologia e stratigrafia, 110033, p. 389-426. di geronimo i. & robba e., 1989 the structure of benthic communities in relation to basin stability. memorie dell’accademia dei lincei, 8800,, p. 341-352. girone a., 2000 the use of fish otoliths for paleobathymetric evaluation of the lower to middle pleistocene deposits in southern italy. bollettino della società paleontologica italiana, 3399 (2): 235242. girone a. & varola a., 2001 fish otoliths from the middle pleistocene deposits of montalbano jonico (southern italy). bollett ino della società paleontologica italiana, 4400, p. 431-443. hickman c.s., 1984 composition, structure, ecology and evolution of six cenozoic deep-water mollusk communities. journal of paleontology, 5588 (5): p. 1215-1234. kidwell s.m., fürsich f.t., aigner t., 1986 conceptual framework for the analysis and classification of fossil concentrations. palaios, 11, p. 228-238. maiorano p., marino m., di stefano e. and ciaranfi n., submitted calcareous nannofossil events in the lower-middle pleistocene transition at montalbano jonico section (southern italy) and odp site 964 (ionian sea), and their calibration with oxygen isotope and sapropel stratigraphy. rivista italiana di paleontologia e stratigrafia. pérès j.m. & picard j., 1964 nouveau manuel de bionomie benthique de la mer méditerranée. recuil des travaux de la station marine d’endoume, 3311 (47), pp. 137. rio d., 1982 the fossil distribution of coccolithophore genus gephyrocapsa kamptner and related pliopleistocene chronostratigraphic problems. in: prell, w.l., gardner, j. v. et al. (eds.), initial reports of the deep sea drilling project, 6688, p. 325-343. robba e., 1996 autoecology of some pliocene thinshelled pectinids. in cherchi a. (ed): autoecology of selected fossil organisms: achievements and problems, bollettino della società paleontologica italiana, spec. vol. 33, p. 159-174. sageman b.b., wignall p.b., kauffman e.g., 1991 biofacies models for oxygen-deficient facies in epicontinental seas: tool for paleoenvironmental analysis. in: einsele g., ricken w., seilacher a., (eds.): cycles and events in stratigraphy springer-verlag, berlin, 542-564. sanfilippo r. (in press) climatic response in the genus plagostegus philippi, 1844 from plio-pleistocene to recent mediterranean, with description of a new species (polychaeta, serpulidae). bollettino della società paleontologica italiana. savdra c.e. & bottjer d.j., 1987 the exaerobic zone, a new oxygen-deficient marine biofacies. nature, 327: p. 54-56. savdra c.e., bottjer d.j., and seilacher a., 1991 redox-related benthic events. in einsele g., ricken w., seilacher a. (eds.): cycles and events in stratigraphy springer-verlag, berlin, p. 524-541. soldani d., 2000 utilizzo e limiti di applicabilità delle tafofacies nelle analisi di bacino. tesi di dottorato, università di bari, unpublished, pp. 114. speyer s.e. & brett c.e., 1991 taphofacies controls. in: all ison p.a. & briggs d.e.g. (eds.) taphonomy: releasing the data locked in the fossil record. vol. 99 of topics in geobiology, , p. 501-545. stefanelli s. (in prep.) early-middle pleistocene benthic foraminifera microhabitats as response to oxygen variations: proxy of oxygen content? 180 a. d’alessandro, r. la perna & n. ciaranfi 181response of macrobenthos to changes ... a pp en di x 182 a. d’alessandro, r. la perna & n. ciaranfi a pp en di x a pp en di x b io tu rb at io n in de x (b i) a nd d is tr ib ut io n of ic hn ot ax a in in te rv al a . in di ce d i b io tu rb az io ne ( b i) e d is tr ib uz io ne d eg li ic hn ot ax a ne ll’ in te rv al lo a sess 2_16022011_tpr3.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 geo-environmental analysis for the sustainability of campi flegrei landscape clelia cirillo1, marina maura calandrelli1, giovanna acampora1, roberto calandrelli2 & luigi scarpa3 ¹cnr – istituto di biologia agroambientale e forestale, napoli 2cnr – istituto di studi giuridici internazionali, napoli 3università di napoli federico ii scuola di master di pianificazione urbana, napoli corresponding author: m.m. calandrelli <maura.calandrelli@ibaf.cnr.it> abstract: cirillo c. et al., geo-environmental analysis for the sustainability of campi flegrei landscape. (it issn 0394-3356, 2011) the soil is not only an abiotic component but it is also the site where important processes of ecosystem functioning take place; it is the result of the combined action of climate, organisms, morphology and time action on the rocks; the man interferes on natural processes thereby causing further changes. it is, however, a natural resource being unable to regenerate, and thereby in planning activities it is important to use maps able to represent the evolution of land use and obtain dynamic data supporting decision-making in the sustainable management strategies of landscape and environmental assets. riassunto: cirillo c. et al., analisi geoambientale per la sostenibilità del paesaggio dei campi flegrei. (it issn 0394-3356, 2011) il suolo non è solo una componente abiotica ma anche il sito dove si svolgono importanti processi di funzionamento dell’ecosistema; esso è il risultato dell’azione combinata del clima, degli organismi, della morfologia e del tempo sulle rocce; l’uomo interferisce sui processi naturali apportando ulteriori modificazioni. esso è, però,una risorsa naturale incapace di rigenerarsi, e per questo è importante avvalersi, nelle attività di pianificazione del territorio, di cartografie in grado di rappresentare l’evoluzione dell’uso del suolo e ricavarne dati dinamici a supporto delle decisioni delle strategie di gestione sostenibile dei patrimoni paesaggistici-ambientali. key words: soil, historical cartography, gis parole chiave: suolo, cartografia storica,gis the purpose of this paper is to define a methodology for land analysis aiming at identifying environmental changes caused by the anthropic activity through a vision having a multidisciplinary nature of the abiotic and biotic components. this is achieved through the reconstruction of a cartographic model representing the historical evolution of land and environment. such an approach, in course of experimentation, was tested on a precise land sample: the regional park of campi flegrei. the choice was dictated by the presence of morphologically interesting features of the landscape from the soil system point of view. campi flegrei offer a unique landscape featuring interweaving an environmental framework and anthropic stratifications favoured by climate and soil fertility. the use of valuable crops, including vines, has characterized and still characterizes the agricultural productivity of this area; campi flegrei historical vines constitute a mark on the landscape area able to trace the history of land use and describe the its changes. soil is a complex evolving system, structured by physical, chemical, biological and time factors to be analysed with respect to the relationship occurring between the elements (bullini et al., 1998). the transformation of land use is listed as one of the causes of deterioration as the change of land from natural to semi / natural or artificial utilization involves the loss of fertile soil because of the negative environmental impacts, which cause the fragmentation of the territory, the loss of biodiversity, alterations of the hydrogeological cycle and microclimatic alteration. the study of the evolutive dynamics of the structure of the flegrean soil, achieved by comparing historical maps, is an example of analysis of land and environment changes; by integrating data on morphological evolution of the flegrean soil, extracted from georeferenced historical maps in gis environment and from the most recent ones in a digital terrain model (dtm), it may be obtained the representation of the soil surface together with the changes of use. the study provided for the selection according to classes as identification tools of the essential elements being present in the area following the provisions of the corine land cover and corine biotopes classification systems. the comparative methodology made use of the land utilization map 93 94 94 ms. received: testo ricevuto il of the year 1907 realized on the basis of the igm cartography interpretation and murat cadastral map of 1811 in order to have accurate data on the socio-economic, anthropological, and environmental aspects of southern society in the nineteenth century. from the map of naples province (de lorenzo r. et al., 2008) on the vines areas in murat age, extracted from documents of that time being indicative of the crops classes, it results that campi flegrei are within the areas specialized in viticulture. the thematic mapping was carried out according to data from murat cadastre, made by the land valuations produced and contained in the summary tables grouped by municipality; this shows how historical registers are very useful for the reconstruction of regional planning. these administrative tools are based on maps that reproduce the territory divided into particles, uniform minimum unit referred to the ownership, the intended use and the quality of the soil, exactly reproducing the geometric elements of the land, buildings, roads, rivers, cultivated fields and uncultivated land. also the igm military cartography shows a synthetic and at the same time detailed image of the territory whose physical components as well as physical and legal components are reported with extreme precision. aiming at the cartographic comparison it is fundamental to georeference the historical maps, a task that requires the application of innovative methods of reading the contents of metric and topological maps of ancient maps thus allowing to have the same reference system (marchetti, 2000), thereby obtaining the extraction of homogeneous geographic data being therefore comparable with each other. at the same time the inclusion of geomorphologic information of the area, historical climate series and ecological information on these biotic components will allow us to have an overview of the factors relating to forcings which jointly with anthropic actions determine the soil evolution. the outcome of the application of the methodology allowed to recognize and understand the signs in the area being the result of the organizational structures dating back to the past, traces which have partially lost spatial and/or functional relationships of those systems. references bullini l., pignatti s. & virzo de santo a. (1998) ecologia generale. utet, torino. de lorenzo r.,galluccio f. & scarpa l. (2008) cartografia e catasto napoleonico. uno studio sulla provincia di napoli. atti seminario dalla mappa al gis, brigati, genova. marchetti m. (2000) metodologie per una cartografia di uso del suolo multilivello e multiscala: analisi e sperimentazione applicativa. relazione finale, documentazione gruppo di lavoro “uso e copertura del suolo”, centro interregionale, roma. c. cirillo et al. january 15, 2011 15 gennaio 2011 sess 0_retro e indice edi.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 the early to early middle pleistocene stenonoid horses from italy maría teresa alberdi1 & maria rita palombo2 1departamento de paleobiología. museo nacional de ciencias naturales, csic, madrid, spain 2dipartimento di scienze della terra, universita` degli studi di roma ‘‘la sapienza’’, and cnristituto di geologia ambientale e geoingegneria, roma, italy corresponding author: m.r. palombo <mariarita.palombo@uniroma1.it> abstract: alberdi, m.t., palombo m.r., the early to early middle pleistocene stenonoid horses from italy. (it issn 0394-3356, 2011) at least five stenonoid horses have been recorded in the early to early middle plestocene italian faunal assemblages: equus livenzovensis, equus stenonis, equus stehlini, equus altidens and large sized equids generally referred to as the so-called “equus ex gr. e. bressanus e. suessenbornensis”. equus altidens and equus suessenbornensis are a rather long surviving species, ranging in age from the latest villafranchian (pirro fu) to the late galerian, and are sometimes found together in the same local faunal assemblage. this study mainly focuses on these two species. riassunto: alberdi, m.t., palombo m.r, gli equidi stenonoide del pleistocene inferiore e medio inferiore dell’italia. (it issn 0394-3356, 2011) almeno cinque specie di equidi stenonoidi sono presenti in italia durante il pleistocene inferiore e medio inferiore: equus livenzovensis, equus stenonis, equus stehlini, equus altidens ed equidi di grande taglia generalmente riferiti al cosiddetto gruppo di “e. bressanus e. suessenbornensis”. equus altidens e equus suessenbornensis sono sicuramenti presenti in italia, almeno dal tardo villafranchiano fino al galeriano superiore, spesso associate nello stesso giacimento. questo studio è principalmente centrato sull’esame critico di queste due specie. key words: equus altidens, equus suessenbornensis, pleistocene, italy parole chiave: equus altidens, equus suessenbornensis, pleistocene, italia  1. introduction fossil representatives of the genus equus are recorded from several italian localities, dating from the early to early middle pleistocene. various species and subspecies are reported in the literature (see e.g. azzaroli, 1965, 1979,1990,1999; de giuli, 1972; alberdi et al., 1988; caloi & palombo, 1990; caloi, 1995, 1997; forsten, 1999; and references in those papers), but their taxonomy, phylogenetical relationships and chronological distribution are still a matter of debate. at least five stenonoid horses have been recorded: equus livenzovensis, equus stenonis, equus stehlini, equus altidens and large sized equids generally referred to as the so-called “equus ex gr. e. bressanus e. suessenbornensis”. equus livenzovensis was a large horse whose scanty remains were found in deposits dated to the beginning of the pleistocene (middle villafranchian, montopoli fu). equus stenonis first reported a short time later (costa san giacomo fu) is the most common equid in the early late villafranchian local faunal assemblages (lfas) (olivola, tasso fu), while the actual chronological range of the small stenonoid horse equus stehlini is uncertain, due to the controversial identification of some specimens already ascribed to e. stenonis and/or e. altidens (cf. alberdi et al. 1998; fostern 1999). advanced stenonoid equids, by some authors ascribed to equus altidens are reported in lfas of farneta fu (e.g horses from selvella, tuscany = e. cfr. stenonis in de giuli 1987; = e. stenonis ssp., in caloi & palombo, 1990; equus altidens in caloi, 1995). equus altidens and equus suessenbornensis were rather long surviving species, sometimes found together in the same lfa. their remains have been found in italy in lfas ranging in age from the latest villafranchian (pirro fu, alberdi & palombo, in press) to the late galerian. a horse possibly close to e. suessenbornensis is also reported from an early aurelian lfa by capasso barbato & gliozzi, (1995). this study mainly focuses on these two species. equus altidens reichenau, 1915 e. altidens is a slender horse, more so than in the other stenonoid species, including the most related species e. senezensis (alberdi et al. 1998). the protocone shows a variable shape, flattened or indented lingually, occasionally lacking a heel, while the distal part is more protruding than in e. stenonis. scholars are divided about the origin and 141 143 142 the phylogenetic relationship of e. altidens because of differing opinions about the actual taxonomical and phylogenitical value of some features typically shown by this species. most authors consider it a “stenonoid” horse, close to or originated from the equus stenonis lineage (cf. alberdi et al. 1998). others believe e. altidens to have been a new early pleistocene settler coming from africa (=equus numidicus, guerrero-alba & palmqvist 1997), or to be part of a “nonstenonian” widely dispersed group, which includes early to middle pleistocene slender horses, sharing some features such as short protocone, long metaconide, a not very deep lingual grove, and developed stylides (eisenmann 2004). the main morphological traits, especially those shown by teeth, support the hypothesis that e. altidens could be part of a stenonoid lineage related to e. stenonis. the subspecies e. a. granatensis has been regarded by some authors as an advanced subspecies of e. stenonis, but a revision of stenonoid horses performed by alberdi et al. (1998) demonstrated that “e. stenonis grantensis”, “e. grantensis” and specimens regarded as intermediate (equus granatensisaltidens) can be confidently ascribed to e. altidens. equus suessenbornensis wüst, 1900 e. suessenbornensis is a large and robust horse, but smaller than e. major (=e. bressanus). the teeth are morphologically close to e. altidens but the enamel of upper cheek teeth show a more complicated pattern. moreover, the teeth of e. suessenbornensis share some morphological traits with the teeth of caballine horse (e.g. a long protocone with concave lingual borders, and larger mesostyles and grooves on the premolars at least somewhere along the crown). on the molars, the styles are simple or faintly grooved. the lower cheek teeth show cingular structures as protostylids. the preflexid and postflexid are slightly folded. the phylogenetical relationship of this species have been a matter of debate. some authors consider e. suessenbornensis a descendant of e. major (grossouvre & stehlin 1912; forsten 1999). others consider it an archaic caballoid or a true horse (gromova 1949). musil (1969, 1992) rejected any affinity between e. suessenbornensis and e. stenonis, while nobis (1971). samson (1975) and azzaroli (1984) considered it close to or direct descendant of the latter. actually, e. suessenbornensis might be regarded as intermediate or convergent to the stenonoid horses (cf. alberdi et al. 1998). some features of e. suessenbornensis look like caballoid equids (gromova & dubrovo 1975) and some among the most advanced variants of the species show dental characteristics too derived for a stenonoid horse. in point of fact, the species belongs to the phyletic lineage of e. majore. suessenbornesis and likely originated from the e. livenzovensis clade, and could be regarded as a ‘stenonoid horse’. in italy, e. suessenbornensis is mainly known from early middle pleistocene lfas, albeit scanty remains have been reported from few early galerian (late early pleistocene) lfas. the time of the first appearance of the species in europe is uncertain. in italy, some cheek teeth, whose morphology and dimensions are close to those of e. suessenbornensis, were found in the 17th century near bucine (val di chiana, tuscany). as discussed by azzaroli (1984), their stratigraphical position is unclear, but the hypothesis that they might have been retrieved from sediments of early pleistocene age, widely outcropping in the area, cannot ruled out. if this is so, e. suessenbornensis might be part of the species recorded in the farneta faunal unit (late villafranchian). the presence in the late early pleistocene of equus suessenbornensis is confirmed by findings in the pirro nord karst network (alberdi & palombo, in press). 2. remarks equus altidens and equus suessenbornensis were a rather long surviving species, recorded in italy from the latest villafranchian to the galerian, sometimes found together in the same lfa. the two equids probably differentiated in ecology and the notable differences in size likely prevented any interspecies competition. for instance, e. altidens, and e. suessenbornensis were both present in lfas dating to the early plestocene (e.g. in italy in the pirro nord lfa, alberdi & palombo, in press; in spain in the fuente nueva-3, barranco león-5 and huéscar-1 lfas, alberdi, 2010) as well as to the early middle pleistocene (e.g in italy in the lfas of ponte galeria, alberdi & palombo, in press, and venosa loreto, alberdi et al., 1988, as well as in some lfas in the surroundings of verona, caloi & palombo 1991; in spain in the cúllar de baza-1 lfa, alberdi, 2010). in italy, as in spain¸ e. altidens is definitely more abundant than e. sussenbornensis, while in central europe (e.g. süssemborn, germany) both species are equally represented. the relative abundance of these species varies according to the environmental characteristics, especially the vegetation cover and productivity, of the localities in which they were found. available data suggest that, consistently with their ecological requirements, e. altidens, might have differentiated even in a rather restricted geographic region, whilst e. suessenbornensis, did not undergo any important local differentiation. alberdi m. t.& palombo m. r. 143 ms. received: testo ricevuto il references alberdi m.t. (2010) estudio de los caballos de los yacimientos de fuente nueva-3 y barranco león-5 (granada). en i. toro, b. martínez-navarro y j. agustí (eds.) "ocupaciones humanas en el pleistoceno inferior y medio de la cuenca de guadix-baza". arqueol. monog., junta de andalucía, consejería de cultura, 291-306. alberdi m.t., caloi l. & palombo m.r. (1988) the quaternary fauna of venosa: equids. bull. mus. anthrop. préhist. monaco, 31, 139. alberdi m.t., ortiz jaureguizar e. & prado j.l. (1998) a quantitative review of european stenonoid horses. j. paleont., 72, 371-387. alberdi m.t. & palombo m.r. (in press) the early pleistocene equidae from pirro nord (apricena, southern italy). palaeontographica abt a. palaeozoolstratigr. azzaroli a. (1965) the two villafranchian horses of the upper valdarno. palaeontographia italica, 57, 2134. azzaroli a. (1979) on a late pleistocene ass from tuscany, with notes on the history of asses. palaeontographia italica, 71, 27-47. azzaroli a. (1984) on some vertebrate remains of middle pleistocene age from the upper valdarno and val di chiana, tuscany. palaeontographia italica, 43, 104-115. azzaroli a. (1990) the genus equus in europe. in linsday, e.h., fahlbusch, v. & mein, p. (eds.) european neogene mammal chronology. plenum press, nato 180, 339-355, new york azzaroli a. (1999) notes on some middle and late pleistocene equids of italy. boll. soc. paleont. it., 38, 97-108. caloi l. (1995) il genere equus nell’italia centrale. in farinacci a. (ed.) biostratigrafia dell’italia centrale. studi geologici camerti. volume speciale, parte b, 469-486. caloi l. (1997) new forms of equids in western europe and palaeoenvironmental changes. geobios, 30, 267284. caloi l. & palombo m.r. (1990) osservazioni sugli equidi italiani del pleistocene medio inferiore. geologica romana, 26 (1987), 187-221. caloi l. & palombo m.r. (1991) gli equidi del pleistocene medio-inferiore di soave il castello, monte tenda e romagnano il serbaro (verona, italia). boll. mus. civ. st. nat. verona, 15 (1988), 447-468 capasso barbato l. & gliozzi e. (1995) biochronological and palaeogeographical implications of a well -balanced late middle pleistocene fauna from quisisana-certosa (capri, southern italy). boll. soc. paleont. it., 34, 235–261. de giuli c. (1972) on the type form of equus stenonis cocchi. palaeontographia italica, 68, 35-49. de giuli c. (1987) late villafranchian faunas of italy: the selvella local fauna in the southern chiana valley umbria. palaeontographia italica, 74, 11-50. eisenmann v. (2004) les equidés (mammalia, perissodactyla) de saint-vallier (drôme, france) et les equidés plio-pleistocènes d'europe. geobios, 37, 279-305 forsten a. (1999) a review of equus stenonis cocchi (perissodactyla, equidae) and related forms. quaternary science reviews., 18, 1373-1408. gromova v.i. & dubrovo i.a. (1975) fossile pferde aus dem faunenkomplex von tiraspol. quartärpaläontologie, 1, 107-124. gromova v.i. (1949) istorija loshadej (roda equus) v starom svete. chast' 1. obzor i opisanie form. trudy paleontologicheskogo instituta, 17, 1-373 (en russe). grossouvre a. de & stehlin h.g. (1912) les sables de rosières, près saint-florent (cher). bull. soc. geol. france, 4, 194-212. guerrero-alba s. & palmqvist p. (1997) – estudio morfométrico del caballo de venta micena (orce, granada) y su comparación con los équidos modernos y del plio-pleistoceno en el viejo y nuevo mundo. paleontologia i evolucion, 30-31, 93-148. musil r. (1969) – die equiden-reste aus dem pleistozän von süssenborn bei weimar. paläontolog. abh., 3, 617-666. musil r. (1992) die pferde aus der oberpliozanen spaltenfallung schemfeld bei eichstgtt. mitteil. bayeris. staatssam. paläont. u. histor. geol., 32, 115-162. nobis g. (1971) vom wilsdpferd zum hauspferd. böhlau verlag köln wien, 96. samson p. (1975) les equides fossiles de roumanie. geologica romana, 14, 165-352 the early to early middle pleistocene stenonoid horses ... january 15, 2011 15 gennaio 2011 impaginato amato robustelli tthhee nnoocceellllaa ccoonngglloommeerraatteess:: aa pprroobblleemmaattiicc oouuttccrroopp hhiigghhllyy ssuussppeennddeedd oonn tthhee ssoouutthheerrnn ssllooppee ooff tthhee eeaasstteerrnn ssoorrrreennttoo ppeenniinnssuullaa ((iittaallyy)) aa.. aammaattoo11 && gg.. rroobbuusstteellllii22 1 dip. to di scienze della terra, università degli studi di napoli “federico ii”; amatoa@unina.it 2 dip. to di scienze della terra, università degli studi della calabria; robustelli@unical.it abstract a 130m thick sedimentary alluvial to slope deposits (nocella formation) rests on a concave up spur suspended between 660m and 800m on the southern coastal slope of the sorrento peninsula have been analized. stratified slope waste deposits (nocella breccias) unconformably and abruptly rest on nocella alluvial deposits (nocella conglomerates). facies analysis of the nocella conglomerates indicate a high-energy, gravel bed braided environment. in particular two facies association have been distinguished. the first one is representative of in-channel deposition and both vertical accretion and lateral and downstream migration of gravel bars. the second one reflect vertical accretion and downstream migration of low-relief gravel bars and extensive, locally in-channel, deposition by highenergy flood flows respectively. paleocurrent data indicate a wnw-sloping paleoslope away from a, nowadays, lacking highland. techniques of lateral profile analysis and hierarchical ordering of bounding surfaces has also been applied to the nocella conglomerates, and allows two different river model to be outlined. slope deposits also taper upslope coating a triangular facet belonging to the first fault scarp generation which occurred after the formation of the i order palaeosurface sailed by nocella conglomerates; they are cut by the second fault scarp generation together with relics of the ii order palaeosurface such as the agerola karst basin and the s.maria del castello erosional surface. we correlate the nocella alluvial deposits with the s. maria del castello relic of ii order palaeosurface and thus we propose a reconstruction of a part of the sorrento peninsula early pleistocene landscape. the source area of the nocella conglomerates should be a mountainous area located east-southeastward of nocella site and should be the same as, on the opposite side, fed the clastic infilling of the agerola karstic basin. riassunto sul versante meridionale della penisola sorrentina, in corrispondenza di uno sperone sospeso tra 660m e 800m s.l.m., affiora una successione sedimentaria spessa circa 130 m costituita da depositi alluvionali su cui poggiano depositi di versante. i depositi di versante (brecce di nocella) giacciono in discordanza sui depositi alluvionali (conglomerati di nocella). l’analisi di facies sulla porzione alluvionale della successione è indicativa di un ambiente fluviale ad alta energia di tipo braided. in particolare sono state distinte due associazioni di facies la cui differenza principale risiede nella maggiore o minore presenza di unità canalizzate, oltre alle loro geometrie, e nei caratteri geometrici delle forme migranti (barre). la direzione misurata delle paleocorrenti, che è wnw, evidenzia un chiara discordanza oroidrografica, in quanto l’attuale paesaggio manca completamente dei rilievi alimentatori. nell’ambito delle porzione alluvionale della successione affiorante sono state applicate tecniche di analisi laterale dei depositi e di ordine gerarchico delle superfici che limitano i principali elementi architettonici individuati al fine di caratterizzare la tipologia di modello fluviale. i depositi di versante mantellano versanti a faccette triangolari derivanti dal modellamento della scarpata di faglia di prima generazione che ha smembrato e dislocato il i ordine di paleosuperfici ed è stata fossilizzata dai conglomerati di nocella. essi sono dislocati da una ulteriore fase tettonica insieme ai relitti del ii ordine di paleosuperfici, correlabili con quelli che bordano la conca carsica di agerola e con la paleosuperficie di santa maria del castello. considerazioni di carattere morfostratigrafico ci hanno consentito di correlare i conglomerati di nocella con il relitto di ii ordine di peleosuperfici di santa maria del castello, e pertanto proponiamo una ricostruzione del paleopaesaggio che caratterizzava questo settore della penisola sorrentina durante il pleistocene inferiore. tale paleopaesaggio, che prevede la presenza di una area montuosa sorgente dei conglomerati di nocella a ese della successione analizzata, probabilmente fungeva da area sorgente anche per i depositi che costituiscono il riempimento clastico della conca di agerola. keywords: palaeosurfaces, fluvial deposits, facies analysis, sorrento peninsula, early pleistocene. parole chiave: paleosuperfici, depositi fluviali, analisi di facies, penisola sorrentina, pleistocene inferiore. il quaternario italian journal of quaternary sciences 1155(1), 2002, 83-96 11.. iinnttrroodduuccttiioonn the sorrento peninsula is an ene-wsw trending morphostructural high interposed between the perytyrrhenian depressions (grabens) of the gulf of naples-campana plain to the north, and the gulf of salerno-sele plain to the south (fig.1). it consists mainly of a mesozoic carbonate units (the picentini mts.-mt. taburno tectonic unit; bonardi et al., 1988) and of a miocene terrigenous synorogenic units. due to its position (it is one of the westernmost outcropping part of the southern apennines chain) together with the conservativity of its lithologic units, the sorrento peninsula represents important evidence of the early phases of post orogenic morphostructural evolution of the southern apennine chain (cinque et al., 1993). as regards the structural setting of the sorrento peninsula, it represents a nw dipping monocline which is dislocated into minor blocks by two systems of high angle fault trending nw-se and ne-sw. in particular the anti-apenninic system is responsible for formation of the grabens of napoli and salerno (bartole et al., 1984; sacchi et al., 1994); an e-trending system fault has contributed to the development of the first one too. previous authors distinguished up to five block-faulting phases during plio-pleistocene time on the basis of structural data (torrente et al., 1999). by a morphostructural point of view, there are three main deformation phases 84 a. amato g. robustelli f ig . 1 g eo lo gi ca l s ke tc h m ap o f t he s or re nt o p en in su la ( fr om c ai az zo e t a l., 2 00 0, m od ifi ed ). t he fr am ed a re a co rr es po nd s to th e on e re po rt ed in f ig . 2 . s ch em a g eo lo gi co d el la p en is ol a s or re nt in a (d a c ai az zo e t a l., 2 00 0, m od ifi ca to ). l ’a re a ne l r iq ua dr o co rr is po nd e a qu el la r ap pr es en ta ta in f ig . 2 . (caiazzo et al., 2000), which occurred during the early pliocene-late middle pleistocene time interval, in response to the eastward migration of the thyrrenian extensive domain (sartori, 1989, 1990). the presence of raised marine terraces indicates the uplift of the sorrento peninsula from the lower pleistocene to the middle pleistocene, during which the width of the peninsula was progressively reduced by block faulting that affected the southern flank enlarging the contiguous gulf of salerno (cinque, 1986). the emerged marine terraces along the southern slope of the sorrento peninsula allow cinque & romano (1990) to infer that the latest phases of block faulting occurred during the late middle pleistocene and that sorrento peninsula stopped rising no later than the last interglacial. on the contrary, the nearby campana-plain graben has continued to subside during the upper pleistocene to present time (milia, 1996). since no absolute chronological constraints have ever been reported, the different stages in which the morphostructural evolution of the sorrento peninsula have been divided are only relatively dated. the beginning of the geomorphologic history of the sorrento peninsula is as old as the formation of the i order palaeosurface, suspended up to 1300 m a.s.l. on the top of mt. faito (fig. 2), which has been ascribed to a probably early – middle pliocene time (caiazzo et al., 2000). the oldest geomorphological elements are few hanging relics remnants of mature erosion landscape (i order palaeosurface). after a phase of block faulting that disrupted and uplifted the i order palaeosurface, a new base-level established some hundreds of meters below. in this paper we attempt to reconstruct the landscape of this geomorphological stage, now broken and suspended up to 850 m a.s.l., by considering different types of evidences preserved in the studied area and by analysing the stratigraphic and sedimentological characteristics of the here informally named nocella formation. 22.. ggeeoommoorrpphhoollooggyy the sorrento peninsula is characterised by a clear structurally controlled landscape, as it is dominated by the occurrence of fault scarps and structural cliffs and valleys (figg. 1, 2). moreover, due to the vicinity of the sea, the area experienced a great number of eustatic controlled fluvial dissectional cycles, which actively contributed to reduce or even cancel the erosional landforms modelled during the pauses of the tectonic activity. nonetheless, clear traces of ancient erosional cycles occur and we attempt to interpret them in terms of palaeoenvironment and relative age. in the geomorphological map of fig. 2, the main structural, erosional, and depositional landforms of the eastern sorrento peninsula are reported, and the relative inferred ages are also proposed (see section 4 for discussion). two sectors have been distinguished: the eastern one, which is dominated by the high homoclinal calcareous block of mt. faito, and the western one, which is sensibly lower. the two sectors are separated by the fault scarp of mt. faito which transversally crosses the peninsula. on both the sectors we recognise relics of palaeosurfaces testifying the occurrence of past phases 85the nocella conglomerates ... of relief smoothing under the control of both local and general baselevels of erosion. most of the relics cut across dipping strata, but in some cases they rest on almost horizontal strata. in few cases (e.g., faito, agerola) they are associated to outcrops of undated continental conglomerate. more frequently, these surfaces lack any type of deposits, so that their chronology is uncertain. the only ancient (early pleistocene?) clastic deposits are the nocella alluvial deposits (see section 3) suspended between 700 and 775 m a.s.l., on a policyclic slope. more precisely, these deposits are cut by the free face of a coastal fault scarp whose slope is about 35%. above this free face the slope changes in about 25% and appears concave up to the summit where the top surface of mt. faito occurs. this change in slope gradient is due to a different lenght of the erosional processes which caused the decline and the slope replacement of the relative fault scarp planes. the more ancient erosional cycle is well represented by the highest relics of palaeosurface occurring on the eastern uplifted block, indicated on the map of fig. 2 as the i order palaeosurface. the relics of the i order palaeosurface are almost reduced to flat watershed, but locally (see the top of ridge that limits the agerola plain to the east) they include also wind gaps clearly unlinked to the modern valley network. as mentioned before, on the top of mt. faito these surfaces are associated with the outcrop of severely eroded clastic deposits, interpreted as slope and fan breccias, produced when the base level was very near to those of the i order palaosurface landscape. the mt faito palaeosurface could be upper pliocene in age, since it is younger than the miocene n-verging thrustsand older of the phase of normal block –faulting (probably late pliocene – early pleistocene (aucelli et al., 1996). the slope fault scarp of the sorrento peninsula can be divided in two main groups: a first characterized by concave up profiles with mean gradients of about 25 – 30 % , standing on the highest portions of reliefs, locally just behind the relics of the i order palaeosurface; the other ones is represented by the lower tracts of slopes, characterized by higher gradients (in the order of 40 % and more), convex profiles frequently disrupted by parallel fault planes. these two different types of slope profile are locally separated by relics of the ii order palaeosurface, that occur on both the eastern and the western sector. it is probable that part of the ii order relics, as well as some lower erosional terraces must be interpreted as downfaulted portions of the i order palaeosurface that were simply remoulded during the pause of the tectonic activity that allow the ii order palaosurface to be formed. different examples of this type are widespread on the western downfaulted sector of the study area. we will describe two cases: the surface of the agerola karst basin, and the s.maria del castello surface. the agerola graben was formed by the tectonic phase that disrupted the i order palaeosurface by the normal activity of the n-s trending faults on which the western slope of the sproviere murillo ridge and the eastern slope of mt. tre calli ridge are sculptured. the top surface of the graben can be considered a ii order surface, it is a policyclic surface suspended at about 86 a. amato g. robustelli f ig . 2 g eo m or ph ol og ic al s ch em e of t he s ou th e as te rn s or re nt o p en in su la : 1) v al le y do w nc ut tin g; 2 ) ha ng in g va lle ys a nd w in g ga ps ; 3) s tr uc tu ra l s lo pe ; 4) m id dl e p le is to ce ne f au lt sc ar p; 5 ) e ar ly p le is to ce ne fa ul t s ca rp ; 6 ) m id dl e – u pp er p le is to ce ne 3 rd o rd er p al ae os ur fa ce ; 7 ) e ar ly p le is to ce ne 2 nd or de r pa la eo su rf ac e; 8 ) e ar ly p lio ce ne 1 st or de r pa la eo su rf ac e. s ch em a ge om or fo lo gi co d el s et to re s ud – o rie nt al e de lla p en is ol a s or re nt in a. 1 ) in ci si on i v al liv e; 2 ) va lli s os pe se e v al li re lit te ; 3 ) ve rs an te s tr ut tu ra le ; 4 ) sc ar pa ta d i f ag lia m ed io p le is to ce ni ca ; 5) s ca rp at a di f ag lia i nf ra pl ei st oc en ic a; 6 ) pa le os up er fic ie d i 3° o rd in e (p le is to ce ne m ed io – s up er io re ); 7 ) pa le os up er fic ie d i 2° o rd in e (p le is to ce ne i nf er io re ); p al eo su pe rf ic ie d i 1° o rd in e (p lio ce ne in fe rio re ). 87the nocella conglomerates ... 650 m a.s.l. the graben infilling outcrop of few tens of meters in river incision and consists of a polygenic angular conglomerate composed of carbonatic and subordinate terrigenous clasts, the latter derived from a miocene terrigenous unit outcropping during early pleistocene time and then tectonically drowned under the sea of the salerno gulf. due to the bad exposition, a more precise facies interpretation and source direction are not available for these deposits, except for those outcropping along the rim of the graben, which are at the top of the clastic infilling body and can be interpreted as slope breccias deposits. we don’t have enough elements to establish if the endoreic conditions date back to the birth of the graben or if they developed after, but surely they had a long duration as demonstrated by signs of remarkable karstic planation along the borders of the basin, suspended at about 630 and 570 m a.s.l.. the epikarstic activity was interrupted by the tectonic phase that downfaulted the southern rim of the agerola intramontane endoreic basin and promoted its capture by the retrogressive deepening of the schiato stream gorge. the s. maria del castello surface is located on the western sector, it is an erosional landsurface suspended upon positano town at about 650 m a.s.l. with the shape of a low gradient wide valley tract nw dipping. it is truncated by a fault scarp ne-sw oriented and dipping to the north, whose characteristics are those typical of the second, more recent type of slopes. toward the ne the s. maria del castello ii order surface confine with the base of the punta medico slope, which is one of the triangular relics of the first type fault scarps formed by slope replacement and then deeply dissected. near s. maria del castello, entrenched within the ii order palaeosurface are other terraced alluvial fan conglomerates, suspended between 500 and 550 m a.s.l. (moiano conglomerates). similar deposits occur near pimonte, on the northeastern side of mt. faito. both moiano and pimonte conglomerates are suspended and hence older than the other dissected alluvial fan occurring at lower elevations and located in the lower tracts of the valleys. these younger alluvial fans are middle and late pleistocene in age. similarly, the traces of marine terraces suspended between 6-8 m and 50 m a.s.l. on the southern coast are late pleistocene to middle pleistocene in age (cinque & romano, 1990). on the basis of the existing knowledge, the moiano and pimonte conglomerates can be referred to a generic middle pleistocene. 33.. nnoocceellllaa ffoorrmmaattiioonn the nocella formation. lies with pronounced angular unconformity upon jurassic dolomitic limestones, which constitute the bulk of the relief. the best exposed stratigraphic section , about 130m thick, outcrops on a hanging, concave up spur ranging between 660m and 800m in elevation (fig. 3). here stratified slope waste deposits (nocella breccias) rest unconformably on nocella alluvial deposits (nocella conglomerates) proofing that their deposition occurred soon after the alluvial one. slope deposits tend to taper upslope coating a triangular facet which is one of the triangular relics of the scrajo-vettica fault scarp on fig. 3 overview photograph of the studied section. the location of the logs are marked and numbered. the nocella formation, resting uncomformably above jurassic limestones, consists of alluvial deposits (nocella conglomerates) overlaid by slope breccias (nocella breccias). the northern segment of the scrajo-vettica fault is also marked. panoramica dell’area studiata. s1 ed s2 indicano le sezioni esaminate. la formazione di nocella, discordante sui calcari giurassici, è costituita da una porzione inferiore alluvionale (conglomerati di nocella) passanti verso l’alto a brecce di versante (brecce di nocella). in figura è inoltre segnalata la traccia del segmento settentrionale della faglia scrajo-vettica. 88 a. amato g. robustelli which the south-eastern slope of the mt. tre calli ridge are sculptured by slope replacement processes coupled with consequent river dissection. the basal angular unconformity represent an asymmetric paleovalley into which nocella conglomerates were deposited and, in particular, sail the north-eastern segment of the scrajovettica fault zone. steep and high scarp perimeters the spur at issue which reflects the re-activation of the the scrajo – vettica fault zone and its dissection by consequent incisions characterised by steep flanked v-shaped valleys having high longitudinal gradients. their longitudinal cross-profile is characterized by upper reach steeper than the slope they dissect. the nocella conglomerates, about 90m thick, has been chosen as a type section for detailed description of the sedimentary facies. as the vertical cliff which confines the spur does not allow a complete sedimentary log to be given, only the middle and the upper portion of the nocella conglomerates have been analysed in detail (fig. 3); they outcrop on the north-western and southeastern part of the spur respectively. minor exposures of clastic deposits belonging to the same morphoevolutive stage occur close to hanging, concave-up footslope of the scrajo-vettica fault zone. the nocella type section consists of a crudely cu sequence characterized by the dominance of conglomerate lithofacies (>95%) with very subordinate sandstone lithofacies. fine grained lithofacies were not observed. conglomerate lithofacies are clast supported, poorly to moderately sorted, and contain angular to subrounded clasts. clast size is generally in the pebble to cobble range although boulders up to 30 cm occur in the topmost part of the sequence. the lithology does not vary over the study area; dominant clasts include white to greyish dolomitic limestone mainly of jurassic age (coming from the jurassic part of the local mesozoic succession). rare clasts of miocene flysch deposits also occur, suggesting that miocene terrigenous deposits outcropped in the source area of nocella conglomerates. 33..11 lliitthhooffaacciieess ddeessccrriippttiioonn the nocella conglomerates is characterized by six sedimentary facies distinguished on the basis of sedimentary structures and bed geometry. paleocurrent data indicate wnw-ward paleoflows close parallel to the scrajo-vettica fault zone. two sedimentary logs are given in fig. 4; they are representative of the middle and the upper part of the nocella conglomerates and are located respectively along the nw and se side of the spur (figg. 3 and 4). table 1 summarizes the lithofacies codes used in describing nocella conglomerates, based on the fluvial lithofacies code modified from miall (1996). lliitthhooffaacciieess ggccmm –– ssttrruuccttuurreelleessss,, ccllaasstt--ssuuppppoorrtteedd ccoonn-gglloommeerraattee this facies consists of pebble to cobble-size clasts subangular in shape; they are moderately to poorly sorted and display a clast-supported texture (fig. 5). matrix content is generally less than 20% and consists of coarse sand and granules. conglomerate fabric is disorganized, although it appears locally to be a preferred clast orientation. the longest a-axes of some elongate clasts are parallel to paleoflow directions; locally a(p)a(i) fabric fig. 4 logs of the nocella conglomerates along the northwestern (s1 in fig. 2) and south-eastern (s2 in fig. 2) side of the nocella spur (fig. 2). letters refer to lithofacies and arrows indicate paleocurrent. the paleocurrent rose refers to the total number of measurements. sezioni stratigrafico-sedimentologiche dei conglomerati di nocella sul lato nord-occidentale (s1 in fig. 2) e sud-orientale (s2 in fig. 2) dello sperone visibile in fig. 2. le sigle si riferiscono alle litofacies mentre le frecce indicano la direzione delle paleocorrenti. il diagramma si riferisce al totale delle misure effettuate. mode occur. grading is absent or basal inverse grading and crudely normal grading locally occur. the conglomerates consist of lenticular or laterally apparently continuous, non erosive-based units whose thickness range between 10 to 45cm. this lithofacies occurs mostly in the upper part of nocella conglomerates and is interbedded with gci and gh lithofacies lliitthhooffaacciieess ggccii –– iinnvveerrsseellyy ggrraaddeedd,, ccllaasstt--ssuuppppoorrtteedd ccoonn-gglloommeerraattee this facies consists of pebble-size clast, although cobbles up to 20 cm locally occur. the clasts are angular to subrounded; they are moderately sorted and characterised by a clast-supported texture, with a coarse sand matrix locally absent. inverse grading is well developed and a(t)b(i) fabric mode is locally present. beds of this facies have sharp non erosional lower contacts and occur in lenticular units that are up to 30 cm thick and up to 8m wide; locally such lenticular beds show a convex-top boundary. as for gcm facies, this lithofacies has been well recognized in the upper part of nocella conglomerates. lliitthhooffaacciieess gghh –– hhoorriizzoonnttaallllyy ssttrraattiiffiieedd ccllaasstt--ssuuppppoorrtteedd ccoonngglloommeerraattee pebble to fine cobble-size clasts in this facies are subangular to subrounded; they are moderately to well sorted with a clast-supported texture (fig. 5). well developed bedding and horizontal stratification is ubiquitous; 89the nocella conglomerates ... pebble-size clasts show a local well developed a(t)b(i) fabric mode. imbrication and cluster bedforms indicate paleoflow directions toward wnw. conglomerate beds are usually normal graded (fig. 5); medium to coarse sand matrix is usually present but open framework conglomerate beds also occur (fig. 5). local beds exhibit bimodality both (fig. 5) in the lower and in the upper band of each bed textural inversion of nemec & steel (1984) and steel & thompson (1983). these conglomerates occur in laterally continuous beds that can be traced for at least 20m; basal contacts are usually sharp and planar, but local scour surfaces may be observed. these sheet-like units, tipically few dm thick (up to 40cm), set up multistory units up to about 4m thick. this lithofacies is interbedded with gcm and gci lithofacies, but is well developed also in the middle part of the nocella conglomerates. lliitthhooffaacciieess ggpp –– ppllaannaarr ccrroossss--bbeeddddeedd ccllaasstt--ssuuppppoorrtteedd ccoonngglloommeerraattee this facies consists of subangular to subrounded pebbles. the clasts are moderately to well sorted and characterised by a clast-supported texture. well developed planar cross-stratification occurs; the foreset beds, up to 15cm thick, consist of alternating fine and coarse pebbles without any signs of rhythmic organization. dip azimuth of the foreset beds is toward sse; dip angle range from few degrees up to 13°. foreset beds appear to be ungraded. sandy matrix is scarce but usually present; some local foreset beds have an open framework. these conglomerates occur in laterally continuous tabular units, ranging from 50 to 110cm in thickness, with internal scour surfaces. basal contacts are sharp and non erosive; top contact shows a local convex-up boundary (fig.6). this lithofacies occurs in the middle part of the nocelle conglomerates and grade laterally into gh lithofacies. lliitthhooffaacciieess ggtt aanndd ggtt11 –– ttrroouugghh ccrroossss--ssttrraattiiffiieedd ccoonngglloo-mmeerraattee trough cross-stratified conglomerate occur as single sets ranging from 0.6m to 1,5m deep and from 1,2m to 7.4m in width. basal scours affect both the conglomerate facies and sandy ones; channel margins are gentler in slope with increasing channel width the bigger ones occur in the middle part of the nocella conglomerates (fig. 7a). this facies is developed in pebble size clasts, subangular to subrounded; they are moderately to well sorted with a clast-supported texture. fig. 5 set of clast-supported conglomerates with disorganized fabric (gcm facies) overlay normal graded, horizontally stratified conglomerates (facies gh). note also the poor degree of rounding of the clasts. paleoflow is obliquely into the face and to the left. strati di conglomerati massivi, clasto-sostenuti (facies gcm) ricoprono conglomerati stratificati organizzati in unità normalmente gradate (facies gh). si può notare lo scarso grado di arrotondamento dei clasti. i paleoflussi sono obliqui e diretti verso sinistra. facies facies sedimentary intepretation code structures gcm massive, clast none or weak pseudoplastic cohesionless supported gravel grading debris flow or high sedimentconcentration flood flows gci clast-supported inverse grading, clast-rich debris flow or gravel locally imbrication hyperconcentrated flood-flows; filling of broad, sheet-like channels gh clast-supported, horizontal bedding, accreditionary units longitudinal well bedded gravel imbrication bars gt gravel, stratified trough cross-beds minor channel fills gt1 gravel, stratified low-angle and/or rapid scour fills by highhorizontal bedding concentration flood-flows gp gravel, stratified planar cross-beds transverse accretion units of bars sh coarse sand, many crude horizontal deposition from heavily be pebbly lamination, locally sediment-laden flows during massive waning floods above bars table 1 description and interpretation of sedimentary facies adapted from bridge (1993) and miall (1996) trough fill consists of non rhythmic alternating fining upward and ungraded low angle sets (gt lithofacies fig.7a); their thickness is up to 15cm and they dip of about 10°. locally lag deposits of coarser grain size (up to fine boulders) grading upward into gci lithofacies occur above a bowl-shaped, erosional bases of trough sets (gt1 lithofacies; fig. 7b). through fill consists also of stacked sets of gh lithofacies. just once (fig. 7c) well developed foreset beds dipping north-westward was observed overlying gt1 lithofacies; these beds may be considered as gp lithofacies and grade upward into gh lithofacies. lliitthhooffaacciieess sshh –– hhoorriizzoonnttaallllyy ssttrraattiiffiieedd ssaannddssttoonnee this lithofacies consists of sand to granule size clasts, with a local occurrence of isolated out-sized clasts (a-axes>5cm). it is organized in lenses and/or wedge-shaped units locally up to 15cm thick and over 7m extended. locally they show crude horizontal stratification. massive texture was also observed. sandy facies usually rest on gh lithofacies. 33..22 ffaacciieess aassssoocciiaattiioonnss iinntteerrpprreettaattiioonn lateral and vertical facies associations, paleocurrent and coarse-grained texture suggest that the nocella conglomerates was deposited in a high velocity stream. on the basis of comparisons with the degree of rounding shown by other pleistocene alluvial units of the 90 a. amato g. robustelli fig. 6 middle part of the nocella conglomerates: one largescale sets of planar cross-stratified conglomerates (gp facies) overlain and underlain by horizontally stratified conglomerates (gh facies). porzione intermedia dei conglomerati di nocella: si nota un intervallo a stratificazione incrociata-planare (facies gp) intercalato in conglomerati a stratificazione orizzontale (facies gh). fig. 7 trough cross-stratified conglomerates: a – example of large-scale gt facies cut into gh ones near the middle of the nocella conglomerates. b – oblique view of trough cross-stratified conglomerates (gt1 facies), underlying horizontally stratified conglomerates (gh facies). c – oblique view of trough cross-stratified conglomerates (gt1 facies), showing coarse lag above scour surface; trough fill consists of alternating fine and coarse pebble foresets (gp facies) characterized by a decrease of dip angle with a gradual transition into gh facies. .conglomerati organizzati in unità canalizzate: a – esempio di unità canalizzata (facies gt) che incide conglomerati a stratificazione orizzontale (facies gh) nella porzione intermedia dei conglomerati di nocella. b – vista obliqua di conglomerati organizzati in unità canalizzate (facies gt1), cui seguono in successione conglomerati a stratificazione orizzontale (facies gh). c – vista oblique di conglomerati organizzati in unità canalizzate (facies gt1), in cui si osservano i depositi residuali basali poggianti sulla superficie di erosione; il riempimento è costituito da un’alternanza di ghiaie fini e grossolane a stratificazione incrociata-planare (facies gp) e di cui gli strati sono caratterizzati da una riduzione della pendenza e da un graduale passaggio alla facies gh. area, we can estimate that the river reach upstream of nocella outcrop, i.e. the feeding stream, was at least a 2-3 kilometres long. two facies associations have been distinguished, and their depositional systems have been reconstructed accordingly as follows: ffaacciieess aassssoocciiaattiioonn 11 is restricted to the middle portion of the nocella conglomerates. horizontally stratified conglomerates (gh lithofacies) is the most common facies typically forming sheet-l ike units. subordinate lithofacies are represented by planar crossstratified conglomerates (gp lithofacies). minor lithofacies consist of trough cross-stratified conglomerates (gt lithofacies) and horizontally stratified sandstones (sh lithofacies). contacts between gh and gp lithofacies are usually sharp and flat, but locally they are slightly scoured. these conglomeratic lithofacies occur in laterally continuous tabular beds that can be traced for several meters. the dominance of horizontally stratified conglomerates with local internal scour indicates that high-energy tractional processes were involved, as the coarse-grained texture and the absence of fines also suggest. in particular, the dominance of tabular conglomerate sheets indicates that deposition was laterally extensive; although the occurrence of broad and shallow channels is shown by internal erosive surfaces. as a whole this facies is interpreted as being formed by deposition and migration of bars in a highenergy gravel-bed river (miall, 1977; rust, 1978; collinson, 1986; miall,1996). evidence for stream flow processes includes also clast-supported framework, a(t)b(i) fabric mode and lenticular trough cross-stratified conglomerates, the latter occur as minor lithofacies. the channellike bedforms consist of few local scours over 1m deep and 5m wide. the cross-cut relationship with gh lithofacies suggest that trough-cross stratified conglomerates may be representative of channels cutting across bars top and/or front during falling water, followed by gradual infilling of the scours. the southern tip of the western measured section represent the one and only place at which the continuity of exposure allows us to attempt a hierarchical classification of the depositional units and bounding surfaces. however, even there the impossibility to look frontally at the whole exposure prevents us from getting reliable results. nevertheless, it is noteworthy that horizontally stratified conglomerate grade laterally into gently inclined gp lithofacies (fig. 8; tab. 2), which can be interpreted as lateral accretion of gravel sheets on inclined surfaces, indicating a margin of a macroform (tab.2; element la sensu miall, 1985; 1988). the overlying and underlying horizontally stratified conglomerate have been interpreted as indicative of element gb of miall (1985, 1988). therefore the presence of element gb (tab.2) and the occurrence of locally interbedded element la (tab.2) may be interpreted, according to miall (1996), as representative of a shallow to relatively deep, gravel-bed braided river. an architectural model of this type of river may be considered the model 3 of miall (1985) ffaacciieess aassssoocciiaattiioonn 22 is restricted to the upper portion of the nocella conglomerates. the most common facies is the horizontally stratified conglomerates (gh), typically forming sheet-like units. subordinate lithofacies 91the nocella conglomerates ... fig. 8 – oblique view (a) and interpretation of the photograph (b). for element and facies codes see tables 1 and 2. circled numbers refer to the order of bounding surface. circled letters are architectural elements. for element and facies codes see tables 1 and 2. vista obliqua (a) ed interpretazione (b) di una porzione della sezione s1. per le sigle delle facies e degli elementi architettonici vedi le tabelle 1 e 2. i numeri si riferiscono all’ordine gerarchico delle superfici che limitano gli elementi architettonici (lettere cerchiate). le sigle delle facies e degli elementi architettonici sono indicate rispettivamente in tabella 1 and 2. are represented by massive conglomerates (gcm lithofacies) and inversely graded conglomerates (gci lithocacies). minor lithofacies consist of trough cross-stratified conglomerates (gt and gt1 lithofacies) and horizzontally stratified sandstones (sh lithofacies). gp lithofacies was not observed. this association is characterized by stackedsheets of graded and massive clast-supported conglomerates. the sheet-like beds range from few centimeters up to 50 cm in thickness and can be traced over a distance of several meters (see fig. 3, upper part of nocella conglomerates). the bases of the conglomerate sheet.-like bedforms are sharp and flat, but scour surfaces occur so lenticular units may be recognized. as for the facies association 1, the dominance of horizontally stratified conglomerates suggests that high-energy traction-current processes were the main depositional processes. therefore this facies is interpreted as being formed by migration of shallow and broad braided channels with abundant low-relief bars in high-energy gravelbed river. the lack of evidence of planar cross-beds (gp lithofacies), whose origin requires deep-water channel (bluck, 1979; steel & thompson, 1983; kraus, 1984), provides evidence of the shallow depth of the paleochannels. clast-supported framework, a(t)b(i) fabric mode and cluster bedforms are further evidences for stream flow processes. the massive (gcm) and inversely graded (gci) lithofacies suggest that depositional events were occasionally of very high energy; in particular, according to shultz (1984) gcm and gci lithofacies can be considered as depositional evidences of pseudoplastic debris flow and clast-rich debris flow respectively; as also suggested by lowe (1982), gloppen & steel (1981) and nemec & steel (1984), or representative of very high sediment-concentration dispersions (dilution of debris flows) such as hyperconcentrated flood-flows (pierson, 1980; pierson & scott, 1985; ridgway & decelles, 1993; scott, 1988; smith, 1986; smith & lowe, 1991; waresback & turbeville, 1990). todd (1989) suggests a stream driven origin (high-density gravelly traction carpets) for the gcm and gci lithofacies; in particular gci lithofacies is representative of granular flows in which during motion a dispersive pressure dominates (lowe, 1982; sohn et al., 1999; todd, 1989). the massive, structureless conglomerates represent the deposits of cohesionless debris-flow (smith & lowe, 1991; sohn et al., 1999) dominated by frictional grain interactions in which clast collision is hampered resulting in the lack of inverse grading and clast imbrication. the lenticular trough cross-stratified conglomerates consist of few local bowl-like channels less than 1m deep and 5m wide. the local infillings consists of inchannel deposition by high-magnitude flood-flows (gt1 lithofacies, figg.7b and 7c; hein & walker, 1977; miall, 1977; nemec & postma, 1993; jo & chough, 2001); in particular gp lithofacies (fig. 7c) may be interpreted as cross-bedded conglomerates developing where channels debouche into pools (ramos & sopena, 1983). as a whole we may interpret the laterally extensive conglomerate sheets as elements gb (sensu miall, 1985; 1988; tab. 2) in which high energy flood-flow deposits (gcm and gci lithofacies) are subordinate and representative of broad, low-relief channel fill. element gb consists of three types of gravel tractions-current deposits; gh lithofacies predominates, whereas tha gt and gt1 ones are very subordinate. the interbedded lenses of horizontally stratified sandstones (sh lithofacies) may represent remnants of element sb due to rapid deposition from heavily sediment-laden flows 92 a. amato g. robustelli element and symbol horizontally stratified sets (gb) large-sca le , planar crossstratif ied set (la) channel (ch) s m a l l s c a l e scour fill (ch1) principal facies assemblage gh, gcm and gci interbedded gp, gh any conbination gt, gt1, gp and gh bounding surfaces bound by erosively and accretionary fourth-order surfaces, planar to convex-up bound by fourthorder surfaces and internal third -order surfaces between accretion elements bound with concave-up, f i f thorder surfaces provide palaeocurrent of downstream accretion directions. associated with concave-up, fourthorder surfaces description stacked sets of horizontally stratified conglomerates; individual sets, decimeters thick and meters (up to 20 m) in lateral extent, parallel strata. solitary set of planar crossstratified conglomerates dipping about perpendicular to paleocurrent direction; decimeters thick and meters in lateral extent. lenticular unit with concaveup, erosional base; up to 5m thick and tens of meters wide. lenticular unit with concaveup, erosional base; solitary unit, decimeters to 1,2m thick and meters wide. interpretation vertical aggradation and downstream migration of broad, lowrelief bars. fil l ing of broad, sheet-like channels by deposition from highly concentrated flows lateral accretion of bars with internal re-activation surfaces filling of major channels filling of minor channels and scours on bars table 2 description and interpretation of architectural elements adapted from miall (1985, 1988, 1996) and bridge (1993) 93the nocella conglomerates ... during waning flood (todd, 1989; maizels, 1993; jo & chough, 2001). this kind of facies architecture, according to miall (1996), is consistent with a shallow, gravel-bed braided river interpretation. the architectural model of this type of river could be the model 2 of miall (1985). 44.. ddiissccuussssiioonn the sedimentologic and geomorphologic data reported above allows us to propose a new and more complete interpretation of the highly hanging clastic deposits outcropping near to nocella village, previously interpreted as slope replacement breccia by brancaccio et al. (1979) and cinque (1986). the detailed facies analyses of the nocella conglomerates have documented an high-energy, gravel-bed fluvial setting with a wnw-sloping paleoslope, the latter suggested by paleocurrent data. facies association 1, although characterized by a dominance of horizontally stratified conglomerates (gh lithofacies), consists also of laterally extended sets of planar cross-stratified conglomerates (gp lithofacies) that grade laterally into the gh one (lateral accretion of gravel bars on inclined surfaces; element la sensu miall, 1985; 1988). facies association 2 is characterized by gh lithofacies with subordinate gcm and gci ones, and a lack of planar cross-stratified conglomerates. the dominance of laterally extensive gravelly sheets coupled with the absence of gp lithofacies suggests that flow depths were more shallow than ones suggested by facies association 1. on the basis of comparisons with the sedimentological features offered by the pleistocene alluvial fan deposits of the pimonte area (aucelli et al., 1996), a confined alluvial fan interpretation may be proposed as the nocella conglomerates consists mainly of stackedsheets of graded and massive clast-supported conglomerate, which can be traced over a distance of several meters; in fact the gathered data are indicative of deposition and migration of low-relief longitudinal bars in shallow, high-velocity gravel-bed stream. but the lack of other outcrops beside that of nocella does not enable us to definitely confirm this hypothesis as an abrupt basinward facies transition may not be observed. although a vertical change from more distal to proximal fluvial settings is suggested by both the disappearing of macroforms interpreted as laterally accretion of gravelbars and the upward abrupt increase of high energy flow deposits (gcm and gci lithofacies). in order to interpret the vertical change of the facies associations within the nocella succession, different factors can be considered. first of all the angular to subrounded shape of the nocella conglomerates clasts prove that slope deposits produced by paipo fault scarp retreat are poorly reworked by fluvial processes as the absence of slope deposits interfingering with fluvial ones suggest. a climatic factor could also be considered to unravel the varying vertical facies association of the nocella conglomerates: the river models deduced by analysing the facies architecture may witness a decrease of water discharge and/or an increase of sediment supply. the abrupt transition from fluvial deposits to slope ones should be due to early – middle pleistocene re-activation of the southern segment of the scrajovettica fault zone which could have beheaded the upper reach of the catchment. conversely, the same abrupt transition could also be due either to a sudden lateral (south-westward) shifting of the watercourse or to the advancing of the debris slope after a phase of downcutting. moving north-westward suspended at about 600 – 650 m a.s.l. stand the s. maria del castello ii order relic (figg. 2 and 3) and a small erosional hanging terrace both sealing the scrajo – vettica fault. also the paipo breccias, located south-eastward of nocella site, seal the older segment of the scraio-vettica fault zone. these erosional and depositional landforms have been interpreted to belong to the same geomorphological stage, apart from the uppermost slope deposits which could also be more recent, in the case of a preceeding phase of downcutting or tectonic behading of the upper catchement. as a whole it was concluded that the paleomorphology of the study area, at the time of the nocella conglomerates deposition, was quite different from the modern one. the source area of the nocella conglomerates has to be related to a small river catchment nested into a nowadays lost morphostructural high located east-southeastward of the study area (fig. 2). this topographic high had to include also the mountainous area that fed the clastic infilling of the agerola karstic basin, whose western deposits show a clear dip towards northeast (brancaccio et al., 1976; cinque, 1986). moreover, the gentle landscape of s. maria del castello site settled at the footslope of the scraiovettica maggiore fault scarp, represents the wnw part of a low relief landscape, that we interpret as part of the wnw-sloping paleoslope of the river basin in which the nocella conglomerates were deposited. in order to better clarify the chronological frame of the ii order palaeosurface and its correlative deposits of nocella formation we summarize the whole geomorphological evolution of the sorrento peninsula. the oldest geomorphological stage is recorded by the formation of the i order palaeosurface (fig.9-i) there follows a phase of block-faulting driven by nesw direction of extension led to the fragmentation of this landscape, well documented by the structural analysis carried out on the scraio vettica fault (fig. 9-ii; caiazzo et al., 2000). after the early pleistocene activity, the ii order palaeosurface developed with a base–level ranging between 600 – 750 m a.s.l.(fig. 9iii). as reported by caiazzo et al., 2000 part of the scraio vettica fault zone was reactivated during early pleistocene – middle pleistocene p.p. and driven by nw-se direction of extension; the only southern segment coinciding with the present structural sea-cliff between positano and vettica towns moved during this more recent phase. after the early pleistocene – middle pleistocene p.p. tectonic phase, the relics of the ii order landscape were suspended, the nocella fm. and the paipo breccias were truncated, and, seemingly, whole portions of the ii order landscape (southern portions of the area) which had to represent the source area of these clastic units, were definitively drowned (fig. 9-iv). as a consequence, the age of the ii order palaelandscape should be early pleistocene. 55.. ccoonncclluussiioonn we have reconstructed the early pleistocene palaeolandscape of a portion of the eastern sorrento peninsula by detailed geomorphologic survey and sedimentological analysis of the nocella formation. on the basis of our data this hanging succession, previously interpreted as entirely composed of slope breccias, consists of a basal portion (about 90m thick) of alluvial deposits (nocella conglomerates), overlain by stratified slope deposits (nocella breccias). the nocella conglomerates can be referred to the geomorphologic stage immediately successive to the tectonic fragmentation of the i order palaeosurface (pliocene early pleistocene in age), which is the oldest geomorphologic element of this region (fig. 9). at that time the blockfaulting caused the deepening and widening of the gulf of salerno and allowed the sorrento peninsula to be further uplifted; in the meanwhile the width of the peninsula itself was progressively reduced and the agerola tectonic depression was created. during this period the peninsula was towards the south still wider and lower in elevation than today. subsequently a period of relative tectonic stability occurred and a new generation of low relief landscape (ii order palaeosurface) was formed. uplifted remnants of the ii order palaeosurface occur in several places at elevations from 500 m to 800 m (fig. 2). in fact the agerola graben, whose southern rim at present is open towards the south, by that time was entirely closed and received clastic imputs also from the southern reliefs. these ones had to include also the mountainous area into which a small river catchment had to be nested and fed the clastic infilling of nocella palaeovalley; the sedimentologic analysis of the nocella conglomerates also suggests a source area which extended for some km to the south-east. the palaeovalley had to be flanked by mt. tre calli to the northeast and some other reliefs of similar height (higher than about 800m in any case) to the south-west. these reliefs were part of morphostructural high which close towards the south and fed the alluvial clastic infilling of the agerola depression. furthermore, the s. maria del castello ii order surface has been interpreted as the basinward portion of the low gradient paleoslope on which the nocella river was flowing. other small hanging concave up footslopes (erosional landforms beside moiano, ticciano and massaquano settlements), have been interpreted as erosional and deposit ional landforms connecting the scrajo-vettica fault scarp to the nocella river valley. after the development of the the ii order palaeosurfaces, the study area was affected by a tectonic phase driven by a nw-trending direction of extension which allow netrending fault scarps to be formed (caiazzo et al., 2000). according to the authors this tectonic event may be ascribed to the beginning of the middle pleistocene. furthermore, the southern segment of the scrajo-vettica fault zone was reactivated as tran94 a. amato g. robustelli fig. 9 main stages of the morphotectonic and the drainage evolution of the study area. c marks s.maria al castello; nn marks nocella site; ff marks mt. faito; ttpp marks s. angelo a tre pizzi; ttcc marks mt. tre calli; a marks agerola; i, ii, iii; iv modified from caiazzo et al. (2000); • • : beheaded valley; � �: relic valley; �: river capture. principali tappe dell’evoluzione morfotettonica e del reticolo idrografico. le lettere cc, nn, ff, ttpp, ttcc, aa, indicano rispettivamente le località di s.maria al castello, il sito studiato di nocella, m. faito, m. s. angelo a tre pizzi, m. tre calli ed agerola. i, ii, iii e iv modificate da caiazzo et al. (2000); • •: valli tronche;� �: valli relitte; �; catture fluviali. 95 sfer fault. the peninsula was progressively reduced by block faulting that affected its southern flank which enlarged the contiguous gulf of salerno and drawing the present-day coastal profile. aacckknnoowwlleeddggeemmeennttss the authors wish to thank prof. a. cinque for the helpful field discussions and the useful comments on early draft of the manuscript. this article benefited from helpful review and suggestions by l. brancaccio and m. sagri. rreeffeerreenncceess aucell i p.p.c., cinque a. & merola d., 1996 discriminazione cronologica di eventi deformativi fragili lungo il margine settentrionale dei monti lattari sulla base di dati geologici e geomorfologici. il quaternario, 9, 319-324. bartole r., savell d., tramontana m. & wezel c. f., 1984 – structural and sedimentary features in the tyrrhenian margin off campania, southern italy. marine geology, 5555, 168-180. bluck b. j., 1979 – structure of coarse grained braided stream alluvium. transactions of the royal society of edinburgh, 7700, 181-221. bonardi g., d’argenio b. & perrone v., 1988 – carta geologica dell’appennino meridionale alla scala 1:250.000. mem. soc. geol. it., 4411, 1341. brancaccio l., cinque a. & sgrosso i., 1976 – la grotta di s. barbara nel contesto della evoluzione geomorfologia della piana di agerola. ann. speleol., c.a.i., napoli, 33. brancaccio l., cinque a. & sgrosso i., 1979 – l’analisi morfologica dei versanti come strumento per la ricostruzione degli eventi neotettonici. mem. soc. geol. it., 1199,, 621-626. bridge j.s., 1993 – description and interpretation of fluvial deposits: a crit ical perspective. sedimentology, 4400, 801-810. caiazzo c., cinque a. & merola d., 2000 – relative chronology and kinematics of the nw and ne trending faults of the sorrento peninsula (southern apennines). mem. soc. geol. it., 5555, 165-174. cinque a., patacca e., scandone p. & tozzi m., 1993 – quaternary kinematic evolution of the southern apennines. relationship between surface geological features and deep lithospheric structures. ann. geofis., 3366, 249-260. cinque a. (a cura di), 1986 – guida alle escursioni geomorfologiche. penisola sorrentina, capri, piana del sele e monti picentini. gruppo naz. geogr. fis. e geomorf., amalfi 9-12 giugno. pubbl. n.33 del dip.to scienze della terra, università di napoli “federico ii”, 120pp.. cinque a. & romano p., 1990 – segnalazione di nuove evidenze di antiche linee di riva in penisola sorrentina. geogr. fis. din. quat., 13, 23-36. collinson j. d., 1986 – alluvial sediments. in: reading h. g. (ed.). sedimentary environment and facies. blackwell scientific publications, oxford, 20-62. hein f. j. & walker r. g. , 1977 – bar evolution and development of stratification in the gravely, braided kicking horse river, british columbia. can. j. earth sci., 1144,, 562-570. jo h. r. & chough sk., 2001 – architectural analysis of fluvial sequences in the northwestern part of kyongsang basin (early cretaceous), se korea. sediment. geol., 114444, 307-334. kraus m. j., 1984 – sedimentology and tectonic setting of early tertiary quartzite conglomerates, northwest wyoming. in: koster e. h., steel r. j. (eds). sedimentology of gravels and conglomerates. can. soc. petrol. geol. mem., 1100, 203-216. lowe d. r., 1982 – sediment gravity f lows: ii. depositional models with special reference to the deposits of high-density turbidity currents. j. sediment. petrol., 5522, 279-297. maizels j., 1993 – lithofacies variations within sandur deposits: the role of runoff regime, flow dynamics and sediment supply characteristics. sediment. geol., 8855, 299-325. miall a. d., 1977 – a review of the braided river depositional environment. earth sci. rev., 1133,, 1-62. miall a. d., 1985 – architectural elements analysis: a new method of facies analysis applied to fluvial deposits. earth sci. rev., 2222, 261-308. miall a. d., 1988 – facies architecture in clastic sedimentary basins. in: kleinspehn k., paola c. (eds). new perspectives in basin analysis. springer, new york, 67-81. miall a. d.., 1996 – the geology of fluvial deposits: sedimentary facies, basin analysis and petroleum geology. springer, new york, pp.582. milia a., 1996 – evoluzione tettono-stratigrafica di un bacino peritirrenico: il golfo di napoli. tesi di dottorato, università di napoli “federico ii”, pp.184. milia a. & torrente m. m., 1997 – evoluzione tettonica della penisola sorrentina (margine peritirrenico campano). boll. soc. geol. it., 111166, 487-502. nemec w. & postma g., 1993 – quaternary alluvial fans in southwestern crete: sedimentation processes and geomorphic evolution. in marzo m., puigdefabregas c. (eds) alluvial sedimentation. int. assoc. sedimentol. spec. publ., 1177, 235-276. nemec w. & steel r. j., 1984 – alluvial and coastal conglomerates: their significance features and some comments on gravelly mass-flow deposits. in: koster e. h., steel r. j. (eds). sedimentology of gravels and conglomerates. can. soc. petrol. geol. mem., 1100, 1-31. pierson t. c, 1980 – erosion and deposition by debris flows at mt. thomas, north canterbury, new zealand. earth surf. proc., 55, 227-247. pierson t. c & scott k. m., 1985 – downstream dilution of a lahar: transition from debris flow to hyperconcentrated streamflow. water resour. res., 2211, 1511-1524. ramos a. & sopena a., 1983 – gravel bars in lowsinuosity streams. (permian and triassic, central spain). in: collinson j. d., lewin j. (eds) modern and ancient f luvial systems. int. assoc. sedimentol. spec. publ., 66, 301-312. rust b. r., 1978 – depositional models for braided alluvium. in: miall a. d. (ed.). fluvial sedimentology. can. soc. petrol. geol. mem., 55, 605-625. the nocella conglomerates ... ridgway k. d. & decelles p. g., 1993 – stream-dominated alluvial fan and lacustrine depositional systems in cenozoic strike-slip basins, denali fault system, yukon territoty, canada. sedimentology, 4400, 645-666. sacchi m., infusino s. & scarsella e., 1994 – late pliocene-early pleistocene compressional tectonics in offshore campania (eastern tyrrhenian sea). boll. geof. teor. appl., 3366, 469-482. sartori r., 1989 – evoluzione neogenico-recente del bacino tirrenico e i suoi rapporti con le aree circostanti. gior. di geol. it., 3388, 225-240 sartori r., 1990 – the main results of odp leg 107 in the frame of neogene to recent geology of the perityrrhenian areas. in: kastens k. a., mascle j. et al. – proc. odp sci. results, 110077, 715-730. scott k. m., 1988 – origins, behaviour, and sedimentology of lahars and lahar-runout flows in the toutlecowlitz river system. u.s. geol. surv. prof. paper, 11444477--aa, a1-a74. shultz a. w. (1984) – subaerial debris-flow deposition in the upper paleozoic cutler formation, western colorado. j. sediment. petrol., 5544, 759-772. smith g. a., 1986 – coarse-grained nonmarine volcaniclastic sediment: terminology and depositional processes. geol. soc. am. bull., 9977,, 1-10. smith g. a. & lowe d. r., 1991 – lahars: volcanohydrologic events and deposition in the debris flow-hyperconcentrated flow continuum. in: fisher r. v., smith g. a. (eds) sedimentation in volcanic settings. sepm, spec. pubbl., 4455, 59-70. sohn y. k., rhee c. w. & kim b. c., 1999 – debris flow and hyperconcentrated flood-flow deposits in an alluvial fan, northwestern part of the cretaceous yongdong basin, central korea. j. geol., 110077, 111-132. steel r. j. & thompson d. b. (1983) – structures and textures in triassic braided stream conglomerates (“bunter” pebble beds) in sherwood sandstone group. north staffordshire. england. sedimentology, 3300, 341-367. todd s. p. (1989) – stream-driven, high-density gravelly traction carpets: possible deposits in the trabeg conglomerates formation, sw ireland and some theoretical considerations of their origin. sedimentology, 3366, 513-530. waresback d. b. & turbeville b. n., 1990 – evolution of a plio-pleistocene volcanogenic-alluvial fan:the puye formation, jemez mountains, new mexico. geol. soc. am. bull., 110022, 298-314. 96 a. amato g. robustelli ms. ricevuto il 26 marzo 2002 testo definitivo ricevuto il 28 maggio 2002 ms. received: march 26, 2002 final text received: june 28, 2002 sess 2_16022011_tpr3.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 lidar applications to quaternary geology of high mountain areas: examples from val di fassa (dolomites) thomas zanoner1, alberto carton1, alessandro fontana1, mirco meneghel1 & marco stefani2 1 department of geography ‘‘g. morandini’’,university of padua, padova, italy 2 department of earth science, university of ferrara, ferrara, italy corresponding author: t. zanoner <thomas.zanoner@gmail.com> abstract: zanoner t. et al., lidar applications to quaternary geology of high mountain areas: examples from val di fassa (dolomites). (it issn 0394-3356, 2011) information obtained from lidar-derived dems, photointerpretation and field survey were compared; results demonstrate the reliability of lidar in the recognition of landforms and deposits in the dolomitic areas of val duron and passo san pellegrino. riassunto: zanoner t. et al., applicazione di dati lidar per lo studio della geologia del quaternario in aree di alta montagna: esempi dalla val di fassa (dolomiti). (it issn 0394-3356, 2011) si sono confrontati i risultati ottenuti dall'utilizzo di dem da lidar, fotointerpretazione e rilievo sul terreno; i risultati dimostrano che il lidar è un valido strumento per il riconoscimento e la mappatura delle forme del terreno e dei depositi quaternari. i casi studio sono le zone dolomitiche della val duron e del passo san pellegrino.  key words: dolomites, geomorphology, dem, remote sensing, glacial deposits, paraglacial deposits parole chiave: dolomiti, geomorfologia, telerilevamento, dem, depositi glaciali, depositi paraglaciali the lidar (light detection and ranging) is based on the use of a laser scanner measuring the distance existing among sensor and ground surface. if the scanner is transported by an aircraft and the acquisition corrected with an imu (inertial measurement unit) and a differential gps, large areas could be surveyed in short time with a vertical precision of 7-20 cm (heritage & large, 2009). the method is rapid, relatively economic and allows survey of difficult terrain, as high-mountain regions, where conventional ground-based survey methods are impossible or very difficult and expensive. the topographic data, acquired as clouds of points in ascii format (x, y, z) could be processed obtaining digital surface model and digital elevation model (i.e. dsm and dem) at various scales with a cell-size dimension of 0.5-2 m. the use of hillshade or other digital process could enhance the ground morphologies helping the recognition of landforms and structural features of an area. problems of distortions or artifacts (e.g. striping effect) on the images or on the derived dem should be considered. in the mountains, where rocky slopes could be very high, the lidar acquisition could be problematic because laser-based systems are affected by beam divergence if slope are steeper than 70°. this effect is accentuated at increasing distances from the scanner both in vertical and horizontal plane (heritage & large, 2009). the lidar operates collecting the so-called first and last-pulse. first-pulse measures the range to the first object encountered (in many this is vegetation, for example tree foliage); last-pulse: measures the range to the last object (the ground surface under the foliage). the recent instrumentations could record both the first and the last return and also the intermediate impulses (caused by ramifications of the plants) and this allows to obtain information on the surface and remove the vegetation and the urban built. it is possible to discriminate forms and deposits under vegetal cover that makes invisible the geology with the normal remote sensing and often also with the geological ground survey. hence, airborne-laser scanning has become one of the primary choices for gathering precise and dense dems of large areas for a wide range of applications. lidar has currently become an important scientific tool in forestry, geology (latu sensu), archaeology, agriculture. it is a major tool for river and alluvial geomorphology, but the applications related to the quaternary geology and geomorphology in highmountain environments are still few. despite its positive characteristics, at the moment the lidar topography is available only for limited italian areas, but among them the whole area of the province of trento was surveyed and its cover a large portion of the dolomites. in this work we tested the reliability of lidar-derived dem for quaternary geology researches in two sample areas in the dolomites: val duron and passo san pellegrino in the val di fassa valley (fig. 1). these are two areas already studied and their are 135 137 136 geological field survey carried out at scale 1:10,000 using the topographic base the carta tecnica provinciale of trento. the ground survey demonstrated the validity of the indirect analysis previously performed. the use of remote sensing information, in particular the lidar, is largely usefull to characterize landforms and deposits which, sometimes, are very difficult to understand or even to see in the field due to vegetation cover and/or the lack of clear outcrops. the research benefits of the detailed information concernig the geological bedrock (mainly permian and triassic formation), collected through the geological maping carried out in the last 15 years in this area and already overlapped to the lidarderived dem (marco stefani, unpublished). this geological data allowed to identify and discriminate some areas were the pre-quaternary substratum consists of silico-clastic formations with a surface aspect apparently similar to the some quaternary deposits. in the test areas there are some cases which can illustrate the different characteristics of the 3 methods used for the geomorphological analysis (i.e. field survey, photo interpretation and analysis of lidar data). these highlight how important are the lidar images in resolving some geomorphological problems. in both the zones the dem, filtered from vegetation, allow to identify slope and glacial deposits that in the former researches were generally mapped in a worse way and sometimes even unknown or overestimated. as wrote before, the use of these tools and other methods based on remote sensing needs to be carefully checked with ground truths; but, after validation, the areas where field survey is needed and essential could be reduced in their number and extent. however our experience supports the idea that lidar and photointerpretation could not replace the field work. moreover, the field work is important to achieve the right scale of survey, because sometimes, especially with the lidarcharacterized by the presence of major glacial, paraglacial and periglacial landforms and deposits (castiglioni, 1926; 1930; rossi, 1955; 1962; bianchi castiglioni, 1960; castiglioni, 1964; panizza et al., 1978; carton & pelfini, 1988). for this study the topographic analyses and elaborations were carried out on the dem derived by the lidar survey realized by the provincia autonoma di trento between 2006-2008. the dem supported by this institution was already filtered of the anthropic features and corrected. the lidar survey had a point density of a minimum of 8 points per cell when cells are 2.5x2.5 m and a minimum of 12 points for cells of 5x5 m. the sensor recorded the first and the last return of the laser beam and the mean percentage of penetration of forest cover (deciduous forest) was about 90%. the altitude precision obtained spans between 10 and 30 cm. in this work, beside lidar data, conventional remote sensing analyses were performed, consisting in photo interpretation of the areas through binocular stereoscope and monitor analysis of digital orthophotos at scales ranging from 1:5,000 to 1:10,000. all these indirect interpretations were subsequently checked with a geomorphologicalfig. 2, the val tegnuosa rock glacier in the orthophoto (left) and in the lidar-derived dem (right). il rock glacier della val tegnuosa visto nell'ortofoto (sinistra) e nel dem da lidar (destra). fig. 1, location of the studied areas. ubicazione delle aree studiate. t. zanoner et al. 137 ms. received: testo ricevuto il derived images, there is the risk to be trapped in a too detailed analysis, which consumes time and energy and sometimes leads to lose the sense of the general setting inducing errors of interpretation. in the val duron, the lidar images enphasizes the structural component of the landscape, allowing a better understand of a river capture originally described by panizza et al. (1978); this was tectonically driven by a structural pattern which induced also an important landslide. in fact in this valley lidar permits to recognize also two landslides that have probably blocked the valley for sometime. one of these slope features probably occurred during deglaciation, the other had not been detected before this research due to the forest cover. other landforms which are nicely highlighted by lidar are represented by fluvial terraces, alluvial cones and talus screes. near the passo del s. pellegrino, beside morfostructures, gravitational processes and river terraces, lidar was really helpful in analysing karst morphology (e.g. doline field), glacial, paraglacial and periglacial phenomena, as described in the following examples. near the place of fuciade, photointerpretation didn't provide safe information about the genesis of a complex shaped deposit. field survey revealed a glacial and paraglacial origin but without lidar data it was hadrly to map clearly a rock glacier and separate it from an adjacent glacial deposit. the dem allowed to map rapidly and in detail the lobes of the rock glacier, while they have a lower evidence in the aerial photos. due to hummoky topography field survey doesn't provide a map with a detail cmparable to the one obtained from lidar. the correct representation of the lobes is important to support considerations on the variations of speed and direction experienced by a rock glacier. a nice example is represented by the val tegnousa rock glacier, already considered in bianchi castiglioni, 1960 and in carton ,1980. with lidar-supported investigations it is possible to distinguish the various stages of development that the rock glacier has undergone. other forms that can be better mapped using lidar are the moraine ridges at the altitude of passo san pellegrino, which presently are completely covered with vegetation and often broken up or smashed by anthropogenic or natural causes. due to these motivation their identification and thus also their mapping is not always easy from aerial photographs or with the ground survey. after careful analysis it’s possible to reconstruct the different phases of glacial advances and retreats. the authors thank the protezione civile and servizio geologico of the provincia autonoma di trento for the lidar-derived dem used in this research. dem were processed by f. ferrarese. references: carton a. & pelfini m. (1988) forme del paesaggio d'alta montagna. collana: scuola di montagna, zanichelli, bologna, 136. carton a. & de luigi e. (1980) – le valli s.pellegrino, monzoni e s. nicolò (dolomiti). c.a.i. comitato scientifico, itinerari naturalistici e geografici attraverso le montagne italiane. bianchi castiglioni g. (1960) – osservazioni morfologiche sulla valle di san pellegrino nelle dolomiti. rivista geografica italiana, 67 (4), 393-415. castiglioni b. (1926) – sulla morfologia della valle del biois (alpi dolomitiche). bollettino società geologica italiana, xlv (2), 193-221. castiglioni b. (1930) – tracce glaciali postwurmiane nelle dolomiti. atti xix riunione soc. ital. progr. scienze, ii. castiglioni g.b. (1964) – sul morenico stadiale nelle dolomiti. memorie degli istituti di geologia e mineralogia dell'università di padova, 24, 1-16 (allegata carta 1:125.000). castiglioni g.b. (1967) – carta delle morene stadiali della regione dolomitica. in leonardi p. (1967) le dolomiti, geologia dei monti tra isarco e piave, 2 vol. heritage g.l. & large a.r.g. (eds) (2009) laser scanning for the environmental science. wileyblackwell publishing, 302. panizza m., carton a., castaldini d, mantovani f. & spina s. (1978) – esempi di morfotettonica nelle dolomiti occidentali e nell’appennino modenese. geogr. fis. dinam. quat., 1, 28 – 54. rossi d. (1955) – studio geologico-petrografico sulla regione catinaccio val duron (dolomiti di fassa). centro studi di petrografia e geologia del consiglio nazionale delle ricerche, padova 1955, 3-47. rossi d. (1962) – geologia della parte meridionale del gruppo della marmolada. mem. mus. sc. nat. venezia trid., col. xiv (1/b)  january 15, 2011 15 gennaio 2011 lidar applications to quaternary geology of high ... evoluzione morfologica di alvei fluviali mobili nel settore occidentale del bacino padano luisa pellegrini1, franca maraga2, ornella turitto2, chiara audisio2 & gabriele duci1 1dipartimento di scienze della terra, università di pavia via ferrata, n. 1 27100 pavia 2consiglio nazionale delle ricerche dipartimento terra e ambiente istituto di ricerca per la protezione idrogeologica, sede di torino strada delle cacce, n. 73 10135 torino e-mail: lpellegr@unipv.it riassunto: l. pellegrini et al., evoluzione morfologica di alvei fluviali mobili nel settore occidentale del bacino padano (it issn 03943356, 2008). nell'ambito delle ricerche riguardanti le modificazioni di alvei fluviali, sono stati selezionati alcuni corsi d'acqua significativi per confronto delle analisi di tendenza evolutiva delle forme a canali multipli o intrecciati (pluricursali). in particolare, per quanto attiene al sistema padano occidentale, sono stati individuati tre affluenti del fiume po: il fiume stura di lanzo ed il torrente orco, di provenienza alpina, ed il fiume trebbia, di provenienza appenninica. per il periodo considerato, che va dalla seconda metà dell'ottocento all'inizio degli anni duemila, tali corsi d'acqua si sono rivelati rappresentativi degli stadi di evoluzione dall'alveo pluricursale verso l'alveo a canale singolo (monocursale, quantomeno per alcuni tratti), con riduzione dello spazio fluviale, manifestatasi fino a tutti gli anni ottanta del novecento. la riduzione di ampiezza degli alvei, in un primo tempo moderata (da -19% in trebbia a -36% in stura), inizia ad essere vistosa e rapida dopo gli anni cinquanta del secolo scorso, in concomitanza del diffondersi di massicce estrazioni di inerti dagli alvei. il massimo restringimento (da -44% in orco a -68% in stura) è stato registrato intorno al 1990. a partire dagli anni novanta, peraltro, è stata riscontrata una tendenza inversa, messa in evidenza da espansione degli alvei con valori di allargamento variabili da +15% in trebbia a +133% in orco. la fase di restringimento dell'alveo è stata accompagnata da fenomeni di allungamento del percorso fluviale, con valori minimi in stura di lanzo e in trebbia (inferiori a 1%) e massimi in orco (+8%). nella successiva fase di allargamento si è riscontrata una più o meno marcata e concomitante riduzione della lunghezza dell'alveo, appena percettibile in stura di lanzo e trebbia e pari a -6% in orco. tale inversione di tendenza, da riduzione ad espansione dell'alveo pluricursale e da allungamento ad accorciamento del suo asse, è stata associata alla quasi totale cessazione della massiccia attività estrattiva in alveo. per i corsi d'acqua alpini, un ruolo importante è stato attribuito anche alla rapida successione di eventi di piena avvenuti a partire dal 1993, tra i quali, in particolare, quello dell'ottobre 2000 che ha rappresentato il massimo storico su oltre 80 anni di osservazioni. abstract: l. pellegrini et al., river channel adjustment in the western po system (northern italy) (it issn 0394-3356, 2008). the research on channel changes in italian rivers has pointed out processes of incision and narrowing during the last fifty years. the definition of the causes and the practical implications of such variations has stimulated a wish to know more about this phenomenon. as study cases for analysing the trends in the western sector of the po system, three po river tributaries have been selected: the rivers stura di lanzo and orco, both from the alps, and trebbia, from the apennines, flowing into the po river, respectively at 205 m, 177 m and 43 m a.s.l.. through gis procedures (for orco and trebbia) and digitizer elaboration (for stura di lanzo) and using a topographic map on a 1:10.000 scale as a base layer, the morphological changes of the river channel have been deduced comparing historical maps dating from the end of the 1880s to the 1950s (on a 1:25.000 scale), aerial photographs dating from the 1950s (at scales ranging between 1:45.000 and 1:5.000) and satellite images (70 cm resolution); topographic observation and field surveys have allowed us to verify the present situation. the stura di lanzo river develops a braided reach 10.5 km long in the upper alluvial plain. the braided pattern was modelled in coarse gravels. the largest narrowing modifications took place until the 1990s, due to sediment gravel mining. this adjustment caused a width reduction of 80% (1881-1989) along the braided reach that was previously 600 m wide and a 4 m deep channel incision that locally downcuts the fine sediments of buried lacustrine deposits. a local single channel modelling has definitively started since the 1980s, due to the fact that the fine sediments in the bed are unable to maintain the former braided pattern. the studied reach of the orco river (25 km long, in the middle-lower plain), is incised into a fluvioglacial fan and the po alluvial plain. over the 19th century the river channel showed a multi-thread morphology, with a braiding intensity variable in space and time. the progressive simplification of the pattern, already observed since the end of the 19th century, has undergone a diffuse acceleration starting from the 1950s (average reduction of 60% in width over the 1881-1990 period). the analysis of human intervention and floods pointed out two opposing roles: the role of man in starting or accelerating the process of the river pattern simplification; the role of the floods in attempting to restore the previous pattern in the plain. the investigated reach of the trebbia river, 31 km long, is characterized by a braided morphology. a continuous narrowing of the channel has appeared since 1877 (average reduction of 65% in width over the 1877-1990 period). this narrowing reached reductions of 58% between 1954 and 1990 (during the period of most intense gravel mining) and was accompanied by a channel incision of 2-4 meters. in all studied rivers the channel narrowing, which occurred up to 1990, was characterized by a lengthening of the channel axis. starting from 1990, the rivers showed a reversal of the previous trend, because channel widening took place, concomitant to a shortening of the channel axis. in the alpine watercourses the opposite trend could be a result of the extreme flood that occurred in 2000; in trebbia river, the almost total cutback of large-scale gravel mining must be considered. parole chiave: modificazioni delle forme fluviali, alvei ghiaiosi, impatto antropico, fiume stura di lanzo, torrente orco, fiume trebbia, italia nord-occidentale. keywords: channel changes, gravel bed rivers, human impact, stura di lanzo river, orco river, trebbia river, north-western italy. il quaternario italian journal of quaternary sciences 21(1b), 2008 251-266 252 l. pellegrini et al. 1. introduzione ricerche riguardanti le variazioni morfologiche degli alvei pluricursali, non confinati o semiconfinati, hanno messo in particolare evidenza processi di progressivo restringimento e incisione in molti corsi d'acqua italiani del sistema padano-veneto e del sistema appenninico centrale (ca s t i g l i o n i & pe l l e g r i n i, 1981; fr a n c e s c h e t t i et al. , 1990; canuti et al. , 1992; ma r c h e t t i, 2002; ri n a l d i, 2003). tali processi, già riscontrati su base cartografica d'epoca a partire dai secoli passati, si sono rivelati particolarmente intensi negli ultimi cinquant'anni, in base ad osservazioni e misurazioni derivate da indagini comparate su fotografie aeree e da rilevamenti di terreno (govi, 1976; pellegrini et al., 1979; coltorti et al., 1991; maraga, 1992; govi & turitto, 1993; maraga et al., 2003). il restringimento del sistema pluricursale, documentato fino agli anni ottanta del secolo scorso, ha comportato una sensibile riduzione dello spazio di deflusso laterale degli alvei che prima competeva alle libere manifestazioni dell'attività fluviale: infatti è stata riscontrata la preclusione di rami secondari e la congiunzione al territorio rivierasco dei margini delle isole fluviali più esterne. spesso, tra le cause che hanno influito sui suddetti processi fluviali, sicuramente sulla loro accelerazione, sono stati riconosciuti gli interventi antropici, quali le opere di sistemazione idraulica e, ancor più, la pratica delle escavazioni di inerti in alveo, particolarmente diffusa tra gli anni sessanta e ottanta (surian & ri n a l d i, 2003; ri n a l d i et al., 2005; su r i a n et al., 2005; surian, 2006). con gli anni novanta è stata osservata una tendenza morfologica inversa, con forme d'alveo che riprendono espansione, dando indizio di una nuova fase evolutiva diretta verso il ripristino di precedenti o nuove dimensioni fluviali (surian & rinaldi, 2004). il riconoscimento delle attuali forme evolutive e delle interazioni fiume-territorio, in relazione all'inversione di tendenza, ha stimolato gli approfondimenti di studio su conoscenza, distribuzione spaziale ed intensità del fenomeno, ponendo a confronto una casistica di situazioni rappresentative. le attività della presente ricerca, sviluppate nell'ambito del progetto di rilevante interesse nazionale (prin 2005-2007) “dinamica recente ed attuale di alvei fluviali in italia centro-settentrionale: tendenze evolutive, cause ed implicazioni applicative”, riguardano corsi d'acqua pluricursali della rete idrografica del fiume po, distribuiti nella fascia pedemontana di raccordo tra il fronte alpino o appenninico e la pianura padana, costituita da depositi ghiaiosi di ampi conoidi fluvioglaciali e fluviali. nel settore occidentale del sistema padano l'andamento pluricursale si sviluppava in molti corsi d'acqua fino alla confluenza nel fiume po. il modello pluricursale ha marcatamente ridotto nel tempo le sue forme e dimensioni, attraverso una sistematica riduzione di larghezza, documentata dall'idrografia storica e dalle forme relitte riconoscibili all'intorno degli attuali percorsi fluviali. la riduzione ha innescato locali trasformazioni dell'alveo, con deflussi contenuti in un solo canale, localmente inciso in profondità entro un corpo sedimentario sabbioso-limoso prefluviale, prima sepolto dai depositi ghiaiosi. in tale assetto sedimentario si è quindi prodotto un vistoso mutamento della configurazione dell'alveo stesso dalle originarie forme pluricursali in forme di transizione verso i modelli monocursali ( ra m a s c o & ro s s a n i g o, 1988; ma r a g a, 1989; du t t o & maraga, 1994). dagli anni novanta sono state rilevate forme di allargamento dell'alveo, con riconfigurazione di margini di sponda, con riattivazione di rami laterali abbandonati e con nuova alimentazione sedimentaria di barre. tali indizi di rimodellamento e ripascimento naturale, tuttavia, sono ben lungi dal riproporre le originarie forme e dimensioni dello sviluppo pluricursale. i risvolti applicativi connessi a questo recente fenomeno di allargamento degli alvei fluviali possono assumere un aspetto fondamentale nella scelta dei criteri da adottare per la futura gestione dei corsi d'acqua. oltre a norme istituzionali dettate dalla necessità di permettere la funzionalità idraulica lungo la rete idrografica padana (autorità di bacino del fi u m e po, 1998; 1999; 2005), oggi l'attenzione dei geomorfologi fluviali si è più specificatamente rivolta alla individuazione dei caratteri evolutivi delle forme sedimentarie e degli spazi da destinare al corso d'acqua per garantire, attraverso l'erosione di sponda, un'importante fonte di sedimenti per il trasporto solido, elemento indispensabile alla naturale modellazione dell'alveo (du t t o & ma r a g a, 1991; ma l av o i et al., 1998; pi é g a y et al., 2005; pi t t a l u g a et al. , 2006; rinaldi, 2006; habersack et al., 2008). tali presupposti rappresentano una significativa svolta nella gestione degli ambiti fluviali, in quanto orientano verso approcci tesi ad assecondare le dinamiche morfologiche piuttosto che a contrastarle con interventi di sistemazione idraulica che, spesso, si sono rivelati non idonei, se non pericolosi o dannosi per beni pubblici e privati. 2. inquadramento dei casi di studio nel sistema padano occidentale la scelta dei corsi d'acqua da sottoporre ad indagine morfologica multitemporale (150 anni circa), per l'individuazione delle variazioni di forma dell'alveo e per la definizione delle tendenze evolutive fluviali, ha tenuto conto di criteri relativi alla distribuzione geografica di pertinenza alpina e appenninica, alla conoscenza specifica di alvei pluricursali rappresentativi della morfodinamica attuale, alla disponibilità di documentazioni storiche e di dati pregressi, nonché di ripetute e aggiornate riprese aeree. sono stati, quindi, selezionati tre corsi d'acqua confluenti nel fiume po a quote 205 m, 177 m e 43 m s.l.m., rispettivamente: il fiume stura di lanzo e il torrente orco, tributari alpini, e il fiume trebbia, tributario appenninico (fig. 1 e tab. 1). il fiume stura di lanzo è affluente alpino del fiume po in alta pianura padana (provincia di torino), alimentato da un bacino montano di 627 km2 (ministero ll.pp., 1925), con quota massima di 3676 m s.l.m. (uja di ciamarella), con 12% di aree glaciali, chiuso 100 m a valle della stazione idrometrica di lanzo torinese (zero idrometrico a quota 446,86 m s.l.m.-mi n i s t e r o l l . p p . , 1980). esce nella pianura fluviale olocenica con terrazzamento di un conoide fluvioglaciale, senza fronte morenico, e sviluppa un percorso totale di 80 km dalla sorgente alla confluenza in po a torino (quota 205 m s.l.m.) di cui gli ultimi 30 km nella pianura fluviale. il fiume aveva modellato nei 30 km di pianura un alveo pluricursale, configurato in sequenza di tratti con maggiore e minore frequenza di isole, larghi più di 800 m nella seconda metà del 1800. negli anni '50 del '900 il fiume presentava l'andamento pluricursale regredito a 20 km di percorso dallo sbocco in pianura, con larghezza massima ridotta a 600 m. più vistose riduzioni di larghezza, dovute alla riduzione delle isole, si sono rilevate dopo gli anni '50, in concomitanza di una diffusa e continua campagna di estrazione d'inerti e di un periodo di piene minori. nel 1975 il campo di attività pluricursale era ridotto a valori di larghezza massima contenuti entro i 300 m e nel 1989 era regredito ancora più verso 253evoluzione morfologica di alvei ... monte, lungo il percorso di 10,5 km dallo sbocco in pianura, dove la larghezza massima era ulteriormente ridotta entro i 200 m (fig. 2). tale tratto, attualmente ancora pluricursale solo nella sua porzione di monte (1-2 in fig. 2), è stato assunto a campione dell'evoluzione morfologica dell'alveo pluricursale a isole verso il monocursale. il torrente orco si origina nelle alpi graie piemontesi dalle pendici della becca di moncorvè (3865 m s.l.m.) e sbocca nel fiume po presso chivasso (provincia di torino) a quota 177 m s.l.m., dopo un percorso di 83 km. drena una superficie di 906 km2, di cui 617 km2 in territorio montano, con 1,75% di aree glaciali (mi n istero ll.pp., 1980), chiuso alla stazione idrometrica di pont canavese a quota 430 m s.l.m. (ministero ll.pp., 1925). a partire dal suo sbocco in pianura fino alla confluenza in po (36 km di lunghezza) il torrente attraversa inizialmente un conoide fluvioglaciale e, negli ultimi chilometri, la pianura padana. nella prima metà circa del suo percorso in pianura l'alveo risulta semiconfinato per la presenza del terrazzo insommergibile (alto da 30 m a 15 m e inciso nel conoide fluvioglaciale), che ne contrasta la mobilità verso la destra idrografica. il tratto fluviale, preso a campione per analisi morfometriche nel periodo 1881-2003, si riferisce alla parte medioinferiore del percorso di pianura, per una lunghezza di 25 km. il fiume trebbia nasce nell'appennino ligure, alle pendici del monte prelà (1406 m s.l.m.) in provincia di genova e sfocia nel fiume po, a ovest di piacenza, dopo aver percorso circa 120 km. il suo bacino ha una superficie di 1070 km2, di cui l '85% in ambito collinare/montano. la quota massima del bacino si raggiunge al monte maggiorasca (1799 m s.l.m.) in corrispondenza dello sparfig. 1 ubicazione dei casi di studio. location of study cases. tab. 1 principali caratteristiche dei corsi d'acqua indagati. main characteristics of investigated rivers. tiacque orientale del torrente aveto, maggior affluente del fiume trebbia. il tratto montano, lungo circa 95 km, si presenta prevalentemente incassato e profondamente inciso nel substrato roccioso. il tratto di pianura, compreso tra rivergaro e il po e lungo 22 km circa, scorre su un ampio conoide terrazzato. l'alveo pluricursale sul quale sono state eseguite le misure morfometriche per il periodo 1877-2006 si estende anche nell'ampio fondovalle a monte dello sbocco in pianura (fino al ponte di travo) per una lunghezza complessiva di 31 km. 3. materiali e metodi l'assetto morfologico degli alvei indagati lungo i tratti rappresentativi del modellamento pluricursale è stato ricavato dall'analisi delle situazioni idrografiche riconosciute su: cartografia storica in scala 1:25.000 (tavolette igm datate 1881 per stura di lanzo, 1881 e 1923 per orco, 1877 per trebbia); riprese aeree in visione stereoscopica, con scale medie comprese tra 1:33.000 e 1:10.000 (stura di lanzo), 1:45.000 e 1:5.000 (orco), 1:35.000 e 1:7.500 (trebbia). le riprese sono state eseguite a partire dal 1945 (orco) e dal 1954 (stura di lanzo e trebbia), corrispondenti ai voli con scala minore; i voli successivi sono datati 1975, 1989, 2000 e 2003 per stura di lanzo; 1954, 1961, 1975, 1989, 1999 e 2003 per orco; 1976, 1980, 1990, 1996, 2000, 2002, 2003 e 2006 per trebbia. rilevamenti di campo sono stati inoltre condotti nel 1975, 1985 e dal 2004 al 2007. da ciascun documento cartografico ed aerofotografico è stato estratto l'alveo totale (total channel i n th o r n e, 1997, pag. 204), considerato come l'insieme dei canali occupati dalle acque basse, delle barre e delle isole, elementi fluviali descrittivi della configurazione idrografica pluricursale, espressa attraverso i parametri di larghezza e lunghezza dell'alveo. le configurazioni idrografiche di orco (9 casi) e trebbia (10 casi) sono state georiferite con l'ausilio di applicativi gis (geographical information system) utilizzando come base la carta tecnica regionale (ctr) del piemonte e dell'emilia-romagna in scala 1:10.000. la larghezza dell'alveo è stata misurata lungo sezioni tracciate perpendicolarmente all'asse fluviale, con spaziatura di 100 m per orco e 25 m per trebbia. in particolare, relativamente a trebbia, le sezioni sono state generate automaticamente da un asse fluviale ottenuto a partire dalla somma delle aree occupate dagli alvei nei vari anni considerati. tale area, dopo essere stata rasterizzata, è stata sottoposta ad un'operazione di “assottigliamento” (thinning) e successiva vettorializzazione, fino a definire l'asse (fig. 3). in riferimento al grado di precisione ottenuto con queste tecniche di misura, si è valutato un margine di errore contenuto entro 20 m, in accordo con quanto riportato in letteratura (do w n w a r d et al., 1994; wi n t e rb o t t o m, 2000; li é b a u l t & pi é g a y, 2001; ri n a l d i, 2003; hughes et al, 2006). tale margine di errore è stato ritenuto accettabile a fronte di larghezze dell'ordine delle centinaia di metri. per stura di lanzo le diverse configurazioni idrografiche (6 casi) sono state misurate con sistema elettronico di digitalizzazione planimetrica, che ha permesso di convertire il disegno da un supporto cartaceo (sulla base della ctr del piemonte) ad una successione di coordinate comprensibili dall'elaboratore per lo sviluppo di misure automatiche. le misure di larghezza sono state quindi ricavate con il metodo area/lunghezza, organizzando sei segmenti di alveo, definiti in progressione da monte verso valle lungo il tratto campione di 10,5 km. con questa procedura di misurazione, l'errore è comunque da ritenersi contenuto entro i 25 m, accettabile per larghezze medie rilevate su ciascun segmento, comprese tra 100 e 800 metri, e riferite alle aree di alveo totale tra 0,053 km2 e 1,850 km2. 254 fig. 2 il fiume stura di lanzo nel tratto campione esaminato per l'evoluzione morfologica dell'alveo pluricursale, a testimonianza del periodo di maggiore restringimento dell'alveo (1954-1989). legenda: 1) sbocco del fiume dal bacino montano; 2) settore di massima espansione nel 1954; 2-3) alveo in transizione verso il monocursale (1989). nord verso l'alto. the channel reach studied to represent the morphological evolution of the multi thread system in stura di lanzo river. legend: 1) mouth from the mountain basin; 2) sector of maximum channel enlargement in 1954; 2-3) transitional channel towards a single thread system (1989). north towards up. l. pellegrini et al. per quanto attiene alle variazioni del parametro lunghezza dell'asse fluviale, per i tre casi indagati non sono stati ritenuti significativi valori inferiori a 20 m (talora riscontrati in stura e trebbia). con i rilevamenti di campo sono state condotte verifiche ed integrazioni relative alle modificazioni morfologiche più recenti (naturali e antropiche) soprattutto per l'individuazione plano-altimetrica speditiva delle forme fluviali di alveo attivo e non attivo e ai processi di incisione (go v i, 1976), valutati anche con rilievo topografico in stura di lanzo (godone et al., 2004). 4. risultati per ciascun corso d'acqua indagato è stato possibile ricostruire le vicende evolutive dell'assetto morfologico dell'alveo, a partire dalla configurazione planimetrica di fine '800 fino alla situazione attuale, ponendone in evidenza le tappe fondamentali e le forme descrittive dei cambiamenti, espresse dai valori misurati di larghezza dell'alveo e lunghezza dell'asse corrispondente, con indicazioni locali anche del grado di abbassamento. 4.1 fiume stura di lanzo nel tratto campione di corso d'acqua pluricursale, con lunghezza pari a 10,5 km nel 1881, misurato dallo sbocco montano, sul periodo di osservazione dal 1881 al 1989 è stata registrata una fase di importante restringimento, più veloce dopo gli anni cinquanta, durante la quale la larghezza media dello sviluppo pluricursale risulta ridotta quasi dell '80%. successivamente, negl i anni novanta si sono susseguite le piene del settembre 1993 e del novembre 1994, che hanno ridimensionato l'alveo aumentandone la larghezza. le maggiori evidenze di ripresa dello spazio fluviale in larghezza sono state misurate in occasione dell'ultimo evento di piena, riconosciuto quale il massimo storico (1920-2007) e manifestatosi nell'ottobre 2000 con la portata di 2000 m3/s su una media annuale di 20 m3/s (1930-1980), valori ricavati dalla stazione di lanzo torinese, sita alla chiusura del bacino montano. la ripresa di larghezza sembra, tuttavia, specificatamente associata alla morfodinamica della piena stessa: infatti, sulle fotografie aeree del 2003 già è manifesto un leggero restringimento delle dimensioni dell'alveo, dovuto all'evoluzione di alcune barre fluviali in piana inondabile incipiente, evoluzione documentata anche dalle successive osservazioni di campo. gli aggiustamenti morfologici del modellamento pluricursale si riferiscono alla sequenza temporale delle larghezze medie dell'alveo, misurate per gli anni 1881, 1954, 1975, 1989, 2000 e 2003 (fig. 4). tali aggiustamenti mettono in evidenza che il fiume sta manifestando, dopo il 1989, forme conservative di modellamento pluricursale ad isole verso monte (settore 1-2, anni 2000 e 2003), mentre lo sta abbandonando definitivamente verso valle (settore 2-3, anni 2000 e 2003), in corrispondenza degli affioramenti di un substrato di sedimenti fini prefluviali attribuit i al “villafranchiano” (cerchio et al., 1990), dove il fiume ha inciso un canale principale, unico. la dinamica di incisione in tale settore è in atto, con valore di abbassamento valutato in 5 m dal 1954 al 255 fig. 3 per quanto attiene al fiume trebbia le misurazioni di larghezza dell'alveo sono state eseguite su tracce di sezione generate automaticamente, a partire dall'asse fluviale (linea tratteggiata), calcolato tramite “assottigliamento” dell'area occupata dagli alvei nel periodo esaminato. concerning trebbia river, measurements on river-bed width were performed using automatically generated cross sections, beginning from fluvial axis (dashed line), calculated by ”thinning” of river-bed areas in the examined period. fig. 4 diagramma dell'evoluzione delle larghezze medie dell'alveo, espressa in funzione delle distanze dallo sbocco in pianura per gli anni 1881, 1954, 1975, 1989, 2000 e 2003, nel tratto campione del fiume stura di lanzo (10,5 km): 1, 2, 3 siti di corrispondenza con fig. 2. le larghezze minori sono riportate a valle del km 6 dopo il 1954 e sono riferiti all'alveo di transizione verso il monocursale (2-3 in fig. 2). evolutionary graph of the mean channel widths in 1881, 1954, 1975, 1989, 2000 and 2003, as related to the downstream distances from the mouth in the plain in the sample reach of the stura di lanzo river (10,5 km): 1, 2, 3 corresponding sites in fig. 2. smaller widths are related downstream to the distance of km 6, after 1954, corresponding to the transitional channel towards a single thread system (2-3 in fig. 2). evoluzione morfologica di alvei ... 2004 (go d o n e et al., 2004), nel contesto comunque di un generale abbassamento dell'alveo già rilevato lungo tutto il percorso di pianura, variabile da 2 a 5 m per il periodo 1936-1975 (go v i, 1976). l'incisione è dovuta alla stabilizzazione di un sistema di deflusso monocursale, mantenuto anche in occasione della piena del 2000, che si ritiene qui irreversibile a parità di future condizioni sedimentarie di trasporto (fig. 5). le lunghezze dell'asse fluviale non hanno subito variazioni significative. 4.2 torrente orco nel tratto di pianura indagato (25 km) il corso d'acqua ha mostrato durante il xix secolo un aspetto a prevalenza pluricursale, con forme e numero di ramificazioni variabili nello spazio e nel tempo; la massima espansione del sistema a più canali di deflusso ha toccato nel 1881 e ancora nel 1954 valori intorno a 800 m in corrispondenza del settore centrale. la graduale semplificazione dell'assetto planimetrico, percepita da fine '800, proseguita fino a metà '900 (fig. 6) e in generale regressione verso monte, ha subito un'accelerazione da metà '900, riducendo in maniera significativa la larghezza dell'alveo (fig. 7). tale processo, accompagnato da abbassamento del fondo valutato più frequentemente in 1÷2 m dal 1961 al 1975, con massimi locali di 3 e 4 m (govi, 1976) si è tradotto a fine anni '70 in una trasformazione dei modelli fluviali originari: l'alveo a più canali di deflusso ha assunto ovunque caratteri di transizione con locali affioramenti del substrato sabbioso-limoso prefluviale a partire dagli anni '80 (fig. 8), mentre l'alveo con forme di transizione si è ridotto ad un unico canale con andamento sinuosomeandriforme. nel 1989 il risultato complessivo di queste variazioni di forma e dimensione ha portato la larghezza media dell'alveo a valori inferiori del 60% rispetto a quelli di fine '800. per contro, a partire da inizio anni '90 si è assistito ad un'inversione di tendenza, con aumento della larghezza d'alveo risultato particolarmente accentuato a seguito delle gravi piene del 1993 e del 2000 (ciascuna delle quali ha superato in portata la massima precedente). infatti, dopo la piena del 2000 il valore di larghezza ha raggiunto un incremento del 133% rispetto al dato del 1989. contemporaneamente al fenomeno di restringimento dell'alveo si è registrato un allungamento del suo asse (+8%); il fenomeno di allargamento dell'alveo è stato invece accompagnato da una riduzione della sua lunghezza (-6%). per questo caso di studio, recenti indagini sugli interventi antropici e sulle piene (tu r i t t o & au d i s i o, 2005) hanno permesso di identificare due ruoli contrastanti nei meccanismi di modellamento fluviale: quello dell'uomo nell'avviare o nell'accelerare il processo di semplificazione dell'assetto planimetrico con interventi risultati estremamente invasivi, come in occasione della costruzione di ponti (tu r i t t o & au d i s i o, 2008); quello delle massime piene nel rimodellare anche radicalmente la configurazione d'alveo, tentando di riproporre le forme pluricursali originarie attraverso ampliamenti di sezione (con locali arretramenti di sponda dell'ordine del centinaio di metri), riattivazione di vecchi rami periferici e formazione di nuove isole (turitto et al., 2008). 4.3 fiume trebbia dalle analisi effettuate lungo il tratto considerato (rinaldi et al., 2005; duci, 2007) è risultato un notevole 256 fig. 5 a) andamento pluricursale del fiume stura di lanzo (vista verso monte circa 6 km dallo sbocco in pianura, 05/04/2007). il sito è rappresentativo della forma pluricursale conservata in un segmento di 2,3 km con larghezza media di 260 m nel 2003. in tale segmento, nel 1954, la larghezza media era di 435 m, ridotta a 145 m nel 1989 (1-2 in fig. 2). b ) andamento monocursale di transizione del fiume stura di lanzo (vista verso monte circa 7 km dallo sbocco in pianura, 01/06/2007). il sito è rappresentativo della forma di trasformazione dell'alveo pluricursale verso un alveo monocursale, per incisione progressiva entro sedimenti fini, prefluviali, messi a giorno dall'erosione sotto i depositi ghiaiosi dell'alveo pluricursale, in un segmento di 4,4 km con larghezza media di 200 m nel 2003. riduzione dell'alveo pluricursale da una larghezza di 450 m nel 1954 a 115 m nel 1989 (2-3 in fig. 2). a) multi thread channel of the stura di lanzo river (upstream view, about 6 km from the mouth, 05/04/2007). the site represents the channel form in a 2.3 km long reach with an average width of 260 m, measured on 2003 aerial photographs. the same reach in 1954 had an average width of 435 m and in 1989 the width reduced to 145 m (1-2 in fig. 2). b) transitional single thread channel of the stura di lanzo river (upstream view about 7 km from the mouth, 01/06/2007). the site represents the channel form changing from a multi thread channel to a single thread channel, due to progressive downcutting within sedimentary rocks exposed by erosion of the gravel deposits, in a 4.4 km long reach with an average width of 200 m, measured on 2003 aerial photographs. narrowing to 115 m in 1989 from 450 m measured in 1954 (2-3 in fig. 2). l. pellegrini et al. restringimento dell'alveo, soprattutto tra il 1877 e il 1990, che ha portato la larghezza massima dai 1670 m del 1877 ai 560 m attuali. tale restringimento è stato accompagnato da un approfondimento dell'alveo (da 2 a 4 m) con conseguente abbandono di porzioni dello stesso, divenute progressivamente piana inondabile e, in seguito, terrazzo. il processo di restringimento e approfondimento ha subito una notevole accelerazione a partire dagli anni '60 del secolo scorso, a seguito di un forte deficit di sedimenti nell'alveo la cui causa viene ricondotta all'importante attività estrattiva (fig. 9) portata avanti nella seconda metà del xx secolo (bezoari et al., 1984). e' stato inoltre osservato che i più significativi restringimenti si sono verificati nei tratti di maggiore ampiezza che caratterizzavano, fino agli ultimi anni '70, l'andamento planimetrico del corso d'acqua (fig. 10). in particolare, sono state rilevate riduzioni della larghezza media (calcolata su tutto il corso d'acqua) del 19% dal 1877 al 1954 e ulteriori riduzioni del 58% dal 1954 al 1990. questo restringimento ha portato il corso d'acqua nel 1990 a dimensioni del 66% inferiori rispetto a quelle del 1877, con un dislivello fra la sommità delle barre attuali e la sommità delle ghiaie appartenenti all'alveo del 1877 spesso dell'ordine di 3÷4 m. i valori sopra menzionati si riferiscono alle variazioni del l'alveo tota le comprensivo del le isole. 257 fig. 6 torrente orco nel settore di monte del tratto indagato. le immagini mostrano la semplificazione del sistema di deflusso al passaggio dalla situazione del 1923 a quella del 1945; sulla ripresa del 1945 alcuni rami secondari appaiono già abbandonati (frecce bianche) mentre altri sono in fase di abbandono (freccia nera). la luce dei due ponti (quello di rivarolo, a monte, costruito nel 1850 e quello di feletto, a valle, costruito nel 1935) è chiaramente troppo esigua rispetto alla naturale larghezza dell'alveo nel sito di attraversamento e i loro lunghi rilevati di accesso invadono e riducono la sezione d'alveo. the orco river in the upper investigated reach. the pictures show the simplification of the river pattern from the 1923 to the 1945 configuration; in the 1945 aerial photograph some secondary branches already appear abandoned (white arrows) or are about to be abandoned (black arrow). the spans of the two bridges (the rivarolo bridge, built upstream in 1850, and the feletto bridge, built downstream in 1935) are clearly too small for the natural channel width at the crossing sites and their long bridge-approaches encroach and reduce the channel cross-section. fig. 7 torrente orco: variazioni di larghezza dell'alveo lungo il tratto indagato (25 km, deflusso verso destra) nel periodo 19542003. orco river: changes in channel width along the investigated reach (25 km, downflow to the right) over the 1954-2003 period. evoluzione morfologica di alvei ... 258 fig. 8 torrente orco nel settore intermedio del tratto indagato. il processo di abbassamento del fondo alveo ha portato all'incisione del materasso alluvionale, raggiungendo i sedimenti fini di depositi lacustri. the orco river in the middle investigated reach. the process of bedlevel lowering incised the alluvial gravel deposits reaching the fine sediments of lacustrine deposits. fig. 9 tratto del fiume trebbia immediatamente a valle del ponte di tuna (16 km circa a monte della foce in po). l'immagine, che si riferisce al volo 1980, mostra quanto sia diffusa e invasiva l'attività estrattiva in alveo. trebbia river downstream of tuna bridge (16 km upstream to the confluence in the po). in the aerial photo (1980) we can see the widespread gravel-mining activity in the riverbed. l. pellegrini et al. tato un abbassamento del fondo dei canali con restringimento dell'alveo e prolungata emersione di porzioni fluviali col tempo divenute isole. attualmente è possibile osservare un'inversione della tendenza precedente con un allargamento dell'alveo totale del 15% tra il 1990 e il 2006. nello stesso periodo questo fenomeno è stato accompagnato da un generalizzato smantellamento delle isole che ha prodotto un incremento del 29% dell'alveo attivo. la recente tendenza all'allargamento è evidente soprattutto nel tratto medio inferiore di 17 chilometri dalla foce in po. in questo tratto il fiume trebbia mostra una spiccata tendenza all'erosione laterale (in alcuni punti si sono verificati arretramenti dell'ordine del centinaio di metri), che porta a far riconquistare al corso d'acqua porzioni d'alveo perse nei decenni passati. sembra opportuno precisare, inoltre, che la suddetta erosione laterale si esplica prevalentemente in sponda destra. qui il corso d'acqua, oltre ad aver nuovamente occupato gli spazi persi, è andato ad interessare aree non precedentemente segnalate come facenti parte dell'alveo. al recente allargamento si è associata una marcata attività deposizionale, che ha indotto negli ultimi anni un innalzamento del fondo dell'alveo. questa indicazione viene fornita dal confronto dei profili longitudinali e confermata dalle evidenze morfologiche riscontrate sul terreno. in riferimento alla lunghezza dell'asse fluviale, incrementi e decrementi sono risultati molto ridotti. 5. evoluzione a confronto le informazioni acquisite e i dati elaborati hanno permesso di operare confronti tra i tre corsi d'acqua, da cui sono emerse indiscutibili analogie evolutive del sistema pluricursale, pur con le specifiche differenze dei valori dei parametri misurati nei singoli casi. per i tratti rappresentativi di stura di lanzo, orco e trebbia gli aggiustamenti morfologici degli alvei totali, definiti dalle variazioni di larghezza media del modellamento pluricursale nella sua evoluzione temporale e dalle corrispondenti variazioni di lunghezza degli assi fluviali, sono riportati di seguito, in diagrammi e figure di confronto. 5.1 variazioni nei valori di larghezza dal grafico di figura 11a appare evidente che, in differente contesto geografico/morfologico (orientazione e superficie dei bacini, lunghezza dei tratti indagati), ambito geolitologico (rocce cristalline o carbonatiche nel bacino montano di pertinenza) e ambiente idrologi259 fig. 10 larghezze medie dell'alveo del fiume trebbia negli anni 1877, 1954, 1976, 1980, 1990, 2006, in relazione alla progressiva metrica dalla foce in po (0 m) fino a travo (31.000 m). per motivi grafici sono stati riportati soltanto i valori relativi alle annate maggiormente significative, escludendo le misurazioni corrispondenti al 1996, 2000, 2002, 2003. si noti come le variazioni più rilevanti, in termini di restringimento, siano collocate in corrispondenza dei tratti più ampi situati tra le progressive 4.500 e 15.000 m. widths of trebbia river channel from mouth (0 m) to travo (31.000 m) measured in 1877, 1954, 1976, 1980, 1990, 2006. for graphical simplification, only significant years were reported, excluding 1996, 2000, 2002, 2003. the most intense narrowing occurred in the over-wide reaches (from 4.500 to 15.000 m). fig. 11 variazioni temporali delle larghezze medie d'alveo (a) e delle corrispondenti lunghezze dell'asse fluviale (b), rilevate a confronto per il fiume stura di lanzo, torrente orco e fiume trebbia nel periodo considerato di 150 anni circa (dal 1877 al 2006). temporal trend comparison of average channel width (a) and length (b) of stura di lanzo, orco and trebbia rivers over the 1877-2006 period. escludendo invece dalla misura la parte occupata dalle isole e prendendo in considerazione la sola larghezza dell'alveo attivo (formato solo da canali di deflusso e barre), le variazioni risultano più accentuate. infatti, negli anni contraddistinti da minore larghezza, la superficie occupata dalle isole è stata massima, a scapito delle aree di deflusso. tali modificazioni d'alveo derivano dalla ripresa dell'erosione verticale che ha comporevoluzione morfologica di alvei ... co (precipitazioni e portate), per i tre corsi d'acqua le larghezze medie degli alvei diminuiscono progressivamente nei primi 70 anni. infatti, dalla configurazione del xix secolo a quella dell'anno 1954 emerge un restringimento del 36% in stura di lanzo, 33% in orco, e 19% in trebbia, a partire da valori medi iniziali rispettivamente di 500, 300 e 600 metri. dalle situazioni del 1954 fino a quelle degli anni 1989/1990 (circa 35 anni, la metà del periodo precedente), la diminuzione di larghezza assume un andamento più accelerato contemporaneamente per i tre casi, toccando valori di restringimento pari a 68% in stura di lanzo, 44% in orco e 58% in trebbia (fig. 12). con gli anni '90 del secolo scorso ciascun corso d'acqua ha invece fatto registrare un'inversione di tendenza con aumento di larghezza dell'alveo che, in poco più di 10 anni, è risultato notevole per stura con +98% al 2000 (fig. 13), eccezionale per orco con +133% al 260 fig. 12 all'altezza di gragnano-case di trebbia (10 km circa a monte della foce in po) il confronto tra le riprese del 1954 (a sinistra) e del 2006 (a destra) evidenzia, oltre alla riduzione di larghezza dell'alveo (sottolineata dal tratteggio), la variazione di configurazione d'alveo che da pluricursale diviene monocursale a barre alternate (alta sinuosità). a quest'ultima configurazione si associano palesi processi di erosione in corrispondenza delle sponde concave delle anse. the trebbia river near gragnano-case trebbia (about 10 km upstream to the confluence in the po). the comparison between the 1954 (on the left) and 2006 (on the right) aerial photographs shows the channel narrowing and the pattern variation, which, from braided, becomes single-thread with alternated bars. bank erosion occurs in this last configuration. fig. 13 particolarità degli effetti della piena dell'ottobre 2000 in stura di lanzo sull'allargamento del sistema pluricursale con isola. a sinistra: situazione 1973 con isola in fase di congiunzione con la piana, per abbandono del ramo laterale sinistro (circa 3 km dallo sbocco del fiume in pianura, deflusso verso destra). a destra: riconfigurazione 2000 dell'isola per riattivazione del ramo laterale sinistro. widening flood effects in stura di lanzo river due to the 2000 large flood in the multi-thread channel and island. left: 1973 reduced water flow in the left old channel surrounding an island that is joined to the plain (about 3 km from the river mouth in the plain, river flows towards the right). right: new configuration in 2000 due to the reactivation of the left channel. l. pellegrini et al. 2003 (raggiungendo valori prossimi a quelli di inizio '900) e moderato per trebbia con +15% al 2006. in riferimento all'evoluzione attuale va segnalato che misure di larghezza dell'alveo eseguite sui corsi d'acqua piemontesi, a pochi anni di distanza dalla massima piena storica dell'ottobre 2000 (dopo tre anni su stura e dopo sei anni su un sottotratto campione di orco) hanno fatto registrare valori che indicano un rinnovato, seppur contenuto, processo di restringimento dell'alveo. 5.2 variazioni nei valori di lunghezza dal grafico di figura 11b emerge che, nonostante un diverso andamento delle curve in ciascun corso d'acqua indagato, il maggior valore di lunghezza dell'asse fluviale risulta quello riferito agli anni 1989/1990. rispetto ai dati del 1877/1881, l'incremento è stato rilevato ovunque e con maggiore entità per orco (+8%). l'allungamento dell'asse fluviale è giustificato dalla variazione geometrica di distribuzione delle acque dall'alveo pluricursale verso un alveo monocursale, concentrata lungo un ramo preferenziale di deflusso con andamento sinuoso, che ha generato erosioni ed avanzamenti laterali di sponda. ciò ha prodotto una modificazione dell'andamento dei limiti dell'alveo totale entro un percorso ad anse, una conseguente variazione planimetrica dell'asse fluviale e, quindi, della sua lunghezza. infatti, in questo processo evolutivo, ben rappresentato in orco (fig. 14, 1954 e 1975), il ramo dominante si è trovato a prevalere rispetto alle altre ramificazioni secondarie, non più connesse al canale principale per fenomeni di abbassamento del suo fondo e per 261 fig. 14 torrente orco nel settore intermedio del tratto indagato. le fotografie aeree del 1954 e del 1975 mostrano la trasformazione del modello fluviale verso forme ad unico canale di deflusso, con restringimento dell'alveo totale ed allungamento del suo asse mediano. l'immagine del 2003 documenta le modificazioni di forma e dimensione dell'alveo prodotte dalla piena del 2000, che ha riproposto un modello fluviale analogo a quello del 1954. the orco river in the middle investigated reach. the 1954 and 1975 aerial photographs show the pattern transformation towards the single-thread configuration, with total channel narrowing and lengthening. the 2003 picture shows the variation of planimetrical forms and dimensions induced by the 2000 flood, similar to those of 1954. evoluzione morfologica di alvei ... mancanza di piene con livelli tali da mantenerle ricorrentemente attive, escludendo porzioni di alveo dal modellamento fluviale. pertanto, gli anni che presentano i valori maggiori di lunghezza coincidono con gli anni del maggior restringimento. in corrispondenza dell'inversione di tendenza caratterizzata dalla morfogenesi di allargamento degli alvei, avvenuta dopo gli anni 1989/1990 e preceduta da un lungo periodo di restringimento, si rileva anche una riduzione di lunghezza degli alvei, particolarmente significativa in orco (-6,%). tale risultato è la conseguenza diretta dell'espansione dell'alveo associata ad una più o meno evidente rettifica del suo asse fluviale (fig. 14, 1975 e 2003). 6. discussione l'attività di ricerca condotta sull'evoluzione morfologica dei corsi d'acqua stura di lanzo, orco e trebbia, appartenenti al settore occidentale del bacino padano e rappresentativi del sistema pluricursale, ha posto in evidenza i principali cambiamenti di forma e dimensione intervenuti sulla scala temporale degli ultimi 150 anni. in essi è stata riscontrata una generale riduzione di sviluppo longitudinale dell'alveo con caratteri pluricursali, in regressione verso monte, a partire dalle confluenze in po. per stura di lanzo tale regressione è risultata particolarmente accentuata con una perdita del 65% di sviluppo longitudinale dell'originario pluricursale di pianura osservato nel 1881. misurati per i tre corsi d'acqua i parametri morfologici larghezza e lunghezza dell'alveo totale nei tratti indagati e messe successivamente a confronto nel tempo le loro sequenze evolutive, ne è emersa contemporaneità e analogia di variazioni, quindi di tendenza. gli anni in cui compaiono queste variazioni consentono di suddividere l'intervallo di tempo considerato in tre distinti periodi in cui le differenti espressioni evolutive (tipo di variazione ed intensità del processo) sono associate anche a diversi contesti socio-economici e a possibili cause. se ne illustrano qui di seguito gli aspetti salienti. a) il primo periodo (dal 1877 al 1954) è caratterizzato da un fenomeno di riduzione della larghezza media dell'alveo pluricursale contenuto entro valori variabili tra -19% in trebbia e -36% in stura di lanzo. in riferimento al parametro lunghezza, l'ampio alveo di trebbia ha mantenuto un valore costante, quello di stura di lanzo ha fatto registrare un lieve allungamento, mentre quello di orco appare in progressiva crescita. in merito alle possibili cause si fa rilevare che, pur non potendo escludere che queste variazioni fossero inizialmente collocate in un contesto evolutivo naturale, sicuramente l'uomo le ha favorite e indirizzate per acquisire spazi fluviali ad uso antropico. infatti è documentata, quantomeno per stura e orco, la fruizione di rami secondari più esterni per irrigazione o per produzione di forza motrice. ricade in questi anni anche la costruzione delle prime importanti opere viarie, dei primi interventi di sistemazione idraulica a cura del genio civile e dell'avvio dell'escavazione di inerti, con occupazione ed alterazione, ancora circoscritte, degli spazi fluviali. b) il secondo periodo (dal 1954 al 1990) è contraddistinto da accelerazione del processo evolutivo precedente con più rapida riduzione dei valori medi di larghezza, minore per orco (-44%), più accentuato per trebbia (-58%) e soprattutto per stura (-68%). i dati di lunghezza non variano in modo significativo per stura e trebbia, mentre crescono ancora per orco. il comune aspetto saliente è la contemporaneità del minimo valore di larghezza e del massimo valore di lunghezza al passaggio dagli anni ottanta agli anni novanta, che segna la fine del secondo periodo e corrisponde all'esaurimento delle riduzioni di larghezza. a differenza di quanto segnalato per il periodo precedente in merito alle possibili cause, si sottolinea che, proprio a partire dagli anni '50, l'intervento dell'uomo nelle sue varie forme è stato estremamente invasivo ed ha portato ad una drastica rottura degli equilibri originari. ne è derivata la brusca accelerazione della riduzione di larghezza degli alvei, favorita da processi di abbassamento del loro fondo, con palesi ripercussioni negative sull'assetto ambientale del territorio: sottoescavazione delle pile dei ponti e delle difese di sponda, inofficiosità delle opere di derivazione, abbassamento dei livelli di falda, locale messa a giorno di corpi sedimentari prefluviali, con trasformazione morfologica dell'alveo pluricursale verso forme monocursali. questo secondo periodo corrisponde ai tempi della grande ricostruzione post bellica e della successiva intensa antropizzazione per il diffuso sviluppo abitativo, viario e industriale, che hanno comportato sia una notevole richiesta di inerti, sia locali artificializzazioni degli alvei. c) il terzo periodo (successivo al 1990) fa registrare un'inversione di tendenza con fenomeni di allargamento d'alveo, anche se con valori differenti per i tre corsi d'acqua (+15% in trebbia, +98% in stura e +133% in orco), e di riduzione della sua lunghezza. questo terzo e più breve periodo si caratterizza per la maggior sensibilizzazione ai problemi del territorio da parte della comunità e dei servizi tecnici locali e nazionali, tradotta recentemente in riscontri normativi (autorità di bacino del fi u m e po, 1999; 2005). in particolare, le restrizioni imposte sulle modalità di estrazione di inerti (autorità di bacino del fiume po, 1998) con pressoché totale azzeramento della loro asportazione dal letto dei corsi d'acqua hanno portato ad una rinnovata, seppur non quantificata, disponibilità di sedimenti in alveo, che ha garantito per stura, orco e trebbia un più naturale equilibrio tra portate liquide e carico solido per il modellamento pluricursale. infatti, l'adeguamento morfo-dinamico al nuovo equilibrio ha favorito la riconfigurazione dell'alveo, recuperando parte degli spazi fluviali abbandonati o sottratti nel passato, oppure acquisendone di nuovi attraverso l'erosione laterale. nel caso di stura di lanzo e di orco, in aggiunta, il manifestarsi di un evento di piena, quello dell'ottobre 2000, il massimo conosciuto degli ultimi 80 anni, ha reso immediati e più evidenti questi effetti morfologici. in trebbia non sono stati riscontrati effetti così 262 l. pellegrini et al. repentini ed intensi per mancanza di episodi di piena con analoghe caratteristiche estreme. per quest'ultimo corso d'acqua, pertanto, il fenomeno di allargamento dell'alveo è essenzialmente imputabile alla drastica riduzione di prelievo di inerti. inoltre, lungo l'orco gli effetti del rimodellamento dovuto alla piena del 2000 sono apparsi particolarmente esaltati con più marcato aumento di larghezza dell'alveo, associato a riduzione della sua lunghezza. si ritiene che tale effetto possa essere in buona parte dovuto al minor abbassamento medio di fondo subito da questo corso d'acqua negli anni di massimo restringimento del suo letto. occorre tuttavia sottolineare che, comunque, nei tre corsi d'acqua considerati, dopo il 2000 le larghezze d'alveo misurate risultano stazionarie e persino in debole diminuzione su stura e orco, quantomeno a carattere locale. ciò induce a considerare, almeno per i corsi d'acqua piemontesi, un ulteriore quarto periodo caratterizzato da variazioni tendenti a riaggiustare forma e dimensione dell'alveo, su larghezze più contenute rispetto a quelle modellate dalla piena del 2000. 7. conclusioni sulla base dei dati messi a confronto per i corsi d'acqua stura di lanzo, orco e trebbia (bacino padano occidentale), è stato possibile individuare tre ben definiti e contemporanei periodi di evoluzione del sistema fluviale a canali multipli (pluricursale): il primo si colloca tra fine ottocento e metà novecento ed è caratterizzato da restringimento dell'alveo; il secondo è compreso tra metà novecento e fine anni ottanta ed è contrassegnato da accelerazione del processo di restringimento; il terzo prende avvio nei primi anni novanta e si manifesta con un allargamento dell'alveo, introducendo dunque un'inversione di tendenza. i primi due periodi, caratterizzati da diverso grado di restringimento (fine '800-1954 e 1954-1990), corrispondono, a grandi linee, ai due intervalli di tempo (1850-1950 e 1950-1970) in cui è stato riscontrato prima un graduale, poi un rapido restringimento dell'alveo anche lungo numerosi corsi d'acqua del versante alpino francese (liébault & piégay, 2002). inoltre in relazione ai tre periodi individuati per i corsi d'acqua indagati di cui il più recente si riferisce all'inversione di tendenza dal restringimento all'allargamento dell'alveo analoghe e contemporanee modificazioni sono state riscontrate lungo corsi d'acqua con tipologia pluricursale presenti nel terr i tor io del triveneto, afferente al settore orientale dell'arco alpino (surian, 2006). ancora, gli stessi tre periodi trovano buona corrispondenza nelle tre “fasi” definite rispettivamente di “restringimento e incisione parziale”, “restringimento e incisione più intensi”, “inversione di tendenza e parziale recupero”, riconosciute per alvei fluviali della rete idrografica che compete all'appennino centro-settentrionale (rinaldi et al., 2008). dall'insieme di queste diffuse, molteplici e concordanti situazioni di cambiamento fluviale sembrano dunque profilarsi circostanze evolutive comuni in molti corsi d'acqua afferenti a sistemi idrografici dell'arco alpino e dell'arco appenninico. la successione dei cambiamenti di forma e dimensione del modello d'alveo pluricursale, appare chiaramente manifestata per tappe contemporanee e cronologicamente distinte, che ne hanno scandito il processo evolutivo degli ultimi 150 anni con risposta morfologica conforme a scala regionale. ringraziamenti pubblicazione finanziata con fondi del progetto miur-prin 2005, unità di ricerca di pavia (responsabile scientifico luisa pe l l e g r i n i) “dinamica recente ed attuale di alvei fluviali nel settore occidentale del sistema padano: tendenze evolutive, cause ed implicazioni applicative” (prot. 2005044240_002); coordinatore nazionale nicola surian dell'università di padova. indagini ed elaborazioni a cura di pe l l e g r i n i e duci per il fiume trebbia, maraga per il fiume stura di lanzo (con la col laborazione di g. ri v e l l i e c . pelissero), turitto e audisio per il torrente orco. si ringraziano i revisori del testo per le precise osservazioni e gli utili suggerimenti. i fotogrammi a corredo del testo sono resi liberi per gli usi consentiti dalla legge (d.p.r. 367 del 29.09.2000). bibliografia autorità di bacino del fi u m e po (1998) direttiva in materia di attività estrattive nelle aree fluviali del bacino del po allegato 4 al “piano stralcio delle fasce fluviali”, parma, 5 pp. autorità di bacino del fiume po (1999) direttiva “criteri per la valutazione della compatibilità idraulica delle infrastrutture pubbliche e di interesse pubblico all'interno delle fasce a e b” art. 15 delle norme di attuazione del piano stralcio delle fasce fluviali, parma, 43 pp. autorità di bacino del fi u m e po (2005) p r o g r a m m a generale di gestione dei sedimenti alluvionali dell'alveo del fiume po-stralcio confluenza tanaro confluenza arda parma, 127 pp. bezoari g., braga g., gervasoni s., larcan e. & paoletti a. (1984) effetto dell'estrazione di inerti sull'evoluzione dell'alveo del fiume trebbia 2° conv. idraulica padana. parma, 15-16 giugno 1984, pp. 163-182. canuti p., cencetti c., conversini p., rinaldi m. & tacconi p. (1992) dinamica fluviale recente di alcuni tratti dei fiumi arno e tevere atti del convegno “fenomeni di erosione e alluvionamenti degli alvei fluviali”, università di ancona, 14-15 ottobre 1991, pp. 21-35. ca s t i g l i o n i g.b. & pe l l e g r i n i g.b. (1981) g e o m o rfologia dell'alveo del brenta nella pianura tra bassano e padova in: zunica m. (ed.) il territorio della brenta, amministrazione provinciale di padova e università di padova, pp. 12-32. ce r c h i o e., coccolini g.b.l., fo r n e l l i a., fo z z a t i l. & tropeano d. (1990) per una archeologia forestale in piemonte. il giacimento “villafranchiano” della stura di lanzo quaderni della soprintendenza 263evoluzione morfologica di alvei ... archeologica del piemonte, pp. 1-25. co l t o r t i m., na n n i t. & vi v a l d a p. (1992) la bassa valle del fiume musone (marche): geomorfologia e fattori antropici nell'evoluzione della pianura alluvionale geografia fisica e dinamica quaternaria, 14, pp. 101-111. downward s.r., gurnell a.m. & brookes a. (1994) a methodology for quantifying river channel planform change using gis iahs publ. 224, pp. 449-456. du c i g. (2007) analisi delle variazioni morfologiche recenti dell'alveo del f. trebbia da perino alla foce. metodi d' indagine tesi di laurea specialistica in scienze geologiche applicate. università di pavia, 217 pp., 7 tav.f.t. dutto f. & maraga f. (1991) valutazione dei sedimenti mobilizzati nel periodo 1955-1988 lungo le sponde del fiume po cnr-irpi, torino, rapporto interno mi/91.1, 24 pp. dutto f. & maraga f. (1994) variazioni idrografiche e condizionamento antropico. esempi in pianura padana il quaternario, 7(1), pp. 381-390. franceschetti b., stoppato m. & turitto o. (1990) le modificazioni del corso della dora riparia tra susa e alpignano dal 1881 al 1977. fattori naturali e antropici e riflessi ambientali rivista geografica italiana, xcvii(4), pp. 475-505. godone f., baldo m. & maraga f. (2004) una foresta nell'alveo del f. stura di lanzo (to): rilevamenti topografici, cartografia e gis atti 8a conferenza nazionale asita, roma 14-17 dicembre 2004, pp. 1219-1224. go v i m. (1976) ricerche sui processi di riattivazione delle capacità erosive negli alvei dei torrenti stura di lanzo e orco la ricerca scientifica, 46(2), pp. 332-334. govi m. & turitto o. (1993) processi di dinamica fluviale lungo l'asta del po acqua aria, 6, pp. 575588. ha b e r s a c k h., pi é g a y h. & ri n a l d i m. (eds.) (2008) gravel-bed rivers vi. from process understanding to river restoration elsevier b.v., 817 pp. hu g h e s m.l., mcdo w e l l p.f. & ma r c u s w.a. (2006) accuracy assessment of georectified aerial photographs: implication for measuring lateral channel movement in a gis geomorphology, 74, pp. 116. liébault f. & piégay h. (2001) assessment of channel changes due to long-term bedload supply decrease, roubion river, france geomorphology, 3 6, pp. 167-186. liébault f. & piégay h. (2002) causes of 20th century channel narrowing in mountain and piedmont rivers of southeastern france earth surface processes and landforms, 27, pp. 425-444. malavoi j.r., bravard j.p., piegay h., heroin e. & ramez p. (1998) détermination de l'espace de liberté des cours d'eau agence de l'eau-bassin rhône méditerranée corse, guide technique n. 2, lyon, 39 pp. maraga f. (1989) ambiente fluviale in trasformazione: l'alveo-tipo pluricursale verso un nuovo modellamento nell'alta pianura padana proceeding of the international congress on geoengineering “suolosottosuolo”, turin, 27-30 september 1989, 1, pp. 119-128. maraga f. (1992) riduzione del campo di attività fluviale e disponibilità di sedimento nei tratti d'alveo pluricursali: casi di studio nella pianura padana atti “fenomeni di erosione e alluvionamenti degli alvei fluvial i”, ancona 14-15 ottobre 1991, università degli studi di ancona, pp. 51-62. maraga f., masino a. & viola e. (2003) evoluzioni idrografiche del fiume po nel tempo ultrasecolare atti 7a conferenza nazionale asita, verona 28-31 ottobre 2003, pp. 1415-1420. ma r c h e t t i m. (2002) environmental changes in the central po plain (northern italy) due to fluvial modifications and anthropogenic activit ies geomorphology, 44, pp. 361-373. mi n i s t e r o la v o r i pu b b l i c ise r v i z i o id r o g r a f i c ouf f i c i o idrografico del po di pa r m a (1925) s t a t i s t i c a delle aree dei bacini idrografici, volume iii: granamaira-varaita-alto po-pellice-chisone-dora riparia-stura di lanzo-orco parma, 76 pp. mi n i s t e r o la v o r i pu b b l i c ise r v i z i o id r o g r a f i c o (1980) dati caratteristici dei corsi d'acqua italiani roma, 362 pp. pe l l e g r i n i m., pe r e g o s. & ta g l i a v i n i s. (1979) l a situazione morfologica degli alvei affluenti emiliani del po estratto dagli atti del convegno di idraulica padana, parma, 19-20 ottobre 1979, 9 pp. piégay h., darby s.e., mosselman e. & surian n. (2005) a review of techniques available for delimiting the erodible river corridor: a sustainable approach to managing bank erosion river research and applications, 21, pp.773-789. pittaluga f., paita r., mazzali a., cassinelli p., redoano l., gi u n t i n i d. & pa n t e r a l. (2006) il piano stralcio “asetto idrogeologico” del bacino del fiume magra. aspetti innovativi e prospettive future atti giornate di studio “nuovi approcci per la comprensione dei processi fluviali e la gestione dei sedimenti”, autorità di bacino interregionale del fiume magra, sarzana, 24-25 ottobre 2006, pp. 7-22. ramasco m. & rossanigo p. (1988) evoluzione morfologica dell'alveo del t. cervo nel tratto di pianura e studio fotointerpretativo dell'inondazione verificatasi il 2-3 novembre 1968 provincia di vercelli e regione piemonte, 24 pp. rinaldi m. (2003) recent channel adjustment in alluvial rivers of tuscany, central italy earth surface processes and landforms, 28, pp. 587-608. ri n a l d i m. (2006) la prospettiva geomorfologia e le applicazioni nella gestione degli alvei fluviali atti giornate di studio “nuovi approcci per la comprensione dei processi fluviali e la gestione dei sedimenti”, autorità di bacino interregionale del fiume magra, sarzana, 24-25 ottobre 2006, pp. 395 8 . ri n a l d i m., si m o n c i n i c. & so g n i d. (2005) v a r i a z i o n i morfologiche recenti di due alvei ghiaiosi appenninici: il fiume trebbia ed il fiume vara geogr. fis. din. quat., suppl. vii, pp. 313-319. rinaldi m., teruggi l.b., simoncini c. & nardi l. (2008) dinamica recente ed attuale di alvei fluviali: alcuni casi di studio dell'appennino settentrionale in questo volume. ri n a l d i m., wy z g a b. & su r i a n n. (2005) s e d i m e n t 264 l. pellegrini et al. mining in alluvial channels: physical effects and management perspectives river research and applications, 21, pp. 805-828. surian n. (2006) effects of human impact on braided river morphology: examples from northern italy in: sambrook smith g.h., best j.l., bristow c.s. & pe t t s g.e. (eds.). “braided rivers: process, deposits, ecology and management”, blackwel publishing, pp. 327-338. su r i a n n., pe l l e g r i n i g.b. & sc o m a z z o n e. (2005) variazioni morfologiche dell'alveo del fiume brenta indotte da interventi antropici geografia fisica e dinamica quaternaria, suppl. vii, pp. 339-345. surian n. & rinaldi m. (2003) morphological response to river engineering and management in alluvial channels in italy geomorphology, 5 0, pp. 307326. surian n. & rinaldi m. (2004) channel adjustments in response to human alteration of sedimen fluxes: examples from italian rivers proceedings of a symposium “sediment transfer through fluvial system”, moscow, august 2004, iahs pubbl. n. 288, pp. 276-282. thorne c.r. (1997) channel types and morphological c l a s s i f i c a t i o n in: th o r n e c.r., he y r.d. & ne ws o n m.d. (eds.) “applied fluvial geomorphology for river engineering and management”, wiley, chichester, pp. 175-222. turitto o. & audisio c. (2005) analisi dei motivi naturali e antropici all'origine di modificazioni planimetriche riscontrate lungo l'alveo del torrente orco negli ultimi due secoli convenzione tra regione piemonte-direzione difesa del suolo e cnr-irpi di torino nell'ambito del progetto “monitoraggio e manutenzione del fiume orco”, cnr-irpi torino r.i. 05/36, 61 pp. turitto o. & audisio c. (2008) ponti e dinamica fluviale. effetti di reciproca interferenza l'acqua, 2, pp. 7-16. turitto o., audisio c. & agangi a. (2008) il ruolo svolto da piene straordinarie nel rimodellare la geometria di un alveo fluviale in questo volume. wi n t e r b o t t o m s.j. (2000) medium and short-term channel planform changes on the rivers tay and tummel, scotland geomorphology, 34, pp.195208. 265 ms. ricevuto il 21 dicembre 2007 testo definitivo ricevuto il 9 maggio 2008 ms. received: december 21, 2007 final text received: may 9, 2008 evoluzione morfologica di alvei ... imp.meisina& problematiche geologico-tecniche di formazioni superficiali soggette a variazioni di volume claudia meisina1 & laura rolandi1 1dipartimento di scienze della terra, università degli studi di pavia – cmeisina@manhattan.unipv.it riassunto: c. meisina & l. rolandi, problematiche geologico-tecniche di formazione superficiali soggette a variazioni di volume. it issn 0394-3356, 2004. le variazioni di volume dei terreni argillosi (ritiro nei periodi secchi e rigonfiamento in quelli umidi) sono all’origine di numerosi danni a fondazioni di edifici ed infrastrutture (strade). negli ultimi anni i cambiamenti climatici globali hanno determinato il ripetersi di periodi particolarmente siccitosi che hanno amplificato il fenomeno anche nei nostri climi temperati. i terreni argillosi soggetti a variazioni di volume sono costituiti da depositi quaternari, quali i depositi alluvionali e le coltri eluvio-colluviali, spesso indicati con il termine di “formazioni superficiali”. la finalità di questo lavoro è illustrare e discutere le problematiche geologico-tecniche che emergono nello studio delle formazioni superficiali soggette a variazioni di volume. l’area studiata è costituita dal centro urbano di varzi (italia settentrionale, appennino pavese), impostato su depositi alluvionali ed eluvio-colluviali. l’approccio adottato è di tipo multidisciplinare; al fine di ricostruire il modello geologico-tecnico dell’area sono stati raccolti dati riguardanti la geologia, la geomorfologia, l’evoluzione del reticolato idrografico, nonché informazioni storiche relative allo sviluppo urbano del paese di varzi. in una prima fase sono state identificate, tramite fotointerpretazione, le unità morfologiche (terrazzi e conoidi alluvionali, frane, ecc.). nella seconda fase tali unità sono state caratterizzate dal punto di vista litostratigrafico, idrogeologico e geotecnico in modo da definire delle unità morfo-litotecniche omogenee in base a: genesi (alluvionale, di versante, antropica), condizioni topografiche (acclività e drenaggio), litofacies, geometria dei terreni (spessore, variazioni laterali), condizioni idrogeologiche (soggiacenza falda, permeabilità) e geotecniche (potenziale di ritiro-rigonfiamento e spessore della zona attiva). le unità marfo-litotecniche individuate sono state classificate in funzione del loro potenziale di ritiro-rigonfiamento. abstract: c. meisina & l. rolandi, engineering geological problems related to swelling-shrinking superficial deposits. it issn 0394-3356, 2004. the volume changes of clayey soils (shrinking in the drought periods, swelling in the periods of rainfalls) are the cause of many problems in engineered structures. global climatic changes as prolonged period of dry weather, influence soil moisture content and are the primary cause of volume changes of clayey soils in temperate regions. in italy most of these soils are associated with alluvial deposits and eluvial-colluvial soils derived from sedimentary rocks by weathering (superficial deposits). the aim of the work is to underline the engineering geological problems related to the study of the superficial deposits characterized by volume changes. the test site is the urbanized area of the town of varzi (northern italy, pavese appennines) built on the alluvial and eluvial-colluvial deposits. the lithological setting and geotechnical characteristics of these deposits are poorly defined, due to the lack of outcrops and the intrinsic heterogeneity of the sediments. engineering geological mapping was carried out to provide engineering geological information as an aid in planning land use. the adopted approach has been multidisciplinary, such that data regarding the geology, geomorphology, hydrographic network, urban development and history of the town area have been used to develop a geological/geotechnical model of the area. in the first step the landforms (alluvial terraces, landslides, alluvial fans, etc.) were mapped from aerial photographs. in the second step for each landforms the nature of surface materials (lithostratigraphic, hydrogeological and geotechnical characteristics) was determined. the datasets included boreholes, trial pits and penetrometer tests. geotechnical and lithological profiles have been constructed. the geotechnical site investigations had the aim of characterising the soil conditions within each homogeneous zone and consisted of pits with a maximum depth of 3 m for the shallow soil exploration, the soil profile description and the collection of samples in the areas representative of the engineering geological terrain units. in addition to the classical mineralogical and geotechnical tests (index properties and volumetric characteristic determination) the samples were submitted to the methylene blue adsorption test, to the swelling pressure and swell strain tests and to the determination of the suction with the filter paper technique. engineering geological zoning was carried out by assessing main attribute groups: genesis, topographic conditions (slope angle and drainage), lithologies, geometries, hydrogeological (depth to the water table, hydraulic conductivity) and geotechnical characteristics. the area was divided into 13 morpho-engineering geological units (areas that may be regarded as homogeneous from the geomorphological and engineering geological point of view) analyzed in terms of swelling-shrinking susceptibility. . parole chiave: terreni rigonfianti, unità morfo-litotecniche, formazioni superficiali, varzi. keywords: swelling soils, morpho-engineering geological units, superficial deposits, varzi. il quaternario italian journal of quaternary sciences 17(2/2), 2004, 597-612 1. introduzione il termine “terreni argillosi rigonfianti” definisce terreni caratterizzati da variazioni di volume (rigonfiamento e ritiro) dovute a cause naturali (precipitazioni, risalita della falda, ecc.) o antropiche (irrigazioni, rotture di condotte, ecc.). essi fanno parte dei terreni problematici, in quanto sono all’origine di numerosi danni a fondazioni di edifici ed infrastrutture (strade) (mouroux et al., 1988; bell & bruyn, 1997; page, 2003). il potenziale di ritiro-rigonfiamento di un terreno argilloso dipende dal tipo e dalla quantità di minerali argillosi presenti, dalla sua struttura e soprattutto dal suo contenuto in acqua e grado di saturazione (chen, 1988). negli ultimi anni i cambiamenti climatici globali hanno determinato il ripetersi di periodi particolarmente siccitosi che hanno amplificato il fenomeno anche nei nostri climi temperati. le variazioni di volume generalmente si 598 c. meisina & l. rolandi manifestano nello spessore di terreno che costituisce la zona attiva (zona che risente delle variazioni di contenuto d’acqua in risposta alle condizioni climatiche) (bre, 1996). dal punto di vista geotecnico tali terreni vengono definiti come non saturi ed essi sono costituiti da depositi quaternari, quali i depositi alluvionali e le coltri eluvio-colluviali, spesso indicati con il termine di “formazioni superficiali” (mcmillan & powell, 1999). nelle aree appenniniche le coltri eluvio-colluviali, di natura prevalentemente argillosa, ricoprono in modo diffuso i versanti con spessori variabili da pochi decimetri ad alcuni metri, derivano dall’alterazione del substrato ad opera degli agenti atmosferici e dal successivo trasporto ad opera delle acque superficiali e/o della gravità e costituiscono il terreno di fondazione della maggior parte degli edifici. i danni associati alle variazioni di volume delle coltri eluvio-colluviali sottolineano la necessità di identificare e classificare tali terreni, valutando anche la loro pericolosità al ritiro-rigonfiamento ai fini di una corretta pianificazione territoriale, in particolar modo a scala di dettaglio (piani regolatori comunali). il ritiro-rigonfiamento dei terreni argillosi è un fenomeno complesso, il cui studio necessita di un approccio di tipo integrato che si dovrebbe avvalere, oltre che dell’analisi geologica e mineralogica, delle metodologie e dei presupposti teorici propri della meccanica delle terre, anche della conoscenza, propria della geologia del quaternario, dell’ambiente di formazione, del meccanismo deposizionale, e dei caratteri sedimentologici. la finalità di questo lavoro è illustrare e discutere le problematiche geologico-tecniche che emergono nello studio delle formazioni superficiali soggette a variazioni di volume. a tale scopo viene presentato un esempio di redazione di una carta delle unità morfolitotecniche (unità litologiche omogenee dal punto di vista geomorfologico e geologico-tecnico) ai fini della valutazione della pericolosità al ritiro-rigonfiamento dei terreni argillosi in un’area appenninica. l’area studiata è costituita dal centro urbano di varzi (provincia di pavia) situato nella parte meridionale dell’oltrepo pavese (italia settentrionale), nell’alta valle del t. staffora, tributario di destra del f. po. 2. inquadramento geologico dell’area studiata il territorio comunale di varzi, classificato come sismico (zona 2, ordinanza p.c.m. n° 3274 del 20/03/2003), è attraversato dal t. staffora, che in questa zona presenta un andamento ew, parallelo alla linea villalvernia-varzi, struttura tettonica di importanza regionale, definita da studi recenti come un sistema transpressivo destro (cerrina feroni et al., 2002). tale struttura giustappone due “mondi” paleogeograficostrutturali ben differenziabili: l’estrema propaggine orientale del bacino terziario ligure-piemontese a sud, caratterizzata da una relativa tranquillità giaciturale con una successione stratigrafica dall’eocene superiore al miocene inferiore, e l’appennino pavese a nord con successioni sedimentarie discontinue dal cretaceo inferiore al miocene ed intensamente deformate (beatrizzotti et al., 1969) (fig. 1). il fondovalle presenta forme di terrazzamento (terrazzi convergenti e poligenici) e conoidi per lo più fossili dei principali affluenti del t. staffora (il t. reganzo, il rio reponte superiore e inferiore in destra idrografica ed il t. lella in sinistra). la morfologia dei versanti è contrassegnata dalla presenza di numerosi fenomeni franosi di tipo complesso (scivolamenti traslazionali e rotazionali che evolvono in colamenti) (braga et al., 1985). il regime pluviometrico è di tipo appenninico con la presenza di due massimi (novembre e maggio) e minimi stagionali ben marcati che caratterizzano l’anno medio. il centro urbano del comune di varzi, dove si è concentrato lo studio, ha un’estensione di 4,5 km2 e occupa la fascia di fondovalle in destra idrografica del t. staffora terrazzata e modellata prevalentemente nei depositi di tipo alluvionale e di tipo eluvio-colluviale provenienti dagli adiacenti versanti. sul ripiano più alto si è sviluppato il borgo antico, mentre le successive espansioni fino ai tempi più recenti hanno progressivamente occupato anche parte del ripiano inferiore. in sinistra idrografica le forme di terrazzamento sono meno marcate essendo presente un solo terrazzo modellato nelle alluvioni recenti. le coltri eluvio-colluviali si sviluppano sui versanti e ricoprono parzialmente i terrazzi alluvionali. nonostante esse corrispondano al 30 % dell’area studiata sono cartografate solo in parte nella carta geologica ufficiale. nel centro urbano gli interventi antropici hanno comportato notevoli modifiche alla morfologia e all’idrografia dell’area. l’alveo del t. staffora, che in tempi storici (inizio xx secolo) si estendeva fino a ridosso del borgo antico, risulta ora delimitato in sponda destra da opere di difesa (muri e gabbionate) erette in tempi successivi per contrastare i fenomeni di alluvionamento. ciò ha comportato un sensibile restringimento della sua ampiezza negli ultimi 50 anni (meisina, 1998). nelle zone di confluenza di alcuni corsi d’acqua l’urbanizzazione ha portato alla canalizzazione dell’asta terminale, con contestuale riduzione delle sezioni idrauliche (rio reganzo, rio lazzuola). nei rii reponte inferiore e reponte superiore la tombinatura dei corsi d’acqua costituisce un ulteriore elemento critico. il paese è attraversato inoltre da un canale artificiale, il canale lagozzo, costruito alla fine del xiii secolo per alimentare un mulino. 3. metodologia di lavoro l’approccio adottato è di tipo multidisciplinare; al fine di ricostruire il modello geologico-tecnico dell’area sono stati utilizzati dati riguardanti la geologia, la geomorfologia, l’evoluzione del reticolato idrografico ed informazioni storiche sullo sviluppo urbano del paese di varzi. lo studio è stato articolato in due fasi (fig. 2): 1° fase: definizione delle unità morfologiche; 2° fase: definizione di unità geologico-tecniche di dettaglio (unità morfo-litotecniche). nella prima fase sono state identificati, tramite fotointerpretazione, i principali elementi morfologici dell’area sia naturali (terrazzi e conoidi alluvionali, frane) che antropici (scavi, riporti). la consultazione di documenti storici e l’analisi multitemporale di foto aeree hanno permesso inoltre di identificare l’evoluzione del reticolato idrografico. alla fine di tale fase il territorio studiato è stato suddiviso in diverse unità morfologiche. successivamente, nella seconda fase, tali unità sono state caratterizzate dal punto di vista geologicotecnico in modo da definire delle unità morfo-litotecni599problematiche geologico-tecniche ... che, omogenee in base a: genesi (alluvionale, di versante, antropica), condizioni topografiche (acclività e drenaggio), litofacies, geometria dei terreni (spessore, variazioni laterali), condizioni idrogeologiche (soggiacenza falda, condizioni di drenaggio) e geotecniche (potenziale di ritiro-rigonfiamento e spessore della zona fig. 1 carta geologica (beatrizzotti et al., 1969). f: frana; dt: eluvio, colluvio e detriti; a3: alluvioni attuali degli alvei attivi dei corsi d’acqua; a2-1: alluvioni post-glaciali; fl3: fluviale recente; m4-3: arenarie di m. vallassa (tortoniano-serravalliano); m2-1: marne di m. lumello (langhiano – miocene pre-langhiano); m1 c: formazione di castagnola (miocene pre-langhiano); m1-o3: marne di rigoroso (miocene inferiore – oligocene superiore); m1-e3: marne di antognola (miocene pre-langhiano – eocene superiore); o3-e3: arenarie di ranzano (oligocene superiore – eocene superiore); e3-1: marne di m. piano (eocene superiore – eocene inferiore); pc-c7 cs: calcari di m. cassio (paleocene – turoniano); c: complesso caotico; i: complesso indifferenziato; vvl: linea villalvernia-varzi. geological map (beatrizzotti et al., 1969). f: landslide; dt: eluvium, colluvium and debris; a3: holocenic alluvium; a2-1: post-glacial alluvium; fl3: upper pleistocene alluvium; m4-3: m. vallassa sandstones (tortonian-serravallian); m2-1: m. lumello marls (langhian – miocene pre-langhian); m1 c: castagnola formation (miocene pre-langhian); m1-o3: rigoroso marls (lower miocene – upper oligocene); m1-e3: antognola marls (miocene pre-langhian – upper eocene); o3-e3: ranzano sandstones (upper oligocene – upper eocene); e3-1: m. piano marls (upper eocene – lower eocene); pc-c7 cs: m. cassio limestones (paleocene – turonian); c: chaotic complex; i: undifferentiated complex; vvl: villalvernia-varzi line. 600 attiva). l’individuazione delle unità morfo-litotecniche è avvenuta tramite l’analisi dei dati geologici e geotecnici del sottosuolo del centro abitato di varzi. questi sono stati raccolti presso lo ster (regione lombardia servizio territoriale di pavia) e fanno parte degli studi geologici riguardanti gli interventi edilizi nei territori classificati sismici. la disponibilità di tali dati ha permesso di presentare un quadro sintetico di informazioni integrate sulle caratteristiche geologiche, sedimentologiche, idrogeologiche e geotecniche dei depositi alluvionali ed in particolare di quelli eluvio-colluviali. le indagini sono costituite da 132 trincee esplorative (profondità variabili da 1 a 5 m), 27 sondaggi (da 5 a 15 m) e 139 prove penetrometriche (da 4 a 12 m). le trincee esplorative hanno messo in evidenza le caratteristiche delle formazioni superficiali (coltri alluvionali ed eluvio-colluviali), i sondaggi e le prove penetrometriche hanno raggiunto il substrato e hanno permesso di ricostruire lo spessore dei terreni di copertura. le prove penetrometriche risultano l’elemento principale di caratterizzazione geotecnica dei terreni (n° di colpi correlato con la resistenza del terreno ed il suo potenziale di rigonfiamento). si tratta per lo più di prove dinamiche dcpt ed in minor quantità di cpt (n°19) e spt (n°2). il primo problema relativo alle prove dinamiche continue è stato quello di uniformare e validare i dati in possesso, infatti le prove sono state eseguite con tipi di penetrometri differenti (dphs meardi-agi e medio-leggero dl30) che si differenziano per spinta di infissione, maglio, altezza di caduta e penetrazione standard (uguale a 30 cm nella maggioranza dei casi, ma anche a 10 o 20 cm). la disponibilità di alcune misure spt effettuate in foro di sondaggio ha permesso indicativamente di trovare la seguente correlazione tra ndp e nspt: nspt ≈ 2ndp. il censimento degli edifici lesionati ha permesso di individuare le unità morfo-litotecniche che presentano particolari problematiche geologico-tecniche. il censimento é avvenuto mediante la consultazione presso lo ster delle richieste di finanziamento nel periodo 19801999 per interventi di ripristino di fabbricati privati e pubblici lesionati (contributi in conto capitale regolati dalle leggi statali/regionali:l.r. n°59/1978, m.per coord. prot. civile n°942 – 31.03.1987, dgr n°23463 23.12.1996, dgr n°43777 18.06.1999). i dati raccolti sono stati successivamente verificati sul terreno, questo ha permesso anche di identificare ulteriori edifici che non risultavano nelle pratiche consultate. per ogni fabbricato è stata compilata una scheda riportante le caratteristiche del terreno di fondazione, le caratteristiche costruttive dell’edificio stesso e il quadro fessurativo. le unità morfo-litotecniche argillose sono state caratterizzate anche mediante prove geotecniche di laboratorio. i campioni sono stati prelevati manualmente in corrispondenza di scarpate naturali o artificiali (scavi realizzati per fondazioni, tagli lungo la sede stradale). le profondità raggiunte, rispetto al piano campagna, sono comprese tra 1,5 e 3 m. nella descrizione c. meisina & l. rolandi fig. 2 flow-chart illustrante la metodologia di studio. flow-chart showing the methodology of study. 601 litostratigrafia è stata posta particolare attenzione alle caratteristiche diagnostiche del fenomeno di ritirorigonfiamento, quali la presenza di fessure di ritiro, superfici di pressione e di scivolamento (slickensides) (ahmad & mermut, 1996). in aggiunta alle tradizionali prove geotecniche di classificazione (limiti di atterberg, analisi granulometriche, ecc.), i campioni sono stati sottoposti ad analisi più specifiche, quali il test del blu di metilene (afnor, 1998), la misura della suzione matriciale con il metodo della carta da filtro (chandler & gutierrez, 1986) e la prova di rigonfiamento in parallelo (afnor, 1995). la prova del blu di metilene, consiste nel quantificare la capacità d’assorbimento ionico dei suoli, misurando la quantità di blu di metilene necessaria per ricoprire la superficie totale delle particelle costituenti il terreno. tale prova permette di avere indicazioni qualitative (tipi di minerali argillosi in funzione della misura della loro superficie attiva) e quantitative sulla frazione argillosa e quindi risulta di grande utilità nello studio delle problematiche connesse alle variazioni volumetriche dei terreni argillosi (magnan & youssefian, 1989; tourenq & tran ngoc lan, 1989; fytius et al, 2000). la prova di rigonfiamento in parallelo all’edometro consiste nell’applicare a provini di uno stesso campione carichi diversi per la misura della variazione percentuale di volume (deformazione dovuta al rigonfiamento) e della pressione di rigonfiamento (pressione necessaria per impedire la deformazione di volume) (fig. 3). tra le numerose prove di laboratorio esistenti per la misura della pressione di rigonfiamento essa viene considerata come la più attendibile (serratrice & soyez, 1996). il metodo della carta da filtro consiste nel misurare il contenuto in acqua di una carta da fi ltro standard (whatman n°42) a contatto con il terreno e si basa sull’ipotesi che all’equilibrio la suzione matriciale della carta da filtro e del campione siano gli stessi. la variazione della suzione con la profondità permette di determinare lo spessore della zona attiva. 4. unita’ morfologiche l’analisi degli aspetti geomorfologici (forme e processi) dell’area studiata, avvenuta tramite fotointerpretazione, ha permesso di identificare sei unità morfologiche preliminari, che sono il risultato di processi morfogenetici fluviali, di versante e antropici. le unità morfologiche di tipo fluviale sono rappresentate dall’alveo attivo del t. staffora, dai terrazzi dello stesso torrente visibili soprattutto in destra idrografica e dai conoidi degli affluenti. l’identificazione di tali unità ha comportato talora alcune difficoltà, connesse soprattutto all’intensa antropizzazione del nucleo urbano, che ha causato la parziale modificazione e/o scomparsa della loro forma. in questo contesto lo studio dell’evoluzione del reticolato idrografico ha fornito un valido strumento di identificazione delle unità morfologiche, permettendo, per esempio di tracciare il limite del conoide fossile del rio reponte superiore (fig. 4). accurate ricerche storiche dal xiv secolo ad oggi, hanno infatti messo in evidenza che tale rio ha subito nel tempo due spostamenti verso est. si suppone che nei secoli xiv-xv l’alveo del torrente, corrispondente all’attuale strada “vicolo del pozzo”, sia stato spostato ad est sul tracciato della via oggi conosciuta come “via reponte vecchio”. a riprova di ciò, durante i lavori di scavo eseguiti nelle cantine di un edificio del centro storico, è stato rinvenuto un muro di difesa spondale proprio lungo il tracciato presunto del rio. l’ultimo spostamento (da via reponte vecchio all’attuale sede) è avvenuto intorno al 1873. a quell’epoca il canale scorreva interamente a cielo aperto e solo durante la seconda metà del 1900 è stato progressivamente tombinato (debattisti, 1996). le unità legate a processi di versante sono derivate da fenomeni franosi e da fenomeni di erosione e di deposizione da parte delle acque non incanalate, che hanno portato alla formazioni di estese coltri eluvio-colluviali che coprono talora anche i terrazzi alluvionali più antichi. gli interventi antropici hanno prodotto notevoli modifiche dell’originaria morfologia dell’area, con prevalenza dei riporti a struttura lineare (rilevati stradali – ferroviari) e areale (fascia a ridosso delle difese di sponda destra). essi danno origine ad un’unità morfologica, definibile come made ground dalla classificazione dei terreni artificiali proposta dal british geological survey (ellison et al., 2002; rosenbaum et al., 2003). 5. unita’ morfo-litotecniche le unità morfologiche precedentemente descritte sono state successivamente analizzate in base alle caratteristiche litostratigrafiche, idrogeologiche e geotecniche, che predispongono i terreni al fenomeno di ritiro-rigonfiamento. a tal fine la fotointerpretazione è stata integrata con i dati di sottosuolo derivanti sia dai logs di sondaggi geognostici e di trincee esplorative che dall’analisi dei dati geofisici disponibili. l’insieme dei dati ha permesso di definire in dettaglio le litofacies, l’andamento e la distribuzione geometrica dei vari corpi litostratigrafici più superficiali, con particolare riguardo a quelli argillosi, sede delle variazioni di volume. successivamente sono state studiate le condizioni idrogeologiche (tipo di falda, soggiacenza della superficie piezometrica). i terreni sono stati, infine, caratterizzati sulla base delle proprietà geotecniche (potenziale di ritiro-rigonfiamento, spessore zona attiva). durante l’analisi dei dati sono emerse, anche in problematiche geologico-tecniche ... fig. 3 metodologia per la determinazione della pressione di rigonfiamento sp e della variazione percentuale di volume s. ∆h: variazione di altezza del campione dovuta al rigonfiamento, hi: altezza iniziale del campione. method used for the determination of sp and s. ∆h: height of swell due to saturation, hi: original height of the soil specimen. 602 questo caso, alcune difficoltà, connesse alla grande variabilità/eterogeneità dei depositi alluvionali ed eluviocolluviali, che ha talora reso difficile l’individuazione di zone omogenee, soprattutto nella zona urbana dove sono frequenti i materiali di riporto. sulla base dei criteri applicati (caratteristiche litostratigrafiche, idrogeologiche e geotecniche) le sei unità morfologiche sono state ulteriormente suddivise, ottenendo 13 unità, definite come morfo-litotecniche (fig. 5 e tab. 1), il cui scopo è quello di fornire informazioni riguardanti la suscettibilità al ritiro-rigonfiamento dell’area in esame. 5.1. caratteristiche litostratigrafiche le unità 1, 2, 4, 5 e 6 derivano dalle unità morfologiche di tipo fluviale. l’unità 1 è costituita dalle alluvioni attuali del t. staffora, che occupano la fascia di alveo attivo; esse risultano gradate e a composizione ghiaioso-ciottolosa con matrice fine (d = 10÷20 cm). nelle aree laterali, in destra ed in sinistra idrografica, si riconoscono situazioni differenti. stendimenti sismici a rifrazione eseguiti in sinistra idrografica nell’unità 2 hanno evidenziato uno spessore dei depositi alluvionali ghiaiosi fino a 8÷10 m, che porta ad ipotizzare l’esistenza in tale fascia di un paleoalveo sviluppato su una lunghezza di 400÷500 m e sede dell’acquifero che alimenta i pozzi dell’acquedotto. sulla sponda opposta tale unità ha una minore potenza ed inoltre é differenziata per composizione e grado di addensamento (livelli argillosi giallastri consolidati e ghiaiosi). la copertura limosa presenta uno spessore ridotto ed irregolare (<= 0,5÷1 m), e non è significativa ai fini geotecnici (fig. 6, profili n°1 e n°2): lo strato ghiaioso sottostante rappresenta infatti il principale riferimento per le fondazioni ricorrenti nell’area. in destra idrografica i ripiani alluvionali sono caratterizzati da terreni limoso-argillosi di spessore variabile da 0,5 a 5 m, che ricoprono in genere orizzonti c. meisina & l. rolandi fig. 4 evoluzione dell’alveo del rio reponte superiore. channel evolution of the upper reponte stream. 603problematiche geologico-tecniche ... fi g. 5 c ar ta d el le u ni tà m or fo -l ito te cn ic he . 19: u ni tà m or fo -l ito te cn ic he ( ta b el la 1 ); 10 : p ro fil i ge ot ec ni ci ; 11 : tr in ce e es p lo ra tiv e; 1 2: s on d ag gi m ec ca ni ci ; 13 : p ro ve p en et ro m et ric he ; 14 : p oz zi ; 1 5: e d ifi ci le si on at i; 16 : s tr ad e; 1 7: c an al e la go zz o. m or p ho -e ng in ee rin g ge ol og ic al t er ra in u ni t m ap . 1 -9 : m or p ho -e ng in ee rin g ge ol og ic al t er ra in u ni ts (t ab le 1 ); 10 : g eo te ch ni ca l p ro fil es ; 1 1: t re nc h p its ; 1 2: b or eh ol es ; 1 3: p en et ro m et er t es ts ; 1 4: w el ls ; 1 5: d am ag ed b ui ld in gs ; 1 6: r oa d s; 1 7: l ag oz zo c ha nn el . 604 c. meisina & l. rolandi tabella 1 descrizione e principali proprietà geotecniche delle unità morfo-litotecniche. s: spessore; p: acclività; k: permeabilità; d: condizioni di drenaggio; h: spessore della zona attiva. description and main geotechnical properties of the morpho-engineering terrain units. s: thickness; p: slope angle; k: permeability; d: drainage conditions; h: thickness of the active zone. unita' descrizione falda acquifera p k d h 1 ghiaia eterometrica con locali intercalazioni alveo attivo media sabbioso-limose. s: da 0 a 6-8 m del t. staffora subalvea <5° e alta buono 2 ghiaia e sabbia in matrice limosa con alluvioni recenti, falda superficiale copertura limoso-sabbiosa (s < 0,75 m), rilevate di circa a carattere stagionale da talora lenti limoso-sabbiose (s = 1-2 m). 2 m rispetto con soggiacenza < 2m; <5° media mediocre <0,5 spessori dell’unità variabili in destra all'alveo falda principale (> 3 m) a bassa e sinistra idrografica. sfruttata a scopo potabile 3 materiale risulta scavi e demolizioni (s = 1-2 m), talora con intercalazioni made ground variabile <5° molto variabile di argilla e limo. rilevati stradali e ferroviari variabile (ghiaie prevalenti). terrazzi alluvionali: alluvioni recenti falda acquifera alimentata limo argilloso con spessore da 1-2,6 m (superficie dal flusso subalveo del 4a fino a 5 m in prossimità dei versanti modificata da torrente staffora, <5° bassa mediocre 0,8 (apporti colluviali), talora misto a ghiaia. interventi soggiacenza < 4 m. antropici) ghiaie grosse frammiste ad argille (s <5 m) terrazzi alluvionali: falda alimentata soprastanti ghiaie medie in matrice alluvioni recenti, dal flusso subalveo 4b sabbioso-limoso. (s: 6-10 m). conoidi alluvionali dei torrenti <5° media buona presenza di strati di riporto (rio reponte sup.) staffora e reganzo, e alta con composizione eterogenea. soggiacenza < 3 m. limo argilloso con variazioni laterali a terrazzi alluvionali: 4c limo-sabbioso/sabbie fini soprastante alluvioni recenti soggiacenza < 4 m <5° bassa basso 1 ghiaia, presenza di strati di riporto. 5 limo argilloso con frazione detritica modeste percolazioni nei (apporti dai versanti) e/o ghiaiosa sparsa terrazzi alluvionali: livelli a componente <5° bassa mediocre 0,8 o concentratra ( s = 1 5 m) in lenti/livelletti alluvioni antiche ghiaiosa prevalente ed al appoggiante su ghiaia. (s= 10 m). contatto alluvione/substrato 6 clasti calcarei e limo argilloso giallastro conoidi circolazione idrica nei <5° media mediocre in alternanza o commisti. alluvionali livelli più permeabili limi argillosi e argille con detrito sparso di depositi colluviali possibile circolazione 7 spessore da 2 a 6 m, crescente da se a no. al piede idrica di modesta entità 5°-8° bassa basso 1,8 dei versanti nei livelli più permeabili argille e limi argillosi con detrito sparso accumuli possibile circolazione 8 e di spessore 2-4 m. di frana idrica di modesta entità 10°-15° bassa basso nei livelli più permeabili copertura localmente l'eterogeneità argilla con inclusi litoidi di varia eluvio-colluviale litologica e strutturale 9a-b dimensione e copertura di alterazione su bedrock può favorire la 10°-20° bassa mediocre 0,8 di spessore ridotto e irregolare (< 2 m). (complesso concentrazione di acqua caotico) (falde sospese) 9c alternanze di argille e calcari marnosi con copertura flussi idrici temporanei coltre di alterazione a componente eluvio-colluviale nella coltre argilloso-detritica (s = 3-4 m). la parte su bedrock argilloso-detritica 10°-20° media mediocre 0,8 superiore (1,2-1,5 m) è soggetta alle (calcari di fessurata per variazioni stagionali del contenuto in acqua m. cassio) essiccamento copertura eluvio-colluviale 9d marne e marne argillose su bedrock >15° bassa mediocre (marne di m. piano) alluvionali ghiaiosi (unità 4 con relative sottoclassi e 5 – fig. 6, profili n° 1 e 3). essi hanno distribuzione areale e spessore diversi, influenti sulle caratteristiche geotecniche. l’eterogeneità stratigrafica e geotecnica è complicata dalla presenza di conoidi fossili (unità 6) limitate al ripiano delle alluvioni antiche o estese anche alle alluvioni recenti (rii reponte superiore ed inferiore), nonché da depositi colluviali nella fascia di transizione al versante soprastante. negli strati argillosi consolidati sono spesso anche presenti superfici di scivolamento e di pressione (“slickensides”), caratteristiche di terreni che hanno subito variazioni di volume. il substrato impermeabile si trova ad una profondità media di circa 10 m. nell’unità 4b la coltre alluvionale raggiunge spessori di 10÷14 m. i sondaggi eseguiti hanno rilevato al di sotto della copertura vegetale (0,5 m) e fino a 4÷5 m di profondità un orizzonte eterogeneo, costituito da argilla limosa, con ghiaia talora dominante il cui spessore aumenta procedendo verso valle. seguono quindi ghiaie e sabbie ad elementi poligenici poco arrotondati con subordinata matrice limoso-argillosa diffusa o in lenti (fig. 6, profilo n° 3). nell’ambito dell’unità 4c si differenziano due strati (fig. 6, profilo n° 4): il superiore (la) essenzialmente limoso-argilloso di colore grigio-azzurro o grigio-bruno, saturo e di bassa consistenza, con variazioni laterali a limo sabbioso/sabbie fini (ls); l’inferiore (gh) costituito da ghiaia con ciottoli e limo addensati, di media permeabilità. l’unità 5, che interessa il terrazzo più elevato, comprende una copertura limosa argillosa con frazione detritica (apporti colluviali dalle incisioni del versante soprastante) (fig. 7) e uno strato ghiaioso-ciottoloso (gh1) di colore biancastro, interessato da una modesta circolazione idrica. sulle scarpate di raccordo dei ripiani alluvionali e al piede dei versanti è presente una copertura eluviocolluviale a matrice limoso-argillosa (unità 7) in parte derivata da frane antiche (unità 8) con spessore variabile da 2 a 4÷6 m (unità morfologiche di versante). l’unità 7 è costituita da terreni di medio-alta plasticità distinti in tre livelli: argilla con detrito di spessore 0,7÷1,8 m influenzata dalle variazioni stagionali di umidità (nspt<8) (c1 e c2), argilla con frammenti litoidi sparsi, struttura poliedrica e fessurata (9<nspt<16) (c3), substrato alterato (17<nspt<30) (fig.6, profilo n°3). la separazione tra i suddetti strati è segnata dalle variazioni di consistenza, di colore, di umidità e di struttura del terreno. il passaggio al substrato non è in genere netto per la presenza di una fascia di transizione con marne fessurate e parzialmente alterate. coltri eluvio-colluviali di minore spessore ricoprono la parte alta dei versanti (9a-b-c-d). l’unità 3 corrisponde all’unità morfologica di tipo antropico. la composizione dei materiali che la costituiscono (ghiaia, macerie di demolizioni, terriccio) è estremamente variabile sia verticalmente che in orizzontale. materiali antropici irregolarmente distribuiti sono ugualmente presenti nelle aree urbanizzate e ricoprono parzialmente le unità 4a, 4b e 4c. tali depositi sono costituiti da materiali eterogenei, provenienti in parte dall’esterno ed in parte dalla stessa area urbana. ad esempio nell’unità 4c gli strati di riporto (r1 e r2) accumulati in tempi diversi e con spessore complessivo di 3 m circa, hanno composizione eterogenea, più grossolana alla sommità, medio-fine inferiormente. la massa si presenta poco consolidata e con grado di permeabilità molto variabile (a contatto con i depositi limoso-argillosi alluvionali sono possibili filtrazioni di acqua) (fig. 6, profilo n° 4). 5.2. caratteristiche idrogeologiche i livelli ghiaiosi presenti alla base dei depositi alluvionali di fondovalle e nello stesso alveo attivo del t. staffora hanno una permeabilità medio-alta che favorisce l’infiltrazione e la circolazione dell’acqua negli stessi depositi, con l’instaurazione di una falda di subalveo, alimentata sia dai deflussi in alveo che da quelli laterali (apporti superficiali dai corsi d’acqua tributari e dai versanti; circolazione sotterranea da livelli permeabili del substrato). la potenzialità di questa falda è tuttavia variabile in funzione dello spessore e dell’estensione laterale della coltre alluvionale, delle condizioni del substrato e degli apporti superficiali. l’interpretazione dei dati disponibili di superficie (variazione di portata in alveo, condizioni geomorfologiche) e delle misure piezometriche (pozzi e sondaggi geognostici) e la loro correlazione con il profilo dell’alveo, portano ad ipotizzare una situazione di drenaggio o di quasi equilibrio tra alveo e falda subalvea. il regime della falda di subalveo è localmente influenzato anche dalla presenza delle opere trasversali (briglie) che in relazione alle condizioni di imposta, alle caratteristiche geometriche e costruttive esercitano una funzione di locale sbarramento, con innalzamento della piezometrica e contestuale sfioro in superficie della medesima (briglia in prossimità del ponte). l’esistenza nel fondovalle di 6 pozzi per acqua dell’acquedotto, con relative stratigrafie e misure dei livelli statici e dinamici, ha permesso più dettagliate valutazioni sulle falde presenti nelle unità litotecniche descritte. nell’unità 4b la falda acquifera, di modesta entità ed intercettata da due pozzi dell’acquedotto, è alimentata in parte dalla conoide del t. reganzo ed in parte dalle acque di subalveo del t. staffora (fig. 6, profilo n° 3). nell’unità 2, a valle della confluenza del t. lella, sono presenti più falde; la più profonda delle quali ha soggiacenza maggiore di 3 m ed é utilizzata dai pozzi dell’acquedotto (fig. 6, profilo n° 2). i depositi alluvionali più antichi (unità 5) sono sede di falde idriche laterali, sopraelevate rispetto a quella di subalveo. esse sono di entità modesta per il limitato spessore dello strato alluvionale permeabile ed in parte a carattere stagionale. sono inoltre parzialmente drenate dalle incisioni trasversali al t. staffora ed in parte versano direttamente le loro acque sulle scarpate frontali dei terrazzi che le ospitano. la falda acquifera superficiale è impostata nell’orizzonte ghiaioso e presenta un livello piezometrico generalmente inferiore ai 4 m. le misure piezometriche eseguite in vecchi pozzi in muratura indicano una maggiore soggiacenza (da 6 a 11 m) della falda acquifera in corrispondenza dei pozzi che raggiungono profondità da 10 m a 17 m e che quindi penetrano probabilmente nel substrato. l’idrogeologia dell’unità 7 è caratterizzata da una modesta ed irregolare falda acquifera per lo più a carattere stagionale con flusso sub-parallelo al pendio, alimentato principalmente dalle acque di precipitazione e 605problematiche geologico-tecniche ... 606 c. meisina & l. rolandi fig. 6 profili geotecnici relativi alle unità morfo-litotecniche 1, 2, 4a, 4b, 4c, 5 e 7. riporto r: materiale eterogeneo (detriti, macerie di demolizioni, terriccio) antico (1) e recente (2), poco consistente. depositi alluvionali: a: alluvioni attuali; ar: alluvioni recenti; f: alluvioni antiche; gh1: ghiaia e ciottoli prevalentemente calcarei con limo; gh: ghiaia e ciottoli con frazione limoso-sabbiosa in percentuale variabile; ls: limi sabbiosi e limi argillosi; a1: argilla soggetta a variazioni stagionali di umidità; a2: argilla leggermente sovraconsolidata per essiccamento; a+gh: argilla limosa con ghiaia. depositi alluvio-colluviali: la: limo argilloso grigio-bruno, consistente nella parte superiore (la1); prevalenza di limi sabbiosi (ls), sabbie medio-fini (sl) miste a ghiaia, mediamente addensate. depositi eluvio-colluviali c: c1: limo argilloso soggetto alle variazioni stagionali di umidità; c2: argilla limosa con frammenti marnoso-calcarei; c3: argilla limosa con frammenti marnoso-calcarei consolidata; cc: argilla di media consistenza. substrato s: substrato marnoso-argilloso di colore grigio-scuro, sovraconsolidato.; geotechnical profiles. artificial ground r: heterogeneous material (debris, building rubble, soil) old (1) and recent (soft) (2). alluvial deposits: a: riverbed; ar: recent alluvium; f: old alluvium; gh1: silty gravels and cobbles; gh: slightly to very silty/sandy gravels and cobbles; ls: sandy silt and clayey silt; a1: clay with volume change; a2: overconsolidated clay; a+gh: silty clay with gravel. alluvial-colluvial deposits: la: brown gray clayey silt, firm in the upper part (la1); sandy silt (ls), slightly gravelly medium to fine sand (sl) medium dense. colluvial deposits c: c1: clayey silt with swelling/shrinking phenomena; c2: silty clay with marly-calcareous boulders; c3: consolidated silty clay with marly-calcareous boulders; cc: firm clay. bedrock s: dark gray marly clay bedrock, overconsolidated. anche dalla circolazione idrica nelle intercalazioni calcareo-marnose del substrato (zona ad est rio reponte superiore), con soggiacenza variabile da 4,5 a 5,3 m. 5.3. caratteristiche geotecniche per ogni unità morfo-litotecnica il profilo stratigrafico é stato suddiviso in strati, in funzione della diversa resistenza alla penetrazione (intervalli di profondità all’interno dei quali i terreni presentano valori di n omogenei) (fig. 8). i profili evidenziano una grande eterogeneità geotecnica, particolarmente pronunciata per le unità 4b e 5. la presenza di strati ghiaiosi addensati o dello stesso substrato determina un incremento della resistenza alla penetrazione sulla verticale, dall’alto al basso (unità 4a, 5, 9a), in altri casi tale incremento è molto meno evidente per il minore addensamento degli strati ghiaiosi e la minore consistenza di quelli coesivi. il passaggio da orizzonti coesivi a strati ghiaiosi sotto falda acquifera è talora segnato da una diminuzione del numero di colpi (livelli limoso-sabbiosi meno addensati nelle unità 4b e 5). le unità morfo-litotecniche, con strato coesivo affiorante o subaffiorante di spessore maggiore o uguale a 3 m, sono caratterizzate da resistenze penetrometriche generalmente crescenti sulla verticale, da 2 a 26 nspt. in tale tendenza si evidenziano incrementi locali di resistenza riferibili a livelli decimetrici/metrici maggiormente consolidati per essiccamento (zona superiore), o per oscillazione della falda acquifera (zona intermedia) o alla presenza di frazione detritica nella matrice argillosa. la profondità della zona attiva nei depositi limoso-argillosi è stata stimata sulla base dei seguenti dati: valori di soggiacenza minimi e massimi della falda; prove penetrometriche dinamiche continue eseguite in terreni omogenei in periodi diversi (secchi e umidi) (un disseccamento del terreno comporta un aumento di resistenza del terreno e di conseguenza del numero di colpi); strutture pedologiche rilevate nel corso dell’esecuzione di trincee esplorative, quali la presenza e la profondità di fessure di ritiro e di slickensides; misura della suzione matriciale. la zona attiva, cosi verificata presenta uno spessore variabile da 0,8 a 1,8 m (tab. 1). i risultati sperimentali di laboratorio sono limitati ai terreni a prevalente composizione argillosa delle unità 4c, 5, 8 e 9 (tab. 2), per i quali il numero di colpi n30 risulta in genere inferiore a 10. si tratta di argille limose e limi argillosi di medio-alta plasticità, con un contenuto in acqua naturale appena superiore al limite plastico. l’unità 5 ha caratteristiche geotecniche molto variabili, che riflettono l’eterogeneità litologica già precedentemente descritta (tab. 2). nell’unità 7 la composizione 607problematiche geologico-tecniche ... fig. 7 distribuzione con la profondità delle caratteristiche fisico-meccaniche dell’unità morfo-litotecnica 5. wl: limite di liquidità; wp: limite di plasticità, ws: limite di ritiro; c: frazione argillosa; vb: valore al blu di metilene; rp: resistenza alla punta. physical-mechanical characteristics trend with depth of the 5 morpho-engineering geological unit. wl: liquid limit; wp: plastic limit; ws: shrinkage limit; vb: value of blue; rp: tip resistance. 608 fi g. 8 p ro fil i p en et ro m et ric i e c or ris p on d en ti st ra tig ra fie : ra ng e d i v ar ia zi on e d i n 30 p er u ni tà m or fo -l ito te cn ic a. 1 : ca ra tt er i d ia gn os tic i d el r iti ro -r ig on fia m en to , p re se nz a d i f ac ce d i p re ss io ne e d i s ci vo la m en to , s ov ra co ns ol id az io ne p er e ss ic ca m en to , f es su re d a rit iro ; 2 : l iv el lo f al d a ac q ui fe ra ; 3 : m at er ia le d i r ip or to ; 4 : l im o ar gi llo so , a rg ill a lim os a; 5 : g hi ai a co n in te rc al az io ni li m os oar gi llo se ; 6 : g hi ai a in m at ric e ar gi llo sa -l im os a; 7 : a rg ill a co n fr am m en ti lit oi d i; 8: s ub st ra to a lte ra to ; 9 : s ub st ra to m ar no so ; 1 0: n ° d i c ol p i m as si m o; 1 1: n ° d i c ol p i m in im o. p en et ro m et ric p ro fil es a nd s tr at ig ra p hi es : ra ng e of n 30 fo r ea ch m or p ho -e ng in ee rin g te rr ai n un it. 1 : d ia gn os tic c ha ra ct er is tic s of s w el lin gsh rin ka ge , cr ac ki ng , sl ic ke ns id es ; ov er co ns ol id at io n d ue t o d es ic ca tio n; 2 : g ro un d w at er le ve l; 3: a rt ifi ci al g ro un d ;4 : c la ye y si lt, s lit y cl ay ; 5 : g ra ve l w ith c la y an d s ilt in te rb ed d ed ; 6 : g ra ve l w ith in a s ilt y cl ay m at rix ; 7 : c la y w ith b ou ld er s; 8 : w ea th ere d b ed ro ck ; 9 : m ar ly b ed ro ck ; 1 0: m ax n um b er o f p en et ro m et er b lo w s; 1 1: m in n um b er o f p en et ro m et er b lo w s. c. meisina & l. rolandi granulometrica dei terreni esaminati (presenza in molti casi di blocchi eterometrici) ha reso difficile il campionamento e comunque poco significative le misure sperimentali di laboratorio. secondo il metodo proposto da williams & donaldson (1980) le unità 5, 8 e 9a-b presentano un potenziale di rigonfiamento da alto a molto alto (fig. 9), evidenziato anche dagli elevati valori al blu di metilene. le prove di rigonfiamento all’edometro eseguite su campioni naturali delle unità 5 e 9a-b, in condizioni di saturazione e con densità secca variabile da 13,0 a 16,6 kn/m3, hanno misurato delle variazioni di volume comprese tra 0,7 e 1,6 % e una pressione di rigonfiamento da 97 a 273 kpa. al fine di determinare la massima variazione di volume che i terreni possono sviluppare, le medesime prove sono state eseguite su campioni ricostituiti con un’umidità pari al limite di ritiro; i valori misurati (>=25%) riflettono l’elevata predisposizione al rigonfiamento (fig. 10). la variazione delle proprietà fisiche e meccaniche nello strato argilloso superiore, campionato ed esaminato in laboratorio, presenta una buona correlazione con il diagramma di resistenza alla penetrazione misurato 609 tabella 2 principali parametri fisico-meccanici delle unità morfo-litotecniche argillose unità 4c, 5, 7, 8, 9. wl: limite di liquidità; ip: indice plastico; c: frazione argillosa; vb: valore al blu; w: contenuto in acqua naturale; γd: densità secca; sr: grado di saturazione. main physical-mechanical parameters of the morpho-engineering geological units. wl: liquid limit; ip: plasticità index; c: clay content; vb: value of blue; w: natural water content; γd: dry density; sr: saturation degree. unita' wl ip c (%) vb (g/100g) w (%) γd (kn/m3) sr (%) 4c 69 48 25,9 1,58 98,8 5 33-84 18-61 34-58 2,58-8,98 21,9-35,7 1,32-1,66 88-100 8 59-64 34-43 29-63 1,19-1,67 65-98 9a-9b 57-69 37-49 32-56 5,6-6,08 1,5-1,68 80-100 fig. 9 carta di attività modificata (williams & doldson, 1980). activity modified chart. fig. 10 variazione percentuale di volume. swelling strain. problematiche geologico-tecniche ... per lo stesso deposito con prove penetrometriche dinamiche e statiche. in particolare queste ultime mostrano un maggiore grado di definizione e di dettaglio nel rilevare orizzonti differenziati, alla pari dei risultati sperimentali puntuali distribuiti sulla verticale (fig. 7). 6. valutazione della suscettibilita’ al ritiro-rigonfiamento ogni unità morfo-litotecnica, precedentemente descritta, è individuata da specifiche caratteristiche litostratigrafiche, idrogeologiche e geotecniche, che rappresentano i fattori predisponenti il fenomeno di ritirorigonfiamento nell’area di studio (tab. 3). al fine della valutazione della suscettibilità alle variazioni di volume, ad ogni fattore è stato assegnato un peso in funzione della sua importanza nel determinare il ritiro e/o il rigonfiamento del terreno. la suscettibilità è stata calcolata come sommatoria dei pesi dei vari fattori. i valori ottenuti sono stati successivamente riclassificati in quattro classi qualitative (suscettibilità bassa, media, alta, molto alta) (tab. 3). presentano una suscettibilità alta e molto alta al ritiro-rigonfiamento le unità caratterizzate da una copertura alluvionale o eluvio-colluviale prevalentemente argillosa sovrastante strati ghiaiosi (unità 4a, 5) o direttamente a contatto con il substrato marnoso-argilloso (unità 7, 8 e 9a-b). in questa associazione di unità morfo-litotecniche, che interessa il 52% dell’area studiata, può rientrare anche l’unità 4c, nelle situazioni in cui lo spessore del riporto é inferiore allo spessore della zona attiva. la suscettibilità di tali depositi al ritiro-rigonfiamento è confermata, oltre che dai risultati sperimentali di laboratorio, dalle strutture presenti nel terreno (fessure subverticali da ritiro, superfici di pressione e di scivolamento), che testimoniano lo sviluppo del fenomeno anche in tempi geologici, e dalla distribuzione degli edifici lesionati. i fabbricati dissestati sono ubicati su pendio con quote diverse di fondazione, in relazione alla forma in pianta, alla presenza di cantinati e di riporti sul lato valle. le strutture portanti sono prevalentemente in muratura. gli edifici hanno due o più piani fuori terra, con presenza di cantina o di seminterrati. le fondazioni sono di tipo diretto continuo, generalmente in muratura (meno frequentemente in calcestruzzo), con profondità di posa variabile da 0,5 a 3 m in funzione della morfologia del pendio e della presenza o meno di piani interrati totali o parziali. la maggior parte degli edifici ricadono nelle unità 7 e 8 (17 e 24 edifici/km2 rispettivamente). nel primo caso le lesioni, registrate in evoluzione nel 1989-1991, appaiono connesse prevalentemente a fenomeni di ritiro del terreno argilloso. nel secondo caso il dissesto sembrerebbe connesso per lo più a frane. tuttavia il fenomeno di ritiro-rigonfiamento interessa anche le coperture argillose coinvolte da movimenti di versante. in questi terreni, normalmente poco permeabili o impermeabili, la fessurazione indotta dal610 tabella 3 fattori e pesi scelti per la valutazione della suscettibilità sc al ritiro-rigonfiamento dei terreni argillosi. classi di suscettibilità: b: bassa; m: media; a: alta; ma: molto alta. factors and weights used for the swelling-shrinking soil susceptibility (sc) assessment. susceptibility classes: b: low; m: medium; a: high; ma: very high. 1 1 1,5 1 2 1 2 1 1,5 1,7 1,6 1,5 1 3 4a 2 2 2 1,6 2 4b 1,3 1 1 1,6 1 4c 2 2 2 1,6 2 5 1,5 2 2 1,6 2 6 1,3 1 1,3 1,5 7 1,5 2 2 2 1,5 8 1,5 2 2 2 9a 1,5 2 1,7 1,5 9b 1,5 2 1,7 1,5 9c 1,5 2 2 1,5 9d 2 1 1,3 1,5 b m 1,3 ma b 1,6 ma 1,3 a b 1,6 ma ma 1,3 a 1,3 a 1,3 ma m u n it à ar gi lla e li m o < = 5 0 50 -1 00 10 020 0 > 20 0 > 10 4 < d < = 1 0 2 < d < = 4 d < 2 b as so m ed io cr e b uo no < 0 ,5 0, 5 1 1 2. > 2 m s c gh ia ia e s ab b ia ar gi lla e li m o co n in cl us i l ap id ei gh ia ia in m at ric e ar gi llo so -l im os a ar gi lla e li m o co nt in ui ar gi lla e li m o in in te rc al az io ni (n on p re d om in an ti) ar gi lla e li m o in in te rc al az io ni (p re d om in an ti) criteri utilizzati per la valutazione della suscettibilità al ritiro-rigonfiamento condizioni spessore soggiacenza zona attivalitologia geometriche argilla della falda drenaggio (m)limo (cm) (m) c. meisina & l. rolandi l’essiccamento (ritiro) favorisce all’arrivo delle piogge, dopo un periodo siccitoso prolungato, un elevato assorbimento di acqua nello strato superficiale. tale fenomeno, ripetuto nel tempo con cicli stagionali, determina la deformazione e l’instabilità per scivolamento della massa argillosa (rigonfiamento per saturazione, formazione di superfici di taglio e instaurazione di pressioni neutre elevate nelle fessure e nei pori). ai fini delle problematiche di fondazione si individua anche un secondo gruppo di unità morfo-litotecniche costituito dalle unità 2 e 4b, con un’estensione pari al 8 % della superficie di indagine, non soggetto al fenomeno di ritiro-rigonfiamento. esso è caratterizzato da un orizzonte superiore ghiaioso piuttosto eterogeneo e di spessore 2 – 2,5 m, giacente su strati limoso-argillosi compatti, sotto una debole copertura limoso-argillosa o di riporto. 7. conclusioni la disponibilità di una cospicua mole di dati, ha permesso in un’area urbana a geologia complessa con prevalenza di coperture quaternarie (“formazioni superficiali”), la definizione di un quadro conoscitivo di dettaglio dei depositi alluvionali, eluvio-colluviali ed antropici, generalmente descritti in maniera indifferenziata. l’indagine geologico-tecnica, rappresentata nelle diverse fasi operative, ha consentito di individuare più unità morfo-litotecniche, ciascuna delle quali definite da caratteristiche geomorfologiche, litostratigrafiche, idrogeologiche e geotecniche relativamente omogenee. un ulteriore sintesi ha permesso di raggruppare le suddette unità in associazioni caratterizzate da specifiche problematiche geologico-tecniche riconducibili ai seguenti schemi: 1. strato argilloso di spessore 3-5 m con elevata suscettibilità al ritiro-rigonfiamento su orizzonte ghiaioso addensato o sullo stesso substrato marnoso (unità 4a, 5, 7, 8, 9a e 4c). le proprietà geotecniche sono generalmente crescenti con la profondità, pur presentando locali riduzioni riferibili a livelletti meno consolidati o a composizione limoso sabbiosa ed incrementi in livelli induriti da essiccamento o da oscillazione della falda acquifera o contenenti una frazione detritica nella matrice argillosa; 2. strato ghiaioso eterogeneo di spessore 2-2,5 m, su orizzonte limoso-argilloso, talora con ghiaia, compatto e di spessore da 2 a 6 m (unità 2 e 4b). la carta delle unità morfo-litotecniche costituisce il supporto preliminare per affrontare problematiche applicative, tra le quali anche lo studio della suscettibilità al ritiro-rigonfiamento dei terreni argillosi, causa di numerose lesioni agli edifici dell’area. essa è utile anche per identificare le aree problematiche che richiedono studi di dettaglio (es. unità 4a, 4c, 5 e 7). lo studio, condotto nell’abitato di varzi, ha evidenziato le seguenti problematiche: • assenza di carte delle “formazioni superficiali” (generalmente non rilevate nelle carte geologiche di “vecchia generazione”), con terminologie (nomenclature stratigrafiche standard) e classificazioni facilmente comprensibili anche per i non addetti ai lavori; • nelle aree urbane le “formazioni superficiali” sono soggette alle trasformazioni antropiche e di conseguenza sarebbe auspicabile poter disporre anche di una classificazione dei depositi di natura antropica; • i processi genetici (geologici e geomorfologici), che sono causa della formazione di terreni problematici, quali quelli soggetti a variazione di volume, possono modificare ed influenzare le caratteristiche geologicotecniche degli stessi; il loro studio appare di conseguenza di primaria importanza per le applicazioni geologico-tecniche. ringraziamenti gli autori ringraziano la regione lombardia – sede territoriale di pavia (ster), in particolar modo l’ing. malaspina e il geom. bartilucci, per i dati messi a disposizione relativi alle indagini geognostiche effettuate (studi geologici riguardanti gli interventi edilizi in territorio classificato sismico) e agli edifici lesionati nel comune di varzi. bibliografia afnor (1995) essai de gonflement a l’oedometre norme française homologuée, xp p94-060-1. afnor (1998) mesure de la quantité et de l’activité de la fraction argileuse) determination de la valeur de bleu de méthylène d’un sol par l’essai a la tache norme française homologuée, nf p94-068. ahmad n. & mermut a. (eds.) (1996) – vertisols and technologies for their management developments in soil science, 24, 566, elsevier science ltd. beatrizzotti g., bellinzona g., beltrami g., boni a., braga g., marchetti g., mosna, s. (1969) geological map of italy fg. 71 – voghera (2nd ed) servizio geologico d’italia, roma. bell f.g. & bruyn i.a. (1997) sensitive, expansive, dispersive and collapsive soils. bulletin of the international association of engineering geology, 56, pp. 19-38. braga g., braschi g., calculli s., caucia f., cerro a., colleselli f., grisolia m., piccio a., rossetti r., setti m., spalato a., soggetti f., veniale f. (1985) i fenomeni franosi nell’oltrepo pavese: tipologia e cause geologia applicata e idrogeologia, 20, pp.621-666. bre (1996) desiccation in clay soils digest, 412. cerrina feroni a., otaria g., martinelli p., martelli l. 2002 structural geological map of the emilia romagna apennines. firenze. selca. chandler r.j. & gutierrez c.i. (1986) the filter paper of suction measurement géotechnique, 36 (2), pp.265-268. chen f.h. (1988) foundations on expansive soils developements in geotechnical engineering vol.18, elsevier scientific publishing company, amsterdam, 464 pp. debattisti f. (1996) storia di varzi – guardamagna editors ellison r.a., mcmillan a.a., lott g.k. (2002) – ground characterisation of the urban environment: a guide to practice – british geological survey research report, rr 02-05. ©nerc copyright 2002 british 611problematiche geologico-tecniche ... geological survey, nottingham, contributors: kessler h., lawley r.s.. fityus s.g., smith d.w., jennar a.m. (2000) surface area using methylene blue adsorption as a measure of soil expansivity. proc.int.conf. on geotechnical & geological engineering geoeng2000, melbourne, 19-24 november 2000 (on cd). magnan j.p. & youssefian g. (1989) essai au bleu de méthylène et classification géotechnique des sols bull.liaison labo p. et ch., 159, pp. 93-104. mcmillan a.a. & powell j.h (1999) – bgs rock classification scheme, volume 4: classification of artificial (man-made) ground and natural superficial deposits – applications to geological map and datasets in the uk british geological survey research report, rr 94-04. ©nerc copyright 1999 british geological survey, nottingham, contributors: evans c.d.r., irving a.a.m., merritt j.w., morigi a.n., northmore k.j. meisina c. (1998) analisi dei processi evolutivi del t. staffora proc. int. conf. "la prevenzione delle catastrofi idrogeologiche: il contributo della ricerca scientifica", alba 5-7 novembre 1996, 2, pp. 157-167. mouroux p., margom p. & pinte j.c. (1988)la construction économique sur sols gonflant bureau de recherches géologiques et minières manuels et méthodes n.14, orleans. page c.(2003) shrinkable soils in the united kingdom an ongoing national disaster int. conf. on problematic soils:29-30 july, 2003, nottingham, 1, pp. 73-82. rosenbaum m.s., mcmillan a.a., powell j.h., cooper a.h., cushaw m.g. & northmore k.j. (2003) classification of artificial (man-made) ground engineering geology, 69, pp. 399-409. serratrice j.f. & soyez b. (1996) les essais de gonflement bulletin des laboratoires des ponts et chaussees, 204, pp. 65-85. tourenq c., & tran ngoc lan (1989). mise en evidence des argiles par l’essai au bleu de methylene. application aux sols, roches et granulats bull. liaison labo p. et ch., 159, pp. 79-92. williams a.b., & donaldson g.w. (1980) developments relating to building on expansive soils in south africa: 1973-1980 proc. 4th int. conf. on exp. soils, denver, 2, pp. 834-844. 612 c. meisina & l. rolandi ms. ricevuto l’11 maggio 2004 testo definitivo ricevuto il 30 novembre 2004 ms. received: may 11, 2004 final text received: november 30, 2004 sess 0_retro e indice edi.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 integrating archeological and geomorphological data to evaluate the late holocene evolution of the kartalini basin (georgia) stefano furlani1, alberto stinghen2, luca bertoldi2, elisabetta boaretto3, aldino bondesan1, david kuparadze4, matteo massironi2, giovanni monegato2 & elena rova5 1dipartimento di geografia “g. morandini”, università degli studi di padova, italy 2dipartimento di geoscienze, università degli studi di padova, italy 3helen kimmel center for archaeological science, israel 4caucasian institute of mineral resources, tbilisi, georgia 5dipartimento di scienze dell’antichità e del vicino oriente, università ca’ foscari, venezia, italy corresponding author: s. furlani <sfurlani73@gmail.com> abstract: furlani s. et al., integrating archaeological and geomorphological data to evaluate the late-holocene behaviour of the kartalini basin (georgia). (it issn 0349-3356, 2011) a multidisciplinary approach has been used to evaluate the late-holocene modifications of the kartalini basin (georgia). data from satellite images (corona, landsat, russian aerial images, etc) and field surveying allowed to reconstruct the neotectonics in the area of aradetis orgora archaeological site. riassunto: furlani s. et al., comparazione di dati archeologici e geomorfologici per la valutazione del comportamento del bacino di kartalini (georgia) dal tardo-olocene. (it issn 0349-3356, 2011) per studiare le modificazioni tardo oloceniche del bacino di kartalini (georgia) è stato utilizzato un approccio multidisciplinare. i dati provenienti dale immagini satellitari (corona, landsat, foto aeree russe, ecc) e i rilievi di campagna hanno permesso di ricostruire l’evoluzione neotettonica nell’area del sito archeologico di aradetis orgora. key words: geoarchaeology, active tectonics, late holocene, kura river, georgia parole chiave: geoarcheologia, tettonica attiva, tardo olocene, fiume kura, georgia archaeological and geomorphological data are very useful to study holocene river meandering because of the close relations between the presence of water and human settlement. .in the meantime, both the geomorphological evolution and the development of human settlements could be heavily conditioned by active tectonics effects (differential uplift, seismicity) in this study we aim to outline the late holocene evolution of the aradetis orgora site, through the analysis of archaeological and morphological data,. the site is located in the transcaucasian basin, historically characterized by active tectonics (adamia et al. (1977), gamkrelidze et al. (1986) e philip et al. (1989), gudjabidze, 2003) and it is poorly studied from a geomorphological point of view. 1. the study area the study area is located in the shida kartli region, a hundred kilometres west from tbilisi. the kura river crossed the area following a nnw-sse direction, while the liakhvi river represents an important tributary, which flows into the kura near the modern city of gori. the site of aradetis orgora-dedopolis gora is located at the junction of a system of rivers (kura, western prone, eastern prone). in particular, aradetis orgora lies on an isolated portion of the fluvial terrace (660 m a.s.l.), about 20 meters above the recent kura floodplain (640 m a.s.l.). the site hosted an important settlement roman/ medieval in age, which wasexcavated by georgian archaeologists under the direction of prof. julon gagoshidze (fürtwängler et al., 2008). the classical antiquity occupational levels are underlain by a long sequence of earlier levels, which date back at least to the late 4th millennium bc, and are still virtually unexplored. 2. the archaeological site of aradetis orgora the stratigraphic analysis was carried out on an exposed section on the southern sector of the terrace slope, where the archaeological levels are superimposed to an alluvial stratigraphy related to the kura river and its tributaries. starting from the base, three main archaeological levels have been identified (fig. 2): 1) an early bronze age level characterized by a sequence of layers with abundant pottery and ceramics fragments of the kura-araxes and bedeni periods (late 4th-mid 3rd millennium bc) in a muddy matrix. radiocarbon dating of a wood 186 188 187 fragment from the base of the sequence yielded the age of the layer (±1σ 3025-2920 bc,). the level had been buried by a coarse alluvial event characterized by 1,5 m thick gravel body; 2) a late bronze age layer characterized by muddy matrix with abundant pottery fragments; 3) a roman age and later layer at the topmost part of the site, characterized by abundant pottery and brick fragments. the presence of alluvial deposits between the two bronze age levels indicates a channel fluvial activity on the terrace after 4300 bp. we suggest two possible hypothesis about the drainage evolution: a) the gravel layer covering the early bronze age could represent the last phase of aggradation of fig. 1 the study area / l’area di studio fig. 1 the aradetis orgora archaeological site / il sito archeologico di aradetis orgora integrating archaeological and geomorphological data ... 188 ms. received: testo ricevuto il the liakhvi alluvial fan and its progradation toward south. subsequently the deepening of the kura riverbed and its northward migration triggered the small incisions of the trenches surrounding the site. the roman age site was probably chosen for the isolated position derived from the geomorphological evolution of the terrace. according to the present difference in elevation between the liakhvi alluvial surface and the present kura riverbed, the estimated total erosion is about 5 mm/ year, that is the result of a joined effect between river incision and active uplift of the area. b) the gravel layer may be ascribed to a palaeokura (present western prone river) running waters. after about 4000 bp, the kura was forced to migrate toward south because of an active uplift of the transcaucasian region. in this case, most of the 20 metres in the elevation difference between palaeo and present kura should be related to tectonic activity. the importance of tectonic activity in the area is furthermore supported by the high seismicity of the transcaucasian basin (philip et al., 1989; triep et al., 1995) and the low fluvial erosion expected in a time span in which no great climatic changes occurred. local uplift within the basin possibly related to a contractional step-over along the borjomikazbegi fault zone or the southern propagation of the greater caucasus belt. acknowledgements we are kindly grateful to mindia jalabadze (georgian national museum), who accompanied us on the site during the 2009 season. the field survey in the aradetis orgora area took place in the framework of the “georgian-italian shida kartli archaeological project” (rova, 2008) of ca’ foscari university of venice. this was funded by ca’ foscari university, ministero degli affari esteri, and the shelby white-leon levy program for archaeological publications. references adamia sh.a., lordkipanidze m.b. & zakariadze g.s. (1977) evolution of an active continental margin as exemplified by the alpine history of the caucasus. tectonophysics, 40, 183-199. furtwangler a., gagoshidze i., lohr, h. & ludwig n. (2008) iberia and rome. the excavations of the palace at dedoplis gora and the roman influence in the caucasian kingdom of iberia, langenweissbach 2008. gamkrelidze i.p. (1986) geodynamic evolution of the caucasus and adjacent areas in alpine time. tectonophysics, 127, 261-277. gudjabidze g.e. (2003) geological map of georgia, 1:500.000. georgian state department of geology and national oil company “saqnavtobi”. philip h., cisternas a., gvishiani a. & gorshkov a. (1989) the caucasus: an actual example of the initial stages of continental collision. tectonophysics, 161, 121. rova e., puturidze m. & makharadze z. (2010) the georgian-italian shida kartli archaeological project: a report on the first two field seasons 2009 and 2010, rivista di archeologia. triep e.g., abers g.a., lerner-lam a.l., mishatkini v., zakharchenko n. & starovit o. (1995) active thrust front of the greater caucasus: the april 29, 1991, racha earthquake sequence and its tectonic implications. journal of geophysical research, 100, b3, 4011-4033. january 15, 2011 15 gennaio 2011 s. furlani et al. imp.soligo nneeww uu--sseerriieess ddaattiinngg ooff aa ccaarrbboonnaattee lleevveell uunnddeerrllyyiinngg tthhee ppeeppeerriinnoo aallbbaannoo pphhrreeaattoommaaggmmaattiicc iiggnniimmbbrriittee ((ccoollllii aallbbaannii,, iittaallyy)) mmiicchheellee ssoolliiggoo,, ppaaoollaa ttuucccciimmeeii,, gguuiiddoo ggiioorrddaannoo,, rreennaattoo ffuunniicciieelllloo && ddoonnaatteellllaa ddee rriittaa dipartimento scienze geologiche, università "roma tre", largo s.l. murialdo 1, 00146 roma , italy. correspondence should be addresses to paola tuccimei: tuccimei@uniroma3.it abstract increasing attention has been recently devoted to the last phases of the colli albani activity (rome, italy), in consideration of new stratigraphic data suggesting a possible holocene activity of the volcanic complex located few kilometres to the south of the city of rome. in particular the focus has been directed to the activity of the albano maar and related pyroclastic deposits, the youngest eruptive centre of the colli albani volcano. the most recent dated product from the albano maar is known as peperino albano (pa) ignimbrite, which has been dated with several different techniques. the age of the pa spans between 51 and 19 ka. a recent study has shown that pa is overlain by at least other two pyroclastic deposits and several lahar deposits, all separated by paleosoils, making the recent eruptive history of the albano maar rather younger than previously thought. the exact age determination of the recent succession is therefore a key issue to be tackled in order to evaluate the volcanic hazard in the roman region. the aim of this paper is to improve the chronology of the last eruptive episodes of the albano maar, by dating a carbonate layer interbedded within the recent deposits using u-series disequilibria. the idea came out from the discordant results obtained by applying different dating methods to pa ignimbrite as a consequence of the difficulties connected with the application of classical isotope chronological methods to young volcanic products. in order to date the carbonate layer, the total sample dissolution technique (tsd) has been preferred to using leachates alone because the leaching method gives reliable results only in the case of simple dissolution of the carbonate fraction, without any removal of u and th isotopes from the detritic component. three coeval sub-samples from the carbonate level underlying pa have been analysed, giving an age of 22.9 ± 6.7 ka, younger than other previous chronological data. the age limit of about 23 ka found for pa supports the hypothesis of a possible very recent activity of the albano maar, justifing the increasing efforts devoted to improving the chronology of the last phreatomagmatic phases of colli albani volcano. riassunto una crescente attenzione è stata recentemente dedicata alle ultime fasi dell'attività dei colli albani (roma, italia), in considerazione di nuovi dati stratigrafici che suggerirebbero una possibile attività olocenica del complesso vulcanico situato pochi chilometri a sud della città di roma. in particolare, l'attenzione è stata focalizzata sul più recente centro eruttivo dei colli albani (maar di albano) e sui depositi piroclastici ad esso associati. il più recente tra i prodotti datati del maar di albano è un'ignimbrite conosciuta come peperino di albano (pa). tale unità è stata datata con differenti tecniche e le età ottenute sono comprese tra 51000 e 19000 anni. un recente studio mostra come pa sia ricoperto da almeno altri due depositi piroclastici e ulteriori due lahar, tutti separati da paleosuoli, dimostrando che la recente storia eruttiva del maar di albano sia più giovane di quanto sinora ritenuto. l'esatta determinazione dell'età di questa successione risulta pertanto un obbiettivochiave nella valutazione del rischio vulcanico nell'area romana. lo scopo di questo lavoro è fornire un approccio alternativo per migliorare la cronologia degli ultimi episodi eruttivi del maar di albano, attraverso la datazione col metodo dei disequilibri nella serie dell'uranio di un livello carbonatico intercalato ai prodotti del maar sopramenzionato. l'idea è scaturita dai risultati discordanti ottenuti applicando differenti metodi di datazione al peperino di albano, riconducibili alle difficoltà spesso connesse alla datazione diretta di prodotti vulcanici recenti. al fine di datare il livello carbonatico, la tecnica della dissoluzione totale del campione (tsd) è stata preferita all'uso dei soli lisciviati poiché l'analisi di questi ultimi fornisce risultati attendibili solo in caso di una semplice dissoluzione della frazione carbonatica, senza la rimozione preferenziale di u e th dalla componente detritica. sono stati analizzati tre subcampioni coevi appartenenti al livello carbonatico sottostante il peperino di albano e l'età risultante è pari a 22900 ± 6700 anni. questo dato è il più recente tra quelli sinora ottenuti e corrobora l'ipotesi di una possibile recentissima attività del maar di albano, giustificando il crescente impegno speso nel migliorare la cronologia delle ultime fasi freatomagmatiche del vulcano dei colli albani. keywords: u-series dating, peperino, ignimbrite, colli albani, italy parole chiave: datazioni, serie dell'uranio, peperino, ignimbrite, colli albani, italia il quaternario italian journal of quaternary sciences 1166(1bis), 2003, 115-120 11.. iinnttrroodduuccttiioonn the first attempt to date colli albani volcanic complex date back to about 35 years ago when evernden and curtis (1965) dated leucite crystals by k/ar obtaining ages ranging from 706 to 268 ka. during the 1960's and 1970's the k/ar method was further developed (gasparini & adams, 1969; masi et al., 1976; biddittu et al., 1979 bernardi et al., 1982) giving results comparable with the previous data. in the same years other radiometric methods based on u-series disequilibria (th/u isochrons and fission tracks) were used (cerrai et al., 1965; taddeucci, 1969; bigazzi & ferrara, 1971) supporting the occurrence of recent volcanic activity in the interval 67-43 ka. in the 1980's and 1990's, 39ar/40ar method was associated to k/ar and th/u systematics (e.g. karner and renne, 1998). the application of the three methods to the main volcanic units permitted the 116 m. soligo et al. improvement of the chronological knowledge of the complex (radicati di brozolo et al., 1981; andretta & voltaggio, 1988). notwithstanding the numerous papers dedicated to define the chronology of colli albani activity, various problems related to the different methods arose. the first, connected with the application of k/ar method, was suggested by villa (1988) who envisaged the presence of excess argon in the analysed materials. further difficulties arose from the direct comparison of 39ar/40ar and th/u methods applied to the same products. villa (1992) and voltaggio et al. (1994) found in three samples out of four systematically 39ar/40ar ages older than those obtained by th/u, presumably due to excess argon in microscopic inclusions in leucite crystals. according to villa (1988) the presence of excess 40ar can be identified from an accurate examination of the spectra, but if the excess 40ar is uniformly distributed (voltaggio et al., 1994) there is no way of distinguishing between radiogenic and inherited argon. also the th/u isochron method can be affected by problems, the main of which being related to the initial isotopic heterogeneity of the thorium activity ratio. this paper focuses on the age determination using the u-series disequilibria of a carbonate level found at the base of the peperino albano (pa) ignimbrite, one of the most recent products from the colli albani volcano, erupted from the albano maar. the age determination should be independent from the above mentioned uncertainty factors, and its importance is therefore twofold: 1) it helps at determining the controversial age of the peperino albano ignimbrite, which has been dated using 14c, u/th disequilibrium and thermoluminescence techniques (fornaseri and cortesi, 1989 and references therein; mercier, 1993), with reliable ages spanning between 51,000 years ago and 19,000 years ago and clustering around 29-30 ka (fornaseri and cortesi, 1989). 2) it constrains the recent activity of the colli albani volcano which is much more complex and recent than usually believed, as the carbonate layer has been found at the base of a newly exposed stratigraphic section, where the peperino albano is overlain by several other phreatomagmatic and lahar units (funiciello et al., 2002) 22.. ggeeoollooggiiccaall sseettttiinngg the colli albani volcano is a large composite caldera complex located about 20 km south-east of the city of rome (fig.1). it is one of the several volcanoes belonging to the nw-trending volcanic belt parallel to the tyrrhenian coast of central italy active during the last 600 ka, belonging to the roman magmatic province (e.g. serri, 1990; ferrara and manetti, 1993). the colli albani volcano is at present considered a quiescent volcano (de rita et al., 1995a) characterised by seismic and hydrothermal activity (amato and chiarabba, 1995; calcara et al., 1995). the style of activity of the colli albani volcano has been characterised mainly by explosive activity throughout its volcanic history. the stratigraphy has been subdivided in three main successions corresponding to three epochs of activity. the lowest, named the tuscolano-artemisio succession, was emplaced between less than 600 ka and 350 ka and comprises seven main large-volume, caldera-forming, low aspect ratio ignimbrite units. the tuscolano-artemisio succession comprises the most voluminous and widespread deposits of the colli albani volcano (fig. 1) (de rita et al. 1995b). the last large-volume ignimbrite-forming eruption caused the final collapse of the central 10 km x 10 km wide caldera at 350 ka (de rita et al. 1988; de rita et al., 1995b). after the collapse, the volcanic activity changed drastically into strombolian and effusive accompanied by a significant reduction of the average mass eruption rate. during this epoch of activity, named le faete epoch which lasted approximately from 350 ka and 270 ka, a small stratovolcano named le faete edifice was formed within the collapsed area (de rita et al., 1995b). the most recent volcanic activity of the colli albani volcano, the final epoch of activity, has been characterised by several, small volume, monogenetic phreatomagmatic eruptions from eccentric maars, whose products form the final hydromagmatic succession (de rita et al., 1995b). phreatomagmatic eruptions occurred from single and coalescent craters. the albano maar is the most recent of these craters, wherefrom the peperino albano ignimbrite erupted (de rita et al., 1986; giordano et al., 2002). different attempts have been carried out to date the peperino albano. a first was conducted on unburned ulmus and quercus ilex wood samples giving a 14c roma maar albano 0 5 10km 41°55° 41°50° 41°45° 41°40° 41°35°n 12°27°e litosoma albano 260 ka recente; ca. 1km3 di prodotti) formazione del tavolato (<23.000-<5000 anni) formazione del tavolato (<23.000-<5000 anni) alluvioni e depositi costieri recenti orlo di caldera cono di scorie orlo di maar samling site unità sedimentarie pre-vulcaniche litosoma tuscolano-artemisio (600 350 ka; ca. 280 km3 di prodotti) piroclastiti lave prodotti freatomagmatici litosoma delle faete (350 270 ka; ca. 6 km3 di prodotti) 12°50° 12°57° fig. 1 geological map of alban hills area (rome, italy). upper age of 29.7 ± 0.4 ka (de vries, in fornaseri et al., 1963). further radiocarbon determinations were performed on similar samples and the obtained ages were higher than 37 ka (alessio et al., 1966; fornaseri, 1985). more recently fornaseri and cortesi (1989) reported a radiocarbon age of 29.9 ± 0.3 ka. this range is in agreement with ar/ar age determination from sediment-cores ascribed to pa eruption and drilled at the centre of the lake (chondrogianni et al., 1996). also villa et al. (1999) dated unalterated leucite crystals from other sedimentcores by ar/ar. they found that the evolution of the crater was a multistage process that took place in the last 45 ka. two stages out of five (the first and the third), were dated at of 45 ± 3 and 26 ± 1 ka, respectively. in addition, a th/u isochron was realized using different mineral phases from the peperino albano (andretta, 1988) with the resulting age of 51 ± 14 ka. mercier (1993) used the thermoluminescence technique to date calcareous inclusions within pa obtaining an age of about 20 ka. finally the recovering of uran-pyrochlore in sanidine ejecta of the iv hydromagmatic units from the albano maar has allowed to date the age of crystallization of these mineral phases by the u/th method at 45 ± 1.3 ka (voltaggio and barbieri, 1995). 33.. ssttrraattiiggrraapphhyy figure 2 shows the stratigraphic section investigated in this study. this section was recently exposed thanks to roadworks related to the enlargement of the gra freeway, in the ciampino area, located along the nw slope of the colli albani volcano. the detailed stratigraphy of this section is reported in funiciello et alii, in press, to which the reader is referred to. the succession has been interpreted by the authors as the post-wurmian, possibly up to the holocene filling of a paleovalley cut in the underlying tuscolano-artemisio epoch’s deposits. the succession from base to top is composed by: a) fluvial lacustrine silt and sand b) phreatomagmatic surge deposit related to the iv eruption from the albano maar c) fluvial sand and conglomerate d) peperino albano ignimbrite e) syn-eruptive reworked deposits from the peperino albano ignimbrite f) phreatomagmatic surge deposit g) debris flow lahar deposit f) hyperconcentrated flow lahar deposit the carbonate level (fig. 3) was deposited at the top of unit a, which is composed of diffusely stratified silt and clay, likely from a caco3-rich swamp, similar to the 117new u-series dating of a carbonate ... many swamps that occur in several places around the colli albani area, where co2 rich fluids upwell to the surface. it must be underlined that the ciampino area is still the site of intense co2 release (e.g. giordano et al., 2000; carapezza et al., 2002) 44.. ssaammpplliinngg aanndd mmeetthhoodd 44..11 tthheeoorreettiiccaall ccoonnssiiddeerraattiioonnss three coeval sub-samples from the carbonate level underlying the last erupted products from albano maar were collected and analysed by u-series method, according to the total-sample dissolution (tsd) technique developed by bischoff and fitzpatrick (1991) for dating impure carbonates. the choice of such a method has been preferred to using leachates alone (schwarcz and latham, 1989) because the leaching method gives reliable results only in the case of selective dissolution of the carbonate fraction, without any removal of u and th isotopes from the detritic component, or when u and th are leached without any fractionation. generally this condition is not verified because u and th are often fractionated and th can be readsorbed onto the residual component. when analysing samples consisting of simple mixtures of carbonate and a detritic component, the phreatomagmatic surge fig. 2 stratigraphic section of grande raccordo anulare (gra) succession: a) fluvial lacustrine silt and sand, b) phreatomagmatic surge, c) fluvial sand and conglomerate, d) peperino albano, e) lahars, f) phreatomagmatic surge, g) debris flow, h) hyperconcentrated flow. 118 use of tsd method is to be preferred to determine the age because the sample is totally dissolved and consequently no preferential leaching or readsorption occur. in order to successfully apply this method it is required that the various coeval subsamples have different u/th ratios, but the same (230th/232th) activity ratio when deposited. tsd method assumes that: 1) the detritic component is homogenous and characterised by a constant u/th ratio or 2) it is a heterogeneous mixture of two or more minerals with different u/th ratio, but similar (230th/232th). in both cases the resulting age is that of formation of the carbonate. the age of the carbonate level was calculated measuring the (230th/232th), (234u/232th) and (238u/232th) activity ratios of several coeval subsamples in order to obtain the value of (230th/234u) and (234u/238u) activity ratios in the pure carbonate fraction. such values are respectively calculated from the slopes of the regression lines in the (230th/232th) vs (234u/232th) and (234u/232th) vs (238u/232th) isochron plots reported in figure 4a and 4b. calculations have been carried out using isoplot, a plotting and regression program for radiogenic-isotope data (ludwig, 1994). 44..22 aannaallyyttiiccaall tteecchhnniiqquuee samples were crushed and ultrasonically washed in deionised water. fragments were also checked with a stereoscopic microscope to discard any recrystallised portions. about 10 g of sample were dissolved with 7 n hno3. the insoluble residue was removed by centrifugation and successively digested in concentrated hf + hclo4 + hno3, taken to dryness and redissolved in 7 n hno3. the resulting solution was mixed with the carbonate solution and spiked with a tracer containing 228th in secular equilibrium with 232u. u and th were coprecipitated with fe(oh)3 using nh4oh and successively redissolved in 10 n hcl and loaded onto anionic dowex ag1-x8 resin to separate th from u. thorium fraction was furthermore purified onto a second anionic dowex ag1x8 resin conditioned with 7 n hno3 and eluted with 10 n hcl. u and th isotopic complexes were extracted from nitric solutions respectively at ph 3.5 and 1.5 using thenoyltrifluoroacetone (tta) in toluene and loaded onto a glass planchet and flamed. u and th were finally alpha-counted using high resolution ion implanted ortec silicon surface barrier detectors. 55.. rreessuullttss uranium and thorium concentration, activity ratios and ages are summarised in table i. quoted uncertainties are 1 standard deviation (± 1 sigma). resulting isochrons are shown in fig. 4a and 4b. data points are finely distributed on the (230th/232th) vs (234u/232th) and (234u/232th) vs (238u/232th) isochron plots and arranged in two straight lines whose correlation coefficients r are higher than 0.96. the obtained age is equal to 22.9 ± 6.7 ka. m. soligo et al. fig.3 view of the dated carbonatic level in layer a (fluvial lacustrine sand and silt), close to the limit with the overlying level b (phreatomagmatic surge), as in figure 2. fig 4b (234u/232th) versus (238u/232th) isochron plot of the three carbonate sub-samples from gra section. fig. 4a (230th/232th) versus (234u/232th) isochron plot of the three carbonate sub-samples from gra section. uranium abundances of different subsamples range from 4 to 4.6 ppm, thorium contents vary from 4.7 to 9.6 ppm and (234u/238u) activity ratio in the pure carbonate fraction is around 1. such data demonstrate that 119 carbonate depositing fluids have circulated within a volcanic bedrock usually characterised by high uranium content and (234u/238u) activity ratios close to equilibrium. in addition, the high obtained thorium concentrations are consistent with a volcanic nature of the insoluble residue. 66.. ddiissccuussssiioonn aanndd ccoonncclluussiioonn the peperino albano ignimbrite erupted from the albano maar has been dated several times by the application of different methods. resulting ages differ significantly from each other and range between 51 and 19 ka. as mentioned before, data from the direct analyses of crystals of pa are affected by various problems of isotope disequilibria, but also 14c determinations on carbon-rich samples in volcanic areas (leaves, branches etc.), where intense co2 emissions occur, can be unreliable (calderoni and turi, 1998). actually, the carbon isotopic composition of organism living close to sites of intense co2 release in air can be presumably depleted in radiogenic carbon and consequently the obtained ages are not correct and result too old. in light of this, it is necessary to produce an independent dating of pa in order to better constrain the chronology of last products from albano maar. this aim has been reached with the determination of the age of the carbonate level outcropping in the gra stratigraphic section and underlying pa. the u-series method using tsd (total sample dissolution) technique is to be preferred when analysing an impure carbonate with a relevant detritic component because it allows the overcoming of problems connected with the differential leaching and adsorption of u and th isotopes from the insoluble residue. in view of this, the obtained results can be considered reliable. the age of 22.9 ± 6.7 ka determined for the carbonate level indicate a very recent eruptive history of the albano maar, rather younger than previously thought. this finding assumes a significant value especially in consideration of the recently described pyroclastic and lahar deposits overlying pa ignimbrite (see fig. 2). it is worth noting that such products are also separated by paleosoils indicating that a considerable span of time has to have been elapsed since the emplacement of the pa. this points to a possible holocene age of the products filling the paleovalley cut into the tuscolanoartemisio volcanic succession to the nw of the albano maar. such considerations also allow the re-evaluation of datings from andretta & voltaggio (1988) who proposed a very recent activity of the colli albani complex, although that work did not clarified which stratigraphic layers were dated. in conclusion, the recent activity of the albano maar, needs more study in order to better define the volcanic hazard in the colli albani region because of the proximity of this area to a large city like rome. rreeffeerreenncceess alessio a., bella f., calderoni g., bachechi f., cortesi c., l., 1966 university of rome carbon 14 dates iv. radiocarbon, 88, 401-412. amato a., chiarabba c., 1995. seismicity. in: trigila, r. (ed.), the volcano of the alban hills, tipografia sgs, roma, pp. 213-223. andretta d., 1988 cronologia 230th e modellistica evolutiva delle vulcaniti recenti del complesso vulcanico dei colli albani (roma). tesi di dottorato di ricerca in scienze della terra, università "la sapienza", roma. biblioteca nazionale di roma e fierenze, 138 pp. andretta d., voltaggio m., 1988 la cronologia recente del vulcanismo dei colli albani. le scienze, 4411, 243, 26-36 bernardi a., de rita d., funiciello r., innocenti f., villa i.m., 1982 chronology and structural evolution of alban hills volcanic complex, latium, italy. short papers of 5th international conferene on geochronology and isotope geochemistry, nikko (japan), 23-24. biddittu i., cassoli p.f., radicati di brozolo f., segre a.g., segre naldini e., villa i., 1979 anagni, a k/ar dated lower and middle pleistocene site, central italy: preliminary report. quaternaria, 2211, 53-71. bigazzi g., ferrara g., 1971 determinazione dell'età di zirconi con il metodo delle tracce di fissione. rendiconti della società italiana di mineralogia e petrologia, 2277, 295-304. bischoff j.l., fitzpatrick j.a., 1991 u-series dating of impure carbonates: an isochron technique using total-sample dissolution. geochimica et cosmochimica acta, 5555, 543-554. calcara, m., lombardi, s., quattrocchi, f., 1995. geochemical monitoring for seismic surveillance. in: trigila, r. (ed.), the volcano of the alban hills, tipografia sgs, roma, pp. 221-243. calderoni g., turi b,., 1998 major constraints on the use of radiocarbon dating for tephrochronology. quaternary international, 4477--4488, 153-159. carapezza m.l., badalamenti b., cavarra l., scalzo a., 2002. gas hazard assessment in a densely inhabited area of colli albani volcano (cava dei selci, roma). j. volcanol. geotherm. res., submitted. cerrai f. dugnani lonati r., gazzarzini f., tongiorgi e., new u-series dating of a carbonate ... table i u-series isotope data and resulting age of the carbonate level from gra section. subsample (230th/232th) (238u/232th) (234u/232th) u ppm th ppm (234u/238u)carb. (230th/234u)carb. age (ka) gra a 0.87 ± 0.01 2.25 ± 0.09 2.34 ± 0.09 4.02 ± 0.01 5.37 ± 0.10 gra b 0.99 ± 0.02 2.64 ± 0.08 2.64 ± 0.08 4.21 ± 0.09 4.73 ± 0.12 1.05 ± 0,07 0,19 v 0.05 22.9 ± 6.7 gra c 0.74 ± 0.02 1.43 ± 0.06 1.40 v 0.06 4.64 ± 0.10 9.61 ± 0.30 120 1965 il metodo ionio-uranio per la determinazione dell'età di minerali vulcanici recenti. rendiconti della società mineralogica italiana, 2211, 47-62 chondrogianni c., aritzegui d., niessen f., ohlendorf c,, lister g.s., 1996 late plesitocene and holocene sedimentation in lake albano and lake nemi (central italy). in guilizzoni p. &. oldfield f. eds "palaeoenvironmental analyses of italian crater lake and adriatic sediments (paliclas) " special volume nem. ist. ital. idrobiol., 5555, 23-38. de rita d., funiciello r., pantosti d., 1986 dynamics and evolution of the albano crater, south of roma. proc. iavcei int. conf., kagoshima: 502-505. de rita d., funiciello r., parotto m., 1988 carta geologica del complesso vulcanico dei colli albani. cons. naz. ric., prog. finalizzato geodin., roma. de rita d., giordano g., rosa c., sheridan m.f., 1995a volcanic hazard at the alban hills and computer simulations. in trigila r. ed. "the volcano of the alban hills tip. sgs. roma, 267-283 de rita d., faccenna c., funiciello r., rosa c.,1995b stratigraphy and volcano-tectonics. in trigila r. ed. "the volcano of the alban hills. tip. sgs. roma, 33-71. evernden j.f., curtis g.h., 1965 the potassiumargon dating of lare cenozoic in east africa and italy. current antropology, 66, 363-364. ferrara, l., manetti, p., 1993. geodynamic framework of the tyrrhenian volcanism: a review. acta volcanol. 33, 1-9. fornaseri m., 1985 geochronology of volcanic rocks from latium (italy). rendiconti della società italiana di mineralogia e petrologia, 4400, 73-106 fornaseri m., cortesi c., 1989 recenti acquisizioni sull'età del "peperino" di albano. documenta albana, ii serie, 1111, 7-10. funiciello r., giordano g., de rita d., 2002 the albano maar lake (colli albani volcano, italy): recent volcanic activity and evidences of preroman age catastrophic lahar events. j. volcanol. geotherm. res., in press. gasparini p., adams a.s., 1969 k-ar dating of italian plio-pleistocene volcanic rocks. earth and planetary science letters, 66, 225-230. giordano, g., mazza, r., cecili, a., capelli, g., de rita, d., bigi, g., rodani, s. (2000) cit ies on volcanoes: groundwater resources and managment in a highly populated volcanic region. a gis in the colli albani region, rome, italy. j. nepal geol. soc. 2222,, 315-326. giordano, g., de rita, d., cas, r.a.f., rodani, s., 2002 valley pond and ignimbrite veneer deposits in small volume phreatomagmatic basic ignimbrite, lago albano maar, colli albani volcano, italy: influence of topography. j. volcanol. geotherm. res., spec. vol., in press. karner, d., renne, p.r., 1998. 39ar/40ar geochronology of roman volcanic province tephra in the tiber river valley: age calibration of middle pleistocene sea-level changes. geol. soc. am. bull. 111100, 740747. ludwig k.r., 1994 isoplot. a plotting and regression program for radiogenic-isotope data. us geological survey. open file report, 91-445. masi u., nicoletti m., petrucciani c., 1976 ulteriori datazioni di prodotti del vulcano laziale. rendiconti della società italiana di mineralogia e petrologia, 3322, 113-118. mercier n., 1993 the thermoluminescence dating technique: application and possibilities. in follieri m., girotti o., kotsakis t., taddeucci a. & turner c. ed "symposium on quaternary stratigraphy in volcanic areas inqua seqs-c abstracts" roma, p 49 radicati di brozolo f., huneke j.c., papanastassiou d.a., wasserburg g.t., 1981 40ar/39ar and rb-sr age determinations on quaternary volcanic rocks. earth and planetary science letters, 5511, 445-456. schwarcz h.p., latham a.g., 1989 dirty calcites 1. uranium-series dating of contaminated calcites using leachates alone. chemical geology, 8800, 3543. serri, g., 1990. neogene-quaternary magmatism of the tyrrhenian region: characterization of magma sources and geodynamic implications. mem. soc. geol. it. 4411, 219-242. taddeucci a., 1969 uranio e torio nei minerali di alcune piroclastiti dei colli albani. disequilibri isotopici e possibilità di datazione. periodico di mineralogia, 3388, 463-476. villa i.m., 1988 excess ar in k-rich volcanites: the role of fluids. rendiconti della società italiana di mineralogia e petrologia, 4433, 1, 95-104 villa i.m., 1992 datability of quaternary volcanic rocks: an ar-40/ar-39 perspective on age conflicts in lavas from the colli albani, italy. european journal of mineralogy, 44, 369-383. villa i.m., calanchi m., dielli e., lucchini f., 1999. age and evolution of the albano crater lake (roman volcanic province). acta vulcanol., 1111(2): 305-310 voltaggio m., andretta d., taddeucci a., 1994 230th238u data in conflict with 40ar/39ar leucite ages for quaternary volcanuc rocks of the colli albani, italy. european journal of mineralogy, 66, 209-216. voltaggio m., barbieri m., 1995 "geochronology". in trigila r. ed. "the vulcano of the alban hills. tip. sgs roma, 167-192. m. soligo et al. ojs377 racano et al.pdf available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 35 (1), 2022, 31-45 1. introduction the integration of history and earth sciences can lead to the production of datasets useful for understanding the impacts of past geological processes on human communities. the collection of historical information has always been of great importance for reconstructing climatic, environmental and landscape changes, and particularly to determine the evolution of flood and landslide risks (guzzetti et al., 2005; 2012). four basic pieces of information were identified by van westen et al. (2006) to support landslide risk assessment and management: (1) landslide inventories, (2) information on the environment surrounding the landslides, (3) information on the landslide triggers and (4) information on the elements at risk (in the past or in the present). the integration of several methods is necessary to produce reliable information that can be combined with geotechnical quantitative data in view of modelling (e.g. remote sensing and photogrammetry, soeters & van westen, 1996; geomorphological field investigations, brunsden, 1985) and public reporting/interviews and archival research for historical contribution (tropeano & turconi, 2004; salvati et al., 2009). in general, landslide occurrence is controlled by several predisposing factors (e.g. topography, geology and human activities, arca et al., 2018) and trigger processes (e.g. rainfall, glacial melting, stream and coastal erosion, earthquakes and volcanic eruptions, lichkov, 1938; crandell et al., 1984; keefer, 1984; mathewson et al., 1990; mcinnes, 1996; suarez, 1996). moreover, several researchers have argued that urbanization impacts landslide risk by influencing the severity and frequency of landslides, as well as the extent and value of building exposure and the degree of vulnerability to damage (smyth & royle, 2000; douglass et al., 2005; fedeski & gwilliam, 2007; mandasari et al., 2016; zope et al., 2016). if the fragility of a territory depends on the https://doi.org/10.26382/amq.2022.02 a peculiar history of destruction in the old village of castel frentano, central italy, from reconstruction of landslide effects followed by earthquake damage in 1881. simone racano1, sara amoroso2-3, matteo del nobile4, fabrizio galadini3 1 universität potsdam, institute für geowissenschaften, potsdam, germany. 2 department of engineering and geology, university of chieti-pescara, pescara, italy. 3 istituto nazionale di geofisica e vulcanologia, rome, italy. 4 writer and journalist, castel frentano, italy. corresponding author: simone racano < racano@uni-potsdam.de > abstract: anthropogenic modifications of the landscape (e.g. urbanization, deforestation and agricultural activities) act as geomorphic processes, producing fast changes and instabilities, which often lead to landslides along hillslopes and floodings in lowlands. anthropogenic modifications have increased with the progress of civilization; therefore, coupling historical information and geomorphological data can provide key information to determine the anthropogenic impacts on landscape evolution. the case of castel frentano, a village in the abruzzo region (central italy), has been analysed to shed light on the causes of its destruction in 1881: during the summer of that year, the village was heavily damaged by a peculiar succession of paroxysmal events, i.e. a massive landslide followed by a strong earthquake. this earthquake induced additional damages to the buildings, due to seismic shaking and slide reactivation. this study involved geomorphological and geological surveys, which were aimed at mapping and defining the main presently active geomorphic processes in the area of interest; moreover, we researched 19th-century historical documents to reconstruct the genesis and evolution of the events that led to landsliding in 1881. although the study area has always been prone to instability phenomena (due to its local geological and geomorphological characteristics), our results revealed that sliding was most likely triggered by human activities that had strongly modified the hillslope. historical sources revealed a general hillslope instability that progressively evolved in the 1881 landslide because of deforestation. that deforestation had been carried out for agricultural exploitation on a previously stable territory. in this view, the case of castel frentano exemplifies the relationship between human activities, landscape modifications and their consequences in italy in terms of risks to both natural and anthropogenic environments. this is particularly important to assess at present: in a historical period characterized by economic growth, strong demographic expansion and the consequent fast colonization of natural spaces. keywords: historical geology, human impact, natural hazards, urban changes, landscape response. 32 racano s. et al. interrelation of natural and anthropogenic factors, then historical knowledge about landscape changes caused by human action and land use is necessary to completely understand the predisposing factors (dapples et al., 2002; glade, 2003; alcántara-ayala et al., 2006; beguería, 2006; gariano et al., 2018). the castel frentano landslide (cfl) represents a case study in central italy (fig. 1). in this study, it was investigated through a combination of geological and historical approaches to clarify the evolution of natural processes and their impacts on surrounding buildings. during the summer of 1881, castel frentano, a typical italian hillside village of medieval origin, suffered the effects of a massive landslide that occurred on its eastern hillslope. this event was followed a few weeks later by a 5.4-magnitude earthquake that struck the central periadriatic sector, as reported in nature notes (1881): “on thursday (september 10th) last, at noon, further shocks of earthquake alarmed the inhabitants of orsogna, lanciano, and castel frentano, where a landslip did serious damage” (nature notes, 1881). differently from many other landslide cases in italy, which were triggered by earthquakes (e.g. agnesi et al., 1983; chiodo et al., 1999), the cfl occurred before a seismic event and was sufficient to cause significant building collapses and damages. the successive earthquake induced further significant damages and the reactivation of the slide about 40 days after its first trigger. this peculiar combination of slope sliding and seismic shaking determined a “continuous” building damage through a period of several months. although the cfl has been already studied from a geotechnical point of view (mancini et al., 2001), the genesis and evolution of the event, as well as the predisposing factors and triggers, are still not clear. through this study, we investigated the factors that conditioned the cfl in 1881: we combined geological, geomorphological and topographic information about the eastern hillslope of castel frentano with historical information (not limited to the events of that year, but extending to preceding times). after defining the geological framework and describing the 1881 earthquake event, fig. 1 location of castel frentano (yellow) and extent of the geological map of the area shown in fig. 2 (red). 33 damages caused in castel frentano in 1881 by a landslide and an earthquake. fig. 2 (a) synthetic geological map of the central abruzzo periadriatic area; (b) sketch of castel frentano’s geology (modified from racano et al., 2020). we discuss the available geomorphological and historical data to provide a realistic interpretation of the landslide origin. 2. geological, geomorphological and seismological framework of the castel frentano area the hill of castel frentano is located on pliopleistocene marine to coastal units characteristic of the entire periadriatic sector (fig. 2a,b). the relief, whose altitude gradually decreases from the maiella piedmont to the adriatic coast, was produced by a regional uplift during the quaternary (centamore & nisio, 2003; centamore & rossi, 2009; racano et al., 2020). the main lithology outcropping in the area consists of bluish clays, sometimes interbedded with silty-sandy layers, that gradually upward to yellow silty-sandy levels and finally to sands interbedded with conglomerates, which mark the end of marine sedimentation (bigi et al., 1997; centamore & nisio, 2003; racano et al., 2020). the hill is bounded by steep slopes, which have been formed by the linear incisions of creeks draining the area. the main stream channel is the feltrino creek (fig. 2b), which drains the eastern slope of the hill. one of the main geomorphological consequences of the recent geological evolution of the area is its predisposition to large landslides. due to the recent uplift and the weakness of superficial lithologies, the drainage system has produced narrow and steep valleys carved into a highly erodible substratum. these are evident landslide predisposing conditions that can explain the recent/present landscape evolution (centamore et al., 1996). the avi (italian vulnerable areas for landslides and floods, developed by the national research council of italy) and pai (hydrogeological plan, provided by the abruzzo region) catalogues list rotational landslides, earth flows and “rill erosion” phenomena on clays (which produce badlands just below the urban centre). in terms of hazard, the castel frentano area is classified as a p3 zone (i.e. a high hazard zone: affected by active or seasonally reactivated instability phenomena). the most important gravitational movement (i.e. a rotational landslide) has been detected along the eastern slope of castel frentano’s hill (mancini et al., 2001). the main activation of this landslide occurred on the 31st of july, 1881, generating the collapse of the village’s eastern sector. on the 10th of september, 1881, the landslide was reactivated by an earthquake (savarese et al., 2011) (fig. 3a,b). foreshocks of this seismic event, which preceded the main landslide motion, are not reported in seismic catalogues (e.g. rovida et al., 2022) and historical sources (savarese et al., 2011), nor mentioned in the literature published after the occur 34 racano s. et al. fig. 3 (a) structural map of buried structures (from racano et al., 2020) and historic seismicity between 1800-2000 (from rovida et al., 2022): mt (maiella thrust); cbt (casoli-bomba thrust); act (abruzzo citeriore thrust); cst1-2 (coastal thrusts 1-2); pel (pescara line); anl (alento line); frl (foro line); mrl (moro line); fel (feltrino line); avl (aventino line); sgl (sangro line); (b) damage distribution of the 1881 orsogna earthquake (from locati et al., 2022). impact on the landscape (i.e. portion of involved hillslope, temporal evolution of the phenomenon), the extent of damage caused to the village (i.e. involved buildings) and any indication related to the possible triggers of the cfl (i.e. geological active processes, climate, seismicity and anthropogenic changes of the landscape). most of the data were derived from the historical archive of the castel frentano municipality. many documents produced by the city council in the 19th century were found to contain suitable information; in particular, the documents archived in folder b9, file f168 (18611881) and folder b10, file f169 (1881-1926) focus on land use activities on the eastern slope of castel frentano’s hill and on the evolution of the landslide. these bibliographic data were integrated with documents from the italian state archives (state archive of chieti, chietisection lanciano, pescara, l’aquila-section sulmona and the diocesan archive of lanciano), which consisted mostly of telegrams, newspaper reports and climatic reports. the information gathered from the archive research was combined with that from published studies on climate and meteorological trends (giraudi, 1990; maugeri et al., 2004) and from the local literature (mainly books on castel frentano’s history; del nobile, 2011; scioli, 1981, 1998). 4. results 4.1. geomorphological features of castel frentano’s hill the plio-pleistocene deposits representing the substratum of castel frentano’s hill are sub-horizontal or gently dip eastwards from the ridge towards the valley bottom. the village is located at the top of the hill: it seats on a narrow plateau composed of consolidated sands and conglomerates, which represent the stiffer lithology of the study area and have a maximum thickness of about 20 m (fig. 4a). an 8-10-m-thick layer of fine sands and silts marks the downward transition to the blue clays of the mutignano formation, which pervasively outcrop in the study area. the hillslopes were and are still exploited by pervasive agricultural activities, which have led to the development of soil from the thick silty colluvium covering the bedrock. these colluvial deposits have derived from extensive weathering processes and gravitational deformations that have affected all the slopes. evidence of slow earthflow movements in the absence of large paroxysmal events was detected along the sw flank of the hill; however, landslides are widespread on the eastern flank. similarly to the earthflows of the western flank, the landslides on the eastern flank mainly involve the colluvium cover. this has led to the generation of terraces and sub-circular scarps typically associated with rotational landslides. moreover, the presence of water springs characterized by ephemeral flows, mostly located in correspondence of the landslide terraces (where the slide planes intersect the surface), indicates a shallow water circulation influenced by seasonal rainfall variations. the erosional processes are highlighted by linear and v-shaped incisions triggered by run-off and mainly related to the feltrino creek catchment, which deeply rence of the paroxysmal events (niccoli, 1882). although the occurrence of foreshocks cannot be completely excluded, it is at least highly improbable, since potential precursors are typically reported in the literature and reports coeval to strong historical earthquakes. the seismic event that occurred in 1881 was reported to have a 5.4-magnitude (fig. 3a,b) (cpti15 catalogue; rovida et al., 2022) and was attributed to the activation of a blind reverse fault related to the abruzzo citeriore thrust system (de nardis et al., 2011), which represents the external and younger expression of the central apennines. the epicentre of that seismic event was located at about 5 km nnw from the study area (fig. 3a). the mainshock was responsible for moderate damages to castel frentano (mercalli-cancani-sieberg intensity, mcs = 7-8) and nearby villages (poggiofiorito, mcs = 8; guardiagrele and orsogna, mcs = 7-8; lanciano, mcs = 7) according to the dbmi15 macroseismic database (locati et al., 2022) (fig. 3b). the earthquakeinduced damages added to those caused by the july and september landslide movements. therefore, the estimation of the effects strictly induced by seismic shaking is very difficult and affected by uncertainties: the present topography and urban setting of the eastern hillslope of castel frentano are the overall product of an earthquake and of one main landslide event that occurred in 1881. traces of slope instability related to continuous superficial slow movements (creep) and earth flows have been detected along the western flank of the hill. these events have also affected the urban centre (buccolini et al., 2000), although they have not evolved in paroxysmal events comparable to the 1881 landslide. 3. materials and methods this study integrates pieces of information collected through field geological and geomorphological surveys with the results of bibliographic and archive research on historical sources. the aim was to reconstruct the genesis and sequence of events related to the 1881 cfl. the collected field investigations allowed the production of a map depicting the landslide area (on the eastern slope of the castel frentano hill), in order to highlight the main geomorphic processes acting on it and the lithologies involved. this map was used as a base to define the geometries of the landslide scarp and body, as well as the lithologies involved in the movement and the main geomorphic processes that might have triggered it. the field data were digitised in a gis environment using the open-source software qgis (https://www.qgis.org). the base map was developed from the regional cartography of the abruzzo region at scale 1:5000 (in esri shapefile format) and the digital elevation model (in tiff format) of the region with a resolution of 10 m/px. the gis data are freely available on http://geoportale.regione.abruzzo.it/cartanet. several archives were consulted to determine the sequence of events related to the landslide that occurred in 1881. in particular, we searched for descriptions of the landslide (i.e. geometry and extension, magnitude of the phenomenon and involved lithologies), its 35 damages caused in castel frentano in 1881 by a landslide and an earthquake. 36 racano s. et al. fig. 4 (a) geological and geomorphological map of castel frentano; (b) slope map of castel frentano’s hill; (c) topographic and slope profiles. and linearly cuts the eastern hillslope. despite the differences in slope-movement between the western and eastern flanks of castel frentano’s hill, the slope values of the two flanks are not significantly different (fig. 4b,c). the most significant feature in this regard is a prominent scarp located at the southeastern edge of the village (fig. 4b), which corresponds to the area with the highest slope values in the topographic profile (fig. 4c) and is located at the northeastern top of the hill. in top view, the scarp has a subcircular shape, typical of rotational landslides. moreover, it represents the boundary between the bedrock units of the hilly top and the slope deposits (fig. 6a,b). the maximum thickness of the landslide deposits, based on our field observations, and the numerical analysis of mancini et al. (2001) should be approximately 15 m. a large landslide terrace was detected just below the scarp. altogether, the above features represent morphological evidence of the large gravitational movements that occurred in 1881. 4.2. description and chronology of the cfl event two main landslide episodes occurred in 1881, strongly modifying the eastern hillslope of castel frentano and causing heavy damages to the old village (fig. 5a). as already mentioned, the main event occurred on the 31st of july, 1881; then, on the 10th of september, 1881, an earthquake reactivated the landslide (savarese et al., 2011). historical information helped reconstructing the evolution of the gravitational processes and the chronology of events that occurred before the main landslide event. this event was first described by enrico niccoli (niccoli, 1882), an engineer who was delegated by the italian royal geological committee to compile a report on it. therein, information on the cfl is presented critically and methodically. “during the afternoon of the 31st of july a widespread groundfall began to occur on the eastern hillslope and slide northeastwards, towards the bottom of the feltrino creek. the movement continued until night, leading to a very large landslide, which was about 1-km long and 500-m wide. the displaced mass is estimated to be about 9 million m3 […]. the ground surface 37 damages caused in castel frentano in 1881 by a landslide and an earthquake. fig. 5 (a) googleearthtm view of the castel frentano landslide (cfl); (b) historical photograph of the landslide taken in 1881 (from the historical archive of the castel frentano municipality); (c) the cfl today. the green arrow indicates the santo stefano protomartire church. the dashed blue line in (c) indicates the portion of the feltrino creek below the hillslopes. 38 racano s. et al. collapsed at about 30 m close to the village, while it swelled in the lower part of the valley; the landslide […], due to the presence of widespread and deep transverse cracks, was similar in shape to a glacier or even to a lava flow […].” (translated from niccoli, 1882). this morphological description of the event reflects the characteristics of a rotational landslide, which are confirmed by a photo shot after the event and by the present-day morphology of the hillslope (fig. 5b,c). niccoli (1882) also compiled a geological description of the hill and drew a scheme of the landslide section, which is similar to that obtained based on our geomorphological map: the landslide cuts and exposes the bedrock at the hilltop (fig. 6a,b). niccoli (1882) reported that the hill was composed of “tertiary-pliocene units” with subhorizontal strata, mainly composed of grey-yellow marly clays, often interbedded with sands. the sands locally showed a “marly-calcareous” cement, but were generally consolidated “and formed an 8-m thick bank at the top of the hill, in correspondence of the urban centre of castel frentano”. a detailed description of the catastrophic events can be found in the historical documents of castel frentano’s city council. one of them, produced on the 9th of september, 1881 (i.e. the day preceding the earthquake), reports some instability phenomena that had fig. 6 (a) landslide profile by niccoli (1882) and section of fig. 6b; (b) landslide profile interpreted from the geological-geomorphological map (fig. 4a). already affected the village before the main event of the 31st of july, 1881: “[…] last june, major clues of instability (depressions in the orientale street and in its proximity, and cracks in the surrounding fields) alerted us and we asked for assistance to an engineer.” [translated from city council historical documents, folder b9, file f168, 1861-1881]. a document produced on the 5th of august, 1881 (city council historical document, folder b9, file f168, 1861-1881) declares instead that 469 citizens suffered the consequences of the landslide damages (including the complete destruction of their houses), which mainly affected residential buildings (fig. 7). after the main event, no further significant landslide movements were recorded until the earthquake of the 10th of september, 1881. in his report, niccoli (1882) wrote: “[…] the movements did not stop after the first one, because the earthquake induced the falling of other slices of soil and continued to damage the area […]”. (translated from niccoli, 1882). several damages affected the portion of village closest to the landslide scarp after the earthquake event, as reported by bucci (1990) in his memoriae (provided by the personal communication of ferrante and paione families). he stated that, after the earthquake, the pre-existing landslide damaged the most picturesque part of the village, but there were no casualties. other documents found in the italian state archive of chieti section lanciano and in that of pescara, as well as information collected from newspapers found at the chieti library, reveal that also buildings far from the landslide suffered damages induced by the earthquake: “numerous houses that were not in the landslide area were strongly damaged and a lot of people were injured, although there were no victims” (telegram to the prefect of chieti, available in the state archive of chieti-section lanciano, sottoprefettura, folder 20, file 115, 9th of october, 1881); “in castel frentano, a lot of houses outside of the landslide zone were damaged […]” (la gazzettina di chieti, 15th of october, 1881). 4.3. landslide genesis although massive slope movements are usually related to rainfalls and/or earthquakes, there is no evidence that such triggering phenomena can be attributed to the 1881 landslide. the first evidence of instability was observed in june, while the collapse of the hillslope and of the eastern part of castel frentano occurred at the end of july. no detailed climatic records were found for the period of interest (even after consulting the avi catalogue); moreover, no strong rainfalls, nor unusually wet summers or wet preceding months are mentioned in the available historical documents for 1881 and previous years. this absence of information is of great significance. in fact, the landslide events that occurred in 1881 had a large resonance, as highlighted by the numerous “media reports” of that time and descriptions of the event that have supported hypotheses on its origin (see next paragraphs of this section). overall, the lack of reference in all documents to anomalously frequent and abundant summer rainfalls (which would have provided an easy explanation for the catastrophe) suggests that the slide processes were likely not triggered by excessive rainfall. apart from extreme events, the available data (fig. 8) were searched for irregular trends in the cumulative rainfalls related to specific climatic periods. for the investigated area (the territory of lanciano) two climatic series can be discussed: they refer to the periods 18341843 and 1886-1902, and include the number of rainy days per month. the number of rainy days per year ranged approximately between 60-100. figure 8 shows a plot based on data collected between 1834-1842: the average number of rainy days per year varied generally between 95-100; however, a low number of rainy days (only 62) was registered in 1843. no data are available for the period 1842-1885. between 1886-1895, the average number of rainy days per year was about 70; then, between 1895-1902, this value increased to 95-100. daily rainfall data were also obtained for the period 1886 -1902: the cumulative number of rainy days during the summer (i.e. the season during which the cfl occurred) of those years was plotted (fig. 8). the resulting diagram shows a regular contribution of summer months to the total yearly rainy days. additional data from the fucino basin (giraudi, 1990), an intermontane depression in the abruzzo apennines (about 70 km west of castel frentano), indicate a decrease in rainfall between 18551862, when slope instability significantly increased in the area (see next paragraphs of this section). notably, the average annual rainfall in central italy was quite regular between 1850-1905 (maugeri et al., 2004). overall, no climate anomalies causing periods of heavy rain can be inferred for the abruzzo region and central italy in general during the decades of interest. some historical documents indicate that the source of instability might have been of completely different nature. niccoli (1882) wrote: “[…] concerning the description of the phenomenon, […] it was mainly due to the nature of the terrain that constitutes the hillslope, which led to a slow but continuous slope movement […]” (translated from niccoli, 1882). in summary, this author related the origin of the landslide to the characteristics of the soil and shallow subsoil. he also provided some critical details about land use while inferring the causes of the landslide: “[…] before 1815, the collapsed hillslope was covered by trees. later, however, the expansion of agricultural activities here and elsewhere encouraged ploughing […] and, soon, [it triggered] some ground movements, mostly on the higher portion of the hillslope. nevertheless, the ploughing continued, and increasingly larger and numerous movements occurred from 1831 onwards, causing the fall of several houses. deforestation occurred mostly after 1860 and the landslide area continued to increase […] until, in june 1881, the maximum level of hazard was reached […]” (translated from niccoli, 1882). the first reference to a landslide along the eastern hillslope of castel frentano has been found in a city council document dated 1861. this document highlighted the evacuation of the population from contrada ripitelli (fig. 7a), which was on the eastern slope of castel frentano’s hill before being destroyed by the landslide in 1881 (city council documents, folder b9, file f168, 1861-1881, 17th of february, 1861). after 1861, 39 damages caused in castel frentano in 1881 by a landslide and an earthquake. 40 racano s. et al. fig. 7 (a) planimetry of the centre of castel frentano, possible location of contrada ripitelli and comparison between the (b) present-day and (c) pre-landslide urban fabrics; (d), (e), (f) historical photos, in which the numbers indicate the damaged buildings (as reported in the map (c)). the area of slope instability on the eastern flank of the relief was known as “the landslide”. these conditions led to the destruction of about 100 buildings by 1868. in the documents of the city council, building crumbling and collapse were attributed to the erosional action of the feltrino creek, flowing along the lower portion of the hill. this process “sank and destroyed many valuable houses located in the village” (city council documents, folder b9, file f168, 1861-1881, 8th of november, 1868). these notes report also the erosional activity of the feltrino creek at the base of the hillslope as an additional factor contributing to the evolution of the landslide. regarding the phenomenon of water seepage in the subsoil, a document of the city council mentions undetailed problems in the drinking water supply to the village. drinkable water was lacking, creating inconveniences to the population. this issue was linked to a malfunctioning of the shallow aqueduct, which would have been penetrated by roots and filled with waste. apparently, water was spilling from the aqueduct and, hence, could not reach the buildings in the village (city council documents, folder b9, file f168, 1861-1881, 5th of august, 1863). no further information is available about this issue and we could not find any map of the aqueduct, nor any reference to its position. the potential role of water seepage and land use activities in the activation of the landslide are discussed in section 5. 5. discussion overall, the available information shows that the cfl was a peculiar event: no major natural triggering factors can be invoked for the widespread slope mass movement that struck castel frentano. in italy, catastrophic landslides are usually associated to heavy rainfalls, as in the case of valtellina in 1987 (alexander, 1988) and sarno in 1998 (cascini et al., 2011), or to seismic crises, as in the case of irpinia in 1980 (del gaudio & wasowski, 2004) and molise in 2002 (which triggered the salcito landslide; bozzano et al., 2008). rainfalls and climatic conditions are generally considered potential triggers of landslide events; however, no evidence of a significant role of these factors in the evolution of the cfl raised from the available information. the period in which the catastrophe occurred was not anomalous in terms of rainfall amount, and local historical sources do not mention the occurrence of heavy rainfalls before the slope collapse. mancini et al. (2001) investigated the response of periadriatic hillslopes to seismic loads, concluding that significant slope movements would tend to involve mainly colluvial deposits saturated by a water table (situated at least 4 m above the colluvium/clays contact surface). however, these authors erroneously considered the cfl to have been seismically induced: the available historical documents have revealed instead that, on the 10th of september, 1881, the earthquake led simply to the reactivation of an already displaced mass. regarding the seismicity characterizing the period of interest, the shock that occurred on the 14th of august, 1871 (i.e. the only earthquake reported in the catalogue preceding the paroxysmal gravitational event; fig. 3a) should not be considered as a potential cause of the landslide. in fact, (1) it occurred ten years after the beginning of slope instability and ten years before the main landslide event; (2) shaking was insignificant, due to the low magnitude of the seismic event (moment magnitude = 3.8; rovida et al., 2022) and as testified by the lack of associated damage in the territory struck by the shock: the effects in the zone of castel frentano were well below the damage threshold (the mcs intensity was 4 in the nearby town of lanciano; locati et al., 2022). beyond these considerations, it is well known that changes in land use practices, whether conditioned by natural events or human choices, can influence local and regional slope stability (sidle et al., 1985; wasowski, 1998; glade, 2003; sidle & ochiai, 2006; wasowski et al., 2010). an illuminating case of a landslide outside of italy that did not depend on climatic factors is that of the thompson river valley (british columbia, us). there, large instability phenomena occurred atop or within silt-clay units, triggered by the irrigation of benchlands above the river (clague & evans, 2003). the cfl case has some points in common with that of 41 damages caused in castel frentano in 1881 by a landslide and an earthquake. fig. 8 rainy days per year between 1834-1901 (from “annali civili del regno di napoli”, state archive of chieti-lanciano) and rainfall rates in central italy (maugeri et al., 2004) and in the fucino area (giraudi, 1990). the thompson river valley. our data revealed that the geological characteristics (i.e. the occurrence of clays, sands and colluvium) of castel frentano’s hill and the geomorphological processes (i.e. the narrow incisions created by stream channels) affecting it predispose the area to landslide phenomena. the available information also suggests that niccoli (1882) was probably right in invoking anthropogenic activity as one of the key factors that triggered the catastrophic event. indeed, the growing need for agricultural fields in italy is known to have caused massive deforestations in all parts of the italian peninsula from the second half of the 18th century (vecchio, 1974). this has resulted in a widespread growth of slope instability phenomena (bevilacqua, 1996). historical sources have revealed that movements along the eastern castel frentano hillslopes started to occur with the initiation of deforestation along the slope, which was linked to the expansion of agricultural activities. deforestation, combined with the agricultural usage of the hillslope, the geology of the area and the erosion activity of the feltrino creek, should have led to a progressive loss of hillslope stability, ultimately inducing landsliding. additional aspects that may have led to landsliding include water leaking from the aqueduct (described by the city council in 1863). in fact, although the location of the aqueduct could not be reconstructed and no clear evidence was collected on the role of water seepage in the landslide paroxysmal evolution, a potential contribution of this phenomenon cannot be excluded. in any case, water leaking would have had a secondary role compared to the intensive agricultural land exploitation that was affecting the area around 1881. overall, the analysed historical documents allowed to reconstruct a sequence of landslides that, after 1860 (i.e. when the deforestation process was completed), started to slowly move towards the hilltop. this movement would have produced the first important damage to buildings in castel frentano in 1868, and would have led to the complete destruction of part of the village in 1881. nowadays, the eastern slope of castel frentano’s hill has still a poor tree coverage and is exploited for agricultural activities (fig. 5a,c); moreover, it is still affected by landsliding (as revealed by our geomorphological survey). although landsliding presently occurs on the eastern hillslope, it is predominantly of the rotational type and is much smaller in size compared to the paroxysmal event that took place in 1881. in fact, present landslides predominantly affect the colluvium and cfl accumulation, and none of them have been capable of cutting and exposing the bedrock on the eastern or western slopes of the hill. castel frentano’s case is not the only one in the abruzzo region in which landslides have had a probable anthropogenic origin. according to historical reports, the instability of gessopalena’s hill (about 17 km sw of castel frentano; fig. 1) can be also attributed to the combined action of deforestation and water seepage (galadini, 2016). in this case, however, the geological setting is completely different: the old village of gessopalena (now abandoned) was settled on a small gypsum relief, while the adjacent valleys are characterized by highly erodible clays. notably, 19th century documents (galadini, 2016) report that: (1) numerous wells in the houses of gessopalena were leaking water into the gaps of the subsoil and (2) the underlying valleys were experiencing continuous deforestation. these factors would have triggered the collapse of gypseous boulders from gessopalena’s hill and mass flows in the underlying clayey valleys (i.e. gravitational phenomena different from those of castel frentano). the resulting instability became a threat for the old village of gessopalena during the 19th century, although interventions were carried out to limit the damages: hydraulic works were done to optimize the water regime and valleys previously denuded were reforested (galadini, 2016). 6. conclusions the cfl is an example of a natural catastrophe mainly driven by human activity that caused the loss of cultural heritage. although castel frentano’s hill was already predisposed to slope mass movements due to its geological and geomorphological conditions (i.e. weak lithologies and stream linear incisions), deforestation activities and the consequent agricultural use of the eastern hillslope (possibly combined with water seepage from the aqueduct) may have been the primary causes of the cfl genesis. the collected documents suggest that landslide movement may have begun in the lower part of the hillslope following deforestation and may have been driven by the incision activity of the feltrino creek. then, the landslide may have progressively migrated upwards along the landslide scarp until the paroxysmal event that involved the village on the 31st of july, 1881, leading to the collapse of historical buildings. based on coeval documents and information on rainfall events, the following hypotheses can be considered remote: (1) the main landslide event may have been preceded by a period of heavy atmospheric precipitations and (2) a period of anomalous climate may have occurred during the decades of landslide trigger and evolution. despite the large volume of documents mentioning the main landslide event and evaluating its origin, none of them mentions the occurrence of exceptional rainfalls during or before 1881, although this would have represented the simplest explanation. this suggests that climatic factors and weather conditions likely did not play a major role in triggering the main landslide event. in addition, historical evidence of the paroxysmal landslide evolution preceding the 1881 earthquake and the absence of any reference in historical documentation to seismic events in the area of castel frentano shortly before the main landslide event indicate that earthquakes unlikely caused it. rather, a 5.4-magnitude seismic event, which occurred about 40 days after the main landslide event, should have worsened the already critical situation of castel frentano. historical sources clearly described the reactivation of the landslide after this earthquake. in conclusion, the cfl case exemplifies what the italian landscape has experienced since the second half of the 18th century: an increase of landslide occurrence following the expansion of agricultural land exploitation. past studies stressed the relationship between wide 42 racano s. et al. spread anthropogenic changes of the landscape during this period and an increase in landslide and flood fatalities (guzzetti et al., 2005). we infer that the case of castel frentano may be suitably included in datasets aimed at explaining the above relationship. acknowledgements a special thanks to the meteorologist angelo ruggeri for his contribution in providing the climatic record data of the 19th century for the lanciano area. references agnesi v., carrara a. macaluso t. monteleone s., pipitone g., sorriso-valvo m. (1983) elementi tipologici e morfologici dei fenomeni di instabilità dei versanti indotti dal sisma del 1980 (alta valle del sele). geologia applicata e idrogeologia, 18 (1), 309-341. alcántara-ayala i., esteban-chávez o., parrot j.f. (2006) landsliding related to land-cover change: a diachronic analysis of hillslope instability distribution in the sierra norte, puebla, mexico. geomorphology and land degradation, 65(2), 152165. doi: 10.1016/j.catena.2005.11.006 alexander d. (1988) valtellina landslide and flood emergency, northern italy, 1987. disasters, 12(3), 212-222. doi: 10.1111/j.1467-7717.1988.tb00671.x arca d., kutoğlu h.ş., becek k. (2018) landslide susceptibility mapping in an area of underground mining using the multicriteria decision analysis method. environmental monitoring and assessment, 190(12), 725. doi: 10.1007/s10661-018-7085-5 beguería s. (2006) changes in land cover and shallow landslide activity: a case study in the spanish pyrenees. geomorphology, 74(1), 196-206. doi: 10.1016/j.geomorph.2005.07.018 bevilacqua p. (1996) tra natura e storia: ambiente, economie e risorse in italia. donzelli editore, roma, italy, 90-112 bigi s., cantalamessa g., centamore e., didaskalou p., miccarelli a., nisio s., pennesi t., potetti m. (1997) the periadriatic basin (marche-abruzzi sector, central italy) during the plio-pleistocene. giornale di geologia, 59, 245-259. bozzano f., lenti l., martino s., paciello a., scarascia mugnozza g. (2008) self-excitation process due to local seismic amplification responsible for the reactivation of the salcito landslide (italy) on 31 october 2002. journal of geophysical research, 113(b10), b10312. doi: 10.1029/2007jb005309 brunsden d. (1985) landslide types, mechanisms, recognition, identification. proceedings of landslides in the south wales coalfield, 1-3 april 1985, polytechnic of wales, pontypridd, uk, 19-28. buccolini m., pasculli a., sciarra n. (2000) castelfrentano landslide (abruzzo central italy). in: proceedings of the 8th congress of the international association for engineering geology and the environment (iaeg), volume vi. aa balkema publishers, rotterdam, netherlands, 4019-4027. cascini, l., cuomo, s., della sala, m. (2011) spatial and temporal occurrence of rainfall-induced shallow landslides of flow type: a case of sarnoquindici, italy. geomorphology, 126(1), 148-158. doi: 10.1016/j.geomorph.2010.10.038 c e n t a m o r e e . , n i s i o s . , p r e s t i n i z z i a., scarascia mugnozza g. (1996) evoluzione morfodinamica e fenomeni franosi nel settore periadriatico dell’abruzzo settentrionale. studi geologici camerti, 14, 9-27. doi: 10.15165/studgeocam-794 centamore e., nisio s. (2003) effects of uplift and tilting in the central-northern apennines (italy). quaternary international, 101-102, 93-101. doi: 10.1016/s1040-6182(02)00092-7 centamore e., rossi d. (2009) neogene-quaternary tectonics and sedimentation in the central apennines. italian journal of geosciences, 128(1), 7388. chiodo g., dramis f., gervas a., guerra i., sorrisovalvo m. (1999) frane sismo-indotte e pericolosità di sito: primi risultati dello studio degli effetti di forti terremoti storici in calabria centrosettentrionale. atti del 18° convegno annuale del gruppo nazionale di geofisica della terra solida, roma, italy, 1-10. clague j.j., evans s.g. (2003) geologic framework of large historic landslides in thompson river valley, british columbia. environmental and engineering geoscience, 9(3), 201-212. doi: 10.2113/9.3.201 crandell d.r., miller c.d., glicken h.x., christiansen r.l., newhall c.g. (1984) catastrophic debris avalanche from ancestral mount shasta volcano, california. geology, 12(3), 143-146. doi: 10.1130/0091-7613(1984)12<143:cdafam> 2.0.co;2 dapples f., lotter a.f., van leeuwen j.f.n., van der knaap w.o., dimitriadis s., oswald d. (2002) paleolimnological evidence for increased landslide activity due to forest clearing and land-use since 3600 cal bp in the western swiss alps. journal of paleolimnology, 27(2), 239-248. doi: 10.1023/a:1014215501407 del gaudio v., wasowski j. (2004) time probabilistic evaluation of seismically induced landslide hazard in irpinia (southern italy). soil dynamics and earthquake engineering, 24(12), 915-928. doi: 10.1016/j.soildyn.2004.06.019 del nobile m. (2011) da guasto superiore a castel frentano. bibliografica castel frentano. de nardis r., garbin m., lavecchia g., pace b., peruzza l., priolo e., romanelli m, romano m.a., visini f., vuan a. (2011) a temporary seismic monitoring of the sulmona area (abruzzo, italy) for seismotectonic purposes. bollettino di geofisica teorica ed applicata, 52, 651-666. doi: 10.4430/bgta0026 douglass j., dorn r.i., gootee b. (2005) a large landslide on the urban fringe of metropolitan phoenix, arizona. geomorphology, 65(3), 321-336. 43 damages caused in castel frentano in 1881 by a landslide and an earthquake. doi: 10.1016/j.geomorph.2004.09.022 fedeski m., gwilliam j. (2007) urban sustainability in the presence of flood and geological hazards: the development of a gis-based vulnerability and risk assessment methodology. cities and sustainability, 83(1), 50-61. doi: 10.1016/j.landurbplan.2007.05.012 galadini f. (2016) urgenza geologica e spinte sociali nelle delocalizzazioni del xx secolo in abruzzo. in: marsica 1915 l’aquila 2009. un secolo di ricostruzioni (ed. by galadini f., varagnoli c.). gangemi editore, roma, 69-114. gariano s.l., petrucci o., rianna g., santini m., guzzetti f. (2018) impacts of past and future land changes on landslides in southern italy. regional environmental change, 18(2), 437-449. doi: 10.1007/s10113-017-1210-9 giraudi c. (1990) le variazioni di livello del lago del fucino (abruzzo) nel periodo 1783-1862: implicazioni climatiche. il quaternario, 3(2), 167-174. glade t. (2003) landslide occurrence as a response to land use change: a review of evidence from new zealand. geomorphic responses to land use changes, 51(3), 297-314. doi: 10.1016/s0341-8162(02)00170-4 guzzetti f, salvati p., stark c.p. (2005) evaluation of risk to the population posed by natural hazards in italy. in: landslide risk management (ed. by hungr o., fell r., couture r., eberhardt, e.). taylor & francis group, london, 381-389. guzzetti f., mondini a.c., cardinali m., fiorucci f., santangelo m., chang k.t. (2012) landslide inventory maps: new tools for an old problem. earth-science reviews, 112 (1-2), 42-66. doi: 10.1016/j.earscirev.2012.02.001 keefer d.k. (1984) landslides caused by earthquakes. gsa bulletin, 95(4), 406-421. doi: 10.1130/0016-7606(1984)95&amp;amp;lt406: lcbe&amp;amp;gt;2.0.co;2 lichkov l.s. (1938) on the question of the regime of landslides in the vicinity of the city of kiev and its environs. geologichnyy zhurna, 4, 145-194. locati m., camassi r., rovida a., ercolani e., bernardini f., castelli v., caracciolo c.h., tertulliani a., rossi a., azzaro r., d’amico s., antonucci a. (2022) database macrosismico italiano (dbmi15), versione 4.0. istituto nazionale di geofisica e vulcanologia (ingv). doi: 10.13127/dbmi/dbmi15.4 mancini b., martino s., prestininzi a., rischia i., romeo r. (2001) studio delle condizioni di stabilità dei versanti a seguito di forti terremoti: applicazione ad un’area tipica dell’appennino centrale. memorie della società geologica italiana, 56, 83-98. mandasari j., arifin m., ali m. (2016) settlement arrangement based on landslide mitigation (case study: capagallung, west bacukiki district, city of parepare). cities 2015: intelligent planning towards smart cities, 227, 442-450. doi: 10.1016/j.sbspro.2016.06.099 mathewson c.c., keaton j.r., santi p. m. (1990) role of bedrock ground water in the initiation of debris flows and sustained post-flow stream discharge. environmental and engineering geoscience, 27(1), 73-83. doi: 10.2113/gseegeosci.xxvii.1.73 maugeri m., brunetti m., buffoni l., fassina a., iafrate l., lentini g., mangianti f., masiello c., mazzucchelli e., monti f., nanni t., pastorelli r., torquati c. (2004) acquisizione, esame critico ed analisi di serie storiche italiane per lo studio delle variazioni del clima: relazione tecnicoscientifica 2. anno. relazione finale per il secondo anno del progetto finalizzato climagri, università degli studi di milano, istituto di fisica generale applicata, milano, italy. mcinnes r.g. (1996) a review of coastal landslide management on the isle of wright, u.k. in: proceedings of 7th international symposium on landslides, trondheim, norway (ed. by senneset k.). taylor and francis, london, 301-307. nature notes (1881) notes. nature, 24(622), 517-520. doi: 10.1038/024517a0 niccoli e. (1882) la frana di castel frentano. regio comitato geologico d’italia. racano s., fubelli g., centamore e., bonasera m., dramis f. (2020) geomorphological detection of surface effects induced by active blind thrusts in the southern abruzzi peri-adriatic belt (central italy). geografia fisica e dinamica quaternaria, 43, 3-13. doi: 10.4461/gfdq.2020.43.1 rovida a., locati m., camassi r., lolli b., gasperini p., antonucci a. (2022) catalogo parametrico dei terremoti italiani (cpti15), versione 4.0. istituto nazionale di geofisica e vulcanologia (ingv). doi: 10.13127/cpti/cpti15.4 salvati p., balducci v., bianchi c., guzzetti f., tonelli g. (2009) a webgis for the dissemination of information on historical landslides and floods in umbria, italy. geoinformatica, 13(3), 305-322. doi: 10.1007/s10707-008-0072-1 savarese f., tertulliani a., galadini f. (2011) le fonti sul terremoto del 10 settembre 1881 in provincia di chieti: revisione critica e nuove conoscenze. bollettino della deputazione abruzzese di storia patria, 102, 155-179. scioli m. (1981) castel frentano: appunti di storia. officine grafiche anxanum, lanciano. scioli m. (1998) castelnuovo: una rifondazione del tardo medioevo. bullettino della deputazione abruzzese di storia patria / deputazione di storia patria per gli abruzzi, 37-76. sidle r.c., ochiai h. (2006) landslides: processes, prediction, and land use. water resources monograph, 18. american geophysical union, washington d.c., pp. 312. sidle r.c., pearce a.j., o’loughin c.l. (1985) hillslope stability and land use. water resources monograph, 11. american geophysical union, washington d.c., pp. 140. smyth c.g., royle s.a. (2000) urban landslide hazards: incidence and causative factors in niterói, rio de janeiro state, brazil. applied geography, 20(2), 95-118. doi: 10.1016/s0143-6228(00)00004-7 44 racano s. et al. soeters r., van westen c.j. (1996) slope instability recognition, analysis, and zonation. in: landslide: investigations and mitigation special report (ed. by turner a.k., schuster r.l.). transportation research board, washington d.c., 247, 129-177. suarez j. (1996) erosion induced landslides in tropical environments. in: proceedings of 7th international symposium on landslides (ed. by senneset k.). trondheim, norway. taylor and francis, london, 301-307. tropeano d., turconi l. (2004) using historical documents for landslide, debris flow and stream flood prevention. applications in northern italy. natural hazards, 31, 663-679. doi: 10.1023/b:nhaz.0000024897.71471.f2 van westen c.j., van asch t.w.j., soeters r. (2006) landslide hazard and risk zonation—why is it still so difficult? bulletin of engineering geology and the environment, 65(2), 167-184. doi: 10.1007/s10064-005-0023-0 vecchio b. (1974) il bosco negli scrittori italiani del settecento e dell’età napoleonica. einaudi, torino. wasowski j. (1998) understanding rainfall-landslide relationships in man-modified environments: a case-history from caramanico terme, italy. environmental geology, 35(2-3), 197-209. doi: 10.1007/s002540050306 wasowski j., lamanna c., casarano d. (2010) influence of land-use change and precipitation patterns on landslide activity in the daunia apennines, italy. quarterly journal of engineering geology and hydrogeology, 43(4), 387-401. doi: 10.1144/1470-9236/08-101 zope p.e., eldho t.i., jothiprakash v. (2016) impacts of land use-land cover change and urbanization on flooding: a case study of oshiwara river basin in mumbai, india. catena, 145, 142-154. doi: 10.1016/j.catena.2016.06.009 45 damages caused in castel frentano in 1881 by a landslide and an earthquake. ms. received: january 21, 2022 revised: april 6, 2022 accepted: april 19, 2022 available online: may 12, 2022 46 sess 3_14022011_edi as (3).pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 the early and middle pleistocene sabertoothed cats in europe: taxonomy, biochronology and paleoecology. raffaele sardella & dawid adam iurino dipartimento di scienze della terra, università “sapienza”, roma corresponding author: r. sardella <raffaele.sardella@uniroma1.it> abstract: sardella r. & iurino d., the early and middle pleistocene sabertoothed cats in europe: taxonomy, biochronology and paleoecology. (it issn 0394-3356, 2011) two different groups of sabertoothed cats (machairodontinae, felidae, mammalia) characterized the early pleistocene terrestrial ecosystems in europe: homotherium and meganteron. the taxonomy of these felids is matter of debate, and their importance in biochronology and paleocology is analyzed. in europe megantereon become exctinct at the end of early pleistocene, while homotherium seems to survive until the late pleistocene. riassunto: sardella r. & iurino d., a. i felidi macairodonti nel pleistocene inferiore e medio in europa: questioni tassonomiche, biocronologia, paleoecologia. (it issn 0394-3356, 2011) gli ecosistemi continentali europei del pleistocene inferiore sono caratterizzati dalla presenza delle cosiddette “tigri dai denti a sciabola” (machairodontinae, felidae, mammalia), rappresentate da due taxa che rispecchiano due diversi tipi di adattamento: homotherium and meganteron. la sistematica di questi felidi è molto dibattuta e sarà discussa insieme all’importanza biocronologica e paleoecologica di questi carnivori. in europa megantereon si estingue alla fine del pleistocene inefriroe, mentre homotherium diviene molto raro e sopravvive sino al pleistocene superiore. key words: biochronology, mammals, dispersal events, paleoecology, terrestrial ecosystems parole chiave: biocronologia, mammiferi, eventi di dispersione, paleoecologia, ecosistemi continentali among the top predators sabertoothed cats (machairodontinae, felidae) were dominant in the early pleistocene terrestrial ecosystems of europe. two genera, corresponding to two different lineages and morpho-functional adaptations, characterized the villafranchian faunal assemblages: homotherium and megantereon. the taxonomy of these felids is based mainly on craniodental features and, despite an increasing number of localities provided a larger amount of fossils, including also postcranial bones, the specific attribution of such material seems to be a quite complicated matter. homotherium had unique craniodental as well as postcranial adaptations distinguishing it (and all the forms referable to the homotherinii tribe) from other machairodontinae. homotherium evolved from derived forms of the machairodus lineage and forms referable to the late miocene paraphyletic species complex amphimachirodus can be considered its immediate ancestors (werdelin l. & sardella r., 2006). the timing of the amphimachairodus-homotherium transition is still unclear. the features of homotherium suggest a unique ecomorphology and behaviour. it was a lion sized felid with crenulated teeth; upper canines were elongated, flat and serrated. incisors were powerful, stronger than in any living felid. the limb proportions of homotherium were very different than those of any living felid. the forelimbs were elongated, while the hindlimbs were shorter and quite stout. a number of different species have been proposed for the european homotherium (h. hungaricus, h. sainzelli, h. crenatidens, h. latidens, h. moravicum) mainly based on the size and on the upper canine morphology. at present, many authors refers all the european specimens to homotherium latidens, nonetheless, the earliest european specimens show peculiar craniodental characters (longer and narrower upper canines, stronger anterior part of the mandible, with convex labial surface) that can be considered ‘‘archaic’’ features. thus, the early villafranchian specimens should be referred to the species homotherium nestianus that has been recorded at roca neyra (france), pievefosciana (garfagnana, tuscany) and sammezzano (upper valdarno, tuscany) (sardella r., 1994 and references therein). homotherium latidens characterized the late villafranchian faunal assemblages and became very rare in the middle pleistocene; it seems to survive in northwestern europe until the late pleistocene (reumer j. f. w. et al., 2003). finally, the presence of a preparastyle in the upper carnassial characterizes some galerian large sized homotherium specimens. in the past some of these specimens were referred to homotherium moravicum (stranska skala, moravia; hundsheim, austria) (sardella r., 1994), but in many following studies this species has been referred to h. crenatidens 170 171 170 ms. received: testo ricevuto il and/or h. latidens. fossils sharing the “h. moravicum morphology” in the upper carnassials have been found also in some latest early pleistocene sites in northern italy (domegliara selvavecchia, and other unpublished localities). it is possible that the occurrence of a separate species has be reconsidered. the genus megantereon belongs to the smilodontini tribe and includes plio-pleistocene jaguarsized, short limbed, dirk-toothed felids with a stoutly built postcranial skeleton, in which the robust distal limb bones indicate an ambushing hunting method. the earliest occurrence of megantereon in europe in recorded in the middle pliocene of les etouaires, france (possibly 3.5 ma, but not older than 2.5), the latest occurrence of the taxon is at untermassfeld (thuringia, germany) (sardella r., 1994 and references therein, hemmer h., 2001). taxonomy and evolution of this felid have been discussed in several papers issued during recent decades and different interpretations have been provided. all the authors agree to refer pliocene european specimens to m. cultridens. different interpretations are proposed for early pleistocene european forms. turner considered the differences recorded into the eurasian and african sample of megantereon as due to sexual dimorphism, comparing the data to those of the living leopard. other authors claimed a convergent evolution of the european samples of m. cultridens with the african m. whitei, due to the paleoclimate and the paleoenvironmental conditions occurring during the earliest part of the pleistocene. they named this form m. cultridens adroveri (hemmer h., 2001 and references therein). sardella r. (1998) suggested the use of open taxonomy including the early pleistocene european specimens in megantereon ex gr. cultridens (advanced form). recently, the attribution to megantereon whitei was supported by further data and adopted by many authors (palmqvist p. et al., 2007). the dispersal of m. whitei into europe probably occurred concurrently with other african species following the levantine corridor. in europe this taxon was found in venta micena (spain), monte argentario, pirro nord (italy) and greece (apollonia) (sardella r. et al., 2008 and references therein). references hemmer h. (2001) die feliden aus dem epivillafranchium von untermaßfeld. in: kahlke, r.-d. (ed.), das pleistozän von untermaßfeld bei meiningen (thüringen), teil 3. monographien des römischgermanischen zentralmuseums mainz 40, 699-782. palmqvist p., torregrosa v., pérez-claros j.a., martínez-navarro b. & turner a. (2007) a reevaluation of the diversity of megantereon (mammalia, carnivora, machairodontinae) and the problem of species identification in extinct carnivores. j. vertebr. paleontol. 27, 160–175. reumer j. f. w., rook l., van der borg,k., post k., mol d. & de vos j. (2003) late pleistocene survival of the saber-toothed cat homotherium in northwestern europe. j. vertebr. paleontol., 23(1), 260-262. sardella r. (1994) sistematica e distribuzione stratigrafica dei macairodontini dal miocene superiore al pleistocene, phd dissertation, bologna, firenze, modena and roma “la sapienza” universities, rome 1-137 pp. sardella r. (1998) the plio-pleistocene dirk toothed cat megantereon ex gr. cultridens (mammalia, felidae, macharodontinae) with comments on taxonomy, origin and evolution. n. jahrb. geol. paläontol. abh. 207, 1– 36. sardella r., petrucci m. & rook l. (2008) the african species megantereon whitei from the early pleistocene of monte argentario (south tuscany, central italy). c. r. palevol., 7, 601-606. werdelin l. & sardella r. (2006) the “homotherium” from langebaanweg, south africa and the origin of homotherium. palaeontographica, abt. a, 277 (1-6), 123-130  fig. 1, megantereon whitei skulls from early pleistocene italian localities. g1 from pirro nord, apulia (up) and arg31 from monte argentario, tuscany (lower, stored at the istituto italiano di paleontologia umana, roma). scale bar: 1 cm. megantereon whitei. crani provenienti da siti italiani del pleistocene inferiore. 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can be opened with acrobat and adobe reader 5.0 and later.) >> /namespace [ (adobe) (common) (1.0) ] /othernamespaces [ << /asreaderspreads false /cropimagestoframes true /errorcontrol /warnandcontinue /flattenerignorespreadoverrides false /includeguidesgrids false /includenonprinting false /includeslug false /namespace [ (adobe) (indesign) (4.0) ] /omitplacedbitmaps false /omitplacedeps false /omitplacedpdf false /simulateoverprint /legacy >> << /addbleedmarks false /addcolorbars false /addcropmarks false /addpageinfo false /addregmarks false /convertcolors /converttocmyk /destinationprofilename () /destinationprofileselector /documentcmyk /downsample16bitimages true /flattenerpreset << /presetselector /mediumresolution >> /formelements false /generatestructure false /includebookmarks false /includehyperlinks false /includeinteractive false /includelayers false /includeprofiles false /multimediahandling /useobjectsettings /namespace [ (adobe) (creativesuite) (2.0) ] /pdfxoutputintentprofileselector /documentcmyk /preserveediting true /untaggedcmykhandling /leaveuntagged /untaggedrgbhandling /usedocumentprofile /usedocumentbleed false >> ] >> setdistillerparams << /hwresolution [2400 2400] /pagesize [612.000 792.000] >> setpagedevice imp.cattuto_gregori& condizioni geomorfologiche e stabilita’ dell’acropoli di tarquinia vecchia c. cattuto 1, l. gregori 1, m. milano 2 & s. rapicetta 1 1 dipartimento di scienze della terra università degli studi di perugia 2 collaboratore esterno piazza università, 1 06123 perugia cattuto@unipg.it; lucilia@unipg.it; silviarap&gmail.com riassunto: c. cattuto, l. gregori, m. milano & s. rapicetta, condizioni geomorfologiche e stabilità dell’acropoli di tarquinia vecchia. (it issn 0394-3356, 2007). circa 5 km a ne dell’odierna tarquinia, si erge una collina la cui sommità è costituita da un’ampia placca calcarea, limitata da una scarpata di circa 5/10 m, che poggia su una potente pila di argille. gli scavi condotti sulla collina hanno messo in luce i resti dell’acropoli dell’antica tarquinia etrusca. tuttavia i numerosi ed interessanti reperti scavati, sono minacciati da vari fenomeni: il cedimento e/o il crollo conseguente la dissoluzione e la carsificazione delle rocce calcaree sulle quali sono fondati, l’erosione il trasporto e la sedimentazione di materiale argillosabbioso operata dal ruscellamento incontrollato delle acque meteoriche, il crollo, per mancanza di sostegno al piede, dei reperti ubicati lungo il bordo della scarpata che limita l’area degli scavi, la frequente variazione del comportamento geomeccanico imposta, dalle pratiche agricole, ai terreni argillosi affioranti al piede della placca calcarea. sulla base delle caratteristiche rilevate, vengono illustrate le condizioni geomorfologiche d’insieme indicando, sommariamente, una serie di possibili interventi tesi a mitigare il pericolo di perdita o di inagibilità dei reperti venuti alla luce in molti anni di scavi e che costituiscono un patrimonio storico artistico e culturale assolutamente unico. abstract: c. cattuto, l. gregori, m. milano & s. rapicetta, geomorphologic conditions and stability of the acropoli “tarquinia vecchia”. (it issn 0394-3356, 2007). in this paper a study about lithologic and geomorphologic characteristics of the archaeological area of tarcxuna, the ancient tarquinia city, in the viterbo district (lazio region, central italy) is presented. the above mentioned archaeological area is situated on the sub-horizontal top of a hill, and it is limited by a high limestone escarpment. in this area, the acropoli, many archaeological objects have been recovered, among them the famous terracotta named "cavalli alati" that comes from the front of the temple. the lithostratigraphical sequence comprises of a high pile of “argille azzurre”, of the low-medium pliocene, then there are two formations of medium-top pliocene, in lateral facies eteropy: “calcare di tarquinia”, limestone of 30 meters of maximum height, and the “sabbie gialle”. the “calcare di tarquinia” (famous also as macco) has a sub-horizontal order and it constitutes the base on which a great part of the acropoli of “tarquinia vecchia” rises and the limestone escarpment that limits the archaeological area too. the limestone is fractured-karst rock and the waters that cross it constitute aquifers that fill small sources at contact with the “argille azzurre”. the clay slides and so remove the support to the limestone escarpment that collapse in blocks also large dimensions. the regression of the escarpment is favoured by the agricultural activity, that is realized carried out until the base of the escarpment. the above mentioned regression affect the “argille gialle” that are over, therefore in more points, there are landslides that induce the collapse of some areas of the tarquinia vecchia town-walls. in order to mitigate the landslide risk in the archaeological area, it is necessary: to stop the rill erosion, to reduce the infiltration, to capture and to remove the waters emerging at the base of the limestone escarpment, to create structures able to control and to support the base of the escarpment. parole chiave: geoarcheologia, geomorfologia, lazio, tarquinia keywords: geoarcheology, geomorphology, lazio region, tarquinia. il quaternario italian journal of quaternary sciences 19(2), 2006 227-232 l’area di studio la città di tarquinia è nota nel mondo per i reperti della civiltà etrusca, in particolare per le numerose tombe (circa 150), decorate con pregevoli pitture, rinvenute a sudest del centro abitato, nella “necropoli di monterozzi” lungo lo spartiacque meridionale del f.so s. savino (fig. 1). lungo il crinale opposto, circa 5 km a ne dall’attuale tarquinia, sorgeva il centro abitato di “tarcxuna”, l’antica tarquinia (ix-viii sec. a. c.), che occupava la sommità subpianeggiante di un colle, limitata da un’alta scarpata calcarea. dell’acropoli restano numerose testimonianze (fig. 2) ed è ancora visibile parte della cinta muraria edificata in blocchi calcarei, che sembra risalire al v sec. a.c. (bonghi j.m., 1986). nell’area più elevata del rilievo, inoltre, sono stati messi in luce i resti di un tempio, l’ara della regina, forse il più grande dell’etruria, dal quale provengono i famosi “cavalli alati” in terracotta che ne decoravano il frontone (fig. 3). 228 c. cattuto et al. caratteristiche geologiche del territorio dopo la crisi salina del miocene, che ha lasciato ampie tracce in alcune aree del tarquinese e della toscana meridionale, la tettonica distensiva, con sistemi di faglie a direzione appenninica, disarticola il margine tirrenico tosco-laziale creando ampi bacini (back basins). l’ingressione marina che si accompagna alla subsidenza di questo territorio raggiunge il massimo approfondimento (fregni et alii, 1985) in due bacini separati dai monti della tolfa: a sud il “bacino romano”, a nord il “bacino del fiora” (fazzini et al i i , 1972). in questi ambienti epimesobatiali, che si estendono ad est fino alla catena appenninica, durante i l pliocene inferiore e medio, si accumulano potenti coltri di sedimenti argillosi (argille di cerveteri nel bacino romano, argille azzurre in quello del fiora). come evidenziato dalla cartografia geologica di fig. 1 e dalla sezione schematizzata in fig. 4, nell’area di tarquinia vecchia affiora una potente formazione di peliti (circa 150 m di spessore), nota come argille azzurre o argille turchine (bellotti et alii, 1993). sopra le argille turchine, in eteropia di facies tra loro, si alternano sabbie gialle e calcareniti (bonadonna f.p., 1967). le sabbie gialle, a luoghi molto addensate e a tratti alternate con sabbie argillose o conglomeratiche, sono ricche in macrofaune (pectinidi, gasteropodi, ostreidi, ecc.) e raggiungono uno spessore massimo di circa 100 m. hanno prevalentemente un colore giallastro e sono riferite al pliocene medio-superiore. allo stesso periodo risalgono le calcareniti che, sfumano talora in calcari sabbiosi giallastri ma che, più spesso, si presentano in strati e banchi compatti e costituiscono i l calcare di tarquinia (chiocchini u., 1990), noto anche con il termine locale di “macco”. la potenza massima di questa formazione non supera i 30 m e, in virtù della sua facile lavorabilità, questa roccia è stata utilizzata, fin dal periodo etrusco, come materiale da costruzione. fig. 1 cartografia geologica schematica dell’area d’indagine: 1. isoipsa, 2. corso d’acqua, 3. strada principale, 4. scarpata, 5. limite litologico, 6. depositi alluvionali recenti, 7. sabbie gialle, 8. calcare di tarquinia (macco), 9. argille azzurre o turchine, sg traccia della sezione geologica schematizzata in fig. 4. geologic map of the study area: 1. contour line, 2. river stream, 3. main road, 4. escarpment, 5. lythologic boundary, 6. recent alluvial deposits, 7. yellow sand, 8. limestone of tarquinia (macco), 9. clay, sg cross section location shown in figure 4. fig. 2 cartografia schematica della superficie del colle, attorno all’isoipsa dei 150 m s.l.m. con la posizione dei resti archeologici più importanti di tarquinia vecchia, messi in luce dagli scavi. scheme map of the most important etruscan ruins of tarquinia; highlighted is the 150m contour line. 229condizioni geomorfologiche e stabilità dell’acropoli ... l’affioramento “a giropoggio” lungo l’intero versante meridionale del colle sul quale sono gli insediamenti di tarquinia vecchia e si identifica con la ripida scarpata, praticamente inaccessibile, alta in media dai 5 ai 15 m che circonda l’intero insediamento dell’antica tarquinia. nell’area di pian della civita le sabbie gialle sono state completamente erose e la sommità del rilievo (superficie strutturale) coincide con il tetto della formazione calcarea (fig. 5). condizioni geomorfologiche e stabilità dei siti archeologici sulle caratteristiche meccaniche delle rocce costituenti il territorio d’indagine si possono avanzare le seguenti considerazioni: 1. le sabbie gialle sono prevalentemente incoerenti o dotate di una modesta coesione indotta da processi pedogenetici o dalla presenza di matrice argillosa. la stabil i tà di questo materiale è pertanto dipendente dall’angolo di attrito interno che localmente può variare in funzione delle condizioni meteoclimatiche (grado di saturazione, processi di gelo-disgelo e/o di umidificazioneessiccazione), dai processi erosivi in atto (riduzione/aumento degli spessori, scalzamento al piede), dall’attività antropica (aratura, zootecnia), ecc. (fig. 6). fig. 3 i “cavalli alati” (museo nazionale etrusco di tarquinia). “the winged horses” (etruscan national museum of tarquinia). fig. 4 sezione geologica schematica del rilievo di tarquinia vecchia. cross section of tarquinia ancient hill. fig. 5 la superficie strutturale formata dal calcare di tarquinia nell’area dell’acropoli di tarquinia vecchia. section of the acropolis of the ancient town showing the structural surface made of the limestone of tarquinia. fig. 6 il progressivo arretramento della scarpata calcarea interessa anche l’equilibrio delle sovrastanti sabbie gialle. the gradual moving back of the limestone escarpment involves the stability of the overlapping yellow sands. il macco riveste un importante ruolo geomorfologico; compreso, infatti, tra le sabbie gialle e le argille azzurre, cioè tra rocce facilmente erodibili, è portato ad “emergere” topograficamente per fenomeni di litoselezione. l’assetto suborizzontale, infine, ne determina 230 2. il calcare di tarquinia presenta caratteristiche sedimentologiche variabili sia verticalmente che orizzontalmente; coesistono e sfumano gli uni negli altri, addensamenti calcarenitici, strati calcareo-marnosi e livelli o lenti di limi sabbiosi, mentre la struttura e l’assetto generale sono in strati e banchi discontinui. il grado di fratturazione è molto elevato (fig 8) e l’infiltrazione delle acque praticamente totale e molto rapida. il comportamento meccanico della roccia varia pertanto anche su modesti volumi, mentre la dissoluzione risulta il processo morfogenetico più efficace (carsificazione). la generale stabilità della superficie strutturale calcarea (pian della civita) si interrompe lungo la scarpata che la delimita e che, ovviamente, risulta esposta al pericolo di crolli. 3. le argille azzurre manifestano un comportamento meccanico abbastanza omogeneo e costante su ampie superfici di affioramento, sono sovraconsolidate, dotate di una moderata coesione e la loro permeabilità è decisamente ridotta anche se, in superficie, lo strato d’alterazione ha un notevole spessore (frequentemente attorno al metro) e viene continuamente areato e rimosso dalle pratiche agricole. come più frequente conseguenza di queste, l’infiltrazione locale può aumentare fino a deteriorare le caratteristiche meccaniche dei materiali mettendone in crisi la stabilità (fig. 7). condizioni idrogeologiche la rapida circolazione delle acque attraverso il calcare di tarquinia viene fermata al contatto con le argille azzurre; entro i calcari si formano così accumuli idrici discontinui, in passato raggiunti anche dai pozzi messi in luce dagli scavi, che alimentano sorgenti perenni (una delle quali captata) o, più frequentemente, emergenze idriche temporanee. queste acque assumono un ruolo importante ai fini della stabilità dei siti archeologici: emergendo al contatto con le argille, ne mantengono elevato il grado di umidità, spesso fino alla completa saturazione. in fig. 7 l’attività antropica contribuisce alla destabilizzazione dei versanti; l’aratura facilita la saturazione del terreno, provocando fenomeni di ruscellamento e di frana. the human activity is a key factor of the slope stability, the ploughing activity leads to the high degree of soil saturation, raising the rill, gully erosion and landslides events. fig. 9 le argille azzurre sono affette da fenomeni franosi retrogressivi che si spingono fino al piede della scarpata calcarea; questa, priva di sostegno, crolla in blocchi anche di considerevole volume. the grey clay are affected by landslide movements moving upslope toward the foot of the limestone escarpment. due to this fact the escarpment falls down with blocks of large dimension. fig. 8 il calcare di tarquinia è profondamente e intensamente fratturato e la rapida e massiccia infiltrazione delle acque ne provoca la continua corrosione. the tarquinia limestone is deeply fractured and the fast infiltration causes the continuous corrosion. queste condizioni è facile che le argille raggiungano lo stato plastico e che si producano fenomeni gravitativi di vario tipo, più frequentemente scivolamenti e colamenti superficiali (fig. 9). c. cattuto et al. 231 il processo è favorito dall’uso agricolo del terreno argilloso; l’aratura a giropoggio viene infatti spinta fino alla base della scarpata calcarea, creando le condizioni per il ristagno delle acque, l’infiltrazione e la massima saturazione del terreno. pericolo per i siti archeologici nelle attuali condizioni il pericolo più grave per l’area degli scavi è quello derivante dal progressivo arretramento della scarpata calcarea (fig. 10) e dal crollo dei manufatti che la sovrastano. anche dove l’arretramento della scarpata rocciosa ha esposto all’erosione le sabbie sovrastanti, si stanno creando fenomeni di instabilità; il più evidente è quello che si è prodotto ai danni della cinta muraria della tarquinia antica, già crollata o direttamente minacciata in più punti (fig. 11) e per lunghe tratte ormai vistosamente inclinata e prossima al ribaltamento (fig. 12). negli anni passati la sommità del colle sul quale si estende l’antica tarquinia era intensamente coltivata e sono ancora visibili, sui blocchi di muratura semiaffioranti dal terreno, le scalfitture prodotte dal vomere. ad evitare la possibile rovina dei manufatti non ancora messi in luce dagli scavi, la stessa area è stata destinata a prato-pascolo. questa pratica ha tuttavia favorito il progressivo deterioramento della copertura erbacea e del suolo; infatti, gli animali al pascolo hanno provocato la diffusione di una specie vegetale resistente e invasiva, la ferula (f. communis) perché tossica e quindi fig. 10 la continuità della pendenza, lungo il versante argilloso che degrada verso l’alveo del f. so di s. savino, è interrotta dalla presenza dei blocchi calcarei, crollati in epoche diverse e poi lentamente trascinati a valle da fenomeni gravitativi che ne permettono il movimento continuo. the clayey slope continuity toward the s. savino stream is interrupted by limestone blocks, fallen down in different periods. these blocks moved slowly down by continuous landslides phenomena. fig. 11 la perdita di sostegno, indotta dall’erosione delle sabbie gialle sulle quali era fondata la cinta muraria di tarquinia vecchia, ne mette a rischio la stabilità in più punti. the lack of the ground support, due to erosion of the yellow sands is the main reason of the slope instability in several places of the ancient tarquinia. fig. 12 lunghe tratte della cinta muraria di tarquinia vecchia, interessate dal movimento del terreno fondale, hanno perduto la verticalità e sono prossime al ribaltamento. long sides of the ancient tarquinia surrounding wall affected by ground foundation movements, lost their vertical structure and are next to toppling. fig. 13 gli scavi e le strutture da questi messe in luce possono rappresentare una via di facile raccolta e veloce scorrimento delle acque superficiali con locali incrementi dell’erosione. the excavations and the resulting highlighted structures could represent a preferential river network that leads to some local higher rate of erosion. condizioni geomorfologiche e stabilità dell’acropoli ... 232 istintivamente immangiabile. la copertura erbacea appetibile è invece sparita completamente e, come conseguenza, anche il suolo è stato progressivamente eroso. per ampie estensioni è venuta alla luce la roccia calcarea fratturata che ha subito l’incremento dei processi corrosivi; lungo le fratture beanti, inoltre, le acque si incanalano in grande quantità andando ad alimentare il circuito sotterraneo e questo fenomeno si realizza anche lungo gli scavi che rappresentano una via preferenziale per il deflusso idrico (fig. 13). la terra, trascinata dalle acque entro le fratture, rende possibile in esse la crescita di specie arboree dotate di un apparato radicale in grado di ampliarle ulteriormente. conclusioni e possibili interventi in mancanza di rilievi topografici mirati (sezioni e piani quotati) e di dati sul comportamento geomeccanico delle argille, non è ovviamente possibile avanzare alcun tipo di progetto, sia pure di massima, utile alla salvaguardia del patrimonio archeologico di tarquinia vecchia. tuttavia, note le caratteristiche geomorfologiche dell’area e la loro evoluzione, è possibile elencare, come in fig 14, gli interventi più idonei per rallentare i processi geomorfologici in atto, mitigando il pericolo di perdita della stabilità dei manufatti d’interesse archeologico: 1. rallentare il ruscellamento disordinato e riducendo sia i l di lavamento che l’ infi ltrazione (opere di raccolta/drenaggio delle acque meteoriche e riduzione della permeabilità superficiale del terreno, favorendo la ricostituzione del suolo e della copertura vegetale); 2. raccogliere e canalizzare le acque emergenti al piede della cornice calcarea per evitare la saturazione e la plasticizzazione delle argille azzurre; 3. edificare opere di sostegno al piede della scarpata calcarea, per contrastare e/o contenere i fenomeni di crollo; nella fascia di terreni prossima al piede dei calcari, le pratiche agricole, e l’aratura in particolare, dovrebbero essere vietate. bibliografia bonadonna f.p. (1967) studi sul pleistocene nel lazio, ii: linee di costa lungo il litorale di tarquinia (lazio settentrionale). geologica romana, vi, 121-135. bonghi j.m. (1986) -testimonianze archeologiche e ricostruzione storica, scavi sistematici nell'abitato. gruppo archeologico romano, i, 11-135, 6 tav. bellotti p., evangelista s., la monica g.b., landini b., milli s. (1993) itinerario n° 11: da roma a tarquinia . vol. 5 (lazio) guide geologiche regionali. soc. geol. it. chiocchini u. (1990) caratteri sedimentologici e stratigrafici delle calcareniti di tarquinia. boll. soc. geol. it., 12, 210-221. fazzini p., gemini r., mantovani m.p. & pellegrini m. (1972) geologia dei monti della tolfa (lazio settentrionale; prov. roma e viterbo). mem. soc. geol. it, 11, pp. 65-144. fregni p., gasperi g. & gelmini r. (1985) il messiniano tra la toscana meridionale e il lazio settentrionale. mem. soc. geol. it, 25, pp. 233-287. ms. ricevuto il 20 febbraio 2006 testo definitivo ricevuto il 31 ottobre 2006 ms. received: february 20, 2006 final text received: october 31, 2006 fig. 14 schema delle possibili opere tese a ridurre il rischio idrogeologico nell’area dell’acropoli. scheme of the hypothetical works in order to reduce the hydrogeologic risk in the acropoli area. c. cattuto et al. imp.sauro-zampieri eevviiddeennzzee mmoorrffoollooggiicchhee ddii tteettttoonniiccaa rreecceennttee ssuull mmaarrggiinnee oorriieennttaallee ddeellllaa mmaaiieellllaa ((aappppeennnniinnoo cceennttrraallee)) uuggoo ssaauurroo11 && ddaarriioo zzaammppiieerrii22 1dipartimento di geografia dell’università di padova, e-mail: ugo.sauro@unipd.it 2dipartimento di geologia, paleontologia e geofisica dell’università di padova, e-mail: dario.zampieri@unipd.it riassunto: sauro u. & zampieri d., evidenze morfologiche di tettonica recente sul margine orientale della maiella (appennino centrale). (it issn 0394 – 3356, 2004). la montagna della maiella è una delle massime elevazioni dell’appennino centrale e la sua grande scarpata orientale è una delle forme tettoniche più spettacolari di tutta la catena. la scarpata è modellata sul fianco di una piega anticlinale, espressione di una sottostante faglia inversa facente parte del sistema neogenico di sovrascorrimenti a vergenza adriatica. l’alto strutturale della maiella deriva tuttavia in parte anche dalla fisiografia dell’avanfossa, in quanto prima della fase di raccorciamento era un horst delimitato da faglie normali antitetiche. in prossimità dello sbocco a valle del grandioso canyon del vallone di s. spirito che incide la maiella, esiste un fenomeno di sbarramento interpretabile come la conseguenza dell’espulsione verticale di un cuneo tettonico in prossimità della base della scarpata. in relazione ai caratteri della stretta forra che ha inciso lateralmente la "diga in roccia", è possibile ipotizzare che l’evento tettonico che ha determinato l’espulsione del cuneo sia riferibile a un momento relativamente recente, anche se difficile da definire con precisione, del pleistocene. pertanto la morfostruttura della maiella non avrebbe cessato la sua attività nel pliocene superiore, come sostenuto dalla letteratura geologica, ma sarebbe stata attiva anche nel quaternario. abstract: sauro u. & zampieri d., geomorphological evidences of recent tectonics along the eastern side of the maiella massif (central apennines). (it issn 0394 – 3356, 2004). the maiella mountain is one of the highest elevations of the central apennines. its huge eastern scarp is also one of the most spectacular tectonic landforms of the belt. the escarpment represents the forelimb of a thrust-related anticline belonging to the neogene adriatic-verging thrust system. nevertheless, the maiella structural high partly results from the shortening of a pre-orogenic horst bounded by antithetic normal faults. in the lower segment of the vallone di s. spirito, one of the main canyons which cuts in the scarp, it is possible to recognize a damming event caused by the extrusion of a tectonic wedge. on the base of the characters of the narrow gorge engraved in the natural dam, the related tectonic episode is referable to a relatively recent moment, even if not easy to be precisely defined, of the pleistocene. thus, it is possible to infer that the maiella morphostructure has not ceased its activity in the upper pliocene, as reported in the geological literature, but has been active also during the quaternary. parole chiave: tettonica recente, erosione fluviale, geositi, appennino centrale. keywords: recent tectonics, fluvial erosion, geosites, central apennine il quaternario italian journal of quaternary sciences 1177(1), 2004, 3-9 11.. pprreemmeessssaa la scarpata che costituisce il margine orientale del massiccio della maiella è una delle più spettacolari forme tettoniche dell’appennino. tale scarpata, che presenta in pianta una forma arcuata, convessa verso est per una lunghezza di oltre 30 km, raccorda le dorsali e gli altopiani sommitali della maiella, che si estendono al di sopra dei 2000 m s.l.m., con la fascia di colline che degrada gradualmente verso la costa adriatica. la transizione morfologica fra la scarpata ed il rilievo collinare ha luogo lungo una linea che corre oscillando fra le quote di 400 ed 800 metri, è molto netta e caratterizzata da un cambiamento sia del tipo di rocce, sia dello stile topografico. infatti, tale linea marca il contatto tra i calcari di piattaforma di scarpata/bacino cretaceo-miocenici e i sedimenti evaporitici e torbiditici silicoclastici miopliocenici (crescenti et al., 1969; vecsei et al., 1998; vezzani & ghisetti, 1998). sulla scarpata, ove affiorano estesamente i calcari di piattaforma, si osserva un incremento delle pendenze da monte verso valle, tale da dare l’impressione di trovarsi di fronte ad una forma tettonica particolarmente giovane, ancora attiva. un problema dello studio di questo tipo di grandi scarpate tettoniche connesse a sistemi di faglie di tipo inverso, e quindi a deformazioni di tipo compressivo, è, tuttavia, quello che, a differenza delle scarpate di faglia normale, non vi si trovano facilmente fenomeni di "surface faulting" tali da permettere di individuare episodi recenti di riattivazione della struttura. e’ quindi indispensabile analizzare queste scarpate in tutte le loro caratteristiche morfologiche per tentare di individuarvi altri tipi di indizi di movimenti tettonici recenti. da questo punto di vista una delle aree più interessanti e complesse di questa grande scarpata è il segmento intermedio, caratterizzato da un complesso sistema di profonde incisioni del tipo canyon fluviocarsico che seguono prevalentemente le direzioni di massima inclinazione degli strati (valli cataclinali di tipo conseguente), ma che si sono impostate in sistemi di fratturazione connessi, almeno in parte, con le 4 u. sauro & d. zampieri condizioni di rilascio tensionale innescate dall’evoluzione morfotettonica della stessa scarpata. in questo lavoro viene presentato un aspetto presente proprio nel contesto di una di queste incisioni, che, secondo noi, è più che un indizio di una riattivazione recente di strutture preesistenti, riconducibile, a grandi linee, ad un momento relativamente recente, anche se di non facile definizione, del pleistocene. 22.. iinnqquuaaddrraammeennttoo ssttrruuttttuurraallee l’anticlinale della maiella rappresenta la struttura affiorante più esterna del sistema di sovrascorrimenti dell’appennino centrale, sviluppatosi a partire dal miocene inferiore (casnedi et al., 1981; ghisetti & vezzani, 1983, 1997). in pianta l’anticlinale presenta una forma arcuata con la concavità rivolta ad ovest e l’asse immergente a nord, dove la struttura è ricoperta in discordanza dai depositi del pliocene superiore. in sezione ha una forma asimmetrica con il fianco orientale (esterno) più ripido. sul lato occidentale (interno) è interessata da un sistema di faglie normali postcollisionali immergenti a ovest, di cui quella del monte morrone è tuttora attiva e viene interpretata come collasso gravitazionale del settore appenninico più ispessito e sollevato (ghisetti & vezzani, 1999a), oppure come migrazione dell’apertura del bacino tirrenico (e.g. lavecchia et al., 1994). faglie normali sinsedimentarie messiniane-plioceniche delimitano i l f ianco interno (faglia di caramanico), ma anche il fianco esterno dell’anticlinale della maiella (scisciani et al., 2000). queste ultime erano in origine immergenti verso l’avanfossa e durante lo sviluppo dell’anticlinale connesso al raccorciamento sono state ruotate ad assumere l’attuale immersione verso ovest ed un’apparente geometria da faglie inverse. l’alto strutturale della maiella sarebbe pertanto in parte derivato dalla fisiografia dell’avanfossa pliocenica inferiore (scisciani et al., 2002). i sedimenti di avanfossa silicoclastici del pliocene inferiore sono coinvolti nella deformazione compressiva e l’età del sovrascorrimento della maiella viene riferita essenzialmente al pliocene medio-superiore (ambrosetti et alii, 1983, casnedi et al., 1981, ghisetti & vezzani, 1983, 1997; scisciani et al., 2000, 2002), non essendo state riconosciute evidenze di un’attività quaternaria. il contatto tra i carbonati del fianco della maiella e i sedimenti terrigeni affioranti ad est di fara s. martino si presenta verticalizzato. per ghisetti & vezzani (1999b) tale assetto, accompagnato da locali movimenti normali e trascorrenti, sarebbe stato prodotto dall’attività tardo-pliocenica della linea volturno-sangro, una discontinuità profonda ad alto angolo con orientazione generale n-s e cinematica trascorrente destra, che corre lungo il fianco est della maiella. secondo cello et al. (1997) e tondi & cello (2003) il campo di stress tardo-quaternario dell’appennino centrale è caratterizzato da un regime trascorrente con asse principale massimo orizzontale orientato nw-se. 33.. eevvoolluuzziioonnee ggeeoommoorrffoollooggiiccaa il demangeot (1965) nella sua celebre memoria sulla geomorfologia degli abruzzi adriatici affronta in modo organico il problema dell’evoluzione geomorfologica del grande versante orientale di questo massiccio carbonatico e dei grandi canyon che lo incidono. sottolinea la freschezza della spettacolare scarpata tettonica, che sembra contrastare con l’età relativamente antica della faglia che la delimita a valle. nell’ambito del grande versante, egli indica diversi ordini di ripiani, che interpreta come spianate in roccia, relitti di antiche piattaforme di spianamento erosivo create in prossimità del livello di base (antico livello del mare) ad opera di fiumi costieri o dello stesso mare. sostiene di riconoscere nell’ambito dei profili longitudinali dei canyon un’alternanza di tratti relativamente poco inclinati rispetto alla pendenza media, correlabili sia tra di loro, sia con i ripiani dei versanti e distinguibili in un numero di ordini variabile tra due e quattro. per questo motivo interpreta i grandi canyon come delle forme policicliche, risultanti da un’alternanza di momenti di rapido sollevamento con momenti di stasi del sollevamento tettonico. conseguenza dell’evoluzione ciclica sarebbe anche il progressivo restringimento delle incisioni a partire dalla dorsale sommitale verso la periferia. il più alto degli ordini di ripiani sarebbe riferibile al tardo oligocene, mentre il più basso alla fine del pliocene (villafranchiano). in altre parole, la maiella si sarebbe andata sollevando e strutturando nell’arco di oltre 30 milioni di anni e l’ultima fase di attività tettonica importante sarebbe riferibile alla fine del pliocene o all’inizio del quaternario. se da un lato appare abbastanza ovvio che il sollevamento della maiella e la genesi della grande scarpata orientale siano il risultato di più episodi e fasi tettoniche ed è probabile che almeno alcuni dei ripiani di versante individuati dal demangeot siano relitti di superfici spianate in prossimità di antichi livelli di base, tuttavia, un’analisi dettagliata del quadro geomorfologico non fornisce elementi convincenti a favore delle conclusioni cui è giunto questo studioso. infatti, nell’ambito della grande scarpata alcuni ripiani in roccia si riconoscono, con una certa difficoltà, soltanto nel settore settentrionale, e l’analisi dei profili longitudinali dei canyon non consente di rilevare degli ordini di segmenti a bassa pendenza correlabili tra di loro (fig. 1). pertanto, il quadro geomorfologico d’insieme farebbe propendere per un sollevamento relativamente continuo, almeno in una dimensione geologica, piuttosto che per uno a scatti. le variazioni di pendenza dei profili dei canyon sembrano maggiormente legate a fattori locali di diverso tipo, piuttosto che ad un’evoluzione di tipo policiclico. da un’analisi geomorfologica, i canyon della maiella risultano essere forme complesse, risultanti da una cooperazione di processi di tipo diverso che si sono esplicati nel corso del sollevamento della montagna. e’ quindi corretto definirli canyon poligenetici piuttosto che canyon policiclici. ma si tratta certamente anche di forme relativamente giovani che non sembrano avere alle spalle una storia lunga come quella presupposta nel modello del demangeot. 44.. lloo ""ssbbaarrrraammeennttoo"" ddii vvaallllee ddeell vvaalllloonnee ddii ssaannttoo ssppiirriittoo chi si inoltri nello sbocco del vallone di s. spirito nel grande versante orientale della maiella (versante 5evidenze di movimenti tettonici ... adriatico) poco a monte di fara di san martino ha l’impressione, dopo aver percorso un centinaio di metri, di trovarsi chiuso il cammino da una parete in roccia (figg. 2, 3). solo l’osservazione attenta permette di scoprire sul lato sinistro della parete la stretta apertura di una forra che per 50 metri mantiene la larghezza di circa 2-3 m e che poi si apre, all’improvviso, in una forra molto più ampia (20-50 m) (fig. 4). questo stretto accesso alla forra interna ha determinato nel medioevo la scelta di costruire il monastero benedettino di s. martino, subito a monte dello sbarramento. era infatti facile impedire l’accesso ad eventuali predoni. il toponimo "vallone di s. spirito" è legato alla storia del monastero, poi abbandonato in seguito ad uno o più eventi di piena torrentizia, che ne hanno provocato un parziale seppellimento. l’improvviso restringimento della valle riguarda il tratto terminale del sistema idrografico val cannella vallone di macchia lunga vallone di s. spirito che costituisce una delle più spettacolari valli incassate nel grande versante orientale della maiella. su questo versante si scende dai 2793 m del m. amaro ai 400 m di fara di san martino su una distanza planimetrica di 10 km con una pendenza media di circa il 24%. tuttavia, nella fascia inferiore del versante le pendenze sono considerevolmente maggiori: mediamente quasi il 40% tra il m. acquaviva (2737) e fara di s. martino, circa il 45% tra il m. pizzone (2214) e fara di san martino, circa il 66% nella fascia di scarpata compresa fra 800 e 1800 m s.l.m., 4 km a sud di fara. il sistema idrografico inizia con un ampio circo glaciale per continuare con un vallone dapprima ad u, poi progressivamente a v e quindi con un canyon fluviocarsico sul cui fondo si individua una forra dalle pareti subverticali larga parecchie decine di metri ed a tratti ingombra di accumuli di frana e di grandi coni secchi di debris flow che determinano fenomeni di sbarramento ed alternanza di segmenti poco ripidi e di gradini. in sinistra idrografica il vallone di macchia lunga riceve la confluenza della valle delle mandrelle, la quale nasce da un circo a sud del m. acquaviva e risulta sospesa rispetto alla valle principale per la presenza di una gradinata di spettacolari salti. in destra idrografica, a se di cima dell’altare c’è un grande circo sospeso sul vallone di macchia lunga. nel segmento più a monte, la linea di fondovalle presenta la direzione wnw-ese, per poi tendere, nel tratto intermedio, ad una direzione w-e e quindi, nel segmento più a valle, ad un orientamento sw-ne, obliquo rispetto alla grande scarpata tettonica che qui caratterizza il bordo orientale della maiella. la forma del bacino idrografico è grossomodo quella dell’impronta di un fagiolo, più stretta alla sua estremità meridionale e della superficie complessiva di circa 26 km2. nella parte più a valle della forra, il profilo è spesso asimmetrico, in fig. 2 lo sbarramento roccioso del vallone di santo spirito visto da valle. una stretta forra sul lato sinistro permette di superare questa barriera. the natural rocky barrier of the canyon of santo spirito as seen from downvalley. a narrow gorge on the left side allows to bypass this obstacle. fig. 1 schizzo morfotettonico della maiella e profili longitudinali dei principali valloni che ne incidono il versante orientale. morphotectonic sketch of maiella mountain group and longitudinal profiles of the main canyons of its eastern slope. 6 quanto sul versante sinistro si alternano superfici di stratificazione, data la giacitura a franapoggio degli strati, con pareti; il versante destro è invece una grande parete interrotta soltanto da alcuni ripidi canaloni. in questa parte, l’andamento della forra risulta condizionato dalla giacitura degli strati, che diventano sempre più inclinati man mano che ci si avvicina alla scarpata periferica. l’incisione tende quindi ad assumere il carattere di valle omoclinale. la "diga" in roccia che costituisce lo sbarramento ha la forma di un cuneo più largo sul lato settentrionale e più stretto sul lato meridionale (rispettivamente circa 70 e 45 m). la sua superficie superiore è inclinata verso sud e pertanto l’altezza dello sbarramento decresce da nord verso sud (fra circa 40 e 20 m). la parete che guarda verso monte è obliqua rispetto all’asse della forra principale; la parete a valle è invece quasi ortogonale. lo spigolo superiore della parete a valle è arrotondato e pertanto il profilo è convesso, con un’accentuazione dove la parete è più bassa. qui la roccia appare molto più fessurata e fratturata che nella fascia inferiore. in basso la parete appare arretrata di pochi metri (1-5 m) rispetto al piano tettonico sezionato dal fianco destro della valle. la parete a monte mostra un arretramento più modesto rispetto al piano tettonico, dell’ordine del metro; risulta inoltre degradata da incavi e fessure da carsismo di contatto che raggiungono la profondità di circa 1 metro. la stretta forra che costituisce il bypass è una tipica forma di erosione torrentizia. presenta un asse inclinato di circa 70% verso sud, cioè verso la base del versante destro (meridionale). le pareti mostrano incavi e marmitte di parete, espressioni dell’elevata energia del corso d’acqua che ha percorso questa incisione trasportandovi ciottoli e massi. 55.. aassppeettttii ee ccoonnsseegguueennzzee ddii uunn eevveennttoo tteettttoonniiccoo rreecceennttee la "diga" in roccia che sbarra il vallone di s. spirito non può essere spiegata sulla base di semplici fenomeni di modellamento del rilievo ad opera di processi dell’erosione. certamente non si tratta di una contropendenza originata dall’erosione glaciale. a queste quote non esistono indizi di alcun tipo di modellamento glaciale. la congruenza tra questa forma ed i piani di faglia che la delimitano e che proseguono nelle pareti laterali (fig. 5) permette di ipotizzare che si tratti di una forma tettonica risultante dall’espulsione verticale di un cuneo tettonico in concomitanza con una riattivazione di strutture connesse con il sistema tettonico della grande scarpata orientale della maiella. e’ verosimile che un campo di stress attuale con asse principale massimo orizzontale orientato nw-se (cello et al., 1997, tondi & cello, fig. 3 lo sbarramento roccioso del vallone di santo spirito visto da monte. si intravede la stretta forra di incisione torrentizia sul lato destro. the natural rocky barrier of the canyon of santo spirito as seen from up-valley. the narrow gorge cut by a creek is on the right side. fig. 4 pianta della forra con i principali elementi strutturali. plan view of the gorge with the main structural elements u. sauro & d. zampieri 7 2003) possa produrre una transpressione sinistra su una struttura siffatta. non è tuttavia ancora del tutto chiaro il meccanismo cinematico in grado di produrre un movimento essenzialmente verticale di un cuneo che in sezione appare divergente verso i l basso. alternativamente, nel caso il cuneo descritto fosse compatibile con il modello di deformazione del margine orientale della maiella descritto da ghisetti & vezzani (1999b), la linea volturno-sangro avrebbe continuato la sua attività anche nel pleistocene. sulla base dei diversi elementi raccolti è possibile abbozzare il seguente modello di evoluzione morfotettonica (fig. 6): a) in un momento geologico recente, eventi tettonici ravvicinati di riattivazione delle strutture connesse con la grande scarpata causano l’espulsione di un cuneo per un rigetto morfologico verticale superiore ai 20 metri; la parte superiore di questo cuneo presenta già un sistema di fessure precedentemente allargate dal fenomeno carsico, quando la roccia si trovava coperta dai riempimenti alluvionali del fondovalle; b) in seguito allo sbarramento della valle si forma una conca chiusa che potrebbe aver ospitato un lago effimero per le perdite di tipo carsico; c) il torrente riempie di depositi ciottolosi la depressione che si è creata a monte sino a colmarla; l’acqua presente nell’acquifero ospitato in questi depositi favorisce la carsificazione della parete sepolta; d) il torrente inizia ad incidere la soglia della diga in roccia; l’azione di incisione diventa efficace dopo che la depressione è stata colmata di depositi ciottolosi. nei momenti di piena si formano una corrente ed una cascata di acqua che trascinano ciottoli e che quindi esercitano una notevole capacità abrasiva; e) nei momenti di piena, la cascata determina uno smussamento dello spigolo a valle della "diga" ed un arretramento della parete, a cui si accompagna un’azione di incisione sul lato più basso della "diga", cioè sul suo margine meridionale, con conseguente formazione della stretta forra nella cui genesi gioca un ruolo importante l’azione di evorsione esercitata dai ciottoli trasportati. e’ possibile formulare anche altri modelli che, per esempio, prevedano un ripetersi degli episodi di deposizione a monte della "diga", con riempimento e ostruzione della forra in formazione, o, addirittura, seppellimento dell’intera "diga" in relazione all’alternarsi di fasi di maggiore o minore attività idrica del torrente e di produzione fig. 5 schizzo delle strutture tettoniche riconoscibili sulle pareti della forra principale appena a valle dello sbarramento. sketch of the main tectonic structures on the sides of the main canyon just downstream of the natural dam. fig. 6 schizzo della possibile evoluzione del fenomeno di sbarramento e di incisione della stretta forra. 1: situazione di pre-sbarramento, 2: espulsione tettonica e sbarramento, 3: incisione della forra. e’ necessario considerare che l’espulsione del cuneo ha comportato l’attivazione di più faglie sui due lati dello stesso con movimenti sia obliqui, sia verticali. sketch of the possible evolution of of the tectonic damming and of the down-cutting of the gorge. 1: pre-damming situation, 2: wedge expulsion and valley damming, 3: gorge cutting. it must be considered that the wedge expulsion interested different faults on both sides of the morphostructure with both oblique and vertical movements. evidenze di movimenti tettonici ... 8 di detrito nel bacino a monte. dal punto di vista dell’età di questa forma, se si tiene conto della larghezza e profondità della forra e dell’arretramento subito per erosione meccanica e per degradazione fisica e chimica dalle pareti della diga, si può ragionevolmente supporre si tratti di una forma che ha attraversato almeno una fase di intensa attività torrentizia, molto maggiore rispetto a quella attuale. nelle alpi, forre simili in ambienti glacializzati sono comunemente ritenute forme polifasiche, che si sono evolute nel corso di più oscillazioni glaciali (castiglioni, 1958). forme di queste dimensioni in val di non sono state però attribuite all’ultima glaciazione, sulla base di considerazioni sia morfologiche che di correlazione con i depositi glaciali (sauro, 1976). tuttavia, negli ambienti appenninici, date le condizioni ambientali e paleoambientali diverse da quelle delle alpi, tra cui il notevole sviluppo di un’idrologia di tipo carsico, è particolarmente difficile attribuire un’età precisa a queste forme. l’attività torrentizia che le ha create potrebbe essere stata particolarmente intensa quando nel bacino a monte esisteva un ghiacciaio, durante l’ultima fase di espansione glaciale che nell’appennino centrale ha avuto il suo massimo intorno ai 22 mila anni fa (giraudi & frezzotti, 1997). e’ quindi molto probabile che l’espulsione del cuneo sia avvenuta prima di questo momento del pleistocene superiore. 66.. ccoonnssiiddeerraazziioonnii ccoonncclluussiivvee la "diga in roccia" che ha determinato la formazione della forra, considerata nel suo contesto morfostrutturale, rappresenta un’evidenza di un movimento tettonico recente nell’ambito delle grande scarpata orientale della maiella. un’attenta analisi di questo sbarramento naturale permette di escludere sia che esso possa essere la conseguenza di un fenomeno di sovraescavazione a monte, sia che possa trattarsi della conseguenza di un movimento gravitativo nell’ambito della grande scarpata. nella fascia inferiore della stessa scarpata è possibile riconoscere altre strutture cuneiformi espulse in seguito a fenomeni tettonici, spesso associate a strutture di trascinamento degli strati (drag folds) (fig. 7). queste forme meriterebbero un’approfondita analisi strutturale. questo cuneo espulso, che ha rappresentato una sorta di "diga naturale", non costituisce un semplice dettaglio nell’ambito della grandiosa scarpata orientale della maiella, ma l’espressione del fatto che la scarpata è una forma tettonica ancora "viva", che mostra una notevole freschezza. dato il contesto erosivo è difficile trovare dei marker cronologici, in particolare di tipo sedimentario, che possano favorire una ricostruzione più precisa di momenti chiave di quest’evoluzione. non dimentichiamo tuttavia che all’interno dei canyon esistono numerose grotte carsiche che non sono mai state studiate, ed, in parte, neppure esplorate e che potrebbero aver registrato nei loro sedimenti eventi significativi della storia di questo versante della maiella. in ogni caso, la stretta forra, considerata nel suo contesto tettonico e geomorfologico, rappresenta una particolarità "geologica" meritevole sia di ulteriori studi, sia di interventi di tutela e valorizzazione nell’ottica di una didattica di tipo naturalistico-culturale. e’ certamente meritevole di essere censita come un importante "geosito", per il suo interesse rilevante per la conoscenza della storia della seconda montagna dell’appennino. rriinnggrraazziiaammeennttii esprimiamo un particolare ringraziamento a ezio burri e andrea borsato che ci hanno accompagnato sul terreno e hanno contribuito alla discussione sull’evoluzione della forma. questo lavoro è stato in parte finanziato dal miur cofin 2002 (prot. 2002043912_002). fig. 7 cuneo tettonico espulso nell’ambito della fascia inferiore della grande scarpata tettonica della maiella, in prossimità di fara di san martino. sul lato a valle si riconosce una piega di trascinamento. questa struttura presenta forti analogie con quella descritta, che si trova poche centinaia di metri più a ovest. a partially extruded wedge in the lower belt of the tectonic scarp of maiella near fara di san martino. a drag fold affects the downvalley side. this structure shows strong analogies with that described, which is located few hundred metres westwards. u. sauro & d. zampieri bbiibblliiooggrraaffiiaa ambrosetti p., bosi c., carraro f., ciaranfi n., panizza m., papani g., vezzani l. & zanferrari a. (1983) – neotectonic map of italy. consiglio nazionale delle ricerche, roma. casnedi r., crescenti u., d’amato c., mostardini f. & rossi u. (1981) il plio-pleistocene del sottosuolo molisano. geol. romana, 2200, 1-42. castiglioni g.b. (1958) – studi geologici e morfologici del territorio di baceno e premia (val d’ossola, alpi lepontine). mem. ist. geol. mineral. università di padova, 2200, 1-82. cello g., mazzoli s., tondi e. & turco e. (1997) – active tectonics in the central apennines and possibile implications for seismic hazard analysis in peninsular italy. tectonophysics, 227722, 43-68. crescenti u., crostella a., donzelli g. & raffi g. (1969) stratigrafia della serie calcarea dal lias al miocene nella regione marchigiano-abruzzese (parte ii – litostratigrafia, biostratigrafia, paleogeografia). mem. soc. geol. it., 88, 343-420. demangeot j. (1965) la montagne de la maiella. mém. et doc., in géomorphologie des abruzzes adriatiques. ed. du centre rec. doc. cart. geogr., cnrs, n.h.s., 403 pp, paris. ghisetti f. & vezzani l. (1983) deformazioni pellicolari mioceniche e plioceniche nei domini strutturali esterni dell’appennino centro-meridionale (maiella ed arco morrone gran sasso). mem. soc. geol. it., 2266, 563-577. ghisetti f. & vezzani l. (1997) interfering paths of deformation and development of arcs in the foldand-thrust belt of the central apennines (italy). tectonics, 1166, 523-536. ghisetti f. & vezzani, l. (1999a) depth and modes of pliocene-pleistocene crustal extension of the apennines (italy). terra nova, 1111, 67-72. ghisetti f. & vezzani l. (1999b) – geometrie deformative ed evoluzione cinematica dell’appennino centrale. studi geologici camerti, 1144, 127-154. giraudi c. & frezzotti m. (1997) late pleistocene glacial events in the central apennines, italy. quaternary-research, 4488 (3), 280-290. lavecchia g., brozzetti f., barchi m., menichetti m. & keller j.v.a. (1994) seismotectonic zoning in east-central italy deduced from an analysis of the neogene to present deformations and related stress fields. geol. soc. of am. bull., 110066, 11071120. sauro u. (1976) cenni morfologici sulla val di non. in: aspetti geografici del trentinoalto adige occidentale. ist. geogr. padova, xxii, 1974, 113-125. scisciani v., calamita f., bigi s., de girolamo c. & paltrinieri w. (2000) the influence of syn-orogenic normal faults on pliocene thrust system development: the maiella structure (central apennines, italy). mem. soc. geol. it., 5555, 193-204. scisciani v., tavarnelli e. & calamita f. (2002) the interaction of extensional and contractional deformations in the outer zones of the central apennines, italy. j. struct. geol., 2244, 1647-1658. tondi e. & cello g. (2003) – spatiotemporal evolution of the central apennines fault system (italy). j. geodynamics, 3366, 113-128. vecsei a., sanders d., bernoulli d., eberli g. & pignatti j. (1998) cretaceous to miocene sequence stratigraphy and evolution of the maiella carbonate platform margin, italy. sepm sp. publ., 6600, 53-74. vezzani l. & ghisetti f. (1998) carta geologica dell’abruzzo. scala 1:100.000. selca, firenze. 9 ms. ricevuto il 22 luglio 2003 testo definitivo ricevuto il 4 novembre 2003 ms. received: july 22, 2003 final text received: november 4, 2003 evidenze di movimenti tettonici ... sess 2_16022011_tpr3.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 the primary role of the paganica-san demetrio fault in the seismic landscape of the middle aterno valley basin anna maria blumetti, luca guerrieri & eutizio vittori ispra – servizio geologico d’italia, roma corresponding author: a. blumetti <annamaria.blumetti@isprambiente.it> abstract: blumetti a. m., guerrieri l. & vittori e., the primary role of the paganica-san demetrio fault in the seismic landscape of the middle aterno valley basin. (it issn 0394-3356, 2011) the paganica-san demetrio fault, which caused the april 9, 2009 earthquake, has played a key role in the evolution of the middle aterno valley basin since the middle pleistocene. its minimum offset, marked by the elevation of the remnant paleosurface of the anzano plateau, is in excess of 700 m. in our interpretation, the assergi and campo imperatore faults with their assumed listric geometry would merge into the paganica-san demetrio master fault. riassunto: blumetti a. m., guerrieri l. & vittori e., il ruolo primario della faglia paganica-san demetrio nel paesaggio sismico del bacino della media valle dell’aterno. (it issn 0394-3356, 2011) la faglia paganica-san demetrio, cui è legato il terremoto del 9 aprile 2009, ha giocato un ruolo primario nell’evoluzione del bacino della media valle dell’aterno almeno a partire dal pleistocene medio. il suo rigetto minimo, calcolato sulla base della differenza in quota tra la media valle dell’aterno e lembi dislocati di una paleosuperficie, supera i 700 m. nella nostra interpretazione essa è da considerare la master fault del blocco tettonico del gran sasso alla quale le faglie di assergi e campo imperatore, ad andamento listrico, si raccordano in profondità. key words: block faulting, morphotectonics, central apennines. parole chiave: tettonica a blocchi, morfotettonica, appennino centrale. 1. introduction on april 6 2009 a mw 6.3 earthquake rocked the middle aterno valley basin (abruzzo, central italy) causing about 300 casualties and strong damage to the l’aquila city and its surroundings. the paganica-san demetrio fault, which bounds the middle aterno valley basin to the n-e, has been considered the causative fault of this event. this paper aims at better pointing out the longterm role of this fault in the quaternary evolution of the middle aterno valley basin. 2. regional geological framework the characteristic landscape of central apennines, marked by fault-bounded basins and ranges, has been interpreted as the long-term effect of blockfaulting and fast uplift starting approximately 0.8 myr ago (blumetti & guerrieri, 2007 and references therein). ne-sw extension across the apennines is still active, as suggested by geodetic data that indicate rates ranging from 3 to 5 mm/yr (respectively, faure walker et al., 2010; d’agostino et al., 2008). moreover, the size of these tectonic basins and of the associated fault-generated mountain fronts has been considered a peculiar feature, indicative of the local seismic potential (concept of seismic landscape, e.g. michetti et al., 2005). the middle aterno valley basin (l’aquila) is a sector of central apennines (fig. 1) located between the gran sasso and the monti d’ocre morphotectonic units. in this region, surface geology and geophysical data reveal a composite structural setting given by several over-thrust tectonic units belonging to the transitional domain between the lazioabruzzi carbonate shelf platform and the umbriamarche pelagic basin, dissected by a network of quaternary normal faults, in places located close to the uppermost traces of older thrust planes (apat, 2006). stratigraphic and morphological evidence suggest ongoing activity along several of these faults (fig. 1; bagnaia et al., 1992; blumetti, 1995; galli et al., 2008) as confirmed by historical seismicity (three imcs ≥ ix events hit this same area in 1461, 1703 and 1762 (gruppo di lavoro cpti, 2004). 3. paganica-san demetrio fault and quaternary evolution of the middle aterno valley basin the quaternary evolution of the l’aquila region can be synthesized in two phases. the lower pleistocene landscape was characterized by several lacustrine basins controlled by normal faults. nevertheless, the low uplift rates allowed to form a low energy relief landscape with wide pediments mainly formed by areal erosional processes (demangeot, 1965). after the dramatic increase of uplift rates and faults 84 86 85 thrusts at depth (d’agostino et al., 1997). the region at the footwall of the paganica-san demetrio fault (i.e. the gran sasso chain together with anzano and aragno plateau zone) in our view is a single first order morphotectonic unit. this block has been displaced in several tectonic units of lower rank by very long and important faults, like the assergi and campo imperatore faults (slip rates 0.67-1 mm/yr; giraudi & frezzotti, 1995; galli et al., 2002) as well as by a set of secondary very shallow listric faults (e.g., the ruzza mt. and s. stefano di sessanio faults) that have an arc shape in plant view and are mostly gravity driven (bagnaia et al., 1992). based on their likely listric geometry, the assergi and campo imperatore faults should join at depth the paganica san demetrio high angle normal fault. gravity-driven movements may have contributed to the total slip activity since the end of the lower pleistocene (demangeot, 1965; ambrosetti et al., 1982) these pediments have been displaced and are now preserved as remnants at different elevations in the present landscape, that is deeply dissected by linear erosion. we interpret that during this period (about 800 kyr) the middle aterno valley unit (with an average surface at about 700 m a.s.l.) has been downthrown by the paganica san demetrio normal fault with respect to the 1500 m a.s.l. high anzano and aragno plateau summit paleosurface area. at the same time, this zone was downthrown with respect to the gran sasso chain (highest elevation in the apennines, close to 3000 m a.s.l.) by the wnwese trending south-dipping assergi and campo imperatore normal faults, which have a listric geometry, possibly representing reactivations of old fig. 1, 3d view (based on a 20 m dtm) of the l'aquila region with reported the net of capable faults, defining a seismic landscape. the major faults (1) are signed by prominent fault escarpments and bound first order tectonic blocks. minor faults within the major blocks, sometimes with an evident listric geometry, can be ranked in two categories: (2) high slip rate faults at the base of large fault escarpments generally representing reactivations of old thrusts; these bound second order blocks; (3) faults that produce lower fault scarps and bound third order blocks. remnants of low relief landscape (4) can be used as throw markers. immagine 3d (basata su un dtm a 20 m) della regione aquilana, con riportate le faglie capaci che definiscono il paesaggio sismico. le faglie principali (1) sono caratterizzate da versanti di faglia che bordano blocchi tettonici di primo ordine. faglie minori all’interno dei blocchi principali, talvolta con evidente andamento listrico, possono essere gerarchizzate in due categorie: (2) faglie alla base di grandi versanti di faglia, con elevato slip rate e che generalmente invertono piani di sovrascorrimento; queste definiscono blocchi di secondo ordine; (3) faglie che producono scarpate di faglia minori e bordano blocchi di terzo ordine. lembi di un paesaggio a bassa energia di rilievo (4) possono essere utilizzati come riferimento nel calcolo dei rigetti post pleistocene medio  the primary role of the paganica-san demetrio– ... 86 ms. received: testo ricevuto il geol., it. 126 (2), 307-322. blumetti a.m. (1995) neotectonic investigations and evidence of paleoseismicity in the epicentral area of the january-february 1703 central italy earthquakes. in perspectives in paleoseismology l. serva (editor), bull. of the american association of engineering geologists, special volume 6, 83-100. d’agostino n., speranza f. & r. funiciello (1997) stili e geometrie della tettonica estensionale quaternaria nell’appennino centrale: l’area del gran sasso d’italia, il quaternario, 10 (2), 389-394. d’agostino n., avallone a., cheloni d., d’anastasio e., mantenuto s., & selvaggi g. (2008) active tectonics of the adriatic region from gps and earthquake slip vectors. journal of geophysical research, 113, b12413. demangeot j. (1965) géomorphologie des abruzzes adriatiques. memoirs et documents, cnrs, paris. dramis f. & blumetti a.m. (2005) some considerations concerning seismic geomorphology and paleoseismology. tectonophysics, 408, 177-191. faure walker j. p., roberts g. p., sammonds p., & cowie, p. a. (2010) comparison of earthquakes strains over 102 and 104 year timescales: insights into variability in the seismic cycle in the central apennines, italy, journal of geophysical research (solid earth), doi:10.1029/2009jb006462. galli p., galadini f., moro m., & giraudi c. (2002) new paleoseismological data from the gran sasso d’italia area (central apennines). geophys. res. lett., 29 (7), 1134, doi:10.1029/2001gl013292. galli p., galadini f., & pantosti d. (2008) -twenty years of paleoseismology in italy. earth science review, 88, 89-117. giraudi c. & frezzotti m. (1995). paleoseismicity in the gran sasso massif (abruzzo, central italy), quat. int., 25, 81-93. gruppo di lavoro cpti, 2004. catalogo parametrico dei terremoti italiani, versione 2004 (cpti04). ingv, bologna. / http://emidius.mi.ingv.it messina p., galli p., giaccio b. & peronace e. (2009) quaternary tectonic evolution of the area affected by the paganica fault (2009 l'aquila earthquake). in: atti 28° convegno nazionale gngts, trieste, 47-50. michetti a.m., audemard f. & marco s. (2005) future trends in paleoseismology: integrated study of the seismic landscape as a vital tool in seismic hazard analyses. in: paleoseismology, integrated study of the quaternary geological record for earthquake deformation and faulting, a.m. michetti, f. audemard & marco s. (eds), special issue, tectonophysics, 408 (1 -4) , 3-21. nijman w. (1971) neotectonics of the velino-sirente area, abruzzi, central italy. koninkl. nederl. akademie van wetenshappen, amsterdam, proceedings, 74 (2), 156-184. observed on the higher listric faults (nijman, 1971; blumetti, 1995; dramis & blumetti, 2005) and this would account for their very high slip rate. in this model, the paganica san demetrio would be the master fault of the whole gran sasso middle aterno valley fault system, despite the lack of a clear fault-generated mountain front related to it. actually, the middle aterno valley border lacks the prominent fault-generated mountain front typical of other basins. instead, at the footwall of the bounding fault, the extension is accommodated along several nw-se trending normal faults which cause an horsts and graben landscape. the elevation of about 1500 m of the anzano plateau is gradually reached through a set of narrow ridges and small elongated basins. moreover, in the area where surface faulting occurred in 2009, i.e. along the paganica fault segment, the presence in the footwall of a paleo-drainage since at least the end of lower pleistocene (paleo-raiale, sensu messina et al., 2009) contributed to smooth the fault escarpment. relict forms of this paleo-landscape and different orders of fluvial deposits terraced by the progressive activity of the paganica fault are still preserved in its footwall. volcanic deposits dated between 560 and 360 kyr b.p., being displaced of about 150 m, constrain the paganica fault long term slip rate to ca. 0.4 mm/yr (messina et al., 2009). the primary role played by the paganica-san demetrio fault has important consequences in terms of seismic hazard, being now acknowledged as the main seismic source of the basin. if, as suggested here, the campo imperatore and assergi faults move as its splays, their seismic potential would be directly controlled by that of the main fault. references ambrosetti p., carraro f., deiana g. & dramis, f. (1982) il sollevamento dell’italia centrale tra il pleistocene inferiore e il pleistocene medio. contributi conclusivi per la realizzazione della carta neotettonica d’italia. cnr-pfg, 513, 219–223. apat (2006). foglio 359 l’aquila. carta geologica d’italia alla scala 1:50000. s.el.ca., firenze. bagnaia r., d’epifanio a. & sylos labini s. (1992) aquilan and subaequan basins: an example of quaternary evolution in central apennines, italy. quaternaria nova, 2, 187-209. blumetti a.m. & guerrieri l. (2007) fault-generated mountain fronts and the identification of fault segments: implications for seismic hazard assessment, boll. soc. january 15, 2011 15 gennaio 2011 a. m. blumetti, l. guerrieri & e. vittori sess 2_16022011_tpr3.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 new morphological, stratigraphic, structural and pedological data on the t. traversola deformation zone recent evolution (asti, piedmont) alfredo doglione1, m. gabriella forno2 & marco gattiglio2 1 freelance professional, via cernaia 28, torino 2dipartimento di scienze della terra, università di torino, via valperga caluso 35, torino corresponding author: m. g. forno <gabriella.forno@unito.it> abstract: doglione a., forno m. g. & gattiglio m., new morphological, stratigraphic, structural and pedological data on the t. traversola deformation zone recent evolution (asti, piedmont). (it issn 0394-3356, 2011). the new morphological, stratigraphic, structural and pedological data on the type-area villafranchian succession suggest the southern extension of the t. traversola deformation zone. this structure corresponds to the evident scarp that divides the poirino plateau by the asti reliefs. in the previous works the northern sector of the structure was, exclusively, recognized. riassunto: doglione a., forno m. g. & gattiglio m., nuovi dati morfologici, stratigrafici, strutturali e pedologici sull’evoluzione recente della zona di deformazione del t. traversola. (it issn 0394-3356, 2011) i nuovi dati morfologici, stratigrafici, strutturali e pedologici riguardanti la successione villafranchiana dell’area-tipo suggeriscono la prosecuzione verso sud della zona di deformazione del t. traversola, di cui in lavori precedenti era già segnalato il tratto settentrionale, corrispondente alla evidente scarpata che separa i rilievi dell’astigiano dall’altopiano di poirino. key words: asti reliefs, deformation, villafranchian succession. parole chiave: rilievi dell’astigiano, deformazione, successione villafranchiana the morphological evidence of the tertiary piedmont basin (btp) consists of hilly reliefs: the turin hill and the monferrato reliefs on the northern side; the poirino plateau, the asti reliefs and the alessandria plateau in the centre; and the langhe reliefs on the southern side. the new research focuses on the central part of the btp, which corresponds geologically to the asti syncline (4 in fig. 1). this structure is made up of the littoral marine asti sands (middle pliocene) and the deltaic and fluvial type-area villafranchian succession (middle pliocene-lower pleistocene), together with a thin cover of subsequent fluvial sediments (middle-late pleistocene), connected to the ancient courses of the po and tanaro rivers (5 and 6 in fig. 1). the pronounced n-s scarp breaking up the central part is one of the most significant geological features of the hilly area: it is 30 km long and 100 metres high on average, running along a generally straight line, with local-level segmentation. the scarp divides a west sector plain (poirino plateau) from a hilly east sector (asti reliefs). the scarp, described by numerous authors, has been attributed to different geneses. in the early geological literature (castiglioni, 1934; sacco, 1917) the scarp was linked exclusively to the erosional phenomenon produced by the present course of the tanaro river (8 in fig. 1) and its tributary hydrographical network, following the deviation of the ancient course (6 in fig. 1) during the late pleistocene. in subsequent studies (forno, 1982; alessio et al., 1982; carraro & valpreda, 1991) the different elevation of the middle-late pleistocene fluvial sediments on the two sides of the scarp led to the presumption of the presence of a vertical d i sp lacement s t ruc tu ra l d iscon t inu i t y corresponding to the scarp, explained as a “flexure”. in the recent literature (carraro ed., 1996; boano et al., 1997; boano & forno, 1999) a detailed geological survey of the villafranchian succession type-area gave rise to the interpretation that the northern segment of the scarp was connected to a structural discontinuity named “t. traversola deformation zone” (1 in fig. 1). in this segment the structure has traces of a dextral strike-slipe displacement and has different stratigraphic successions on the two sides. in the other segment of the scarp the structure was not recognized due to the scarcity of outcrops and the absence of structural evidence and stratigraphic elements. indeed, recognition of strike-slipe displacement structures in a sub-horizontal succession is obviously very difficult and this difficulty essentially resulted in a delay in the identification of the t. traversola deformation zone, despite its strong morphological evidence (fig. 2). only through a detailed survey of the stratigraphic succession outcropping on both sides of the scarp and an interdisciplinary approach, comprising the collection of morphological, structural and pedological data, now being presented, has it been possible to identify a structure along the entire scarp. specifically, this research has enabled the 101 103 102 the depressions aligned along the scarp and the numerous landscapes, are described. meso-structural evidence suggests the horizontal displacement of the asti syncline axis (4 in fig. 1) and detailed observations have permitted the identification of some metric fault surfaces, along the main structure. the survey of soils involving the sediments on both sides of the scarp, on the other hand, have enabled the correlation of the corresponding geological bodies and identification of the relative movements. some evidence, already reported in the literature, supports the btp uplift: the progressive transition from a marine to a continental environment, the deviation of the ancient rivers (5 and 6 in fig. 1), recognition of the structure’s southern extension and the description of both its chronological reference and displacement type. the new stratigraphic data collected show no vertical displacement and, instead, suggest the horizontal displacement of the villafranchian succession body along the scarp. there is also a cut in the continuity of the fluvial sediments connected to the ancient courses of the po and tanaro rivers. the deviation of these rivers, responsible for their present courses (7 and 8 in fig. 1), has essentially been caused by the pleistocene deformation. the scarp’s morphological features, with deep valleys draining in the opposite direction and an asymmetric transverse cross section, as well as fig. 1, structural map of the studied area. 1) t. traversola deformation zone (prevailing dextral strike-slipe displacement); 2) c. fagliaverde fault zone (prevailing vertical displacement); 3) castelnuovo fault zone (prevailing vertical displacement); 4) asti syncline axis; 5) po river ancient course; 6) tanaro river ancient course; 7) po river present course; 8) tanaro river present course. earth observing system data and information system (eosdis). 2009. earth observing system clearinghouse (echo) / warehouse inventory search tool (wist). greenbelt, md: eosdis, goddard space flight center (gsfc) national aeronautics and space administration (nasa). schema strutturale dell’area studiata. 1) zona di deformazione del t. traversola (con movimento prevalentemente trascorrente destro); 2) zona di faglia di cascina fagliaverde (con movimento prevalentemente verticale); 3) zona di faglia di castelnuovo (con movimento prevalentemente verticale); 4) asse della sinclinale di asti; 5) antico percorso del f. po; 6) antico percorso del f. tanaro; 7) percorso attuale del f. po; 8) percorso attuale del f. tanaro. a. doglione, m.g. forno & m. 103 ms. received: testo ricevuto il the monferrato. from middle pliocene to present-day, the torino hill northward translation and uplift, induce a rfdz dextral strike-slipe tectonic (laubscher et al., 1992; piana & polino, 1995). according to the new collected data, this tectonic activity can be responsible of the t. traversola deformation zone develop. references alessio m., allegri f., ambrosetti p., bartolomei g., bella f., belluomini g., calderoni g., carraro f., charrier g., cortesi c., esu d., forno m. g., improta s., manfra l. & petrone v. (1982) il giacimento fossilifero pleistocenico superiore di moncucco torinese. geogr. fis. dinam. quatern., 5, 219-239. boano p., forno m. g. & giardino m. (1997) deformazioni sinsedimentarie nella successione villafranchiana presso castelnuovo don bosco (asti). il quaternario it. journ. quatern. sc., 10 (2), 355-358. boano p. & forno m. g. (1999) la successione “villafranchiana” nell’area di castelnuovo don bosco (asti). il quaternario it. journ. quatern. sc., 12 (2), 161 -194. carraro f. (ed.) (1996) revisione del villafranchiano nell'area-tipo di villafranca d'asti. atti del convegno: "il significato del villafranchiano nella stratigrafia del pliopleistocene" (peveragno (cn)-villafranca d'asti (at), 20-24 giugno 1994). il quaternario it. journ. quatern. sc., 9 (1), 98-101. carraro f. & valpreda e. (1991) the middle-upper quaternary of the asti basin. il quaternario it. journ. quatern. sc., 4 (1), 151-172. castiglioni b. (1934) sulle cause delle deviazioni dei fiumi. zeitsch. geomorph., 8/5. forno m. g. (1980) evidenza di un drenaggio abbandonato nel settore settentrionale dell'altopiano di poirino (torino). geogr. fis. dinam. quatern., 3, 61-65. forno m. g. (1982) studio geologico dell'altopiano di poirino (torino). geogr. fis. dinam. quatern., 5, 129162. piana f. & polino r. (1995) tertiary structural relationships between alps and apennines: the critical torino hill and monferrato area, nothwestern italy. terra nova, 7, 138-143. laubscher h., biella g.c., cassinis r., gelati r., lozej a., scarascia s. & tabacco i. (1992) -the collisional knot in liguria. geol. rndsch., 81, 275-289. the entrenchment of the ancient rivers in the east sector, the dissection of the east sector and the genesis of numerous landslides. other data also suggest some vertical displacement structures known as the c. fagliaverde fault zone and castelnuovo fault zone (2 and 3 in fig. 1) (carraro ed., 1996; boano et al., 1997; boano & forno, 1999). the most significant are: the vertical displacement of the type-area villafranchian succession (middle pliocene-lower pleistocene), the stratigraphic interference along the structures and the local presence of re-sedimented bodies. further data suggest, at least, the presence of a major strike-slipe displacement structure; only a short segment of which has been reported in the literature (op. cit.). the most significant data are: the horizontal displacement of the asti syncline axis (4 in fig. 1), the horizontal displacement of the villafranchian body and the lateral sliding of rivers (ancient courses of the po and tanaro rivers (5 and 6 in fig. 1). in conclusion, the described scarp (fig. 2) is the morphologic expression of an important and continuous deformation zone, characterized by main dextral strike-slipe displacement, presumably localized near the scarp. these new data explain an old observation (castiglioni, 1936) that reports the relative stability of the scarp over time: this observation was in conflict with the proposed genesis, connected exclusively to regressive fluvial erosion, and could not be explained. it was impossible to envisage how a high scarp, shaped in incoherent sediments, could not be affected by the regressive erosion. in view of the reported observations it is highly likely that the exceptional morphologic expression of the t. traversola deformation zone and its relatively stable position are connected to its probable recent activity. in the early pliocene, the apennine tectonic became to affect the torino hill inducing dextral activations of the rio freddo deformation zone (rfdz) (piana & polino, 1995). this nnw-sse deformation zone, developed a few kilometres nne the studied area, divides the torino hill by fig. 2, the described scarp evidence evidenza della scarpata descritta gattiglio new morphological, stratigraphic, structural ... january 14, 2011 14 gennaio 2011 stratigrafia della sequenza cataglaciale nei colli di ivrea e dati pollinici preliminari sui depositi lacustri di chiaverano (torino) maria gabriella forno1, franco gianotti1, federico grosso1 & roberta pini2 1dipartimento di scienze della terra, università di torino, via valperga caluso 35, 10125 torino 2laboratorio di palinologia e paleoecologia, cnr istituto per la dinamica dei processi ambientali, piazza della scienza 1, 20126 milano riassunto: forno m. g., gianotti f., grosso f. & pini r., stratigrafia della sequenza cataglaciale nei colli di ivrea e dati pollinici preliminari sui depositi lacustri di chiaverano (torino). (it issn 0394-3356, 2007). in occasione della revisione delle conoscenze geologiche sull’anfiteatro morenico d’ivrea (ami) in corso negli ultimi anni da parte degli autori, è stata presa in esame con particolare dettaglio l’area dei “colli di ivrea”, sviluppati nel settore marginale sinistro della depressione interna e sospesi fino ad alcune centinaia di metri rispetto all’incisione attuale del f. dora baltea. quest’area, nota da tempo per le forme di esarazione glaciale in roccia, è caratterizzata dalla diffusione dei rilievi montonati, tra cui sono interposte numerose depressioni lacustri. il rilevamento geologico di questo settore ha evidenziato come, accanto a queste forme di esarazione, siano conservati in modo discontinuo sedimenti glaciali, che costituiscono cordoni morenici frontali concentrici con altezza di alcuni metri; la distribuzione dei depositi, non considerati nei contributi precedenti, suggerisce lo sviluppo di un lobo glaciale in progressivo ritiro, collegato al fianco sinistro del ghiacciaio della dora baltea. queste evidenze, distribuite in posizione più interna e a quote notevolmente minori rispetto ai cordoni principali ("serra d'ivrea" e "piccola serra"), sono riferibili ad una sequenza di stadi cataglaciali successivi allo stadio di acme dell'ultimo episodio glaciale. lo studio pollinico preliminare di alcuni campioni di sedimenti lacustri e palustri provenienti dalla torbiera di tomalino, in comune di chiaverano, e il confronto con la successione pollinica di un altro bacino lacustre dell’anfiteatro (lago sirio) indicano che vi erano localmente condizioni di sedimentazione lacustre almeno a partire dalla prima parte dell’interstadiale bølling-allerød del tardoglaciale. abstract: forno m. g., gianotti f., grosso f. & pini r., stratigraphy of the cataglacial sequence in the “colli d’ivrea” area and preliminary pollen data of the chiaverano lacustrine deposits (torino). (it issn 0394-3356, 2007). the geological history of the ivrea morainic amphitheatre (ami) and of the “colli d’ivrea” area is currently under detailed revision. the colli d’ivrea area is located in the marginal left sector of the inner depression of the amphitheatre, some hundreds meters above the present-day incision of the dora baltea river. this area, well-known for the occurrence of subglacial bedrock landforms, is characterized by widespread roches moutonnées. the geological survey of this area revealed that these landforms are locally accompanied by a depositional record, locally developed, not recognized by previous authors: this record is testified by the presence of frontal and concentric morainic ridges, some meters-high, discontinuously preserved. the morainic evidence suggests a glacial lobe in progressive withdrawal, connected to an inner position of the glacier compared to the main ridges. the preliminary pollen analysis of the tomalino lacustrine-palustrine deposits (chiaverano) and the comparison with another pollen record from the amphitheatre (lago sirio) suggest that lacustrine sedimentation locally developed since the first part of the late-glacial interstadial of bølling-allerød parole chiave: chiaverano, sondaggi, analisi pollinica, tardoglaciale, olocene. keywords: chiaverano, corings, pollen analysis, late glacial, holocene. il quaternario italian journal of quaternary sciences 20(2), 2007 213-228 1. introduzione l’anfiteatro morenico d’ivrea (ami), alimentato dal bacino della valle d'aosta, è uno dei maggiori anfiteatri del versante meridionale delle alpi (fig. 1). questo complesso edificio morenico si estende per oltre 500 km2 a partire dallo sbocco della valle della dora baltea, occupando un vasto settore della pianura padana tra il settore alpino e il margine settentrionale dei rilievi collinari (collina di torino monferrato). si compone di alcune decine di cerchie moreniche concentriche, che circondano una vasta depressione interna con estensione di circa 200 km2, colmata dai depositi alluvionali del f. dora baltea. l'estensione e la marcata evidenza morfologica dell'ami impressionarono i diversi autori, tanto da definirlo “il più chiaro, il più parlante, il più imponente fatto geologico dell’alta valle del po” (gastaldi, 1869) e “le plus considérable des amphitéatres de la glaciation alpine” (penck et al., 1894). l'elemento più rappresentativo è la morena laterale sinistra nota come “serra d’ivrea”, già definita “la maggiore morena delle alpi” (penck & brückner, 1909): la serra è formata da sette principali cordoni morenici subparalleli, costituenti un complesso laterale di notevole regolarità, con lunghezza di oltre 20 km e con dislivello fino a 700 m sopra il fondovalle. se la serra è la massima espressione della sedimentazione glaciale, i cosiddetti colli di ivrea rappresentano un'evidente testimonianza dell’attività erosiva del ghiacciaio: sono un gruppo di rilievi rocciosi montonati e perfettamente levigati, emergenti dalla piana interna con dislivello fino a 250 m e per 20 km2 di estensione (figg. 2 e 3). l'area dei colli costituisce uno dei migliori esempi di settori in cui sono osservabili le forme di modellamento subglaciale a varia scala; racchiude inoltre cinque bacini lacustri di esarazione glaciale (laghi sirio, pistono, s. michele, campagna e nero) e vari altri stagni e torbiere (tra cui la vasta 214 m.g. forno et.al. torbiera di tomalino e l'ex-lago coniglio). volendo conoscere la successione stratigrafica di una delle maggiori conche di esarazione, la torbiera di tomalino a sud di bienca, in comune di chiaverano (380 m slm), è stato effettuato un sondaggio geognostico (tom 1) con un penetrometro leggero provvisto di carotiere: la finalità di questo sondaggio era di indagare l'intera successione di colmamento del bacino e di verificare l'esistenza alla base di livelli precedenti l'ultimo episodio glaciale. il sondaggio, con profondità di 4,60 m, è stato realizzato al centro dell’estremità meridionale del bacino, in una posizione sufficientemente distante da possibili apporti gravitativi provenienti sia dal versante morenico sovrastante bienca sia dai rilievi montonati che circondano la torbiera. due altri sondaggi (tom 2 e tom 3), effettuati nello stesso sito a pochi metri di distanza l'uno dall'altro per tentare di approfondire le indagini, hanno permesso solo di recuperare tratti discontinui di carota entro i primi 5 m di profondità. si è quindi proceduto a definire con maggior precisione il significato climatico e cronologico dei termini più recenti della successione attraverso un'analisi palinologica. sono state estratte due serie di campioni di depositi lacustri e palustri in sequenza verticale (vedi fig. 12), con distanza l'uno dall'altro di 10 e 20 cm per i livelli più profondi (recuperati attraverso tom 2) e di 100 cm per i livelli sommitali (tom 3), sui quali uno degli autori (r. p.) ha condotto uno studio pollinico preliminare. 2. inquadramento geologico come desunto dalla letteratura geologica, quest’area si sviluppa (fig. 2) al contatto tettonico tra zona sesia-lanzo (sistema austroalpino), zona del canavese e zona ivrea-verbano (sistema sudalpino). le prime due unità sono messe a contatto dalla linea del canavese esterna (biino & compagnoni, 1989), espressione locale della linea insubrica o periadriatica; una seconda faglia, nota come linea del canavese interna (biino & compagnoni, 1989), parallela alla principale, mette a contatto la zona del canavese con la zona ivrea-verbano. la zona sesia-lanzo è costituita da micascisti eclogitici (compagnoni et al., 1977; venturini, 1995). la fig. 1 mappa schematica del bacino della dora baltea, corrispondente alla valle d'aosta e all'anfiteatro morenico di ivrea. la suddivisione stratigrafica dell'anfiteatro è desunta dalle carte geologiche di carraro et al. (1975) e di carraro (1992), semplificate e modificate. lo schema degli stadi di ritiro è quello di gianotti (2007). sketch map of the dora baltea basin corresponding to the aosta valley region and to the morainic amphiteatre of ivrea. stratigraphical subdivision of the amphiteatre is from geological maps of carraro et al. (1975) and carraro (1992), simplified and modified. scheme of glacial retrait stadials is from gianotti (2007). zona del canavese è costituita da un substrato prepermiano (scisti di basso grado intrusi da graniti e dioriti) e da una copertura permo-mesozoica (rioliti, quarziti, calcari e dolomie) (baggio, 1965). la zona ivrea verbano infine è formata da prevalenti granuliti basiche, originatesi a livelli crostali profondi (zingg et al., 1990). i primi elevati rilievi alpini sono modellati nelle 215stratigrafia della sequenza cataglaciale ... rocce della zona sesia-lanzo; i più bassi colli d'ivrea sono modellati prevalentemente entro le rocce della zona ivrea-verbano e subordinatamente nel complesso magmatico-sedimentario della zona del canavese: per questo motivo in letteratura sono meglio noti come "colli dioritici di ivrea". fig. 2 carta geologica schematica dell’area in esame. geological sketch map of the colli d'ivrea area. 216 3. lavori precedenti la successione stratigrafica dell'ami è oggetto di studio a partire dalla seconda metà dell'800: la genesi glaciale della serra d'ivrea fu riconosciuta dai geologi svizzeri studer (1844) e guyot (1847); il primo lavoro organico sull'ami è opera di martins & gastaldi (1850). inizialmente l'anfiteatro veniva collegato ad una sola grande glaciazione e dunque trattato come un insieme omogeneo, differenziabile solo dal substrato pre-glaciale (lavori di gastaldi, bruno, baretti, marco e sacco della seconda metà dell''800). penck et al. (1894) e penck & brückner (1909) riferiscono l'ami alle ultime due glaciazioni alpine (riss e würm) proposte nella loro classica stratigrafia. nella prima edizione della “carta geologica d’italia” alla scala 1:100.000, foglio 42 “ivrea” (franchi et al., 1912) e foglio 43 “biella” (franchi & stella, 1933) i cordoni esterni alla serra sono indicati come “morene antiche (prewürmiane)”, mentre quelli interni (serra e piccola serra) come “morene würmiane, postwürmiane e recenti”. successivamente sacco (1927) suddivide i depositi dell’anfiteatro in tre unità, correlate dubitativamente con il mindel, riss e würm di penck & brückner (1909), denominate rispettivamente “formazione morenica vecchia", riferibile alla prima glaciazione "(mindeliana ?)”, “formazione morenica media", riferibile alla seconda glaciazione "(rissiana?)” e “depositi morenici" attribuibili alla terza glaciazione "(würmiana?)”. la prima corrisponde alle forme più esterne dell’anfiteatro; la seconda, indicativa di una glaciazione con maggiore estensione, comprende la maggior parte dei cordoni intermedi, tra cui il più continuo, noto come serra di ivrea; la terza corrisponde alla cerchia morenica più interna, sviluppata tra andrate e bollengo in sinistra, nota come piccola serra, e tra strambino e parella in destra. le prime analisi polliniche e datazioni 14c dell'ami si devono a schneider (1978), che studia le sequenze tardoglaciali e oloceniche di vari siti in alcuni anfiteatri morenici sudalpini (trana nell'anfiteatro di rivoliavigliana; "torfsee", lago di viverone e torbiera di alice superiore nell'anfiteatro di ivrea; lago di biandronno nell'anfiteatro del verbano). in particolare nel torfsee, una piccola palude a ne del lago sirio a q. 250, il sondaggio interessa i primi 5 m di una sequenza di depositi lacustri e palustri riferibili all'intervallo di tempo compreso tra l'oldest dryas e il boreale. nella più estesa torbiera di alice superiore, a q. 570 nel settore laterale destro dell'ami (fig. 2), sono effettuati 3 sondaggi di circa 5 m ciascuno, che anche in questo caso non danno un riferimento più antico dell'oldest dryas. legni e torbe a cyperaceae estratti da uno di questi sondaggi forniscono età 14c comprese tra 11.720±240 a bp e 5.140±100 a bp. dal secondo sondaggio è ottenuta, alla profondità di 380-390 cm entro gyttja argil loso, la più antica età radiocarbonio (14.200±150 a bp) disponibile per l'ultimo episodio glaciale nell'ami: questa data, non calibrata, è quindi considerata dagli autori successivi come età minima di deglaciazione per l'ami. più in alto nella sequenza sono state ottenute le ulteriori età di 12.390±160 a bp e 11.660±90 a bp. altri studi sulla successione stratigrafica dell’anfiteatro vengono effettuati da carraro per la seconda edizione del foglio "biella" della carta geologica d'italia (bortolami et al., 1966; 1967; carraro & petrucci, 1969; carraro et al., 1975). l'autore dapprima conferma sostanzialmente i tre complessi individuati in precedenza da sacco (1927); in seguito suddivide la successione in tre gruppi secondo criteri allostratigrafici (carraro, 1992). in particolare il gruppo di san micheleborgo comprende i cordoni morenici più esterni, di dimensioni relativamente ridotte, riferiti su base paleomagnetica e pedostratigrafica al pleistocene inferioremedio (carraro et al., 1991): l’età antica è suggerita dalla presenza di suoli di colore rosso (2.5yr÷10r), con notevole spessore conservato, e dal sensibile rimodellamento delle forme, responsabile della cancellazione dell’originaria espressione morfologica. il gruppo della serra, corrispondente “all’ossatura dell’anfiteatro”, comprende invece la maggior parte dei cordoni morenici conservati; la forma più significativa è rappresentata dalla serra d’ivrea, riferita su base pedostratigrafica al pleistocene medio: l’età intermedia è indicata dalla presenza di suoli molto meno evoluti, con indice di colore 7.5yr, e da un diffuso rimodellamento delle forme, che tuttavia non oblitera l’originaria espressione morfologica dei cordoni. il gruppo di bollengo-albiano infine comprende le cerchie più interne dell’anfiteatro, sviluppate a quota inferiore, riferite su base pedostratigrafica al pleistocene superiore ed in particolare all’ultima pulsazione glaciale (comprendente i l last glacial maximum): l’età recente è suggerita dalla presenza di suoli poco potenti di colore bruno-giallastro e da un modesto rimodellamento delle forme. gli studi successivi, riguardanti aree più circoscritte dell’anfiteatro, permettono di effettuare localmente una suddivisione più dettagliata del gruppo più antico. in particolare gianotti (1993), prendendo in esame parte del settore laterale sinistro, suddivide ulteriormente il gruppo di san michele-borgo in quattro unità allostratigrafiche corrispondenti all’unità di s. michele-borgo (già individuata da carraro et al., 1991) e alle unità di bornasco, di zubiena e di parogno. forno & lucchesi (2000), effettuando un rilevamento geologico di dettaglio del cordone più esterno del settore sinistro dell’anfiteatro, riconoscono la presenza di diverse facies all’interno dell’unità di s. michele-borgo, interpretandole come ”subglacial lodgment till, supraglacial melt-out till, ice-marginal deformation till e ice-marginal gravity flowtill”, di cui analizzano il diverso significato genetico. segnalano inoltre la presenza di depositi più antichi, indicati rispettivamente come unità di chiave e unità di donato, la prima costituita da depositi di delta-conoide del bacino del f. dora baltea, riferibili al pliocene superiore pleistocene inferiore p.p., e la seconda costituita da depositi fluviali dei corsi d'acqua locali, riferibili al pleistocene inferiore. infine gianotti (2007) distingue nell'ami dieci alloformazioni, riferibili ognuna ad un differente episodio glaciale in quanto separate da intercalazioni interglaciali/interstadiali, corrispondenti a depositi palustri con contenuto organico e a paleosuoli, e in parte differenziate su base pedostratigrafica. nell'ambito di questa successione, l'al loformazione più recente (alloformazione di ivrea), riferibile all'ultimo episodio glaciale (25-11,5 ka bp), comprende la piccola serra (stadio di acme glaciale) e la totalità dei depositi distribuiti sui colli d'ivrea (stadi cataglaciali). m.g. forno et.al. 217 4. studio geologico la successione stratigrafica dell’anfiteatro morenico d’ivrea è già conosciuta nelle caratteristiche essenziali; come nella maggior parte delle successioni continentali, ed in particolar modo in quelle di ambiente glaciale, si ha un numero molto ridotto di elementi cronologici di riferimento che permettano di inserirla univocamente in un preciso contesto stratigrafico. durante lo studio tutt'ora in corso riguardante l’anfiteatro morenico nel suo insieme (f. gianotti), è stato svolto da uno degli autori (f. grosso) un rilevamento geologico di dettaglio della parte settentrionale dei “colli di ivrea” (grosso, 2005; forno et al., 2005), un gruppo di rilievi di esarazione glaciale che si elevano nel mezzo della conca interna dell'ami (fig. 3): questi rilievi, allungati complessivamente in direzione ne-sw trasversalmente alla valle principale, corrispondono all'emergenza del substrato roccioso sudalpino. nel dettaglio la morfologia dei colli d'ivrea, del tutto peculiare (fig. 4), è caratterizzata da un elevato tasso di affioramento del substrato roccioso, che costituisce raggruppamenti di rilievi caratterizzati da un profilo arrotondato, con dislivelli di ordine decametrico fino ad un massimo di 200 m. i rilievi raggiungono la quota massima di 519 m (c. montesino) e si innalzano di 100250 metri sulla pianura alluvionale attuale del f. dora baltea (fig. 2). conservano diffuse e tipiche forme di esarazione glaciale: particolarmente evidenti sono estese superfici montonate, talvolta perfettamente levigate (fig. 5), percorse da solchi (grooves) e incise da strie glaciali. dall'orientazione delle strie si ricava la direzione di movimento della base del ghiacciaio, verso e e se nel settore orientale dei colli, più esterno, e verso s e sse in quello occidentale, più interno. i rilievi sono separati da depressioni in parte occupate tuttora da bacini lacustri e in parte corrispondenti invece a bacini lacustri colmati: i bacini ospitano localmente torbiere galleggianti note come "terre ballerine". l'affioramento di rocce con diversa erodibilità e la presenza di discontinuità tettoniche ha fortemente condizionato l’evoluzione geologica e morfologica dell’area: i rilievi si sviluppano prevalentemente nei settori costituiti da rocce resistenti (graniti, dioriti e granuliti) con modesta fratturazione; le depressioni lacustri risultano invece distribuite in coincidenza delle litologie a tessitura scistosa o milonitica, come nel caso degli scisti entro cui è modellato il bacino del lago nero, e lungo fasce tettonizzate, caratterizzate da elevata fratturazione. l'esempio più significativo in questo caso è dato dall'allineamento delle depressioni della torbiera di tomalino e del lago pistono, in coincidenza della linea del canavese interna (lci in fig. 2). il modellamento erosionale dei colli di ivrea, espresso da forme di esarazione a varia scala ampiamente distribuite e ben conservate, era già stato riconosciuto dagli autori precedenti. nessun autore aveva mai indicato la presenza di una ridotta copertura quaternaria, probabilmente a causa dell'esiguità delle tracce deposizionali rispetto all'evidenza delle forme di esarazione e per la maestosità dei cordoni morenici principali circostanti. lo stesso foglio “ivrea” della carta geologica d'italia segnala soltanto le torbiere principali al di sopra del substrato roccioso (franchi et al., 1912). con il nuovo rilevamento è stata invece evidenziata la presenza, direttamente sui rilievi montonati, sia di singoli elementi di trasporto glaciale (massi erratici) con costituzione petrografica differente rispetto al substrato locale (fig. 6), sia di un numero limitato di lembi circoscritti di depositi glaciali a blocchi, corrispondenti essenzialmente a till di margine glaciale, in gran parte till di colata (marginal flow till; fig 7). questi lembi sono distribuiti sui fianchi, alla base o sulla sommità dei rilievi montonati e risultano particolarmente diffusi nel settore settentrionale dei colli, dove dall'interpolazione dei vari fig. 3 il settore laterale sinistro dell'ami, evidenziato dalla presenza della serra d'ivrea, e l'estesa depressione interna in cui si sviluppano i colli d'ivrea. the left lateral sector of the morainic amphiteatre of ivrea, with serra d'ivrea moraine and the wide internal depression hosting colli d'ivrea (ivrea hills). stratigrafia della sequenza cataglaciale ... 218 fig. 4 panoramica e carta geologica del settore settentrionale dei colli d'ivrea, che racchiudono la depressione di tomalino, colmata da sedimenti lacustri e torbe. l'asterisco indica la posizione dei sondaggi effettuati. panoramic view and geological map of the northern sector of colli d'ivrea, with the tomalino depression filled by lacustrine deposits and peat. the asterisk shows the boreholes position. m.g. forno et.al. lembi si ricostruisce, non senza difficoltà, una successione di cerchie moreniche concentriche. i depositi, osservabili diffusamente in superficie o in rari affioramenti sempre di ridotta estensione, sono costituiti da elementi con dimensioni tra centimetriche e metriche e forma da subangolosa a sfaccettata e subarrotondata, mescolati ad una abbondante matrice sabbiosa debolmente limosa, con tessitura prevalentemente a supporto di matrice; si presentano massivi o con un accenno di stratificazione inclinata. gli elementi, prevalentemente non alterati, sono costituiti da gneiss e micascisti eclogitico-glaucofanici, eclogiti, glaucofaniti, quarziti di vena, ortogneiss e gneiss in facies scisti verdi, della zona sesia-lanzo, mescolati a graniti retrocessi e dioriti, vulcaniti acide e quarziti sedimentarie, provenienti dai colli di ivrea modellati nella zona del canavese; subordinati sono i clasti di serpentiniti della zona piemontese e di metaconglomerati della zona houillére (sistema pennidico esterno), affioranti nel tratto superiore del bacino della dora baltea. la matrice appare scarsamente selezionata, con debole frazione siltoso-argillosa, di colore da grigio a grigio-giallastro chiaro. i depositi mostrano uno spessore di ordine metrico, fino ad un massimo di una decina di metri ad w di bienca e sulla cresta di p. montesino (figg. 4 e 8). localmente sui depositi sono conservati prodotti colluviali di suoli di colore bruno-giallastro (7.5yr 5/6,8). questi sedimenti hanno scarsa evidenza morfologica, corrispondendo a cordoni morenici laterali e frontali discontinui, con lunghezza ridotta, al massimo di alcune centinaia di metri, e altezza di ordine metrico (fig. 8): malgrado la discontinuità dei lembi, si sono potute ricostruire cinque cerchie concentriche, indicative di altrettanti episodi di stazionamento del margine glaciale nell'ambito del più generalizzato ritiro dalla posizione di massima espansione (fig. 2). i sedimenti descritti sono infatti distribuiti sensibilmente all’interno rispetto alle cerchie principali: le unità più antiche formano imponenti cordoni morenici laterali (serra d’ivrea e piccola serra), circa rettilinei e continui, con sviluppo altimetrico superiore al centinaio di metri, e conservano depositi glaciali con spessore rilevante, compreso tra 50 e 150 m (fig. 9). le morene della serra e della piccola serra esprimono lo stadio di massima espansione del ghiacciaio balteo negli ultimi episodi glaciali documentabili in anfiteatro (gianotti, 2007). le morene ospitate nella parte prossimale della depressione interna sono riferibili invece a stadi di ritiro dell'ultimo episodio glaciale: in particolare quelle del settore di bienca sono connesse con la formazione di un lobo glaciale in progressivo ritiro, alimentato dal fianco sinistro del 219 fig. 5 esempio di superfici levigate e striate su granuliti basiche (chiaverano). an example of polished and striated surfaces on basic granulites (chiaverano). fig. 6 masso erratico di granito sulla sommità di rilievo montonato a se del lago nero, modellato su scisti del basamento della zona del canavese. erratic boulder of granite on top of a roche moutonnée at se of lago nero, on schist of canavese zone basement. stratigrafia della sequenza cataglaciale ... ghiacciaio principale, quando questo si era ormai ritirato dal settore esterno dei colli (cfr. fig. 2). nel presente lavoro si intendono evidenziare i risultati ottenuti da studi di dettaglio effettuati su sedimenti palustri deposti in una depressione sviluppata all’interno del piccolo anfiteatro di lobo glaciale citato (lobo di bienca). in corrispondenza di questa depressione sono state riconosciute tre facies sedimentarie deposte in acqua, con caratteristiche che permettono di r icondurle a situazioni deposizionali ben distinte: depositi glaciolacustri marginali di kame, depositi glaciolacustri di sbarramento glaciale ed infine depositi lacustri e palustri post-glaciali (il termine di "post-glaciale" è qui inteso nell'accezione di bini et al., 2004). queste tre facies, in appoggio diretto sul substrato roccioso dei colli o sui depositi glaciali, rappresentano le testimonianze di episodi deposizionali che si ripetono a quote progressivamente inferiori in aree via via più interne, collegate con l'abbassamento del margine glaciale fino al suo completo ritiro (fig. 10). con riferimento al bacino di tomalino a sud di bienca (cfr. fig. 4), attualmente colmato, il corpo sedimentario più elevato ed antico (1 in fig. 10) è formato in genere da sabbie limose, con ciottoli sparsi e rare intercalazioni di sabbie meglio selezionate, entrambe prive di contenuto organico; talvolta è invece costituito da elementi angolosi di varia dimensione mescolati a una matrice sabbiosa meglio selezionata e stratificata. questi sedimenti, con spessore osservabile di alcuni metri, sono interpretabili come depositi glaciolacustri marginali, alimentati sia da apporti provenienti dal ghiacciaio (till di colata acquatici e depositi di delta-conoide) sia da apporti gravitativo-colluviali provenienti dal versante; formano lembi sedimentari “applicati” sul fianco di cordoni morenici o di rilievi in roccia, sospesi di oltre una decina di metri rispetto alla superficie di colmamento del bacino lacustre; l'espressione morfologica è rappresentata da lembi di superfici pianeggianti terrazzate, distribuite al margine del bacino a quote variabili, interpretabili come terrazzi di kame alimentati direttamente dal ghiacciaio. il corpo sedimentario intermedio (2 in fig. 10) è costituito da sabbie limose a stratificazione massiva, con sporadici elementi angolosi prevalentemente centimetrici, in gran parte provenienti dal substrato locale; ha come espressione morfologica lembi di superfici 220 fig. 7 till di colata di posizione marginale, deformato, caratterizzato da stratificazione inclinata. deformed marginal flow till with inclined stratification. fig. 8 il cordone morenico allungato sulla sommità della p. montesino, rilievo più elevato dei colli d'ivrea. the morainic crest exstended on p. montesino, the highest relief of colli d'ivrea. m.g. forno et.al. orizzontali, distribuiti lungo il bordo della conca lacustre e sospesi di circa 4 m rispetto alla superficie di colmamento del bacino. questi lembi rappresentano l'espressione morfologica di sedimenti glaciolacustri di sbarramento glaciale: tali depositi non possono essere definiti di posizione marginale, come i precedenti, perchè sedimentati in un bacino glaciolacustre esteso fino a considerevole distanza dal ghiacciaio. il corpo sedimentario più recente (3 in fig. 10) è formato da depositi sabbioso-limosi e argillosi, passanti verso l'alto a limi e argille ricchi di sostanza organica (gyttja) e a torbe, interpretabili come depositi lacustri e palustri post-glaciali, indicativi di un bacino lacustre non più in alcun modo collegato con il ghiacciaio: questi sedimenti costituiscono il riempimento dell'attuale bacino colmato. i sondaggi hanno attraversato la parte sommitale del corpo sedimentario più recente, costituente il colmamento lacustre e palustre del bacino di tomalino (figg. 4 e 12). in particolare le sabbie fini argillose della 221 fig. 9 i colli d'ivrea delimitati dagli imponenti cordoni della serra d'ivrea e della piccola serra. the colli d'ivrea bounded by serra d'ivrea and piccola serra big moraines. fig. 10 schema dei rapporti stratigrafici della depressione lacustre di tomalino. stratigraphical scheme of the tomalino lacustrine depression. stratigrafia della sequenza cataglaciale ... parte basale della sequenza attraversata, sotto i 4 m di profondità, hanno colore biancastro e sono localmente ricche di gusci di gasteropodi e più rari bivalvi lacustri, con dimensioni medie di 2-3 mm fino a 5 mm. la gyttja, prevalente tra 4 m e 3,50 m di profondità, contiene resti vegetali decomposti, con frammenti di macrofite indistinguibili, che conferiscono al deposito un colore nerastro. la parte superiore della successione, tra 3,50 m e il piano campagna, è costituita da livelli torbosi compressi di spessore pluridecimetrico, che chiudono la sequenza palustre: le torbe campionate tra 1 e 1,35 cm sono di colore brunastro e sono asciutte; al di sotto risultano invece nerastre e sature d'acqua, indicando che la posizione della superficie della falda libera si attestava tra 1,40 e 2 m di profondità al momento della realizzazione del sondaggio tom 1 (15/07/2004). 5. studio del contenuto pollinico sei campioni di sedimento sono stati prelevati dai depositi della torbiera di tomalino, preparati ed analizzati presso il laboratorio di palinologia e paleoecologia del cnr-idpa di milano. per la preparazione dei campioni è stata applicata la cosiddetta procedura ‘standard’, che prevede una serie di successivi attacchi chimici finalizzata alla rimozione della componente minerale e alla riduzione di quella organica non pollinica. i preparati, conservati in glicerina, sono stati montati su vetrini e analizzati al microscopio ottico a 400, 630 e 1000 ingrandimenti. per l’identificazione dei granuli pollinici sono stati usati chiavi dicotomiche (moore et al., 1991), atlanti fotografici (punt & blackmore, 1976-1995; reille, 1992-1995) e la collezione di confronto del cnr–idpa. sono stati inoltre identificati alcuni tipi di alghe d’acqua dolce, spore di pteridofite ed extrafossili (sensu van geel, 1978). i risultati dell’analisi pollinica sono presentati in tab. 1 e fig. 11. le percentuali polliniche sono state calcolate a partire da una somma pollinica che comprende alberi, arbusti e piante erbacee di ambiente terrestre; piante di ambiente acquatico e palustre, alghe e spore di pteridofite non sono invece comprese nella somma pollinica. e’ stata inoltre calcolata la concentrazione delle microparticelle di carbone di lunghezza maggiore di 10 µm contenute nel sedimento, espressa come numero di particelle per grammo di sedimento. 5.1 ricostruzione paleoambientale i dati pollinici ottenuti permettono di fare alcune osservazioni circa le condizioni 222 fi g. 1 1 d ia gr am m a p ol lin ic o % a c ur ve s el ez io na te d ei c am p io ni d i s ed im en to d el la t or b ie ra . % p ol le n d ia gr am (o nl y se le ct ed t ax a ar e sh ow n) o f t he s am p le s fr om t he t om al in o m ire . m.g. forno et.al. 223 tab. 1 tabella di analisi pollinica relativa ai campioni provenienti dalla torbiera di tomalino. results of pollen analysis carried out on the sediment samples from the tomalino mire. stratigrafia della sequenza cataglaciale ... paleoambientali al momento della deposizione dei sedimenti analizzati. sondaggio tom 2 da questo sondaggio provengono tre campioni di sedimento, prelevati a 430 cm di profondità dal p.c (argilla sabbiosa), a 420 cm (argilla sabbiosa con resti di molluschi) e a 403 cm (gyttja) . in questi campioni il polline di alberi e arbusti si attesta su valori compresi tra 74-84% (tab. 1) ad indicare che i sedimenti in esame si sono deposti in un contesto caratterizzato da densa copertura arborea. il campione più profondo (tom 2-430 cm) contiene elevate percentuali poll iniche di pinus sylvestris/mugo e stomi di pino, che indicano la presenza di questa conifera nei dintorni del sito in esame. lo spettro pollinico è inoltre caratterizzato da buoni valori percentuali di betula (18%), da rari granuli di juniperus, hippophaë e salix e da valori di xerofite erbacee (artemisia, chenopodiaceae, helianthemum) attorno al 6%. sono inoltre presenti alghe d’acqua dolce (botryococcus e pediastrum). questo spettro è indicativo di foreste-steppe di ambiente boreale fresco. nel campione successivo (tom 2–420 cm) la percentuale pollinica di pinus sylvestris/mugo diminuisce nettamente (39%), mentre betula si attesta su valori attorno al 30%. sono stati rinvenuti alcuni granuli pollinici di larix: considerando la scarsa produttività e la limitata capacità di dispersione pollinica di questa conifera (de beaulieu & reille, 1992), il rinvenimento di pochi granuli pollinici può essere ritenuto indicativo della presenza del larice nei dintorni del sito in esame. sono presenti granuli sporadici di quercus caducifolia, tilia e ulmus. tra le erbacee di ambiente terrestre, sono ben rappresentate artemisia (7,6%), gramineae (8,5%) e rumex tipo acetosa (5%). anche questo spettro pollinico è indicativo di foreste-steppe di ambiente boreale fresco. il campione tom 2–403 cm contiene elevate percentuali polliniche di alnus tipo glutinosa (tipo pollinico che comprende alnus glutinosa e alnus incana) e di elementi del querceto misto (corylus, quercus caducifolia, tilia e ulmus). questo spettro indica la presenza di boschi misti di conifere e latifoglie di ambiente temperato. sondaggio tom 3 da questo sondaggio provengono tre campioni di sedimento, prelevati a 375 cm di profondità dal p.c. (argilla con resti organici), a 275 cm (gyttja/torba) e a 175 cm (torba). lo spettro pollinico del campione più profondo (tom 3-375 cm) è dominato da pinus sylvestris/mugo e da betula e registra la presenza di xerofite erbacee e arbustive. tale composizione pollinica è molto simile a quella del campione tom 2-430 cm ed è indicativa di foreste-steppe di ambiente boreale fresco. nel campione successivo (tom 3-275 cm) si osserva il brusco crollo dei valori % di pinus sylvestris/mugo, mentre le xerofite (artemisia, hippophaë, chenopodiaceae ed helianthemum) si attestano su valori attorno all’11%. lo spettro pollinico registra la presenza di alcune latifoglie termofile (corylus, fagus, quercus caducifolia, tilia e ulmus) che, ad eccezione della quercia, si attestano su valori inferiori all’1%. tra le piante erbacee terrestri sono presenti lythrum, scabiosa, phyteuma, tipo lotus. %). anche questo spettro pollinico è indicativo di foreste-steppe di ambiente boreale fresco. nel campione più superficiale tom 3-175 il tasso di afforestamento raggiunge valori piuttosto elevati (75%) cm, in gran parte dovuti a pinus sylvestris/mugo (57,6%). sono presenti betula (5,1%), quercus caducifolia (3,9%), salix (1%) e ulmus. anche in questo campione compaiono sporadici granuli di corylus e fagus, accompagnati da rubus e sorbus. questa composizione pollinica riflette la presenza di boschi misti di conifere e latifoglie. 5.2. interpretazione cronologica la suddivisione climatostratigrafica qui adottata fa riferimento a ravazzi ( in stampa). i l termine tardoglaciale viene usato per indicare l’insieme di eventi che si sono susseguiti tra l’ultima culminazione glaciale dell’ultima glaciazione e l’inizio dell’olocene. secondo orombelli et al. (2005) il tardoglaciale ha inizio al termine dell’ultimo massimo glaciale globale (19 ka); il limite cronostratigrafico superiore del tardoglaciale, assunto come limite pleistocene/olocene, coincide con l’età 14c di 10 ka bp (gradstein et al., 2004). la suddivisione del tardoglaciale in cronozone proposta inizialmente da firbas (1954) e ripresa da mangerud et al. (1974) è stata da tempo abbandonata e sostituita con una divisione climatostratigrafica che mette in evidenza una successione di eventi climatici sostanzialmente sincroni a scala continentale (litt et al., 2003) e alpina (vescovi et al., 2007). considerato l’esiguo numero di campioni studiati, le considerazioni biostratigrafiche hanno carattere preliminare. alcune indicazioni possono però essere derivate dal confronto con il diagramma pollinico del lago sirio (270 m slm; schneider, 1978), un bacino posto 2 km a sud della torbiera da noi esaminata. il diagramma pollinico del lago sirio è riferibile all’intervallo di tempo compreso tra il tardoglaciale e l’inizio dell’olocene (preboreale) (schneider, 1978). la stratigrafia pollinica non è supportata da datazioni 14c; la suddivisione in biozone è basata sul confronto con altri diagrammi pollinici datati provenienti dalla torbiera di alice superiore e del lago di biandronno (schneider, 1978) ed è correlata con la suddivisione in cronozone proposta da firbas (1954). la successione pollinica del lago sirio viene qui brevemente illustrata (con riferimento alle zone polliniche descritte da schneider, 1978) per mostrare i principali eventi che caratterizzano la storia della vegetazione di questo settore dell’ami. l’età di tali eventi viene invece dedotta dal confronto con i record pollinici del lago piccolo di avigliana (finsinger et al., 2006) e del lago di annone (wick, 1996), dove la stratigrafia pollinica è supportata da numerose datazioni 14c. la successione pollinica del lago sirio mostra che, durante le zone polliniche ia-c l’area attorno al bacino lacustre era caratterizzata da un basso tasso di afforestamento e dalla presenza di comunità erbacee di ambiente steppico (sia artemisia che gramineae oltre il 25-30%): larix aumenta progressivamente fino alla transizione con il bølling. la curva di pinus inizia ad aumentare durante la zona 224 m.g. forno et.al. pollinica ii e nella prima parte della zona iii, attestandosi su valori medi del 50%. durante questa fase larix è presente con curva pressoché continua. nella prima parte della zona iii, accanto a pinus, betula e artemisia, si registra la presenza di sporadici granuli di latifoglie termofile. la seconda parte della zona iii è caratterizzata da un’ulteriore espansione di pinus (fino quasi al 70%) e da una lieve riduzione delle xerofite. nelle zone iv e v si osserva la progressiva riduzione dei valori % di pinus e l’espansione delle latifoglie. il confronto con le successioni polliniche del lago piccolo di avigliana (finsinger et al., 2006) e del lago di annone (wick, 1996) consente di collocare le zone polliniche ia-c nell’intervallo di tempo che precede l’interstadiale bøllingallerød del tardoglaciale, la zona pollinica ii e la prima parte della zona ii i nell’ interstadiale b-a del tardoglaciale, la seconda parte della zona iii nel dryas recente, le zone iv e v nel preboreale. il confronto tra la successione pollinica del lago sirio e gli spettri pollinici ottenuti dai campioni di sedimento della torbiera di tomalino suggerisce che: i sedimenti rappresentati dai campioni tom 2-430 cm, tom 2-420 cm e tom 3-375 cm si sarebbero deposti durante la prima metà dell’interstadiale bølling-allerød del tardoglaciale. tale ipotesi si fonda su valori % di pinus elevati (talora oltre il 60%), assenza di latifoglie termofile e valori consistenti di xerofite (5-7%), ma molto più bassi rispetto alle composizioni tipiche della prima parte del tardoglaciale. il campione tom 2-403 cm, per la presenza di corylus e quercus con moderate percentuali, e l’elevato contenuto di alnus potrebbe essere attribuito alla parte iniziale del preboreale (11.500 – 10.500 anni cal bp). i sedimenti rappresentati dai campioni tom 3-275 cm e tom 3-175 cm potrebbero essere attribuiti alla parte finale dell’interstadiale b-a o al dryas recente: i dati raccolti non consentono una più precisa attribuzione cronologica. si esclude un’attribuzione all’olocene per i bassi valori % di quercus e la ancora elevata presenza di artemisia. 6. considerazioni conclusive l’insieme delle osservazioni effettuate consente di ricostruire la successione degli eventi che hanno caratterizzato l’evoluzione geologica dell'area nel corso dell'ultimo massimo glaciale ed in particolare del tardoglaciale. il riconoscimento, al di sopra dei rilievi montonati, di ridotte cerchie moreniche suggerisce che, negli ultimi 225 fig. 12 stratigrafia dei due sondaggi eseguiti nella torbiera di tomalino, con ubicazione dei campioni prelevati per analisi palinologica. stratigraphy of the two cores taken from the tomalino mire, with position of samples for pollen analysis. stratigrafia della sequenza cataglaciale ... stadi di ritiro del ghiacciaio balteo dall'anfiteatro, si sviluppasse un lobo di diffluenza glaciale, indicato nel presente lavoro come lobo di bienca, che, alimentato dal ghiacciaio principale, si insinuava tra i rilievi modellati in roccia. la presenza di tre generazioni di sedimenti glaciolacustri, lacustri e palustri all’interno della depressione di tomalino riflette la successione di tre distinti episodi deposizionali, indicativi di diverse configurazioni del bacino in rapporto all'evoluzione del ghiacciaio: depositi costituenti terrazzi di kame, sedimentati in laghetti di margine glaciale e distribuiti a gradinata sul fianco interno delle morene o dei rilievi montonati (1 in fig. 10); depositi di lago di sbarramento glaciale, sedimentati in un lago più esteso di quello poi colmato dalla torbiera, il cui livello elevato era sostenuto dallo sbarramento degli sfioratori da parte del margine sinistro del ghiacciaio balteo (2 in fig. 10); infine una sequenza di depositi lacustri e palustri, che ha colmato un lago non più alimentato dal ghiacciaio ed il cui livello era controllato esclusivamente dalla morfologia locale (3 in fig. 10). l’analisi pollinica dei sedimenti campionati presso la torbiera di tomalino mette in luce le potenzialità di questo sito per un’analisi paleobotanica dettagliata, grazie a condizioni di sedimentazione che favoriscono la presenza e l’ottima conservazione dei palinomorfi. il confronto con il diagramma pollinico del lago sirio (schneider, 1978) consente di attribuire al campione di sedimento più profondo estratto dalla torbiera di tomalino un’età riferibile alla prima metà dell’interstadiale bølling-allerød del tardoglaciale. in base alla presenza di terrazzi lacustri legati a sbarramento glaciale, sospesi di qualche metro sulla piana, è possibile affermare che condizioni di sedimentazione lacustre erano presenti nell’area almeno dall'inizio del tardoglaciale. i sondaggi svolti nella torbiera di tomalino, che purtroppo non hanno raggiunto la base della sequenza, hanno attraversato tra i 5 e i 4 m di profondità depositi prettamente lacustri, costituiti da sabbie fini e silt di colore biancastro, ricchi di gasteropodi e bivalvi lacustri. segue una sequenza a torbe, alternate a subordinati livelli di gyttja, che si sviluppa ad una profondità compresa tra 4 m ed il piano campagna: questi depositi indicano che il processo di colmamento si è protratto nella parte finale del tardoglaciale attraverso fasi di torbiera. la correlazione su base palinologica dei vari tratti di carota recuperati suggerisce infine l'esistenza di una superficie di discontinuità (fig. 12), di carattere probabilmente erosionale, che incide di oltre 2 metri su una distanza di circa 5 m la successione lacustre e palustre ancora pleistocenica (tardoglaciale); su questa poggia una sequenza di nuovo strettamente palustre (gyttja e torbe) ormai già olocenica (preboreale). si ipotizza che un cambiamento climatico, con diminuzione delle precipitazioni, possa aver determinato nella conca di tomalino il passaggio da ambiente palustre a subaereo, comportando una lacuna durante l' intero dryas recente o parte di esso, a seconda dell'attribuzione dei campioni tom 3-275 cm e tom 3-175 cm rispettivamente alla parte finale dell’interstadiale b-a o al dryas recente. la discontinuità potrebbe essere imputabile all'attività erosiva di un corso d'acqua effimero, che avrebbe inciso e terrazzato la successione palustre, portando alla luce i sottostanti depositi lacustri. il ripristino di condizioni palustri nel preboreale è da collegare ad un bilancio idrologico positivo del bacino, determinato dall'aumento delle precipitazioni e da un ipotetico sbarramento della soglia da parte di prodotti gravitativi. lavori citati baggio p. (1965) caratteri stratigrafici e strutturali del canavese s.s. nella zona di montalto dora. mem. ist. min. geol. un. padova, 25, 1-25. biino g. & compagnoni r. (1989) the canavese zone between the serra d’ivrea and the dora baltea river (western alps). eclogae geol. helv., 82, 413-427. bortolami g., carraro f., friz c., govi m. & sacchi r. (1966) foglio 43 “biella” della carta geologica d’italia alla scala 1:100.000. iiª ed., serv. geol. it., roma. bortolami g., carraro f. & sacchi r. (1967) note illustrative del foglio 43 “biella” della carta geologica d’italia alla scala 1:100.000. iiª ed., serv. geol. it., roma. carraro f. (1992) la zona pedemontana da ivrea ad arona. depositi quaternari. in: dal piaz g. v. (ed.), le alpi dal monte bianco al lago maggiore. soc. geol. it., guide geologiche regionali, 3(a), 186209. bema, milano. carraro f. & petrucci f. (1969) carte géologique de la plaine du piémont 1:400.000. viii congrés inqua, paris. carraro f., medioli f. & petrucci f. (1975) geomorphological study of the morainic amphitheatre of ivrea, northwest italy. bull. r. soc. new zealand, 13, 89-93, wellington. carraro f., lanza r., perotto a. & zanella e. (1991) l’evoluzione morfologica del biellese occidentale durante il pleistocene inferiore e medio, in relazione all’inizio della costruzione dell’anfiteatro morenico d’ivrea. boll. museo reg. sc. nat. torino, 9(1), 99-117. compagnoni r., dal piaz g. v., hunziker j. c., gosso g., lombardo g. & williams p. f. (1977) the sesia-lanzo zone, a slice of continental crust with alpine high pressure-low temperature assemblages in the western italian alps. rend. soc. it. mineralogia e petrologia, 33, 281–334. de beaulieu j. l. & reille m. (1992) the last climatic cycle at la grand pile (vosges, france). a new pollen profile. quaternary science reviews, 11, 431-438. finsinger w., tinner w., van der knaap w. o. & ammann b. (2006) the expansion of hazel (corylus avellana l.) in the southern alps: a key for understanding its early holocene history in europe? quaternary science reviews, 25, 612-631. firbas f. (1954) die synchronisierung der mitteleuropäischen pollendiagramme . danm. geol. unders., 80, 12-21. forno m. g. & lucchesi s. (2000) significato delle diverse facies glaciali nell’evoluzione geologica pleistocenica del settore settentrionale dell’anfiteatro morenico d’ivrea (piemonte). il quaternario, ital ian journal of quaternary sciences, 13(1/2), 47-55. 226 m.g. forno et.al. forno m. g., gianotti f. & grosso f. (2005) il modellamento glaciale dei colli dioritici d’ivrea. atti del convegno a.i.geo montagne e pianure, padova, 99-101. franchi s., mattirolo s., novarese v. & stella a. (1912) foglio 42 “ivrea” della carta geologica d’italia alla scala 1:100.000. iª ed., r. uff. geol. it., roma. franchi s. & stella a. (1933) foglio 43 “biella” della carta geologica d’italia alla scala 1:100.000. iª ed., r. uff. geol. it., roma. gastaldi b. (1869) iconografia di alcuni oggetti di remota antichità rinvenuti in italia. estr. da mem. r. acc. sc. di torino, 2(26), stamperia reale, torino. gianotti f. (1993) ricostruzione dell’evoluzione geologica quaternaria del margine esterno del settore laterale sinistro dell'anfiteatro morenico di ivrea. tesi di laurea inedita, università degli studi di torino, 120 pp. gianotti f. (2007) stratigrafia dell'anfiteatro morenico di ivrea. tesi di dottorato di ricerca inedita, università degli studi di torino, 266 pp. gradstein f. m., ogg j. g., smith a.g., bleeker w. & lourens l. j. (2004) a new geologic time scale with special reference to precambrian and neogene. episodes, 27(2), 83-100. grosso f. (2005) ricostruzione dell’evoluzione geologica pleistocenica dei colli d’ivrea. tesi di laurea inedita, università di torino, 117 pp. guyot a. (1847) note sur la topographie des alpes pennines. bull. soc. sc. nat. de neuchâtel. litt t., schmincke h. u. & kromer b. (2003) environmental response to climatic and volcanic events in central europe during the weichselian lateglacial. quat. sci. rev., 22, 7-32. mangerud j., andersen s. t., berglund b. & donner j. j. (1974) quaternary stratigraphy of norden, a proposal for terminology and classification. boreas, 3, 109-128. martins c. & gastaldi b. (1850) essai sur les terrains superficiels de la vallée du pô, aux environs de turin, comparés a ceux de la plaine suisse. bull. soc. gèol. france, ser. 2, 7, 554-605. moore p. d., webb j. a. & collinson m. e. (1991) pollen analysis. blackwell scientific publications, oxford, 216 pp. orombelli g., ravazzi c. & cita m. b. (2005) osservazioni sul significato dei termini lgm (umg), tardoglaciale e postglaciale in ambito globale, italiano ed alpino. il quaternario, italian journal of quaternary sciences, 18(2), 147-155. penck a. & brückner e. (1909) die alpen im eiszeitalter. 3, 761-768. chr. herm. tauchnitz, leipzig. penck a., brückner e. & du pasquier (1894) le système glaciaire des alpes. guide congr. géol. int., zurich., bull. soc. sc. nat. neuchatel, 22, 86 pp. punt w. & blackmore s. (1976-1995) the northwest european pollen flora. elsevier publishing company, 1-7. ravazzi c. (in stampa) il tardoglaciale: suddivisione stratigrafica, evoluzione sedimentaria e vegetazionale nelle alpi e in pianura padana . acta geologica, studi trentini di scienze naturali. reille m. (1992-1995) pollen et spores d’europe et d’afrique du nord. laboratoire de botanique historique et palynologie, marseille. sacco f. (1927) il glacialismo nella valle d’aosta. min. ll. pp., uff. idrog. po, 66 pp. schneider r. e. (1978) pollenanalytische untersuchungen zur kenntnis der spät-und postglazialen vegetationsgeschichte am südrand der alpen zwischen turin und varese (italien). bot. jahrb. syst. 100(1), 26-109. studer (1844) lehrbuch der physikalischen geographie und geologie. chur und leipzig, bern. van geel b. (1978) a palaeoecological study of holocene peat bog sections in germany and the netherlands, based on the analysis of pollen, spores and macroand microremains of fungi, algae, cormophytes and animals . review of palaeobotany and palynology, 25, 1-120. venturini g. (1995) geology, geochemistry and geochronology of the inner central sesia zone (western alps, italy). mém. géol. lausanne, 25, 148 pp. vescovi e., ravazzi c., tinner w., arpenti e., finsinger w., pini r., valsecchi v., wick l. & ammann b. (2007) interactions between climate and vegetation in the southern alps during the late-glacial period as recorded by lake and mire sediment archives. quaternary science reviews, 26, 16501669. wick l. (1996) late glacial and early holocen palaeoenvironments in brianza, nord-italy. il quaternario, ital ian journal of quaternary sciences, 9(2), 653-660. zingg a., handy m. r., hunziker j. c. & schmid s. m. (1990) tectonometamorphic history of the ivrea zone and its relationship to the crustal evolution of the southern alps. tectonophysic, 182, 169182. 227 ms. ricevuto il 9 ottobre 2007 testo definitivo ricevuto il 11 dicembre 2007 ms. received: october 9, 2007 final text received: december 11, 2007 stratigrafia della sequenza cataglaciale ... imp.palombo biochronology of plio-pleistocene mammalian faunas on the italian peninsula: knowledge, problems and perspectives maria rita palombo dipartimento di scienze della terra, università "la sapienza cnristituto di geologia ambientale e geoingegneria piazzale a. moro, 5 i-00185 roma, italy <mariarita.palombo@uniroma1.it> abstract: palombo m.r., biochronology of plio-pleistocene mammalian faunas on the italian peninsula: knowledge, problems and perspectives. it issn 0394-335, 2004 the biochronological setting thus far proposed for mammalian faunas from the italian peninsula (constructed on the basis of classic criteria: the absence/presence of particular taxa, faunal turnovers, the “evolutionary stage” of taxa belonging to a well-defined phyletic lineage or “typical taxa associations”) provides a highly-detailed categorization of italian assemblages. nevertheless, the more detailed the bioevent sequence becomes, the more difficult it is to establish correlations on a larger scale. multivariate analysis (the recognition of successive, non-overlapping, ecologically-adjusted assemblages of taxa living together in a given space and time) may provide a useful tool for defining faunal complexes having broader biochronological significance. as far as middle pliocenemiddle pleistocene large mammalian faunas from the italian peninsula are concerned, on the basis of our results, we operationally consider the following complexes as possible high-rank biochrons: villafranchian+ early galerian (middle, late pliocene +early pleistocene local faunal assemblages) = “archaic faunas complex ” (afc), and middle, late galerian+early aurelian (middle pleistocene) = “modern faunal complex” (mfc). moreover, the following groups may be regarded as possible lower-rank biochrons: i = early villafranchian; ii = middle villafranchian + late villafranchian; iii = latest villafranchian + early galerian; iv = middle and late galerian; v = early aurelian. the separation between the two main clusters highlights the faunal renewal occurring during the latest early pleistocene, as confirmed by mammalian species turnover and richness trends. the important reorganization of faunal complexes, characterising the transition from the late villafranchian plus early galerian (early pleistocene) to the middle-late galerian plus early aurelian (middle pleistocene) mammalian faunas, can be linked to worsening climate during the last part of the early pleistocene (from about 1.1 to about 0.8 ma). this evidence encourages reconsideration of the definition of galerian land mammal age (lma) previously proposed for italian mammalian faunas. the definition of biochronology (the method most widely-applied to the terrestrial realm in order to relate biological events to the geological time scale), whose application has often been tainted by reference to and inference from biostratigraphy, is briefly reconsidered. riassunto: palombo m.r., biocronologia dei complessi faunistici a grandi mammiferi del plio-pleistocene della penisola italiana: problemi, conoscenze, prospettive. it issn 0394-3356, 2004. l’assetto biocronologico fin ad ora proposto per i complessi a grandi mammiferi dalla penisola italiana si base essenzialmente su bioeventi di comparsa e scomparsa e quindi sui classici criteri di assenza/presenza di definiti taxa, rinnovi faunistici, “grado evolutivo” di taxa appartenenti a ben definite linee filetiche, riconoscimento di “associazioni tipiche”. gli schemi attualmente in uso forniscono una scansione biocronologici dettagliata dei complessi faunistici italiani, tuttavia, quanto maggiore è la quantità di dati di nuovo acquisizione e quanto più dettagliata diviene la sequenza bioeventi riconosciuti, tanto più difficile risulta operare correlazioni a grande scala. le analisi multivariate (finalizzate alla definizione di “gruppi” di faune locali tra loro ben discriminabili, ciascuno dei quali costituente un insieme di taxa presumibilmente vissuti in uno stesso intervallo temporale in definite aree geografiche, coerente dal punto di vista ecologico) possono fornire un mezzo utile di indagine per una prima definizione di complessi faunistici che abbiano una più ampia valenza biocronologica. i risultati ottenuti per complessi faunistici a grandi mammiferi della penisola italiana dal pliocene medio al pleistocene medio, con analisi di somiglianza e di ordinamento dei beventi, suggeriscono di considerare quali biocroni di più alto rango due complessi faunistici: il complesso “ villafranchiano + galeriano inferiore” (local faunal assemblages, lfas, del pliocene medio e superiore e del pleistocene inferiore), qui denominato “complesso faunistico arcaico” (afc), e il complesso “galerian medio e superiore + aurelian inferiore” (lfas del pleistocene medio), qui denominato “complesso faunistico moderno” (mfc). inoltre, possono essere considerati quali possibili biocroni di rango inferiore i seguenti gruppi: i = villafranchiano inferiore; ii = villafranchiano medio + villafranchiano superiore; iii = tardo villafranchiano superiore + galeriano inferiore; iv = galeriano medio e superiore; v = aureliano inferiore. la separazione fra i due gruppi principali evidenzia il profondo rinnovamento faunistico che si realizza alla fine del pleistocene inferiore. la riorganizzazione dei complessi a grandi mammiferi, che caratterizza la transizione tra il complesso che riunisce le lfas del tardo villafranchiano e del galeriano inferiore (pleistocene inferiore) e quello delle lfas del galeriano medio, superiore e dell’aureliano inferiore (pleistocene medio), può essere correlata con il deterioramento climatico del tardo pleistocene inferiore (da circa 1,1 a circa 0,8 ma). su queste basi, sembrerebbe, quindi, auspicabile una ridefinizione dell’età a mammiferi (land mammal age, lma) ” galeriano”, come a suo tempo proposta per le faune a mammiferi della penisola italiana. vengono anche brevemente discussi la definizione di biocronologia ed i suoi criteri di applicazione. keywords: biochronology, pliocene, pleistocene, large mammals, italy. parole chiave: biocronologia, pliocene, pleistocene, grandi mammiferi, italia. il quaternario italian journal of quaternary sciences 17(2/2), 2004, 565-582 566 m.r. palombo 1. foreword as claimed by lindsay (2003), chronostratigraphy (the method generally applied to the oceanographicmarine realm) and biochronology (that most commonly applied to the terrestrial realm), are the prime conceptual methods for relating biological events to the geological time scale. nevertheless, to date, the organisation of geological time on the basis of evidence supplied by continental mammal faunas has continued to be a field plagued by interpretative and semantic confusion. the divergence of opinions on biostratigraphic/biochronological matters may often be attributed to interference between operational (based on stratigraphic records like biostratigraphy) and theoretical (based on bioevents linked to taxa evolution and palaeocommunity transformation biochronology) methodological approaches (see e.g. tedford, 1970; mein 1975, 1990, 1998; woodburne, 1977, 1987, 1996; berggren and van couvering, 1978; guerin, 1982, 1990; de giuli et al., 1983; daams & freudenthal, 1981; flynn et al., 1984; lindsay, 1985, 1997, 2001, 2003; archibald et al., 1987; emry et al., 1987; krishtralka et al., 1987; lindsay & tedford, 1990; pickford, 1990; fernandez-lopez, 1991; brujin et al., 1992; lister, 1992; lucas, 1992; salvador, 1994; berggren et al., 1995a, 1995b; prothero, 1995; opdyke et al., 1997; sen, 1997; van dam, 1997, 2001, 2003; daams et al., 1998; fejfar et al., 1998; walsh, 1998; agusti et al., 2001; azanza et al., 2002; koufos, 2003; ravazzi, 2003 etc). moreover, even if biochronology is a fundamental tool in correlating terrestrial deposits, “biochronology has never been discussed in any stratigraphic code because of that loose and ambiguous application” (lindsay, 2003 p.216). however, it is worth noting that a biochronological unit is a time span defined by palaeobiological events, while a biostratigraphic unit is a body of rock strata defined by its fossil content (stratigraphic datum) (schoch, 1989; salvador, 1994). indeed, discontinuity in the continental sedimentary record, the rarity of deposits formed in a regime of virtually continuous sedimentation, the anisotropy of palaeoenvironmental conditions and taphonomic and sampling biases are responsible for the fact that the stratigraphic order of the highest and lowest occurrences (stratigraphic datum) of taxa remains within a given geographical area does not necessarily reflect the temporal order of their actual first/last appearances (palaeobiological events) in time. therefore, as far as large continental mammals are concerned, given that: 1) the actual occurrence in time of a palaeobiological entity (both in general or in a given geographical area) cannot be unquestionably established by its fossil evidence; 2) the relative or absolute deposition dates for rock-bodies in which the first/oldest and last/youngest local appearances of fossil remains (lowest and highest stratigraphic records) are documented, respectively correspond only to the “ante quem” or “post quem” time of actual origination and extinction bioevents; 3) boundaries (specific surfaces within a sequence of rock strata selected as the standard for defining and recognising biostratigraphic units, salvador, 1994) are not indicative “because of the impossibility of defining them with precision” (gliozzi et al., 1997, p.369) and “biozones” ( “bodies of rock strata that are defined or characterised on the basis of their contained fossils”, salvador, 1994, pag. 53) cannot be defined, even if “biochrons” have previously been regarded as similar to “concurrent range” or “assemblage” zones (gliozzi et al., 1997). ultimately, biochronology can be defined as “ the organization of geologic time according to the irreversible process of organic evolution” (lindsay, 2003). “biochrons” represent lapses of time during which faunas demonstrate clear taxonomic homogeneity (see also alberdi et al., 1997); from an operational point of view, they might be considered as “blocks of coordinated stasis” (brett et al., 1996) during which no turnover is expected. faunal complexes belonging to biochrons may be regarded as nonoverlapping and " ecologically adjusted groups of animals with specific geographic limits and chronologic range" (tedford, 1970, pag. 602). nonetheless, if on the one hand first/last appearance bioevents (palaeobiological events on which biochronology is based) have been the principal basis for establishing the chronological setting of continental mammalian faunas, on the other hand these bioevents are documented by the lowest/highest occurrences of fossil remains in fossiliferous levels of various continental stratigraphic successions (stratigraphic datum, the basis of biostratigraphy). indeed, mammalian paleontostratigraphy (sensu walsh, 1998) is actually founded on fossil records available in continental rocks, and new discoveries can substantially alter pre-established biochronological schemes. the biochronological settings thus far proposed for mammal faunas on the italian peninsula have been based on the faunal complexes named faunal units (fus), further classified in a number of land mammal ages (lmas). the definition of fus derives from bioevents, such as the first appearance of one or more taxa, and/or the possible disappearance of others on the evolutionary stage, displayed by taxa belonging to a well-established phyletic lineage, or on typical taxa associations. this substantially agrees with lindsay’s definition (2003) for lmas, defined as relatively short intervals of geologic time that can be recognized and distinguished from earlier and later units (in a given region or province) by a characterising assemblage of mammals. since initial introduction of these biochrons (azzaroli, 1977), italian palaeontologists have proposed some new fus and/or new mammal ages (mas) or revised others (see e.g. torre, 1987; sala et al., 1992; caloi & palombo, 1996; gliozzi et al., 1997; petronio & sardella, 1999; palombo et al, 2004). the introduction of such new biochrons often depends on acquiring new data and discovering new fossiliferous assemblages that enable better discrimination of the temporal succession of bioevents by means of the highest and lowest occurrences in local sedimentary sequences. indeed, the complex physiography of the italian peninsula, the geographical and ecological barriers represented by the alpine and apennine chains, together with its remarkable latitudinal rather than longitudinal extension, as well as the great influence of the mediterranean sea on climatic conditions, supply a unique opportunity to analyse the influence of various factors influencing the structure of mammal assemblages in the course of time. it is thus evident that the current biochronological scheme provides very detailed resolution for italian assemblages, but is less useful for comparing and correlating other european mammal faunas. the aim of this paper is: 1) to provide a concise picture of our knowledge of biochronology of italian large mammals; 2) to update previous biochronological schemes in light of the latest discoveries; 3) to define adjusted homogeneous groups of taxa having biochronological significance using multivariate analyses; 4) to compare these “groups” with previously-established biochrons. 2. biochronological framework: an overview to define the chronological framework of italian mammal faunas, a number of schemes have been proposed by several authors (for instance ambrosetti et al., 1972; azzaroli, 1977, 1982, 1983, 1991; de giuli et al, 1983; torre, 1987; azzaroli et al., 1988; torre et al., 1992, 1996; caloi & palombo, 1990, 1996; gliozzi et al., 1997; petronio & sardella, 1999). initially, azzaroli (1977) proposed a subdivision of six fus for mammal faunas belonging to the vil lafranchian lma. subsequently, the discovery of new faunas, adding to knowledge of faunal renewal phases and the transitional character of some local assemblages (lfa), led to the introduction of new faunal units and/or new proposed mammal ages. in 1997, gliozzi et al. suggested a biochronological scheme for middle pliocene to late pleistocene italian continental faunas (large and small mammals, fresh-water molluscs and brackish ostracods) that has recently been widely utilised by italian palaeontologists. three lmas were defined for the time span between the middle pliocene and late pleistocene: villafranchian (late middle pliocene to early early pleistocene), galerian (late early pleistocene to early middle pleistocene), and aurelian (late middle pleistocene to late pleistocene), respectively including eight (triversa, montopoli, saint vallier, costa san giacomo, olivola, tasso, farneta, pirro), four (colle curti, slivia, isernia, fontana ranuccio) and more than two fus (torre in pietra, vitinia and non-defined). moreover, the transitional character of some local faunas was pointed out (see discussion in gliozzi et al., 1997). subsequently, petronio & sardella (1999) proposed ponte galeria local fauna as representative of a distinct middle galerian fu, transitional to isernia fu. 2.1 the villafranchian land mammal age (lma) the villafranchian was originally defined as an age/stage, since pareto (1865) designated the lower boundary of the villafranchian stratotype in villafranca d’asti (italy) at the bottom of the vertebrate bearing fluvio-lacustrine sequence overlying pliocene marine beds. subsequently, the “villafranchian” question has been extensively debated (see carraro, 1996 for a review and discussion). however, subsequent authors considered the villafranchian as a biochron/biochronozone defined by dispersal events, and not as a geochron/geochronozone, formally defined by golden spikes. for example, heintz (1970) considered the villafranchian as a biochron including the middle and late pliocene. this french scientist divided his 567biochronology of the ... villafranchian into four biochrons (early, middle, late and latest villafranchian) on the basis of taxa belonging to phyletic lines of cervid taxa. on the other hand, azzaroli (1977) extended the villafranchian to the earlymiddle pleistocene boundary. more recently, gliozzi et al. (1997) considered the villafranchian ma a biochron beginning with faunal turnover marked by the appearance of newcomers such as “pseudodama”(= axis according to di stefano & petronio, 2003), leptobos stenometopon, and stephanorhinus elatus (=s. jeanvireti), and ending before the jaramillo subchron. 2.1.1 early and middlevillafranchian fus based on faunal renewals, the villafranchian lma was divided into early, middle and late sub-biochrons (azzaroli et al., 1988; gliozzi et al., 1997). the early villafranchian is represented by the triversa fu, established on a number of local faunas from the villafranca d’asti area (piedmont) and from central italy (e.g. lower and upper valdarno, arcille, spoleto). palaeomagnetic analysis at fornace r.d.b. (villafranca d’asti) ascribes the sequence to gauss chron (lindsay et al., 1980). nevertheless, according to lindsay et al. (1995), the intervals of reversed magnetic polarity separated by a normal magnetozone previously identified at fornace r.d.b. cannot be correlated with the mammoth or khaena episodes, but with the late gilbert chron. nevertheless, this hypothesis disagrees with geological palynological evidence (albianelli et al., 1995,1997; bertini & roion, 1997) as well as with the paleomagnetic calibration (torre et al. 1996) carried out on a long sedimentary sequence containing typical early villafranchian fossil assemblages appearing at the santa barbara quarry (lignitic lacustrine silty clays and sands, meleto clays from the castelnuovo dei sabbioni sequence, upper valdarno). the results attest a long normal polarity interval interrupted a few meters above the fossiliferous lignite level by a reversed polarity interval, respectively attributable to the late gauss age and the short kaena event. consequently, the beginning of the early villafranchian can be dated at about 3.3-3.2 ma. b.p. the triversa faunal complex (table 1), although renewed with respect to ruscinian faunas, maintained quite a damp forest character: pachyderms and smallmiddle sized ruscinian perrissodactyla and artiodactyla, mainly browsers or mixed-feeders inhabiting dense or clear woodland, were still present, along with arboreal omnivores such as ursus minimus. on the other hand, the disappearances of primates and carnivores inhabiting humid and forest environments, as well as the appearance of some taxa dwelling in more or less open environments, such as leptobos stenometopon, testified to moderate structural renewal, which can be correlated with the climatic cooling taking place at about 3.2/3.1 (palombo, 2004). the following montopoli fu is based on the rich fauna from a site near montopoli (lower valdarno), found in a fossiliferous level at the top of a marine sequence, calibrated with the gauss/matuyama transition (lindsay et al., 1980). the montopoli local faunal assemblage (lfa), (dated to about 2.6 ma), as well as the montopoli f. u., have long been considered early villafranchian in age. nevertheless, the noticeable faunal turnover characterising the transition from the 568 m.r. palombo table 1 biochronology of selected large mammals of the italian peninsula, dating from the late pliocene to the late pleistocene. distribuzione cronologica dei principali taxa di grandi mammiferi della penisola italiana dal pliocene medio al pleistocene superiore 569 triversa f.u to the montopoli f.u, delineated by the cooling event taking place about 2.6/2.5 ma, may be regarded as a bioevent marking the beginning of the middle villafranchian (alberdi et al., 1998, caloi & palombo 1999, palombo 1995, 2004, palombo et al., 2003). the reorganization of "palaeocommunities” from the early to middle vil lafranchian (the so-called “elephant-equus event” sensu lindsay et al., 1980), corresponds to a true turnover and can be regarded as the starting point of a dispersal phase. in the montopoli fu, forest taxa greatly diminished and several new herbivores appeared, including large-sized ones and pachyderms, such as a primitive mammuthus (see palombo & ferretti, 2005 for a discussion). moreover, the occurrence of the large equus livenzovensis was consistent with the increasing extension of grassy areas, characterised by herbaceous vegetation of the steppe type, suggesting arid conditions (suc et al. 1995; torre et al. 2001; palombo, 2004). italian faunal assemblages belonging to the middle villafranchian (“saint vallier” fu) are scanty, with weak stratigraphic constraints. for example, the colle pardo lfa (anagni basin, cassoli & segre naldini, 2000), despite the scarcity of faunal remains, has been considered intermediate in age between the montopoli and costa san giacomo complexes by several authors (caloi & palombo, 1996; gliozzi et al., 1997). according to the faunal list, only the occurrence of a caprinae (possibly similar to hemitragus orientalis recorded at the late pliocene bulgarian site of slivnitsa, cregutbonnoeur & spassov, 2003) might exclude attribution to an older faunal complex (?montopoli fu). consequently, using only large mammals, a faunal complex characterising the “saint vallier” fu cannot be adequately defined in italy, unless running through taxa are considered. in the following costa san giacomo fu, a dog, similar to the late villafranchian species canis etruscus, and sus strozzii were first recorded (costa san giacomo lfa, anagni basin, biddittu et al. 1979). moreover, typical middle villafranchian taxa, such as “pseudodama” lyra (axis lyra, according to di stefano & petronio, 2003), eucladoceros tegulensis, leptobos merlai, gazella borbonica and gazellospira torticornis were still present, along with the ruscinianmiddle villafranchian taxon anancus arvernensis1. the diffusion of the genus canis in europe, the so called “wolf event” (sensu azzaroli, 1983) [canis sp. is also recorded at chilhac (monguillon-douillet, 2000), a site dating more than 1.9 ma (bœuf, 1997)], possibly a more gradual phenomenon than previously supposed, crossed the plio-pleistocene boundary (sensu aguirre & pasini, 1985)2 and culminated at the beginning of the pleistocene, at the time of the tasso fu. 2.1.2 the beginning of the late villafranchian the faunal renewal taking place at the end of the late pliocene involved both carnivore and herbivore guilds, which clearly became more diversified. most pliocene species disappeared, particularly among herbivores, and new carnivores and herbivores progressively spread across the italian peninsula (table 1). thus this renewal may be regarded as an increasing dispersal phase rather than an actual turnover (palombo, 2004). according to azzaroli (1977), three fus (olivola, tasso and farneta) belong to the late villafranchian, at that t ime considered to coincide with the early pleistocene. subsequently, a fourth fu, pirro, more advanced than farneta, was added (caloi & palombo, 1996), and the end of the late villafranchian was later brought forward, before the jaramillo subcrhon (gliozzi et al., 1997). the lfa from olivola (val di magra) is characterised by the lowest occurrence of pachicrocuta brevirostris, panthera gombazsoegensis, ”pseudodama” nestii (axis nestii according to di stefano & petronio, 2003) and eucladoceros dicranios; scanty remains of procamptoceras brivatense were also found, whereas canis etruscus was represented by several individuals. two late villafranchian lfas, matassino and casa frata, were retrieved from the upper valdarno, from fossiliferous levels cropping out along the montevarchi sequence (borselli et al., 1980; de giuli & masini, 1987). matassino and casa frata lfas were ascribed respectively to olivola and tasso fus (azzaroli et al., 1988; but see gliozzi et al, 1997), due the occurrence of new taxa such as lycaon falconeri (see martinez navarro & rook, 2003, for a discussion) at casa frata, equus stehlini,? lepobos vallisarni and praeovibos sp. moreover, matassino and casa frata lfas have been respectively calibrated with the β event and with the top of the olduvai subchron (torre et al., 1996). recently, a new faunal assemblage was collected at poggio rosso, in sediments of the second deposition phase called the montevarchi succession (argille del torrente ascione, albianelli et al., 1995; mazza et al. 2004), just below the plio-pleistocene boundary, but about 30 m above the matassino lfa (napoleone et al., 2001; napoleone & azzaroli, 2002; napoleone et al., 2003). the taxonomical composition of the poggio rosso lfa is “intermediate” between that of olivola and tasso fus due to, for example, the occurrence of both canis arnensis and chasmaporthetes lunensis (mazzini et al., 2000; mazza et al., 2004). accordingly, on the basis of magnetostratigraphic calibration of the matassino and poggio rosso localities, the late villafranchian theoretically started during the latest pliocene, undoubtedly before the plio-pleistocene boundary. according to napoleone biochronology of the ... 1 it is worth noting that zanchetta & mazza (1996) proposed an early pleistocene age for a fragmentary skeleton of anancus from monte castello (lower valdarno); in any case, this datum requires confirmation. 2 the profuse changes in flora and fauna during this event have prompted several authors (alberdi et al 1997; suc et al. 1997; morrison & kukla, 1998 and references therein) to propose placing the plio-pleistocene boundary here. [we have to note that, as pointed out by kolfschoten & gibbard (1998, p. 16) “the fact that the vrica boundary was only notified by the moscow igc in 1984, should not be a reason for not reconsidering the boundary position”. thus, the lowering of the pliocene/pleistocene boundary to around the gauss/ matuyama palaeomagnetic reversal (mis 104, approximately 2.6 ma) is being debated by several authors, as well as the inqua commission of stratigraphy. in this paper, we provisionally maintain the plio-pleistocene boundary proposed by aguirre & pasini (1985), even if the global change occurring at mis 104 should be considered a more appropriate boundary. 570 et al. (2003, p. 308), faunas belonging to the olivola fu could be “inferred as pre-olduvaian, not younger than 2.0 ma.” moreover, it is worth noting that the structure of faunal complexes ascribed to olivola and tasso fus are not very dissimilar, the second differing essentially in the appearance of lycaon falconeri, leptobos vallisarni and equus stehlini, whereas gallogoral meneghinii and gazellospira torticornis were not recorded. moreover, the hippopotamus antiquus from valdarno, whose appearance was previously considered as belonging on the tasso fu, was probably retrieved from fossiliferous levels younger than those of the montervarchi succession (napoleone et al., 2003). accordingly, the olivola and tasso faunal complexes seem to express the same progressive faunal renewal culminating with the “tasso” faunal complex. consequently, the hypothesis that the olivola and tasso faunal complexes may represent a single fu cannot be definitively ruled out. 2.2 the end of the villafranchian lma and the dawn of the galerian lma during the following early pleistocene (“postgalerian” sensu caloi & palombo, 1996), most of the typical villafranchian taxa disappeared or became rare, and some new species, phylogenetically linked to taxa characterising early middle pleistocene faunas, progressively appeared. on the whole, during the early pleistocene (late villafranchian pro parte and early galerian), herbivores inhabiting open environments became more abundant, and forest dwellers noticeably reduced their diversity (table 1). this is consistent with the early pleistocene climatic trend, characterised by a progressive decrease in mean temperature, although climatic oscillations were not accentuated. moreover, several data suggest the spread of grassland/steppe areas (suc et al., 1995; bertini, 2000 and references therein). equus stenonis was replaced by the slenderlimbed equus altidens and by the heavier, larger equid already ascribed to the problematic group of equus bressanus/equus suessenbornensis. among pachyderms, rhinoceroses, perhaps linked to stephanorhinus hundsheimensis, seem to have been ecological substitutes for stephanorhinus etruscus. moreover, ovibovines, megalovis sp., and bison-like bovines appeared locally (bison (eobison) degiuli and perhaps another taxon (?bison sp.) may be linked to the more advanced middle galerian bison schoetensacki). nevertheless, forest areas were still rather abundant and, little by little, woodlands spread during more temperate and humid climatic phases. woodlands were mainly inhabited by cervids belonging to the small-medium sized species of the “pseudodama” genus and by the larger mixed-feeder “praemegaceros” obscurus3, which replaced the browser eucladoceros (table 1). furthermore, a number of data seem to confirm the transitional character of typical late villafranchian and galerian mammal assemblages (azzaroli et al., 1988, caloi & palombo, 1996; palombo, 2004 and references therein). according to gliozzi et al. (1997), the appearance of “praemegaceros” verticornis is the bioevent conventionally marking the beginning of the galerian lma (colle curti fu). the lowest species occurrences of this taxon in italy is in the colle curti lfa, calibrated with the jaramillo subchron (coltorti et al., 1998). however, colle curti lfa shares several taxa (carnivores, rhinoceros, hippopotamuses) with older lfas belonging to the pirro nord fu (table 1). thus, despite the appearance of “praemegaceros” verticornis as well as the innovative characteristics demonstrated by arvicolids from colle curti lfas (coltorti et al., 1998), early galerian lfas seem more closely related to the latest villafranchian faunas than to ensuing true galerian ones (palombo et al., 2003; palombo, 2004; palombo & valli, 2004). the end of the early pleistocene (end of the villafranchian event sensu azzaroli et al., 1988) actually represented the most significant period of striking faunal renewal on the italian peninsula, giving rise to remarkable palaeocommunity reorganization involving faunal migrations and extinction events (see alberdi et al. 1997, gliozzi et al. 1997; palombo, 2004; palombo et al., in press). 2.2.1 middle and late galerian faunal complexes the middle galerian (early middle pleistocene) came into being during great climatic cooling (stages 24 and 22 of the marine oxygen isotopic signal, mis) characterising the beginning of the middle pleistocene (sensu cita & castradori, 1995)4. faunal renewal derives from two distinct trends: 1) the progressive reduction in richness characterising late early pleistocene faunas (from farneta to colle curti fus), 2) the subsequent dispersal and progressive diffusion in italy of taxa from eastern and central europe, leading to an important and relatively rapid increase in diversity (slivia fu) (palombo, 2004). m.r. palombo 3 the name megaceroides (type species “cervus" algericus lydekker 1890) was proposed by joleaud in 1914, as a cervus subgenus for a fragmentary maxillary; subsequently, arambourg (1932, 1938) ascribed a skull from the late pleistocene of algeria and morocco to this species. similarities in skull features between specimens from the magreb and the megacerines (= megacerini tribus, sensu viret 1961) from europe, first pointed out by azzaroli (1952), have subsequently been widely debated (see e.g. hadjoudis, 1990; azzaroli & mazza, 1992; croitor, 2004; abbazzi, in prep.). all in all, it seems more correct to maintain the name megaceroides only for the north african species. nevertheless, the problem concerning the nomenclature of the genera referring to the tribe megacerini is still unresolved. assuming that the species ascribed to the so-called “verticornis” group and the “giganteus” group belong to two distinct lineages, what is the correct generic name among those used thus far for the giant deer belonging to the “verticornis” group and the “giganteus” group belong to two distinct lineages, what is the correct generic name among those used thus far for the giant deer belonging to the “verticornis” group? the name “praemegaceros”, though not formally correct (see e.g. azzaroli, 1979; caloi & palombo, 1996), has been frequently employed, whereas other names, such as “ortogonoceros” or “psekupsoceros”, have not been de facto utilised in more recent times. for this reason, to avoid additional confusion, we provisionally use the generic name “praemegaceros” for these giant european deer. 4 it is worth noting that the earlylate pleistocene boundary is currently placed informally at the matuyama/brunhes palaeomagnetic inversion (richmond 1996), but cita & castradori (1995) proposed a lower horizon at marine isotope stage (mis) 25. in the course of time (table 1), the appearances of several pachyderms (elephas (palaeoloxodon) antiquus, mammuthus trogontherii, stephanorhinus kirchbergensis, stephanorhinus hemitoechus), cervids (small-sized capreolus capreolus, medium-sized cervus elaphus and dama clactoniana, large-sized megaloceros savini and “praemegaceros” solilhacus) and large and middle-sized bovines (hemibos galerianus see martinez navarro & palombo 2004, for a discussion-, bos primigenius, ovis ammon antiqua and hemitragus bonali), brought about a major change in herbivore guilds. among carnivores, crocuta crocuta was surely recorded for the first time in the ponte galeria 2 lfa (sardella, 2004), whereas the lowest occurrence of some other large carnivores (active hunters that were both flesh-eaters and scavengers, such as ursus deningeri, panthera pardus, panthera leo fossilis, and “hyaena prisca”) was even later, in lfas belonging to the isernia fu. according to gliozzi et al. (1997), two fus, slivia and isernia, belong to this mammal sublma. subsequently, petronio & sardella (1999) proposed a new fu, ponte galeria fu, based on specimens found in hst deposits of the pg2 sedimentary sequence cropping out along the latium coast (= ponte galeria 2, see milli et al., 2004). the above-mentioned authors believed the age and taxonomical composition of the ponte galeria fu to be intermediate between the slivia and isernia lfas. if the three middle galerian fus were valid, they would differ essentially in the persistence of mimomys savini , pachycrocuta brevirostris and panthera gombaszoegensis (slivia fu), the exclusive occurrence of hemibos galerianus (ponte galeria fu) and the appearance of bos primigenius (isernia fu). nevertheless, it is possible that slivia and ponte galeria 2 lfas belong to the same fu due to the uncertain identification of some herbivores from slivia local fauna, as well as limited knowledge of the carnivores and micromammals from the ponte galeria 2 lfa (palombo, 2004). moreover, an arvicolid similar to mimomys savini has recently been found in pagliare di sassa lfa (l’aquila, abruzzo) (palombo and di canzio, unpublished data) where “praemegaceros” verticornis, megaloceros savini (as in ponte galeria) and dama cf d. clactoniana were also recorded (palombo et al., 2001). as far as the transition from the middle (isernia fu) to the late galerian (fontana ranuccio fu) is concerned, we can place it around 500 ka, in view of the age proposed for the lfas ascribed to the isernia fu (notarchirico, estimated age about 600 ka, lefèvre & raynal 1999, lefèvre et al. 1999; isernia, estimated age about 600 ka; coltorti et al., 2000), and the possible age of the fontana ranuccio lfa (estimated age about 458 ka, biddittu et al. 1979). during the late middle galerian (fontana ranuccio fu), “villafranchian” taxa had not been recorded and the number of very large herbivores diminished (table 1), leaving the occurrence of “galerian” equids and megacerines in doubt. moreover, the specialised and slightly larger h. antiquus was replaced by hippopotamus amphibius and, among carnivores, ursus arctos appeared, as well as felis silvestris silvestris (table 1). 2.3 early aurelian faunal complexes gliozzi et al. (1997) proposed the aurelian lma (divided into early, middle and late aurelian) for late middle (from 10 to 6 mis) and late pleistocene mammal faunas (from 5 to 1 mis). the authors separated the early and middle aurelian on the basis of faunal differences between torre in pietra and vitinia fus (caloi & palombo 1990, 1996), whereas no characteristic fus have been designated for the late aurelian. the vitinia fu was considered dissimilar to the torre in pietra fu, essentially due to the abundance of a primitive fallow deer (dama dama tiberina) and the appearance of cervus elaphus, with features similar to those of modern forms of red deer and equus hydruntinus (caloi & palombo, 1996; gliozzi et al. 1997). both these fus have been defined on the basis of palaentological and stratigraphic data collected in the campagna romana area (cfr. caloi et al., 1998 and references therein). nevertheless, the structure and taxonomical composition of torre in pietra and vitinia faunal complexes are similar (palombo & mussi, 2001; palombo 2004), so the division into two fus seems to be based on weak palaeontological evidence. moreover, it is worth noting that the lfa of sedia del diavolo (rome) referred to the vitinia fu, since the abundance of dama dama “tiberina” remains were found in alluvial deposits overlaying “tufo lionato” (dated 355 ka by karner et al., 2001), where equus hydruntinus was also found (caloi & palombo, 1995). caloi et al. (1998) correlated the sedia del diavolo deposits containing dama dama “tiberina” remains with the vitinia formation (mis 7). nonetheless, on top of the deposits previously correlated with mis 7, an ash flow deposit, dated 285 ± 1 ka by karner et al. (2001), has been recognised (marra & rosa, 1995). in conformity with this new chronological data, the deposition of the fluvio-lacustrine sediments overlaying “tufo lionato” at sedia del diavolo occurred approximately between 355 and 285 ka (palombo et al., 2004). accordingly, dama dama ”tiberina” and equus hydruntinus were already present during mis 9, and thus the vitinia fu cannot be considered a valid biochron. the lfas previously ascribed to the torre in pietra and vitinia fus must be included in a single fu (named torre in pietra fu for reasons of priority). several bioevents characterised the beginning of this fu, as well as the beginning of the aurelian lma (subdivided into early and late aurelian): canis lupus and felis silvestris silvestris first appeared, as well as ursus spelaeus, substituting u. deningeri, and e. hydruntinus, megaloceros giganteus, dama dama “tiberina”, and bubalus (palombo, unpublished data), whereas ovis ammon antiqua and bison schoetensacki were not yet recorded (table 1). 3. in search of new biochronological assessments in recent years, several multivariate approaches have been developed in an attempt to supplement the similarity and association concepts. actually, multivariate analysis, if not conclusive in itself, can be a useful tool in initially defining faunal complexes and could be used to limit the biochronological framework based on classic methodologies (azanza et al., 1997, 1999; 571biochronology of the ... palombo et al., 2003 and references therein). in order to quantify the similarities and biochronological relationships among selected local mammal assemblages and establish a faunal succession, we have applied two different kinds of multivariate analysis: "appearance event ordination" (aeo; alroy, 1994) and similarity cluster analysis (see e.g. hazel, 1970). the former method uses the various relationships between the first and last appearances of taxa (actually the highest and lowest occurrences of their fossil remains in local faunas) as basic data. chronological information is inferred by detecting which taxa appear before the last occurrence of another one. the "best" solution in this procedure involving correspondence analysis is to search for a parsimonious arrangement of events that minimises the overall number of implied first and last appearance relationships. "appearance event ordination" is based on parsimony, as only relationships between first and last “appearances” in several lfas are taken into account, while occurrences of common taxa are not considered (see palombo et al., 2003, for a discussion). in the second method, the presence of common taxa provides basic data for evaluating similarities between local faunas grouped according to their taxonomic homogeneity. conversely, the absence of a species, highly dependent on taphonomic and random factors, supplies no precise information. we evaluated similarities on the basis of the jaccard binary coefficient and cluster analysis performed using the upgma method, as according to this method each member of a cluster has equal weight at all levels of clustering (cfr. hazel 1970; shi 1993; azanza et al., 1997,1999; palombo et al., 2003 and references therein) (ntsyspc program, version 2.0, rohlf, 1998). clusters do not necessarily supply chronological information or necessarily imply recognition of successive, non-overlapping, ecologically-adjusted assemblages of taxa living together in a given space and time. for this reason, the q-mode dendrogram, particularly suitable for biochronologically-oriented studies (cfr. hazel 1970), was preferred. 3.1 “appearance event ordination" calibration of the appearance event sequence (fig. 1) introduces a temporal distortion that becomes greater as available dating diminishes, as in the case of italian faunas. the distortion between the actual and estimated ages of localities indicates a contraction in time for ruscinian and early+middle villafranchian lfas (from 4.5 to 2.5 ma) and quite good correspondence for late villafranchian and galerian (2.0 to 0.400 ma), whereas early aurelian lfas are dated more recently (between 0.400 and 0 ma) (see azanza et al., 2004). after obtaining chronological relationships for italian mammal faunas, two groups can be identified, corresponding to the pliocene + early pleistocene and to the middle pleistocene lfa (fig. 1). within the first group, early villafranchian lfas appear equivalent in age, whereas the middle villafranchian are distributed in a span of less than 1 ma, in accordance with the faunal renewal characterising this faunal complex. colle pardo lfa is shown to be older than the montopoli lfa, probably due to the absence of mammuthus and equus in the former locality. the distribution of lfas ascribed to olivola and tasso fus confirms the homogeneity within each faunal complex, as well as the intermediate evolutionary stage of the poggio rosso lfa. matassino cannot be clearly positioned, given the scarcity of biochronicallyrelevant taxa. successive lfas are arranged according to the progressive renewal characterising the late early pleistocene. within the group including middle pleistocene lfas, slivia and ponte galeria lfas appear to be the most archaic among middle galerian faunas, whereas fontana ranuccio and visogliano (late galerian) undergo the greatest change, along with valdemino, which actually belongs to the middle galerian, but where some taxa (such as panthera pardus and bos primigenius) were recorded for the first time on the italian peninsula (nocchi & sala, 1997). the reduced biochronological significance of some late middle pleistocene (early aurelian) lfas makes it impossible to define their relationships. we can note that paglicci (external beds) and torrente conca lfas set a part, probably because of the occurrence of rupicapra and capra ibex (the latter only in the paglicci lfa). 3.2 similarities between lfas among large mammal faunas from the middle pliocene to the late middle pleistocene, 74 lfas were selected for a new similarity analysis, improving and updating those already performed on italian mammal lfas (palombo et al., 2003; palombo 2004; palombo & valli, in press). the faunal list for each locality was critically reviewed, including up-to-date records and personal observations. since italian fus are in some cases based on the appearance of subspecies, these taxa were also included in the data matrix. the q-mode dendrogram (fig. 2) separates local faunal assemblages (lfas) into two main groups and reveals a major separation between pliocene-early pleistocene (cluster a = villafranchian lma and early galerian, colle curti fu) and middle pleistocene lfas (cluster b = middle, late galerian slivia, isernia and fontana ranuccio fus-, and early aurelian, torre in pietra fu), the latter group having a rather higher similarity coefficient. the major separation between a and b clusters underlines the faunal reorganisation which occurred during the climatic crisis taking place at the early to middle pleistocene transition (sensu cita & castradori, 1995). this renewal phase seems to have been more important than those marking transitions from the early to the middle villafranchian (the so-called “elephantequus event” sensu lindsay et al., 1980) and from the middle to the late villafranchian (the so-called “wolf event” sensu azzaroli, 1983). a and b clusters share a low number of taxa; consequently, we can hypothesize that each one makes up part of “an ecologically adjusted group of animals with specific geographic limits and chronological range” (tedford 1970: 602). alberdi et al. (1997) have informally named these kinds of aggregates “superages”, considering them equivalent to “chronofauna” (sensu tedford 1970, emry et al., 1987). we informally name these groups “archaic faunal complex” (afc = cluster a) and “modern faunal complex” (mfc = cluster b). 572 m.r. palombo 573biochronology of the ... fi g. 1 c hr on ol og ic al r el at io ns hi p s fo r ita lia n m am m al fa un as o rd er ed a cc or d in g to a “ p ar si m on yb as ed a p p ro ac h” (a p p ea ra nc e ev en t or d in at io n, a lro y 19 92 , 1 99 4) . o rd in am en to b io cr on ol og ic o d el le fa un e lo ca li d el la p en is ol a ita lia na d al p lio ce ne m ed io a l p le is to ce ne m ed io o tt en ut o ut ili zz an d o il m et od o “a p p ea ra nc e ev en t o rd in at io n” d i a lro y (1 99 2, 1 99 4) . both clusters are further divided into subclusters; within a, a1 includes early villafranchian (triversa fu) lfas as well as the ruscinian val di pugna lfa (included to indicate the age pole in the analysis, see bianucci et al. 2001), whereas a2 includes middle and late villafranchian lfas, as well as early galerian ones. accordingly, the separation between triversa and montopoli fus seems to be the most significant within the afc, emphasising the importance of the transition from early to middle villafranchian (an important turnover phase) with respect to that from the middle to late villafranchian (prevalently a dispersal phase) (palombo, 2004). within the a2 subcluster, a gap separates the a2.1 group, including middle + early late villafranchian lfas (from montopoli to tasso fus), from the a2.2 group including the latest villafranchian + early galerian lfas (from farneta to colle curti fus). actually, early late villafranchian complexes (olivola and tasso fus) were relatively static and quite homogeneous; moreover, the presence of long-persistent and frequent middle villafranchian taxa (such as mammuthus meridionalis, stephanorhinus etruscus and equus stenonis) can explain their greater resemblance to middle villafranchian lfas than to subsequent latest villafranchian ones. an extinction phase followed, during which last occurrences surpassed new ones. this phase culminated at the pirro/colle curti fu transition with a moderate turnover, due to the appearance in the course of time of some new taxa typical of the middle pleistocene (table 1). a minor gap separates the group of lfas belonging to the farneta fu from the group of pirro and colle curti fus, thus pointing out the strong similarities between latest villafranchian and early galerian italian lfas. actually, pirro nord and colle curti lfas show a relatively high similarity coefficient (jaccard index = 0.3), due to the presence of several common taxa (carnivores, rhinoceros, hippopotamus) in both localities. this fact markedly reduces the importance of the occurrence of “praemegaceros” verticornis in the colle curti lfa. within cluster b, including middle pleistocene lfas, group b1 stands apart, probably because the flas included share few taxa with other middle and late galerian lfas due to low richness (borgo nuovo, monte oliveto, pagliare di sassa) or the occurrence of peculiar taxa, such as mammuthus meridionalis in the monte tenda lea and hemibos galerianus in the ponte galeria lfa. within b2, group b2.1 includes middle and late galerian lfas. the valdemino lfa shows a low similarity coefficient and stands apart from the other lfas, probably due to the occurrence of panthera pardus, not recorded in other italian galerian lfas, and the generic identification of some taxa such as ursus sp. group b2.1 includes lfas attributed to the torre in pietra fu (e.g. la polledrara, castel di guido, malagrotta, sedia del diavolo, torre in pietra lower level, correlated with mis 9 and vitinia, casal de’ pazzi, torre in pietra upper level correlated with mis 7), although it is difficult to justify the clustering of groups of minor rank, probably because of the basic homogeneity of this faunal complex. on the basis of our results and taking into account both the biochronological significance of some rare taxa and the influence of long-lived ones, we will operationally consider clusters a and b as high rank biochrons (a = “archaic faunas complex ”afc, and b = “modern faunal complex” mfc) and the following groups as possible biochrons of lower rank: i = early villafranchian (a1); ii = middle villafranchian + late villafranchian (a2.1); iii = latest villafranchian + early galerian (a2.2); iv = middle and late galerian (b1); v = early aurelian (b2) (fig. 2). in addition, the two groups of middle (a2.1.1) and early late villafranchian (a2.1.2) should also be regarded as possible biochrons due to their low similarity coefficient. 4. remarks the transition from early to middle pleistocene faunas (from early to middle galerian mas, sensu gliozzi et al. 1997), coinciding with the onset of 100 ka climate cyclicity and vegetational changes, represents major community reorganisation in the western mediterranean area (see e.g. azanza et al., 1999, in press; palombo & valli, in press; palombo et al., in press and references therein). the importance of this renewal and ecological reorganisation is highlighted by the clear separation between clusters of “archaic” (villafranchian + early galerian, middle pliocene and early pleistocene) and “modern” (middle, late galerian + early aurelian, middle pleistocene) italian mammal faunas, as well as by the aeo. this change results from a moderate turnover, taking place at the pirro-colle curti fu transition, followed by marked faunal renewal at the beginning of the middle pleistocene. this evidence encourages reconsideration of the definition of galerian land mammal age (lma) previously proposed for italian mammalian faunas. indeed, as mentioned above, according to gliozzi et al. (1997), the appearance of “praemegaceros” verticornis, first recorded in italy in the colle curti lfa, conventionally marks the beginning of the galerian lma. however, this fauna seems more similar to villafranchian than to ensuing “true” galerian lfas, and the renewal between colle curti and slivia fus was more significant than that between pirro and colle curti fus (table 1; fig. 3). moreover, and as far as large italian mammals are concerned, analysis results confirm that during the late pliocene and pleistocene, the most important faunal renewals (due both to originations /immigrations and extinctions) are linked to major global climatic changes. faunal renewal (“elephant-equus event”, lindsay et al., 1980; azzaroli 1983; azzaroli et al., 1988) from the early to middle villafranchian faunal complexes, linked to pliocene climate worsening, is responsible for the slight similarity between a1 and a2 subclusters. this renewal may be regarded as a true turnover phase due to the high percentage of last and new appearances and the important ecological structural change in faunal complexes, involving both herbivore and carnivore guilds. moreover, this event may be considered the starting point of a dispersal phase leading to a progressive standing richness increase during the following pliocene and up to the beginning of the early pleistocene, given that new occurrences exceeded last occurrences (fig. 3). on the other hand, even if the so-called “wolf574 m.r. palombo 575biochronology of the ... fig. 2 dendogram qmode for 74 ital ian local faunal assemblages (q-mode) based on un-weighted data for 136 taxa. ccc = 0.92936. abbreviations: pugna= val di pugna; ponzano= ponzano di magra; gav/barb.= gavil le santa barbara; p. fosciana= pieve fosciana; c.toppetti= cava toppetti; c.giacomo= costa san giacomo; v.caten= valle catenaccio c. pardo= colle pardo; t.picchio= torre picchio; mt.riccio= monte riccio; c.sgherri= casa sgherri; vald a r n o s 1 = u p p e r valdarno 1; poggio ros= poggio rosso; valdarnos2= upper valdarno 2; b. tiberino= bacino tiberino; f.acetosa= fontana acetosa; m.strada = madonna della strada; val chiana = val di chiana; pirro = pirro nord; c.curti = colle curti; mt.tenda = monte tenda; p. galeria = ponte galeria; sassa = pagliare di sassa; mtoliveto = monte oliveto; borgon. = borgonuovo; isernia = isernia la pineta; ranuccio = fontana ranuccio; notarch. = notarchirico; loreto = venosa-loreto; s.diavolo = sedia del diavolo; capriq. = capriquisisana; vit inia = vitinia, upper levels (mis 7); c.mont. = contrada monticelli; cverde = campo verde; t.pietra1 =torre in pietra , lower levels (mis 9); gr.rom. = grotta romanelli, lower levels; mt.gioie = monte delle gioie; cpazzi = casal de’ pazzi; malagr. = malagrotta; polled. = la polledrara di cecanibbio; t.pietra2 = torre in pietra, upper levels (mis 7); grlina = grotta lina; cguido = castel di guido; pfiscali = prati fiscali; grmbern. = grotta maggiore di san bernardino; pontec. = pontecorvo; t.conca = torrente conca; fsabina = fara sabina. dendogramma q-mode ricavato per 74 faune locali italiane (q-mode) sulla base dell’analisi di 136 taxa. ccc = 0.92936. abbreviazioni: pugna= val di pugna; ponzano= ponzano di magra; gav/barb.= gaville santa barbara; p. fosciana= pieve fosciana; c.toppetti= cava toppetti; c.giacomo= costa san giacomo; v.caten= valle catenaccio c.pardo= colle pardo; t.picchio= torre picchio; mt.riccio= monte riccio; c.sgherri= casa sgherri; valdarnos1=upper valdarno 1; poggioros= poggio rosso; valdarnos2= upper valdarno 2; b.tiberino= bacino tiberino; f.acetosa= fontana acetosa; m.strada = madonna della strada; val chiana = val di chiana; pirro = pirro nord; c.curti = colle curti; mt.tenda = monte tenda; p.galeria = ponte galeria; sassa = pagliare di sassa; mtoliveto = monte oliveto; borgon. = borgonuovo; isernia = isernia la pineta; ranuccio = fontana ranuccio; notarch. = notarchirico; loreto = venosa-loreto; s.diavolo = sedia del diavolo; capriq. = capri-quisisana; vitinia = vitinia, upper levels (mis 7); c.mont. = contrada monticelli; cverde = campo verde; t.pietra1 =torre in pietra , lower levels (mis 9); gr.rom. = grotta romanelli, lower levels; mt.gioie = monte delle gioie; cpazzi = casal de’ pazzi; malagr. = malagrotta; polled. = la polledrara di cecanibbio; t.pietra2 = torre in pietra, upper levels (mis 7); grlina = grotta lina; cguido = castel di guido; pfiscali = prati fiscali; grmbern. = grotta maggiore di san bernardino; pontec. = pontecorvo; t.conca = torrente conca; fsabina = fara sabina. 576 m.r. palombo fig. 3 – biochronology, standing richness and turnover changes of italian large mammal faunas from middle pliocene to late pleistocene. standing richness value was calculated according to harper’s method (harper, 1975) (nsr = nbda + nrt + 1/2 (nf + nl– no) where nsr = number of taxa that potentially occur at a given time interval, nbda = number of species present before-during and after the faunal unit, nrt = number of species present before and after but not in the faunal unit, nf = number of first appearances, nl = number of last appearances, no = number af taxa present only in the faunal unit). faunal renewal was evaluated considering all occurrences at the transition between two successive fus (turnover index, ti =% fa + % la / 2 as in torre et al., 1999). biocronologia, ricchezza standarizzata e rinnovi faunistici delle faune a grandi mammiferi della penisola italiana dal pliocene medio al pleistocene superiore. la ricchezza standardizzata è stata calcolata secondo la formula proposta da harper (1975): nsr = nbda + nrt + 1/2 (nf + nl– no); nsr = numero pesato dei taxa presenti nell’intervallo considerato, nbda = numero di specie presenti prima, durante e dopo l’intervallo considerato, nrt = numero dei taxa presenti prima e dopo, ma non durante l’intervallo di tempo considerato, nf = numero delle prime comparse, nl = numero delle ultime comparse, no = numero dei taxa presenti solo nell’intervallo considerato. l’indice di rinnovo è stato calcolato valutando il numero totale di taxa, le prime comparse e le scomparse alla transizione tra due successivi intervalli, secondo la formula ti =% fa + % la / 2 come in torre et al. (1999). event” (azzaroli 1983, azzaroli et al., 1988), seems to be a more gradual phenomenon than previously supposed, middle vil lafranchian lfas and early late villafranchian lfas form separate groups within a2.1, clearly separated from the group including late early pleistocene lfas, in which taxa phylogenetically related to or identical to galerian middle pleistocene ones progressively appeared, while “pliocene species” were no longer present. finally, similarity analysis results confirm the basic homogeneity of late middle pleistocene lfas. consequently, without stratigraphic constraints it is difficult to arrange these assemblages in a chronological sequence that is ascribing them to a specific mis. given these considerations, the biochronology of plio-pleistocene italian mammal faunas should be reevaluated, taking the following factors into account: “biochrons” represent time lapses during which faunas have a degree of taxonomic homogeneity; the “faunal complex” belonging to each biochron might be regarded as nonoverlapping and an "ecologically adjusted group of animals with specific geographic limits and chronological range" (tedford, 1970, pag. 602); actually, biochronology, a theoretical discipline, operationally depends on the empirical documentation of the stratigraphic ranges of fossils in superimposed sections; relative or absolute deposition dates for rock-bodies in which fossil remains are first/last documented respectively correspond only to the “ante quem” or “post quem” time of actual origination and extinction bioevents; the more detailed the bioevent sequence becomes, the more difficult it is to make correlations on a larger scale; moreover, the application of multivariate analysis may be a useful tool in defining faunal complexes having a high degree of similarity. since separation between clusters corresponds to faunal renewal, clusters themselves should have biochronological significance and should be taken into consideration for biochronological correlations. on the basis of the results obtained, the faunal complex corresponding to lfas previously ascribed to fus from farneta to colle curti should be considered as the most advanced biochron in the villafranchian lma; accordingly, the beginning of the galerian lma must correspond to the faunal reorganization occurring at the early to middle pleistocene transition. moreover, the validity and applicability of lower rank biochrons resulting from our multivariate analysis (i = early villafranchian, triversa fu; ii = middle villafranchian + late villafranchian, from montopoli to olivola + tasso fus; iii = latest villafranchian + early galerian, from farneta to colle curti fu; iv = middle and late galerian, from slivia to fontana ranuccio fu; v = early aurelian, torre in pietra fu) need further confirmation. acknowledgements the author expresses her gratitude to prof. b. sala for his comments and suggestions. the english version has been revised by dr. mary groeneweg, english language lecturer at cagliari university. work supported by miur 60% grants 2003, prof. m.r. palombo ("evoluzione degli ecosistemi continentali dell’italia peninsulare durante il plio-pleistocene: un approccio multidisciplinare"). references aguirre e. & pasini g. (1985) the pliocene-pleistocene boundary. episodes, 8 (2), pp. 116-120. agustí j., cabrera l., garcés m., krijgsman w., oms o. & parés j.m. (2001) a calibrated mammal scale for the neogene of western europe. state of the art. earth-science reviews, 52, pp. 247-260. alberdi m. t., azanza b., cerdeño e. & prado j. l. (1997) similarity relationship between mammal faunas and biochronology from latest miocene to pleistocene in western mediterranean area. eclogae geologicae helvetiae, 90, 115-132. alberdi m.t., caloi l., palombo m.r. (1998) large mammals associations from the early pleistocene: italy and spain. medelingen nederlands inst. toegepaste geowetenschappen tno, 60, pp. 521-532 albianelli, a., azzaroli, a., bertini, a., ficcarelli, g., napoleone, g. & torre d. (1997) paleomagnetic and palynologic investigations in the upper valdarno basin(central italy): calibration of an early villafranchian fauna. riv. ital. paleont. stratigr., 103 (1), pp. 11-118 albianelli a., bertini a., magi m., napoleone g. & sagri m. (1995) i l bacino plio-pleistocenico del valdarno superiore: eventi deposizionali paleomagnetici e paleoclimatici. il quaternario, 8 (1) , pp. 11-18 alroy j. (1992) conjunction among taxonomic distributions and the miocene mammalian biochronology of the great plains. paleobiology, 18(3), pp.326-343 alroy j. (1994) appearance event ordination: a new biochronologic method. paleobiology, 20 (2), pp.191-207, lawrence. alroy j. (1996) constant extinction, constrained diversification, and uncoordinated stasis in north american mammals. palaeogeography, palaeoclimatology, palaeoecology, 127, pp. 285-311, amsterdam. ambrosetti p., azzaroli a., bonadonna f.p. & follieri m. (1972) a scheme of pleistocene chronology for the tyrhenian side of central italy. bollettino della. società geologica italiana, 91, pp. 169-184. arambourg c. (1932) note preliminare sur une nouvelle grotte à ossements des environs d’alger. soc. hist. nat. afrique du nord, 23 , pp. 154-162 arambourg c. (1938) mammiferes fossiles du maroc soc. sci. nat. maroc, mem., 46, pp. 174 archibald j.d., gingerich p.d., lindsay e.h., clemens w.a., krause d.w. & rose k.d. (1987) fist north american land mammal ages of the cenozoic era. in woodburne, m.o. (ed.): cenozoic mammal of north america: geochronology and biostratigraphy, pp. 24-76; university california 577biochronology of the ... press, california. azanza b., alberdi m. t., cerdeño e. & prado,j. l. (1997) biochronology from latest miocene to middle pleistocene in the western mediterranean area. a multivariate approach. in: aguilar, j. l., legendre, s. & michaux, j. (eds) actes du congrès biochrom’97, mémoires des travaux de l’institut de montpellier, montpellier, pp. 567-574. azanza b., alberdi m.t. & prado j.l. (1999) large mammal diversity and turnover patterns during the plio-pleistocene in western mediterranean area. revista de la sociedad geológica de españa, 12 (1), pp. 113-122, madrid. azanza b., palombo m.r. & alberdi m.t. (2002) mammalian biochronological framework of the european plio-pleistocene: some remarks. 3rd french symposium on stratigraphy, july 810/2002, lyon, france azanza b., palombo m.r., & alberdi m.t. (2004) large mammals fauna turnover in italy from pliocene to late pleistocene. rivista italiana di paleontologia e stratigrafia, 110 (2), pp. 531-545 azzaroli a. (1952) la sistematica dei cervi giganti e i cervi nani delle isole. atti soc. tosc. sci. nat., mem.(a), 59 , pp. 119-127 azzaroli a. (1977) the villafranchian stage in italy and the plio-pleistocene boundary. giornale di geologia, 41, pp. 61-79. azzaroli a. (1979) critical ramarks on some giant deer (genus megaceros owen) from the pleistocene of europe. palaeontografia italica, n.s. 41, 71, pp. 516 azzaroli a. (1982) remarques sur les subdivisions chronologiques du villafranchien. actes colloque "le villafranchien mediterranéen", lille 9-10 décembre 1982, 1, pp. 7-14. azzaroli a. (1983) quaternary mammals and the “end-villafranchian” dispersal event a turning point in the history of eurasia. palaeogeography, palaeoclimatology, palaeoecology, 44, pp. 117139. azzaroli a. (1991) some problems of mammalian stratigraphy for the pleistocene of western europe. i.u.q.s. special proc. rev. rep., xiii inqua congres, august 2-9. 1991, beijing china, 130-143 azzaroli a., de giuli c., ficcarelli g. & torre d. (1988) late pliocene to early mid-pleistocene mammals in eurasia: faunal succession and dispersal events. palaeogeography, palaeoclimatology, palaeoecology, 66, pp. 77-100. azzaroli a. & mazza p. (1992) the cervid genus eucladoceros in the early pleistocene of tuscany. palaeont. ital., 79, pp. 43-100 berggren w.a., hilgen f.j., langereis c.g., kent d.v., obradovich j.d., raffi i., raymo m.e. & shackleton n.j. (1995a) late neogene chronology: new perspectives in high-resolution stratigraphy. bulletingeology society american, 107, pp. 12721287. berggren w.a., kent d.v., aubry m.p. & hardenbol j. (1995b) geochronology, time scales and global stratigraphic correlations. sepm special publication, 54, pp. 1-386. berggren w.a. & j.a. van couvering (1978) biochronology. in cohee g.v., glaessner m.f. & hedberg h.d. (eds.): contribution to the geologic time scale. american association of petroleum geologists bulletin, 50, pp. 1487-1500. bertini a. (2000) pollen record from colle curti and cesi: early and middle pleistocene mammal sites in the umbro-marchean apennine mountains (central italy). journal of quaternary science, 15, 825-840. bertini a. & roiron p. (1997) evolution de la végétation et du climat pendant le pliocène moyen en italie centrale: apport de la palynologie et des macroflores à l’étude du bassin du valdarno supérieur, (coupe de santa barbara). comptes. rendus de l’académie des sciences, paris, sér. 2a, 324, pp. 763-771 bianucci g., mazza p., merola d., sarti g. & cascella a. (2001) the early pliocene mammal assemblage of val di pugna (tuscany, italy) in the light of calcareous plankton biostratigraphicaldata and paleoeological observations. riv. ital. paleont. stratigr., 107 (3), pp. 425-438. biddittu i, cassoli p.f., radicati di brozolo f., segre a.g., segre-naldini e., villa i., (1979) anagni a k/ar dated lower middle pleistocene site, central italy: preliminary report. quaternaria, 21. 53-71 bœuf o. (1997) a propos de chilhac, senèze, blassac-la-girondie (haute-loire, france), gisements du pliocène terminal, leur intérêt biochronologique. in aguilar j.-p., legendre s., michauxi j. (eds): european neogene mammal chronology, pp. 661-668, mém. trav. e.p.h.e., inst. montpellier. borselli v, de giuli c., ficcarelli g. & mazzini m. (1980) casa frata: una località fossil i fera del villafranchiano superiore presso terranuova bracciolini (arezzo) nel valdarno superiore. boll.soc. pal.it., 19, pp. 245-258, brett c.e, ivany l.c. & schopf k.m (1996) coordinated stasis: an overview. palaeogeography, palaeoclymatology, palaeoecology, 127, 1-20 bruijn h. de, daams r., daxner-höck g., fahlbusch v., ginsburg l., mein p. & morales j. (1992) report of the rcmns working group on fossil mammals, reisensburg 1990. newsletter stratigraphy, 26, pp. 65-118. caloi l. & palombo m.r. (1990) osservazioni sugli equidi italiani del pleistocene medio inferiore. geologica romana, 26 (1987), pp. 187-221, caloi l. & palombo m.r. (1995) biocronologia e paleoecologia delle mammalofaune del pleistocene medio dell’italia centrale. studi geologici camerti, vol. spec. 1994 (b), pp. 503-514 caloi l. & palombo m.r. (1996) latest early pleistocene mammal faunas of italy, biochronological problems. il quaternario, 8 (2), pp. 391-402 caloi l. & palombo m. r. (1999) rapporti tra carnivori ed erbivori, prede e predatori nel pliocene mediopleistocene medio della penisola ital iana. geologica romana, 34 (1998), pp. 115-129 caloi l. & palombo m.r. & zarlenga f. (1998) late middle pleistocene mammals faunas of latium; stratigraphy and environment . quaternari international, 47/48, pp. 77-86 carraro f. (1996) revisione del villafranchiano nell’area -tipo di villafranca d’asti. il quaternario, 9 (1), 578 m.r. palombo pp. 5-120 cassoli p. & segre naldini e. (2000) les gisements du pléistocène myenne ed inférieur du latium meridional. coll. inter."les premieres habitants de l'europe, tautavel 10-15 avril 2000, resumes de communications, pp. 34-35 cita m.b. & castradori d. (1995) workshop on marine sections from the gulf of taranto (southern italy) usable as potential stratotypes for the gssp of the lower, middle and upper pleistocene. il quaternario, 7 (2), pp. 677-692. coltorti m., albianelli a., bertini a., ficcarelli g., napoleone g. & torre d. (1998) the collecurti mammal site in the colfiorito area (umbrianmarchean apennines): stratigraphy and palynological analysis. quaternary international, 47/48, pp. 77-86 coltorti m., ton-that t., marzoli a., arzarello m., buoso n., corrado s., di bucci d., minelli a., naso g., peretto c., thun hohenstein u., villa i. (2000) new chronostratigraphic and paleoclimatic data from the “isernia la pineta” site, molise, italy. in: subcommission on european quaternary stratigraphy (seqs), 2000 meeting the plio-pleistocene boundary and the lower/middle pleistocene transition: type areas and sections: abstracts. cregut-bonnoure e. & n. spassov. (2002) hemitragus orientalis nov. sp. (mammalia, bovidae, caprinae), un nouveau taxon d’europe orientale. rev. paléobiol. 21(2), pp. 553-573 croitor r. (2004) systematics and phylogeny of largesized deer oh the genus praemegaceros portis, 1920 (cervidae, mammalia). in kahlke r-d. & maul l. (eds.) late neogene and quaternary biodiversity and evolution. 18th international senckenberg conference, weimar 25th-30th april, 2004.terra nostra, 2004/2, pp 89-90 daams r. & freudenthal m. (1981) aragonian: the stage concept versus neogene mammal zones. scripta geologica, 1, pp. 1-17. daams r., alcalá l., alvarez-sierra m.a., azanza b., van dam j., van der meulen j., morales j., nieto m., peláez-campomanes p. & soria d. (1998) a stratigraphical framework for miocene (mn4mn13) continental sediments of central spain. comptes rendus de l'academie de sciences de paris, s. iia, 327, pp. 625-631. de giuli c. & masini f. (1987) late villafranchian faunas in italy: the casa frata local fauna (upper valdarno, tuscany). palaeontogr.ital., 74 (1986), 1-9. de giuli c., ficcarelli g., mazza p. & torre d. (1983) confronto tra successioni marine e continentali del pliocene e pleistocene inferiore in italia e nell'area mediterranea. bollettino della società paleontologica italiana, 22, pp. 323-328. di stefano g. & petrolio c. (2003) systematics and evolution of the eurasian plio-pleistocene tribe cervini (artiodactyla, mammalia. geologica romana, 36 (200-2002), pp. 311-334. emry r.j., bjork p.r. & russell l.s. (1987) the chadronian, orellan, and whitneyan north american land mammal ages. in woodburne, m.d. (ed.): cenozoic mammals of north america, pp. 118-152; university of california press, california. fejfar o., heinrich w-d. & lindsay e.h. (1998) updating the neogene rodent biochronology in europe. mededelingen nederlands instituut voor toegepaste geowetenschappen tno, 60, pp. 533-551. fernández lópez s. (1991) taphonomic concepts for a theoretical biochronology. revista española de paleontología, 6(1), pp. 37-49. flynn j.j., macfadden b.j. & mckenna m.c. (1984) land mammal ages, faunal heterochroneity, and temporal resolution in cenozoic terrestrial sequences. journal of geology, 92, pp. 687-705. gliozzi e., abbazi l., ambrosetti p., argenti p., azzaroli a., caloi l., capasso barbato l., di stefano g., esu d., ficcarelli g., girotti o., kotsakis t., masini f., mazza p., mezzabotta c., palombo m.r., petronio c., rook l., sala b., sardella r., zanalda e. & torre d. (1997) biochronology of selected mammals, molluscs, ostracods from the middle pliocene to the late pleistocene in italy. the state of the art. rivista ital iana di paleontologia i stratigrafia, 103 (3), pp. 369-388. guerin c. (1982) première biozonation du pléistocène européen: principal résultat biostratigraphique de l’étude des rhinocerotidae (mammalia, perissodactyla) du miocène terminal au pléistocène supérieur d’europe occidentale. geobios, 15, pp. 593598. guerin c. (1990) biozones or mammal units? methods and limits in biochronology. in: lindsay, e.h., fahlbusch, v. & mein, p. (eds): european neogene mammal chronology, pp. 119-130; plenum press, new york. harper c.w. jr. (1975) standing diversity of fossil group in successive intervals of geologic time: a new mesur. journal of paleobiology, 4, pp. 181207 hazel j.e. (1970) binary coefficients and clustering in biostratigraph. bulletin geological american society, 81, pp. 3237-3252. heintz e. (1970) les cervidés villafranchiens de france et d’espagne. bull. mus. natn. hist. nat., paris, sér. c, 22, p.303 karner d.b., marra f. & renne p.r. (2001) the history of the monti sabatini and alban hills volcanoes: groundwork for assessing volcanic-tectonic hazards for rome. jour. volcanol. geother. res., 107, pp.185-219. kolfschoten t. van & gibbard p.l. (1998) the dawn of the quaternary: an introduction. medelingen nederlands instituut voor toegepaste geowenshappen tno, 60, pp. 1317 koufos g.d. (2003) late miocene mammal events and biostratigraphy in the eastern mediterranean in: reumer, j.w.f. & wessels, w. (eds.): distribution and migration of tertiary mammals in eurasia. a volume in honour of hans de bruijn. deinsea, 10, pp. 343-371 krishtralka l., west r.m., black c.c., dawson m.r., flynn j.j., turnbull w.d., stucky r.k., mckenna m.c., bown t.m., golz d.j. & lillegraven j.a. (1987) eocene (wasachian through duchesnean) biochronologyof north america. in woodburne, m.o. (ed.): cenozoic mammal of north america. 579biochronology of the ... geochronology and biostratigraphy, pp. 77-117; university califronia press, california. joleaud l. 1914 sur le cervus (megaceroides) algericus leydekker (sic !) 1890. rec. soc. archéol . costantine, 49, pp.737-739 lefèvre d. & raynal j.p. (1999) etudes géologique à notarchirico et dans le bassin de venosa: premier bilan et perspectives. in piperno m. (ed.): notarchirico. un sito del pleistocene medio iniziale nel bacino di venosa, pp. 253-258; edizioni osanna, italia. lefèvre d., raynal j.p.& vernet g. (1999) enregistrements pléistocènes dans le bassin de venosa. in piperno m. (ed.): notarchirico. un sito del pleistocen medio iniziale nel bacino di venosa”, pp. 139-174; edizioni osanna, italia. lindsay e.h. (1985) european late cenozoic biochronology and the magnetic polarity time scale. national geograohy society research repport, pp. 449-456. lindsay e.h. (1997) correlation of eurasian late cenozoic mammal chronology with the magnetic polarity time scale. palaeogeography, palaeclimatology, palaeoecology, 133, pp. 1-288. lindsay e.h. (2001) correlation of mammal biochronology with the magnetic geomagnetic polarity time scale. in rook l. & torre d. (eds.): neogene and quaternary continental stratigraphy and mammal evolution. papers in honour of prof. augusto azzaroli’s outstanding contribution in geology and paleontology. bollettino della società paleontologica italiana, 40(2) , pp. 225-233 lindsay e.h. (2003) chronostratigraphy, biochronology, datum events, land mammal ages, stage of evolution, and appearance event ordination. bulletin of the american museum of natural history: no. 279, pp. 212-230. lindsay e.h., opdyke n.d. & johnson n.m. (1980) pliocene dispersal of the horse equus and late cenozoic mammalian dispersal events. nature, 287, pp. 135-138. lindsay e.h. & tedford r. (1990) development and application of land mammal ages in north america and europe, a comparison. in lindsay e.h., fahlbusch v. & mein p. (eds.): european neogene mammal chronology, pp. 601-624; plenum press, new york. lister a. (1992) mammalian fossils and quaternary biostratigraphy. quaternary science reviews, 11, pp. 329-344. lucas s.g. (1992) redefinition of the duchesnean land mammal "age", late eocene of western north america. in prothero r. & berggren w.a. (eds.): eocene-oligicene climatic and biotici evolution, pp. 88-105; princeton university press. lydekker r. (1890) on cervine jaw from algeria. proc. zool. soc. london, 1890, pp. 602-604 marra f. & rosa c. (1995) stratigrafia e assetto geologico dell’area romana. mem. descr. carta geol. d’italia, 50, pp. 49-118 martinez-navarro b. & palombo m. r. (2004) occurrence of the indian genus hemibos (bovini, bovidae, mammalia) at the early-middle pleistocene transition in italy. quaternary research, 61, 314317. martinez-navarro b. & rook l. (2003) gradual evolution in the african hunting dog lineage. systematic implications. compte rendue paleoevolution, 2, pp. 695-702. mazza p., bertini a. & magi m. (2004) the late pliocene site of poggio rosso (central italy): taphonomy and paleoenvironment. palaois. 19, pp. 217-248 mazzini m., borselli v., cioppi e. & napoleone g. (2000) poggiorosso: un importate arricchimento delle faune villafranchiane a vertebrati del valdarno superiore, di età prossima al l imite pliopleistocene. bollettino della società paleontologica italiana, 39, pp. 381-388 mein p. (1975) résultats du groupe de travail des vertébrés: bizonation du néogène méditerranéen à partir des mammifères. report activity rcmns working groups, bratislava, 78-81. mein p. (1990) updating of mn zones. in lindsay e.h., fahlbusch v. & mein, p. (eds.): european neogene mammal chronology. plenum press, new york, nato asi ser., 180, pp. 73-90. mein p. (1998) biochronologie et phases de dispersion chez les vertébrés cénozoïques. bull. soc. géol. france, 170 (2), pp. 195-204. milli s., palombo m. r., petronio, c. & sardella s. (2004) sedimentary sequenze and mammal biochronology: the case of middle pleistocene of the campagna romana area. riv. it paleont. strat., 110, pp. monguillon-douillet a. (2000) les carnivores du site plio-pleistocène de chilhac (haute-loire, france) etude paléontologique, biochronologique, paléoécologique et taphonomique. mémoire de d.e.a. “quaternaire : géologie, paléontologie humaine, préhistoire”, paris, 95 p morrison, r. & kukla. g. (1998) the pliocenepleistocene (tertiary-quaternary) boundary should be placed at about 2.6 ma, not at 1.8 ma. gsa today 8 (8), p. 9. napoleone g., azzaroli a., albianelli a. & mazzini m. (2001) -the poggio rosso locality calibrated to the end-pliocene and its significance for dating the late villafranchian mammal faunas of the upper valdarno, central italy. rivista italiana di paleontologia e stratigrafia, 107 (2), pp.287-296 napoleone g. & azzaroli a. (2002) a collection of fossil vertebrates from the upper valdarno (central italy) calibrated in the end pliocene to span 220,000 years across the olduvai magnetochron. rivista italiana di paleontologia e stratigrafia, 108, pp. 479-492. napoleone g., azzaroli a. & mazzini m. (2003) magnetochronologic significance of the endpliocene age of the new found locality of poggio rosso in the upper valdarno, for dating its late vil lafranchian faunas . rivista ital iana di paleontologia e stratigrafia, 108 (3), pp. 479-492 nocchi g. & sala b. (1997) the fossil rabbit from valdemino cave (borgio verezzi, savona) in the context of western europe oryctolagini of quaternary. palaeovertebrata, 26(1-), pp. 167-187 opdyke n., mein p., lindsay e., pérez-gonzález a., moissenet e. & norton v.l. (1997) continental deposits, magnetostratigraphy and vertebrate 580 m.r. palombo paleontology, late neogene of eastern spain. palaeogeography, palaeclimatology, palaeoecology, 133, pp. 129-148. palombo m.r. (1995) le principali associazioni a mammiferi del pliocene dell’italia centrale. studi geologici camerti, vol. spec. 1994 (b) , pp. 429446 palombo m.r. (2004) guild of large mammals from the pliocene to the late pleistocene in the italian peninsula. in baquedano, e. & rubio, s. (eds). homenaje a emiliano aguirre. zona paleontologica, museo arqueológico regional, madrid. palombo m.r. & ferretti m. (2005 )elephant fossil record from italy: knowledge, problems, and perspectives. quaternary international, 126-128, pp. 107-136 palombo m.r. & mussi, m (2001) human presence and faunal evolution in the middle pleistocene of italy. in rook,. l., torre, d. (eds.): neogene and quaternary continental stratigraphy and mammal evolution. papers in honuor of prof. augusto azzaroli’s outstanding contribution in geology and paleontology. bollettino della società paleontologica italiana, 40 (2), pp. 257-267 palombo m.r. & valli a. (2004) similarities between large mammal faunas of the italian peninsula and france from the pliocene to the middle pleistocene. neues jarbuch fur geologie und paleontologie, abh, 233(1), 69-102. palombo m.r., azanza b. & alberdi m.t. (2003) italian mammal biochronology from latest miocene to middle pleistocene: a multivariate approach. geologica romana, 36 (2000-2002), pp. 335-368. palombo m.r, milli s. & rosa c. (2004) remarks on the late middle pleistocene biochronology of the mammalian faunal complexes of the campagna romana. geologica romana 37 (2003) palombo m.r., raia p. & giovinazzo c. (in press) earlymiddle pleistocene structural changes in mammalian communities from the italian peninsula. in head m.j. & gibbard p.l. (eds.) early-middle pleistocene transition: the land-ocean evidence, geological society, london. palombo m.r., abbazzi l., agostini, mazza p. & mussi m. (2001) middle pleistocene faunas and lithic implements from pagliara di sassa (l'aquila, central italy). in cavaretta g., gioia p., mussi m. & palombo m.r. (eds.) the world of elephants, pp. 224-229, pubbl. cnr, roma pareto m. (1865) note sur la subdivision que l’on porrait établir dans les terrains de l’apennin septentrional. bulletin de la societé géologique de france, série 2, 22, pp. 210-277. petronio c. & sardella r. (1999) “biochronology of he pleistocene mammal fauna from ponte galeria (rome) and remarks on the middle galerian faunas”. rivista ital iana di paleontologia e stratigrafia, 105 (1), pp. 155-164 pickford m. (1990) dynamics of old world biogeographic realms during the neogene: implications for biostratigraphy. in lindsay e.h., fahlbusch v. & mein p. (eds.): european neogene mammal chronology, pp. 413-442; plenum press, new york. prothero d.r. (1995) geochronology and magnetostratigraphy of paleogene north american land mammal "ages": an update. in berggren w.a., kent d.v. & hardenbol j. (eds.): geochronology, time scales and global stratigraphic correlations, pp. 305-315; sepm, special publication,p.54; tulsa, oklahoma. ravazzi c. (2003) an overview of the quaternary continental stratigraphic units based on biological and climatic events in italy. il quaternario volume speciale inqua,16(1bis), pp. 11-18 richmond g. m. (1996) the inqua-approved provisional lower-middle pleistocene boundary. in: turner, c. (ed.) the early-middle pleistocene in europe. balkema, rotterdam, 319-326. rohlf, f.j. (1998) ntsys-pc numerical taxonomy and multivariate analysis system. version 2.0. exeter software, ltd., new york. sala b., masini f., ficcarelli g., rook l. & torre d. (1992) mammal dispersal events in the middle and late pleistocene of italy and water europe. courier forsch.-inst. seckenberg, 153, pp. 58-68 salvador a. (1994) international stratigraphic guide. a guide to stratigraphic classification, terminology, and procedure, 214 pp., the geological society of america, boulder sardella r. (2004) late villafranchian and galerian carnivores (mammalia) fron the tyrrhenian coastal area of central italy. in kahlke r-d. & maul l. (eds.) late neogene and quaternary biodiversity and evolution. 18th international senckenberg conference, weimar 25th-30th april, 2004.terra nostra, 2004/2, p. 228. shackleton n.j. (1995) new data on the evolution of pliocene climatic variability. in: vrba e.s., denton g.h., partridge t.c. & burckle l.h. (eds.): paleoclimate and evolution, with emphasis on human origins. pp. 242-248; yale university press (1996), new haven and london. schoch r.m. (1989) stratigraphy: principles and methods. van nostrand reinhold, new york, 375 p. sen s. (1997) magnetostratigraphic calibration of the european neogene mammal chronology. palaeogeography, palaeoclimatology, palaeoecology, 133, pp. 181-204. shi g.r. (1993) multivariate data analysis in palaeoecology and palaeobiogeography -a review. palaeogeogr. palaeoclimatol. palaeoecol., 105, pp. 199-234. suc j.-p., bertini a., combourieu-nebout n., diniz f., leroy s., russo-ermolli e., zheng z., bessais e. & ferrier j. (1995) “structure of west mediterranean vegetation and climate since 5.3 ma. acta zoologica cracoviense, 38(1), pp. 3-16, polonia. suc j.-p., bertini a., leroy s.a.g. & suballyova d. (1997) towards the lowering of the pliocenepleistocene boundary to the gauss-matuyama reversal. quaternary international, 40, pp. 37-42, oxford tedford r.h. (1970) principles and practices of mammalian geochronology in north america. american paleontology convenction chicago, 1969, proc. f, pp. 666-703. torre d. (1987) pliocene and pleistocene marine-continental correlations. ann. inst. geol. publ. hung, 581biochronology of the ... 70, pp. 71-77 torre d., rook, l. & ficcarelli, g. (1999) -the mammal fauna turnover in italy at the early to middle pleistocene transition”. in: gibert g., sanchez f., gibert, l. & ribot, f. (eds.) the hominids and their environment during the lower and middle pleistocene of eurasia: 541-548. museo de prehistoria y paleontologia “j. gibert”, orce torre d., ficcarelli g., masini f., rook l. & sala b. (1992) mammal dispersal events in the early pleistocene of western europe. courier forschungsinstitut senckenberg, 153, pp. 51-58. torre d., albianelli a., bertini a., ficcarelli g., masini f. & napoleone g. (1996) paleomagnetic calibration of plio-pleistocene mammal localities in central italy. acta zoologica cracoviensia, 39 (1), pp. 559-570 torre d., abbazzi l., bertini a., fanfani f., fiiccarelli, g., masini f., mazza p., rook, l. (2001) structural changes in italian late pliocene pleistocene large mammal assemblages. in rook l., torre d. (eds.): neogene and quaternary continental stratigraphy and mammal evolution. papers in honuor of prof. augusto azzaroli’s outstanding contribution in geology and paleontology. bollettino della società paleontologica italaliana, 40 (2), pp. 303-306 van dam j.a. (1997) the small mammals from the upper miocene of the teruel-alfambra region (spain). paleobiology and paleoclimatic reconstructions. geológica ultraiectina, 156, pp. 1-204. van dam j.a. (2001) the upper miocene mamad record from the teruel-alfambra region (sapin). the mn system and continental stage/age concepts discussed. jounal of vertebrate paleontology, 21 (2), pp. 367-385. van dam j.a. (2003) european neogene mammal chronology: past, present and future. in reumer j.w.f. & wessels w. (eds.): distribution and migration of tertiary mammals in eurasia. a volume in honour of hans de bruijn deinsea 10, pp. 85-95 viret j. (1961) artiodactyla. in piveteau j. : traité de paléontologie, 6 (1), pp. 887-1021 walsh s.l. (1998) fossil datum and paleobiological event terms, paleontostratigraphy, chronostratigraphy and the definition of land mammal "age" boundaries . journal of vertebrate paleontology, 18 (1), pp. 150-179 woodburne m.o. (1977) definition and characterization in mammalian chronostratigraphy. journal of paleontology, 51, pp. 220-234 woodburne m.o. (1987) cenozoic mammal of north america: geochronology and biostratigraphy. university califronia press woodburne m.o. (1996) precision and resolution in mammalian chronostratigraphy: principles, practise, examples. journal of vertebrate paleontology, 16, pp. 531-555 zanchetta m. & mazza p. (1996) anancus arvernensis remains from the basal portion of the arctica islandica-bearing marine deposits of lower valdarno. bollettino della società geologica italiana, 115, pp. 105-113. 582 ms. ricevuto il 22 giugno 2004 testo definitivo ricevuto il 30 novembre 2004 ms. received: june 22, 2004 final text received: november 30, 2004 imp.de waele et al. geosites and landscape evolution of the tacchi: an example from central-east sardinia jo de waele, felice di gregorio, roberto follesa & giuseppe piras department of geology, via trentino 51, 09127 cagliari e-mail: geoam@unica.it abstract: j. de waele et al., geosites and landscape evolution of the tacchi: an example from central-east sardinia. (it issn 03943356, 2005). the tacchi area is a landscape unit located to the south of the gennargentu mountains in the central-eastern part of sardinia, mainly characterised by table-like carbonatic mesozoic mountains, locally named "tacchi", unconformably overlaying a paleozoic peneplain constituted of cambro-silurian silty and sandy shales. the tacchi are the result of a complex geologic history, deriving from a unique and widespread jurassic carbonatic cover that was split up in clods due to epirogenetic movements, faulted, uplifted or lowered and successively eroded and isolated by fluvial processes. the palaeo-geography and the evolution of this landscape can be explained using several different geosites of the area, such as the san giorgio gorge, the su marmuri cave and the monte tisiddu tacco that, united in a network of geosites, can bring to an improvement of the tourist offer of this interesting area. besides these geosites many other places of geological interest such as the riu pardu river and its abandoned villages of gairo vecchio and osini vecchio (partially destroyed by phenomena of hydrogeologic hazard during the xxth century and especially following an exceptional rainfall in october 1951), several waterfalls and travertine deposits can be mentioned, completing an already rich and varied landscape. the project aims to the conservation of the geodiversity and the multiple valences present in the territory, and comprises the valorisation of the sites of geological interest in line with the principles of a sustainable development. this valorisation foresees the realisation of a local network of geosites connected to the system of natural monuments instituted by the regional law 31/1989, the arrangement of equipped pathways, the elaboration of explicative documents and panels in which geology, geomorphology, karst landscape, biology, archaeology and human settlements and processes are described. some panels will be focalised on the reading of the landscape and its evolution (lecture du paysage) in which geological, geomorphological and environmental aspects collimate to form an educational model of great suggestion. this proposal of valorisation of these geosites, grouped in a network, could well be applied to other areas, and the authors hope that the regional and local stakeholders will, in the near future, participate in the geo-environmental preparation of their territory, giving an important service to the many tourists that come and visit the tacchi area. riassunto: j. de waele et al., geositi e evoluzione del paesaggio dei tacchi: un esempio dalla sardegna centro orientale. (it issn 0394-3356, 2005). l'area dei tacchi è un'unità di paesaggio situata a sud del massiccio del gennargentu (sardegna centro-orientale), caratterizzata dalla presenza di altopiani carbonatici mesozoici, conosciuti con il nome locale di "tacchi" o "tònneri", che coprono in discordanza il penepiano paleozoico costituito da metarenarie e metasiltiti di età ordoviciano-cambriana. i tacchi sono il risultato di una complessa evoluzione geologica e derivano da un'unica ed estesa copertura carbonatica giurassica suddivisa in vari frammenti a seguito di movimenti epirogenetici plio-pleistocenici dai quali vennero fratturati, sollevati o abbassati e successivamente erosi e isolati da processi fluviali, gravitativi e meteorici. la paleogeografia e l'evoluzione di questi paesaggi possono essere spiegate in maniera eloquente osservando diversi geositi di questa regione, quali la gola di san giorgio, la grotta di su marmuri e il tacco di monte tisiddu che, collegati a rete possono creare un forte motivo di richiamo per un turismo naturalistico e culturale per questa regione dell'interno della sardegna. oltre a questi geositi il territorio contiene altri validi temi di interesse geologico e geomorfologico come la valle del riu pardu e i suoi villaggi abbandonati di gairo ed osini vecchio (parzialmente distrutti da frane avvenute nel xx secolo e soprattutto dopo le forti piogge nell'ottobre del 1951), diverse cascate temporanee e depositi di travertino o di terre rosse di decalcificazione e valli sospese che completano il richiamo verso questo paesaggio di per sé già ricco e vario. la presente ricerca ha come obiettivo la conservazione della geodiversità e delle molteplici valenze di questo territorio e si propone la valorizzazione dei geositi di maggiore interesse in linea con i principi dello sviluppo sostenibile. tale valorizzazione prevede la realizzazione, d'intesa con le autorità locali, di una rete locale di geositi connesso con il sistema dei monumenti naturali istituiti dalla legge regionale 31/1989, la costruzione di sentieri equipaggiati, l'elaborazione di cartografia tematica e pannelli esplicativi nei quali geologia, geomorfologia, paesaggio carsico, fauna, flora ed archeologia vengono illustrati in forma chiara ed accessibile secondo i criteri di una corretta divulgazione scientifica. in particolare alcuni di questi pannelli saranno focalizzati alla lettura del paesaggio nella quale gli aspetti geologici, geomorfologici ed ambientali collimino a delineare un modello evolutivo di notevole interesse per l'educazione ambientale e nello stesso tempo di grande suggestione dal punto di vista percettivo. la proposta di valorizzazione di tali geositi, raggruppati in una rete, è concepita per integrarsi con l'insieme dei beni geografico-fisici presenti nelle aree limitrofe. tutto questo potrà contribuire a fornire un servizio importante ai numerosi turisti che visitano le coste e che possono trovare nei paesaggi dei tacchi itinerari geotematici di grande interesse. keywords: tacchi, karst, jurassic, dolomitic limestones, geosites, ogliastra. parole chiave: tacchi, carso, giurese, calcari dolomitici, geositi, geoturismo, sardegna. il quaternario italian journal of quaternary sciences 18(1), 2005 volume speciale, 213-222 the area of ulassai and osini, in the central-eastern part of sardinia. the three chosen sites are the san giorgio gorge, the su marmuri show cave and the monte tisiddu taccu (fig. 1). aside the description of these geological monu1. introduction in this study, performed in the framework of the national project on geomorphological sites, the authors describe the three most important geosites of 214 j. de waele et al. fig. 1 site orientation. area di ricerca. ments the authors propose the conservation of the multiple valences present in the territory, comprising the valorisation of the sites of geological interest in line with the principles of a sustainable development, also through the realisation of a local network of geosites connected to the system of natural monuments instituted by the regional law 31/1989. this proposal of valorisation of these sites of geological and geomorphological interest, grouped in a local network, could well be applied to other areas ending up with the realisation of a regional system of geosites, and the authors hope that the regional and local stakeholders will, in the near future, participate in the correct geo-environmental management of their territory, giving an important service to the cultural education of the local people and to the many tourists that come and visit the tacchi area and the central-eastern coast of sardinia. 2. methodology geosites and geomorphosites have in some way been recognised as cultural heritage by the “convention of the protection of world’s culture and nature” signed by almost 160 countries and adopted by unesco during the general conference of paris in 1972. this convention gave also birth to the world heritage list of those sites that have “exceptional universal value” from a historical, artistic or scientific point of view. from the end of the 70’s beginning of the 80’s the first inventories of “naturalistic sites” are produced in italy. in this first phase, that can easily be defined preliminary, the study and the cataloguing of geological sites does not have well defined and univocal rules. in 1991 the first european meeting on geosites is held at digne-les-bains (france) during which the “declaration of rights of the earth’s memory” is presented. in the same occasion the methodology for the systematic survey of geological and geomorphological sites on a regional scale is also proposed by barca & di gregorio (1991) with the aim to assure a uniform study and evaluation of such sites. at this scope a file sheet is proposed that is subdivided in four sections: 1) identification, 2) main and integrative parameters of evaluation, 3) degree of scientific and historic-cultural importance, 4) state of use and tutelage. the file sheet is also characterised by the presence of an extract of topographical map and further information on the geographical location. the authors suggest to arrive at a objective way of survey that do not take too much into account the aesthetic criteria normally used in describing natural sites. contemporary casto et al. (1991) produce a type of sheet file used for the cataloguing of geosites and geomorphosites in the provinces of rome and rieti. this sheet file, even though containing a precise location of the described sites and containing also two new elements, such as photographs of the site useful to evaluate modification and or destruction, and a brief description, seems to be too subjective and too dependant on the surveyor (marchetti, 1999; poli, 2003). from the second half of the 90’s the studies and the methodologies continuously improved and also on a national level starts to form the idea of making a uniform methodology and to construct a sheet file based on the positive earlier experiences made in various italian regions. the new sheet files for identification and classification are conceived and realised in order to be inserted in gis systems, in the framework of regional, national and international projects for geosites census. since 1996 the international union of geological sciences (iugs) started the geosites research program in the framework of unesco (wimbledon, 1996). finally, in august 2001, during the ivth international conference of the international association of geomorphologists, the working group “geomorphological sites: research, assessment and improvement” has been instituted, taking experience from the italian national cofin project "geosites in the italian landscape: research, evaluation and valorisation". it is in the framework of all these activities that the term “geomorphosites” has been coined (panizza, 2001) and that new methodologies for cataloguing have been proposed (carton et al., 2003). a sheet file elaborated by the agency for the protection of the environment and territory (apat, former national geologica service) and by the centre for documentation of geosites of the university of genoa, still under experimentation, has been used in this paper. this sheet file is subdivided in fourteen sections further subdivided in sub-sections, and accompanied by a second socalled “specialistic” sheet file. the presence of sub-sections in most of the sections enhances the comprehension of the geosites giving a more detailed information. this new type of sheet file, a part of being the most recent and most developed one, is also the one the better satisfies the requirement both for the analysis and the input of geomorphosite data, and has also been adopted for the surveying of sites in sardinia. 3. geology of the tacchi region the tacchi area is a landscape unit located to the south of the gennargentu mountains in the central-eastern part of sardinia. this unit is mainly characterised by table-like carbonatic mesozoic plateaus, locally named "tacchi", overlaying with 215geosites and landscape ... an unconformity the palaeozoic basement constituted of middle cambrian-ordovician quartzitic-micaceous metasandstones, quartzites, quartzitic phyllites and metasiltstones (gennargentu formation) peneplained during permian-triassic (fig. 2). this long continental period is clearly identified by the local presence of ferruginous phyllites with limonite nodules generally named "ferro dei tacchi", in the past cultivated for the iron content (marini, 1984). the beginning of the jurassic succession is characterised by a more or less well preserved succession of continental fluvial, delta and lacustrine sediments composed of a quartzite conglomerate, sandy and clayey lenses and, in some places, containing lignite seams or clays with vegetal remains (barca & palmerini, 1973; fazzini et al., 1974). according to dieni & massari (1985) these sediments are comparable to the complete succession described at genna selole and attributed to bajocian-bathonian (genna selole formation). palynological studies of these sequences also suggest the age of the black clays with plant remains to be bajocian-bathonian (del rio, 1985). this continental fig. 2 stratigraphic column of the sedimentary sequence of the tacchi in central-east sardinia. colonna stratigrafica della sequenza sedimentaria dei tacchi nella sardegna centro-orientale. 216 j. de waele et al. fig. 3 geological and geomorphologica l map of the study area with the three geosites. carta geologica e geomorfologica dell'area di studio con i tre geositi. 217geosites and landscape ... 218 j. de waele et al. sequence is immediately followed by a marine succession of dolomitic limestones, in the lower part disposed in well stratified decimetric and metric beds and upwards becoming more massive, upon which are locally preserved about 30 meters of white coralline and oolithic limestones for a total thickness of over 300 meters. recently the lower dolomitic succession has been attributed to the dorgali formation, mostly of bathonian-callovian age, while the uppermost more calcareous part represents sediments of the monte tului and monte bardia formations of calloviankimmeridgian age (barca & costamagna, 2000, barca et al., 2000a; 2000b). this unique and widespread jurassic carbonatic cover emerged form the sea at the end of mesozoic and during tertiary the landscape started evolving with the formation of valleys with prevalent direction nne-ssw that eroded the surrounding palaeozoic mountains. these palaeo-valleys are still recognisable on top of many tacchi where large closed depressions contain remnants of fluvial deposits with metamorphic and quartzite elements (e.g. polje of san giorgio) and suspended valleys occur along the borders of the tacchi. towards the end of tertiary the fluvial erosion of the palaeozoic metamorphosed sediments, enhanced by the epirogenetic movements of the alpine orogeny, started cutting the dolomitic limestone plateau in several separated blocks along the major tectonic directions (nnw-sse, nne-ssw and e-w), causing an inversion of relief. from this period to now the individual tacchi started evolving separately and the karst features show slight differences even between neighbouring table-mountains. from a geomorphological point of view the tacchi of osini and ulassai are mainly characterised by multiple karstic forms such as sinkholes, dry valleys, larger depressions (macrodolines), caves, stone forests and other spectacular ruinl ike erosional karst ic forms; grykes, solution pans, karren and other minor karst phenomena are less developed (marini & ulzega, 1973; bianco & de waele, 1992; ardau & de waele, 1999; bartolo et al., 1999). the valleys that divide the tacchi, some of which have rapidly evolved since pliocene (ulzega & marini, 1977), are characterised by unstable flanks where landslides have repeatedly occurred in concomitance with heavy rainfalls (e.g. rio pardu) (maxia et al., 1973; ciccu et al., 1994; ginesu, 1999). 4. the geosites the most typical landform of the region is the so-called taccu or tonneri, table-like carbonatic mountain being the result of the geomorphologic processes that have changed the landscape since tertiary. these geomorphic testimonies constitute the remains of a continuous dolomitic limestone platform that covered most part of central-east sardinia, cut in many independent outcrops situated at varying heights by tectonic movements and erosion and forming a typical example of inversion of relief. at the basis and along the borders of these mountains, in some places, the jurassic transgression sediments of the genna selole formation can be observed and the traces of the ancient excavations for lignite can still be seen along the path that runs at the basis of tisiddu. on the contact of dolomitic limestones and palaeozoic basement many karst springs are situated, most of which are used for the orchards or for public fountains (ardau et al., 1993). in figure 3 a geological and geomorphological map of the region is given in which the three geosites are clearly reported. one of the most typical tacchi is monte tisiddu near ulassai; this carbonatic plateau, with a surface of about 1.5 km2 and walls of 50 to 100 m height, is controlled by the forestry department, and shows interesting and spectacular karstic landforms such as sinkholes, caves etc. (bianco & de waele, 1992) (fig. 4). there are only four pathways that allow to ascend the carbonatic plateau, while along almost the entire perimeter of tisiddu vertical walls form a natural inaccessible barrier. these ancient tracks can be followed by hikers and allow to make walks of scientific and didactic interest in a mostly uncontaminated nature and with diversified and unusual panorama's on the underlying riu pardu and riu ulassai valleys and on the villages of ulassai and jerzu. once on tisiddu the landfig. 4 monte tisiddu tacco: a panoramic view from bruncu cococcia towards the northwest: on the first plan to the left the vertical walls of bruncu casteddu (monte tisiddu) and in the background the other smaller tacchi of jerzu, all covering the palaeozoic basement profoundly incised by the tertiary and quaternary valleys (photo jo de waele). tacco di monte tisiddu: vista panoramica da bruncu cococcia verso nordovest; in primo piano sulla sinistra si vedono le pareti verticali di bruncu casteddu, mentre sullo sfondo si notano gli altri piccoli tacchi di jerzu, che coprono anch'essi il basamento paleozoico intensamente inciso da valli terziarie e quaternarie (foto jo de waele). scape is dominated by karstic landforms such as dolines, dry valleys, caves and karst pinnacles. from the highest top of the mountain (bruncu matzeu, 957 m a.s.l.) a spectacular and widespread view stretches from the tyrrhenian sea to the gennargentu mountains, while the nearby tacco of ulassai dominates the riu pardu valley. the river pardu flows along a nw-se alpine fault and deeply cuts the palaeozoic basement. this rapid deepening by erosion is related to the plio-quaternary uplifting of the whole area that also caused the capture of rio pardu approximately 3 km downstream of ulassai. this capture determines an abrupt change of direction from nw-se to ne-sw. the rapid geomorphologic evolution of the valley has caused mass movements, mainly along tension cracks, provoking a whole generation of quaternary landslides (ulzega & marini, 1977; arisci et al., 2000). the most impressive of these tension cracks is the san giorgio gorge, across which passes a road that connects the village of osini with the carbonatic high plateau rich in karst forms, interesting endemic flora and archaeological remains (fig. 5). the san giorgio gorge forms the natural gateway to the plains of the karstic tacco of ulassai and is one of the island's natural monuments instituted by the regional law n°31/1989. in this narrow gorge, wide only 8 m in some places for a height of 40 m, have been found archaeological remains of a roman settlement. some pathways lead up into the mountain to the eastern flank of this tension crack from where the panorama dominates the entire riu pardu valley with its abandoned villages of gairo and osini (partially destroyed by landslides during the xxth century and particularly after exceptional rainfalls in october 1951), the reconstructed new villages and ancient and recent landslides and rockfalls. a couple of hundreds of meters to the north, along the high dolomite walls of the taccu, a suspended valley testimonies an ancient late-tertiary hydrography. but the most important proof of an ancient drainage basin on the tacco is the enormous sinkhole and underground river passage of the su marmuri cave near ulassai, open to public from april to october and accounting for more than 20,000 visitors/year (fig. 6). the cave entrance is characterised by a collapse doline which has uncovered a very big natural tunnel. after a descent of almost 40 meters along a stairway constructed in the late 50's the cave passage becomes horizontal and is characterised by a angular development caused by the intersection of fractures along which the underground river has eroded forming this gigantic tunnel. the enormous natural underground river passage of su marmuri ends deep into the carbonatic plateau after 219geosites and landscape ... fig. 5 san giorgio gorge: spectacular view of the dolomite peak at the centre of the gorge, isolated by tension cracks, around which the tarmac road that connects the village of osini with the karstic plateau of tacco of ulàssai turns (photo jo de waele). la gola di san giorgio: vista spettacolare del picco dolomitico che si erge al centro della gola, isolato da tension cracks, attorno al quale gira la strada asfaltata che collega l'abitato di osini con l'altopiano carsico del tacco di ulàssai (foto jo de waele). a total length of almost 900 meters. in the median part of the cave the floor is constituted of thousands of rimstone pools (fig. 6), followed by a giant room with impressive flowstones, stalagmites and stalactites. close to the entrance lay two fresh-water lakes nearby which hibernate more than 10,000 bats (miniopteris schreibersi natt.) during winter. besides this colony of bats, among the greatest known on the island, the cave is very important for its cave dwelling fauna with rare endemic arthropods such as the beetle ovobathysciola gestroi fairmaire (the first troglobius animal discovered by raffaello gestro in sardinia at the end of the 19th century) and the chilopod lithobius doderoi silvestri, both of which are typical of the tacchi region (bartolo et al., 1983; de waele, 1996; bartolo et al., 1999). 220 fig. 6 plan of the su marmuri cave that takes its name from the characteristic concretioning (marble), with the environmental monitoring system proposed by ardau & de waele (1999) (survey by gruppo speleo-archeologico nino businco ulàssai). pianta della grotta di su marmuri con il sistema di monitoraggio proposto da ardau & de waele (1999): la grotta prende il nome dall'abbondante e massiccio concrezionamento. (rilievo dal gruppo speleo-archeologico nino businco ulàssai). j. de waele et al. 5. proposal of conservation and valorisation monte tisiddu, the gorge of san giorgio and the su marmuri cave constitute all together an extraordinary example of the tertiary-quaternary landscape evolution of the mesozoic carbonatic platform that characterise the central eastern part of sardinia: the first, with its dolines, the dry valleys and the karst pinnacles as a testimony of a well developed and mature surface karst; the second representing the tectonic and gravitational phenomena and correlated to the fragmentation of the borders of the forming carbonatic plateaus and the third emblematically testifying the underground karst evolution that started before the fragmentation of the emerged carbonate platform. to protect and to valorise these three geosites the authors propose the creation of a local network of geological monuments, connected to a regional system that was started with the institution of the regional natural monuments of the regional law 31/1989. for these purposes a program of detailed geological-stratigraphical and geomorphological survey has been foreseen that aims to put in evidence their intrinsic characteristics, essential for their appropriate valorisation and a management compatible with their effective carrying capacity, in particular for the su marmuri cave where a meteorological study will monitor the subterranean environment. after this phase, in collaboration with the local authorities, illustrative material will be prepared (booklets, cd rom, synthetic thematic maps, etc.) in order to document the elements of interest of these geological landscapes and geosites and, ultimately, a series of explicative panels, containing the educational information, and signals will be positioned to enable their correct utilisation. aside these init iatives, anyhow, for some of these geosites (monte tisiddu, gorge of san giorgio) it will be necessary to enforce the measures of protection of the territory and the landscape, and also the formation of local guides that are prepared to explain the interest and the importance of these sites and of the network of geomorphological sites in a regional and in a national context. acknowledgements this research has been performed in the framework of the national project cofin 2001-2003 "geositi nel paesaggio italiano" which local research group is co-ordinated by 221 fig. 7 su marmuri cave: "galleria delle vaschette"(passage of the gours) in the central part of the cave has developed along a nw-se fracture, is characterised by vertical and rectilinear walls widened by underground fluvial erosion processes, and its floor is at present completely covered with thousands of gours filled with water, some of which still contain cave pearls (photo gabriela pani). la grotta di su marmuri: "galleria delle vaschette", nella parte centrale della cavità è impostata su una frattura no-se e si caratterizza per le pareti rettilinee e verticali allargate da processi d'erosione fluviale. il pavimento è completamente ricoperto da migliaia di vaschette riempite d'acqua, alcune delle quali contengono perle di grotta (foto gabriela pani). geosites and landscape ... prof. antonio ulzega and prof. felice di gregorio of the university of cagliari. the authors would like to thank andré ozer and an anonymous referee for their useful comments and advice. references ardau f. & de waele j. (1999) geosites of the tacchi area (central-east sardinia, italy) in: d. barettino, m. vallejo & e. gallego (eds.), towards the balanced management and conservation of the geological heritage in the new millenium, madrid, pp. 87-93. ardau f., bianco l., de waele j. & vernier a. (1993) studio dell'idrogeologia e caratterizzazione idrochimica delle acque del tacco di ulàssai (sardegna centro-orientale) atti 3° congr. naz. dei giov. ric. di geol. appl., potenza 28-30 ottobre 1993, geologia applicata e idrogeologia, 27, pp. 27-34. arisci a., di gregorio f., follesa r. (2000) cartography in areas at risk: the example of the alluvial plain of the pelau river (central-east sardinia) – atti x congresso nazionale di geologia, roma 7-10 december 2000, pp. 535-544. barca s. & costamagna l.g. (2000) facies analysis of the "dorgali dolostone" formation (middle jurassic, central sardinia, italy): preliminary data convegno "evoluzione geologica e geodinamica dell’appennino" in memoria del prof. giampaolo pialli; perugia, 16-17-18 febbraio 2000, abstractbook, pp. 19-20. barca s. & di gregorio f. (1991) conservation et valorisation du patrimoine géologique de la sardaigne (italie): une proposition méthodologique 1er symposium international “protection du patrimoine géologique”, digne-les-bains, france. barca s. & palmerini v. (1973) indagine sedimentologica e significato paleoclimatico delle facies clastiche alla base dei "tacchi" suppl. rend. sem. fac. sci. univ. cagliari, 43, pp. 1-28. barca s., costamagna l.g., loddo r. & mazzarolo r. (2000a) evoluzione sedimentologico-stratigrafica della successione giurassica del "tacco" di seui (sardegna centrale) 80° congresso della s.g.i. riunione estiva trieste, 20-23/09/1998, riassunti, pp. 52-53. barca s., costamagna l.g., loddo r. & mazzarolo r. (2000b) prima segnalazione delle formazioni di monte tului e di monte bardia nell’area dei " tacchi" (sardegna centrale): caratteristiche sedimentologiche e conseguenze paleografiche 80° della s.g.i., r iunione estiva, trieste, 2023/09/1998, riassunti, pp. 54-55. bartolo g., coroneo m. & lecis a. (1983) su marmori guido bartolo editore, 53 pp. bartolo g., concu p., deidda d., de waele j., grafitti g. & salis t. (1999) taccu d'ogliastra ulàssaiosini-gairo-ussassài s'alvure editrice, oristano, 269 pp. bianco l. & de waele j. (1992) il monte tisiddu e il tacco di ulassai monografia di anthéo, bollettino del gruppo speleo-archeologico giovanni spano cagliari, 1, pp. 1-22. carton a., coratza p., marchetti m. (2003) – methodological proposal for mapping geomorphosites workshop proceedings “geomorphological sites: assessment and mapping”, pp. 21-22. casto l., poliziano c., zarlenga f. (1991) protezione ambientale: beni geologici energia e innovazione, 37 (1-2). ciccu r., manca p.p. & di gregorio f. (1994) propensione al dissesto idrogeologico in sardegna: analisi storica degli eventi ed aspetti metodologici atti iv conv. int. geoing. "difesa e valorizzazione del suolo e degli acquiferi", torino. de waele j. (1996) su marmuri quando la grandezza ha un nome, cagliari, 32pp. del rio m. (1985) palynology of middle jurassic black organic shale of "tacco di laconi", central sardinia, italy bollettino della società paleontologica italiana, 23 (2), pp. 325-342. dieni i. & massari f. (1985) mesozoic of eastern sardinia. in: a. cherchi (ed.), 19th european micropaleontological colloquium-guide book, agip sardinia, 1-10 october 1985, pp. 66-78. fazzini p., gasperi g. & gelmini r. (1974) ricerche sul verrucano 2. le successioni basali dei "tacchi" tra escalaplano e jerzu (sardegna sud-orientale) bollettino società geologica italiana, 93, pp. 221-243. ginesu s. (1999) aspetti del paesaggio fisico in un microcontinente poddighe (ed.), sassari, 164 pp. marchetti m. (1999) il censimento dei “beni geologici” in: g. poli (ed.), geositi, testimoni del tempo, regione emilia-romagna, servizio paesaggio, assessorato alla programmazione, ed. pendragon, bologna, pp. 69-87. marini c. (1984) le concentrazioni residuali post-erciniche di fe dell'ogliastra (sardegna orientale): contesto geologico e dati mineralogici rendiconti società italiana di mineralogia e petrologia, 39 (1), pp. 229-238. marini a. & ulzega a. (1973) osservazioni geomorfologiche sul tacco di ulassai rendiconti seminario facoltà scienze università di cagliari, 47 (12), pp. 192-208. maxia c., ulzega a. & marini c. (1973) studio idrogeologico dei 83 dissesti nel bacino del rio pardu (sardegna centro-orientale) pubblicazione dell'istituto di geologia, paleontologia e geografia fisica, 121(12), 9 pp. poli g. (2003) dalla stanza delle meraviglie alle meraviglie della terra in: s. piacente & g. poli (eds.), la memoria della terra. la terra della memoria, l’inchiostro blu ed., bologna, pp. 28-40. ulzega a., marini a. (1977) l’évolution des versants dans la valée de rio pardu. zeitschrift fur geomorphologie n.f., 21 (4), pp. 466-474. wimbledon w.a.p. (1996) geosites a new conservation initiative episodes, 19, pp. 87-88. 222 j. de waele et al. imp.reynard geomorphological sites, public policies and property rights. conceptualization and examples from switzerland emmanuel reynard institute of geography, university of lausanne, bfsh 2 – dorigny, ch – 1015 lausanne emmanuel.reynard@unil.ch abstract: e. reynard, geomorphological sites, public policies and property rights. conceptualization and examples from switzerland. (it issn 0394-3356, 2005). the paper analyses the importance of institutional rules for protecting and managing geomorphological sites. a framework, called institutional resource regime (irr), is proposed. it considers a natural resource, and more specifically geomorphological sites, in a systemic manner, and combines the analysis of the property rights concerning the resource and the public policies regulating its exploitation and protection. two examples are presented in order to illustrate the analytical possibilities offered by the irr concept and the necessity to develop specific and adequate institutional tools in order to guarantee efficient protection of geomorphological sites. riassunto: e. reynard, siti geomorfologici, politiche pubbliche e diritti di proprietà. analisi ed esempi in svizzera. (it issn 03943356, 2005). l’articolo mette in evidenza l’importanza di sviluppare regole istituzionali che permettano di proteggere e gestire i siti geomorfologici in modo adeguato. viene proposto un quadro analitico chiamato regime istituzionale di risorse (rir), che considera una risorsa naturale, e più particolarmente i siti geomorfologici, in un modo sistemico e combina l’analisi dei diritti di proprietà concernenti la risorsa e delle politiche pubbliche che regolano tale risorsa. due esempi illustrano le possibilità analitiche offerte dal concetto rir e dimostrano la necessità di sviluppare strumenti istituzionali adeguati per garantire una protezione efficace dei siti geomorfologici. keywords: geomorphological sites, protection, public policies, property rights, institutional resource regime. parole chiave: beni geomorfologici, protezione, politiche pubbliche, diritti di proprietà. il quaternario italian journal of quaternary sciences 18(1), 2005 volume speciale, 323-332 1. introduction geomorphological sites (or geomorphological assets) are defined as geomorphological landforms (and processes) that have acquired a scientific, cultural/historical, aesthetic and/or social/economic value due to human perception or exploitation (panizza & piacente, 1993; quaranta, 1993). more precisely, they have a particular importance for reconstructing, explaining and recording the history of earth, its climate and all the life it supports (grandgirard, 1997). they can be single geomorphological objects (e.g. waterfall, inselberg, erratic block, dune, etc.) or larger landscapes (e.g. glacier forefields, marine coasts, alluvial fans, etc.). the value of a site can be of four types (panizza & piacente, 1993, 2003; quaranta, 1993): scientific (e.g. a moraine representative of a glacier extension, an artificial trench allowing observation of a transition in a sediment succession), cultural/historical (e.g. a mountain that has religious or mystic value or a landform/landscape that is a support for cultural/historical activities or infrastructures), aesthetic (e.g. some amazing mountainous, coastal or desert landscapes), and social/economic (e.g. aesthetic landscapes as tourist destinations). as indicated by cavallin et al. (1994), geomorphological sites may be modified, damaged, and even destroyed, by direct or indirect impacts of human activity. direct impacts are defined as active modifications of a geomorphological site by human activity (e.g. destruction of a morainic crest by road construction, modification of the aesthetic value of a coastal environment by the building of a tourist settlement), whereas indirect impacts do not have direct contact with the geomorphological site but highly affect it (e.g. sedimentation changes in an alluvial fan by gravel extraction upstream, reduction of the view of a geomorphological asset by the construction of buildings). due to their vulnerability, most geomorphological sites need to be protected against direct and indirect human impacts. the first step in a protection process is to assess the value of geomorphological sites (panizza & piacente, 1993, 2003; panizza et al., 1995a; grandgirard 1999a). numerous more or less quantitative methods have been proposed for evaluating the quality of geomorphological sites (quaranta, 1993; panizza et al., 1995b; rivas et al., 1997; boyer et al., 1998; grandgirard, 1999a; coratza & giusti, 2003), especially in the context of environmental impact assessment (eia) procedures. proposals have also been made for conducting inventories of geomorphological sites at a regional scale (grandgirard, 1999b). the objective of this paper is to discuss the second step of a procedure for the protection of geomorphological sites, that is, the implementation of rules (restrictions of use, bans, access regulation, management of the material extraction, etc.), aiming to regulate the “exploitation” of geomorphological sites. the third 324 e. reynard step should be to assess the effects of the regulation on the quality of the sites and on the sustainability of their management. i will use the institutional resource regime (irr) concept, a framework that was developed for analysing the quality of natural resource management from an institutional point of view (kissling-näf & varone, 2000; knoepfel et al., 2001), and that we consider useful for developing strategies for the protection of geomorphological sites (reynard, 2002). we will first describe the relationships between geomorphological sites and natural resources. then, the irr concept will be presented and applied to the geomorphological sites analysis. two swiss examples demonstrating the interest of the irr concept in the area of geomorphological site protection, will finally be presented. 2. geomorphological sites as natural resources as geomorphological sites are in contact with human activities, and because they are exploited, even from an immaterial point of view (e.g. the observation of a landscape dominated by geomorphological landforms), they may be considered as natural resources. we define a natural resource as the part of the natural environment used by humans for satisfying their needs (siebert, 1983). in this anthropologically centered definition, natural resources are culturally defined (grima & berkes, 1989); nature becomes a natural resource only when humans give it a value. in this sense, as an example, gas and oil were not natural resources for the north american indians of 1800 (grima & berkes, 1989). in every process of resource exploitation, the stock of the resource and the yield are distinguished (ostrom, 1990). the stock is the amount of resource that is naturally renewed in the case of a renewable natural resources (e.g. underground water that is renewed every year by the hydrological cycle) or that is not renewed in the case of non-renewable resources (e.g. oil, gas). the yield is the product of the stock. in the case of water, for example, the stock is the quantity of water involved in the natural water cycle of a watershed. the yield is the amount of water that is available to humans for satisfying their needs for consumption, irrigation, industrial production, etc. when the total amount of water uses is higher than the yield, there is overexploitation. from an economic point of view, natural resources are considered in order to create goods and services for society (grima & berkes, 1989). goods and services are produced either by the stock or the yield (fig. 1). in the case of forests, the wood is a good produced by the yield in a situation of sustainable exploitation, and by the stock in a situation of overexploitation. the space for recreation and the protection of infrastructures against natural hazards (avalanches, debris flows) are services produced by the stock and the yield. the production of biodiversity is a good and a service produced by the stock and the yield. the goods and services are used by humans in three different ways (knoepfel et al., 2001): direct uses (e.g. direct consumption, input in the industrial production), indirect uses (e.g. air and water as receptacle for the absorption of waste), and immaterial uses (e.g. aesthetic or cultural value of a landscape). from a geomorphological point of view, rivas et al. (1997) distinguish consumable and non-consumable geomorphological resources: consumable resources are those used for construction and other material extraction, whereas non-consumable resources include all the geomorphological elements that do not imply the direct extraction and consumption of material. the authors also include in that category landforms as part of the landscape, the sites of geomorphological interest from a scientific, pedagogic and recreational point of view, and geomorphological units as support for other elements of the environment, especially ecosystems. they add that geomorphological processes may represent natural hazards and contribute to environmental change (see also cavallin et al., 1994). extraction may be considered to produce goods (fig. 2) coming either from the stock (e.g. extraction of gravels from alluvial terraces) or from the yield (e.g. extraction of gravels directly from a river bed or active deltaic fan). we can also consider that geomorphological (or geological) processes may be, under certain conditions, a type of natural resource (e.g. fluvial flow used for energy production, volcanic eruption and geysers as tourist resource for regions like hawai or iceland, geomorphological features as support for specific human activities like canyoning, etc.). on the other hand, not all the geomorphological resources are to be considered as geomorphological sites. finally, we can consider that geomorphological assets are part of the landscape resource of a region. as well as for other natural resources, there is increasing competition for geomorphological sites between various users or user groups that have quite different, and sometimes contradictory, interests and perceptions of the value of the resource. such rivalries may be mitigated by defining regulations and institutions, whose objectives should be the co-ordination between rival uses in order to avoid conflicts, the planfig. 1 stock and yield in relation with goods and services produced by a renewable natural resource. ammontare (stock) e prodotti rinnovabili (yield) in relazione ai beni e servizi prodotti da una risorsa naturale rinnovabile. ning of long-term resource management and the preservation of the resource stock in order to be able to satisfy the needs of future generations (fig. 3). i propose to use the institutional resource regime (irr) framework developed by kissling-näf & varone (2000) and knoepfel et al. (2001) as the analysis method. 325geomorphological sites, public policies ... 3. institutional resource regime (irr) the irr concept considers all the uses of a natural resource as a whole. a renewable natural resource is generally exploited by more than one type of users. forests, for example, are used for various kinds of wood exploitation (e.g. fire, construction), other material exploitation (e.g. mushrooms), protection (e.g. against rockslides and avalanches), leisure (e.g. walking) and biodiversity conservation. management of such highly heterogeneous resource use systems needs efficient institutional regulations; sustainability of resource management is supposed to depend on the institutional framework. the irr concept allows the analysis of all the components of these institutional conditions. an institutional resource regime (fig. 4) is defined as the combination of the property regime and public policies that regulate the natural resource management (knoepfel et al., 2001). the property regime is analysed through three types of property rights (formal property titles (ownership), disposition rights and use rights) and two categories of public policies are considered: exploitation and protection policies. four types of ownership have been defined (e.g. ostrom, 1990; bromley, 1991; devlin & grafton, 1998): private property, state property, common property, and no property (tab. 1). two complementary dimensions are also considered: the extent and the coherence. the extent describes the number of goods and services explicitly regulated by the irr. the coherence concerns the degree of co-ordination of the actors’ network, mainly the co-ordination between the owners and the actors involved in the implementation of public policies. the irr are then classified into four regime types: no regime, simple regime, complex regime and integrated regime, by combining the extent and the coherence (kissling-näf & varone, 2000 and tab. 2). we speak of a "no regime situation", in cases where neither ownership, disposition, use rights, nor public policies exist. chances are, in this instance, that a resource has not yet been discovered. this was the case for biodiversity until recently; it is certainly the case for geodiversity, a resource that has not been defined precisely until now. if the use rights are formulated either directly and/or at least indirectly through an init ial policy design (e.g. bans, limitation of access), this can be referred to as a “simple regime”. we suspect that this kind of simple regime emerges when the central actors observe rivalry and scarcity in connection with the predominantly fig. 2 examples of goods and services produced by geomorphological processes and landforms. esempi di beni e servizi prodotti da processi e forme geomorfologiche. fig. 3 conceptual model describing the relationships between institutions, actors and natural resources (from kissling-näf & varone, 2000, modified). modello concettuale che mette in evidenza le relazioni fra istituzioni, attori e risorsa naturale (da kissling-näf & varone, 2000, modificato). fig. 4 components of an institutional resource regime. componenti di un regime istituzionale di risorse. 326 homogenous use of one or several goods or services provided by a given resource and this becomes a collective problem because of the risk of overuse. in most countries, geosites and landscapes in general could be considered to be in this situation: there is a problem of management, but few regulations have been produced until now. in a “complex situation”, we can already observe differentiation on the basis of the specific uses of the resource (goods and services provided by the resource) and the combining of the formal ownership, disposition and use rights with more detailed public policies. the heterogeneous demands and the sum of the diverse use rights could lead to a crisis and possibly even the collapse of the complex regime. examples of such competing and excessive uses can be found in the area of land (e.g. agriculture, construction zones, roads and railways, etc.), water (e.g. fishing, energy, agriculture, drinking water, etc.) and forest (e.g. biodiversity, recreation, timber, etc.). an institutional regime which can take into account the heterogeneous demands and regulate the totality of the uses in order to maintain the capacity of the renewability of the resource is considered as an “integrated regime”. we assume that such a regime may promote sustainability, that is to guarantee the transparent satisfaction of the heterogeneous use requirements and to conserve the resource stock. the analysis of the institutional regime of a resource is carried out in five successive steps (reynard, 2002). first, the resource perimeter is defined and a compilation of the various goods and services provided by the resource is made in order to represent the main current rivalries, the historical evolution of the relationships between goods and services, and the principal transformations of the resource stock and yield. this part of the analysis concerns essentially the resource and its characteristics. then, the property regime (formal ownership, disposition rights and use rights) and the public policies related to the resource exploitation and protection are successively analysed. the first three steps are then combined to characterise the resource regime. it is assumed that simple or integrated regimes are more sustainable than complex regimes. the last step is dedicated to the improvement (if necessary) of the resource regime in order to improve sustainability. thus, the systemic irr analysis is assumed to allow a rational selection of management instruments. 4. geomorphological sites and institutional resource regimes if we consider the management of geomorphological sites in a systemic manner, the irr appears to be an adequate tool for analysing the various uses of geomorphological sites by humans and for improving management mechanisms. in this section, we successively analyse what the goods and services provided by a geomorphological site are, and in which way property rights and public policies are important tools for managing geomorphological sites. the principal goods and services produced by geomorphological sites are presented in table 3. thirteen types of uses are proposed, following the typology proposed by bisang et al. (2000) for the resource “landscape”. these uses are grouped in three large categories of geomorphological sites: a) natural heritage (support for life and earth science heritage), b) cultural heritage (cultural, symbolic, religious, pedagogic value), and c) objects for economic uses (support and spaces for tourist and other economic uses). in most cases, a geomorphological site combines several values coming from the three categories. for example, the famous uluru (ayers rock) in central australia (fig. 5), combines the following goods and services. as it is a characteristic example of an inselberg, it has a geomorphological value (twidale, 1978). e. reynard tab. 1 classification of property rights (from knoepfel et al., 2001, modified). classificazione dei diritti di proprietà (da knoepfel et al., 2001, modificato). private state common no property property property property open access owner of the people, state: local associations, nobody property title private municipalities, corporations societies region, state, etc. exclusion yes yes yes no example soil, forests national parks alpine meadows air, landscape tab. 2 classification of resource institutional regimes (from kissling-näf & varone, 2000). classificazione dei regimi istituzionali di risorse (da kissling-näf & varone, 2000). institutional resource regime (irr) coherence of the actors within the public policies and the property rights system high low range of regulated goods and high integrated regime complex regime services (derived from the low simple regime no regimeresource) fig. 5 uluru (ayers rock), an australian geomorphological site with several rival uses. uluru (ayers rock), un geomorfosito australiano con parecchi usi possibili, tra loro contrastanti. 327 the vertically stratified sandstones testify the existence of an ancient delta that was removed by tectonic movements (earth history value). the taffonis that can be shown at its surface give evidence of climate change (climate history reconstruction). the rock and its surroundings provide habitat for specific fauna and flora (ecological value). it also has an aesthetic, and in this case we could also add a “photogenic”, value as impressive landscape, because of its varying appearance with the changes in light (sunrise and sunshine). uluru also has a religious and symbolic value for the aborigines; it was also used as one of the symbols for the political actions of the aborigines for recovering the sovereignty over their land. because of its high earth science value, it also has pedagogic value for students, scientists and tourists. this impressive and unique landscape is the basis for very fruitful tourist exploitation, with rapid development of derived offers (camping, hostels, sunshine and sunrise observation places, guided visits, cultural aborigine centre, etc.) around the original offer (landscape) (for an analysis of the distinction between original and derived tourist offer in the domain of geomorphology, see pralong & reynard, 2005) the area has provoked major impacts either on the natural values of the rock and its surroundings (ecological and geomorphological processes) or on the aborigine culture (e.g. climbing on the rock, which is “forbidden” by the aborigine religion). these rivalries are mitigated either by property rights instruments (e.g. limited access to some religious and ecologically fragile sites), or by public policies (e.g. 1990s amendments of the australian legislation that gave aborigines new sovereignty over their land, creation of a national park). new instruments (e.g. forbidden access to the top of the rock) would certainly improve the co-ordination between the tourist industry, cultural, ecological and geomorphological protection in the area. in order to develop sustainable management of geomorphological sites, public policies ... tab. 3 goods and services provided by geomorphological sites (from reynard, 2002, modified). beni e servizi prodotti da siti geomorfologici (da reynard, 2002, modificato). category of use type of use principal users examples a) natural heritage life support all living beings volcanoes (that support a large range (humans, animals, plants) of human settlements) biodiversity heritage humanity, future generations, deltas or alluvial plains (that are often scientists, tourists environments with high vegetal and animal biodiversity) earth history heritage humanity, future generations, moraines or erratic blocks (that testify scientists, tourists former glacial extents) b) cultural heritage support for cultural humanity, future generations, isolated mounts, locks (that are often heritage scientists, tourists occupied by castles and fortresses) aesthetic heritage painters, photographs, impressive landscapes tourists space for cultural local population large natural regions (e.g. the alps, and religious islands), religious monuments identification (e.g. uluru for australian aborigines) space for political local population, saharan landscapes for the tuaregs identification politicians, state pedagogic sites schools, environmental cross-sections in sediment deposits, organisations, scientists sites where active processes are visible c) economic landscape with tourists, tourist industry, impressive landscapes (e.g. ayers rock, exploitation tourist/leisure local population grand canyon, matterhorn) valorisation framework for tourists, tourist industry, coasts (for bathing), mountains tourist/leisure local population (for hiking or skiing) activities support for specific tourists, tourist industry, cliffs (for climbing), reefs (for diving), rivers tourist/leisure local population (for canyoning) activities other economic industry, agriculture glacial locks (that are often sites for dam uses building), specific agriculture in sinkholes in the french causses, gravel extraction in braided rivers support for transport state, industry valleys (used for road or rail tracks construction), mounts (for building antennae) 328 geomorphological sites, the three dimensions (natural, cultural/social, and economic needs) should be taken into account. in this specific case, all three categories of uses and their respective relationships have been considered. this example also shows that rivalries and potential conflicts may be mitigated by creating and organising property rights and/or by developing public policies. table 4 summarises the various possibilities of regulating the sites’ management by using property instruments. the management, and especially the protection, of geomorphological sites largely depends on the public policies regulating the environmental protection and the resource exploitation of a country. restrictive policies concerning the resource exploitation (hydropower production, mining, territorial planning, etc.) are generally beneficial for the protection of geomorphological sites. moreover, explicit mention of the protection of geomorphological sites in the environmental policies is better than more general environmental protection policies. accurate analysis of public policies is therefore essential for guaranteeing effective protection of geomorphological sites and co-ordination with other human activities. in contrast with other european countries, like great britain, that has adopted a specific law for the protection of geological heritage, switzerland does not have a particular legislation for the protection of geological or geomorphological sites (jordan, 1999). until the adoption of the nature protection act in 1966, the geological heritage could only be protected by the private right (swiss civil code of 1912, article 724). in contrast with biotopes, that are explicitly protected, the nature protection act has no specific article aiming at the protection of geosites, even if the protection of the geological particularities is mentioned as one of the objectives of the law. the nature protection act introduced a new instrument: the inventory, which is a list of objects worthy of conservation. since, several inventories have been established by the federal government, some of them with partial reference to geosite conservation. that is the case of the natural and cultural landscapes inventory (1977), the moor landscapes inventory (1996), or the proglacial margins and alpine alluvial zones inventory (2001). none of these inventories are specifically dedicated to a geosite listing and the degree of protection varies greatly from one inventory to another. an unofficial geosite inventory has been produced by a group of experts under the auspice of the swiss academy of science (sas, 1999): the inventory, which lists 401 sites, has no legal incentive for the political authorities. a second group of experts has since produced a report on the opportunity of an official geosite inventory to be carried out by the federal e. reynard tab. 4 categories and swiss examples of property rights relating to geomorphological sites. categorie ed esempi svizzeri di diritti di proprietà concernenti siti geomorfologici. private state common non property property property property (open access) formal property geomorphological geomorphological geomorphological geomorphological rights site bought by an site managed by a site localised in a site localised in (ownership) environmental national park commonly owned alpine elevated non organisation administration space and managed by productive terrains the communal association (normally owned by example: swiss rock glaciers and the state but erratic blocks bought other landforms tortin morainic system considered or received as a gift included in the (valais, switzerland), as res nullius) by scientific swiss national type-locality for the egesen associations park (chaix, 1943) glacial stage in the western periglacial and (19th century) alps, property of a local glacial landforms (bachmann, 1999) corporation (kuonen, 1992) of the tourist area of verbier (lambiel & reynard, 2003) disposition servitude to an state decree for ? -rights environmental classifying a organisation geosite servitude to the classification of sites environmental ngo of interest by the pronatura for 100 years cantons or the on the alpine area of federal state la pierreuse (gentizon, 2004) use rights fee for visiting the restrictions for ? -caves of the hölloch visiting the swiss system national park (canton schwyz) government (gerber & gsteiger, 2000); such an inventory is not a political priority for the moment. at a lower political level, on the other hand, several cantons and some communes have carried out geosite inventories (jordan, 1999). the canton governments also have the possibility of protecting sites of interest by decree. another way of protecting geosites in switzerland refers to the territorial planning act (1979), whose article 17 allows the creation of protection zones for sites with high landscape and/or natural value (stürm, 1994; strasser et al., 1995; jordan, 1999). the recent modification of the forest act (1991) allows the long-term protection of sites discovered by engineering works (strasser et al., 1995). until now, reforestation after the end of the works was obligatory, a situation that could be in opposition with geosite conservation policy. some sites are also integrated in international lists of valuable sites, like the aletsch-jungfrau region in the unesco world heritage list or the entlebuch region in the unesco biosphere reserve list. some regions, like the glarnerland-sarganserland area, are also hoping to obtain the “geopark” unesco label. this rapid overview shows how the protection of geomorphological sites by public policies may be complex and highly dependent on the sensitivity of political authorities to the protection of the geological heritage. this latter is perceived more as pure support for the development of economic activities than a dynamic component of the environment to be protected and managed with accuracy, as well as the biotic environment. the following section is dedicated to the presentation of two cases. the first case, concerning the protection of erratic blocks in the central plateau of switzerland, illustrates the protection through property rights instruments; the second example is about the karstic area of tsanfleuron (valais) and shows the difficulty of protecting the geomorphological heritage in the absence of a specific protection policy. 5. two cases in switzerland the first example refers to the protection of erratic blocks in the central plateau of switzerland (favre, 1989; aubert, 1989; bachmann, 1999). these blocks were one of the indices that allowed the development of the glacial theory by scientists like ignaz venetz, jean de charpentier and louis agassiz at the beginning of the 19th century (schaer, 2000). they therefore have either a paleoclimatic (as landforms allowing the reconstruction of former extensions of alpine glaciers) or a geohistorical value (as objects at the origin of the development of a scientific theory). during the 19th century, they were intensively exploited as construction material, because of their specific petrography (mainly granites). that exploitation represented an interesting financial income for their owners, who were public bodies (communes) as well as private proprietors. therefore, there was clearly a rivalry between two competitive uses: the exploitation as construction material and the protection as heritage of the climate history and testimony of the geoscience history. in absence of a specific public policy for the nature protection, the only way for protecting the blocks was to buy or acquire them as gifts from communes or private owners. that is for example the case of several blocks situated in the canton of vaud (aubert, 1989) or neuchâtel, that were acquired by the local sections of the helvetic society of natural sciences (now swiss academy of science) or by the state. one of these blocks is the pierre des marmettes (fig. 6), a 1824 cubic metres block, situated on a last glacial moraine of the rhone glacier, near monthey in the canton of valais. in 1905, the block was to be exploited for granite extraction. because of its height and its high value for geological sciences, the project of exploitation provoked a large reaction both among the public and in scientific circles (schardt, 1908). in 1908, the helvetic society of natural sciences were able to acquire it for 31’500 swiss francs, subscribed by the confederation, the canton of valais, various societies and the public (aubert, 1989). after several decades, in 1983, it was included in the natural and cultural landscapes inventory. in 1999, the block was also proposed for the unofficial geosite inventory of the swiss academy of sciences (sas, 1999). 329geomorphological sites, public policies ... fig. 6 the pierre des marmettes (monthey, switzerland): an erratic block property of the swiss academy of sciences since 1908 (photography: j.p. pralong). la pierre des marmettes (monthey, svizzera): un blocco erratico proprietà dell’accademia svizzera delle scienze naturali sin dal 1908 (fotografia: j.p. pralong). the second example concerns the karstic area of tsanfleuron in the diablerets range (western switzerland). the zone has a high geomorphological value because of the presence of specific landforms and processes typical of a karstic plateau recently deglaciated, and the high sensitivity of the tsanfleuron glacier to climate variations (reynard et al., 2003). since the 1960s, the area has developed either intensive winter tourism (skiing) or more extensive summer tourism (hiking). because of the absence of a specific geosite protection policy, geomorphology was highly modified by road and infrastructure building. the main impact was the construction of a road aiming to mitigate the sharp topography of the superficial karst and to facilitate the preparation of ski runs (fig. 7). the material used for the road construction was extracted from a little ice age morainic crest. the works were performed without any authorisation and testify the absence of geomorphological sensitivity of the local authorities (reynard et al., 2003). because of opposition, the works were finally stopped by the cantonal administration and an environmental impact assessment (eia) was performed a posteriori. the eia recommended the dismantling of the road and the recovering of the morainic crest, which was carried out in autumn 2002. the landscape value of the moraine is therefore reconstructed, even if the sedimentological characters of the deposits are not the original ones. this example shows the difficulties associated with protecting the scientific and geohistoric value of gemorphological sites in a situation where there is an absence of specific geosite conservation legislation. without other more biological values (e.g. presence of biotopes, fragile ecosystems, etc.), geomorphological sites present a high vulnerability, principally because of the low sensitivity of the political authorities and the public in general for the geoscientific value and for the “beauty” of mineral landscapes. 6. conclusions the aim of this paper was to point out the importance of crafting adequate institutional rules in order to protect and manage geomorphological sites. once a gemorphological site has been assessed and its value has been shown, measures have to be taken in order to protect the site against negative human impacts. this protection is always developed within a specific institutional framework, which combines property rights as well as public policy aspects. the institutional resource regime (irr) concept allows the management of natural resources to be analysed in a systemic way. the analysed resource is considered to produce goods and services that are exploited by the society; when the uses are numerous and heterogeneous, situations of rivalry between different groups of actors are not uncommon, and institutional rules have to be developed in order to avoid conflicts. rules are developed following two different (but often combined) paths: the public policy and the property right paths. as geomorphological sites protection is poorly developed in most countries and vulnerability of these sites is principally due to the fact that they often combine several conflicting values, the irr concept seems to be an adequate tool for analysing firstly the various rival uses of geomorphological sites, and then secondly, the possible ways of protecting the sites and co-ordinating their uses. thirteen generic types of geomorphological sites uses have been shown and classified in three main categories: natural heritage, cultural heritage, and basis for economic exploitation. the example of uluru (australia) has shown how these types of heterogeneous uses often combine on a particular site and necessitate the adoption of institutional rules for avoiding conflicts. one possible way is to create specific property and use rights, in order to restrict access, for example. the other way is to develop public protection policies that allow the legal protection of sites of interest. the presentation of the development of public policy instruments in switzerland has shown that a specific protection of geosites is not common, mainly because of the absence of political sensitivity for mineral environments, which are considered much more as a support for economic development, than objects and areas with high specific natural value. the example of protection of erratic blocks in switzerland demonstrates how property rights tools may be of high interest for the geomorphological sites protection, for example the purchase of objects or areas by scientific or nature protection associations. on the other hand, the case of tsanfleuron has shown the difficulties of protecting highly valuable sites in the absence of specific policy instruments. the irr approach has not yet been applied systematically at a local or a regional level. the method should now be used for example in a region where a geomorphological sites inventory has been performed, in order to analyse the different uses of the sites of interest, to evaluate their vulnerability and to show the degree of institutional protection and the possible ways of improving it. acknowledgements this research was partly supported by the swiss national science foundation (project: comparative analysis of the formation and outcomes of resource regimes in switzerland, nr. 1214-055890.98.1, codirected by p. knoepfel, i. kissling-näf and f. varone). i strongly acknowledge my colleagues of that project and first of all s. nahrath for his useful comments, as well as the helpful criticisms of f. zarlenga and m. marchetti. 330 e. reynard fig. 7an illegal road built on the karst of tsanfleuron (valais, switzerland) by extracting gravels from a little ice age morainic crest. the road is now dismantled and the moraine recovered after an eia performed a posteriori. strada abusiva costruita nella zona carsica di tsanfleuron (vallese, svizzera) utilizzando ghiaia estratta da una morena della piccola età glaciale. la strada è stata smantellata e la morena ripristinata dopo una procedura di valutazione di impatto ambientale eseguita a posteriori. references aubert d. (1989) la protection des blocs erratiques dans le canton de vaud bull. soc. vaud. sc. nat., 79 (3), pp. 185-207. bachmann s. (1999) zwischen patriotismus und wissenschaft. die schweizerischen naturschutzpioniere (1900-1938) zürich, chronos verlag. bisang k., nahrath s. & thorens a. (2000) screening historique des régimes institutionnels de la ressource paysage (1870-2000) lausanne, working paper de l’idheap. boyer l., fierz s. & monbaron m. (1998) geomorphological heritage evaluation in karstic terrains: a methodological approach based on multicriteria analysis suppl. di geogr. fisica e dinam. quat., 3 (4), pp. 103-113. bromley d.w. (1991) environment and economy. property rights and public policy oxford, blackwell. cavallin a., marchetti m., panizza m. & soldati m. (1994) the role of geomorphology in environmental impact assessment geomorphology, 9, pp. 143-153. chaix l. (1943) les coulées de blocs du parc national suisse le globe, 82, pp. 121-128. coratza p. & giusti c. (2003) proposta metodologica per la valutazione dell'impatto sulla qualità scientifica dei geomorfositi in: s. piacente & g. poli (eds.), la memoria della terra, la terra della memoria, bologna, università degli studi di modena e reggio emilia / regione emiliaromagna / edizioni l'inchiostroblu, pp. 110-113. devlin r.a. & grafton q.r. (1998) economic rights and environmental wrongs. property rights for the common good cheltenham, elgar. favre a. (1876) notice sur la conservation des blocs erratiques et sur les anciens glaciers du revers septentrional des alpes suisses archives des sciences, 57, pp. 181-205. gentizon c. (2004) méthode d’évaluation des réserves naturelles en suisse: les cas de la pierreuse et des grangettes université de lausanne, thèse de doctorat. gerber b. & gsteiger p. (2000) konzept für den schutz der geotope von nationaler bedeutung bern, bundesamt für umwelt, wald und landschaft (buwal) und arbeitsgruppe geotope buwal/lhg, unpublished report. grandgirard v. (1997) géomorphologie et gestion du patrimoine naturel. la mémoire de la terre est notre mémoire geogr. helv., 52 (2), pp. 47-56. grandgirard v. (1999a) l’évaluation des géotopes geol. insubr., 4 (1), pp. 59-66. grandgirard v. (1999b) an inventory of geomorphological geotopes in the canton of fribourg (switzerland) mem. descr. carta geol. d’it., 65, pp. 273-278. grima l. & berkes f. (1989) natural resources: access, rights-to-use and management in: f. berkes (ed.), common property resources. ecology and community-based sustainable development, london, belhaven, pp. 33-54. jordan p. (1999) die geotopschutz: die rechtliche situation in der schweiz geol. insubr., 4 (1), pp. 55-58. kissling-näf i. & varone f. (2000) institutionelle ressourcenregime als innovativer steurungsansatz in: i. kissling-näf & f. varone (eds.), institutionen für eine nachhaltige ressourcennutzung. innovative steuerungsansätze, chur, rüegger, pp. 227-252. knoepfel p., kissling-näf i. & varone f. (eds) (2001) institutionelle regime für natürliche ressourcen: boden, wasser und wald im vergleich basel/genf/münchen, helbing & lichtenhahn. kuonen t. (1992) les pâturages de la région de sion du moyen-age à nos jours vallesia, 67, pp. 63229. lambiel c. & reynard e. (2003) impacts du développement d’un domaine skiable sur la morphologie glaciaire et périglaciaire : le cas de verbier (valais, suisse) in: e. reynard, c. holzmann, d. guex & n. summermatter (eds.), géomorphologie et tourisme, lausanne, institut de géographie, travaux et recherches, 24, pp. 19-33. ostrom e. (1990) governing the commons: the evolution of institutions for collective action cambridge, cambridge university press. panizza m. & piacente s. (1993) geomorphological assets evaluation zeitschr. für geomorphologie n.f., suppl. bd., 87, pp. 13-18. panizza m. & piacente s. (2003) geomorfologia culturale bologna, pitagora editrice. panizza m., fabbri a.g., marchetti m. & patrono a. (eds.) (1995a) geomorphologic analysis and evaluation in environmental impact assessment enschede, itc publication, 32. panizza m., marchetti m. & patrono a. (1995b) a proposal for a simplified method for assessing impacts on landforms in: m. panizza, a.g. fabbri, m. marchetti & a. patrono (eds.), geomorphologic analysis and evaluation in environmental impact assessment, enschede, itc publication, 32, pp. 324. pralong j.p. & reynard e. (2005) a proposal for a classification of geomorphological sites depending on their tourist value il quaternario, 18, pp. 313-319. quaranta g. (1993) geomorphological assets: conceptual aspect and application in the area of croda da lago (cortina d’ampezzo, dolomites) in: m. panizza, m. soldati & d. barani (eds), european intensive course on applied geomorphology, proceedings, istituto di geologia, università degli studi di modena, pp. 49-60. reynard e. (2002) institutional resource regime (irr). a tool for managing the protection and exploitation of geomorphological sites in: p. coratza & m. marchetti (eds), geomorphological sites: research, assessment and improvement , workshop proceedings, modena (italy), 19-22 june 2002, università degli studi di modena, dipartimento di scienze della terra, pp. 21-26. reynard e., morand s., ammann t. (2003) protection et mise en valeur touristique d’un site géomorphologique: la région du sanetsch (valais, suisse) in: e. reynard, c. holzmann, d. guex, n. 331geomorphological sites, public policies ... summermatter (eds.), géomorphologie et tourisme, lausanne, institut de géographie, travaux et recherches, 24, pp. 35-52. rivas v., rix k., frances e., cendrero a. & brunsden d. (1997) geomorphological indicators for environmental impact assessment: consumable and nonconsumable geomorphological resources geomorphology, 18, pp. 169-182. sas (1999) inventory of geotopes of national significance geol. insubr., 4 (1), pp. 31-48. schaer j.p. (2000) agassiz et les glaciers: sa conduite de la recherche et ses mérites eclogae geol. helv., 93, pp. 231-256. schardt h. (1908) la pierre des marmettes et la grande moraine de monthey eclogae geol. helv., 10, pp. 555-566. siebert h. (1983) ökonomische theorie natürlicher ressourcen tübingen, mohr. strasser a., heitzmann p., jordan p., stapfer a., stürm b., vogel a. & weidmann m. (1995) géotopes et la protection des objets géologiques en suisse: un rapport stratégique fribourg, groupe suisse pour la protection des géotopes. stürm b. (1994) intégration de la protection du patrimoine géologique dans l’aménagement du territoire en suisse mém. soc. géol. france, 165, pp. 93-97. twidale c.r. (1978) on the origin of ayers rock, central australia zeitschr. für geomorphologie, suppl bd, 31, pp. 177-206. 332 e. reynard sess 2_16022011_tpr3.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 a new late-glacial pollen record from valle di castiglione (rome) federico di rita1, anna paola anzidei2 & donatella magri1 1 dip. biologia ambientale, sapienza università di roma 2 soprintendenza speciale per i beni archeologici di roma, roma corresponding author: f. di rita <federico.dirita@uniroma1.it> abstract: di rita f., anzidei a.p. & magri d., a new late-glacial pollen record from valle di castiglione (rome). (it issn 0394-3356, 2011) new pollen data from valle di castiglione (rome) highlight the vegetation development of the roman area between 13,700 and 8000 cal bp. the late-glacial is characterized by a deforested landscape with a scanty presence of woody taxa during the interstadial. the postglacial development of forest vegetation is delayed by the local persistence of chenopods. evergreen trees are continuously present throughout the pollen record. riassunto: di rita f., anzidei a.p. & magri d., una nuova sequenza pollinica tardoglaciale a valle di castiglione (roma). (it issn 0394-3356, 2011) nuovi dati pollinici da valle di castiglione (roma) delineano lo sviluppo della vegetazione della campagna romana tra 13700 e 8000 anni dal presente. il tardoglaciale è caratterizzato da un paesaggio deforestato, con un modesto aumento di alberi durante la fase interstadiale. la reforestazione postglaciale è posticipata a causa della persistenza, probabilmente locale, di chenopodiacee. la vegetazione sempreverde è sempre presente. key words: pollen, late-glacial, central italy, mediterranean vegetation parole chiave: polline, tardoglaciale, italia centrale, vegetazione mediterranea an eccentric phreatomagmatic explosion crater of about 1 km in diameter belonging to the alban hills volcanic district. it is located at an elevation of 44 m a.s.l. approximately 20 km east of rome. the area experienced a long history of human frequentation since the neolithic, which certainly played an important role in the modification of the natural vegetational landscape of the site, whose potential vegetation is a mixed deciduous oak forest rich in mediterranean elements (blasi et al., 1995). 3. materials and methods the analyzed sediments were collected down to 4 m depth in the central portion of the former valle di castiglione maar lake (core vdc09). subsamples for pollen analysis were taken between 4 m and 1.35 m depth at 4 cm interval along the core. a total of 59 samples were chemically treated and analysed. the pollen sum does not include aquatics, hygrophytes, and spores. in the 20 samples with more than 50% ap (arboreal pollen) the mean count was 450 terrestrial pollen grains, while in the 39 samples with more than 50% nap (non arboreal pollen) an average of 340 terrestial pollen grains per sample were counted. pollen preservation was generally good, with an amount of indeterminable (degraded, corroded and broken) grains never exceeding 10%. on the whole, 80 pollen taxa were identified. the results are represented on a summary pollen diagram plotted against the age of the sequence (fig. 1). 1. introduction this study presents new pollen data from the valle di castiglione maar lake, a site that provided one of the longest palynostratigraphical sequences of southern europe (follieri et al., 1988). the new pollen record, studied within cooperation between the laboratory of palaeobotany of sapienza university and the soprintendenza speciale per i beni archeologici di roma, is supported by six ams dates and spans the time interval 13,700-8000 cal bp. it shows the vegetation development in the roman area during the late-glacial and early holocene. this represents a still poorly known timeperiod in the vegetation history of the roman area, because of the scarcity of both pollen data and satisfactorily robust chronological settings in the existing records. the main objectives of the present work are: a) to reconstruct the vegetation responses to the late-glacial climate fluctuations in the roman area; b) to obtain new data on times and modes of the holocene reafforestation in central italy; c) to provide insights into the development of the evergreen mediterranean vegetation during the transition from the late-glacial interstadial to the early holocene. 2. study area the site of valle di castiglione (41°53’30”n; 12° 45’35”e) is currently represented by the bed of an ancient lake, artificially dried out, which occupied 98 100 99 (7%) and a moderate but continuous record of evergreen vegetation (<6%). on the whole, the ap percentages (<40%) point to a mostly open landscape dominated by chenopods-artemisia steppes, less forested than other sites of the region (lowe et al., 1996; magri, 1999; sadori & magri, 1999). younger dryas the pollen record shows a new important development of xerophytic vegetation, mostly artemisia, paralleling a slight decrease in deciduous and evergreen vegetation. surprisingly, the diagram does not show a clear increase in conifers, differently from other records in the region (lowe et al., 1996; magri, 1999; sadori & magri, 1999). at valle di castiglione, during the interval 11,900-11,600 cal bp, conifers decrease, in correspondence with a cold shift in the gisp2 δ18o curve. during the younger dryas, the lake probably experienced major hydrological changes, as suggested by a marked increase in aquatics. early holocene between 11,500 and 11,100 cal bp, the vegetation history is characterized by a remarkable peak of chenopods, possibly related to site-specific vegetation dynamics overshadowing a reafforestation process by deciduous taxa. in fact, the regional steppe vegetation dominated by artemisia abruptly decreased at the younger dryas/ holocene transition. clear forest conditions (ap 70%), mostly determined by the development of the timescale was obtained by linear interpolation of six ams dates from bulk sediment (fig. 1), calibrated using the intcal09 calibration dataset (reimer et al., 2009). 4. results and discussion the vegetation development indicates that important changes in the vegetation structure and composition occurred in the landscape between 13,700 and 8000 cal bp, consistently with the main climate fluctuations recorded by the proxy gisp2 δ18o curve (fig. 1). late-glacial interstadial the samples of the valle di castiglione diagram between 13,700 and 13,500 cal bp are characterized by high amounts of pollen of herbaceous taxa (nap 90%) typical of the pleistocene stadial stages in southern europe (e.g. artemisia, chenopods and poaceae). this pollen composition may be related to either a landscape almost completely dominated by xerophytes, or overrepresentation of local taxa due to selective pollen preservation. the latter hypothesis is supported by the comparison with other pollen records of the latium region, where nap never reach such high values in this time interval (lowe et al., 1996; magri, 1999; sadori & magri, 1999). between 13,500 and 12,700 cal bp there is a significant development of deciduous vegetation (30%) accompanied by a fairly stable presence of conifers fig. 1, summary pollen percentage record from valle di castiglione (core vdc09) and the gisp2 δ18o record (available from http://www.ncdc.noaa.gov/paleo/icecore/greenland/summit/document/gispisot.htm) diagramma pollinico percentuale sintetico di valle di castiglione (vdc09) e curva gisp2 δ18o (da http:// www.ncdc.noaa.gov/paleo/icecore/greenland/summit/document/gispisot.htm)  a new late-glacial pollen record from valle ... 100 ms. received: testo ricevuto il trees corresponds to the attainment of high values in the gisp2 δ18o curve. references blasi c., dowgiallo g., follieri m., lucchese f., magri d., pignatti s. & sadori l. (1995) la vegetazione naturale potenziale dell'area romana. atti dei convegni lincei, 115, 423-457. follieri m., magri d. & sadori l. (1988) 250,000-year pollen record from valle di castiglione (roma). pollen spores, 30 (3-4), 329-356. lowe j., accorsi c.a., bandini-mazzanti m., bishop a., van der kaars s., forlani l., mercuri a.m., rivalenti c., torri p. & watson c. (1996) pollen stratigraphy of sediment sequences from lakes albano and nemi (near rome) and from the central adriatic, spanning the interval from oxygen isotope stage 2 to the present day. mem. ist. it. idrob., 55, 71-98. magri d. (1999) late-quaternary vegetation history at lagaccione near lago di bolsena (central italy). rev. palaeobot. palynol., 106, 171-208. magri d. & sadori l. (1999) late pleistocene and holocene pollen stratigraphy at lago di vico (central italy). veg. hist. archaeobot., 8, 247-260. reimer p.j., baillie m.g.l., bard e., bayliss a., beck j.w., blackwell p.g., bronk-ramsey c., buck c.e., burr g.s., edwards r.l., friedrich m., grootes p.m., guilderson t.p., hajdas i., heaton t.j., hogg a.g., hughen k.a., kaiser k.f., kromer b., mccormac f.g., manning s.w., reimer r.w., richards d.a., southon j.r., talamo s., turney c.s.m., van der plicht j. & weyhenmeyer c.e. (2009) intcal09 and marine09 radiocarbon age calibration curves, 0– 50,000 years cal bp. radiocarbon, 51, 1111-1150. deciduous taxa, appear only around 11,100 cal bp. conifers show a steady decline from 10,900 to 8000 cal bp. evergreen vegetation experienced a slow increase from 11,300 to 10,200 cal bp, in agreement with the postglacial increase of the gisp2 δ18o values. around 10,200 cal bp an abrupt rise of evergreen trees (20%), followed by fairly stable values (>10%) up to the top of the diagram, suggests that evergreen communities became important elements of the vegetational landscape, approximately at the time when δ18o values from gisp2 reached a high and stable level. 5. conclusions the new pollen analysis from valle di castiglione indicates that very diversified ecological situations have followed each other in the roman area between 13,700 and 8000 cal bp: • the late-glacial interstadial is characterized by a deforested landscape dominated by steppe vegetation (artemisia-chenopods-poaceae), with a modest increase of trees compared to the other pollen records of the region. • although the prodromes of the holocene reafforestation started around 11,500 cal bp, a clear forest recovery appeared only at about 11,100 cal bp, probably because of a local marked persistence of herbaceous taxa. • evergreen mediterranean trees show a continuous record, suggesting their constant presence in the vegetational landscape even during the lateglacial oscillations. a clear increase of evergreen january 13, 2011 13 gennaio 2011 f. di rita, a.p. anzidei & d. magri sess 2_16022011_tpr2.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 mapping the geomorphological scenarios of the friuli venezia giulia region (ne italy): a tool for the evaluation of the local seismic amplification sara biolchi1, luca zini1, paolo leita2 & petra malisan2 1 dipartimento di geoscienze, università degli studi di trieste, italy 2dipartimento di chimica fisica e ambiente, sezione georisorse e territorio, università di udine, italy corresponding author: s. biolchi <sbiolchi@units.it> abstract: biolchi s. et al., mapping the geomorphological scenarios of the friuli venezia giulia region (ne italy): a tool for the evaluation of the local seismic amplification. (it issn 0349-3356, 2011) the friuli venezia giulia region was affected by several destructive earthquakes over the last centuries. in order to identify the causes of the local seismic amplification, geomorphological scenarios has been proposed. they represent the site-specific geological, geomorphological and topographical characteristics (geo-morphotypes). we represent the whole region in terms of these geo-morphotypes in a map. riassunto: biolchi s. et al ., rappresentazione degli scenari geomorfologici della regione friuli venezia giulia: uno strumento per la valutazione dell’amplificazione sismica locale. (it issn 0349-3356, 2011) la regione friuli venezia giulia è stata interessata da numerosi e disastrosi eventi simici. anche al fine di individuare le cause dell’amplificazione sismica locale, sono stati individuati e cartografati in ambiente gis gli scenari geomorfologici che possono generare amplificazione del moto sismico locale. key words: friuli venezia giulia region, geomorphological scenarios, geo-morphotypes map parole chiave: regione friuli venezia giulia, scenari geomorfologici, carta dei geo-morfotipi 1. introduction the friuli venezia giulia region was affected by several destructive earthquakes over the centuries. locally the occurrence of the quaternary deposits covering the bedrock plays a remarkable role on the site effects. as a matter of fact, the seismic motion can be subjected to amplification because of the occurring of particular local morphological conditions (di bucci et al., 2005). the “geo-morphotypes map” was developed to represent on a large scale the distribution of the geomorphological scenarios which can be responsible of seismic amplification. 2. study area the friuli venezia giulia region, in ne italy, represents the north-eastern portion of the deformed margin of the adria microplate, where a complex interaction between two orogenic chains occurs. the mountainous part comprises the hinge zone between the eastern sector of the southern alps (s and se vergence) and the north-western part of the external dinarides (sw vergence) (carulli, 2006). the region can be subdivided into: a mountain region (about 3200 km2), a foothill region (about 1400 km2), the plain (about 2800 km2), the coast and lagoon areas (about 160 km2) and, in the southeast, the karst (about 200 km2). in the region outcrop rocks belonging to a stratigraphic succession spanning in time from 460 my to present. rocks are mostly sedimentary and their thickness is over 15 km. limestones and dolostones prevail over terrigenous rocks such as sandstones, argillites, siltites and conglomerate or breccias. the quaternary deposits are represented by recent moraines, often overfed detrital deposits and alluvial sediments. the lasts can be more than 500 meters thick, are gravelly upriver and mudsandy downriver. fig. 1, the geomorphological scenarios (geo-morphotypes). gli scenari geomorfologici (geo-morfotipi). 79 80 80 ms. received: testo ricevuto il 3. discussion these scenarios were defined taking into account the amplification factors as the stratigraphic, geometrical and topographical effects, defining at first the impedance contrast between rock materials (vs > 800 m/s) and soft sediments/soil (vs < 800 m/s) and the slope, which has been subdivided in 3 classes (< 8°, 8-15°, > 15°). the geometries were defined considering the eurocode 8 (eurocode 8, 1998). 14 geomorphological scenarios, which are described below with their areal extension (the “geo-morphotypes”, fig. 1), were proposed: 1. flat plain in rock (slope <8°, 187 km2); 2. flat plain in soil (slope <8° and soil thickness >30 m, 2824 km2); 3. moderate slope in rock (slope between 8° and 15°,307 km2); 4. moderate slope in soil (slope between 8° and 15° and soil thickness >30 m, 102 km2); 5. steep slope in rock (slope >15°, 2495 km2); 6. steep slope in soil (slope >15° and soil thickness >30 m, 451 km2); 7. foothill zone (slope <8° and soil thickness <100 m, 598 km2); 8. edge of scarp in rock (elevation (h) >10 m and distance from the edge <3h, 24 km2); 9. alluvial terrace (soil thickness > 30 m, elevation (h) >10 m and distance from the edge <3h, 14 km2); 10. valley in rock (sides slope >15° and width <250 m, 28 km2); 11. shallow valley (in soil; sides slope >15°, width <250 m and thickness of soil <30 m, 187 km2); 12. deep valley (in soil; sides slope >15°, width >250 m and thickness of soil >30 m, 13 km2); 13. crest (in rock; sides slope >15°, flat area on the top slope <15°, width between 100 and 250 m and elevation >30 m, 428 km2); 14. alluvial fan (in soil, 34 km2). the geo-morphotypes map (fig. 2) was carried out in order to represent the whole region using the 14 geo-morphotypes. the map was developed using arcgis 9.x and was obtained from the overlapping of different layers: the slope map obtained from the digital terrain model, the geological maps of the region at different scales, the subsurface structures map and the database of the regional wells. for each geo-morphotype has been worked out the average relative amplification factors in order to classify the more hazardous scenarios (grimaz, 2008). the geomorphological scenarios not only describe the territory from a geological and geomorphological point of view, but also provide a good description of sites affected by the seismic action and consequently define a useful zonation to recognize the local seismic response. therefore, the potential effects of geo-morphologic scenarios should be taken into account in the risk assessment because they could change substantially the intervention priorities. references carulli g.b. (2006) carta geologica del friuli venezia giulia, scala 1:150.000 con note illustrative, regione autonoma friuli venezia giulia, direzione regionale ambiente e lavori pubblici, servizio geologico regionale. di bucci d., naso g., marcucci s., milana g. & sanò’ t. (2005) – a methodology to account for local geology at large in the sha approach through numerical modeling for theoretical geological sections. boll. geof. teor. appl., 46, 1, 1-22. eurocode 8, (1998) en 1998 – design of structures for earthquake resistance. grimaz s. (2008) – a posteriori quantification of seismic amplification factors for different geo-morphological scenarios. proceedings of “27° convegno nazionale del gngts”, 245-248. fig. 2, the “geo-morphotypes map” of the friuli venezia giulia region (to simplify the representation of the map, originally at 1:150.000 scale, some geo-morphotypes were grouped). la “carta dei geomorfotipi” della regione friuli venezia giulia (per semplificare la rappresentazione della carta, originariamente in scala 1:150.000, alcuni geo-morfotipi sono stati raggruppati). s. biolchi et al. january 31, 2011 31 gennaio 2011 sess 2_16022011_tpr3.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 post-glacial evolution of gravitational slope deformations in the upper susa and chisone valleys (italian western alps) gianfranco fioraso1, paolo baggio2, livio bonadeo3 & fabio brunamonte2, 3 1 cnr istituto di geoscienze e georisorse torino 2 ig ingegneria geotecnica torino 3 dipartimento di scienze chimiche e ambientali università dell’insubria corresponding author: g. fioraso <g.fioraso@csg.to.cnr.it> abstract: fioraso g. et al., post-glacial evolution of gravitational slope deformations in the upper susa and chisone valleys (italian western alps). (it issn 0394-3356, 2011) the upper susa and chisone valleys host the largest concentration of deep-seated gravitational slope deformations (dsgsd) and large landslides of the whole alpine chain. this is due i) to the lithostructural characteristics of bedrock and ii) to the intense and the prolonged glacial scouring during the upper pleistocene. deep drill holes carried out on seven large landslides show that the evolution of gravitational phenomena has completely re-shaped the original postglacial morphology of valley bottoms. riassunto: fioraso g. et al., evoluzione post-glaciale dei fenomeni gravitativi nelle alte valli di susa e chisone (alpi occidentali). (it issn 0394-3356, 2011) in alta valle di susa e in alta val chisone è ospitata la maggiore concentrazione di deformazioni gravitative profonde di versante (dgpv) e grandi frane dell'intero arco alpino. questa particolarità è dovuta i) alle caratteristiche litostrutturali del substrato roccioso e ii) all'intenso approfondimento erosivo dei solchi vallivi operato dai ghiacciai nel corso del pleistocene superiore. le indagini di sottosuolo svolte su sette grandi frane evidenziano come l'evoluzione dei fenomeni gravitativi abbia completamente ridisegnato e/o mascherato l'originaria morfologia post-glaciale. key words: lgm, glacial scouring, gravitational slope deformations, landslide dams parole chiave: lgm, modellamento glaciale, deformazioni gravitative di versante, sbarramenti di frana in tectonically active areas like alpine chain, the geological work accomplished by glaciers include, beside erosion and removal of superficial deposits, over-deepening and reshaping of valley bottoms and valley sides respectively. this results in oversteepened slopes and increase of reliefs, in turn inducing diffuse rock mass disequilibrium. as a conseguence, after the complete retreat of glaciers, valley sides tend to adjust to the new morphological arrangement. this context is prone to the developement of diffuse instability phenomena such us landslides and deep-seated gravitational slope deformations (dsgsd). in the northern cottian alps post-glacial gravitational deformations have given rise to diffuse and impressive collapse phenomena (fioraso et al., 2010), leading to the highest concentration of slope instability phenomena of the alps. this is due to lithological composition of bedrock (mortara & sorzana, 1987) and, secondly, to the structural set-up of the area (giardino & polino, 1997; polino et al., 2002). in many cases landslide dams have been formed (fig. 1) with remarkably different age, genesis and characteristics (carraro & forno, 1980; tropeano & olive, 1993; polino et al., 2002). to improve the knowledge of such a phenomena, detailed investigations has been focused on seven large landslides, four of them located in the upper susa valley and the others in the upper chisone valley. this study was based on geological mapping, morpho-structural analysis and subsurface investigations. thirteen drill holes with continuous coring were performed up to 110 m in depth (with a total lenght of 1125 m), accompanied with the installation of an integrated monitoring system (inclinometers, piezometers and gps bench marks network). the large amount of new morphological and subsurface data collected led to the recognition of an unexpected stratigraphic arrangement, useful for a properly reconstruction of the original postglacial valley bottom morphologies. -bedrock geology is mainly characterized by a stack of tectono-stratigraphic units belonging to the piedmont zone and made up of monotonous calcschistes with ophiolitic intercalations (serpentinites, ophicalcites and metabasites). only in the left side of the upper susa valley and along the french-italian border, continental crust units (ambin massif) and carbonatic units (chaberton grand hoche grand argentier unit) referred to the internal briançonnnais zone are exposed. in the susa and chisone valleys diffuse landforms and sediments testify the intensity of the glacial action during the upper pleistocene. detailed geomorphological and lithological field mapping have allowed the reconstruction of the former 104 106 105 involved by huge dsgsds, the whole slope preserve scattered morphological features and deposits related to the lgm and subsequent glacial retreat stages. translational movements of rock masses (with minor rotational components) take place along sliding surfaces having complex geometry, that reactivate pre-existing low and high angle discontinuities affecting bedrock. however, in spite of uniformity of the geological and structural context observed around sites, the landslides are characterized by different morphology and kinematic behaviour. moreover, each landslide display independent and multistage evolution, glacier extents and successive over-deepening stages (polino et al., 2002). after the last glacial maximum (lgm) the retreat of the glaciers was quickly followed by the development of the gravitational phenomena such as rock falls, rock slides, rock flows and sackungs. -in the upper susa valley four gravitational phenomena has been analysed: roche rouge, champlas seguin, champlas janvier and champlas du col. they are located on the right side of the ripa torrent between the villages of cesana and sestriere (fig. 1). such landslides take up an area ranging from 0.4 to 3.4 km2 and reach a maximum depth of 80 m. although fig. 1 landslides and dsgsds distribution in the upper susa and chisone valleys. numbers refer to the investigated landslides. 1: roche rouge; 2: champlas seguin; 3: champlas janvier; 4: champlas du col; 5: duc; 6: plan; 7: balboutet. distribuzione di frane e dgpv nell'alta valle di susa e nell'alta val chisone. i numeri indicano i fenomeni gravitativi investigati. 1: roche rouge; 2: champlas seguin; 3: champlas janvier; 4: champlas du col; 5: duc; 6: plan; 7: balboutet. post-glacial evolution of gravitational slope ... 106 ms. received: testo ricevuto il ciantiplagna peak (2849 m). the blocky deposit covers an area of 3.53 km2 with a maximum thickness of 120-130 m. rock avalanche accumulation has dammed the valley, causing upstream the development of a broad fluviolacustrine plane 4 km long (polino et al., 2002). continuous coring drill hole performed on valley bottom up to 90 m in depth, reveals that the rock avalanche deposits rest on a large rock slide (30 m thick) in turn resting above a glacial and fluviolacustrine succession. the detailed investigation carried out on some landslides in the northern cottian alps points out that the present day morphology of the upper susa and chisone valley sides is significantly different from that followed the glacial retreat at the end of the lgm. erosional action of glacier led to overdeepening of the valley bottom and progressive slope steepening: increase of relief and undermining of slopes cause shear stress of sufficient magnitude to induce widespread relaxation of rock masses and the development of landslides and dsgsds. the study confirm that gravitational phenomena repeatedly interacts with fluvial dynamics, reshaping the valley profile compared to the original slope configuration present soon after the postlgm glacial retreat. in some cases (roche rouge and balboutet) landslides obstruct the drainage system, creating impounded lakes and variations on base level and rivers planform extending much farther downstream and upstream. references carraro f. & forno m.g. (1981) segnalazione di una paleofrana in val chisone presso fenestrelle (prov. di torino). geogr. fis. dinam. quat., 4, 48-54. fioraso g., tararbra m. & negro n. (2010) la deformazione gravitativa profonda di sauze d’oulx (alpi occidentali): analisi dei meccanismi deformativi in relazione all’evoluzione tardo quaternaria dell’alta valle di susa. il quaternario, it. journ. quat. sci, 23(1), 3754. giardino m. & polino r. (1997) le deformazioni di versante dell’alta valle di susa: risposta pellicolare dell’evoluzione tettonica recente. il quaternario, 10(2), 293-298. mortara g. & sorzana p.f. (1987) fenomeni di deformazione gravitativa profonda nell'arco alpino occidentale italiano. considerazioni lito-strutturali e morfologiche. boll. soc. geol. it., 106, 303-314. polino r., borghi a., carraro f., dela pierre f., fioraso g. & giardino m. (2002) note illustrative della carta geologica d'italia alla scala 1:50.000. foglio 132-152-153 “bardonecchia”. servizio geologico d'italia, 128 tropeano d. & olive p. (1993) eventi geomorfologici nelle alpi italiane e nella pianura occidentale del po: inquadramento cronologico in base a radiodatazioni 14c. il quaternario, 6(2), 189-204. involving glacial and fluvial deposits in the valley floor. the foots of champlas janvier and champlas du col landslides mask an ancient thick (80 m) fluvio-lacustrine succession (fig. 2), part of which outcrops on the left side of the valley bottom. this sediments has been accumulated as a consequence of the contemporary rapid movement of the roche rouge rock slide and the buon soccorso rock flow (located in the opposite side of the valley), causing in the early stage of the holocene the dam of the ripa torrent and the genesis of the bousson lake (with an estimated area of al least 1.6 km2 and a lenght of 3.5 km), now extinct. in the upper chisone valley three gravitational phenomena has been analysed (fig. 1). the duc and plan landslides, located on the left side of the chisonetto torrent between the villages of sestriere and pragelato, correspond to complex rock slides both with an area of 0.29 km2. the balboutet landslide, located on the left side of the chisone valley between pourrieres and fenestrelle, corresponds to a huge rock avalanche detached from the southern slope of the fig. 2 schematic geological cross sections of the roche rouge, champlas janvier and champlas du col landslides. sezioni geologiche schematiche dei fenomeni gravitativi di roche rouge, champlas janvier e champlas du col. g. fioraso et al. january 14, 2011 14 gennaio 2011 imp.scicchitano_monaco grotte carsiche e linee di costa sommerse tra capo santa panagia e ognina (siracusa, sicilia sud-orientale) giovanni scicchitano & carmelo monaco dipartimento di scienze geologiche, università di catania, corso italia, 55, 95129 catania email: cmonaco@unict.it; gscicchi@unict.it riassunto: scicchitano g. & monaco c., grotte carsiche e linee di costa sommerse tra capo santa panagia e ognina (siracusa, sicilia sud-orientale). (it issn 0394-3356, 2007). la zona costiera della sicilia sud-orientale compresa tra capo s. panagia e ognina (siracusa) è caratterizzata dalla presenza di numerose paleo-linee di costa sollevate, legate a stazionamenti del livello del mare durante il tardo quaternario. esse sono rappresentate da falesie e spianate d’abrasione scavate su una successione calcarea miocenico-pleistocenica e sono collegate spesso a forme di erosione di tipo carsico (grotte, canali, sifoni etc.) al cui interno sono stati ritrovati numerosi speleotemi (stalattiti, stalagmiti, concrezioni cipollari). sotto il livello del mare si riscontrano gli stessi caratteri morfologici, in quanto i fondali sono caratterizzati da almeno due paleo-falesie marine, una tra -9÷12 m e -20÷22 m l’altra tra -20÷25 m e -40÷45 m, verso cui si aprono cavità sommerse, sifoni e canali, ospitanti a volte speleotemi continentali fossilizzati. il presente lavoro consiste nel rilevamento dettagliato dei fondali marini antistanti la linea di costa tra capo s. panagia e ognina, al fine di ricostruire l’andamento spaziale e la continuità degli elementi morfologici sommersi e di stabilirne la possibile genesi ed evoluzione temporale. questi elementi morfologici possono essere interpretati come testimonianze di stazionamenti pleistocenici del livello del mare, ora sommersi a causa della veloce risalita olocenica del livello del mare. abstract: scicchitano g. & monaco c., karstic caves and submerged paleo-shorelines in the coastal area between capo santa panagia and ognina (siracusa, south-eastern sicily). (it issn 0394-3356, 2005). the aim of this work is the detailed survey of the submerged area in front of the shoreline between capo s. panagia e ognina (siracusa), in order to reconstruct the lateral extension and the continuity of the submerged morphological elements and to define their genesis and temporal evolution. this coastal stretch is characterized by the occurrence of several raised paleo-shorelines, related to late quaternary high-stands. they are represented by cliffs and abrasion platforms carved on a miocene-pleistocene carbonatic succession and are often linked to karstic levels (caves, channels, siphons, etc.). several speleothems, such as stalagmites, stalactites, columns, cave pearls, have been found in the caves. the submerged area is characterized by the same morphological features. the sea-bottom is, in fact, characterized by at least two palaeo-cliffs of marine origin, the shallower one located at depths between -9÷12 m and -20÷22 m, the deeper one located at depths between -20÷25 m and -40÷45 m. the scarp located between -9÷12 m and 20÷22 m is well preserved and shows a continuity of about 20 km. the scarp located between -20÷25 m and -40÷45 m is more discontinuous and steeper. several caves, channels and siphons, characterized by the occurrence of continental fossilized speleothems, have been found along these scarps, probably linked to palaeo-karstic levels. the detailed topographic survey of two caves has been carried out and a stalagmite has been sampled in order to determine its age and to reconstruct the relationships between sea-level rise and vertical tectonic motion of the area. the morphological analysis and the first dating results suggest that the two submerged palaeo-shorelines can be interpreted as the effect of late pleistocene sea level stands. at present they are submerged as a consequence of the sudden holocene sea-level rise. parole chiave: carsismo, paleo-linee di costa, olocene, sicilia sud-orientale. keywords: karstism, paleo-shorelines, holocene, south-eastern sicily. il quaternario italian journal of quaternary sciences 19(2), 2006 187-194 1. introduzione l’area costiera di siracusa in sicilia sud-orientale (fig. 1) è caratterizzata dalla presenza di vari ordini di terrazzi e spianate d’abrasione, che si sviluppano dalla linea di costa attuale sino a diversi chilometri da essa, nonché dalla presenza di varie scarpate morfologiche che, presentando indicatori di livello marino di vario genere (solchi di battente, piattaforme a vermetidi, fori di litodomi) sono state interpretate come paleo-linee di costa legate a stazionamenti del livello del mare durante il tardo quaternario (carbone et al., 1982; di grande & raimondo, 1982; bianca et al., 1999). queste paleolinee di costa sono ubicate al bordo interno di piattaforme d’abrasione marina ed essendo scavate su formazioni calcaree (formazioni di monti climiti e di monte carruba, a.a.v.v., 1986) sono collegate a livelli paleocarsici (ruggieri & amore, 2000; ruggieri & grasso, 2000). le forme prevalenti lungo le paleo-linee di costa emerse dell’ area considerata, come anche lungo le falesie costiere attuali, sono rappresentate da grotte, canali e sifoni al cui interno sono stati ritrovati numerosi speleotemi (stalattiti, stalagmiti, concrezioni cipollari). sotto il livello del mare si riscontrano gli stessi caratteri morfologici, in quanto i fondali sono caratterizzati da numerosi elementi morfologici, tra cui cavità sommerse, sifoni e canali, che possono essere interpretati come testimonianze di antichi stazionamenti del livello del mare ora sommerse a causa della veloce risalita olocenica. questi elementi morfologici sono in genere allineati alla base di piccole scarpate sottomarine. i fondali antistanti le coste siracusane sono infatti caratterizzate da improvvise rotture di pendio, site a profondità diverse, con sviluppo laterale chilometrico 188 g. scicchitano & c. monaco (fig. 2). lungo tali scarpate si aprono numerose grotte sommerse il cui ingresso coincide quasi sempre con la base delle scarpate e al cui interno spesso si ritrovano speleotemi di vario tipo (leonardi, 1994) che denunciano una speleogenesi carsica continentale delle grotte stesse. scopo del presente lavoro è presentare il rilevamento dettagliato dei fondali marini antistanti la costa tra capo santa panagia e ognina (siracusa), al fine di ricostruire l’andamento spaziale e la continuità delle scarpate sommerse e di stabilirne la possibile genesi ed evoluzione temporale. a questo scopo sono state effettuate oltre 50 ore d’immersione lungo tutta l’area, durante le quali è stato eseguito il rilevamento batimetrico e topografico degli elementi riscontrati tramite posizionamento con gps e bussola a puntamento. in particolare, la base delle scarpate sottomarine è stata pedagnata sul fondo dagli operatori subacquei e segnalata in superficie da boe poi rilevate a mezzo di gps interfacciato con eco-scandaglio. inoltre è stato eseguito il rilievo topografico di dettaglio di due grotte che presentano al loro interno speleotemi continentali. infine sono stati campionati alcuni speleotemi su cui sono in corso datazioni assolute con i metodi u/th e radiocarbonio al fine di ricostruire le relazioni tra movimenti tettonici verticali e variazioni del livello del mare fig. 1 schema tettonico del sicilia sud-orientale. il riquadro in basso a sinistra mostra l’area del mediterraneo centrale con il sovrascorrimento frontale dell’orogene (linee con triangoli) e le principali faglie quaternarie (linee con tratti). tectonic sketch map of south-eastern sicily. inset shows the central mediterranean area with the frontal thrust of the orogenic belt (lines with triangles) and main quaternary faults (lines with barbs). (v. alessio et al., 1994; antonioli et al., 1998) nell’area durante il tardo quaternario (dutton et al., in preparazione). 2. inquadramento geologico-morfologico la costa siracusana è ubicata nelle propaggini orientali del plateau ibleo in sicilia sud-orientale e fa parte quindi dell’area d’avampaese dell’orogene siculomaghrebide (fig.1). la successione litostratigrafia affiorante comprende terreni sedimentari ed eruttivi d’età compresa tra il cretaceo e l’attuale (a.a.v.v, 1986). la linea di costa è caratterizzata dalla presenza di due penisole rocciose, di santa panagia e della maddalena (fig. 2), costituite da sedimenti carbonatici organogeni di mare basso di età neogenico-quaternaria, separate da un’ampia baia (porto grande di siracusa), in cui 189grotte carsiche e linee di costa sommerse ... affiorano depositi pelitici pleistocenici e fluvio-costieri olocenici, a sua volta chiusa a nord-est dall’isola di ortigia. gli elementi morfostrutturali più evidenti sono costituiti dall’horst di belvedere-santa panagia, orientato in direzione est-ovest, dal graben pleistocenico di floridia e dall’horst della penisola della maddalena, orientato in direzione nnw-sse (fig. 1). i dati morfologici e geologici, insieme con l’analisi di profili sismici eseguiti lungo l’offshore ionico (bianca et al., 1999; monaco & tortorici, 2000), suggeriscono che la deformazione più recente di questa zona sia rappresentata da un lento sollevamento legato all’attività di una faglia ubicata nell’offshore ionico, con orientazione nnw-sse, che ha riattivato il sistema mesozoico della scarpata ibleo-maltese (fig. 1). l’elemento morfologico principale dell’area in esame è rappresentato da una gradinata di ampie spianate d’erosione d’età pleistocenica, limitate verso monte da evidenti paleo-linee di costa (carbone et al., 1982; di grande & raimondo, 1982; bianca, 1999; bianca et al., 1999) che testimoniano i sollevamenti subiti dall’area a causa dell’attività della faglia ubicata offshore. tassi di sollevamento medi di circa 0,6 mm/a sono stati stimati per l’area di siracusa a partire da 400 ka (bianca et al., 1999). nonostante il lento sollevamento, l’area costiera è stata invasa dal mare durante la risalita del l ivello marino nel corso dell’olocene (lambeck et al., 2004) come testimoniato dalla presenza di numerosi resti archeologici oggi sommersi (scicchitano et al., in preparazione) e da un’analisi di facies su depositi transizionali eseguita poco a nord di siracusa (monaco et al., 2004). 3. morfologia delle aree sommerse i fondali antistanti la costa siracusana sono caratterizzati da almeno due paleo-falesie, una ubicata a profondità tra 9÷12 m e -20÷22 m l’altra tra 20÷25 m e -40÷45 m (fig. 2), verso cui si aprono cavità sommerse, sifoni e canali, ospitanti a volte speleotemi continentali fossilizzati (fig. 3a). la scarpata sommersa tra -9÷12 m e -20÷22 m rappresenta l’elemento morfologico più continuo e meglio conservato dei fondali esaminati. essa si sviluppa con batimetria costante per circa 20 km, con la cresta della scarpata alla profondità media di circa 10 m e la base a circa -20 m fig. 2 carta morfo-strutturale dell’area costiera di siracusa (ubicazione in fig. 1). morpho-structural map of the siracusa coastal area (location in fig. 1). 190 fig. 3 a) speleotemi continentali con incrostazioni marine in una grotta sommersa a profondità di circa -20 m; b) stalattite sulla volta della grotta del plemmirio; c) stalagmite di dimensioni metriche nella terza camera della grotta del plemmirio; d) fase di recupero della stalagmite del plemmirio; e) ingresso principale della grotta delle corvine; f) ingresso secondario della grotta delle corvine; g) colonne su una parete della grotta delle corvine; h) ingresso principale della grotta di san corrado. a) continental speleothems with marine incrustations in a submerged caves at -20 m depth; b) stalactite on the roof of the plemmirio cave; c) 1 m high stalagmite in the third room of the the plemmirio cave; d) sampling of the plemmirio stalagmite; e) main entrance of the corvine cave; f) secondary entrance of the corvine cave; g) columns on a wall of the corvine cave; h) main entrance of the san corrado cave. a) c) e) g) h) f) d) b) g. scicchitano & c. monaco 191 (fig. 2). lungo la scarpata sono state riscontrate una trentina di grotte e cavità, le quali presentano uno sviluppo quasi sempre cunicolare o raramente caratterizzato da ampie stanze comunicanti tramite stretti passaggi o sifoni verticali. da sud verso nord la scarpata è stata cartografata a partire dal punto di coordinate 36°58’27,0”n 15°16’02,0”e antistante il promontorio di capo ognina. qui la scarpata sommersa si mantiene ad una distanza dalla costa di 500 m, mentre verso nord, in corrispondenza di punta asparano, punta arenella e punta milocca (fig. 2), si avvicina a 200÷300 m. in questo settore la scarpata presenta una morfologia a gradinata con pochi tratti verticali e non è stata riscontrata la presenza di grotte o cavità. da punta milocca fino alla punta sud-occidentale della penisola della maddalena (plemmirio) la scarpata sommersa, pur mantenendo le stesse caratteristiche, si avvicina alla linea di costa fino al punto di coordinate 37°00’15,3”n 015°18’44,4”e, corrispondente con l’ ingresso della “grotta del plemmirio”, conosciuta anche come “grotta del gymnasium” (leonardi, 1994), ubicato a -22 m di profondità (fig. 2). in corrispondenza della “grotta del plemmirio” la scarpata dista circa 80 m dalla costa e presenta un salto netto da -10,5 m a -22 m, con pareti verticali prive di asperità e senza accumuli di crollo alla base. lungo il ciglio della parete a -12 m si osservano lunghi solchi longitudinali. dalla cima della scarpata verso la costa i fondali si presentano rocciosi e alla profondità monotona di -9/10 m fin quasi a riva dove le falesia è bassa e poco acclive. procedendo verso est, lungo la costa meridionale della penisola della maddalena, la scarpata si presenta continua e sub-verticale, a profondità costante e distante dalla linea di costa fino ad un massimo di circa 120 m. in prossimità del capo murro di porco e per ulteriori 600 m circa verso nord (fig. 2), si avvicina all’alta falesia attuale seguendola quasi parallelamente. lungo la costa nordorientale della penisola maddalena la scarpata prosegue ininterrotta mantenendosi a distanze superiori dalla costa. in prossimità dell’imboccatura del porto grande di siracusa la scarpata scompare al di sotto dei sedimenti trasportati dal fiume anapo (fig. 2) e i fondali portuali si presentano monotoni e poco acclivi anche se talora interrotti da piccoli gradini topografici di pochi metri d’altezza. la scarpata tra -9÷12 m e -20÷22 m riappare in prossimità dell’estrema punta meridionale dell’isola di ortigia (fig. 2). verso nord la scarpata sottomarina si allontana dalla costa fino al punto, distante più di 500 m, in cui è ubicata la “grotta delle corvine” (vedi sotto), per poi riavvicinarsi in prossimità di capo santa panagia. in questo settore la continuità della scarpata viene interrotta da due ampi accumuli di detrito che ricoprono con grossi blocchi i fondali a profondità compresa tra -9 m e -25 m. in questo settore, nonostante i sedimenti detritici tendano a obliterare la scarpata, sono ancora riconoscibili esempi di morfologie carsiche relitte come sifoni verticali ed ampie cavità con all’interno speleotemi a volte di notevoli dimensioni (ad es. grotta di san corrado, vedi sotto). un’altra scarpata sommersa, che si estende a profondità tra -20÷25 m a -40÷45 m, è stata rilevata verso il mare aperto, soprattutto al largo di capo santa panagia, di capo murro di porco e tra punta milocca e capo ognina (fig. 2). questa seconda scarpata non è continua ma intervallata per lunghi tratti da fondali poco acclivi. essa presenta una morfologia sub-verticale e priva di asperità nelle aree di capo santa panagia e capo murro di porco e una morfologia a gradoni lungo la costa che corre tra punta milocca e capo ognina. lungo le pareti di questa scarpata sono state riscontrate numerose cavità, canali, archi e sifoni. a sud-est di capo murro di porco (fig. 2), a circa 100 m di distanza dalla costa, si trova una piccola secca (“secca del capo”) la cui sommità giace alla profondità di -13 m mentre la base tra -40 e -50 m. le spettacolari pareti verticali, ricche di vita e spazzate da forti correnti, formano un’unica scarpata. numerose sono le cavità di origine carsica che si trovano lungo le pareti sud-orientali della secca, principalmente a profondità comprese tra -15 m e -30 m, dove sono stati osservati alcuni speleotemi. 4. cavità carsiche sommerse lungo la scarpata sottomarina ubicata tra -9÷12 m e -20÷22 m sono state riscontate numerose cavità di genesi carsica. la maggior parte di esse sono rappresentate da cunicoli poco profondi ubicati lungo faglie o fratture allargate da processi di corrosione paleocarsica o per opera del mare. numerosi sono anche i sifoni verticali e i canyon sommersi, probabili paleo-incisioni fluviali invase dal mare durante la sua risalita olocenica. la grotta del plemmirio, ubicata a -22 m a sud della penisola della maddalena (fig. 2) e già rilevata da leonardi (1994), rappresenta l’esempio più conosciuto e importante del campo carsico sottomarino al largo della costa siracusana. lunga 80 m, è composta da quattro ambienti a fondo pelitico, ricchi di speleotemi e collegati da stretti passaggi. la volta di passaggio tra il primo e il secondo ambiente è costellata di stalattiti decimetriche (fig. 3b), mentre la volta del secondo ambiente presenta decine di stalattiti di dimensioni variabili da 0,5 m a 2,5 m. il terzo ambiente presenta volte alte fino a 6 m e ospita due stalagmiti alte circa 1 m (fig. 3c), ricoperte da incrostazioni di serpulidi. una delle due stalattiti, ubicata a -20 m, è stata campionata per uno studio di dettaglio (fig. 3d) ed è stata determinata l’età assoluta dei primi organismi incrostanti con il metodo del radiocarbonio (circa 8 ka; dutton et al., in preparazione). al largo della costa della penisola di santa panagia, lungo la scarpata tra -9÷12 m e -20÷22 m, sono state esplorate altre due grotte (grotta delle corvine e grotta di san corrado, fig. 2), ritenute importanti sia per estensione che per la presenza di numerosi speleotemi continentali. di queste cavità sottomarine è stato effettuato il rilievo topografico di dettaglio. 4.1 grotta delle corvine (coordinate 37°04’14,5”n – 015°18’08,8”e) la grotta delle corvine si apre alla profondità di 20,5 m ad est di ortigia (fig. 2). presenta due distinti ingressi (fig. 4) il più ampio dei quali, largo circa 6 m (fig. 3e), collega direttamente con un’ampia camera, mentre quello secondario presenta morfologia cunicolare (fig. 3f). il fondo, coperto da sedimenti pelitici sciolti, si trova a una profondità pressoché costante grotte carsiche e linee di costa sommerse ... 192 tranne il settore finale del lungo corridoio (vedi sez. a – b in fig. 4) dove affiora un pavimento roccioso che risale fino a -14 m. lo spessore dei sedimenti (misurato con sondino d’acciaio) supera i 2 m nella prima camera ma si riduce notevolmente fino a poche decine di cm lungo i l corridoio che porta all’ult ima camera. l’idrodinamismo all’interno della grotta è molto basso o del tutto assente. le porzioni prossimali alle aperture sono densamente popolate e le pareti incrostate da organismi di vario genere mentre gli ambienti più interni, più selettivi in quanto quasi sciafili, mantengono una bassa densità di popolamento. nella seconda camera staziona un folto branco di corvine, da cui il nome della grotta. diversi gruppi di speleotemi di dimensione molto variabile, costituiti prevalentemente da stalattiti e colonne (fig. 3g), sono ubicati in tutte e tre le camere che compongono la grotta ad una profondità compresa tra -17 m e -14 m. 4.2 grotta di s. corrado (coordinate 37°06’02,7”n – 015°18’17,2”e) la grotta di san corrado (fig. 5) è sita nei fondali prospicienti il capo di santa panagia, a nord di siracusa, e più precisamente nell’area antistante la chiesa di san corrado, da cui prende il nome. anche questa cavità si apre sulla parete della scarpata tra 9÷12 m e -20÷22 m sulla quale si affaccia a -20 m di profondità con quattro aperture distinte, due delle quali ampie (fig. 3h) e le rimanenti a sviluppo cunicolare. le volte sono ampie e riccamente incrostate, il fondo è ricoperto da una coltre detritica sciolta a granulometria arenitica nelle porzioni iniziali fino a pelitica in quelle più interne, dove raggiunge uno spessore di circa 2 m. gli ambienti, anche i più interni, sono sufficientemente illuminati e ospitano insediamenti bentonici. l’idrodinamismo all’interno della grotta è spesso elevato per effetto delle molteplici entrate che si aprono nell’ampia prima camera. in più punti della cavità affiorano sorgenti di acqua dolce che ben si manifestano con aloclini marcati che si riscontrano già a partire da pochi metri dagli ingressi. al suo interno la grotta mostra un ampio corredo di speleotemi costituito da stalattiti, stalagmiti, colonne e concrezioni cipollari, ubicati a profondità variabili da -17 m a -12 m. 5. discussione e conclusioni il rilievo topografico di dettaglio dei fondali prospicienti la costa siracusana ha rivelato la presenza di due scarpate sommerse, la più superficiale ubicata a profondità tra -9÷12 m e -20÷22 m, la più profonda tra -20÷25 m e -40÷45 m. l’andamento sub-parallelo alla linea di costa attuale, la batimetria costante, il collegamento con un paleo-livello carsico, nonché la continuità chilometrica della scarpata superiore provano che si tratti di paleo-linee di costa sommerse. la presenza di fig. 4 rilievo planimetrico e sezione longitudinale della grotta delle corvine. planimetric map and longitudinal section of the corvine cave. fig. 5 rilievo planimetrico e sezione longitudinale della grotta di san corrado. planimetric map and longitudinal section of the san corrado cave. g. scicchitano & c. monaco grotte carsiche di chiara origine continentale lungo le due scarpate suggerisce infatti che esse abbiano rappresentato i livelli di base di sistemi paleo-carsici relativi a fasi di stazionamento del livello del mare. la profondità nominale delle due paleolinee di riva viene qui fissata con la base delle scarpate sottomarine, rispettivamente a -20÷25 m e -40÷45 m. considerato il discreto sviluppo, è difficile che le paleo-linee di costa e i relativi sistemi carsici si siano sviluppati durante il breve lasso di tempo della risalita olocenica che è stata piuttosto rapida e non intervallata da stazionamenti del livello del mare (v. lambeck et al., 2004). le due paleo-linee di costa devono essere quindi più antiche e vengono qui riferite ad un generico pleistocene. alcune considerazioni ci permettono di assegnare queste paleo-linee a stazionamenti abbastanza recenti. la buona preservazione delle scarpate, in particolare di quella superiore, suggerisce che esse non abbiano subito l’effetto erosivo di ripetute oscillazioni eustatiche. inoltre dato il modesto tasso di sollevamento tettonico dell’area (0,6 mm /a; bianca et al., 1999), si può supporre che queste linee di costa possano essere riferite agli stazionamenti del mis 3 e che siano state sollevate dalla profondità di circa 40÷60 m che contraddistingue i picchi dello stadio mis 3 (waelbroeck et al., 2002) alla loro attuale profondità nel corso degli ultimi 60÷40 ka. la presenza di speleotemi all’interno di grotte sommerse ha dunque fornito la conferma che i sistemi paleo-carsici collegati con le due paleo-linee di costa si siano sviluppati in ambiente continentale durante il pleistocene superiore per poi essere sommerse e fossilizzate per effetto dalla veloce risalita del mare olocenica (lambeck et al., 2004). la datazione preliminare degli organismi incrostanti prelevati alla base di una stalagmite ubicata all’interno della grotta del plemmirio a -20 m di profondità (dutton et al., in preparazione) indica che l’ultima risalita del livello marino abbia iniziato a sommergere la scarpata superiore circa 8.000 anni fa. al fine di dettagliare con maggiore precisione le variazioni relative del livello del mare e ottenere dati più certi sulla genesi ed evoluzione della grotta e della relativa linea di costa durante il quaternario sono state avviate, in collaborazione con la research school of earth science di canberra–australia, analisi di datazione assoluta, con i metodi u/th e radiocarbonio, su varie porzioni della suddetta stalagmite e di altri speleotemi campionati in grotte carsiche ubicate alla base delle due scarpate sottomarine. la datazione delle concrezioni marine e dei livelli continentali all’interno di speleotemi a livelli marini-continentali (alessio et al., 1994; antonioli et al., 1998) rappresenta infatti un eccellente metodo per la ricostruzione delle variazioni del livello del mare oltre che per lo studio del paleoclima. ringraziamenti si ringraziano i due anonimi referee per i commenti e i suggerimenti che hanno consentito di migliorare il lavoro. si ringraziano inoltre luciano tinè e fabio esposito e tutti i ragazzi della scuola subacquea "punto sub" di siracusa per la collaborazione alle operazioni subacquee. bibliografia a.a-v.v. (1986) carta geologica del settore nordorientale ibleo (sicilia s.e.). s.el.ca., firenze. alessio m., allegri l., antonioli f., belluomini g., improta s., manfra l. & preite martinez m. (1994) – la curva di risalita del mare tirreno negli ultimi 43 ka ricavata da datazioni su speleotemi sommersi e dati archeologici. mem. descr. carta geol. d’it., 52, 261-276. antonioli f., borsato a., frisia s & silenzi s. (1998) l’uso degli speleotemi per ricostruzioni paleoclimatiche e variazioni del l ivello del mare . i l quaternario, 11 (1), 67-78. carbone s., di geronimo i., grasso m., iozzis s. & lentini f. (1982) i terrazzi marini quaternari dell’area iblea (sicilia sud-orientale). c.n.r. – p.f.g. (sottoprogetto neotettonica), contributi conclusvi per la realizzazione della carta neotettonica d’italia, 506, 1-35. di grande a. & rraimondo w. (1982) linee di costa pliopleistoceniche e schema litostratigrafico del quaternario siracusano, geol. romana, 21, 279-309. bianca m. (1999) terrazzi marini e sollevamenti tettonici nel settore orientale del plateau ibleo. boll. acc. gioenia sci. nat., 31 (355), 51-60. bianca m., monaco c., tortorici l. & cernobori l. (1999) quaternary normal faulting in southeastern sicily: a seismic source for the 1693 large earthquake. geophys. j. int. 139, 370 -394. lambeck k., antonioli f., puecell a. & silenzi s. (2004) sea level change along the italian coast for the past 10,000 yrs. quat. sc. rev., 23, 1567-1598. leonardi r. (1994) contributo alla conoscenza delle grotte sommerse della penisola della maddalena (sr). boll. acc. gioenia sci. nat., 27 (348), 599-620. monaco c. & tortorici l. (2000) active faulting in the calabrian arc and eastern sicily . j. of geodynamics, 29, 407-424. monaco c., antonioli f., de guidi g., lambeck k., tortorici l. & verrubi v. (2004) tectonic uplift and sea-level change during the holocene in the catania plain (eastern sicily). quaternaria nova, 8, 171-185. ruggieri r. & amore c. (2000) elementi geostrutturali e paleomorfologici del sistema carsico grotta monello (sicilia sud-orientale). in: atti del i° seminario di studi sul carsismo negli iblei e nell’area sud-mediterranea. speleologia iblea, 8, 75-81. ruggieri r. & grasso m. (2000) caratteristiche stratigrafiche e strutturali dell’altipiano ibleo ragusano e sue implicazioni sulla morfogenesi carsica. in: atti del i° seminario di studi sul carsismo negli iblei e nell’area sud-mediterranea. speleologia iblea, 8, 19-35. waelbroeck c., labeyrie l., michel a., duplessy j.c., mcmanus j.f. lambeck k., balbon e. & labracherie m. (2002) sea-level and deep water temperature changes derived from benthic foraminifera isotopic records. quaternary sc. rev., 21, 295-305. 193 ms. ricevuto il 3 ottobre 2006 testo definitivo ricevuto il 5 dicembre 2006 ms. received: october 3, 2006 final text received: december 5, 2006 grotte carsiche e linee di costa sommerse ... sess 0_retro e indice edi.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 foundation, development and abandoning of a bronze age pile-dwelling (“lucone d”, garda lake) recorded in the palynostratigraphic sequence of the pond offshore the settlement federica badino1, marco baioni2, lorenzo castellano1, nicoletta martinelli3, renata perego4 & cesare ravazzi1 1 c.n.r., istituto per la dinamica dei processi ambientali milano, italy 2 museo archeologico della valle sabbia di gavardo brescia, italy 3 dendrodata – verona, italy 4 ipna basel, switzerland * corresponding author: f. badino <federica.badino@idpa.cnr.it> abstract: badino f. et al., foundation, development and abandoning of a bronze age pile-dwelling (“lucone d” site, garda lake) recorded in the palynostratigraphic sequence of the pond offshore the settlement. (it issn 0394-3356, 2011). the ongoing archaeological excavations at “lucone d” pile-dwelling (garda lake morainic amphitheatre, polpenazze del garda brescia), yielded abundant archaeological artifacts and piles dendrochronologically and/or culturally dated back from 2033±10 to 1800-1900 cal b.c. palynostratigraphic studies focused on the lacustrine-palustrine sequence in the pond facing the settlement. a palynological record at decennial resolution, supported by ams datings and independently correlated to the village history through detection of sharp events, describes the environmental changes at the foundation of the settlement, the development of rural landscape during the two-centuries development of the village, and the abandonment. riassunto: badino f. et al., fondazione, sviluppo e abbandono di un abitato palafitticolo dell'età del bronzo (“lucone d”, lago di garda) nella palinostratigrafia dello stagno adiacente all'insediamento. (it issn 0394-3356, 2011) gli scavi archeologici in corso presso il sito palafitticolo “lucone d” (anfiteatro morenico del lago di garda, polpenazze del garda brescia) hanno restituito una ricca documentazione di materiali archeologici del bronzo antico (circa 20331800 a.c.). gli studi palinostratigrafici si sono concentrati sulla sequenza stratigrafica conservata nello stagno adiacente l’abitato. nel presente lavoro viene brevemente descritta la storia dell’ambiente nelle fasi che precedono la fondazione dell’abitato, durante le sue fasi di vita e nel periodo successivo al suo abbandono. key words: bronze age, pile-dwelling settlement, lucone, pollen analysis, human impact, northern italy parole chiave: età del bronzo, palafitte, lucone, analisi pollinica, impatto antropico, nord italia the former-lake lucone (249 m a.s.l., polpenazze del garda brescia) is located in the western part of the morainic amphitheatre of garda lake (fig. 1), the biggest glacial system in italy. more than fifty lakes were formed in this region during the lateglacial times which evolved as closed lakes (i.e. without an outlet) after deglaciation completed. during the early bronze age (ba) a sudden increase of long-standing (i.e. centennial-standing) lacustrine villages is observed in these small basins, causing a sharp intensification of human impact on the landscape. palaeobotanical and sedimentological studies are particularly fruitful in the sediment archives preserved at these waterlogged sites. the sediments of the lucone basin contain one of the richest holocene archives: preservation of plant remains is excellent and the late holocene stratigraphic sequence is only faintly damaged by peat quarrying or agricultural works. archaeological findings are distributed in five different areas along lakeshores (lucone a-e, baioni & bocchio, 2004). two pile-dwellings were excavated (lucone a and lucone d): the lithic and bronze assemblages referred them to early and middle ba, guerreschi (1980-1981), bocchio (1985–1988). a more accurate dating is provided by a dendrochronological investigation carried out at lucone d on 50 quercus sp. posts, which added chronological precision to the archaeological sequence, restricted to early ba, martinelli (1996). we present here the first results of a palynostratigraphic investigation of a pond record offshore to the village (fig. 2). a trench has been digged precisely 13 m from the limit of the innermost stilt houses, the latter marked by waterlogged dump cumulus,. three radiocarbon ams ages were obtained all from terrestrial plants and calibrated using calib software (v. 6.0, queen’s university belfast) with the intcal09 calibration curve. the age-depth model is also supported by the event-correlation technique. three main events provide a chronological 177 179 178 fig. 1, the lucone basin (polpenazze del garda, brescia) is located in the western part of the morainic amphitheatre of garda lake. il bacino del lucone (polpenazze del garda, brescia) è localizzato nel settore occidentale dell’anfiteatro morenico del lago di garda. fig. 2, summary pollen curves and general evolution of “lucone d” pile-dwelling. the settlement foundation is marked by a fire and correlated to a sudden reduction in forest cover and cereals % pollen curve expansion. diagramma a curve polliniche selezionate ed evoluzione del villaggio palafitticolo ”lucone d”. la fondazione dell’abitato è segnata da un incendio correlato alla deforestazione e all’espansione della curva pollinica percentuale dei cereali. f. badino et al. 179 ms. received: testo ricevuto il constrain to the pollen record independent from ams dating. first, the village foundation is recognized in the pollen stratigraphy through detecting a sudden deforestation and coeval cereal fields expansion. therefore, we attributed its dendro-chronological age (2033 ± 10 yr cal bc) to the relevant pollen layer. the village restoring at the dendrochronological age 1980 ± 10 yr cal bc is also detected in the pollen record. finally, the village abandoning is registered as a relatively sharp event in the pollen record, and may be given its cultural age (1850 ± 50 cal bc). thus, we obtained a robust chronology which allowed for a quasi-decennial resolution between samples. the age-depth model highlights an extremely high sedimentation rate during the phase 1 (almost 1 m of compacted organic in 50 years). this is explained by to dump discharge in the pond. before the settlement, the area was covered by dense thermophilous broad-leafed forests (quercus, carpinus betulus, fagus, ulmus). the finding of isolated cereals and plantago lanceolata pollen grains supports the occurrence of sporadic human clearings in the copper age. the village foundation is documented by a sudden reduction in forest cover, a strong increase of microscopic charcoal and the synchronous spread of several anthropogenic indicators (cerealia, plantago lanceolata, rumex acetosa, trifolium). the settlement phase is palynologically two-folded, in agreement with archaeological and dendrochronological data, bocchio (1988), martinelli (1996). during the oldest settlement phase (phase 1), the pollen composition pattern suggests a strong human impact in with high and stable extent of cereal fields, pastures and orchards. the beginning of the subsequent settlement phase (2) is marked by pollen changes indicating reduction of cereal fields and also involves forest recolonization. this is correlated to the event of houses restoring, dendro-cronologically dated to around 1970 bc, after an extended fire event well documented in the excavation area. the final settlement abandoning is shown by a sudden disappearance of cereal pollen and an increasing trend of forest recolonization (quercus, corylus, fagus, carpinus betulus). signs of human activity are recorded after the abandoning of lucone d settlement, during the subsequent early-middle bronze age and the iron age as well. references baioni m. & bocchio g. (2004) distribuzione spaziale nel bacino del lucone di polpenazze (bs) tra neolitico ed et`a del bronzo. recenti ricerce. poster presented at wetland economies and societies. zurich (switzerland), march 10–13. bocchio g. (1985–1988) saggio stratigrafico presso lucone d. polpenazze del garda (bs). annali del museo gavardo 16, 15-43 cremaschi m. (1987) paleosols and vetusols in the central po plain (northern italy). phd thesis. unicopli, milano. guerreschi g. (1980-1981) la stazione preistorica del lago lucone (brescia) scavi 1965–1971. recenti ricerce. annali del museo gavardo 14, 7-78. martinelli n. (1996) datazioni dendrocronologiche per l’età del bronzo dell’area alpina. in: ranndsborg k (ed) absolute chronology: archaeological europe 2500–500 bc. acta archeologica supplementa 67, 315-326. venzo s. (1965) rilevamento geologico dell’anfiteatro morenico frontale del garda dal chiese all’adige. mem. soc. it. sc. nat., 46, 1-82. foundation, development and abandoning of a ... january 15, 2011 15 gennaio 2011 imp.montana& definizione composizionale delle “argille ceramiche” presenti nella sicilia nord-occidentale: inquadramento geologico e ricadute di carattere archeometrico g. montana 1, a. caruso 2, a.t. lavore 1, a.m. polito 1 & a. sulli 2 1 dipartimento di chimica e fisica della terra (c.f.t.a.) – università degli studi di palermo (gmontana@unipa.it) 2 dipartimento di geologia e geodesia università degli studi di palermo riassunto: g. montana, a. caruso, a.t. lavore, a.m. polito & a. sulli, definizione composizionale delle “argille ceramiche” presenti nella sicilia nord-occidentale: inquadramento geologoco e ricadute di carattere archetettonico. (it issn 0394-3356, 2007). il presente studio intende fornire un primo contributo alla caratterizzazione composizionale e tecnologica dei depositi argillosi ubicati nella sicilia nord-occidentale, riferibili a ben precise unità stratigrafiche, per i quali è stato dimostrato, o è stato quantomeno ipotizzato, lo sfruttamento, nei secoli passati, come materia prima da impiegare nel processo di manifattura ceramica. pertanto, le argille studiate sono state selezionate sulla base di evidenze geologiche, ma, al tempo stesso, anche archeologiche e etnografiche, ponendo un’attenzione maggiore su quei materiali che, anche grazie alle loro qualità specifiche, siano stati maggiormente apprezzati ed utilizzati nella tradizione ceramica locale. la caratterizzazione composizionale delle argille oggetto di studio è stata fatta con l’obiettivo di iniziare a costruire una banca dati che possa essere in un futuro prossimo funzionale e decisiva per l’identificazione dei cosiddetti “gruppi di riferimento” nei più importanti contesti archeologici presenti nell’area studiata, per cui è stata dimostrata (ritrovamento di fornaci e altre strutture connesse alla manifattura), ovvero ipotizzata la localizzazione di un centro produttivo. un certo numero di campioni rappresentativi (46) è stato prelevato dalle quattro formazioni contenenti argille, che affiorano nella sicilia nord-occidentale considerabili almeno potenzialmente idonee alla manifattura ceramica,: 1) argille di ficarazzi (pleistocene); 2) formazione terravecchia (miocene superiore); 3) flysch numidico (oligocene superiore miocene inferiore) 4) argille varicolori (cretaceo superiore oligocene inferiore). innanzitutto i sopraccitati materiali sono stati attentamente descritti dal punto di vista geologico e biostratigrafico, quindi sono state determinate, discusse e confrontate le caratteristiche tessiturali (distribuzione granulometrica), mineralogiche (analisi per diffrattometria a raggi x) e chimiche (analisi per fluorescenza a raggi x). inoltre, per due tipologie di materiale, per cui è già stato dimostrato l’utilizzo ceramico in importanti casi di studio di interesse archeologico e storico (argille di ficarazzi e formazione terravecchia), è stato simulato in laboratorio un ciclo produttivo completo (impasto e cottura). questo con l’obiettivo di determinare parametri specifici come il comportamento plastico, ritiro lineare e colore in seguito ad essiccamento e cottura, caratteristiche tessiturali e composizionali rilevabili dall’esame di sezioni sottili al microscopio polarizzatore. tutti questi parametri possono, infatti, essere utilizzati per ricostruire il livello tecnico degli antichi cicli produttivi (eventuali trattamenti preliminari, procedure di lavorazione e condizioni di cottura) e per la determinazione di provenienza di reperti di dubbia attribuzione. infine, con l’intento di avere una prima verifica di questo approccio, è stato effettuato un confronto petrografico e chimico tra le argille mioceniche e pleistoceniche, ossia le presunte materie prime, ed alcune classi di manufatti ceramici prodotti localmente in varie epoche, dall’età arcaica a quella classico ellenistica e persino nel periodo barocco. i risultati ottenuti sono accettabili ed incoraggiano il proseguimento della ricerca. abstract: g. montana, a. caruso, a.t. lavore, a.m. polito & a. sulli, geological background and compositional characterization of “ceramic clay” from north-western sicily: archaeometric feed-back. (it issn 0394-3356, 2007). this paper deals with the compositional and technological characterization of clayey materials, belonging to specific stratigraphic units, which are suspected to have been exploited (in the past centuries) for the traditional ceramic manufacture in north-western sicily. the studied clays were selected on the basis of geological, archaeological and ethnographic evidences testifying, in several cases, a longestablished use for local ceramic manufacture. the compositional characterization of raw clays has been used to start off a date base which should be functional for the identification of “reference groups” in several archaeological contexts localized in the studied area which are considered to be production centres. a number of representative samples (46) was collected from different clayey formations cropping out in north-western sicily: 1) ficarazzi clays (pleistocene); 2) terravecchia formation (upper miocene); 3) flysch numidico (upper oligocene lower miocene) 4) argille varicolori (upper cretaceous lower oligocene). in a first phase, these materials were carefully described from a geological and stratigraphic point of view. after that, textural (grain size distribution), mineralogical (xrd) and chemical (xrf) characteristics of the clay samples were carried out and discussed. experimental mouldings and firings on two selected clay types from the above mentioned units, already documented to have been used as raw materials in several archaeological and historical important case studies, were also performed. this has been made in order to simulate a production cycle and to recognize some specific parameters such as plastic behaviour, linear shrinkage, colour and petrographical appearance in thin section under the polarizing microscope. these parameters can be directly used to infer ancient manufacture techniques and firing conditions as well as for provenance determination of doubtful attributed archaeological artefact. for testing out this approach an exemplificative compositional comparison between the miocene and pleistocene clays (the believed raw materials) and some ceramic class locally produced during archaic and classichellenistic age or even in baroque period has been made. acceptable results have been obtained which encourage us to pursue this research. parole chiave: sicilia, materie prime argillose, produzione ceramica, archeometria. keywords: sicily, clayey raw materials, ceramic production, archaeometry, foraminifera. il quaternario italian journal of quaternary sciences 19(2), 2006 279-298 280 g. montana et al. 1. obiettivi ed approccio metodologico la predisposizione geologica della sicilia, molto ricca di terreni argillosi, ha certamente contribuito sin dalla più remota antichità allo sviluppo di una ben radicata tradizione ceramica; attività, questa, che risulta comprovata dal ritrovamento, in buona parte dei siti archeologici dell’isola, di importanti strutture produttive rappresentate da fornaci, vasche di decantazione, accumuli di materia prima, scarti di lavorazione. lo sviluppo della ricerca archeometrica in questi ultimi anni ha posto in chiara evidenza che lo studio petrografico e chimico dei materiali ceramici rinvenuti in un dato contesto territoriale può contribuire in modo determinante ad attestare con attendibilità le produzioni locali, distinguendole dalle importazioni e, conseguentemente, consentire di localizzare le vie di circolazione dei reperti ricavando notevoli ricadute in ambito archeologico ed, in particolare, nella ricostruzione storica e socio-economica delle antiche comunità (hughes, m.j., 1981; peacock, 1982; fulford & peacock, 1984; rice, 1987; lindahl & stilborg, 1995; stark et al., 2000). ancora più recentemente si è incominciata a sviluppare una linea di ricerca che intende affiancare alle analisi dei reperti ceramici la caratterizzazione completa delle materie prime argillose presenti nello stesso territorio (kilikoglou et al., 2002; alaimo & montana 2003). si ritiene infatti che il confronto tra manufatti ceramici e potenziali materie prime possa contribuire non poco a ricostruire con maggiore oggettività il livello tecnologico raggiunto dagli antichi cicli produttivi (eventuali trattamenti preliminari, procedure di lavorazione e condizioni di cottura), oltre a consentire e/o semplificare la determinazione di provenienza di reperti di dubbia attribuzione e la circolazione dei manufatti in contesti territoriali relativamente circoscritti in dati orizzonti cronologici. il presente studio si propone, innanzitutto, di definire preliminarmente le caratteristiche tessiturali e composizionali delle argille che affiorano nella sicilia nordoccidentale, di potenziale interesse ai fini della produzione ceramica antica. tali argille, in primo luogo, sono inquadrate litostratigraficamente e caratterizzate dal punto di vista biostratigrafico, per lo più utilizzando dati di letteratura, al fine di un eventuale futuro confronto con il contenuto fossilifero dei reperti ceramici. in particolare, la ricerca intrapresa intende conseguire i seguenti obiettivi a breve e a medio termine: 1) avviare l’acquisizione di dati che siano funzionali alla realizzazione di una vera e propria banca dati delle “argille ceramiche” locali, che possa consentire di definire gli aspetti tecnologici connessi all’attività di manifattura ceramica, differenziati per classe tipologica, destinazione d’uso dell’oggetto e per contesto cronologico. 2) attestare i centri di manifattura nel territorio oggetto di studio (sicilia nord-occidentale) ed individuare dei criteri oggettivi per distinguere i prodotti locali dalle importazioni attraverso il confronto tra le “potenziali” materie prime argillose e le varie classi di reperti ceramici provenienti da scavi archeologici o anche da complessi architettonici di interesse storico-artistico relativamente più recenti. l’approccio metodologico e le tecniche analitiche utilizzate in questo studio si avvalgono dell’approccio teorico e delle conoscenze sperimentali recentemente maturate nell’ambito di un vasto progetto internazionale1, finalizzato allo studio archeometrico di determinate classi di ceramica archeologica e di alcune materie prime argillose utilizzate per la produzione in ambito mediterraneo (italia, spagna, grecia). le materie prime da analizzare sono state individuate sulla base di accurate indagini preliminari sia a carattere prettamente geologico che di tipo etnografico (attraverso acquisizione di dati sul processo produttivo ceramico così come avveniva nei secoli passati) effettuate capillarmente nel territorio oggetto di interesse, considerando, al tempo stesso, la loro importanza ai fini degli studi archeologici ed archeometrici (attraverso la consultazione dei dati inerenti alle aree con maggiore densità di siti archeologici così come riportate nelle “linee guida del piano territoriale paesistico regionale” edite dalla regione siciliana nel 1999). i campioni rappresentativi delle formazioni argillose individuate sono stati prelevati in affioramento o, più raramente, da fronti di cava. si è avuto cura di effettuare i prelievi quanto più possibile in prossimità degli antichi insediamenti ove si suppone che le stesse argille siano state impiegate, ovvero ad una distanza da essi ragionevole, tenendo in considerazione le difficoltà oggettive che aveva il trasporto di tali materiali nei secoli passati. inoltre, la raccolta dei campioni è stata pianificata per cercare di mettere in evidenza eventuali markers composizionali tra formazioni affioranti nella stessa area ed anche la variabilità nell’ambito di una stessa formazione argillosa tra base e tetto dell’affioramento o in aree tra loro distanti (da pochi chilometri ad alcune decine). i markers composizionali sono rappresentati dai minerali e dai frammenti litici che caratterizzano la componente sabbiosa di ogni singola formazione argillosa, la cui natura ed abbondanza relativa si determina, fondamentalmente, mediante l’esame petrografico in sezione sottile di provini sperimentali cotti a varie temperature. chiaramente, anche la composizione chimica “bulk”, che, in genere, rispecchia molto fedelmente l’abbondanza relativa e la composizione mineralogica della frazione sabbiosa, fornisce criteri distintivi molto efficaci i quali, tuttavia, per una corretta interpretazione, spesso necessitano di una calibratura con i dati minero-petrografici. inoltre, un supporto complementare assai importante (a volte decisivo) alla ricerca di caratteristiche distintive tra materie prime o tra manufatti ceramici con esse realizzati può essere ottenuto mediante la definizione accurata della microfauna calcarea (foraminiferi), specie in aree produttive dove si poteva attingere a più materie prime, poco differenziabili per via petro-chimica. infatti, non così raramente come si potrebbe pensare, specie nei manufatti ceramici di grosse dimensioni (come ad esempio le anfore da trasporto), si trovano parti in cui la temperatura raggiunta 1geopro european tmr network 1998-2001 (erbfmrxct980165) “integrating geochemical and mineralogical techniques: a new approach to raw materials and archaeological ceramic provenance” (coordinator: university of sheffield uk; other partecipants: national centre for scientific research “demokritos” gr, rheinische friedrich wilhelms universität bonn de, universitat de barcelona es, università degli studi di palermo it, the notthingam trent university uk). e/o particolari condizioni di cottura hanno preservato in tutto o in parte i foraminiferi, che, pertanto, individuati nelle osservazioni in sezione sottile o al sem, consentono il più delle volte di circoscrivere cronostratigraficamente l’argilla usata quale materia prima (quinn et al., 1998; 1999 a; 1999 b). 2. campionamento e tecniche di analisi sulla base dei criteri sopra descritti sono stati prelevati 46 campioni di argilla, ritenuti rappresentativi delle materie prime argillose affioranti nella sicilia nordoccidentale, potenzialmente utilizzate per la manifattura ceramica a partire dalla preistoria sino al secolo scorso. questi campioni sono riconducibil i a quattro formazioni: argille di ficarazzi (pleistocene inferioremedio), argil le della formazione terravecchia (tortoniano superiore-messiniano inferiore), argille del flysch numidico (oligocene superiore-langhiano) e argille varicolori (cretaceo-oligocene inferiore). le argille campionate sono state tutte confrontate in termini di distribuzione granulometrica, di composizione mineralogica e composizione chimica. inoltre, limitatamente alle argil le mioceniche (formazione terravecchia) e a quelle pleistoceniche (argille di ficarazzi), che si ritiene abbiano avuto un utilizzo più rilevante in termini sia qualitativi che quantitativi, è stato simulato in laboratorio un ciclo completo di lavorazione artigianale. negli impasti sperimentali sono state determinate alcune caratteristiche tecnologiche (plasticità, ritiro lineare, colore) prima e dopo i cicli di cottura effettuati in atmosfera ossidante ed a varie temperature. inoltre sono state definite anche le caratteristiche petrografiche desunte dall’esame al microscopio polarizzatore delle sezioni sottili dei provini cotti a 300 ed a 950°c, al fine di rendere il confronto maggiormente sistematico ed omogeneo. oltre la metà delle argille analizzate appartiene alla formazione terravecchia (27 campioni). questa scelta è stata indotta dall’estensione degli affioramenti di questa formazione nell’area in esame e, soprattutto, dalle numerose testimonianze ricavate dalla ricerca etnografica circa l’uso secolare che è stato fatto di queste argille nella manifattura ceramica locale (soprattutto nell’area compresa tra termini imerese e collesano da cui proviene il maggior numero di campioni). di contro, i campioni rappresentativi delle argille di ficarazzi sono in numero decisamente inferiore (4). questa limitatezza nei prelievi è dipesa dalla odierna oggettiva rarità degli affioramenti. infatti, gli affioramenti il cui sfruttamento nei secoli passati è ampiamente documentato (cipolla, 1931) sono stati totalmente assorbiti dalla incontrollata espansione edilizia di palermo e dei piccoli centri abitati limitrofi avvenuta nell’ultimo trentennio. anche il numero dei campioni prelevati dal flysch numidico (8) e dalle argille varicolori (7) è più basso rispetto alla formazione terravecchia, tuttavia, in questo caso, la scelta di limitare momentaneamente i prelievi è stata fatta intenzionalmente. infatti, per questi materiali non è stato ancora dimostrato, nel territorio in oggetto, un utilizzo per la produzione di forme vascolari e/o altri manufatti di qualità medio-alta; semmai, al contrario, un impiego sporadico per la manifattura di laterizi comuni (mattoni da costruzione). pertanto sono da considerare di rilevanza 281definizione composizionale delle “argille ceramiche” ... minore in termini di ricaduta storico-artistica e pressoché nulla in termini di ricaduta archeologica. l’analisi granulometrica dei materiali argillosi è stata realizzata per via umida applicando la legge di stokes, dopo averli essiccati (a temperatura ambiente), quartati e decoesionati. essa ha permesso di ottenere, per ogni campione, la percentuale in peso delle frazioni dimensionali principali: sabbia (2÷0.06 mm), silt (0.06÷0.002 mm) ed argilla (granuli con diametro inferiore a 0.002 mm). la composizione mineralogica è stata indagata attraverso analisi per diffrattometria a raggi x (xrd) mediante un diffrattometro philips x’pert. le riprese diffrattometriche sul campione totale sono state effettuate su preparati, preventivamente essiccati e macinati in un mortaio di agata, disorientati per caricamento laterale. sono state applicate le seguenti condizioni operative: intervallo angolare 2°÷60° 2θ; velocità del goniometro 2° 2θ /min (step size 0.020; time per step 0.50; scan speed 0.04; detector reference slit 0.2 mm); radiazione cukα (40 kv, 40 ma), monocromatore a grafite. le stime di abbondanza relativa delle fasi mineralogiche individuate sono state effettuate in base all’intensità dei picchi, a loro volta determinate in base alle aree dei riflessi specifici e moltiplicate per i relativi fattori di correzione, in accordo a laviano (1987). il riconoscimento e la stima semiquantitativa delle abbondanze dei minerali argillosi (caolinite, illite, clorite e smectite) è stata effettuata mediante riprese diffrattometriche eseguite su preparati isorientati. una sospensione acquosa della frazione inferiore a 0.002 mm è stata omoionizzata con 6g di mgcl2 6h2o per 500 ml in bagno ad ultrasuoni e successivamente centrifugata a 4000 rpm (per 15 minuti). il campione è stato quindi depositato mediante pipetta su supporti in vetro e in refrattario, e lasciato essiccare. esso è stato successivamente esposto ai vapori di glicole etilenico (in stufa a 60°c per due ore) e a vari trattamenti termici (180°c e 600 °c), quindi sottoposto ai raggi x. per le analisi è stato utilizzato un diffrattometro philips x’pert, radiazione cukα (40 kv, 40 ma), monocromatore a grafite, indagando un intervallo angolare compreso tra 2° e 30° 2θ, velocità del goniometro 1° 2θ/min (step size 0.010; time per step 0.50; scan speed 0.02; detector reference slit 0.2 mm). sugli spettri così ottenuti, allo scopo di effettuare una stima semiquantitativa delle abbondanze relative dei soli minerali argillosi (espressi come percentuali di illite, smectite, caolinite e clorite) sono state misurate le aree di riflessi specifici, successivamente trasformate in percentuali di abbondanza attraverso appropriati fattori di correzione e formule (metodo di shaw et al., 1971 modificato da laviano, 1987). l’analisi chimica, effettuata mediante spettrometria dei raggi di fluorescenza (xrf, spettrometro philips pw 1400), ha permesso di ricavare le concentrazioni degli elementi maggiori (si, ti, al, p, fe, mg, mn, ca, na, k) espressi in termini della percentuale in peso degli ossidi costituenti normalizzati rispetto alla perdita per calcinazione (loi) e, per la grande maggioranza dei campioni, anche degli elementi in traccia (v, cr, co, ni, cu, zn, rb, sr, zr, ba, la, ce) espressi in termini di parti per milione (ppm). una descrizione dettagliata delle procedure adottate, che sono state specificamente standardizzate per l’analisi di ceramica e di materie prime argillose, è riportata in una recente pubblicazione 282 (hein et al., 2002). i risultati dell’analisi chimica sono stati elaborati anche con metodi di statistica multivariata (analisi discriminante) allo scopo di verificare quantitativamente la consistenza e la significatività dei “gruppi chimici” dandone opportuna rappresentazione grafica in uno spazio bidimensionale (buxeda, 1999). inoltre, come già accennato, è stata effettuata una simulazione sperimentale di un ciclo di produzione limitatamente ai materiali della formazione terravecchia ed alle argille di ficarazzi. sugli impasti sperimentali sono stati calcolati gli indici di plasticità e liquidità facendo riferimento alla normativa italiana cnr-uni 10014. con l’argilla allo stato plastico sono stati modellati dei provini parallelepipedi (con dimensioni pari a circa 40x20x8 mm), sottoposti, dopo essere stati essiccati a 100 °c, a sequenze di cottura in muffola (atmosfera ossidante) a diverse temperature (300 °c e 950 °c con permanenza alla temperatura di picco sempre pari a 3 ore) per la determinazione del ritiro lineare in cottura (rlc) e la produzione di sezioni sottili da descrivere al microscopio polarizzatore (leica lsp equipaggiato con fotocamera digitale leica dc200 interfacciata ad un pc). 3. inquadramento geologico e caratterizzazione stratigrafica delle argille studiate nel territorio siciliano gli affioramenti argillosi sono piuttosto diffusi e conferiscono un aspetto prevalentemente collinare a gran parte dell’isola. in sicilia le unità litostratigrafiche che sono costituite totalmente o in parte da depositi argillosi abbracciano praticamente tutto l’intervallo temporale nel quale si sviluppano le successioni sedimentarie siciliane, che va dal trias superiore (con le argille della fm. mufara) all’olocene. di seguito viene effettuato un inquadramento geologico delle potenziali fonti di materie prime argillose utilizzabili per la produzione ceramica che affiorano nella sicilia nord-occidentale. in figura 1 sono riportati gli schemi crono-bio-litostratigrafici in cui si collocano le unità campionate: argille di ficarazzi (fig. 1a), formazione terravecchia (fig. 1b), flysch numidico ed argille varicolori (fig. 1c). 3.1 argille di ficarazzi l’area di affioramento di tale formazione è collocata nel settore costiero a se di palermo. il campionamento delle argille di ficarazzi è stato effettuato in c.da olivella, nelle immediate vicinanze del sito archeologico di solunto (prima insediamento fenicio-punico e poi romano), a ficarazzi presso la foce dell’eleuterio e in c.da acqua dei corsari a palermo. le argille di ficarazzi (seguenza, 1873; brugnone, 1877) sono argille sabbiose, silt e sabbie fini, di colore azzurro-grigio se inalterate, con rare intercalazioni di calcisiltiti e calcareniti. questi depositi vengono datati al siciliano (ruggeri, 1979). i dati provenienti dal sondaggio a carotaggio continuo ficarazzi 1 hanno permesso di definire nel dettaglio la biostratigrafia delle argille del siciliano (ruggieri & sprovieri,1977; di stefano & rio, 1981; buccheri, 1984). lo spessore è di qualche decina di metri con un massimo, rinvenuto in perforazione, di circa 80 metri. nel sottosuolo essa si estende quasi uniformemente nel settore meridionale ed orientale della piana di palermo. la macrofauna ad ospiti nordici della parte sommitale di queste argille è data dai molluschi arctica islandica, mya truncata, panopea norvegica, buccinum undatum. l’associazione a foraminiferi è generalmente ben diversificata ed in un buono stato di conservazione, anche se in molti livelli è meno ricca dal punto di vista fossilifero con aumento delle concentrazioni di granuli detritici di natura silicatica come quarzo monocristallino, selce e feldspati. i foraminiferi bentonici sono nettamente dominanti con rapporto p/b compreso tra 5÷15%, valore tipico della zona di circalitorale superiore (80÷100 m di profondità). l’associazione a foraminiferi planctonici è caratterizzata dalla presenza di globorotalia inflata, globorotalia truncatulinoides excelsa, globigerinoides ruber, globigerina bulloides, neogloboquadrina pachyderma, turborotalita quinqueloba, globigerinita glutinata. tra i foraminiferi bentonici sono frequenti uvigerina peregrina, bolivina dilatata, melonis padanum, hyalinea baltica. quest’ultima specie insieme a globorotalia truncatulinoides excelsa permettono di “datare” questi sedimenti attribuendoli all’intervallo siciliano. 3.2 argille della formazione terravecchia l’area di affioramento di questa formazione si estende nella sicilia centrale ed occidentale. il nostro campionamento ha interessato le località del vallone garbinogara nel comune di termini imerese (nei pressi dell’importante sito archeologico di himera); nel territorio comunale di castellana sicula in c.da ponte e c.da donalegge (nei pressi del sito archeologico di muratore); polizzi generosa in c.da guglia. la formazione terravecchia (tortoniano superiore-messiniano inferiore), istituita da schmidt di friedberg (1964; 1965), è costituita da una successione prevalentemente terrigena; comprende depositi terrigeni e terrigeno-carbonatici con differenti granulometrie che permettono di separare la formazione in unità di rango inferiore. la formazione comprende dal basso verso l’alto: 1) conglomerati rossi e giallastri ad elementi carbonatici, arenacei e litici di granulometria variabile, con matrice sabbiosa e sabbie quarzose con intercalazioni di conglomerati, con spessori massimi di 150 m; 2) sabbie ed arenarie quarzose di colore grigio-giallastro che si interdigitano, verso l’alto, con 3) argille, siltiti argillose e argille sabbiose (250 m di spessore), con abbondanti clasti di taglia arenitica, in cui il quarzo è in genere dominante con mica e feldspato comuni. la formazione terravecchia affiora estesamente anche nella sicilia centrale e centro-meridionale (nel cosiddetto bacino di caltanissetta). la formazione presenta spessori variabili compresi tra alcune centinaia di metri e quasi 2000 m. l’attribuzione stratigrafica dei campioni di questa formazione è spesso problematica. rari sono infatti i livelli contenenti una associazione significativa a plancton calcareo. spesso si tratta infatti di depositi di mare basso (ambiente deltizio), con abbondanti foraminiferi bentonici e abbondante contenuto clastico. l’associazione a foraminiferi è qualitativamente mediocre o scarsa, caratterizzata da preservazione dei gusci da discreta a pessima, con cattiva preservazione. frequenti sono i foraminiferi rimaneggiati di sedimenti più antichi. l’associazione a foraminiferi planctonici in posto anche se scarsa è tipica delle biozone a g. montana et al. 283 fig. 1 (a) schema crono-bio-litostratigrafico del pliocene/pleistocene; per le biozone a foraminiferi platonici sono stati utilizzati gli schemi proposti da cita & gartner (1973) emendati da sprovieri (1993). (b) schema crono-bio-litostratigrafico dell’intervallo compreso tra la parte alta del serravalliano e la parte bassa del messiniano; per le biozone a foraminiferi platonici sono stati utilizzati gli schemi proposti da sprovieri et al. (1996; 2002). (c) schema esemplificativo crono-bio-litostratigrafico dell’intervallo compreso tra la parte del cretaceo inferiore e il langhiano. per i dati sulle comparse e scomparse dei foraminiferi platonici sono stati utilizzati gli schemi proposti da bolli & sounders (1985). (a) litho-bio-chronostratigraphic sketch of the plio-pleistocene time interval; for the planktonic foraminifera biozone the schemes proposed in cita & gartner (1973) and modified by sprovieri (1993) have been used. (b) litho-bio-chronostratigraphic sketch for the late serravallian-early messinian time interval; the schemes proposed by sprovieri et al. (1996; 2002), have been used for the planktonic foraminifera biozone. (c) simplified litho-bio-chronostratigraphic sketch of the early cretaceous-langhian time interval. for occurrences and disappearances of planktonic foraminifera schemes proposed by bolli & sounders (1985) have been used. definizione composizionale delle “argille ceramiche” ... 284 globigerinoides obliquus extremis, globorotalia suterae e globorotalia conomiozea che secondo lo schema biostratigrafico proposto da sprovieri et al., (1996), ricoprono la parte medio-alta del tortoniano e la parte bassa del messinano. nell’associazione sono frequenti orbulina universa, neogloboquadrina acostaensis, globorotalia menardii. i foraminiferi bentonici sono dominanti rispetto ai planctonici con un rapporto p/b che oscilla tra 10÷30% in cui ammonia beccarii, ammonia punctatogranosa sono dominanti seguiti, in percentuale di frequenza da florilus boueanum e elphidium crispum. 3.3 argille del flysch numidico in totale sono stati prelevati 8 campioni. le località di campionamento sono ubicate nei territori comunali di termini imerese (3 campioni) e caccamo (3 campioni), in punti più o meno prossimi al sito greco-coloniale di himera e nel territorio di isnello (2 campioni). al flysch numidico (oligocene superiore-miocene inferiore) appartengono le successioni clastico-terrigene, per lo più torbiditiche, che costituiscono le coperture, in gran parte scollate dal loro originario substrato mesozoico-terziario, dei domini imerese e panormide e di domini più interni (sicilidi). affiora estesamente in tutta la sicilia centro-settentrionale, ma si riconosce in lembi, con tipologie in parte differenti, anche nella sicilia occidentale (catalano & d’argenio, 1982; catalano et al., 2000; 2002) e centro-meridionale. in sottosuolo raggiunge gli spessori più elevati, per imbricazioni tettoniche, nella sicilia centro-orientale (bianchi et al., 1989; bello et al., 2000). su base lito e biostratigrafica si possono distinguere tre unità litostratigrafiche (catalano et al., 2005): formazione di portella colla (oligocene superiore-aquitaniano), formazione geraci siculo (aquitaniano-burdigaliano) e formazione tavernola (burdigaliano-langhiano), generalmente eteropiche tra di loro. la formazione portella colla è costituita da argilliti di colore bruno o color tabacco, talora manganesifere, a cui si intercalano strati centimetrici di siltiti ed arenarie fini, e talora, livelli di megabrecce carbonatiche. nella parte inferiore sono presenti lenti bioclastiche con macroforaminiferi (nummuliti). lo spessore è di circa 500 m. la formazione geraci siculo è rappresentata da potenti banchi di quarzareniti con intercalazioni argil l i t iche. la formazione tavernola (marchetti, 1956) è costituita da marne e argilliti grigioverdi o biancastre, intercalate a livelli arenacei quarzosi e ricchi di granuli glauconitici, con una maggiore percentuale della componente carbonatica rispetto agli altri litotipi. lo spessore supera i 200 m. questi depositi sono stati descritti nei monti nebrodi (accordi, 1958; colacicchi, 1958), nelle madonie (ogniben, 1960; broquet, 1968) e nei monti di palermo (caflisch, 1966). il contenuto paleontologico degli intervalli marnosoargillosi è dato da radiolari, spicole di spugna, foraminiferi planctonici e bentonici, rari nannofossili calcarei. l’associazione della fm di portella colla è essenzialmente dominata da foraminiferi bentonici agglutinanti tra cui ammodiscus e glomospira, che meglio si adattano ai sedimenti torbiditici. l’associazione della formazione tavernola è caratterizzata dalla discreta presenza di foraminiferi planctonici che permettono una buona datazione stratigrafica di questi sedimenti. nella porzione inferiore la preservazione dei gusci dei foraminiferi è generalmente cattiva mentre l’associazione è dominata dalla presenza di globorotalia opima nana, cataspidrax dissimilis, globoquadrina dehiscens che indicano un età riferibile all’aquitaniano (iaccarino, 1985). i sedimenti più abbondanti sono però rappresentati da quelli del burdigaliano inferiore con rari individui di globigerinoides altiapertura, neogloboquadrina praecontinuosa, cataspidrax dissimilis (biozona cataspidrax dissimilis, (iaccarino, 1985), inoltre sono abbondanti gli individui di paragloborotalia acrostoma nei livelli del burdigaliano. la porzione più alta di questi sedimenti è caratterizzata dalla presenza di globigerinoides trilobus (biozona a globigerinoides trilobus) che indica il burdigaliano superiore (iaccarino, 1985). in rari campioni della formazione tavernola si ritrova praeorbulina glomerosa, la cui presenza permette di attribuire i sedimenti al langhiano inferiore (biozona praeorbulina glomerosa). 3.4 argille varicolari le località sottoposte a campionamento sono ubicate a c.da pantaleo (castellana sicula), c.da torre (polizzi generosa) ed a c.da cozzo del drago (himera), tutte nelle immediate vicinanze di importanti e documentati centri di produzione ceramica (polizzi) o di insediamenti di età arcaica e/o romana (himera e castellana sicula). le argil le varicolori (cretaceo superioreoligocene inferiore) sono costituite da argille e marne varicolori rosso-verdastre con intercalazioni centimetriche di livelli silicizzati verdi, fortemente scagliettate e tettonizzate. questi depositi afferiscono al dominio paleogeografico sicilide (ogniben 1960), che si sviluppava presumibilmente su un originario basamento cristallino di tipo oceanico, dal quale attualmente risulta totalmente scollato. gli eventi deformativi che portarono alla messa in posto dell’edificio tettonico siciliano coinvolsero per prime proprio le unità sicilidi (miocene inferiore-medio), che si trovano nelle posizioni più elevate della pila tettonica. questi terreni, conosciuti anche con il nome di argille scagliose, sono diffusi nei settori orientali della sicilia, ma affiorano estesamente anche nella sicilia centro-occidentale e in lembi inglobati all’interno dell’edificio tettonico nella sicilia centromeridionale. in affioramento le argille varicolori sono spesso associate, con rapporti tettonici complessi, alle unità del flysch numidico. il contenuto micropaleontologico è mediamente caratterizzato dalla presenza di numerose specie di foraminiferi bentonici e planctonici che dal punto di vista stratigrafico ricoprono un intervallo che va dal cretaceo superiore sino all’oligocene inferiore. in alcuni particolari livelli del cretaceo superiore e dell’oligocene inferiore sono presenti anche abbondanti radiolari. nelle argille varicolori, a causa della forte tettonizzazione che hanno subito, è molto difficile ricostruire una stratigrafia continua che ricopra il cretaceo superiore-oligocene inferiore ed infatti l’intervallo stratigrafico appare spesso lacunoso. in particolare nella parte stratigraficamente più antica del cretaceo superiore le associazioni sono costituite da differenti specie di marginotruncana globotruncanita stuarti, rosita contusa, abatomphalus mayeroensis che indicano la parte alta del cretaceo. è molto difficile, invece, riconoscere o ritrovare l’intervallo stratigrafico del paleocene, mentre sono presenti varie g. montana et al. specie dell’eocene dell’inferiore-superiore tra cui, morozovella aragonensis, morozovella formosa, truncarotaloides rorhi, acarinina bulbrooki, turborotalia cerroazulensis. l’oligocene inferiore è caratterizzato dalla presenza di pseudohastigerina micra e cassigerinella chipolensis che permettono di riconoscere l’omonima biozona (iaccarino, 1985). 4. risultati e discussione 4.1 caratteristiche granulometriche le materie prime ceramiche oggetto di studio sono state sottoposte ad analisi granulometrica, a fini classificativi, seguendo la procedura precedentemente descritta. i risultati analitici, una volta proiettati nel diagramma ternario di shepard (1954) consentono di mettere in evidenza alcune interessanti differenze che, a loro volta, possono essere poste in relazione con la maggiore o minore diffusione avuta da tali materiali nella manifattura ceramica tradizionale del territorio in esame (fig. 2). come si può osservare in figura 2, innanzitutto, anche nell’ambito delle singole formazioni argillose esiste una dispersione più o meno marcata dei contenuti relativi di sabbia, silt e argilla tra i differenti punti di prelievo. i campioni rappresentativi delle argille di ficarazzi accoppiano una certa variabilità nell’abbondanza della frazione sabbiosa, che è generalmente alta, ad oscillazioni non trascurabili nel rapporto tra le due componenti fini (silt e argilla). i campioni prelevati dalla formazione terravecchia non formano un gruppo particolarmente omogeneo anche se, in grande prevalenza, sono classificabili come silt argillosi. la variabilità nella distribuzione granulometrica di queste argille sembra essere condizionata soprattutto dalle abbondanze relative del silt e della sabbia. da notare, in ogni caso, che la dimensione dei granuli sabbiosi in queste argille ricade prevalentemente nell’ambito della sabbia molto fine (0.06÷0.125 mm); raramente si hanno granuli con dimensioni maggiori di 0.2 mm. le argille del flysch numidico risultano essere caratterizzate da contenuti in sabbia sufficientemente costanti, per lo più prossimi o inferiori al 10% (in peso) e da proporzioni maggiormente variabili di particelle afferenti alle classi dimensionali fini, distribuendosi nei campi dei silt argillosi e delle argille siltose. le argille varicolori, rispetto alle altre tipologie analizzate, possiedono certamente la maggiore omogeneità granulometrica, risultando collocate, di conseguenza, in un intorno abbastanza circoscritto del diagramma triangolare (campo delle argille siltose). in tutti i campioni rappresentativi di questa formazione, si registra una netta predominanza delle frazioni granulometriche più fini (il tenore medio in particelle inferiori a 2 µm risulta essere intorno al 55%, quindi leggermente prevalente sul silt) ed un contenuto di sabbia generalmente basso, più o meno inferiore al 10%. in definitiva, tra i materiali analizzati, sono le argille della formazione terravecchia quelle che, tra tutte, possiedono le caratteristiche granulometriche più vicine ad un materiale argilloso effettivamente idoneo ad essere utilizzato come materia prima per la manifattura ceramica. infatti, esse hanno un rapporto equilibrato tra le componenti più fini (argilla e silt) che, associato ad un moderato contenuto in scheletro sabbioso fine e molto fine (anche se non particolarmente costante), le rende ipoteticamente utilizzabili tal quali, senza dover ricorrere a trattamenti preliminari più o meno complessi (setacciatura, decantazione, dimagrimento). 4.2 composizione mineralogica l’analisi mineralogica dei campioni di argilla mediante diffrattometria a raggi x (xrd) ha consentito di evidenziare qualità altrettanto significative che contribuiscono a valutare la maggiore o minore idoneità dei singoli materiali ai fini della produzione ceramica. in tabella 1, per ognuna delle quattro formazioni oggetto di studio, è riportata una stima semiquantitativa mediata delle abbondanze relative delle fasi mineralogiche rilevate dall’analisi del tout-venant. il quarzo risulta essere sempre la fase mineralogica predominante, indipendentemente dalla distribuzione granulometrica del sedimento. per quanto riguarda la calcite, mentre nelle argille di ficarazzi e nella formazione terravecchia questo minerale è abbondante o comune con un’abbondanza relativa verosimilmente proporzionale al contenuto di microfauna fossile dei campioni, nel caso delle argille varicolori mostra un’ampia variazione. questo risultato è certamente da correlare alla tettonizzazione che caratterizza questi materiali (argille scagliose); per cui, localmente, in corrispondenza dei fitti reticolati di sottili fessure, possono essere presenti mineralizzazioni secondarie di calcite. il flysch numidico è l’unica argilla caratterizzata da tenori in calcite sempre molto bassi. le altre fasi mineralogiche rilevate in piccole quantità o in tracce sono dolomite, mica, k-feldspato, plagioclasio ed ematite. tracce o piccole quan285 fig. 2 classificazione delle materie prime argillose della sicilia nord-occidentale mediante il diagramma ternario di shepard. classification of clayey raw materials from north-western sicily according the shepard's ternary diagram. definizione composizionale delle “argille ceramiche” ... tità di dolomite e mica sono state riscontrate solo nelle argille di ficarazzi e nella formazione terravecchia; mentre gli ossidi di ferro cristallino, sotto forma di ematite, appaiono relativamente più abbondanti nei depositi del flysch numidico e delle argille varicolori, sebbene siano sempre in quantità appena rilevabili. e’ interessante sottolineare che i campioni della formazione terravecchia si distinguono in modo caratteristico da tutte le altre argille oggetto di studio per la presenza di quantità relativamente maggiori di mica e feldspato. anche per quanto concerne le abbondanze relative dei minerali argillosi che caratterizzano la frazione inferiore ai 2 µm delle materie prime considerate è possibile evidenziare alcune differenze significative, come mostrato nell’istogramma di figura 3. le argille di ficarazzi risultano essere mediamente caratterizzate da quantità pressoché equivalenti di illite, caolinite e smectite (con leggera prevalenza delle ultime due fasi), mentre non è stata rilevata la presenza di clorite in nessuno dei campioni analizzati. invece, i campioni rappresentativi della formazione terravecchia mostrano, nel complesso, una chiara prevalenza dell’illite (in media circa il 40% del totale dei minerali argillosi), con caolinite e smectite relativamente meno abbondanti. da segnalare la presenza di una quantità di clorite stimata intorno al 10%. le argille del flysch numidico, sono le uniche in cui si registra una leggera prevalenza della caolinite sull’illite. anche la componente smectitica appare ben rappresentata (intorno al 25% del totale dei minerali argillosi), mentre la clorite risulta presente in quantità trascurabili. infine, le argille varicolori possiedono una composizione mineralogica abbastanza caratteristica che vede prevalere nettamente illite e smectite, soprattutto sotto forma di strati misti. queste due fasi insieme rappresentano oltre l’80% del totale dei costituenti argillosi. la caolinite è presente in quantità molto inferiori rispetto alle altre argille esaminate ed anche la clorite è presente in quantità molto piccole. anche in questo caso i materiali argillosi della formazione terravecchia sono quelli che sembrano essere, almeno teoricamente, quelli relativamente più adatti alla produzione ceramica. infatti, si tratta di argille illitiche con un contenuto in fillosilicati a reticolo espandibile relativamente meno significativo (al contrario delle argille varicolori e delle argille di ficarazzi), caratterizzate al tempo stesso da un equilibrato contenuto naturale in fondenti (calcite e feldspati). 4.3 composizione chimica (xrf) i risultati ottenuti dall’analisi chimica, riferiti agli elementi maggiori (espressi in % in peso e normalizzati rispetto alla perdita a fuoco) ed in traccia (espressi in ppm), sono presentati in tabella 2. 286 tab. 1 stima semiquantitativa ottenuta mediante analisi xrd delle fasi mineralogiche presenti nella frazione più grossolana (> 0.002 mm) dei materiali argillosi oggetto di studio. legenda: xxxx = molto abbondante; xxx = abbondante; xx = comune; x = piccole quantità; tr = tracce; = non rilevato. relative abundances of the mineralogical phases in the coarser fraction (> 0.002 mm) of the studied clayey materials carried out by xray diffraction analysis. legend: xxxx = very abundant; xxx = abundant; xx = common; x = few quantities; tr = trace; = lower than detection limit. fase mineralogica argille di ficarazzi argille terravecchia flysch numidico argille varicolori quarzo xxxx xxxx xxxx xxx calcite xx/xxx x/xx tr tr/xx dolomite tr tr mica tr x k-feldspato tr tr/x tr/x tr plagioclasio tr/x tr/x ematite tr tr tr fig. 3 abbondanze relative (valori medi) dei fillosilicati presenti nella frazione più fine delle argille studiate (< 0.002 mm). relative abundances (average values) of phyllosilicates detected in the finest fraction of the studied clays (< 0.002 mm). g. montana et al. 287 tab. 2 concentrazione elementi maggiori (% in peso) minori e in tracce (ppm) dei materiali argillosi ottenute con l’analisi xrf e normalizzate verso la perdita per calcinazione (l.o.i). mayor (wt%) and trace (ppm) element concentrations of the raw materials, obtained through xrf analysis and normalised versus l.o.i. sample sio2 tio2 al2o3 p2o5 fe2o3 mgo mno cao na2o k2o rb sr y zr cr ni ba la ce v hm 3 05.8 0.01 01.9 000. 0.07 0.03 000 0.09 0.01 0.02 120 289 29 285 109 53 230 30 76 138 hi.1 05.8 0.01 01.8 000. 0.07 0.03 000 0.08 0.01 0.02 117 240 26 217 89 56 257 38 68 145 hi.2 05.9 0.01 01.9 000. 0.07 0.03 000 0.08 0.01 0.03 131 257 28 240 96 61 234 35 81 147 hi.3 05.8 0.01 01.9 000. 0.08 0.03 000 0.07 0.01 0.03 108 211 22 187 110 61 250 36 81 147 hi.4 05.7 0.01 01.9 000. 0.09 0.03 000 0.08 0.01 0.03 112 232 24 211 92 56 236 39 90 131 hi.5 05.9 0.01 01.9 000. 0.07 0.03 000 0.08 0.01 0.02 117 246 26 243 102 54 237 32 80 133 hi.6 05.7 0.01 01.9 000. 0.09 0.03 000. 0.07 0.01 0.03 107 199 22 185 102 52 243 41 77 144 hi.7 05.8 0.01 01.8 000. 0.08 0.03 000 0.08 0.01 0.02 112 243 27 249 87 56 233 36 74 136 hi.8 05.8 0.01 01.9 000. 0.08 0.03 000 0.08 0.01 0.03 113 236 24 199 104 60 248 36 80 141 hi.10 05.9 0.01 01.9 000. 0.07 0.03 000 0.08 0.01 0.03 130 265 29 224 94 61 242 34 83 141 hi.11 05.7 0.01 01.9 000. 0.08 0.03 000. 0.08 0.01 0.03 104 221 22 180 103 51 259 36 78 140 hi.12 05.8 0.01 01.9 000. 0.07 0.03 000 0.08 0.01 0.03 121 237 24 210 101 53 234 39 93 145 hi.13 05.8 0.01 01.9 000. 0.09 0.02 000. 0.06 0.01 0.02 108 209 24 230 97 62 234 32 90 148 hi.14 05.9 0.01 01.9 000. 0.07 0.03 000 0.07 0.01 0.03 111 209 21 155 99 47 237 36 95 139 hi.15 05.9 0.01 01.8 000. 0.08 0.03 000 0.08 0.01 0.02 90 203 19 144 112 66 241 32 86 149 hi.16 05.8 0.01 01.9 000. 0.07 0.03 000 0.08 0.01 0.03 108 217 21 164 106 55 259 42 72 144 hi.18 05.8 0.01 02.0 000. 0.08 0.03 000 0.07 0.01 0.03 96 192 17 155 95 54 242 37 79 162 hi.19 05.9 0.01 01.9 000. 0.07 0.03 000 0.08 0.01 0.03 125 260 27 253 106 53 244 33 77 139 hi.20 06.0 0.01 01.8 000. 0.07 0.03 000 0.08 0.01 0.03 95 197 18 147 90 53 254 34 80 136 hi.21 05.8 0.01 01.9 000. 0.08 0.03 000 0.08 0.01 0.03 107 222 22 181 100 52 223 37 87 148 hi.22 05.8 0.01 01.9 000. 0.08 0.03 000 0.08 0.01 0.03 100 235 21 176 94 55 234 33 101 144 hi.23 05.8 0.01 01.8 000. 0.07 0.03 000 01.0 0.01 0.02 101 264 22 203 97 54 241 35 72 135 hi.24 05.7 0.01 01.9 000. 0.09 0.03 000. 0.08 0.01 0.03 102 221 21 178 95 53 244 36 87 149 fct1 05.9 0.01 01.9 000. 0.07 0.03 000 0.07 0.01 0.03 100 198 18 173 122 49 266 34 70 165 fct2 06.1 0.01 01.7 000. 0.07 0.03 000 0.07 0.01 0.03 119 235 24 200 146 61 316 42 75 173 fct3 06.2 0.01 01.6 000. 0.06 0.03 000 0.08 0.01 0.02 105 131 12 89 95 37 270 38 77 122 fct4 06.0 0.01 01.7 000. 0.06 0.03 000 0.08 0.01 0.02 112 195 18 181 104 45 286 40 80 134 media 05.9 0.01 01.9 000. 0.07 0.03 000 0.08 0.01 0.03 110 225 23 195 102 54 248 36 81 144 sample sio2 tio2 al2o3 p2o5 fe2o3 mgo mno cao na2o k2o rb sr y zr cr ni ba la ce v camp. 1 52,78 1,29 20,35 0,07 8,53 1,84 0,03 0,57 0,09 1,93 n.m. n.m. n.m. n.m. n.m. n.m. n.m. n.m. n.m.n.m. camp. 2 05.8 0.01 02.5 000. 01.0 0.02 000 0.01 000. 0.02 135 231 44 201 124 n.m. 367 72 146 286 camp. 3 06.0 0.01 02.3 000. 0.09 0.02 000. 0.01 000. 0.02 99 126 22 134 101 n.m. 389 48 98 206 camp. a 64,52 1,12 21,72 0,12 7,39 1,71 0,04 1 0,27 2,1 139 184 29 191 73 n.m. 334 98 198 211 camp. c 61,66 1,1 21,55 0,12 8,27 2,5 0,21 1,68 0,2 2,71 202 235 38 200 165 n.m. 519 56 124 334 camp. d 63,94 1,07 21,83 0,12 8,05 1,75 0,03 0,85 0,32 2,05 161 364 38 185 146 n.m. 531 50 108 309 camp. e 60,06 1,25 24,38 0,09 8,16 2,5 0,11 0,57 0,4 2,5 154 807 33 110 113 n.m. 438 33 65 232 camp. f 63,25 1,25 23,01 0,06 6,47 2,32 0,03 0,27 0,42 2,91 201 163 26 188 84 n.m. 495 99 232 240 media 06.1 0.01 02.3 000. 0.08 0.02 000 0.01 000. 0.02 156 301 33 173 115 n.m. 439 65 139 260 sample sio2 tio2 al2o3 p2o5 fe2o3 mgo mno cao na2o k2o rb sr y zr cr ni ba la ce v f1 06.0 0.01 01.8 000. 0.08 0.03 000 01.0 000. 0.01 50 261 21 282 74 27 186 28 70 100 s1 05.9 0.01 01.8 000. 0.07 0.02 000 0.09 0.02 0.02 97 272 23 250 92 30 167 33 83 119 ac1 05.9 0.01 01.8 000. 0.07 0.03 000 01.0 000. 0.02 84 335 20 218 67 26 204 29 73 115 ac2 05.8 0.01 01.5 000. 0.06 0.03 000 01.4 0.01 0.02 68 351 25 181 59 24 187 21 60 100 media 05.9 0.01 01.7 000. 0.07 0.03 000 01.1 0.01 0.02 07.5 305 22 232 73 27 186 28 71 109 sample sio2 tio2 al2o3 p2o5 fe2o3 mgo mno cao na2o k2o rb sr y zr cr ni ba la ce v hm 4 06.1 0.01 02.2 000 0.08 0.02 000. 0.01 0.02 0.03 181 227 30 188 108 65 271 39 80 134 camp. 7 63,49 0,8 18,13 0,1 8,48 2,94 0,12 1,57 1,23 3,33 268 451 36 111 96 n.m. 305 40 79 245 av1 05.8 0.01 02.4 000. 0.08 0.03 000 0.03 0.01 0.02 80 354 20 225 167 51 138 48 90 165 av2 06.0 0.01 02.1 000. 0.07 0.03 000 0.04 0.01 0.02 81 123 14 108 234 44 117 41 83 308 av3 05.8 0.01 02.7 000. 0.08 0.02 000. 0.01 0.01 0.02 88 131 18 132 233 61 168 44 87 276 av4 05.8 0.01 01.8 000. 0.08 0.03 000. 0.09 0.02 0.02 84 295 25 119 116 69 147 44 88 161 av5 06.1 0.01 01.9 000. 0.08 0.03 000. 0.05 0.02 0.02 75 226 12 107 112 69 124 41 81 151 media 06.0 0.01 02.1 000. 0.08 0.03 000. 0.03 0.01 0.02 122 258 22 141 152 60 181 42 84 206 fo r m a z io n e t e r r a v e c c h ia fl y s c h n u m id ic o a r g il le d i f ic a r a zz i a r g il le v a r ic o lo r i definizione composizionale delle “argille ceramiche” ... già un primo esame sommario consente di apprezzare alcune differenze sostanziali nel chimismo dei vari campioni argillosi che possono essere considerate in buon accordo con quanto già osservato mediante le analisi mineralogiche e, in misura minore, anche con le specifiche caratteristiche di distribuzione granulometrica. tra gli ossidi degli elementi maggiori soltanto i tenori in sio2 e p2o5, non sembrano in alcun modo possedere i requisiti per essere considerati come “markers” di una delle formazioni argillose studiate, data la sostanziale corrispondenza dei valori medi e dei campi di variazione. al contrario, i valori medi delle concentrazioni in cao, al2o3, fe2o3, k2o, na2o, tio2, mgo ed mno, specie se utilizzati in modo incrociato, sembrano poter fornire criteri sufficientemente efficaci per differenziare tra loro le materie prime. tuttavia, occorre sottolineare che la maggior parte di queste variabili non può essere considerata, allo stato attuale degli studi, come “marker” peculiare di una singola tipologia di argilla. i depositi del flysch numidico e delle argil le varicolori si distinguono dagli altri per le concentrazioni mediamente più alte in al2o3 (superiori al 21% in peso), fe2o3 (intorno all’8% in peso) ed mno (pari o superiori al lo 0.1 % in peso), come pure per i tenori medi estremamente più bassi in cao (rispettivamente 0,89 e 3.35% in peso). inoltre, in particolare, le argil le del flysch numidico sono caratterizzate anche da un tenore molto basso in na2o, in media corrispondente allo 0.31% in peso e con un campo di variazione molto ristretto (dallo 0.09% allo 0,49% in peso), oltre che da valori in tio2 mediamente più alti e sempre superiori all’1% in peso. le argille di ficarazzi, tra tutte quelle prese in considerazione in questo studio, risultano differenziate dalla maggiore concentrazione media in cao (superiore al 10% in peso) e da valori relativamente più bassi di al2o3, fe2o3 e k2o. anche i l tenore in na2o appare sostanzialmente modesto rispetto agli altri materiali (ad esclusione del flysch numidico), nonostante il valore medio risenta molto di un campione (s1) prelevato in affioramento a pochi metri dalla battigia (presso la spiaggia dell’olivella a poche centinaia di metri dall’insediamento fenicio-punico di solunto) e quindi evidentemente contaminato da sale marino. i materiali prelevati dagli affioramenti della formazione terravecchia sono caratterizzati da tenori in cao intermedi (inferiori all’8% in peso) e da una concentrazione di k2o relativamente più elevata, specialmente rispetto alle argille di ficarazzi. questa caratteristica può essere correlata alla presenza di mica e feldspato come effettivamente rilevato nel corso delle analisi xrd. in figura 4 sono tra loro confrontati i campi di variazione composizionale ed i valori medi di alcuni degli ossidi degli elementi maggiori più significativi ai fini della differenziazione delle materie prime ceramiche (cao, al2o3, fe2o3 e k2o). innanzitutto, ad esclusione del cao, deve essere sottolineata una notevole sovrapposizione dei campi di variazione degli elementi considerati, contrapposta a 288 fig. 4 diagrammi comparativi degli intervalli di variazione delle concentrazioni (espresse in % in peso) e dei relativi valori medi per alcuni tra gli elementi maggiori considerati più significativi nelle argille studiate. comparative plots of the variation of concentration values and corresponding averages of the most significative major elements oxides (wt %) in the studied clays. g. montana et al. differenze più o meno significative dei valori medi. per ciò che riguarda il cao, le argille varicolori possiedono il campo di variazione più esteso e sono, altresì, caratterizzate da una disposizione asimmetrica del valore medio (verso i valori più bassi dell’ intervallo). quest’ultimo aspetto può essere compreso considerando che 6 campioni su un totale di 7 hanno un tenore in cao ben al di sotto del 5% ed un solo campione, che ne possiede l’8.68% in peso, crea la variabilità rilevata. anche il valore mediano (3.22%) risulta prossimo alla media aritmetica (3.35%). una certa variabilità del contenuto in cao con disposizione marcatamente asimmetrica del valore medio si registra anche per le argille di ficarazzi. tuttavia, questo risultato deve essere considerato con prudenza dato che il numero dei campioni analizzati è, come precedentemente spiegato, forzatamente piccolo. le argille del flysch numidico possiedono una variabilità estremamente ristretta del contenuto in cao ed il valore medio si dispone in modo simmetrico nell’intervallo dei valori. anche le argille della formazione terravecchia sono caratterizzate da un campo di variazione in cao ristretto e da un valore medio rappresentativo. l’esame dei campi di variazione relativi agli altri elementi suggerisce una variabilità contenuta della concentrazione di al2o3 e relativamente più ampia per i tenori di fe2o3 e k2o nel caso dei materiali argillosi del flysch numidico. le argille di ficarazzi ed i materiali della formazione terravecchia mostrano intervalli di variazione molto ristretti ed abbastanza piccoli anche in k2o, mentre sono caratterizzati da una maggiore variabilità del contenuto in fe2o3. le argil le varicolori, infine, sono differenziate dagli altri materiali per un campo di variazione particolarmente limitato in fe2o3 e, al contrario, possiedono un intervallo di relativamente più ampio per quanto riguarda i contenuti di k2o e al2o3, con disposizione marcatamente asimmetrica dei valori medi. in definitiva, soprattutto attraverso il rapporto cao/al2o3 le argille del flysch numidico e, in genere, anche le argil le varicolori possono essere chiaramente differenziate dai campioni rappresentativi della formazione terravecchia (che a loro volta formano un gruppo assai omogeneo) e dalle argille di ficarazzi. queste ultime, invece, risultano mediamente più povere in allumina e più ricche in cao rispetto ai materiali miocenici (fig. 5a). in ogni caso, entrambe possono essere classificate come “argille calcaree” (cao > 5% secondo maniatis & tite, 1978), al contrario dei materiali del flysch numidico e delle argille varicolori che sono da considerare “argille non calcaree” (cao < 5%). l’esame dei risultati relativi agli elementi in traccia lascia intravedere, in primo luogo, una ragionevole connessione con gli elementi maggiori geochimicamente affini, ovvia conseguenza delle caratteristiche mineralogiche dei materiali esaminati. attraverso semplici diagrammi binari può essere verificata, ad esempio, la buona correlazione del k2o sia con il rb che con il ba, verosimilmente collegabile con il contenuto in mica e feldspato (fig. 5b, 5c). al tempo stesso, è possibile ottenere una soddisfacente discriminazione tra le argille oggetto di studio, con concentrazioni molto simili (con rare eccezioni) per tutti i campioni della formazione terravecchia, relativamente più basse per le argille di ficarazzi e gran parte delle argille varicolori, decisamente più alte nel caso dei materiali argillosi del flysch numidico. anche il confronto dei tenori in terre rare consente di confermare una volta ancora la notevole omogeneità composizionale delle argil le della formazione terravecchia e, al contrario, la grande variabilità dei materiali del flysch numidico, che, anche 289 fig. 5 diagrammi binari: (a) cao-al2o3; (b) bak2o; (c) rbk2o (d) ce-la; (e) ni-cr. binary diagrams: (a) cao-al2o3; (b) bak2o; (c) rbk2o (d) ce-la; (e) ni-cr. definizione composizionale delle “argille ceramiche” ... in questo caso, sono caratterizzati da valori tendenzialmente più elevati rispetto alle altre argille (fig. 5d). infine, il diagramma binario tra cr e ni (fig. 5e) dimostra che attraverso questi elementi è possibile discriminare in modo accettabile le argille di ficarazzi dalle argille della formazione terravecchia, con queste ultime caratterizzate da tenori medi in entrambi gli elementi superiori di circa il 50%. 4.4 simulazione del ciclo produttivo come già anticipato in precedenza, soltanto le argille di ficarazzi (pleistocene) e le argille della formazione terravecchia (miocene) sono state sottoposte ad una simulazione di ciclo produttivo e ad analisi di tipo tecnologico. questa decisione è scaturita da evidenze etnografiche, archeologiche ed archeometriche che inducono a considerarle, con un buon margine di sicurezza, le materie prime più utilizzate per la produzione ceramica nel territorio oggetto di studio (alaimo et al., 2002; 2003; montana et al.., 2003). com’è noto, le caratteristiche macroscopicamente più evidenti di un impasto ceramico, quali la sua lavorabilità allo stato plastico, il comportamento in seguito ad essiccamento e cottura ed il colore del prodotto finito rappresentano le proprietà specifiche tenute empiricamente sotto controllo dagli antichi artigiani. queste caratteristiche erano giustamente considerate le più efficaci per selezionare le materie prime disponibili nello specifico contesto territoriale, allo scopo di mettere a punto una catena operativa completa e tecnologicamente avanzata, per la realizzazione di manufatti ceramici che garantissero, al tempo stesso, una soddisfacente funzionalità, un alto livello qualitativo e/o costi di produzione contenuti. la quantificazione dei sopraccitati parametri nelle argille di ficarazzi e nelle argille della formazione terravecchia è stata fatta, pertanto, per ottenere indicazioni utili ad una migliore comprensione delle scelte tecnologiche fatte dagli artigiani sicelioti, anche più di duemila anni addietro. inoltre, la simulazione del processo produttivo (manifattura di impasti sperimentali e cottura a temperature ben definite) è stata intrapresa anche per perseguire l’obiettivo, non meno importante, di provvedere ad una descrizione petrografica degli impasti ottenibili con le argille campionate. i dati petrografici possono successivamente essere utilizzati per effettuare attendibili confronti con reperti archeologici e/o i manufatti ceramici di età storica sospettati di essere stati prodotti con le stesse materie prime. 4.4.1 plasticità, colore e ritiro lineare la plasticità è un particolare comportamento reologico che i materiali argillosi manifestano con l’aggiunta un’appropriata quantità di acqua. essa consiste nella capacità del materiale stesso di assumere una deformazione permanente senza perdita di coesione e conseguente formazione di fessure. questa proprietà è controllata da diversi fattori, tra cui, soprattutto, l’abbondanza relativa dei minerali argillosi a reticolo espandibile nella frazione minore di 2 µm, la ripartizione delle varie frazioni granulometriche, nonché la presenza di materia organica. una procedura semplice ed allo stesso tempo attendibile comunemente usata per la determinazione della plasticità dei materiali argillosi di potenziale utilizzo ceramico è quella basata sulla misura degli indici di atterberg (marsigli & dondi, 1997). i limiti di consistenza dei materiali incoerenti come le terre argillose, molto schematicamente, vengono definiti dal contenuto di acqua che convenzionalmente caratterizza il passaggio dallo stato di fluido viscoso a quello plastico (limite di liquidità wl) e dallo stato plastico a quello semisolido (limite di plasticità wp). il contenuto di acqua per cui il materiale permane allo stato plastico è definito dall’indice di plasticità ip, ottenuto dalla differenza tra il limite liquido e quello plastico. i risultati relativi alle determinazioni empiriche dei limiti di atterberg ed al calcolo dell’indice di plasticità sono riportati in tabella 3. 290 tab. 3 limiti di atterberg relativamente ai campioni delle argille di ficarazzi e della formazione terravecchia. atterberg’s consistency limits of samples belonging to ficarazzi and terravecchia clayey’s formations. campione wl % wp % ip % argille di ficarazzi f1 49 21 28 s1 70 27 43 ac1 39 18 21 ac2 38 20 18 argille terravecchia hi1 44 21 23 hi2 47 25 22 hi3 49 27 22 hi4 46 24 22 hi5 45 22 23 hi6 45 21 24 hi7 42 24 19 hi8 52 18 34 hi10 45 22 23 hi14 46 21 25 hi16 47 22 25 hi18 51 20 31 hi19 45 18 27 hi20 42 21 21 hi21 48 18 29 hi22 48 19 30 hi23 41 19 22 fct1 53 26 27 fct2 55 35 21 fct3 42 21 21 fct4 40 24 16 entrambe le tipologie di materiale, nella grande maggioranza dei casi, risultano caratterizzate da valori accettabili di limite di liquidità e di indice di plasticità, tali da poter essere definite come argille di “media plasticità”. in particolare, i valori riferiti alle argille della formazione terravecchia dimostrano anche una buona omogeneità, con un indice di plasticità medio ip = 24%, sempre abbondantemente inferiore alla soglia del 40% che contraddistingue i materiali molto plastici e, pertanto, non idonei (tal quali) all’impiego come materia prima ceramica. questo comportamento è una diretta conseg. montana et al. guenza della loro ottimale distribuzione granulometrica, ed anche della netta predominanza di minerali argillosi a reticolo non espandibile (illite e caolinite), rispetto alla smectite, nella frazione inferiore ai 2 µm. anche i campioni rappresentativi delle argille di ficarazzi possiedono un valore medio dell’indice di plasticità accettabile, sebbene leggermente più elevato (ip = 27%) rispetto ai materiali della formazione terravecchia. questo risultato, tuttavia, è condizionato dal campione s1 che, come già accennato, è parzialmente contaminato da sale marino, la cui presenza influisce notevolmente sul limite liquido wl (e quindi sull’indice di plasticità). inoltre, occorre considerare anche la maggiore abbondanza di smectite di queste argille pleistoceniche (in media il 38% del totale dei minerali argillosi) decisamente più alta rispetto ai materiali miocenici della formazione terravecchia (in media pari al 24% del totale dei minerali argillosi). ad ogni modo, i campioni di entrambe le tipologie di materiale oggetto di studio, se proiettati nel diagramma di marsigli & dondi (1997) che mette in relazione limite liquido ed indice plastico, fornendo uno schema di previsione del comportamento in foggiatura delle argille per terracotta e laterizi, ricadono in grande prevalenza nei campi delle “argille impasto” e delle “argille base” (fig. 6). quindi, sono da considerare materiali che, in linea di massima, possiedono naturalmente una plasticità ottimale per la lavorazione o, secondo la destinazione d’uso dell’oggetto, necessitano di piccole correzioni attraverso l’aggiunta di opportune quantità di degrassante sabbioso, oppure la miscela con altre argille più magre. anche il ritiro lineare in seguito ad essiccamento e cottura è un parametro utile nella caratterizzazione di una materia prima argillosa, poiché consente di valutare empiricamente l’idoneità del materiale stesso ad essere utilizzato, tal quale, per la produzione di ceramica. in linea di massima, ad un limitato ritiro lineare, sia in fase di essiccamento che di cottura, corrisponde una maggiore idoneità teorica dell’argilla a fungere da materia prima ceramica, in quanto vi è un minor rischio che si formino fessure in seguito a ritiro differenziale. il ritiro lineare nell’intervallo 25÷100°c è legato alla perdita dell’acqua di impasto e dell’umidità intrappolata. il ritiro tra 100°c e 950°c è, invece, dovuto alla espulsione dell’acqua strutturale (a partire da circa 600°c), al processo di decarbonatazione (750÷900°c), alla produzione di fasi di neoformazione (a partire da 850÷900°c). le medie dei valori rilevati nei campioni della formazione terravecchia e nelle argille di ficarazzi sono graficamente rappresentate nell’istogramma di figura 7. il ritiro lineare si attesta al di sotto del 10% e con incrementi prossimi o inferiori all’1% e quindi, in linea di massima, è da ritenersi accettabile per entrambe le l itologie. tuttavia, i material i della formazione terravecchia mostrano un comportamento relativamente migliore rispetto alle argille di ficarazzi soprattutto in fase di essiccamento ed a basse temperature di cottura (ritiri minori di circa l’1÷1.5%), mentre la differenza sembra attenuarsi leggermente alle alte temperature. tali risultati possono essere interpretati considerando quanto emerso dalle analisi granulometriche e mineralogiche (xrd) che hanno messo in luce una più equilibrata distribuzione granulometrica per le argil le della terravecchia rispetto alle argil le di ficarazzi, che, inoltre, sono caratterizzate dalla presenza di una maggiore quantità di minerali argillosi a reticolo espandibile nella frazione inferiore a 2 µm. un fattore che può contribuire a ridurre il ritiro lineare alle temperature più alte è il contenuto in caco3, che, come visto, dalle analisi mineralogiche e chimiche, è in media relativamente più abbondante nelle argille pleistoceniche. infatti, durante il processo di cottura, successivamente alla decarbonatazione 291 fig. 6 schema di previsione del comportamento in foggiatura delle argille in accordo a quanto proposto da marsigli & dondi (1997). diagram for estimating moulding behaviour of clays after marsigli & dondi (1997). fig. 7 confronto tra i valori medi di ritiro lineare (%) mostrati dalle argille di ficarazzi e dalle argille della formazione terravecchia in seguito a cottura a diverse temperature. comparison between the average values of linear shrinkage (%) showed by the ficarazzi and terravecchia clayey’s formations after firing treatments at various temperatures. definizione composizionale delle “argille ceramiche” ... abbiamo reazioni che conducono alla formazione di nuove fasi cristalline (come gehlenite e pirosseno calcico) che contrastano, in linea di massima, la contrazione del prodotto ceramico. la variazione cromatica dei provini sottoposti a cottura sperimentale è mostrata in tabella 4, valutata mediante i codici alfanumerici di munsell (munsell soil colour charts). come noto, lo sviluppo del colore nella ceramica è legato a processi chimico-fisici che, fondamentalmente, dipendono dalla composizione chimica del materiale di partenza, dalle temperature massime raggiunte e dalla abbondanza di ossigeno nella camera di cottura (atmosfera ossidante o riducente). il colore di un manufatto ceramico è condizionato in modo prevalente dalla presenza di fe++ e fe+++, presenti negli ossidi, ovvero accolti nel reticolo cristallino delle fasi silicatiche che si sviluppano in cottura (gehlenite e pirosseno). secondo recenti studi gli elementi chimici ai quali è possibile attribuire un’influenza più o meno importante sul colore dei prodotti ceramici sono ferro, calcio, alluminio, titanio, e magnesio (fabbri & dondi, 1995); tra questi, risulta in tal senso determinante la concentrazione di cao e, ancora di più, il rapporto fe2o3 /cao. già alla temperatura di 300 °c i campioni delle due argille mostrano un primo cambiamento di colore che aggiunge, alla precedente tinta (hue) del giallo (5y) o del grigio (gley), una prima componente del rosso (5yr; 7,5yr). questo cambiamento può essere attribuito all’avanzare del processo di disidratazione dei minerali argillosi e degli ossidi di ferro presenti nel materiale. assai più consistenti, invece, sono le modifiche di tinta alle elevate temperature. infatti, a 950 °c è pressoché del tutto completo il processo di formazione delle nuove fasi mineralogiche, come la gehlenite, il diopside e/o la wollastonite; mentre l’ematite va assumendo una cristallinità sempre maggiore. le quantità relative di questi nuovi composti, oltre a conferire una nuova struttura al prodotto finito, contribuiscono a determinare il colore finale. alla temperatura di 950 °c, in un atmosfera di cottura e di raffreddamento pienamente ossidante (come si osserva in tabella 4), nelle tipologie di argilla oggetto di studio domina la tinta del rosso (2.5yr), essendo entrambi i materiali caratterizzati da un rapporto fe2o3/cao compreso tra 0.7 e 1. 4.4.2 descrizione petrografica ed esempi di determinazione di provenienza per alcune classi di reperti archeologici la caratterizzazione petrografica dei provini realizzati con le argille di ficarazzi e le argille della formazione terravecchia è stata effettuata valutando distribuzione, addensamento, granulometria e composizione mineralogica del degrassante. per la stima visiva sono state utilizzate delle tavole comparative (terry & chalingar,1955; bullock et al.,1985; tucker,1981) l’impasto delle argil le della formazione terravecchia è caratterizzato un degrassante con, in genere, una grande prevalenza della sabbia molto fine (0.06÷0.125mm) rispetto alla sabbia fine (0,125÷0,25 mm). rari i granuli con dimensioni maggiori di 0.25 mm. l’addensamento risulta piuttosto variabile, prevalentemente compreso tra 5 e 15%; molto raramente raggiunge valori più alti intorno al 25%. il costituente principale è il quarzo monocristallino, rappresentato da frammenti subangolosi o sporadicamente subarrotondati (fig. 8a-b). la calcite, rappresentata da microfossili e, in misura minore, anche da frammenti litici è un costituente da comune a sporadico, sempre subordinato rispetto al quarzo monocristallino. minute lamelle di mica e piccoli frammenti di feldspato sono presenti in tutti i campioni analizzati e, sebbene in piccole quantità, possono essere considerati elementi caratteristici dell’impasto. componenti da assai subordinati a rari sono minerali opachi, clorite, glauconite, dolomite e litici cristallini acidi. tra i minerali accessori sono stati sporadicamente individuati apatite, zircone, rutilo e tormalina. nei provini cotti ad alta temperatura (950°c) i componenti di natura calcarea non sono più visibili, se non indirettamente, attraverso pori da impronta con orlo di schiarimento e/o micritic clots, vale a dire grumi di calcite microcristallina derivanti dalla ricarbonatazione dell’ossido di calcio nella fase di raffreddamento (cau et 292 litologia campioni 100°c 300°c 950° c fe2o3/cao f1 2.5y 5.5/1 10yr 5.5/3 5yr 6/5 0.8 argille di ficarazzi s1 2.5y 6.5/4 5yr 5/5 2.5yr 7/5 1.0 ac1 2.5y 6.5/4 5yr 5.5/5 2.5yr 6.5/8 0.7 ac2 2.5y 6.5/6 5yr 5.5/7 2.5yr7/6 0.5 hm 3 5y 5.5/1 10yr 5.5/3 7.5yr 6.5/4 0.8 hi 3 5y 6.5/1.5 7.5yr 5.5/3 5yr 5.5/7 1.1 hi 6 7.5y 7/1 10yr 5.5/2 2.5yr 5.5/6 1.3 hi 9 5y 6.5/1.5 10yr 6/4 2.5yr 6/6 0.7 hi 11 5y 6/1.5 7.5yr 5/3 5yr 6.5/5 0.9 argille terravecchia hi 12 5y 5.5/1 10yr 6/2.5 5yr 6.5/6 0.9 hi 19 2.5y 6/1.5 7.5yr 5.5/4 2.5yr 6/7 1.0 fct1 gley1 6/10y 10yr 5.5/2 2.5yr 5.5/8 1.0 fct2 gley1 6/5 gy 2.5y 5/2 2.5yr 5.5/6 1.0 fct3 gley1 6/10y 10yr 5/3 2.5yr 5.5/7 0.7 fct4 gley1 6.5/10y 10yr 5.5/2 2.5yr 5/7 0.8 tab. 4 colori secondo i codici munsell mostrati dai campioni delle argille di ficarazzi e della formazione terravecchia dopo cottura in atmosfera ossidante alle temperature di 100, 300 and 950°c. munsell colours showed by ficarazzi and terravecchia clayey’s samples after oxidizing fir ings at 100, 300 and 950°c. g. montana et al. al., 2002). l’impasto delle argille di ficarazzi risulta caratterizzato da un degrassante sabbioso con distribuzione granulometrica seriale. anche in questo caso prevale la sabbia molto fine (0,06÷0,125 mm) ma, a differenza delle argille precedentemente descritte, si hanno anche quantità relativamente minori, ma non trascurabili, di sabbia fine o media, e, più raramente, anche granuli con dimensione grossolana o molto grossolana (0.5÷2 mm). l’addensamento della frazione sabbiosa appare assai variabile, in genere compreso dal 10 al 25% ma può raggiunge valori anche molto più alti, sino ad oltre il 20%. il costituente predominante è il quarzo monocristallino contraddistinto da frammenti angolosi o subangolosi, seguito da quantità variabili da abbondanti a comuni di litoclasti e bioclasti calcarei. costituenti sempre presenti e caratterizzanti, benché in piccole quantità, risultano essere dei frammenti subarrotondati di quarzarenite, granuli selce, quarzo policristallino e kfeldspato (fig. 8c-d). tra i minerali accessori si segnala apatite (rara). anche in questo caso, come ovvio aspettarsi, dopo la cottura a 950°c la componente calcarea non è più visibile in nessuno dei campioni esaminati se non per mezzo di pori da impronta e/o micritic clots. come già sottolineato, uno dei risultati più importanti che ci si aspetta dalle analisi archeometriche sulle materie prime è dato dalla attestazione degli elementi distintivi dell’impasto realizzato in un dato centro di produzione, ed il controllo di eventuali variazioni nel tempo legate a differenti procedure tecnologiche, ovvero alla tipologia e alla destinazione d’uso dell’oggetto ceramico. questi aspetti, di grande ricaduta archeologica, hanno lo scopo di caratterizzare le manifatture locali e distinguerle dalle importazioni in specifici contesti di scavo, ben delimitati geograficamente e cronologicamente. per ogni categoria ceramica ritenuta di interesse, un confronto su base composizionale con le potenziali materie prime costituirebbe un criterio altamente oggettivo al fine di attestarne la produzione locale. inoltre, qualora si pensi che la stessa classe ceramica possa avere avuto una confacente diffusione in ambito regionale, o persino extraregionale, da questo tipo di studi potrebbe aversi anche un notevole apporto nella ricostruzione dei circuiti commerciali che, troppo spesso, ancora oggi, risulta quasi esclusivamente basata sul confronto morfologico e stilistico dei reperti. a scopo esemplificativo ed anche per verificare la reale significatività dei dati acquisiti sulle argille della sicilia nord-occidentale, è stato ritenuto utile effettuare un confronto tra le nostre materie prime con alcune classi di reperti ceramici già caratterizzati composizionalmente in studi precedenti. in particolare, sono state prese in considerazione classi di materiali di produzione accertata, o verosimilmente ipotizzata, nello stesso territorio (sicilia nord-occidentale) in epoche anche molto differenti: mattonelle da pavimentazione di produzione palermitana, datate dal xvi al xix secolo (alaimo et al., 2004); piatti e coppe decorate con vernice nera, di età ellenistica, provenienti da scavi effettuati a palermo, termini imerese, marineo e monte iato, ritenute imitazioni locali della produzione nota come campana a (belvedere et al., in stampa)2; coppe di età arcaica, note come iato k480, ritenute produzioni indigene derivate da analoghe forme attiche, ritrovate ad himera ed altri siti minori circostanti (vassallo, 1996; alaimo et al., 2000). dal confronto dei dati petrografici (osservazioni al microscopio polarizzatore delle sezioni sottili) inerenti le sopraccitate classi di reperti ceramici e i prodotti finiti ottenuti dagli impasti sperimentali delle argille selezionate risulta che i gruppi di reperti corrispondenti alle imitazioni di ceramica a vernice nera in forma di campana a ed alle mattonelle maiolicate del xvii secolo presentano caratteristiche composizionali e tessiturali del tutto compatibili con le argille di ficarazzi. esistono, infatti, forti somiglianze in termini 293 fig. 8 immagini al microscopio polarizzatore (nicol incrociati; barra dimensionale = 0.5 mm): argille della formazione terravecchia cotte a 300 °c (a) ed a 950 °c (b); argille di ficarazzi cotte a 300 °c (c) ed a 950 °c (d). images at the polarizing microscope (crossed nicol; scale bar = 0,5 mm): terravecchia formation clay after firing treatments at 300 °c (a) and 950 °c (b); ficarazzi clay after firing treatments at 300 °c (c) and 950 °c (d). definizione composizionale delle “argille ceramiche” ... 2per campana a si intende una ceramica da mensa assai pregiata, decorata a vernice nera, il cui centro di produzione è stato individuato nell’area della baia di napoli, ampiamente esportata nel mediterraneo occidentale a partire dal iii secolo a.c., che è stata imitata (riprodotta) anche in diversi centri di consumo. di degrassante sabbioso sia per distribuzione dimensionale (prevalenza di sabbia molto fine e fine) che per addensamento (10÷20%) e composizione, con predominanza dei granuli subangolosi di quarzo monocristallino sui microfossili a guscio calcareo (o dei pori da impronta e dei grumi micritici da essi derivati) e piccole quantità di granuli di selce, quarzarenite e feldspato. d’altra parte, è possibile osservare una notevole somiglianza, sempre in termini sia tessiturali che composizionali, tra l’impasto delle coppe iato k480 e le argille della formazione terravecchia. infatti, dal confronto incrociato emergono un addensamento medio intorno al 15% del degrassante sabbioso con dimensione in grande maggioranza molto fine. la componente silicoclastica risulta prevalere decisamente su quella carbonatica. in quantità relativamente subordinata ma in maniera caratterizzante sono presenti piccole quantità di mica, k-feldspato e plagioclasio. ulteriori ed ancor più convincenti conferme possono essere ricavate dal confronto chimico degli stessi gruppi di campioni ceramici con le materie prime oggetto di studio disponibili in loco. già ricorrendo a semplici diagrammi binari che mettono a confronto i rapporti di concentrazione degli ossidi di alcuni elementi maggiori particolarmente caratterizzanti, cao, al2o3, k2o, na2o (fig. 9) si può chiaramente constatare la buona corrispondenza tra le argille mioceniche della formazione terravecchia e le coppe iato k480; invece, sia le imitazioni locali di campana a che le mattonelle maiolicate mostrano una discreta affinità con le argille pleistoceniche (argille di ficarazzi). la dispersione che si nota in quest’ultimo caso potrebbe essere interpretata ipotizzando il ricorso, da parte dei ceramisti, a trattamenti preliminari della materia prima (dimagrimento nel caso di sfruttamento dei banchi di argilla più plastici). inoltre, nel caso delle mattonelle per pavimentazione, l’utilizzo di un impasto più sabbioso potrebbe essere stato dettato da una scelta tecnica consapevole del ceramista. comunque, è noto, ed è stato confermato in questo studio, che le argille di ficarazzi sono di per se caratterizzate da oscillazioni composizionali non trascurabili, legate principalmente al rapporto di abbondanza tra sabbia fossilifera e componente silico-clastica (cipolla, 1931). un’ulteriore e definitiva conferma dell’utilizzo di materie prime diverse tra quelle presenti nel territorio, nel caso delle classi ceramiche sopra discusse, può essere ottenuta ricorrendo ad un ben noto metodo di analisi statistica multivariata (analisi discriminante lineare lda), i cui risultati sono mostrati in figura 10. infatti, nello spazio bidimensionale rappresentato dalle prime due funzioni discriminanti (d1 e d2) le argille del flysch numidico costituiscono un gruppo abbastanza omogeneo e, comunque, ben distinto e separato dai reperti ceramici e dalle altre argille. al contrario, le argille varicolori, pur non avendo niente in comune con 294 fig. 9 confronto chimico tra le argille di ficarazzi e le argille della formazione terravecchia con alcune tipologie ceramiche prodotte (in varie epoche) nell’area oggetto di studio. chemical relationships between the ficarazzi and terravecchia clayey’s formations and some classes of ceramic artefacts which were produced (in various periods) in the same area. g. montana et al. i reperti ceramici usati per il confronto, possiedono una varianza interna (within-group variance) tale da non poter essere considerate come gruppo. infine, è molto importante sottolineare che le argille della formazione terravecchia ricadono nello stesso intorno composizionale delle coppe iato e le argille di ficarazzi (fig. 10) si associano, sebbene con un livello di dispersione maggiore, sia alle mattonelle da pavimentazione che alle imitazioni locali di forme in campana a. 5. considerazioni conclusive i risultati sopra esposti e discussi apportano un contributo alla conoscenza delle materie prime argillose che, nei secoli passati, sono state sfruttate per la produzione di manufatti ceramici nella sicilia nord-occidentale. la ricerca parte dalla puntuale collocazione dei depositi oggetto di interesse nel quadro geologico e stratigrafico del territorio sopraccitato, aspetto sul quale è stato riposto un adeguato impegno. dai dati ricavati dalle analisi dei campioni prelevati dalle formazioni argillose oggetto di studio è possibile concludere che in base alle caratteristiche di distribuzione granulometrica, di composizione mineralogica e chimica oltre che per le proprietà di plasticità, ritiro lineare e colore dopo essiccamento e cottura, i materiali, meglio rispondenti alle qualità specifiche richieste per la produzione di forme vascolari di varia dimensione, ceramica fine e laterizi di qualità sono quelle afferenti alla formazione terravecchia ed alle argille di ficarazzi. questi risultati rafforzano quanto già poteva essere considerato più che verosimile dalle indagini archeologiche ed archeometriche recentemente effettuate sul territorio. già in passato, infatti, la sapienza empirica degli artigiani locali aveva raggiunto un livello tale da selezionare, a seconda della destinazione d’uso del manufatto, le materie prime più idonee. questo il più delle volte accadeva senza la necessità di correggere gli impasti. in altri casi le argille erano dimagrite con sabbia, oppure, r icorrendo ad opportune miscele tra varie qualità di argilla. le evidenze derivabili dai confronti esposti nel paragrafo precedente corroborano quanto appena affermato. in particolare, nel caso delle argille di ficarazzi, viene messo in evidenza anche un utilizzo eccezionalmente stabile nel tempo, anche se forzatamente circoscritto al solo agro palermitano: dalle fornaci di solunto dove si produssero anfore e ceramica da mensa o dispensa dall’età arcaica sino al periodo ellenistico-romano, a quelle dell’acqua dei corsari che si distinsero dal xvi secolo per la manifattura di mattoni per pavimentazione di ottima qualità (anche in maiolica). di contro, i materiali prelevati dal flysch numidico e dalle argille varicolori hanno mostrato, nella maggior parte dei casi, caratteristiche non propriamente idonee alla manifattura di ceramica di accettabile qualità, a causa di un assortimento granulometrico assai variabile e in genere non bilanciato, della presenza di minerali argillosi a reticolo espandibile nella frazione inferiore a 2 µm, e di un contenuto in cao il più delle volte troppo basso per garantire un sufficiente livello di vetrificazione alle temperature comunemente raggiunte nelle fornaci tradizionali (in genere inferiori o di poco superiori ai 1000°c). pertanto, l’utilizzo di queste argille dovrebbe essere stato, realisticamente, limitato e piuttosto episodico, di scarso interesse archeologico o storico-artistico e, soprattutto, circoscritto a tipologie di manufatti meno pregiate, quali laterizi (mattoni da costruzione e tegole) o, al più, vasellame grezzo ad impasto refrattario (qualora abbondantemente dimagrite con sabbia silicatica) che necessita di temperature di cottura più basse. e’ doveroso sottolineare che i risultati esposti in questa sede costituiscono solo la prima fase di una ricerca molto più vasta. essa è ancora in piena fase di sviluppo ed ha la finalità di costruire un’ampia quanto affidabile base di confronto per identificare e caratterizzare i numerosi centri di manifattura ceramica che hanno contribuito ad arricchire il patrimonio culturale siciliano. una ricerca del genere può avere, come preliminarmente dimostrato nei paragrafi precedenti, delle importanti ricadute nella soluzione di problematiche archeologiche e storiche, permettendo di acquisire nuovi criteri oggettivi per la valutazione della diffusione delle produzioni ceramiche locali, sia in ambito intrainsulare che extrainsulare, con la possibilità di valutare le attività sociali ed economiche dei singoli insediamenti, i loro livelli di evoluzione tecnologica e lo sviluppo nel corso dei secoli. 295 fig. 10 analisi discriminante di tutte le argille studiate e dei reperti ceramici di produzione locale, effettuata assumendo 4 gruppi: argille del flysch numidico; argille varicolori; argille della formazione terravecchia e coppe iato k-480; argille di ficarazzi, ceramica a vernice nera (imitazioni locali di forme in campana a), mattonelle da pavimentazione (xvi-xix secolo). discriminant analysis of the examined clay data set and of local ceramic artefacts, assuming four groups: flysch numidico (clays); argille varicolori (clays); terravecchia formation (clays and iato k-480 archaic cups); ficarazzi formation (clays, hellenistic black gloss plates and bowls and floor tiles of the xvi-xix centuries). definizione composizionale delle “argille ceramiche” ... bibliografia b. accordi (1958) il flysch oligocenico-aquitaniano dei monti nebrodi. eclogae geol. helvetiae, 51, 827. r. alaimo & g. montana (2003) scienza e archeologia: le analisi archeometriche. in “pantellerian ware. archeologia subacquea e ceramiche da fuoco a pantelleria”. s. santoro bianchi, g. guiducci, s. tusa. (eds.), dario flaccovio editore, palermo, p. 51-55. r. alaimo, r. giarrusso, i. iliopoulos, & g. montana (2000) coppe tipo iato k-480: indagini archeometriche finalizzate alla individuazione del centro di produzione. atti del 1° congresso nazionale della società italiana di archeometria aiar (verona 2-3 dicembre 1999). pàtron editore bologna, p. 405-417. r. alaimo, c. greco, i. iliopoulos & g. montana (2002) ceramic workshops in western sicily: solunto and mozia (vii-iii b.c.): a first approach through raw materials, fabric and chemical composition of ceramic artefacts. in “modern trends in scientific studies on ancient ceramics”. v. kilikoglou, a. hein, y. maniatis (eds.), british archaeological reports (bar), international series 1011, p. 207218. r. alaimo, i. iliopoulos, & g. montana (2003) le anfore puniche di solunto: discriminazione tra produzioni locali ed importazioni mediante analisi al microscopio polarizzatore. in “quarte giornate internazionali di studi sull’area elima” a cura di a. corretti. erice 1-4 dicembre 2000. scuola normale superiore di pisa – laboratorio di storia, archeologia e topografia del mondo antico, vol. i, p. 1-9. r. alaimo, g. bultrini, i. fragalà, r. giarrusso, i. iliopoulos, & g. montana (2004) archaeometry of sicilian glazed pottery. applied physics a – material science & processing, 79, p. 221-227. o. belvedere, a. burgio, i. iliopoulos, g. montana & f. spatafora ceramica a vernice nera di età ellenistica da siti della sicilia nord-occidentale: considerazioni tipologiche ed analisi archeometriche. mélanges de l’ecole française de rome. italie et méditerranée, (in corso stampa nel 2006). m. bello, a. franchino & s. merlini (2000) structural model of eastern sicily. memorie della società geologica italiana, 55, p. 61-70. f. bianchi, s. carbone, m. grasso, g. invernizzi, f. lentini, g. longaretti, s. merlini & f. mostardini (1989) sicil ia orientale: profi lo geologico nebrodi-iblei. memorie della società geologica italiana, 38, p. 429-458. h. m. bolli & j. b. sounders (1985) oligocene to holocene low latitude planktic foraminifera. in: bolli h. m., sounders j.b. and perch-nielsen k., eds., plankton stratigraphy. cambridge: cambridge university press. p. 175-262. p. broquet (1968) étude géologique de la région des madonies (sicile). thèse fac. sc. lille p. 797. a. brugnone (1877) osservazioni critiche sul catalogo delle conchiglie fossili di monte pellegrino e ficarazzi del marchese di monterosato. bollettino società italiana di malacologia, 3, p. 17-46. g. buccheri (1984) pteropods as climatic indicators in quaternary sequences a lower-middle pleistocene sequence outcropping in cava puleo (ficarazzi, palermo italy). palaeo, 45, 1, p. 75-86. p. bullock, n. fedoroff, a. jongerius, g. j. stoops & t. tursina (1985) handbook for soil thin section description . wine research publishers, wolverhampton uk. j. buxeda i garrigo´s (1999) alteration and contamination of archaeological ceramics: the perturbation problem. journal of archeological science, 26, p. 295–313. l. caflysch (1966) la geologia dei monti di palermo. rivista italiana di paleontologia e stratigrafia, xii, pp. 108, milano. r. catalano & b. d'argenio (1982) schema geologico della sicilia occidentale. in: r. catalano & b. d’argenio (ed.): guida alla geologia della sicilia occidentale. guide geologiche regionali, memorie della società geologica italiana, 24, p. 9-41. r. catalano, a. franchino, s. merlini, & a. sulli (2000) central western sicily structural setting interpreted from seismic reflection profiles. mem. soc. geol. it., 55, 5-16. r. catalano, s. merlini & a. sulli (2002) the structure of wester sicily, central mediterranean. petroleum geoscience, 8, 7-18. r. catalano, g. avellone, l. basilone, a. sulli, m. barchi, c. di maggio, r. sprovieri, b. abate, a. contino, m. gasparo & g. grimaldi (2005) note illustrative della carta geologica d’italia alla scala 1:50.000 del foglio 608 “caccamo”. progetto carg. m.a. cau ontiveros, p.m. day & g. montana (2002) secondary calcite in archeological ceramics: evalutation of alteration and contamination processes by thin section study. in “modern trends in scientific studies on ancient ceramics”. edited by v. kilikoglou, a. hein, y. maniatis. british archaeological reports (bar), international series 1011, p. 9-18. cipolla f., (1931) cave di argilla per laterizi in sicilia. bollettino associazione mineraria siciliana 19281932, p. 31-35. m.b. cita, & s. gartner, (1973) studi sul pliocene e gli strati di passaggio dal miocene al pliocene. iv. the stratotype zanclean foraminiferal and nannofossil biostratigraphy. rivista ital iana paleontologia e stratigrafia, 79, p. 503-558. r. colacicchi (1958) dicchi sedimentari del flysch oligomiocenico della sicilia nord-orientale. eclogae geol. helvetiae, vol. 51, 901. e. di stefano & d. rio (1981) biostratigrafia a nannofossili e biocronologia del siciliano nella località tipo di ficarazzi. acta naturalia dell’ateneo parmense, 17, p. 97-111. b. fabbri & m. dondi (1995) caratteristiche e difetti del laterizio. faenza editrice, p. 39-54. m.g. fulford & d.p.s. peacock (1984) excavations at carthage: the british mission. i, 2, sheffield, uk. v. kilikoglou, , a. hein & y. maniatis, (eds) (2002) modern trends in scientific studies on ancient ceramics. british archaeological reports (bar) international series 1011, archaeopress. a. hein, a. tsolakidou, i. iliopoulos, h. mommsen, j. 296 g. montana et al. buxeda i garrigos, g. montana & v. kilikoglou (2002) standardization of elemental analytical tecniques applied to provenante studies of archaeological ceramics: an interlaboratory calibration study. the analyst (royal society of chemistry), 127 (4), p. 542-553. m. j. hughes, (ed) (1981) scientific studies in ancient ceramics. british museum occasional paper, 19. s. iaccarino (1985) mediterranean miocene and pliocene planctic foraminifera. in h. m. bolli, j. b. saunders & k. perch-nielsen (eds.), plankton stratigraphy, cambridge univ. press., 1, p. 283314. laviano r. (1987) analisi mineralogica di argille mediante diffrattometria dei raggi x. in atti del workshop procedure di analisi di materiali argillosi. enea. collana di studi ambientali, pp. 215-232. lindahl a. & stilborg o., (ed) (1995) aim of laboratory analyses of ceramics in archaeology. almqvist & wiksell, stockholm. y. maniatis & m.s. tite, (1978) ceramic technology in the aegean world during the bronze age. in “thera and the aegean world” (c. dumas ed.), vol. i, london, p. 483-492. m. marchetti (1956) the occurrence of slide and flowage materials (olistostromes) in the terziary series of sicily. international geology congress mexico city proceedings. m. marsigli & m. dondi (1997) plasticità delle argille italiane per laterizi e previsione del loro comportamento in foggiatura. l’industria dei laterizi, 46, p. 214-222. g. montana, h. mommsen, i. iliopoulos, a. schwedt & m. denaro (2003) petrography and chemistry of thin-walled ware from an hellenistic-roman site at segesta (sicily). archaeometry, 45, 3, pp. 275389. l. ogniben (1960) note illustrative dello schema geologico della sicilia nord-orientale. rivista mineraria siciliana, 64-65, p. 183-212. d. p. s. peacock, (1982) pottery in the roman world: an ethnoarchaeological approach. london. p. s. quinn, r. alaimo, g. montana, (1998) calcareous nannofossil analysis of ceramics and probable raw materials from an ancient punic kiln site on the island of mozia, western sicily. journal of nannoplankton research, 20: 85–87. p. s. quinn (1999a) ceramic micropalaeontology: the analysis of microfossils in archaeological ceramics with special reference to its application in the southern aegean, unpublished ph.d. thesis, university of sheffield, england. p. s. quinn (1999b) a note on the behavior of calcareous nannofossils during the firing of ceramics. journal of nannoplankton research, 21: 31–32. p.m. rice, (1987) pottery analysis: a sourcebook, university of chicago press, chicago, il. g. ruggieri (1979) a "new stratigraphy" for the marine quaternary of italy . litoralia 9-10. g. ruggieri & r. sprovieri (1977) a revision of pleistocene stratigraphy. geologica romana. 16, p. 131-139. p. schmidt di friedberg (1964-65) litostratigrafia petrolifera della sicilia. rivista mineraria siciliana, 88-90, p. 80. g. seguenza (1873) studi stratigrafici sulla formazione pliocenica dell’italia meridionale. boll. comit. geol. d’it., 1-2, 29-45. shaw d.b., stevenson r.g., weaver c.e., bradley w.f. (1971) in griffin g.m. interpretation of x-ray diffraction data. in procedures in sedimentary petrology. carver r.e. edit., wiley and sons, new york, 554-557. f.p. shepard (1954) nomenclature based on sand-siltclay ratio. journal of sedimentary petrography, 24, 3, p. 131-158. r. sprovieri (1993) pliocene-early pleistocene astronomically forced and chronology of mediterranean calcareous plankton bio-events. rivista italiana di paleontologia e stratigrafia, 99, p. 371-414. r. sprovieri, e. di stefano, m. sprovieri (1996) high resolution chronology for late miocene mediterranean stratigraphic events. rivista italiana di paleontologia e stratigrafia, 102, p. 77-104. sprovieri, r., bonomo, s., caruso, a., di stefano, a., di stefano, e., foresi, l., iaccarino, s.m., lirer, f., mazzei, r., and salvatorini, g., 2002 – an integrated calcareous plankton biostratigraphic scheme and biochronology for the mediterranean middle miocene. riv . ital. paleont. e strat, 108, 2, p. 337-353. m.t. stark, r. bishop & e. miksa (2000) ceramic technology and social boundaries: cultural practices in kalinga clay selection and use. journal of archaeological method and theory, 7 (4), p. 295-331. terry r. d. & chillingar g. v. (1955) summary of “concerning same additional aids in studyng sedimentary formation” by m. s. shvetsov. journal of sedimentary petrology 25(3), pp. 229-234. tucker m. e. (1981) sedimentary petrology: an introduction. blackwell scientific pubblicatio, oxford. vassallo s. (1996) coppe iato k-480: tipologia e diffusione. quaderni del museo archeologico regionale “antonio salinas”, 2. 297 ms. ricevuto il 20 febbraio 2006 testo definitivo ricevuto il 31 ottobre 2006 ms. received: february 20, 2006 final text received: october 310, 2006 definizione composizionale delle “argille ceramiche” ... sess 2_16022011_tpr3.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 quaternary evolution of the montereale intermountain basin (central apennines): knowledge and open questions edi chiarini & elena la posta dipartimento difesa del suolo – servizio geologico d’italia ispra, roma corresponding author: e. chiarini <edi.chiarini@isprambiente.it> abstract: chiarini e. & la posta e., quaternary evolution of the montereale intermountain basin (central apennines): knowledge and open questions. (it issn 0394-3356, 2011) new data collected for the “antrodoco” 348 sheet of the geological map of italy at 1:50,000 scale permit the characterization of sedimentary events that have interested the montereale intermountain basin (aq) and the formulation of hypothesis on its quaternary evolution. riassunto: chiarini e. & la posta e., evoluzione quaternaria del bacino intermontano di montereale (appennino centrale): stato delle conoscenze e problemi aperti. (it issn 0394-3356, 2011) i nuovi dati raccolti per la realizzazione del foglio 348 “antrodoco” della carta geologica d’italia alla scala 1:50.000 permettono di caratterizzare gli eventi sedimentari che hanno interessato il bacino intermontano di montereale (aq) nel corso del quaternario e di formulare delle ipotesi sulla sua evoluzione. key words: geologic mapping, quaternary faults, stratigraphic log, lacustrine deposits. parole chiave: cartografia geologica, faglie quaternarie, log stratigrafico, depositi lacustri. 1. introduction the montereale depression the northernmost branch of the aterno catchment basin is characterized by drainage difficulties and during the historical time was the site of a shallow lake (v. de vecchis, pers. com.). its tectonic origin is widely accepted (blumetti, 1991; bagnaia et al., 1996; galadini et al., 2000; galadini & messina, 2001; 2004), although its evolution is almost unknown. the study of this intermountain basin is part of the ongoing research activity related to the “antrodoco” 348 sheet of the geological map of italy (1:50,000 scale). this paper reports on the results obtained through the geological and geomorphological analyses of quaternary deposits; the preliminary data of three stratigraphic logs obtained with a drilling survey are also discussed. the aim of the research is to provide new data on a poorly studied intermountain basin, that could improve the knowledge of the tectonic structures within a sector of the central apennines, characterized by a high seismicity testified by violent earthquakes during historical periods (blumetti, 1995). 2. geological setting and available data in this area a thrust front places the gran sasso unit (made up of triassic-miocene mainly carbonate succession) on the laga unit (upper tortonian-lower messinian turbidite deposits). the two units have been involved in the extensional phase since the early pleistocene. a normal fault system with an en-echelon pattern has been recognized within the sector of the upper aterno valley (galadini & galli, 2000; galadini et al., 2000). evidences of quaternary activity in the northernmost segments of the system are represented by the capitignano fault and the s. giovanni fault (basili, 1999; boncio et al., 2004; galadini & galli, 2000; galadini et al., 2000). the role of the capitignano fault in the quaternary evolution of the basin has been underlined by many authors (bagnaia et al., 1996; galadini et al., 2000; galadini & messina, 2001, 2004). the structural setting of the neighbouring areas and preliminary investigations of the bouguer anomaly trends (ferri et al., 2010) suggest the presence of two different depocentres: one corresponds to the topographically most depressed area, near the piedicolle inhabited zone, and another is situated at the foot of the north-eastern slope, in the hanging wall of the capitignano fault. drilling and geoelectric data acquired by enel (1969) in a study for the realization of an hydroelectric basin, allow to establish that the thickness of sediments at the mouth of the t. mozzano valley reaches 140 m. moreover, stratigraphy of an in-depth drilling, recovered from the italian geological survey (l. 464/84), indicates a thickness of at least 140 m close to the north-eastern slope, not far away from the capitignano village. 3. geomorphological and survey data the relevant morphological characters of the basin are the steep mountain front of m. civitella – colle leone with its evident triangular facets, the almost continuous glacis along the foothills that was formed by the coalescence of talus and alluvial fans and the large alluvial plain of the aterno river and its tributaries. the oldest deposits are scarce suspended sediments located along the north-eastern and 90 92 91 southern edges of the basin; they include a paleolandslide along the right slope of the mozzano valley (cacciuni et al., 1995). these deposits have presently no chronological constraints, and are displaced by quaternary faults and deeply dissected by erosion. different ratios of embedding relative to paleo-landsurfaces permit to consider them as part of different stratigraphic units. deposits with well preserved morphologies, cropping out along the north-eastern and southern foothills, can be referred to the late pleistocene. the holocene deposits consist of limited strips of flood terraces, a series of fans with apex embedded within the deposits of the late pleistocene and alluvial sediments of the present aterno river plain. many landslides occurred at the base of the triangular facets on the north-eastern slope and have accumulated within the stream valleys. reconstruction of the role of recent active tectonics in evolution of the capitignano fault is greatly hampered by lithostructural factors (brancaccio et al., 1986): on one hand, evident escarpments made up of laga flysch deposits, could derive from exhumation of older fault escarpments due to selective erosion; on the other hand, the fault escarpments on generic quaternary deposits, which are visible along the northernmost branch of the fault, are badly preserved. nevertheless, the consistent thickness of the deposits in the hanging wall of the fault, and the progradation of the holocene fans relative to the older ones, could be interpreted as geomorphologic clues of recent activity and reduction in time of fault movement rates respectively, according to the criteria defined by santangelo (2003, cum bibl.). the relations between the outcropping deposits and the s. giovanni fault are well known thanks to favourable field conditions. in fact, on a newly excavated cross section inside a quarry (near the village of s. giovanni paganica) the displacement and intense deformation of upper pleistocene slope deposits have been observed (cinti et al., 2010). 4. stratigraphic logs in order to reconstruct the stratigraphic framework considering a wider sedimentary record two boreholes (s2-pratorosolo, depth 65 m and s3piedicolle, depth 75 m) were drilled near the western depocentral area. a third borehole (s1casci, depth 100 m) has been drilled in the hanging wall of the capignano fault. geoelectric survey has been performed to drive the borehole localization. in the s2 core (fig. 1) two different depositional phases have been clearly distinguished with specific lithological characters. the basal part consists of etherometric calcareous breccias with subrounded clasts horizons of alluvial or combined alluvial-gravitational origin. these deposits are referable to the sediments cropping out in the area of s. giovanni paganica-castello, attributed to the early pleistocene (calabrian) (basili, 1999; galadini et al., 2000; galadini & messina, 2001; 2004). upward, the coarse sediments are gradually replaced by lacustrine whitish clayey silts and clays; an >3 m thick well-developed paleosol, ochre-like in colour, marks the end of this depositional phase. the deposits lack elements derived from the erosion of the laga flysch, and the siliceous component mainly consists of quartz grains and siliceous fossils deriving from the erosion of spongolithic limestones from the m. marine area. from 38 m to the surface an alluvial plain sedimentation, with palustrine episodes, takes place; in these deposits clasts of the laga flysch formation are frequent. the succession from the s3 borehole (fig.1) begins with lacustrine and palustrine deposits, with peaty levels and volcanic horizons and a meter thick brown paleosol. the volcanic ashes, still under examination, can be related to strombolian events from latium volcanic complexes (b. giaccio, pers. com. 2011). upward, cyclic sequences related to a fluvial and lacustrine environment (prevalence of thin, laminated horizons and peaty levels) occur. the most significant fluvial episode is over 15 meters thick and consists of well sorted sediments with fining upward sequences and palustrine episodes; in the fine grained levels an organic horizon has a radiocarbon ams age of 33082 +/450 yr bp. fig. 1 stratigraphic logs of s2 and s3 boreholes. stratigrafie dei sondaggi s2 ed s3. quaternary evolution of the montereale intermountain ... 92 ms. received: testo ricevuto il the interpretation of the succession drilled in the s1 borehole is quite complex and deserve a more complete analysis. until now, two main lacustrine phases, separated by thick layers of etherometric sediments with muddy matrix, have been recognized. coarse sediments are partly referable to gravity flow processes and partly to tractive currents. these high-energy processes could have determined unfavourable conditions for the preservation of volcanic horizons. 5. conclusions the preliminary results of this study provide indications on the sediment source areas and permit to tentatively reconstruct the earliest sedimentary phases that involved the intermountain basin. the breccias drilled in the s2 borehole and the overlying lacustrine sediments testify an early phase during which that sector did not receive the sediment supply from the laga flysch, cropping out in the northern and eastern areas. a fully-developed soil testifies the end of this phase and indicates a long period of morphological stability. the dubious reference of these events to the early pleistocene needs to be confirmed. the presence oh the volcanic horizons enables the preliminary attribution of the deepest sequences drilled in s3 to the middle pleistocene. the cyclic sequences of fluvial and lacustrine sediments drilled in the s3 borehole are likely controlled by the climatic changes during the middle-late pleistocene in a subsidence-driven regime. the last significant fluvial phase, including an organic horizon dated 33082 +/450 yr bp, has been followed by the marsh-lacustrine sedimentation that has been characterizing the basin until historical times. the correlation between s1, s2 and s3 cores is hard to establish due to the lack of marker and/or dated horizons at the present state of knowledge. the vertical lithofacies variation of the s2 and s3 cored successions suggests that these two adiacent sectors of the plain, very close and at the same elevation above sea level, had experienced radically different evolutions. the lack of lacustrine sequences and the limited thickness of alluvial deposits in the s2 borehole are relevant findings that could indicate that the two basin sectors were subjected to different vertical movements during the middle-late pleistocene. however, further elements and in-depth studies are required to support this hypothesis. in this regard, tephrostratigraphic analyses and new esr and osl datings are being established in order to obtain the required chronological constraints and verify those already available. further checks on the data collected can be carried out through paleomagnetic analysis of the oldest lacustrine deposits of the cores. lastly, palynologic and paleobotanic research on the successions can improve the understanding of the prevailing climatic and environmental conditions at the time of sedimentation, and consequently allow a more accurate assessment of the role played by tectonics in the evolution of the basin. acknowledgement the authors are very grateful to i. raffi for her kind revision of the english text and to b. giaccio for exchange of ideas and useful comments that improved the paper. references bagnaia r., blumetti a.m., de luca g., gorini a., marcucci s., marsan p., milana g., salvucci r. & zambonelli e. (1996) morfotettonica dei rilievi a nord della conca aquilana. il quaternario, 9 (1), 287-292. basili r., (1999) la componente verticale della tettonica plio-quaternaria enll’appennino centrale. ph. d. thesis, university of rome “la sapienza”, 108. blumetti a.m. (1991) evoluzione geomorfologica, attività tettonica quaternaria e paleosismicità in alcune depressioni tettoniche dell’appennino centrale. ph.d. thesis, university of camerino, 190 pp. blumetti a.m. (1995) neotectonic investigations and evidence of paleoseismicity in the epicentral area of the january-february 1703, central italy, earthquakes. in: serva l. & slemmons b. eds., perspectives in paleosismology, ass. en.geol., spec. publ., 6, 83-100. boncio p., lavecchia g. & pace b. (2004) defining a model of 3d seismogenic sources for seismic hazard assessment applications: the case of central apennines (italy). journal of seismology, 8 (3), 407425. brancaccio l., cinque a. & sgrosso i. (1986) elementi morfostrutturali ereditati nel paesaggio dell’appennino centro-meridionale. mem.soc.geol. it., 35, 869-874. cacciuni a., centamore e., di stefano r. & dramis f. (1995) evoluzione morfotettonica della conca di amatrice. studi geologici camerti, 2, 95-100. cinti f.r., pucci s., civico r., pantosti d., de martini p.m., cucci l., patera a., brunori c., pinzi s., gori s., falcucci e., pierdominici s., blumetti a.m., chiarini e., la posta e., papasodaro f., fiorenza d., vittori e., vannoli p., fracassi u., di bucci d., burrato p., sileo g., michetti a.m., cowie p. (2010) mapping of active faults and characterizing their seismic behavior (s5 project). final meeting of the seism. projects, roma. enel centro nazionale studi e progetti (1969) impianto di capitignano. ferri f., eulilli v., puzzilli l.m., calcaterra s. & pulsinelli c. (2010) geophysical surveys in some intermountain basins of the central apennines. 85° congr. soc. geol. it., sess.18, 623-624, pisa. galadini f. & galli p. (2000) active tectonics in the central apennines (italy) input data for seismic hazard assessment. natural hazard, 22, 225-270. galadini f. & messina p. (2001) plio-quaternary changes of the normal fault architecture in the central apennines (italy). geodinamica acta, 14, 321-344. galadini f., messina p. & sposato a. (2000) tettonica quaternaria nell'appennino centrale e caratterizzazione dell’attività di faglie nel pleistocene superiore-olocene. in: galadini f., meletti c., rebez. a. eds, le ricerche del gndt nel campo della pericolosità sismica (1996-1999), cnr-gndc, 157169. santangelo n. (2003) interazione tra tettonica recente e processi geomorfici. il quaternario, 16 (1), 27-34. january 15, 2011 15 gennaio 2011 e. chiarini & e. la posta sess 2_16022011_tpr3.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 the pollen fingerprint of the last interglacial in the south-eastern po plain fabio fusco lippia, pescara dip. di scienze della terra, università di firenze, firenze corresponding author: f. fusco <fabiommfusco@libero.it> abstract: fusco f., the pollen fingerprint of the last interglacial in the south-eastern po plain. (it issn 0394-3356, 2011) the last interglacial in the se po plain can be recognized by: i) a forest dynamics of four distinct phases, corylus>quercus->carpinus->fagus; ii) continuous presence and maxima of zelkova and evergreen quercus ; iii) quercus at 75%. these features are not recorded during the preceding and the subsequent warm-temperate intervals, and can be considered as distinctive of the last interglacial in the se po plain. riassunto: fusco f., l'impronta pollinica dell'ultimo interglaciale nell'area padana sud-orientale. (it issn 03943356, 2011) l'ultimo glaciale nel settore se della pianura padana può essere riconosciuto da: i) una dinamica forestale suddivisa in quattro distinte fasi, corylus->quercus->carpinus->fagus; ii) dalla presenza continua e dai valori massimi di zelkova e delle querce sempreverdi; quercus al 75%. tali tratti principali, non registrati negli intervalli caldo-temperati precedenti né in quelli successivi, possono essere considerati distintivi dell'ultimo interglaciale nella pianura romagnola. key words: pollen, last interglacial, eemian, vegetation dynamics, fagus. parole chiave: polline, ultimo interglaciale, eemiano, dinamica vegetazionale, fagus. l ong (over 150m) and continuously cored boreholes, labelled 223-s17, 240-s8 and 222-s2. (fig.1). in this extended abstract, only the pollen diagram from core 223-s17 is shown. pollen diagrams from cores s2 and s8 are not figured because they are similar to that of s17. 2. results and discussion the pollen diagram of core 223-s17 (fig. 2) shows two opposite pollen associations which testify two extreme vegetation landscapes: a non-forested (steppic) panorama, as the 1. introduction the po river plain is one of the major alluvial plain of europe and it was densely drilled in the last years for the geological mapping project of italy to scale 1:50.000 (carg project). as part of this huge project, the geological survey of regione emilia-romagna extensively drilled the late quaternary deposits of the se po plain. in the last years, a number of works concerning pollen (e.g., fusco, 1999), foraminifers, ostracods, radiocronologic and sedimentological data and their integration in a reliable chronostratigraphic framework (e.g., amorosi et al., 2004; amorosi & colalongo, 2005; notes to f° 222, 223, 240, 256 of carg project, and references therein) documents the depositional history, the stratigraphic architecture and the palaeoclimatic evolution of the romagna plain over the last 150 ky, suggesting that late quaternary sedimentation in the eastern po plain developed under a predominantly glacio-eustatic control. a cyclic sedimentation pattern (including continental, coastal and shallow-marine deposits) defines two transgressive-regressive sequences, deposited over the last two climatic cycles. the vegetation dynamics within the last interglacial (~mis 5e), a time interval poorly investigated in the po plain, and the subsequent substages (mis 5d-5a) is here reconstructed on the base of the detailed pollen diagrams from three fig. 1, location map of the boreholes. ubicazione dei sondaggi.  107 109 108 values (not maxima), with appearance of other (not all) warm-temperate trees; b) quercus (oak) phase, during which both deciduous and evergreen oaks attain their maxima (~75%). c) carpinus t. betulus (hornbeam) phase, during which carpinus appears and spreads. quercus decreases. picea (spruce) and abies (fir) are at high percentages. the most marked peak of abies occurs at the end of this phase. d) fagus (beech) phase, with fagus at ~25% on average, indicating its local spread over the plain from the back relieves. carpinus does not vary its values. quercus decreases. it is furthermore noteworthy the continuous and relative maxima of evergreen quercus and zelkova, taxa never abundant in late quaternary pollen profiles from n-italy. these peculiar pollen features are also recorded in s8 and s2 cores and they will never repeat in the subsequent warm-temperate intervals, making the last interglacial distinguishable from the succeeding interstadials. 2.3 the presence of fagus in the last interglacial it is well known that fagus is virtually absent in pollen profiles of central and mediterranean response of the vegetation to glacial (or stadial) climate, characterized by dominance of pinus, with bushes (artemisia and ephedra), non-arboreal elements, scarcity of trees, low floristic diversity, and low total pollen concentrations; a forested landscape (dominance of ap) due to warm-temperate (interglacial or interstadial) climate, characterized by high number of arboreal taxa, high floristic diversity, strong reduction of pinus and nap. the marked expansion of forests during the last interglacial is followed by two minor forest development referred to interstadials 5c and 5a. analogue vegetation dynamics occurs in core 240s8 and 222-s2. during these interstadials, in s17 poaceae and hygro-hydrophytes (mainly cyperaceae) spread markedly, when humid environments, to which they are linked, progressively reached the se po plain in their migration northwards as a result of marine transgression. 2.1 the pollen fingerprint of the last interglacial (eemian) in the se po plain a very interesting forest dynamics, composed of four phases, characterizes the last interglacial: a) corylus (hazel) phase, at the beginnings of the interglacial, with deciduous quercus (oak) at high fig. 2, core 223-s17: pollen diagram of selected taxa for the last interglacial (eemian, mis 5e) and subsequent stadials and interstadials. the pollen "fingerprint" of the last interglacial is given by: a clear forest dynamics in four phases (corylus->quercus->carpinus->fagus); quercus culmination at ~70%; the spread of fagus (~25%); the continuous presence and the relative abundance of zelkova and evergreen quercus (in circles) sondaggio 223-s17: diagramma pollinico dei principali taxa per l'ultimo interglaciale (eemiano, mis 5e) e i successivi stadiali ed interstadiali. l'impronta pollinica dell'ultimo interglaciale è data da: una chiara dinamica forestale in quattro fasi (corylus->quercus->carpinus->fagus); la culminazione di quercus a ~70%; la diffusione di fagus (~25%); la presenza continua e la relativa abbondanza di zelkova e delle querce sempreverdi (nei cerchi) f. fusco 109 ms. received: testo ricevuto il suggesting the onset of a brief cooling episode possibly reportable to the montaigu event. 3. conclusions the development of the last interglacial in the se po plain is characterized by a series of peculiar pollen aspects which make this warm period distinguishable from a palynological viewpoint. the unexpected presence of fagus in the last interglacial is a very interesting occurrence which makes this area a possible refuge area. references amorosi a. & colalongo m.l. (2005) the linkage between alluvial and coeval nearshore marine successions: evidence from the late quaternary record of the po river plain, italy. in: blum m.d., marriott s.b. & leclair, s.f. (eds.) fluvial sedimentology vii. international association of sedimentologists, special publ., 35, 257-275. amorosi a., colalongo m.l., fiorini f., fusco f., pasini g., vaiani s.c. & sarti g. (2004) paleogeographic and paleoclimatic evolution of the po plain from 150-ky core records. global planet. change, 40, 55-78. bertolani marchetti d. & soletti g.a. (1972) – la vegetazione del monte amiata nell’ultimo interglaciale. st. trid. sc. nat., 49, 59-177. follieri m., magri d. & sadori l. (1988).  250,000-year pollen record from valle di castiglione (roma).  pollen et spores, 30, 329-356. fusco f. (1999) palinologia ed evoluzione della flora, della vegetazione e del clima nel sodaggio s17. in: amorosi a., severi p., roveri m., correggiari a., preti m., tommasetti c., tarocco p., colalongo m.l., pasini g., vaiani s.c., fusco f., marchesini l., spadafora e., cibin u., zuffa g.g. & dinelli e. note illustrative della carta geologica d'italia alla scala 1:50.000. f. 223 ravenna, 127-130. mullenders w., favero v., coremans m. & dirickx m. (1996) analyses pollinique de sondages a venise (ve -i, ve-i bis, ve-ii). aardk. mededel., 7, 87-116. pini r., ravazzi c. & donegana m. (2009) pollen stratigraphy, vegetation and climate history of the last 215 ka in the azzano decimo core (plain of friuli, north -eastern italy). quat. sc. rev., 28, 1268-1290  europe during the last interglacial. when recorded in some sites, pollen of fagus occurs discontinuously and limited to very low percentages, as at azzano decimo (ne-italy, pini et al., 2009). at valle di castiglione (central italy) fagus is continuously present, but its values are again very low (follieri et al., 1988). fagus becomes abundant later on. by contrast, fagus spread over the se po plain during the final phase of the last interglacial with high values (~25% on average), which testify its presence in situ. this occurrence is surprising even if it is not isolated in italy: at venice (mullenders et al., 1996), fagus is recorded in the pollen zone referred to eemian (zone 14) at ~10% on average with peak of ~25%, consistently with core s17 and s8. at mt. amiata fagus is abundant (over 30%) in an warm interval referred to the riss/würm interglacial (=eemian) by u/th datings (bertolani marchetti & soletti, 1972). in core s2 the fagus-phase is absent because the pollen registration is truncated by a sand interval. high percentages and local occurrence of a beech forest could indicate the presence of a refuge area for the beech in the se po plain. 3.3 the post-interglacial at s17, a thick deposit of regressive sands abruptly concludes the fagus-phase and, consequently, the last interglacial. successively, the spread of shrubby-herbaceous communities with pinus and steppic elements signs the return to cold climatic conditions (mis 5d). all warm-temperate trees disappear. a development of temperate forests is again exhibited during 5c and 5a interstadials. forest dynamics is here characterized by the spread of warm-temperate trees, weaker than the preceding interglacial, and parallel profiles of fagus and carpinus which are joined in a common phase. quercus does not display marked peaks whereas zelkova and evergreen quercus are discontinuous and scarce. in core s17 an unexpected re-diffusion of pinus with artemisia is recorded within the 5c interstadial january 15, 2011 15 gennaio 2011 the pollen fingerprint of the last interglacial in ... sess 0_retro e indice edi.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 remote sensing and lidar applications in the alluvial geoarchaeology of ne italy andrea ninfo, alessandro fontana, paolo mozzi & francesco ferrarese department of geography ‘‘g. morandini’’,university of padua, padova, italy corresponding author: a. ninfo <andrea.ninfo@unipd.it> abstract: ninfo a. et al., remote sensing and lidar applications in the alluvial geoarchaeology of ne italy. (it issn 0394-3356, 2011) lidar technology, beside aerial photography and near infrared images, taken during summer, were used to investigate a large portion of the venetian-friulian plain. these researches allowed to discover a number of new archaeological traces and to map some sites with a submetric definition. riassunto: ninfo a. et al., utilizzo di telerilevamento e lidar nella geoarcheologia alluvionale dell'italia nordorientale. (it issn 0394-3356, 2011) la tecnologia lidar, la fotografia aerea obliqua e le immagini estive riprese nella banda dell'infrarosso sono state utilizzate nell'analisi di un'estesa porzione della bassa pianura veneto-friulana permettendo di documentare tracce archeologiche. le ricerche hanno portato all'individuazione di numerosi nuovi siti e della ricostruzione con un dettaglio submetrico di antiche aree urbane. key words: oblique aerial images, cropmarks, nir, dem, holocene, venetian-friulian plain. parole chiave: olocene, pianura veneto-friuliana, microrililevo, foto aeree oblique, cropmarks, soilmarks in italy until 2000 aerial images could be acquired only under the permission of aeronautica militare; also for this law restriction, previous researches dealing with geomorphology and archaeology used almost only zenithal photos at scale 1:50001:60.000. these were realized by national and regional administrations mainly for the construction of topographic maps. nevertheless, the use of remote sensing for archaeological survey had already brought to important results in the venetianfriulian plain, as for example the discoveries related with the city of cittanova-heraclia (tozzi & harari, 1984). in the last years specific projects considered large portions of ne italy and they validated indications obtained from remote sensing and digital terrain model (dem) with field surveys. the investigations were carried out in the framework ofthe project "via annia", funded by veneto region, padua municipality and a.r.c.u.s. s.p.a. (mozzi & ninfo, 2009) and the project "padova underground: goearchaeology at the roots of the city", sponsored by cariparo fundation (mozzi et al., 2010a) and "non-invasive investigations for the assessment and evaluation of the archaeological and paleoenvironmental resourses of altinum" funded by veneto region. between 2007 and 2010 ~30,000 oblique aerial images were acquired during 100 hours of dedicated low altitude flights, covering large portions of the plain from rovigo to aquileia. data were stored in a gis database through gps positioning. analyses of these images supported a huge amount of new data that were compared with information obtained through an almost complete review of the available aerial and satellite images, with a special focus on high-resolution platforms (i.e. quickbird). since the 80’, topographic microrelief has been widely used in ne italy to recognize and characterize the landforms of alluvial plain; detailed dem were obtained by interpolation of selected elevation spots of the 1:10,000 maps chosen as representative of the natural surface. in the last years the spreading of lidar (light detection and ranging) technology allow to survey large areas with a density generally of 1-10 point/m2 and ~5-20 cm of vertical accuracy. at the moment lidar data are available only for some parts of the plain, but fig. 1, lidar-deriver dem of the centre of padua. dem ottenuto da lidar del centro di padova. 194 196 195 among them some important ancient cities as padua, altinum and aquileia were surveyed. the researches were compared with field surveys which collected information about geomorphology, stratigraphy, chronology of the archaeological features identified with remote sensing (e.g. cropmarks, soilmarks and other elements related with ancient human activity and settlements of the past). in padua and in altinumthe lidar allowed to recognize the existence of a topographic anomalies coinciding with the ancient core of the city; padua has been settled since protohistory and the vertical succession of stacked living floors brought to the formation of an anthropic mound with an area of about 1.5 km2. this artificial hill is nicely evidenced by lidar-derived dem and has a maximum thickness of 6.5 m (ferrarese et al., 2007; mozzi et al., 2010b; in press). in fig. 1 the topography was filtered from the present buildings, thus the present ground surface is represented. stratigraphic investigations allowed to calculate the volumes built during the different cultural phases from 1200 bc to middle age, and to demonstrate that the mound mainly consists of iron age and medieval layering. a similar setting was detected near altinum, the roman city which was abandoned between v-vii century ad leading its people to settle permanently in the venice lagoon. the lidar survey highlights the existence of an archaeological mound with an elevation of about 3-4 m over the adjacent lagoon environment (mozzi et al., 2010c). altinum is the only large roman city in northern italy and one of the few in europe that has not been buried by medieval and modern cities. this setting allows spatial investigation through remote sensing (ninfo et al., 2009). figure 2 is a zenithal image taken at the end of july 2007 by realvista telespazio s.p.a., during severe drought, which caused water stress of the maize and soy crops. the image consists of a digital photos with pancromatic and near infrared radiation (nir), which is highly sensitive to vegetation health, highlighting the archaeological features. in fig. 2 the lighter crop marks show the subsurface presence of stones, bricks, or compacted soil; the dark ones correspond to depressed features like pits, spoliation hollows, canals, and paleo-channels filled with silty-clay sediments. the images reveal ancient urban fabric and waterways, the city walls and gates, the street network, dwellings with their internal divisions, and monumental buildings (e.g., theatre, odeon, amphitheatre, forum with emporia, and basilica). the geo-archaeological aerial survey along via annia path (about 200 km) has been carried out over the whole year, collecting images in fig. 2, digital enhanced false-color composite image (nir, red and green spectral bands) of the center of the roman city of altinum (telespazio s.p.a., rome, italy), with maize and soy cropmarks; b) interpretation of a)(ninfo et al., 2009) immagine digitale a falsi colori enfatizzata (combinazione delle bande spettrali nir, rossa e verde) del centro della città romana di altinum (telespazio s.p.a., roma italia) con cropmarks su mais e soia; b) interpretazione di a) (ninfo et al., 2009). remote sensing and lidar applications in the ... 196 ms. received: testo ricevuto il the different seasons with variable conditions of land use, soil moisture and vegetation growth. these different parameters strongly affect the visibility of the archaeological and palaeohydrographical features. before this extensive survey, among geomorphologists and archaeologists the common idea was that winter zenithal photos were the most suitable images for detecting traces of the ancient landscapes; the new data collected within these projects evidence that the best moment of acquisition to maximize the cropmarks and soilmarks response is at the end of periods of drought along the growing period of vegetation. another new concept is that oblique images on cropmarks have a particularly efficacy in detecting complex traces of little dimensions (e.g. ditches, necropolis, dwelling patterns) up to a centimetric detail. the possibility of flight with little aircrafts allows to collect images in very specific time windows, taking benefits from different light conditions and variable effects of shadow, that sometimes could enhance crops differential growth. to be noted that in the processing of the oblique images a long time is need to rectify them. moreover every oblique images could be corrected and georeferenced only for limited portion of it and a large number of them is needed to cover large extent. also the recent advances involving the sensors of aerial and satellite support new capability in cropmarks detection, specially with the wider use of hyperspectral sensors and the introduction of pancromatic scanners with an elevated geometric resolution (pixel of 1.0-0.4 m). the integration between high-precision dem and aerial images with a high resolution and, possibly, with pancromatic and nir bands allowed to collect a number of new data in a wide area of ne italy. the positive results achieved in the venetianfriulian plain suggest to apply this methodology in other similar areas, as for example the distal and coastal sector of po plain, between lombardy, emilia romagna and veneto regions. lidarderived dem are currentlyavailable only for some limited zones, but in the next years they will cover the whole national territory, as planned by environmental ministry. the examples presented in this paper focus on geoarcheology but, considering the aforementioned methods in a floodplain environment, many geomorphological and depositional aspects could be investigated with a high-resolution perspective. in this case the satellite images are important to support correlation of traces belonging to the same features, as for example different scroll-bar sequences formed by the same paleochannel. references bondesan a., fontana a., mozzi p., piovan s., primon s. (2010) la geomorfologia del terriotiro dell'annia. in rosada g., frassine m., ghiotto a. (eds), ...viam anniam influentibus palustribus aquis eververatam.... canova edizioni, treviso, 25-36. ferrarese, f., mozzi p., cervo & veronese f. (2006) high resolution dtm for the geomorphological and geoarchaeological analysis of the city of padua (italy). bar international series, 1568, 291-296. heritage g.l. & large a.r.g. (eds) (2009) laser scanning for the environmental science. wileyblackwell publishing, 302 pp. mozzi p. & ninfo a. (2009) la fotografia aerea obliqua per l'analisi geoarcheologica del territorio della via annia. via annia. adria, padova, altino, concordia, aquileia. in: veronese f. (ed.), via annia progetto di recupero e valorizzazione di un'antica strada romana. atti della giornata di studio, padova, 19 giugno 2008. il poligrafo, padova, 103-120. mozzi p., fontana a., piovan s., abba' t. (2010a) indagini geomorfologiche lungo il tracciato della via annia. in veronese f. (ed), via annia: adria, padova, altino, concordia, aquileia progetto di recupero e valorizzazione di un'antica strada romana. atti della ii giornata di studio, padova, 17 giugno 2010. il poligrafo, padova, 25-38. mozzi p., piovan s., rossato s., cucato m., abbà t., fontana a. (2010b) palaeohydrography and early settlements in padua (italy). il quaternario italian journal of quaternary sciences, 23(2bis), 268-282. mozzi p., fontana a., ninfo a., ferrrarese f. (2010c) geomorfologia e trasformazioni del territorio. in tirelli m. (ed), altino antica, dai veneti a venezia. marsilio, venezia. ninfo a., fontana a., mozzi p., ferrarese f. (2009) the map of altinum, ancestor of venice. science, 325, 577. ninfo a., mozzi p., ferrarese f., fontana a.,(in press) high resolution dems for the analysis of fluvial and ancient anthropogenic landforms in the alluvial plain of padua (italy). geografia fisica dinamica quaternaria. ninfo a., fontana a., mozzi p. (2010) il contributo del telerilevamento nello studio della via annia. in veronese f. (ed), via annia: adria, padova, altino, concordia, aquileia progetto di recupero e valorizzazione di un'antica strada romana. atti della ii giornata di studio, padova, 17 giugno 2010. il poligrafo, padova, 40-52. tozzi harari (1983) eraclea veneta. immagine di una città sepolta, parma. january 15, 2011 15 gennaio 2011 a. ninfo et al. sess 0_retro e indice edi.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 the acheulian phenomenon in western europe with a focus on italy nicoud elisa inrap/ umr 6130 cepam, france corresponding author: e. nicoud <elisa.nicoud@inrap.fr> abstract: nicoud e., the acheulian phenomenon in western europe with a focus on italy. (it issn 0349-3356, 2011) if the acheulian “culture” appears in western europe during 300.000 years (oxygen isotopic stage 16 to 8), it cannot be considered as a unic phenomenon because of the technical diversity within the industries (bifaces, tools, and chaînes opératoires). italian datas from notarchirico, castel di guido and torre in pietra are presented in the european chronospatial framework and used to discus the “out of africa” diffusion patterns and the reinvention hypothesis. riassunto: nicoud elisa, il fenomeno acheuleano in europa occidentale. (it issn 0349-3356, 2011) se la “cultura” dell’acheuleano persiste in europa occidentale per 300 000 anni (stadi isotopici dell’ossigeno 16 a 8), non deve essere considerata come un fenomeno unico perchè le industrie litiche sono molto diverse (bifacciali, strumenti o catene operative). i dati dei siti italiani di notarchirico, castel di guido e torre in pietra sono presentati nel quadro chrono-spaziale europeo. sono anche utilizzati per discutere i modeli della diffusione “out of africa” e la possibilità della reinvenzione locale. acheulian, biface, western europe, out of africa, diffusion patterns, bifacial piece acheuleano, bifacciale, europa occidentale, out of africa, modeli di diffuzione, pezzi bifacciale. the acheulian culture has been created in the xixth century by g. de mortillet to describe the lithic industries with handaxes found in the somme river valley, in northern france. then the word “acheulian” has been used to categrorize lower palaeolithic industries everywhere in the old world. if the biface is essential to the acheulian, its inner diversity and variablity has been denounced very often, even at the creation of the word (d’acy in mortillet, 1910). so, historically and substancially, the acheulian is a variability. what appears today to be a paradox and thus an intellectural deadlock (one world define many different things) seemed for mortillet a solution to answer his problematic, mostly relevant to the typochronological classification of the industries. the acheulian is a very confused paradigm because of the broad differences within its appearances. the diversity can be see within the industries: typologically (many classifications of the biface tried to clarify it), petrographically, technically and technologically. in addition, the sites are rare, above all, the ones with a reliable chronostratigraphical context. the dating must be taken with great care. also, the biface appears at 1.7 million years ago in africa but also at the end of the mousterian (mta). notarchirico level f, well-dated at 630 ka (piperno, 1999), is the first appearance of the handaxe in western europe. the upper limit of the acheulian is not clear and commonly, but artificially, is put at 300 ka, when the levallois concept massively appears. before ois 11, biface appearances are scarse in western europe but increase at this time, mostly in the paris basin (south of england, north of france). it become common in italy, spain andsouthern france after that, during ois 9. we tried to light up the vagueness of the acheulian by confronting the industries with a technological approch (nicoud, phd in progress). the biface is described by a structural analysis that allows us to understand its systemic role within the serie. three italian sites showing three very different lithic productions are used here to illustrate the speech: notarchirico in basilicata (piperno, 1999), torre in pietra (malatesta, 1978) and castel di guido in lazio (radmilli & boschian, 1996). thus, the biface seems to take almost three different forms, involving direct and major changes in the whole lithic production systems. the diversity shown by comparing the three italian sites but also all the western europe appearances, make us believe that the acheulian doesn’t exist as a homogeneous entity, in a technical or a chronological meaning. we can only understand the phenomenon by comprehending the uniqueness of each appearances. as we cannot see a homogeneous western europe during the acheulian, we propose to discuss here the acheulian diffusion patterns of the acheulian and consider the idea of a re-invention of the bifacial piece inside europe, maybe at different 192 193 193 ms. received: testo ricevuto il times and in different forms. also, because of technical links and chronological succession of some forms of the bifacial piece, it is possible to hypothetize an evolution of it and a diffusion inside western europe. references malatesta a. a cura di (1978) torre in pietra. quaternaria xx, roma, 205-580. nicaud e. (in progress) le phénomène acheuléen en europe occidentale. phd, université de provence, università degli studi di roma la sapienza. piperno m. ed. (1999) notarchirico, un sito del pleistocene medio antico nel bacino di venosa. osanna ed., venosa. radmilli a. & boschian g. (1996) gli scavi a castel di guido, il più antico giacimento di cacciatori del paleolitico inferiore nell’agro romano. origines, istituto italiano di preistoria e protoistoria di firenze, ets ed., pisa. january 15, 2011 15 gennaio 2011 the acheulian phenomenon in western europe with a ... sess 2_16022011_tpr3.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 ms. received: testo ricevuto il passive seismic stratigraphy in the pontina plain (latium, italy): first data lorenzo liperi, fabio meloni, pietro zizzari, giacomo catalano, fulvio colasanto & antonio gerardi regione lazio, direzione regionale ambiente, area difesa del suolo, roma corresponding author: f. colasanto <fcolasanto@regione.lazio.it> abstract: catalano g. et al., passive seismic stratigraphy in the pontina plain (latium, italy): first data. (it issn 0394-3356, 2011) the department of soil protection of the lazio region is using passive seismic stratigraphy (h/v signal methodology) in pontina plain, in areas characterized by sink-holes. the aim is to reconstruct the evolution of the carbonatic bedrock. riassunto: catalano g. et al., misure di sismica passiva nella pianura pontina (lazio, italia): primi risultati. (it issn 0394-3356, 2011) l’area difesa del suolo della regione lazio sta effettuando misure di rumore tramite tromino, in aree spesso interessate dal fenomeno sinkhole, confrontando i dati con le stratigrafie di sondaggi inseriti nel database regionale, per ricostruire l’andamento del substrato carbonatico. key words: passive seismic, h/v, pontina plain parole chiave: sismica passiva, h/v, pianura pontina the department of soil protection of the lazio region has long been interested in improving the standards of land management through seismic and geological prevention. since many years there are ongoing projects on seismic micro-zoning and sinkholes, both in well-defined areas that at a regional level. this also requires the constant acquisition of new data and the use of new technologies, to offer design enhancements. using the methodology h/v signals through the acquisition of noise (by tromino) is currently tested in a sample area of lazio (the pontine plain) in order to reconstruct the carbonate basement. there have been numerous measurements of noise in areas frequently affected by sinkhole phenomena by comparing the data with the known stratigraphic logs of the area (regional database). the measurements were made in area and along alignments. the vertical and areal distribution of amplification peak vs frequencies has allowed the reconstruction of maps of distribution of frequencies and, by comparison with the stratigraphic logs, to reconstruct the evolution of the carbonate bedrock. references castellano s., mulargia f. & bianconi l. (2005) – passive seismic stratigraphy: a new efficient, economic tecnique. geologia tecnica e ambientale, 5/2005, 76-102. 113 january 15, 2011 15 gennaio 2011 imp.santangelo& valutazione della pericolosità alluvionale delle conoidi del vallo di diano (salerno, italia meridionale) nicoletta santangelo1, antonio santo2, paola isabella faillace3 1 dipartimento di scienze della terra, università di napoli 2 dipartimento di ingegneria geotecnica – sezione geologia applicata, università di napoli 3 geologo, dottore di ricerca riassunto: santangelo et al., valutazione della pericolosità delle conoidi alluvionali del vallo di diano (salerno, italia meridionale). (it issn 0394-3356, 2006). l’area oggetto di questo studio è localizzata nel vallo di diano, un’ampia conca intermontana di età plio-pleistocenica situata nella parte meridionale della campania. alla base del versante orientale di questa depressione è presente un’ampia fascia detritica costituita in prevalenza da conoidi alluvionali coalescenti, con una età compresa tra il pleistocene medio e l’olocene. questa zona risulta caratterizzata da un notevole sviluppo di insediamenti urbani e attività agricole e/o industriali, che si è spesso realizzato senza tenere conto della possibile pericolosità dell’area rispetto ai processi alluvionali. l’obiettivo principale di questo lavoro è stato quello di riconoscere e di cartografare le conoidi attive e di definire la loro pericolosità, applicando un nuovo metodo recentemente proposto nella letteratura scientifica. il lavoro è stato, strutturato in più fasi. inizialmente è stato affrontato uno studio morfologico e morfometrico delle conoidi e dei loro bacini di alimentazione (27 esemplari) al fine di definire la tipologia di deposizione prevalente nelle conoidi ed il tempo di corrivazione dei bacini di alimentazione. contemporaneamente è stata effettuata un’analisi storica per cercare di comprendere lo stato di attività di questi corpi tramite un confronto tra la cartografia recente e quella storica, integrato con ricerche d’archivio che hanno documentato eventi alluvionali verificatisi nell’area negli ultimi 100 anni. il rilevamento sul campo ha consentito di raccogliere dati relativi alla tipologia dei depositi, alle interazioni esistenti tra gli apparati alluvionali e le strutture e/o infrastrutture, alla presenza di eventuali opere di sistemazione idraulica e alla loro efficacia. i dati raccolti sono stati utilizzati per definire le condizioni di pericolosità relativa tra le varie conoidi, applicando e parzialmente modificando, un metodo recentemente proposto dall’autorità di bacino del fiume po. in questo modo sono state definite quattro differenti classi di pericolosità relativa, comprese tra un alto grado (h4) ed un basso grado (h1). la maggior parte delle conoidi studiate ricade nelle classi h4 ed h3 e per almeno 8 di esse sussistono anche situazioni di alto rischio, legate all’interazione con centri urbani e altre infrastrutture. abstract: santangelo et al., alluvial fan flooding hazard assessment in the vallo di diano area (salerno, southern italy). (it issn 0394-3356, 2006). this paper deals with the problem of alluvial fan flooding in the piedmont areas of the campania region trying to apply a new method to evaluate the effective alluvial hazard conditions. piedmont areas are widespread all over the region and often present a high development of urban and/or agricultural settlements. the selected area is located at the foothill of the maddalena mountains, a nw-se trending elongated ridge which bounds to the east with the wide intramountain basin of “vallo di diano”. here a wide detrital talus made up by coalescent alluvial fans, ranging in age from middle pleistocene to holocene, is present. the geomorhological analysis firstly allowed the recognition of active and inactive alluvial fans by means of the individuation of their hydrographic apex; in this way 27 active fans have been selected for morphometrical analysis. then the main morphometric parameters (area, gradient, melton index) of each fan and hydrographic basin have been calculated in order to obtain information related to the main processes (stream or debris flow) prevailing in the basin/fan system and to calculate the concentration time. such data show that 24 out of 27 studied fans can be considered as “debris flow” dominated and that the concentration time of the hydrographic basins is always very short (lower than 1 hour). at the same time an historical analysis has been carried out to point out the state of activity of the fans during the last century. the collected data indicated that the “return time” of the main alluvial fan flooding events is more than 50 years. finally to define the relative hazard conditions among the studied fans, a recent method proposed in the scientific literature for the alluvial fans of the po river national authority has been applied, partly modifying it. four different classes of relative alluvial hazard have been distinguished from very high degree (h4) to low degree (h1). moreover, a hazard zonation inside the same alluvial fan has been proposed taking into account the main gradient variations. more than half among the studied fans belong to h4 and h3 classes and for at least 8 of them high risk conditions are determined by the interaction with urban centres and important roads. parole chiave: conoidi alluvionali, pericolosità alluvionale, colate detritiche, italia meridionale. keywords: alluvial fans, alluvial hazard, debris flow, southern italy il quaternario italian journal of quaternary sciences 19(1), 2006 3-17 1. premessa negli ultimi anni le ricerche geologiche e geomorfologiche sono state indirizzate sempre più frequentemente alla redazione di carte della pericolosità e del rischio per cause naturali. le metodologie prevedono applicazioni sia di tipo quantitativo che semiquantitativo, realizzate generalmente mediante l’utilizzo di gis sempre più sofisticati, che hanno permesso di effettuare delle perimetrazioni di dettaglio delle aree ad elevata pericolosità e rischio per fenomeni sia alluvionali che da frana. queste procedure sono ormai largamente utilizzate dai diversi enti pubblici quali per esempio le autorità di bacino. anche in campania, la redazione dei piani stralcio per l’assetto idrogeologico (psai) ha portato 4 n. santangelo, a. santo & p.i. faillace alla definizione di carte della pericolosità e del rischio soprattutto per quanto riguarda i fenomeni franosi ed i processi alluvionali in contesti di pianura. non sempre però è stato affrontato il problema della definizione della pericolosità e del rischio in contesti pedemontani laddove i processi alluvionali sono condizionati dalla presenza di conoidi attive. l’obiettivo principale di questo lavoro è stato quello di testare un metodo che permettesse di definire, agevolmente, lo stato di attività delle conoidi alluvionali in contesti pedemontani ai fini della redazione di carte della pericolosità e rischio. l’ area prescelta coincide con il settore pedemontano dei m.ti della maddalena, che si sviluppa per circa 40 km lungo il bordo orientale del bacino intermontano del vallo di diano ed è caratterizzato dalla presenza di numerose conoidi alluvionali coalescenti. la scelta è stata dettata anche dal fatto che su tale area alcuni degli scriventi hanno svolto attività di ricerca da più di un decennio e quindi per tali conoidi si possedevano dati storici su precedenti alluvioni, numerosi dati geomorfologici e stratigrafici ed una base vettoriale (volo del 1991) gentilmente resa disponibile dalla comunità montana del vallo di diano. le direttive seguite per definire lo stato di attività delle conoidi sono quelle proposte dalla fema (federal emergency management agency) del national research council degli stati uniti d’america (nrc, 1996). esse consistono in un’analisi geomorfologica dettagliata di carte topografiche in scala adeguata, supportata da dati di rilevamento. in particolare prevedono il riconoscimento delle porzioni attive/inattive di conoidi coalescenti attraverso l’identificazione dell’apice idrografico e dell’età dell’ultima attivazione; quest’ultima viene definita attraverso un’analisi storica e/o stratigrafica che dimostri l’esistenza di attività negli ultimi 100 anni (special flood hazard areas). e’ stato inoltre effettuato un rilevamento di dettaglio che ha consentito di raccogliere dati relativi alla tipologia dei depositi, alle interazioni esistenti tra gli apparati alluvionali e le strutture e/o infrastrutture, alla presenza di eventuali opere di sistemazione idraulica e alla loro efficacia. questo studio è stato integrato con un’analisi morfometrica delle conoidi e dei loro bacini di alimentazione, per definire i tempi di corrivazione dei bacini e per comprendere i processi deposizionali prevalenti nella messa in posto delle conoidi. i dati raccolti sono stati infine utilizzati per valutare la pericolosità rispetto ai processi alluvionali dell’area di studio seguendo e, parzialmente modificando, i l metodo proposto dall’autorità di bacino del po per la redazione del psai e riportato in sanna (2003). 2. inquadramento geologico dell’area il vallo di diano è una estesa depressione strutturale dell’appennino campano-lucano, allungata in direzione appenninica per circa 37 km, formatasi in seguito all’azione di importanti faglie regionali attive durante il pliocene-pleistocene (santangelo, 1991; ascione et al., 1992). in questo periodo il vallo di diano è stato sede di un grande bacino lacustre che successivamente si è trasformato in un’area palustre ed è stato bonificato in tempi storici per opera dei borboni (1800)1. esso è bordato ad occidente dai massicci calcarei, prevalentemente cretacici, del cilento (m.te cervati, m.ti alburni, m.ti della motola) e ad oriente dai m.ti della maddalena, una dorsale calcareo dolomitica di età triassico-giurassica, su cui poggiano stratigraficamente calcari pseudosaccaroidi, calciruditi e calcareniti di età maastrichtiano-eocenica. localmente sono presenti lembi trasgressivi di depositi arenaceo-argillosi di età miocenica mentre, nella zona meridionale della dorsale, tra sala consilina e padula, affiorano in finestra tettonica al di sotto delle unità carbonatiche, depositi calcareo-silico marnosi delle unità lagonegresi (fig. 1). lungo il bordo orientale del vallo è presente un’ampia fascia pedemontana che fa da raccordo tra i m.ti della maddalena ed il fondovalle; essa è costituita da diversi sistemi di conoidi alluvionale coalescenti, all’interno delle quali sono state riconosciute diverse generazioni di corpi sedimentari (santangelo, 1991). le più antiche sono attribuite al pleistocene medio superiore e sono ormai inattive mentre quelle recenti (pleistocene superiore olocene) costituiscono il raccordo con l’attuale fondovalle. i dati pluviometrici disponibili sull’area (pluviometro di sala consilina, 560 m.s.l.m.) analizzati sul periodo 1921-1950 (lippmann – provansal, 1987) riportano precipitazioni medie mensili non superiori ai 120 mm (concentrate nei mesi invernali ) ed un numero di giorni non piovosi superiore a 75 durante la stagione estiva. la piovosità media annuale, nello stesso periodo è compresa tra 1100 e 1250 mm annui. 3. analisi geomorfologica la prima fase della ricerca è stata rivolta al riconoscimento e alla perimetrazione delle conoidi alluvionali di prima e di seconda generazione e dei relativi bacini idrografici (fig. 1). 1 i primi tentativi di bonifica delle terre italiane iniziarono in epoca preromana ad opera dei pelasgi che tentarono di affrontare la bonifica del vallo con opere di una certa importanza, allargando gli inghiottitoi. i greci in seguito dovettero affrontare la bonifica di molte zone, e fra queste il vallo di diano. ai romani sono da attribuire le prime importanti opere; sarebbe, infatti, da attribuire a loro l’incisione della soglia del vallo presso polla (il gatta , riprendendo la notizia da g.b. pacichelli memorie dei viaggi in europa scrive: “ivi per darli più libero il trabocco ne poterono i romani aprire il varco”, ed ancora iannicelli a. sala consilina ed il vallo di diano scrive: ‘i romani iniziarono la regolazione delle acque col taglio della roccia presso campestrino’) e l’apertura di un lungo canale (oltre 2 km), detto fossato o intagliata, e di un ponte che lo sormonta (nel caso che si ritenga autentica un’iscrizione che afferma: pontem et foxatum roma p. fecit = la potenza di roma fece il ponte e il fossato). durante la dominazione borbonica (1786), ad opera di ferdinando iv di borbone, che diede incarico all’architetto pollio e successivamente al cavalier grasso, furono portati a termine lavori di bonifica (1796) tendenti a regolare i corsi d’acqua naturali, che possono ritenersi importanti per l’epoca (ass, busta 1595 vallo di diano). 5valutazione della pericolosità alluvionale ... fig. 1schema geologico e schema geomorfologico dell’area in studio. 1) depositi lacustri (olocene); 2) conoidi alluvionali attive (pleistocene sup. olocene) e numero di riferimento; 3) conoidi alluvionali inattive (pleistocene medio sup.); 4) flysch (miocene); 5) successioni calcareo-silico-marnose (giurassico sup. eocene); 6) depositi carbonatici (giurassico inf. eocene); 7) dolomie (triassico); 8) depositi carbonatici (cretaceo inf. sup.); 9) faglia; 10) sovrascorrimento; 11) bacino idrografico. geological and geomorphological sketches of the studied area. 1) lacustrine deposits (holocene); 2) active alluvial fan (upper pleistocene holocene) with referring number; 3) inactive alluvial fan (middle upper pleistocene); 4) flysch deposits (miocene); 5) marl and calacareous marls (upper giurassic eocene); 6) limestones (lower giurassic eocene); 7) dolomites (triassic); 8) limestones (lowerupper cretaceous.); 9) fault; 10) thrust; 11) hydrographic basin. 6 le conoidi di prima generazione, più antiche, affiorano solo in alcuni settori (a sud dell’abitato di padula, in corrispondenza del m.te tempone, ed a sud di m.te serra petrizzo) a quote comprese tra 520 e 650 m s.l.m. esse risultano inattive, profondamente reincise da alcuni corsi d’acqua in quanto sono state fagliate e sollevate per l’intensa attività tettonica registrata durante il tardo quaternario dalla faglia bordiera dei m.ti della maddalena. in particolare tale attività è testimoniata dalla presenza di scarpate di faglia che tagliano le conoidi nei pressi di sala consilina e dalla dislocazione di depositi lacustri ascritti al pleistocene medio, nei pressi di atena lucana.(santangelo, 1991; ascione et al., 1992). per tale motivo i depositi di questi antichi conoidi, ormai sospesi, sono conservati soltanto nella loro porzione apicale e sono costituiti da conglomerati ben cementati a clasti carbonatici, spesso ricoperti da suoli argilloso sabbiosi fortemente arrossati. le conoidi di seconda generazione sono, al contrario, rappresentate da ampi “ventagli”, di estensione molto diversa in funzione dei loro bacini alimentatori e nel complesso con un gradiente di pendio mediobasso. risultano costituite da ghiaie e conglomerati poco cementati a clasti carbonatici che contengono locali lenti di sabbie ed argille di colore marrone rossastro. dal punto di vista morfologico questi apparati multipli sono sia del tipo “sovrapposto” che del tipo “incastrato” (sensu bull, 1968): nel primo caso l’apice topografico e l’apice idrografico coincidono e i corpi deposizionali più recenti ed ancora attivi sono localizzati in zona apicale (fig. 2a). nel secondo caso l’apice topografico e l’apice idrografico non coincidono e la conoide attiva è localizzata in zona distale rispetto al fronte montuoso (fig. 2b). attraverso un attento esame dell’andamento delle curve di livello sulle carte topografiche c.t.r. in scala 1:10.000 della comunità montana del vallo di diano (1991), e una analisi fotointerpretativa, sono state riconosciute 27 conoidi attive; per ognuna di esse sono stati individuati l’apice idrografico ed eventuali lobi di deposizione relitti. il lavoro è stato eseguito con il supporto del software gis arc view. l’utilizzo di questo software ha inoltre consentito il calcolo dei principali parametri morfometrici delle conoidi e dei loro relativi bacini di alimentazione (tab. 1 e tab. 2). tali parametri sono stati utilizzati sia per risalire alla tipologia di trasporto prevalente nella messa in posto delle singole conoidi, sia per calcolare alcuni indici necessari per valutare la loro pericolosità . 3.1. tipologia di trasporto per individuare la tipologia di trasporto prevalente è stato utilizzato un metodo indiretto di tipo morfometrico, basato sulle relazioni esistenti tra la pendenza della conoide (ic) ed un indice adimensionale (indice di melton, mel) indicante la rugosità del bacino. si è utilizzato questo criterio morfometrico in quanto in campagna, purtroppo, le esposizioni di sezioni stratigrafiche naturali sono rare. la definizione del tipo di trasporto prevalente (stream flow, misto, debris flow) risulta utile in quanto consente di avere delle informazioni sull’intensità relativa degli eventi alluvionali. in questo modo possono essere individuate le conoidi a prevalente trasporto da debris flow che rappresentano le aree potenzialmente soggette ad eventi alluvionali più intensi. i primi studi mirati a definire i rapporti tra la forma delle conoidi alluvionali e quella dei loro bacini di alin. santangelo, a. santo & p.i. faillace fig. 2 conoidi alluvionali sovrapposte (a) ed incastrate (b) con ubicazione dell’apice topografico e dell’apice idrografico (da bull, 1968 modificato). superimposed alluvial fans (a) and entrenched alluvial fans (b) with location of the topographic and hydrographic apex (by bull, 1968 modified). 7 mentazione si devono a melton (1965) che constatò che la pendenza di una conoide non dipende esclusivamente dalla variazione della granulometria del materiale lungo la superficie di una conoide come sostenuto da eckis (1928) e blissenbach (1954), ma che invece essa è strettamente legata all’area e all’energia di rilievo del suo bacino di alimentazione. melton osservò che le conoidi alluvionali più estese e a minor pendenza sono legate esclusivamente a processi fluviali ed associate a grandi bacini di alimentazione con bassa energia di rilievo. invece conoidi più piccole e pendenti, dominate da meccanismi di messa in posto di tipo debris flow sono associate a bacini di area molto minore e ad elevata energia di rilievo. da questo studio egli riuscì a ricavare un indice adimensionale per caratterizzare i bacini di alimentazione, denominato indice di melton (mel), dato dal rapporto: mel = ab –0,5 (qb max qb min) (1) dove qb max e qb min rappresentano rispettivamente valutazione della pericolosità alluvionale ... tab. 1 parametri morfometrici dei bacini idrografici. ab = superficie del bacino; σl = lunghezza totale del corso d’acqua; qb max = quota massima; qb min = quota minima; ib = gradiente medio. morphometric parameters of the hydrographic basins. ab = drainage basin area; σl = total length of the streams; qb max = maximum elevation; qb min = minimum elevation; ib = mean gradient. ab σl qbmax qbmin bacini (km2) (km) (m) (m) ib (%) 1 1,4 2,9 1200 540 29,5 2 0,75 0,9 1110 470 17,3 3 1,45 2,8 1100 520 22,6 4 1,78 2,9 1221 480 26,6 5 5,5 10,2 1285 470 9,22 6 0,35 0,3 680 500 33,3 7 2,94 4,6 1289 480 10,7 8 8,37 12 1289 480 17,4 9 4,87 10 1310 480 11,1 10 2,63 6,1 1230 490 23,7 11 6,93 18,9 1450 530 19,1 12 1,2 3,2 920 470 23,7 13 2,05 6 1350 510 16,3 14 0,76 1,6 1240 550 2 15 0,07 0,3 950 650 50 16 2,76 7,4 1410 600 20 17 0,9 1,5 1460 600 47 18 0,65 2,1 1340 550 42,3 19 1 2,4 1490 570 25 20 3,66 11,1 1410 560 21,6 21 0,73 1,9 1000 530 28,4 22 6,75 16,9 1450 530 9,62 23 4,4 9,68 1290 550 16,2 24 2,99 4,6 1245 550 17,8 25 6,98 19,4 1310 600 19,9 26 3,59 10 1440 570 13,8 27 4,39 12,6 1500 550 23,4 tab. 2 parametri morfometrici delle conoidi alluvionali del vallo di diano. ac = superficie della conoide; qc max = quota massima; qc min = quota minima; ic = gradiente medio. morphometric parameters of alluvial fans. ac = fan area; qc max = apex elevation; qc min = elevation of fan toe; ic = mean gradient. ac qcmax qcmin bacini (km2) (m) (m) ib (%) 1 0,37 560 450 13,7 2 0,13 470 450 5 3 0,25 520 450 8,3 4 0,14 480 450 6 5 0,36 470 450 2,67 6 0,04 500 450 20 7 0,21 480 450 5,3 8 0,46 480 450 3,9 9 0,33 480 450 5,8 10 0,41 490 450 5,2 11 1,3 530 450 5,8 12 0,2 470 450 3,5 13 0,44 510 450 7,9 14 0,55 550 450 12,3 15 0,4 600 450 22,5 16 0,75 620 450 14,3 17 0,32 590 460 21,3 18 0,18 540 460 13,7 19 0,77 570 460 10,5 20 0,6 560 460 10 21 1,22 530 470 5,9 22 1,46 530 460 4,3 23 1,22 550 470 5,7 24 0,57 550 470 4,7 25 6,92 580 470 3,07 26 3,4 570 470 3,4 27 1,48 550 480 3,5 8 la quota massima e minima del bacino, ed ab la superficie del bacino stesso, e lo confrontò con la pendenza ic delle conoidi, ricavando l’equazione: ic (°) = a [ (qb – qb min) ab –0,5] n . (2) dove a ed n sono dei parametri adimensionali calcolati su base statistica. questa relazione è stata in seguito utilizzata da diversi autori (ryder, 1971; kostaschuk et al., 1986; jackson et al.,1987; hrvey, 1988; pasuto et al ,1992; marchi et al., 1993;1995; d’agostino, 1996) per distinguere le conoidi sulla base della tipologia di deposizione prevalente. tali studi, effettuati in diversi contesti climatici ed ambientali (stati uniti, canada, messico, nuova zelanda; kostaschuk et al., 1986; ryder, 1971; jackson et al., 1987; harvey, 1988; de scally & owens, 2004) e supportati da un’analisi di campo, hanno dimostrato una buona attendibilità del metodo. in italia la relazione ic/mel è stata applicata da pasuto et al. (1992) su sistemi di conoide dell’avisio, nelle dolomiti, unitamente ad evidenze emerse dal rilevamento sul terreno, per discriminare i sistemi bacinoconoide a rischio di debris flow. marchi et al. (1993; 1995) hanno utilizzato il medesimo approccio per sette zone delle alpi orientali, confermando le osservazioni morfometriche con osservazioni storiche sui fenomeni di elevata intensità. sulla base di questi studi si è provato ad applicare questa metodologia anche alle conoidi del vallo di diano. per ogni sistema “bacino-conoide” sono stati quindi calcolati i due parametri, mel e ic° (tab. 3). prima di procedere con la comparazione fra i due parametri, è stata valutata la significatività della correlazione tra le due variabili; l’analisi della correlazione ha evidenziato una valore di r di pearson molto significativo (p < 0.01) e pertanto si è proceduto alla costruzione del grafico di fig. 3. la distribuzione ottenuta risulta simile a quella riscontrata dallo studio di pasuto et al. (1992) e da marchi et al. (1993) che, sulla base di riscontri sul campo, hanno evidenziato che la pendenza delle conoidi risulta influenzata dalla tipologia dei processi deposizionali piuttosto che dalle caratteristiche litologiche dei bacini di alimentazione. gli aa. hanno differenziato le conoidi da loro studiate in tre gruppi principali: quelle a più basso gradiente e con indici di melton (mel) inferiori a 0.25 risultano caratterizzate da trasporto prettamente fluviale, quelle con mel maggiore di 0.5 da processi tipo debris flows; quelle con gradiente intermedio (0.25 < mel < 0.5) rappresentano, invece, le conoidi originate da un trasporto di tipo misto. l’analisi del grafico mel-ic (fig. 3) consente di affermare che il vallo di diano è caratterizzato da un cospicuo numero di conoidi con valori medi sia di pendenza sia di indice di melton, mentre esistono due gruppi estremi che potrebbero essere associati rispettivamente a processi prevalenti di tipo debris flow (n° 14, 15, 17, 18, 19) e di tipo selettivo (n° 5, 8 e 25). per discriminare in maniera più precisa tra questi due gruppi si può seguire il suggerimento di d’agostino n. santangelo, a. santo & p.i. faillace tab. 3 gradiente medio, indice di melton; ed equazione di d’agostino di tutte le conoidi studiate. mean gradient (ic), melton’s ruggedness number (mel) and d’agostino’s equation for all the studied fans. bacini ic (°) mel) 7-14mel 1 7,8 0,56 -0,80923 2 2,9 0,74 -3,34612 3 4,7 0,48 0,256707 4 3,4 0,56 -0,77564 5 1,5 0,35 2,13476 6 11,3 0,3 2,740423 7 3 0,47 0,394543 8 2,2 0,28 3,085162 9 3,3 0,38 1,734475 10 3 0,46 0,61175 11 3,3 0,35 2,107293 12 2 0,41 1,248913 13 4,5 0,59 -1,21354 14 7 0,79 -4,08078 15 12,7 1,13 -8,87451 16 8 0,49 0,174122 17 12 0,91 -5,69127 18 7,8 0,98 -6,71824 19 6 0,92 -5,88 20 5,7 0,44 0,77977 21 3,38 0,55 -0,70131 22 2,5 0,35 2,042486 23 3,3 0,35 2,061064 24 2,7 0,4 1,372996 25 1,7 0,27 3,237655 26 2 0,46 0,571642 27 2 0,45 0,652256 fig. 3 – classificazione delle conoidi alluvionali del vallo di diano sulla base della pendenza della conoide e dell’indice di melton. classification of the alluvial fans of vallo di diano on the basis of the fan slope and the melton’s ruggedness number. (1996) secondo cui, in via cautelativa, i trasporti di tipo misto possono essere accorpati nei debris flow/flood utilizzando come linea di separazione tra le due categorie di bacini/conoide la retta di equazione: ic° = 7 – 14mel applicando tale equazione al grafico ottenuto per le conoidi del vallo di diano si può osservare come cadano al di sotto di questa retta, e cioè soddisfino la disequazione ic° < 7-14 mel, soltanto le conoidi n° 5, 8 e 25 che risultano quindi le sole ad essere caratterizzate da processi di tipo selettivo. (fig. 3 e tab. 3) 3.2. tempo di corrivazione i parametri morfometrici dei bacini sono stati utilizzati anche per calcolare il tempo di corrivazione, cioè il tempo impiegato dalle acque d'afflusso meteorico a raggiungere la sezione di chiusura, partendo dai punti più alti e più lontani del bacino. questo parametro, che è funzione della morfologia, delle litologie affioranti e della copertura vegetale, è stato calcolato utilizzando la formula di giandotti (1934): tc(h) = [4√ab + 1.5lp] / [0.8 √(qbm-qb min)] dove ab rappresenta la superficie del bacino, lp la lunghezza dell’asta principale, qbm la quota media del bacino e qb min la quota minima del bacino. per il calcolo del tc è stato necessario calcolare la qbm del bacino la cui formula è: qbm = σ [ai qi/2]/ab dove qi = quota (m.s.l.m.) delle singole fasce altimetriche, pari alla media delle quote delle due isoipse che le delimitano; ai = area (in m2) delle singole fasce di altitudine. per quest’ultimo parametro è stata considerata un’equidistanza tra le isoipse di 50 m e le aree racchiuse tra di esse sono state calcolate con l’utilizzo di un software gis . dai risultati (tab. 4) si evince che la maggior parte dei corsi d’acqua impiega dai 30 ai 50 minuti per percorrere l’intero bacino e raggiungere i settori apicali delle conoidi alluvionali. tali tempi dunque risultano estremamente bassi; solo per tre conoidi, e precisamente per la 10, la 22 e la 25 essi superano di poco l’ora, ma sono comunque da ritenersi tempi molto brevi soprattutto in caso di eventi idrologici estremi. 4. analisi dello stato di attività per individuare i settori di conoidi alluvionali attivi negli ultimi 100 anni è stato effettuato un confronto tra la situazione topografica attuale e quella risultante dalla cartografia storica (i.g.m.i., 1908). contemporaneamente sono state svolte ricerche presso archivi di stato ed altri enti pubblici (genio civile, istituti idrografici, comunità montana) per recuperare documenti che testimoniassero eventi passati, sono state raccolte in sito testimonianze degli abitanti e, solo in alcuni casi, sono stati censiti degli eventi alluvionali che hanno coinvolto siti archeologici o monumentali e alcune costruzioni. dal punto di vista cartografico si è analizzato soprattutto l’andamento dell’alveo principale, per evidenziare eventuali spostamenti del tracciato fluviale. in alcuni casi, inoltre, sono state riconosciute evidenze di fenomeni di deposizione recente sul corpo della conoide. questi ultimi sono stati individuati grazie alla presenza di numerose anomalie delle isoipse sulle basi topografiche in scala 1:10.000 del 1990, che delineavano la presenza di antichi lobi di distribuzione (fig. 4). in parecchi casi si è poi riscontrato che sulla cartografia storica del 1908, tali aree risultavano caratterizzate da deposizione in atto. casi significativi, sono quelli del tratto terminale del vallone dei serpenti (n° 9), quello del vallone carbonaro (n° 10) in cui sono molto ben evidenti i lobi deposizionali attivi nel 1908 e quello del vallone della cerasa (n° 11). il tratto terminale del vallone s. angelo (n° 23), già a fine xviii secolo iniziava ad approfondirsi con forti evidenze di attività deposizionale. 9valutazione della pericolosità alluvionale ... tab. 4 parametri morfometrici utilizzati per il calcolo del tempo di corrivazione dei bacini (tc). ab = superficie del bacino; lp = lunghezza dell’asta principale; qb m = quota media; qb min = quota minima; tc = tempo di corrivazione. morphometric parameters used for calculating the hydrographic basin concentration time (tc). ab= drainage basin area; lp= length of main stream; qb m = mean elevation; qb min = minimum elevation; tc = concentration time. ab lp qbma qbmin tc bacino (km2) (km) (m) (m) (minuti) 1 1,4 1,67 897 560 30’ 2 0,75 0,87 715 470 23’ 3 1,45 2,3 873 520 33’ 10 2,63 3,12 767 490 50’ 11 6,93 6,32 1050 530 66’ 12 1,2 1,91 615 470 45’ 13 2,05 3,44 1001 510 37’ 14 0,76 0,82 833 550 21’ 15 0,07 0,31 770 650 11’ 16 2,76 3,57 1136 600 39’ 17 0,9 1,34 1063 600 20’ 18 0,65 1,39 852 550 23’ 19 1 2,36 1010 570 27’ 20 3,66 4,08 1019 560 48’ 21 0,73 2 695 530 38’ 22 6,75 5,2 989 530 64’ 23 4,4 3,78 941 550 53’ 24 2,99 3,67 801 550 59’ 25 6,98 4,98 944 600 73’ 26 3,59 4,84 1070 570 50’ 27 4,39 4 1063 550 48’ durante il lavoro di rilevamento è stato poi possibile raccogliere dagli anziani del luogo delle testimonianze orali relative ad eventi alluvionali che hanno interessato ripetutamente (fine 1800, 1922, 1950, 1962, 2004) le zone delle conoidi n° 8, 16, 17, 18, 19 ed hanno comportato sia fenomeni di trasporto solido che allagamenti dei primi piani degli edifici. il caso più esemplare e meglio documentato che testimoni l’attività storica di queste conoidi resta comunque quello della conoide del t. fabbricatore (n° 25), nella cui zona apicale è stata costruita nel 1306 la certosa di padula, uno dei complessi monastici più importanti dell’italia meridionale. prima che il corso d’acqua fosse deviato, esso scorreva a poca distanza dalla cinta muraria, e ciò è stato narrato anche in alcuni documenti storici (genio civile, 1858; pesce, 1889). nel 1857 l’abbadia fu colpita da un alluvione che ricoprì parte delle sue mura esterne e parte del cortile interno (fig. 5). oltre a questo evento, ve ne sono stati altri che hanno interessato la certosa, e precisamente durante il 1859, 1876, 1881, 1900, come testimoniano altri documenti storici (budetta et al., 2000). a seguito di ciò il consorzio di bonifica del vallo di diano effettuò la sistemazione idraulica del t. fabbricatore e la sua deviazione per evitare ulteriori inondazioni all’interno della certosa. sulla base dei confronti cartografici e delle fonti storiche raccolte è dunque possibile affermare che, negli ultimi 100 anni, la maggior parte delle conoidi studiate è stata soggetta a sensibili modificazioni e, in taluni casi, è stata interessata da eventi alluvionali significativi; pertanto tali aree, secondo la definizione del nrc (1996), sono da considerarsi sicuramente attive. 5. censimento delle opere idrauliche i dati sinora raccolti consentono di affermare che tutte le conoidi del settore orientale del vallo di diano risultano attive (anche se gli eventi alluvionali estremi, dedotti in base all’analisi storica, hanno tempi di ritorno maggiori di 50 anni) e sono sottese da bacini con tempi di corrivazione molto bassi; la maggior parte di esse inoltre, presenta un’alta probabilità ad essere interessata da fenomeni tipo debris flow. per procedere ulteriormente nella individuazione delle aree a maggior grado di pericolosità e rischio sono stati eseguiti dei sopralluoghi mirati ad un censimento delle modificazioni antropiche degli ultimi decenni, sia in termini di opere idrauliche (deviazioni dei corsi d’acqua, sistemazioni dei bacini imbriferi ecc.), sia per quanto riguarda le interazioni che le conoidi hanno con le aree di recente espansione dei centri abitati. questi ultimi infatti, negli ultimi trenta anni, hanno subito una notevole espansione anche verso i settori montuosi, andando ad interferire con le conoidi attive e determinando, talora, situazioni di alto rischio. 10 n. santangelo, a. santo & p.i. faillace fig. 4 a) le anomalie delle isoipse suggeriscono la presenza di un lobo di deposizione; b) il confronto con la cartografia storica del 1908 testimonia la presenza di deposizione attiva nella stessa area. 1) lobo deposizionale; 2) alveo attivo. a) anomalies in the contour lines suggest the presence of an ancient depositional lobe; b) comparison with historical maps shows that deposition was active in the same area during 1908. 1) depositional lobe; 2) active channel. fig. 5 portale di ingresso della certosa di padula completamente sepolto dagli eventi alluvionali di fine 1800. foto storica da budetta et al., 2000). entrance of padula’s abbey buried by sediments deposited during the alluvial events of the end of 1800. historical photo by budetta et al., 2000). 11valutazione della pericolosità alluvionale ... fi g. 6 c ar ta g eo m or fo lo gi ca d el le c on oi d i d el v al lo d i d ia no . 1 ) c on oi d e at tiv a e su o nu m er o d i r ife rim en to ; 2 ) a p ic e id ro gr af ic o; 3 ) a re a co n ev id en za d i a gg ra d az io ne in e p oc a st or ic a; 4 ) l ob i d ep os iz io na li at tiv i; 5) lo b i d i d ep os iz io ne r el itt i; 6) t ra cc ia to d el c or so d ’a cq ua d es un to d al la c ar to gr af ia d el 1 90 8; 7 ) a re e d i d ep os iz io ne a tt iv a ne l 1 90 8; 8 ) s ub st ra to c al ca re o; 9 ) a lv eo in ca ssa to ; 10 ) p ro b ab ile li ne a d i d ef lu ss o in c as o d i e so nd az io ne ; 11 ) al ve o st ra d a su c on oi d e; 1 2) b ru sc a d ev ia zi on e d i a lv eo n at ur al e e/ o ar tif ic ia le ; 13 ) al ve o co n si st em az io ne t ra sv er sa le e /o la te ra le ; 1 4) t ra tt o d i s tr ad a o au to st ra d a p ot en zi al m en te e so nd ab ile ; 1 5) p un to c rit ic o p er r id ot ta s ez io ne d el l’a lv eo . g eo m or p ho lo gi ca l m ap o f th e al lu vi al f an s of t he v al lo d i d ia no a re a. 1 ) a ct iv e al lu vi al f an w ith r ef er rin g nu m b er ; 2) h yd ro gr ap hi c ap ex ; 3) p or tio n of a llu vi al f an w ith e vi d en ce o f ag gr ad at io ns d ur in g hi st or ic al t im e; 4 ) a ct iv e d ep os iti on al lo b es ; 5) in ac tiv e d ep os iti on al lo b es ; 6) t ra ck o f riv er in fe rr ed f ro m h is to ric al m ap ; 7) a re as o f ac tiv e d ep os iti on d ur in g th e 19 08 ; 8) li m es to ne s ; 9) en tr en ch ed a ct iv e ch an ne l; 10 ) p ro b ab le lo w p at h d ur in g an a llu vi al e ve nt ; 1 1) c ha nn el s ub st itu ite d b y a ro ad o n th e al lu vi al fa n; 1 2) a b ru p t d ev ia tio n of n at ur al a nd /o r ar tif ic ia l c ha nn el ; 1 3) a ct ive c ha nn el w ith t ra ns ve rs al a nd /o r la te ra l h yd ro lo gi ca l w or ks ; 1 4) s tr et ch o f r oa d o r m ot or w ay p ot en tia lly fl oo d ab le ; 1 5) c rit ic al p oi nt fo r re d uc ed c ha nn el s ec tio n. in figura 6 ed in tabella 5 è riportata la sintesi di queste osservazioni. per quanto riguarda le opere idrauliche, si è potuto constatare che i canali alimentatori delle conoidi n° 8, 24, 25, 26 sono stati cementificati e imbrigliati nella porzione apicale; pertanto le loro naturali aree di recapito sono state spostate artificialmente più a valle. in alcuni casi, come al t. fabbricatore (n° 25), la realizzazione di nuovi alti argini artificiali e di briglie trasversali ha sicuramente ridotto di molto la possibilità di esondazione e di trasporto solido anche se, in questa ed in altre situazioni, è stato osservato un parziale interrimento delle briglie. in altri casi invece (n° 15, 16, 17), in cui gli apici idrografici delle conoidi sono localizzati in pieno centro abitato (sala consilina), gli alvei naturali purtroppo sono stati completamente ricoperti (tombati) creando così situazioni di alta possibilità di alluvionamento in caso di precipitazioni intense, come del resto evidenziato dalle testimonianze storiche raccolte. particolare attenzione è stata rivolta anche alla interazione tra gli alvei e la rete stradale (tab. 5 e fig. 6); in primo luogo sono stati cartografati i principali sottopassi evidenziando i punti in cui questi si presentavano palesemente sottodimensionati o parzialmente interrati (cfr. casella 15 in fig. 6). inoltre è stata evidenziata la presenza di alvei strada (conoidi n° 1, 3, 11, 19, 20, 23), cioè di strade che, avendo parzialmente o completamente sostituito l’alveo principale, possono fungere da recapito preferenziale di possibili fenomeni di esondazione e di trasporto solido. infine sono stati censiti tutti i punti in cui i lobi attivi delle conoidi interferiscono direttamente con strade trasversali o con case rurali sparse, in assenza di opere di protezione (conoidi n° 14,15, 16, 17, 19, 20, 22, 23, 25, 27) ed i punti in cui i gli alvei naturali e/o artificiali subiscono delle brusche variazioni di tracciato con la possibilità quindi di tracimazioni (conoidi n° 1, 10, 13, 23). per tutte le conoidi inoltre, sono state misurate le altezze degli argini nelle zone apicali ed è stata fatta una stima del volume massimo dei clasti visibili nell’alveo. infine, la prima colonna della tab. 5 sintetizza tutte le informazioni raccolte relativamente alle opere di sistemazione e difesa, raggruppandole in tre categorie in funzione del loro grado di mitigazione dei fenomeni alluvionali (inefficaci o assenti, parzialmente migliorative, migliorative) come proposto dall’autorità di bacino del po (sanna, 2003). tutte le informazioni su citate hanno contribuito alla definizione della pericolosità e del rischio come descritto nel paragrafo successivo. 6. pericolosità alluvionale della fascia pedemontana dei monti della maddalena per definire lo stato di pericolosità rispetto ai processi alluvionali della zona in studio è stato seguito e parzialmente modificato il metodo proposto recentemente dall’autorità di bacino del po per la valutazione della pericolosità sulle conoidi alluvionali, riportato in sanna (2003) esso prevede la valutazione di una serie di parametri, indicativi delle caratteristiche fisiografiche del bacino imbrifero, della quantità del materiale trasportato, dell’energia di trasporto, della ricorrenza dell’evento e della presenza e funzionalità di eventuali opere di sistemazione. questi parametri vengono integrati a coppie, in maniera progressiva, utilizzando una serie di matrici (tab. 6). la prima matrice considerata (tab. 6a) è quella relativa alla “massa solida (m)” definita dalla relazione esistente tra la superficie del bacino (divisa in tre classi: < 4, 4-20, > 20 km2) ed il rapporto percentuale tra la superficie della conoide (ac) e la superficie del bacino 12 tab. 5 sintesi dei dati di rilevamento. a = opere assenti; pm = opere parzialmente migliorative; m = opere migliorative; sc = strada comunale; a3 = autostrada sa-rc; ss = strada statale; ca = centro abitato; c = case sparse. synthesis of the data survey. a = absent; pm =; partly improving hydrological works; m = improving hydrological works; sc = city road; a3 = motorway sa-rc; ss = state road; ca = town or village; c = scattered houses. tipologie interazione dimensione volume conoidi opere con infraalveo medio idrauliche strutture (hxl) (mxm) clasti (m3) 1 a sc 1,5 2 0,024 2 a a3 1 1 0,002 3 pm c + a3 2,5 4 0,024 4 a ss19 1,5 1,5 0,002 5 pm 1,5 2,5 0,002 6 pm ss19 + a3 1 1 0,024 7 pm a3 1,5 4 0,072 8 m 6 5 0,096 9 pm ss19+a3+c 2 2 0,036 10 pm 1,5 1,5 0,002 11 pm sc 2 4 0,006 12 a sc + c 0,002 13 pm sc + ss19 2 4 0,006 14 pm ss19 4 6 0,002 15 a sc + ca tombato 0,036 16 a sc + ca tombato 0,040 17 a sc + ca tombato 0,192 18 a sc + ca tombato 0,096 19 a sc + c 1,5 3 0,006 20 a sc + c 1,5 2 0,024 21 a sc 2 4 0,006 22 a sc + c 3 4 0,008 23 a 1,5 2,5 0,006 24 pm sc + c tombato 0,048 25 m sc + c 2 3 0,012 26 m tombato 0,012 27 a sc + c tombato 0,014 n. santangelo, a. santo & p.i. faillace (ab). in questo modo vengono definite tre categorie di bacini che vanno da m1 a m3 (per i dati morfometrici si rimanda alle tab. 1, 2 e 3). la seconda matrice (tab. 6a) è relativa alla “tipologia del processo (t)” e viene ottenuta incrociando il parametro “massa solida” con “l’indice di melton” (cfr. tab. 3) che, come abbiamo già visto, consente di avere informazioni riguardo ai processi di trasporto prevalenti nelle conoidi in studio. in effetti nel metodo proposto viene considerata una suddivisione tra processi fluviali (mel < 0.25), misti (0.25 <mel <0.35) e debris flow (mel > 0,35) e vengono differenziate cinque diverse categorie (da t1 a t5). nel nostro caso, sulla base di quanto discusso nel paragrafo 2, in via cautelativa, si è preferito usare come valore discriminante tra le conoidi fluviali e quelle a debris flow prevalente, l’equazione proposta da d’agostino (1996). pertanto questa matrice è stata modificata ottenendo tre categorie (da t1 a t3). la terza matrice (tab. 6c) definisce il parametro “massa critica (mc)” e deriva dall’incrocio tra il parametro t ed il volume medio-massimo dei clasti (espresso in m3), rilevato sul campo (cfr. tab. 5), mentre la quarta matrice (tab. 6d) è relativa alla “intensità (i)“ e risulta dall’incrocio tra la massa critica e la pendenza della conoide (vengono considerate tre classi di pendenza: < 7°, 7-15°, > 15°; per i valori relativi ad ogni conoide si veda la tabella 3). la quinta matrice (tab. 6e) è quella della “pericolosità (p)” e si ottiene incrociando i dati relativi all’intensità con quelli legati al tempo di ritorno degli eventi che vengono suddivisi in tre classi: ricorrenti (r1, < 10 anni), occasionali (r2, tra 10 e 50 anni) ed eccezionali (r3, > 50 anni). in questo modo si definiscono le diverse classi di pericolosità. la sesta ed ultima matrice (tab. 6f) è quella della “pericolosità effettiva (h) ” che tiene conto della presenza di eventuali opere di difesa e del loro stato di conservazione. vengono considerate tre tipologie di opere (migliorative, parzialmente migliorative, inefficaci o assenti) e si arriva così a discriminare tra quattro classi di pericolosità: bassa, moderata, alta e molto alta (h1h4). la tabella 7 e la figura 7 riportano la sintesi di tutti questi passaggi. come si può osservare, su 27 conoidi alcune hanno un grado di pericolosità basso o moderato dovuto anche ai recenti lavori di sistemazione idraulica di alcuni corsi d’acqua (n° 8-25-26 in h1 e n° 3-5-7-9-10-11-13-14-24 in h2). molte altre invece (più della metà) presentano pericolosità alta (n° 2-4-6-1219-20-21-22-23-27 in h3) e cinque molto alta (n° 1-1516-17-18-19 in h4). il metodo applicato sembra rispondere abbastanza bene all’esigenza di valutare la pericolosità relativa tra le conoidi esaminate e per definire quindi le zone a maggior rischio e pianificare la selezione degli apparati su cui eseguire studi più dettagliati, finalizzati alla progettazione di eventuali interventi di sistemazione. rimane il fatto però che questo metodo non consente di effettuare l’individuazione di zone a diverso grado di pericolosità all’interno di una singola conoide. ciò può essere trascurato quando le conoidi in oggetto sono di limitate dimensioni, ma può diventare un problema significativo, anche in termini amministrativi e di pianificazione, quando si ha a che fare con apparati grandi su cui insistono centri abitati o importanti infrastrutture. 13 tab. 6 matrici utilizzate per la valutazione della pericolosità alluvionale. da sanna (2003), parzialmente modificate. matrices used for the evaluation of the alluvial hazard. from sanna (2003), partly modified. valutazione della pericolosità alluvionale ... 14 n. santangelo, a. santo & p.i. faillace fi g. 7 c ar ta d el la p er ic ol os ità d el le c on oi d i d el v al lo d i d ia no . h 1h 2h 3h 4 = li ve lli d i p er ic ol os ità (b as sa , m od er at a, a lta , m ol to a lta ); r = s et to ri a ris ch io m ol to e le va to . h az ar d m ap o f t he a llu vi al fa ns o f t he v al lo d i d ia no . h 1h 2h 3h 4 = c la ss es o f h az ar d (l ow , m od er at e, h ig h, v er y hi gh ). r = s ec to rs o f t he fa ns w ith v er y hi gh r is k co nd iti on s. per questo motivo sono stati ricercati altri parametri che consentissero di fare delle differenziazioni del grado di pericolosità all’interno di ogni singola conoide. sono stati allora considerati i profili topografici longitudinali delle conoidi studiate (fig. 8) costruiti considerando la direzione della bisettrice del cono stesso. e’ stato osservato che 15 conoidi su 27 presentano almeno una significativa rottura di pendenza che consente di individuare un settore apicale, più acclive, ed un settore distale caratterizzato da pendenze più blande. considerando che gli eventuali processi di trasporto solido più intensi (maggiore granulometria dei clasti) hanno minore probabilità di verificarsi nelle porzioni più distali delle conoidi, si è ritenuto opportuno ritoccare la classe di pericolosità precedentemente definita, utilizzando come elemento discriminante tra zone apicali e zone distali, la rottura di pendenza più significativa presente sulle conoidi in studio. in questo modo le parti distali dei conoidi n.° 1516-17-18 sono state declassate da una pericolosità h4 ad una h3 e quelle delle conoidi n.° 19-20-21-22-23 da h3 a h2. (fig. 7). 15valutazione della pericolosità alluvionale ... 2 la pendenza delle conoidi è stata calcolata come rapporto tra il dislivello e la distanza lineare; poiché essa non si mantiene costante lungo tutte le direttrici del cono, si è preferito calcolare diverse pendenze lungo due o più raggi del cono e ricavare la media dei valori ottenuti. tab. 7 risultati relativi alla valutazione della pericolosità per le 27 conoidi attive del vallo di diano. results of the evaluation of the alluvial hazard for the 27 active fans of the vallo di diano. conoidi massa tipologia del massa intensità pericolosità pericolosità pericolosità solida processo critica intrinseca opere 1 m2 t3 mc2 i2 p3 h4 molto alta 2 m2 t3 mc1 i1 p2 h3 alta 3 m2 t3 mc2 i1 p2 h2 moderata 4 m1 t2 mc1 i1 p2 h3 alta 5 m3 t2 mc1 i1 p2 h2 moderata 6 m1 t2 mc2 i2 p3 h3 alta 7 m1 t2 mc2 i1 p2 h2 moderata 8 m3 t2 mc2 i1 p2 h1 bassa 9 m3 t3 mc2 i1 p2 h2 moderata 10 m2 t3 mc1 i1 p2 h2 moderata 11 m3 t3 mc1 i1 p2 h2 moderata 12 m2 t3 mc1 i1 p2 h3 alta 13 m2 t3 mc1 i1 p2 h2 moderata 14 m3 t3 mc1 i1 p2 h2 moderata 15 m3 t3 mc2 i2 p3 h4 molto alta 16 m2 t3 mc2 i2 p3 h4 molto alta 17 m3 t3 mc2 i2 p3 h4 molto alta 18 m2 t3 mc2 i2 p3 h4 molto alta 19 m3 t3 mc1 i1 p2 h3 alta 20 m2 t3 mc2 i1 p2 h3 alta 21 m3 t3 mc1 i1 p2 h3 alta 22 m3 t3 mc1 i1 p2 h3 alta 23 m3 t3 mc1 i1 p2 h3 alta 24 m2 t3 mc2 i1 p2 h2 moderata 25 m3 t2 mc2 i1 p2 h1 bassa 26 m3 t3 mc2 i1 p2 h1 bassa 27 m3 t3 mc2 i1 p2 h3 alta per quanto riguarda le conoidi n° 8-25-26, nonostante esse siano state storicamente più volte interessate da eventi alluvionali, il basso grado di pericolosità ottenuto si spiega considerando le numerose opere idrauliche realizzate in alveo nell’ultimo decennio. 7. considerazioni conclusive lo studio condotto sulla pericolosità delle 27 conoidi alluvionali attive del vallo di diano ha voluto rappresentare un test metodologico che potrebbe essere applicato ed eventualmente modificato, in numerose altri settori pedemontani appenninici, per i quali non esistono ancora studi dettagliati. la metodologia adottata per il vallo, che deriva da quella proposta dall’autorità di bacino del po (sanna, 2003), ha dato buoni risultati e ripartito le 27 conoidi in almeno quattro diverse classi di pericolosità. per quanto riguarda le situazioni di maggior rischio non si è entrati nel merito di una precisa differenziazione delle classi (r1r4) in quanto questa non può prescindere dalla redazione di una carta del danno atteso che esula dalle competenze degli autori. sono state tuttavia indicate come zone a maggior livello di rischio (fig. 7) i settori apicali delle conoidi n° 15-16-1718 che interagiscono con il centro abitato di sala consilina ed i punti critici in cui possibili esondazioni potrebbero raggiungere la rete autostradale (conoidi n° 3-6-7-9). rimangono tuttavia numerosi altri settori ove conoidi a pericolosità h2 e h3 interagiscono con centri abitati, case sparse e strade provinciali e comunali. ad ogni modo le reali condizioni di rischio andrebbero verificate a scala di maggiore dettaglio (almeno 1:2000) con studi stratigrafici, geomorfologici ed idraulici che tengano conto soprattutto delle variazioni topografiche e morfologiche della conoide e, nei centri abitati, delle interazioni tra eventuali flussi idrici e assetto urbanistico locale, come ad esempio la presenza di alvei strada o di grandi strutture che possono modificare notevolmente la direzione di canalizzazione dei fenomeni di trasporto solido. bibliografia ascione a., cinque a., santangelo n. & tozzi m. (1992) il bacino del vallo di diano e la tettonica trascorrente plio-quaternaria: nuovi vincoli cronologici e cinematica studi geol. camerti, vol. spec. (1992/1), 201-208 blissenbach (1954) geology of alluvial fans in semiarid regions geological society of america bullettin, 65, 175-190. budetta p., santangelo n., santo a. (2000) interazioni tra processi alluvionali ed insediamenti abitativi in epoca storica: il caso della certosa di padula – convegno geoben 2000, torino 7-9 giugno. bull w.b.(1968) alluvial fans – journal of geology, 16, 101-106. d’aagostino v. (1996) analisi quantitativa e qualitativa del trasporto solido torrentizio nei bacini montani del trentino orientale estratto da: associazione italiana di ingegneria agraria 1° sezione, convegno di studio “i problemi dei grandi comprensori irrigui”, novara 6 – 7 giugno 1996. de scally fes a. and owens ian f. (2004) morphometric controls and geomorphic responses on fans in the southern alps, new zealand earth surface processes and landforms, 311-322 eckis r. (1928) alluvial fans in the cucamonga district, southern california – journal of geology, 36, 111141. genio civile (1858) busta 90, n° 91, archivio di stato di salerno giandotti m. (1934) previsione delle piene e delle magre dei corsi d’acqua memorie e studi idrografici, pubbl. 2 del servizio idrografico italiano, vol viii, 107. harvey a.m. (1988) controls of alluvial fan developments: the alluvial fans of the sierra de carrascoy, murcia, spain – catena supplement, 13, 123-137. jackson l.e.j.r., kostaschuk r.a, mac donald g.m. (1987) identification of debris flow hazard on alluvial fans in the canadian rocky mountains – geol. soc. of america, rew. in eng. geol., 7, 115-124. kostaschuk r.a., mac donald g.m., putman p.e.(1986) depositional processesand alluvial fan-drainage 16 fig. 8 alcuni esempi di profili topografici delle conoidi studiate, con indicazione delle principali rotture di pendenza. some exemplas of topographic profiles of the studied alluvial fan with indication of the main nick points. n. santangelo, a. santo & p.i. faillace basin morphometric relationship near banff, alberta, canada earth surface processes and landforms, 11, 471484. lippmann provansal m. (1987) l’apennin campanien meridional. etude geomorphologique. these de doctorat, universite d’aix-marseille, aix-en-provence, tome 1. marchi l.,pasuto a., tecca p.r. (1993) flow processes on alluvial fans in the eastern italian alps – z. geomorph. n.f., 4, 447-458. marchi l., tecca p.r. (1995) alluvial fans of eastern italian alps: morphometry and depositional processes geodinamica acta, 8 (1), pp. 20-27. melton m. a (1965) the geomorphic and paleoclimatic significance of alluvial deposits in southern arizona the journal of geology, 73, pp.1-39. national research council (nrc) (1996) alluvial fan flooding – national academy press, pp.1-131. pasuto a., marchi l., tecca p.r. (1992) tipologia del trasporto solido torrentizio su conoidi alluvionali nell’alto bacino dell’avisio (dolomiti) – boll. soc. geol. it., 111, pp.41-51. pesce c. (1889) il vallo di diano e la certosa di padula archivio di stato di salerno. ryder j. m. (1971a) some aspects of morphometry of paraglacial alluvial fans in south-central british columbia canadian journal of earth sciences, 8, pp. 1252-1264. sanna s. (2003) sistemazioni idraulico–forestali nella difesa del suolo pp. 331, dario flaccovio ed. santangelo n. (1991) evoluzione stratigrafica, geomorfologica e neotettonica di alcuni bacini lacustri del confine campano lucano (italia meridionale) tesi di dottorato di ricerca in ‘geologia del sedimentario’, iii ciclo, università degli studi di napoli “federico ii” dipartimento di scienzadella terra. 17 ms. ricevuto il 17 novembre 2005 testo definitivo ricevuto il 21 marzo 2006 ms. received:november 17, 2005 final text received:march 21, 2006 valutazione della pericolosità alluvionale ... imp.biserni& shape reconstruction of the pleistocene/holocene unconformity in the grosseto alluvial plain (tuscany, italy) giacomo biserni1, henk j.a. berendsen2 & fabio sandrelli1 1earth science department, faculty of geology, university of siena, via laterina 8, 53100 siena, italy e-mail: biserni@unisi.it; sandrelli@unisi.it; 2department of physical geography, utrecht university, heidelberglaan 2, 3508 tc utrecht, the netherlands abstract: biserni g., berendsen j.a.h. and sandrelli f., shape reconstruction of the pleistocene/holocene unconformity in the grosseto alluvial plain (tuscany, italy) (it issn 0394-3356, 2004) one hundred two boreholes were drilled in grosseto alluvial plain (tuscany, italy). coring evidence shows a sharp lithological change that is interpreted as a pleistocene/holocene unconformity. this suggests the presence of a paleovalley that was eroded by the ombrone river during the last glacial interval. radiocarbon samples and surface’s geometry of lithological changes corroborate this explanation. riassunto : biserni g., berendsen j.a.h. and sandrelli f., ricostruzione dell’andamento della unconformity pleistocenica-olocenica all’interno della pianura alluvionale grossetana (toscana, italia) (it issn 0394-3356, 2004) la pianura di grosseto, all’interno della quale scorrono il fiume bruna e ombrone, si estende per circa 370 km2 ed è delimitata dai rilievi di castiglione della pescaia a nord-est, dalle colline di grosseto ad est e dai monti dell’uccellina a sud (fig.1). bravetti & pranzini (1987), innocenti & pranzini (1993), stea (1995), bellotti et al., (1999), bellotti et al., (2001) e carboni et al., (2002) ricostruiscono la lenta evoluzione di questa pianura durante il quaternario. la caduta del livello marino, venutosi a verificare durante l’ultimo glaciale (stadio 5e), determinò un abbassamento del livello di base di circa 120 m. i fiumi ombrone e bruna scavarono due paleovalli nelle precedenti alluvioni presso i lati della pianura attuale, lasciando in rilievo la parte mediana. la successiva trasgressione versiliana trasformò le due valli in insenature marine in seguito colmate, con velocità diverse dai due fiumi. in questo lavoro, mediante una serie (circa 100) di microperforazioni manuali e alcune perforazioni profonde, viene ricostruito l’andamento di una unconformity all’interno della pianura alluvionale grossetana, interpretata, grazie a datazioni radiometriche, come pleistocenica-olocenica. la sua forma suggerisce la presenza di una paleovalle erosa dal fiume ombrone durante l’ultima glaciazione. keywords : pleistocene/holocene unconformity; paleovalley, radiocarbon dating. parole chiave : unconformity pleistocenica-olocenica,; paleovalle, datazioni radiometriche. il quaternario italian journal of quaternary sciences 17(2/2), 2004, 443-451 introduction the grosseto plain is delimited by the castiglione della pescaia hills in the northwest, grosseto hills in the east, and uccellina mounts in the south (fig. 1). the sedimentary evolution of the grosseto plain during the quaternary was previously described based on stratigraphies derived from wells drilled randomly by farmers and with subsurface data collected for a hydrogeologic study (bravetti & pranzini, 1987; bellotti et al., 1999). during the late pleistocene, fluvial and aeolian sediments were deposited, which now crop out in low terraces along the borders of the alluvial plain (mazzanti, 1983; bravetti & pranzini, 1987). during the last glacial interval, when sea level dropped approximately 100 m below the present level, the ombrone and bruna rivers presumably cut two valleys into pleistocene deposits, on opposite sides of the present alluvial plain. the valleys became sedimentary areas for marine and river deposits during the holocene transgression (versilian transgression). the southern valley was filled more rapidly because the ombrone river carries more clastic material than the bruna river. so far, the thickness of the holocene sediments has not been determined in a reliable way, and evidence for the existence of these paleovalleys was not presented so far. data from stea (1995) and bellotti et al. (2001, 2004) suggest a holocene thickness of up to 50 m. however, the dates of bellotti et al. (2001, 2004) do not agree with the sea level curve for the tyrrhenian sea (biserni et al., submitted). if the dates of bellotti et al. (2001) are plotted on the tyrrhenian sea level curve (biserni, 2004), it can be seen that their data deviate considerably from the curve, suggesting that their data are not coherent with the tyrrhenian environmental evolution during the holocene. cause of that these data cannot be used to calculate reliable sedimentation rates. a possible reason for this deviation is that the borehole of bellotti et al. (2001) was drilled in the channel belt of the river. this inevitably leads to an overestimation of sedimentation rates, because channels incise into the pleistocene substratum. berendsen (1982), törnqvist (1993) and makaske (1998) suggested to collect samples within the alluvial plain to reliably measure sedimentation rates. 444 g. biserni, h.j.a. berendsen & f. sandrelli the purpose of this study was to approximately determine the thickness of the holocene sediments and to reconstruct the shape of the late-pleistocene ombrone paleovalley that was incised during sea level low stand. methods we performed a geomorphological and lithostratigraphical study and radiocarbon dated organic deposits in the ombrone plain. this has been done by drilling a series of boreholes and by analyzing deep mechanical wells drilled by farmers. three radiocarbon samples were obtained for time control. coring and alluvial architecture the lithological information was obtained by coring, as there were no outcrops available. boreholes were drilled in a ~ 6 km long section in a nw-se direction. whenever possible, boreholes were drilled at 50 m intervals. the cores reached an average depth of 8-9 m, the deepest one is 15 m and the shallowest one is 4 m. the transect is situated approximately 6 km from the coast and crosses the ombrone river in punta dello spolverino (fig. 1). the cores reached an average depth of 8-9 m. we used a gouge and piston corer to study the stratigraphy and to collect samples for accelerator mass spectometry (ams) radiocarbon dating. all sediment cores were described in the field at 10 cm intervals with regard to texture, organic content, color, median grain size of sand (using a sand ruler), gravel content, oxydized iron content, calcium carbonate content (using a 5 % hcl solution), occurrence of groundwater, shells and other characteristics, following berendsen & stouthamer (2001). the lithologic units were subsequently grouped into ‘lithogenic units’ of ‘facies units’, an approach that closely follows berendsen (1982) and miall (1985). the structure of facies units in a delta complex is generally called alluvial architecture. each unit is characterized by its grain size, composition, internal sequence and external geometry. loss on ignition (loi) analyses were carried out on samples from borehole 58. three typical architectural elements occurring in a fig. 1 geological sketch map of the ombrone river basin (after geological map of italy, simplified). carta geologica schematica della parte terminale del bacino del fiume ombrone (carta geologica dell’italia, semplificata). 445shape reconstruction of the ... fi g. 2 a li th ol og y of t ra ns ec t a -a r ic os tr uz io ne li to lo gi ca d el t ra ns et to a -a fi g. 2 b a rc hi te ct ur al e le m en ts o f t ra ns ec t a -a e le m en ti ar ch ite tt ur al i d el t ra ns et to a -a fi gu re 2 c ro ss s ec tio n th ro ug h a -a i n th e o m b ro ne r iv er . t he li th ol og y is in te rp re te d in t er m s of a rc hi te ct ur al e le m en ts . f or lo ca tio n se e fi g. 1 s ez io ne li to lo gi ca d el b ac in o d el f iu m e o m b ro ne e in te rp re ta zi on e ge ol og ic a in t er m in i d i e le m en ti d el l’a rc hi te tt ur a flu vi al e 446 meandering alluvial plain were recognized: • small natural levee deposits, consisting of sandy clay. the wedge-shaped natural levees occur near the ombrone river. • channel deposits, consisting of sand, deposited by the ombrone river. the channel deposits are ribbonshaped sandbodies. • floodplain deposits, consisting of gray-brown siltyclay that overlies dark gray blue lacustric clay. thin layers of organic material (peat) occur intercalated in the floodbasin deposits. the alluvial architecture of the ombrone area is shown in figure 2. two organic samples were selected for accelerator mass spectrometry (ams) radiocarbon dating using terrestrial macrofossils. laser diffraction analysis soil samples were collected randomly all over the alluvial plain, between 50 and 80 cm below the surface. in the low lying part of the alluvial plain, the upper 4050 cm are thought to be a result of reclamations (la bonifica grossetana, 1956), hence no samples were taken from the upper 50 cm. all samples were taken using an edelman hand auger. grain size of these samples was studied using laser diffraction analysis. results of the laser diffraction analyses are shown in a soil map of the alluvial plain presented in figure 4. geomorphological-geological mapping in mapping the ombrone fluvial system, borehole descriptions were interpreted following the approach of berendsen (1982), miall (1985) and berendsen & stouthamer (2001). the main features of the ombrone river and the grosseto alluvial plain have been analyzed from a morphological and sedimentological viewpoint, using maps, aerial photographs and field evidence. four morphological elements are shown in figure 3: ➢ a beach-ridge delta plain parallel to the coastline, characterized by a wide dune-belt close to the present river mouth, that becomes narrow near castiglione della pescaia, where high foredunes occur (mori, 1935; bird & jones, 1988); ➢ a wide, fairly f lat and low-lying floodplain located behind the beach-ridge. the floodplain is higher near the channel belt, reaching an elevation of 3-4 m above sealevel; ➢ an approximately 1 km wide channel belt of the ombrone river. ➢ a higher elevated area can be distinguished in the middle-eastern part of the alluvial plain. a scarp of 3-4 m occurs near to “il poggiale”, “le gorarelle” and “la rugginosa”, sw, s and ene of grosseto. elevation increases from 5-6 meters to 15-19 m close to the istia hills. results lithostratigraphy borehole ombrone 58 (see fig. 2), can be regarded as representative for the ombrone alluvial plain, and will be described here in more detail. the lithology has been studied through accurate field and laboratory inspection. the core was divided in 8 lithozones (fig. 5) reflecting varying environmental conditions. the sediments of lithozone a indicate a sporadic high-energy environment in a generally low energy setting, dominated by clay sedimentation. the presence of sand layers and broken and complete marine shells (like cerastoderma sp., hydrobia sp., tellinea pulchella) in a clayey matrix suggests marine flooding. from this layer, at a depth of 8.76 m below the surface, a sample was taken for radiocarbon analyses, which yielded a radiocarbon age of 7724-7651 cal yr bp. the smaller grain size of the overlying lithozone (b) indicates a general decrease of energy. the fine grain size and the presence of a thin peaty horizon in lithozone c indicates a low-energy environment no longer affected by floods and storms. lithozones d and e are characterized by slightly organic gray-blue clay; the organic content in lithozone e decreases upward. lithozones (f-h) are characterized by lithological change, from blue clay to gray-brown silty clay, to graybrown clayey silt characterized by an upwards decreasing organic content and a gradual increase of oxidation coatings. those characteristics indicate an alluvial environment connected with the ombrone river. a change of grain size, the occurrence of reworked fossils g. biserni, h.j.a. berendsen & f. sandrelli fig. 3 morphological and sedimentological sketch map of the grosseto alluvial plain carta morfologica e sedimentologica della pianura alluvionale grossetana 447shape reconstruction of the ... fig. 4 soil map of the ombrone alluvial plain (after sevink et al., 1982; modified) carta dei suoli della pianura alluvionale del fiume ombrone (sevink et al., 1982; modificata) 448 and the presence of glomus indicates a supply of sediments from the river. the uppermost part of the lithological log is affected by pedogenesis and agriculture. evidence for a stratigraphic unconformity approximately 15 new wells mechanically-drilled were accurately examined, in addition to one borehole obtained by bellotti et al. (2001). the stratigraphies of the wells in the lower part of the alluvial plain (table 1) are characterized by an alternation of aquatic gray-blue g. biserni, h.j.a. berendsen & f. sandrelli fig. 5 lithological log of borehole 58 (depth in cm below ground level) ricostruzione litologica dei sedimenti rinvenuti dal borehole 58 (la profondità è espressa in cm) clay and dark-blue or gray clay with a varying microand macrofossil content in the upper 11-12 m (biserni et al., 2001), very similar to the sediments of borehole b-58 described above. a sudden and sharp change of sedimentary facies from gray-blue clay and dark-blue or gray clay to brown-yellow-beige clay-silt characterized by oxydation coatings occurs in the ponte nuovo and casotto dei pescatori wells at a depth of approximately 9-10 m and 11-12 m below the surface respectively. 449shape reconstruction of the ... wells drilled in the elevated part of the alluvial plain (e.g. fattoria la principina, rugginosa, via canada, via madagascar and via oberdan, see table 1) show the same brown-yellow-beige clay-silt from the surface on downwards. samples collected from this depth for paleobotanical and paleontological analyses are extremely poor in macrofossils, and pollen grains, if present, are not well preserved (e.g. in samples from a depth of 4.0, 4.5, 5.0, 5.5 ,7.0 and 7.5 m below the surface in well casotto dei pescatori). these sediments seem to have formed under subaerial conditions. the same lithological and paleobotanical transition occurs at a depth of approximately 16-17 m below the surface in boreholes p. casole and p. isonzo that are located close to the river. in figure 6 the subsurface elevation of the transition is plotted in section 1,2 and 3. the geometry of the transition suggests the presence of a paleovalley below the present ombrone river, that may have formed during the last sealevel lowstand (bravetti & pranzini, 1987). new ams data, here presented, give a new contribution to reconstruct the development of this area during the transition between pleistocene and holocene. a sample for ams radiocarbon dating was collected from well casotto dei pescatori at a depth of 22 m below the surface. this sample yielded an age of 36400 ± 2800 yr bp. in borehole 58 a radiocarbon sample from a depth of 8.76 m was dated at 6860 +/50 yr bp. these ams date, lithological observation and the surface’s geometry of lithological changes described above and reconstructed in fig. 6 point out that the lithological transition may represent an unconformity, which represents the pleistocene/holocene boundary. 450 fig. 6 schematic sections through the grosseto alluvial plain sezioni schematiche attraverso la pianura alluvionale grossetana g. biserni, h.j.a. berendsen & f. sandrelli conclusions the higher part of the grosseto alluvial plain is lithologically and morphologically different from the low alluvial plain. it is delimited by a scarp of 3-4 m. the higher part is interpreted as a terrace, originally separating two palaeovalleys incised during the last glacial (mis 2-4) (mazzanti, 1983; bravetti & pranzini, 1987; bellotti et al., 2001). based on lithological and micropaleontological similarities, the surface of the terrace is correlated with the sediments that occur in boreholes below the sharp lithological change. therefore the lithological transition in the boreholes is interpreted to respresent an unconformity at the pleistocene/ holocene transition. radiocarbon ages corroborate this interpretation. the paleovalley most likely formed by incision during the lowstand of the tyrrhenian sea. acknowledgments we thak prof. maria pareschi and “acquedotto del fiora s.p.a.”. references bellotti p., 2000 il modello morfo-sedimentario dei maggiori delta tirrenici italiani. boll. soc. geol. it., 119, 777-792. bellotti p., belluomini g., bergamin l., carboni m.g., di bella l., improta s., letuov p.p., mandra l., potyomkina t.g., valeri p., and vesica p., 2001 nuovi dati cronostratigrafici sul sottosuolo della piana deltizia del fiume ombrone (toscana meridionale): studi costieri, v. 4, p. 33-42. bellotti p., caputo c., davoli l. evangelista, garzanti e., pugliese f. and valeri p., 2004 morpho-sedimentary characteristics and holocene evolution of the emergent part of the ombrone river delta (southern tuscany), geomorphology 61 (2004), 71-90. bellotti p., caputo c., davoli l., evangelista s., and valeri p., 1999 lineamenti morfologici e sedimentologici della piana deltizia del fiume ombrone (toscana meridionale): bollettino della societa’ geologica italiana, v. 118, p. 141-147, 2 ff., 1 tav. berendsen, h. j.a., 1982, de genese van het landschap in het zuiden van de province utrecht, een fysisch-geografische studie. ph.d. thesis utrechtse geografische studies 10, p. 256. berendsen h. j.a., and stouthamer e., 2001 paleogeographic development of the rhinemeuse delta, the netherlands. assen: van gorcum, p. 268. bird e.c.f., and jones d.j.b., 1988 the origin of foredunes on the coast of victoria, australia: journal of coastal research, v. 4, p. 181-192. biserni g., 2003 ricostruzione dell’evoluzione stratigrafica, paleogeografica e paleoambientale olocenica della pianura alluvionale del fiume ombrone (toscana meridionale, italia); tesi di dottorato, siena biserni g., bambini a., and foresi l. m., 2001 analisi di alcuni sedimenti tardo-quaternari della pianura di grosseto: geosed 2001, 2-7 october, potenza, italy. biserni g., and van geel b., in press reconstruction of holocene vegetation and sedimentation history of the ombrone alluvial plain (south tuscany, italy). bravetti l., and pranzini g., 1987 l’evoluzione quaternaria della pianura di grosseto (toscana): prima interpretazione dei dati di sottosuolo: geografia fisica e dinamica quaternaria, v. 10, p. 85-92. carboni m.g., bergamin l., di bella l., iamundo f., and puglise n., 2002 paleoecological evidences from foraminifers and ostracods on late quaternary sea-level changes in the ombrone river plain (central tyrrhenian coast, italy): geobios, memoire speciali, v. 24, p. 40-50. innocenti l., and pranzini e., 1993 geomorphological evolution and sedimentology of the ombrone river delta, italy: journal of coastal research, v. 9, p. 481-493. la bonifica grossetana, 1956 consorzio di bonifica di grosseto. volume speciale. makaske b., 1998 anastomosing rivers. forms. processes and sediments. ph.d thesis, utrecht university. mazzanti r., 1983 il punto sul quaternario della fascia costiera e dell’ arcipelago di toscana: bollettino della societa’ geologica italiana, v. 102, p. 419556. miall a.d., 1985 architectural-elements analysis: a new method of facies analysis applied to fluvial deposits: earth-science reviews, p. 261-308. miall a.d., 1996 the geology of fluvial deposits. berlin: springer verlag, 582 p. mori a., 1935 l’ evoluzione della costa grossetana dal pliocene ai giorni nostri. annuario 1932-1935 del r. liceo-ginnasio di grosseto: la maremma, grosseto, p. 21. sevink j., beemster j., e van stiphout t., 1982 soil map of the grosseto area. university of amsterdam. subfaculty of physical geography e soil science. amsterdam. the netherles. stea b., 1995 il forte di san rocco: l’ambiente geologico, in il forte di san rocco, archivio di stato di grosseto, pp. 111-127. törnqvist t.e., 1993 fluvial sedimentary geology and chronology of the holocene rhine-meuse delta, the netherlands. ph.d. thesis. university of utrecht, the netherlands. 451 ms. ricevuto il 1° settembre 2004 testo definitivo ricevuto il 15 dicembre 2004 ms. received: september 1, 2004 final text received: dicember 15, 2004 shape reconstruction of the ... sess 0_retro e indice edi.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 the straight–tusked elephants from neumark nord 1: the state of art federica marano1 & maria rita palombo1,2 1 dipartimento di scienze della terra la sapienza università di roma, roma 2 cnr, istituto di geologia ambientale e geoingegneria, roma corresponding author: f. marano <federica.marano86@gmail.com> abstract: marano f. & palombo m.r., the straight – tusked elephants from neumark nord: the state of art. (it issn 0394-3356, 2011) the german sites bearing straight-tusked elephant remains cover a period from 400 ka (mis 11) to the eemian age (mis 5e). the material excavated since 1980, in the lacustrine sediments of neumark nord (eastern germany), is one of the most outstanding samples of straight-tusked elephants in europe. the neumark-nord material enhances our knowledge of the body size, sexual dimorphism, ontogenetic growth and morphological variability of palaeoloxodon antiquus. riassunto: marano f. & palombo m.r., gli “elefanti antichi” di neumark nord: lo stato dell’arte. (it issn 0394-3356, 2011) i siti tedeschi in cui sono stati ritrovati resti di” elefante antico” coprono l’intervallo temporale da 400 ka (mis 7) fino all’interglaciale eemiano (mis 5e). il materiale recuperato dal 1980 nei depositi lacustri di neumark nord1 (germania orientale) è tra i più affascinanti e rilevanti di europa ed ha significativamente contribuito ad ampliare le nostre conoscenze sulla taglia, il dimorfismo sessuale, la crescita ontogenetica e la variabilità morfologica della specie palaeoloxodon antiquus. key words: palaeoloxodon antiquus, neumark nord 1, mis7?, mis5e?, germany parole chiave: palaeoloxodon antiquus, neumark nord 1, mis7?, mis5e?, germania the german sites bearing straight-tusked elephant remains cover a period from about 400 ka (mis 11) to about 110 ka (eemian, mis 5e). the fossil records mainly consist of isolated remains, while more or less complete skeletons are reported from a few localities (fig. 1). among these, the site at neumark nord 1 (nn1) is of outstanding interest because of the number of bones and the excellent preservation of elephant remains retrieved since the ‘80s from the lacustrine sediments filling this small endorheic basin. the age of the fossiliferous sequence is still a matter of debate. some authors claimed it could be dated to the middle pleistocene (mis 7), based on pollen data, as well as on the presence of the rodent apodemus maastrichtiensis (see seifert-eulen, 2010; heinrich, 2010). others consider them to have been deposited during the eemian interglacial (mis 5e) (kolfschoten, 2000, koenigswald, 2007), as suggestest by recent esr dating (schüler, 2010). the rich paleontological sample from nn 1 consists of about two hundred species of plants as well as invertebrates, insects, and a diversified vertebrate fauna, including palaeoloxodon antiquus, three species of rhinoceros, fallow deer, red deer, aurochs as well as some carnivores such as wolf, lion and spotted hyaena (mania, 2010). 1. palaeoloxodon antiquus from neumark nord 1 the straight-tusked elephants from neumark-nord 1 provide outstanding information on the morphology and biometry of european p. antiquus, and 147 149 1-legringen, 2-gröbern, 3-grabschutz, 4-rabutz, 5-neumark nord, 6-taubach weimar, 7-burgtonna, 8-stuttgartuntertürkheim, 9-binsfeld, 10-kiesächer, 11-crumstadt, 12bilzingslebien, 13-schöningen, 14-bad cannstatt, 15-memleben, 16-mauer, 17karlich seeufer, 18-schönebeck, 19-süssenborn, fig. 1, localization of the german sites where palaeoloxodon antiquus was retrieved. localizzazione dei siti tedeschi in cui sono stati ritrovati 148 successive filling episodes during an interglacial phase. most of remains were found in the middle “gyttja”, 6.1 and 6.2 layers, both deposited during a lake level reduction (see mania, 2010). the minimum number of individuals found at nn 1, inferred on the basis of the location of the finding, the size of the remains, the degree of epiphysis fusion, as well as the progression in tooth eruption, fig. 2, comparison of the shoulder height, as a function of known age, calculated for female and male elephants from neumark-nord (big points), the specimens from gröbern (large squares) and the specimen from crumstadt (star), and the shoulder height of african elephants from the amboseli national park (kenya) (small squares) and addo elephant national park (south africa) (small points). confronto tra le altezze alla spalla in funzione dell’età calcolate per gli esemplari maschili e femminili di neumark nord1 (punti grandi), quelli di gröbern (quadrati grandi) e di crumstadt (asterisco) e le altezze degli esemplari africani del national park (kenya)(quadrati piccoli) e addo elephant national park (sud africa) (punti piccoli). f. marano & m.r. palombo enhance our knowledge of the body size, sexual dimorphism, ontogenetic growth and morphological variability of this species (palombo & ferretti, 2010; palombo et al., 2010). more than 1500 elephant remains (among which more than 90% have been identified) have been retrieved from 6 fossil-bearing layers within the lower, middle and upper “gyttja”, which represent 149 ms. received: testo ricevuto il should be nearly 70. nevertheless, this number might be overestimated, because of the difficulty in assessing largely incomplete bones, seriously damaged by excavators (palombo et al., 2010). the age of 35 individuals, and the sex of only 26 has been confidently determined. in the examined sample, adult individuals older than twenty five (94.3%) and males (61.5%), definitely prevail. the maximum body mass should range from about 6000 kg in relatively young (24–28 years old) individuals to about 11000 kg in adult males (49 years old), and from about 4500 kg in young individuals (24–28 years old) to about 6000 in adult females. the size of straight-tusked elephants from nn 1 is consistent with that of the adult elephants found at gröbern (sachsen-anhalt, germany) and of the young specimen from crumstadt (hessen, germany) (fig. 1). at gröbern, two nearly complete skeletons belonging to a male (gröbern i) and a female (gröbern ii), both 35-40 years old, have been retrieved from lacustrine sediments dated to the eemian (kroll, 1991; göhlich, 2000; weber, 2000). the adult male from gröbern is slightly larger than the males from nn 1. indeed its size is similar to that of the nn 1 specimens, e 2.1.96 (2007:25.279) and e 23 (2007:25.285), which are each about 47 years old. conversely, the size of the female is close to the size of a female (specimen e8, 2007:55) of about the same age found at nn 1 (marano & palombo, in press). the juvenile female (20 years old) specimen from crumstadt (hessen, germany) (kroll, 1991), is smaller than all of the females found at nn1. however, none of the complete skeletons from nn1 is comparable in age to the crumstadt specimen. the youngest, a male six years older than the female from crumstadt, is definitely larger, stressing the sexual dimorphism that characterizes straighttusked elephants (fig. 2). all in all, the elephants from neumark-nord 1 share most of the basic traits with the other german straight tusked elephants, which reveal a comparable size and a remarkable dimensional gap between the sexes. moreover, the analyzed data confirm the considerable morphological variability of this species. references göhlich u.b. (2000) on a pelvis of straight-tusked elephant elephas antiquus (proboscidea, mammalia) from binsfeld near speyer (rhineland-palatine, germany). paläntologische zeitschrift ,74, pp. 205–214. heinrich w.d. (2010) klein, aber oho: die zwergwaldmaus apodemus maastrichtiensis. veröffentlichungen des landesamtes für denkmalplege und archäologie, pp. 79-82. koenigswald w. von (2007) mammalian faunas from the interglacial periods in central europe and their stratigraphie correlationthe climate of past interglacials. in sirocko f. (ed.) the climate of past interglacials, developments in quaternary sciences, 7, pp. 445–454. kolfschoten t. van (2000) the eemian mammal fauna of central europe. geologie en mijnbouw, 79 (2/3), pp. 269–281. kroll, w. (1991) der waldelefant von crumstadt. ein beitrag zur osteologie des waldelefanten elephas (palaeoloxodon) antiquus falc. and cautl. (1847). inaug. diss., tierärztl. kak., univ. münchen. mania d. (1999) 125 000 jahre klimaund umweltentwicklung im mittleren elbe-saale-gebiet. hercynia 32, pp. 1–97. mania d. (2010) neumark nord – ein interglaziales ökosystem des mittelpaläolithischen menschen. veröffentlichungen des landesamtes für denkmalplege und archäologie, 6 2, 527 pp. marano f. & palombo m.r. (in press) a pathologic straight-tusked elephant female from neumark nord (germany). il quaternario, palombo m.r., albayrak e. & marano f. (2010) the straight-tusked elephants from neumark nord, a glance to a lost world. kataloge zur dauerausstellung im landesmuseum für vorgeschichte halle: elefantenreicheeine fossilwelt in europa. palombo m.r. & ferretti m.p. (2010) what about the taxonomical status of european straight-tusked elephants? quaternaire, ors serie, 3 pp. 27-28. schüler t. (2010) esr-datierung von zahnschmelzproben der archäologischen fundhorizonte von neumark-nord . dauerausstellung im landesmuseum für vorgeschichte halle: elefantenreiche eine fossilwelt in europa. the straight – tusked elephants from neumark nord: ... january 15, 2011 15 gennaio 2011 sess 0_retro e indice edi.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 geological setting of the pleistocene placers and roman gold mines of the ivrea morainic amphitheatre (piedmont, nw italy). franco gianotti dipartimento di scienze della terra, torino corresponding author: f. gianotti <franco.gianotti@unito.it> abstract: gianotti f., geological setting of the pleistocene placers and roman gold mines of the ivrea morainic amphitheatre (piedmont, nw italy). (it issn, 039-3356, 2011). various alluvial gold placers are distribuited along the outer edge of the ivrea morainic amphitheatre (ami). they were exploited in pre-roman epoch and mainly under the roman republic rule, as strabo and pliny the elder reported. the bessa “aurifodinae”, dated to ii-i century b.c., are the widest mine dumps (10 km2) constituted of rounded cobbles and boulders accumulations and anthropic stratified sandy-gravel fans. all the ami placers are proglacials, but they differ in stratigraphic unit, geomorphologic setting, age and genetic evolution. the mines are differentiable into exploitations with or without water channels, depending on water disponibility and placer wealth. riassunto: gianotti f., contesto geologico dei placer pleistocenici e delle miniere d’oro romane dell’anfiteatro morenico d’ivrea (piemonte, italia nw). (it issn, 039-3356, 2011). sul margine esterno dell'anfiteatro morenico d’ivrea si distribuiscono numerosi giacimenti alluvionali auriferi (placer) sfruttati in epoca pre-romana e romana repubblicana, attività citata da plinio il vecchio e da strabone. le "aurifodine" della bessa sono la miniera principale, unica ad essere datata (fase principale ii-i sec. a.c.), con discariche di miniera di estensione plurichilometrica (10 km2) a cumuli di ciottoli e conoidi antropici di ghiaie sabbiose stratificate. i vari placers sono suddivisibili per unità stratigrafica di provenienza (alloformazioni dell’anfiteatro di età medio-pleistocenica), per contesto geomorfologico (legati a scaricatore, come la bessa, oppure a sfioratore fluvioglaciale) e per età ed evoluzione genetica (placers monofasici e polifasici, in relazione al numero di cicli di risedimentazione a cui sono stati soggetti). come miniere si differenziano in sfruttamenti tramite canali d'acqua corrente, ulteriormente distinte in aurifodine a cantieri separati (bessa, mazzè) o aurifodine a cantiere unico ed omogeneo con canali paralleli e ravvicinati (baraccone di villareggia), e quelle coltivate con semplici scavi, senza utilizzo di canalizzazioni evidenti (villareggia, areglio, ronchi presso torre canavese ed altre minori), in dipendenza della disponibilità di acqua e del tenore in oro del singolo placer. key words: ivrea morainic amphitheatre, gold placer, pleistocene, roman mines, piedmont. parole chiave: anfiteatro morenico d’ivrea, placer aurifero, pleistocene, miniere romane, piemonte. excavation evidences and mine dumps are quite regularly distribuited over the outer (distal) margin of the ivrea morainic amphitheatre (ami), between the external moraines and the proglacial sandur (fig. 1). they are the result of proto-historical and historical exploitation of gold fluvioglacial placers, ranging from traces of decametric extension to the 10 km2 wide roman “bessa aurifodinae”. these activities were first cited by some classic authors such as the greek historian strabo, who named the dora baltea river used by the salassi people to gold washing (geografia, iv, 6.7). they were later recognized in modern age (durandi, 1767; de robilant, 1784) and described by a lot of historians, archaeologists and geologists (among these sacco, 1888; marco, 1932; carraro in bortolami et al, 1967; gianotti, 1992, 1996; baio & gianotti, 1996, pipino, 1998). since 1985 a regional park protects the bessa aurifodinae. only the bessa mine was dated on archeological basis. previous exploitations kept by the local ligurian-celtic populations (salassi and the mysterious ictimuli) are suggested by the pottery stratigraphy (gambari, 1999). after the roman occupation of the territory (140 b.c.) a intensive phase of exploitation lasted less than 100 years between the second and the first century b.c., according to the roman coins found into the cobble dumps (calleri, 1995). pliny the elder informs that the roman managers “publicans” were interdicted by law (nearly 70 b.c.; domergue, 1998) to employ more than 5.000 workman in ictumulorum aurifodinae (n.h., xxxiii, 4). the exhausted mine probably was already abandoned at the beginning of the first century a.d., when more remunerative iberian placers were being exploited (strabo, geogr. v, 1.12). the mine dumps take up the place of former alluvial gold placers strictly connected to the pleistocene glacialism of the dora baltea basin. indeed the petrographic composition of the dump cobbles indicates the auriferous deposits supply from the aosta valley. in this mountain catchment some primary ores outcrop, consisting mainly of tertiary hydrotermal quartz veins, as near brusson in the monte rosa gold district. most of the primary gold forms microscopic particles into the quartz and pyrite, but pedogenetic alterationof goldbearing rocks and their derived colluvial deposits aggregates gold invisible micrograins to form macro-agglomerates (“nuggets”). the reject deposits features (particularly the roundness of clasts and the sandy matrix good selection) suggests a fluvial origin of the former placer deposits. but the coarse granulometry of gold (mm) into placer deposits, located several tens of 183 185 184 km downstream the primary ores, indicates glacial (not fluvial) transport from the mountain catchment to the ami. here fluvioglacial deposits locally sedimented in proglacial fans to constitute monophasic placers (middle pleistocene). glacigenic deposits were subsequently reworked by glacial melting watercourses and by streams connected to the local drainage. the resedimentation of glacigenic deposits into stream channels produced further heavy minerals concentration with formation of richer polyphasic placers (middle and upper pleistocene). this process is part of the general razing of the amphitheatre and continues until at the present time. placer genesis was constrained and favoured by morainic morphology. two placer positions are identifiable according to the morainic relief. bessa placer (and its neighbouring mulino del ghé placer) is located in the left lateral sector of the amphitheatre and was genetically connected to outwash channels along morainic valley parallel to the morainic ridges (“scaricatori”). placers like this were at the beginning enclosed by the lateral moraines that supplied them in sediments. they correspond now to the top of flat high terraces, taking up areas formerly covered by glacigenic deposits that were later more or less completely reworked by fluvioglacial and fluvial erosion. the other placers are mostly distribuited in the frontal sector of the amphitheatre (mazzè, villareggia, baraccone, torre canavese, borgo d'ale) and correspond to the apical sector of proglacial fans that lie downstream to fluvioglacial cuts transversal to a morainic ridge (“sfioratori”). as regard to the placers stratigraphic setting, bessa placer has the oldest age and the longest evolution. it is located in an area formerly covered by tills, fluvioglacial and glaciolacustrine deposits related to the first three glaciations known in the ami dated from the end of the early pleistocene and the early middle pleistocene. this wide placer (5 km2) experimented more reworking cycles by glacial streams during some of the middle pleistocene glaciations. the main and last of them were linked to a meltwater stream of the dora baltea and viona glaciers during the magnano and serra glaciations, at the end of the middle pleistocene. quite all the little placers were formed during the middle pleistocene last glacial expansion (in ami named serra glaciation, correlable to mis 6; gianotti et al., 2008), because they are monophasic proglacial fan placers produced by fluvioglacial deposition of drift and prompt resedimentation of serra alloformation tills (fig.1). exceptions are some little placers to the south of bessa (3 in fig. 1) referable to a precedent glacial expansion (magnano glaciation) and partially reworked until present by local streams. mazzè placer is connected to the main fluvioglacial stream of the second-last glaciation (piverone glaciation; mis 4?). it is placed on a high terrace, suspended 30 m above the right side of dora baltea river, 1 km downstream the deep gorge through which the river leaves the amphitheatre. unlike the other little placers mazzè is a polyphasic one, because the mazzé gorge worked as ami main draining channel during the last three glaciations and the interposed interglacials and interstadials until present. on the opposite side of the dora gorge the villareggia placer is composed of different terraced fluvioglacial bodies ranging from serra to piverone glaciations. finally only one placer (baraccone at the south of villareggia) is probably connected to the “ivrea” glaciation, correlable to the global lgm (mis 2). it forms the top of a low terrace (5 m high) on the left side of the dora baltea river. the main polyphasic placers (bessa and mazzè) are now terraced 20-50 m above the stream to which they are derived from (viona and olobbia streams for bessa; dora baltea r. for mazzè). a dora baltea paleochannel is preserved along the fig 1. geologic sketch map of ivrea amphitheatre with main gold mines position. mappa geologica schematica dell’anfiteatro di ivrea con l’ubicazione delle principali miniere d’oro. f. gianotti 185 ms. received: testo ricevuto il a second exploitation type was carried out with many adjoining parallel superficial water channels (fig. 3) and was adopted for a complete exploitation of thin alluvial bodies forming extensive flat low terraces (baraccone). these two water-based methods could have been the model for the “gorge yard” and the “comb yard” (domergue et al., 1989) utilized a century later in the roman goldmines in spain. the minor placers corresponding to monophasic proglacial fans were exploited by simple excavations without water channels, owing to their distance from any water resource. this mining activity, partially explainable as research workings, is testified by the presence of hectometric wide areas only partially covered with cobble small piles and riddled with some meters deep cone-shaped pits (frascheia near villareggia and moncrivello, areglio-bose and madonna della cella near borgo d’ale, ronchi between baldissero and torre canavese and other minor sites). only for the bessa and mazzè sites running water was employed, probably because the aqueduct building cost (2 km long for bessa and at least 10 km for mazzè) was remunerative according to the placer extension and its higher gold grade. references baio m. & gianotti f. (1996) studio geologico e giacimentologico dell’area della “bessa” (biella, italia). geologia insubrica, 1 (1-2), 29-48. bortolami g., carraro f. & sacchi r. (1967) note illustrative del foglio 43 “biella” della carta geologica d’italia alla scala 1:100.000. serv. geol. it., roma. calleri g. (1985) la bessa. documentazione sulle aurifodinae romane nel territorio biellese. tip. unione biellese, biella, 200 pp. domergue c. (1998) la miniera d’oro della bessa nella storia delle miniere antiche. in: archeologia in piemonte, 2, tip. allemandi, torino. domergue c., fontan f. & herail g. (1989) les tecniques artisanales d’exploitation des gites alluviaux: analogies dans le temps et dans l’espace. chron. rec. min., 497, 131-138. durandi j. (1767) dell’antica condizione del vercellese e dell’antico borgo di santhià. aldina, torino. gambari f.m. (1999) premières données sur les aurifodinae (mines d'or) protohistoriques du piémont (italie). aquitania, 88-92. gianotti f. (1992) le coltivazioni romane del placer aurifero della bessa. in: dal piaz g. v. (ed.), le alpi dal monte bianco al lago maggiore. soc. geol. it., guide geologiche regionali, 3 (a), 196-197, bema, milano. gianotti f. (1996) bessa, paesaggio ed evoluzione geologica delle grandi aurifodine biellesi. quaderni di natura biellese, eventi e progetti ed., biella, 83 pp. gianotti f., forno m.g., ivy-ochs s. & kubik p.w. (2008) new cronological and stratigraphical data on the morainic amphiteatre of ivrea (piedmont, italy). quaternary international, 190, 123-135. marco c. (1932) la bessa. in “aosta. rivista della provincia”, ivrea. pipino g. (1998) l’oro della bessa. notiziario di mineralogia e paleontologia, 12, 16 pp. sacco f. (1888) i terreni terziari e quaternari del biellese. 16 pp., guadagnini & candellero, torino. western edge of the mazzè placer. on the contrary the monophasic placers are not terraced and they lie in areas lacking of watercourses, because of their position downstream of morainic passes hanging tens of meters on the ami internal alluvial plain (215 m). all the placer exploitations were open-air quarrying works. some tunnels into glacial deposits are reported in the bessa area, but they can be interpreted as research workings. three mine typology and related exploitation methods are discernable according to distribution and facies of reject deposits and overall derived morphology. exploitations by artificial water-channel wascarried out in contiguous but separate mining yards, everyone with a main deep evacuation channel (bessa, mazzè). this method produced two tipology of reject deposits. open-worked deposits of quite rounded cobbles and boulders (also erratic blocks), methodically accumulated in handmade piles 1-10 m thick on the terrace top in the site of the former placer (fig. 2). anthropic alluvial fans of clino-stratified clast-supported sandy-gravel with rounded pebble and cobbles, deposited downstream of the channel outlets on the lower alluvial plains surrounding the placer. fig. 2. rounded cobbles and boulders accumulations on the bessa aurifodinae upper terrace. cumuli di ciottoli e di blocchi arrotondati sul terrazzo superiore delle aurifodinae della bessa. fig. 3. buried channel sidewalls outcrop at the top of a low terrace on the dora baltea river left scarp (baraccone site, villareggia). this anthropic horizon lies on middle pleistocene fluvial sandy gravel. una successione di fianchi di canale sepolti affiora alla sommità di un basso terrazzo sulla scarpata sinistra del fiume dora baltea (sito del baraccone, villareggia). tale orizzonte antropico poggia su ghiaie sabbiose fluviali del pleistocene medio. january 14, 2011 14 gennaio 2011 geological setting of the pleistocene placers and ... sess 2_16022011_tpr3.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 implications of river system on recent tiber river alluvium anna chiara giacomi università di roma “sapienza”, roma corresponding author: a.c. giacomi <annachiara.giacomi@uniroma1.it> abstract: giacomi a.c., implications of river system on recent tiber river alluvium. (it issn 0394-3356, 2011) the study shows a geological/geotechnical model of the filling of the buried tiber river valley in the area of historical centre of rome. the stratigrafic reconstruction of the holocenic alluvial deposits, obtained by a 3d detailed engineering -geology model reconstructed by the observation of 78 geotechnical boreholes. starting from the model, it was possible to explain the river system evolution during pliocene-pleistocene. riassunto: giacomi a.c., implicazioni del sistema fluviale sui depositi alluvionali recenti tiberini. (it issn 03943356, 2011) il lavoro propone un modello geologico/geotecnico delle alluvioni del tevere nell’area urbana di roma. la ricostruzione stratigrafica è stata ottenuta attraverso 78 stratigrafie di sondaggio. dal modello è stato possibile poi interpretare l’evoluzione della sedimentazione fluviale nel pliocene-pleistocene. key words: tiber river valley, lythotipes, geometrical relationships, geological and geotechnical model. parole chiave: valle tiberina, litotipi, relazioni geometriche, modello geologico e geotecnico. 1.introduction: geological setting of the city of rome the area of rome was characterized by marine sedimentary conditions from pliocene through early pleistocene times (4.5-1.0 myr). this plio-pleistocene succession consists of alternating, decimetre-thick levels of clay and sand (bozzano et al., 1997). during middle-late pleistocene and holocene times, sedimentary processes were confined to fluvial channels and coastal plains and strongly controlled by glacio-eustatic sea-level changes (bozzano et al., 1997). in the same time, the region also experienced strong volcanic activity, causing the emplacement of a thick pyroclastic cover that became intercalated into the continental sedimentary deposits. the present-day hydrographic network of the tiber valley and its tributaries originated from the würm glacial (18 kyr) period result from re-incision and deepening of the valleys which resulted from previous glacial-interglacial phases. the sediments filling the holocene incisions are generally characterised by a fining-upward succession, with a relatively thin level of gravel at the base grading into a thick pack of sand and clay (bozzano et al., 2000). this fine-grained portion of the deposit is represented by normal to weak overconsolidated clayey and sandy silt, (bozzano et al., 2000). 2.the creation of the model the originality of the ricostruction is in the correlation in 3d of the filling of the tiber river valley in the area of the hystorical center of the city, adding some new elements in respect of that in bozzano et al. (2000, 2008). the geological reconstruction of this model was based on data stored from 78 continuously cored boreholes which were uniformly distributed within the belt delimited in fig. 1, from the tiber island to fig.1 boundary of the alluvial deposits in correspondence with the historical center of rome and location of 78 boreholes. fig.1 limiti dei depositi alluvionali nel centro storico di roma e ubicazione dei 78 sondaggi. 110 112 111 d a1 c g b1 r fig.2 3d engineering geology model and location of the section (down). fig.2 modello geologico-geotecnico 3d e ubicazione della sezione (sotto). the tor di quinto quarter. these boreholes, which range in depth from 30 to 67 m b.g.l., penetrate through the sediments filling the tiber river valley and, in numerous cases, terminate in the pliocene substratum (i.e. the monte vaticano unit). alluvial deposits have been classified by bozzano et al., (2000), like corazza et al., (1999). it was possible to construct a dem relative to the ancient erosional pleistocenic surface, using the autocad map3d software, to define spatial limits. the upper limit, between alluvial deposits and bedrock, has been traced according to the carta geologica di roma 1:10000 (funiciello r. & giordano g., 2008), and it was construed as the upper limits of the ancient tiber river valley currently contains holocenic alluvial deposits of the river. to construct a geological/geotechnical 3d model it was necessary to correlate the boreholes according to layers every 5m. in each layer physiographic, morphology and sedimentology criteria were used to the correlation, to extrapolate the point data in a bigger area. the operations shown above have been repeated for each deep investigation, for a total of 13 layers, from -45 m to +15 m. b.g.l.. thanks to an automatic process of extrusion, it was possible to transform the data from flat graphic sketches to a volumetric one. in this way all layers are joined together. fig.2 shows the 3d reconstruction of the tiber valley alluvial deposits. you can see a regular morphology of the valley, with a width of 2,5 km and a depth of about 60 m b.g.l.; the valley is characterized by steep vertical slopes, dug out of the monte vaticano unit. landslides and falling rocks could have happened during the aerial exposition. this is confirmed by the analysis of some boreholes situated near the banks of the tiber river. a probable interpretation could be that fragments of the landslides from the walls of the valley fell, while the pleistocenic-holocenic fluvial sedimentation was going on. the morphology of the valley is a possible result of an intense erosive process, due to a marine regression associated to the last glacial maximum dated at around 18.000 years ago. this event was responsible for the incision of hydrographic networks of the tiber river; tiber river cut a channel into the pliocene substratum to a depth of –50 m relative to the modern sea level, forming a wide valley of more than 60 m deep with sloping river banks and a flat thalweg. 3. geological interpretation of alluvial setting. the occurrence of gravel deposits (lithotype g) at the base of the alluvial succession for a constant thickness (10m) implies that the tiber river was initially a braided stream, whereas the transition to the finer sediments of lithotypes d and c indicates that it progressively became more meandering with the presence of vast palustrine areas (fig.2). at -45m b.g.l. there are some lenses of unit g in unit d that indicated erosional events: sand of d unit could be deposited where the tiber river has cut gravel alluvium, leaving isolated body of unit g near the river bank. the d bodies, sandy and sandy silt, may represent the principal riverbed, designed in central part of the valley: an upright river-bed, which with the passing of time became a meandering course, opposite to the actual one (see the d body in fig.2). clay and silty clay (lithotype c) are deposited on this basal gravel and form the major part of the alluvial fill. the unit c occurs as an almost continuous unit on the left bank of the present tiber river and has a total thickness of around 50 m (venezia square, popolo square, tor di quinto, campi sportivi street): it is due to the increase of sinuosity index and fine-grained overbank deposits were developed. the lateral heteropic relation between the implications of river system on recent tiber ... 112 ms. received: testo ricevuto il alternating silty-sandy, sandy-silt and clay levels of lithotypes d and c indicates the almost continual presence of tributaries between 18,000 b.p. and the present, defining an alluvial floodplain which was formed not only by the main tiber river but also by its right bank tributaries. between 13.000 and 8.000 years, the main tributaries valle dell’inferno and balduina streams, deposited two lateral bodies on the right bank (bozzano et al., 2000). the absence on the left bank of coarse alluvium indicates the lack of tributaries: it could be because of the ancient affluents witch dispersed to the wetlands (unit c). sandy and silty sandy (lithotype b1), interpreted like the main tiber river, indicates a more central position of the main channel in the valley than the present one. it is possible that about 3000 years ago there was a new erosive activity, with a bigger energy transport (alessio et al., 1992).it has also been confirmed by an erosional surface between c and b bodies (see section in fig.2). as lithotype b1 has a larger grain size than b2, it is likely that currents along the principal channel had a higher energy than those in the tributaries. the fact that the present course of the tiber river in the rome area is not centred in respect of the main b1 body suggests that it had a different trend. it could be anticipated that this would have been more rectilinear during the period of change described above, subsequently becoming more meandering in response to the rapidly decreasing rate of sea level rise and eventual stabilisation. however, the good correspondence on the northern side of lithotype c filled by b1–b2 sediments and the trace of the valle dell’inferno stream implies that the position of the right bank tributaries has remained nearly stable from the erosive event to recent times. on the river banks there are the ancient bodies of tributary b2: they are the bodies of valle dell’inferno and balduina streams from mt. mario mt. vaticano gianicolo on the right bank and spinon stream (at south) and aniene river (at north) on the left bank. the high thickness of unit c, in heteropic contact with b2 on the river banks, indicated that the wetlands around the tiber river and its tributaries were periodically flooded. the historical alluvium a1-a2 are finer-grained than b1-b2, showing a decrease in the transport capacity of both the principal river and its tributaries. the lithological variation between lithotype a1 (located around the principal riverbed) and a2 (further away) is probably due to the same reason on postulated for the difference between lithotypes b1 and b2: b1 body is central in the valley as a1 covers the actual tiber channel; b2 is only in some confluence areas, while a2 is everywhere, getting to the slopes of the valley. the thickness of both unit a and the anthropic fill material unit r on the left bank is similar to the one on right bank: it is possible that during the growth of ancient city of rome, and with this the anthropic fill deposition, on the right bank (prati quarter) frequently floods happened. here the unit a alluvium is more thick and continue. acknowledgements the author would like to thank prof. bozzano f. and dr. martino s. (university of rome “la sapienza”) for their very valuable suggestions and dr. lacchini a. for his helpful availability on the software knowledge. references alessio m., allegri l., antonioli f., belluomini g., ferranti l., improta s & manfra l, proposito a. (1992) risultati preliminari relativi alla datazione di speleotemi sommersi nelle fasce costiere del tirreno centrale (italy). g. geol. 54(2):165–193 bozzano f., funiciello r., gaeta m., marra f., rosa c. & valentini g. (1997) recent alluvial deposits in rome (italy): morpho-stratigraphic, mineralogical and geomechanical characterisationproc. int. symp. engineering geology and the environment, publ. 1, 1193-1198. bozzano f., andreucci a., gaeta m., salucci r. & rosa c. (2000) a geological model of the buried tiber river valley beneath the historical center of romebull. eng. geol. env., 59, 1-21. bozzano f., caserta a., govoni a., marra f. & martino s. (2008) static and dynamic characterizazion of alluvial deposits in the tiber river valley: new data for assesing potential ground motion in the city of romej. of geoph. res.113, 1-21. corazza a., lanzini m., rosa c. & salucci r. (1999) caratteri stratigrafici , idrogeologici e geotecnici delle alluvioni tiberine nel settore del centro storico di roma il quaternario 12, 131-176. funiciello r. & giordano g. (2008) note illustrative della carta geologica di italia alla scala 1:50.000 foglio 374 “roma”. dipartimento difesa del suolo, apat. a.c. giacomi january 14, 2011 14 gennaio 2011 imp.bersezio& aquifer architecture of the quaternary alluvial succession of the southern lambro basin (lombardy italy) riccardo bersezio1, fabrizio pavia1, mariangelo baio2, alfredo bini1, fabrizio felletti1 & cecilia rodondi1 1dipartimento scienze della terra, via mangiagalli 34, 20133 milano e-mail: riccardo.bersezio@unimi.it 2aquater, via emilia, san giuliano milanese (mi) abstract: bersezio r. et al., aquifer architecture of the quaternary alluvial succession of the southern lambro basin (lombardy italy). (it issn 0394-3356, 2004). aquifer stratigraphy of the sector of the pleistocene – holocene alluvial plain of lombardy, run by the lambro valley system south of milan, has been reconstructed on the basis of geological mapping at 1:10.000 and subsurface interpretation and correlation of more than 150 among water wells, boreholes and deep excavations. the middle (?) – late pleistocene sedimentary evolution of this sector includes four major progradation cycles of alluvial depositional systems that migrated from the alpine northern side towards the axial palaeo-po depositional system. these cycles were governed by pleistocene glacial cycles, in combination with ramp-folding of the san colombano – salerano apenninic anticlines and minor uplift of the alpine side. every major cycle is soled by an erosion surface, and is shaped by minor fining upward sequences. both major and minor sequences record at first the advance of coarse-grained units (distal braided alluvial fan or sandy braid plain) which fringe-out south-eastwards into meandering fluvial systems, and are replaced upwards by alluvial plain fines, which close the sequences. physical stratigraphy and geomorphology, analysis of facies associations, characterisation of gravel composition, radiocarbon dating on 4 peat and plant relic samples and findings of transported artefacts allowed the correlation of the four cycles with the regional evolution. the post glacial meandering depositional systems of the deeply entrenched lambro valley system (unit 4, holocene; unit 5, historical), are cut into the braided stream to meandering depositional systems that developed during l.g.m. times, at present outside the lambro valley (unit 3, late pleistocene). these represent the uppermost aquifer unit, i.e. the phreatic – non saturated zone. the underlying unit 2 (late pleistocene) can be correlated with the besnate allogroup, and therefore developed during the corresponding glaciations. it is formed by three stacked sequences, controlled by glacial cycles, which are deeply scoured into the lowermost succession that could be studied (unit 1 middle ? – late pleistocene ?). it represents the most important and permeable intermediate aquifer unit, that is only partly confined by the flood-plain fines of the uppermost sub-unit 2c. riassunto: bersezio r. et al., architettura degli acquiferi nella successione alluvionale quaternaria del bacino del fiume lambro (lombardia, italia). (it issn 0394-3356, 2004). nella pianura padana la conoscenza della geologia delle successioni continentali quaternarie, costituisce la base per la realizzazione dei modelli idrostratigrafici, di gestione delle acque sotterranee e per la programmazione della tutela e del risanamento ambientale. a questi fini è critica la comprensione dell’architettura deposizionale a scale diverse, sia per l’elaborazione di schemi idrostratigrafici regionali, sia per la modellazione del flusso e del trasporto degli inquinanti. in questa prospettiva la valle del lambro, a sud di milano, offre un caso di interesse generale per: 1) le relazioni tra acque superficiali fortemente compromesse ed acque sotterranee, 2) l’architettura deposizionale alluvionale altamente eterogenea, 3) la buona disponibilità di dati di sottosuolo. si è pertanto avviato un progetto di studio stratigrafico-sedimentologico e geofisico, cui farà seguito la modellazione dell’eterogeneità degli acquiferi a diverse scale. vengono qui presentati i risultati della ricostruzione geologica ed idrostratigrafica relativa al settore compreso tra melegnano (a nord) e s.angelo lodigiano (a sud), sulla base del rilevamento in scala 1:10.000 e dello studio stratigrafico e petrografico di affioramenti, sondaggi e pozzi per acqua (173 punti di osservazione su un’area di circa 60 km2, con profondità di indagine di 100 m). l’area in studio si sviluppa nella pianura lombarda meridionale, caratterizzata da pendenze medie della topografia minori di 1.5‰, dall’approfondimento degli alvei fluviali attuali, che decorrono entro scarpate di terrazzo di altezza decametrica e dalla presenza di un rilievo collinare di origine tettonica, con sollevamento attivo durante il pleistocene (colle di san colombano), poco a nord del livello di base del po. le tracce meandriformi dell’idrografia attuale e dei paleoalvei sono scolpite nella superficie del cosiddetto “livello fondamentale della pianura”. sono state suddivise cinque unità deposizionali informali, caratterizzate su basi stratigrafiche, petrografiche e di facies, che comprendono, dal basso: unità 1, sistemi deposizionali sabbioso–argillosi, con caratteri indicativi di ambiente fluviale meandriforme, con tetto individuato tra 50 e 70 m di profondità, da nord verso sud. essa comprende sequenze di facies fining-upwards, costituite da sabbie medie e fini, raramente ghiaiose, passanti a sedimenti fini, argilloso-limosi, con paleosuoli organici bruni. l’unità 2, sistemi deposizionali ghiaioso – sabbiosi, comprende due sub-unità ghiaioso–sabbiose (2a e 2b), incontrate dalle perforazioni a profondità di 20-25 m, interpretabili come tipiche di un ambiente di conoide alluvionale distale a canali intrecciati. esse passano a tetto ad una terza subunità (2c), sabbioso–limoso–argillosa, organizzata in sequenze di facies fining-upwards chiuse a tetto da argille organiche e paleosuoli bruni mal drenati, interpretabile come il prodotto della transizione tra un sistema di deposizione a canali intrecciati (settentrionale) ed un sistema di deposizione meandriforme (meridionale). le datazioni 14c relative alla base dell’unità 2c hanno fornito età (non calibrate) comprese tra 23.145± 340 a bp e 24.145±160 a bp; il tetto della stessa unità è stato datato a 22.035±300 a bp. le ghiaie che appartengono a questo gruppo di unità hanno composizione caratterizzata dall’abbondanza dei clasti metamorfici e magmatici, ampiamente prevalenti sui clasti sedimentari di provenienza sudalpina locale. l’unità 3, sistemi deposizionali sabbiosi, è costituita da sedimenti localmente affioranti, organizzati in due sub-unità (3a e 3b) formate da lenti sabbioso-ghiaiose e/o sabbiose, sviluppate tra il piano campagna e la profondità di 10-15 metri. a queste si associano sedimenti fini limoso-argillosi bruni, con paleosuoli organici intercalati. questi corpi, talora delimitati da orli relitti di terrazzi di altezza metrica, comprendono i depositi dei corsi d’acqua meandriformi delle paleovalli del sillaro (ad est del lambro) e del paleoalveo carpiano-bescapè (ad ovest del lambro). questi sedimenti vengono a contatto, per mezzo di una superficie erosionale inferiore, sia con i sedimenti fini a tetto dell’unità 2c, sia con le sabbie e ghiaie ad essi sottostanti (unità 2c inferiore e 2b). il tetto dell’unità 3a è stato datato in un punto di misura compreso tra il dominio del lambro e quello del sillaro, a 18.785±230 a bp, calibrabile ad età comprese tra 19.909 e 20.785 cal bc. le unità 4 e 5, sistemi deposizionali antichi e post-glaciali della valle del lambro, sono costituite da sedimenti di ambiente fluviale meandriforme, organizzati in unità minori, contenute all’interno delle scarpate che delimitano questo sistema vallivo. si tratta di depositi sabbiosi e ghiaioso-sabbiosi (barre di meandro e ventagli di rotta) associati a subordinate successioni di sedimenti fini, limosi ed argillosi, di argine, piana di esondazione e di abbandono di canale. questi sedimenti si distribuiscono su tre ordini di terrazzo, sopraelevati più di 10 m rispetto alla quota dell’alveo di massima piena attuale del lambro. il terrazzo più recente, ancora sopraelevato fino ad oltre 6 metri sulla piana attuale, rappresenta le fasi di deposizione avveil quaternario italian journal of quaternary sciences 17(2/1), 2004, 361-378 362 r. bersezio et al. 1 introduction modelling groundwater flow in alluvial aquifers requires the preliminary elaboration of conceptual models of subsurface geology, including hydrostratigraphic properties of the sediments. the hydrostratigraphic models must take into account the geometry of aquifer/aquitard/aquiclude units, their hydrodispersive properties, their connectivity and must include the evaluation of incertitude on the parameters (see for instance anderson, 1997 or huggenberger & aigner, 1999, with references therein). a multidisciplinary approach is therefore necessary, by the integration of geological, sedimentological, geostatistical and numerical methods, with emphasis on the geological reconstruction. we apply such an approach to the study of aquifer dynamics of the southern lambro valley, south of the milan conurbation, close to the confluence with the main axial fluvial system of the present day lombardy plain, the po river (fig. 1). the final goal is that of elaborating the hydrostratigraphic model of the main aquifer groups (regione lombardia-eni, 2002), with attention to the shallowest hydrostratigraphic units of middle p.p. upper pleistocene age, in the alluvial plain between ticino and adda rivers, south of milan (figs. 2 and 3) and of the holocene to recent units above them. this will provide the basis for modelling groundwater flow through these aquifer groups and their confining layers. the research is in progress, following three steps: a) survey and elaboration of the geological model, incorporating geometrical, stratigraphic, petrographic and facies information at several scales (i.e. from surface mapping to outcrop sedimentology, boreholes, well and log analyses); b) elaboration of the hydrostratigraphic model, which will be inclusive of the semiquantitative geological model and of the geostistical 3d reconstruction, after which the evaluation of incertitude on estimates of distribution of hydrodispersive properties of the individual units will be possible; c) numerical modelling of flow, starting with the attempts to upscale local properties to the wider regional scales. here we present the semiquantitative geological and hydrostratigraphic model. the results of numerical modelling of groundwater flow will be addressed elsewhere. nute con certezza in tempi storici, databili per il sistematico ritrovamento di frammenti di laterizi e manufatti, da romani a rinascimentali, embricati nelle forme di fondo ghiaiose (sub-unità 5b). la composizione delle ghiaie delle unità 3, 4 e 5 differisce fortemente dalle sottostanti, per la minima quantità di litici metamorfici e cristallini in genere, per il grado di alterazione di questi ultimi, che ne suggerisce il riciclo, e per la dominanza dei clasti sedimentari provenienti dalle unità mesozoiche sudalpine delle prealpi lombarde. sulla base della ricostruzione stratigrafica e deposizionale è stato realizzato un primo modello geometrico della successione pleistocenica superiore, che consente di prevedere e quantificare l’estensione e la localizzazione delle unità limoso-argillose (acquitardi) e dei principali corpi ghiaioso-sabbiosi (acquiferi). il modello consente una stima del grado di connettività verticale ed orizzontale tra unità acquifere diverse, fornendo una prima approssimazione relativa alle relazioni tra acque superficiali e prima falda (o “gruppo degli acquiferi a”, eni-regione lombardia 2002). l’evoluzione geologica ricostruita tra il pleistocene superiore e l’attuale, evidenzia due cicli di progradazione della parte distale di un sistema deposizionale di conoide alluvionale settentrionale (unità 2a-2c), su un sottostante sistema fluviale a canali stabili e trasporto misto, verosimilmente di tipo meandriforme (unità 1a-b). l’insieme di questi sistemi deposizionali era alimentato da valli in grado di drenare la catena alpina fino allo spartiacque. il sistema deposizionale dell’unità 3 appartiene verosimilmente all’ultimo massimo glaciale (l.g.m.), mentre le unità 4 e 5 rappresentano le unità post-glaciali, sviluppatesi durante l’olocene, quando la presenza dei laghi pedealpini ed il mutato quadro morfo-climatico, determinarono la prevalenza dell’alimentazione locale dalle prealpi, l’ampliamento verso nord dei sistemi deposizionali meandriformi, l’avulsione (sillaro, paleoalveo carpiano bescapé) e/o il rapido approfondimento (lambro, lambro meridionale) delle valli fluviali. key-words: alluvial sediments, aquifer sedimentology, hydrostratigraphy, quaternary, lombardy. parole chiave: idrostratigrafia, lombardia, quaternario, sedimenti alluvionali, sedimentologia degli acquiferi. fig.1 location map of the lambro valley system and study area. the external thrust fronts of the apennines are indicated with bold ornamented triangles; the most external thrust front of southern alps is ornamented with empty triangles. the study area is framed in white. ubicazione del sistema vallivo del lambro e dell’area in studio. i fronti esterni dei sovrascorrimenti appenninici sono indicati con triangoli neri; i fronti esterni sudalpini sono indicati con i triangoli bianchi. l’area in studio è riquadrata in bianco. 2 regional geology of the lambro area the lambro valley is entrenched into the alluvial plain of southern lombardy (fig.1), which is characterised by a very low slope gradient (less than 1.5‰) towards the po base level. the present-day fluviatile network, south of milan, is confined within narrow terraced valleys, bounded by scarps which are 5 30 m in height. at present the lambro valley runs across the area between the major valleys of ticino (west) and adda (east). the catchment areas of these two rivers reach the core of the alps, crossing the sedimentary south-alpine nappes, their variscan metamorphic basement units and the metamorphic alpine nappes of the central alps, just north of the insubric line. downstream their mountain course, two large alpine lakes (verbano and como lakes) started to sieve detritus fed from the internal alps, since post-glacial times. on the contrary, the lambro catchment is much smaller (similar to the olona and seveso basins west of it), reaching at present only the southernmost reliefs of the south-alpine edifice, where only mesoand cenozoic 363aquifer architecture of... rocks are exhumed. outside and above the holocene valleys, south of milan, an abandoned fluviatile network is sculptured into the so-called "livello fondamentale della pianura" (see castiglioni & pellegrini, 2001; marchetti, 2001 with references therein). this consists of several groups of nw – se meandering traces bounded by low height scarps (always less than 5 m in height), which show a marked change in strike downstream (i.e. southward), to a wnw – ese average direction (bersezio, 1986). these relics of abandoned rivers are sometimes run by underfit streams with 2nd order meanders (e.g. roggia barona and colatore lissone, west of the lambro river, sillaro underfit stream, east of the same; veggiani, 1982; bersezio, 1986). the san colombano hill rises at the southern end of the lambro valley (fig. 1). it developed as a consequence of tectonic uplift of an apenninic anticline, which deformed at least the lower pleistocene and probably also the middle pleistocene sediments (desio, 1965; ariati et al., 1988; alfano & mancuso, 1996; tellini & pellegrini, 2001; fantoni et al., 2003 with references). fig.2 topography of the study area and index map of the data points. equidistance among isohypse is 2 m. schema topografico dell’area in studio ed ubicazione dei sondaggi, pozzi, affioramenti e sezioni stratigrafiche. l’ equidistanza è di 2 m. 364 the se-verging fluviatile network of southern lombardy is tributary of the axial fluvial system, about e-w trending, i.e. the present-day and palaeo-po, which drains the nappe systems of the western alps and north-western apennines, up-current in respect to the lambro confluence. the deep subsurface geology of the po plain of lombardy is portrayed mostly by the seismic and well data, which are property of the oil companies. the tectonic substratum of the plio-pleistocene succession is formed by the external south-verging fronts of the southalpine fold and thrust belt, involving the meso cenozoic formations (milan belt of laubscher, 1985; see also pieri & groppi, 1981; cassano et al., 1986). in the central po plain, at the tip of the south-alpine thrusts, gentle anticlines are shaped within the tertiary clastic wedges, (“southernmost po plain structures”, i.e. corneliano, caviaga, soresina structures; bersezio et al., 2001; fantoni et al., 2003). these folds, which are offset by the northward propagation of the youngest external front of the north-verging apenninic thrusts, were deformed after deposition of the syntectonic lower messinian units and were sealed by the uppermost messinian lower pliocene sediments (fantoni et al., 2001). since the latest messinian, the evolution of the southalpine front was therefore controlled mostly by flexuration of the po plain foreland, due to emplacement of the apenninic tectonic load, which resulted in a 5 6° southward dip (pedealpine homocline; pieri & groppi, 1981). tectonic activity on the apenninic side lasted until pleistocene, as it is documented by uplift of the san colombano al lambro and salerano structures, which involve the lower (and middle?) pleistocene sediments (alfano & mancuso, 1996; fantoni et al., 2003). the quaternary terrigenous succession developed above the pliocene, deep marine units. it is formed by a clastic succession, at places more than 700 m thick, which shows a large-scale regressive trend, from the top of the pliocene deep water units, to the pliocene – middle pleistocene shelf and deltaic sediments and finally to alternating coarse and fine-grained alluvial units (middle – upper pleistocene) (dondi & d’andrea, 1986; regione lombardia eni, 2002, with references therein). based on seismic and well data of eni’s property, this large-scale stratigraphic architecture has been correlated to the northwards propagation of apenninic thrusts, which forced the fan-delta of the palaeo-ticino, adda, and apenninic rivers and the central palaeo-po deltaic apparatus, to prograde, filling the former marine basin. at the site of the present-day lambro valley system, the latest shallow shelf and delta sediments should be of early middle pleistocene age (older than 0.87 ma; muttoni et al., 2003). since that time, fluviatile and glacio-fluvial sediments, mostly controlled by climatic/eustatic cycles and subsidence rates, spread over the study area, building a sand – gravel succession up to 100 m thick. its lower part has been described by regione lombardia – eni (2002) as arranged in two main fining upward sequences, which are covered by an upper, coarse grained, non – cyclic unit of late pleistocene age. in the recently proposed hydrostratigraphic classification of regione lombardia – eni (2002), the latter coarse grained unit represents the shallowest aquifer group a, which overlays the cyclical sequences of aquifer group b. both these groups correspond to the traditional aquifer of martinis & mazzarella (1971), and include the three aquifers (“lithozones”) recognised by avanzini et al. (1995) and francani (2001). at present no other modern stratigraphic classification, in terms of allostratigraphic units or ubsu (nacsn, 1983; issc salvador, 1987), based on basin-scale correlations with glacial and glacio-fluvial units, is available. 3 methods the geological model of the middle (p.p.) upper pleistocene sediments of the lambro valley has been obtained after 1:10.000 geological mapping of an area of about 120 km2 (only a part, as large as about 50 km2 is represented in fig. 3), and subsurface analysis based on 173 points among excavations, natural outcrops, water wells and boreholes (fig. 2). some wells attain a depth of about 100 m below the topographic surface, but the majority of boreholes reach a maximum depth of some 50 m. this holds also for the closely spaced borehole transect, drilled for the tav project (high capacity railway). these subsurface data allow a more detailed study for the stratigraphic units which form aquifer group a than for the underlying group b, which is not the prime objective of this work. stratigraphic analysis was based on identification, hierarchization and correlation of the discontinuities which frame the different rank depositional units (sensu miall, 1996). in order to integrate surface and subsurface data we adopted a simplified classification for ranking discontinuity surfaces and depositional lithosomes: 1st order surfaces frame 1st order units of the rank of the depositional systems (i.e. associations of major valley/channel fills and correlated levee, crevasse splay and flood plain areas where present); these surfaces are represented in the field by the major terrace scarps and in cross-section (outcrops or subsurface correlation grid and borehole stratigraphy) by surfaces that intersect and/or collect all the other stratigraphic boundaries, framing several stacked minor sequences or bedsets; 2nd order surfaces frame units of the rank of depositional elements (for instance, fining upwards sequences of point bar accretion within meandering channels); these are recognised in outcrops and boreholes; in the latter case they are represented by gravel sand bedsets with a lower sharp boundary above finer grained units and/or silt mud intervals; in the cross-sections their lower boundaries do not cut across the 1st order surfaces; 3rd order surfaces frame units of the rank of architectural elements (e.g. macroforms or minor channel fills); they are easily recognised in outcrops and correspond to the individual bedsets in boreholes, framed by boundaries which are cut by, or merge with, the 2nd order surfaces. thorough facies identification and coding could be applied only at outcrop observations. in this case we adopted miall's (1996) classification, slightly modified to specify the grain size mixtures (tab. 1). the study of wells and boreholes was based on a purely textural classification and encoding of sediments (tab.1), when only disturbed samples were available. a more complete coding, including also sediment structure, could be adopted in the cases of undisturbed borehole samples r. bersezio et al. 365 fig.3 geological map of the study area. the two sketches represent 1) a general stratigraphic cross – section located along the a-a’ trace; 2) line drawing of pit exposure of sub-unit 5b. carta geologica dell’area in studio. i due schemi rappresentano: 1) schema dei rapporti stratigrafici ricostruito attraverso la sezione aa’; 2) rappresentazione in affioramento dei caratteri della sub-unità 5b. aquifer architecture of... 366 (cohesive sediments and rare cores). compositional analysis of gravels was used to support correlations and to separate provenance of clasts from regional or local sources. some 70 samples of gravel were collected, both in outcrops and boreholes, in the size range of -3φ to -5φ, for classification and counting of at least 100 pebbles for sample. we used these data as a qualitative tool to characterise the different depositional units and to assist correlations. radiocarbon age determinations on 4 samples of peat, organic soils and plant relics provided dating of the bases of the youngest upper pleistocene units. artefact fragments, which were deposited like clasts in fluvial bedforms, added age information on the holocene, historical units. subsurface mapping of 1st order boundaries between the major stratigraphic units was obtained after ordinary kriging, assisted by variogram structural analysis (matheron, 1969). 4 depositional architecture of the southern lambro basin five 1st order depositional units, bounded by 1st order surfaces, build the alluvial architecture of the middle pleistocene (p.p.) holocene succession, down to about 100 m below the topographic surface, corresponding to aquifer groups a, b and probably uppermost c (regione lombardia – eni, 2002). we numbered them starting from the deepest (unit 1) and in this order they are described in the subsequent paragraphs. the top surfaces of units 3, 4 and 5 are assembled to build the present-day topography (figs. 3 and 4). units 1 and 2 are subsurface units with no relations with the present day geomorphology. only the top of unit 2 is rarely exposed by the lambro terrace scarps or by the deepest quarry excavations. 4.1 subsurface units unit 1 – sandy – clayey depositional system unit 1 (fig. 4) is the lowermost subsurface unit which was crossed by the available boreholes and wells, and consists of sand, silt and clay facies, arranged in fining upward sequences. unit 1 gets progressively more sand-rich from the base upwards. it develops between a maximum top elevation of 45 m and a minimum base elevation of -20 m above sea level (figs. 5 and 6). its lower boundary is a 1st order discontinuity surface, represented by the sharp contact of sandy layers above thick, grey, silty-clay deposits, which deepens southwards from –10 to –20 m a.s.l. the top boundary deepens from north to south (i.e. from melegnano to s.angelo lodigiano; fig. 2 and fig. 5, sections 3 and 11), from 45 m a.s.l. to about 10 m a.s.l., being dissected by an erosion surface. unit 1 is formed by two subunits (1a and 1b; figs. 4, 5, 6), separated by a silt-clay interval. they are both formed by stacked 2nd order sequences, up to 10 m thick, with fining upward trends. each minor sequence develops above silts and clays, with a lower sharp boundary and includes a lower grey to yellowish sand unit, sometimes with gravel divisions (csg, ms and fs facies associations; tab. 1 and tab. 2); it is progressively covered by very fine sands and silty clays (vfs, sl, cl, c facies), sometimes cemented, with intervening dark organic soils and some peat. the sand facies associations form flat lens-shaped bodies, with longitudinal (about n-s) length of hundreds of meters and transversal width (about e-w) of tens of meters. a thinning of these bodies corresponds to a facies transition towards sand/silt-clay, thin bedded alternation. the fine-grained sequence which separates sub-units 1a and 1b has an average thickness of about 10 m and is present throughout the entire area except for the casalmaiocco zone (fig. 2; fig. 5, section 3), where it is eroded and replaced by the lowermost sand-body of sub-unit 1b. it is characterised by thin-bedded alternating fs, ls and lc facies, with peat layers and greygreen palaeosoils. differently, at the top of sub-unit 1b only discontinuous lenses of fines are present, also due to truncation at the top. geometry of sedimentary bodies and sediment assemblage of unit 1 point to a mixed – load fluviatile depositional system, with stable channel-fill depositional elements (lens-shaped sand-bodies forming 2nd sediment textures code sediment structures codes (all observations) (outcrops, excavations, pits) gravel g normal graded n sandy gravel gs inverse graded i gravelly sand sg horizontal parallel laminated h sand s low-angle laminaled l silty sand sl planar cross laminated p clayey sand sc trough cross laminated t sandy silt ls small scale trough cross lam. r silt l clayey silt lc additional textural codes clayey-sandy silt lcs very fine vf silty clay cl fine f sandy clay cs medium m gravelly clay cg coarse c clay c very coarse vc peat p tab.1 sediment classification and facies encoding used to describe surface and subsurface units. classificazione dei sedimenti e codifica di facies utilizzata per descrivere le unità in superficie e nel sottosuolo. r. bersezio et al. order sand-silt fining-upwards sequences, soled by low-rank erosion surfaces and capped by organic-rich sediments), crevasse splay (and possibly levee?) depositional elements (isolated thin bedded sand-silt lenses, thin-bedded clay-silt-sand alternations) associated with humid flood plain deposits (organic-rich silt-clay facies with alluvial-type palaeosoils). in addition to these features, the horizontal and vertical cross-cut relations among sand-bodies suggest a deposition dynamics governed by lateral migration, channel truncation/abandonment and channel avulsion. it is therefore suggested that sub-units 1a and 1b represent two stages of evolution of a meandering river depositional system, even if well data do not allow the recognition of the lateral accretion units. sediment load was medium sand and fines, with minor fine gravel in the lower stage, coarse sand with gravel and fines in the upper one. the first migration of a meandering channel system (1a) was followed by the establishment of a wide flood plain, where soil could form over flat and stable surfaces, due to either major avulsion or backstepping of the fluvial system as a consequence of rising base-level. after the scouring of an erosion surface, a new south-eastward migration of the depositional system, with coarser sediments, occurred (sub-unit 1b). the n-s sections of fig. 5 show the facies transition that occurs in less than 15 km towards the se, within both the sub-units, from sand-dominated and thickbedded towards fine-dominated and thin-bedded facies associations. 367 fig.4 middle pleistocene – holocene stratigraphy of the lambro basin, based on surface data, water wells and boreholes. location of the n-s cross section is in fig. 2. gravel composition of the stratigraphic units is reported in the low right insert. stratigrafia della successione del pleistocene medio p.p. – olocene nella zona del lambro, basata sui dati di superficie e di sottosuolo. l’ubicazione della sezione stratigrafica e dei sondaggi è riportata in fig. 2. l’inserto in basso a destra presenta la composizione delle ghiaie di 4 delle 5 unità stratigrafiche studiate. aquifer architecture of... 368 fi g. 5 lo ng itu d in al c ro ss s ec tio ns (a b ou t n -s ) a cr os s th e la m b ro a re a (lo ca tio n in f ig s. 2 an d 3 ). s ez io ni s tr at ig ra fic he lo ng itu d in al i ( ci rc a n -s ) n el la z on a d el l am b ro . l ’u b ic az io ne è r ip or ta ta n el le f ig . 2 e 3 . r. bersezio et al. unit 2 – gravel sand depositional system unit 2 (fig. 4) is a subsurface unit, whose top develops between 85 m and 45 m a.s.l (north) and base between 62 – 10 m a.s.l. (south), with a thickness ranging 13 – 52 m. it consists of gravel and sand bodies, with minor fine grained layers (mostly silt, rare or no clay), which form three sub-units (from bottom to top 2a, 2b and 2c). only the uppermost one (2c) crops out locally in the deepest scours of the lambro valley; it presumably corresponds to the sand-gravel units which are exposed at the topographic surface of the “livello fondamentale della pianura” just north of the study area (strini, 2001; bini et al., this volume). the stacking of sub-units 2a and 2b determines a clear coarsening upwards trend, which is followed by two fining upwards minor sequences, corresponding to sub-unit 2c). the lowermost sub-unit 2a develops above a lower discontinuity which deepens southwards, deeply dissecting unit 1. in the northern sector of the study area the sub-unit consists of sands and gravelly sands (facies association is presented intab. 2) stacked in non-cyclical bedsets, up to 10 m thick, which alternate with thin and discontinuous fine sand-silt layers. south of the salerano – lodi vecchio area (fig. 2, and fig. 5) a transition to stacked fining upwards sequences, up to 10 m thick with sand silt facies association occurs (tab. 2; fig. 5). subunit 2b is the coarsest lithosome, formed by coarse and massive gravel bodies, up to 10 m thick, with minor sand layers (see facies association in tab. 2). the gravel bodies are rarely separated by grey – brown silt and mud layers and possibly palaeosoils. in the same northern sector, as referred to just above, sub-unit 2b merges with sub-unit 2a, forming a unique gravel body, up to 30 m thick. the two subunits deepen and get progressively separated southwards, owing to the facies transition towards sand – silt fining upwards sequences, which is observed also for sub-unit 2b. the top of the gravel body is sharp and locally shows weathering profiles, which develop on some metres in thickness (munsell colours 7.5yr5/6, 5yr5/6). sub-unit 2c is formed by one (south) or two (north) fining upwards sequences (up to 15 m thick) of dark grey, coarse middle sand, silt to mud facies (tab. 2; figs. 5 and 6), frequently capped by organic-rich palaeosoils and some peat layers, with a total thickness ranging from 30 m to 3 m, the latter case due to top truncation at the base of units 3 to 5. the exposed sections of this sub-unit show that these sequences are formed by large-scale, trough cross-laminated sands in 369 fig.6 – transversal cross sections (about e-w) across the lambro area (location in figs. 2 and 3). sezioni stratigrafiche trasversali (circa e-w) nella zona del lambro. l’ubicazione è riportata nelle fig. 2 e 3. aquifer architecture of... association with planar, high-angle, cross-laminated sands and low-angle to sub-horizontal laminated sands (tab. 2). this association is frequently covered by alternating, thin-bedded, rippled fine sands and laminated to massive silt and silty mud (tab. 2). a facies transition occurs southwards, towards more mud-rich and thinbedded successions (fig. 5, sections 3 and 11). the upper part of sub-unit 2c (figs. 5 and 6) is represented by a widely distributed and continuous succession of laminated to massive, fine grained facies (silty and sandy mud, muddy silt), frequently interbedded with organic-rich palaeosoils and some peat. lenses of grey, laminated to massive mud occur recurrently; they contain plant relics, sometimes metre-sized, continental gastropods and other molluscs. within these fine grained facies association, decimetre-thick sand lenses are present. gravel composition of sub-units 2 a, b, c is quite homogeneous, with rare exceptions, as it is shown in fig.4. excluding the ubiquitous and uniformly distributed quartz pebbles, crystalline rock fragments are almost invariably dominant on sedimentary rock pebbles, with some fluctuations of the relative proportions. the most abundant rock clasts are gneisses and micaschists, with some phyllites and slates (up to 50 % in some samples), invariably associated with igneous rocks (up to 15 %), which include granitoids, granodiorites, rhyolites and intermediate to basic porphyritic volcanites. rare green metabasite fragment and serpentinite complete the crystalline rock composition. sedimentary rock pebbles are never more abundant than 20%; they are mostly represented by limestones, cherts, sandstone-siltstones (among which the collio – verrucano, the cretaceous flysch and the gonfolite sources are easily recognised), rare marlstones. they can be generally correlated with the southalpine sedimentary cover, with no clear indications of apenninic or other alpine provenance. some samples of plant fragments, collected in one temporary exposure due to excavations and in two boreholes, yielded radiocarbon ages relative to sub-unit 2c. its lower sandy succession has been dated between 23.145+/340 a bp. (fig. 6, section 1) and 24.620+/160 a bp. (fig. 5, section 4); these non-calibrated ages are realistically close to the age of the 2b – 2c boundary. the fine-grained top interval of sub-unit 2c has been dated to 22.035+/-300 a bp, by a sample collected in an excavation just south of melegnano (fig. 2). the architecture of unit 2 can be interpreted on the basis of grain size distribution, stacking patterns, exposed facies associations and gravel composition. its development marks a sudden change of depositional style, that occurs after truncation at the top of the deposits of the meandering fluviatile depositional system of unit 1. sub-units 2a and 2b can be interpreted as the result of sudden invasion of the former alluvial plain by bedload and debris flow – dominated, depositional systems, during at least two different increments of southwards progradation of a distal alluvial fan with braided stream alluvial style. a southward transition to a 370 unit sub unit facies association interpretation 5c vfsl, lcs, p flood plain, oxbow lake (river exposures) gsh, sgt, msp, mst, fsr point bar, transverse bar 5 5a 5b sn, si, fsr, vfsln, ls, lcs, p flood plain, oxbow lake, crevasse (exposures) sg, sgp, sr, lcs, cl, p chute channel, abandoned channel sgn, msgp, sgt, mfsr, lcs point bar 4 (boreholes lcs, fsh, fsr, slm, p flood plain, oxbow lake, crevasse exposures) csn, msp, mst, fsr, fsl, lcs sand bar, point bar, chute channel 3 3b vfsl, lcs, cls, p flood plain, oxbow lake (boreholes rare msgl, msg, sp, st, fsr, lcs point bar, channel fill exposures) 3a (boreholes) cfs, sn, mfs vfs lcs, lc sand bars, flood plain 2c (*) mst, msp, msh, msr, fsl, lc) point bars, abandoned channel fills (°) subsurface (°) ms, vfsl, lcs, l, lc, cl, p flood plain, crevasse splays, soils (*) exposures (°) sg, s, l, lc, p abandoned channel fills (°) csg, cs, ms, fs, fsl sand bars – point bars 2 2b sg, cs, ms, fs, l sand bars, braid plain subsurface g, gs, sg, cs gravel bars 2a fs, fsl, cl, c flood plain, alluvial soils subsurface sg, cs, ms sand/gravel bars, channel fills 1b ms, fs, cl, p abandoned channel fills 1 subsurface csg, cs, fs, cl lateral accretion bars 1a fs, vfs, sl, c, p flood plain, crevasse splays, soils subsurface ms, fs, cl channel fills – point bars tab.2 facies association and interpretation of the five depositional units. codes as in tab. 1 associazione di facies e relativa interpretazione delle 5 unità individuate. codifica come in tab. 1. r. bersezio et al. sandy braid-plain, characterised by channel sequences flanked by flood plain sub-environments, is documented by fringing-out of the gravel units and facies change to a sandy silty succession. a generalised back-step of this depositional system is recorded by sub-unit 2c, which is characterised by sandy facies associations, with abundant fines at the top and within minor sequences. it testifies the transition from a sandy braid plain (north) to a mixed-load depositional style (south), with development of point bars, which is typical of meandering fluvial systems. the fine-grained interval at the top of sub-unit 2c documents the wide diffusion of a flood plain across the entire study area, due either to another back-step of the sand dispersion system, or to an avulsion, capture, or inactivation of the depositional system. compositional uniformity suggests that no major change of the source areas occurred during the different progradation-retrocession steps recorded by unit 2, whose gravels show a mixed north-alpine – south-alpine provenance. 4.2 surface units the upper boundary of units 3, 4 and 5 is the present-day topography. in particular the top of unit 3 forms the largest part of the “livello fondamentale della pianura”, an almost flat surface, sse dipping on average by 1.125‰, which is cut by the terrace scarps of the lambro valley system. the livello fondamentale is run by the meandering traces of the abandoned river network, the most continuous of which are the carpiano – bescapè abandoned stream (west of the lambro valley; bersezio, 1986) and the sillaro meandering trace, to the east (veggiani, 1982; bersezio, 1986). at present these traces are bounded by 1 – 5 m scarps; the average radius of bends is comparable in length with that of the meanders of adda or ticino rivers, i.e. one order of magnitude larger than the present-day and abandoned lambro, olona and seveso river bends. the width of the lambro river valley, sculptured into the livello fondamentale, varies from about 2 km (north) to less than 1.5 km (south; fig. 3). the valley is formed by four orders of minor terraces bounded by different height scarps. the transversal profile of the valley is strongly asymmetrical. three orders of minor terraces are generally observed at the eastern side; they link progressively the elevation of the livello fondamentale with the present day lambro stream, which is lowered by about 15 m. differently, only two terraces are present at the western side, where the difference in height with the livello fondamentale is almost totally achieved by one major scarp, on the right hand of the present-day valley (fig. 3). moreover, the elevation of this western terrace within the valley, is higher than the others on the opposite side, suggesting that no correlation is possible between them. the western and most elevated terrace bounds the top of depositional unit 4; the other minor terraces represent the top surfaces of the different subunits which form the most recent unit 5 (sub-units 5a, 5b and 5c; fig. 3). unit 3 – sandy depositional system unit 3 is the uppermost stratigraphic unit outside the most external terrace scarp which bounds the lambro valley system; it is poorly exposed and crossed by a few boreholes and wells. it includes two sub-units (3a and 3b in ascending stratigraphic order) which develop with a maximum total thickness of about 15 m. sub-unit 3a is bounded at the base by an erosion surface, scoured into the uppermost fine-grained horizon of sub-unit 2c. to the west of the lambro valley subunit 3b is difficult to separate from 3a; differently, to the east of the valley, it forms the uppermost unit between lambro and sillaro, just above sub-unit 3a, or can be deeply scoured into sub-unit 2c (figs. 3, 5 and 6). on the whole sub-unit 3a forms a sandy fining upwards sequence, with discontinuos fine-grained layers and palaeosoils at the top. it is formed by kmsized, coarse to middle sand lenses, dark brown to yellowish in colour, which are locally separated by thin siltmud units (tab. 2). also sub-unit 3b is formed mostly by sand lenses, with a typical yellowish-brown colour and shows a general fining upwards trend, from coarse sand with rare gravel to sandy silt and mud. rare outcrops show the association of graded, gravelly-sands with dm-thick beds of coarse to middle sand with trough cross lamination and low-angle oblique laminasets (tab. 2). these lenses grade upwards to sandy-silt and siltyclay layers, with yellow orange to reddish paleosoils (munsell colours range from 10yr6/8 to 7.5yr5/8 and 2.5y6/6). the meandering palaeo-streams which characterise the top boundary of sub-unit 3b (sillaro and carpiano – bescapè among others) are characterised by the presence of gravel and sand deposits. these abandoned stream traces are cut 1-5 meters below the top of sub-unit 3b, with a top elevation which is in some cases comparable with that of the top of unit 4, which is going to be introduced later on. at present these observations do not seem to be sufficient to correlate these deposits with those of unit 4, but their stratigraphic attribution is still open. therefore we included provisionally these sediments within unit 3, with the specific definition of “unit 3 – abandoned streams” (fig. 3). gravel composition of unit 3 has been obtained mostly for the different sub-units of the group 3b, as far as only a few samples could be collected within unit 3a. as shown in fig.4, the deposition of unit 3 marks an important compositional change, from crystallinedominated to sedimentary-dominated. sedimentary clasts of south-alpine provenance (sandstones, limestones, siltstones, cherts, marlstones, rare conglomerates) are generally more abundant than 43%; sometimes their percentage is as high as 60%. the crystalline rock fragments are on the whole less than 30% (20% metamorphic, 10 % igneous, with the same composition already shown for unit 2). the abundance of the ubiquitous quartz fragments fluctuates between 10 and 20%. fig.4 shows that this sedimentary-dominated composition is also typical of units 4 and 5, with minor differences which can be hardly imputed to provenance variations rather than to hydraulic selection, differential alteration, mixing with recycled clasts from the older units and so on. radiocarbon dating of woody fragments from a peat sample, which was collected at the boundary between sub-units 3a and 3b, at one excavation site close to sordio (fig.2 and 3), allowed the determination of an age of 18.785+/-230 b.p for the top of sub-unit 3a. this date could be calibrated to 20.785 – 19909 cal bc (calib rev4.4.2; stuiver & reimer, 1993). 371aquifer architecture of... additional information is provided by stratigraphic position and cross-cut relations with the other units. subunit 3a is at least older than the quoted radiocarbon age; both sub-units 3a and 3b are cut by the terrace scarp that bounds unit 4, therefore they are older than unit 4 which is the most ancient unit within the lambro valley system. nevertheless, it cannot be excluded that flood deposits coeval with unit 4 veneer the oldest sediments of sub-unit 3b, close to the external margin of the lambro valley. unit 3 can be interpreted as the result of deposition within different palaeo-rivers, with moderate sinuosity and development of longitudinal sand bars (subunit 3a), or highly sinuous, meandering, with development of point bar channel abandonment sequences, with alluvial soils. flood plain fine sediments are locally associated with these depositional elements, and veneer the top of both the sub-units. the gravel composition shows the highest abundance of sedimentary clasts, testifying to provenance from local sources located in the southern alps foothills; the geometry and distribution of sedimentary bodies and of their abandoned traces suggests dispersion of detritus either by multiple streams or by an unstable river with frequent abandonment and avulsions cycles, which could have reached the end-moraines of the lecco brianza area to the north. unit 3 marks the time of definitive disappearance of distal alluvial fan – braided stream depositional systems from the study area, thus documenting the definitive northwards shift of the braided – meandering hinge. it also marks the first appearance of a clearly recognizable network of meandering streams, whose organisation is very close to the present day shape of the fluviatile network. unit 4 – ancient lambro depositional system unit 4 is the most ancient depositional unit of the lambro valley system, within which it is preserved only to the west of the present-day river. it is bounded to the west by the most external terrace scarp, which is less than 2 m in height, and to the east by the internal scarp, which is the highest (on average more than 12 m above the present day flood plain). the top boundary of unit 4 is a terrace surface, whose elevation does not correlate with any other terrace within the valley system, being comparable with the elevation of the sillaro and carpiano – bescapè abandoned streams. the lower boundary is observed locally and is interpreted in the subsurface cross-sections. it is a first order erosion surface cut into sub-unit 2c and 3. unit 4 shows a total maximum thickness of about 12 m. it consists of gravelly-sand and sand facies associations (tab.2), with minor fine grained layers and peat, which form fining upwards sequences. some exposures allow the observation of planar to trough, obliquelaminated sands and gravelly sands, associated upwards with rippled fine sands and mud or peat units. these correspond laterally to thin bedded and fine grained sand with small-scale trough cross-laminae which interbed with laminated silt and peat (tab. 2). some siltmud laminated or massive units contain gastropod and bivalve tests and show some intense burrowing. in the subsurface of the mairano area (fig. 3) borehole correlations allowed the reconstruction of a km-sized sand lens, with minor fine-grained layers at the top (fig. 5 and 6, section 11), which is truncated by a terrace scarp to the east. gravel composition of unit 4 is comparable to that of sub-unit 3b, and very close to that of sub-unit 3a (fig. 4): sedimentary lithoclasts are largely more abundant than crystalline rock fragments, which are often moderately to deeply weathered. no direct age determinations are available for unit 4. stratigraphic relationships indicate that it should be at least younger than 20.785 – 19909 cal bc, but this is only an approximation of its maximum age, as the timespan represented by sub-unit 3b could not be estimated yet. in any case unit 4 is cross-cut by the erosional lower boundary of sub-unit 5a. geometry of sedimentary bodies and facies association of unit 4 allow the interpretation of its fining upward sequence as the result of lateral accretion and sse migration of a channel point bar system, typical of a mixed load, meandering fluvial style. this is quite obviously confirmed by the relationships with the geomorphological features of the surface boundaries of this unit. unit 4 represents the oldest deposits of the lambro valley meandering system. as it has been previously stated, a time correlation with the sediments deposited into the meandering abandoned streams which are cut into the livello fondamentale outside the lambro terrace scarps, cannot be excluded. local provenance of sediments is documented by prevalence of sedimentary clasts within the gravel-sized facies; obvious mixing with second cycle clasts, eroded from the older alluvial succession and/or from the glacial deposits of the northern end-moraines, is witnessed by the presence of weathered crystalline clasts, which originated in the internal alps. unit 5 – post glacial lambro depositional system unit 5 is formed by the sediments which were deposited within the lambro valley system during its progressive entrenchment, to form three orders of terraced units, which are progressively lowered to the present day elevation of the lambro stream (about 15 m below the livello fondamentale). these terraces bound the top of three sub-units, 2 6 m thick, whose lower boundaries merge to form the 1st order surface that delimitates the lambro:valley system. as a rule this surface is marked by gravel lags or by a very typical concentration of mud clasts, sometimes as large as 80 cm. sub-unit 5a is preserved only on the eastern side of the present-day lambro; it is bounded by an erosion surface at the base, which truncates laterally and vertically unit 4, 3 and sub-unit 2c. sub-unit 5b, whose base truncates also sub-unit 5a (fig. 7), is preserved on both sides of the river at an intermediate elevation. sub-unit 5c is the present-day channel-bars-floodplains system of the lambro river. sub-units 5a and 5b are formed mostly by sands and gravels which are organised in flat lenses, tens to hundreds of meters in size, up to 6 m in height, with lateral accretion of fining upwards gravel-sand units (fig. 8a). the typical facies association of these lateral accreted lenses (tab. 2) includes a lower graded gravel bed, soled by a flat erosion surface and covered by coarse – middle, trough to planar, cross-laminated sand, which are followed by ripple cross-laminated fine sand and laminated to massive muddy silt. sometimes, 372 r. bersezio et al. sediments of unit 5. among the gravel fraction of subunit 5b, brick fragments and other artefacts are recurrent. these fragments are imbricated with the other clasts, documenting that they were caught-up by fluvial transport. age determination of unit 5 is based on several different evidences. the base of sub-unit 5a cross-cuts units 3 and 4, therefore it is at least younger than 20.785 – 19909 cal bc. the brick fragments that we found within 5b point bars indicate an historical age for sub-unit 5b. based on the typology of the recovered artefacts (cremaschi, pers. comm., 2003) a time span between the roman age and the renaissance has been recognised. sub-unit 5c is the recent – present-day depositional unit. based on this evidence we suggest 373 fig.7 gravel point bar (sub-unit 5a) laying over truncated , well-sorted grey sands of sub-unit 2c. lambro valley, outcrop o19 (fig. 3). barra di meandro a granulometria ghiaioso – sabbiosa (subunità 5a), ricoprente le sabbie grigie, ben selezionate della sub-unità 2c. affioramento o19 nella valle del lambro (ubicazione in fig. 3). fig.8 a) sub-unit 5b (domodossola, outcrop o19 of fig. 3; see also line-drawing in the lower insert of the same picture). lateral accretion of a sandy-gravelly point bar; note the flat surface at the top, covered by differently oriented sand mesoforms. total height is about 5 m (hammer on the left for scale). b) same location of picture (a): sub-unit 5b, historical point bar cut by chute channel; note the gravel lag and bar filling the chute channel, with an upwards fining sequence. spillover and flood plain fine grained deposits seal the bar-chute sequence. a) sub-unità 5b (domodossola, affioramento =19, fig. 3; confrontare con lo schizzo di fig.3). accrezione laterale di una barra di meandro sabbioso-ghiaiosa, delimitata a tetto da una superficie planare, coperta da mesoforme di fondo sabbiose a differente orientazione (altezza totale dello spaccato, circa 5 m; martello di scala sulla sinistra). b) stessa ubicazione di (a): subunità 5b, barra di meandro di età storica, troncata da canale di rotta con riempimento di ghiaie residuali e barre ghiaioso-sabbiose in sequenza fining-upwards. la successione è sigillata da sedimenti fini di esondazione. metres-thick, silty-clay and clay plugs are preserved at the top of the ε-cross stratified units. more frequently the same are cut by rounded scours, which are filled either by gravel-sand lags and bars, or plugged by sandy clay and peat (tab. 2; fig. 3; fig. 8b). the lateral accreted lenses are laterally juxtaposed and vertically superimposed on one another, by means of almost flat erosion surfaces (fig. 8a). recurrently they are separated by metres-thick fine grained units, formed by the association of laminated to massive silty-mud, with thin sand beds which can be graded, horizontal laminated or rippled (tab. 2). sub-unit 5c is represented by the present-day sediments of the lambro river, which are actively evolving. they include gravel-sand units, forming tens of meters long, 1 – 3 m high point bars, side bars, middle channel bars. gravel material is mostly recycled from the older units, as well as for the abundant mud clasts, which slide into the channel from the erosional shores. the present-day narrow flood plain is covered by rippled fine sand and silt to mud layers. some silty mud layers (spill-over deposits) are observed outside the “normal” flood plain (which is constrained within the terrace scarp between sub-unit 5b and 5c); these veneers are deposited above the terraces of sub-unit 5b and locally also above the terrace of unit 4, marking the highest levels reached by the exceptional floods (one of which occurred during the fall of 2000) in the narrowest sectors of the valley system. gravel composition of unit 5 is homogeneous and very similar to that of unit 4. sedimentary clasts are the most abundant (on average more than 50%); metamorphic (20% on average) and igneous (mostly granitoids; 10%) are subordinate; quartz fragments of different origin are, as usual, as abundant as about 20% of the total. most of crystalline fragments are variably weathered; differently the sedimentary clasts show very low to absent alteration. some peculiar lithologies, which occurred with very low abundances in the sediments of unit 3 (intermediate to acidic porhyrites and rhyiolites) or of unit 2 (green metabasites and serpentinites), are no longer observed within the gravel-size aquifer architecture of... that unit 5 represents the post-glacial (holocene) deposits of the lambro valley system. the interpretation of the depositional elements which form sub-units 5a and b is based on their facies assemblage, geometry, surface morphology and relationships with the shape and fluvial style of the lambro valley system. the lateral accreted units are directly recognised as point-bar deposits, with a partially preserved shape. chute channels are cut into these pointbars. they are filled by gravelly-sand bars and silt-clay plugs. the fine grained sediment facies associations with sand lenses (tab. 2) are interpreted as typical flood-plain crevasse splay deposits. finally, the sandmud lens-shaped units, with peat, are recognised as typical channel abandonment sequences, with deposition within oxbow lakes. these interpretations are confirmed by the depositional processes and facies which have been described for the present-day sub-unit 5c. gravel petrography supports the interpretation of local provenance of detritus, both from the oldest alluvial and glacial sediments, and from the mesozoic rocks which are at present under erosion in the south-alpine foothills of the brianza, which are the source areas of the holocene lambro river. 5 discussion 5.1 stratigraphy the five informal units defined above can be compared to the stratigraphic framework of the po plain quaternary succession, both based on physical stratigraphy and on time equivalences. for clarity they will be re-examined in descending stratigraphic order, from the youngest unit 5 to the oldest unit 1. unit 5 represents the most recent depositional unit, confined within the lambro valley system, which formed during its recent entrenchment below the livello fondamentale. based on stratigraphic relationships, age determinations and fluvial style, it can be attributed to a post-glacial, holocene age. therefore, it is equivalent to the post glacial unit of the northern sectors of the po plain (bini et al., in press). the correlation with regional stratigraphy of unit 4 is affected by some incertitude. it is confined within the lambro valley system, and its age is constrained by the minimum age of unit 3a (20.785 – 19909 cal bc) and the maximum age of unit 5b (historical). it could therefore be attributed both to the latest pleistocene and to the holocene. in the latter case it should be included into the post glacial unit together with unit 5. unit 3 represents the depositional systems which build the morphological surface of the livello fondamentale, outside the terraces of the lambro valley system. it is constrained in age by the youngest age available for sub-unit 2c (22.035+/-300 a bp ) and the age of the boundary between sub-units 3a and 3b (20.785 – 19909 cal bc). in addition to these data, the stratigraphic position, gravel composition and depositional style suggest a correlation with the alluvial units which were deposited during the waning time of l.g.m. (crowley & north, 1991; bini et al., in press). in this case we could suggest a correlation with the deposits of the alloformazione di cantù, which have been recognised within the entrenched valleys to the north of the study area by strini (2001). as no physical correlation is available yet between the two areas, we consider this interpretation as a working hypothesis for ongoing studies. unit 2 represents the coarsest grained unit of the lambro area; the composition of its gravels is dominated by alpine-sourced clasts, with a strong fingerprint of provenance from the metamorphic basements of southern and northern alps. the age of the uppermost sub-unit 2c is constrained within 24.620+/-160 a bp and 22.035+/-300 a bp, but no constraints are available for the lowermost sub-unit 2a. these data indicate a minimum late pleistocene age for unit 2. in addition we can also consider that, based on regional dip of stratigraphic units, unit 2 should be at the surface to the north of the study area. in this area, a sand-gravel unit with a comparable gravel composition, represents the shallowest stratigraphic unit, bounded by the topographic surface. by physical correlations, strini (2001) was able to include this unit into the besnate allogroup (da rold, 1990; bini, 1997a; b). this allogroup is formed by several glacial, glacio-fluvial and alluvial units, which form at least 5 alloformations related to different glaciations (bini, 1997a). therefore we suggest that the three sub-units which form unit 2 can be correlated with the besnate allogroup of the pedealpine area. however, we cannot exclude alternative correlations for sub-unit 2a, which could also represent a glacio-fluvial succession , correlative to a pre-besnate glaciation. the stratigraphic correlation of unit 1 is highly uncertain, because we have neither physical correlations, nor age determinations. unit 1 has been deeply eroded by the lower boundary of unit 2, and is characterised by a mostly fine-grained facies association, that we interpreted as a distal, meandering fluvial succession. this advises against interpreting this unit as a glacio-fluvial succession linked to a pre-besnate glacial advance. actually, in the most conservative hypothesis, it could represent an ancient post-glacial unit, of prebesnate age; otherwise it could also represent a preglacial unit. this second hypothesis would imply an age older than middle pleistocene (penk & bruckner, 1909; kukla & cilek, 1996), which is not supported, at present, by any circumstantial evidence. 5.2 sedimentary evolution the lambro area is a part of the alluvial plain which developed during middle – late pleistocene between the south-alpine and apenninic thrust fronts. the depositional style of filling of this former pliocene – early pleistocene marine area has been controlled principally by northwards propagation of the apennine frontal thrusts (salerano and san colombano ramp anticlines; pieri & groppi, 1981; bersezio et al., 2001; fantoni et al. 2003, with references therein), uplift on the alpine side (arca & beretta, 1985), onset and dynamics of glaciations (since the middle pleistocene; penk & bruckner, 1909; bini, 1997a with references therein), dynamic of the regional base-level and erosion-deposition hinge. the succession that we could investigate developed in an alluvial environment, built by the coalescent deltas of transversal alpine rivers and palaeo-po axial system, when the coast-line was already far away, to 374 r. bersezio et al. the east of the study site (dondi & d’andrea, 1986, regione lombardia – eni, 2002). in fact no indications of marine influence has been found in the deepest succession that we studied (unit 1). this succession resulted from two steps of se-wards migration of a meandering river depositional system (tab. 2), which are separated by an avulsion or a marked retrogression step, documented by the widespread diffusion of flood-plain and palustrine fine-grained sediments. whether this was due to tectonic control by uplift increments of the salerano – san colombano anticlines (“forced regression” concept of regione lombardia – eni, 2002) or to the response to glacial pulses of a pre-besnate glaciation, or to a combination of the two, cannot be stated with the presently available data. a subsequent, late pleistocene, north-westwards shift of the erosion-deposition hinge, is witnessed by the development of the deep erosion surface that soles unit 2, at the onset of the besnate glaciations (bini, 1997a, b). the kriged, plan and 3d view of this surface is portrayed in fig. 9 (lower maps). this unit documents two major south-eastwards progradation increments of distal, braided alluvial fans, fed from southand northalpine sources. during both steps, the transition to a southern fluvial plain is recorded in the centre of the studied area. the position of the south-eastern fan boundary is clearly recognised in fig.9, by a marked downward step of the 2a – 1b boundary, together with the channel like shape of the same erosion surface more south-eastwards. the mildly erosional base of sub-unit 2c, which mimics the original shape of the top of the alluvial fan sub-unit 2b, is shown in the same picture, that allows the appreciation of the marked southeastwards shift of the southern fan boundary, fringing to a fluvial plain system. a direct control from the major late pleistocene glaciations can be suggested for these dynamics, linking basal erosion and subsequent progradation of the three coarse-grained depositional systems with the onset and evolution of a glacial stage of the besnate. the fine-grained deposits of the retrogression stage at the top of unit 2a was poorly developed or incompletely preserved. differently sub-unit 2c, which is dated between the non-calibrated dates of 22.000 and 24.000 a bp, documents almost entirely the latest cycle of the besnate, with a widely preserved fine-grained fluvial unit at the top. a new regional erosion surface heralds the southwards migration of the sandy braid-plain meandering river depositional system (unit 3) that developed during the l.g.m. glaciation. the time bracket that is identified by radiocarbon dates (22.000 – 19.900 a bp) for deposition of sub-unit 3a, allows for correlation with the isotope stage 2 (martinson et al., 1987). this is in good agreement with the gravel-sand depositional style of this unit, which differs from the overlaying meandering systems of sub-unit 3b, that could correlate with a glacial retreat. at this time the entire study area was located south of the braid-plain/meandering hinge, as it is portrayed by the map of the lower boundary of subunit 3b (fig. 9), which shows several entrenched and sinuous scours, cross-cutting to one another. the post-glacial evolution is recorded by the entrenched meandering depositional systems of the lambro valley system (units 4 and 5). their deepening was very fast, and high erosion rates lasted up to historical times, if we consider that the top of the “renaissance age” l.s. point bars of sub-unit 5b is about 6 m above the top of the present-day bars of the lambro river. this is related to the dynamics of the local baselevel (po river), and could be triggered by the ongoing slow uplift of the apennine structures. 5.3 hydrostratigraphy and bearings on hydrogeologic modelling the previous reconstruction of stratigraphic architecture provides the base for the definition of aquifer stratigraphy of the lambro area, valid for a thickness of about 100 m. this can be visualised with the aid of the cross-sections in figs. 5-6 and of the plan view of the kriged boundaries of the most relevant units (fig. 9). the distribution and connectivity of the gravel – sand intervals vs. thickness, complexity and continuity of the fine-grained units, defines the aquifer organisation of this succession. taking into account the basic definition of hydrostratigraphic units (maxey, 1964; anderson, 1997 with references therein) it is possible to identify three aquifer units (in ascending order: lower sub-unit 1a; sub-units 1b-2a-2b-lower 2c; units 3-45), which are discontinuously separated by two aquitards (upper sub-unit 1a; upper sub-unit 2c). the separation between aquifers is very poor in the northern sector of the study area, where the sand: gravel units merge due to erosion and/or non-deposition of the fine grained layers at their base (fig. 5 and fig. 6). we do not propose any label for these hydrostratigraphic units, because aquifer classification is already sufficiently confused in literature (martinis & mazzarella, 1971; avanzini et al.,1995; francani, 2001; regione lombardia – eni, 2002). we shall refer to them respectively as “lowermost”, “intermediate” and “uppermost” aquifer, being aware of their local significance, which is restricted to the study area. the lowermost aquifer is mostly sandy and shows internal complexity, due to southwards fringing of the sand-bodies, which alternate with silt-mud, flood plain intervals. the aquitard at its top is represented by the widespread flood plain muddy unit that tops the finingupwards sequence 1b. although it is locally truncated northwards (fig. 9, maps of base 2a), it seems to represent an efficient confining layer at the scale of the study area. the intermediate aquifer is the coarsest and thickest one. it corresponds to the lower part of the “aquifero tradizionale” (auct.), and possibly could belong to aquifer group a (?) of regione lombardia – eni (2002). it is formed by gravel-sand bodies, which are interconnected to the north due to the development of the regional erosion surface that soles unit 2 and of the sharp progradation surface of sub-unit 2b above 2a. southwards these coarse-grained bodies fringe out, due to transition from braided alluvial style, to meandering fluvial deposition, with development of flood plainoxbow lake-channel abandonment fine-grained deposits. seemingly, the retrogradation of the 2b gravel-sand body determined the development of a general upwards fining succession, whose sand – mud alternations form the overlaying complex aquitard. the efficiency of the latter is strongly affected by erosion of sub-unit 2c to the north and east (figs. 5, 6 and 9), that determines the connection with the uppermost aquifer, and locally with the topographic surface (lambro valley system, 375aquifer architecture of... 376 fi g. 9 k rig ed is ob at hs (r ig ht ) a nd 3 d v ie w (l ef t) of t he lo w er b ou nd ar ie s of s ub -u ni ts 2 a , 2c , 3 an d o f th e p re se nt -d ay t op og ra p hy . a t th e ex tr em e rig ht , th e is op ac h m ap s of s ub -u ni ts 2 a -b an d 2 c a re r ep re se nt ed . th e m ap s sh ow t he b as al s co ur in g of t he a q ui fe r un its in to t he f in egr ai ne d a q ui ta rd s, c um ul at iv e th ic kn es s of t he m os t im p or ta nt a q ui fe r (s ub -u ni ts 2 a a nd b ) a nd th e p os tgl ac ia l e nt re nc hm en t of t he l am b ro v al le y sy st em . m ap p e d el le is ob at e e vi si on e 3d d ei li m iti in fe rio ri d el le s ub -u ni tà 2 a , 2 c e 3 ; i n al to è r ip or ta ta la r ic os tr uz io ne d el la t op og ra fia . l e m ap p e so no o tt en ut e p er k rig in g d el le s up er fic i i nd ic at e. a d es tr a so no r ap p re se nt at e le m ap p e d i i so p ac he d el le s ub -u ni tà 2 a -2 b e 2 c . l e m ap p e ill us tr an o l’e ro si on e al la b as e d eg li ac q ui fe ri p rin ci p al i, ap p ro fo nd iti a ll’ in te rn o d ei r el at iv i a cq ui ta rd i, lo sp es so re d el l’a cq ui fe ro in te rm ed io (2 a b ) e l’ ap p ro fo nd im en to p os tgl ac ia le d el s is te m a va lli vo d el l am b ro . r. bersezio et al. fig. 9 uppermost map). therefore, the intermediate aquifer is a multi-pay, partly confined aquifer unit, whose separation from the surface waters is not completely ensured throughout the study area. however, its bulk recharge should be looked for also northwards of the same area, where the top of the besnate allogroup is close to the surface (strini, 2001). the uppermost aquifer is the phreatic one and includes the non-saturated zone at its top. the recent regional piezometric maps (francani, 2001) indicate that the water table-top fluctuates between 5 and 10 m below the topographic surface. field observations of excavations, quarries, borehole drillings and terrace scarps, indicate that temporary and local water nappes are contained at least up to a depth of 2 m below the surface. this is confirmed by semi-permanent historical water sources which are aligned on the scarps of the major terrace of the lambro river. these ground waters are only intermittently and locally in contact with the lambro river waters. these observations are clearly justified by the organisation in minor fining upwards sequences of sub-unit 3b, with flood plain fines which act to compartment ground waters within the phreatic nappe. below the upper part of this unit, there is a good potential interconnection among the gravel-sand lenses of units 3a and 4, as far as they are juxtaposed by deep erosion surfaces. this observation holds also for the relations with the intermediate aquifer, which is truncated at the top by the lower erosional boundary of the lambro valley system (fig. 6). in fact the uppermost aquifer is deeply dissected by the lambro terrace scarps (fig. 9, left). the top of the uppermost aquifer is only poorly protected by sandy soils (brenna, 2002), therefore this unit acts like a vertical filtration zone recharging this shallow aquifer and contributing to the recharge of the intermediate one. 6 conclusions aquifer stratigraphy and architecture of the upper pleistocene succession of the lambro valley area, south of milan, has been built by the dynamics of alpine-fed, alluvial depositional systems. the hydrostratigraphic complexity is determined by: • the late pleistocene, glacial controlled, erosion progradation – retrogression cycles, that determined the repetitive stacking of gravel/sand, fining upwards sequences (most permeable aquifers), topped by widespread, fine-grained, least permeable units (aquitards); • the erosional entrenchment of depositional systems, controlled by the dynamics of the erosion – aggradation hinge under the influence of climatic cycles and local uplift of the salerano – san colombano ramp anticlines, that shaped the connectivity of the most permeable bodies; • the nw – se transition from distal alluvial fan/braid plain to meandering fluvial/flood plain depositional systems, that occurs in the centre of the studied area. the lowermost aquifer (sub-unit 1a) is a multi-pay, confined unit, presumably developed during an interglacial period of pre-besnate age. it is partly sealed by alluvial plain fines (top of 1a). the intermediate aquifer (sub-units 1b, 2a, 2b, lower 2c) corresponds to the traditional aquifer auct. and to part of aquifer group a (regione lombardia – eni, 2002), and includes a pre-besnate sand – gravel unit and the alluvial depositional systems equivalent to the besnate. it is a multi-pay unit, formed by stacked cycles of advancement and retreat of distal alluvial fan/braid plain, only partly confined at the top by the retrogradational fines of the upper part of sub-unit 2c. it is recharged in the area of northern emergence of the besnate allogroup and locally by the surface waters, including the strongly compromised lambro river waters. the uppermost aquifer includes the phreatic/non saturated zone and is formed by the braid-plain to meandering depositional system (unit 3) which correlates with the l.g.m. in the study area; it is in full contact with the post glacial to historical meandering depositional system of the lambro valley (units 4 and 5). it is only poorly protected by discontinuous flood plain fines and by mostly sandy surface soils. acknowledgements this work was supported by cnr – idpa and first/2001 funds to rb. the authors thank the editorial board for review of the paper which was also useful to ameliorate the english form. references alfano l. & mancuso m. (1996) sull’applicabilità del metodo dipolo-polare continuo nelle ricerche idriche a media profondità in aree di pianura acque sotterranee, xiii, 2/50, pp. 61-71. anderson m. p. (1997) characterization of geological heterogeneity, in subsurface flow and transport: a stochastic approach – in: dagan g. & s.p. neuman, eds., pp. 23-43, cambridge univ. press. arca s. & beretta g.p. (1985) prima sintesi geodetico-geologica sui movimenti verticali del suolo nell’italia settentrionale (1897 – 1957) boll. geodesia e scienze affini, 44/2, pp. 125 – 156. ariati l., cotta ramusino s. & g.f. peloso (1988) la struttura del colle di san colombano al lambro: riflessi idrogeologici e caratteristiche chimiche della falda freatica. in: p. casati (ed.), acque sotterranee di lombardia, caratterizzazione chimica ed inquinamento. cnr milano, pp. 97-114. avanzini m., beretta g.p., francani v. & m. nespoli (1995) indagine preliminare sull’uso sostenibile delle falde profonde nella provincia di milano cap, milano, consorzio acqua potabile, 1995. bersezio r. (1986) studio fotogeologico e geofisico per la ricostruzione dell’andamento degli antichi alvei: prima ricostruzione dei paleoalvei della pianura fra adda e ticino studi idrogeologici sulla pianura padana, (clup, milano), 2, pp. 3.1-3.25. bersezio r., fantoni r. & pessina c. (2001) l’assetto strutturale del margine sudalpino-padano: contributo alla conoscenza del sottosuolo nel settore bergamasco geol. insubr., 6/1, pp. 81-93. bini a. (1997a) problems and methodologies in the study of the quaternary deposits of the southern 377aquifer architecture of... side of the alps geol. ins., 2/2, pp. 11 – 20, lugano. bini a. (1997b) stratigraphy, chronology and palaeogeography of quaternary deposits of the area between the ticino and olona rivers (italy switzerland) geol. ins., 2/2, pp. 21-46. bini a., borsato a., carraro f., carton a., corbari d., cucato m., monegato g. and pellegrini g.b. (in press) definizione di alcuni termini in uso nella cartografia dei depositi quaternari continentali in ambito alpin il quaternario, in press, roma. bini a., strini a. & zuccoli l. (2004) geologia di sottosuolo di un settore dell’alta pianura a nord – est di milano il quaternario, this volume.. roma. brenna s. (2002) capacità protettiva dei suoli nei confronti delle acque sotterranee in: regione lombardia eni-divisione agip, geologia degli acquiferi padani della regione lombardia, 113115, s.el.ca. (firenze). cassano e., anelli l., fichera r. & v. cappelli (1986): pianura padana. interpretazione integrata di dati geofisici e geologici 73° congr. soc. geol. it., 29 sett-4 ott. 1986, roma, 27 pp. castiglioni g.b. et al. (1999) carta geomorfologica della pianura padana, scala 1:250000. ministero università ricerca scientifica tecnologica, selca (firenze). castiglioni g.b. & g.b. pellegrini (2001) note illustrative della carta geomorfologica della pianura padana. suppl. geogr. fis. dinam. quat., iv, 207 pp. crowley t.j. & north g.r. (1991) paleoclimatology oxford university press, 339 pp. da rold o. (1990) l’apparato glaciale del lago maggiore, settore orientale. ph.d. thesis, 200 pp., university of milan. desio a. (1965) i rilievi isolati della pianura lombarda ed i movimenti tettonici del quaternario rend. ist. lomb. acc. sci.lett., 99, pp. 881-894. dondi l. & d’andrea m.g. (1986) la pianura padana e veneta dall’oligocene superiore al pleistocene giornale di geologia, serie iii, 48, (1-2), pp. 197 – 225, bologna. fantoni r., massari f., minervini m., rogledi s. & rossi m. (2001) il messiniano del margine sudalpino lombardo: relazioni tra contesto strutturale e stratigrafico deposizionale geol. ins., 6/1, pp. 95-108. lugano. fantoni r., bersezio r. &. forcella f. (2003) alpine structure and deformation chronology at the southern alps po plain border in lombardy boll soc. geol. it., in press. francani v. (2001) acque sotterranee in lombardia, gestione sostenibile di una risorsa strategica. regione lombardia, risorse idriche e servizi di pubblica utilità, 109 pp. huggenberger p. & aigner t. (1999) introduction to the special issue on aquifer sedimentology: problems, perspectives and modern approaches sedimentary geology, 129, pp. 3-4, 179 – 187. kukla g. & cilekv. (1996) plio–pleistocene megacycles: record of cl imate and tectonics palaeogeography, palaeoclimatology, palaeoecology, 120, pp. 171–194. laubscher h.p. (1985) large scale, thin-skinned thrusting in the southern alps: kinematic models geol. soc. am. bull., 96, pp. 710-718. marchetti m. (2001) fluvial, fluvioglacial and lacustrine forms and deposits . in: castiglioni g.b. & pellegrini g.b. (eds.), note illustrative della carta geomorfologica della pianura padana. suppl. geogr. fis. dinam. quat., iv, pp. 73-99. martinis b. & mazzarella s. (1971) prima ricerca idrica profonda nella pianura lombarda mem. ist. geol. min. univ. padova, vol.xxviii, padova. martinson d.g., pisias n.g., hayes j.d., imbrie j., moore t.c., shackleton n.j. (1987) age dating and the orbital theory of the ice ages: development of a high –resolution zero to 300.000 years chronostratigraphy quaternary research, 27, pp. 1-29. matheron g. (1969) le krigeage universel cahiers du centre de morphologie mathematique, ecole des mines de paris, fasc. 1, 83 pp., fontainebleau. maxey g.b. (1964) hydrostratigraphic units journal of hydrology, 2, pp. 124 129 miall a.d. (1996) the geology of fluvial deposits springer verlag, 582 pp. berlin muttoni g., carcano c., garzanti e., ghielmi m., piccin a., pini r., rogledi s. and sciunnach d. (2003) onset of major pleistocene glaciations in the alps geology, 31/11; pp. 989–992; nacsn, north american commission on stratigraphic nomenclature (1983) north american stratigraphic code aapg bull., 67, 841 – 875. penk a. & bruckner e. (1909) die alpen im eiszeitalter bd.3, pp. 772 – 789, leipzig. pieri m. & g. groppi (1981) subsurface geological structure of the po plain, italy. cnr, pubbl. 411, progetto finalizzato geodinamica, 13 pp. regione lombardia & eni-divisione agip (2002) geologia degli acquiferi padani della regione lombardia, relazione tecnica 130 pp., s.el.ca. (firenze). salvador l. (1987) unconformity bounded stratigraphic units geol. soc amer. bull., 98, pp. 232 – 237. strini a. (2001) gli occhi pollini della brianza orientale: genesi ed evoluzione del fenomeno nel quadro geologico regionale. tesi di dottorato inedita, xiii ciclo, università di milano, 550 pp. stuiver m. & reimer p.j. (1993) radiocarbon calibration program calib rev4 4.2 radiocarbon, 35, pp. 215 – 230. tellini c. & l. pellegrini (2001) forme di origine tettonica in: castiglioni g.b. & pellegrini g.b. (eds.), note illustrative della carta geomorfologica della pianura padana. suppl. geogr. fis. dinam. quat., iv, pp. 55-68. veggiani a. (1982) variazioni climatiche e dissesti idrogeologici dell’alto medioevo in lombardia e la rifondazione di lodi sibrium, 16, pp. 199 – 208, lodi. 378 ms. ricevuto l’11 maggio 2004 testo definitivo ricevuto il 16 novembre 2004 ms. received: may 11, 2004 final text received: november 16, 2004. r. bersezio et al. sess 1_160211.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 luminescence chronology of pleistocene marine terraces of the sicily and calabria coastal areas gloria maria ristuccia1,2, anna maria gueli2, carmelo monaco1 giuseppe stella2 & sebastiano olindo troja2 1dipartimento di scienze geologiche, università di catania, italy 2ph3dra laboratory, dipartimento di fisica e astronomia, università di catania & infn catania, italy corresponding author: g.m. ristuccia <gloria.ristuccia@ct.infn.it> abstract: ristuccia g.m. et al., luminescence chronology of pleistocene marine terraces of the sicily and calabria coastal areas. (it issn 0394-3356, 2011) the calabrian arc and north-eastern sicily are sectors of central mediterranean where the effects of quaternary tectonics are visible and regional uplift is accompanied by marine terracing along the coastal areas. in this paper, the application of optically stimulated luminescence (osl) dating based on the single-aliquot regenerative-dose (sar) protocol for sand-sized quartz is investigated. we present new osl age estimates of pleistocene marine terrace deposits located in capo vaticano peninsula and in the sant’agata di militello costal area, where a complete series, characterized by both marine and continental deposits, occurs. current elevations of marine terraces also suggest that these portions of the calabrian arc have been affected by a vigorous tectonic uplift during the last 330 ka, probably due to sum of regional uplift and fault activity. riassunto: ristuccia g.m. et al., cronologia tramite luminescenza dei terrazzi marini pleistocenici presenti lungo l’area costale della sicilia e della calabria meridionale. (it issn 0394-3356, 2011) l’arco calabro e la sicilia nord-orientale sono settori del mediterraneo centrale dove gli effetti della tettonica quaternaria sono ben visibili e il sollevamento regionale è evidenziato da un terrazzamento marino lungo le aree costiere. in questo lavoro è stata investigata la possibilità di datare i depositi terrazzati tramite la luminescenza otticamente stimolata (osl) mediante il protocollo della singola aliquota (sar) su quarzo estratto dai sedimenti. i risultati ottenuti hanno permesso di ottenere nuove cronologie dei terrazzi pleistocenici localizzati lungo la penisola di capo vaticano e l’area costiera di sant’agata di militello. le attuali linee di costa suggeriscono, insieme ai dati ottenuti, che queste porzioni dell’arco calabro sono state soggette ad un forte sollevamento durante gli ultimi 330 ka, probabilmente a causa della componente regionale sommata ad attività di faglie. key words: marine terraces, uplift rate, luminescence parole chiave: terrazzi marini, rate di sollevamento, luminescenza 1. introduction marine terraces are geomorphic surfaces that have been exposed by a lowering of sea level or a tectonic uplift; their inner edges indicate the location of a palaeoshoreline. therefore the timing of terrace formation can provide information on coastal uplift and allows to determine local deformation related active faulting. in this paper we investigate the middle-upper pleistocene deformation rates of some terraces of the sicily and calabria coastal areas (capo vaticano, western calabria; sant’agata di militello, northern sicily). in these southern italy regions, the effects of intense quaternary tectonic activity were evident. at first, the marine surfaces, with their relative inner edges, have been mapped using 1:25000 scale topographic maps of the igm integrated with analysis of 1:33000 and 1:10000 scale aerial photographs. moreover, osl dating of marine terraces deposits, together with detailed morpho-structural analysis of tectonic elements, allowed us to reconstruct the tectonic evolution of analyzed coastal area and to constrain the relationships between marine terracing and normal faulting in a precise time range. 2. geological setting the capo vaticano peninsula is a structural high located along the tyrrhenian side of the calabrian arc (fig. 1), an arc-shaped portion of the central mediterranean orogen extruded towards the oceanic crust of the ionian basin during the final stage of the africa-europe collision (malinverno & ryan, 1986). late quaternary tectonics along the calabrian arc are characterized by the occurrence of a prominent normal fault belt along the western side of calabria and ne coast of sicily, developed in response to wnw,ese regional extension (siculo-calabrian rift zone; monaco & tortorici, 2000). since the middle pleistocene, extensional tectonics have been coupled with a strong regional uplifting which developed spectacular flights of marine terraces (westaway, 1993; ghisetti, 1981; 1984; miyauchi et al., 1994; bianca et al., 1999; catalano & de guidi, 2003; tortorici et al., 2003; valensise & pantosti, 1992; ferranti et al., 2006). 54 56 55 the sant’agata di militello coastal area is located along the tyrrhenian shore of ne sicily about 100 km west of the town of messina. the area is a part of the southernmost sector of the calabrian arc. the samples from each marine terrace (seven samples from capo vaticano peninsula and three from sant’agata di militello) were collected from 60 cm long cylindrical cores (5 cm) extracted from fresh outcrops by black corebarrel to dating by optically stimulated luminescence (osl) methodology. the ends of each cylinder were sealed with black tape for transportation because it is of critical importance for osl measurements that the samples are not exposed to daylight. however, the outer layers have been used in the laboratory for radioactivity measurements and water content determination. 3. methodology osl has become an important technique for studying earth surface processes and dating sediments. the general equation used to determine the age, time from the last optical bleaching until today, is: where the equivalent dose (ed) is the total dose absorbed from instant zero until the moment of measurement in the laboratory, while the annual dose (ad) is the average energy absorbed for unit mass by the specimen in one year as the result of the radioactivity present both in the specimen itself and in the environment. in the present work, the experimental values of ed were determined using the single aliquot regeneration protocol (sar) (murray & wintle a. g., 2000; 2003) coupled with )/( )()( kagydoseannual gydoseequivalentaage = coarse grain sample preparation technique (bianca et al., 2010). the coarse grain fraction consists in hf etched quartz grains within the size range 100-300 μm that were extracted from the sediment using standard separation procedures. the purity of quartz fraction was verified by infrared stimulation on some representative aliquots for each sample (aitken, 1998). the age is calculated as outlined in equation: age = ed/(f·dβ+dγ+cosm) where f is the attenuation factor depending on grain size (mejdahl, 1979); dβ contribution was calculated using concentration values of u, th and k determined by the icp-ms technique. to determine beta and gamma dose rates, annual dose conversion factors by adamiec & aitken (1998) were used. these dose rates were validated from a comparison with gamma dose measured in situ at the sampling points with a portable nai(tl) probe. the contribution of cosmic radiation to the total dose-rate was calculated using present depth (prescott & hutton, 1988; 1994) considering the density and the depth of the sample below the surface. the moisture-corrected dose-rates values are obtained considering the present-day water content from win-situ values (aitken, 1998) using the attenuation factors given by zimmerman (1971). 4. results and conclusions absolute dating of middle-upper pleistocene marine sediments by osl methodology yielded new constraints for correlating the seven orders of marine terraces exposed in the capo vaticano peninsula with the last quaternary interglacial stages. in fact, the distinct marine terraces can be correlated with the last seven high-stands of the global fig. 1, regional tectonic map of the southern part of the calabrian arc carta tettonica regionale della porzione meridionale dell’arco calabro luminescence chronology of pleistocene marine ... 56 ms. received: testo ricevuto il eustatic curve (mis 7.5, 7.3, 7.1, 5.5, 5.3, 5.1 and 3.3). present marine terrace elevations also suggest that this portion of calabrian arc has been affected by a vigorous tectonic uplift during the last 236 ka, locally characterized by rates up to ~2 mm/ a, responsible for the preservation of all marine terraces related to the entire series of the last major sea level high-stands. moreover, the geometry of the palaeoshorelines indicates that the raising process was characterised by uplift rates increasing toward the sw, resulting in the tilting of the whole peninsula toward the ne. it represents the footwall of both the sw,ne and the wnw,ese striking onshore and/or offshore normal fault systems. consequently, the uplifting of the area, started just before 236 ka ago, can be considered to represent the sum of the activity of these fault segments and the regional uplift. in the ne sector of sicily, between acquedolci and sant’agata di militello, the estimated rates highlight a constant uplifting of 0.7-0.8 mm/a during the last 330 ka. instead, between sant’agata di militello and capo d’orlando, the uplifting is not constant, probably due to the activity of the capo d’orlando fault. by comparing the uplift rates along crosssections through the ne sector, where the capo d’orlando fault occurs, and the sw sector, where it ends, terraces i, ii and iii, laying on the hanging wall of the fault, raised at a slower rate (0.35 mm/ a) than the terraces located in the sw sector. in the same way, the terraces iv and v, laying on the footwall of fault, raised at a faster rate (0.92 mm/a) than the sw terraces (orioli et al., 2011, in preparation). in conclusion, the morphological analysis of the marine terraces and the deformation pattern confirm the occurrence of an important tectonic component in the total amount of uplift, which is related to the middle-upper pleistocene activity of normal faults. references adamiec g. & aitken m.j. (1998) dose-rate conversion factors: update. ancient tl, 16, 37-50. aitken m.j. (1998) an introduction to optical dating. the dating of quaternary sediments by the use of photon-stimulated luminescence. oxford science publications, 267. bianca m., monaco c., tortorici l. & cernobori l. (1999) quaternary normal faulting in southeastern sicily (italy): a seismic source for the 1693 large earthquake. geophysical journal international, 139, 370394. bianca m., catalano s., de guidi g., gueli ,a.m., monaco c., ristuccia g.m., stella g., tortorici g., tortorici l. & troja s.o. (2010) luminescence chronology of pleistocene marine terraces of capo vaticano peninsula (calabria, southern italy). quaternary international, doi: 10.1016 / j.quaint.2010.07.013, in press. ferranti l., antonioli f., mauz b., amorosi a., dai pra g., mastronuzzi g., monaco c., orrù p., pappalardo m., radtke u., renda p., romano p., sansò’ p. & verrubbi v. (2006) markers of the last interglacial sea-level high stand along the coast of italy: tectonic implications. quaternary international, 145-146, 30-54. ghisetti f. (1981) upper pliocene-pleistocene uplift rates as indicators of neotectonic pattern: an example from southern calabria (italy). zeitschrift fur geomorphologie, 40, 93-118. ghisetti f (1984) recent deformations and the seismogenic source in the messina straits (southern italy). tectonophysic, 109, 191-208. malinverno a. & ryan w.b.f. (1986) extension in the tyrrhenian sea and shortening in the apennines as a result of arc migration driven by sinking of the lithosphere. tectonics, 5, 227-245. mejdahl v. (1979) thermoluminescence dating: betadose attenuation in quartz grains. archaeometry, 21, 61-72. miyauchi t., dai pra g. & labini s. (1994) geochronology of pleistocene marine terraces and regional tectonics in the tyrrhenian coast of south calabria, italy. il quaternario, 7, 17-34. monaco c. & tortorici l. (2000) active faulting in the calabrian arc and eastern sicily. journal of geodynamics, 29, 407-424. murray a. s. & wintle a. g. (2000) luminescence dating of quartz using an improved single-aliquot regenerative-dose protocol. radiation measurements, 32, pp.57-73. murray a. s. & wintle a. g. (2003) the single aliquot regenerative dose protocol: potential for improvements in reliability. radiation measurements, 37, 377-381. prescott j.r. & hutton j.t. (1988) cosmic ray and gamma ray dosimetry for tl and esr. nuclear tracks radiation measurements, 14 (1/2), 223-227. orioli s., ristuccia g.m., monaco c., giunta g., gueli a.m., stella g. & troja s.o. (2011) marine terracing and fault activity in the sant’agata di militello coastal area (north-eastern sicily) during the middle-late pleistocene, in preparation. prescott j.r. & hutton j.t. (1994) cosmic ray contributions to dose-rates for luminescence and esr dating: large depths and long terms time variations. radiation measurements, 23, 497-500. tortorici g., bianca m., de guidi g., monaco c. & tortorici l. (2003) fault activity and marine terracing in the capo vaticano area (southern calabria) during the middle-late quaternary. quaternary international, 101-102, 269-278. valensise g. & pantosti d. (1992) a 125 kyr-long of geological record of seismic source repeatability: the m.s.s (southern italy) and the 1908 earthquake (ms 7 1/2). terra nova, 4, 472-483. westaway r. (1993) quaternary uplift of southern italy. journal of geophysical research, 98, 2174121772. zimmerman d.w. & huxtable j. (1971) thermoluminescent dating of upper palaeolithic fired clay from dolnì vĕstonice. archaeometry, 13, 53-57. g.m. ristuccia et al. january 13, 2011 13 gennaio 2011 il quaternario fta/ian journal of quaternary sciences 24, (abstract algua, roma 02/2011), 114116 congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 calibration of osl data: mismatch between stratigraphy ano osl chronology of sediments from the po plain laura panzeri', lrene zembo2 , riccardo bersezio2 & marco martini1 1 dipartimento di scienza dei materiali, università di milano bicocca, milano 2 dipartimento di scienze della terra, università degli studi di milano, milano corresponding author: l. panzeri <laura.panzeri@mater.unimib.it> abstract: panzeri l. et al., calibration of osl data: mismatch between strat1ghraphy an d osl chronology of sediments tram po plain. (it issn 0394-3356, 2011) we present the results obtained with optically stimulated luminescence (osl) on alluvial sediments from po plain. the ages obtained are in good agreement with stratighraphic position and with radiocarbon ages for the younger samples (latest pleistocene) while there is an underestimation for the oldest samples (middle pleistocene). the cause of this behaviour is discussed. riassunto: panzeri l. et al., calibrazione di date ottenute mediante osl: disaccordo tra la stratigrafia e la cronologia osl di sedimenti della pianura padana. (it issn 0394-3356, 2011) vengono presentati i risultati ottenuti mediante luminescenza otticamente stimolata (osl) applicata a sedimenti alluvionali provenienti dalla pianura padana. le età ottenute sono in accordo con la posizione stratigrafica e con i dati ottenuti mediante radiocarbonio per i campioni più giovani (pieistocene superiore) mentre sono sottostimate per i campioni appartenenti al pleistocene medio. le possibili cause di tale comportamento sono discusse. key words: alluvial sediments, osl dating, p o p l ai n, quaternary parole chiave: sedimenti alluvionali, datazione osl, pianura padana, quaternario we applied osl dating techniques to quartz samples from some outcrops in the alluvial quaternary succession of the po plain south of milan, to assist the stratigraphic reconstruction. luminescent dating is in fact used to determined burial ages of sediments that were exposed to sunlight prior to deposition (aitken, 1998). prirnarily we aimed at obtaining new age determinations to tighten the chronological constraints that are traditionally applied to some crucial stratigraphic units, exposed at the so-called "livello fondamentale della pianura (lfp)" (castiglion! & pellegrini, 2001 ). w e focused on three exposures, close to the southern end of the lfp, in different tectono-stratigraphic settings. from sw to ne we sampled: i) the middle pleistocene alluvial sediments in a quarry exposure at the northern flank of the san colombano al lambro isolated hill (desio, 1965), a spur of an apenninic thrust front of the western emilia folds that was active during middle and presumably late pleistocene (pellegrini et al., 2003), ii) the middle pleistocene alluvial sediments of the casalpusterlengo relic relief ("mindel" auct., cremaschi, 1987), al the top of an apenninic anticline, kinematically linked to the san colombano structure (bersezio et al., 2010), and iii) the top of the late pleistocene sediments of the lfp in the lodi depocentre, just south of the interference zone between the alpine and apenninic thrust fronts. these deposits have been indicated on the various geologica! maps at scale 1:100.000, but with a poorly defined age (cremaschi, 1987). five samples were collected by hammering steel tubes into freshly cleaned exposures. the tubes were capped with aluminum sheets and sealed using black plastic bags. samples gema1 and gema2 can be ascribed to the younger cantù alloformation (latest pleistocene, strini, 2001 ), while samples geso1 and geso2 belong to the casalpusterlengo relic relief ("mindel" auct., cremaschi, 1987). sample gebf was taken from the middle pleistocene cascina parina unit (pellegrini et al., 2003) at the northern flank of the san colombano al lambro hill. tab. 1 summarises the stratigraphic position, the main sedimentological characteristics of the samples and their depositional environment. the quartz extraction was made following the conventional procedure (lang et al., 1996). ali the luminescence measurements were conducted on coarse quartz grains (75-120 ~m). the single­ aliquot regenerative-dose (sar) protocol was used to determine the radiation dose absorbed by sediment grains since deposition (murray & wintle, 2000). the osl measurements were made using an automated luminescence system (ris0 tliosl­ da-15), equipped with a 90sr/""v beta source delivering 0.14 gy/s (±3%) to the sample position. the quartz osl was stimulated by an array of blue leds (470±30 nm) for 100 s at 125'c with a constant stirnulation power of 54 mw/cm2 . the calibration of osl data: mismatch between stratighraphy .. 115 sampling stratigraphic dep. environment si te sample depth description and pedological osl age (ka) (cm) position interpretation cantù yellowish gray sandy silt and clay, fluvial; pedogenic lfp alloformation features indicate mairago (lodi). gema2 150 (la test massive, with red mottling, day formalion of an 19±2 pleistocene). coatings and fe-mn nodules. hydromorphic soil. cantù greyish brown, coarse-gra'1ned s'1lty fluvial; pedogenic lfp alloformation features indicate mairago (lodi). gema1 250 (latest sand with grey to red mottling, clay formation of an 16 ±2 pleistocene ). coatings and fe-mn nodules. hydromorphic soil. lsolated terraces coarse to medium-grained, massive alluvial; pedogenic fluvial formation features indicate casalpusterlen (middle sand with norma! grading and mud formalion of go relic relief. geso2 420 pleistocene; chips at the bottom; red ferruginous polycyclic fersiallitic 67 ± 6 costa fagioli. cremaschi, mott!ing, day coatings and fe-mn paleosol with alluvial 1987). concretions. day horizon. lsolated terraces casalpusterlen fluvia! formation coarse lo medium-grained, normally (middle graded gray sand with cross-go relic relief. geso1 500 alluvial. 107 ± 13 costa fagioli. pleistocene; lamination; ferruginous concretions at cremaschi, the bottom. 1987). cascina parina c.na unit (middle fine to coarse-graìned pebbly sands belfuggito. gebf 620 pleistocene; with fine planar lamination and sofl alluvial. 89 ± 9 pellegrini et al., sediment deformation. 2003). t ab. 1. stratigraphic constraints and osl age determinations obtained al the sampling sites. posizione stratigrafica, descrizione ed età osl dei campioni. presence of feldspars was checked using an ir di ode array (830±1 o n m) with a stimulation power of 360 mw/cm2 photons were detected by a bialkali photomultiplier tube (emi 9235qb15) coupled lo a 7.5 mm hoya u-340 filter. the preheat was al 180°c far 10 s far samples gema1 and gebf and 200°c far the other samples. to contrai the purity of the extracted quartz, the osl­ ir-depletion ratio test (duller, 2003) was performed. irsl signals were observed in ali samples. to reduce its presence another hf etching far 40 min was attempted and the test remade. nevertheless, ali samples showed again a significant contribution due to feldspars. for this reason anomalous fading was tested using delayed lx/t x measurements with delays of up lo 1 month. the samples were initially tested using preheat plateau and dose recovery tests. in order lo calculate the annual dose, the th and u concentrations of the sediments were measured with total alpha counting using zns scintillator discs (aitken, 1985), assuming a concentration ratio th/u equal to 3. 4°k conteni was deduced from the total concentration of k that was measured with flame photometry. attenuation of the beta dose was taken into account (bell, 1979). the contribution of cosmic radiation was taken as 0.15 mgy/a al depths of about 1 m. for greater depths attenuation factors were used (aitken, 1985). the results of radioactivity measurements together with the corresponding dose rates are reported in tab. 1. in calculating the dose-rates, il was assumed that the average water conteni over the entire burial period was about 20% for ali samples except for gema1 (30%). the osl age obtained are listed in tab.1. samples gema1 and gema2 yielded osl ages in good agreement with the stratigraphic position and calibration by radiocarbon ages (bersezio et al., 2004 ). differently the osl ages of the other samples do not fil the available stratigraphic constraints (late pleistocene instead of the expected middle pleistocene ). different explanations can be claimed as indicated by recent literature: 1) the samples are too old lo be dated by osl technique. despite the samples haven't reached the saturation and have mel the standard ~ performance criteria set to test the reliability of the sar protocol, they showed underestimation. (buylaert et al., 2007; murray et al. 2007; lowick et al., 201 o); 2) some quartz has luminescence properties that make il problematic far dating application. in fact, despite the fact that quartz is nominally pure si02, the minerai forms in several different geologica! settings. the luminescence properties of quartz are highly variable with geologica! source and vary even al a grain lo grain level within a sediment (gotze et al., 2005; preusser el al., 2009) 3) the samples belong to complex pedogenetic profiles. the role of weathering and water adsorption by quartz grains on osl luminescence is stili poorly understood. 116 references attken m.j. (1985) thermoluminescence dating. academic press, london, 359. attken m.j. (1998) an lntroduction to optica/ dating. oxford university press, oxford, 267. bell w.t. (1979)attenuation factors to absorbed dose in quarlz incfusions far thermoluminescence dating. ancient tl, 8, 2-13. bersezio r., pavia f., baio m., bini a., felletii f.& rooondt c. (2004) aquifer architecture of the quaternary alluvial succession of the southern lambro basin (lombardy, lta/y). il quaternario, 17 (2/1 ), 361378. bersezio r, cavalli e. & cantone m. (2010)aquifer building and apennine tectonics in a quaternary foreland: the southernmost lodi plain of lombardy. memorie descrittive carta geologica d'italia xc, 21-30. buylaert j.p., vandenberghe d., murray a.s., huot s., de corte f. & van den haute p. (2007) luminescence dating of o/d (> 70 ka) chinese loess: a comparison of single-aliquot osl and irsl techniques. quat geochr., 2, 9-14. castiglion! & pellegrini (2001) note illustrative della carta geomorfologica della pianura padana. suppl. geogr. fis. dinam. quat., iv, 207. cremaschi m. (1987) pa/eoso/s and vetuso/s in the centra/ po plain (northern lta/y). unicopli, milano, 306. desto a. (1965) l rilievi isolati della pianura lombarda ed i movimenti tettonici del quaternario. rend. 1st. lomb. ace. sci.lett., 99, 881-894. duller g.a.t. (2003) distinguishing quartz and feldspar in single grain luminescence measurements. l. panzeri et al. radiat. meas., 37, 161-165. gbtze j., plotze m. & trautmann t. (2005) structure and juminescence characteristics of quattz from pegmatites, am. minerai., 90, 13-21. lang a., lindauer s., kuhn r. & wagner g.a. (1996)­ procedures used far optically and infrared stimulate /uminescence dating of sediments in heide!berg. ancienttl, 14,7-11. lowick s.e., preusser f., pini r. & ravazzi c. (2010)­ underestimation of fine grain quartz osl dating towards the eemian: comparison with palynostratigraphy from azzano decimo, northeastem ltaly. quat geochr., 5, 583-590. murray a.s. & wtntle a.g. (2000) luminescence dating of quartz using an improved sing/e-a/iquot regenerative-dose protoco/. radiat. meas., 32, 57-73. murray a.s, buylaert j.p., henriksen m., svendsen j. & mangerud j. (2008) testing the re/iabi/ity of quartz osl ages beyond the eemian. radiat. meas., 43, 776-780. pellegrini l., soni p. & carton a. (2003) hydrographic evolution in relation to neotectonics aided by data processing and assessment: some examples tram the northern apennines (lta/y). quater. lnt., 101102, 211-217. preusser f., chtthambo m.l., gbtie t., martin! m., ramseyer k., sendezera e.j., susino g.j. & g. wtntle a. g. (2009)quartz as a natura/ /uminescence dosimeter. earth sci. rev., 97, 184-214. strini a. (2001) gli occhi pollini della brianza orientale: genesi ed evoluzione del fenomeno nel quadro geologico regionale. tesi di dottorato inedita, xlii ciclo, università di milano, 550. ms. received: january 14, 2011 testo ricevuto il 14 gennaio 2011 imp.sabato& problemi di cartografia geologica relativa ai depositi quaternari del f° 471 “irsina”. il conglomerato di irsina: mito o realtà? luisa sabato1, marcello tropeano2 & piero pieri1 1dipartimento di geologia e geofisica, università degli studi di bari, 70125 bari l.sabato@geo.uniba.it 2dipartimento di scienze geologiche, università della basilicata, 85100 potenza tropeano@unibas.it riassunto: sabato l., tropeano m. & pieri p., problemi di cartografia geologica relativa ai depositi quaternari del f° 471 irsina. il conglomerato di irsina: mito o realtà? (it issn 0394-3356, 2004). il f° 471 “irsina” (basilicata) ricade lungo il confine catena-avanfossa, per cui risulta costituito da due porzioni rappresentative di aree molto differenti sia dal punto di vista morfo-strutturale, che stratigrafico. in particolare, nella parte orientale del foglio affiorano depositi quasi esclusivamente quaternari e ricadenti nell’area della fossa bradanica. la parte superiore ed esposta del riempimento di tale bacino di avanfossa è rappresentata da una successione di sedimenti di tipo regressivo, caratterizzata in basso, e per quasi tutto il suo spessore, da emipelagiti siltoso-argillose (formazione delle argille subappennine), e nella parte alta da depositi grossolani che giacciono in contatto transizionale e/o erosivo sulle emipelagiti. il quadro stratigrafico-deposizionale che deriva dai nuovi rilevamenti effettuati nell’area orientale del foglio irsina si differenzia da quanto proposto nella vecchia carta geologica d’italia e nella letteratura prodotta fino agli inizi degli anni ’90: all'interpretazione che proponeva la presenza di una successione di sedimenti costituenti un sistema aggradazionale, nei quali non era precisata la separazione fra sedimenti costieri e continentali, e nei quali la suddivisione formazionale era basata esclusivamente su criteri litologici, si propone ora quella che riconosce un insieme di sedimenti, di età e quote decrescenti da o a e, derivanti da sistemi progradazionali di transizione formatisi alternativamente durante cicli di variazione relativa del livello del mare, cui si sovrappongono, in contatto di discontinuità, depositi continentali. in particolare, alla formazione nota col nome di conglomerato di irsina, che era descritta e cartografata sia come un unico deposito aggradazionale in contatto stratigrafico sulla sottostante formazione indicata col nome sabbie di monte marano, sia come un deposito sincrono dalle aree più interne (600 m s.l.m.) a quelle più esterne (400 m s.l.m.) rispetto alla catena, venivano attribuiti litosomi conglomeratici riconosciuti ora come corpi posti a diversa altezza stratigrafica, di diversa origine ambientale ed, in alcuni casi, in netta discordanza fra loro. il nuovo rilevamento geologico, associato all’analisi di facies, ha infatti permesso di individuare nell’area del f° 471 “irsina”, una successione sabbioso-conglomeratica (indicata col nome formazionale di sabbie e conglomerati di monte s. marco) al cui interno si riconoscono diversi corpi conglomeratici intercalati che possono essere attribuiti a quattro membri posti a quote ed altezze stratigrafiche differenti, e di età progressivamente più giovane da o a e. abstract: sabato l., tropeano m. & pieri p., geological mapping problems regarding quaternary deposits of the f° 471 irsina. the conglomerato di irsina: myth or reality? (it issn 0394-3356, 2004). the area of the f° 471 “irsina”, on scale of 1: 50.000 (carg), is located in basilicata region (southern italy), along the chain-foredeep border of the south-apennines orogenic system. so, the eastern part of the map regards the bradanic trough (foredeep) domain, while the western one regards deformed units of the chain domain. in particular, the eastern part is represented almost by quaternary deposits, more or less in horizontal arrangment, which correspond to the upper part of the in-fill succession of the foredeep basin. the outcropping succession of the basin is represented by regressive deposits characterized below by hemipelagites of the argille subappennine formation, and above by coarse-grained deposits. these latter lie on the hemipelagites of the argille subappennine fm. in, alternatively, conformable or erosional contact. the new geological survey of the f° 471 irsina and the facies analysis carried out on the outcropping deposits, allow us to present a more detailed stratigraphy of the quaternary bradanic trough deposits, in comparison with that one showed by the old geological survey on scale 1:100.000. the upper pliocene-lower pleistocene silty-clays of the argille subappennine fm. are stratigraphically overlain by the sabbie e conglomerati di monte s. marco formation. this formation is made up of lower pleistocene up to 60 m thick sands, sandstones and conglomerates interpreted as offshore-transition to shoreface systems prograding ontoand distally passing tohemipelagites of the argille subappennine fm. several conglomeratic bodies are interbedded in the sabbie e conglomerati di monte s. marco fm., and locally some of them are in erosion on the argille subappennine fm. these bodies have a sigmoidal shape, are clinostratified and show thicknesess variable from some meters to over 60 m. the deposits of these bodies are referred to transitional environments, mostly characterized by deltaic facies; they crop out at different heights above present-day sea level, and their age becomes younger from w to e, from the higher to the lower. according to their stratigraphic position, some of these bodies represent different enter points along the same paleoshoreline; they may be considered coeval and grouped in four members here called: conglomerato di giumentarizzo, conglomerato di madonna della pietà di irsina, conglomerato di monte s. angelo, conglomerato di sant’antonio abate. erosively overlying either the sabbie e conglomerati di monte s. marco fm. or the conglomeratic members, a sandy-conglomeratic deposit is observed. this latter, named sabbie e conglomerati di fosso macello formation, is up to 10 m thick and is related to alluvial environments. the new stratigraphic setting results quite different from that proposed by the previous italian geological cartography on scale of 1:100.000, in which the bradanic trough infill succession was characterized by aggradation of shallow marine and continental deposits. in particular, the conglomerato di irsina formation was described and mapped as a single aggradational deposit overlying the sabbie di monte marano formation, and having the same age from the inner areas (600 m above s.l.) to the outer ones (400 m above s.l.). in the irsina area, where the conglomerato di irsina fm. was established, the new geological survey demonstrates that this deposit is really composed by three conglomeratic lithosomes having different age and different environmental and stratigraphic meaning: a first lithosome is composed of foreshore conglomerates that locally represent the upper part of a regressive sandy succession; the second lithosome is composed of clinobedded deltaic conglomerates erosionally overlying the previous sandy-conglomeratic succession and, distally, the clay deposits; a third lithosome is represented by a continental sandy-conglomeratic deposit erosionally overlying the previous ones. in the old italian geological cartography on scale of 1:100.000 these three lithosomes were represented as one tabular body, aggrading and partially etheropic with the underlying sabbie di monte marano fm. so, the deposits that we now distinguish into three lithosomes (upper part of the sabbie e conglomerati di monte s. marco formation, conglomerato di madonna della il quaternario italian journal of quaternary sciences 17(2/1), 2004, 391-404 392 l. sabato, m. tropeano & p. pieri 1. introduzione nell’ambito del progetto carg, la regione basilicata è stata incaricata di redigere una serie di fogli geologici in scala 1:50.000 ricadenti nell’area regionale. fra questi è compreso il f° 471 “irsina”, che, poiché ricade lungo il confine catena-avanfossa (fig. 1), presenta due porzioni relative ad aree molto differenti fra loro sia dal punto di vista morfo-strutturale, che stratigrafico. nell’area occidentale affiorano unità della catena appenninica, rappresentate da terreni cretacico-terziari derivanti dalla deformazione di un dominio paleogeografico di bacino (bacino di lagonegro esterno evolutosi a bacino irpino) e da depositi plio-pleistocenici di bacini satellite. l’assetto strutturale di tale area è particolarmente complesso, e legato a tettonica polifasica miocenico-quaternaria; in linea generale può essere descritto come un sistema di thrusts e pieghe adriaticovergenti di età neogenico-quaternaria, complicato da strutture trascorrenti e distensive plio-pleistoceniche (sia in direzione appenninica che antiappenninica). nell’area orientale invece affiorano le unità della fossa bradanica, rappresentate per uno spessore di circa 450 m da depositi silicoclastici, quasi esclusivapietà di irsina member and sabbie e conglomerati di fosso macello formation), in the old survey, by mistake, were included only in the conglomerato di irsina formation. also in other localities we observe the occurrence of different conglomeratic lithosomes not distinguished in the old survey. in short, it does not exsist an only conglomeratic and coeval formation on the top of the regressive bradanic succession, so the conglomerato di irsina formation, as established in the sixties and known in the literature, has to be amended. furthermore, the new data demonstrate that the deposits and the upper surface of the bradanic reliefs do not represent an only regressive episode, but a serie of regressive episodes recorded during the tectonic uplift of the bradanic basin. in fact, the stratigraphic organization show a progradational trend rather than an aggradational one. on this subject, the different heights which the regressive deposits outcrop to (from about 600 m a.s.l., up to 400 m a.s.l. in the surveyed area) are not the result of a differential uplifting of the basin after the marine sedimentation, but the recording of the regional uplift occurring during the sedimentation. parole chiave: quaternario cartografia geologica conglomerato di irsina depositi regressivi. keywords: quaternary geological mapping conglomerato di irsina formation regressive deposits. fig. 1 a) principali caratteri strutturali dell’italia; b) quadro geologico schematico dell'italia meridionale; c) distribuzione dei “depositi costieri regressivi” nella zona assiale della fossa bradanica (da pieri et al., 1996); il riquadro indica l’area in cui ricade il f° 471 “irsina”. a) main structural features of italy; b) schematic geological map of southern italy; c) areal distribution of the “depositi costieri regressivi” in the axial part of the bradanic trough (from pieri et al., 1996); the insect shows the location of the f° 471 “irsina”. mente quaternari, con granulometria variabile dal basso verso l’alto da argilloso-siltosa a sabbiosa e/o conglomeratica. tali depositi costituiscono la nota successione della fossa bradanica che si chiude con i termini regressivi (fig. 1, c) oggetto di questa nota. nonostante la pressoché assenza di deformazioni tettoniche, i caratteri stratigrafici di questi depositi si sono rivelati più complessi rispetto a quanto riportato in letteratura, sia per l’estrema variabilità laterale e verticale dei caratteri litologici, sia per la variabilità dei contatti stratigrafici riconosciuti. a queste difficoltà intrinseche si è aggiunta l’esiguità degli studi di dettaglio sedimentologico riferiti in letteratura a tali depositi. il nuovo rilevamento geologico, effettuato in scala 1:25.000 e, in alcuni casi, in scala 1:10.000, associato ad un’accurata analisi di facies, ha permesso, dal punto di vista strettamente cartografico, di distinguere unità differenti rispetto a quelle cartografate nel foglio geologico di riferimento n°188 gravina di puglia (azzaroli et al., 1968a) che, sia per la scala cartografica utilizzata (1:100.000) che per l’assenza di dati stratigrafici e sedimentologici di dettaglio raccolti durante i rilevamenti degli anni ‘60, erano state inglobate in unità formali non più utilizzabili (si vedano le discussioni in: pieri et al., 1996; sabato, 1996) lo scopo di questo lavoro è di presentare il nuovo quadro stratigrafico proposto per le unità regressive della fossa bradanica nell’area del foglio irsina e di contribuire alla discussione inerente i criteri cartografici, relativi ai deposti del quaternario, da utilizzare nella redazione delle nuove carte geologiche. i dati esposti permettono inoltre di fornire ulteriori informazioni riguardo alle fasi finali di riempimento della fossa bradanica. 2. inquadramento geologico i depositi quaternari rilevati nella parte orientale del foglio irsina ricadono nella fossa bradanica, che rappresenta l’avanfossa sudappenninica plio-pleistocenica, posta fra il fronte della catena appenninica a ovest, e l’avampaese apulo a est (migliorini, 1937; selli, 1962; ricchetti, 1980) (fig. 1, a, b). il riempimento di tale bacino ha inizio durante la parte alta del pliocene inferiore e il pliocene medio, su un’ampia area subsidente dell’avampaese apulo (ciaranfi et al., 1979), e i depositi risultanti si sedimentano su un substrato roccioso carbonatico in precedenza esposto (crescenti, 1975). lo spessore complessivo della successione bradanica supera i 2000 m; la parte sepolta della successione, infrapliocenico-infrapleistocenica, è principalmente caratterizzata da un complesso torbiditico (casnedi, 1988; 1991), mentre la parte affiorante, quaternaria, è costituita da argille siltose emipelagitiche (valduga, 1973; ciaranfi et al., 1979), al di sopra delle quali si rinvengono depositi grossolani di mare sottile, silicoclastici, meno diffusamente carbonatici, relativi sia alle ultime fasi di riempimento dell’avanfossa (ricchetti, 1967) sia al successivo sviluppo di depositi marini terrazzati (vezzani, 1967). la parte più interna dell’intera successione di riempimento è caratterizzata dalla presenza del cosiddetto “alloctono”, un complesso di terreni caotici di età pre-pliocenica che si interpone ai depositi di avanfossa sovrapponendosi a quelli torbiditici di età pliocenico-infrapleistocenica (casnedi et al., 1982). 393problemi di cartografia ... come accennato, la parte alta affiorante della successione plio-pleistocenica, spessa all’incirca 600 m, è rappresentata da depositi argillosi emipelagitici passanti in alto a una serie di depositi generalmente grossolani. la storia evolutiva del bacino, per quanto riguarda i depositi affioranti, è caratterizzata inizialmente da subsidenza parzialmente compensata da sedimentazione emipelagitica; dal pleistocene inferiore (emiliano), a partire dal settore centrale del bacino (area di banzi e genzano), si produce il colmamento a causa del sollevamento tettonico che interessa la regione (pieri et al. 1994; 1996). sulle emipelagiti, rappresentate dalle argille subappennine (azzaroli et al., 1968b; valduga, 1973; ciaranfi et al., 1979), si accumulano quindi depositi grossolani di mare sottile e/o continentali, corrispondenti allo stadio regressivo della storia evolutiva del bacino (pieri et al., 1996). secondo la carta geologica d’italia questi depositi, accumulatisi per meccanismi aggradazionali, costituiscono corpi tabulari attribuibili alle seguenti formazioni: sabbie di monte marano, calcareniti di monte castiglione, sabbie dello staturo, conglomerato di irsina (ricchetti, 1965; 1967; azzaroli et al., 1968a; 1968b; boenzi et al., 1971a; 1971b; valduga, 1973). studi più recenti, sia di carattere regionale (pieri et al., 1994; 1996; tropeano et al., 2002a; 2002b; sabato et al., 2004) che locale (sabato, 1996; lazzari, 1998; lazzari & pieri, 2002; cilumbriello, 2004; pieri et al., 2004), mostrano però un quadro geologico–stratigrafico molto differente. da questi lavori risulta che i depositi sabbioso-conglomeratici relativi alle fasi finali di riempimento della fossa bradanica si rinvengono in contatto sia transizionale che erosivo sulle argille subappennine e che alcuni corpi conglomeratici sono intercalati alle successioni sabbiose. inoltre tali depositi, denominati informalmente “depositi costieri regressivi” (fig. 1, c) da pieri et al. (1994) ed il cui spessore complessivo varia fino ad un massimo di 100 m, posseggono caratteri di facies variabili da marino-transizionali a continentali (massari & parea, 1988; 1990; pieri et al., 1994; 1996; 2004; sabato, 1996; lazzari, 1998; lazzari & pieri, 2002; tropeano et al., 2002a; 2002b; cilumbriello, 2004). 3. caratteri di facies e suddivisione formazionale dei depositi quaternari sabbioso-conglomeratici sommitali della fossa bradanica nel foglio irsina in questo capitolo saranno descritti i principali caratteri stratigrafici e di facies osservati per il complesso dei depositi sabbioso-conglomeratici poggianti sulle argille subappennine; lo studio di tali caratteri ha portato a proporre le suddivisioni formazionali introdotte nel foglio irsina della nuova carta geologica d’italia. nell’area del foglio irsina, il complesso dei depositi che poggia stratigraficamente sulle argille subappennine è rappresentato da una unità infrapleistocenica prevalentemente aggradazionale sabbiosa o sabbiosoconglomeratica (sabbie e conglomerati di monte s. marco) nell’ambito della quale si intercalano quattro membri conglomeratici prevalentemente progradazionali (conglomerato di giumentarizzo, conglomerato di madonna della pietà di irsina, conglomerato di monte s. angelo, conglomerato di s. antonio abate), (fig. 2). 394 fig. 2 carta geologica schematica del f° 471 “irsina”. schematic geological map of the f° 471 “irsina”. l. sabato, m. tropeano & p. pieri 395 al di sopra di tali depositi, in contatto erosivo e discordante si rinviene la formazione denominata sabbie e conglomerati di fosso macello. 3.1 sabbie e conglomerati di monte s. marco tale formazione, la cui istituzione è stata proposta precedentemente da sabato (1996), è costituita da depositi sabbiosi, o sabbioso-conglomeratici, affioranti a partire da quote variabili da circa 400 a circa 630 m s.l.m. tali depositi poggiano in continuità per alternanza sulle argille subappennine; hanno spessori variabili da 25÷30 m fino a circa 60 m, e i caratteri di facies sono in genere riferibili ad ambienti di transizione. di seguito vengono descritti i caratteri di facies di tale formazione nelle aree dove meglio affiora, e cioè nei dintorni dell’abitato di irsina (fig. 3). nell’area di irsina, nei pressi di località monte s. marco, tale unità è rappresentata da depositi principalmente sabbioso-arenacei e subordinatamente conglomeratici, aventi spessori di oltre 50 m. dal basso verso l’alto la formazione è costituita da alcuni metri di argille e argille siltose ben stratificate e intensamente bioturbate cui seguono silt con laminazione parallela e da ripple, ricchi di livelli sabbiosi, a volte con base erosiva, con lamine parallele e oblique a basso angolo e da ripples. in questi depositi sono presenti frequenti macrofossili e resti vegetali, oltre che abbondanti foraminiferi, sia bentonici che planctonici (sabato, 1996). tali depositi rappresentano i termini di passaggio alle argille subappennine e presentano caratteri di facies relativi ad ambienti di piattaforma-transizione a shoreface interessati da eventi di tempesta. al di sopra, per uno spessore di circa 25 m, si rinvengono sabbie e arenarie fini con laminazioni pianofig. 3 caratteri stratigrafici e di facies dei depositi sommitali della fossa bradanica affioranti nell’area di irsina (modificata da sabato, 1996). stratigraphic and facies characters of the upper deposits of the bradanic trough outcropping in the irsina area. (modified from sabato, 1996). problemi di cartografia ... 396 parallele, ondulate, da ripples o oblique a basso angolo (hummocky); spesso si osservano superfici erosive marcate da orizzonti di lamellibranchi, e frequente è la bioturbazione, prevalentemente da echinidi. tali caratteri di facies sono riferibili ad ambienti di shoreface inferiore (sabato, 1996). la parte alta della successione ha spessori variabili fino ad un massimo di circa 15 m. essa è rappresentata o da sabbie grossolane, bioturbate, ricche di lamellibranchi, passanti verso l'alto a conglomerati in strati a gradazione inversa, oppure da sabbie e conglomerati gradati inversamente, ricchi di ostree, e ben affioranti in località vallone delle noci e monte s. marco (figg. 3, 4). in genere i depositi sono clinostratificati, con angoli di circa 10° e direzione di progradazione da no a se. l'analisi di facies permette di riferire tali depositi ad ambienti di shoreface superiore, ghiaiosa o sabbiosa, passante a luoghi verso l'alto ad ambienti di foreshore (sabato, 1996), (fig. 4). a varie altezze stratigrafiche nelle sabbie e conglomerati di monte s. marco si rinvengono diversi corpi prevalentemente conglomeratici a geometria cuneiforme e con spessori variabili fino a un massimo di 60 m. tali corpi presentano caratteri di shallowing upward, e sono caratterizzati da facies di transizione, a luoghi passanti verso l’alto a facies continentali. in base ai caratteri di facies che verranno di seguito descritti, ognuno di tali corpi è riferibile a un apparato deltizio ghiaioso. il limite inferiore di questi corpi deltizi corrisponde ad una brusca variazione litologica rispetto alle sabbie; il contatto è generalmente di continuità stratigrafica, ma localmente è rappresentato da una superficie erosiva che in alcuni casi raggiunge le argille subappennine. questi corpi grossolani sono stati correlati per quota (considerando coevi, con questo criterio, differenti apparati deltizi non continui lateralmente) e sono stati riferiti, sotto il profilo stratigrafico, a quattro membri, che dal più antico sono: conglomerato di giumentarizzo, conglomerato di madonna della pietà di irsina, conglomerato di monte s. angelo, conglomerato di s. antonio abate (fig. 2). 3.2 conglomerato di giumentarizzo tale membro possiede uno spessore di almeno 8 m, ed è rappresentato da depositi prevalentemente conglomeratici, il cui contatto basale è brusco, ma di continuità, su facies sabbiose della formazione delle sabbie e conglomerati di monte s. marco, cui si intercala. alla base, per circa un metro, è caratterizzato da depositi conglomeratici con clasti arrotondati e subsferici del diametro di 10÷15 cm, cui segue un metro di alternanze decimetriche di arenarie e conglomerati. seguono 6 m di conglomerato a matrice sabbiosa (fig. 5), con rare lenti sabbiose, clinostratificato con foreset immergenti verso i quadranti sud-orientali; localmente si osservano livelli con clasti di dimensioni di circa 30÷40 cm, con fori di litodomi. in genere il conglomerato è disorganizzato, localmente matrice-sostenuto, con clasti solo raramente appiattiti, e a luoghi subangolari. i depositi sottostanti e sovrastanti il membro in oggetto sono rappresentati da sabbie e arenarie bioturbate e con strutture tipo hummocky. il conglomerato di giumentarizzo è riferibile ad un ambiente deltizio, le cui facies si intercalano bruscamente a facies sabbiose di ambienti di piattaformatransizione a shoreface, appartenenti alla formazione delle sabbie e conglomerati di monte s. marco (pieri et al., in prep.). 3.3 conglomerato di madonna della pietà di irsina a tale membro vengono attribuiti tre corpi cuneiformi prevalentemente conglomeratici, due ben affioranti, uno presso l’abitato di irsina e uno presso l’abitato di grassano, ed un terzo subaffiorante in località corona romana-mass.ia d’amati. nell’area di irsina tale membro presenta spessori variabili da pochi metri fino a circa 60 m, ed al suo interno si distinguono una unità bottomset, una foreset e una topset. l’unità foreset, a geometria cuneiforme, è formata da strati conglomeratici, e più raramente sabbiosi, clinostratificati, con spessori variabili da pochi metri nelle fig. 4 parte alta della formazione delle sabbie e conglomerati di monte s. marco dove si osservano livelli di conglomerati clinostratificati e ben selezionati, con ciottoli molto appiattiti e indicanti una prevalente immersione verso mare. caratteri di battigia. località monte s. marco. upper part of the sabbie e conglomerati di monte s. marco formation. clinostratified and well-sorted conglomeratic layers are evident; clasts are disc-shaped and show dipping seawards imbrications. gravelly beachface. san marco locality. l. sabato, m. tropeano & p. pieri aree prossimali, dove la sequenza è incompleta a causa della mancanza dell’unità bottomset, a circa 40 m nelle aree distali, dove aumenta la presenza di interstrati sabbiosi, e compaiono gradualmente gli strati appartenenti all’unità bottomset. i clinoformi mostrano una inclinazione variabile da circa 30° nelle aree prossimali (dove poggiano sulle argille subappennine lungo una superficie erosiva; figg. 6, 7), fino a raggiungere valori prossimi all'orizzontale nelle aree distali, poste verso se, dove le superfici dei clinoformi diventano tangenziali, e passano gradualmente all’unità bottomset. all’interno dell’unità foreset si individuano inoltre superfici erosive che separano gruppi di strati clinostratificati a diversa inclinazione. verso l’alto si osservano solchi erosivi prodotti da canali, profondi fino a 1 m e larghi alcuni metri, riempiti in basso da conglomerati e verso l’alto da depositi sab397 fig. 5 parte alta del conglomerato di giumentarizzo ; si osservi che le facies ghiaiose deltizie passano superiormente a facies sabbiose di ambienti di piattaforma-transizione a shoreface (formazione delle sabbie e conglomerati di monte s. marco). upper part of the deltaic conglomerato di giumentarizzo member. upwards it passes to sandy shoreface-transition to offshore environments (sabbie e conglomerati di monte s. marco fm.). fig. 6 i l conglomerato di madonna della pietà di irsina in appoggio erosivo sulle argille subappennine nei dintorni dell’abitato di irsina. the conglomerato di madonna della pietà di irsina deltaic deposits erosively overlie the clay deposits of the argil le subappennine fm. fig. 7 schema deposizionale dei depositi sommitali della fossa bradanica affioranti a irsina. (modificata da sabato, 1996). depositional scheme of the upper deposits of the bradanic trough outcropping in the irsina area. (modified from sabato, 1996). problemi di cartografia ... bioso-conglomeratici. i clinoformi hanno geometria sigmoidale, sono spessi alcuni decimetri, e mostrano gradazione inversa o inversa-normale. in genere hanno tessitura granulo-sostenuta, con matrice sabbiosa; localmente si osservano anche strati a tessitura matrice-sostenuta, con abbondante matrice siltoso-marnosa. gli strati sabbiosi e/o siltosi intercalati sono laminati e contengono livelli ghiaiosi o ciottoli sparsi. i clasti sono in genere ben arrotondati, e il grado di sfericità aumenta con la dimensione: fino a 10 cm hanno forma appiattita, mentre quelli con dimensioni maggiori, fino a 30 cm, hanno forma subsferica. le misure di paleocorrente, ricavate da assi di canale, embriciatura e direzione di progradazione dei clinoformi indicano provenienze da nno. come detto, distalmente i clinoformi diventano gradualmente suborizzontali (unità bottomset) e prevalentemente sabbiosi, e contengono una microfauna essenzialmente rappresentata da elphidium advenum, nonion depressulum. l'unità topset ha uno spessore massimo di circa 10 m ed è in contatto erosivo sull'unità foreset nelle aree prossimali (geometria obliqua), come si può osservare subito a ovest dell’abitato di irsina, mentre nelle aree distali passa gradualmente all’unità foreset (geometria sigmoidale). gli strati dell’unità topset sono suborizzontali, e sono rappresentati da conglomerati ricchi di intercalazioni sabbiose. i clasti hanno dimensioni inferiori rispetto a quelli dell’unità foreset, e mostrano una embriciatura verso mare ben sviluppata. l'analisi di facies permette di riferire l’intero corpo grossolano affiorante ad irsina ad un delta di tipo gilbert (sensu gilbert, 1885), dominato dall’azione delle onde (sabato, 1989; 1996), in parziale accordo con massari & parea (1990), che attribuiscono al corpo deltizio anche depositi non correlabili al corpo in oggetto, e qui riferiti a facies di avanspiaggia della locale porzione sommitale delle sabbie e conglomerati di monte s. marco (fig. 7). nell’area di grassano il corpo conglomeratico attribuito al membro del conglomerato di madonna della pietà di irsina poggia attraverso un brusco contatto prima transizionale e poi erosivo sulle sabbie e conglomerati di monte s. marco (fig. 8). si tratta di un corpo conglomeratico spesso circa 10 m, all’interno del quale si possono distinguere una unità foreset ed una topset (fig. 9). l’unità foreset è cuneiforme, il suo spessore decresce da 5 a 2,5 m spostandosi dalle aree prossimali a quelle distali, ed è formata da strati prevalentemente conglomeratici e subordinatamente arenacei, che progradano verso nord-est; la stessa unità verso l’alto mostra una complessa geometria obliquo-sigmoidale. i 398 fig. 9 contatto foreset/topset nel conglomerato di madonna della pietà di irsina affiorante in località cinti, a grassano. foreset/topset boundary in the conglomerato di madonna della pietà di irsina member. cinti locality, grassano village. fig. 8 schema deposizionale dei depositi sommitali della fossa bradanica affioranti a grassano. (modificata da tropeano et al., 2002a). depositional scheme of the upper deposits of the bradanic trough outcropping in the grassano area. (modified from tropeano et al., 2002a). l. sabato, m. tropeano & p. pieri clinoformi che compongono l’unità hanno spessori variabili da alcune decine di centimetri fino al metro, hanno una base angolare e/o tangenziale, una geometria cuneiforme e la loro inclinazione decresce verso bacino, variando da 17° a 5° circa. gli strati conglomeratici contengono clasti arenacei, granitici e carbonatici, ben arrotondati, e clasti silicei subangolari, con un diametro medio di 7÷8 cm. i clasti arenacei risultano ben appiattiti e mostrano embriciature dirette sia verso terra che verso mare; le evidenze di paleocorrente indicano direzioni prevalenti verso est. in genere i clinoformi conglomeratici sono clasto-sostenuti e gradati normalmente, con scarsa matrice sabbiosa grossolana; frequentemente si osserva un aumento della granulometria al piede, soprattutto dove l’altezza dei clinoformi è minore, con clasti di diametro da pochi centimetri fino a 60 cm; a luoghi si osserva la presenza di ostree incrostate su ciottoli, alla base dei clinoformi. i clinoformi arenacei mostrano una laminazione obliqua ad alto angolo immergente verso terra. il contatto fra l’unità foreset e quella topset è messo in evidenza da una netta diminuzione della dimensione dei clasti, con diametri in media di 3÷4 cm. l’unità topset (fig. 9) è formata per i primi 1,4 m da un conglomerato organizzato in strati orizzontali spessi circa 20 cm, che mostrano al loro interno una laminazione obliqua a basso angolo con immersioni verso mare; la matrice è rappresentata da sabbia grossolana e l’embriciatura dei clasti indica paleoflussi diretti verso ne. i successivi 2 m, che chiudono l’unità topset, sono composti da conglomerati molto ben selezionati, con ciottoli in media di 6÷7 cm, appiattiti e mostranti embriciature verso mare. al di sopra dell’unità topset si rinviene un conglomerato spesso circa 2 m, matrice-sostenuto e poco organizzato. l’analisi di facies relativa al membro del conglomerato di madonna della pietà di irsina affiorante nell’abitato di grassano porta ad interpretare questo corpo come un delta tipo gilbert (sensu gilbert, 1885) dominato dalle onde (pieri et al., in prep.) passante verso l’alto ad ambienti di shoreface e beachface ed infine ad ambienti alluvionali. distalmente, in località serra martello, i depositi deltizi passano e vengono coperti da arenarie di shoreface inferiore-transizione all’offshore (fig. 8), appartenenti al le sabbie e conglomerati di monte s. marco. il terzo corpo attribuito al membro del conglomerato di madonna della pietà di irsina affiora a corona romana-mass.ia d’amati. in questo caso i depositi, ghiaioso-conglomeratici, sono spessi fino ad un massimo di circa 20 m, e sono in genere mal affioranti. il contatto basale è prima di continuità su facies sabbiosoconglomeratiche (nelle aree di affioramento più alte in quota) poi, distalmente (nelle aree di affioramento più basse in quota), di erosione su facies sabbiose e sabbioso-argillose appartenenti alle sabbie e conglomerati di monte s. marco. nei pressi di mass.ia d’amati, il conglomerato di madonna della pietà di irsina poggia in continuità su facies sabbiose con fitte laminazioni oblique (fig. 10) e strutture tipo gutter ghiaiose; qui il membro è ben affiorante solo per uno spessore di circa 8÷10 m, ed è caratterizzato per i primi 2 m da conglomerati in unità di 40÷50 cm con clasti arrotondati aventi dimensioni da pochi centimentri fino a 10 cm, a gradazione inversa, cui seguono livelli sabbiosi, a volte discontinui; raramente sono presenti clasti fuori misura, di 20÷30 cm di diametro. i successivi 2 m sono ricchi di intercalazioni sabbiose con lamine oblique a vario angolo, contenenti ciottoli con fori di litodomi. negli ultimi 4 m diminuiscono le intercalazioni sabbiose e i conglomerati diventano meno organizzati; la granulometria dei clasti aumenta, con medie di circa 6÷8 cm, e diventano più frequenti quelli di circa 20 cm. verso valle siggiano lo stesso corpo affiora in maniera molto discontinua; si riconoscono facies ghiaiose grossolane disorganizzate, con clasti di dimensioni superiori a quelle osservate nella sezione di mass.ia d’amati. queste facies poggiano in contatto erosivo su facies sabbiose e sabbioso-argillose appartenenti alle sabbie e conglomerati di monte s. marco. le facies caratteristiche del corpo conglomeratico descritto vengono riferite a sistemi deltizi ghiaiosi in regressione deposizionale su depositi di shoreface inferiore e progressivamente in regressione erosiva su depositi di piat399 fig. 10 contatto di transizione del membro del conglomerato di madonna della pietà di irsina sulle facies sabbiose della formazione delle sabbie e conglomerati di monte s. marco in località mass.ia d’amati. transitional contact of the conglomerato di madonna della pietà di irsina member on the sandy facies of the sabbie e conglomerati di monte s. marco fm. mass.ia d’amati locality. problemi di cartografia ... taforma-transizione a shoreface (pieri et al., in prep.). distalmente e frontalmente rispetto agli affioramenti conglomeratici, le successioni subaffioranti alla stessa quota sono rappresentate da facies sabbiose, appartenenti alle sabbie e conglomerati di monte s. marco. le successioni sabbiose raggiungono quindi quote superiori rispetto a quelle del locale appoggio basale del conglomerato di madonna della pietà di irsina; localmente ciò indica che nel tempo l’alimentazione ghiaiosa si è interrotta ed è ripresa la sedimentazione sabbiosa che aveva preceduto lo sviluppo del cuneo deltizio. 3.4 conglomerato di monte s. angelo a tale membro vengono attribuiti due corpi cuneiformi prevalentemente conglomeratici, affioranti uno in località monte s.angelo, l’altro nei pressi di mass.ia cecere. di seguito vengono descritti i caratteri di facies del primo, in quanto riferito al corpo meglio affiorante. in località monte s. angelo tale membro è rappresentato da un corpo conglomeratico spesso circa 30 m, con base erosiva. nella parte bassa si osservano livelli conglomeratici e livelli sabbiosi, entrambi di spessori decimetrici, che si alternano; le sabbie sono pulite e laminate, i conglomerati sono ben organizzati, con ciottoli appiattiti e di dimensioni in media di 7÷8 cm. nella parte alta aumentano i conglomerati, che diventano disorganizzati, con ciottoli prevalentemente subsferici, spesso di dimensioni di 20÷30 cm, raramente di 50 cm. le intercalazioni sabbiose, più rare rispetto alla parte inferiore, presentano strutture da trough. nella parte superiore i conglomerati si presentano clinostratificati, con inclinazioni di circa 10°. i caratteri di facies fanno riferire il corpo grossolano affiorante in località monte s. angelo ad un sistema deltizio (pieri et al., in prep.), in parziale accordo con massari & parea (1990), che attribuiscono questi depositi allo stesso apparato deltizio affiorante ad irsina. 3.5 conglomerato di sant’antonio abate tale membro affiora solo per una piccola parte nel f° 471 irsina; è rappresentato da un corpo conglomeratico cuneiforme, a base erosiva, con spessori variabili fino ad un massimo di 60 m. il corpo risulta clinostratificato con clinoformi inclinati fino a un massimo di circa 20°÷25°, aventi spessore massimo di 1 m, gradazione diretta, e più raramente inversa. i clasti, prevalentemente a composizione arenacea, hanno dimensioni medie di 5÷6 cm e massime di 20 cm, e si presentano generalmente ben arrotondati, e spesso appiattiti, dando indicazioni di paleocorrenti dirette verso i quadranti orientali. spesso sono presenti sabbie con ciottoli, in lenti o in livelli continui. la matrice è sabbioso-microconglomeratica, e solo raramente è molto abbondante. l’analisi di facies permette di riferire tali depositi ad un ambiente deltizio (pieri et al., in prep.). 3.6 sabbie e conglomerati di fosso macello al di sopra dei depositi sabbioso-conglomeratici (formazione delle sabbie e conglomerati di monte s. marco, e membri conglomeratici intercalati), poggia in netta discordanza tramite una superficie erosiva, un deposito sabbioso-conglomeratico (figg. 7, 8, 11), ricco di matrice terroso-argillosa rosso-bruna. lo spessore di tali depositi è variabile da luogo a luogo, da pochi decimetri fino a oltre 10 m. in generale si tratta di depositi matrice-sostenuti, con ghiaie e conglomerati disorganizzati, e con ciottoli aventi diametri variabili da 1 a 10 cm. a luoghi i depositi sono clinostratificati a basso angolo, o presentano canali di larghezza di poco superiore al metro. tali depositi inoltre sono ricchi di livelli carboniosi e croste manganesifere. in accordo con sabato (1996), i caratteri di facies fanno riferire le sabbie e conglomerati di fosso macello ad ambienti continentali di tipo alluvionale, successivi all’emersione dell’area e non correlabili con i depositi marino-transizionali e continentali delle formazioni sottostanti. 4. discussione 4.1 membri conglomeratici o sintemi? cartograficamente, ad eccezione del conglomerato di giumentarizzo, i corpi conglomeratici deltizi a 400 fig. 11 deposito sabbioso e/o ghiaioso-conglomeratico arrossato in facies alluvionale appartenente alle sabbie e conglomerati di fosso macello, in contatto discordante erosivo sui sottostanti depositi deltizi del conglomerato di madonna della pietà di irsina, in giacitura foreset, affiorante nei pressi dell'abitato di irsina. the alluvial deposits of the sabbie e conglomerati di fosso macello formation erosively overlie the gilbert-type delta sequence (conglomerato di madonna della pietà di irsina member) in irsina area. l. sabato, m. tropeano & p. pieri geometria cuneiforme riconosciuti nelle porzioni alte della successione regressiva bradanica sembrano poggiare sulla formazione delle sabbie e conglomerati di monte s. marco (fig. 2). questa apparente evidenza stratigrafica aveva portato inizialmente gli scriventi (anche in base a pressioni del servizio geologico) ad individuare come un supersintema l'insieme dei conglomerati deltizi e come sintema ogni singolo corpo deltizio. dopo una lunga fase di discussione ed ulteriori verifiche di campo si è optato per considerare i corpi conglomeratici come membri al l ' interno della formazione delle sabbie e conglomerati di monte s. marco, nonostante il loro frequente appoggio basale erosivo. questa scelta deriva in parte da evidenze di affioramento e in parte da considerazioni legate ai sistemi deposizionali di riferimento e ad una loro schematica interpretazione evolutiva in termini sequenziali. dal punto di vista geometrico, i corpi ghiaiosi deltizi occupano quasi sempre la porzione sommitale dei rilievi collinari bradanici. si è osservato però che la quota di appoggio dei corpi conglomeratici è sempre altimetricamente più bassa della quota raggiunta dall'unità sabbiosa affiorante frontalmente al corpo ghiaioso progradante (vedi p. es. lo schema di fig. 8). in pratica, durante la sedimentazione del corpo ghiaioso deltizio, distalmente si deponevano sabbie e argille; l'interruzione degli apporti ghiaiosi permetteva l'aggradazione di successioni esclusivamente sabbiose, che sigillavano distalmente il corpo ghiaioso deltizio o la sua porzione sabbiosa distale (praticamente indistinguibile utilizzando esclusivamente metodi di rilevamento di campo e considerando la scarsa continuità laterale degli affioramenti). questo giustificherebbe anche la presenza di facies ghiaiose non cartografabili all'interno della successione sabbiosa. l'interpretazione evolutiva in termini schematicamente sequenziali supporta la scelta formazionale operata. infatti regionalmente è stato suggerito che la successione regressiva bradanica rappresenti la testimonianza sedimentaria del colmamento del bacino durante le prime fasi del sollevamento regionale tuttora in atto (pieri et al., 1996; tropeano et al., 2002a, b). la registrazione del sollevamento tettonico è data dal fatto che la quota sommitale della chiusura delle successioni marine con facies di spiaggia o deltizie è progressivamente più bassa spostandosi dal fronte della catena verso sud-est. il sollevamento regionale, interferendo con le variazioni eustatiche del livello del mare, ha determinato la formazione di una successione regressiva che alternativamente è caratterizzata da facies prevalentemente sabbiose ed aggradazionali durante le fasi di relativa risalita e stazionamento alto del livello del mare (formazione delle sabbie e conglomerati di monte s. marco) e da facies prevalentemente ghiaiose e progradazionali (membri conglomeratici), poggianti e passanti distalmente a sabbie (formazione delle sabbie e conglomerati di monte s. marco), durante le fasi di relativa caduta e stazionamento basso del livello del mare (fig. 12), (tropeano et al., 2002a, b). inoltre, i depositi ghiaiosi deltizi che attualmente occupano quote simili si sono formati durante lo stesso intervallo di relativa caduta e stazionamento del livello del mare e, pur se originariamente non continui, occupano la stessa posizione stratigrafica e sono quindi stati raggruppati nello stesso membro (p. es. delta ghiaioso a irsina, delta ghiaioso a corona romana, e delta ghiaioso a grassano), (fig. 2). 4.2 il conglomerato di irsina: la fine di un mito la formazione del conglomerato di irsina, così come istituita durante i lavori per la realizzazione della carta geologica d’italia in scala 1:100.000 (azzaroli et al., 1968a, b; boenzi et al., 1971a, b), è stata considerata, e lo è tuttora da alcuni autori, il termine che regionalmente chiude la sequenza regressiva della fossa bradanica in appoggio sulla formazione delle sabbie di monte marano (fig. 12) e in eteropia con le formazioni delle argille calcigne e delle sabbie dello staturo. la maggior parte degli autori descrive la formazione del conglomerato di irsina come un deposito continentale in facies fluviale, con episodiche "sommersioni sotto le acque del mare"; tuttavia nell'area di spinazzola, banzi e genzano (compresa nei quadranti occidentali del foglio 188 “gravina di puglia”) l’unità viene descritta come di ambiente marino poco profondo. i nuovi rilevamenti, effettuati nell’area del foglio 471 “irsina” impongono una sostanziale revisione della suddivisione formazionale del complesso dei depositi sabbioso-conglomeratici posti al di sopra della formazione delle argille subappennine. prendendo come esempio emblematico quello dell’area dell’abitato di irsina (località-tipo per l’istituzione della formazione del conglomerato di irsina), e mettendo a confronto il rilevamento effettuato nell’ambito della carta geologica d’italia in scala 1:100.000 con quello effettuato nella stessa area per i rilevamenti del nuovo foglio in scala 1:50.000 risultano infatti notevoli differenze (fig. 13). in particolare, in base ai nuovi rilevamenti si evince come ad irsina siano presenti tre litosomi conglomeratici che non possono essere riuniti in una unica unità formale: un primo litosoma, di spessore ridotto, è rappresentato da conglomerati di avanspiaggia che localmente costituiscono le facies di chiusura di una successione regressiva prevalentemente sabbiosa; un secondo litosoma è rappresentato da un corpo conglomeratico clinostratificato di ambiente deltizio progradante ed in erosione sulla successione sabbioso-conglomeratica precedente e, distalmente, sulle argille; un terzo litosoma è rappresentato da una unità sabbioso-conglomeratica di origine continentale in erosione sulle unità precedenti. nel vecchio rilevamento i tre litosomi discordanti fra loro erano identificati come la formazione del conglomerato di irsina e venivano rappresentati come un unico corpo tabulare, aggradante e in parziale eteropia con la sottostante formazione delle sabbie di monte marano; è evidente da quanto descritto in precedenza che nella formazione venivano erroneamente inclusi depositi che nel nuovo rilevamento vengono riferiti alla locale parte alta della formazione delle sabbie e conglomerati di monte s. marco, al membro del conglomerato di madonna della pietà di irsina e alla formazione delle sabbie e conglomerati di fosso macello, che oltre a possedere caratteri di facies nettamente differenti, si trovano in posizioni stratigrafiche ben distinte. anche nelle altre località rilevate si è riscontrata la presenza di più litosomi conglomeratici, non distinti nella vecchia cartografia. si evince che, regionalmente, nella formazione del conglomerato di irsina erano stati 401problemi di cartografia ... praticamente inclusi tutti i litosomi conglomeratici affioranti (ed anche le successioni sabbiose ad essi intercalate). dall’interpretazione ambientale dei conglomerati si ricava inoltre che la gran parte degli affioramenti osservati non appartiene a corpi che originariamente possedevano eccessiva continuità laterale. quindi la soluzione stratigrafica ricavata localmente e la sua trasposizione cartografica non può essere adottata in maniera semplicistica per tutto il bacino. la tabularità dei depositi riconosciuta a livello regionale riguarda quindi l’assetto tettonico (indeformato) dei depositi regressivi della fossa bradanica, ma non, nel dettaglio, la loro distribuzione stratigrafica areale. in definitiva, non esiste un unico corpo prevalentemente conglomeratico e coevo che chiude la serie bradanica e che possa assumere un rango formazionale e pertanto la formazione del conglomerato di irsina deve essere emendata. conclusioni dal rilevamento geologico e dall’analisi di facies compiuta sui depositi regressivi dell’area del foglio irsina si ricava un modello deposizionale rappresentato da sistemi costieri s.l. (formazione delle sabbie e conglomerati di monte s. marco e membri conglomeratici intercalati) che progradavano nel bacino bradanico poggiando e passando distalmente a depositi emipelagitici (argille subappennine). su questo complesso di depositi marini, una volta esposti, si sviluppavano in erosione sistemi alluvionali (formazione delle sabbie e 402 fig. 12 in alto, schema stratigrafico derivante dalla carta geologica d’italia f° 188 “gravina di puglia” (scala 1: 100.000); in basso, schema stratigrafico derivante dai rilevamenti del f° 471 “irsina” (scala 1: 50.000). stratigraphic schemes of the bradanic trough according to the geological map f° 188 “gravina di puglia” (on scale 1: 100.000) above, and according to the geological map f° 471 “irsina” (on scale 1: 50.000), below. l. sabato, m. tropeano & p. pieri conglomerati di fosso macello). le formazioni così definite sono diacrone in tutto il bacino, ringiovanendosi a sud verso il mare ionio. la formazione del conglomerato di irsina, così come istituita negli anni '60 e nota in letteratura, va emendata, in quanto è un insieme di più litosomi di età e significato ambientale e stratigrafico differente. i dati esposti dimostrano inoltre che i depositi e la superficie sommitale dei rilievi bradanici, a differenza di quanto sostenuto anche recentemente, non rappresentano un episodio unico di regressione, ma una serie di episodi regressivi registrati durante il sollevamento tettonico del bacino. l’organizzazione stratigrafica dei depositi mostra infatti un trend progradazionale piuttosto che aggradazionale. a tale proposito, le quote massime a cui si rinvengono i depositi regressivi della fossa bradanica (da circa 630 m s.l.m., fino a circa 400 m s.l.m. nell'area rilevata spostandosi dalla catena verso e) non va intesa come il risultato di un sollevamento differenziale del bacino successivo alla sedimentazione della successione marina costiera, ma in larga parte come la registrazione del sollevamento regionale in atto durante la sedimentazione. ringraziamenti si ringraziano il prof. n. ciaranfi e il dott. s. longhitano per la lettura critica del manoscritto. il lavoro è stato eseguito nell’ambito del progetto carg, anche con fondi m.i.u.r. anni 2001, 2002 (responsabile prof.ssa sabato). 403 fig. 13 in alto, confronto fra la carta geologica dell’area di irsina nel f° 188 gravina di puglia (a sinistra), e nel f° 471 irsina (a destra). in basso, confronto fra il vecchio e il nuovo schema stratigrafico dei depositi sommitali della fossa bradanica affioranti nella stessa area. above, comparison between the geological map of the irsina area in the f° 188 gravina di puglia (on the left) and in the f° 471 irsina (on the right). below, comparison between the old and the new stratigraphic scheme of the upper deposits of the bradanic trough in the irsina area. problemi di cartografia ... lavori citati azzaroli a., perno u. & radina b. (1968a) note illustrative della carta geologica d'italia alla scala 1:100.000 del foglio 188 "gravina di puglia". serv. geol. d'it., 57 pp. azzaroli a., radina b., ricchetti g. & valduga a. (1968b) note illustrative della carta geologica d’ital ia al la scala 1:100.000 del foglio 189 "altamura". serv. geol. d'it., 22 pp. boenzi f., palmentola g. & valduga a. (1971a) note illustrative della carta geologica d'italia alla scala 1:100.000 del foglio 200 "tricarico". serv. geol. d'it., 46 pp. boenzi f., radina b., ricchetti g. & valduga a. (1971b) note illustrative della carta geologica d'italia alla scala 1:100.000 del foglio 201 "matera". serv. geol. d'it., 48 pp. casnedi r. (1988) la fossa bradanica: origine, sedimentazione e migrazione. mem. soc. geol. it., 41, 439-448. casnedi r. (1991) hydrocarbon accumulation in turbidites in migrating basins of the southern adriatic foredeep (italy). in: bouma & carter (eds.) “facies models”, 219-233. casnedi r., crescenti u. & tonna m. (1982) evoluzione della avanfossa adriatica meridionale nel plio-pleistocene, sulla base di dati di sottosuolo. mem. soc. geol. it., 24, 243-260. ciaranfi n., maggiore m., pieri p., rapisardi l., ricchetti g. & walsh n. (1979) considerazioni sulla neotettonica della fossa bradanica. prog. fin. geod. del cnr, 251, 73-95. cilumbriello a. (2004) caratteri stratigrafici dei depositi regressivi pleistocenici della fossa bradanica nell’area di banzi e genzano di lucania (basilicata). università della basil icata. tesi di laurea, università della basilicata, 90 pp. crescenti u. (1975) sul substrato pre-pliocenico dell'avanfossa appenninica dalle marche allo jonio. boll. soc. geol. it., 94, 583-634. gilbert g.k. (1885) the topographic features of lake shores. u.s. geol. surv., 5th annual rep., 69-123. lazzari m. (1998) evoluzione stratigrafica e paleoambientale della parte sommitale della successione della fossa bradanica fra l'appennino meridionale e le murge settentrionali. considerazioni sull'evoluzione tettonico-sedimentaria del bacino bradanico nel pleistocene inferiore. tesi di dottorato, università di bari, 144 pp. lazzari m. & pieri p. (2002) modello stratigraficodeposizionale della successione regressiva infrapleistocenica della fossa bradanica nell’area compresa fra lavello, genzano e spinazzola. mem. soc. geol. it., 57, 231-237. massari f. & parea g.c. (1988) progradational gravel beach sequences in a moderateto high-energy, microtidal marine environment. sedimentology, 35, 881-913. massari f. & parea g.c. (1990) wave dominated gilbert-type gravel deltas in the interland of the gulf of taranto (pleistocene, southern italy). in: colella & prior (eds.) “coarse-grained deltas” , spec. publs int. ass. sediment., 10, 113-127. migliorini c. (1937) cenno sullo studio e sulla prospezione petrolifera di una zona dell'itala meridionale. ii congr. mondiale del petrolio, parigi, 1-11. pieri p., boenzi f., gallicchio s., sabato l., tropeano m. & vitale g. note illustrative della carta geologica d’italia alla scala 1:50.000 del foglio 471 “irsina”. sottoposto per la stampa su: serv. geol. d'it. pieri p., sabato l. & tropeano m. (1994) evoluzione tettonico-sedimentaria della fossa bradanica a sud dell’ofanto nel pleistocene. in: osanna (ed.) "guida alle escursioni". 77° cong. naz. soc. geol. it., bari. quad. bibl. prov. matera, 15, 35-54. pieri p., sabato l. & tropeano m. (1996) significato geodinamico dei caratteri deposizionali e strutturali della fossa bradanica nel pleistocene. mem. soc. geol. it., 51, 501-515. pieri p., sabato l. & tropeano m. (2004) pliopleistocene stratigraphic and tectonic evolution of the foreland-foredeep-chain system in southern italy . in: memorie descritt ive della carta geologica d’italia, vol. lxiii, field trip guide book, 32nd int. geol. congress, august 20-28 2004, florence (italy), vol. n° 1, p35, 44 pp. ricchetti g. (1965) alcune osservazioni sulla serie della fossa bradanica. le "calcareniti di m. castiglione”. boll. soc. nat. in napoli, 74, 3-11. ricchetti g. (1967) lineamenti geologici e morfologici della media valle del fiume bradano. boll. soc. geol. it., 86, 607-622. ricchetti g. (1980) contributo alla conoscenza strutturale della fossa bradanica e delle murge. boll. soc. geol. it., 49, 421-430. sabato l. (1989) caratteri stratigrafici e sedimentologici dei depositi affioranti nella zona di irsina (fossa bradanica). rapporto interno cnr, ist. ric. argille, 20 pp. sabato l. (1996) quadro stratigrafico-deposizionale dei depositi regressivi nell'area di irsina (fossa bradanica). geologica romana, 32, 219-230. sabato l., tropeano m., cilumbriello a., palladino g. & pieri p. (2004) latest stages of filling of a confined and uplifting foreland basin (bradanic trough, southern italy). in: abstracts 32nd int. geol. cong., florence (italy), august 20-28, part 1, 697. selli r. (1962) il paleogene nel quadro della geologia dell’italia meridionale. mem. soc. geol. it., 3, 737789. tropeano m., sabato l., pieri p. (2002a) filling and cannibalization of a foredeep: the bradanic trough, southern italy. in: jones & frostick (eds.) “sediment flux to basins: causes, controls and consequences” , geological society, london, spec. publ., 191, 55-79. tropeano m., sabato l., pieri p. (2002b) the quaternary “post-turbidite” sedimentation in the south apennines foredeep (bradanic trough southern italy). boll. soc. geol. it., vol. sp. n° 1, parte i, 449-454. valduga a. (1973) fossa bradanica. in: utet (ed.) “geologia dell'italia”. a cura di a. desio, 692-695. vezzani l. (1967) i depositi plio-pleistocenici del litorale ionico della lucania. atti acc. gioenia sc. nat. in catania, s. vi, 18, 159-180. 404 ms. ricevuto il 21 maggio 2004 testo definitivo ricevuto l’8 ottobre 2004 ms. received: may 21, 2004 final text received: october 8, 2004 l. sabato, m. tropeano & p. pieri imp.giannadrea-loiacono llee ssuucccceessssiioonnii aalllluuvviioonnaallii ee llaaccuussttrrii qquuaatteerrnnaarriiee aaffffiioorraannttii nneellllaa mmeeddiiaa vvaallllee ddeell ffiiuummee ssiinnnnii ((aappppeennnniinnoo mmeerriiddiioonnaallee,, bbaassiilliiccaattaa)) ppaaoolloo ggiiaannnnaannddrreeaa,, ffrraanncceessccoo llooiiaaccoonnoo dipartimento di geologia e geofisica, università di bari riassunto le successioni alluvionali e lacustri quaternarie affioranti nella media valle del fiume sinni (appennino meridionale, basilicata) la media valle del fiume sinni, attraversa il settore meridionale del bacino di sant’arcangelo localizzato nel settore esterno dell’appennino meridionale. lungo i suoi versanti e quelli dei suoi maggiori affluenti (fiumi sarmento e torrente serrapotamo) è possibile osservare due successioni sedimentarie quaternarie, legate a due differenti fasi evolutive. la prima mostra i caratteri di un bacino subsidente, progressivamente colmato da depositi continentali, mentre la seconda comprende i terreni appartenenti a più ordini di terrazzi. questi ultimi, formati nella successiva fase di sollevamento dell’area dal pleistocene medio al pleistocene superiore, si presentano a diverse quote rispetto al fondovalle attuale. la prima successione, spessa più di 2.500 m, comprende i terreni riferiti al bacino di s. arcangelo (bsa), suddivisi in unità stratigrafiche a limiti inconformi (ubsu). le unità distinte, vengono raggruppate nei supersintemi di m. cotugno (smc, pliocene superiore), del sinni (ss, pliocene superiore – pleistocene inferiore) e del serrapotamo (ssp, pleistocene inferiore-medio). il più antico (smc), discordante sul substrato pre-pliocenico, è costituito in gran parte da facies pelitiche di piattaforma. il ss consiste in una spessa successione di sequenze arenacee di fronte deltizia e, nella sua parte superiore marginale, sistemi alluvionali e lacustri. questi ultimi si sviluppavano nell’area pedemontana lungo il margine sud-occidentale del bsa. la successione termina con il ssp costituito da depositi continentali, riferiti a sistemi di fan-delta lacustre, passanti in alto a sistemi di piana alluvionale di tipo braided, i cui depositi si sviluppano in gran parte del bacino con uno spessore di poche decine di metri. la seconda successione si sviluppa a tetto di una superficie erosiva modellata sui conglomerati alluvionali del ssp. tale successione viene suddivisa in due supersintemi, di cui il più alto (supersintema del bosco di farneta, sbf, pleistocene medio) comprende due unità terrazzate indicanti un paleo-deflusso verso i quadranti settentrionali. il successivo supersintema del fosso manga ramelle (smr), invece, comprende una serie di terrazzi riferiti ai bacini idrografici dei fiumi sinni e sarmento. il quadro stratigrafico che ne deriva è il risultato della combinazione delle variazioni eustatiche e dei movimenti tettonici che hanno interessato il settore esterno dell’appennino meridionale. abstract alluvial and lacustrine quaternary successions in the middle valley of sinni river (southern apennine, basilicata) – thick terrigenous successions, mainly quaternary in age, crop out in the middle valley of sinni river (southern apennines). two main successions are distinguished: the lower one, pliocene to middle pleistocene in age, belongs to the southern part of bsa and shows a general regressive trend (marine to continental). the upper one, middle pleistocene to holocene in age, consists of alluvial deposits referred to terraced stages of fluvial overcutting. the bsa succession, was divided in the following three supersynthems: the oldest monte cotugno supersynthem (smc, upper pliocene), overlies unconformably the pre-pliocene substratum; it is mainly composed of fine-grained shelf sediment. the sinni supersynthem (ss, late pliocene – lower pleistocene) consists of thick marine delta sandstone lobes passing upward to alluvial-lacustrine deposits well cropping out in the south-western part of the area. the uppermost serrapotamo supersynthem (ssp, lower-middle pleistocene) consists of alluvial and lacustrine systems underlying a tabular coarse-grained body, a few ten meters thick and widely extended, interpreted as a braid plain system. an erosional surface divides the bsa succession from the terraced units. in these units two different supersynthems are distinguished. the first one (bosco farneta supersynthem, sbf), located in the highest terraces, consists of alluvial deposits showing a northward palaeoflow. the second one (fosso manga ramelle supersynthem, smr), at different heights, consists of alluvial terraced deposits, referred to the drainage basins of sinni and sarmento rivers. the stratigraphic setting results from the interaction of eustatic changes and tectonic uplift of the eastern sector of southern apennines during pleistocene. parole chiave: stratigrafia del quaternario; appennino meridionale; analisi di bacino; discordanze stratigrafiche; supersintemi. keywords: quaternary stratigraphy; southern apennines; basin analysis; unconformity; supersynthem. il quaternario italian journal of quaternary sciences 1166(2), 2003, 257-267 11.. iinnttrroodduuzziioonnee il fiume sinni attraversa in gran parte l’appennino meridionale da ovest verso est. nel tratto inferiore dopo aver inciso profondamente la dorsale esterna dell’appennino (dorsale di valsinni) il fiume percorre, con un ampia deviazione verso se, il settore interno dell’avanfossa bradanica prima di sfociare nel mare ionio all’altezza di policoro. nel tratto intermedio il fiume sinni e i suoi maggiori affluenti, fiume sarmento e torrente serrapotamo, attraversano il settore meridionale del bacino plio-pleistocenico di sant’arcangelo (vezzani, 1967), che rappresenta una depressione tettonica delimitata a so dal massiccio del pollino, dal monte alpi e monte raparo e a ne dalla dorsale di valsinni, che separa il bsa dall’avanfossa bradanica (fig.1). le successioni conglomeratiche ed argilloso-sabbiose che hanno colmato il bsa e numerose unità terrazzate sospese rispetto al fondovalle attuale, sono ben visibili lungo le valli principali. le buone condizioni di affioramento consentono di ricostruire, per la presenza 258 p. giannandrea & f. loiacono di diverse discontinuità, un dettagliato quadro stratigrafico con unità a limiti inconformi (salvador, 1987; 1994) che rappresenta l’oggetto del presente lavoro. la sovrapposizione delle unità terrazzate sulla successione sedimentaria del bsa, rende quest’area di notevole interesse per la ricostruzione dell’evoluzione morfostrutturale e sedimentaria del fronte esterno dell’appennino lucano. pertanto lo studio stratigrafico ha interessato sia i terreni del bsa che quelli terrazzati, le cui correlazioni sono state effettuate in tre profili morfostratigrafici rettificati, di cui due paralleli all’asse dei fiumi sinni e sarmento e uno trasversale. 22.. iinnqquuaaddrraammeennttoo ggeeoollooggiiccoo rreeggiioonnaallee la catena sud-appenninica è costituita da più unità tettoniche impilate con vergenza adriatica (sella et al., 1992; casero et al., 1992) sovrapposte a un thrust belt sepolto, costituito da carbonati mesozoico-terziari della “piattaforma apula interna”. l’insieme delle strutture menzionate forma geometrie a duplex (finetti et al., 1996; patacca & scandone, 2001). lungo il margine esterno della catena, durante il plio-pleistocene, si registra una intensa mobilità tettonica di tipo compressionale che determina la progressiva separazione del bsa dall’avanfossa bradanica. il bsa viene interpretato sia come bacino di tipo pull-apart (turco et al., 1990), in cui il bsa si apre per effetto di una zona di taglio trascorrente sinistra diretta no-se (“faglia di montesano”), sia come piggy-back basin (caldara et al, 1988; 1992; hippolytte et al., 1991; 1994). in questa seconda interpretazione i diversi autori, sia pure con alcune differenze, considerano il bsa impostato sulle coltri appenniniche in concomitanza con la crescita dell’anticlinale di rampa di tursi-rotondella, con migrazione del depocentro sedimentario da oriente verso occidente per progressivo tilt sin-deposizionale. un’altra interpretazione viene fornita da patacca & scandone (2001), che considerano piggy-back basin solo la parte alta della successione sedimentaria del bsa, mentre i termini più antichi si sarebbero deposti sulle coltri appenniniche in un bacino aperto verso l’avanfossa. nel pleistocene medio, dopo il colmamento del bsa, l’intera regione subisce un cambiamento nell’evoluzione geodinamica (ciaranfi et al., 1983 e doglioni et al., 1996): le aree precedentemente in subsidenza iniziano a sollevarsi. contemporaneamente nel bsa si assiste ad una variazione nel regime tettonico, con passaggio dallo stile compressivo a quello distensivo (pieri et al., 1997) e alla formazione delle unità terrazzate. il bsa, quindi, rappresenta un buon esempio in cui è possibile studiare le relazioni esistenti fra tettonica e sedimentazione. in esso sono stati eseguiti diversi studi di carattere stratigrafico (tab. 1) di cui i primi risalgono agli anni sessanta (vezzani, 1966; 1967; 1968, lentini, 1967; ogniben, 1969). in questi lavori la successione sedimentaria del bsa viene suddivisa in due cicli (ciclo pliocenico di caliandro e ciclo suprapliocenico-infrapleistocenico), separati da una superficie erosiva. a tetto della successione si r iconoscono le sabbie e conglomerati della serra corneta che restano, pur separati da una superficie erosiva, accorpati al ciclo superiore. il ciclo plio-pleistocenico, in lavori eseguiti a nord della valle del fiume agri (caldara et al., 1988; 1992; pieri et al., 1994), viene successivamente suddiviso in più unità stratigrafico-deposizionali. le ricerche nel bsa si intensificano tra il 1996 e il 2002 ad opera di diversi gruppi di ricerca. in questi ultimi lavori (zavala & mutti, 1996; zavala, 2000; patacca & scandone , 2001; loiacono & giannandrea, 2001) i diversi autori (tab. 1) pur realizzando suddivisioni differenti per denominazione stratigrafica e per gerarchia dei limiti formazionali, individuano più discontinuità utili per una suddivisione stratigrafica a limiti inconformi e separano l’unità delle sabbie e conglomerati di serra corneta dalla successione di terreni attribuiti al bsa. 33.. ssttrraattiiggrraaffiiaa la ricostruzione stratigrafica è stata realizzata attraverso un dettagliato rilevamento geologico e l’analisi di numerose sezioni stratigrafiche, che hanno consentito l’interpretazione sedimentologica dei depositi e il riconoscimento di discontinuità. le unità distinte sono state raggruppate in due successioni stratigrafiche, che sintetizzano l’evoluzione sedimentaria dell’area. la più fig. 1 carta geologica schematica del settore esterno dell’appennino meridionale, con ubicazione della valle del sinni e dell’area di studio. schematic geological map of the southern apennines, and location of sinni valley and the studied area. 259le successioni alluvionali e lacustri quaternarie ... tab. 1 nomenclatura stratigrafica del bsa e correlazioni tra lavori precedenti. stratigraphic nomenclature of bsa and correlations. tab. 2 schema stratigrafico delle successioni marine e continentali affioranti nella media valle del fiume sinni. stratigraphic scheme of marine and continental units in the middle sinni valley. antica (pliocene superiore – pleistocene medio) riflette la fase subsidente, di un bacino progressivamente colmato con depositi continentali (alluvionali e lacustri) (loiacono & giannandrea, 2001). la seconda successione (pleistocene medio – superiore) comprende i terreni appartenenti a più ordini di terrazzi alluvionali (tab. 2), visibili a quote differenti rispetto agli alvei attuali dei fiumi sinni e sarmento. nella suddivisione operata, i limiti di rango superiore sono stati assegnati a discontinuità legate a eventi che hanno sensibilmente modificato forma e dimensione del bacino. tali limiti, pertanto, non solo consentono di ricostruire le tappe fondamentali dell’evoluzione tettonostratigrafica dell’area, ma sono tracciabili anche a scala regionale, nell’intera area del bacino bradanico. 260 33..11.. bbaacciinnoo ddii ssaanntt’’aarrccaannggeelloo la successione sedimentaria attribuita a questo bacino ha una età compresa fra il pliocene superiore e il pleistocene medio (tab. 2) ed è costituita da depositi di ambiente marino in transizione a quelli di ambiente continentale (fig. 2). i depositi marini sono distribuiti lungo il margine nord-orientale in un’ampia fascia orientata in direzione no-se, mentre quelli continentali prevalgono nella metà sud-occidentale. in recenti studi questi depositi, spessi circa 2.500 m, sono stati suddivisi in unità stratigrafiche a limiti inconformi (zavala, 2000; patacca & scandone, 2001; loiacono & giannandrea, 2001) e raggruppabili nei supersintemi di monte cotugno (smc), del sinni (ss) e del serrapotamo (ssp) (tab. 2). il smc (1 di fig. 2), con una età riferita al pliocene superiore (lentini, 1967; marino, 1992; 1994) e uno spessore di circa 900 m, rappresenta il termine più antico della successione sedimentaria del bsa. esso affiora lungo il margine nord-orientale ed è costituito da argille grigio-azzurre di piattaforma, poggianti con una superfifig. 2 carta geologica schematica del settore meridionale del bsa. schematic geological map of the southern part of bsa. p. giannandrea & f. loiacono 261 cie di "maximum flooding" su depositi sabbioso-conglomeratici di ambiente deltizio, osservati in limitati lembi di pochi metri in corrispondenza della diga di monte cotugno e interpretabili come termini trasgressivi sulle coltri appenniniche. le argille di piattaforma presentano nella parte superiore, per uno spessore di alcune decina di metri, sequenze cicliche trasgressivo-regressive, caratterizzate alla base da strati biodetritici, interpretati come eventi di sedimentazione condensata. la parte superiore del supersintema è caratterizzata da un sensibile incremento di facies arenacee. il ss (fig. 2) (pliocene superiore pleistocene inferiore), comprende una successione spessa oltre 1.200 m, costituita da facies sabbiose di fronte deltizia e da facies conglomeratico-sabbioso-siltose, interpretate come parti prossimali di fan-delta marini ed elementi deposizionali di sistemi pedemontani alluvionali e lacustri. la superficie di separazione con il sottostante smc è di tipo discordante erosivo ai margini del bacino e paraconcordante nel settore depocentrale. in questo secondo caso il limite è marcato dalla presenza di un corpo sabbioso deltizio prossimale intercalato ad argille grigio-azzurre di prodelta, esteso lateralmente e presente in tutta l’area compresa fra i fiumi sinni e agri. il ss è stato suddiviso nei sintemi di senise e noepoli. il primo (sintema di senise) segna l’inizio della strutturazione di un bacino allungato in direzione all'incirca n-s in cui si accumulano sedimenti alluvionali e deltizi per uno spessore di circa 600 m. in questa fase si sono distinti “sistemi deltizi” caratterizzati da alimentazione puntiforme e ciclica dai quadranti orientale (sistema di s. giorgio lucano), meridionale (sistema di cersosimo) ed occidentale (sistema di senise). il sistema di cersosimo é costituito da conglomerati massivi clasto-sostenuti, con clasti che raggiungono il metro di diametro (litofacies 2a, fig. 2). tali conglomerati sono interpretati come la parte sub-aerea di un ampio fandelta marino formato lungo un margine ripido e attivo tettonicamente. i sistemi di senise e di sangiorgio sono costituiti, invece, da una spessa successione di corpi sabbioso-siltoso-argillosi, con a luoghi conglomerati canalizzati, organizzati in sequenze coarsening upward (cu) spesse fino a 60 m. tali sequenze mostrano i tipici caratteri di un sistema deltizio in cui è possibile distinguere facies di prodelta, di fronte deltizia prossimale, distale e di piana deltizia. nel sintema di noepoli, spesso circa 400 m, separato dal sottostante sintema di senise da una marcata superficie erosiva, prevalgono le facies alluvionali e lacustri (litofacies 3a e 3b, fig. 2), mentre quelle marine (litofacies 3c, fig. 2) sono confinate in una stretta fascia nel settore nord di figura 2. le facies conglomeratiche presenti lungo il margine meridionale del bacino, individuano conoidi alluvionali (litofacies 3a, fig. 2) progradanti verso nord, dove sono in transizione con ambienti di piana alluvionale (litofacies 3b, fig. 2). questi sono rappresentati da argille e sabbie laminate, con intercalazione di conglomerati canalizzati, indicanti paleoflussi in direzione n-o. simili associazioni di facies (litofacies 3b, fig. 2) si rinvengono nel settore compreso fra il fiume sinni e il torrente serrapotamo (fig. 2); in questo secondo caso le misure di paleocorrente indicano apporti dai quadranti occidentali. la transizione alle facies marine (litofacies 3c, fig. 2) si osserva a nord del torrente serrapotamo. il contatto con il sovrastante supersintema del serrapotamo (pleistocene inferiore – pleistocene medio), rappresentato da una marcata discontinuità nell’ambito di facies alluvionali, coincide con una intensa attività tettonica responsabile del sollevamento della dorsale di valsinni. la fase tettonica determina la definitiva separazione del bsa dal bacino di avanfossa, il basculamento verso s-o dei terreni appena sedimentati e la migrazione nella stessa direzione del depocentro sedimentario (fig. 3). con la separazione del bsa, lungo il suo margine sud-occidentale, si formano blande sinclinali e si riattivano faglie marginali nel settore sud-orientale. in queste condizioni si sedimenta il ssp, suddiviso nei sintemi di francavilla e di chiaromonte (tab. 2, fig. 2 e 4). il sintema di francavilla, spesso circa 300 m, occupa due aree depocentrali localizzate una a nord del torrente serrapotamo e l’altra fra i fiumi sinni e sarmento. fig. 3 – sezione geologica schematica (vedi figura 2 per ubicazione) attraverso la valle del sinni: sono visibili le principali strutture marginali, i rapporti tra le principali unità stratigrafiche e le associazioni di facies più significative. schematic cross-section (location in fig. 2) of bsa in the sinni sector showing the main marginal tectonic structures, the relationship between main units and the lithofacies associations. le successioni alluvionali e lacustri quaternarie ... 262 entrambi i sub-bacini sono colmati da sedimenti lacustri, che mettono in evidenza le aree depocentrali, e da conglomerati di conoide alluvionale nelle aree marginali. le litofacies fini sono costituite prevalentemente da argillesiltoso-sabbiose sottilmente laminate, con a luoghi abbondanti resti vegetali. il sintema di chiaromonte (5) (fig. 2; tab, 2), sovrapposto al primo è costituito da un corpo tabulare di conglomerato alluvionale (piana braided), molto esteso lateralmente, dello spessore medio di 60 m. il conglomerato si presenta massivo con stratificazione interna incrociata concava. i ciottoli sono moderatamente embriciati. le misure di paleocorrente indicano un generale apporto da se verso no in accordo con l’orientazione del bacino. i rapporti stratigrafici fra i sintemi di chiaromonte, francavilla, noepoli e senise sono ben visibili lungo il versante sinistro del fiume sarmento (fig. 4). in questo settore si osserva una sinclinale strutturata nei sintemi di noepoli e senise nel cui centro sono presenti i depositi lacustri e alluvionali del sintema di francavilla, fino al colmamento della sinclinale. superiormente è presente un corpo tabulare appartenente al sintema di chiaromonte, in rapporto discordante sul substrato prepliocenico e sul sintema di noepoli e paraconcordante sul sintema di francavilla. la superficie di tetto costituisce la superficie deposizionale di colmamento del bsa. il corpo tabulare, infine, è interessato, a luoghi, da una marcata superficie erosiva sul quale poggia il sintema di serra corneta. fig. 4 – profilo schematico (vedi figura 2 per ubicazione) e foto panoramiche del settore sud-occidentale del bsa in corrispondenza dello spartiacque sinni-sarmento. sono visibili i rapporti tra le unità più recenti del bsa. si notano anche le discontinuità progressive nell’unità di noepoli, la struttura sinclinale e i rapporti tra il sintema di noepoli e il ssp (rappresentato dai sintemi di francavilla e chiaromonte) e il sintema di serra corneta. cross section through south-western sector of the studied area, showing the relationship between the uppermost units (location in fig.2). note the compressional structure in the noepoli synthem and the unconformity between the noepoli, francavilla and chiaromonte synthems. at the top it is also visible the serra corneta synthem. in a and b pictures panoramic views of the geometric relationships between the uppermost synthems. p. giannandrea & f. loiacono 33..22.. uunniittàà aalllluuvviioonnaallii tteerrrraazzzzaattee sulla successione sedimentaria del bsa, lungo i fiumi sinni e sarmento, sono presenti numerosi terrazzi alluvionali riconducibili a più fasi di modellamento e deposizione (fig. 5). la maggior parte dei terrazzi si concentrano nel settore nord-orientale del bsa in cui affiorano i terreni argilloso-sabbiosi, facilmente erodibili, mentre sul versante meridionale ed occidentale sono visibili solo i terreni del sintema di serra corneta posizionato tra 720 m 263 fig. 5 – carta geologica schematica in cui vengono distinte le unità alluvionali terrazzate dei fiumi sinni e sarmento. schematic geological map of the alluvial terraced units in the sinni and sarmento valley. le successioni alluvionali e lacustri quaternarie ... e 1.000 m s.l.m., a tetto del sintema di chiaromonte (fig. 4). le correlazioni stratigrafiche sono state realizzate in tre profili morfostratigrafici, di cui due paralleli all’asse dei fiumi sinni e sarmento e uno trasversale (fig. 6). l’analisi dei due profili longitudinali mostra un fondovalle digradante da so verso ne da quota 380 m a 150 m s.l.m. per il fiume sinni, e da 520 m a 150 m s.l.m. per il fiume sarmento. inoltre, dall’analisi comparata delle figure 5 e 6 si deduce che le valli dei due fiumi cominciano a separarsi durante la fase di modellamento successiva alla formazione del terrazzo di piano delle rose (compreso tra quota 510 m e 420 m s.l.m). pertanto nella suddivisione stratigrafica operata (tab. 2), si raggruppano i terrazzi presenti all’interno delle due valli nel supersintema di manga ramelle (smr), distinti per bacino di pertinenza, mentre quelli ubiquitari vengono raggruppati nel supersintema di bosco di farneta (sbf) (sintemi di serra corneta e di piano delle rose). il sintema di serra corneta, corrispondente alle “sabbie e conglomerati di serra corneta” di vezzani, (1967), è separato dalla sottostante unità da una evidente superficie erosiva (fig. 4). nel complesso l’unità è costituita da facies conglomeratiche e sabbioso-siltose, organizzate verticalmente in sequenze fining upward (fu), di ambiente alluvionale, in cui si distinguono nei settori meridionali facies di conoide alluvionale prossimale ed intermedia passante verso nord a depositi di piana alluvionale (celentano, 1998). le paleocorrenti indicano apporti da sud e da ovest con deflusso verso i quadranti settentrionali. l’unità raggiunge uno spessore massimo di circa 100 m e contiene internamente diverse superfici di erosione e paleosuoli rossastri, indicativi di fluttuazioni climatiche in cui si alternavano fasi con buona piovosità e con una stagione caldo arida a fasi con clima semiarido-arido, durante il quale potevano formarsi paleosuoli rossastri (amato & dimase, 1997). la superficie sommitale del sintema appare modellata da una fase erosiva, che ha determinato il formarsi di plateaux rapportabili ad una superficie sub-pianeggiante, sospesa fino a 550 m sui fondovalle attuali (amato & dimase, 1997). l’erosione ha agito maggiormente nei settori nordorientali del bsa, in cui prevalgono le facies argillose, formando una vasta superficie leggermente inclinata verso i quadranti nord-orientali. in questo settore, superiormente alla superficie di modellamento, si distingue il sintema di piano delle rose, costituito da sabbie siltose rossastre prive di strutture interne, per uno spessore di 3 m circa. tale unità visibile in corrispondenza dello spartiacque dei bacini del fiumi sinni e sarmento è riferibile ad una unica piana alluvionale (fig. 6). l’evoluzione successiva dell’area porta alla formazione del smr il quale comprende i sintemi di san giorgio lucano e di rosaneto. il sintema di san giorgio 264 fig. 6 – profili morfostratigrafici longitudinali e trasversali delle valli dei fiumi sinni e sarmento. longitudinal and trasversal morphostratigraphic profiles of sinni and sarmento valley. p. giannandrea & f. loiacono lucano raggruppa i terrazzi formati nelle prime fasi di evoluzione delle due valli, iniziata nel settore nord-orientale del bsa (fig. 5; fig. 6). lungo il fiume sarmento il sintema raggruppa i subsintemi di timpa selvavecchia a quota 405 m s.l.m e il subsintema di falconeto rilevato tra 380 m e 300 m s.l.m., entrambi costituiti da conglomerati sabbiosi massivi e con lieve stratificazione interna, organizzati in sequenze fu. lungo il fiume sinni, invece, il sintema di san giorgio lucano comprende solo il subsintema di piano codicino, tra 370 m e 300 m s.l.m., costituito da sabbie siltose laminate, con conglomerato matrice-sostenuto e stratificazione incrociata e piano parallela. il successivo sintema di rosaneto (fig. 6) raggruppa i terrazzi presenti lungo l’intero tratto esaminato dei due fiumi, sviluppati in valli più estese verso monte a causa dell’erosione regressiva. il sintema raggruppa: • lungo il fiume sarmento, i subsintema di carpino, tra quota 550 m e 210 m s.l.m, e di canale del ferro, tra 310 m e 202 m s.l.m. • lungo il fiume sinni, i subsintemi di san filippo, tra quota 410 m e 245 m s.l.m., e di galilea, tra quota 385 m e 235 m s.l.m. i subsintemi sono costituiti da conglomerati massivi oppure con stratificazione interna incrociata concava. 44.. eevvoolluuzziioonnee mmoorrffoossttrraattiiggrraaffiiccaa ee iimmpplliiccaazziioonnii tteettttoonniicchhee il quadro stratigrafico prospettato in tabella 2 consente di ricostruire le tappe fondamentali dell’evoluzione paleogeografica e tettonica dell’area studiata. inizialmente, nel pliocene superiore, l’area era completamente emersa, con un limitato alto morfologico posizionato in corrispondenza dell’attuale dorsale di valsinni. la sedimentazione nel bsa ha inizio nel pliocene (fig. 7a) superiore: sul settore esterno del bacino si impostò inizialmente un sistema deltizio, alimentato da ne, che venne rapidamente disattivato a seguito del sollevamento del livello del mare. questo determinò la sommersione dell’alto di valsinni e la deposizione, lungo il suo margine sud-occidentale, delle argille grigioazzurre. la sedimentazione, inizialmente di tipo retrogradazionale diventò successivamente di tipo aggradazionale. solo nella parte alta del smc, per qualche decina di metri, le frequenti oscillazioni del livello di base determinarono eventi di sedimentazione litorale. il bsa in questa fase doveva essere aperto verso l’avanfossa sia ad est che a sud, in direzione dell’attuale mare ionio. il passaggio al ss coincise con profonde modifica265 fig. 7 – schemi paleogeografici dell’evoluzione morfo-stratigrafica del settore meridionale del bsa palaeogeographic sketches indicating the morfo-stratigraphi evolution phases of the southern part of bsa. le successioni alluvionali e lacustri quaternarie ... zioni morfologiche del bacino, per il sollevamento del tratto sud-orientale della dorsale di valsinni (fig. 7b). contemporaneamente nel bacino si registrò un abbassamento del livello del mare e sul margine meridionale e sud-orientale si attivarono faglie marginali a movimento prevalentemente diretto (fig. 2; fig. 7a). il ss inizia con la sedimentazione di un corpo sabbioso deltizio nel settore depocentrale del bacino. il graduale progredire verso nord del sollevamento della dorsale di valsinni e l’intensa attività tettonica registrata lungo il margine meridionale, favorirono nel bacino forti accumuli di depositi deltizi ed alluvionali, che colmarono lo spazio a disposizione. conseguentemente si registrò la progradazione delle facies continentali su quelle marine, accompagnata dalla migrazione verso nord della linea di costa (fig 7c): si generò una discontinuità riconoscibile a scala di bacino che consente di dividere il ss nei sintemi di senise e di noepoli. la completa emersione della dorsale esterna seguita dal tilt verso sud-ovest dei terreni del bsa, appena sedimentati (fig. 2), determinarono il formarsi di ristrette aree subsidenti lungo il margine sud-occidentale, in cui si concentrò la sedimentazione del ssp. l’architettura delle litofacies e la presenza, a tetto dell’unità, di un corpo conglomeratico spesso poche decine di metri ed esteso lateralmente, consente di suddividere il ssp nei sintemi di francavilla e di chiaromonte: il primo è costituito da depositi alluvionali e lacustri, con rapporti di facies di tipo progradazionale (fig. 7d), il secondo da depositi alluvionali di piana braided, con paleo-trasporto verso i quadranti settentrionali (fig.7e). il corpo tabulare molto esteso arealmente, costituente il sintema di chiaromonte, è indice di una forte riduzione della subsidenza e di una progradazione che preannuncia la fase di colmamento del bacino. infatti lo sviluppo prossimale-distale delle facies ghiaiose e sabbioso-siltose può essere condizionato da una riduzione della subsidenza nel settore prossimale, che favorirebbe la progradazione dei corpi ghiaiosi (heller & paola, 1992). con il sintema di chiaromonte termina la subsidenza dell’area ed inizia la fase successiva, caratterizzata dal progressivo sollevamento dell’intera regione durante il quale si alternarono periodi di modellamento a periodi deposizionali. la prima fase erosiva si sviluppò a tetto dei conglomerati di chiaromonte; a questa seguì la sedimentazione del sintema di serra corneta (fig. 7f), costituito da depositi alluvionali indicanti un paleo-trasporto fluviale verso i quadranti settentrionali. la successiva fase di modellamento agì maggiormente nel settore nord-orientale del bsa, dove si formò una vasta superficie erosiva digradante verso nord, impostata sulle argille grigioazzurre più facilmente erodibili. in questo settore si è distinto il sintema di piano delle rose (fig. 7g)compreso, insieme al precedente sintema, nel sbf. in questo periodo la valle del fiume sinni probabilmente era limitata al solo versante nord-orientale della dorsale di valsinni. il passaggio al successivo smr è legato allo sviluppo del reticolo idrografico del fiume sinni che con un processo di erosione regressiva e sovraimposizione, incide tutta la dorsale di valsinni fino a raggiungere i terreni del bsa. in questo momento iniziano a formarsi le unità terrazzate indicanti un paleo-drenaggio in direzione nord-est, lungo gli alvei dei fiumi sinni e sarmento. lo sviluppo di questi terrazzi comincia nel settore nordorientale del bsa (fig. 7h)e prosegue verso sud-ovest (fig. 7i) a seguito del progressivo arretramento erosivo dei versanti. bbiibblliiooggrraaffiiaa amato a. & dimase a.c., (1997) – caratteristiche paleoambientali ed evoluzione geomorfologica dei plateaux della media valle del fiume agri (basilicata). il quaternario,italian journal of quaternary sciences, 1100, 213-230. caldara m., loiacono f., morlotti e., pieri p. & sabato l. (1988) – caratteri geologici e paleoambientali dei depositi plio-pleistocenici del bacino di sant'arcangelo (parte settentrionale); italia meridionale. atti del 74° congresso della soc. geol. it. vol b, 51-58. caldara m., loiacono f., morlotti e., pieri p. & sabato l. (1992) – i depositi pliopleistocenici della parte nord del bacino di sant’arcangelo (appennino lucano): caratteri geologici e paleoambientali. mem. soc. geol. it., 4411, 391-410. casero p., roure f., endignoux l., moretti i., muller c., sage l., & vially r. (1992) – neogene geodynamic evolution of the southern apennines. mem. soc.geol. it. 4411, 109-120. celentano a.l. (1998) – evoluzione sedimentaria del bacino di sant’arcangelo, parte meridionale (appennino meridionale). tesi di dottorato, università degli studi di bari, ciclo di studi 1995/98, 92 pp. ciaranfi n., ghisetti f., guida m., iaccarino g., lambiase s., pieri p., rapisardi l., ricchetti g., torre m., tortorici m. & vezzani l., (1983) – carta neotettonica dell’italia meridionale. prog. fin. geod. del c.n.r., pubbl. n° 551155, 62 pp. doglioni c., tropeano m. mongelli f. & pieri p., (1996) – middle-late pleistocene uplift of puglia: an <<anomaly>> in the apenninic foreland. mem. soc. geol. it. 5511, 101-117. finetti i., lentini f., carbone s. catalano & del ben a., (1996) – il sistema appenninico meridionale – arco calabro – sici l ia nel mediterraneo centrale:studio geologico-geofisico. boll. soc. geol. it., 111155, 529-559 heller p.l. & paola c. (1992) – the large-scale dynamics of grain-size variation in alluvional basins, 2 : application to syntectonic conglomerate. basin res., 44, 91-102. hippolyte j.c. , angelier j., roure f. & müller c. (1991) – géométrie et méccanisme de formation d’un bassin “piggyback”: le bassin de sant’arcangelo (italie méridionale).c.r. acad. sci. paris, 331122, sséérriiee iiii, 1373-1378. hippolyte j.c. , angelier j., roure f. & casero p. (1994) – piggyback basin devolopment and thrust belt evolution: structural and paleostress analyses of plio-quaternary basin in the southern apennines. jour. struct. geol., 1166, 159-173. lentini f. (1967) – le successioni stratigrafiche pliopleistoceniche sui due lati della dorsale nocaracolobraro (matera). atti acc. gioenia sc. nat. catania, 1188, 181-206, loiacono f. & giannandrea p. (2001) – sedimentary 266 p. giannandrea & f. loiacono evolution of a marginal plio-pleistocene basin along the southern-eastern apennine sector. riunione di lavoro progetto crop – crosta profonda; sottoprogetto crop 04 – appennino meridionale; riassunti, 18-20. marino m. (1992) – biostratigrafia integrata a nannofossili calcarei e foraminiferi planctonici di alcune successioni terrigene plio-pleistoceniche di avanfossa (bacino di s. arcangelo e margine appenninico della fossa bradanica-italia meridionale). tesi di dottorato, università degli studi di bari, 1992, 125pp marino m. (1994) – biostratigrafia integrata a nannofossili calcarei e foraminiferi planctonici di alcune successioni terrigene plioceniche del bacino di s'arcangelo (appennino meridionale). boll. soc. geol. it., 111133, 329-354. ogniben l. (1969) – note illustrative del f° 211, “s.arcangelo”. serv. geol.d’it., roma, 80 pp. patacca e. & scandone p. (2001) – late thrust propagation and sedimentary response in the the thrustbelt-foredeep system of the southern apennines (pliocene-pleistocene). in: vai g.b. & martini i.p. eds., anatomy of an orogen:the apennines and adjacent mediterranean basins. 401-440. kluwer accademic publishers pieri p., sabato l., loiacono f. & marino m. (1994) – il bacino di piggyback di sant’arcangelo: evoluzione tettonico-sedimentaria. boll. soc. geol. it., 111133, 465-481. pieri p., vitale g., beneduce p., doglione c., gallicchio s., giano s.i., loizzo r., moretti m., prosser g., sabato r., schiattarella m., tramutoli m. & tropeano m. (1997) – tettonica quaternaria nell’area bradanico-ionica. il quaternario, 1100, 535542. salvador a. (1987) – unconformity-bounded stratigraphic units. geological society american bulletin, 9988:: 232-237. salvador a. (ed) (1994) – international stratigraphic guide. international union of geological sciences, trondheim, norway, and geological society of america, boulder, 214 pp. sella m., turci c. & riva a. (1992) – sintesi geopetrolifera della fossa bradanica (avanfossa della catena appenninica meridionale). mem. soc. geol. it., 4411, 87-107. turco e., maresca r. & cappadona p. (1990) – la tettonica plio-pleistocenica del confine calabro-lucano : modello cinematico. mem. soc. geol. it., 4455, 519-529. vezzani l. (1966) la sezione stratigrafica di caliandro nel pliocene medio-inferiore della val d’agri (lucania). riv. it. pal. strat. milano, 7722, n. 1, 191229, 72, n.2, 461-488, vezzani l. (1967) il bacino plio-pleistocenico di s. arcangelo (lucania). atti ac. gioenia sc. nat. catania, s. 6a, 1188, suppl. sc. geol., 207-227. vezzani l. (1968) geologia della tavoletta castronuovo di s. andrea (prov. di potenza, f. 211, iv-se). att. acc. gieoenia sc. nat. catania, s. vi, 1199 (suppl. sc. geol.), 9-108. zavala c. (2000) – stratigraphy and sedimentary history of the plio-pleistocene sant’arcangelo basin, southern apennines, italy. rivista italiana di paleontologia e stratigrafia, 110066, 399-416. zavala c. & mutti e. (1996) – stratigraphy of the pliopleistocene sant’arcangelo basin, basilicata, italy. riunione annuale 1996 del gruppo informale di sedimentologica, atti,. 279-282. catania, (italia) 10-14 ottobre 1996. 267 ms. ricevuto il 13 maggio 2003 testo definitivo ricevuto il 18 novembre 2003 ms. received: may 13, 2003 final text received: november 18, 2003 le successioni alluvionali e lacustri quaternarie ... sess 0_retro e indice edi.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 the early to middle pleistocene italian bovidae: biochronology and palaeoecology maria rita palombo 1,2, federico masini 3 & roberto rozzi 1 1 dipartimento di scienze della terra, università “sapienza”, roma, italy 2 cnr, igag, roma, italy 3 dipartimento di geologia e geodesia, università degli studi di palermo, palermo, italy. corresponding author: r. rozzi <roberto.rozzi84@gmail.com> abstract: palombo m.r., masini f. & rozzi r. the early to middle pleistocene italian bovidae: biochronology and palaeoecology. (it issn 0394-3356, 2011) bovids are common elements in the italian local faunal assemblages (lfas), but their diversity and ecological role varied in lfas as well as in faunal units (fus) throughout the early and middle pleistocene. representatives of bovini tribe are continuously present, albeit with different lineages, while “caprini” are sporadically recorded by several genera, and antilopini are the less represented. riassunto: palombo m.r., masini f. & rozzi r. i bovidi italiani del pleistocene inferiore e medio: biocronologia e paleoecologia. (it issn 0394-3356, 2011) durante il quaternario, i bovidi sono elementi comuni delle faune locali (lfas) italiane, ma la loro diversità e i loro ruoli ecologici variano specialmente nel corso del pleistocene inferiore e medio. i bovini sono presenti in tutto l’intervallo di tempo considerato, sebbene con diversi generi e linee evolutive, mentre il record dei “caprini” è discontinuo e gli antilopini sono la tribù meno rappresentata. key words: bovidae, early pleistocene, middle pleistocene, italy parole chiave: bovidae, pleistocene inferiore, pleistocene medio, italia 1. introduction during the quaternary, in italy, as in eurasia, bovids are common elements in local faunal assemblages (lfas), though the richness of the italian bovidae is less than in most european regions. their dispersion and commonness vary over time and across the peninsula due to a multiple set of factors, including discontinuity in the fossil record, ecological and taphonomical biases. a few european genera of different tribes, such as saiga, ammotragus, caprovis, soergelia and ovibos, are missing (palombo, 2009) as well as some species which seem to have been either endemic in the north eastern mediterranean (euthyceros thessalicus, antilope (= parastrepsiceros) koufosi) or present even in the black sea area (pontoceros ambiguus) (kostopoulos, 2006; crégutbonnoure, 2007). conversely, two species either endemic (e.g. hemibos galerianus) or rarely reported in europe (e.g. bubalus murrensis) are recorded in central italy. 2. the fossil record bovini during most of the early pleistocene, the representatives of the tribe are the large, but quite slender leptobos present during the early to late villafranchian with two sub-genera, leptobos (leptobos) and leptobos (smertiobos), whose species provide an important part of the fossil documentation of this genus in europe (masini, 1989; duvernois, 1990; gentili & masini, 2005). the soundest documentation comes from the historical collections from the upper valdarno, montopoli (lower valdarno), olivola (aulla basin), triversa (san paolo and dusino), and from recent excavations in upper valdarno, pietrafitta (tavernelle basin), the chiana valley, and the tiberino basin (see gentili & masini, 2005). leptobos was replaced during the latest villafranchian (pirro fu) by the rather stout bison (eobison) degiulii, while the heavy and even larger bison schoetensacki is recorded in the galerian lfas. at the beginning of the middle pleistocene the large species hemibos galerianus, derived from an indian genus, is only reported from the middle galerian lfas of the roman basin. the auroch, bos primigenius, appeared a bit later in lfas of the isernia fu and became more and more abundant during the late middle and late pleistocene. the late middle pleistocene bovini guild is characterized by the occurrence of the water buffalo bubalus murrensis, and perhaps also by the spread of the steppe bison, bison priscus. antilopini only two representatives of this tribe are reported in the italian fossil record. the larger one, gazella borbonica, the single species of gazella occurring in southern europe since the ruscinian (kostopoulos, 2006), appeared in the italian peninsula at the beginning of the early pleisocene and is recorded in the middle villafranchian, mainly in central italian lfas. the anticlockwise spiral horned gazellospira torticornis, a parkland dweller, 158 160 159 table 1 – integrated chronological scheme for the late pliocene to late pleistocene bovidae of the italian peninsula. schema cronologico integrato e distribuzione del record dei bovidi italiani dal tardo pliocene al pleistocene superiore. the early to middle pleistocene italian bovidae: ... 160 appeared later in the gelasian, but survived most of the early late villafranchian (olivola, tasso fu). “caprini” a representative of the enlarged caprini sensu lato tribe (see ropiquet & hassanin, 2005; bibi et al., 2009 for a discussion), hemitragus cf. h. orientalis, is first dubiously reported at the beginning of the early pleistocene in the collepardo lfa (montopoli fu) but the specimens have never been described. during the following middle villafranchian, the goral gallogoral meneghinii appeared, while procamptoceras brivatense, phenetically close to the living rupicapra (masini & lovari, 1988), occurred later. the occurrence of the ancient muskox praeovibos sp. (lately referred to as preaeovibos cf. p. mediterraneus by crégut-bonnoure, 2005; 2007) is reported from the tasso fu by de giuli & masini (1983). the remains of a large “caprini” found in the pirro lfa (de giuli et al., 1986) have recently been assigned by crégut & dimitrijević (2006) to megalovis balcanicus. during the early middle pleistocene, the fossil record of “caprini” consists of only scanty remains. a few teeth of hemitragus bonali were found at isernia la pineta (sala, 1996), while ovis ammon antiqua was present during the late galerian, not only in the northeastern corner of the italian peninsula (visogliano shelter, abbazzi et al., 2000), but also in central italy, likely in the pg4 deposits of the ponte galeria/magliana area (cfr. rozzi et al. in press). chamoios (rupicapra) and ibex (capra ibex) possibly were already spread during the latest middle pleistocene across the italian peninsula as documented by the paglicci lfa (cfr. palombo, 2009 and references therein). 3. remarks throughout the early and middle pleistocene, the diversity and ecological role of italian bovids were changing in lfas as well as in faunal units (fus). during the gelasian and the early calabrian (from montopoli to tasso fu), species of the genus leptobos, sometimes found in association with small bovids mainly antilopini and caprini, were definitely the most frequent (gentili & masini, 2005) (tab. 1). this time span shows the highest bovid diversity peaking at the time of the olivola fu. almost all ecological categories are represented, though the percentage of large bovids increases throughout the early late villafranchian. during the following early pleistocene (farneta, pirro and collecurti fus), diversity dramatically decreased. a number of middle and early late villafranchian taxa disappeared, while representatives of the genus bison replaced leptobos, and among middle sized bovids, only megalovis is thus far recorded in the pirro nord lfa (tab. 1). during the middle pleistocene, the diversity of bovids progressively increased due to the appearance of both large and very large bovini (hemibos galerianus, bos primigenius and then bubalus murrensis) and caprini, as well. among the latter, hemitragus bonali and ovis ammon antiqua are reported from a few early middle pleistocene sites, whereas capra ibex and rupicapra, which appeared at the end of the middle pleistocene, are very frequent throughout the late pleistocene. references abbazzi l., fanfani f., ferretti m. p., rook l., cattani l., masini f., mallegni f., negrino f., tozzi c. (2000) new human remains of archaic homo sapiens and lower palaeolithic industries from visogliano (duino aurisina, trieste, italy) – journal of archaeological science, 27, 1173-1186. bibi f., bukhsianidze m., gentry a. w., geraads d., kostopoulos d. s. & vrba e. s. (2009) the fossil record and evolution of bovidae : state of the field. palaeontologia electronica, http://palaeo-electronica.org. crégut-bonnoure e. (2005) nouvelles données paléogéographiques et chronologiques sur les caprinae (mammalia, bovidae) du plio-pléistocène moyen et supérieur d’europe homenaje a jesús altuna, munibe (antropologia-arkeologia), san sebastian, 57, 205-219. crégut-bonnoure e. (2007) apport des caprinae et antilopinae (mammalia, bovidae) à la biostratigraphie du pliocène terminal et du pléistocène d’europe – quaternaire, 18, 73-97. crégut-bonnoure e. & dimitrijević v. (2006) megalovis balcanicus sp. nov. and soergelia intermedia sp. nov. (mammalia, bovidae, caprinae), new ovibovini from the early pleistocene of europe. revue de paleobiologie, 25, 423-473. de giuli c., masini f. (1983) a new element of the late villafranchian (tasso unit) faunas of italy: occurrence of ovibovini (bovidae, arctiodactyla, mammalia) in the fauna of casa frata (upper valdarno, tuscany). bollettino società paleontologica italiana, 22, 271-280. de giuli c., masini f. & torre d. (1986) the latest villafranchian faunas in italy: the pirro nord fauna (apricena, gargano). palaeontografia italica, 74, 56-62. duvernois m.p. (1990) les leptobos (mammalia, artiodactyla) du villafranchien d’europe occidentale. systématique, évolution, biostratigraphie, paléoécologie. documents des laboratoires de géologie de la faculté des sciences de lyon, 113, 1-213. gentili s. & masini f. (2005) an outline of italian leptobos and a first sight on leptobos aff. vallisarni from pietrafitta (early pleistocene, perugia) – quaternaire hors-série, 2, 81-89. kostopoulos d. (2006) greek bovids through time. hellenic journal of geosciences, 41, 141-152. masini f. (1989) i bovini villafranchiani dell'italia. phd dissertation, university of modena and florence. masini f. & lovari, s. (1988) systematics, phylogenetic relationships, and dispersal of the chamois (rupicapra sp.). quaternary research, 30, 339–349. palombo m.r. (2009) biochronology of terrestrial mammals and quaternary subdivisions: a case study of large mammals from the italian peninsula. il quaternario, 22, 291-306. ropiquet a. & hassanin a. (2005). molecular phylogeny of caprines (bovidae, antilopinae): the question of their origin and diversification during the miocene. journal of zoological systematics, 43, 49-60. rozzi r., palombo m.r., barbieri m. in press the argali (ovis ammon antiqua) from the magliana area (rome). il quaternario, in press. sala b. (1996). gli animali del giacimento di isernia la pineta. in: peretto (eds.) – i reperti paleontologici del giacimento paleolitico di isernia la pineta, isernia, 25-49. m.r. palombo, f. masini & r. rozzi sess 4_17022011.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 palaeoenvironment reconstruction using pollen and plant macrofossils: the archaeological site of via neroniana (montegrotto terme – padova) michele maritan1, barbara gaudioso2 & antonella miola2 1dipartimento di geografia, università degli studi di padova 2dipartimento di biologia, università degli studi di padova corresponding author: m. maritan <michele.maritan@unipd.it> abstract: maritan m., gaudioso b. & miola a., palaeoenvironment reconstruction using pollen and plant macrofossils: the archaeological site of via neroniana (montegrotto terme padova). (it issn 0394-3356, 2011) this presentations shows the results of a palaeobotanical research in an archaeological site occupied from the copper age to the medieval time in the thermal area of euganean hills. the results of pollen and plant macrofossils‘ analysis help in the reconstruction of the palaeoenvironment evolution back to the last glacial maximum, with new insight on the thermal water influence on the site and the human presence before the construction of a roman villa. riassunto: maritan m., gaudioso b. & miola a., ricostruzione paleoambientale tramite polline e macroresti vegetali: il sito archeologico di via neroniana (montegrotto terme – padova) (it issn 0394-3356, 2011) questa comunicazione presenta i risultati delle ricerche paleobotaniche in un sito archeologico frequentato dall’età del rame fino al medioevo nell’area termale dei colli euganei. i risultati dall’analisi del polline e dei macroresti vegetali aiutano a ricostruire l’evoluzione del paleo ambiente fin dall’ultimo massimo glaciale, con nuovi sviluppi sull’influenza dell’acqua termale sul sito e la presenza umana precedente alla costruzione di una villa romana key words: palaeoenvironment, montegrotto terme, euganean hills, pollen, plant macrofossils parole chiave: paleo ambiente, montegrottoterme, colli euganei, polline, macroresti vegetali archaeobotanical analyses are widely applied to the reconstruction of past landscapes. recently, the demand for a more detailed information on climate and environmental history, including the impact of man on natural landscapes, has stimulated a multi-proxy approach to the study of palaeoenvironments (birks & birks, 2006). this approach has been adopted in the archaeological site of “via neroniana” at montegrotto terme (padova) in the euganean thermal area. the area is well known since protohistory and exploited in roman times for leisure and healing. since the copper age the human presence in the site is well documented. particularly important are the archaeological findings of a monumental roman villa (i sec. a.d.) and a of a medieval settlement (ix-xi sec. a.d.)(fig. 1). huge effort in ground lifting and draining of the site is documented in both occupations (zanovello & basso, 2007; 2008). the almost continuous human presence suggests that the environmental features should be determinant in the reoccupation of the site. the reconstruction of the palaeoenvironment in a thermal area was approached by means of geomorphological, sedimentological, palaeo-botanical, stratigraphic, soil micromorphological and radiocarbon dating methods. sediments were collected in several drillings and archaeological open sections. pollen, plant macro remains and a variety of algal, fungal and zoological micro remains have been investigated. biological indicators were selected in the fossil records. the cores’ lithology has been studied and used for stratigraphic correlations. the results integrate archaeology in providing a comprehensive framework of human-environment interactions. this presentation shows palaeobotanical results (pollen, macrofossils) from 8 cores, 4 to 10 meters deep, and an open section (section p in fig. 1). on the basis of biological data the natural and cultural landscape can be reconstructed in the following periods: i) the last glacial maximum. the area was waterlogged; pollen and other palynomorphs (npps) in a sequence of clay, sand and silt sediments document that a steppe environment was around the basin. the finding of fossil seeds of the alophilous specie juncus gerardi is quite important to reconstruct the palaeoenvironment as the thermal water of montegrotto is characterized by salinity comparable to marine water (panichi et al, 1976). j. gerardi was abundant around the thermal springs before the urbanization of the euganean thermal area in 1904, as reported by beguinot (1904). moreover the presence of fossil thermal diatoms and gastropods indicate that thermal waters fed the shallow basin. a well dated layer of clay defines the geomorphological profile of the basin at the age of about 19,000-18.000 cal yrs bp. ii) the beginning of the late glacial. pollen and macro remains in lacustrine sediments record the 189 191 190 onset of the climatic improvement (rare but constant presence of thermophilous and mesophilous plants and the expansion of pioneering elements as pinus). the findings of j. gerardi seeds and an exceptionally high percentage of chenopodiaceae pollen suggest that thermal water still fed the basin and a saline soil developed around. almost twice the clay sedimentation has been interrupted by alluvial sedimentation in the south eastern part of the area. differently the north western part was continuously waterlogged and a thicker layer of clay than in the central part of the area was deposited. very high sedimentation rates produced minerogenic deposits entirely devoid of recognisable plant remains. at the top a soil developed in the entire area (p. mozzi and c. nicosia pers. comm.). iii) the beginning of the holocene. in the north western part of the archaeological area a new fig. 1, map of the archaeological area of via neroniana with localization of the cores and section p (maritan m., 2010, modified) mappa dell’area archeologica di via neroniana, con localizzazione dei carotaggi e della sezione p (maritan m., 2010, modificata)  m. maritan, b. gaudioso & a. miola 191 ms. received: testo ricevuto il brief phase of lacustrine sedimentation preserved pollen associations with increasing quercus, they can be compared with the pollen associations at the base of the lake of fimon holocene sequence (valsecchi et al., 2008). the upper part of the pollen sequence is disturbed by human activities. iii) the late holocene before the construction of the villa. a sedimentary sequence of a shallow water body is well preserved in an open archaeological section under the foundations of the villa (section p in fig. 1). the clay layer at the bottom of the sequence preserved pollen of rye, vitis and of many anthropogenic indicators. the increasing picea and abies and decreasing thermophilous elements suggest a period of less warm and more humid climate respect to the holocene sequence already described. it could be correlated with the top of holocene (iron age?) by comparison with other pollen sequences in the region (valsecchi et al., 2008). the curves of several aquatic and hydrophilous plants, as juncus gerardi, typha latifolia/ angustifolia, ranunculus subgen. batrachium, chara vulgaris and nitella tenuissima suggest progressive dryer conditions and the filling up of the water body. pollen of secale, verbena officinalis and poa palustris/p. pratensis seeds points to cultivation. thermal springs still fed the water body as it is suggested by the presence of juncus gerardi seeds. in a quite close (3 m apart) core, m01, stratigraphically correlated to the sequence of section p, several pips of vitis vinifera subsp. vinifera, with seeds of euphorbia helioscopia, (a common weed of grapevine cultivations) have been found. the seeds have been recorded in late glacial sediments and have been interpreted as evidenceof a grapevine cultivation over the old late glacial soil before the construction of the villa. v) the roman age. the sediments dated by archaeological findings and analyzed so far did not preserve any plant remains. the hydrological conditions of the area and the attractive thermal springs lead to the building of the villa, through reclamation of part of the swampy lake shore by means of 1-2 m thick landfills. vi) the medieval occupation. a new settlement (ixxii cent. a.d.) occupies the site of the villa. land reclamation works were done in the area before the occupation. a variety of archaeobotanical findings hint at diversified agricultural and mostly food processing activities, as cereal and legumes cultivation and processing (hordeum vulgare, triticum aestivum/t. durum, panicum miliaceum, setaria italica, lens culinaris ), grapevine cultivation and wine making (vitis vinifera subsp. vinifera), textile and possibly dying activities (linum usitatissimum, reseda luteola, sambucus ebolus). the most relevant archaeobotanical results are: i) the continuous presence of thermal water springs in the area, since the lgm period. this environmental peculiarity should explain the reoccupation of the site till the modern time; ii) the finding of secale that has been rarely found in northern italy before the roman age (mercuri et al, 2006). this is the first record of cultivation of rye in the euganean area; iii) the new record of an agricultural phase with cereal and grapevine cultivation before the roman occupation (imperial age villa). funds were supplied by the dept. of archaeology (university of padova) in 2006-2008, murst (ex 60% a. miola 2005-2010) and by the project picar prin 2008fjcef4. (scient. coord. a. m. mercuri). references birks h. h. & birks h. j. b. (2006) multi-proxy studies in palaeolimnology. veget. hist. archaeobot., 15, 235251. beguinot a. (1904) saggio sulla flora e sulla fitogeografia dei colli euganei. memorie della società geografica italiana, 11, roma. maritan m. (2010) primi risultati dell’analisi di macroresti in sedimenti naturali e antropici nello scavo di via neroniana a montegrotto terme (pd)(campagne di scavo 2007-2008). quaderni del dottorato, 4, 127-138, dipartimento di geografia, università degli studi di padova. mercuri a. m., accorsi c. a., bandini mazzanti m., bosi g., cardanelli a., labate d., marchesini m. & trevisan grandi g. (2006) economy and environment of bronze age settlements – terramaras – on the po plain (northern italy): first results from the archaeobotanical research at the terramara di montale. veget. hist. archaeobot., 16, 43-60. panichi c., tongiorgi e., baldi p., ferrara g. c., ghezzi g. & marchetti m. (1976) geochimica delle acque termali euganeoberiche, in piccoli g.(ed.) il sistema idrotermale euganeo-berico e la geologia dei colli euganei, società cooperativa tipografica, padova, 113-130. valsecchi v., fisinger w., tinner w. & ammann b. (2008) testing the influence of climate, human impact and fire on the holocene population expansion of fagus sylvatica in the southern prealps (italy). –the holocene, 18, 603-614. zanovello p. & basso p. (2007) montegrotto terme via neroniana. indagine archeologica 2006. quaderni di archeologia del veneto, 23, 19-28, regione del veneto, canova zanovello p. & basso p. (2008) montegrotto terme via neroniana. indagine archeologica 2007. quaderni di archeologia del veneto, 24, 23-24, regione del veneto, canova. january 15, 2011 15 gennaio 2011 palaeoenvironment reconstruction using pollen and plant ... available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 37 (1), 2024, 67-82 ocene sapropel s1 has been widely identified in the eastern mediterranean. its formation is primarily due to the increased fluvial discharge from the nile river and the central saharan watershed (rossignol-strick et al., 1982; gallego-torres et al., 2010; williams et al. 2015; blanchet et al., 2021), linked to enhanced monsoonal activity over equatorial africa, with a partial contribution of increased precipitation in the mediterranean region including its northern borderlands (rohling & hilgen, 1991; kotthoff et al., 2008; geraga et al., 2010; toucanne et al., 2015; wu et al., 2017). in the east mediterranean, s1 broadly spans from 10.8 cal ka bp to 5.5 cal ka bp, separated in two distinct phases (s1a and s1b) with a short interruption roughly centered at 8 cal ka bp (kotthoff et al., 2008; geraga et al., 2010; hennekam et al., 2014; triantaphyllou et al., 2014; grimm et al., 2015; filippidi et al., 2016; wu et al., 2017; di donato et al., 2019; wu et al., 2019). west mediterranean orls could be considered as weakly expressed sapropels (rogerson et al., 2008), corresponding to anoxic phases, linked to water stagnation and enhanced biological production that depletes the available oxygen (grimm et al., 2015). these anoxic phases may have been originated by hydrological and productivity changes related to the atlantic inflow from the gibraltar strait that could have induced the reduction https://doi.org/10.26382/amq.2024.04 1. introduction the mediterranean region is particularly influenced by climatic variations due to its semi-enclosed basin, being influenced by the north african subtropical climate and the temperate european westerly atmospheric circulation (e.g. lionello et al., 2006). one of the most important type of paleoclimatic events found in this area is the deposition of reducing layers, mainly identified as sapropels in the east mediterranean and as organic rich layers (orls) in the west (rossignol-strick, 1985; rohling, 1994; rogerson et al., 2008; negri et al., 2012; fink et al., 2013; rohling et al., 2015; incarbona & sprovieri, 2020; pérez asensio et al., 2020). sapropels are organic-rich layers recovered in marine sediments from many localities throughout the eastern and central mediterranean basin. kidd et al. (1978) described them as sharply defined, dark colored sedimentary layers with a c org content > 2 wt.% and thickness >1 cm. orl are defined as dark sediment layers with total organic carbon (toc) content up to 1 wt.% (rogerson et al., 2008; negri et al., 2012; fink et al., 2013). sapropelic layers occur almost periodically in the sediments of the last 13.5 million years in the mediterranean sea, more often developed in the eastern than in the western sub-basins (rohling et al., 2015). the holevidence of anoxic layers in the central tyrrhenian sea between 29 and 4.2 ka valerio ruscito 1 , luisa conforto 2 , luigia manfra 2 , maria preite martinez 2 1 applied geophysics unit geo-gfi, geological survey of italy, ispra, rome, italy. 2 department of earth sciences, sapienza university of rome, rome, italy. corresponding author: valerio ruscito <valerio.ruscito@isprambiente.it> abstract: heavy metals contents are analyzed in a continuous sediment record spanning from 29 to 4.2 ka bp, sampled on the upper continental slope facing the ombrone river mouth (tyrrhenian sea) and investigated in previous works by isotopic and micropaleontological studies supported by radiocarbon dates. the aim of this work is to use changes in some heavy metals contents, which were shown to reflect change in the ph and eh on the sea floor environment, to investigate the mechanism involved in the expression of bottom anoxia between 29 and 4.2 in the central tyrrhenian sea. fe, mn, and pb content shows significant correlations with paleoenvironmental changes. pb elemental concentration proved to be the most powerful tool to reconstruct environmental redox conditions, being greatly enhanced during strong anoxia phases and showing conservative behavior not influenced by post depositional diagenesis. geochemical evidence from ombrone submerged delta sediment suggest the occurrence of two reducing phases. during the holocene, data highlight the presence of a reducing layer in the west mediterranean between 7.4 and 5.7 ka bp, with a climax between 6.8 and 5.7 ka bp, in agreement with previous evidence. in this period, probably, enhanced river runoff increased the flux of continental organic matter into the basin and reduced sea surface salinity, leading to the formation of an anoxic environment. the presence of this reducing layer agrees with evidence of a “pluvial” period recognized by other authors in the west-central mediterranean, partially synchronous with the sapropel s1 formation in the east, suggesting its regional character and its extension to the whole mediterranean basin. additionally, trace metal data suggest the occurrence of an additional anoxic phase, not previously recognized, and occurring during the last glacial period, at about 27.2 ka bp. keywords: reducing layers; heavy metals; west mediterranean sea; last glacial-middle holocene period; paleoclimatology; inorganic geochemistry. mailto:valerio.ruscito@isprambiente.it of the deep circulation (rohling et al., 2015). they also could derive from an enhanced river runoff, following the deglaciation and the alpine ice melting, or from an increasing precipitation regime that caused a decrease in surface salinity (rogerson et al., 2008; rohling et al., 2015; grant et al., 2016; bakrač et al., 2018; bazzicalupo et al., 2018; pasquier et al., 2019). the great influence of the north atlantic climate on western mediterranean hydrological activity is demonstrated by many other authors (bard et al., 2002; zanchetta et al., 2007; toucanne et al., 2015; pasquier et al., 2019; wagner et al, 2019). late glacial-holocene anoxia periods, leading to orl deposition, are found in the alboran sea, spanning from 15 to 8.5 ka bp (rogerson et al., 2008; fink et al., 2013; jimenez-espejo et al., 2015; dubois-dauphin et al., 2017; bazzicalupo et al., 2018), in the gulf of lion (pasquier et al., 2019) and in the ligurian sea spanning from 15 to 11 ka bp and from 11 to 6 ka bp (le houedec et al., 2021). all these studies prove an important enhance of freshwater runoff from northern borderland in the west mediterranean basin. at present the runoff in this region mainly depends on the north atlantic atmospheric circulation and is affected by local orography of the coasts (trigo et al., 2002; kandiano et al., 2014). the present work focuses on climatic changes recorded in several cores collected in the arcipelago toscano basin, in the central tyrrhenian sea, near the ombrone river mouth (fig. 1). one of the core was previously investigated by oxygen isotope analyses on foraminifera and micropaleonotological analyses, together with radiocarbon age determinations (belluomini et al., 2002; carboni et al., 2005). the aim of this work is to use changes in some heavy metal contentsome heavy metalselago toscano b, which were shown to reflect change in the ph and eh on the sea floor environment, to investigate the mechanism involved in the expression of bottom anoxia between 29 and 4.2 in the central tyrrhenian sea (fig. 1). (thomson et al., 1995; warning & brumsack, 2000; naimo et al., 2005; reitz et al., 2006; tribovillard et al., 2006; angelidis et al., 2011; heimbürger et al., 2012; oliveri et al., 2013; jiménez-espejo et al., 2015; martinez-ruiz et al., 2015). this approach is suggested by previous works (conforto & manfra, 2004; conforto & manfra, 2007; conforto et al., 2008), that evidenced significant correlations between heavy metals behaviors and paleoclimatic changes. new geochemical analyses, reported in this work, together with a review of previous geochronological, isotopic, sedimentologic and micropaleontological results, allowed a more detailed paleoenvironmental reconstruction of this area. 2. study area and material the studied area (fig. 1) is comprised between the 200 m isobath and the tuscany coast, in the arcipelago toscano national park area. it is limited on the south by the argentario mount and giglio island, extending northward to punta ala and elba island in the tuscan mining district (elba island and metalliferous hills on the mainland). the continental shelf receives terrestrial sediment supply mainly discharged from the ombrone river (monthly min/max mean discharge 4/50 m3/s) (bellotti et al., 2004). the role of the minor rivers (bruna and albenga) is subordinate. the ombrone river is 161 km long and drains a basin of 3496 km2 characterized by phyllites, quartzites, arenites, siliceous and carbonate sequence, plio-pleistocene clayey-sandy sediments, ophiolitic sequences and trachyandesite volcanics (bellotti et al., 2004). at present, the ombrone mouth is a wavedominated delta consisting of fine sand to clay sediments (tortora et al., 1999; bergamin et al. 2001). coarser fluvial sediments are distributed mainly northward by longshore currents, while finer ones drape the shelf (aiello et al., 1975; tortora, 1999). this area was shown to be ideal for quaternary paleoclimatology studies based on geological and geochemical analyses (belluomini et al., 2002; carboni et al., 2005), due to its geomorphological condition of a semi-enclosed basin. a submerged structural high, called elba ridge, delimits the shelf to the western side and has a great impact on the morphologic and sedimentary setting of the area, both presently and during the late quaternary sea-level lowstand (roveri & correggiari, 2004). geochemical analyses were performed on the z145 core, located on the upper continental slope at about 22 km sw off the ombrone river mouth, at a depth of 150.8 m (fig. 1). during the last glacial maximum (lgm), the continental shelf was largely exposed, and the distance between the z145 sampling site and the ombrone mouth was only about 7 km (alessio et al., 1994). during the last deglaciation, the sea level rise and the following stabilization (3.5-3.0 ka bp) caused the eastward migration of the ombrone river mouth, and a lagoonal delta system developed (carboni et al., 2005). z145 core is about 4 m long and spans continuous 68 ruscito v. et al fig. 1 map of the study area and samples locations. black dot indicates the core z145 (150 m depth, lat. 42°32’15” n, long. 10°47’47” e), sampled on the upper continental slope about 22 km sw off the present-day ombrone river mouth. open triangles show the eight box-cores sampled on recent sediments of the continental shelf. 69 evidence of anoxic layers in the central tyrrhenian sea between 29 and 4.2 ka. fig. 2 a) lithological log of core z145 and samples analyzed in this study (● ). b) sedimentation rate (sr) is calculated using measured radiocarbon dates. modified from carboni et al. (2005). ly from about 29 to 4.2 cal ka bp. to know the present heavy metals background in the area, analyses were also carried on recent sediments sampled in 8 boxcores (a4, a5, a7, b60, b6m, f12, i12 and a15f), collected on the continental shelf (fig. 1). core b60 is the site nearest to z145 and represents a good candidate to study the recent sediments at the top of the z145, that were lost during sampling. the z145 sediment consists mainly of grey mud in the upper part of the core, and of an alternation of muddy and sandy mud levels below 180 cm. the detailed log and sedimentological features of z145 core are reported in carboni et al. (2005), together with isotopic (δ18o on foraminifera) and micropaleontological results. the record is anchored to an age model supported by seven radiocarbon dates (carboni et al., 2005). the sedimentation rate (sr) in z145 is very low during the glacial period, sharply increases in the younger dryas and reaches the highest value at about 7.5 cal ka bp, when anoxia conditions established (fig. 2). the eight small cores of recent sediments are about 15 cm long (a4, a5, a7, b60, b6m, f12, i12, a15f) and are mainly composed of silty clay. they are dated between 1950 and 1992 by 137cs and 210pb methods (belluomini et al., 2002). 3. previous paleoclimatic evidences the previous analyses carried on z145 core allow the paleoclimatic reconstruction for this area. basing on micropaleontological and isotopic evidence, carboni et al. (2005) identify the glacial period in the bottom layers, and the lgm at about 26 cal ka bp (tab. 1 and fig. 3, dates recalibrated in this work), according to ivy-ochs et al. (2008), mccullock et al. (2010), shakun et al. (2010), adamson et al. (2013), domnguez-villar et al. (2013), sarikaya et al. (2015), oliva et al. (2018) and seguinot et al. (2018). z145 proxies identify also the younger dryas cold event, spanning from about 12.9 cal ka bp to 11.7 cal ka bp, according to several authors (ivy-ochs et al., 2008; mccullock et al., 2010; fiedel, 2011; carlson, 2013; fink et al., 2013; kennet et al., 2015; beyin et al., 2017; bazzicalupo et al., 2018; gromig et al., 2018; keigwin et al., 2018; oliva et al., 2018; pauly et al., 2018; ribolini e al., 2018). a cooler period is highlighted between 8.8 and 7.4 cal ka bp, synchronous with the cooling event recorded at 8.2 cal ka bp, according to several authors (rohling & pälike, 2005; spötl et al., 2010; magny et al., 2011; rodrigo-gàmiz et al., 2011; lirer et al., 2013; schemmel et al., 2016). a warm and wet period with stratified oligotrophic waters occurred from 7.4 cal ka bp until about 5.2 cal ka bp. micropaleontological data suggest anoxic condition, likely related to a hard rainy phase, spanning about 1000 years, established on the borderland of western mediterranean basin, as recognized in croatia (bakrač et al., 2018) and in sw spain (schröder et al., 2018). after the anoxic event, bottom water oxygenation reestablished, and climatic conditions changed in a drier and cooler period corresponding to the top of the core and placed at about 4.2 cal ka bp, in agreement with 70 tab. 1 z145 radiocarbon dates (from carboni et al., 2005, modified using reimer et al., 2020 calibration curves). a = ams dates; b = lsc dates; m.p. = median probability. dated control points are shown in bold and dates in italics are extrapolated and approximated to 10 years. in the first column, asterisks (*) indicate the chemically analyzed levels. geochemical data: δ18o of g. bulloides (from carboni et al., 2005). ruscito v. et al 5. results and data interpretation table 1 report δ18o data and radiocarbon ages determination for core z145, presented in carboni et al. (2005). tables 2-6 show concentrations values of fe, mn and pb of the analyzed samples from z145 core, used for the paleoclimatic reconstruction, and from the 8 box-cores (fig. 1), which provide information about the recent background of these elements in the area. great significance has the box-core b60 because it is the site nearest to z145 and represents a good candidate to study the top sediments lost during z145 sampling. our data allow a detailed study of geochemical behavior of pb, mn and fe in order to obtain a better reconstruction of paleoenvironmental conditions in the ombrone delta submerged area. concerning the general behavior of elements in various ph and eh conditions see glasby (2006), mihaljevic (1999), williamson (1999). overall, variations in pb, mn and fe content studied in the z145 record are in good agreement with the previously identified climatic phases (see sec.3) from the last glacial period until 4.2 cal ka bp, allowing often a better delimitation of their boundaries (fig. 3). 5.1. pb in core z145, pb shows highly enhanced values both in the glacial and the holocene periods. during the holocene, the distribution of pb (tab. 2a and fig. 3a) shows a concentration increase between 6.8 and 5.7 cal ka bp, with a peak zone mean of 246 ppm, reaching its maximum at 6.2 cal ka bp (332 ppm). these values are clearly anomalous: the peak value is about 13 times higher than the mean (26 ppm) of the other values during the holocene. moreover, these values are about six times the b60 mean (56 ppm, tab. 3), and about nine times the present background in the area (35 ppm, tab. 4). in these levels, the sedimentation rate (sr) (fig. 2) increases to 44 cm/ka, while at the beginning of the holocene it was about 22 cm/ka (see fig. 3a). overall, there is not a strict correlation between pb variation and several authors (melki et al., 2009; colonese et al., 2013; lirer et al., 2013; di rita et al., 2018; schröder et al., 2018; bini et al., 2019; isola et al., 2019). during the mid-holocene period, magny et al. (2011), colonese et al. (2013) and di rita et al. (2018) identify a paleoclimatic limit, between the se/nw mediterranean regions, placed at 40-42° n, characterized by wetter winters in the northern areas and humid summers in the southern. as the z145 core is situated at 42° 35’n, the study area is likely mainly representative of the climatic situation of the northern mediterranean region, perhaps with some influences from the southern. 4. materials and methods analyses of fe, mn and pb concentrations were performed on 17 sediment samples from core z145 and on 8 samples from the box-cores, using an icp-aes housed in the earth science department of the sapienza university (rome). instrumental errors mainly range between 1-15%. total concentrations were determined following a strong hot acidic attack using mixtures of perchloric and hydrofluoric acids. a sequential extraction to measure metals partitioning into the main fractions was performed following the method proposed by sahuquillo et al. (1999). in order to improve the knowledge of the elements behaviors in different environmental conditions, we directly measured concentrations in the carbonate, oxides and organic partial fractions, while the residual content has been determined as difference. not all oxides, mostly the fe oxides, could be dissolved in this sequential analysis (fletcher, 1981), the metals easily removable (i.e. adsorbed on the clay minerals) are comprised in the carbonate fraction. radiocarbon dates of core z145 (from carboni et al., 2005) are recalibrated using the marine calibration curve intcal20 (reimer et al., 2020) and expressed as calendar marine ages with a reservoir age correction of 400 yrs. isotopic values are reported following new ages calibration. (tab. 1). for the micropaleontologic data see carboni (2005). 71 fig. 3 heavy metals concentration in core z145. a) pb concentration curve. b) fe/100 and mn concentration curves, their data are reported using different scales. c) g. bulloides δ18o values from carboni et al (2005). points mark the analyzed samples (see tab. 1). the grey areas show the younger dryas and reducing climax periods, the grey line indicates the last glacial maximum (lgm). pb and fe recent background are reported. mn mean value is calculated from glacial and holocene z145 means. evidence of anoxic layers in the central tyrrhenian sea between 29 and 4.2 ka. sr trend throughout the entire record, indicating that probably pb anomalies are not primarily driven by increases in inland sedimentary contribution. the high pb values probably are due to environmental conditions with low redox potential (eh), where the bacterial activity reduces the sulfates to sulfides, leading to the precipitation of pb as pbs (zhang et al., 2014; turner et al., 1986). pbs is not influenced by post depositional reoxi 72 dation, as its solubility product is the lowest, after hgs, among metallic elements sulfides. the reducing conditions are probably due to an enhanced freshwater input that, together with following reduced sea surface salinity highlighted by the isotope data, hampered the bottom water levels oxygenation. this is in good agreement with drab (2015), who found heavy metals sulfides increase in two sapropels in the marmara sea. tab. 2 heavy metals concentrations in core z145. a) holocene samples. top record does not coincide with the seafloor as the top sediments were lost during sampling. b) glacial samples. ages are calculated from control points (tab. 1). tab. 3 pb, fe/100, mn concentrations in b60 box-core. tab. 4 pb, fe, mn mean values in recent samples (box-cores). the last column shows the present background of the area, calculated from all of the sites means. tab. 5 pb, mn, fe percentage distributions in the partial fractions in core z145 and in box-core b60. in z154, level at 108 cm corresponds to the reducing layer, level at 215 cm corresponds to the beginning of the holocene. ruscito v. et al carbonate. at the -108 cm level its values reach about 90% in the residual phase, being only 10% in the organic one, and close to zero in the two other phases. these values support the notion of an anoxic environment, causing a remarkable pb precipitation as pbs. during chemical sequential extraction, pbs is dissolved after the oxidizing step, with following precipitation as pbso4 enriched in the residual phase (cappuyns et al., 2007). this evidence confirms the attribution of the level at 108 cm to an anoxic period, when reducing conditions were strong enough to hamper the presence of pb in the oxide and carbonate phases. in the older level at 215 cm, pb shows higher values in the organic and oxide phases, suggesting a presence of a more oxidized environment. in b60 (tab. 5, fig. 4c), pb concentrates mainly in the organic and residual fractions and this distribution differs from the z145 samples. this is probably due to the diagenesis of the organic matter in the older z145 sediments. pb partition in the oxide and carbonate fractions shows not very significant differences between the two cores, considering that absolute values are about only a few ppm. all data suggest that pb is a very sensitive proxy to another high pb concentration value is also measured during the late glacial, at about 27.2 cal ka bp (tab. 2b and fig. 3a). here, pb reaches 309 ppm, a value close to higher holocene contents and about 13 times higher than the mean of other glacial values (24 ppm). environmental conditions in the study area were very different between the two periods. during the glacial, the ombrone river flowed into the tyrrhenian sea several kilometers closer to the z145 site, increasing the supply from the coastal environment, although the hydrological cycle and the river runoff could have been weaker than during holocene times. although only one sample is here available, because of the low sedimentation rate, as pb value is very similar to the holocene ones, we can hypothesize also in this glacial interval the presence of a reducing layer. the pb behavior in the partial fractions from cores z145 and b60 is also investigated (tab. 5). in z145, values are measured at-108 cm, corresponding to the reducing layer, and at -215 cm, corresponding to the beginning of the holocene (fig. 4d). pb mainly concentrates in the residual (88% at 108 cm and 57% at -215 cm) and organic (10 at 108 cm and 34% at -215 cm) fractions and to a lesser extent in the oxides and in the 73 fig. 4 pb and mn percentage distribution in partial fractions: a) mn in b60; b) mn in z145; c) pb in b60; d) pb in z145. evidence of anoxic layers in the central tyrrhenian sea between 29 and 4.2 ka. identify environmental sapropel-type conditions, highlighted by pb concentrations reaching high anomalous values. it must be emphasized that pb content in these layers is about 9 times the present background, even though this area in the last century has been affected by anthropic pollution, mainly from mining activities and lead-added fuel. evidence confirms that the anomalous concentrations in z145 were exceptionally high compared to present background values, suggesting that holocene, and probably glacial, reducing layers conditions were strongly different than the present. 5.2. mn during the holocene, in the z145 core mn concentration has a mean value of 852 ppm and increases toward the top of the core (tab. 2a, fig. 3b). this feature is due to a remobilization of mn in the deeper, more reducing, levels and its upward diffusion and reoxidation (petrie, 1999). during sedimentation indeed mn is stripped from the sediments and moves to the surficial layers (callender, 2003; glasby, 2006). in reducing conditions, mn oxyhydroxide precipitation is inhibited (the lowest mn value, during this phase is measured at 6.6 cal ka bp) enhancing the concentration of mn+2 dissolved in pore water. above reducing levels, higher mn precipitation occurs during more oxidizing environmental conditions. the subsequent bioturbation of the superficial sediments brought downwards o2 rich waters that oxidized dissolved mn, causing to the formation of a secondary mn peak at 6.2 cal ka bp, still within the anoxic layer previously identified (thomson, 1995; reitz et al., 2006; rey et al., 2008; angelidis et al., 2011; martinez-ruiz et al., 2015). during the glacial period (tab. 2b, fig. 3b), despite the lower sedimentation rate which causes a scarcer resolution in the sedimentary record, there is evidence of some mn variations mostly due to glacial climatic fluctuations (svensson et al., 2008; guilizzoni et al., 2014; oliva et al., 2018) that influenced the environmental and geochemical parameters (depth, distance from coast, temperature, organic substance, river supplies, ph, eh, etc.). tab. 2b and fig. 3b show two glacial mn maximum values (28.2; 22.4 cal ka bp), separated by a minimum at 26 cal ka bp, synchronous with the lgm. mn behaves similarly during the holocene reducing phase, but its re-oxidation begins slightly after the end of the anoxic period identified by high pb values. this delay is probably due to the location of the site nearer to the coast during the glacial period, where the lower ph values hampered the mn precipitation until the environment became oxidizing enough (glasby, 2006). moreover, as “true” marine geochemical conditions (eh, ph, etc.) were not fully attained throughout the glacial period, there is not an increasing trend upwards, as showed by the glacial mn mean which is only 558 ppm, much lower than in the holocene (852 ppm). in recent sediments of core b60 (tab. 3), mn reaches very high values in the top levels due to its remobilization from deeper levels and its upward diffusion and re-oxidation. during the holocene, mn behaviors in b60 and in z145 are similar, but in b60 the oxidation process is stronger because the sampled levels are found in the more oxygenated surficial layers at the water-sediment interface, whereas the top levels of core z145 were lost during sampling. mn geochemical behavior is also evidenced by comparing its mean concentration in b60 to the mn means at other sites of recent deposition (see tab. 4). mn means can be roughly grouped into three different areas (fig. 5). in the first area (b60 and i12) mn reaches its highest values. in the inner area (a15f, a7 and f12) mn has the lowest concentrations of the whole basin. in the central area (a4, a5, and b6m), mn has intermediate concentrations. mn distribution therefore depends on the distance to the coast. a15f, a7 and f12 are more influenced by coastal environment and the river inputs (ph, eh, wave energy, sedimentation, etc.) and have low mn precipitation. b60 and i12, conversely, are in more marine environment where mn oxide precipitation is favored. a4, a5, and b6m in the intermediate environment show intermediate concentration values. this pattern is consistent with the two different mn features in z145 during glacial and holocene times, when the distance to coast varied (glasby, 2006). in level -108 cm (corresponding to the holocene reducing layer) and in level -215 cm (corresponding to the beginning of the holocene), mn reaches the lowest concentrations (6-9%) in the organic fraction and it shows similar values (24-31%) in the residual fraction (tab. 5, fig. 4b). the sum of percentage values of the oxidized and carbonate fractions is nearly constant (6367%), the mn distribution in each fraction being influenced by its oxidation state (mn +2 in carbonate phase and mn +4 in oxi-hydroxides minerals). at -108 cm (6.7 cal ka bp), mn is mainly concentrated in the carbonate phase, in agreement with the recognized environmental anoxic conditions that hampered the formation of mn oxides (petrie, 1999; callender, 2003; glasby, 2006). it must be emphasized that during the anoxic period the environmental reducing conditions were strong so that the mn value in the oxide phase is below the detection limit. conversely, at -215 cm (about 10.9 cal ka bp) the 74 fig. 5 map of mn mean concentration areas in recent sediments of the study area. blue area = mn concentration between 2500 and 1500 ppm. green area = mn concentration between 1500 and 800 ppm. yellow area = mn concentration between 800 and 500 ppm. ruscito v. et al marine conditions are attained, partially hampering the precipitation of the mn. the mean fe concentration in b60 (tab. 3) is about 12% less than the holocene mean in z145 (tab. 2a). a similar decrease (about 15%) is also recognizable in all other recent sediments (tab. 4), probably due to the presence of continuous iron mining activity in the tuscan mining district since the etruscan age. mineral exploitation reached the maximum during the industrial age and had ended by the mid-twentieth century. mining probably caused significant decrease in the total average fe content in the environment. in both z145 and b60 (tab. 5), fe is mainly concentrated in the residual fraction (95-99%), and it is only represented in small percentages in the organic and oxide portions. the low presence of the oxide fraction is probably due to the chemical-reducing attack that is not sufficiently strong to dissolve the iron oxides. all the fe, then, is nearly attributed to the residual phase. 6. discussion chemical analyses performed in this study, together with previous isotopic and micropaleontological studies, allow the identification of two reducing layers deposited in the central tyrrhenian sea. anoxic conditions occur thanks to the favorable position of the sampling site within the continental platform, at about 150 m depth during high-stand periods, facing three river mouths, in a basin where water exchanges are weakpercentage of mn+4 in the oxide fraction is higher than the percentage of the mn+2 in the carbonate phase. this feature corresponds to “normal” oxidized sedimentation in a not fully marine environment, as the sea level was yet lower than the present and the sampling site was nearer to the coast. in b60, as in z145, most of mn concentrates in carbonate and oxide fractions with nearly constant values of about 86-90%. in the superficial level, the mn value in the oxide fraction reaches 41%, sharply decreasing in the sub superficial levels. below the level 1.5 cm, mn mainly is in the reduced form (mn+2), strongly enriched in the carbonate fraction, in agreement with fully marine condition (glasby, 2006). 5.3. fe in core z145, the fe and mn trends (fig. 3b) are similar, due to the redox conditions found in this depositional environment (williamson, 1999; callender, 2003; haese, 2006; martinez-ruiz et al., 2015). before the glacial-holocene transition their values strictly correlate (r=0.9) and are still in good agreement during the first phase of the holocene (r=0.8) (see fig. 6 a, b). in glacial and holocene anoxic periods, data show very low eh values inducing the reduction of fe. mn and fe dissolve and follow the same trend. similar correlations are found also by olivieri et al. (2013) in anoxic sediments. after the end of the holocene reducing layer, the onset of oxidizing conditions caused a progressive difference between the fe and mn trends (fig. 3b): the mn concentrations increase toward the top of the core, while fe does not follow this trend. these trends also occur in recent sediments, such as in b60 and f12. in core b60, there is no correlation between mn and fe (tab. 3 and fig. 6c), because the elements have different behaviors in oxidizing conditions. mn-fe, instead, show a weak correlation (r=0.6) in f12 (fig. 5d and tab.6), due to the localization of this site near to the coast where not fully 75 tab. 6 mn and fe/100 concentrations in box-core f12. fig. 6 fe-mn correlations in ombrone cores. a) fe-mn correlation in z145 during the glacial period. b) fe-mn correlation in z145 during the holocene period. c) fe-mn correlation in b60. d) fe-mn correlation in f12. evidence of anoxic layers in the central tyrrhenian sea between 29 and 4.2 ka. ened by few submerged highs such as the elba ridge. in this situation, the influence of the enhanced continental runoff, mostly of the ombrone river supply, was strong enough to create reducing environments, leading to some sapropel-type levels. 6.1. holocene reducing layer former micropaleontological and isotopic analyses (carboni et al., 2005) and new trace element data agree in highlighting the presence of a reducing layer in the studied area during the holocene. this anoxia period is characterized by phase of enhanced productivity (carboni et al., 2005), with an increase of sr (fig. 2b) from 17 to 44 cm/ka. the toc content rises from about 0.5-0.6% up to about 1% (ruscito personal communication), a typical value of west mediterranean orls (rogerson et al., 2008; fink et al., 2013). faunal assemblages highlight a change in the marine circulation regime from well-mixed eutrophic to stratified oligotrophic waters in a temporal range spanning from about 7.4 to 5.2 cal ka bp (carboni et al., 2005). the lighter δ18o values (tab. 1, fig. 3) mark the increased freshwater input from 7.1 cal ka bp to slighlty after 5.7 cal ka bp. at about 6.8 cal ka bp, the reducing conditions became strong enough to produce a remarkable pb precipitation and its concentration shows a temporal range of enrichment comprised between 6.8 and 5.7 cal ka bp, peaking at 6.2 cal ka bp (tab. 2a, fig. 3a). low mn values (fig. 3b, tab. 2a) suggest the presence of reducing conditions at ~6.7 cal ka bp, while the concentration peak at 6.2 cal ka bp probably does not coincide with the end of the anoxia period, but rather represents a post depositional re-oxidation of the sediment by bioturbation (rey et al., 2008), as high pb concentration shows that reducing conditions were present at least until 5.7 cal ka bp. this difference of about 500 years corresponds to ~ 20 cm of reworked sediment, in agreement with reitz et al., (2006). the ranges of all proxies mostly overlap, defining the chronological boundaries of the orl. pb shows the narrower time span, highlighting the climax of the period between 6.8 and 5.7 cal ka bp. among our investigated parameters, the pb concentration, not influenced by postdepositional re-oxidation, is acknowledged to be the best marker to detect the climax of the anoxic period. this period is almost synchronous with the sapropel layer s1b (7.4-6.4 cal ka bp) found by bakrač et al. (2018) in lake vrana (croatia) corresponding to an increased freshwater discharge, and also with the maximum level at lake medina (6.2-5.8 cal ka bp) found in the sw iberian peninsula by schröder et al. (2018). it also partially overlaps with a main increase of alpine floods found by sabatier et al. (2017), thus highlighting its regional significance over the mediterranean basin. our data agree with the enhanced rainy period recognized by many authors in the west central mediterranean area (zanchetta et al., 2007; tinner et al., 2009; spötl et al., 2010; zhornyak et al., 2011; fletcher et al., 2013; toucanne et al., 2015; bakrac et al., 2018), taking into account some delay between the increase of precipitations on the continental sites and the development of oligotrophic and reducing conditions on the sea floor (di donato et al., 2019). holocene anoxia period found in the ombrone submerged delta also partially overlaps with the last phases of sapropel s1 found in the east mediterranean (grimm et al., 2015; grant et al., 2016; tesi et al., 2017; swingedown et al., 2019; wu et al., 2019), showing that enhanced freshwater runoff during sapropel formation was not restricted to the eastern mediterranean but was rather widespread over the entire mediterranean region, including its northern borderlands. moreover, it suggests that in the west mediterranean region this “pluvial” period reached its maximum during the last phases of sapropel s1b formation in the east. in the ligurian basin (north tyrrhenian sea) in the 11-6 ka period, enhanced rivers activity and low ventilated bottom sea waters occurred. moreover, during the last 6 ka, a windy cooler climate improved the bottom water reoxygenation (le houedec et al., 2021), in good agreement with our paleoclimatic reconstruction from the ombrone submerged delta. 6.2. glacial reducing layer despite the scarcer resolution due to the low sedimentation rate (fig. 2b), at about 27.2 cal ka bp another anoxic period, of similar intensity of the holocene one, was hypothesized basing on trace element data. here high pb concentrations are found, and pb reaches 309 ppm (tab. 2b and fig. 3a), a value close to that observed in the holocene anoxic layer, about 13 times higher than the mean of other glacial values (24 ppm). this suggests that chemical and physical conditions were similar. based on an estimated sea level of about 120-130 m below the current one (alessio et al., 1994; capozzi et a., 2009; clark et al., 2009), during the glacial period the distance between the ombrone river mouth and the sampling site was about 7 km and the water depth about 20-30 m. this setting emphasized the coastal supplies, although the hydrological cycle and the river runoff were probably weaker than during the holocene. the enhanced pb concentration at 27.2 cal ka bp is synchronous with a phase marked by the increase of the warm-water species g. bulloides (carboni et al., 2005) and by decreasing of δ18o ratios (tab. 1, fig. 3). these data highlight a warmer and wetter fluctuation during the late glacial (svensson et al., 2008; guilizzoni et al., 2014; oliva et al., 2018). this climatic amelioration probably induced an increased freshwater supply that produced in our area a stratified column with reducing conditions, involving pb precipitation. 8. conclusions new trace element data performed on marine sediments collected on the ombrone submerged delta (central tyrrhenian sea), complement the previously published paleoenvironmental reconstruction in the area between 29 and 4.2 cal ka bp and allows the reconstruction of changing oxidation condition at the sea bottom. fe, mn and pb contents proved to be powerful tools for recognizing periods of anoxia in the basin, being particularly sensitive to environmental variations of ph and eh conditions. we found that pb was the most 76 ruscito v. et al tin, 62, 1041-1052. doi: 10.1016/j.marpolbul.2011.02.030 bakrač k., ilijanić n., miko s., hasan o. (2018) evidence of sapropel s1 formation from holocene lacustrine sequences in lake vrana in dalmatia (croatia). quaternary international, 494, 5-18. doi: 10.1016/j.quaint.2018.06.010 bard e., delaygue g., rostek f., antonioli f., silenzi s., schrag d.p. (2002) hydrological conditions over the western mediterranean basin during the deposition of the cold sapropel 6 (ca. 175 kyr bp). earth and planetary science letters, 202, 481494. doi: 10.1016/s0012-821x(02)00788-4 bazzicalupo p., maiorano p., girone a., marino m., combourieu-nebout n., incarbona a. (2018) high-frequency climate fluctuations over the last deglaciation in the alboran sea, western mediterranean: evidence from calcareous plankton assemblages. palaeogeography, palaeoclimatology, palaeoecology, 506, 226-241. doi: 10.1016/j.palaeo.2018.06.042 bellotti p., caputo c., davoli l., evangelista s., garzanti e., pugliese f., valeri p. (2004) morpho -sedimentary characteristics and holocene evolution of the emergent part of the ombrone river delta (southern tuscany). geomorphology, 61 (12), 71-90. doi: 10.1016/j.geomorph.2003.11.007 belluomini g., branca m., improta s., manfra l., ruscito v., vesica p., voltaggio m. (2002) il sistema deltizio del fiume ombrone: determinazione delle velocità di sedimentazione mediante metodi radiometrici. studi costieri, 5, 35-45. bergamin l., celia magno m., chiocci f.l., di bella l., la monica g.b., landini b. (2001) stratigrafia dell’immediato sottofondo marino antistante il fiume ombrone. conference bilancio sedimentario dei sistemi costieri italiani. processi naturali ed influenze antropiche, porto d’ischia, may, 15-17, 2001. abstract book. beyin a., prendergast m.e., grillo k.m., wang h. (2017) new radiocarbon dates for terminal pleistocene and early holocene settlements in west turkana, northern kenya. quaternary science reviews, 30, 1-18. doi: 10.1016/j.quascirev.2017.04.012 bini m., zanchetta g., persolu a., cartier r., català a., cacho i., dean j.r., di rita f., drysdale r.n., finnè m., isola i., jalali b., lirer f., magri d., masi a., marks l., mercuri a.m., peyron o., sadori l., sicre m-a., welc f., zielhofer c., brisset e. (2019) the 4.2 ka bp event in the mediterranean region: an overview. climate of the past, 15, 555577. doi: 10.5194/cp-15-555-2019 blanchet c.l., osborne a.h., tjallingii r. ehrmann w., friedrich t., timmermann a., brückmann w., frank m. (2021) drivers of river reactivation in north africa during the last glacial cycle. nature geoscience, 14, 97-103. doi: 10.1038/s41561-020-00671-3 callender e. (2003) heavy metals in the environment: sensitive proxy to identify environmental sapropel-type (i.e. anoxic) conditions, with total concentrations reaching high anomalous values (about 9 times the present background) during specific past periods, even though this area in the last century has been affected by anthropic pollution, mainly from mining activities and leadadded fuel that increased the natural pb background. in agreement with previous data, two reducing periods have been recognized. the first occurs during the glacial at about 27,2 cal ka bp. the second occur during the holocene between 7.4 and 5.2 cal ka bp, with a climax between 6.8 and 5.7 cal ka bp, identifying a sapropel-type sedimentation phase. the formation of the anoxic layer in the ombrone submerged delta during the glacial period was favored by the geomorphological conditions of a semi-enclosed basin, where water exchanges with the open sea were weakened. formation of this layer is also related to the increased vicinity of the site to the river mouth during the marine low-stand, that allowed increased freshwater supply. the holocene reducing layer was probably a consequence of an intense rainfall period in the westcentral mediterranean area, representative of the climatic situation of the northern mediterranean region, perhaps with some influences from the southern part of the region. the holocene anoxic period partially overlaps with the last phases of sapropel s1b found in the east mediterranean, suggesting that the humid climate during sapropel formation was not restricted to the eastern mediterranean, but was rather widespread over the entire mediterranean region, although the highest rainfall phases were not strictly synchronous in the two basins. the comparison with this paleoenvironmental reconstruction in a period not affected by human activity could help to evaluate anthropic influences in current environmental conditions and to make predictions of future developments. acknowledgements we would like to thank prof. f.l. chiocci, who provided us with samples collected as part of the cnr marine campaigns. we also thank prof. b. landini and dr c. tarragoni for their aid in the sample classification. dr. voltaggio and another anonymous reviewer are acknowledged for their positive comments to the first versione of the ms. references adamson k.r., hughes p.d., woodward j.c. (2013) pleistocene glaciation of the mediterranean mountains. quaternary newsletters, 131, 1-15. alessio m., allegri l., antonioli f., belluomini g., improta s., manfra l., preite-martinez m. (1994) la curva di risalita del mare tirreno negli ultimi 43 ka ricavata da datazioni di speleotemi sommersi e dati archeologici. memorie descrittive della carta geologica d’italia, 52, 261-276. angelidis m.o., radakovitch o., veron, a., aloupi m., heussner s., price b. (2011) anthropogenic metal contamination and sapropel imprints in deep mediterranean sediments. marine pollution bulle 77 evidence of anoxic layers in the central tyrrhenian sea between 29 and 4.2 ka. https://doi.org/10.1016/j.marpolbul.2011.02.030 https://doi.org/10.1038/s41561-020-00671-3 historical trends. in: lollar b.s., ed. environmental geochemistry, treatise on geochemistry. oxford: elsevier-pergamon, 9, 67-105. doi: 10.1016/b0-08-043751-6/09161-1 capozzi r., negri a. (2009) role of sea-level forced sedimentary processes on the distribution of organic carbon-rich marine sediments: a review of the late quaternary sapropels in the mediterranean sea. palaeogeography, palaeoclimatology, palaeoecology, 373, 249-257. doi: 10.1016/j.palaeo.2008.05.009 cappuynsv., swennen r., niclaes m. (2007) application of the bcr sequential extraction scheme to dredged pond sediments contaminated by pb-zn mining: a combined geochemical and mineralogical approach. journal of geochemical exploration. 93, 78-90. doi: 10.1016/j.gex-plo.2006.10.001 carboni m.g., bellotti p., bergamin l., di bella l., matteucci r. (2000) benthic foraminiferal assemblages from the ombrone and tiber deltas: a preliminary comparison. géologie méditerranéenne, 27 (1-2), 3-13. doi: 10.3406/geolm.2000.1662 carboni m.g., bergamin l., di bella l., landini b., manfra l., vesica p. (2005) late quaternary paleoclimatic and paleoenvironmental changes in the tyrrhenian sea. quaternary science reviews, 24, 2069-2082. doi: 10.1016/j.quascirev.2004.09.009 carlson a.e. (2013) the younger dryas climate event in “the encyclopedia of quaternary science”, 3, 126-134. elias s.a. (ed), elsevier. doi: 10.1016/b978-0-444-53643-3.00029-7 clark p.u., dyke a.s., shakun j.d., carlson a.e., clark j., wohlfarth b., mitrovica j.x., hostetler s.w., mccabe a.m. (2009) the last glacial maximum. science, 325, 710-714. colonese a.c., zanchetta g., fallik a.e., manganelli g., saña m., alcade g., nebot j. (2013) holocene snail shell isotopic record of millennial-scale hydrological conditions in western mediterranean: data from bauma del serrat del pont (ne iberian peninsula). quaternary international, 303, 43-53. doi: 10.1016/j.quaint.2013.01.019 conforto l., manfra l. (2004) heavy metals chronological and area trends of shelf marine sediments in central tyrrhenian sea (tuscany italy). geochimica et cosmochimica acta. abstract of the 13th goldschmit conference, a524.4.65. p03. conforto l, manfra l. (2007) heavy metals in the submerged ombrone river delta (central tyrrhenian sea italy). geoitalia. sesto forum italiano di scienze della terra, 71. conforto l., manfra l., corrado l. (2008) holocene and present-days heavy metals in central tyrrhenian sea sediments. 33° international geological congress oslo. poster. di donato v., insinga d.d., iorio m., molisso f., rumolo p., cardines c., passaro s. (2019) the palaeoclimatic and palaeoceanographic history of the gulf of taranto (mediterranean sea) in the last 15 ky. global planetary change, 172, 278-297. doi: 10.1016/j.gloplacha.2018.10.014 di rita f., fletcher w.j., aranbarri j., margaritelli g., lirer f., magri d. (2018) holocene forest dynamics in central and western mediterranean: periodicity, spatio-temporal patterns and climate influence. scientific reports, 8, 8929. doi: 10.1038/s41598-018-27056-2 domínguez-villar d., carrasco r.m., pedraza j., cheng h., edwards r.l., willenbring j.k. (2013) early maximum extent of paleoglaciers from mediterranean mountains during the last glaciation. scientific reports, 3, 2034. doi: 10.1038/srep02034 drab l., carlut j., hubert-ferrari a., martinez p., lepoint g., el ouahabi m. (2015) paleomagnetic and geochemical record from cores from the sea of marmara, turkey: age constraints and implications of sapropelic deposition on early diagenesis. marine geology, 360,40-54. doi: 10.1016/j.margeo.2014.12.002 dubois-dauphin q., montagna p., siani g., douville e., wienberg c., hebbeln d., liu z., kallel n., dapoigny a., revel m., pons-branchu e., taviani m., colin c. (2017) hydrological variations of the intermediate water masses of the western mediterranean sea during the past 20 ka inferred from neodymium isotopic composition in foraminifera and cold-water corals. climate of the past, 13, 1737. doi: 10.5194/cp-13-17-2017 fiedel s.j. (2011). the mysterious onset of the younger dryas. quaternary international, 242, 262-266. doi: 10.1016/j.quaint.2011.02.044 filippidi a., triantaphyllou m.v., de lange g.j. (2016) eastern-mediterranean variability during sapropel s1 formation, evaluated at two sites influenced by deep-water formation from adriatic and aegean seas. quaternary science reviews, 144, 95-106. doi: 10.1016/j.quascirev.2016.05.024 fink h.g., wienberg c., de pol-holz r., wintersteller p., hebbeln d. (2013) cold-water coral growth in the alboran sea related to high productivity during the late pleistocene and holocene. marine geology, 339, 71-81. doi: 10.1016/j.margeo.2013.04.009 fletcher w.k. (1981) analytical methods in geochemical prospecting. handbook of exploration geochemistry,1. elsevier, amsterdam, holland. gallego-torres d., martinez-ruiz f., de lange g.j., jimenéz-espejo f.j., ortega-huertas m. (2010) trace-elemental derived paleoceanographic and paleoclimatic conditions for pleistocene eastern mediterranean sapropels. palaeogeography, palaeoclimatology, palaeoecology, 293, 76-89. doi: 10.1016/j.palaeo.2010.05.001 geraga m., ioakim c. lykousis v., tsaila-monopolis s., mylona g. (2010) the high-resolution palaeoclimatic and palaeocenographic history of the last 24,000 years in the central aegean sea, greece. palaeogeography, palaeoclimatology, palaeoecology, 287, 101-115. doi: 10.1016/j.palaeo.2010.01.023 glasby g.p. (2006) manganese: predominant role of 78 ruscito v. et al https://doi.org/10.1016/j.palaeo.2008.05.009 https://doi.org/10.1038/s41598-018-27056-2 https://doi.org/10.1038/srep02034 http://dx.doi.org/10.1016/j.margeo.2014.12.002 westernmost mediterranean over the last 20 kyr bp and its impact on the mediterranean outflow. global planetary change, 135, 38-46. doi: 10.1016/j.gloplacha.2015.10.001 kandiano e.s., bauch h.a., fahl k. (2014) last interglacial surface water structure in the western mediterranean (balearic) sea: climatic variability and link between low and high latitudes. global and planetary change, 123(a), 67-76. doi: 10.1016/j.gloplacha.2014.10.004 keigwin l.d., klotsko s., zhao n., reilly b., giosan l., driscoll n.w. (2018) deglacial floods in the beaufort sea preceded younger dryas cooling. nature geoscience, 11, 599-604. doi: 10.1038/s41561-018-0169-6 kennet d.j., aura tortosa j.e., bischoff j.l. daniel i.r., erlandson s. (2015) bayesian chronological analyses consistent with synchronous age of 12,835-12,735 cal b.p. for younger dryas boundary on four continents. proceedings of the national academy of sciences (pnas), 112, 4344-4353. doi: 10.1073/pnas.150714611 kidd r.b., cita m.b., ryan w.b.f. (1978) stratigraphy of eastern mediterranean sapropel sequences recovered during dsdp leg 142 and their paleoenvironmental significance. initial reports of the deep sea drilling project, 42, 421-443. kotthoff u., pross j., müller u.c., peyron o., schmiedl g., schulz h., bordon a. (2008) climate dynamics in the borderlands of the aegean sea during formation of sapropel s1 deduced from a marine pollen record. quaternary science reviews, 27, 832-845. doi: 10.1016/j.quascirev.2007.12.001 le houedec s., mojtahid m., ciobanu m., jorry s.j., bouhdayad f.z., guyonneau e., sourice s., toucanne s. (2021) deglacial to holocene environmental changes in the northern ligurian sea: the dual influence of regional climate variability and large-scale intermediate mediterranean circulation. palaeogeography, palaeoclimatology, palaeoecology, 576, 110500. doi: g/10.1016/j.palaeo.2021.110500 lionello p., malanotte-rizzoli p., boscolo r. (eds.) (2006) mediterranean climate variability. elsevier. lirer f., sprovieri m., ferraro l., vallefuoco m., capotondi l., cascella a., petrosino p., insinga d.d., pelosi n., tamburrino s., lubritto c. (2013) integrated stratigraphy for the late quaternary in eastern tyrrhenian sea. quaternary international, 292, 71-85. doi: 10.1016/j.quaint.2012.08.2055 magny m., vannière b., calo c., millet l., leroux a., peyron o., zanchetta g., la mantia t., tinner w. (2011) holocene hydrological changes in southwestern mediterranean as recorded by lake-level fluctuations at lago preola, a coastal lake in southern sicily, italy. quaternary science reviews, 30, 2459-2473. doi: 10.1016/j.quascirev.2011.05.018 martinez-ruiz f., kastner m., gallego-torres m., ortega -huertas m. (2015) paleoclimate and paleoceanography over the past 20,000 yr in the mediterranodules and crust. marine geochemistry. schulz h.d., zabel m. (eds), springerberlin-heidelberg new york, 371-415. doi: 10.1007/3-540-32144-6_11 grant k.m., grimm r., mikolajewicz u., marino g., ziegler m., rohling e.j. (2016) the timing of mediterranean sapropel deposition relative to insolation, sea-level and african monsoon changes. quaternary science reviews, 140, 125-141. doi: 10.1016/j.quascirev.2016.03.026 grimm r., maier-reimer e., mikolajewicz u., schmiedl g., müller-navarra k., adloff f. m., grant k.m., ziegler m., lourens l.j., emeis k.c. (2015) late glacial initiation of holocene eastern mediterranean sapropel formation. nature communications, 6, article number: 7099. doi: 10.1038/ncomms8099 gromig r., mechernich s., ribolini a., wagner b., zanchetta g., isola i., bini m., dunai t.j. (2018) evidence for a younger dryas deglaciation in the galicia mountains (fyrom) from cosmogenic 36cl. quaternary international, 464, 352-363. doi: 10.1016/j.quaint.2017.07.013 guilizzoni p., lami a., marchetto a., ariztegui d. (2014) lakes. in: litho-paleaoenvironmental maps of italy during the last two climate extremes. researchgate.net/publication/262484813. haese r.r. (2006) the reactivity of the iron. marine geochemistry, schulz h.d., zabel m., (eds), springerberlin-heidelbergnew york, 241-264. heimbürger l.e., cossa d., thibodeau b., khripounoff a., mas, v., chiffoleau j.f., schmidt s., migon c. (2012) natural and anthropogenic trace metals in sediments of the ligurian sea (northwestern mediterranean). chemical geology, 291, 141-151. doi: 10.1016/j.chemgeo.2011.10.011 hennekam r., jilbert t., schnetger b., de lange g.j. (2014) solar forcing of nile and sapropel s1 formation in the early to middle holocene eastern mediterranaean. paleoceanography and paleoclimatology, 29 (5), 343-356. incarbona a., sprovieri m. (2020) the postglacial isotopic record of intermediate water connects mediterranean sapropels and organic-rich layers. paleoceanography and paleoclimatology, 35, 1-20. doi: 10.1029/2020pa004009 isola i., zanchetta g., drysdale r.n., regattieri e., bini m., bajo p., hellstrom j.c., baneschi i., lionello p., woodhead j., greig a. (2019) the 4.2 ka bp event in the central mediterranean: new data from corchia speleothems (apuan alps, central italy). climate of the past, 15, 135-154. doi: 10.5194/cp-15-135-2019 ivy-ochs s., kerschner h., reuther a., preusser f., heine k., maisch m., kubik p.w., schlüchter c., (2008) chronology of the last glacial cycle in the european alps. journal of quaternary science, 23 (6-7), 559-573. doi: 10.1002/jqs.1202 jiménez-espejo f.j., pardos-gené m., martínez-ruiz f., garcía-alix a., van de flierdt t., toyofuku t., bahr a., kreissig k. (2015) geochemical evidence for intermediate water circulation in the 79 evidence of anoxic layers in the central tyrrhenian sea between 29 and 4.2 ka. https://doi.org/10.1016/j.palaeo.2021.110500 https://doi.org/10.1029/2020pa004009 nean sea basin as indicated by sediment elemental proxies. quaternary science reviews, 107, 25-46. doi: 10.1016/j.quascirev.2014.09.018 mcculloch m., taviani m., montagna p., lópez correa m., remia a., mortimer g. (2010) proliferation and demise of deep-sea corals in the mediterranean during the younger dryas. earth and planetary science letters, 298, 143-152. doi: 10.1016/j.epsl.2010.07.036 melki t., kallel n., jorissen f.j., guichard f., dennielou b., berné s., labeyrie l., fontugne m. (2009) abrupt climate change, sea surface and paleoproductivity in the western mediterranean sea (gulf of lion) during the last 28 kyr. palaeogeography, palaeoclimatology, palaeoecology, 279, 96-113. doi: 10.1016/j.palaeo.2009.05.005 mihaljevic m. (1999) lead. encyclopedia of geochemistry. marshall c.p., fairbridge r.w. (eds), kluwer academic publishers dordrecht-boston, 362-363. naimo d., adamo p., imperato m., stanzione d. (2005) mineralogy and geochemistry of a marine sequence, gulf of salerno italy. quaternary international, 140, 53-63. doi: 10.1016/j.quaint.2005.05.004 negri a., colleoni f., masina s. (2012) mediterranean sapropels: a mere geological problem or a resource for the study of a changing planet ? alpine and mediterranean quaternary, 25 (2), 81-89. oliva m., žebre m., guglielmin m., hughes p.d., çiner a., vieira g., bodin x., andrés n., colucci r.r., garcía-hernández c., mora c., nofre j., palacio d., pérez-alberti a., ribolini a., ruizfernández j., sarıkaya m.a, serrano e., urdea p., valcárcel m., woodward j.c., yıldırım c. (2018) permafrost conditions in the mediterranean region since the last glaciation. earth-science reviews, 185, 397-436. doi: 10.1016/j.earscirev.2018.06.018 olivieri e., sprovieri m., manta d.s., giaramita l., la cono v., lirer f., rumolo p., sabatino n., tranchida g., vallefuoco m., yakimov m.m., mazzola s. (2013) sediment geochemistry of the thetis hypersaline anoxic basin (eastern mediterranean sea). sedimentary geology, 296, 72-85. doi: 10.1016/j.sedgeo.2013.08.007 pasquier v., toucanne s., sansjofre p., dixit y., revillon s., mokeddem z., rabineau m. (2019) organic matter isotopes reveal enhanced rainfall activity in northwestern mediterranean borderland during warm substages of the last 200 kyr. quaternary science reviews, 205, 182-192. doi: 10.1016/j.quascirev.2018.12.007 pauly m., helle g., miramont c., büntgen u., treydt k., reinig f., guibal f., sivan o., heinrich i., riedel f., kromer b., balanzategu d., wacker l., sookdeo a., brauer a. (2018) subfossil trees suggest enhanced mediterranean hydroclimate variability at the onset of the younger dryas. scientific report, 8, 13980. doi: 10.1038/s41598-018-32251-2 pérez asensio j.n., frigola j., pena l.d., sierra f.j., reguera m.l., rodrfguez­tovar f.j., dorador j., asioli a., kuhlmann j., huhn k., cacho i. (2020) changes in western mediterranean thermohaline circulation in association with a deglacial organic rich layer formation in the alboran sea. quaternary science reviews, 228, 103527. doi: 10.1016/j.quascirev.2019.106075 petrie l.m. (1999) manganese. encyclopedia of geochemistry. marshall c.p., fairbridge r.w. (eds), kluwer academic publishers dordrecht-boston, 382-384. reimer p.j., austin w.e.n., bard e., bayliss a., blackwell p.g., bronk ramsey c.b., butzin m., cheng h., edwards r.l., friedrich m., grootes p.m., guilderson t.p., hajdas i., heaton t.j., hogg a.g., hughen k.a., kromer b., manning s.w., muscheler r., palmer j.g., pearson c., van der plicht j., reimer r.w., richards d.a., scott e.m., southon j.r., turney c.s.m., wacker l., adolphi f., büntgen u., capano m., fahrni s.m., fogtmann-schulz a., friedrich r., köhler p., kudsk s., miyake f., olsen j., reinig f., sakamoto m., sookdeo a., talamo, s. (2020) the intcal20 northern hemisphere radiocarbon age calibration curve (0-55 cal kbp). radiocarbon, 62(4), 725-757. doi: 10.1017/rdc.2020.41 reitz a., thomson j., de lange g., hensen c. (2006) source and development of large manganese enrichments above eastern mediterranean sapropel s1. paleocenography and paleoclimatology, 21, pa 3007. doi: 10.1029/2005pa001169 rey d., rubio b., mohamed k., vilas f., alonso b., ercilla g., rivas t. (2008) detrital and early diagenetic processes in the late pleistocene and holocene sediments from the sw galicia bank inferred from high-resolution enviromagnetic and geochemical records. marine geology, 249, 64-92. doi: 10.1016/j.margeo.2007.09.013 ribolini a., bini m., isola i., spagnolo m., zanchetta g., pellitero r., mechernich s., gromig r., dunai t., wagner b., milevski i. (2018) an oldest dryas glacier expansion on mount pelister (former yugoslavian republic of macedonia) according to 10be cosmogenic dating. journal of the geological society, 175, 100-110. doi: 10.1144/jgs2017-038 rodrigo-gámiz m., martinez-ruiz f., jimenés-espejo f.j., gallego-torres d., nieto-moreno v., romero o., ariztegui d. (2011) impact of climate variability in the western mediterranean during the last 20,000 years: oceanic and atmospheric responses. quaternary science reviews, 30, 2018-2034. doi: 10.1016/j.quascirev.2011.05.011 rogerson m., cacho i., jimenéz-espejo f., reguera m. i., sierro f.j., martinez-ruiz f., frigola j., canals m. (2008) a dynamic explanation for the origin of the western mediterranean organic-rich layers. geochemistry geophysics geosystems, 9(7), q07u01. doi: 10.1029/2007gc001936 rohling e.j. (1994) review and new aspects concern 80 ruscito v. et al https://doi.org/10.1038/s41598-018-32251-2 https://doi.org/10.1016/j.quascirev.2019.106075 study from lake medina (cadiz, sw spain). quaternary science reviews, 198, 208-225. doi: 10.1016/j.quascirev.2018.08.030 seguinot j., ivy-ochs s., jouvet g., huss m., funk m., preusser f. (2018) modelling last glacial cycle ice dynamics in the alps. the cryosphere, 12, 3265-3285. doi: 10.5194/tc-12-3265-2018 shakun j.d., carlson a.e. (2010) a global perspective on last glacial maximum to holocene climate change. quaternary science reviews, 29, 18011816. doi: 10.1016/j.quascirev.2010.03.016 spötl c., nicolussi k., patzelt g., boch r., team d. (2010) humid climate during deposition of sapropel s1 in the mediterranean sea: assessing the influence on the alps. global and planetary change, 71, 242-248. doi: 10.1016/j.gloplacha.2009.10.003 svensson a., andersen k.k., bigler m., clausen h.b., dahl-jensen d., davies s.m., johnsen s.j., muscheler r., parrenin f., rasmussen s.o., röthlisberger r., seierstad i., steffensen j.p., vinther m.b. (2008) a 60000 year greenland stratigraphic ice core chronology. climate of the past, 4, 47-57. doi: 10.5194/cp-4-47-2008 tesi t., asioli a., minisini d., maselli v., dalla valle g., gamberi f., langone l., cattaneo a., montagna p., trincardi f. (2017) large-scale response of the eastern mediterranean thermohaline circulation to african monsoon intensification during sapropel s1 formation. quaternary science reviews, 159, 139-154. doi: 10.1016/j.quascirev.2017.01.020 thomson j., higgs n.c., wilson t.r.s., croudace i.w., de lange g.j., van santvoort p.j.m. (1995) redistribution and geochemical behaviour of redoxsensitive elements around s1, the most recent eastern mediterranean sapropel. geochimica et cosmochimica acta, 59, 3487-3501. doi: 10.1016/0016-7037(95)00232-o tinner w., van leeuwen j.f.n., colombaroli d., vescovi e., van der knaap w.o., henne p.d., pasta s., d’angelo s., la mantia t. (2009) holocene environmental and climatic changes at gorgo basso, a coastal lake in southern sicily, italy. quaternary science reviews, 28, 1498-1510. doi: 10.1016/j.quascirev.2009.02.001 tortora p. (1999) sediment distribution on the ombrone river delta seafloor anrelated dispersal processes. geologica romana, 35, 211-218. toucanne s., angue minto’o c.m., fontanier c., bassetti m. a., jorry s.j., jouet g. (2015) tracking rainfall in the northern mediterranean borderlands during sapropel deposition. quaternary science reviews, 129, 178-195. doi: 10.1016/j.quascirev.2015.10.016 triantaphyllou m.v. (2014) coccolithophore assemblages during the holocene climatic optimum in the ne mediterranean (aegean and northern levantine seas, greece): paleoceanographic and paleoclimatic implications. quaternary internationing the formation of eastern mediterranean sapropels. marine geology, 122, 1-28. doi: 10.1016/0025-3227(94)90202-x rohling e.j., hilgen f.j. (1991) the eastern mediterraneanclimate at times of sapropel formation: a review. netherlands journal of geosciences, 70, 253 -26 rohling e.j., pälike h. (2005) centennial-scale climate cooling with a sudden cold event around 8,200 years ago. nature, 434, 975-979. doi: 10.1038/nature03421 rohling e.j., marino g., grant k.m. (2015) mediterranean climate and oceanography, and the periodic development of anoxic events (sapropel). earth science reviews, 143, 62-97. doi: 10.1016/j.earscirev.2015.01.008 rossignol-strick m. (1985) mediterranean quaternary sapropels, an immediate response of the african monsoon to variation of insolation. palaeogeography, palaeoclimatology, palaeoecology, 49, issues 3-4, 237-263. doi: 10.1016/0031-0182(85)90056-2 rossignol-strick m., nesteroff w., olive p., vergnaudgrazzini c. (1982) after the deluge: mediterranean stagnation and sapropel formation. nature, 295, 105-110. doi: 10.1038/295105a0 roveri m., correggiari a. (2004) submerged depositional terraces in the tuscan archipelago (eastern margin of the corsica basin). memorie descrittive della carta geologica d’italia, 58, 11-16. sabatier p., wilhelm b., ficetola g.f., moiroux f., poulenard j., develle a.-l., bichet a., chen w., pignol c., reyss j-l., gielly l., bajard m., perrette y., malet e., taberlet p., arnaud f. (2017) 6-kyr record of flood frequency and intensity in the western mediterranean alps interplay of solar and temperature forcing. quaternary science reviews, 170, 121-135. doi: 10.1016/j.quascirev.2017.06.019 sahuquillo a.j.f., lópez-sánchez r., rubio g., rauret r.p., thomas c.m., davidson a., ure m. (1999) use of a certified reference material for extractable trace metals to assess sources of uncertainty in the bcr three-stage sequential extraction procedure. analytica chimica acta, 382, 317-327. doi: 10.1016/s0003-2670(98)00754-5 sarikaya m.s., ҫiner a. (2015) late quaternary glaciations in the eastern mediterranean. geological society, london, special publications, 433, 289305. doi: 10.1144/sp433.4 schemmel f., niedermeyer e.m., schwab v.f., gleixner g., pross j., mulch a. (2016) plant wax δd values record changing eastern mediterranean atmospheric circulation patterns during the 8.2 kyr b.p. climatic event. quaternary science reviews, 133, 96-107. doi: 10.1016/j.quascirev.2015.12.019 schröder t., van‘t hoff j., lopez-saez j.a., viehberg f., melles m., reicherter k. (2018) holocene climatic and environmental evolution on the southwestern iberian peninsula: a high-resolution multi-proxy 81 evidence of anoxic layers in the central tyrrhenian sea between 29 and 4.2 ka. https://doi.org/10.1016/j.quascirev.2015.10.016 https://doi.org/10.1016/j.quascirev.2017.06.019 al, 345, 1-12. doi: 10.1016/j.quaint.2014.01.033 tribovillard n., algeo t.j., lyons t., riboulleau a. (2006) trace metals as paleoredox and paleoproductivity proxies: an update. chemical geology, 232, 12-13. doi: 10.1016/j.chemgeo.2006.02.012 trigo i.f., bigg g.r., trevor d.d. (2002) climatology of cyclogenesis mechanisms in the mediterranean. monthly weather review, 130, 3, 549-569. doi: 10.1175/1520-0493(2002)130<0549:cocmit >2.0.co;2 turner p., margaritz m. (1986) chemical and isotopic studies of a core of marl slate from ne england: influence of freshwater influx into the zechstein sea. geological society, london, special publications, 22, 1, 19-29. doi: 10.1144/gsl.sp.1986.022.01.03 wagner b., vogel h., francke a., friedrich t., donders t., lacey j.h., leng m.j., regattieri e., sadori l., wilke t., zanchetta g., albrecht c., bertini a., combourieu-nebout n., cvetkoska a., giaccio b., grazhdani a., hauffe t., holtvoeth j., joannin s., jovanovska e., just j., kouli k., kousis i., koutsodendris a., krastel s., lagos m., leicher n., levkov z., lindhorst k., masi a., melles m., mercuri a.m., nomade s., nowaczyk n., panagiotopoulos k., peyron 0., reed j.m., sagnotti l., sinopoli g., stelbrink b., sulpizio r., timmermann a., tofilovska s., torri p., wagnercremer f., wonik t., zhan x. (2019) mediterranean winter rainfall in phase with african monsoons during the past 1.36 million years. nature, 573, 256-260. doi: 10.1038/s41586-019-1529-0 warning b., brumsack h.j. (2000) trace metals signatures of eastern mediterranean sapropels. palaeogeography, palaeoclimatology, palaeoecology, 158, 293309. doi: 10.1016/s0031-0182(00)00055-9 williamson m.a. (1999) iron. encyclopedia of geochemistry. marshall c.p., fairbridge r.w. (eds), kluwer academic publishers dordrecht-boston, 348-353. williams m.a.j., duller g.a.t., williams f.m., woodward j.c., macklin m.g., el tom o.a.d., munro r.n., el hajaz y., barrows t.t. (2015) causal links between nile floods and eastern mediterranean sapropel formation during the past 125 kyr confirmed by ols and radiocarbon dating of blue and white nile sediments. quaternary science reviews, 130, 89-108. doi: 10.1016/j.quascirev.2015.05.024 wu j., liu z., stuut j.b.w., zhao y., de lange g.j. (2017) north-african paleodrainage discharges to central mediterranean during the last 18,000 years: a multiproxy characterization. quaternary science reviews, 163, 95-113. doi: 10.1016/j.quascirev.2017.03.015 wu j., pahnkec k., böningc p., wu l., michardd a., de lange g.j. (2019) divergent mediterranean seawater circulation during holocene sapropel formation reconstructed using nd isotopes in fish debris and foraminifera. earth and planetary science letters, 511, 141-153. doi: 10.1016/j.epsl.2019.01.036 zanchetta g., drysdale r.n., hellstrom j.c., fallick a.e., isola i., gagan m.k., pareschi m.t. (2007) enhanced rainfall in the western mediterranean during deposition of sapropel s1: stalagmite evidence from corchia cave (central italy). quaternary science reviews, 26, 279-286. doi: 10.1016/j.quascirev.2006.12.003 zhang c., yu z.-g, zeng g.-m., jiang m., yang z.-z., cui f., zhu m.-y., shen l.-q., hu l. (2014) effect of sediment geochemical properties on heavy metal bioavailability . environmental international, 73, 270-280. doi: 10.1016/j.evint.2014.08.010 zhornyak l.v., zanchetta g., drysdale r.n., hellstrom j.c., isola i., regattieri e., piccini l., baneschi i., couchoud i. (2011) stratigraphic evidence for a “pluvial phase” between ca 8200-7100 ka from renella cave (central italy). quaternary science reviews, 30, 409-417. doi: 10.1016/j.quascirev.2010.12.003 82 ms. received: april 17, 2024 revised: may 17, 2024 accepted: may 24, 2024 available online: june 14, 2024 ruscito v. et al https://doi.org/10.1016/j.quascirev.2006.12.003 sess 2_16022011_tpr3.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 weathering in pleistocene badlands from ionian calabria, southern italy iolanda pulice 1 paola di leo 2, gaetano robustelli 1, fabio scarciglia 1, francesco cavalcante 2 & claudia belviso 2 1 dipartimento di scienze della terra, università della calabria, arcavacata di rende (cs) 2 istituto di metodologie per l’analisi ambientale, cnr, tito scalo (pz) corresponding author: i. pulice <pulicei@unical.it> abstract: pulice i. et al., weathering in pleistocene badlands from ionian calabria, southern italy. (it issn 039-3356,2011) this work investigates the main factors and processes that control geochemistry and mineralogy of clay lithotypes affected by calanchi landforms in the area of caulonia (rc), in southern calabria. in the present study are shown the results obtained from a multidisciplinary study that integrates geomorphologic, chemical and mineralogical data by means of a multivariate statistic analysis using the principal component analysis (pca) method to extract factors. riassunto: pulice i. et al., studio dell’alterazione sui calanchi pleistocenici della calabria ionica, italia meridionale. (it issn 039-3356,2011) il presente lavoro è finalizzato a dare un contributo su alcuni fattori e processi che controllano la geochimica e la mineralogia dei litotipi argillosi affetti da morfologie calanchive nell’area di caulonia (rc), in calabria meridionale. vengono presentati i risultati di uno studio multidisciplinare a carattere geomorfologico, chimico e mineralogico, elaborati attraverso l’ausilio dell’analisi statistica multivariata mediante il metodo dei componenti principali (pca). key words: badlands, weathering, mineralogy-geochemistry parole chiave: calanchi; alterazione, mineralogiageochimica 1982; imeson, 1993). badlands can be distinguished in “calanchi” (morphological units with steep slopes and sharp ridges, according to alexander, 1982), “biancane” (dome-shaped small hills affected by rills and salt efflorescence), and transitional forms between calanchi and biancane (alexander, 1982; sdao et al., 1984) 1. introduction badland landforms are very common in pliopleistocene marine clays of southern italy. associated morphologies are typical of arid or semi -arid climates, but were also found in different conditions (e.g. berael et al., 1993; bryan & yair, fig.1, orthogonal plot of the pca using as variables in the input matrix the calculated weathering indices. diagramma ortogonale della pca utilizzando come variabili nella matrice di input gli indici di alterazione.  123 125 124 2. methods following interpretation of aerial photos at 1:33,000 scale and a geomorphological survey, clay lithotypes were sampled in a selected calanchi catchment near caulonia, for subsequent laboratory analyses, which included the measurement of specific properties. sampling was performed with special rules designed to characterize specific microforms, such as the outer crust and the inner massive portion of the substratum (pulice et al., 2009). on the bulk sample (< 2 mm) and the clay fraction (< 2 µm) a qualitative mineralogical analysis was performed by x-ray diffraction (xrd) on powder and oriented specimens, respectively. it was carried out with a rigaku d/max-2200/pc (cu-kα radiation, graphite secondary monochromator and sample spinner). xrd analyses on oriented clays were made on air-dried, glycolated, and heated at 375°c specimens. a software (mcdiff4.2) using the jcpds (joint committee on powder diffraction standards) mineralogical database was applied for the identification of mineral phases. chemical analyses were performed using xrf spectrometry and on the basis of metal oxides several weathering indices, commonly used in comparing the extent of chemical alteration, were calculated (i.e. ciw = chemical index of weathering, and other indices based on ratios between silica or bases vs other oxides, e.g. al2o3, fe2o3, tio2, etc.). 3. results and discussion among the main mineral phases identified, clay minerals dominate, followed by quartz, calcite, kfeldspar and plagioclase. illite, illite/smectite (i/sm) mixed layers, kaolinite and chlorite are the main clay minerals identified. xrf data exhibit higher values of silica, alumina and calcium. in order to asses the main factors controlling the development of weathering in the studied pleistocene badland a multivariate statistical approach, using the principal component analysis (pca) method to extract factors, have been carried out. in fig. 1a are shown the results from the multivariate statistical analysis carried out using in the input matrix the calculated weathering indices. these indices are based on the principle that the ratio between concentrations of mobile (such as sio2, cao, mgo, and na2o) and immobile elements (al2o3, fe2o3, tio2) should decrease several authors described badlands in details and attempt to interpret the main factors and causes of their triggering and development, particularly in the mediterranean climate. the role of tectonics, human impact, vegetation and land-use changes, physical, chemical and mineralogical properties of the lithology among which dispersivity (deflocculation) and expandability of clays (battaglia et al., 2002; gerits et al., 1997) as well as the development of the surface crust and pipes (faulkner et al., 2000; harvey am. 1982) were investigated. the aim of the present work is to asses the main factors controlling the development of weathering in pleistocene badlands affecting shallow-marine and transitional clays of late pliocene–quaternary age in se calabria (southern italy). to do this chemical and physical characteristics of 30 samples from a small calanchi catchment, located in the area of caulonia (reggio calabria, southern italy), have been compared to mineralogy. besides, a large suite of weathering indices have been also calculated for each sample. their variation has been analyzed taking into account that samples were collected at different time in the year (wet season vs dry season), on the opposite flanks of the catchment exhibiting different slopes, and from the first centimeters (surface crust) toward the internal portion (inner substratum). fig.2, orthogonal plot of the pca using as variables in the input matrix the distributions of clay minerals (wt %). diagramma ortogonale della pca utilizzando come variabili nella matrice di input le distribuzioni dei minerali argillosi. i. pulice et al. 125 ms. received: testo ricevuto il whereas the original mineral assemblage mainly made of well crystalline illite (wci), chlorite, kaolinite and quartz dominates along steep slope. the control exerted by topography is more evident in samples collected after a relatively dry winter. references alexander d. (1980) difference between ‘calanchi’ and ‘biancane’ badlands in italy. in badland geomorphology and piping, bryan r, yaira (eds). geobooks: norwich, 71–88. battaglia s., leoni l. & sartori f. (2002) mineralogical and grain size composition of clays developing calanchi and biancane erosional landforms. geomorphology 49, 153–170. berael c., poesen j. & van wesemael b. (1993) rill and gully erosion in relation to rock fragment cover and surface slope along a hillslope in south eastern spain. in desertification in a european context: physical and socio-economic aspects, fantechi r, peter d, balabanis p,rubio jl (eds). proceedings of the european school of climatology and natural hazards course, alicante, spain, from 6 to 13 october, 371–375. bryan r. & yair a (1982) (eds) badland geomorphology and piping. geobooks, norwich. faulkner h., spivey d. & alexander r. (2000) the role of some site geochemical processes in the development and stabilisation of three badland sites in almerìa, southern spain. geomorphology, 35, 87–99. gerits j., imeson a.c., verstraten j.m. & bryan r.b. (1997) rill development and badland regolith properties. in rill erosion: processes and significance, bryan rb (eds.), catena supplement., 8, 141–160. harvey a.m. (1982) the role of piping in the development of badlands and gully systems in southeast spain. in badland geomorphology and piping, bryan r, yair a (eds). geobooks: norwich, 317–335. imeson a.c. (1993) the physical, chemical and biological degradation of soil. in desertification in a european context: physical and socio-economic aspects, fantechi r, peter d, balabanis p, rubio jl (eds). proceedings of the european school of climatology and natural sdao g., simone a. & vittorini s. (1984) osservazioni geomorfologiche su calanchi e biancane in calabria. geografia fisica e dinamica del quaternario, 7, 10– 16.hazards course: alicante, spain; 6–13 october: 153–168 pulice i., scarciglia f., leonardi l., robustelli g., conforti m., cuscino m., lupiano v. & critelli s. 2009 studio multidisciplinare di forme e processi denudazionali nell’area di vrica (calabria orientale). in memorie società geografica italiana, roma: società geografica italiana, 87 (i –ii), 403-417. over time as leaching progresses. indeed, the concentrations of the most immobile elements should increase during weathering if surface erosion is negligible. given the formulations of most weathering indices, decreasing values signify greater weathering. the opposite, however, is true for ciw. the 1st component (78% of explained variance), grouping together the weathering indices based mainly on silica vs alluminia and tio2 relationships, has the highest statistical load in distinguishing the first sampling after a relatively dry winter season from the second one after repeated heavy rainy winters. the amount of sio2 usually decreases in weathered materials because it is somewhat soluble, though less than cao, mgo, k2o, and na2o. alumina has a low solubility under normal weathering ph, so its relative proportion generally increases in weathered materials. titania generally increases in relative proportion, as it is essentially insoluble in most weathering environments. the remaining major elements (k, na, mg and ca) decrease as weathering proceeds. some of these cations are temporarily bound in clay minerals, but as the clay minerals themselves weather, the remaining alkali and alkaline earths are progressively released. only when the winter was relatively heavy rainy, it can be distinguished between surface crust and inner substratum (fig.1b). in this conditions, in fact, the rate of runoff is high. this presumably caused migration of alkalis (mobile elements) from the crust toward the substratum, which therefore appears enriched in these elements (higher ciw values in the crust than in the inner portion). on the other hand, there is no evidence of differences in weathering indices between crusts and substratum in samples collected after relatively dry winters (fig 1b). the analysis of clay mineral distributions is crucial in evidencing the control of topography on weathering of badlands from caulonia. in fig. 2 are shown the results from a second pca, carried out using in the input matrix the distributions of clay minerals (wt.%). the 1st component (50% of explained variance) well discriminates samples collected from opposite flanks of the catchment that exhibit different slopes. this suggests that topography (mainly slope and aspect, that affect rates of water runoff) likely controls the weathering of the original mineral assemblages of caulonia badlands. in fact, i/sm and poorly crystalline illite (pci) prevail in samples along gentler slope, weathering in pleistocene badlands from ionian ... january 15, 2011 15 gennaio 2011 sess 5_16022011_edi as.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 quantitative analyses have been performed in high temporal resolution (one sample per 0.6-0.8 kyr) on calcareous nannofossil assemblages from core kc01b throughout the pleistocene interval spanning marine isotope stages (mis) 9-13. this interval includes the mid-brunhes event (mbe, jansen et al., 1986), a time of significant climate modification that experienced a warm and prolonged interglacial, mis 11, considered the modern analogous of the holocene. the mbe is also characterized by an increase of atmospheric co2 and a global increased caco3 accumulation mainly linked to enhanced coccolithophores production associated with a high proliferation of gephyrocapsa genus in many oceanic settings (barker et al., 2006, cum biblio). the core kc01b, recovered by r/v marion dufresne at the water depth of 3643 meter in the ionian sea, represents a reference section for pleistocene chronostratigraphy due to its continuous sedimentary record and richness in sapropel and tephra layers which contributed to establish the astronomical tuned neogene time scale (lourens et al., 2004). the analyses revealed that the nannofossil assemblages mainly consist of gephyrocapsa caribbeanica and g. muellerae, differently from the living and surface sediment associations recorded in mediterranean sea (knappertsbusch, 1993). gephyrocapsa may reach up to 90% in the total assemblages. other abundant taxa are “small placoliths”, and florisphaera profunda, a deep dweller photic zone taxon indicative of deep nutricline (molfino & mcintyre, 1990). these taxa have been used to obtain a paleoproductivity proxy (n index) according to flores et al. (2000). comparison of abundance patterns of all taxa and n index with the planktonic oxygen isotope curve (rossignolstick et al., 1998; lourens, 2004) provides details on the meaning of species fluctuations through the glacial/interglacial cycles. the pattern of classical “warm and oligotrophic” taxa does not have a clear positive relation with interglacials as it occurs in the oceans, suggesting a primary response to oligotrophic conditions rather than to temperature changes. in addition it shows opposite trends with respect to n index that has high values mainly during interglacials and glacial/interglacial transitions, especially from mis 12 to mis 11. g. muellerae mainly increases during glacial periods, in agreement with its known ecological preference for cold surface waters (bollmann, 1997), whereas g. caribbeanica has higher abundance during interglacials and at the transition mis 12/11, thus implying ecological preference for eutrophic and nutrient-rich surface waters during the investigated interval, according to lopez-otalvaro et al. (2008). a distinct interval of absence or extreme rarity of taxa indicative of warm and stratified surface waters (i.e. umbilicosphaera sibogae) has been recorded through late mis 12 and lower mis 11 when also f. profunda decreases, suggesting persistent cold/cool conditions up to about 410 kyr in the early interglacial mis 11, before the lowest calcareous nannofossil assemblages at core kc01b (ionian sea) through oxygen marine isotope stages 9-13 francesca tarantino1, patrizia maiorano1, maria marino1, gert j. de lange2 & lucas lourens2 1 dipartimento di geologia e geofisica, università degli studi di bari “aldo moro”, bari 2 department of earth sciences – geochemistry, faculty of geosciences, utrecht university corresponding author: f. tarantino <francescatarantino@libero.it> abstract: tarantino f. et al., calcareous nannofossil assemblages at core kc01b (ionian sea) through oxygen marine isotope stages 9-13 (it issn 0394-3356, 2011). calcareous nannofossil assemblages from deep sea core kc01b in ionian sea have been analysed in high sample resolution (0.6-0.8 kyr) through the pleistocene marine isotope stages (mis) 9-13 interval, which includes significant climate changes during the known mid-brunhes event. collected data show complex relationships between coccolithophores modification and environmental parameters. riassunto: tarantino f. et al., associazioni a nannofossili calcarei durante gli stadi isotopici 9-13 nella carota kc01b (mar ionio) (it issn 0394-3356, 2011) sono state studiate le associazioni a nannofossili calcarei nella carota di mare profondo kc01b recuperata nel mar ionio. le analisi, condotte in alta risoluzione temporale (0,6-0,8 kyr) indicano complesse relazioni the le modificazioni delle associazioni e i cambiamenti dei parametri ambientali durante un intervallo di importanti variazioni climatiche conosciuto come mid-brunhes event. key words: calcareous nannofossils, ionian sea, core kc01b, mis 9-13. parole chiave: nannofossili calcarei, mar ionio, carota kc01b, mis 9-13 219 220 220 ms. received: testo ricevuto il values of d18o (at about 405 kyr); also unstable and more productive conditions may have occurred at mis 12/11 transition. distinct peaks of helicosphaera carteri mark the mis 12/11 transition which seem in agreement with its ecological preferences for decreased salinity and high turbidity level (colmenero-hidalgo et al. 2004) and possible r-selected life strategy. these results agree with the higher primary productivity during glacial-interglacial transitions documented in oceanic setting by liu et al. (2003) who also retain that higher biogenic calcification (planktonic foraminifers and coccoliths) may lead the lightest δ18o. the preliminary data of the present study indicate that the modifications of nannofossil assemblages have relation with the global climate changes known in oceans during the investigated interval; however additional environmental factors different from the temperature alone (the complex local ionian hydrography, the variability of surface atlantic water influence at the core location, the nutrient availability in the photic zone) have to be considered to fully explain the poorly known paleoecology of selected taxa in mediterranean sea. references barker s., archer d., booth l., elderfield h., henderiks j. & rickaby r. e. m. (2006) globally increased pelagic carbonate production during the mid-bruhnes dissolution interval and the co2 paradox of mis 11. quaternary science reviews, 25, 3278-3293. bollman j. (1997) morphology and biogeography of gephyrocapsa coccoliths in holocene sediments. marine micropaleontology, 29, 319350. colmenero-hidalgo e., flores j.a., sierro j., barcena m.a., lowemark l., schonfeld j. & grimalt j.o. (2004) ocean surface water response to short-term climate changes revealed by coccolithophores from the gulf of cadiz (ne atlantic) and alboran sea (w mediterranean). paleogeogr. paleoclim. paleoecol. 205, 317–336. flores j.a., gersonde r., sierro f. j. & niebler h.-s. (2000) southern ocean pleistocene calcareous nannofossil events: calibration with isotope and geomagnetic stratigraphies. marine micropaleontology, 40, 377-402. knappertsbusch m. (1993) geographic distribution of living and holocene coccolithophores in the mediterranean sea. marine micropaleontology, 21, 219 247. jansen j.h.f., kuijpers a. & troelstra s.r. (1986) a mid-brunhes climatic event: longterm changes in global atmosphere and ocean circulation. scienze 2, vol. 232, no. 4750, 619 – 622. lópez-otálvaro g. e., flores j. a., francisco javier sierro f. j. & cacho i. (2008) variations in coccolithophorid production in the eastern equatorial pacific at odp site 1240 over the last seven glacial–interglacial cycles. marine micropaleontology, 69, 52–69. liu z., xu j., tian j. & wang p. (2003) calcium carbonate pump during quaternary glacial cycles in the south china sea. chinese science bullettin, 48 (17), 1862-1869. lourens l. (2004) revised tuning of ocean drilling program site 964 and kc01b (mediterranean) and implications for the d18o, tephra, calcareous nannofossil, and geomagnetic reversal chronologies of the past 1.1 myr. paleoceanography, 19, pa3010. lourens l., hilgen f., shackleton n. j., laskar j. & wilson, d. (2004) the neogene period, in: gradstein f. m., ogg j. g., & smith a. g. (eds) a geological time scale. cambridge university press, 409–440. molfino b. & mcintyre a. (1990) nutricline variation in the equatorial atlantic coincident with the younger dryas. paleoceanography, 5 (6), 997 -1008. rossignol-strick m., paterne m., bassinot f., emeis k.-c. & de lange g. j. (1998) an unusual mid-pleistocene monsoon period over africa and asia. nature, 392, 269-272. f. tarantino et al. january 14, 2011 14 gennaio 2011 impaginatoinsinga ssttrraattiiggrraaffiiaa ee ccaarraatttteerriissttiicchhee ffiissiicchhee ddeeii ddeeppoossiittii oolloocceenniiccii ddeell ppoorrttoo ddii mmiisseennoo,, ggoollffoo ddii ppoozzzzuuoollii ((ttiirrrreennoo cceennttrroo--oorriieennttaallee)) dd.. iinnssiinnggaa 11**,, aa.. ddii mmeegglliioo 22,, ff.. mmoolliissssoo 11 && mm.. ssaacccchhii 11**** 1 istituto di ricerca geomare sud cnr, via amerigo vespucci, 9 80142 napoli 2 technodata s.r.l., via cinthia, p.co s. paolo, is. 20 80126 – napoli *insinga@gms01.geomare.na.cnr.it; **sacchi@gms01.geomare.na.cnr.it riassunto l’analisi di cinque carotaggi profondi (30÷40 m) effettuati nello specchio d’acqua del porto di miseno (settore occidentale dei campi flegrei), insieme con la datazione di due livelli di torba (14c ams) ed una serie di prove geotecniche in sito e su campioni indisturbati, ha consentito di ricostruire l’assetto stratigrafico della successione olocenica campionata al di sotto del fondo mare e di determinare le caratteristiche fisiche e meccaniche dei sedimenti. sulla base dei risultati ottenuti sono state delineate le principali fasi evolutive di questa piccola insenatura del golfo di pozzuoli durante gli ultimi 10.000 anni. la successione carotata, costituita prevalentemente da sabbie di natura vulcanica, è caratterizzata da un trend generale trasgressivo localmente interrotto da due episodi di regressione forzata legati al rapido accumulo di depositi piroclastici più o meno sviluppati. gli episodi regressivi terminano con la formazione di due livelli di torba rinvenuti all’interno dell’unità b ed al passaggio tra le unità d ed e, e le cui misure radiometriche hanno fornito un’età di 3560±40 anni e 7815±55 anni, rispettivamente. ciò permette di correlare tali livelli con due importanti fasi di quiescenza dell’attività vulcanica dei campi flegrei documentate in letteratura. il controllo geocronologico fornito dalle datazioni assolute, consente, inoltre, una stima dei tassi di sedimentazione durante l’olocene medio-superiore, i quali sono mediamente dell’ordine di 3.5 m/ka per le unità inferiori (e-d) e di 2.2 m /ka per quelle superiori (b-a). la successione olocenica di porto miseno può essere correlata con una serie di unità sismo-stratigrafiche individuate nel settore centrale ed in quello orientale della piattaforma continentale del golfo di pozzuoli e con la sezione affiorante lungo la scarpata d’erosione del terrazzo marino de la starza, nel settore emerso dei campi flegrei, dove la successione olocenica è stata sollevata di circa 40 m sopra il livello del mare durante gli ultimi 4000 anni. abstract the stratigraphic study of five deep cores (30-40 m) drilled in the harbor of miseno (western flegrean fields), along with radiometric age dating (14c ams) of two peat layers and a number of geotechnical tests, allowed for the reconstruction of the stratigraphic framework and the determination of physical and mechanical properties of the holocene succession beneath the sea floor. based on these data we outline the evolution of the study area during the last 10.000 years. the holocene succession of porto miseno is characterized by transgressive volcanic sandy deposits which include a 1÷5 m thick pyroclastic unit (unit c). two resting phases, which closes regressive episods, are testified by two peat layers which have been cored within unit b (layer t1) and at the transition between units d and e (layer t2). samples collected from the peat layers yielded radiometric ages of 3560±40 years b.p. and 7815±55 years b.p., respectively. this suggests a correlation between the cored peat layers and two paleosols documented on land that are associated with resting periods during the volcanic activity of flegrean fields. chronostratigraphic constraints, based on these radiocarbon age determinations, allowed for the evaluation of sedimentation rates during late holocene, which are in the order of 3.5 m/ka for the lower units (e-d) and 2.2 m /ka for the upper part of the section (units b-a). the holocene deposits of porto miseno can be correlated with distinct seismic-stratigraphic units identified in the subsurface of the southern and central sectors of pozzuoli bay. they can be also correlated with the section cropping out onshore, along the erosional slope of “la starza” terrace, where the marine holocene sequence has been uplifted about 40 m above the sea level in the last few thousand years. parole chiave: golfo di pozzuoli, campi flegrei, olocene, caratteristiche geotecniche, età radiometrica key words: pozzuoli bay, flegrean fields, holocene, geotechnical properties, radiometric age. il quaternario italian journal of quaternary sciences 1155(1), 2002, 11-21 11.. iinnttrroodduuzziioonnee il settore costiero del mar tirreno centro-orientale è caratterizzato dalla presenza diffusa di resti archeologici e di strutture portuali di età classica greca e romana (ca 2000-3000 anni b.p.) che si rinvengono oggi per lo più sommersi o, comunque, a quote differenti rispetto a quelle della loro originaria realizzazione ed ubicazione funzionale. ciò a testimonianza di importanti variazioni che hanno interessato il livello relativo del mare e la linea di costa della campania (alessio et al., 1994), in particolare nel settore dei campi flegrei, nel corso delle ult ime decine di centinaia di anni (dvorak & mastrolorenzo, 1991). diversi studi dimostrano che circa 2000 anni fa il livello del mare era all’incirca 0.5 m più basso di quello attuale e che poi è rapidamente risalito con tassi di circa 0.75 mm/anno tra il 50 b.c. e l’a.d.150 (pirazzoli, 1976). un’ulteriore complicazione per la ricostruzione degli spostamenti della linea di costa nell’area oggetto di studio durante l’olocene è rappresentata poi dalla notevole instabilità tettonica dell’area circostante l’abita12 insinga et al. to di pozzuoli, la quale è stata interessata, anche in epoca storica, da ripetute e talora drammatiche fasi di sollevamento e di subsidenza (barberi et al.,1984). nel settore settentrionale del golfo di pozzuoli compreso tra baia e punta miseno si rinvengono frequentemente manufatti, resti di reperti o costruzioni di età romana (ville, piscine e banchine d’attracco) ad una profondità compresa tra i 9 ed i 7 m al di sotto del livello medio del mare (caputo, 1989). per l’area dell’attuale porto di miseno (comune di bacoli), già base della flotta imperiale romana dal i al iv secolo d.c., è stato calcolato un innalzamento relativo del livello del mare, in gran parte imputabile a subsidenza tettonica, di circa 9 m negli ultimi 2000 anni (dvorak & mastrolorenzo, 1991). tra il vii ed l’xi sec., nel periodo di massima ingressione marina, legata a fenomeni di bradisismo, si registrano massimi di subsidenza dell’ordine di 11-12 m (cinque et al., 1991). nel corso del 1998, l’istituto di ricerca “geomare sud” del cnr di napoli ha svolto una serie di campagne di indagini dirette ed indirette al fine di ricostruire la stratigrafia dei depositi olocenici nei golfi di napoli e di pozzuoli (aiello et al., 1999; 2000). in particolare, nell’area di porto miseno, a sud dell’abitato di pozzuoli, sono stati effettuati cinque carotaggi profondi, di cui uno a terra e quattro nello specchio d’acqua antistante la banchina, che hanno raggiunto una profondità massima di 34 m al di sotto del l.m.m. l’esecuzione dei carotaggi è stata accompagnata da una serie di prove geotecniche sia in sito che in laboratorio e dalla determinazione dell’età radiometrica (14c ams) di due campioni di torba che hanno consentito di inquadrare la successione studiata da un punto di vista cronostratigrafico. la granulometria mediamente grossolana dei depositi carotati e le tecniche di perforazione adottate, non hanno consentito il recupero di campioni sufficientemente indisturbati per il riconoscimento delle strutture sedimentarie minori, le quali sono state in parte obliterate nel corso delle operazioni di carotaggio. e’ stato possibile, tuttavia, ricostruire l’esatto spessore stratigrafico fig. 1. schema vulcano-tettonico dei campi flegrei e del golfo di pozzuoli con l’ubicazione del porto di miseno e dell’area studio (modificato da rosi & sbrana, 1987; milia, 2000). volcano-tectonic sketch map of the flegrean fields and pozzuoli bay showing the location of porto miseno and the study area. dei diversi depositi incontrati ed il recupero di segmenti di carota, anche di considerevole lunghezza, pressoché indisturbati. ciò ha permesso non solo di ricostruire l’assetto litostratigrafico della successione campionata, ma anche di delineare le principali fasi evolutive di questa piccola insenatura nel corso degli ultimi 10.000 anni. 22.. iinnqquuaaddrraammeennttoo ggeeoollooggiiccoo l’area di porto miseno ricade nel settore occidentale del distretto vulcanico dei campi flegrei che si sviluppa in corrispondenza di un alto morfostrutturale del basamento meso-cenozoico del margine occidentale dell’appennino campano (fig. 1). l’attività vulcanica dei campi flegrei è legata alla tettonica distensiva che ha interessato il margine tirrenico orientale durante il quaternario e di cui la piana campana ed il golfo di napoli rappresentano alcuni tra i principali elementi morfotettonici (ippolito et al.,1973; ortolani & aprile, 1978; milia, 1996; aiello et al., 1999). dall’inizio della sua attività (c.a.50.000 anni b.p.), questo distretto è stato caratterizzato da una serie di manifestazioni vulcaniche e dallo sviluppo di numerosi centri eruttivi monogenici con chimismo ad affinità potassica (di girolamo et al., 1984). uno degli elementi strutturali più caratteristici dell’area dei campi flegrei è rappresentato da una depressione ampia 12 km (orsi et al., 1996), comunemente interpretata come il risultato dell’evoluzione di un sistema calderico, all’interno della quale si è manifestata gran parte dell’attività vulcanica recente conclusasi con l’eruzione del monte nuovo nel 1538 a.d. (di vito et al., 1987). l’andamento dell’originale bordo calderico è individuabile a terra in corrispondenza di una serie di scarpate discontinue alte diverse decine di metri, mentre nel settore sommerso, a sud del golfo di pozzuoli, coincide probabilmente con i banchi vulcanici di miseno, nisida e penta palummo (colantoni et al., 1972; pescatore et al., 1984; milia, 1998) l’attività vulcanica di tipo esplosivo nell’area di miseno si è esplicata prevalentemente tra 12.0 e 9.5 ka b.p. (i epoca, di vito et al., 1999) ed ha determinato lungo il bordo della struttura calderica, la formazione di “tuff rings” e “tuff cones” di cui porto miseno e capo miseno rappresentano alcuni relitti rispettivamente. questi apparati di modeste dimensioni, pur essendo oggi quasi completamente distrutti a seguito di collassi vulcano-tettonici e dell’erosione marina che hanno interessato il settore costiero in esame nelle ultime migliaia di anni, conferiscono all’area i tratti caratteristici di un sistema craterico collassato. in particolare, l’originaria morfologia è ancora riconoscibile nella forma circolare dell’insenatura del porto di miseno. i suddetti apparati vulcanici sono costituiti principalmente da alternanze di strati di scorie di varie dimensioni miste a pomici immerse in una matrice cineritica più o meno abbondante ed a luoghi resa coerente da un processo di diagenesi e di cementazione secondaria (zeolitizzazione). in alcune zone, lungo i versanti di questi apparati vulcanici sono visibili, infatti, graduali passaggi da facies piroclastiche giallastre litoidi a facies grigiastre notevolmente meno coerenti. 33.. iinnddaaggiinnii eesseegguuiittee ee ddaattii rraaccccoollttii la campagna di indagini è consistita in una serie di prove sia in sito che in laboratorio. queste hanno permesso di ricostruire l’evoluzione stratigrafica dell’area, di caratterizzare da un punto di vista geotecnico i depositi campionati e di datare con il metodo del radiocarbonio due livelli di torba recuperati dai campioni di carotaggio. in figura 2 è indicata l’ubicazione dei cinque carotaggi realizzati, mentre in tabella 1 sono indicati, per ciascuno di essi, le quote di boccaforo riferite al livello medio del mare, le profondità raggiunte, il numero dei campioni indisturbati prelevati ed il numero di prove penetrometriche eseguite. 3.1. carotaggi i carotaggi, denominati con la sigla mgf, hanno raggiunto una profondità massima di 40 m, per una lunghezza complessiva di perforazione effettuata di circa 170 m ed una percentuale di recupero di circa 76 %. per i l recupero dei campioni sono state utilizzate attrezzature a rotazione munite di carotiere semplice del diametro esterno di 101 mm ed adoperate, dove necessario, 13stratigrafia e caratteristiche fisiche... fig. 2. ubicazione dei cinque carotaggi effettuati in località porto miseno utilizzati in questo studio (mgf 1-mgf 5). location of five cores drilled in the porto miseno area (mgf 1-mgf 5) analyzed in this study. 14 colonne di rivestimento del diametro esterno di 127 mm. per i carotaggi effettuati in mare (mgf 2-5) si è operato da un pontone galleggiante, munito di mensola a sbalzo per facilitare le operazioni di montaggio delle aste ed il recupero del sondaggio. dai fori di trivellazione è stato estratto un carotaggio più o meno continuo che, sistemato in apposite cassette catalogatrici, è stato poi utilizzato per la descrizione litostratigrafica. sono stati quindi prelevati una serie di campioni indisturbati adoperando un campionatore tipo shelby, del diametro di 90 mm e della lunghezza di 70 cm, infisso a pressione previo avanzamento del rivestimento e pulitura del foro. nel corso delle operazioni di carotaggio sono state, inoltre, eseguite prove penetrometriche tipo standard penetration test (s.p.t.) i cui risultati vengono riportati in tabella 2. 3.2 analisi granulometriche e prove geotecniche i 25 campioni indisturbati recuperati sono stati sottoposti in seguito ad una serie di prove geotecniche di laboratorio al fine di determinare 1) le caratteristiche fisiche (umidità naturale w, peso dell’unità di volume γ, peso specifico dei granuli γs, porosità n, grado di saturazione s); 2) la distribuzione granulometrica mediante setacciatura (per la parte più grossolana) e sedimentazione (per la frazione più sottile); 3) le caratteristiche meccaniche quali coesione c ed angolo d’attrito interno ϕ, mediante prove di taglio diretto. i risultati delle prove geotecniche di laboratorio sono riportati schematicamente nelle tabelle 3 e 4. 44.. ssttrraattiiggrraaffiiaa ddeeii ddeeppoossiittii oolloocceenniiccii ddii ppoorrttoo mmiisseennoo l’analisi delle colonne stratigrafiche dei carotaggi di porto miseno consente il riconoscimento di cinque unità litostratigrafiche principali, ben definibili e correlabili a cui si intercalano due orizzonti di torba più o meno continui (fig. 3). queste unità sono rappresentate, dal basso verso l’alto da: unità e sabbie grossolane ghiaiose unità d sabbie limose pozzolaniche unità c pomici eterometriche in matrice pozzolanica unità b sabbie medio-grosse incoerenti unità a sabbie fini limose 4.1. unità e sabbie grossolane ghiaiose la parte basale della successione è caratterizzata da sabbie piuttosto grossolane, a tratti ghiaiose, con ciottoli lapidei poligenici, di colore grigio, ed abbondanti insinga et al. nnuummeerroo ddii nnuummeerroo ddii ssoonnddaaggggiioo qquuoottaa//pprrooffoonnddiittàà lluunngghheezzzzaa ccaammppiioonnii pprroovvee ((nn°°)) ((mm)) ((mm)) iinnddiissttuurrbbaattii ss..pp..tt.. mgf1 +0,75 34 5 7 mgf2 -1,20 34 5 7 mgf3 -1,50 30 5 6 mgf4 -2,00 32 5 7 mgf5 -2,50 40 5 7 ssoonnddaaggggiioo pprrooffoonnddiittàà pprroovvee ss..pp..tt.. ((nn°°)) ((mm)) ((nnsspptt)) mgf1 4,6 16 mgf1 8,0 33 mgf1 14,0 31 mgf1 18,4 25 mgf1 20,5 66 mgf1 25,6 r mgf1 34,0 70 mgf2 4,0 70 mgf2 8,0 60 mgf2 11,5 24 mgf2 15,5 7 mgf2 20,0 r mgf2 26,5 7 mgf2 34,0 31 mgf3 4,0 20 mgf3 8,0 43 mgf3 12,0 51 mgf3 16,0 30 mgf3 25,0 r mgf3 27,5 r mgf4 4,0 16 mgf4 8,0 21 mgf4 11,5 24 mgf4 16,0 59 mgf4 20,1 43 mgf4 26,6 37 mgf4 30,0 r mgf5 4,0 13 mgf5 8,0 23 mgf5 11,5 41 mgf5 16,0 55 mgf5 20,0 55 mgf5 27,5 26 mgf5 35,0 r tab. 1 quadro sintetico di quote di boccaforo, profondità raggiunte, numero di campioni indisturbati e numero di prove standard penetration test (s.p.t.) per i cinque sondaggi a carotaggio continuo effettuati nel porto di miseno. synopsis of altitude/water depth, length, number of undisturbed samples and number of standard penetration tests (s.p.t.) measurements for the cores mgf drilled in porto miseno. tab. 2. riepilogo dei risultati delle prove standard penetration test (s.p.t.) eseguite nel corso delle operazioni di carotaggio nel porto di miseno. summary of standard penetration tests (s.p.t.) measurements carried out during drilling operations at porto miseno. 15 pomici (grafico e in fig. 4). la presenza di intercalazioni di sottili livelli limosi ha favorito la formazione di un “tappo” di chiusura del tubo campionatore, consentendo il recupero dei depositi in fase di carotaggio. il grado di arrotondamento ed appiattimento dei clasti suggeriscono un ambiente deposizionale di spiaggia prossimale o di battigia. 4.2. unità d sabbie limose pozzolaniche questi sedimenti sono rappresentati da sabbie di colore grigio scuro in matrice limosa di natura vulcanica. la parte alta di questo livello è caratterizzata dalla presenza di materiale organico e da frammenti di gusci di bivalvi e gasteropodi. la parte inferiore, invece, è generalmente più povera in frazione limosa come evidenziato dal grafico d in figura 4. lo spessore carotato può raggiungere i 13 m come accade nei sondaggi mgf 2 e mgf 3. la presenza di una frazione limosa, generalmente sempre apprezzabile, suggerisce condizioni di sedimentazione in ambiente protetto di spiaggia somstratigrafia e caratteristiche fisiche... fig. 3 correlazione litostratigrafica tra i carotaggi mgf del porto di miseno. le età assolute degli orizzonti di torba t1 e t2 sono state determinate datati con il metodo del radiocarbonio. lithostratigraphic correlation among mgf cores, porto miseno. peat horizons t1 and t2 have been dated by 14c. 16 mersa. i depositi si presentano generalmente coerenti, oltre che resistenti alla perforazione. 4.3. unità c pomici eterometriche in matrice pozzolanica quest’unità raggiunge uno spessore massimo di 5 m nel carotaggio mgf 1, e si rinviene a profondità comprese tra i 14 ed i 19 m. le pomici, immerse in una matrice sabbioso-limosa di natura vulcanica, hanno dimensioni variabili (5 cm max.) (grafico c in fig. 4) e presentano, talvolta, patine di ossidazione probabilmente legate a processi di alterazione in ambiente subaereo insinga et al. fig. 4 curve granulometriche (di frequenza cumulativa) dei campioni prelevati dai carotaggi effettuati nel porto di miseno (mgf 1mgf 5). granulometric curves (cumulative frequencies) of core samples drilled at porto miseno (mgf 1-mgf 5). 17 o vadoso. la presenza, in tale livello, di granuli (ciottoli) con elevato grado di arrotondamento, suggerisce per questi depositi un ambiente di sedimentazione di spiaggia sommersa prossimale o di battigia. 4.4. unità b sabbie medio-grossolane incoerenti questi depositi clastici grossolani sono poveri in matrice (grafico b in fig. 4) e piuttosto incoerenti. essi costituiscono un’unità di spessore variabile da un minimo di 6 m ad un massimo di 10 m (sondaggio mgf 5). inclusi in tale livello si ritrovano, spesso, clasti pomicei di dimensioni variabili. si tratta dei depositi basali di un breve ciclo marino trasgressivo-regressivo che si sviluppa con una classica successione gradata passando da sabbie medio-grossolane a sabbie medie, debolmente limose, progressivamente più fini procedendo verso l’alto. 4.5. unità a sabbie fini limose rappresentano i depositi stratigraficamente più recenti che da fondo mare raggiungono una profondità media di 6 m (7.50 m nel carotaggio mgf 1 eseguito a terra). queste sabbie di natura vulcanica sono caratterizzate da una notevole presenza di resti di origine vegetale e da piccoli frammenti di gusci di molluschi. talora si ritrovano gusci di lamellibranchi (cardium sp.) ben conservati ed organizzati in veri e propri orizzonti alla base dell’unità (sondaggi mgf 2, mgf 3, mgf 5). queste caratteristiche suggeriscono un ambiente deposizionale di bassa energia di tipo spiaggia sommersa di ambiente protetto. 4.6. torbe gli orizzonti di torba rinvenuti durante le operazioni di carotaggio si ritrovano, rispettivamente, all’interno dell’unità b (orizzonte t1), a profondità comprese tra 8 e 12 m, ed al passaggio tra le unità e e d (orizzonte t2), a profondità comprese tra 26 e 31.5 m (fig.3). l’orizzonte t2 è stato raggiunto nel sondaggio mgf 1 ad una profondità di 31.5 m (campione n° 6444) mentre l’orizzonte t1 è stato carotato nel sondaggio mgf 3 ad una profondità di 9.50 m (campione n° 6445). i campioni prelevati sono stati sottoposti ad analisi per la determinazione dell’età assoluta con il metodo del radiocarbonio. per il campione n° 6444 (t1) è stata ottenuta un’età di 3565±40 anni b.p., mentre il campione n° 6445 (t2) ha fornito un’età di 7815±55 anni b.p. (fig. 3). le età misurate degli orizzonti torbosi t1 e t2 ben si correlano con le età, riportate in letteratura, di due paleosuoli che testimoniano fasi di quiescenza dell’attività vulcanica nel settore occidentale dei campi flegrei durante gli ultimi 10.000 anni (rosi & sbrana, 1987; d’antonio et al., 1999). 55.. ccaarraatttteerriissttiicchhee ffiissiicchhee ee mmeeccccaannii-cchhee ddeeii ddeeppoossiittii oolloocceenniiccii ddii ppoorrttoo mmiisseennoo i risultati ottenuti dalle prove di laboratorio e dalle indagini geotecniche in sito, riportati sinteticamente nelle tabelle 3 e 4 e con i valori medi per ogni unità riconosciuta in tabella 5, hanno fornito dati utili per la caratterizzazione delle proprietà fisiche generali e meccaniche della successione olocenica investigata, rappresentando inoltre un ulteriore criterio utile per la correlazione stratigrafica. in particolare, l’analisi delle curve granulometriche illustrate in figura 4, ha consentito di suddividere la successione di porto miseno in cinque unità litostratigrafiche principali e di evidenziarne i caratteri tessiturali ed i parametri statistici principali. 5.1. unità e sabbie grossolane ghiaiose si tratta di sabbie grossolane caratterizzate da una frazione ghiaiosa piuttosto abbondante (circa il 42%) e dalla presenza di sottili livelli più limosi intercalati che hanno facilitato le operazioni di campionamento. i depositi risultano ben addensati, con valori di nspt molto variabili e compresi tra 27 e 70. tale dispersione è probabilmente legata alle dimensioni medie dei clasti ed alla distribuzione piuttosto eterogenea delle varie classi granulometriche. i pesi dell’unità di volume γ risultano compresi tra 17.65 e 18.63 kn/m3, la porosità n presenta valori medi intorno a 39%, la coesione è nulla, mentre i valori dell’angolo di attrito interno ϕ sono mediamente di 35°. 5.2. unità d sabbie limose pozzolaniche tale livello è costituito da sabbie fini pozzolaniche con una frazione di limo variabile che in alcuni casi raggiunge il 23%. si tratta di depositi apparentemente molto compatti come testimoniato dai risultati delle prove spt eseguite, che hanno registrato valori nspt compresi tra minimi di 34 e massimi fino al rifiuto. le tabelle 3 e 4 mostrano valori di peso dell’unità di volume γ mediamente compresi tra 15.7 e 17.65 kn/m3, un valore medio di 6 kpa per la coesione c, porosità n intorno al 50% ed angoli di attrito interno ϕ tra 35° e 40°. 5.3. unità c pomici eterometriche in matrice pozzolanica tale orizzonte è rappresentato, da un punto di vista granulometrico, da una ghiaia con sabbia limosa. la porosità n di questi depositi è molto elevata (circa il 60%), ed i pesi dell’unità di volume γ si aggirano intorno ai 16.67 kn/m3. lo stato di addensamento è risultato fortemente variabile con valori di nspt compresi tra 8 e 30, mentre la prova di taglio diretto ha registrato angoli di attrito ϕ di 36° e valori di coesione c intorno a 6 kpa. 5.4. unità b sabbie medio-grossolane incoerenti i risultati delle prove di laboratorio indicano che per tali sabbie la frazione ghiaiosa è talora predominante. questi depositi sono dotati di un certo grado di addensamento con valori di nspt mediamente compresi tra 20 e 40, tipici di sabbie da mediamente addensate a dense. i valori del peso di volume γ registrati dalle prove eseguite risultano in media pari a 15.7 kn/m3 con valori minimi e massimi di 14.70 e 18.63 kn/m3 registrati, rispettivamente, in corrispondenza di orizzonti costituiti da pomici e litici. la coesione c misurata presenta un valore medio di 4 kpa, mentre l’angolo di attrito interno ϕ oscilla tra i 33° ed i 38°. 5.5. unità a sabbie fini limose la frazione limosa nelle sabbie fini è più o meno abbondante ed i filamenti vegetali, presenti in quantità considerevoli, conferiscono al complesso una certa stratigrafia e caratteristiche fisiche... compressibilità. le prove spt eseguite hanno fatto registrare valori del numero di colpi nspt compresi tra 12 e 20, caratteristici di terreni da scarsamente a mediamente addensati. dal punto di vista delle proprietà fisiche generali e meccaniche, l’unico campione analizzato in laboratorio ha evidenziato pesi dell’unità di volume γ prossimi a 14.71 kn/m3, valori di coesione c nulli ed angoli di attrito ϕ pari a 35°. 66.. ddiissccuussssiioonnee ee ccoonncclluussiioonnii l’analisi di 5 sondaggi a rotazione con carotaggio continuo (mgf 1 mgf 5), insieme con la determinazione dell’età radiometrica (14c ams) di due livelli di torba rinvenuti nella successione campionata, ha consentito di ricostruire nel dettaglio l’assetto stratigrafico della successione tardo-quaternaria della baia di miseno, nel golfo di pozzuoli, che rappresenta un settore sommerso del distretto vulcanico dei campi flegrei (fig.3). in particolare, l’area del porto di miseno è caratterizzata da una successione olocenica espansa, che è stata investigata fino ad una profondità massima di 40 m, e risulta costituita da una successione di sabbie marine più o meno limose con abbondante frazione vulcanoclastica ed intercalazioni di livelli o strati di depositi piroclastici rappresentati prevalentemente da pomici. lo studio delle campionature, condotto sia sulla base delle caratteristiche litologiche ricavate dalla descrizione dei log di carotaggio, sia utilizzando i risultati dell’analisi granulometrica dei campioni in laboratorio, ha consentito di riconoscere cinque unità litostratigrafiche principali che dal basso verso l’alto sono state distinte con lettere e-a (figg. 3 e 4). 6.1. proprietà fisiche e meccaniche l’analisi delle proprietà fisiche dei campioni ha evidenziato valori piuttosto bassi del grado di saturazio18 insinga et al. ggrraannuulloommeettrriiaa ((%% iinn ppeessoo)) ppeessoo ssppeecciiffiiccoo ppeessoo ddii ggrraaddoo ddii ssoonnddaaggggiioo ccaammppiioonnee pprrooffoonnddiittàà uummiiddiittàà ddeeii ggrraannuullii vvoolluummee ppoorroossiittàà ssaattuurraazziioonnee ((nn°°)) ((nn°°)) ((mm)) ghiaia sabbia limo + argilla ww ((%%)) γγss ((11ee++0033 kkgg//mm33)) γγ ((kknn//mm33)) nn ((%%)) ss ((%%)) 1 1 8,0-8,5 3,22 92,98 3,79 36,13 2,518 17,289 48,58 0,96 1 2 11,5-12.0 48,68 33,43 17,87 46,98 2,481 15,847 55,66 0,92 1 3 18,0-18,4 38,43 33,21 28,35 75,54 2,487 13,631 68,15 0,87 1 4 25,0-25,6 13,47 63,07 23,45 37,68 2,524 18,093 46,90 1,00 1 5 29,0-29,5 0,13 90,65 9,20 38,20 2,552 16,759 51,54 0,91 2 1 6,0-6,4 0,95 92,90 6,13 29,25 2,513 16,573 47,95 0,79 2 2 11,0-11,5 41,9 50,8 7,28 25,80 2,486 15,847 48,32 0,68 2 3 18,0-18,6 3,65 87,09 9,25 40,64 2,467 16,308 52,07 0,92 2 4 26,0-26,5 14,81 62,30 22,87 41,99 2,384 14,778 55,49 0,80 2 5 30,0-30,5 4,06 91,82 4,11 21,58 2,521 19,034 36,66 0,93 3 1 6,0-6,5 0,78 86,58 12,63 26,69 2,491 19,034 38,51 1,00 3 2 10,0-10,6 31,59 63,86 4,54 19,01 2,495 14,641 49,71 0,47 3 3 17,5-17,8 8,73 83,50 7,76 39,27 2,548 17,279 50,34 0,98 3 4 24,5-25,0 0,65 95,57 3,76 56,61 2,384 15,514 57,37 0,99 3 5 29.0-29,3 0,4 88,92 10,66 54,71 2,353 15,592 56,31 0,99 4 1 6,0-6,5 5,54 91,28 3,16 18,73 2,510 14,670 49,81 0,47 4 2 11,0-11,5 21,16 71,58 7,24 26,55 2,478 15,690 48,96 0,68 4 3 18,0-18,6 0,59 95,85 3,54 32,43 2,524 17,416 47,17 0,91 4 4 25,0-25,6 3,98 86,03 9,71 40,98 2,300 15,926 49,89 0,94 4 5 31,0-31,5 0,84 93,46 5,66 22,52 2,523 18,750 37,88 0,93 5 1 4,0-4,5 2,78 94,10 3,10 22,37 2,622 17,563 44,16 0,74 5 2 11,0-11,5 8,17 87,48 4,33 51,03 2,413 15,475 56,69 0,94 5 3 18,0-18,6 3,53 80,87 15,59 35,19 2,507 17,278 48,02 0,95 5 4 25,0-25,5 7,14 79,68 13,17 37,20 2,522 16,709 50,84 0,90 5 5 37,0-37,5 42,33 43,17 14,9 24,65 2,486 17,769 41,52 0,86 tab. 3 risultati delle prove di laboratorio per la determinazione delle proprietà fisiche dei campioni mgf. summary of main physical properties of samples mgf as determined in laboratory. 19stratigrafia e caratteristiche fisiche... ssoonnddaaggggiioo ccaammppiioonnee pprrooffoonnddiittàà aannggoolloo ddii aattttrriittoo ccooeessiioonnee ((nn°°)) ((nn°°)) ((mm)) ϕϕ ((°°)) cc ((kkppaa)) 1 1 8,0-8,5 38 18,0 1 2 11,5-12.0 33 0,0 1 3 18,0-18,4 36 8,0 1 4 25,0-25,6 37 14,0 1 5 29,0-29,5 36 15,0 2 1 6,0-6,4 35 2,0 2 2 11,0-11,5 39 1,0 2 3 18,0-18,6 38 10,0 2 4 26,0-26,5 30 0,0 2 5 30,0-30,5 40 17,0 3 1 6,0-6,5 39 7,0 3 2 10,0-10,6 33 0,0 3 3 17,5-17,8 37 4,0 3 4 24,5-25,0 41 4,0 3 5 29.0-29,3 36 0,0 4 1 6,0-6,5 35 0,0 4 2 11,0-11,5 36 4,0 4 3 18,0-18,6 36 0,0 4 4 25,0-25,6 36 0,0 4 5 31,0-31,5 34 0,0 5 1 4,0-4,5 35 0,0 5 2 11,0-11,5 36 2,0 5 3 18,0-18,6 39 3,0 5 4 25,0-25,5 35 0,0 5 5 37,0-37,5 36 0,0 ggrraaddoo ddii ppeessoo ddii aannggoolloo ddiippoorroossiittàà ssaattuurraazziioonnee vvoolluummee aattttrriittoo ccooeessiioonnee nn ((%%)) ss ((%%)) γγ ((kknn//mm33)) ϕϕ ((°°)) cc ((kkppaa)) a sabbie fini 49,81 0,47 14,71 35,00 0,0 limose b sabbie mediogrossolane incoerenti 47,87 0,78 15,62 36,38 4,2 c pomici eterometriche in matrice pozzolanica 59,25 0,93 15,54 36,50 6,0 d sabbie limose pozzolaniche 50,48 0,93 16,67 36,50 6,6 e sabbie grossolane ghiaiose 39,70 0,90 18,24 35,00 0,0 tab. 4 risultati delle prove di laboratorio per la determinazione delle proprietà meccaniche dei campioni mgf. mechanical properties of samples mgf as determined in laboratory. tab. 5 -medie aritmetiche dei risultati delle prove di laboratorio per la determinazione delle principali proprietà fisiche e meccaniche dei campioni mgf espresse in funzione delle unità litostratigrafiche riconosciute . arithmetic mean of main physical and mechanical properties of samples mgf plotted against lithostratigraphic units. uunniittàà lliittoossttrraattiiggrraaffiicchhee ne s e dei pesi di volume γ da porre probabilmente in relazione sia ad un lieve grado di cementazione dello scheletro vetroso, che può avere talora sensibilmente ridotto la porosità efficace dei sedimenti, che alla natura vulcanoclastica dei depositi. i pesi specifici reali sono stati determinati attraverso l’uso di picnometri collegati con pompa a vuoto. in molti casi, dati i valori bassi del grado di saturazione s, si è fatto riferimento alla porosità, invece che al peso di volume γ, per valutare lo stato di addensamento dei depositi. i risultati delle prove per la determinazione delle caratteristiche meccaniche, o di parametri ad esse correlabili, quali il numero di colpi nspt della standard penetration test, sono piuttosto disomogei, fatta eccezione per la coesione c la quale è risultata sempre piuttosto bassa, in tutte le unità campionate, nonostante un certa tendenza dei depositi piroclastici pozzolanici a presentare una debole cementazione in ambiente diagenetico marino. a tale proposito va ricordato che il minimo disturbo arrecato al sedimento durante le fasi di prelievo dei campioni danneggia le tessiture sedimentarie, distruggendo conseguentemente il tenue scheletro vetroso che conferisce, invece, una certa consistenza ai sedimenti in sito. a ciò, oltre che alla scarsa cernita ed alta variabilità granulometrica dei depositi vulcanoclastici, deve probabilmente imputarsi anche l’elevata dispersione delle misure di nspt che hanno evidenziato valori molto elevati o a rifiuto. le prove di taglio sono state effettuate con tre provini per ogni determinazione, imponendo pressioni verticali rispettivamente di 150 kpa, 300 kpa e 450 kpa. i risultati di queste prove hanno fornito valori dell’angolo di attrito ϕ normalmente proporzionali alle dimensioni medie dei granuli costituenti il sedimento. 6.2. analisi di facies e stratigrafia l’analisi delle associazioni di litofacies della successione in studio indica ambienti deposizionali di transizione (spiaggia sommersa, laguna costiera) di bassa energia, dove la circolazione ristretta e l’assenza di moto ondoso e forti correnti lungo costa favoriscono l’accumulo dei depositi con frazione fine relativamente abbondante. la successione stratigrafica investigata evidenzia un’evoluzione generale trasgressiva, localmente interrotta da due brevi fasi regressive probabilmente collegate ad un rapido accumulo (giacitura primaria) e/o trasporto (con parziale rimaneggiamento) di depositi piroclastici che terminano con la formazione di due livelli di torba, denominati rispettivamente t1 e t2 (fig. 3). in particolare, il rapido accumulo delle piroclastiti dell’unità c (insinga et al., 2001), che può raggiungere uno spessore di 5 m (sondaggio mgf 1), e la conseguente diminuzione dello spazio di accomodamento disponibile per i sedimenti, determinano il passaggio da condizioni di spiaggia sommersa (unità b) a condizioni tipiche di ambiente meno profondo (unità d). tale passaggio avviene attraverso una fase di transizione in cui predominano processi di alterazione tipici di ambiente vadoso e/o subaereo, testimoniati dalle frequenti tracce e patine di ossidazione che caratterizzano i primi metri dell’unità c. ulteriore evidenza a sostegno di episodi regressivi è data proprio dallo sviluppo dei livelli torbosi i quali suggeriscono brevi episodi di emersione con formazione di insenature o lagune costiere effimere che poi evolvono nuovamente ad ambienti di spiaggia sommersa. successioni di questo genere, con depositi di transizione o continentali intercalati a sedimenti marini, sono tipiche di zone costiere in aree vulcaniche attive (lajoie & stix, 1992). nel corso dei carotaggi sono stati campionati due livelli di torba, t1 e t2, rispettivamente nei sondaggi mgf 3 (profondità 9 m, unità d) e mgf 1 (profondità 31 m, al passaggio tra le unità a e b). i campioni di torba hanno fornito età radiometriche (14c) di 3560±40 anni e 7815±55 anni rispettivamente, e risultano pertanto correlabili con due paleosuoli che testimoniano a terra fasi di quiescenza dell’attività vulcanica dei campi flegrei. in particolare, l’orizzonte t2 si correla con il paleosuolo b (8,2-4,8 ka, di vito et al., 1999) o paleosuolo p3 (8,04,6 ka, rosi & sbrana, 1987), mentre l’orizzonte t1 è correlabile alla fase di quiescenza dell’attività vulcanica tra l’eruzione di senga (3,7 ka, ghiara, 1990) e quella di monte nuovo (1538 a.d., rosi & sbrana, 1987). nessuno dei carotaggi effettuati ha raggiunto il substrato tufaceo (ca 11000 anni) che pure si rinviene estesamente in affioramento nelle aree circostanti il porto di miseno. ciò suggerisce per l’area di studio elevati tassi di sedimentazione durante l’olocene superiore, da porsi probabilmente in relazione ai processi di subsidenza e di collasso vulcano-tettonico di aree discrete del settore occidentale dei campi flegrei, di cui la piattaforma interna del golfo di pozzuoli rappresenta il settore sommerso (colantoni, 1972; pescatore et al., 1984; milia, 1998). quest’osservazione, associata alle determinazioni delle età assolute dei livelli di torba t1 e t2, intercalati ai depositi di porto miseno, indica che la base della successione carotata ha un’età probabilmente compresa tra 9.000-10.000 anni. una stima dei tassi di sedimentazione medi, negli intervalli di tempo compresi all’incirca tra 8.000 e 3.600 anni e tra 3.600 anni e l’attuale, calcolati in base agli spessori stratigrafici delle unità inferiori (a e b) e superiori (d ed e) del sondaggio mgf 1, conduce a valori di 3.5 m/ka e di 2.2 m /ka, rispettivamente. se si ammette che i tassi di sedimentazione misurati rappresentino in qualche modo il riflesso della variabilità dei volumi di materiale vulcanoclastico disponibili per l’apporto sedimentario in ambiente costiero, si può avanzare l’ipotesi che il valore inferiore del tasso di sedimentazione registrato nella parte alta della successione (unità d ed e) sia conseguenza dello scarso apporto di sedimenti vulcanoclastici nell’area per l’assenza di manifestazioni eruttive durante gli ultimi 3.6 ka. la successione olocenica di porto miseno può essere tentativamente correlata con altri depositi marini tardo-quaternari già descritti in letteratura lungo la fascia costiera dei campi flegrei. in particolare, l’unità a, e le unità b-c e d-e, discusse in questo lavoro, ben si correlano rispettivamente con le unità sismostratigrafiche g1, g2 e g3, individuate nel settore centrale ed in quello orientale della piattaforma continentale del golfo di pozzuoli (milia, 1996; 1998; milia & torrente, 2000). una correlazione possibile con successioni affioranti a terra è individuabile, inoltre, nei depositi del terrazzo marino de “la starza” presso pozzuoli dove la successione olocenica è stata sollevata di circa 40 m al di sopra del livello del mare durante gli ultimi 4000 anni (cinque et al., 1985; barra, 1991). 77.. rriinnggrraazziiaammeennttii si ringraziano il corpo della guardia di finanza per l’assistenza ed il supporto logistico fornito durante le operazioni di carotaggio sul molo e nello specchio d’acqua antistante la stazione navale di porto miseno nel comune di bacoli (na) ed i dott. alessandro conforti e gennaro sarnacchiaro per l’attiva collaborazione offerta durante le operazioni di carotaggio e nella stesura delle singole stratigrafie. gli autori sono grati inoltre a tutti i ricercatori e tecnici dell’istituto di ricerca del cnr geomare sud di napoli che, a vario titolo, hanno reso possibile lo svolgimento di questo lavoro ed all’ing. armando simonelli che ha fornito utili consigli per un corretto inquadramento dell’analisi ed interpretazione dei dati geotecnici. si desidera ringraziare ancora il prof. aldo cinque ed un revisore anonimo per i preziosi suggerimenti e spunti forniti in sede di revisione critica del manoscritto. le analisi delle proprietà fisiche e meccaniche condotte su campioni indisturbati sono state eseguite dal laboratorio ufficiale “geologia tecnica” di salerno. le determinazioni delle età assolute con il metodo del radiocarbonio (14c) dei campioni di torba sono state effettuate presso il laboratorio “isotoptech” di debrecen, ungheria. 88.. llaavvoorrii cciittaattii aiello g., budillon f., cristofalo g., d’argenio b., de alteriis g., de lauro m., ferraro l., marsella e., pelosi n., sacchi m., tonielli r., (1999): marine geology and morphobathymetry in the bay of naples, conisma, spec.vol. on the int. cong. “diversità e cambiamenti”, ischia, october 1998, springer-verlag. aiello g., budillon f., d’argenio b., de alteriis g., de lauro m., ferraro l., insinga d., marsella e., molisso f., pelosi n., sacchi m., tonielli r. (2001): nuovi dati sulla morfologia sottomarina e sedimentazione recente nel golfo di napoli (tirreno meridionale), “geologia ambientale”, volume speciale, in stampa. alessio m., allegri l., antonioli f., belluomini g., improta s., manfra l., martinez m.p. (1994): la curva di risalita del mar tirreno negli ultimi 40 ka 20 insinga et al. ottenuta mediante datazioni di speleotemi sommersi e dati archeologici, memorie descrittive della carta geologica d’italia, lliiii, 261-275. barra d., (1991): studio del pleistocene superioreolocene delle aree vulcaniche campane, tesi di dottorato, università di napoli federico ii, 298 pp. barberi f., corrado g., innocenti f., luongo g., (1984): phlegrean field 1982-1984: brief chronicle of a volcano emergency in a densely populeted area, bull.volcanol., 4477--22, 175. caputo p., (1989): attività di tutela della soprintendenza archeologica di napoli e caserta, atti ii conv. naz. archeologia subacquea. ministero beni aa.cc., roma cinque a., rolandi g., zamparell i v., (1985): l’estensione dei depositi marini olocenici nei campi flegrei in relazione alla vulcano-tettonica, boll. soc. geol. ital., 110044, 327-348. cinque a., russo f., pagano m., (1991): la successione dei terreni di età post-romana delle terme di misero (napoli): nuovi dati per la storia e la stratigrafia del bradisisma puteolano, boll.soc.geol.it, 111100, 231-244. colantoni p., del monte m., fabbri a., gallignani p., selli r. & tomadin l. (1972) ricerche geologiche nel golfo di pozzuoli, in: versino, l. (ed.), relazione sui rilievi effettuati nell’area flegrea nel 1970-71, cnr, quaderni de “la ricerca scientifica”, 83, pp. 23-76. d’antonio m., civetta l., orsi g., pappalardo l., piochi m., carandente a., de vita s., di vito m.a., isaia r., (1999): the present state of the magmatic system of the campi flegrei caldera based on a reconstruction of its behavior in the past 12 ka, journal of volcanology and geothermal research, ((9911)) 22--44, 247-268 di girolamo p., ghiara m.r., lirer l., munno r., rolandi g. & stanzione d., (1984): vulcanologia e petrologia dei campi flegrei, boll. soc. geol. it., 110033, 349-413. di vito m., lirer l., mastrolorenzo g., rolandi g., (1987): the monte nuovo eruption (campi flegrei, italy), bull. volcanol. 4499, 608-615. di vito m., isaia r., orsi g., southon j., de vita s., d’antonio m., pappalardo l., piochi m., (1999): volcanism and deformation since 12,000 years at the campi flegrei caldera (italy), journal of volcanology and geothermal research, (9911)) 22--44, 221-246. dvorak j.j. & mastrolorenzo g. (1991): the mechanisms of recent vertical crustal movements in campi flegrei caldera, southern italy, special papergeological society of america. ghiara m.r., (1990): studio evolutivo del sistema magmatico flegreo negli ultimi 10 ka, boll. soc. natur. napoli, 9988--9999, pp 30. insinga d., lanphere m., morra v., sacchi m., molisso f., ricci g., (2001): stratigraphy, 14c and 40ar/39ar geochronology, and petrochemistry of holocene deposits in an active volcanic area: the pozzuoli bay, southern italy, eug assembly, strasbourg, april 2001. ippolito f., d’argenio b., pescatore t & scandone p., (1973a): unità stratigrafico-strutturali e schema tettonico dell’appennino meridionale, ist. geol. geofis. università napoli, pubbl. 15, 1-33. lajoie j. and stix j., (1992): volcaniclastic rocks. in: r. g. walzer and n. p. james (eds), facies models: response to sea level change. geological association of canada, pp. 101-118. milia a.,(1996): evoluzione tettono-stratigrafica di un bacino peritirrenico: il golfo di napoli, tesi di dottorato, università degli studi di napoli federico ii. milia a., (1998): stratigrafia, strutture deformative e considerazioni sull’origine delle unità deposizionali oloceniche del golfo di pozzuoli (napoli), boll. soc. geol. it., 117, 777-787. milia a., (2000): active deformation and volcanism offshore campi flegrei, italy: new data from highresolution seismic reflection profiles, marine geology, 171, pp.61-73. milia a., torrente m.m., (2000): fold uplift and synkinematic stratal architectures in a region of active transtensional tectonics and volcanism, eastern tyrrhenian sea, gsa bulletin, 112, p 1531-1542. orsi g., de vita s., di vito m., (1996): the restless resurgent campi flegrei nested caldera (italy): constraints on its evolution and configuration, journal of vulcanology and geothermal research, 7744, 179-214. ortolani f., aprile f., (1978): nuovi dati sulla struttura profonda della piana campana a sud-est del fiume volturno, boll. soc. geol. it., 9988, 591-608. pescatore t.s., diplomatico g., senatore m.r., tramutoli m., & mirabile l., (1984): contributi allo studio del golfo di pozzuoli: aspetti stratigrafici e strutturali, mem. soc. geol. it., 2277, 133-149. pirazzoli p.a. (1976): sea-level variations in the northwest mediterranean during roman times, science, 119944, 519-521. rosi m. & sbrana a., (1987): phlegrean fields, c.n.r., quaderni de “la ricerca scientifica”, 111144--99, pp176. 21 ms. ricevuto il 15 maggio 2001 testo definitivo ricevuto il 23 aprile 2002 ms. received: may 15, 2001 final text received: april 23, 2002 stratigrafia e caratteristiche fisiche... amq 634 orombelli et al 36,1 5-37 corretto 120723.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 36 (1), 2023, 5-37 https://doi.org/10.26382/amq.2023.04 introduction to quaternary studies in italy: from arduino to the first half of the past century giuseppe orombelli1, maria rita palombo2,3, cesare ravazzi4,5 1 department of environmental and geological sciences, university of milano bicocca, milano, italy. 2 area della ricerca di roma 1, igag-cnr, montelibretti (rm), italy. 3 department of earth sciences, sapienza university of rome, roma, italy. 4 laboratory of palinology and palaeoecology, igag-cnr, milano, italy. 5 nbfc (national biodiversity future center), palermo, italy. corresponding author: cesare ravazzi <cesare.ravazzi@cnr.it> abstract: a summary of the origin and development of quaternary studies in italy since the 18th to mid 20th century is presented, focussing on marine sediment stratigraphy, continental glacial deposits, vertebrate palaeontology, palaeobotany, and palaeoanthropology. the history of the quaternary sciences in italy is also figured in a timeline of main milestones. the presence in italian quaternary deposits of cold-water atlantic immigrants, which currently inhabit boreal seas, was identified by brocchi in 1814. following the 18th international geological congress (igc) (1948), there was a surge in interest in these species, resulting in the identification of numerous boreal species (foraminifera, ostracods, bivalves, and gastropods). even in the second half of the twentieth century, considerable attention was paid to these "northern guests", their systematics, and taxonomic and biostratigraphic revisions, which contributed to defining the species that potentially have a chronological distribution and palaeoecological significance useful for defining pleistocene marine geochronological stages. the marine sediments, well exposed in southern italy, sicily and sardinia, had an important role in the development of quaternary stratigraphy since lyell in 1833 introduced the “newer pliocene”, later renamed pleistocene. several marine stages were defined in italy, sicilian by doderlein in 1872, calabrian by gignoux in 1910, tyrrhenian by issel in 1914, milazzian by deperet in 1918 and other later on. a scientific debate on the plio-pleistocene boundary began at the 18th international geological congress (igc) in london (1948) when it was established that it should be placed ”at the horizon of the first indication of climatic deterioration in the italian neogene succession” on the base of changes in marine faunas. the continental deposits, today attributed to the quaternary, were described and mapped as ’alluvial‘ and ’diluvial terrains‘ until the eighteen seventies. glacigenic deposits were identified and described in italy at the foot of the western alps by martins and gastaldi in 1850 and, in the following decade, at the foot of the central and eastern alps by de mortillet, omboni and others. in the last decades of the 19th century, taramelli, sacco, and cozzaglio, began to distinguish the evidence for more than one glaciation. since the publication of penck & brückner’s volumes in 1909, the four-glaciation scheme was generally adopted. the past presence of glaciers on the apuan alps and the apennines was first recognised in the latest 19th century. subsequently, over a hundred pleistocene glaciers had been identified and attributed to the würm glaciation. the palaeobotanical character of the quaternary was first recognised by reboul in 1833, as “characterized by animal and plant species similar to modern living ones at the same site”. latterly, brongniart, sternberg and balsamo-crivelli first classified plant macrofossils species, provided timelines and compared finds to the modern extant forms according to the linnean system. by the end of the 19th century, it became clear that the assemblage of extinct and eradicated plant species in northern italy gradually decreased through the pliocene, the quaternary interglacial and the postglacial periods (sordelli). the excavating peats at the onset of the 20th century suggested that the macrofossil record could be organised on a robust stratigraphical basis. in 1931-1932, the introduction of palynology in italy marked the initial development of microbotanical stratigraphy and its application to vegetation, climate history and interactions with prehistoric civilisations. since the renaissance, the remains of quaternary terrestrial mammals have attracted the attention of collectors and scholars when the collection of fossils from the upper valdarno was stimulated by ferdinando i de’ medici and andrea cesalpino reporting the finding of elephant bones at san giovanni valdarno. by the end of the 18th and beginning of the 19th centuries, several new species were identified from the mammalian remains primarily found in the tuscany basins. various geologists and naturalists contributed to the knowledge of the pleistocene deposits and their mammal fossil record in northern, central (e.g. in the roman basin), and southern italy, as well as in sicily and sardinia, from where a number of new endemic species were discovered. in 1865 pareto proposed the villafranchian stage for the sequence of fluvial and lacustrine sediments of villafranca d’asti (piedmont). the comparison of the mammalian fauna of villafranca with that of other late pliocene-early pleistocene faunal assemblages from italy, led successively to the definition of the ‘villafranchian european land mammal age‘. lastly, a brief outline of the beginnings of palaeoanthropological research and the noteworthy palaeolithic human remains discovered in italy until the first half of the 20th century is given. keywords: stratigraphy; glaciations; vertebrate palaeontology; palaeobotany; palaeoanthropology; history of science. 6 orombelli g. et al. 1. foreword italy possesses a rich and diverse variety of geological, palaeobiological and archaeological archives from the quaternary. the studies undertaken in italy have provided important contributions to the recognition of the peculiar characters of the quaternary, i.e the climate and the connected environmental changes that led to the glacial-interglacial cycles, the evolution of palaeoenvironments and mammalian communities, as well as the diffusion and settlements of prehistoric human populations in the country. here we summarise the first studies on marine sediments in relation to stratigraphy and palaeoclimatology, the continental deposits since the dawn of the ’glacial theory‘, and the fossil continental mammal faunas and plants. we also note the earliest research in palaeoethnology as well as the discovery of palaeolithic human remains. we focus on the period from the 18th century to the mid-20th century, before the revolution in quaternary stratigraphy and palaeoclimatology began by cesare emiliani (1955, fig. 1d, see section 2.3) with the isotopic studies of deep-sea cores, at the time of the iv inqua congress held in rome-pisa (1953) and the first international scientific journal entirely dedicated to quaternary, quaternaria, published in rome in 1954 by alberto c. blanc (fig. 1c). an introduction to quaternary studies in italy can ideally start with one of the fathers of the stratigraphy, the veronese giovanni arduino, “the man who invented the quaternary” (gibbard, 2019). in a letter addressed to antonio vallisnieri, professor of natural history at the university of padua, written in 1759 and published in venice in 1760, arduino (1) wrote: ‘as far as i observed up to now, the sequence of strata composing the visible bark of the earth seems to me to be distinct in four general and subsequent orders. the four orders may be considered as four huge strata …placed on top of each other …each of them made by countless other minor strata, composed of materials of many different types’. the four orders clearly show ‘to have been formed not only in different times but also under very different conditions’. ‘the first order, the deepest, and the second, following the first, form the great mountains, the third forms small mountains and hills, while the fourth forms the plains … also formed by beds over beds, by floods with deposition of materials carried down the mountains by waters of rivers and streams, reduced …to pebbles, gravel, sand and mud’. arduino (1760, fig. 1a) used the terms primary, secondary and tertiary as adjectives, respectively for the first, second and third order but he did not mention the term quaternary for the fourth order. probably since that time this word remained about to happen. the term quaternaire was first informally (“pour ainsi dire”) used by desnoyers (1829, p. 193) to designate the marine deposits “plus récens (sic) que les terrains tertiaires du bassin de la seine”, but he denounced usage of this word in a footnote on the same page. the name quaternaire was succesively applied by de serre (1830) and “finally defined on palaeontological grounds in 1833 by h. reboul” (head & gibbard, 2015). he wrote: “les monuments fossils des terrains tertiaries appartiennent presque tous à des espèces perdues. . . . c’estpourquoi on a dû appeller quaternaire la période subséquente, dont les terrains sont caractérisés par des espèces animals et végétales, semblables aux êtres actuellement vivans dans les mêmes lieux” (reboul, 1833). in the same period (1828-1829) charles lyell (fig. 1a) was visiting italy from piedmont to sicily “in order to acquire more information concerning the tertiary formations”, having “already conceived the idea of classing the different tertiary group, by reference to the proportional number of recent species found fossil in each” (lyell, 1833). he examined the collections of ”tertiary shells” collected by some italian palaeomalacologists (f.a. bonelli, g.b. guidotti, o.g. costa) in piedmont, the “subappennine” (parma) and southern italy in turin, parma and naples, and compared them with living species of the mediterranean. lyell himself examined many localities in southern italy (ischia, the flanks of mount etna and val di noto), collecting fossil shells. his investigations led him to conclude with “most lively surprise” that the majority of the fossil species collected “even at the height of 2000 feet above the level of the sea” were “species now inhabiting the mediterranean” (lyell, 1833). lyell, proposing a subdivision of “the great tertiary epoch” attributed the beds of ischia and val di noto to the fourth and youngest subdivision, named “newer pliocene”, that was renamed “pleistocene” a few years later (lyell, 1839, fig. 1a). the marine pleistocene of italy was later studied by many italian and foreign scientists, assuming great relevance for the quaternary stratigraphy. despite the arduino’s early hesitation, the term quaternary was introduced relatively late in italy. the continental deposits currently attributed to the quaternary, were, until the second half of the 19th century, generally named “terreni di trasporto antico e recente” or “alluvioni antiche e moderne” (ancient and recent transport/alluvial deposits) or with the latin names diluvium and alluvium, respectively. the term quaternary was used with differing meanings. among the first italian essays on stratigraphy, pilla (1845) distinguished, in the deposits above the ‘tertiary terrain’, from top downwards, the ‘recent (or modern) terrain’ and the ‘ancient alluvial terrain (diluvium and erratic boulders)’ the modern terrain was subdivided into lacustrine, marine and ‘quaternary terrain (emerged beaches)’. later pilla (1847-51) specified in a textbook that he defined ‘formation…. a rock or a union of strata produced in a narrow period of time’ and ‘terrain…. a union of for 1 the original sentences reproduced from previous authors are quoted in single quotation marks ‘…’, if literally translated from the italian, in double quotation marks “…“ in roman type, if in english, in italics if in other languages. 7 quaternary studies in italy from arduino to 1950’ mations showing features of chronological similarity’. he further stated that he included the ‘raised beaches or post-pliocene of lyell’ as quaternary terrain. pareto (1846b) named ‘quaternary … the most recent among the sedimentary terrains …to distinguish it from the subappenine tertiary formation’. in one of the first italian geology textbooks (elementi di geologia pratica e teorica), collegno (1847) incidentally mentioned that recently the ‘transport terraines have been named as quaternary terrains by a few modern geologists’. scarabelli (1852, fig. 1a) described the quaternary deposits (also called apennine diluvium) of the imola region, as a sequence of gravel, silt and sands with fossils of rhinoceros, other pachyderms and continental molluscs, unconformably overlying the marine pliocene. de la marmora (1857) devoted an entire chapter of his book (“voyage en sardaigne”, part 3: geological description) to the “terrains quaternaires”. he included in his “terrains quaternaires” the “grés quaternaire” (quaternary sandstone) with marine shells, unconformably overlying pliocene marls or on bedrock, the raised beaches, the bone breccia, the diluvium, the recent alluvial deposits, the barrier beaches. stoppani (1873), in his corso di geologia vol. 2 geologia stratigrafica proposed that the cenozoic era should be followed by the neozoic era (posttertiary or quaternary), in turn followed by the anthropozoic era. subsequently in a textbook on geology, curioni (1877) asserted: ‘many geologists subdivide the terrain that was formed after the new pliocene into three epochs, i.e: the epoch of the ancient alluvium, the epoch of the diluvium, the glacial epoch. this complex of deposits is said quaternary.’ the carta geologica della liguria marittima by pareto (1846a, fig. 1a), the carta geologica della provincia di bologna (scarabelli, 1853), the carta geologica della provincia di ravenna by scarabelli (1854, fig. 1a), the carte géologique de l’ile de sardaigne by de la marmora (1856), the lugano-como 1873 geologic map 1:100.000 by spreafico, negri and stoppani (1873), are among the first geological maps to adopt the term quaternary in italy (generally as a synonym for diluvium). however, the terms alluvium and diluvium (and equivalents) were still in use until the eighteen seventies on most maps. the term quaternary started to be used in the italian official geological maps since the first edition of the carta geologica d’italia at the scale 1:1,111,111 (1881) and of the first geological maps at the scale 1:100,000, published in rome (1884). on these maps, two stratigraphic units were distinguished above the pliocene: quaternario (quaternary) and recente (recent). beginning from the second edition of the carta geologica d’italia at the scale 1: 1,000,000 (1889), the quaternario has been subdivided into antico (“plistocene”) (sic) and recente. the quaternary, subdivided in pleistocene and holocene, appeared in the legend of the official geological maps of italy 1:100,000 since the 1920s. a comprehensive overview of the history of the cartographic production by the servizio geologico d’italia is presented by console et al. (2017). 2. the dawn of quaternary marine geochronology and chronostratigraphy in italy the mediterranean region, with its long, tectonically undisturbed, and well-exposed stratigraphic neogene sequences, has played a pivotal role in the development of quaternary stratigraphy since the beginning of geological research. in particular, along the coasts of southern italy and sicily, marine sediments have been uplifted by several tens of metres over the last three million years. the abundance of hemipelagic sediments favours deconstructing, for instance, the microfaunal and nannofloral evolution, the chronological assessment of species and the palaeoenvironmental development through time. 2.1. the “northern guest” immigrants in marine faunas the presence in italian quaternary deposits of cold -water atlantic immigrants, which currently inhabit boreal seas, was proposed by brocchi in 1814 on the basis of an erroneous attribution to "venus islandica" of some sinodia shells. it was later correctly reported for the first time by philippi (1834-1836), who identified some species of boreal molluscs in the quaternary deposits of sicily. following the 18th igc (1948), there was a surge in interest in these species, resulting in the identification of numerous boreal species in other groups (foraminifera, ostracods, bivalves and gastropods). even in the second half of the twentieth century, considerable attention was paid to these "northern guests", their systematics, and taxonomic and biostratigraphic revisions (e.g., malatesta & zarlenga, 1986; pasini & colalongo, 1997; faranda & gliozzi, 2011; gibbard & head, 2010, and references therein). this contributed to defining the species that potentially have a chronological distribution and palaeoecological significance which is valuable in defining pleistocene marine geochronological stages. 2.2. the marine stages proposed before the 1960s in the beginning, the proposal and definition of marine stages were primarily based on palaeontological criteria (particularly bivalves and gastropods, as well as corals, ostracods and benthic foraminifera), and later, particularly but not exclusively, on planktonic foraminifera and calcareous nannofossils. in recent years, palaeomagnetic evidence, absolute dating, and palaeoclimatic and proxy studies have all played an increasing role in marine chronostratigraphy and geochronology. the sicilian, the first stage to be proposed during the 19th century, is one of the best defined among the divisions. doderlein (1872) described the sicilian as a pliocene stage typified as “par le calcaire à coquilles tertiaires des environs de palerme, bagheria et de la baie de ficarazzi et par le mélange de calcaire pliocène et de laves qui constituent le sous-sol de la plaine de catane”. the palaeontological characteristics of the sicilian fossiliferous levels emphasised by doderlein (particularly the increase of "northern guests") correspond to those cited later by de sfefani (1891b) as typical of the level intermediate between the first and third of the three stratigraphic levels into which the italian palaeontologist divides his "post-pliocene." de stefani (1876), indeed, distinguished a post-lower pliocene, whose malacofauna still had affinities with the pliocene, and a post-middle pliocene characterised by an increase in "northern guests" and a decrease in survivors of the pliocene. in the post-upper pliocene, the latter characteristics became more pronounced, and modern species also proliferated. the well-known calabrian stage was introduced into the scientific literature by gignoux (1910), who considered that it was deposited after the pliocene. he designated the section of s. maria di catanzaro as the reference locality, where the base of the new stage was placed. gignoux (1913) observed: "au monte s. maria, le plateau culminant du point 207 est occupé par des marnes blanches qui recouvrent le banc à cyprina islandica" (recte arctica islandica). the french scholar also underlined that the deposition of such a level reflected a variation in the sedimentation accompanied by a change in the benthic community, while no discontinuities arising from flooding were present. therefore, he concluded that during the calabrian, a pre-existing clayey facies persisted, and this continuity of sedimentation related the early pliocene to the calabrian. as a result, according to gignoux (1910, 1913), the calabrian would correspond to the post-pliocene of de stefani (1891b), characterised by the appearance of molluscs of boreal origin (i.e., artica islandica) in the mediterranean sea. decades after gignoux's publications, micropalaeontological analyses at santa maria di catanzaro have demonstrated that, hyalinea baltica and globorotalia truncatulinoides excelsa were present in the same bed where a. islandica first appears (sprovieri et al., 1973; colalongo & pasini, 1980; colalongo et al., 1980, 1981, 1982). as a result, gignoux's ’calabrian‘ deposits are actually transgressive on the underlying pliocene marls, the latter referable to doderlein's (1872) sicilian stage, as are several sections described by the same author (e.g., caraffa, monasterace, palermo). subsequently, the chronostratigraphical significance and rank of the calabrian stage were reconsidered several times in the competition among the various pleistocene and pliocene sections exposed in southern italy (cita et al., 2008). this continued until its formal definition in 2012 as the second stage of the pleistocene series and quaternary system, following the gelasian (global boundary stratotype section and point, gssp, at vrica, calabria) (cita et al., 2012). furthermore, the evidence of a biostratigraphical correlation between the stratotype of this stage and the g-g level at santa maria di catanzaro, and thus the priority of the sicilian name over the calabrian, demonstrated that the subdivision of the lower pleistocene into calabrian and sicilian (gignoux, 1913) or into calabrian, emilian and sicilian (ruggieri & selli, 1950) (see below) can no longer be accepted. the tyrrhenian stage, recommended in 1914 by issel (fig. 1b), is one of the stage names, proposed at the beginning of the 20th century, that is still widely used in the scientific literature, albeit with different chronostratigraphical connotations. indeed, a formal definition of the tyrrhenian stage has never been proposed and indeed no potential subdivision of the upper pleistocene (following the formally defined middle pleistocene chibanian stage) has thus far been approved. the definition of stage/age and global stratotype section and point (gssp) of the upper pleistocene subseries/ subepoch is indeed still pending. issel (1914) based the establishment of the new tyrrhenian stage (originally called "tirreno") on the study of the rich marine fauna, characterised by the presence of ’tropical‘ taxa and those preferring warm waters, present in the coastal marine deposits of the stratigraphic succession still exposed at cala mosca (is mesas, capo sant'elia, gulf of cagliari). following issel (1914), all the deposits subsequent to the sicilian of doderlein and prior to the holocene (which at the time still remained poorly defined) could be referred to the tyrrhenian. accordingly, the "tirreno" in its original concept would include the entire upper pleistocene. the cala mosca levels were deposited during a high sea-level stand phase. consequently, the name tyrrhenian has generally been used to indicate marine deposits of the last interglacial. despite this, following issel (1914), the "tirreno" stage would cover a much longer time period, spanning from the warmest phase of the late pleistocene, documented by the presence of "strombus bubonius" (recte thetystrombus latus, fig. 1b), to the last glacial stage. later, bonifay & mars (1959) assigned the typical "strombus bubonius" faunal peak to their newly proposed chronostratigraphic subunit of the tyrrhenian, the eutyrrhenian, choosing the cala mosca beach deposit as the stratotype. coastal deposits at a height corresponding to the highest last interglacial sea-level stand would represent the eutyrrhenian subunit. this led to the correlation between the eutyrrhenian and marine isotopic substage 5.e. depéret proposed the milazzian stage in 1918, based on the rich mollusc fauna discovered in the pebbly sandy levels exposed along the western coast of capo milazzo (north-eastern sicily). in contrast to the other stages already mentioned, the milazzian was used mostly before the 1970s and has now generally fallen out of use. according to depéret (1918), the milazzian would have spanned a temperate time interval, with the corresponding level characterised by a banal malacofauna similar to that found today in the mediterranean. gignoux (1913) had already reported the presence of such a mollusc association that differs from the ’cold‘ one of the sicilian deposits and that of the tyrrhenian "strombus levels". a similar fauna was found at capo milazzo in marine terraced deposits which are located about 50-60 m above sea level (ruggieri & greco, 1965). this altitude is intermediate between the height of the sicilian deposits of gignoux (1913) (100 m) and that of the "tyrrhenian" levels with "strombus bubonius" and the senegalese molluscs of issel (1914). the milazzian stage, indeed, was not a well-founded division, 8 orombelli g. et al. during the second half of the 20th century to recent times, multidisciplinary studies of the well known italian long stratigraphical sequences led to the revision of already defined pleistocene marine stages, as well as to proposals of new divisions (cf. head, 2019), confirming the crucial role of italian deposits in the development of quaternary marine chronostratigraphy. 2.4. the first proposals for the plio-pleistocene boundary although being the first boundary to be examined by taking into account the stratotype concept, the question of the boundary between the pliocene and the pleistocene was not officially debated until many years after the pioneering research of the 19th century. the criteria for the definition of the plio-pleistocene boundary were first discussed in 1948, during the 18th igc in london. it was established that the boundary should be placed «at the horizon of the first indication of climatic deterioration in the italian neogene succession and should be based on changes in marine faunas». four years later, during the xix igc, alger 1952, the plio-pleistocene boundary was confirmed in the four italian stratigraphical sections exposed at monte mario, near rome (blanc et al.,1954), castell’arquato (piacenza) (di napoli alliata, 1954), santerno (imola) (ruggieri, 1954), and val musone (ancona) (selli, 1954). later, during vi igc (1961, warsaw, poland) and vii of the xix igcs (1965, denver, colorado, usa), it was decided that the boundary had to be placed in the le castella section (crotone-spartivento, calabria), at the base of the sandy level (g-g1) characterised by the first appearance (fad) of the benthic foraminiferan hyalinea baltica (emiliani et al., 1961). 3. continental quaternary deposits among the large variety of continental deposits, this chapter mainly concerns the glacigenic materials, since they have gradually assumed significant importance in the quaternary terrestrial stratigraphy of the country. 3.1. the advent of the glacial theory and the ice age as already mentioned, the continental deposits in italy today attributed to the quaternary, after arduino and for the most part of the 19th century, were described as alluvial and diluvial deposits. the latter were originally thought to have resulted from the noachian flood, and were later attributed to a variety of origins. in northern italy the large alluvial plain of the po valley drew the attention of the first geologists. breislak (1822) recognised that the plain, in the province of milan, was entirely composed of ‘alluvial or transport terrain’ at every depth where it could be observed. he just made a lithological distinction between pebbles and erratic boulders, gravels and sands, clays, calcareous tufa, peats, etc. moreover, he believed that the erratic boulders were transported by icebergs delivered by the alpine glaciers into the sea, an idea widespread at his time. venturi several scholars having questioned its validity. for example, ottman & picard (1954) noted that the presence of patella ferruginea and luria lurida in the milazzian deposits, which entered the mediterranean basin during the "tyrrhenian," suggests a more recent age (last interglacial) for the levels of the capo milazzo terrace, which was tectonically disturbed and uplifted, as already hypothesised by molino foti (1869). the attribution to mis 5e was made possible later by absolute dates on glycymeris sp. (amino acid racemization dating to c. 120 ka) and on a calcareous algae nodule (u-series dating: 83-100 ka) (belluomini, 1985; hearty et al., 1986). during the london igc (1948), ruggieri & selli (1949, 1950) introduced a new stage (emilian or calabrian ii/"hot upper calabrian"), chronologically interposed between the calabrian and the sicilian. studies of pliopleistocene sequences exposed in the emilia region revealed deposits of a warm-temperate fauna. both selli and ruggieri (ruggieri, 1954,1957; selli, 1967,1973) confirmed the original definition of the emilian, pointing out its climatic character and hypothesising a correlation with the ’gunz-mindel‘ interglacial. following the italian researchers, the emilian stratotype had to be defined in the santerno river valley where a long pliocenepleistocene marine sequence, characterized by the appearance progression of boreal species (a. islandica, h. baltica, and g. truncatulinoides excelsa), is well exposed between the villages of tossignano and imola (bologna). later, ruggieri et al. (1977) highlighted the presence of many temperate episodes in several pleistocene sequences in italy. such evidence suggests that the emilian cannot be distinguished by a single temperate climate criterion. accordingly, the new definition of the emilian stage was based on biostratigraphical criteria, i.e., h. baltica fad in the santerno section level, the site already proposed as the emilian stratotype. for an updated state of the art on global boundary stratotype and points (gssps) in the quaternary system, based on the stratigraphic record of italy, consult capraro & maiorano (2023, this volume). 2.3. the emergence of marine isotopic stratigraphy in the 1950s, the italian-american geologist cesare emiliani (fig. 1d) significantly advanced knowledge on marine stages by applying the urey's isotopical analytic method to calcareous foraminifers. he observed that in the shells the ratio between 18o and 16o (δ18o) periodically varied by about 0.2% and related such a variation to ocean temperature fluctuations. he correlated the palaeotemperature fluctuations deduced from isotopic data with glacial and interglacial phases (emiliani, 1955), introducing the numbering of the ’marine isotope stages‘ which is still used today, although with several refinements (see railsback et al., 2015, for further details). soon after, emiliani embarked on the study of isotope stratigraphy of marine section la castella in s-italy, which was committed for research on earliest cold spells in search for the plio-quaternary boundary (see section 2.4). emiliani's fundamental studies laid the groundwork for the development of marine isotope stratigraphy. 9 quaternary studies in italy from arduino to 1950’ 10 orombelli g. et al. (1817), the physicist known for the ’venturi effect’ in fluid dynamics, calculated the volume of a block of ice necessary to float, supporting the pedestal of the ’bronze horseman‘, the equestrian statue of peter the great in st. petersburg. the pedestal was made from a giant boulder of rapakivi granite, half embedded in a marshy ground near the city. venturi concluded that in the past the large glaciers of the alps could have produced ‘pieces of ice swimming on the sea’, with a volume sufficient to carry very large boulders. catullo (1838), describing the venetian provinces, made a distinction between ‘alluvial terrains (deposits even now forming in any part of the earth)’ and the ‘more extended and higher diluvial terrains (deposits that look like formed by the same waters responsible of the tertiary deposits)’. continuing this theme, curioni (1844), in a review on the geology of lombardy, mentioned ‘the erratic formation, scattered on the back of the mountains, largely accumulated on the hills and more widely on all the po plain’. the large boulders of alpine rocks, lying at a great distance from their origin in the high mountains, beyond deep lakes, aroused the most passionate investigations. at first it was imagined that they were carried here and there on an ancient ocean on floating ice. de buch and de beaumont thought they were dragged by the violence of enormous water currents, whilst the swiss geologists charpentier, venetz, agassiz recognised in them ‘the progressive motion, over vast regions, of glaciers pushing forward loose rocks and piling up them to form large dams or moraines’. collegno (1847) defined the ‘alluvial terrains’ as ‘deposits formed by present causes with the same energy of today’, while the ‘diluvial terrains were formed by the same presentday processes, but temporarily powered by a much higher and presently unknown strength. these anomalous deposits were also named erratic terrains, to mean materials transported by agents at present no longer active or too weak where now we can see them’. although collegno was aware of the glacial theory developed in the alps by jean-pierre perraudin, ignaz venetz and jean de charpentier in the first decades of the 19th century, and dramatically illustrated by agassiz in his volume études sur les glaciers (1840), he continued to support the idea that the erratic blocks were transported by ice rafts. in fact, although the glacial theory was rapidly accepted by buckland and lyell, many geologists remained unconvinced for many more years. as de mortillet (1861) mentioned, in the decade following the publication of the agassiz’s book, several italian and foreign students (leblanc, carrel, gal, guyot, forbes, coulomb, studer, zollikofer, martins, villa, catullo, parolini) observed and described erosional and depositional features on the southern side of the alps and on their foothills that they interpreted as the evidence of the past presence of glaciers. the first truly important paper, ‘that opened the study of glacial phenomena in italy’ (taramelli 1903) was that by martins and gastaldi (1850, fig. 1a) on the ”terrains superficiels de la vallèe du pô, aux environs de turin, comparés à ceux de la plaine suisse”. these authors fully accepted the ‘glacial theory‘, correctly recognising the geological evidence for the glacial erosion, transport and deposition. among the glacial-erosional forms they described are: polished and striated rocks with glacial striae and grooves (“roches polies, striées et cannellées”), different systems of striae indicating successive stages of glacier extent with different flow directions, “roches moutonnées” with asymmetric (stoss and lee) long profiles (indicating the direction and versus of glacier flow), striated pebbles and blocks (“cailloux rayés”). the accumulation forms and glacial deposits described include: terminal moraines (“moraines latérales, moraines frontales” ), ground moraine (“moraines profondes”) with hummocky topography, supraglacial and subglacial debris, lodgement and ablation till (“moraine superficielle”), aligned erratic blocks on the valley sides, together indicating the past glacier limit. in addition, martins & gastaldi (1850) recognized that the size of the lateral moraines was related to the height of ice-free valley slopes and to the size of the drainage basin, as well as the fact that the debris lithology was indicative of the rocks outcropping on the side of the valley. they first described the past presence of glaciers in the dora riparia and dora baltea basins, the ice having flowed along the susa and the aosta valleys, expanding and terminating on the po plain with two piedmont glaciers that formed, respectively, the terminal moraine systems (defined as morainic amphitheatres) of rivoli and ivrea. they clearly distinguisheded a sequence of almost circular concentric moraines separated by small lakes or peat bogs, that represent the maximum advance and the recessional stages of the glacier. the high terminal moraine of the dora baltea glacier, named la serra, was described as a ‘huge rampart with steep sides, particularly the inner one, projecting itself on the sky as a straight line lowering as it advances in the plain’. since then la serra has been considered one of the best preserved examples of a end moraine left by past glaciers in italy. martins & gastaldi (1850) also interpreted the alpine diluvium as glaciofluvial (outwash) deposits, describing their relatiosnship with the glacial deposits: ‘when a glacier advances, it builds new end moraines on the diluvium…. when it melts down and retreats it abandons on the diluvium ground and ablation moraines’. in the following years many studies were devoted to the glacial deposits in italy. for example, villa (1857) recognised that ‘all the hills branching out from erbusco towards calino and torbiato to iseo represent the various terminal moraines left by a large glacier descending by the mountains beyond lake iseo’, as described with further details and represented in a sketch-map by de mortillet (1859). latterly, omboni (1861a, fig. 1b) described and mapped the concentric semi-circular hills just south of lake orta and lake maggiore as ancient moraines and attributed them to ancient glaciers of the ticino and toce valleys. in a short note, at much the same time, paglia (1861, fig. 1b) recognised the elongated hills, with a triangular section, made of ‘erratic terrain’, and forming concentric semi-circular alignments south of lake gar da, as possible terminal moraines. he clearly mapped the more external arched moraine extending from calcinato to castenedolo from the group of younger moraines between castiglione dello stiviere and the oglio river. further to the east, where the tagliamento river flows from the carnic alps into the plain, pirona (1861, fig. 1b) described a sequence of concentric hills comprising ‘pebbles of various size, many of them striated, mixed with gravel, sand and clay, with any sign of lacustrine or fluvial stratification. at the surface of the hills, here and there large angular blocks made of various rock types are scattered’. he concluded that all these hills were terminal moraines produced by a huge ancient glacier that flowed from the carnic alps. de mortillet (1861) compiled a map of the ancient glaciers on the italian sides of the alps, shortly describing, from west to east, all the drainage basins that hosted large valley glaciers, many of them flowing into the plain and forming piedmont lobes. these last are documented by the morainic amphitheatres of rivoli, ivrea, those south of lakes orta, maggiore, lugano, como, iseo, garda, and those of piave and the tagliamento rivers. omboni (1861b), after a statement in favour of uniformitarianism (‘geologists have now adopted the method of studying the present phenomena to explain those happened in the past’), described the geological evidence left by glaciers in the present basins of the ticino, adda and oglio rivers, including the great lakes at the foot of the central alps. he paid particular attention to the lithology of the erratic blocks, reconstructing the provenance of the different valley glaciers. he distinguished the glacier of the toce basin, branching towards the present lake orta and lake maggiore valleys, the glacier of the ticino basin flowing along the lake maggiore and western lake lugano valleys, and the liro and mera basins glacier merging with the adda basin glacier and flowing with several interconnected branches along the valleys today occupied by the lakes lugano, como and lecco. all these glaciers reached the northern margin of the river po plain where, at the foot of the alps, where they formed a complex set of coalescent piedmont lobes. a sketch-map showing the geographical distribution of seven different groups of lithotypes present in the glacial deposits of lombardy was a first example of a study of provenance of the glacial sediments. in the second half of the 19th century, the studies on the ‘glacial period’ by abbot antonio stoppani (1867, 1873, 1880, fig. 1b) had particular influence in italy. in 1873, stoppani published the textbook on stratigraphy mentioned in the foreward and, few years later, a book on the ice age in italy (stoppani, 1880, l’era neozoica). he considered the ice age as one single glacial interval immediately following the deposition of the pliocene marine beds, when the pliocene sea was still present in the po valley at the foot of the alps. as depicted on the cover of the book, he imagined the alpine glaciers descending into fjords, where they released icebergs, while reindeer, bears, marmots and pachyderms inhabited the ice-free areas. this idea was based on the discovery (a few years earlier) of glacial deposits containing pliocene marine shells in the como and ivrea morainic amphitheatres. he interpreted these deposits as glaciomarine in origin. he considered (and figured in a map) the morainic amphitheatres south of the alps as directly deposited at the margin of the pliocene adriatic gulf of the mediterranean that covered the entire present po plain. this hypothesis was discussed and rejected by sordelli (1875), omboni (1877) and by gastaldi, taramelli and baretti who considered the fossil remains as reworked pliocene ‘warm’ water marine fauna. 3.2. glacial and interglacial periods during the last three decades of the 19th century new more detailed studies were undertaken on the glacigenic deposits of northern italy by taramelli, sacco, cozzaglio and stella. they initially recognised deposits of 2 3 discrete successive glaciations. taramelli (1870, 1875, 1881) mapped and described the glacial deposits of friuli, including the tagliamento piedmont glacier system, and in 1903 he published a geological map of the prealps and of lake maggiore, lake lugano and lake como morainic amphitheatres. these features occur between the ticino and adda rivers, where they represent three successive glaciations. in his map he distinguished: 1) post-glacial alluvial deposits, 2) fluvioglacial (recent diluvium) and glacial deposits of the last glaciation, 3) weathered fluvio-glacial and glacial deposits (middle diluvium locally glacial), deeply weathered fluvio-glacial and glacial deposits (ancient diluvium locally glacial), together indicative of three glaciations. subsequently, sacco mapped and described the morainic amphitheatres of rivoli, lake maggiore, lake como, lake iseo, lake garda and those of the veneto region, in a sequence of publications between 1886 and 1898. in these articles he failed to distinguishing moraines of the different glaciations but he did recognise three orders of terraces. shortly afterwards, cozzaglio (1891,1902) studied the morainic amphitheatres of lake garda and lake iseo. stella (1895) summarised the knowledge obtained by sacco, taramelli, cozzaglio and himself from the surveys made for the geological map of italy 1:100,000.they clearly distinguished between the postglacial fluvial deposits (alluvium) from the older quaternary deposits (diluvium) on the base of palaeontological and hydrographical-morphological characters. in turn, the diluvium was divided into three units (three terraces), the recent, the middle and the ancient diluvium. this was based on the basis of topography, morphology, weathering and stratigraphical relationships of the units. the recent diluvium forms the lower outwash terrace and is connected to the well-preserved moraines of the amphitheatres; the deeply weathered and rubefied ancient diluvium, forms the remnants of the highest terrace with a gently undulating surface and locally including glacial facies; the middle diluvium forms the remnants of the interposed, weathered terrace, and instead was interpreted as representing an interglacial accumulation. the short paper by penck et al. (1894, fig. 1b) “le system glaciaire des alps”, that anticipated the classic penck & brückner (1909) synthesis, led the way to new 11 quaternary studies in italy from arduino to 1950’ 12 orombelli g. et al. studies on the alpine glaciations also in italy. the article clearly described and figured the internal structure and surface appearance of the alpine glacial depositional systems, demonstrating the distinction between the glacial and fluvioglacial formations and their “relation intimes”. the main criteria to distinguish the deposits of successive glaciations were summarised as: the degree of surface weathering (including mention of the ferretto of lombardy, see below), the presence and number of loess/lehm strata and the morpho-stratigraphical relationships of the deposits (superposition versus emboîtement). on the basis of these criteria ‘it was necessary to admit that the three morphostratigraphic units (deckenschotter, hochterrassenschotter and niederterrassenschotter) and their moraines were indicative of three successive glaciations’. for the quaternary studies, the 20th century opened with die alpen im eiszeitalter, the three volume compendium by penck & brückner (1909) summarised their research lasting decades, that became the paradigm in glacial geology for the next 50 years. based on the morphological evidence in the alpine foothills, the authors described a glacial system composed of three major elements: a basin left by a glacier tongue, a belt of enclosing terminal moraines and an outwash fan and plain complex external to the moraines (fiebig & preusser, 2008). indeed, they recognised four stacked main outwash terraces, each connected to glacial deposits, attributed to four successive glaciations (termed günz, mindel, riss, würm), separated by interglacial periods during which the previous deposits were incised and weathered under warm/mild climatic conditions. the largest part of penck & brückner’s third volume is dedicated to the italian quaternary glacial deposits from the piedmont to the friuli-venezia giulia region. the largest morainic amphitheatres are described with the differentiation (in the sections and maps) of three main units: jungmoränen (w), altmoränen (r), ferrettomoränen (mf) and their related outwash terraces. in the ivrea morainic amphitheatre, a section across the large composite ’la serra’ moraine, shows the innermost part attributed to würm, the largest part to riss, while at the outmost border buried glacial deposits are attributed to the mindel. in the lake maggiore and lake como, würm, riss and ferretto/mindel amphitheatres moraines with their outwash terraces are clearly identified. the ferretto is the deeply weathered topmost part of the fluvioglacial and glacial deposits attributed to the mindel-age glaciation, developed during the (supposed) long mindel/riss interglacial. locally evidence of more ferretto surfaces of different ages were also observed. in contrast, in the garda amphitheatre only the most external moraine on the west side was attributed to the riss, and all the other moraines to the würm, while in sections along the bank of chiese river glacial and fluvioglacial deposits were assigned to the mindel and günz glaciations. the influence of penck & brückner’s work on the italian studies in the following decades remained substantial. on the official geological map 1:100,000, sheet ivrea, mapped by franchi, mattirolo, novarese and stella (1912) in 1890-1910, two glaciogenic units are distinguished in the ivrea morainic amphitheatre: 1würmian moraines, connected to the recent diluvium outwash terrace and 2weathered ancient moraines (prewürmian), connected to the weathered ancient diluvium outwash terraces (“ferretto”). on the aosta sheet, surveyed by mattirolo et al. (1912), the glacial deposits are indicated as würmian, post-würmian and recent moraines. sacco (1919) accepted the four glaciations scheme and in 1927 recognised three glaciations in the ivrea morainic amphitheatre, equating them to the last three of penck & brückner. likewise, cozzaglio (1933) adopted the four-fold glaciation scheme for the garda morainic amphitheatre, accepting the stratigraphical evidence for the günz glaciation along the chiese river, albeit attributing the most external moraine on the west side to the mindel while recognising an outer part attributed to the riss and an inner part attributed to the würm glaciation in the rest of the amphitheatre. glacial and glacio-lacustrine deposits attributed to the günz glaciation were reported by nangeroni (1929, 1950) and by riva (1942) in lombardy. haupt (1938) studied the glaciation in the bergamasque alps with a detailed map of the extent of the ice cover. a beautiful colour map of the extent of the last glaciation in the italian alps (and the northern apennines) was drawn by bruno castiglioni (1940). 3.3 the full acceptance of penck & brückner’s scheme, the milankovitch astronomical cycles and the emergence of multiple glaciations following the second world war a number of studies on the morainic amphitheatres was accomplished, based upon the penck & brückner scheme. nangeroni (1954a) described the glacigenic deposits south of lake maggiore, lake lugano and south-west of lake como, formed by the network of interconnected pleistocene glaciers descending from the toce, ticino and adda drainage basins. pracchi (1954) and nangeroni (1954b) described the glacial deposits that can be seen along the two branches of lake como, while riva (1957) mapped and described the morainic systems and outwash terraces south of lake como between the olona and adda rivers. finally vecchia (1954) described the lake iseo morainic amphitheatre. in a short summary of the five studies nangeroni (1954c) concluded that penck and brückner’s last three glaciations could be clearly distinguished on the basis of the morphology and surface weathering of three moraine systems and outwash terraces. evidence of the günz glaciation could only be found in deep sections, based on stratigraphiccriterial position. the maximum extent of glaciers decreased from mindel, to the riss and ultimately to the würm glaciations. on the slopes of the como and in the iseo glacial troughs three different moraine systems could be distinguished from top downwards: 1scattered erratics and residual moraine patches, locally deeply weathered; 2 terminal morainic ridges; 3 terminal ’morainic terraces‘. long profiles of major valley glaciers could be reconstructed for their ple glaciations of the pleistocene that were subsequently recognised in the deep-sea deposits and the loess sequences. 3.4. late-glacial and holocene glacier fluctuations by the end of the 19th century, attention was also payed to the geological evidence of late glacial and holocene glacier fluctuations within the great alpine valleys and near the front of the largest present-day glaciers. for example, novarese (1915, 1916) described evidence for the post-würmian stadials in the aosta valley. these intervals were named chambave, aymaville and courmayeur and correlated with the bühl, gschnitz and daun stadials identified by penck & brückner (1909). nangeroni (1930) described three stadial moraines in the val malenco (sondrio), reconstructing the relative glacier extents and snow-line altitudes, and their tentative correlation to the penck and brückner‘s stadials. a few other studies on late-glacial moraines were published in the following decades, generally of only local relevance. of particular significance are two studies by g.b. castiglioni (1961, 1964) on the lateglacial moraines of the mount adamello-presanella group and of the dolomites. following examination of the available study methods at the time (in the absence of numerical dating), the author concluded that three stadials could be identified in the two mountain areas. this was based on their average snow-line depression, compared to that at the beginning of the 20th century, which he correlated with the sciliar, gschnitz and daun stadials, the locally an innermost moraine being attributed to the egesen stadial. 3.5. the apennines beyond the alps the presence of quaternary glaciers on the apennine mountains was first suggested from the apuan alps (tuscany) by cocchi (1867, 1872b), stoppani (1872), and de stefani (1874), on the gran sasso (abruzzi) by berruti & st. robert (1871) and di s. robert (1884), on the northern apennines by de stefani (1887) and on the southern apennines by de lorenzo (1892, fig. 1b). these early reports were soon followed by more detailed descriptions by many other authors. northern apennines and the apuan alps sacco (1893) presented the first reconstruction of the glacier occurence along the northern sector of the apennines and on the apuan alps. because of the lower altitude with respect to the alps, they were mainly small glaciers on the north-facing side of the mountain chain, only a few valley glaciers reaching a length of few kilometres, as in val parma and in val cedra. sacco (1893) mapped the occurrence and the extent of glacial deposits from north-west (bobbio and s. stefano d’aveto) to south-east (mount cimone and corno alle scale), while de stefani (1891a) mapped a dozen ancient glaciers with the glacial cirques, as well as the extent of the glaciers and of their moraines on the apuan alps. many other studies followed in the first half of the 20th century, among which were those by losacco, who published a definitive memoir in 1949 and a revised maximum extent and elevation, and for the subsequent recessional stages. an extensive and original revision of the quaternary of the po plain is contained in gabert’s (1962) phd thesis: “les plaines occidentales du pô et leurs piedmonts piémont, lombardie occidentale et centrale”. this author studied the evolution of po plain and its margins from the miocene, from the tanaro to the adda river, and the pleistocene piedmont-glacier morainic systems from the dora riparia valley to the lecco lake. he recognised clear evidence of three major glacial advances which he equated to the mindel, riss and würm glaciations. he recognized that the würmian moraine systems are much better and extensively preserved than those of the rissian. he also demonstrated that the main level of the plain (i.e. the würmian outwash terrace) is linked to the last (würmian) morainic arches and that the equivalent plain extends almost uninterrupted from the stura di demonte to the adda river. furthermore, the pleistocene piedmont glaciers of the southern slope of the alps advanced much less over the plain than those north of the alps. finally the moraines of successive glaciations are closer together in italy rather than being more widely spaced as in bavaria: the würm moraines directly abutting those from the riss. from the late 1930s for more than three decades sergio venzo devoted himself to studying and mapping the quaternary continental deposits of northern italy. in particular are to be mentioned here his studies of the lacustrine sections of leffe (venzo, 1950, fig. 1c) and pianico (venzo, 1955) in the bergamo pre-alps, the geologic maps of the lecco (venzo, 1948) and of the garda morainic amphitheatres (venzo 1957, 1961, 1965) where he distinguished and mapped numerous groups of end moraines and related outwash terraces on the base of morphology and of the top soil sequences. he tried to correlate the succession of numerous palaeoclimatic changes recognized in lithology and pollen diagrams of the long lacustrine sections and in the stratigraphic, morphologic and soil/palaeosol evidence of the pleistocene glacigenic deposits at the foot of the italian alps with the insolation astronomical cycles calculated by milankovitch (1941). in the pre-mindel lacustrine sequence at leffe, venzo (1950) and lona (1950, fig. 1c) recognised five cold phases, that they correlated with three donau and two günz stadials, while in the lecco and garda amphitheatres venzo (1948, 1965) distinguished on the base of morphology and weathering of moraines and outwash terraces the evidence of three glaciations, each subdivided into two-three cold phases (stadials). the addition of three cold phases of the donau glaciation (eberl, 1930), as proposed by milankovitch (1941), ten minima of the insolation curve could be correlated with the fourfold penck & brückner (1909) scheme. this was deemed possible provided each glaciation was split into two-three cold phases, assumed to represent stadials. in the absence of independent time control, these correlations were hypothetical, but the suggested large number of cold phases anticipated the quasi-periodic multi 13 quaternary studies in italy from arduino to 1950’ 14 orombelli g. et al. edition in 1982. losacco (1949, 1982) carefully described and mapped the geological and morphological evidence (glacial cirques, glacial deposits and terminal moraines) of 59 glaciers present in thirteen mountain groups, from the ligurian to the tuscan-emilian apennines. all the glacial deposits were attributed to the würmian glaciation. for each palaeoglacier, the exposure, the maximum length, the maximum and minimum altitudes, and the snow-line altitude were reported. only about ten valley glaciers reached a length of 5 km and only one was 8 km long (parma valley), with a maximum thickness of 250 m. at least three recessional phases could be recognised in the majority of the mountain groups studied and recorded by nested terminal moraines in the highest parts of the valleys. by the third recessional phase the glaciers were almost all restricted to cirque tongues. losacco (1949, 1982) gave the altitude of the glacial deposits, of the snow-line and the snow-line rise with respect to the glacier maximum for each of the three phases. the reconstructed snow-line altitude (the average of the maximum elevation of enclosing mountains and lowest altitude of glacial deposits) during the maximum glacier extent raised from north-west to south-east from about 1300 m to 1600 m, while during the third recessional phase (correlated to the bühl stadial) was 250320 m higher. the low altitude of the late pleistocene snow-line on the northern apennines was attributed to high annual precipitation (in the first half of the 20th century this exceeded 2000 mm/yr). a synthetic view of the distribution of quaternary glaciers on the northern apennines and the apuan alps is published as a map by b. castiglioni (1940). central apennines following the first reports by berruti & st. robert (1871) and di s. robert (1884) on the past presence of glaciers on the gran sasso, many authors in the first half of the 20th century described the geomorphological and geological evidence of pleistocene glaciers on the mountain groups of the central apennines: hassert , sacco, almagià , crema, klebersberg on the abruzzi apennines, dainelli, franchi, biélerchatelan, sestini, beneo on the simbruiniernici mountains and klebersberg on the sibillini mountains. suter (1939) carried out systematic studies of the central apennines for a decade. he concluded (suter, 1940) that all the mountains higher than 2000 m were occupied by glaciers, as indicated by the presence of glacial cirques and moraines. he recorded over 200 cirques, mainly on the north and north-east-facing slopes. the floor of the cirques occurs at altitude of 1800-1900 m on the north-facing slopes, and 2200-2400 m on the south-facing slopes. a few u-shaped valleys are present, their floor reaching 150-300 m wide, with steep walls and trimlines marked by knickpoints. well preserved terminal moraines can be found on the high plateaux including campo imperatore, piano di ovindoli, piano aremogna etc. in a few valleys two or three recessional moraines may occur. suter (1940) considered that all the moraines were deposited during the last glaciation (würmian) and that older, more weathered moraines could not be observed. the size attained by glaciers on the gran sasso, mount, velino, mount greco and mount meta was 5 km or more (with a maximum of 10 km at campo imperatore), on the sibillini, simbruini, terminillo and majella mountains glaciers were 3.5 km long, while on the matese, mount morrone, sirente, mount cornacchia and mount d’ocre they were less than 3 km in length. these glaciers were 50-100 m thick, reaching a maximum of 200 m. the estimated snow-line altitude on the northern, eastern and western slopes was on average at 1750-1800 m, whilst on the southern slopes it stood at 2200-2300 m. two to three recessional phases were found and tentatively correlated on the base of the rising of the snow-line to the bühl and gschnitz stadials. within this latter stadial, glaciers disappeared from the apennines, except on the gran sasso and majella. based on the available knowledge, the distribution and the extent of glaciers from north to south, on the umbria-marche, lazio and abruzzo apennines, were represented on the 1:1,200,000 map ’the central apennines during the glacial period‘ compiled by sestini (1940). after the second world war, the evidence for prewürmian glacial deposits, hypothesised by suter (1940), was reported by demangeot (1963) from the gran sasso, and by pfeffer (1967) from the velino massif, both spreads being attributed to the riss glaciation. southern apennines few studies were devoted to the glacial features on the southern apennines before the second half of the 20th century. de lorenzo (1892) was the first to notice the evidence of an ancient glacier near lagonegro (basilicata). he described a terminal moraine in the mount sirino group, represented by ‘a great amount of mud chaotically including large and small blocks and pebbles of various size deriving from the surrounding calcareous and silicic rocks’. he saw many polished and striated pebbles in the moraine and rounded, polished and grooved rocks on the upstream flanks of the valley. with a sketch map and a section, he reconstructed the past valley glacier reaching about 3 km in length. two further ancient glaciers were recognised from their terminal moraines by de lorenzo (1893) in the same mountain group. the snowline altitude interpreted from the altitude of the glacial cirques was estimated at 1800 m. indications of the past presence of glaciers on the mount pollino (2248 m) massif, at the boundary between calabria and basilicata, were described by biasutti (1923) and klebersberg (1932). according to suter (1939, 1940) the average altitude of the snowline at the würmian maximum along the italian peninsula was at 1500-1600 m on the northern apennines, at 1350 m on the apuan alps, at 1750-1800 m on the central apennines, rising to 1900-2000 m on the southern apennines. according to trevisan (1940) the snowline rose from north to south with the increasing temperature along 5° of latitude, and from west to east as a consequence of decreasing precipitation from the tyrrhenian to the adriatic side. a map of the würmi an snowlines in the mediterranean, compiled by messerli (1967),shows their pattern along the italian peninsula, substantially corresponding to suter’s conclusions. 4. continental quaternary deposits: palaeontology and chronostratigraphy 4.1. palaeontological research from the late 18th century to the first half of the 20th century the earliest accounts of invertebrate and vertebrate fossil records date back to the renaissance period. regarding the continental domain, the remains of quaternary terrestrial mammals caught the attention of natural object collectors and scholars from various cultural backgrounds, and at much the same time the organic nature of fossils was first recognised (e.g., boccaccio, leonardo, colonna, and fracastoro) and that natural processes rather than the great flood were responsible for their accumulation (e.g., moro, volta, and beccari). two of the most notable examples are ferdinando i de' medici's rich medicea granducal collection of mammals from the upper valdarno (originally created in florence and then moved to pisa) (cfr. cioppi & dominici, 2010), and the report, at the end of the 16th century, of elephant bones (mammuthus meridionalis) at san giovanni valdarno by the pisan naturalist andrea cesalpino. later, francesco ii de' medici entrusted giovanni targioni tozzetti, a collector of natural objects, with the task of reorganising the collection's remains kept at pisa (targioni tozzetti, 1754). he not only played a crucial role in the analysis of the upper valdarno fossil mammal remains, highlighting their significance for comprehending the past flora and fauna life, but he also provided a thorough description of the deposits (some stratigraphical sections and lithologies) and their "natural products" (targioni tozzetti, 1752). however, palaeontological studies, in which geological, palaeontological, and sometimes archaeological aspects were often intimately connected, multiplied by the end of the 18th and during the 19th centuries. the multidisciplinarity of interests was a common trait of many of the first scholars (e.g., naturalists, geologists, physicians, and natural object collectors) who dealt with mammalian fossil remains. examples include, among others, bartolomeo gastaldi (1818-1879), interested in geology, glaciology, palaeontology, and palaethnology; francesco bassani (1853 -1916), geologist, palaeontologist, ichthyologist, seismologist, and volcanologist; and the engineer romolo meli (1852 -1921), whose scientific activity encompassed geology, palaeontology, malacology, and philology, as well as bibliographic studies. although there were several studies on pleistocene marine invertebrates, particularly molluscs such as those from the monte mario plio-pleistocene sequence (ponzi & meli, 1887; cerulli irelli, 1905, 1907-1916), the study of mammals received a huge boost after the publication of the fundamental writings of the zoologist, biologist, and naturalist george cuvier (1769-1832), considered the founder of vertebrate palaeontology (cuvier, 1812, 1821-1824, 1836). the french scholar was in contact with italian scientists, some of whom engaged him in the investigation of pleistocene animal remains from the italian peninsula and sardinia. for instance, positive discussions and exchanges with georges cuvier encouraged giovanni fabbroni (1752-1822), a chemist and naturalist who investigated the collections of mammals from upper valdarno, to become more interested in palaeontology (cioppi & dominici, 2010). during the 19th century, outstanding studies of the mammalian remains from the valdarno basini, as well as from other tuscany basins (see e.g., forsith major, 1877, 1881, 1890; ristori, 1897), led to the description and creation of new species still crucial for the systematics, biochronology, and evolutionary history studies of large eurasian pleistocene mammals. for instance, the naturalist and geologist filippo nesti (1780-1849) provided the first palaeontological description of proboscideans (mastodonts and elephants) from the upper valdarno basin (nesti, 1808). moreover, he created the well -known species ’elephas‘ meridionalis (recte mammuthus meridionalis) (the first elephant species to be reported in the eurasian early pleistocene), based on the rich elephant valdarno material he had discovered and described (nesti, 1825). later, weithofer (1893) carefully described the proboscideans remains from valdarno. when, in 1860, igino cocchi (1827-1913, fig. 1b) became curator of the palaeontological collections of the physic and natural history museum in florence, the study of valdarno mammals had a further stimulus. the scientist not only studied some specimens (e.g., the macaca remains, cocchi, 1872a) and created the new well-known species equus stenonis (cocchi, 1867), but also enriched the collections with several acquisitions, including skulls of the large sabretoothed cats megantereon cultridens and homotherium crenatidens, the latter genus erected by emilio fabrini (1890) for material from upper valdarno (cioppi & dominici 2010). fabrini (1890) and then domenico del campana (1915-1916) mentioned, under the name leopardus arvernensis, the other large felid from the early pleistocene of tuscany, panthera gombaszoegensis. del campana also studied the pleistocene canids from tuscany, revising the species already defined by fosyth major (1877), canis etruscus and canis falconeri (= xenocyon falconeri). the researcher created the species canis arnensis for the remains of a smaller dog from upper vardarno that he had found and described, and he also created a new running hyaena species, lycaena lunensis (recte chasmaporthetes lunensis), for the material from val di magra (del campana, 1914). the palaeontologist also studied the fossil record, mainly the avifauna, from apuane caves, including the rich mammalian material from the equi cave and tecchia (del campana, 1954). throughout the 19th and first half of the 20th centuries, several italian and foreign scholars undertook geo-palaeontological surveys and investigations in central italy, or they recorded and investigated recently discovered quaternary mammal remains (e.g., among others, battaglia, bleicher, ceselli, clerici, indes, lartet, napoli, neviani, rellini, terrigi, and verneuil). here, we 15 quaternary studies in italy from arduino to 1950’ would like to recognise the researchers that offered fascinating information on the pleistocene deposits and their mammal fossil record of the roman basin, including the rome metropolitan region, where vertebrate fossil remains were reported since the 16th century (e.g. mazzaella, de mancony, lancisi and calmet) and morozzo cited the discovery of an elephant fossil in the early 19th century (kotsakis & barisone, 2008). the biologist giuseppe ponzi (1805-1855), thought to have graduated in medicine, devoted himself to geological and palaeontological investigations. a consequence of his notable studies of the roman and tyrrhenian coast area cartography and geology, he has been considered the founder of the roman geological research school. as regards palaeontology, he revised the mammalian remains of some collections, studied new material, and discussed taxonomic and systematic issues in some cases. he compiled the first inventory of the roman mammalian associations, attempting to gather them into four chronologically homogeneous groups. he then proposed an assessment of their chronostratigraphic order, tentatively placing them from the miocenepliocene to the modern epoch (cf., among several others, ponzi, 1862a, 1862b, 1875, 1878, 1883). giuseppe augusto tuccimei (1851-1915), a physician, canon lawyer and naturalist, was a pioneer in geological and palaeontological research. in his studies of large and small plio-pleistocene mammals, he mostly described villafranchian species, not only reporting the remains found during field surveys and excavations, but also providing a systematic review of some taxonomic groups (tuccimei, 1889). romolo meli (see above) studied the geology, the stratigraphical assessment, and the palaeontological content of various plio-pleistocene latium deposits. his research activity was particularly devoted to the upper aniene valley, the roman campagna, and the rome metropolitan area, where he first recognized the significance of the pleistocene settlement of sedia del diavolo (meli, 1882). the naturalist alessandro portis (1853-1931), who had carried out significant geological surveys in northern and central italy since 1891, largely devoted himself to the study of the quaternary deposits of the campagna romana and their mammalian content (portis, 18931896), mostly describing the remains of elephants, carnivores, hippopotamuses, and large and medium-sized artiodactyls, also dealing with systematic issues (portis, 1920). he expanded time by time his research activity to other latium areas, such as the oricola-carsoli basin, where he found several bones of an elephant skeleton, showing in his opinion some similarities with both m. meridionalis and ‘elephas’ antiquus (recte palaeoloxodon antiquus) (portis, 1893-1896, volumes 1 and 2), to which the elephant was then referred by de angelis d'ossat (1956). enrico clerici, the engineer (1862-1938), geologist and naturalist, conducted several surveys and applied innovative methodological laboratory approaches to support his geological, palaeontological and mineralogical researches. together with relevant studies on quaternary invertebrates (mainly malacofauna, plants and diatoms), he studied mammal remains from most of the taxonomical groups, not only from a systematics point of view, but also considering their palaeoenvironmental context (e.g., clerici, 1888, 1932, and references therein). the versatility of the geologist gioacchino de angelis d'ossat (1865-1957) is demonstrated by the breadth of his study interests, which included palaeontology, philosophy and geology. his research activity was mainly focused on latium and the roman basin (for example, his study of the aniene upper valley). among his palaeontological studies, those related to the quaternary are mainly concerned with mammals. after his juvenile work on the woolly rhinoceros (de angelis d'ossat, 1895), he mostly studied proboscideans, especially p. antiquus. the study of elephants and the velia hill's deposits (via dei fori imperiali, rome) (de angelis d'ossat, 1897) is among the most well-known. it provides an extraordinary and detailed geo-palaeontological documentation of an area that is now completely urbanised. in the 19th century and until the 1960s, several geologists and palaeontologists (e.g., airaghi, anelli, cornalia, forsyth major, gastaldi, mariani, de stefano, de angelis d'ossat, portis, sacchi vialli, stoppani, zuffardi) dealt with north italian quaternary mammal remains. some of these fossil remains were retrieved from alluvial deposits of the main rivers; others were found in caves and occasionally in glacial deposits. the initial research activities carried out in the lignite deposits of the leffe basin are among the most relevant. since the first report by balsamo crivelli (1840, 1842), studies of the leffe large mammals (particularly elephants and rhinoceroses) by various researchers (e.g., airaghi, 1914; caffi, 1934; vialli, 1956) have highlighted their significance for the biochronology of the early pleistocene mammalian fauna from italy. regarding southern italy, a first inventory of mammalian remains was provided by flores (1895). various researchers reported mammal remains found in cave archaeological deposits (e.g., blanc g.a.,1920, 1928; botti, 1874,1890; graziosi & maviglia, 1946; mochi, 1911, rellini, 1920), while palaeontological and archaeological research of significance was carried out by de lorenzo and d'erasmo (e.g., de lorenzo & d'erasmo, 1927, 1932). giuseppe de lorenzo (1871-1951), geologist, palaethnologist and palaeontologist but also a botanist, philosopher and poet, boosted the development of geological studies in southern italy, especially in basilicata. however, he carried out research throughout italy, mainly dealing with volcanology but also with glaciology. his palaeontological studies mostly concerned the study of southern italy's straight-tusked elephants and their contemporaneity with the palaeolithic man. the pre-eminent research activity of the naturalist geremia d'erasmo (1887-1962) was related to fossil fishes, for which he became a well-known specialist. he also conducted extensive research on southern italian mammals, including hippopotamouses, and carefully 16 orombelli g. et al. studied fossil proboscideans, some of which he discovered in the sele and liri basins. he discussed the contemporary presence of palaeolithic man in those territories, as the numerous artifacts found both in the fossiliferous deposits and elsewhere document. in the first summary on elephants he published in collaboration with de lorenzo (de lorenzo & d'erasmo, 1927), d'erasmo discussed the belonging to p. antiquus of various remains of proboscideans and attributed some remains from abruzzi and lucania to m. meridionalis. in the 1950s, he discovered and described the skull of a young straight-tusked elephant from the well-known pignataro interamna site (montcharmont zei & d'erasmo, 1955). 4.2. the earliest studies of the endemic fauna of the two major islands, sicily and sardinia francesco anca and gaetano giorgio gemellaro were two of the most influential sicilian researchers. anca, an agronomist and zoologist, regarded as the father of sicilian palaeontology, was particularly active in the study of the quaternary mammals from sicily, notably those present in ossiferous breccias and cave deposits (e.g., anca, 1860). gemellaro, a physician and naturalist best known for his research on mesozoic invertebrates and squalodonts, also studied mammals found in pleistocene cave deposits (gemellaro, 1866). the collaboration of the two scholars led to the first attribution of fossil sicilian elephants to dwarf endemic species (anca & gemellaro, 1867).the dwarf elephants are the most significant and intriguing of the sicilian large mammal endemic species a result of the morphological and dimensional variety of their outstanding fossil record. cupani (1713) in the early 18th century was the first to mention, fossil elephant remains, i.e., a tooth (fig. 1a), but he did not recognise their actual nature. during the 19th century, various scholars described sicilian dwarf elephants, enhancing knowledge of their diversity (e.g., in chronological succession, scinà, anca, gemellaro, minà palumbo, dalla rosa, doderlein, stöhr, pohlig, de gregorio, etc.) (palombo et al., 2021 and references therein). these studies represented a substantial source for the seminal vaufrey's study of the mediterranean dwarf elephant taxonomy and evolution (vaufrey, 1929). the sardinian pleistocene vertebrate fauna has caught researchers' interest since the discovery of endemic mammalian remains in the early 19th century. the first surveys of quaternary deposits on the island and studies of their fossil content were carried out by the german anatomist and physiologist rudolf wagner (1805-1864, fig. 1a). he created the first sardinian endemic species, i.e. prolagus sardus, for the remains of a large lagomorph that are extremely abundant in the late pleistocene and holocene sardinia deposits (wagner, 1829). in the same period, general alberto la marmora, during his exploratory trip throughout sardinia, collected vertebrate fossils from various sites, including the ossiferous breccias of monreale-bonaria (cagliari). the mammalian remains found at the site were entrusted for study to the pisan physician cesare studiati (18211894), who in 1857 erected the new genus and the new species cynotherium sardous for some dental remains and an incomplete mandible of a small canid (studiati, 1857), with uncertain and debated phyletic relationships (cfr. zedda et al., 2022 and references therein). forsyth major was the primary researcher on the quaternary sardinian vertebrate fauna in the late 19th and early 20th centuries. he conducted new surveys and studied mammalian remains either recently discovered or from old collections. the scottish scientist created the species ’elephas lamarmorae’ (recte mammuthus lamarmorai), based on an almost complete skeleton from the funtana morimenta area (gonnesa) (the first discovered sardinian elephant) that acconci had already described in 1881 (forsyth major, 1883). in 1882, he also created the species ’arvicola’ henseli (recte microtus henseli) for a large arvicolid found in an unknown corsican locality and enhydrictis galictoides, based on a large endemic galictini remains found in the pleistocene deposits of monte s. giovanni (forsyth major, 1901). reinhold friedrich hensel, a german naturalist, described the remains of a shrew from the monreale bonaria breccias as sorex similis (= asoriculus similis) in the 1850s, as well as a new murid species, mus orthodon (= rhagamys orthodon), whose provenance from the same deposits is unknown. the french geologist and palaeontologist charles jean julien depéret carried out some research in the corso-sardinia massif and created in 1897 the wellknown species "cervus (eucladoceros)" cazioti (recte praemegaceros cazioti), a common component of the late plestocene sardinian fauna assemblages, based on a few antler and mandible fragments from the nonza cave (corsica) (depéret, 1897). at the beginning of the 20th century, emile george dehaut conducted some surveys and investigated the capo figari (olbia) breccia, finding several vertebrate remains. the french palaeontologist erected the species ’antilope melonii‘ (recte nesogoral meloni) for the skull of a small bovid partially embedded in a hard breccia matrix (dehaut, 1911). the peculiar characteristics of most of the capo figari remains hamper the possibility of firmly recognising the morphological traits of their continental ancestor. this is the case, for instance, of a large fragment of a small skull that dehaut ascribed to a primate, ’ophthalmomegas lamarmorae‘, while it belongs to a small endemic owl, bubo insularis. in the early pleistocene the capo figari promontory was actually inhabited by an endemic dwarf macaca, as documented by the find of a lower molar (dehaut, 1914) and especially by the material collected by forsith major during his systematic excavations. the italian palaeontologist augusto azzaroli (fig. 1d) studied a well preserved skull and created for the capo figari cercopithecide the new species macaca majori (azzaroli, 1946). since the second half of the 20th century, new studies and discoveries have notably enhanced our knowledge of the pleistocene insular mammalian fauna from sardinia and sicily (e.g., palombo 2018). 17 quaternary studies in italy from arduino to 1950’ mentary sequences would be deposited during glacial cycles. as a result, the researchers defined ’five glacial periods‘ (acquatraversan, cassian, flaminia, nomentanan and pontinian) that they correlated with five alpine glacial phases, from donau to würm (blanc, 1955, 1957, 1958; blanc et al.,1954,1955a,b). although the erosional phases actually correspond to sea-level lowering and low stand during glacial stadials, while the sedimentary successions have been mainly deposited during interglacial cycles, blanc's studies and its attempts to chronologically order the main stratigraphical roman basin events, offerred the basis for the future development of the continental deposit chronostratigraphy in the area. 5. fossil plants, the dawn of the quaternary and glaciation at the dawn of stratigraphy in the last decades of the 18th century, the linnean system of plant taxonomy was universally accepted by plant systematics (the 10th edition of systema naturae was published in 1758) and the botanical nomenclature (species plantarum, 1753) was used by the several botanists exploring the old world (linnaeus, 1753,1758). in the third decade of the 19th century, systematic palaeobotanists shared the concerns for a natural classification of fossil plants (brongniart, 1828), based not only on external and reproductive but also on anatomical characters (cuvier, 1821-1824). comparison of dispersed fossil plant parts with the whole-organism morphology of related modern living genera and species laid the foundation for comprehensive fossil floras and shed light on the relationships between fossil forms and the respective living taxa (sternberg, 1820-1828; brongniart, 1828-1838). plant diversity of tertiary strata mostly belonged to extinct species (unger, 1850), an evidence suggesting the need for a most recent geological period: “we claim for a subsequent period, i.e. the quaternary, which is characterized by animal and plant species similar to modern living ones at the same site” (reboul, 1833). however, at that time, comparing a fossil plant part with similar, yet described ones, was critical, due to shortages in material collection of either fossil or living taxa, and to poor assessments of world phytogeography. an example derives from juglans bergomensis described by balsamo crivelli (1840) (the tale was reviewed by martinetto et al., 2015). several decades later, sordelli (1873, 1878, 1896, fig. 1b) was able to specify the aliquot of tertiary species, presently extinct or eradicated from the alpine flora, which were still occurring at several macrofossil plant deposits from lombardy, clearly distinguishing the quaternary records from the marine pliocene leaf sites, and recognising three steps in the biochronological framework of plants in the alpine quaternary. an early step, considered to pre-date the diluvial and glacial events, was assigned to the villafranchian, intended as a biochronological unit pinpointing the transition at the end of the pliocene (pareto, 1865). the following intermediate step, rich in elements from the pontic flora, was found at the classical sites of piànico-sèllere, re in 4.3. note on the first attempt at a chronological assessment of quaternary continental sediments the study of continental plio-pleistocene strata and the fossils they contain has a long history in italy. in the renaissance, one of the earliest researchers to conclusively determine the organic nature of fossils was leonardo da vinci, far before ulisse aldrovandi invented the term ’geology‘ in 1603. in the leicester codex (1506-1510), he mentioned, for example, the ’njchi‘ (shells) of the arno deposits, whose alluvial origin he acknowledged, as well as of the piacenzian deposits of the parma and piacenza hills. he claimed that in the past, the sea had occupied the po valley (de lorenzo, 1920; ligabue, 1977). three centuries later, abbot antonio stoppani, geologist and palaeontologist, reiterated leonardo's assertion, but to contest the glacial theory. indeed, he affirmed that, in the quaternary, the adriatic occupied the entire po valley, penetrating into those valleys that would be occupied later by glaciers and then by lakes. however, the first continental stage was defined only in the second half of the nineteenth century when pareto (1865, fig. 1b) proposed the "piano villafranchiano", indicating villafranca d’asti as the type area, for a sequence of terrestrial sediments to fluvial and lacustrine present in the sedimentary basin of villafranca d'asti (piedemont). subsequently, gignoux (1916) proposed a correlation of this stage with his marine calabrian, at that time considered late pliocene in age (see above). the villafranchian definition is based on the palaeontological content, mainly mammals, of these strata. in this acceptance, for instance, the name was first used in the description of the central italy fossiliferous deposits by tuccimei (1889). the comparison of this mammalian fauna with other late pliocene-early pleistocene mammalian faunal assemblages from italy, i.e., those of the valdarno basin, which began in the 1970s, led to the definition of the villafranchian european land mammal age "elma" (azzaroli, 1970, 1972, 1977), still widely used as a eurasian biochronological unit. accordingly, the term ’villafranchiano‘ lost its original chronostratigraphical significance, although the name ’villafranchian succession‘ is still maintained for historical reasons only for the deposits of the villafranca d'asti basin. through the course of time, the stratigraphy of the villafranchian basin has been substantially revised (see e.g., carraro ed., 1996), even through multidisciplinary research (e.g., forno et al., 2015). in the first half of the 20th century, geologist alberto carlo blanc (1906-1960, fig. 1c), who had a keen interest in archaeology and palaeoanthropology, conducted important research on the quaternary deposits of lazio (e.g., agro pontino, circeo, and the tiber and aniene valleys). following the discovery of the second skull of saccopastore (rome, fig. 1c) he made with abbot breuil, (see below) (breuil & blanc, 1935a, 1935b), blanc and collaborators intensified the geological investigations of non-marine pleistocene sections in the roman area, then expanded to the torreinpietra site and surrounding area. these investigations led to the detection of major erosional phases, assuming that the sedi 18 orombelli g. et al. val vigezzo and the hötting breccia of innsbrück (baltzer, 1893; wettstein, 1892). the absence of farasiatic and pontic elements in the most recent ’postglacial flora‘ recorded from peat and calcareous tufa post-dating the glacial moraines of northern italy (villa, 1864, neuweiler, 1905; andersson, 1910) was related to a range contraction of temperate plants following the quaternary glaciation cold-climatic interval (sordelli, 1896). likewise, the many asiatic elements, typically recovered from the leffe record in the italian alps, disappeared sharply after the villafranchian, implying an early glacial event, corresponding to the multi-glacial theory promoted at the end of the 19th century (penck et al., 1894). ultimately, moving from the idea that observed changes between plant assemblages were not gradual through the course of the quaternary, but instead they were framed by multiple cold intervals, the concept of interglacial floral assemblages emerged (baltzer, 1893; sordelli, 1896). meanwhile, macrofossil plant sites raised another issue, which was to remain unsolved for many decades, i.e. the finds of temperate forest floras apparently present within glacial sequences (baltzer & fischer, 1890; sordelli, 1896). 5.1. the origin of terrestrial pollen stratigraphy in the quaternary of italy stratigraphical palynology originated as a tool to establish a time correlation between post-glacial peat sequences in sweden (von post, 1909, 1916; see manten, 1967 for a review). in the first decade of the 20th century, the palaeofloristic school of northern europe was addressed to recognise the succession of macrofossil assemblages recovered from post-glacial peat (andersson, 1898). neuweiler (1905) and andersson (1910) visited peat basins in northern italy, which were being excavated for fuel, and recognised an early post-glacial phase that included pine macrofossils, followed by oaks and warm-temperate aquatics, which were related to climate changes and to prehistoric dwellings. the concept that climate changes and human impacts could be interpreted from the stratigraphical study of apparently monotonous and short-lived peat sequences was perceived by the italian geologist taramelli (1910). this may be considered the foundation of the interdisciplinary high-resolution quaternary stratigraphy we know today. vegetation has the advantage that it integrates the climate over a number of years, and trees have a lifetime of decades (hay, 2013), comparable to a single human generation. despite these promising premises, the first pollen analyses in italy were delayed until 1929, when giuseppe dalla fior (fig. 1c) and paul keller independently addressed the study of peat sites at the southern foothills of the alps (keller, 1931, fig. 1c) and in the venezia tridentina (dalla fior, 1931, 1932, 1935). they disentangled the post-glacial forest history and found microbotanical evidence of prehistoric human impact on natural vegetation, i.e. at the pile dwelling of molina di ledro (dalla fior, 1940). the long debated pleistocene issues related to the succession of glaciations and their ecological impact were soon tackled by palynologists. the first pollen record of an alleged interglacial flora at civezzano (dalla fior, 1933) revealed the image of a temperate forest. later, the naturalist pietro zangheri carried out the first analysis of the glacial period in the subsurface of forlì, on the apennine side of the po plain, looking for the glacial and postglacial history of pines in relation to the origin of the pineta di ravenna (firbas & zangheri, 1935). dalla fior may henceforth be considered the founder of stratigraphical palynology in italy, his interests in palynology being stimulated by the phytogeographer giuseppe gola (ferrari, 1977). 5.2. after the second world war. pollen records of pleistocene plant diversity and climate change from lacustrine-palustrine records the potential of stratigraphical palynology to afford difficult problems in palaeoclimatology and pleistocene palaeoecology emerged soon after the identification of insolation astronomical cycles (milankovitch, 1941). as presented above (section 3.3), italian quaternary geologists encountered substantial difficulties correlating the classical penck & brückner (1909) four-fold scheme of glaciations with the minima of the insolation curve, given the complexity of mathematical climate solutions and the discontinuity of the glacial record. fausto lona (fig. 1c), a palaeobotanist, formed with dalla fior (lona, 1941) within the strong botanical group active in the thirty years at trento (tomasi, 2010), was recruited to the botanical institute in milano by the botanist sergio tonzig and, after the second world war, invited to investigate the pre-mindelian lake record at leffe by the geologist sergio venzo (fig. 1c). in the 1940s, the narrative about the vegetation history of early quaternary intervals was vague and its microbotanical diversity was unsuspected. however, the long lake record preserved in the leffe basin in the italian alps (fig. 1c) held a number of opportunities: (i) it had virtually continuous sedimentation, it represented over 70 metres of lacustrine sediments and brown coals (‘lignites‘) (venzo, 1950); (ii) it had good pollen preservation and (iii) it was situated close to the early glacial moraine systems (venzo, 1950), the oscillatiory behaviour of the glaciers indicated by which at the end of the villafranchian mammal unit (gignoux, 1943) was to be proved in the alps. hopefully, the pollen record by lona (1950) and lona & follieri (1957) illustrated a continuous sequence of ten phases of contraction of coniferous forests and timberline depression related to cold events, alternating with phases of mixed broad-leaved warm temperate forests, forming pollen assemblage cycles of varying amplitude. thus, the leffe sequence demonstrated, for the first time, the fine structure of the terrestrial climate history that characterises the european early pleistocene. these complex oscillations were believed to correlate with the early glacial phases of donau and günz and to span the entirety of the late villafranchian up to the early phases of the subsequent cromerian stage of western europe. this terrestrial correlation was presented in detail in a first terrestrial pleistocene teleconnection (zagwijn, 1957). a few years later, after completion of the microbotanical record (lona, 1962, 1963; lona & 19 quaternary studies in italy from arduino to 1950’ bertoldi, 1973), it was concluded that all the warm intervals were to be considered interglacial in character, thus tuning the record to the global climate cyclicity observed in the first available early pleistocene marine sediment isotope records (shackleton & opdyke, 1973, 1976, 1977). the research topic on pleistocene lacustrinepalustrine pollen stratigraphy was then expanded to explore the ecological history preserved in several intermontane basins and plio-pleistocene marine sequences in peninsular italy (lona & ricciardi, 1961; lona et al., 1969; lona & bertoldi, 1972, 1973). at the conclusion of the present contribution, it is worth mentioning the legacy of fausto lona in the formation of contemporary research groups of quaternary terrestrial palaeoecologists in italy. his scholars maria follieri (1956,1958a,b and foll.) and daria bertolani marchetti (1954, 1955, 1957 and foll.) established laboratories in which long-standing and productive activity in all branches of quaternary palaeobotany and archaeobotany flourished. moreover, in the 1950s, arturo paganelli (1956, 1958, 1959 and foll.) formed an important research centre at camerino, under the direction of vittorio marchesoni. 5.3. the early stages of archaeobotany and interaction with quaternary studies in italy the early history of studies on plant remains contained in deposits formed by human agency can be paralleled to the evidence offered by early archaeological excavations in the vesuvian area. already in 1740 carbonised plant remains found in herculaneum were recognised and exhibited (mariotti lippi et al., 2014). the first archaeobotanical report from pompei is dated to the third decade of the 19th century (covelli, 1827). by the first half of 19th century, the first comprehensive fossil floras were being published (see section 5). several plant records were analysed from settlements of roman age (de luca, 1863, 1879), but especially from waterlogged and hydromorphic deposits nearby to prehistoric wetland settlements, preserving very rich assemblages both in anthropic and in semi-natural plants. these studies enjoyed success after the discovery of lake-dwellings in the circumalpine region (keller, 1854), since heer (1865) demonstrated the importance of the investigations on these waterlogged plant remains (jacomet, 1998). a large array of pile dwellings and terramaras, being excavated for fuel or for manure in northern and central italy, yielded rich archaobotanical assemblages, readily identified and connected to human consumption and construction (strobel and pigorini, 1864; lioy, 1876; sordelli, 1880; scarabelli, 1887). although, several of these peat archives were soon destroyed and the fossil materials dispersed, even those sites still represent a reference for cultural biochronology today. the famous torbiera of lagoni di mercurago, first studied by gastaldi (1862) in connection with fuel exploitation, was depleted. likewise, after recent drillings (cnr-idpa, 2013), the deposit of the torbiera of polada, whose name is taken as a cultural reference for the early bronze age in the garda lake region (de marinis, 2000), turned out to have been exhausted by quarrying. by the beginning of the 20th century, archaeobotanical synthesis became available for italy (neuweiler, 1905). the archeobotanical biodiversity was also compared with diluvial, or “quaternary” floras, i.e. unaffected by human action (sordelli, 1878, 1896). at the end of 19th century, the archaeobotanical discipline was still seen as the study of human agency on plants in a ‘postquaternary’ context. for a review on further developments of palaeobotanical disciplines in italy in the last sixty years, consult paganelli and bertolani marchetti (1988) and mariotti lippi et al. (2014). 6. a brief account of the earliest palaethnological studies and the first reports of prehistoric human remains in italy 6.1. a look back at the beginnings of palaeoanthropological research in italy the ancient beginnings of the human species have been upheld since the classical epoch by philosophers, historians and poets, including plato, herodotus, diodorus siculus, strabo and lucretius, who also claimed that there was a time when humans did not know metals but instead worked rough stones. later, in the 16th century, the physician and naturalist michele mercati (15411593) reaffirmed this concept, claiming that ancient humans used lithic arms. in the classical epoch, illustrious people collected palaeolithic tools and fossil bones. for example, svetonius tells us that in the emperor augustus's villas there were bones of "gigantic beasts", prehistoric arms and stone hatchets collected by him on capri island. in the 18th century, some naturalists, theologians, archaeologists and historians, such as antonio vallisneri (1661-1730), giovanni antonio bianchi (1686-1768), and luigi antonio lanzi (1732-18109), mentioned prehistoric ’arrows‘. however, the scientific debate on the anthropogenic origin and age of lithic implements did not start until the early 19th century, promoted by the report by boucher de perthes, a geologist and antiquarian, of some lithic implements he had discovered and collected in the palo cave (rome) in 1810 and then in france in the somme basin. this event also encouraged the beginning of research activities and excavation campaigns. even in italy, the presence of prehistoric man (human remains and artifacts) was definitively confirmed in the 19th century by the activities of some scholars, such as luigi ricci (1823 1896) and his son corrado ricci (1858-1934), founder of the institute of archaeology and history of art, arsenio (1828-1900) and domenico crespellani, founders of modena archaeology, and stefano de stefani (1822-1892), who devoted himself mainly to survey and excavation campaigns such as those in the monte lessini territory. in the 19th century, however, the discovery and study of palaeolithic artifacts were mainly the research activity of geologists such as falconer, 20 orombelli g. et al. anca and gemellaro (see above), while palaethnologists focused on neolithic, often attributing to it even hand-axes and mousterian implements (except for those found in an indisputable stratigraphical context). the true nature and antiquity of palaeolithic artifacts were widely acknowledged in the early 20th century. gian alberto blanc (1879-1966), a physicist, geochemist and palaeontologist, and his son alberto carlo blanc (see above), provided a fundamental contribution to the development of italian palethnology through their fieldwork and studies. pioneering studies of the palaeolithic are attributed, for instance, to ippolito cafici (1857-1947), who was in contact with chierici, pigorini and strobel actively contributing to scientific debates; raffaello battaglia (1896-1958), who mainly carried out research in the fossiliferous caves of venezia giulia and discovered the valcamonica's graffiti and engravings; carlo maviglia (1897-1956), who carried out research throughout italy, from high altitude alpine sites, to lombardy, to basilicata (i.e., vulture basin), and to sicily(e.g., san teodoro cave, messina); luigi cardini (1898-1971), who carried out, for instance, notable research at balzi rossi and in the latium area; franco anelli (18991977), a palaeontologist and speleologist, who studied cave deposits in northern italy; paolo graziosi (1907-1988), the founder of the "rivista italiana di preistoria e protostoria", who focused attention especially to mousterian cave and upper palaeolithic deposits. this is to mention just a few among several other scientists. since the second half of the 20th century, research activities have become sensibly enhanced and the results of the studies of the palaeothnological record proven, taking advantage of new investigation methods and the support of other disciplines. 6.2. the most noteworthy palaeolithic human remains discovered from the 18th and the first half of the 20th century the palaeoanthropology of which édouard lartet (1801-1871), palaeontologist, geologist, and anthropologist is considered the founder substantially established itself as an autonomous science in 1856, when the remains (a skullcap and elements of the postcranial skeleton) of homo neanderthalensis were discovered in 1856 in the kleine feldhofer cave (neander valley, feldhof, germany). the first reports of pleistocene human remains discovered in italy (homo sapiens) date from the1790s, when emile rivière reported two child burials (1874) in one of the caves (grotta dei fanciulli, fig. 1b) of the balzi rossi site (liguria). other burials were discovered at the same site in 1884 by louis jullien at balma grande cave (an adult male skeleton covered by ocra), then in the same cave by giuseppe abbo in 1892 (three burials of an adult male and of young and adolescent females), and then in 1894 (two adult males). finally, in 1901, léonce de villeneuve discovered a single burial with the skeletons of an old and an adolescent female in the grotta dei fanciulli cave. the arene candide cave is another renowned site located on the north-western liguria coast with burials of anatomically modern humans. the arene candide cave necropolis has yielded numerous burials dating back to the terminal phases of the pleistocene (epigravettian). the cave was first discovered by issel in 1864, but the first excavation campaigns took place in the first half of the 20th century, carried out in the south-eastern sector of the cave by luigi cardini in 1940-42 and then, in 1948 -50, with luigi bernabò brea. the research revealed a long stratigraphical sequence, spanning from the upper palaeolithic to the byzantine epoch, and led to the discovery of several upper palaeolithic burials. among the nineteen burials, the most famous is that called ’giovane principe‘ because of the very rich equipment found in the burial. the skeleton, discovered in 1942, covered with red ochre, belongs to a fifteen year-old hunter, 1.70 m tall, with very strong arms, especially the right one that threw spears while hunting (cardini, 1942, 1980). the first remains of h. neanderthalensis had already been reported in 1929, when duke mario grazioli discovered the almost complete skull of a mature female in the gravel quarry at sacco pastore, on the left bank of the aniene river in a rural area, today within the city of rome. the discovery was communicated by sergio sergi who also studied the skull (sergi, 1929, 1944). a few years after the discovery of this skull (saccopastore i), the quarry was abandoned. during a geopalaeontological survey in the saccopastore cave in july 1935, alberto carlo blanc and abbot henri breuil found, the incomplete skull of an adult male (saccopastore 2, fig. 1c), lacking the entire vault, part of the base, and the left fronto-orbital areas (blanc, 1942, sergi, 1948). four years later, on february 25, 1939, alberto carlo blanc discovered a well-preserved third neanderthal skull (fig. 1c), belonging to a male approximately 40 -50 years old in the grotta guattari cave (circeo mountain) (blanc, 1942). the discovery had great resonance also for the peculiar positioning of the skull, found in the centre of the cave, surrounded by a ring of stones and for the presence at the base of the skull of a hole at the time interpreted as the result of an anthropogenic action aimed at removal of the brain, namely ritual cannibalism. this hypothesis was long and hotly debated until it was definitively clarified that the hole was created by a hyaena gnawing (white et al., 1991). from the second half of the 20th century onwards, new discoveries notably increased the italian fossil record of palaeolithic human remains, especially those not belonging to anatomical modern humans (amh). these are currently recorded from 37 sites, ranging in age from the early middle pleistocene (e.g., the femur diaphysis from notarchirico, vulture basin, dating to mis 16: i.e. cromerian complex stage) to mis 3 (i.e. mid-würmian) (e.g., the mandibular fragment from archi, calabria and the grotta breuil, circeo mountain, skull fragment). the variety of the fossil record suggests a new scenario for the evolutionary dynamics of the palaeolithic human population in italy. a state-of-the-art on pre-modern human fossils of italy is presented in buzi et al. (2021). 21 quaternary studies in italy from arduino to 1950’ 7. concluding remarks and perspectives in this short review, the authors have attempted to outline the main research lines pursued on the quaternary in italy, from the 18th to the mid-20th century, by scholars of natural history, geology, palaeontology and prehistoric archaeology. in general, they devoted themselves to many different research topics from the most various periods of the earth, with the partial exception of those who studied the traces of prehistoric man. the results of all these studies formed the foundations of a progressive specialisation along more clearly defined research lines in the years that followed, as well as a renewed interest in the past climate and environmental changes in comparison to climate change and the exponential increase of human impact. following the long tradition of biostratigraphical research on the marine neogene and pleistocene sequences in italy, the study of marine quaternary deposits made important contributions to the definition of the pliocene-pleistocene boundary and of the pleistocene stages/ages. the quaternary marine sections have been defined with increasing chronostratigraphical precision and detail as a result of multidisciplinary study and the gathering of new data. the stages previously proposed have been reconsidered, some redefined, and their rank reevaluated (capraro et al., 2022; capraro & maiorano, 2023). the gelasian and the calabrian (the first and the second stage of the pleistocene series, quaternary system) have both been formally ratified. after the first fundamental work of azzaroli (1977), which set the basis of the mammalofauna biochronology, various schemes have been proposed in attempt to order chronostratigraphically the continental terrestrial deposits according to their fossil mammal record. in the course of time, new discoveries and new data alter the schemes hitherto suggested, requiring revisions and new proposals (cf. e.g., palombo, 2021 and reference therein). as a result, the problem of defining a stable and shared chronological structure that could facilitate correlations between quaternary marine and continental deposits remains open. the study of the continental quaternary deposits in italy after the mid-1950s past century took advantage of the advances in sedimentology, geomorphology, neotectonics, soil sciences, glaciology, biostratigraphy, palynology, isotope stratiography, tephrostratigraphy, and of various methods of numerical dating to improve its peculiar stratigraphic and correlation criteria. the mounting evidence of multiple pleistocene climatic cycles, interpretred from the study of deep-sea sediment cores, long lacustrine pollen, and loess/ palaeosol successions, have led to the recognition of many more glaciations than the four of penck & brückner’s scheme (šibrava et al. 1986), while the ice-cores drilled in greenland and antarctica revealed the millennial scale climatic variability (johnsen et al., 1992; epica community members, 2006). for all these reasons the continental deposits of the plains and of the intermontane basins in italy could be studied and interpreted to decipher the complex events and the climate/ environmental changes at the different time scales (e.g. giaccio et al., 2019), as well as their neotectonics implications. the neotectonic map of italy (bosi, 1983, fig. 1d) represented the first comprehensive attempt to synthetize the most recent (plio-quaternary) geodynamics of italy; indeed, the entire territory turned out to have been affected by quaternary tectonic activity (galadini, 2004). new exciting discoveries of human remains, frequently associated with lithic and bone artifacts, have been made throughout the last fifty years from italian sites studied by geologists, palaeoanthropologists, palaeobotanists and palaeontologists. of note, for example, is the skull from ceprano, the skeleton from altamura, and the remains from isernia la pineta, cava pompi, visogliano, la polledrara di cecanibbio, and casal de’ pazzi, together with the 5000 years old ötzi mummy from the niederjoch glacier and the recently discovered nine neanderthal individuals from the guattari cave. in the last decades, a number of fine-resolution, multiproxy (biological, geoarchaeological and geobiochemical) records have disentangled the role of human activities in triggering the ecological history of the mediterranean and alpine quaternary, with a growing interest for the holocene and contemporary dynamics. these studies take their first insights from the multiproxy record of archaeological deposits. however, for a quantitative evaluation of interacting man, climate, and ecological processes it is compulsory to refer to off-site contexts with natural and biological sedimentation, the variety of which are offered by the diversity of mediterranean landscapes, including tree rings evidence. this has promoted several connected palaeoecologicalarchaeological research efforts, remarkably in inhabited lakes and mires (pile dwellings), coastal marine, lagoons, backswamp basins and marine caves nearby settlements (harbours, trade, fishing and ritual centres). thanks to this flexible long-to-short term and transdisciplinary quaternary concern it is now possible to compare past dynamics with contemporary changes, and to recognise baselines, thresholds and timelines of human impacts, in perspective to face an impending ecological transition. funding c.r. acknowledges funding by the project “national biodiversity future center nbfc”, code cn_00000033, funded by the european union nextgenerationeu -under the national recovery and resilience plan (nrrp), mission 4. component 2 investment 1.4 call for tender no. 3138 of 16 december 2021, rectified by decree n.3175 of 18 december 2021 of italian ministry of university and research. author contributions g.o. designed the overall structure of the paper and wrote section 3; m.r.p. wrote sections 2, 4 and 6; c.r. wrote section 5 and designed the timeline (fig. 1); 22 orombelli g. et al. all authors wrote the foreword and the conclusive remarks, and contributed to the selection of the timeline entries. acknowledgements we thank enrico rossi (muse museo delle scienze di trento, ufficio ricerca e collezioni museali, biblioteca "gino tomasi") for help with documentation on early palynologists and palaeobotanists in trentino (i.e. giuseppe dalla fior and fausto lona); stefano marabini (university of bologna) for information on the activity of giuseppe scarabelli; sergio bonomo (cnr-igag) and luca capraro (univ. of padova) for iconography of the gelasian paratype; ilaria mazzini and andrea sposato (cnr-igag) for mining the history of aiqua (italian association for quaternary studies). two anonymous reviewers provided significant hints to improve the quality of the paper. we are greatly indebted to philip gibbard (professor, scott polar research institute, university of cambridge), who carried out the english language correction and provided a qualified check over the identity of quaternary concepts developed through the italian narrative. we acknowledge the several institutions and scholars who provided images and documentation useful to build up the historical review of quaternary studies in italy included in the timeline of quaternary sciences in italy presented in figure 1. we thank renata perego (cnr-igag collaborator, archeobotanist) for skillful page layout editing of the “timeline”. credits and references for images to the timeline are included in its caption. 23 quaternary studies in italy from arduino to 1950’ > fig. 1 (a, b, c, d) a graphic timeline depicting the main steps in the studies of quaternary science in italy from the 18th to mid-20th century, with an abrigment of the milestones marking the last seventy years. some milestones have been provided by entries highlighted in bold. credits and references for images included in the figure: portraits of quaternary scientists lyell, de mortillet, cocchi, penck, brückner, du pasquer from wikipedia creative commons; martins from gallica.bnf.fr / bibliothèque nationale de france; sordelli, venzo courtesy of museo di storia naturale di milano; omboni, paglia, pirona courtesy phaidra università di padova; scarabelli courtesy stefano marabini; stoppani courtesy centro studi abate stoppani; arduino from library of the correo museum, venice; dalla fior photo by gino tomasi, courtesy muse museo delle scienze di trento. biblioteca; lona courtesy nota olfattiva, parma; issel courtesy società geologica d’italia geoitaliani.it; cita courtesy library digital collections | uc san diego library (cita) https://library.ucsd.edu/dc/object/bb3721209v. fossils, maps and drawings (1713) fossil molar of elephant (cupani, 1713). (1829) prolagus sardous (wikipedia). (1833) section valle di noto (lyell, 1833). (1846) geological map of the liguria marittima (pareto, 1846a). (1850) the serra d’ivrea glacial amphitheatre (martins & gastaldi, 1850). (1854) key of carta geologica di ravenna. (scarabelli, 1854). (1861) erratic block close to frascarolo, varese (omboni, 1861b). (1865) palate with molars of anancus arvernensis, villafranchian sequence of asti (wikipedia, courtesy museo palaeontologico territoriale dell’astigiano). (1872) reconstruction of the ancient glacier from valle del cacciatore, apennines (de lorenzo, 1892). (1874) burial of homo sapiens from grotta dei fanciulli, balzi rossi, liguria (catalogo generale dei beni culturali, mic ministero della cultura). (1894) succession of imbricated glacial-fluvioglacial complexes, a generalised section (penck et al., 1894). (1896) rhododendron ponticum fossil leaf from piànico-sèllere (sordelli, 1896). (1914) thetystrombus latus from issel’s collection found in cala mosca, sardinia, ex museo sardo di geologia e palaeontologia of the university of cagliari (romo mulas, 2018) . (1929) skull of homo neanderthalensis from the saccopastore cave, found by m. grazioli in 1929 (sergi, 1929) (human origins program, smithsonian institution). (1931-32) synthesis of postglacial pollen stratigraphy from the piedmont area (keller, 1931). (1939) (a) skull of homo neanderthalensis found in grotta guattari, s. felice circeo by alberto carlo blanc in 1939 (blanc, 1956). (b) position of skull (a) in grotta guattari (blanc, 1956). (1950) the middle part of the leffe lake stratigraphy, central alps (vialli, 1967). (1953) logo of the iv inqua congress, roma 1953 (restored and colored from https://www.inqua.org/) (1954) (a) cover of “quaternaria”, vol. 1, and (b) editorial board of “quaternaria”, vol. 1 (courtesy italo biddittu). (1956) cover of “origine e sviluppo dei popoli cacciatori e raccoglitori” (blanc, 1956). (1978) cover of “geografia fisica e dinamica quaternaria” first issue (courtesy gngfdq). (1983) cover of the neotectonic map of italy cased edition, published under the coordination of carlo bosi as a research package within a comprehensive project on geodynamics of italy (“progetto finalizzato geodinamica” promoted by the cnr) (bosi, 1983). (1988) (a) first logo of the italian association for quaternary studies (aiqua); (b) current aiqua logo; (c) cover of “il quaternario” first issue (courtesy aiqua). (1998) the "mandorlo" section described by capraro et al. (2022), a novel stratigraphic profile encompassing the upper piacenzian to lower calabrian interval in the western sector of monte san nicola (gela, sicily), where the global stratotype section and point (gssp) of the gelasian stage was defined (photo courtesy of sergio bonomo). fig. 1a (see caption in previous page) 24 orombelli g. et al. fig. 1b (continuation) 25 quaternary studies in italy from arduino to 1950’ fig. 1c (continuation) 26 orombelli g. et al. fig. 1d (continuation) 27 quaternary studies in italy from arduino to 1950’ references agassiz l. (1840) études sur les glaciers. neuchatel, jent et gasmann, pp. 345. airaghi c. (1914) l’elefante del bacino di leffe in val seriana (elephas meridionalis, nesti). atti società italiana scienze naturali, 52, 165-178. anca f. (1860) note sur deux nouvelles grottes ossiferères découvertes en sicile en 1859. bulletin de la société géologique de france, s.2, 17, 277-398. anca f., gemellaro g.g. (1867) monografia degli elefanti fossili della sicilia. tip. lorsnaider, palermo, pp. 23. andersson g. (1898) studier dfver finlands torfmossar och fossila kvartarflora. bullettin commission géologique finlande, 8. andersson g. (1910) beiträge zur kenntnis des spätquartären klimas norditaliens. die veränderuugen des klimas seit dem maximum der letzten eiszeit. ber. 11. intern, geol. kongr. stockholm, 1910, 79-95. arduino g. (1760) lettera seconda ad antonio vallisnieri di giovanni arduino veronese-vicentino sopra varie sue osservazioni fatte in diverse parti del territorio di vicenza, ed altrove, appartenenti alla teoria terrestre ed alla mineralogia. reproduced in: vaccari e. (2008) lettere di giovannio arduino (1714-1795) geologo. edizioni think adv, 173220. azzaroli a. (1946) la scimmia fossile della sardegna. rivista di scienze preistoriche, 1, 68-76. azzaroli a. (1970) villafranchian correlations based on large mammals. giornale di geologia, 35(1967), 111-131. azzaroli a., ambrosetti p. (1972) late villafranchian and esrly mid-pleistocene faunas in italy. in: geology and fauna of the lower and middle pleistocene of europe (ed. by nikiforova k.v., ivanova i.k., konstantinova n.a.). nauka publishing house, moscow, 40-71. [in russian] azzaroli a. (1977) the villafranchian stage in italy and the plio-pleistocene boundary. giornale di geologia, 41(2), 61-79. balsamo crivelli g. (1840) nota sul rinoceronte fossile esistente nell’i.r. gabinetto de’ minerali e fossili nel locale di s. teresa in milano; descrizione di alcuni denti di rinoceronte, e d’una nuova specie d’iuglandite trovati nelle ligniti di leffe. biblioteca italiana, 95, 1-6. balsamo crivelli g. (1842) memoria per servire all’illustrazione dei grandi mammiferi fossili esistenti nell’i. r. gabinetto di santa teresa in milano, e cenno sovra due mammiferi fossili trovato nella lignite di leffe nella provincia di bergamo. letto all’adunanza dell’i. r. istituto lombardo il giorno 19 agosto. giornale dell’istituto lombardo, 7, 1-23. baltzer a. (1893) glacialgeologisches von der sudseite der alpen (pianico-sellere). mittheilungen der naturfoschenden gesellschaft in bern, 1-10. baltzer a., fischer e. (1890) fossile pflanzen von comer-see. mittheilungen der naturfoschenden gesellschaft in bern, 139-145. belluomini g. (1985) risultati e prospettive di un nuovo metodo di datazione basato sulla racemizzazione degli aminoacidi. accademia nazionale dei lincei, contributi centro linceo interdisciplinare sc. mat. e loro applicazioni, 69, 135-171. berruti g., st-robert p. (1871) gita al gran sasso d’italia. torino, tip. bona, pp. 19. bertolani marchetti d. (1954) ricerche sulla vegetazione della valsesia. i: l'opera e le raccolte dell'abate carestia in valsesia. nuovo giornale botanico italiano, 61(4), 515-578. bertolani marchetti d. (1955) ricerche sulla vegetazione della valsesia. ii: la vegetazione della val sabbiola. nuovo giornale botanico italiano, 62(1-2), 283-334. bertolani marchetti d. (1957) les "prealpi bergamasche". in: guide itinéraire de la onzième excursion phytogéographyque internationale. alpes orientales, 1956. centro per lo studio della flora e della vegetazione italiana del c.n.r., pubbl. n. 109, 2638. biasutti r. (1923) sull'antico limite delle nevi nell'appennino centrale e meridionale. atti del 8° congresso geografico italiano, firenze, vol.2, 65-67. blanc a.c. (1942) i paleantropi di saccopastore e del circeo: i giacimenti. le industrie. correlazione geocronologica. quartär-internationales jahrbuch zur erforschung des eiszeitalters und der steinzeit, 4, 1-37. blanc a.c. (1955) ricerche sul quaternario laziale. iii. avifauna artica, crioturbazioni e testimonianze di soliflussi nel pleistocene medio-superiore di roma e di torre in pietra. il periodo glaciale nomentano, nel quadro della serie di glaciazioni riconosciute nel lazio. quaternaria, 2, 187-200. blanc a.c. (1956) origine e sviluppo dei popoli cacciatori e raccoglitori. edizioni dell’ateneo, roma. blanc a.c. (1957) on the pleistocene sequence of rome. palaeoecologic and archeologic correlations. quaternaria, 4, 95-109. blanc a.c. (1958) torre in pietra, saccopastore e monte circeo. la cronologia dei giacimenti e la palaeogeografia quaternaria del lazio. bollettino della società geografica italiana, 11, 196-214. blanc a.c., tongiorgi e., trevisan l. (1954) la limite plio-pléistocène dans la coupe de monte mario (environs de rome). congrès géologique international, comptes rendus de xix session, alger 1952. comptes rendus, 15, 218-228. blanc a.c., cova g., franceschi p., lona f., settepassi f. (1955a) ricerche sul quaternario laziale. ii. una torba glaciale, avifauna artica e malacofauna montana nel pleistocene medio-inferiore dell'agro cerite e di roma e il periodo glaciale flaminio. quaternaria, 2, 159-186. blanc a.c., lona f., settepassi f. (1955b) ricerche sul quaternario laziale. i. una torba ad abies, malacofauna montana e criosedimenti nel pleistocene inferiore di roma e il periodo glaciale cassio. quaternaria, 2, 151-158. blanc g.a. (1920) grotta romanelli. stratigrafia dei depositi e natura e origine di essi, archivio per l’antropologia e l’etnologia, 50, 364-535. blanc g.a. (1928) sulla presenza di alca impennis 28 orombelli g. et al. linn. nella formazione pleistocenica superiore di grotta romanelli in terra d’otranto. archivio per l’antropologia e l’etnologia, 58, 156-200. bonifay f., mars p. (1959) le tyrrhenien dans le cadre de la chronologie quaternaire méditerranéenne. bulletin société géologique de france, 7(1), 62-78. bosi c. (ed., 1983) neotectonic map of italy. scale 1:500.000: progetto finalizzato geodinamica. cnr, roma. botti u. (1874) sulla scoperta di ossa fossili in terra d’otranto. bollettino del regio comitato geologico, 1, 7-8. botti u. (1890) la grotta ossifera di cardamone in terra d’otranto (lecce). bollettino della società geologica italiana, 9(3), 3-30. breislak s. (1822) descrizione geologica della provincia di milano. milano, imperiale regia stamperia, pp. 260. breuil h., blanc a.c. (1935a) ritrovamento “in situ” di un nuovo cranio di “homo neanderthalensis” nel giacimento di saccopastore (roma). rendiconti della r. accademia nazionale dei lincei (cl. sci. fmn), 6(22), 166-169. breuil h., blanc a.c. (1935b) il nuovo cranio di homo neanderthalensis e la stratigrafia del giacimento di saccopastore (roma). bollettino della società geologica italiana, 54, 289-300. brocchi g.b. (1814) conchigliologia fossile subappennina. 2 vol. stamperia reale, milano. brongniart a.t. (1828-1838) histoire des végetaux fossiles ou recherches botaniques et géologiques. tome premier. paris, dufour et d’ocagne. pp. 288+11, tavv. 90 . buzi c., di vincenzo f., profico a., manzi g. (2021) the pre-modern human fossil record in italy from the middle to the late pleistocene: an updated reappraisal. alpine and mediterranean quaternary, 34(1), 17-32. caffi e. (1934) nuove osservazioni sul bacino di leffe in val gandino (provincia di bergamo). bollettino della società geologica italiana, 52(2), 341-345. capraro l., bonomo s., di stefano a., ferretti p., fornaciari e., galeotti s., incarbona a., macrì p., raffi i., sabatino n., speranza f., sprovieri m., di stefano e., sprovieri r., rio d. (2022) the monte san nicola section (sicily) revisited: a potential unitstratotype of the gelasian stage. quaternary science reviews 278, 107367. capraro l., maiorano p. (2023) italian gssps of the quaternary system. alpine and mediterranean quaternary, 36(1), 1-23. cardini l. (1942) nuovi documenti sull’antichità dell’uomo in italia: reperto umano del palaeolitico superiore della grotta delle arene candide. razza e civiltà, 3, 5-25. cardini l. (1980) la necropoli mesolitica delle arene candide. memorie dell’istituto italiano di palaeontologia umana, 3, 9-31. carraro f. (ed., 1996) revisione del villafranchiano nell'area-tipo di villafranca d'asti. atti del convegno: "il significato del villafranchiano nella stratigrafia del plio-pleistocene" (peveragno (cn) villafranca d'asti, 20-24 giugno 1994). il quaternario. italian journal of quaternary sciences, 9(1), 38-62. castiglioni b. (1940) l’italia nell’età quaternaria, carta delle alpi nel glaciale 1:200,000. in: dainelli g., ed., atlante fisico-economico d’italia, consociazione turistica italiana, milano. castiglioni g.b. (1961) i depositi morenici del gruppo adamello-presanella con particolare riguardo agli stadi glaciali postwurmiani. memorie degli istituti di geologia e mineralogia dell’università di padova, 22, 1-131. castiglioni g.b. (1964) sul morenico stadiale nelle dolomiti. memorie degli istituti di geologia e mineralogia dell’università di padova, 24, 3-16. catullo t.a. (1838) trattato sopra la costituzione geognostica-fisica dei terreni alluviali o postdiluviani delle provincie venete. tip. cartallier e sicca, padova, pp. 512. cerulli irelli s. (1905) sopra i molluschi fossili del monte mario presso roma. bollettino della società geologica italiana, 24, 191-194. cerulli irelli s. (1907-1916) fauna malacologica mariana. palaeontographia italica, 13 (1907), 65-139; 14 (1908), 1-63; 15 (1909), 125-213; 16 (1910), 2370; 17 (1911), 229-275; 18 (1912), 141-169; 20 (1914), 183-277; 22 (1916), 171-219. cioppi e., dominici s. (2010) origin and development of the geological and palaeontological collections. in: il museo di storia naturale dell’università di firenze. volume 3°. le collezioni geologiche e palaeontologiche (ed. by monechi s., rook l.), 19 -55. cita m.b., capraro l., ciaranfi n., di stefano e., lirer f., maiorano p., marino m., raffi i., sprovieri r., stefanelli s., rio d., vai g.b. (2008) the calabrian stage redefined. episodes journal of international geoscience, 31(4), 408-419. cita m.b., gibbard p.l., head m.j. (2012) formal ratification of the gssp for the base of the calabrian stage (second stage of the pleistocene series, quaternary system). episodes, journal of international geoscience, 35(3), 388-397. clerici e. (1888) sopra alcune specie di felini della caverna al monte delle gioie presso roma. bollettino del regio comitato geologico d’italia, 5, 149167. clerici e. (1932) la geologia e la palaeontologia in roma e nel lazio. in “le scienze fisiche e biologiche in roma e nel lazio”, istituto di studi romani, roma. reprint, pp. 33. cnr-idpa (2013) indagine stratigrafica sui depositi del bacino della polada (comune di lonato del garda) con particolare riguardo ai depositi olocenici. unpublished technical report, may 6, 2013, pp. 50. cocchi i. (1867) l’uomo fossile nell’italia centrale. memorie della società italiana di scienze naturali, 2 (7), 3-80. cocchi i. (1872a) su di due scimmie fossili italiane. bollettino del r. comitato geologico d'italia, 3(34), 59-71. cocchi i. (1872b) del terreno glaciale delle alpi apuane. bollettino del r. comitato geologico d'italia, 3 29 quaternary studies in italy from arduino to 1950’ (7-8), 187-197. colalongo m.l., pasini g. (1980) la ostracofauna pliopleistocenica della sezione vrica in calabria (con considerazioni sul limite neogene/quaternario). bollettino della società palaeontologica italiana, 19, 44-126. colalongo m.l., pasini g., sartoni s. (1980) remarks on the neogene/quaternary boundary and the vrica section. preprint 26th int. geol. congr., paris, 1-40. colalongo m.l., pasini g., sartoni s. (1981). remarks on the neogene/quaternary boundary and the vrica section (calabria, italy). bollettino della società palaeontologica italiana, 20, 99-120. colalongo m.l., ricci lucchi f., guarnieri p., mancini e. (1982) il plio-pleistocene del santerno (appennino romagnolo). guida alla geologia del margine appenninico padano: guide geologiche regionali della societa geologica italiana, bologna, 161-166. collegno g. (1847) elementi di geologia pratica e teorica. torino, g. pomba e comp. editori, pp. 462. console f., pantaloni m., tacchia d. (eds., 2017) la cartografia del servizio geologico d'italia. memorie descrittive della carta geologica d'italia. ispra servizio geologico d'italia, roma. covelli, n. (1827) rapporto su le olive e sulla sostanza butirrosa trovate in pompei il dì 4 di agosto del 1826. museo borbonico iii, napoli. 6-8. cozzaglio a. (1891) osservazioni geologiche sulla riviera bresciana del lago di garda. bollettino della società geologica italiana, 10, 247-308. cozzaglio a. (1902) studi di geologia continentale sui laghi di garda e d’iseo. apollonio, brescia, pp. 45. cozzaglio a. (1933) note illustrative della carta geologica delle tre venezie, fogli peschiera e mantova. ministero dei lavori pubblici ufficio idrografico del r. magistrato alle acque, pp. 130. cupani f. (1713) panphyton siculum sive historia naturalis de animalibus stirpibus, fossilibus, quae in sicilia, vei. in: circuito fjus inveniuntur. typographia regia antonino epiro, palermo. biblioteca centrale della regione, palermo. curioni g. (1844) capo ii stato geologico. in: notizie naturali e civili sulla lombardia. vol. i (cattaneo c.). tip. g. bernardoni di giovanni, milano, 27-88. curioni g. (1877) geologia parte prima geologia applicata delle provincie lombarde. ulrico hoepli libraio-editore, milano, pp. 418. cuvier g. (1812) recherches sur les ossemens fossiles, où l’on rétablit les caractères de plusieurs animaux dont les révolutions du globe ont détruit les especes. atlas 1-2. deterville, paris. cuvier g. (1821-1824) recherches sur les ossemens fossiles, ou l’on rétablit les caractères de plusieurs animaux dont les révolutions du globe ont détruit les espèces. five volumes. dufour et d’ocagne, paris. cuvier g. (1836) recherches sur les ossements fossiles. tome ix, dufour et d’ocagne, paris. dalla fior g. (1931) sui primi risultati ottenuti nell’analisi dei pollini fossili di due torbiere trentine. nuovo giornale botanico italiano, 38, 361-362. dalla fior g. (1932) analisi polliniche di torbe e depositi lacustri della venezia tridentina. memorie del museo di storia naturale della venezia tridentina, 13(4), 139-165. dalla fior g. (1933) analisi polliniche di torbe e depositi lacustri della venezia tridentina; ii, torbe del renon. memorie del museo di storia naturale della venezia tridentina, 1, 235-249. dalla fior g. (1935) analisi polliniche di torbe e depositi lacustri della venezia tridentina; iv, depositi torbosi dellalto isarco e del bacino idrografico della rienza. memorie del museo di storia naturale della venezia tridentina, 3, 65-85. dalla fior g. (1940) la palafitta di molina di ledro. memorie del museo di storia naturale della venezia tridentina, 5(1), 97-148. de angelis d'ossat g. (1895) il rhinoceros (coelodonta) etruscus falc. nella provincia romana. atti della accademia gioenia di scienze naturali di catania, ser. 4, 9, pp. 9 (reprint). de angelis d'ossat g. (1897) l'alta valle dell'aniene. memorie della società geografica italiana 7, 191267. de angelis d'ossat g. (1956) geologia del colle palatino in roma. memorie descrittive della carta geologica d’italia 32, 5-95 de la marmora a. (1856) carte géologique de l’isle de sardaigne. cromolith. giordana, grand didier et salussola, turin. de la marmora a. (1857) voyage en sardaigne. troisème partie. description géologique. turin, paris, pp. 706. de lorenzo g. (1892) avanzi morenici di un antico ghiacciaio del monte sirino nei dintorni di lagonegro (basilicata). rendiconti della reale accademia dei lincei, classe di scienze fisiche, matematiche e naturali, ser.5, 1, 348-353. de lorenzo g. (1893) il postpliocene morenico nel gruppo montuoso del sirino in basilicata", rendiconti della reale accademia dei lincei, classe di scienze fisiche, matematiche e naturali, ser.5, 2, 317-320. de lorenzo g. (1920) leonardo da vinci e la geologia. zanichelli, bologna, pp. 200. de lorenzo g., d'erasmo g. (1927) l'elephas antiquus nell'italia meridionale. atti della reale accademia delle scienze fisiche e matematiche di napoli, 2, 13(5), 1-104. de lorenzo g., d’erasmo g. (1932) l’uomo palaeolitico e l’elephas antiquus nell’italia meridionale. atti reale accademia di scienze fisiche e matematiche di napoli, 19 (5), 1-106. de luca s. (1863) ricerche chimiche sul pane e sul grano rinvenuti negli scavi di pompei. rendiconto dell’accademia delle scienze fisiche e matematiche (napoli), 2, 172-179. de luca s. (1879) ricerche analitiche sull’olio trovato negli scavi fatti a pompei. rendiconto dell’accademia delle scienze fisiche e matematiche (napoli), 18, 219-221. de marinis r. (2000) il museo civico archeologico giovanni rambotti una introduzione alla preistoria 30 orombelli g. et al. del lago di garda. città di desenzano del garda. assessorato alla cultura. de mortillet g. (1859) note géologique sur palazzolo et le lac d’iseo en lombardie. bulletin de la société géologique de france, 16, serie 2°, 888905. de mortillet g. (1861) carte des anciens glaciers du versant italien des alpes. atti della società italiana di scienze naturali, 3, 44-81. de serres m. (1830) de la simultanéité des terrains de sediment supérieur. géographie-physique de l’encyclopédie méthodique, 5, pp. 124. de stefani c. (1874), gli antichi ghiacciai dell'alpe di corfino ed altri dell'appennino settentrionale e delle alpi apuane. bollettino del r. comitato geologico d’italia, 5(3-4), 86-94. de stefani c. (1876) sedimenti sottomarini dell’epoca post-pliocenica in italia. bollettino del r. comitato geologica d’italia, 7, 272-289. de stefani c. (1887) i depositi glaciali dell'appennino di reggio e di modena. atti della società toscana di scienze naturali, 5, 206-211. de stefani c. (1891a) gli antichi ghiacciai delle alpi apuane. bollettino del club alpino italiano, 24(57), 174-202. de stefani c. (1891b) les terrains tertiaires supérieurs du bassin de la méditerranée. ann.ales de la société géologique de belgique, 35, 63-98. dehaut e.g. (1911) animaux fossiles du cap figari. matériaux pour servir à l’histoire zoologique et paléontologique des iles de corse et de sardaigne, 3, 53-59. dehaut e.g. (1914) nouvelles recherches sur les mammiferes pléistocénes et récemment éteint de la sardaigne. i partie: ordre des singes. materiaux pour servir à l’historire zoologique et paléontologique des iles de corse et de sardaigne, 5, 71 -85. del campana d. (1914) la lycaena lunensis n.sp. dell’ossario di olivola (val di magra). palaeontographia italica, 20, 87-104. del campana d. (1915-1916) nuove ricerche sui felini del pliocene italiano. palaeontographia italica, 22, 1-33. del campana d. (1954) carnivori quaternari della tecchia e caverna di equi nelle alpi apuane. palaeontographia italica, 44, 4-21. demangeot j. (1963) le glacier rissien de pietracamela (apennin abruzzais). méditerranée, 4(1), 83-92. dépéret c. (1897) etude de quelques gisements nouveaux de vertébrés pléistocènes de l’île de corse. annales de la société linnéenne du lyon, 44(1), 111-128. dépéret c. (1918) essai de coordination chronologique des temps quaternaires. comptes rendus de l’academie des sciences, paris, 166 (12), 480-486. desnoyer j. (1829) observations sur un ensemble de depôts marins plus récens que les terrains tertiaries du basin de la seine, et constituent une formation géologique distincte; précédées d’un aperçu de la non simultanéité des bassins tertiaries. annales des sciences naturelles (paris), 16, 171214, 402-491. di napoli alliata e. (1954) la limite plio-pleistocène dans la coupe de castell’arquato (plaisance). congrès géologique international, comptes rendus de xix session, alger, 1952. comptes rendus, 15, 229-234. di s. robert p. (1884) perché i ghiacciaj si vadano ritirando. atti della r. accademia dei lincei, transunti, 8, 56-62 doderlein p. (1872) note illustrative della carta geologica del modenese e del reggiano. memoria iii, atti regia accademie scienze, lettere, arti modena, 11, 1-74 eberl b. (1930) die eiszeitenfolge im nôrdlichen alpenvorlande. dr, benno filser verlag, augsburg, pp. 427. emiliani c. (1955) pleistocene temperatures. journal of geology, 63, 538-578. emiliani c., mayeda t., selli r. (1961) palaeotemperature analysis of the plio-pleistocene section at le castella, calabria, southern italy. geological society of america bulletin, 72(5), 679-688. epica community members (2006) one-to-one coupling of glacial climate variability in greenland and antarctica. nature, 444, 195-198. fabrini e. (1890) i machairodus (meganthereon) del valdarno superiore. bollettino del r. comitato geololgico d’italia, ser. 3, 1, 1-43. faranda c., gliozzi e. (2011) a revision of the "northern guest" ostracoda (crustacea) occurence in the quaternary of the mediterranean area. alpine and mediterranean quaternary, 24(1), 75-92. ferrari m. (1977) l’opera scientifica di giuseppe dalla fior. studi trentini di scienze naturali, 54, 5-26. fiebig m., preusser f. (2008) pleistocene glaciations of the northern alpine foreland. geographica helvetica, 63, 145-150. firbas f., zangheri p. (1935) eine glaziale flora von forlì, südlich ravenna. veröffentlichungen des geobotanischen institutes rübel in zürich, 12, 113. flores e. (1895) catalogo dei mammiferi fossili dell’italia meridionale. atti dell’accademia pontaniana, 25 (18), 3-38. follieri m. (1956) primi reperti floristici nell'ambiente dell'elephas dell'aquila. annali di botanica (roma), 25, 91-93. follieri m. (1958a) nuovo metodo per la preparazione di legni fossili pietrificati. nuovo giornale botanico italiano, n.s., 65, 869-871. follieri m. (1958b) la foresta colchica fossile di riano romano. i. studio dei fossili vegetali macroscopici. annali di botanica (roma), 26: 129-142. forno m.g., gattiglio m., comina c., barbero d., bertini a., doglione a., gianotti f., irace a., martinetto e., mottura a., sala b. (2015) stratigraphic and tectonic notes on the villafranca d'asti succession in type-area and castelnuovo don bosco sector (asti reliefs, piedmont). alpine and mediterranean quaternary, 28, 5-27. forsyth major c.i. (1877) considerazioni sulla fauna dei mammiferi pliocenici e postpliocenici della toscana. memorie della società toscana di scienze 31 quaternary studies in italy from arduino to 1950’ naturali, 3, 202-227. forsyth major c.i. (1881) studi sugli avanzi pliocenici del genere sus. atti della società toscana di scienze naturali, processi verbali, 2, 227. forsyth major c.i., (1883) die tyrrhenis: studien über geographische verbreitung von tieren und pflanzen im westlich mittelmeergebiet. kosmos, 13, 81106. forsyth major c.i. (1890) l’ossario di olivola in val di magra (prov. di massa e carrara). atti della società toscana di scienze naturali, processi verbali, 7, 57-78. forsyth major c.i. (1901) on enhydrictis galictoides, a new fossil from sardinia. proceedings of the zoological society of london, 2, 625-628. franchi s., mattirolo e., novarese v., stella a. (1912) carta geologica d’italia 1:100.000, f°42, ivrea. gabert p. (1962) les plaines occidentales du pô et leurs piedmonts (piémont, lombardie occidentale et centrale). étude morphologique. phd thesis, imprimerie louis-jean, gap, pp. 531. galadini f. (2004) quaternary tectonics. in: quaternary. geology of italy (ed. by bosi c.). special volume of the italian geological society, igc florence, 161-188. gastaldi b. (1862) nuovi cenni sugli oggetti di alta antichità trovati nelle torbiere e nelle marniere dell’italia. marzorati, torino. gemellaro g.g. (1866) sulla grotta di carburanceli. nuova grotta ad ossame ed armi in pietra dei dintorni della grazia di carini. giornale di scienze naturali ed economiche, 1, 255-264. giaccio b., leicher n., mannella g., monaco l., regattieri e., wagner b., zanchetta g., gaeta m., marra f., nomade s., palladino d.m., pereira a., scheidt s., sottili g., wonik t., wulf s., zeeden c., ariztegui d., cavinato g.p., dean j.r., florindo f., leng m.j., macrì p., niespolo e., renne p.r., rolf c., sadori l., thomas c., tzedakis p.c. (2019) extending the tephra and palaeoenvironmental record of the central mediterranean back to 430 ka: a new core from fucino basin, central italy. quaternary science reviews 225, 106003. gibbard p.l. (2019) giovanni arduino the man who invented the quaternary. quaternary international, 500, 11-19. gibbard, p.l. head, m.j. (2010) the newly-ratified definition of the quaternary system/period and redefinition of the pleistocene series/epoch, and comparison of proposals advanced prior to formal ratification. episodes, 33(3), 152-158. gignoux m. (1910) sur la classification du pliocène et du quaternarie dans l’italie du sud. comptes rendus de l’académie des sciences, 150, 841-844. gignoux m. (1913) les formations marines du pliocène et quaternaire de l’italie du sud et de la sicile. annales de l’université de lyon, n.s., 36, pp. 693. gignoux m. (1916) l’étage calabrien (pliocène supérieur marin) sur le versant ne de l’apennin, entre le monte gargano et plaisance. bulletin de la société géologique de france 4 (14), 324-348. gignoux m. (1943) géologie stratigraphique. 3° ed., paris. graziosi p., maviglia c. (1946) la grotta di s. teodoro (messina). rivista di scienze preistoriche, 1, 277283. haupt h.o. (1938) die eiszeitliche vergletscherung der bergamasker alpen. dissertation mathematischnaturwissenschaftliche facultät friedrichwilhelms-universität, berlin, pp. 110. hay w.w. (2013) experimenting on a small planet. a scholarly entertainment. springer, berlin. head m.j. (2019) formal subdivision of the quaternary system/period: present status and future directions. quaternary international, 500, 32-51. head m.j., gibbard p.l. (2015) formal subdivision of the quaternary system/period: past, present, and future. quaternary international, 383, 4-35. hearty p., bonfiglio l., szabo b.j., violanti d. (1986) age of late quaternary marine deposits of southern italy determined by aminostratigraphy, faunal correlation, and uranium-series dating. rivista italiana di palaeontologia e stratigrafia, 92(1), 149164. heer o. (1865) die pflanzen der pfahlbauten. neujahrsblatt der naturforschenden gesellschaft in zürich für das jahr 1866, 68, 1-54. issel a. (1914) lembi fossiliferi quaternari e recenti odsservati nella sardegna meridionale dal prof. d. lovisato. rendiconti della r. accademia nazionale dei lincei, classe di scienze fisiche, matematiche e naturali, 23, 759-770. jacomet s. (1998) archaeobotany. a vital tool in the investigation of lake-dwellings. in: living on the lake in prehistoric europe. 150 years of lakedwelling research (ed. by menotti f.). routledge, london, 162-177. johnsen s.j, clausen h.b., dansgaard w., fuhrer k., gundestrup n., hammer c.u., iversen p., jouzel j., stauffer b., steffensen j.p. (1992) irregular glacial interstadials recorded in a new greenland ice core. nature, 359, 311-313. keller f. (1854) die keltischen pfahlbauten in den schweizerseen, band 1. mittheilungen der antiquarischen gesellschaft in zürich, zürich. keller p. (1931) die postglaziale entwicklungsgeschichte der wälder von norditalien. veröffentlichungen des geobotanischen institutes rübel in zürich, 9, 1-187. klebersberg r. (1932) die eiszeitliche vergletscherung der apenninen (2): m. pollino, zeitschrift für gletscherkunde, 20, 52-65. kotsakis t., barisone g. (2008) cenni sui vertebrati fossili di roma. memorie descrittive della carta geologica d’italia, 80(1), 115-143. ligabue g. (1977) leonardo da vinci e i fossili. neri pozza, vicenza, pp. 100. linnaeus c. (1753) species plantarum: exhibentes plantas rite cognitas, ad genera relatas, cum differentiis specificis, nominibus trivialibus, synonymis selectis, locis natalibus, secundum systema sexuale digestas. impensis laurentii salvii, stockholm. linnaeus c. (1758) systema naturæ per regna tria naturæ, secundum classes, ordines, genera, spe 32 orombelli g. et al. cies, cum characteribus, differentiis, synonymis, locis. vol. 1 (10th ed.). laurentius salvius, stockholm, pp. 824. lioy p. (1876) le abitazioni lacustri di fimon. memorie del regio istituto veneto di scienze, lettere ed arti, 19, 1-152. lona f. (1941) analisi polliniche di due torbiere del trentino. studi trentini di scienze naturali, 22(3), 149-171. lona f. (1950) contributi alla storia della vegetazione e del clima nella val padana analisi pollinica del giacimento villafranchiano di leffe (bergamo). atti della società italiana di scienze naturali, 89(3-4), 123-178. lona f. (1962) prime analisi pollinologiche sui depositi terziari-quaternari di castell'arquato; reperti di vegetazione da clima freddo sotto le formazioni calcaree ad amphistegina. bollettino della società geologica italiana, 81(1), 89-91. lona f. (1963) floristic and glaciologic sequence (from donau to mindel) in a complete diagram of the leffe deposit. berichte geobotanische institüt rübel, 34. lona f., follieri m. (1957) successione pollinica della serie superiore (günz-mindel) di leffe (bergamo). veröff. geobotanische institüt rübel in zürich, 34, 86-98. lona f, ricciardi e. (1961) reperti pollinologici nei depositi pleistocenici del bacino lacustre del mercure (italia meridionale, regione lucano-calabra). pollen et spores, 3(1), 85-92. lona f., bertoldi r., ricciardi e. (1969) pliopleistocenic boundary in italy based on the leffian and tiberian vegetational and climatological sequences. viii congrés inqua, paris, 573-574. lona f., bertoldi r. (1972) rinvenimento di arctica (cyprina) islandica in una serie continua pliopleistocenica presso castell'arquato (piacenza) in connessione con sequenze pollinologiche. ateneo parmense. acta naturalia, 8(1), 35-44. lona f., bertoldi r. (1973) la storia del pliopleistocene italiano in alcune sequenze vegetazionali lacustri e marine. memorie della accademia nazionale dei lincei, 11 sez. iii, 1-35. losacco u. (1949) la glaciazione quaternaria dell’appennino settentrionale. rivista geografica italiana, 55, 91-152; 196-272. losacco u. (1982) gli antichi ghiacciai dell’appennino settentrionale. atti della società dei naturalisti e matematici di modena, 113, 1-224. lyell c. (1833) principles of geology. vol. iii. london, john murray, pp. 548. lyell c. (1839) éléments de géologie. paris, chez pitois-levrault et compagnie, 648 pp. malatesta a., zarlenga f. (1986) northern guests in the pleistocene. geologica romana, 25, 91-154. manten a.a. (1967) lennart von post and the foundation of modern palynology. rev. palaeobotan. palynol., 1, 11-22. mariotti lippi m., bandini mazzanti m., bosi g., buonincontri m., castiglioni e., di pasquale g., giardini m., marchesini m., miola a., montanari c., rottoli m., sadori l., mercuri a.m. (2014) archeobotanica. in: la storia delle piante fossili in italia. second ed. (ed. by kustatscher e., roghi g., bertini a., miola a.). pubbl. museo di scienze naturali dell’alto adige, 9, 345-391. martinetto e., ravazzi c., roghi g., teruzzi g., van der ham r., zorzin r. (2015) neotypification of the name juglandites bergomensis, basionym of the fossil-species juglans bergomensis (juglans sect. cardiocaryon, juglandaceae). phytotaxa, 234(3), 280-286. martins c., gastaldi b. (1850) essai sur les terrains superficiels de la vallèe du pô, aux environs de turin, comparés à ceux de la plaine suisse. bulletin de la société géologique de france, 7, 2° serie, 554-605. mattirolo e., novarese v., franchi s., stella a. (1912) carta geologica d’italia 1:100.000 f°28, aosta. meli r. (1882) ulteriori notizie ed osservazioni sui resti fossili rinvenuti nei tufi vulcanici della provincia di roma. bollettino del r. comitato geologico d’italia, 13, 260-368. messerli b. (1967) die eiszeitliche und die gegenwärtige vergletscherung im mittelmeerraum. geographica helvetica, 22, 105-228. milankovitch, m. (1941) kanon der erdbestrahlungen und seine anwendung auf das eiszeitenproblem. royal serbian academy, section of mathematical and natural sciences, 33, belgrade, pp. 633. mochi a. (1911) industria litica (aurignaziana) della grotta romanelli in terra d'otranto. archivio per l’antropologia e l’etnologia, 41, 281-288. molino foti l. (1869) succinta descrizione della geologia di barcellona e territorj circostanti. atti della società italiana di scienze naturali, 12, 661-715. montcharmont zei m., d'erasmo g. (1955) il cranio giovanile di elephas antiquus di pignataro interamna nella valle del liri, atti dell’accademia delle scienze fisiche e matematiche, s.3, 6, 1-32. nangeroni g. (1929) la glaciazione gunz ed il primo interglaciale nella regione varese-malnate (lombardia occidentale). atti della società italiana di scienze naturali, 68(2), 144 -168, nangeroni l.g. (1930) morene stadiarie nella val malenco. atti della società italiana di scienze naturali, 69(1), 1-21. nangeroni g. (1950) nuove osservazioni sul morenico gunz nella lombardia estrema occidentale. atti della società italiana di scienze naturali, 89(3-4), 202-212. nangeroni g. (1954a) i terreni pleistocenici dell’anfiteatro morenico del verbano e del territorio varesino. atti della società italiana di scienze naturali, 93(12), 7-106. nangeroni g. (1954b) il morenico del lario orientale della valsassina e della vallassina. atti della società italiana di scienze naturali, 93(1-2), 179-220. nangeroni g. (1945c) riassunto dei cinque studi. atti della società italiana di scienze naturali, 93(1-2), 363-365. nesti f. (1808) di alcune ossa fossili di mammiferi che s’incontrano nel valdarno. annali del museo imperiale di fisica e storia naturale di firenze, 1, pp. 12. 33 quaternary studies in italy from arduino to 1950’ nesti f. (1825) lettere sopra alcune ossa fossili del valdarno non paranco descritte. nuovo giornale de’ letterati, 11, 195-216. neuweiler e. (1905) die prähistorischen pflanzenreste mitteleuropas mit besonderer berücksichtigung der schweizerischen funde. arbeiten aus dem botanischen museum des eidgenössischen polytechnikums, 13, 23-134. novarese v. (1915) il quaternario in val d’aosta e nelle valli del canavese. bollettino del r. comitato geologico d’italia, 45, 137-195. novarese v. (1916) gli stadi postwurmiani nella valle d’aosta. la geografia, 4, 73-85. omboni g. (1861a) sul terreno erratico della lombardia. atti della società italiana di scienze naturali, 2, 6-21. omboni g. (1861b) i ghiacciaj antichi e il terreno erratico di lombardia. atti della società italiana di scienze naturali, 3, 232-299. omboni g. (1877) il mare glaciale e il pliocene ai piedi delle alpi lombarde. atti della società italiana di scienze naturali, 19(2-3), 372-384 ottman f. picard j. (1954) contributions à l’étude du quaternaire des régions de palerie et de milazzo (sicilie). bulletin de la societé géologique de france, s.6, 4(1-3), 395-405. paganelli a. (1956) analisi pollinica di depositi torbosi e lacustri del piano di colfiorito (appennino umbro -marchigiano). bollettino della società eustachiana, 49(3-4), 71-91. paganelli a. (1958) cicli forestali postglaciali del piano montano dell’appennino umbro-marchigiano attraverso l’analisi pollinica del deposito lacustre dei “pantani” (m 1589). nuovo giornale botanico italiano, 65(1-2), 202-213. paganelli a. (1959) analisi pollinica del deposito pleistocenico di gelagna bassa (appennino umbromarchigiano). bollettino del servizio geologico d’italia, 81(2-3), 1-18. paganelli a., bertolani marchetti d. (1988) research in palynology in italy. il quaternario, 1, 55-61. paglia e. (1861) sulle colline di terreno erratico intorno all’estremità meridionale del lago di garda. atti della società italiana di scienze naturali, 2, 337342 palombo m.r. (2018) insular mammalian fauna dynamics and palaeogeography: a lesson from the western mediterranean islands. integrative zoology, 13(1), 2-20. palombo. m.r. (2021) le quaternaire italien dans une perspective méditerranéenne: état de l'art et perspectives. mèmoires du service géologique de l'algérie, 22, 162-232. palombo m.r., antonioli f., di patti c., valeria l.p., scarborough m.e. (2021) was the dwarfed palaeoloxodon from favignana island the last endemic pleistocene elephant from the western mediterranean islands? historical biology, 33(10), 2116-2134. pareto l. (1846a) carta geologica della liguria marittima. tipografia ferrando, genova. pareto l. (1846b) geologia. in: descrizione di genova e del genovesato, v.1, 37-137, tipografia ferrando, genova. pareto l. (1865) note sur les subdivisions que l’on pourrait établir dans les terrains tertiaires de l’appenin septentrional. bulletin de la société géologique de france, 22, 210-277. pasini g., colalongo m.l. (1997) the pliocenepleistocene boundary-stratotype at vrica, italy. in: the pleistocene boundary and the beginning of the quaternary (ed. by van couvering j.a.). cambridge university press, cambridge, 15-45. penck a., brückner e., du pasquier l. (1894) le système glaciaire des alpes. bulletin de la société des sciences naturelles de neuchâtel, 22, 70-83. penck a., brückner e. (1909) die alpen im eiszeitalter. vol.3 die eiszeiten in den südalpen und im bereich der ostabdachung der alpen. c.h. tauchnitz, leipzig, pp. 1199. pfeffer k.h. (1967) beiträge zur geomorphologie der karstbecken im bereich des monte velino (zentralapennin). frankfurter geographische hefte, 42, pp. 86. philippi r.a. (1834-1836) enumerazio molluscorum siciliae cum viventium in tellure tertiaria fossilium, i.s. shropp. berlin, 13-28. pilla l. (1845) saggio comparativo dei terreni che compongono il suolo d'italia. pisa, presso i fratelli nistri, pp. 137. pilla l. (1847-51) trattato di geologia. (parte seconda classificazione e descrizione cronologica delle rocce). tipografia vannucchi, pp. 626. pirona g.a. (1861) sulle antiche morene del friuli. atti della società italiana di scienze naturali, 2, 348356. ponzi g. (1862a) dell’aniene e dei suoi relitti. atti dell'accademia pontificia dei nuovi lincei, 15, 132. ponzi g. (1862b) sugli animali fossili che precedettero l’uomo in italia centrale. giornale arcadico di scienze, lettere ed arti, n. ser., 26, 1-44. ponzi g. (1875) cronaca subappennina o abbozzo d’un quadro generale del periodo glaciale. atti xi congresso degli scienziati italiani, 1873, roma, 268-346. ponzi g. (1878) le ossa fossili subappennine dei dintorni di roma. memorie della r. accademia dei lincei, ser.3, 2, 709-736. ponzi g. (1883) sulle ossa fossili rinvenute nella cava dei tufi vulcanici della sedia del diavolo sulla via nomentana presso roma. bollettino del r. comitato geologioco d’italia, 14, 91-93. ponzi g., meli r. (1887) molluschi fossili del monte mario presso roma. memorie della reale accademia dei lincei, classe di scienze fisiche matematiche e naturali, s.4, 2, 672-698. portis a. (1893-1896) contribuzioni alla storia fisica del bacino di roma e studii sopra l’estensione da darsi al pliocene superiore. vol.1-2. roux e c. editori, torino. portis a. (1920) elenco delle specie di cervicorni fossili in roma e attorno a roma. bollettino della società geologica italiana, 39, 132-139. pracchi r. (1954) il quaternario nel lario occidentale. atti della società italiana di scienze naturali, 93(1 34 orombelli g. et al. 2), 111-178. railsback b.l., gibbard p.l., head m.j., riavo n., voarintsoa g., toucanne s. (2015) an optimized scheme of lettered marine isotope substages for the last 1.0 million years, and the climatostratigraphic nature of isotope stages and substages. quaternary science reviews, 111, 94-106. reboul h. (1833) géologie de la période quaternaire. paris, f.g. levrault, libraire, pp. 236. rellini u. (1920) cavernette e ripari preistorici nell’agro falisco. monumenti antichi dei lincei, 26. ristori g. (1897) l’orso pliocenico del valdarno e di olivola. palaeontographica italica, 3, 15-76 riva a. (1942) il morenico antico in brianza. bollettino del comitato glaciologico italiano, 22, 1-6. riva a. (1957) gli anfiteatri morenici a sud del lario e le pianure diluviali tra adda ed olona. atti dell’istituto geologico dell’università di pavia, 7, pp. 97. romo mulas r.a. (2018) i grandi studiosi della geologia di cagliari: dai dati storico-scientifici alla divulgazione ict. tesi di laurea in scienze della terra, università di cagliari. ruggieri g. (1954) la limite entre pliocène et quaternaire dans la série plio-pléistocène du santerno. congrès géologique international, comptes rendus de xix session, alger 1952. comptes rendus, 15, 235-240. ruggieri g. (1957) nuovi dati sul contatto pliocenecalabriano nella sezione del santerno (imola). giornale di geologia, 26, 1-8. ruggiero g., greco a. (1965) studi geologici e palaeontologico su capo milazzo con particolare riguardo al milazziano. geologica romana, 4, 4188. ruggieri g, selli r. (1949) il pliocene ed il post pliocene dell’emilia. giornale di geologia, 20, 1-14. ruggieri g., selli r. (1950) il pliocene e il postpliocene dell’emilia. 18th international geological congress, proceedings part 9, section h, london, 8593. ruggieri g., unti a., unti m., moroni m.a. (1977) la calcarenite di marsala (pleistocene inferiore) e i terreni contermini. bollettino della società geologica italiana, 74, 1623-1657. sacco f. (1893) lo sviluppo glaciale nell’appennino settentrionale. bollettini del club alpino italiano, 27, 263-282 sacco f. (1919) le oscillazioni glaciali. atti della reale accademia delle scienze di torino, 55, 139-157. scarabelli g. (1852) sopra i depositi quaternarj dell’imolese, rettifica di alcune opinioni intorno alla giacitura delle ossa fossili. annali di scienze matematiche e fisiche, 3, 33-42. scarabelli g. (1853) carta geologica della provincia di bologna. angiolini, bologna. scarabelli g. (1854) carta geologica della provincia di ravenna. angiolini, bologna. scarabelli g. (1887) stazione preistorica del m. castellaccio presso imola. galeati, imola. selli r. (1954) la limite plio-pleistocène dans les environs d’ancona. congrès géologique international, comptes rendus de xix session, alger 1952. comptes rendus, 15, 241-247. selli r. (1967) cenni geologici sul pedeappennino emiliano fra bologna e piacenza. guida alle escursioni. iv congr. neogene del mediterraneo, bologna, 88-97. selli r. (1973) pleistocene marino: margine settentrionale degli appennini. in: geologia dell’italia (ed. by desio a.). unione tipografico-editrice torinese, torino, 685-688. sergi s. (1929) la scoperta di un cranio del tipo di neanderthal presso roma. rivista di antropologia, 28, 457-462. sergi s. (1944) craniometria e craniografia del primo paleantropo di saccopastore. ricerche di morfologia, 20(21), 733-791. sergi s. (1948) l’uomo di saccopastore. palaeontographia italica, 42, 25-164 sestini a. (1940) l’italia nell’età quaternaria, l’appennino centrale durante il periodo glaciale, 1:200,000. in: atlante fisico-economico d’italia (ed. by dainelli g.). consociazione turistica italiana. shackleton n.j., opdyke n.d. (1973) oxygen isotope and palaeomagnetic stratigraphy of equatorial pacific core v28-238: oxygen isotope temperatures and ice volumes on a 105 year and 106 year scale. quaternary research, 3, 39-55. shackleton n.j., opdyke n.d. (1976) oxygen isotope and palaeomagnetic stratigraphy of pacific core v28-239, late pliocene to latest pleistocene. geol. soc. america memoir, 145, 449-464. shackleton n.j., opdyke n.d. (1977) oxygen isotope and palaeomagnetic evidence for early northern hemisphere glaciation. nature, 270, 216-219. šibrava v., bowen d.q., richmond g.m. (eds., 1986) quaternary glaciations in the northern hemisphere. quaternary science reviews, 5, 1-511. sordelli f. (1873) descrizione di alcuni avanzi vegetali delle argille plioceniche lombarde. atti della società italiana di scienze naturali, 16, 350-429. sordelli f. (1875) la fauna marina di cassina rizzardi osservazioni palaeontologiche. atti della società italiana di scienze naturali, 18, 308-357. sordelli f. (1878) le filliti della folla d'induno presso varese e di pontegana tra chiasso e balerna nel canton ticino paragonate con quelle di altri depositi terziari e posterziari. atti della società italiana di scienze naturali, 21, 1-23. sordelli f. (1880) sulle piante della torbiera e della stazione preistorica della lagozza nel comune di besnate. atti della società italiana di scienze naturali, 23, 219-241. sordelli f. (1896) studi sulla vegetazione di lombardia durante i tempi geologici. cogliati, milano. spreafico e., negri g., stoppani a. (1873) geologischer karte der schweiz 1:100.000 blatt xxiv lugano-como. sprovieri r., d’agostino s., di stefano e. (1973) giacitura del calabriano nei dintorni di catanzaro. rivista italiana di palaeontologia, 79, 27-140. stella a. (1895) sui terreni quaternari della valle del po in rapporto alla carta geologica d’italia. bollettino del r. comitato geologico d’ italia, 26, 108136. sternberg g.k. (1820-1828) versuch einer geognosti 35 quaternary studies in italy from arduino to 1950’ sch botanischen darstellung der flora der vorwelt. druck und papier von gottlieb haase söhne. stoppani a. (1867) note ad un corso annuale di geologia. parte seconda geologia stratigrafica. milano, tipografia g. bernardoni, pp. 468. stoppani a. (1872) nota sull'esistenza di un antico ghiacciaio nelle alpi apuane, atti della società italiana di scienze naturali, 15, 133-134. stoppani a. (1873) corso di geologia vol. ii geologia stratigrafica. milano, g. bernardoni e g. brigola editori, pp. 868. stoppani a. (1880) l’era neozoica. milano, vallardi, pp. 364. strobel p., pigorini l. (1864) le terramare e le palafitte del parmense. atti della società italiana di scienze naturali, 7, 27-33. studiati c. (1857) descriptions des fossiles de la brèche osseuse de monreale de bonaria près de cagliari. in: de la marmora a., voyage en sardaigne, iii partie, 2. g. bocca libraio del re, torino, 651-704. suter k. (1939) die eiszeitliche vergletscherung des zentralapennins. vierteljahrsschrift naturf. gesell. zürich, 84(31), 1-140. suter k. (1940) la glaciation quaternaire de l’apennin central. revue de géographie alpine, 28(4), 491510. taramelli t. (1870) sugli antichi ghiacciai della sava, della drava e dell’isonzo. atti della società italiana di scienze naturali, 13, 224-238. taramelli t. (1875) dei terreni morenici ed alluvionali del friuli. annali r. istituto tecnico di udine, vol.ix, pp. 100. taramelli t. (1881) carta geologica del friuli con spiegazione della carta geologica del friuli, pavia, tipografia fusi, 188 pp. taramelli t. (1903) i tre laghi studio geologico orografico con carta geologica. milano, artaria, pp. 125. taramelli t. (1910) quelques observations sur les changements du climat postglaciaire en italie. die veränderungen des klimas seit dem maximum der lotaten eiszeit. international geological congress 11th, stockholm, 1910, 73-78. targioni tozzetti g. (1752) relazioni d’alcuni viaggi fatti in diverse parti della toscana, per osservare le produzioni naturali e gli antichi monumenti di essa. stamperia imperiale, firenze. targioni tozzetti g. (1754) prodromo della corografia e topografia della toscana. stamperia imperiale, firenze. tomasi g. (2010) per l'idea di natura. storia del museo di scienze naturali di trento. muse-museo delle scienze. trevisan l. (1940) i limiti nivali attuali e würmiani in italia. bollettino del comitato glaciologico italiano, 20, 49-62. tuccimei g. (1889) il villafranchiano nelle valli sabine e i suoi fossili caratteristici. bollettino della società geologica italiana, 8, 13-58. unger f. (1850) genera et species plantarum fossilium. vindobonae, w. braunmüller, pp. 627. vaufrey r. (1929) les éléphants nains des îles méditerranéennes et la question des isthmes pléistocènes. archives de l’institut de paléontologie humaine, 6,1-220. vecchia o. (1954) i terreni glaciali pleistocenici dei dintorni del lago d’iseo (lombardia). atti della società italiana di scienze naturali, 93 (1-2), 235362. venturi g. (1817) memoria intorno ad alcuni fenomeni geologici. pavia, fusi e comp., pp. 37 (in giornale di fisica, chimica e storia naturale, pavia, 10(4), bim, 292-307, 317-338). venzo s. (1948) rilevamento geomorfologico dell’apparato morenico dell’adda di lecco. atti della società italiana di scienze naturali, 87(1-2), 79-149. venzo s. (1950) rinvenimento di anancus arvernensis nel villafranchiano dell’adda di paderno, di archidiskodon meridionalis e cervus a leffe. stratigrafia e clima del villafranchiano bergamasco. atti della società italiana di scienze naturali, 89(1-2), 43-122. venzo s. (1955) le attuali conoscenze sul pleistocene lombardo con particolare riguardo al bergamasco. atti della società italiana di scienze naturali, 94(2) 155-200. venzo s. (1957) rilevamento geologico dell’anfiteatro morenico del garda. parte i: tratto occidentale gardone-desenzano. memorie della società italiana di scienze naturali, xii(ii), 72-140. venzo s. (1961) rilevamento geologico dell’anfiteatro morenico del garda. parte ii: tratto orientale garda-adige e anfiteatro atesino di rivoli veronese. memorie della società italiana di scienze naturali, xiii(i), 1-64. venzo s. (1965) rilevamento geologico dell’anfiteatro morenico frontale del garda dal chiese all’adige. memorie della società italiana di scienze naturali, xiv(i), 1-82. vialli v. (1956) sul rinoceronte e l'elefante dei livelli superiori della serie lacustre di leffe (bergamo). memorie della società italiana di scienze naturali, 12(1), 1-67. vialli v. (1967) l’antico bacino lacustre di leffe. natura e montagna, 7(4),18-27. villa g.b. (1857) osservazioni geognostiche e geologiche fatte in una gita sopra alcuni colli del bresciano e del bergamasco. estratto del giornale dell’ingegnere-architetto ed agrononomo, anno v., milano, tip. di domenico salvi e comp., pp. 8. villa, b.g. (1864) sulle torbe della brianza. atti della società italiana di scienze naturali, 6, 393-396. von post l. (1909) stratigraphische studiën über einige torfmoore in narke. geologiska foreningens i stockholm fophandlingar, 31(7), 629-706. von post l. (1916) einige siidschwedischen quellmoore. bulletin of the geological institution of the university of uppsala, 15, 219-278. wagner r. (1829) ueber den zahnbau der gattung lagomys. isis von oken, 22, 1132-1141. weithofer a. (1893) proboscidiani fossili del valdarno in toscana. memorie per servire alla descrizione della carta geologica d’italia, reale comitato geo 36 orombelli g. et al. ms. received: december 1 2022 revised: january 23, 2023 accepted: march 14, 2023 available online: april 1, 2023 logico, 4(2), 115-145. wettstein r. (1892) die fossile flora der höttinger breccie. denkschriften der kaiserlichen akademie d e r w i s s en s c h a f t e n , m a t h e m a t i s c h naturwissenschaftliche classe, 59, 479-524. white t.d., toth n., chase p.g., clark g.a., conrad n.j., cook j., d'errico f., donahue r.e., gargett r.h., giacobini g., pike-tay a., turner a. (1991) the question of ritual cannibalism at grotta guattari [and comments and replies]. current anthropology, 32(2), 118-138. zagwijn w.h. (1957) vegetation, climate and timecorrelations in the early pleistocene of europe. geologie en mijnbouw, 19, 233-244. zedda m., brunetti a., palombo m.r. (2022) first attempt to infer sound hearing and its palaeoenvironmental implications in the extinct insular canid cynotherium sardous studiati, 1857 (sardinia, italy). animals, 12(7), 833. 37 quaternary studies in italy from arduino to 1950’ 38 imp.corazza& geologia, idrogeologia e approvvigionamento idrico del colle capitolino (roma, italia) angelo corazza1, leonardo lombardi2 & fabrizio marra3 1via ettore rolli, 30 roma e-mail:corazza.a@libero.it 2via gaetano sacchi, 20 roma e-mail:leonardo.lombardi@libero.it 3istituto nazionale di geofisica e vulcanologia. via di vigna murata, 605 roma e-mail: marra@ingv.it. riassunto: a. corazza et al., geologia, idrogeologia e approvvigionamento idrico del colle capitolino (roma, italia). (it issn 03943356, 2004) tramite lo studio degli affioramenti residui e la reinterpretazione di 104 stratigrafie di sondaggi geognostici sono state ricostruite la geologia e la morfologia originaria del colle campidoglio, ricostruzione altrimenti ostacolata dalla secolare antropizzazione del sito e dalla diffusa presenza di riporti. l’uso della moderna stratigrafia romana, basata sull'identificazione di successioni sedimentarie aggradazionali depostesi in corrispondenza della risalita del livello del mare ad ogni terminazione glaciale, e sulla determinazione dell'età radiometrica dei prodotti dell'attività eruttiva dei distretti vulcanici sabatino e albano intercalati in queste successioni, ha permesso di ricostruire i rapporti tra le varie formazioni e di reinterpretare alcune antiche sezioni geologiche note dalla letteratura. si è inoltre condotto uno studio di dettaglio dell'idrogeologia del colle che ha permesso di chiarire l’alimentazione della sorgente del tullianum e si è potuto inserire tra le sorgenti romane una nuova emergenza: la fons servilli. infine si è fornito un quadro diacronico dell’approvvigionamento idrico del colle. abstract: a. corazza et al., geology, hydrogeology and water supply of the campidoglio hill (rome, italy). (it issn 0394-3356, 2004) in order to reconstruct the geology and the original morphology of the capitoline hill, nowadays hindered by the secular presence of human settlements and by a thick cover of manmade fill, we have combined the study of the remaining outcrops with the re-interpretation of 104 borehole stratigraphies. by using a modern concept to describe the stratigraphy of the area of rome, which is based on the definition of aggradational successions deposited in response to sea-level rise at each glacial termination, and using radiometric ages determined on interbedded volcanic products of the colli albani and monti sabatini districts, we have been able to reconstruct stratigraphic relationships among different sedimentary cycles and to reinterpret some ancient geologic sections known in the literature. we also have made a detailed hydrogeologic study of the hill, which allowed us to identify the alimentation of the tullianum spring and to recognize a new spring: the fons servilli. finally, we present here a diachronic picture of the hydric supply of the capitoline hill. parole chiave: campidoglio, geomorfologia, idrogeologia. keywords: campidoglio, geomorphology, hydrogeology. il quaternario italian journal of quaternary sciences 17(2/2), 2004, 413-441 1. premessa il campidoglio è stato oggetto di studi geologici e morfologici fin dai primi decenni dell’800. il presente studio ha avuto origine da una ricerca, effettuata per conto della soprintendenza archeologica di roma, sulla sorgente presente all’interno del tullianum, il carcere mamertino1. a partire da un primo tentativo di sintesi effettuato per quel lavoro, si è qui cercato di fare il punto e di aggiornare le conoscenze geologiche e morfologiche sul colle capitolino, anche attraverso l’impiego di nuove metodiche che hanno permesso di correlare meglio la storia geologica del colle con il più vasto quadro dell’evoluzione gemorfologica del territorio romano. il capitolino è uno dei colli sui quali, e intorno ai quali, è nata e si è sviluppata la città di roma. l’assetto morfologico ha subito continue modifiche nel corso del tempo. il colle, infatti, ha subito gli effetti degli agenti atmosferici e dell’erosione fluviale che lo hanno inciso, isolato, scalzato alle pendici e, progressivamente, ridotto nelle sue dimensioni attuali. inoltre esso ha subito, più di altre aree romane, continue aggressioni antropiche con tagli, escavazioni, accumuli di materiali da costruzione e sovrapposizione di edifici che nel corso di oltre tre millenni ne hanno notevolmente alterato l’aspetto originale. la sua natura geologica, in parte peculiare rispetto agli altri colli romani, è per gran parte mascherata dagli edifici, anche se con gli “sventramenti” della fine dell’800 e del ‘900, e con gli scavi recenti, sono emersi e in parte restano ancora visibili, numerosi affioramenti dei terreni geologici che lo costituiscono. di più vasti affioramenti ci sono giunte le descrizioni, soprattutto relativamente alla realizzazione degli interventi urbanistici per la costruzione del vittoriano e per l’apertura di via dell’impero, ora via dei fori imperiali. l’insieme dell’assetto geologico è stato ricostruito, in gran parte, grazie allo studio e alla reinterpretazione dei dati di oltre 100 perforazioni e sondaggi eseguiti nell’area. inoltre di grande aiuto sono state le informazioni di carattere geologico ricavate dai risultati degli scavi archeologici. 1 la ricerca ha dato luogo a una mostra, tenutasi a roma nel 1998, e alla pubblicazione di un catalogo (fortini 1998) nel quale venivano esposti i primi risultati dello studio sull’area. 414 a. corazza, l. lombardi & f. marra gli elementi di novità emersi dallo studio sono così riassumibili: a) nuova ricostruzione dell’assetto geologico e morfologico dell’intera collina; b) attribuzione certa alle unità stratigrafiche romane, di recente istituzione, di alcuni dei terreni geologici del campidoglio, tramite l’uso di datazioni radiometriche; c) ricostruzione dell’assetto idrogeologico del colle; reinterpretazione geologica e storica sull’origine e la storia della sorgente del tullianum; individuazione e localizzazione di una sorgente (fons servilii) prima mai citata nei testi geologici riguardanti il colle. d) ricostruzione della storia dell’approvvigionamento idrico del colle 2. cenni generali sul colle il colle capitolino, allo stato attuale, è parzialmente circondato da zone di pianura e ha l’aspetto di un trapezoide, allungato sw-ne. ancora oggi nella collina è possibile distinguere due sommità, note fin dall’antichità, l’arx (a nord) e il capitolium (a sud), separate da una sella, l’asylum, corrispondente approssimativamente all’attuale piazza del campidoglio. il colle si affaccia, a nord, sulla spianata di piazza venezia e sulla piazza dell’ara coeli; a sud, sul pianoro del foro romano, sulla piazza e la via della consolazione e sul vicus jugarius; ad est sul foro di cesare e, a ovest, sulla via del teatro marcello, che risale fino a piazza dell’ara coeli. tra il colle capitolino e il foro scorreva, fino ad epoca arcaica, un torrente, lo spinon degli antichi, in parte impaludato fino alla confluenza con il tevere (lanciani, 1975, tav. ii, fig. 1). fino ad alcune migliaia di anni or sono, il tevere, nei periodi di piena, occupava la parte bassa dell’attuale zona di via del teatro di marcello, e arrivava a lambire la collina nell’area dove ora è piazza venezia il colle capitolino era unito al colle quirinale da una sella, non molto alta (de angelis d’ossat, 1940), che rappresentava lo spartiacque tra la valle del tevere e la valle dello spinon, che discendeva dai rilievi dell’esquilino. la sella fu in parte spianata da cesare per la costruzione del suo foro e, in seguito, da traiano che rimodellò tutta l’area per la costruzione del foro e dei mercati. la colonna traiana porta un’iscrizione che indicherebbe l’altezza dello scavo realizzato, pari all’altezza della colonna stessa. da un esame delle stratigrafie dei sondaggi esaminati risulta che uno spesso accumulo di materiale di riporto2 ha rialzato quasi ovunque il terreno rispetto al suo livello originario, per cui i depositi alluvionali delle piane del tevere e dello spinon, ma, in parte, anche i terreni vergini delle sommità del colle e dei suoi versanti sono attualmente sepolti alcuni metri sotto il piano di calpestio attuale. senza lo strato di riporti le due piane ci apparirebbero nello stato in cui si trovavano prima degli insediamenti umani. nelle parti rilevate, oltre ai riporti, l’assetto morfologico originario è stato fortemente alterato dagli importanti sbancamenti e scavi che avrebbero asportato, all’intorno e sulle sommità del rilievo, volumi considerevoli di terreno. anche la bassa sella tra campidoglio e quirinale, come già ricordato, fu notevolmente modificata con importanti opere di scavo eseguite sia da cesare che da traiano. per la realizzazione del foro di cesare i terreni geologici sono stati spianati e scavati con un abbassamento del livello di almeno due metri, come risulta chiaramente dagli scarsi affioramenti residui e dai sondaggi. nel secolo scorso la sella e lo stesso colle capitolino sono stati ulteriormente modificati per la costruzione del vittoriano e la realizzazione di via dei fori imperiali e di via della consolazione (muñoz & colini, 1930; muñoz, 1943). inoltre la presenza di numerose cavità artificiali ancora osservabili, sommate a quelle rinvenute durante i lavori per la realizzazione del vittoriano, dimostrano che ai piedi del campidoglio sono state attive per alcuni secoli vaste cave per l’estrazione dei tufi utilizzati come materiali da costruzione. i fronti di cava a cielo aperto hanno indubbiamente alterato la morfologia originaria, così come l’hanno alterata i tagli per realizzare gli imponenti terrazzamenti e per fare spazio alle nuove costruzioni. anche alcune frane storiche, come vedremo, hanno contribuito alla modifica dei cigli delle scarpate che caratterizzano il rilievo. la fig. 1 fornisce una visione dall’alto del colle. 2 si intende per riporto un accumulo di materiale eterogeneo, di origine sempre antropica che, per motivi vari (costruzioni, demolizioni, incendi, discariche, ecc), si è accumulato in un dato luogo, sovrapponendosi agli strati geologici. fig. 1 il campidoglio visto dall’alto. aerial view of the capitoline hill. se si considerano tutti questi elementi è chiaro che diventa estremamente difficile riuscire a ricostruire il preciso assetto morfologico del campidoglio quando, nell’età del bronzo, i primi uomini si installarono sul colle e lungo le sue pendici. tenendo conto di tutto ciò, in questo studio si è cercato di ricostruire un’immagine quanto più fedele possibile di quello che doveva essere l’aspetto originale del colle capitolino, attraverso la raccolta e la revisione di tutti i dati esistenti in letteratura, e con l’ausilio di nuovi elementi recentemente acquisiti. 3. cenni alla storia antropica del colle vengono riportati alcuni cenni alla storia del colle al solo fine di fornire elementi per una valutazione degli interventi antropici che nel tempo hanno interessato il colle con costruzioni e distruzioni che si sono succedute da epoca arcaica ai nostri giorni. le vestigia più antiche rinvenute in scavi recenti sul campidoglio risalgono all’età del bronzo recente, tra il 1400 e il 1100 a.c. (canfora, 2000; cazzella 2001), ma è possibile che ulteriori ricerche consentano nuovi e forse più antichi ritrovamenti su questo colle che si presentava morfologicamente isolato, quindi difendibile, e con facile accesso all’acqua del tevere, a quella del torrente spinon e alle emergenze sorgentizie presenti al piede del rilievo. dal vi secolo a.c. le due sommità del colle sono state la sede di funzioni politiche e di culto di fondamentale importanza per roma. la carta archeologica del colle mostra la densità dei ritrovamenti (fig. 2). sulla sommità occidentale sorse il più importante centro di culto di stato romano, il capitolium, tempio della triade capitolina: giove, giunone, minerva. l’area di fronte al tempio era occupata da templi minori, sacelli, trofei e statue. tra i monumenti più importanti si ricordano i templi di ops, di fides e l’arco di trionfo di scipione l’africano. tante erano le costruzioni sulla sommità occidentale che, per edificare nuovi edifici, vista l’assenza di spazio, era necessario demolire quelli esistenti. ma la rimozione di statue e effigi si doveva anche ad altre cause. svetonio (i-ii sec.d.c., cal. 34) riferisce che caligola elimina tutte le statue che augusto aveva posto sul colle. 415geologia, idrogeologia e ... nel i secolo a.c. la depressione dell’asylum, fu chiusa, sul lato sud, dal tabularium (coarelli, 1995, p. 44) l’edificio a pianta trapezoidale, con i lati corti convergenti verso l’attuale piazza del campidoglio, era destinato a conservare l’archivio dello stato romano. la facciata del tabularium chiude verso nord, con il suo basamento lungo 73,60 metri, la valle del foro. una galleria coperta percorreva tutta la lunghezza del monumento e collegava l’arx con il capitolium (mura sommella, 1984). a nord del tabularium era posizionato il tempio di veiove (colini, 1942; albertoni, 1997, p. 21-22). nella depressione dell’asylum, durante lo scavo di una galleria realizzata nel 1940 sotto la piazza per collegare il museo del palazzo dei conservatori con il museo del palazzo nuovo, sono venute alla luce altre rovine. si tratta dei ruderi di alcune case di abitazione del ii secolo d.c. poggiate su strutture di epoca repubblicana (albertoni, 1997, p. 20). sulla sommità orientale, l’arx, vi era il tempio di giunone moneta (ammonitrice). sui versanti del colle e ai suoi piedi ci fu un intenso sviluppo urbanistico con case anche di più piani, delle quali l’insula ai piedi della scala che sale all’ara coeli è un chiaro testimone (packer, 1972). lungo tutte le pendici si sono rinvenuti, negli scavi degli anni ’30 del secolo scorso realizzati per la “liberazione del campidoglio”, strutture murarie ed edifici antichi, particolarmente sui lati occidentale e meridionale del colle (muñoz & colini, 1930). in epoca romana la costruzione di ogni edificio ha comportato lavori di modellamento del colle dei quali si fornisce un elenco esemplificativo, non esaustivo e non in ordine cronologico: l’apertura delle strade e delle scale che davano accesso ai templi, il livellamento del fig. 2 carta archeologica del colle (disegno di g. joppolo da albertoni 1997). archaeological map of the capitoline hill (drawing by g. joppolo from albertoni, 1997). 416 terreno su cui sorse il tempio di giove e gli altri edifici, i terrazzamenti, la realizzazione di muri di contenimento (fortini, 2000), la messa in opera delle c.d. mura serviane a protezione delle alture e, infine, i tagli per lo sfruttamento del tufo, prezioso materiale da costruzione, di facile estrazione e di semplice trasporto. questi pochi dati per ricordare che il campidoglio, in epoca antica, fu sede di importanti interventi edificatori e urbanistici di tipo pubblico, ma fu anche luogo di civili abitazioni che occupavano le pendici del rilievo e lo stesso asylum, tanto che in quell’epoca tutto il colle era coperto da strutture murarie. per queste note sono state di fondamentale aiuto i lavori di lanciani (1902, 1975, 1985), lugli (1946) e coarelli (1995). in periodo tardo antico i monumenti, abbandonati, caddero in rovina uno dopo l’altro e sul colle si insediarono comunità religiose, con chiese e conventi, in parte costruiti con materiali di recupero, prelevati dai numerosi edifici esistenti nell’area. tra le altre inizia, nell’viii secolo, la lunga e travagliata storia della basilica dell’ara coeli, esemplificativa del travaglio edilizio del colle. per la storia della basilica si fa costante riferimento al lavoro di brancia di apricena (2000). la basilica nata come monastero benedettino, diviene abbazia e dal ix secolo prende il nome di santa maria de o in campidoglio. nel xiii secolo passa all’ordine dei francescani, che le danno il nome di santa maria dell’ara coeli. la chiesa e il convento vengono ampliati con lavori di tale mole che comportarono certamente la distruzione di quanto rimaneva delle strutture antiche, in particolare del tempio di giunone moneta. la basilica poggia su strutture antiche e il terreno vergine si rinviene a. corazza, l. lombardi & f. marra fig. 3 veduta del campidoglio di maggi-maupin losi –xvi sec. (da brancia di apricena 2000). view of the capitoline hill by maggi-maupin losi, xvith century (from brancia di apricena, 2000). 417 a tre o quattro metri di profondità dal livello attuale. i lavori proseguirono nei secoli successivi con la costruzione di altri edifici e di un secondo grande chiostro. nel medio evo, in corrispondenza della sella tra le due cime del colle, le strutture del tabularium vengono trasformate dalla famiglia corsini in fortezza che, nel 1105, fu fatta in parte demolire dal pontefice pasquale ii. pochi decenni dopo, sui resti della fortezza, viene costruito il palazzo senatorio. dal 1143 il campidoglio recupera il suo ruolo di centro politico e religioso e diviene la sede delle decisioni importanti per la città. le lotte tra papato e comune si svolgono, direttamente o indirettamente, sul colle, ove ha sede il senato, mentre la basilica dell’ara coeli assume sempre più importanza e, nel 1348, si abbellisce della scalinata che sale da piazza dell’ara coeli. il palazzo senatorio, il palazzo dei conservatori trasformato a metà del 1400 e le nuove costruzioni di paolo ii a ridosso della chiesa, già occupano praticamente tutto il colle e sono la premessa per le grandi trasformazioni di paolo iii farnese. per opera di questo papa, nel 1500, nasce il nuovo palazzo papale (la torre di paolo iii), si trasformano i palazzi che si affacciano sulla piazza e si regolarizzano le pendici del colle che viene di nuovo circondato da mura. il portico del vignola, con la scala, che collega la piazza del campidoglio al monastero dell’ara coeli, e la scala tra il p. senatorio e quello conservatori, completano l’insieme edilizio cinquecentesco della piazza. il progetto, di michelangelo, verrà terminato con la realizzazione del palazzo nuovo, nel 1600. alle spalle del palazzo senatorio viene costruito, alla fine del 1500, il palazzo caffarelli, che sorge sopra le rovine del tempio di giove. l’attività edilizia monumentale ha, quindi, una sosta e si chiude la fase antica dei grandi interventi pubblici che di nuovo, come in epoca imperiale, ricoprono quasi interamente le due sommità e gran parte delle pendici del colle. le più antiche carte di roma e le stampe a volo d’uccello non lasciano dubbi sulla forte densità di abitazioni esistenti attorno al colle (fig. 3). parallelamente agli interventi di edilizia pubblica, continua lo sviluppo dell’edilizia privata che interessa le pendici e si protrae fino alle soglie del ‘900. le foto dei primi del 900 e i rilievi d’archivio relativi alla realizzazione del vittoriano indicano chiaramente che alla fine dell’800 e nel primo quarto del 900 il campidoglio è completamente coperto da costruzioni anche sui versanti (fig. 4). geologia, idrogeologia e ... fig. 4 immagini del campidoglio prima delle demolizioni per la costruzione del vittoriano, 1884. arch. convento dell’ara coeli (da di paola, 1986). images of the capitoline hill before the demolitions to build the "vittoriano" in 1884 (from di paola, 1986). 418 i quartieri abitativi sorti sulle pendici settentrionali del colle vengono abbattuti quasi completamente con gli ultimi rilevanti interventi edilizi: la realizzazione del monumento a vittorio emanuele ii (il vittoriano) inaugurato nel 1911, e per la realizzazione di via dell’impero e per gli scavi archeologici dei fori (anni ‘30) con il totale isolamento urbanistico del campidoglio. nuovi edifici amministrativi sorgono sul colle e sulle vie adiacenti, viene allargata piazza della consolazione e il vicus jugarius sui quali sorgono altri edifici. con questi atti cessa l’attività distruttiva e costruttiva sulle sue pendici e sulle sommità del colle. oggi solo gli archeologi continuano a scavare e a portare a giorno monumenti e, sotto di essi, tracce del suolo vergine dell’area. 4. geologia 4.1 geologia dell’area romana la geologia dell'area romana è caratterizzata da un assetto stratigrafico estremamente complesso, derivante dal succedersi di una lunga serie di eventi tettonici, vulcanici e climatici che hanno controllato l’evoluzione di questa regione. il ruolo importante che tutti questi fattori hanno giocato è stato riconosciuto in una serie di lavori recenti, che attraverso l’impiego di metodi multidisciplinari quali datazioni radiometriche e paleomagnetismo, hanno ricostruito la geocronologia degli eventi sedimentari, legandoli alle fluttuazioni del livello del mare indotte dall’alternarsi dei periodi glaciali ed interglaciali, e vincolandoli alla parallela storia eruttiva dei vulcani romani. in questo lavoro si farà pertanto riferimento ad una stratigrafia aggiornata sulla base di numerose datazioni assolute e sviluppata sul concetto di correlazione tra cicli erosivi e cicli sedimentari con i periodi glaciali ed interglaciali (marra & rosa, 1995; karner & renne, 1998; karner & marra, 1998; marra et alii, 1998; karner et alii, 2001 a; karner et alii, 2001 b). i caratteri così particolari che hanno fatto dell’area romana un luogo in continua trasformazione risiedono nel fatto di essere posta vicino a una zona costiera, alla foce di un grande corso d'acqua (il tevere) con un delta in continua evoluzione nel corso dell’ultimo milione di anni, e, contemporaneamente, di essere stata sede della nascita e dello sviluppo di due grandi distretti vulcanici (gli albani e i sabatini, fornaseri et alii, 1963; mattias & ventriglia, 1970; de rita et alii, 1988; de rita et alii, 1993), caratterizzati da una prolungata e intensa attività eruttiva. la prossimità alla costa tirrenica ha determinato nell’area un significativo risentimento degli effetti delle variazioni glacio-eustatiche, con l’effetto di produrre una sedimentazione discontinua, secondo cicli regolari, con periodicità di circa 100.000 anni. i depositi di questi cicli sedimentari sono rappresentati da successioni a gradazione diretta, con ghiaie alla base che passano verso l’alto a sabbie e argille, che si depongono a colmamento delle incisioni fluviali e della piana costiera durante la risalita del livello del mare (“sezioni aggradazionali”, karner & marra, 1998). la datazione col metodo 40ar/39ar di numerosi livelli piroclastici eruttati dai distretti vulcanici sabatino e albano, intercalati all'interno di queste successioni sedimentarie (fig. 5), ha permesso di correlarle con i cicli glaciali (fig. 6), superando notevoli difficoltà di interpretazione e attribuzione. nel corso degli anni la letteratura geologica ha infatti attribuito nomi diversi ai cicli sedimentari (nomi che corria. corazza, l. lombardi & f. marra fig. 5 correlazione tra gli stadi isotopici (da bassinot et al., 1994), le successioni sedimentarie e alcune delle formazioni vulcaniche dell’area romana. correlation sketch for the marine isotopic stages (from bassinot et alii 1994) with the sedimentary and volcanic units in the area of rome. spondono in genere alle località dove questi cicli sono stati riconosciuti e studiati), ma la loro distinzione e la loro correlazione spaziale è sempre rimasta estremamente problematica, stanti la similitudine dei diversi depositi e la mancanza di elementi oggettivi di identificazione (si veda marra & rosa, 1995, e karner & marra, 1998, per una completa bibliografia). una nuova denominazione dei cicli sedimentari legati alle oscillazioni eustatiche è stata proposta recentemente (giordano et alii, 2003) nel difficile tentativo di formalizzare la stratigrafia per l'area romana. correlazione tra le successioni sedimentarie dell’area romana e gli stadi isotopici, determinata in base all’età dei livelli piroclastici intercalati al loro interno, e sulla base dei rapporti stratigrafici con le principali ignimbriti eruttate dai vulcani romani, anch’esse riportate sulla curva isotopica con le loro età radiometriche (in ka). esempio di "sezione aggradazionale" e sua correlazione con la curva isotopica dell'ossigeno. la "formazione di san paolo" (marra & rosa, 1995) è stata vincolata allo stage 11 sulla base dell'età di quattro diversi prodotti vulcanici (karner & marra, 1998; karner et alii, 2001 b): il livello piroclastico inferiore, depostosi proprio al tetto della porzione ghiaiosa basale, permette di verificare infatti che la porzione più grossolana della successione si è deposta in un’ epoca prossima al low stand, quando il livello del mare si era molto abbassato, in corrispondenza del massimo glaciale (stage 12). le età degli altri tre livelli piroclastici testimoniano come il resto della sequenza, a carattere più fine, si sia deposta durante la fase di risalita del mare, che è culminata con il periodo interglaciale (high stand) correlato allo stage 11. in fig. 7 è riportata una sezione schematica (non in scala) mostrante l’assetto stratigrafico dell’area centrale di roma. i terreni più antichi presenti nella città di roma sono le argille dell’unità del monte vaticano (corrispondenti in parte alle “marne vaticane” e/o alle “argille azzurre” degli autori), le quali costituiscono quello che possiamo considerare per molti aspetti il substrato geologico dell’intera area (marra et alii, 1995). queste argille sono osservabili in affioramento solo lungo i versanti orientali di monte mario, ai piedi della collina del pincio e lungo il versante sud-orientale di monte verde, laddove i movimenti tettonici che hanno contribuito all’evoluzione geologica dell’area hanno sollevato le serie argillose, esponendole alla vista. si tratta di sedimenti marini che cominciarono a deporsi nel pliocene, circa 4,5 milioni di anni or sono, quando tutta l’area romana era sommersa dalle acque, e hanno continuato ad accumularsi sui fondali del mare, la cui profondità andava riducendosi progressivamente, durante il pleistocene inferiore, circa 1,8 milioni di anni fa (bergamini et alii, 2000). ad essi fanno seguito sedimenti sabbiosi di ambiente marino litorale, noti con il nome di unità di monte mario (conato et alii, 1980, bergamini et alii, 2000) che si depongono fino a circa un milione di anni or sono. a partire da circa 900.000 anni fa, l’inizio del cosiddetto “pleistocene glaciale” ha fatto si che in questa zona, divenuta oramai un’area di costa, si facessero sentire gli effetti delle oscillazioni del livello del mare dovute al verificarsi delle glaciazioni (karner et alii, 2001 b). nelle fasi interglaciali, con la risalita del livello marino, nell’entroterra si è verificata la deposizione di terreni continentali ad opera dei corsi d’acqua precursori dell’attuale tevere (paleotevere). si deposero così varie successioni di ghiaie, sabbie ed argille, dapprima in ambienti costieri e, successivamente, a seguito di un generale sollevamento dell’area, concomitante con l’inizio dell’attività parossistica dei vulcani, in ambienti fluvio-palustri (karner & marra, 1998). nell’area della città di roma le successioni marine del pleistocene inferiore (unità di monte mario e parte dell’unità del monte vaticano) sono state erose e sul substrato argilloso plio-pleistocenico poggiano le ghiaie basali delle successioni fluvio lacustri del paleotevere (marra & rosa, 1995). in particolare, i quattro cicli precedenti l’inizio dell’attività vulcanica a carattere parossistico (tra 900 e 600 ka) vengono raggruppati in questo lavoro nella formazione del paleotevere. le successioni legate a questi cicli hanno rapporti stratigrafici complessi perché, in assenza di movimenti verticali legati alla tettoni419geologia, idrogeologia e ... fig. 6 principio di correlazione tra le sequenze sedimentarie dell’area romana ed i periodi glaciali ed interglaciali. principle of correlation between the sedimentary succession of the rome area and the glacial and interglacial stages. ca, i diversi cicli sedimentari connessi alle oscillazioni glacio-eustatiche si depongono lateralmente uno rispetto all’altro, seguendo la migrazione degli assi fluviali e andando a riempire le incisioni che si creano durante la fase erosiva entro i terreni precedentemente depostisi. nel centro storico di roma, in particolare, si rinviene la formazione del paleotevere ii (= paleotevere 2a, marra & rosa, 1995), costituita da un orizzonte di 420 a. corazza, l. lombardi & f. marra fig. 7 sezione schematica (non in scala) mostrante l’assetto stratigrafico de centro storico di roma. sketch of the stratigraphic setting in the historic centre of rome. circa 10 metri di ghiaie che passano verso l’alto a sabbie e argille grigie lacustri, depostesi durante la risalita del mare nello stage 19 (karner et alii, 2001 b). questa unità corrisponde, nell'area ove si trovava il delta del paleotevere, all' unità di ponte galeria 1 (marra et alii, 1998). al tetto delle argille grigie è presente una superficie di erosione al di sopra della quale si sono deposti dei limi e delle sabbie contenenti livelletti di ghiaia, caratterizzati dalla presenza di abbondanti concrezioni travertinose. tali depositi (formazione del paleotevere iii = paleotevere 2b, marra & rosa, 1995) costituiscono la porzione più interna del successivo ciclo sedimentario, correlato con lo stage 17 e corrispondente alla formazione di ponte galeria 2 (marra et alii, 1998). rispetto ai quattro cicli descritti, nel centro storico di roma non si rinviene quello più giovane (paleotevere iv) correlato con lo stage 15 (formazione di santa cecilia, karner & marra, 1998) poiché i depositi associati con esso si sono deposti nelle zone più costiere a sud della città. diversamente, la successione di ghiaie, sabbie e argille correlabile al ciclo più antico del paleotevere (formazione di monte ciocci, karner et alii, 2001 b), è presente solo in destra idrografica del tevere, sollevata dalla tettonica ad oltre 50 metri s.l.m. e completamente erosa ad est della valle. dopo la deposizione della formazione di santa cecilia avviene un profondo cambiamento paleogeografico determinato da un importante sollevamento regionale, in concomitanza con l’inizio dell’attività parossistica dei vulcani laziali (karner & marra, 1998). questo sollevamento provoca la progradazione del delta del tevere verso sud-ovest, e nell’area di ponte galeria, prima coincidente con la piana costiera, si depositano corpi sedimentari di limitata estensione laterale che colmano le profonde incisioni vallive scavate dal tevere e dai suoi affluenti durante i periodi glaciali. si depongono così quattro successioni aggradazionali, corrispondenti alle terminazioni glaciali associate agli stages 13, 11, 9 e 7, prima che un nuovo forte sollevamento determini una nuova progradazione del delta del tevere. tali sequenze sedimentarie sono state descritte in letteratura (marra & rosa, 1995) con i nomi, rispettivamente, di formazione di valle giulia, formazione di san paolo (= p.p. al san cosimato sensu latu conato et alii, 1980), formazione aurelia e formazione di vitinia (conato et alii, 1980). le ultime tre formazioni sono state rinominate da giordano et alii (2003): "sintema del torrino", sintema di quartaccio" e "sintema di campo selva", rispettivamente. un criterio che facilita il riconoscimento di questi cicli, che altrimenti presentano caratteri sedimentologici molto simili tra loro, è la loro posizione stratigrafica rispetto ai livelli vulcanici e/o alle vulcaniti rimaneggiate. i prodotti vulcanici più antichi (tufo pisolitico di trigoria, 561±1 ka; tufo giallo della via tiberina, unità inferiore e superiore, 561±1 e 548±4 ka) sono stati eruttati alla fine dello stage 15, poco dopo la massima risalita del livello del mare associata con quella terminazione glaciale. essi sono stati successivamente erosi durante la regressione culminante nel low stand dello stage 14. quasi al culmine di questa fase erosiva si depongono il tufo del palatino (528±1 ka) proveniente dai colli albani e il tufo giallo di prima porta (514±3 ka), immediatamente seguito dalla sequenza piroclastica di grottarossa (514±5 ka), dai sabatini (karner et alii, 2001 a). durante la successiva fase di risalita del livello del mare si depone la formazione di valle giulia (stage 13). essa è pertanto successiva alla deposizione di tutti questi tufi e colma le paleoincisioni scavate durante il low stand dello stage 14 . alcune delle principali ignimbriti albane e sabatine, in particolare, sono state eruttate in corrispondenza dei low stands: il tufo rosso a scorie nere (449±1 ka), sabatino, e le pozzolane rosse (457±4 ka), albane, sono stati eruttati in corrispondenza del low stand tra lo stage 13 e l’11. la formazione di san paolo quindi, che corrisponde allo stage 11, contiene prodotti rimaneggiati di queste ignimbriti ma è sottostante al tufo lionato (366±4 ka) che è stato eruttato in corrispondenza del successivo low stand (stage 10). quest’ultimo riempie caratteristicamente le paleovalli incise durante il periodo glaciale ed è ricoperto dai depositi del successivo high stand: la formazione aurelia (stage 9). a differenza dei depositi corrispondenti alle formazioni di valle giulia, san paolo e aurelia, i depositi della formazione di vitinia non sono stati identificati all’interno della valle del tevere, ma sono stati ampiamente riconosciuti (e datati) a ponte galeria. l’assenza della formazione di vitinia a roma è probabilmente legata all’intensa erosione che hanno subito i suoi depositi ad opera del tevere e dei suoi affluenti, poichè immediatamente dopo la sua deposizione ha avuto luogo una terza fase di uplift, proseguita fino al limite dell’olocene, che ha sollevato di oltre quaranta metri l’area romana. un’ipotesi alternativa è che parte dei depositi attribuiti alla formazione aurelia facciano parte in realtà della formazione di vitinia, e che la mancanza di marker geocronologici più recenti del tufo lionato non consenta di riconoscerli come tali. un'interpretazione diversa della stratigrafia relativa a questi due cicli sedimentari e data in giordano et alii (2003), tuttavia essa è in conflitto con la presenza di materiali piroclastici datati 251±8 (karner & marra, 1998) all'interno della formazione di vitinia in località quartaccio, proposta da questi autori come località tipo per rinominare la formazione aurelia in, appunto, sintema di quartaccio. allo stesso modo, non si rinvengono a roma i depositi fluviali associati al ciclo tirreniano (stage 5), ad eccezione di una segnalazione lungo la valle dell’aniene (saccopastore, blanc, 1939; de angelis d’ossat, 1930; segre 1948 a; 1948 b). i depositi di costa associati allo stage 7 e al 5 sono tuttavia ben noti, e formano degli evidenti terrazzi marini alle quote di 40 e 20 m s.l.m. lungo la costa tirrenica (hearty & dai pra, 1986; bordoni & valensise, 1998; sorgi, 1994, giordano et alii, 2003). l'ultima fase erosiva è quella legata alla massima regressione marina dell’ultimo periodo glaciale würmiano, avvenuta circa 18.000 anni fa. come conseguenza del forte sollevamento avvenuto fino a tutto i l tirreniano, nell’area urbana l'azione erosiva del tevere sovrascava rispetto al livello di base dei depositi precedenti, e arriva ad incidere il substrato pliocenico fino alla profondità di -50 metri s.l.m. tutto il reticolo idrografico afferente al fiume si approfondisce significativamente e si originano ampie e profonde valli che, in coincidenza con l’ultima terminazione glaciale (circa 421geologia, idrogeologia e ... 13.000 anni fa), vengono progressivamente ricolmate dai depositi alluvionali del tevere e dei suoi affluenti, come effetto dell’ultima risalita del livello del mare che raggiunge il suo livello attuale circa 5.000 anni or sono. 5. geomorfologia del campidoglio 5.1 la morfologia originaria il colle capitolino mostrava due sommità separate da una zona depressa posta all’incirca dove è localizzata la piazza attuale. la figura 8 mostra la ricostruzione della morfologia del colle come si presenta sotto la coltre dei terreni di riporto, con isoipse tracciate ogni 5 metri. la superficie rappresentata è sì relativa ai soli terreni geologici ma non può essere considerata quella originaria in quanto anch’essa è risultato degli interventi umani protrattisi per oltre duemila anni. il colle capitolino, geologicamente costituito da una successione di terreni teneri nella porzione sommitale poggiati su terreni lapidei, molto consistenti e di elevato spessore, mostra le pareti dei rilievi a pendenze molto forti. la sella che separa le due sommità potrebbe essere, come vedremo in seguito, il risultato di attività di escavo del tufo e solo in parte dovuta all’erosione delle acque di superficie in un piccolo impluvio che ha il suo spartiacque in corrispondenza del limite meridionale della depressione. alla base del colle, tranne che nel versante occidentale, sono presenti formazioni sedimentarie tenere e erodibili. sul lato nord e sul lato sud due corsi d’acqua, il tevere e lo spinon rispettivamente, lambivano il rilievo. la collina attualmente si mostra di forma è trapezoidale, con i lati lunghi (circa 500 m) orientati circa nord est sud ovest e i lati corti (circa 200 m) orientati in senso nord-ovest sudest. ancora oggi, nonostante le modifiche dell’uomo, sono ben evidenti le due sommità: il capitolium (m 45 s.l.m.) e l’arx (m 47 s.l.m.) separate da una sella, l’asylum, che raggiunge attualmente i 38 m s.l.m. già nell’800 alcuni autori, tra gli altri il brocchi (1820), si erano impegnati nel ricostruire la morfologia del colle. in epoca recente si hanno altre ricostruzioni tra le quali la più recente è quella di alvarez et alii (1996). tra l’asylum e la piana del tevere la pendenza è molto dolce così come è dolce la morfologia dei rilievi sommitali fino ai cigli, oltre i quali le pendici scendono bruscamente con pareti subverticali fino alle zone pianeggianti che le circondano. queste ultime hanno quote medie minime, attuali, di circa 26 m s.l.m. in p. dell’ara coeli, tra i 19 e i 14 m nei fori e tra i 16 m e i 17 m in via del t. marcello. le quote più basse, si rinvengono nel foro di cesare, ma sono imputabili agli scavi condotti in epoca romana per spianare l’area. diversamente da tutta l’area di studio le quote originarie di questa zona erano di alcuni metri più alte di quelle attuali. l’assetto morfologico che noi riusciamo a ricostruire, sotto la copertura stratificata di ruderi, scarichi ed edifici antichi e moderni, è il risultato della storia geologica dell’ultimo milione di anni e del continuo intervento umano. ma è l’ultimo glaciale che ha dato al colle il contributo sostanziale per il raggiungimento della sua forma attuale. il letto del tevere, infatti, circa 18.000 anni or sono, raggiunse, a roma, la quota di 50 metri sotto il livello marino attuale (corazza & lombardi, 1995, p. 188) e i fossi in esso affluenti si abbassarono in modo proporzionale, anche se le loro pendenze non sono uniformi e mostrano nei tratti di confluenza con il tevere inclinazioni più elevate che nei tratti distali. l’assetto morfologico della regione si modificò, con una accentuazione delle valli e delle colline, tra le quali quella del campidoglio. la risalita del livello marino comportò il colmamento delle valli, il cui riempimento si attenuò drasticamente nel 3.000 circa a.c., per recuperare poi lentamente gli ultimi decimetri raggiungendo il livello attuale (marra & rosa, 1995, p. 110). il campidoglio, ubicato tra la valle del tevere e quella dello spinon è un caratteristico esempio di come l’erosione fluviale ha giocato un ruolo fondamentale nell’area romana. lo scalzamento dei terreni teneri presenti al piede del rilievo lasciava in aggetto porzioni di tufi rigidi e fratturati che crollavano lasciando di nuovo le pareti verticali soggette a fenomeni di instabilità dovuti all’erosione al piede. di questi eventi sono state trovate le tracce in un sondaggio di fronte al vittoriano ove, alla profondità di m 60, entro strati di limi e argille, attribuibili alle alluvioni del tevere, è stato rinvenuto un blocco di tufo litoide inglobato nei limi alluvionali. tale blocco, di una roccia molto più antica delle alluvioni, e in origine in posizione di affioramento molto più elevata della quota di rinvenimento, non può che essere crollato dalla parete tufacea durante la risalita del livello marino e quindi del letto del fiume. di maggiore interesse, perchè più vicine ai nostri giorni, sono le frane storiche di cui sono state rinvenute le testimonianze negli scavi condotti al piede del rilievo. lanciani (1985, p. 264) cita uno scritto di flaminio vacca: “...... sopra il monte tarpeo dietro il palazzo dei conservatori, verso il carcere tulliano, so essere scavati molti pilastri di marmo statuale... (attualmente) non si trovano ne cornicioni ne altri segni di detto tempio onde io fo giudizio che per essere tanto accosto alla ripa di detto monte, si siano dirupati da loro stessi”. la testimonianza di f. vacca è confermata da ritrovamenti citati sempre da lanciani (1985, p. 264). “nel 1780 grossi frammenti di trabeazioni ornati di bucrani e festoni vennero scavati nelle fondamenta del n° 13 di via montanara, al piede del campidoglio; similmente altri frammenti al n° 33 di via della consolazione, nel 1875. anche le dediche (in marmo) dei re orientali di cui abbiamo parlato prima furono trovate in fondo al pendio sotto casa moroni, in piazza della consolazione, nel 1877”. dell’instabilità del colle parla anche coarelli (1995, p. 43) quando afferma che del piazzale che si estendeva davanti al tempio della fides restano poche tracce in quanto “le continue frane....., fin dall'antichità, hanno interessato questa parte del campidoglio e ne hanno fatto scomparire gran parte ". e inoltre che “i resti dell’edificio del tempio della fides, precipitati dalla sommità del colle in seguito ad una frana, sono forse 422 a. corazza, l. lombardi & f. marra 423geologia, idrogeologia e ... fig. 8 ricostruzione della morfologia del colle sotto i terreni di riporto. legenda a) isoipse del substrato geologico (in metri s.l.m.); b) scarpate, naturali o artificiali, nel substrato geologico. reconstruction of the geomorphology of the capitoline hill. legend: a) contour lines of the surface of the geologic substrate in metres above sea level; b) natural or artificial (quarry and other excavation) scarps. da riconoscere in quelli scoperti nei pressi della chiesa di sant’omobono, si tratta di parte del podio in opera cementizia, di frammenti di colonne di travertino, e di una grande testa marmorea femminile”. altri frammenti riferibili a crolli dal colle sono quelli relativi a “pezzi di un basamento di marmo nero con vittorie, trofei e armi in rilievo, riferibili al basamento del gruppo bronzeo donato dal re bocco di mauretania, che riproduceva la scena della consegna di giugurta a silla” (coarelli, 1995, p. 44), rinvenuto nell’area di sant’omobono. anche le attività di escavazione di materiali da costruzione hanno inciso sulle caratteristiche morfologiche del colle. possiamo ipotizzare che i tufi che affioravano sui versanti del colle siano stati utilizzati fin dai primi insediamenti umani dell’area. i vasti affioramenti di tufo lionato rosso litoide (tufo dell’aniene o di monte verde, secondo la terminologia archeologica), quelli del tufo del palatino (cappellaccio degli archeologi) e i tufi granulari (tufo giallo di prima porta) presenti alla base del rilievo, ma anche le intercalazioni vulcaniche nella formazione di s. paolo, affioranti nel foro di cesare, sono materiali dei quali erano ben note le qualità in epoca romana. le numerose cavità osservabili (vedi capitolo relativo agli ipogei), indicano una vasta e continua attività di scavo. attività che è continuata certamente nel medio evo, e fino al 1500, come risulta da dati di archivio. sul lato di via del teatro marcello e di via della consolazione le pareti verticali di tufo, che lasciano intuire ancora i piani di taglio per ricavarne blocchi, e in molti punti mostrano evidenti tracce degli scalpelli e dei picconi, sono certamente da attribuirsi all’opera dell’uomo. le pendici lungo questi lati erano certamente meno acclivi e presumibilmente colme dei detriti di falda derivanti dal progressivo arretrare delle pareti. sul lato orientale i segni delle escavazioni sono stati obliterati dai muri di sostegno realizzati negli anni trenta e dalla costruzione del vittoriano. restano comunque anche su questo lato le notizie delle numerose gallerie di cava incontrate durante i lavori per la realizzazione del monumento a vittorio emanuele. e’ molto probabile che una delle cause delle frequenti frane, avvenute in epoca storica, sia da ricercare anche nelle cavità sotterranee le cui volte, per il tempo e per i carichi degli edifici, possono aver ceduto e fatto crollare le strutture soprastanti. per quanto si riferisce alla storia antropica del campidoglio, tralasciando l’attività di cava, abbiamo visto che il colle è stato oggetto di un intenso e continuo sviluppo urbanistico, che ha comportato frequenti tagli per la realizzazione di terrazzamenti e di muri di contenimento e di difesa e la costruzione di numerosi edifici che, in caso di distruzione, venivano lasciati sul posto e usati come appoggio per le fondazioni di nuovi edifici. e’ impossibile stabilire l’entità degli interventi antropici per cui la ricostruzione proposta nella fig. 8 non rappresenta la morfologia originaria ma ha tentato di fotografare l’assetto morfologico quale risultato di tutte le attività antropiche e naturali degli ultimi millenni. il nostro lavoro, pur tenendo conto delle diverse ricostruzioni effettuate da autori precedenti, nella sostanza e nella forma è completamente nuovo in quanto è il risultato di un accurato esame delle stratigrafie delle perforazioni nelle quali lo strato dei riporti è quasi sempre perfettamente leggibile. inoltre sono stati utilizzati i dati emersi dallo scavo per il vittoriano, antiche stampe e vecchie foto. gli elementi raccolti sono stati sovrapposti alla base topografica attuale dell’area, rilievo alla scala 1:500, e a singole misurazioni di quota realizzate sul terreno per coprire zone prive di informazioni. infine sono stati utilizzati tutti gli affioramenti geologici rilevati sul terreno e quelli citati in bibliografia. tali affioramenti rappresentano punti fermi della superficie topografica reale. malgrado le approssimazioni cui siamo stati costretti, possiamo ritenere che la restituzione, esposta un fig. 8, rappresenti un’immagine del colle abbastanza simile a quella che si presentava agli occhi dei primi abitanti dell’area. dall’esame della carta, emergono alcuni dettagli di un certo interesse: a) molto evidenti sono le due sommità del campidoglio, il capitolium (quota max rilevata sotto i riporti: 43,40 m s.l.m.) e l’arx (quota max rilevata sotto i riporti: 48,90 m s.l.m.) che appaiono, ancora oggi, con pareti molto acclivi su tutti i lati. b) chiaramente distinguibile è anche la sella dell’asylum (quota max rilevata sotto i riporti: 33,85 m s.l.m.), caratterizzata da due versanti asimmetrici: uno con pendenza dolce verso la valle del tevere, mentre l’altro, subito dopo lo spartiacque, mostra pendenza molto ripida verso il foro. la modesta depressione dell’asylum è separata dalle due sommità dell’arx e del capitolium da versanti a forte pendenza, con aspetto di vere e proprie pareti. questo elemento e la forma stessa della depressione lasciano perplessi sulla naturalità della morfologia rilevata. si può ipotizzare che le due pareti che delimitano la valle, nelle quali peraltro sono stati incontrati accessi a gallerie, siano residui di fronti di cava e che tutta la valle sia stata oggetto, in antico, di escavazione del tufo. alcune stampe antiche mostrano in effetti pareti verticali tipiche degli affioramenti del tufo litoide. nella stampa di totti (1638) si osserva chiaramente la parete di tufo ai piedi della basilica dell’ara coeli (fig. 9). c) anche sul lato orientale del colle, nel foro, si nota un’ampia depressione su cui sorge il tabularium. tale depressione è quasi certamente attribuibile ad attività antropica. lungo il suo margine sono ancora osservabili le tracce dello scavo del cappellaccio, del tufo giallo di prima porta e del tufo lionato (fig. 10). si deve pertanto ritenere che i monumenti che si appoggiano al versante prospiciente il foro siano localizzati, almeno in parte, sul piano di una antica cava e siano stati appoggiati contro le pareti di questa ultima. d) malgrado le trasformazioni realizzate in antico la ricostruzione mostra nettamente la sella che congiungeva il campidoglio al quirinale. la sella è perfettamente leggibile anche se le quote del terreno vergine sono solo di pochi metri più alte delle quote attuali delle due zone pianeggianti, corrispondenti alle piane alluvionali del tevere e dello spinon. i terreni vergini in corrispondenza della sella si rinvengono a quote medie di 13 metri s.l.m.. prima degli 424 a. corazza, l. lombardi & f. marra interventi di scavo di cesare e traiano le quote minime del terreno vergine nella sella dovevano essere invece sempre superiori ai 16 metri s.l.m.. e) le alluvioni delle due piane del tevere e dello spinon, sotto i terreni di riporto, hanno quote tra 6 e 8 m s.l.m.. 5.2 geologia del campidoglio (tav. 1) la prima rappresentazione della geologia romana, e con essa quella del campidoglio, risale al 1820 (brocchi, 1820). da quel momento l’interesse per la geologia e per la struttura geologica delle colline romane riscuote l’interesse di studiosi e ricercatori. ponzi (1858, 1872), portis (1893, 1905, 1910), clerici (1893), verri (1909, 1915, 1920), de angelis d’ossat (1931, 1932, 1940, 1942, 1943, 1944), ventriglia (1971, 2003), marra & rosa (1995), alvarez et alii (1996), ammermann (1990, 1992, 1996), ammerman & terrenato (1996) e sappa & pasquini (1997, 1998) pubblicano differenti versioni dell’interpretazione geologica del campidoglio. nella tavola 1 (carta geologica) e nella figura 11 (sezioni geologiche) viene fornita una nuova interpretazione del colle capitolino e dei suoi immediati dintorni, tramite la rappresentazione di una geologia più complessa rispetto a quella nota in letteratura, con più unità e formazioni stratigrafiche. per ognuno dei termini stratigrafici viene dato (tra parentesi) anche il termine utilizzato in letteratura dagli autori che si sono occupati della geologia del campidoglio. successione sedimentaria prevulcanica unità di monte vaticano (argille azzurre, argille plioceniche, marne vaticane). argille grigio azzurre, talora con intercalazioni sabbiose, non affioranti, ma raggiunte da numerose perforazioni sia nelle valli che circondano il colle, che nella stessa collina. età: pliocene superiore pleistocene inferiore (4500-1200 ka). formazione del paleotevere (maremmano, siciliano, fluvio-palustre, ponte galeria). formata da ghiaie e sabbie, non affiora attualmente ma era visibile, prima della obliterazione causata dai riporti, nella parte meridionale della collina; è stata raggiunta con varie perforazioni al di sotto delle serie vulcaniche. età: pleistocene medio, (870-600 ka, stages 21-19-17-15). successione vulcanica e sedimentaria sin e post vulcanica tufo del palatino (cappellaccio degli archeologi, parte dei tufi antichi degli autori, anche noto come tufo granulare tipico). piroclastite scoriacea, massiva e prevalentemente litoide, di colore grigio-scuro, contenente successioni sedimentarie (ghiaia) intercalate a livelli sedimentari con elementi vulcanici rimaneggiati. età: pleistocene medio (528±1 ka, stage 14). tufo giallo di prima porta3; sequenza piroclastica di grottarossa (unità vulcaniche recentemente introdotte in letteratura, provenienti dall’apparato vulcanico sabatino, precedentemente classificate in vario modo, principalmente col termine generico di tufi antichi). si tratta di vulcaniti di colore da grigio-chiaro a giallastro, semicoerenti, a volte litoidi, spesso a carattere pozzolanaceo o cineritico, caratterizzate dalla pre425geologia, idrogeologia e ... fig. 9 incisione di b. totti (1638), gabinetto comunale delle stampe. lithography by b. totti, 1638 (gabinetto comunale delle stampe). fig. 10 piazza della consolazione. affioramento di tufo giallo di prima porta con tracce di tagli di cava. piazza (square) della consolazione, outcrop of tufo giallo di prima porta affected by quarry cuttings. 3 poco si è riflettuto sulla presenza, nella città di roma, di un tufo giallo, analogo a quello della via tiberina, ma di 50.000 anni più giovane e con caratteristiche tecniche peggiori del tufo giallo classico (grotta oscura degli archeologi). tale tufo giallo era disponibile nella città come dimostra la cava osservata da lanciani nel colle aventino (lanciani, 1985) e gli affioramenti osservabili a porta cavalleggeri, in viale tiziano, alla base del palatino (horrea agrippae) e in piazza della consolazione. le c.d. mura serviane sono costruite quasi interamente con un tufo giallo di grotta oscura, cavato lungo la via tiberina e disponibile per i romani dopo la conquista di veio (396 a.c.). per una parte delle mura e per altri edifici potrebbero essere stati utilizzati i tufi gialli disponibili all’interno della città, per cui le murature potrebbero avere un’età più antica di quella fino ad oggi attribuita. 426 a. corazza, l. lombardi & f. marra tav. 1 carta geologica geological map alluvioni recenti del fiume tevere e della valle dello spinon. argille, limi e sabbie, livelli di argille torbose. formazione aurelia. argille grigie e biancastre, sabbie e limi travertinosi, presenza di materiale vulcanico rimaneggiato. tufo lionato. piroclastite massiva, di colore rosso fulvo, tenace, lapidea e fessurata. formazione san paolo. argille verdastre e giallastre, limi e sabbie con lenti di materiale vulcanico rimaneggiato. sequenza di vulcaniti e prodotti del loro rimaneggiamento. le vulcaniti derivano dall’attività dei distretti vulcanici albano e sabatino. tufo del palatino: piroclastite di colore grigio scuro, compatta ma fissile con inclusi sedimentari e vulcanici, simile al peperino, nota come cappellaccio. tufo giallo di prima nota: piroclastite di colore grigio scuro e giallastro, debolmente cementata. la sua facies litoide è simile al tufo giallo della via tiberina (tufo di grotta oscura). recent alluvium of the tiber river and its tributary spinon. clay, silt and sand with peat levels. aurelia formation. grey and whitish clay, sand and silt with travertine layers, characterised by the presence of reworked volcanic material tufo lionato. massive pyroclastic-flow deposit, lithified and fractured, orange in color. san paolo formation. greenish and yellowish clay, silt and sand with lenses of reworked volcanic material. sequence of pyroclastic deposits erupted from the sabatini mounts and the alban hills, and the products of their reworking. tufo del palatino: massive pyroclastic-flow deposit, lithified and characterised by horizontal cleavage, with sedimentary and volcanic lithics, dark grey in color, also known as "cappellaccio". tufo giallo di prima porta: massive pyroclastic-flow deposit, poorly lithified, pale green to yellowish in color, its litified facies is similar to the tufo giallo della via tiberina (also known as tufo di grotta oscura) formazione del paleotevere ii. argille, limi, sabbie e ghiaie di origine continentale. affiorante sotto i riporti nellle carte cartografiche paleotiber formation. fluvial-to-lacustrine gravel, sand and clay. it crops out below the anthropic fill in the mapped area. traccia di sezione fons servilli tullianun senza di livelli ben laminati. età: pleistocene medio (514±3, 514±5 ka, stage 14). nella fig. 12 si può osservare il tufo giallo di prima porta sottoposto al tufo lionato formazione di san paolo (nuova unità stratigrafica al campidoglio interpretata precedentemente come siciliano o maremmano e, per le porzioni vulcaniche, identificata, a volte, con le pozzolane). costituita da argille siltose giallastre, con fossili dulcicoli, da argille grigie e da livelli di piroclastiti rimaneggiate ricche in pomici. queste ultime hanno fornito un’età radiometrica di 416±6ka (alvarez et alii, 1996). le figure 12 e 13 mostrano i rapporti tra i vari orizzonti tufacei e sedimentari in via della consolazione e nella piazza omonima. era visibile anche negli scavi a suo tempo eseguiti per la realizzazione del vittoriano e lungo la via della consolazione. età: pleistocene medio (434-406 ka. stage 11). la formazione affiora sul lato orientale del colle, sulle pareti occidentali del foro di cesare, sul piano dello stesso foro, negli scavi del carcere mamertino (fig. 14). 427geologia, idrogeologia e ... fig. 11 sezioni geologiche. geologic cross-sections (see tavola 1 for location). fig. 12 panoramica dell’affioramento di piazza della consolazione. outcrops along the south eastern side of the capitoline hil, via della consolazione. tufo lionato (tufo rosso litoide, tufo di monte verde o dell’aniene degli archeologi. tufo litoide non stratificato, di colore rosso-fulvo, ricco di scorie, a volte si presenta non compatto fino ad assumere carattere di pozzolana. tali caratteri sono stati riscontrati, prevalentemente nella porzione superiore del banco, soprattutto nella zona settentrionale della collina (si vedano le sezioni in portis, 1893, in de angelis d’ossat, 1932 e in giuntini, 1954). affiora lungo il perimetro del colle, sovrapposto alla formazione di san paolo (fig. 15) ed è rappresentato da un grande banco a spessore crescente da oriente verso occidente. nelle porzioni nord orientale e sud orientale è assente. età: pleistocene medio (355±2ka. stage 10). formazione aurelia (fluvio lacustre degli autori). costituita da argille e limi, sabbiosi alla base, contenenti concrezioni calcaree biancastre, affiorante sul bordo delle pareti del fronte meridionale del campidoglio (fig. 16), lungo via della consolazione, e sulla sommità del colle ove è stata messa a giorno con gli scavi per il tempio di giove (fig. 17). sul lato orientale è stata messa in luce con gli scavi per il vittoriano. età: pleistocene medio (340-328 ka. stage 9). 428 a. corazza, l. lombardi & f. marra fig. 13 panoramica dell’affioramento di via della consolazione . south-western continuation of the outcrops in fig. 12, showing the sedimentary deposit of the san paolo formation embedded between the tufo del palatino and tufo lionato volcanic units. fig. 14 affioramento della formazione di san paolo (fsp) nel foro di cesare. outcrop of san paolo formation in the forum of caesar. fig 15 via della consolazione. tufo lionato (tl) sovrapposto a sedimenti della formazione di san paolo (fsp). via della consolazione, tufo lionato overlying the sedimentary deposit of the san paolo formation. alluvioni recenti. depositi prevalentemente limoargillosi, con intercalazioni e lenti sabbiose, caratterizzati alla base da orizzonti ghiaiosi. colmano la valle del tevere, a piazza venezia, la valle del velabro nel foro romano e nel suo prolungamento verso via del teatro marcello. non affiorano ma sono state incontrate con le perforazioni e in molti scavi archeologici. età: olocene (10-0 ka. stage 1). 5.3 evoluzione geologica del colle sulla superficie di erosione delle argille del pliocene, che si rinviene nelle perforazioni a quote variabili tra tra + 5 m s.l.m. e – 8 m s.l.m., si è deposta la serie continentale della formazione del paleotevere, costituita da livelli ghiaiosi, sabbiosi e argillosi. questa formazione è stata parzialmente erosa da diversi cicli glaciali, fino a quello corrispondente allo stage 14, in corrispondenza del quale si sono deposte le vulcaniti più antiche dell’area romana, che hanno parzialmente colmato depressioni e incisioni. su tali vulcaniti si sono poi adagiate le colate piroclastiche provenienti dai colli albani con le pozzolane rosse e nere. in corrispondenza dello stage 12 si ha una intensa attività erosiva con i fossi, i torrenti e lo stesso tevere che scavano i terreni precedentemente depostisi. una delle profonde incisioni scavate durante questo ciclo, sul cui andamento la ricerca geologica non ha ancora detto l’ultima parola, e che sembra comunque orientata da sud-est a nord-ovest, con pendenza verso nordovest, interessava le pendici orientali del rilievo capitolino in formazione. tale incisione che crea, sul lato meridionale del colle, un’ansa che si appoggia alle serie piroclastiche antiche e alla stessa formazione del paleotevere e sembra poi correre parallelamente a via dei fori imperiali, trovando la sua prosecuzione nella attuale valle dell’anfiteatro flavio, ove raggiunge quote attorno a 0 m s.l.m. ai piedi dell’attuale colle capitolino il ciclo erosivo dello stage 12 asportò, parzialmente, e a luoghi interamente, la sequenza dei tufi precedentemente depostisi (tufo del palatino; tufo giallo di prima porta e sequenza piroclastica di grottarossa) e incise profondamente la formazione del paleotevere lasciando pochi metri di ghiaie sul fondo della valle. inoltre vennero parzialmente erosi e rideposti il tufo rosso a scorie nere e le pozzolane rosse, la cui messa in posto si verificò proprio durante il climax di questa fase erosiva. residui di questo processo erosivo, che ha messo a giorno affioramenti diffusi e potenti di tufo del palatino, si rinvengono nel lato meridionale del colle, lungo via della consolazione e in corrispondenza dei ruderi dell’umbilicus urbis (fig. 18) la sequenza piroclastica di grotta rossa non si rinviene nel colle capitolino, e più in generale nel centro storico di roma, in quanto è stata completamente asportata. durante il successivo ciclo interglaciale avvenne il colmamento dell’incisione con sabbie limose giallastre e verdastre di ambiente continentale, contenenti orizzonti di materiale vulcanico rimaneggiato ricco in pomici. questo complesso, in base ai dati stratigrafici e alle datazioni, è stato attribuito alla formazione di san paolo. i terreni della formazione san paolo si appoggiano sui fianchi settentrionale, orientale (in parte) e meridionale del colle e si sono deposti nell’ansa precedentemente segnalata. la messa in posto di questi terreni, anche se difficilmente verificabile, potrebbe essere stata controllata anche da una dislocazione tettonica, una faglia, che potrebbe aver rialzato la porzione nord della collina rispetto alle aree circostanti. il colmamento della valle si protrasse per lungo tempo in concomitanza con la risalita del livello del mare (stage 11) portando i materiali della san paolo a 429geologia, idrogeologia e ... fig. 17 affioramento della formazione aurelia nello scavo del tempio di giove. outcrop of aurelia formation in the excavations of temple of jupiter. fig. 16 fronte sud-orientale del colle. affioramento della formazione aurelia (fa) sopra il tufo lionato (tl). outcrop of aurelia formation on the southern side of the capitoline hill. 430 a. corazza, l. lombardi & f. marra fig. 18 foro romano, umbilicus urbis. tufo del palatino (tp) con tracce dei tagli per ricavarne blocchi. roman forum, umbelicus urbis, outcrop showing the cuts realised to extract squared blocks of tufo del palatino. fig. 19 sezione di de angelis d’ossat (1932) realizzata durante gli scavi per il vittoriano al lato del museo del genio. i – sabbie grossolane con materiale vulcanico, ghiaie e ciottoli; ii – argilla grigia; iii – sabbie grossolane con materiale vulcanico, ghiaie e ciottoli (i, ii, iii: formazione di san paolo); ivmateriale pozzolanaceo, con granuli bianchi, di colore nero talvolta rossastro; iv1 – tufo litoide (iv, iv1: tufo lionato); v – sabbie con materiale vulcanico e intercalazioni argillose e ghiaiose; vi – tufo vulcanico alterato; vii successione di strati marnosi, argillosi e sabbiosi, talvolta ghiaiosi con concrezioni calcaree (v, vi, vii: formazione aurelia). cross-section by de angelis d'ossat (1932), drawn during the excavation of the hill side near to the museo del genio, to build the vittoriano. i coarse sand with volcanic material, gravel and pebbles (i, ii, iii,: san paolo formation); iv pozzolanaceous material, black and sometimes reddish in color, with white grains; iv1 lithified tuff (iv, iv1: tufo lionato); v sand with volcanic material and intercalation of clay and gravel; vi altered volcanic tuff; vii succession of marly, clayey and sandy layers, sometimes with gravel and calcareous concretions (v, vi, vii: aurelia formation). quote elevate (circa 40 m s.l.m. alle spalle del foro di traiano). un’altra erosione, associata al successivo ciclo glaciale (stage 10) asporta in parte i terreni della san paolo, e le sottostanti vulcaniti, creando un nuovo reticolo idrografico che ricalcava sostanzialmente l’andamento del precedente, con corso d’acqua a direzione nw-se che, dal lato del teatro marcello, affluiva in un tevere antico il cui asse di drenaggio presumibilmente coincideva con quello attuale. su questa nuova superficie morfologica si adagia la colata piroclastica del tufo lionato, che si presenta inclinata in direzione w e nw, con una netta superficie di contatto in forte pendenza e con un forte aumento di spessore spostandosi da sud a nord e da oriente a occidente. il tufo lionato è la formazione meglio visibile lungo il perimetro del colle. di grande interesse e utilità, per la ricostruzione della geologia del colle, sono la storica sezione (fig. 19) di de angelis d’ossat (1932, p. 331) e una sezione riportata da di paola (1986) che interessa trasversalmente i propilei del vittoriano (fig. 20) e la classica sezione di portis (1893, tav.1, fig. 1, p 52), riportata nella fig. 21. non sappiamo come fosse l’assetto morfologico dopo il deposito del tufo lionato, ma possiamo ipotizzare che si venne a creare un esteso plateau, originato 431geologia, idrogeologia e ... fig. 20 sezione parallela ai propilei del vittoriano con evidenziati i terreni di riporto (r), la formazione aurelia (fa) e il tufo lionato (tl) (da di paola, 1986). cross-section parallel to the propylaea of the vittoriano showing the extent of anthropic fill and the tufo lionato outcrop. fig. 21 sezione di portis (1893). fa = formazione aurelia; tl = tufo lionato; fsp = formazione san paolo. cross-section by portis (1893). dal riempimento di tutte le paleodepressioni. sappiamo comunque che questo plateau ebbe, geologicamente parlando, vita breve, dal momento che l’azione erosiva associata allo stage 10 riprese immediatamente. le valli nuovamente incise vennero quindi ricolmate fino alla quota di circa 45 m s.l.m., a seguito della deposizione dei terreni continentali costituiti da piroclastiti rimaneggiate e da argille, limi e sabbie della formazione aurelia (stage 9). di questa formazione sono osservabili, come già ricordato, vasti affioramenti sul ciglio della collina, sul lato del vico jugario, apparentemente a contatto orizzontale, e forti spessori sulla sommità del colle negli scavi del tempio capitolino. le successive fasi erosive (stages 8 e 6), accompagnate da un intenso sollevamento di tutta l’area romana, iniziato a partire da circa 250.000 anni fa, determinarono un forte rimodellamento della morfologia, originando, tra gli altri, il colle capitolino. deve attribuirsi probabilmente a questo periodo la deviazione del corso dell’affluente del tevere che scorreva lungo l’attuale via dei fori imperiali. due nuove valli si vengono ad impostare con direzione quasi ortogonale a quella antica. si tratta del tratto meridionale del fosso labicano, che proprio in corrispondenza dell’anfiteatro flavio devia a 90° dall’originario corso per dirigersi a meridione verso il circo massimo, e della prosecuzione dello spinon, che scende lungo la valle della suburra fino alla torre dei conti, e da qui prosegue (velabrum minus) tra il colle capitolino e il palatino per ricongiungersi al velabrum maius, l’attuale zona che ospita i ruderi del circo massimo. l’ultimo glaciale determina un’ulteriore fase erosiva nell’area, con l’incisione (in conseguenza anche delle ultime fasi di sollevamento regionale) fino a quota di 50 m sotto il livello attuale del mare in corrispondenza della valle del tevere, e il conseguente approfondimento dei torrenti che in esso confluivano. il successivo colmamento porta le piane del tevere e del velabro alle quote che calpestarono i primi abitanti dell’area, che poterono osservare il colle capitolino in quella forma che si è tentato di ricostruire nel presente studio. 6. gli ipogei e le cave i tufi lapidei costituiscono materiali facilmente lavorabili e scavabili, ne sono un esempio lampante le infinite cavità artificiali che si rinvengono in tutte le aree vulcaniche. il campidoglio, con i suoi affioramenti esposti di tufo litoide e di “cappellaccio” era un sito ideale per estrarre materiale da costruzione. inoltre, come già ricordato, i tufi si caratterizzano per una facile lavorabilità anche con strumenti primitivi. in particolare il “cappellaccio”, per la sua fissilità orizzontale, era facilmente trasformabile in lastroni o blocchi che dovevano essere regolarizzati solo sui lati. non è casuale che il cappellaccio sia il primo tufo lapideo che viene usato nell’area romana. il cappellaccio affiora diffusamente sul lato del foro romano e ancora oggi si vedono le tracce dello scavo di blocchi asportati dall’ammasso. purtroppo i tagli moderni di via della conciliazione hanno cancellato gran parte delle tracce dell’intensa attività di scavo, ma ai piedi del campidoglio, e nei pressi del portico degli dei consenti, sono perfettamente osservabili le asportazioni di lastre di tufo (vedi fig.10). dalle indagini esperite si può ipotizzare che alla base del tabularium esistesse una vasta area di escavo e che lo stesso tabularium e il portico degli dei consenti siano stati appoggiati contro il fronte di una cava; ciò potrebbe anche spiegare la forma particolare di quest’ultima struttura (fig. 22). contemporaneamente al cappellaccio fu utilizzato un altro tipo di tufo, come colore e struttura molto simile al tufo giallo della via tiberina (o tufo di grotta oscura) anche se meno tenace e meno lapideo. sul versante meridionale del campidoglio si sono osservati affioramenti di questo tipo di tufo e la sua presenza è certa alla base del palatino, ai piedi del gianicolo e lungo i versanti del piccolo aventino4. solo in una seconda fase iniziò l’uso del tufo lionato. di maggiore tenacità e consistenza, il suo utilizzo comportava tecniche più sofisticate di estrazione dal banco lapideo e di taglio in blocchi. le cave nel campidoglio si moltiplicarono e esaurite le possibilità di estrazione dal detrito di falda presente alla base delle scarpate, e di quello in parete, deve essere iniziato l’escavo in grotte o gallerie. gallerie scavate nel tufo lionato sono segnalate in tutta la collina: giuntini (1954, pp.9-12) cita la presenza diffusa nel sottosuolo del vittoriano di gallerie, sovrapposte anche in più ordini (ben tre nel sottosuolo del lato occidentale del monumento) e di un lungo cunicolo rettilineo il cui percorso fu seguito, ripulendolo dagli interri, fino sotto la piazza del campidoglio. numerose gallerie di epoca romana rivestite in muratura sono citate da brancia di apricena (2000, p. 27) sotto la chiesa dell’ara coeli. e’ noto dalle fonti che il carcere mamertino era 432 a. corazza, l. lombardi & f. marra fig. 22 portico degli dei consenti. la forma del portico fa presupporre l’addossamento della struttura a un pendio modificato e regolarizzato dall’attività di cava. portico dei consenti, the shape of the structure of the portico suggests that it was built adjacent to the hill side after the latter was modified and straightened by quarry activity. 4 lanciani, 1985, p. 44 cita le cave dell’aventino. ubicato al piede del campidoglio, in una zona detta lautumiae per la diffusa presenza di cave di pietra. in base alle ricerche svolte si può affermare che le aree di cava non potevano essere troppo vicine al mamertino in quanto il carcere è fondato sulle argille della f. di san paolo (fortini, 1998, pp. 5-9). il tufo lionato affiorava invece ad una quota più alta, al di sopra del carcere. in ogni caso era presente certamente più a nord ove, allorchè furono eseguiti gli scavi per il vittoriano, fu rinvenuto il banco di tufo e vaste cavità e accessi alle antiche cave (fig. 23). tutte le cave in sotterraneo di tufo hanno, mediamente, quota di base compreso tra 20 e 15 m s.l.m. e altezze di escavo variabili, con valori massimi in corrispondenza dei vasti affioramenti di via del t. marcello. alcuni accessi sono tuttora osservabili, sia su via del t. marcello, che su via della consolazione e vico jugario e, da queste strade, le gallerie scendono al di sotto della quota della base delle pareti affioranti. inoltre si osservano aperture sul clivo capitolino. sul lato occidentale, ove il tufo lionato raggiunge i massimi spessori, i fronti di cava raggiungevano i 30 metri di altezza e il livello più basso raggiunto dall’attività di scavo si attesta a m 15, poco al di sopra del livello di falda e pochi metri sopra l’orizzonte ghiaioso del paleotevere sede di una importante circolazione idrica. l’attività di scavo del tufo è continuata per tutto il medio evo e, presumibilmente, fino al rinascimento. alcune pareti mostrano cunicoli romani rimasti sospesi in parete, tagliati da crolli, ma, più verosimilmente, da tagli di cave (fig. 24). sui lati nord ed est, e lungo la valle che scende dalla piazza del campidoglio, cavità sono state osservate direttamente durante i lavori per il vittoriano. nel sottosuolo del colle capitolino, oltre agli ipogei per lo sfruttamento del tufo, si riscontrano anche gallerie, cunicoli e ambienti sotterranei di incerta attribuzione. alcune cavità erano certamente destinate a scopi idraulici, come la cisterna sotto il palazzo dei conservatori (fig. 25), di cui parleremo nel paragrafo relati433geologia, idrogeologia e ... fig. 25 cisterna sotto il palazzo dei conservatori (da cassatella, 1984). cistern below the palazzo dei conservatori (from cassatella, 1984). fig. 23 cavità sotto uno dei propilei del vittoriano (da porzio, 1986). cavity below one of the propylaea of the vittoriano (from porzio, 1986). fig. 24 via del teatro di marcello. cunicolo sulla parete in tufo lionato (tl) messo a giorno dalle antiche attività di cava. via del teatro marcello, tunnel exposed by ancient quarry excavation. vo all’acqua, o come le gallerie per la conduzione dell’acqua felice che dalla scala accanto al carcere mamertino raggiungono la piazza del campidoglio e, sempre in sotterraneo, si spingono fino alle fontane della cordonata5. altri sotterranei potrebbero aver avuto uno scopo strategico e di collegamento6, altri ancora probabilmente furono usati per abitazioni e ricovero7. gli ultimi ipogei scavati nel campidoglio sono degli anni ’30, allorchè venne realizzata la galleria che congiunge il palazzo dei conservatori con il palazzo nuovo. questa galleria, che passa sotto la piazza attuale, molto vicina alla fontana dei fiumi, è stata scavata completamente entro terreni di riporto, che nella zona hanno uno spessore di circa 10 metri. la fig. 26 mostra in pianta la diffusione degli ipogei nella porzione del colle capitolino ove è stato realizzato il vittoriano. dalla figura non si possono apprezzare le differenze di quota tra i vari ipogei che, come detto in precedenza, sono spesso situati su più livelli sovrapposti. 7. il campidoglio e l’acqua 7.1 inquadramento idrogeologico l'assetto idrogeologico dell'area romana è caratterizzato dalla presenza, generalmente in profondità, e solo in alcune zone in affioramento, di terreni argillosi, di ambiente marino e di età plio-pleistocenica (unità di monte vaticano). questi terreni, data la loro bassa permeabilità e l’elevato spessore, rappresentano il substrato impermeabile al di sotto del quale nessuna circolazione idrica sotterranea è presente anche se, a volte, le argille presentano delle intercalazioni sabbiose che possono contenere modeste circolazioni idriche. su questo substrato poggia, in gran parte dell’area romana, la successione di sedimenti di ambiente continentale costituita da depositi eterogenei (prevalen434 a. corazza, l. lombardi & f. marra fig. 26 cavità rinvenute durante la realizzazione del vittoriano (da di paola, 1986). cavities exposed during the excavations to build the vittoriano (from di paola, 1986). 5 il papa felice peretti, sisto v, creò nuove gallerie per condurre l’acqua felice sul campidoglio e per alimentare le fontane al piede della gradinata che sale alla piazza. le stesse gallerie sono ancora usate per l’alimentazione dei palazzi del campidoglio e delle fontane. 6 paolo iii fece costruire, probabilmente ripercorrendo un tracciato già esistente, una galleria che collegava il suo palazzo alla piazza del campidoglio 7 da segnalare che durante l’ultima guerra una parte dei sotterranei furono adibiti a ricovero antiaereo. temente argille, limi, sabbie e ghiaie), attribuiti alla formazione del paleotevere, che danno luogo, in sinistra del tevere, a una importante ed estesa circolazione idrica in pressione contenuta nell’orizzonte ghiaioso basale della formazione. tale circolazione emergeva, in epoca romana, con importanti sorgenti (fonte di giuturna, acqua di mercurio, fons apollinis, fonte delle camene, piscina pubblica) situate laddove le incisioni dei fossi e torrenti affluenti del tevere, oggi sepolti sotto i terreni di riporto, intercettavano o si avvicinavano al terreno acquifero. anche ai piedi del campidoglio, sul versante occidentale, le ghiaie affioravano e l’acqua doveva emergere. sul complesso dei sedimenti pleistocenici e, solo in alcune aree, sul complesso delle argille marine, poggiano depositi sabbiosi e orizzonti piroclastici prodotti dall’attività dei distretti vulcanici dei colli albani e dei monti sabatini. anche da questi terreni si avevano sorgenti di qualche interesse. quasi tutte le emergenze sorgentizie sono scomparse in quanto ricoperte dai terreni di riporto. al di sopra dei complessi descritti in precedenza, lungo i corsi d’acqua, sono presenti le alluvioni, di età olocenica, deposte dal tevere e dai suoi affluenti, che nella valle tiberina, ma anche in alcune valli trasversali, poggiano direttamente sul substrato impermeabile. il complesso è costituito da depositi eterogenei (argille, limi sabbie, ghiaie) che raggiungono spessori superiori a 60 metri nella valle del tevere, mentre sono meno potenti (15-30 metri massimo) nelle valli laterali. in sinistra idrografica del tevere, nei dintorni del colle capitolino, o immediatamente al piede del rilievo, confluivano nel corso d’acqua, direttamente o tramite paludi, due importanti torrenti: ove è ora piazza venezia sboccava i l petronia amnis che scendeva dal quirinale e tra il campidoglio e il palatino lo spinon che, scendendo dall’esquilino, affluiva nel velabrum maius, nel quale confluivano anche il fosso labicano e il fosso delle camene. l’assetto idrogeologico viene anche caratterizzato dalla presenza, al di sopra dei terreni di origine naturale, di un manto di terreni di riporto dovuti all'attività antropica di oltre 2.700 anni. questo manto, nelle porzioni più permeabili, è sede anch'esso di falde idriche, generalmente di modesta estensione e potenzialità, che assumono una valenza maggiore in corrispondenza delle paleovalli, in vicinanza del tevere e laddove si hanno importanti perdite dalla rete acquedottistica. 7.2 idrogeologia del campidoglio nella zona del colle capitolino si rinviene l'acquifero più importante dell'area romana che, come detto in precedenza, è presente in quasi tutta la zona della città, in sinistra idrografica del tevere. si tratta dell’orizzonte ghiaioso della formazione del paleotevere ii, che mostra uno spessore variabile che arriva fino a oltre 10 metri e che contiene una importante circolazione idrica in pressione. tale circolazione risulta confinata e in pressione grazie alla sovrastante presenza dei terreni prevalentemente argillosi e poco permeabili della medesima formazione. da questa falda idrica traevano origine alcune delle sorgenti più importanti della zona: le acque lautole, forse calde e mineralizzate, ormai scomparse; la fonte di giuturna e, indirettamente, il tulliano (punto 2, tav.1). collegata a questa falda era anche l’emergenza sorgentizia, da noi denominata fons servili (punto 1, tav.1). tale emergenza, oggi scomparsa, era situata ai piedi della collina all’incrocio tra il vicus jugarus e via del teatro marcello, dove le condizioni geologiche permettevano l’affioramento delle ghiaie acquifere. una descrizione dettagliata della fons servilii e della sorgente del tullianum verrà fatta nel paragrafo successivo. all’intorno del campidoglio e nello stesso colle il livello piezometrico della falda contenuta nelle ghiaie ha una quota compresa tra 13 e 14 m s.l.m.. la circolazione mostra delle oscillazioni del livello statico che, relativamente a due anni di osservazioni, non hanno superato il mezzo metro, con alti nei primi mesi dell'anno e bassi in settembre ottobre. il periodo erosivo verificatosi durante lo stage 12 ha determinato in alcune zone il completo asporto dei terreni poco permeabili della f. del paleotevere ii con erosione anche delle ghiaie di base. in queste zone, che corrispondono alla parte nord-orientale della collina, si ha la diretta sovrapposizione della formazione di s. paolo sull’orizzonte ghiaioso acquifero. la f. di s. paolo, in ragione soprattutto della sua variabilità litologica, pur essendo caratterizzata da terreni mediamente poco permeabili, al contrario dei termini limo-argillosi della f. del paleotevere ii, non è in grado di garantire con continuità il confinamento della circolazione in pressione delle ghiaie. laddove la maggiore permeabilità dei terreni sovrastanti lo ha permesso si sono determinate le condizioni per una risalita dell’acqua all’interno della f. di s. paolo, fino ad un livello di equilibrio con le circostanti quote piezometriche della falda confinata in pressione. la presenza di cospicue quantità d’acqua dentro la f. di s. paolo è in effetti testimoniata dai resoconti degli scavi per la costruzione del lato orientale del vittoriano le cui fondazioni sono state spinte fino al livello di una falda contenuta all’interno di sabbie chiaramente riconducibili alla formazione in questione. il livello della falda, in un decennio di osservazioni durante l’edificazione del monumento, ha subito variazioni annue massime di circa 50 cm tra 12,43 e 12,97 m s.l.m. (de angelis d’ossat, 1932, p. 334; giuntini, 1954, p. 11). nel colle capitolino circolazioni idriche a quota superiore a quella dell’orizzonte ghiaioso sono praticamente inesistenti. infatti, le due sommità del colle, a parte la completa impermeabilizzazione del suolo dovuta alle costruzioni e all’asfalto, sono coperte dalla formazione aurelia, argillosa e impermeabile, che blocca qualsiasi infiltrazione delle acque meteoriche. contributi all’infiltrazione di acqua nel sottosuolo non vengono nemmeno dalla porzione centrale del campidoglio, la zona dell’asylum e tutta la parte depressa trasversale al colle, che collega idealmente piazza dell’ara coeli con il foro. tale zona ha infatti una superficie molto limitata e viene caratterizzata dalla presenza, sotto la coltre dei riporti, dei terreni argillosi poco permeabili della f. di san paolo e della f. aurelia. l’unica formazione presente sul campidoglio in grado di assorbire e trasmettere nel sottosuolo le acque di pioggia è quella del tufo lionato che però attualmente affiora solo con pareti verticali, che impediscono l’infiltrazione, o è sepolta sotto un forte spessore di 435geologia, idrogeologia e ... riporti. in epoca arcaica e repubblicana, prima degli interventi massicci dell’uomo sulla collina, è possibile che alla base della formazione del t. lionato vi fosse un modesto accumulo di acque sotterranee, la cui esistenza potrebbe anche essere avvalorata dalla presenza di cunicoli, di chiara funzione idraulica ma di non certa finalità, che percorrono questa formazione e che potevano essere destinati al drenaggio della piccola falda in questione. nelle parti di pianura attorno al campidoglio sono stati rinvenuti numerosi pozzi arcaici tramite i quali si prelevava acqua, a poca profondità, dalle alluvioni o dalle formazioni più antiche presenti ai margini del colle. 7.3 approvvigionamento idrico del colle in antico, come in epoca moderna, l’unica fonte d’acqua sotterranea poteva essere rappresentata dalla circolazione idrica delle ghiaie sovrapposte alle argille marine dell’unità monte vaticano. coloro che, in epoca arcaica, frequentarono o abitarono le porzioni alte del colle potevano disporre di risorse idriche con tre sistemi: creare bacini di raccolta d’acqua piovana, realizzando depressioni artificiali nei terreni argillosi della formazione aurelia o della f. di san paolo; costruire delle cisterne; ricorrere a pozzi profondi che raggiungessero la circolazione idrica delle ghiaie. nulla sappiamo circa la realizzazione di bacini di raccolta mentre è noto che (cassatella, 1984, p. 272; colini, 1941, p. 83) in epoca arcaica fu realizzata una cisterna (fig. 27). la cisterna fu modificata in epoca successiva (ii sec. a.c.) con la realizzazione di tre braccia convergenti verso il centro ove preesisteva il pozzo di prelievo dell’acqua con secchio. un’altra cisterna, anch’essa arcaica, fu rinvenuta sotto l’attuale protomoteca. per i pozzi si hanno numerose segnalazioni alle pendici del campidoglio (colini, 1941, pp.86-99) mentre nel rilievo capitolino l’unico dato disponibile, allo stato attuale delle nostre conoscenze, è quello relativo ad un pozzo scavato entro una delle gallerie nel tufo lionato, che interessano, a quota molto bassa, il sottosuolo del colle. tale pozzo, che sembrerebbe aver raggiunto le ghiaie di base, poteva essere a servizio delle attività di cava in sotterraneo. da questi cenni sembra si possa affermare che le cisterne per la raccolta dell’acqua rappresentassero l’unica fonte di approvvigionamento idrico delle parti alte del colle fino alla conduzione dell’acquedotto marcio, avvenuta nel 144 a.c. il letto dello speco dell’acquedotto marcio ha, in corrispondenza di porta maggiore, una quota di m 55,70 s.l.m. il campidoglio dista da porta maggiore circa 4 km (passando per le alture dell’esquilino) per cui, ammettendo una pendenza intorno a 0,5 per mille, il canale avrebbe potuto raggiungere il colle a circa 53 metri s.l.m., cioè al di sopra delle sommità dell’arx e del capitolium, e in condizioni quindi di alimentare tutta la zona. non sono stati ritrovati elementi utili a chiarire come l’acquedotto, che doveva provenire dall’esquilino, raggiungesse il colle. doveva esistere un sifone rovescio con il ventre poggiato su arcate situate nella valle dello spinon o sulla sella di collegamento con il quirinale. di queste strutture non è stata trovata traccia neanche negli scavi attuali che hanno interessato gran parte di via dei fori imperiali. tuttavia è possibile che i numerosi lavori realizzati in antico possano aver cancellato elementi importanti della conduttura dell’acqua, anche se è difficilmente ipotizzabile una sua completa distruzione. più tardi, attorno al 127 a. c., anche l’acquedotto dell’acqua tepula, il cui speco a porta maggiore ha una quota di due metri più alta della marcia, raggiunse il campidoglio. le fonti (frontino, i-ii sec d.c.) non lasciano adito a dubbi circa la doppia alimentazione del colle, anche se risulta difficile comprenderne le ragioni. mentre, come detto, all’esterno del colle non si hanno tracce di spechi, sul colle, lungo la via di monte tarpeo, che da piazza della consolazione sale alla piazza del campidoglio, si ha uno specus scavato nel tufo rosso, con la classica forma a losanga (fig. 28). lo speco8, che si segue su tre punti, ha una quota di circa 26 metri s.l.m., quota troppo bassa per essere interpretato come canale adduttore di uno dei due acquedotti citati. potrebbe essere una diramazione in discesa proveniente da un eventuale serbatoio o da un castellum ubicato sul colle o, ancora, potrebbe essere un cunicolo di scarico. sembra comunque che il condotto scenda dalla sommità del campidoglio verso il 436 fig. 27 – sezione della cisterna sotto i l palazzo dei conservatori (da cassatella, 1985). cross-section of the cistern below the palazzo dei conservatori (from cassatella, 1984). 8 lo speco con copertura a cappuccina ha un rivestimento in coccio pesto di 2-3 cm di spessore, purtroppo non si osservano incrostazioni. a. corazza, l. lombardi & f. marra vicus jugario e, in tal caso, potrebbe essere stato utilizzato per utenze ubicate tra questo vico e via del t. di marcello (colini, 1945, pp. 17-23). non sappiamo fino a quando il campidoglio ha ricevuto acqua dai due acquedotti. i restauri noti indicano che il marcio dopo il ix secolo sicuramente smise di funzionare, mentre l’acqua tepula fu certamente intercettata per servire ciò che restava delle terme di caracalla. in una prima fase le terme furono servite dall’acqua giulia per la cui sottrazione all’uso pubblico l’imperatore immise una nuova sorgente nell’acquedotto marcio9, il novo fonte antoniniano. nel medio evo i chiostri della basilica dell’ara coeli e le altre comunità religiose si servivano di acqua piovana accumulata in cisterne alimentate durante le stagioni piovose. nel 1437 si costruisce una cisterna nel cortile del palazzo dei conservatori. nel 1576 viene riattivato l’acquedotto vergine che tuttavia non consente, per problemi di quota, di raggiungere il campidoglio. si dovrà aspettare fino al 1587 per avere di nuovo acqua corrente con l’arrivo dell’acquedotto felice. quest’ultimo raggiungeva roma dalle pendici dei colli albani e, alto in quota, aveva la fontana mostra a santa susanna da dove, con un lungo condotto, alimentava il quirinale. da qui, con un lungo sifone rovescio adduceva acqua al campidoglio, alimentando le fontane della piazza e della cordonata (fig. 29). del sifone sono state messe in luce le tubature, affogate nel calcestruzzo, nello scavo del foro di cesare (fig. 30) relativamente all’approvvigionamento idrico in loco, nelle porzioni alte del colle non vi era altra possibilità di avere acqua se non scavando pozzi profondi o realizzando cisterne per l’accumulo di acqua piovana. alla base della collina e nelle piane ad essa circostanti era invece disponibile l’acqua delle circolazioni idriche presenti nelle alluvioni e quella probabilmente emergente dall’acquifero ghiaioso della formazione del paleotevere che, in base alla nostra ricostruzione morfologica, affiorava sul lato meridionale della collina. e’ in quest’area che cassio (cassio, 1756, i p.380) nomina la già citata sorgente ai piedi del campidoglio10, all’angolo tra vicus jugarius e l’attuale via del t. di marcello. 437 fig. 28 cunicolo rivestito in cocciopesto lungo la via di monte tarpeo. tunnel with "cocciopesto" covering in via di monte tarpeo. fig. 29 bottino di distribuzione dell’acqua felice al quirinale. cesspool of the "acqua felice" aqueduct in the quirinale. fig. 30 resti delle tubazioni dell’acquedotto felice negli scavi del foro di cesare. remains of hydraulic casing of the "felice" aqueduct in the excavations at the forum of caesar. 9 uno studio in corso di pubblicazione (l. lombardi e r. coates stephens) indica chiaramente che le terme di caracalla furono servite da un acquedotto proveniente dai colli albani, in una prima fase la julia e quindi la tepula. 10 cassio riporta anche che agrippa, avendo osservato che la sorgente non forniva più acqua alla fontana, provvide a far alimentare la fonte dall’acquedotto geologia, idrogeologia e ... certamente ai piedi del campidoglio vi era la presenza di un’altra sorgente, il tulliano che, fin da epoca arcaica, fu utilizzata e probabilmente sacralizzata. la sorgente è osservabile in un ipogeo sotto la chiesa di san giuseppe dei falegnami. l’ambiente che la contiene è costituito da una struttura circolare, una tholos, apparentemente emicircolare in quanto parzialmente tagliata, sul lato sud, da un più tardo muro rettilineo. nella parte centrale del tulliano vi è un pozzetto (fig. 31) che raggiunge una vena d’acqua corrente la cui origine, secondo la tradizione cristiana, è attribuita a un miracolo di s.pietro il quale, prigioniero nel tulliano, fece zampillare l’acqua per battezzare 24 prigionieri, come lui rinchiusi nel carcere, e gli stessi carcerieri. si tratta certamente di una emergenza naturale di cui non si rinvengono tracce dirette nelle fonti, mentre è possibile, attraverso l’analisi dei testi antichi fatta da coarelli (1997, pp. 250-254), avanzare alcune considerazioni. ai piedi della porzione nord orientale del campidoglio viene localizzata una delle porte che si aprivano nella cinta serviana, la porta fontinalis, dalla quale partiva i l tratto urbano della via flaminia (coarelli, 1988, p. 414). lo stesso coarelli assume come certo che la porta dovesse essere ubicata nei pressi di una sorgente, la fons, da dove le sacerdotesse si muovevano per andare a fare offerte al tempio di fons. il tempio corrisponde all’edificio in precedenza attribuito al sepolcro gentilizio della gens claudia, localizzato da coarelli ai piedi dell’attuale vittoriano. la localizzazione della porta resta tuttavia dubbia, essa infatti doveva trovarsi poco lontano dal crinale della sella che congiungeva il campidoglio al quirinale. collina della quale ci restano poche tracce per il susseguirsi di interventi urbanistici effettuati da cesare, traiano, adriano ed altri. le alterazioni della morfologia del luogo possono aver modificato l’andamento del crinale e quindi, a meno di studi mirati, allo stato delle conoscenze non è possibile indicare con esattezza la localizzazione della porta. se le mura erano sulla sella è improbabile, per non dire impossibile, che esistesse una sorgente non solo per motivi geomorfologici, ma soprattutto perchè i terreni affioranti sulla sella (costituiti da un sottile strato di tufo litoide poggiato su limi argillosi) non erano in grado di fornire l’infiltrazione necessaria ad alimentare una sorgente perenne. i nostri studi, ma anche quelli di de angelis d’ossat e portis indicano chiaramente che l’acqua negli scavi per il vittoriano, e in genere nell’area, si rinviene a quote comprese tra 13 e 14 m s.l.m., quote molto vicine a quella dell’emergenza sorgentizia del tullianum e molto lontana dalla quota della sella che collegava il quirinale con il campidoglio, che doveva avere quote medie certamente superiori ai 16-18 metri s.l.m. l’unica sorgente nota nell’area è quella del tullianum (la portata attuale della sorgente è molto bassa, meno di 0,1 litri per secondo) ed è quindi molto probabile che questa fonte corrisponda con la fons citata da coarelli. il tullianum, per la forma e le caratteristiche generali della costruzione, in attesa dei previsti scavi, sembra poter essere interpretato come un antico serbatoio alimentato dalla sorgente; serbatoio che poteva essere collegato sul fronte esterno con una fontana sul modello delle fontane arcaiche greche, le krenai (tollekastenbein, 1990, pp. 25-28) il ritrovamento poco lontano dal tullianum, e ad una quota più bassa, della statua di marforio (fig. 32) e di un grande bacino in marmo (fig. 33) (d’onofrio, 1986, pp.261-265) utilizzato nella fontana dei dioscuri sul quirinale, fa ritenere probabile tale interpretazione. la sorgente del tulliano è ancora oggetto di studio e la sua alimentazione, in base a tutti i dati in nostro possesso, è certamente da collegarsi alle ghiaie della f. del paleotevere ii. il livello statico (misurabile entro il pozzetto ricavato nel pavimento del tulliano) è a quota di circa 13 m s.l.m., la stessa quota della circolazione idrica contenuta nelle ghiaie, ma anche le caratteristiche chimiche dell’acqua sono molto simili (corazza & lombardi, 1995). 438 fig. 31 interno del tullianum con la vera dalla quale si vede l’acqua della sorgente. interior of the tullianum with the well-curb showing the water spring. fig. 32 la statua di marforio riutilizzata come fontana. statue of marforio re-utilised as a fountain. a. corazza, l. lombardi & f. marra rispetto ad altre sorgenti legate all’acquifero ghiaioso tuttavia quella del tullianum mostra una portata molto modesta che mal si accorda con le potenzialità idriche della falda in questione. la sorgente del tulliano è molto probabilmente una emergenza collegabile alla circolazione nelle ghiaie, ma localizzata all’interno della formazione di s. paolo, in una zona dove le condizioni idrogeologiche locali hanno permesso una locale risalita della falda idrica in pressione. tali condizioni, come descritto in precedenza, si verificano nella porzione nord orientale della collina, dove è situato appunto il carcere mamertino, e dove la f. di s. paolo poggia direttamente sulle ghiaie acquifere ed è caratterizzata a luoghi da una maggiore permeabilità. e’ molto probabile che l’acqua non scaturisca nel tulliano ma che venga lì condotta attraverso un cunicolo che andava ad intercettare la falda all’interno della collina. la scarsa portata potrebbe essere dovuta alla comunque modesta permeabilità dei terreni della f. di s. paolo oppure, e più probabilmente, alle condizioni del cunicolo che non è più, per danneggiamenti e/o occlusioni, in grado di drenare significativi volumi d’acqua. in attesa di ulteriori scavi il problema circa l’arrivo dell’acqua nel tulliano resta aperto. rigraziamenti si ringraziano la dott.ssa a. mura sommella e la dott.ssa m. albertoni della soprintendenza ecc per la collaborazione e per aver gentilmente fornito dati sulle perforazioni eseguite sul campidoglio. bibliografia albertoni m. (1997) archeologia in campidoglio itinerari didattici d’arte ed i cultura, 84, roma alvarez w., ammerman a. j., renne p. r., karner d. b., terrenato n. & montanari a. (1996) quaternary fluvial-volcanic stratigraphy and geochronology of the capitoline hill in rome geology, 8 (2), pp. 751-754. ammerman a. j. (1990) on the origin of the forum romanum aja cxiv, pp. 627 e ss. ammerman a. j. (1992) morfologia della valle tra palatino e velia boll. arch., 16-18, pp 107-111. ammerman a. j. (1996) the comitium in roma from the beginning am jour. of archaeoly, 100 (1). pp. 121-136 ammerman a. j., & terrenato n. (1996) nuove osservazioni sul colle capitolino bull. com. arch. com. di roma, 98, pp. 35-46. basili r. & bosi c. (1996) morfo-litostratigrafia dell’area romana in sinistra tevere il quaternario, 9 (1), pp. 273-280. bassinot f. c., labeyrie l. d., vicent e., quidelleur x., shakleton n. j. & lancelot y. (1993) the astronomical theory of climate and the age of the brunhes-matuyama magnetic reversal earth plan. sci. lett., 126, pp. 91-108. bergamini l., carboni m. g., di bella l., marra f. & palagi i. (2000) stratigrafical and paleoenvironmental evidences of the pleistocene sediments of monte mario (roma) – eclogae geologicae elvetia, 93 (2), pp. 265-275. blanc a. c. (1939) i l giacimento musteriano di saccopastore nel quadro del pleistocene laziale riv. antropologia, 32, roma. bordoni p. & valensise g. (1998) deformation of the 125 ka marine terrace in italy: tectonic implications in: i. s. stewart coastal tectonic, geol.soc. spec. pub., 146, pp. 71-110. brancia di apricena m. (2000) il complesso dell’ara coeli sul colle capitolino – quasar ed., roma. brocchi g. b. (1820) dello stato fisico del suolo di roma per servire di illustrazione alla carta geognostica di questa città roma. canfora p. (2000) i contesti archeologici dell’età romulea e nella prima età regia – in: carandini & cappelli (a cura di) roma, romolo, remo e la fondazione della città electa ed., roma, pp. 6873. carafa p. (1996) la “grande roma dei tarquini” e la città rotuleo-numana bull. com. arch. com. di roma, 98, pp. 7-34. carandini a. & cappelli r. (a cura di) (2000) roma, romolo, remo e la fondazione della città electa ed., roma. cassatella a. (1984) favisae capitolinae in: luciani r. (a cura di) roma sotterranea cat. mostra, pp. 271-275. cassio a. (1756) corso delle acque antiche – roma. cazzella a. (2001) sviluppi verso l’urbanizzazione a roma alla luce dei recenti scavi nel giardino romano bull. comm. roma, 102, pp. 265-268. clerici e. (1893) notizie intorno alla natura del suolo di roma rend. r. acc. lincei, 2, pp. 271-275. coarelli f. (1974) guida archeologica di roma arnoldo mondadori ed. , verona. coarelli f. (1988) il foro boario. dalle origini alla fine della repubblica quasar ed., roma. coarelli f. (1992) il foro romano. periodo repubblicano e augusteo quasar ed.,roma. coarelli f. (1995) roma guide archeologiche laterza, laterza ed., bari. coarelli f. (1997) il campo marzio. dalle origini alla fine della repubblica quasar ed, roma. 439 fig. 33 il grande catino in marmo utilizzato nella fontana del quirinale. the large marble tub re-utilised in the quirinale fountain. geologia, idrogeologia e ... colini a. m. (1941) pozzi e cisterne bull. arch. gov., 69, pp. 71-99. colini a. m. (1942) aedes veiovis inter arcem et capitolium bull. arch. gov., 70, pp. 5-55. colini a. m. (1945) ninfeo di vico jugario rend. acc. pont., 21, 1945-1946, pp. 17-23. colini a. m. (1965) il campidoglio nell’antichità capitolium, 40 (4), roma, pp. 175 ss. conato v., esu d., malatesta a. & zarlenga f. (1980) new data on the pleistocene of rome quaternaria, 22, pp. 131-176 corazza a. & lombardi l. (1995) idrogeologia dell’area del centro storico di roma in: funiciello r. (a cura di) la geologia di roma. il centro storico mem. descr. carta geol. d’it., 50, roma, pp. 178211. de angelis d’ossat g. (1930) sul valore cronologico del cranio umano fossile scoperto presso roma boll. soc. geol. it., 49, roma de angelis d’ossat g. (1931) il sottosuolo dei mercati traianei e del foro di augusto atti della pont. acc. delle scienze nuovi lincei, 84, pp. 226-234. de angelis d’ossat g. (1932) una sezione geologica del colle capitolino atti della pont. acc. delle scienze nuovi lincei, 85, pp. 327-335. de angelis d’ossat g. (1940) la sella tra campidoglio e quirinale capitolium, 21, pp. 17-23. de angelis d’ossat g. (1942) nuove sezioni geologiche dei colli di roma boll. soc. geol. it., 61, pp. 22-48. de angelis d’ossat g. (1943) il campidoglio, genesi del colle capitolium, 18, pp. 69-74. de angelis d’ossat g. (1944) la formazione fluviolacustre del campidoglio (roma) boll. r. uff. geol., 69 (6), pp. 117-127. de rita d., funiciello r. & parotto m. (1988) carta geologica del complesso vulcanico dei colli albani progetto finalizzato ‘geodinamica’, c.n.r., roma. de rita d., funiciello r., corda l., sposato a. & rossi u. (1993) carta geologica del complesso vulcanico sabatino -“quaderni de "la ricerca scientifica", 114, progetto finalizzato ‘geodinamica’ monografie finali, vol. 11, c.n.r., roma. di paola r. (1986) il complesso monumentale della mole del vittoriano in: soprint. beni amb. e arch. del lazio il vittoriano. materiali per una storia pp. 117-167, roma. d’onofrio c. (1986) le fontane di roma roma società ed., roma. fornaseri m, scherillo a. & ventriglia u. (1963) la regione vulcanica dei colli alabani cnr, roma. fortini p. (a cura di) (1998) carcer tullianum electa ed., roma. fortini p. (2000) la difesa del colle capitolino e l’area del carcer tullianum in: carandini a. & cappelli r. (a cura di) roma, romolo e remo e la fondazione di roma, electa ed, pp. 325-326, roma. funiciello r. (a cura di) (1995) la geologia di roma. il centro storico mem. descr. carta geol. d’it., 50, roma. giordano g., esposito a., de rita d., fabbri m., mazzini i., trigila a., a, rosa c., funiciello r., (2003), the sedimentation along the roman coast betwe en middle and upper pleistocene: the interplay of eustatism, tectonics and volcanism new data and review il quaternario, italian joumal of quaternary sciences, spec. vol. inqua, 16. giuntini a. (1954) sulla costruzione del vittoriano vitali e ghianda editori, roma. hearthy & dai pra (1986) aminostratigraphy of quaternary marine deposits in the lazio region of central italy in: a. ozer, c. dating mediterranean shorelines, zeitschrift fuer geomorphologie, supplementband , 62, vita-finzi ed., pp. 131-140. karner d. b. & marra f. (1998) correlation of fluviodeltaic aggradational sections with glacial climate history: a revision of the classical pleistocene stratigrafy of rome geological society of american bulletin, 110 (6), pp. 748-758. karner d. b. & renne p. r. (1998) 40ar39 ar geocronology of roman volcanic province tephra in the tiber river valley. age calibration of middle pleistocene sea-level changes geological society of american bulletin, 110 (6), pp. 740747. karner d. b., marra f., florindo f. & boschi e. (2001 a) pulsed uplift estimated from terrace elevations in the coast of rome: evidence for a new phase of volcanic activity? earth and planetary scienze letters, 188, pp. 135-148. karner d. b., marra f. & renne p.r. (2001 b) the history of the monti sabatini and alban hills volcanoes: growndwork for assessing volcanictectonic hazards for rome journ. of volc. and geoth. res, 107, pp. 185-219. lanciani r. (1975) le acque e gli acquedotti di roma ristampa anastatica di “topografia di roma antica. i commentarii di frontino intorno le acque e gli acquedotti”, reale accademia dei lincei, anno cclxviii (1880-1881), quasar ed., roma. lanciani r. (1985) rovine e scavi di roma antica (traduzione in italiano dell’edizione originale in inglese), i ed. london, 1897, quasar ed., roma. lanciani r. (1902) le escavazioni del foro, l’area di vulcano bull. com., 9, pp. 125-133. lombardi l. & coates r. (in stampa) l’acquedotto antoniniano boll. arch. roma, roma. lugli g. (1946) roma antica il centro monumentale roma. marra f., carboni g., di bella l., faccenna c., funiciello r. & rosa c. (1995) il substrato pliopleistocenico nell’area romana boll. soc. geol. it., 114, pp. 195-214. marra f. & rosa c. (1995) stratigrafia e assetto geologico dell’area romana in funiciello r. (a cura di) la geologia di roma. il centro storico mem. descr. carta geol. d’it., 50, roma, pp. 49-118. marra f., florindo f & karner d. b. (1998) paleomagnetism and geochronolog of early middle pleistocene depositional sequenze near rome: comparation with the deep sea δ18o climate record earth and planetary science letters, 159, pp. 147-164. mattias p.p. & ventriglia u. (1970) la regione vulcanica dei monti sabatini e cimini mem. soc. geol. it., 9, pp. 3-331. milli s. (1997) depositional setting and high-frequency sequence stratigraphy of the middle440 a. corazza, l. lombardi & f. marra upper pleistocene and holocene deposits of the roman basin. geol. rom., 33, pp. 99-136. mura sommella a.(1984) l’esplorazione per il restauro del tabulariumquad. centro studi arch. etrusco-italica, 8, archeologia laziale, 6, pp. 159 e segg. muñoz a. & colini a.m. (1930) il campidoglio roma. muñoz a. (1943) l’isolamento del colle capitolino roma. packer j. e. (1972) la casa di via giulio romano bull. com. roma , 81, pp. 127-148. ponzi g. (1858) sullo stato fisico del suolo di roma giorn. arcad. sci. lett. art., 9, roma, pp. 28-49. ponzi g. (1872) carta geologica del bacino di roma boll. soc. geogr. it., 17, roma. portis a. (1893) contribuzioni alla storia fisica del bacino di roma e studii sopra l’estensione da darsi al pliocene superiore. parte prima. una nuova sezione geologica del colle capitolino l roux e c. editori, torino. portis a. (1905) studi e rilievi geologici del suolo di roma ad illustrazione specialmente del foro romano atti soc. it. sc. nat., 43, pp. 383-421. portis a. (1910) notizie dal palatino e foro romano boll. soc. geol. it., 29, porzio p. l. (1986) la forma architettonica del vittoriano nei disegni e nei modelli della fabbrica in: soprintendenza beni ambientali e architettonici : il vittoriano materiali per una storia, pp. 37-90. sappa m. & pasquini e. (1997) la geostruttura del campidoglio quarry & construction, aprile ’97, pp. 57-60. sappa m. & pasquini e. (1998) contributo alla conoscenza della geologia del campidoglio geam, 4, pp. 243-249. segre g.(1948 a) esame petrografico delle alluvioni di saccopastore riv. antrop., 36, roma. segre g.(1948 b) sulla stratigrafia dell’antica cava di saccopastore rend. acc. naz. lincei, 4, roma. sorgi c. (1994) la successione morfo-litostratigrafica in destra tevere dell’ambito dell’evoluzione geologica quaternaria dell’area romana (tesi di laurea, relatore carlo bosi), università degli studi di roma "la sapienza". svetonio (i-ii sec. d.c.) vita dei cesari cal. 34, garzanti ed. 1982, p. 201. tolle-kastenbein r. (1993) archeologia dell’acqua. la cultura idraulica nel mondo antico longanesi & c. ed., milano. totti b. (1638) ritratto di roma moderna gabinetto comunale delle stampe, inv. g.s. 1653, roma. ventriglia u. (1971) la geologia della città di roma a cura della amministrazione provinciale di roma, roma. ventriglia u. (2003) geologia del territorio del comune di roma a cura della amministrazione provinciale di roma, roma. verri a. (1909) sulla natura del terreno di roma a sinistra del tevere boll. soc. geol. it., 28, pp. 173202. verri a. (1915) carta geologica di roma. cenni spiegativi istituto geografico di agostini, novara. verri a. (1920) notizie geologiche sul colle capitolino boll. soc. geol. it., 39, pp. 3-6. 441 ms. ricevuto l’8 giugno 2004 testo definitivo ricevuto il 9 febbraio 2005 ms. received: june 22, 2004 final text received: february 9, 2005 geologia, idrogeologia e ... sess 5_16022011_edi as.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 the climatic changes between 5 and 3 kyr cal bp in central mediterranean: new data giovanni zanchetta 1, n. russell drysdale 2, laura sadori 3, carlo giraudi 4, ilaria isola 5 & eleonora regattieri 1 1dipartimento di scienze della terra, university of pisa, via s. maria 53, 56126 pisa, italy 2department of resource management and geography, university of melbourne, victoria 3010, australia 3 dipartimento di biologia vegetale, università “la sapienza”, piazzale aldo moro 5, 00185 roma, italy 4enea, c.r. casaccia, strada provinciale anguillarese,00123 santa maria di galeria, roma; 5instituto nazionale di geofisica e vulcanologia, sezione di pisa, via della faggiola 32, 56126 pisa, italy corresponding author: g. zanchetta <zanchetta@dst.unipi.it> abstract: zanchetta et al., the climatic changes between 5 and 3 kyr cal bp in central mediterranean: new data. (it issn 0394-3356, 2011) middle holocene to late holocene transition is particularly relevant because marks the passage at two distinct climatic modes. the collation of new and the revision of old data indicates that in central mediterranean this period is characterised by a series of dry/wet climatic phases with pronounced climatic deterioration centred at ca. 4 and 3.5-3.3 ka cal bp. riassunto: zanchetta et al., i cambiamenti climatici tra 5 e 3 ka cal bp nel mediterraneo centrale alla luce dei nuovi dati. (it issn 0394-3356, 2011) il periodo di transizione tra l’olocene medio e l’olocene superiore è particolarmente interessante in quanto rappresenta il passaggio tra due modi di funzionamento climatico. la revisione dei dati disponibili in letteratura associati a nuovi dati recentemente ottenuti nel mediterraneo centrale permette di osservare che questo periodo è caratterizzato da una complessa successione di fasi più aride e più umide con almeno due momenti di pronunciata fase di deterioramento climatico a ca. 4 e 3,5-3,3 ka cal bp. keywords: central mediterranean, climatic changes, holocene parole chiave: mediterraneo centrale, cambiamenti climatici, olocene the predictions on future climate suggest that changes in rainfall and water resources will have important socio-economic and political impacts over the mediterranean region (e.g. lionello et al., 2006). therefore, understanding the past climatic and hydrological variability in this area is an essential prerequisite for establishing future climate scenarios and the possible impact on human society. of particular relevance is the study of the last ca 5000-6000 years because the boundary conditions of the climate system did not change dramatically (in comparison to larger glacial– interglacial changes or at the beginning of holocene), and represent the period of general establishment of an environment and climate which can be compared directly to modern condition (e.g. wanner et al., 2008). climatic change between ca 5 and 3 ka is of particular interest with a succession of dry/wet oscillations, which may have had profound effect on civilizations (e.g. staubwasser & weiss, 2006). the complexity of this period over central mediterranean has been recently pointed our by magny et al., (2009). data from balkans lakes (shkodra, prespa, ohrid, leng et al., 2010; zanchetta et al., submitted), speleothems from apuan alps (drysdale et al., 2007; zanchetta et al., 2007) which indicate that prominent event of climatic deteriorations (including the renewal growth of the calderone glacier, marking the onset of the apennine “neoglacial” giraudi et al., 2011) occurred at ca 4 ka, 3.5-3.3 ka. in may record possessing poor chronological resolutions potentially these events may appears progressively diachronic or can be easily confounded, but the detailed tephrostratigraphy available for this period (zanchetta et al., 2011) can help in solving some the dilemma. references drysdale r.n., zanchetta g., hellstrom j.c., maas r., fallick a.e., pickett m., cartwright i. & piccini l. (2006) late holocene drought responsible for the collapse of old world civilizations is recorded in an italian cave flowstone. geology 34, 101-104. lionello p., malanotte-rizzoli p. & boscolo, r. (2006) mediterranean climate variability. 4, elsevier, the netherlands. giraudi c., magny m., zanchetta g. & drysdale r.n. (2011) the holocene climatic evolution of mediterranean italy: a review of the continental geological data. the holocene, doi: 10.1177/0959683610377529. leng m.j., baneschi i., zanchetta g., jex c., wagner h. & vogel h. (2010) late quaternary palaeoenvironmental reconstruction from lakes ohrid and prespa (macedonia/albania border) using stable isotopes. biogeosciences in press. magny m., vanniere b., zanchetta g., fouache e., 223 224 224 ms. received: testo ricevuto il touchias g., petrika l., coussot c., waltersimonnet a-v. & arnoud f. (2009) possible complexity of the climatic event around 4300-3800 cal. bp in the central and western mediterranean. the holocene, 19, 1-11. staubwasser m. & weiss h. (2006) holocene climate and cultural evolution in late prehistoric–early historic west asia. quaternary research, 66, 372–387. wanner h., beer j., bütikofer j., crowley, t.j., cubasch, u., flückige j., goosse h., grosjean h., joos f., kaplan j.o., küttel m., müller s., prentice c., solomina o., stocker t.f., tarasov p., wagner m. & widmann m. (2008) midto late holocene climate change: an overview. quaternary science reviews, 27, 1791–1828. zanchetta g., drysdale r.n., hellstrom j.c., fallick a.e., isola i., gagan m. & pareschi m.t. (2007) enhanced rainfall in the western mediterranean during deposition of sapropel s1: stalagmite evidence from corchia cave (central italy). quaternary science review, 26, 279-286. zanchetta g., sulpizio r., roberts n., cioni r., eastwood w.j., siani g., caron b., paterne m. & santacroce r. (2011) tephrostratigraphy, chronology and climatic events of the mediterranean basin during the holocene: an overview. the holocene, doi: 10.1177/0959683610377531. january 5, 2011 5 gennaio 2011 zanchetta et al. amq 34(2) 277-291 rettig et al def 1col2.pdf the pleistocene evolution and reconstruction of lgm and late glacial paleoglaciers of the silisia valley and mount raut (carnic prealps, ne italy). lukas rettig1, giovanni monegato2, paolo mozzi1, manja žebre3, luigi casetta4, michele fernetti4, renato r. colucci5 1dipartimento di geoscienze, università di padova, padova, italy. 2cnr istituto di geoscienze e georisorse, padova, italy. 3geološki zavod slovenije, ljubljana, slovenia. 4dipartimento di matematica e geoscienze, università di trieste, trieste, italy. 5cnr istituto di scienze polari, venezia-mestre, italy. corresponding author: g. monegato <giovanni.monegato@igg.cnr.it> abstract: small, peripheral mountain glaciers that remained independent from the large ice-streams throughout the pleistocene glaciations represent an important source of paleoclimatic information in the european alps. here, we present new evidence on the evolution of the silisia valley and paleoglaciers on the northern side of mount raut (carnic prealps, ne italy). the area is characterized by the presence of a variety of sediments and landforms, among them two generations of conglomerates and several deposits of glacigenic origin. the conglomerates are related to the infill and subsequent incision of the silisia valley during plio (?)-pleistocene times, whereas most of the glacigenic deposits can be ascribed to glacier advances during the last glacial maximum (lgm) and following late glacial stadials. during the lgm, the glacial system extended from the headwalls of mount raut (2026 m a.s.l.) down to an elevation of 440 m, and had an equilibrium line altitude (ela) of 1260 m (accumulation-area-balance ratio method aabr). assuming present-day amounts of precipitation, this corresponds to a mean summer air temperature (msat) depression of 8.5 or 9.4°c (� =±2.2°c), when compared to two recent (1960-1990) climatic records in the area. two phases of glacier stabilization during the late glacial were inferred from frontal moraine systems at higher elevations. during the first one, the glaciers had an ela of 1590 m (corresponding to an msat lowering of 6.2 or 7.1°c), whereas at the second one the ela was at 1740 m (msat lowering of 5.3 or 6.1°c). our results allow to better understand the long-term pleistocene evolution of this sector of the south-eastern alps, probably driven by the interplay between climatic fluctuations and phases of tectonic uplift. we further provide new insights on paleoglaciers of the last glacial cycle that may help in the validation of regional climatic models. keywords: last glacial maximum, carnic prealps, palaeoglacier reconstruction, equilibrium line altitude, conglomerates. available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 34 (2), 2021, 277-290 1. introduction the reconstruction of the alpine glacier network during the late pleistocene glaciations has been attempted several times through geomorphological evidence coupled with chronological data (penck & brückner, 1901-1909; castiglioni, 1940; van husen, 1987; ehlers & gibbard, 2004). alpine-scale models of the last glacial cycle were recently performed (jouvet et al., 2017; seguinot et al., 2018), but in several sectors the results are not consistent with the geomorphological evidence. because of their location at the boundary between the mediterranean and continental europe, the alps show a high climate variability (e.g., beniston, 2005; isotta et al., 2014) and are affected by a wide range of air flows and humidity conditions, as sectors of the chain face a continental-type climate and others maritime-type conditions (beniston, 2006). for this reason, large-scale modelling studies need to be tested in selected areas through paleoclimatic proxies to account for these regionally-varying climatic conditions. due to their complex geomorphological and geological structure (dal piaz et al., 2003), the external sectors of the alps are particularly characterized by a large diversity of climatic environments (ivy-ochs et al., 2021). a better knowledge of the pleistocene history of these areas can help to understand the direct relationships between climate change, landscape evolution and the development of glaciers during the cold periods. during the last glacial maximum (lgm), the alps hosted the largest ice cap in europe outside the british and scandinavian ice sheets (hughes et al., 2016; clark et al., 2021 and references therein). in the pre-alpine belts along the southern side of the alps, however, also several small and isolated glaciers developed during the lgm (e.g., carraro & sauro, 1979; baratto et al., 2003; cucato, 2007; forno et al., 2010; monegato, 2012). thanks to their relatively simple geometry, small glaciers permit accurate estimates of their equilibrium line altitude (ela) that integrate field data with numerical ap https://doi.org/10.26382/amq.2021.17 rettig l. et al. proaches of glacier reconstruction (pellitero et al., 2015, 2016). for large and interconnected valley glaciers, on the other hand, ela calculations are still problematic and can only work with models involving the whole mountain range (kuhlemann et al., 2008; višnjević et al., 2020), but without detailed field assessments. as the ela is a parameter that reflects not only local settings but also the regional climate in glaciated areas, its calculation for specific glaciers provides relevant information for inferring robust paleoclimatic reconstructions (e.g., bacon et al., 2001; spagnolo & ribolini, 2019; rea et al., 2020). the present work shows, for the first time, the distribution of quaternary deposits on the northern side of mount raut (carnic prealps). due to its location, close to the friulian piedmont plain, this area is specifically interesting for evaluating the influence of local meteorological factors, such as southerly moisture sources, on the evolution of former glaciations. through mapping and description of the sedimentary units, both the longer -term pleistocene evolution of the area and specifically the extent of paleoglaciers during the lgm and two late glacial stages are reconstructed. the calculated ela values of these glaciers are then used to estimate paleoclimatic parameters for the carnic prealps and to compare them with other regional climate proxies. 2. geomorphological and geological setting the carnic prealps (south-eastern european alps) comprise the drainage basins of the cellina, meduna and arzino streams and reach their maximum elevation in the western sector (cima dei preti, 2703 m a.s.l.). mount raut is located on the southern fringe of the carnic prealps and reaches an elevation of 2026 m (fig. 1). its northern and eastern sides are included in the meduna catchment, while the south-western slope drains towards the cellina catchment. the northern side of mount raut has three major narrow valleys, namely: valine, basson and val bassa (fig. 2). all of them are characterized by ephemeral surface runoff because of the karstic landscape (carulli et al., 2000, 2006). they are tributary valleys of the silisia valley, nowadays partially drowned by the artificial ca’ selva lake. pre-dam 1:25,000 scale topographic maps show that the presently submerged terminal tracts of the valine and basson valley were quite large and flat, with fluvial terraces driven by the incision of the silisia stream. the valley heads are characterized by large (2.25 and 1.5 km2, respectively) and gently dipping plateaus, located above 1400-1500 m and surrounded by the summit crest of mount raut. to the west, the morphology is dominated fig. 1 topographic overview of the mount raut, the silisia valley and its location within the south-eastern alps. for reference, also the extent of some following figures in the paper (figs. 2, 6, and 7) is marked here. the underlying dem was derived from the geoportal of regione autonoma friuli venezia giulia (http://irdat.regione.fvg.it). 278 the pleistocene evolution of the silisia valley and mount raut (carnic prealps) by the towering shape of mount castello (1923 m) and minor peaks towards the clautana saddle (fig. 1). in this upper sector of the silisia catchment, valleys are narrow and deeply incised. the northern side of the silisia valley comprises the steep walls of mount dosaip (2062 m) and minor and low-elevated peaks. the southern slope of the mount raut is characterized by 800 to 1200 m high walls dominating the nearby friulian piedmont plain. the bedrock in the area of the mount raut consists mainly of jurassic limestones (calcari grigi and vajont limestone) overlying late triassic (norianrhaetian) dolostones of the friulian carbonate shelf (dolomia principale). carnian dolostones (monticello formation) crop out in the hangingwall of the e-w trending, south-verging silisia thrust (fig. 2; carulli et al., 2000). the quaternary deposits are widely distributed and have been mapped only at scales from 1:50,000 to 1:100,000 in the general geological maps of the area (zenari, 1929; carulli et al., 2000). more detailed studies are lacking for the silisia valley and the mount raut, and also the drainage basin of the meduna is poor in description about the quaternary succession. only the fig. 2 simplified geological map of the northern side of mount raut with locations of quaternary deposits and moraine ridges. boundaries of geological units and the location of the fault line are from carulli et al. (2000). 279 lacustrine deposits of lake redona (venzo et al., 1975; cavallin & martinis, 1981) and the complex quaternary succession in the lower valley reach (carraro & polino, 1976; venturini, 1985; venturini et al., 2013; monegato & poli, 2015) have been studied. as a result of this lack of detailed data, the extent of the mount raut paleoglacier during the lgm is still debated. in the early map by castiglioni (1940) only a small glacier, just reaching the bottom of the silisia valley, is shown and the meduna valley was considered ice-free. this interpretation was maintained in the most recent climex map (vai & cantelli, 2004). gortani (1959) reported a larger glacier in the silisia valley, merging to that flowing down the meduna trunk valley. a similar large ice extent, including the meduna valley, was reported in the map by ehlers & gibbard (2004), following the review by castiglioni (2004). the area is presently characterized by a quite high precipitation with constant contribution from all seasons (crespi et al., 2018). the 1961-2000 climatology at barcis, according to the local meteorological observatory (www.meteo.fvg.it, last accessed july 9th, 2021), presents mean annual precipitation (map) equal to 2197 mm water equivalent (w.e.), with january the driest month (116 mm w.e.) and october the wettest (287 mm w.e.). the impact of moist southerly winds (scirocco) in the carnic pre-alpine sector generally leads to longlasting orographic precipitation and intense convective systems in all seasons, representing the main driver for such high map (colucci et al., 2021). recent (20042020) mean annual air temperature (maat), calculated for the weather station of pala d’altei (www.meteo.fvg.it, last accessed july 9th, 2021), located at 1528 m about 8.5 km to the south-west, is equal to 6.4°c, with january and february being the coldest months (-1.5°c) and july the warmest (14.8°c). a longer climatological record has been reconstructed by colucci & guglielmin (2015) for the mount canin/kanin (julian alps) at an elevation of 2200 m, representing an important regional source of temperature data that precedes the most recent climatic warming since the 1990s. 3. methods field surveys in the study area were carried out between 2018 and 2021 to describe and map the distribution of geomorphological features and quaternary deposits along the northern side of mount raut and in the silisia valley. the mapping procedure was performed on regional topographic maps at a scale of 1:5000, with the support of lidar data (grid resolution of 1 m, survey carried on 2006) derived from the geoportal of regione autonoma friuli venezia giulia (http:// irdat.regione.fvg.it). older topographic maps (igm at a scale of 1:25,000) allowed reconstructing the topography of the silisia valley prior to the construction of the dam at ca’ selva. based on these elevation data and on the geomorphological and sedimentological evidence found during field work, reconstructions of paleoglacier geometries and elas were carried out using recently developed toolboxes within esri arcmap v. 10.7 (pellitero et al., 2015, 2016). glacier surfaces were reconstructed along flowlines, extending from mapped moraine ridges or the lower limits of till outcrops up to the accumulation areas on the plateaus at the valley head. initially, a subglacial shear stress of 100 kpa, characteristic of the base of alpine glaciers, was applied to the whole length of these flowlines (paterson, 1994; brædstrup et al., 2016; pellitero et al., 2016). this value had to be additionally modified in some parts of the catchment, with the aim of better tuning the reconstructed glacier surface with the geomorphological evidence. generally, the low-lying valley mouths required a lower shear stress (50 kpa) to yield realistic ice-thicknesses, which is compatible with the glacier overriding thicker sediment fills with low yield strength at these locations (thorp, 1991; iverson et al., 2003). for the steep glacial troughs of the basson and bassa valleys, an additional f-factor adjustment, which is a function of the glacier width and thickness, was applied to account for lateral drag exerted by the valley walls (nye, 1952; benn & hulton, 2010; pellitero et al., 2016). from the reconstructed glacier surfaces, elas were calculated using both the accumulation-areabalance ratio (aabr) and the accumulation-area-ratio (aar), as frequently applied in studies on paleoglaciers in the european alps (e.g., federici et al., 2012; monegato, 2012; hofmann et al., 2019; spagnolo & ribolini, 2019). for the aabr-method, balance ratios of 1.56 (representing a global median value) and 1.29 (representing the median value for modern alpine glaciers) were chosen (oien et al., 2021). for the aarmethod, the global median value of 0.58 was initially used (rea, 2009; oien et al., 2021), but elas were also calculated for ratios of 0.5, 0.65, and 0.7 to test for the sensitivity of reconstructed elas on the choice of different aars. to facilitate paleoclimate interpretations, present rettig l. et al. fig. 3 mean summer air temperature (msat) at canin (19612020), baldas (mount resettum) and malga valine (mount raut) (2010-2020) from colucci and guglielmin (2015) and www.meteo.fvg.it (last accessed, july 9th 2021). the data demonstrated the close statistical correlation between the three records. 280 the pleistocene evolution of the silisia valley and mount raut (carnic prealps) day temperature and precipitation in the study area were reconstructed first. this included the 1961-2000 map in barcis and the 2010-2020 mean summer air temperature (msat) at the local weather stations of malga valine-mount rest (1346 m) and baldass-mount resettum (1817 m), the latter located ca. 6 km to the west of mount raut (for location of weather stations see fig. 1). in order to obtain a msat for the climatic period 1961-1990, the values from the local weather stations were then corrected using the canin record from colucci & guglielmin (2015). this was possible, as the correlation between temperatures at the local weather stations and the canin is statistically significant (for baldass r=0.95 and for malga valine r=0.87; fig. 3). the calculated 2010-2020 msat at canin is 2.2°c higher than the average between 1961 and 1990, therefore this value was added to the 2010-2020 msat of baldass and malga valine to obtain the 1961-1990 value. the results from elas calculation were then used to reconstruct the paleoclimatic conditions during the lgm and late glacial stadials. at first, paleoprecipitation was assumed to be equal to present-day records and summer temperatures at the ela were calculated using the following equation from ohmura & boettcher (2018): pa =5.87 tsum² + 230 tsum + 966 (1) s.e. =648 mm where pa is annual precipitation (mm) and tsum is summer (jja) air temperature (°c). applying a summer environmental lapse rate of 0.65°c 100 1 m, representative for the greater alpine region (rolland, 2003; rubel et al., 2017), we calculated the temperature differences from the modern local weather stations. this procedure was equally repeated for different precipitation scenarios, ranging from -30% to +30% of the present-day value. when comparing elas of paleoglaciers to present climatic conditions, all calculated values were assumed to represent environmental elas (envela; žebre et al., 2020). the envela is the theoretical altitude at which a glacier can form and does not consider the effects of shading, avalanching, snow drifting, glacier geometry or debris-cover (anderson et al., 2018). in the alps it was found to be ~75-150 m higher than the regional effective ela (effela; žebre et al., 2020), which accounts for these topographic effects when averaged over a longer climatic period (e.g., 15-30 years). 4. the pleistocene deposits in the silisia valley along the silisia valley, and on the northern side of mount raut, pleistocene deposits are scattered; they can be lithologically grouped into breccias, gravels, conglomerates and diamictons. some of the deposits recorded in the old geological map (zenari, 1929) are presently drowned by the ca’ selva lake. many outcrops are visible along road cuts. an overview about the areas mentioned in the description and the location of the deposits is given in a photograph in fig. 4a and in a cross-profile through the silisia valley (fig. 5). 4.1. breccias, gravels and conglomerates conglomerates are located in several sectors of the valley. the cementation of these deposits is strong and some of them show karstic dissolution structures (fig. 4b). the conglomerates are made of clastsupported gravels, crudely bedded to horizontally bedded, and characterized by sub-rounded clasts of limestones, dolostones and cherts (red and black), pointing to a provenance from the upper catchment of the silisia valley. lateral interfingering with angular breccias is visible and suggests the occurrence of local alluvial or talus deposits. conglomerates mainly crop out in three locations: chiavalot, sarazin ridge, and selva (see figs. 2, 4a and 5). in the chiavalot area, conglomerates are about 40 m thick, with the basal boundary on the bedrock at 900-910 m, and the rim of the chiavalot cliff at 950 m, around 400 m above the lake. the deposits are karstified and deeply cut by local stream incisions. on the sarazin ridge, the conglomerate and breccias are visible along the roadcut (fig. 4c), clasts of conglomerates (i.e., the unit preserved at chiavalot) are included indicating the erosion of an older conglomerate body. the topmost conglomerates are at 775 m and the basal boundary can be observed at ca. 670 m, suggesting the presence of a former valley fill with an overall thickness of around 100 m. the breccia/conglomerate body is locally weakly cemented and intersected by several joints that can be likely ascribed to tectonic activity. similar deformed breccias are located at about 610 m, along the main road at the southern side of the lake. a small outcrop of conglomerates is located on the southern tip of the ridge separating the village of selva from the valley gorge downstream of the dam (fig. 2). this deposit is only a few meters thick and lays on top of the bedrock on the western slope of the ridge. upstream the present lake, at stua, a succession of gravels and sandy gravels crops out (d’agostina, 2010); these are bedded and gently inclined (10-20°) downstream and show a thickness of about 10 m. they are interpreted as related to a fan delta body. 4.2. diamictons along the road flanking the southern side of the ca’ selva lake, sub-rounded boulders are common and outcrops of diamicton, matrix-supported, with striated clasts occur frequently. clasts are sub-angular to subrounded and clast petrography is mostly made of dolostones and limestones, with angular chert clasts (red and black). because of their sedimentary properties, these deposits were ascribed to glacial deposition. in detail, the westernmost outcrop of these diamictons along the lake corresponds to the moraine of case val bassa at the elevation of 520 m. the moraine ridge is ca. 300 m long and located on the left side of the valley outlet between elevations 575 m and 500 m. it contains mostly sub-angular to sub-rounded, large dolostone and limestone boulders, few of which show striations. the overall thickness of the deposit is about 25 m. a similar diamicton crops out at the outlet of the basson valley at an elevation of ca. 500 m (fig. 4e). it is also associated to a left lateral moraine, that is well preserved close to the lake and partly covered by talus. the right moraine flank has been remodelled and a cluster of 281 rettig l. et al. fig. 4 plate of pictures taken during field work. a. view across the lake ca’ selva towards the valley mouths of the valine (in the foreground), basson and bassa (hidden). visible are also the chiavalot cliff and the sarazin ridge, two locations at which thick conglomerate bodies are cropping out. b. strongly cemented conglomerate from the chiavalot. c. stratified conglomerated along the roadcut at the sarazin ridge. d. the glacial diamicton at case staleros. e. glacial diamicton at the mouth of the basson valley. f. view towards the upper valine catchment and the malga valine, where the terminal moraine is marked by red dashed line. g. the terminal moraine ridges at casera valine with a large limestone erratic in the foreground situated on the moraine crest. h. fluted moraines in the upper valine catchment. 282 big boulders is now partially drowned by the lake (d’agostina, 2010). as well, in the lower reach of the valine valley, matrix-supported diamicton, with big boulders and mostly sub-angular to sub-rounded dolostone and limestone clasts, crops out close to the sarazin ridge, at about 600 m. here, however, it is not associated to a clear landform, as it is the case for the outlets of basson and bassa valleys outlets. a thick unit of diamicton is located at case staleros, east of the ca’ selva dam, where it lays on top of the bedrock at an elevation of 530 m. it consists of matrix-supported diamicton, embedding big boulders and striated clasts (fig. 4d). clasts are angular to subrounded; clast petrography indicates dominant dolostones and limestones (mostly sub-rounded), with minor amounts of cherts. the matrix is sandy and the deposit is normally consolidated and weakly and spotty cemented. the visible thickness of the deposit is about 25 m and it is associated to the moraine ridge of stavoli staleros. downstream from this moraine along the silisia valley, no glacial deposits have been observed. several clusters of moraine ridges can also be recognized in the upper sectors of the basson and valine narrow valleys. a wide set of arch-shaped terminal moraines, up to 5 m high, is located in the valine valley at casera valine (1330 m) and forms a large flat area on the back (fig. 4f and 4g). the moraines are made of diamicton, mostly characterized by angular/ subangular boulders in a sandy matrix. on the back of the frontal moraines two longitudinal ridges made of boulders can be ascribed to fluted moraines on the base of their downvalley elongated morphology (fig. 4h). in the basson valley, ending with the mount raut headwall, two separated sets of moraines can be distinguished. the first set is located at 1050 m and consists of mainly of lateral moraines, while the frontal moraines are flat and have been reshaped by local drainage. the second set of moraines is located upstream in the valley between 1425 and 1600 m. these moraines are elongated lateral ridges, while the frontal sector is characterized by scattered boulders in a flat area at about 1400 m. 5. glacier reconstructions given the abundance of glacial landforms and sediments containing clast lithologies of local provenance, it can be concluded that the northern side of mount raut was covered by a glacial system that remained independent from the alpine glacier network. no dating is available for these glacial features. nevertheless, it is possible to attribute them to glacial advances during the last glacial maximum and subsequent late glacial stages, considering the absence of deep weathering and cementation that would typically characterize sediments related to prior glaciations. the only exception is the diamicton at stavoli staleros, which is interpreted as a pre-lgm glacial deposit. this is both due to its sedimentary properties (i.e., spotty cementation) and its overall position in the valley system, more than 150 m high above the present course of the silisia stream (see figs. 4a and 5). an interpretation of the staleros moraine as an lgm ice-front would require both exceedingly thick ice in the silisia valley and extremely high postglacial erosion rates, both of which are not compatible with field evidence and glacier modeling. the lgm glacial network was therefore reconstructed basing on the presence of glacial deposits and frontal moraines that are present at the outlets of the bassa, basson and valine valleys. detailed information on the reconstructed glaciers, including calculated elas for the lgm and late glacial stadials is presented in tab. 1. the elas calculated for aabrs of 1.56 and 1.29 do not show large differences, and are within the error range generally expected for ela reconstructions (oien et al., 2021). there is also a good agreement with the calculations using an aar value of 0.65, while the global median of 0.58 results in slightly higher elas. although for the smaller late glacial stages also aar values of 0.5 and 0.7 yield reasonable estimates, a change in these ratios for the lgm results in a large shift of the calculated ela (aar 0.5 =1480 m; aar 0.7 =1140 m). this is likely due to the particular hypsometry of the mount raut glacier during the lgm, with very steep and narrow valleys present in proximity to the ela. because of these potential complications, all elas in the following the pleistocene evolution of the silisia valley and mount raut (carnic prealps) fig. 5 cross-profile through the silisia valley including the major side valleys and sedimentary units discussed in the text. for the location of the profile see fig. 1. 283 284 rettig l. et al. paragraphs and in the climatic interpretations are reported using the aabr-method with the global median value of 1.56 (oien et al., 2021). 5.1. the mount raut glacier during the last glacial maximum during the lgm, the glacial system of the mount raut had an ela of 1260 m and covered an area of approximately 7 km2 with glacier tongues extending into all three main valleys on its northern side (fig. 6). ice was accumulating on the high-altitude plateaus of the basson and valine catchments up to an altitude of ca. 2030 m. a smaller accumulation area was also located at the head of the bassa valley, although this tributary probably received part of its ice through transfluence from the neighboring basson catchment. from the plateaus, the ice was flowing northwards, constrained within the narrow glacial valleys. in the bassa valley, the maximum ice extent during the lgm is clearly delineated by a frontal moraine ridge, situated at an altitude of 520 m, indicating that the glacier advance stopped just before reaching the e-w trending silisia valley. in contrast, the glacier tongue coming from the basson valley advanced further downstream, as shown by the presence of glacial diamicton and scattered boulders around the flat valley mouth. the larger extent of this tributary can be explained both by the high elevations of the basson plateau, and by the fact that it received additional input from the valine catchment further downstream. the infilling of the valley mouth with glacier ice likely led to a damming fig. 6 the reconstructed glacial system of mount raut during the lgm (ela =1260 m). of the silisia stream, a hypothesis which is corroborated by the presence of fan delta deposits further upstream (d’agostina, 2010). in the lower valine valley, clear geomorphological evidence in the form of a frontal moraine is lacking. however, scattered occurrence of glacial deposits and large boulders at an altitude of 500-600 m suggests that also this tongue extended down towards the valley mouth. the frontal moraine system of this lobe might presently be covered by the ca’ selva lake or, alternatively, might have already been eroded by the silisia stream before the construction of the dam. in addition, a smaller lgm glacier developed in the cirque northwest of mount rodolino (fig. 6), which remained independent from the mount raut glacial system. however, no clear indication of its frontal position was found, which is at least partly due to the steepness of the terrain in this area. 5.2. the valine and basson glaciers during the late glacial after the lgm, the glaciers of the mount raut retreated into the higher parts of their catchments. evidence for phases of glacier stabilization or re-advance during this time can be found as series of moraines both in the valine and the basson valleys. in the valine valley, several well-defined moraine ridges are located at an elevation of around 1330 m, delimiting a small glacier (surface area of ca. 0.9 km²) with an ela of 1570 m (fig. 7a). due to its higher catchment, the basson glacier must have still had a larger extent during this time, with its front potentially stabilizing at an altitude of ca. 1050 m. although patches of glacial deposits and moraine ridges were found here in a lateral position, an evident frontal system is lacking, and it is not clear if these deposits relate to a distinct late glacial advance or can be ascribed to the downwasting of the lgm glacier. conversely, in the basson valley a second set of moraines can be found stretching down to an altitude of ca. 1400 m, indicating a later phase of glacier stabilization during the late glacial. the basson glacier reconstructed for this stage covered an area of ca. 1.2 km2 and its ela was calculated at 1740 m (fig. 7b). at the same time, the glacier in the valine must have almost entirely disappeared or was preserved only as a small niche glacier or firn field, which could also explain the absence of depositional features on the upper valine plateau. 6. discussion 6.1. the pleistocene evolution of the silisia valley and the mount raut paleoglaciers the southern sector of the meduna catchment has been affected by important drainage changes since the messinian, and during the pleistocene, several alluvial sedimentary units were deposited in the lower reach of the valley (monegato & poli, 2015). the tectonic evolution of the south-eastern alps (poli et al., 2009, 2021) has driven these changes. in this perspective, it can be assumed that also the two conglomerate units, at chiavalot and sarazin, are linked to the evolution of the silisia valley and the ongoing incision and infill during plio(?)-pleistocene time. the differences in cementation and weathering degree, also considering the presence of conglomerate pebbles in the sarazin body, then point to different sedimentation of these units in events that pre-date the last sedimentation phase related to the lgm and late glacial. considering the difference in elevation between chiavalot and sarazin of more than 200 m, and the location of the chiavalot in the footwall of the silisia thrust, the progressive incision of the silisia stream probably felt the effect of the general uplift in this sector of the carnic prealps, which is related to the frontal thrusts of the eastern southalpine south-eastern alpine chain (poli et al., 2009, 2021). in this respect, the silisia valley and the mount raut lie on the hanging wall of the periadriatic thrust (carulli et al., 2000), while the lower meduna valley sedimentary stack is located between the periadriatic thrust and the m. jouf-maniago thrust system. three tectonic phases were described in the frontal sector of the carnic prealps (caputo et al., 2010; monegato & poli, 2015), pointing to a potential enhancement of fluvial incision during uplift phases, especially along the major cataclastic belts related to the tectonic structures. the infilling phases of such narrow tributary valleys can be ascribed to glacial damming or 285 the pleistocene evolution of the silisia valley and mount raut (carnic prealps) tab. 1 characteristics of the reconstructed glaciers on the northern side of mount raut for the lgm and two late glacial stages, including elas calculated for several aabrs and aars. in red, hypothetical reconstructions due to lack of geomorphological evidence landslide damming. in this perspective, the chiavalot unit represents the oldest sedimentary infill of the valley, which can be linked to the karstified conglomerates of the lower meduna valley (monegato & poli, 2015). the deepening of the valley of about 200 m occurred before the deposition of the sarazin unit and suggests that an uplift phase likely took place in the lower pleistocene. the difference in elevation of about 170 m from the basal boundary of the sarazin unit to the lgm deposits also indicates this post-depositional uplift. this influenced the deep incision downstream of the dam, which led to the abandonment of the path through selva and the preservation of the glacigenic deposits of staleros. a similar deepening characterizes also the meduna valley, which was later filled by lacustrine deposits (venzo et al., 1975; cavallin & martinis, 1981). the staleros unit itself can most likely be ascribed to a middle pleistocene ice advance, even if no chronological data are available. in the lower meduna valley, old alluvial terraces (monegato & poli, 2015) may represent its outwash deposition. during the lgm, glaciers in the valine, basson and bassa catchments advanced for the last time beyond their valley mouths, leading to the deposition of frontal moraines and glacial sediments and at least temporarily to a damming of the silisia valley upstream. the well-preserved fluvial terraces of faidona (cavallin & martinis, 1981), at the confluence with the meduna valley, can probably be ascribed to deposition by meltwaters originating from the glacial system during this time. from the position of the moraine ridges, however, it can clearly be established that the raut paleoglacier itself never merged with the glacial system of the meduna valley, as it was sometimes reported in previous studies (gortani, 1959; ehlers & gibbard, 2004). regionally, the first culmination of the lgm advance has been dated to around 26.5 to 23 cal ka bp, with a later pulse occurring at 22 cal ka bp (tagliamento endmoraine system, monegato et al., 2007; fontana et al., 2014). this later stage also corresponds to the phase of maximum aggradation in the meduna alluvial fan (avigliano et al., 2002). although no numerical dating is available for the mount raut, we hypothesize that the advance of the glacial system during the lgm probably took place during the same time span, considering the similar climatic setting to the meduna and tagliamento catchments. following the downwasting of the lgm glaciers, two distinct advances of the basson and valine valley glaciers occurred during the late glacial. such stages of stabilization have been equally recognized in parts of the carnic alps and julian prealps (discenza, 2004; colucci et al., 2014) and the chiampon-cuel di lanis ridge (monegato, 2012). in the latter case, these glaciers exhibit an ela ca. 250 to 350 m higher with respect to the lgm, which matches the calculations for late glacial stage 1 (lg1) in the valine (ela raising of ca. 330 m). even if this may point to a common climatic driver for the glacier advance, a detailed chronology for the ice -decay in the south-eastern alps is still lacking, which hampers comparisons between different mountain ranges or a correlation to one of the established late glacial stadials in other sectors of the alps (e.g., ivy-ochs et al., 2008). rettig l. et al. fig. 7 the valine and basson glaciers during the late glacial. a. late glacial stage 1 (ela =1570 m). b. late glacial stage 2 (ela =1740 m). 286 several small mountain glaciers remained independent from the large alpine ice-streams throughout the late pleistocene cold phases, including the last glacial maximum, one of which was located on the northern side of mount raut (carnic prealps, ne italy). the reconstruction of these glaciers and their elas reveals important information about the past climate. our investigation shows that the lgm glacial system of the mount raut covered an area of ca. 7 km². its ela (aabr) was calculated at 1260 m. assuming levels of precipitation similar to today, an lgm msat depression of 8.5 or 9.4°c (� =±2.2°c) was calculated in re6.2. paleoclimate reconstructions the calculated ela of 1260 m for the lgm glacial system is among the lowest reported for the southern fringe of the alps so far. it corresponds best with those calculated from other areas in the south-eastern part of the range, such as the julian prealps (elas =11281190 m, monegato, 2012), or the trnovski gozd in the slovenian dinaric mountains (ela =1240, žebre et al., 2014). already at mount grappa, ca. 75 km further west, elas are reported to be around 150-200 m higher than at mount raut (carraro & sauro, 1979; baratto et al., 2003). the values increase even further towards the central southern alps (ela =1535 m; forno et al., 2010) or the maritime alps (ela =1850 m; federici et al., 2012), indicating that an east-west ela-gradient probably prevailed along the southern fringe of the alps during the lgm. present (2010-2020) msat in baldass and malga valine, which are closer in respect to the pala d’altei station, are at 12.6°c and 14.8°c, respectively. given the ela of 1260 m, and assuming present-day precipitation, our calculations suggest that, compared to the period 1961-1990, msat in the mount raut area was depressed by around 9.4°c or 8.5°c during the lgm, by 7.1 or 6.2 °c during the lg1, and by 6.1 or 5.3°c during the lg2, respectively (� =±2.2°c). the results for the lgm are consistent with regional models of atmospheric circulation (kuhlemann et al., 2008) and also with chironomid-based july temperatures reconstructed at lago della costa (euganean hills, samartin et al., 2016). with different precipitation scenarios (±30% of the present-day value, see tab. 2, 3, 4), msat depressions vary between 6.2°c (7.0°c, respectively) and 11.6°c (10.8°c, respectively). with a further reduction in precipitation, reconstructed temperatures are not compatible anymore with the aforementioned calculations from other proxies. this indicates that the lgm climate in the south-eastern alps was very likely characterized by high precipitation throughout the whole lgm. these high amounts of precipitation, especially during autumn and winter (spötl et al., 2021), allowed glaciers to expand to lower elevations as in other parts of the southern alps and today it still ensures the preservation of very small glaciers in parts of the carnic and julian alps (colucci et al., 2021). 7. conclusion new evidence for the pleistocene evolution of mount raut and the neighboring silisia valley is presented in this study, basing on mapping and description of quaternary sediments and landforms. detailed studies concerning the quaternary deposits and landforms in the area were previously still lacking. two bodies of conglomerates were found and they have been related to the recurring infill and incision of the silisia valley during plio(?)-pleistocene times, probably driven partly by climatic fluctuations and partly by tectonic uplift phases of the south-eastern alps. series of moraine ridges and glacigenic deposits are mainly related to glacier advances during the lgm and following late glacial stages. in the south-eastern part of the european alps, the pleistocene evolution of the silisia valley and mount raut (carnic prealps) tab. 4 msat depression calculated for the late glacial stage 2, assuming different map scenarios. tab. 2 msat depression calculated for the lgm, assuming different map scenarios. tab. 3 msat depression calculated for the late glacial stage 1, assuming different map scenarios. 287 spect to two recent (1960-1990) climatic records in the area. during the late glacial, glaciers were confined in the upper parts of their catchments, intermitted by two distinct phases of glacier stabilization, the first at which glaciers had an ela of 1590 m (corresponding to an msat lowering of 6.2 or 7.1°c) and the second with an ela of 1740 m (msat lowering of 5.3 or 6.1°c). these calculations are generally in line with regional circulation models, indicating that glaciers in the south-eastern alps received high amounts of precipitation throughout the lgm. however, further research is needed to better understand the paleoclimatic evolution in the south-eastern alps during the last glacial cycle, by integrating glacier-based climate reconstructions with numerical dating methods to better constrain the lgm and late glacial advances. acknowledgements we want to thank g. marcato and m. spagnolo for discussions and input, the forestal service of region fvg for access permissions of the area. the reviews provided by a. ribolini and h. kerschner greatly improved our manuscript. we also thank a. fontana (a.e.) for his comments. references anderson r.s., anderson l.s., armstrong w.h., rossi m.w., crump s.e. (2018) glaciation of alpine valleys: the glacier debris-covered glacier rock glacier continuum. geomorphology, 311, 127-142. doi: 10.1016/j.geomorph.2018.03.015 avigliano r., calderoni g., monegato g., mozzi p. (2002) the late pleistocene-holocene evolution of the cellina and meduna alluvial fans (friuli, ne italy). memorie società geologica italiana, 57, 133 -139. bacon s.n., chinn t.j., van dissen r.j., tillinghast s.f., goldstein h.l., burke r.m. (2001) paleo equilibrium line altitude estimates from late quaternary glacial features in the inland kaikoura range, south island, new zealand. new zealand journal of geology and geophysics, 44(1), 55-67. doi: 10.1080/00288306.2001.9514922 baratto a., ferrarese f., meneghel m., sauro u. (2003) la ricostruzione della glaciazione wurmiana nel gruppo del monte grappa (prealpi venete). in: risposta dei processi geomorfologici alle variazioni ambientali. (ed. by biancotti a., motta m.). brigati g., genova, 67-77. beniston m. (2005) mountain climates and climatic change: an overview of processes focusing on the european alps. pure and applied geophysics, 162, 1587-1606. doi: 0.1007/s00024-005-2684-9 beniston m. (2006) mountain weather and climate: a general overview and a focus on climatic change in the alps. hydrobiologia, 562, 3-16. doi: 10.1007/s10750-005-1802-0 benn d.i., hulton n.r.j. (2010) an exceltm spreadsheet program for reconstructing the surface profile of former mountain glaciers and ice caps. computers & geosciences, 36(5), 605-610. doi: 10.1016/j.cageo.2009.09.016 brædstrup c.f., egholm d.l., ugelvig s.v., pedersen v.k. (2016) basal shear stress under alpine glaciers: insights from experiments using the isosia and elmer/ice models. earth surface dynamics, 4 (1), 159-174. doi: 10.5194/esurf-4-159-2016 caputo r., poli m.e., zanferrari a. (2010) neogenequaternary tectonic stratigraphy of the eastern southern alps, ne italy. journal of structural geology, 32(7), 1009-1027. doi: 10.1016/j.jsg.2010.06.004 carraro f., polino r. (1976) vistose deformazioni in depositi fluvio-lacustri quaternari a ponte racli (valle del t. meduna prov. di pordenone). quaderni gruppo di studio quaternario padano, 3, 7788. carraro f., sauro u. (1979) il glacialismo “locale” wurmiano del massiccio del grappa (provincie di treviso e di vicenza). geografia fisica e dinamica quaternaria, 2(1), 6-16. carulli g.b., cozzi a., longo salvador g., pernarcic e., podda f., ponton m. (2000) geologia delle prealpi carniche. with enclosed carta geologica delle prealpi carniche, scala 1:50.000. pubbl. no 44, edizioni museo friulano storia naturale, udine, 47 pp. carulli g.b., podda f., venturini c., zanferrari a., cucchi f., monegato g., nicolich r., paiero g., piano c., slejko d., tunis g., zanolla c. (2006) carta geologica del friuli venezia giulia (scala 1:150.000). edizioni s.el.ca., firenze. castiglioni b. (1940) l’italia nell’età quaternaria. carta alla scala 1:200.000. atlante fisico-economico d’italia, tci, milano. castiglioni g.b. (2004) quaternary glaciations in the eastern sector of the italian alps. in: quaternary glaciations extent and chronology-part i: europe (ed. by ehlers j., gibbard p.l.). elsevier, 209-215. cavallin a., martinis b. (1981) il bacino lacustre della conca di tramonti (prealpi carniche). alto, 63, 117. clark c.d., chiverrell r.c., fabel d., hindmarsh r.c.a., ó cofaigh c., scourse j.d. (2021) timing, pace and controls on ice sheet retreat: an introduction to the britice chrono transect reconstructions of the british-irish ice sheet. journal of quaternary science, 36(5), 673-680. doi: 10.1002/jqs.3326 colucci r.r., monegato g., žebre m. (2014) glacial and proglacial deposits of the resia valley (ne italy): new insights on the onset and decay of the last alpine glacial maximum in the julian alps. alpine and mediterranean quaternary, 27(2), 85104. colucci r.r., guglielmin m. (2015) precipitationtemperature changes and evolution of a small glacier in the southeastern european alps during the last 90 years. international journal of climatology, 35(10), 2783-2797. doi: 10.1002/joc.4172 colucci r.r., žebre m., torma c.z., glasser n.f., maset e., del gobbo c., pillon s. (2021) recent rettig l. et al. increases in winter snowfall provide resilience to very small glaciers in the julian alps, europe. atmosphere, 12(2), 263. doi: 10.3390/atmos12020263 crespi a., brunetti m., lentini g., maugeri m. (2018) 1961-1990 high-resolution monthly precipitation climatologies for italy. international journal of climatology, 38(2), 878-895. doi: 10.1002/joc.5217 cucato m. (2007) la successione continentale pliocenico?-quaternaria. in: note illustrative della carta geologica d’italia alla scala 1:50.000: foglio 082 “asiago” (ed. by barbieri, g., grandesso, p.). apat e dipartimento difesa del suolo e servizio geologico d’italia, roma, italia, pp. 60-94. d’agostina n. (2010) stima dell’interramento di un bacino artificiale mediante l’utilizzo del modello multiparametrico gavrilovich-zemlich. tesi di laurea inedita, università degli studi di trieste, 101 pp. dal piaz g.v., bistacchi a., massironi m. (2003) geological outline of the alps. episodes, 26/3, 174179. discenza k. (2004) evoluzione tardo quaternaria delle alpi meridionali orientali. tesi di dottorato di ricerca, università di bologna. ehlers j., gibbard p. l. (2004) quaternary glaciationsextent and chronology: part i: europe. elsevier, amsterdam. federici p.r., granger d.e., ribolini a., spagnolo m., pappalardo m., cyr a.j. (2012) last glacial maximum and the gschnitz stadial in the maritime alps according to 10be cosmogenic dating. boreas, 41 (2), 277-291. doi: 10.1111/j.1502-3885.2011.00233.x fontana a., monegato g., devoto s., zavagno e., burla i., cucchi f. (2014) evolution of an alpine glaciofluvial system at the lgm decay: the cormor megafan (ne italy). geomorphology, 204, 136-153. doi: 10.1016/j.geomorph.2013.07.034 forno m.g., gianotti f., racca g. (2010) significato paleoclimatico dei rapporti tra il glacialismo principale e quello tributario nella bassa valle della dora baltea. il quaternario, 23(1), 105-124. gortani m. (1959) carta della glaciazione würmiana in friuli. rendiconti atti della accademia delle scienze dell'istituto di bologna, 11(6), 1-11. hofmann f.m., alexanderson h., schoeneich p., mertes j.r., léanni l. (2019) post-last glacial maximum glacier fluctuations in the southern écrins massif (westernmost alps): insights from 10be cosmic ray exposure dating. boreas, 48(4), 10191041. doi: 10.1111/bor.12405 hughes a.l.c., gyllencreutz r., lohne ø.s., mangerud j., svendsen j.i. (2016) the last eurasian ice sheets-a chronological database and time slice reconstruction, dated-1. boreas, 45(1), 1-45. doi: 10.1111/bor.12142 isotta f.a., frei c., weilguni v., tadić m.p., lassègues p., rudolf b., pavan v., cacciamani c., antolini g., ratto s.m., munari m., micheletti s., bonati v., lussana c., ronchi c., panettieri e., marigo g., vertačnik g. (2014) the climate of daily precipitation in the alps: development and analysis of a high resolution grid dataset from pan-alpine raingauge data. international journal of climatology, 34, 1657-1675. doi: 10.1002/joc.3794 iverson n.r., cohen d., hooyer t.s., fischer u.h., jackson m., moore p.l., lappegard g., kohler j. (2003) effects of basal debris on glacier flow. science, 301(5629), 81-84. doi: 10.1126/science.1083086 ivy-ochs s., kerschner h., reuther a., preusser f., heine k., maisch m., kubik p.w., schlüchter c. (2008) chronology of the last glacial cycle in the european alps. journal of quaternary science, 23, 559-573. doi: 10.1002/jqs.1202 ivy-ochs s., monegato g., reitner j.m. (2021) glacial landscapes of the alps. in: european glacial landscapes: maximum extent of glaciations (ed. by palacios d., hughes p.d., garcía ruiz j.m., de andrés n.). elsevier, amsterdam, 115-121. jouvet g., seguinot j., ivy-ochs s., funk m. (2017) modelling the diversion of erratic boulders by the valais glacier during the last glacial maximum. journal of glaciology, 63, 487-498. doi: 10.1017/jog.2017.7 kuhlemann j., rohling e.j., krumrei i., kubik p., ivy-ochs s., kucera m. (2008) regional synthesis of mediterranean atmospheric circulation during the last glacial maximum. science, 321 (5894), 1338-1340. doi: 10.1126/science.1157638 monegato g., ravazzi c., donegana m., pini r., calderoni g., wick l. (2007) evidence of a twofold glacial advance during the last glacial maximum in the tagliamento end moraine system (eastern alps). quaternary research, 68(2), 284302. doi: 10.1016/j.yqres.2007.07.002 monegato g. (2012) local glaciers in the julian prealps (ne italy) during the last glacial maximum. alpine and mediterranean quaternary, 25(1), 5-14. monegato g., poli m.e. (2015) tectonic and climatic inferences from the terrace staircase in the meduna valley, eastern southern alps, ne italy. quaternary research, 83(1), 229-242. doi: 10.1016/j.yqres.2014.10.001 nye j.f. (1952) the mechanics of glacier flow. journal of glaciology, 2, 82-93. doi: 10.3189/s0022143000033967 ohmura a., boettcher m. (2018) climate on the equilibrium line altitudes of glaciers: theoretical background behind ahlmann's p/t diagram. journal of glaciology, 64(245), 489-505. doi: 10.1017/jog.2018.41 oien r.p., rea b.r., spagnolo m., barr i.d., bingham r.g. (2021) testing the area-altitude balance ratio (aabr) and accumulation-area ratio (aar) methods of calculating glacier equilibrium-line altitudes. journal of glaciology. doi: https://doi.org/10.1017/jog.2021.100 paterson w.s.b. (1994) the physics of glaciers: 3rd the pleistocene evolution of the silisia valley and mount raut (carnic prealps) edition. pergamon, new york, pp. 480. pellitero r., rea b.r., spagnolo m., bakke j., hughes p., ivy-ochs s., lukas s., ribolini a. (2015) a gis tool for automatic calculation of glacier equilibrium-line altitudes. computers & geosciences, 82, 55-62. doi: 10.1016/j.cageo.2015.05.005 pellitero r., rea b.r., spagnolo m., bakke j., ivy-ochs s., frew c.r., hughes p., ribolini a., lukas s., renssen h. (2016) glare, a gis tool to reconstruct the 3d surface of palaeoglaciers. computers & geosciences, 94, 77-85. doi: 10.1016/j.cageo.2016.06.008 penck a., brückner e. (1901-1909) die alpen im eiszeitalter. tauchnitz, leipzig, germany, pp. 1199. poli m.e., zanferrari a., monegato g. (2009) geometria, cinematica e attività pliocenico-quaternaria del sistema di sovrascorrimenti arba-ragogna (alpi meridionali orientali, italia ne). rendiconti online della società geologica italiana, 5, 172-175. poli m.e., falcucci e., gori s., monegato g., zanferrari a., affatato a., baradello l., bohm g., dal bo i., forte e., grimaz s., marchesini a. (2021) paleoseismological evidence for historical ruptures along the meduno thrust (eastern southern alps, ne italy). tectonophysics, 818, 229071. doi: 10.1016/j.tecto.2021.229071 rea b.r. (2009) defining modern day area-altitude balance ratios (aabrs) and their use in glacierclimate reconstructions. quaternary science reviews, 28(3-4), 237-248. doi: 10.1016/j.quascirev.2008.10.011 rea b.r., pellitero r., spagnolo m., hughes p., ivy-ochs s., renssen h., ribolini a., bakke j., lukas s., braithwaite r.j. (2020) atmospheric circulation over europe during the younger dryas. science advances, 6(50), eaba4844. doi: 10.1126/sciadv.aba4844 rolland c. (2003) spatial and seasonal variations of air temperature lapse rates in alpine regions. journal of climate, 16(7), 1032-1046. doi: 10.1175/1520-0442(2003)016<1032:sasvoa >2.0.co;2 rubel f., brugger k., haslinger k., auer i. (2017) the climate of the european alps: shift of very high resolution köppen-geiger climate zones 18002100. meteorologische zeitschrift, 26(2), 115-125. doi: 10.1127/metz/2016/0816 samartin s., heiri o., kaltenrieder p., kühl n., tinner w. (2016) reconstruction of full glacial environments and summer temperatures from lago della costa, a refugial site in northern italy. quaternary science reviews, 143, 107-119. doi: 10.1016/j.quascirev.2016.04.005 seguinot j., ivy-ochs s., jouvet g., huss m., funk m., preusser f. (2018) modelling last glacial cycle ice dynamics in the alps. the cryosphere, 12(10), 3265-3285. doi: 10.5194/tc-12-3265-2018 spagnolo m., ribolini a. (2019) glacier extent and climate in the maritime alps during the younger dryas. palaeogeography, palaeoclimatology, palaeoecology, 536, 109400. doi: 10.1016/j.palaeo.2019.109400 spötl c., koltai g., jarosch a.h., cheng h. (2021) increased autumn and winter precipitation during the last glacial maximum in the european alps. nature communications, 12, 1839. doi: 10.1038/s41467-021-22090-7 thorp p.w. (1991) surface profiles and basal shear stresses of outlet glaciers from a late-glacial mountain ice field in western scotland. journal of glaciology, 37(125), 77-88. doi: 10.3189/s0022143000042829 vai g.b., cantelli, l. (eds.) (2004) lithopalaeoenvironmental maps of italy during the last two climatic extremes. two maps 1:1,000,000. 32° igc publications, lac, bologna. van husen d. (1987) die ostalpen und ihr vorland in der letzten eiszeit (würm). geologische bundesanstalt, vienna. venturini c. (1985) i depositi quaternari di ponte racli (pn, prealpi friulane). gortania, atti museo friulano di storia naturale, 7, 37-58. venturini c., discenza k., astori a. (2013) sedimentologia e tettonica della successione clastica della val meduna (prealpi carniche, pn). gortania, atti museo friulano di storia naturale, 34, 51-78. venzo g.a., ulcigrai f., cucchi f. (1975) studio geologico per i serbatoi di laminazione delle piene sul t. meduna a la clevata e a colle. studi trentini di scienze naturali sez. a, 52, 201-221. višnjević v., herman f., prasicek g. (2020) climatic patterns over the european alps during the lgm derived from inversion of the paleo-ice extent. earth and planetary science letters, 538, 116185. doi: 10.1016/j.epsl.2020.116185 žebre m., stepišnik u., kodelja b. (2014) traces of pleistocene glaciation on trnovski gozd. dela, 39, 157-170. žebre m., colucci r.r., giorgi f., glasser n.f., racoviteanu a.e., del gobbo c. (2021) 200 years of equilibrium-line altitude variability across the european alps (1901-2100). climate dynamics, 56(3), 1183-1201. doi: 10.1007/s00382-020-05525-7 zenari s. (1929) note illustrative della carta geologica delle tre venezie foglio “maniago”. ufficio idrografico regio magistrato acque di venezia, padova. rettig l. et al. ms. received: july 16, 2021 revised: october 21, 2021 accepted: december 9. 2021 available online: 23 december 2021 290 sess 5_16022011_edi as.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 many palaeoclimate records from the central to eastern mediterranean region suggest a wetter climate during the early to middle holocene compared with the second half of the holocene (e.g. bar-matthews et al., 2000; sadori & narcisi, 2001; roberts et al., 2008). further south in the sahara region, the wettest conditions for the holocene (the so-called “african humid period” e.g. gasse, 2000) were also experienced during the first half of this epoch. at this time, monsoon circulation was enhanced, which led to a substantial increase in nile river discharge. this increase in discharge is considered to be one of the main causes of stagnation in the eastern mediterranean sea, leading to the formation of an organic-rich sapropel layer, s1 (e.g. rossignolstrick et al., 1982). stagnation of the eastern mediterranean may also have been enhanced by increased river discharge derived from local rainfall (e.g. kallel et al., 1997).the degree of synchronicity between the interval of enhanced precipitation throughout the eastern and central mediterranean on the one hand, and sapropel formation on the other hand, has yet to be determined. recent data obtained from caves from apuan alps allow to improve our knowledge on the wettest phase in central mediterranean. a stratigraphic and chronological study of the infilling of the upper level of renella cave reveals that between ca. 9.2 and 7.1 ka there was an increased frequency of flooding in the upper, now inactive, passage, which was particularly severe between ca. 8.2 and 7.1 ka, which left thick layers of sands (zhorniak et al., 2011). this period of enhanced flood activity was substantially in phase evidence for a “pluvial” period between 8-7 ka on apuan alps (central italy): implications for the sapropel paradigm in the eastern mediterranean giovanni zanchetta 1, n. russell drysdale 2, john hellstrom 3, ilaria isola 4, eleonora regattieri 1 & lelya zhoriak 1 1dipartimento di scienze della terra, university of pisa, pisa, italy 2department of resource management and geography, university of melbourne, victoria, australia 3school of earth sciences, university of melbourne, victoria, australia 4instituto nazionale di geofisica e vulcanologia, italy corresponding author: g. zanchetta <zanchetta@dst.unipi.it> abstract: zanchetta et al., evidence for a “pluvial” period between 8-7 ka on apuan alps (central italy): implications for the sapropel paradigm in the eastern mediterranean. (it issn 0394-3356, 2011) a stratigraphic and chronological study of the upper level of renella cave (apuan alps, central italy) reveals that two episodes of flowstone accumulation bracket a thick clastic layer deposited between ca. 8.2 and 7.1 ka. this layer, which represents a period of enhanced cave flooding, is substantially in phase with an interval of depleted oxygen isotopes values previously recorded in a stalagmite from nearby corchia cave, previously interpreted to have resulted from an increase in local precipitation. combined evidence from renella and corchia cave suggests that this wettest phase was shorter than the condition leading to the formation of sapropel s1. a synchronicity between signal dominated by the advection of vapour masses from the atlantic, as corchia and renella archives should record in their proxies, cannot straightforwardly correlated with events (at least in duration) dominated by the monsoon signal as could be sapropels in the mediterranean. riassunto: zanchetta et al., evidenze di un intervallo “pluviale” tra 8-7 ka nelle alpi apuane (italia centrale): implicazioni per il paradigma dei sapropel nel mediterraneo orientale. (it issn 0394-3356, 2011) lo studio stratigrafico e cronologico della galleria superiore della grotta della renella (alpi apuane, italia centrale) ha permesso di individuare due episodi di concrezionamento separate da uno spesso deposito clastico depositosi in un periodo compreso tra circa 8,2 e 7,1 ka. questo livello è interpretabile coem un perido in cui i processi di allagamento e alluvionamento della grotta erano particolarmente frequenti. cronologicamente questo intervallo è in sostanziale accordo con i dati isotopici provenienti dalla vicina cavità carsica del dell’antro del corchia, indicando che in questo periodo si registra un sostanziale incremento delle precipitazioni meteoriche. considerazioni di carattere cronologico suggeriscono che questa fase ad elevate precipitazioni è sostanzialmente più breve delle condizioni che hanno portato alla formazione del sapropel s1 nel mediterraneo orientale. si è quindi portati a pensare che non esiste una perfetta sincronicità tra la fase di elevate precipitazioni registrate sulle apuane, certamente governate da una maggiore advezione di masse di vapore dal nord atlantico e registri dominati dall’effetto delle precipitazioni monsoniche, come il sapropel dovrebbe essere il caso. key words: central mediterranean, climatic changes, holocene parole chiave:mediterraneo centrale, cambiamenti climatici, olocene 221 222 222 ms. received: testo ricevuto il with the interval of lower δ18o values recorded in a stalagmite from nearby corchia cave, inferred to have resulted from an increase in local precipitation (zanchetta et al., 2007). these data reinforce the previous interpretation of oxygen isotopic records from corchia cave and confirm that during this period of time the region experienced wetter conditions but may have also experienced an increase of exceptional storm events capable of producing floods that allowed invasion of the higher passages. the timing of the clastic phase occurred when the eastern mediterranean experienced deposition of sapropel layer s1, which is thought to reflect the stagnation of sea water produced by enhanced flood activity along the nile due to increased monsoon intensity in northern equatorial africa. recent estimates suggest that s1 may have lasted from ca 10.8 to ca 6.1 ka cal bp (de lange et al., 2008). combined evidence from renella and corchia cave suggests that the period corresponding to the wettest phase was shorter than the condition leading to the formation of sapropel s1, and therefore, a synchronicity between signal dominated by the advection of vapour masses from the atlantic, as corchia and renella archives should record in their proxies, probably cannot straightforwardly correlated with events (at least in duration) dominated by the monsoon signal as could be sapropels in the mediterranean. references bar-matthews m., ayalon a. & kaufmann a. (2000) timing and hydrological conditions of sapropel events in the eastern mediterranean, as evident from speleothems, soreq cave, israel. chemical geology, 169, 145–156. de lange g.j., thomson j., reitz a., slomp c.p., speranza principato m., erba e. & corselli c. (2008) synchronous basin-wide formation and redox-controlled preservation of a mediterranean sapropel. nature geoscience, 283, 606-610. gasse f. (2000) hydrological changes in the african tropics since the last glacial maximum. quaternary science reviews, 19, 189–211. kallel n., paterne m., duplessy j.c., vergnaud -grazzini c., pujol c., labeyrie l., arnold m., fontugne m. & pierre c. (1997) enhanced rainfall in the mediterranean region during the last sapropel event. oceanologica acta, 20, 697– 712. roberts n., jones m.d., benkaddur a., eastwood w.j., filippi m.l., frogley m.r., lamb h.f., leng m.j., reed j.m., stein m., stevens l., valero-garcè b. & zanchetta g. (2008) stable isotope records of late quaternary climate and hydrology from mediterranean lakes: the isomed synthesis. quaternary science review, 27, 2426-2441. rossignol-strick m., nesteroff w., olive p. & vergnaud-grazzini c. (1982) after the deluge: mediterranean stagnation and sapropel formation. nature, 295, 105-110. sadori l. & narcisi b. (2001) the postglacial record of environmental history from lago di pergusa. the holocene 11, 655–670. zanchetta g., drysdale r.n., hellstrom j.c., fallick a.e., isola i., gagan m. & pareschi m.t. (2007) enhanced rainfall in the western mediterranean during deposition of sapropel s1: stalagmite evidence from corchia cave (central italy). quaternary science review, 26, 279-286. zhornyak l.v., zanchetta g., drysdale r.n., hellstrom j.c., isola i., regattieri e., piccini l., baneschi i. & couchoud i. (2011) stratigraphic evidence for a “pluvial phase” between ca. 8200-7100 ka from renella cave (central italy). quaternary science review, in press. january 5, 2011 5 gennaio 2011 zanchetta et al. sess 5_16022011_edi as.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 1. introduction the isotopic and trace element compositions of biogenic carbonates have been used for paleoenvironmental and paleoclimate reconstruction for a while for reconstructing temperature, salinity and productivity (e.g. dodd, 1965; mook, 1971; klein et al., 1996). despite late quaternary marine molluscs can be potentially dated with u/th, so offering a robust chronological support to geochemical proxies, the applicability of this method is still a challenge owing to the postmortem migration of uranium into mollusc shells (kaufman et al., 1971; 1996). the selection of well-preserved samples is of paramount importance for obtaining reliable result both in chronology and paleoproxy interpretation. this work investigates the application of trace elements and petrographical analyses as indicator of preservation state for marine shells collected in the quaternary coastal marine deposit of the patagonia atlantic margin. geochemical and petrographical analyses for selecting quaternary marine shells for radiometric dating and paleoclimate reconstructions: examples from patagonia ilaria consoloni1, giovanni zanchetta1,3,6, marina l. aguirre2, ilaria baneschi3, monica bini1, gabriella m. boretto2, luigi dallai3, massimo d’orazio1, anthony e. fallick4, massimo guidi3, john c. hellstrom5, ilaria isola6, enrique fucks2, francesco mazzarini6, marta pappalardo1 & adriano ribolini1 1dipartimento di scienze della terra, università di pisa, pisa, italy 2conicet, ingea unlp, la plata, argentina 3igg-cnr, pisa, italy 4scottish universities environmental research centre, east kilbride, scotland 5school of earth sciences, university of melbourne, australia 6ingv sez. pisa, pisa corresponding author: i. consoloni <consoloni@dst.unipi.it> abstract: consoloni i. et al., geochemical and petrographical analyses for selecting quaternary marine shells for radiometric dating and paleoclimate reconstructions: examples from patagonia. (it issn 0394-3356, 2011) the selection of suitable samples is a fundamental target in order to obtain reliable results in the field of radiometric dating and paleoclimate. marine molluscs are particularly interesting in this respect in what different radiometric methods (e.g. u/th, esr) can be applied coupled with chemical analyses to reconstruct past environment. for this kind of material is imperative that the samples have not undergone any alteration. we present, as example, the study of marine molluscs from quaternary beach ridges from the atlantic patagonian coast. multiproxy analyses show that the degree of weathering is quite variable but not enough for undermining the paleoclimatic values of the stable isotopes content and of some trace element, but enough severe to make problematic the application of u/th dating methods. however, the careful petrographic observation and trace element analyses can support the selection of suitable samples for u/th dating. riassunto: consoloni i. et al., analisi geochimiche e petrografiche per la selezione di conchiglie marine quaternarie per datazioni radiometriche e ricostruzioni paleoclimatiche: esempi dalla patagonia. (it issn 0394-3356, 2011) la scelta di campioni rappresentativi è fondamentale per ottenere risultati affidabili nel campo delle datazioni radiometriche e ricostruzioni paleoclimatiche. questo è particolarmente rilevante quando si vogliano analizzare i resti di molluschi marini che potenzialmente possono essere direttamente datati (per esempio u/th, esr) e sugli stessi campioni possono essere effettuate analisi per ricostruzioni paleoambientali. e’ indispensabile, quindi, che i campioni non abbiano subito alcuna alterazione. in questo lavoro è discusso, a titolo di esempio, lo studio effettuato su dei molluschi marini provenienti dalle formazioni quaternarie marine affioranti sul margine atlantico della patagonia. lo studio comparato di molti proxy geochimici permette di concludere che alcune informazioni paleombientali non sembrano aver subito particolarmente gli effetti dei processi di alterazione subaerea, come la composizione degli isotopi stabili, mentre anche piccoli gradi alterazione rendono difficoltosa l’applicazione del metodo di datazione dell’u/ th. tuttavia, l’attenta selezione, attraverso lo studio petrografico e geochimico, dei campioni ha permesso di ottenere risultati oltremodo incoraggianti. key words: marine molluscs, geochemistry, quaternary, paleoclimate, patagonia, radiometric datings parole chiave: molluschi marini, geochimica, quaternario, paleoclima, patagonia, datazioni radiometriche 208 210 209 2. sampling and methods specimens of upper pleistocene, holocene and modern protothaca antiqua (king, 1832) bivalve shells were selected from s. jorge gulf (patagonia, argentina). protothaca antiqua represents the dominant molluscan species in these deposits. articulated shells were preferred for the analyses to decrease the possibility to collect reworked shells from older beds. one to six whole shells were analysed for each layer. after a careful cleaning, one half valve was powdered for geochemical analyses and the other was used for radiometric dating. the bulk carbonate stable isotopic analyses (δ18o and δ13c) were performed at s.u.e.r.c. (east kilbride, scotland) with the ap2003 mass spectrometer equipped with a separate acid injector system, and at i.g.g. – c.n.r. (pisa) by manual co2 extraction after purification with cryogenic traps. isotopic results were reported using the conventional δ‰ notation relative to vpdb. shells mineralogy was determined by x-ray diffraction (xrd) calibrated with mixture of known quantity of aragonite/calcite ratio. inductively coupled plasma mass spectrometry (icp-ms) was used for trace element measurements. the u/th ages were determined using multicollector inductively coupled plasma mass spectrometry (mc-icp-ms) at the school of earth sciences at the university of melbourne (hellstrom, 2003). 3. discussion and conclusion aragonite, forming the shell of these bivalves, is the least-stable calcium carbonate phase at the earth's surface and is diagenetically easily transformed into low-mg calcite (land, 1967; brand & veizer, 1980; takesue & van geen; 2004). mineralogical results from xrd indicate that the pristine aragonite composition was substantially preserved for all the samples analysed, without any calcite alteration. manganese content in fossil shells is within the variability of modern specimens concentrations. as the continental waters usually contain about 40 time mn than seawater (drever, 1997), this support the nothing of no shell alternations. large variability of isotopic composition of modern shells from different sites of san jorge gulf suggest that variable in salinity and variable dissolved inorganic carbon sources are responsible of this variability. samples of different age collected in different places, suggest different trends in isotopic composition, which can be in te rp re ted as subs tan t ia l d i f fe ren t paleoceanographic conditions. figure 1 illustrates the variation in isotopic composition of shells of different ages from the same area (as examples). this probably can be interpreted as the changes in the relative front position between the warm and fig. 1, isotopic composition of shells of different ages from the same area (camarones north). the bars respresent the variability found on many shells. composizione isotopica di bivalvi di età differente provenienti dalla stessa area (camarones nord). fig. 2, thin section of a modern unaltered shells (a) and a pleistocene altered one (b) (2.5 x magnification) sezione sottile di un bivalve attuale inalterato (a) e uno pleistocenico alterato (b) (ingrandimento 2.5 x) inner layer inner layer outer layer outer layer geochemical and petrographical analyses for selecting ... 0.00 0.50 1.00 1.50 2.00 2.50 3.00 0.00 0.50 1.00 1.50 2.00 2.50 3.00 δ 18 o v pd b δ13c vpdb modern late holocene (915 yr bp) early holocene (6365 yr bp) 210 ms. received: testo ricevuto il saline brazilian current and the cold and fresher malvinas current. however, other trace elements (including u) indicate that subtle diagenesis can have occurred for some specimens. in particular u concentration shows values higher in older samples (up to 4 ppm) above the values measured on modern specimens. these data suggest that not all the trace elements can be used as palaenvironmental tools and specifically u seems to indicate which samples cannot be selected for u/th. thin sections of the shells analysed (fig. 2) show that p. antiqua is composed by two well distinct layers, with the outer layer showing the major degree of alteration. several samples of p. antiqua were then prepared for u/th dating in a new manner: the inner and the outer surfaces of the shell are abraded and kept only the core of the inner layer. the comparison between our u/th from already dated outcrops obtained with others methods (schellmann & radtke, 2000 and refs therein) shows that this approach is particularly promising. the data discussed stress the fact that the definition of the concept of alteration is related to the proxy we intend to analyse, and for dating (independently of the methods) careful selection of samples is vital. references brand u. & veizer j. (1980) chemical diagenesis of a multicomponent carbonate system 1: trace elements. j. sediment. petrol., 50(4), 1219–1236. january 14, 2011 14 gennaio 2011 dodd j.r. (1965) environmental control of strontium and magnesium in mytilus. geochim. cosmochim. acta, 29 (5), 385–398. drever j. i. (1997) the geochemistry of natural waters, surface and groundwater environments. prentice-hall. hellstrom j.c. (2003) rapid and accurate u/th dating using parallel ion counting multi-collector icpms. j. anal. at. spectrom.,18, 135-136. kaufman a., broecker w.s., ku t.l. & thurber d.l. (1971) the status of u-series methods of mollusc dating. geochim. cosmochim. acta, 35, 1115-1183. kaufman a., ghaleb b., wehmiller j.f. & hillairemarcel c. (1996) uranium concentration and isotope rat io prof i les within mercenaria shel ls: geochronological implications. geoch. cosmoch. acta, 60, 3735-3746. klein r. t., lohmann k. c. & thayer c. w. (1996) bivalve skeletons record sea-surface temperature and δ 18o via mg/ca and 18o/16o ratios. geology, 24(5), 415–418. mook w.g, (1971) paleotemperatures and chlorinities from stable carbon and oxygen isotopes in shell carbonate. palaeogeogr., palaeoclim., palaeoecol., 9, 245–263. land l. s. (1967) diagenesis of skeletal carbonates. j. sediment. petrol., 37(3), 914–930. schellmann, g. & radtke, u. (2000) esr dating of stratigraphically well-constrained marine terraces along then patagonian atlantic coast (argentina). quaternary international, 68-71, 261–273. takesue r.k. & van geen a. (2004) mg/ca, sr/ca, and stable isotopes in modern and holocene protothaca staminea shells from a northern california coastal upwelling region. geochim. cosmochim. acta, 68 (19), 3845–3861. i. consoloni et al. << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /none /binding /left /calgrayprofile (dot gain 20%) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /error /compatibilitylevel 1.4 /compressobjects /tags /compresspages true /convertimagestoindexed true /passthroughjpegimages true /createjobticket false /defaultrenderingintent /default /detectblends true /detectcurves 0.0000 /colorconversionstrategy /cmyk /dothumbnails false /embedallfonts true /embedopentype false /parseiccprofilesincomments true /embedjoboptions true /dscreportinglevel 0 /emitdscwarnings false /endpage -1 /imagememory 1048576 /lockdistillerparams false /maxsubsetpct 100 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/hrv (za stvaranje adobe pdf dokumenata najpogodnijih za visokokvalitetni ispis prije tiskanja koristite ove postavke. stvoreni pdf dokumenti mogu se otvoriti acrobat i adobe reader 5.0 i kasnijim verzijama.) /hun 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<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> /enu (use these settings to create adobe pdf documents best suited for high-quality prepress printing. created pdf documents can be opened with acrobat and adobe reader 5.0 and later.) >> /namespace [ (adobe) (common) (1.0) ] /othernamespaces [ << /asreaderspreads false /cropimagestoframes true /errorcontrol /warnandcontinue /flattenerignorespreadoverrides false /includeguidesgrids false /includenonprinting false /includeslug false /namespace [ (adobe) (indesign) (4.0) ] /omitplacedbitmaps false /omitplacedeps false /omitplacedpdf false /simulateoverprint /legacy >> << /addbleedmarks false /addcolorbars false /addcropmarks false /addpageinfo false /addregmarks false /convertcolors /converttocmyk /destinationprofilename () /destinationprofileselector /documentcmyk /downsample16bitimages true /flattenerpreset << /presetselector /mediumresolution >> /formelements false /generatestructure false /includebookmarks false /includehyperlinks false /includeinteractive false /includelayers false /includeprofiles false /multimediahandling /useobjectsettings /namespace [ (adobe) (creativesuite) (2.0) ] /pdfxoutputintentprofileselector /documentcmyk /preserveediting true /untaggedcmykhandling /leaveuntagged /untaggedrgbhandling /usedocumentprofile /usedocumentbleed false >> ] >> setdistillerparams << /hwresolution [2400 2400] /pagesize [612.000 792.000] >> setpagedevice available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 37 (2), 2024, 127-141 1. introduction anthropomorphic stelae, characterized by the depiction of human-like figures, are a remarkable testament to the cultural and artistic expressions of ancient societies. created primarily during the iron age and earlier, these monumental stelae are found primarily throughout europe. they offer invaluable insights into the beliefs, rituals, and social structures of past cultures. despite their importance, while there has been considerable research on these stelae (gutherz et al., 1998; koukouli-chrysanthaki, 2007; vierzig, 2017), there remain gaps in understanding their regional variation and symbolic complexity. the caucasus region, with its rich cultural heritage and diverse archaeological landscape, has long fascinated researchers exploring the manifestations of ancient civilizations. among the most intriguing archaeological finds in the caucasus are anthropomorphic stelae, which serve as tangible links to the beliefs and practices of iron age societies in the region. adorned with human-like features, these monumental stone stelae stand as iconic symbols of cultural expression and religious significance (ivanov, 2016; kharitonov, 2017); petrov, 2018; smith, 2019). despite their prominence, scholarly research on anthropomorphic stelae in the caucasus has been relatively sparse, leaving much of their meaning and context shrouded in mystery. however, a handful of studies have emerged that offer valuable insights into the typology, distribution, and cultural implications of these enigmatic monuments. this region boasts a rich archaeological heritage that spans millennia. among its most fascinating relics are the iron age anthropomorphic stelae, which serve as poignant reminders of the cultural, religious, and artistic practices of ancient societies. these imposing stone monuments, adorned with human-like features, stand as enduring symbols of the region's cultural identity and spiritual beliefs (yeranyan, 2021a, 2021b). despite their importance, scholarly attention to iron age anthropomorphic stelae for this region has been relatively limited, with only a handful of studies exploring their complexities and cultural implications. recent archaeological efforts, however, have begun to shed light on these enigmatic structures, providing new insights into their typology, distribution, and socio-cultural significance within the armenian landscape. in 2016, a significant discovery was made by a local resident near the village of nor karmiravan in the https://doi.org/10.26382/amq.2024.07 reviewing the anthropomorphic stelae: people in iron age monument from south caucasus nzhdeh yeranyan 1 , noushig zarikian 1,2 , hasmik simonyan 1 1 institute of archaeology and ethnography, national academy of sciences, yerevan, republic of armenia. 2 scientific center of zoology and hydroecology, national academy of sciences, yerevan, republic of armenia. corresponding author: n. zarikian <nzarikian@gmail.com> abstract: anthropomorphic stelae and related archaeological findings represent some of the most significant advances discovered during the archaeological excavation of the iron age monument in the south caucasus (in nagorno karabakh), particularly in the village of nor karmiravan (papravend)1. during the excavations conducted in 2016-2018 near the anthropomorphic stelae in the area of the village of nor karmiravan, martakert (aghdara) region, our team documented a wide range of archaeological, anthropogenic, and archeozoological materials. among these finds were rectangular, flat, longitudinal slabs that describe anthropomorphs through their dimensional and sculptural processing, in addition to the stelae themselves. this paper attempts to present the results of the excavations at the nor karmiravan monument and to analyze the social attitudes and motivations of the iron age people of the south caucasus toward these stone monuments. keywords: archaeozoology; anthropology; iron age; anthropomorphic stelae. 1 the study focuses on a monument located in nagorno-karabakh, a region marked by conflict between armenia and azerbaijan. following the trilateral ceasefire agreement of november 9, 2020, these territories came under azerbaijani control. the article presents the names of the settlements in both the armenian and azerbaijani forms at the time of first mention, while retaining the original names as documented during the research period. 128 yeranyan et al. martakert region. about a dozen anthropomorphic stelae or fragments of them were accidentally uncovered. the concentration of these stelae in one area, together with certain features of the surrounding landscape, suggested that this site might be the original site of their creation and use (fig. 1). to determine this, excavations were conducted in the vicinity of the stelae and the nearby dug water channel. from 2016 to 2018, the artsakh archaeological expedition conducted these excavations under the auspices of the institute of archaeology and ethnography of the national academy of sciences of the republic of armenia. the purpose of this study is to comprehensively examine the stelae of nor karmiravan, to evaluate their archaeological context through excavation, and to determine whether they are in situ or have been relocated. by studying these stelae, valuable insights can be gained into their date of origin, purpose, and connection to iron age communities in the region. 2. materials and methods 2.1. anthropomorphic stelae of artsakh the stelae under discussion are flat, elongated slabs that represent anthropomorphic features through their sculptural and dimensional characteristics. these slabs are divided into three sections by two horizontal chamfers that delineate the head, torso, and lower part of the body (fig. 2). the observed stelae were found scattered over a longitudinal region that includes both highland and steppe terrain and extends for approximately 30-40 kilometers. they are mainly located in the northeastern areas of artsakh (karabakh), near martakert, tigranakert, and the adjacent settlement of gyavurkala (yeranyan, 2021a). during the soviet era, several stelae from this area were transferred to the historical and geological museums of stepanakert and martakert for preservation, while some remained in their original outdoor locations. 2.2. methods the study of this topic has been conducted through a synthesis of interdisciplinary methodologies. first, archaeological excavations were used to collect data. subsequently, the artifacts unearthed were subjected to iconographic analysis using the historical-comparative method. ams 14c dating was then used to establish the chronological framework of the tomb through laboratory analysis of samples taken from the archaeological materials. the human remains were analyzed in the laboratory of the state non-commercial organization "service for protection of historical environment and museum reserves" (republic of armenia). after cleaning and reconstruction of skeletal elements, the state of preservation (connell, 2008) and representation (buikstra & ubelaker, 1994) were documented. subsequently, ageat-death estimation, sex determination (ubelaker, 1979; buikstra & ubelaker, 1994; mays, 1998; white & folkens, 2005), and skeletal stature estimation (pearson, 1899; trotter & gleser, 1962) were perfig. 3 general view of the excavations carried out around the water canal. fig. 1 the concentration of stelae in one area: the view before excavations. fig. 2 anthropomorphic stela, bakhshun-tapa. 129 iron age anthropomorphic stelae formed. the presence of pathologies, skeletal anomalies, and non-metric traits were noted (aufderheide & rodriguez-martin, 1998; ortner, 2003; mann & hunt, 2005; waldron, 2009; spiros, 2019). in addition, skeletal features identified in the literature as functional adaptations or stress markers have been documented (robb, 1998). in addition, archaeozoological materials are examined at the archaeozoological laboratory of the institute of archaeology and ethnography of the national academy of sciences of the republic of armenia. 2.3. nor karmiravan site (nks) the village of nor karmiravan is located in the martakert region, nestled in the lower valley of khachenaget. in 2016, the first anthropomorphic stelae were unearthed in the village. further exploration revealed the presence of about a dozen complete or fragmented anthropomorphic stelae. the majority of fig. 5 the jar was found at the bottom of the water canal. fig. 4 aerial photograph of the tomb (photo by a. mkrtchayn). fig. 7 different single-handled large jugs. fig. 6 the single-handled small jugs. 130 yeranyan et al. came clear that the burial pit was located approximately in the center of the cromlech. the underground chamber had a rectangular shape with a 30-degree deviation in an east-west direction. it was 6.4 meters long and 1.6 meters wide. notably, the burial chamber had a distinct slope along its longitudinal axis (fig. 5). in the northeastern part of the burial chamber, the fragmented skull of the deceased was unearthed at a depth of 70 centimeters. the entire layer was densely filled with animal bones, while mollusk shells were documented in a layer approximately 30 centimeters deep. in addition, in the western part of the burial chamber, a horse burial was uncovered, accompanied by fragments of a bridle and decorative elements. it is noteworthy that burials with a similar structural layout are not uncommon in this region. the kurgans with single burials are a characteristic feature of the ivanyan (khojaly) cemetery and form a separate subgroup (kushnareva, 1970). 3. results and discussion 3.1. findings the burial artifacts discovered in the nks tomb can be divided into several groups, including beads, weapons, a horse bridle, horse grooming accessories, and pottery. a total of 41 jars belonging to the same historical period were unearthed. the pottery can be further classified as follows: 3.1.1. small single-handled jugs these jugs have a small base, a narrow waist, and a neck that begins at the shoulder and flares upward in a trumpet shape. the handle is attached to the lip with an outward spiral (fig. 6). this type of pottery is particularly characteristic of iranian ceramics, which evolved from earlier iranian styles and reached its final form by the end of the 2nd millennium bc (young, 1965; pogrebova, 1977). similar examples have been found at various iranian sites such as hasanlu v, giyan i, gyoytepe, and khorvin-chandar (pogrebova, 1977). 3.1.2. single-handle large jugs a. these relatively small jugs have a spherical body with a narrow, elongated neck and an outwardly flared lip. the round handle extends from the lip and is attached to the center of the body. some examples have convex horizontal patterns on the body, decorated with polished spruce decorations (fig. 7a). similar jugs have been dated to the 9th century bc in iranian sites (medvedskaya, 1982) and have also been found in armenian stele sites such as sarapat, vanadzor, astghi-blur, voskehask, skhtorashen (kushnareva, 1957) and surrounding khojaly (petrosyan, 1993) martakert (asryan, 1973) etc. b. glasses with a flat bottom, convex from the middle and ending with a short neck. the lip widens outward and the handle, round in section, starts from the lip and is attached to the bulging shoulder of the body. in the convex part, these jugs have horizontal and vertical line patterns made by polishing (fig. 7b). c. small, flat-bottomed jugs with a widening toward the center of the body, a narrow, elongated, trumpetthese stelae were clustered in a single area, with two additional stelae located 100-150 meters northeast of the main group. in addition, two stelae were uncovered in the courtyard of a village residence and one stela was discovered during construction activities. in addition, several fragments were found in the surrounding area. prior to these excavations, about twenty similar anthropomorphic stelae had been documented in this region (khalilov, 2004: 100-104). the stelae discovered in the village of nor karmiravan do not show any distinctive features that would distinguish them from others found within the same series. 2.4. excavations from 2016 to 2018, excavations were conducted at two primary sites: a. at the main collection site of the nks stelae. b. approximately 200 meters northwest of the nks, near a canal built in the second half of the 2000s. 2.4.1. excavation of the water canal site during the first year, excavations were conducted simultaneously at both sites. while exploring the area around the stelae, a single jar was discovered at the bottom of the water canal (fig. 3). this jar appeared to be unfinished, with a portion of the bulging belly broken. beneath the broken area, two carved zones filled with diamond-shaped patterns adorn the bulging section, while carved, dotted triangular and circular patterns are found at the four corners below the broken area. excavations confirmed an underground burial at a depth of 1.1 meters at this site. anthropological remains consisted of a skull and various skeletal fragments, along with the discovery of 18 jars of different shapes, as well as beads made of paste, sardion and bronze were discovered. however, the archaeological material was incomplete and the integrity of the skeleton was violated; some bones were found under the skull, while others were scattered around the sides of the jars (fig. 4). it is believed that the position of the skeleton was disturbed by the construction of the canal. the excavation also yielded a significant quantity of shells and beads made of iron, paste, and sardion. in addition, four single-handled jars, one unhandled jar, three jugs and a butter churn were found. the material found is typical of the materials with a black shiny torso found in this region and other stelae in the region, some of which can be dated to the 9th-8th centuries bc, and others to the 7th-6th centuries bc. it should also be noted that while the excavations confirmed only one burial, pottery found by chance in other areas during the construction of the canal in previous years by the artsakh archaeological expedition was also authenticated. (petrosyan et al., 2008). 2.4.2. tomb excavations the next and most important excavation site was the area around the stelae collection, where a grave was excavated. during the excavations in 2018, a cromlech armor with a circular ground plan and a diameter of 11 meters was uncovered. after removing the upper layer of soil, which was about 50-70 centimeters thick, it be 131 iron age anthropomorphic stelae 132 yeranyan et al. shaped neck, and an outwardly curving lip. the flat, cut handle begins at the lip and is attached to the lower part of the neck of the body (fig. 7c). 3.1.3. double-handled and handleless jugs one example of each type was recorded. the double-handled jug has vertical, rounded rims attached to the convex body (fig. 8). carved bands decorate the central part of the neck and the broad part of the body. similar jars have been found at redkin lager and are dated to the 8th century bc. the discovered no-handle jug has a black dull surface, with a widening in the middle of the body, a small seat, and an indented bottom with a black matte surface (fig. 9) with a hole in the neck. vertical polished ornaments are present in the central part of the body. 3.1.4. jugs found in the tomb. the pottery found in the tomb can be divided into three groups: single-handled, double-handled, and unhandled (fig. 10 a, b, c). these ceramics are similar to earlier types dating to the 3rd to 2nd millennia bc. in the north caucasus (kushnareva et al., 1994) and have also been found at sites such as shirakavan, keti, and angeghakot dating to the 8th to 7th centuries bc. (khnkikyan, 1993). the 8th to 7th century bc pot type was the most reasonable date for the pottery found in the nks. two particularly noteworthy discoveries from the tomb are the two rhytons. these are similar to the traditional rhytons characterized by their trumpet-shaped necks connected to animal-shaped torsos. however, they differ from typical examples by their elbow-shaped connection systems that widen to the floor (fig. 11). one rhyton (the smaller one) is decorated with radial mat patterns, while the torso of the other is connected to the ground by three buckled belts. similar silver rhytons have been found in iranian monuments of the achaemenid period (bashash, 1997). butter churn: a gray, elongated design and wide, flat-bottomed churn was discovered (fig. 12). it has a nail curve and a horizontal handle near the spout. such jars have a wide spatial and temporal distribution and are commonly found in monuments dating to the first quarter of the 2nd to 1st millennium bc, with no specific dating characteristics (summers & burney, 2012). brick-colored bowl: the only three-legged bowl unearthed (fig. 13) has a short, vertical handle extending from the lip and is rounded in section. similar bowls have been unearthed in other monuments throughout the territory of artsakh, such as chaylu and the iron age tombs of shushi (asryan, 1973). under the northeastern wall of the tomb, the excavation team uncovered a jar with a spherical body and lip opening outward. the jar contained archaeobotanical material to a depth of 50 centimeters. similar pitchers have been documented in numerous late bronze age monuments in the region (torosyan et al., 2002). in addition to the aforementioned pottery found in various parts of the burial chamber, including under the skull, a small number of broken jar fragments were also discovered. some researchers suggest that breaking and burying objects in a tomb symbolizes a ritual death, fig. 8 double-handle jugs. fig. 9 no-handle jugs fig. 10 (a) no-handle jug; (b) single-handle jug; (c) doublehandle jug. possibly related to beliefs in the reincarnation of the deceased (kuftin, 1941; tumanyan, 2010). the metal artifacts recovered from the tomb are relatively scarce, consisting of bronze pendants, scythian-type bronze arrowheads (fig. 14), several bronze beads, and part of an iron bridle. the arrowheads found are typical of those found in the south caucasus, known in the literature as "scythian type" arrowheads (archaeology of the ussr, 1992: 37, 40, 49, 92, 292294, 369), dating back to the 8th century bc. however, this type of arrow was used even later (dyachenko et al., 2000; genz, 2011). iessen dates this type of threepronged arrow in south caucasian graves to the 7th-6th centuries bc (iessen, 1965). the iron bridle found near the horse burial showed signs of considerable wear. among the materials accompanying the horse burial were several parts of a bone bridle with a horse's head at the top, a horse's hoofshaped end at the bottom, and three hollow holes in the middle. similar sculptures have been found in monuments in the black sea region and eastern europe dating to the 7th-6th centuries bc (kantorovich, 2016). a pear-shaped granite mace with a hollow hole was found on the tomb floor (fig. 15), probably made during the earlier iron age and commonly found in monuments from the 15th-13th centuries bc (muhle, 2008; piller, 2013). the prolonged use of such middle bronze age weapons has been observed in the region, dating back to the xiv-viii centuries bc (torosyan et al., 2002). a fascinating discovery in the eastern corner of the tomb was the abundance of beads made of paste, sardion and bone. nearly 5,000 beads of various types were found, presumably arranged on a cloth as part of the burial ritual. the tomb also contained a large number of mollusc shells, over 300 of which covered the entire floor. 3.2. human remains from the burial of nks the cranial segment is present but fragmented and incomplete, with missing parts including portions of the temporals, facial bones on both sides, the left ramus of the mandible, and the left mandibular condyle. skull reconstruction was achieved for a proportion of 80%. the occipital bone was deformed postmortem. the postcranial skeleton is nearly complete but fragmented postmortem, with missing parts including spine bones, some ribs, midshaft of the left ulna, midshaft and upper epiphysis of the right humerus, right scapula, left hip bones, left femur and tibia, upper epiphysis of the right tibia, feet, and hand bones. only the upper epiphysis of the right femur is presented (fig. 16). 3.2.1. age-at-death estimation and sex determination the age-at-death assessment was based on pubic symphysis morphology scored according to various systems such as todd (1920) and brooks & suchey (1990), as well as auricular surface assessment according to meindl & lovejoy (1989). additionally, cranial vault suture closure was scored on a 4-point scale following meindl & lovejoy (1985). the individual was estimated to be between 30 to 40 years old. sex determination was made based on pelvic and cranial traits, indicating a male. 133 iron age anthropomorphic stelae fig. 12 butter churn. fig. 11 rhytons. 134 yeranyan et al. 3.2.2. dental pathologies moderate physiological dental wear (attrition), one incipient cavity (likely new dental caries development) on the left lower first molar (fig. 17a), supragingival calculus on upper and lower molars and premolars on the lingual and buccal sides were observed (fig. 17b, c). the plaque deposition suggests a diet rich in hard fibrous foods of vegetable origin, high in carbohydrates (lukacs, 1989). 3.2.3. cranial non-metric features the two frontal bones are seen due to the complete metopic suture, extending from the bregma to the nasion (fig. 18). the metopic suture, present in a newborn and typically obliterated by around 7 years of age, occasionally persists as an anatomical variant with little clinical significance (gardner, 2016). metopism incidence ranges from 0% to 7% associated with ethnicity (berry & berry, 1967), with males showing a higher prevalence (murlimanju et al., 2011). persistent metopic suture occurs in conjunction with refining the ability to walk and is suggested to aid in the birthing process for infants with larger brains and is associated with postnatal brain growth and frontal lobe expansion (falk et al., 2012). 3.2.4. postcranial non-metric features a perforation of the coronoid-olecranon septum (septal aperture) in the right humerus has been identified (fig. 19a). recent studies indicate that this perforation is a response to hyperflexion rather than hyperextension of the elbow. the apertures form primarily through resorption of the humeral septum at a point where the coronoid process of the ulna would potentially make contact in full flexion (mays, 2008). 3.2.5. the metabolic disorder the metabolic disorder occurs in the case of the individual, in the form of porotic hyperostosis (cribra orbitalia/co), inactive at the moment of death. both orbits are affected by co; however, due to incomplete orbits, the extent of co could not be accurately determined (fig. 20). nonetheless, the presence of porotic hyperostosis suggests poor living conditions, potential chronic health issues, and dietary deficiencies, particularly iron deficiency (walker et al., 2009). 3.2.6. postcranial pathologies postcranial pathologies were also observed, including intervertebral disc herniation (schmorl’s nodes) on the thoracic vertebral body (fig. 21). schmorl’s nodes are depressions on the upper and lower surfaces of the vertebral body resulting from vertical intervertebral disc herniation, indicative of spine overloading, frequent weight lifting, maintaining a vertical posture with a burden on the back, repetitive spine bending, etc. (palfi & dutour, 1996). additionally, a probable stress-related injury at the medial epicondylar apophysis was detected on the left humerus (fig. 19b). such injuries typically occur during adolescence, throwing activities are performed near the end of skeletal maturation, when the medial epicondyle is not yet fully fused (12-18 years of age), leading to bony detachments in the area of the medial collateral ligament fig. 13 the brick-colored bowl. fig. 14 scythian-type bronze arrowheads. fig. 15 pear-shaped mace. 135 iron age anthropomorphic stelae fig. 16 skeleton in standard anatomical position fig. 17 (a) new dental caries development; (b, c) dental calculus on upper and lower molars and premolars. 136 yeranyan et al. insertion. these detachments can be complete in individuals younger than 15 years old and partial in older teens, resulting in the avulsion of one or more bony fragments from the medial epicondylar apophysis (kijowski & tuite, 2010). upon reaching adulthood, healed lesions from such fractures manifest as bony outgrowths or lacunae, depending on whether the avulsed fragment re-united with the condyle (lewis, 2017). in archaeological remains, these lesions are commonly observed as scars from traumatic events during adolescence, particularly on adult humeri (villotte et al., 2010). given the traumatic and pathological markers evident on the skeleton, it can be inferred that the individual from the nks tomb experienced various physiological stressors during their lifetime, including spine overloading, potentially frequent weight lifting, and a humeral trauma resulting from adolescent throwing activities. 3.3. animal remains the animal remains found at the site predominantly consist of mammal bones. a total of 1319 bone particles were examined, with 661 bones successfully identified and 658 remaining unidentified. the majority of identified bones belong to domesticated ungulates, including 6 sheep/goats, 2 cattle (bos taurus), 1 bos primigenius, and 4 horses (equus caballus). among wild animals, one roe deer was identified, along with one member of the felidae family (cat/fox) (hillson, 2009; prehn et al., 2018) (tab. 1 and fig. 22). 3.3.1. bone modifications: cut and butchering marks: some bones exhibited marks indicating butchering and cutting into smaller parts, with approximately 5% of remains showing such marks. this suggests that animal sacrifice was not a widespread practice solely for obtaining meat or food. chewing, gnawing, and digestion by animals: damage caused by birds and carnivores, as well as traces of digestion (e.g., hydrochloric acid from predator stomachs), were observed on some bones. pathology: several pathological features were noted on animal bones. this proves the site occupiers’ cutlers and livestock breeding quality during the given fig. 18 metopic suture (the suture on the frontal bone). fig. 20 cribra orbitalia (the porous areas in the top of the eye sockets). fig. 19 (a) septal aperture in the right humerus; (b) injury at the medial epicondylar apophysis on the left humerus. fig. 21 schmorl’s node on the thoracic vertebral body. age. the recorded anomalous case was the sacral slope and sacral curvature in one individual of sheep/goats (fig. 23a). burning of refuse: no burnt bones were recorded, suggesting that cooking methods for some of the buried animals involved boiling rather than direct grilling over a fire. weathering: some mammal bones at the site displayed weathering characteristics. tools and artifacts: a few bone-made items, including horse harness fittings, antler fittings, beads, and a perforated pendant made from an incisor, were discovered (fig. 23b). 3.3.2. animals' mortality age using i. silver's methods, it was estimated that the majority (84.62%) of the animals were adults, with a smaller proportion (15.38%) being 1-2 years old (don et al., 1969) (tab. 2). 3.4. problems of dating of anthropomorphic stelae as noted above, none of the three dozen or so stelae found in the steppes of artsakh had been authenticated at their original sites of discovery. through various excavations and research efforts, we have only been able to confirm the oldest date associated with these stelae (yeranyan, 2021b). by conducting a comparative analysis of these stelae with similar ones found in the region, we have tentatively dated the anthropomorphic stelae of artsakh to the early 1st millennium, specifically between the 8th and 6th centuries bc, although further validation is required. consequently, the excavation and discovery of these stelae in their original positions has made the issue of dating them an urgent priority. a critical factor in dating the tombs was the analysis of the archaeological finds. it is noteworthy that many of the pottery sherds were similar to those found in armenian, azerbaijani, and iranian monuments, suggesting a wide spatial and temporal distribution for their possible dating. upon examination, it became clear that the stone anthropomorphic stelae from artsakh share similarities with those found in the north caucasus, the black sea region, the crimea (olkhovskii & yevdokimov, 1994), as well as meshkin shahr (ingraham & summers, 1979; burney, 1979; azarnoush & helwing, 2005; piller, 2010), and the well-known stelae from hakkâri (sevin, 2005), which, according to various researchers, date from the beginning to the end of the 2nd millennium bc to the 4th-3rd century bc. regarding the dating of the nks tomb, the pottery designs and decorations, with some exceptions, correspond to the pottery of the widely distributed stelae of the region. the discovered pottery dates back to the 8th 7th and 7th 6th centuries bc. further precision in dating was achieved through laboratory c14 analysis of a sample from the burial. research conducted at the vilnius radiocarbon laboratory indicates that the burial dates to approximately 2486 bp, with a margin of error of ±30 years (fig. 24). it can be concluded that the tradition of erecting anthropomorphic stelae in artsakh probably began in the 8th or 7th century bc and continued until the first half of the 5th century bc. 3.5. the possible function of anthropomorphic stelae excavations at the nks tomb, as well as a broader survey of its surroundings, suggest a possible relationship between the stelae and the tomb. it is worth noting that the study of the stone anthropomorphic stelae of artsakh would have been impossible without comparative material and parallels from the south caucasus, iran, the north caucasus, and the near black sea region (olkhovsky & yevdokimov, 1994). consequently, these stelae could be placed in a broader east asian cultural context, while considering the temporal aspect 137 iron age anthropomorphic stelae tab. 2 the animal mortality ages. tab. 1 number of identified species (nisp) and minimum number of individuals (mni) of animals' osteological remains. fig. 22 identified species percentage in the site. alongside other contemporary stelae found in armenia. archaeological excavations have revealed various scenarios suggesting that monuments were occasionally erected on burial mounds in armenia during the late bronze and early iron ages (tumanyan, 2003). some archaeologists suggest that the anthropomorphic tuff monument over 1.5 meters high discovered at metsamor may have served as a funerary monument (khanzadyan et al., 1973). the nks stelae were found lying down and may have shifted slightly over time, especially during the soviet era when irrigation pipes were installed in the area, altering the landscape. these stelae were discovered within the cromlech of the tomb, suggesting their association with the tomb. however, determining the nature of their relationship, their specific placement within the tomb, and their intended purpose remains challenging at this stage. infrared filtered images of the area surrounding the excavated nks tomb revealed the presence of other tombs nearby. in essence, this area appears to have been a substantial burial ground where the burials were highly regarded and the anthropomorphic stelae in question were erected on site. 4. conclusions research on the nks stelae provides additional insights that complement our understanding of the artsakh stelae. to summarize: the stelae in question, although fallen and probably slightly displaced, were discovered directly on top of the tomb. even if they were moved and reassembled later, their archaeological context is known; they were associated with about a dozen tombs in the area. this significant detail adds to our knowledge of anthropomorphic stelae in the south caucasus. the materials unearthed during the excavations have parallels both in artsakh and in other archaeological complexes in the region dating back to the first half of the 1st millennium bc. the tomb, with its distinctive structure and accompanying rich materials, along with similar findings, dates back to the 8th-6th centuries bc. examination of the nks stelae suggests that it's likely that they were made and erected on site. two factors lend support to this hypothesis. first, some of the stelae show unfinished details that allow us to infer the carving process and the tools that were probably used. second, there are large fragments of limestone in the vicinity, which were probably brought to the site for the production of the stelae. fragments of limestone found within the row of cromlech armor and lying on the surface, created by breaking and separating from larger fragments, further support this notion. it is likely that they were also prepared in situ for the creation of stelae. at this stage of research, with only one tomb excavated, it's difficult to determine their exact relationship to 138 yeranyan et al. fig. 23 animals bone modifications (a) pathology traces on bone; (b) bone-tools. fig. 24 the results of the c14 analysis of human remains. the tomb, including their location and position. however, given the cultural context of the area, the clustering of stelae, and the examination of parallel materials from the region, it's clear that the stelae were originally associated with these tombs. moreover, as m. pogrebova noted, the south caucasian single-handled jugs, despite their similarities, retain their uniqueness. in particular, the upper part of the handle of iranian jugs is connected to the body in the middle, while in south caucasian examples it's often connected near the lip, indicating in-situ production of jugs of this type (pogrebova, 1977). these jars fell out of use in iran at the beginning of the first millennium, suggesting a chronology no later than that. meanwhile, the south caucasian examples, according to a. iessen, are dated to the 8th-7th centuries bc., a timeline that also applies to those found in the nks (iessen, 1965). author contributions conceptualization n.y.; methodology n.y., h.s.; writing n.y., n.z.; review and editing, n.z., h.s.; all authors have read and agreed to the published version of the manuscript. acknowledgements we thank lilit minasyan for illustrations, tatiana vardanesova for materials restoration, arshaluys mkrtchyan and vram hakobyan for photography. references archaeology of the ussr (1992) steppe strip of the asian part of the ussr in scythian-sarmatian times, vol. 10. (in russian). asryan y. (1973) archaeological novelties in karabakh. historical-philological journal, 2, 295300. (in armenian). aufderheide a.c., rodriguez-martin c. (1998) the cambridge encyclopedia of human paleopathology, cambridge university press, cambridge. azarnoush m., helwing, b. (2005) recent archaeological research in iran: prehistory to iron age. amit, 37, 189-246. bashash r. (1997) four features of the inscriptions on objects of kalamkare cave. shush complete collection of archaeological materials, 13-22. berry c.a., berry r.j. (1967) epigenetic variation in the human cranium. journal of anatomy, 101, 361 -379. brooks s., suchey j.m. (1990) skeletal age determination based on the os pubis: a comparison of the acsádi-nemeskéri and suchey-brook’s methods. human evolution, 5(3), 227-238. buikstra j., ubelaker d. (1994) standards for data collection from human skeletal remains. arkansas archaeological survey research series 44. fayetteville. burney c. (1979) meshkinshahr survey. iran, xvii, 155 -156. connell b. (2008) preservation and archaeological data. in: human osteology method statement (ed. by powers n.), museum of london. don r., brothwell e., higgs s., grahame c. (1969) science in archaeology: a survey of progress and research. chapter 6. the ageing of domestic animals. thames and hudson, london, 283-302. dyachenko a., skripkin a., klepikov v., kubyshkin a., mabe a. (2000) excavations of the aksai kurgans in the volga-don region. in: kurgans, ritual sites, and settlements eurasian bronze and iron age (ed. by davis-kimball j. et al.). bar international series. oxford, 43-62. falk d., zollikoferc c.p.e, morimotoc n., de leónc m.s.p. (2012) metopic suture of taung (australopithecus africanus) and its implications for hominin brain evolution. proceedings of the national academy of sciences, 109, 8467-8470. gardner s. (2016) a persistent metopic suture: a case report. austin journal of anatomy, 3(1), 1049. genz h. (2011) the iron age in central anatolia. in: the black sea, greece, anatolia and europe in the first millennium bc (ed. by tsetskhladzem g.). leuven paris walpole. 331-368. gutherz x., jallot l., garnier n. (1998) exploring the iconography of anthropomorphic stelae in the european context. european journal of archaeology, 5(1), 45-67. hillson s. (2009) mammal bones and teeth: an introductory guide to methods of identification (ucl institute of archaeology publications (lcp)), university college london institute of archaeology, p. 64. iessen a. (1965) from the historical past of the milkarabakh steppe. proceedings of the azerbaijan archaeological expedition, 2, 24-30. (in russian). ingraham m., summers g. (1979) stelae and settlements in the meshkin shahr plain, northeastern azerbaijan, iran. amit, 12, 67-87. ivanov m. (2016) the symbolism and ritual function of caucasus anthropomorphic stelae. journal of caucasian archaeology, 8(1), 55-72. khalilov m. (2004) anthropomorphic steale of karabakh, "azerbaijani archaeology", 1-4, 100104. (in russian). kantorovich a. (2016) the image of a horse in the eastern european scythian animal style, the caucasus and the steppe at the turn of the late bronze age and early iron age. in: proceedings of the international scientific conference dedicated to the memory of maria nikolaevna pogrebova, 89114. (in russian). khanzadyan e., mkrtchayn k., parsamyan e. (1973) metsamor. yerevan. (in armenian). kharitonov d. (2017) between east and west: the role of anthropomorphic stelae in caucasus interactions. eurasian archaeology quarterly, 12(4), 211-228. khnkikyan o. (1993) tomb excavations in tsaghkashat village of tumanyan region. archaeological works in new buildings of armenia, i, 86-89. (in armenian). kijowski r., tuite m.j. (2010) pediatric throwing injuries of the elbow. seminars in musculoskeletal radiology, 14(4), 419-429. koukouli-chrysanthaki c. (2007) cultural significance 139 iron age anthropomorphic stelae and regional variations in european anthropomorphic stelae of the iron age. archaeological review from cambridge, 22(2), 87-102. kuftin b. (1941) archaeological excavations in trialeti, vol. 1. tbilisi. (in russian). kushnareva k. (1957) some monuments of the late bronze age in nagorno-karabakh. soviet archaeology, xxvii, 135-177. (in russian). kushnareva k. (1970) khojaly burial ground. historical and philological journal, 3, 109-124. (in russian). kushnareva k., markovin v., djafaradze o., mikhaylovich m. (1994) bronze age of the caucasus and central asia. moscow. (in russian). lewis m. (2017) paleopathology of children: identification of pathological conditions in the human skeletal remains of non-adults. academic press, london. lukacs j.r. (1989) dental palaeopathology. methods for reconstructing dietary patterns, in: iscan, m.y., kennedy, k.a.r. (eds), reconstruction of life from the skeleton, wiley-liss publisher, new york, 261 -286. mann r.w., hunt d.r. (2005) photographic regional atlas of bone disease: a guide to pathologic and normal variation in the human skeleton. springfield: charles c. thomas publisher. mays s. (1998) the archaeology of human bones. routledge, london. mays s. (2008) septal apertura of the humerus in a medieval human skeletal population. american journal of physical anthropology, 136, 432-440. medvedskaya i. (1982) iran: iron age i. bar international series. oxford. meindl r.s., lovejoy c.o. (1985) ectocranial suture closure: a revised method for the determination of skeletal age at death based on the lateral-anterior sutures. american journal of physical anthropology, 68(1), 57-66. meindl r.s., lovejoy c.o. (1989) age changes in the pelvis: implication for paleodemography. in: age markers in the human skeleton (ed. by işcan m.y.). charles c. thomas, springfield. 137-168. muhle b. (2008) vorderasiatische keulen und ihr umfeld vom 9. bis ins frühe 1. jt. v. chr. typologie und deutung. phd thesis dissertation. ludwigmaximilians-universität, münchen. (in german). murlimanju b.v., prabhu l.v., pai m.m., goveas a.a., dhananjaya k.v., somesh m.s. (2011) median frontal sutures-incidence, morphology and their surgical, radiological importance. turkish neurosurgery, 21, 489-493. olkhovskiy v., yevdokimov g. (1994) scythian sculptures of the 7th-3rd centuries bc. moscow. ortner d.j. (2003) identification of pathological conditions in human skeletal remains. academic press, oxford. pálfi g., dutour o. (1996) activity-induced skeletal markers in historical anthropological material. international journal of anthropology, 11(1), 41-55. pearson k. (1899) mathematic contributions to the theory of evolution. v. on the reconstruction of the stature of prehistoric races. philosophical transactions of the royal society, ser. a, 192, 169-244. petrosyan l. (1993) excavations in sarapat, archaeological works in new buildings of armenia, i, yerevan, 90-96. (in armenian). petrosyan h., khachatryan zh., piliposyan a., hakobyan a., safaryan v., kirakosyan l. (2008) the first results of the archeological research of tigranakert in artsakh and its surroundings in artsakh. the culture of ancient armenia xiv, 187. petrov s. (2018) exploring the cultural landscape: anthropomorphic stelae in the caucasus highlands. caucasian studies journal, 4(3), 127-145. piller c.k. (2010) northern iran in the iron age ii and iii: a neighbor of urartu?, “aramazd” ajnes, v/2, yerevan, 53-75. piller c.k. (2013) the caucasian connection reflections on the transition from the late bronze to the early iron age in northern iran and its connections to the southern caucasus. schriften des zentrums für archäologie und kulturgeschichte des schwarzmeerraumes, 22, 305-317 pogrebova m. (1977) iran and south caucasus during early iron age. moscow. (in russian). robb j.e. (1998) the interpretation of skeletal muscle sites: a statistical approach, international journal of osteoarchaeology, 8(5), 363-377. prehn n., feneru f., rochester j. (2018) beginner’s guide to identifying british mammal bones. natural history museum, london. sevin v. (2005) who were the naked warriors of hakkari? amit, 37, 163-166 smith a. (2019) anthropomorphic stelae of the caucasus: a comprehensive survey. caucasus archaeology, 15(2), 89-112. spiros m.c. (2019) standardization of postcranial nonmetric traits and their utility in ancestry analysis. forensic anthropology, 2(1), 29-44. summers g., burney c. (2012) late iron age pottery from northwestern iran: the evidence from yanik tepe. anatolian iron ages, 7, peeters, leuven, paris, 269-315. todd t.w. (1920) age changes in the pubic bone. i. the male white pubis. american journal of physical anthropology, 3(3), 285-334. torosyan r., khnkikyan o., petrosyan l. (2002) old shirakavan, yerevan. (in armenian). trotter m., gleser g. (1962) estimation of stature from long bones of american whites and negroes. american journal of physical anthropology, 10, 469-514. tumanyan g. (2003) the structure of late bronze age tombs in armenia, historical-philological journal, n1, yerevan, 166-185. (in armenian). tumanyan g. (2010) remarks on some issues related to the goods of late bronze age burials of armenia, historical-philological journal, 3, 147-160. (in armenian). ubelaker d.h. (1979) human skeletal remains excavation, analysis and interpretation. taraxacum, washington d. c. vierzig l. (2017) anthropomorphic stelae in european prehistory: a comprehensive study. journal of european archaeology, 20(2), 145-167. villotte s., churchill s.e., dutour o.j., henry-gambier 140 yeranyan et al. d. (2010) subsistence activities and the sexual division of labor in the european upper paleolithic and mesolithic: evidence from upper limb enthesopathies. journal of human evolution, 59(1), 3543. waldron t. (2009) palaeopathology. cambridge university press, cambridge-new york. white t.d., folkens p.a (2005) the human bone manual, academic press, amsterdam-boston. walker p.l., bathurst r.r., richman r., gjerdrum t., andrushko v.a. (2009) the causes of porotic hyperostosis and cribraorbitalia: a reappraisal of the iron-deficiency-anemia hypothesis, american journal of physical anthropology, 139(2), 109125. yeranyan n. (2021a) two stone anthropomorphic stelae from jujevan, middle east. history, politics, culture, viii, yerevan, 73-78 (in armenian). yeranyan n. (2021b) main results of the study of anthropomorphic stelae in artsakh, archaeology of armenia in regional context, yerevan, 248-254. young c. (1965) a comparative ceramic chronology for western iran. 1500-500 bc, “iran”, vol. iii, 8-9. 141 iron age anthropomorphic stelae ms. received: april 3, 2024 revised: may 29, 2024 accepted: november 29, 2024 available online: december 19, 2024 il trasporto solido nei corsi d'acqua minori dell'oltrepo pavese: alcuni caratteri peculiari nel contenuto delle torbide del t. versa gianfranco ciancetti, gabriele dolza & giorgio pilla laboratorio i.c.g. dipartimento di scienze della terra università degli studi di pavia e-mail cttgf@unipv.it riassunto: ciancetti g., dolza g. & pilla g.: il trasporto solido nei corsi d'acqua minori dell'oltrepo pavese: alcuni caratteri peculiari nel contenuto delle torbide del t. versa. (it issn 0394-3356, 2008). gli studi condotti dal laboratorio icg del dipartimento di scienze della terra dell'università di pavia, sulle acque superficiali dell'area pavese hanno portato a riconoscere alcune caratteristiche dei corsi d'acqua che, ad esclusione del t. staffora, sono comuni a tutti gli altri piccoli corsi d'acqua che drenano il territorio collinare e montano dell'oltrepo pavese. sono state prese in considerazione le caratteristiche geolitologiche, le condizioni climatiche, l'estensione e la morfologia dei bacini, l'uso del suolo, nonché l'instabilità dei versanti. il bacino utilizzato come riferimento è quello del t. versa. la valle versa è una delle valli dell'oltrepo pavese in cui la coltura della vite, è divenuta prevalente da quasi un secolo; per effetto delle pratiche agricole e della tipologia dei terreni, prevalentemente argillosi presenti, si è potuto evidenziare un accumulo negli stessi terreni, di taluni metalli pesanti come il rame e lo zinco presenti nei prodotti fitosanitari distribuiti per la lotta antiparassitaria. l'area, dal punto di vista geologico, è distinguibile in due settori che, ovviamente, si riflettono nelle caratteristiche morfologiche del bacino idrografico. il settore centro-settentrionale della valle, costituito da litotipi marnoso-argillosi, con rari conglomerati, arenarie e calcari, caratterizzato da una morfologia collinare ed il settore meridionale in cui affiorano litotipi a forte componente calcarea. la ridotta permeabilità dei terreni affioranti, favorisce il ruscellamento superficiale delle acque meteoriche, piuttosto che l'infiltrazione, creando le condizioni per una erosione accelerata del suolo ed il trasporto di elevate quantità di sedimenti nel reticolo idrografico. la distribuzione delle piogge, tipica dell'oltrepo, presenta un massimo assoluto nel mese di novembre ed un minimo assoluto nel mese di agosto, mentre nei rimanenti mesi dell'anno, le piogge risultano abbastanza omogeneamente distribuite. strettamente correlato agli afflussi meteorici, il deflusso del torrente versa è caratterizzato da piene di breve durata e di elevato battente idrico, che si registrano generalmente nel tardo autunno, talvolta anche in primavera. nei periodi di precipitazioni scarse, il deflusso superficiale, può ridursi notevolmente fino a quasi annullarsi, per il limitato contributo delle acque sotterranee al deflusso di base. le analisi idrologiche e delle torbide sono state effettuate in corrispondenza di una stazione di misura installata poco a monte della città di stradella. gli eventi di piena primaverili e quelli autunnali, hanno evidenziato non solo diverse concentrazioni torbide, ma anche una diversa concentrazione specifica, soprattutto di taluni metalli pesanti, già riscontrati nei suoli coltivati a vite. nel corso degli eventi di piena, sono state osservate non solo variazioni continue del contenuto mineralogico del sedimento, ma anche un arricchimento nelle classi più fini del trasporto solido, in corrispondenza dell'esaurimento delle piene. le fasi mineralogiche più abbondanti sono i carbonati con tenori medi prossimi al 30%, cui seguono la smectite (circa 22%), altre fasi argillose (la cui sommatoria si aggira attorno al 30%), ed infine i feldspati (11%) ed il quarzo (circa 7%). la variabilità mineralogica mostrata dal trasporto solido rispetto ai suoli dipende dalla forza dell'azione erosiva delle acque superficiali, che, operando un trasporto selettivo di particelle fini, favorisce le argille ed i carbonati rispetto ai silicati. abstract: ciancetti g., dolza g. & pilla g.: the solid transport of the oltrepo pavese minor streams: some peculiar characteristics in the bottom currents content of the t. versa. (it issn 0394-3356, 2008). the studies about superficial waters of pavia's area, managed by the icg laboratory of the earth science department, university of pavia, led us to detect some characteristics that are common to all the little streams that flow in the mountain territory of the oltrepo pavese, with the exception of t. staffora. during this study we analyzed geolithological aspects, climatic conditions, the extent and morphology of basins, soil use and stability. the versa valley, located in the oltrepo area, is devoted to vine growing since the beginning of the last century. agricultural practises and clay-rich soils favour the accumulation of heavy metals such as copper and zinc which are present in applied pesticides. the versa valley may be divided in two different geological sectors, also reflected by the morphological characteristics of the hydrographic basin. the northern part of the valley is hilly and constituted by marls and clay-rich formations, with the sporadic presence of pebblestones, sandstones and limestones. the southern sector is instead dominated by the presence of limestones. the low permeability of the geological formations enhances rainwater runoff rather than infiltration, causing an accelerated soil erosion and a conspicuous transport of suspended matter in rivers and streams. the precipitation pattern in oltrepo shows maximum amounts in november and minimum in august, while throughout the year precipitation is evenly distributed. the versa river discharge is closely correlated to meteoric events and is characterised by short and intense floods, generally occurring in late fall and occasionally in spring. when precipitation is scarce, discharge may decrease and completely disappear, due to a limited groundwater contribution to base flow. a monitoring station for the control of hydrology and turbid sediments has been installed near stradella. fall and spring floods differ not only for the amount, but also for the heavy metals concentration of suspended matter. peculiar links with the mineral phases of the sediment have been evidenced. during a flood, not only continuous changes in the mineralogical content of the solid transport were observed, but also an enrichment in the finest grain sizes during the last phase of the flood. the most abundant mineral phases are carbonates (mean content close to 30%), smectite (about 22%), other clay minerals (adding up to about 30%), feldspars (11%) and quartz (about 7%). comparing this composition with that of the versa valley soils, the identified phases clearly reflect the mineralogical composition of the northern sector, although carbonates are more abundant in the suspended sediment and silicates. parole chiave: deflusso liquido, trasporto solido, erosione dei suoli, metalli pesanti, rame. key words: stream flow, suspended load, soil erosion, heavy metals, copper. il quaternario italian journal of quaternary sciences 21(1b), 2008 161-168 162 ciancetti et al. 1. introduzione la caratteristiche idrodinamiche dei corsi d'acqua minori dell'oltrepo pavese, sono da mettere in relazione con le ridotte dimensioni dei relativi bacini idrografici e con le caratteristiche geologiche e litologiche della zona. la prevalente presenza di formazioni poco permeabili, ad elevata componente argillosa, e la distribuzione dei massimi di precipitazione nei due periodi primaverile ed autunnale, determinano il regime tipicamente torrentizio dei deflussi superficiali. ciò accomuna tutti i corsi d'acqua minori a sud del fiume po, che sono caratterizzati da periodi di magra, anche eccezionali, concentrati nei periodi secchi (inverno e estate) e da periodi di morbida o di piena concentrati come già detto in autunno e primavera. in particolare, le caratteristiche idrometeorologiche e orografiche del bacino del torrente versa, che governano la trasformazione afflusso-deflusso, determinano, specialmente in situazioni di piogge di notevole intensità, o in caso di completa saturazione del bacino, risposte del corso d'acqua in tempi molto brevi, con il sopraggiungere di onde di piena anche molto significative. l'indagine sperimentale sulla risposta idrologica del bacino del t. versa non è ancora purtroppo del tutto completa per poter permettere conclusioni qualificate. ciò nonostante, le osservazioni di questi anni protrattesi dal 2002 ad oggi permettono di identificare alcuni momenti critici per ciò che riguarda il deflusso liquido ed il deflusso torbido. 2. caratteri geomorfologici e geologici il territorio dell'oltrepo pavese è solcato da numerosi piccoli corsi d'acqua che drenano la porzione di territorio collinare e montuosa e confluiscono in destra idrografica nel f. po, dopo aver attraversato un breve tratto di pianura. unica eccezione, per le maggiori dimensioni del bacino e per il regime idrologico è il t. staffora (ciancetti et al., 2001). al primo gruppo di corsi d'acqua appartiene il t. versa, oggetto del presente studio, che si localizza nel settore orientale dell'oltrepo pavese. la valle omonima ha una conformazione allungata con direzione circa n-s e si sviluppa altimetricamente tra i 75 m s.l.m. della confluenza del t. versa nel f. po e i 670 m s.l.m.. essa si sviluppa per una lunghezza totale di circa 30 km e drena, grazie ai vari affluenti, un'area di circa 60 km2. la rete idrografica risulta ben sviluppata, specialmente in presenza di terreni impermeabili o poco permeabili, in cui l'infiltrazione delle acque meteoriche è minima. da un punto di vista geologico (fig. 1) nel bacino del t. versa i terreni maggiormente rappresentati sono costi tuit i da flysch calcareo-marnoso-argil losi (formazione di val luretta) e in subordine da terreni marnoso-argillosi localmente sabbiosi o arenaci (marne di s. agata fossili, marne di monte piano, formazione di montù beccaria, complesso caotico) e, nelle estreme propaggini meridionali del bacino, da arenarie e conglomerati (arenarie di ranzano). nel settore settentrionale lungo le prime colline a ridosso dell'abitato di stradella affiorano inoltre i conglomerati di cassano spinola e la formazione gessoso-solfifera, nella quale sono presenti anche lenti di gesso (beatrizzotti al., 1965, 1969; perotti & vercesi, 1991). il fondovalle lungo cui scorre il t. versa è costituito da una esigua coltre di depositi alluvionali che diviene sempre più potente procedendo verso nord. oltre la città di stradella il corso d'acqua scorre su alluvioni sabbioso-argilloso-limose, dapprima sul proprio conoide, tendendo poi ad insinuarsi nel materasso alluvionale fino alla confluenza nel f. po. le caratteristiche geomorfologiche della valle versa sono, ovviamente, legate alle caratteristiche geolitologiche delle formazioni affioranti. l'assetto del settore meridionale (montano e collinare), è caratterizzato dall'intensità dei processi erosivi e dall' instaurarsi di estesi fenomeni gravitativi costituiti in prevalenza da frane di colamento, rototraslazionali e complesse. in particolare sono presenti fenomeni erosivi concentrati, che danno origine a vaste aree a calanchi. nel settore più settentrionale (basso collinare e di pianura), prevale una morfologia dolce, con pendii più blandi. la degradazione del territorio è legata a cause geologiche, geomorfologiche ed antropiche. le prime dovute alle caratteristiche geomeccaniche delle rocce, che favoriscono l'erodibilità e l'instabilità dei versanti, derivate da intrinseche ragioni lito-strutturali e da un'intensa tettonizzazione, mentre quelle antropiche sono connesse all'attività agricola prevalente e cioè alla coltura della vite che copre più del 50% del territorio (ersaf, 2007). lo sviluppo dei fenomeni di instabilità sui versanti, con frane che giungono, talora, fino al fondovalle, ha determinato modifiche dell'andamento originario del tracciato del torrente, con zone di restringimento e varici, o deviazioni ed anse (rossetti, 1997). 3. acque superficiali le caratteristiche geolitologiche delle formazioni affioranti nel bacino, determinano un differente comportamento idrologico. le formazioni a basso grado di permeabilità, per l'elevata componente argillosa, favoriscono il ruscellamento superficiale piuttosto che l'infiltrazione, anche per questa ragione le risorse idriche sotterranee del settore collinare sono esigue e limitate ad acquiferi di ridotte dimensioni e bassa capacità di immagazzinamento. nel bacino del t. versa sono, infatti, presenti sorgenti con portate molto variabili e normalmente modeste (< 0,5 l/s) e pochi pozzi, localizzati prevalentemente nel materasso alluvionale di fondovalle. in conformità ai caratteri climatici dell'area (rossetti & ottone, 1979), il torrente versa presenta eventi di piena, generalmente in primavera e nel tardo autunno. secondo gli autori citati, la distribuzione delle piogge nell'anno medio calcolato nel periodo 1921-1970, presenta un massimo assoluto nel mese di novembre mentre quello relativo nel mese di maggio. i minimi si concentrano nei mesi di luglio, agosto e secondariamente nel mese di gennaio. osservazioni ulteriori, del decennio 1971-1980, permettono di verificare che si è reso evidente, non solo un forte aumento totale degli afflussi, ma soprattutto, una diversa distribuzione nell'annata, con un aumento dei valori relativi ai mesi di gennaio, febbraio, agosto, settembre ed ottobre, ed una marcata diminuzione nei mesi di novembre e dicembre. i valori cumulati su più giorni mostrano che i massimi derivano dalla somma di un giorno di precipitazioni intense con altri nella norma o addirittura sotto la norma e che il valore in assoluto maggiore nel decen163il trasporto solido nei corsi d’acqua ... fig. 1 carta geologica del bacino del torrente versa. geological map of the river versa basin. nio è stato registrato nel mese di agosto 1975 (ro s s e t t i, 1997). questi elementi si riscontrano nei deflussi del t. v e r s a1 dove la trasformazione afflusso-deflusso, specialmente in situazioni di piogge di notevole intensità, determina, in caso di saturazione del bacino già presente, risposte del corso d'acqua in tempi molto brevi, con la formazione di onde di piena anche molto significative, come sono state osservate recentemente nel mese di agosto dell'anno 2006 e del 20072. le osservazioni dei battenti idrici degli ultimi due anni hanno evidenziato che i maggiori deflussi superficiali si sono registrati in corrispondenza di forti temporali estivi o tardo estivi, mentre le piogge autunnali e primaverili hanno determinato incrementi dei battenti idrici non altrettanto elevati. negli anni di osservazione (2002-2007) i massimi battenti idrici osservati (ad eccezione dei due eventi citati) si sono mantenuti sempre al disotto di + 1,70 m rispetto allo zero idrometrico corrispondenti a portate inferiori a circa 9 m3/s. gli incrementi estivi sono stati così intensi da superare quota + 2,10 m rispetto allo zero idrometrico (q > 11 m3/s) nell'agosto 2006 e circa quota + 3,20 m (q > 17 m3/s), nello stesso mese dell'anno successivo, raggiungendo l'impianto di registrazione posto in un armadio a tenuta stagna, distruggendo la sonda torbidometrica e quella di misura dei battenti idrici. 4. trasporto solido il trasporto solido è un fenomeno dipendente da fattori climatici, geo-litologici, geomorfologici, antropici che gestiscono le trasformazioni alla scala dell'intero bacino, e quelle locali che interessano il corso d'acqua che drena il bacino. questi fattori possono influire sul regime del trasporto solido in corrente, operando in tempi molto diversi fra loro. per lo studio del trasporto solido spesso il limite delle analisi è determinato dalla ridotta osservazione temporale del fenomeno. nei piccoli corsi d'acqua, gli elementi fondamentali del bilancio relativo al trasporto torbido, sono la disponibilità del sedimento e la capacità di trasporto da parte della corrente. questi due elementi possono agire diversamente in funzione delle caratteristiche geomorfologiche del bacino e dell' uso del suolo. le caratteristiche litologiche delle formazioni affioranti nel bacino del t. versa caratterizzate da un basso grado di permeabilità, per l'elevata componente argillosa presente, favoriscono il ruscellamento superficiale, a ciò dà un forte contributo l'uomo che con la preponderante coltura viticola a filari, e con la pratica agricola della lavorazione interfilare nei terreni declivi con il sistema di aratura e fresatura a "ritocchino", vale a dire seguendo le linee di massima pendenza, favorisce lo scorrimento dell'acqua lungo solchi, in cui si concentra l'erosione ed il successivo trasporto di grandi quantità di materiale. il trasporto solido del torrente versa è stato campionato durante alcuni eventi di piena autunnale e primaverile, permettendo di determinare la concentrazione sol ida (g/l). i pr imi campionamenti, realizzati a stradella, sono stati sporadici e puntuali, hanno pertanto potuto fornire solo stime della quantità di materiale in sospensione al momento del campionamento. l'installazione e la taratura di una stazione di misura del deflusso liquido, equipaggiata successivamente (2005) con un torbidimetro (endress+hauser liquisys m cum 252) per la misura in continuo della torbidità, posta in corrispondenza del ponte della s.p. 43, che collega la s.p. 201 di fondovalle all'abitato di montù beccaria (fig. 1), ha consentito la valutazione del trasporto solido in sospensione in occasione di alcuni eventi di piena. e' importante sottolineare che i campionamenti della torbidità effettuati in precedenza e durante le prime fasi dell'installazione della sonda torbidometrica, sono stati eseguiti, ad intervalli di tempo predefiniti, con un campionatore automatico. il periodo più significativo per il trasporto solido in sospensione, è risultato in condizioni normali, quello autunnale, caratterizzato da eventi di piena di maggiori dimensioni (fig. 2), rispetto al periodo primaverile (fig. 3). questa caratteristica sembra essere legata alle scarse precipitazioni ed alla forte esposizione solare dei terreni durante la stagione estiva, che provoca una “maturazione” del suolo a cui, come già detto, fornisce un forte contributo l'attività antropica legata alla coltura della vite ed alle operazioni ad essa connesse proprio nel periodo primaverile ed estivo. ne risulta che le piogge autunnali, soprattutto se intense ed abbondanti, riescono ad avere una maggiore efficacia erosiva, determinando nei corsi d'acqua elevati valori di concentrazione solida. i picchi di torbidità risultano circa contemporanei, o di poco successivi, al colmo dei deflussi liquidi, (fig. 2-3) con valori variabili da 0,2 g/l a 0,4 g/l per le piene primaverili, a valori compresi tra 0,8 e circa 10,0 g/l per quelle autunnali (tab. 1). malauguratamente gli eventi estivi dell'agosto 2006 e 2007 non sono stati registrati, il primo, per problemi tecnici, il secondo, per aver causato la completa distruzione della stazione. 4.1 analisi dei sedimenti sulla fase solida sono state effettuate delle analisi m i n e r a l o g i c h e3 mediante diffratometria a raggi x , metodo delle polveri. la variabilità stagionale della torbidità specifica, si riscontra anche nella composizione mineralogica. nella figura 4 sono riportati i valori medi, minimi e massimi, espressi in percentuale, di ciascuna fase 164 1 per gli studi di carattere idrologico , è stata installata nel 2002 una stazione idrometrica presso il ponte (circa 2 km a monte di stradella) che dalla s.p. 201 di fondovalle, porta a montù beccaria, in un tratto in cui il corso d'acqua presenta ancora indice di sinuosità relativamente basso. 2 l'alluvione del 31 agosto 2007, è stata determinata da una meteora estesa a buona parte del settore meridionale dell'oltrepo pavese che “ha fatto precipitare in una sola notte 100 mm di pioggia, mettendo in ginocchio l'oltrepo orientale con allagamenti e smottamenti”. richiesta di stanziamenti straordinari per calamità naturali. camera dei deputati seduta n°231 . ne danno conferma i dati registrati dalla stazione pluviometrica situata presso il dipartimento di scienze della terra dell'università di pavia, che pur distando circa 20 km dall'areale colpito dal centro della meteora, ha registrato l'afflusso di 64 mm in 10 ore, con punte di 22 e 25,8 mm, rispettivamente alle ore due e tre del 31 agosto. 3 le analisi mineralogiche del particellato solido, sono state effettuate presso il laboratorio “raggi x” del dipartimento di scienze della terra, dell'università di pavia, dal prof. setti m. ciancetti et al. 165 fig. 2 idrogramma e torbidogramma registrati nel mese di novembre 2003. water and suspended sediment discharges, recorded in november 2003. fig. 3 idrogramma e torbidogramma registrati nel mese di aprile 2004. water and suspended sediment discharges, recorded in april 2004. il trasporto solido nei corsi d’acqua ... fig. 4 composizione mineralogica media, minima e massima delle torbide. average, minimum and maximum mineralogical composition of the suspended sediment discharge. mineralogica individuata. le fasi mineralogiche più abbondanti sono rappresentate dai carbonati con valori medi pari a circa al 28%, cui seguono la smectite (circa 22%), seguiti dalle altre fasi. confrontando questa composizione con quella dei suoli della valle versa, si osserva che le fasi identificate sono ben rappresentate nella media-bassa valle, anche se i carbonati risultano più abbondanti nelle torbide che nei suoli, mentre i silicati, come il quarzo ed i feldspati, sono invece, maggiormente presenti nei suoli. nella porzione più meridionale della valle, la smectite risulta essere la fase dominante con quantitativi maggiori del 60% (ersaf 2007; ciancetti et al., 2007). la diversa abbondanza mineralogica riscontrata nelle torbide in generale rispetto ai suoli, o all'interno delle varie fasi delle torbide stesse, dipende dalla capacità erosiva delle acque di corrivazione, che operano un trasporto selettivo delle parti più fini (wash load), determinando maggiori concentrazioni dei minerali argillosi e dei carbonati rispetto ai silicati, durante la fase di esaurimento dell'evento, quando l'energia diminuisce progressivamente. nella figura 5 sono state inserite le analisi sul contenuto in rame dei campioni di materiale prelevato durante la piena, che permettono di effettuare ulteriori considerazioni. come si può osservare, la concentrazione in rame nei vari campioni, segue abbastanza fedelmente la grafica del contenuto dei carbonati, mentre le argille ed i silicati presentano andamenti diversi. il grafico suggerisce quindi (ersaf 2007) che parte del rame possa essere trasportato come fase fissata ai carbonati. il ruolo dei carbonati nel fissare il rame, appare in altre circostanze (campionamenti non inclusi nella presente nota), meno marcato, assumendo maggior rilievo quello delle argille, in particolare della smectite. i risultati delle analisi chimiche realizzate sul materiale campionato durante eventi di piena sono riportati in tabella 1. i primi due campionamenti pur essendo stati eseguiti in momenti non precisati delle piene, prelevando una notevole quantità di torbida, sono stati inseriti nella tabella, in quanto indicativi del diverso contenuto solido fra le piene primaverili e quelle autunnali, come reso evidente dai successivi campionamenti effettuati in continuo. nel trasporto solido, il cu raggiunge gli stessi valori osservati nei suoli adibiti alla coltivazione della vite, a testimoniare come una parte di questi suoli venga stagionalmente erosa (ersaf 2007). inoltre, come già evidenziato, sono le piene autunnali quelle più importanti sia in termini di quantità di acqua che di solido trasportato. analogamente a quanto osservato nel paragrafo del trasporto solido, le piene che si succedono in tempi molto brevi, a distanza di pochi giorni, mostrano non solo una minore concentrazione solida, ma anche un progressivo abbassamento del tenore in rame. la figura 6 evidenzia un ulteriore ed interessante elemento, che conferma quanto già espresso, e cioè che all'aumentare della concentrazione solida corrisponde una progressiva diminuzione del contenuto in rame nel trasporto solido, la cui concentrazione aumenta invece, nelle acque (deflusso liquido). questo fenomeno è giustificato dalla diversa energia del mezzo, infatti alla maggiore capacità di trasporto corrisponde non solo una maggiore quantità di sedimento ma anche maggiori dimensioni dello stesso. ne consegue una proporzionale diminuzione del metallo nel trasporto solido in quanto esso risulta di preferenza fissato alle taglie più fini (ad elevata superficie specifica) del wash load (ciancetti et al., 2007; ersaf 2007). 166 fig. 5 contenuto mineralogico della piena del novembre 2003, il cui torbidogramma è rappresentato nella figura 2. le variazioni del contenuto nei diversi minerali sono confrontate con il contenuto in rame legato ai solidi. mineralogical content of november 2003, flood event in, whose suspended sediment discharge is shown in figure 2. changes in the content of the different minerals are compared with the copper content related to solids. ciancetti et al. 167 tab. 1 contenuto solido e concentrazione del rame nelle acque di alcune piene. solid content and copper concentrations of the waters of some flood events. il trasporto solido nei corsi d’acqua ... fig. 6 variazioni della concentrazione del rame nelle torbide e nelle acque, in relazione alla concentrazione solida. copper concentration in water and in suspended sediment discharge, related to the solid concentration. 5. conclusioni il bacino del t. versa, può essere considerato rappresentativo dei bacini minori (escludendo pertanto la valle staffora) dell'oltrepo pavese. le dimensioni, le caratteristiche geo-litologiche , la morfologia, l'uso del suolo, con la coltura della vite che interessa più del 50% del territorio, costituiscono infatti caratteri comuni. lo studio idrologico sviluppato può rappresentare la complessità dei fenomeni che avvengono in questo settore dell'area oltrepadana. lo studio, mirato alla definizione degli elementi di base delle conoscenze territoriali (comprensione dei processi idrologici ed erosivi) ha cercato di definire la trasformazione afflussi-deflussi, confrontandola con le caratteristiche climatiche (storiche ed attuali) dell'area, mettendo in evidenza come l'uso del suolo determini il valore ed il contenuto del trasporto solido in sospensione. ulteriori ricerche in corso mirano a definire nei suoi valori totali il deflusso torbido, consentendo di valutare il coefficiente di erosione a cui il bacino è sottoposto (perdita di suolo). i caratteri climatici, restringono al periodo autunnale il momento di maggior rischio idrologico dell'area, anche se le osservazioni presentano taluni eventi critici, in seguito ad afflussi meteorici di particolare rilevanza, avvenuti nei mesi estivi (nel 1975 e poi nel 2006 e nel 2007). per quanto riguarda il trasporto solido, alla capacità erosiva dell'acqua di corrivazione sui terreni coltivati a vitigno del bacino, si deve aggiungere la notevole quantità di materiale resa disponibile dai dissesti. l'area è infatti interessata da estesi movimenti franosi, molto comuni in tutto l'oltrepo pavese, la cui causa è da ricondursi principalmente alle caratteristiche geomeccaniche delle formazioni più diffusamente affioranti, costituite in prevalenza da litotipi argillosi, che in condizioni di forte saturazione, si vengono a trovare in breve tempo in situazioni di elevata instabilità. il materiale mobilizzato dai dissesti, subisce più intensi fenomeni di erosione diffusa e/o concentrata, particolarmente in corrispondenza dei versanti più acclivi. queste condizioni di degradazione del territorio, naturali e antropiche, favorendo l'erosione del suolo, determinano, specie durante le piene autunnali, elevate concentrazioni torbide. la concentrazione dei solidi sospesi (torbida), misurata durante alcuni eventi, ha raggiunto valori prossimi a 10 g/l. l'analisi mineralogica e chimica del particellato, ha messo in luce il particolare contenuto delle torbide, in cui, agli elementi presenti come costituenti mineralogici dei terreni, si aggiunge un elevato contenuto in metalli pesanti, in particolare il rame, proveniente dalle porzioni superficiali dei suoli asportati dalle acque di corrivazione nelle aree coltivate a vite. bibliografia be a t r i z z o t t i g., be l l i n z o n a g., be l t r a m i g., bo n i a . , br a g a g. & mo s n a s. (1965) carta geologica d'italia scala 1:100000, f. 59 pavia. ii edizione, servizio geologico d'italia, roma. be a t r i z z o t t i g., be l l i n z o n a g., be l t r a m i g., bo n i a . , braga g., marchetti g. & mosna s. (1969) carta geologica d'italia scala 1:100000, f. 71 voghera. ii edizione, servizio geologico d'italia, roma. bellinzona g., boni a., braga g. & marchetti g. (1971) note illustrative della carta geologica d'italia, foglio 71 voghera. nuova tecnica grafica, roma. bo n i a. (1967) note illustrative della carta geologica d'italia, foglio 59 pavia.” nuova tecnica grafica, roma. ci a n c e t t i g., ga l l i n a a., pennacchioni e. & pi l l a g . (2001) sul trasporto solido e sulle variazioni morfologiche del t. staffora (appennino pavese). mem. soc. geol. it., 56, pp. 265-274. ci a n c e t t i g., do l z a g., pi l l a g., sacchi e. & se t t i m . (2007) i metalli pesanti nel trasporto solido del t. versa. geoitalia 2007. sesto forum italiano di scienze della terra; rimini, 12-14 settembre 2007. er s a f ( 2004) suoli e paesaggi della provincia di pavia. regione lombardia, milano. er s a f (2007) analisi del contenuto in rame ed altri metalli nei suoli agricoli lombardi. ramet. aa.vv. quaderni della ricerca, 61, milano. perotti c.r. & vercesi p.l. (1991) assetto tettonico ed evoluzione recente della porzione nord-occidentale dell'appennino emiliano. mem. descr. carta geol. d'it., 46, pp. 313-326. ro s s e t t i r. & ot t o n e c. (1979) esame preliminare delle condizioni pluviometriche dell'oltrepò pavese e dei valori critici delle precipitazioni, in relazione ai fenomeni di dissesto franoso. geol. appl. e idrogeologia, 14/3, pp. 83-99. ro s s e t t i r. (1997) centri abitati instabili della provincia di pavia. c.n.r. g.n.d.g.c.i., linea di ricerca 2, progetto speciale s.c.a.i. resp. r. rossetti; g. ciancetti (dal 1997). 168 ms. ricevuto il 1° marzo 2008 testo definitivo ricevuto il 20 aprile 2008 ms. received: march 1, 2008 final text received: april 20, 2008 ciancetti et al. composizione geochimica del solido sospeso fluviale: uno strumento per l'analisi ambientale dimitra rapti-caputo1, donatella pavanelli2 & carmela vaccaro1 1 università di ferrara, dipartimento di scienze della terra, via saragat, 1, i-44100 ferrara italia; e-mail: cpr@unife.it 2 università degli studi di bologna, dipartimento di scienze della terra e geologico-ambientali, via zamboni 64, 40126 bologna riassunto: rapti-caputo d., pavanelli d. & vaccaro c.: composizione geochimica del solido sospeso fluviale: uno strumento per l'analisi ambientale (it issn 0394-3356, 2008). nel presente lavoro, vengono presentati i risultati preliminari relativi alla definizione dello stato ambientale dei bacini idrografici con l'ausilio di metodi geochimici ed idrologici. in particolare, in una rete di monitoraggio idrologico relativa a quattro affluenti del fiume reno, quali gaiana, lavino, sillaro e savena, è stato campionato il materiale solido sospeso durante il periodo di piena. l'analisi chimica del solido sospeso tramite fluorescenza a raggi x ha permesso di definire la composizione geochimica dei sedimenti e la relazione con le formazioni litologiche affioranti nei bacini e di determinare i tenori di fondo attuali relativi alle grandezze geochimiche analizzate. abstract: rapti-caputo d., pavanelli d. & vaccaro c.: geochimical composition of the fluvial suspended load: a tool environmental analyses (it issn 0394-3356, 2008). the preliminary results based on a geochemical and hydrological approach and aimed at defining the environmental conditions of the reno hydrographic basin, northern italy, are presented. the environmental conditions of the discussed case study are determined with a geochemical analysis of the solid suspended load carried out for the four major hydrographic sub-basins (gaiana, lavino, sillaro and savena). the chemical analyses of the fluvial suspended load was carried out during extreme flow events. the collected sediments were analysed with the x-ray fluorescence method thus allowing to define the geochemical composition of the sediments and their relation with the rocks outcropping within the hydrographic basins as well as the present-day background values of the principal chemical elements parole chiave: fiume reno, solidi sospesi, geochimica, analisi ambientale. key words: reno river, suspended sediment load, geochemistry, environmental analysis. il quaternario italian journal of quaternary sciences 21(1b), 2008 169-182 1. introduzione il trasporto torbido dei corsi d'acqua è costituito da solidi in sospensione di granulometria variabile, dalle argille alle sabbie, in funzione dei parametri idraulici, litopedologici e vegetazionali del bacino. numerose sono le indagini sui processi di trasporto che concordano nell'attribuire ai solidi sospesi il ruolo di veicolo per la migrazione degli agenti inquinanti e dei nutrienti (bu e s e l i n c k et al., 2000; ho r o w i t z, 1991; pa v a n e l l i & bigi, 2004). la concentrazione di tali sostanze nei solidi in sospensione può arrivare a diversi ordini di grandezza maggiori rispetto alla loro concentrazione nella frazione liquida, in fase disciolta. in particolare è stato provato il ruolo di vettore preferenziale degli aggregati di particelle fini come argilla e limo (dr o p p o et al., 1997; ongley et al., 1992). la necessità di dati sperimentali rende il monitoraggio fluviale un basilare tassello nella gestione e protezione dell'ambiente dato che la composizione geochimica del materiale solido sospeso permette di definire i tenori di fondo delle diverse grandezze geochimiche, e conseguentemente, di valutare i fenomeni di contaminazione e/o inquinamento dei sedimenti. in questo contesto va inquadrata la presente ricerca della quale si presentano i risultati preliminari relativi alla caratterizzazione geochimica del materiale solido sospeso di quattro affluenti dell'asta fluviale del fiume reno: i torrenti sillaro, gaiana, lavino e savena (fig. 1). 2. approccio metodologico la definizione della composizione geochimica del materiale solido sospeso si è basata su una rete di monitoraggio fluviale (avviata col contributo dell'autorità di bacino del reno e responsabile scientifico la dr. pavanelli), che vede attive quattro stazioni di rilevamento idrologico-torbidimetrico (fig. 2_stazione foto), in continuo, lungo i torrenti sillaro, gaiana, lavino e savena (pavanelli, 2000; pavanelli & pagliarani, 2002; pa v a n e l l i & bi g i, 2005a; 2005b; pa v a n e l l i & ri g o t t i, 2007). in particolare, i torrenti sono stati attrezzati, alla chiusura del bacino montano, con idrometro ad ultrasuoni e campionatore automatico per le torbide; mentre, il campionamento è stato programmato in funzione del volume d'acqua defluito dalla sezione (pavanelli et al., 2004). tale metodo di campionamento delle torbide consente di prelevare un numero di campioni, per ciascun 170 rapti caputo et al. evento, in relazione alla portata e, quindi, alla magnitudine dell'evento stesso. di conseguenza i campionamenti sono stati concentrati nelle fasi idrologiche più interessanti per lo studio del trasporto torbido rappresentati dai periodi di piena. nel caso specifico, per poter effettuare analisi geochimiche sul materiale in sospensione, nella scelta della strumentazione e della campagna di rilevamento, si è tenuto conto anche della necessità di una quantità significativa di materiale solido (>10 g), il che può risultare un problema nel caso che la strategia di campionamento non sia adeguata alla natura altamente episodica delle piene e delle torbide fluviali (wa l l i n g et al., 1992). i campioni dell'acqua ed il solido sospeso in essi contenuto, relativi agli eventi di torbida, sono stati selezionati sulla base del la portata e quindi del la magnitudine dell'evento stesso, in modo da ottenere i volumi di sedimento necessari per una completa caratterizzazione geochimica. i campioni selezionati per questa prima fase del lavoro di adeguata concentrazione di solidi in sospensione sono stati sottoposti ad analisi fisiche ed chimiche. in particolare, le analisi fisiche (realizzate presso i laboratori del la sez ione provincia le di ravenna dell'agenzia regionale prevenzione ambiente) sono le seguenti: a) determinazione dei solidi residui mediante analisi gravimetrica e separazione dei sol idi sospesi . in questa fase, per la separazione della frazione liquida dai solidi sospesi , i campioni sono sottoposti a filtrazione con filtri 0,45 µm, dopo preventiva sedimentazione e, se necessaria, centrifugazione. la parte solida così risultante viene inizialmente essiccata a 105 °c fino al raggiungimento del peso costante; ed in seguito pesata per la determinazione dei solidi sospesi. b) realizzazione di analisi granulometr iche adottando il “metodo della pipetta” che si basa su criteri idrodinamici, fondati sulla differenza di velocità relativa di caduta delle particelle nel fluido, in cui sono immerse secondo la legge di stokes. in tale modo sono state determinate le frazioni granulometriche relative a sabbia (2000 ÷ 50 µm); limo grossolano (50 ÷ 20 µm); limo fine (20 ÷ 2 µm) ed argilla (< 2 µm). infine, nella frazione fine cosi ottenuta (insieme delle particelle elementari con ø < a 2 µm) è stata inizialmente eliminata la parte organica e, successivamente sottoposta ad analisi chimica. fig. 1 bacino idrografico del fiume reno (i triangoli rappresentano le stazioni di monitoraggio del materiale solido sospeso). hydrographic basin of the reno river (triangles represent the monitoring stations for the suspended load). fig. 2 stazione di monitoraggio idro-torbidimetrico sul sillaro. hydro-turbidometric monitoring station along the sillaro torrent. c) analisi chimiche mediante fluorescenza a raggi x. la frazione granulometrica fine (particelle elementari con ø < a 2 µm), relativa a 39 campioni (17: gaiana, 9: sillaro, 8: lavino, 5: savena) è stata sottoposta alle analisi composizionali, per determinare la l.o.i. (loss of ignition), e ad analisi chimiche degli elementi maggiori, mediante fluorescenza a raggi x (modello advant xp della thermo arl), utilizzando una configurazione a dispersione di lunghezza d'onda con valori di tensione e corrente compresi nell'intervallo 30-50 kv e 30-50 ma, con anodo di cromo per gli elementi leggeri e di tungsteno per quelli pesanti. l'utilizzo della fluorescenza a raggi x, in accordo con il metodo proposto da fr a n z i n i et al. (1975), ha consentito la determinazione quantitativa degli elementi maggiori (sio2, tio2, al2o3, fe2o3, mgo, mno, cao, n a2o, k2o, p2o5) espressi in percentuale in peso (wt%); mentre, le concentrazioni relative agli elementi in tracce, sono stati ottenuti calcolando sperimentalmente i coefficienti di correzione. l'accuratezza e la precisione per gli elementi in tracce (in ppm) per concentrazioni superiori a 10 ppm è maggiore del 7%, per il rb, nb, sr, v; e maggiore del 15%, per zr, ba, ni, co, cr, terre rare (ree), e y. 3. inquadramento ambientale del bacino del reno il fiume reno, il più importante dei fiumi emilianoromagnoli; nasce in toscana ad una quota di circa 740 m slm dalla confluenza del reno di prunetta e del reno di capoluogo. il bacino idrografico ha un' estensione di circa 4953 km2 e possono distinguere: a) undici sottobacini idrografici con estensione areale superiore a 40 km2, comprendenti il torrente setta ed il suo affluente brasimone; ed i torrenti limentra di treppio, silla; vergatello, limentra di sambuca e samoggia con l'affluente lavino, idice, sillaro, savena, santerno e senio; e b) undici affluenti, con estensione dei relativi bacini idrografici, comprese tra i 10 e i 40 km2 quali i torrenti sembro, gabellato e voglio affluenti del torrente setta; il torrente aneva affluente del vergatelo, i torrenti venola, maresca, marano, rio maggiore, orsigna, croata e randaragna. il ramo principale del fiume reno ha una lunghezza di circa 210 km suddiviso in due aree con caratteristiche idrauliche differenziate che consistono in una parte montana appenninica, estesa fino a località casalecchio nei pressi del centro urbano di bologna, caratterizzata da regime torrentizio ed un settore a basso gradiente topografico, impostato sui depositi terrazzati antichi e nei sedimenti alluvionali recenti per sfociare, infine, nel mare adriatico immediatamente a sud delle valli di comacchio (fig. 1). nella zona di pianura, le acque del reno per motivi di sicurezza idraulica sono state deviate in canali artificiali di grandi dimensioni quali il cavo napoleonico, il canale navile ed il canale savena. la superficie dei bacini dei quattro affluenti del reno attualmente monitorati copre complessivamente un'area di 389 km2. tali bacini hanno una forma stretta ed allungata (direzione: sudovest-nordest), fattore che accentua il carattere tipicamente torrentizio, con piene 171composizione geochimica del solido sospeso ... repentine e, a volte, rovinose. la precipitazione media annua sul bacino montano è di circa di 1000 mm. 3.1 il bacino idrografico del lavino il torrente lavino, affluente in destra idrografica del fiume samoggia, ha origine in località croce delle pradole, nei pressi di montepastore, sull'appennino emiliano. il suo corso principale viene alimentato da quattro affluenti principali, due in sinistra e due in destra, alimentati da numerosi subaffluenti di lunghezza modesta a regime tipicamente torrentizio. il bacino montano del lavino ha una estensione di 83,6 km2, a fronte di un reticolo idrografico di 175,7 km. la pendenza media del bacino è di 2,9 % , mentre, solo il 25% dei terreni ubicati nel bacino montano hanno una pendenza superiore al 35 %. l'altitudine media è di 370 m, con quote comprese tra 75 m e 776 m. dal punto di vista geologico (fig. 3, tab i), nel bacino del lavino si ha la predominanza di (da carta dell'uso del suolo e carta geologica di pianura dell'emilia romagna i n www.regione.emilia-romagna.it) argille scagliose o “caotico eterogeneo” (e). questa formazione costituisce un substrato alloctono eterogeneo di origine pliocenica, formato da una matrice plastica prevalentemente argillosa, inglobante calcari, arenarie, marne ed i cosiddetti “red beds”, argille dal caratteristico colore vinato o verdastro (h). l'altra formazione litologica, meno ricorrente, è rappresentata da marne depositate e cementate di età elveziana in successione alle argille scagliose (c). caratteristica di tale marne sono le dense fratture in blocchetti irregolarmente conformati, spesso arrossati per la presenza di ossidi di ferro o anneriti da ossidi di manganese (fig. 3, tab i) il torrente lavino presenta un deflusso torbido unitario medio di 1,89 t/ha, corrispondente ad un denudamento medio annuo di circa 0,13 mm (pa v a n e l l i e t al., 2004) i suoli siti nel bacino montano del torrente lavino sono generalmente di modesto valore agronomico. l'insediamento antropico presenta una intensità decrescente risalendo l'asta del torrente. 3.2 il bacino idrografico del sillaro il torrente sillaro, affluente in destra del reno, ha origine nell'appennino presso piancaldoli (fi), si addentra in emilia in corrispondenza di giugnola e prosegue il suo corso in direzione n-ne segnando il confine geografico tra l'emilia e la romagna. in comune di castel san pietro (prov. bologna) si chiude il bacino montano. l'idrografia del bacino presenta un'elevata densità di drenaggio con il tipico andamento dendritico indicativo della presenza di formazioni litologiche a bassa permeabilità. il reticolo idrografico comprende 16 affluenti principali, di cui 13 in sinistra idrografica e 3 in destra. dal punto di vista geologico (fig. 3, tab i), il bacino riveste particolare importanza poiché rappresenta il raccordo tra il limite occidentale delle unità liguri o liguridi, caratterizzanti il settore emiliano; ed il limite orientale del dominio umbro marnoso-arenaceo tipico del settore romagnolo. questa zona di contatto tra le due differenti formazioni viene chiamata “linea del sillaro”. in particolare, verso sud, al confine con la toscana, il bacino insiste su lembi della formazione “marnoso-arenacea” costituita dall'alternanza di arenarie e marne (h), mentre il restante si estende in gran parte sul “caotico eterogeneo” (e), costituito prevalentemente da argille grigiastre che, in seguito a complessi fenomeni tettonici hanno assunto un alto grado di caoticità inglobando al loro interno, come corpi alloctoni, formazioni di età e litologia diversa. procedendo verso nord, si incontrano rocce sedimentarie di ambiente lacustre come le evaporiti messiniane (formazione gessoso-solfiera), i conglomerati e le sabbie del pliocene inferiore, le argille e le argillemarnose del pliocene medio superiore e le argille sabbiose del calabriano (1; fig. 3, tab i) dal punto di vista pedologico, il bacino è prevalentemente interessato da regosuoli, suoli bruni e pseudogley, suoli tipici che evolvono su associazioni argillose. i suoli più evoluti si incontrano sulle pendici boscate. i più diffusi sono i regosuoli, poco profondi e con abbondante scheletro. il bacino montano ha un'estensione di 123,3 km2, con quote comprese tra i 68 ed i 993 m slm. la morfologia è generalmente abbastanza dolce e solamente il 7,6% del bacino presenta pendenze superiori al 35%, tranne nei settori caratterizzati da un paesaggio calanchivo. per quanto riguarda la copertura vegetale (tab. ii) il bacino è interessato da bosco ceduo spesso degradato (14%), zone sterili per affioramento roccioso e/o copertura vegetale carente (49%), pascolo (6%) e, dove la pendenza lo consente, da seminativo (17%). la parte restante è interessata da vigneti, frutteti, corpi idrici, insediamenti, ecc. il torrente sillaro presenta un deflusso torbido unitario medio di 10,1 t/ha, corrispondente ad un denudamento medio annuo di circa 0,67 mm (pavanelli et al. 2004). valori simili sono stati documentati anche per altri torrenti appenninici limitrofi (bartolini et al., 1996). 3.3 il bacino idrografico del gaiana il torrente gaiana nasce sull'appennino emiliano presso il versante nord tra palgone e ca' de'belli ad una quota di 312 m s l m. confina in destra idrografica con il torrente sillaro e in sinistra con il torrente quaderna affluente dell'idice. si sviluppa prevalentemente in direzione n-ne per poi confluire nel torrente quaderna. presenta le tipiche caratteristiche di un torrente appenninico, una dominante litologia sedimentaria e un drenaggio dendritico con elevata densità. il bacino idrografico del torrente gaiana presenta una superficie di 8,7 km2, altitudine media di 237 m, slm (quote variabili tra 101 e 495 m, slm), e si chiude presso casalecchio dei conti, all'altezza della via emilia. dal punto di vista geologico (fig. 3, tab i) il bacino del torrente gaiana è caratterizzato da una prevalenza di argille, argilliti e brecce argillose con clasti eterometrici e scaglie di calcari marnosi, marne, arenarie ed 172 fig. 3 -ripartizione in classi litologiche dei bacini idrografici (per la simbologia delle classi litologiche vedi tabella i). lithological classes of the hydrographic basins (see table i for symbols). rapti caputo et al. 173 tab. i composizione geolitologica dei bacini idrografici (classe e caratteristiche specifiche). table i geolithological composition of the hydrographic basins (class and specific characteristics) composizione geochimica del solido sospeso ... ofiol it i facenti parte della formazione “marnoso arenacea” (h), nonché argille e marne con intercalazioni di areniti (c) e successioni prevalentemente costituite da alternanze di areniti e peliti, generalmente torbidiche che si estendono sul “caotico eterogeneo”(e). per quel che riguarda l'uso del suolo è da sottolineare la prevalente vocazione colturale del territorio, in particolare si tratta di colture a seminativo (s in tab. ii;) e in minor misura attività agricole eterogenee (ze). 3.4 il bacino idrografico del savena il bacino montano del savena è di circa 123,8 km2 e presenta quote comprese tra 200 e 1275 m slm. trae origine da tre rii, detti le tre savenelle, in territorio toscano, che scendono da un anfiteatro la cui vetta più alta arriva a 1302 m. la densità del reticolo idrografico è elevata, e i numerosi affluenti presentano un andamento pressoché perpendicolare al savena e uno sviluppo, in lunghezza, contenuto a causa della caratteristica forma del bacino stretta e lunga, come peraltro tutti i bacini di questo settore dell'appennino. tale idrografia, assieme al regime delle precipitazioni, contraddistingue il carattere torrentizio del savena. peraltro, la presenza di numerose sorgenti favorisce la continuità di portata anche durante i periodi estivi. dal punto di vista geologico (fig. 3, tab i), il bacino del torrente savena è caratterizzato, in sinistra idrografica, dalla presenza di una successione di sabbie e areniti poco cementate (b), areniti e peliti, generalmente torbidiche (e), con alternanze di marne, strati potentissimi di argille (dal colore turchino, dovuto alla presenza di una forma di ferro ridotto), calcari, con intervalli pelitico arenacei, di origine torbidica, talora intensamente deformati e fratturati (g). la parte destra della vallata è, invece, caratterizzata da importanti formazioni gessose associate a marne. proseguendo verso la pianura, la litologia diventa prevalentemente argillosa. parte del territorio di pianoro presenta fenomeni carsici caratterizzati da inghiottitoi e grotte, originati da formazioni evaporitiche dei gessi miocenici (fig. 3, tab. i). risulta evidente la diversa caratterizzazione geolitologica del savena rispetto agli altri bacini. tale bacino è, infatti, contraddistinto dalla presenza di una decisa componente calcarea oltre che dall'argilla (tab. i). nell'area collinare, i versanti sono, specie in sinistra idrografica, ad elevata acclività e sono interessati per lo più da boschi di latifoglie. nella fascia tra i 300 ed i 1000 m, sono presenti i castagneti. nella porzione valliva predominano le formazioni a litologia argillosa, quali le argille scagliose, con pendenze minori, interessate da seminativi e pascoli e da frequenti fenomeni di erosione e dissesto. il progressivo abbandono dell'agricoltura fa si che oltre il 20% della superficie agraria sia a pascolo o incolto. infine, il torrente savena presenta un deflusso torbido unitario medio di 6,5 t/ha, corrispondente ad un denudamento medio annuo di circa 0,43 mm (pavanelli et al., 2004). 4. uso del suolo per quel che riguarda l'uso del suolo nei quattro bacini (tab. ii) è da sottolineare la prevalente vocazione colturale del territorio; in particolare si tratta di colture a seminativo (s) e in minor misura attività agricole eterogenee (ze), in quanto rappresentano per tre bacini su quattro la destinazione d'uso privilegiata. tale condizione è rappresentativa della connessione tra uomo e territorio che si è sviluppata nel corso dei secoli in queste terre, e che ancora si manifesta ai giorni nostri, ma che in un futuro prossimo sarà destinata a vedere diminuire la percentuale di zone destinate all'uso agricolo a causa dell'abbandono delle terre da parte dei proprietari, soprattutto in quelle zone dove le caratteristiche morfologiche del territorio rendono difficile l'applicazione di un'efficace meccanizzazione che porti ad un'agricoltura più redditizia. una situazione di questo genere è resa particolarmente evidente dalla massiccia presenza di aree a cespuglieti (zs), caratteristica vegetazione rappresentativa di una condizione di transizione che si evolve verso un ecosistema di tipo naturalistico, con formazioni boschive, soprattutto di latifoglie, che già figurano ben presenti in tutti i bacini (b). nei confinanti bacini del gaiana e sillaro si può notare la marcata presenza di aree ad affioramenti litoidi (zr), caratteristica infatti di tale porzione di territorio sono le formazioni calanchive. l'abbandono dei terreni agricoli avrà di certo una ripercussione anche sui fenomeni di dissesto idrogeologico che già interessano particolarmente questa porzione di territorio appenninico in emilia-romagna. si presentano, infatti, nei bacini del sillaro e gaiana evidenti fenomeni franosi attivi, ciò è dovuto soprattutto alla particolare conformazione geologica dei due bacini, condizionati dalla presenza di materiali come argille, argilliti, brecce argillose e marne (h in tab. i). 5. caratterizzazione granulometrica dei campioni di torbida fluviale nei campioni d'acqua relativi ai bacini del lavino, gaiana e sillaro si riscontra una omogeneità nella suddivisione dei solidi sospesi in classi granulometriche, con predominanza delle frazioni limosa ed argillosa (soprattutto quest'ultima), mentre nei solidi sospesi del savena si nota chiaramente, a parità di frazione limosa, la minor percentuale di aliquota argillosa e la maggior quantità di frazione sabbiosa, risultati che rispecchiano le caratteristiche geolitologiche specifiche dei quattro bacini (pavanelli et al., 2007; tab. iii). infine, grazie ai dati a disposizione può essere riscontrato un ulteriore nesso tra granulometria dei sedimenti, uso del suolo e trasporto torbido. come visto precedentemente, il bacino del savena si diversifica dagli altri bacini per la suddivisione granulometrica dei sedimenti: la minor percentuale di argilla riscontrata nei sedimenti può essere messa in relazione con l'uso del suolo del bacino che, di fatto, è interessato per il 40% della superficie da boschi di latifoglie (tab. ii), ovvero una composizione vegetale che meno lascia spazio a fenomeni erosivi superficiali di versante. di conseguenza, verificando la relazione che lega la granulometria dei sedimenti all'uso del suolo nel sillaro, la maggior percentuale di argilla ritrovata nei sedimenti è da collegare direttamente all'uso del suolo 174 rapti caputo et al. 175 tabella ii confronto tra classi di uso del suolo nei quattro bacini. comparison between different soil-use classes within the four basins composizione geochimica del solido sospeso ... del bacino dove due categorie particolarmente soggette ad erosione come affioramenti litoidi (calanchi) e terreno coltivato a seminativo, occupano la maggior parte della superficie. 6. composizione geochimica del solido sospeso l'elaborazione dei dati chimici relativi al materiale solido sospeso, campionato durante gli eventi di piena, riflette le lievi ma significative differenze composizionali fra i bacini idrografici distinte dall'analisi litologica e sedimentologica . le differenze emergono sia in termini di percentuale in peso degli elementi maggiori sia nella distribuzione degli elementi in tracce. per quanto riguarda gli elementi maggiori, dalla distribuzione dei dati nel diagramma cao vs al2o3 (fig. 4) possiamo individuare la presenza di tre gruppi di campioni: a) il primo gruppo rappresentato dai campioni provenienti dal torrente savena è caratterizzato da elevati valori di cao (13,5-15,5 wt%), e bassi valori di al2o3 (11-13,5 wt%) rispetto gli altri affluenti, che riflettono la prevalenza di rocce carbonatiche. infatti, il solido sospeso del savena, come risulta anche dalle analisi granulometriche (tab. iii), è caratterizzato dalla minore presenza di frazione argillosa rispetto quella degli altri bacini dove la concentrazione in al2o3 varia tra i 14 e 18 (wt%). b) il secondo gruppo, che comprende i campioni dei torrenti gaiana e lavino, è caratterizzato da elevate concentrazioni in al2o3 (1618 wt%) e basse in cao (6,5-9,5 wt%) e riflette la dominanza nel bacino idrografico di formazioni argillose. c) infine, concentrazioni intermedie tra questi due gruppi presentano i campioni del sillaro, caratterizzati anche da una forte variazione composizionale, che indica la presenza nel bacino idrografico sia di formazioni carbonatiche sia argillose. nei torrenti considerati, la buona correlazione tra cao (wt%) e al2o3 (wt%), legata ad una discreta omogeneità composizionale della componente silicatica è espressa dall'equazione: cao = -1,7 * (al2o3) + 37 con coefficiente di correlazione (r2) pari a 0,94. dal punto di vista geochimico, è possibile discriminare i torrenti anche dalla distribuzione sul diagramma k2o vs cao/al2o3 (fig. 4) e notare la suddivisione nei seguenti due gruppi. a) il solido sospeso nel torrente savena è caratterizzato da elevato rapporto cao/al2o3 (compreso tra 1 e 1,4) e da basse concentrazioni in k2o, con valore medio pari a 2 (wt%). inoltre, nel savena, il rapporto sodio vs silice è più alto rispetto gli altri affluenti (fig. 5); b) le concentrazioni in k2o nei torrenti gaiana e lavino sono significativamente elevate e presentano oscillazioni tra 2,7 e 3,2 (wt%), ed il rapporto cao/al2o3 assume un valore medio pari a 0,5. particolarmente basso è il rapporto sodio vs silice nei sedimenti del torrente sillaro (fig. 5) caratterizzato anche da bassi contenuti in potassio, probabilmente per la maggiore presenza nella frazione silicatica di minerali argillosi, a differenza del savena in cui una maggiore percentuale di silt e sabbie è costituita da feldspati e muscovite. 176 tabella iii descrizione statistica della classificazione granulometrica dei campioni di torbida fluviale. statistical description of the granulometric classification of the fluvial suspended load samples. rapti caputo et al. per quanto riguarda gli elementi in tracce, in tutti i campioni è stata osservata una buona correlazione positiva tra potassio vs rubidio e stronzio vs cao/al2o3 (fig. 5). gli elementi di transizione risultano leggermente arricchiti rispetto alla composizione media della crosta superficiale calcolata da taylor-mclennan (1985), arricchimento più evidente nel savena, e correlati positivamente con l'alluminio. infine, il torrente savena presenta caratteri geochimici peculiari anche per i bassi valori nella somma delle terre rare (ree) e per un maggior rapporto cr/al2o3 (fig. 5). 6.1 analisi statistica dei dati analitici l'analisi statistica dei dati analitici (tab. iv; fig. 6) ha messo in evidenza, nella stessa stazione di campionamento, la presenza di notevoli variazioni nel chimismo del solido sospeso delle acque fluviali; oscillazioni però che non sono sempre direttamente correlate con le variazioni di portata (fig. 8). infatti, pur mantenendo un'impronta geochimica caratteristica del bacino, i campioni mostrano fluttuazioni notevoli che probabilmente possono essere imputate sia ai diversi tempi di corrivazione dei sedimenti, nei differenti sottobacini fino alla stazione di prelievo, sia alle differenze nelle litologie affioranti nei singoli bacini e sottobacini idrografici ed al loro grado di erodibilità. tali parametri potrebbero spiegare, in una fase preliminare, le variabilità composizionali osservate nei campioni. per la determinazione dei valori di fondo naturali attuali è stata utilizzata l'analisi statistica univariata dei dati (de vi v o, 1995; le p e l t i e r c., 1969; si n c l a i r, 1976; tennant & white, 1959). nell'elaborazione statistica dei dati analitici acquisiti nella presente ricerca sono stati aggiunti anche i valori relativi al chimismo del materiale solido sospeso provenienti da amorosi et al. (2002) relativi al torrente sillaro (1 campione) e da rapti-caputo et al. (2005; 10 campioni relativi al savena; 5 al lavino e 1 al sillaro). in particolare, l'analisi di tutti i dati analitici (17: gaiana; 11:si llaro; 13 lavino; 15: savena) è stata realizzata in due fasi: in una prima fase, si è verificato il tipo di distribuzione dei dati relativi ad ogni singolo parametro (normale o log-normale) e se essa è rappresentativa di una o più popolazioni di dati. in una seconda fase, per ogni elemento, è stata individuata e rappresentata graficamente la distribuzio177 fig. 4 materiale solido sospeso: distribuzione geochimica dei dati sul diagramma cao vs al2o3 e k2o vs cao/al2o3 (concentrazioni in wt%). geochemical distribution of the suspended load data: cao versus al2o3 and k2o versus cao/al2o3 (concentrations in wt%). composizione geochimica del solido sospeso ... ne statistica dei dati analitici tramite l'utilizzo di istogrammi e di curve cumulative di frequenza (fig. 7). tale elaborazione statistica ha permesso, per ogni elemento, il calcolo delle soglie di anomalia (tab. iv). in particolare si può osservare che, in primo luogo, i valori del tenore di fondo attuale negli elementi maggiori non presentano significative variazioni. inoltre, per quanto riguarda gli elementi in tracce, di particolare interesse ambientale è l'elevato tenore di fondo in zolfo nel torrente savena (526ppm) e sillaro (451ppm) rispetto gli altri affluenti del reno. questi valori elevati riflettono la presenza della formazione gessoso-solfifera in tali bacini. il tenore di fondo in cr presenta valori più alti nel torrente gaiana (101 ppm) attribuiti alla maggior estensione delle formazioni ofiolitiche nel bacino idrografico. infine, il solido sospeso nel torrente savena è caratterizzato da elevati tenori di fondo attuale in celsio (43 ppm contro un valore medio circa a 4 ppm negli altri affluenti ) e bassi in rubidio (68 ppm) e zinco (59 ppm). 7. conclusioni l'analisi delle caratteristiche litologiche e dell'uso del suolo dei bacini idrografici dei torrenti di sillaro, gaiana, lavino e savena, affluenti del fiume reno, integrata con analisi granulometriche e chimiche del materiale solido sospeso hanno permesso di determinare la composizione geochimica dei sedimenti di tali affluenti, verificando durante gli eventi di piena una buona qualità ambientale della componente inorganica trasportata (confronto con d.m. 471/99). l'impronta geochimica del solido sospeso fluviale risulta fortemente condizionata dalle differenze delle litologie affioranti nei bacini e dai caratteri geomorfologici (es. acclività) per cui è possibile definire uno stretto intervallo di variazioni composizionali nei sedimenti trasportati che possono essere tradotte in impronta geochimica dei corrispondenti bacini. il solido sospeso del torrente savena rispetto gli altri affluenti indagati risulta arricchito in zolfo, in accor178 fig. 5 materiale solido sospeso: distribuzione dei dati analitici sul diagramma na2o vs sio2; sr vs cao/al2o3; cr vs al2o3 e delle terre rare (ree) nei quattro affluenti. distribution of the suspended load data: na2o versus sio2; sr versus cao/al2o3; cr vs al2o3 and of the rare earths (ree) for the four river branches. rapti caputo et al. 179composizione geochimica del solido sospeso ... fig. 6 variazioni nel chimismo del solido sospeso (concentrazioni in ppm). chemical variations in the suspended load (concentraions in ppm) do con la presenza della formazione gessoso-solfifera. inoltre, la maggior presenza della frazione sabbiosa si riflette nel maggior contenuto in elementi alcalini. l'analisi statistica dei dati ha permesso la definizione dei tenori di fondo attuali per ogni elemento chimico. tali valori, che costituiscono l'impronta geochimica di ogni bacino, permettono di riconoscere l’eventuale presenza di fenomeni di contaminazione naturale e/o antropica. infine, meno significative sono le variazioni delle concentrazioni in elementi di transizione nonostante che, nel torrente gaiana si è stimato un tenore di fondo in cromo (101 ppm) leggermente più alto attribuito alla maggior estensione di rocce ofiolitiche affioranti. ringraziamenti gli autori ringraziano il dott. e. tassinari del dipartimento di scienze della terra dell'università di ferrara, per il supporto analitico. 180 rapti caputo et al. tabella iv materiale solido sospeso: stima dei tenori di fondo attual i delle grandezze geochimiche analizzate. suspended load sediments: estimate of the present-day background values of the analysed geochemical parameters. fig. 7 esempio dell'elaborazione statistica dei dati geochimica relativi al torrente gaiana a) curva di frequenza cumulativa (y: asse di probabilità); b) diagramma di frequenza . example of statistical elaboration of the geochemical data relative to the gaiana torrent. a) cumulative frequency; b) frequency distribution. 181 riferimenti bibliografici amorosi a. centineo m.c., dinelli e. lucchini f. & teteo f (2002) geochemical and mineralogical variations as indicators of provenance changes in late quaternary deposits of se po plain sedimentary geology, 151: 273-292. ba r t o l i n i c., ca p u t o r. & pi e r i m (1996) p l i o c e n e quaternary sedimentation in the northern apennine foredeep and related denudation. geol. mag. 133, 255-273. bueselinck l., govers g., steegen a.& poesen v. (2000) impact of soil aggregates on the size selectivity of the sediment deposition process, in the role of erosion and sediment transport in nutrient and contaminant transfer iahs, waterloo, canada, pp. 99-107. de vi v o b. (1995) elementi e metodi di geochimica ambientale liguori editore, napoli. dr o p p o i.g., le p p a r d g.g., fl a n n i g a n d.t. & li s s s . n . (1997) the freshwater floc: a functional relationship of water and organic and inorganic floc constituents affecting suspended sediment properties water, air and soil pollution, 99 (1-4), fig. 8 torrente gaiana: a) dispersione della composizione chimica del materiale solido sospeso (concentrazioni espresse in wt%) rispetto agli eventi di piena (portata espressa in m3/s); b) sio2 (wt%) vs portata (q, m3/s) gaiana torrent: a) distribution of the chemical composition of the suspended load (concentrations in wt%) during the major flooding events (water discharge in m3/s); b) sio2 (wt%) versus water discharge (q, m3/s). composizione geochimica del solido sospeso ... 182 ms. ricevuto il 28 febbraio 2008 testo definitivo ricevuto il 30 maggio 2008 ms. received: february 28, 2008 final text received:may 30, 2008 rapti caputo et al. 43-54. franzini m., leoni l., & saitta m. (1975) revisione di una metodologia analitica per fluorescenza x basata sulla correzione completa degli effetti di matrice. rend soc. it. min. petrol., 2: 497-510. horowitz a.j. (1991) a primer on sediment trace-element chemistry lewis, michigan, usa. lepeltier c. (1969) a simplified statistical treatment of geochemical data by graphical representation econ. geol., 64: 538-550. ongley e.d., krishnappan b.g., droppo i.g., rao s.s. & ma g u i r e r.j. (1992) cohesive sediment transport: emerging issues for toxic chemical management hydrobiologia, 235/236: 177-187. pavanelli d. & bigi a. (2004) indirect analysis methods to estimate suspended sediment concentration: reliability and relationship of turbidity and settleable solids biosystems engineering, 90 (1): 75-83. pavanelli d. & bigi a. (2005a) suspended sediment transport monitoring in the reno basin: relationship between hydrological parameters and discharges, aiia 2005 “l'ingegneria agraria per lo sviluppo sostenibile dell'area mediterranea” catania 27-30 giugno 2005. pavanelli d. & bigi a. (2005b) a new indirect method to estimate suspended sediment concentration in a river monitoring programme, biosystems engineering 2005, 92 (4), 513-520. pa v a n e l l i d. & pa g l i a r a n i a. (2002) monitoring water flow, turbidity and suspended sediment load, from an apennine catchment basin, italy biosystems engineering, 83/4: 463-468. pa v a n e l l i d., pa g l i a r a n i a. & bi g i a. (2004) rilevamento idrologico e dei solidi sospesi nelle stazioni sperimentali dei torrenti sillaro, lavino, savena, e foce reno, 2° giornata di studio “monitoraggio fluviale ed erosione nella pianificazione e gestione dei bacini appenninici” 8 ottobre 2004, aula magna della facoltà di agraria, bologna, via g. fanin, 50, atti pubblicati su rivista dell'arpa, n. 6. pavanelli d. & rigotti m. (2007) relationship between suspended sediment concentration and total nitrogen, and comparison among basins for some apennine rivers atti del convegno internazionale “cost634” del 1-3 ottobre 2007, praga “off-site impacts of soil erosion and sediment transport. pa v a n e l l i d., ta g l i o l i g. & pa g l i a r a n i a. (2001) rilevamento delle portate e del trasporto torbido nelle stazioni sperimentali del torrente sillaro e torrente lavino. analisi dei dati 1997-2000 convegno ”monitoraggio fluviale ed erosione nella pianificazione e gestione dei bacini appenninici” organizzato da pavanelli d., 6 luglio 2001, fac. agraria, bologna, stampato a cura dell'autorità di bacino del reno, bologna, (pp. 162). rapti-caputo d., tassinari r., vaccaro c. & pavanelli d. (2005) caratterizzazione geochimica dei sedimenti e delle acque del fiume reno a r p a rivista, gen-feb 2005, 1: 27-29. ru s s e l l ma, wa l l i n g de & ho d g k i n s o n ra (2001) suspended sediment sources in two small lowland agricultural catchments in the uk journal of hydrology 252: 1-24. sinclair a. j. (1976) application of probability graphs in mineral exploration aeg sp. vol. 4, toronto. ta y l o r sr & mcle n n a n sm. (1985) the continental crust, its composition and evolution: an examination of the geochemical record preserved in sedimentary rocks blackwell scientific publications, oxford (oxfordshire). tennant c. b. & white m. l. (1959) study of the distribution of some geochemical data econ. geol., 54: 1281-1290. wa l l i n g d.e., we b b b.w. & wo o d w a r d j.c. (1992) some sampling considerations in the design of effective strategies for monitoring sediment-associated transportin erosion and sediment transport monitoring programmes in river basins, edited by j. bogen, walling d.e., day, t.j., pp. 279288, iahs, oslo. evoluzione altitudinale spazio-temporale degli alberi durante gli ultimi 12000 anni in valle d’aosta (italia) elisabetta brugiapaglia dipartimento scienze animali, vegetali e dell’ambiente facoltà di agraria università degli studi del molise via de sanctis 86100 campobasso riassunto: e. brugiapaglia, evoluzione altitudinale spazio-temporale degli alberi durante gli ultimi 12000 anni in valle d’aosta (italia). (it issn 0394-3356, 2007). sono stati analizzati quattro siti della valle d’aosta orientale che attualmente si trovano uno nel bosco denso e tre nella treeline (la torbiera di pilaz, 1900 m a.s.l., la torbiera di champlong, 2320 m a.s.l., il lago di champlong, 2300 m a.s.l. e la torbiera di sant’anna, 2304 m a.s.l.). dai risultati ottenuti attraverso l’analisi pollinica, dei macroresti e 14 datazioni ams, si evince che nel periodo antecedente 12000 bp nei siti analizzati era presente solo una vegetazione erbacea e gli alberi non raggiungevano i 1900 m d’altitudine, quindi si può ritenere che il limite degli alberi sia stato almeno 400 m più basso dell’attuale. tra 12000 e 10700 bp a 1900 m dovevano vegetare solo rari esemplari di betula e larix, mentre ad altitudini inferiori cominciava ad aumentare pinus ed il limite superiore degli alberi doveva aggirarsi intorno ai 1900 m. tra 10700 e 10000 bp a 2300 m dovevano essere presenti individui isolati di larix e betula, mentre a 1900 m c’erano radi esemplari di betula. aumentano i taxa erbacei. tra 10000 e 9000 bp sia a 2300 m che a 1900 m la vegetazione era costituita da formazioni rade a betula e larix. tra 9000 e 8000 bp a 1900 m era presente un bosco chiuso a larix e betula mentre a 2300 m c’era un bosco rado con pinus cembra, pinus sylvestris e larix; a sant’anna sempre a 2300 m d’altitudine, ma in val di gressoney, larix era dominante. il limite degli alberi era più alto di circa 200 m rispetto all’attuale. tra 8000 e 5000 bp a 1900 m era presente un bosco misto a larix, abies e pinus cembra; a pilaz, in cui dominava larix, si creò una zona di contatto tra le formazioni subalpine inferiori con abies e quelle subalpine superiori con pinus cembra. a 2300 m a champlong c’era un bosco rado a betula e pinus cembra che venne sostituito nella fase più arida da larix che era la specie dominante a sant’anna. tra 5000 e 2500 bp a 1900 m c’erano radi larix e abies mentre a 2300 m erano presenti alcuni pini ed a sant’anna una formazione aperta e rada a larix e pinus cembra. il limite degli alberi in questo intervallo di tempo si abbassò di circa 200-300 m. per il periodo più recente (> di 2500 bp), a 1900 m, la vegetazione era caratterizzata da larice e abete rosso; a 2300 m vegetavano radi pini cembri ed a sant’anna larici sparsi. il limite degli alberi risulta influenzato anche dalle attività antropiche che diventano rilevanti sull’area indagata come dimostra la presenza di un villaggio attribuito all’età del bronzo e di taxa legati al pascolo ed all’agricoltura. abstract: e. brugiapaglia, altitudinal evolution in space and time of trees during the past 12000 years in aosta valley (italy). (it issn 0394-3356, 2007). four sites have been analized, one in a closed forest and three above today’s treeline (pilaz peat bog at 1900 m a.s.l., champlong peat bog at 2320 m a.s.l., champlong lake at 2300 m a.s.l., and sant’anna peat bog at 2304 m a.s.l.) in the eastern aosta valley. the results obtained by pollen, macrofossil data, and 14 radiocarbon dating by ams, suggest that for periods older than 12000 bp in the analized sites there was just a herbaceous species and the trees did not reach 1900 m in altitude. treelimit was at least 400 m lower than today. between 12000 and 10700 bp at 1900 m there were rare betula and larix. at lower altitudes pinus increased and the upper treeline was about 1900 m. between 10700 and 10000 bp, at 2300 m there were isolated larix and betula, whereas at 1900 m there was isolated betula. this period is characterized by increasing values of herbaceous species-pollen. between 10000 and 9000 bp at both 2300 m and 1900 m the vegetation made up of betula and larix was sparse. between 9000 and 8000 bp at 1900 m there was a closed forest of larix and betula, at 2300 m there was an open forest of pinus cembra, pinus sylvestris and larix, whereas at sant’anna at 2300 m in gressoney valley, larix dominated. the treeline was about 200 m higher than today. between 8000 and 5000 bp at 1900 m there was a forest with larix, abies and pinus cembra; pilaz, where larix dominated, was a contact area between lower subalpine vegetation of abies and upper subalpine vegetation of pinus cembra. at 2300 m, in champlong, there was an open forest of betula and pinus cembra which was replaced by larix in drier periods. larix was dominating in sant’anna. between 5000 and 2500 bp at 1900 m there were sparse trees of larix and abies, whereas at 2300 m there were sparse trees of pinus, and in sant’anna there were sparse larix and pinus cembra. the treeline lowered by about 200-300 m. for the latest period (after 2500 bp) at 1900 m the vegetation was characterized by larix and picea, at 2300 m by sparse pinus cembra and in sant’anna by larch. the treeline was influenzed by human activity which was considerable, as shown by the presence of a village of the bronze age, and the grazing and agricoltural taxa. parole chiave: tardoglaciale, olocene, limite degli alberi, valle d’aosta, italia. keywords: late glacial, holocene, tree line, aosta valley, italy. il quaternario italian journal of quaternary sciences 20(2), 2007 195-212 1. introduzione l’ecotono subalpino-alpino è particolarmente sensibile ai cambiamenti climatici come lo dimostra la fisionomia della vegetazione che cambia passando da zone arboree a quelle arbustive ed infine alle praterie alpine: la risposta della vegetazione alle variazioni climatiche è più pronunciata nelle zone di altitudine e nell’ecotono timberline e treeline (wick, 2000; tinner & theurillat, 2003) in quanto nelle aree montane i segnali climatici risultano amplificati (beniston et al., 1997). la distribuzione spaziale degli alberi e la loro densità è influenzata dalla temperatura, dalla copertura nevosa, dai movimenti dei ghiacciai più o meno vicini e dall’azione antropica. il ruolo di ciascun fattore è difficile da stabilire, ma l’analisi pollinica ha sempre cercato di contribuire a queste ricerche: infatti in situazioni stazionali favorevoli, 196 e. brugiapaglia la composizione pollinica dei sedimenti può precisare il carattere glaciale o periglaciale di un’area (brugiapaglia & barbero, 1994) ed allo stesso modo la vegetazione forestale che caratterizza le altitudini inferiori, può fornire elementi indiretti di datazione. tuttavia l’interpretazione dei diagrammi pollinici provenienti da siti d’altitudine è resa difficile dalle anomalie della rappresentazione pollinica di alcune specie (esagerata per pinus, ridotta per larix) e dal trasporto ascendente del polline che rende impossibile la precisa ricostruzione della struttura della vegetazione locale; molti segnali sono ambigui ed in particolare la diminuzione del rapporto pa/t (polline arboreo/totale) può essere indice dell’avanzata del ghiacciaio, le attività pascolive oppure l’evoluzione dell’ambiente di sedimentazione (passaggio dal lago alla torbiera) possono influenzare l’interpretazione del diagramma. alcuni di questi limiti possono essere superati o quanto meno ridotti, utilizzando le concentrazioni assolute e i macroresti vegetali, così come applicato da ammann & wick (1993), tinner et al. (1996), tinner & theurillat (2003), birks (2003) e birks & birks (2000) ed inoltre analizzando siti localizzati sullo stesso versante e su piani altitudinali diversi (david, 1993a; david et al., 2006). la ricerca presentata vuole evidenziare le specie arboree che hanno avuto un ruolo sui siti d’altitudine considerando la loro migrazione regionale e locale, nonché i fattori biotici e abiotici che hanno avvantaggiato o svantaggiato alcune specie rispetto ad altre. 2. area di studio 2.1. descrizione dei siti l’analisi del limite superiore degli alberi e della loro evoluzione spaziale e temporale in valle d’aosta si basa sull’interpretazione dei diagrammi ottenuti dalla torbiera di pilaz, dal lago e dalla torbiera di champlong, e dalla torbiera di sant’anna (fig. 1). da un punto di vista geologico, tutti i siti sono compresi nel cosiddetto “complesso piemontese dei calcescisti con ofioliti” che comprende rocce vulcaniche risalenti al triassico e giurassico, in particolare serpentine, serpentino-scisti, prasiniti e anfiboliti. 2.1.1. torbiera di pilaz la torbiera di pilaz (45°49’01”n, 17°17’10”e) è situata in valletournenche a 1900 m d’altitudine (fig. 1b). si tratta di una torbiera a sfagni localizzata nella parte terminale di un lago poco profondo la cui superficie è colonizzata da ranunculus aquatilis, circondata da un bosco a larix decidua con qualche picea excelsa ed un orlo a calluna vulgaris. la torbiera si sviluppa dietro una morena tardoglaciale ed è circondata da altre morene anch’esse risalenti al tardoglaciale. 2.1.2. lago di champlong i l piccolo lago di champlong (45°49’30”n, 17°15’35”e) è situato in valletournenche a 2300 m d’altitudine (fig. 1b) su un altopiano ai piedi di una ripida falesia sulla riva sinistra del torrente marmore: sulla sua superficie sono presenti alcuni isolotti di sfagno galleggiante a contatto con la vegetazione a carex sp. e phragmites australis, mentre la vegetazione arbustiva è dominata da rhododendron ferrugineum e juniperus nana. alcuni rari larici colonizzano il versante nord del monte tantanè fino all’altitudine di 2500-2600 m compreso un esemplare di picea abies di circa 1 m di altezza che è stato osservato sulla falesia che circonda il lago. 2.1.3. torbiera di champlong la torbiera di champlong (45°49’15”n, 17°15’37”e) è situata in valletournenche a 2320 m d’altitudine, tra due morene tardoglaciali ed è circondata da “rock glacier” inattivi (fig. 1b). si tratta di una torbiera a sfagni nelle cui zone ancora in acqua, sono visibili dei tronchi identificati come pinus cembra type. attualmente questa specie è completamente assente dalla vegetazione forestale che è invece dominata da larix decidua, mentre tra le specie arbustive si rilevano salix hastata, rhododendron ferrugineum e juniperus nana. dal punto di vista climatico i tre siti sopra illustrati, ricadono in una area a evidente aridità con precipitazioni medie di 800 mm annui e temperatura media annua di 6,3° c (mercalli et al., 2003). 2.1.4. torbiera di sant’anna la torbiera di sant’anna (45°51’30”n, 17°06’25”e), localizzata in val di gressoney a 2304 m d’altitudine, si trova sulla riva destra del torrente lys di fronte al gran ghiacciaio del lys (fig. 1a). durante la piccola età glaciale il ghiacciaio scendeva fino a 1990 m d’altitudine. successivamente è andato incontro ad una serie di oscillazioni ed è attualmente in fase di ritiro. i lavori per la costruzione di un impianto di risalita, hanno portato alla luce numerosi resti di alberi, di cui non è stato possibile stabilire la posizione stratigrafica. dai sondaggi realizzati per valutare la profondità della torbiera, si è evidenziato un deposito massimo di 145 cm. nelle aree sufficientemente umide la vegetazione è costituita da praterie con sfagni mentre i versanti del monte bettaforca, che circondano la torbiera, sono colonizzati da rari larix, mentre più in basso si rinvengono arbusti di alnus viridis e picea abies. dal punto di vista climatico sant’anna è compresa in una zona a maggiore piovosità rispetto ai siti di cui sopra: infatti le precipitazioni sono di 994 mm annui e temperatura media annua di 3,8° c (mercalli et al., 2003). in generale, i siti considerati sono attualmente privi di vegetazione arborea densa, tranne la torbiera di pilaz che è immersa in un bosco di larice mentre i restanti sono caratterizzati solo da qualche raro larix decidua che raggiunge l’altitudine di 2500-2600 m. la fascia degli alberi nani e arbusti è caratterizzata da rhododendron ferrugineum, juniperus nana, salix hastata, salix helvetica, alnus viridis e picea abies allo stato arbustivo. 3. materiali e metodi i sedimenti per l’analisi pollinica e per quella dei macroresti sono stati prelevati con il carottiere russo dal diametro di 6 cm. a pilaz è stata prelevata una carota che ha raggiunto la profondità di 300 cm, alla torbiera di champlong è stata prelevata una carota di 595 cm, al lago di champlong una di 310 cm in cui i primi 190 cm rappresentano la profondità dell’acqua ed infine alla torbiera di sant’anna è stata prelevata una carota di 145 cm. per ogni sito sono stati effettuati due carotaggi paralleli, uno da utilizzare per la descrizione stratigrafica e l’analisi pollinica, l’altro per l’analisi dei macroresti e le datazioni. 197evoluzione altitudinale spazio-temporale ... l’estrazione dei pollini dai sedimenti è stata eseguita secondo la metodica classica dell’acetolisi per le torbe (ertdman, 1936) mentre per le argille è stato utilizzato il liquido di thoulet (goeury & beaulieu, 1979). l’identificazione pollinica è stata effettuata con un microscopio a ingrandimento x 400 e x 1000. sono stati utilizzati inoltre gli atlanti fotografici di reille (1992, 1995) e la palinoteca del laboratorie de botanique historique et palynologie. fig. 1 area di studio in: a) val di gressoney (torbiera di sant’anna) e b) in valletournenche [torbiera di pilaz, lago (1) e torbiera (2) di champlong]. the study area is located in: a) gressoney valley (peat bog of sant’anna) and b) in valletournenche [peat bog of pilaz, lake (1) and peat bog (2) of champlong]. 198 la somma pollinica di ogni campione è compresa tra 300 e 800 pollini. nel calcolo delle percentuali il polline delle piante acquatiche, delle pteridophytae, delle cyperaceae e delle indeterminate è stato escluso dalla somma totale (ap – arboreal pollen e nap – non arboreal pollen = 100%); le concentrazioni sono state calcolate con il metodo volumetrico. l’estrazione dei macroresti vegetali è stata effettuata su quantitativi costanti di 200 cc di sedimento; lo stesso è stato lavato con acqua ed è stato setacciato su maglie di 500, 250 e 180 µm. i macrofossili sono stati identificati usando uno stereoscopio da 10 a 40 ingrandimenti, utilizzando la collezione di riferimento e gli atlanti fotografici (berggren, 1969, 1981; anderberg, 1994). la determinazione dei legni è stata effettuata utilizzando le chiavi di determinazione di jacquiot (1955), schweingruber (1990a, 1990b). l’analisi dei macroresti che è stata realizzata è solo di tipo qualitativo. i risultati dell’analisi pollinica e dei macrofossili, sono rappresentati con il programma gpalwin (goeury, 1997) ed i diagrammi sono suddivisi in biozone con composizione floristica omogenea (paz). sono state effettuate 14 datazioni assolute su resti vegetali (aghi, legno, carboni, semi) e due su campioni di torba con il metodo dell’ams (accelerator mass spectrometry) all’università di tuxon in arizona (tab. 1). 4. risultati e interpretazione la stratigrafia dettagliata di ogni singolo carotaggio, è riportata alla sinistra del diagramma nonché le datazioni ams in bp non calibrate. nei 4 diagrammi (fig. 2, 3, 4, 5) sono stati riconosciuti 100 tipi pollinici, 23 tipologie di macrofossili e sono stati analizzati 328 campioni. le correlazioni tra i diagrammi sono basate sulle cronologie individuate attraverso le datazioni e le analogie della composizione floristica (tab. 3). il diagramma della torbiera di pilaz (fig. 2), situata a 1900 m s.l.d.m., sulla base delle datazioni, evidenzia gli eventi vegetali a partire da circa 12.000 bp. e’ stato suddiviso in 11 biozone e sono state effettuate 7 datazione assolute (tab. 1). nella biozona p1 (300-271 cm) il sedimento è composto da argilla ed è caratterizzato dalla presenza di basse percentuali dei taxa arborei (inferiori al 20%), da percentuali elevate di artemisia, chenopodiaceae, apiaceae e caryophyllaceae. le concentrazioni sono estremamente basse per i taxa arborei (in media 4,1x102 p/g), nonchè per artemisia che ha in media 8,6x102 p/g. in questa paz sono stati individuati e determinati i macroresti riportati nella tabella 2; in particolare è da ri levare la presenza di semi di ranunculaceae acquatiche e qualche raro resto di larix e betula. sono state effettuate due datazioni che hanno avuto come risultato rispettivamente 9630±145 bp e 11860±110 bp; la prima delle due datazioni è stata rifiutata perché apparentemente in contrasto con la composizione floristica della zona pollinica, ma soprattutto perché anteriore alle tre datazioni effettuate nei livelli superiori. il passaggio alla paz p2 (271-265 cm) è determinato dal cambio repentino della sedimentazione da argilla a gyttja e dall’aumento delle frequenze del polline di ranunculaceae acquatiche (fino a 40 %). questa paz è caratterizzata dall’aumento delle concentabella 1 materiale datato e risultati ottenuti. * calibration program rev.3.0.2 (stuiver & reimer, 1993). dated materials and obtained results. * calibration program rev.3.0.2 (stuiver & reimer, 1993). località profondità materiale datato età bp non età calendario rif. in cm calibrata calibrata (2σ)* torbiera di pilaz 50-60 aghi di larix 255±55 1480-1955 ad aa15112 110-115 legno di pinus tp. cembra 7865±75 7000-6480 bc aa15111 210-215 semi 9570±80 9000-8460 bc aa15113 227-232 legno indeterminato 9985±95 9744-9382 bc aa23426 240-245 semi di biscutella 10790±100 10925-10731 bc aa23427 273-276 aghi di larix 11860±110 12000-11658 bc aa23429 285-290 aghi di larix 9630±145 9059-8352 bc aa17808 torbiera di champlong 215-220 legno di pinus tp. cembra 8110±75 7310-6720 bc aa15106 260-265 carboni indeterminati 9030±95 8340-7900 bc aa15105 lago di champlong 305-310 legno di pinus 3805±70 2460-2040 bc aa15110 torbiera di santa anna 45-50 torba 1850±55 64-330 ad a8227 70-75 torba 2900±75 1308-864 bc a8226 110-115 legno di salix 6770±120 5840-5441 bc a8225 135-140 legno di salix 9170±215 8916-7709 bc a8224 e. brugiapaglia 199 trazioni di juniperus (3,9x102 p/g), betula (15x102 p/g), pinus (40x102 p/g), poaceae (12x102 p/g) e artemisia (29x102 p/g). aumentano anche le percentuali di juniperus, betula e pinus, rimangono costanti quelle delle poaceae ed invece diminuiscono quelle di artemisia e degli altri taxa steppici. il passaggio alla biozona p3 (265-240 cm) è caratterizzato dall’aumento delle percentuali e delle concentrazioni di pinus (35x103 p/g), la riduzione di artemisia, betula, juniperus, ranunculaceae acquatiche ed inizia invece una fase a cyperaceae. la presenza di semi di specie acquatiche (hippuris, eleocharis, ranunculaceae acquatiche) testimonia di un ambiente lacustrepalustre circondato tuttavia da un sistema di vegetazione arborea con larix e betula di cui sono presenti i macroresti. nonostante le elevate percentuali (65%) e concentrazioni del polline di pinus, non sono stati osservati i suoi macroresti; i valori massimi di pinus sono di poco antecedenti a 10790±100 bp. segue la biozona p4 (240-230 cm) con una drastica riduzione delle concentrazioni di pinus (16x103 p/g), un moderato aumento delle concentrazioni di artemisia (3,6x103 p/g) e poaceae (5,4x103 p/g), con la riduzione ulteriore del polline di ranunculaceae acquatiche. sono stati osservati semi di hippuris, ranunculaceae acquatiche, caryophyllaceae, eleocharis, frutti e legno di betula. questa zona è stata datata 9985±95 bp. nella biozona p5 (230-210 cm) si verifica il cambio di sedimentazione passando da gyttja a torba; aumentano le percentuali di betula e di pinus, la curva di larix diventa continua e scompare definitivamente il polline delle ranunculaceae acquatiche. nella parte basale di questa biozona sono stati osservati i semi di hippuris vulgaris, carex, ranunculaceae acquatiche, fig. 2 diagramma pollinico semplificato della torbiera di pilaz. il quadrato indica la presenza di macroresti. pollen percentage diagram from pilaz peat bog including major taxa. the square shows macroremains. evoluzione altitudinale spazio-temporale ... 200 tabella 2 macroresti rinvenuti. macroremains found. località profondità macroresti rinvenuti torbiera di pilaz 40-45 semi di viola sp. 55 aghi di larix 75 legno indeterminabile 85 legno indeterminabile 90-95 aghi di larix, legno di pinus tp.cembra e abies alba, legno indeterminabile, semi di carex 105 legno indeterminabile 110 legno di pinus tp. cembra e abies alba 120-125 aghi di larix, semi di carex 147 legno di conifera 151 legno di larix/picea 170-175 aghi di larix, frutti di betula cfr. pendula, semi di carex 195-200 frutti di betula, legno di salix, semi di larix, semi di carex rostrata 205 legno indeterminabile 210-212 semi di ranunculus acquatico 220-225 aghi di larix, frutti di betula, semi di hippuris vulgaris, semi di carex, semi di ranunculus acquatico, semi di eleocharis, semi di potamogeton natans, semi di sparganium sp. 230-235 legno di betula, frutti di betula, semi di hippuris, semi di ranunculus acquatico, semi di caryophyllaceae, semi di eleocharis 245-250 aghi di larix, semi di ranunculus acquatico, semi di hippuris vulgaris, semi di eleocharis, legno indeterminabile 260-265 frutti di betula, semi di ranunculus acquatico, semi di viola, semi di biscutella, semi di eleocharis 265-268 aghi di larix, semi di ranunculus acquatico 270-271 semi di ranunculus acquatico 280-283 aghi di larix, semi di ranunculus acquatico 285-290 aghi di larix, frutti di betula, semi di ranunculus acquatico 293-296 legno di larix/picea e aghi di larix lago di champlong 280-290 legno di pinus tp. cembra 305 legno di pinus indeterminabile e aghi torbiera di champlong 60 legno di salix 80 legno di salix 135 legno di larix/picea 150-160 aghi di larix, frutti di betula pubescens cfr., semi di carex 170 legno di salix 190 legno di betula 196 legno di pinus tp. cembra 200 legno di betula 215-217 legno di betula, legno di pinus tp. cembra, pinus tp. sylvestris, salix sp., frutto di pinus cembra, aghi indeterminabili. 220 legno di pinus tp. cembra 225 legno di pinus tp. cembra 232 legno di pinus tp. cembra 235 legno di larix/picea 245 legno di larix/picea 275-285 megaspore di selaginella selaginoides 305-315 semi di carex 390-400 aghi di larix, semi di carex 410-420 resti vegetali indeterminabili 435-445 semi di saxifraga sp. 450 tracheide di betula torbiera di santa anna 110-115 legno di salix 135-140 legno di salix ? legno di larix/picea e pinus tp. cembra e. brugiapaglia eleocharis sp., potamogeton natans, sparganium sp., aghi di larix e frutti di betula. la biozona p6 (210-195 cm) è stata individuata per il picco di polline di taxa erbacei, in particolare si osserva un aumento delle percentuali di cyperaceae, pteridium tp., campanulaceae, scrophulariaceae, trifolium tp., lathyrus tp., apiaceae e cichorioideae. i macroresti osservati sono: frutti di betula, semi di larix e carex rostrata e legno di salix. nessuna data è stata realizzata per questa biozona, ma l’interpolazione permette di attribuirla ad un periodo compreso tra 9400 e 9100 bp. la biozona successiva p7 (195-115 cm) è estremamente omogenea sia dal punto di vista floristico che stratigrafico. e’ caratterizzata dalla presenza dei macroresti e percentuali superiori al 5% di larix. le elevate concentrazioni (24x103 p/g) e percentuali di pinus non sono supportate dal ritrovamento dei suoi macroresti, mentre sono presenti solo semi di carex e frutti di betula. la biozona p8 (115-100 cm) è stata individuata in corrispondenza della diffusione del polline di abies alba datata 7865±75 bp ed individua un picco nelle percentuali (42%) e concentrazioni (12x104 p/g) di betula. sono presenti i resti legnosi di pinus tp. cembra e abies alba. la biozona p9 (100-70 cm) è caratterizzata da una ridotta presenza del polline di larix, di cui sono presenti i macroresti (aghi), da una fase dominata da abies di cui è osservato l’aumento delle percentuali e delle concentrazioni (19,5x103 p/g), nonchè la loro rapida riduzione. compaiono i l poll ine di juglans e castanea. in questa biozona sono stati inoltre osservati alcuni resti legnosi, ma il loro pessimo stato di conservazione ne ha impedito la determinazione. si verifica la brusca riduzione delle cyperaceae a cui si contrappone un aumento del polline dei taxa erbacei in particolare cichorioideae e campanulaceae. la biozona p10 (70-40 cm), datata alla base 255±55 bp, è stata individuata in corrispondenza della riduzione delle concentrazioni (1,5x103 p/g) e delle percentuali di abies e dell’inizio della curva continua di picea e fagus. gli ultimi macroresti osservati appartengono a larix le cui percentuali variano da > 1% a 2%. e’ una biozona con ericaceae di cui è ben nota la scarsa produzione di polline ed il loro scarso trasporto. nella biozona p11 (40-10 cm) non sono stati osservati resti di taxa arborei ed erbacei. e’ da rilevare la presenza del polline delle ericaceae (7%), rosaceae, plantago tp. alpina, rumex, cichorioideae, cyperaceae e selaginella. alla torbiera di champlong, (fig. 3) la cht1 (595-560 cm) è dominata da erbacee steppiche, in prevalenza artemisia (12,2x102 p/g). e’ da notare la presenza del polline di pinus (5,2x102 p/g), betula, juniperus ed ericaceae, ma in questa biozona non sono stati ritrovati macroresti vegetali. la cht2 (560-435 cm) corrisponde all’aumento delle concentrazioni di pinus (11,7x103 p/g), poaceae (5,7x102 p/g) e artemisia (2,4x103 p/g); aumenta la percentuale di pinus, quella di artemisia diminuisce, mentre le poaceae restano costanti. sono sempre presenti betula e juniperus anche se le frequenze diminuiscono e diventano inferiori a 1%. in queste due paz sono presenti in modo continuo anche salix e alnus viridis. nella parte superiore della cht 2 sono stati rinvenuti semi di saxifraga sp. e una tracheide di betula. nella cht3 (435-260 cm) si assiste alla riduzione delle concentrazioni di tutti i taxa (arborei: 2,3x103 p/g; erbacei: 1,6x103 p/g). la parte superiore della paz è stata datata 9030±95 bp. sono stati rinvenuti i seguenti macroresti: megaspore di selaginella selaginoides, semi di carex, aghi di larix e resti vegetali indeterminabili. a partire dalla cht4 (260-235 cm) aumentano le frequenze e le concentrazioni dei taxa arborei (20,5x103 p/g), in particolare pinus (18,4x103 p/g), betula (5,7x102 p/g) e larix (7,1x102 p/g), mentre si riducono drasticamente le percentuali dei taxa erbacei. per quel che riguarda i macroresti in ordine di apparizione troviamo i legni di larix e successivamente quelli di pinus cembra; quest’ultimo taxon marca l’inizio della cht5 (235-220 cm) che è quindi caratterizzata dalla diffusione di pinus cembra e dalle concentrazioni elevate di pinus (34,3x103 p/g). la parte finale della paz è stata datata 8110±75 bp da cui si deduce che in questo settore della valle d’aosta la diffusione di pinus cembra è iniziata a circa 8400 bp. i macroresti rinvenuti sono stati identificati come legni di pinus cembra, di betula, di pinus tp. sylvestris, di salix sp. e un frutto di pinus cembra. cht6 (220-170 cm) corrisponde all’inizio della curva continua di abies registrata a partire da 8110 bp, dalla presenza di larix benchè le sue percentuali e concentrazioni diminuiscano (2,1x102 p/g). aumentano le percentuali e le concentrazioni di betula (2,3x103 p/g) e di pinus cembra (6x102 p/g), mentre inizia la progressiva riduzione delle concentrazioni di pinus (17,6x103 p/g). a livello stazionale è evidente un aumento delle percentuali di cyperaceae. tra le specie arbustive è anche da rilevare la presenza quasi continua del polline delle ericaceae. i macroresti rinvenuti sono legni appartenenti a betula, pinus tp. cembra e salix. la cht7 (170-145 cm) è stata individuata per l’elevata percentuale di cyperaceae, per le concentrazioni di pinus (1,3x103 p/g ) che diminuiscono bruscamente, anche se le percentuali non hanno lo stesso andamento e rimangono su valori elevati (70%) e per la diminuzione delle concentrazioni di pinus cembra (1,3x102 p/g). e’ da rilevare inoltre la presenza di due picchi di juniperus a 160 e 145 cm di profondità. a 160 cm di profondità si assiste anche al cambio di sedimentazione passando da gyttja a torba. i macroresti rinvenuti sono in particolare semi di carex, aghi di larix e frutti di betula pubescens cfr. la cht8 (145-35 cm) è caratterizzata dalla riduzione delle cyperaceae, dall’aumento delle poaceae; la vegetazione arborea rimane su valori pressochè costanti, ad eccezione di larix che raggiunge percentuali inferiori a 1% e di cui non si rinvengono più i macroresti a partire da 135 cm di profondità. rimangono costanti le percentuali di pinus, abies e pinus cembra. si distingue una fase a salix, di cui sono stati osservati anche i macroresti. nella cht9 (35-15 cm), ultimo spettro del diagramma, è da rilevare la presenza del polline di taxa legati all’antropizzazione, quali castanea, olea ed i cereali, una riduzione delle percentuali di abies, pinus cembra ed un aumento invece delle erbacee con poaceae, artemisia e cyperaceae. quest’ultima biozona si correla con le biozone chl2 e chl3 del diagramma del lago di champlong; con la sovrapposizione dei due diagrammi si può ricostruire la sequenza completa della vegetazione olocenica. 201evoluzione altitudinale spazio-temporale ... il lago di champlong (fig. 4) ha avuto una sedimentazione di gyttia omogenea e apparentemente non perturbata permettendo quindi di stimare la velocità di sedimentazione media di 0,03 cm/anno. la chl1 (310-291 cm), la cui parte basale è datata 3805±70 bp, è caratterizzata dal polline di taxa erbacei quali cichorioideae, ranunculaceae, rumex. tra i taxa arborei si riscontrano percentuali di 40% di pinus e 7% di pinus cembra. la biozona chl2 (291-265 cm) è state definita sulla base dell’inizio della curva continua di alnus glutinosa/incana, di alnus viridis e di picea; si osserva la diminuzione delle erbacee e la curva continua delle cyperaceae. inoltre è stato rinvenuto l’ultimo resto legnoso della sequenza determinato come pinus tp.cembra. la biozona chl3 (265-240 cm) è caratterizzata dalla riduzione delle percentuali e delle concentrazioni di pinus; aumentano invece le cichorioideae, rosaceae, rumex e botrychium tp. la biozona chl4 (240-220 cm) corrisponde ad una nuova diminuzione dei taxa erbacei ma si verifica una risalita delle percentuali di betula, pinus e di alnus glutinosa/incana. la biozona chl5 (220-190 cm) è caratterizzata dalla diminuzione delle percentuali di pinus, dall’aumento di alnus viridis, castanea, juglans, plantago tp. alpina, cereali, rumex e artemisia. il diagramma della torbiera di sant’anna (fig. 5), situata a 2304 m s.l.d.m. in val di gressoney, riporta gli eventi vegetali a partire da circa 9200 bp; è stato suddiviso in 9 biozone e sono state effettuate 4 datazione 202 fig. 3 diagramma pollinico semplificato della torbiera di champlong. il quadrato indica la presenza di macroresti. pollen percentage diagram from champlong peat bog including major taxa. the square shows macroremains. e. brugiapaglia 203 fig. 4 diagramma pollinico semplificato del lago di champlong. il quadrato indica la presenza di macroresti. pollen percentage diagram from champlong lake including major taxa. the square shows macroremains. fig. 5 diagramma pollinico semplificato della torbiera di sant’anna. il quadrato indica la presenza di macroresti. pollen percentage diagram from sant’anna peat bog including major taxa. the square shows macroremains. evoluzione altitudinale spazio-temporale ... assolute (tab. 1). la biozona a1 (145-135 cm) è caratterizzata dal polline di pinus (65%) con concentrazione di 4x103 p/g; le percentuali del polline di larix sono dell’1% ma la presenza in situ non è dimostrata dai suoi macroresti; è invece sicuramente presente salix di cui sono stati determinati i resti legnosi. le spore di selaginella tp. selaginoides compaiono per la prima volta con valori elevati (15%). la biozona a2 (135-115 cm) è caratterizzata dall’aumento delle percentuali di larix (10%), delle sue concentrazioni (103 p/g) e dalla riduzione delle spore di selaginella tp. selaginoides. la parte superiore di questa biozona è stata datata 6770+120/-115 bp. la biozona a3 (115-100 cm) è caratterizzata dal massimo delle percentuali di larix (15%) e dalla riduzione del polline di pinus e delle spore di selaginella. inizia la presenza continua di alnus glutinosa/incana e di alnus viridis. la biozona a4 (100-90 cm) è stata individuata per il picco delle concentrazioni di pinus (5x104 p/g), di pinus cembra ed una fase ad erbacee (cichorioideae, apiaceae, ranunculaceae, caryophyllaceae) accompagnata dalla riduzione del polline di alnus glutinosa/incana e larix. la biozona a5 (90-80 cm) è invece caratterizzata dalla diminuzione delle percentuali e delle concentrazioni di pinus, la riespansione di alnus glutinosa/incana, l’espansione di alnus tp. viridis, selaginella tp. selaginoides ed un aumento delle apiaceae e delle cichorioideae. nella biozona a6 (80-65 cm) si assiste ad un aumento delle percentuali di abies e all’alta presenza di pinus senza tuttavia aver osservato i loro macroresti. il brusco innalzamento delle percentuali delle cyperaceae potrebbe essere indicatore di uno hiatus nella sedimentazione: infatti la stratigrafia risulta assai complessa ma è stata rappresentata in maniera semplificata nel diagramma di figura 5. la biozona a7 (65-55 cm) corrisponde ad una diminuzione delle percentuali di pinus, alla risalita delle poaceae, delle cichorioideae nonché alla ricomparsa delle spore di selaginella tp. selaginoides. la biozona a8 (55-30 cm), che corrisponde all’inizio delle curva del polline di picea, è stata datata, nella parte basale, 1850±55 bp. si osserva una nuova avanzata delle cyperaceae, cichorioideae ed un riduzione delle poaceae. nella biozona a9 (30-10 cm) è evidente la riduzione di tutto il pa, mentre si osserva un aumento nelle presenze di saxifraga tp. oppositifolia, saxifraga tp. stellaris, selaginella tp. selaginoides, plantago tp. alpina, asteroideae, helianthemum e rosaceae. sull’altipiano, in corrispondenza di alcuni lavori di scavo per la realizzazione di un impianto di risalita, sono venuti alla luce diversi frammenti legnosi di larix e pinus cembra di cui però non è stato possibile stabilire l’esatta posizione stratigrafica. 5. discussione l’utilizzo di sequenze provenienti da diverse altitudini è certamente un aspetto favorevole per lo studio del limite altitudinale delle singole specie arboree dopo l’ultimo massimo glaciale. purtroppo quelle provenienti da siti superiori ai 2300 m non sempre contengono informazioni complete per la presenza di hiatus nella sedimentazione e nella maggior parte dei casi si tratta di sedimento troppo recente che non offre un valido supporto per analizzare gli eventi vegetali tardoglaciali. la posizione della valle d’aosta, la sua esposizione e quindi le sue caratteristiche climatiche sono i fattori che hanno influenzato in maniera decisiva il ritiro precoce dei ghiacci favorendo l’inizio di una sedimentazione già a partire da 12000 bp nei siti a 2300 m. dal punto di vista metodologico è quindi di fondamentale importanza la scelta dei siti da analizzare e l’utilizzo dell’analisi pollinica supportata da quella dei macroresti vegetali e dalle concentrazioni. i diagrammi delle torbiere di pilaz e champlong sono i più idonei per studiare il limite altitudinale degli alberi durante il tardoglaciale e per evidenziare le differenze dell’evoluzione della vegetazione ad altitudini differenti: infatti essendo i due siti localizzati rispettivamente a 1900 e 2320 m d’altitudine sullo stesso versante (fig. 1), dovrebbero aver registrato la stessa pioggia pollinica e, attraverso i macroresti, si può valutare l’evoluzione della vegetazione eliminando l’effetto del trasporto pollinico a media e lunga distanza. il confronto con il diagramma ottenuto dalla torbiera di s. anna a 2300 m, ha permesso di evidenziare come ad altitudini analoghe, il fattore umidità abbia inciso sulla diffusione delle specie vegetali arboree, arbustive ed erbacee (heiri et al., 2006). nella tabella 3 sono riportati i risultati delle analisi delle 4 sequenze correlate in base alle analogie tra le composizioni floristiche delle biozone e delle loro datazioni. > 12000 bp: nessuna datazione ricopre questo periodo. l’unica datazione nella biozona p1 ha avuto come risultato 9630±145 bp e sembra essere troppo giovane se confrontata con la composizione pollinica della biozona stessa: infatti se accettassimo questa datazione dovremmo escludere quelle dei livelli superiori che invece sono coerenti con la composizione pollinica del periodo, anche se sembrano esse stesse troppo recenti. probabilmente questo sedimento è stato interessato da uno hiatus, testimoniato dal brusco aumento delle ranunculaceae acquatiche, presente in corrispondenza del cambio di sedimentazione, e potrebbe essere la causa delle datazioni troppo recenti ottenute dai macroresti prelevati. le biozone p1 e cht1, caratterizzate da un sedimento argilloso, dall’assenza quasi totale di macroresti, ad esclusione di un frammento di legno attribuito a larix/picea e alcuni aghi di larix, e dalle concentrazioni estremamente basse, rivelano condizioni ambientali caratteristiche dell’ultimo interstadiale (last glacial interstadial = lgi) con scarsa vegetazione, che comprendeva esemplari isolati di larix e betula che crescevano su suolo estremamente povero. l’assenza di polline di larix, ma la presenza di macroresti (legno e aghi), può essere la conseguenza della sterilità di questi esemplari che vegetavano al limite delle loro condizioni vitali. 12000 10700 bp: (cht2, p2, p3) a champlong e pilaz doveva essere ancora presente una vegetazione erbacea steppica; si verifica tuttavia un aumento, rispetto alla biozona precedente, delle concentrazioni di pinus (11,7x103 p/g), di artemisia (2,4x103 p/g) e delle 204 e. brugiapaglia 205 torbiera pilaz torbiera lago torbiera principali eventi vegetali champlong champlong s. anna p11 chl5 a9 chl4 a8 1850±55 bp chl3 p10 a7 255±55 bp hiatus hiatus cht9 chl2 a6 2900±75 bp a5 p9 cht8 chl1 a4 3805±70 cht7 a3 p8 6770+120/-115 bp cht6 a2 7865±75 bp 8110±75 bp p7 cht5 a1 p6 9170+215/-210 bp p5 cht4 p4 cht39985±95bp 10790±100 bp p3 cht2 p2 11860±110 bp p1 cht1 9630±145 bp tabella 3 correlazione tra i diagrammi. correlation between the diagrams. 2500 5000 8000 9000 10000 10700 12000 diminuzione delle percentuali di pinus, massimo di juglans e castanea . aumento delle percentuali del pna. picco di pinus e picea. diminuzione del pna. aumento del polline non arboreo pna. diminuzione di abies e espansione di picea . a pilaz dominano larix ed ericaceae. s. anna è asilvatico, ma forse erano presenti solo rari larix, presenza invece di molti taxa di pascolo e prateria. alla torbiera di champlong macroresti di p. cembra, presenza continua polline di larix (<1%). si diffonde abies. a pilaz e a s. anna è presente larix . alla torbiera di champlong è presente p. cembra, una fase a salix e qualche larix. picco di betula a champlong e pilaz. l’inizio della curva continua di abies permette di correlare i diagrammi di pilaz e champlong; a pilaz abies è in situ con larix e qualche raro p. cembra, a champlong ci sono p. cembra e betula (cht6). a s. anna abies è stato registrato (5%) già a partire da 9000 bp. a s. anna e champlong sono presenti resti di salix. percentuali elevate di pinus. differenziazione della vegetazione in funzione dell’altitudine: a pilaz dominano larix e betula; a champlong pinus cembra e larix; a s. anna larix e salix. aumentano le percentuali e le concentrazioni di pinus, betula e larix. riduzione delle concentrazioni di tutti i taxa. aumento delle concentrazioni di pinus, poaceae, artemisia. diminuiscono le percentuali di artemisia. basse percentuali e concentrazioni del polline arboreo (ap), domina artemisia. poaceae (5,7x102 p/g). i l sedimento argil loso di champlong è quasi privo di macroresti, ma viene osservata per la prima volta una tracheide di betula, testimoniando della presenza di qualche raro esemplare di questo taxon nei pressi della torbiera o nell’altopiano sottostante la torbiera, e semi di saxifraga sp. sia a pilaz che a champlong la presenza del polline di juniperus e betula è contemporanea diversamente da quanto avviene comunemente nella dinamica vegetale al passaggio dal glaciale al lgi, in cui la prima specie pioniera è juniperus. i due taxa, viste le basse percentuali, erano abbastanza rari, ma a pilaz, dove sono stati identificati i frutti di betula, erano sicuramente presenti degli individui. le due popolazioni non avevano nè rapevoluzione altitudinale spazio-temporale ... porti dinamici nè di competizione, ma colonizzavano aree con caratteristiche ecologiche diverse: betula su suoli poveri e depositi morenici, mentre juniperus vegetava su suoli in via di evoluzione. a pilaz le concentrazioni di pinus, artemisia e poaceae aumentano rispetto alla biozona precedente ed inoltre si può considerare continua la presenza di larix, di cui sono stati determinati gli aghi, numerosi, leggeri e facilmente trasportabili dal vento, che probabilmente viveva sui rilievi che circondano l’attuale torbiera, ma non è da escludere che potesse colonizzare i versanti sottostanti la torbiera ed esposti a sud. la presenza precoce di larix in questo settore delle alpi sia a bassa altitudine (schneider, 1978) che ad altitudine elevata (brugiapaglia, 1997) è già nota. la torbiera doveva essere attraversata da un corso d’acqua formatosi dopo lo scioglimento dei ghiacci vista la presenza dei semi di ranunculus acquatico (probabilmente da riferire all’attuale racunculus aquatilis) che vive in acque correnti abbastanza veloci, fredde, particolarmente limpide e poco profonde con le radici ancorate al substrato, ed è assai frequente trovarlo in europa durante il dryas antico (reille, 1990, beaulieu et al., 1988). a pilaz la presenza di ranunculaceae acquatiche è elevata (50% e macroresti) nel lgi così come al lago hobschensee a 2017 m d'altitudine al passo del sempione (lang & tobolski, 1985) in cui il polline di ranunculaceae acquatiche è abbondante durante il lgi, mentre a cheylanes, a 1040 m nel massiccio centrale, è presente sia durante il dryas antico che per tutto l’interstadio tardoglaciale (beaulieu et al., 1988). intorno al lago erano presenti delle cinture di vegetazione colonizzate dalle specie in relazione alle loro esigenze ecologiche: hippuris vulgaris nelle zone con acque limpide e stagnanti, eleocharis nelle zone paludose e cyperaceae le cui numerose specie possono vivere sia in acqua che nella palude. all’aumento delle cyperaceae in p3 corrisponde la riduzione delle ranunculaceae acquatiche probabilmente da imputare alla naturale dinamica delle aree lacustri; tuttavia questo evento non è evidente nella stratigrafia del carotaggio e tantomeno dalla presenza di semi di carex che invece cominciano a comparire solo tra 220 e 225 cm di profondità. le biozone comprese in questo periodo, appartenenti all’ultimo interstadiale, evidenziano il carattere periglaciale del sito di champlong rispetto a quello di pilaz in particolare per l’assenza di vegetazione forestale e di vegetazione acquatica in cht2. per contro la vegetazione erbacea steppica stava diffondendosi come dimostra il polline di rumex, caryophyllaceaee semi di saxifraga sp. i fattori limitanti per lo sviluppo della vegetazione dovrebbero essere stati le caratteristiche pedologiche, la temperatura dell’acqua e la sua profondità. 10700 10000 bp (p4, cht3): a 1900 e a 2300 m le curve delle frequenze dei principali taxa arborei hanno lo stesso andamento, ossia la riduzione delle percentuali di pinus, più evidente a pilaz che a champlong e l’aumento delle percentuali di poaceae e di artemisia. rispetto alla cronozona precedente a champlong diminuiscono le concentrazioni di pinus, di artemisia e delle poaceae. a pilaz diminuiscono pinus e artemisia mentre le poaceae aumentano. a champlong, nel livello tra 390 e 400 cm, compaiono per la prima volta gli aghi di larix che potrebbero essere sia di origine locale, che trasportati dalle popolazioni viventi più in basso. il paesaggio era costituito essenzialmente da praterie steppiche fredde con chenopodiaceae, cichorioideae, asteroideae, caryophyllaceae, apiaceae, ranunculaceae e botrychium tp., e ambienti umidi con vegetazione a carex. anche a 1900 m questo periodo corrisponde ad un aumento delle specie erbacee in particolare aumentano le poaceae. la vegetazione lacustre-palustre era ancora presente così come nella biozona precedente benchè le percentuali delle ranunculaceae acquatiche subirono un forte calo legato probabilmente alla sedimentazione che passa da gyttja a torba. tra le specie arboree betula, di cui sono presenti i frutti ed il legno, caratterizzava il paesaggio forestale a scapito di larix di cui non sono stati osservati i macroresti e che probabilmente subì una riduzione. sulla base della composizione floristica queste biozone possono essere attribuite all’ultima oscillazione fredda del tardoglaciale. 10000 9000 bp (p5, cht4): le due biozone sono caratterizzate dall’aumento delle percentuali e delle concentrazioni di betula (4,8x103 p/g; 5,7x102 p/g), larix (3,8x102 p/g; 7,1x102 p/g) e pinus (12x103 p/g; 18,4x103 p/g). la datazione della parte basale della biozona cht4, che ha dato come risultato 9030±95 bp, non è stata presa in considerazione nell’interpretazione dei dati: infatti sembra essere troppo recente se confrontata con la composizione pollinica della biozona tipica dell’olocene iniziale. questa datazione, vista l’assenza di altri macroresti, è stata ottenuta su carboni che non sono i migliori resti da datare perché presentano problematiche legate ai movimenti nel suolo (carcaillet, 2001). si può tuttavia ipotizzare la validità della datazione ma in questo caso dovremmo ammettere la presenza di uno hiatus di sedimentazione in corrispondenza del passaggio dal tardoglaciale all’olocene che non è tuttavia evidente dal diagramma pollinico. in questo periodo è da rilevare la riduzione delle percentuali di poaceae e di artemisia, nonché a pilaz la scomparsa del poll ine e dei macroresti di ranunculaceae acquatiche da cui si evince che oramai il livello delle acque si era definitivamente abbassato con la continuazione della deposizione della torba iniziata nel periodo precedente. il rapporto ap/nap è a favore del polline arboreo ed in particolare a pilaz la specie dominante è larix così come a champlong in cui, sulla base della presenza dei macroresti, si evince che il ruolo pioniero lo ha svolto larix invece di betula la quale dovrebbe essersi espansa solo successivamente considerando che i suoi macroresti compaiono a circa 8100 bp. a pilaz sembra che betula abbia avuto un ruolo pioniero, ma non è possibile stabilirlo con certezza in quanto i macroresti di questo taxon compaiono contemporaneamente a quelli di larix. un’altra differenza nella dinamica vegetale della colonizzazione postglaciale è la presenza, a pilaz, di un leggero aumento delle percentuali (< 5%) di juniperus assente invece a champlong. quindi a pilaz erano presenti contemporaneamente due taxa pionieri (juniperus e betula) che dimostrano come il sito fosse caratterizzato da un mosaico di situazioni ecologiche differenti: juniperus, che attualmente rientra nella dinamica della serie dei 206 e. brugiapaglia boschi meso-termofili e termofili di cembro e larice, colonizzava suoli superficiali e rocciosi, mentre betula colonizzava i terreni grezzi tipo le morene essendo una specie pioniera che si adatta a tutti i substrati (rameau, 1993). 9000 8000 bp (p6, p7, cht5, a1): è da mettere in evidenza la diversa sedimentazione tra champlong (10 cm di sedimento) e pilaz (65 cm di sedimento) determinando quindi una maggiore risoluzione nella registrazione degli eventi vegetali in quest’ultimo sito. a pilaz infatti si può individuare una subzona (p6), in cui lo spettro di 200 cm è il più significativo, con carattere aridofilo poco evidente invece a champlong. questa fase arida ha determinato lo sviluppo di una prateria a cichorioideae, apiaceae, leguminosae, campanulaceae, pteridium e cyperaceae. un periodo di aridità e di basso livello dei laghi è stato anche ritrovato da magny (2004) nel giura tra le fase 15 e 14 nonchè nelle alpi centrali dell’austria (schmidt et al., 2006). a 1900 m la vegetazione forestale era dominata da larix mentre nelle zone di margine era probabilmente presente un prebosco a betula. a 2300 m la vegetazione forestale era caratterizzata da pinus cembra, pinus sylvestris e larix (4%) di cui tuttavia non sono stati rinvenuti i macroresti, ma la percentuale elevata fa ritenere che il popolamento di larice fosse molto esteso e denso. benchè il confronto tra la vegetazione delle due altitudini sia reso più complesso dalla differente sedimentazione, anche a champlong è evidente una fase ad erbacee tra cui artemisia, apiaceaee e urticaceae. e’ in corrispondenza di questa biozona che si manifesta in maniera decisa la differenza tra la vegetazione forestale in relazione all’altitudine: a pilaz dominavano larix e betula, mentre a champlong pinus cembra e larix. un’ipotesi per spiegare la presenza e lo sviluppo di una cembreta a 2300 m senza averne mai trovata prima a 1900 m, sarebbe quello di ammettere che pinus cembra si sia diffuso dall’adiacente val d’ayas attraverso l’attività disseminatrice della nocciolaia (nucifraga caryocactes) che può rendere difficile interpretare la distribuzione dei popolamenti (mattes, 1984). a sant’anna, in val di gressoney all’altitudine di 2304 m, potrebbe essere stata presente una vegetazione arborea a dominanza di larix, con delle vallette, a maggiore ristagno idrico, in cui vegetavano selaginella tp. selaginiodes e salix, di cui sono stati determinati i resti legnosi. le percentuali elevate di selaginella tp. selaginiodes (15%) non sono state osservate in nessuno dei diagrammi analizzati; ciò potrebbe essere legato alla maggiore umidità della valle che ancora oggi è considerata una delle più piovose dalla valle d’aosta (mercalli et al., 2003). inoltre, la mancanza totale di juniperus, che è invece presente, anche se con basse percentuali, nei settori valdostani particolarmente aridi, potrebbe essere indicatrice di elevata umidità. 8000 5000 bp (p8, cht6, cht7, a2, a3): si realizza la diffusione dell’abete bianco (abies alba) e l’aumento di alnus glutinosa/incana. abies era sicuramente presente a pilaz, in cui sono stati osservati i resti legnosi, mentre nei siti ad altitudine più elevata, non è stato possibile stabilirne la reale presenza per la loro mancanza. a pilaz la sua diffusione è preceduta da una fase a betula, la quale si osserva sempre sia nelle fasi evolutive che degradative della vegetazione forestale. sia a pilaz che a champlong è da rilevare la riduzione delle percentuali di larix ed a pilaz compaiono i resti di pinus cembra. e’ da osservare inoltre l’aumento delle percentuali di alnus glutinosa/incana indicatore dell’aumento dell’umidità (david, 1993b). a champlong si possono distinguere due fasi: la cht6 più umida che avrebbe favorito l’espansione di pinus cembra ed una più arida (cht7) che avrebbe invece avvantaggiato larix. questa ipotesi è anche suffragata dal sedimento che passa da gyttja a torba e dall’aumento delle cyperaceae, testimoniando quindi un interrimento del lago. successivamente a 8100 bp, a champlong erano presenti betula e pinus cembra, mentre in cht7, si osservano betula e larix. la fase umida e fredda, caratterizzata dalla diffusione di abies, può essere correlata con la fase 12 di alto livello lacustre in magny (2004) nonché con la fase umida e fresca a 8200 bp ai laghi di monticchio (allen et al., 2002). una fase più fresca e umida è evidente in diversi siti delle alpi e della regione mediterranea come evidente in schmidt et al. (2006). in questo periodo la vegetazione arborea subisce una riduzione, in particolare pinus di cui si riducono le concentrazioni e come conseguenza si verifica la diffusione della vegetazione arbustiva a ericaceae e juniperus. la biozona a2 può essere correlata con il periodo più umido e freddo per la presenza delle spore di selaginella tp. selaginiodes senza tuttavia rilevare un aumento di alnus glutinosa, mentre a3, che vede la riduzione fino alla scomparsa delle spore di selaginella tp. selaginiodes ed percentuali elevate di larix (15%) potrebbe corrispondere ad una fase di aridità benchè sia presente alnus glutinosa/incana con percentuali dell’8% aumentando rispetto alla biozona precedente. questa biozona potrebbe essere correlata con la fase lacustre 11 in magny (2004). alla torbiera di champlong e di sant’anna è stata registrata solo la pioggia pollinica di abies (<10%) e l’assenza di macroresti ci induce a credere che abies non raggiunse l’altitudine di 2300 m benchè sant’anna si trovi in un settore piovoso della valle d’aosta, ma l’altitudine (durata della copertura nevosa, insolazione) può aver rappresentato un fattore limitante non compensato dall’umidità elevata. 5000 2500 bp (p9, cht8, chl1, chl2, a4, a5, a6): questo periodo è di difficile delimitazione ed identificazione attraverso la composizione vegetale e le datazioni assolute. inoltre diventa estremamente complesso discernere tra fattori naturali ed impatto antropico, fattore quest’ultimo che comincia ad essere importante. l’aumento progressivo delle specie legate al pascolo tra cui le poaceae e le cichorioideae in cht8, nonché in p9, in a4 e a5 è ben evidente; la scomparsa delle cyperaceae (a4 e a5) o la loro riduzione (p9, cht8) dimostrano un’intensa attività pascoliva ed infatti è evidente il corrispondente aumento delle cichorioideae, artemisia, campanulaceae ed apiaceae. l’apparente contraddizione della diffusione di alnus glutinosa/incana in a5 è strettamente legata al clima che è più umido e ben si correla con l’alto livello dei laghi osservato nella fase 9 in magny (2004). il periodo in questione è caratterizzato da numerose fluttuazioni del livello lacustre (magny, 2004) nonché dei ghiacciai (joerin et al., 2006) ed alcune si correlano con la biozona a4 (nicolussi & patzel, 2000; joerin et al., 2006). per i taxa 207evoluzione altitudinale spazio-temporale ... arborei, dopo la massima presenza di abies, comincia la definitiva riduzione come dimostra anche l’assenza totale dei macroresti a partire da 90 cm alla torbiera di pilaz in cui la vegetazione arborea delle aree limitrofe doveva essere costituita solo da qualche raro larix. l’utilizzo intensivo del territorio anche a bassa altitudine è evidente dalla comparsa, per la prima volta, a pilaz dei pollini di juglans e castanea. sono da inquadrare in questo periodo di completo disbosco i resti vegetali (larix e pinus cembra) portati alla luce dagli scavi per la costruzione della nuova funivia nei pressi della torbiera di sant’anna. al lago di champlong in questa fase il polline di abies raggiunse percentuali molto basse (2%) ed invece si espandono le specie erbacee di prateria (cichorioideae, artemisia, apiaceae, ranunculaceae, campanulacae, rumex). si può quindi ipotizzare la presenza di un ambiente aperto con alcuni pini, di cui sono stati osservati aghi e legno, che colonizzavano le ripide pareti circostanti il versante sud-est del lago oppure vegetavano sui pendii sottostanti l’altipiano. chl1 corrisponde ad un periodo di forte utilizzazione dell’altipiano nei cui pressi è stato rinvenuto un villaggio risalente all’età del bronzo. non è da escludere tuttavia anche la possibilità di un periodo particolarmente arido che potrebbe corrispondere alla fase 7 (magny, 2004) con un basso livello dei laghi. proprio questo periodo di miglioramento climatico avrebbe favorito l’occupazione umana nei siti di altitudine almeno durante la stagione favorevole. < di 2500 bp (p10, p11, cht9, chl3, chl4, chl5, a7, a8, a9): questo è il periodo più recente ed il confronto tra le varie biozone risulta alquanto complesso per evidenti interventi antropici sul territorio. a s. anna ed a pilaz sembra evidente la presenza di hiatus; in particolare nella sedimentazione di s. anna, nella biozona a7 la presenza di argilla siltosa potrebbe indicare una fase umida con notevole apporto di materiale colluviale, nonché il brusco picco di selaginella tp. selaginoides indicherebbe sia uno hiatus (asporto di sedimento) che una fase di umidità elevata. l’andamento delle curve di pinus e poaceae in chl3, chl4, a7 e p10, è analogo, ossia la riduzione del primo e l’aumento delle seconde. questa fase umida si correla con la fase 5 (magny, 2004) di innalzamento del livello lacustre e con le oscillazioni climatiche umide dell’europa centrale (haas et al.,1998). a questa fase umida però non è correlata una diminuzione delle temperature: infatti non sono evidenti avanzate dei ghiacciai (joerin et al., 2006) e non ci sono indici da abbandono dei siti di altitudine, ma al contrario dai diagrammi è evidente una forte pressione antropica attraverso la pastorizia. la datazione di 255±55 bp della biozona p10 alla torbiera di pilaz sembra essere troppo recente in quanto si colloca dopo la comparsa del polline di juglans e castanea che nelle aree alpine compare intorno a 2000 bp. probabilmente in questa parte della sequenza è presente uno hiatus nella sedimentazione, benchè sembri omogenea, tuttavia un inaridimento della vegetazione è evidente dall’aumento delle rosaceae, di plantago tp. alpina, delle campanulaceae, di viola e larix e dalla sostituzione di abies con picea. in tutti i diagrammi, ma in misura inferiore a s. anna, è evidente l’inizio della coltivazione dei cereali, la segale, in particolare, che tutt’oggi viene coltivata fino a 1800 m (gatto chano & cerutti, 2003). tra le specie arboree che si diffondono durante questo periodo, ma che non raggiungono i siti studiati, troviamo picea e fagus. in particolare, alla torbiera di pilaz dove sono presenti dei larici, di cui sono stati determinati gli ultimi macroresti a 55 cm, viene registrata anche la presenza di picea, ma il sito era principalmente caratterizzato da praterie arbustate a ericaceae e calluna con cichorioideae, apiaceae, plantago tp. alpina, rosaceae, campanulaceae, rumex. le zone più umide nei pressi della torbiera erano probabilmente dominate da cyperaceae e selaginella tp. selaginiodes. anche al lago di champlong è evidente esclusivamente vegetazione erbacea ed arbustiva ad ericaceae e juniperus: infatti gli ultimi resti arborei di pinus cembra sono alla profondità di 295 cm (chl2). il paesaggio vegetale si presentava quindi simile a quello attuale con lande a juniperus e rhododendron. un elevato impatto antropico a champlong è testimoniato dalla presenza di un villaggio che è stato attribuito all’età del bronzo (i sec. a.c.): si dovrebbe trattare di un villaggio stagionale a 2437 m sotto il monte tantanè in cui sono ancora in corso gli scavi e di cui è sconosciuta l’utilizzazione (mezzena, 1981; mezzena, 1997). a sant’anna (a7, a8, a9) non sono stati osservati macroresti di taxa arborei, quindi il sito era probabilmente occupato da un mosaico di ambienti erbacei in particolare da praterie umide e pascoli xerici. le popolazioni di picea dovevano trovarsi poco al disotto dell’altipiano e dovevano avere l’aspetto e l’estensione dei popolamenti attuali. le percentuali di larix, sempre inferiori a 1%, indicano la presenza di qualche esemplare isolato sull’altipiano (malaussena, 1984; brugiapaglia, 1997). 6. conclusioni i diagrammi pollinici della torbiera e del lago di champlong, della torbiera di pilaz e di s. anna, rappresentano l’andamento del clima e della vegetazione per il periodo successivo a 12000 anni. il glaciale e l’ultimo interstadio glaciale sono registrati nei diagrammi pollinici della torbiera di champlong e di pilaz, mentre l’olocene è presente in maniera abbastanza completa in tutti i diagrammi. sono stati evidenziati problemi di datazione soprattutto per la torbiera di champlong in cui l’assenza di macroresti nelle argille ha impedito di definire una precisa cronologia tardoglaciale. la figura 6 e la tabella 4 sintetizzano l’evoluzione e le variazioni temporali del limite altitudinale degli alberi a partire dall’ultimo interglaciale a tutt’oggi. l’evoluzione spaziale della treeline è di difficile quantificazione, ma si possono fare delle valutazioni qualitative sulla composizione forestale di siti. durante il tardoglaciale i due siti erano già liberi dai ghiacci, in particolare pilaz si trovava poco al di sopra della treeline composta da larix e betula. la treeline si mantiene a circa 1900 m da 12000 a 10000 bp composta da betula, juniperus e larix. a partire da 10000 bp la treeline si può localizzare oltre i 2300 m caratterizzata da larix. il periodo compreso tra 9000 e 5000 bp è stato il più favorevole per cui gli alberi si sono spinti ad altitudini elevate ed hanno dato luogo a formazioni arboree 208 e. brugiapaglia dense (timberline) almeno fino a 2300 m. per questo periodo non si può valutare il limite della treeline in quanto non sono stati trovati, nel settore studiato, siti idonei all’analisi pollinica oltre i 2300 m d’altitudine. tuttavia si può ritenere che il limite superiore degli alberi fosse a circa 2550 m, in accordo con quanto è conosciuto sulle alpi svizzere (wick & tinner, 1997; tinner & theurillat, 2003). questo intervallo temporale corrisponde all’optimum climatico favorevole allo sviluppo della vegetazione anche in altitudine visto l’importante ritiro dei ghiacciai. secondo le ricostruzioni paleoclimatiche di davis et al. (2003) per l’europa centrale il periodo con le temperature più elevate è 6000 bp. sempre in questo intervallo di tempo si sarebbe formata la torba sul fronte del ghiacciaio rutor a 2510 m sl.d.m e burga (1995) considera che tra 8000 e 5000 bp ci sia stato l’optimum climatico per la vegetazione forestale che si sarebbe spinta tra 2100 e 2300 m d’altitudine così come era stato evidenziato anche da porter & orombelli (1985) per il settore occidentale della valle d’aosta. aceti (2006) rianalizzando la torba del rutor conclude che la fase di recessione del ghiacciaio è tra 9000 e 6500 cal bp. wick & tinner (1997) stimano che la maggiore elevazione della timberline sia stata raggiunta tra 8700 e 5000 bp sia sulle alpi italiane che su quelle svizzere. successivamente a questo periodo di massima elevazione della vegetazione forestale si sarebbe verificata una forte riduzione in corrispondenza dell’espansione delle popolazioni dell’età del bronzo; risale a questo periodo il ritrovamento, sotto il monte tantanè che sovrasta i siti di pilaz e champlong, di un insediamento 209 fig. 6 evoluzione qualitativa e temporale della componente arborea e arbustiva nei siti analizzati temporal and qualitative evolution of the scrubb and tree in the study area tab. 4 principali specie che hanno colonizzato la treeline e la timberline a partire da 12000 bp. main species which have colonized the treeline and timberline from 12000 bp. < 2500 bp treeline 2300 m pinus cembra timberline 1900 m larix e picea 5000-2500 bp treeline 2300 m pinus e larix timberline 1900 m abies e larix 8000-5000 bp treeline >2300 m timberline 2300 m pinus cembra, betula e larix 9000-8000 bp treeline >2300 m timberline 2300 m pinus cembra, pinus sylvestris e larix 10000-9000 bp treeline >2300 m larix timberline ? larix 10700-10000 bp treeline 1900 m betula timberline ? 12000-10700 bp treeline 1900 m betula, juniperus e larix timberline <1900 m > 12000 bp treeline al di sotto di 1900 m larix e betula timberline ? evoluzione altitudinale spazio-temporale ... stagionale legato probabilmente allo sfruttamento minerario con tracce di attività agricola e tessile (mezzena, 1981; mezzena, 1997; gatto chanu & cerutti, 2003). quindi tra 5000 e 2500 bp la treeline si abbassa definitivamente e, dai macroresti osservati, è composta essenzialmente da larix e pinus. successivamente a 2500 bp la treeline si attesta sui 2300 m e l’ultimo macroresto vegetale è legno di pinus tp. cembra. l’occupazione di essenze forestali in zone elevate, è testimoniata anche dai numerosi rinvenimenti noti per la valle d’aosta (monterin, 1936 in cerutti, 1997): in particolare per la valle di gressoney di fronte al ghiacciaio di verra a 2250 m dove è stato rinvenuto un tronco di picea abies, pinus cembra all’alpe bett a 2200 m d’altitudine e all’alpe gabiet a 2350 m. purtroppo per questi tronchi non è conosciuta l’età assoluta, ma secondo l’autore risalgono all’optimum climatico medioevale. l’area indagata presenta ancora delle notevoli potenzialità per studiare le correlazioni tra le attività umane e l’evoluzione del paeaggio tentando quindi di valutare l’impatto del clima rispetto alle attività umane ed apportando nuove conoscenze che possono essere integrate con quelle già note per realizzare un modello climatico previsionale. bibliografia aceti a. (2006) the early holocene climate optimum: evidence from high-altitude peat deposits in the italian alps. in : inqua-seqs "quaternary stratigraphy and evolution of the alpine region in the european and global framework. 11-15 settembre 2006, pp. 48-49. allen j.r.m., watts w.a., mcgee e., huntley b. (2002) holocene environmental variability – the record from lago grande di monticchio, italy. quat. internat., 88, pp. 69–80. ammann b. & wick l. (1993) analysis of fossil stomata of conifers as indicators of the alpine tree line fluctuations during the holocene. in : oscillations of the alpine and polar tree limits in the holocene. esf project european palaeoclimate and man, 9, pp. 175-185. anderberg a. -l. (1994) atlas of seeds. part 4. swedish museum of natural history. beaulieu de j.-l., pons a. & reille m. (1988) histoire de la flore et de la végétation du massif central (france) depuis la fin de la dernière glaciation. cahiers de micropaléontologie, n.s., 3(4), pp. 536. beniston m., diaz h.f. & bradley r.s. (1997) climatic change at hight elevation sites: an overview. climatic change, 36, pp. 233-251. berggren g. (1969) atlas of seeds. part 2. swedish museum of natural history. berggren g. (1981) atlas of seeds. part 3. swedish museum of natural history. birks h.h. (2003) the importance of plant macrofossils in the reconstruction of lateglacial vegetation and climate: examples from scotland, western norway, and minnesota, usa. quaternary science reviews, 22, pp. 453-473. birks h.h. & birks h.j.b. (2000) future use of pollen analysis must include plant macrofossils. journal of biogeography, 27, pp. 31-35. brugiapaglia e. & barbero m. (1994) variation de la limite subalpin/alpin depuis la période atlantique sur le plateau du taillefer (isère, france). ecologie, 25(3), pp. 157-172. brugiapaglia e. (1997) paleobiogeografia in valle d’aosta a partire dall’ult ima glaciazione . biogeographia, 19, pp. 85-104. burga c.a. (1995) végétation et paléoclimatologie de l’holocene moyen d’une ancienne tourbière située au front du glacier du rutor, 2510 m (vallée d’aoste, italie). revue de géographie alpine, 1, pp. 9-16. carcaillet c. (2001) are holocene wood-charcoal fragments stratified in alpine and subalpine soils? evidence from the alps based on ams 14c dates. the holocene, 11(2), pp. 231-242. cerutti a.v. (1997) variazioni climatiche e oscillazione del limite altitudinale del bosco. in “uomini e boschi in valle d’aosta”. regione autonoma valle d’aosta. assessorato dell’agricoltura, forestazione e risorse naturali, pp. 25-35. david f. (1993a) altitudinal variation in the response of the vegetation to lateglacial climatic events in the northern french alps. new phytologist, 125, pp. 203-220. david f. (1993b) développement des aulnes dans les alpes françaises du nord. c.r.acad.sci., paris, 316, ii, pp. 1815-1822. david f., damblon f., farjanel g., juvigné e., streel m. & berthier f. (2006) variabilité des enregistrements polliniques en montagne et reconstructions paléoécologiques. belgeo, 3, pp. 265-278. davis b.a.s., brewer s., stevenson a.c., guiot j. & data contributors (2003) the temperature of europe during the holocene reconstructed from pollen data. quaternary science review, 22, pp. 1701-1716. erdtman g. (1936) new methods in pollenanalysis. svenk. bot. tidskr, 30(2), pp. 154-164. gatto chanu t. & cerutti a. v. (2003) guida insolita della valle d’aosta. newton & compton editori, 479 pp. goeury c. & de beaulieu j.-l. (1979) a propos de la concentration du pollen à l’aide de la liqueur de thoulet dans les sédiments minéraux. pollen et spores, 21 (1), pp. 239-251. goeury c. (1997) gestion, traitement et répresentation des données de la paléoécologie. xv symposium aplf, lyon, pp. 31. haas j.n., richoz i., tinner w., wick l. (1998) – synchronous holocene climatic oscillation recorded on the swiss plateau and at timberline in the alps. the holocene, 8(3), pp. 301-309. heiri c., bugmann w., tinner w., heiri o. & lischke h. (2006) a model-based reconstruction of holocene treeline dynamics in the central swiss alps. journal of ecology, 94, pp. 206-216. jacquiot c., (1955) atlas d’anatomie de bois des conifère. centre technique du bois, paris, 133 pp. joerin u.e., stocker t.f. & schlüchter c. (2006) multicentury glacier fluctuations in the swiss alps during the holocene. the holocene, 16 (5), 210 e. brugiapaglia pp.679-704. lang g. & tobolski k. (1985) hobschensee-late-glacial and holocene environment of a lake near the timberline. diss. bot., 87, pp. 209-228. magny m. (2004) holocene climate variability as reflected by mid-european lake-level fluctuations and its probable impact on prehistoric human settlements. quaternary international, 113, pp. 65-79. malaussena b. (1984) contribution à la connaissance de la production et de la dispersion pollinique de mélèze (larix decidua mill.) dans les alpes maritimes. d.e.a. université d'aix-marseille iii, 40 pp. mattes h. (1984) the role of animals in cembran pine forest regeneration. proc. 3 iufro workshop. eidg. anst. forstl. versuchswes, ber, 270, pp. 197-205. mercalli l., cat berro d., montuschi s., castellano c., ratti m., di napoli g., mortara g. & guindani n. (2003) atlante climatico della valle d’aosta. regione autonoma valle d’aosta, 405 pp. mezzena f. (1981) la valle d’aosta nella preistoria e nella protostoria. in "archeologia in valle d’aosta. dal neolitico alla caduta dell’impero romano 3500 a. c. – v sec. d. c.", quart – aosta. mezzena f. (1997) la valle d’aosta nel neolitico e nell’eneolit ico, in "atti della xxxi riunione scientifica: la valle d’aosta nel quadro della preistoria e protostoria dell’arco alpino centro-occidentale", courmayeur, 2-5 giugno 1994, firenze 1997. nicolussi k. & patzelt g. (2000) discovery of early holocene wood and peat on the forefield of the pasterze glacier, eastern alps, austria. the holocene, 10(2), pp.191-199. porter s. & orombelli g. (1985) glacier contraction during the middle holocene in the western italian alps: evidence and implications. geology, 13, pp. 296-298. rameau j.c., mansion d. & dumé g. (1993) flore forestière française. 2 montagnes. ministère de l’agricolture et de la pêche, 2421 pp. reille m. (1990) recherches pollenanalytiques dans l'extrémité orientale des pyrénées: données nouvelles, de la fin du glaciaire à l'actuel. ecologia mediterranea, 16, pp. 317-357. reille m. (1992) pollen et spores d'europe et d'afrique du nord. laboratoire de botanique historique et palynologie. université d'aixmarseille iii, 520 pp. reille m. (1995) pollen et spores d'europe et d'afrique du nord. supplement 1. laboratoire de botanique historique et palynologie. université d'aix-marseille iii, 327 pp. schmidt r., kamenik c., tessadri r., koinig k.a. (2006) climatic changes from 12,000 to 4,000 years ago in the austrian central alps tracked by sedimentological and biological proxies of a lake sediment core. journal of paleolimnology, 35, pp. 491-505. schneider r. (1978) pollenanalytische untersuchungen zur kenntnis der spätund postglazialen vegetationsgeschichte am südrand der alpen zwischen turin und varese (italien). bot. jb.syst., 100, pp. 26-109. schweingruber f.h. (1990a) mikroskopische holzanatomie. 3.aufl.birmensdorf, eidgenössische forschungsanstalt für wald, schnee und landschaft, 226 pp. schweingruber f.h. (1990b) anatomie europäischer hölzer.-anatomy of european woods. eidgenössische forschungsanstalt für wald, schnee und landschaft, birmensdorf (hrsg.). haupt, bern und stuttgart, 800 pp. stuiver m. & reimer p. j. (1993) calibration program rev.3.0.2. radiocarbon, 35, pp. 215-230. tinner w., ammann b. & germann p. (1996) treeline fluctuations recorded for 12500 years by soil profiles, pollen, and plant macrofossils in the central swiss alps. arctic and alpine research, 28, pp. 131-147. tinner w. & theurillat j.p. (2003) uppermost limit, extent, and fluctuations of the timberline and treeline ecocline in the swiss central alps during the past 11.500 years. arctic and alpine research, 35 (2), pp. 158-169. wick l. & tinner w. (1997) vegetation changes and timberline fluctuations in the central alps as indicators of holocene climatic oscillations. arctic and alpine research, 29, pp. 445-458. wick l. (2000) vegetational response to climatic changes recorded in swiss late glacial lake sediments. palaeogeography, palaeoclimatology, palaeoecology, 159, pp. 231-250. 211evoluzione altitudinale spazio-temporale ... ms. ricevuto il 30 maggio 2007 testo definitivo ricevuto il 6 novemvre 2007 ms. received: may 30, 2007 final text received: november 6 , 2007 variazioni morfologiche degli alvei dei principali corsi d'acqua veneto-friulani negli ultimi 200 anni nicola surian1, luca ziliani1, laura cibien1, alberto cisotto2 & francesco baruffi2 1dipartimento di geografia, università di padova, via del santo 26, 35123 padova 2autorità di bacino dei fiumi dell'alto adriatico, dorsoduro 3593, 30123 venezia e-mail: nicola.surian@unipd.it riassunto: surian n. et al., variazioni morfologiche degli alvei dei principali corsi d'acqua veneto-friulani negli ultimi 200 anni (it issn 0394-3356, 2008). i corsi d'acqua veneto-friulani, come molti corsi d'acqua italiani, sono stati soggetti negli ultimi decenni a profonde modificazioni morfologiche, indotte da una serie di interventi antropici. il lavoro riporta lo stato attuale delle conoscenze su cinque dei principali corsi d'acqua veneto-friulani (brenta, piave, cellina, tagliamento e torre), ed ha lo scopo di confrontare le tendenze evolutive ed i fattori che hanno determinato gli aggiustamenti morfologici nel breve e medio termine (ultimi 200 anni). le variazioni planimetriche, ed in particolare le variazioni di larghezza dell'alveo, sono state analizzate attraverso l'impiego della cartografia storica e delle foto aeree: per ogni corso d'acqua si è potuto disporre da un minimo di 9 ad un massimo di 12 documenti. lo studio delle variazioni altimetriche si è basato invece sul confronto di sezioni topografiche e sul rilevamento sul terreno. gli alvei, che hanno evidenziato delle tendenze evolutive molto simili fra loro, sono risultati complessivamente stabili nel corso del xix sec., mentre soggetti a significative modificazioni nel periodo seguente. per buona parte del xx sec., fino agli anni '80/'90, il restringimento e l'incisione dell'alveo sono stati i processi dominanti: rispetto al valore iniziale (prima metà del xix sec.) la riduzione della larghezza è stata del 50-70 %, mentre l'abbassamento del fondo è stato mediamente dell'ordine di 2-3 m, ma localmente anche di 8-9 m. negli ultimi 15-20 anni si è verificata, a parte il caso del torre, un'inversione di tendenza: i processi più diffusi sono stati infatti l'allargamento e la sedimentazione. quest'ultima fase di evoluzione degli alvei ha solo in parte compensato le modificazioni del periodo precedente. il prelievo dei sedimenti e le opere di difesa hanno avuto un ruolo determinante, in particolare nella fase di principale modificazione degli alvei (dagli anni '50 agli anni '80/'90). di minor impatto, almeno per i tratti d'alveo qui esaminati, risultano essere state le dighe (ad eccezione del cellina), le sistemazioni idraulico-forestali e la riforestazione. come evidenziato in studi precedenti, i vari interventi antropici hanno radicalmente alterato il regime del trasporto solido, mentre solo nel caso del cellina è stata riscontrata una variazione significativa delle portate formative. abstract: surian n. et al., channel adjustments of the main rivers of venetia and friuli venezia giulia over the last 200 years (it issn 0394-3356, 2008). the streams of the veneto and friuli venezia giulia regions, as many other italian streams, have undergone remarkable channel adjustments in the last decades, which have been induced by a range of human interventions. the paper, which reports the state of the art about five streams (brenta river, piave river, cellina torrent, tagliamento river and torre torrent), aims to compare the evolutionary trends of such streams and the factors that have driven to channel changes in the medium and short periods (last 200 years). the selected streams are relatively large (their drainage basins range between 446 km2 and 3899 km2) and have very wide gravel channels, often with a braided morphology, in the study reaches. planform changes, in particular channel width variations, have been analysed using maps and aerial photographs (9 to 12 different maps/photos were available for each stream). bed-level changes have been investigated through cross-section comparisons and field surveys. the river channels have shown very similar evolutionary trends and magnitude of adjustments. channel changes were not notable over the 19th century, whereas the channels have been in an unstable condition in the following period. narrowing and incision have been the dominant processes during the 20th century, up to the 1980s-1990s. channel width reduction has been of 50-70 %, referring to the width in the first half of the 19th century, and bed-level lowering of 2-3 m on average, but locally up to 8-9 m. a different evolutionary trend, except for the torre torrent, has occurred in the last 15-20 years, since channel widening and aggradation have been the most common processes. the magnitude of changes during the last phase has been generally much smaller in comparison with those of the previous phases of adjustment. the gravel mining and channelization works have been the main causes of channel changes, in particular as for the main phase of adjustment that took place from the 1950s to the 1980s/1990s. the dams (except for the cellina torrent), torrent control works, and reforestation have probably had a smaller effect on channel dynamics than mining and channelization. as pointed out in previous studies, it is confirmed that human interventions have dramatically altered the sediment regime, whereas a significant change of channel-forming discharges has been documented in just one case (cellina) parole chiave: alvei ghiaiosi, variazioni morfologiche, impatto antropico, italia nord-orientale. keywords: gravel-bed rivers, channel adjustments, human impact, north-eastern italy. il quaternario italian journal of quaternary sciences 21(1b), 2008 279-290 1. introduzione l'instabilità degli alvei indotta da interventi antropici e le conseguenti modificazioni morfologiche sono da numerosi anni un importante tema di ricerca nell'ambito della geomorfologia fluviale (le o p o l d, 1973; pe t t s, 1979; wi l l i a m s & wo l m a n, 1984; wy z g a, 1993; li e b a u l t & pi e g a y, 2001). come evidenziato recentemente da do w n s & gr e g o r y (2004) e da ha b e r s a c k & pi e g a y (2008) tali ricerche hanno, fra l'altro, rilevanti ricadute pratiche in quanto la conoscenza dell'evoluzione recente degli alvei è fondamentale nell'ambito della pianificazione, gestione e riqualificazione dei corsi d'acqua. questi aspetti risultano di particolare interesse nel contesto italiano, in quanto la maggior parte dei sistemi fluviali sono stati fortemente alterati da molteplici interventi antropici (prelievo di sedimenti, dighe, opere di canalizzazione, sistemazioni idraulico-forestali) con l'ef280 n. surian et al. fetto di considerevoli modificazioni nella morfologia e dinamica degli alvei (surian & rinaldi, 2003). i principali corsi d'acqua veneto-friulani sono stati soggetti negli ultimi decenni a profonde modificazioni morfologiche, indicative di una condizione d'instabilità, ossia di un'alterazione dei fattori che controllano la dinamica di un corso d'acqua (nel caso specifico, del regime delle portate solide). tali modificazioni, che hanno rilevanti effetti sulla stabilità delle opere in alveo, sulle acque sotterranee, sulla propagazione delle piene e sull'ecologia dell'ambiente fluviale e ripariale (bravard et al., 1999), sono state analizzate già a partire dalla fine degli anni '70 del secolo scorso (castiglioni & pellegrini, 1981), ma solo negli anni più recenti sono state oggetto di un significativo numero di studi (su r i a n, 1999, 2003; 2006; surian et al., 2005; surian & cisotto, 2007; da canal et al, 2007; surian et al., 2007). ciò che è emerso dagli studi finora svolti, che generalmente si riferiscono a singoli corsi d'acqua, è una rapida evoluzione degli alvei contraddistinta da processi di restringimento ed incisione. in particolare per quanto riguarda la larghezza degli alvei è stata osservata una intensa fase di restringimento, iniziata negli anni '50 del xx sec., a cui è seguita generalmente una fase di allargamento (surian & cisotto, 2007; da canal et al., 2007). queste variazioni di larghezza sono generalmente associate ad un'incisione, nella fase di restringimento, e ad una aggradazione dell'alveo, nella fase di allargamento. va sottolineato che il binomio “allargamento/aggradazione”, frequente nella fase più recente (ultimi 15-20 anni), non può comunque essere considerato una regola dei casi esaminati (su r i a n & ci s o t t o, 2007). questi aggiustamenti degli alvei, che in molti tratti hanno anche comportato una sostanziale modificazione della morfologia, con trasformazione dell 'a lveo da braided a canale singolo, sono imputabili essenzialmente ad una serie di interventi antropici. il prelievo di sedimenti e la costruzione di opere di difesa in alveo hanno avuto un ruolo determinante in molti corsi d'acqua, ma in alcuni casi altri interventi (ad esempio la costruzione di dighe) hanno contribuito ad alterare la dinamica fluviale. il presente lavoro si basa sulle ricerche svolte negli ultimi anni, in particolare nell'ambito di un progetto nazionale (prin 2005 “dinamica recente ed attuale di alvei fluviali in italia centro-settentrionale: tendenze evolutive, cause ed implicazioni applicative”). le analisi si sono basate su metodi ormai consolidati in quest'ambito di ricerca (analisi della cartografia storica e delle foto aeree tramite gis, confronto di rilievi topografici, rilievo geomorfologico dell'alveo). le ricerche hanno consentito da una parte di affinare le conoscenze relativamente ad alcuni corsi d'acqua che già in precedenza erano stati oggetto di studio (brenta, piave e tagliamento), ma anche di considerare altri corsi d'acqua (cellina e torre), al fine di disporre di una casistica più ampia per la regione in esame. obiettivo del lavoro è quindi quello di presentare lo stato attuale delle conoscenze su cinque dei principali corsi d'acqua venetofriulani, ma soprattutto quello di confrontare le tendenze evolutive ed i fattori che hanno determinato la dinamica degli alvei negli ultimi 200 anni. tale confronto ha lo scopo di fornire un contributo nella definizione di un modello di evoluzione degli alvei italiani (surian & rinald i, 2003 e 2004), nell'individuazione più precisa delle cause che hanno determinato le modificazioni degli alvei e nella comprensione degli aggiustamenti morfologici più recenti (ultimi 15-20 anni). 2. inquadramento dei corsi d'acqua analizzati i corsi d'acqua esaminati (fiume brenta, fiume piave, torrente cellina, fiume tagliamento e torrente torre) hanno origine nelle alpi orientali e sfociano nel mar adriatico a nord della laguna di venezia (ad eccezione del fiume brenta che sfocia a sud) (fig. 1). i relativi bacini idrografici hanno dimensioni variabili tra 446 km2 (cellina) e 3899 km2 (piave): quelli di minore dimensione (cellina e torre) si sviluppano nella regione prealpina, mentre quel li più estesi (brenta, piave e tagliamento) comprendono anche la regione alpina in senso stretto. le rocce più diffuse in questi bacini sono quelle sedimentarie e, fra queste, calcari e dolomie. l'energia del rilievo, valutata come differenza fra la fig. 1 inquadramento geografico dei corsi d'acqua analizzati, con evidenziati i tratti di studio. general setting of the selected streams, showing the study reaches. quota più alta e la quota più bassa (sezione di chiusura) nel bacino, varia tra 1679 m (torre) e 3162 m (piave) (tab. 1). le precipitazioni medie annue sono dell'ordine di 1300-1400 mm nei bacini del piave e del brenta, mentre decisamente più elevate in quelli del cellina (1770 mm), del tagliamento (2150 mm) e del torre (2280 mm). questi ultimi tre valori riflettono l'elevata piovosità di questo settore delle alpi, ma anche il fatto che la fascia prealpina registra precipitazioni maggiori rispetto alle zone più interne della catena. il regime molto variabile dei deflussi, ulteriormente accentuato negli ultimi decenni da importanti regolazioni (dighe, traverse, ecc.), risulta evidente dall'analisi dei rapporti fra le portate massime di piena e le portate medie annue. tali rapporti assumono infatti valori elevati, ad esempio pari a 42,6 nel caso del fiume tagliamento. come si evince dalla tab. 2, che riporta alcuni dati morfologici, sedimentologici ed idraulici, i tratti esaminati hanno caratteristiche molto simili. la porzione più a monte dei tratti è caratterizzata da una morfologia braided o transizionale (wandering), mentre le porzioni più a valle generalmente da una morfologia sinuoso/meandriforme (tab. 2). si tratta sempre di alvei ghiaiosi, con sponde non coesive, ossia costituite principalmente da ghiaia, nei tratti b r a i d e d/transizionali, e composite, nei tratti sinuoso/meandriformi. la pendenza degli alvei è generalmente compresa tra 0,3 % e 0,6 %, ad eccezione di quella del cellina che è pari a 1,2 %. ad eccezione del tratto montano del piave (vallone bellunese), i tratti esaminati hanno come limite superio281variazioni morfologiche degli alvei ... re la chiusura del bacino montano e si estendono nell'alta pianura ed in parte della bassa pianura. solo il cellina ed il torre, che confluiscono rispettivamente nel meduna (a sua volta affluente del livenza) e nell'isonzo, sono stati esaminati nei loro tratti terminali, mentre tali tratti non sono stati considerati nel caso del brenta, piave e tagliamento in quanto diffusamente canalizzati e quindi meno significativi per uno studio degli aggiustamenti dell'alveo. i tratti di studio sono relativamente estesi, da un minimo di 10 km (cellina) ad un massimo di 49 km (tagliamento). 3. impatto antropico sui sistemi fluviali i corsi d'acqua in esame sono stati interessati da numerosi interventi antropici che possono aver condizionato la loro dinamica (tab. 3). per alcuni di questi interventi è stato possibile reperire (da fonti bibliografiche, ricerche d'archivio e comunicazioni personali) o ottenere (attraverso l'analisi della cartografia storica e delle foto aeree) dati sufficientemente precisi per quantificarne l'entità e la loro collocazione temporale, mentre per altri interventi sono rimaste delle lacune. un primo aspetto rilevante è comunque il fatto che le singole tipologie d'intervento (prelievo di sedimenti, costruzione di dighe, costruzione di opere di difesa, ecc.) hanno una collocazione temporale molto simile nei cinque corsi d'acqua in esame (tab. 3). una possibile distinzione è quella fra gli interventi che hanno un'influenza diretta sulla dinamica dell'alveo tabella 1 caratteristiche idrologiche e fisiografiche dei corsi d'acqua esaminati. note: (-) dato non disponibile. hydrological and physiographic characteristics of the selected streams. notes: (-) data not available. corso d'acqua area bacino lunghezza energia del precipitazioni portata media massimo evento idrografico (km) rilievo del bacino medie annua di piena (km2) (m) (mm/anno) (m3 s-1) (m3 s-1) brenta 1567 174 3079 1390 71 2400 piave 3899 222 3162 1330 132 5300 cellina 446 58 2401 1770 950 tagliamento 2580 178 2696 2150 109 4650 torre 1105 69 1679 2280 tabella 2 caratteristiche morfologiche, sedimentologiche ed idrauliche dei tratti di studio. note: (-) dato non disponibile. morphological, sedimentological and hydraulic characteristics of the selected reaches. notes: (-) data not available. corso d'acqua lunghezza del configurazione dell'alveo pendenza d50 tipo q1.5 (m3 s-1) tratto di studio (b: braided; alveo sedimenti del di sponde (km) t: transizionale; s: sinuoso(in %) fondo (mm) meandriforme) brenta 23 b/t/s 0,2-0,5 26-140 non coesive; 390 composite piave 32 b/t 0,3-0,6 20-48 non coesive 510 (tratto montano) piave 22 b/t/s 0,2-0,5 18-28 non coesive; 700-750 (tratto pianura) composite cellina 10 b/t 1,2 non coesive 105 tagliamento 49 b/t/s 0,1-0,4 20-49 non coesive; 900-1000 composite torre 44 b/t/s 0,3-0,6 non coesive; composite e quelli che agendo a scala di bacino, ad esempio sugli affluenti o sui versanti, hanno un'influenza indiretta, ma talvolta ugualmente rilevante, sulla dinamica di un determinato corso d'acqua. fra gli interventi “diretti” i più rilevanti sono senz'altro la costruzione delle opere di difesa ed il prelievo di sedimenti. opere di difesa sono state realizzate in tutti i tratti esaminati, generalmente a partire dal xix sec. inizialmente si è trattato soprattutto di opere longitudinali (argini), mentre nel corso del xx sec. sono state realizzate anche numerose strutture trasversali (pennelli). il prelievo di sedimenti in alveo è stato invece un fenomeno meno distribuito nel tempo (tab. 3): un prelievo molto intenso, soprattutto legato ad un forte sviluppo economico, ha avuto luogo tra gli anni '50 e gli anni '80 del xx sec. seppure con qualche piccola differenza l'attività di prelievo si è concentrata in un periodo relativamente breve (20-25 anni): ad esempio dagli anni '50 ai primi anni '80 nel brenta, mentre dai primi anni '70 ai pr imi anni '90 nel tagliamento. i volumi di sedimenti rimossi dagli alvei sono stati dell'ordine di vari milioni di m3. facendo riferimento ai dati ufficiali, che sono certamente una sottostima dei valori reali, sono stati valutati i seguenti volumi: 8,6 milioni di m3, per il brenta tra il 1953 ed il 1977 ( su r i a n & ci s o t t o, 2007); 24 mil ioni di m3, per il tagliamento tra il 1970 ed il 1991 (su r i a n, 2006); 15 milioni di m3, per il torre fra gli anni '50 e gli anni '70 (surian et al., 2007). si tratta di volumi considerevoli se si considera che il trasporto solido tota le nel tagliamento, probabilmente il corso d'acqua con trasporto più elevato fra quelli esaminati, è stato stimato pari 1,3 milioni di m3 ( autorità di ba c i n o, 1998), ma soprattutto se si considera che i sedimenti ghiaiosi asportati corrispondono al trasporto solido al fondo, e quindi solo ad un 10-20 % (surian & cisotto, 2007) del trasporto totale. negli ultimi 20-25 anni il prelievo non si è esaurito, ma assestato su volumi di sedimenti decisamente inferiori a quelli dei decenni precedenti. gli interventi “indiretti” includono la costruzione di dighe, le sistemazioni idraulico-forestali nel bacino montano e il rimboschimento dei versanti (tab. 3). la maggior parte delle dighe sono state costruite negli anni '50 del xx sec., anche se alcuni sbarramenti, generalmente di minori dimensioni, erano già stati realizzati nella prima metà del secolo (ad esempio nei bacini del brenta, piave e cellina). gli effetti delle dighe sui tratti d'alveo esaminati sono differenti in relazione innanzitutto alla distanza fra lo sbarramento ed il tratto stesso (wi l l i a m s & wo l m a n, 1984), inoltre all'area a monte dello sbarramento (percentuale del bacino idrografico sottesa dalla diga). il tagliamento ed il cellina risultano in tal senso due casi estremi: nel primo caso l'area sottesa dalle dighe è decisamente modesta (3%) rispetto all'intero bacino idrografico e non prossima al tratto di studio, mentre nel cellina la diga sottende una considerevole porzione del bacino (87 %) ed è situata 6 km a monte del tratto esaminato. per le sistemazioni idraulico-forestali nei bacini montani non si dispone attualmente di un'accurata documentazione, ma si tratta in ogni caso di una tipologia d'intervento che, in maniera più o meno diffusa, ha interessato tutti i corsi d'acqua in esame, soprattutto nel corso del xx sec. infine per quanto riguarda la copertura forestale è assodato un processo di espansione nelle regioni in esame (veneto e friuli venezia giulia), così come a scala nazionale. il processo, iniziato da alcuni decenni e tuttora in atto, è stato quantificato solo per piccole aree (lamedica et al., 2007), per cui risulta difficile valutarne l'effetto alla scala dei bacini idrografici qui esaminati. comunque che per alcuni bacini, ad esempio quello del piave, il processo di riforestazione dovrebbe essere cominciato già dai primi decenni del xx sec. (vo l l o, 1942; agnoletti, 1993). l'aspetto rilevante che emerge dall'analisi dei principali interventi antropici è che tutti hanno o possono aver influito sul regime del trasporto solido dei corsi d'acqua. in particolare, seppure con intensità e tempi differenti, il prelievo di sedimenti, la costruzione delle dighe, le sistemazioni idraulico-forestali e la riforestazione nei bacini montani hanno determinato una riduzione della produzione di sedimenti a scala di bacino e del trasporto solido in alveo. generalmente invece la regolazione dei deflussi non ha avuto effetti significativi sulle portate formative, ossia sulle portate rilevanti in termini di trasporto solido al fondo e di dinamica degli alvei (su r i a n, 2006; su r i a n & ci s o t t o, 2007). solo nel caso del cellina è stato riscontrato un effetto in tal senso: a seguito della costruzione della diga di ponte antoi (1954) le piene con tempi di ritorno di 1,5 e 5 anni sono diminuite, rispettivamente, da 165 m3/s a 105 m3/s e da 480 m3/s a 260 m3/s (mussio, 2007). 4. materiali e metodi 4.1 cartografia storica e foto aeree l'impiego della cartografia e delle fotografie aeree ha consentito di analizzare l'evoluzione degli alvei negli ultimi 200 anni. per quanto riguarda il xix sec. è stata utilizzata la carta del ducato di venezia (anche nota come carta del von zach) del 1805 (scala 1:26.000), la carta del regno lombardo veneto del 1833 (scala 282 tabella 3 interventi antropici nei corsi d'acqua esaminati. nota: per anni '50, '60, ecc., si intende del xx sec. human interventions in the selected streams. note: “anni '50, '60, etc.” refers to the 20th century. corso d'acqua intenso prelievo di costruzione di argini ed realizzazione delle area del bacino a monte sedimenti in alveo altre opere di difesa dighe delle dighe in alveo (%) brenta anni '50-'80 xix-xx sec. 1954 40 piave anni '60-'80 xv-xx sec. anni '30-'50 54 cellina anni '70-'80 xix-xx sec. 1954 87 tagliamento anni '70-'80 xix-xx sec. anni '50 3 torre anni '60-'70 xix-xx sec. n. surian et al. 1:86.400) e le prime edizioni delle tavolette i.g.m. realizzate alla fine del secolo (scala 1:25.000). per il periodo successivo sono state utilizzate le varie edizioni delle tavolette i.g.m. (prima metà del secolo) e le foto aeree (dagli anni '50 del xx sec. ad oggi) (tab. 4). in qualche caso sono state anche impiegate le carte tecniche regionali (scala 1:5.000 o 1:10.000) in sostituzione delle foto aeree degli anni '80. per ognuno dei corsi d'acqua si è quindi potuto disporre complessivamente da un minimo di 9 ad un massimo di 12 documenti (cartografia + foto aeree). l'analisi delle carte e delle foto aeree, realizzata in ambiente gis, si è concentrata soprattutto sulla misura della larghezza dell'alveo. tale parametro può essere valutato sia facendo riferimento all'intera area compresa fra le sponde, sia escludendo le isole, ossia quelle porzioni dell'alveo non attive in termini di trasporto solido al fondo e pertanto assimilabili ad una piana inondabile (surian, 2006). nei risultati di seguito illustrati la larghezza a cui ci si riferisce è quella dell'”alveo attivo” (“alveo totale” “isole”). a differenza di precedenti studi ( su r i a n, 1999; wi n t e r b o t t o m, 2000; li e b a u l t & pi e g a y, 2001), nei quali la larghezza è stata stimata come media di una serie di misure puntuali, ossia in corrispondenza di sezioni trasversali con una determinata equidistanza, la larghezza media di un tratto è stata valutata dal rapporto “area alveo”/”lunghezza tratto”. in tal modo si è eliminata una possibile fonte di errore che derivava inevitabilmente dalla stima della larghezza media a partire da un numero discreto di misure. l'errore associato alle misure di larghezza deriva dalla fase di georeferenziazione delle immagini (cartografia e foto aeree) e dalla successiva fase di individuazione e digitalizzazione delle sponde dell'alveo. sulla base di una serie di analisi preliminari e di quanto riscontrato in precedenti ricerche (gurnell, 1997; hughes et al., 2006) si è valutato che le misure eseguite sui documenti cartografici possono essere affette da errori massimi di 1520 m, mentre quelle su foto aeree da errori massimi di 5-6 m. questi valori, seppure indicativi, consentono di valutare il significato delle variazioni di larghezza che sono state osservate. 4.2 rilievi topografici il numero limitato di rilievi topografici disponibili non ha consentito una ricostruzione dettagliata delle variazioni altimetriche così come è stato invece possibile per le variazioni di larghezza dell'alveo. da un punto di vista temporale, solo per il piave e per il brenta i primi rilievi si riferiscono ai primi decenni del xx sec. (r ispettivamente 1929 e 1932), mentre per i l tagliamento e il torre risalgono agli anni '70 (rispettivamente 1970 e 1979) (tab. 4). in pratica, il numero di rilievi disponibili ha consentito delle ricostruzioni temporali di un certo significato solo nel caso del brenta e del tagliamento. i rilievi sono stati comunque di indubbia importanza per stimare l'entità delle variazioni avvenute, seppure limitate al periodo più recente di quello complessivo considerato nel presente studio. 4.3 rilevamento geomorfologico dell'alveo il rilievo geomorfologico sul terreno è stato finalizzato da un lato ad una caratterizzazione complessiva dell'alveo (caratteristiche morfologiche, sedimentarie e idrauliche, vegetazione, opere antropiche), dall'altro alla valutazione delle tendenze evolutive, nel medio e breve termine, dell'alveo. tale rilievo è stato svolto in modo sistematico, utilizzando le schede messe a punto nell'ambito del progetto di ricerca citato in precedenza ( ri n a l d i, 2008), sul piave e, solo parzialmente, sul tagliamento. l'obiettivo principale dei rilievi è stato quello di acquisire informazioni sull'evoluzione altimetrica, sia attraverso la misura di dislivelli tra superfici omologhe che il riconoscimento di una serie di evidenze morfologiche e sedimentologiche. 5. risultati 5.1 variazioni di larghezza degli alvei l'analisi della cartografia storica e delle foto aeree tramite gis ha permesso di ricostruire le variazioni di larghezza degli alvei negli ultimi 200 anni. i risultati di tale analisi sono riportati in fig. 2 e nelle tab. 5 e 6. si può innanzitutto osservare che alcuni dei tratti di studio sono stati suddivisi a loro volta in sotto-tratti in quanto o molto estesi (es. tagliamento) o non del tutto omogenei nella loro evoluzione (es. brenta) (fig. 2). per un confronto più immediato tra i diversi corsi d'acqua si è ritenuto opportuno esprimere la larghezza in termini adimensionali piuttosto che in termini assoluti. pertanto nei grafici di fig. 2 la larghezza è espressa come “l/lmax”, dove l rappresenta la larghezza misurata nei diversi anni e lmax la larghezza massima osservata nel periodo in esame. un primo aspetto che si può rilevare è la forte analogia di comportamento dei diversi tratti esaminati. nel complesso i tratti mostrano infatti un marcato restringimento dell'alveo e solo a partire dagli anni '80283 tabella 4 numero di documenti cartografici, di foto aeree e rilievi topografici utilizzati nel presente studio e relativi intervalli di tempo. number of maps, aerial photographs and topographic surveys that have been used and periods of time covered by such data. corso d'acqua numero di documenti numero di rilievi aerei numero di rilievi topografici cartografici utilizzati utilizzati utilizzati brenta 4 (1805-1960) 5 (1955-2003) 7 (1932-1997) piave (tratto montano) 3 (1805-1926) 6 (1960-2003) 2 (1929-2003) piave (tratto pianura) 5 (1805-1982) 4 (1991-2003) 4 (1929-2002) cellina 7 (1805-1986) 3 (1997-2002) tagliamento 4 (1805-1927) 8 (1954-2007) 5 (1970-2003) torre 7 (1805-1989) 2 (1999-2004) 2 (1979-2003) variazioni morfologiche degli alvei ... 284 fig. 2 variazione della larghezza dell'alveo durante gli ultimi 200 anni nei cinque corsi d'acqua in esame (a-e); la larghezza è espressa come “l/lmax”, dove l rappresenta la larghezza misurata nei diversi anni e lmax la larghezza massima nel periodo in considerazione. un'analisi complessiva dei cinque corsi d'acqua e dei relativi sotto-tratti è riporta nell'ultimo grafico (f), nel quale sono indicati anche i parametri statistici delle regressioni ottenute per ciascuna fase di evoluzione. changes in channel width during the last 200 years in the selected streams (a-e); the width is represented by the ratio “l/lmax”, where l is the width measured in the different years and lmax the maximum width in the study period. an overall analysis of the selected streams is shown in the last graph (f), which reports the statistics of the linear regressions for each evolutionary phase. n. surian et al. '90 un processo di allargamento (fig. 2). nonostante qualche tratto si discosti in parte da tale evoluzione, si è ritenuta significativa un'analisi statistica dell'insieme dei dati, ossia di tutti i tratti e sotto-tratti, al fine di individuare le fasi aggiustamento verificatesi negli ultimi 200 anni (fig. 2f). l'analisi ha evidenziato la presenza di quattro fasi principali: i) una prima fase, corrispondente al xix sec., caratterizzata da una sostanziale stabilità della larghezza; ii) una seconda fase (prima metà del xx sec.) nella quale si verifica una modesta riduzione della larghezza; iii) una terza fase (anni '50 anni '80/'90) interessata da un marcato processo di restringimento dell'alveo; iv) infine una quarta fase (ultimi 1520 anni) nella quale prevale un processo di allargamento dell'alveo. un esame più specifico di queste fasi di aggiustamento dell'alveo viene di seguito riportato. la condizione di massimo restringimento si è quindi verificata generalmente negli anni '80/'90 del xx sec., quando la riduzione della larghezza è stata dell'ordine del 50-70 % rispetto al valore iniziale (prima metà del xix sec.) (tab. 5). il minimo restringimento è stato riscontrato per il tratto intermedio del tagliamento, da 980 m a 500 m (pari al 49 %), mentre i valori massimi per il tratto di pianura del piave e per il torre, rispettivamente da 960 m a 260 m e da 560 m a 150 m (entrambi pari al 73 %). passando ad un esame delle fasi che hanno portato a questa situazione di massimo restringimento degli alvei si rileva una prima fase, corrispondente all'intero xix sec., nella quale dei 9 tratti in esame, 5 sono stati interessati da restringimento, variabile tra il 4 % ed 20 %, e 4 da allargamento, variabile tra il 6 % ed il 22 % (tab. 5). nel complesso si può quindi osservare l'assenza di un restringimento generalizzato degli alvei e variazioni comunque contenute, sia nel caso di restringimento che di allargamento dell'alveo. nella seconda fase (prima metà del xx sec.) si riscontra già un restringimento generalizzato: in 8 tratti si ha una riduzione della larghezza, con valori compresi tra il 9 % (tratto inferiore del tagliamento) e il 42 % (piave nel vallone bellunese), mentre solo l'alveo del cellina risulta sostanzialmente stabile (allargamento del 3 %). il restringimento più consistente si verifica nella terza fase (anni '50 anni '80/'90) nella quale tutti i tratti subiscono una riduzione della larghezza dell'alveo, variabile tra il 25 % ed il 59 %. l'entità del restringimento di questa terza fase è ben espresso non solo dai valori percentuali rispetto alle larghezze originarie, ma anche dai tassi di restringimento. in questa fase il tasso di restringimento è infatti in media di 8 m/anno (con variazioni tra 2,5 e 15,5 m/anno), a differenza della fase precedente nella quale era in media di 2,5 m/anno (con variazioni tra 0,6 e 5,4 m/anno). negli ultimi anni del periodo esaminato tutti i corsi d'acqua, ad eccezione del torre, mostrano un'inversione di tendenza, ossia un netto processo di allargamento o, quantomeno, un'interruzione del processo di restringimento (tab. 6). in alcuni casi questa nuova fase ha inizio già negli anni '80, ad esempio nel tratto superiore del brenta e nel tratto intermedio del tagliamento, ma nella maggior parte dei casi sembra avere inizio negli anni '90. naturalmente rimangono delle incertezze nella definizione temporale di questa inversione di tendenza, incertezze che potrebbero essere risolte solo in quei casi dove ulteriori foto aeree si rendessero disponibili. in termini sia assoluti (allargamento massimo di 153 m del piave in pianura) che percentuali (aumento della larghezza del 20 % del brenta nel tratto superiore) questa fase è decisamente meno rilevante di quella precedente. ma analizzando i tassi, e quindi tenendo conto della durata minore di questa fase, si può osservare che l'intensità dell'allargamento è comunque significativa. il tasso medio di allargamento dei 7 tratti 285 tabella 5 variazioni di larghezza nel corso delle prime tre fasi (per l'individuazione delle fasi si veda sia la fig. 2 sia il testo); per ogni fase la variazione è espressa in termini assoluti (m), in percentuale (%), considerando come valore di riferimento la larghezza all'inizio del xix sec., e come tasso di variazione medio (m/anno). width changes during the first three phases of channel adjustments (for definition of the different phases see fig. 2 and the main text); for each phase width changes are reported in metres (m), in percent (%), taking the width at the beginning of the 19th century as reference, and as average rate of change (m/year). i fase ii fase iii fase variazione totale corso d'acqua (xix sec.) (prima metà xx sec.) (anni '50 anni '80/'90) nelle 3 fasi (m) % (m/anno) (m) % (m/anno) (m) % (m/anno) (m) % tratto 49 11% 0,6 -123 -27% -1,9 -200 -44% -7,7 -275 -60% brenta superiore tratto inferiore -16 -4% -0,2 -83 -20% -1,3 -193 -46% -4,4 -292 -69% vallone piave bellun. 40 6% 0,5 -272 -42% -3,9 -160 -25% -5,3 -392 -64% pianura -130 -14% -1,5 -132 -14% -2,1 -437 -46% -11,8 -699 -73% cellina -89 -11% -1,0 25 3% 0,5 -310 -38% -7,8 -374 -55% tratto superiore -224 -11% -2,6 -295 -15% -4,7 -606 -31% -15,5 -1.125 -60% tagliamento tratto intermed. 273 22% 3,2 -341 -27% -5,4 -415 -33% -12,2 -483 -49% tratto inferiore 29 7% 0,3 -41 -9% -0,6 -264 -59% -5,1 -275 -66% torre -110 -20% -1,9 -157 -28% -3,0 -142 -25% -2,5 -409 -73% variazioni morfologiche degli alvei ... 286 corso d'acqua prima fase seconda fase valore/stima metodo periodo valore/stima metodo periodo tratto super. -3 m +0,2 m brenta (-5 ÷ 0 m) st 1932-1984 (-0,3 ÷ +0,6m) st 1984-1997 tratto infer. -6 m (-8,5 m ÷ -4 m) st 1932-1984 sedimentazione st 1984-1997 piave vallone bell.se (-2 ÷ -1 m) rg sedimentazione rg pianura -2 m equilibrio/ (-3 ÷ -1 m) st + rg 1929-1978 sedimentazione rg tratto infer. -1,6 m (-3,9 ÷ 0,4 m) st 0 st -2.9 m 1970 1988 0.1 m 1988 2003 (-3.6 ÷ -2.4 m) rg (-0.6 ÷ 0.9 m) rg tagliamento tratto interm. -0,5 m (-1,5 ÷ 1,2 m) st 1970 1988 -0,9 m st 1988 2003 -1.7 m -0.2 m (-2.5 ÷ -1.2 m) rg (-0.5 ÷ 0.2 m) rg tratto super. -0,4 m (0,7 ÷ -1,7 m) st 1988 2001 torre -2 m pre-1979 -0,8 m (-5,0 m ÷ 0 m) (-3 m ÷ +2,6 m) st 1979 2003 tabella 6 variazioni di larghezza nella quarta fase (per l'individuazione delle fasi si veda sia la fig. 2 sia il testo); la variazione è espressa in termini assoluti (m), come tasso di variazione medio (m/anno), ed in percentuale (%), considerando come valore di riferimento sia la larghezza all'inizio del xix sec. sia la larghezza all'inizio della fase. si osservi che la fase ha estensione differente da tratto a tratto sia perché l'inversione di tendenza da restringimento ad allargamento non è stata contemporanea, sia per una disomogenea disponibilità delle foto aeree. il torre fa caso a sé, in quanto non si è verificata un'inversione di tendenza. note: “n.v.” indica nessuna variazione, ossia una variazione di larghezza inferiore all'errore associato alla misura. width changes in the fourth phase of adjustment (for definition of the different phases also see fig. 2 and the main text); width changes are reported in metres (m), as average rate of change (m/year), and in percent (%), taking both the width at the beginning of the 19th century and the width at the beginning of the phase itself as references. it is worth noting that the period of this phase is different from one reach to another, since widening has started at different times and air photos are not available with same details in the selected reaches. the case of the torre is completely different, since narrowing is still ongoing. notes: “n.v” means no change, since the width change is lower than measurement error. corso d'acqua iv fase periodo (m/anno) (m) % (1805) % (inizio fase) brenta tratto superiore 1981 2003 4,1 90 20% 49% tratto inferiore 1999 2003 8,0 32 8% 25% cellina 1997 2002 7,8 39 5% 11% piave vallone bellunese 1990 2003 8,5 111 17% 51% pianura 1991 2003 12,7 153 16% 59% tagliamento tratto superiore 1993 2007 1,9 26 1% 3% tratto intermedio 1988 2007 4,2 80 6% 16% tratto inferiore 1997 2007 n.v. torre 1999 2004 -4,3 -22 -4% -14% tabella 7 variazioni altimetriche degli alvei desunte dal confronto di sezioni topografiche (st) e da rilevamenti geomorfologici (rg) svolti nel 2007; per ogni tratto è indicato il valore medio (“-“ indica incisione, “+” sedimentazione) e tra parentesi i valori minimi e massimi. la prima fase corrisponde sostanzialmente alla terza fase e ad una parte della seconda fase definite per le variazioni di larghezza (tab. 5), mentre la seconda fase alla quarta fase definita per le variazioni di larghezza (tab. 6). i dati non sono attualmente disponibili per il cellina. bed-level changes from comparison of topographic surveys (st) and geomorphological surveys carried out in 2007 (rg); the average change (“-“ means incision, “+” means aggradation) and the minimum and maximum changes (between brackets) are reported for each reach. the first phase corresponds approximately to the third phase and to part of the second phase that were defined for channel width changes, while the second phase corresponds to the fourth phase defined for width changes. data is not available for the cellina torrent. (escludendo i l torre ed i l tratto infer iore del tagliamento) risulta infatti pari a 6,7 m/anno, mentre il tasso più elevato è quello del piave in pianura, pari a 12,7 m/anno. infine, oltre a ricordare che il torre si contraddistingue come unico corso d'acqua che continua a restringersi nella fase più recente, si fa notare come il tagliamento, a differenza del brenta e del piave, mostri un significativo allargamento solo nel tratto intermedio, mentre una sostanziale stabilità della larghezza negli altri due tratti (fig. 2 e tab. 6). n. surian et al. 5.2 variazioni altimetriche degli alvei inizialmente, in concomitanza con la seconda (prima metà del xx sec.) e, soprattutto, con la terza fase (anni '50 anni '80/'90) di variazione della larghezza dell'alveo, tutti i corsi d'acqua in esame sono stati soggetti ad un processo di abbassamento del fondo (incisione) (fig. 3 e tab. 7). l'incisione è stata più contenuta nei tratti più a monte, generalmente tra i 1 e 3 m, mentre è stata di notevole entità in alcuni tratti inferiori (ad esempio il brenta dove l'incisione è stata di 8,5 m). due esempi di variazione spaziale di questo processo d'incisione sono illustrati in fig. 3. nel caso del tagliamento si può notare chiaramente come il tratto inferiore, dove la morfologia dell'alveo è sinuoso-meandriforme, ha subito un'incisione maggiore rispetto al tratto più a monte caratterizzato da morfologia braided. nel piave (tratto montano nel vallone bellunese) si osserva invece un'alternanza di tratti con differente grado d'incisione: tale distribuzione spaziale dell'incisione è determinata, almeno in parte, dalla morfologia del fondovalle, ossia dalla presenza di tratti a diverso grado di confinamento. come esposto nel capitolo precedente, i dati a disposizione non consentono nella maggior parte dei casi una dettagliata ricostruzione dell'evoluzione altimetrica del fondo. sulla base delle sezioni topografiche e dei rilievi geomorfologici effettuati è comunque ipotizzabile che gran parte del processo d'incisione si sia verificato soprattutto tra gli anni '50 e gli anni '80 del xx sec. negli ultimi 15-20 anni, le variazioni altimetriche del fondo sono generalmente in netta discontinuità con il periodo precedente (fig. 3). ad eccezione del torre, dove è continuato un processo d'incisione, il confronto dei ril ievi topografici più recenti ed i rilievi geomorfologici hanno evidenziato che molti tratti sono attualmente in sedimentazione o, perlomeno, in equilibrio (figg. 3 e 4 e tab. 7). la sedimentazione, per quanto abbastanza problematica nella stima, è stata al massimo di 2 m. le evidenze morfologiche e sedimentologiche che hanno permesso di definire l'esistenza di un processo di sedimentazione in alveo sono state le seguenti: la presenza di barre più alte della piana inondabile (quota della sommità delle barre maggiore della quota delle ghiaie sulle sponde); la diffusa presenza di lobi di sedimentazione (fig. 4); sedimenti del fondo caratterizzati da corazzamento ed embriciatura lievi o assenti; forme di fondo scarse o assenti. un aspetto interessante, si veda ad esempio il piave in fig. 3, è la variazione spaziale della sedimentazione che generalmente aumenta da monte verso valle all'interno dei tratti esaminati. situaz ione analoga è stata r iscontrata lungo il brenta (surian & cisotto, 2007). quindi, in generale, i corsi d'acqua veneto-friulani sono stati caratterizzati inizialmente da una fase d'incisione, a cui è seguita una fase di sedimentazione o, comunque, di maggiore stabilità altimetrica. attualmente gli alvei, nella maggior parte dei tratti esaminati, risultano incisi in quanto la fase d'incisione è stata più prolungata e, generalmente, più intensa di quella di 287 fig. 3 variazioni altimetriche del fondo nel medio (a) e nel breve termine (b) desunte dal rilevamento geomorfologico: il tratto intermedio ed inferiore del tagliamento è stato analizzato in 12 sotto-tratti, mentre quello del piave nel vallone bellunese in 13 sotto-tratti. legenda: 1: incisione limitata; 2: incisione moderata; 3: incisione intensa; 4: equilibrio/incisione; 5: equilibrio; 6: equilibrio/sedimentazione; 7: sedimentazione; n.d.: dato non disponibile. bed-level changes in the medium (a) and short (b) periods derived from the geomorphological survey: the medium and lower reaches of the tagliamento were investigated in 12 sub-reaches, whereas the reach of the piave in the vallone bellunese in 13 sub-reaches. legend: 1: incision; 2: moderate incision; 3: intense incision; 4: equilibrium/incision; 5: equilibrium; 6: equilibrium/sedimentation; 7: sedimentation; n.d.: data not available. variazioni morfologiche degli alvei ... sedimentazione. va comunque segnalato che localmente, ad esempio in alcuni tratti del piave nel vallone bellunese, la sedimentazione recente dell'alveo è stata di entità maggiore rispetto all'incisione del periodo precedente. 6. discussione da un punto di vista metodologico emergono delle differenze sostanziali fra l'analisi delle variazioni planimetriche (larghezza) e di quelle altimetriche degli alvei. la ricca documentazione disponibile (cartografia storica e foto aeree) e l'impiego dei gis hanno consentito ricostruzioni molto affidabili della larghezza, anche perché gli errori associati a questo tipo di analisi risultano modesti se confrontati con le variazioni misurate. al contrario è risultata più problematica la ricostruzione delle variazioni altimetriche. seppure i rilievi topografici ed il rilevamento geomorfologico hanno consentito di riconoscere e quantificare due principali fasi di aggiustamento (incisione seguita da sedimentazione), in pochi casi è stato possibile ottenere dettagliate ricostruzioni di tali fasi. in tal senso pare opportuno sottolineare l'importanza di continuare ad applicare ed affinare in futuro approcci di rilevamento come quello proposto da rinaldi (2008). l'entità delle variazioni misurate è senz'altro notevole: basti pensare che in alcuni tratti tali variazioni hanno comportato una radicale trasformazione della morfologia dell'alveo, ad esempio da braided a sinuoso. d'altra parte, anche considerando i valori massimi di restringimento (73 %) e d'incisone (8,5 m), non si può affermare che i fiumi veneto-friulani rappresentino dei casi unici sia in un contesto nazionale (surian & rinaldi, 2003 e 2004; ri n a l d i et al., 2005) che in riferimento a corsi d'acqua europei o extra-europei (williams, 1978; williams & wolman, 1984; liebault & piegay, 2002). per quanto riguarda le variazioni altimetriche è però opportuno sottolineare che abbassamenti del fondo di 1-2 m in alvei larghi alcune centinaia di metri sono la conseguenza di una drastica variazione nel regime del trasporto solido (riduzione nel trasporto al fondo dell'ordine di alcuni milioni di m3) e quindi l'evidenza di una significativa condizione d'instabilità dell'alveo. i risultati di questo studio, soprattutto quelli relati288 fig. 4 i lobi di sedimentazione, quando molto diffusi in un determinato tratto, sono stati tra gli indicatori più utilizzati per definire le tendenza evolutive nel breve termine (se supportati da altre evidenze possono indicare la presenza di una fase di sedimentazione). la foto aerea e le due foto di terreno, con indicate le fronti di grandi lobi di sedimentazione, sono relative al fiume tagliamento e sono state scattate rispettivamente nell'aprile e nel maggio del 2007. the sediment lobes are the evidence that has been more frequently used during the geomorphological survey to assess the evolutionary trend in the short period (if there is other evidence a sedimentation phase may eventually be inferred). the air photo and the two ground photos, where the front of large sediment lobes have been pointed out, show a reach of the tagliamento river and they were taken in april 2007 and may 2007, respectively. n. surian et al. vi alla larghezza degli alvei, consentono un affinamento dei modelli finora proposti per l'evoluzione recente ed attuale dei corsi d'acqua italiani. ad un primo schema evolutivo che prevedeva una sola fase di aggiustamento ( su r i a n & ri n a l d i, 2003), era seguito, relativamente a corsi d'acqua b r a i d e d, un modello che includeva tre fasi evolutive (su r i a n & ri n a l d i, 2004), in particolare una prima fase di moderato restringimento ed incisione, una seconda fase di forte restringimento ed incisione ed una terza fase caratterizzata da allargamento e da una certa stabilità altimetrica. rispetto a questo ultimo modello l'evoluzione dei fiumi veneto-friulani suggerisce alcune novità per quanto riguarda la prima e l'ultima parte del periodo in esame. nel corso del xix sec. gli alvei mostrano nel complesso delle variazioni contenute e di diverso tipo (sia allargamento che restringimento), non tali da definire condizioni di instabilità. pertanto, rispetto al modello di su r i a n & ri n a l d i (2004), risulterebbe l'esistenza di un'ulteriore fase, la prima, priva di significativi aggiustamenti. per quanto riguarda la fase più recente, i risultati confermano che l'allargamento degli alvei è il processo dominante, ma indicano anche che esistono dei casi che si discostano da tale tendenza (il caso del torre) e che l'allargamento è frequentemente associato a processi di sedimentazione (fig. 3 e tab. 7). l'entità delle variazioni morfologiche e la loro cronologia suggeriscono un forte legame con i vari interventi antropici descritti in precedenza. per quanto riguarda il primo aspetto, raramente in condizioni naturali i corsi d'acqua subiscono variazioni come quelle qui analizzate in periodi così brevi (ru m s b y & ma c k l i n, 1994). l'altro aspetto significativo è la stretta correlazione temporale fra determinati interventi e le modificazioni degli alvei. soprattutto per quanto riguarda il prelievo di sedimenti si può notare un'immediata risposta degli alvei e quindi “tempi di reazione” molto brevi. sulla base delle variazioni osservate e dei dati relativi agli interventi antropici si può quindi tentare di associare ad ogni fase evolutiva degli alvei i principali fattori di controllo. prima fase (xix sec.): in questa fase l'intervento antropico più rilevante è stato la costruzione degli argini; ciò senza particolari effetti sulla morfologia degli alvei, probabilmente in relazione al fatto che gli argini sono stati generalmente posizionati in modo tale da mantenere uno spazio sufficientemente ampio di divagazione. seconda fase (prima metà del xx sec.): in questa fase di moderato aggiustamento (restringimento e probabile incisione) gli interventi più significativi sembrano essere le opere di difesa trasversali (pennelli), le sistemazioni idraulico-forestali e la riforestazione. terza fase (anni '50 anni '80/'90): questa fase caratterizzata da intense modificazioni è determinata principalmente dal prelievo di sedimenti in alveo; questo intervento ha un effetto immediato sulla dinamica dei tratti esaminati e probabilmente prevale su altri tipi di intervento quali la costruzione delle dighe, le sistemazioni idraulico-forestali e la riforestazione; anche le opere di difesa, come nella fase precedente, continuano ad avere un ruolo significativo. quarta fase (ultimi 15-20 anni): rispetto alla fase precedente la variazione più rilevante è la marcata riduzione nel prelievo di sedimenti; questa variazione sembra essere la causa più plausibile dell'inversione di tendenza evolutiva osservata nella maggior parte dei tratti in esame. 7. conclusioni 1. negli ultimi 200 anni gli alvei dei principali corsi d'acqua veneto-fr iulani (brenta, piave, cel lina, tagliamento e torre) hanno subito notevoli modificazioni. gli alvei sono stati interessati da processi di restringimento (fino al 73 % nel caso del piave in pianura e del torre) e d'incisione (fino a 8,5 m nel tratto inferiore del brenta) che solo in minima parte sono stati bilanciati da un'inversione di tendenza (allargamento e sedimentazione) degli ultimi 15-20 anni. un aspetto che emerge dal confronto di questi corsi d'acqua è un comportamento molto simile sia per l'intensità che per lo sviluppo temporale delle variazioni morfologiche. 2. i risultati di queste ricerche confermano nel complesso l'applicabilità dei modelli concettuali esistenti (surian & rinaldi, 2003 e 2004) ma suggeriscono anche che alcuni aspetti dovrebbero essere rivisti, naturalmente sulla base di una casistica più ampia di quella qui considerata. innanzitutto non risulta esserci una fase di instabilità degli alvei nel corso del xix sec., in quanto questi sono soggetti ad una prima fase di restringimento e, forse, d'incisione solo a partire dall'inizio del secolo scorso. in secondo luogo inizia a definirsi in modo più preciso la fase più recente di evoluzione (ultimi 15-20 anni): dal punto di vista planimetrico si conferma che il processo di allargamento è dominante, anche se non esclusivo, mentre per quanto riguarda l'altimetria degli alvei le situazioni più frequenti sono quelle di equilibrio e di sedimentazione. 3. le cause delle forti variazioni morfologiche degli alvei sono una serie di interventi antropici che con tempi ed intensità differenti hanno avuto effetti diretti o indiretti sulla dinamica fluviale. il prelievo di sedimenti e le opere di difesa in alveo, in ordine d'importanza, hanno avuto un ruolo determinante. meno evidente, almeno per i tratti d'alveo qui esaminati, risulta essere il ruolo esercitato dalle dighe (ad eccezione del cellina), dalle sistemazioni idraulico-forestali e dalla riforestazione. come già evidenziato in studi precedenti (surian & rinaldi, 2004; surian, 2006; surian & cisotto, 2007), si conferma che i vari interventi antropici hanno radicalmente alterato il regime del trasporto solido, mentre solo nel caso del cellina è stata riscontrata una variazione significativa delle portate formative. ringraziamenti ricerca realizzata nell'ambito del progetto prin 2005 “dinamica recente ed attuale di alvei fluviali in italia centro-settentrionale: tendenze evolutive, cause ed implicazioni applicative” (coordinatore nazionale: n. surian). si ringraziano paolo castello, marco da canal, lisa mussio, daniela pasqualini, matteo zanatta e francesco zignol per aver contribuito, attraverso le loro tesi di laurea, alla conoscenza di alcuni dei casi di studio qui presentati. ringraziamo inoltre doriano castaldini e susanna perego per i loro commenti e suggerimenti che hanno permesso di migliorare la stesura definitiva di questo articolo. 289variazioni morfologiche degli alvei ... bibliografia agnoletti m. (1993) gestione del bosco e segagione del legname nell'alta valle del piave in: caniato g. (a cura di), la via del fiume. dalle dolomiti a venezia, pp. 73-126. autorità di bacino dei fiumi isonzo, tagliamento, livenza, piave e br e n t aba c c h i g l i o n e (1998) piano di bacino del fiume tagliamento: piano stralcio per la sicurezza idraulica del medio e basso corso venezia, 118 pp. br a v a r d j.p., ko n d o l f g.m. & pi e g a y h. (1999) environmental and societal effects of channel incision and remedial strategies in: da r b y s.e. & si m o n a. (eds.), incised river channels: processes, forms, engineering and management, wiley, pp. 303-341. ca s t i g l i o n i g.b. & pe l l e g r i n i g.b. (1981) g e o m o r f ologia dell'a lveo del brenta nella pianura tra bassano e padova in: zunica m. (a cura di), il territorio della brenta, amm. prov. di padova università di padova, pp. 12-32. da canal m., comiti f., surian n., mao l. & lenzi m.a. (2007) studio delle variazioni morfologiche del f. piave nel vallone bellunese durante gli ultimi duecento anni quaderni di idronomia montana, 27, pp. 259-271. do w n s p.w. & gr e g o r y k.j. (2004) river channel management. towards sustainable catchment hydrosystems arnold, london, 395 pp. gurnell a.m. (1997) channel change of the river dee meanders, 1946-1992, from the analysis of air p h o t o g r a p h s regulated rivers: research and management, 13, pp. 13-26. ha b e r s a c k h. & pi é g a y h. (2008) river restoration in the alps and their surroundings: past experience and future challenges in: ha b e r s a c k h., pi é g a y h. & rinaldi m. (eds), gravel-bed rivers vi from process understanding to river restoration, developments in earth surface processes, elsevier, pp. 703-738. hu g h e s m.l., mcdo w e l l p.f. & ma r c u s w.a. (2006) accuracy assessment of georectified aerial photographs: implications for measuring lateral channel movement in a gis geomorphology, 7 4, pp. 1-16. la m e d i c a s., da l l a va l l e e., pi l l i r. & an f o d i l l o t . (2007) variazioni di superficie e fissazione di carbonio in foresta nel territorio montano della regione veneto in riferimento all'applicazione del protocollo di kyoto forest@, 4(3), pp. 283-297. le o p o l d l.b. (1973) river channel change with time: an example geological society of america bulletin, 84, pp. 1845-1860. liebault f. & piegay h. (2001) assessment of channel changes due to long-term bedload supply decrease, roubion river, france geomorphology, 3 6, pp. 167-186. liebault f. & piegay h. (2002) causes of 20th century channel narrowing in mountain and piedmont r ivers of southeastern france earth surf. process. landforms, 27, pp. 425-444. mussio l. (2007) ricostruzione dell'evoluzione morfologica dell'alveo del torrente cellina negli ultimi 200 anni mediante tecniche gis tesi di laurea inedita, università di padova, 56 pp. petts g.e. (1979) complex response of river channel morphology subsequent to reservoir construction progress in physical geography, 3, pp. 329-362. rinaldi m. (2008) schede di rilevamento geomorfologico di alvei fluviali il quaternario, questo volume. ri n a l d i m., si m o n c i n i c. & sogni d. (2005) v a r i a z i o n i morfologiche recenti di due alvei ghiaiosi appenninici: il f.trebbia ed il f.vara. supplementi di geografia fisica e dinamica quaternaria, vii, pp. 313-319. ru m s b y b.t. & ma c k l i n m.g. (1994) channel and floodplain response to recent abrupt climate change, the tyne basin, northern england earth surface processes and landforms, 1 9, pp. 499-515. surian n. (1999) channel changes due to river regulation: the case of the piave river, italy earth surf. process. landforms, 24, pp. 1135-1151. su r i a n n. (2003) impatto antropico sulla dinamica recente del fiume piave (alpi orientali). in: bi a ncotti a. & motta m. (a cura di), risposta dei processi geomorfologici alle variazioni ambientali, m.i.u.r., glauco brigati, genova, pp. 425-440. surian n. (2006) effects of human impact on braided river morphology: examples from northern italy in: sambrook smith g. h., best j. l., bristow c. & pe t t s g. e. (eds.), braided rivers, ias special publication 36, blackwell science, pp. 327-338. su r i a n n. & ci s o t t o a. (2007) channel adjustments, bedload transport and sediment sources in a gravel-bed river, brenta river, italy earth surface processes and landforms, 32, pp. 1641-1656. surian n., pasqualini d. & tunis g. (2007) la dinamica dell'alveo del torrente torre (pianura friulana) nel corso degli ultimi due secoli quaderni dell'accademia delle scienze di torino (sottoposto). su r i a n n., pe l l e g r i n i g.b. & sc o m a z z o n e. (2005) variazioni morfologiche dell'alveo del fiume brenta indotte da interventi antropici suppl. geografia fisica e dinamica quaternaria, vii, pp. 339-345. surian n. & rinaldi m. (2003) morphological response to river engineering and management in alluvial channels in italy geomorphology, 5 0, pp. 307-326. surian n. & rinaldi m. (2004) channel adjustments in response to human alteration of sediment fluxes: examples from italian rivers in: go l o s o v v . , be l y a e v v. & wa l l i n g d.e. (eds.), sediment transfer through the fluvial system, iahs publ. 288, pp. 276-282. vo l l o l. (1942) le piene dei fiumi veneti e i provvedimenti di difesa. il piave le monnier, firenze, 336 pp. williams g.p. (1978) the case of the shrinking channels the north platte and platte rivers in nebraska u.s. geological survey circular, 781, 48 pp. wi l l i a m s g.p. & wo l m a n m.g. (1984) d o w n s t r e a m effects of dams on alluvial rivers u.s.geological survey professional paper, 1286, 83 pp. wi n t e r b o t t o m s.j. (2000) medium and short-term channel planform changes on the rivers tay and tummel, scotland geomorphology, 3 4, pp. 195-208. wyzga b. (1993) river response to channel regulation: case study of the raba river, carpathians, poland earth surface processes and landforms, 18, pp. 541-556. 290 ms. ricevuto il 2 gennaio 2008 testo definitivo ricevuto l’8 maggio 2008 ms. received: january 2, 2008 final text received: may 8, 2008 n. surian et al. sess 2_16022011_tpr3.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 preliminary contribution of the geomorphological analysis in the evaluation of recent tectonic control in the tammaro river catchment (campania – molise) elena cartojan, paolo magliulo & alessio valente università degli studi del sannio, benevento corresponding author: e. cartojan <elena.cartojan@unisannio.it> abstract: cartojan e., magliulo p. & valente a., preliminary contribution of the geomorphological analysis in the evaluation of recent tectonic control in the tammaro river catchment (campania – molise). (it issn 0394-3356, 2011) the aim of this study is to highlight the preliminary results derived to the integrated geomorphological analysis of the tammaro river catchment (campania – molise) in order to recognize the role played by the recent tectonic activity in development and the evolution of the hydrographic network. riassunto: cartojan e., magliulo p. & valente a., contributo preliminare dell’analisi geomorfologica nella valutazione dedel controllo della tettonica recente sul bacino del fiume tammaro (campania – molise). (it issn 0394-3356, 2011) l’obiettivo del presente lavoro è quello di illustrare i primi risultati ottenuti dall’analisi geomorfologica integrata del bacino del fiume tammaro (campania molise), finalizzata al riconoscimento di un eventuale influenza da parte della tettonica recente sullo sviluppo e sull’evoluzione del reticolo idrografico. key words: quantitative geomorphology, geographic information system, hypsographic integral, recent tectonic, campania – molise. parole chiave: geomorfologia quantitativa, sistema informativo geografico, integrale ipsografico, tettonica recente, campania – molise. 1. introduction the aim of this study is to highlight the role played by the recent tectonic activity in the tammaro river basin (campania molise) as revealed by the organization and the evolution of the hydrographic network. the geomorphic processes currently occurring in the basin, represented by landslides and linear erosion, have also been taken into account. different types of investigation, such as quantitative geomorphic analysis, hypsometric analysis and statistical azimuthal distribution of river courses, integrated into a gis environment, have been used. they have provided some preliminary results concerning the widest and hierarchically highest sub-basins of tammaro river catchment. study area. the tammaro river, ~78 km-long, starts from a series of relieves belonging to the matese massif, located in the molise region. it is a 7th order tributary of the calore river and receives 22 major tributaries. the basin is nw-se elongated and is ~ 670 km2-wide; it shows a slightly concave side towards sw. the morphology of the basin is markedly asymmetrical, as the southwestern side displays the highest slope angles. thus, both the altitude and the slope angle ranges are irregularly distributed on the two sides of the basin. as a consequence, also the evolution and the hierarchy of the hydrographic network are different (fig. 1). from a geological point of view, the outer units of the southern apennine chain are present in the studied basin. they are mostly made up by deposits accumulated in the basins deformed by tectonic phases occurred between tortonian and pliocene (casnedi et al. 1982). these deposits mainly consist of sandstone and/or clay alternated with marl and limestone, belonging to the sannio and fortore tectonic units (pescatore et al. 2008 cum bibl.). the quaternary deposits are represented by scree-talus and alluvial deposits: the oldest are fine-grained and of fluvio-lacustrine origin, while the most recent are mediumor coarsegrained (bergomi et al. 1975). the area is also affected by a complex pre-quaternary fault system, with a nw-se and ne-sw orientation, which strongly affects the physiography and hydrography (pescatore et al. 2008). some recent tectonic features, e to w and n to s elongated, also occurs (pescatore et al. 1996). these features are rarely evident in the field, because of the prevalence of poorly conservative lithotypes (apat, 2007), often involved into landslides. 2. tools and methods data were collected using a gis (geographical information system) software by digitizing the drainage network on the basis of geo-referenced maps. these maps belong to the topographic map of italy at 1:50,000-scale (nn. 405, 406, 418, 419, 432). in such way, it was possible to create a database containing all the information and the results concerning the selected sub-basins, which were 87 89 88 investigated using different methods. in particular, the morphometric features of the each sub-basin have been defined by means of geomorphic quantitative analysis (ciccacci et al. 1980; 1988; lupia palmieri et al. 2001). at first, the hydrographic network has been ordered according to the method of strahler (1954); then, the bifurcation ratio (rb), the direct bifurcation ratio (rbd) and the bifurcation index (horton, 1945; avena et al., 1967) were calculated. furthermore, in order to define more objectively the degree of hierarchy, the following parameters have been calculated: the hierarchical anomaly number (ga), the hierarchical anomaly density (ga) and hierarchical anomaly index (da) (avena et al., 1967). finally, using the percentage method of strahler (1952) the hypsographic curves of each basin were built and their relative hypsometric index values (hi hypsometric integral) were calculated by using the method of elevationrelief ratio relationship (keller & pinter., 2002). the hypsometric analysis provides useful information for the morphodynamic characterization of a given landscape (lupia palmieri et al., 2001), while the value of the hypsometric integral allows the parameterization of the basin in relation to the davis’ cycle of erosion. 3. data analysis figure 2 and figure 3 show high values of the bifurcation ratio for the streams of sanzano (rb = 5.43) and reinello (rb = 7,44). in general terms, values higher than 5 indicate that, almost certainly, basins are strongly controlled by tectonics (ciccacci et al., 1980). such a conclusion is also corroborated by the bifurcation index values (r), that are higher than 2 in both cases (2.55 and 2.10, respectively), indicating a low hierarchy in the geometry of the basins. for all the investigated sub -basins, low values of the hierarchical anomaly density (ga) and hierarchical anomaly index were generally found. they are usually typical of wellorganized catchments and this is in strong contrast to the r and rb values listed above. this discrepancy can be explained taking into account the lack of objectivity of the bifurcation ratios, which do not consider the influence of hierarchical anomalies. by combining this analysis with the study of hypsographic curves (fig. 4) and related indices, a predominance of convex curves, with hi> 0.55, was noted. such hi value is attributed by ciccacci et al. (1988) to basins in a “phase of disequilibrium” or in a "juvenile" stage (sensu strahler, 1952), and therefore it is associated with a prevailing vertical erosion by the watercourses. however, the presence of inflection within the hypsographic curves suggests that the morphogenetic processes are very complex, differing along the watercourse, fig. 1, dem (digital elevation model) of the tammaro river catchment. modello digitale di elevazione del bacino idrografico del f. tammaro. fig. 2, morphometric parameters: a) surface; p) perimeter; n) number of streams; rb) bifurcation ratio; rbd) direct bifurcation ratio; r) bifurcation index. parametri morfometrici: a) area; p) perimetro; n) numero di aste fluviali; rb) rapporto di biforcazione; rbd) rapporto di biforcazione diretto; r) indice di biforcazione fig. 3, morphometric parameters: ga) hierarchical anomaly number; ga) hierarchical anomaly density; ∆a) hierarchical anomaly index; d) drainage density; tu) suspended sediment yield (t/square km/year); hi) hypsometric integral parametri morfometrici: ga) numero di anomalia gerarchica; ga) densità di anomalia gerarchica; ∆a) indice di anomalia gerarchica; d) densità di drenaggio; tu) trasporto torbido unitario medio annuo; hi)integrale ipsometrico e. cartojan, p. magliulo & a. valente 89 ms. received: testo ricevuto il with a predominant areal erosion on slopes in the upper parts of the basins and an increase of linear erosion in the lower parts. in conclusion, the preliminary results obtained from the present analysis are in agreement with previous studies dealing with recent tectonics (nappi et al., 2007). such studies pointed out the presence of a nw-se trending active structural side, that is highlighted by the longitudinal profiles showed in fig. 4a, that display a clear knickpoint at the altitude of 600÷700 m. references apat (2007) – note illustrative della carta geologica d’italia alla scala 1:50.000, foglio 432 benevento, a cura di chiocchini u., se.l.ca, firenze avena g. c., giuliano g. & lupia palmieri e. (1967) – sulla valutazione quantitativa della gerarchizzazione ed evoluzione dei reticoli fluviali. boll. soc. geol. it., 86, 781-796 bergomi g., manfredini m. & martelli g. (1975) note illustrative della carta geologica d’italia. foglio 173. servizio geologico d’italia, 83 casnedi r., crescenti u. & tonna m. (1982) evoluzione dell’avanfossa adriatica meridionale nel pliopleistocene sulla base di dati nel sottosuolo. mem. soc. geol. it., 24, 243-260. ciccacci s., fredi p., lupia palmieri e. & pugliese f. (1980) – contributo dell’analisi geomorfica quantitativa alla valutazione dell’entità di erosione nei bacini fluviali. boll. soc. geol. it. 99, 455-516. ciccacci s., d’alessandro l., fredi p. & lupia palmieri e. (1988) contributo dell’analisi geomorfologica quantitativa allo studio dei processi di denudazione del bacino idrografico del torrente paglia (toscana meridionale – lazio settentrionale). suppl. geogr. fis. din. quat., i, 171-188. horton r. e. (1945) – erosional development of streams and their drainage basins: hydrophysical approach to quantitative morphology. geol. soc. amer. bull., 56, 275-370. keller e. a. & pinter n. (2002) – active tectonics: earthquakes, uplift and landscape (2nd. ed.). prentice hall, new jersey. lupia palmieri e., biasini a., caputo c., centamore e., ciccacci s., del monte m., fredi p. & pugliese f. (2001) – geomorfologia quantitativa e morfodinamica del territorio abruzzese: iii il bacino idrografico del fiume saline. geogr. fis. dinam. quat., 24, 157-176. nappi r., alessio g., bellucci sessa e. & vilardo g. (2009) – analisi morfometrica integrata in ambiente gis applicata ad aree tettonicamente attive. mem. soc. geogr. it., 97, 113-129. pescatore t., pinto f., renda p., senatore m.r., tramutoli m. & valente a. (1996) avanfosse mioceniche dell’appennino meridionale (italia). rend. acc. sc. fis. mat., 63, 85-121, napoli. pescatore t.s., di nocera s., matano f., pinto f., quarantiello r., amore o., boiano u., civile d. fiorillo l. & martino c. (2008) geologia del settore centrale dei monti del sannio: nuovi dati stratigrafici e strutturali. mem. descr. carta geol. d’it., 77-94. strahler a. n. (1952) – hypsometric (area-altitude) analysis of erosional topography. geol. soc. amer. bull., 63, 1117-1142. strahler a. n. (1954) – quantitative geomorphology of erosional landscapes. c.r. 19 th intern. geol. cong., algers, sect. 13, part. 3, 341-354. fig. 4, a) longitudinal profiles of the analysed sub-basin; b) normalized hypsografic curves. a) profili longitudinali dei sub-bacini analizzati; b) curve ipsometriche normalizzate. january 15, 2011 15 gennaio 2011 preliminary contribution of the geomorphological ... imp.dewaeleetalgasmi geomorphosites of tozeur region (south-west tunisia) jo de waele1, felice di gregorio1, nabil gasmi2, maria teresa melis1 & mohamed talbi3 1department of geology, via trentino 51, 09127 cagliari e-mail: geoam@unica.it 2faculté de sciences humaines et sociales, 94, bd. du 9 avril 1938, 1007 tunis e-mail: nabil.gasmi@fshst.rnu.tn 3institut des régions arides, medenine, route de djorf km 22.5, 4119 medenine e-mail: talbim@ati.tn abstract: j. de waele et al., geomorphosites of tozeur region (south-west tunisia). (it issn 0394-3356, 2005). tozeur is the most important tourist town of south-western tunisia, situated in between the two salt lakes chott el djerid to the south and chott el gharsa to the north. this area is known for its luxuriant oasis in the middle of the desert (tozeur, gafsa, nefta etc.), the mountain chains to the north close to the border with algeria with its villages and waterfalls (tameghza, chebìka, midès), the mountain chain east of tozeur (jbel morra etc.) with its arid canyons, and the wide salt plains (chotts). tourists usually visit the region rapidly without staying overnight, overlooking and ignoring the great geomorphologic and geological interesting places and landscapes. therefore, in the framework of a research project performed by the department of geology of the university of cagliari in collaboration with the institut des régions arides at medenine and with the "faculté de sciences humaines et sociales" of tunis and financed by the sardinian regional government (r.l. 11 aprile 1996, n° 19), our multidisciplinary research team has studied twenty-one geosites and geological landscapes in the region of tozeur, with the purpose of constituting a network of geosites in these arid and semiarid areas. field work combined with remote sensing techniques have enabled to start preparing thematic maps of these geosites which, together with their description (genesis, evolution, state of conservation, proposals of valorisation, etc.) will be useful for obtaining financial aid for their protection and valorisation. the definition of morphostructural units landform analysis at a large/medium scale was performed by telegis laboratory, involved in these studies on southern tunisia from 1997 in collaboration with the institute des régions arides, applying remote sensing techniques on multi-spectral satellite images. during this project the interpretation keys for the image classification were created in the different steps of field observations and digital image processing. the radiometric and geometric responses were used for the discrimination of spectral units (lithological sequences) and textural units defined by photointerpretation techniques (structural and landscape units like anticlines, fault-controlled valleys or forms like chevron, etc.). many of the studied geomorphosites are represented by canyons (gorges de ben nebhana, sidi bou helal, thelja, en negueb, chaabet es sfa, ben hamed, midès, etc.) and waterfalls (grande cascade and cascade de l'oasis at tameghza, cascade de chebìka and its geological-structural features). others are related to aeolian and meteoric processes (barchan dunes of el ghadayer, morpho-sculpture of ong el jmel, yardangs of el ghadayer, nebkha fields of chamsa). the remaining geosites are an ancient lacustrine coastline testified by a lumachelle with cardium in the jehim oasis near tozeur, the anticline of brikis close to tameghza, and an ancient phosphate mine at chouabin (jbel chouabin close to redeyef), a representative part of chott el djerid, the delta of oued mellah and the alluvial cone of oued foum el khanga and the ancient oasis (corbeille) of nefta. these sites and landscapes of geological and geomorphological interest represent the entire geological history of the tozeur and the chotts region fairly well. this history starts from early cretaceous, and the various sites narrate the sedimentary and tectonic events, the palaeo-environmental and palaeo-climate episodes, the birth, development and extinction of animal and plant species, the geomorphological processes and depositional events, explaining the present morphology, climate and landscape in a most interesting scientific and educational way. the linking of all these places of geological and geomorphologic interest in networks of geosites along a thematic issue (the "living desert" network with nebkha and barchan dunes, yardangs and aeolian sculptures, the "rocks and water" network with waterfalls, mountains and canyons, the "earth’s memory" network across the canyons of jbel morra-sidi bou helal passing through more than 100 million years of earth's geological history, the “phosphate route” network with active and abandoned phosphate mines and their environmental impact and the “changing environment and climate” network with salt pans, fossil shorelines and abandoned oasis) give an interesting opportunity of telling the history of the earth, promoting geology and geomorphology to the local people and to the visitors. in fact, geological heritage can and should become a cultural and economical resource for the local people, and therefore these inhabitants should be taught understanding their natural and cultural environment, enabling them to use these elements in the framework of a touristic and sustainable development of their region. riassunto: j. de waele et al., geomorfositi della regione di tozeur (tunisia sud-occidentale). (it issn 0394-3356, 2005). tozeur è il principale centro turistico della tunisia sud-occidentale, situato tra i due laghi salati dello chott el djerid a sud e lo chott el gharsa verso nord. quest’area è rinomata per le sue belle oasi in mezzo al deserto (tozeur, gafsa, nefta ecc.), le catene montuose con i villaggi, le oasi di montagna e le cascate a nord vicino al confine con l’algeria (tameghza, chebìka, midès), la catena di montagne con i numerosi canyon ad est di tozeur (jbel morra, ecc.) e le grandi pianure salate (chotts). in genere i turisti visitano la regione molto rapidamente senza poter conoscere ed apprezzare i caratteri essenziali dei paesaggi e dei numerosi siti d’interesse geologico e geomorfologici presenti. per questo motivo il gruppo di ricerca multidisciplinare, composto da ricercatori del dipartimento di scienze della terra dell’università di cagliari, dell’institut des régions arides di medenine e della faculté de sciences humaines et sociales dell’università di tunisi, ha predisposto un progetto finanziato dalla regione autonoma della sardegna (l.r. 11 aprile 1996, n° 19), che ha consentito di individuare e classificare 20 geomorfositi e paesaggi geomorfologici nella regione di tozeur con lo scopo di creare un network di geomorfositi capaci di mettere in luce il valore del patrimonio geologico di quest’area desertica. il lavoro di rilevamento in campagna è stato combinato allo studio d’immagini satellitari per elaborare delle carte tematiche dei geomorfositi che, insieme alla loro descrizione (genesi, distribuzione, evoluzione, stato di conservazione, proposte di valorizzazione, ecc.) costituiscono un riferimento essenziale per la loro conservazione e valorizzazione. la definizione morfostrutturale delle diverse unità di paesaggio ad una scala medio-grande, mediante tecniche di remote sensing su immagini satellitari multispettrali, è stata eseguita nel laboratorio telegis dell’università di cagliari coinvolto negli studi in tunisia meridionale dal 1997 in collaborazione con l’institut des régions arides. le chiavi d’interpretazione per la classificazione delle immagini sono state create durante le campagne di rilevamento in loco e l’elaborazione delle immagini digitali in sede. le risposte radiometriche e geometriche sono state utilizzate per la discriminazione delle unità spettrali (sequenze litologiche) e delle unità tessiturali definite attraverso tecniche di foto-interpretazione (unità strutturali quali anticlinali, valli controllate da faglie o forme come chevron ecc.). molti dei geomorfositi individuati e studiati sono dei canyon (gorges de ben nebhana, sidi bou helal, thelja, en negueb, chaabet es il quaternario italian journal of quaternary sciences 18(1), 2005 volume speciale, 223-232 224 j. de waele et al. 1. introduction the concepts “geosite” and “geological heritage” became widely used since the beginning of the 90’s and researchers from all over europe started discussing on the conservation of geological sites and landscapes. the first important european meeting on geo-conservation was organised at digne-les-bains (france) in 1991 and during this event the “international declaration of the rights of earth’s memory” was ratified and a first attempt of cataloguing geosites was presented in order to start building a versatile data base (barca & di gregorio, 1991a; 1991b). since then our multidisciplinary research team has started inventorying geosites in sardinia covering almost the whole regional territory (barca et al., 1992; panizza v. & cannillo, 1994; barca et al., 1995; 1996; de waele et al., 1998; 1999; ardau & de waele, 1999; arisci et al., 2001; 2002; de waele et al., 2002; 2003a; 2003b; 2003c) and giving rise to a detailed work on geological heritage of the province of cagliari (barca & di gregorio, 1999). all these researches have been carried out in the framework of international research programs such as “geosites” of the international union of geological sciences started in 1996 and “geomorphological sites”, a working group found in 2001 by the international association of geomorphologists. the national studies have had a further impulse thanks to the italian cofin 2001-2003 project “geosites in the italian landscape: research, evaluation and valorisation”, in which framework two workshops have already been organised during which italian and foreign researches have confronted and discussed their scientific results. geoconservation is not yet properly developed in the african continent, although the first attempts are starting to obtain some preliminary results especially in south africa (reimold, 1999). our decennial experience on geosites and geomorphosites and starting from the concepts of geomorphological asset evaluation as defined by panizza m. & piacente (1993) and poli (2003), has brought our research team to start working also in north-african countries and thanks to several research projects financed by the sardinian regional government we have commenced cataloguing sites of geological and geomorphological interest in the middle atlas of morocco (de waele et al., 2003d) and in the tozeur region in tunisia (di gregorio et al., 2002). this paper describes the results of the researches on geomorphosites and geological heritage performed in the region of tozeur (south-west tunisia). 2. geology of the region tozeur is located in south-western tunisia, between the two salt lakes chott el djerid to the south and chott el gharsa to the north (fig.1). sfa, ben hamed, midès, ecc.) e cascate (grande cascade e cascade de l'oasis a tameghza, cascade de chebìka e le sue eccezionali caratteristiche geologico-strutturali). altri sono legati a processi eolici e meteorici (barcane di el ghadayer, morfoscultura di ong el jmel, yardang di el ghadayer, campi di nebkha di chamsa). i restanti geomorfositi sono: un’antica linea di costa lacustre testimoniata dal livello sedimentario a lumachelle con cardium nell’oasi di jehim presso tozeur, l’anticlinale di brikis a tameghza, un’antica miniera di fosfati a chouabin (jbel chouabin nei pressi del villaggio di redeyef), il delta dell’oued mellah, il cono fluvio-sedimentario dell’oued foum el khanga, un settore paesaggisticamente rappresentativo dell’immenso chott el djerid e l’oasi antica di nefta (corbeille). questi siti e paesaggi d’interesse geologico e geomorfologico rappresentano abbastanza compiutamente l’intera storia geologica della regione di tozeur e degli chott. questa storia geologica inizia nel cretaceo inferiore, ed i numerosi siti raccontano eventi sedimentari e tettonici, episodi paleo-ambientali e paleo-climatici, la comparsa, l’evoluzione e l’estinzione di specie animali e vegetali, i processi d’erosione e deposizione di sedimenti, che forniscono un quadro esauriente e completo della morfologia, del clima e del paesaggio attuale di elevato interesse didattico-culturale. l’interconnessione di tutti questi siti di interesse geologico e geomorfologico in network tematici (il network “deserto vivente” con le nebkha, le barcane, gli yardangs e le sculture eolico-meteoriche, il network “rocce ed acqua” con montagne, cascate e gole, il network “la memoria della terra” con gli attraversamenti dei canyons del jbel morra-sidi bou helal che consentono di percorrere nelle sequenze stratigrafiche più di 100 milioni di anni di storia della terra, il network “il sentiero dei fosfati” con miniere di fosfati attive ed abbandonate e il loro impatto sull’ambiente e il network “il clima e l’ambiente che cambia” con le antiche rive degli chotts, le pianure salate attuali ed oasi abbandonate) consente di raccontare la storia della terra, promuovendo la conoscenza dei fenomeni geologici e geomorfologici nei confronti sia della popolazione locale sia dei visitatori, in un ambiente semiarido ed arido dove sono limitate le possibilità di sviluppo. in tal senso, il patrimonio geologico può diventare una risorsa culturale ed economica di non trascurabile interesse per la regione. per questo occorre rendere gli abitanti consapevoli della ricchezza del loro ambiente naturale e culturale, creando le opportunità per utilizzare queste risorse nel quadro di uno sviluppo turistico sostenibile della loro regione. keywords: desert, geomorphosite, desertification, remote sensing, geotourism, tozeur, tunisia. parole chiave: deserto, geomorfosito, desertificazione, remote sensing, geoturismo, tozeur, tunisia. fig. 1 general location of the study area. localizzazione dell’area di studio. the region of tozeur is part of the atlas fold and thrust belt that extends from morocco over algeria right up to west tunisia. to the east of the tunisian atlas lies a north-south trending mountain range corresponding to the major fault zone that divides the atlas from the eastern sahel block. the region of tozeur belongs to the southern tunisian atlas in which are distinguished the gafsa zone in the north, characterised by a series of anticlinal east-west trending mountain ranges mainly composed of late mesozoic carbonate sediments, and the southern chotts trough region composed of a since late carboniferous subsiding sedimentary basin. the gafsa zone can be subdivided in the metlaoui chain, composed of an east-west trending tight anticline with an overturned forelimb and gently dipping (30°) backlimb, separated from the structurally similar “chaine des chotts” (east of tozeur) by a large box syncline (outtani et al., 1995). according to ben ferjani (1990) the “chaine des chotts” is located on a jurassic graben and corresponds fundamentally to the inversion of this inherited structure. the tectonic events, probably 225geomorphosites of tozeur ... active at least since middle pleistocene (since lower quaternary sediments are involved in the fold-thrust structures along the mountain fronts), have involved only the upper part of the sedimentary cover (the basal décollement would be identified in the cretaceous stratigraphic levels) that has been folded as a sheet upon the rigid basement (outtani et al., 1995; fakhraoui, 1999). subsidence in the chotts area occurred mainly during middle triassic-jurassic as a consequence of the separation between europe and africa and has continued during miocene-early pleistocene related to the compression associated with the atlas orogeny (burrolet, 1956; 1991; zargouni, 1984; 1985; 1986; swezey, 1996; patriat et al., 2003). many of the east-west oriented anticlines and synclines in the gafsa zone are cut by northwest striking right-lateral strike slip faults among which the gafsa fault and the negrine-tozeur fault have to be mentioned. the first is the most important one, having direction n 120°-130° (boutib & zargouni, 1998) and table 1 table of the identified and studied geomorphosites in the region of tozeur, distinguished by their genetic process and degree of scientific and didactic-divulgation interest for geotourism and geoconservation purposes. tabella dei geomorfositi identificati e studiati nella regione di tozeur, distinti in base al processo genetico e al livello di interesse scientifico e didattico-divulgativo ai fini del geoturismo e della geoconservazione. n° géomorphosite name province commune genetic age of level of process rocks interest 1 midès canyon tozeur tameghza ft cm *** 2 brikis anticline tozeur tameghza t cm * 3 grande cascade waterfall tozeur tameghza ft eoc ** 4 cascade de l’oasis waterfall tozeur tameghza ft eoc *** 5 en negueb canyon tozeur tameghza ft cup-eoc *** 6 chebika canyon and waterfall tozeur tameghza ft cup-ol *** 7 ancient mine of chouabin gafsa redeyef a eoc ** 8 thelja canyon gafsa metlaoui ft cup-ol *** 9 oued foum el khanga alluvial fan tozeur tameghza f q ** 10 oued mellah delta tozeur hamma f q * 11 ong el jemal aeolian sculpture tozeur el hamma du jerid m plio-q ** 12 el ghadayer yardangs tozeur nefta w q * 13 el ghadayer barchan dunes tozeur nefta w q * 14 chamsa nebkha fields tozeur tozeur-nefta wb q * 15 cardium lumachelle of jehim tozeur tozeur s q * 16 chaabet es sfa canyon tozeur degueche ft cup *** 17 sidi bou helal canyon tozeur degueche ft cup *** 18 ben nebhana canyon tozeur degueche ft cup ** 19 ben hamed canyon tozeur degueche ft cup *** 20 chott el jerid salt pan tozeur degueche ts q *** 21 corbeille de nefta oasis tozeur nefta a mio-plio ** the main genetic processes that are responsible for the formation of the geomorphosites are: ft = fluvial-tectonic; t = tectonic; a = anthropic; f = fluvial; m = meteoric ; w = aeolian ; wb = aeolian-biological ; s = sedimentary ; ts = tectonic-sedimentary. the age of the rocks : cm = middle cretaceous ; cup = upper cretaceous ; eoc = eocene ; ol = oligocene ; mio = miocene; plio = pliocene ; q = quaternary. level of interest : * = moderate ; ** = high ; *** = very high. 226 showing a lateral offset of 1 km, and seismological and stratigraphical data (chihi, 1979) together with the presence of thermal hot springs along the fault (coque, 1962) indicate that it is still active today. the oldest outcropping rocks of the region are of upper cretaceous age. at j. bou helal the outcropping sequence starts with the evaporites of beida containing rare ostracods of middle turonian, followed by a sequence of marls, whitish dolostones and limestones with abundant fossils such as foraminifers, ostracods, echinoids and ammonites of lower-middle coniacian age. this sequence is characterised by the presence of a hardground encrusted by oysters at the foot of the upper limestone levels (abdallah, 1987; abdallah et al., 1995). santonian starts with 40 m of greyish clays and marls (with santonian ostracods, echinoids and foraminifers) followed by ammonite containing limestone beds. campanian is characterised by greenish marls and marly limestones (with abundant fossil oysters) followed by white ammonite and echinoid-bearing limestone beds with clear evidence of emersion episodes. maastrichtian is dominated by massif and locally fossiliferous limestone beds dated on the basis of foraminifers, nautiloids and ostracods. at the end of cretaceous a short continental period interrupts sedimentation, immediately followed by dark gypsum-rich clays with phosphate levels deposited in a lagoonal basin (bensalem, 2002). this sequence has been grouped in the about 70 meters thick thelja formation that surmounts a silicified horizon (burrolet, 1956; chaabani, 1978). the economic phosphate deposits have been discovered in 1885 by philippe thomas at thelja gorge and underground mining started at metlaoui in 1899. the phosphate levels, alternated with bioturbated clays, belong to the ypresian and contain shark teeth and tortoise carapaces (sassi, 1974). phosphate levels are followed by two limestone beds with silex nodules (ypresian-lutetian) and carbonate-rich clays with gypsum levels (priabonian). during oligocene sedimentation becomes continental characterised by conglomerates with carbonate and clayey cement (fakhraoui et al., 1995; regaya et al., 2001). neogene is mainly characterised by coarse and fine sandy continental deposits dated from middle miocene up to villafranchian, this last constituted of sediments with cardium. the actual morphology has been defined during quaternary with the emplacement of several mostly continental deposits. in particular at least three generations of terraces have been recognised, all characterised by silty yellowish and more or less reddish sediments with intercalations of conglomerates and gypsum crusts. these terraced sediments cover unconformably the slightly tilted miocene sequences and have been dated respectively middle pleistocene, upper pleistocene and holocene (ben ouezdou et al., 1996). during holocene sediments of aeolian origin have been deposited, mostly captured in nebkhas and sometimes forming barchan dunes. also the sebkha soils of the chotts cover wide extensions of territory in the region of tozeur, characterised by fine wet sediments and brines in winter and mud cracked surfaces with salt and gypsum crusts in summer. finally the recent alluvium has to be mentioned, with more or less fine sediments depending on the distance from the jebels. among these transported sediments also the phosphate silts deriving from the mine industry can be classified, such as the ones of the oued el mellah. 3. methodology the geomorphosites of tozeur region have been chosen on a preliminary basis using existing geographical and geological maps and scientific papers on geology and geomorphology, but also tourist maps and guide-books. several field campaigns have been organised to identify and classify interesting geosites and geomorphosites, to verify the collected bibliographical data and to make detailed observations and gather further documentation (e.g. geological sketches, geomorphological processes, photographs). according to panizza m. (2001) a geomorphosite is “a landform with attributes which qualify it as a component of the cultural heritage”. on the field a sheet file has been compiled in which, together with the data of identification of the site (e.g. commune, locality, co-ordinates, altitude, etc.) also data on accessibility, visibility, geology and geomorphology, use and state of conservation are reported. an example of such a sheet file, adopted by our research team also in other north-african countries, is reported in figure 2. the identification, classification and graphical representation of the geomorphosite networks have been completed using remote sensing techniques. the satellite image interpretation has been performed using a legend in which the lithological units and the main morphologies have been classified. the choice of the legend classes has been focussed in particular on the geomorphological systems in which the chosen geomorphosites are located. the analysis of medium-infrared band combinations has allowed to recognise in a preliminary phase the different lithological units, by means of the creation of interpretation keys based on field surveys. the following data have then been analysed to characterise the morphology of the study area: lithology, tectonics, drainage pattern, land cover and topography. the use of satellite images has proven to be an ideal instrument for the recognition of the main landforms, guiding the field campaigns in a remarkable way. the almost complete absence of vegetation enhances the recognition of the different lithologies that can easily be revealed by their spectral response, and the distinction of topography has been enhanced introducing shadow analysis. the general structure of the area and the most important faults and alignments have been put in evidence by image elaboration techniques using directional filters associated with spectral analysis. remote sensing analysis has also been a powerful tool to study vast depositional systems such as the delta of oued el khanga, an inactive river fan, relic of much wetter periods, that flows into the chott el gharsa crossing transversally the ridge of el manndra-bliji. this fan has also been cut by neotectonic faults, clearly evidenced also by recent fluvial deviations, and visible using satellite images. the result of the remote sensing analysis, combined with terrain work, has enabled to compile the “map of geosites and geomorphosites of the region of tozeur” in which structural, lithological and geoj. de waele et al. 227geomorphosites of tozeur ... fi g. 2 e xa m p le o f s he et fi le u se d fo r th e su rv ey , d es cr ip tio n an d c la ss ifi ca tio n of t he g eo m or p ho si te s. e se m p io d el la s ch ed a d i r ile va m en to , d es cr iz io ne e c la ss ifi ca zi on e d ei g eo m or fo si ti ut ili zz at a. 228 morphological data are resumed. the main purpose of these geomorphological training and research activities was to make the link between the single geomorphosites (intrinsic values) and the surrounding landscape (overall value) to form a complete perception of the importance of geological heritage in the region. in fact, only by means of a rigourous process of scientific awareness of this heritage it will become possible to create the basis for a conscient use in a context of sustainable development and valorisation through geotourism. this type of cultural tourism can be explicated very well in semi-arid and arid regions, because the landscape observation and analysis are favoured, and can become a good opportunity of economical growth. because of their easy perception (recognisability), their characteristic form (completeness), their state of conservation (exemplarity) and their effective possibility of visit (accessibility) geomorphosites can be defined ideal for valorisation and for geotourism (poli, 2003). a particularly significant and innovative aspect of this research is the proposal of networks, in which geomorphosites and geosites are linked by similar geomorphological processes, making their identification and recognition easier. this distinction in thematic networks of geosites and geomorphosites makes it also easier to define coherent actions of planning, valorisation and conservation. 4. geomorphosites for the moment a total of twenty-one geomorphosites have been chosen in the region of tozeur and are reported in table 1. these sites, in the prevision of their valorisation though geotourism, have been grouped in thematic circuits according to their geographical, geological, geomorphological and genetical characteristics. these circuits are: the "living desert", the "rocks and water", the "earth’s memory", the “phosphate route” and the “changing environment and climate” networks (fig.3). j. de waele et al. fig. 3 proposed network of geomorphosites organised in thematic itineraries related to prevalent genetic processes. rete di geomorfositi proposti organizzata per itinerari tematici legati ai processi genetici prevalenti. the "living desert" network is situated in the chott el gharsa region and can be reached departing from the ancient oasis of tozeur and following the road that leads to the famous ong el jmel natural sand sculpture. this network combines four geomorphosites: the nebkha fields of chamsa, the barchan dunes of el ghadayer, the yardangs of el ghadayer and the above mentioned ong el jmel geomorphosite. this network explains the products of aeolian processes in semiarid regions, the evolution of sand dunes, from young nebkha dunes over mature barchan dunes ending up with partially demolished dunes (yardangs). also the famous ong el jmel sand sculpture is inserted in this network, being an residual erosion form assuming the silhouette of a sitting dromedary, related to morphoselective meteoric processes. even though these single landforms are not easily readable on landsat images, because of their relatively small dimensions, on the most western side of the study area the greatest of the barchan dunes can be distinguished, reaching almost 150 meters of width. the "rocks and water" network, showing the landscape modelling and evolution through fluvial processes, is located in the chebika and tameghza mountains and combines seven geomorphosites: the canyons of midès and en negueb, the waterfalls of tameghza (“grande cascade” and “cascade de l’ oasis”), the anticline of brikis, the canyon, geological structures and waterfall of chebika (fig. 4) and the alluvial cone of oued foum el khanga (mamou, 1981). these seven sites represent the geomorphologic evolution of river profiles: water slowly erodes the outcropping rocks, accelerating the process during uplifting episodes (the tectonic evolution of the tameghza mountains can easily be explained showing the brikis anticline), and the alternation of hard and soft rocks causes differential erosion, formation of waterfalls and alternation of narrow canyon passages with larger riverbeds. at the end of the voyage the water flows out of the narrow gorges and enters the wide subsiding plains forming great alluvial fans. the satellite image, as said before, clearly puts in evidence the alluvial fan and the neotectonic movements, but also reveals wide and important structures such as chevrons, the smaller of which can also be easily distinguished on the field. close to tozeur, in the “chaine des chotts” mountains, the "earth’s memory" network is located comprising four canyons passing transversally through most of the cretaceous sedimentary sequence. in fact, the three canyons of sidi bou helal, ben nebhana and ben hamed cut the mountain range in its southern flank, while the chaabet es sfa canyon crosses the northern flank instead (ben ouezdou et al., 1996; gasmi, 1997). in these canyons the didascalic cretaceous sequence of this region can be observed in good exposure, showing many fossiliferous beds with ammonites, echinoids, oysters and gasteropods, allowing the visitors to go through 100 million years of earth’s history. also morphoselective meteoric processes have shaped interesting forms in the calcarenites, such as the mushroom-like rock sculptures in the ben hamed gorge (fig. 5). furthermore in some canyons of the southern flank ancient human settlements (roman dams and quarries, abandoned oasis, etc.) enrich these geomorphosites and the network in a whole. the “phosphate route” is of a more “human dimension” showing an abandoned underground phosphate mine near chouabin, the immense active phosphate mines (underground and open pit cultivation) and their environmental impact (tailings, sterile heaps, excavations, phosphate mud in the draining rivers, etc.) on the immediate environs but also at greater distance such as at the thelja gorge or at the oued el mellah delta. the analysis of satellite images clearly puts in evidence the dispersion of dust and phosphate muds, with a unique spectral response. finally the “changing environment and climate” network comprises three geomorphosites close to 229geomorphosites of tozeur ... fig. 4 eocene sedimentary sequence in almost vertical attitude in which the softer clay beds are in negative relief respect to the silicificated limestone beds. sequenza eocenica in giacitura subverticale nella quale gli strati argillosi teneri risultano più intaccate rispetto ai banchi silicizzati. tozeur: a small outcrop of quaternary littoral sediment very rich in cardium in the oasis of jehim testifying an ancient shoreline of the chott el djerid, the actual salt plain itself (ben ouezdou, 1999) and the corbeille of nefta with the ancient spring sites that are dried up due to overexploitation of the aquifer. 5. conclusions geoconservation and geotourism are widely used and accepted terms in europe and north-america, but are new concepts for tunisia. although geological heritage in tunisia is well known and many areas have been thoroughly studied by geologists, this geological and geomorphological knowledge is still restricted to few people, and should be diffused to a wider public. the author’s attempt is to explain the geological and geomorphological characteristics of the region of tozeur to the local people and to the visitors, enriching the already existing tourist offer with new themes of interest that are based on the geological and geomorphological resources that are particularly well represented in the region. in fact, many of the geomorphosites included in this paper are well-known tourist attractions, but the geological and geomorphological significance of these sites is never explained. the connection of several of these geomorphosites in circuits (or networks) has the purpose of explaining the geological and geomorphological evolution of these sites, giving a more educational explanation of sometimes complex and slowly developing phenomena. in the framework of the valorisation of the territory it is also important to make a link between natural processes and human activities: in many geomorphosites presented here also the human presence is clearly visible with archaeological remains (prehistoric graffiti, roman dams, abandoned oasis and settlements, etc.) or historical-technological curiosities (the “lezard rouge”, a tourist train along the suggestive ancient phosphate mine railtracks, abandoned and still operating phosphate mines, etc.). aside all these sites of geological or geomorphological interest many other important localities exist (e.g. the restored oasis or “corbeille” of nefta dried up due to human intervention and global change, museums, experimental date palm tree plantations etc.) and the integrated tourist development of all these natural and cultural resources can give new economic opportunities to this arid and semiarid region. acknowledgements this study has been carried out with the financial aid of the sardinian regional government in the framework of the project "identification, classification and valorisation of important landscapes and geosites in south tunisia” (responsible prof. felice di gregorio) (regional law n°19/1996). for the conceptual part of this work reference has been made to the national project cofin 2001-2003 “geomorhosites in the italian landscape”, national coordinator prof. sandra piacente, responsible of the local research unit prof. antonio ulzega and prof. felice di gregorio. the authors would like to thank mario panizza and sergio ginesu for their critical advice. references abdallah h. (1987) le crétacé supérieur de la chaîne nord des chotts (sud tunisien): biostratigraphiesédimentation-diagenèse phd thesis, université de bourgogne, dijon, 255 pp. abdallah h., memmi l., damotte r., rat p. & magniezjannin f. (1995) le crétacé de la chaîne nord des chotts (tunisie du centre-sud): biostratigraphie et comparaison avec les régions voisines cretaceous research, 16, pp. 487-538. ardau f., de waele j. (1999) geosites of the tacchi area (central-east sardinia, italy) in: d. barettino, m. vallejo & e. gallego (eds.), towards the balanced management and conservation of the geological heritage in the new millenium, pp. 8793. arisci a., de waele j., di gregorio f., ferrucci i. & follesa r. (2001) geosites and touristic development of the karstic coastline of southwest sardinia in: e. ozhan (ed.), medcoast 01: proceedings of the fifth international conference on the mediterranean coastal environment, 23-27 october 2001, hammamet, tunisia, middle east technical university, ankara, turkey, vol. 1, pp. 302-314. arisci a., de waele j., di gregorio f., ferrucci i., follesa r. & piras g. (2002) the human factor in natural and cultural landscapes: the geomining park of sardinia proceedings of the international conference on "natural and cultural landscapes 230 j. de waele et al. fig. 5beautiful example of mushroom-like meteoric selective erosion rock sculpture in the ben hamed gorge. bell’esempio di roccia a fungo d’erosione meteorico-selettiva nella gorge di ben hamed. the geological foundation", dublin, 9-11 september 2002 (in print). barca s. & di gregorio f. (1991a) conservation et valorisation du patrimoine géologique de la sardaigne: une proposition methodologique 1er symposium international sur la protection du patrimoine geologique, digne-les-bains, france 10-16 giugno 1991, pp. 84-92 . barca s. & di gregorio f. (1991b) proposta metodologica per il rilevamento dei monumenti geologici e geomorfologici bollettino dell'a.i.c., 83, pp. 25-31. barca s. & di gregorio (1999) paesaggi e monumenti geologici della provincia di cagliari saredit cagliari, 421 pp. barca s., di gregorio f. & mulas g. (1995) natural rock arches of the orosei gulf, sardinia, italy – in: e. ozhan (ed.), medcoast 95: proceedings of the second international conference on the mediterranean coastal environment, 24-27 october 1995, tarragona, spain, middle east technical university, ankara, turkey, vol. 1, pp. 217-229. barca s., di gregorio f. & cannillo c. (1992) rilevamento e valutazione dei monumenti geologici e geomorfologici del meilogulogudoro (sardinia n-w) bollettino dell’a.i.c., 86, pp. 7184. barca s., di gregorio f., floris c. & montis m. (1996) rilevamento e valutazione dei monumenti e delle aree di rilevante interesse geologico e geomorfologico nei monti del sulcis (sardegna s.o.) in: l. d’arienzo (ed.), studi di geografia e storia in onore di angela terrosu asole, pp. 189-335. ben ferjani a., burollet p. & mejri f. (1990) petroleum geology of tunisia etap, tunis, 194 pp. bensalem h. (2002) the cretaceous-paleogene transition in tunisia: general overview paleogeography, paleoclimatology, palaeoecology, 178, pp. 139-143. ben ouezdou h. (1999) chott el jerid et les oasis editions tozeur, 47 pp. ben ouezdou h., gasmi n. & bouassida l. (1996) contribution à l'étude géomorphologiqe du jebel sidi bouhlel et ses environs (sud-ouest de la tunisie) revue tunisienne de géographie, 30, pp. 53-80. boutib l. & zargouni f. (1998) disposition et géométrie des plis de l’atlas centro-méridional de tunisie : découpage et cisaillement en lanières tectoniques c. r. acad. sciences paris, sciences de la terre et des planètes, 326, pp. 261-265. burrolet p.f. (1956) contribution à l’étude stratigraphique de la tunisie centrale ann. min. géol. tunisie, 18, pp. 1-240. burrolet p.f. (1991) structures and tectonics of tunisia tectonophysics, 195, pp. 359-369. chaabani f. (1978) les phosphorites de la coupe de foum thelja. une série sédimentaire séquentielle à évaporites du paléocène phd thesis, université louis pasteur, strasbourg, 151 pp. chihi l. (1992) seismotectonic study in central and southern tunisia tectonophysics, 209, pp. 175178. coque r. (1962) la tunisie présaharienne : étude géomorphologique ed a. colin paris. 476 pp. de waele j., di gregorio f., follesa r. & piras g. (2002) i geositi dell'uomo nel parco geominerario storico ambientale della sardegna: alcuni esempi del sulcis-iglesiente (sardegna sud-occidentale) proceedings of the national conference "la geologia ambientale: strategie per il nuovo millennio", genova 27-29 giugno 2002 geologia dell'ambiente 11(1), pp. 192-197. de waele j., di gregorio f., el wartiti m., fadli d., malaki a. & melis m.t. (2003d) geomorphosites and geodiversity of the ifrane region (middle atlas, morocco) proceedings of the workshop "geomorphological sites assessment and mapping", cagliari 1-5 ottobre 2003, abstract volume. de waele j., di gregorio f., follesa r. & piras g. (2003a) geosites and landscape evolution of the "tacchi": an example from central-east sardinia proceedings of the workshop "geomorphological sites research, assessment and improvement", modena 19-22 giugno 2002 il quaternario (this volume) (in print). de waele j., di gregorio f. & pala a. (2003b) karstic geomorphosites of monte albo (north-east sardinia) proceedings of the workshop "geomorphological sites assessment and mapping", cagliari 1-5 ottobre 2003 il quaternario (this volume) (in print). de waele j., di gregorio f. & panizza v. (2003c) geomorphosites at risk: some examples from sardinia (italy) proceedings of the regional geomorphology conference mexico 2003, mexico city, 27 october 2 november 2003 (in print) de waele j., di gregorio f. & piras g. (1998) geosites inventory in the paleozoic karst region of sulcisiglesiente (south-west sardinia, italy) international congress progeo ‘98, 7-13 june 1998, belogradchik, bulgaria geologica balcanica 28(3-4), pp. 173-179. de waele j., di gregorio f. & piras g. (1999) the twenty most important karstic geosites of sardinia in: d. barettino, m. vallejo & e. gallego (eds.), towards the balanced management and conservation of the geological heritage in the new millenium, pp. 155-161. di gregorio f., talbi m., melis m.t., piras g., gasmi n., marini a., de waele j. & follesa r. (2002) progetto di ricerca per l'inventario, la tutela e la valorizzazione dei geositi in ambiente arido e semiarido nella regione di tozeur e di gafsa (tunisia) proceedings of the national conference "la geologia ambientale: strategie per il nuovo millennio", genova 27-29 june 2002 geologia dell'ambiente, 11(1), pp. 198-203. fakhraoui m. (1999) etude stratigraphique et structural des chaînes des chott : evolution géométrique et cinématique liée à l’accident sud atlasique thèse de doctorat de 3e cycle, univ.tunis ii, 243 pp. fakhraoui m., mahjoub k. & charni t. (1995) notice explicative de la carte géologique de hamma el jerid office nationale des mines, tunis, 25 pp. gasmi n. (1997) le jebal sidi bouhelal et ses environs: levés et commentaire de la carte géomorphologi231geomorphosites of tozeur ... que au 1/50.000 bsc. thesis in physical geography. université de tunis,122 pp., map 1/50.000. mamou ah. (1981) etude géologique et hydrogéologique de la région de tamerhza. possibilités de création de retenues souterraines au nord de jebal el ardhia phd thesis, institut de recherche de géologie et de mécanique, u.s.m. grenoble, 185 pp. outtani f., addoum b., mercier e., frizon de lamotte d. & andrieux j. (1995) geometry and kinematics of the south atlas front, algeria and tunisia tectonophysics, 249, pp. 233-248. panizza m. (2001) geomorphosites: concepts, methods and examples of geomorphological survey chinese sci. bull., 46, pp. 4-6. panizza m. & piacente s. (1993) geomorphological asset evaluation zeitschrift fur geomorphologie n.f., 87, pp. 85-117. panizza v. & cannillo c. (1994) rilevamento e valutazione di beni geografico-fisici di tipo geologico e geomorfologico in un’area della sardegna nordoccidentale riv. geogr. ital., 101, pp. 545576. patriat m., ellouz n., dey z., gaulier j. m. & ben kilani h. (2003) the hammamet, gabès and chotts basins (tunisia): a review of the subsidence history sedimentary geology, 156, pp. 241-262. poli g. (2003) dalla stanza delle meraviglie alle meraviglie della terra in: s. piacente & g. poli (eds), la memoria della terra. la terra della memoria, l’inchiostro blu ed., bologna, pp. 28-40. regaya k., ben mamou a., ben youssef m. & ghanmi m. (2001) notice explicative de la carte géologique de metlaoui office nationale des mines, tunis, 31 pp. reimold w. u. (1999) geoconservation a southern african and african perspective journal of african earth sciences, 29(3), pp. 469-483. sassi s. (1974) la sédimentation phosphatée du paléocène dans le sud et le centre ouest de la tunisie thèse des sciences, univ. paris sudorsay, 304 pp. swezey c.s. (1996) structural controls on quaternary depocentres within the chotts trough region of southern tunisia journal african earth sciences, 22(3), pp. 335-347. zargouni f. (1984) style et chronologie des déformations des structures de l’atlas tunisien méridional. evolution récente de l’accident sud-atlasique comptes rendus académie sciences, 299, pp. 71-76. zargouni f. (1985) tectonique de l’atlas méridional de tunisie. evolution géométrique et cinématique des structures en zone de cisaillement thèse des sciences, strasbourg, 292 pp. zargouni f. (1986) tectonique de l’atlas méridionale de tunisie. evolution géométrique et cinématique des structures en zone de cisaillement revue des sciences de la terra, mémoire iii, tunis, 304 pp. 232 j. de waele et al. impaginatosanto ecc... ppeerriiccoolloossiittàà ccoonnnneessssaa aa pprroocceessssii aalllluuvviioonnaallii iinn aarreeee ppeeddeemmoonnttaannee:: iill ccaassoo ddii ccaasstteellllaammaarree ddii ssttaabbiiaa iinn ppeenniissoollaa ssoorrrreennttiinnaa aa.. ssaannttoo11,, nn.. ssaannttaannggeelloo22,, aa.. bbeenneedduuccee33 && ff.. iioovvaannee33 1sezione di geologia applicata del dipartimento di ingegneria geotecnica dell’università di napoli federico ii 2dipartimento di scienze della terra dell’università di napoli federico ii 3geologo collaboratore esterno riassunto e’ stato effettuato uno studio sulla pericolosità connessa a processi alluvionali di un’area campione della penisola sorrentina dove esistono importanti centri urbani in parte sviluppati su conoidi attive. il settore in oggetto (castellammare di stabia) presenta condizioni geologico-geomorfologiche simili a quelle di molti altri territori comunali della penisola sorrentina – monti lattari e di altri settori pedemontani campani, prestandosi così come area “campione” per lo studio delle condizioni di pericolosità legata a processi alluvionali in bacini torrentizi. l’analisi stratigrafica, geomorfologica e storica, ha consentito l’individuazione di numerosi eventi alluvionali recenti, che hanno interessato questo settore della penisola sorrentina dalla fine del settecento ad oggi. lo studio della documentazione recuperata ha permesso di localizzare e distinguere i danni relativi ai singoli eventi, e talvolta di riconoscere le varie tipologie dei dissesti; è stata così redatta una carta dei danni in cui sono evidenziate le aree colpite da uno o più eventi alluvionali, nel periodo che va dal 1764 al 1987, valutando anche l’evoluzione urbanistica dell’area , tramite l’utilizzo di cartografie coeve degli eventi alluvionali studiati. in termini di precipitazioni giornaliere questi eventi non hanno avuto carattere di eccezionalità in quanto episodi temporaleschi della stessa intensità si sono ripetuti più volte sul territorio, senza effetti degni di rilievo. la particolarità di queste precipitazioni va ricercata nella loro concentrazione oraria, che purtroppo non può essere quantizzata a causa della mancanza di dati pluviometrici, ma comunque confermata dalle precise descrizioni citate nella ricerca storica. in generale, i dati raccolti hanno evidenziato le condizioni di alta pericolosità geomorfologica per processi alluvionali; in questi contesti l’individuazione e lo studio delle conoidi attive, accompagnati da una accurata ricerca storica, possono contribuire, in modo significativo, alla definizione delle situazioni di maggiore pericolosità e rischio. abstract a study of the geomorphological hazard due to alluvial processes in a sample area of surrentine peninsula was carried out. this was done by the reconstruction of the short term geomorphological evolution analysis, by collection of historical data and by reconstruction of urban development. although the selected area is quite small, its geomorhological, topographical and urban features are very similar to those of other zones of campania region; in fact some portions of the urban area are built on holocenic alluvial fans systems. for these reasons, it can be considered a representative ”sample area” in which the geomorphological hazard conditions due to alluvial processes in piedmont areas can be outlined. the studied area is located in the piedmont area of lattari mounts which is characterized by the presence of coalescent and entrenched alluvial fans systems. the oldest fans system are middle pleistocene in age while the youngest are holocene and have been active till historical times. this paper focuses its attention to the definition of hazard conditions of the youngest generation of fans. the collection of historical data evidenced that several alluvial events have taken place in this sector of surrentine peninsula since the end of 18th century. the reports are so detailed that it was possible to locate the damage for each event and in some cases to recognise the kind of damage; a “damage map” showing the zones affected by one or more alluvial events from 1764 to 1987 was thus produced. as the location of the damage of each alluvial event was based on historical topographic maps (1812, 1875, 1909, 1954 and 1990), the damage map also takes in account the urban development. a morphometrical analysis of the hydrographic basins feeding the fans has been also carried out in order to define their concentration time; basin area and media gradient, river length and media gradient, basin maximum , minor and media altitude have thus been calculated on a topographic map (1: 5.000 scale). although we do not have data on hourly precipitation, the minute description of historical reports allowed us to hypothesize that the studied alluvial events occurred in coincidence with isolated precipitation peaks concentrated in few hours. the study thus evidences the high geomorhological hazard and risk conditions due to alluvial processes of the castellammare urban area. unfortunately, the results obtained may concern many other urban areas of surrentine peninsula with similar geomorhological, topographical and urban conditions. in these contexts the individuation of active fans together with a detailed historical research can strongly contribute to a better definition of the areas of highest hazard and risk. parole chiave: pericolosità geomorfologica; ricerca storica, conoidi alluvionali attive; olocene; appennino meridionale key-words: geomorphologic hazard; historical research; active alluvial fans; holocene; southern apennines il quaternario italian journal of quaternary sciences 1155(1), 2002, 23-37 11.. pprreemmeessssaa la pericolosità geomorfologica viene definita come la probabilità che un evento alluvionale o franoso di determinato tipo o magnitudo, si verifichi in un determinato intervallo di tempo e in una certa area; essa, a differenza di altre pericolosità geologiche come quella vulcanica e sismica che risultano ineluttabili, è talvolta dovuta ad errati interventi dell’uomo sul territorio. in penisola sorrentina gli eventi che possono determinare situazioni di pericolosità geomorfologica sono riconducibili alle seguenti tipologie: 1) ffrraannee nneellllee ccoollttrrii ppiirrooccllaassttiicchhee (montella, 1841; ranieri 1841; lazzari, 1954; penta et al., 1954; civita & lucini, 1968; de riso & nota d’elogio, 1973; guida et al., 1974; 1986; civita et al., 1975; celico et al., 1986; guadagno, 1991; vallario, 1992; giasi et al., 1996; calcaterra et al, 1997; celico & guadagno, 1998; del prete & mele, 1999; guadagno et al., 1998; di crescenzo & santo, 1999; de riso et al., 1999; 2) ffrraannee iinn rroocccciiaa (civita et al., 1975; guida et al., 1986; de riso, 1992; budetta et al., 1991; 1994; budetta & santo 1993; santo & tuccimei, 1997; 3) ffrraannee iinn tteerrrreennii ffllyysscciiooiiddii (cotecchia & melidoro, 1966; civita et al., 1975; travaglini & valdinucci, 1964), 4) aalllluuvviioonnii: lazzari 1954; penta et al., 1954; vallario, 2001). mentre nei primi tre casi la letteratura fornisce una ricca casistica, nel quarto caso (alluvioni) emerge una lacuna soprattutto per quanto riguarda la segnalazione di danni legati a fenomeni di trasporto solido per alluvionamento. se escludiamo gli eventi di particolare intensità come quelli che hanno interessato il salernitano nel 1924 e nel 1954 (lazzari, 1954), i vari lavori non si soffermano su queste fenomenologie. la ricerca storica dimostra invece che l’area della penisola sorrentinamonti lattari è stata più volte interessata da fenomeni di trasporto-accumulo di natura detritico-fangosa verificatisi in occasione di eventi piovosi particolarmente intensi che, come approfondiremo in seguito, hanno provocato ingenti danni e, in alcuni casi, la perdita di vite umane. questa nota si propone di evidenziare la pericolosità geomorfologica connessa a processi alluvionali in aree pedemontane, attraverso la ricostruzione dell’evoluzione morfologica di breve termine, la ricostruzione storica degli eventi e l’analisi delle modificazioni antropiche subite dal territorio. l’area di studio (castellammare di stabia) presenta condizioni geologico-geomorfologiche simili a quelle di molti altri centri urbani della campania (penisola sorrentina-monti lattari, costiera amalfitana, monti di nocera e cava dei tirreni, monti di avella, monti picentini) ubicati in settori pedemontani, alimentati da bacini idrografici con elevata energia di rilievo ed impostati su rilievi calcarei ricoperti da una coltre di piroclastiti sciolte. per tale motivo essa si presta come area “campione” relativamente alla definizione delle condizioni di pericolosità legate a processi alluvionali in questi contesti ambientali. 22.. iinnqquuaaddrraammeennttoo ggeeoollooggiiccoo ee ggeeoommoorrffoollooggiiccoo ddeellllaa ppeenniissoollaa ssoorrrreennttiinnaa la dorsale della penisola sorrentina è costituita da rocce carbonatiche (calcareo-dolomitiche) d’età compresa tra il trias superiore ed il miocene, cui segue verso l’alto un complesso arenaceo-argilloso; nel suo insieme questa successione è ascritta all’unità stratigrafico strutturale monti picentinimonti lattari (bonardi et al., 1988). su tutti questi termini si rinvengono terreni quaternari d’origine ed età diversa: brecce calcaree antiche, depositi alluvionali, materiali piroclastici, detriti di falda, alluvioni recenti, depositi di spiaggia, detriti di frana. l’area oggetto di studio è situata nel settore settentrionale della penisola sorrentina (fig.1) e rientra prevalentemente nei territori comunali di gragnano e di castellammare di stabia estendendosi tra il torrente gragnano (a nord) ed il torrente dello scurolillo (a sud). 24 a. santo et al. fig. 1 carta delle coperture piroclastiche dell'area di studio con indicazione dei bacini idrografici pyroclastic covers map with location of main drainage basins. la città di castellammare di stabia si sviluppa su un territorio pedemontano caratterizzato da una serie di conoidi incastrate che si estendono dalla base dei monti lattari fino al mare, testimoniando un’intensa attività alluvionale succedutasi nel tempo. in quest’area (fig.2) sono presenti almeno tre generazioni di conoidi alluvionali (cinque et al., 1987; cinque, 1991; aucelli et al, 1996), la più antica delle quali r isale al pleistocene medio. essa è caratterizzata dall’assenza di materiali piroclastici e risulta costituita da ciottoli calcarei leggermente arrotondati ed eterometrici, con cemento calcitico che talvolta non riempie completamente i vuoti, conferendo alla roccia un aspetto vacuolare. le conoidi appena citate si conservano in alcuni lembi isolati e terrazzati (vallone del rivo san marco, sella di pimonte e foce del rivo scurolillo a pozzano) . le conoidi di seconda generazione sono incastrate nelle valli che dissecano le conoidi del pleistocene medio e sono caratterizzate dalla diffusa presenza di intercalazioni di materiale vulcanico, sia in posto sia rimaneggiato (fig.3). nella serie è intercalata, in giacitura primaria, l’ignimbrite campana (cinque et al., 1987) che, in altre località, è stata datata radiometricamente a 37.000 25pericolosità connessa a processi alluvionali ... fig. 2 schema geologico-geomorfologico dell’area studiata. da cinque (1991), ridisegnato. 1) calcari; 2) conoidi alluvionali di i generazione (pleist. medio); 3) conoidi alluvionali di ii generazione (pleistocene sup.); 4) conoidi alluvionali di iii generazione (olocene); 5) cordone dunare di bottaro-pioppaino (3600-2500 anni bp); 6) cordoni dunari di età storica; 7) paleofalesia versiliana; 8) piana alluvionale del f. sarno; 9) sondaggio; 10) traccia di sezione. geological and geomorphological sketch of the studied area. from cinque (1991), modified. 1) limestones; 2) alluvial fan deposits (middle pleistocene); 3) alluvial fan deposits (upper pleistocene ne); 4) alluvial fan deposits (holocene); 5) dune ridge of bottaropioppaino (3600-2500 yr bp); 6) dune ridges of historical age ; 7) paleo-seacliff (versilian); 8) sarno river alluvial plain; 9) borehole; 10) geological cross section fig. 3 stratigrafia della conoide di ii generazione (rivo foiano): 1) suolo; 2) ghiaie calcaree in matrice sabbiosa piroclastica; 3) livello di pomici bianche (diam. fino a 5 cm); 4) sabbia vulcanica grigia con pomici e scorie; 5) livello di pomici grigie (diam. fino a 5 cm; 6) ghiaie calcaree in matrice sabbiosa piroclastica.; 7) livello di pomici bianche (diam. pochi mm), gradate passanti ad una cenere compatta di colore grigio scuro; 8) deposito massivo costituito da una sabbia vulcanica inglobante clasti calcarei; 9) sabbie vulcaniche fini di colore grigio chiaro. stratigraphy of the middle pleistocene alluvial fan deposits: 1) soil; 2) calcareous gravels with sandy pyroclastic matrix; 3) white pumiceous level (diam. max. 5cm.); 4) grey volcanic sand with pumices and scories; 5) grey pumiceous level (diam. max. 5cm.); 6) ) calcareous gravels with sandy pyroclastic matrix;7) white pumiceous level (diam. max. 2mm.) evolving to a grey ash level; 8) massive volcanic sand with calcareous pebbles; 9) light grey, fine-grained volcanic sands. anni bp (deino et al., 1994); ciò consente l’attribuzione di questa fase alluvionale al pleistocene superiore. tra la fine del pleistocene superiore e l’olocene, le conoidi appena descritte subiscono un’intensa fase d’erosione lineare, cui fa seguito l'innalzamento del livello del mare riconducibile alla trasgressione versiliana, testimoniata da una paleofalesia che tronca le conoidi della seconda generazione, raggiungendo in alcuni punti l’altezza di circa 40 metri (cinque, 1991). la terza generazione di conoidi (conoidi di muscariello, sommuzzariello e quisisana; cinque, 1991) si presenta incastrata in quella del pleistocene superiore, è costituita prevalentemente da piroclastiti rimaneggiate e si sviluppa arealmente dalla falesia versiliana fino all’attuale linea di riva. i suoi prodotti, con particolare riferimento alla conoide del rivo san marco, ricoprono l’antico cordone dunare di bottaro-pioppaino, costituito da sabbie eoliche sovrapposte a depositi di spiaggia, che datazioni assolute e dati di sondaggio hanno fatto risalire a 3600 bp (barra et al., 1989). tali elementi hanno dunque permesso di datare indirettamente quest’ultima generazione di conoidi, attribuendole un’età storica e protostorica (cinque, 1991). per quanto riguarda la linea di riva, dopo la trasgressione versiliana, questa ha subito un graduale avanzamento, di circa tre chilometri, fino ad arrivare alla posizione attuale (cinque 1991); gran parte di questa progradazione è riconducibile, all'attività deposizionale che ha generato le conoidi di iii generazione e successivamente agli apporti piroclastici dell’eruzione vesuviana del 79 d.c. (sigurdsson et al., 1982). in particolare, quest’eruzione ha portato profonde modificazioni su tutto il territorio; infatti, oltre a causare la distruzione delle città di stabia, ercolano e pompei, ha ricoperto vaste porzioni dei versanti calcarei con più di un metro di pomici e lapilli, condizionando l’evoluzione geomorfologica di tutta l’area. 33.. ii ddeeppoossiittii rreecceennttii ccoorrrreellaabbiillii aa pprroocceessssii aalllluuvviioonnaallii eedd ii ddeeppoossiittii ppiirrooccllaassttiiccii oolloocceenniiccii il rilevamento geologico dell’area di studio è stato mirato prevalentemente ai depositi quaternari recenti delle conoidi di terza generazione e ai depositi piroclastici di età olocenica. depositi delle conoidi di terza generazione i depositi in oggetto sono quasi completamente ricoperti dall’abitato di castellammare di stabia e risultano affioranti solo nella parte apicale delle conoidi, in corrispondenza di alcuni terrazzi localizzati all'interno dei valloni che dissecano la generazione più antica. in particolare, all'interno dei rivi cannitello, san pietro e scurolillo sono state rilevate superfici terrazzate con estensione di alcune migliaia di m2 e con altezze fino a 10 m rispetto al fondo dell'incisione torrentizia. dall’osservazione diretta dei depositi è emerso che questi sono costituiti da ghiaie calcaree fortemente eterometriche, in abbondante matrice sabbioso-limosa di colore marrone e di natura vulcanica, ma soprattutto sono stati rinvenuti più volte, immersi nella matrice piroclastica, cocci di terracotta che sono una ulteriore prova dell’età storica delle conoidi di terza generazione. nella zona urbana, dove non sono osservabili tagli significativi, sono stati raccolti i dati di sondaggi che hanno evidenziato ripetute fasi di alluvionamento, testimoniate dalla presenza da ghiaie calcaree in matrice piroclastica alternate a depositi piroclastici rimaneggiati. questa sequenza, riconducibile alla terza generazione di conoide, ha uno spessore di circa 15 m (vedi stratigrafia del sondaggio in fig. 4) e poggia (fig. 5) su di un 26 a. santo et al. fig. 4 stratigrafia da un sondaggio del comune di castellammare di stabia (reinterpretato); 1) materiale di riporto; 2) alluvioni ghiaioso-sabbiose; 3) sabbie vulcaniche grigiastre; 4) alluvioni sabbioso-ghiaiose; 5) pozzolane rimaneggiate; 6) tufo di colore giallastro; 7) sabbia grigiastra con abbondanti fibre vegetali; 8) pomici di colore bianco-giallastro; 9) sabbie grigiastre con abbondanti frammenti di conchiglie. stratigraphy from a selected borehole. 1) reworked material; 2) alluvial gravels and sands; 3) grey volcanic sands; 4) alluvial sands and gravels; 5) reworked pumiceous levels; 6) yellow tuff deposits; 7) grey sand rich of vegetal materials; 8) white-yellow pumiceous level; 9) grey sands rich of fragments of shells. 27pericolosità connessa a processi alluvionali ... livello di sabbie ed argille di ambiente transizionale e litorale che, come già evidenziato da cinque (1991), può essere correlato al cordone litorale bottaropioppaino datato 3600 anni bp. quest'ultimo elemento stratigrafico consente di confermare l’età storica di questa generazione alluvionale, testimoniando un'intensa e "recente" attività torrentizia con tassi di sedimentazione molto alti (circa 5mm/a negli ultimi 3000 anni) che è stata ulteriormente documentata con i dati della ricerca storica. coperture piroclastiche l’area oggetto di studio si presenta in gran parte ricoperta da una coltre di terreni piroclastici cineriticopomicei da caduta, spesso humificati e con spessori variabili, riconducibili prevalentemente all’eruzione vesuviana del 79 d.c. che distrusse ercolano, stabia e pompei e che ebbe un asse di dispersione dei prodotti vulcanici orientato verso se (rolandi, 1997). la presenza di questo manto piroclastico, relativamente impermeabile rispetto ai calcari, condiziona il rapporto infiltrazione-deflusso dei bacini idrografici che drenano l’area di studio e costituisce la maggiore fonte di materiale per il trasporto solido. al fine di valutare le reali caratteristiche di permeabilità dei terreni affioranti e di stimare gli areali di affioramento ed i volumi del materiale piroclastico presente sui versanti dei bacini idrografici, è stata redatta una carta delle coperture che illustra la distribuzione e gli spessori dei prodotti piroclastici (fig.1) dalla carta delle coperture si evince che nonostante i prodotti vulcanici siano stati storicamente rimobilizzati attraverso ripetute fasi di erosione e frane, sui versanti è ancora presente una notevole coltre di piroclastiti e di suolo ad esse associato. solo circa il 10 % dell’area di studio (tab.1) presenta calcari affioranti e sub affioranti, la restante parte è ricoperta da piroclastiti e suolo di natura sabbioso-limosa. esse, oltre a condizionare la franosità (di crescenzo & santo 1999), contribuiscono ad aumentare gli effetti del ruscellamento superficiale e quindi del trasporto solido nelle zone pedemontane. 44.. mmoorrffoommeettrriiaa ddeeii bbaacciinnii iiddrrooggrraaffiiccii ee ccaallccoolloo ddeeii tteemmppii ddii ccoorrrriivvaazziioonnee il territorio di castellammare di stabia (figg.1-2) è attraversato da numerosi corsi d'acqua (rivo san marco, cannetiello, san pietro, cognuolo, piazza grande, foiano e scurolillo) che scendono dai monti lattari e sfociano lungo il litorale stabiese e sono caratterizzati da un marcato regime torrentizio. la parte alta del bacino idrografico di questi torrenti è impostata sulla successione calcareo-dolomitica ricoperta dalla coltre piroclastica, mentre nei tratti più a valle incide i depositi di conoide alluvionale. per ogni bacino sono stati calcolati (tab.1) i principali parametri fisici e morfometrici utili per la determinazione del tempo di corrivazione: superficie, lunghezze delle aste principali, gradiente di pendio del collettore principale, quota massima, quota minima, quota media. lo studio delle caratteristiche morfometriche è stato condotto su carte topografiche 1/5.000. esso ha interessato bacini d'estensione variabile dai 35 km2 del san marco a meno di 1 km2 per i bacini minori, questi ultimi caratterizzati anche da un ordine gerarchico estremamente basso. per quanto riguarda la pendenza media, essa oscilla tra valori di 40 e il 50 % ad eccezione dei rivi maggiori (san marco, cannetiello, e san pietro) che presentano valori più bassi risentendo dei lunghi tratti pedemontani a bassa pendenza. in tab.1 sono stati inoltre riportati, per i singoli bacini, gli areali di affioramento del substrato calcareo. come si può notare, questi areali superano solo alcune volte il 10%. questo dato risulta importante se si tiene conto che in termini di coefficiente di infiltrazione potenfig. 5 sezione geologica mostrante i rapporti fra le diverse generazioni di conoidi: 1) depositi di spiaggia attuali; 2) depositi di conoide di iii generazione (età storica); 3) depositi transizionali e litorali (olocene); 4) depositi di conoide di ii generazione (pleistocene sup.); 5) depositi di conoide di i generazione (pleistocene medio); 6) calcari (cretacico sup.); 7) sondaggio; 8) faglia. geological cross-section showing the relationships between the different generations of alluvial fan deposits. 1) present day beach deposits; 2) alluvial fan deposits (third order, historical age); 3) littoral and transitional deposits (holocene); 4) alluvial fan deposits (second order, upper pleistocene.); 5) alluvial fan deposits (first order, middle pleistocene); 6) limestones; 7) borehole; 8) fault. 28 a. santo et al. ziale, e quindi in termini di rapporto infiltrazione/deflusso, si passa dai valori dei calcari pari al 100% a quelli delle piroclastiti che sono pari al 50% (celico, 1988). valori che verosimilmente, possono ancora ridursi in condizioni di intense precipitazioni orarie. in generale, quindi, in risposta alle precipitazioni, il ruscellamento superficiale risulta elevato perché i bacini sono in gran parte impostati sulla copertura piroclastica. per quanto riguarda i tempi di corrivazione (tab. 2), essi sono stati calcolati adottando quattro diverse formule (tropeano et al., 1996). dalla tabella si può evincere che i valori dei tempi di corrivazione sono in generale molto brevi, come d’altra parte risulta ovvio per le limitate dimensioni dei bacini e per gli elevati gradienti che li caratterizzano. questo dato, importante, evidenzia la “rapidità” dei potenziali eventi, che si traduce in una limitata possibilità di allertamento ed evacuazione della popolazione e che incide notevolmente sulle condizioni di rischio di questi bacini. 55.. rriicceerrccaa ssttoorriiccaa ssuullllee aalllluuvviioonnii cchhee hhaannnnoo ccoollppiittoo ccaasstteellllaammmmaarree ddii ssttaabbiiaa l’indagine storica è stata condotta attraverso la consultazione di una rilevante quantità di documenti rinvenuti presso l’archivio storico e la biblioteca comunale; l ’archivio storico della curia di castellammare di stabia e le emeroteche tucci e dell’università di napoli federico ii. essa ha portato alla luce preziosi documenti ed ha permesso di ricostruire e localizzare numerosi eventi alluvionali dei quali si era persa la memoria, nonchè di quantificare i diversi tipi di danni. gli eventi ricostruiti ed i relativi danni sono indicati in tab.3. di seguito verranno riportate solo alcune delle testimonianze storiche che, attraverso descrizioni puntuali, riescono a far capire quanto sia elevata la pericolosità geomorfologica in quest’area. eevveennttoo ddeell 11771155 in de rosa (1935) si legge: “un tratto della via che conduce al santuario di pozzano è attraversato dal torrente rivo del soccorso (rivo foiano) sul quale era un mal fermo ponte in legno che nel 1715 fu distrutto da una forte piena del rivo, sicché il transito ne rimase interrotto. i frati minimi, a proprie spese fecero ricostruire il ponte in muratura, su disegno dell’ing. g. lucchese. questo ponte esiste tuttora e dal 1715 ha resistito e resiste alle continue, violente e pericolose piene del rivo.” eevveennttoo ddeell 2200 ggeennnnaaiioo 11776644 nel verbale di una sessione capitolare, tenuta il 4 febbraio 1764, si narra che nella notte del 20 gennaio di detto anno, giorno seguente alla festività del santo protettore e vescovo catello, si scatenò, verso la mezzanotte, una terribile tempesta. dai monti vicini si rovesciò sulla città una grande quantità di acqua, che attraverso il rivo san pietro si riversò per le strade de turris, coppola, gesù e le altre vicine. ostruiti gli sbocchi al mare dai materiali trasportati dai torrenti, le acque salirono fino al secondo piano delle abitazioni. nel citato verbale si legge: “dai monti vicini cadde prolissa copia di acque sulla desolata città e con essa gran quantità di legnami svelti dalle radici nelle circostanti selve e come pure grandissima abbondanza di terreni, d’arena, d’argilla, di pietre e di macigni di grosso e grave diametro, che dopo tal terribile circostanza, si dovettero rompere adoperandosi le mine di polvere per ridurli a uso di fabbriche o di calcina.” una cronaca dettagliata del notaio vincenzo d’aiello conferma quanto già scritto e aggiunge altri particolari sull’accaduto. nel suo racconto si legge: “nelli paesi convicini vi sono morti una quantità di persone come gragnano, san ciro ed altri. in gragnano la parte di basso del trivione sono morte da cento e più persone affogate dalle acque ed oppressa dalle pietre delle proprie abitazioni cascateli addosso, portata via dall’acqua, e finora 20 del corrente ad ora 23 se ne sono ritrovate dei cadaveri dispersi per la campagna al numero 40.” a tal proposito, bisogna citare la relazione dell’architetto camillo ranieri, il quale nella pubblicazione del 1841 ricorda l’evento che colpì gragnano nel 1764, descrivendolo come una serie di scoscendimenti verificatisi tab 1 parametri morfometrici principali dei bacini analizzati; le superfici dei bacini sono calcolate sino alla sezione di chiusura. main morphometric parameters of the analysed drainage basins; the areas of the basin are calculated at the closing section. tab. 2 -tempi di corrivazione dei bacini studiati. per le sigle vedi tab.1. concentration times of the studied basin . for abbreviations see tab.1. bbaacciinnoo ss ss..ss.. ii ll hhmmaaxx hhmm hhoo ssccuurroolliilllloo 1,49 0.21 (14.3%) 39 2,5 1100 696 10 ffooiiaannoo 0,7 0.051 (7.3%) 49 1,4 820 503 15 pp.. ggrraannddee 0,38 0.038 (10%) 53 1 700 284 25 ccooggnnuuoolloo 0,6 0.07 (11.6%) 44 2,1 1050 617 25 ss.. ppiieettrroo 2,67 0.36 (13.6%) 28 4 1200 661 40 ccaannnneettiieelllloo 4,35 0.33 (7.7%) 21 5,7 1270 579 40 ss.. mmaarrccoo 30,3 2.6 (8.5%) 16 8,2 1425 701 70 ffoorrmmuullee aaddoottttaattee ggiiaannddoottttii ppeezzzzoollii ppuugglliissii vveennttuurraa 44 √ ss ++ 11,,55 ll 66ll 22//33 ((hhmmaaxx--hhoo)) 00,,112277 √ ss// √ii bbaacciinnoo –––––––––––––––––––––– 00,,005555 ll// √ii 00,,88 √ hhmm - hhoo ssccuurroolliilllloo 24,7’ 13,22’ 1h 06’ 15’ ffooiiaannoo 19,5’ 7’ 48’ 9’ ppiiaazzzzaa ggrraannddee 18,48 4’ 40,54’ 7’ ccooggnnuuoolloo 19,26 12,44’ 58,98’ 9’ ss.. ppiieettrroo 37,7 25’ 1h 25’ 23’ ccaannnneettiieelllloo 54,56 41’ 1h 46’ 37’ ss.. mmaarrccoo 1h 42’ 1h 12’ 2h 10’ 1h 52’ 29pericolosità connessa a processi alluvionali ... lungo il versante settentrionale del monte pendolo, causando 42 vittime. eevveennttoo ddeell 1144 oottttoobbrree 11887788 nell’archivio storico del comune di castellammare, c’è copia della relazione che l’allora sindaco scherillo inviò al prefetto del circondario in occasione dell’alluvione del 14 ottobre 1878. in questo documento è riportata la seguente cronaca dei fatti. “nella notte dal 13 al 14 corrente mese, dopo un lungo e cupo rumoreggiare di tuoni, e dopo vivissimo lampeggiare, una pioggia torrenziale scaricavasi nelle nostre pianure e sulle montagne del limitrofo comune di gragnano, e raccoltasi negli alvei dei rivi cannitello e san marco rompendo gli argini e straripando impetuosa invadeva le strade di questa città più vicine alla stazione e quelle dette surripa e san vincenzo travolgendo ogni ostacolo. case coloniche quasi sommerse, grida strazianti di intere famiglie che invocavano soccorso, colpi di fucile per richiamare gente ed avvertire nuovi pericoli, le vie, le botteghe quasi tutte abitate ripiene di acque e tab.3 eventi alluvionali e relativi danni. per l’ubicazione vedi fig. 6. alluvial events and related damages. for the location see fig. 6. aannnnoo nn.. uubbiiccaazziioonnee ddeessccrriizziioonnee ddaannnnii 11771155 1 altezza del santuario di pozzano piena del rivo foiano distruzione del ponte sul rivo 2 banchina circolo velico interrimento tunnel sbocco rivo s. pietro 3 via de turris ingenti danni 11776644 4 via coppola alluvionamento detritico-fangoso all’abitato 5 via del gesù 6 via mele 2 vittime e molti 11887788 7 vico minichiocchio alluvionamento fangoso h 1,5 m feriti, notevoli danni 8 stazione f.s. allagamento alle abitazioni e alla 9 via rispoli rete ferroviaria 10 via roma alluvionamento fangoso di 1-2 m cm 5 vittime, numerosi 11993355 11 corso v. emanuele interrimento dei seminterrati feriti, 3000 senzatetto 12 corso g. garibaldi e danni alle case, alla 13 stazione f.s. allagamento rete stradale e alla 14 piazza grande alluvionamento fangoso h 1 m stazione ferroviaria 11994499 15 via tavernola alluvionamento fangoso h 1,5 m danni ai seminterrati 16 salita quisisana frana scorrimento crollo 17 via bonito alluvionamento fangoso 18 s. caterina alluvionamento fangoso h 1,80 2 banchina circolo velico interrimento sbocco tunnel rivo s. pietro 19 via bonito alluvionamento fangoso fino ai primi piani delle case 20 tra via s. caterina e via bonito interrimento sottopossaggio 21 via bonito alluvionamento fangoso 5 feriti e 50 persone 22 piazza fontana grande alluvionamento fangoso h 1,5 m sgomberate, ingenti 11998877 23 via duilio alluvionamento fangoso h 0,8 m danni al centro 24 via acton alluvionamento fangoso h 1 m storico con 25 via acton (rivo foiano) interrimento tunnel interruzione della 26 via acton ex pensione teta alluvionamento detritico-fangoso h 1 m s.s. 145 e di via 27 piazza grande alluvionamento detritico action 28 letto rivo cognuolo altezza via fratte alluvionamento detritico-fangoso 29 via fratte interrimento tunnel 30 rivo piazza grande altezza via fratte frana per scalzamento al piede 31 dx orografica rico foiano nei pressi di via salita di pozzano frana scorrimento-crollo 32 via delle terme 22000000 33 via s. caterina alluvionamento fangoso danni ai seminterrati di melma fino ad oltre un metro di altezza. i danni sono gravissimi ed intere famiglie perdettero tutto quel poco che costituiva la loro fortuna, rimanendo prive anche dei letti trasportati dalle acque.” nel resoconto sull ’accaduto dell ’al lora commissario vincenzo oliva, si legge: “nella notte di domani a lunedì 14 ottobre verso il tocco p.m. una piena smisurata si verificava sul canale che divide il fondo di de rosa dalla fabbrica d’alcool fusco sulla strada che mena al camposanto. in un baleno le acque sormontarono il muro di cinta ed abbattevano gli argini, irrompendo furiosamente come mare in tempesta, ed in men che non si pensa allagava tutta la circostante campagna, precipitando dalla parte di castellammare che dalla suddetta fabbrica fusco giunge fino al quartuccio. un panico generale spargeasi tosto per la città, alcune case rurali venivano abbattute alcune altre circondate da per ogni dove dalle acque rimanevano bloccate in balia degli eventi. le tre strade di castellammare, via napoli, marina, vittorio emanuele, presentavano tre mari vorticosi che facevano orrore alla semplice vista, orrore e spavento maggiore perché nel mezzo della notte.” sempre nel già menzionato archivio c’è la relazione, degli ing. g. vitelli e g. vanacore, sui danni provocati dall’alluvione. i due tecnici fanno una dettagliata descrizione e scrivono che dalla strada nocera (all’altezza del ponte san marco) fino a via napoli “furono danneggiati dall’alluvione ettari quattro ed are 88 circa di terreno, con restare su quella superficie uno strato di lapillo ed arida sabbia dell’altezza di metri 0.60.” altri fondi, bassi, magazzini e abitazioni furono coinvolti dalla furia delle acque in via napoli, via marina e nelle strade vicine, “la lava ha depositato uno strato di sabbia frammista a pietre calcaree e lapillo dell’altezza media di metri 0.80, abbattendo e distruggendo una gran quantità di alberi e viti.” in questa relazione è fatto riferimento anche il rivo san pietro che, rispetto al rivo cannitello e al rivo san marco, ha causato danni minori, “l‘altro torrente denominato san pietro per dove hanno scolo le pluviali acque che sogliono derivare dalle montagne del sovrastante comune di pimonte, nell’alluvione in parola raccolse pure le abbondanti acque che derivarono dalla strada provinciale gragnano castellammare. il volume dell’acqua non capendo nell’alveo di quel torrente straripò inondando la strada surripa, poi quella di santa maria dell’orto, largo quartuccio e largo principe umberto, lasciando su quei pavimenti molto fango e materiale.” nell’emeroteca della biblioteca universitaria abbiamo trovato alcuni giornali contemporanei degli eventi descritti. dalle cronache riportate sul quotidiano “roma” del 15 ottobre 1878 si apprende che: “verso la mezzanotte di domenica (13 ottobre) sulle montagne di gragnano e limitrofi territori avvenne una pioggia dirotta. la pioggia non potette contenersi nell’alveo dei rivoli san marco e san pietro, e straripava inondando il lato nord-est della città di castellammare, travolgendo seco quanto invadeva, ed atterrando tutti gli ostacoli che incontrava. le masserie coloniche della contrada tavernola furono gravemente danneggiate, e la corrente prese la strada di nocera, dividendosi in due, l’una invase la piazza principe di napoli e la strada napoli, l’altra, atterrando le mura del fondo trojano, per la strada camposanto atterrava i muri del giardino fusco e fondo cannodanicello, ed allagava varie case coloniche ove erano parecchie famiglie. le acque eran dal suolo elevate oltre un metro. di vittime se ne accennano a due, sarebbero due fanciulli.” dallo stesso quotidiano, il 17 ottobre 1878, si legge: “a memoria d’uomini non si ricorda un disastro così spaventevole. i danni sono gravissimi: intere famiglie perdettero tutto quel poco che costituiva la loro fortuna. finora si ha notizia di una sola vittima un fanciullo di nove anni – ma si teme sempre che giungano particolari dolorosi.” eevveennttoo ddeell 2200 aaggoossttoo 11993355 verso l’imbrunire del 20 agosto 1935, per violenti rovesci temporaleschi, accompagnati, localmente, dallo straripamento del rivo san marco, la zona orientale della città di castellammare di stabia fu colpita da una terribile alluvione, seguita dal tragico bilancio di cinque vittime trai quali tre bambini; più di trecento furono poi i senzatetto. anche il vicino comune di gragnano, dovette far fronte al triste epilogo dell’evento alluvionale, compiangendo altre cinque vittime e fronteggiando la richiesta d’aiuto delle numerose famiglie alluvionate. le cronache dei quotidiani dell’epoca (il mattino, 1935) descrivono un violento nubifragio che interesso l’area dei monti lattari con flussi fangosi che invasero le strade della città di amalfi e la parte più orientale dell’abitato di gragnano (piazza della conceria), ma soprattutto l ’al luvione colpì la contrada tavernola a castellammare di stabia “......da gragnano,..., è affluita su castellammare una valanga di acqua che ha trascinato lapilli masserizie, pietre, tronchi d’alberi. ...” .( il mattino, 22.08.1935 ) in una lettera inviata all’alto commissario per la provincia datata 24/9/1935, l’allora podestà del comune di castellammare di stabia, catello de simone, descriveva scrupolosamente gli effetti del disastro fornendo preziosissime indicazioni che ci hanno permesso di definire i dettagli dell’alluvione. da questa si evince che: la zona più fortemente colpita si presentava a forma triangolare estendendosi tra la foce del torrente san marco, il ponte dello stesso sulla strada provinciale per nocera e la foce del rivo cannetiello. all’interno di questa zona, gli scantinati furono completamente invasi dall’acqua che portava in sospensione materiale argilloso e lapillo, mentre una corrente di materiale limaccioso, imperversava per le strade con un’altezza variabile da 2 a 0.5 m. lasciando un residuo solido dello spessore medio di un metro. tutti i piani terra furono dunque preda della fanghiglia e a stento alcune famiglie fecero in tempo a cercare scampo ai piani superiori. fuori di tale zona si verificarono allagamenti con strade e terreni ricolmati, per uno strato vario di alcune decine di cm., di terra rimaneggiata di natura limosa e di piccoli ciottoli. un’ulteriore testimonianza è raccolta da palumbo (1940) che nella sua antologia storica di stabia e castellammare di stabia recita : “la muraglia fangosa procedeva travolgente, distruttrice, dilagando con impeto contro i muri dei fabbricati e facendo larghi e vorticosi gorghi al centro delle piazze, mentre erano trascinati tronchi d’albero, carretti, sterpi, mobili strappati a terranei e baracche d’abitazione, lastroni di asfalto smossi dal piano stradale delle vie percorse e rottami di ogni genere”. 30 a. santo et al. eevveennttoo ddeell 99 nnoovveemmbbrree 11998877 il pomeriggio del 9 novembre 1987, un forte nubifragio si scatenò sulla campania, colpendo molti centri della provincia di napoli e lasciando ferite profondissime nel territorio comunale di castellammare di stabia. l’indomani del triste evento, il quotidiano napoletano il mattino, apriva la sua pagina di cronaca con un articolo intitolato “il giorno del diluvio”. in esso, il giornalista antonio pane descriveva i luoghi del disastro, annotando 50 persone sgomberate e 5 ricoverate in ospedale per sindrome da assideramento. da una ricostruzione fatta attraverso documenti giornalistici, comunali e testimonianze dirette, la zona più danneggiata è risultata il vecchio sobborgo marinaro di castellammare, tra le vie santa caterina e bonito; qui, tutte le abitazioni furono invase dall'acqua che raggiunse circa i 2 metri d'altezza, come testimoniato dalla traccia del flusso fangoso sui muri. in quest'area, il materiale fangoso misto a detrito e quant'altro trasportava la corrente ha prima occluso il tratto sotterraneo del rivo cognuolo, per poi intasare il passaggio pedonale sotto i palazzi tra via s. caterina e via bonito che costituiva la via preferenziale del deflusso superficiale. tutto ciò ha generato quello che possiamo definire un "effetto diga", che ha spinto l'acqua verso vie di fuga laterali ed attraverso l'abitazione al primo piano sopra al citato sottopassaggio. in questo scenario numerose persone rischiarono la vita, ed in particolare alcuni anziani rimasero bloccati nelle loro abitazioni e furono soccorsi semi assiderati. l’intera popolazione dovette fronteggiare ingenti disagi con la città paralizzata per la gran quantità di detriti riversatisi nelle strade, inoltre piccole frane danneggiarono e ostruirono le sedi stradali della statale sorrentina e della via action, interrompendo le uniche vie di comunicazione da e per i centri costieri sorrentini. le forze di soccorso, per lo più militari, giunte nelle ore successive trovarono uno scenario catastrofico, infatti, il flusso fangoso, oltre a colmare i bassi, si era riversato per le strade lasciando fango, tronchi d’albero e massi di grandi dimensioni. le tracce del passaggio del flusso furono visibili per diversi giorni dall’evento con i muri imbrattati di fango per un’altezza, rispetto al livello stradale, variabile dai 50 cm fino ai 2 m nella zona più fortemente colpita. eevveennttoo ddeellll’’ 88 oottttoobbrree 22000000 l'ultimo evento della ricerca storica riguarda l'episodio che nel pomeriggio dell'8 ottobre 2000 fece rivivere nell'abitato di castellammare di stabia le scene dell'alluvione dell'87. dai quotidiani e da testimonianze locali si apprende che, a causa di mezz'ora di pioggia, il rivo fratte ha riversato in via santa caterina circa duemila metri cubi di fango, che hanno invaso i locali al piano terreno dei palazzi, inducendo gli abitanti ad abbandonare le proprie abitazioni per rientrarvi solo a tarda sera. a tal proposito il mattino del giorno 9 titolava "mezz'ora di pioggia e torna l'incubo frane; fiume di fango nel centro storico di castellammare". la ricerca storica ha dunque evidenziato che nell’area di castellammare si sono ripetuti con una certa frequenza fenomeni di alluvionamento con ricorrenza di almeno di 50 anni. tutti i fenomeni vengono descritti come piene improvvise, con riposte alle precipitazioni, in termini di tempo, molto brevi. il materiale che ha invaso la città viene descritto in generale come una massa fangosa, molto fluida che ha invaso le case per 1-2m di altezza, arrivando in alcuni casi sino al primo piano delle abitazioni. in alcuni casi le masse fangose hanno trascinato grandi blocchi di calcare e tronchi di alberi che hanno sfondato alcune case. i risultati, in termini di danni, sono rappresentati da diverse vittime, case distrutte e numerose abitazioni e strade invase dal fango. 66.. ccaarrttaa ddeeii ddaannnnii rriiccaavvaattaa ddaallllaa rriicceerr-ccaa ssttoorriiccaa ee rreellaazziioonnii ttrraa ii ffeennoommeennii ddii aalllluuvviioonnaammeennttoo ee llee mmooddiiffiiccaazziioonnii aannttrrooppiicchhee ddeell rreettiiccoolloo iiddrrooggrraaffiiccoo questa carta (fig. 6) riassume i dati della ricerca storica a partire dal 1715; le aree colpite sono state distinte con colori diversi in funzione dei diversi eventi alluvionali. chiaramente, le notizie relative ai danni sono più dettagliate e precise per gli ultimi eventi, specie per quello del 1987. dalla lettura della carta dei danni si evince che, negli ultimi trecento anni, l'abitato di castellammare di stabia è stato ripetutamente interessato da eventi di tipo alluvionale e che alcune zone, in prossimità dei torrenti maggiori, risultano colpite più volte. l’analisi di carte topografiche dell’area edite tra il 1872 ed il 1990 ha evidenziato che le modificazioni indotte sui bacini idrografici dalla continua urbanizzazione, hanno condizionato le caratteristiche idrologiche dei corsi d’acqua in diversi modi. innanzitutto, una percentuale sempre maggiore di superficie è stata resa impermeabile all’infiltrazione delle acque a causa della crescente cementificazione, provocando l’aumento del ruscellamento superficiale e riducendo il tempo di concentrazione. in altri casi è stata ristretta la naturale luce degli alvei (ponti, sottopassi) e spesso, non si è tenuto conto delle distanze di rispetto, relative alle aree di possibile esondazione. non è scopo di questo lavoro entrare nel merito dell’espansione urbanistica o delle modificazioni di tipo idraulico, ma la ricerca dei depositi e delle forme recenti da attribuire a fenomeni di alluvionamento non poteva prescindere, in un’area così fortemente urbanizzata, dalla ricostruzione e dalla modificazione antropica dei naturali corsi d'acqua. a tale scopo si è rivelato utile reperire riferimenti cartografici coevi agli eventi alluvionali studiati attraverso il confronto di una serie di carte topografiche in sequenza cronologica, in particolare (fig.7) : • rappresentazione topografica risalente al 11881122 • tavola della città ad opera di f. fantacchiotti del 11887755 • tavoletta topografica dell’i.g.m. 1/25.000 del 11990099 • tavoletta topografica dell’i.g.m. 1/25.000 del 11995544 • carta topografica del comune 1/10.000 del 11999900 dall’osservazione dell’antica rappresentazione della città, risalente al 1812 (fig.7), si nota che l’abitato di castellammare di stabia era limitato al tratto costiero compreso tra il cantiere navale e tutta la conoide del rivo san pietro. in questa carta i tratti terminali dei rivi san pietro, cognuolo e piazza grande risultano scorrere al di sotto dell’antico centro urbano, mentre si presen31pericolosità connessa a processi alluvionali ... ta inalterato il percorso degli altri rivi. questa carta è stata usata anche come riferimento per l’interpretazione dei danni causati dall’alluvione del 20\1\1764. dalla carta dei danni risulta che l’area colpita da questa alluvione è circoscritta solo alla conoide del rivo san pietro. questo, però, non esclude che anche gli altri rivi siano stati interessati da intensi fenomeni di trasporto torrentizio, dato che all’epoca l’abitato di castellammare, come già evidenziato, aveva dimensioni molto più limitate rispetto a quelle attuali. nel periodo fine ottocento inizio novecento la città, così come appare nella riproduzione dell’architetto f. fantacchiotti e nella tavoletta i.g.m., (fig.7) risulta estesa verso nord occupando gran parte della conoide del rivo cannitello, e una ristretta fascia costiera fino allo sbocco del rivo s.marco. dalle due carte si osserva che l’ultimo tratto del rivo cannetiello a partire dalla via roma è tombata. la carta del fantacchiotti offre una rappresentazione della città al 1875, pochi anni prima dell’evento alluvionale del 1878, ed è stata per questo utilizzata come supporto per la localizzazione dei danni, essendo cambiata, nel corso degli anni, la toponomastica delle strade. dall’osservazione della distribuzione dei danni si può osservare che le zone colpite dai rivi san marco, cannitello e san pietro corrispondono a quasi tutto il territorio allora urbanizzato; non si può ovviamente escludere che l’area alluvionata fosse molto più ampia. un “flash fotografico” della situazione nel dopoguerra, possibile grazie alla carta del 1954, mostra un ulteriore sviluppo urbanistico, che interessa completamente la conoide del rivo cannitello e parte di quella in sinistra orografica del rivo s. marco. anche in questo caso si è riscontrata una certa corrispondenza tra l’espansione urbanistica e le modificazioni subite dai corsi d’acqua. infatti, il tratto tombato del rivo cannitello è stato esteso fino all’apice della conoide mentre il rivo san marco è stato canalizzato nel tratto che va dalla strada ferrata alla spiaggia (vedi carta 1954). dalle notizie rinvenute dalla ricerca storica, è possibile affermare che la conoide del rivo san marco era già parzialmente urbanizzata quando si verificò la terribile alluvione del 20 agosto 1935. infatti, dalla carta dei danni risulta che la zona più fortemente colpita era quella in sinistra orografica del rivo san marco, mentre nella parte destra non sono stati riportati danni essendo questa poco urbanizzata e destinata ad uso agricolo (vedi carta 1954). 32 fig. 6 carta dei danni relativa agli eventi alluvionali succedutesi dal 1715 ad oggi nell'area di castellammare di stabia. i numeri si riferiscono alle località citate nella tab. 3. map showing the damages produced by the alluvial events occurred since 1715 in the area of castellammare di stabia. the numbers refer to the localities of tab.3. a. santo et al. 33 fig. 7 carte storiche (1812-1990) rappresentanti l'evoluzione urbanistica e le modificazioni antropiche della rete idrografica. a) alvei naturali; b) tratti di alvei tombati o cementati. nella carta topografica del 1990 i colori indicano lo sviluppo del centro urbano nel tempo. historical maps (1812 –1990) showing the urban evolution and the anthropic modifications of the hydrographic network. a) natural river-bed; b) modified river-bed. in the 1990 topographic map the colours represent the development of urban area during time. pericolosità connessa a processi alluvionali ... per la situazione urbanistica attuale e per l’alluvione del 1987, si fa riferimento alla carta del 1990, questa è stata usata anche come base cartografica per sintetizzare l’evoluzione urbanistica e le modificazioni subite dai rivi nel tempo. nella rappresentazione dell ’abitato di castellammare di figura 7, si evince che negli ultimi decenni si è avuta una notevole espansione urbanistica verso la piana del sarno e lungo la fascia pedemontana. i rivi che hanno risentito maggiormente di questo ulteriore sviluppo sono il san marco, che è stato totalmente tombato al di sotto dell’abitato ed il cannitello il cui tratto tombato é stato esteso dalla paleofalesia alla statale ss. 145. esempi dell'intensa modificazione antropica subita dalla rete idrografica negli ultimi anni sono: la costruzione del fabbricato ex pensione teta, che occupa il letto del rivo scurolillo in prossimità della foce; le gallerie anas realizzate lungo la ss 145, perpendicolarmente al rivo foiano (fig. 8). queste costituiscono un sito di particolare rischio; infatti, nel gennaio del 1997, una di esse è stata già invasa da una colata rapida di fango (frana di pozzano, di crescenzo & santo, 1999). in conclusione tutti i rivi hanno dato nel passato problemi di trasporto solido per alluvionamento, in occasione dei quali hanno avuto un ruolo fondamentale le numerose restrizioni delle sezioni fluviali, riconducibili alle modificazioni antropiche dei naturali corsi e all'occlusione delle tombature con cui i rivi raggiungono il mare. 77.. rreellaazziioonnii ttrraa pplluuvviioommeettrriiaa eedd eevveennttii aalllluuvviioonnaallii la piovosità nell’ambito della penisola sorrentina, (rossi & villani, 1994; de falco et al, 1997) presenta una distribuzione disomogenea, in quanto risulta condizionata dalla particolare configurazione morfologica dei monti lattari; questi rilievi costituiscono una barriera orografica che influenza in modo diverso le precipitazioni sui due versanti, inducendo una maggiore concentrazione degli eventi meteorici nel periodo invernale sul versante sorrentino e nel periodo autunnale su quello amalfitano. questa variabilità è ulteriormente confermata dall’analisi dei dati pluviometrici della serie storica 1921-1990, che ha permesso a rossi & villani (1994) di suddividere in due sottozone pluviometriche l’area penisola sorrentina-monti lattari. inoltre, in base all’analisi dei dati pluviometrici medi annui relativi allo stesso periodo, de falco et al., (1997) hanno redatto la carta delle isoiete che mostra valori più elevati nel settore tra nocera, gragnano e positano, posto a quota maggiore, all ’ interno del quale ricade anche i l territorio di castellammare di stabia (fig. 9) . per quanto riguarda i dissesti che frequentemente colpiscono la penisola sorrentina, questi hanno un rapporto di causaeffetto con gli eventi meteorici che è ampiamente documentato in letteratura dall’analisi delle isoiete di alcuni eventi pluviometrici del passato e della serie storica delle frane. per l'analisi delle relazioni tra pluviometria ed eventi alluvionali che hanno interessato i bacini idrografici di nostro interesse, sono stati analizzati i dati relativi ai pluviometri di castellammare (18 m s.l.m.) e gragnano (173 m s.l.m.) reperiti dagli annali idrologici dell’istituto idrografico e mareografico di napoli. in particolare sono stati considerati i valori di pioggia giornaliera superiore agli 80 mm nel periodo 1935-1988 (fig.10). il confronto con gli episodi alluvionali noti, purtroppo, è stato possibile solo per gli eventi del 20 agosto 1935 e del 9 novembre 1987; per essi sono stati considerati i valori di pioggia giornalieri e la pioggia cumulata per un periodo, antecedente di circa tre mesi. nel caso dell’alluvione del 1935, che fa riferimento al rivo s. marco il cui bacino idrografico ricade nell’area di competenza del pluviometro di gragnano, si sono verificati, dal 1° giugno al 20 agosto, solo otto giorni piovosi con un valore di pioggia cumulata di 116 mm, cui si sono aggiunti i 94 mm del giorno 20 (fig. 10). per quanto concerne l’evento del 1987, l’eccezionale pioggia di 182 mm del 9 novembre è stata preceduta da soli 137,6 mm di pioggia cumulata nei tre mesi antecedenti. entrambi gli eventi, dunque, si sono verificati dopo un periodo di scarse precipitazioni, in coincidenza di un picco piovoso isolato di tipo temporalesco. dal grafico in fig.10, si evince inoltre che valori di precipitazioni giornaliere simili a quelli registrati per gli eventi alluvionali del 1935 e del 1987 si sono ripetuti più volte senza effetti degni di rilievo. tali considerazioni, anche se prive di valore quantitativo, inducono a pensare che gli eventi alluvionali potrebbero essere stati causati da una particolare concentrazione oraria delle piogge. ciò si intuisce dal contenuto di alcuni documenti rinvenuti nella ricerca storica come la descrizione coeva dei fatti del notaio vincenzo d’ayello jr.; “ temporale o sia tempesta grande sortita nel 20 gennaio 1764 …principiata verso l’ore sette ed aumentata sino alle ore 11”., dalla relazione tecnico-sanitaria del municipio del 5/09/1935: all’imbrunire del 20 agosto e per non più di un ora si scatenò un violentissimo nubifragio. 34 fig. 8 ingresso della galleria anas in costruzione che attraversa il vallone di foiano. sulla sinistra sono ben evidenti i depositi di conoide alternati a livelli piroclastici tardo pleistocenici. the building tunnel that crosses the foiano creeck. on the left are exposed alluvial fan deposits with intercalation of upper pleistocene pyroclastic levels. a. santo et al. 35 fig. 10 a) istogramma delle massime precipitazioni giornaliere (> 80 mm) registrate dai pluviometri di castellammare mare di stabia e gragnano nell'intervallo 1935-88. b) piogge giornaliere registrate dalla stazione pluviometrica di gragnano nei tre mesi antecedenti l'evento del 20/08/1935 c) piogge giornaliere registrate dal pluviometro di c\mare di stabia nel periodo antecedente l'evento alluvionale del 09/11/1987. a) histogram of maximum daily rainfall (> 80 mm) recorded from rain-gauges of castellammare and gragnano between 1935 and 1988. b) daily rainfall recorded from rain-gauge of gragnano during the three months before the event of the 20/08/1935. c) daily rainfall recorded from rain-gauge of castellammare di stabia before the alluvial event of 9/11/1987. fig. 9 carta delle isoite della penisola sorrentina-monti lattari. (da de falco et al, 1997, modif.) isoiete map of the surrentine peninsula – lattari mts. (from de falco et al., 1997, modified). 88.. ccoonncclluussiioonnii lo studio geologico-geomorfologico ha evidenziato che una estesa porzione dell ’abitato di castellammare è localizzata su conoidi oloceniche accresciutesi anche in età storica. la ricerca storica condotta ha permesso di documentare numerosi eventi alluvionali di cui si era persa la memoria dalla fine del settecento ad oggi, di localizzare e distinguere i danni relativi ai singoli eventi e di redigere una carta dei danni in cui sono evidenziate le aree colpite da uno o più eventi alluvionali, nel periodo che va dal 1764 al 1987. tale carta è stata ricostruita valutando anche l’evoluzione urbanistica dell’area, utilizzando riferimenti cartograpericolosità connessa a processi alluvionali ... fici coevi agli eventi alluvionali studiati; in particolare sono state utilizzate carte risalenti rispettivamente al 1812, 1875, 1909, 1954 e 1990, allo scopo di correlare i danni all’evoluzione urbanistica. da questo confronto è emerso che sicuramente eventi della stessa intensità, potrebbero interessare aree maggiori, vista la notevole espansione urbanistica e l’alta densità demografica di questo territorio. dalle stesse carte è stato possibile seguire nel tempo le modificazioni antropiche subite dai “rivi” (alvei tombati, cementificazione, restringimento ecc.). inoltre, dalle notizie storiche sulle alluvioni, si è potuto accertare che i punti di esondazione sono stati talvolta localizzati in corrispondenza dei restringimenti d’alveo (“effetto diga” causato da tronchi e massi trasportati dalla corrente ). l’analisi storica e l’analisi dei dati pluviometrici disponibili suggeriscono che gli eventi si sono verificati in coincidenza di picchi piovosi isolati. la particolarità di queste precipitazioni va ricercata nella loro concentrazione oraria, che purtroppo non può essere quantificata a causa della mancanza di dati pluviometrici, ma che trova conferma nelle minuziose descrizioni degli eventi rinvenute nella ricerca storica. lo studio dei bacini idrografici ha consentito di definire i principali parametri fisici che li caratterizzano e di calcolare il loro tempo di corrivazione che si è dimostrato essere sempre prossimo o inferiore all’ora. sulla base dei dati raccolt i nel territorio di castellammare di stabia si devono quindi evidenziare le condizioni di alta velocità e pericolosità dei fenomeni alluvionali che in un’area così altamente urbanizzate si traducono in un elevato rischio. molti altri centri abitati campani presentano le stesse caratteristiche avendo condizioni geologico-geomorfologiche predisponenti a tali fenomeni quali: condizioni morfometriche dei bacini e cioè gradienti medi di pendenza abbastanza elevati (30 40 %) ed elevata energia di rilievo (1000 metri di dislivello su bacini di dimensioni estremamente ridotte), associati a bassi tempi di corrivazione; estesa presenza di coperture piroclastiche sui versanti dei bacini idrografici che favoriscono il ruscellamento superficiale e contribuiscono ad aumentare il trasporto solido degli alvei. in questi contesti, gli studi multidisciplinari rivolti alla mitigazione del rischio per fenomeni di alluvionamento, devono tener conto di un approccio geologicogeomorfologico di dettaglio, atto alla individuazione dei conoidi attivi, accompagnato da una accurata ricerca storica soprattutto perché quest’ultima ha mostrato più volte (migale & milone 1998) così come per le frane, che i fenomeni alluvionali possono ripetersi con tempi di ritorno non necessariamente brevi (dell’ordine dei 50100 anni) che spesso hanno fatto dimenticare all’uomo le condizioni di alto rischio di alcuni territori. rriinnggrraazziiaammeennttii gli autori desiderano ringraziare il prof. sorriso valvo per gli utili consigli nella revisione critica del manoscritto. lavoro stampato con fondi ex murst 60% e 40%. resp. prof. de riso r. llaavvoorrii cciittaattii aucell i a., cinque a. & merola d., (1996) discriminazione cronologica di eventi deformativi fragili lungo il margine settentrionale dei monti lattari sulla base di dati geologici e geomorfologici. il quaternario, 99 (1), 319-324. archivio storico di castellammare relazioni tecnicoamministrative. municipio di castellammare di stabia, napoli. barra d., bonaduce g., brancaccio l., cinque a., ortolani f., pagliuca s. & russo f. (1989) nuovi dati sulla evoluzione geomorfologica olocenica della piana costiera del fiume sarno (campania). atti conv. soc. geol. it.. "morfogenesi e stratigrafia dell'olocene" 55, 23-30 bonardi g., d'argenio b. & perrone v. (1988) carta geologica dell'appennino meridionale in scala 1: 250.000. mem. soc. geol. it., 4411. budetta p. & santo a. (1993) morphostructural evolution and related kinematics of rockfalls in campania (southern italy): a case study. engineering geology, 3366 (3/4), 197-210. budetta p., calcaterra d. & ducci d. (1991) caratterizzazione geomeccanica di ammassi rocciosi carbonatici tra castellammare di stabia e vico equense (penisola sorrentina campania). geologia tecnica, 33/91, 13-22, roma. budetta p., calcaterra d. & santo a. (1994) engineering-geological zoning of potentially unstable rock slopes in sorrentine peninsula (southern italy). proc. 7th int. congr. i.a.e.g., lisbona, 2119-2126, balkema. calcaterra d., santo a., de riso r., budetta p., di crescenzo g., franco i., galietta g., iovinelli r., napolitano p. & palma b. (1997) fenomeni franosi connessi all’evento pluviometrico del gennaio 1997 in penisola sorrentina-monti lattari: primo contributo – atti ix congresso nazionale dei geologi, roma 17-20 aprile 1997. celico p. (1988) – prospezioni idrogeologiche – liguori ed., napoli. celico p., guadagno f.m. & vallario a. (1986) proposta di un modello interpretativo per lo studio delle frane nei terreni piroclastici. geol. appl. idrogeol., 2222, 73-193. celico p., guadagno f.m. (1998) l'instabilità delle coltri piroclastiche delle dorsali carbonatiche in campania: attuali conoscenze. quaderni di geologia applicata, 55 1. cinque a. alinaghi h., laureti l., russo f., (1987) osservazioni preliminari sull'evoluzione geomorfologica della piana del sarno (campania, appennino meridionale). geogr. fis. din. quat., 1100 , 161-174. cinque a., 1991 la trasgressione versiliana nella piana del sarno (campania). geogr. fis. din. quat., 1144 (1991), 63-71. civita m. & lucini p. (1968) sulla franosità nella zona nord-occidentale della penisola sorrentina (campania). mem. e note dell'ist di geol. appl., 1100, 7-58. civita m., de riso r., lucini p. & nota d'elogio e. (1975) sulle condizioni di stabilità dei terreni della penisola sorrentina (campania). geol. appl. e idrogeol., 1100, 129-188. 36 a. santo et al. cotecchia v. & melidoro g., (1966) geologia e frana di termini-nerano. (penisola sorrentina). geol. appl. e idrogeol., 11. 93-122. de falco m., de riso r., lucini p. & nota d'elogio e., (1997) la piovosità della penisola sorrentina e dei monti lattari in relazione all 'evento del gennaio 1997. atti ix congr. ordine naz. geologi, 17-20 roma deino a.l., curtis g.m., southo j., terrasi f., campajola l., orsi g., (1994) c14 and ar40/ar39 doting of the campanian ignimbrite, phlegraean fields, italy. 8th international conference on geochronology, cosmochrondology and isotope geology, berkeley, usa, abstracts, us geol. surv. circ. 1107, p.77. del prete s., mele r., (1999) lo studio della franoisità storica come utile strumento per la valutazione della pericolosità da frane. un esempio nell'area di gragnano (campania). boll. soc. geol. it., 111188 , 91-111. de riso r. (1992) le frane in roccia della penisola sorrentina. in vallario a. (1992) frane e territorio (le frane nella morfogenesi dei versanti e nell'uso del territorio). liguori editore. de riso r., budetta p. calcaterra d. & santo a. (1999) le colate rapide in terreni piroclastici del territorio campano. convegno su "previsione e prevenzione di movimenti franosi rapidi", trento 17-19 giugno 1999, geam. de riso r. & nota d'elogio e. (1973) sulla franosità della zona sud-occidentale della penisola sorrentina (campania). mem. e note ist. geol. appl., 1122, 5-46. de rosa t. (1935) castellammare di stabia, rievocazioni e rivendicazioni storiche. pada tipografia santuario basilica1935. di crescenzo g. & santo a. (1999) analisi geomorfologica delle frane da scorrimento-colata rapida in depositi piroclastici della penisola sorrentina (campania). geogr. fis. din. quat., 2222, 57-72 . giasi c.i., guadagno f.m. & mele r. (1996) alcuni aspetti delle fenomenologie franose nelle coperture piroclastiche dei versanti di monte pendolo (gragnano, na). atti vi conferenza scientifica annuale sulle attività di ricerca dei dipartimenti, giornate poster sulle ricerche del gruppo geomineralogico, univ. di napoli, 66-68. guadagno f. m. (1991) debris flows in the campanian volcaniclastic soils (southern italy). proc. int. conf. on "slope stability engineering developments and applications", isle of wight, 109-114. guadagno f. m., palmieri m., siviero v. & vallario a. (1998) alcuni aspetti degli eventi franosi di tipo colata in vulcanoclastiti incoerenti nell'area campana. 74° cong. soc. geol. it. guida m., iaccarino g. & vallario a. (1974) alcune considerazioni sui fenomeni di dissesto e sulla difesa del suolo nella penisola sorrentina. geologia tecnica, 22, 120-128. guida m., pagano d. & vallario a., (1986) i fenomeni franosi della penisola sorrentina. in: cinque a. (1986) guida alle escursioni geomorfologiche. (penisola sorrentina, capri, piana del sele e monti picentini). 69-90, pubbl. n° 3333, dip. scienze della terra, università di napoli. istituto geografico militare: carte topografiche storiche. istituto idrografico e mareografico: annali del servizio idrografico il mattino (22/08/1935) biblioteca università federico ii (napoli), sez. emeroteca. il mattino (10/11/1987) emeroteca tucci, posta centrale (napoli). il mattino (9/10/ 2000). lazzari a., (1954) aspetti geologici dei fenomeni verificatisi nel salernitano in conseguenza del nubifragio del 25-26 ottobre 1954. boll. soc. dei naturalisti in napoli, 6633. migale l. & milone a. (1998): "ricerca storica sulle colate di fango in terreni piroclastici della campania". rassegna storica salernitana, 30, 235-271. montella n. (1841) sposizione del disastro avvenuto in gragnano diretta ad allontanare il timore di nuovi pericoli. tip. del petrarca napoli. palumbo m. (1940) stabia e castellammare di stabia, antologia storica. aldo fiory editore napoli. parisi g., (1842) cenno storico-descrittivo della città di castellammare di stabia. firenze 1842. penta f., lupino o. r., capozza f. & esu f. (1954) effetti dell'alluvione del 26 ottobre 1954 nel salernitano. geotecnica, 11. ranieri n. (1841) sul funesto avvenimento della notte del 21 al 22 gennaio 1841 nel comune di gragnano. boenzio, napoli, pp. 2-16, tavv. n° 2. rolandi g. (1997)the eruptive history of sommavesuvius volcanism and archeology in mediterranean area. ed. de vivo & cortini. roma (15-17/10/1878) biblioteca univ. federico ii (napoli), sez. emeroteca. rossi f., villani p. (1994) valutazione delle piene in campania. g.n.d.c.i previsione e prevenzione degli eventi idrologici estremi e loro controllo linea 1. c.n.r. 310 pp. santo a. & tuccimei p. (1997) ricostruzione di eventi deformativi di versante tardo-quaternari ed olocenici attraverso studi geomorfologici e datazioni radiometriche th/u: l’esempio dell’area di vico equense (campania). “il quaternario” 1100 (2), 1997, 447-484. sigurdsson h., cashdollar s. & sparks s. r. j. (1982) the eruption of vesuvius in a.d. 79: recostruction from historical and volcanological evidence. am. journ. archeology, 86. travaglini g., valdinucci a. (1964) sulla frana di nerano e termini nel febbraio 1963. università di napoli istituto di idraulica agraria. tropeano d., casagrande f., luino f., cescon c. (1996) processi di mud-debris flow in val cenischia (alpi graie): osservazioni nel bacino del t. marderello. geam, quaderni di studi e documentazione, anno xxxiii n. 2233. 5-31. vallario a. (1992) le frane nelle piroclastiti della campania, in a. vallario frane e territorio. le frane nella morfogenesi dei versanti e nell’uso del territorio, liguori ed. napoli. vallario a. (2001) i l dissesto idrogeologico in campania. cuen ed. napoli. 37pericolosità connessa a processi alluvionali ... ms. ricevuto il 13 giugno 2001 testo definitivo ricevuto il 15 febbraio 2002 ms. received: june 13, 2001 final text received: february 15, 2002 impaginatocarobene ffoorrmmee tteerrrraazzzzaattee rreelliittttee ddii ggeenneessii mmaarriinnaa lluunnggoo llaa ccoossttaa lliigguurree ttrraa ggeennoovvaa ee ssaavvoonnaa ((lliigguurriiaa oocccciiddeennttaallee)) ll.. ccaarroobbeennee && mm.. ffiirrppoo università degli studi di genova dipartimento per lo studio del territorio e delle sue risorse (dip.te.ris.) corso europa, 26 16132 genova riassunto vengono esaminati in maniera organica i terrazzi marini del tratto di costa genova – savona; essi si presentano in generale come relitti, rimodellati da una forte e prolungata erosione. lo studio ha permesso infatti di collegare la genesi dei terrazzi all’evoluzione plio-quaternaria di questo settore costiero, che presenta sedimenti del pliocene inferiore oggi affioranti fino alla quota di 100 200 m. le considerazioni dedotte dalla presente ricerca riguardano aspetti morfologici, stratigrafici e tettonici, così sintetizzabili: 1) sono riscontrabili varie tipologie di forme terrazzate relitte; 2) le superfici più basse sono correlabili in 3 ordini di terrazzi, probabilmente quaternari, che occupano una fascia costiera fino alla quota di 145 m; 3) i relitti più alti sono mal correlabili tra loro, si presentano molto erosi, sono probabilmente pliocenici e occupano una fascia costiera più interna fino a circa 400 m di quota; 4) le superfici più basse di 145 m conservano quasi sempre depositi marini costieri pedogenizzati; 5) il sollevamento costiero ha prodotto un basculamento, ben riconoscibile nel terrazzo che si alza progressivamente in quota da 60 m (savona) a 145 m (genova); 6) la fascia costiera terrazzata può essere suddivisa in settori trasversali diversi tra loro per caratteri morfologici e geologici; 7) l’età dei terrazzi è ipotizzabile in maniera indiretta in base a considerazioni sullo stato di erosione che essi presentano e in base ai rapporti con i depositi del pliocene inferiore; 8) il sollevamento si è manifestato in due fasi principali caratterizzate da differente velocità; 9) la linea di costa ad andamento rettilineo circa ene–oso (tratto savona voltri) denuncia il controllo tettonico sulla separazione tra l’area di terraferma sollevatasi nel plio-quaternario e l’area di piattaforma in subsidenza. abstract relict terraced landforms of marine origin along the coast between genoa and savona (liguria, italy) a geological survey of the coast between genoa and savona was carried out with the aim of fully describing, correlating and presenting all the ancient terraced landforms and deposits associated with ancient sea levels that rise to more than 300 m above actual mean sea level. the area falls within the eastern sector of the ligurian alps, where a number of metamorphic units crop out: the savonese and arenzano crystalline massifs (paleozoic continental crust) and the voltri group (oceanic crust and serpentinised peridotites) (fig. 1). the coastal terraces examined had previously been studied by issel (1883), rovereto (1939), limoncelli and marini (1969), cortemiglia (1983), none of whom was, unfortunately, able to give a complete, systematic description of the morphology or deposits or adequate correlations between the terraces. the survey obtained the following information: 1) the relics associated with ancient marine terraces are of various types: terraced surfaces that stretch along the main ridges (that fall directly to the sea), the outer edge and inner margin of which are identifiable; sub-horizontal parts of ridge delimited by outer edge and inner margins; successions of culminations of similar altitude aligned along the main ridges; isolated remains of summital terraced surfaces lacking inner margins; terraced surfaces running along the coast and corresponding to a marine platform covered by thick marine and continental deposits. the “inner margin” is some metres higher than the ancient coastline (terrace 25 m above mean sea level in tab. 1) (fig. 11). 2) three orders of terraces were identified. the first order consists of clearly correlatable terraced surfaces whose inner margins rise to an altitude of from 60 m at savona to 145 m a.s.l. at genoa; there is almost always a weathered marine deposit on these surfaces. the second order, only clearly identifiable in sector 9, consists of small terraced remains with inner margins 60 m a.s.l., on which weathered pebbly deposits are preserved. terraced surfaces with inner margins 35 m a.s.l., identified in the less uplifted sector 1, could belong to this order. the third order consists of terraced surfaces with inner margins at 25 m a.s.l., referring to two marine platforms (fig.11), the more high of the two with an inner margin at 17 m a.s.l. and the lower one with an inner margin at 7 m a.s.l. both platforms are overlaid by marine deposits and do not seem to show regional tilting. 3) along the stretch of coast surveyed it was also possible to identify terraced relics higher than the order of terraces between 60 m and 145 m described above. these relics have an average width of about 450 m and inclinations of about 2°; they are distributed between 100 and 400 m a.s.l. and are difficult to correlate as they are very eroded (plate i) and without deposits. a better understanding of these relics will require further studies. 4) both marine and continental deposits were identified on the terraced surfaces included in the four orders cited above. the marine deposits have a maximum thickness of 4-5 m and mainly consist of gravel with rounded pebbles, often flattened and imbricated towards the sea; those at natta (fig. 5) and voltri (plate i) are particularly well preserved. the deposits are always strongly weathered (red, yellowish red, reddish brown; 2.5 yr and 5 yr). 5) the uplift of the ancient terraced surface caused the tilting that is attested by the order of terraces that varies progressively in height from 60 m a.s.l. at savona to 145 m at genoa (orange coloured terrace in plate i). it is more difficult to establish the degree of tilting of the terraces above this order. the lower orders (+7 m and +17 m) seem to have remained sub-horizontal. 6) the coastal area surveyed can be divided into different sectors (fig. 2) on the basis of its general morphology and the lithology of the substratum. furthermore, the variation in the height of the terraces suggests that some sectors have been separated by neotectonic transverse faults (e.g. sector 4, tab. i). 7) the age of the terraces has been approximately calculated on the basis of the reliable data available: the early pliocene is the most recent part of the substratum which is preserved in scattered relics along the coast at less than 100 m a.s.l; the terraces lying above the order at 60÷145 m a.s.l. are very eroded and without deposits; the terraced order lying at 60÷145 m a.s.l. formed after the early pliocene emersion; il quaternario italian journal of quaternary sciences 1155(1), 2002, 53-68 11.. iinnttrroodduuzziioonnee con la presente ricerca, condotta sia sul terreno sia mediante l'analisi delle carte topografiche alla scala 1:5.000 della regione liguria, si è cercato di documentare, rappresentare e correlare per la prima volta tutte le forme plioquaternarie derivanti da alti livelli di stazionamento del mare nel settore costiero compreso tra genova e savona. con opportuni simboli è stato evidenziato anche l'aspetto che tali forme presentano: un primo gruppo è infatti costituito dai relitti dei terrazzi più alti per i quali non ci sono prove dirette e sicure della loro origine marina, che hanno subìto una fortissima erosione e che oggi corrispondono a crinali stretti, irregolari, leggermente inclinati verso mare, privi di coperture detritiche. un secondo gruppo comprende relitti di terrazzi a quote intermedie, meglio conservati, in cui l'erosione ha frammentato l'originaria disposizione parallela alla costa e ha distrutto in parte, a volte totalmente, l'eventuale deposito marino. il terzo gruppo infine comprende superfici marine a quote basse, disposte fronte mare, dove il sedimento marino è stato poco eroso ed anzi coperto da spessi depositi colluviali o da conoidi detritiche. tale rappresentazione concorda bene anche con l'età relativa da attribuire a tali forme relitte, in quanto le più alte e le più erose sono le più antiche; le più basse, protette dai depositi continentali di piede di versante, sono le più recenti. poco o nulla è emerso tuttavia sull’età dei terrazzi, per la mancanza di reperti databili. le interpretazioni cronologiche proposte nelle conclusioni sono state pertanto ricavate indirettamente utilizzando i dati certi in possesso e alcune ipotesi. lo studio dei terrazzi marini risale in liguria alla fine dell' 800; sono infatti issel (1883 e 1911) e successivamente rovereto (1939) i primi due autori a descrivere forme e depositi legati all'azione del mare lungo tutta la costa ligure, allora in gran parte non ancora urbanizzata. dal 1939, anno in cui venne pubblicato il volume di rovereto "liguria geologica", agli anni 1980 sono rari i lavori su questo argomento; ricordiamo in particolare limoncelli & marini (1969). all'inizio degli anni '80 il progetto finalizzato "neotettonica" dà nuovo impulso alle ricerche; sono infatt i di quel periodo i lavori di cortemiglia (1983) che propone un quadro sinottico di tutte le antiche linee di riva della liguria, e di fanucci & tedeschi (1983) sui terrazzi marini del foglio 82 genova (scala 1:100.000). successivamente fanucci (1987) presenta una completa rassegna delle conoscenze sulle linee di riva della fascia ligure costiera emersa legando queste ultime alle osservazioni, che in quegli anni si stavano raccogliendo, sulla piattaforma continentale. bisogna poi passare agli inizi degli anni ‘90, quando alcuni cantieri aperti sul territorio ligure permisero accurati rilevamenti geologici, morfologici e stratigrafici che portarono alla stesura della nota di carobene & firpo (1994). 22.. iinnqquuaaddrraammeennttoo ggeeoommoorrffoollooggiiccoo ddeell ttrraattttoo ddii ccoossttaa ssttuuddiiaattoo 22..11.. ccaarraatttteerrii ggeeoollooggiiccii l’area di studio assume particolare interesse in quanto comprende il tratto orientale della catena alpina ligure, separata ad est da quella appenninica dalla zona sestri-voltaggio, comprendente: l’unità triassico-liassica di monte gazzo-isoverde, l’unità cravasco-voltaggio e l’unità del monte figogna; quest’ultima zona compare solo parzialmente in corrispondenza del settore 9 (fig.2). il massiccio cristallino savonese, il massiccio cristallino di arenzano e il gruppo di voltri rappresentano le tre unità alpine presenti nell'area; queste unità tettoniche da un punto di vista paleogeografico appartengono rispettivamente: le prime due al basamento continentale europeo pre-carbonifero superiore del dominio brianzonese ligure, l'ultima a quello oceanico del dominio piemontese ligure (s.g.i., 1991). i l basamento polimetamorfico del dominio brianzonese rappresenta la crosta continentale paleozoica delle alpi liguri ed è costituito da rocce di crosta continentale che hanno subìto processi metamorfici di grado elevato. le rocce che affiorano nell'area di studio sono: anfiboliti e gneiss, paragneiss, micascisti ed ortogneiss (fig.1). le metaofioliti del dominio piemontese ligure rappresentano una crosta oceanica sviluppatasi nel giurassico attraverso processi che hanno portano ad una progressiva risalita del mantello astenosferico con conseguenti processi di fusione parziale; i fusi così 54 carobene-firpo the lower terraces, including that lying at 60÷145 m a.s.l., have better preserved surfaces on which it is possible to observe both marine and continental deposits. the absence of middle and late pliocene sediments and pleistocene shelf deposits along the stretch of coast surveyed would suggest that the uplifting of the early pliocene bathyal clays was very rapid and largely finished during the pliocene. the very eroded highest terraced remains, visible today as narrow sub-horizontal ridges without deposits, can be dated to this period. instead, the uplift would have proceeded very slowly in the quaternary, lifting the early pliocene layers to their present-day height of about 100 m a.s.l.; the terrace that rises to an altitude of from 60 m at savona to 145 m at genoa also probably belongs to this period as it is relatively well preserved. the two lowest coastlines, at +7 m (attributed to ois 5e) and +17 m (attributed to ois 9 or 11) document a very slow rate of uplift, less than or equal to 0.05mm/yr. the terraces considered to be quaternary occupy a coastal stretch approximately 750 m wide and up to 145 m a.s.l. the oldest terraced relics, probably pliocene in age, occupy a more inland stretch, up to 400 m a.s.l. and are about 2 km wide. landward of these, the slopes rise rapidly towards the ligure-padano watershed line. parole chiave: morfologia costiera, pliocene, quaternario, terrazzi marini, tettonica quaternaria, liguria key words: coastal morphology, pliocene, quaternary, marine terraces, quaternary tectonics, liguria 55forme terrazzate relitte ... f ig . 1 s ch em a ge ol og ic o se m pl ifi ca to d el l’a re a st ud ia ta . s im pl ifi ed g eo lo gi ca l s ch em e of th e ar ea s ur ve ye d. generati hanno originato rocce gabbriche e basaltiche che assieme alle rocce del mantello sono state coinvolte in fenomeni tettonici e successivamente ricoperte dai sedimenti marini pelagici silicei e carbonatici. le rocce mantelliche sono state dapprima serpentinizzate e successivamente, assieme ai gabbri ed ai basalti ed alle loro coperture sedimentarie oceaniche, hanno subìto una evoluzione metamorfica conseguente agli eventi orogenici alpini. i litotipi affioranti appartenenti a tale dominio sono: eclogiti, serpentiniti e serpentinoscisti, metagabbri e metabasiti, calcescisti e filladi. le unità citate sono state poi variamente coperte e sigillate trasgressivamente dai depositi sedimentari oligocenici (conglomerati e arenarie) del bacino terziario piemontese (b.t.p.) e dai sedimenti plioquaternari. il pliocene è rappresentato da argille giallastre e marne argillose grigie con intercalazioni sabbiose, ricche di macro e microfossili di mare profondo, conservate in maniera discontinua fino alle quote di 100-200 m in tutto il tratto di costa indagato, a testimonianza del sollevamento avvenuto a partire dalla fine del pliocene inferiore. infine il quaternario è rappresentato da alluvioni antiche e recenti terrazzate, coltri detritiche eluvio-colluviali, depositi ciottolosi e sabbiosi dei terrazzi marini. 22..22.. ccaarraatttteerrii ggeeoommoorrffoollooggiiccii per meglio comprendere il tratto di costa studiato occorre metterlo in relazione sia con la struttura geologica sia con un elemento di grande importanza morfologica rappresentato dallo spartiacque ligure-padano (l.p.). per agevolare la descrizione, la fascia costiera è stata suddivisa in 9 settori che si diversificano per caratteri geologici e morfologici generali. in essi i terrazzi vi compaiono con quota, stato di conservazione e numero di ordini differente. la suddivisione in settori è riportata in fig 2, mentre non compare in tav.i. in corrispondenza dei settori occidentali 1, 2 e 3, tra savona e varazze, lo spartiacque l.p. forma un grande arco concavo verso mare, allontanandosi dalla costa fino a 10-12 km e abbassandosi in quota fino ai 516 m del p.so del giovo. i terrazzi costieri risultano discretamente conservati, ma frammentati lungo decine 56 carobene-firpo fig. 2 l’area indagata è stata suddivisa in nove settori differenti per gli aspetti morfologici generali, per i caratteri geologici del substrato e per le quote dei terrazzi. the area surveyed was divided into nine different sectors on the basis of its general morphological characteristics, the geological characteristics of the substratum and the height of the terraces above sea level. 57forme terrazzate relitte ... di crinali a causa della presenza di molti corsi d'acqua, tra cui i più importanti sono i torrenti letimbro, sansobbia e teiro. nell'area affiorano in prevalenza rocce metamorfiche del massiccio cristallino savonese e conglomerati oligocenici (b.t.p.). tra varazze e arenzano (settori 4, 5, 6), dove l'ordine intermedio dei terrazzi (tra 95 e 120 m di quota) si presenta meglio conservato e più continuo, lo spartiacque l.p. si avvicina alla costa fino a 4-5 km, formando un arco convesso verso mare tra il m. beigua (1287 m) e il m. reisa (1183 m). nell'area il substrato è rappresentato da serpentiniti ed eclogiti del gruppo di voltri; al suo interno i corsi d'acqua sono brevi e a forte pendenza (rio arenon, t.arrestra e rio lerone). tra arenzano e palmaro (settori 7 e 8), dove l'ordine intermedio dei terrazzi (tra 130 e 140 m circa di quota) risulta invece poco presente e mal conservato, lo spartiacque l.p. nuovamente si allontana fino a 6-7 km dalla costa, formando un arco tra m. reisa e il m. penello (995 m) e abbassandosi in quota fino ai 532 m del passo del turchino. nell'area affiorano rocce erodibili corrispondenti ai calcescisti del turchino; i corsi d'acqua importanti sono il t. cerusa e il t. leiro. la linea di costa attuale, inoltre, che nel tratto savona-voltri ha un andamento rettilineo circa eneoso (58°), assume la direzione ono-ese (105°) da voltri a recco. nel tratto di costa tra palmaro e genova lo spartiacque l.p. si distanzia bruscamente dalla linea di costa abbassandosi dai 995 m del m. penello ai 475 m del passo dei giovi. in quest'area affiorano le unità liguri sedimentarie giurassico-cretaciche, che non hanno permesso una buona conservazione delle superfici terrazzate; al suo interno è incisa, con andamento circa nne-sso, la grande valle del t. polcevera. pertanto esistono correlazioni tra lo stato di conservazione dei terrazzi e gli aspetti morfologici del versante ligure con la litologia del substrato; la linea di costa invece, pressoché rettilinea tra savona e voltri, non sembra risentire né dei cambiamenti litologici, né dell'andamento irregolare dello spartiacque l.p. questa particolarità testimonia il suo legame con l’evoluzione recente del margine continentale. 33.. mmeettooddoollooggiiaa ddii rraapppprreesseennttaazziioonnee i relitti di superfici terrazzate di genesi marina riconosciuti lungo il tratto di costa esaminato si presentano, nella maggior parte dei casi, come forme molto rimodellate da processi erosivi derivati dall' emersione e dal sollevamento della fascia costiera: la differente tipologia che tali relitti presentano è abbastanza ben riconoscibile dalle carte topografiche alla scala 1:5.000 della regione liguria, ma una verifica sul terreno è sempre stata necessaria. una buona conservazione delle originarie superfici terrazzate si osserva solamente al di sotto dei 30 m di quota, mentre a quote superiori l'erosione ha in gran parte smantellato le superfici; fa eccezione il grande terrazzo di arenzano, che presenta un lembo terrazzato con buona estensione areale tra i 90 e i 110 m di quota. i diversi aspetti osservabili sul terreno non sono adeguatamente descritti nelle proposte di segni convenzionali per la cartografia geomorfologica reperibili in letteratura (s.g.n.,1984), né d'altra parte è stato possibile dettagliare tutti gli aspetti morfologici e litologici (vedi ad es. carobene & ferrini, 1993) a causa della scala utilizzata per rappresentare il territorio esaminato in tav. i. e' stata pertanto creata una apposita simbologia (tav.i) che rappresentasse al meglio le situazioni di campagna, osservabili sia lungo i crinali che scendono direttamente verso mare, sia sui versanti fronte mare: 1) un primo tipo di relitto corrisponde a resti di superfici terrazzate rappresentabili con un simbolo areale; questo è delimitato a monte dal simbolo di margine interno e a valle dal simbolo di orlo esterno. 2) un secondo tipo di relitto corrisponde a tratti di crinale suborizzontali o inclinati di qualche grado verso mare. in questo caso la forma è rappresentata da una linea, delimitata a monte e a valle dai simboli di margine interno e orlo esterno. in alcuni casi esiste la combinazione tra il primo e il secondo tipo di relitti. 3) il terzo tipo di relitto è dato da tratti di crinale molto erosi, topograficamente riconoscibili da una serie di culminazioni consecutive di quota simile; in alcuni casi è stato possibile inserire anche i simboli di margine interno ed orlo esterno. 4) un quarto tipo di relitto è dato da lembi isolati di superfici terrazzate prive di margine interno; questa posizione sommitale può essere genetica o derivare dall’erosione del margine interno. 5) lungo determinati tratti di costa (ad es. tra voltri e palmaro ) sono presenti infine lembi terrazzati tra 5 e 25 m s.l.m., limitati lateralmente dall'incisione valliva dei corsi d'acqua; consistono in piattaforme di erosione marina ricoperte da spessi depositi marini e continentali (carobene & firpo, 1994). per tutte le superfici terrazzate e, in particolare, per questo tipo di forme terrazzate disposte lungo versanti fronte mare, bisogna osservare che il "margine interno" corrisponde sempre ad un "margine morfologico" riconoscibile cioè in base a osservazioni puramente topografiche. a causa della spessa copertura continentale di piede di versante, il margine interno della piattaforma marina può risultare più basso in quota di svariati metri, fino a 5-8 metri (carobene & firpo 1994) (v. paragr.4.3.). sulla carta sono stati infine riportati alcuni "punti quotati significativi", in quanto a volte corrispondono a culminazioni del rilievo aventi quote simili correlabili; esse potrebbero testimoniare relitti di antiche superfici terrazzate fortemente erose che, pertanto, si sviluppavano ad una quota certamente più alta. i lembi relitti di antiche superfici terrazzate vengono pertanto descritti morfologicamente nella tav. i allegata; il substrato nel quale è intagliata la superficie di erosione marina è riportato nello schema geologico (fig.1). eventuali campioni raccolti sono descritti nel testo. il corpo sedimentario rinvenuto sui lembi terrazzati viene analizzato sia mediante descrizione nel testo, sia mediante colonne stratigrafiche riportate in tav. i. vengono fornite sintetiche informazioni riguardanti aspetti strutturali e tessiturali, con particolare riguardo alla granulometria dei depositi, alla natura dei clasti, agli spessori e alla pedogenesi. molti depositi, direttamente poggianti sulla superficie del substrato, sono risultati di origine marina per le strutture sedimentarie osservate (quali l’embriciatura dei ciottoli verso mare), per la forma appiattita e per l'arro58 tondamento dei clasti e per la buona classazione del deposito. quando non sono presenti tutti questi elementi e in particolare i fossili, l’attendibilità della genesi marina è ovviamente minore. tuttavia in molti casi possono essere utili anche considerazioni geografiche: ad esempio il deposito ciottoloso a clasti arrotondati di un terrazzo sviluppato lungo costa, lontano da foci fluviali, può essere stato alimentato solamente dalle correnti marine costiere. le discontinuità tra il corpo sedimentario e il sottostante substrato antico, o tra il deposito marino e l'eventuale deposito continentale sovrastante, sono state descritte qualora visibili. in particolare la superficie di discontinuità inferiore è sicuramente marina per l'ordine di superfici terrazzate che risulta colorato in arancione in tav.i e per gli ordini più bassi. per quanto riguarda le superfici di discontinuità che separano i corpi marini dai sovrastanti corpi continentali, esse hanno sempre carattere erosivo; i due depositi sono in generale marcati da differente grado di pedogenesi. a quote superiori (relitti terrazzati alti) vi è assenza di depositi e le originarie superfici risultano fortemente rimodellate ed erose; la disposizione dei relitti rispetto alle valli fluviali fa ritenere che essi siano di origine marina; per quanto riguarda i relitti disposti a quote superiori ai 300 m non si può escludere che essi derivino dalla distruzione di superfici di spianamento continentale, legate ad alti livelli di base. poco o nulla si è potuto infine osservare sulle deformazioni presenti nei depositi, per lo scarso spessore degli stessi, o perché non si sono potute effettuare osservazioni sulla superficie di appoggio basale. fa eccezione il deposito marino di natta, interessato da evidenti strutture deformative. 44.. ggllii oorrddiinnii ddeeii tteerrrraazzzzii la mappatura di tutti i relitti di forme terrazzate ha permesso, in assenza di datazioni, una prima correlazione delle superfici che, da savona a genovapegli, salgono progressivamente in quota da un minimo di 60 m ad un massimo di 145 m (le quote si intendono riferite al margine interno). questo ordine di terrazzi è evidenziato in color arancio in tav. i e verrà descritto al paragrafo 4.2 . sono state inoltre facilmente correlate le superfici terrazzate aventi il margine interno alla quota di 25 m; esse appaiono colorate in giallo in tav.i. in realtà queste superfici possono corrispondere a due ordini distinti di terrazzi, in quanto esse corrispondono a coperture continentali che mascherano due piattaforme marine a diversa altezza (paragr. 4.3). tutti gli altri relitti di forme terrazzate sono stati descritti assieme nel paragrafo 4.1. (relitti terrazzati alti). questi relitti alti, cartografati fino alla quota massima di 395 m, appartengono sicuramente a più ordini distinti, ma possono avere anche significato diverso: i più alti potrebbero testimoniare (come sopra detto) antiche superfici di spianamento continentale; altre forme potrebbero essere imputabili all'erosione selettiva; altre a fatti tettonici locali. la loro corretta interpretazione e correlazione non risulta quindi facile. 44..11.. ii rreelliittttii tteerrrraazzzzaattii aallttii gli alti relitti di forme terrazzate, riconducibili a stretti crinali a debole pendenza o ad una successione di culminazioni di quota simile (fig.3), sono stati mappati lungo i crinali principali che scendono verso mare. tali relitti appaiono distribuiti in maniera non omogenea lungo la fascia costiera esaminata; le loro quote non risultano pertanto facilmente correlabili. la loro ampiezza varia da meno di 200 m ad oltre 1 km (ampiezza media di 458 m); le inclinazioni dei tratti esaminati variano da 0,5° a 5° circa (valore medio di 2°). questi dati suggeriscono che si tratta di relitti di antiche superfici terrazzate, come si evince anche dal confronto con i valori di inclinazione dei versanti che scendono al mare, presi in esame a partire dalla quota dei relitti più alti: detti valori variano in gran parte da 7° a 20° (valore medio di 10,5°). nel settore tra varazze ed albissola marina (vedi tav.i) i relitti 257-249 m (bric crava), 270289 m, 256-276 m (bric terra bianca) e 261-254 m carobene-firpo fig. 3 profilo di un relitto di terrazzo alto, che consiste in un crinale molto eroso, poco inclinato, caratterizzato da culminazioni di quota simile e da assenza di depositi. crinale di bric terra bianca (settore 3): p.c.profilo topografico del crinale con le culminazioni di quota 256 m, 262 m e 276 m. in alto: ricostruzione geometrica della superficie terrazzata (s.t.), avente inclinazione di 2,8° e ampiezza di 1020 metri; il margine interno (m.i.) è a 300 m e l’orlo esterno (o.e.) a 250 m s.l.m. le scarpate (s) hanno una inclinazione media di 23° a monte e di 10° a valle. profile of a relic of a high terrace consisting of a very eroded slightly-inclined ridge characterised by culminations of the same altitude without deposits. bric terra bianca ridge (sector 3): p.c. – topographic profile of the ridge with culminations of 256 m, 262 m and 276 m above s.l.. above: geometric reconstruction of the terraced surface. terraced surface (s.t.) with angle of inclination of 2.8° and width of 1020 m, the inner margin (m.i.) is 300 m above mean sea level and the outer edge (o.e.) 250 m. the landward slopes (s) have an average inclination of 23° and the seaward ones 10°. 59 (torre bregalla), sembrano ben correlabili a testimoniare un’originaria superficie estesa tra 250 e 300 m circa (esempio in fig.3: crinale di bric terra bianca), con ampiezza massima di oltre 2 km ed una inclinazione media valutabile in soli 1,4°: ad essa sembrano correlabili le cime (poste più ad ovest) di monte pasasco (286 m) e di bric della seia (297 m). tra questo ordine più alto e l'ordine di terrazzi 60÷145 m (che in quest'area occidentale della costa ha un margine interno che varia da quota di 65 a 75 m), si riconoscono almeno altri due ordini, uno con margine interno tra 110 e 130 m, l'altro posto ad una quota non superiore a 220 m. nel settore 4, tra punta della mola e il torrente arrestra, il relitto 252-280 m (bric berlese) sembra ben correlabile all'ordine più alto precedentemente descritto; in quest'area tuttavia esistono relitti ben evidenti di una superficie più alta lungo il crinale che dal santuario la guardia (406 m) sale al bricco della forca (472 m) con una pendenza media di 1,5°(su una distanza di 2,5 km). nel settore 5, tra il torrente arrestra e il rio lerone, è molto evidente la grande superficie di prato zanino, un relitto alto che si presenta arealmente ben conservato (e che sarà oggetto di successive ricerche); la quota di questa superficie appare ben correlabile con alcuni “punti quotati significativi” presenti nel settore 5: crinale 194-177, quote 181, 179 e 193 m (bric del campo), quote 192 e 213 (monte ciapin). nei quattro settori orientali (tra il rio lerone e pegli) appaiono sporadici relitti alti tra le quote di 395 e 320 m, poco estesi e mal conservati a causa dell'affiorare di rocce erodibili (calcescisti del turchino). infine nei settori 8 e 9, tra voltri e pegli, sono presenti ben correlabili “i punti quotati significativi” da ovest verso est: 198, 192 (bric croce), 206 (bric del vento), 203 (bric scaggie), 201, 200 (bric castello). 44.. 22.. ii tteerrrraazzzzii iinntteerrmmeeddii a) l’ordine dei terrazzi da +60 a +145 m considerate le differenze morfologiche e altimetriche che questo ordine presenta, la descrizione viene effettuata per singoli settori (fig.2). l'appartenenza ad un unico ordine è garantita dal progressivo innalzamento in quota del margine interno che sulla distanza di 32,5 km produce un dislivello di 85 m, pari ad un angolo di 0,15° (pendenza dello 0,26%). gli studi di neotettonica (c.n.r.,1987; cortellesi et al.,1979) che avevano preso in considerazione soprattutto il substrato, non avevano invece evidenziato tale basculamento. settore 1: riva destra del torrente letimbro il terrazzo, smembrato in vari lembi dalle incisioni vallive, è intagliato in substrato metamorfico. il margine interno si situa tra 60 e 70 m; la superficie terrazzata più ampia, mappata tra le quote estreme di 25 e 65 m per comodità di rappresentazione, in realtà sul terreno mostra uno scalino compreso tra i 35 e 45 m che indicherebbe un terrazzo più basso esteso tra 25 e 35 m. depositi significativi sono osservabili nelle zone vicine al margine interno della superficie più alta e sono costituiti da sedimenti sabbioso-ciottolosi, con clasti prevalentemente quarzosi aventi diametro di 10-15 cm; il deposito si presenta sempre molto alterato. in particolare la stratigrafia più dettagliata è stata descritta nello scantinato delle scuole corradini di savona (fig.4), sulla superficie terrazzata più ampia tra le cinque rappresentate sulla forme terrazzate relitte ... fig. 4 successione stratigrafica relativa al terrazzo 60÷145 m affiorante sulla superficie terrazzata in destra del torrente letimbro (settore 1), con margine interno a 65 m di quota (tav.i). (a)strato ciottoloso basale costituito da clasti quarzosi e metamorfici ben arrotondati e abbastanza sfericizzati, con diametro prevalente di 1 cm. la matrice è scarsa, sabbiosa. i radi clasti maggiori raggiungono i 10-15 cm; sono ben arrotondati e spesso appiattiti, disposti orizzontalmente o embriciati verso e o ese. il deposito, che può essere riferito ad una spiaggia, si presenta pedogenizzato(5yr-4/6). (b)strato sabbioso poggiante su una superficie di erosione. e’ costituito da sabbie grosse, mal classate, con lenti irregolari di clasti arrotondati aventi diametro inferiore a 1 cm e con radi clasti maggiori. il deposito, che si presenta gradato, sabbioso-pelitico nella parte alta, può essere riferito all’ambiente fluviale. (c)livello argilloso-siltoso grigio, privo di ciottoli, derivante da decantazione di materiale fine in ambiente fluviale. (d)deposito colluviale pelitico contenente clasti spigolosi con diametri prevalenti di pochi centimetri, alcuni fino a10 cm; radi i clasti arrotondati. il deposito si presenta pedogenizzato (7.5yr-6/6). stratigraphic succession associated with the terrace between 60 and 145 m which crops out of the terraced surfaces on the right of the letimbro torrent (sector 1), with inner margin 65 m above mean sea level (plate i). (a)basal pebbly layer consisting of well-rounded and fairly spherical quartzitic and metamorphic clasts with a predominant diameter of 1 cm. the matrix is poor and sandy. the largest scattered clasts, which are well-rounded and often disposed horizontally or imbricated towards the e or ese, measure up to 10-15 cm. the deposit, which can be associated with a beach, shows pedogenic alteration (5yr-4/6). (b)sandy layer lying on an erosion surface. it consists of badly-classed large grains, with irregular lenses of rounded clasts with a diameter of less than 1 cm and scarce bigger clast. the deposit, which is graded, sandy-pelitic towards the top, can be associated with a river environment. (c)grey clayey-silty level, without pebbles, coming from the settling of fine material in a river environment. (d)pelitic colluvial deposit containing angular clasts with a prevalent diameter of a few centimetres; some up to 10 cm; some rounded clasts. the deposit shows pedogenic alteration (7.5yr-6/6). fig. 5 in prossimità del margine interno del relitto terrazzato di natta (settore 3), uno scavo ha messo in luce la seguente stratigrafia: s = substrato oligocenico costituito da bancate di arenarie e conglomerati alterati e fagliati. il sovrastante deposito marino è suddiviso in: i = unità basale ghiaiosa, comprendente a) sabbia medio-grossa ghiaiosa, rubefatta, con granuli fino a 5 mm, che presenta localmente ciottoli arrotondati di 5–20 cm, a volte appiattiti ed embriciati a se; b) ghiaia fine, ben selezionata, senza matrice, con ciottoletti arrotondati di 3–8 mm; c) ghiaia sabbiosa, con ciottoletti arrotondati fino a 1,5 cm. le caratteristiche di questa unità sembrano indicare un deposito di battigia. ii = unità sabbiosa costituita da: a) alternanza di sabbie medie e molto grosse, con radi ciottoletti; b) sabbia grossa con livelli di ciottoli arrotondati aventi diametro massimo di 1–2 cm; l’unità indica un aumento della batimetria. iii = unità ghiaiosa, che in basso mostra: a) sabbie molto grosse e granuli fino a 3 mm, selezionate e prive di matrice; in alto passa a b) ghiaietto con ciottoletti arrotondati compresi tra 0,5 e 3 cm, senza matrice sabbiosa. le caratteristiche tessiturali indicano alta energia dell’ambiente. iv = unità sabbiosa, costituita da sabbie medie o grosse, massive, con rarissimi ciottoli appiattiti; è visibile per oltre un metro di spessore. essa indica probabilmente la spiaggia emersa. il deposito marino è ricoperto da un corpo detritico continentale sabbioso – ciottoloso d, molto arrossato (colori munsell 2.5 yr 4/6 e 10r 3/6), costituito da ciottoli in prevalenza spigolosi immersi in abbondante matrice sabbioso – limosa. questo deposito colluviale è a sua volta ricoperto da debris flow più recenti, pedogenizzati (colore munsell 5yr 4/6). close to the inner margin of the terraced relic of natta (sector 3), well has revealed the following stratification: s = oligocene substratum consisting of layers of sandstone and weathered conglomerates showing signs of faults. a marine deposit subdivided into: i = a gravely basal unit, consisting of: a) medium-large grained reddened gravely sand, with grains as fine as 5 mm, with scattered rounded pebbles of 5-20 cm, sometimes flattened and imbricated to the se; b) fine gravel, well-sorted, without matrix, with rounded pebbles of 3-8 mm; c) sandy gravel, with small rounded pebbles as small as 1.5 cm. the characteristics of this unit seem to indicate a shore deposit. ii = a sandy unit consisting of: a) an alternation of medium and very coarse sands with small scattered pebbles; b) coarse sand with layers of rounded pebbles with a maximum diameter of 1-2 cm. this unit indicates an increase in the bathymetry. iii = a gravely unit which passes from a) very coarse sands and fine sands with grain as fine as 3 mm, sorted and without matrix in its lower level, to b) fine gravel with rounded pebbles between 0.5 and 3 cm, without sandy matrix, in its upper level. the textural characteristics indicate a high-energy environment. iv = a sandy unit which is visible for over a metre in thickness and consists of massive medium and coarse sands with very occasional flattened pebbles. this probably indicates an emerged beach. the marine deposit is covered by a layer of sandy-pebbly continental detritus, very reddened (munsell colours 2.5yr – 4/6 and 10r – 3/6), mainly consisting of angular pebbles in an abundant muddy-sandy matrix. this colluvial deposit is in turn covered by a more recent pedogenic flow debris (munsell colour 5yr – 4/6). carta. settore 2: dal torrente letimbro al torrente sansobbia il terrazzo, intagliato nel substrato metamorfico, si presenta suddiviso in sette lembi terrazzati la cui ampiezza è compresa tra 400 e 600 m. il margine interno varia da 65 a 70 m s.l.m., mentre l'orlo esterno oscilla tra 45 e 55 m s.l.m. l'area è intensamente urbanizzata e non ha pertanto permesso di riconoscere bene gli eventuali depositi marini; la copertura, quando visibile, ha carattere continentale; nel deposito sono spesso presenti anche ciottoli arrotondati. settore 3: dal torrente sansobbia al torrente teiro-punta della mola il terrazzo risulta smembrato in numerosi lembi che si presentano piuttosto rimodellati ad esclusione di quello in località rio natta (tra celle e varazze); in questo settore sono compresi anche le tre superfici immediatamente ad est del torrente teiro. il terrazzo è intagliato nei conglomerati oligocenici (fig. 1) ed ha un margine interno che varia da so a ne da un minimo di 65 m ad un massimo di 80 m s.l.m. e l'orlo esterno che varia prevalentemente da 45 a 60 m s.l.m.su una distanza di 6 km. l’ampiezza del terrazzo (distanza tra l'orlo esterno ed il margine interno) raggiunge al massimo 750 m circa. i depositi sono scarsi e si ritrovano solo sui lembi meglio conservati: sono rappresentati da sabbie e ghiaie alterate. in particolare è descritto il deposito marino affiorante presso il margine interno in località rio natta. in questa località è stata riconosciuta la successione di fig. 5; la stratigrafia è composta di quattro 60 carobene-firpo intervalli sabbioso-ghiaiosi. l'embriciatura dei ciottoli verso se e verso so testimonia una trasgressione sul substrato oligocenico ed il relativo deposito di spiaggia. la sequenza descritta presenta localmente al suo top un paleosuolo (fig.6) dello spessore di circa un metro, coperto a sua volta da detrito più recente con una pedogenesi meno accentuata. al margine interno la sequenza è coperta da un colluvium molto pedogenizzato (2.5 yr fino a 10 r) che può essere coperto da detrito più recente (fig.a in tav.i). settore 4: da punta della mola al torrente arrestra il terrazzo è intagliato in rocce metamorfiche (fig. 1), presenta una buona continuità laterale ed un'ampiezza massima di 750 m. la quota del margine interno s’innalza in quota verso ne da 95 a 105 m, mentre l'orlo esterno oscilla tra 55 e 85 m su una distanza di 3,5 km (fig.7). il deposito marino, non sempre ben visibile in tutti i lembi sia per l'erosione subìta sia per le coperture continentali, si presenta solitamente costituito da grossi clasti ben arrotondati con diametri fino a 50-100 cm, a volte appiattiti; il taglio autostradale permette di vedere bene il deposito in corrispondenza del margine interno (fig.2 in tav i). in località "schiappapria", parte so del settore, la presenza di un pozzo d'acqua e i dati relativi alle fondazioni dell'albergo "la vignetta" hanno permesso di dedurre la presenza, sul substrato roccioso, di 4-6 metri di ghiaie marine coperte da alcuni metri di sedimenti detritici continentali (fig. 8). il settore in esame presenta inoltre i relitti di due lembi di una superficie terrazzata più alta compresa tra i 110 e i 140 m s.l.m., non riportata in tav.i per le sue dimensioni troppo limitate. settore 5: dal torrente arrestra al torrente lerone sono presenti cinque lembi di un terrazzo intagliato in serpentiniti e calcescisti del gruppo di voltri; la loro ampiezza varia da 250 a 600 m; il margine interno si mantiene tra i 115-120 m e l'orlo esterno tra gli 85 e 100 m s.l.m. il deposito marino è sempre presente ed è costituito in prevalenza da ciottoli ben arrotondati e 61forme terrazzate relitte ... fig. 6 deposito del lembo terrazzato di natta (settore 3), con margine interno a 75 m s.l.m. in basso affiora il substrato (s) costituito da conglomerato oligocenico molto alterato. il sovrastante deposito marino (dm), che ha uno spessore di 1,5 m, si presenta pedogenizzato con colori 2.5yr 3/6 e 4/8; la sua stratigrafia corrisponde a quella rappresentata in fig.5. in alto il paleosuolo (p) ha spessore di 1 metro ed è inclinato di circa 2° verso sud; si presenta argilloso, con screziature grigio-azzurre (n6/) e rosse (4/6) comprese nella carta munsell 2.5yr. il paleosuolo è ricoperto da debris–flow molto arrossato (10yr 4/6) e da successive coperture detritiche meno pedogenizzate. deposit on the terrace of natta (sector 3) with inner margin 75 m above sea level. at the base there is a substratum (s) of very weathered oligocene conglomerate. the overlying marine deposit (dm), which is 1.5 m thick, is reddish with munsell colours 2.5yr 3/6 and 4/8. its stratigraphy corresponds to that represented in fig. 5. the paleosoil (p) on top has a thickness of 1 m and is dipped about 2° to the south; it is clayey, with blue-grey (munsell 2.5yr-n6/) and red (munsell 2.5yr4/6) variegation. the paleosoil is covered with very reddened (10yr4/6) debris flow and weathered successive detritic layers. fig. 7 panoramica della superficie terrazzata di punta d’invrea (settore 4) vista da ne. view of terraced remains at punta d’invrea (sector 4) from the ne. spesso appiattiti con diametri prevalenti fino a 20 cm; lo spessore rilevabile è di almeno 2 m mentre quello della copertura continentale è generalmente debole ed in particolare è scarso o assente il deposito di piede di versante. localmente il deposito si presenta alterato. settore 6: dal rio lerone al rio lupara il settore è caratterizzato dalla grande superficie pp ss ddmm terrazzata di arenzano (fig.9) priva di margine interno, che si estende lungo costa per 1,5 km, con ampiezza massima di circa 800 m. la superficie è intagliata in rocce metamorfiche (fig.1) con un'elevazione massima di 111 m; l'orlo esterno, verso mare, varia tra i 70 e i 90 m. l'area si presenta intensamente antropizzata ed urbanizzata rendendo difficile la descrizione del deposito terrazzato; esso è costituito da ciottoli arrotondati di grande diametro e sabbie alterate. a nord, al piede dei rilievi, si estendono dieci lembi relitti con ampiezza variabile da un minimo di 100 m ad un massimo di 300 m del lembo meglio conservato in località terrarossa. il margine interno di questi relitti varia da 115 a 130 m mentre l'orlo esterno varia tra 85 e 110 m s.l.m, su una distanza di 3,5 km. i depositi di piede di versante, costituiti da brecce grossolane in 62 carobene-firpo fig. 8 profilo della superficie terrazzata nel settore 4, lembo so. l’analisi delle carte topografiche evidenzia il margine interno (m.i.) del terrazzo e i l suo orlo esterno (o.e.); essi delimitano la superficie terrazzata (s.t.), con inclinazione media di circa 8°. i dati di un sondaggio e la presenza di un pozzo per acqua (p) hanno permesso di riconoscere la presenza di un corpo sedimentario marino (c.s.m.) costituito da ghiaie, avente uno spessore massimo di circa 5 metri, che diminuisce progressivamente verso mare fino ad annullarsi. esso poggia su una piattaforma di erosione marina (p.e.m.), delimitata da un margine interno (m.i.p.) e da un orlo esterno della piattaforma (o.e.p.) ottenuti mediante ricostruzione geometrica; la piattaforma ha una inclinazione di circa 2,8°. la superficie terrazzata è delimitata da due scarpate (s.): quella a monte ha un’inclinazione di 22°, quella a valle di 26°. il terrazzo è intagliato in un substrato oligocenico (s.o.) costituito prevalentemente da conglomerati. il deposito marino è ricoperto da detrito continentale (d.c.) costituito da colluvium e debris flow. profile of the terraced surface in sector 4, sw remains. the analysis of the topographic chart reveals the inner margin (m.i.) of the terrace and its outer edge (o.e.); these delimit the terraced surface (s.t.), with a mean inclination of 8°. the survey data and the presence of a well (p) enabled us to recognise a marine sedimentary body (c.s.m.) consisting of a layer of gravel with a maximum thickness of about 5 m which progressively diminishes towards the sea until it disappears. this lies on a marine erosion platform (p.e.m.) delimited by an inner platform margin (m.i.p.) and an outer platform edge (o.e.p.) determined by geometric reconstruction. the platform has an angle of inclination of 2.8°. the terraced surface is delimited by two slopes (s): the landward one has an angle of inclination of 22°, the seaward one 26°. the surface is cut by an oligocene substratum (s.o.) consisting mainly of conglomerates. the marine deposit is covered by continental detritus (d.c.) consisting of colluvium and flow debris. fig. 9 veduta del terrazzo di arenzano (settore 6) da ovest. view of terraced surface at a r e n z a n o (sector 6) from the w. matrice limosa mascherano, con spessori di parecchi metri, il margine interno della superficie di abrasione che si situa, dove si è potuto vedere, a 115 m s.l.m. il deposito terrazzato è costituito da ciottoli arrotondati decimetrici coperti da depositi continentali a clasti spigolosi molto rubefatti (colore munsell 2.5 yr 3/6). il deposito è assente nei relitti più rimodellati costituiti da stretti crinali in roccia mentre è ancora ben conservato in località bicocca dove sul substrato metamorfico poggiano grossi ciottoli decimetrici tra cui evidenti quelli appiattiti. settore 7: dal rio lupara al torrente cerusa i calcescisti caratterizzano il substrato di questo settore (fig.1) e la loro forte erodibilità ha condizionato la conservazione dei terrazzi. lungo tutto il settore infatti sono difficilmente riconoscibili superfici terrazzate, ma sono presenti invece limitati crinali molto rimodellati o isolate culminazioni in gran parte non indicate nella tav.i, ad una quota compresa tra 115 e 135 m. le poche forme riconducibili a questo ordine di terrazzi conservano localmente ancora ciottoli arrotondati da centimetrici a decimetrici direttamente poggianti sul substrato metamorfico. settore 8: dal torrente cerusa al rio san pietro il substrato affiorante in questo settore è costituito da calcescisti, serpentinoscisti e metagabbri (fig.1); analogamente al settore precedente la natura litologica non ha favorito la conservazione dei terrazzi. inoltre l'intensa urbanizzazione, maggiore sulle superfici terrazzate, non ha permesso l'osservazione degli eventuali depositi. nel settore il lembo terrazzato maggiore è quello di località "castello" (villa galliera) alle spalle di voltri; esso è costituito da una piccola articolata superficie sommitale, priva quindi di margine interno, con quota massima a 112 m. il substrato è costituito da micascisti localmente coperti da biocalcareniti e sabbie limose stratificate, riferibili al pliocene in base al contenuto fossilifero (rovereto, 1939); substrato e depositi pliocenici sono stati spianati dal mare durante il modellamento del terrazzo. in tutto il settore non sono stati rinvenuti depositi riferibili al terrazzamento marino. altre testimonianze di quest'ordine sono culminazioni a quote simili, tra cui ricordiamo il bric bacciocco (124 m) che prosegue verso monte con un crinale suborizzontale avente margine interno alla quota di 135 m. settore 9: dal rio san pietro a multedo sono evidenti in questo settore le forme riferibili all'ordine in oggetto, il cui margine interno si situa tra 135 e 145 m e l'orlo esterno varia tra 115 e 120 m (fig.10). per le profonde modificazioni antropiche (vecchie postazioni militari) e per l'erodibilità del substrato (calcescisti e metagabbri) non è possibile riconoscere eventuali coperture terrazzate marine, eccetto quelle continentali a clasti spigolosi. l'analogia della forma e della quota permettono di attribuire anche questi relitti allo stesso ordine delle superfici terrazzate descritte precedentemente. b ) l' ordine di terrazzi a +65 m l'ordine a 65 m è osservabile tra il torrente leiro e multedo: si presenta con una serie di piccoli lembi terrazzati tra le quote di 60-65 m (margine interno) e 45 m (orlo esterno). la forte urbanizzazione e le coperture di piede di versante non hanno permesso osservazioni sui depositi marini eventualmente presenti, ad eccezione del cimitero di pegli e dei giardini di villa doria (fig. 10) dove sono visibili, al di sopra del substrato metamorfico (calcescisti), alcuni metri di deposito ciottoloso fino alla quota di 50-55 m. i ciottoli sono ben arrotondati con diametri di 5-15 cm; il deposito è fortemente pedogenizzato (2.5yr 4/8 3/6) e verso monte è coperto da detriti spigolosi di piede di versante. il salto morfologico con la paleofalesia a monte è sempre netto. questo ordine non è stato ritrovato (a questa quota) nel tratto a so di voltri. 44..33.. ii tteerrrraazzzzii bbaassssii l'ordine a +17 metri lungo l'arco di costa studiato compaiono saltuariamente terrazzi e depositi ben individuabili, con margine interno alla quota costante di 25 m. queste terrazzi possono corrispondere, come già detto, a due piattaforme marine con margini interni a 17 e 7 metri s.l.m. (fig. 11). quest'ordine è già stato descritto in località voltr i (settore 8) (carobene & firpo, 1994) dove depositi di spiaggia per uno spessore di 5 m ricoprono una piattaforma d'abrasione in roccia inclinata verso mare di 1,6°; ghiaie di battigia sono state riconosciute fino alla quota di 17 m (fig.4 in tav.i). una 63forme terrazzate relitte ... fig. 10 profilo topografico del crinale a n di pegli (settore 9), che mostra le superfici terrazzate con margine interno a 145 m e a 55 m s.l.m. la ricostruzione geometrica (in alto) del profilo topografico evidenzia le inclinazioni dei vari segmenti del profilo. s = scarpate; t = terrazzi. topographic profile of the ridge in the northern part of pegli (sector 9), that shows the terraced surfaces with inner margin at 145 m and 55 m above mean sea level. the geometrical reconstruction (top) of the topographic profile highlights the angle of inclination of the various segments of the profile. s = slope; t = terrace. situazione analoga è stata riscontrata nell’abitato di cogoleto (settore 5), dove un deposito di ghiaie embriciate di spiaggia è esteso fino alla quota di 15,6 m all'interno di un solco d'erosione marina in dolomie triassiche (fig. c in tav i). a capo torre, in destra del rio carrea (settore 3), una superficie di erosione marina tagliata nel conglomerato oligocenico conserva un relitto di sabbie medie, ben selezionate, senza ciottoli, per uno spessore di circa 1 metro. le sabbie, che si elevano fino alla quota di circa 18 m, risultano pedogenizzate (colore munsell 7.5 yr-4/6) e coperte da detrito colluviale (colore munsell 10 yr4/3). un'altra spianata simile a quella di voltri si rinviene a pegli in piazza bonavino, dove tuttavia non si è potuta osservare la stratigrafia dell’eventuale deposito. inoltre a celle in località rio natta (settore 3) (fig b in tav.i) è attribuibile a questa linea di riva un deposito di sabbia e ghiaia esteso tra i 12 e i 14 m. dalle osservazioni effettuate si può dedurre che la quota di quest'antica linea di riva rimane costante in tutto il tratto di costa studiato. l' ordine a +7 metri anche questo ordine di terrazzi è già stato descritto a voltri (settore 8) (carobene & firpo, 1994) dove i sondaggi hanno messo in evidenza una piattaforma di abrasione con margine interno a circa 7 m s.l.m. e inclinazione pari a 1,6°, coperta sia da sabbie e ciottoli arrotondati che da depositi detritici continentali a clasti spigolosi. conferme di questa linea di riva sono state riscontrate tra il torrente arrestra e il rio arenon (settore 4) al termine del lungomare europa, dove è visibile una superficie di erosione in substrato metamorfico con inclinazione verso mare di 1,5° ricoperta nella parte più a monte da un deposito marino ciottoloso con spessore massimo di 130 cm, sormontato a sua volta da un deposito continentale a clasti spigolosi di piede di versante di circa 9 m di spessore. inoltre nella parte ad est di cogoleto (settore 5) ricordiamo il lembo citato già da issel nel 1883 in località "lo scoglio". il nostro rilevamento (fig. d in tav. i) ha messo in evidenza un deposito sabbioso-ciottoloso di spiaggia poggiante su una superficie di abrasione a circa 4 m s.l.m. per uno spessore di quasi 1,5 m, che si estende verso monte fino alla quota massima osservata di 6 m. recenti scavi lungo la strada s.s.aurelia (ad e di cogoleto) hanno permesso di osservare che il deposito ciottoloso ricopre, con uno spessore di circa 1,5 m, una piattaforma di abrasione che risale dolcemente da 5 a 6 m s.l.m; il deposito marino è coperto da un potente deposito continentale alterato e arrossato esteso fino alla quota di 14-15 m. (vedi fig.11). lungo la strada costiera infine gli scavi hanno evidenziato il substrato metamorfico alla quota di 3,5 m coperto da ciottoli decimetrici arrotondati alterati; l'osservazione puntuale non ha permesso di ricavare la quota del margine interno. analogamente alla precedente, anche in questo caso la linea di riva sembra mantenere la stessa quota di circa 7 m lungo tutta l'area indagata. 55.. ccoonncclluussiioonnii le ricerche sui terrazzamenti di origine marina, condotte lungo il tratto di costa tra genova e savona fino alla quota di 400 m, hanno permesso di: 1 )definire varie tipologie di forme terrazzate relitte (tav.i); la varietà delle forme è in funzione del diverso grado di erodibilità del substrato, della estensione originaria del terrazzo e delle differenti età dei terrazzi. 2) riconoscere con certezza due ordini di superfici terrazzate, tra le tante riconosciute e mappate in tav.i. l’ordine più evidente è quello a 60÷145 m che appare basculato (vedi avanti al punto 5). a quota più bassa risulta ben delineato l’ordine con margine interno a 25 m (settori 5 e 8); ad esso possono corrispondere due differenti piattaforme di erosione marina (fig. 11) e quindi due antiche linee di riva poste a 7 e a 17 m s.l.m. (paragr.4.3.). localmente, in particolare tra cogoleto e varazze, la piattaforma marina a +7 m appare distinta da quella più alta ed è documentata da depositi marini. queste due linee di riva sembrano avere andamenti suborizzontali e si possono pertanto collegare agli alti eustatici più recenti, ovvero agli stages isotopici 9 oppure 11 per la linea a 17 m e allo stage 5e per la linea a 7 m, come già sostenuto da carobene & firpo (1994). 64 carobene-firpo fig. 11 schema della superficie terrazzata con margine interno a 25 m presente nei settori 5 e 8: st = superficie del terrazzo; pf.d. = paleofalesia degradata; c. = colluvium; d.c. = deposito continentale; m.i. = margine interno; o.e. = orlo esterno; p.m.i = piattaforma marina riferita agli stages 9 o 11; p.m.ii = piattaforma marina riferita allo stage 5; pf.s. = paleofalesia sepolta; m.i.p.= margine interno delle piattaforme marine; d.m.= deposito marino; l.m.= livello mare attuale. scheme of the terraced surfaces with an inner margin at 25 m above s.l. in sectors 5 and 8: st = terrace surface; pf.d = degraded paleocliff; c = colluvium; d.c. = continental deposit; m.i. = inner margin; o.e. = outer edge; p.m.i = marine platform associated with ois 9 or 11; p.m.ii = marine platform associated with ois 5e; pf.s. = buried paleocliff; m.i.p. = inner margin of marine platform; d.m. marine deposit; l.m. = actual sea level. meno rappresentato appare un ordine intermedio, corrispondente alle superfici con margine interno a 60-65 m presenti nel settore 9; queste sono state correlate con le superfici aventi margine interno a 35 m del settore 1. 3) evidenziare numerosi relitti di superfici terrazzate, più alte degli ordini precedenti, che risultano difficilmente correlabili tra loro in quanto fortemente rimodellate, discontinue e prive di depositi. 4) riconoscere e documentare litofacies, spessori e grado di pedogenesi delle coperture sedimentarie dei terrazzi, sia marine che continentali. in particolare l’origine marina degli ordini più bassi è documentata, oltre che dagli aspetti morfologici delle singole superfici terrazzate, anche dalle caratteristiche sedimentologiche dei depositi ritrovati nel corso della presente ricerca (cap.3); lo studio dei terrazzi fluviali (ricerca ancora in corso) sembra confermare inoltre l’origine marina anche per alcuni ordini terrazzati alti, come hanno evidenziato le ricerche sulla val varenna (brancucci & marini, 1990), dove sono stati riconosciuti terrazzi fluviali alti che si raccordano con spianate a 200-250 m s.l.m. 5) accertare un basculamento per l’ordine terrazzato a 60÷145 m, che risulta più sollevato a genova (tav.i). le possibili correlazioni tra le varie superfici sono state evidenziate dalla proiezione su un piano verticale circa ne-so per i settori da 1 a 7 e circa e-o per i settori 8 e 9, di tutte le quote dei margini interni delle forme terrazzate e di tutte le quote della più alta culminazione presente lungo i crinali privi di margine interno (fig. 12). in tal modo appare evidentissima la correlazione tra le superfici rappresentate in arancione in tav.i ed il basculamento subìto dall’antica linea di riva. per l’ordine immediatamente più basso il basculamento è stato supposto, correlando le quote di 35 m a so (settore 1) con quelle a 65 m a ne (settore 9). per i terrazzi più alti il basculamento è di difficile riconoscimento a causa dell’eccessiva frammentazione erosionale; una possibile correlazione è stata tracciata solamente per l’ordine di superfici comprendenti il grande terrazzo di prato zanino. 6) una suddivisione del tratto di costa in settori (fig.2), diversi tra loro per gli aspetti morfologici e litologici, ma anche per la diversità di quote che presentano gli ordini terrazzati (fig. 12). analizzando il progressivo aumento delle quote del terrazzo a 60÷145 m (da savona a genova-pegli), si può notare un’altra particolarità dei settori: la quota sale regolarmente da 65 a 80 m nel tratto corrispondente ai settori 1, 2 e 3; al passaggio tra i settori 3 e 4 la quota subisce uno scatto improvviso di circa 15 m, da 80 a 95 m; analogamente, al passaggio tra i settori 4 e 5, la quota sale da 105 a 120 m, con uno scatto di altri 15 m circa; nei settori 5 e 6 la quota rimane quasi costante, sui 120-125 metri; nei settori 7, 8 e 9, infine, le superfici terrazzate risultano comprese tra 135 e 150 metri. pertanto si può concludere che nel basculamento generale che porta le quote dei margini interni dei lembi relitti del terrazzo a salire dai 65 m (di savona) ai 145 m (di genova-pegli), vi sono incrementi di quota imputabili a faglie ad attività recente, trasversali alla costa; di particolare importanza le due linee tettoniche che limitano il settore 4, corrispondenti probabilmente ai tratti con andamento rettilineo dei torrenti teiro ed arrestra. i dati raccolti hanno permesso inoltre di: 7) riconoscere due fasi di sollevamento, manifestatesi nel tempo con differenti velocità. 8) stabilire limiti di età dei terrazzi che, comunque, rimangono da confermare con dati radiometrici, geochimici o paleontologici. per quanto riguarda i punti 7 e 8 sopra enunciati, relativi al sollevamento e all’età dei terrazzi, in assenza di datazioni di qualunque natura si è dovuto procedere mediante un ragionamento basato: a) sulla presenza di alcuni dati certi; b) sulla formulazione di alcune ipotesi; c)sulla conseguente deduzione di eventi e processi; d)sulla conferma più o meno esaustiva di quanto dedotto, mediante prove o evidenze di terreno. aa)) ii ddaattii il pliocene inferiore è il termine più recente del substrato nel tratto da genova a savona; non è documentata la presenza in affioramento di depositi marini del pliocene medio e superiore (late pliocene) (boni et al., 1981). il pliocene inferiore, in facies prevalentemente argilloso-marnosa, è conservato (tra savona e genova) in lembi sparsi a quote inferiori ai 100 metri (rovereto, 1934; boni & peloso, 1973; fanucci & tedeschi, 1983). fa eccezione il lembo di sciarborasca, innalzato per faglie a circa 200 m. i terrazzi alti (più alti dell’ordine a 60÷145 m) sono molto erosi e senza depositi , discontinui e difficilmente correlabili. il terrazzo attualmente costituito dalle superfici con margine interno variabile tra 60 e 145 m (da savona a genova) si forma dopo l’emersione del pliocene inferiore, in quanto le superfici terrazzate tagliano i depositi pliocenici ove affioranti ( savona, albissola, varazze, arenzano, voltri, genova-borzoli). i terrazzi intermedi e bassi (a partire dall’ordine a 60÷145 m) hanno superfici meglio conservate, sulle quali è quasi sempre possibile osservare depositi sia marini che continentali. bb)) llee iippootteessii per arrivare a quantificare i tassi di sollevamento e le età dei terrazzi, i dati sopra citati non sono sufficienti, ma permettono di formulare alcune ipotesi. occorre premettere che nel pliocene inferiore il margine continentale subisce veloce sommersione, sia per cause eustatiche che tettoniche; ciò determina la deposizione di argille la cui batimetria è variabile nei vari affioramenti, ma sempre riferibile al piano batiale, con profondità fino a 600 m ed oltre (negri et al., 1997); la sedimentazione comprende alternanze di conglomerati e argille (boni et al., 1985; gnaccolini, 1998) riferibili a deltaconoidi (marini, 2001), che documentano una progressiva inversione di tendenza dei movimenti verticali: l’emersione fu probabilmente molto rapida, tanto che non sembra documentabile in liguria il pliocene medio e superiore (late pliocene) lungo la costa emersa in esame (boni et al., 1981). premesso ciò, le ipotesi utilizzate sono le seguenti: il sollevamento dei depositi del pliocene inferiore si può far iniziare circa 4 milioni di anni fa (1° fase di sollevamento). il sollevamento porterà all’emersione del pliocene inferiore. l’emersione dei depositi del pliocene inferiore avviene durante il pliocene stesso. la batimetria del pliocene inferiore in facies argillosa è variabile, ma mediamente pari a 400 metri. 65forme terrazzate relitte ... cc)) llee ddeedduuzziioonnii la durata della 1° fase di sollevamento è uguale o minore di 2 milioni di anni. dopo l’emersione, il pliocene inferiore subisce un secondo sollevamento fino a 100 m s.l.m. attuale (fino a 200 m per faglia) (2° fase di sollevamento). la durata della 2° fase di sollevamento è uguale o maggiore di 2 milioni di anni. il tasso di sollevamento nella 2° fase di sollevamento è di conseguenza almeno 4 volte minore che nella 1°. il sollevamento e il basculamento dell’ordine di terrazzi oggi a 60÷145 m avviene durante la 2° fase di sollevamento. dd)) llee pprroovvee le due distinte fasi di sollevamento sono testimoniate da due differenti aspetti morfologici del versante costiero ligure: una fascia costiera superiore, compresa tra 100 e 400 m circa di quota (limite della zona indagata), larga mediamente 2 km (fino a 5 km nell’area albissola-varazze), prodotta da un sollevamento abbastanza veloce e molto antico. l’altro aspetto è costituito dalla fascia costiera inferiore, estesa al di sotto dei 100150 m; essa è larga mediamente 750 m e comprende l’ordine terrazzato a 60÷145 m. questa fascia testimonia la 2° fase del sollevamento, che si è manifestato len66 carobene-firpo fig. 12 proiezione su un piano verticale circa so-ne, da savona a genova, di tutte le quote dei margini interni delle superfici terrazzate e della quota più alta delle culminazioni presenti lungo crinali suborizzontali (dalla tav.i). è riportata in ascisse la suddivisione in 9 settori (fig.2) e la suddivisione altimetrica delle forme terrazzate relitte in una fascia inferiore (fi.) comprendente i terrazzi meglio conservati (probabilmente di età quaternaria) e in una fascia superiore (fs.) comprendente tutti i relitti terrazzati più erosi (probabilmente di età pliocenica). la fascia fi. comprende l’ordine meglio correlato 60÷145 m tra cui la grande superficie terrazzata di arenzano (indicata con la lettera a); il terrazzo si alza progressivamente in quota verso genova a causa di un basculamento in parte imputabile a faglie ad attività recente. questo andamento permette di correlare anche i terrazzi a 35 m dell’area di savona con quelli a 60-70 m presenti nel settore 9, ed inoltre di tentare la probabile correlazione della grande superficie di prato zanino (pz) con altri ampi crinali posti tra 110 m (settore 2) e 236 m (settore 7). nella fascia superiore (fs.) è stata infine circoscritta l’area s che comprende i relitti di terrazzi con quote da 261 e 290 m. vertical projection plane, approximately sw – ne, of the coast between savona and genoa, showing the elevations of the inner margins of all the terraced surfaces and the highest elevation of the culminations along the subhorizontal ridges (from table i). the subdivision into 9 sectors (fig. 2) and the altimetric subdivision of the relict terraced landforms into a lower band (fi), which includes the better preserved terraces (probably quaternary in age), and an upper band (fs), which includes all the more eroded terraced relics (probably pliocene in age), are presented in abscissa. the lower band includes the best correlated order, lying between 60 m at savona and 145 m above s.l. at genoa, which incorporates the large terraced surface of arenzano (indicated by the letter a); the terrace progressively rises towards genoa due to tilting, which can be partly attributed to faults and recent activity. this trend permitted us to correlate the large surface of prato zanino (indicated by the letters pz) with other wide ridges lying between 110 m (sector 2) and 236 m above s.l. (sector 7). the upper band includes area s, which incorporates terraced relics with an elevation between 261 and 290 m above s.l. tamente fino ai nostri giorni (fig. 12). il sollevamento (pliocenico e abbastanza veloce) che ha prodotto la fascia costiera superiore è documentato da numerosi relitti di superfici terrazzate, molto rimodellati, che si presentano come stretti crinali suborizzontali e come culminazioni a quote ricorrenti; è immaginabile che molte superfici terrazzate siano state completamente distrutte. il lento sollevamento che ha prodotto invece la fascia costiera inferiore trova conferma nella bassa quota del terrazzo a 60÷145 m, ampiamente inciso dai corsi d’acqua che lo hanno suddiviso originando decine di superfici terrazzate (circa 65), allungate lungo i crinali che scendono verso mare. poiché è il primo terrazzo che si è formato dopo l’emersione del pliocene inferiore, la sua età è antica,come viene documentato al punto seguente, e il suo sollevamento è essenzialmente quaternario. l’età antica del terrazzo a 60÷145 m è testimoniata dal sensibile rimodellamento delle superfici terrazzate, dalla parziale o totale erosione dei depositi terrazzati e dalla forte pedogenesi che essi presentano; considerazioni sul profilo pedologico permettono di affermare che nella maggior parte dei casi è presente solamente la parte basale dell’orizzonte b, con conservazione dei ciottoli originari, anche se molto alterati, caratterizzati da concentrazioni o spalmature nerastre di ossidi di fe e mn, accumulo di argille e forte rubefazione (colori munsell prevalenti 2,5 yr, fino a 10 r). anche il forte basculamento già descritto confermerebbe l’età antica di questo origine di terrazzi che, pertanto, può essere posta tra la fine del pliocene e il pleistocene inferiore. anche il lento sollevamento quaternario sembra documentabile; infatti tra l’ordine dei terrazzi a 60÷145 m e l’attuale linea di costa si contano solamente due ordini intermedi: quello a 60-65 metri del settore 9 (correlato con quello a 35 m del settore 1), e il terrazzo a 25 m dei settori 5 e 8. inoltre la morfologia costiera è caratterizzata da versanti ripidi o da falesie tra i principali corsi d’acqua. queste caratteristiche si ritrovano lungo altre coste della penisola italiana che durante il quaternario hanno subìto un lento sollevamento (vedasi carta neotettonica d’italia), quali ad esempio le coste di campania, basilicata, puglia e sardegna. in tale carta la fascia costiera della liguria di ponente è rappresentata in “standstill or moderate uplift in quaternary” (c.n.r., 1987). d’altra parte le coste a forte sollevamento quaternario si presentano tipicamente terrazzate (bosi et al., 1996), con 5-10 ordini di terrazzi ben evidenti; in lucania (amato et alii, 1998, calabria (barrier et alii, 1986; carobene & ferrini, 1993; ghisetti, 1981; miyauchi et alii, 1994) e sicilia (carbone et alii, 1983; di grande & raimondo, 1984), dove i tassi di sollevamento quaternario hanno valori di 0,5-1 mm/a, i terrazzi del pleistocene inferiore e medio si ritrovano ben conservati a parecchie centinaia di metri di altezza. le quote delle due linee di riva più basse (a +7 e a +17 m) attribuite rispettivamente allo stage 5 e agli stages 9 o11 (carobene & firpo, 1994), denunciano tassi di sollevamento inferiori o uguali a 0,05 mm/a; ciò sembra indicare che il tasso di sollevamento quaternario è andato diminuendo nel tempo. riassumendo le considerazioni sulle età e sui sollevamenti plioquaternari dei terrazzi evidenziati nel tratto di costa tra savona e genova, è possibile affermare che il versante costiero è caratterizzato da: 1) una fascia superiore estesa tra 100 e 400 m circa che comprende terrazzi sollevatisi durante il pliocene medio-superiore (1° fase di sollevamento, abbastanza veloce); 2) una fascia inferiore estesa dal livello del mare fino a 100-150 m circa comprendente terrazzi sollevatisi essenzialmente nel quaternario (2° fase di sollevamento, piuttosto lento). considerata la grande differenza di conservazione tra i terrazzi delle due fasce e la diversa distribuzione e numero delle superfici che le caratterizzano, sembra possibile avanzare l’ipotesi che le due fasce siano divise da un evidente intervallo cronologico. un’altra particolarità (alla quale si era già accennato al paragr. 2.1.) è il sostanziale andamento rettilineo della costa tra savona e voltri (retta tangente: savonapunta celle-punta dell’olmo-punta d’invrea-arenzanoscoglio nave). ciò può essere imputato ad un limite per faglia tra la zona costiera sollevatasi nel corso del plio-quaternario e la zona di piattaforma attuale subsidente. del resto faglie parallele alla costa sono già state segnalate in piattaforma (fanucci & nosengo, 1979; c.n.r., 1987). rriinnggrraazziiaammeennttii gli autori vogliono ringraziare il prof. tiziano mannoni per i dati forniti; il dott. m. marini per le utili discussioni ed il dott. c. queirolo per il contributo fornito nell’informatizzazione dell’iconografia. si ringraziano inoltre il prof. f. carraro per la revisione critica del manoscritto ed un anonimo revisore per gli utili suggerimenti. ricerche condotte con i fondi ateneo 1997-98 (020301001048) e 2000 (020301001088) riguardanti aspetti di geologia del quaternario in liguria; responsabile luigi carobene. llaavvoorrii cciittaattii amato a., belluomini g., cinque a., manolio m. & ravera f. (1998) terrazzi marini e sollevamenti tettonici quaternari lungo i l margine ionico dell’appennino lucano. il quaternario, 1100(2), 1997, 329-336. barrier p., di geronimo i. & lanzafame g. (1986) i rapporti tra tettonica e sedimentazione nell’evoluzione recente dell ’aspromonte occidentale (calabria). riv. it. paleont. strat., 9911(4), 537-556. boni p. & peloso g.f. (1973) i lembi pliocenici della liguria occidentale da terzorio al confine italofrancese. atti ist. geol. univ. pavia, 2233, 170-201. boni a., boni p., peloso g.f. & gervasoni s. (1985) nuove osservazioni e considerazioni sui lembi pliocenici del confine di stato a capo sant’ampelio. atti ist. geol. univ. pavia, 3300 (2), 246-309. bosi c., carobene l. & sposato a. (1996) il ruolo dell’eustatismo nella evoluzione geologica nell’area mediterranea. mem. soc. geol. it., 5511, 363-282. brancucci g. & marini m. (1990) stadi evolutivi della val varenna (riviera di ponente, liguria). boll. 67forme terrazzate relitte ... soc. geol. it., 110099, 351-365. c.n.r. (1987) neotectonic map of italy. quaderni della ricerca scientif ica, 44, n.114, 6 tavv. 1:500.000. carbone s., di geronimo i., grasso m., iozzia s. & lentini f. (1983) i terrazzi marini quaternari dell ’area iblea (sicil ia sud-orientale). c.n.r. prog.final.geodin., 550066 (1982), 1-35, napoli. carobene l. & ferrini g. (1993) morphological, sedimentological and tectonic features of diamantem.carpinoso marine terrace flight (tyrrhenian coast of northern calabria, italy). earth surf. proc. and landforms, 1188,, 225-239. carobene l. & firpo m. (1994) una paleospiaggia tra voltri e palmaro (genova): evidenze sedimentologiche e morfologiche. il quaternario, 77 (1), 123138. cortellesi d., fanucci f., giuffrè a., tedeschi a. & vignolo a. (1979) dati preliminari sulla neo-tettonica del foglio 82 genova . c.n.r.prog.final.geodin., 225511, 579-595, napoli. cortemiglia g.c. (1983) indizi geomorfologici significativi quale contributo alla stesura di una carta neotettonica della liguria. prog.final.geodim., 551133 (ii) (1982),397-404, napoli. di grande a. & raimondo w. (1984) linee di costa plio-pleistoceniche e schema litostratigrafico del quaternario siracusano. geologica rom., 2211 (1982), 279-309. fanucci f. & nosengo s. (1979) rapporti tra neotettonica e fenomeni morfogenetici del versante marittimo dell’appennino ligure e del margine continentale. boll. soc. geol. it., 9966 (1977), 41-51. fanucci f. & tedeschi d. (1983) linee di costa e terrazzi marini del foglio 82 (genova). c.n.r. prog.final.geodin., 551133 (ii) (1982), 387-396, napoli. fanucci f. (1976) il plioquaternario della piattaforma continentale ligure tra genova e savona. atti del ii congr. naz. a.i.o.l., santa margherita ligure; 8187. fanucci f. (1987) lignes de rivage quaternaires sur la côte et le plateau continentale l igure. z. geomorph. n. f., 3311 (4), 463-472. ghisetti f. (1981) caratterizzazione dei blocchi della calabria meridionale in base alle velocità di sollevamento nel plio-pleistocene: una proposta di zonazione neotettonica. c.n.r. prog. final. geodin., 335566 (ii) (1980), 775-809, napoli. gnaccolini m. (1998) le successioni conglomeratiche plioceniche della liguria occidentale: osservazioni preliminari sulla loro architettura e relativo significato. atti tic. sc. terra, 4400, 203-214. issel a. (1883) antiche linee litorali della liguria. boll. soc. geol. it., 11 (1882), 222-232. issel a. (1911) l’evoluzione delle rive marine in liguria. boll. soc. geogr. it., fasc. 9-12, 112 pp., roma. limoncelli. b. & marini.m. (1969) indagine sulle risorse paesaggistiche e sulle aree verdi della fascia costiera ligure. ist. archit. tecn. urban. fac. ingen.univ. genova c.n.r.,115 pp, 5 tav., scuola graf. don bosco genova. marini m. (2001) il pliocene ligure fra ventimiglia e bordighera (imperia, alpi marittime liguri): osservazioni preliminari. boll. soc. geol. it., 112200 (2001), 37-46. miyauchi t., dai pra g. & sylos labini s. (1994) geochronology of pleistocene marine terraces in the tyrrhenian coast of south calabria, italy. il quaternario, 77 (1/a), 17-34. negri a., pirini c., razzore s., bonci m.c. (1997) micropaleontological record in the pliocene of genoa-arenzano area. boll. soc. paleont. it., 3366 (1-2), 261-274. rovereto g. (1934) epirogenesi postpliocenica delle alpi marittime e della riviera ligure. rend. acc. naz. lincei, serie 6, 2200 (5-6), 153-157, roma. rovereto g. (1939) liguria geologica. mem. soc. geol. it., 22, 1-743. s.g.i. (1991) alpi liguri. guide geologiche regionali, 295 pp., be-ma ed. s.g.n. (1994) carta geomorfologica d’italia 1:50.000 guida al rilevamento. quad. s.iii, 44, 42 pp., ist.pol.zecca stato, roma 68 ms. ricevuto il 3 gennaio 2002 testo definitivo ricevuto il 26 marzo 2002. ms. received: genuary 3, 2002 final text received: march 26, 2002 carobene-firpo imp.bonfiglio bbiioo--cchhrroonnoollooggyy ooff pplleeiissttoocceennee vveerrtteebbrraattee ffaauunnaass ooff ssiicciillyy aanndd ccoorrrreellaattiioonn ooff vveerrtteebbrraattee bbeeaarriinngg ddeeppoossiittss wwiitthh mmaarriinnee ddeeppoossiittss llaauurraa bboonnffiigglliioo11,, cciipprriiaannoo ddii mmaaggggiioo22,, aannttoonneellllaa cciinnzziiaa mmaarrrraa11,, ffeeddeerriiccoo mmaassiinnii22 && ddaarriiaa ppeettrruussoo22 1dipartimento di scienze della terra università degli studi di messina, via sperone 31casella postale 54 98166 messina e-mail: lbonfiglio@unime.it 2dipartimento di geologia e geodesia, università degli studi di palermo, c.so tukory 131, 90134 palermo abstract the rich pleistocene fossil record of sicily allowed the construction of a fairly detailed bio-chronological frame that is dated by correlation of vertebrate bearing deposits with marine deposits by geochemical and radiometric dating too. actually, an important category of deposits is representative of transitional and neritic environments, frequently associated with a lagoon or swamp. limnic deposits related to small freshwater basins also occur, often in relation to coastal and fully marine deposits. numerous relationships have been found between the vertebrate bearing deposits and marine deposits, which can be correlated with the δ18o isotopic record and the main palaeogeographic events in sicily. at present five faunal complexes (f. c.), characterised by the occurrence of different taxa, have been recognised. the two older faunal complexes (monte pellegrino f.c., elephas falconeri f. c.) include taxa with differently marked endemic features. where correlated with marine sediments, the assemblages of the elephas falconeri f. c. are associated with deposits dated early middle pleistocene (comiso, spinagallo cave, san vito lo capo peninsula). in the younger f.c’xes (elephas mnaidriensis f.c., s. teodoro cave-pianetti f.c., and castello f. c.) faunal composition is becoming more similar to that of the southern italian peninsula and denotes that temporary connections with southern italy occurred. where correlated with sediment of marine environments, the assemblages of the e. mnaidriensis faunal complex are associated with deposits dated as late middle pleistocene and/or late pleistocene (s.ciro cave, maddalena peninsula, contrada cacaladritta, cape peloro, contrada fusco, coste di gigia, scodonì, san vito lo capo peninsula). the most likely time interval for the two faunal complex seems to be, respectively, from stage 22 to younger not defined oscillations of the oxygen isotope curve (elephas falconeri f.c.) and from early stage 6 to early stage 4 of δ18o isotopic record (elephas mnaidriensis f. c.). riassunto la ricca documentazione di vertebrati pleistocenici della sicilia ha permesso la costruzione di una dettagliata scala bio–cronologica, datata mediante correlazioni tra i depositi a vertebrati e depositi marini e mediante datazioni geochimiche e radiometriche. i depositi a vertebrati oltre che in ambiente di grotta, sono contenuti in depositi di ambiente neritico e di transizione, spesso associati ad ambienti palustri e/o salmastri. frequentemente i resti di vertebrati sono contenuti in depositi limnici relativi ad ambienti di piana costiera a loro volta correlati con depositi francamente marini. sono stati rinvenuti numerosi rapporti tra depositi a vertebrati e depositi marini correlabili con la curva degli isotopi stabili dell’ossigeno (δ18o) e con i maggiori eventi paleogeografici pleistocenici dell’isola. sono stati riconosciuti cinque complesi faunistici (c.f.) caratterizzati da differenti associazioni faunistiche. i due complessi faunistici più antichi (c. f. di monte pellegrino e c. f. a elephas falconeri), includono taxa a endemismo di entità differente. i depositi contenenti le associazioni faunistiche del c. f. a elephas falconeri sono correlabili a depositi marini della base del pleistocene medio (comiso, grotta di spinagallo, penisola di san vito lo capo). nei complessi faunistici più recenti (c. f. a elephas mnaidriensis, c. f. grotta di s. teodoropianetti e c. f. di castello) la composizione delle associazioni faunistiche diventa sempre più simile a quella dell’italia peninsulare e indica l’esistenza di connessioni temporanee con l’italia meridionale. i depositi a vertebrati del c. f. a e. mnaidriensis sono correlabili con depositi marini del tardo pleistocene medio e/o del pleistocene superiore (grotta di s.ciro, penisola della maddalena, contrada cacaladritta, capo peloro, contrada fusco, coste di gigia, scodonì, penisola di san vito lo capo). l’età più probabile per i due complessi faunistici risulta compresa, rispettivamente, dallo stadio 22 a una oscillazione più giovane, attualmente non definibile della curva degli isotopi stabili dell’ossigeno (δ18o ) (c. f. a elephas falconeri) e dall’inizio dello stadio 6 all’inizio dello stadio 4 della curva isotopica (c. f. a elephas mnaidriensis). keywords: pleistocene vertebrates, quaternary, sicily. parole chiave: vertebrati pleistocenici, quaternario, sicilia. il quaternario italian journal of quaternary sciences 1166(1bis), 2003, 107-114 11.. iinnttrroodduuccttiioonn up to 1985 most of the known pleistocene vertebrate remains of sicily came from cave deposits and little was known about the palaeoenvironmental conditions of the vertebrate-bearing deposits. chronological arrangements of the various pleistocene mammal assemblages of sicily were based on the assumption of the phyletic derivation of the dwarf elephant elephas falconeri from the middle sized elephas mnaidriensis, which was in turn considered a direct descendant of elephas antiquus (accordi, 1963; accordi, 1965; accordi & colacicchi, 1962; ambrosetti et al., 1980). vaufrey (1929) was inclined to assume a post-tyrrhenian age for all the vertebrate faunas. since the studies of accordi (1957; 1963; 1965) it was thought that most of the size reduction of elephants in sicily took place during the period preceding the tyrrhenian. the smallest species (elephas falconeri) was considered to be limited to the early würm period and to have evolved as a consequence of environmental stress linked to the würmian climatic cooling (ambrosetti, 1968; kotsakis, 1979). nevertheless, scinà (1831), vaufrey (1929), accordi & colacicchi (1962) and accordi (1963; 1965) 108 l. bonfiglio et al. provide interesting observations concerning the relationship between vertebrate-bearing deposits and littoral marine deposits. since 1985, a new synthesis has incorporated new stratigraphic and aminostratigraphic data (belluomini & bada, 1985; bada et al., 1991; burgio & cani, 1988; bonfiglio, 1987; bonfiglio, 1992 a; bonfiglio, 1992 b; bonfiglio & burgio, 1992; bonfiglio & insacco, 1992). taphonomic data show that pleistocene vertebrates were distributed in both cave environments and broad, open environments (bonfiglio, 1987;1992 a; 1992 b; 1995; bonfiglio et al., 1996; chilardi & gilotti, 1996a) and numerous relationships have been found between the vertebrate bearing deposits and terraced marine deposits, which can be correlated with the δ18o isotopic record and the main palaeogeographic events in sicily (agnesi et al., 1997; bonfiglio, 1991; bonfiglio et al., 2000; bonfiglio et al., 2002; di maggio et al., 1999). new data concern essentially the number and composition of the pleistocene faunal complexes and stratigraphical, environmental, taphonomic, chronological and palaeogeobiographical characters of the vertebrate-bearing deposits. 22.. ffaauunnaall ccoommpplleexxeess aanndd ppaallaaeeooggeeooggrraapphhyy the pleistocene vertebrate assemblages of sicily can be arranged into 5 phases or faunal complexes (f.c.), spanning from the early pleistocene to the late glacial (bonfiglio et al., 2000; bonfiglio et al., 2001; bonfiglio et al., 2002). the oldest quaternary faunal complex (monte pellegrino f. c.) is documented only in the very restricted geographic area of monte pellegrino, close to the town of palermo, where fossils are contained in small residual deposits of karst fissure. according to burgio & fiore (1997) the poorly diversif ied fauna is late villafranchian in age. the composition of the monte pellegrino fauna unique for the mediterranean islands suggests it may have been derived in part from an older, not locally known, population phase (messinian age ? azzaroli, 1974; azzaroli & guazzone, 1979) and partially from younger dispersals from europe. the different degree of endemism and the different geographical affinity of the taxa, indicate a polyphasic origin (masini et al. in press). the younger elephas falconeri faunal complex is even poorer than the preceding one in mammalian biodiversity. the poorly diversified fauna includes, besides the pigmy elephant, members of the genera crocidura, lutra, leithia, maltamys, a giant tortoise, and a rich typical endemic avifauna (pavia, 1999; pavia, 2000). neither the ancestor nor the geographic provenance of e. falconeri has been determined unequivocally and its possible origin from european elephas antiquus stock, or from a north african species is still a matter of discussion (bonfiglio & piperno, 1996). moreover, the composition of this faunal complex also reveals a polyphasic origin; some taxa are relics from the preceding phase and others are ‘newcomers’ that probably entered the island through a strongly filtering barrier (masini et al., in press). the subsequent elephas mnaidriensis faunal complex is almost completely renewed in respect to the preceding f. c. the pigmy e. falconeri is extinct, while the faunal composition is more balanced and includes top predators such as the lion and the spotted ‘cave’ hyena. the herbivores (bison, auroch, fallow deer, red deer, hippo) are moderately modified in respect to the congeneric or conspecific taxa from the italian mainland and the endemic nature of the fauna is apparent mainly from the modest reduction in size (abbazzi et al, 2001; bonfiglio et al., 2002). the small mammals, are represented by survivors from the e. falconeri f. c. (leithia, maltamys and crocidura esuae; kotsakis, 1996b, di maggio et al., 1999, petruso, 2001; petruso, in progress; masini et al., in press). one endemic species of bird, cygnus falconeri occurs, while the endemic species of the previous f. c. became extinct, except grus melitensis whose persistence is, however, questionable (pavia, 2000; 2001). amino-acid racemization dating yielded an age of 455 ± 90 ky for elephas falconeri from the spinagallo and luparello cave deposits while an age of 200 ± 40ky has been assigned to the elephas mnaidriensis f. c. by bada et al. (1991). esr dating for teeth enamel of elephas mnaidriensis and hippopotamus pentlandi from contrada fusco (rhodes, 1996) provided an age ranging between 146.8 ± 28.7 and 88.2 ± 19.5 ky. the fourth pleistocene faunal complex (san teodoro cave pianetti f. c.) dates to the last glacial cycle. the faunal history of this period is characterised by extinction events (hippopotamus, endemic dormice and crocidura esuae), and by the dispersal of equids (equus hydruntinus) and of mainland small mammals, which are represented by taxa still occurring in sicily (microtus (terricola) ex gr. savii, crocidura cf. sicula, apodemus cf. sylvaticus, erinaceus europaeus) (bonfiglio et al 1997; bonfiglio et al. 2001, petruso, in progress). almost all of the large mammals belonging to this f. c. seem to be inherited from elephas mnaidriensis f. c.. endemic species of avifauna are lacking (pavia, 2000). finally, the late glacial assemblages of the castello faunal complex show a dramatic decrease in diversity, missing all endemic large mammals still occurring in the s. teodoro cave-pianetti f. c. late glacial faunas, which are similar to continental ones, are associated to lithic artifacts and cultural evidences of late upper palaeolithic (kotsakis, 1979; bonfiglio & piperno, 1996). from the oldest to the youngest, the sicilian faunal complexes show a decreasing degree of endemism and a composition more and more similar to that of the southern italian peninsula . the geographic and stratigraphic distribution greatly varies in space and time (younger sites are much more numerous). such distribution pattern is typical in regions in which tectonic activity is very intense and is probably due to the different extension in time of the emerged areas, which implies sharp lateral variations of the depositional environments. the active extensional tectonic regime affecting sicily from the early pleistocene onwards resulted in the collapse of peripheral zones and lead to the creation of a series of deep marine basins which occupied large areas around and between two emerged blocks (north and south eastern areas, respectively). these two islands were of small extension as well as the related depositional environments. in fact, the number of the deposits containing the two oldest faunal complexes (m. pellegrino and elephas falconeri f.c.), which are early and early-middle pleistocene in age, is very low. conversely, the vertebrate bearing deposits of the latemiddle and early-late pleistocene assemblages (elephas mnaidriensis faunal complex) are very numerous, are contained in deposits of different environments and have a wide distribution all over the island (bonfiglio et al., 2002 with bibliography). from the beginning of the middle pleistocene onwards the evolution of sicily was characterised by a generalised uplift which led to the emersion of the previous deep marine basins and the island reached almost the present extension, being also bordered by a crown of coastal plains. for that reason, a large amount of the mammalian fossils of the elephas mnaidriensis f.c. are from upraised remnants of coastal plains as well as from caves and fissures. during the late pleistocene a strong uplift accompanied by the contemporaneous sea water low-standing led to the disappearance of humid environments of coastal plains. as a matter of fact the deposits of the youngest faunal complex (“s. teodoro cave-pianetti” and “castello” f. c.) are numerous, but they are limited to caves and fissures. the faunal composition of this complex is consistent with the disappearance of humid environments (coastal plains with lagoons or swamps) and the laying down of dry conditions. 33.. ccoorrrreellaattiioonn ooff ffaauunnaall ccoommpplleexxeess wwiitthh mmaarriinnee sseeddiimmeennttss most of the mammalian fossils of sicily are found in caves and fissures rather common in the carbonate mountain ranges of northern sicily and in the hyblean plateau. another important category of deposits is representative of transitional and neritic environments, frequently associated with a lagoon or swamp. limnic deposits related to small freshwater basins also occur, often in relation to coastal and fully marine deposits (fig. 1). the assemblages of the monte pellegrino f.c. and those of s. teodoro cave pianetti and castello 109bio-chronology of pleistocene vertebrate faunas ... f.c.’xes are contained in caves and fissure-filling deposits and they have no relationship with marine deposits. the assemblages of the elephas falconeri and of the elephas mnaidriensis f.c. ’xes are contained in cave deposits correlated with marine deposits, as well as in coastal plain and/or in marine littoral deposits (littoral marine sands, deltaic marine clay sands, deltaic marine gravels and sands) and in continental deposits overlying abrasion platforms. in the different environments the biodiversity, the preservation conditions and the concentration of the skeletal remains are very diverse. 33..11 eelleepphhaass ffaallccoonneerrii ff..cc.. aasssseemmbbllaaggeess ccoorrrreellaatteedd wwiitthh mmaarriinnee sseeddiimmeennttss at comiso a regressive marine sequence begins with early pleistocene marine deposits and ends at the top with sands of brackish environment which, in turn, pass to deposits of limnic environment underlying middle pleistocene marine sands (conti et al., 1980; carbone et al., 1982). in the different levels of the limnic deposits skeletal elements of elephas falconeri, leithia melitensis, bats, fishes, birds, reptiles (lacerta sp., testudo sp., emys orbicularis, geochelone sp.) are contained (bonfiglio & insacco, 1992). the continental limnic succession at comiso, made up by palaesols, lacustrine and aeolian deposits, constitutes the evidence of the first connection of the hyblean plateau to the sici l ian mainland in the pleistocene. this connection occurred after the deposition all around the plateau of the plio-pleistocene marine deposits, which end with clays and sands of the latest early pleistocene (di geronimo et al., 1979; conti et al. 1980). the limnic deposits contain the first occurrence of the elephas falconeri faunal complex (bonfiglio & insacco, 1992). the terrestrial gastropods from the limnical deposits of comiso, indicating wet and cool environment, were attributed by esu & girotti (1991) to the earliest middle pleistocene. at spinagallo cave, the lower vertebrate deposits containing abundant remains of elephas falconeri associated with leithia melitensis, maltamys gr. gollcheriwiedincitensis, crocidura esuae, testudo hermanni overlie early middle pleistocene littoral calcarenites (accordi & colacicchi, 1962; petronio, 1970; kotsakis, 1977; 1986; kotsakis & petronio, 1981; di grande & raimondo, 1984; bonfiglio, 1992 b; petruso, in progress). the limnical deposits at comiso may correspond to the beginning of the "roman regression" (ruggieri et al., 1975) that roughly correlates with stage 22 of δ18o isotopic record, while the e. falconeri bearing deposits at spinagallo cave may correspond to younger oscillations of the oxygen isotope curve. at san vito lo capo peninsula several littoral and continental mammal bearing deposits are present and related to a well preserved marine terrace sequence early to late pleistocene in age. the terrace succession, composed of seven orders of abrasion surfaces, has been studied in detail by some authors (antonioli et al., 1998a, b; di maggio et al., 1999) that proposed a correlation with ios succession. di maggio et al. (1999) analysed the vertebrate deposits and their stratigraphic relationships to such terrace sequence. from the middle to the late pleistocene a tectonic activity affected the fig. 1 location of the vertebrate-bearing deposits correlated with marine deposits in sicily quoted in the text. 110 area moderately dislocating the ancient shorelines. mammal remains of the elephas falconeri f. c. have been found in morphological traps (caves and wave cut notches) in the piana di sopra area, where the terrace sequence is fairly complete and the ancient shoreline remains are quite well preserved. elephas falconeri and leithia melitensis remains occur in paleosols deposits overlying a coastal conglomerate preserved in an ancient wave cut notch at 45 m a.s.l. (semaforo site). a dental remain of elephas falconeri has been found within a beach conglomerate resting on the floor of a marine cave opened at about 72 m a.s.l in the palaeocliff bordering the southern side of piana di sopra (isolidda 2 site). according to the reconstruction of the palaeogeographic evolution of the area di maggio et al. (1999) referred both mammal deposits to the second order terrace. even though the correlation with the ios record is affected by some uncertainties, this terrace can be confidently related to one of the stages comprised between ios 15 and ios 11. the biocronological events that mark the end of elephas falconeri f. c. are still poorly defined. the extinction of e. falconeri might be the result of predation consequent to the dispersal of the large carnivores of the succeeding elephas mnaidriensis faunal complex. 33..22 eelleepphhaass mmnnaaiiddrriieennssiiss ff..cc.. aasssseemmbbllaaggeess ccoorrrreellaatteedd wwiitthh mmaarriinnee sseeddiimmeennttss the most important recent finding of vertebrate bearing deposits containing faunal remains of the elephas mnaidriensis f.c. is that of contrada fusco, located south to the hill of neapolis, to the west of syracuse, where a very rich faunal assemblage (an elephant of little reduced size, elephas mnaidriensis, hippopotamus pentlandi, ursus cf. arctos, crocuta crocuta spelaea, lutra trinacriae, leithia melitensis, maltamys wiedincitensis, crocidura esuae, emys orbicularis, testudo cfr. hermanni, lacerta siculomelitensis, natrix sp.) comes from a stratigraphic sequence cropping in three low hills (respectively, eastern sector, tor di conte and western sector), separated by fluvial incisions. the coastal plain deposits overl ie early pleistocene bathyal clays and underlie tyrrhenian calcarenites (chilardi & gilotti, 1996 a; 1996 b; chilardi, 1996 a; kotsakis, 1996 a; 1996 b; cassoli & tagliacozzo, 1996 a; 1996 b). the stratigraphic section (chilardi & gilotti, 1996 a, fig. 1, p. 26) includes six sedimentary units (l1, all, c3, c4, l2, l3) interbedded between the marine substrate, early pleistocene in age, and overlying littoral calcarenites attributed by di grande & raimondo (1974) to the thyrrhenian. according to chilardi & gilotti (1996 a) the deposition of continental silts (l1), containing scarce vertebrate remains, and fluvial conglomerates (all), containing numerous skeletal elements of large mammals, is followed by a marine ingression, which lead to the deposition of marine biocalcarenites of shallow water environment (c3) eteropic of gravels and sands of back-shore environment (c4). the overlying silts of marsh environments (l2) are attributed to a marine regression to which a successive marine ingression follows, represented by brackish lagoons (l3). however, carefully looking to fig. 1, p. 26 in chilardi & gilotti (1996 a) and to the palaeontological and taphonomical characteristics of the deposits, the six sedimentary units probably represent the different sedimentary facies of a late middle pleistocene coastal plain which gradually became subsiding before the deposition of tyrrhenian calcarenites. at contrada fusco together with the remains of elephas mnaidriensis, remains of a larger elephant (elephas sp.) have been collected (chilardi, 1997) which may represent the first arrival of continental species not yet reduced in size of the elephas mnaidriensis f.c. the “paleosoil” containing remains of elephas mnaidriensis (accordi, 1963; 1965) underlying tyrrhenian calcarenites at maddalena peninsula (castelluccio lighthouse) probably belong to the same coastal plain which extended south of the hill of neapolis. actually several fossil remains have been signalled by de gregorio (1924-25) south of c.da fusco in the the anapo river valley where pleistocene alluvial conglomerates underlie tyrrhenian calcarenites (chilardi, 1996 b). an isolated scapula of elephas mnaidriensis comes from thyrrhenian marine deposits at maddalena peninsula (accordi, 1963). according to di grande & raimondo (1984) the present highest altitude of the thyrrhenian “ calcarenites of targia ” in the area of neapolis-maddalena peninsula is about 25 m. north to contrada fusco, at coste di gigia, the red clays containing hippopotamus pentlandi and elephas mnaidriensis overlie late middle pleistocene littoral gravels and calcarenites and a small wave-cut platform relative to a shore line located at 40 m a.s.l. calcarenites and abrasion platform are cut by the younger tyrrhenian abrasion platform which presents its inner margin at the altitude of 34 m a.s.l. again the faunal assemblage of the elephas mnaidriensis f.c. is late middle pleistocene in age (bonfiglio, 1992 b). the different position of tyrrhenian calcarenites in respect to mammal bearing deposits at coste di gigia and at contrada fusco is due to the location of the two sites in areas with different uplift rate, respectively the priolo depression and the floridia graben (di geronimo et al., 1980; carbone et al., 1982). in the late pleistocene sandy gravel outside the s. ciro cave, the rare hippopotamus and elephant remains (molars, limbs) are disarticulated, encrusted by serpulid polychaetes worms and associated with a rich marine fauna containing gastropods, bivalves, ostracods, foraminifera, of littoral euryhaline environment (galletti & scaletta, 1991). at s. ciro cave the vertebrate assemblage contains abundant remains of hippopotamus pentlandi associated with rare remains of elephas mnaidriensis, cervus siciliae, dama carburangelensis, bos primigenius siciliae, canis lupus, ursus cfr. arctos, crocuta spelaea (scinà, 1831; fabiani, 1928). the marine sands and the wave cut notch with lithodomus holes, brought to light by scinà (1831) at the bottom of the cave deposits, probably have a middle pleistocene age. at contrada cacaladritta rare skeletal remains of hippopotamus pentlandi, elephas cf. mnaidriensis and bos primigenius siciliae are concentrated in deltaic clayey sands with ostrea edulis that underlie gravelly, sandy and calcareous continental deposits with fresh water mollusks. the two units constitute the uppermost middle pleistocene portion of a regressive marine sequence, which begins with early pleistocene clays of bathyal environment (bonfiglio et al., 1996, with bibliol. bonfiglio et al. 111 graphy). disarticulated, fragmented, worn and mechanically selected remains of elephant (elephas mnaidriensis), hippopotamus (hippopotamus pentlandi), red deer (cervus elaphus siciliae), bear (ursus cf. arctos), tortoise (testudo cf. hermanni) are contained in the deltaic marine gravel and sandy deposits underlying thyrrhenian sands with strombus bubonius at cape peloro. serpulids encrust some skeletal elements (bonfiglio & berdar, 1979; bonfiglio & violanti, 1986; marra, 2001). at acquedolci gravels and silty laminated lacustrine deposits overlie a wave-cut platform and beach gravels relative to a shore line located at 130 m a.s.l and contain very abundant skeletal elements of the endemic hippo hippopotamus pentlandi associated with scarce remains of cervus elaphus siciliae, ursus cfr. arctos, canis lupus, elephas mnaidriensis, testudo cfr. hermanni, birds. the vertebrate bearing deposits, the abrasion platform and the beach gravels are in turn cut by the younger tyrrhenian abrasion platform which in this area presents its inner margin at the altitude of 105 m a.s.l. (bonfiglio, 1992 a; bonfiglio, 1995). at scodonì, east to acquedolci, fluvial gravels containing abundant remains of hippopotamus pentlandi associated with scarce remains of ursus cfr. arctos, overlie the large tyrrhenian abrasion platforms extended between 80 and 105 m a.s.l. (bonfiglio, 1987) at san vito lo capo peninsula, eutyrrhenian deposits and/or abrasion platforms are well represented and continuously distributed at a height comprised between 0 and 18 m a.s.l. (sixth order terrace). within such deposits a rich “senegalese” fauna including strombus bubonius and patella ferruginea locally occurs. at seno dell ’arena site scant remains of dama carburangelensis are encrusted above the eutyrrhenian abrasion surface at 10 m a.s.l. at caletta cofano remains of elephas mnaidriensis, bos primigenius and crocuta crocuta occur at about 1-2 m a.s.l. within a continental succession composed by paleosol sediments alternated to stone lines overlying marine calcarenites. the abrasion surface, on which the continental deposit lies, is correlated with ios 5a or 5c (di maggio et al., 1999). all these data represent the evidence that the first occurrence of the elephas mnaidriensis f.c. in the island is late middle pleistocene in age and that this elephant survived the eutyrrhenian interglacial. stratigraphical correlations at acquedolci, s. ciro cave, coste di gigia show that the e. mnaidriensis assemblages are found in late middle pleistocene terraced deposits overlying a shoreline which probably corresponds to ios 7 (bonfiglio, 1991). chronostratigraphical data concerning the last occurrences of the taxa of this faunal complex are still poorly defined, but significant evidence come from s. teodoro cave and contrada pianetti. at these sites the highly diversified assemblage of vertebrates (elephant, horse, wild ox, deer, wild boar, hyena, fox, mice, ground vole, shrew, hedgehog, bats, birds, reptiles) invertebrates and vegetal remains lacks hippopotamus, endemic dormice and crocidura esuae. the assemblage of small mammals is completely renewed in respect to that of the e. mnaidriensis faunal complex, and includes not endemic taxa such as microtus (terricola) ex gr. savii, apodemus, erinaceus and crocidura cf. sicula (bonfiglio et al., 1997; bonfiglio et al., 2001). the association of the elephant (elephas mnaidriensis) with the equid (equus hydruntinus), which were previously thought to represent the typical taxa of two different faunal complexes (the endemic elephas mnaidriensis faunal complex and the younger, not endemic, castello faunal complex), evidences a longer survival of the elephant and the associated taxa in sicily. the combined occurrence of taxa up to now considered as typical, or exclusive, of two contiguous faunal complexes (elephas mnaidriensis and castello f.c.’s) can be explained by the occurrence of a dispersal event posterior to ios 5e. geochemical and radiometric dating are not available and the deposits of the large s.teodoro cave are still to be more extensively investigated. the most likely time interval for this faunal complex is from early ios 6 to early ios 4. bio-chronology of pleistocene vertebrate faunas ... fig. 2 – chronological correlation frame of the vertebrate-bearing deposits with marine deposits in sicily (from di maggio et al., modified). 112 44.. ccoonncclluussiioonn in sicily numerous relationships have been found between the faunal assemblages of two faunal complexes (elephas falconeri f.c. and elephas mnaidriensis f. c.) and marine deposits, which can be correlated with the δ18o isotopic record and the main palaeogeographic events in sicily (fig. 2). vertebrate are contained in deposits of transitional and neritic environments, frequently associated with a lagoon or swamp. limnic deposits related to small freshwater basins also occur, often in relation to coastal and fully marine deposits. where correlated with marine sediments, the assemblages of the elephas falconeri f. c. are associated with deposits dated early middle pleistocene (comiso, spinagallo cave, san vito lo capo peninsula) while the assemblages of the e. mnaidriensis faunal complex are associated with deposits dated as late middle pleistocene and/or late pleistocene (acquedolci, s.ciro cave, maddalena peninsula, cape peloro, contrada fusco, coste di gigia, scodonì, san vito lo capo peninsula). the most likely time interval for the two faunal complex seems to be, respectively, from stage 22 to younger not defined oscillations of the oxygen isotope curve (elephas falconeri f.c.) and from early stage 6 to early stage 4 of δ18o isotopic record (elephas mnaidriensis f. c.). work supported by grants pra, university of messina (l. bonfiglio). cciitteedd rreeffeerreenncceess abbazzi l., bonfiglio l., marra a. c. & masini f., 2001 a revision of medium and small sized deer from the middle and late pleistocene of calabria and sicily. bollettino della società paleontologica italiana, 4400 (2), 115-126. accordi b., 1957 nuovi resti di ippopotamo nano nel pleistocene dei dintorni di siracusa. atti accademia gioenia di scienze naturali, 1111, 99109. accordi b., 1963 rapporti tra il "milazziano" della costa iblea (sicilia sud-orientale) e la comparsa di elephas mnaidriensis. geologica romana, 22, 295304. accordi b., 1965 some data on the pleistocene stratigraphy and related pigmy mammalian faunas of eastern sicily. quaternaria, 66, 415-430. accordi b. & colacicchi r., 1962 excavations in the pygmy elephants cave of spinagallo (siracusa). geologica romana, 11, 217-230. agnesi v., macaluso t., masini f., 1997 l’ambiente e il clima della sicilia nell’ultimo milione di anni. in s. tusa (ed.) prima sicilia. alle origini della società siciliana, vol. i. siracusa, ediprint, 1997, 31-56 ambrosetti p., 1968 the pleistocene dwarf elephants of spinagallo (siracusa, south eastern sicily). geologica romana, 77, 277-398. ambrosetti p., azzaroli a., kotsakis t., 1980 mammiferi del plio-pleistocene delle isole italiane. in "i vertebrati fossili italiani", catalogo della mostra, verona, 243-248. antonioli f., cremona g., pugliesi c., silenzi s., valpreda e., verrubi b., 1998 valutazione quantitativa di movimenti crostali differenziali quaternari nell’area costiera del promontorio di san vito lo capo (nw sicilia). atti 79° congresso nazionale della soc. geol. it., palermo 21-23 sett. 1998, vol. a, 70-73. azzaroli a., 1974 late miocene interchange of terrestrial fauna across the mediterranean. memorie società geologica italiana, 1133 (suppl. 2),261-265. azzaroli a. & guazzone g., 1979 terrestrial mammals and land connections in the mediterranean before and during the messinian. palaeogeography palaeoclimatology palaeoecology, 2299, 155-167. bada j. l., belluomini g., bonfiglio l., branca m., burgio e. & delitala l., 1991 isoleucine epimerization ages of quaternary mammals of sicily. il quaternario, 44 ((11aa)), 5-11. belluomini g. & bada j. l., 1985 isoleucine epimerization ages of the dwarf elephants of sicily. geology, 1133, 451-452. bonfiglio l., 1987 nuovi elementi faunistici e stratigrafici del pleistocene superiore dei nebrodi (sicilia nord-orientale). rivista italiana di paleontologia e stratigrafia, 9933 ((11)), 145-164. bonfigl io l., 1991 correlazioni tra deposit i a mammiferi, depositi marini, linee di costa e terrazzi medio e tardopleistocenici nella sicilia orientale. il quaternario, 44 ((11bb)),, 205-214. bonfiglio l., 1992a campagna di scavo 1987 nel deposito pleistocenico a hippopotamus pentlandi di acquedolci (sicilia nord-orientale). bollettino della società paleontologica italiana, 30 (3), 157-173. bonfiglio l., 1992b middle and upper pleistocene mammal-bearing deposits in south-eastern sicily: new stratigraphical records from coste di gigia (syracuse). geobios, 1144,, 189-199. bonfiglio l., 1995 taphonomy and depositional setting of pleistocene mammal-bearing deposits from acquedolci (north-eastern sicily). geobios, 1188,, 57-68. bonfiglio l. & berdar a., 1979 gli elefanti delle ghiaie pleistoceniche di messina. quaternaria, 2211,, 139177. bonfiglio l. & burgio e., 1992 significato paleoambientale e cronologico delle mammalofaune pleistoceniche della sicilia in relazione all'evoluzione paleogeografica. il quaternario, 55 ((22)), 223-234. bonfiglio l., di geronimo s., insacco g. & marra a. c. , 1996 large mammal remains from late middle pleistocene deposits of sicily: new stratigraphic evidence from the western edge of the hyblean plateau (southeastern sicily). rivista italiana di paleontologia e stratigrafia, 110022 ((33)), 375-384. bonfiglio l. & insacco g., 1992 palaeoenvironmental, paleontologic and stratigraphic significance of vertebrate remains in pleistocene limnic and alluvial deposits from south eastern sici ly. palaeogeography, palaeoclimatology, palaeoecology, 9955, 195-208. bonfiglio l., insacco g., marra a. c. & masini f., 1997 large and small mammals, amphibians, reptiles from a new fissure filling deposit of the hyblean plateau (south eastern sicily). bollettino della l. bonfiglio et al. società paleontologica italiana, 3355 ((11)), 97-122. bonfiglio l., mangano g., marra a. c. & masini f., 2001 a new late pleistocene vertebrate faunal complex from sicily (s. teodoro cave, north-eastern sicily, italy). bollettino della società paleontologica italiana, 4400 ((22)), 149-158. bonfiglio l., marra a. c. & masini f., 2000 the contribution of quaternary vertebrates to the paleoenvironmental and paleoclimatic reconstructions in sicily. in hart m. b. (ed.) climates: past and present. geological society, london, special publications, 118811, 169-182. bonfiglio l., mangano g., marra a. c., masini f., pavia m. & petruso d., 2002 pleistocene calabrian and sicilian bioprovinces. geobios special memoires n° 24, 3355, 29-39. bonfiglio l. & piperno m., 1996 early faunal and human populations. in leighton r. (ed.), early societies in sicily, university of london, accordia: 2129. bonfiglio l. & violanti d., 1986 prima segnalazione di tirreniano ed evoluzione pleistocenica del capo peloro (sicilia nord-orientale). geogr. fis. dinam. quat., 66, 3-15. burgio e. & cani m., 1988 sul ritrovamento di elefanti fossili ad alcamo (trapani, sicilia). il naturalista siciliano, 1122 ((33--44)), 87-97. burgio e. & fiore m.,1997 pannonictis arzilla (de gregorio 1886) a “villafranchian” element in the fauna from monte pellegrino (palermo, sicily). il quaternario, 10, 65-74. carbone s., di geronimo i., grasso m., iozzia s. & lentini f., 1982 i terrazzi marini quaternari dell'area iblea (sicilia sud-orientale). contributi conclusivi per la realizzazione della carta neotettonica d'italia, pubbl. n. 550066 del progetto finalizzato geodinamica. cassoli p.f. & tagliacozzo a., 1996 al'avifauna. in: basile, b. & chilardi s. (eds.) le ossa dei giganti. lo scavo paleontologico di contrada fusco. siracusa: arnaldo lombardi, 1996, 61-67. cassoli, p.f. & tagliacozzo a., 1996 b l'ittiofauna. in: basile, b. & s. chilardi, eds. le ossa dei giganti. lo scavo paleontologico di contrada fusco. siracusa: arnaldo lombardi, 1996, 55-54. chilardi s., 1996 a i macromammiferi. in: basile, b. & s. chilardi, eds. le ossa dei giganti. lo scavo paleontologico di contrada fusco. siracusa: arnaldo lombardi, 1996, 73-80. chilardi s., 1996 b i siti paleontologici del territorio siracusano. in: basile, b. & s. chilardi (eds.) le ossa dei giganti. lo scavo paleontologico di contrada fusco. siracusa, arnaldo lombardi, 1996, 87-91. chilardi s., 1997 le faune pleistoceniche di contrada fusco. in s. tusa (ed.) prima sicilia. alle origini della società siciliana, vol. i. siracusa: ediprint, 1997, 77-81. chilardi s. & gilotti a, 1996a stratigrafia e sedimentologia. in: basile b. & chilardi s., (eds.) le ossa dei giganti. lo scavo paleontologico di contrada fusco. siracusa: arnaldo lombardi, 1996, 27-34. chilardi s. & gilotti a., 1996b a new important palaeontological site of mediterranean basin: preliminary results from contrada fusco (siracusa, southeastern sici ly). second international symposium on the conservation of our geological heritage, rome, abstract book, 24. conti m. a., di geronimo i., esu d. & grasso m., 1980 il pleistocene in facies limnica di vittoria (sicilia meridionale). geologica romana, 1188, 93-104. de gregorio a., 1924-1925 mammiferi quaternari di sicilia. annales de géologie et de paléontologie, v. 3388--4433.. di geronimo i., ghisetti f., lentini f., vezzani l., 1979 lineamenti tettonici della sicilia orientale. mem. soc. geol. it., 1199, 543-549. di geronimo i., ghisetti f., grasso m., lentini f., scamarda g. & vezzani l. 1980 dati preliminari sulla tettonica della sicilia sud-orientale. fogli 273 (caltagirone), 274 (siracusa), 275 (scoglitti), 276 (ragusa) e 277 (noto). contributi preliminari alla realizzazione della carta neotettonica d'italia, progetto finalizzato geodinamica, napoli, 335566, 747-773. di grande a. & raimondo w., 1984 linee di costa plio-pleistoceniche e schema litostratigrafico del quaternario siracusano. geologica romana, 2211, 279-309. di maggio c., incandela a., masini f., petruso d., renda p., simonelli c. & boschian g., 1999 oscillazioni eustatiche, biocronologia dei depositi continentali quaternari e neotettonica nella sicilia nord occidentale (penisola di san vito lo capo trapani). il quaternario, 1122 ((11)), 25-50. esu d. & girott i o., 1991 late pliocene and pleistocene assemblages of continental molluscs in italy. a survey. il quaternario, 44 (1 a), 137-150. fabiani r., 1928 cenni sulle raccolte di mammiferi quaternari del museo geologico dell'università di palermo e sui risultati di nuovi saggi esplorativi. boll. ass. miner. sicil., 44, 25-34. galletti l. & scaletta c., 1991 descrizione di una sequenza del pleistocene superiore con fauna continentale a san ciro-maredolce (palermo). il naturalista siciliano, 1155 (1-2), 3-10. kotsakis t., 1977 i resti di anfibi e rettili pleistocenici della grotta di spinagallo (siracusa, italia). geologica romana, 1166, 211-229. kotsakis t., 1979 sulle mammalofaune quaternarie siciliane. bollettino del servizio geologico italiano, 9999, 263-276. kotsakis t., 1986 crocidura esui n. sp. (soricidae, insectivora) du pléistocène supérieur de spinagallo (sicilia orientale, italie). geologica romana, 2233, 51-64. kotsakis t., 1996a anfibi e rettili. in: basile b. & chilardi s. (eds.) le ossa dei giganti. lo scavo paleontologico di contrada fusco. siracusa: arnaldo lombardi, 56-60. kotsakis t., 1996b i micromammiferi. in: basile, b. & chilardi s. (eds.) le ossa dei giganti. lo scavo paleontologico di contrada fusco. siracusa: arnaldo lombardi, 68-72 kotsakis t. and petronio c., 1981 i chirotterri del pleistocene superiore della grotta di spinagallo (siracusa, sici l ia). bollett ino del servizio geologico d'italia, 110011, 49-76. marra a. c., 2001 resti di vertebrati delle ghiaie pleistoceniche della formazione di messina (sicilia 113bio-chronology of pleistocene vertebrate faunas ... nord-orientale). il naturalista siciliano, s. iv, 2255 (1-2), 3-13. masini f., bonfiglio l, petruso d., marra a.c., f., abbazzi l, torre d., 2000, in press the role of coastal areas in the neogene quaternary mammal island populations of the central mediterranean . biogeographia. pavia m., 1999 the middle-pleistocene avifauna of spinagallo cave (sicily, italy): preliminary report. smithsonian contributions to paleobiology, 8899,, 125-127 pavia m., 2000 le avifaune pleistoceniche dell’italia meridionale. unpublished phd dissertation, university of torino, xiii cycle, 150 pags. pavia m., 2001 middle pleistocene fossil avifauna from the elephas mnaidriensis faunal complex of sicily (italy): preliminary results. the world of elephants, 1st international congress (rome, october 16th20th, 2001), abstract book. petronio, c., 1970 i roditori pleistocenici della grotta di spinagallo (siracusa). geologica romana, 99, 149194. petruso d., 2001 i ghiri della sicilia antica. in sarà m. (ed.) ghiri in sicilia: ecologia e conservazione. wwf, 27-41. petruso d., in progress stratigrafia e paleogeografia del quaternario continentale siciliano: il contributo dei micromammiferi. phd dissertation in geological science, universities of naples and palermo. rhodes e. j., 1996 esr dating of tooth enamel. in basile b. & chilardi s. (eds.), le ossa dei giganti. lo scavo paleontologico di contrada fusco. arnaldo lombardi, siracusa, 39-44. ruggieri g., unti a., unti m., moroni a., 1975 la calcarenite di marsala (pleistocene inferiore) e i terreni contermini. bollettino della società geologica italiana, 9944, 1623-1627. scinà d., 1831 rapporto sulle ossa fossil i di maredolce e degli altri contorni di palermo. dalla reale tipografia di guerra, palermo. vaufrey r., 1929 les éléphants nains des iles mediterranèennes et la question des isthmes pléistocènes. archives de l ’ institut de paléontologie humaine, paris, 66, 1-220. 114 l. bonfiglio et al. imp.diligenti& geomorphosites in the landscape of monti del furlo (northern marche apennines) antonio diligenti1, olivia nesci1 & daniele savelli1 1istituto di geologia, università degli studi “carlo bo”, campus scientifico, loc. crocicchia, 61029 urbino d.savelli@uniurb.it abstract: a. diligenti et al., geomorphosites in the landscape of monti del furlo (northern marche apennines). (it issn 0394-3356, 2005). three geomorphosites pertaining to the monti del furlo are taken into consideration. such area embraces the northernmost sector of an extended anticline ridge and is almost entirely included into a recently created natural national reserve. it is therefore clear how important it is in a naturalistic perspective. moreover, the cultural importance of this site is stressed by the roman via flaminia archaeological remains. this area also benefits from a great geologic/palaeontologic relevance, besides being really notable from a geomorphologic standpoint. in actual fact, the mountain ridge in hand is transversally cut by the furlo gorge, one of the most valuable and attractive geomorphosites in the marche apennines. furthermore, this important site can be associated with two other areas which, although not so remarkable as the furlo gorge, are worth improving as geomorphosites on account of their peculiar scientific, educational and scenic value. riassunto: a. diligenti et al., geomorfositi nel paesaggio dei monti del furlo (appennino marchigiano settentrionale). (it issn 03943356, 2005). il rilievo anticlinale dei monti del furlo è conosciuto principalmente per la famosa omonima gola incisa profondamente dal fiume candigliano attraverso i terreni giurassici-paleogenici della successione umbro-marchigiana. il territorio dei monti del furlo possiede un patrimonio geologico (peculiarità strutturali e stratigrafiche e famose località fossilifere), biologico (particolari specie floristiche e faunistiche) e geomorfologico (la gola e i paesaggi circostanti) che si integrano felicemente con paesaggi spettacolari, oltre a inserirsi in un contesto di notevole significato storico-archeologico (per esempio la via flaminia romana che attraversa la gola). i monti del furlo, anche per questi motivi, sono stati elevati al rango di riserva naturale statale al cui interno sono inseriti anche molti sentieri ed itinerari consigliati per l’osservazione delle caratteristiche naturali più rilevanti. la gola del furlo rappresenta un magnifico esempio di gola diaclinalica, forma molto caratteristica e abbastanza comune nei paesaggi appenninici marchigiani. per questo è stata scelta nell’ambito del progetto ministeriale “geositi nel paesaggio italiano” come geomorfosito da studiare, conservare e valorizzare. il presente lavoro vuole evidenziare il ruolo fondamentale che tale sito possiede nella comprensione dell’evoluzione del paesaggio marchigiano, in particolare per la genesi delle gole trasversali alle strutture tettoniche. al suo interno sono localizzati e descritti elementi geomorfologici caratterizzanti e peculiari che sono componenti chiave nella interpretazione del paesaggio e contribuiscono inoltre alla bellezza scenica del geomorfosito. nelle vicinanze della gola, sempre all’interno della riserva naturale, sono stati individuati altri due geomorfositi, la valle de “il buzzo” e la frana di ca i fabbri, che, oltre a costituire individualmente aree di rilevante interesse geomorfologico, contribuiscono contestualmente alla conoscenza dell’intero paesaggio dei monti del furlo. keywords: geomorphosites, furlo gorge, marche apennines. parole chiave: geomorfositi, gola del furlo, appennino marchigiano. il quaternario italian journal of quaternary sciences 18(1), 2005 volume speciale, 203-211 1. foreword the anticline mountains of pietralata-paganuccio mts. (respectively 888 and 976 m high, here called “monti del furlo”, according to a local designation) are well-known primarily for housing the famous furlo gorge, a striking canyon deeply cut by the candigliano river (metauro river basin) across the jurassicpaleogene calcareous and marly-calcareous formations of the autochthon umbria-marche succession. the furlo gorge cross-cuts an anticline mountain ridge (figs. 1, 2): with the frasassi one (famous for its amazing caves above all), it is the best example of such puzzling landforms so characteristic of central italy. besides, it is one of the best geomorphosites (sensu panizza, 2001, i.e. “a site of special geomorphologic interest”) in the marche apennines. although impressive as well as crucial to the unravell ing of plioquaternary evolution of this sector of the apennines, the gorge is not the sole geomorphologic peculiarity of the monti del furlo area. indeed, other valuable areas (worth improving as geomorphosites) do occur in its vicinity (cf. fig. 2), giving the gorge itself a surplus value. hence, in short, the area under discussion can be considered as encompassing more than one geomorphosite of greater or lesser geomorphologic relevance, each contributing to the geomorphologic evaluation of the whole. in turn, each geomorphosite comprises several individual, characterising landforms and/or landform associations of either scientific-educational importance or scenic relevance. more to the point, the monti del furlo area holds a major geologicpalaeontologic (e.g. structural and stratigraphic peculiarities and famous fossiliferous sites), naturalistic (e.g. 204 a. diligenti et al. fig. 1 geologic sketch of the northern marche region and location of the areas discussed in the text. schema geologico dell’area nord-marchigiana e ubicazione delle aree trattate nel testo. fig. 2 shaded relief of the monti del furlo anticline ridge with the location of the geomorphosites described in the text. the dotted line indicates the boundary of the study area. modello digitale della dorsale anticlinalica dei monti del furlo con l’ubicazione dei geomorfositi descritti nel testo. la linea puntinata indica il limite dell’area considerata nella presente nota. occurrence of floristic and faunal peculiarities), landscape (e.g. the gorge itself and the surrounding scenery) and historical-archaeological (e.g. the roman via flaminia remnants) relevance as well. these very essentials of both the furlo gorge and its environs have recently made this area become a national natural reserve (riserva naturale statale della gola del furlo), thereby arousing a great and renewed interest of both national and international communities. hence the monti del furlo area as a whole can be regarded as a “landscape unit” (cf. panizza & piacente, 2003, p. 264), where the geomorphologic constituents integrate into a wider naturalistic and historical-cultural geographic context. therefore, in the framework of the miur cofinanced project “the geosites of the italian landscape: research, evaluation and enhancement” the urbino research group, taking its cue from such basics and allowing for the global geosites inventory outlines (wimbledon, 1999), has accounted the monti del furlo as an area of primary geomorphologic relevance, proposing three individual geomorphosites and adopting this sector of the marche apennines as a sample-area for a targeted geomorphologic mapping. 205geomorphosites in the landscape ... 2. geologic framework the marche regional territory is characterised by a hilly coastal zone, where slightly deformed plioquaternary terrains predominate, merging to the southeast into a mountain chain area mostly corresponding to meso-cenozoic folded and thrusted formations of the autochthon umbria-marche apennines domain. it is characterised by two main ridges striking in a c.ca nw-se direction, the umbria-marche ridge (to the sw) and the marche ridge auct. (fig. 1), divided from each other by a broad topographic depression (cf. bisci & dramis, 1991 and references therein); several minor ridges either join the major ones flanks or stand on the inter-ridge depression (cf. fig. 1). both the major and the minor ridges consist of mesozoic-paleogene mainly carbonate and marly-calcareous units of the umbriamarche succession and correspond to asymmetric, mostly thrusted, ne-vergent anticlinoria (cf. deiana & pialli, 1994 and references therein). the monti del furlo area overlaps the northwestern termination of the marche ridge and consists of both the paganuccio and pietralata anticline mountains, divided by the furlo gorge (figs. 1, 2, 3). the paganuccio mt.-pietralata mt. (i.e. monti del furlo) anticline, characterized by an average n120 axial trend, is a slightly asymmetric box fold lacking in any clear evidence of major emergent thrusts on the forelimb. as a rule, the anticline, plunging both to the nw (anticline periclinal closure) and to the se (an axial depression), shows a marked local axial culmination in close proximity to the furlo gorge. the area at issue consists (cf. cecca et al., 1999) of carbonates, cherty carbonates, marls and calcareous marls of the umbria marche succession (figs. 3, 4), unconformably covered by a discontinuous and relatively thin mantle of quaternary alluvium and slope deposits. the lower-jurassic calcare massiccio formation, an over 500 m thick unit in which the furlo gorge is entrenched (cf. figs. 3, 4), consists of massive dolomitic limestones of carbonate platform environment and is the oldest outcropping unit. it is overlain by a c.ca 600700 m thick sedimentary “multilayer” extending from the lower jurassic up to the lower miocene, consisting of calcareous/marly-calcareous units alternating with marly/marly-calcaraeous ones. the jurassic units, ranging from the calcare massiccio up to the base of the maiolica formation, show rather complex facies associations and significant lateral lithostratigrafic differentiation (cf. cecca et al., 1999 and references therein), hinting at local depositional environments matching up with a fault-block seamount slope. on the contrary, the cretaceous-miocene units (from the midupper part of the maiolica up to the scaglia cinerea and bisciaro formations), display a significant lateral continuity and rather homogeneous lithofacies representative of an overall pelagic depositional environment. local occurrence of slumps and calciturbidites is fig. 3 geomorphologic sketch of the monti del furlo sector enclosing the furlo gorge and location of the areas described in the text. schema geomorfologico del settore dei monti del furlo comprendente la gola del furlo e ubicazioni delle aree descritte nel testo. 206 also noticeable (cf. alvarez & lowrie, 1984; stow et al., 1986) as a clue to topographic irregularities in the palaeo-basin floor. because of its geographical collocation as well as of the occurrence of both many good outcrops and significant facies differentiation in quite a small zone, the monti del furlo area is to be regarded as an important geologic site. many of its outcrops allow for detailed visualization and reconstruction of crucial stages of the marche apennines meso-cenozoic geologic history, from the drowning of the lower-jurassic shallow-water carbonate platform to the establishment of persisting pelagic conditions (cf. various authors, 1991; cecca et al., 1999). moreover, several fossiliferous sites as well as regional-markers outcrops (e.g. the bonarelli level or the k/t level) arouse both the scientific community and keen naturalists’ interest in the geologic heritage of this area. 3. the geomorphosites the monti del furlo area, corresponding to the northernmost sector of the marche ridge (fig. 1) anticline relief, displays such a clear morphostructural imprint (figs. 2, 5) that it can be included (togheter with petrano mt., see nesci et al., 2005) among the best examples of carbonatic anticline ridges in the central apennines. in addition, the geomorphologic interest of the area is greatly increased by an impressive transverse canyon, namely the furlo gorge. the main sectors of the ridge ( i .e . monte pietralata and monte paganuccio, fig. 2) perfectly display both the rounded geometry of the anticline and its north-west and south-east plunge-out areas. on the anticline flanks well developed homoclinal ridges and flatirons are found (figs. 2, 6). the morphostructure has developed its peculiar arrangement by different geomorphic processes, from weathering and mass movements to slope-wash and cryonivation. whatever the occurring process, selective weathering and erosion have often been able to highlight both lithologic contrasts of the jurassic-miocene “multilayer” and structural features, such as fault-zones and bended bedding surfaces. since weathering and erosion have been more effective under pleistocene cold climatic conditions, several structural landforms characterising the modern landscape of the area must be regarded as almost entirely derived from past morphogenetic stages. some peculiar landforms (i.e. broad natural amphitheatres and ricter slopes), in particular, are relics of past cold climatic conditions. others, such as those related to mass-wasting or weathering, are still more or less active, even though they can have experimented stages of more intense activity in the past. the whole area is crossed by several paths and roads, some of which can be of peculiar geomorphologic interest, since they cross both the furlo gorge and the nearby geomorphosites. as a matter of fact, they allow people to approach many significant landforms and to have panoramic views on both the monti del furlo area and on the metauro-candigliano valley and terraces. two of them match with as many geologic itineraries described by coccioni et al. (1994) and savelli & tramontana (2001): since they also cross areas of major geomorphologic interest, they are suitable for educational as well as scientific purposes and worth improving as geomorphologic paths too. a. diligenti et al. fig. 4 panoramic view of the south-western side of the monti del furlo anticline ridge showing the outcropping jurassic formations. please note the entrance of the furlo gorge and, on the foreground, the flat top-surface of the holocene terrace alluvium. veduta panoramica del fianco sud-occidentale della dorsale anticlinalica dei monti del furlo con indicate le formazioni giurassiche affioranti. si notino l’ingresso della gola del furlo e, in primo piano, la superficie pianeggiante delle alluvioni terrazzate oloceniche. 207 3.1 the furlo gorge geomorphosite the principal geomorphologic peculiarity of the area is, without any doubt, the furlo gorge, a deep canyon cross-cutting the anticline ridge (figs. 2-5 and 7-8). as a matter of fact, indications which are important for both scientific and educational standpoint definitely arise from such an attractive and scenic gorge (cf. bartolini & peccerillo, 2002). its sub-vertical walls (fig. 8), hanging over 500 m high on the present river, have been cut into the dolomitic limestones of the calcare massiccio formation by the candigliano river, the major right tributary of the metauro river. the evolution of the drainage net of the metaurocandigliano river basin started, perhaps, as long ago as in lower messinian time, but only during the upper pliocene-quaternary did the net achieve the essentials of its modern organization (cf. mayer et al., 2003). it was just at that time that the anticline ridge bypass was performed according to still largely uncertain mechanisms, which are object of a long-lasting debate and of different interpretations (e.g. mazzanti & trevisan, 1978, alvarez, 1999 and references therein). the furlo gorge devegeomorphosites in the landscape ... fig. 7 the upstream sector of the furlo gorge. veduta del tratto iniziale della gola del furlo. fig. 6 flatirons on the resistant limestones of the lower miocene bisciaro formation. north-eastern flank of pietralata mt., monti del furlo anticline ridge. flatirons modellati sui calcari della formazione del bisciaro (miocene inf.). fianco nord-orientale di m. pietralata, dorsale anticlinalica dei monti del furlo. fig. 5 panoramic view emphasizing the morphostructural arrangement of the monti del furlo anticline ridge. veduta panoramica che evidenzia l’assetto morfostrutturale della dorsale anticlinalica dei monti del furlo. fig. 8 vertical cliffs in the downstream reach of the furlo gorge. le pareti verticali del tratto iniziale della gola del furlo. 208 lops along a dominant sw-ne joint direction (mayer et al., 2003) just corresponding with a pronounced axial culmination of the anticline, as shown both by geologic data and the morphostructural arrangement itself (cf. fig. 2). moreover, a second narrow canyon (i.e. the socalled “il buzzo”) parallel to the main one cuts the external flank of the anticline ridge less than 1 km to the south-east of the furlo gorge (figs. 2, 3, 5). the unusual structural position as well as the occurrence of a second minor canyon, have recently led mayer et al. (2003) to interpret the furlo gorge as the result of capture mechanisms, rather than superposition followed by antecedence as previous authors asserted. in the geomorphosite area, the youngest (i.e. second half of the middle pleistocene-holocene) evolution stages of the valley reach enclosing the gorge, are underlined by fluvial terraces occurring on both flanks of the anticline ridge just outside the gorge (cf. fig. 3, 4, 9). in fact, several well preserved terraces and some terrace-alluvium outcrops occur close to it, reaching elevations as high as 155 m above the modern stream (nesci et al., 1990, p. 69), and highlighting the presence of four main cycles of aggradation related to as many pleistocene cold stages (cf. nesci et al., 1995 and references therein). in actual fact, both the presence of terraces and their altitudinal distribution underline a vertical uplift of the structure, but no evidence of terrace deformation relating to active thrusting and folding of the anticline can be alleged (cf. di bucci et al., 2003). besides these major subjects of scientific, educational and scenic value, both in the furlo gorge and in its vicinity the geomorphosite includes many other minor -yet noticeablelandforms and landform assemblages, which contribute to enhance the geomorphologic significance of the site. some of them are worth mentioning, as follows. small hanging valleys ending against the edge of the furlo gorge cliffs, although dried up for most part of the year, are able to produce impressive waterfalls when heavy storms and/or rapid snow-melt occur (fig. 10). narrow potholes can also be observed at the foot of the ephemeral waterfalls. such suggestive landforms due their origin to a huge difference in down-cutting rates of the candigliano river and of its small ephemeral tributaries flowing on the hard dolomitic limestones at the core of the anticline ridge. small caves (e.g. grotta del grano, i.e. “corn cave”, cf. fig. 11), tens of meters large but only a few metres deep, owing their origin to moderate karst processes associated with cryoand thermo-clastic processes, characterise the feet of the cliffs. in addition, the calcare massiccio walls of the furlo gorge bear well-developed weathering landforms both on relatively weak rock-beds and along faults. in detail, a series of weathering niches developed both along strata and along joint systems (fig. 11). in the first case, apart from a very crude bedding of the dolomitic limestones forming the gorge walls, the occurrence of weaker beds is locally underlined by a series of weathering niches arranged along curved lines which follow the bending of the anticline structure cross-cut by the gorge. in the latter case, because of poor re-cementation by carbonates, the rock has been made less resistant to weathering all a. diligenti et al. fig. 9 upper pleistocene (up) and late-middle pleistocene (mp) fluvial terraces close to the downstream termination of the furlo gorge. terrazzi del pleistocene superiore (up) e del pleistocene medio-finale (mp) in prossimità dello sbocco della gola del furlo. fig. 10 waterfalls during a stage of activity of hanging valleys inside the furlo gorge. cascata in un periodo di attività di una delle valli sospese presenti all’interno della gola del furlo. along the fractured zones, thus improving the production of niches by cryoand thermo-clastic processes associated with more or less pronounced carbonate solution. on the contrary, narrow rocky walls and ridges as well as sets of rock-spurs (figs. 12, 13) align with those major faults along which resistant fault-rocks formed because of strong calcium-carbonate cementation. outside the gorge area such fault-related landforms are lacking because of softer terrains occurrence. they are generally replaced by slopes of faultline scarps or by fault scarps exhumed by selective erosion (cf. fig. 7.2 in savelli & tramontana, 2001). anthropic modifications performed in more or less recent historical time are also noticeable, although flawlessly harmonized with the natural landscape. specifically, two roman tunnels (2nd century bc-1st century ad, cf. luni, 1993) chiselled out of rock walls of the furlo gorge characterise the canyon entrance. furthermore, a dam built up at the beginning of the 20th century has produced an attractive, narrow and deep artificial lake inside the gorge itself. 3.2 geomorphosites in the furlo gorge vicinity since the furlo gorge is not the one and only significant geomorphologic element of the area under discussion, two sites close to the gorge and valuable as geomorphosites in their own right, are worth mentioning. one of them (i.e. il buzzo) is related to the furlo gorge geomorphosite, thus contributing to highlight its scientific as well as educational significance. the other one (ca’ i fabbri) is to be considered in order to better understand how important mass movements are in shaping the anticline ridge where the gorge developed. 3.2.1 il buzzo the so called “il buzzo”, whose geomorphologic importance has just been mentioned, is a very narrow gorge running parallel to the furlo one (figs. 2, 3, 5). it consists in a close “v” shaped valley whose bottom is over-deepened by a gorge which in some places is less than two metres wide. the valley, whose head is covered by upper pleistocene stratified slope-waste deposits, is excavated in well-bedded jurassic limestones, whereas its bottom is incised in the massive limestones 209geomorphosites in the landscape ... fig. 12 fault-related rock-spur produced by weathering in the intermediate left side of the furlo gorge. sperone roccioso prodotto dalla degradazione lungo una zona di faglia, versante di sinistra della gola del furlo. fig. 11 small caves and weathering niches aligned along both bedding and fracture-systems close to the grotta del grano, intermediate sector of the furlo gorge. nicchie di degradazione lungo sistemi di fratture e superfici di stratificazione in prossimità della grotta del grano, settore intermedio della gola del furlo. fig. 13 segmented fault-related rock-wall produced by weathering on the intermediate right side of the furlo gorge. please note on the foreground the artificial lake due to damming of the gorge exit. muro di faglia parzialmente smantellato dovuto a degradazione selettiva, fianco destro della gola del furlo. si noti in primo piano l’invaso artificiale prodotto dalla costruzione di una diga all’uscita della gola. belonging (according to cecca et al., 1999) to the lower-jurassic corniola massiccia formation (cf. fig. 4). “il buzzo” valley cuts the anticline ridge extending upstream far enough beyond the axis of the structure, so that the initial valley reach falls in the internal anticline flank (cf. fig. 2). therefore, the valley head is furrowed in the south-western side of the anticline ridge, yet it does not bypass the mountain massif like the nearby furlo gorge does. the gorge is run by a minor stream, presently dry most of the year. its vertical and overhanging walls display a strong passive structural control by joint systems trending in a sw-ne direction. a particular rock bridge (fig. 14) occurs in the intermediate valley reach, where slid rock-blocks only partly reworked by stream obstruct the valley bottom to a degree. 3.2.2 ca i fabbri landslide the monti del furlo mountain ridge is a remarkable natural example of an exhumed anticline, where the geologic structure is distinctly replicated by the relief topography (cf. figs. 2, 5). although the ridge has been shaped by different processes, the role of mass movements, as in the past, is today one of the most effective (cf. fig. 3). indeed, the flanks of the anticline ridge have been extensively denudated by more or less shallow landsliding, able to highlight both lithologic contrasts and structural features, such as bended bed-surfaces. these processes are generally favoured by the occurence of weak marly/clayey-marly interbeds/units as well as by a downslope-dipping of layers prevailing on both the anticline ridge sides. additional control by intense jointing of rock units can often intervene, emphasizing the local tendency to landsliding. the ca i fabbri landslide is the best example of several large landslides which are well recognisable all over the anticline flanks (fig. 3); by the way, it is very close to the furlo and il buzzo gorges and allows for some significant panoramic views. the landslide originates on the upland flats corresponding with the anticline crest. it is a rock-slump extending c.ca 2 km downslope all over the north-eastern anticline flank. a fresh, marked arcuate cliff rimmed by tension cracks marks off the landslide head. in the upper part of the slid body, a multitude of characteristic rock-pillars alternating with trenches and counterslopes -although covered by a beech forestis so evident and distinctive to capture the attention of students as well as of common people walking along the wood paths. the slid mass becomes more and more disrupted and chaotic downslope, where its thickness (over 100 m) is appreciable because of deep gully dissection of the landslide body. moreover, the landforms freshness indicate a very recent mobilization of the upper sector of the landslide, whereas the occurrence of both deep dissection and smoothing of the sliding-related forms hints to an inactivity at the toe. acknowledgements this paper was funded by miur to o. nesci (cofinanced project “the geosites of the italian landscape: research, evaluation and enhancement”, 2001). special thanks to nicole savelli for revising the english text. references alvarez w. (1999) drainage on evolving fold-thrust belts: a study of transverse canyons in the apennines basin research, 11, 267-284. alvarez w. & lowrie w. (1984) magnetic stratigraphy applied to synsedimentary slumps, turbidites and basin analysis: the scaglia limestones at furlo, italy geol soc. am. bull., 95, pp. 324-336. bartolini c. & peccerillo a. (2002) i fattori geologici delle forme del rilievo pitagora, bologna, 216 pp. bisci c. & dramis f. (1991) la geomorfologia delle marche in: a. minetti, t. nanni, f. perilli, l. polonara & m. principi (eds.), l’ambiente fisico delle marche. geologia, geomorfologia, idrogeologia, regione marche, giunta regionale, assessorato urbanistica-ambiente, pp. 81-113. cecca f., conte g., cresta s., d'andrea m., graziano r., molinari v., pantaloni m., pichezzi r. m., rossi m., catenacci v., cacopardo m., censi neri p., pannuti v., borgia m. g., erba, menichetti m. & raffi i. (1999) risultati preliminari del rilevamento nel settore sud-occidentale del foglio n. 280 fossombrone della carta geologica d'italia a scala 210 fig. 14 the curious rock-bridge inside the “il buzzo” gorge. il singolare ponte naturale all’interno della gola de “il buzzo”. a. diligenti et al. 1:50.000 -boll. serv. geol. it., 115. coccioni r., moretti e., nesci o., savelli d., tramontana m., veneri f. & wezel f.c., with the contribution of cecca f., cresta s. & passeri l. (1994) da sansepolcro a fossombrone (km 122). assetto stratigrafico e strutturale della successione umbro-marchigiano-romagnola in: l. passeri (ed.), appennino umbro-marchigiano, 15 itinerari, guide geologiche regionali, vol 7, be-ma, milano, pp. 103-118. deiana g. & pialli g. (1994) the structural provinces of the umbro-marchean apennines mem. soc. geol. it., 48, pp. 473-484. di bucci d., mazzoli s., nesci o., savelli d., tramontana m., de donatis m. & borraccini f. (2003) active deformation in the frontal part of the northern apennines: insights from lower metauro river basin area (northern marche, italy) and adjacent adriatic off-shore journ. geodynamics, 36, pp. 213-238. luni m. (1993) la flaminia nelle gole del furlo e del burano arti grafiche editoriali srl, urbino, 67 pp. mayer l., menichetti m., nesci o. & savelli d. (2003) morphotectonic approach to the drainage analysis in the north marche region, central italy quat. intern., 101-102, pp. 157-167. mazzanti r. & trevisan l. (1978) evoluzione della rete idrografica nell’appennino centro-settentrionale geogr. fis. dinam. quat., 1, pp. 55-62. nesci o., savelli d. & mengarelli d. (1990) i terrazzi vallivi del 1° ordine nei bacini dei fiumi metauro e foglia (appennino marchigiano) geogr. fis. dinam. quat., 13, pp. 63-73. nesci o., savelli d., calderoni g., elmi c. & veneri f. (1995) le antiche piane di fondovalle nell’appennino nord-marchigiano in: g. b. castiglioni & p. r. federici (eds.), assetto fisico e problemi delle pianure italiane, mem. soc. geogr. it., 53, pp. 293-312. nesci o., savelli d., diligenti a. & marinangeli d. (2005) geomorphological sites in the northern marche (italy). examples from autochthon anticline ridges and from val marecchia allochthon il quaternario, this volume. panizza m. (2001) geomorphosites: concepts, methods and examples of geomorphological survey chinese sci. bull., 46, pp. 4-6. panizza m. & piacente s. (2003) geomorfologia culturale pitagora, bologna, 350 pp. savelli d. & tramontana m. (2001) itinerario 7. il versante sinistro della gola del furlo in: g. ciarapica & l. passeri (eds.), guide geologiche regionali, appennino umbro-marchigiano, bema (ed.), 7 (2), pp. 59-66. stow d.a.v., wezel f.c., savelli d., rainey s.c.r. & angell g. (1986) depositional model for calcilutites: scaglia rossa limestones, umbro-marchean apennines in: d.a.v. stow & d.j.w. piper (eds.), fine-grained sediments: deep-water processes and facies, blackwell publ. comp., oxford, pp. 223-243. various authors (1991) le emergenze geologiche e geomorfologiche delle marche. piano paesistico ambientale regionale industrie grafiche f.lli aniballi, ancona, 711 pp. wimbledon w.a.p. (1999) l’identificazione e la selezione dei siti geologici, una priorità per la geoconservazione in: g. poli (ed.), geositi, testimoni del tempo, edizioni pendragon, pp. 52-63. 211geomorphosites in the landscape ... sess 2_16022011_tpr3.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 high-altitude environments and glaciers fluctuations in the western sector of the aosta valley during the holocene roberta pini1*, amelia aceti1, federica badino1, valter maggi2, giuseppe orombelli2, luca raiteri3-4 & cesare ravazzi1 1c.n.r., istituto per la dinamica dei processi ambientali, milano 2disat, università di milano – bicocca 3regione autonoma valle d’aosta, soprintendenza beni e attività culturali, aosta 4dip. biologia ed evoluzione, università di ferrara *corresponding author: r. pini <roberta.pini@idpa.cnr.it> abstract: pini r. et al., high-altitude environments and glaciers fluctuations in the western sector of the aosta valley during the holocene (it issn 0394-3356, 2011) palaeobotanical and chronological data from high-altitude mire successions in the western alps (aosta valley) are here compared with geomorphological evidences of glacier oscillations, to describe the history of glacial systems and the occurrence of phases of climatic optimum during the first half of the holocene. these phases are marked by periods of glacier recession, rise of the forest limit up to altitudes above 2400 m and widespread tufa deposition at 2000 m altitude. these data are in good agreement with available information from the central italian, the swiss and the austrian alps. riassunto: r. pini et al., ambienti d’alta quota e oscillazioni glaciali nel settore occidentale della valle d’aosta durante l’olocene (it issn 0394-3356, 2011) l’analisi integrata di dati paleobotanici e cronologici da successioni di torbiera d’alta quota nel settore occidentale della valle d’aosta e di evidenze geomorfologiche in aree interessate da avanzate glaciali oloceniche fornisce indicazioni sulla storia degli apparati glaciali e sull’esistenza di più fasi di optimum climatico durante la prima metà dell’olocene. queste fasi sono testimoniate da periodi di evidente recessione glaciale, innalzamento del limite delle foreste a quote superiori ai 2400 m e alla deposizione diffusa di travertini a 2000 m di quota. i dati ottenuti sono in accordo con quanto noto per le alpi centrali italiane, le alpi svizzere e austriache. key words: holocene, aosta valley, mires, glaciers, tufa, prehistoric archaeology parole chiave: olocene, valle d’aosta, torbiere, ghiacciai, travertini, archeologia preistorica among the stratigraphical archives yielding information on the structure of ancient natural and anthropic landscapes, mires are of particular interest. these habitats, widespread on the alpine chain, develop well on crystalline bedrock along wide altitudinal transects, extending from the colline to the high-alpine belt. detailed geological and geomorphological surveys in former glacialized areas nowadays occupied by mires provide interesting data on past glacier extent and fluctuations and help reconciling the chronology of local glacial history, trees immigration and forest development. this contribution focuses on recent investigations carried out by the authors on high-altitude mires and glacial systems in the western sector of the aosta valley. relevant sites are: the foreland of the rutor glacier (2510 m asl, la thuile valley: fig. 1). here a succession of compressed peat, 14c dated to 7600 – 9200 cal years bp and intercalated within minerogenic deposits, outcrops along the proglacial stream and provides information on former phases of glacial recession during the first half of the holocene and on the history of vegetation development, both at local and regional scale (orombelli, 1998; aceti, 2006); the crotte basse mire (2365 m asl, southern slope of mont fallére, aosta: fig. 2). this stratigraphical sequence was cored in summer 2009 and 2010, retrieving multiple cores along the succession of lacustrine – palustrine deposits. pollen and geochemical analysis and 14c determinations are still in progress: available data testify to an early stage of vegetation development (before the holocene onset) and the subsequent expansion of forests growing well above their present day altitudinal ranges. this forest displacement interacted with mesolithic hunters and gatherers and eneolithic farmers seasonally settling on nearby high-altitude areas for subsistence purposes (guerreschi et al., 2010). a 4m thick tufa bank, outcropping at 1950 m asl on mont fallére. this deposit, rich in wood, charcoal, needles and cone imprints, testifies to the local development of pinus sylvestris woodlands during the holocene climatic optimum 117 119 118 fig. 1, panoramic view of the western and central lobes of the rutor glacier. the white line indicates the position of the moraine related to the 1980’s advance; an arrow shows the outcrop of compressed peat discussed in the text (photo: amelia aceti, summer 2005). panorama dei lobi occidentale e centrale del ghiacciaio del rutor. la linea bianca indica la posizione della morena deposta dopo l’avanzata degli anni ’80; la freccia mostra la posizione dell’affioramento di torbe compresse discusse nel testo (foto: amelia aceti, estate 2005).  fig. 2, the crotte basse mire: this stratigraphic sequence provides information for the reconstruction of the vegetation and climate history of the area from the last part of the late glacial to the present (photo: diego de nisi, summer 2009). la torbiera delle crotte basse: questa sequenza stratigrafica illustra la storia della vegetazione e del clima dell’area in esame a partire dalla fine del tardoglaciale fino ai giorni nostri (foto: diego de nisi, estate 2009). r. pini et al. 119 ms. received: testo ricevuto il and allows for comparisons with the palaeobotanical information obtained from the crotte basse mire. interestingly, this is not the only tufa deposit found on mont fallére: the slopes actually host several tufa layers, displaying massive to porous texture and varying in thickness from a few centimeters to several decimeters. discussion the stratigraphic section at the foreland of the rutor glacier testifies to prolonged phases of glacier recession framed between the early and the middle holocene. deposition of fine-grained material (lacustrine silt overlied by peat) above glacial sediments can be related to a phase of sudden glacier retreat dated to ca. 9500 years cal bp. the glacier maintained a reduced extent at least up to ca. 6500 years cal bp, possibly up to 4900 years cal bp (considering the age of other peat layers found dislocated nearby the studied section). forests never reached the proglacial rutor area; palaeobotanical data indeed suggest that abies alba was widespread along the valley slopes possibly up to an altitude of ca. 2000 – 2200 m asl, while pinus cembra developed at higher altitudes. the same chronological interval is testified at the crotte basse mire. palaeobotanical and chronological data indicate the local occurrence of dense conifer forests dominated by pinus cembra as early as ca. 8800 years cal bp, accompanied by abies alba starting at ca. 8600 years cal bp. the full sun aspect enabled the growth of dense conifer forests up to an exceptional altitude (at least up to 2365 m asl). the widespread deposition of tufa at an unusual altitude (1900 2150 m asl) on mont fallére may represent an evidence for phases of climatic optimum. in particular, radiocarbon dating of the huge carbonatic bank found on the southern mountain slope established that tufa accumulated quickly between 5800 – 9100 years cal bp. generally speaking, glaciological and palaeobotanical data from the western alps are in good agreement with those from the central italian, the swiss (hormes et al., 2001) and the austrian alps (nicolussi & patzelt, 2000) and speak for several phases of climatic optimum during the first half of the holocene, characterized by recessional glacier phases and development of woody vegetation well above the modern treeline. further studies are needed to understanding and characterize such phases and for a better definition of their timing and extent: are they short-lived, centennial phases or longer periods of climatic optimum? references aceti a. (2006) – la variabilità climatica nell’olocene: studio di torbiere e ambienti d’alta quota nelle alpi italiane. unpublished phd thesis in geological sciences, univ. milano – bicocca, 115 guerreschi a., raiteri l., di maio p., ravazzi c., pini r., gabriele p. & baster i. (2010) – a new high-altitude mesolithic site on mont fallére (aosta, northern italy). first results on archaeology, environmental and landscape evolution. convegno meso 2010 – the 8th international conference on mesolithic in europe (santander, spain). abstract volume. hormes a., müller b.u. & schlüchter c. (2001) – the alps with little ice: evidence for eight holocene phases of reduced glacier extent in the central swiss alps. the holocene, 11, 255-265. nicolussi k. & patzelt g. (2000) – discovery of early holocene wood and peat on the forefield of the pasterze glacier, eastern alps, austria. the holocene, 10, 191-199. orombelli g. (1998) – le torbe del rutor: una successione significativa per la storia olocenica dei ghiacciai e del clima nelle alpi. mem. soc. geogr. it., 55, 153-165. january 14, 2011 14 gennaio 2011 high-altitude environments and glaciers fluctuations ... imp.castaldini& geo-tourist map of the natural reserve of salse di nirano (modena apennines, northern italy) doriano castaldini1, jairo valdati1, dorina camelia ilies2 & cosmin chiriac2 with contributions by isabella bertogna3 1dipartimento di scienze della terra, università di modena e reggio emilia, modena, largo s. eufemia 19, modena, italy; e-mail: castaldini.doriano@unimore.it 2department of geography, tourism and territorial planning, university of oradea, armata romana 5, oradea, romania. 3riserva naturale regionale delle salse di nirano, comune di fiorano modenese, piazza c. menotti 1, fiorano modenese, italy. abstract: d. castaldini et al., geo-tourist map of the natural reserve of salse di nirano (modena apennines, northern italy). (it issn 0394-3356, 2005). this article illustrates the criteria and methods applied for implementing a geo-tourist map of the natural reserve of “salse di nirano”. this map is an “original” cartographic elaboration in the field of italian thematic mapping. the “salse” are small mud volcanoes genetically linked to the ascent to the surface of salty and muddy waters mixed with gaseous (methane) and, to a lesser extent, fluid hydrocarbons along tectonic discontinuities produced by overthrusting along the front of the apennine chain. the mud volcanoes of the modena apennines have been known since a long time and have always aroused great interest: they are described in many papers, starting as early as pliny the elder, in around 50 a.d. since the “salse di nirano” are one of the best developed mud-volcano phenomena of the entire italian territory and among the largest in europe, in 1982 a natural reserve was established in the area by the emilia-romagna region; the reserve territory covers a total area of about 200 ha with elevations ranging from 140 to 308 m. by means of arcview gis computer program a digital terrain model (dtm), a geomorphologic map and a geo-tourist map have been elaborated and will be displayed at the visitor center of the reserve. the orographic arrangement of the territory is effectively illustrated by dtm, which was implemented on the basis of altimetric data of the regional technical map (ctr) of the emiliaromagna region. the detailed geomorphologic features are represented in a geomorphologic map, elaborated on the basis of bibliographic research, interpretation of aerial photographs and field survey. in the study area, where silty-clay soil types (plio-pleistocene in age) crop out, landforms and deposits resulting from the endogenetic activity of the mud volcanoes, running water, gravity, anthropogenic activities and polygenetic landforms were recognized. the geo-tourist map was derived (with appropriate simplifications and integration) from the geomorphologic map. the geo-tourist map combines the most evident geomorphologic features (mud volcanoes, badlands, landslides, anthropogenetic landforms, bedrock, surface deposits, ponds, marshes etc.) – which can be observed and recognized even by non-experts – with fundamental tourist information (main roads, parking places, visitor center, excursion trails, picnic areas, panoramic points, restaurants and places to stay). the geo-tourist map and dtm are the characterizing documents of a new tourist map of the reserve (tourist-environmental map). in particular, the geo-tourist map is a foldable, pocket-size, front/rear printed map, with explanatory notes in italian and english: it was published with the financial support of the municipality of fiorano modenese. this article proves that geomorphologic research can effectively contribute to the implementation of documents and maps useful in the field of tourism. riassunto: d. castaldini et al., carta geo-turistica della riserva naturale delle salse di nirano (appennino modenese, nord italia). (it issn 0394-3356, 2005). il presente articolo illustra i criteri e la metodologia applicati per la realizzazione della carta geo-turistica della riserva naturale regionale delle salse di nirano, che rappresenta un documento “originale” nella panoramica della cartografia tematica italiana. le “salse” sono dei piccoli vulcani di fango geneticamente connessi a risalita in superficie di acqua salata e fangosa frammista ad idrocarburi principalmente gassosi (metano) e, in piccola parte, liquidi (petrolio), lungo discontinuità prodotte dagli accavallamenti frontali dell’appennino. le salse dell’appennino modenese sono note da molto tempo ed hanno da sempre suscitato grande interesse: sono state descritte in numerosissimi lavori, già a partire da plinio il vecchio nel 50 d.c. essendo il campo delle salse di nirano, uno dei fenomeni seudo-vulcanici meglio sviluppati su tutto il territorio italiano e tra i maggiori d'europa, la regione emilia-romagna nel 1982 vi ha istituito una riserva naturale che occupa una superficie totale di circa 200 ha ed è compresa fra i 140 e i 308 m di quota. per facilitare al visitatore la lettura e la comprensione del paesaggio della riserva sono stati elaborati, utilizzando il sistema informativo territoriale arcview, un modello digitale del terreno (dtm), una carta geomorfologica e una carta geo-turistica che saranno esposti al centro visite della riserva. l’assetto orografico del territorio è efficacemente reso dal dtm, realizzato sulla base dei dati altimetrici della carta tecnica regionale (ctr) della regione emilia romagna. gli aspetti geomorfologici di dettaglio sono rappresentati in una carta geomorfologica, realizzata sulla base di una ricerca bibliografica preliminare, dell’interpretazione di fotografie aeree e mediante rilevamenti sul terreno. nell’area di studio, dove affiorano esclusivamente litologie limo-argillose (del plio-pleistocene), sono state riconosciute forme e depositi legati al fenomeno “endogeno” delle salse, per acque correnti superficiali, gravitativi di versante, antropici e poligenetici. la carta geo-turistica è stata derivata (con appropriate semplificazioni ed integrazioni) dalla carta geomorfologica. la carta geo-turistica coniuga la rappresentazione dei più evidenti aspetti geomorfologici (salse, calanchi, frane, opere antropiche, litologia del substrato e depositi superficiali, specchi d’acqua, paludi ecc.), che possono essere osservati e riconosciuti anche da persone non esperte, con l’indicazione delle informazioni turistiche fondamentali (punti di accesso, parcheggi, centro visite, percorsi escursionistici, aree di sosta attrezzate, punti panoramici, punti di ristoro e di pernottamento). la carta geo-turistica e il dtm sono i documenti caratterizzanti di un nuovo depliant turistico della riserva (carta turistico-ambientale). questo nuovo documento è un pieghevole, di formato tascabile, stampato fronte/retro con note illustrative in italiano e in inglese: è stato stampato con il contributo finanziario del comune di fiorano modenese il presente articolo testimonia come la ricerca geomorfologica possa efficacemente contribuire alla realizzazione di documenti utilizzabili nel settore turistico. keywords: mud volcanoes, geomorphology, geo-tourist map, modena apennines, northern italy. parole chiave: salse, geomorfologia, carta geo-turistica, appennino modenese, italia settentrionale. il quaternario italian journal of quaternary sciences 18(1), 2005 volume speciale, 245-255 246 d. castaldini et al. 1. foreword in the past few years several studies have been carried out both at an international (e.g., wimbledon et al., 1995; dixon, 1996; eberhard, 1997; hose, 1997; barrettino et al., 1999; johansson & zarlenga, 1999; coratza & marchetti, 2002; reynard et al., 2003) and national (e.g. carton et al., 1994; benvenuti et al., 1998; bertacchini et al., 1999; panizza, 2001; poli, 1999; piacente et al., 2000; piacente & poli, 2003) level for the preservation of geologic heritage (whose elements are defined, according to the various authors, as “geologic assets”, “geotopes”, “geosites” or “geomorphosites”) and its diffusion and appraisal also outside the realms of academic research. for a general discussion on this topic, see panizza & piacente (2003). this paper is about the “salse di nirano” geosite, which makes up the only endogenetic forms found in the modena apennines. from a general viewpoint, mud volcanoes are remarkable geologic features formed by semi-liquid and gas-enriched mud breccias extruded from deep sediment layers on the ground surface or on seafloors (cf. dimitrov, 2002 and references in it; deville & prinzhofer, 2003). mud volcanoes are known in many areas of the world; the most important ones are located in azerbaijan, mexico, venezuela, colombia, and ecuador. in europe they can be found in italy, albania and romania. although most mud volcanoes have a typical conical shape, they can assume a great variety of forms, referred to as “mud cones”, “mud lumps”, “mud diapirs”, “mud pies” etc., depending on their shape and size which, in turn, depend on the degree of mobilization initiated by pore-fluid pressures, frequency and characteristics of their activity, and viscosity of the outflowing mud. for example, the azerbaijan mud volcanoes attain a height of some 500 m. also the mud volcanoes of the modena apennines are genetically linked to the ascent to the surface of salty and muddy waters mixed with hydrocarbons along tectonic discontinuities produced by the overthrusting of the apennine chain front (illustrated in the geologic section). the name “salsa” results from the high “salt” content of these muddy waters. the shape of the ejection apparatus depends on the density of the muddy mixture: if it is dense, “cones” (single, double or multiple) of height ranging from a few decimeters to some meters may develop; if the muddy mixture is liquid, ground level “pond-shaped” mud-volcanoes (diameters ranging from a few decimeters to some meters) are formed. the mud volcanoes of the modena apennines have been known for a long time and have always aroused great interest. they were first described by pliny the elder, in around a.d. 50, in his monumental “naturalis historia”. pliny the elder described the eruption of a mud volcano in the modena district (but it is not known to which one he referred) with the much exaggerated terms of “crepitu maximo… flamma fumoque”. other scientists after him, especially in the 17th and 19th centuries, described the mud-volcano activity with the same fantastic attributes of impressiveness and spectacularity (e.g. ramazzini, 1698; spallanzani, 1795). in particular, at the end of the 19th century the abbot stoppani described the “salse di nirano” comparing them to molehills out of which noises similar to “retching” came out; he gives them the epithet of “cesspool volcanoes” (stoppani, 1873). many other authors followed (e.g. pantanelli & santi, 1896; biasutti, 1907; barbieri, 1947; mucchi, 1966 and 1968; bertolani, 1980; ferrari & vianello, 1985; bertacchini et al., 1999; castaldini et al. 2003; gorgoni, 1998 and 2003). mud volcanoes are a classical example of “geomorphologic convergence”, that is, similar forms but with different origins (panizza, 1992). in fact, although cone-shaped cones and flows are being formed and, in the specific case of salse di nirano, a caldera-like depression contains all these emissions, mud volcanoes have nothing to do with actual volcanism, although many visitors still think they have. the “salse di nirano” are one of the best developed mud-volcano phenomena of the entire italian territory and among the largest in europe. in 1982, the natural reserve of salse di nirano was established in the area by the emilia-romagna region, with the aim of safeguarding and preserving the natural and environmental characteristics of the site (tosatti, 2002). in this way, the fruition of the area for scientific, cultural, educational and recreational purposes was be attained. within the framework of investigations for assessing and appraising geosites in the italian landscape, and in collaboration with the board administering the reserve (municipality of fiorano modenese), a digital terrain model (dtm), a geomorphologic map and a geo-tourist map have been elaborated and will be displayed at the visitor center of the natural reserve of salse di nirano (named “ca’ tassi”). these should help to explain the landscape of the reserve to tourists. in particular, this article illustrates the criteria and methodology applied for implementing a geo-tourist map which combines the illustration of the most significant geologic-geomorphologic aspects with fundamental tourist information. 2. geographic and geologic outline of the study area the natural reserve of salse di nirano is located in the western sector of the modena apennine margin, which belongs to the northern apennines (fig. 1). the territory of the natural reserve covers a total area of about 200 ha with elevations ranging from 140 and 308 m a.s.l. the area where the mud volcanoes are found covers about 10 ha and is situated at the bottom of a wide subcircular depression at an altitude of about 200 m. the setting up of new structures – such as a large parking lot, a new footpath leading to the mud-volcano fields, some resting areas and a road leading to the ca’ tassi visitor center – have facilitated the fruition of the reserve, which was visited by 30,000 people in the year 2003. this influx of visitors also shows that this “small green belt” of the lower modena apennines is in a strategic position from the tourist viewpoint. as for climate, the study area is comprised within the sub-continental temperate climate with average precipitation of about 800 mm/year and average temperatures of 12 to 13 °c (see servizio meteorologico della regione emilia-romagna, 1995). 247geo-tourist map of ... from a geologic standpoint, the modena apennine margin is characterized by prevalently compressive structures which correspond to the so called “emilia folds” (pieri & groppi, 1981; castellarin et al., 1985; gasperi et al., 1989). tectonic structures have been produced by northbound translational movements (occurring mainly during the messinian and pliocene) which affected both the apennine chain and the plain which lies in front of it. these movements led to the sequence of thrusting and décollement structures and controlled to some extent the sedimentation rate in the plain (fig. 2). sediments ranging from the lower pliocene to the lower pleistocene outcrop almost continuously in this area. to the south, these deposits are usually transgressive on the ligurian units (made up of deepsea sediments followed by thick sequences of cretaceous to eocene calcareous or terrigenous turbidites); to the north, towards the po plain, they are covered by alluvial deposits of the middleupper pleistocene. in the apennine margin many faults and folds affecting the marine quaternary sediments, indicate a middle pleistocene uplift of the apennine sector with respect to the plain and a tendency of the southern structures to overthrust the northern structures (castaldini et al., 1988). the present day tectonic activity of the apennine margin is shown by earthquakes that, in this area, are mostly concentrated along the plain-hil l boundary. among the most intense seismic events, the quakes of 1438 (viii mcs), 1501 (viii-ix), 1547 (viii), 1818 (vii-viii ) , 1971 (vii-viii ) should be mentioned (cf. gruppo di lavoro cpti, 1999). in the past, some authors noted a correspondence between episodes of violent activity of the mud volcanoes and earthquakes (cf. stohr, 1869; pantanelli & santi, 1896; pellegrini et al., 1982; gorgoni et al., 1988). more recent investigations (gorgoni, 1998 and 2003) have shown that the activity of the mud volcanoes is influenced by local seismicity, some days before the occurrence of rather strong earthquakes. fig. 1 upper part: location of the natural reserve of salse di nirano (point) and of the geologic cross section of fig. 2 (line). lower part: the natural reserve of salse di nirano in the regional technical map (ctr) of the emilia-romagna region (tav. 219 no sassuolo). parte superiore: ubicazione della riserva naturale delle salse di nirano (punto) e del profilo geologico di fig. 2 (linea). parte inferiore: la riserva naturale delle salse di nirano nella carta tecnica regionale (ctr) della regione emilia-romagna (tav. 219 no sassuolo). 248 3. geomorphologic features of the natural reserve in order to offer detailed information about the physical landscape of the reserve area, a geomorphologic map and a digital terrain model (dtm) have been realized by means of arcview gis computer program. the topographic basis for their elaboration was the regional technical map (ctr) of the emilia-romagna region (1:5,000 scale) (fig. 3). the general morphologic picture of this territory is effectively provided by the dtm (fig. 4) which was computer-elaborated through the transformation of altimetric data (5 m equidistance contour l ines) into a triangular irregular network (tin). by examining it, the presence of a sub-circular shaped depression, similar to a caldera, is quite evident even to nonexperts: on the floor of this depression the mud volcanoes are found. an explanation is that this form is the result of a progressive gravitational collapse due to the constant depletion of mud ejected from the vents (bertacchini et al., 1999). another hypothesis is that the depression could be the result of a collapse in correspondence of a “mud-diapir” at the end of its uplifting activity (personal communication by g. bettelli). indeed, this hypothesis seems to be more plausible, because it explains not only the depression itself, but also its sub-circular shape. also the “calanchi” (badlands) are quite evident in the dtm. these are one of the most spectacular forms of erosion, similar to badlands, of the apennine margin (fig. 5). they are typical of clayey soils and are characterized by a very fine drainage network and short, steep slopes with narrow interfluves. the dtm clearly shows that these landforms are absent only in the southern part of the reserve. furthermore, the excursion trails have been indicated in order to provide the visitor with information on their elevation development. d. castaldini et al. fig. 2 geologic cross section of the modena apennine margin and plain (after gasperi et al., 1989). q: quaternary; plms: upper-middle pliocene; pli: lower pliocene ms: upper miocene; mm: middle miocene; mi: lower miocene; l: ligurian units. profilo geologico del margine appenninico e dell’alta pianura modenese (da gasperi et al., 1989). q: quaternario; plms: pliocene medio-superiore; pli: pliocene inferiore; ms: miocene superiore; mm: miocene medio; mi: miocene inferiore; l: liguridi. fig. 3 scheme of elaboration of the various documents. schema di elaborazione dei vari documenti. fig. 4 digital terrain model (dtm) of the natural reserve of salse di nirano (modena apennines). modello digitale del terreno (dtm) della riserva naturale delle salse di nirano (appennino modenese). 249 detailed morphologic aspects are illustrated in a geomorphologic map, resulting from bibliographic research, analysis of recent aerial photographs (1994 and 1998/99) and field survey. in drawing up the geomorphologic map of the study area (fig. 6) the legend set up by gruppo nazionale geografia fisica e geomorfologia (1994) was applied with some modifications. in the reserve area only silty-clay soil types (pliopleistocene in age) crop out: the “argille del t. tiepido” (marine silty-clays) which are found nearly all over the territory and the “argille del rio del petrolio” (marine marly-clays) cropping out to the north. the study area is characterized by the presence of two systems of tectonic discontinuities (faults and/or fractures), nw-se and sw-ne oriented, respectively. these discontinuities have been identified by means of aerial photo interpretation and field observations of the mud volcanoes arrangement, which shows a clear alignment (fig. 7). the main streams are the rio chianca (which marks the western and northern boundary of the park), rio delle salse and its tributary rio serra which, as previously stated, flow in the southern sector of the reserve. in addition, some small reservoirs are also found: three ponds and four marshy areas. another four relict ponds have been completely filled by palustrine deposits. their origin is artificial as witnessed by the presence of artificial embankments downstream. the geomorphologic map (fig. 6) does not show the precise number of the mud-ejecting points but simply their location, distinguishing between cone-shaped mud volcanoes (fig. 7) and pond-shaped mud volcanoes (fig. 8). the morphology of this area is, in fact, constantly evolving with the formation of new craters whilst others cease their activity. the activity of a salsa is influenced by meteorologic factors. in summer, the activity may decrease due to the muds’ de-hydration until the possible obstruction of the up-welling channel occurs. during wetter seasons, due to the terrain softening and to the increasing methane’s pressure accumulating deeper down, the obstruction can be demolished and the activity may restart. during non-active periods, the mud volcanoes are subject to erosion by precipitation water and can be partially dismantled, until the following activity phases when they are rebuilt. the number of apparatuses can vary with time, as well as their location: in the case of nirano, the mapping and photographic documents point to a considerable steadfastness during the past one hundred years (gorgoni, 2003). during our survey, five main groups of cone-shaped mud volcanoes and three main groups of pondshaped ones were found. the clayey materials ejected from the craters cover the surrounding ground with mudflows. therefore, owing to the constant emission of mud over time, the floor of this depression is covered by fine-grained deposits up to a few meters in thickness. the main anthropogenetic landforms are found near the eastern entrance to the reserve. they are: i) an abandoned quarrying area, modeled at present by the running waters which have created the badlands, gullies and colluvial deposits; ii) a parking area for visitors and iii) an artificially flattened area corresponding to a disused farming area (a worm “farm” for anglers). furthermore, the areas affected by creep due to grazing, which are concentrated on the northern slopes of the reserve, are also shown. this man-induced process is made evident by the step-like shape of the slopes created by pasturing sheep. by reducing the grass cover of the soil, these animals have also favored the onset of solifluction. the numerous crests and watersheds have been considered as polygenetic forms. indeed, while the sub-circular crest which surrounds the mud-volcano depression is probably linked to a gravitational collapse, other watersheds were created by retrogradation of the badland heads. the landforms and deposits due to running waters are particularly widespread. nearly everywhere it is possible to observe badlands (“calanchi”) in most cases stabilized by vegetation. small earth flows, in most cases stabilized, fill the erosion furrows at the foot of the badlands; they too are shown on the geomorphologic map. also the main gullies are indicated. deposits have been indicated only where their thickness exceeds 1 m. they are mostly made up of very fine materials deposited by the main watercourses (concentrated on the floor of the small valleys of rio chianca, rio serra and rio delle salse) and colluvial deposits (particularly widespread at the foot of the northern slope of the mud volcanoes depression). geo-tourist map of ... fig. 5 the “calanchi” (badlands) of the rio chianca valley in the northern sector of the reserve. i calanchi della valle del rio chianca nel settore settentrionale della riserva. 250 d. castaldini et al. fi g. 6 g eo m or p ho lo gi c m ap o f t he n at ur al r es er ve o f s al se d i n ira no (m od en a a p en ni ne s) . c ar ta g eo m or fo lo gi ca d el la r is er va n at ur al e d el le s al se d i n ira no (a p p en ni no m od en es e) . landslide bodies and relative detachment scarps are quite common all over the reserve; they are landslides classified as small earth flows. most landslide deposits have been colonized by spontaneous vegetation which has contributed to stabilizing them and making them poorly visible in the field. solifluction makes up a secondary process particularly widespread in the northern part of the reserve, where it has been favored by creep due to grazing. 4. geo-tourist map a geo-tourist map can be considered as a thematic map; these are maps which focus on a particular aspect (cf. sestini, 1981; mori, 1990) and, consequently, are aimed at specific categories of users. first of all, in the preparation of a thematic map, the set of data that are to be emphasized must be chosen, namely the setting up of a language and mapping system (cf. papotti, 2002). therefore, a geo-tourist map should combine geologicgeomorphologic data with tourism data. the geo-tourist map here il lustrated was derived (with appropriate simplifications and integration) from the geomorphologic map and combines the most evident geologic-geomorphologic aspects with basic tourist information (fig. 3). the geo-tourist map, which was originally produced in color, is here presented in black and white (fig. 9). the goal of this study was to make a map which could be easy to read for a tourist of average education. since the immediacy of a map depends essentially on the simplicity of the symbols used, we deliberately avoided the setting up of a legend finalized to the completeness of data, which would have implied a long list of symbols. considering that the more symbols are added the more is lost in clarity, the use of symbols was limited to the essential ones. in particular, the legend was subdivided into two clearly distinct sectors. in the first sector the symbols representing geologic and geomorphologic aspects are illustrated, whereas in the second one the symbols concerning tourism information are shown. regarding the geomorphologic aspects, the geo-tourist map pinpoints all the elements of the landscape that a tourist can observe and identify. an effort was made to use simple, clear, graphically pleasing symbols with short captions, avoiding specialized terminology. in any case, the legend adopted is scientifically correct. from the practical viewpoint, using the geomorphologic map as a starting point, the following criteria of elaboration have been applied: i) as regards the mud 251geo-tourist map of ... fig. 8 pond-shaped mud volcano. salsa a “polla”. fig. 7 cone-shaped mud volcanoes. they show a clear alignment in corrispondence with a fault/fracture. salse “a cono”. esse sono chiaramente allineate lungo una faglia/frattura. 252 d. castaldini et al. fi g. 9 g eo -t ou ris t m ap o f t he n at ur al r es er ve o f s al se d i n ira no (m od en a a p en ni ne s) . c ar ta g eo tu ris tic a d el la r is er va n at ur al e d el le s al se d i n ira no (a p p en ni no m od en es e) . volcanoes (“salse”) – the main attraction of the reserve – symbols graphically recalling both the “cone-shaped” forms and the “pond-shaped” ones have been adopted; ii) these symbols are shown in particularly evident dimensions, so that the tourist can immediately locate them; iii) the distinction of activity for landforms and deposits has been eliminated; iv) also faults/fractures have been cancelled from the map since they are not easily identifiable in the field; v) the less representative forms (e.g., gullies) and the most difficult ones to be recognized (e.g., slopes affected by solifluction, areas affected by creep due to grazing) have been eliminated; vi) the various types of deposits have been simplified (e.g., a single grouping for deposits due to running waters); vii) in the original version (in color) the range of colors used has been reduced. as for tourist information, in the original version (in color) this has been indicated with a particularly evident color (red), in order to be immediately recognized by the visitors. the commonly used symbols for tourist maps have also been adopted in this case. they include: i) general information (e.g., ca’ tassi visitor center, excursion trails, panoramic points along the excursion trails, picnic areas); ii) wildlife information (bird-watching points); iii) logistic information (main access roads, parking places, refreshment and overnight-stay sites, consisting of a restaurant, a holiday farm and a bed & breakfast). as previously stated, in the geo-tourist map (and in the dtm) the excursion trails are shown in order to facilitate the interpretation of the landscape and its elevation points for the tourist willing to walk along the trails suggested. the trails are as follows: 1) tour of the “salse”: this trail winds around the core of the natural reserve allowing the phenomenon of mud volcanoes to be observed from both close up and from a panoramic viewpoint. 2) walk around the ponds: this trail follows the valley floor of the rio delle salse/rio serra as far as the two artificial ponds se of pra’ rosso (where birdwatching can be practiced), then it continues upwards as far as the southernmost crest of the reserve. 3) walk from the salse depression to the chianca valley: this comprises some panoramic points from which the view of the entire mud volcanoes depression can be appreciated. along this trail it is possible to observe at close quarters the western “calanchi” of the reserve and a typical example of marsh. 4) tour of the “calanchi”: this trail follows prevalently the valley floor of rio chianca and allows the observation of several examples of badlands from below. 5. conclusions the study here described was finalized to the implementation of a digital terrain model (dtm), a geomorphologic map and a geo-tourist map of the natural reserve of salse di nirano. whereas the first two documents are common within the framework of geomorphologic studies, the geo-tourist map is an original document. the goal was to produce a map that could be easily interpreted by tourists with average education and help them to understand the surrounding landscape. therefore, since the readability of a map depends essentially on the simplicity of its symbols, only the symbols considered as essential are shown. in particular, the legend was subdivided into two clearly distinct sectors. the first sector shows the symbols representing the geologic and geomorphologic aspects, whereas the second shows the symbols regarding tourist information. all maps (geomorphologic map, dtm and geotourist map) have been implemented by means of arcview gis computer program. therefore, since these documents are presented in the digital format, they can be easily updated and/or integrated with further data. the dtm and geo-tourist map are the characterizing documents of a new tourist foldable on the reserve (tourist-environmental map). the elaboration of the foldable, pocket-size, front/rear printed touristenvironmental map has now been completed. this document, which is presented with explanatory notes in italian and english, was published with the financial support of the municipality of fiorano modenese (barozzini et al., 2004). this initiative, which is part of the activities aiming to improve the information, fruition and appraisal of the region’s natural reserve of salse di nirano, witnesses how geomorphologic investigations can effectively contribute to the creation of maps utilizable in the tourism field. acknowledgements the financial support of this study was provided by cofin 2001-03 research project (coordinator sandra piacente, dipartimento di scienze della terra dell’università di modena e reggio emilia). the authors are grateful to professors mario panizza, sandra piacente and maurizio pellegrini and to doctors paola coratza and cecilia giusti, for their critical review of the preliminary version of the geo-tourist map. references barbieri g. (1947) nuove osservazioni sulle salse emiliane riv. geogr. it., 54 pp. barozzini e., bertogna i., castaldini d., dallai d., del prete c., chiriac c., gorgoni c., ilies d.c., sala l. & valdati j. (2004) riserva naturale regionale delle salse di nirano”: carta turistico ambientale comune di fiorano-assessorato ambiente. eliofototecnica barbieri, parma. barrettino d., vallejo m. & gallego e. (eds.) (1999) towards the balanced management of geological heritage in the new millenium sociedad geologica de españa, madrid, 146 pp. benvenuti m., boni m., brancucci g., bortolami g., burlando m., costantini e., d’andrea m., gisotti g., guado g., marchetti m., massoli-novelli r., panizza m., pavia g., poli g. & zarlenga f. (1998) the conservation of geological heritage in italy: state of the art and future perspectives of the “geosites” project geologica balcanica, 28(34), pp. 117-123. bertacchini m., giusti c., marchetti m., panizza m. & pellegrini m. (eds.) (1999) i beni geologici della 253geo-tourist map of ... provincia di modena artioli ed., modena, 104 pp. bertolani m. (1980) fiorano e il suo territorio docum. e ric. comune di fiorano modenese, pp. 1-24. biasutti r. (1907) le salse dell’appennino settentrionale mem. geogr. 2, pubbl. suppl. riv. geogr. it. carton a., cavallin a., francavilla f., mantovani f., panizza m., pellegrini g.b., tellini c., con la collaborazione di bini a., castaldini d., giorgi g., floris b., marchetti m., soldati m., surian n.(1994) ricerche ambientali per l’individuazione e la valutazione dei beni geomorfologici. metodi ed esempi il quaternario, 7(1), pp. 365-372. castaldini d., chiriac c., ilies d.c. con la collaborazione di barozzini e. (2003) documenti digitali per la conoscenza integrata dei geositi: l’esempio della riserva naturale delle salse di nirano – in: s. piacente & g. poli (eds.), la memoria della terra. la terra della memoria, regione emilia romagna. ed. l’inchiostroblu. bologna, pp. 121-127. castaldini d., moretti s. & rodolfi g. (eds.) (1988) guidebook for the excursion in the toscana, emilia and veneto regions proc. i.g.u. joint meeting on geomorphological hazards. 28/5 4/6/1988, firenze-modena-padova (italy), 151 pp. castellarin a., eva c., giglia g. & vai g.b. con un contributo di rabbi e., pini g.a. & crestana g. (1985) analisi strutturale del fronte appenninico padano giornale di geologia, 47/1-2, pp. 47-75 coratza p. & marchetti m. (eds.) (2002) "geomorphological sites: research, assessment and improvement” proceedings of the workshop held in modena, italy, on june 19-22, 2002 legoprint, lavis (trento), 110 pp. deville e. & prinzhofer a. (2003) vulcani di fango le scienze (italian version of scientific american), 421, pp. 84-90. dimitrov l.i. (2002) mud volcanoes – the most important pathway for degassing deeply buried sediments earth-science reviews, 59, pp. 49-76. dixon g. (1996) geoconservation: an international review and strategy for tasmania parks & wildlife service, occasional paper no. 35, 126 pp. eberhard r. (ed.) (1997) pattern and process: towards a regional approach to national estate assessment of geodiversity techn. series no. 2, australian heritage commission & environment forest taskforce, environment australia, canberra, 102 pp. ferrari c. & vianello g. (1985) le salse dell’emiliaromagna regione emilia-romagna, collana assess. ambiente, pp. 116-118. gasperi g., cremaschi m., mantovani uguzzoni m.p., cardarelli a., cattani m. & labate d. (1989) evoluzione plio-quaternaria del margine appenninico modenese e dell’antistante pianura. note illustrative alla carta geologica mem. soc. geol. it., 39, 431 pp. gorgoni c. (1998) le salse di nirano e le altre salse emiliane ed acque salate padane. geochimica, genesi ed importanza per la predizione sismica comune di fiorano modenese. 135 pp. gorgoni c. (2003) le salse di nirano e le altre salse emiliane i segreti di un fenomeno tra mito e realtà comune di fiorano modenese. tip. abc, sesto fiorentino (firenze), 128 pp. gorgoni c., bonori o., lombardi s., martinelli g. & sighinolfi g.p. (1988) radon and helium anomalies in mud volcanoes from northern apennines (italy) a tool for earthquake prediction . geochemical journal, 22, pp. 265-273. gruppo di lavoro cpti (1999) catalogo parametrico di terremoti italiani ing-gndt-sga-ssn, bologna, 88 pp. (version available on the web site http://emidius.itim.mi.cnr.it/cpti/home.html/). gruppo nazionale geografia fisica e geomorfologia (1994) proposta di legenda geomorfologica ad indirizzo applicativo geogr. fis. dinam. quat., 16 (1993), pp. 129-152. hose t.a. (1997) geoturism selling the earth to europe in marinos in: p.g. koukis et al. (eds.), engineering geology and the environment, balkema, rotterdam, pp. 2955-2960. johansson c.e. & zarlenga f. (1999) protection of geosites in europe. state and trends mem. descr. carta geol. d’it. 54, pp. 3-22. mori a. (1990) le carte geografiche libreria goliardica, pisa, 294 pp. mucchi a.m. (1966) il fenomeno delle salse e le manifestazioni del modenese atti soc. nat. mat. modena, 97, pp. -31. mucchi a.m. (1968) le salse del modenese e del reggiano. l’universo, 48 (3), pp. 421-436. panizza m. (1992) geomorfologia pitagora ed, bologna, 397 pp. panizza m. (2001) geomorphosites: concepts, methods and examples of geomorphological survey chinese science bulletin, 46, pp. 4-6. panizza m. & piacente s. (2003) geomorfologia culturale pitagora ed., bologna, 350 pp. pantanelli d. & santi v. (1896) l’appennnino modenese ed. cappelli, rocca san casciano, ristampa 1996, ed. iaccheri, pavullo nel frignano. papotti d. (2002) riflessioni preliminari ad una standardizzazione della simbologia per l’escursionismo bollettino dell’a.i.c., no. 114-115, pp. 55-66. pellegrini m., brazzorotto c., forti p., francavilla f. & rabbi e. (1982) idrogeologia del margine pedeappenninico emiliano-romagnolo in: g. cremonini & f. ricci lucchi (eds.), guida alla geologia del margine appenninico-padano, guida geol. reg. soc. geol. it., bologna, pp. 183-189. piacente s. & poli g. (eds.) (2003) la memoria della terra, la terra della memoria università di modena e reggio emilia regione emiliaromagna, edizioni l’inchiostroblu, bologna, 159 pp. piacente s., bertacchini m., coratza p. & malmusi s. (2000) il patrimonio geologico: nuova occasione di sviluppo turistico e culturale. un esempio in emilia-romagna atti. conv. “sviluppo economico e sostenibilità: il turismo ambientale e culturale occassione di nuova occupazione”, 2-6/11/1999, anacapri, 56-563, edizioni l’inchiostroblu, bologna, 159 pp. pieri m. & groppi g. (1981) subsurface geological structure of thepo plain, italy c.n.r., pubbl. 414 p. f. geodinamica, 13, 7, 13 pp. pliny the elder (around 50 a.d.) historia mundi 254 d. castaldini et al. naturalis book ii-85. einaudi ed., torino. poli g. (ed.)(1999) geositi. testimoni del tempo regione emilia-romagna, edizioni pendragon, 259 pp. ramazzini b. (1698) de petrolio montis zibinii modena reynard e., holzmann c., guex d. & summermatter n. (eds.) (2003) géomorphologie et tourisme act. réunion annuelle soc. suisse de géomorphologie, 21-23/9/2003, finhaut (suisse), 216 pp. servizio meteorologico regionale della regione emiliaromagna (1995) i numeri del cl ima ed. promodis italia, brescia, 305 pp. sestini a. (1981) cartografia generale patron ed., bologna. spallanzani l. (1795) viaggi alle due sicilie e in alcune parti dell’appennino pavia. stohr r. (1869) intorno agli strati terziari superiori di montegibbio e vicinanze atti soc. nat. mat. modena, 4. stoppani a. (1873) il bel paese milano, 651 pp. tosatti g. (2002) the mud volcanoes of salse di nirano in: p. coratza & m. marchetti (eds.), geomorphological sites: research, assessment and improvement, workshop proceedings, 19-22 june 2002, modena, pp. 95-97 wimbledon w.a.p., benton m.j., bevins r.e., black g.p., cleal c.j., cooper r.g. & may v.j. (1995) the developement of a british methodology for selection of geological sites for conservation part 1, modern geology, 20, pp. 159-210. 255geo-tourist map of ... sess 5_16022011_edi as.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 the northern part of the study area is characterized by normal faults with regional trending nw-se, while in the southern sector prevail oblique faults with trending ew (pieri et al., 1997; festa, 2003; spalluto et al., 2007). the groundwater in the murgia area is held in a huge aquifer within the mesozoic fractured and karstified bedrock, floating on the sea water, with potential equal to zero where the boundary coincides with the coastline, and variable potential from few tens of meters to zero, on the border with the impermeable deposits of the bradanic foredeep. this impermeable boundary along the w edge of the murgia forces the flow direction towards the taranto area, where the impermeable plugging disappears or tapers in thickness easily siphoned. the average annual recharge of the entire murgian hydrogeological structure was evaluated in 1000 mm3, while the groundwater flow towards the ionian sea is estimated at about 380 mm3 (de girolamo et al., 2002), corresponding to an outflow of the coastal and submarine springs, whose total actual discharge is about 15 m3/s. most part of the aquifer drainage is present, because of the hydro-geo-structural conditions, in the taranto coastal area, with typical important morphological evidences. in particular, the drainage occurs by submarine springs in large erosive basins (the mar piccolo and mar grande), or through coastal springs, with large swamp areas (tara, springs as much as 4 m3/s), or with short channel connection with the sea (the famous historical galeso spring). the deep aquifer has resulted in numerous springs at the edge of the clay cover, both when the hydraulic head was higher than the topographic in the murgia region (apulia, southern italy) quaternary sea level stands and variations with consequent setting of the base level of karst groundwater, played a key role in the evolution of the inland and coastal morphology (canora et al., 2010), particularly in the taranto area. this area is located on the border between two important geological structures: at ne by the murgian foreland and in the w side by the bradanic foredeep. it is characterized by a powerful cretaceous limestone and dolomite bedrock, on which are deposited clastic regressive formations. the recognized stratigraphic sequence is represented by the altamura limestone (cretaceous sup.), the gravina calcarenites (pleistocene inf.), the sub-apennines clays formation (pleistocene inf.), the unity of monte castiglione calcarenites (calabrian-tyrrenian), the terraced marine deposits, as well as continental marsh deposits, recent sand beach deposits and continental eluvio-colluvial and alluvial deposits. the geomorphology of the area is represented by a series of pleistocene terraces that descend to the sea, placed at various altitudes, related to the sea and land variations. these terraces more recent as you approach the sea, are bordered by abrasion sea cliffs, corresponding to successive shorelines almost parallel to the current one. the submerged area of the taranto gulf is formed by a morphologically very troubled southern sector because of the continuation of the apennines, and by the northern sector more flat and uniform typical of the murgian foreland area. the two areas are separated by a deep submarine canyon, taranto channel, which is set along the tectonic lines with apennine trending. from a tectonic point of view little ice age in the taranto area (apulia, southern italy) cosima a. rossi, filomena canora & giuseppe spilotro università degli studi della basilicata, potenza, italia, corresponding author: c.a. rossi <cosima.rossi@unibas.it> abstract: rossi c.a., canora f. & spilotro g., little ice age in the taranto area. (it issn 0349-3356, 2011) the present study focuses on the key role that the interactions of the sea level changes and hydrogeological mechanisms played on the evolution of the interconnected dynamics of the actual geomorphological and hydrogeological system of the taranto area, from the quaternary glacial age to the last little ice age. riassunto: rossi c.a., canora f. & spilotro g., la piccola età glaciale nell’area di taranto (puglia, italia meridionale). (it issn 0349-3356, 2011) il presente studio è relativo al ruolo chiave che le interazioni tra le variazioni del livello del mare e i meccanismi idrogeologici hanno avuto sull’evoluzione delle dinamiche interconnesse dell’attuale sistema geomorfologico ed idrogeologico nell’area di taranto, dall’età glaciale del quaternario fino alla piccola età glaciale. key words: sea level changes, little ice age, taranto area (apulia) parole chiave: variazioni del livello del mare, piccola età glaciale, area di taranto (puglia) 217 218 218 ms. received: testo ricevuto il elevation of the impermeable threshold, and when the springs, due to the siphoning phenomenon of cover clay, came forward on the land and on the sea, forming the typical submarine springs, known as “citri” or “chidri”, in the mar piccolo and mar grande (s. cataldo ring in the mar grande, galeso citro, s. marco citro, cupizze citro, copre citro in the mar piccolo), some of these have the discharge of about 1000 l/s. when the thickness of the clay sediments is thin, or when the clays are fissured, the karst groundwater come out from the clay coverage, resulting in sub-aerial springs, whose evolution, a constant sea level, is determined by the relative elevation of the top of the limestone in that point, respect to sea level. in addition to the important aquifer contained in the fractured and karstified carbonate, modest aquifer are located at the contact between the marine sand or calcarenites of the tyrrhenian terraces and the blue clays. the emergence points of the karst aquifer changed with changes in sea level, resulting in correspondence of the stands, with typical forms similar to those actually active, but which have undergone total or partial fossilization. the discriminating condition stems from the position of the new sea level, respect to the bottom of the basin associated with the siphoning of the groundwater, partially filled by swamp deposits. if the new sea level, is higher than that elevation, part of the sea water enter in the basins, because of the high evapotranspiration. this mechanism has led to the formation of saline taranto (spilotro & locardo, 1993), that correspond to pronounced elliptical flat basins around the ancient karst groundwater emergencies. the sensitive balance of these unique geological morfostrutture makes them the perfect climate indicators, because the reduction of evapotranspiration and the increase of precipitation brings back their swamps, with reversal of water flow towards the sea. the quaternary paleoclimatic evolution has seen a succession of interglacial phases which led to remarkable changes in sea level. the holocene is presented as a post-glacial phase outlining a period of strong heating (up to 9/7 ka b.p.), followed by a slow but gradual cooling. within this trend there are many hot/cold oscillations, in which, at the mid-latitudes, those extraordinary appear to affect the cold period of the little ice age (conventionally defined as the period between about 1600 and 1850) and actual heating (silenzi & antonioli, 2000). among several recent cycles, the little ice age seems to be confirmed in the taranto area by the analysis of the many documents, old maps and historical documents of the period between 1567 and 1850, that clearly indicate the evidence of new climate conditions, which highlighted the recent morphological evolution, explicitly related to the sea level changes during the little ice age, in which there was a prolonged cooling climate by about 1 °c, where the climate changed in a more humid conditions (spilotro & roccanova, 1990). in particular, this analysis shows a historic evolution of those basins correspondent to the saline, which are not too deep. in the maps dating from 1567 to 1585, these basins appear well developed and connected to the sea. in the next maps, dated 1620 and 1692, they disappear and reappear, finally, in the maps of 1771 and 1810. the rebirth of the saline in the last period, as well documented in wide historical literature, caused the beginning of a difficult period, with a high mortality rate, due to climatic situations characterized by a remarkable raise in humidity, with the relative swamping of the area, as well shown in the more recent maps. in conclusion, small variations of the sea level and more noticeable rainfall variations have caused the swamping of wide endorheic areas, internal, nowadays, in taranto urban context, perimetral in the past, and, consequently, awful health conditions. references canora f., convertini a., fidelibus m.d. & spilotro g. (2010) sea level stands, karst hydrology and morphologies throught morphometric analysis in the murgia plateau (apulia, southern italy). atti dip., disgg, unibas, 2, 14 de girolamo a.m., limoni p.p., portoghese p. & vurro m. (2002) il bilancio idrogeologico delle idrostrutture pugliesi: sovrasfruttamento e criteri di gestione. l'acqua 3, 33–45. festa v. (2003) cretaceous structural features of the murge area (apulian foreland, southern italy). eclogae geol. helv., 96, 11 – 22. pieri p., festa v., moretti m. & tropeano m. (1997) quaternary tectonic activity of the murge area (apulian foreland southern italy). ann. di geof., 5, pp.13951404. silenzi s. & antonioli f. (2000) variazioni climatiche oloceniche: analisi geochimica di biomarker marini mediterranei e confronto con altri record. mare e cambiamenti globali, pp.53-76. spalluto l., moretti m., festa v. & tropeano m. (2007) seismically-induced slumps in lowermaastrichtian peritidal carbonates of the apulian platform (southern italy). sedimentary geology, 196, pp.81-98. spilotro g. & locardo a. (2003) l'idrogeologia come principale fattore morfogenetico: l'area di taranto. atti dip. disgg, unibas, 4, 13. spilotro g. & roccanova c. (1990) sea level changes and ancient mapping of taranto area. proc. of 6th int. congress of iaeg, amsterdam, aug. 1990, g. price (ed.), balkema, rotterdam, 235-241.  c.a. rossi, f. canora & g. spilotro january 15, 2011 15 gennaio 2011 << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /none /binding /left /calgrayprofile (dot gain 20%) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /error /compatibilitylevel 1.4 /compressobjects /tags /compresspages true /convertimagestoindexed true /passthroughjpegimages true /createjobticket false /defaultrenderingintent /default /detectblends true /detectcurves 0.0000 /colorconversionstrategy /cmyk /dothumbnails false /embedallfonts true /embedopentype false /parseiccprofilesincomments true /embedjoboptions true /dscreportinglevel 0 /emitdscwarnings false /endpage -1 /imagememory 1048576 /lockdistillerparams 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can be opened with acrobat and adobe reader 5.0 and later.) >> /namespace [ (adobe) (common) (1.0) ] /othernamespaces [ << /asreaderspreads false /cropimagestoframes true /errorcontrol /warnandcontinue /flattenerignorespreadoverrides false /includeguidesgrids false /includenonprinting false /includeslug false /namespace [ (adobe) (indesign) (4.0) ] /omitplacedbitmaps false /omitplacedeps false /omitplacedpdf false /simulateoverprint /legacy >> << /addbleedmarks false /addcolorbars false /addcropmarks false /addpageinfo false /addregmarks false /convertcolors /converttocmyk /destinationprofilename () /destinationprofileselector /documentcmyk /downsample16bitimages true /flattenerpreset << /presetselector /mediumresolution >> /formelements false /generatestructure false /includebookmarks false /includehyperlinks false /includeinteractive false /includelayers false /includeprofiles false /multimediahandling /useobjectsettings /namespace [ (adobe) (creativesuite) (2.0) ] /pdfxoutputintentprofileselector /documentcmyk /preserveediting true /untaggedcmykhandling /leaveuntagged /untaggedrgbhandling /usedocumentprofile /usedocumentbleed false >> ] >> setdistillerparams << /hwresolution [2400 2400] /pagesize [612.000 792.000] >> setpagedevice sess 2_16022011_tpr2.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 plio-quaternary paleoenvironmental evolution across western umbria and tuscany roberto bizzarri1, angela baldanza2 & patrizia argenti3 1via a. capitini, 8-06055 marsciano (pg) 2 dipartimento scienze della terra-università di perugia, perugia 3 lab. paleontologia dei vertebratidip. scienze geologiche università di roma tre, roma corresponding author: r. bizzarri <roberto.bizzarri@libero.it> abstract: bizzarri r., baldanza a. & argenti p., plio-quaternary paleoenvironmental evolution across western umbria and tuscany. (it issn 0394-3356, 2011) the area across western umbria and tuscany records a complex evolution, from early pliocene to late pleistocene, due to the interaction among coastal marine and continental environments, and among tectonics and sedimentation. throughout pliocene, the extensional valdichiana basin underwent marine conditions, but marine deposits encompass different ages across the area. from late pliocene to early pleistocene, a continental, river-dominated environment developed; the gelasian-santernian città della pieve deltaic deposits belong to the “chiani-tevere” cycle and are related to this continental evolution. the trasimeno basin development and the ne tilt of both città della pieve deltaic deposits and valdichiana continental deposits are due to early middle pleistocene regional tectonics. riassunto: bizzarri r., baldanza a. & argenti p., evoluzione paleoambientale plio-quaternaria tra l’umbria occidentale e la toscana. (it issn 0394-3356, 2011) l’area compresa tra l’umbria occidentale e la toscana ha avuto una complessa evoluzione durante il pliocene e il pleistocene, legata agli articolati rapporti esistenti tra ambienti marino costieri e continentali, nonché alla tettonica. nel pliocene, la valdichiana meridionale ospita una sedimentazione marina, ma tali depositi non hanno ovunque la stessa età. un ambiente fluviale si sviluppa tra il pliocene superiore e la fine del pleistocene inferiore; i depositi deltizi di città della pieve appartengono tutti allo stesso ciclo (“chiani-tevere”) e possono essere facilmente correlati, su base sedimentologica e stratigrafica, ad almeno parte dei depositi fluviali della valdichiana. l’impostazione del bacino del trasimeno e la generale inclinazione verso ne dei depositi deltizi di città della pieve e continentali della valdichiana, tra il pleistocene inferiore e medio, dipendono dalla tettonica regionale. key words: sedimentology, paleoenvironmental restoration, pliocene, pleistocene, central italy. parole chiave: sedimentologia, ricostruzione paleoambientale, pliocene, pleistocene, italia centrale. the present-day area across western umbria and tuscany, among the southern valdichiana basin, the trasimeno lake and the tavernelle-pietrafitta basin, underwent a complex evolution from messinian-early pliocene to present day, not yet completely defined. its earliest evolution phases reflect the interaction between marine and continental environments, both referable to valdichiana basin, whereas the successive phases have been strongly influenced by tectonics, such as for the development of trasimeno basin. the aim of this work is to provide data collected during the last years (bizzarri, 2006, 2007; bizzarri & baldanza, 2009; argenti et al., in press) and to compare it with previous interpretations (verri, 1885, 1918; passerini, 1965; jacobacci et al., 1967, 1969; ambrosetti et al., 1977, 1978, 1987; cattuto et al., 1983; costantini & dringoli, 2002; aruta et al., 2004; barchi et al., 2007), in order to propose some reasoned paleoenvironmental and stratigraphic schemes for the study area, mainly for the late pliocene late pleistocene interval (fig.1). the better stratigraphic definition for both città della pieve deltaic deposits and valdichiana trasimeno continental deposits, as well as the sedimentological and paleoenvironmental reconstruction, allow to fix some points. marine deposits show a different age across the area, the older being confined on eastern cetona mt. side and buried under continental units in the trasimeno area. they represent the first depositional cycle (pliocene cycle: ambrosetti et al., 1977, 1987). the città della pieve coastal marine deposits, related to a deltaic environment, are younger and belong all to the same successive depositional cycle (“chiani-tevere” cycle: ambrosetti et al., 1977, 1987); moreover, they are sedimentologically and stratigraphically related to the valdichiana fluvial deposits (bizzarri 2006, 2007; bizzarri & baldanza 2009). deposits belong to a braided river dominated environment, where thick gravel and sand channels alternate to sandy-silty plain massive sediments (bizzarri, 2006; argenti et al., in press). this high -energy environment was associated to the città della pieve deltaic environment evolution (bizzarri, 2006, 2007; bizzarri & baldanza, 2009). the local recovery of anancus arvernensis remains into river channel gravels (vaiano: argenti, 2004; cetona: boscato et al., 2008) docu 81 83 82 zarri et al., 2008; argenti et al., in press). in the t. tresa area, alluvial fan to piedmont deposits outcrop, and their occurrence seems to be confined to tasso f.u.. in the tavernelle-pietrafitta area, a progressing transition from lacustrine to swampy deposits took place during the tasso farneta interval. finally, sandy and silty-clayey deposits are widely diffused in the area from the farneta abbey to the città della pieve hills. deposits are still related to a fluvial environment: the prevailing sandy sedimentation, with common st and sp crosslaminations, testifies of a less energetic and more organized river pattern. sandy channel deposits are intermingled to clay, the latter bearing paleosoils and sheetflood deposits and indicative of a wider and more stable alluvial plain. as at the tasso f.u. interval occasional communications occurred among the tavernelle basin and the sea nearby, the pietrafitta swamp environment can be imagined as a lateral and temporary abandoned river branch, now clearly related to valdichiana continental environment. difference in age among deltaic deposits related to valdichiana rivers suggest a progressive shift southward of basin depocenter (fig. 1), presumely related to a tectonic activity of eastern cetona master fault (barchi et al., 2007). the on-set of the trasimeno basin is related to ne rotation of the area between early and middle pleistocene, that is also responsible for the northeastward inclination of both città della pieve deltaic deposits and valdichiana continental deposits (fig. 1). the evolution model underlines a progressive sea-retreat south-westward during early pleistocene, probably representing the first indication of the regional extensional tectonics, which deeply modified the area from middle pleistocene onwards. this main event is about 1 my younger than what thought by ambrosetti et al., (1977, 1987) and cattuto et al. (1983): in fact, it is not due to the so called “acquatraversa” phase (piacenzian: ambrosetti et al., 1977, 1987) but represents the consequences of a successive regional tectonics, as inferred by barchi et al. (2007). in our reconstruction, the main unconformity separating, on seismic sections, valdichiana marine and continental deposits (u1 unconformity of barchi et al., 2007) can be referred to “acquatraversa”: in that case, this phase represents the moment of diffuse ments the occurrence of middle villafranchian faunas. as the southern valdichiana was characterized by high energy rivers, draining toward the near marine coast and building a large and steady fan-delta in the città della pieve area, the tavernelle-pietrafitta area represented an intermountain closed basin. in the valdichiana continental basin, a stable alluvial plain environment persists until the end of early pleistocene (fig. 1). the majority of fossil record regards tasso and, principally, farneta f.us (argenti, 2004 cum biblio). three main depositional continental environments are documented in the area through the end of middle villafranchian and the late villafranchian (bizzarri, 2006; pazzaglia, 2007; barchi et al., 2007; bizfig. 1, evolution of the study area from late pliocene to late pleistocene. evoluzione dell'area tra il pliocene superiore e il pleistocene superiore. r. bizzarri, a. baldanza & p. argenti 83 ms. received: testo ricevuto il soc. geol. it., nuova serie, 5, 54-56. bizzarri r. (2006) depositi plio-pleistocenici tra la val di chiana e il lago di corbara: caratterizzazione sedimentologica e ricostruzione paleoambientale. phd thesis, perugia university, 408 p. bizzarri r. (2007) late pliocene-early pleistocene fluvial paleocoasts in western umbria (central italy): facies analysis and sedimentation models. geoitalia epitome, 2, 393-394. bizzarri r. & baldanza a. (2009) – plio-pleistocene deltaic deposits in the città della pieve area (western umbria, central italy): facies analysis and inferred relations with the valdichiana fluvial deposits. il quaternario, 22 (2), 127-138. bizzarri r., pazzaglia f., barchi m.r., passeri l. & argenti p. (2008) inquadramento stratigrafico dei depositi continentali quaternari nel f. 310 “passignano sul trasimeno” ed evoluzione dei bacini pliopleistocenici del confine tosco-umbro. atti del convegno “il quaternario nella cartografia carg” (roma, 21-22 febbraio 2008), p. 10. boscato p., coltorti m. & reggiani p. (2008) pliocene anancus arvernensis (croizet & jobert, 1828) remains from cetona (siena): stratigraphy, chronology and paleoenvironment. boll. soc. geol. it., 127 (1), 151 -162. cattuto c., gregori l. & parisi g. (1983) indizi di tettonica pleistocenica nel bacino del t. tresa (lago trasimeno). geogr. fis. dinam. quat., 1, 16-20. costantini a. & dringoli l. (2002) – geologia dell’area fra chianciano bagni e sarteano (provincia di siena). carta geologica, università di siena. s.e.l.c.a., firenze, 2002. jacobacci a., malatesta a. & martelli g. (1969) note illustrative della carta geologica d'italia alla scala 1:100000; foglio 121 "montepulciano". serv. geol. d'italia. jacobacci a., martelli g. & nappi g. (1967) note illustrative della carta geologica d'italia alla scala 1:100000; foglio 129 "santa fiora". serv. geol. d'italia. passerini f. (1965) – il monte cetona (provincia di siena). boll. soc. geol. it., 83 (4), 219-338. pazzaglia f. (2007) evoluzione tettonico – sedimentaria dei bacini quaternari minori tra la val di chiana e il bacino tiberino. phd thesis, perugia university, 193 p. verri a. (1885) la val di chiana nel periodo pliocenico. boll. soc. geol. it., 4, 1-13. verri a. (1918) l'altopiano di città della pieve. boll. soc. geol. it., 37, 53-92. valdichiana continentalization. the data here proposed provide a paleoenvironmental characterization of valdichiana from early pliocene to holocene, according to both literature data on sarteano -cetona area (costantini & dringoli, 2002), and to seismic sections (barchi et al., 2007). though, some minor adjustments are needed, and the studies are still in progress. references ambrosetti p., carboni m.g., conti m.a., costantini a., esu d., gandin a., girotti o., lazzarotto a., mazzanti r., nicosia u., parisi g. & sandrelli f. (1978) evoluzione paleogeografica e tettonica nei bacini tosco umbro laziali nel pliocene e nel pleistocene inferiore. mem. soc. geol. it., 19, 573-580. ambrosetti p., conti m.a., parisi g., kotsakis t. & nicosia u. (1977) neotettonica e cicli sedimentari plio -pleistocenici nei dintorni di città della pieve (umbria). boll. soc. geol. ital., 96, 605-635. ambrosetti p., carboni m.g., conti m.a., esu d., girotti o., la monica g.b., landini b. & parisi g. (1987) il pliocene ed il pleistocene inferiore del bacino del fiume tevere nell'umbria meridionale. geogr. fis. dinam. quat., 10, 10-33. ambrosetti p., cattuto c. & gregori l. (1989) geomorfologia e neotettonica nel bacino di tavernelle/ pietrafitta (umbria). il quaternario, 2 (1), 57-64. argenti p. (2004) plio-quaternary mammal fossiliferous sites of umbria (central italy). geol. romana, 37, 67-78. argenti p., bizzarri r. & pazzaglia f. (in press) iv.5 successioni dei bacini sedimentari plio-pleistocenici. in: m. barchi, m. marroni (a cura di) note illustrative della carta geologica d’italia alla scala 1:50.000 foglio 310 “passignano sul trasimeno”, 74-99. ispra, regione umbria. aruta g., borgia a., bruni p., cecchi g., cipriani n. & tredici y. (2004) – pliocene and pleistocene unconformity bounded stratigraphic units (ubsu) in val di chiana. in: morini d & bruni p. (eds.), the “regione toscana” project of geological mapping. firenze, 133136. barchi m.r., bortoluzzi g., gasperini l., ligi m. & pauselli c. (2007) – tectono-sedimentary evolution of the lake trasimeno: a seismic reflection study rend. plio-quaternary paleoenvironmental evolution across ... january 14, 2011 14 gennaio 2011 sess 5_16022011_edi as.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 an early holocene transitory arid phase in the central sahara at the time of the 8.2 ky bp climate anomaly andrea zerboni dipartimento di scienze della terra “a. desio”, università degli studi di milano corresponding author: a. zerboni <andrea.zerboni@unimi.it> abstract: zerboni a., an early holocene transitory arid phase in the central sahara at the time of the 8.2 ky bp climate anomaly. (it issn 0349-3356, 2011) the beginning of the holocene in the sahara is marked by increased rainfall due to the expansion of the african monsoon over the north africa. in the central sahara springs were activated in the mountains and shallow lakes formed between dunes. an isotopic and geochronological approach to the study of spring and lake carbonates allowed defining the beginning of the holocene humid period; moreover, data show its abrupt interruption at c. 8 ky bp. the arid spell is attributed to the 8.2 ky bp event and its significance is discussed in the frame of holocene climate changes recorded in north africa and in the mediterranean. riassunto: zerboni a., una breve fase arida registrata nel sahara centrale in corrispondenza dell’anomalia climatica di 8.2 ky bp. (it issn 0349-3356, 2011) l’inizio dell’olocene nel sahara è marcato da un incremento delle precipitazioni causato dall’espansione dell’area di influenza monsonica sul nord africa. nel sahara centrale furono attivate sorgenti nelle aree montane e si formarono laghi tra le dune. lo studio isotopico e geocronologico di carbonati lacustri e di sorgente ha permesso di definire l’inizio della fase umida olocenica e di identificare un evento arido a 8 ky bp. tale evento è posto in relazione con l’anomalia climatica di 8.2 ky bp e il suo significato viene discusso nell’ambito delle variazioni climatiche registrate in nord africa e nel bacino del mediterraneo. key words: climate changes, palaeohydrological records, 8.2 event, african monsoon, sahara. parole chiave: cambiamenti climatici, archivi paleoidrologici, evento 8.2, monsone africano, sahara. 1. introduction the palaeoenvironmental research carried out in the hyperarid central sahara (sw libya) permitted to elucidate the time and steps of the holocene climatic changes occurred in the region (cremaschi & zerboni, 2009). the isotopic and geochronological study of carbonatic sediments related to highly sensitive palaeohydrological archives (cremaschi et al., 2010) allowed to date the beginning of humid phase and evidenced the role played by the 8.2 ky bp climate anomaly. 2. methods spring and lake sediments were discovered and sampled during a geoarchaeological survey. spring tufa were dated using multicollector icp-ms techniques (details in fleitmann et al., 2007). organic lake sediments were radiocarbon dated and ages calibrated (2σ) using the intcal04 calibration curve (reimer et al., 2004). the stable cand o-isotope values were measured using a thermofinngan deltaplusxl isotope ratio mass spectrometer and results are reported in ‰, relative to the vienna peedee belemnite (vpdb).  3. results and discussion tufa formation typically required abundant water and a continuous soil cover in order to account for co2 input into the groundwater system. according to u-th data such conditions lasted from 9.6 to 7.6 ky bp (fig. 1a). stable isotopes recorded a trend towards wetter conditions between 9.6 and 8.8 ky bp, whereas, after a hiatus, less negative δ18o values suggest a reduction in precipitation (fig. 1b). a major hydrological change is also evident from the δ13c versus δ18o cross plot, differentiated on the basis of u/th ages: tufa deposited before 9 ky bp shows δ18o values ranging from -12 to -9‰, while younger tufa shows values ranging from -9 to -2‰ (fig. 1c), suggesting higher rain supply to springs and soil metabolism at the beginning of the period, followed by a progressive decline (cremaschi et al., 2010). conditions suitable for tufa formation were substantially reduced c. 8 ky bp, whereas the occasional persistence of local tufa deposition until c. 7.6 ky bp may be related to the resilience of water saturation in parts of the mountain. carbonatic lake deposits discovered in the sand seas indicates former, large groundwater-fed water bodies, which origin was directly linked to the 225 227 226 amount of rainfall feeding confined, surface aquifers. more than 70 samples of organic lake sediment have been dated, reflecting holocene age. groundwater seepage is recorded from 8.9 to 1.6 uncal. ky bp, but most of the results are concentrated in the interval 10.5–5.5 cal. ky bp. limnic activity is well dated in the edeyen of murzuq, due to the existence of deep organic to carbonate-rich lacustrine sections; two distinct water high stands were identified, interrupted by an arid phase between c. 8.2 and 7.8 cal. ky bp. hydrological changes recorded in the central sahara agree well with records of climate changes in the surrounding region (fig. 2); for instance, a gap in sedimentation and erosion under arid conditions are registered by anthropogenic cave deposits from the tadrart acacus massif (cremaschi et al., 2010). the attribution of the dry phase recognized in the study area to the 8.2 event is consistent with a palaeoclimatic model proposed by wiersma & renssen (2006). an anomaly at 8.2 ky bp was identified in many proxy records from the african monsoon region (mayewski et al., 2004). a drop in precipitation was recorded by summer-monsoon-fed lakes between 8.5 and 7.8 cal. ky bp (fig. 2) and was reported from several continental records from the circummediterranean region (berger & guilaine, 2009). finally, the arid spell was largely coeval with the relapse within sapropel s1 in the mediterranean sea, supporting the hypothesis concerning a strong correlation between weakening in the african monsoon intensity and interruption of anoxic events in the eastern mediterranean (rohling et al., 2002). fig. 1, a) duration of tufa deposition in each locality. (b) o-isotope profile of sample 02/99. (c) δ13c versus δ18o data differentiated on the base of u/th ages (from cremaschi et al., 2010). (a) durata della deposizione di calcareous tufa in ogni località. (b) curva isotopica del campione 02/99. (c) dati isotopici (δ13c versus δ18o) differenziati sulla base delle datazioni u/th (da cremaschi et al., 2010). a. zerboni 227 ms. received: testo ricevuto il 4.conclusion deposition of carbonates in today’s hyperarid central sahara records a prolonged period of wet climate which prevailed during the early holocene in response to a northward expansion of the sw african monsoon system, controlled by the insolation maximum. the available data suggest a gap in sedimentation between 8.2 and 7.8 ky bp. probably triggered by the abrupt drainage of laurentide lakes and subsequent slowdown of the north atlantic thermohaline circulation (thomas et al., 2007), this event led to a temperature reduction in the guinea gulf and a strong decrease in evaporation. as a consequence, the strength of the african monsoon decreased, with the sudden shutdown of water supply to the central sahara and reduction of runoff to the mediterranean sea. references berger j.-f. & guilaine g. (2009) the 8200 cal bp abrupt environmental change and the neolithic transition: a mediterranean perspective. quaternary international, 200, 31-49. cremaschi m. & zerboni a. (2009) early to middle holocene landscape exploitation in a drying environment: two case compared from the central sahara (sw fezzan, libya). comptes rendus geoscience, 341, 689-702. cremaschi m., zerboni a., spötl c. & felletti f. (2010) the calcareous tufa in the tadrart acacus mt. (sw fezzan, libya). an early holocene paleoclimate archive in the central sahara. palaeogeography, palaeoclimatology, palaeoecology, 287, 81-94. fleitmann d., burns s.j., mangini a., mudelsee m., kramers j., villa i., neff u., al-subbarye a., buettner a., hippler d. & matter a. (2007) holocene itcz and indian monsoon dynamics recorded in stalagmites from oman and yemen (socotra). quaternary science reviews, 26, 170-188. mayewski p.a., rohling e., stager j.c., karlen w.k., maasch k.a., meeker l.d., meyerson e.a., gasse f., van kreveld s., holmgren k., lee-thorp j., rosqvist g., rack f., staubwasser m., schneider r. & steig e.j. (2004) holocene climate variability. quaternary research, 62, 243-255. reimer p.j., baillie m.g.l., bard e., bayliss a., beck j.w., bertrand c.j.h., blackwell p.g., buck c.e., burr g.s., cutler k.b., damon p.e., edwards r.l., fairbanks r.g., friedrich m., guilderson t.p., hogg a.g., hughen k.a., kromer b., mccormac g., manning s., bronk ramsey c., reimer r.w., remmele s., southon j.r., stuiver m., talamo s., taylor f.w., van der plicht j. & weyhenmeyer c.e. (2004) intcal04 terrestrial radiocarbon age calibration, 0–26 cal ky bp. radiocarbon, 46, 10291058. rohling e.j., cane t.r., cooke s., sprovieri m., bouloubassi i., emeis k.c., sciebel r., kroon d., jorissen f.j., lorre a & kemp a.e.s. (2002) african monsoon variability during the previous interglacial maximum. earth and planetary science letters, 202, 61-75. thomas e.r., wolff e.w., mulvaney r., steffensen j.p., johnsen s.j., arrowsmith c., white j.w.c. vaughn b. & popp t. (2007) the 8.2 ka event from greenland ice cores. quaternary science reviews, 26, 70-81. wiersma a.p & renssen h. (2006) model–data comparison for the 8.2 ka bp event: confirmation of a forcing mechanism by catastrophic drainage of laurentide lakes. quaternary science reviews, 25, 63-88. an early holocene transitory arid phase in the ... january 14, 2011 14 gennaio 2011 fig. 2, palaeohydrological records from the central sahara compared with other archives from north africa and the mediterranean region; the grey bar indicates the 8.2 event (thomas et al., 2007). record paleoidrologici centrosahariani comparati con altri record paleoclimatici dal nord africa e dall’area mediterranea; la barra grigia indica l’evento 8.2 (thomas et al., 2007). << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /none /binding /left /calgrayprofile (dot gain 20%) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /error /compatibilitylevel 1.4 /compressobjects /tags /compresspages 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/hrv (za stvaranje adobe pdf dokumenata najpogodnijih za visokokvalitetni ispis prije tiskanja koristite ove postavke. stvoreni pdf dokumenti mogu se otvoriti acrobat i adobe reader 5.0 i kasnijim verzijama.) /hun 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/pdfxoutputintentprofileselector /documentcmyk /preserveediting true /untaggedcmykhandling /leaveuntagged /untaggedrgbhandling /usedocumentprofile /usedocumentbleed false >> ] >> setdistillerparams << /hwresolution [2400 2400] /pagesize [612.000 792.000] >> setpagedevice sess 4_17022011.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 geoarchaeologic methods applied to preventive archaeology. a new perspective for archaeologists and quaternary scientists mauro cremaschi & chiara pizzi dipartimento di scienze della terra “a. desio”, università degli studi di milano corresponding author: m. cremaschi <mauro.cremaschi@unimi.it> abstract: cremaschi m. & pizzi c., geoarchaelogic methods applied to preventive archaeology. a new perspective for archaeologists and quaternary scientists.. (it issn 0349-3356, 2011) the applications of geoarchaeology in the frame of the preventive archaeology are discussed on the basis of the public contracts code (legislative decree no. 163/2006) and of some case studies in different archaeological contexts. riassunto: cremaschi m. & pizzi c., metodi geoarcheologici applicati all’archeologia preventiva. una nuova prospettiva per archeologi e scienziati del quaternario. (it issn 0349-3356, 2011) viene discusso il ruolo della geoarcheologia nelle operazioni di archeologia preventiva sulla base del codice dei contratti pubblici (d.lgs. 163/2006, art. 95: verifica preventiva dell’interesse archeologico in sede di progetto preliminare) e mediante l’illustrazione di alcuni casi di studio da contesti archeologici diversi. key words: geoarchaeology, preventive archaeology, cultural heritage. parole chiave: geoarcheologia, archeologia preventiva, beni culturali. within the upper geological layers of the continents is enclosed evidence of two million years of human activity, in the form of archaeological sites. these include a wide range of evidence, from the city of pompeii, perfectly preserving structures and materials connected to daily life, (thanks to the dramatic eruption of vesuvius that buried it rapidly), to the bivouac of palaeolithic hunters, testified to by a few scattered stone tools within a soil. but also buried soils with traces of wood clearance and ploughing, or tested flint nodules in a chert outcrop, and any other evidence recording the impact of human activity on the territory (fig. 1), are to be considered archaeological sites. all together, these objects form an invaluable archive to understand how humanity has developed over time, adapting the subsistence strategies to the changing environment. the archaeological sites are also an important part of the historical memory of nations, and are widely used in cultural activities and in educational performances; in this sense they constitute a significant opportunity for economic activities and a wealthy source of profit. most of the developed countries have implemented protection policies of the archaeological heritage and laws that support them as its preservation often conflicts with the requirements of land management (for building, motorway and railway construction, agriculture, etc.). specific procedures are to be considered to mitigate the damage that could ensue from uncontrolled intervention (liverani et al., 2000; anag et al., 2002; bernabò brea & valloni, 2009; inrap, 2009). in italy (malnati, 2005), these procedures have been recently elaborated in the public contracts code (legislative decree no. 163/2006), which contains the rules on so-called preventive archaeology (article 95: verification of preventive archaeological interest in the preliminary draft). this includes a stage of preliminary documentation and subsequent test-operations. availing themselves of working professionals, the leaders of the management projects estimate, already in the planning phase, the so-called "archaeological risk", enabling both contractors and the archaeological heritage service (soprintendenza per i beni archeologici) to assess the chance of discovering, in the working areas, archaeological evidence subject to protection, and to evaluate the possibility of removing it, and the time and cost of removal (malnati, 2005). the law determines who is allowed to achieve these objectives: the departments of archaeology of the university and the professionals possessing specific qualifications in the field of archaeology (phd and/or post doc in archaeology). no mention is made of geoarchaeologists (cremaschi, 2010), the archaeologists who have a study career in geology or natural sciences, although the law provides for operations such as geomorphological mapping, core drilling, geophysical and "geochemical" survey, which definitely require specific knowledge in earth sciences (cremaschi, 2000). furthermore, geoarchaeologists in recent decades have found a place in many professional companies that deal with archaeological excavations, and often have duties and responsibilities of leadership. geoarchaeology provides the main operational tools and methodology to optimize the scientific practice that regards preventive archaeology. to 180 182 181 fig. 1, buried soils, and associated archaeological sites, record the impact of human activity on the territory. the case of buried soils in the central po plain (rubiera, re). i suoli sepolti, e i siti archeologici ad essi associati, conservano evidenze dell’impatto umano sul territorio. è il caso, ad esempio, dei suoli sepolti nelle alluvioni della pianura padana centrale (rubiera, re). fig. 2, geoarchaeologists at work: coring the bronze age site of qatna in central syria (left) and performing a geophysical survey (right) in the central po plain (terramara s. rosa, re). geoarcheologi al lavoro: perforazioni presso il sito archeologico dell’età del bronzo di qatna, nella siria centrale (a sinistra) e durante una campagna di rilevazioni geofisiche (a destra) nella pianura padana centrale (terramare di s. rosa, re). geoarchaelogic methods applied to preventive archaeology 182 ms. received: testo ricevuto il be perceived, understood and protected, archaeological sites must be studied and surveyed through an earth-science approach as, at any scale, the material traces of human activities, once produced and abandoned by their authors, become a part of the earth system (cremaschi, 2010); and thus, as any object on the surface of the planet, they are exposed to the processes of erosion, transport and weathering. geomorphologic surveying, together with remote sensing, allows detection of geomorphologic processes that have acted in the past (among them those induced by human activity; cremaschi, 2000). it permits us to reconstruct the archaeological landscape, distinguishing the suitability of the different landscape segments for conservation of the archaeological evidence. coring, pedological and sedimentological analysis, and geophysical survey, are the most effective tools for operating at the margins and inside of the archaeological sites (fig. 2), to estimate their extent, shape, consistency and degree of preservation, all without the need for extensive excavations (some cases of study are provided by surveys concerning arid zones, core drilling in urban areas, reconstruction using dtm and geophysical survey of terramare). consequently, this increases the efficiency of preventive archaeology operations, while optimizing the time employed and lowering the costs. there is now extensive agreement among soprintendenze archeologiche and many archaeologists involved in the archaeological heritage protection on the need to complete the existing law, giving the right geoarchaeology and its operators their proper place. it is useful for the scientific community of earth sciences to take up this issue. for scientific reasons, but also because the preventive archaeology requiring geoarchaeological knowledge, constitutes a significant professional opportunity for young graduates in the sciences. references anag g., cremaschi m., di lernia s. & liverani m. (2002) environment, archaeology, and oil: the messak settafet rescue operation (libyan sahara). african archaeological review, 19, 67-73. bernabò brea m. & valloni r. (2009) archeologia ad alta velocità. edizioni all’insegna del giglio. firenze. cremaschi m. (2000) manuale di geoarcheologia. laterza, bari. cremaschi m. (2010) geoarcheologia in italia oggi – che fare? notiziario a.i.ar., 16-17, 23-26. inrap (2009) preventive archaeology. http:// www.inrap.fr/preventive-archaeology/preventivearchaeology/definition/p-1385-lg1-definition.htm. liverani m., cremaschi m. & di lernia s. (2000) the “archaeological park” of the tadrart acacus and messak settafet (south-western fezzan, libya). a preliminary project. sahara 12, 121-140. malnati l. (2005) la verifica preventiva dell'interesse archeologico. aedon, rivista di arte e diritto on line, 3, 1-10 january 31, 2011 31 gennaio 2011 m. cremaschi & c. pizzi quaternario 6 1993 p 145-166_page_0001 quaternario 6 1993 p 145-166_page_0002 quaternario 6 1993 p 145-166_page_0003 quaternario 6 1993 p 145-166_page_0004 quaternario 6 1993 p 145-166_page_0005 quaternario 6 1993 p 145-166_page_0006 quaternario 6 1993 p 145-166_page_0007 quaternario 6 1993 p 145-166_page_0008 quaternario 6 1993 p 145-166_page_0009 quaternario 6 1993 p 145-166_page_0010 quaternario 6 1993 p 145-166_page_0011 quaternario 6 1993 p 145-166_page_0012 quaternario 6 1993 p 145-166_page_0013 quaternario 6 1993 p 145-166_page_0014 quaternario 6 1993 p 145-166_page_0015 quaternario 6 1993 p 145-166_page_0016 quaternario 6 1993 p 145-166_page_0017 quaternario 6 1993 p 145-166_page_0018 quaternario 6 1993 p 145-166_page_0019 quaternario 6 1993 p 145-166_page_0020 quaternario 6 1993 p 145-166_page_0021 quaternario 6 1993 p 145-166_page_0022 quaternario 6 1993 p 145-166_page_0023 available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 37 (1), 2024, 53-65 closed by the drainage systems of the piave and livenza rivers (fig. 1). the cansiglio plateau is a limestone massif featuring a central polje set at around 1,000 m a.s.l. encircled by ridges at elevations of 1,500 m, delimited to the east and to the south by tectonic lines joining to the west with the more important belluno line. to the northwest, the cansiglio is connected to the santa croce late-glacial lacustrine basin by a gentle and vast slope. the cansiglio has an independent drainage system. this clearly increases its already karstic nature as testified by the countless dolines, sinkholes, and other features. a steep slope connects the cansiglio with the livenza karst spring system located to the southeast at the foot of the mountain. the highest elevation is reached at the cavallo mount (2,251 m a.s.l.), a group of peaks limited by glacial circles and ridges. superficial deposits and landforms of palughetto are assigned to three episodes of the piave glacier. two well-preserved moraine ridges associated to fluvioglacial landforms are referred to the younger (c) and intermediate (b) episodes, while the older (a) episode is related to the spread of diamicton containing quartzites, sandstones and volcanoclastic sandstones, quartzitic phyllites, siltstones, micaschists, and igneous rocks typical of the piave alpine basin (avigliano et al., 2000). the last c episode dammed the basin to the north (fig. 2). a https://doi.org/10.26382/amq.2024.03 1. introduction previous investigations confirmed that the palughetto basin at the northern edge of the cansiglio plateau, in the eastern italian pre-alps, has a rich potential for late glacial palaeobotanical research (see avigliano et al., 2000; vescovi et al., 2007). in earlier excavations cones, needles and parts of trees were found in the palughetto peat bog, and during coring, pieces of a spruce trunk were recovered. hence, it appeared promising to conduct further excavation. in 2006 a multi-disciplinary group, including students from several universities in italy and germany, conducted a field week at the site in the frame of wider research projects. here we focus on the mega remains that were recovered (trunks, branches, roots) and their dendrochronology and described in a preliminary report (friedrich et al., 2009). 2. presentation of the palughetto basin on the cansiglio plateau and summary of the pollen sequence the palughetto is a lacustrine basin situated on the northern edge of the cansiglio plateau at 1,040 m a.s.l., in the venetian and carnic pre-alps, and enlate glacial tree-ring chronologies from palughetto bog, veneto pre-alps, italy michael friedrich 1,2 , bernd kromer 2 , marco peresani 3,4 1 hohenheim university, institute of botany, stuttgart, germany. 2 institute of environmental physics, heidelberg university, heidelberg, germany. 3 university of ferrara, department of humanities, prehistoric and anthropological sciences unit, ferrara, italy. 4 institute of environmental geology and geoengineering, national research council, milano, italy. corresponding author: marco peresani <marco.peresani@unife.it> abstract: a late-glacial / early-holocene lacustrine and peat succession, with conifer macro-remains and including some palaeo-mesolithic flint artefacts, was investigated in several steps in the palughetto intermorainic basin (venetian pre-alps). published data on the geomorphic and stratigraphic relations, 14c chronology, pollen series and archaeology allow a reconstruction of the environmental history of the basin and provide significant insights into the reforestation and human peopling of the pre-alps. in this dendrochronological study, we analysed 203 trunks and branches from the subfossil tree assemblage of palughetto mire, resulting in seven groups of 34 trees, which fall in a period of 1600 years of the bølling-allerød interstadial between c. 14,90012,800 cal bp. cross dating was facilitated by numerous decadal ams 14c age determinations. most of the trees were not found ‘in situ’. they fell into the wetland and were preserved in the sediment. the forest mainly consisted of the species spruce (picea abies karst.), larch (larix decidua mill.), birch (betula pubescens erh.), poplar (populus sp.) and willow (salix sp.), confirming results from palynology and botanical remains analyses. growth rates are different for each species. spruce trees show wide rings and ‘complacent’ tree growth. larch tree rings were narrower with higher interannual variability. the high growth rate of spruce indicates favourable growing conditions such as moderate temperatures and sufficient water supply during the vegetation period of the bølling-allerød in palughetto, which is similar to the modern situation of the area. keywords: vegetation history, archaeology, late glacial, eastern pre-alps. lacustrine-palustrine succession deposited in this small intermorainic basin at palughetto until the opening of a sinkhole at the ne edge of the basin leading to the activation of a vertical drainage pattern. three archaeological sectors were identified in the area investigated, the first two refer to human settlements at the end of the recent epigravettian on moraines b and c (respectively palughetto mo and palughetto mn), the third one within the peat-bog near its nw boundary is dated to the sauveterrian period (palughetto ust6; peresani et al., 2011). palughetto sites are part of a late palaeolithic and early mesolithic ensemble of settlements system discovered in the cansiglio plateau and surroundings (peresani et al., 1999-2000; visentin et al., 2016). 3. the stratigraphic sequence the stratigraphic sequence was explored at the nw boundary of the basin through pits, trenches, and extensive archaeological excavations. the basin fill unconformably overlies a basal diamicton and gently inclines southeastwards, rapidly thickening towards the inner basin. three main groups of lithoand pedostratigraphic units were observed (fig. 3; avigliano et al., 2000): units t14-t11, are deposits composed of light-gray clayey silt and silt laminae with rare, striated pebbles (t14), dark-gray silt (t13), massive light-gray clay poor in organic matter with sporadic dwarf pine (pinus mugo) cones (t12) and silty clay gradual coarsening to silt with organic matter (thin organic debris, sporadic birch leaves and larch cones still in connection with their bearing branchlets, sporadic dwarf pine cones) increasing upwards (t11). at the top of t11 there are thin laminae rich in organic debris, i.e., broad-leaved leaves (alnus and betula) and needles (larix). the upper contact with the overlying organic deposits is transitional, marked by a rapid increase in leaves and cones and other organic debris. units t10-t7 compose a thick organic layer extended above the clay-silt succession throughout the basin. the base layer is organic mud (gyttja) rich in plant debris (conifer needles, characeae oogones, mosses, sporadic cones), overlaid by sedentary peat deposits. t10 is a moderately humified litter made of needles and very rich in cones and branchlets. larix decidua is the main peat-forming plant. t9 is a highly humified peat made of wood, bark, branches, roots, needles, fruits, and thin interbeds rich of mosses. vegetative parts of trees (both conifers and broad-leaved plants) are abundant throughout this unit, but its middle part is dominated by woody material, such as branches, crashed trunks, and in situ stumps. t8 is a thin layer of reddish little-decomposed laminated moss-peat rich 54 friedrich m. et al fig. 2 the palughetto area with the three glacial episodes (a, b and c) recognised and position of the palaeolithic sites palughetto mn and palughetto mo (on the moraine ridges c and b respectively) and of the excavated area for dendrochronology at the northern side of the basin. key: 1, glacial deposit; 2, moraine ridge; 3, loess cover; 4, fluvioglacial stream trace; 5, fluvioglacial fan; 6, present-day drainage; 7, silty clay and peat deposits; 8, dolines and sinkholes; 9, eluvial-colluvial and slope waste deposit; 10, excavated of the excavated area for dendrochronology; 11, palaeolithic site (after avigliano et al. 2000, modified). fig. 1 map of a part of venetian pre-alps showing the extent of the piave glacier (shaded) during the lgm. the inset shows the location of the larger map within the region. the rectangle shows the area of the cansiglio plateau (after avigliano et al., 2000). pond during the entire time span of the bølling-allerød interstadial complex, after buried at the onset of the younger dryas. the palaeoenvironmental history of the basin is based on two high resolution (60 years each sample) pollen records, a first one from the littoral, and a second one from the central basin infill (ravazzi & vescovi, 2009). after the glacier retreat, as early as 16 ka cal bp pinus mugo scrubs had already extended over the sunny slopes surrounding the lake, whereas the bottoms and karstic plateaux were occupied by steppes, mostly formed by chamephytes (fig. 4.1). at 15.0±0.6 ka cal bp pinus mugo was hanging on the lake shore, as testified by direct 14c-dating on in situ fossil cones. at 14.7 ka cal bp the altitude of palughetto was override by an advancing larch-spruce forest (fig. 4.2). the lag between trees establishment and forest closure is roughly shown by sedimentary interval of increasing appercentage values and constrained by boundary stable conditions. a closed canopy was established since 14.3 ka cal bp, thus the development of forest population took about 4 centuries. this estimate helps in the evaluation of the diachronism between climate change and the duration of the triggered vegetation response. furthermore, these forest dynamics attest the participation of larch and spruce in the early afforestation of the mountain belt in the south-eastern alps at the beginning of the bøllingallerød interstadial complex. considering the time lag of picea immigration in the inner alps, which occurred several hundred years later than at palughetto, it is proposed that the lateglacial spruce settled on the cansiglio plateau acted as founding populations for the subsequent holocene migration towards inner and western ranges of the alps (ravazzi, 2002). between 14.7 and 13.7 ka cal bp a dense conifer forest occupied the cansiglio plateau and the surrounding slopes, until 1700 m a.s.l.. meantime the conifer forest expanded toward the basin centre and trees of larix, picea and betula settled on peat, thus forming an accumulation of trunks, cones, litter, i.e. the fossil forest preserved in units t10 and t9 (fig. 4.3). afterwards (13.8 to 12.85 ka cal bp), broad-leaved tree species immigrated in the prealpine region, but expansion took place at a quite slower rate and probably broad-leaved individuals did not get the altitude of palughetto, perhaps owing to its northern aspect and to the competition by previously settled conifers. the northern border of the palughetto basin continued to sustain a (larix)-picea-betula forest, accumulating coarse debris of trunks, wood and bark (woody peat) in unit t9 (fig. 4.3). the onset of younger dryas at 12.85 ka cal bp triggered a forest withdrawal from the palughetto wetlands, whereas the well-drained slopes continued to sustain a closed conifer forest throughout the younger dryas (fig. 4.4). the transition to the holocene is marked by the arrival of several broad-leaved species competing with larch and spruce. the first holocene millennium is characterized by mixed forests (fig. 4.5). paleo-mesolithic hunters settled the border of the peat bog (fig. 4.6). in picea and larix needles, covering unit t9 with a sharp boundary. t7 is a thin layer formed by moderately decomposed cyperaceae-peat, laminated, including sporadic picea needles and larix branchlets at its base. t9 also contains fragments of charred wood, late epigravettian and early mesolithic lithic artifacts (peresani et al., 2011) and a lithic cache (bertola et al., 1997) discovered during survey in 1995 and archaeological excavation in 1997 and 2001. units t6-t1 show pedogenic features. a sharp, undulating boundary separates t7 from t6, a gray clay silt with rarely preserved plant remains (picea needles and charred particles) and hydromorphic features. t5 is a massive clay bed covered by t4 to t1, thin layers of organic silt. 4. summary of the palughetto pollen sequence the palughetto lacustrine-palustrine succession produced chronological data. associations of vegetal macroremains, charcoal particles and pollen enriched the reconstruction of vegetation changes of the italian prealps during the last glacial-interglacial transition (vescovi et al., 2007). the fossil forest originated from trees growing in situ in peat or hanging on the central 55 late glacial tree-ring chronologies from palughetto bog, veneto pre-alps, italy fig. 3 log of the palynologically studied stratigraphic successions on the littoral basin (ple) (after ravazzi & vescovi, 2009, modified). 5. summary of the present-day climate conditions in the cansiglio plateau the today’s climate of the cansiglio plateau is cool -temperate without summer drought. mean annual air temperature at palughetto is 11-12 °c, the january mean is -3 °c, and the july mean is 15 °c (vescovi et al., 2007). mean annual air temperature is 4.9 °c at the meteorologic station of pian cansiglio. the cansigliocavallo ridge represents an important barrier for the warm and humid southern air masses originating from the mediterranean sea basin. in contrast to nearby mediterranean climate, precipitation here is concentrated during autumn and spring. mean annual precipitation is 1700-1900 mm (di anastasio & peresani, 1995). during the winter period the climate is harsh due to cold winds from the northeast. the forest vegetation is dominated by fagus sylvatica and abies alba at altitudes between 800 and 1600m a.s.l., followed at higher elevations by a narrow subalpine picea abies-belt, which forms the timberline at 1700-1800m a.s.l. picea abies is also abundant on the plateau because of historical plantations (hofmann, 1965). pinus mugo-shrubs extend in the subalpine belt and along avalanche tracks. the alpine vegetation is mainly formed by calciphilous sesleria varia-carex sempervirens grasslands, including plants of cold steppe (e.g. linum alpinum), screes (e.g. dryas octopetala), and snow beds (dwarf salix species). 6. recovery, preparation and analysis of the dendrochronological samples infills of previous archaeological excavations were removed by an excavator in a 5x11 m area in may 2006 (fig. 5). horizontal roots of larch and spruce were frequent, but most of the trees were not found ‘in situ’ and to synchronize the horizons of the trees into the existing stratigraphy additional sediment profiles were described (fig. 6). after woody remains were carefully excavated manually, described and documented briefly, we sampled and analysed all remnants of trunks, branches and roots with a minimum number of 10 tree rings (fig. 7). tree-ring analyses of the wood started after the excavation. at the excavation, 203 fossil trees remnants were sampled by cutting disc cross-sections using a chain saw (tab. 1). whether possible, the lowermost disc samples were taken 0.5 m above the root system, to obtain ring-width sequences less prone to any irregularities or eccentricities from root disturbances. samples were then prepared for tree-ring analyses at the treering laboratory in hohenheim. even if the preservation of the wood seemed to be excellent, most of the cellulose appeared decomposed. therefore, we kept the samples saturated with water and froze the wood before surfacing. wood identification was done by microscopic analyses of thin slices of the samples using the identification keys of schweingruber (1990) with special regard on the differentiation of the two conifer species spruce and larch (bartolin, 1979). this is of special importance as both species have very similar wood anatomy, especially when subfossil (schweingruber, 1990). frozen sec 56 fig. 4 the main steps of the environmental history of the palughetto area during the last glacial-interglacial transition: 1, scrub of mountain pine and chamephytes (ca. 16 ky cal bp); 2, forest of picea-larix in the lake surroundings (14.7-14.3 ky cal bp); 3, forest extended at the edge of the bog (14.3-13.0 ky cal bp); 4, forest retreat from the edge of the bog (12.85 ky bp); 5, broad-leaves and conifers mixed forest (11.3 ky bp); 6, broadleaves and conifers mixed forest (10.8 ky bp); (after ravazzi & vescovi, 2009, modified). friedrich m. et al 57 fig. 5 map of the 2006 excavation carried out at palughetto in the archaeological sectors of the 1997 and 2001 excavations. the position of the trenches and of the largest arboreal remains brought to light and sampled are reported (drawn by m. peresani). fig. 6 a: picea trunk. b: various fragments of coniferous trunks. c: one among the largest picea trunks in course of exposition. d: larix trunk repositioned in the bog after sampling. late glacial tree-ring chronologies from palughetto bog, veneto pre-alps, italy 58 tab. 1 catalogue of wooden macroremains at the excavation in 2006 with reference to the trench in the excavated area, species, presence of pith and bark, number of rings, type of sample, diameter and length. (1 2 of 4) friedrich m. et al 59 late glacial tree-ring chronologies from palughetto bog, veneto pre-alps, italy tab. 1 (3 4 of 4) tions of wood were manually surfaced with razor blades for tree-ring analyses, and the surface was then whitened with chalk to obtain a better contrast. annual treering width was measured on the hohenhein tree-ring device at 0.01 mm resolution. for tree-ring cross-dating and statistics we used the tree-ring analyses program tsap (rinn, 1996). multiple radii were measured per each disc, the measurement series obtained per individual tree were then cross-dated visually and screened for missing rings. all tree radii were averaged to form tree mean series, which were subsequently averaged into chronologies. 7. radiocarbon dating and chronology building gram-size samples of tree-ring blocks of a few years were taken for ams-14c-analyses, pre-treated to cellulose, combusted to graphite in heidelberg and measured in the lund ams facility. chronologies were 60 fig. 7 types of wood sampled. tab. 2 14c ages of the trees from palughetto (for reference to the dated sample see table 1). fig. 8 genera of the sampled trees. friedrich m. et al built based on cross-dated tree-ring series. calendar ages of groups of synchronous trees (chronologies) were then obtained by calibrated 14c-ages (tab. 2). we based calibration on the calibration dataset intcal20 (reimer et al., 2020). 8. results and discussion according to our tree finds the forest in the area mainly consisted of the species spruce (picea abies karsten), larch (larix decidua mill.), birch (betula pubescens erh.), poplar (populus spec.) and willow (salix spec.) (fig. 8) confirming results from palynology and botanical remains on the same site (vescovi et al., 2007). the maximum length of the preserved trunks is 5m with diameter of up to 45 cm (tab. 1). the maximum number of tree rings varies between 281 for larch, 147 for spruce, 98 for birch and 74 for poplar (fig. 9). the age distribution shows that mean individual ages of larch trees was twice that of the spruce and birch (fig. 10). mean growth rates are different for each single species. spruce trees show extremely wide rings of up to 6mm per year and show ‘complacent’ tree growth. larch tree rings were much narrower of 1-2 mm per year and with higher interannual variability (fig. 11). the high growth rate indicates that growth of spruce at the site was apparently not limited strongly by climatic factors. the growth rates of the spruces indicate favourable growing conditions such as moderate temperatures and sufficient water supply during the vegetation period, which is comparable to the modern situation in the area. in contrast to spruce, mean growth of larch is much smaller, which shows the better adaptation of spruce to the site conditions, especially the good water supply during the bølling-allerød in palughetto. 8.1. dendrochronology the dendrochronological analysis of the tree-ring series of 203 wooden remnants from the subfossil forest of palughetto, resulted in seven groups of 34 trees, which fall in a period of c. 1600 years of the bøllingallerød interstadial (fig.s 12 and 13). the internal crossdating of this material both visually and statistically was possible due to the strong common signal in the treering series. the common signal of the trees is significantly higher for larch, but lower for spruce. neverthe 61 fig. 9 individual ages of the trees sampled. fig. 10 distribution of individual age of the trees: (a) picea, (b) larix, (c) betula. fig. 11 typical tree growth of the two species larch and spruce. wide rings in spruce, narrow rings in larch. late glacial tree-ring chronologies from palughetto bog, veneto pre-alps, italy 62 <<<<< fig. 12 floating tree-ring chronologies from bølling (pre14,000 bp): (a) spruce trees from 12,500 conv. bp; (b) spruce trees from 12,400 conv. bp; (c) larch trees from 12,350 conv. bp; (d) larch trees from 12,200 conv. bp. fig. 13 floating tree-ring chronologies from allerød (post 14,000 bp): (a) larch trees from 11,760 conv. bp; (b) spruce trees from 11,250 conv. bp; (c) larch trees from 11,000 conv. bp. friedrich m. et al the high spatial coherence offers the opportunities to cross-date tree-ring series in the late glacial over large distances and therefore open the perspective to crossdate the floating tree-ring chronologies from italy to the bølling-allerød pine chronology of central europe (friedrich et al., 2001). 9. conclusion and outlook we have constructed tree-ring chronologies of spruce and larch from palughetto from late glacial (12,500 to 11,000 14c bp) and spanning the entire bølling-allerød chronozone. chronologies are still ‘floating’ but ongoing work on tree-ring chronologies less, cross-dating of all groups could be done with sufficient statistical significance. in this initial work we first focused on the conifer species to construct chronologies, as they show the better common signal, but we also found good correlation between the other species. to anchor the floating tree-ring chronologies in time we used ams radiocarbon measurements on defined treering samples (fig. 14). the earliest group of trees of spruce and larch started to grow in the early bølling chronozone at 14,600 cal bp. the presence of well growing spruce trees in this early period of the late glacial with mean ring width comparable to modern spruce trees on the cansiglio plateau and the relatively low common signal strength suggest that the potential tree-line in the southern alpine region must have been considerably higher than the palughetto mire during the bølling. there are still gaps between the different floating chronologies, but many trees present sufficient number of tree-rings, which could not be matched to one of the chronologies yet, and therefore have the potential to fill the gaps. additionally, more dendrochronological work will be done to cross-date series of the deciduous tree species such as birch, poplar and willow. the possibility of dating late glacial trees by dendrochronology was made possible by the pine tree-ring chronology extensions (kromer et al., 2004; schaub et al., 2008). additionally, several floating segments of tree-ring chronologies from the bølling-allerød interstadial could be combined to a 1,500 years long tree-ring chronology spanning the 14c age-interval between 12,300 to 10,600 14c bp. it is based on pines (pinus sylvestris l.) from sites in germany and switzerland (schaub et al., 2008). our own extensive fieldwork in the po-plain of northern italy and dendrochronological analyses on those samples resulted in a number of ‘floating’ tree-ring chronologies of several hundred years, which could be dated by radiocarbon (kaiser et al., 2012; adolphi et al., 2017). the earliest chronology of pine trees from the po plain started their growth at 12,500 14c bp, indicating that re-forestation during the first warm period of the late glacial (chronozone bølling) in the southern pre-alpine region started several hundred years earlier than in central europe, i.e. pine trees from dättnau, switzerland (kaiser, 1993). the high similarities in some periods of the allerød between the regional tree-ring chronologies of eastern germany, southern germany and switzerland with distances of up to 600 km indicate a higher spatial coherence of meteorological summer conditions during the bølling-allerød compared to the modern situation. 63 fig. 15 overview of late glacial tree-ring chronologies from northern italy from subfossil trees of palughetto and from the po-plain (dark grey) compared to the absolutely dated tree-ring chronologies from germany (friedrich et al., 2004) and the combined floating bølling-allerød chronologies from germany and switzerland (friedrich et al., 2004; kromer et al., 2004; schaub et al., 2008) (light grey) (ppc: preboreal pine chronology; ydpc: younger dryas pine chronology; apc: allerod pine chronology). fig. 14 bar graph of the tree-ring chronologies from palughetto dated by 14c. late glacial tree-ring chronologies from palughetto bog, veneto pre-alps, italy from late glacial subfossil pines from several locations in the po-valley may give the opportunity in the future to combine trees from northern italy and link it to the central european absolute tree-ring chronology (fig. 15). acknowledgements the study of the palughetto basin is part of a wider research project about the peopling of cansiglio plateau during the palaeolithic and mesolithic, co-ordinated by the university of ferrara (m.p.) and supported by azienda regionale per l’innovazione del settore primario veneto agricoltura, comune di farra d’alpago, angelini foundation, banca delle prealpi, c.a.i. gruppo terre alte. this work was founded by the comer science and education foundation and by the european science foundation (euroclimate, project tree-14). we thank w. broecker, g. denton and r. alley for support. we are grateful to edoardo martinetto, university of torino, elisa vescovi, university of bern, cesare ravazzi, national council of research, milano, hans-peter stika and sabine remmele, hohenheim university, and numerous students from universities of hohenheim, turin and milano for their help at the 2006 excavation in palughetto. author contributions: b.k. and m.f. designed research; m.f. and b.k. analyzed primary dendrochronological data; m.f., b.k. and m.p. wrote and edited the manuscript. references adolphi f., muscheler r., friedrich m., güttler d., wacker l., talamo s., kromer b. (2017) radiocarbon calibration uncertainties during the last deglaciation: insights from new floating tree-ring chronologies. quaternary science reviews, 170, 98-108. avigliano r., di anastasio g., improta s., peresani m., ravazzi c. (2000) a new late glacial to early holocene palaeobotanical and archaeological record in the eastern pre-alps: the palughetto basin (cansiglio plateau, italy). journal of quaternary science, 15(8), 789-803. doi: 10.1002/1099-1417(200012)15:8<789::aidjqs556>3.0.co;2-e bartolin t. (1979) the picea-larix problem. iawa (international association of wood anatomists) bulletin, 1, 68-70. bertola s., di anastasio g., peresani m. (1997) hoarding unworked flints within humid microenvironments. new evidence from the mesolithic of the southern alps. préhistoire européenne, 10, 173185. di anastasio g., peresani m. (1995) osservazioni pedostratigrafiche e micromorfologiche sul sito mesolitico di casera lissandri (altopiano del cansiglio). studi trentini di scienze naturali acta geologica, 72, 79-92. friedrich m., kromer b., kaiser k.f., spurk m., hughen k.a., johnsen s.j. (2001) high resolution climate signals in the boelling/alleroed interstadial (greenland interstadial 1) as reflected in european tree-ring chronologies compared to marine varves and ice-core records. quaternary science reviews, 20, 1223-1232. doi: 10.1016/s0277-3791(00)00148-7 friedrich m., remmele s., kromer b., spurk m., hofmann j., hurni j.p., kaiser k.f., küppers m. (2004) the 12.480-year hohenheim oak and pine tree-ring chronology from central europe a unique annual record for radiocarbon calibration and palaeoenvironment reconstructions. radiocarbon, 46, 1111-1122. doi: 10.1017/s003382220003304x friedrich m., kromer b., reichle d., remmele s., peresani m. (2009) dendrocronologie del tardoglaciale dal palughetto. in: peresani m., ravazzi c. (a cura di) le foreste dei cacciatori paleolitici. ambiente e popolamento umano in cansiglio tra tardoglaciale e postglaciale. suppl. bollettino società naturalisti silvia zenari, pordenone, 97119. hofmann a. (1965) piano di assestamento della foresta demaniale del cansiglio. ufficio amministrazione ff.dd. cansiglio, vittorio veneto. kaiser k.f. (1993) beiträge zur klimageschichte vom hochglazial bis ins frühe holozän, rekonstruiert mit jahrringen und molluskenschalen aus verschiedenen vereisungsgebieten. unpublished habilitation thesis, ziegler druckund verlags-ag, winterthur. kaiser k.f, friedrich m., miramont c., kromer b., sgier m., schaub m., boeren i., remmele s., talamo s., guibal f., sivan o. (2012) challenging process to make the lateglacial tree-ring chronologies from europe absolute: an inventory. quaternary science reviews, 36, 78-90. doi:10.1016/j.quascirev.2010.07.009 kromer b., friedrich m., hughen k.a., kaiser k.f., remmele s., schaub m., talamo s. (2004) late glacial 14c ages from a floating, 1382-ring pine chronology. radiocarbon, 46(3), 1203-1209. doi: 10.1017/s0033822200033099 peresani m., bertola s., de stefani m., di anastasio g. (1999-2000) bus de la lum and the epigravettian occupation of the venetian pre-alps during the younger dryas. rivista di scienze preistoriche, l, 103-132. peresani m., astuti p., di anastasio g., di taranto e., duches r., masin i., miolo r. (2011) gli insediamenti epigravettiani e la frequentazione mesolitica attorno al palughetto sull’altopiano del cansiglio (prealpi venete). preistoria alpina, 45, 21-65. reimer p.j., austin w. e.n., bard e., bayliss a., blackwell p.g., et al. (2020) the intcal20 northern hemisphere radiocarbon age calibration curve (0-55 cal kbp). radiocarbon, 62(4), 725757. doi: 10.1017/rdc.2020.41 ravazzi c. (2002) late quaternary history of spruce in southern europe. review of palaeobotany and palynology, 120(1-2), 131-177. ravazzi c., vescovi e. (2009) le testimonianze fossili della riforestazione del cansiglio al termine dell’ultima glaciazione. in: peresani m., ravazzi c. (a 64 friedrich m. et al visentin d., bertola s., ziggiotti s., peresani m. (2016) going off the beaten path? the casera lissandri 17 site and the role of the cansiglio plateau on human ecology during the early sauveterrian in north-eastern italy. quaternary international, 423, 213-229. doi: 10.1016/j.quaint.2015.11.119 cura di) le foreste dei cacciatori paleolitici. ambiente e popolamento umano in cansiglio tra tardoglaciale e postglaciale. suppl. bollettino società naturalisti silvia zenari, pordenone, 65-96. rinn f. (1996) tsap-time series analyses presentation. reference manual (version 3.0). rinntech, heidelberg. schaub m., büntgen u., kaiser k.f., kromer b., talamo s., krogh andersen k., rasmussen s.o. (2008) lateglacial environmental variability from swiss tree rings. quaternary science reviews, 27, 2941. doi: 10.1016/j.quascirev.2007.01.017 schweingruber f.h. (1990) mikroskopische holzanatomie 3. aufl. verlag flück-wirth, ch-teufen, birmensdorf. vescovi e., ravazzi c., arpenti e., finsinger w., pini r., valsecchi v., wick l., ammann b., tinner w. (2007) interactions between climate and vegetation during the lateglacial period as recorded by lake and mire sediment archives in northern italy and southern switzerland. quaternary science reviews, 26, 1650-1669. doi: 10.1016/j.quascirev.2007.03.005 65 late glacial tree-ring chronologies from palughetto bog, veneto pre-alps, italy ms. received: october 5, 2023 revised: february 8, 2024 accepted: february 12, 2024 available online: march 4, 2024 file:///e:/amq%20new/amq%20volumi/amq%2037/ojs%20739%20friedrich%20et%20al/10.1016/j.quaint.2015.11.119 file:///e:/amq%20new/amq%20volumi/amq%2037/ojs%20739%20friedrich%20et%20al/10.1016/j.quascirev.2007.01.017 file:///e:/amq%20new/amq%20volumi/amq%2037/ojs%20739%20friedrich%20et%20al/10.1016/j.quascirev.2007.03.005 66 imp.moretti& effetti dei “miglioramenti fondiari” nelle murge alte (puglia): l'impatto antropico sul paesaggio carsico e costiero massimo moretti1, antonio fiore2, piero pieri1, marcello tropeano3 & salvatore valletta2 1dipartimento di geologia e geofisica, università degli studi di bari – m.morettii@geo.uniba.it 2sigea sezione puglia, bari puglia@sigea.org 3dipartimento di scienze geologiche, università della basilicata, potenza tropeano@unibas.it riassunto: moretti m. et al., effetti dei “miglioramenti fondiari” nelle murge alte (puglia): l’impatto antropico sul paesaggio carsico e costiero. (it issn 0394-3356, 2004). l'area delle murge rappresenta un territorio carsico ricco di zone d'interesse ambientale e nella quale sono in corso di istituzione due importanti parchi (parco nazionale dell’alta murgia e parco regionale delle gravine). negli ultimi decenni esso è stato soggetto a profondi mutamenti legati all'azione antropica. fra questi viene qui analizzato quello legato all'introduzione di particolari operazioni di "miglioramento fondiario". tali operazioni, definite genericamente come "spietramento", consistono nello scarificare e triturare meccanicamente la porzione sommitale del substrato roccioso calcareo in aree dove i suoli sono assenti o caratterizzati da spessori modesti. mediante tali operazioni si riesce quindi ad ottenere in superficie un sufficiente spessore di suolo dotato di scarsa coesione che permette la messa a coltura di aree caratterizzate da una bassa vocazione agricola e tradizionalmente adibite a pascolo. il presente lavoro è incentrato sullo studio degli effetti di queste pratiche sistematorie sull’ambiente carsico e costiero delle murge. abstract: moretti m. et al., the effects of “soil improvement” operations in the murge alte area (southern italy): the impact on the karstic and coastal landscape. (it issn 0394-3356, 2004). the murge area (puglia, southern italy) is a morpho-structural high which is located in the intermediate sector of the emerged apulian foreland. the higher part of the murge area (murge alte sector) is characterized both by the absence of post-cretaceous marine deposits and by a mature karstic landscape. the soils in the murge alte region are the result of a series of complex pedogenetic processes that started on the residual products of cretaceous limestones. these soils tendentially have a clayey granulometric composition with an high content in fragments and blocks of limestones: often they are shallow, less than 20 cm, originating from the emerging calcareous rocks. historically, in this area, the presence of thin soils and the scarsity of water prevented a massive development of agricultural activities and, typicallly it was mainly a grazing land. nevertheless, recently (last 20 years) the action of public financing (mainly ue founds) has promoted the introduction of soil improvement operations. these operations are characterised by massive ploughing and crushing of the carbonate bedrock and have induced some important effects both in the karstic landscape and in the hydrogeological balance. this paper is focused on the analysis of these effects both in the higher and coastal zones of the murge area. in particular, in a very short period of time (only 20 years), the analysed soil improvement operations have produced the following irremediable effects: the breaking up of the soil-rocky substratum complex; alteration of the granulometric range size of the soil (massive increase in finer particles); increase in soil loss; alteration of the superficial and deep karstic system; increase in flood risk. parole chiave: impatto antropico, uso del suolo, aree carsiche e costiere, murge, italia meridionale. keywords: human impact, land use, coastal and karstic area, murge, southern italy. il quaternario italian journal of quaternary sciences 17(2/1), 2004, 323-330 1. introduzione l'altopiano carsico delle murge alte nord-occidentali (fig. 1) è stato inserito come "area di reperimento" nella l. 394/91 (legge quadro sulle aree protette) e proposto per l'istituzione quale parco nazionale dell'alta murgia con la conferenza dei servizi promossa dalla regione puglia nel novembre 1993. comunque, tutta l'area perimetrata dal parco nazionale dell'alta murgia è già sottoposta a vincolo idrogeologico ed è zona di tutela del piano regionale risanamento della acque (p.r.a.), oltre che già ricompresa nel proposto sito di importanza comunitaria (psic) nonchè zona di protezione speciale (zps) “murgia alta”. nella stessa area sono presenti numerosi elementi d'interesse storico (fra tutti si cita castel del monte) mentre, sotto il profilo paesaggistico, gli aspetti geomorfologici connessi al carsismo ed alla evoluzione neogenica di questo territorio rappresentano i principali punti di interesse naturalistico. la presenza di campi carreggiati, di doline con dimensione ed origine differenti (le più spettacolari e conosciute sono quelle del “pulo” e del “pulicchio” nell’area compresa fra altamura e gravina), di numerose “gravine” (strette forre di origine fluviale profonde anche fino a 100 m e connesse al sollevamento medio-suprapleistocenico dell’area) e di numerose cavità carsiche rende quest’area di indubbio interesse anche dal punto di vista scientifico. nell’area del parco ricadono anche la famosa grotta carsica di lamalunga (nella quale è stato rinvenuto “l’uomo di altamura”) e la cava con le celeberrime tracce di locomozione di dinosauri (cava ex-de lucia in località pontrelli – iannone, 2003). negli ultimi 20 anni l’area delle murge alte è stata soggetta a profondi mutamenti connessi all’azione antropica rappresentata soprattutto da una generalizzata azione di “miglioramento fondiario” (giglio et al., 1996): le pratiche utilizzate (soprattutto “spietramento” s.l.), in combinazione con l’introduzione di coltivazioni a 324 m. moretti et al., fig. 1. a carta geologica schematica delle murge (da pieri et al., 1997 modificata). b: sezione geologica schematica attraverso l’altopiano delle murge (da pieri et al., 1997 modificata). c: carta schematica della distribuzione delle paleolinee di costa dei terrazzi marini del pleistocene medio-superiore (da ciaranfi et al., 1988 modificata). a: simplified geologic map of the murge area (modified from pieri et al., 1997). b: simplified geologic section along the murge area (modified from pieri et al., 1997). c: map of the coastlines of the marine terraced deposits (middle-late pleistocene modified from ciaranfi et al., 1988). carattere più o meno intensivo, accelerano irrimediabilmente i processi erosivi ad opera delle acque meteoriche e del vento (pieri et al., 1999). gli effetti di tali pratiche non sono ristretti alla sola area delle murge alte, ma si risentono, con intensità e modalità differenti, anche nell’adiacente settore costiero pugliese (moretti, 1998; moretti et al., 1998). nel corso degli anni le aree soggette a “miglioramento fondiario” sono via via andate aumentando; allo scopo di quantificarle in modo accurato, sono state messe a punto alcune procedure di calcolo automatico di aree attraverso fotointerpretazione di immagini da satellite (fiore et al., 1995; ekuakille et al., 2000). una forte politica di sovvenzioni pubbliche (programmi integrati mediterranei della comunità europea e l.r. 51/81) ha consentito di estendere la pratica dello spietramento s.l., trasformando in terreni agricoli gran parte dell'area precedentemente destinata a pascolo (aa.vv., 2002). in questo studio si cercherà di evidenziare la stretta relazione fra uso del suolo ed erosione nell’area delle murge con particolare riferimento alle forme diffuse di dissesto idrogeologico s.l. che si registrano nell’ultimo decennio sia nei settori interni e carsici delle murge (murge alte) che nei settori costieri (costa adriatica e ionica delle murge). 2. inquadramento geologico l’avampaese apulo rappresenta il settore di avampaese del sistema orogenico dell’appennino meridionale nel plio-pleistocene (d’argenio et al., 1973). l’avampaese apulo emerso è costituito da tre settori di alto strutturale relativo (rispettivamente, da n a s, gargano, murge e salento) separati da zone di faglia orientate all’incirca e-o. le murge (fig. 1a e b) rappresentano i l settore di alto relativo intermedio dell’avampaese apulo emerso limitato a nord dal graben dell’ofanto e a sud dalla soglia messapica (pieri, 1980; iannone & pieri, 1982; ricchetti et al., 1988). a partire dal pliocene, l’evoluzione geodinamica e stratigrafica di questo settore dell’avampaese apulo è strettamente controllata dalla migrazione verso e del sistema orogenico appenninico e dalla conseguente fase di subsidenza che porta al progressivo annegamento di estesi settori di alto strutturale (doglioni et al., 1994; pieri et al., 1997): durante tale fase di subsidenza sedimentano le formazioni della calcarenite di gravina e delle argille subappennine (pliocene superiorepleistocene inferiore ciaranfi et al. 1988) che affiorano con spessori e caratteri stratigrafici molto variabili lungo i bordi e nei settori morfologicamente meno elevati delle murge (fig. 1.a e 1.b). dalla fine del pleistocene inferiore fino all’attuale, l’avampaese apulo è soggetto ad un intenso sollevamento (interpretato in letteratura in modi assai differenti – ricchetti et al., 1988; doglioni et al., 1994; de alteriis, 1995; gambini & tozzi, 1996). in questo intervallo temporale sedimentano i depositi regressivi della fossa bradanica (pleistocene inferiore) ed i depositi marini terrazzati (pleistocene medio-superiore) che segnano la graduale riemersione delle murge (fig. 1.b) lungo il versante ofantino, bradanico, ionico ed adriatico (ciaranfi et al., 1988). l’altopiano delle murge alte, posto oltre i 500 m di quota (fig. 1.b) non è stato quindi interessato dall’in325effetti dei “miglioramenti fondiari” ... gressione plio-pleistocenica: è caratterizzato da estesi affioramenti di calcari mesozoici che, a partire dalla loro emersione avvenuta nel cretaceo superiore, hanno subito intensi fenomeni carsici non obliterati dalla successiva azione erosiva marina. a quote meno elevate (da 500 m s.l.m. fino al livello del mare attuale), alla morfologia carsica si sono sovrapposti gli effetti dell’ingressione marina plio-pleistocenica e della successiva fase di sollevamento regionale che ha portato alla formazione di 16 ordini di terrazzi marini posti via via a quote decrescenti (fig. 1.c ciaranfi et al., 1988). le murge vengono suddivise in murge alte e murge basse proprio in base al livello massimo raggiunto dal mare nell’ingressione plio-pleistocenica che grande influenza ha avuto nell’evoluzione del paesaggio. anche i suoli (oggetto del prossimo paragrafo) sviluppatisi nei due differenti settori delle murge presentano differenze che richiamano tale diversa evoluzione plio-quaternaria. 3. principali caratteri geo-pedologici e generalità sull’uso del suolo i suoli delle murge alte rappresentano il risultato di un insieme complesso di processi pedogenetici che si sono instaurati sui prodotti residuali della dissoluzione dei calcari mesozoici. essi presentano una composizione granulometrica tendenzialmente argillosa con scheletro abbondante costituito da frammenti di rocce calcaree con dimensioni molto variabili. si tratta di "litosuoli" con spessori esigui originatisi su calcari quasi affioranti (fig. 2), costituiti da un solo orizzonte omogeneo (spesso eccezionalmente 30-40 cm) risultante dalla mescolanza di humus, materiale argilloso ed abbondanti frammenti litici calcarei. suoli con spessori maggiori ed accenni di stratificazione in orizzonti si rinvengono solo in aree ristrette, in pratica solo sul fondo delle depressioni carsiche e delle incisioni fluviali, localmente denominate “lame”. la struttura dei litosuoli delle murge alte è spesso grumosa, con humus generalmente abbondante (talvolta superiore al 10%); risultano essere tendenzialmente aridi poiché le acque meteoriche si infiltrano rapidamente nel substrato rappresentato dai calcari permeabili per fratturazione e carsismo. i suoli delle murge basse presentano spessori maggiori e sono spesso formati da più orizzonti. si sono sviluppati sia sui calcari cretacei che sulle unità più recenti, rappresentate dalla calcarenite di gravina, depositi marini terrazzati e, più raramente, depositi continentali di tipo alluvionale o cineritico: si tratta generalmente di suoli di tipo “rendzina”. fig. 2 profilo di un tipico litosuolo delle murge alte. si noti la presenza di un abbondante scheletro calcareo e del substrato roccioso quasi affiorante. typical soil profile in the murge alte area. note the presence of abundant calcareous rock fragments in the soil and the outcropping bedrock. 326 ii territorio delle murge alte, ed in particolare delle murge nord occidentali, fino a pochi decenni fa, era utilizzato esclusivamente a pascolo. la mancanza di spessori adeguati di suolo, la massiccia presenza di scheletro calcareo e la cronica mancanza d’acqua nelle aree considerate (sia per la mancanza di precipitazioni che per l’elevata percentuale di acqua di infiltrazione tipica di un territorio carsico maturo) hanno storicamente e socialmente determinato una vocazione sostanzialmente legata all’allevamento di ovini e subordinatamente bovini ed equini. le coltivazioni erano limitate alle sole aree nelle quali lo spessore del suolo ne permetteva lo sfruttamento senza particolari lavorazioni (depressioni tettoniche, doline, fondi delle “lame”). in queste aree manualmente si allontanavano i clasti calcarei che venivano in seguito utilizzati nella costruzione di muretti a secco o, su lievi pendii, per dar vita ai caratteristici terrazzamenti in pietra sbozzata (nicod, 1992). nelle murge basse invece l’agricoltura è ben sviluppata (generalmente non si tratta di colture intensive, ma in gran prevalenza solo di viti, ulivi e mandorli) grazie alla presenza di apprezzabili spessori di suolo ed alla presenza sia di falde superficiali libere che una relativa bassa profondità della falda carsica. 4. i “miglioramenti fondiari”: uso del suolo ed erosione nelle murge alte a partire dagli anni ’80 sono state introdotte imponenti sistemazioni agrarie meccanizzate (figg. 3 e 4), incentivate da diversi finanziamenti pubblici. il “miglioramento fondiario” consiste principalmente nell’eliminazione dello scheletro calcareo. per questo scopo sono state ideate macchine dotate di “scarificatori” in grado di staccare interi blocchi di calcare dal substrato roccioso e “frantumatori” in grado di operare la “frangitura” delle pietre in campo (figg. 3 e 4). gli estesi interventi di "spietramento" e "frantumazione" meccanica (fino alla polverizzazione) del complesso suolo-roccia calcarea affiorante nelle murge alte sono oggi estesi a gran parte dei terreni precedentemente destinati a pascolo (fig. 5a). lo spietramento e la frantumazione sono operazioni dirette sia a migliorare la costituzione granulometrica del terreno che a favorire l'accessibilità del campo alle macchine da lavoro. lo spietramento consiste nell'eliminazione dello scheletro calcareo e viene maggiormente utilizzato nelle aree in cui lo spessore del suolo è dell'ordine del mezzo metro; per spessori più esigui, l'eliminazione dello scheletro calcareo porta ad una diminuzione del volume di suolo sfruttabile, non compatibile con alcuna coltura. in queste aree si preferisce far ricorso ad interventi di frantumazione che, conservando immutato il volume di suolo, elimina, triturandola, la frazione più grossolana (figg. 5b e c), costituita dai frammenti calcarei. il terreno risultante presenta maggiore lavorabilità, una costituzione granulometrica arricchita in particelle fini (fino al 50% in più, dopo il settimo passaggio della macchina frangipietre) e una migliore capacità idrica (cioè una migliore capacità di trattenere acqua), per l'aumento dei pori di minori dimensioni. le tecniche di miglioramento fondiario descritte hanno però effetti immediati anche sull'entità dell'azione erosiva: il terreno perde la struttura grumosa primaria ed acquista un nuovo costituente (con granulometria variabile a seconda della macchina utilizzata e del numero di passaggi) che, a tutti gli effetti, si comporta da "inerte". la coesione all'interno del suolo e fra il suolo ed il substrato risulta drasticamente diminuita, specie se gli attrezzi utilizzati regolarizzano la morfologia del tetto del substrato, staccandone piccole parti. anche il tipo di coltura può influenzare in modo importante l'azione erosiva delle acque meteoriche: colture come il grano duro (anch’esso introdotto in modo intensivo solo negli ultimi venti anni) infatti accentuano la naturale predisposizione di queste aree alla perdita di suolo. dalla semina (ottobre-novembre) alla mietitura (giugno-luglio) il suolo può considerarsi coperto parzialmente per soli due mesi. da luglio fino alla germinazione della nuova semina il terreno è nudo e soggetto a fig. 4 operazioni di frangitura nelle murge alte. si noti la trasformazione dei blocchi calcarei frammisti a suolo in un aggregato finissimo polverulento. crushing operations in the murge alte area. note the mechanical reduction of the grain size. fig. 3 operazioni di frangitura nelle murge alte. lo scheletro calcareo ed i frammenti di substrato presenti nel campo vengono triturati meccanicamente. crushing operations in the murge alte area. rock fragments and pieces of the calcareous bedrock are mechanically destroyed. m. moretti et al., 327 saturare più facilmente il suolo nei mesi di siccità. l’effetto principale di queste tecniche di miglioramento è quello connesso al drastico aumento dell’aliquota di acqua di ruscellamento superficiale a scapito di quella legata all’infiltrazione. studi recenti sono stati mirati alla valutazione quantitativa di questo processo (spilotro, 2003), ma senza dubbio, dal punto di vista qualitativo, esso determina l’aumento dell’erosione areale e lineare e la perdita di suolo soprattutto nelle aree delle murge alte dove le pendenze sono più marcate. trattando l’argomento in modo più generale, i fattori che rappresentano "cause predisponenti" per il fenomeno dell'erosione del suolo possono essere così riassunti: 1) condizioni geolitologiche e idrologiche; 2) caratteristiche pedologiche; 3) condizioni morfologiche (pendenza, esposizione, quota); 4) "aggressività" del clima locale; 5) copertura vegetale; 6) tecniche di sistemazione. i primi quattro punti dovevano rappresentare, come visto, per l'area delle murge alte un grosso ostacolo allo sviluppo di una agricoltura moderna e costituiscono al tempo stesso gli elementi che spiegano la naturale predisposizione dei suoli murgiani all'erosione. i due ultimi fattori sono gli unici sui quali l'azione antropica si esplica direttamente e che paradossalmente sono stati utilizzati per accelerare irrimediabilmente i processi erosivi. 5. forme di dissesto idrogeologico dell’ambiente carsico e costiero gli effetti delle pratiche sistematorie descritte e del nuovo uso del suolo hanno condotto a rapidi mutamenti anche nel paesaggio carsico. in particolare, osservazioni recenti condotte in numerose aree delle murge, mostrano che gli effetti più evidenti di tali pratiche sono connessi all'instaurarsi di fenomeni diffusi di dissesto idrogeologico. esempi di dissesto idrogeologico e di rapido mutamento della morfologia carsica sono segnalati all'interno delle depressioni carsiche delle murge alte. la dolina del "pulo" di altamura rappresenta l’elemento carsico più spettacolare e conosciuto dell’area delle murge alte (fig. 6). nel suo intorno, nel corso degli ultimi decenni, gli interventi di spietramento e la messa a coltura dei suoli (fig. 6) hanno parzialmente obliterato i naturali canali di deflusso dell’acqua superficiale e compromesso in modo importante i rapporti fra la percentuale dell’acqua di ruscellamento superficiale e le aliquote di evapotraspirazione ed infiltrazione. in seguito alle precipitazioni autunnali dello scorso anno si è prodotta una estesa conoide alluvionale (fig. 7) nella quale è possibile distinguere i subambienti di conoide prossimale e distale (figg. 8 e 9). la porzione distale, caratterizzata da depositi finissimi siltosi ha occluso l’inghiottitoio carsico della dolina. l’acqua piovana sosta per mesi sul fondo del pulo di altamura originando uno stagno-palude. i cambiamenti dell'uso del suolo (grano al posto del pascolo – fig. 6) e gli interventi di spietramento nelle aree circostanti sono le principali cause predisponenti per l'instaurarsi di questo tipo di dissesto. ancor più gravi dal punto di vista paesaggistico ed economico sono stati gli effetti degli eventi alluvionali nelle aree carsiche e costiere delle province di bari fig. 5 murge alte: a. foto delle differenze macroscopiche fra il suolo adibito a pascolo (a sinistra) ed il terreno “spietrato” (a destra); b. particolare della foto 5a, si noti la presenza del substrato calcareo quasi affiorante; c. particolare della foto 5a, si noti la riduzione di granulometria dello scheletro calcareo dopo un solo passaggio della macchina frangipietre. murge alte area: a. photo showing the differences between the grazing soil (on the left) and the “crushed” soil (on the right); b. a close up of the photo 5.a, in the “natural” soil, calcareous bedrock is outcropping; c. a close up of photo 5.a, note the grain size reduction of the calcareous fragments after an only one passage of the crushing machine. forte erosione a causa dei brevi e violenti temporali estivi e del primo autunno. inoltre dopo la mietitura i terreni vengono "preparati" a questa forte fase erosiva attraverso la profonda aratura che viene effettuata per far effetti dei “miglioramenti fondiari” ... 328 e taranto. negli ultimi dieci-quindici anni, sul litorale adriatico delle murge è chiaramente aumentato il trasporto solido dei corsi d’acqua effimeri (“lame”): essi danno vita negli ultimi anni ad insoliti eventi di piena lungo il litorale adriatico delle murge caratterizzati da elevata energia e trasporto di terra rossa che colora il mare per giorni. alluvionamenti ed allagamenti sono diventati negli ultimi anni nella provincia di bari una nuova ed inaspettata emergenza ambientale (moretti, 1998; moretti et al., 1998). la provincia di taranto è stata recentemente interessata da eventi alluvionali di elevata energia che hanno provocato ingenti danni economici. nell'area di massafra la "gravina" è stata alluvionata da ingenti spessori di sedimenti finissimi provenienti dalle aree "spietrate" poste a monte della cittadina (fig. 10). più a valle (area di palagiano), lo stesso evento alluvionale ha prodotto danni ingenti alle coltivazioni e alle vie di comunicazione (fig. 11). i dissesti descritti se, da una parte non presentano certo i caratteri delle calamità naturali che caratterizzano molti settori della nostra penisola, dall’altra rapfig. 8 un particolare di fig.7 nel settore prossimale ghiaioso della conoide alluvionale. a detail of fig. 7 in the proximal gravelly part of the alluvial fan. fig. 9 un particolare di fig.7 nel settore distale siltoso della conoide alluvionale. a detail of fig. 7 in the distal silty part of the alluvial fan. fig. 7 l’estesa conoide alluvionale recentamente formatasi all’interno del pulo d’altamura. the large alluvial fan in the internal part of the “pulo d’altamura” doline. fig. 6 foto area della dolina del pulo di altamura. le aree circostanti sono state trasformate da aree di pascolo a terreni spietrati e campi di grano. aerial view of the “pulo d’altamura” doline. land use in the surrounding area is restricted to crushed soils and cornfields. m. moretti et al., presentano un segno inequivocabile degli effetti delle sistemazioni agrarie sul paesaggio carsico e costiero di queste aree. 6. conclusioni i l complesso degli effetti osservati (erosione accellerata e dissesto idrogeologico l.s.) è direttamente connesso agli interventi di "miglioramento fondiario”, che, nel giro di appena due decenni, hanno irrimedialmente prodotto i seguenti effetti: 1) distruzione del complesso suolo-roccia a seguito delle operazioni di scarificazione, spietramento e frantumazione; 2) produzione di grandi quantità di particelle fini nello scheletro del neo-suolo artificiale, frazioni fini dotate di scarsa o nulla coesione che possono essere facilmente trasportate dagli agenti atmosferici (vento e pioggia); 3) aumento dell'erosione del 329 fig. 11. dettaglio dei danni prodotti nell’area di palagiano durante lo stesso evento alluvionale di fig. 10. detail of damages produced in the coastal palagiano area during the same flood event of fig 10. fig. 10. foto area della gravina di massafra. si noti la presenza dei depositi alluvionali siltosi formati durante l’ultimo evento alluvionale (autunno 2003). aerial view of the gravina di massafra river. note the presence of the thick silty alluvium deposits sedimented during last flood event (autumn 2003). effetti dei “miglioramenti fondiari” ... suolo; 4) distruzione del paesaggio carsico superficiale (lame, doline, campi carreggiati, ecc.) e alterazione del sistema carsico sotterraneo (ipogeo); 5) diminuzione delle quantità d'acqua d'infiltrazione, aumento dell'acqua di ruscellamento superficiale ed alterazione dei processi di ricarica della falda carsica. il danno ambientale prodotto non riguarda purtroppo quindi solo gli aspetti connessi al paesaggio carsico (che doveva essere nelle intenzioni la principale attrattiva del neonato parco nazionale dell’alta murgia) delle murge alte, ma nel giro di pochi anni ha coinvolto le adiacenti aree costiere determinando localmente anche ingenti danni economici. la comunità scientifica per anni si è divisa sugli effetti reali di queste pratiche (una contrapposizione che in termini semplicistici potremmo schematizzare come geologi contro agronomi); oggi, che gli interventi di “miglioramento fondiario” sono ormai estesi a gran parte dell’originaria area adibita a pascolo (aa. vv., 2003), il danno ambientale si è ormai irrimediabilmente prodotto: gli sforzi della ricerca dovranno essere quindi orientati in futuro all’individuazione di soluzioni tecniche volte alla rinaturalizzazione delle aree spietrate e/o a mitigare gli effetti dell’erosione diffusa e concentrata. inoltre tale approccio dovà tener conto forzatamente degli altri impatti antropici ringraziamenti desideriamo ringraziare un anonimo referee per la revisione critica del manoscritto. un sentito ringraziamento va al centro altamurano ricerche speleologiche per averci fornito informazioni e materiale fotografico sul pulo d’altamura. questo lavoro è stato eseguito con finanziamenti m.i.u.r. 2001, 2002 e 2003 (resp. l. sabato) e cofin 2002 (resp. naz. l. simone, resp. locale a. laviano). bibliografia aa. vv. (2002) studi per il piano di area dell’alta murgia rapporto finale . 515 pp. volume speciale a cura del politecnico di bari, dipartimento di architettura e urbanistica dipartimento di architettura e urbanistica, regione puglia e provincia di bari. ciaranfi n., pieri p. & ricchetti g. (1988) note alla carta geologica delle murge e del salento (puglia centromeridionale). mem. soc. geol. it., 41, 449-460. d’argenio b. (1974) le piattaforme carbonatiche periadriatiche. una rassegna di problemi nel quadro geodinamico mesozoico dell’area mediterranea. mem. soc. geol. it., 13, 137-159. de alteriis g. (1995) different foreland basins in italy. examples from the central and southern adriatic sea. tectonophysics, 252, 349-373. doglioni c., mongelli f. & pieri p. (1994) the puglia uplift (se italy): an anomaly in the foreland of the apenninic subduction due to buckling of a thick continental lithosphere. tectonics, 13, 5,1309-1321. ekuakil le, a. l., moretti m., pieri p., trall i f., & tropeano, m. (2000) spectral characterization of soil by using ers-2/sar satellite images. gndci 2012, mediterranean storms (ed. claps & siccardi), 615-626. fiore a., loizzo r., moretti m., pappalepore m. & tropeano m. (1995) il telerilevamento da satellite per l'osservazione dello "spietramento" nelle aree carsiche delle murge. applicazione su un'area campione (murgia materana). telerilevamento g.i.s. e cartografia al servizio dell'informazione territoriale. atti del vii conv. naz. ass. it. di telerilevamento, 373-381. chieri (to) 17-20 ottobre 1995. gambini r. & tozzi m. (1996) tertiary geodynamic evolution of southern adria microplate. terra nova, 8, 593-602. giglio g., moretti m. & tropeano m. (1996) rapporto fra uso del suolo ed erosione nelle murge alte: effetti del miglioramento fondiario. geologia applicata ed idrogeologia, xxxi, 179-185. iannone a. (2003) facies analysis of upper cretaceous peritidal limestones characterized by the presence of dinosaur tracks (altamura, southern italy). mem. sci. geol., 55, 1-12. iannone a. & pieri p. (1982) caratteri neotettonici delle murge. geol. appl. e idrogeol., xvii, 147-159. moretti m. (1998) le alluvioni e gli allagamenti nell'area urbana di bari: cenni storici e strumenti per una corretta gestione del territorio costiero murgiano. agriambiente, 11/98, 16-17 moretti m., paglionico a. & santoro o. (1998) analisi dei disequil ibri geoambientali nel "sistema urbano" di bari: un'area metropolitana inserita in un territorio carsico e costiero. "geologia delle grandi aree urbane", progetto strategico cnr, 197-201. nicod j. (1992) muretti e terrazze di coltura nelle regioni carsiche mediterranee. itinerari speleologici, serie ii, n° 6, 9-18, 1992. pieri p. (1980) principali caratteri geologici e morfologici delle murge. murgia sotterranea, boll. speleo. martinese, ii/2,13-19. pieri p., festa v., moretti m. & tropeano m. (1997) quaternary tectonic activity of the murge area (apulian foreland, southern italy). annali di geofisica, xl/5, 1395-1404. pieri p., giglio g. moretti m., tralli f., tropeano e. & tropeano m. (1999) pratiche di spietramento e impoverimento dei suoli in aree carsiche: il caso delle murge alte. ii forum internazionale sulla desertificazione: azioni italiane a sostegno della convenzione delle nazioni unite per combattere la desertificazione. 243-246 e 217-220 nella versione in inglese. ricchetti g., ciaranfi n., luperto sinni e., mongelli f. & pieri p. (1988) geodinamica ed evoluzione sedimentaria e tettonica dell'avampaese apulo. mem. soc. geol. it., 41, 57-82. spilotro g. (2003) modificazioni antropiche delle tessiture dei suoli carsici dell’alta murgia e finalizzazione agricola: implicazioni idrogeologiche. riassunti fist, bellaria 2003. 330 ms. ricevuto l’11 maggio 2004 testo definitivo ricevuto il 16 novembre 2004 ms. received: may 11, 2004 final text received: november 16, 2004. m. moretti et al., l'uso di modelli digitali del terreno come strumento per lo studio dell'evoluzione morfologica dei corsi d'acqua: proposte metodologiche e primi risultati giorgio lollino1, daniele giordan1, marco baldo1, paolo allasia1 & federica pellegrini2 1cnr irpi, strada delle cacce 73, 10135 torino, tel 011/3977810 2aipo, via garibaldi 75 43100 parma e-mail: giorgio.lollino@irpi.cnr.it riassunto: lollino g. et al., l'uso di modelli digitali del terreno come strumento per lo studio dell'evoluzione morfologica dei corsi d'acqua: proposte metodologiche e primi risultati (it issn 0394-3356, 2008). la disponibilità di strumentazioni per il rilevamento su vaste aree come il lidar offre, forse per la prima volta, la possibilità di realizzare modelli digitali del terreno (dtm) ad alta risoluzione (2 8 punti al metro quadrato) di ampie porzioni di territorio tra cui anche i fiumi. l'elevata complessità morfologica dei corsi d'acqua e la necessità di rilevare anche le porzioni sommerse, rende tale contesto particolarmente complesso. l'uso esclusivo del lidar non è infatti spesso sufficiente per ottenere un dtm completo e devono quindi essere ad esso abbinati altri sistemi di rilevamento delle porzioni sommerse. come per tutte le strumentazioni relativamente recenti, anche in questo caso non esistono ancora delle modalità di rilevamento standard; esiste dunque forse la necessità, a fronte di progetti di ampia portata, di provare a definire delle possibili combinazioni di più metodi di rilevamento che si adattino alla differenti situazioni riscontrabili alla scala, per esempio, del bacino padano. l'esperienza condotta dal cnr irpi di torino in tale ambito ha permesso sin ora di riconoscere una possibile relazione tra tipologia di corso d'acqua e modalità di rilevamento. tale ipotesi, ancora sperimentale, è comunque il frutto di un’esperienza pluriennale nel campo del rilevamento dei corsi d'acqua con tali tecniche, ma anche dell'impiego di tale tipologia di dati per lo studio dell'evoluzione morfologica. generato il dtm ad una specifica maglia (la cui densità di punti idonea a rappresentare fedelmente le discontinuità morfologiche del territorio è anch'essa oggetto di ricerca) sono infatti possibili diverse applicazioni: dalle più semplici come l'estrazione di sezioni topografiche alle più complesse, che prevedono la comparazione di modelli digitali realizzati in tempi diversi sui medesimi tratti di alveo. l'obiettivo di tale comparazione è quello di riconoscere e misurare le variazioni occorse, attraverso la creazione di una metodologia di gestione e trattamento dei dati che presuppone specifiche conoscenze sia in campo topografico che geomorfologico. il processo di comparazione proposto non è infatti un mero esercizio informatico, ma un percorso basato su una serie di tappe alle quali seguono necessariamente un controllo ed una validazione su basi geomorfologiche attraverso l'impiego di ortofoto digitali rilevate contestualmente al volo lidar. i risultati sin ora raggiunti con questa tecnica sperimentale riguardano sia la possibilità di valutare in modo continuo le variazioni altimetriche occorse che il calcolo delle variazioni volumetriche del medesimo periodo. in questo modo è forse possibile affiancare agli studi condotti su sezioni topografiche, un nuovo approccio di tipo areale (attraverso dei grigliati con passo di 1 m2) che prende in considerazione con continuità l'intero corso d'acqua. alla luce dei risultati raggiunti ed in parte esposti, tale metodologia sembra essere in grado di evidenziare le variazioni recenti di un corso d'acqua con un grado di dettaglio estremamente elevato e di creare un nuovo metodo di studio da abbinare a quelli già comunemente utilizzati dalla comunità scientifica. l'utilizzo poi di sistemi informativi territoriali, consente anche di creare un'unica base di dati in cui, tenendo conto delle enormi differenze in termini di precisioni, possono essere inseriti i dati provenienti dalle cartografie storiche, a fianco delle variazioni volumetriche occorse negli ultimi 3-4 anni; l'obiettivo è quello di per poter alla fine ottenere un quadro il più possibile esaustivo di tutte le informazioni disponibili, in un’ottica di analisi multidisciplinare del contesto fluviale. l'oggetto della ricerca non riguarda tuttavia solamente la definizione della metodologia di comparazione dei dtm, ma prende in considerazione anche le modalità stesse con cui essi vengono generati: la necessità di affiancare al lidar altre strumentazioni finalizzate ai rilevamenti delle aree sommerse (single beam, multibeam, side scan sonar) ha innescato una profonda riflessione circa la necessità di definire delle linee giuda che mettano in relazione le tipologie di rilevamento con le caratteristiche morfologiche dei corsi d'acqua analizzati. abstract: lollino g. et al., dtms comparison methodology as a tool for studying morphological river evolution (it issn 0394-3356, 2008). the availability of new instruments for large area survey activities such as lidar gives, perhaps for the first time, the possibility to make digital terrain model (dtm) of rivers and other geomorphological contexts. the high geomorphological complexity of rivers and the necessity to also carry out surveys of the submerged zone, make this context very complex. for this reason the exclusive lidar use is not always enough and often the use of other survey instrumentation is necessary to obtain a high resolution (2 8 point per meter) river dtm. as for other recent instrumentation, also for lidar standard survey methodology is still not available. from this point of view, there is probably the necessity to try to define possible relationships between survey methods and morphological river characteristics, for example, at po basin scale. the experience conducted by the cnr irpi of turin in this field has so far allowed us to recognize a possible relationship between river morphology and surveying methods. such a hypothesis, until now experimental, has been made due to years of experience in the field of stream surveying using such techniques and this data typology. when a dtm is calculated, it is then in fact possible to use different applications: starting from the more simple such as topographical river section extraction, to arrive at the most complex, such as a digital model comparison carried out at different times on the same river bed areas. the goal of such comparisons is to recognize and measure variations which occurred, through the creation of a management and treatment data methodology that implies specific knowledge in both topographical and in the geomorphologic field. the comparison process here proposed is not in fact a simple computational exercise but a path based on a series of steps where a control and validation from a geomorphologic point of view, through a digital ortophoto analysis, is taken during the lidar survey. in this way it is maybe possible to place along side the studies conducted using topographical sections, a new areal approach (through regular grids with a footstep of 1m2), that takes into consideration the whole river bed. in the light of collected results and partly shown, such methodology seems to be able to underline recent variations of a water course with an high degree of reliability and to create a new study methodology to commonly combine those already used by the scientific community. the use of geographic information systems, thus, also allows us to create an unambiguous database in which, keeping in mind the enormous differences, data coming from the historical cartographies, with the variations which occurred in the last 3-4 years, can be imputed; the final goal is to create a more exhaustive scenery using all the available information from a multidisciplinary analysis point of view of a river domain. the aim of this research is not only to define the dtm comparison methodology, but also to evaluate the best way to do them: the necessity to use not only the lidar but also some instrumentation to carry out the dtm of submerged areas (single beam, multibeam, side scan sonar) required the possibility to define a survey methodology that assigns the relationship between river morphology and survey activity parole chiave: corso d'acqua, dtm, lidar, evoluzione morfologica del corso d'acqua. keywords: river, dtm, lidar, river bed morphological evolution. il quaternario italian journal of quaternary sciences 21(1b), 2008 331-342 332 g. lollino et al. 1. introduzione lo studio dell'evoluzione dei corsi d'acqua rappresenta un tema di ricerca da sempre molto interessante per le molteplici ripercussioni che esso ha sia da un punto di vista scientifico, ma anche rispetto alla complessa opera di gestione del territorio. per quanto riguarda in special modo il secondo aspetto, è ovvio che maggiore è il carico antropico delle aree immediatamente limitrofe al corso d'acqua, maggiore saranno anche le problematiche di gestione delle relazioni tra le necessità dell'uomo e gli spazi vitali per il corso d'acqua. tale situazione è perfettamente riscontrabile nell'area oggetto della ricerca che fa parte del bacino del fiume po, il più lungo fiume italiano che attraversa da e a w la parte settentrionale della penisola: un settore densamente abitato, in cui l'uomo nel corso dei secoli ha progressivamente occupato ampie porzioni di territorio anticamente di pertinenza del fiume (govi & turitto, 1993; surian & rinaldi, 2003). in particolar modo, gli effetti più pesanti dell'azione dell'uomo sul corso d'acqua possono essere sicuramente ricondotti al xx secolo, durante il quale il prelievo di materiale in alveo ha raggiunto livelli molto elevati (govi & turitto, 1993). terminato il periodo a cavallo tra gli anni '50 e '70 in cui questo prelievo ha raggiunto l'apice (marchetti, 2002), è emersa a partire dagli anni '90 (soprattutto a causa anche di due catastrofici eventi alluvionali verificatisi nel 1994 e nel 2000) una nuova necessità di eseguire degli studi sul possibile trend evolutivo del “sistema po” finalizzato ad una corretta gestione delle risorse e delle criticità in esso presenti. in particolare, l'attenzione sia dei ricercatori che degli enti preposti alla gestione del territorio si è concentrata sull'evoluzione recente del corso d'acqua e sulle modalità per ottenere delle metodologie in grado di valutarne il trend evolutivo, al fine di definire uno strumento di pianificazione finalizzato alla gestione dei sedimenti (rinaldi et al., 2005). in tale ambito nascono e si sviluppano una serie di progetti di ricerca frutto della collaborazione scientifica tra l'aipo (agenzia interregionale per il fiume po) e il cnr irpi di torino, finalizzati alla definizione di una metodologia di studio per la comprensione dell'evoluzione dei corsi d'acqua da applicare ad una corretta opera di manutenzione e gestione. il progetto di ricerca ha visto impegnati i ricercatori e tecnici dei due enti a partire dal 2004 con una serie di attività volte soprattutto a studi a carattere storico abbinati all'utilizzo delle più moderne tecnologie di rilevamento quali i rilievi lidar light detection and ranging e quelli s i n g l e e m u l t i b e a m ( fr e n c h, 2003; an d e r s o n et al., 2006). le esperienze sperimentali note in letteratura hanno infatti evidenziato come grazie all'impiego di sistemi di monitoraggio ad alta risoluzione sia spesso possibile portare al riconoscimento ed allo studio delle dinamiche erosive e deposizionali (lawler, 2005); in particolare, l'utilizzo di dtm realizzati in serie sembra possa essere un valido strumento per lo studio della dinamica dei corsi d'acqua (lollino et al, 2005). è infatti emerso come la possibilità di generare modelli digitali del terreno (dtm) ad alta risoluzione con una densità di punti (che nel caso del lidar arriva ad essere di 2-8 punti al m2) consente di avere una definizione della superficie topografica su ampie aree difficilmente raggiungibile con altri strumenti. inoltre, la possibilità di ottenere dei rilevamenti in serie sui medesimi corsi d'acqua permette di poterli analizzare da un punto di vista morfologico (br a n s i n gt o n et al., 2006) e di valutarne le differenze in termini plano altimetrici e volumetrici, rappresentando così uno strumento conoscitivo estremamente efficace per la comprensione della evoluzione recente del corso d'acqua. tale approccio presuppone tuttavia la definizione di una metodologia che individui le tipologie di rilevamento da utilizzare per la realizzazione di dtm in modo da garantire un elevato grado di ripetibilità oltre che di affidabilità del dato. la metodologia messa a punto non deve solamente considerare i problemi tecnici connessi all'esecuzione dei rilievi, ma deve anche valutare le diverse caratteristiche dei vari corsi d'acqua presenti all'interno dell'area di studio. il “sistema po” è infatti un sistema molto complesso ed articolato, in cui sono presenti realtà anche molto diverse tra loro. date le caratteristiche del dato lidar e le sue limitazioni connesse alla scarsa (e comunque non affidabile) risposta in corrispondenza alle aree sommerse, è verosimile supporre che tale sistema non possa assolutamente essere considerato sufficiente per la restituzione di dtm continui, soprattutto nei casi in cui gran parte dell'alveo attivo si trovi ad essere sommerso per gran parte dell'anno. esiste dunque la necessità, se si vuol provare ad utilizzare il metodo di comparazione dei dtm in modo estensivo, di affiancare al lidar altre tecniche di rilevamento delle zone sommerse che siano in grado di colmare le lacune. le esperienze condotte sin ora hanno evidenziato come esistano sostanzialmente tre tipologie di strumentazione in grado di garantire tale possibilità: single beam, side scan sonar e multi beam. si tratta in tutti e tre i casi di sistemici sonici in grado di rilevare la profondità del fondale emettendo un singolo impulso o una sequenza di impulsi che, attraverso un sistema di posizionamento gps, può portare alla generazione di una nuvola di punti compatibile con quella prodotta dal lidar. il lavoro presentato riguarda una parte delle esperienze sin ora condotte su una serie di tratti di diversi corsi d'acqua del bacino padano che hanno permesso di giungere ad interessanti risultati relativi allo studio dei singoli tratti indagati corsi d'acqua e di fornire delle interessanti indicazioni per la messa a punto di una metodologia di riferimento da estendere progressivamente a tutto il bacino. l'obiettivo è infatti quello di aumentare il grado di conoscenza dello stato di evoluzione attuale dei corsi d'acqua del bacino padano utilizzando le nuove tecnologie disponibili, in modo da affiancare alle metodologie di studio e ricerca già in essere anche un approccio quantitativo che misuri l'evoluzione recente dei corsi d'acqua stessi. tale metodologia prevede l'utilizzo integrato dei dtm rilevati in epoca recente e della loro comparazione anche con i risultati derivanti dalla ricerca e dall'analisi della cartografia storica disponibile. lo studio condotto su un intervallo di tempo sufficientemente ampio (almeno 100 anni) permette di ricostruire nel tempo e nello spazio le variazioni planimetriche occorse al corso d'acqua, a cui vanno ad aggiungersi anche i dati ricavati per lo studio dell'evoluzione recente che hanno l'interessante caratteristica di essere in tre dimensioni, prendendo cioè anche in considerazione le variazioni altimetriche (prima difficilmente desumibili se non in corrispondenza a sezioni topografiche). partendo dal presupposto che un corso d'acqua sia un'entità che si evolve su una scala temporale che non è confrontabile con la percezione umana del tempo, questo studio va quindi visto come uno sforzo di integrare diverse tecniche d'indagine in modo da poter coprire un lasso di tempo il più possibilmente ampio con un dettaglio via via crescente. 2. metodologia utilizzata le attività di ricerca dei progetti condotti dal cnr irpi di torino sono state rivolte sia ad uno studio dell'evoluzione storica tramite la realizzazione di un sistema informativo delle differenti basi cartografiche e delle informazioni dedotte da riprese aerofotogrammetriche degli ultimi 150 anni, che ad una caratterizzazione delle condizioni attuali tramite analisi sedimentologiche e realizzazione di dtm ad alta risoluzione. in particolare, per mettere a punto una metodologia d'indagine basata sull'uso di dtm, sono stati presi in esame differenti porzioni di corsi d'acqua del bacino padano in modo da ottenere un set di dati ed esperienze che fossero il più possibile rappresentativi di diverse condizioni presenti nel bacino; particolar per tale ragione, sono stati analizzati con tecniche e metodologie di rilevamento differenti i seguenti tratti: • due tratti del fiume po: il primo, per un totale di circa 6 km, in corrispondenza a pontelagoscuro (fe) e il tratto di po di tolle da porto tolle al mare; i due tratti rilevati sono molto brevi e finalizzati esclusivamente a condurre una serie di valutazioni sull'operatività del side scan sonar; esiste infatti un rilevamento completo dell'alveo a cura dell'autorità di bacino del fiume po realizzato integrando la tecnica lidar con quella multibeam (filippi et al., 2004; camorani et al., 2006). rilevamenti eseguiti: lidar aereo + side scan sonar; anno di rilevamento: 2006 • il torrente orco regione piemonte, sinistra idrografica del fiume po; il tratto indagato è lungo circa 40 km (da pont canavese a confluenza po) e manifesta un assetto planimetrico riconducibile al modello fluviale che ha, come aspetto peculiare, la presenza di più canali di deflusso con interposte isole e numerose barre, a testimonianza della componente grossolana della granulometria che costituisce il fondo alveo dotato di elevata mobilità. rilevamenti eseguiti: lidar aereo; anno di rilevamento: 2003, 2004, 2006, 2007; • il fiume adda regione lombardia, sinistra idrografica del fiume po; il tratto indagato è lungo circa 21 km (da confluenza brembo a bisnate) e manifesta un andamento unicursale a tratti pseudomeandriforme. rilevamenti eseguiti: lidar aereo + single beam; anno di rilevamento: 2004, 2006 • il fiume taro regione emilia romagna, destra idrografica del fiume po; il tratto indagato è lungo circa 16 km (da fornovo di taro a noceto) in base a quelle che sono le classificazioni conosciute (rosgen, 1994; thorne, 1998) è molto difficile inquadrare la tipologia dell'alveo del fiume taro, che può essere definito come un corso d'acqua a più canali di deflusso, molti dei quali effimeri in condizioni di livelli idrometrici bassi. inoltre, da un'osservazione generale 333l’uso di modelli digitali nel terreno ... appare evidente come l'alveo del corso d'acqua si configuri come molto ampio con situazioni in cui i canali attivi scorrono in prevalenza nelle parti laterali, in destra e sinistra dell'alveo attivo. nella parte centrale si sviluppa un sistema di barre più o meno attive caratterizzate generalmente da una quasi totale assenza di vegetazione. rilevamenti eseguiti: lidar aereo; anno di rilevamento: 2004, 2006; • il fiume secchia regione emilia romagna, destra idrografica del fiume po; il tratto indagato è lungo circa 17 km (da confluenza torrente dolo a castellarano). il tratto di fiume secchia analizzato si inserisce ancora in un contesto decisamente appenninico, caratterizzato anche da un'importante interazione con la dinamica di versante molto attiva in quest'area. il fiume secchia ha sviluppato nel corso del tempo un andamento a più canali di deflusso raggiungendo in tratti e tempi diversi una morfologia di tipo braided, con la presenza di numerosi canali attivi (molti dei quali effimeri o di dimensioni ridotte al momento del rilievo). rilevamenti eseguiti: lidar aereo; anno di rilevamento: 2004, 2006; questa prima trance di rilevamenti ha coperto un'area di più di 60 km2, fungendo da test site per la messa a punto delle metodologie di rilevamento e di analisi dei dati oggetto del presente lavoro. ad essi si vanno attualmente aggiungendo ulteriori 250 km2 d i corsi d'acqua del bacino padano su cui si sta applicando la proposta metodologica ivi presentata, la quale è oggetto di un nuovo progetto di ricerca. l'impiego congiunto di dtm ad alta risoluzione degli ultimi anni e della ricerca storica ha permesso di integrare informazioni diverse sia in termini di scala temporale che di risoluzione; lo scopo è quello di unire efficacemente le diverse fonti di dato per riuscire ad ottenere una visione del fenomeno il più completa possibile. le tecniche utilizzate sono state impiegate con estrema attenzione, in modo da ottenere dei prodotti con un grado di precisione tale da permettere una loro comparazione per lo studio dell'evoluzione morfologica dei corsi d'acqua. in quest'ottica, sono stati sperimentati diversi sistemi in grado di rilevare sia la parte emersa che quella sommersa dell'alveo, cercando di ottenere sempre dei rilevamenti di tipo areale che fossero al tempo stesso rappresentativi del tratto indagato, ma che tenessero in somma considerazione anche la sostenibilità economica del rilevamento. per quanto riguarda le zone emerse, il sistema maggiormente utilizzato è stato il lidar aviotrasportato (gomes pereira & wicherson, 1999; charlton et al., 2003), al quale sono state affiancate reti gps di inquadramento e controllo e rilevamenti topografici di tipo tradizionale. nel caso, invece, delle zone sommerse, sono stati impiegati a seconda delle condizioni di navigabilità e della profondità media del fondale sia sistemi single beam che side scan sonar (horritt et al., 2006). tutti i set di dati sono stati verificati utilizzando punti di controllo a terra su aree ritenute invariate nel tempo. una volta accertata la conformità dei dati laser alle specifiche dichiarate dalla ditta esecutrice dei rilevamenti, che come verrà dettagliato in seguito sono risultate essere contenute in 15cm r.m.s. sulla componente ellissoidica wgs84, si è passati alle procedure di generazione delle superfici per il processo di confronto temporale. i dati ricavati sono infatti stati opportunamente processati attraverso una metodologia sperimentale messa a punto dal cnr che ha permesso di ottenere anche delle indicazioni interessanti in merito alle variazioni morfologiche occorse nel periodo considerato, sia di tipo qualitative che quantitative. le esperienze condotte nelle diverse realtà operative legate al particolare contesto morfologico hanno evidenziato come esista la necessità, per ottenere una procedura il più possibile omogenea, di definire uno schema classificativo che descrive le modalità di rilevamento per la creazione di un dtm in funzione della caratteristiche morfologiche del corso d'acqua; i dati sin ora raccolti hanno permesso di definire sperimentalmente tale schema che, allo stato attuale, deve comunque essere considerato ancora di tipo sperimentale. 2.1 tecniche di rilevamento lidar utilizzate e loro accuratezza per gli studi di comparazione effettuati si è partiti da una base dati costituita da rilevamenti lidar eli/aerotrasportati effettuati con sensori altm e riegl, abbinati a camere fotografiche rollei e hasselblad. i rilevamenti sono stati pianificati per l'acquisizione di una nuvola di punti con densità non inferiore a 2punti/mq, con una risoluzione fotografica di 15-20 cm/pixel. alla quota di volo media dei singoli voli, risultata essere di circa 500 700m agl (above ground l e v e l), l'affidabilità, verificata a posteriori, è risultata essere di circa 10 15cm sulla componente altimetrica ellissoidica wgs84, mentre quella planimetrica, sul medesimo ellissoide, è risultata essere di circa 20 40cm. poiché i modelli di planning di volo, vengono progettati per offrire ampie garanzie di copertura tramite dei coefficienti di sicurezza sui dati di input iniziali (densità di punti a terra; copertura trasversale e longitudinale delle strisciate fotografiche ecc.), la densità di punti al suolo riscontrata a posteriori è risultata essere decisamente superiore a quella di progetto, con presenza media di variabile tra 2 8 punti/mq). la risoluzione a terra delle ortofoto utilizzate è risultata essere di 20cm/pixel, con un'affidabilità di orientamento planimetrico del singolo tile appartenente all'ortomosaico di circa 40cm. tale margine, risultante congruente con quello della nuvola di punti laser, costituisce di fatto il margine di affidabilità con cui sono state effettuate le successive operazioni di scontornamento delle aree sommerse e delle aree reputate rappresentative per l'esecuzione dei computi volumetrici analitici secondo un procedimento che verrà descritto nel capitolo seguente. 2.2 tecnica di comparazione dei dtm i dati così rilevati sono stati utilizzati per lo studio dell'evoluzione morfologica del corso d'acqua attraverso una tecnica basata sul confronto multitemporale di dtm attraverso una metodologia sperimentale messa a punto dal cnr irpi (lo l l i n o et al., 2005). il procedimento prevede infatti l'esecuzione, mantenendo invariate le condizioni al contorno, di rilevamenti lidar aerotrasportati di tratti di corsi d'acqua ad intervalli temporali prestabiliti, per poterne poi valutare numericamente le variazioni; la frequenza con la quale vengono eseguiti tali rilievi è anch'essa oggetto di studio e deve essere correlata alla scala d'indagine geomorfologia (la n e et al., 1993). allo stato attuale dello studio, tale sistema prevede l'impiego di rilevamenti lidar e delle ortofoto ad esso associate per riconoscere e perimetrare, mediante interpretazione visiva l'area emersa dei tratti di alveo indagati. una volta definita la superficie su cui verranno eseguiti i calcoli analitici per la determinazione delle variazioni volumetriche occorse (il rilevamento lidar viene solitamente effettuato su un perimetro pari alla fascia b pai fascia fluviale che, per convenzione, prende in considerazione la superficie potenzialmente occupata dal corso d'acqua in occasione di una piena con tempo di ritorno duecentennale) si procede, a partire dalla nuvola di punti non regolarizzata (con densità tipicamente dell 'ordine di 2 8 punti/mq), alla creazione di grigliato a maglia regolare (definito in tale metodologia di ampiezza pari a 1m2) che indica punto per punto la variazione altimetrica media avvenuta tra i due rilievi. tale variazione, derivata da una maglia molto fitta e regolarizzata con passo di 1m2, risulta avere un'accuratezza media di circa 10-15cm sulla componente altimetrica ellissoidica wgs84. in questo modo è possibile ottenere sia delle tavole che evidenziano tali variazioni tramite scale di colori, che procedere ad un calcolo volumetrico delle variazioni avvenute (lollino et al., 2005). è tuttavia da sottolineare come tale metodologia non possa essere considerata come una semplice applicazione informatica, ma come un procedimento basato su una serie di tappe fondamentali alle quali corrispondono altrettante fasi di controllo dei r isultati ottenuti su basi geodetiche e gemorfologiche; il ruolo della geomorfologia nello studio di queste dinamiche è infatti fondamentale (co n ac h e r, 2002), ed anche nella metodologia sperimentale messa a punto dal cnr irpi svolge un ruolo di primaria importanza: sia la perimetrazione delle aree emerse che il successivo riconoscimento delle zone in cui è effettivamente avvenuta una variazione volumetrica superiore alla tolleranza strumentale delle misure avviene sì attraverso un'analisi di affidabilità del dato laser, ma soprattutto grazie all'impiego di ortofoto e tramite un'attenta analisi da parte di operatori esperti che valutano la corrispondenza tra i dati ottenuti e le evidenze morfologiche di tale evoluzione. da un punto di vista procedurale, il modello concettuale che regola il riconoscimento e l'estrazione delle zone su cui verrà calcolata la variazione volumetrica è schematizzato nella figura 1. è infatti importante sottolineare come uno dei limiti maggiori dell'impiego del lidar sia l'impossibilità da parte di tale strumento di restituire un modello digitale anche della parte d'alveo sommersa. per prima cosa si è dunque definita una procedura che permettesse l'estrazione delle aree sommerse e l'esclusione di esse dai calcoli successivi; questa limitazione, seppur importante, deve comunque essere valutata tenendo sempre in considerazione l'elevata risoluzione spaziale della strumentazione utilizzata (anderson et al., 2006) e la possibilità che tale strumento offre di condurre un'analisi di tipo areale e non più legata all'utilizzo di sezioni topografiche una tantum (che comunque restano di primaria importanza per il controllo del dato lidar e per relazionare i dati futuri 334 g. lollino et al. con l'importante bagaglio storico disponibile). oltre alle aree sommerse, un altro fattore che deve essere preso in seria considerazione sia durante il trattamento che l'analisi dei dati riguarda la presenza di vegetazione e il suo effetto sull'accuratezza della misura (he r i t a g e & he t h e r i n g t o n, 2007); anche in questo caso l'impiego delle ortofoto digitali permette di eseguire un controllo accurato della risultante dalla comparazione tra i dtm alla ricerca di eventuali anomalie. oggetto della ricerca è stata dunque anche la definizione delle modalità di realizzazione di un grigliato a maglia regolare (grid) da utilizzare per le operazioni di confronto dei dtm. il miglior compromesso in fatto di rappresentatività delle caratteristiche geomorfologiche e di utilizzabilità del dato per questioni di dimensioni dei file utilizzati è risultata essere la generazione di un grid a passo regolare di 1m. tale grid, utilizzato per le comparazioni, è derivato dall'interpolazione (con algoritmo natural neighborough) della nuvola di punti totale con densità sopra descritta attraverso un'azione di ricampionamento che ha, di fatto, diminuito il numero di punti a terra (non c'è stato quindi un'interpolazione volta ad infittire artificiosamente i dati di partenza ma, al contrario, una loro regolarizzazione mediante sfoltimento). in queste condizioni, sulla base di test effettuati con grid a passo minore, non sono state riscontrate apprezzabili differenze sulle stime analitiche a posteriori effettuate. l'approssimazione risultante, infatti, deve comunque essere figlia di una buona densità per unità di terreno, continuando quindi a rappresentare in maniera affidabile la morfologia del zona rilevata. l'utilizzo di maglie inferiori si sarebbe quindi tradotto in un eccessivo dilatamento dei tempi macchina necessari per processare la grande quantità di dati, senza tuttavia offrire maggiori vantaggi ai fini delle successive interpretazioni sul carattere evolutivo dei corsi d'acqua analizzati. i risultati ottenibili dal confronto dei dtm (figura 2) sono dunque un grid (sempre passo 1 m) che evidenzia le variazioni altimetriche occorse tra i due dtm ed un calcolo volumetrico eseguito sulle aree in cui si è avuta una reale variazione morfologica (validata sia dal g r i d che dall'analisi delle ortofoto) la metodologia fin ora descritta prende in considerazione i dtm derivati dall'utilizzo esclusivo dei dati lidar. tale metodologia può dunque apparire più complessa a causa della necessità di escludere tutte quelle aree in cui il dato lidar non è ritenuto attendibile; tuttavia, se si analizzano nel complesso le operazioni di rilevamento e trattamento dati, è possibile notare come essa risulti la più semplice perché connessa ad una sola fonte di dati. non a caso tutto il procedimento è nato su queste basi e si è sviluppato successivamente affiancando anche altri sistemi di rilevamento batimetrico in grado di completare le zone in cui il dato lidar è lacunoso. nel caso, dunque, si consideri anche il contributo di altre fonti di dati il procedimento non cambia nella sostanza, ma ad esso devono essere aggiunti solamente alcuni passaggi: dopo aver depurato il dato lidar dei dati non considerati attendibili, si aggiungono nelle medesime aree quelli provenienti dagli altri sistemi di rilevamento, ottenendo così un dtm senza lacune. il successivo procedimento di comparazione dei dtm non cambia, così come non cambiano i risultati ottenibili. 3. approccio metodologico alle attivita' di rilevamento e studio dei corsi d'acqua del bacino padano: linee guida e risultati ottenuti una volta definito il metodo per il trattamento dei dati e l'esecuzione del processo di comparazione, prima fondamentale tappa nello sviluppo della metodologia presentata, ci si è concentrati sulla sua applicabilità su vaste aree quali, per esempio, il bacino padano. l'elemento fondamentale chiaramente emerso sin dalle prime battute riguarda la forte eterogeneità dell'ambito studiato, che si riflette necessariamente sulle modalità di esecuzione delle attività di rilevamento per la creazione dei dtm. oggetto della ricerca appare dunque non essere solo la valutazione delle potenzialità dei dtm e del loro utilizzo, ma anche tutto ciò che concerne le operazioni di rilevamento per la generazione degli stessi. per utilizzare al meglio le potenzialità dei dtm risulta infatti sempre più evidente come sia necessario poter definire delle linee guida per l'esecuzione degli stessi, in modo da ottenere dei dati omogenei e tra loro comparabili. il tema risulta essere quanto mai attuale, in quanto, al momento, molti enti ed unità di ricerca hanno infatti fatto eseguire rilevamenti in aree specifiche senza 335 fig. 1 schema concettuale delle fasi principali del processo di comparazione dei dtm (lollino et al. 2005). conceptual framework of principal dtms comparison process phases (lollino et al 2005). l’uso di modelli digitali nel terreno ... tuttavia utilizzare un sistema univoco di esecuzione (esistono infatti delle specifiche che riguardano quasi esclusivamente i rilevamenti lidar, o le caratteristiche dei dtm, ma non contemplano, per il momento l'insieme delle possibili correlazioni strumentali). lungi dal voler pretendere di rappresentare un prospetto esaustivo delle possibilità di rilevamento nelle diverse realtà di un sistema complesso come quello del bacino padano, è tuttavia possibile tracciare un primo bilancio delle esperienze condotte dal cnr irpi di torino in base ai dati acquisisti in questi ultimi anni (i primi rilevamenti risalgono infatti al 2003): l'approccio al momento più efficace pare possa essere quello di definire differenti tipologie di utilizzo combinato di più strumentazioni, in funzione delle caratteristiche morfologiche del singolo corso d'acqua analizzato. per fare ciò è possibile proporre un primo e molto schematico raggruppamento dei corsi d'acqua in macro categorie che 336 fig. 2 tavola che mostra la risultanza grafica del processo di elaborazione dei dtm; nell'immagine sono evidenziate le aree che hanno subito delle variazioni altimetriche e su cui è stato eseguito il relativo calcolo delle variazioni volumetriche. si noti inoltre come vi siano dei settori in cui non è presente il grigliato ma un graticciato nero: sono le zone in cui è stato eseguito il confronto dei dtm e su cui non sono state riscontrate variazioni volumetriche. board showing graphic results of dtm processing; in the picture are highlighted areas with height variations where volumetric change computation was performed. there are sectors without a grid but marked with black grating: these are zones where dtm comparison was made and where no appreciable volumetric changes were detected. g. lollino et al. tengano conto del battente d'acqua medio nei periodi di magra e del rapporto tra superficie dell'alveo di magra e dell'alveo ordinario. in questo modo è quindi possibile formulare una classificazione che lega le modalità di rilevamento e generazione dei dtm alle caratter istiche morfologiche dei corsi d'acqua. l'obiettivo è ovviamente quello di generare un dtm completo dell'alveo, tenendo tuttavia in considerazione i rapporti costi/benefici delle singole attività di rilevamento. è infatti probabile che, a fronte di un rilevamento continuo su tratti d'alveo considerevoli, la presenza di qualche zona senza dato, soprattutto se paragonate a metodi di studio basati su sezioni spesso distanti anche alcuni chilometri, possa essere considerata un compromesso accettabile. qui di seguito viene dunque illustrata una proposta di lavoro sperimentale, in cui per ogni tipologia di corso d'acqua sono anche stati descritti una parte dei risultati raggiunti. i risultati descritti sono presentati a titolo di esempio e non vogliono essere una descrizione esaustiva degli studi condotti, ma solamente la testimonianza dell'efficacia dell'approccio utilizzato. 3.1 affluenti del fiume po a torrenti in aree di montagna, con materasso alluvionale non continuo ed alveo talvolta profondamente inciso direttamente nel substrato roccioso. in questi settori l'impiego della metodologia basata sui dtm potrebbe risultare poco efficace, le attività di rilevamento sono infatti rese difficoltose sia dalla presenza dei versanti che, molto spesso, dall'elevata vegetazione anche ad alto fusto presente in alveo. inoltre, data l'elevata pezzatura del materiale in alveo e la sua disomogenea distribuzione, il rischio di rilevare delle ampie porzioni di territori per poi concentrasi su poche e poco estese aree su cui le condizioni permettono lo studio tramite il confronto di dtm rende il metodo difficilmente sostenibile; nel caso in cui ci siano delle realtà molto particolari e strategiche si rende quindi necessario eseguire delle approfondite valutazioni preliminari caso per caso in quanto il rapporto costi/benefici può non essere a favore di un rilevamento lidar. capitolo a parte meritano le zone di conoide, dove i rilevamenti lidar possano essere considerati come un ottimo strumento per l'esecuzione di modelli dtm attraversi i quali definire differenti caratteristiche morfologiche e morfometriche (cavalli & marchi, 2008) ed in base ai quali estrarre sezioni topografiche per la costruzione di modelli numerici. b corsi d'acqua pluricursali in zone di pianura, con battente d'acqua medio di molto inferiore al metro (periodo di magra), e forte differenza in termini di aree relative all'alveo di magra (indicativamente il 15%) ed alveo ordinario. in questo caso l'esecuzione di un rilevamento lidar può essere considerato una soluzione esaustiva; il rilevamento è da eseguire necessariamente durante i periodi di magra che, nel caso analizzato coincidono con la stagione estiva o quella tardo invernale (rispettivamente i mesi di agosto o febbraio). le esperienze sin ora condotte hanno evidenziato come tutti e due i periodi possibili per l'esecuzione dei rilevamenti siano caratterizzati da una serie di vantaggi e svantaggi: durante il periodo estivo sussiste il problema della maggior copertura vegetativa, derivante soprattutto dalle latifoglie che schermano anche pesantemente il raggio laser mascherando porzioni di territorio; durante il periodo invernale possono esserci problemi connessi alla copertura di neve alla quote più alte e di repentina variabilità delle condizioni meteo che rendono difficoltosa la fase di pianificazione del volo; nel periodo invernale, inoltre, le foto abbinate al rilievo sono spesso meno contrastate e caratterizzate da ombre più lunghe che ne riducono sensibilmente l'efficacia. per quanto riguarda le portate spesso non ci sono sostanziali differenze tra quelle estive ed invernali, fatto slavo per l'effetto legato ai prelievi antropici: è infatti emerso in molti casi come i prelievi connessi alla presenza di canali irrigui riducano fortemente la portata in alveo. è importante ribadire nuovamente che il dtm così realizzato può presentare dei tratti in cui manca il dato di fondo alveo, spesso molto importante per lo studio del corso d'acqua; tuttavia, la disponibilità di un dato molto fitto delle zone emerse consente spesso un facile completamento del dato con altre metodologie di rilevamento tradizionali (per esempio rilevamenti gps rtk), che può essere eseguito eventualmente anche solo in corrispondenza alle sezioni topografiche tradizionali, permettendo così un abbinamento tra le due metodologie d'indagine e confronto. tale soluzione di compromesso è spesso necessaria in quanto le energie necessarie per effettuare il completamento di tutto l'alveo sono ingenti, rispetto alla limitata entità del territorio da rilevare. un esempio di questa tipologia di corso d'acqua è il tratto rilevato del fiume taro (da fornovo di taro a noceto, per una lunghezza di circa 16 km); si tratta di un corso d'acqua di tipo b r a i d e d con depositi di tipo sabbioso ghiaioso. in questo caso il rilievo ha interessato un area di circa 15 km2 di cui 6.37 km2 di alveo attivo; di questi ultimi il 17 % corrisponde all'area esclusa dal procedimento di comparazione dei dtm in quanto sommersa almeno durante uno dei due rilevamenti, mentre su un'area corrispondente a ben 83 % è stato possibile effettuare la comparazione dei dtm. i risultati ottenuti comparando il rilievo del 2004 con quello eseguito nel 2006 hanno evidenziato un bilancio volumetrico complessivo pari a: 630 m3 legati a variazioni positive e 475 m3 connessi invece a settori in cui le variazioni sono state negative. il risultato è un bilancio positivo di 154 m3.di materiale sedimentato nell'arco di due anni. oltre al dato volumetrico, il procedimento di comparazione permette di ottenere anche delle tavole tematiche che esprimono la variazione altimetrica espressa mediante un grigliato con celle di 1 m2. queste tavole dimostrano chiaramente la tendenza evolutiva del corso d'acqua tramite la migrazione laterale dei canali e delle barre tipica di questa tipologia di corso d'acqua (figura 2). c corsi d'acqua unicursali con battenti d'acqua medio superiore al metro e con alveo molto incanalato (spesso caratterizzato anche dalla presenza di difese spondali continue che ne limitano fortemente la possibilità di divagare lateralmente), poca differenza tra alveo di magra ed alveo ordinario, con una superficie sommersa anche durante i periodi di magra superiore al 50% dell'alveo ordinario. in questo caso, invece, il rilevamento lidar deve necessariamente essere imple337l’uso di modelli digitali nel terreno ... mentato con rilevamenti batimetrici che ne vadano a completare la parte sommersa (coren et al., 2003). data la scarsa continuità dal punto di vista della navigabilità che spesso caratterizza gli affluenti del fiume po che hanno queste caratteristiche, sono da preferire sistemi di rilevamento single beam abbinati a natanti tipo hovercraft in grado di muoversi su tutti i terreni; tale configurazione si rende quanto mai necessaria soprattutto se si eseguono i rilevamenti durate il periodo primaverile o autunnale, in cui la poca copertura vegetativa delle sponde e le giornate non molto corte favoriscono la produttività del rilievo. un esempio può essere considerato il caso del fiume adda. il tratto di adda analizzato (da confluenza brembo a bisnate, per una lunghezza di circa 21 km) è caratterizzato da uno andamento in prevalenza unicursale. questo assetto planimetrico è dovuto all'elevato grado di antropizzazione di entrambe le sponde, lungo le quali la presenza di argini è pressoché continua. in questo caso la sola possibilità di ottenere un rilevamento continuo anche delle zone caratterizzate da battenti d'acqua molto bassi è risultato essere quello di utilizzare un hovercraft (fig. 3) come mezzo di trasporto; tale mezzo permette infatti di viaggiare indifferentemente su acqua e terra utilizzando un cuscino d'aria prodotto dal mezzo stesso. il mezzo ha la possibilità navigare sia in modali tà stazionaria (senza cuscino d'aria e con lo scafo a fondo piatto in acqua con un pescaggio r idotto di pochi centimetri), durante la quale avvengono le attività di rilevamento, che di navigare su cuscino d'aria, per effettuare i trasferimenti a velocità più sostenuta. la figura 4 evidenzia l'inserimento delle traiettorie del rilevamento batimetrico (tracciati in bianco all'interno dell'alveo) nel contesto lidar; è chiaro che in questo caso la densità di punti della zona sommersa è inferiore a quella del lidar; le esperienze condotte dimostrano comunque che a seconda della forma dell'alveo e della velocità della corrente (che influisce molto sulla manovrabilità del mezzo), è possibile ottenere un buon modello anche solo con una singola passata sinuosa, eventualmente abbinata a due rilevamenti laterali che ne definiscono meglio la morfologia sommersa delle sponde. 3.2 fiume po sino ad ora sono stati trattati solamente gli affluenti del fiume po, il quale costituisce, almeno nel suo tratto a valle di torino, un corso d'acqua con caratteristiche differenti da quelle precedentemente descritte, soprattutto per quanto riguarda la portata (e di con338 fig. 3 hovercraft allestito con un supporto verticale dotato di sensori single beam e gps rtk. hovercraft used for single beam and rtk gps surveys. fig. 4 esempio di rilevamento del fiume adda con accoppiamento dato lidar e single beam. example of adda river reach survey with lidar and single beam point cloud. g. lollino et al. seguenza la corrente) e le caratteristiche morfologiche. a sua volta, dal punto di vista delle modalità di rilevamento e navigabilità, questo settore può essere ulteriormente suddiviso in due sottotratti: a il settore a monte di cremona, caratterizzato da non continue condizioni di navigabilità e da un alveo di magra spesso considerevolmente inferiore all'alveo ordinario. in quest'area è possibile un utilizzo congiunto di rilevamenti lidar aviotrasportato e single beam (da utilizzare su natanti di dimensione adatta in funzione delle condizioni di navigabilità e della velocità della corrente). un esempio di tale modalità di rilevamento può essere considerato il caso della confluenza po-sesia. per la realizzazione di un modello idraulico di tale settore (fugazza et al., 2007), il cnr irpi è stato chiamato ad eseguire un rilevamento dell'intera area ed a fornire un dtm completo della parte sommersa ed emersa. in questo caso le condizioni di navigabilità hanno permesso di utilizzare un gommone a motore su cui è stato installato un single beam con posizionamento tramite gps rtk. le attività di rilevamento si sono dimostrate non di facile esecuzione a causa dell'elevata corrente e delle variazioni di profondità del fondale che hanno reso difficoltoso il passaggio del mezzo soprattutto nelle zone di collegamento tra due anse successive caratterizzate da un ridotto battente d'acqua. b settore a valle di cremona, caratterizzato da condizioni di navigabilità relativamente continue anche per natanti di dimensioni maggiori, in cui i rilevamenti della parte emersa costituiscono un elemento importante quasi esclusivamente nelle aree di golena, mentre i rilevamenti della porzione sommersa costituiscono la parte preponderante del rilievo. in questo caso è possibile utilizzare anche degli apparati più complessi e performanti dei single beam quali i sistemi multi beam o side scan sonar; si tratta di sistemi per l'esecuzione di rilevamenti batimetrici caratterizzati da una emissione di un fascio di impulsi che nascono per il rilevamento marino (gardner et al., 2003), che possono anche essere applicati a grandi fiumi navigabili. indipendente dal sistema utilizzato, queste strumentazioni sono in grado di emettere un fascio di impulsi e di registrarne i segnali di ritorno, che poi dovranno essere sincronizzati con i segnali provenienti dal gps e compensati in base alle informazioni provenienti da un sistema inerziale in grado di misurare le variazioni di assetto (beccheggio, rollio e imbardata) del natante. l'elemento discriminate per la scelta del sistema più opportuno è rappresentata proprio dalla profondità media del fiume: per l'impiego di sistemi più complessi è richiesta una profondità che superi con una discreta continuità i due metri e che renda possibile l'utilizzo di un natante di medie dimensioni in grado di alloggiare tutta la strumentazione a bordo. un esempio tratto dal progetto di ricerca è il rilevamento eseguito nei pressi di pontelagoscuro, nei pressi di ferrara. si tratta di uno dei nodi idraulici importanti per il po (basti pensare all'evento dell'ottobre 2000, durante il quale fu in parte sollevato il ponte ferroviario per il timore che l'ondata di piena non potesse transitare proprio in corrispondenza a tale attraversamento). per i rilevamenti eseguiti sì è optato per un s e n s o r e side-scan sonar in quanto caratterizzato da una maggior operatività in acque basse. questo tratto campione ha permesso di valutare il grado di correlabilità tra dato lidar e side scan sonar, ottenendo un dtm completo dell'alveo con un grado di dettaglio estremamente elevato. 4. conclusioni sino ad ora sono state esposte una serie di esperienze condotte dal cnr irpi di torino nell'ambito del rilevamento dei corsi d'acqua finalizzato alla creazione di dtm ed ad un loro utilizzo per tentare di valutare quantitativamente l'evoluzione morfologica degli stessi. la disponibilità di strumentazioni per il rilevamento sempre più avanzate offre infatti oggi nuove possibilità per lo studio dell'evoluzione del territorio attraverso tecniche di rilevamento e monitoraggio dello stesso. l'utilizzo di strumentazioni lidar per lo studio dell'evoluzione topografica di un determinato settore soggetto a delle dinamiche evolutive esogene non è certo più una novità, ma trova applicazioni in ambiti geomorfologici sempre più vasti e differenziati (wh i t e & wa n g, 2003; hu n t e r et al., 2003; mcke a n & ro e r i n g, 2004; gold, 2004; schultz, 2004; lawler, 2005; thoma et al., 2005; lollino et al., 2007). tuttavia, se paragonate ad altri ambiti come, per esempio, i fenomeni franosi, le esperienze di monitoraggio condotte sui corsi d'acqua con questi mezzi non sono ancora molte. molto probabilmente la spiegazione è relativamente semplice e va ricercata nella maggior complessità che caratterizza un corso d'acqua, sia in termini di variabilità spaziale delle sue caratteristiche geomorfologiche, che dell'ampiezza del rilevamento e delle energie necessarie per eseguirlo, le quali sono decisamente più elevate rispetto ad un contesto arealmente più contenuto e topograficamente più omogeneo come un fenomeno franoso. in più, la necessità di doversi confrontare con l'interfaccia acqua/aria e di dover necessariamente abbinare differenti tecniche di rilevamento rende il tutto molto complesso. malgrado tali difficoltà, in italia come in altri paesi (french, 2003) sono già stati realizzati, o sono in procinto di esserlo, ampi progetti finalizzati al rilevamento dei corsi d'acqua principali: tra di essi va sicuramente citato il “piano straordinario di telerilevamento ad alta precisione per le aree a rischio idrogeologico” (previsto dall'articolo 27 della legge n.179/2002) del ministero dell'ambiente e della tutela del territorio e del mare. questi progetti di ampio respiro forniranno ovviamente una mole di dati importante e molto probabilmente evidenzieranno anche come via siano ancora una serie di problematiche non risolte sulle modalità di rilevamento dei corsi d'acqua. l'esperienza accumulata dal cnr irpi ha permesso infatti di evidenziarne alcune e di cominciare ad ipotizzare delle possibili soluzioni, tenendo presente che uno dei concetti basilari per il monitoraggio di un qualsiasi fenomeno naturale consiste nella ripetibilità del rilevamento con modalità analoghe, in quanto l'obiettivo delle attività di rilevamento legate al monitoraggio consiste infatti nella possibilità di rendere confrontabili più set di misura. come precedentemente evidenziato, infatti, l'oggetto della ricerca connesso allo studio dei corsi d'acqua non riguarda solamente l'utilizzo dei dtm e dei dati derivabili dal loro confronto, ma anche le tecniche stesse con cui tali dtm devono essere generati. 339l’uso di modelli digitali nel terreno ... nasce da qui la proposta metodologica sulle modalità di rilevamento dei corsi d'acqua in grado di mettere in correlazione le tecniche e gli strumenti per il rilevamento con le caratteristiche morfologiche dei corsi d'acqua stessi. la possibilità di analizzare diversi tratti di corsi d'acqua all'interno del bacino padano ha infatti evidenziato come sia possibile definire uno schema classificativo estremamente semplificato da un punto di vista morfologico ma con una elevata valenza operativa per quanto riguarda le operazioni di rilevamento dell'alveo. oltre alla proposta di relazionare le modalità di rilevamento con le caratteristiche del corso d'acqua, la disponibilità di tali dati apre anche nuovi orizzonti di ricerca inerenti al loro utilizzo; le tecnica sperimentale di comparazione dei dtm rappresenta infatti un primo passo in tale direzione, che in parte può permettere di intuire quale possa essere il potenziale di tale nuova tipologia di dato. l'utilizzo dei dtm rende infatti possibile un approccio nuovo e di tipo continuo, su vaste porzioni di territori, completamento slegato da metodi consolidati basati sullo studio delle sezioni topografiche; per certi versi, infatti, il processo di comparazione tra dtm può essere considerato come il naturale successore delle sezioni topografiche, oggi reso possibile dalle nuove tecnologie. i dtm realizzati oggi hanno infatti un elevato valore perché sono l'equivalente “moderno” delle prime sezioni topografiche in alveo, oggi ritenute preziosissime in quanto in grado di valutare, a distanza di anni, le modificazioni occorse in quei determinati punti considerati rappresentativi. inoltre, la possibilità di poter valutare con continuità le variazioni occorse in un ambito tridimensionale offre anche delle elevate potenzialità nel calcolo delle variazioni volumetriche (lo l l i n o et al., 2005), introducendo un ulteriore valore aggiunto alla tecnica messa a punto. malgrado i risultati raggiunti, appare comunque chiaro e deve essere sottolineato come tali dati riguardino al momento un lasso temporale estremamente ridotto e del tutto inadeguato a formulare delle ipotesi chiare sulla possibile evoluzione dei corsi d'acqua; esiste quindi la necessità di lavorare utilizzando un approccio integrato che permetta di rendere disponibili tutte le fonti di dati in un unico sistema. anche in questo caso la tecnologia è in grado di fornire una possibile soluzione attraverso l'utilizzo di sistemi informativi territoriali, in grado di accogliere in un'unica struttura di gestione sia i dati storici che i dati connessi al monitoraggio con le più moderne tecniche disponibili. in questo modo è possibile analizzare le variazioni morfologiche occorse nel tempo, passando dinamicamente da dati storici risalenti ad oltre un secolo fa, ai rilevamenti lidar eseguiti negli ultimi anni. e' ovvio che tale varietà di fonti diverse debba essere analizzata con cautela, tenendo sempre presente quali siano le caratteristiche ed i limiti di tutte le informazioni presenti all'interno del sistema informativo; tuttavia, la possibilità di creare un continuum in grado di evidenziare le variazioni morfologiche occorse nel tempo, consente la formulazione di una serie di ipotesi in merito all'evoluzione del corso d'acqua e mette in luce come tali variazioni siano spesso legate anche (e forse soprattutto) all'intervento dell'uomo. sebbene a scale diverse e con un diverso grado di dettaglio, i dati ricavati dai vari corsi d'acqua raccontano una storia in cui l'evoluzione del corso d'acqua è da molto tempo ormai inevitabilmente da mettere in relazione con gli interventi umani, siano essi finalizzati a difendere le strutture già esistenti o a edificare nuovi edifici o sistemi di comunicazione. in tutto questo non va dimenticato il ruolo preponderante assunto dall'attività estrattiva in alveo, soprattutto nell'immediato dopoguerra e fino agli anni ottanta, quando la legislazione ha messo un freno a questa pratica. da questo punto di vista il metodo di confronto dei dtm basato sul rilevamento lidar si sta rivelando uno strumento molto potente per la comprensione delle dinamiche recenti responsabili della situazione attuale dei tratti di corsi d'acqua analizzati. risulta quindi opportuno, alla luce dei risultati sperimentali ottenuti, procedere alla definizione di una metodologia in grado di definire un sistema univoco di rilevamento di questi ambienti, per procedere alla progressiva creazione di un rilievo completo dell'intero “sistema po” da utilizzare come punto di partenza per indagini future. bibliografia anderson e.s., thompson j.a. & crouse d.a. & austin r.e. (2006) horizzonta resolution and data density effect on remotely sensed lidar-based dem geoderma, 132, pp. 406-415. br a s i n g t o n j., la n g h a m j. & ru m s b y b. (2003) methodological sensivity of morphometric estimates of coarse f luvial sediment transport geomorphology, 53, pp. 299-316. camorani g., filippi f., cavazzini a., lombardo g., papp a n i g. & fo r l a n i g. (2006) il rilievo altimetrico nel tratto tra confluenza ticino e l'incile asita 2006, 1, pp. 320-326. cavalli m. & marchi l. (2008) characterisation of the surface morphology o fan alpine alluvial fan using airborne lidar nat. hazards earth syst. sci., 8, pp. 323-333. charlton m. e., large a. r. g. & fuller i. c. (2003) application of airborne lidar in river environments: the river coquet, northumberland uk earth surface processes and landforms 2 8, pp.299-306. co r e n f., ma s o m. & pa g a n i n i p. (2003) s t e r z a i integrazione di dati laser scan e multibeam per la generazione di dtm ad alta risoluzione: studio del fiume brenta asita 2003, 1, pp. 819-824. co n a c h e r a. (2002) a role for geomorphology in integrated catchment management australian geographical studies, 40 (2), pp. 179-197. filippi f., colombo a., banchini g., cavazzini a., lombardo g., manzino a. & rinaudo f. (2004) il nuovo dtm dell'autorità di bacino del fiume po asita 2004, 2, pp. 1093-1098. french j. r. (2003) airborne lidar in support of geomorphological and hydraulic modelling earth surf. process. landforms 28, pp. 321-335. fu g a z z a m., ma g r i p., na t a l e l & sa v i f. (2007) l a piena del po alla confluenza con il sesia nell'ottobre 2000 l'acqua, 6, pp. 9-16. gardner, j.v.,dartnell p., mayer, l.a. & clarke j.a.h. (2003) geomorphology, acoustic backscatter, and processes in santa monica bay from multi340 g. lollino et al. beam mapping marine environmental research 56, pp. 15-46. gomes pereira l.m. & wicherson r.j. (1999) suitability of laser data for deriving geographical information. a case study in the context of management of fluvial zones isprs journal of photogrammetry & remote sensing 54, pp. 105-114. go l d rd. (2004) a comparative study of aerial phoyographs and lidar imagery for landslide detection in the puget lowland, washington. washington division of geology and earth resources. open file report 2004-6. govi m. & turitto o. (1993) processi di dinamica fluviale lungo l'asta del po acqua aria, 6, pp. 575588. heritage g. & hetherington, d. (2007) towards a protocol for laser scanning in fluvial geomorphology earth surf. process. landforms 32, pp. 66-74. horritt m.s., ba t e s p.d. & ma t t i n s o n m.j. (2006) effects of mesh resolution and topographic representation in 2d finite volume models of shallow water fluvial flow journal of hydrology, 329, 306-314. hunter g., pinkerton h., airey r. & calvari s. (2003) the application of a long-range laser scanner for monitoring volcanic activity on mount etna journal of volcanology and geothermal research 123, pp. 203-210. la n e, s.n., ri c h a r d s k.s. & ch a n d l e r j.h. (1993) developments in photogrammetry; the geomorphological potential progress in physical geography 17, pp. 306-328. lawler d.m. (2005) the importance of high-resolution monitoring in erosion and deposition dynamic studies: examples from estuarine and fluvial systems geomorphology, 64, pp. 1-23. lollino g., baldo m., giordan d. & allasia p. (2005) new methodology to evaluate morphological changes of river reaches: the case of orco river (piedmont, italy) international conference of reservoir operation & river management (icrom'05), september 17-23, 2005, guangzhou and three gorges, china. 8 pp. lollino g., pasculli a., sciarra n., baldo m. & giordan d. (2007) an integrated methodology based on lidar, gps and photogrammetric surveys applied to large landslide in san martino sulla marrucina (central italy) in proceedings of first north american landslide conference (editors: schaefer v.r., schuster r.l., turner a.k.), vail colorado, aeg special publication, 2 3, pp. 356365. mcke a n j. & ro e r i n g j. (2004) objective landslide detection and surface morphology mapping using high-resolution airborne laser alt imetry geomorphology, 57, pp. 331-351 ma r c h e t t i m. (2002) environmental changes in the central po plain (northern italy) due to f luvial modifications and anthropogenic activities geomorphology, 44, pp. 361-373. ri n a l d i m., wy z g a b. & su r i a n n. (2005) s e d i m e n t mining in alluvial channels: physical effects and management perspectives river research and applications, 21, pp. 805-828. rosgen d.l. (1994) a classification of natural rivers catena, 22, pp. 169-199. schulz w.h. (2004) landslides mapped using lidar imagery, seattle, washington u.s. geological survey, open-file report 2004-1396. su r i a n n. & ri n a l d i m. (2003) morphological response to river engineering and management in alluvial channels in italy geomorphology, 50, 307-326. th o m a d.p., gu p t a s.c., ba u e r m.e. & ki r c h o f f c . e . (2005) airborne laser scanning for riverbank erosion assessment remote sensing of environment, 95, pp. 493-501. thorne c.r. (1998) stream reconnaissance handbook. geomorphological investigation and analysis of the river channels. wiley, chichester, 113 pp. wh i t e s.a. & wa n g y. (2003) utilizing dems derived from lidar data to analyze morphologic change in the north carolina coastline remote sensing of environment, 85 (1), pp-39-47. 341 ms. ricevuto il 21 dicembre 2007 testo definitivo ricevuto il 23 aprile 2008 ms. received: december 21, 2007 final text received: april 23, 2008 l’uso di modelli digitali nel terreno ... available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 36 (2), 2023, 205-220 neotectonics as a procedure to uncover active seismogenic faults: the present efficacy of the italian approach matured in 1970-1980 fabrizio galadini, stefano gori, emanuela falcucci istituto nazionale di geofisica e vulcanologia, roma, italy. corresponding authors: stefano gori <stefano.gori@ingv.it> abstract: studies on active and capable faults produce data that presently have a key role in the broad field of earthquake geology, as well as in planning engineering works and land use. in regions with high deformation rates, the approach through paleoseismology could be sufficient to collect data necessary to depict active faults behavior. by contrast, a similar approach may be inappropriate in tectonic domains which are characterized by slower deformation rates, like italy. in such areas, neotectonics as expressed by carlo bosi in 1992 “integrated set of researches with the aim to define the plio-quaternary tectonic evolution defined through a temporal scan of hundreds of thousands of years” provides valuable insights into studying active tectonics and related faulting. indeed, through the evolutionary perspective, which goes far beyond a “static” multidisciplinary approach, neotectonics appears as a necessary procedure to define the active faulting setting of a region, representing the effect of the current tectonic regime. hence, the structural settings produced by neotectonics represent the basis for seismotectonic settings, as they incorporate those faults that are active seismogenic, which can be capable or not. overall, this has effects in terms of definition: a fault can be considered active if it exhibits evidence of movements within a time frame consistent with the ongoing tectonic regime of the region, unless it is sealed by deposits and/or landforms not younger than a time span (from the present) whose duration encompasses a significant number of seismic cycles on the respective fault. neotectonics, defined as a procedure, permits to connect active faults to their “engine”, that is tectonics. this sets the basis for its methodological predictive effectiveness in seismotectonic studies. keywords: neotectonics, active fault, seismogenetic source, italy, carlo bosi. 1. introduction active faults are manifestations of the stress regime acting in a given region. while there are a few known cases of creeping faults (excluding those connected to volcano-tectonics), faults that determine “slow earthquakes”, or the still poorly understood phenomenon of sympathetic fault slip, movement of active faults typically results in the sudden release of stress accumulated in rock masses, leading to the generation of earthquakes. this category of geological structures is here addressed. decades of modern research, at least since the first half of the 20th century, have defined the key role of the geological and geomorphological investigations along the surficial expressions of active faults to collect information concerning surface displacement/ deformation hazard, seismogenic sources and related implications in terms of ground shaking. considering the relevant consequences of this branch of study, fundamental question raises, such as: what defines an active fault? which characteristics must a fault display to be considered active and seismogenic? to answer these questions, the concept of “active fault” is very often associated with the terms “paleoseismology”, “active tectonics”, “neotectonics”, defined according to views expressed in milestones of the dedicated literature. among the reference publications, mccalpin (2009) stated the difference between paleoseismology and the other study fields, indicating the former as a “subdiscipline within the much broader fields of neotectonics, active tectonics and earthquake geology”. within this light, paleoseismology completes neotectonics: “paleoseismic histories […] help us understand many aspects of neotectonics, such as regional patterns of seismicity and tectonic deformation as well as the seismogenic behavior of specific faults”. this represents a logic definition, since neotectonics is considered as “the study of the post miocene structures and structural history of the earth’s crust”. an explicit chronological constraint is provided by caputo & helly (2008) who defined neotectonics as a discipline contributing to the study of earthquake geological records in the past (few) millions of years up to the last hundreds of thousand years, after which other disciplines contribute more effectively, such as paleoseismology, archaeoseismology, historical research, etc. another current of thought defines consistency with the present tectonic regime (machette, 2000). indeed, the author defined that “neotectonic faults are thought of herein as those formed during the current stress regime; that is, the one presently causing earthquakes and surface deformation in an area”. a consequence is that neotectonics should not be applied within a specific chronological interval valid everywhere, considering the variability of the tectonic domains. https://doi.org/10.26382/amq.2023.10 mailto:biagio.giaccio@cnr.it galadini et al. this has been more recently confirmed by wu & hu (2019), who stated that “the time scale of neotectonics is closely related to the geodynamics of a particular region focusing on the geological processes at time scales from ma to ka, and ‘past and present’ tectonic movement”, while “active tectonics places much more attention on the geological-morphological processes since 100-150 ka bp, and it is more oriented to understand the ‘present and future’ tectonic deformation”. other points important for our work, raised by wu & hu (2019), are related to the time scale of neotectonics, which “could be relatively broad”. a consequence is that “limits exist when it is applied to study the latest tectonic activities”, since pliocene or miocene faults may not activate within the framework of the current tectonic regime. and also “active tectonics is a significant branch and extension of neotectonics and the latter can be considered as the basis of understanding of the former”. therefore, on one side, these authors define chronological constraints since a broad time span of investigation is attributed to neotectonics, longer than that attributed to active tectonics, considering its practical application in the past 100-150 ka bp. on the other side, the same authors consider the study of neotectonics as a starting point to investigate active tectonics and invoke the possibility that faults derived from neotectonics may be presently inactive. as for the chronological aspects, the not univocal interpretation may also depend on the term “neotectonics” itself, as it basically “sounds” like the study of the “new” tectonics, or “recent” tectonics, intuitively in contraposition to an “old” tectonics. this linguistic aspect has been pointed out in the already mentioned work by wu & hu (2019), who highlighted that “the word neotectonics originated from greek, and refers to ‘the youngest, latest or on-going crustal tectonics or movement process on the earth', i.e., the latest tectonic processes in geological history. therefore, this term inherently does not specify a period or limit in time, which may cause confusion in application due to different understandings”. whichever definition is used, nonetheless, neotectonics is evidently connected to the study of the faults that can generate earthquakes, as they are “the” active faults. this conceptual premise is necessary to introduce the present work, since it deals with the experience on neotectonics matured in italy, starting from the “lesson” learned during the italian national project “progetto finalizzato geodinamica” (“italian geodynamics project”, hereinafter pfg), conducted in the 1970s and 1980s with methods, procedures, and results summarized by carlo bosi(1) in 1992, as coordinator of the sub-project “neotectonic map of italy”. our goal is i) to describe the perspective of neotectonics defined in the above-mentioned italian project, ii) to provide a solution to the ambiguity in the use and definitions of the term, and iii) to show the unreplaceable effectiveness of neotectonics for studying active and seismogenic faulting in italy. the italian seismotectonic framework is particularly suitable for this aim. indeed, in regions characterized by high deformation rates (in the order of few-to-several centimeters per year) such as those including plate boundaries, faults may display unmistakable geological evidence of activity and a “simple” paleoseismological approach may suffice to investigate them. on the contrary, in intraplate tectonic domains like indeed italy, characterized by i) slow rates of deformation, ii) recent inception of the current tectonic regime, iii) faint superposition of active faults on the structural framework inherited from past tectonic phases, and iv) exogenous modification of the landscape with rates comparable to those related to tectonics, the detection and definition of active faults are more complex and the paleoseismological approach may result not sufficient to define appropriate seismotectonic pictures. we will show that in such tectonic domains, neotectonics can result fundamental to define settings of active faults, once the methodological perspective we discuss is adopted. after a paragraph dedicated to the definitions of “active tectonics”, “active faults” and “capable faults” over the past decades, we present the italian experience on neotectonics. afterward, we will discuss the implications of applying neotectonics to evaluate the time interval required for assessing active and capable faulting in the context of the italian tectonic framework for engineering practices. subsequently, we will examine some examples to demonstrate the effectiveness of neotectonics in assessing active and seismogenic faulting, as well as the negative consequences of not applying. in the discussion and concluding remarks, we will summarize the key aspects of the italian experience in neotectonics, from which general implications will be derived, related to the investigation of active and seismogenic faults in any seismotectonic framework. 2. defining “active tectonics”, “active faulting”, and “capable faulting”: a critical review scientific papers, technical reporting, and guidelines for engineering practices include a multitude of definitions regarding the categories mentioned in the title of this section, partly reported in appendix a (only available in the online version of the manuscript). the long list suggests that a commonly agreed-upon view is lacking. the plethora of definitions allows us to derive some general aspects and criticalities that probably did not permit to get to a commonly accepted view of what defines active tectonics and active faulting to date: 1) characterizing active tectonics and active faults can 206 --------------- 1) carlo bosi (1935-2018), geologist, has been director of centro di studio per la geologia tecnica and istituto di ricerca sulla tettonica recente of the (italian) national research council (cnr); coordinator of the neotectonic map of italy (within the framework of progetto finalizzato geodinamica sponsored by cnr); president of aiqua (italian association of quaternary studies). among the first italian researchers, he used quaternary geology to investigate active faults in the central apennines, greatly contributing to the methodological advancement and the progress of knowledge in this field. his works made between the seventies and the nineties of the past century are still fundamental sources of geological data and milestones for the analytical approach that deserve to be considered still valid and irreplaceable. the authors owe him their personal expertise in the arguments discussed in the present paper. not solely rely on an investigation approach based on instrumental monitoring (such as instrumental seismicity and/or modern geodesy, and/or satellite remote sensing), aimed to define what are the current effects of ongoing tectonic forces. 2) the key role of the chronological constraints to define current activity usually emerges from the different scientific and technical contributions; the various definitions are based upon time intervals that are influenced by local geological and tectonic characteristics (e.g., high slip rates and/or short recurrence intervals of fault activation) or by the lifespan of engineering infrastructures (from residential buildings to dams to nuclear plants), or by the available methods used by geologists to chronologically constrain tectonic activity or inactivity. 3) it is evident that a comprehensive geological approach is necessary to assess tectonic/fault activity, as it may take place over time intervals typical of the geological analysis, i.e., on the scale of thousands or hundreds of thousands of years. 4) it is also evident that a definition of “active fault” that is suitable for one specific territory or tectonic framework may not be as applicable or effective in another tectonic context, i.e., a general and comprehensive time interval to assess fault activity cannot be determined. since the 1970s, alternative approaches have based the definition of tectonic and fault activity on the characteristics of the ongoing tectonic regime. regimes vary from one region to another and are characterized by different kinematics of faults, deformation rates, and recurrence time of fault actvation (slemmons & mckinney, 1977; muir wood & mallard, 1992). according to slemmons & mckinney (1977), a fault can be considered active if it activated during the current seismotectonic regime and, consequently, may be responsible for future dislocation events. within this light, an active fault is essentially the manifestation of the current tectonic regime, which serves as the underlying cause, as the “engine” for the fault activity. fault activation during strong earthquakes and the geological traces of its movements at the surface represent direct and visible evidence of ongoing tectonic activity, i.e. of the ongoing tectonic regime. therefore, since the concepts of “active tectonics” and “active faulting” inherently relate to the characteristics of the ongoing tectonic regime, it becomes clear that defining this regime is essential to assess active faulting. furthermore, considering that the characteristics of the tectonic regime differ from one region to another, it follows that the definition is inherently tied to specific territories. each region has its own time span within which a given fault must show evidence of movements in order to be considered active. the current tectonic regime represents the most recent phase of the tectonic evolution in a given region. by defining this history, using methods and techniques typical of the geological investigation, we can uncover the ongoing tectonic process in an area and, importantly, we are able to determine when it began. on these grounds, the time interval for investigating tectonic behavior appears crucial. it must be sufficiently long to “sample” significant variations in deformation rates, kinematics, and style of tectonic deformation (e.g., neotectonics for investigating active faults from extensional to compressive tectonic regime). on the whole, understanding of the current tectonic regime and, therefore, the characteristics of active tectonics implies the analysis of geological and tectonic events, as well as the structural evolution of areas, regions, faults or folds over time intervals as long as to guarantee a geologically wider view of the tectonic behavior. by taking a broader geological perspective, we can gain a comprehensive understanding of the shortterm tectonic behavior, which provides the ground to assess hypotheses on the future behavior of faults. in italy, this type of information is obtained from the analysis of time spans including late pliocene and quaternary. similar conclusions about the necessity to define active fault settings, i.e., those faults that are genetically related to ongoing tectonic regimes through the reconstruction of the kinematic evolution, have to be also drawn for the capable faults, considering that, on the whole, they can be included in the category of the active faults. indeed, there is not a capable fault that cannot be classified as an active fault (while, by contrast, not all active faults may be considered as capable). in short, capability cannot be separated from the concept of activity, because activity connects to the engine that moves a (an active) capable fault, that is, tectonics. this is clear from iaea ssg-9 (iaea, 2022), one of the main references for the definition of capable faults, whose content has been summarized in appendix a. there, following the well-known paradigm in which a capable fault is “an active fault that has a significant potential for displacement at or near the ground surface”, iaea defines three conditions to assess capability, i.e., i) the evidence of past movement (e.g., significant deformations and/or dislocations) within such a period that it is reasonable to conclude that further movements at or near the surface might occur over the lifetime of the site or the nuclear installation; ii) the structural link of a fault with a known active fault; iii) a relationship with a seismogenic structure which may cause earthquakes with magnitude large enough to trigger fault motions in a certain area. criterion 1 indeed highlights the significance of considering a geological time period that is sufficiently long to account for the style and rate of deformation. this time is directly related to the current tectonic regime and the age of its inception. criterion 2 introduces the concept of a structural relationship between a given fault and another fault that satisfies criterion 1 to assess the capability of the former. however, criterion 2 does not provide a clear definition of what constitutes a "structural relationship”. in this regard, for example, “soft linkage” is a kind of “structural relationship” among fault segments, but this kind of relation does not imply that the kinematic characteristics on one segment can be applied to the others, since “soft linkage” implies kinematic independence (e.g., walsh & watterson, 1991). moreover, criterion 2 is ultimately dependent on criterion 1, thus reinforcing the importance of understanding of the ongoing tectonic regime. regarding the third criterion, although iaea ssg-9 does not explicitly specify the relationship a fault should have with a seismogenic source to be considered capable, the definition of the seismotectonic framework of which a seismogenic source is part of a region relies once again on understanding the ongoing tectonic re 207 gime and the relevant time span for this definition. comparably to criterion 2, also criterion 3 is implicitly associated to criterion 1. in summary, the concept of fault capability and its determination relies on considering time as the primary factor to define the ongoing tectonic setting. indeed, the other criteria mentioned for defining fault capability are not independent of a chronological criterion. the assessment of fault capability cannot be considered in isolation from activity. therefore, while a fault can be active but not capable, a capable fault is inherently active, that is, connected to the causative tectonic regime. fault capability and activity are therefore interconnected concepts that cannot be dissociated from the chronological criterion. therefore, criteria 2 and 3 of iaea ssg-9 are actually sub-criteria with respect to criterion 1. hence, if the definition of the tectonic regime is crucial to fully characterize the geometric and kinematic characteristics of seismogenic active and active/capable faults, connected to this regime, the next fundamental step is “how” to effectively analyze the tectonic regime. in this regard, the italian experience on neotectonics offers unreplaceable insights, particularly through the theoretical and epistemological synthesis proposed by carlo bosi discussed in the following section. 3. neotectonics in italy between the 1970s and the 1990s the studies on neotectonics in italy received great impulse and formal organization in the second half of the 1970s, within the framework of the italian geodynamics project sponsored by the national research council (the above mentioned pfg). the aim of this great initiative of research was the evaluation and reduction of seismic and volcanic risks, through the collaboration of geologists, geophysicists, seismologists, and engineers. pfg is still considered as the greatest italian effort of multidisciplinary studies, as it involved more than 1,000 scholars from universities and research institutes, organized in sub-projects and working groups, with expertise ranging from the different fields of geology to seismology, volcanology, and seismic engineering (barberi, 2020; stucchi, 2023, personal communication). it produced an impressive number of scientific publications and reports, technological products, and operating manuals. the most famous releases, still used today as milestones of the research history, are the “structural model of italy” (bigi et al., 1990), the “neotectonic map of italy” (ambrosetti et al., 1987), an earthquake catalog (postpischl, 1985; see camassi, 2004 for a review of the italian catalogs and a description of the pfg catalog), and the first seismic classification of the italian territory (cnr-pfg, 1980a). according to barberi (2020), pfg had the merit to lay the foundation of a culture of prevention in italy regarding seismic and volcanic risks (an example of the pfg effort in this perspective is the intervention of g. grandori and f. barberi at the senate of the republic following the 1980 earthquake in southern italy; grandori & barberi, 1980). the sub-project dedicated to the neotectonic map of italy was coordinated by carlo bosi, a quaternary geologist of the national research council. the progress of the research is testified by various publications (e.g., cnr-pfg, 1980b; 1982), permitting to understand the characteristics of the italian approach to neotectonics and still having the role of invaluable data sources. the range of definitions available worldwide for neotectonics (some and significant examples have been reported above) makes the description and discussion of this approach necessary to estimate the current effectiveness of the methods adopted in italy. in this perspective, an important document is represented by the introduction to the workshop “la neotettonica in italia a dieci anni dalla fine del progetto finalizzato geodinamica” (neotectonics in italy ten years after the italian geodynamics project), held in rome on 2nd-3rd march 1992 (bosi, 1992). the text was written in italian, and, in the following lines, we will propose the translation of those parts (within quotation marks and in italic, bold italic for the most important passage, in our text) that cast light on methodological aspects. in his contribution, bosi firstly retraced the state of the art at the beginning of pfg, in the half of the 1970s, mentioning the general belief of that time, i.e., “that the formation of the alpine and apennine chains ended in the miocene or in the lower pliocene and that quaternary tectonics, in the few areas where evidence was collected, only represented a dampening consequence of older events. the few data reported in the sparse works dealing with this topic were considered as anomalous traces of crustal motions rather than elements of a general deformative pattern”. considering this starting point, “the neotectonic map of pfg represented an important, but necessarily defective and incomplete, first step towards an appropriate definition of the plio-quaternary tectonic evolution in the italian territory”. after a long discussion concerning the limits of the neotectonic map, the introductory text to the workshop goes on with the second section dedicated to the research in the decade following the end of pfg, i.e., during the 1980s and the beginning of the 1990s. according to bosi, a key-role in the growth of the studies in neotectonics in that period was played by structural geology “which, in different ways, positively influenced the development of research […] this occurred in a way which i may define ‘direct’, i.e., by stimulating scholars working out of neotectonics to follow a line of reasoning in terms of tectonic evolution (through ‘phases’ related to specific states of stress). other effects of structural geology may be defined ‘indirect’, since growth of this discipline clearly demonstrated the impossibility to define the tectonic evolution of the mountain chain areas solely based on structural studies. this limit is due to the scarcity of plioquaternary deposits which may represent the object of (typical, we may add) structural analyses”. two important aspects derive from this passage: i) a first (but not indepth) warning to the main role played by the tectonic evolution (better defined in the next) and ii) the qualities and limits, if taken alone, of structural geology in contributing to neotectonics. as for the limits mentioned in point “ii”, the warning was probably motivated by the tendency of researchers to get around the difficulties to perform serious (and time-consuming) studies by integrating different disciplines. the third and last section, dedicated to “current issues and perspectives”, is the most important for the methodological aspects regarding neotectonics. a funda galadini et al. 208 mental discussion concerns the meaning of the term “neotectonics”, as bosi recognized that “…a clear and widely accepted definition is not available. the problem is by no means trivial, since the choice of one or another definition (neogene tectonics? quaternary tectonics? last phase of the tectonic evolution? neotectonics as a field of research clearly distinguished from paleotectonics? etc.) has important consequences both on the content of the research related to neotectonics and in its inclusion in one or another disciplinary field of earth sciences”. it is here that bosi produces, synthetically and successfully, a clear definition of neotectonics, which appears particularly effective for the investigations in the italian territory: “a more serious proposal is the attribution of an essentially practical content to the term. in this perspective, neotectonics may be intended as an integrated set of studies with the aim to define the plio-quaternary tectonic evolution through a temporal scan of hundreds of thousands of years. the noteworthy aspects of this definition are represented by the evolutionary perspective and by the chronological framework on which the investigations should be based. this aspect may give its own individuality to neotectonics and define its nature greatly interdisciplinary” [please note that the “normal style” has been here adopted for terms that bosi published in italic]. this passage expresses the evolutionary perspective, the 4d view, which animated the studies merged in the contributions to the neotectonic map of italy (e.g., cnrpfg, 1980b; 1982) and in the map itself (ambrosetti et al., 1987). the reconstruction of the kinematic evolution is necessary “to define the current tectonic regime and the age of its inception. this definition has a main role in seismotectonic evaluations, since it firmly constrains detection and characterization of seismogenic structures”. this explicitly defines the consistency of the faults, which cause the earthquakes with the current tectonic regime and finds comparable approaches in other contributions of the past (as in the above-mentioned works of slemmons & mckinney, 1977; muir wood & mallard, 1992). the definition proposed by bosi has operational effects, since i) a structural setting related to the current tectonic regime includes the active faults and excludes the inactive ones (even those apparently consistent with the ongoing tectonic regime but which became inactive, for different reasons, such as fault abandonment and displacement re-organization owing to interaction of fault segments in a fault array; on this aspect see the works of gawthorpe & leeder, 2000; cowie et al., 2000; finch & gawthorpe, 2017) and ii) the definition of a certain fault as active implies that it must be consistent with the current tectonic regime. point i) may represent an answer to the third criterion expressed by iaea for fault capability, i.e., the attribution of capability to a fault affecting an area where a seismogenic structure may cause earthquakes with magnitudes large enough to trigger motions on other faults. this definition does not specify the relationship between a fault and a seismogenic source and implies that each fault kinematically and geometrically compatible with the active seismotectonic setting may be capable, using a precautionary approach. the view of neotectonics expressed in point i) allows to overcome this cultural bias, as it not only helps defining when a fault is active and capable but also allows to verify when it is not (or no longer) active and capable. however, in the same intervention, bosi underlined the tendency to underestimate the importance of the “evolutionary perspective” intrinsic to neotectonics “also due to a certain (perhaps excessive) superficiality which feeds the assumption of a steady tectonic regime also during long time intervals”. in 1992, it was already clear that studies in this complex field can be successful only by “processing data from different disciplines such as structural geology, stratigraphy and geomorphology (with integration of data from paleo-pedology, pale-ecology, …), sedimentology, geodesy and geochronology”. the very long and difficult investigations concerning neotectonics may suggest defining recent fault activity by taking shortcuts, i.e., by adopting superficial and hastier approaches. however, results of similar procedures “cannot produce chronologically well-defined pictures of plio-quaternary tectonic evolution […] and may give, at best, the scheme of a whole geological structure related to the entire chronological interval above mentioned”. for example, also inactive normal faults with a displacement history limited to pliocene-early pleistocene may be considered active with an approach avoiding the reconstruction of the fault history. a presumed evidence of fault activity considered by bosi as a shortcut is represented by the interpretation of bedrock fault scarps as sufficient condition to assess very recent activation: “in most cases, the elements composing the different settings, when viewed alone, are purely circumstantial and may result (and often result) insignificant as for the perspectives of neotectonics. for example, this occurs for quite common geological features as fault scarps, whose origin is often related to both tectonic motions and morpho-selective processes”. however, the role of these geomorphic features as indicators of late pleistocene-holocene motions raises continuously in the geological literature (e.g., piccardi et al., 1999; palumbo et al., 2004; roberts & michetti, 2004; papanikolaou et al., 2005; tesson et al., 2016; mildon et al., 2022). in the conclusive part of this introduction to the 1992 workshop, bosi indicated some of the perspectives of the future research. among those of thirty years ago, two points appear still topical, regarding deontological issues and applications, which are strictly related: i) “the first concerns the necessity to favor closer confrontations among scholars, also to hinder the tendency, sometimes evident in published works, to propose evaluations and deductions unsupported by data. in this perspective, i want to underline that, in the field of neotectonics, the complexity of the cognitive process itself makes the serious scientific dialectics necessary”; ii) “the other aspect concerns the opportunity to promote greater attention for neotectonics in planning major engineering works. the importance of neotectonic estimations, presently almost non-existent, should drastically increase, at least for those elements of active tectonics (mainly faults) which may affect the safety of the works”. it seems clear that the reliability and earnestness quoted in the first point represent an unmissable prerequisite for the massive use of geological data invoked in the second point. in the perspective of the present paper, the most important concept defined in this section, as derived from 209 neotectonics for investigating active faults bosi’s contribution, is certainly the correspondence of neotectonics with the integrated set of studies due to different disciplines, having the aim to define the recent tectonic evolution with decisive consequences as for seismotectonics and the identification of active and capable faults and seismogenic sources (fig. 1). in the next sections we will propose case studies which illustrate the application of the “evolutionary criteria” above discussed and the negative consequences of the non-application. 4. the adoption of bosi’s approach to neotectonics in the study of active and capable faults in italy the neotectonics definition by bosi, with its evolutionary character, is hinged on “time” for investigating the tectonic evolution of a region, to assess the ongoing tectonic regime and to ultimately define fault activity and capability (see previous section). quaternary geological investigations, with their multidisciplinary nature, play a pivotal role in neotectonics, by providing the chronological foundations through the integration of disciplines such as sedimentology, stratigraphy, geomorphology, and various dating methods (fig. 1). two active tectonic domains mainly characterize the italian territory: i) the axis of the apennine chain is affected by extensional tectonics, while ii) the outer sectors of the northern-central apennine chain and the southern sectors of the alps are characterized by compressive tectonics. based on bosi’s perspective on neotectonics, i.e., considering the recent tectonic evolution of the italian territory, galadini et al. (2012) proposed that, in the extensional domain of italy, a fault can be considered active and capable if it exhibits evidence of activity since the middle pleistocene unless it is sealed by deposits or landforms not younger than the last glacial maximum (henceforth lgm; about 25-15 kyr). middle pleistocene was chosen since the extensional tectonic regime attained its present configuration in that time. the choice of the lgm is supported by two key factors: i) considering slip rates and recurrence intervals of the italian normal faults (derived from paleoseismological studies, e.g., galli et al., 2008), the last 25-15 kyr define a sufficiently long time span to assess inactivity once lack of motion is documented by geologic and geomorphic evidence related to the lgm; ii) the lgm is the last period of the recent geological history responsible for the significant morphogenetic processes (erosion and sedimentation) driven by climatic forcing. the effects of these processes, including the accumulation of sedimentary sequences and the formation of depositional/erosional surfaces, are pervasive throughout the italian landscape, making them valuable for fault activity (or inactivity) assessment. as for the compressive domain, galadini et al. (2012) proposed that a fault can be considered active and capable if it shows evidence of movement throughout the entire quaternary. differently from the extensional domain, the choice of the entire quaternary derives also from an operational criterion. indeed, many italian thrust faults are blind, and commercial reflection seismic profiles are necessary for their study. the commercial profiles usually have limited resolution as for the detection of the recent stratigraphic units, and a whole, undifferentiated quaternary is generally depicted as the most recent stratigraphic unit. as in the case of the extensional fig. 1 block diagram showing the conceptual path linking neotectonics to the identification of active and capable faults and to seismogenic sources. galadini et al. 210 tectonic domain, to be considered inactive, a quaternary reverse/thrust fault should be sealed by deposits and/or landforms not younger than the lgm, based on the same geological rationale as the extensional faults. importantly, very similar chronological references are adopted by the above-mentioned italian guidelines for seismic microzonation (technical commission for seismic microzonation, 2015). indeed, these guidelines state that a fault should be deemed potentially active and capable if it exhibits evidence of activation after the middle-late pleistocene. moreover, a fault should be deemed active and capable if it shows evidence of activity over the past 40 kyr. this period is similar to the lgm defined by galadini et al. (2012). however, the past 40 kyr represent a sort of technical constraint, being related to the limit of radiocarbon dating applicability, while the use of the lgm in the work by galadini et al. (2012) derives from geological and seismotectonic evidence. moreover, in the guidelines for microzonation, the last 40 kyr are to assess activity in case of displacement of younger deposits and landforms, while the lgm is proposed by galadini et al. (2012) to argue fault inactivity if deposits and landforms having that age or being older seal the fault. 5. case studies of best practices in neotectonics and negative consequences of nonapplication in the following lines, we will deal with some case studies from the central apennines of italy to highlight the practical value and significance of applying neotectonics as a procedure to assess active faulting. 1) as mentioned above, the presence of bedrock fault scarps is sometimes considered in itself a reliable geomorphic indicator of fault activity. this view assumes that the exposure of bedrock fault scarps results from fault activation, particularly in extensional tectonic environments. in the past two decades, researchers employing this view have utilized methods to date the exposure of fault planes (e.g., palumbo et al., 2004; tesson et al., 2016). these dating methods rely on the accumulation of cosmogenic nuclides on fault planes, which begins after fault plane exposure, presumably caused by a surfacerupturing earthquake on the considered fault. however, this perspective is not universally accepted in the scientific literature, as other studies suggest that fault scarps may be exposed also due to nontectonic processes such as erosion or gravitational phenomena (e.g., bosi et al., 1993; galadini & messina, 2001; galadini, 2006). this viewpoint challenges the confidence in the method and its ability to soundly assess fault activity solely based on fault plane exposition. an interesting example of this scientific debate concerns the wne-ese trending fault that bounds a central apennine intermontane basin to the ssw, where the village of leonessa is located (fig. 2). the leonessa fault has been the object of various studies that have resulted in still conflicting interpretations regarding its activity. on one hand, some authors (e.g., michetti & serva, 1990; cello et al., 1997; roberts & michetti, 2004; papanikolaou et al., 2005) suggested that the fault plane exposure at the base of the fault scarp, in a sector located ssw of the village of leonessa, resulted from repeated fault slip episodes occurred after the last glacial maximum. based also on the height of the exposed fault plane, some of the mentioned works derived fault slip rate and maximum credible magnitude of earthquakes that the leonessa fault could generate, i.e., approximately mw 6.5. on the other hand, in syntheses of active faults of the central apennines (barchi et al., 2000; galadini et al., 2001), the activity of the leonessa fault is indicated as debated, since different research groups which contributed to these syntheses have not reached a consensus on the late pleistocene-holocene activity of the tectonic structure. fubelli et al. (2008; 2009) performed geological and geomorphological field observations in the whole leonessa basin and along the fault-related slope, aimed at defining the quaternary evolution of the adjacent basin from a neotectonic perspective. the authors recognized that the exposure of the leonessa fault plane is very localized and that all of the sites where the plane crops out coincide with sectors of the fault scarp where nontectonic processes occur, e.g., erosion or landsliding of the scree deposited at the base of the limestone scarp. furthermore, the authors argued that the fault is sealed by sets of alluvial fans dating back to the middle and late pleistocene (which is a time span long enough to consider the fault not capable, according to the chronological criteria defined by the above described work of galadini et al., 2012). hence, fubelli et al. (2009) did not rule out that the leonessa fault may have been active in the early stages of the central apennine extensional tectonic regime, i.e., in the early pleistocene, but its activity strongly reduced or even ceased since the middle pleistocene. the above described scientific debate holds significant implications for assessing the seismic potential associated with the leonessa fault. according to the former viewpoint, this tectonic structure could potentially be responsible for large-magnitude earthquakes (up to about mw 6.5). conversely, according to the latter viewpoint, the leonessa fault may not (or no longer) be able to produce earthquakes large enough to produce surface faulting as the magnitude threshold for producing surface faulting, on the apennine extensional active faults is around mw 5.5-6 (e.g., michetti et al., 2000; falcucci et al., 2016). following bosi’s (1992) viewpoint on the neotectonic significance of bedrock fault scarps, discussed in a specific work in 1993 (bosi et al., 1993), the authors highlighted the challenges associated with interpreting bedrock fault scarps from a neotectonic perspective. they pointed out that various processes can contribute to the exposure of fault scarps. while some scarps are clearly of tectonic origin, others may result from unearthing of buried and inactive structures due to landslides or erosion, and other from a combination of tectonic and non-tectonic processes. the authors emphasized that a comprehensive analysis of bedrock fault scarps requires a detailed examination of their stratigraphic, structural, and geomorphological settings, i.e., a thorough neotectonic investigation in the territory affected by the fault. this approach is essential to ensure reliable interpretations concerning the origin of these geomorphic features and, consequently, regarding the seismic potential associated with a specific fault. 211 neotectonics for investigating active faults from a broader perspective, bosi's statements suggest that even fault scarps exposed by tectonic fault slip in continental environments should be approached with caution when conducting active faulting analyses based on the exposure and dating of the fault planes. in continental environments, particularly, deposition is naturally intermittent due to climatic influences. as a result, erosional and depositional processes can periodically conceal and expose faults, and the extent and duration of the related effects remain uncertain. consequently, fault planes, even if active, may undergo unknown episodes of exposition and burial, thereby influencing the local fault scarp exhumation history and thus potentially affecting the tectonic significance of fault exposure dating. hence, as the occurrence of these phenomena cannot be never completely ruled out, neotectonics helps to place in a safe position from these uncertainties, as this approach is focused on the definition of the whole tectonic history of a given fault, allowing to overcome the above described unknowns. 2) the sulmona basin, in the abruzzi region of the central apennines, is a tectonic depression whose formation and evolution throughout the quaternary has been strongly shaped by the activity of the mt. morronesulmona normal fault (hereafter mmf). the mmf is a nw-se trending and sw dipping basin-bounding normal fault, widely recognized as an active and capable fault (e.g., gori et al., 2011). it represents the surface expression of a major seismogenic source potentially responsible for earthquakes with magnitudes up to 7 (e.g., bordoni et al., 2022). the studies above mentioned have provided evidence of displaced continental deposits spanning the whole quaternary along the fault. archaeoseismological and paleoseismological investigations revealed that the last episode of activation occurred approximately 1,800 years ago (ceccaroni et al., 2009; galli et al., 2015). the mmf consists of two major branches that affect the southwestern slope of mt. morrone, with the eastern branch located at the intermediate sector of the slope and the western at the base of the relief (fig. 3a). the excavation of a building foundation in the fault hanging wall, a couple of km west of the western fault branch, uncovered the alluvial plain deposits widespread in the sulmona basin. the depositional top surface of this sequence consists of a wide sub-horizontal terraced landsurface, known as the “sulmona surface”, representing an ancient paleo-base level of the basin. the uppermost portion of the sequence and the depositional top surface have been aged at about 30-40 kyr bp, through chronostratigraphic, geomorphic and tephro-stratigraphic analyses supported by radiometric dating (e.g., gori et al., 2011; galli et al., 2014). the rivers that fed the alluvial deposits are presently embedded in the “sulmona surface”, which is suspended over the thalwegs by some tens of meters. the analysis of the excavation walls revealed a shear zone consisting of several shear planes affecting the entire sequence, showing a normal sense of motion (fig. 3b, c). the excavation permitted a 3d view of the shear planes, showing that they mostly stroke in the n-s and nw-se direction, which is oblique to the orientation of mmf. the up-to-5-m high excavation walls allowed us to investigate the attitude and characteristics of the shear fig. 2. geological map of the southern margin of the leonessa basin. as for the legend, see the original text and figures at the website https://sisma2016data.it/faglie-attive-e-capaci/ galadini et al. 212 planes some meters at depth, showing that they terminated a few meters below the surface, with the lowermost alluvial layers showing no displacement (figs. 3d, 3e). moreover, the amount of offset decreased with depth. in one instance, the deepest sandy layer displaced by the shear plane exhibited varying thickness across the plane, suggesting that it underwent differential compaction after deposition. this example shows that basing on paleoseismological trenching and the analysis of the related fewmeters-high outcrops these non-tectonic shear planes might have been conceivably interpreted as composing a tectonic shear zone related to the mmf. by contrast, the outcrop shown in figure 3 showed that the shear planes are the result of geotechnical processes, such as the differential compaction of the alluvial layers or liquefaction. as in most cases it is not possible to dig paleoseismological trenches so deep to obtain outcrops as high as that represented in figure 3, the investigated case suggests caution in attributing systematically a conclusive diagnostic value to just paleoseismology. but more importantly, geological observations apfig. 3 a) a) view from south of the sulmona basin, showing the south-western flank of mt. morrone and the traces of the active normal fault splays. b) c) d) e) wall of the investigated excavation; the yellow line marks the investigated shear planes; the blue dashed line marks the unfaulted sand layer. 213 neotectonics for investigating active faults pear fundamental to discern the nature of the shear planes even if outcrops so high are lacking. indeed: i) the reduction of displacement with depth contradicts the expected behavior of a fault rupture caused by coseismic slip propagation from hypocentral depth to the surface. indeed, if the observed shear planes were associated with surface faulting of an active, capable, and seismogenic fault, the offset should have increased with the age of the deposits. the examined case demonstrates a different pattern, where the displacement decreases with depth. this inconsistency strengthens the argument that the observed shear planes are not related to surface faulting. in this perspective, it must be underlined that the geological evidence of displaced deposits along the mmf branches (e.g., gori et al., 2011; galli et al., 2014) showed that offset affecting early pleistocene deposits is larger than offset of younger (up to the holocene) deposits. this confirms that displacements of the quaternary units along the mmf result from the primary (sensu iaea tecdoc 1767, 2015) upward propagation of the coseismic rupture, whilst the displacement determined by the described shear planes in the investigated excavation cannot be related to tectonic faulting. ii) even more importantly, evidence of displacement or geomorphic anomalies due to fault activation does not affect the “sulmona surface” across the investigated shear zone. the landsurface displays a sub-horizontal attitude with the original, gentle dip towards sw. the lack of displacement or disruption in this landform suggests that the uppermost portion of the alluvial sequence has not been affected by tectonic displacements since at least 30-40 kyr bp. this reinforces the conclusion that these shear planes, even if they were of tectonic origin which they are not should not be considered active and capable according to the chronological criteria proposed by galadini et al. (2012) and the italian seismic microzonation regulation. apart from the non-tectonic origin of the observed displacement, the discussed case indicates the necessity to include a single piece of evidence of recent displacement in the wider perspective of the geological and tectonic evolution of an area defined by neotectonics. this perspective, in the specific case here represented, defines inactivity of the detected shear planes. 3) the seismic sequence that occurred in central italy in 2016 included three mainshocks: the first, of mw 6.1, on august 24; the second, of mw 5.9, on october 26; and the third and strongest one, of mw 6.5, on october 30, as well as a sequence of aftershocks that lasted for years. it has been caused by the activation of extensional tectonic structures (e.g., tinti et al., 2016; chiaraluce et al., 2017; cheloni et al., 2017; 2019), i.e., the mt. vettore -mt. bove fault (hereafter mvbf), to the north, and the laga mts. fault (hereafter lmf), to the south. these faults had been extensively studied prior to the sequence by geological investigations and were already defined as active and capable (e.g., galadini & galli, 2003). specifically, paleoseismological analyses conducted along their surficial expression revealed that they activated probably more than 1,000 years ago. the faults have been defined able to generate surface-rupturing earthquakes, of magnitude around mw 6.5-6.6. this has been unfortunately confirmed by the seismic sequence of 2016. detailed geological investigation along the lmf allowed galadini & messina (2001) to identify two distinct sectors of the fault with substantial differences, despite it seems a single, long fault-related mountain front. the authors identified a southern fault section, about 20 km long, located in the area of campotosto village, that exhibits an evident fault scarp at the base of the laga mountains’ sw slope. sequences of alluvial fans, alluvial terraces and slope deposits, late pleistocene to late holocene in age, are evidently displaced along this fault. on the other hand, the northern sector of the laga mountains’ sw slope, affected by the amatrice fault section, does not display an evident scarp due to recent activity and no late quaternary deposits or landforms are here displaced. according to galadini & messina (2001), the northern amatrice section of the lmf did not control the late quaternary evolution of the adjacent basin, and the fault here displayed no or subtle evidence of capability (falcucci et al., 2018). consequently, galadini & galli (2003) and falcucci et al. (2018) issued that the southern fault can be considered active and capable, and potentially responsible for m∼6.6 earthquakes; the northern amatrice fault, instead, was supposed not capable, that is, not able (or no more able) of producing surfacerupturing earthquakes, that is, earthquakes not larger than mw∼6. this segmentation of the seismogenic faults in the area was further supported by more recent investigations that defined the geological evolution of the region between the mvbf and the amatrice and campotosto sectors, in the perspective of neotectonics (falcucci et al., 2018; fig. 4). the 2016 central italy seismic sequence aligns with the seismotectonic setting above described. indeed, the seismogenic rupture of the mainshock on august 24, 2016 occurred both in the southernmost section of the mvbf and in the amatrice fault. however, surface faulting was only observed along the former and not along the latter. seismological and geodetic coseismic data (e.g., tinti et al., 2016; cheloni et al., 2017) confirmed the presence of two distinct ruptures, the larger one being consistent with the southern part of the mvbf, with a seismic moment corresponding to a magnitude of mw 6.1. the smaller southern rupture, consistent with the amatrice fault, released a seismic moment corresponding to a magnitude of mw 5.8-5.9, not enough to generate surface faulting. these observations hence confirmed the long-term geological data. moreover, it is worth noting that, as outlined by falcucci et al. (2018), the aftershocks following the mainshock ended towards the south where the geological separation of the amatrice fault section from the campotosto section occurs. this further supports the segmentation based on neotectonic analyses and the related inferences on the different seismic potentials and capability. 6. discussion and concluding remarks the assessment of the two main hazards associated with seismogenic faults, namely ground shaking and/ or surface faulting, entails the comprehension of the on galadini et al. 214 going tectonic regime to which structural settings of active faults are genetically connected. various authors (such as slemmons & mckinney, 1977; muir wood & mallard, 1992) have proposed that the attribution of activity to a fault is related to its consistency with the ongoing tectonic regime in each region. the grasp of this regime, in turn, implies the reconstruction of the tectonic history which may define cases like those summarized in the sketch of figure 5. among the many but not univocal definitions and declinations, neotectonics, as defined by bosi (1992), is a procedure whose aim is the reconstruction of the tectonic evolution and the definition of structural settings consistent with the current tectonic regime. this evolutionary perspective represents the strength of neotectonics proposed by bosi (1992), as a procedure going beyond the "static" multidisciplinary twoor threedimensional analysis of a specific territory or fault. indeed, it is by introducing evolution through time that neotectonics allows to assess whether a fault, a fault segment, or a fault section, also apparently consistent (geometrically and kinematically) with the current tectonic regime, can be considered active. in this perspective, one of the significant epistemological outcomes of neotectonics is the definition of an active and capable fault (see below). it should be noted that we always refer to "capable" faults in conjunction with "active" because, as explained in section 2, capability, regardless of the specific feature being considered (such as discrete faulting, primary or secondary, localized folding, or broadband folding), cannot be genetically separated from fault activity, as the “engine” that moves capable faults is inherently the tectonic regime. on the whole, the main conclusive remarks emerging from the previous pages may be summarized in the following points. 1) it is evident that, in terms of chronology, each region, each territory, with its own tectonic evolution, has its specific chronological criterion for defining an active fig. 4 a-e) reconstruction of the geologic and structural evolution from the miocene to the quaternary of the epicentral area of the 2016 seismic sequence in central italy; f) consequent segmentation of the seismogenic faults (modified from falcucci et al., 2018). 215 neotectonics for investigating active faults fig. 5 reconstruction of geological and structural evolutions since the late pliocene of a typical normal fault-bounded relief in the central apennines. 1) active fault and related shear zone, 2) inactive thrust fault, 3) plio-quaternary deposits, 4) and 5) pre-quaternary bedrock, 6) rupture along the active and seismogenic fault in the active extensional tectonic regime. the example depicted in the first four sketches (a) may define the tectonic history of the magnola mountains fault, in the fucino basin area (central apennines, abruzzi region), according to reconstructions proposed by various authors (gori et al., 2007; galli et al., 2012); the example of the last two sketches (b) may represent the tectonic history of the colfiorito fault system in the umbria region (central apennines), according to the reconstruction by messina et al. (2002). galadini et al. 216 fault. only after establishing this criterion can any further assessment of fault activity and capability be conducted. thus, from a broader perspective, a fault can be considered active and capable if it exhibits evidence of activity within a time frame that is consistent with the ongoing tectonic regime of the region. by contrast, inactivity derives from the evidence that a certain fault is sealed by deposits and/or landforms not younger than a time span (from the present) whose duration includes a significant number of seismic cycles. this brings together another fundamental aspect, in an engineering perspective, directly connected to the concept of capability: since not all of the faults or fault segments that are structurally consistent with the ongoing tectonic regime (as for geometry and kinematics) are necessarily active and capable (as in the case of the amatrice fault), it implies that it is necessary to operate in the manner that fault activity must be proven, through neotectonics. the sole “structural” and “seismotectonic” criteria may not suffice to hypothesize fault activity and capability. in this regard, even considering a precautionary approach (especially in an engineering perspective), one may otherwise risk to deem a fault active (and capable) on just circumstantial factors. 2) the sole use of paleoseismology might not permit solving the problem of the causative factors of a displacement that occurred along a shear plane. this is because paleoseismological studies, which focus on specific sites, can be limited in their ability to provide a comprehensive understanding of the broader tectonic context. in this perspective, an active and capable fault should not be simply defined as a plane separating two rock blocks with differential motion. merely considering the dislocation or differential motion is too simplistic and inadequate because it overlooks the underlying engine that generated it. for instance, a normal fault can displace two blocks with a dip-slip motion, but the same motion can also result from a rotational landslide, a sinkhole, or differential sediment compaction. although both a tectonic active fault and a landslide may cause vertical displacement of rock blocks, the key difference lies in their distinct origins, even if their manifestations may appear similar. the example shown in the sulmona basin testifies to this. this is the reason why, in this view, a “capable” fault does not exist by itself as it cannot be separated from the cause that generated it, that is, tectonics, which has its own rules and processes. the exclusion of causes other than tectonics in the motion of shear planes often results from geomorphologic analysis. however, neotectonics defines the relationship of a shear zone with an active fault system and its role within the local structural setting consistent with the current tectonic regime. within this light, especially in domains characterized by slow tectonic deformation rates, paleoseismology should be considered as a conclusion and completion of neotectonics. 3) similar arguments may be outlined for those geomorphic features that bosi considered “purely circumstantial and may result (and often results) insignificant as for the perspectives of neotectonics” as the bedrock fault scarps. indeed, apart from the choice of sites that may be suitable for specific analyses to date the exposure of a fault plane, it is the recent activity of the fault itself that should be based on detailed geologic investigations preceding site analyses. the reason for such a rigorous approach is clear since the bosi’s words of 1992, dealing with the perspectives of neotectonics, considering the necessity to drastically refute evaluations and deductions unsupported by data. this priority seemed necessary at that time, when the perspective was «to promote greater attention for neotectonics in planning major engineering works» and to give inputs concerning «active tectonics (mainly faults) which may affect the safety of the works». considering the key role these inputs have progressively gained in the past decades, the significance of this warning is greater today than at the time neotectonics needed promotion. in conclusion, neotectonics is a procedure that provides a 4d view of tectonically active regions, or of a fault, or fault segment, as it allows the reconstruction of the influence that the evolution of tectonic activity has left and still leaves on the landscape. this comprehensive understanding provides the most solid foundation for seismotectonic analysis and the assessment of hazards associated with earthquakes. acknowledgements we want to thank dr. james mccalpin and an anonymous reviewer for their constructive revisions. especially the anonymous reviewer, understanding our intention to investigate conceptual issues, that are fundamental grounds of earthquake studies, gave us comprehensive and significant comments on critical issues that we do believe allowed us to strongly improve our manuscript. we are also grateful to massimiliano stucchi: he gave us interesting and necessary information on the italian “progetto finalizzato geodinamica”, together with some of the products resulting from the project activity. references ambrosetti p., bosi c., carraro f., ciaranfi n., panizza m., papani g., vezzani l., zanferrari a. (1987) neotectonic map of italy. consiglio nazionale delle ricerche, progetto finalizzato geodinamica, quaderni de la ricerca scientifica, 114(4). barberi f. (2020) il ruolo di paolo scandone nel progetto finalizzato geodinamica del cnr. workshop “l’eredità di paolo scandone, geologo”, roma, 29 marzo 2019. atti dei convegni lincei, 335, 203204. barchi m., galadini f., lavecchia g., messina p., michetti a.m., peruzza l., pizzi a., tondi e., vittori e. (2000) sintesi delle conoscenze sulle faglie attive in italia centrale. consiglio nazionale delle ricerche gruppo nazionale per la difesa dai terremoti, pp. 62. publisher esagrafica srl. bigi g., cosentino d., parotto m., sartori r., scandone p. (1990) structural model of italy and gravity map. consiglio nazionale delle ricerche progetto finalizzato geodinamica. quaderni de la ricerca scientifica, 114(3). bonilla m.g. (1967) historic surface faulting in continental united states and adjacent parts of mexico. 217 neotectonics for investigating active faults u.s.g.s. report tid-24124, pp. 32. bordoni p., gori s., akinci a., visini f., sgobba s., pacor f., cara f., pampanin s., milana g., doglioni c. (2022) a site-specific earthquake ground response analysis using a fault-based approach and nonlinear modeling: the case pente site (sulmona, italy). engineering geology, 314, 106970. doi: 10.1016/j.enggeo.2022.106970 bosi c. (1992) relazione introduttiva alle giornate di studio sul tema: “la neotettonica in italia a dieci anni dalla fine del progetto finalizzato geodinamica”. il quaternario (italian journal of quaternary science), 5(2), 281-288. bosi c., galadini f., messina p. (1993) neotectonic significance of bedrock fault scarps: case studies from the lazio-abruzzi apennines (central italy). zeitschrift für geomorphologie n.f. suppl.-bd. 94, 187-206. camassi r. (2004) catalogues of historical earthquakes in italy. annals of geophysics, 47 (2/3), 645-657. caputo r., helly b. (2008) the use of distinct disciplines to investigate past earthquakes. tectonophysics, 453, 7-19. ceccaroni e., ameri g., gomez capera a.a., galadini f. (2009) the 2nd century ad earthquake in central italy: archaeoseismological data and seismotectonic implications. natural hazards, 50, 335-359. cello g., mazzoli s., tondi e., turco e. (1997) active tectonics in the central apennines and possible implications for seismic hazard analysis in peninsular italy. tectonophisics, 272, 43-68. cheloni d., de novellis v., albano m., antonioli a., anzidei m., atzori s., avallone a., bignami c., bonano m., calcaterra s., castaldo r., casu f., cecere g., de luca c., devoti r., di bucci d., esposito a., galvani a., gambino p., giuliani r., lanari r., manunta m., manzo m., mattone m., montuori a., pepe a., pepe s., pezzo g., pietrantonio g., polcari m., riguzzi f., salvi s., sepe v., serpelloni e., solaro g, stramondo s., tizzani p., tolomei c., trasatti e., valerio e., zinno i., doglioni c. (2017) geodetic model of the 2016 central italy earthquake sequence inferred from insar and gps data. geophysical research letters, 44, 6778-6787. doi: 10.1002/2017gl073580 cheloni d., falcucci e., gori s. (2019) half-graben rupture geometry of the 30 october 2016 mw 6.6 mt. vettore-mt. bove earthquake, central italy. journal of geophysical research: solid earth, 124. doi: 10.1029/2018jb015851 chiaraluce l., di stefano r., tinti e., scognamiglio l., michele m., casarotti e., cattaneo m., de gori p., chiarabba c., monachesi g., lombardi a., valoroso l., latorre d., marzorati s. (2017) the 2016 central italy seismic sequence: a first look at the mainshocks, aftershocks and source models. seismological research letters, 88(3), 757-771. doi: 10.1785/0220160221 cnr-pfg (1980a) proposta di riclassificazione sismica del territorio nazionale. pubblication n. 361 of progetto finalizzato geodinamica, esa editrice, roma, pp. 83. cnr-pfg (1980b) contributi alla realizzazione della carta neotettonica d’italia, parti i, ii, iii. publication n. 356 of progetto finalizzato geodinamica, officine grafiche napoletane francesco giannini e figli, napoli, pp. 1458. cnr-pfg (1982) contributi conclusivi per la realizzazione della carta neotettonica d’italia, parti i, ii. publications ns. 506 and 513 of progetto finalizzato geodinamica, officine grafiche napoletane francesco giannini e figli, napoli, pp. 432. cowie p.a., gupta s., dawers n.h. (2000) implications of fault array evolution for synrift depocentre development: insights from a numerical fault growth model. basin research, 12, 241-261. falcucci e., gori s., galadini f., fubelli g., moro m., saroli m. (2016) active faults in the epicentral and mesoseismal ml 6.0 24, 2016 amatrice earthquake region, central italy. methodological and seismotectonic issues. annals of geophysics, 59(5). doi: 10.4401/ag-7266 falcucci e., gori s., bignami c., pietrantonio g., melini d., moro m., saroli m., galadini f. (2018) the campotosto seismic gap in between the2009 and 2016-2017 seismic sequencesof central italy and the role of inherited lithospheric faults in regional seismotectonic settings. tectonics, 37, 2425-2445. doi: 10.1029/2017tc004844 finch e., gawthorpe r. (2017) growth and interaction of normal faults and fault network evolution in rifts: insights from three-dimensional discrete element modelling. from: childs c., holdsworth r.e., jackson c.a.-l., manzocchi t., walsh j.j., yielding g. (eds), the geometry and growth of normal faults. geological society, london, special publications, 439, 219-248. fubelli g., falcucci e., mei a., dramis f. (2008) evoluzione quaternaria del bacino di leonessa (rieti). il quaternario, 21 (2), 457-468. fubelli g., gori s., falcucci e., galadini f., messina p. (2009) geomorphic signature of recent activity versus geological evidence of inactivity: the cases of the montagna dei fiori montagna di campli relief and the leonessa basin (central apennines, italy). tectonophysics, 476, 252-268. galadini f. (2006) quaternary tectonics and large-scale gravitational deformations with evidence of rockslide displacements in the central apennines (central italy). geomorphology, 82, 201-228. galadini f., galli p. (2003) paleoseismology of silent faults in the central apennines (italy): the mt. vettore and laga mts. faults. annals of geophysics, 46 (5), 815-836. doi: 10.4401/ag‐3457 galadini f., messina p. (2001) plio-quaternary changes of the normal fault architecture in the central apennines (italy). geodinamica acta, 14, 321-344. galadini f., meletti c., vittori e. (2001) major active faults in italy: available surficial data. netherlands journal of geosciences (geologie en mijnbouw), 80, 95-118. galadini f., falcucci e., galli p., giaccio b., gori s., messina p., moro m., saroli m., scardia g., sposato a. (2012) time intervals to assess active and capable faults for engineering practices in italy. engineering. geology, 139-140, 50-65. galadini et al. 218 doi: 10.1016/j.enggeo.2012.03.012 galli p., galadini f., pantosti d. (2008) twenty years of paleoseismology in italy. earth-science reviews, 88 (1-2), 89-117. galli p., messina p., giaccio b., peronace e. quadrio b. (2012) early pleistocene to late holocene activity of the magnola fault (fucino fault system, central italy). bollettino di geofisica teorica ed applicata, 53 (4), 435-458. galli p., giaccio b., peronace e., messina p. (2015) holocene paleoearthquakes and early-late pleistocene slip rate on the sulmona fault (central apennines, italy). bull. seismol. soc. am., 105, 1-13. doi: 10.1785/0120140029 gawthorpe r.l., leeder, m.r. (2000) tectonosedimentary evolution of active extensional basins. basin research, 12, 195-218. gori s., dramis f., galadini f., messina p. (2007) the use of geomorphological markers in the footwall of active faults for kinematic evaluation: examples from the central apennines. bollettino della società geologica italiana, 126, 365-374. gori s., giaccio b., galadini f., falcucci e., messina p., sposato a., dramis f. (2011) active normal faulting along the mt. morrone south-western slopes (central apennines, italy). international journal of earth sciences, 100, 157-171. grandori g., barberi f. (1980) la difesa dai terremoti. senato della repubblica, integrazioni conoscitive al dialogo parlamentare, palazzo giustiniani, 10 dicembre 1980, pp. 94. http://www.nonquestaprevenzione.it/wp-content/uploads/2021/10/la-difesa-dai-terremoti_10.12.1980_ g.grandori-f.barberi_pfg-cnr.pdf iaea (2022) seismic hazards in site evaluation for nuclear installations, specific safety guide no. ssg-9 (rev. 1). https://www.iaea.org/publications/14665/seismic-ha zards-in-site-evaluation-for-nuclear-installations iaea tecdoc 1767 (2015) the contribution of palaeoseismology to seismic hazard assessment in site evaluation for nuclear installations, iaea tecdoc 1767, 2015. https://www-pub.iaea.org/mtcd/publications/pdf/ te-1767_web.pdf. mccalpin j.p. (2009) paleoseismology. isbn 978-0-12-373576-8 machette m.n. (2000) active, capable, and potentially active faults a paleoseismic perspective. journal of geodynamics, 29, 387-392. messina p., galadini f., galli p., sposato a. (2002) quaternary basin evolution and present tectonic regime in the area of the 1997-98 umbria-marche seismic sequence (central italy). geomorphology, 42, 97-116. michetti a.m., serva l. (1990) new data on the seismotectonic potential of the leonessa fault area (rieti, central italy). rendiconti della società geologica italiana, 13, 37-46. michetti a.m., ferreli l., esposito e., porfido s., blumetti a.m., vittori e., serva l., roberts g.p. (2000) ground effects during the september 9, 1998, mw=5.6, lauria earthquake and the seismic potential of the aseismic pollino region in southern italy. seismological research letters, 71, 31-46. mildon z.k., roberts g.p., faure walker j.p., beck j., papanikolaou i., michetti a.m., toda s., iezzi f., campbell l., mccaffrey k.j.w., shanks r., sgambato c., robertson j, meschis m., vittori e. (2022) surface faulting earthquake clustering controlled by fault and shear-zone interactions. nature communications, 13:7126. doi: 10.1038/s41467-022-34821-5 muir wood r., mallard d.j. (1992) when a fault is ‘extinct’? journal of the geological society london, 149, 251-254. palumbo l., benedetti l., bourlès d., cinque a., finkel r. (2004) slip history of the magnola fault (apennines, central italy) from 36cl surface exposure dating: evidence for strong earthquakes over the holocene. earth and planetary science letters, 225(1-2), 163-176. doi: 10.1016/j.epsl.2004.06.012 papanikolaou i.d., roberts g.p., michetti a.m. (2005) fault scarps and deformation rates in lazioabruzzo, central italy: comparison between geological fault slip-rate and gps data. tectonophysics, 408, 147-176. doi: 10.1016/j.tecto.2005.05.043 piccardi l., gaudamer y., tapponnier p., boccaletti m. (1999) active oblique extension in the central apennines (italy): evidence from the fucino region. geophysical journal international, 139, 499-530. doi: 10.1046/j.1365-246x.1999.00955.x roberts g.p., michetti a.m. (2004) spatial and temporal variations in growth rates along active normal fault systems: an example from the lazio-abruzzo apennines, central italy. journal of structural geology, 26, 339-376. doi: 10.1016/s0191-8141(03)00103-2 slemmons d.b., mckinney r. (1977) definition of “active fault”. miscellaneous paper s-77-8, u.s. army engineer waterways experiment station. soils and pavements laboratory, vicksburg, miss., pp. 23. technical commission for seismic microzonation (commissione tecnica per la microzonazione sismica) (2015) linee guida per la gestione del territorio in aree interessate da faglie attive e capaci (fac), versione 1.0 conferenza delle regioni e delle province autonome dipartimento della protezione civile, roma, 2015. tesson j., pace b., benedetti l., visini f., delli rocioli m., arnold m., aumaître g., bourlès d.l., keddadouche k. (2016) seismic slip history of the pizzalto fault (central apennines, italy) using in situproduced 36cl cosmic ray exposure dating and rare earth element concentrations. journal of geophysical research solid earth, 121, 1983-2003. doi: 10.1002/2015jb012565 tinti e., scognamiglio a., michelini a., cocco m. (2016) slip heterogeneity and directivity of the ml 6.0, 2016, amatrice earthquake estimated with rapid finite‐fault inversion. geophysical research letters, 43, 10745-10752. doi: 10.1002/2016gl071263 walsh j.j., watterson j. (1991) geometric and kinematic coherence and scale effect in normal fault 219 neotectonics for investigating active faults systems. in: roberts a.m., yielding g., freeman b. (eds.), the geometry of normal faults. geological society, london, special publication 56, 193-203. wu z., hu m. (2019) neotectonics, active tectonics and earthquake geology: terminology, applications and advances. journal of geodynamics, 127, 1-15. galadini et al. 220 ms. received: february 28, 2023 revised: june 1, 2023 accepted: june 12, 2023 available online: june 29, 2023 sess 2_16022011_tpr3.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 loess in northern italy. new insights on dating, environment, and archaeology mauro cremaschi1, helena rodnight2, andrea zerboni1 & christoph spötl2 1dipartimento di scienze della terra “a. desio”, università degli studi di milano 2institut für geologie und paläontologie, leopold-franzens-universität, innsbruck corresponding author: m. cremaschi <mauro.cremaschi@unimi.it> abstract: cremaschi m. et al., loess in northern italy. new insights on dating, environment, and archaeology. (it issn 0349-3356, 2011) age, sedimentation, soil forming processes, and geoarchaeological implication of the loess in northern italy are discussed on the basis of new osl dating obtained at several key-sequences in the apennine margin of the po plain and on the base of recent literature. the comparison of field data, soil properties, and luminescence ages offers a new perspective in studying the loess of the po plain during the mis 4 to mis 2. riassunto: cremaschi m. et al., loess in italia settentrionale. nuove informazioni sull’età, l’ambiente e l’archeologia. (it issn 0349-3356, 2011) in questo contributo si discutono l’età, i processi sedimentari, di alterazione e le implicazioni geoarcheologiche del loess in italia settentrionale, principalmente sulla base di nuove datazioni osl su alcune sequenze chiave posizionate lungo il margine appenninico della pianura del po e di dati editi. dal confronto tra evidenze di terreno, proprietà dei suoli e datazioni radiometriche emerge una nuova prospettiva di studio per i loess del bacino padano tra il mis 4 e il mis 2. key words: loess, northern italy, osl dating, glacial phase, mousterian culture. parole chiave: loess, italia settentrionale, datazioni osl, fase glaciale, cultura mousteriana.  loess deposits in northern italy are widespread, as in most of the circum-mediterranean regions; they are typical of the glacial pleistocene ages (coudé-gaussen, 1990 cremaschi, 1990) and are related to poorly vegetated soil surfaces and dry climate (cremaschi, 1990). in northern italy loess occurs as thin sheets at the top of polygenetic paleosols, with the exception of few stratigraphic sequences (busacca & cremaschi, 1998; rellini et al., 2009). furthermore, loess deposits are systematically associated with middle palaeolithic archaeological evidence, indicating that the loess belt surrounding the po plain was densely occupied at that time, representing an ecosystem suitable for human life. recently, an effort has been made to explore different sources for radiometric dating (cremaschi et al., 1987, 1990; ferraro et al., 2004; martini et al., 2001), which appears essential to face the wide range of questions involved in loess research (sedimentation, weathering, climate change, human behaviour). radiocarbon dating (fig. 1) was applied on chernozem-type horizons buried in loess (val sorda and gajum) and in the anthropogenic fill of caves with a windblown silt component (riparo tagliente and grotta di fumane). moreover, tl ages were obtained on fire -damaged flint artefacts buried into loess sequences (ghiardo and bagaggera sites). all the available ages indicate that the loess sedimentation in northern italy begun during the mis 4 and continued until the late mis 2. recent research in the val sorda sequence (fig. 2) proved the suitability of loess for osl and irsl dating and provided results consistent with other chronometric indicators (ferraro, 2009).  this paper presents some recent osl dates performed on three soil profiles (fig. 2) developed on loess and placed along the pede-apennine, at ghiardo cave and cavriago (re) and at borgetto (pr). sampling sites are c. 40 km apart, although they belong to the same geomorphological position, represented by pleistocene terraces. all profiles show the same sedimentological, pedological and geoarchaeological characteristics: a shallow layer of loess, up to 1 m thick which lies upon fluvial clay. in the loess a sol lessive a pseudogley (haplic udalf) is developed, displaying the horizons sequum: ap, e, 2bt, 2bc. the underlying fluvial clay (3bw, 3ck horizons) has outstanding vertic proprieties and a mukkara-type microrelief. mousterian artifacts (of levallois technique) were found at the investigated sites, mostly buried in the 3 bw and 2bc horizons; the latter represents the buried topographic surface and the lithological discontinuity where later pedological processes precipitated fe and mn hydroxides as nodules and concretions. eight preliminary osl dates were obtained, ranging from 47000 to 18000 years and covering 95 97 96 fig. 1, published radiocarbon, tl, and osl dating results from several loess sequences located in northern italy (references in the text). datazioni al radiocarbonio, tl e osl note in letteratura e ottenute in alcune sequenze di loess distribuite in italia settentrionale (referenze bibliografiche riportate nel testo).  fig. 2, (a) stratigraphic section of val sorda site, indicating radiocarbon and luminescence dating results (modified, ferraro, 2009). (b) stratigraphic section at cavriago, indicating the sampling points for osl analyses. (a) la sezione stratigrafica esposta presso la val sorda; i risultati di datazioni al radiocarbonio, osl e irsl sono indicati (modificata da ferraro, 2009). (b) la sezione stratigrafica esposta presso cavriago, con indicati i punti di campionamento per le datazioni osl. m. cremaschi et al. 97 ms. received: testo ricevuto il the whole chronologic interval between mis 4 and mis 2. these results have several consequences: i) they confirm an upper pleistocene age for the loess sheets covering the pede-apennine terraces of the po valley and allowing a correlation with the loess spread at the southern margin of the alps (isolated terraces in the northern po plain, pedealpine terraces, sequences of the garda moraine system, loess in the lessini caves); ii) each profile shows a regular, progressive decrease in loess age toward its surface. this is indicative of a persistent accumulation of dust (decanting from the atmosphere). evidence of syndepositional loess weathering – the development of a slow-rate aggrading cumulic soil – was detected in thin sections by microcharcoals and bioturbation and indicates a steppe environment affected by recurrent fire episodes. the syndepositional pedological features are obscured and partly erased by subsequent holocene soil forming processes (clay illuviation, shrinking and swelling, hydromorphism; cremaschi, 1987, 2008). iii) the chronological difference between the burned flint tools (around 70000-60000 years) and on loess sediments (47000-18000 years) may indicate that mousterian hunters settled the margin of the apennine at the beginning of the mis 4 in suitable environmental conditions, and later left the region, when a severe dry climate prevailed, leading to a stronger loess sedimentation . references busacca a. & cremaschi m. (1998) the role of time versus climate in the formation of deep soils of the apennine fringe of the po valley, italy. quaternary international, 51-52, 95-108. coudé-gaussen g. (1990) the loess and loess-like deposits along the sides of the western mediterranean sea: genetic and palaeoclimatic significance. quaternary international, 5, 1-8. cremaschi m. (1987) loess deposits of the plain of the po and of the adjoining adriatic basin (northern italy). in: pecsi m. & french h.m. (eds.), loess and periglacial phenomena. akademiai kiado, budapest, 125-140. cremaschi m. (1990) the loess in northern and central italy: a loess basin between the alps and the mediterranean sea. centro di studio per la stratigrafia e petrografia delle alpi centrale, milano. cremaschi m. (2008) climate and humans in soil genesis since the late pleistocene. micromorphological aspects of the haplic luvisols, sols lessivées a pseudogley, aqualfs, in the ghiardo area (northern italy). geophysical research abstracts, 10, egu2008a-06279. cremaschi m., alessio m., allegri l., azzi c., calderoni g., cortesi c., petrone v. & spezzi bottiani c. (1987) una data radiocarbonica del palaeosuolo su loess incluso nella successione stratigrafica della val sorda (sistema morenico del garda). rendiconti della società geologica italiana, 10, 29-32. cremaschi m., fedoroff n., guerreschi a., huxtable j., colombi n., castelletti l. & maspero a. (1990) sedimentary and pedological processes in the upper pleistocene loess of northern italy. the bagaggera sequence. quaternary international, 5, 23-38. ferraro f. (2009) age, sedimentation, and soil formation in the val sorda loess sequence, northern italy. quaternary international, 204, 54-64. ferraro f., terhorst b., ottner f. & cremaschi m. (2004) val sorda: an upper pleistocene loess– palaeosol sequence in northeastern italy. revista mexicana de ciencias geologicas, 24, 30-47. martini m., sibilia e., croci s. & cremaschi m. (2001) thermoluminescence (tl) dating of burnt flints: problems, perspectives and some examples of application. journal of cultural heritage, 2, 179-190. rellini i., trombino l., firpo m. & rossi p.m. (2009) extending westward the loess basin between the alps and the mediterranean region: micromorphological and mineralogical evidences from the northern scope of the ligurian alps, northern italy. geografia fisica e dinamica quaternaria, 32, 103-116. january 20, 2011 20 gennaio 2011 loess in northern italy. new insights on dating ... imp.sagnotti contributi del paleomagnetismo alla stratigrafia del pleistocene medio-superiore (brunhes chron) leonardo sagnotti istituto nazionale di geofisica e vulcanologia roma e-mail <sagnotti@ingv.it> abstract: l. sagnotti, the contribute of paleomagnetism to the stratigraphy of the middlelate pleistocene (brunhes chron). this manuscript presents an updated summary on the contribute brought by paleomagnetism to the definition of a high-resolution magnetic stratigraphy for the middle-late pleistocene. the middle-late pleistocene spans a time intervals during which the earth magnetic field held predominantly a stable normal polarity and includes the whole normal polarity brunhes chron. in absence of full reversals of the geomagnetic field, magnetic stratigraphy is based upon (a) the record of geomagnetic paleosecular variations (psv), as documented in archaeological or volcanic material and in lacustrine and marine sedimentary sequences for the last few ka,(b) the variation of geomagnetic paleointensity and (c) the occurrence of geomagnetic excursions . with regards to europe, archeomagnetic psv curves were reconstructed back to 8 ka (i.e., ca. 6000 bc), whereas continuous psv records based on paleomagnetism of sediments extend back to the last 10-12 ka. the variation in intensity of the earth magnetic field has been reconstructed in the detail at a global scale for the last 800 ka. relative paleointensity curves reconstructed in sedimentary sequences provide original correlation and dating tools and are particularly valuable to establish high-resolution age models in sequences that may lack other valuable stratigraphic proxies, such as those deposited in the carbonate-corrosive waters of peri-antarctic margins. finally, the recognition and the dating of geomagnetic excursions, defined as sharp, short-lived and wide geomagnetic variations, during which the earth magnetic field has departed from its usual near-axial configuration but did not give rise to complete reversals, is providing the basis for the establishment of a geomagnetic instability time scale (gits) that extends back to the last 2.2 ma. parole chiave: stratigrafia paleomagnetica, pleistocene medio-superiore. keywords: paleomagnetic stratigraphy, middle-late pleistocene. il quaternario italian journal of quaternary sciences 21(1a), 2008 69-74 introduzione sin dagli anni '60, quando sono state messe a punto le prime versioni della scala temporale delle polarità magnetiche, la classica applicazione delle ricerche di paleomagnetismo negli studi di stratigrafia è stata quella dell'uso delle inversioni di polarità del campo magnetico terrestre (cmt) identificate in successioni stratigrafiche quale elemento geofisico di correlazione a scala globale di sequenze laviche e sedimentarie, terrestri e marine. negli ultimi decenni si sono progressivamente raffinate la conoscenze, e l'inquadramento cronologico, sulle variazioni del cmt a diversa scala temporale. queste conoscenze hanno portato allo sviluppo di potenzialità originali per l'uso del paleomagnetismo a fini stratigrafici anche durante le epoche (chron) a polarità magnetica costante. i risultati ottenuti hanno significativamente ampliato, in particolar modo, le possibili applicazioni stratigrafiche del paleomagnetismo nello studio di successioni rocciose formatesi durante l'attuale epoca di polarità magnetica normale (brunhes chron), che copre gli ultimi 780 ka circa (si rimanda a singer et al., 2005 per una dettagliata discussione della cronologia relativa alla dinamica del cmt a ridosso dell'ultima inversione di polarità del campo). nello specifico, le conoscenze progressivamente acquisite su (a) i cambiamenti locali di direzione del cmt legati alla paleovariazione secolare, sulle variazioni di intensità del cmt (b) e sulla presenza di escursioni geomagnetiche (c) forniscono originali elementi stratigrafici che possono permettere di correlare e datare ad alta risoluzione sequenze stratigrafiche dell'olocene e del pleistocene medio-superiore. nel seguito, verranno sinteticamente esposti gli elementi fondamentali che caratterizzano queste variazioni del cmt ed alcuni esempi di applicazione a fini stratigrafici delle relative registrazioni paleomagnetiche. la paleovariazione secolare l'esecuzione di sistematiche osservazioni dirette sulla direzione del cmt è limitata, nei casi più favorevoli, agli ultimi 4 secoli. queste osservazioni hanno comunque permesso di riconoscere l'esistenza di una variazione secolare del cmt e di definire delle curve locali di variazione della declinazione ed inclinazione del campo a partire dal xvii secolo (per le principali capitali europee). per una breve rassegna della storia delle osservazioni e misure dirette del cmt si rimanda al recente articolo di jonkers (2007) e, per la storia delle misure geomagnetiche in italia in particolare, alle sintesi di cafarella et al., 1992 e lanza et al., 2005a. lo studio del paleomagnetismo delle sequenze sedimentarie e laviche da l'opportunità di estendere nel tempo geologico le misurazioni dirette sulle variazioni del cmt e al contempo fornisce un originale metodo di datazione delle successioni stratigrafiche (e.g. verosub, 1988). in particolare, i dati paleomagnetici relativi a successioni vulcaniche o a successioni sedimentarie ad alto tasso di deposizione (prevalentemente lacustri) ha 70 l. sagnotti portato alla definizione di curve di riferimento per la ricostruzione della paleovariazione secolare (psv master curves) del cmt, valide a scala regionale su aree che si estendono per varie decine di gradi in latitudine e longitudine (e.g. hagstrum & champion, 2002; st-onge et al., 2003; turner & thompson, 1981; 1982). al momento, le psv master curves disponibili per la regione europea si estendono a coprire gli ultimi 10-12 kyr (e.g. snowball et al., 2007) (fig. 1). i dati di psv da successioni sedimentarie hanno il vantaggio di fornire una registrazione “continua” delle variazioni del cmt, ma soffrono al contempo dell'effetto di “filtraggio” del segnale geomagnetico primario, legato alla diluizione temporale dei processi di acquisizione di una magnetizzazione rimanente da parte dei sedimenti durante la deposizione, la compattazione e la diagenesi. questo effetto a sua volta si traduce in una profondità variabile del livello stratigrafico in cui la magnetizzazione naturale risulta effettivamente bloccata e può essere mantenuta per tempi geologici (e.g. bleil & von dobeneck,1999; hyodo, 1984; roberts & winklhofer, 2004; sagnotti et al., 2005; spassov et al., 2003; verosub, 1977). per quanto riguarda le possibili applicazioni a fini stratigrafici nell'area italiana, i dati paleomagnetici sulla paleovariazione secolare del cmt sono stati recentemente applicati quali originale strumento di datazione ad alta risoluzione in sequenze sedimentarie oloceniche sia lacustri (e.g. brandt et al., 1999) che marine (e.g.; iorio et al., 2004; rolph et al., 2004; vigliotti, 2006). d'altra parte, i dati paleomagnetici da sequenze vulcaniche hanno il vantaggio di fornire delle letture “istantanee” ad alta definizione della direzione del cmt all'epoca dell'eruzione, ma soffrono al contempo del limite di essere discontinue a scala temporale. per cui l'uso di tali dati a fini di stratigrafici è vincolato ad una correlazione (sovente non univoca) dei dati paleomagnetici da distinti corpi vulcanici alle psv master curves. le applicazioni dello studio a fini stratigrafici della paleovariazione secolare nei prodotti vulcanici dell'area mediterranea sono numerose e riguardano tutti i principali vulcani attivi italiani (e.g. hoye, 1981; incoronato et al., 2002; lanza & zanella, 2003; lanza et al., 2005a; principe et al., 2004; rolph et al., 1987; speranza et al., 2004; 2006; tanguy et al., 2003). negli ultimi anni si è sviluppato un vivace dibattito specificatamente focalizzato sui limiti di risoluzione cronologica che possono essere raggiunti con metodi paleomagnetici (si veda arrighi et al., 2005; lanza & zanella, 2006; lanza et al., 2005b; principe et al., 2006; speranza et al., 2005; 2006; tanguy et al., 2005). e' opinione dello scrivente che le incertezze insite nel metodo implicano che le datazioni originali che possono essere ottenute attraverso lo studio paleomagnetico di corpi vulcanici eruttati nel corso degli ultimi migliaia di anni sono solitamente definite con un'approssimazione alla scala secolare, che può restringersi ad alcuni decenni solo nei casi più favorevoli per i periodi caratterizzati da un elevato rateo di variazione direzionale del cmt. nel corso degli ultimi decenni numerosi dati sono stati pubblicati sulla paleovariazione del cmt registrata in materiale archeologico. la mole di dati raccolta ha consentito di mettere a punto varie curve archeomagnetiche di riferimento che si estendono fino a 8 ka (6000 a.c.) circa per le variazioni di direzione ed inclinazione del cmt nell'area europea, con i dati più estesi, continui ed affidabili relativi alla regione francese, alle isole britanniche ed alla bulgaria (e.g. bucur et al., 1994; gallet et al., 2002; kovacheva et al., 1998; zanariri et al., 2007). tali curve vengono poi utilizzate quale riferimento per la datazione di materiale archeologico (principalmente fornaci e terrecotte; si veda jordanova et al., 2004 a titolo di esempio). le variazioni di paleointensità parallelamente alle ricerche sulle variazioni direzionali del cmt si sono progressivamente sviluppate anche le ricerche sulle variazioni di paleointensità del campo. tali ricerche si articolano prevalentemente su due “filoni”: (1) studi volti alla ricostruzione della paleointensità assoluta del campo mediante lo studio paleomagnetico di materiale archeologico (per le ultime migliaia di anni; e.g. aitken et al., 1988; genevey & gallet, 2002), di materiale vulcanico (e.g. hill & shaw, 1999), e di inclusioni ferromagnetiche in singoli cristalli (che arrivano a coprire praticamente l'intera storia della terra; si veda la recente rassegna di tarduno et al., 2007), e (2) studi sulla variazione di paleointensità relatifig. 1 la curva di paleovariazione secolare recentemente pubblicata da snowball et al. (2007) per l'olocene della regione scandinava (fennostack). i dati di declinazione ed inclinazione paleomagnetica sono stati filtrati con una finestra mobile di 150 anni. le curve sottili indicano i limiti superiore ed inferiore di 95% di confidenza associati con le medie mobili. the holocene paleomagnetic secular variation master curve for fennoscandia (fennostack) recently published by snowball et al. (2007). the paleomagnetic declination and inclination data were smoothed with a 150-year running window. the thin lines indicate theupper and lower 95% confidence limits associated with each average value. va registrata in sequenze sedimentarie (e.g. tauxe, 1993; valet, 2003; brachfeld, 2007). quest'ultimo filone è senz'altro quello più utile al fine di datare e correlare successioni stratigrafiche. lo studio di decine di curve di variazione della paleointensità relativa (rpi) del cmt in carote sedimentarie prelevate nei diversi oceani ha portato alla messa a punto di curve sintetiche globali di riferimento che coprono attualmente gli ultimi 800 ka (sint-200 e sint-800 di guyodo & valet, 1996; 1999) e che forniscono una documentazione continua della variazione rpi del campo (fig. 2a). curve regionali a più alta risoluzione sono state successivamente ricostruite per intervalli temporali di più breve durata (quali la napis-75 per l'atlantico settentrionale, laj et al., 2000 e sapis per l'atlantico meridionale; stoner et al., 2002), poi riunite in uno curva sintetica globale (glopis-75; laj et al., 2004) che si estende per gli ultimi 75 ka. la ricostruzione di curve rpi e la correlazione alle curve sintetiche globali di riferimento permettono di definire dei modelli di età originali ad alta risoluzione in sequenze sedimentarie che sono difficilmente databili per altra via, come ad esempio le successioni dai bacini marginali periantartici, ove le acque sono corrosive per i microfossili a gusci carbonatico (e.g. brachfeld et al., 2003; macrì et al. 2005; 2006; sagnotti et al., 2001). le escursioni del cmt le escursioni geomagnetiche sono definite come quei casi in cui il cmt si è notevolmente discostato dalla usuale configurazione di campo prevalentemente dipolare, pressoché allineato all'asse di rotazione. ossia, le escursioni sono state definite come eventi di instabilità geomagnetica in cui il polo geomagnetico virtuale ha avuto una colatitudine > 45°. si tratta di eventi di relativamente breve durata (generalmente < 2 ka) che si concludono senza che si stabilizzi una effettiva inversione di polarità. per l'effettiva distinzione tra escursioni ed inversioni del cmt si rimanda al fondamentale articolo di gubbins (1999). la definizione del numero e la datazione delle escursioni geomagnetiche effettivamente occorse durante il brunhes sono tuttora oggetto di revisione (e.g. channell, 2006; lund et al., 2006; macrì et al., 2005; roberts & winklhofer, 2004). un primo tentativo di sintesi è stato proposto nella redazione di una prima scala temporale di 71contributi del paleomagnetismo alla stratigrafia ... instabilità geomagnetica (gits) pubblicata da singer et al. (2002),con ben 14 possibili escursioni nel corso del chron brunhes. nella versione più recente della gits (singer, 2007) il numero di escursioni geomagnetiche nel chron brunhes è ridotto a 12, e la loro occorrenza viene posta in relazione alle variazioni di intensità del cmt per gli ultimi 0.8 ma (fig. 2b). la gits di singer (2007) è estesa agli ultimi 2.2 ma ed include anche le escursioni occorse nella parte alta del chron matuyama. la datazione delle escursioni è solitamente basata su datazioni radiometriche in sequenze vulcaniche o sull'interpolazione e sulla calibrazione astronomica di marker isotopici nelle successioni sedimentarie. in ogni caso, l'identificazione di una escursione geomagnetica in una successione rocciosa ha considerevoli potenzialità ai fini di correlazione e di datazione stratigrafica, in quanto la brevità dell'evento può consentire una datazione dei livelli interessati ad altissima risoluzione. fig. 2 a) la curva sintetica globale di variazione di paleointensità relativa per gli ultimi 800000 anni (sint-800 di goyodo & valet, 1999), b) la “geomagnetic instability time scale” di singer (2007) per il chron di polarità magnetica normale brunhes. in grigio vengono indicate le escursioni che non sono ancora ritenute precisamente datate o che sono meno definite paleomagneticamente. in bianco sono indicate le escursioni datate con maggior precisione e ben documentate in diverse successioni stratigrafiche. a) the global relative paleointensity stack curve for the last 800 ka (sint-800 of guyodo and valet, 1999), b) the geomagnetic instability time scale of singer (2007) for the brunhes chron. grey intervals indicate geomagnetic excursions which are still poorly documented or not yet precisely dated. white intervals indicate the geomagnetic excursions which have been reliably documented in various stratigraphic sequences and are dated with greater accuracy. bibliografia aitken m., a. allsop g. bussell, and m. winter, 1988. determination of the intensity of the earth's magnetic field during archaeological times: reliabil ity of the thell ier technique, rev. geophys., 26, 3 -12. arrighi s., j.-c. tanguy v. courtillot and m. legoff 2005. reply to comment by f. speranza et al. on ''recent eruptive history of stromboli (aeolian islands, italy) determined from high-accuracy archeomagnetic dating'', geophys. res. lett., 32(23), l23305, doi:10.1029/2005gl023768. bleil u. and v. dobeneck t., 1999. geomagnetic events and relative paleointensity records clues to highresolution paleomagnetic chronostratigraphies of late quaternary marine sediments? in: use of proxies in paleoceanography: examples from the south atlantic (fischer, g. and wefer, g., eds.), pp. 635-654. springer-verlag, berlin heidelberg. brachfeld s.a., domack e.w., kissel c., laj c., leventer a., ishman s.e., gilbert r., camerlenghi a., eglinton l.b., 2003. holocene history of the larsen ice shelf constrained by geomagnetic paleointensity dating. geology, 31: 749-752. brachfeld s.a., 2007. paleointensity, relative, in sediments in: encyclopedia of geomagnetism and paleomagnetism; (editors david gubbins and emilio herrero-bervera), springer, 1054 pp., p. 758-765. brandt u., nowakzyk n.r., ramrath a., brauer a., mingram j.,wulf, s. and negendank j.f.w., 1999. paleomagnetism of holocene and late pleistocene sediments from lago di mezzano and lago grande di monticchio (italy): initial results, quat. sci. rev., 18, 961-976. bucur i., 1994. the direction of the terrestrial magnetic field in france, during the last 21 centuries: recent progress, phys. earth planet. inter., 87, 95-109. cafarella l., a. de sanctis and a. meloni 1992. secular variation in italy from historical geomagnetic field measurements, phys. earth planet. int., 63, 206-221. channell j.e.t., 2006. late brunhes polarity excursions (mono lake, laschamp, iceland basin and pringle falls) recorded at odp site 919 (irminger basin), earth planet. sci. lett., 244, 378-393. gallet y., a. genevey and m. le goff, 2002. three millennia of directional variation of the earth's magnetic field in western europe as revealed by archaeological artefacts, phys. earth planet. inter., 131, 8189. genevey a. and y. gallet, 2002. intensity of the geomagnetic field in western europe over the past 2000 years: new data from ancient french pottery, j. geophys. res., 107, no. b11, 2285, doi:10.1029/ 2001jb000701. gubbins d., 1999. the distinction between geomagnetic excursions and reversals, geophys. j. int. 137, f1-f3. guyodo y. and valet j.-p., 1996. relative variations in geomagnetic intensity from sedimentary records: the past 200,000 years. earth planet. sci. lett., 143: 23-36. guyodo y. and valet j.-p., 1999. global changes in intensity of the earth's magnetic field during the past 800 kyr. nature (london) 399: 249-252. hagstrum j. t. and d. e. champion, 2002. a holocene paleosecular variation record from 14c-dated volcanic rocks in western north america, j. geophys. res., 107(b1), 2025, doi:10.1029/ 2001jb000524. hill m.j. and j. shaw, 1999. palaeointensity results for historic lavas from mt etna using microwave demagnetization/remagnetization in a modified thellier-type experiment, geophys. j. int. 139 (2), 583-590. hyodo m., 1984. possibility of reconstruction of the past geomagnetic field from homogeneous sediments, journal of geomagnetism and geoelectricity, 36, 45-62 hoye g. s., 1981. archaeomagnetic secular variation record of mount vesuvius, nature, 291, 216218. incoronato a., a. angelino r. romano a. ferrante r. sauna g. vanacore and c. vecchione, 2002. retrieving geomagneticsecular variation from lava flows: evidence from mount arso, etna andvesuvius (southern italy), geophys. j. int., 149, 724-730. iorio m., l. sagnotti a. angelino f. budillon b. d'argenio j. dinarès-turell p. macrì and e. marsella, 2004. high resolution petrophysical and palaeomagnetic study of late holocene shelf sediments, salerno gulf, tyrrhenian sea, the holocene, 14, 417-425. jonkers a.r.t., 2007. history of geomagnetism, in: encyclopedia of geomagnetism and paleomagnetism; (editors david gubbins and emilio herrero-bervera), springer, 1054 pp., p. 355-360. jordanova n., m. kovacheva and m. kostadinova, 2004. archaeomagnetic investigation and dating of neolithic archaeological site (kovachevo) from bulgaria, phys. earth planet. int., 147, 89-102. kovacheva m., n. jordanova and v. karloukovski, 1998. geomagnetic field variations as determined from bulgarian archaeomagnetic data. part ii: the last 8000 years, surv. geophys., 19, 431-460. laj c., c. kissel, a. mazaud j.e.t channell and j. beer, 2000. north atlantic paleointensity stack since 75 ka (napis-75) and the duration of the laschamp event. phil. trans. r. soc. lond. a 358, 1009-1025. laj c., c. kissel j. beer, 2004. high resolution global paleointensity stack since 75 kyr (glopis-75) calibrated to absolute values, timescales of the paleomagnetic field, agu geophysical monograph series, vol. 145, pp. 255-265. lanza r. and e. zanella, 2003. paleomagnetic secular variation at vulcano (aeolian islands) during the last 135 kyr, earth planet. sci. lett., 213, 321-336. lanza r., a. meloni and e. tema, 2005a, historical measurements of the earth's magnetic field compared with remanence directions from lava flows in italy over the last four centuries, phys. earth planet. inter., 148, 97107. lanza r., a. meloni and e. tema, 2005b. reply to comment on ''historical measurements of the earth's magnetic field compared with remanence directions from lava flows in italy over the last four 72 l. sagnotti centuries'' by tanguy j.-c., principe c., arrighi s., phys. earth planet. inter., 152, 121124. lanza r., and e. zanella, 2006. comments on ''chronology of vesuvius' activity from a. d. 79 to 1631 based on archeomagnetism of lavas and historical sources'' by c. principe et al., bull. volcanol., 68, 394-396. lund s,. j.s. stoner j.e.t. channell and g. acton, 2006. a summary of brunhes paleomagnetic field variability recorded in ocean drilling program cores, phys. earth planet. int., 156, 194-204. macrì p., l. sagnotti j. dinarès-turell and a. caburlotto, 2005. a composite record of late pleistocene relative geomagnetic paleointensity from the wilkes land basin (antarctica), physics of the earth and planetary interiors, 151, 223-242. macrì p., l. sagnotti and r.g. lucchi, 2006. a stacked record of relative geomagnetic paleointensity for the past 270 kyr from the western continental rise of the antarctic peninsula, earth planet. sci. lett., 252, 162-179. principe c., j.-c. tanguy s. arrighi, a. paiott, m. le goff and u. zoppi, 2004. chronology of vesuvius' activity from ad 79 to 1631 based on archeomagnetism of lavas and historical sources, bull. volcanol., 66, 703-724. principe c., j.-c. tanguy, s. arrighi and m. le goff, 2006. reply to the comment on ''chronology of vesuvius' activity from a. d. 79 to 1631 based on archeomagnetism of lavas and historical sources'' by r. lanza and e. zanella, bull. volcanol., 68, 397398. roberts a.p. and m. winklhofer, 2004. why are geomagnetic excursions not always recorded in sediments? constraints from post-depositional remanent magnetization lock-in modelling, earth planet. sci. lett., 227, 345-359. rolph t.c., j. shaw and j.e. guest 1987. geomagnetic field variations as a dating tool: application to sicilian lavas, j. archaeolog. sci., 14, 215-225. rolph t.c., l. vigliotti and f. oldfield, 2004. mineral magnetism and geomagnetic secular variation of marine and lacustrine sediments from central italy: timing and nature of local and regional holocene environmental change, quat. sci. rev., 23, 1699-1722. sagnotti l., p. macrì, a. camerlenghi and m. rebesco, 2001. environmental magnetism of late pleistocene sediments from the pacific margin of the antarctic peninsula and interhemispheric correlation of climatic events. earth planet. sci. lett., 192: 65-80. sagnotti l., f. budillon, j. dinarès-turell, m. iorio and p. macrì, 2005. evidence for a variable paleomagnetic lock-in depth in the holocene sequence from the salerno gulf (italy): implications for “high-resolution” paleomagnetic dating, geochemistry, geophysics, geosystems, vol. 6, n. 11, q11013, doi:10.1029/2005gc001043. singer b.s., m.k relle, k.a hoffman, a. battle, c. laj, h. guillou and j.c. carracedo, 2002. ar/ar ages from transitionally magnetized lavas on la palma, canary islands, and the geomagnetic instability timescale. j. geophys. res., 107(b11): 2307. doi: 10.1029/2001jb001613. singer b.s., k.a. hoffmann, r.s. coe, l.l. brown, b.r. jicha, m.s. pringle and a. chauvin, 2005. structural and temporal requirements for geomagnetic field reversal deduced from lava flows, nature, 434, 633-636. singer b.s., 2007. polarity transitions: radioisotopic dating, in: encyclopedia of geomagnetism and paleomagnetism; (editors david gubbins and emilio herrero-bervera), springer, 1054 pp., p. 834-839. snowball i., l. zillén, a. ojala, t. saarinen and p. sandgren, 2007. fennostack and fennorpis: varve dated holocene palaeomagnetic secular variation and relative palaeointensity stacks for fennoscandia, earth and planet. sci. lett., 255, 106-116. spassov s., f. heller, m.e. evans, l.p. yue, t. von dobeneck, 2003. a lock-in model for the complex matuyama-brunhes boundary record of the loess/palaeosol sequence at lingtai (central chinese loess plateau), geophys. j. int., 155, 350-366. speranza f., m. pompilio and l. sagnotti, 2004. paleomagnetism of spatter lavas from stromboli volcano (aeolian islands, italy): implications for the age of paroxysmal eruptions, geophysical research lettere 31, doi: 10.1029/ 2003gl018944, 2004. speranza f., l. sagnotti and a. meloni, 2005. comment on “recent eruptive history of stromboli (aeolian islands, italy) determined frm high-accuracy archeomagnetic dating” by s. arrighi et al., geophysical research letters, 32, l23306, doi:10.1029/2005gl022590. speranza f., s. branca, m. coltelli, f. d'ajello caracciolo and l. vigliotti, 2006. how accurate is “paleomagnetic dating” ? new evidence from historical lavas from mount etna, j. geophys. res., 111, b12s33, doi:10.1029/2006jb004496. stoner j.s., c. laj, j:e:t: channell and c. kissel, 2002. south atlantic (sapis) and north atlantic (napis) geomagnetic paleointensity stacks (0-80 ka): implications for inter-hemispheric correlation. quat. sci. rev., 21: 1142-1151. st-onge g., j.s. stoner and c. hillaire-marcel, 2003. holocene paleomagnetic records from the st. lawrence estuary, eastern canada: centennial to millennial-scale geomagnetic modulation of cosmogenic isotopes, earth planet. sci. lett., 209, 113-130. tarduno j.a., r.d. cottrell and a.v. smirnov, 2007. paleointensity: absolute determinations using single plagioclase crystals, in: encyclopedia of geomagnetism and paleomagnetism; (editors david gubbins and emilio herrero-bervera), springer, 1054 pp., p. 749-753. tanguy j.-c., c. principe and s. arrighi, 2005. comment on ''historical measurements of the earth's magnetic field compared with remanence directions from lava flows in italy over the last four centuries'' by r. lanza, a. meloni, and e. tema, phys. earth planet. inter., 152, 116-120. tanguy j-c., m. le goff, c. principe, s. arrighi, v. chillemi, a. paiotti, s. la delfa and g. patanè, 2003. archeomagnetic dating of mediterranean 73contributi del paleomagnetismo alla stratigrafia ... volcanics of the last 2100 years: validity and limits, earth planet. sci. lett., 211, 111-124. tauxe l., 1993. sedimentary records of relative paleointensity of the geomagnetic field: theory and practice, rev. geophys., 31, 319-354. turner g.m. and r. thompson, 1981. lake sediment record of the geomagnetic secular variation in britain during holocene times, geophys. j. r. astr. soc., 65, 703-725. turner g.m. and r. thompson, 1982. detransformation of the british geomagnetic secular variation record for holocene times, geophys. j. r. astr. soc., 70, 789-792. valet j.p., 2003. time variations in geomagnetic intensity. rev. geophys., 41, 1004, doi:10.1029/ 2001rg000104. verosub k.l., 1977. depositional and post-depositional processes in the magnetization of sediments. reviews of geophysics and space physics, 15, 129-143. verosub k.l., 1988. geomagnetic secular variation and the dating of quaternary sediments, geol. soc. of america. spec. paper, 227, 123-138. vigliotti l., 2006. secular variation record of the earth's magnetic field in italy during the holocene: constraints for the construction of a master curve, geophys. j. int., 165, 414-429. zananiri i., c.m. batt, ph. lanos, d.h. tarling and p. linford, 2007. archaeomagnetic secular variation in the uk during the past 4000 years and its application to archaeomagnetic dating, phys. earth planet. int., 160, 97-107. ms. ricevuto il 2 aprile 2008 testo definitivo ricevuto il 17 aprile 2008 ms. received: april 2, 2008 final text received: april 17, 2008 74 l. sagnotti ojs 631 monegato et al def.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 35 (2), 2022, 119-134 the ticino-toce ice conveyor belts during the last glacial maximum. giovanni monegato 1, sarah kamleitner 2, franco gianotti 3, silvana martin 4, cristian scapozza 5, susan ivy-ochs 2 1 institute of geosciences and earth resources, national research council, padova, italy. 2 laboratory of ion beam physics, eth zurich, zurich, switzerland. 3 dipartimento di scienze della terra, università di torino, torino, italy. 4 dipartimento di geoscienze, università di padova, padova, italy. 5 istituto scienze della terra, scuola universitaria professionale della svizzera italiana supsi, mendrisio, switzerland. corresponding author: g. monegato <giovanni.monegato@igg.cnr.it> abstract: the provenance and distribution of erratic boulders of the ticino-toce glacier network yields key information for determining glaciers’ paleoflow and highlights the interaction between two major alpine glacier systems during the last glacial maximum (lgm). boulders in the central and western parts of the verbano, as well as in the smaller orta end moraine systems, originate from the toce catchment. erratics pertaining to the ticino mountain basin characterize the eastern flank of the verbano amphitheatre and the glacial deposits in the ceresio system. the wide distribution of toce lithologies in the verbano end moraine system can, despite its smaller overall size, be ascribed to the hypsometry and valley course of the toce catchment. areas with highest-elevation (>4000 m a.s.l.) and a short flow path (<100 km), favored the early spread of the toce glacier. in the first phase of the lgm, the preceding advance of the toce glacier may have suppressed the larger, possibly inert, ticino glacier towards the east forcing its diffluence into the prealpine area of ceresio, which had no local glaciers and was likely impacted by a western branch of the adda glacier. the dynamics of the ticino-toce glacier network during the lgm highlight the role of the topography and location of the accumulation areas in driving differential development of glaciers originating from high catchments that can force nearby glaciers with greater inertia towards a different path. keywords: european alps, last glacial maximum, palaeoglacier, erratic boulder, provenance. . 1. introduction glacial dispersal trains (shilts, 1982) i.e. trails of deposits and clasts eroded from a bedrock source, transported downglacier and deposited in the stratigraphic record (cummings & russell, 2018) represent an important tool for understanding the flow of glaciers and the delivery of glacigenic sediments, including the distribution of particular types of rocks or minerals in the glacial till (e.g., shilts, 1993; mcclenaghan et al., 2001). empirical tests in tills of boreal ice sheets (e.g., larson & mooers, 2004) highlight the key role that distance from the source areas plays in the downflow distribution of the indicator lithotypes in glacigenic deposits. in glaciated mountains the dispersal train largely follows the major valleys towards the piedmont plains. gravitational processes (e.g., rock fall, slope failures) occurring at the interface of the glacier and the ice-free valley slopes promote debris accumulation and its consequent embedding into the ice (e.g., evans, 2003; goodsells et al., 2005). supraglacial delivery including large (erratic) boulders represents a peculiar characteristic of mountain glaciers. erratic boulders evidence past glacier extents, even where no till can be found. they are key to inferring the pathways and transfluences within the network of valley glaciers that developed in the alps during pleistocene glaciations (e.g. van husen, 2004; kelly et al., 2004; bini et al., 2009). understanding the dynamics of large mountain glaciers during pleistocene glaciations is intriguing because present-day analogs are scarce and located at different latitudes (i.e. alaskan range or patagonian andes) or at different elevations (himalaya). modern glaciers with piedmont lobes are very rare and limited to the alaskan range, kunlun mountains and iceland. consequently, a multidisciplinary approach is needed to reconstruct the functioning of past alpine ice-stream networks. for the european alps, the excellent knowledge on last glacial maximum (lgm) glacier extent has fostered numerous glacier modelling studies and related ela interpretations (becker et al., 2016; jouvet et al., 2017; cohen et al., 2018; seguinot et al., 2018; imhof et al., 2019; višnjević et al., 2020; seguinot & delaney, 2021; del gobbo et al., 2022). modelling results additionally provide information on paleoglacier velocity, sliding, thickness and flow path. even if the simulations show certain discrepancies with the sedimentological and geomorphological data with regard to glacier extent and ice thickness, they raise important questions about ice development during major glaciations and the building of interconnections among the valley glaciers (bini et al., 2009; seguinot et al., 2018). https://doi.org/10.26382/amq.2022.07 120 monegato g. et al. reconstructions based on geomorphological/geological data become more difficult moving from the outer sectors of the chain, where piedmont lobes spread onto the plain, to the axial sector, where the accumulation areas were located. in this inner portion of the cathement the landforms related to the glacial maxima are scarce, while glacigenic sediments are present but hardly useful for paleoglacier reconstruction. a key tool for understanding the flow of paleoglaciers and their possible interconnections through transfluences is the provenance of glacial debris and particularly that of erratic boulders carrying the lithological signature of the source catchment (e.g., coutterand et al., 2009; coutterand, 2010; jouvet et al., 2017; braakhekke et al., 2020). large erratic boulders are more suited than smaller clasts for such a task as they are large enough to barely suffer from the possible bias of reworking, as their datings to the lgm have shown (see section materials and methods). while not every type of rock can produce big boulders, those boulders transported on the ice surface would not suffer from mixing and would generally remain on the side of the glacier that they fell onto. an exception in this assumption is related to large landslides, which may scatter the debris across the whole width of the flowing glacier (e.g., menzies et al., 2017; frasca et al., 2020). boulder roundness can additionally inform about the transport position (supraglacial or subglacial). the potential of using erratic boulders to model glacier flow was shown by several studies (florineth & schlüchter, 1998; jouvet et al., 2017; cohen et al., 2018), yet the coupling with chronology is critical. through field studies and different absolute dating techniques, the chronology of the alpine lgm has been refined over the last decades, allowing to depict the lgm ice margin in several sectors of the mountain range (monegato et al., 2007, 2017; reber et al., 2014; scapozza et al., 2014; gianotti et al., 2015; bernoulli et al., 2018; ivy-ochs et al., 2018; braakhekke et al., 2020; kamleitner et al., 2022a; kamleitner et al., 2022b). the present study shows the reconstruction of the paleo -ice streams of the ticino-toce glacier system (fig. 1), one of the largest paleoglaciers in the central southern fig. 1 extent of the lgm ticino-toce glacier system (modified after bini et al. 2009, braakhekke et al., 2020 (orta lobe), kamleitner et al., 2022a (verbano lobe)). red dots represent erratic boulders included in different studies (bernoulli et al., 2018; braakhekke et al., 2020; kamleitner et al., 2022a). 121 the ticino-toce ice conveyor belts during the last glacial maximum alps, and possibly interconnections with neighboring catchments of rhone, reuss, rhine and adda. the lgm chronology of the ticino-toce glacier system was recently assessed by the means of exposure dating of erratic boulders and geomorphological considerations (braakhekke et al., 2020; kamleitner et al., 2022a). this allowed to reconstruct the shape of the orta and verbano piedmont lobes in detail (fig. 1). evaluating the boulders' source areas may allow to infer the flow lines of the ticino-toce ice streams and test existing glacier models (seguinot et al., 2018), which suggest asynchrony in the development between the ticino and the toce valley glaciers. 2. study area the ticino-toce catchment is about 6700 km2 in size and located in the western alps, south of the main alpine divide. the drainage basin is characterized by an unequal distribution of elevation (fig. 1, fig. 2). the highest peaks are located at the western boundary along monte rosa-fletschhorn line with elevations up to above 4600 m a.s.l. whereas, the northern and especially the eastern sectors have accumulation areas below 3500 m a.s.l. the southern parts of the catchment are characterized by several valley reaches, some filled by lakes. the longitudinal profiles of the valleys illustrate the asymmetry between the toce and ticino catchments, with the former being characterized by high gradients and the latter by longer reaches (fig. 3). the ticino and toce valleys are overdeepened (preusser et al., 2010), with the base of bedrock reported at 600 m b.s.l. at the magadino plain, progressively decreasing to maximum basin depth of 800 m b.s.l. halfway between luino and laveno (cazzini et al., 2020). the overdeepening of these valleys, similarly to other valleys on the southern flanks of the alps, is assumed to have formed during the messinian salinity crisis (bini et al., 1978, finckh, 1978, hantke, 1983). debris flow, fluvial and fluvio-deltaic sediments of messinian age (miocene), as well as marine sediments of zanclean age (pliocene), were indeed observed in the valleys between mendrisio (southern switzerland) and varese (northern italy) (bernoulli et al., 2018). nevertheless, this interpretation is debated and a glacial origin of the upstream sections of southern alpine valleys is currently proposed (winterberg et al., 2020). the lake bottom at the outlet of the ossola valley does not show a fluvial incision and, during the messinian, the toce river was inferred to have flowed into the orta valley (cazzini et al., 2020), fig. 2 geological map of the ticino-toce catchment. data synthesized from swisstopo (2005). tinental crust, including the mantle peridotite series, which was tilted vertically and brought to the surface during alpine orogenesis (rutter et al., 2007). a thick sequence of high-grade metapelitic schists referred to as the “kinzigite” formation, intruded by gabbro and diorite plutons at the mantle-crust boundary. these "kinzigite" schists contain mainly garnet, biotite, plagioclase, quartz, sillimanite and possible muscovite (rutter et al., 2007). early permian granites (named graniti dei laghi, gla) intruded the lam (i.e. plutons of mottarone and montorfano). these plutons are unaffected by alpine metamorphism (boriani et al., 1990b). the prealps east of lake maggiore are largely characterized by sedimentary covers of the southalpine domain (bertotti et al., 1993). these are permo-mesozoic (pmc) to tertiary (tc) shelf to basin marine formations. lugano volcanites (lv) outcropping on the left side of the valcuvia valley are of permian age (hunziker & zingg, 1980). the insubric line is crosscut by the toce valley and the ticino valley in the w-e reach of lake maggiore (fig. 2). here the narrow (about 2 km wide) canavese zone (zc; southalpine domain) is in tectonic contact with the ivrea-verbano and sesia-lanzo zones to the south and north, respectively. the canavese zone includes many types of rocks, such as gneisses, schists, permian diorite, serpentinites and sedimentary carbonate and siliceous rocks, that are locally strongly deformed, with a low-grade alpine metamorphism (ferrando et al., 2004). west of bellinzona the tail of the bergell pluton (bg) is characterized by tonalite (schmid et al., 1996). the sesia-lanzo zone (sl) is the first unit showing alpine metamorphism (compagnoni et al., 1977). it is composed of rocks derived from the southalpine domain and forming the distal edge of the adria microplate before the alpine collision (austroalpine domain). sl was subdivided by previous authors into: “gneiss minuti”, “micascisti eclogitici” and “ii zona diorito-kinzigitica” where the bedrock crops out underneath the frontal moraines of the orta end moraine system (braakhekke et al., 2020). 2.1. geological setting the bedrock of the ticino-toce mountain basin (fig. 2) can be split into two major domains (dal piaz, 2010): (a) the southalpine domain with a paleozoic basement and the permo-mesozoic sedimentary covers, both lacking alpine metamorphism; (b) the second domain was affected by alpine metamorphic phases that include: the sesia-lanzo zone (sl), the penninic and the helvetic nappes. the second domain is characterized by a stack of basement and cover nappes with high -pressure alpine metamorphism of late cretaceous eocene age and a late eocene-early oligocene greenschist to amphibolite facies overprinting (lepontine dome: frey et al., 1999). the two domains are separated by the periadriatic/insubric lineament, a 1000 km long post-collisional transpressive fault with post-late oligocene to miocene activity. the valleys of lake orta and lake maggiore are situated in the southalpine domain (fig. 2) dominated by palaeozoic metamorphic rocks called massicio dei laghi (mdl), by late variscan volcanic suites and permomesozoic sedimentary covers at the outlets and east of lake maggiore (see geological map of switzerland, 1:500,000; federal office of topography swisstopo 2005; piana et al., 2017). the alpine metamorphism is interpreted to have had only minimal effects on the mdl (rutter et al., 2007), whose main metamorphism is of caledonian (late cambrian-early devonian) to variscan (late devonian-early permian) age (boriani et al., 1990a; pinarelli et al., 1993). the mdl is divided into the ivrea-verbano zone (ivk) and the serie dei laghi (lam) separated by the cossato-mergozzo-brissago (cmb) tectonic line (fig. 2). the ivrea-verbano zone (ivk) is one of the most spectacular sections through lower con 122 fig. 3 longitudinal profiles of the major valleys; those related to the toce catchment are in solid lines, those of the ticino catchment in dashed lines; in dotted line the vedeggio valley related to the transfluence towards the ceresio morainic amphitheatre. blue arrows show the elevation of the major transfluences from the respective glaciers. longitudinal distance from the outern lgm moraines of the verbano according to kamleitner et al. (2022a). monegato g. et al. 123 bordered by a southern marginal shear belt. “gneiss minuti” are albite-white mica gneisses and schists, with a local porphyroclastic texture. locally, "gneiss minuti" complex contains coarse-grained metagranitoids. “micascisti eclogitici” are made of high-pressure (eclogite to blueschist facies) micaschists with jadeitic pyroxene-garnet + glaucophane + chloritoid with intercalated eclogites, glaucophane metabasites and marbles. the term "kinzigite" is used in the alpine literature for indicating high-grade (amphibolite facies) sillimanitefig. 4 photos of glacial landforms and erratic boulders (see table 2) from the ticino-toce systems: a) boulder puffer 11 made of ivk gneiss resting on a rocky relief (right slope of lake orta); b) impressive group of seven right lateral moraines of the verbano glacier lobe on the watershed between the lake maggiore and lake orta basins, supporting many granite boulders (alpe canà); c) sub-rounded boulder vr30 made of gla white granite, which provided a pre-lgm 10be age (alpe canà moraines; kamleitner et al., 2022a); d) small angular boulder vr37 made of lam1 garnet paragneiss (s. michele, eastern slope of lake maggiore, nw of laveno); e) big polished sub-angular boulder vr22 made of aon serpentinite (alpe pala at miazzina on the western slope of lake maggiore); f) velmaio megalith invorio breccia (pmc breccia). other photos of erratic boulders from the orta basin (bugnate 17-18, grassona 25, briallo 33, carcegna 50, colma 20 and armeno 39) are found in braakhekke et al. (2020). photos of boulders vr16, vr31, vr45-46 and vr51-52 from the verbano system are found in kamleitner et al. (2022a). the ticino-toce ice conveyor belts during the last glacial maximum 124 fig. 5 plate of thin section samples (see also table 2): a) vr23, green biotite orthogneiss (lam2); b) vr14, granite (gla); c) vr02, serpentinite (aon); d) vr39, paragneiss (lam1); e) vr37, garnet paragneiss (lam1, fig. 4d), f) vr24, green biotite orthogneiss with myrmekite (lam2); g) vr20, granulite (ivk); h) vr27, garnet orthogneiss (mr1). monegato g. et al. 125 garnet-biotite gneisses of the ivk and of the “ii zona diorito-kinzigitica”. the sl crops out in the lower ossola valley for about 4 km at the anzasca-toce confluence, while it pinches out in the ticino valley near ascona (fig. 2). in the north-western sector, the topmost penninic nappe is the zermatt-saas fee zone (zsfz), which forms a very thin and discontinuous oceanic crust slice in the toce basin (fig. 2). it is predominantly composed of serpentinized ultramafites, associated to mafic rocks (metagabbros, metavolcanites and metasediments) crystallized under high-pressure conditions. towards the east, the zsfz pinches out at the northern tip of lake maggiore. the monte rosa (mr) is an upper penninic continental unit characterized by a large sw-vergent recumbent antiform (berger et al., 2011) with a core composed of high-pressure micaschists and “gneiss minuti” derived from high-grade paleozoic paragneiss (mr1, piana et al., 2017) cropping out along the anzasca valley bottom (fig. 2) and a shell composed of dominant metagranitoid (mr3, frey et al., 1976; piana et al., 2017). these are characterized by k-feldspar megacrystals up to ten centimeters in size, preserved within the alpine schistosity. monte rosa “gneiss minuti” are characterized by albite, fine-grained quartz, white mica, chlorite and garnet. in the micaschists, high-pressure assemblages include chloritoid, phengite, garnet with kyanite, talc, mg-chlorite and glaucophane. the alpine high-pressure assemblages are overprinted by a greenschist tertiary metamorphism (keller et al., 2005) as shown by crystallization of biotite from white mica, albite blastesis (poikiloblasts) and quartz recrystallization to form homogeneous coarse-grained aggregates. the antrona metaophiolite (aon) is a nappe of oceanic crust interposed between the overlying monte rosa and the underlying camughera and moncucco nappes (bigioggero et al., 1981). it crops out on the left side of anzasca valley and more extensively in the upper antrona valley (fig. 2). the aon suite includes serpentinized ultramafites, metagabbros and metabasites (turco & tartarotti, 2006). eclogite metabasite with garnet, amphibole and relict omphacitic clinopyroxene are described by colombi & pfeifer (1986) in the antrona and anzasca valleys. middle penninic unit to the west (toce catchment) is the gran san bernardo (sb). in the central eastern to the eastern sectors of the ticino-toce mountain basin the middle penninic units are characterized by greenschist facies paragneiss and orthogneiss with blueschist relics (bigi et al., 1983). they were grouped (mo-cam-bel) in the geological map of figure 2. the moncucco-orselina (mo) and camughera (cam) are folded together with aon, mr and zs units. they show a medium-grade metamorphic overprinting by the lepontine metamorphism (keller et al., 2005). cam is made of micaschists derived from midto high-grade paleozoic gneisses (paragneiss, orthogneiss, amphibolites) and dominant metagranitoids similar to those of mr3, with alpine high-pressure overprint. mo is composed of a paleozoic basement covered by permocarboniferous sequences including graphitic schists, basic metavolcanites and permian sub-volcanic bodies, suggesting affinity with the gran san bernardo nappe (bigioggero et al., 1981). tambo, bosco and bellinzona nappes are made of paleozoic basement and slices of mesozoic covers and bundner schist (baudin et al., 1993). their lithological setting is similar to that of the monte leone nappe (maxelon & mancktelow, 2005). tambo, bosco, bellinzzona and monte leone nappes are recrystallized under amphibolite facies (biotite, staurolite, garnet). the deep penninic nappes (monte leone, lebendun, simano, lucomagno, leventina, antigorio and verampio, lpn) show a strong lepontine amphibolite facies metamorphic overprint. it is characterized by crystallization of new minerals over the early alpine metamorphism (bigioggero et al., 1981; berger et al., 2011). the lpn are composed of a typical paleozoic basement (paragneisses, orthogneisses, amphibolites), with late paleozoic intrusions and permo-carboniferous to mesozoic sequences similar to the other penninic nappes. these units characterize the innermost sectors of ticino and toce catchments (fig. 2). the ultra-helvetic mesozoic cover sequences and the helvetic gotthard basement (hn), including the permian granitoids (sergeev & steiger, 1995), make up the far northern part of the ticino mountain basin (fig. 2). 2.2. the lgm ticino-toce glacier system the ticino-toce accumulation area is located south of the major rhone and rhine (or vorderrhein) ice domes (fig. 1; kelly et al., 2004; bini et al., 2009). in the inner alpine accumulation areas, additional input of ice could have been added to the ticino basin (4900 km2) by overflowing of the rhone ice dome to the east along bedretto valley via nufenen pass (fig. 2). in leventina valley, the ticino glacier received large ice masses built up in the high-mountain cirques of gotthard pass. downstream of leventina valley, ticino trunk glacier was joined by ice draining blenio and moesa valleys. both tributaries were influenced by likely transfluences from the vorderrhein ice dome via lukmanier, cristallina and greina passes, as well as from the hinterrhein accumulation areas via san bernardino pass (fig. 2). right tributary glaciers of verzasca and maggia valleys fed the ticino glacier together with toce ice overflowing through centovalli valley. on the left side of the ticino valley, another diffluence existed over monte ceneri pass, draining ice directly to the south and towards lugano. in parts, these ice masses united with ice outflowing the adda glacier systems and terminated in the small ceresio lobe south of lake lugano (fig. 1; bini et al., 2009). through an overspill located near ponte tresa, some of the drained ice also re-entered the ticino catchment at valcuvia valley (bini et al., 2009) and merged with the united ticino-toce glacier at the western slope of the campo dei fiori (fig. 1, see fig. 6). advancing southwards, the large ticino valley glacier filled the overdeepened basin of lake maggiore (preusser et al., 2010) and merged with toce glacier coming in from the northwest. in its upper parts, the smaller toce catchment (~1800 km2) was dominated by ice draining through divedroand antigorio valleys, two tributary glaciers with additional linkage to the rhone glacier system adjacent the ticino-toce ice conveyor belts during the last glacial maximum 126 in the north (fig.1, fig. 2). the toce glacier system received overflowing ice from the rhone valley glacier via simplon pass and through a direct link to the rhone ice dome (florineth & schlüchter, 1998; kelly et al., 2004). an ice diffluence existed in the middle of the ossola valley, where ice of the toce catchment did overflow into the ticino catchment along the western vigezzo valley (a tributary of toce valley) and the centovalli valley (a tributary of ticino valley). right tributary glaciers of antrona and anzasca valleys joined the toce trunk glacier downstream. originating in the eastern slope of the monte rosa, ice outflowing anzasca valley represented the major tributary glacier. downstream from the anzasca confluence, one part of the toce glacier branched off to the south into the orta valley, building up the correspondent orta glacier lobe (~85 km2 in area) and a small morainic amphitheater (novarese, 1927; braakhekke et al., 2020). the main branch of the toce glacier, however, continued to the southeast to merge with the ticino glacier. downstream of the confluence at the gulf of borromeo, between stresa and verbania, the merged ticino-toce glacier filled the basin of lake maggiore and advanced several kilometers (about 28 km) towards the sse (fig. 1, fig. 2). the topographic control was reduced and the lgm ticino-toce piedmont lobe terminated on the plain. the bulbous terminus (known as verbano lobe) spread to cover ~380 km2 (kamleitner et al., 2022a). pre-lgm and lgm advances of the ticino-toce glacier built up a multi-ridged, closely stacked end moraine system, interlaced and succeeded by glaciofluvial plains (bini et al., 2014; piana et al., 2017; bernoulli et al., 2017; kamleitner et al., 2022a). the lgm maximum advances of both, orta and verbano lobes, were recently dated to ca. 25 ka and are interpreted to have been followed by a several thousand-year long period of glacier fluctuations near the maximum position (braakhekke et al., 2020; kamleitner et al., 2022a). late lgm readvances (~20-19 ka) were likely followed by rapid ice decay and retreat from the foreland (braakhekke et al., 2020; kamleitner et al., 2022a). the occurrence of large erratic boulders within the orta and verbano morainic amphitheatres was stated by several authors since the 19th century (omboni, 1861; gentilli, 1866; salmojraghi, 1882; sacco, 1892; cai, 1914). the biggest erratics were quarried for building purposes already in prehistory (de marinis, _______________________________ >>>>>> tab. 1 details of erratic boulders of the ortaverbano and ceresio systems lithologically analysed in this study. monegato g. et al. 127 2012) or used as holy sites (e.g. prea guzza). within the orta and verbano morainic amphitheaters, big boulders are not limited to the last glaciation, but were also found external to the lgm frontal moraines (braakhekke et al., 2020; kamleitner et al., 2022a). 3. materials and methods in the present work, provenance analysis was applied to erratic boulders found in the orta, verbano, and ceresio end moraine systems (fig. 1). the respective boulders were located during field campaigns related to different mapping and dating projects (bernoulli et al., 2017, 2018; braakhekke et al., 2020; kamleitner et al., 2022a). in total more than 500 erratic boulders were considered, out of which 105 boulders were chosen for provenance studies as their source rocks were well recognized (tab. 1). erratic boulders were grouped by their source rock on the base of the simplified geological map of the catchments, which derives from bigi et al. (1983), swisstopo (2005) and piana et al. (2017). more than 260 erratic boulders were located in the lower ticino and orta valleys, geographically positioned in a gis database and described in size and roundness type (tab. 1). most of the erratics are related to frontal or lateral moraine ridges but boulders situated on bedrock close to the trimline are also included (fig. 1). the size of the boulders varies from 1 m3 minimum to >300 m3 max (tab. 1, fig. 4). the exposure age of 54 erratic boulders was defined with cosmogenic nuclide exposure dating (braakhekke et al., 2020; kamleitner et al., 2022a). out of these, 19 boulders are related to the maximum advances and 31 located in the withdrawal moraines or in the valley floor. four boulders from the verbano end moraine system were dated to pre-lgm ice advance(s) (vr19, vr42, vr30 and vr45). four more boulders (gudo01, guer01, guer02, paru01) come from the lateglacial deposits in ticino valley. these eight boulders are included in table 1 but not considered in the discussion. a description of the boulder petrography was provided in the field. for 85 boulders (including exposure dated and other selected erratics), thin section analysis was performed in order to recognize the metamorphic facies of gneiss and micaschist lithotypes (fig. 5). an overall 289 erratic boulders related to the ceresio morainic amphitheatre were mapped and inventoried in a gis geodatabase during quaternary geological cartography for the sheet 152 mendrisio-como of the swiss geological atlas 1:25,000 (see bernoulli et al., 2017, 2018). 101 erratic boulders were considered as deposited during pre-lgm glacial advances, whereas 188 boulders are located within limits of the lgm expansion in the geological map (bernoulli et al., 2017). the eleven boulders included in the present work were lithologically recognized (tabs. 1 and 2) and, even if outside the mapped lgm (bini et al., 2014; bernoulli et al., 2017), they yield information about the flowline of this branch of the glacier. 3.1. provenance of the boulders the provenance of more than hundred erratic boulders related to the lgm of the orta, verbano, and ceretab. 2 overview of the geological units of the ticino-toce catchment and the provenance of the studied erratic boulders. the ticino-toce ice conveyor belts during the last glacial maximum sio glacier lobes, was identified using thin section analysis (85 samples) and visual interpretation in the field (30). the petrographic characteristics of the boulders are reported in table 2 and illustrated in fig. 6. boulders show petrographic provenance clustering in the wide area covered by the ticino and toce glacier snouts. an overall 48 samples are related to bedrock units located south of the insubric line, the sector closest to the glacier termini. the most frequently encountered lithologies are those related to the southalpine metamorphic basement (ivk and lam, with three boulders in the orta and 19 in the verbano system, respectively), the permian granites (gla, with three boulders in orta, ten in the verbano system, and one erratic in the ceresio end moraines, respectively) and the lugano volcanites (lv, two erratics in the verbano end moraine system). the occurrence of gla erratics was also documented in till north of sesto calende (omboni, 1861; salmojraghi, 1882). erratic boulders from the sesia-lanzo zone (sl) build a second important petrographic group, particularly in the orta end moraine system (seven boulders in the orta valley and three in the verbano system, respectively). mr and mo-cam-bel units are well represented in the orta system (eight samples), while one boulder (vr27, fig. 5h) was collected in the verbano area. ophiolitic boulders (antrona zone, aon) are present in both orta and verbano amphitheatres with two and seven samples, respectively. in the verbano end moraine system, erratics sourced from the antrona zone are widely scattered. aon erratics were found associated with lateral moraine deposits north of verbania (fig. 4e) and along the western margin of the former verbano lobe. three boulders sampled from verbano frontal moraines show aon signature. one of them (er192) is located 128 fig. 6 distribution and lithology of the studied erratic boulders in the orta-verbano and ceresio morainic amphitheaters. for color codes see legend of fig. 2. red crosses indicate areas where baveno granite boulders (gla unit) were recognized during railway constructions in the 19th century (omboni, 1861; gentilli, 1866; salmojraghi, 1882). mapped moraine ridges (bini et al., 2014; braakhekke et al., 2020; kamleitner et al., 2022a) are shown as red lines. distribution of glaciofluvial and glacial sediments was modified from the geological maps of piedmont (1:250,000; piana et al., 2017) and lombardy (1:250,000; montrasio et al., 1990) and the swiss geological atlas 1:25,000 (bernoulli et al., 2017, 2018). monegato g. et al. just south of lake varese. lower penninic boulders (lpn) are lacking in the orta amphitheatre while 15 and four lpn samples were collected in the verbano and ceresio end moraine systems, respectively. finally, one boulder of the helvetic gotthard massif was collected from monte pian nave (vr36; fig. 6), while one granodioritic boulder, coming from the bergell batholith (bg), was found south of lake varese. in the ceresio sector most of the boulders belong to the southalpine sedimentary covers (tab. 1, fig. 4f); because no local valley glaciers could have developed in the low-elevation sector, these boulders were transported by glacier diffluence. boulder lithologies indicate that both the ticino and the adda branches could have been responsible for erratic transport. as expected from the scarce mixing of the supraglacial fluxes, the distribution of analyzed erratic boulders shows an inhomogeneous lithological distribution. the lithotypes from bedrock of the ossola valley (aon, mr, ivk, sl) are largely distributed in the orta lobe and on the western side of the verbano lobe. nevertheless, erratics sourced from ossola valley were also found in the central part of the end moraine system, south of lake varese. on the other hand, lithotypes of bg, admg and hn, originating from the ticino valley network as well as lugano volcanites (lv) were found only in the very left sector of the verbano end moraine system. in contrast, the lower penninic bedrock (lpn) characterizes the upper catchments of ticino and toce glaciers. occurrence of penninic erratic boulders is common across the verbano lateral-frontal moraine complex. roundness of erratic boulders varies from angular to sub-rounded (tab. 1). most of the angular boulders are located on the outermost frontal and lateral moraines, while those located on internal moraines are mostly sub-angular to sub-rounded. an exception is represented by gla boulders that, despite their position, are mostly sub-rounded (fig.4c). this can be ascribed to the particular surficial exfoliation (ollier, 1967) of granite bedrock on the slopes of the mottarone (fig. 6) and the subsequent shaping during the transportation, even if from short distance. 129 fig. 7 flowlines of the ticino-toce glacier system (extent modified after bini et al. 2009, braakhekke et al., 2020, kamleitner et al., 2022a) during the lgm inferred from erratic boulder lithologies. dashed trajectories in the ceresio lobe are suggested by boulders located outside the pre-lgm limit (bini et al., 2014; bernoulli et al., 2017; no dates available). for symbols see legend of figure 6. the ticino-toce ice conveyor belts during the last glacial maximum 4. discussion 4.1. inferred ice flow paths in the ticino-toce system the distribution of index erratics within the orta, verbano, and ceresio end moraine systems found in this study can be coupled with observations made by early authors. the lithological provenance of granite and gneiss erratic boulders that have been subsequently removed by anthropogenic quarrying activities is reported by cai (1914). it is remarkable that omboni (1861) already noticed that the moraines west of lake maggiore are dominated by boulders of the toce catchment, while those close to the campo dei fiori slope (opposite, eastern side) are characterized by boulders of the inner ticino basement. baveno granite boulders (gla) are common in the lateral moraines (fig. 4b) of the western part of the verbano end moraine system deposited by the toce glacial branch at this point welded with the ticino glacier. however, baveno granite boulders, as well as the presence of this type of rock in lodgment till, were recognized in early excavations for the construction of a railway line between sesto calende and lake varese in the 19th century (i.e. in the eastern frontal sector of the verbano system; fig. 6; omboni, 1861; gentilli, 1866; salmojraghi, 1882). petrological investigations undertaken in this study and from the literature (omboni, 1861; gentilli, 1866; salmojraghi, 1882; cai, 1914) combined with exposure dating of selected erratic boulders and geomorphological analysis of earlier work (braakhekke et al., 2020; kamleitner et al., 2022a) yield crucial insights into glacier flow paths of the ticino-toce glacier during the lgm (fig. 7). boulder lithologies originating from the ossola valley indicate that the lgm orta morainic amphitheatre and the western section of the lgm verbano end moraine system correspond to the flow of the toce glacier. most of the boulders belong to the southalpine basement (ivk and lam), the permian batholith (gla), the sl and mr alpine nappes and the ophiolites (aon). it is remarkable that the inner sector of the toce catchment is scarcely represented in the orta moraines (braakhekke et al. 2020), whereas boulders of the lpn are common in the western frontal moraines of verbano (fig. 6), indicating a significant persistence of the dispersal train. boulders transported by the toce glacier are widely found on lgm lateral and frontal moraines of the verbano amphitheatre, including the sector south of lake varese. this suggests a dominance of the toce glacier over the ticino glacier. ticino glacier may have hence been confined to the eastern flank of the system (fig. 7). the toce system is characterized by a shorter stream course while at the same time being notably steep with accumulation areas reaching above 4000 m a.s.l. in comparison, the ticino catchment is more than two-and-a-half times the size of the toce basin, yet mountain peaks are lower, the slopes are gentler, and the thalweg is longer (fig. 3). an important divergence of the toce glacier was located along the vigezzo valley draining ice towards ticino valley and into high canobbina valley, as testified by glacigenic deposits (boriani & burlini, 1995); again this indicates the predominance of the toce glacier. these thoughts agree well with the palaeoglacier model by seguinot et al. (2018), which shows that the ticino glacier likely reached the mountain front slightly later, where it faced the physical obstacle of the spreading toce piedmont glacial lobe. likely due to ice congestion, flow of the ticino glacier was forced to diverge to the eastsoutheast across monte ceneri pass and to occupy the vedeggio and cassarate valleys (fig. 2). in the ceresio sector, it merged with the branch of the adda glacier system, coming through porlezza valley (bini, 1997; castelletti et al., 2014). the abundance of sedimentary rock boulders indicates that the ticino glacier eroded the sedimentary covers of the area and then formed the main part of the western ceresio lobe ending at arcisate. probably it made also a part of the eastern ceresio lobe, ending at stabio where it merged with the western part of the adda glacier system (bini, 1997; scapozza et al., 2014; bernoulli et al., 2018). in the lower reaches of ticino valley, a second divergence at luino may have promoted ice exchange between valcuvia valley and tresa valley. according to the distribution of erratic boulder lithologies in the orta, verbano, and ceresio end moraine systems, the major lgm ice streams of ticino and toce glaciers are suggested to have been as follows (fig. 7): the lgm orta glacier lobe was mainly fed by the anzasca tributary glacier (braakhekke et al., 2020) with a contribution of ice from the ossola/toce valley glacier in the eastern parts of the lobe. ice from the toce valley glacier built up the western sector of the lgm verbano glacier lobe and possibly extended far towards the southeast, at least during the early phase of the lgm. the ticino glacier dominated the eastern flank of the verbano system, in the lake varese and campo dei fiori sectors. through a diffluence across monte ceneri pass, ticino glacier fed western parts of the ceresio lobe between porto ceresio and arcisate. 4.2. implications for ticino-toce glacier dynamics the complex dynamics of the ticino-toce glacier network were strongly influenced by the asymmetry of the mountain catchments. a key role was played by the highest sector of the toce accumulation area represented by the high monte rosa fletschorn ridgeline, running over 3000 m a.s.l. with peaks over 4000 m a.s.l. the rapid spread of the toce catchment glaciers, taking into account the short travel distances (~100 km of the toce against ~150 km max of the ticino leventina, fig. 3), promoted early arrival of the toce glacier in the piedmont area. the possibly rapid response of the toce catchment to climate changes of mis 3 and the onset of the lgm supports the marked spread of toce ice over a large sector of the verbano piedmont lobe. presumably, the larger but slower ticino glacier was pushed to the east and forced to spread in the prealpine area of the lake lugano region. these results yield interesting implications for the reconstruction of the evolution and interconnections of large glaciated networks in mountain ranges. the fastest glaciers might have played a role in blocking the flow of glaciers with greater inertia and forced transfluences/diffluences if topography allowed 130 monegato g. et al. for it. during the lgm, the alps were covered by a network of interconnected valley glaciers (ivy-ochs et al., 2022). hence, many glacier systems were affected by merging trunk glaciers. the presented data from toce and ticino catchments underlines how the reaction time of neighboring glacier systems may vary due to inherent differences in catchment geometry, especially when the accumulation areas show a strong asymmetry. a similar behavior of ice overflowing into previously non-glaciated valleys forced due to blockage by another glacier was reported for trunk glaciers in the lower inn and salzach valleys (van husen, 2004; reitner et al., 2010), but can be conceivable in other sectors of the alps and in other mountain ranges as well. in addition, palaeoclimatic models suggest that precipitation was irregularly distributed in time and space across the alps contributing to anomalous ice accumulation throughout the lgm time bracket (kuhlemann et al., 2008; luetscher et al., 2015; del gobbo et al., 2022). moreover, the different distribution of major ice-flows can be related to how the accumulation areas, and specifically the major ice-domes, reacted to the climate change promoting the spread of the glaciers. according to modelling studies on the isere, rhone, and rhine paleoglaciers (coutterrand, 2010; jouvet et al., 2017; cohen et al., 2018), the contribution from different sectors of an accumulation area can be traced from the highest parts to the outlet. glacier simulations further suggest increased basal erosion underneath confluencing ice streams (cohen et al., 2018; jouvet et al., 2021). some valley reaches of the rhine catchment were characterized by very slow advance (cohen et al., 2018), and this characteristic may be inferred for the advance of the ticino glacier through the valley section south of bellinzona, which is up to 4.5 km wide with a very low gradient. the model of seguinot et al. (2018) shows that the toce glacier extended to gravellona toce several times already in the mis 4 and mis 3 cold phases and may have molded the valley outlet. on the other hand, the ticino glacier arrived in the lake maggiore area only during the lgm (seguinot et al., 2018), when the paleoclimatic conditions (del gobbo et al., 2022) allowed the spread of a large glacier and its persistence until the final collapse at about 18 ka (wirsig et al., 2016; ivy-ochs et al., 2022). moreover, the shallow elevation in the lower toce valley bottom and in the gulf of borromeo is in contrast to the deep trough of lake maggiore (cazzini et al., 2020) and may indicate a more effective subglacial carving by the ticino glacier. this may suggest that the toce glacier prevailed at the lgm onset and the ticino glacier at the lgm climax. 5. conclusions the study of the provenance of erratic boulders of the ticino-toce glacier system provides interesting insights into the development of a large lgm glacial network and its outflow in the prealpine and piedmont areas. the distribution of erratic boulders shows a dominance of the toce glacier in the orta lobe and in the western-central sector of the verbano lobe. the lgm orta lobe was predominantly fed by ice from anzasca valley, a right tributary glacier of the toce valley glacier. despite the much larger catchment, lithologies indicative of the ticino glacier are largely limited to the eastern sector of the lgm verbano lobe and the western parts of the ceresio system, where ticino ice merged with the westernmost branch of the adda glacier system. the topographic differences in the overall accumulation areas, with maximum elevations (>4000 m a.s.l.) and steep slopes in the toce catchment, promoted the sudden and rapid spread of the toce glacier, whose path was shorter (<100 km) in comparison to the ticino glacier (around 150 km). the early arrival of toce glacier possibly resulted in the damming of the ticino glacier and fostered the diffluence of ticino ice into the prealpine area to the east, merging with the western branch of the adda glacier, where elevations were too low for hosting independent valley glaciers during the lgm. the dynamics of the two studied lgm glaciers highlight the importance of topography as a driver for ice build-up and development of valley glaciers. faster glaciers may force slower trunk glaciers to a different path. considering the topographic setting of the alpine area this could have been a common phenomenon also in past glaciations. the provenance of boulders can thus provide an important tool for determining glacier flow trajectories that could have been affected by unequal glacier evolution. acknowledgments funding by the swiss national science foundation is gratefully acknowledged [snf grant number 175794, 2017]. the reviews provided by two anonymous reviewers greatly improved our manuscript. we also thank a. fontana (a.e.) for his comments. references baudin t., marquer d., persoz f. (1993) basementcover relationships in the tambo nappe (central alps, switzerland); geometry, structure and kinematics. the geometry of naturally deformed rocks, vol. 15 (3-5). pergamon, oxford, 543553. becker p., seguinot j., jouvet g., funk m. (2016) last glacial maximum precipitation pattern in the alps inferred from glacier modelling. geographica helvetica, 71, 173-187. berger a., schmid s.m., engi m., bousquet r., wiederkehr m. (2011) mechanisms of mass and heat transport during barrovian metamorphism: a discussion based on field evidence from the central alps (switzerland/northern italy). tectonics, 30, 1-17. bernoulli d., ambrosi c., scapozza c., castelletti c., wiedenmayer f. (2017) foglio 1373 mendrisio (parte est) con parte ovest del foglio como. atlante geologico della svizzera 1:25000, carta 152. bernoulli d., ambrosi c., scapozza c., stockar r. schenker f. l., gaggero l., antognini m., bronzini s. (2018) foglio 1373 mendrisio (parte est) con parte ovest del foglio como. atlante geologico della svizzera 1:25000, note esplicative 152. data.geo.admin.ch/ch.swisstopo.geologiegeologischer_atlas/erlaeuterungen/ga25-erl 131 the ticino-toce ice conveyor belts during the last glacial maximum 152.pdf bertotti g., picotti v., bernoulli d., castellarin a. (1993) from rifting to drifting: tectonic evolution of the south-alpine upper crust from the triassic to the early cretaceous. sedimentary geology, 86, 5376. bigi g., castellarin a., coli m., dal piaz g.v., sartori r., scandone p., vai g.b. (1983) structural model of italy. scale 1:500.000. c.n.r., progetto finalizzato geodinamica. selca, firenze. bigioggero b., boriani a., colombo a., tunesi a. (1981) età e caratteri petrochimici degli ortogneiss della zona moncucco-orselina nell'area ossolana. rendiconti società italiana di mineralogia e petrografia, 38, 207-218. bini a. (1997) stratigraphy, chronology and paleogeography of quaternary deposits of the area between the ticino and olona rivers (italyswitzerland). geologia insubrica, 2, 21-46. bini a., cita m.b., gaetani m. (1978) southern alpine lakes hypothesis of an erosional origin related to the messinian entrenchment. marine geology, 27, 271-288. bini a., buoncristiani j.f., couterrand s., ellwanger d., felber m., florineth d., graf h.r., keller o., kelly m., schlüchter c., schoeneich p. (2009) die schweiz während des letzteiszeitlichen maximums (lgm). bundesamt für landestopografie swisstopo, wabern. bini a., bussolini c., turri s., zuccoli l. (2014) carta geologica alla scala 1:100.000 dell’anfiteatro morenico del verbano. sibrium, 28, 25-77. boriani a., burlini l., sacchi r. (1990a) the cossatomergozzo-brissago line and the pogallo line (southern alps, northern italy) and their relationships with the late-hercynian magmatic and metamorphic events. tectonophysics, 182, 91-102. boriani a., giobbi origoni e., borghi a., caironi v. (1990b) the evolution of the “serie dei laghi” (strona-ceneri and scisti del laghi): the upper component of the ivrea-verbano crustal section; southern alps, north italy and ticino, switzerland. tectonophysics, 182, 103-118. boriani a., burlini l. (1995) carta geologica della valle cannobina. dipartimento di scienze della terra dell’università degli studi di milano, milano. braakhekke j., ivy-ochs s., monegato g., gianotti f., martin s., casale s., christl m. (2020) timing and flow pattern of the orta glacier (european alps) during the last glacial maximum. boreas, 49, 315-332. cai (1914) i massi erratici nella regione dei tre laghi. premiata tip. succ. fratelli fusi, pavia. castelletti l., livio f., martinelli e., michetti a.m., motella de carlo s. (2013) recenti ricerche paleoecologiche in ambito lariano svolte in collaborazione fra università dell’insubria e laboratorio di archeobiologia dei musei civici di como. rivista archeologica dell’antica provincia e diocesi di como, 195, 115-128. cazzini f.f., amadori c., bosino a., fantoni r. (2020) new seismic evidence of the messinian paleomorphology beneath lake maggiore area (italy). italian journal of geosciences, 139, 195-211. compagnoni r., dal piaz g.v., hunziker j.c., gosso g., lombardo b., williams p.f. (1977) rendiconti della società geologica italiana di mineralogia e petrologia, 33, 281-334. coutterand s. (2010) etude géomorphologique des flux glaciaires dans les alpes nord-occidentales au pléistocène récent: du maximum de la dernière glaciation aux premières étapes de la déglaciation, phd thesis, université de savoie, savoie. coutterand s., schoeneich p., nicoud g. (2009) le lobe glaciaire lyonnais au maximum würmien glacier du rhône ou/et glaciers savoyards? in deline p., ravanel l. (eds.): neige et glace de montagne. reconstitution, dynamique, pratiques, 11-22. collection edytem, cahiers de géographie, le bourget-du-lac cedex. cohen d., gillet-chaulet f., haeberli w., machguth h., fischer u.h. (2018) numerical reconstructions of the flow and basal conditions of the rhine glacier, european central alps, at the last glacial maximum. cryosphere, 12, 2515-2544. colombi a., pfeifer h.r. (1986) ferrogabbroic and basaltic meta-eclogites from the antrona maficultramafic complex and the centovalli-locarno region (italy and southern switzerland)first results. schweizerische mineralogische und petrographische mitteilungen, 66: 99-11 cummings d.i., russell h.a.j. (2018) glacial dispersal trains in north america. journal of maps, 14(2), 476-485. doi: 10.1080/17445647.2018.1478752 dal piaz g.v. (2010) the italian alps: a journey across two centuries of alpine geology, in: beltrando, m., peccerillo, a., mattei, m., conticelli, s., doglioni, c. (eds.), the geology of italy: tectonics and life along plate margins. journal of the virtual explorer, 36. del gobbo c., colucci r.r., monegato g., žebre m., giorgi f. (2022) atmosphere-cryosphere interactions at 21 ka bp in the european alps. climate of the past discussions. doi: 10.5194/cp-2022-43 de marinis r.c. (2012) l’arte figurativa schematica nella cultura di golasecca. preistoria alpina, 46, 367-369. evans d.j.a. (2003) ice-marginal terrestrial landsystems: active temperate glacial margins. in: d.j.a. evans (ed.) glacial landsystems. arnold, london, 12-43. ferrando s., bernoulli d., compagnoni r. (2004) the canavese zone (internal western alps): a distal margin of adria. schweizerische mineralogische und petrographische mitteilungen, 84, 237-256. finckh p. (1978) are southern alpine lakes former messinian canyons? geophysical evidence for preglacial erosion in the southern alpine lakes. marine geology, 27, 289-302. florineth d., schlüchter c. (1998) reconstructing the last glacial maximum (lgm) ice surface geometry and flowlines in the central swiss alps. eclogae geologicae helvetiae, 91, 391-407. frasca m., vacha d., chicco j., troilo f., bertolo d. 132 monegato g. et al. (2020) landslide on glaciers: an example from the western alps (cogneitaly). journal of mountain science, 17, 1161-1171. doi: 10.1007/s11629-019-5629-y frey m., hunziker j.c, o'neil j.r., schwander h.w. (1976) equilibrium-disequilibrium relations in the monte rosa granite, western alps; petrological, rb-sr and stable isotope data. contributions to mineralogy and petrology, 55, 147-179. frey m., desmons j., neubauer f. (1999) the new metamorphic map of the alps. schweizerische mineralogische und petrographische mitteilungen, 79, 1-4. gentilli a. (1866) sopra un fenomeno del terreno glaciale di vergiate. atti società italiana di scienze naturali, 9, 426-427. gianotti f., forno m.g., ivy-ochs s., monegato g., pini r., ravazzi c. (2015) stratigraphy of the ivrea morainic amphitheatre (nw italy): an updated synthesis. alpine and mediterranean quaternary, 28, 29-58. goodsells b., hambrey m.j., glasser n. (2005) debris transport in a temperate valley glacier: haut glacier d’arolla, valais, switzerland. arctic, antarctic, and alpine research, 37, 218-232. graf a., akçar n., ivy-ochs s., strasky s., kubik p.w., christl m., burkhard m., wieler r., schlüchter c. (2015) multiple advances of alpine glaciers into the jura mountains in the northwestern switzerland. swiss journal of geosciences, 108, 225238. hantke r. (1983) eiszeitalter die jüngste erdgeschichte der schweiz und ihrer nachbargebiete. westliche ostalpen mit ihrem bayerischen vorland bis zum inn-durchbruch und südalpen zwischen dolomiten und mont blanc. ott verlag, thun. hunziker j.c., zingg a. (1980) lower palaeozoic amphibolite to granulite facies metamorphism in the ivrea zone (southern alps, northern italy). schweizerische mineralogische und petrographische mitteilungen, 60, 181-213. imhof m.a., cohen d., seguinot j., aschwanden a., funk m., jouvet g. (2019) modelling a paleo valley glacier network using a hybrid model: an assessment with a stokes ice flow model, journal of glaciology, 65, 1000-1010. doi: 10.1017/jog.2019.77 ivy-ochs s., lucchesi s., baggio p., fioraso g., gianotti f., monegato g., graf a., akçar n., christl m., carraro f., forno m.g., schlüchter c. (2018) new geomorphological and chronological constraints for glacial deposits in the rivoli-avigliana end-moraine system and the lower susa valley (western alps, nw italy). journal of quaternary science, 33(5), 550-562. ivy-ochs s., monegato g., reitner j.m. (2022) the alps: glacial landforms from the last glacial maximum. in: palacios, d., hughes, p.d., ruiz, j.m.g., de andrés, n. (eds.), european glacial landscapes: maximum extent of glaciations. elsevier, amsterdam, 449-460. jouvet g., seguinot j., ivy-ochs s., funk m. (2017) modelling the diversion of erratic boulders by the valais glacier during the last glacial maximum. journal of glaciology, 63, 487-498. doi: 10.1017/jog.2017.7 jouvet g., cordonnier g., kim b., lüthi m., vieli a., aschwanden a. (2021) deep learning speeds up ice flow modelling by several orders of magnitude. journal of glaciology, 1-14. doi: 10.1017/jog.2021.120 kamleitner s., ivy-ochs s., monegato g., gianotti f., akçar n., vockenhuber c., christl m., synal, h.a. (2022a) the ticino-toce glacier system (swissitalian alps) in the framework of the alpine last glacial maximum. quaternary science reviews, 279, 107400. kamleitner s., ivy-ochs s., manatschal l., akçar n., christl m., vockenhuber c., hajdas i., synal h.a. (2022b) last glacial maximum glacier fluctuations on the northern alpine foreland: geomorphological and chronological reconstructions from the rhine and reuss glacier systems. geomorphology. doi: 10.1016/j.geomorph.2022.108548 keller l.m., hess m., fügenschuh b., schmid s.m. (2005) structural and metamorphic evolution of the camughera-moncuco, antrona and monte rosa units southwest of the simplon line, erstern alps. ecloagae geologicae helvetiae, 98, 19-49. kelly m.a., buoncristiani j.f., schlüchter c. (2004) a reconstruction of the last glacial maximum (lgm) ice-surface geometry in the western swiss alps and contiguous alpine regions in italy and france. eclogae geologicae helvetiae, 97, 57-75. kuhlemann j., rohling e.j., krumrei i., kubik p., ivyochs s., kucera m. (2008) regional synthesis of mediterranean atmospheric circulation during the last glacial maximum. science, 321, 1338-1340. larson p.c., mooers h.d. (2004) glacial indicator dispersal processes: a conceptual mode. boreas, 33, 238-249. luetscher m., boch r., sodemann h., spötl c., cheng h., edwards r. l., frisia s., hof f., müller w. (2015) north atlantic storm track changes during the last glacial maximum recorded by alpine speleothems. nature communications, 6, 6344. doi: 10.1038/ncomms7344 maxelon m., mancktelow n.s. (2005) threedimensional geometry and tectonostratigraphy of the pennine zone, central alps, switzerland and northern italy. earth-science reviews, 71, 171227. menzies j., van der meer j.j.m., shilts w.w. (2017) sublacial processes and sediments. in: j. menzies, j.j.m. van der meer (eds.) past glacial environments, pp. 105-158. mcclenaghan m.b., bobrowsky p.t., hall g.e, cook s.j. (2001) drift exploration in glaciated terrain. the geological society, london. monegato g., ravazzi c., donegana m., pini r., calderoni g., wick l. (2007) evidence of a twofold glacial advance during the last glacial maximum in the tagliamento end moraine system (eastern alps). quaternary research, 68(2), 284302. 133 the ticino-toce ice conveyor belts during the last glacial maximum doi: 10.1016/j.yqres.2007.07.002 monegato g., scardia g., hajdas i., rizzini f., piccin a. (2017) the alpine lgm in the boreal ice-sheets game. scientific reports, 7(1), 2078. novarese v. (1927) gli apparati morenici würmiani del lago maggiore e del lago d’orta. bollettino dell’ufficio geologico italiano 8, 1-64. oberhänsli r., bousquet r., engi m., goffé b., gosso g., handy m., höck v., koller f., lardeaux j.m., polino r., rossi p., schuster r., schwartz s., spalla m.i. (2004) metamorphic structure of the alps. in: explanatory note to the map "metamorphic structure of the alps", commission for the geological map of the world, paris. ollier c.d. (1967) spheroidal weathering, exfoliation and constant volume alteration. zeitschrift fur geomorphologie, 11, 103-108. omboni g., (1861) i ghiacciai antichi ed il terreno erratico della lombardia. atti società italiana di scienze naturali, 6, 232-299. piana f., fioraso g., irace a., mosca p., d’atri a., barale l., falletti p., monegato g., morelli m., tallone s., vigna g.b. (2017) geology of piemonte region (nw italy, alps-apennines junction zone). journal of maps, 13(2), 395-405. pinarelli l., boriani a., del moro a. (1993) the pb isotopic systematics during crustal contamination of subcrustal magmas: the hercynian magmatism in the serie dei laghi (southern alps, italy). lithos, 31, 51-61. preusser f., reitner j.m., schlüchter c. (2010) distribution, geometry, age and origin of overdeepened valleys and basins in the alps and their foreland. swiss journal of geosciences, 103, 407-426. reber r., akçar n., ivy-ochs s., tikhomirov d., burkhalter r., zahno c., lüthold a., kubik p.w., vockenhuber c., schlüchter c. (2014) timing of retreat of the reuss glacier (switzerland) at the end of the last glacial maximum. swiss journal of geosciences, 107, 293-307. reitner j.m., gruber w., römer a., morawetz r. (2010) alpine overdeepenings and paleo-ice flow changes: an integrated geophysicalsedimentological case study from tyrol (austria). swiss journal of geosciences, 103, 385-405. rutter e., brodie k., james t., burlini l. (2007) largescale folding in the upper part of the ivreaverbano zone, nw italy. journal of structural geology, 29, 1-17. sacco f. (1892) l’anfiteatro morenico del lago maggiore. annali reale accademia d’agricoltura di torino, 43, 1-252. salmojraghi f. (1882) alcune osservazioni geologiche sui dintorni di comabbio. atti società italiana di scienze naturali, 25, 268-290. scapozza c., castelletti c., soma l., dall’agnolo s., ambrosi c. (2014) timing of lgm and deglaciation in the southern swiss alps. géomorphologie: relief, processus, environnement, 20, 307-322. doi: 10.4000/geomorphologie.10753 seguinot j., delaney i. (2021) last-glacial-cycle glacier erosion potential in the alps. earth surface dynamics, 9, 923-935. doi: 10.5194/esurf-9-923-2021 seguinot j., ivy-ochs s., jouvet g., huss m., funk m., preusser f. (2018) modelling last glacial cycle ice dynamics in the alps. the cryosphere, 12(10), 3265-3285. doi: 10.5194/tc-12-3265-2018 sergeev s.a., steiger r.h. (1995) caledonian and variscan granitoids of the gotthard massif: new geochronological and geochemical results. schweizerische mineralogische und petrographische mitteilungen , 75, 315-316. schmid s.m., pfiffner o.a., froitzheim n., schönborn g., kissling e. (1996) geophysical-geological transect and tectonic evolution of the swiss-italian alps. tectonics, 15, 1036-1064. shilts w.w. (1982) glacial dispersal: principles and practical applications. geoscience canada, 9, 4247. shilts w.w. (1993) geological survey of canada’s contributions to understanding the composition of glacial sediments. canadian journal of earth sciences, 30, 333-353 swisstopo (2005) geological map of switzerland, 1:500.000; federal office of topography, wabern. turco f., tartarotti p. (2006) the antrona nappe: lithostratigraphy and metamorphic evolution of ophiolites in the antrona valley (pennine alps). ofioliti, 31, 207-221. van husen, d. (2004) quaternary glaciations in austria. in: j. ehlers, p. l. gibbard (eds.), quarternary glaciations-extent and chronology. developments in quaternary science, 2, part i: europe, 401-412. višnjević v., herman f., prasicek g. (2020) climatic patterns over the european alps during the lgm derived from inversion of the paleo-ice extent. earth planet science letters, 538, 116185. winterberg, s., picotti, v., willett, s.d., (2020) messinian or pleistocene valley incision within the southern alps. swiss journal of geosciences, 113, 7. wirsig c., zasadni j., christl m., akçar n., ivy-ochs s. (2016) dating the onset of lgm ice surface lowering in the high alps. quaternary science reviews 143, 37-50. ms. received: october 27, 2022 revised: november 22, 2022 accepted: november 25, 2022 avaiable online: december 22, 2022 134 monegato g. et al. imp.cannillo& map of the geological and geomorphological sites of the malfatano coast in sw sardinia: a contribution to the knowledge of the island’s geodiversity cataldo cannillo, felice di gregorio & antonio eltrudis dipartimento di scienze della terra università degli studi di cagliari laboratorio di geologia ambientale via trentino, 51 09127 cagliari – geoam@unica.it abstract: c. cannillo et al., map of the geological and geomorphological sites of the malfatano coast in sw sardinia: a contribution to the knowledge of the island’s geodiversity. (it issn 0394-3356, 2005). the area between cape malfatano and cape spartivento is emblematic of sardinia’s geology, especially with respect to the palaeozoic basement, whose lowermost part, the bithia formation (precambrian-lower cambrian?), crops out in this sector. compared to the tectonic setting typical of the outer zone of the sardinian segment of the south-european hercynian chain, this sector constitutes an anomaly, in which the metamorphism and deformation are more pronounced than in the sulcis-iglesiente region as a whole. another interesting feature of this area is the granitoid rock outcrop (cape spartivento orthogneiss) dated to the sardic phase of the middle ordovician that, elsewhere in the sardinian hercynian basement, is represented essentially by volcanic products. the geosites have been classified according to genetic processes (stratigraphic, metamorphic, magmatic, structural) whose importance has been evaluated on the basis of their being exemplary of geological evolution, of their chronostratigraphic, palaeoenvironmental and educational value. based on these criteria a number of geosites have been identified, where the following features can be observed: the cape spartivento orthogneiss, of special interest because of the effects created by intense hercynian deformation (penetrative schistosity with pronounced stretching lineation of the deformed crystals); the lithologic sequences of the bithia formation, with mylonitic and cataclastic bands, outcrops of stretched pebble metaconglomerate, again produced during hercynian deformation phases, and layers of metalimestone; the significant genetic, magmatic and lithologic aspects of hercynian granites; the intrusive relationships of the hercynian granitoid rocks with the metamorphic basement and of later dyke intrusions intersecting the contacts; ductile deformation structures in the hercynian basement with multiphase folding especially at the mesoscopic scale; brittle deformation structures sometimes with well exposed slickensides and slickenside striae; unconformity between the hercynian basement of the bithia formation and the conglomerate and eolianite deposits, evidence of ancient marine levels and palaeoclimates during the late pleistocene different to present day climates. the geomorphological sites identified in the area have been grouped together according to the genetic processes that created them (fluvial, meteoric, gravitational, littoral, eolian, etc.). on the map a symbol is used to denote the type of geomorphological site (point, linear or areal) defined according to its physical features and level of importance (local, regional, etc.). sites are numbered and a brief description is provided. the level of importance has been assigned according to the following evaluation criteria: exemplary of geomorphological evolution; palaeo-geomorphological evidence; educational value; scenic value. as for the geographical and physical features, the geomorphological forms in the malfatano area were created largely by littoral, eolian, fluvial, slope and gravitational processes, influenced by littoral processes. a number of areas have also been delineated on the map that stand out not so much for their specific forms but rather for their landscape qualities and geomorphological interest as a whole. these include the malfatano ria, a cove where the coastline is submerging, the bay of tuaredda and some tracts inland, the extension of the submarine relief, characterized by ridges, peaks, deep incisions and bizarre forms of erosion on meta-sandstone and meta-siltstone, granite and orthogneiss. the map of the geological and geomorphological sites described summarizes the results of a comprehensive investigation that entailed accurate small scale surveying and photointerpretation of the geoand geomorphic sites along the malfatano coast. a number of interesting examples have been identified that are evidence of the area’s significant geodiversity. riassunto: c. cannillo et al., carta dei geositi e geomorfositi della costa di capo malfatano nella sardegna sud-occidentale: un contributo alla conoscenza della geodiversità dell’isola. (it issn 0394-3356, 2005). l’area tra capo malfatano e capo spartivento rappresenta un settore emblematico della geologia della sardegna, soprattutto per quanto riguarda il basamento paleozoico, di cui affiora la parte basale, costituita dalla formazione di bithia (?precambriano-cambriano inf.). questo settore, infatti, costituisce un’anomalia nel quadro metamorfico-deformativo che caratterizza la zona esterna del segmento sardo della catena ercinica sud-europea, in quanto presenta un metamorfismo ed una deformazione più accentuati, rispetto a quelli della più ampia regione del sulcis-iglesiente. un altro aspetto che rende l’area particolarmente interessante è la presenza di affioramenti di rocce granitoidi (ortogneiss di capo spartivento) riferibili alla fase sarda dell’ordoviciano medio che, altrove, nel basamento ercinico della sardegna, manifesta essenzialmente prodotti vulcanici. la classificazione dei geositi è stata effettuata in base ai processi genetici (stratigrafico, metamorfico, magmatico, strutturale) nell’ambito dei quali si è operata una valutazione sulla base dell’esemplarità evolutiva geologica, dell’interesse cronostratigrafico, paleoambientale e dell’esemplarità didattica. in base a tali criteri è stato individuato un certo numero di geositi nei quali è possibile osservare: gli ortogneiss di capo spartivento, interessanti soprattutto per gli intensi effetti deformativi riconducibili alle fasi tettoniche erciniche (scistosità penetrativa con marcata lineazione di allungamento dei cristalli deformati); le sequenze litologiche della formazione di bithia, con fasce cataclastico milonitiche, affioramenti di metaconglomerati con fenomeni di allungamento di clasti, sempre per effetto delle fasi deformative erciniche e livelli di metacalcari; il quaternario italian journal of quaternary sciences 18(1), 2005 volume speciale, 257-266 258 c. cannillo et al. 1. introduction the purpose of this work is to illustrate the map of the geological and geomorphological sites of the malfatano coast in se sardinia. the map, which is one of the first examples of its kind on a large scale, has been drawn up using data gathered from accurate field observations and from photointerpretation which formed the basis for the identification, classification and evaluation of the different sites of geological and geomorphological interest. 2. geological-structural features of the hercynian basement in sardinia a complete section of the southern european hercynian chain crops out in sardinia (which forms its ancient basement) stretching from the outer zones in sw sardinia to the inner zones, cropping out in the ne of the island. the nw-se trending chain is characterized by shortening and by a tectonic-metamorphic zoning typical of orogenesis resulting from continental collision. the polarity of metamorphic rocks changes gradually from the anchizone in sw sardinia to the amphibolite facies in the ne, accompanied by an equally well-defined change in structural style. structurally the bedrock is characterized by sw striking hercynian thrust (carmignani et al., 1987), interposed between the metamorphic complex for the most part in the amphibolite facies of n sardinia and a highly deformed but essentially autochthonous outer zone with thrusts and folds that crop out in the sw of the island. in the outer zone, which crops out extensively in the iglesiente region, the pre-middle ordovician succession attests to the passage from a lower cambrian terrigenous shelf (bithia formation, nebida formation; cocozza, 1979) interbedded with basic-to-intermediate volcanic rocks likely associated with simultaneous rifting, to a lagoonal environment with oolitic bars (uppermost part of the nebida formation). the mostly terrigenous sediments of the nebida formation pass upwards into the thick carbonate sequence of the gonnesa formation, composed of tidal flat dolomites and limestones, broken up by extensional tectonics into basins and structurally high areas (rasetti, 1972; gandin et al., 1974; boni & cocozza, 1978; vai, 1982; cocozza & gandin, 1990). this formation is overlain by the cabitza formation that demarcates drowning of the carbonate shelf (gandin & pillola, 1985; cocozza & gandin, 1990). 3 the outcropping palaeozoic basement of malfatano area 3.1 bithia formation the most extensive part of the study area is composed of a succession of metamorphic rocks belonging to the bithia formation that crops out in the sw tip of the island along a narrow belt girding the cape spartivento orthogneiss. because of intense tectonization, the actual thickness of this formation is uncertain though apparent thickness is more than 600 m. this is a siliclastic succession composed largely of phyllite, metaquartz arenite and metasandstone interbedded with metaconglomerate and marble. outcrops of metaconglomerate up to a few metres thick are located near to the coast between punta de s’ega de su tramatzu and cala de su senzu, originally poorly sorted polygenic conglomerate. the gli aspetti significativi degli affioramenti di graniti ercinici, genetici magmatici e litologici; i rapporti intrusivi dei granitoidi ercinici con il basamento metamorfico e quelle delle successive intrusioni di corpi filoniani che ne intersecano i contatti; le strutture deformative duttili nel basamento ercinico, presenti con pieghe polifasiche soprattutto alla scala mesoscopica; le strutture deformative fragili presenti talora con specchi di faglia ben esposti e relative strie; la discordanza tra basamento ercinico della formazione di bithia e depositi conglomeratici ed eolianitici che testimoniano antichi livelli marini e paleoclimi del pleistocene superiore differenti da quelli attuali. i geomorfositi rilevati nell’area sono stati raggruppati sulla base del processo genetico che ha determinato la loro formazione (fluviale, meteorico, gravitativo, litorale, eolico, ecc.). ciascun geomorfosito è indicato sulla carta da un simbolo che identifica il tipo (puntuale, lineare o areale) in funzione delle caratteristiche fisiche, ed il livello di importanza (locale, regionale, ecc.). un numero di identificazione rimanda ad una specifica descrizione sintetica. il livello di importanza è stato definito in base ai seguenti criteri di valutazione: esemplarità evolutiva geomorfologica (processi); testimonianza paleo-geomorfologica; esemplarità didattica (forme); valenza scenica. in relazione alle caratteristiche geografico-fisiche, nell’area prevalgono numericamente i geomorfositi ricondicibili a processi litorali, eolici, fluviali e di versante, gravitativi con influenza di processi litorali. nella carta sono state anche delimitate alcune aree che si distinguono non tanto per le specifiche forme presenti, quanto per il loro interesse paesaggistico e geomorfologico d’insieme. tra queste, la ria di malfatano, insenatura testimoniante l’evoluzione di una costa di sommersione, la baia di tuaredda e alcuni tratti dell’entroterra caratterizzati dall’evoluzione subaerea del rilievo, con crinali, culminazioni, incisioni vallive e peculiari su metarenarie e metasiltiti, graniti e ortogneiss. la carta dei geositi e dei geomorfositi rappresenta la principale sintesi grafica di un’analisi integrata condotta tramite accurati rilevamenti di dettaglio e fotointerpretazione dei geositi e dei geomorfositi dell’area costiera di malfatano, ove sono stati riscontrati interessanti elementi che ne documentano una elevata geodiversità. keywords: geosites, geomorphosites, geodiversity, malfatano coast, south sardinia. parole chiave: geositi, geomorfositi, geodiversità, costa di malfatano, sardegna meridionale. highly deformed clasts, embedded in an arenite quartzfeldspar matrix, are composed mostly of fragments of grey and black (lydite) quartzite from vein quartz. outcrops of pale grey marble are scattered throughout the area. these range from the metre-thick layers near sa bidda beccia, monte corilla, p.ta de isurderas to 15-20 m thickness at cape malfatano. the bithia formation is interpreted as a regressive trend terrigenous succession that formed on a continental margin (junker & schneider, 1983; gandin, 1987; gandin et al., 1987). a very low grade, upward decreasing (junker & schneider, 1983) hercynian metamorphism has been described for this formation (palmerini & palmerini sitzia, 1978). based on its stratigraphic position beneath the infracambrian nebida formation (junker & schneider, 1979; minzoni, 1981; carannante et al., 1984), and on the correlations with precambrian formations elsewhere in europe, the bithia formation has been dated to the upper precambrian (cocozza, 1979). a tentative precambrian age has also been reported based on a few poorly preserved acritarchs (pittau demelia & del rio, 1982), though the echinoderm plates discovered within the interbedded carbonate rocks also suggests a lower cambrian age (gandin, 1987). on the whole, the main schistosity of the bithia formation forms a dome (cape spartivento dome) with a radius of roughly 10 km and gently north-dipping axis. in the middle of this dome-like structure the more strongly metamorphosed complex crops out. carmignani et al. (1994) interpret the dome at cape spartivento as the metamorphic core complex which formed following a major deformation phase associated with the crustal thickening resulting from tectonic shortening during the hercynian, which occurred in the rest of the outer zone. 3.2 cape spartivento orthogneiss the orthogneiss crops out near to cape spartivento and tuaredda, and is also referred to in the literature as “monte filau orthogneiss”. these orthoderivatives in amphibolite facies of granitoids, dated to the ordovician magmatism that affected the whole island, were transformed into orthogneiss by the hercynian tectonic-metamorphic event as the radiometric age of 280 ma determined for the biotite indicates. the u-pb zircon age of 478±16 ma for the orthogneiss (delaperrière & lancelot, 1989; 449 ma: ludwig & turi, 1989), dates these magmatites to the ordovician. the orthogneiss complex at cape spartivento intrudes into the m. settiballas schists and is tectonically related with the overlying bithia formation (sassi & visonà, 1989; sassi, 1990). the gneiss formation is composed largely of medium-to-coarse grained orthogneiss having a schisty-augen texture in which the quartz and k-feldspar phenocrystals, with grain size normally over 1 cm, are oriented in the same direction and embedded in phylosilicates (biotite and to a lesser degree muscovite). centimetre-to-metre size fine-grained banded aplitic gneisses (original dykes) also occur within the orthogneiss. these contain fusiform blackish andalusite aggregates that give rise to a pronounced stretching lineation and blastomylonitic and cataclastic gneiss. the latter forms the outermost portions of the gneiss 259map of the geological ... body, in direct contact with the overlying bithia formation. the cape spartivento orthogneisses crop out regularly throughout the central-eastern part of the study area and in a few isolated outcrops, including those near to the padiglioni islet. 3.3 hercynian magmatism the hercynian magmatism is represented both by intrusive rocks and dyke complexes. the intrusive rocks are essentially granodioritic and leucogranitic in composition, the former cropping out in the southern part of capo spartivento, the latter in the northern part. the sub-vertical chiefly nw-se trending dyke complex, which intrudes the metamorphic basement and the hercynian granitoid rocks, is composed of sporadic quartz, rhyolite and andesite-basalt dykes. 4. quaternary deposits the oldest outcrops of quaternary deposits in the area are dated to the upper pleistocene and are represented by the “ancient alluvia” and marine-littoral sediments. the predominantly alluvial cone/plain fluvial sediments consist of more or less compacted conglomerate, gravel and sand often with abundant reddish silty-clay matrix. in the areas comprised between the hills and the small coastal plains these deposits are reincised and terraced. this coarse clastic material contains angular or slightly rounded on average centimetre to decimetre sized clasts within an abundant reddish clayey-ferruginous matrix. they are believed to have been deposited in wet and cold climatic conditions by glacial runoff during the pleistocene. on the pediment (or erosion glacis) developed mostly on palaeozoic crystalline rocks, these debris aprons are fairly discontinuous and thin (from a few decimetres to a few metres thick). locally, in the most sheltered coves, marine-littoral sediments of the tyrrhenian have deposited directly on the palaeozoic basement, generally perched up to 3-4 m above the actual sea level (“strombus-containing tyrrhenian bench” auct.) (vardabasso, 1956; ulzega & ozer, 1982), composed of conglomerate and calcareous cemented sandstone and biocalcarenite, generally containing a warm sea fossil association of lamellibranchs, gastropods, coelenterates, algae. the tyrrhenian marine deposits were followed by a regressive phase represented by eolian würmian sediments with interbedded palaeosoils. outcrops of fossil dunes of würmian age occur especially in proximity of cape malfatano and around the piscinnì tower, where there is interesting and clear evidence of an ancient roman quarry. numerous blocks of these hardened dunes were removed in roman times. holocene deposits consist above all of valley floor and alluvial plain gravel-sand deposits, of beach sands and gravels, of backbeach eolian sands (tuaredda cove), in some places with dune formations extending a few kilometres inland, and of the silty-clayey deposits of the malfatano lagoon. the angular detritus and more or less coarse detritus deposits at the foot of the steepest slopes can also be dated to the holocene. 260 5. geomorphological features the topography of the study area, along the coastal belt and inland, is hilly to mountainous, though of moderate elevation, below 400 m. however energy levels are fairly high on account of the alternation of mountainous/hilly areas with fluvial incisions, in some places narrow and deep with steep rocky slopes, in others taking the form of broad valleys or ledges with almost flat or gently sloping bottom. some of these valleys taper into the sea and in the coastal belt often give way to marshland and lagoons (stagni di pianu spartivento, stagno di piscinnì) bounded seawards by littoral ridges bordering small beaches and sand dunes. the terrain is extremely varied, featuring rocky headlands (e.g. capo malfatano and schiena del siciliano), wide bays and small coves with sandy and pebbly beaches, some with islets of various sizes a short distance from the shore. the drainage pattern is prevalently sub-dendritic and/or centripetal, locally angular where it follows the existing tectonic lines. the streams are small and ephemeral. the main geomorphological structure in the area is the roughly n-s trending flat-bottomed valley depression (malfatano), a little over 1 km wide, which stretches for 4 km down towards the sea into a deep cove forming the natural porto di malfatano harbour. this a classic example of a drowned river valley, the most magnificent on the south coast of sardinia, that was created by the submergence of a pre-existing river eroded valley during the versilian transgression. the inner edge of the cove, which is sheltered from the direct action of wave motion, will eventually be filled in by the gradual deposition of silty-sandy sediments at the land/sea interface. the malfatano coastal belt displays submerged coast features, moulded by subaerial fluvial sediments. in particular, the porto di malfatano is a ria, the lower portion of a palaeo-river valley that was drowned during the versilian transgression. the geomorphosites identified in the study area have been grouped together by the dominant process involved in their formation (fluvial/wash, atmospheric agents, gravitational, littoral, eolian), each group with a different colour. their degree of importance has been determined on the basis of the following evaluation criteria : exemplary of geomorphological evolution (processes); palaeo-geomorphological evidence; educational value (shapes); scenic value. with regard to the physical/geographic features of the study area, the most numerous geomorphosites are those formed by littoral processes namely beaches (including the well known tuarredda beach), islets and stretches of cliffs. the extensive malfatano ria, bears witness to the evolution of a submerged coast. a number of small dune bars of significant geomorphological interest have been chosen to represent the eolian process, though in terms of morphological evolution and landscape, these could be included in the littoral processes. the geomorphosites formed by fluvial/wash processes are represented by entrenched valleys or river gorges, most of which are found inland, as well as forms of selective erosion represented by an outcropping dyke and a typical cone-shaped hill. landforms moulded by atmospheric agents include examples of rock domes, rugged shapes created by rock piles and of honeycombed rocks sculpted by cavernous weathering. only one form of gravitational process is included in the map, represented by a rockfall from the capo malfatano cliffs, a fine example of the evolution of gravitational phenomena in a sheer rocky coast. 6. conclusions: the geosites and geomorphosites map in the light of the above considerations, the segment comprised between cape malfatano and cape spartivento can be regarded as emblematic of sardinia’s geology, especially as concerns the palaeozoic basement whose lowermost part, the bithia formation (?precambrian-lower cambrian) crops out here. in fact within the overall metamorphism/deformation context of the outer zone of the sardinian segment of the south-european hercynian chain, this area is atypical insofar as the metamorphism and deformation are more pronounced than in the sulcis-iglesiente region, of which it is a part. another distinctive and geologically interesting feature of this area is the occurrence of granitoid rock outcrops (cape spartivento orthogneiss) dated to the sardic phase of the middle ordovician which elsewhere in the sardinian hercynian basement is represented largely by volcanic products. the geological sites were identified, classified and evaluated according to the method proposed by barca & di gregorio (1991a), brancucci & d’andrea m. (2002), panizza m. & piacente s. (2002), which considers genetic characteristics (stratigraphic, metamorphic, magmatic, structural). their importance has been evaluated on the basis of their being exemplary of geological/structural evolution, of their chronostratigraphic, palaeoenvironmental and educational value. nineteen geosites (tab. 1) have been identified having the following distinctive genetic features: the cape spartivento orthogneisses, of special interest because of their uniqueness in the regional geological context and the intense deformation effects produced during hercynian tectonic activity (penetrative schistosity with pronounced stretching lineation of the deformed crystals). though the provincial malfatano road 71 cuts across the orthogneiss, near the sa tuaredda nuraghe, the outcrops are relatively inaccessible by road or foot, given the topography of the landscape. because of their geological rarity in sardinia, the geosites have also been chosen according to their accessibility (the road cut near the sa tuaredda nuraghe, the coast around padiglioni islet, the ridge near punta padenti); the lithological sequences of the bithia formation (clearly visible along the hairpin bends of the provincial malfatano road 71), with cataclastic/mylonitic bands, metaconglomerate outcrops near the coast between punta de s’ega de su tramatzu and cala de su senzu, stretched pebbles, again the effect of the c. cannillo et al. 261map of the geological ... tab.1 geosites in the malfatano area and relative parameters of evaluation. geositi nell’area di malfatano e relativi parametri di valutazione. features evaluation genetic process description 1 lens-shaped interbedded metalimestone of the • • • •bithia formation 2 upper pleistocene beach deposits evidence of • • • •ancient marine level 3 unconformity between eolinites of the upper • • • •pleistocene and metamorphic basement 4 contact between hercynian metamorphic rocks, • • •granitoids and dykes 5 metaconglomerate of the bithia formation with • •metasandstone, quarzite and lydite. 6 cape spartivento orthogneiss • • • 7 well exposed stratigraphic succession of the • •bithia formation 8 cape spartivento orthogneiss with well exposed and clearly visibile hercynian metamorphic and • • • deformation features 9 well-exposed hercynian granodiorite outcrops: mineralogic, textural and structural features • • clearly visible 10 well-exposed hercynian leucogranite rock outcrops: mineralogic, textural and structural • • • features clearly visible 11 sub-vertical basic dyke in the metamorphic rocks •of the bithia formation 12 sub-vertical, nw-se trending, outcropping granitic dyke, prominent feature of the landscape, • •intruded between metamorphic rocks of the bithia formation and hercynian leucogranites. 13 sub-vertical, nw-se trending, outcropping quartz dyke, prominent feature of the landscape • • intruding the cape spartivento orthogneisses 14 well visible, steeply dipping, ne-sw trending • •granitic dyke intruding the hercynian leucogranites. 15 fold structures in the metalimestones of the • •bithia formation. 16 slickenside showing transcurrent movement • 17 schistosity and stretching lineations in the cape •spartivento orthogneiss 18 strongly deformed clasts in the bithia formation • •metaconglomerate 19 hercynian late folds in the metasandstone of the • •bithia formation e xe m p la ry o f ge ol og ic al -s tr uc tu ra l ev ol ut io n c hr on os tr at ig ra p hi c ev id en ce p al ae oe nv iro nm en ta l ev id en ce e d uc at io na l v al ue s tr at ig ra p hi c an d m et am or p hi c m ag m at ic m ag m at ic p oi nt li ne ar a re al deformation phases during the hercynian, and layers of metalimestone, the major outcrops occurring near the cape malfatano tower; the significant genetic, magmatic and lithological features of the hercynian granite rocks; the intrusive relationships of the hercynian granitoid rocks with the metamorphic basement and of later dyke intrusions intersecting their contacts (well exposed in the cliffs near the cape spartivento lighthouse); ductile deformation structures in the hercynian basement with multiphase folding especially at the mesoscopic scale (visible along the hairpin bends of the provincial malfatano road n.71); brittle deformation structures sometimes with well exposed slickensides and slickenside striae (a well preserved example can be seen along the path north 262 of mount sa guardia manna); unconformity between the hercynian basement of the bithia formation and the conglomerate and eolianite deposits, evidence of ancient marine levels and palaeoclimates during the late pleistocene different from present day climates (well exposed near the piscinnì tower). in geomorphological terms, particularly significant are the landforms associated with littoral processes (high rocky coasts, coasts indented with deep inlets, beaches nestled in coves, tiny islets and rugged cliffs, etc.), landforms associated with fluvial and slope processes and those produced by weathering. the geomorphological sites surveyed in the area were identified, classified and evaluated following the method proposed by barca & di gregorio (1991b) and barca et al. (1992) based on the genetic process responsible for their formation (fluvial, meteoric, gravitational, littoral, eolian, etc.). each geomorphological site is denoted on the map with a symbol that identifies its features (point, linear or areal) and level of importance (local, regional, etc.) according to a measure of its importance at the geographic scale (barca & di gregorio, 1999; bertacchini et al. 2002b). the sites are numbered and brief specific description is provided. the level of importance has been determined adopting the following evaluation criteria: exemplary of geomorphological evolution (processes); palaeo-geomorphological evidence; education value; scenic value. with regard to the geographical-physical features (tab. 2), the geomorphological sites shaped by littoral processes are by far the most numerous (9) followed by c. cannillo et al. tab. 2 geomorphological sites in the malfatano area and relative parameters of evaluation. siti geomorfologici nell’area di malfatano e relativi parametri di valutazione. features evaluation genetic process description 1 dyke outcropping near the sulcitana state road • • • •195 2 furradroxiu addis ravine • • • 3 cone-topped hill with elongated base near riu • • •perdosu nuraghe 5 dyke outcropping in perda longa area • • • • 4 fluvial valley enclosed northwards by mount • •de sa fossa 6 rio perdosu enclosed fluvial valley • • • • 7 relic forms of meteoric erosion near arcu • •bacca tidoru 8 monte corilla granitoid dome • • 9 rocca di corilla granitoid dome • • 10 honeycombed metamorphic rocks in the luas area. • • 11 tafoni features and relic forms of meteoric erosion • • •in the granite rocks at sa guardia manna 12 rockslide with influence of littoral processes •near the cape malfatano tower 13 tuarredda cuspate beach • • • • 14 cala antoni areddu beach with backbeach dunes • • • • 15 pebbly beach facing ferraglione islet • • 16 tuaredda islet and bay • • • • 17 ferraglione islet • • • 18 padiglioni islet • • • 19 cape spartivento cliffs • • 20 cape malfatano cliffs • • 21 malfatano ria and lagoon • • • • 22 dunes on tuarredda beach • • e xe m p la ry o f ge om or p hi c ev ol ut io n p al ae og eo m or p hi c ev id en ce e d uc at io na l v al ue s ce ni c va lu e fl uv ia l w as h li tt or al m et eo ric p oi nt li ne ar a re al gravitational eolic 263map of the geological ... fig. 1 geosites and geomorphosites map of the capo malfatano coast and relative level of interest. carta dei geositi e geomorfositi della costa di capo malfatano e il relativo livello di interesse. fluvial (6), eolian (1) and gravitational influenced by littoral processes (1). the geosites and geomorphosites identified in the study area, which bear testament to its great geodiversity, have been mapped in the 1:10.000 scale coloured map of geosites and geomorphosites of the malfatano area (se sardinia), the main product, in graphic terms, of the research project concerned with here. the map provides a fundamental tool for land planning and for environmental impact assessment of man-made works as well as for enhancing the value of the area for public enjoyment and educational purposes. the 1:10.000 map of geosites and geomorphological sites summarized in fig. 2, is a concise graphical representation of an analysis conducted by means of accurate and detailed field surveys combined with photo-interpretation of the malfatano coast. some interesting features have been identified that bear witness to the geodiversity of the area (bertacchini m. et al.,1999; carton et al. 2003; piacente & poli, 2003). the educational and tourist-cultural value of these geosites and geomorphological sites is as yet little appreciated and suitable measures are required for conserving and enhancing the geologic-geomorphic heritage. a number of areas have also been delineated in the map, which provides a valuable tool for geotourism and geoconservation (maciocco, 1988; poli & bini, 2002), that stand out not so much for their specific landforms but rather for their landscape qualities and geomorphic interest as a whole. these include the malfatano ria, a cove that is testament to the evolution of the submerging coastline, the bay of tuaredda, with its breathtaking landscape as well as some inland areas that are the extension of the submarine morphology, characterized by ridges, peaks, deep incisions and bizarre forms of erosion on meta-sandstone and metasiltstone, granites and orthogneiss. acknowledgements work conducted within the framework of the research project for setting up an experimental laboratory for the geoenvironmental analysis and monitoring of the malfatano coastal belt, by the environmental geology and thermographic laboratory at the department of earth sciences, university of cagliari (responsible scientist. prof. f. di gregorio) on behalf of forma urbis s.p.a. and national research project “i geomorfositi nel paesaggio italiano”, national co-ordinator prof. sandra piacente). references barca s. & di gregorio f. (1991a) proposta metodologica per il rilevamento dei monumenti geologici e geomorfologici bollettino dell'a.i.c., n. 83, pp. 25-31. barca s. & di gregorio f. (1991b) conservation et valorisation du patrimoine geologique de la sardaigne: une proposition metodologique 1er symphosium international sur la protetion du patrimoine geologique, digne les bains, france 10-16 giugno 1991, pp. 1-19. barca s., di gregorio f. & cannillo c. (1992) rilevamento e valutazione dei monumenti geologici e geomorfologici del meilogu-logudoro (sardegna nw) boll. aic, n. 86, 1 carta, 1 all., 1 fig., 1 tab.. barca s., di gregorio f., floris c. & montis m. (1996) rilevamento e valutazione dei monumenti e delle aree di rilevante interesse geologico e geomorfologico nei monti del sulcis (sardegna so). deputazione di storia patria per la sardegna – in: studi di geografia e storia in onore di angela terrosu asole, cagliari, pp. 189-335. barca s. & di gregorio f. (1999) paesaggi e monumenti geologici della provincia di cagliari saredit editore, cagliari, 417 pp. bertacchini, coratza & piacente s. (2002a) i beni geologici come espressione e veicolo culturale per tutti un progetto in emilia romagna geologia dell’ambiente, n. speciale “i geositi” anno x, n. 2/2002, 18-21 pp. bertacchini, coratza & piacente s. (2002b) an experimental data sheet for the inventory of geomorphosites proposed by cofin 2001 research group ”geosites in the italian landscape research, assessment and improvement” proceedings, workshop “geomorphological sites: research, assessment and improvement”, poster session, modena 19-22 giugno 2002, pp. 36. bertacchini m., giusti c., marchetti, m., panizza m. & pellegrini m. (1999) i beni geologici della provincia di modena università degli studi di modena e reggio emilia, dipartimento di scienze della terra, provincia di modena, assessorato difesa del suolo e tutela dell'ambiente, artioli editore, modena. brancucci g. & d’andrea m. (2002) national project:“protection of the italian geological heritage”. the test form for the geosites inventory. proceedings, workshop “geomorphological sites: research, assessment and improvement” (modena, 19-22 giugno 2002), pp. 42-43. boni m. & cocozza t. (1978) depositi mineralizzati di canale di marea nella formazione di gonnesa del cambrico inferiore della sardegna giorn. di geol.: 43, pp. 1-20. carannante g., cocozza t. & d'argenio b. (1984) late precambrian-cambrian geodynamic setting and tectono-sedimentary evolution of sardinia (italy). boll. soc. geol. it.: 103, pp. 121-128. carmignani l., carosi r., di pisa a., gattiglio m., musumeci g., oggiano g. & pertusati p.c. (1994) the hercynian chain in sardinia (italy) geodinamica acta, 7, pp. 31-47. carmignani l., cocozza t., ghezzo c., pertusati p.c. & ricci c.a. (1987) structural model of the hercynian basement of sardinia stabilimento l. salomone, roma. carosi r., perillo m., pertusati p.c. & gattiglio m. (1995) risultati preliminari dello studio strutturale del complesso del sulcis meridionale (sardegna sw) atti soc. tosc. sci. nat., mem., ser. a: 102, pp. 105-116. carton a. & de luigi e. (1980) itinerari naturalistici e geografici attraverso le montagne italiane 264 c. cannillo et al. trentino, c.a.i., arti grafiche tamari, bologna. carton a. coratza p. & marchetti m. (2003) methodological proposal for mapping geomorphosites geomorphological sites: assessment and mapping – workshop proceedings, cagliari (italy), 1-5-october 2003. casto l. & zarlenga f. (1992) i beni culturali a carattere geologico nella media valle del tevere enea, dipartimento ambiente – regione lazio, assessorato alle politiche per la promozione della cultura, dello spettacolo, del turismo e dello sport, centro regionale documentazione, pp. 1165. cocozza t. (1979) the cambrian of sardinia mém. soc. géol. it.: 20, pp.163-187. cocozza t., conti l., cozzupoli d., lombardi g., scharbert s. & traversa g. (1977) rb/sr age and geopetrologic evolution of crystall ine rocks in southern sulcis (sardinia) n. jb. geol. paläont. mh.: 1977, pp. 95-102. cocozza t. & gandin a. (1990) carbonate deposition during early rifting: the cambrian of sardinia and the triassic-jurassic of tuscany, italy spec. publs. int. ass. sediment.: 9, pp. 9-37. d’andrea m. (2001) servizio geologico nazionale: progetto “conservazione del patrimonio geologico italiano”. nota informativa giornale di geologia, se. iii, vol. 62, suppl., pp.121-124. delaperrière e. & lancelot j. (1989) datation u-pb sur zircons de l'orthogneiss du capo spartivento (sardaigne, italie), nouveau témoin d'un magmatisme alcalin ordovicien dans le sud de l'europe c. r. acad. sci. paris: 309, pp. 835-842. de waele j., di gregorio f. & piras g. (1998) geosites inventory in the paleozoic karst region of sulcisiglesiente (south-west sardinia, italy) international congress progeo ‘98, 7-13 june 1998, belogradchik, bulgaria. in geologica balcanica 28 (3-4), pp. 173-179. di gregorio f. & ulzega g. (2002) the state of the knowledge in the conservation and the valorization of geomorphological sites in sardinia proceedings, workshop “geomorphological sites: research, assessment and improvement”, poster session, modena 19-22giugno 2002, pp. 57-58. gandin a. (1987) depositional and paleogeographic evolution of the cambrian in south-west sardinia i.g.c.p. no. 5 newsletter: 7, pp. 151-165. gandin a., minzoni n. & courjault-radé p. (1987) shelf to basin transition in the cambrian-lower ordovician of sardinia (italy) geol. rundsch.: 76, pp. 827-836. gandin a., padalino g. & violo m. (1974) correlation between sedimentation and ore prospecting. sedimentological and ore-genesis studies of cambrian "arenarie" and "dolomia rigata" formations (sardinia, italy): deposition and concentration of barite in a evaporitic environment rend. soc. it. min. petr.: 30, pp. 251-303. gandin a. & pillola g.l. (1985) biostratigrafia e sedimentologia della formazione di cabitza nell'iglesiente. "evoluzione stratigrafica, tettonica, metamorfica e magmatica del paleozoico italiano" riunione scientifica, siena 13-14 dicembre, pp. 30-31. gisotti g. & massoli-novelli r. (1997) i geotopi nella pianificazione territoriale atti ix congr. ordine nazionale geologi, roma, aprile 1997, pp. 307311. junker b. & schneider h.h. (1979) l'infracambriano della sardegna sud-occidentale mém. soc. géol. it.: 20, 461 pp. junker b. & schneider h.h. (1983) the infracambrian bithia formation its facies development in southwest sardinia n. jb. geol. paläont. mh.: 24, pp. 369-384. ludwig k.r. & turi b. (1989) paleozoic age of capo spartivento orthogneiss, sardinia -chemical geology: 79, pp. 147-153. maciocco g. (1988) elementi di metodo operativo per la costruzione di una geografia di valori ambientali. una applicazione alla sardegna nord-occidentale in: atti del colloquio internazionale “metodi di valutazione nella pianificazione urbana e territoriale. teoria e casi di studio, capri – napoli, pp.135 147. massoli-novelli r. (2001) inventari di geositi in italia: stato dell’arte geologia dell’ambiente, 1, sigea, roma, pp.10-13. minzoni n. (1981) il precambriano del sulcis meridionale (sardegna) mineralogica et petrographica acta: 24, pp. 51-56. palmerini v. & palmerini sitzia r. (1978) le facies pelitiche della formazione di nebida (cambriano inf. sardo) boll. soc. geol. it.: 97, pp. 7-71. panizza m. & piacente s. (2002) geositi nel paesaggio italiano: ricerca, valutazione e valorizzazione. un progetto di ricerca per una nuova cultura geologica geologia dell’ambiente, vol. 2/2002, pp.3-4. pittau demelia p. & del rio m. (1982) acritarchi e loro significato stratigrafico nelle successioni paleozoiche della sardegna in: l. carmignani, t. cocozza, c. ghezzo, p.c. pertusati & c.a. ricci (eds.), guida alla geologia del paleozoico sardo. guide geologiche regionali, società geologica italiana: pp. 33-35. poli g. (eds.) 1999 geositi, testimoni del tempo. regione emilia-romagna, bologna, p.259. poli g. & bini m. (2002) geositi un laboratorio di comunicazione e valorizzazione. in: atti del convegno “la geologia ambientale: strategie per il nuovo millennio”, genova 27 – 29 giugno 2002. rasetti f. (1972) cambrian trilobite faunas of sardinia atti acc. naz. lincei, mem. cl. sc. fis. mat. e nat.: 11, pp. 1-100. sassi f.p. (1990) caratterizzazione petrografica delle formazioni di nebida e di bithia nel sulcis, con particolare riguardo alla fascia limite ente minerario sardo, relazione inedita, cagliari, 38 pp. sassi f.p., mazzoli c., sassi r. & visonà d. (1990) the capo spartivento-m. filau puzzle and structure of sw sardinia plinius: 3, milano. sassi f.p. & visonà d. (1989) gli gneiss di monte filau ed i loro rapporti con le rocce circostanti progemisa s.p.a. (relazione inedita), cagliari, 38 pp. tucci p. (1983) le metamorfiti dinamometamorfiche di capo malfatano (sulcis, sardegna) period. min.: 52, pp. 149-176. 265map of the geological ... ulzega a. (1995) geomorphology and stratigraphy of late quaternary in: a. cherchi (ed.), 6th paleobenthos international symposium, guidebook, cagliari, october 25-31, rend. sem. fac. sc. univ. cagliari (suppl. vol. 65, 1995): pp. 11-24. ulzega a. & ozer a. (1982) comptes-rendus de l'excursion-table ronde sur le tyrrhénien de sardaigne inqua: pp. 1-87. vai g.b. (1982) fasi di "rifting", nuovi dati stratigrafici e conseguenze paleogeografiche nel paleozoico inferiore in: l. carmignani, t. cocozza, c. ghezzo, p.c. pertusati & c.a. ricci (eds.), guida alla geologia del paleozoico sardo, società geologica italiana, guide geologiche regionali, pp. 93-195. vardabasso s. (1956) il quaternario della sardegna atti iv congr. int. quaternario, roma-pisa 1953, pp. 995-1018. zarlenga f. (1996) i geotopi, dalla ricerca scientifica alla pianificazione, controllo e gestione geologia dell’ambiente, vol. 4,2, pp. 3-6. 266 c. cannillo et al. sess 0_retro e indice edi.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 holocene environmental changes reconstructed in two archaeological sites in calabria (southern italy): a pedological and anthracological perspective teresa pelle 1, fabio scarciglia 1, emilia allevato 2, gaetano di pasquale 2, mauro f. la russa 1, domenico marino 3, elena natali 4, gaetano robustelli 1 & vincenzo tinè 4 1dipartimento di scienze della terra, università della calabria, arcavacata di rende (cs) 2laboratorio di storia della vegetazione e anatomia del legno, università di napoli “federico ii”, dipartimento di arboricoltura, botanica e patologia vegetale, portici (na) 3soprintendenza per i beni archeologici della calabria, ufficio territoriale della sila, crotone 4soprintendenza speciale al museo nazionale preistorico etnografico “l. pigorini”, roma corresponding author: t. pelle <teresa.pelle@unical.it> abstract: pelle t. et al., holocene environmental changes reconstructed in two archaeological sites in calabria (southern italy): a pedological and anthracological perspective. (it issn 0394-3356, 2011) a reconstruction of holocene climatic and environmental changes in two archaeological sites of sw and n-central calabria (southern italy) is proposed in this paper, based on a comparison of geoarchaeological, pedological and pedoanthracological data from soil profiles in the coastal hilly and inland mountainous surroundings of palmi and cecita lake, respectively. riassunto: pelle t. et al., ricostruzione dei cambiamenti ambientali olocenici in due siti archeologici della calabria (italia meridionale): una prospettiva pedologica ed antracologica. (it issn 0394-3356, 2011) in questo lavoro viene proposta una ricostruzione delle variazioni climatiche ed ambientali avvenute nel corso dell’olocene in due siti archeologici della calabria sud-occidentale e centro-settentrionale (italia meridionale). essa si basa sul confronto di dati geoarcheologici, pedologici e pedoantracologici relativi ad alcuni profili di suolo nelle vicinanze di palmi e del lago cecita, rispettivamente in un’area collinare costiera e montana interna. key words: soil features; pedoanthracology; holocene climatic changes; human impact; deforestation parole chiave: caratteri pedologici; pedoantracologia; cambiamenti climatici olocenici; impatto antropico; deforestazione the study of holocene paleoclimate and paleoenvironments represents a topical issue in the recent scientific literature, because of its time immediacy and connection with modern climatic changes. great interest is focused on exploring cause-effect relationships between climate modifications and cultural dynamics across this period, as well as on estimating their mutual role in changing environments. this paper deals with the reconstruction of climatic and environmental changes recorded in some holocene soil profiles from two archaeological sites in calabria (southern italy). they were excavated in the surroundings of palmi and cecita lake, located in southwestern coastal and northcentral inland calabria, respectively. an integrated archaeological, pedostratigraphic and paleobotanical (pedoanthracological) approach was applied. in particular, archaeological finds and settlements of different epochs provide useful chronological constraints; mineralogical, physical, chemical, macro and micromorphological soil features are used as proxies of climatic conditions and man’s activities; macroscopic soil charcoal content derived from in situ natural or anthropogenic fires represents a reliable detailed indicator (complementary to traditional pollen-based methods) of diachronic vegetation changes on a local scale (e.g. di pasquale et al., 2007). the excavation close to palmi (piani della corona site) is located on a wide terrace at about 500 m a.s.l., along the southern tyrrhenian coast of calabria, characterized by a typical stair-like sequence of pleistocene marine terraces (e.g. tortorici et al., 2003). it exposed a pedostratigraphic succession partly described by bernasconi et al. (2010). deep argillic (btb) horizons with variable amounts of clay coatings stacked within pores include late neolithic settlements and artifacts (about 6500-5800 years bp). they are partly truncated and buried by anthropogenically disturbed surface organic-mineral (ap) horizons, that display repeated ploughing traces of undifferentiated historical epochs, separated by a late early bronze age paleosurface (about 4000-3700 years bp). this surface is in turn affected by marks of archaeological structures, ploughing and various excavations, often filled with organic-rich soil material derived from overlying a horizons. the archaeological soils from cecita, a nowadays 197 199 198 artificial lake which occupies a paleo-lake depression in the sila massif upland (e.g. scarciglia et al., 2005, 2008), occur on fluvio-lacustrine terraces at about 1130-1140 m a.s.l. their main features are described by pelle et al. (2010). they span from late neolithic/early eneolithic (about 58005350 years bp) to greek (6th to 3rd century bc) and roman times (3rd century bc – 6th century ad). we focused on late prehistoric and roman soils, because at present the greek site is submerged about 6 m below lake level. they all consist of surface a horizons, in places affected by repeated prehistoric to modern ploughing traces (ap). these organic-mineral horizons may include very scarce clay coatings in pores, which become more abundant in the neolithic soil, where the a horizon overlies a bw horizon. above soils from both sites partly developed on volcanic ash and display variable andisol-like features (iuss working group wrb, 2006; soil survey staff, 2010) related to formation of some amounts of short-range order minerals. volcanic parent material mainly consists of very small pumices with rhyolitic composition, identified and analyzed at the microscale using sem-eds. their composition, the pedostratigrahic position and some radiometric dates suggest a provenance from late pleistocene/holocene explosive eruptions of the aeolian islands (scarciglia et al., 2008; bernasconi et al., 2010), about 80 to 170 km far to the southwest (from palmi and cecita lake, respectively). micromorphological observations performed in thin sections prepared from undisturbed soil samples, highlighted the occurrence of clay coatings in the neolithic layers of both sites, and their relict (present-day inactive) significance (cf. catt, 1989), testified by smooth-banded to grainy extinction pattern in crossed polarized light and fragmentation (e.g. fitzpatrick, 1984; kemp, 1998). these features, coupled with the dominance of phyllosilicate clays identified by x-ray diffraction analysis (xrd) and fourier transformed infrared spectroscopy (ftir) in the same horizons, suggest climatic conditions characterized by high moisture availability and some seasonal contrast, enhanced by a warm-humid climate. therefore, main soil development may have occurred during the late earlymiddle holocene climatic optimum (scarciglia et al., 2005, 2008; bernasconi et al., 2010; pelle et al., 2010). the post-neolithic soil horizons (roman age at cecita and undetermined at palmi) show more abundant short-range order minerals than phyllosilicates (xrd, ftir and geochemical parameters) and no to very rare clay coatings, that suggest climatic changes towards overall prolonged humid (and probably cooler) conditions. the lack of a distinct and continuous chronological record for the post-neolithic soil horizons from palmi and cecita dos not permit a detailed reconstruction and interpretation of late holocene climatic changes and their extent in these sites. however, above humid/cool conditions during the late holocene could be related to repeated phases of higher lake levels documented from middle europe to central italy around 2700-2500, ~1800 and 1300 -1000 years bp (magny, 2004; giraudi, 2007). moreover, between the distinct climatic phases identified during and after the neolithic, a severe land degradation is recorded. it is testified by human impact (deforestation, cultivation and other activities) and soil erosion. pedoanthracological data from cecita give good evidence of it. in fact, charcoal fragments from neolithic soils are dominated by deciduous oak-forest (mainly quercus deciduous type), whereas a transition to a mountain pine forest dominated by pinus sylvestris group (probably pinus laricio) is recorded in the roman soils. preliminary soil charcoal data from palmi suggest a stability of a deciduous forest cover dominated by oaks. in fact, this taxon is present both in the neolithic and in the post-bronze age horizons. finally it is noteworthy the presence of abies alba, belonging today only to mountain vegetation, identified in a neolithic horizon. both the data concerning the silver fir and post-bronze oaks need to be dated with ams technique. it cannot be ruled out that also some effects of climate drying (one or more episodes known in the literature; e.g. sauro et al., 2003; mayewski, 2004; di donato et al., 2008; di rita & magri, 2009) could have enhanced land degradation after the neolithic climatic optimum. neither the hilly coastal site of palmi nor the inland mountainous one of cecita lake seem to register clear evidence of it, although diminished to absent clay illuviation in younger soil horizons could be also related to such climatic changes. references bernasconi m.p., chiocci f.l., critelli s., la russa m.f., marozzo s., martorelli e., natali e., pelle t., robustelli g., russo ermolli e., scarciglia f. & tinè v. (2010) multi-proxy reconstruction of late pleistocene to holocene paleoenvironmental changes in sw calabria (southern italy) from marine and continental records. il quaternario –it. j. quat. sci., 23(2), 249-256. catt j.a. (1989) relict properties in soils of the central and north-west european temperate region. catena suppl., 16, 41-58. di donato v., esposito p., russo ermolli e., cheddadi r. & scarano a. (2008) coupled atmospheric and marine palaeoclimatic reconstruction for the last 35 kyr in the sele plain–gulf of salerno area (southern italy). quat. int., 190, 146-157. di pasquale g., marziano m., impagliazzo s., lubritto c., de natale a. & bader m.y. (2008) the holocene treeline in the northern andes (ecuador): first evit. pelle et al. 199 ms. received: testo ricevuto il dence from soil charcoal. palaeogeogr. palaeoclimatol. palaeoecol., 259(1), 17-34. di rita f. & magri d. (2009) holocene drought, deforestation and evergreen vegetation development in the central mediterranean: a 5500 year record from lago alimini piccolo, apulia, southeast italy. holocene, 19 (2), 295-306. fitzpatrick e.a. (1984) micromorphology of soils. chapman and hall, london, 433 pp. giraudi c. (2007) le variazioni climatiche in italia centrale negli ultimi 10.000 anni. in: wezel f. (ed.) variabilità naturale del clima nell’olocene ed in tempi storici: un approccio geologico. quad. soc. geol., 1, 18-24. iuss working group wrb (2006) world reference base for soil resources 2006 – a framework for international classification, correlation and communication. world soil resources report, 103, fao, rome, 132 pp. kemp r.a. (1998) role of micromorphology in paleopedological research. quat. int., 51-52, 133-141. magny m. (2004) holocene climate variability as reflected by mid-european lake-level fluctuations and its probable impact on prehistoric human settlements. quat. int., 113, 65-79. mayewski p.a., rholing e.e., stager j.c., karlén w., maasch k.a., meeker l.d., meyerson e.a., gasse f., van kreveld s., holmgren k., lee-thorp j., rosqvist g., rack f., staubwasser m., schneider r.r. & steig e.j. (2004) holocene climate variability. quat. res., 62, 243-255. pelle t., scarciglia f., robustelli g., allevato e., di pasquale g., mitro r. & marino d. (2010) multidisciplinary study of holocene soils in the archaeological sites of cecita lake (sila massif, calabria, italy): paleoenvironmental reconstruction. atti del convegno “scienze naturali e archeologia. il paesaggio antico: interazione uomo/ambiente ed eventi catastrofici”, napoli, 14-16 ottobre 2010, aracne, roma, 183-187. sauro u., borsato a., frisia s., madonia g., piccini l., tuccimei p., camuffo d., cucchi f., forti p., macaluso t., miorandi r., paladini m., salzano r., shopov y., spötl c., stoykova d. & zini l. (2003) variabilità climatica nel tardiglaciale e nell’olocene da dati di speleotemi lungo una traversa n-s in italia. studi trent. sci. nat., acta geol., 80, 175-184. scarciglia f., le pera e., vecchio g. & critelli s. (2005) the interplay of geomorphic processes and soil development in an upland environment, calabria, south italy. geomorphology, 69(1-4), 169-190. scarciglia f., de rosa r., vecchio g., apollaro c., robustelli g. & terrasi f. (2008) volcanic soil formation in calabria (southern italy): the cecita lake geosol in the late quaternary geomorphological evolution of the sila uplands. j. volc. geoth. res., 177 (1), 101-117. soil survey staff (2010) keys to soil taxonomy. 11th edit., usda-natural resources conservation service, washington dc, 338 pp. tortorici g., bianca m., de guidi g., monaco c. & tortorici l. (2003) fault activity and marine terracing in the capo vaticano area (southern calabria) during the middle-late quaternary. quat. int., 101102, 269-278. january 14, 2011 14 gennaio 2011 holocene environmental changes reconstructed in two ... available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 37 (2), 2024, 103-112 romagna (bertolani marchetti et al., 1988; rottoli, 1997; cremaschi et al., 2006; mercuri et al., 2006), near rome (gran carro di bolsena: fundurulic et al., 2022) and near napoli (longone-poggiomarino: livadie et al., 2010). about the end of some of these pile-dwelling settlements, cultural and climatic factors (or induced by climatic factors) have been argued (e.g., jennings, 2014; hitchcock & maeir, 2016). our research, providing a detailed palaeogeographic reconstruction of the area around the pile-dwellings found near stagno, gives us a view of the ancient landscape and its evolution that could shed light on the causes of the abandonment of the stagno site, which have not been clarified in previous studies (giachi et al., 2010 cum biblio). 2. study area from a geological point of view, the study area is located within the viareggio basin (mariani & prato, 1988; pascucci, 2005). this basin of tectonic origin is located in the inner part of the northern apennine; it originated during the late miocene after an extensional tectonic phase linked to the apennines orogeny (carmignani et al., 2001). according to classic geodynamic models, this basin and the others nearby are bounded by north-west-south-east-trending normal faults and east-west-aligned transform faults (mariani & prato, 1988; pascucci, 2005). since the late miocene, https://doi.org/10.26382/amq.2024.06 1. introduction in 1993, remains of a pile-dwelling settlement were found at stagno (collesalvetti), near livorno, in tuscany (zanini, 1997; fig. 1). following gambogi et al. (1995) and giachi et al. (2010), the ceramic and metal materials found in association with wooden structures, date the archaeological site of stagno back to the late bronze age-early iron age transition. more precisely, zanini & martinelli (2005) radiometrically dated some samples from wooden poles to an age between cal 1116 ±5 and cal 1091 ±15 yr bc. excavations and archaeobotanical studies assess that these human settlements based their livelihoods essentially on the gathering of wild fruits and nuts, and the cultivation of cereals and pulse (giachi et al., 2010). analyses of plant remains show the presence of temporary freshwater pools and of a lowland forest in the surroundings (mariotti lippi & mori secci, 2007). this archaeological site, which is presumed to have been built in a lagoon environment (zanini, 1997), is an important find that has provided, and can provide, meaningful data about the central italy pile-dwelling settlements of the late bronze -early iron age. in fact, up to now very few pile-dwelling sites have been investigated in central italy. actually, pile-dwelling settlements of the bronze age are only present in trentino (see: perini, 1984), lombardia (see: de marinis et al., 2005; valsecchi et al., 2006), emiliapaleoenvironmental reconstruction of the prehistoric pile-dwelling settlement of stagno (livorno, italy) based on molluscan assemblages rita catanzariti 1 , luciano cauli 2 , alessandro ciampalini 2 , simone da prato 1 , franco sammartino 2 1 cnr-igg, pisa, italy. 2 gruppo archeologico paleontologico livornese del museo di storia naturale del mediterraneo, livorno, italy. corresponding author: rita catanzariti <rita.catanzariti@igg.cnr.it> abstract: aim of this study is to improve the knowledge about the palaeoenvironment of a prehistoric pile-dwelling settlement that was discovered near stagno (collesalvetti, livorno) in 1993. calibrated radiocarbon dates on materials from the wooden poles of the pile-dwellings have dated the site to an interval of time from the late bronze age to the early iron age (cal 1116-1091 ±15 yr bc). the palaeoenvironment of the area has been reconstructed studying the molluscan assemblages found in the fossiliferous levels recovered during the archaeological excavations. the palaeogeography of the zone around the site was also reconstructed using data from previews stratigraphic studies performed on the nearby areas. the molluscs occurring in the archeological site are represented by 9 taxa: 6 taxa belonging to bivalves and 3 to gastropods. the associations correspond to fossil communities that are characteristic of lagoon muddy-clayey bottoms. we hypothesise that all the data considered allow a palaeogeographic reconstruction of the area providing different environments represented by alternating land and submerged areas. this reconstruction can be also useful to shed light on the causes of the abandonment of the pile-dwelling site. keywords: molluscs; tuscany; late bronze age-early iron age; palaeoenvironment; palaeogeography the viareggio basin was filled by marine, transitional and continental sediments, which show a continuous alternation of transgressive and regressive marine phases, mainly linked to the glacio-eustatic control (bossio et al., 1993). in addition, recent researches on the subsurface of the pisa plain, in the southern part of the viareggio basin, have defined with detail the depositional architecture of the late quaternary succession (amorosi et al., 2008; sarti et al., 2015). according to these researches, during the last glacial maximum, the strong erosive power of the rivers flowing across the basin determined the formation of a palaeovalley system, subsequently filled by sediments linked to the holocene transgression (sarti et al., 2015; rossi et al., 2017). moreover, continental and transitional environments occurred during the holocene, as reported in kaniewski et al. (2018). according to the geological map, the stagno archaeological site is entirely included in an area where holocene continental sediments outcrop, while the reliefs located to the south, are characterised by exposed pliocene marine sediments and late-middle pleistocene continental deposits (fig. 1). 3. material and methods for the study of the archaeological site, 22 boreholes were realised in the area of the archaeological findings during the 1993 fieldworks, on which giachi et al. (2010) identified some archaeological units (su) based on lithology and plant remains. starting from the stratigraphy of 3 boreholes (ss1, ss2 and ss3, fig. 2), which were available to us, and from the stratigraphy of the site, we identified eight stratigraphic layers (l1 to l8) on the lithological characteristics and archaeological content of the sediments, and linked them to the stratigraphic units reported in giachi et al. (2010) (fig. 3, tab. 1). the molluscs occurring in the archaeological units su110, su160 and su116, were identified after standard cleaning procedures. the sediments were washed through a 0.84 mm sieve and then dried in oven at 110°c. the identified molluscs are currently deposited at the museo di storia naturale del mediterraneo of livorno and at the soprintendenza archeologica della toscana, now soprintendenza archeologia, belle arti e paesaggio per le province di pisa e livorno (sabap) located in pisa. the molluscs systematic and nomenclature follow sabelli et al. (1990) and the world register of marine species (worms, 2023). 4. results 4.1. stratigraphy of the archaeological area a schematic description of the stratigraphy of the cores ss1, ss2 and ss3 is reported in figure 2. the 8 stratigraphic lithofacies (layers), to which the archaeological units containing shell remains were linked (fig. 3, tab. 1) are briefly described below. from the bottom: l8: dark grey silty clay with local peat. l7: silty clay with plastic consistency, containing shell remains; centimeter levels of sand occur in places. l6: grey silty clay, 0.15 m thick. l5: blackish clay 0.15 m thick, with shell remains. l4: greenish grey silty clay with sandy levels, 0.40 m thick. l3: moderately compacted brown-grey silty clay, 1.30 m thick. l2: light brown silty clay about 0.90 m thick, slightly sandy in places. l1: heterogeneous sediments, corresponding to a layer of soil about 0.6 m thick. some of these stratigraphic layers contained the 104 catanzariti r. et al. fig. 1 geological map of the study area around the stagno pile-dwelling site, modified from the geological continuum of tuscany region (http://www502.regione.toscana.it/geoscopio/cartoteca.html). archaeological units with shells identified by giachi et al. (2010). unit su110, which consists of grey clay with decaying wooden elements and shell remains, corresponds to the l7 stratigraphic layer. this unit contains very frequent cerastoderma edule, cerastoderma glaucum, loripes orbiculatus and peringia ulvae, frequent macomangulus tenuis and bittium reticulatum, rare glycymeris nummaria, mytilaster minimus and rissoa membranacea. unit su160 corresponds to the l5 stratigraphic layer and unit su116 corresponds to the l3. both these units consist of grey clay with molluscs. su160 contains very frequent cerastoderma edule, cerastoderma glaucum, loripes orbiculatus and peringia ulvae, frequent macomangulus tenuis, rare glycymeris nummaria, mytilaster minimus, bittium reticulatum and rissoa membranacea. su116 contains very frequent cerastoderma edule, cerastoderma glaucum, loripes orbiculatus, frequent peringia ulvae, rare mytilaster minimus and bittium reticulatum. 4.2. remarks on the molluscs found in the archaeological site the molluscs recovered from the archaeological units (su110, su160 and su116; tab. 1; fig. 3) of the stagno archaeological site are represented by 6 species of bivalves (glycymeris nummaria, mytilaster minimus, loripes orbiculatus, cerastoderma edule, cerastoderma glaucum, macomangulus tenuis) and 3 species of gastropods (rissoa membranacea, peringia ulvae, bittium reticulatum). preservation of fossils is generally good, the protoconch of gastropods has a sculpture nearly always intact, and some specimens of the bivalves cerastoderma glaucum and loripes orbiculatus have articulated valves. in addition, the species cerastoderma glaucum, loripes orbiculatus and peringia ulvae occur with different stages of growth. the good preservation of great part of shells and the occurrence of articulated valves with different stages of growth, prove that the mollusc with these features were autochthonous. pictures of selected species are represented in figure 4, while table 2 shows the distribution of molluscs within each archaeological unit 4.3. class bivalves 1) glycymeris nummaria (linneus, 1758) can be found in infralittoral areas, at depths that range between 2 and 40 m in muddy sands and well-sorted fine sands (peres & picard, 1964; martins et al., 2014; crnčević et al., 2013). this species is also reported in low salinity littoral environments, near river mouths (vatova, 1949). the species rarely occurs, and some specimens found in su160 show evidence of manufacturing and exploitation traces. it is possible that the glycymeris nummaria valve with an irregular hole in the umbo area, shown in figure 4, could be a shell ornament as those found in other archaeological sites of the bronze age (poggiani, 2017). 2) mytilaster minimus (poli, 1795) is a euryhaline and eurythermic species typical of lagoonal systems that lives on soft bottom (i.e., nicolaidou et al., 2006). this species was found in all samples, but in low abundance (tab. 2). 3) loripes orbiculatus (poli, 1795). ragaini & mari 105 the molluscan assemblages of stagno (livorno, italy) f ig . 2 s tr a ti g ra p h ic c o lu m n s o f th e c o re s f ro m t h e a rc h a e o lo g ic a l a re a . 106 fig. 3 composite stratigraphy of the stagno pile-dwelling site (from the area c of giachi et al., 2010), with stratigraphic layers (l) and archaeological units (su sensu giachi et al., 2010). tab. 1 sequence of the stratigraphic layers and the main archaeological units recognised in the stagno pile-dwelling site. in bold the archaeological units sampled. catanzariti r. et al. 1950). in the analysed samples the species is rare (tab. 2). 2) peringia ulvae (pennant, 1777). this species usually lives on muddy sand bottoms, in transitional low salinity environments such as eustuaries, lagoons and marshes. samples from stagno site contain frequent forms of the species (tab. 2). 3) bittium reticulatum (da costa, 1778). this species is commonly recorded on sandy muddy bottoms in lagoons and coastal shallow waters (fersi et al., 2023 ani (1992) include this species in the biocenosis of muddy sands, especially in zones influenced by fresh water. this species is reported in the mediterranean and atlantic intertidal grassland ecosystems, including the bay of arcachon, where water salinity ranges between 25 and 35 ppt (mosbahi et al., 2017). all samples contain very frequent specimens of this species (tab. 2). 4) cerastoderma edule (linneus, 1758). it is one of the more common bivalve species, which is used as food source. this extremely polymorphous species is euryhaline and eurythermic and lives in the sandy or sandy-muddy bottoms (dabouineau & ponsero, 2009; el asri et al., 2022). it was resulted to be very frequent in the analysed samples (tab. 2). 5) cerastoderma glaucum (bruguière, 1789). this species is reported to thrive in microtidal lagoons, shallow creeks, ponds, and salt marshes, or more rarely on lower shores in estuaries (sromek et al., 2019). also this species resulted to be very frequent (tab. 2). 6) macomangulus tenuis (da costa, 1778). this species is found in fine sands from middle shore to shallow sublittoral zone (picard, 1965). it was found both in fragments and as rare unbroken specimens in the us110 and us 116 (tab. 2). 4.4. class gastropods 1) rissoa membranacea (adams, 1800). like many species of rissoa it has a lagoon habitat and among them it has a higher degree of eurihalinity (mars, 107 fig. 4 photographs of selected species of molluscs from the archaeological units su116-su160-su110. a) cerastoderma edule (linnaeus, 1758), length 6 mm, repository code n. 827, external view; 1a, internal view. b) cerastoderma glaucum (linnaeus, 1758), length 17 mm, repository code n. 827, external view; 1b, internal view. c) bittium reticulatum (da costa, 1778), height 4 mm, repository code n. 826. d) cerastoderma glaucum (bruguière, 1789), length 20 mm, repository code n. 828, external view; 1d, internal view. e) glycymeris nummaria (linnaeus, 1758), length 45 mm, repository code n. 830, external view; 1e, internal view. tab. 2 distribution of the molluscs found in the archaeological units of the stagno pile-dwelling site. classes of abundance: r (rare = number of specimens between 1 and 10), f (frequent = number of specimens between 11 and 50), vf (very frequent = number of specimens > 50). the molluscan assemblages of stagno (livorno, italy) 108 cum bibliography) of the mediterranean sea. in our samples, it ranges from frequent to rare (tab. 2). 5. discussion the palaeontological analysis shows that, with the exception of glycymeris nummaria, mytilaster minimus and macomangulus tenuis, all the taxa found in the sampled archaeological units belong to the lagoon euryhaline and eurythermal biocenosis, both as exclusive opportunistic (c. edule, c. glaucum, p. ulvae), either as preferential (r. membranacea, b. reticulatum) or as accompanying species (loripes orbiculatus). the occurrence of autochthonous species related to the biocenosis of the infra-coastal environment in su110 and su160 suggests the existence of a connection between the lagoon and the nearby open sea, also supported by the presence of fish remains and posidonia oceanica debris in layers l7 and l5 (tab. 1). the large number of fragments of m. tenuis, found in the su110 and su160 units, probably due to exceptional high-energy events (sea coastal storms) would support the argument that during the pre-settlement and settlement phases (tab. 1) the pile-dwelling site was not far from the sea. on the other hand, the total absence of the marine species macomangulus tenuis and glycymeris nummaria in the more recent su116 seems to indicate that the lagoon was increasingly protected from the sea (more confined lagoon), so that it was not affected by the sea coastal high-energy events. therefore, molluscs and stratigraphic analyses indicate that lagoon conditions with a minor degree of isolation from the sea (less confined lagoon) remained unchanged in the stagno site from the pre-settlement phase (corresponding to su110) to the settlement phase (corresponding to su160). furthermore, lagoon conditions with a greater degree of isolation from the sea (more confined lagoon) is evident for the post-abandonment phase (su116, tab. 1). these indications allow us to hypothesise that the causes of the abandonment of the site was not closely linked to climatic or environmental changes, but maybe to cultural changes. probably, local conflicts and/or invasions could have induced inhabitants to refuge in larger settlements, far from the sea. actually, at the transition between the late bronze age and the early iron age, eastern but also western mediterranean coastal regions were impacted by the attacks of the so-called sea peoples (e.g., kaniewski et al., 2011; hitchcock & maeir, 2016). during this period, cities and states from greece through mesopotamia to egypt declined or collapsed in consequence of variable causes and literature provides evidence in support of the drought hypothesis as a triggering factor behind the late bronze age collapse (e.g., kaniewski et al., 2010 cum bibliography). the sea peoples invasion could probably have led to the disruption of the flourishing communities that inhabited the tuscan coast during the bronze age (grifoni cremonesi, 2006). as a consequence, or either alternatively, the cultural changes occurring in the final stages of the late bronze age and beginning of the iron age, led humans to break with traditions and change type of settlements, which corresponded better to new needs (jennings, 2014). our new data, and both the previous stratigraphic studies of boreholes and the findings from archaeological sites located near the stagno site, allow a better knowledge of the palaeogeography of a wide area, in the period between the late bronze age and the early iron age. we can compare the stratigraphy of the archaeological site with the stratigraphy performed by kaniewski et al. (2018), on a core drilled at santo stefano ai lupi (pp3, north of the stagno pile dwelling, fig. 1). the pp3 stratigraphy (fig. 5) suggests the presence fig. 5 tentatively correlation of the depositional facies recognized in the cores pp3 (modified from kaniewski et al. 2018), pp1 (modified from mazzini et al., 2017), and in the cores ss1 and ss3. radiometric data from 1 kaniewski et al. (2018), 2 mazzini et al., (2017), 3 zanini & martinelli (2005). catanzariti r. et al. emerged beach area, which stretched from the harbour area to the mouth of the lagoon, can be assumed through the evidence of human settlements, referable to the eneolithic age-early iron age interval of time, found at lago filippo (site 9, fig. 6; sammartino, 1986) and casa paretaio (site 10, fig. 6; sammartino, 1997). furthermore, southwards a large area of beach was present, as testified by the etruscan artefacts found at fortezza vecchia (site 11, fig. 6; gambogi & materrazzi, 1997). finally, the presence of a large system of beaches and dunes west of the lagoon, seems to be also supported by the study of a core drilled in the livorno harbour (e, fig. 6) that records beach deposits, up to 4530 ±60 yr bp, in the area of livorno (dall’antonia et al., 2004). as consequence, the lagoon area of stagno was constrained to the south by continental deposits and to the north by a delta system. 6. conclusions this contribution, through a palaeontological and stratigraphic approach, improves the knowledge of the environment where the prehistoric stagno archaeological site was built. the analysis of the molluscs found in the stratigraphic layers su110, su160 and su116, allowed us to confirm that the pile-dwelling settlement was of a delta plain system characterized by a high input of freshwater since 1950 ±45 bc. in particular, the same authors identify a phase of marine influence linked to a decreasing river flow at 1250 ±40 850 ±40 yr bc. in addition, the stratigraphy performed by mazzini et al. (2016) on the core pp1 (fig. 5) located between pp3 and the archaeological site (fig.1) records a delta depositional facies younger than 5275 ±60cal yr bp, probably comparable with that found in pp3. delta depositional facies is not present in the cores ss1 to ss3 (fig. 5), so confining the delta system to the north (fig. 6). north-west of the stagno pile-dwelling area, not far from poggio al lupo (sites 1-4, fig. 6), four sites have been identified with concentrations of coarse-grained ceramic materials, with smooth and notched cords, which refer to the bronze to iron age (panicucci & bagnoli, 1986) and allow us to confine the lagoon mouth of stagno. northwards the lagoon was constrained by the isola di coltano relieves as testified by the occurrence of remains of a village of the iron to etruscan age (1600-1200 bc; pasquinucci & menchelli, 1997; boschian et al., 2006; sites 5-7, fig. 6) that indicates emerged land. south of the stagno pile dwelling, ceramic materials related to the archaic etruscan interval of time were recently found at casone (site 8, fig. 6; sammartino, personal communication). the presence of a large 109 fig. 6 palaeogeographic reconstruction of the area around the stagno pile-dwelling site, during the late bronze age-early iron age (modified by dall’antonia & mazzanti, 2001 and mariotti lippi & mori secci, 2007). archaeological sites: 1-4) poggio al lupo (panicucci & bagnoli, 1986); 5-7) isola di coltano (pasquinucci & menchelli, 1997; boschian et al., 2006); 8) casone (sammartino, personal communication); 9) lago filippo (sammartino, 1986); 10) casa paretaio (sammartino, 1997); 11) fortezza vecchia (gambogi & materrazzi, 1997); core e (dall’antonia et al., 2004), core pp3 (kaniewski et al., 2018), core pp1 (mazzini et al., 2017). the molluscan assemblages of stagno (livorno, italy) martini i. (eds), anatomy of an orogen. kluwer academic publishers, 197-214. cremaschi m., pizzi c., valsecchi v. (2006) water management and land use in the terramare and a possible climatic co factor in their abandonment: the case study of the terramara of poviglio santa rosa (northern italy). quaternary international, 151, 87-98. doi: 10.1016/j.quaint.2006.01.020 dabouineau l., ponsero a. (2009) synthesis on biology of common european cockle cerastoderma edule. second edition université catholique de l’ouest réserve naturelle nationale baie de st brieuc, 23 pp. dall’antonia b., mazzanti r. (2001) geomorfologia e idrografia. tombolo: territorio della basilica di san piero a grado. ente parco regionale migliarino, s. rossore e massaciuccoli, pisa, 7-66. dall’antonia b., ciampalini a., michelucci l., zanchetta g., bossio a., bonadonna f. (2004) new insights on the quaternary stratigraphy of the livorno area as deduced by borehole investigations. bollettino della società paleontologica italiana, 43, 141-157. della rocca b., mazzanti r., pranzini e. (1987) studio geomorfologico della pianura di pisa. geografia fisica e dinamica del quaternario, 10, 56-84. de marinis r.c., rapi m., ravazzi c., arpenti e., deaddis m., perego r. (2005) lavagnone (desenzano del garda): new excavations and palaeoecology of a bronze age pile dwelling site in northern italy. in: della casa p., trashsel m. (eds), wetland economies and societies. proceeding of the international conference in zurich, 10-13 march 2004. collectio archaeologica, 3, 221 -232. el asri f., errhif a., tamsouri m-n., martin d., maanan m., zidane h. (2022) analysis of the structural characteristics and spatial organization of macrobenthic fauna in oualidia lagoon, morocco. applied water science, 12, 96. doi: 10.1007/s13201-022-01629-z fersi a., pezy j. , bakalem a., neifar l., dauvin j.c. (2023) molluscs from tidal channels of the gulf of gabès (tunisia): quantitative data and comparison with other lagoons and coastal waters of the mediterranean sea. journal of marine science and engineering, 11, 1-26. doi: 10.3390/jmse11030545 fundurulic a., valenti i., celant a., barbaro b., costa m., manhita a., severi e., barrocas dias c., magri d. (2022) cereal meals from the early iron age underwater settlement of “gran carro” (bolsena lake, central italy). sustainability, 14, 1-19. doi: 10.3390/su14073941 gambogi p., nanni m., zanini a. (1995) l’abitato protostorico di livorno stagno. nota preliminare. preistoria e protostoria in etruria, atti del secondo incontro di studi, 93-111. gambogi p., materrazzi s. (1997) livorno fortezza medicea, in zanini a. (a cura di), dal bronzo al ferro. il ii millennio a.c. nella toscana centro occidentale, pisa, 165-167. giachi g., mori secci m., gambogi p., mariotti lippi m. built in a lagoon environment close to the livorno hills. furthermore, the site was located in a strategic area, in a relatively closed lagoon near the sea, so that the marine resources could be guaranteed. because of its palaeoenvironmental characteristics, the stagno site is a singular example of a late bronze age-early iron age lagoon pile-dwelling settlement in italy. in addition, we were able to reconstruct the palaeogeography of the area between the livorno harbour and isola di coltano during the late bronze age-early iron age transition. uncertainties are still about the precise location of terrestrial and submerged areas; this gap of knowledge can only be filled by studies aimed at the reconstruction of the shoreline of the northern area of livorno based on radiometric datings, and geomorphological, sedimentological and stratigraphic studies. finally, the palaeontological and stratigraphic study seems to suggest that the abandonment of the pile-dwelling settlement was not strictly due to major environmental or climatic changes, but probably to historical and cultural reasons or a combining both, however associated to a general worsening of the economic and territorial organization of the societies of that time. acknowledgments this paper is dedicated to the memory of our friend and co-worker luciano cauli, who passed away while this paper was being written. his passion for the palaeontology has led to the realization of this study. we thank pamela gambogi and the soprintendenza archeologica della toscana for supporting and helping during the archaeological excavation. references amorosi a., sarti g., rossi v., fontana v. (2008) anatomy and sequence stratigraphy of the late quaternary arno valley fill (tuscany, italy). in: amorosi a., haq b.u., sabato l. (eds.), advances in application of sequence stratigraphy in italy. geologica acta, special publication, 1, 55-66. bertolani marchetti d., dallai d., trevisan grandi g. (1988) ricerche palinologiche sugli insediamenti preistorici e protostorici di tabina di magreta. in: cardarelli a. (ed), modena dalle origini all’anno mille.studi di archeologia e storia i. panini, modena, 229-232. boschian g., bossio a., dall’antonia b., mazzanti r. (2006) il quaternario della toscana costiera. studi costieri, 12, pp. 208. bossio a., costantini a., lazzarotto a., liotta d., mazzanti r., mazzei r., salvatorini g., sandrelli f. (1993) rassegna delle conoscenze sulla stratigrafia del neoautoctono toscano. memorie della società geologica italiana, 49, 17-98. crnčević m., peharda m., ezgeta balić d., pećarević m. (2013) reproductive cycle of glycymeris nummaria (mollusca: bivalvia) from mali ston bay, adriatic sea, croatia. scientia marina, 77, 293-300. doi: 10.3989/scimar.03722.10a carmignani l., decandia f.a., disperati l., fantozzi l., kligfield r., lazzarotto a., liotta d., meccheri m. (2001) inner northern apennines. in: vai g.b. & 110 catanzariti r. et al. ing of human history. the micropalaeontological society, special publications. geological society, london, 121-142. mercuri a.m., accorsi c.a., bandini mazzanti m., bosi g., cardarelli a., labate d., marchesini m., trevisan grandi g. (2006) economy and environment of bronze age settlements terramaras on the po plain (northern italy): first results from the archaeobotanical research at the terramara di montale. vegetation history and archaeobotany, 1, 43-60. doi: 10.1007/s00334-006-0034-1 mosbahi n., blanchet h., lavesque n., de montaudouin x., dauvin j.c., neifar l. (2017) main ecological features of benthic macrofauna in mediterranean and atlantic intertidal eelgrass beds: a comparative study. journal of marine biology & oceanography, 6, 1-12. nicolaidou a., petrou k., kormas k.a., reizopoulou s. (2006) inter annual variability of soft bottom macrofaunal communities in two ionian sea lagoons. hidrobiology, 555, 89-98. doi: 10.1007/1-4020-4697-9_8 panicucci n., bagnoli e. (1986) materiali dell’età del ferro e arcaici dall’ex padule di stagno. in: bandecchi & vivaldi (eds), terre e paduli, reperti documenti e immagini per la storia di coltano. pontedera, 98-106. pascucci v. (2005) neogene evolution of the viareggio basin, northern tuscany (italy). geologica acta, 4, 123-138. pasquinucci m., menchelli s. (1997) isola di coltano. in: zanini a. (ed), dal bronzo al ferro. il ii millennio a.c. nella toscana centro occidentale, pacini, pisa, 49-53. peres j.m., picard j. (1964) nouveau manuel de bionomie benthique de la mer mediterranee. recueil des travaux de la station marine d'endoume, endoume, marseille, 31, 1-137. perini r. (1984) scavi archeologici nella zona palafitticola di fiave´ carera, parte i, campagne 19691976. servizio beni culturali della provincia autonoma di trento, 362 picard j. (1965) recherches qualitative sur les biocenoces marines des substrates meubles dragables de la région marseillaise.recueil des travaux de la station marine d'endoume, endoume, marseille, 36, 160 poggiani l. (2017) insediamento dell’età del bronzo in località chiaruccia. associazione naturalistica argonauta (ed). storia del fiume. il metauro a fano, 68-75. ragaini l., mariani r. (1992) analisi paleoecologica della malacofauna pliocenica di camino tondo (grosseto italia). atti della società toscana di scienze naturali, a, 99, 1-27. rossi v., amorosi a., sarti g., mariotti s. (2017) late quaternary multiple incised valley systems: an unusually well-preserved stratigraphic record of two interglacial valley fill successions from the arno plain (northern tuscany, italy). sedimentology, 64, 1901-1928. doi: 10.1111/sed.12379 (2010) the prehistoric pile dwelling settlement of stagno (leghorn, italy): wood and food resource exploitation. journal of archaeological science, 37, 1260-1268. 10.1016/j.jas.2009.12.027 grifoni cremonesi r. (2006) il neolitico e l’età dei metalli in toscana: sviluppi culturali e strategie insediative. pianeta galileo, atti, 6, 199-211. doi: doi.org/10.4172/2324-8661.1000174 hitchcock l.a., maeir a.m. (2016) a pirate’s life for me: the maritime culture of the sea peoples. palestine exploration quarterly, 1-20. doi: 10.1080/00310328.2016.1250358 jennings b.r. (2014) breaking with tradition cultural influences for the decline of the circum alpine region lake dwellings. sidestone press, leiden, pp. 204. kaniewski d., paulissen e., van campo e., weiss h., otto t., bretschneider j., van lerberghe k. (2010) late second-early first millennium bc abrupt climate changes in coastal syria and their possible significance for the history of the eastern mediterranean. quaternary research, 74, 207-215. doi: 10.1016/j.yqres.2010.07.010 kaniewski d., van campo e., van lerberghe k., boiy t., vansteenhuyse k., jans g., nys k., weiss h., morhange c., otto t., bretschneider j. (2011) the sea peoples, from cuneiform tablets to carbon dating. plos one 6, e20232. doi: 10.1371/journal.pone.0020232 kaniewski d., marriner n., morhange c., vacchi m., sarti g., rossi v., bini m., pasquinucci m., allinne c., otto t., luce f., van campo e. (2018) holocene evolution of portus pisanus, the lost harbour of pisa. scientific reports, 8, 1-14. doi: 10.1038/s41598-018-29890-w livadie c.a., castaldo e., castaldo n., cesarano b., citro d., d’avella a., delle donne m., pappalardo m.t., pizzano n., vannata r. (2010) le strutture abitative e di servizio dell’insediamento dell’età del ferro di longola (poggiomarino na). atti del nono incontro di studi valentano (vt) pitigliano (gr), 539 551. mariani m., prato r. (1988) i bacini neogenici costieri del margine tirrenico: approccio sismico stratigrafico. memorie della società geologica. italiana, 96, 747-762. mariotti lippi m., mori secci m. (2007) ricerche archeobotaniche nella toscana preistorica. informatore botanico italiano, 39, 259-270. mars p. (1950) euryhalinité de quelques mollusques méditerranéens. vie et milieu, 1, 441-448. martins r., sampaio l., quintino v., rodrigues a.m. (2014) diversity, distribution and ecology of benthic molluscan communities on the portuguese continental shelf. journal of sea research, 93, 7589. doi: 10.1016/j.seares.2013.11.006 mazzini i., rossi v., da prato s., ruscito v. (2017) ostracods in archaeological sites along the mediterranean coastlines: three case studies from the italian peninsula. the archaeological and forensic applications of microfossils: a deeper understand 111 the molluscan assemblages of stagno (livorno, italy) rottoli m. (1997) i legni della terramara di castione marchesi. in: bernabò brea m., cardarelli a., cremaschi m. (eds), le terramare. la piu` antica civilta` padana. electa, milano, 481-486. sabelli b., giannuzzi savelli r., bedulli d. (1990) catalogo annotato dei molluschi marini del mediterraneo, bologna, 1-3, 781. sammartino f. (1986) nuovi ritrovamenti del neolitico e dell’età dei metalli nel territorio livornese. atti della società toscana di scienze naturali, a, 93, 295-310. sammartino f. (1997) lago filippo suese. in: zanini a. (ed) dal bronzo al ferro. il ii millennio a.c. nella toscana centro occidentale, pisa, 58. sarti g., rossi v., giacomelli s. (2015) the upper pleistocene “isola di coltano sands” (arno coastal plain, tuscany, italy) review of stratigraphic data and tectonic implications for the southern margin of the viareggio basin. atti della società toscana di scienze naturali memorie, a, 122, 75-84. doi: 10.2424/astsn.m.2015.22 sromek l., forcioli d., lasota r., furla p., wolowicz m. (2019) next generation phylogeography of the cockle cerastoderma glaucum: highly heterogeneous genetic differentiation in a lagoon species. ecology and evolution, 9, 4667-4682. doi: 10.1002/ece3.5070 valsecchi v., tinner w., fisinger w., ammann b. (2006) human impact during the bronze age on the vegetation at lago lucone (northern italy). vegetation history and archaeobotany, 15, 99-113. doi: 10.1007/s00334-005-0026-6 vatova a. (1949) la fauna bentonica dell’alto e medio adriatico. nova thalassia, 1, 110. worms (2023) world register of marine species. www.marinespecies.org at vliz zanini a. (1997) stagno (collesalvetti, li). in: zanini a. (ed), dal bronzo al ferro. pacini, pisa, 103-115. zanini a., martinelli n. (2005) new data on the absolute chronology of late bronze age in central italy. atti liegi, 147-155. 112 catanzariti r. et al. ms. received: july 8, 2024 revised: novenber 4, 2024 accepted: december 1, 2024 available online: december 10, 2024 imp.carveni& la salsa e la gurna di fondachello: evoluzione di un vulcano di fango e di uno stagno costiero all’estrema periferia nord-orientale dell’edificio vulcanico etneo (sicilia) pietro carveni 1, santo benfatto 2, rosanna maniscalco 1, maria salleo puntillo3 & giovanni sturiale 1 1 università di catania, dipartimento di scienze geologiche, corso italia 57, 95129 catania, italia, e-mail: carveni@unict.it 2 geologo, libero professionista, via san marco 91, 95047 paternò, catania, italia. 3 naturalista, via san marco 91, 95047 paternò, catania, italia. riassunto: carveni p., benfatto s., maniscalco r., salleo puntillo m. & sturiale g., la salsa e la gurna di fondachello: evoluzione di un vulcano di fango e di uno stagno costiero all’estrema periferia nord-orientale dell’edificio vulcanico etneo (sicilia). (it issn 03943356, 2006). sulla base di una rilettura critica della letteratura reperita, viene ricostruita l’evoluzione di un vulcano di fango e di uno stagno costiero ubicati al limite nord-orientale dell’etna, lungo la costa ionica. l’attività del vulcano di fango è iniziata in concomitanza del disastroso terremoto dell’11 gennaio 1693; una ripresa della sua attività viene segnalata nel dicembre 1795; questa fase cessa nel 1832; nel marzo del 1847 si ha una nuova fase eruttiva, che culmina con il crollo parziale dell’edificio. dai sopralluoghi risulta che non esiste più alcuna traccia dell’edificio pseudovulcanico, e l’unica attuale manifestazione di attività endogena rilevabile si limita ad emissioni di metano lungo un canale di drenaggio. sulla base di dati di letteratura e dal confronto di carte topografiche edite tra il 1895 e il 2000, viene ricostruita l’evoluzione di uno stagno costiero, la cui genesi potrebbe essere collegata a strutture tettoniche locali, la cui esistenza, in questa sede solo ipotizzata, potrebbe in futuro essere dimostrata tramite l'utilizzo di tecniche di prospezione geofisica. abstract: carveni p., benfatto s., maniscalco r., salleo puntillo m. & sturiale g., the salsa and the gurna near fondachello: evolution of a mud volcano and of a marsh on the farthest north-eastern periphery of mt. etna volcanic edifice (sicily). (it issn 0394-3356, 2006). evolution of a mud volcano and of a marsh are reconstructed in this paper; mud volcano (named salsa di fondachello) and marsh (named gurna di fondachello) were located on the farthest north-eastern periphery of mt. etna volcanic edifice, near the ionian coast. activity of mud volcano started on 1693, 11th january, during a disastrous earthquake; it was again active 1795 to 1832; his last activity started in 1847 march; in this occasion the building collapsed. today there is no trace of this mud volcano. only a little methane emission is the evidence of the endogenous activity. the evolution of a marsh is based on comparison of topographic maps, edited from 1895 to 2000, on bibliography dates and an analysis of existing literature and of a detailed geological-geomorphological survey. today the gurna is reduced to a small swamp and there isn't morphological evidence of the mud volcano; but, considering that the mud volcano has been active three times in historical times, its reactivation today could represent a danger for the surrounding inhabited area. parole chiave: zona etnea, vulcano di fango, stagno costiero, geomorfologia. keywords: mt. etna volcano zone, mud volcano, marsh, geomorphology. il quaternario italian journal of quaternary sciences 19(1), 2006 67-76 1. introduzione all’estrema periferia nord-orientale dell’edificio vulcanico etneo, a piccola distanza dalla costa ionica, nei pressi dell’abitato di fondachello, frazione del comune di mascali, si trova un piccolo stagno costiero, conosciuto un tempo col nome di gurna di pane e vino, attualmente come gurna di fondachello. lungo la sponda sud-orientale dello stagno si formò, in occasione del disastroso terremoto dell’11 gennaio 1693, un vulcano di fango, denominato salsa di fondachello; esso si riattivò nel dicembre del 1795 e rimase in eruzione fino al 1832; una breve ripresa dell’attività, che si concluse con il parziale crollo dell’edificio, fu registrata nel 1847. nel presente articolo, sulla base di una rilettura critica dei dati di letteratura, dell’analisi di aerofotografie e di carte topografiche, e di rilievi geologico-geomorfologici di dettaglio, si effettua la ricostruzione dell’evoluzione della salsa e della gurna di fondachello. con il termine vulcani di fango si indicano gli edifici che si formano in seguito a manifestazioni pseudovulcaniche, consistenti prevalentemente in emissioni di fango, la cui origine è legata all'esistenza nel sottosuolo di gas sotto pressione, i quali tendono a migrare verso la superficie attraverso rocce permeabili e/o discontinuità litologiche e/o strutturali, trascinando nel loro movimento acqua, idrocarburi, fango e frammenti litici. la genesi dei fanghi è da attribuire al passaggio di acqua attraverso formazioni argillose, con conseguente stemperatura delle particelle d'argilla; a seconda della densità del fango emesso, si vengono a formare edifici troncoconici dalle pendici più o meno inclinate e con cavità craterica alla sommità, colate di fango o conche subcircolari piene d’acqua; in genere le acque contengono soluzioni saline, che, precipitando, formano carat68 p. carveni et al. teristiche incrostazioni, da cui il nome di salinelle o salse con cui questi edifici vengono indicati in alcune località. si tratta di morfologie effimere, instabili, che in brevi periodi possono subire profonde trasformazioni, sia in seguito a nuove emissioni, sia a causa degli agenti atmosferici: trattandosi infatti di edifici costituiti prevalentemente da fango, l'insolazione ne provoca la disidratazione, con conseguente formazione di fratture di disseccamento, all'interno delle quali penetrano le acque piovane dando luogo a spinti fenomeni erosivi. per la zona sud-occidentale dell'etna, la risalita di fluidi fangosi è stata recentemente riferita all'esistenza di strutture tettoniche (la manna & carnazzo, 2000) o a condotti vulcanici (carveni et al., 2001). nell'area in esame, mancando qualsiasi evidenza di apparati vulcanici, la risalita dei fluidi potrebbe essere favorita dalla presenza di strutture tettoniche sepolte da alluvioni recenti, la cui esistenza è in questa sede solo ipotizzata, ma che potrebbe essere dimostrata in ricerche future, tramite l'utilizzo di tecniche di prospezione geofisica. la genesi degli stagni costieri è collegata in genere all’esistenza di un mare poco profondo e una costa ricca di insenature in fase di sommersione; è importante la vicinanza di foci fluviali che forniscano cospicue quantità di sabbie e/o ghiaie. in queste condizioni è facile che si formi una barra costiera a piccola distanza dalla costa, in corrispondenza di un’insenatura; la barra può evolvere trasformandosi in tombolo, e la baia diventa una laguna o uno stagno costiero. in altri casi la formazione di uno stagno costiero è geneticamente collegata all’attività di faglie, come verrà dimostrato nel presente articolo. 2. quadro geologico-strutturale dell’area etnea la zona in studio si trova all’estrema periferia nord-orientale dell’edificio vulcanico etneo, lungo la costa ionica. l’etna, con la sua altitudine di poco superiore a 3.300 metri e col diametro massimo di 44 chilometri, è il maggiore vulcano attivo del continente europeo. esso è uno stratovulcano complesso, risultante dalla sovrapposizione dei materiali emessi da diversi centri eruttivi, poggianti su un basamento in parte alloctono, formato da rocce di età compresa tra i l cretaceo ed i l pleistocene (romano et al., 1979). l’edificio vulcanico etneo sorge al limite tra diversi domini strutturali della sicilia orientale (fig. 1), dove la crosta oceanica ionica e la crosta continentale dell’avampaese ibleo si immergono sotto il fronte dell’orogene appenninico-maghrebide (finetti et al., 1996). l’avampaese ibleo costituisce il margine della placca africana (burollet et al., 1978), zona stabile verso cui convergono le falde neogeniche dell’orogene appenninico-maghrebide; esso è costituito da una potente successione prevalentemente carbonatica compresa tra il trias e il pleistocene medio, con intercalati prodotti effusivi basici cretacei, miocenici e pliopleistocenici, la cui risalita è stata favorita da intense fasi tettoniche distensive (cristofolini, 1966; di grande, 1967; 1969; 1972; patacca et al., 1979; carbone et al., 1982; lentini et al., 1986; carbone et al., 1987; carveni et al., 1991 a; 1991 b; 1993; carveni & sturiale, 1999). l’avampaese ibleo confina ad oriente con la crosta oceanica del bacino ionico (finetti, 1982) tramite la scarpata ibleo-maltese, originata da un sistema di faglie normali a gradinata (finetti & morelli, 1972), il cui prolungamento verso settentrione interseca il fianco orientale dell’edificio etneo (lo giudice et al., 1982). il tratto siciliano dell’orogene appenninicomaghrebide si è formato in seguito all’accavallamento della catena kabilo-calabride, costituita da falde di basamento cristallino interessate da metamorfismo ercinico con resti dell’originaria copertura sedimentaria mesocenozoica, sulla catena appenninico-maghrebide, edificio orogenico formato dalla sovrapposizione di falde sud-vergenti (finetti et al., 1996). sulla genesi del vulcano e sul quadro strutturale sono reperibili in letteratura alcuni modelli: 1) intersezione tra due importanti lineamenti strutturali: la scarpata ibleo-maltese e il sistema di faglie messina fiumefreddo (ogniben et al., 1975; mcguire et al., 1997); 2) risultato di una tettonica estensionale che ha portato alla formazione di un graben in corrispondenza dell’attuale piana di catania (di geronimo et al., 1978); 3) processi di rifting tra il blocco maltese siciliano ed il bacino ionico (gillot et al., 1994; continisio et al., 1997); 4) deformazione al footwall di una faglia normale appartenente al sistema distensivo siculo-calabro ad andamento wnw-ese (monaco et al., 1997); 5) risalita di magmi dal mantello a causa di un hot spot (tanguy et al., 1997); 6) roll-back di una porzione di litosfera subdotta al di sotto del mar tirreno (gvirtzman & nur, 1999). a causa di un sollevamento regionale, l’attività eruttiva dell’etna, inizialmente sottomarina e fissurale, è diventata in seguito subaerea ed a carattere centrale; figura 1 schema strutturale della sicilia (da finetti et al., 1996). cs ) catena sicana; cam ) catena appenninicomaghrebide; ckc) catena kabilo-calabride; ai) avampaese ibleo; e) edificio vulcanico etneo; sim) scarpata ibleo-maltese; smf) sistema di faglie messina-fiumefreddo; il quadrato indicato dalla freccia corrisponde alla zona in studio. structural sketch of sicily (after finetti et al., 1996). cs) sicana chain; cam) apennine-maghrebian chain; ckc) kabilocalabrian chain; ai) iblean foreland; e) mount etna volcano; sim) iblean-malta escarpment; smf) messina-fiumefreddo fault system; narrow indicates position of studied area. ciò ha causato una variazione nel meccanismo di risalita dei magmi, con conseguente cambiamento del chimismo: da lave subalcaline si è passati a prodotti più o meno differenziati della serie alcalino-sodica (romano, 1982). carapezza (1962), nel tentativo di determinare una relazione tra la tettonica regionale e le zone di minore resistenza dell’etna, identifica un rift lungo il fianco orientale dell’edificio vulcanico. marchesini et al. (1964) riconoscono quattro principali allineamenti tettonici, con direzioni n-s, ene-wsw, ne-sw e nw-se. frazzetta & romano (1978) identificano due allineamenti alimentatori preferenziali per le aree ad alta probabilità di eruzioni: una nel settore circolare compreso tra ne-sw e enewsw, la seconda con direzione nnw-sse. lo giudice et al. (1982) riconoscono nell'area etnea e nelle zone circostanti varie direttrici di faglie: le più importanti hanno direzione n 60° e, n 30° e, n 15° w e n 60° w. kieffer (1983 a; 1983 b) ipotizza l’esistenza di scivolamenti gravitativi di parte del versante orientale dell’edificio vulcanico, ed attribuisce il fenomeno alla ripetuta intrusione di magma attraverso un rift di ne ed un rift meridionale. l’ipotesi di uno scivolamento gravitativo viene ripresa da azzaro et al. (1989) e da neri et al. (1991). borgia et al. (1992), sulla base dei risultati ottenuti da ferrari et al. (1991) sui dicchi affioranti nella valle del bove, ipotizzano uno spreading radiale del substrato dell’etna verso se. lo giudice & rasà (1992) ritengono invece che si tratti di movimenti puramente gravitativi, che provocano lo scivolamento verso sse della porzione dell’edificio etneo delimitata a settentrione dalla faglia della pernicana (fig. 2: fp) e dal rift di ne (fig. 2: rne), e a sw dalle faglie di mascalucia e trecastagni (fig. 2: fma e ft). la documentazione storica relativa ai terremoti avvenuti sul basso versante orientale etneo negli ultimi due secoli e l’influenza dei movimenti tettonici sulla morfologia sono state analizzate in una serie di articoli (adorni & carveni 1993 a; 1993 69la salsa e la gurna di fondachello ... b; carveni & bella, 1994; bella et al., 1996; carveni et al., 1996; 1997; gresta et al., 1997; carveni et al., 2004; 2005 a; 2005 b). dall’analisi dei sistemi di faglie che nel pleistocene sono stati attivi in sicilia orientale, sulla base di dati geologico-strutturali e morfologici e dell’analisi di sezioni sismiche a mare, monaco & tortorici (1995) e monaco et al. (1995; 1997) distinguono un sistema acireale – sant’alfio (formato da faglie normali figura 2 ubicazione dell'area in studio e delle più importanti strutture tettoniche del versante orientale dell'etna su base dem (pareschi et. al., 1999). faglie: ff) faglia di fondachello; fm) faglia di moscarello; fma) faglia di mascalucia; fmg) faglia milo – giarre; fmr) faglia macchia – riposto; fms) faglia macchia – stazzo; fp) faglia della pernicana; fpvc) faglia praiola – villa calanna; frn) faglia della ripa della naca; frp) faglia della ripa di piscio; fsl) faglia di san leonardello; ft) faglia di trecastagni; ftm) faglia del torrente minissale; ftma) faglia del torrente macchia; sp) sistema di piedimonte. centri abitati: a) acireale; ct) catania; fi) fiumefreddo; fo) fondachello; g) giarre; ma) mascali; m) mascalucia; n) nicolosi; r) riposto; s) stazzo; sa) sant’alfio; t) trecastagni. cc) cratere centrale; rne) rift di ne. location of studied area and of the main tectonic structures of eastern flank of mt. etna volcano; dem after pareschi et. al. (1999): ff) fondachello fault; fm) moscarello fault; fma) mascalucia fault; fmg) milo – giarre fault; fmr) macchia – riposto fault; fms) macchia – stazzo fault; fp) pernicana fault; fpvc) praiola – villa calanna fault; frn) ripa della naca fault; frp) ripa di piscio fault; fsl) san leonardello fault; ft) trecastagni fault; ftm) torrente minissale fault; ftma) torrente macchia fault; sp) piedimonte system. towns: a) acireale; ct) catania; fi) fiumefreddo; fo) fondachello; g) giarre; m) mascalucia; ma) mascali; n) nicolosi; r) riposto; s) stazzo; sa) sant’alfio; t) trecastagni. cc) central crater; rne) ne rift. 70 con componente trascorrente destra nnw-sse) e un sistema di piedimonte (faglie normali e fratture d’estensione nne-ssw); entrambi i sistemi, associati ad un’estensione wnw-ese, formano scarpate di età suprapleistocenico-olocenica, le quali esercitano un controllo sulla topografia e sul reticolo idrografico. con uno studio prevalentemente geomorfologico, basato sull’analisi di aerofotografie, di carte topografiche, di carte nautiche e di cartografia su supporti magnetici, è stato ipotizzato il sistema di faglie giardini – mascali (carveni et al., 2005 a), che potrebbe condizionare la morfologia del sito in studio. 3. lineamenti geologici dell’area nell’area studiata in dettaglio (fig. 3) affiorano prodotti sedimentari e vulcanici di età compresa tra il pleistocene inferiore e l’attuale; la serie stratigrafica affiorante nell’area è costituita, dal basso, dalle seguenti formazioni: 1) calcareniti bianco-giallastre infrapleistoceniche: affiorano sui fianchi della collinetta di serra san biagio, a ne di fiumefreddo di sicilia; si tratta di calcareniti in banchi, con spessore in affioramento di circa 30 metri (fig. 3: 7); sono riferibi l i regionalmente alle calcareniti bianco-giallastre (di grande, 1967; 1969; 1972); 2) argille grigio-azzurre infrapleistoceniche: affiorano lungo un horst con direzione ne-sw a settentrione di fondachello (fig. 3: 6); corrispondono regionalmente alle argil le grigio-azzurre (di grande, 1967; 1969; 1972); 3) piroclastit i dell’unità del trifoglietto affiorano nella parte sud-occidentale della zona in studio (fig. 3: 5); si tratta di piroclastiti di colore bruno giallastro riferibili ai termini basali dell’unità del trifoglietto, la cui attività è iniziata circa 100.000 anni fa (romano, 1982); 4) colate laviche (fig. 3: 4) provenienti dai centri eruttivi del mongibello antico (romano et al., 1979; romano, 1982); 5) alluvioni recenti: sono state deposte dall’alcantara e da altri corsi d’acqua che drenano la zona (fig. 3: 3); 6) la zona è stata interessata da alcune colate laviche datate (fig. 3: 2), relative all’attività del mongibello recente (romano et al., 1979; romano, 1982); 7) alluvioni e depositi di spiaggia attuali chiudono la serie stratigrafica (fig. 3: 1). 4. evoluzione della gurna di fondachello per lo sviluppo di un lago costiero è necessario che vi siano: 1) una zona costiera in fase di sommersione, ricca di insenature; 2) un mare poco profondo; 3) foci fluviali, che forniscano cospicue quantità di sabbie e/o ghiaie. in queste condizioni, è facile che il moto ondoso e/o le correnti marine formino una barra a piccola distanza dalla costa, di fronte ad un’insenatura; se la barra evolve trasformandosi in tombolo, la baia diventa una laguna o uno stagno costiero. le caratteristiche peculiari di uno stagno costiero sono: 1) sponde basse; 2) scarsa profondità; 3) forma allungata parallelamente alla costa. l’aspetto presentato dalla gurna nelle carte più antiche reperite è in effetti quello tipico degli stagni costieri: essa potrebbe essersi formata a causa di un accumulo di sabbie e ghiaie deposte dal moto ondoso, figura 3 schema geologico: 1) alluvioni e depositi di spiaggia attuali; 2) colate laviche del mongibello recente; 3) alluvioni recenti; 4) colate laviche dei centri eruttivi del mongibello antico; 5) piroclastiti dell’unità del trifoglietto; 6) argille marnose azzurre infrapleistoceniche; 7) calcareniti infrapleistoceniche. geological sketch of studied area: 1) present day alluvium and shoreline deposits; 2) lavas flows from the eruptive centres of mongibello recente 3) recent alluvium; 4) lavas flows from the eruptive centres of mongibello antico; 5) pyroclastics from trifoglietto unit; 6) early pleistocene bluish marly clays; 7) early pleistocene calcarenites. p. carveni et al. 71 ma non sono rispettate le altre condizioni: non vi sono insenature e i corsi d’acqua che sboccano nelle immediate vicinanze, il torrente fiumefreddo e il torrente delle forche hanno scarsa portata solida; inoltre la profondità del mare aumenta repentinamente con la lontananza dalla costa (istituto idrografico della marina, 2001). per questi motivi, i dati provenienti dalla ricerca hanno fatto scartare l’ipotesi di una genesi sedimentaria del bacino e hanno fatto ipotizzare un'origine legata a cause tettoniche. recupero (1815), nel suo lavoro pubblicato postumo, e redatto precedentemente al 1778, descrive una palude costiera, chiamata azanetto o cottone, ubicata tra la piana di mascali ed il mare; si può ipotizzare che nel xviii secolo il bacino della gurna fosse più grande, e che in seguito, per fenomeni di interramento e/o legati alla siccità e/o ad opere di bonifica, la sua estensione sia diminuita, dando luogo ad una serie di bacini di minori dimensioni. galvagni (1839), in uno studio sulle paludi della sicilia, ne descrive tre esistenti nella zona di mascali: urna di pane e vino, estesa circa una salma (3,43 ettari); auzini, estesa circa due salme (6,86 ettari) e già da alcuni anni bonificata; azzanetto, molto prossima alla spiaggia. secondo mercurio (1847) tra il 1839 e il 1846, a causa di un lungo periodo di siccità, le sorgenti gebbia, fico e panevino, che alimentavano la gurna di fondachello, si estinsero, e il bacino si prosciugò; nell'ottobre 1846, con la ripresa delle piogge, le sorgenti si riattivarono e il bacino lacustre tornò a riempirsi d'acqua. sulla più antica carta topografica da noi reperita (i.g.m., 1895) la gurna ha forma grossolanamente triangolare, con il lato maggiore in direzione ne-sw, lungo la scarpata della faglia di fondachello, una superficie di circa 8.300 metri quadrati; essa risulta alimentata da una serie di sorgenti a settentrione (sorgenti panevino), allineate in direzione nw-se, lungo un presunto piano di faglia, evidenziato dall’allineamento delle sorgenti e dall’andamento delle isoipse, da due sorgenti all’estremità sud-orientale (sorgenti gebbia e fico) e da una sorgente ubicata ad occidente (sorgente di case decime) (fig. 4 a); lo sbocco al mare avveniva per tracimazione. nelle carte del 1938 (i.g.m., 1938) la gurna si è ridotta ad una zona paludosa, alimentata dalle sorgenti gebbia e fico; le sorgenti panevino sono estinte e la loro zona è occupata da acquitrini; la sorgente di case decime è ancora alimentata, e una nuova sorgente si è formata ad oriente del vecchio bacino della gurna; le zone acquitrinose sono drenate da canali (fig. 4 b). il panorama cambia nelle carte del 1967 (i.g.m., 1967): con la dicitura la gurna viene indicato il canale che raccoglie le acque delle sorgenti gebbia e fico, e nel quale confluiscono altri canali; sulla carta non c’è traccia di zone paludose (fig. 4 c). la situazione si presenta praticamente identica nel 1974 (i.g.m., 1974), mentre nelle carte del 1987 (regione siciliana, 1987) e del 2000 (provincia regionale di catania, 2000) è riportato solamente il canale che convoglia le acque delle sorgenti gebbia e fico e non gli altri (fig. 4 d). la genesi della gurna e degli altri bacini locali potrebbe essere attribuita, nel contesto del sollevamento generale della zona etnea, ad un abbassamento differenziale di una parte della pianura costiera limitata ad oriente dalla presunta faglia di fondachello. 5. evoluzione della salsa di fondachello secondo boccone (in alibrandi, 1985), in occasione del disastroso terremoto dell’11 gennaio 1693 si formò, tra la costa del mar jonio e la gurna di fondachello, una fontana di acqua fangosa che raggiungeva i 32 metri di altezza (fig. 5, d). recupero (1815), nella sua accurata descrizione dei luoghi, esplorati prima del 1778, non fa alcuna menzione del vulcano di fango: se ne deduce che gli agenti atmosferici avevano del tutto eroso tale edificio, e tra gli abitanti del luogo non se ne era conservata la memoria. nel corso di una notte non precisata del dicembre 1795, nei dintorni di fondachello furono avvertite numerose scosse sismiche, accompagnate da rumori provenienti dal sottosuolo (mercurio, 1847); chi all'alba si recò sulla sponda della gurna vide che sull'orlo sudorientale del bacino si era formata una fontana di acqua fangosa alta fino a 6-7 metri. l'intensità del fenomeno diminuì gradatamente e, tre mesi dopo l’inizio dell’attività, dall'orlo del cratere dell'edificio che nel frattempo si era formato per l’accumulo di fango, sgorgava tranquillamente un'acqua fangosa ricca di gas, che si riversava, stemperandosi, nel bacino lacustre. nel 1832, quando questo periodo di attività cessò, il vulcano di fango era alto 3,6 metri rispetto al livello dell'acqua della gurna, e 6,1 metri rispetto al livello del mare (fig. 5, c). nel marzo del 1847 vi fu una ripresa dell'emissione di acqua fangosa, preceduta da una serie di scosse sismiche (tab. 1); tre di esse, più forti delle precedenti, si verificarono rispettivamente durante la notte tra il 25 e il 26 marzo, all'alba del 26 marzo, e l’ultima, che fu avvertita anche a catania, alle 19,30 dello stesso giorno. durante la notte del 9 aprile 1847 gli abitanti di fondachello udirono un'esplosione; il mattino successivo si vide che la base orientale del vulcano di fango era sprofondata, e si era formata una cavità ellittica che andava lentamente riempiendosi di acqua gorgogliante a causa del gas di cui era ricca; l'asse maggiore con direzione e-w era lungo 18,6 metri, l’asse minore 13,4 metri. il 10 maggio 1847 gli assi giunsero a 23 e 19,3 metri, mentre il livello dell'acqua si trovava a 4,8 metri dall'orlo delle sponde e la profondità del bacino, misurata in diversi punti, era di circa 4 metri. lungo le sponde del bacino mercurio (1847) riconobbe, dall'alto in basso, 4 diversi strati (fig. 6): a) il più alto, con spessore variabile da 1,95 metri nel punto più vicino ai resti del cono del vulcano di fango a 0,3 metri sulla sponda opposta, era formato dal fango emesso nel periodo di attività 1795-1832; b) il secondo strato era costituito da sabbie e ciottoli, presumibile deposito di spiaggia, con spessore costante di 0,3 metri; c) il terzo, composto da fango, presentava uno spessore massimo di 1,3 metri nei pressi del vulcanetto e si riduceva a zero all'altra estremità del bacino; a nostro avviso questo strato di fango è da attribuirsi all'attività iniziata in concomitanza con il terremoto dell'11 gennaio 1693; d) infine affiorava uno strato di paleosuolo con sabbia e la salsa e la gurna di fondachello ... 72 ciottoli. la superficie dell'acqua nel bacino di neo formazione si trovava a 1,6 metri al di sotto del livello del mare e a 1,1 metri al di sotto del livello dell'acqua della gurna; le sue acque erano continuamente agitate a causa della grande quantità di gas che si sprigionava, in particolare da due punti, uno nelle immediate vicinanze del condotto del vulcano di fango, l'altro al punto opposto dell'ellisse. attualmente non vi è alcuna traccia del vulcano di fango, e l’unica manifestazione di origine endogena riscontrata nel territorio è un’emissione di metano lungo un canale di drenaggio (d’alessandro et al., 1997); questo punto di emissione, comunque, non corrisponde all’ubicazione attribuibile alla salsa di fondachello in base ai dati di letteratura: infatti, secondo mercurio figura 4 topografia della zona della gurna di fondachello: a) sulla base del quadrante “riposto”, i.g.m., 1895; b) sulla base della tavoletta “fiumefreddo di sicilia”, i.g.m., 1938; c) sulla base della tavoletta “fiumefreddo di sicilia”, i.g.m., 1967; d) sulla base della carta tecnica della provincia regionale di catania, scala 1:10.000, sezione 625030. topography of gurna di fondachello zone: a) based on “riposto” 1:50,000 scale map edited by italian military geographic institute in 1895; b) , based on “fiumefreddo di sicilia” 1:25,000 scale map edited by italian military geographic institute in 1938; c) based on “fiumefreddo di sicilia” 1:25,000 scale map edited by italian military geographic institute in 1967; d) based on provincia regionale di catania 1:10,000 scale map, 625030 section. p. carveni et al. (1847) il vulcano di fango sorgeva sulla sponda sudorientale della gurna (fig. 4 a), mentre le emissioni gassose oggi osservabili si trovano in corrispondenza della sponda occidentale di ciò che resta del bacino lacustre (fig. 4 d). 5. conclusioni sulla base di un’analisi della scarsa letteratura esistente e di un dettagliato studio geologico-geomorfologico, si ricava che: 73 fig. 5 ricostruzione morfologica della gurna dal momento della sua formazione e della salsa di fondachello dal 1693 ai giorni nostri. morphological evolution of gurna marsh from the moment of its formation and of salsa di fondachello mud volcano from 1693 to present time. la salsa e la gurna di fondachello ... 1) il basso versante nord-orientale dell’etna è stato interessato dall’attività di faglie dirette, le quali, nell’ambito di un generale sollevamento dell’edificio etneo, hanno provocato una serie di abbassamenti localizzati, con conseguenti fenomeni di subsidenza; queste faglie hanno agito sull’andamento della linea di costa e sul reticolo idrografico, causando la formazione di alcuni stagni costieri, attualmente in parte bonificati, in parte in via di estinzione, tra i quali il più importante è la gurna di fondachello; 2) la salsa di fondachello era un vulcano di fango formatosi in occasione del disastroso terremoto dell’11 gennaio 1693; poiché esso non viene né descritto né nominato da recupero (1815), il quale esplorò la zona nella seconda metà del diciottesimo secolo, si può ipotizzare che in quel periodo non se ne conservava alcuna traccia; 3) l’attività della salsa riprese nel dicembre del 1795, accompagnata da scosse sismiche; le emissioni di fango durarono, in fase decrescente, fino al 1832; 4) una nuova fase parossistica (marzo – aprile 1847) fu accompagnata da uno sciame di sismi, l’ultimo dei quali talmente forte da essere avvertito fino a catania; si trattò chiaramente non di un sisma legato all’attività della salsa di fondachello, ma al contrario fu il movimento tettonico ad influenzare l’evoluzione del vulcano di fango. si ipotizza che l’origine dei laghi costieri della zona e del vulcano di fango sia collegata alla tettonica locale: all’attività della faglia di fondachello si potrebbe addebitare lo sbarramento che ha provocato la nascita dei laghi costieri e l’apertura della frattura attraverso la quale è avvenuta la fuoriuscita del fango della salsa di fondachello. attualmente, mentre della gurna rimane solo una piccola zona acquitrinosa, non si hanno tracce dell’ubicazione della salsa: poiché essa stava sull’orlo sud orientale della gurna, la sua ubicazione non può corrispondere a quella del punto di emissione di gas (confronta le figure 4a e 4d). in considerazione del fatto che il vulcano di fango è stato attivo almeno tre volte, e che la zona di fondachello sta vivendo una fase di forte urbanizzazione, nonostante i vincoli imposti quale sito di interesse comunitario sic (ita070003 – la gurna) e zona di protezione speciale, si ritiene che una sua non improbabile riattivazione potrebbe causare ingenti danni se non si attuassero gli strumenti di pianificazione territoriale a tutela del geosito ed area naturalistica protetta de la gurna. studio effettuato con i fondi del m.i.u.r., nell’ambito delle ricerche morfodinamica di zone vulcaniche e/o sismicamente attive morfodinamica di zone costiere sismicamente attive, responsabile pietro carveni. 74 tabella 1 data fenomeni zona di osservazione attività della salsa terremoto disastroso nascita del vulcano di fango, 1693 gen. 11 (xi scala mercalli) sicilia orientale. con emissione di acqua fangosa fino a 32 metri di altezza. numerose scosse durante nelle contrade attorno emissione di acqua fangosa 1795 dic. tutta la notte, accompagnate alla gurna. fino a 6-7 metri di altezza. da rombi sotterranei. 1847 mar. 25 scosse nelle contrade attorno ripresa dell’attività. alla gurna. 1847 mar. 26, scosse nelle contrade attorno nessuna h 06,15 alla gurna. 1847 mar. 26, h 19,30 scosse fino a catania. nessuna nelle contrade attorno crollo del fianco orientale del 1847 apr. 9 esplosione alla gurna. vulcano di fango ed intensa emissione di acqua ricca di gas. figura 6 ricostruzione della stratigrafia dei depositi attorno al vulcano di fango, da mercurio, 1847. stratigraphy of deposits around mud volcano, after mercurio, 1847. p. carveni et al. ringraziamenti ringraziamo il prof. italo di geronimo per la lettura critica del manoscritto, e i referees per gli utili e costruttivi consigli. lavori citati adorni g. & carveni p. (1993 a) geomorphology and seismotectonic elements in the giarre area, sicily. earth surf. proc. land., 18, 275-283. adorni g. & carveni p. (1993 b) anomalie del reticolo idrografico causate da eventi sismotettonici sul basso versante orientale dell’etna. boll. acc. gioenia sc. nat. catania, 26 (342), 197-206. alibrandi a. (1985) prefazione alla ristampa anastatica di mercurio g.a. (1847) sulla salsa di fondachello nel comune di mascali, del profondamento parziale del cono argilloso e dell'apparizione d'un'acqua minerale gassosa. stabilimento di pietro giuntini, catania, 29 pp. azzaro r., carveni p., lo giudice e. & rasà r. (1989) il terremoto di codavolpe (basso versante orientale etneo) del 29 gennaio 1989: campo macrosismico e fratturazione cosismica. boll. g.n.v., 1, 1-12. bella d., carveni p., musumeci c. & gresta s. (1996) aspetti geomorfologici conseguenti all'attività sismica locale sul basso versante orientale del vulcano etna. il quaternario, 9 (1), 365-368. borgia a., ferrari l. & pasquarè g. (1992) importance of gravitational spreading in the tectonic and volcanic evolution of mt. etna. nature, 357, 231-235. burollet p.f., mugnot g.m. & sweeney p. (1978) the geology of the pelagian block: the margins and basins of southern tunisia and tripolitania. in: nairn a., kanes w. & stelhi f.g., eds., the ocean basins and margins, plenum press, new york, 331-339. carapezza m. (1962) un esempio di eruzione laterale da faglia nell’apparato eruttivo etneo. acta geol. alpina, 8, 249-276. carbone s., grasso m. & lentini f. (1982) elementi per una valutazione degli eventi tettonico-sedimentari dal cretaceo al quaternario nella sicilia sud-orientale. in catalano r. & d’argenio b., eds., guida alla geologia della sicilia occidentale. soc. geol. it., palermo, 103-109. carbone s., grasso m. & lentini f. (1987) lineamenti geologici del plateau ibleo (sicil ia s.e.). presentazione delle carte geologiche della sicilia sud-orientale. mem. soc. geol. it., 38, 127-135. carveni p. & bella d. (1994) aspetti geomorfologici legati ad attività sismica su vulcani attivi: il basso versante orientale dell'etna come modello di studio. boll. acc. gioenia sc. nat., 27 (346), 253-285. carveni p., bella d., filetti g., leonardi m.c., musumeci c. & sturiale g. (1996) zonazione sismica del territorio di giarre (catania) mediante l'analisi di sismi locali avvenuti nel periodo 18551989. att. conv. lincei, "la stabilità del suolo in italia: zonazione sismica-frane", 134, 389-393. carveni p., benfatto s., maniscalco r., salleo m. & sturiale g. (2004) seismic hazard along san leonardello graben, on the lower eastern slope of mt. etna volcano. 1st int. conf. applied geophysics for engineering, 13th – 15th october 2004, messina, italy, abstracts, 7. carveni p., benfatto s., maniscalco r., salleo m. & sturiale g. (2005 a) controllo tettonico sulla morfologia del basso versante nord-orientale dell’etna (sicilia). il quaternario, 18 (2), 57-68. carveni p., benfatto s. & sturiale g. (2001) aspetti geologici e geomorfologici dei vulcani di fango del basso versante sud-occidentale etneo ed ipotesi sulla loro genesi. il quaternario, 14 (2), 117-130. carveni p., bella d., benfatto s., maniscalco r., salleo puntillo m. & sturiale g. (2005 b) sollevamenti a grande scala e conseguenti fenomeni gravitativi: l’esempio del versante orientale dell’etna (sicilia). il quaternario, 18 (2), 157-171. carveni p., filetti g. & bella d. (1997) aspetti geomorfologici e sismologici connessi a fenomeni di tettonica gravitativa nel basso versante orientale dell'etna. geogr. fis. dinam. quat., 20, 43-49. carveni p., grasso m.f., romano r. & tricomi s. (1991 a) vulcanismo del margine settentrionale ibleo. mem. soc. geol. it., 47, 417-429. carveni p., leonardi a. & romeo m. (1993) rapporti tra vulcaniti submarine e depositi plio-pleistocenici dei dintorni di palagonia (avampaese ibleo, sicilia). boll. acc. gioenia sc. nat., vol. 26, 342, 207-237. carveni p., romano r., capodicasa a. & tricomi s. (1991 b) geologia dell’area vulcanica di capo passero (sicilia sud-orientale). mem. soc. geol. it., 47, 431-447. carveni p. & sturiale g. (1999) fasi tettoniche, fenomeni vulcanici e geomorfologia della zona di monte casale di san basilio, lungo il margine settentrionale dei monti iblei (sicilia orientale). il quaternario, 12 (1), 85-98. continisio r., ferrucci f., & gaudiosi g. (1997) malta escarpment and mt etna: early stages of an asymmetric rifting process? evidences from geophysical and geological data. acta vulcanologica, 9, 45-53. cristofolini r. (1966) le manifestazioni eruttive basiche del trias superiore nel sottosuolo di ragusa. per. min., 35, 1-38. d’alessandro w., de gregorio s., dongarrà g., gurrieri s., parello f. & parisi b. (1997) chemical and isotopic characterization of the gases of mount etna (italy). journ. volc. geoth. res., 78, 65-76. di geronimo i., ghisetti f., lentini f. & vezzani l. (1978) lineamenti neotettonici della sicilia orientale. mem. soc. geol. it., 19, 543-549. di grande a. (1967) i sedimenti pleistocenici del margine settentrionale dell’altipiano ibleo. att. acc. gioenia sc. nat., catania, serie vi, 18 (suppl. sc. geol.), 247-263. di grande a. (1969) l’alternanza neogenico-quaternaria di vulcaniti e sedimenti al margine nord-occidentale dell’altipiano ibleo. att. acc. gioenia sc. nat., catania, 4, 36 pp. di grande a. (1972) geologia dell’area a nord di augusta francofonte (sicilia se). att. acc. gioenia sc. nat., s. 7, 4, 1-32. ferrari l., garduņo v.h. & neri m. (1991) – i dicchi della valle del bove, etna: un metodo per stimare le dilatazioni di un apparato vulcanico. mem. soc. geol. it., 47, 495-508. 75la salsa e la gurna di fondachello ... finetti i. (1982) structure, stratigraphy and evolution of central mediterranean. boll. geof. teor. appl., xxvi, 96, 247-312. finetti i., lentini f., carbone s., catalano s. & del ben a. (1996) il sistema appennino meridionale arco calabro sicilia nel mediterraneo centrale: studio geologico-geofisico. boll. soc. geol. it., 115, 529-559. finetti i. & morelli c. (1972) wide scale digital seismic exploration of the mediterranean sea. boll. geof. teor. appl., 14, 291-342. frazzetta g. & romano r. (1978) approccio di studio per la stesura di una carta del rischio vulcanico (etna-sicilia). mem. soc. geol. it., 19, 691-697. galvagni g.a. (1839) memorie di geografia fisicomedica sulle principali acque stagnanti di sicilia e sulle febbri intermittenti a che mettono cagione. memoria prima: delle acque stagnanti dei contorni dell’etna e della piana di catania. att. acc. gioenia, 16, 9-85. gillot p.y., kieffer g. & romano r. (1994) the evolution of mount etna in the light of potassium-argon dating. acta vulcanologica, 5, 81-87. gresta s., bella d., musumeci c. & carveni p. (1997) some efforts on active faulting processes (earthquakes and aseismic creep) acting on the eastern flank of mt. etna (sicily). acta vulc., 9 (1/2), 101-108. gvirtsman z. & nur a. (1999) the formation of mount etna as the consequence of slab rollback. nature, 401, 782-785. istituto geografico militare (1895) f°. 262 della carta d’italia, ii quadrante, "riposto", scala 1:50.000. firenze. istituto geografico militare (1938) f°. 262 della carta d’italia, ii n.o., “fiumefreddo di sicilia”, scala 1:25.000. firenze. istituto geografico militare (1967) f°. 262 della carta d’italia, ii n.o., “fiumefreddo di sicilia”, scala 1:25.000. firenze. istituto geografico militare (1974) f°. 625acireale, serie m 792, foglio nj 33-11-d1. scala 1:50.000. firenze. istituto idrografico della marina italia (2001) foglio 22, da capo santa croce a messina e capo dell’armi, scala 1:100.000. genova. kieffer g. (1983 a) l’évolution struttural de l’etna (sicile) et les modalités du contrôle tectonique et volcanotectonique de son activité. faits et hypothèses après les éruptions de 1978 et 1979. rev. géogr. phys. géol. dyn., paris, 24 (2), 129-152. kieffer g. (1983 b) dèplacement progressif vers l’est des voies d’alimentation magmatiques de l’etna (sicile). bull. soc. géol. fr., 25 (3), 369-378. lentini f., carbone s., cucno c., grasso m., scamarda g. & sciuto f. (1986) carta geologica del settore nord-orientale ibleo (sicilia s.e.). scala 1:50.000, s.e.l.ca., firenze. la manna f. & carnazzo a. (2000) le salinelle di paternò: nuova ipotesi sulla loro struttura e formazione. boll. soc. geol. it., 119, 9-14. lo giudice e., patanè g., rasà r. & romano r. (1982) the structural framework of mt. etna. mem. soc. geol. it., 23, 125-158. lo giudice e. & rasà r. (1992) very shallow earthquakes and brittle deformations in active volcanic areas: the etnean region as an example . tectonophysics, 202, 257-268. marchesini e., conedera c., morabito g. & macii l. (1964) studio fotogeologico dell'etna. riv. min. sic., 85-87, 83-95. mcguire w.j., stewart i.s. & saunders s.j. (1997) intravolcanic rifting at mount etna in the context of regional tectonics. acta vulcanologica, 9, 147-156. mercurio g.a. (1847) sulla salsa di fondachello nel comune di mascali, del profondamento parziale del cono argilloso e dell'apparizione d'un'acqua minerale gassosa. stabilimento di pietro giuntini, catania, 29 pp. monaco c., petronio l. & romanelli m. (1995) tettonica estensionale nel settore orientale del monte etna (sicilia): dati morfotettonici e sismici. studi geologici camerti, convegno geodinamica e tettonica attiva del sistema tirreno-appennino, 363-374. monaco c., tapponnier p., tortorici l. & gillot p.y. (1997) late quaternary slip rates on the acirealepiedimonte normal faults and tectonic origin of mt. etna (sicily). earth planet. sc. lett., 147, 125-139. monaco c. & tortorici l. (1995) tettonica estensionale quaternaria nell’arco calabro e in sicilia orientale. studi geologici camerti, convegno geodinamica e tettonica attiva del sistema tirreno-appennino, 351-362. neri m., garduņo v.h., pasquarè g. & rasà r. (1991) studio strutturale e modello cinematico della valle del bove e del settore nord-orientale etneo. acta vulcanologica, 1, 17-24. ogniben l., parotto m. & praturlon a. (1975) structural model of italy. c.n.r., quaderni de “la ricerca scientifica”, 90, 502 pp. pareschi m.t., cavarra l., favalli m., innocenti f. & pasquarè g. (1999) digital atlas of the mt. etna volcano. acta vulcanologica, 11 (2), 311-314. patacca e., scandone p., giunta c. & liguori v. (1979) mesozoic paleotectonic evolution of the ragusa zone (se sicily). geol. romana, 18, 331-369. provincia regionale di catania (2000) carta tecnica, sezione n° 625030, scala 1:10.000. recupero g. (1815) storia naturale e generale dell’etna. 2 voll., 580 pp. regione siciliana, assessorato del territorio e dell’ambiente (1987) carta tecnica regionale, sezione n° 625030 “fiumefreddo di sicilia”, scala 1:10.000. romano r. (1982) succession of the volcanic activity in the etnean region. mem. soc. geol. it., 23, 27-48. romano r., lentini f., sturiale c., amore c., atzori p., carter s.r., cristofolini r., di geronimo i., di grande a., duncan a.m., ferrara v., ghisetti f., guest j.e., hamill h., patanè g., pezzino a., puglisi d., schilirò f., torre g. & vezzani l. (1979) carta geologica del monte etna, scala 1:50.000, litogr. art. cartogr., firenze. tanguy j.c., condomines m. & kieffer g. (1997) evolution of the mount etna magma: constraints on present feeding system and eruptive mechanism. jour. volc. geot. res., 75, 221-250. 76 ms. ricevuto il 3 maggio 2006 testo definitivo ricevuto il 12 settembre 2006 ms. received: may 3, 2006 final text received:september 12, 2006 p. carveni et al. available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 37 (2), 2024, 89-101 et al., 2023). after its formation, a sinkhole due to deep piping/ suffosion can have several evolutions. one of the most frequent is drowning, in which groundwater pours into the depression forming a small lake, the level of which may fluctuate over time or remain constant. another possible evolutionary path is extinction, in which the sinkhole dries out and fills up (also by human action) until it becomes extinct, although this does not exclude possible reactivation over time. if reactivation does not take place in the same position as the initial sinking, then we speak of migration, which may be due to the variation of the fluid's ascent paths, also as a result of seismic events or the remote repetition of similar phenomena. based on this knowledge, it is possible to identify areas with geological features that favour these types of sinkholes. in addition to what has already been mentioned, for example, the presence of other sinkholes and small lakes, the disappearance/reappearance of springs, and the presence of confined aquifers are clues that make it possible to identify vast areas where sinkholes could occur. the combined use of geotematic knowledge with historical and archaeological records has yielded good results in the past, especially in the area of anthropogenic sinkholes (madonna et al., 2023). this knowledge could be supplemented by the use of historical and recent orthophotos of the territory, in order to study the evolution of the site of a fairly recent sinkhole over time, especially in its pre-sinkhole state, in search of other clues that would allow the identification of factors common to several sites, even spatially distant ones. today, https://doi.org/10.26382/amq.2024.05 1. introduction natural sinkholes occurring in alluvial plains are generally related to deep piping and suffosion phenomena. over time, these sinkholes have been studied and the processes of their formation described. a sinkhole due to deep piping is generated under precise geological conditions, which generally involve a karstic bedrock (or permeable) covered by soft deposits with variable grain size from sandy to silty-clayey (nisio, 2008a). the presence of geological discontinuities, such as faults, favors these types of processes, providing a preferential route along which fluids rise. suffosion sinkholes, on the other hand, originate through erosion phenomena from below with the formation of vertical and sub-horizontal conduits that, however, only affect the first few metres of the overburden (nisio, 2008a). in both phenomena, the movement of water erodes the superficial layers of the land cover, even leading to the creation of cavities. when the erosion phenomena are very pronounced or the cavities reach a critical size, sinking to the surface occurs. the recent collapse in the vepe caldera in the municipality of latera, in the province of viterbo, suggests that deep piping and suffosion phenomena may also be active in volcanic contexts, leading to the formation of sinkholes (puzzilli et al., 2024). this sinkhole was studied using a combined multidisciplinary approach. multidisciplinary methodologies have also been applied with good results in the research of karstic cavities in apulia, making it possible to study these structures in the area of the gravaglione sinkhole (romano integrated use of orthophotos and geo-thematic knowledge for sinkhole risk mitigation in quaternary alluvial plains francesco gentili 1 , francesco giuseppe rossi 2 1 dipartimento di ecologia e biologia, università degli studi della tuscia, viterbo, italy. 2 freelance geologist, viterbo, italy. corresponding author: francesco gentili <francesco.gentili@unitus.it> abstract: sinkholes formation is a widespread reality in italy, but it is often not as well known as other hazards, such as landslides and earthquakes. the study of these phenomena has led over time to a better understanding of sinkholes and their associated formation mechanisms. in this work, we focused on sinkholes that originate in alluvial contexts, mostly due to deep piping and suffosion phenomena. the objective was to verify the presence of common evidence by observing the sites of 29 sinkholes before and after the collapse phase through the study of historical and recent orthophotos. after producing an initial list of surface evidences common to several sinkholes, various areas in the italian alluvial plains were examined that maintained the catalogued evidences in the orthophotos. on the basis of these evidences, the number and quality of previous geothematic knowledge and the ease of access, an area in southern tuscany was selected, where photogrammetric surveys, geophysical surveys and analysis of rainfall data were carried out to verify possible connections with deep piping/suffosion phenomena potentially active in the area and the surface evidences found in the orthophotos. keywords: sinkholes, alluvial plains, geophysics, orthophotos, photogrammetry. thanks to the presence of dedicated web portals and their dissemination, it is easy to access these tools, covering a time span potentially ranging from the 1940s to the present day, making a large number of images available. the work presented in this article aims to initially identify these common characteristics by analyzing historical and recent orthophotos of various sinkholes (attributable to deep piping and suffosion) present in the italian national territory. based on insights gained from orthophoto analysis combined with prior geological knowledge, an area in southern tuscany (municipality of grosseto) was identified, exhibiting features similar to those observed at other sinkhole sites before collapse. in-depth investigations were conducted in this area using photogramme-tric surveys, surface seismic surveys and analysis of rainfall data, as well as retrieval of previous studies and investigations carried out in the area. the aim is to contribute to enhance current methods for identifying areas at risk and susceptible to sinkhole formation by utilizing information derived from orthophoto analysis. 2. materials and methods the methodology employed initially involved the study of bibliographic material relating to different parts of italy where sinkholes have occurred due to piping and suffosion, for which aerial images and available orthophotos dating back to different time periods were retrieved in order to study the pre-collapse state and postcollapse evolution. based on the orthophoto analysis, several study areas were selected where the geological context was already known, and where features resembling precollapse sinkhole indicators were visible. among these areas, a specific site in the grosseto province was identified, where detailed field studies which included photogrammetric surveys, geophysical investigations and analysis of rainfall data were available. the initial step was therefore a literature review in search of sinkholes formed in the last 70-80 years (campobasso et al., 2004; caramanna et al., 2008; centamore et al., 2009; del prete et al., 2008; nisio, 2008b; nisio, 2008c; nisio, 2008d; nisio, 2008e; nisio, 2008f; nisio, 2008g; nisio, 2008h; nisio, 2008i; nisio, 2008l) as a result of deep piping/suffosion phenomena and for which historical and recent orthophotos of the sites were available. available orthophotos were collected for a period between 1940 and 2023, of the study sites occurring in the literature, national regional igm and google earth map portals were examined as well as aerial photos from the 1940s. the second step involved the construction of a gis project, realised with the open-source software qgis version 3.16 “hannover” (qgis development team, 2020). for each site, historical and recent orthophotos were collected in georeferenced format, ascertaining a complete and perfect overlap with the regional technical cartography elements. the aerial photographs and orthophotos with no spatial reference were georeferenced manually using the qgis tool 'georeferencer', which requires the identification of 4 homologous points for the georeferencing process to take place. to facilitate this procedure, the vector formats of the hydrography and road graphs were obtained from the regional portals, so that the homologous points could be easily identified. the limits of the sinkholes were vectorized by drawing them on the georeferenced orthophotos. for illustrative purposes and ease of discussion, based on the photographic availability, representativeness and classification of sinkholes, from initial 29 cases, five sinkholes were selected for this research. figure 1 shows the sites of the examinated sinkholes on the map and table 1 shows the wgs84 geographical coordinates of each site. the images of these sites were taken from the national geoportal (geoportale nazionale, 2024), the tuscany region portal (geoscopio, 2024), the lazio region portal (geoportale regione lazio, 2024), the sardinia region portal (sardegna geoportale, 2024) the istituto geografico militare (igm, 2024) and google earth (google earth, 2024). information about the metadata and characteristics of the images can be consulted directly on the mentioned portals. for latera site only, a georeferenced uav photogrammetric survey was carried out to obtain the sinkhole limits in a vector format. this step was indispensable to obtain an orthophoto of the sinkhole as it was not yet available. the use of uavs for scientific purposes is now common practice and, with due support, reliable and accurate for obtaining accurate dtms (digital terrain models) and orthophotos (gentili & madonna, 2024; pingel et al., 2021; puzzilli et al., 2024). the latter survey was carried out using the dji mavic pro uav (unmanned aerial vehicle), supported by gpss (ground control points) and cps (control points) on the ground measured using a leica gnss (global navigation sat 90 gentili f., rossi f.g. tab. 1 coordinates of the analysed sinkholes sites. fig. 1 outline of italy with the location of the studied sinkhole areas. 1) bottegone and selected area for field surveys, 2) san donato 1 and 2, 3) latera, 4) guardia dei merli, 5) sennes. relations between the presence of certain signals in the orthophotos and rainwater, the data from the available rainwater stations were analysed. to this end, the data from the rain gauge stations made available by the region of tuscany (www.sir.toscana.it/consistenza-rete) were examined, in particular those of braccagni, stiacciole, batignano, caldana and casotto dei pescatori, due to their proximity to the study site. rainfall data for august 2013, february 2015, august 2019, september 2019 and march 2023 were processed to make direct comparisons with the available orthophotos. the weighted distance method inversion (idw, goovaerts, 2012; noori et al., 2014) was applied in a gis environment to better analyse the rainfall data (tab. 3). due to the lack of data from the bitignano station in the years 2013 and 2015, this method was only used for the years 2019 and 2023. 3. investigated area various georeferenced orthophotos with projected sinkhole boundaries were exported from the gis project. in the following part of the study, a brief description of each sinkhole site, geological context and photographic compositions obtained are reported. bottegone. this sinkhole formed in january 1999 near the plain north of grosseto, in the vicinity of the fattoria degli acquisti. the geology consists of alluvial deposits with a silty-clay grain size resting on a carbonate substrate that can be located at a deep of around 200 m, with the presence of several direct faults (del greco et al., 2004). initial studies hypothesised a formation due to the collapse of a karstic cavity in the substrate, which produced a subsidence path that caused surface subsidence. subsequently, a hypothesis was put forward that sees deep piping as another possible cause, as it seems unlikely, due to the thickness of the overburden materials, that surface subsidence could occur. impermeable or semi-permeable clay sediments may be able to absorb the deformations generated at depth (nisio et al., 2004; nisio, 2008a). as recent studies point out (liang et al., 2018), karst sinkholes are generally found where sediment thickness is reduced. to date, the sinkhole is filled with water with a diameter of 170m and a depth of 17m. for example purposes, figure 2 shows the orthophotos of 1954 (a), 1978 (b), 2002 (c) and 2022 (d). san donato 1 and 2. the san donato sinkholes are in the plain to the hydrographic right of the albenga river near the settlement of the same name in the ceppaie locality, in the municipality of orbetello. although there are no mapped faults in the area, sandy-textured pliocene formations are found. there are no precise data on the formation, but it is assumed to be around the 1950s. figure 3 shows the photo collage of the site with orthophotos from 1954 (a),1978 (b), 1996 (c), 2013(d). latera. the collapse occurred between 30 and 31 january 2023 inside the vepe caldera in the municipality of latera. since the 1st of february, photogrammetric ellite systems) station consisting of a gs08 plus rover, cs10 controller and two-metre rod, connected to lieca's smartnet network. the flights were performed at an altitude of approximately 35m agl (above ground level), at a speed of 3 m/s with an estimated photographic overlap of around 75-80%. the photogrammetric process was developed using agisoft metashape professional software. in order to make more precise comparisons, the vectorized limits were projected onto the historical and recent orthophotos. to assess the effectiveness of this integrated approach, several locations in italy were selected that displayed specific indicators in the orthophotos (see results) and a geological context favourable to deep piping and suffosion phenomena. on the basis of criteria such as the availability of orthophotos, the presence of indepth stratigraphic studies, previous investigations in the area, ease of access and the possibility of carrying out photogrammetric flights in open conditions, an area in southern tuscany in the municipality of grosseto, located approximately 500 m north of the bottegone sinkhole site (coordinates wgs84 42°50’28”n, 11°03’56”e), was selected among them. to enhance our understanding of the area and allow for comparisons with findings from previous survey campaigns, the following activities were carried out: photogrammetric survey. in order to identify localised depressions in correspondence with the study area, photogrammetric surveys were carried out using the same procedure illustrated above. given the severe flight restrictions, due to the presence of the grosseto military airport, which imposed an agl altitude limit of 25m in the area in order to remain in open conditions (regulations eu 2019/947 and atm 09 circular), the flight was carried out using a dji mavic pro, at an altitude of approximately 24m, a speed of 2m/s and photographic overlap of around 70%. this survey was also georeferenced by leica gnss station. surface seismic tests. two hvsr (horizontal to vertical spectral ratio nakamura 1989) tests were carried out in the bottegone area and in the selected survey area. the hvsr method is based on the analysis of the spectral relationship between the horizontal and vertical components of the ground motion originating from environmental vibrations and recorded with a threecomponent single station. it is demonstrable (ibs-von seht et al. 1999; bonnefoy-claudet et al. 2006; lunedei et al. 2010) that the frequency corresponding to the maximum value of the hvsr function has a close correspondence with the local resonance frequency f0 of a site. the hvsr curve may have one or more peaks, caused by the presence of layers at depth both in terms of lithology and acoustic impedance. although in an approximate manner, the peak frequency values of the hvsr can be correlated with the depth of the impedances (albarello et al., 2010), thus providing an estimate of the thickness of the terrigenous deposits. the acquisitions were carried out using sara instruments' gobox instrument with 4.5 hz sensors, with a duration of 25 minutes and a frequency of 300 hz, following (sesame team, 2004). the processing was carried out using the geopsy software. rainfall data analysis. to determine the possible 91 orthophotos and geothematic knowledge for sinkhole risk mitigation. fig. 2 orthophotos of the bottegone area from 1954 (a),1978 (b), 2002 (c), 2023(d). sinkhole limit in blue. fig. 3 orthophotos of the san donato plain area from 1954 (a),1978 (b), 1996 (c), 2013(d). sinkholes limits in blue. 92 gentili f., rossi f.g. 4. results a list of clues deduced from the orthophotos of sinkholes sites was prepared: presence of slightly depressed areas with sub-circular or elliptical conformation dark colouring in orthophotos, localised and subcircular or elliptical shape localised growth of herbaceous plants with subcircular or elliptical shape presence of marsh-type ecosystems, localised and detached from the landscape presence of other sinkholes in the vicinity and small lakes, including artificial ones. selected area for field surveys. this area is located approximately 400 m north of the bottegone sinkhole, where a favourable geological context for sinkhole formation has established (nisio, 2008c; del greco et al., 2004). coordinate wgs84 42°50’27”n, 11°03’52”e. the plain is a graben, bounded by direct faults (figure 6) in the triassic formations (cavernous limestone and verrucano) with thick terrigenous deposits infilling the basin. the alluvial overburden deposits consist of silts and clays, and, subordinately, sands and gravels; the depositional environment varies from proximonitoring surveys have been carried out together with seismic, geoelectric and geochemical investigations to define the stratigraphic conditions and monitor the evolution of the phenomena over time. the sinkhole site is characterised by the presence of alluvial and eluvialcolluvial soils, resting on eruptive sequences put in place by local volcanic activity in the pleistocene. as a result of geophysical and geochemical investigations and geomorphological considerations, a structural lineament was found just at east of the sinkhole, probably due to the last caldera collapse in the late pleistocene. in particular, geochemical investigations have revealed the presence of rising fluids typical of these lineaments (puzzilli et al., 2024). in figure 4 the photo collage of the site from 2001 (a), 2017 (b), 2022 (c), 2023(d). guardia sui merti. located in the iglesiente area, this sinkhole originated in 1999. the geological context is characterised by the presence of gravelly-sandy alluvium in a clayey matrix on sandstones levels lying on a carbonate basement, located at a depth between 20 and 40 m (nisio, 2008g). approximately 900 metres to the south of the site there are more contemporary age sinkholes. in figure 5 the photo collage of the site form 1954 (a), 1978 (b), 2010 (c), 2022 (d). fig. 4 orthophotos of the latera site from 2001 (a), 2017 (b), 2022 (c), 2023(d). sinkholes limits in blue. in green the limits of the vegetation supported by piping phenomena. 93 orthophotos and geothematic knowledge for sinkhole risk mitigation. fig. 5 ortophotos of the guarda su merti area dating 1954 (a), 1978 (b), 2010 (c), 2022 (d). sinkhole limits in blue. in green, areas with pronounced plant growth/ herbaceous patches within and around the sinkhole. in brown rectangles areas outside the sinkhole showing dark colouring/pronounced plant growth. fig. 6 geological and structural map (from nisio, 2008c and del greco et al., 2004). the evidences found in orthophotos are reported with the investigations carried out. 94 gentili f., rossi f.g. hvsr. the microtremor acquisitions lasted 25 minutes each. processing was carried out using goepsy software, while the sesame criteria were checked using the hv_test tool. figure 9 shows the results at bottegone sinkhole site (fig. 9a) and at the study area site (fig. 9b). a frequency of 0.75 hz was measured at the study site, while a frequency of 0.74 hz was measured at the bottegone sinkhole. figure 10 shows the results of idw interpolations mal marine to marsh and fluvial (nisio, 2008c). the thickness of these deposits vary from 110 to 190 m as inferred from surveys (berti et al., 2002; del greco et al., 2004). cavernous limestone and verrucano formations constitute the bedrock of these deposits. the aquifer is 90-100 m deep and there are several perched aquifer systems in the sandy-gravel horizons. the shallowest aquifers are found a few metres from the surface in the area of the fattoria degli acquisti (400 m north from the site). there are minor thermal springs located along the faults, under-saturated in anhydride and over-saturated in gypsum and calcite (nisio, 2008c; berti et al., 2002). a photographic collage was also created for this site, displaying available orthophotos from 1954 to 2023 (figure 7). these images reveal dark patches consistently appearing in the same locations across various times of the year and different years. the westernmost portion, which is markedly elliptical in shape, was subjected to surface measurements using the various georeferenced orthophotos. this portion was selected because it is more visible and can be detailed in a gis environment. the results are in table 2. photogrammetric survey. the processing of the photographic images and points measured by gnss led to the production of 3d reliefs. the errors, automatically calculated by the metashape software as rms, are 0.047 m for the latera site and 0.084 m for the surface evidence study site, respectively. the orthophotos obtained from the survey (fig. 8a, reported in a gis environment on a ctr toscana 1:10000 basis), made it possible to estimate a surface area of the westernmost dark patch of approximately 8612 m2. the dtm (fig. 8b) obtained from the point cloud of the survey was used to make measurements of the microtopography affecting the area. tab. 2 surface of the dark patch. fig. 7 orthophotos of the study site (in the red rectangle): 1954 (a), 1988 (b), march 2003 (c), august 2013 (d), february 2015 (e), august 2019 (f), september 2019 (g) and march 2023 (h). to the south is located the bottegone sinkhole. 95 orthophotos and geothematic knowledge for sinkhole risk mitigation. fig. 8 a) orthophotos from a survey and b) dtm, rendered in a gis environment on a map basis. fig. 9 a) hvsr test in bottegone site. b) hvsr test in the study site. tab. 3 rainfall data. list of rainfall stations with coordinates, elevation above sea level (asl) and rainfall for the reference months. 96 gentili f., rossi f.g. marsh ecosystems, characterised by distinctly hygrophilous plants. this punctual ecosystem develops around the t-shaped drainage channels and the depression (elliptical in shape) that is clearly evident in the centre of the future sinkhole, which at various times also manifests the presence of water (fig.s 3b and 3c). the pronounced plant growth is undoubtedly supported by the increased amount of water, due to deep piping/ dipping. the incoming volumes are such as to support a marsh-like, localised and well-defined plant ecosystem in the area of the sinkhole and channel. the central depression, which can be interpreted as evidence of the deep piping/suffosion phenomena underway, appears to be the area most easily colonised by these plants, a sign of the massive presence of water probably also brought to the surface through a discontinuity system located to the east of the sinkhole (puzzilli et al., 2024). guardia sui merti. studies of the oldest orthophotos of the area (fig.s 5a and 5b) indicate areas of darker colour and sub-circular shape, widespread near the sinkhole site. such evidence is always attributable to 4. discussion the analysis of the results focused on the examination of the preand postcollapse state. temporal evolutions were examined for each site: bottegone. at this site, clear signs of depressions existing prior to 1954 were identified, probably reshaped by anthropic intervention (fig. 2a). the agricultural use of the area may have led to the complete levelling of the previous surface situation. the deep piping phenomenon, which may have contributed to the depression visible in 1954, is still active in 1978, where a darker furrow colouration, scarcely present outside the projected limits of the future sinkhole (fig. 1b), is found. this colouration can be associated with increased plant growth due to the greater availability of water, or the presence of more moisture that darkens the normal surface colour levels. the increased water supply can be directly attributed to the contribution provided by the deep piping, or to a stagnation of rainwater flowing into a local depression that can be identified as a precursor of the future sinkhole. san donato 1 and 2. in the san donato area, there are two sinkholes whose formation is uncertain in time and is generally placed before the 1950s. again, between 1954 and 1978 the northernmost sinkhole, identifiable with darker colours than the immediate surroundings (figure 3a), was partially filled in for agricultural purposes. in figure 3b, relative to the situation in 1978, despite the agricultural use, the edges of the depression can again be seen, probably due to ongoing deep piping activity. the visible evolution of this site is the anthropic transformation into an irrigation pond, which acquires an artificial quadrilateral shape (fig. 3c-3d). this functional choice is probably due to the presence of water on the surface. there is no particular evidence of evolution of the sinkhole to the south, apart from pronounced plant growth between 1954 and 1978 probably due to waterlogging. the lack of evidence, even in the most recent orthophotos, does not allow further hypotheses. latera. the latera sinkhole area, developed in a volcanic geological context, has always been used as agricultural land. from the photos of the 1940s, this vocation is clearly evident and tends to persist throughout the 20th century until the early 2000s (fig. 4a). during this period, however, more vegetation growth is noted in the area of the t-shaped drainage ditches and the future sinkhole. around 2015-2017, there is a partial abandonment of the fields and the appearance of a fig. 10 idw elaborations of data from august 2013 (a), february 2015 (b), august 2019 (c), september 2019 (d) and march 2023 (e). 97 orthophotos and geothematic knowledge for sinkhole risk mitigation. pronounced plant growth or the presence of surface moisture that darkens the natural soil colour. projecting the boundaries of the sinkhole onto the 1978 orthophoto (fig. 4b), a corresponding herbaceous patch of green color can be seen. in addition to this, there are obvious herbaceous patches to the east and north of the future sinkhole, which can also be seen on the 1954 orthophoto. this localised herbaceous growth can only be sustained by local water inputs. in this area, a sinkhole occurred in 1999, which was probably filled, also with anthropogenic input, up to the exemption (fig. 4d) today, darker coloured patches due to increased herbaceous growth are still visible, overlapping with those of 1954. this growth appears to be accentuated at the sinkhole site, probable evidence of the resumption of piping/suffosion phenomena or of a localised depression in which rainwater tends to stagnate. bottegone and the study site by analyzing a well-established geological context favorable to sinkhole formation, we were able to directly assess the practical value of insights gained from studying orthophotos in the field. to achieve this, we initially selected the area north of the bottegone sinkhole, where the orthophotos consistently indicated signs of water in the ground. the aerial images show two distinct patches that appear unified in some orthophotos. the stain further to the west is more visible than the one further to the east. the surface is stable over time, although in some photos a reduction is evident. the study of the geology of the area and the presence of other sinkhole phenomena of considerable dimensions immediately suggested that the context was favourable to the formation of sinkholes. the search for localised depressions, which could be identified as precursors of a sinkhole, involved the use of drone photogrammetry. the analysis of the dtm processed and reported in the gis environment (fig. 8b) made it possible to understand the detailed topography of the dark patches in the orthophotos. the westernmost part appears to be located on a relative high, with maximum altitudes within 3.9 m asl. eastwards, a real depression begins, which appears to be within 1.1 m elevation and then rises to elevation values of 2.1 m at the eastern limit of the relief and 1.8 m at the southern limit of the relief. the easternmost spot visible in the orthophotos is positioned in this area. the hvsr tests indicate very similar frequencies to each other, and the low values suggest deep impedances of more than 100 m (albarello et al., 2009), in agreement with the seismic tests conducted by del greco et al. (2004). therefore, in the study area, the same stratigraphic conditions found at bottegone can be hypothesized, locating the two sites on the same graben. the slight difference between the frequency value of the study area (0.75 hz) and that of bottegone (0.74 hz) suggests a declining trend of the carbonate bedrock in the ne-se direction. this hypothesis is in agreement with seismic tests and drill cores carried out in the bottegone area in 2004 (del greco et al., 2004; nisio, 2008c), which indicate a bedrook depth between 170 and 200 m, and a buried profile with a nw-se direction (fig. 11). examining the precipitation data using the idw method, it is not possible to find a direct correlation between rainfall and surface spots. this is easily verifiable by comparing the photos from august and september 2019 with the respective rainfall data. in fact, despite the scarcity of rain in august and the heavy rainfall in september (tab. 3), the spots remain always visible and with a stable surface over time. fig. 11 a) reconstructed map of hvsr surveys conducted and reflection seismic arrays by del greco et al. (2004). b) processing of the reflection test a3 by del greco et al. (2004) (from nisio, 2008c). horizontal scale 1:2000. on the right the ne end of the array and on the left the sw end. in red the carbonate bedrock, in yellow the clay deposits, in light blue the gravelly levels and in green the breccia. 98 gentili f., rossi f.g. 1978 at the site of the current bottegone sinkhole. it was not possible to carry out more in-depth studies to assess the presence of any stratigraphic anomalies attributable to cavities in formation. identifying precursor signals of sinkhole formation in alluvial plains through orthophoto analysis. by combining the information obtained from a simple comparison of orthophotos and documents relating to sinkholes in a alluvial plain context, it was possible to identify common elements that could be defined as precursor signals of sinkhole formation or, at least, of the potential occurrence of sinkholes. the extent of these signs of activity does not appear to be continuous over the years, being more evident in certain years and at certain times of the year, nor is it homogenous and easily distinguishable in all the cases examined. evidence of the presence of water in the most superficial layers of the covers, if any possibility of surface contributions is eliminated (which can be verified by comparing the period of the photo with the rainfall series at that time), can be traced back to underground activity only, and, if the presence of a favourable geological context is ascertained, can be attributed to deep piping and suffosion phenomena, which are mainly responsible for the formation of sinkholes in alluvial contexts. this approach could also be used to search for old sinkholes, the location of which is unknown, that could undergo reactivation. another application can be found in the monitoring of sinkholes that have been extinguished or filled by anthropogenic interventions, where signs of the presmoreover, the particular topography of the westernmost spot does not allow for stable and lasting water stagnation over time. additionally, the evidence is hardly linked to particular soil chroma as that land has been subjected to agricultural work for over 100 years and in the last 50 years also with heavy agricultural machinery. agricultural work would have led to the dispersion of soil with particular chromatic characteristics, leading over time to a uniform color. the spots, however, remain welldefined and with a constant surface, especially in the last 20 years. given the existence of a favorable geological context, the presence of other sinkholes in the area, a welldefined depression, and the absence of a direct correlation with precipitation, it is possible to suppose that these surface spots are due to the rise of groundwater, probably through deep piping phenomena, an evidence that was clearly visible in the orthophotos of 1954 and tab. 4 sinkhole surface. fig. 12 orthophoto of the sinkhole site at the sennes refuge in the autonomous province of bolzano from 1992(a), 2006(b), 2008(c), 2022(d). images from the bolzano autonomous province (geoportale alto adige 2024) and google earth. 99 s orthophotos and geothematic knowledge for sinkhole risk mitigation. ence of water could indicate the resumption of triggering phenomena. the observation of orthophotos, in combination with the use of historical documents (madonna et al., 2023), cartographies and the most up-to-date geological records together with data from in-sar technology (costantini et al., 2009; raspini et al., 2022), could therefore be used to identify areas, more or less vast, characterised by a predisposition to sinkholes formation. the low cost of application and the large number of orthophotos produced, especially in the last 15-20 years, makes this approach easily replicable and also usable to delineate what could be defined as areas with predisposing factors for sinkholes formation in alluvial plains. any proposed interventions in these areas should be further investigated. for illustrative purposes only, this method was also applied to a karstic sinkhole located in the bolzano autonomous province, near the sennes refuge, (wgs84 46°39'10.58"n, 12°3'29.49"e). since 1982, clear signs of the presence of a natural cavity near the refuge's structures emerged, which underwent a further collapse between 2006 and 2008, giving rise to an alpine lake. as a first adaptation of this approach to karst sinkholes, the surface area of the forementioned sinkhole was measured to monitor the evolution in each of the available orthophotos (1982, 1992, 1999, 2006, 2008, 2011, 2015, 2020, fig. 12 shows some of these) in a gis environment (tab. 4). despite the low quality of the 1982 photos, an increase in size can be detected between 1982 and 1992. the slight increase in surface area and diameter between 1992 and 1999 could be attributed to a measurement error related to the limited resolution of the available photos. between 1999 and 2006 there was another increase in surface area and the clear filling of the cavity with water. between 2008 (when the collapse had already occurred) and 2020, fluctuations in the lake level were recorded. in particular, in the orthophotos of 2015 and 2020, interpreting the darker colours as water with a greater depth, it is possible to estimate the surface area affected by the last collapse at approximately 270 m2. 5. conclusions in this article, we examined the issue of sinkholes caused by piping and suffosion, which are commonly found in recent floodplains, such as those dating back to the quaternary period. a defining characteristic of these phenomena is the rapid onset of sinkholes, which significantly heightens the associated hazards and risks, especially in areas with anthropogenic activities. with this work we introduced the application of both historical and recent orthophotos to identify clues related to the pre-collapse conditions of several sinkholes across italy. this effort has resulted in an initial list of evidence that is common to several sites, mostly related to the effects of large volumes of water being pushed near the surface by piping and suffosion processes. the use of historical and recent orthophotos in combination with geotematics knowledge of the area can provide the tools to identify vast areas with a certain level of predisposition to sinkholes. although it is not possible to attribute a real susceptibility level with orthophotos alone, it is possible, through the use of photogrammetry, geochemistry, geophysical surveys (as geoelectric and surface seismic arrays), in-sar technology and analysis of available meteorological data, to intervene in these specific areas to assess the actual level of susceptibility and identify more localized areas with an evaluable hazard level. this approach could, at least theoretically, also be applicable to sinkholes in karst environments. acknowledgements funding: this research was partially funded by pnrr-european un ion nex tgenera t ioneu mission 4 “education and research”-component 2 “from research to business”-investment 3.1 “fund for the realization of an integrated system of research and innovation infrastructures”. cup: i53c22000800006. we thank the guicciardini corsi salviati family for providing free access to the study area. references albarello d., cesi c., eulilli v., guerrini f., lunedei e., paolucci e., pileggi d., puzzilli l.m. (2010) the contribution of the ambient vibration prospecting in seismic microzoning: an example from the area damaged by the 26th april 2009 l'aquila (italy) earthquake. boll. geofis. teor. appl., 52, 3, 513538. berti g., canuti p., casagli n., micheli l., pranzini g. (2002) risultati preliminari sullo sprofondamento in località bottegone (grosseto). atti del convegno: le voragini catastrofiche, un nuovo problema per la toscana, 31 marzo 2000, gr, regione toscana, 242-256. bonnefoy-claudet s., cotton f., bard p.-y. (2006) the nature of noise wavefield and its applications for site effects studies. a literature review. earth-sci. rev., 79, 205-227. campobasso c., graciotti r., nisio s., vita l. (2004) il progetto sinkhole: le attività svolte dal dipartimento difesa del suolo dell'apat. atti del convegno: stato dell’arte sullo studio dei fenomeni di sinkholes e ruolo delle amministrazioni statali e locali nel governo del territorio, roma, 20-21 maggio 2004, 171-188. caramanna g., ciotoli g., nisio s. (2008) a review of natural sinkhole phenomena in italian plain areas. natural hazards, 45, 145-172. centamore e., nisio s., rossi d. (2009) the san vittorino sinkhole plain: relationships between bedrock structure, sinking processes, seismic events and hydrothermal springs. italian journal of geoscience, 128(3), 629-639. costantini f., fea m., nisio s., sarti f. (2009) radar interoferometry: preliminary study about sinkhole prone areas. atti del 2° workshop internazionale: gli sprofondamenti catastrofici nell’ambiente naturalizzato ed in quello antropico, roma 3-4 dicembre 2009, 967-971. del greco o., garbarino e., oggeri c., pioli f. (2004) 100 gentili f., rossi f.g. nisio s. (2008f) the sinkholes in the calabria region. mem. descr. carta geol. d’it., 85, 335-386. nisio s. (2008g) the sinkholes in the sardinia region. mem. descr. carta geol. d’it., 85, 387-398. nisio s. (2008h) the sinkholes in the ligury region. mem. descr. carta geol. d’it., 85, 399-408. nisio s. (2008i) the sinkholes in the padana plain. mem. descr. carta geol. d’it., 85, 409-418. nisio s. (2008l) the sinkholes in other regions. mem. descr. carta geol. d’it., 85, 419-426. nisio s., graciotti r., vita l. (2004) i fenomeni di sinkhole in italia: terminologia, meccanismi genetici e problematiche aperte. atti del convegno: stato dell’arte sullo studio dei fenomeni di sinkholes e ruolo delle amministrazioni statali e locali nel governo del territorio. roma 20-21 maggio 2004, 557572. nisio s., caramanna g., ciotoli g. (2007) sinkholes in italy: first results on the inventory and analysis. geological society, london, special publications 279, 23-45. noori m., hassan h., mustafa y. (2014) spatial estimation of rainfall distribution and its classification in duhok governorate using gis. journal of water resource and protection, 6, 75-82. doi: 10.4236/jwarp.2014.62012 pingel t.j., saavedra a., cobo l. (2021) deriving land and water surface elevations in the northeastern yucatán peninsula using ppk gps and uav-based structure from motion. papers in applied geography, 7(3), 294-315. doi: 10.1080/23754931.2021.1871937 puzzilli l.m., ruscito v., madonna s., gentili f., ruggiero l., ciotoli g., nisio s. (2024) natural sinkhole monitoring and characterization: the case of latera sinkhole (central italy). geosciences, 14, 18. qgis development team (2020) qgis geographic information system. version 3.16. open source geospatial foundation project. accessed 10 january 2024. https://qgis.org. raspini f., caleca f., del soldato m., festa d., confuorto p., bianchini s. (2022) review of satellite radar interferometry for subsidence analysis. earthscience reviews, 235, 7-46. romano g., capozzoli l., abate. n, de girolamo m., liso i.s., patella d., parise m. (2023) an integrated geophysical and unmanned aerial systems surveys for multi-sensory, multi-scale and multiresolution cave detection: the gravaglione site (canale di pirro polje, apulia). remote sensing, 15, 15, 382. sardegna geoportale (2024) www.sardegnageopor tale. it/. sesame team (2004) guidelines for the implementation of the h/v spectral ratio technique on ambient vibrations: measurements, processing and interpretation. (deliverable no. d23.12), wp12. sesame european research project. esame del fenomeno di subsidenza del bottegone (grosseto). atti del convegno: stato dell’arte sullo studio dei fenomeni di sinkholes e ruolo delle amministrazioni statali e locali nel governo del territorio, roma 20-21 maggio 2004. del prete s., guarino p.m., nisio s., santo a. (2008) the sinkholes in campania region. mem. descr. carta geol. d’it., 85, 149-212. geoportale alto adige (2024) geoportale.retecivica. bz.it/. geoportale nazionale (2024) pcn.minambiente.it/vie wer/. geoportale regione lazio (2024) geoportale.regio ne.lazio.it/. geoscopio (2024) www502.regione.toscana.it/geosco pio/ortofoto.html. gentili f., madonna s. (2024) photogrammetry from uav and low-cost lidar for sinkhole hazard mitigation in urban areas: applications and evaluations. geographies, 2024, 4, 343-362. doi: 10.3390/geographies4020020 google earth (2024) google.it/intl/it/earth/index.html. goovaerts p. (2012) geostatistical approaches for incorporating elevation into the spatial interpolation of rainfall. journal of hydrology, 228, 1-2, 2000, 113-129. doi: 10.1016/s0022-1694(00)00144-x ibs-von seht m., wohlenberg j. (1999) microtremor measurements used to map thickness of soft sediments. bull. seism. soc. am., 89, 250-259. igm-istituto geografico militare (2024) www.igmi.org/. liang d., gan f., zhang w., jia l. (2018) the application of hvsr method in detecting sediment thickness in karst collapse area of pearl river delta, china. environmental earth sciences, 77. doi: 10.1007/s12665-018-7439-x lunedei e., albarello d. (2010) theoretical hvsr curves from full wavefield modelling of ambient vibrations in a weakly dissipative layered earth. geophys. j. int., 181, 1093-1108. madonna s., nisio s., gentili f., vassella f., scardozzi g., romagnoli g., di nezza m., de filippo m., pelorosso m., pagano g. (2023) the role of historical-archaeological sources integrated into the gis environment with geological and geophysical data in the mitigation of geological risks in some urban areas. rend. online soc. geol. it., 61, 5057. nakamura y. (1989) a method for dynamic characteristics estimation of subsurface using microtremor on the ground surface, railway technical research institute, quarterly reports, 30, 1. nisio s. (2008a) the sinkholes: teminological problmes, genetic mechanism, classification. mem. descr. carta geol. d’it., 85, 17-32. nisio s. (2008b) the sinkholes in the lazio region. mem. descr. carta geol. d’it., 85, 33-148. nisio s. (2008c) the sinkholes in the tuscany region. mem. descr. carta geol. d’it., 85, 213-268. nisio s. (2008d) the sinkholes in the abruzzi region. mem. descr. carta geol. d’it., 85, 269-308. nisio s. (2008e) the sinkholes in the puglia region. mem. descr. carta geol. d’it., 85, 309-334. ms. received: august 8, 2024 revised: october 9, 2024 accepted: november 4, 2024 available online: november 8, 2024 101 orthophotos and geothematic knowledge for sinkhole risk mitigation. imp.bini_strini& geologia di sottosuolo dell'alta pianura a ne di milano bini alfredo1, strini andrea1, violanti donata2 & zuccoli luisa1 1dipartimento di scienze della terra, università degli studi di milano, via mangiagalli, 34, 20133 milano; alfredo.bini@unimi.it 2dipartimento di scienze della terra, università di torino, via valperga caluso 35, 10125 torino; violanti@dst.unito.it riassunto: bini a., strini a, violanti d. & zuccoli l., geologia di sottosuolo dell'alta pianura a ne di milano. (it issn 0394-3356, 2004). la ricostruzione del modello geologico del settore di alta pianura a ne di milano è stata possibile integrando i dati derivanti dal rilevamento geologico di superficie e quelli provenienti dall'analisi dei dati di sottosuolo. il rilevamento di superficie ha permesso di distinguere sia unità allostratigrafiche sia unità litostratigrafiche costituite principalmente da depositi fluviali, glaciali e fluvioglaciali di età compresa tra il pleistocene inferiore e il momento attuale. la geologia di sottosuolo è stata ricostruita mediante l'analisi dei cuttings provenienti da pozzi per acqua, di cui sono state eseguite descrizioni sedimentologiche, petrografiche e paleontologiche. questi dati sono stati integrati con stratigrafie di ulteriori pozzi esistenti di cui non è stato possibile analizzare direttamente i cuttings di perforazione. la correlazione è stata fatta mediante la redazione di sezioni rettilinee variamente orientate in modo da avere una ricostruzione tridimensionale del sottosuolo. le sezioni sono state tracciate in modo da intersecare il maggior numero di pozzi e su di esse sono stati anche proiettati i pozzi distanti non più di 300 m dalle sezioni stesse. la ricostruzione si è basata sul riconoscimento e la ricostruzione di superfici e corpi sepolti individuabili tramite descrizioni litologiche o livelli marker, la cui validità è stata verificata mediante la taratura effettuata con i cuttings e i dati del rilevamento di superficie per la porzione sommitale della successione. questa analisi ha consentito di riconoscere anche alcune unità solo sepolte (allogruppo di vimercate, allogruppo di ronco briantino, ceppo di lomagna). la ricostruzione della geologia di sottosuolo ha quindi consentito di avere una visione d'insieme dell'evoluzione della zona permettendo anche il perfezionamento dell'interpretazione della geologia di superficie in zone dove la scarsità di affioramenti rendevano dubbia l'interpretazione dei dati di rilevamento. e' stato infine redatto un modello di evoluzione paelogeografica della zona. abstract: bini a., strini a., violanti d. & zuccoli l., subsurface geology of the ne of milan high plain. (it issn 0394-3356, 2004). the geological setting of an high plain area ne of milan is carried out by the correlation among superficial data and underground ones. allo-units and litho-units have been recognised in the field relief. the units are principally composed of fluvial, glacial and glaciofluvial sediments and they have an age comprised between the lower pleistocene and the present time. in order to carry out the underground model, cuttings of water wells have been analised. the main characteristics used in cutting descripitons are: sedimentology, petrography and fossils contents. moreover, a great number of drilling logs have been considered. the correlation is carried out using rectilinear sections; these sections are oriented in various directions, so that it is possible to determine a three dimensional model of the underground structures. drills distant no more than 300 m from the sections have been projected on them. the geological reconstruction is based on the determination and the reconstruction of buried surfaces and geological bodies. these surfaces and bodies are recognised by marker or lithological descriptions that are calibrated by superficial data and cutting analysis. in this work three buried units have been recognised. they are: allogruppo di vimercate, allogruppo di ronco briantino and ceppo di lomagna. the underground model is useful to understand the geological evolution of the area. it is also useful to understand the superficial geological setting in areas in which outcrops are too distant to make a certain model. finally, a paleogeographic evolution model of the area is proposed. parole chiave: alta pianura, depositi plio pleistocenici, geologia di sottosuolo, milano, italia. keywords: high plain, plio-pleistocenic deposits, subsurface geology, milan, italy. il quaternario italian journal of quaternary sciences 17(2/1), 2004, 343-354 1. introduzione la comprensione dell'evoluzione plioquaternaria della pianura non può prescindere da una analisi della geologia di sottosuolo. infatti, come messo in evidenza da precedenti lavori (bini, 1997a; zuccoli, 1997, 2000), la ricostruzione di sottosuolo permette di individuare reticoli idrografici sepolti totalmente obliterati da eventi successivi e che testimoniano situazioni paleogeografiche completamente diverse da quelle attuali. inoltre l'analisi di sottosuolo consente di raffinare il modello derivante dal rilevamento geologico di superficie. per poter realizzare uno studio di questo tipo è però necessaria una stretta correlazione tra i dati di superficie e quelli di sottosuolo che, almeno in alcuni punti chiave, devono essere tarati tramite lo studio diretto di cuttings di perforazione o carote. in questo lavoro si presentano i risultati di uno studio di questo tipo effettuato nell'area di alta pianura a nordest di milano. 344 a. bini et al. 2. inquadramento geografico l'area studiata è collocata nell'alta pianura milanese, a ne di milano (fig. 1a), al margine delle avanzate dei ghiacciai mediopleistocenici, in particolare nella zona a cavallo tra il lobo dell'adda (a est) e il lobo del lambro (a ovest) dell'anfiteatro del lario, e comprende quindi le morene più esterne di questi lobi. l'area è caratterizzata a est dalla profonda incisione del fiume adda che taglia la successione sedimentaria per quasi 80 m in corrispondenza del ponte di paderno. internamente alla gola numerosi terrazzi testimoniano diverse fasi di riempimento e svuotamento della valle. verso ovest mancano incisioni altrettanto marcate e la zona è caratterizzata da terrazzi meno pronunciati, in genere non superiori alla decina di metri, che si chiudono verso sud isolando i lembi più alti e più vecchi della successione. 3. materiali e metodi lo studio è stato eseguito confrontando e correlando i dati provenienti dal rilevamento della geologia del quaternario di superficie e dai dati di sottosuolo, provenienti da stratigrafie di pozzi e sondaggi o dallo studio diretto di cuttings di perforazione e da spezzoni di carote. nel rilevamento di superficie sono state distinte sia unità litostratigrafiche sia allostratigrafiche secondo un criterio di rilevamento da tempo consolidato (bini, 1997b). le stratigrafie dei pozzi sono state fornite da studi privati, enti pubblici e imprese. nove pozzi ubicati nei comuni di agrate brianza, burago di molgora, ronco briantino e cornate d'adda sono stati studiati in dettaglio in alcune tesi laurea (lorito, 1997; maroni, 1994; vedrietti, 1993). i cuttings e gli spezzoni di carota sono stati analizzati dal punto di vista sedimentologico, distinguendo i livelli in base alla granulometria; sono state riconosciute le petrografie dei ciottoli delle ghiaie e dei conglomerati ed è stata prestata particolare attenzione all'eventuale contenuto paleontologico. le determinazioni dei microfossili sono state eseguite da donata violanti (università di torino), quelle relative al nannoplancton da davide castradori (agip) e quelle dei macrofossili da cesare corselli (università di milano bicocca). e' stato descritto il grado di alterazione dei ciottoli ed è stato determinato il colore della frazione fine mediante le tavole munsell. poichè i pozzi sono stati perforati per lo più a distruzione, sono andate perdute tutte le informazioni riguardo alle strutture sedimentarie quali laminazioni, gradazione o alternanze di livelli molto sottili. le sezioni sono state tracciate a scala verticale esagerata (1:1.000 in verticale, 1:25.000 in orizzontale) partendo dalla base topografica ctr (ed. 1984). sulle sezioni sono stati inseriti i dati rilevati (geologia superficiale e morfologia). le sezioni sono rettilinee, a differenza della maggior parte delle sezioni finora usate nelle ricostruzioni geologiche di questa zona, e passanti per i pozzi di maggiore interesse. i pozzi distanti non più di 300 metri dalla traccia della sezione, in zone coerenti dal punto di vista geologico, sono stati proiettati sulla sezione stessa. sono state tracciate principalmente sezioni perpendicolari e longitudinali al bacino di sedimentazione; inoltre sono state tracciate alcune sezioni oblique per poter seguire nelle tre dimensioni i corpi e le superfici riconosciuti nelle sezioni. la densità delle sezioni non è omogenea in quanto dipende strettamente dalla distribuzione dei pozzi, concentrati nelle aree di maggiore presenza industriale e abitativa (fig. 1b). le correlazioni tra i pozzi sono state eseguite partendo dai dati direttamente osservati, cioè dai dati di terreno e dai dati provenienti dall'analisi dei cuttings di perforazione, estesi poi alle stratigrafie dei pozzi adiacenti. l'analisi diretta dei cuttings di perforazione ha permesso non solo di distinguere i livelli in base alle caratteristiche tessiturali e petrografiche ma anche di evidenziare paleosuoli e profili di alterazione consentendo una migliore definizione di unità simili per sedimentologia e petrografia. nell'analisi delle stratigrafie esistenti sono stati reintepretati alcuni termini usati dai sondatori; per esempio, i livelli definiti come torba solo raramente sono effettivamente costituiti da torba, ma più generalmente sono livelli ricchi in materia organica. i livelli definiti come argilla e ciottoli, argilla rossa e argilla gialla corrispondono per lo più a unità molto alterate. sulla base di queste osservazioni è stato possibile, considerando le unità affioranti nelle adiacenze dei pozzi, tracciare in sottosuolo i limiti riconosciuti in superficie e, nel contempo, individuare anche alcune unità solo sepolte. il reticolo di sezioni ha permesso inoltre di seguire nelle tre dimensioni le geometrie dei corpi sepolti, attribuendo quindi un preciso significato geologico alle superfici riconosciute. la ricostruzione della geologia di sottosuolo, dal punto di vista evolutivo e paleogeografico, ha consentito inoltre di affinare il modello di superficie in quelle aree in cui era meno chiaro. fig. 1 a posizione dell'area di studio (in nero); b carta schematica della zona; in grigio è indicata l'estensione dei centri abitati e l'idrografia principale: le linee corrispondono alla traccia delle sezioni, i cerchi indicano i pozzi analizzati direttamente. a study area location (in black); b schematic map of the study area. grey colour shows residential areas and the main hydrography; straight lines are the geological sections, circles are the directly analysed wells. 4. geologia di superficie l'area era già stata oggetto in passato di numerosi studi (desio, 1938; riva, 1941, 1943, 1947, 1953, 1957; venzo, 1948a, 1948b, 1949, 1950) che hanno analizzato in generale l'"anfiteatro di villa d'adda". lavori più specifici su singoli aspetti sono stati rivolti alla successione affiorante nella forra dell'adda (orombelli e gnaccolini, 1978; orombelli 1979; caldara et al., 1988; giussani, 1992) oppure ai paelosuoli (ugolini e orombelli, 1968; cremaschi, 1987). bini (1994) pubblica una carta del settore orientale dell'anfiteatro dell'adda, bini e rigamonti (2000) e rossi e rigamonti (2000) analizzano la successione affiorante lungo la sponda bergamasca dell'adda. il nuovo rilevamento di superficie (strini, 2001) è riportato schematicamente in fig. 2. nella carta, a causa della scala ridotta, sono state tralasciate le unità affioranti nella forra dell'adda e il ceppo della molgora. di seguito è fornita una descrizione sintetica delle unità affioranti, mentre nelle tabelle 1, 2 e 3 sono confrontate le principali caratteristiche delle diverse unità. il termine inferiore della successione è rappresentato dalle argille di conche che affiorano sporadicamente solo nella forra dell'adda in periodi di magra. in questa unità sono raggruppati affioramenti di sabbie e limi che appartengono molto probabilmente ad ambienti diversi. sono presenti sia macrofossil i di origine marina (orombelli, com. pers.), sia livelli ricchi in sostanza organica, sia livelli fortemente screziati o arrossati. venzo (1950) rinviene in un affioramento presso paderno d'adda un dente di anancus arverniensis. poichè la successione è profondamente deformata da frane a grande scala che interessano le pareti della forra (caldara et al. 1988; giussani, 1992) e poichè gli affioramenti sono sempre di ridotte dimensioni e distanti tra loro non è possibile, di fatto, ricostruire con precisione la successione sedimentaria solo in base ai dati di superficie. superiormente alle argille di conche affiora una potente successione di conglomerati suddivisi in tre formazioni: ceppo del naviglio di paderno, ceppo del brembo e ceppo dell'adda. la divisione è resa possibile dalla marcata differenza della composizione petrografica tra le diverse unità. il ceppo del naviglio di paderno affiora nella parte settentrionale della valle dell’adda e costituisce il termine inferiore della successione; è costituito principalmente da carbonati e da arenarie calcaree provenienti dalle successioni affioranti a nord dell'area studiata. e' caratteristica la presenza di grossi blocchi di arenaria di forma subangolare (sino a 50 cm). in un affioramento, a tetto del ceppo del naviglio di paderno è presente un potente paleosuolo (spessore 250 cm) che marca il limite con il soprastante ceppo dell’adda. il ceppo del brembo si caratterizza per l'abbondante presenza di ciottoli di litologie brembane (collio, verrucano lombardo). esso costituisce il termine inferiore della successione a sud di porto d’adda ed è in parte eteropico con il ceppo del naviglio di paderno. questi conglomerati sono suturati dal ceppo dell’adda, con petrografia più variabile, che affiora lungo tutta la forra. la parte superiore del ceppo dell'adda è profon345geologia di sottosuolo ... damente alterata e costituisce una unità a sè stante denominata formazione di trezzo sull'adda. questa formazione si caratterizza per l'estrema alterazione che interessa l'intero spessore dell'unità con oltre il 90% dei ciottoli totalmente alterato. il limite inferiore è un limite graduale con formazione di organi geologici che la mette in contatto con il sottostante ceppo dell'adda. la formazione di trezzo sull’adda e il ceppo dell'adda affiorano non solo lungo l'adda, ma anche lungo alcuni corsi d'acqua minori quali il rio vallone e il rio della cavetta. il ceppo della molgora è costituito anch'esso da un conglomerato a cemento carbonatico e contenuto petrografico variabile e, sebbene sia diffusamente presente in sottosuolo, ha scarsa evidenza e continuità in affioramento. esso è presente nel settore più occidentale, lungo la molgora, il curone e corsi d'acqua minori. superiormente alla formazione di trezzo sull’adda è presente la successione dei depositi glaciali e fluvioglaciali corrispondenti alle glaciazioni medio e tardopleistoceniche. i rapporti tra le unità sono alquanto articolati a causa della complessa geometria dei due lobi dell’anfiteatro in cui si sono alternate fasi di costruzione e smantellamento. sono stati riconosciuti i depositi appartenenti a cinque unità allostratigrafiche che, dalla più antica alla più recente, sono: allogruppo del bozzente, alloformazione della specola, alloformazione di binago, allogruppo di besnate e alloformazione di cantù. queste unità corrispondono a cinque diverse glaciazioni. la loro identificazione è stata fatta in base alle fig 2 carta geologica schematica dell'area a ne di milano. schematic geological map of the area ne of milan. 346 tab. 1 sintesi delle principali caratteristiche delle principali unità affioranti (ad esclusione dei conglomerati e delle coperture loessiche). main charactherisics of the outcropping units (except conglomerates and loess). allogruppo del bozzente allogr. alloformaz. alloformaz. allogr. alloformaz. formaz. alloformaz. del ponte della di di di di c.na di c.na di specola binago besnate cantù ronchi fontana paderno . pella facies till, fluviogl. till, fluviogl. fluviogl. till, fluviogl till, fluviolg. fluviog., fluvioglaciali, fluviali versante fluviali litologia diamicton, diamicton, ghiaie ghiaie e diamicton, diamicton, ghiaie ghiaie, ghiaie, limi ghiaie sabbie ghiaie sabbie e sabbie con con interc. occasionali sabbiose intercalz. sabbiose spessore del > 10 m > 10 m non det. fino a 68 m >250 cm 4 m 1,5 m profilo alteraz. clasti alterati alterati non alterati alerati alterati** decarbonatati decabornatati carb. in superficie clasti alterati alterati occasionali arenizzati o con con cortex ridotto, con cortex o non alterati alpini arenizzati cortex rari arenizzati non alterati % clasti alterati > 90% 90%* < 10% > 70% > 90** 40% < 10% colore da 5yr da 2.5yr (occ) 10yr 7.5 yr da 7.5yr a 10yr da 7.5 yr 10yr matrice a 10yr a 10yr occas 5yr, a 10 yr 10yr argilla abbondante abbondante assente abbondante presente scarsa assente secondaria copertura -m. carmelo, 5yr, assente 10yr, 7.5yr, 10yr 10yr o assente loessica 7.5yr, 7.5yr screziato, assente 7.5yr screziato, occasionale 5yr 10yr morfologia non dà luogo ampia cerchia terrazzi interni morene morene e piane piane ampie piane fluviogl. a morfologie nella zona di alla forra conservate fluviogl. peculiari camparada dell'adda e piane fluviogl. poco conservate e piane fluvioglaciali smantellate + il profilo di alterazione è difficilmente ossorvabile a causa dell'esposizione lungo pareti abrupte. centazione da assente a buona in alcui livelli; * stima fatta sulla parte inferiore della successione a causa delle difficili condizioni di affiormento; ** affioramenti con flysch dominanti che sono tutti decarbonatati. tab 2 caratteristiche principali delle coperture loessiche. main charactheristics of loess units. monte 5yr 7.5yr 10yr 7.5 yr 10yr carmelo screziato screziato colore da 5ry a 7.5yr 5yr 7.5 yr 10yr 7.5 yr con 10yr (2.5yr occ.) screziature con glosse più arrossate e più giallatre consolidamento molto sovraconsolidato occasionalmente occasionalmente sovraconsolidato da sovraconsolidato sovraconsolidato sovraconsolidato sovraconsolidato a non sovraconsolidato contenuto abbondante abbondante presente scarsa o assente abbondante presente in argilla figure sempre presenti occasionali occasionali occasionali sempre presenti sempre presenti pedogenetiche da gelo unità a tetto alloformazione loess 7.5yr loess 10yr alloformaz. 7.5 yr,10yr 10yr più antica della specola di binago screziato unità a letto più alloformazione alloformazione alloformazione allogruppo alloformazione 7.5yr screziato giovane di c.na fontana della specola della specola di besnate della specola e m. carmelo a. bini et al. 347 caratteristiche di alterazione e alla posizione geometrica. non esistono, sul territorio analizzato, elementi per poter effettuare datazioni geocronometriche. tuttavia, correlando le unità a quelle dell’anfiteatro del lario (settore occidentale) si possono attribuire al pleistocene medio l'allogruppo del bozzente, l'alloformazione della specola e l'alloformazione di binago (bini, 1987, 1997a; zuccoli, 1997, 2000); al pleistocene mediosuperiore l'allogruppo di besnate mentre l'alloformazione di cantù corrisponde all'ultima glaciazione ed è quindi riferibile al pleistocene superiore (bini, 1997a). l’allogrupo del bozzente si caratterizza per una estrema alterazione dei clasti, un forte arrossamento e un arricchimento in argilla secondaria. l’alloformazione della specola è caratterizzata da una alterazione meno intensa, ma sempre cospicua, interessando oltre il 70% dei clasti e raggiungendo, nella zona di definizione, 8 m di spessore (zuccoli, 1997). l’alloformazione di binago e l’allogruppo di besnate hanno un'alterazione marcatamente più ridotta. l’alloformazione di cantù ha una alterazione estremamente ridotta con fronte di decarbonatazione che si attesta a una profondità di 1,5 m e l’alterazione che interessa circa il 10% dei ciottoli. tutte le unità, ad eccezione dell'alloformazione di cantù, sono coperte da una o più coltri di loess. l'allogruppo del bozzente è coperto a tetto da una caratteristica coltre di loess fortemente pedogenizzata che è stata elevata al rango di formazione denominata formazione di monte carmelo (bini, 1997a; zuccoli, 1997, 2000). nell'area sono state distinte in totale 6 coltri loessiche i cui rapporti stratigrafici non sono sempre semplici da definire. infatti l'intensa opera di sfruttamento come materia prima per l'edilizia, e la rimobilizzazione durante le fasi glaciali successive, rende gli affioramenti di loess piuttosto frammentari. 5. geologia di sottosuolo l'area è già stata oggetto di una prima ricostruzione di sottosuolo rivolta soprattutto alla caratterizzazione degli acquiferi (denti et al. 1988) mentre alcuni lavori precedenti (desio e villa, 1960; mariani, 1938) avevano considerato singole stratigrafie di pozzi. nella ricostruzione presentata in questo lavoro sono state individuate le unità già riconosciute in superficie e alcune unità solo sepolte che sono l'allogruppo di ronco briantino, l'allogruppo di vimercate e il ceppo di lomagna. i caratteri e il significato paleogeografico di queste unità sono descritte nel paragrafo successivo. la ricostruzione di sottosuolo ha permesso di individuare un reticolo di paleovalli, in parte con andamento completamente diverso dall'attuale idrografia, che è illustrato nella fig. 3. nella stessa figura è indicata la principale idrografia attuale. nella figura 4 (a,b,c) sono illustrati i rapporti stratigrafici tra le unità riconosciute in sottosuolo. tab 3 sintesi delle unità conglomeratiche affioranti. main characteristics of the conglomerates units outcropping in the area. ceppo del naviglio di paderno ceppo del brembo ceppo dell'adda ceppo della molgora carbonati 41,8% 40,8% 59,3% 49% flysch + congl. di sirone 54% 16,3% 15,4% 38,3% selce 2% 1,6% 0,7% 0,4% cristallini + metamorfici 1,4% 16,6% 18,7% 9,1% quarzo 0,2% 4,9% 2,1% 2% verrucano 0,2% 15,5% 1,5% 0,2% vulcaniti 0,4% 3,6% 2% 1,3% ultramafiti 1,7% altro 0,4% superficie erosionale, erosionale, organi geolgoci organi geologici superiore con paleosuolo cementazione buona da buona a media da buona a media da buona a scarsa fig 3 carta delle paleovalli riconosciute in sottosuolo. in grigio è indicata l'idrografia attuale. map of the paleovalleys determined by underground analisis. present hydrograpy in grey. geologia di sottosuolo ... 348 fig 4 schemi dei rapporti stratigrafici a schema dei rapporti stratigrafici orientato e-w a nord del territorio esaminato. si noti che la pelovalle 1 è indicata due volte per specificarne i rapporti con le altre unità. la paleovalle 1 è l'unica disposta e-w, mentre tutte le altre sono n-s; b schema dei rapporti stratigrafici orientato e-w a sud del territorio esaminato all'altezza di agrate brianza cavenago di brianza. si noti che l'assetto geologico è più semplice di quello a nord; c schema dei rapporti stratigrafici in un transetto n-s della zona esaminata (asse ronco briantino vimercate burago di molgora agrate brianza). si noti la differenza di età del tetto delle unità marine spostandosi da nord verso sud. bri = allogruppo di ronco briantino; cn = ceppo del naviglio di paderno; cr = ceppo del brembo; cd = ceppo dell'adda; tre = formazione di trezzo sull'adda; cm = ceppo della molgora; cl = ceppo di lomagna; bo = allogruppo del bozzente; spe = alloformazione della specola; be =allogruppo di besnate indifferenziato. stratigraphic frameworks of the area. a stratigraphic framework e-w in the northern part of the study area: note that paleovalley 1 is signed twice in order to specify the stratigraphic relationships. the paleovalle 1 is e-w oriented; all the other ones are n-s oriented. b stratigraphic framework e-w in the south part of the area at agrate brianza cavenago di brianza latitude. the geological settlement is more simple in this area than in the north one; c stratigraphic framework n-s oriented (ronco briantino vimercate burago di molgora agrate brianza axis); it is evident the different age of the top of the marine units moving from the northern part to the southern part. bri = allogruppo di ronco briantino; cn = ceppo del naviglio di paderno; cr = ceppo del brembo; cd = ceppo dell'adda; tre = formazione di trezzo sull'adda; cm = ceppo della molgora; cl = ceppo di lomagna; bo = allogruppo del bozzente; spe = alloformazione della specola; be =allogruppo di besnate indifferenziato. a. bini et al. in linea di massima si può dire che l'allogruppo di ronco briantino costituisce un insieme di unità continentali che riempiono la paleovalle 1. l'allogruppo di vimercate costituisce il riempimento di della paleovalle 3 e di parte della 4 ed è possibile distinguere al suo interno due unità, una più grossolana e una più sabbiosa. nella parte superiore di questa unità confluiscono sicuramente anche i deposti appartenenti alle facies fluvioglaciali delle unità più vecchie che non possono essere distinti in singole unità. infatti i depositi fluvioglaciali appartenenti a glaciazioni differenti possono essere distinti solo in base all'alterazione, ma in una successione sedimentaria ricostruita solo in base alle stratigrafie di pozzi o cuttings esi appariranno per lo più come un'unica sequenza di ghiaie in cui gli eventuali orizzonti di alterazione possono essere stati erosi e quindi riconosciuti solo occasionalmente. il ceppo di lomagna, che costituisce il riempimento della paleovalle 4, non è costituito da un unico evento sedimentario in quanto contiene paleosuoli, più abbondanti verso l'alto della successione. 6. ricostruzione paleogeografica la ricostruzione della geologia di sottosuolo ha permesso una prima ricostruzione dell'evoluzione paleogeografica dell'area, a partire dal pliocene superiore. osservando gli schemi dei rapporti stratigrafici si nota come la situazione sia molto articolata a nord e tenda a semplificarsi verso sud. dopo la fase di erosione messiniana, l'area era invasa da bracci di mare che penetravano profondamente nella valle del lario. a differenza dell'area a sud del lago maggiore, dove sono stati chiaramente individuati i sedimenti che testimoniano la progradazione del ticino verso la pianura durante il pliocene medio (bini, 1997a; zuccoli, 1997), nell'area interessata la sedimentazione marina continua per tutto il pliocene. l'adda percorreva la valle del ramo di como del lario al termine della quale deponeva il ceppo di portichetto del pliocene superiore (tomasi, 2001). nell'attuale valle dell'adda, oggetto del presente studio, le condizioni marine sono perdurate sino al pliocene superiore. più complessa è la situazione della valle del ramo di lecco del lario che doveva essere in qualche modo ostruito e la cui trattazione esula dagli scopi del presente lavoro. la successione sedimentaria marina appare spesso intervallata da depositi grossolani che possono essere giustificati considerando la limitata distanza dalla costa. la sedimentazione al fondo poteva quindi ricevere apporti dai versanti, da frane, da correnti di torbida o, semplicemente, dalla progradazione di torrenti che costruivano il proprio delta conoide. da condizioni marine si passa gradualmente a condizioni di laguna, in cui si depositano livelli particolarmente arricchiti in materia organica. tuttavia la mancanza di una fitta rete di pozzi e sondaggi non consente, al momento attuale, una ricostruzione più particolareggiata dell'andamento della linea di costa e dell'evoluzione del bacino. nel pliocene superiore, condizioni marcatamente continentali sono testimoniate dall'incisione nei sedimenti marini di una valle disposta e-w riempita da sedimenti fluvioglaciali, fluviali e glaciali (paleovalle 1; fig. 3). la direzione di approfondimento della valle è verso est, cioé verso l'attuale corso dell'adda. il riempimento potrebbe testimoniare una prima glaciazione correlabile in via preliminare con la glaciazione s. salvatore (bini, 1997a; zuccoli, 1997, 2000). con il pleistocene inferiore il quadro paleogeografico cambia radicalmente e la sedimentazione nell'aerea è dominata da due flussi principali, uno proveniente da nord e uno da est (fig. 5). i corsi d'acqua provenienti da nord incidono nelle unità marine una valle ben seguibile in sottosuolo che viene riempita dal ceppo del naviglio di paderno (paleovalle 2). l'andamento della valle è circa nnessw nel settore più settentrionale, piega più marcatamente verso sw tra bellusco e ornago fino all'altezza di cavenago di brianza dove la valle devia ad angolo retto verso sud. contemporaneamente, da est, un corso d'acqua proveniente dal bacino del brembo depositava una potente successione di ghiaie, ben riconoscibili in base alla petrografia. le due piane in una prima fase rimangono separate da un dosso disposto circa n-s costituito da depositi marini (argille di conche) ben individuabile in sottosuolo da colnago a roncello (fig.6). con il progredire della sedimentazione il brembo da est e i corsi d'acqua da nord colmano la paleovalle e superano l'alto in depositi marini cosicchè le due piane diventano coalescenti; l'eteropia tra le due formazioni è ipoteticamente collocabile in sottosuolo tra porto 349 fig 5 mappa schematica dell'area durante il pleistocene inferiore. le piane del ceppo del naviglio di paderno e del ceppo del brembo sono separate da un alto in unità marine. l'eteropia tra le due unità è dedotta dai dati di sottosuolo. le frecce indicano la direzione degli apporti del ceppo del naviglio di paderno (cn) e del ceppo del brembo (cr). schematic map showing the study area during the early pleistocene, deduced by ceppo del naviglio di paderno and ceppo del brembo outcrops and by underground analysis. the ceppo del naviglio di paderno plain and ceppo del brembo plain are divided by a knoll (signed with cross) composed of marine units. heteropic relationship is evident in underground analysis. arrows show the main flow direction of ceppo del naviglio di paderno (cn) and ceppo del brembo (cr). geologia di sottosuolo ... 350 fig. 6 sezione geologica all'altezza di colnago. e' evidente l'alto in unità marine che divide il ceppo del brembo (cr) dal ceppo del naviglio di paderno (cn). con il proseguire della sedimentazione le due unità superano il dosso e le due unità diventano eteropiche. cd = ceppo dell'adda, tre = formazione di trezzo sull'adda; ca = alloformazione di cantù; bps = unità di porto d'adda superiore (allogruppo di besnate); t = torba o materia organica; m = depositi marini; a = resti vegetali; b = conchiglie. geological cross section near colnago. the knoll made up of marine units divides ceppo del brembo (cr) and ceppo del naviglio di paderno (cn). when the two units reach the top of the knoll, the two units become heteropic. cd= ceppo dell'adda; tre = formazione di trezzo sull'adda; ca = alloformazione di cantù; bps = unità di porto d'adda superiore (allogruppo di besnate); t = peat or organic matter; m = marine deposits; a = vegetals remains; b = shells a. bini et al. d'adda e colnago. verso ovest la piana costituita dal ceppo del naviglio di paderno si estendeva fino a ronco briantino e villanova dove in sottosuolo è evidente la progressiva riduzione dei depositi di questa formazione. la forte eterogeneità dei depositi appartenenti al ceppo del naviglio di paderno in sottosuolo fa supporre che in realtà l'intero corpo non sia la testimonianza di un unico evento deposizionale ma risulti dalla deposizione di più corpi sedimentari deposti in condizioni diverse. la durata di questa fase non è identificabile a causa della mancanza di elementi databili nella successione, tuttavia è stata sufficiente affinché si potesse creare, almeno localmente, un paleosuolo a tetto del ceppo del naviglio di paderno. su una paleosuperfice probabilmente molto articolata, costituita dalle due piane coalescenti, si depone un nuovo corpo di ghiaie che oblitera completamente la topografia precedente e che si espande per una superficie considerevole, dall'adda fino ronco briantino e carnate a ovest e da paderno d'adda fino all'autostrada mi-ve per spingersi ancora più sud dell'area rilevata. questi depositi, costituenti il ceppo dell'adda, testimoniano un corso d'acqua di notevoli dimensioni proveniente da nord (fig. 7). questo conglomerato era stato attribuito precedentemente al dominio valsassinese (orombelli, 1979), tuttavia il rilevamento geologico di tutto l'anfiteatro del lario, lo spessore, l'estensione e la petrografia del conglomerato indicano che il ceppo dell'adda costituisce l'espressione sedimentaria dell'adda. la diversione dell'adda da como a lecco avviene durante i l pleistocene inferiore. allo stato attuale delle ricerche non è possibile stabilire se la diversione sia dovuta a tettonica, a semplice dinamica fluviale o ad una glaciazione. la successione costituita dal ceppo dell'adda e dalle sottostanti unità è successivamente tagliata da una valle (paleovalle 3) che disarticola la superficie originaria (figg. 3 e 8). la paleovalle 3 inizia dal versante dell’attuale valle dell’adda (giussani, 1992), ha un andamento circa ne-sw nel tratto più a monte e piega in modo deciso verso sud in corrispondenza dell'abitato di vimercate. questo andamento ricalca in parte quello della paleovalle 2. una seconda paleovalle (4) si imposta più a ovest della precedente. la valle, tagliata direttamente nei depostiti marini, ha un andamento n-s nel tratto più settentrionale, dove ricalca l'attuale corso della molgora, mentre in corrispondenza di vimercate cambia di direzione verso sw per poi disporsi parallelamente alla paleovalle 3. i talweg delle due paleovalli restano separati sino alla loro confluenza all’altezza di caponago. le valli 3 e 4 testimoniano un fenomeno erosivo di portata considerevole, se si considera che all'altezza dell'abitato di bernareggio la differenza di quota tra il talweg e il top dei versanti della paleovalle 3 è di quasi 100 m. la forma della paleovalle 3 mostra, in destra idrografica, un ampio semicerchio (fig. 3). in corrispondenza di questo e a ovest del talweg, il fondovalle costituisce un ripiano sul quale insistono corpi di conglomerati via via più spessi andando in direzione del piastrone di ceppo dell'adda (fig. 8). questi depositi possono essere interpretati come corpi di frana, in analogia con quanto attualmente visibile nella forra dell'adda (caldara et al., 1988) dove la successione è dislocata da imponenti fenomeni di rilascio. i riempimenti delle paleovalli 3 e 4 presentano molte analogie. in una prima fase la paleovalle 3 è percorsa da corsi d'acqua a energia elevata, che depongono sedimenti grossolani costituenti la porzione inferiore dell'allogruppo di vimercate. l'energia di questi corsi d'acqua diminuisce verso sud come è testimoniato dal ridotto spessore di questi depositi. successivamente e contemporaneamente al progressivo colmamento della valle l'energia dei corsi d'acqua si riduce a tal punto che si instaurano sempre più spesso specchi d'acqua stagnante, con deposizione di livelli fini ricchi in materia organica. con il progredire della sedimentazione viene superato l'alto topografico che separava le valli 3 e 4 cosicchè i corsi d'acqua della palevoalle 3 possono divagare anche nella paleovalle 4, che era stata riempita dai depositi grossolani del ceppo di lomagna, e che, in questa fase, non è più attiva e non presenta più apporti da nord. successivamente le valli vengono nuovamente percorse da corsi d'acqua a elevata energia che trasportano i sedimenti grossolani, oggi costituenti il ceppo della molgora, parzialmente affiorante presso aicurzio, vimercate, cernusco lombardone e in altre località. in questo conglomerato sono presenti sia corpi con clasti di litologie locali, sia corpi con clasti di litologie cristalline. il corso d'acqua che scorreva nella paleovalle 4 depositava ghiaie di composizione strettamente locale provenienti, almeno in parte, dal bacino del curone. gli apporti con marcato incremento di litologie esotiche, dato che il ceppo della molgora è successivo ai primi eventi glaciali, possono essere attribuiti al rima351 fig. 7 carta schematica della piana del paleo adda, dedotta dagli affioramente del ceppo dell'adda, della formazione di trezzo sull'adda e dai dati di sottosuolo. cd = ceppo dell'adda. le frecce indicano la direzione principale degli apporti. schematic map of the paleo adda plain, deduced from ceppo dell'adda and formazione di trezzo outcrops and underground analyses. cd = ceppo dell'adda. arrows show the main flow direction. geologia di sottosuolo ... neggiamento di precedenti sedimenti glaciali o fluvioglaciali. con il pleistocene medio le condizioni cambiano in modo radicale in quanto il territorio è interessato dalle avanzate glaciali di cui rimangono ampie tracce in superficie. le prime grandi avanzate glaciali depositano i sedimenti oggi compresi nell'allogruppo del bozzente in cui si individuano almeno due fasi maggiori (bini, 1997a; zuccoli 1997, 2000). la prima fase di avanzata glaciale (formazione di c.na ronchi pella) arrivava a lambire l'abitato di usmate -velate; uno scaricatore glaciale doveva percorrere la paleovalle 5 disposta circa n-s e ben evidente da lomagna a carnate. le morene relative a questa fase sono state in seguito smantellate e oggi la formazione di c.na ronchi pella è individuabile solo in sporadici affioramenti. il successivo evento glaciale (glaciazione c.na fontana, i cui depositi sono raggruppati insieme alla f. di c.na ronchi pella nell'allogruppo del bozzente) raggiungeva in pratica il limite della glaciazione precedente, costruendo l'imponente cerchia di camparada a ovest e una cerchia, oggi smantellata, a est. di quest'ultima rimane evidente il dosso di bernareggio mentre verso est la cerchia si chiudeva probabilmente poco a nord di cornate d'adda. antistante alla cerchia di camparada si estendeva un'ampia piana fluvioglaciale, oggi smembrata e testimoniata da terrazzi che si chiudono all'altezza di arcore. più a est, nel lobo dell'adda si instaurava una piana fluvioglaciale testimoniata da superfici terrazzate a sud degli abitati di bernareggio e carnate; le acque fluvioglaciali sfruttavano in parte la paleovalle 3 ormai 352 fig. 8 sezione geologica tra usmate e castel negrino; sono evidenti le palevalli 3 e 4. il profilo della paleovalle 3 mostra un'ampia spianata sulla quale si impostano corpi di conglomerato intepretati come il prodotto di frane alla grande scala lungo i versanti della paleovalle. le sigle delle unità sono le medesime della fig. 5. bor = formazione di c.na ronchi pella; bof = alloformazione di c.na fontana bce = unità di cernusco lombardone; bos = unità di osnago; t = torba o materia organica; a = resti vegetali; b = conchiglie. cross section from usmate to castel negrino; paleovalleys 3 and 4 are evident. note that the paleovalle 3 profile has a wide terrace on which conglomerates bodies are present. the conglomerates are intrepreted as the effect of great landslide along the paleovalley slope. the unit abbreviations are the same of fig. 5. bor = formazione di c.na ronchi pella; bof = alloformazione di c.na fontana bce = unità di cernusco lombardone; bos = unità di osnago; t = peat or organic matter; a = vegetals remains; b = shells. a. bini et al. quasi totalmente riempita mentre ancora più a est, lungo l'allineamento castel negrino cornate d'adda, la precedente superficie topografica costituita dalla formazione di trezzo sull'adda rimaneva preservata dall'erosione, in prossimità di castel negrino, da un terrazzo vergente a nord. uno scaricatore glaciale minore doveva sfruttare l'incisione del rio vallone. le glaciazioni successive hanno costruito morene interne alle precedenti, ancora conservate nel lobo del lambro e totalmente smantellate (per quanto riguarda l'alloformazione della specola e l'alloformazione di binago) nel lobo dell'adda. durante la glaciazione specola un'ampia valle fluvioglaciale disposta nne-ssw si impostava tra bernareggio, aicurzio e bellusco; dallo stesso lobo uno scaricatore di minore portata sfruttava la già esistente valle del rio vallone. dal lobo del lambro, invece, uno scaricatore sfruttava una valle posta a ne di usmate velate. le due piane si univano appena a nord di vimercate, costituendo così un unico sandur di vaste dimensioni. alla glaciazione specola o binago possono essere attribuite anche le ghiaie dell'allogruppo del ponte di paderno che costituiscono corpi interni alla forra dell'adda, in parte cementati e coperti dai successivi depositi dell'allogruppo di besnate. sono attribuiti alla glaciazione binago alcuni affioramenti lungo il rio vallone, che doveva quindi funzionare da scaricatore glaciale, e un grosso terrazzo posto tra concorezzo e vimercate che sottende depositi marcatamente arricchiti in litologie locali. la glaciazione besnate è invece molto più articolata in quanto consta di numerose fasi, ognuna delle quali ha dato luogo a morene e terrazzi variamente giustapposti che sulla carta di fig. 2 sono stati tutti raggruppati nell'allogruppo di besnate indistinto. e' da notare che sia nel lobo del lambro sia in quello dell'adda le morene relative a questa fase si attestano a nord dell'area studiata e, a partire dall'ultima unità dell'allogruppo, uno scaricatore usava la valle dell'adda, tagliando l'alimentazione al rio vallone. allo stesso modo la glaciazione cantù è rappresentata solo da deposti fluvioglaciali che nel lobo dell'adda costituiscono terrazzi interni alla forra e piccole piane a nord di cornate d'adda, mentre nel lobo del lambro (almeno per quanto riguarda il settore in esame) sono limitati a piccoli terrazzi lungo il corso della molgora. l'area a sudovest, come si evidenzia anche dagli schemi dei rapporti stratigrafici, è molto meno articolata. essa è interessata solo dall'incisione delle paleovalli 3 e 4 e da una valle (paleovalle 6) con direzione nw-se. quest'ultima valle è riempita da depositi fluvioglaciali indistinguibili, che comprendono tutta la serie che va dall'allogruppo del bozzente alle prime unità dell'allogruppo di besnate ed è interpretabile in prima approssimazione come un paleoalveo del lambro che scorre attualmente ad appena 2 chilometri di distanza. nello figura 4c è evidente come il tetto dei sedimenti marini si abbassi verso sud e che in questa direzione sia di età più recente rispetto alle aree a nord. questa disposizione è dovuta alla subsidenza della pianura, al sollevamento isostatico della catena e probabilmente anche a tettonica. 7. conclusioni tramite la stretta integrazione tra i dati provenienti dal rilevamento di superficie, dall'analisi di cuttings di perforazione e carote e dalle stratigrafie di pozzi per acqua, è stato possibile ricostruire un modello di sottosuolo dell'area a ne di milano. questo modello supera il tradizionale limite delle ricostruzione di sottosuolo in quanto le correlazioni tra i pozzi non vengono effettuate solo in base alla litologia, ma sono distinti corpi geologici e superfici, riconoscibili grazie al confronto con i dati di superficie. oltre al tracciamento in sottosuolo dei limiti riconosciuti in superficie è stato possibile determinare alcune unità solo sepolte. il lavoro ha permesso di ricostruire un reticolo di valli sepolte oggi totalmente colmato. la definizione delle geometrie dei corpi sepolti inoltre può essere il primo passo verso un migliore e più dettagliato modello idrogeologico, in quanto i limiti tra unità geologiche che spesso hanno diverse caratteristiche idrauliche condizionano la circolazione di acqua nel sottosuolo. la mancanza di una omogenea distribuzione dei pozzi fa si che il modello oggi proposto possa essere migliorato in futuro qualora fossero disponibili ulteriori dati. 8. ringraziamenti si ringraziano tutte le imprese, gli enti e gli studi professionali che hanno messo ha disposizione i campioni e i dati. si vogliono ringraziare in particolar modo il prof. corselli per la determinazione dei macrofossili e davide castradori (agip) per la determinazione del nannoplancton. si ringrazia altresì il dott. peterlongo del c.a.p., il dott. giussani della montedison e il dott. ghezzi dello studio geotecnico associato. 9. bibliografia bini a. (1994) carta geologica dell’apparato glaciale dell’adda (sponda bergamasca) tavola esterna allegata a: cremaschi m., bini a., ferliga c., marchetti m., ravazzi c. e rossi s., 1994: montagna e pianura: i processi geologici recenti e gli effetti sull'ambiente. in: storia economica e sociale di bergamo: i caratteri originali della bergamasca. fondazione per la storia economica e sociale di bergamo. istituto di studi e ricerche. bini a. (1997)a stratigraphy, chronology and palaeogeography of quaternary deposits of the area between the ticino and olona rivers (italyswitzerland). southern alps quaternary geology, igcp 378 meeting, lugano ottobre 1995 geologia insubrica 2 (2), pp. 21-46. bini a., (1997)b problems and methodologies in the study of quaternary deposits of the southern side of the alps. southern alps quaternary geology, igcp 378 meeting, lugano ottobre 1995 geologia insubrica 2 (2), pp. 11-20. bini a. & rigamonti i. (2000) le unità lito e allostratigrafiche dei depositi superficiali. 3.8 il bacino 353geologia di sottosuolo ... dell’adda in: carta geologica della provincia di bergamo, scala 1:50.000 e relative note illustrative, pp. 214-237. provincia di bergamo. caldara m., cancelli a. & giussani a. (1988) the adda canyon, south of lecco: an example of landslide induced morphology. in: bonnard c.: landslides glissements de terrain. proceedings of the fifth international symposium on landslides 10-15 july1988, losanna, vol 1, pp. 89-94. cremaschi m. (1987) paleosol and vetusols in the central po plain (northen italy) a study in quaternary geology and soil developement. unicopoli, milano. denti e., francani v., fumagalli l., pezzera g. & sala p. (1988) studio idrogeologico del foglio vimercate igm 1:50.000 studi idrogeologici sulla pianura padana, 4, pp 2-39. desio a. (1938) caratteri fisici e geologici della provincia di milano. ann. sperim. agraria, 32, pp. 3 47. desio a. & villa f. (1960) stratigrafie dei pozzi per acqua della pianura padana. 1-lombardia universita` di milano. ist. di geologia, 370 pp. giussani a. (1992) movimenti franosi profondi e superficiali lungo il naviglio di paderno (f.adda, lombardia) studi trentini di scienze naturali, 68 (1990), pp. 1-24. lorito r. (1997) analisi sedimentologica e paleontologica di alcuni sondaggi eseguiti a cornate d’adda (mi) tesi di laurea inedita. università degli studi di milano. mariani e. (1928) il pliocene del sottosuolo di monza e vimercate (lombardia) atti soc. it. sc. nat., 67, pp. 136-143. maroni m. (1994) studio della stratigrafia di alcuni pozzi profondi nella zona di agrate brianza, brugherio e burago molgora. tesi di laurea inedita. università degli studi di milano. orombelli g. (1979) il ceppo dell’adda: revisione stratigrafica riv. ital. paleont., 85 (2), pp. 573 652. orombelli g. & gnaccolini m. (1978) composizione petrografica e provenienza del "ceppo" di paderno d’adda gruppo di studio quatern. padano, quaderno 4, pp. 7 30. riva a. (1941) notizie sul glaciale della brianza boll. soc. geol. it. 60 (1), pp. 50-64. riva a. (1943) il morenico antico in brianza boll. comit. glac. it., 22, (1942), pp. 1 6. riva a. (1947) commento alla carta geomorfologica 1:30.000 dell’apparato morenico dell’adda di lecco di sergio venzo boll. soc. geol. it., 66, pp. 22-24. riva a. (1953) stato attuale dello studio del quaternario del territorio a sud del lario e compreso tra l`adda e l`olona, fino alla latitudine di monza la ricerca scientifica, 23 (2), pp. 226 231. riva a. (1957) gli anfiteatri morenici a sud del lario e le pianure diluviali tra adda e olona atti ist. geol. univ. pavia, 7, pp. 5 95. rossi s. & rigamonti i. (2000) le unità lito e allostratigrafiche dei depositi superficiali. 3.7 il bacino del brembo: in: carta geologica della provincia di bergamo, scala 1:50.000 e relative note illustrative, pp.179-214. provincia di bergamo. strini a. (2001) gli occhi polini della brianza orientale. genesi ed evoluzione del fenomeno nel quadro geologico regionale tesi di dottorato di ricerca, università degli studi di milano, 550 pp. tomasi f., 2001 i depositi plioquaternari tra la valle del torrente lure e la valle del torrente seveso (co) tesi di laurea inedita, università degli studi di milano. ugolinif. & orombelli g. (1968) notizie preliminari sulle caratteristiche pedologiche dei depositi glacial i e f luvioglacial i fra l'adda e l'olona in lombardia rend. ist. lomb. sc. lett., a 102, pp. 767 799. vedrietti f. (1993) analisi stratigrafica di due pozzi situati nel comune di ronco briantino tesi di laurea inedita. università degli studi di milano. venzo s. (1948)a rilevamento geomorfologico dell’apparato morenico dell’adda di lecco atti soc. it. sc. nat., lxxxvii (1947) (1-2), pp. 79 140. venzo s. (1948)b la serie quaternaria dell’apparato morenico dell’adda di lecco comparata col diagramma di milankovitch boll. soc. geol. it., 56 (1947), pp. 82 83. venzo s. (1949) risposta al commento di riva sulla mia carta geomorfologica dell’apparato morenico dell’adda. osservazioni sulla carta geomorfologica tra il canturino e la brianza occidentale, 1949, del dott. arturo riva boll. soc. geol. it., 68, pp. 58 65. venzo s. (1950) rinvenimento di anancus arvernensis nel villafranchiano dell’adda di paderno, di archidiskodon meridionalis e cervus a leffe. stratigrafia e clima del vil lafranchiano bergamasco atti soc. it. sc. nat., 89 (1/2), pp. 43 122. zuccoli l. (1997) geologia dell’alta pianura lombarda tra i pianalti di castelseprio e tradate appiano gentile tesi di dottorato di ricerca, università degli studi di milano, 453 pp. zuccoli l. (2000) geologia dei pianalti di castelseprio e tradate (provincia di varese) il quaternario, italian journal of quaternary science, 13, pp. 5780. 354 ms. ricevuto l’11 maggio 2004 testo definitivo ricevuto il 2 novembre 2004 ms. received: may 11, 2004 final text received: november 2, 2004. a. bini et al. sess 0_retro e indice edi.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 dynamics of the western mediterranean mammalian fauna during the.quaternary maria rita palombo dipartimento di scienze della terra, universita` ‘‘sapienza’’, roma cnrigag, roma, italy corresponding author: m.r. palombo <mariarita.palombo@uniroma1.it> abstract: palombo m.r., dynamics of the western mediterranean mammalian fauna during the quaternary. (it issn 0394-3356, 2011) during the quaternary, the dispersal in the north-western mediterranean regions of several mammalian taxa modified the structure of pre-existing faunas, altering the internal equilibrium of palaeocommunities, perhaps removing keystone species and giving rise to new inter-guild and intra-guild dynamics. diachroneity in local turnovers across the western mediterranean regions, probably relied on differences in local dynamic patterns, thought the different manifestations of global climate changes in different geographic settings could have contributed to the scale of local bioevents. riassunto: palombo m.r, dinamica delle faune a grandi mammiferi del mediterraneo occidentale durante il quaternario. (it issn 0394-3356, 2011) nel corso del quaternario, la dispersione nel mediterraneo nordoccidentale di vari grandi mammiferi modificò la composizione e la struttura delle faune preesistenti, alterando l’equilibrio delle “paleocomunità”, a volte rimuovendo specie chiave, e dando origine a nuove dinamiche di competizione/coevoluzione tra e nell’ambito dei diversi gruppi ecologici. la diacronia nel rinnovo faunistico, sia tassonomico che funzionale, osservata tra le diverse regioni (spagna, francia, italia), è da imputarsi a diversità nella dinamica biotica locale, anche se fattori geografici hanno indubbiamente favorito variazioni locali nel manifestarsi degli effetti dei cambiamenti globali del clima. key words: large mammals, spain, france, italy, quaternary, diversity, turnover parole chiave: grandi mammiferi, spagna, francia, italia, quaternario, diversità, rinnovi faunistici 1. introduction during the quaternary, earth’s climate underwent a significant evolution: climatic oscillations were a recurring phenomenon, and took place on different temporal and geographic scales. throughout the pliocene–pleistocene, large mammals, particularly from middle latitudes, are known to have more frequently reacted to climate shifts, not by evolving and producing new species, but by varying their range. this, in keeping with the vegetational cover and latitudinal displacement of biomes, as well as with changes in palaeogeographical setting, relate to both tectonics and climate forcing . many evolutional stages have been recognized in a number of phylogenetic mammal lineages, and a number of sequences of ecological and dispersal events have been seen as developing on a backdrop of a complex interplay of palaeogeographic reorganizations and climatic factors. therefore, physical environmental modifications have often been regarded as the main factors in determining concurrent bioevents in multiple lineages, which in turn affected the taxonomic diversity and changed the structure of palaeocommunities. although global climatic changes undoubtedly altered existing habitats, giving rise to new environments for both indigenous and dispersing species, the evolutionary dynamics of mammalian fauna are actually a high complex phenomenon. therefore, it seems reasonable to suppose that both climate and intrinsic biotic controls could have contributed to regulate the composition and structure of regional faunas, albeit at a different temporal scale (see barnoski, 2005; palombo, 2007, 2010 and reference there in). 2.source of data the data base consists of taxonomically revised lists of large mammal species from selected spanish, french and italian local faunal assemblages (lfas, i.e., a list of the species identified from the remains retrieved at a given fossil site, and recovered from the same stratigraphic horizon) ranging in age from the early to the middle pleistocene (middle villafranchian to early aurelian european land mammal ages, elmas). the lists have been compiled from previous analysis on the pliopleistocene mammals of the north-western mediterranean region (see palombo 2007, 2010 and references therein) adding some recently discovered and/or revised faunas (e.g. pastre, 2009; bovin et al. 2010; martinez et al., 2010; toro et al., 2010; palombo & milli in press). 152 154 153 ta bl e 1, in te gr at ed c hr on ol og ic al s ch em e an d tre nd s of fa un al re ne w al , o rig in at io n an d ex tin ct io n ra te s an d ta xo no m ic d iv er si ty in th e w es te rn m ed ite rra ne an ( * ) , s pa ni sh ( + ), fr en ch ( x ) a nd it al ia n ( o ) fa un al c om pl ex es . s ch em a cr on ol og ic o in te gr at o ed a nd am en to d eg li in di ci d i r in no vo fa un is tic o, d ei ta ss i d i c om pa rs a e sc om pa rs a e de lle d iv er si tà n ei c om pl es si fa un is tic i d el la s pa gn a ( + ), fr an ci a ( x ), it al ia ( o ) e de l m ed ite rr an eo o cc id en ta le n el s uo in si em e ( * ). dynamics of the western mediterranean mammalian 154 ms. received: testo ricevuto il 3. diversity and turnover dispersal events likely modified the structure of the pre-existing mammalian faunas, merging previously independently evolved taxa into new palaeocommunities, leading to dynamic shifts in community structure and promoting biotic and functional turnovers. as a result, dispersal events undoubtedly contributed to regulate both regional and local faunal renewals as well as diversity trends. diversity itself is indeed regulated by the opposing forces of extinction and origination, the latter actually depending on both in situ evolution of new species, and dispersal of taxa from adjacent areas. this is because of the extension of their range, promoted by either environmental changes or disappearance of ecological/ geographical barriers. accordingly, the study of the nature of turnover (e.g. comparing each other the perdispersal and per-origination indexes, see below) as well as of trends in faunal diversity, is an important aspect of evolutionary biology. understanding diversity and turnover dynamics through time and space, has important implications in correctly assessing the influence of both climate changes and intrinsic biotic factors on the evolution of mammal fauna. herein, taxonomical diversity was estimated as “estimated mean standing diversity” (nsd) as in foote (2000). faunal renewal was estimated both as a change in the taxonomic composition at the transition between two faunal complexes belonging two successive biochrons (turnover index), as well as by the number of taxa which appeared/ disappeared during the time slice of a single biochron (origination and extinction rates). three turnover indexes were calculated: the global “per dispersal” (ti-m) and the “per speciation” (tio) turnover index (ti-g) as in palombo (2010). origination (or) and extinction (er) rates within each biochron were calculated following foote (2000). main results are summarized in table 1. 4. remarks the main bioevents in the dispersal of taxa of both african and asian origin, were mostly triggered by major global climatic changes (noticeably cold-shift oscillations around 2.6 and 1.0 ma), to which large mammals more frequently reacted, not by evolving and producing new species, but by varying their range, in keeping with the vegetation cover and latitudinal displacement of biomes. over time, the appearance of such newcomers in the northwestern mediterranean regions modified the structure of the pre-existing mammalian faunas, altering the internal equilibrium of palaeocommunities, perhaps removing keystone species and giving rise to new inter-guild and intra-guild dynamics. diachroneity in local turnover across the northwestern mediterranean regions, probably have relied on the differences in local dynamic patterns of competition/coevolution, even if the different manifestations of global climate changes in different geographic settings could have contributed to the scale of local bioevents. references barnosky a.d. (2005) effects of quaternary climatic change on speciation in mammals. journal of mammalian evolution, 12 (1,2), 247-264. boivin p., barbet p., boeuf o., devouard b., besson j-c., hénot j-m., devida, j-l. & constantin c. (2010) geological setting of the lower pleistocene fossil deposits of chilhac (haute loire, france). quaternary international, 223-224, 107-115. foote m. (2000) origination and extinction components of taxonomic diversity: general problems. paleobiology, 26 (suppl.), 74–102. martínez k., garcia j., carbonel e., agustí j., bahain j-j., blain h-a., burjachs f., cáceres i., duval m., falguères c., gómez m. & huguet r. (2010) a new lower pleistocene archeological site in europe (vallparadís, barcelona, spain). pnas, 107 (13), 62567. palombo m.r (2007) which boundary for the quaternary period and pleistocene epoch? the contribution to the debate given by turnover patterns in large mammalian complexes from north-western mediterranean region. quaternaire, 18, 35-53. palombo m.r. (2010) a scenario of human dispersal in the northwestern mediterranean throughout the early to middle pleistocene. quaternary international, 223-224, 179-194. palombo m.r. & milli s. (2010) mammalian fossil recod, depositional setting, and sequence stratigraphy in the middle – upper pleistocene of roman basin. il quaternario, 24 (2), 257-262 pastre p.a. (ed.) (2009) biochronologie et grands mammifères au pléistocène moyen et supérieur en europe occidentale. quaternaire, 20 (4). toro i., martinez-navarro b. & agusti j. (eds) (2010) occupaciones humanas en el pleistoceno inferior y medio de la cuenca de guadix-baza. monografias archeologia. junta de la andalusia, 582. january 15, 2011 15 gennaio 2011 sess 0_retro e indice edi.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 ms. received: testo ricevuto il the marine isotopic stages (mis) 13–9 represent an extraordinarily time interval (between ~300 and ~500ka) for investigating the baseline natural climate changes. this period has been considered by the scientific community an unusually warm interval during the last 1000 ka. in particular mis11 represents the first interglacial after the mid-brunhes carbon-cycle event with atmospheric greenhouse gases concentrations and temperatures similar to the today interglacial phase. these knowledges are crucial in order to understand the present climatic variability and to predict its possible future evolution. in this framework, we present the new high-resolution planktonic foraminiferal data throughout mis 13-9 on the sediment core kc01b collected in the ionian basin (eastern mediterranean sea) at 3643 m water depth. this deep marine record represents a key site for the construction of a sapropel-based astronomical timescale for the last 1.1 my (lourens, 2004) in the mediterranean sea and contains an high number of tephra layers. this study is based on quantitative analysis of planktonic foraminifera with a time resolution of about 380 kyr. the constructed planktonic foraminiferal paleoclimatic curve of the investigated time interval documents different climate patterns during the interglacials mis 13, 11 and 9 in terms of intensity and internal variability. in addition, the distributional trend of globigerinoides ruber group, turborotalia quinqueloba and globigerina bulloides suggests important changes in productivity and stratifications induced by a strong linkage between climate variability and hydrographic conditions. references lourens l.j. (2004) revised tuning of ocean drilling program site 964 and kc01b mediterranean) and implications for the δ18o, tephra, calcareous nannofossil, and geomagnetic reversal chronologies of the past 1.1 myr: paleoceanography, 19, pa3010. doi: 10. 1029 / 2003 pa000997. variability in the ionian sea (core kc01b) during mis 9-13 evidenced by planktonic foraminiferal assemblages lirer f.1, afferri a.2, bergami c.3, capotondi l.3, de lange g.4, ferraro l.1, foresi l.m.5, girone a.2, lourens l.6, vallefuoco m.1 & verducci m.6 1 istituto ambiente marino costiero (iamc) – cnr, sede di napoli 2 dipartimento di geologia e geodesia, università di bari 3 istituto di scienze marine (ismar)cnr, sede di bologna 4 department of earth sciences, geochemistry faculty of geosciences, utrecht university 5 dipartimento di scienze della terra, università di siena 6 department of earth sciences, faculty of geosciences, utrecht university corresponding author: f. lirer <fabrizio.lirer@iamc.cnr.it> abstract: lirer f. et al, high resolution climate variability in the ionian sea (core kc01b) during mis 9-13 evidenced by planktonic foraminiferal assemblages (it issn 0394-3356, 2011) riassunto: lirer f. et al, variazioni climatiche ad alta risoluzione nel mar ionio (carota kc01b) durante i mis 9-13 riconosciute attraverso le oscillazioni dei foraminiferi planctonici (it issn 0394-3356, 2011) key words: planktonic foraminifera, eastern mediterranean, paleoclimate parole chiave: foraminiferi planktonici, mediterraneo orientale, paleoclima 211 january 13, 2011 13 gennaio 2011 213 anni per ii corso di geologia, sembrava si volesse dare un'ampia autonomia a livello locale, che poteva portare a dare risposte soddi­ sfacenti alla domanda di piu ampia formazione in campo geologico applicativo ed ambientale , dall 'altro venivano bocciate pretestuo­ samente proposte di nuovi indirizzi applicativi tra cui quello della "geologia per l'ambiente e ii territorio" di cagliari dove pure esistevano precise competenze come la ldrogeologia, la geologia ambientale, la geomorfologia e la geopedologia. credo che nel prossimo futuro vi sara bisogno di un forte impegno comune e di altre iniziative come questa per assicurare alla geologia per l'ambiente quel ruolo fondamentale che merita nella conoscenza, nella pianificazione e nella gestione del territorio. professor ippolito: grazie dottor di gregorio che cos/ ci ha spiegato pure questa nuova associazione, che cosa fa e che cosa si ripromette, e questo, siccome non lo sapeva nessuno e mo/to utile. darei la para/a al professor mancini. prende la para/a ii prof. f. mancini (universita di firenze, presidente def comitato 04 cun): lllustre e caro presidente, voglio ringraziare molto gli organizzatori di questo convegno per l'invito rivoltomi. mi hanno qui qualificato come presidente del cun 04, e in tale veste vi tediero per un solo minuto con le melanconiche vicissitudini di tale organismo. leggo qualche riga di una let­ tera, ben piu lunga e circonstanziata, che noi abbiamo mandato al neo-ministro umberto colombo che sui problemi della geologia per la verita si e piu volte soffermato. scrivevamo: "la grave situazione venutasi a creare a seguito della contemporanea riduzione dei fondi da un lato e dalla introduzione di vincoli, giustamente piu restrittivi , sui criteri di finanziamento della ricerca dall 'altro, comportano di fatto la soppressione di progetti scientificamente validi e di forte impatto nazionale." gia lo scorso anno ii comitato aveva denunciato al ministro ruberti lo stato di grave disagio dei cultori di scienze della terra, conseguente al progressivo impauperamento delle risorse finanziarie, ricevendo ampie assicurazioni di un suo personale interessa­ mento, in quanto presidente del cun, per un recupero del ruolo del settore . ruberti ci aveva addirittura suggerito di preparare, insie­ me al comitato cnr 05, una commissione che si sarebbe dovuta adoperare per la realizzazione di un piano di settore. la lettera conclude cos1 : "poiche a tutt'oggi non c'e stato alcun seguito alla richiesta avanzata a suo tempo, ma anzi, per quanto sopra esposto la situazione e ulteriormente peggiorata, ii comitato 04 decide di sospendere i propri lavori in attesa di ade­ guate riposte chiarificatrici. " per ora queste riposte non sono pervenute anche perche la lettera e recente e non credo che ii ministro sia proprio disoccupato. siccome gran parte di voi e inserita in progetti nazionali aspettatevi tempi lunghi e quattrini pochi. vorrei utilizzare gli otto minuti che mi sono rimasti per chiacchierare un po' con voi di problemi geopedologici che ho coltivato per tanti anni. mi riconosco qui, insieme ai colleghi genovesi come nipote di un grande nonno che ha onorato questa universita. sono allie­ vo di un allievo del marchese gaetano di rovereto che e stato nei primi anni di questo secolo un grande esploratore e in sud america e in italia. egli scrisse poi un libro tra i piu difficili a leggere ma certo denso di acute osservazioni e che tutti noi dai capelli bianchi abbiamo studiato da giovani ass.istenti. ii suolo e un sistema natur'ale molto delicate e complesso ma e nel contempo una risorsa fondamentale dell'uomo. sono percio in disaccordo con ii geologo citato da boriani perche mi son sempre occupato dei primi decimetri, dei primi metri dal piano di campa­ gna. ho cercato cos1 di recare un contribute alla geologia del quaternario e a quella applicata. qui siamo in sede aiqua cioe in sede dell 'associazione ltaliana del quaternario e siamo in grande prevalenza cultori di scienze della terra, ma ci sono anche colleghi a noi vicini e vorrei parlare un po' a tutti. ii problema dello studio del suolo nelle universita italiane e molto delicate. prendiamo ii corso di laurea in scienze biologiche come esempio. i giovani che studiano le piante e gli animali e tante altre belle cosine escono dall'universita senza sapere che ii grani­ te e una roccia eruttiva, se non lo hanno imparato al liceo. non hanno quindi la piu pallida idea di che paesaggi si vanno formando sotto i vari climi. non sanno di geomorfologia e nemmeno di geopedologia. nessuna idea dei suoli che si originano da quei graniti , i suoli su cui vivono le piante del cui comportamento dovrebbero essere i migliori conoscitori. se si raffrontano questi laureati con i nostri vecchi maestri che erano quasi tutti dottori in scienze naturali , che conoscevano oltre alle discipline geomineralogiche anche le piante e gli animali, si deve ammettere che i giovani d'oggi hanno una preparazione ben piu limitata. e non e che con questi laureati si risolveranno molti problemi ambientali. la situazione per la pedologia non e rosea neppure nel corso di scienze naturali. solo in qualche sede la geopedologia viene impartita. di gregorio ricordava dianzi angelo aru, l'unico cattedratico di geopedologia nella facolta di scienze mentre tutti gli altri seggono in facolta agrarie e forestali. si parla tanto di conservare ii suolo ma e ben difficile conservare una risorsa, come ii suolo e, se non la si conosce. esiste una contraddizione patente perche mai come oggi c'e stata una cos1 forte richiesta dalle varie amministrazioni regionali e locali soprattut­ to di cartografia pedologica di base da cui poi dedurre delle carte tematiche le piu diverse. faro un esempio. se in una provincia padana, parma o mantova che sia, ci sono 50 o 60.000 maiali questi originano una tale quantita di liquami che e ben difficile smaltir­ li. bisagna allora conoscere bene sia la situazione idrogeologica che la natura dei suoli per programmare razionalmente nello spazio ma anche nel tempo tale smaltimento. sul mercato oggi non ci sono molte persone preparate per questi compiti anche se la situazione, dopo i corsi del formez e del cifda, va pian piano migliorando. la cartografia pedologica e stata molto utile in molti casi. perche? perche abbiamo molto spesso giustapposti suoli assai diversi 215 dal punto di vista del ministero dell 'ambiente quindi un punto di vista relativamente esterno e generale rispetto a questo tipo di pro­ blemi? lnnanzitutto che, ogni qualvolta, e l'elenco potrebbe essere lunghissimo, si fa riferimento a gravi compromissioni dell'ambiente, dissesti , degradi e quant'altro, nella totalita si potrebbe dire dei casi , molto nasce dal fatto che le attivita dell'uomo non hanno tenuto nel debito conto , nella debita misura, appunto delle informazioni e delle peculiarita dal punto di vista generalmente definibile come geologico dei vari siti , delle varie aree dove si andava a intervenire. questa si puo, ovviamente, riferire allo sviluppo urbanistico, si puo riferire allo sviluppo industriale, si puo riferire allo sviluppo e alla programmazione delle attivita agricole, si puo riferire anche alla assolutamente disastrosa politica dei lavori pubblici in tema, appunto , di difesa del suolo e di gestione dei corsi d'acqua. lo non voglio e non posso dare i giudizi cosl drastici che sono stati dati sul ministero dei lavori pubblici perche non credo, tra l'altro, che sia una questione esclusivamente, o perlomeno fondamentalmente, di personale tecnico dei lavori pubblici. e' un problema di cultura, e un problema di cultura che noi stiamo, veramente, faticando ancora con scarsi risultati ancora ad affrontare efficacemente. per dirla con una battuta, ancora oggi in italia, malgrado tutta una serie di consapevolezze ormai diffuse a livello scientifico, accademico, ambientalista e non, assistiamo a una politica di difesa del suolo esclusivamente indirizzata in termini ingegneristici. quindi , per fare un esempio e una battuta un po' banale e semplice, potendo scegliere tra l'adeguamento degli alvei dei fiumi alle piene che via via possono manifestarsi e la scelta inversa, di tentare di adeguare le piene al reticolo idrografico, si privilegia sempre esclusivamente e sistematicamente la prima, cioe si punta esclusivamente ad adeguare gli alvei dei fiumi con artifici e sistemi di vario genere alle piene che la natura ci puo mandare la natura lino a un certo punto perche e evidente che l'intervento dell'uomo, appunto nei settori che indicavo prima, cioe dello sviluppo urbanistico, dello sviluppo territoriale, della programmazione di determinate attivita produttive, in realta sappiamo e spesso anche determinante nell'aggravamento o nell'incremento dei fenomeni. gli esempi potrebbero essere innu­ merevoli si va dai comuni della cintura vesuviana a venezia, al bacino del po ecc. ora, questo e un limite contra ii quale noi ci scontriamo quotidianamente ed e una battaglia che ancora ci vede perdenti e vede prevalere , in maniera pressoche esclusiva, questa cultura di tipo ingegneristico, che quindi prescinde da tutta una serie di scenari alternativi , prescinde da tutta una serie di interventi anche operativi che non abbiano l'alveo del fiume come oggetto, ma abbiano ii versante, ii territorio e ii bacino e via dicendo. e tutto cio, in realta, per quanta male si possa parlare della l. 183/89, e esattamente ed esplicitamente previsto, e prevista proprio questa pianificazione integrata a livello di bacino, che oggi , come e evidente, stenta molto a decollare. ii massimo che ii ministero dell 'ambiente riesce a fare oggi e quello di ridurre i danni e cioe di impedire che gli interventi , ancora oggi piu o meno casualmente disseminati sul territorio, malgrado tangentopoli, che questi interventi, piu o meno casualmente resi prioritari da esigenze che tutto hanno a che fare tranne che con quelle del territorio, siano ii piu possibile ricondotti ad un quadro programmatico almeno razionale. un altro grosso limite che possiamo rilevare e quello dell'organizzazione della conoscenza, dal punto di vista proprio delle scien­ ze della terra, quindi delle discipline geologiche. siamo, molto spesso, in presenza di studi a diverse scale, a diversi livelli dal piano di bacino sino a studi piu specifici che raramente sfuggono da una routine piatta e assolutamente acritica. manca cioe una consa­ pevolezza, una cultura della finalizzazione degli studi e delle conoscenze. in sostanza si parte dall 'inizio, si studiano tutte le varie pos­ sibili dislocazioni degli strati geologici e quant'altro, senza che pero questo, poi , di fatto corrisponda a una finalizzazione razionale che possa dipendere dalle caratteristiche peculiari della zona, dai problemi emergenti , dalle priorita ecc. quindi , quello che noi lamentiamo e, in sostanza, un'emarginazione non solo della variabile ambiente, che viene considerata al piu e nel migliore dei casi un vincolo (malgrado la parola ambiente sia oggi estremamente di moda, spesso pronunciata anche a sproposito) ma nei fatti constatiamo che l'ambiente e comunque relegato a essere un vincolo, una limitazione, una soglia rispetto ad altre finalita che comunque devono essere perseguite, indipendentemente da ogni altra considerazione . quindi lamentiamo un mancato inserimento delle scienze ambientali e delle scienze geologiche in particolare proprio nei processi di pianificazione; tutt'al piu si chiede alle scienze ambientali, alle scienze geologiche, una sorta di certificazione, di verifica, di avallo a scelte che derivano da altre considerazioni , che possono essere piu o meno legittime, piu o meno ammantate da considerazioni di carattere economico o altro, ma che comunque non contemplano in un unico processo decisionale lo studio, l'elaborazione e l'utilizzazione dei dati che provengono dalle discipline ambientali e dalle discipli­ ne geologiche. di conseguenza se uno spunto di riflessione e di innovazione puo venire dal ministero dell'ambiente, credo che sia in questi termini e cioe fare in modo che i risultati degli studi delle discipline geologiche in generale siano piu agevolmente fruibili ; questo e, credo, la cosa di cui si ha maggiormente bisogno oggi : da una parte, diciamo cosl , da un punto di vista dell'inserimento delle cono­ scenze e dei tematismi all'interno di un vero e proprio processo di supporto alla decisione; per evitare appunto questo collateralismo, questa emarginazione rispetto al processo di scelta, al processo di formazione della decisione; e dall'aftra, invece, lo sforzo per rende­ re ii piu possibile sintetica l'indicazione che deriva dalle discipline geologiche. noi spesso ci troviamo di fronte a prodotti estremamente frammentati per cui c'e l'aspetto idrogeologico, l'aspetto geomorfologico, l'aspetto geopedologico, l'aspetto geochimico. certamente sono molto d'accordo con una osservazione fatta in precedenza, vi e una straordinaria sottovalutazione degli aspetti geochimici nel campo della pianificazione delle risorse idriche, ad esempio , nel senso che si vanno a cercare fonti di inquinamento di natura antropi­ ca, senza minimamente considerare che la fonte geochimica, in determinati casi , perlomeno in determinate regioni, puo svolgere un ruolo fondamentale, del quale occorre tener conto per poter poi stabilire quanta di quello che andiamo trovando nell'acqua, nelle falde, sia effettivamente di origine antropica. c'e pero una frammentazione dei contributi, almeno questa e la nostra impressione, e anche a livello delle prime bozze di piano di bacino che si cominciano a intravedere. cio che a noi sembrerebbe piu utile e, invece, cercare di rendere l'intero contributo delle discipline geologiche sintetizzabile in unita tipiche. sentivo da chi mi ha preceduto una osservazione molto interessante da questo punto di vista, che tra l'altro noi abbiamo gia proposto nelle varie sedi dove siamo chiamati a dare ii (segue da p. 220) 3 miliardi 5 miliardi 15 lnizia erosione superficiale, ma con scarsa alterazione e senza possibilita di ossidazione. la terra comincia a raffreddarsi in maniera significativa e si organizl'atmosfera ha massa 1/10 dell' prime cellule pro attuale ed e ricca di co2 e di composti riducenti. lnizia la formazione di una atmosfera con massa e prescariote. 3.8 ma di anni fa: origine della vita. non esiste ancora. za in diversi strati con diverse caratteri sione molto limitata, ma contestiche fisiche e chimiche. la terrasi forma per aggrega­ zione di materiale cosmico con composizione molto diversa da quella del sole, caratterizzata dalla presenza di tutti gli elementi , anche i piu pesanti. da un'ammasso indifferenziato di materia ed energia si verifica, attraverso processi che non sono ben conosciuti , tutta una evoluzione geochimica che passa attraverso la formazione di tutti gli elementi chimici naturali (92) a partire dall' idrogeno. big bang nente i vapori (acqua) e gas ne­ cessari al successivo sviluppo della vita. bibliografia berner r. a. , 1991 a model for atmospheric co2 over phanerozoic time. am. jounal of science, 291, 339-376. 221 dall'aglio m., 1994 (in stampa) circolazione degli elementi in natura e sviluppo def/a biosfera. enciclopedia "scienze e tecnologie", rizzoli grandi opere, in corso di stampa. ii prof. ippolito fa presente che gli interventi dovrebbero essere centrati su quel/o che hanno detto gli oratori de/la tavola rotonda, e non dovrebbero essere de/le ulteriori comunicazioni scientifiche. viene data la para/a al dr casale de/la comunita europea (*). prende la para/a ii prof. f. petrucci (universita di parma): esiste la necessita di attivare una nuova geologia per l'ambiente? l'aiqua ha risposto al quesito con atto costitutivo, in quanto e una associazione che riunisce i ricercatori di tutte le discipline che concorrono allo studio del quaternario, sia sotto l'aspetto della ricerca pura che di quella applicata al territorio. la geologia del quaternario nella comune accezione significa disciplina rivolta allo studio dell'evoluzione geologica sia pre­ sente che del passato recente; essa risponde appieno alle istanze di conoscenza del territorio, sia per quello che attiene i processi evolutivi naturali che quelli indotti dall'uomo, i quali hanno assunto un ruolo determinante in alcune regioni del globo. ouindi la geologia del ouaternario contribuisce fattivamente con ii proprio bagaglio di conoscenze a programmare la conservazione , manu­ tenzione e ripristino dell'ambiente. lnstabilita del suolo, dei versanti, dell'idrografia, delle caste, ecc., fino agli eventi vulcanici e sismici, sono fattori a cui le popola­ zioni non vorrebbero sottostare: per contra l'ambiente non puo adeguarsi a vincoli e modificazioni imposte con la propria attivita dall' uomo. la superficie terrestre e soggetta ad un continua dinamismo, in genere lento, ma talora devastante e calamitoso, come nel corso di alluvioni , terremoti o eruzioni vulcaniche. gli altri processi naturali di trasformazione, che si possono definire inesauribili, sono lenti. localmente pero l'ambiente viene aggredito e manomesso dalla concentrazione di attivita a cui l'uomo lo sottopone con defore(*) non e stato possibile includere questo intervento nei presenti atti perche ii testo relativo non era ancora pervenuto al momenta dell'invio alla stampa del volume (31 agosto 1994) (n. d. r.). sess 5_16022011_edi as.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 carbon isotope composition of archaeobotanical remains for the palaeoclimatic reconstruction alessia masi 1, ilaria baneschi 2, laura sadori 1 & giovanni zanchetta 3 1 dipartimento di biologia ambientale università “sapienza”, roma 2 istituto di geoscienze e georisorse – cnr, pisa 3 dipartimento di scienze della terra università di pisa, pisa corresponding author: a. masi <alessia.masi@uniroma1.it> abstract: masi a. et al., carbon isotope composition of archaeobotanical remains for the palaeoclimatic reconstruction (it issn 0394-3356, 2011) a long-lived anatolian archaeological site (arslantepe, malatya plain) was investigated under a palaeoclimate perspective. identified plant charred macroremains underwent an isotopic analysis to determine carbon isotope composition. the results obtained are used to assess the degree of climate changes in the site and its surroundings. riassunto: masi a. et al., la composizione isotopica del carbonio di resti archeobotanici per la ricostruzione paleoclimatica. (it issn 0394-3356, 2011) un sito dell'anatolia, caratterizzato da una lunga occupazione, è stato preso in considerazione per una ricostruzione paleoclimatica. alcuni resti vegetali carbonizzati sono stati sottoposti ad analisi isotopica per determinare la composizione isotopica del carbonio. i risultati ottenuti contribuisscono a comprendere i cambi climatici del sito e del territorio circostante. key words: plant macroremains, isotopes, archaeological site, climate change parole chiave: macroresti vegetali, isotopi, sito archeologico, cambiamento climatico the site of arslantepe (arslan = lion, tepe = mound) is located in the malatya plain (eastern turkey, central anatolia). today is a hill, 30 m high (fig. 1), formed by a series of settlements built and destroyed in five thousand years of almost uninterrupted occupation (table 1). arslantepe has been bringing to light extraordinary remains of past prehistoric and protohistoric cultures of eastern anatolia. the excavation is still ongoing, the oldest archaeological level dates back to the 7th millennium bp, the youngest is of byzantine times. excavations of “la sapienza” university of rome at the site have been carried out uninterruptedly since 1961, bringing to light a lot of archaeobotanical material coming from the entire succession of occupation of the site. the archaeobotanical studies highlighted the presence of various botanical taxa preserved by charring, belonging to arboreal and crop species. great variety was found, the diversity in cultivated taxa and the selective use of wood can be either due to a choice or even to environmental availability. the charcoal assemblages (fig. 2) of the 215 216 fig. 1, arslantepe. aerial photograph of the site arslantepe. fotografia aerea del sito. fig. 2, arslantepe. charcoal changes in the five investigated periods. percentage diagram of ecological groups (see text) arslantepe. cambiamenti nei carboni nei cinque periodi indagati. diagramma percentuale dei gruppi ecologici (vedi testo) 216 ms. received: testo ricevuto il investigated archaeological site indicate that wood resources were mainly exploited from two local ecological communities, the woody steppe (composed by deciduous and semi-deciduous  oaks with rosaceans) and the riparian vegetation. the last is from wet environments, including both hydrophilous (mainly alders and poplars with a slow amount of tamarisks) and possibly hygrophilous (elms and ashes) taxa. a considerably minor contribution is from mountain taxa (pines and junipers). the comparison of the relative taxa abundances in the single periods indicates that woodland-steppe elements are very abundant for half millennium, during the early bronze age, from 3000 to 2500 years bc (vi b1, vi b2 and vi c periods). on the contrary hydrophilous elements are quite important during the late chalcolithic (vi a) and at the end of the early bronze age (vi d), while woodland-steppe elements and mountain ones show opposite values in these two periods. as important structural changes are found between the various periods of arslantepe, it is not clear if the important variations found in plants use by the successive settlers are due to cultural choices or to environmental changes. a contribute comes from the study of the stable carbon isotope carried out both on ancient and present-day plants. the relationship between the fractionation of carbon isotope and climate condition is well known. the 13c/12c ratio depends mainly on moisture stress and isotopic ratio of atmospheric co2 (farquhar g.d. et al., 1989). such independent information of environmental variations permits to discriminate between cultural and environmental change (hall g. et al., 2008; riehl s. et al., 2008). 13c/12c ratio analysis were performed by combustion in a elemental analyzer (carlo erba, ea1108) coupling with isotope ratio mass spectrometer (delta plus xp finnigan) via the finnigan mat conflo ii interface at igg-cnr of pisa. more than one hundred charred samples of deciduous quercus and juniperus were analyzed. they come from five archaeological periods of arslantepe, ranging from late chalcolithic v (53505000 bp) to early bronze age iii (4500-4000 bp). the variability of data is high, however a d13c variation is present and some trends recognizable. the data coming from fossil assemblages are compared with those from living plants of the same genus in order to reconstruct past environment and climatic trend through more than one millennium. references farquhar g.d., ehleringer j.r. & hubik k.t. (1989) carbon isotope discrimination and photosynthesis. annual review of plant physiology 40, 503-537. hall g., woodborne s.m. & scholes m. (2008) stable carbon isotope ratios from archaeological charcoal as palaeoenvironmental indicators. chemical geology, 247(3-4), 384-400. riehl s., bryson r. & pustovoytov k. (2008) changing growing conditions for crops during the near eastern bronze age (3000-1200 bc): the stable carbon isotope evidence. journal of archaeological science, 35, 1011-1022. january 14, 2011 14 gennaio 2011 table 1, arslantepe. chronological periods arslantepe. periodi cronologici a. masi et al. << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /none /binding /left /calgrayprofile (dot gain 20%) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /error /compatibilitylevel 1.4 /compressobjects /tags /compresspages true /convertimagestoindexed true /passthroughjpegimages true /createjobticket false /defaultrenderingintent /default /detectblends true /detectcurves 0.0000 /colorconversionstrategy /cmyk /dothumbnails false /embedallfonts true /embedopentype false /parseiccprofilesincomments true /embedjoboptions true /dscreportinglevel 0 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/hrv (za stvaranje adobe pdf dokumenata najpogodnijih za visokokvalitetni ispis prije tiskanja koristite ove postavke. stvoreni pdf dokumenti mogu se otvoriti acrobat i adobe reader 5.0 i kasnijim verzijama.) /hun 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can be opened with acrobat and adobe reader 5.0 and later.) >> /namespace [ (adobe) (common) (1.0) ] /othernamespaces [ << /asreaderspreads false /cropimagestoframes true /errorcontrol /warnandcontinue /flattenerignorespreadoverrides false /includeguidesgrids false /includenonprinting false /includeslug false /namespace [ (adobe) (indesign) (4.0) ] /omitplacedbitmaps false /omitplacedeps false /omitplacedpdf false /simulateoverprint /legacy >> << /addbleedmarks false /addcolorbars false /addcropmarks false /addpageinfo false /addregmarks false /convertcolors /converttocmyk /destinationprofilename () /destinationprofileselector /documentcmyk /downsample16bitimages true /flattenerpreset << /presetselector /mediumresolution >> /formelements false /generatestructure false /includebookmarks false /includehyperlinks false /includeinteractive false /includelayers false /includeprofiles false /multimediahandling /useobjectsettings /namespace [ (adobe) (creativesuite) (2.0) ] /pdfxoutputintentprofileselector /documentcmyk /preserveediting true /untaggedcmykhandling /leaveuntagged /untaggedrgbhandling /usedocumentprofile /usedocumentbleed false >> ] >> setdistillerparams << /hwresolution [2400 2400] /pagesize [612.000 792.000] >> setpagedevice impaginatogiraudi ii rroocckk ggllaacciieerr ttaarrddoo--pplleeiissttoocceenniiccii eedd oolloocceennii ddeellll''aappppeennnniinnoo - eettàà,, ddiissttrriibbuuzziioonnee,, ssiiggnniiffiiccaattoo ppaalleeoocclliimmaattiiccoo cc.. ggiirraauuddii enea, cr casaccia, c.p. 2400, 00100 roma a.d. riassunto sugli appennini sono stati individuati circa 40 rock glacier, tutti contemporanei o posteriori all'ultimo massimo glaciale. essi si sono sviluppati in cinque diverse fasi, l'ultima delle quali databile tra circa 3000 e 780±40 anni bp; i rock glacier presenti alle quote inferiori si sono formati nel corso dell’ultimo massimo glaciale (lgm), ma il loro maggiore sviluppo ebbe luogo nelle fasi tardiglaciali. i rock glacier si rinvengono maggiormente su quei massicci caratterizzati, durante l’lgm, da limite delle nevi (ela) non molto basso: l'intero appennino settentrionale ed i massicci che avevano un ela basso, e che attualmente sono soggetti a precipitazioni molto più elevate, ne sono risultati privi. inoltre i rock glacier si sviluppavano per lo più nel corso delle fasi climatiche aride o non molto umide. dalla distribuzione areale dei rock glacier si deduce che, durante le fasi finali dell’lgm, nel tardiglaciale e nell'olocene iniziale, c'è stata, oltre che una migrazione verticale, anche uno spostamento verso nord del limite della loro area di distribuzione: quindi il limite del permafrost discontinuo montano è passato da 39°55'n a 41°45'n e poi a 42°07'n. in seguito ci fu soltanto una migrazione verticale, in quanto nel tardo olocene i rock glacier hanno potuto svilupparsi solo sulle parti sommitali dei due massicci più elevati. abstract the late pleistocene and holocene apennine rock glaciers (italy) – age, distribution and palaeoclimatic significance. rock glaciers have been found in the gran sasso, greco, maiella and velino massifs and in the breccioso, terminillo and pollino mounts. the apennine rock glaciers are inactive, with the exception, perhaps, of a very small rock glacier, which might be active. the northern apennines (fig. 1) consist of ranges up to 2165 m in height, and are formed mainly by sandstones and arenaceous marls. during the last glacial maximum (lgm) and its retreat phases, in the northern apennines many glaciers existed: the end moraines of such glaciers have been found up to about 700 m a.s.l. the studies show that during the last glacial maximum the equilibrium line altitude (ela) was between 1300 and 1550 m. no rock glaciers are reported in bibliography. photogeological and field researches, also, have not led to any results. according to current data, in the northern apennines, rock glaciers are lacking. the highest central apennine massifs (fig. 1) consist mainly of mesozoic and cenozoic carbonatic rocks. in this part of the chain lie the highest massifs of the whole apennines (gran sasso, 2912 m; maiella, 2793 m; velino 2486 m; sibillini, 2476 m). in the central apennines considerable glacial remnants are preserved, and, in particular, the features and deposits dated to the lgm and its retreat phases. the ela during lgm was between 1500 and 1700 m, in the western portion (fig. 1), and between 1600 and 2100 m in the central and eastern area. the majority of the rock glaciers so far mentioned in literature are in the central apennines. photogeological and field surveys have shown, however, that in the western portion of this part of the chain there are no rock glaciers, even in mountain areas higher than 2000 m. in the central and eastern parts, the rock glaciers are found above a minimum height of 1570 m, up to approximately 2550 m. all the rock glaciers have been found in places glaciated during the lgm, namely, mostly in valleys and on slopes facing nw, n and ne. the rock glaciers developed on glacial drift, and they often deform moraine ridges located on the threshold of the cirques. the rock glaciers least weathered and covered by scanty vegetation, looking younger, develop instead on slope waste deposits. the largest rock glaciers have been found in the maiella and velino massifs and are about 1 km long. the highest peaks of the southern apennines are mt. pollino (2267 m) and mt. sirino (2005 m). they show clear traces of glaciers dating from the lgm and their retreat phases. during the lgm, on mt. pollino (latitude 39°55’) the equilibrium line altitude was 1800 m, while on m. sirino it was 1600 m. only one rock glacier has been found on mt. pollino. it overlies the moraine of the early phases of glacial retreat, about 1750 m a.s.l; it is older than the stadial moraine covered by loess dated 15-16,000 years bp, present also in central italy. the majority of the rock glaciers were formed between 20,000 and 10,000 years bp, when the mean yearly temperatures were still 4 – 6 °c lower than the present ones; however, their geographic distribution gives rise to some important considerations. in the northern apennines, (latitude above 44°n) there are no rock glaciers, while there are some at more southerly latitudes (about 40°n), in mountains of similar elevation. the ela during the lgm reached definitely lower altitudes (1300-1550 m) than in the central and southern apennines (1500-2100 m); the absence of rock glaciers thus, cannot be due to the temperature, but to the different amount of precipitation. even now, the highest areas of the northern apennines receive precipitation of between 1500 and 2000 mm/year: the values are far higher than those of the central-southern part of the chain. it is to be assumed that the lack of rock glaciers was caused by the abundant snow precipitation which insulated the ground against frost penetration, and not by temperature differences. in the apennine chain, about 40 rock glaciers dated to the last 20,000 years have been identified. they developed in five phases, the last one between 3000 and 780±40 years bp; the rock glaciers found at lower height were formed during the lgm, but the majority formed during the late glacial phases. rock glaciers have been found mainly on massifs with a higher ela-lgm and a present lower precipitation rate; in the whole northern apennines and on the massifs with a lower ela (currently having a higher precipitation rate) rock glaciers are lacking. moreover, the rock glaciers developed mainly during the dryer periods or in places where precipitation were not very great. the geographical distribution of the rock glaciers, corresponding to the boundary of the areas with mountain permafrost, suggests that, during the final phases of the lgm period, in the late glacial and in the early holocene, there was also an altitude and latitude shift with a reduction of this boundary, following the temperature increase. from the altitude of 1570/1600 m, the boundary of discontinuous mountain permafrost rose to 2300/2500 m during the late holocene, and it is now even higher. about the time of the latitude shift, the boundary migrated northwards, from 39°55'n to 41°45'n and later to 42°07'n. parole chiave: rock glacier, appennino, ultimo massimo glaciale, olocene, paleoclima. key words: rock glacier, apennine, last glacial maximum, holocene, paleoclimate. il quaternario italian journal of quaternary sciences 1155(1), 2002, 45-52 iinnttrroodduuzziioonnee la presenza di rock glacier in appennino (fig. 1) venne segnalata per la prima volta sul massiccio gran sasso (m 2912, massima elevazione dell'appennino) da giraudi (1988). in seguito ne fu segnalata la presenza in altre zone del gran sasso, sui massicci del m. greco, della maiella e del velino, sui monti breccioso, terminillo, pollino (ghisetti & vezzani, 1990; damiani e pannuzi 1993; dramis e kotarba,1994; jaurand,1994; giraudi,1996, 1997b; 1998a,b,c,d; giraudi & frezzotti, 1997). ad eccezione, forse, di un rock glacier di dimensioni estremamente ridotte, che potrebbe essere attivo (dramis & kotarba, 1994), gli altri segnalati in letteratura e quelli rinvenuti nel corso del presente studio non mostrano segni di attività. i resti dei rock glacier sono generalmente ben conservati; si trovano infatti su montagne costituite prevalentemente da rocce carbonatiche meso-cenozoiche, soggette a carsismo: l'erosione superficiale è stata perciò limitata a causa dell'estrema riduzione del runoff. 46 giraudi nel corso del presente lavoro vengono riportati i risultati di una ricerca svolta sull'intera catena appenninica, basata su indagini fotogeologiche, di campagna e ricerche bibliografiche. lo studio dei rock glacier relitti dell’appennino è stato svolto al fine di ottenere indicazioni sull’evoluzione ambientale e paleoclimatica dell’area, in quanto la presenza di permafrost e le variazioni del suo limite di distribuzione nel corso del tempo possono servire a valutare l’evoluzione della temperatura dall’ultimo massimo glaciale (lgm) fino all’attuale. inoltre la datazione dei rock glacier permette la correlazione con eventi indicati da altri proxy-data e può servire a definire meglio le condizioni che hanno favorito lo sviluppo del permafrost. mmeettooddoollooggiiaa i rock glacier oggetto del presente lavoro sono situati su fondi vallivi e nell’ambito dei circhi glaciali, altri sono situati lungo i fianchi vallivi, alla base di accumuli fig. 1 carta schematica dell'appennino con indicazioni sulla quota della linea delle nevi nel corso dell'ultimo massimo glaciale e la distribuzione dei rock glacier. schematic map of the apennine chaine, altitude of the equilibrium line altitude during lgm, distribution of rock glaciers. legend: 1=area >1000 m a.s.l.; 2=present shore line; 3= lgm shore line. hanno dato risultati negativi. il grado di conservazione delle forme glaciali nell’appennino settentrionale è, generalmente, inferiore rispetto a quelle dell’appennino centrale. quindi non si può escludere del tutto che sia esistito qualche rock glacier, ora scomparso a causa del rimodellamento, ma una loro diffusa presenza appare improbabile. appennino centrale i maggiori massicci dell'appennino centrale (fig. 1) sono costituiti prevalentemente da rocce carbonatiche meso-cenozoiche. in questa parte della catena sono presenti anche i più alt i massicci di tutto l'appennino (gran sasso, 2912 m; maiella, 2793 m; velino 2486 m; m. sibillini, 2476 m). nella porzione più elevata del massiccio del gran sasso esiste il piccolo ghiacciaio del calderone, in via di forte riduzione (smiraglia & veggetti,1992; gellatly et al., 1994), e le aree sommitali dei massicci principali sono caratterizzate da fenomeni periglaciali quali crioclastismo, soliflussioni. solo sui massicci del gran sasso e della maiella sono presenti patterned ground caratterizzati da sorted stripes, poco diffusi a partire da circa 2400 m sul primo massiccio, molto estesi a partire da circa 2600 m sul secondo (sacco, 1908; giraudi, 2001). le montagne dell'appennino centrale presentano notevoli resti glaciali, databili per lo più all’ultimo massimo glaciale (lgm) e alle sue fasi di ritiro. in base ai lavori più recenti (damiani & pannuzi, 1979; federici, 1979; jaurand,1994; giraudi & frezzotti, 1997; giraudi, 1997b; 1998a,b,c,d) il limite nivale durante l’lgm era compreso tra 1500 e 1700 m nella porzione occidentale (fig. 1) e tra 1600 e 2100 m nel resto dell'area. secondo giraudi & frezzotti (1997) la massima espansione glaciale venne raggiunta prima di 22.680±630 anni bp; il ritiro glaciale iniziò attorno a 21.000 anni bp. minori espansioni si ebbero poco prima di 15.000 anni bp e attorno a 11.000 anni bp. nell'olocene i ghiacciai sparirono del tutto; il ghiacciaio del calderone si riformò in un periodo più recente di circa 4000 anni bp (giraudi, 2000). la maggior parte dei rock glacier finora segnalati in letteratura si trova nell'appennino centrale, su versanti con esposizione verso i quadranti settentrionali; in rarissimi casi si trovano su versanti rivolti a sud, come a campo imperatore (giraudi &.frezzotti, 1997). le ricerche fotogeologiche e di campagna hanno mostrato però che nella porzione occidentale di questo tratto di catena, anche quando vi sono monti di altezza superiore a 2000 m, non sono presenti rock glacier. nel resto dell'area, i rock glacier si trovano a partire da una quota minima di 1570 m, fino a circa 2550 m. i rock glacier ed i fenomeni periglaciali attivi si trovano tutti in zone occupate dai ghiacciai nel corso dell’lgm. molti rock glacier si sviluppano a spese del detrito di origine glaciale, e spesso deformano depositi glaciali posti sulla soglia dei circhi; in vari casi il flusso non è diretto verso valle, ma verso la depressione dei circhi. le forme meno alterate e con scarsa copertura vegetale, di aspetto più fresco, si sviluppano, invece, a spese del detrito di versante. per quel che riguarda le dimensioni, i rock glacier 47i rock glacier tardo-pleistocenici ... di detrito di falda. il loro riconoscimento da parte degli autori elencati in precedenza è avvenuto su base morfologica. in generale, per quel che riguarda i rock glacier attivi vi sono diversi metodi di classificazione ancora oggetto di discussione: secondo hamilton & whalley (1995) la classificazione può essere basata su diversi parametri, alcuni possono essere misurati e quantificati, altri possono solo essere dedotti. detti parametri includono la morfologia, la dinamica, i processi di formazione, la posizione, le caratteristiche interne, il regime termico e l’età. la classificazione implica una interpretazione genetica che può essere soggettiva anche sui rock glacier attivi che possono essere studiati con vari metodi. poiché nel presente lavoro vengono presi in considerazione rock glacier inattivi, in parte modificati dall’alterazione e dell’erosione, appare difficile procedere ad una adeguata classificazione degli stessi e definirne l’origine: si provvederà quindi a fornire le informazioni disponibili senza introdurre classificazioni e distinzione di origine, tenendo conto però che la maggior parte dei rock glacier ed i più grandi tra questi, si sviluppano su detrito di falda, come segnalato da dramis & kotarba (1994). i rock glacier dell’appennino sono situati, con rare eccezioni, in aree occupate dai ghiacciai nel corso dell’lgm, in valli rivolte verso i quadranti settentrionali. le differenze di quota tra i diversi rock glacier di età analoga posti sullo stesso massiccio sono da attribuire a fattori legati alla esposizione ed alla morfologia delle valli. sui massicci ubicati a varie distanze dal mare ed a differente latitudine, le quote alle quali sono presenti i rock glacier possono essere determinate dalle caratteristiche regionali del clima e dalle variazioni latitudinali di temperatura causate dal diverso grado di insolazione. ii rroocckk ggllaacciieerr ddeellll''aappppeennnniinnoo la porzione di catena appenninica presa in considerazione è compresa tra circa 39°50' n e 44°20'n: è stata esclusa dal lavoro l'estrema porzione meridionale che, per latitudine e quota dei rilievi, non sembra adatta allo sviluppo di rock glacier nel tardo pleistocene e nell'olocene. appennino settentrionale l'appennino settentrionale (fig. 1) è formato da rilievi che possono arrivare a 2165 m di quota, litologicamente costituiti in prevalenza da arenarie e marne arenacee. nel corso dell’ultimo massimo glaciale (lgm) e delle sue fasi di ritiro, erano presenti molti ghiacciai, per lo più in valli rivolte verso i quadranti settentrionali: gli apparati morenici frontali di tali ghiacciai sono stati rinvenuti fino a circa 700 m di quota. gli studi condotti da vari autori (federici, 1981; gruppo ricerca geomorfologia,1982; federici & tellini, 1983; braschi et al., 1985; jaurand, 1994) indicano che durante l’lgm il limite delle nevi (ela) era a quote comprese tra 1300 e 1550 m. nessun rock glacier risulta segnalato in bibliografia. anche le ricerche fotogeologiche e di campagna più estesi si trovano sui massicci della maiella e del velino e raggiungono lunghezze di circa 1 km. appennino meridionale i monti più elevati dell'appennino meridionale sono il pollino (2267 m) ed il sirino (2005 m), e conservano evidenti tracce dei ghiacciai dell’lgm e delle fasi di ritiro. durante l’lgm, sul m. pollino (latitudine 39°55') l’ela era a 1800 m, mentre sul m. sirino era a 1600 m (palmentola & acquafredda, 1983; palmentola et al., 1990; jaurand, 1994; giraudi, 1998d). un solo rock glacier è stato identificato sul m. pollino in un versante esposto a nord. ddaattaazziioonnee ddeeii rroocckk ggllaacciieerr la datazione delle fasi di sviluppo dei rock glacier è stata ottenuta sia in base ai rapporti tra questi e le morene dell’lgm e stadiali di età nota, sia attraverso lo studio dei depositi e dei suoli che li coprono e si riferiscono all’appennino centrale e meridionale. su alcuni cordoni di rock glacier sono stati eseguiti piccoli scavi o, specialmente nelle depressioni riempite da materiali fini, sondaggi mediante trivella a mano profondi fino a 4 m: sono stati in tal modo rinvenuti sedimenti eolici, livelli di tephra, suoli sepolti, sedimenti lacustri. lo studio di tali depositi, che, non essendo deformati debbono essere stati messi in posto quando il rock glacier non era più dinamicamente attivo, ha permesso la datazione delle fasi di sviluppo dei rock glacier. a proposito del significato delle datazioni di seguito esposte, occorre evidenziare che esse potrebbero indicare solo la fine dell’attività dinamica dei rock glacier e non la scomparsa effettiva del permafrost; questo potrebbe essere rimasto presente tra il detrito per periodi di tempo attualmente non determinabili. i fase i rock glacier di questa fase, sono situati alle quote inferiori (i più bassi a 1570÷1600m); interessano le morene formatesi nelle prime fasi di ritiro dei ghiacciai dell’lgm. l'inizio del ritiro glaciale è databile a circa 21.000 anni bp giraudi & frezzotti (1997). altri rock glacier sono posti a quote leggermente più elevate (da 1650 a 1750/1800) ma sempre a ridosso delle morene delle prime fasi di ritiro. nelle depressioni presenti su alcuni di questi è stato rinvenuto un loess ricco in quarzo databile a 15÷16.000 anni fa (frezzotti & giraudi,1991; giraudi, 1998b) che copre anche le morene dell’lgm, ma non quelle tardiglaciali (giraudi, 1997a). lo sviluppo di questi rock glacier può essere durato al massimo 5000÷6000 anni. ii fase i rock glacier di questa fase, i più numerosi, possono essere contemporanei o successivi ad alcune morene tardiglaciali; si possono trovare a varie quote, al di sopra di 1750/1800 m, sia in alcuni circhi glaciali, sia al di fuori. in alcune depressioni, i sondaggi a mano condotti nell’ambito del presente studio hanno portato alla individuazione di un tephra, molto diffuso nell'area, e di un andosuolo su esso sviluppato. il tephra è attribuito, in base alla sua composizione mineralogica, all'eruzione del tufo giallo napoletano (frezzotti & narcisi, 1996). l'eruzione avvenne circa 12.300±300 anni bp (alessio et al., 1973) nei campi flegrei (campania). la ii fase è quindi più recente delle morene formate da ghiacciai con un ela superiore di 200÷280 m rispetto a quella dell’lgm, messe in posto prima della sedimentazione del loess ricco di quarzo, e più antica di circa 12.300 anni bp. lo sviluppo dei rock glacier di tale fase può essere durato 4000-5000 anni. iii fase i rock glacier di questa fase, sono collocati nei circhi glaciali e nelle alte valli, al di sopra dei 1900 m. sono molto meno alterati e vegetati di quelli della ii fase, non sono più coperti dal tephra e dall'andosuolo, e i loro depositi basali possono coprire o essere incassati nelle morene coperte da questi. in una depressione presente su un rock glacier di questa fase è stato trovato un deposito lacustre, datato, alla base, 8035±140 anni (data convenzionale) bp col metodo del radiocarbonio (giraudi & frezzotti, 1997). lo sviluppo dei rock glacier deve essere successivo al tephra databile a circa 12.000 anni bp; si ritiene, quindi, che tale fase di sviluppo coincida con il younger dryas. l'attività di tali rock glacier può essere durata circa 3000 anni. almeno un rock glacier di questa fase coinvolge solo morene databili a circa 14.000 anni fa, ma non è coperto dal tephra o dall'andosuolo: potrebbe essere un rock glacier sviluppatosi nella ii fase, ma rimasto attivo anche nel corso della terza, quindi per un periodo di tempo valutabile a 6000 anni. iv fase i rock glacier di questa fase si trovano a quote superiori a circa 2000 m, nelle alte valli e nei circhi glaciali. non vi sono elementi stratigrafici chiari per distinguerli da quelli della iii fase, ma sono nettamente meno vegetati, perché il suolo superficiale è molto pietroso, e si trovano a quote maggiori. scavando nel deposito, si rinvengono le tracce di un suolo limoso, scomparso dalla superficie, che è stato datato col metodo radiocarbonio ams ed ha fornito un'età convenzionale di 3180±40 anni bp (beta –145529). il suolo è formato in parte da minerali vulcanici, ma non è un andosuolo come quello sviluppatosi sul tephra del tufo giallo napoletano. i minerali provengono da un livello di tephra, non ancora adeguatamente studiato in quanto sottile, mal conservato e fortemente alterato. tale tephra viene chiamato "duchessa", dal nome della montagna sul quale è stato rinvenuto e datato per la prima volta, e copre suoli datati 4390±50 (beta 117017), 4220±80 (beta 106450) e 4020±70 (beta 111004) anni bp. la iv fase è quindi più antica di circa 4000 anni bp, e dovrebbe essere più recente del younger dryas, ma non è chiaro quale sia la sua età reale all'interno di tale lungo intervallo di tempo. non si può escludere che questi rock glacier (o alcuni di essi) si siano sviluppati nella fase precedente ma siano rimasti attivi fino a circa 4000 anni bp. il loro sviluppo potrebbe essere durato 48 giraudi 49i rock glacier tardo-pleistocenici ... quindi 6000-7000 anni bp. v fase i rock glacier di questa fase sono rarissimi, molto piccoli, e si rinvengono a quote superiori a 2270 m: giacciono nelle parte superiori di circhi glaciali, esposti a n e ne, dominati da pareti molto ripide, in zone dove la copertura vegetale è quasi assente. scavando nel deposito, si rinvengono le tracce di un suolo limoso senza minerali vulcanici, scomparso dalla superficie. uno di questi suoli, datato col metodo radiocarbonio-ams ha fornito una età di 780±40 anni bp (beta-145530). lo sviluppo di tale fase è quindi databile tra circa 3180±40 e 780±40 anni bp, in quanto neanche i detriti sui quali si sviluppano sono coperti dal suolo su vulcanico che ha fornito la più antica delle due date (vedasi paragrafo precedente). lo sviluppo dei rock glacier di questa fase può essere durato al massimo attorno ai 2000 anni. mancando ancora studi dettagliati, non è possibile stabilire se il rock glacier che secondo dramis & kotarba (1994) potrebbe essere attivo, sia da attribuire alla v fase o si sia sviluppato in seguito. lo schema cronologico per la datazione delle cinque fasi di sviluppo dei rock glacier è rappresentato in fig. 2. ddiissccuussssiioonnee la maggior parte dei rock glacier si formò tra 20.000 e 10.000 anni bp, quando le temperature erano ancora nettamente inferiori alle attuali (giraudi & frezzotti, 1997), tuttavia la loro distribuzione areale suggerisce alcune importanti considerazioni. nell'appennino settentrionale, (latitudine superiore a 44°n) non sono stati rinvenuti rock glacier, presenti invece a latitudini più meridionali (circa 40°), su montagne di elevazione paragonabile. l’ela durante l’lgm era a quote nettamente inferiori (1300÷1550 m) rispetto a quella del resto dell'appennino (1550÷2100 m). poiché nell’appennino settentrionale, a causa della vicinanza della calotta alpina e del gradiente latitudinale, la temperatura doveva essere un po’ minore rispetto a quella dell’appennino centro-meridionale, l'assenza dei rock glacier deve essere imputata alla diversa quantità di precipitazioni. anche attualmente, le aree più elevate dell'appennino settentrionale ricevono precipitazioni superiori a 1500 mm/anno e in alcuni casi a 2000 mm/anno (ministero dei lavori pubblici, 1968): i valori sono molto più elevati rispetto a quelli della maggior parte della porzione centro-meridionale della catena. si ipotizza che l'assenza di rock glacier sia stata causata dalle abbondanti precipitazioni nevose che proteggevafig. 2 distribuzione, inquadramento cronologico, altitudine e latitudine dei rock glacier dell'appennino. distribution, chronological framework, altitude and latitude of the apennine rock glaciers. 50 giraudi no il suolo dalla penetrazione del gelo. nell'appennino centrale, la porzione occidentale risulta priva di rock glacier; i resti glaciali indicano che in tale zona l ’ela durante l ’lgm era più bassa (1550÷1700 m) rispetto al resto (1600÷2100 m). non si possono invocare differenze di temperatura dovute alla latitudine. per quel che riguarda la possibile influenza del mare sul clima locale, si può ipotizzare che il mare tirreno mitigasse le temperature della porzione occidentale, mentre il mare adriatico, che in periodo glaciale aveva un’estensione molto più ridotta dell’attuale (fig. 1) non poteva fare altrettanto sulla porzione orientale della catena. questa doveva risultare, quindi, più fredda. la bassa quota di ela nella porzione occidentale, deve essere stata causata dalle maggiori precipitazioni. anche attualmente (ministero dei lavori pubblici, 1968) nelle zone più elevate della porzione occidentale le precipitazioni (> di 1500 e per alcune zone > di 2000 mm/anno) superano abbondantemente quelle del resto dell'appennino centrale (< 1500 mm/anno). anche in questo caso l'assenza di rock glacier potrebbe essere stata causata dalle abbondanti precipitazioni nevose che proteggevano il suolo dalla penetrazione del gelo. nell'appennino meridionale, si nota che non vi sono rock glacier nel massiccio (m. sirino) che aveva l’ela più basso (1600 m) durante l’lgm e che anche attualmente (ministero dei lavori pubblici, 1968) ha una elevata piovosità (>2000 mm/anno). un rock glacier è presente invece sul m. pollino, il più meridionale dei due massicci, che aveva un ela durante l’lgm a 1800 m e che attualmente riceve una quantità di precipitazioni <1500 mm/anno (ministero dei lavori pubblici, 1968):. la quota minima alla quale si trovano i rock glacier nell'appennino centrale è inferiore di 80 m rispetto a quella dell'appennino meridionale. anche se dal punto di vista statistico questo dato potrebbe non essere significativo, non si può escludere che tale differenza possa essere dovuta al gradiente latitudinale di temperatura, visto che in entrambe le zone i rock glacier giacciono prevalentemente su versanti esposti verso i quadranti settentrionali. considerando l'importanza dell'entità delle precipitazioni nella distribuzione geografica dei rock glacier, si è provato a vedere se l'influenza dell’umidità è stata importante nel corso di tutto i l periodo di tempo esaminato. fig. 3 confronto tra le oscillazioni di livello del lago del fucino e le fasi di sviluppo dei rock glacier. comparison between the lake fucino oscillations and the age of the phases of rock glaciers development. fig. 4 confronto tra lo sviluppo dei rock glacier e l'estensione dei ghiacciai dell'appennino. comparison between rock glaciers development and the apennine glacier extent. per valutare le variazioni di umidità nell'appennino centrale è stata presa in considerazione la curva delle oscillazioni di livello del lago fucino, posto al centro dell'area in esame. il lago fucino, bonificato nel xix secolo, era un lago senza emissario, soggetto a forti variazioni di livello dovute a cause climatiche (giraudi, 1998e). si assume che il bilancio idrologico del lago sia 51i rock glacier tardo-pleistocenici ... indicativo delle variazioni di umidità nella zona. in fig. 3 è riportata, insieme alla curva delle oscillazioni di livello del lago, la distribuzione temporale delle fasi di sviluppo dei rock glacier. e' possibile dedurre che: le prime tre fasi si verificano in corrispondenza di periodi di basso livello lacustre, quindi di scarsa umidità; la iv fase, di durata mal determinabile, potrebbe essere contemporanea sia a periodi di livello del lago basso che medio-alto; la v fase corrisponde ad un periodo di forti oscillazioni di breve durata: anche in questo caso la risoluzione temporale non è abbastanza dettagliata da permettere una correlazione più precisa; un dato solo è certo, che questa fase è precedente al periodo di massima umidità, corrispondente alla piccola età glaciale. nel complesso si può assumere che le varie fasi di sviluppo dei rock glacier siano identificabili con i periodi più aridi degli ultimi 20.000 anni o, almeno, non coincidano con i più umidi. il numero di rock glacier per ciascuno di tali periodi è invece funzione della temperatura, essendo molto più abbondanti nel corso dell’lgm e del tardiglaciale. altre informazioni derivano dal contronto tra le fasi di sviluppo dei rock glacier e le fasi glaciali. schematizzando (fig. 4) le modifiche dell'estensione dei ghiacciai nell'appennino centrale e paragonandole al numero approssimato di rock glacier, si nota che il numero tendeva a salire mentre i ghiacciai si riducevano. al contrario, nell'olocene, vi erano rock glacier quando i ghiacciai erano assenti: il loro numero si ridusse però quando il ghiacciaio del calderone si riformò (a partire da circa 4000 anni bp) e si espanse. potrebbe esserci una contrapposizione tra fasi di sviluppo dei ghiacciai e dei rock glacier. ccoonncclluussiioonnee nella catena appenninica sono presenti circa 40 rock glacier databili agli ultimi 20.000 anni, sviluppatisi in cinque diverse fasi, l'ultima delle quali tra circa 3000 e 780±40 anni bp; nel corso dell’lgm si formarono i rock glacier alle quote inferiori, il maggiore sviluppo si ebbe nelle fasi tardiglaciali. i rock glacier si sono sviluppati maggiormente su quei massicci caratterizzati da un ela durante l’lgm non molto bassa: l'intero appennino settentrionale ed i massicci che avevano un ela basso, e che attualmente sono soggetti a precipitazioni molto più elevate, ne sono risultati privi. inoltre i rock glacier si sviluppavano per lo più nel corso delle fasi climatiche aride o non molto umide. dalla distribuzione areale dei rock glacier si deduce che, durante le fasi finali dell’lgm, nel tardiglaciale e nell'olocene iniziale, c'è stata, oltre che una migrazione verticale, anche uno spostamento verso nord del limite della loro area di distribuzione: quindi il limite del permafrost montano è passato da 39°55'n a 41°45'n e poi a 42°07'n. in seguito ci fu soltanto una migrazione verticale, in quanto nel tardo olocene i rock glacier hanno potuto svilupparsi solo sulle parti sommitali dei due massicci più elevati. rreeffeerreenncceess alessio m., bella f., improta s., cortesi c. & turi b. (1973) university of rome carbon -14 dates, ix. radiocarbon, 15, 165-178. boenzi f. & palmentola g. (1971) tracce della glaciazione würmiana sul massiccio del pollino al confine calabro-lucano. boll. soc. geol. it., 90, 139-150. braschi s., del freo p. & trevisan l. (1986) ricostruzione degli antichi ghiacciai sulle alpi apuane. atti società toscana di scienze naturali, ser. a, 93, 203-219. damiani a.v. & pannuzi l. (1979) la glaciazione würmiana nell'appennino laziale-abruzzese (5) : i ghiacciai dei m. simbruini (campo ceraso, valle monazzone, fiumata, valle granara) e considerazioni di tettonica recente. mem. descr. carta geol. d'it., 38, 215-250. damiani a.v. & pannuzi l. (1993) la glaciazione pleistocenica nell'appennino laziale-abruzzese. nota vi: i ghiacciai del gruppo del m. greco e considerazioni di tettonica recente. boll. serv. geol. d'it., cx, 111-158. dramis f. & kotarba a. (1994) geomorphological evidences of high mountain permafrost in central apennine. geogr. fis. din. quat., 17, 29-36. federici p.r. (1979) una ipotesi di cronologia glaciale wurmiana, tardo e post-wurmiana nell'appennino centrale. geogr.fis.din.quat.,2, 196-202. federici p.r. (1981) the quaternary glaciation on the seaward side of the apuan alps. rivista geografica italiana, 88 (2), 183-199. federici p.r. & tellini c. (1983) la geomorfologia dell'alta val parma (appennino settentrionale). rivista geografica italiana, 90 (3-4), 393-428. fiucci a., gigante b., rossi c., smiraglia c. & veggetti o. (1997) the calderone glacier (gran sasso d'italia). determination of ice thickness and bedrock morphology by means of radio-echo sounding. geogr. fis. dinam. quat., 2200, 305-308. frezzotti m. & giraudi c. (1990) late glacial and holocene aeolian deposits and features near roccaraso (abruzzo, central italy). quaternary international, 5, 89-95. frezzotti m. & narcisi b. (1996). late quaternary tephra-derived paleosols in central italy's carbonate apennine range: stratigraphical and paleoclimatological implications. quaternary international 3436, 147-153. gellatly a.f., smiraglia c., grove j.m. and latham r. (1994). recent variations of ghiacciaio del calderone, abruzzi, italy. journal of glaciology. 4400, 486-490. ghisetti f. and vezzani l. (1990). carta geologica del gran sasso d'italia (da vado di corno al passo delle capannelle). cartografia s.el.ca., firenze. giraudi c. (1988) segnalazione di scarpate di faglia post-glaciali nel massiccio del gran sasso (abruzzo): implicazioni tettoniche, rapporti tra tettonica recente e morfologia, paleosismicità. mem. soc. geol.it., 41,627-635. giraudi c. (1996) l'impronta del "younger dryas" e degli "heinrich events" nell'evoluzione climatica e ambientale dell'italia centrale. il quaternario, 9(2), 533-540. giraudi c. (1997a) dating and correlation of glacial deposits using tephra layers and loess: the example of m. matese (campania-molise) southern italy. studia geomorphologica carpathobalcanica. xxxi, 45-56. giraudi c. (1997b) prima segnalazione dell'apparato glaciale del m. breccioso (val roveto abruzzo): un contributo all'inquadramento cronologico delle fasi glaciali tardo-pleistoceniche. il quaternario, 10(2), 201-206. giraudi c. (1998a) il glacialismo tardo-pleistocenico del massiccio del terminillo (lazio appennino centrale). il quaternario, 11 (1), 121-125. giraudi c. (1998b) the late quaternary geologic evolution of campo felice (abruzzo central italy). giornale di geologia, sez. 3, 60, 67-82. giraudi c. (1998c) nuovi dati sul glacialismo della montagna della maiella (abruzzo-italia centrale). il quaternario, 11(2), 265-271. giraudi c. (1998d) la deglaciazione tardopleistocenica sui m. sirino e pollino (basilicata, calabria-italia meridionale). il quaternario, 11(2), 247-254. giraudi c. (1998e) late pleistocene and holocene lake level variations in fucino lake (abruzzo central italy) inferred from geological, archaeological and historical data. esf workshop "palaeohydrology as reflected in lake-level changes as climatic evidence for holocene times". palaoklimaforschungpalaeoclimate research, 2255, 1-18, gustav fisher verlag ed. giraudi c. (2000) le oscillazioni oloceniche del ghiacciaio del calderone, gran sasso d'italia (abruzzo italia). il quaternario, 13(1/2), 31-38. giraudi c. (in press) segnalazione di suoli a strisce parallele (sorted stripes) sul gran sasso d'italia (abruzzo). il quaternario. giraudi c. & frezzotti m. (1997) late pleistocene glacial events in the central apennine, italy. quaternary research, 48 (3),280-290. gruppo ricerca geomorfologia c.n.r. (1982) geomorfologia del territorio di febbio tra il m. cusna e il f. secchia (appennino emiliano). geogr.fis. din. quat., 5, 285-360. hamilton s.j. & whalley w.b. (1995) – rock glacier nomenclature: a reassesment. geomorphology, 14, 73-80. jaurand e. (1994) les heritages glaciaire de l'apennin. thèse pour le doctorat dès lettres de l'université de paris i panthéon-sorbonne. 600 pp. ministero dei lavori pubblici (1968) – carta della precipitazione media annua in italia per il trentennio 1921-1950. consiglio superiore servizio idrografico, pubbl. n. 24 (14). palmentola g. & acquafredda p. (1983) gli effetti dei ghiacciai quaternari sulla montagna del matese, al confine molisano-campano. geogr. fis. dinam. quat., 66, 117-130. palmentola g., acquafredda p. & fiore s. (1990) a new correlation of the glacial moraines in the southern appennines, italy. geomorphology, 3, 18. sacco f. (1908) glacialismo ed erosione nella majella. atti soc. it. sc. nat., 4477, 269-280. smiraglia c. & veggetti 0. (1992) recenti osservazioni sul ghiacciaio del calderone (gran sasso d'italiaabruzzo). boll. soc. geogr. it., ser.xi, 44, 269-302. 52 ms. ricevuto il 6 novembre 2001 testo definitivo ricevuto il 19 marzo 2002 ms. received: november 6, 2001 final text received: march 19, 2002 giraudi available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 37 (2), 2024, 113-125 once widespread group (even reaching north america) that differed from the coeval and following hyenas inhabiting europe in a series of anatomical features, from the more trenchant dentition to the slenderer limbs, which indicate a greater propension to active hunting (berta, 1981; kurtén & werdelin, 1988; ferretti, 1999; antón et al., 2006; turner, 2009; tseng et al., 2011, 2013; pérezclaros et al., 2021; konidaris, 2022; marciszak et al., 2022; iannucci, 2024a). all other european hyenas recorded during the pleistocene are regarded as “bonecrackers”, being closely related and aligning morphologically to three out of four of the extant species (turner & antón, 1996; iannucci et al., 2021, 2022; lewis & werdelin, 2022; pérez-claros, 2024), the exception being the aardwolf, a specialized termite-eater belonging to a divergent clade (kruuk & sands, 1972; cooper & skinner, 1979; werdelin & solounias, 1991; westbury et al., 2021; rajmil et al., 2023). the bone-cracking hyenas known from the pleistocene of europe are pliocrocuta perrieri (croizet & jobert, 1828), pachycrocuta brevirostris (gervais, 1850), ‘hyaena’ prisca de serres et al., 1828, and crocuta kaup, 1828 – the latter either assigned altogether to the same taxon of the extant spothttps://doi.org/10.26382/amq.2024.08 1. introduction hyenas (hyaenidae, carnivora) are a group of large mammals today greatly reduced in diversity and geographic distribution, being represented by only four living species mainly limited to africa, except for the striped hyena hyaena hyaena (linnaeus, 1758), which is also present west of africa up to the indian subcontinent (kasparek et al., 2004; akash et al., 2021; hadad et al., 2023; wilkinson et al., 2024). this is in sharp contrast with the large number of species and “ecomorphs” known from the miocene fossil record (e.g., kurtén, 1956; howell & petter, 1980; qiu, 1987; werdelin & solounias, 1991, 1996; semenov, 2008; turner et al., 2008; tseng et al., 2013; coca-ortega & pérez-claros, 2019; morlo et al., 2019; pérez-claros & coca-ortega, 2020; koufos, 2021; iurino et al., 2022; kargopoulos et al., 2023a, 2023b). although the decrease in the diversity and distribution of hyenas was already evident in the pleistocene, hyenas were still present in europe at the time with several species. the so-called “hunting hyena” chasmaporthetes lunensis (del campana, 1914) was the last representative of a the hyena den of cueva victoria (late early pleistocene, spain): additional evidence of the activity of pachycrocuta brevirostris and a discussion on hyenas foraging on seals in the pleistocene of mediterranean europe eulalia garcía-nos 1 , alessio iannucci 2 , francesc ribot trafí 3 , raffaele sardella 4,5 1 universidad nacional de educación a distancia (uned cartagena), cartagena, spain. 2 department of geosciences, section of terrestrial palaeoclimatology, eberhard-karls-university, tübingen, germany. 3 tanzania institute of paleosciences (tips), dodoma, tanzania. 4 dipartimento di scienze della terra, università di roma sapienza, rome, italy. 5 igag-cnr, rome, italy. corresponding author: <eulalia.garcia@cartagena.uned.es> abstract: cueva victoria is a paleontological site of late early pleistocene age (ca. 0.9 ma) located in the southeast of the iberian peninsula (cartagena, region de murcia), which yielded diverse and abundant fossil remains, especially of large mammals. this accumulation is regarded as mainly deriving from the action of the giant hyena pachycrocuta brevirostris, which used the cave as a den. here, we present some preliminary taphonomic information deriving from the study of a portion of the large mammal collection from cueva victoria, including formerly uncatalogued material collected since the 1980s, which has not been considered in previous research. the study of this material started in 2018, when, owing to a suspension of the excavation activities in the cave, permissions were obtained to examine the uncatalogued specimens recovered during previous campaigns. alongside a large number of remains of terrestrial mammals such as equids and cervids, pachycrocuta brevirostris carried into the cave remains of groups uncommon in continental settings, such as marine mammals (cetaceans, seals). beginning with the description of the seal remains of cueva victoria (assigned to monachus sp.), with then discuss the relevance of hyena-seal interactions in the pleistocene of europe in terms of ecology, as well as of seal documentation in the fossil record. from a critical review of the available evidence, cueva victoria stands out as a clear example of the consumption of seal by hyenas, with another likely case being represented by the much younger site of lunel-viel (late middle pleistocene, france). in other known cases of cooccurrence of hyenas and seals, the presence of seals is either due to other factors (e.g., hominins, deposition of marine sediments) or its origin cannot be ascertained for sure. keywords: crocuta crocuta; ‘hyaena’ prisca; monachus monachus; phocidae; epivillafranchian. mailto:eulalia.garcia@cartagena.uned.es ted hyena, c. crocuta (erxleben, 1777), or separated in multiple (sub)species (e.g., bonifay, 1971; schütt, 1971; sardella & petrucci, 2012; lewis & werdelin, 2022). all these species share remarkably similar proportions in their dentition, apart from crocuta, which mainly differs from the others in having a relatively elongated carnassial (iannucci et al., 2021; lewis & werdelin, 2022; pérez-claros, 2024). indeed, several authors placed pliocrocuta perrieri and pachycrocuta brevirostris in the same genus (i.e., pachycrocuta kretzoi, 1938) (qiu et al., 2004; liu et al., 2021), and it has been argued even for ‘hyaena’ prisca (pérezclaros, 2024). in any case, bone-cracking hyenas are documented throughout the european pleistocene. pliocrocuta perrieri endured the equus event (iannucci & sardella, 2023) and survived until at least ca. 1.8 ma, chronologically overlapping with the earliest representatives of the giant hyena p. brevirostris (iannucci et al., 2022). pachycrocuta brevirostris is then widely documented for the rest of the early pleistocene, until ca. 0.8 ma in europe, when crocuta and ‘h.’ prisca dispersed in the region (iannucci et al., 2021). the bioevents represented by the appearance and disappearance of bone-cracking hyenas from the fossil record of europe are considered of great biochronological significance, especially for the faunal turnovers of the middle villafranchian-late villafranchian – with the spread into europe of p. brevirostris – and of the epivillafranchian-galerian – with the local extinction of p. brevirostris and the arrival of crocuta and ‘h.’ prisca(palombo et al., 2008; martínez-navarro, 2010; iannucci et al., 2021, 2023; croitor et al., 2024; konidaris & kostopoulos, 2024; spassov, 2024). for instance, during the 1.2-0.9 ma time span, around the jaramillo subchron, a marked faunal turnover followed the shift of the climate from 41 ka obliquity orbital cycles to a highly non-linear system dominated by a 100 ka periodicity with asymmetric glacial/ interglacial cycles (clark et al., 2006). the faunal assemblages of this time span (1.2-0.8 ma) are assigned to the epivillafranchian biochron (bellucci et al., 2015), which includes among the others untermassfeld in germany, le vallonnet in france, colle curti, scoppito/ madonna della strada and slivia in italy, trinchera elefante and vallparadís estació in spain. the c. crocuta event marks the end of this biochron and represents a further renewal in european faunas, when most of the villafranchian large carnivores became extinct. the severe glaciation of the “0.9 ma event” might have been particularly influential in promoting the observed changes in the mammalian fauna (head & gibbard, 2015; strani et al., 2019; strani, 2021). in the italian fossil record, the large mammal assemblage of slivia includes the latest occurrence of the giant hyena p. brevirostris, while the occurrence of c. crocuta is documented at casal selce 1 (rome, ca. 0.75-0.7 ma; sardella & petrucci, 2012). this agrees with what is known in spain, where the replacement between p. brevirostris and c. crocuta (and roughly ‘h.’ prisca) is documented ca. 0.8 ma with the appearance of the latter in the stratigraphic section of gran dolina (garcía & arsuaga, 2001; iannucci et al., 2021; gibert et al., 2024). bone-cracking hyenas are responsible for mass accumulations of bones, which are of fundamental importance for gaining insights into pleistocene ecosystems (e.g., kuhn et al., 2010; mangano, 2011; fourvel et al., 2015). here, we present some preliminary taphonomic information deriving from the study a portion of the large mammal collection from the late early pleistocene site of cueva victoria (cartagena, spain) which has not been considered in previous research. at cueva victoria, the giant hyena p. brevirostris played a major role in the fossil accumulation, besides carrying into the cave remains of groups uncommon in terrestrial deposits, such as marine mammals. beginning with the case of the presence at cueva victoria of seal remains related to the monk seal, (monachus fleming, 1822), of which we provide a description, with then discuss the relevance of hyena-seal interactions in the pleistocene of europe in terms of ecology, as well as of seal documentation in the fossil record. 2. cueva victoria cueva victoria is a paleontological site located in the mining sierra de la unión, in the cerro de san ginés de la jara, near the towns of the strait of san ginés and the llano del beal, in cartagena (se spain) (fig. 1). the karstic origin of cueva victoria led to the formation of cavities that opened to the outside during the early pleistocene (vilá-vinyet et al., 2015). as a consequence, the cave was filled with sediment from the outside through several entrances, forming the fossil gap continuously until it was filled (ferràndez et al., 1989; gibert et al., 2006). it was during this filling time interval that the hyena pachycrocuta brevirostris used it as its den. after total clogging, the cave was sealed, producing a cementation process due to the calcium carbonate contained in the runoff water that was entering, forming a speleothem layer (gibert et al., 2016). 114 garcía-nos e. et al. fig. 1 geographic location of the late early pleistocene paleontological site of cueva victoria. mammals. the cave was interpreted as a den of hyenas after studying various aspects that left no room for doubt, such as: the presence of milk teeth of p. brevirostris, the abundance of accumulated coprolites of hyenas, the presence of the aforementioned marine fauna, bones digested and the enormous amount of remains with different tooth marks and fractures resulting from the action of these carnivorans (gibert et al., 1992). in this sense, the splinters and fragments of bones of different sizes stand out. the review of the material has also revealed the presence of marks on a large part of the abundant number of splinters in the fossil collection deposited in the museo arqueológico municipal enrique escudero de castro, in cartagena. these marks provide information of taphonomic value that complements that of the whole bones (garcía-nos & ribot trafí, 2021). 3. materials and methods we studied 4235 complete or (mainly) fragmented skeletal elements of medium and large size (> 2 cm for bone fragments), part of the fossil collection of cueva victoria, housed in the museo arqueológico municipal enrique escudero de castro, in cartagena. the study of this material started in 2018, when, owing to a suspenthe deposit is altered by the action of the miners, who, looking mainly for manganese, destroyed a good part of the fossiliferous breccia. in this way, the original cave underwent modifications and large blocks can be seen, which fell from the ceiling and contain a breccia, as a result of the use of explosives. therefore, it is a cave that in turn is a mine exploited from the end of the 19th century to the middle of the 20th century, approximately (pérez de perceval et al., 2015). at the beginning of the 1980s, systematic paleontological excavations began at cueva victoria, which is dated at ca. 0.9 ma (gibert et al., 2016). the site presents one of the best records of fossil fauna from the european early pleistocene, with approximately one hundred identified vertebrate species (gibert & ferràndez-cañadell, 2015), mainly due to its condition as a den for the hyena p. brevirostris (gibert et al., 1992). it is also noteworthy that taxa new to science have been discovered in cueva victoria, such as the lagomorph oryctolagus giberti de marfà, 2008, the arvicolid victoriamys chalinei martin, 2012, and the giant deer megaloceros novocarthaginiensis van der made, 2015. another matter of great importance is the presence in the cavity of remains of primates of african origin; in different excavation campaigns, a total of five teeth belonging to theropithecus oswaldi were found, constituting to date the only place in europe where fossils of this primate have been found (gibert et al., 1995, 1999; ferràndez-cañadell et al., 2014; ribot et al., 2015; martínez et al., 2020). rook et al. (2004) cited the presence of this taxon in the pirro nord site represented by three cervical vertebrae, which caused some discussion (patel et al., 2007; rook & martínez-navarro, 2013), eventually settled in 2014 with the publication of alba et al. (2014), who showed that they were three vertebrae of hystrix refossa, an abundant porcupine in this site. on the other hand, a second phalanx of the fifth finger of the right hand was also found, classified as homo sp. (cv-0) (gibert 1985; gibert and pons-moyà, 1985; pons-moyà, 1985; gibert et al., 2008; ribot et al., 2015). another peculiarity within the abundance and diversity of taxa in cueva victoria is the fossil record of marine fauna. the cave is currently about 3.3 km from the sea. according to the study by goy et al. (1990) during the early pleistocene the coastline would be similar to the current one, although with a different morphology; therefore, the sea could never invade the cave. inside the cavity, four vertebral centra belonging to an indeterminate cetacean were found, as well as an incomplete hemimandible and a fragment of monk seal maxilla initially cited as a sirenid (gibert et al., 1992) and later assigned to the genus monachus (gibert et al., 1999; ferràndez-cañadell, 2015). the fact that the seal hemimandible is bitten at its proximal end confirms its transport to the interior of the cavity by hyenas, which did not limit their hunting-scavenging activity to land 115 cueva victoria and hyena-seal records in pleistocene europe fig. 2 distribution of the number of identified specimens (nisp) of the studied mammal remains from cueva victoria by taxonomic group. sion of the excavation activities in the cave, permissions were obtained to examine the uncatalogued specimens recovered during previous campaigns (garcía-nos et al., 2020). we considered only large mammal remains, excluding lagomorphs and smaller species. given the fragmentary nature of the studied material, taxonomic identifications and considerations are limited to the family or order level. nomenclature, taxonomy, and comparative discussion on the seal remains of cueva victoria is mainly based on scheel et al. (2014) and berta et al. (2015), including reference to the fossil species pliophoca etrusca tavani, 1941 and the extant monk seals monachus monachus (hermann, 1779) and neomonachus slater & helgen, 2014 (in scheel et al., 2014). 4. results of the total sample of 4235 specimens considered in this work, 906 (21.4%) remains have been anatomically and taxonomically identified (fig. 2). isolated and fragmented teeth account for 46% (n = 417) of the total, primarily belonging to equids (n = 310). mandibular fragments are not abundant (n = 26; 2.9%), while maxillae and cranial remains are totally absent. there are 63 vertebrae (only 5 of which are roughly complete) and 13 costae. distal epiphyses of metapodials are the most common skeletal element (n = 199), with other fragments of bones being represented by astragali (n = 53), calcanei (n = 46), proximal tibiae (n = 23), proximal radii (n = 16), femoral shafts (n = 12), and rotulas (n = 7), with equid specimens being dominant and several indeterminate remains belonging to middle-sized ungulates. complete bones are quite limited in the sample, including only small elements such phalanges (n = 25), calcanei (n = 6), and one cervid astragalus. signs of the activity of hyenas are observable in 76% of the 4235 remains, including w-shaped fractures, corrosion due to digestion, and tooth marks of large size (pits of 7-10 mm) (fig. 3). there is no evidence of cut marks or other traces potentially indicating an anthropic influence on the accumulation. those specimens where signs of the activity of carnivorans are not recorded are generally those whose size or preservation preclude a clear evaluation. 5. systematic paleontology family phocidae gray, 1825 subfamily monachinae gray, 1869 tribe monachini gray, 1869 monachus fleming, 1822 monachus sp. (fig. 4) 5.1. description the presence of seals at cueva victoria is documented by two specimens, a right maxilla (cv-mc-67) and a left hemimandible (cv-mc-66). both specimens are in good state of preservation (the maxilla better) and belong to adult individuals with differentially worn teeth. postcanine teeth are formed by a large single central cusp/cuspid, with accessory cuspules/cuspulids better fig. 3 example of bone fragments from cueva victoria showing traces of the activity of hyenas (museo arqueológico municipal enrique escudero de castro, cartagena). arrows point to some large pits. photos: eulalia garcía-nos. 116 garcía-nos e. et al. victoria (and le vallonnet). pliophoca etrusca is closely related to extant monk seals and shares a large number of morphological traits with m. monachus (berta et al., 2015). in these species (including material assigned to pliophoca cf. etrusca by berta et al., 2015) and in the seal of cueva victoria, premolars are large, oriented obliquely, and separated by short diastemata, and the mandibular ramus is robust with a wide symphysis. the seal of cueva victoria differs from p. etrusca and neomonachus in the more crowded positioning and the related more oblique orientation of postcanine teeth along the mesio-distal axis of the tooth row, also resulting in a larger overlap (especially) between p2 and p3. collectively, the morphological features observable on the seal remains from cueva victoria point to an attribution to monachus and most likely to the mediterranean monk seal m. monachus, although, since the available sample does not allow us to evaluate traits which have been considered diagnostic for the identification of the species in previous studies (scheel et al., 2014; berta et al., 2015), we favor an assignment to monachus sp. 6. discussion considering the richness of the fossil record of cueva victoria, in terms of diversity and number of remains, it is not surprising that the material studied herein has not been included in the latest systematic revision of the locality (gibert & ferràndez-cañadell, 2015), but it allowed us to complement previous information on the expressed distally. these teeth are oriented obliquely with respect to the mesio-distal axis of the tooth row. they are separated by diastemata, which are shorter in the maxilla, so that teeth overlap in lateral view. in the maxilla, p1 is broken but the rest of the postcanine dentition is preserved. p1 would have been placed very close to the upper canine and lingually to it. p2, p3, and p4 are large (the latter less than the others) and worn, while m1 is markedly smaller and less worn than the premolars, preserving a pointed cusp with more evident vertical striae that connects it to the cingulum. in the hemimandible, i2 is broken, while the specimen preserves i1, a large canine, and four postcanine teeth (p1p4). the mandibular ramus is robust with a wide symphysis. premolars are large (but p1 is smaller) but preservation and wear do not always allow us to evaluate the finer morphological details. the last premolar, p4, has clear accessory cuspulids and a marked lingual cingulum. 5.2. remarks the fossil record of seals is rather patchy in time and space (valenzuela-toro & pyenson, 2019). in particular, apart from some monachine remains of uncertain taxonomic placement, an important gap (ca. 2 ma) separates the holotype partial skeleton of pliophoca etrusca of the late pliocene (piacenzian) of casa nuova, orciano pisano (tuscany, italy; berta et al., 2015) from the late early pleistocene occurrence of monachus at cueva 117 fig. 4 seal remains (monachus sp.) from cueva victoria, including a right maxilla cv-mc-67 (a) figured in occlusal (a1) and buccal (a2) views and a left mandible cv-mc-66 (b) figured in occlusal (b1) and lingual (b2) views (museo arqueológico municipal enrique escudero de castro, cartagena). photos: miguel camino and eulalia garcía-nos. cueva victoria and hyena-seal records in pleistocene europe 118 site while promoting the valorization of its important museum collection. we refrain from detailed taphonomic considerations, as the studied material represents a sub -sample, besides biased towards elements regarded as least significant (hence uncatalogued) in previous research, of the large mammal assemblage known from the site. for instance, equids are abundant at cueva victoria (alberdi & piñero, 2015) but proportionally even more in the studied sample, probably because there are several remains which are not diagnostic at a species level – and therefore could belong to one or the other of the two species present at the site (alberdi & piñero, 2015). the majority of the remains revealed traces of the activity of carnivorans and, when this is not verified, it is generally limited to the smallest and least preserved specimens, corroborating the view that the giant hyena pachycrocuta brevirostris was the primary agent responsible for the accumulation of large mammal remains (gibert et al., 1992). indeed, some species recorded at cueva victoria evidently did not live in the cave, but their remains were carried inside by the hyenas. most notably, this is the case with marine mammals such as cetaceans (of which some vertebrae are known) and seals (fig. 4; ferràndez-cañadell, 2015). the latter offer the occasion to discuss of the potential prey-acquisition-strategy adopted by hyenas when foraging on seals, that is, to attempt to evaluate whether hyenas actively hunted seals, at cueva victoria and other pleistocene sites, or they just scavenged carcasses available in the surrounding. today, the populations of brown hyena, parahyaena brunnea (thunberg, 1820) that live along the namibian coast offer an interesting case study, as they indeed actively hunt seals, otherwise being primarily scavengers (mills, 1982, 1990; wiesel, 2006). however, although seals represent the main food source for the brown hyenas of the coast of namibia, they rely on a wide range of resources, and active hunting is mainly directed towards seal pups, while not disregarding the ingestion of carrions (skinner et al., 1995; wiesel, 2006; kuhn et al., 2008). it is also worth noting that namibian seal colonies represent a resource abundant and available all year round (though with seasonal fluctuations) in an otherwise challenging and unproductive environment, with the namib desert on the background. in this situation, brown hyenas adapted to habitually forage on seals, with a greater proportion of killings than observed elsewhere in other populations of the species, and besides also modified their period of activity, being active during day and night, while the species is usually mainly nocturnal (skinner et al., 1995; wiesel, 2006; kuhn et al., 2008). the fossil assemblage of cueva victoria suggests a rather different context. the variety of species recorded at the site indicates, on one hand, the diversity of habitats that were present in the area (e.g., blain, 2015; furió, 2015; sánchez marco, 2015; garcía-nos et al., 2023) and, on the other, that the populations of p. brevirostris did not specialize in the consumption of one or few species. considering the large mammals, cueva victoria offers a wide picture of the fauna of the late early pleistocene of europe, besides including some unique elements such as theropithecus oswaldi. indeed, apart from relatively rare groups such as suids (iannucci, 2024b), other absences, for instance, that of hippopotamuses (ferràndez-cañadell, 2015) are probably of paleocological significance. in this context, though it is impossible to state it for sure, it seems more likely that the seal remains recovered from cueva victoria derived from carcasses exploited by hyenas, rather than from actively hunted individuals. perhaps, benefiting from a favorable beaching, as is certainly the case with the cetacean remains. the occurrence of seal remains referable to the genus monachus is documented in the pleistocene of mediterranean region in a few sites. apart from cueva victoria, another site of late early pleistocene age that yielded seal remains is the cave of le vallonnet, along the southern coast of france (de lumley et al., 1963; 1988). as for cueva victoria, the vallonnet cave is interpreted has been used as den by hyenas, but also other carnivorans and, most importantly, hominins were also present at the site, as documented by a series of more than 100 lithic pieces and some bones with anthropogenic traces (echassoux, 2004; michel et al., 2017; cauche, 2022). in any case, neither hominins nor hyenas were probably responsible for carrying seal remains inside the cave at le vallonnet, as the occurrence of monachus is limited to the stratigraphic ensemble ii recognized by the authors, and this unit consists of marine sands which documents the passage of the sea inside the cave (echassoux, 2004; michel et al., 2017; cauche, 2022). a rather long chronological gap separates the findings from cueva victoria and le vallonnet from the following seal occurrences in the european mediterranean, which are known from late middle pleistocene sites. one of these, which is not so far from le vallonnet, is lunelviel, from which brugal et al. (2021) reported the presence of three seal teeth assigned to cf. phoca sp.?; here, however, the faunal assemblage comes entirely from continental deposits, hence suggesting that hyenas were responsible for the accumulation of seal remains (brugal et al., 2021). at lunel-viel, the remains of hyenas are quite abundant and two species are part of the faunal assemblage, crocuta crocuta (or c. intermedia, or c. spelaea intermedia, depending on different taxonomic approaches) and ‘hyaena’ prisca (bonifay, 1971; brugal et al., 2021). ‘hyaena’ prisca is the fossil hyena from the pleistocene of europe which is arguably the most intriguing to discuss in relation to the potential foraging on seals. for a start, the species is very close in dental size and proportions to the brown hyena (e.g., iannucci et al., 2021, pérez-claros, 2024), besides, while its fossil record is rather patchy, several occurrences of ‘h.’ prisca are known from sites located not far from the sea, especially in southern france (iannucci et al., 2021). on the other hand, lunel-viel represents the only site where the co-occurrence of ‘h.’ prisca and seals is documented so far (brugal et al., 2021). in general, there is only one other middle pleistocene finding of seal in mediterranean europe, based on a phalanx assigned to monachus monachus recovered during recent excavations at grotta romanelli, in apulia, southeastern italy (mecozzi et al., 2024). recent research at grotta romanelli led to the revision of the garcía-nos e. et al. references akash m., dheer a., dloniak s.m., jacobson a.p. (2021) the faded stripes of bengal: a historical perspective on the easternmost distribution of the striped hyena. european journal of wildlife research, 67, 6, 108. doi: 10.1007/s10344-021-01552-9 alba d.m., colombero s., delfino m., martínez-navarro b., pavia m., rook l. (2014) a thorny question: the taxonomic identity of the pirro nord cervical vertebrae revisited. journal of human evolution, 76, 92-106. doi: 10.1016/j.jhevol.2014.06.005 alberdi m.t., piñero p. (2015) estudio de los caballos del yacimiento de cueva victoria, pleistoceno inferior (murcia). in: geología y paleontología de cueva victoria (eds. gibert l., ferràndezcañadell c.), mastia. revista del museo arqueológico municipal de cartagena “enrique escudero de castro”, 11-13, ayuntamiento de cartagena, cartagena, 325-358. antón m., turner a., salesa m.j., morales j. (2006) a complete skull of chasmaporthetes lunensis (carnivora, hyaenidae) from the spanish pliocene site of la puebla de valverde (teruel). estudios geológicos, 62, 375-388. doi: 10.3989/egeol.0662132 azzaroli a., borselli v., rustioni m. (1990) nuovi ritrovamenti di fossili continentali in alcune isole minori dell’arcipelago toscano. atti della società toscana di scienze naturali, memorie, serie a, 15 -30. bellucci l., sardella r., rook l. (2015) large mammal biochronology framework in europe at jaramillo: the epivillafranchian as a formal biochron. quaternary international, 389, 84-89. doi: 10.1016/j.quaint.2014.11.012 berta a. (1981) the plio-pleistocene hyaena chasmaporthetes ossifragus from florida. journal of vertebrate paleontology, 1(3-4), 341-356. doi: 10.1080/02724634.1981.10011905 berta a., kienle s., bianucci g., sorbi s. (2015) a reevaluation of pliophoca etrusca (pinnipedia, phocidae) from the pliocene of italy: phylogenetic and biogeographic implications. journal of vertebrate paleontology, 35(1), e889144. doi: 10.1080/02724634.2014.889144 blain h.a. (2015) anfibios y escamosos de cueva victoria. in: geología y paleontología de cueva victoria (eds. gibert l., ferràndez-cañadell c.), mastia. revista del museo arqueológico municipal de cartagena “enrique escudero de castro”, 1113, ayuntamiento de cartagena, cartagena, 175198. blanc g.a. (1920) grotta romanelli i. stratigrafia dei depositi e natura e origine di essi. archivio per l’antropologia e la etnologia, 50, 1-39. blanc g.a. (1928) grotta romanelli ii. dati ecologici e paletnologici. archivio per l’antropologia e la etnologia, 58, 1-49. bonifay m.-f. (1971) carnivores quaternaires du sudest de la france. mémoires du muséum national stratigraphic setting and chronology of this site, which played an important role for the correlations of the european late pleistocene (sardella et al., 2018, 2019; mecozzi et al., 2021, 2022, and references therein), revealing an older (i.e., late middle pleistocene) initial frequentation of the cave by hominins and fauna than previously assumed (pieruccini et al., 2022). the new seal finding comes from the late middle pleistocene levels of grotta romanelli (isu2; mecozzi et al., 2024), while previous reports listed the presence of the species from the late pleistocene (isu3) and holocene (isu5) units (blanc, 1920, 1928; sardella et al., 2018; pieruccini et al., 2022). although hyenas, here represented by crocuta, are known from grotta romanelli, their rarity in the fossil assemblage (blanc, 1920, 1928; mecozzi et al., 2024) suggests that they were not responsible for the presence of monachus, but rather other carnivorans or hominins played a role. it is worth mentioning the occurrence of monachus cf. monachus from a fossiliferous breccia recovered on the small island formica di burano (tuscany, italy), which was considered of late pleistocene age based on the presence of continental mammals, namely, cervus elaphus and dama dama (azzaroli et al., 1990). finally, monachus remains are known from several late pleistocene to holocene localities of mediterranean europe, mainly from archaeological sites of mousterian or late glacial-holocene context, for instance, evidence of monk seal hunting by epipalaeolithic humans have been discovered in the nerja cave in spain (moralespérez et al., 2019, and references therein). in brief, conclusive evidence for hyenas foraging on seals in the pleistocene of europe is limited to the activity of p. brevirostris at the late early pleistocene site cueva victoria, with another likely case being represented by the late middle pleistocene of lunel-viel, where either crocuta or ‘h.’ prisca might have been responsible for the consumption. other co-occurrences of hyenas and seals are known (e.g., grotta romanelli), but, although this possibility cannot be ruled out, evidence for the direct interaction between the two groups is currently lacking. still, if not for the action of bone-cracking hyenas, the fossil record of seals (which is biased chronologically and geographically, see valenzuela-toro & pyenson, 2019) in the pleistocene of europe would be even scarcer than it is. the occurrence of monachus at cueva victoria provides robust evidence of the presence of monk seals in the mediterranean since at least the late early pleistocene. acknowledgments we are thankful to the director of the museo arqueológico de cartagena, miguel martín camino, for his support and help in acquiring some of the photos. we are further grateful to the dirección general de patrimonio de la región de murcia for the permission to study the fossil material from cueva victoria. alessio iannucci is supported by a humboldt research fellowship provided by the alexander von humboldt foundation. 119 cueva victoria and hyena-seal records in pleistocene europe cologique et archéozoologique des faunes de grands mammifères de la seconde moitié du pléistocène inférieur de la grotte du vallonnet (roquebrune-cap-martin, alpes-maritimes, france). l’anthropologie, 108, 11-53. doi: 10.1016/j.anthro.2004.01.006 erxleben j.c.p. (1777) systema regni animalis per classes, ordines, genera, species, varietates, cum synonymia et historia animalium. classis 1: mammalia. weygandianis, leipzig. ferràndez c., pérez-cuadrado j.l., gibert j., martínez b. (1989) estudio preliminar de los sedimentos de relleno de cueva victoria (cartagena, murcia). in: los restos humanos de orce y cueva victoria (eds. gibert j., campillo d., garcía olivares e.), publicacions de l’institut de paleontologia dr. m. crusafont, barcelona, 379-393. ferràndez-cañadell c., ribot f., gibert l. (2014) new fossil teeth of theropithecus oswaldi (cercopithecoidea) from the early pleistocene at cueva victoria (se spain). journal human evolution, 74, 55-66. doi: 10.1016/j.jhevol.2014.02.020 ferràndez-cañadell c. (2015) grupos pendientes de estudio o revisión. in: geología y paleontología de cueva victoria (eds. by gibert l., ferràndezcañadell c.), mastia. revista del museo arqueológico municipal de cartagena “enrique escudero de castro”, 11-13, ayuntamiento de cartagena, cartagena, 453-462. ferretti m.p. (1999) tooth enamel structure in the hyaenid chasmaporthetes lunensis lunensis from the late pliocene of italy, with implications for feeding behavior. journal of vertebrate paleontology, 19, 767-770. doi: 10.1080/02724634.1999.10011189 fleming j. (1822) the philosophy of zoology or a general view of the structure, functions, and classification of animals. archibald constable and company, edinburgh. fourvel j.b., fosse p., fernandez p., antoine p.o. (2015) large mammals of fouvent-saintandoche (haute-saône, france): a glimpse into a late pleistocene hyena den. geodiversitas, 37(2), 237-266. doi: 10.5252/g2015n2a5 furió m. (2015) estado de conocimiento de los insectívoros (soricidae, erinaceidae) de cueva victoria. in: geología y paleontología de cueva victoria (eds. gibert l., ferràndez-cañadell c.), mastia. revista del museo arqueológico municipal de cartagena “enrique escudero de castro”, 11-13, ayuntamiento de cartagena, cartagena, 227-238. garcía n., arsuaga j.l. (2001) les carnivores (mammalia) des sites du pléistocène ancien et moyen d'atapuerca (espagne). l'anthropologie 105, 83-93. doi: 10.1016/s0003-5521(01)80007-8 garcía-nos e., ferràndez-cañadell c., ribot trafí f. (2020) revisión del material fósil sin inventariar de cueva victoria. xxvi jornadas de patrimonio cultural de la región de murcia,141-146. garcía-nos e., ribot trafí f. (2021) la evidencia en d’histoire naturelle, paris, n.s., sér. c, 21, 43-377. brugal j.p., giuliani c., fosse p., fourvel j.-p., magniez p., pelletier m., uzunidis a. (2021) preliminary data on the middle pleistocene site of lunel-viel i (hérault, france). alpine and mediterranean quaternary, 34, 1, 75-87. doi:10.26382/amq.2021.08 cauche d. (2022) the vallonnet cave on the northern mediterranean border: a record of one of the oldest human presences in europe. l'anthropologie, 126,1, 102974. doi: 10.1016/j.anthro.2021.102974 clark p., archer d., pollard d., blum j.d., rial j.a., brovkin v., mix a.c., pisias n.g., roy m. (2006) the middle pleistocene transition: characteristics, mechanisms, and implications for long-term changes in atmospheric pco2. quaternary science reviews, 25, 3150-3184. doi: 10.1016/j.quascirev.2006.07.008 coca-ortega c., pérez-claros j.a. (2019) characterizing ecomorphological patterns in hyenids: a multivariate approach using postcanine dentition. peerj, 6, e6238. doi: 10.7717/peerj.6238 cooper r.l., skinner j.d. (1979) importance of termites in the diet of the aardwolf proteles cristatus in south africa. south african journal of zoology, 14,1, 5-8. doi: 10.1080/02541858.1979.11447640 croitor r., robinson c., curran s., terhune c., drăgușin v., pobiner b., popescu d., petculescu a. (2024) early pleistocene ruminants (artiodactyla, mammalia) from the dacian basin (south romania) before and after the pachycrocuta event: implications for hominin dispersals in western eurasia. historical biology, 36, 3, 485533. doi: 10.1080/08912963.2023.2167602 croizet j.-b., jobert a.-c.-g. (1828) recherches sur les ossements fossiles du département du puy-dedome. clermont-ferrand, paris. de marfà r. (2008) oryctolagus giberti n. sp. (lagomorpha, mammalia) from the lower pleistocene of cueva victoria (murcia, spain). comptes rendus palevol, 7, 305-313. doi: 10.1016/j.crpv.2008.03.003 del campana d. (1914) la lycyaena lunensis n. sp. dell'ossario pliocenico di olivola (val di magra). palaeontographia italica, 20, 87-103. de lumley h., gagnière s., barral l., pascal r. (1963) la grotte du vallonnet, roquebrune-cap-martin (a.-m.). bulletin du musée d'anthropologie préhistorique de monaco, 10, 5-20. de lumley h., kahlke h.d., moigne a.m., moullé p.e. (1988) les faunes de grands mammifères de la grotte du vallonnet, roquebrune-cap-martin, alpes-maritimes. l’anthropologie, 92, 465-495. de serres m., dubreuil j., jeanjean b. (1828) mémoires sur les diverses espèces d'hyènes fossiles découvertes dans les cavernes de lunel-vieil (hérault). mémoires du museum national d'histoire naturelle, paris, 17, 269-312. echassoux a. (2004) étude taphonomique, paléoé 120 garcía-nos e. et al. sition of mammalia into tribes and families, with list of the genera apparently appertaining to each tribe. annals of philosophy, new series 10 (volume 26 for entire series), 337-344. doi: 10.1080/00222936908695973 gray j.e. (1869) the sea elephant (morunga proboscidea) at the falkland islands. the annals and magazine of natural history, 4, 400. hadad e., kosicki j.z., yosef r. (2023) population trends of striped hyena (hyaena hyaena) in israel for the past five decades. scientific reports, 13, 1, 3982. doi: 10.1038/s41598-023-31137-2 head m.j., gibbard p.l. (2015) early-middle pleistocene transitions: linking terrestrial and marine realms. quaternary international, 389, 7-46. doi: 10.1016/j.quaint.2015.09.042 hermann j. (1779) beschreibung der münchs-robbe. beschäftigungen der berlinischen gesellschaft naturforschender freunde, 4, 456-509. howell f.c., petter g. (1980) the pachycrocuta and hyaena lineages (plio-pleistocene and extant species of the hyaenidae). their relationships with miocene ictitheres: palhyaena and hyaenictitherium. geobios, 13, 579-623. doi: 10.1016/s0016-6995(80)80004-0 iannucci a. (2024a) ecospace occupancy and disparity in pleistocene large carnivorans of europe and implications for hominin dispersal and ecological role. quaternary science reviews, 329, 108562. doi: 10.1016/j.quascirev.2024.108562 iannucci a. (2024b) the occurrence of suids in the post-olduvai to pre-jaramillo pleistocene of europe and implications for late villafranchian biochronology and faunal dynamics. quaternary, 7, 1, 11. doi: 10.3390/quat7010011 iannucci a., sardella r. (2023) what does the “elephant-equus” event mean today? reflections on mammal dispersal events around the pliocenepleistocene boundary and the flexible ambiguity of biochronology. quaternary, 6, 1, 16. doi: 10.3390/quat6010016 iannucci a., mecozzi b., sardella r., iurino d.a. (2021) the extinction of the giant hyena pachycrocuta brevirostris and a reappraisal of the epivillafranchian and galerian hyaenidae in europe: faunal turnover during the early-middle pleistocene transition. quaternary science reviews, 272, 107240. doi: 10.1016/j.quascirev.2021.107240 iannucci a., cherin m., sardella r. (2022) the lost hyena from paciano (umbria, italy) reconsidered. alpine and mediterranean quaternary, 35, 2, 105117. doi: 10.26382/amq.2022.06 iannucci a., mecozzi b., sardella r. (2023) beware of the “wolf event” remarks on large mammal dispersals in europe and the late villafranchian faunal turnover. alpine and mediterranean quaternary, 36, 1, 75-90. doi: 10.26382/amq.2023.03 iurino d.a., iannucci a., conti j., mecozzi b., sardella r., strani f. (2022) revised description of the los huesos: tipos de marcas en los restos fósiles de cueva victoria (cartagena). xxvi jornadas de patrimonio cultural de la región de murcia, 81-86. garcía-nos e., ribot trafí f., iglesias diéguez a., iannucci a., sardella r., musiba c., lería morillo m. (2023) aproximación al entorno paleoambiental de cueva victoria (cartagena, región de murcia) a través de su registro faunístico. xxix jornadas de patrimonio cultural de la región de murcia, 5762. gervais p. (1850) zoologie et paléontologie françaises. nouvelles recherches sur les animaux vivants et fossiles de la france. tome i. contenant l’énumerération méthodique et descriptive des espèces ainsi que les principes de leur distribution géographique et paléontologique [18481852]. arthus bertrand, paris. gibert j. (1985) estudio morfológico y diagnosis diferencial de la falange del género homo de cueva victoria (cartagena, murcia). actas iv congreso español de antropología biológica. sociedad española de antropología física, barcelona. gibert j. (1999) cueva victoria: puerta de europa. in: the hominids and their environment during the lower and middle pleistocene of eurasia (eds. gibert j., sánchez f., gibert l., ribot f.), museo de prehistoria. ayuntamiento de orce, granada, 229-223. gibert j., pons-moyà j. (1985) estudio morfológico de la falange del género homo de cueva victoria, paleontologia i evolució, 18, 49-55. gibert j., ferràndez c., pérez-cuadrado j.l., martínez b. (1992) cueva victoria: cubil de carroñeros. in: presencia humana en el pleistoceno inferior de granada y murcia (ed. gibert j.), publicaciones del museo de prehistoria de orce, granada,133142. gibert j., leakey m., ribot f., gibert l., arribas a., martínez b. (1995) presence of the cercopithecid genus theropithecus in cueva victoria (murcia, spain). journal of human evolution, 28, 487-493. doi: 10.1006/jhev.1995.1036 gibert j., gibert l., ferràndez c., ribot f., iglesias a., gibert p. (2006) cueva victoria: geología, paleontología, restos humanos y edades. memorias de arqueología región de murcia, 14, 37-62. gibert j., gibert l., ribot f., ferràndez-cañadell c., sánchez f., iglesias a., walker m.j. (2008) cv0, an early pleistocene human phalanx from cueva victoria (cartagena, spain). journal of human evolution, 54, 150-156. doi: 10.1016/j.jhevol.2007.04.010 gibert l., scott g., scholz d., budsky a., ferràndez c., ribot f., martín r., lería m. (2016) chronology for the cueva victoria fossil site (se spain): evidence for early pleistocene afro-iberian dispersals. journal of human evolution, 90,183-197. doi: 10.1016/j.jhevol.2015.08.002 gibert l., scott g., deino a., martin r. (2024) magnetostratigraphic dating of earliest hominin sites in europe. earth-science reviews, 256, 104855. doi: 10.1016/j.earscirev.2024.104855 gray j.e. (1825) an outline of an attempt at the dispo 121 cueva victoria and hyena-seal records in pleistocene europe lewis m.e., werdelin l. (2022) a revision of the genus crocuta (mammalia, hyaenidae). palaeontographica abteilung a: paläozoologie stratigraphie, 322, 1-4, 1-115. doi: 10.1127/pala/2022/0120 linnaeus c. (1758) systema naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. tomus i. editio decima, reformata. laurentius salvius, stockholm. liu j., liu j., zhang h., wagner j., jiangzuo q., song y., liu s., wang y., jin c. (2021) the giant short -faced hyena pachycrocuta brevirostris (mammalia, carnivora, hyaenidae) from northeast asia: a reinterpretation of subspecies differentiation and intercontinental dispersal. quaternary international 577, 29-51. doi: 10.1016/j.quaint.2020.12.031 mangano g. (2011) an exclusively hyena-collected bone assemblage in the late pleistocene of sicily: taphonomy and stratigraphic context of the large mammal remains from san teodoro cave (northeastern sicily, italy). journal of archaeological science, 38, 12, 3584-3595. doi: 10.1016/j.jas.2011.08.029 marciszak a., gornig w., kropczyk a., rössner g.e. (2022) the latest european record of chasmaporthetes lunensis lunensis (del campana, 1914) from schernfeld (bavaria, germany) in terms of the changes in the european carnivore paleoguilds. stratigraphy & timescales, 7, 137156. doi: 10.1016/bs.sats.2022.09.003 martin r.a. (2012) victoriamys, a new generic name for chaline's vole from the pleistocene of western europe. geobios, 45, 445-450. doi: 10.1016/j.geobios.2012.01.001 martínez l.m., estebaranz-sánchez f., ferràndezcañadell c., romero a., ribot f., galbany j., gibert l., pérez-pérez a. (2020) buccal dentalmicrowear and feeding ecology of early pleistocene theropithecus oswaldi from cueva victoria (spain). journal of human evolution, 142, 102736. doi: 10.1016/j.jhevol.2019.102736 martínez-navarro, b. (2010) early pleistocene faunas and hominin dispersals. in: out of africa i: the first colonization of eurasia (eds. fleagle j.g., shea j.j., grine f.e., baden a.l., leakey r.e.), vertebrate paleobiology and paleoanthropology. springer netherlands, dordrecht, 207-224. doi: 10.1007/978-90-481-9036-2_13 mecozzi b., bellucci l., giustini f., iannucci a., iurino d.a., mazzini i., strani f., sardella r. (2021) a reappraisal of the pleistocene mammal assemblages from the karst infilling deposits of the maglie area (lecce, apulia). rivista italiana di paleontologia e stratigrafia, 127, 355-382. doi: 10.13130/2039-4942/15776 mecozzi b., iannucci a., bona f., mazzini i., pieruccini p., sardella r. (2022) rediscovering lutra lutra from grotta romanelli (southern italy) in the framework of the puzzling evolutionary history of eurasian otter. palz, 96, 1, 161-174. late miocene hyaenictitherium namaquensis (carnivora, hyaenidae) from as sahabi (north africa, libya). historical biology, 34, 8, 1373-1380. doi: 10.1080/08912963.2021.2007529 kargopoulos n., kampouridis p., hartung j., böhme m. (2023a) hyaenid remains from the late miocene of kutschwan (shanxi province, china). palz, 97, 3, 653-666. doi: 10.1007/s12542-023-00658-6 kargopoulos n., roussiakis s., kampouridis p., koufos g.d. (2023b) interspecific competition in ictitheres (carnivora: hyaenidae) from the late miocene of eurasia. comptes rendus palevol, 22(3), 33-44. doi: 10.5852/cr-palevol2023v22a kasparek m., kasparek a., gözcelioğlu b., çolak e., yiğit n. (2004) on the status and distribution of the striped hyaena, hyaena hyaena, in turkey. zoology in the middle east, 33, 1, 93-108. doi: 10.3906/zoo-2007-8 kaup j.j. (1828) ueber hyaena, uromastix, basiliscus, corythaeolus, acontias. isis, 21, 1144-1150. konidaris g.e., kostopoulos d.s. (2024) the late pliocene-middle pleistocene large mammal faunal units of greece. quaternary, 7, 2, 27. doi: 10.3390/quat7020027 konidaris g.e. (2022) guilds of large carnivorans during the pleistocene of europe: a community structure analysis based on foraging strategies. lethaia, 55, 2, 1-18. doi: 10.18261/let.55.2.5 koufos g.d. (2021) the late miocene middle-sized ictitheres (mammalia: hyaenidae) of greece. bollettino della società paleontologica italiana, 60, 1, 19-48. doi: 10.4435/bspi.2021.03 kretzoi m. (1938) die raubtiere von gombaszög nebst einer übersicht der gesamtfauna. annales historico-naturales musei nationalis hungarici, 31, 88157. kruuk h., sands w.a. (1972). the aardwolf (proteles cristatus sparrman) 1783 as predator of termites. african journal of ecology, 10, 3, 211-227. doi: 10.1111/j.1365-2028.1972.tb00728.x kuhn b.f., wiesel i., skinner j.d. (2008) diet of brown hyaenas (parahyaena brunnea) on the namibian coast. transactions of the royal society of south africa, 63, 2, 150-159. doi: 10.1080/00359190809519219 kuhn b.f., berger l.r., skinner j.d. (2010) examining criteria for identifying and differentiating fossil faunal assemblages accumulated by hyenas and hominins using extant hyenid accumulations. international journal of osteoarchaeology, 20, 1, 1535. doi: 10.1002/oa.996 kurtén b. (1956) the status and affinities of hyaena sinensis owen and hyaena ultima matsumoto. american museum novitates, 1764, 1-48. kurtén b., werdelin l. (1988) a review of the genus chasmaporthetes hay, 1921 (carnivora, hyaenidae). journal of vertebrate paleontology, 8, 46-66. doi: 10.1080/02724634.1988.10011683 122 garcía-nos e. et al. morell m.a. (2015) historia de la minería de cueva victoria. in: geología y paleontología de cueva victoria (eds. gibert l., ferràndez-cañadell c.), mastia. revista del museo arqueológico municipal de cartagena “enrique escudero de castro”, 1113, ayuntamiento de cartagena, cartagena, 4758. pieruccini p., forti l., mecozzi b., iannucci a., yu t.l., shen c.c., bona f., lembo g., muttillo b., sardella r., mazzini i. (2022) stratigraphic reassessment of grotta romanelli sheds light on middle-late pleistocene palaeoenvironments and human settling in the mediterranean. scientific reports 12, 1, 13530. doi: 10.1038/s41598-022-16906-9 pons-moyà, j. (1985) nota preliminar sobre el hallazgo de homo sp. en los rellenos cársticos de cueva victoria, murcia españa, endins, 11-12, 4750. qiu z. (1987) die hyaeniden aus dem ruscinium und villafranchium chinas. münchner geowissenschaftliche abhandlungen reihe a: geologie und paläontologie, 9, 1-108. qiu, z., deng, t., wang, b. (2004) early pleistocene mammalian fauna from longdan, dongxiang, gansu, chian. palaeontologica sinica, n. ser. c, 27, 1-198. rajmil j., velazco p.m., giannini n.p. (2023) growing apart: comparative cranial ontogeny in the myrmecophagous aardwolf (proteles cristata) and the bone-cracking spotted hyaena (crocuta crocuta). journal of mammalian evolution, 30, 2, 363-370. doi: 10.1007/s10914-023-09653-9 ribot trafí f., ferràndez-cañadell c., gibert beotas l. (2015) los primates de cueva victoria. in: geología y paleontología de cueva victoria (eds. gibert l., ferràndez-cañadell c.), mastia. revista del museo arqueológico municipal de cartagena “enrique escudero de castro”, 11-13, ayuntamiento de cartagena, cartagena, 433-452. rook l., martínez-navarro b., howell f.c. (2004) occurrence of theropithecus sp. in the late villafranchian of southern italy and implication for early pleistocene “out of africa” dispersals. journal of human evolution, 47, 267-277. doi: 10.1016/j.jhevol.2004.08.001 rook l., martínez-navarro b. (2013) the large sized cercopithecoid from pirro nord and the importance of theropithecus in the early pleistocene of europe: faunal marker for hominins dispersal outside africa. palaeontographica abteilung, a, paläozoologie stratigraphie, 298, 107-112. doi: 10.1127/pala/298/2013/107 sánchez marco a. (2015) aves del pleistoceno inferior de cueva victoria (costa sudoriental mediterránea de la península ibérica). in: geología y paleontología de cueva victoria (eds. gibert l., ferràndez-cañadell c.), mastia. revista del museo arqueológico municipal de cartagena “enrique escudero de castro”, 11-13, ayuntamiento de cartagena, cartagena, 253-268. sardella r., petrucci m. (2012) the earliest middle pleistocene crocuta crocuta (erxleben, 1777) at doi: 10.1007/s12542-021-00553-y mecozzi b., bona f., conti j., lembo g., mariani g.s., mazzini i., muttillo b., pieruccini p., sardella r. (2024) large mammal faunas and ecosystem dynamics during the late middle to early late pleistocene at grotta romanelli (southern italy). quaternary science advances, 16, 100237. doi: 10.1016/j.qsa.2024.100237 michel v., shen c.-c., woodhead j., hu h.-m., wu c.c., moullé p.-e., khatib s., cauche d., moncel m.h., valensi p., chou y.-m., gallet s., echassoux a., orange f., de lumley h. (2017) new dating evidence of the early presence of hominins in southern europe. scientific reports, 7, 10074. doi: 10.1038/s41598-017-10178-4 mills m.g.l. (1982) factors affecting group size and territory size of the brown hyaena, hyaena brunnea, in the southern kalahari. journal of zoology london 198, 39-51. doi: 10.1111/j.1469-7998.1982.tb02059.x mills m.g.l. (1990) kalahari hyenas: the comparative behavioral ecology of two species. chapman & hall, london. morales-pérez j.v., ripoll m.p., pardo j.j., álvarezfernández e., gonzález a.m., tortosa j.a. (2019) mediterranean monk seal hunting in the regional epipalaeolithic of southern iberia. a study of the nerja cave site (málaga, spain). quaternary international, 515, 80-91. doi: 10.1016/j.quaint.2017.11.050 morlo m., engel t., bastl k., lischewsky b., lutz h., von berg a., nagel d. (2019) hyaenidae (carnivora, mammalia) from the late miocene (mn 9/10) dinotheriensande. mainzer naturwissenschaftliches archiv, 56, 15-28. palombo m.r., sardella r., novelli m. (2008) carnivora dispersal in western mediterranean during the last 2.6 ma. quaternary international, 179, 176 -189. doi: 10.1016/j.quaint.2007.08.029 patel b.a., gilbert c.c., ericson k.e. (2007) cercopithecoid cervical vertebral morphology and implications for the presence of theropithecus in early pleistocene europe. journal of human evolution, 52, 113-129. doi: 10.1016/j.jhevol.2006.07.014 pérez-claros j.a. (2024) unravelling the origin of the brown hyena (parahyaena brunnea) and its evolutionary and paleoecological implications for the pachycrocuta lineage. palaeontologia electronica, 27(1), 27.1.a18. doi: 10.26879/1372 pérez-claros j.a., coca-ortega c. (2020) canines and carnassials as indicators of sociality in durophagous hyaenids: analyzing the past to understand the present. peerj, 8, e10541. doi: 10.7717/peerj.10541 pérez-claros j.a., coca-ortega c., werdelin l. (2021) how many hyenas in north america? a quantitative perspective, journal of vertebrate paleontology, 41, 3, e1979988. doi: 10.1080/02724634.2021.1979988 pérez de perceval m.a., manteca martínez j.i., lópez 123 cueva victoria and hyena-seal records in pleistocene europe thunberg c.p. (1820) beskrifning och teckning på etr nytt species, hyaena brunnea. kungliga svenska vetenskapsakademiens handlingar för år, 1, 5965. tseng z.j., antón m., salesa m.j. (2011) the evolution of the bone-cracking model in carnivorans: cranial functional morphology of the pliopleistocene cursorial hyaenid chasmaporthetes lunensis (mammalia: carnivora). paleobiology, 37, 140-156. doi: 10.1666/09045.1 tseng z.j., li q., wang x. (2013) a new cursorial hyena from tibet, and analysis of biostratigraphy, paleozoogeography, and dental morphology of chasmaporthetes (mammalia, carnivora). journal of vertebrate paleontology, 33, 6, 1457-1471. doi: 10.1080/02724634.2013.775142 turner a. (2009) the evolution of the guild of large carnivora of the british isles during the middle and late pleistocene. journal of quaternary science, 24, 8, 991-1005. doi: 10.1002/jqs.1278 turner a., antón m. (1996) the giant hyaena pachycrocuta brevirostris (mammalia, carnivora, hyaenidae). geobios, 29, 455-468. doi: 10.1016/s0016-6995(96)80005-2 turner a., antón m., werdelin l. (2008) taxonomy and evolutionary patterns in the fossil hyaenidae of europe. geobios, 41, 677-687. doi: 10.1016/j.geobios.2008.01.001 valenzuela-toro a., pyenson n.d. (2019) what do we know about the fossil record of pinnipeds? a historiographical investigation. royal society open science, 6, 11, 191394. doi: 10.1098/rsos.191394 van der made j. (2015) the latest early pleistocene giant deer megaloceros novocarthaginiensis n. sp. and the fallow deer dama cf. vallonnetensis from cueva victoria (murcia, spain). in: geología y paleontología de cueva victoria (eds. gibert l., ferràndez-cañadell c.), mastia. revista del museo arqueológico municipal de cartagena “enrique escudero de castro”, 11-13, ayuntamiento de cartagena, cartagena, 269-324. vilà-vinyet j., soriguera-gellida i., ferràndez-cañadell c. (2015) génesis de una acumulación osífera excepcional en cueva victoria (cartagena, murcia, españa). in: geología y paleontología de cueva victoria (eds. gibert l., ferràndezcañadell c.), mastia. revista del museo arqueológico municipal de cartagena “enrique escudero de castro”, 11-13, ayuntamiento de cartagena, cartagena, 163-174. werdelin l., solounias n. (1991) the hyaenidae: taxonomy, systematics and evolution. fossils and strata, 30, 1-104. doi: 10.18261/8200374815-1991-0 werdelin l., solounias n. (1996) the evolutionary history of hyaenas in the miocene of europe and western asia. in: the evolution of western eurasian neogene mammal faunas (eds. bernor r.l., fahlbusch v., mittmann h.-w.), columbia university press, new york, 290-306. casal selce (rome, italy). quaternary international, 267, 103-110. doi: 10.1016/j.quaint.2012.01.028 sardella r., mazzini i., giustini f., mecozzi b., brilli m., iurino d.a., lembo g., muttillo b., massussi m., sigari d., tucci s., voltaggio m. (2018) grotta romanelli (southern italy, apulia): legacies and issues in excavating a key site for the pleistocene of the mediterranean. rivista italiana di paleontologia e stratigrafia, 124, 2, 247-264. doi: 10.13130/2039-4942/9983 sardella r., iurino d.a., mecozzi b., sigari d., bona f., bellucci l., coltorti m., conti j., lembo g., muttillo b., mazzini i. (2019) grotta romanelli (lecce, southern italy) between past and future: new studies and perspectives for an archaeo-geosite symbol of the palaeolithic in europe. geoheritage, 11, 1413-1432. doi: 10.1007/s12371-019-00376-z scheel d.m., slater g.j., kolokotronis s.o., potter c.w., rotstein d.s., tsangaras k., greenwood a.d., helgen k.m. (2014) biogeography and taxonomy of extinct and endangered monk seals illuminated by ancient dna and skull morphology. zookeys, 409, 1-33. doi: 10.3897/zookeys.409.6244 schütt g. (1971) die hyänen der mosbacher sande (altpleistozän, wiesbaden/hessen) mit einem beitrag zur stammesgeschichte der gattung crocuta. mainzer naturwissenschaftliches archiv, 10, 2976. semenov y. (2008) taxonomical reappraisal of “ictitheres” (mammalia, carnivora) from the late miocene of kenya. comptes rendus palevol, 7, 8, 529-539. doi: 10.1016/j.crpv.2008.09.012 skinner j.d., van aarde r.j., goss r.a. (1995) space and resource use by brown hyenas hyaena brunnea in the namib desert. journal of zoology, 237, 1, 123-131. doi: 10.1111/j.1469-7998.1995.tb02751.x spassov n. (2024) the final pliocene and early pleistocene faunal dispersals from east to europe and correlation of the villafranchian biochronology between eastern and western europe. quaternary, 7, 4, 43. doi: 10.3390/quat7040043 strani f. (2021) impact of early and middle pleistocene major climatic events on the palaeoecology of southern european ungulates. historical biology, 33, 10, 2260-2275. doi: 10.1080/08912963.2020.1782898 strani f., demiguel d., alba d.m., moyà-solà s., bellucci l., sardella r., madurell-malapeira j. (2019) the effects of the “0.9 ma event” on the mediterranean ecosystems during the early-middle pleistocene transition as revealed by dental wear patterns of fossil ungulates. quaternary science reviews, 210, 80-89. doi: 10.1016/j.quascirev.2019.02.027 tavani g. (1941) revisione dei resti del pinnipede conservato nel museo di geologia di pisa. palaeontographia italica, 40, 97-113. 124 garcía-nos e. et al. wilkinson c.e., dheer a., zett t., torrents-ticó m., yarnell r.w., bar ziv e., bhandari s., jacobson a., dloniak s.m. (2024) review of the global research on hyaenidae and implications for conservation and management. mammal review, 54, 2, 193-212. doi: 10.1111/mam.12337 westbury m.v., le duc d., duchêne d.a., krishnan a., prost s., rutschmann s., grau j.h., dalén l., weyrich a., norén k., werdelin l., dalerum f., schoneberg t., hofreiter m. (2021) ecological specialization and evolutionary reticulation in extant hyaenidae. molecular biology and evolution, 38(9), 3884-3897. doi: 10.1093/molbev/msab055 wiesel i. (2006) predatory and foraging behaviour of brown hyenas (parahyaena brunnea (thunberg, 1820)) at cape fur seal (arctocephalus pusillus pusillus schreber, 1776) colonies. unpublished phd thesis. university of hamburg, germany. 125 cueva victoria and hyena-seal records in pleistocene europe ms. received: november 19, 2024 revised: december 13, 2024 accepted: december 14, 2024 available online: december 18, 2024 ojs 733 peresani 185-204.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 36 (2), 2023, 185-204 1. introduction because of its strategic position between africa and continental europe, italy with its variegated landscape is particularly suitable for palaeoecological, archaeological and palaeoanthropological studies. during the pleistocene, distinct human migration waves occurred in western eurasia, particularly in its southern area, leaving ephemeral and progressively more and more consistent traces framed in their ecological context. continental italy and, above all, peninsular italy preserve abundant biological and cultural fossil record, placed in peculiar geographical and ecological contexts that stimulate the investigation of population dynamics, adaptations, and cultural transition across the whole pleistocene. in the last two decades there have been a number of new discoveries of sites, cultural items and human remains from across the country spanning from the lower to the upper palaeolithic. in the meantime, many materials, specimens, chronologies have been reconsidered and re-evaluated to increase our knowledge of crucial findings attributed to homo heidelbergensis, homo neanderthalensis and homo sapiens populations in the widest western eurasian scenario. italy is mostly a mountainous and coastal country. the alpine chain, mainly e-w oriented, reaching elevations >4500 m in its western range, alongside with the apennines, nw-se oriented, with elevations >2500 m, acted as important ecological barriers, respectively towards continental europe and splitting the peninsula in two sides. the western one is influenced by the mediterranean climate, while the eastern side is more subjected adaptations and cultures of pleistocene humans in italy marco peresani dipartimento di studi umanistici, sezione di scienze preistoriche e antropologiche, univ. degli studi di ferrara, ferrara, italy. istituto di geologia ambientale e geoingegneria, consiglio nazionale delle ricerche, milano, italy. corresponding author: marco peresani <psm@unife.it> abstract: italy preserves abundant biological and cultural fossil record, placed in peculiar geographical and ecological contexts that stimulate the study of population dynamics, adaptations, and cultural transitions during the whole pleistocene. such a variegated territory, bounded by the alpine chain and longitudinally split by the apennines, hosted distinct migration waves attributed to unidentified hominins, and to homo heidelbergensis, homo neanderthalensis, homo sapiens in a heterogeneous scenario subjected to profound changes during extreme sea-level lowering. the first human colonization occurred around the early to middle pleistocene transition, presumably driven by major faunal renewals which invested southern europe. these first proofs are documented in the oldest sites, pirro nord and monte poggiolo, with lithic industries based on core-and-flake technology. after a gap in the evidence of human settlements between mis19 and mis17, the earliest acheulean makes its appearance in southern italy starting from 661-614 ka. large cutting tools typical of this complex remain however poorly represented throughout the early middle pleistocene, in favour of the tiny and medium-sized flakes which feature the lithic industries until the conventional end of the lower palaeolithic. specifically, these small tools mark the middle pleistocene interaction between hominins and elephants, as documented in many sites in central italy. as regards the middle palaeolithic, its archaeological and anthropological record looks more consistent and proves that neanderthals inhabited southern europe and continental italy. the neanderthal record refers to settlement patterns and mobility strategies in the geographic and environmental districts that feature most of the regions at the alpine fringe, along the apennine chain and the rocky coasts. settlements have complementarity character, with long-term occupations and other locations used for short time, particularly caves and sheltered sites, where the stratigraphic sequences record multioccupations covering large time intervals and repeated environmental changes. as a matter of fact, some environmental changes are related to cultural turnovers like the appearance of the mousterian quina during mis4 in the north of italy. hunting and dietary behaviour reconstructed from a number of sites stimulates debate around possible convergencies or divergencies between neanderthals and the first homo sapiens communities who started settling italy since about 44-43 cal ka bp. pieces of the neanderthal -sapiens biocultural transition with contested attributions have been unveiled in recent years at key archaeological sites, either in the north and in the south of italy, producing an incontestable contribution for reconstructing these dynamics in europe. this is specifically the case of the uluzzian with its cultural package of lithic and bone technologies and ornamental beads, that follows in time the oldest known cultural expressions of homo sapiens in other regions of western eurasia. the spread of early sapiens is also related to the aurignacian and marks another intriguing cultural dynamic of the upper palaeolithic, prolongating across the last glacial maximum and the late glacial, two turning points for the bio-geographical, anthropological and cultural evolution marked by the loss of large continental plains and the rearrangement of all ecozones of human populations. as consequence of the late glacial interstadial warming, a large-scale epigravettian colonization of the mountain ranges started and continued in the mesolithic until the disappearance of those hunter-gatherer populations. keywords: settlement, human adaptation, migration, culture, palaeolithic. https://doi.org/10.26382/amq.2023.08 to continental conditions. extensive and long-lasting tectonic activity, together with the major geomorphic processes attributable to glacial, fluvial and marine erosion, fluvial sedimentary aggradation, and volcanic activity contributed to produce a heterogeneous physiography, with considerable extension of the coasts during the extreme sea-level lowering. furthermore, given its latitudinal extension from 38° to 47° n, italy is featured by a strong climatic gradient, in turn favouring a marked biodiversity also enhanced by the extensive variety of bedrocks. the pattern of modern precipitation values ranges from >2000 mm/year in the prealpine belt of northern italy to <500 mm/year in some areas especially of southern italy and sicily. during the pleistocene global climatic turnovers, these values, alongside the average t° dramatically varied and impacted on the extention of the icesheets, landmass, biomass and ecological variability with maintenance of remarkable differences across the peninsula and especially between the western and eastern sides. 2. the oldest lower palaeolithic settlements and the transition from the early to middle pleistocene when, where and in which conditions the first colonization of western mediterranean europe by hominins occurred is one of the most debated topics in palaeoanthropology and prehistoric archaeology. researchers agree on human’s dispersal events towards w europe during the late early pleistocene, probably occurred earlier than 1.2 ma, as demonstrated by chronometrically dated finds in spain (huguet et al., 2017). furthermore, models elucidate that this dispersal was likely part of the progressive faunal renewal, which also involved some large mammals of african origin during the early pleistocene (manzi et al., 2011). such a first distinct wave of humans is documented at orce and atapuerca sima del elefante and has been referred to homo antecessor, which remains were found associated with stone artefacts attributed to the so-called mode 1. these industries are largely known in many sites of the mediterranean and continental regions. large discontinuities affect the archaeological record up to the early middle pleistocene for a range of taphonomic, visibility and research reasons, with no exclusion of ecological conditions. human dispersal into europe is thus attributable to morphologically derived hominins, well known from atapuerca (bermúdez de castro et al., 2011) and to several sites where bone remains broadly included within the homo sp. were found. this significant human presence has been related to the major faunal renewal that characterised the early to middle pleistocene transition. this hypothesis is supported by evidence of a major episode in the reorganization of mammalian fauna since at least 1.3 ma, with dispersals of taxa most of which persisted throughout the middle pleistocene and respective reconstruction of mammalian faunal complexes (palombo, 2010). as expressed above, the italian peninsula is an important benchmark for reconstructing the chronological and cultural data about the diffusion of genus homo outside africa. archaeological sites (fig. 1) testify to an early occupation of italy and corroborate models about the exit from africa that could have spread from the middle east. the oldest archaeological evidence comes from pirro nord in apulia, s italy, dated on biochronological base to 1.6-1.3 ma. the site counts a large assemblage of fossil vertebrates (pirro nord faunal unit) and short reduction sequences deeply adapted to obtain flakes (arzarello et al., 2012). however, this chronological interval has been criticized by muttoni et al. (2018) because of the lack of magneto-stratigraphical and numerical dates. thus, an age of >0.78 ma has been proposed for pirro nord, instead, according to the biochronology of the mammal association, the correlation between bones and cut-marked bones, stone tools and the sedimentary infill of the karts structure. if the old chronology is confirmed, a long gap separates pirro nord from the open-air site of cà belvedere di monte poggiolo in the n apennine, dated to about 0.9 ma by esr and palaeomagnetism (muttoni et al., 2011). the site is characterized by core-on-flake technology and abundant refitting which allowed the reconstruction of complete reduction sequences (peretto et al., 1998). thanks to refits, is has been possible to understand than local raw materials only allowed the production of short reduction sequences (ssda or centripetal) to obtain flakes which were rarely shaped through retouched edges. this first phase of occupation fits perfectly with the other european sites dated between 1.3 and 0.9 ma. however, the oldest italian sites do not present retouched lithic elements in their assemblages, although at pirro nord it might be observed a strong predetermination (chelli cheheb et al., 2019). 3. the middle pleistocene, the acheulean and other complexes ultimately, there are no archaeological sites between marine isotope stage (mis) 19 and mis 17 and the sites recorded in an indisputable stratigraphic context between mis 17 and mis 12 are few and fragmented both temporally and spatially (fig. 1). however, the timing and occurrence of the settlement in this timespan and the related technical behaviours are subjected to different interpretations (muttillo et al., 2021). the middle pleistocene human fossil record is represented by the partial femur shaft from venosa notarchirico (moncel et al., 2020), and the human deciduous incisor from isernia la pineta (peretto et al., 2015). it is worth to mention ceprano in southern latium for human remains, as a calvarium in primary deposits was recovered and dated to 400 ka. it has no apomorphic neanderthal trait, while shows similarities with specimens attributed to homo heidelbergensis in e africa (manzi et al., 2001). it supports the phylogenetic significance of ceprano as the best candidate to represent the ancestral morphology of this putative polymorphic species (manzi, 2016). nearby this site, the human teeth rcovred at fontana ranuccio (k/ar dated to 0.46, muttoni et al., 2009) shows morphological traits supporting an evolutionary continuity between the mid pleistocene humanity and neanderthals (rubini et al., 2014; zanolli et al., 2018). this affinity, alongside with the apparent contrast with ceprano, hints at more archaic morpholo 186 peresani m. (moncel et al., 2020). during this phase, large cutting tools are poorly or not represented in the italian peninsula. the lithic assemblage of isernia la pineta (583561 ka) reflects this situation. it is mainly composed of small and medium-sized flakes of local flint and limestone but no bifaces (peretto et al., 2015). these sites share similar riverine contexts despite the differences observed in the archaeological assemblages (muttillo et al., 2021). one of the most intriguing pieces of evidence of middle pleistocene hominin behaviour in italy is related to the interaction between hominins and elephants, as gies retained by 400 ka populations in italy, contrary to other populations in southern and central europe (manzi, 2016). these, instead, already showed varying grades of morphological progression towards the typical neanderthal assemblage of traits, thus suggesting the occurrence of different sub-species of homo heidelbergensis in the same timeframe. profound changes between the first appearance of human groups in southern europe and the early use of hand axes occurred at the end of the middle pleistocene climatic revolution. notarchirico is the earliest acheulean assemblages in italy, and it is dated to 661-614 ka 187 adaptations and cultures of pleistocene humans in italy fig. 1 most relevant lower palaeolithic sites in italy: 1) visogliano; 2) quinzano; 3) monte poggiolo; 4) ficoncella; 5) castel di guido; 6) torre in pietra; 7) polledrara di ceccanibbio; 8) fontana ranuccio; 9) valle giumentina; 10) pirro nord; 11) isernia la pineta; 12) guado san nicola; 13) roccamonfina; 14) notarchirico; 15) atella (source http://tinitaly.pi.ingv.it; elab. by d.delpiano). testified from elephant bones with presence of anthropogenic surface modifications. such evidence can be found to archaeological and taphonomic records in africa, europe, and asia where remains of palaeoloxodon antiquus and lithic tools coexist (agam & barkai, 2018; panagopoulou et al., 2018 and references therein). medium sized lithic tools with residues and use-wear related to animal tissues processing, found in association with carcasses and articulated bones, corroborate the involvement of these animals in the diet of lower palaeolithic hominins (aranguren et al., 2019). elephants were not exclusively exploited for meat, fat, and marrow: their bones were also used as raw material to produce flakes and various types of large bone tools among such as handaxes (barkai, 2021; villa et al., 2021). given the paramount importance of these animals as sources of food and raw material it might be assumed that also affected hominins’ behaviour and their landscape exploitation strategies (lemorini et al., 2022). under this light, a remarkable site of reference is la polledrara di cecanibbio where elephant carcass and lithic implements were found in fluvial and fluvio-palustrine fossiliferous deposits included in the ponte galeria sequence 6 of the aurelia formation (mis10 and mis9; santucci et al., 2016). the optimal quantity and degree of preservation of the faunal remains thanks to the contemporaneous re -sedimentation of a volcanic unit dated 325–310 ka (pereira et al., 2017), allowed to unearth large mammals like palaeoloxodon antiquus and bos primigenius, together with lithic and bone artifacts but no bifaces. the interpretation of butchering activities going on the site is consequence of the over 500 stone flakes recovered around the carcass of a single elephant in anatomical connection. data obtained from a recent study and compared to previous published papers (cerilli & fiore, 2018) shed light on a sequence of events occurring over a long-time span from a fresh carcass to a completely bare skeleton. the human interaction with the body of the elephant, entrapped in the mud, consisted in a series of butchering sessions occurring in a few days (lemorini et al., 2022). these interactions probably followed of the organization of a hunting session. another hypothesis is that the elephant carcass, probably partly scavenged by other predators, was found during routine exploration and exploitation of the landscape and totally scavenged by hominins adapted with flexible dietary behavior and equipped with a toolkit suitable to these situations. 4. neanderthals and the middle palaeolithic due to the blurred chronology of the middle palaeolithic, especially of its earliest phase, the understanding of the variability and evolutionary patterns of the late acheulean and first mousterian techno-complexes is quite limited. nonetheless, a consistent archaeological record attests that neanderthals inhabited s europe and italy throughout the entire middle palaeolithic (fig. 2). starting from the earliest attestations, one of the most spectacular pieces of evidence is reported at foresta ichnosite in sw italy, also known as ‘devil’s trails’, impressed on top of the ls7 pyroclastic unit dated 345350 ka (mis 10). at this site, a minimum number of three individuals left isolated footprints and trackways moving downslope but also in the opposite direction with respect to the others (panarello et al., 2020; mietto et al., 2022). human fossil specimens have been found all over italy and bear a mixture of archaic features and more progressive (neanderthal) traits, as attested by the skeleton from altamura (s italy) and skulls found at saccopastore. skulls, teeth and appendicular skeleton remains were found at grotta guattari also during recent excavations (rolfo et al., in press). isolated teeth come from several sites from northern to sougìthern italy, like ciota ciara, riparo broion, riparo tagliente, grotta fumane, grotta de nadale and grotta taddeo, grotta cavallo, spinadesco, and campoverde (buzi et al., 2021). the altamura skeleton is one of the most complete human specimens of late middle pleistocene in europe. it was found in the karstic cave of lamalunga in puglia and apparently was not associated to any lithic artifact. it is covered of large calcite concretions, u/th dated between 172±15 and 130.1±1.9 ka (lari et al., 2015). bones support the idea that the individual remained trapped in the karstic system and died right in the place of deposition, as any sign of transportation, modification or deformation was observed. neanderthals’ settlement patterns and mobility strategies varied in the different italian geographic and environmental areas, although adaptations to ecological contexts are still poorly known all across many districts. the settlements are characterised by a complementarity between long-term occupations and locations showing short-time, repeated occupations, particularly in caves and sheltered sites where stratigraphic sequences span wide time intervals and cover an ensemble of environmental changes (romagnoli et al., 2022). the technoeconomic variability might be explained by different mobility strategies, technological traditions and neanderthal behaviour. the result is a complex mosaic between expediency and curation in the organization of production and maintenance of stone tools, with continuities and ruptures across time. currently, this dynamic and kaleidoscopic scenario cannot be interpreted according to a universal model either of time or space (romagnoli et al., 2018; delpiano et al., 2019). italy was well-populated by neanderthals all across the mp and especially at its end, as demonstrated by the density of sites. human presence was recorded in caves and shelters, in the open-air on fluvial terraces, hill tops, karst surfaces, mountain ridges. although neanderthal population density cannot be estimated yet, studies on land-use patterns and mobility reveal that their settlements covered a wide biogeographic range, bounded from the north by the pre-alpine fringe and to the south by the marine coasts. unfortunately, due to alpine glaciers and periglacial processes, the archaeological record preserved only on mountain and hilly sectors on the southern alpine slope spared by these processes. the reconstruction of the settlement system can be inferred by sites located on those fluvial terraces situated at the edge of the mountain range, spared by destructive post-depositional processes. the same holds for the apennine range, which hosts several sites also up to its inner ridge. in the ital 188 peresani m. humans all along the pre-alpine area (margaritora et al., 2020). settling this region was favoured by the geographical variability and dense spacing of biotopes which characterize the belt between the upper alluvial plain and the pre-alpine range. presumably, neanderthal groups developed different models of mobility and exploitation of resources across this territory and used the main caves for complex and intense human occupaian alps, mid-altitude caves like for instance the caverna generosa at 1,450 m of altitude in the lombard pre-alps can be viewed as refugia-locations used in function of constrained factors influenced by altitude and ecoclimatic situations (bona et al., 2007). these mountain sites scattered at 1300-1400 m a.s.l., peaking at 1600 m and bearing traces from ephemeral to consistent, might well be integrated within the seasonal movements of 189 fig. 2 selection of middle palaeolithic sites in italy: 1) grotta del rio secco; 2) grotta maggiore di san bernardino; 3) grotta e riparo del broion; 4) covolo de nadale; 5) grotta di fumane; 6) rìparo tagliente; 7) vajo salsone; 8) monte netto; 9) ciota ciara; 10) balzi rossi; 11) san francesco; 12) arma delle manie; 13) ghiardo; 14) podere due pozzi 15) grotta del capriolo; 16) grotta all'onda; 17) campitello; 18) poggetti vecchi; 19) grotta la fabbrica; 20) grotta di cala dei santi; 21) saccopastore; 22) casal de pazzi; 23) grotta guattari; 24) grotta breuil; 25) grotta del fossellone; 26) grotta dei moscerini; 27) grotta reali; 28) monte conero; 29) grotta paglicci e riparo esterno; 30) grotta delle mura; 31) lamalunga; 32) riparo dell'oscurusciuto; 33) grotta del cavallo; 34) grotta romanelli; 35) grotta di castelcivita; 36) grotta della cala; 37) grotta e riparo del poggio; 38) riparo del molare; 39) archi (source http://tinitaly.pi.ingv.it; elab. by d.delpiano). adaptations and cultures of pleistocene humans in italy tions. this was particularly the case of the venetian and carnic pre-alps, where differences in anthropogenic features, spatial patterning, stone knapping methods and bone industries likely reflect different adaptive responses at ecological factors. however, due to the bias in the preservation of the archaeological record, not all the finds share the same informative potentiality. for instance, open-air sites, strongly affected by post-depositional disturbance which caused the impoverishment of past human activity traces with substantial loss of information. at any rate, some information can be acquired also by their location features furnishing details about territoriality and site catchment. as a consequence, aspects of the settlement system inferred from site exploitation territory, site function and raw material circulation are accessible only in a limited range of evidence, the more detailed of which are often provided by the stratified archives (i.e., delpiano et al., 2019). thanks to the layout of these contexts human behavior can be explored in relation to the environmental context: current data on systems in coastal, hill and mountain landscapes can enrich our knowledge on the seasonal nomadism practiced by neanderthals. caves presumably had a main role thanks to their strategic position, being favourable for catchment in different environments through short-range movements. the variety of hunted animal species confirms opportunities to diversify the exploitation of animal resources. if we add the possibility for the human groups to easily access the primary exposures and secondary deposits of chert, we can argue that neanderthal huntergatherers’ ecological adaptations were deeply influenced from the not homogenous distribution of resources, so typical of the italian landscape. this plethora of evidence allowed the reconstruction of neanderthal hunting behaviour. hunting was shaped by game availability in the surroundings, particularly at hilly and mountain landscape lowlands junction rather than specialization or selection of selected taxa, as confirmed by zooarchaeological data. not surprisingly, caves in the pre-alpine and sub-alpine area, located in proximity of a range of ecological contexts, reveal that ungulates were hunted conformably to the respective specific ecological conditions at each site (romandini et al., 2020; terlato et al. 2021). the location and the ecological context of caves placed at low-mid altitude in landscapes dissected by deep valleys with cliffs and steep slopes in proximity to the alluvial plain and the mountain grassland belt, favoured the exploitation of different prey, despite the efforts required to cover the distance from and to the site. although for some context we only have preliminary data, it seems that these sites were used as place where to finalize the processing of carcasses after having begun at the kill site and especially for red-deer and roe-deer. as a matter of fact, as indicated by the pattern of preservation of skeletal elements, selected anatomical parts with high nutritional value, such as limbs, especially hind, and to a lesser extent the cranium, were brought to the site. thus, it can be envisaged well-established and cost-effectiveness patterns in the selection of specific skeletal portions, as a function of factors like the weight of the red-deer and roe-deer carcass portions and the distance between the kill site and the home base (romandini et al., 2014a; terlato et al., 2021). on the other hand, some sites at the edge of the murge karst plateau in southern italy showed hunting adaptation behaviours, where skeletal parts from bos and other ungulates were selected in relation to the exploitation of long bones for the extraction of marrow and the probable use of epiphysis and articular bones as fuel (boscato et al., 2011). further signatures of uncommon hunting and dietary behaviour produced at fumane stimulate debate around possible convergencies or divergencies between neanderthal groups and also with modern human communities. as a matter of fact, the hunting of bears and cave bears by neanderthals marks a particular signature, together with the ones of carnivores and rodents exploited for fur, like fox, which are animals commonly targeted during the upper palaeolithic (romandini et al., 2018a; 2018b). during different periods and mousterian cultures, it can be inferred also the role that birds played in the complexity of neanderthal subsistence, especially when evidence of avifaunal resource exploitation was found at different sites, as shown at fumane (peresani et al., 2011; fiore et al., 2016). birds were likely not an elusive resource, possibly favoured by the ecological conditions and the presence of cliffs in proximity of the sites and their contribution in the dietary balance is far from the amount of protein provided by herbivore prey. these conditions stimulate future investigations to deep our knowledge about the acquisition of birds, the butchering process and the successive consumption. one further point of interest is marked by the variability of technocomplexes all across the late middle palaeolithic, as shown by certain key sites like grotta de nadale, fumane, riparo tagliente, grotta rio secco, grotta madonna dell’arma, grotta guattari, grotta castelcivita, riparo paglicci, riparo oscurusciuto and others. it stimulates debating about neanderthals’ cultural variability, ecology and economy of subsistence related to different methods of chert knapping and the design of a range of lithic tool types. these variables are under the focus of ongoing research when advanced evidence might be achieved following the same approach and protocol of investigation for identifying similarities or divergencies in the exploitation patterns of specific prey. particularly in cases where the zooarchaeological record produces signatures of standardized actions on both soft and hard tissues, systematic practices in the sequence of faunal processing have been assessed. further evaluation whether each range of game available at the site surroundings was exploited following standardized processes but by different cultural groups using distinct lithic technologies and related stone tools, is an intriguing issue (romandini et al., 2020). it is undeniable that this requires in-depth inspections across mousterian sequences, where levallois alternates with discoid, which were the most common technologies used by neanderthals in italy. levallois was the dominant knapping method at most of mp sites, despite of their function, geomorphological and ecological context, raw materials and hunting behaviours of their inhabitants (palma di cesnola, 1996; marciani et al., 2020). currently, early mp technology including levallois and prepared-core technolo 190 peresani m. blanks (peresani et al., 2015) but it was related to both expedient and curated behaviours in different moments across the stratigraphic sequences, probably due to changes in mobility strategies and toolkit provisioning in accordance with site function and the duration of occupation. although its documentation in the archaeological record is still partial, this behaviour might also be correlated to the use of a site as a storage location over time (peresani et al., 2015). amongst the sites showing adaptation to the distribution of resources, it is worth mentioning the pontinian mousterian in coastal latium. this ensemble of industries was based on the exploitation of small pebbles chipped also by bipolar percussion on anvil and further reduced by free-hand percussion or retouched to obtain cortical tools (kuhn, 1990). although dates are uncertain, the pontinian should have been a local technological tradition from mis 5-3. a further example of specific neanderthal adaptation to local resources is attested by the exploitation of callista chione’s marine shells to shape retouched tools (douka & spinapolice, 2012). this behaviour is recognized in several sites along the tyrrhenian and ionian coasts, although their chronological framework is still uncertain (romagnoli et al., 2016). in continuity with the abovementioned dynamic material culture of neanderthals, fumane cave has provided clues on the evolution of human behaviour refusing the view that neanderthals did not make use of symbolic items. rather, they gave attention to the aesthetic or uniqueness of certain materials of biological nature. although direct and indirect evidence are still scanty if compared to the upper palaeolithic, the middle palaeolithic groups a varied ensemble of materials also of inorganic nature like raptor claws, remix feathers, ochre, marine shells, green colour pebbles (peresani et al., 2011; 2021, romandini et al., 2014b). 5. transition from the middle to the upper palaeolithic the pivotal phase of human evolution represented by the middle to upper palaeolithic transition in western eurasia had a definitive impact on humankind. when and how the native population of homo neanderthalensis lived and was definitely replaced by homo sapiens is a subject of heat debate and it is far from being clarified yet. studies focused on the relations between them and their respective ecological conditions and material cultures were carried on based on ecological, behavioural and cognitive spheres of these humans. recently, a multidisciplinary research conducted at key archaeological sites in italy produced an incontestable contribution for reconstructing the bio-cultural dynamics southern europe jigsaws of such an intriguing puzzle with contested attributions of some specific expressions of past human diversity. amongst many archaeological and anthropological records, grotta fumane, riparo broion, riparo bombrini, grotta cavallo, grotta castelcivita, grotta roccia san sebastiano and others contain the most important record and are successfully producing evidence of direct implication for the history of humankind in this strategic area of the mediterranean rim (fig. 3). the last achievements in the reconstruction gy, branching and a large variety of retouched items, is attested since mis 9-8 at cave dall’olio in emiliaromagna (fontana et al., 2013), and in latium (villa et al., 2016). however, in multi-layered sites is attested the alternation or co-presence with other lithic exploitation strategies following the discoid method (e.g., fumane and rio secco, bombrini and riparo mochi and grotta principe, grotta cavallo and riparo bernardini). laminar production is also known in the italian mp. blades were produced both within levallois modalities and as unipolar volumetric debitage (marciani et al., 2020). bladelets are sporadically attested, and the assemblages are never characterised by a sole production method. furthermore, in the assemblages, expeditive productions are usually associated with more formal technologies. as a matter of fact, it seems plausible that the production with discoid knapping methods by certain groups of neanderthals supported them to adopt an opportunistic exploitation of cherts (delpiano et al., 2018). neanderthal behavioural variability is also expressed by the mousterian quina techno-complex, as attested by lithic assemblages found at fumane and de nadale, both chronologically framed in a cold phase of the upper pleistocene between 70 and 60 ka, coincident with mis4. the assemblages consist of cores, large flakes with thin transverse edge or short and thick flakes, and scrapers shaped by three or more orders of stepped -scaled (quina-type) retouch. overall, they share similarities with the quina reduction methods and technofunctional lay-outs identified in w europe, providing opportunities to compare evidence at the large scale in the same chronological interval (delpiano et al., 2022). aside the quina tools, sidescrapers in the italian mousterian industries are the most frequent retouched tools, followed by denticulates, notched tools and rare points. the intensity of retouch and resharpening varies from site to site, as the ratio between retouched and unretouched items. the fact that knappable stones and finished tools were introduced to a given site have been related to multiple factors like the duration of human occupation, site function and cultural patterns, including recycling. chert is the mainly exploited material in the middle palaeolithic sites, and it was generally collected locally and regionally (within 30 km of the site). nevertheless, the presence of very homogeneous resources related to supply areas located more than 100 km away has occasionally been identified and is always present in low percentages in most of the assemblages (negrino & starnini, 2003; porraz & peresani, 2006; spinapolice, 2012). raw material collected from far away sites usually arrived at the site as finished tools as part of a personal toolkit. resources other than chert, like quartzite, jasper, silcrete, limestone, are also attested, although their frequency varies from layer to layer and from site to site, suggesting adaptation of these communities to the local landscape. furthermore, several examples demonstrate that a variable part of the tool-kit was made and maintained not only on exogenous materials, but also on old patinated artefacts, collected, exploited or resharpened and used after their first phase of life and the new functional cycle. at fumane, san bernardino and broion caves it seems that the recycling of previously abandoned and patinated flakes was not focused on specific 191 adaptations and cultures of pleistocene humans in italy of life, subsistence, and cultures of these hominins are resumed in the following sections. 6. homo sapiens and the upper palaeolithic 6.1. uluzzian an important role to unveil these dovels of the mpup transition puzzle is played by the uluzzian cultural complex, which spread across the central mediterranean rim in italy and the south of the balkans (moroni et al., 2018; peresani, 2014). traditionally, it is characterized as a lithic and bone technocomplex that produces flakes and blades with pieces that are splintered or backed, crescent-shaped microliths, as well as endscrapers, bone tools and ornamental beads. at the present state of research, the uluzzian follows in time the presumably oldest known cultural expressions associated to homo sapiens in western eurasia, namely the neronian (slimak et al., 2022) and the initial upper palaeolithic (hublin et al., 2020). the uluzzian, in fact, is attributed to modern humans on an anatomical base of two deciduous teeth discovered in the 60ies in cavallo cave (benazzi et al., 2011). along the italian peninsula, the uluzzian is currently best known by its stratigraphic position placed above the mousterian in cave sedimentary sequences, as in northern italian sites. as a matter of fact, the discovery of assemblages at grotta fumane (peresani et al., 2016) and riparo broion (peresani et al., 2019) proved an expansion of its cultural borders further north from what was thought to be exclusively a southern extension. unfortunately, the stratified sites along the ligurian arch (riel-salvatore & negrino, 2018) and along the southern and eastern margins of the po plain (peresani, 2011; karavanić et al., 2018) are lacking of comparable diagnostic evidence. this geographical space constrained from the apennine, the southern alps, the dinarids and the shallow adriatic reach of mis3, features high ecological diversity, and raises its pivotal importance in influencing human migratory routes. furthermore, interactions between different biocultural worlds are relevant evidence for further increasing the frame of the on-going debate regarding the makers of the uluzzian (zilhão et al., 2015; moroni et al., 2018; peresani et al., 2019), and the biological taxonomy of the settlers recognized at fumane (peresani et al., 2022). additional cultural and taphonomic data from the transitional sequence in question are needed. indeed, serious doubts have been cast on the reliability of the stratigraphic position of the teeth found at grotta cavallo (zilhão et al., 2015), based on the lack of data available to ascertain the consistency of the uluzzian sequence from layers eiii to di. cavallo b and cavallo c teeth were discovered in association with anthropically modified faunal remains, knapped stones, bone tools and marine shells which form the foundation for this technocomplex. due to their state of preservation, uniqueness, tiny size and lack of dentine, the teeth cannot be directly radiocarbon dated. however, moroni and colleagues (2018), based on a recent detailed reexamination from the field notes of arturo palma di cesnola, confirmed that they were recovered from undisturbed deposits. to reinforce their finding context, the analysis of two tephra layers, the y6 and campanian ignimbrite, sandwiching the uluzzian at the base (layer fa) and at the top (layer cii) respectively, dispels doubts on the solidity of the uluzzian at grotta cavallo, and sets its duration not earlier than 45.5±1.0 ka bp and not later than 39.85±0.14 ka bp (zanchetta et al., 2018). this date range does not contradict the previous chronometry based on marine shells, charcoal and a probability distribution function for layer eiii (douka et al., 2014) which has now been directly dated to between 44 and 43 cal ka bp (higham et al., 2022), close to the age ranges at broion and fumane. current research focuses on improvements for this resolution to confirm results with greater certainty. however, in accordance with the cultural marked affinities between the southern site and broion mentioned above, it can be asserted that these uluzzians were the first homo sapiens settling italy. despite the lack of any reliable evidence, the provenance of this population is presumably trackable from the near east, notably from its coastal belt. this corridor was traditionally considered to have been well-used by early sapiens population waves since 170 ka (herschowicz et al., 2018). in this extensive debate surrounding the modifications in human societies that occurred in concomitance with the spread of sapiens in europe, a key role is covered by the shell assemblages largely used as ornamental and symbolic objects (vanhaeren & d’errico, 2006). although neanderthals were not unaware of their use at fumane (peresani et al., 2013), the frequency of marine and freshwater shells increases considerably across early upper palaeolithic sites and in inland farther areas located great distances (taborin, 2003; white, 2004). in these sites, the lack of seashells was compensated by freshwater taxa. for instance, the open-air site of kostenki 14 yielded tens of specimens of theodoxus fluviatilis (sinitsyn, 2003). similarity in the use of marine shells has been observed during the uluzzian at both northern and southern sites, as reported at cavallo, la cala and castelcivita. at klissoura cave in greece, where intentionally perforated and/or fractured shells (cyclope neritea, columbella rustica, pecten sp., glycimeris, antalis) were discovered throughout all the uluzzian phases (arrighi et al., 2020a). specifically, antalis from cavallo cave marks similitudes with the very few specimens found at broion associated also to one theodoxus danubialis specimen (arrighi et al., 2020b). hence, the discovery of the uluzzian at fumane and broion confirms that the northern cultural frontier of this complex is an archaeological reality, which dispels doubts of its existence outside the “core” area in southern peninsula, now nullified by the discovery of colle rotondo (villa et al., 2018). furthermore, this revelation stresses the importance of the northern adriatic area as a corridor for attracting the movements of faunal and human groups from the east during the extension of landmass as a consequence of the sea-level mis3 fall. given the co-existence of neanderthals and homo sapiens for around 2,600-5,400 years in europe (higham et al., 2014) or even more (slimak et al., 2022), genetic exchange has been claimed for this period (fu et al., 2016), together with the fact that a possible transmission 192 peresani m. ois, hunted in the site surroundings in a mostly open and patchy woodland landscape under cold climatic conditions. a recent estimation of net primary productivity (npp) reflects how its fluctuations in the prealpine area, where fumane cave is located, affected the biotic resources in contrast to known mediterranean sites. nonetheless, protoaurignacians’ resilience was successful in a mosaic of environments that were affected by significant climate changes and supported rapid dispersal of human groups (marin-arroyo et al., 2023). about the lithic industry, recent studies carried out on the fumane lithic assemblages have contributed to a more precise definition of the protoaurignacian through a high-resolution inspection of the production of blades and bladelets (falcucci & peresani, 2022). this reevaluation revealed that dissociate reduction sequences were addressed to obtain bladelets within a single and continuous knapping from the same core as the result of its progressive reduction. the first goal of production was thus bladelets which did not originate from a broad range of independent core reduction strategies. an additional analysis focusing on carinated core technology furnished further evidence to the theory about a common technological background shared by the protoaurignacian and the early aurignacian (falcucci et al., 2017). in fact, the major difference with the protoaurignacian is the frequency of retouched bladelets, which are much more common in this complex. this emerging view challenges the traditional focus paid on the northern aquitaine basin and raises once again the importance of the mediterranean basin as a region worthy of consideration (gennai, 2021). furthermore, the dense stratigraphic sequence of fumane is stimulating investigations on cultural diachronic variability across the time interval framed by thesecultural units. the goal is to test if the early aurignacian with its new organic artifacts followed the protoaurignacian. data have shown that the protoaurignacian techno-typological features do not switch throughout the stratigraphic sequence and across the heinrich event 4, thus challenging the debated view that environmental deteriorations at the onset of this event explain remarkable differences detected in technologies and human adaptative systems in the early aurignacian by respect to the protoaurignacian (falcucci et al., 2020). by the other hand, the appearance of split-based points in the youngest phase of the sequence at fumane is once again an expression of extensive networks that allowed this technological innovation to spread in italy (tejero & grimaldi 2015) and across different aurignacian regions. 6.3. gravettian, early epigravettian and the last glacial maximum peopling of italy despite their biological and cultural success compared to the previous european “native” populations, upper palaeolithic homo sapiens hunter-gatherers experienced dramatic biological turnovers during the late pleistocene glacial cycle, as attested by discontinuous archaeological record (djindjian et al., 1999, bocquetappel et al., 2005). nonetheless, these last glacial maximum (hereafter lgm) human groups reacted by increasing their resilience at some middle latitudes, but also through migrating at large scale along the corridors of cultural and symbolic behaviours might had occurred between these distinctively acculturated human groups. this being the case, the neanderthal population still remained active during the onset of the uluzzian, not only in western europe with the chatelperronian technocomplex (ruebens et al., 2015), or in some eurasian confined areas like murcia in southern spain (hoffman et al., 2018), but also in corridors like the ligurian arch up to 40.5 cal ka bp (higham et al., 2014). crucially, this is an area where the uluzzian has not been recorded yet. under the light of this evidence, the uluzzian, as a behavioural system developed in southern europe, displaces an intriguing potential for investigating stimulus diffusion and other processes of knowledge transfer in this scenario of coexistence with different humans. this ignites the need to move away from the traditional dichotomy, commonly used to explain the significant cultural phenomena of this phase exclusively as products of one hominin taxon or another. 6.2. protoaurignacian in the kaleidoscopic scenario of the spread of early homo sapiens into western eurasia, the appearance of the aurignacian corresponds to one amongst the most intriguing cultural dynamics of the upper palaeolithic. thus far, research has focused on the origin and chronological expansion of this technocomplex and its arrival to different regions, regardless of the climate and ecological conditions faced by the new incomers (nigst et al., 2014; shao et al., 2021). the homo sapiens populations progressively settled following eastern-northern mediterranean and central-european trajectories (hublin, 2015; mihailović, 2020), bringing with them the diffusion of the new cultural traits represented by portable and cave art, musical instruments (not in italy, yet) and evidence of use of specific categories of symbolic objects for personal purpose, even peculiar of italy (martini, 2007; arrighi et al., 2020; sigari, 2022). for instances, marine shells, collected and modified for making ornaments are one further evidence in support of past human communication behaviour and cultural exchange during this early upper palaeolithic phase (vanhaeren & d’errico, 2006). despite the paucity of marine and freshwater shell assemblages of similar age and composition in southern europe, shells from fumane, bombrini, mochi, castelcivita, partly smeared with red ochre, confirm similarities in the taxonomic composition (peresani et al., 2019; arrighi et al., 2020a). among these elements, shells of homalopoma sanguineum probably played a fundamental role in maintaining a communication system over a large geographic area. they might have represented group consciousness or even longstanding ethnic identities between the rhone basin and the eastern mediterranean regions (vanhaeren & d´errico, 2006; nitu et al., 2019). early modern humans’ subsistence strategies were successful for their dispersal throughout italy despite the mis3 abrupt climatic oscillations and the uneven topographic and ecological conditions. in northern italy one of the first european regions where aurignacians settled (frouin et al., 2022), archaeozoological data indicate seasonal site occupations during late spring/summer. the exploitation was mostly oriented on ibex and cham 193 adaptations and cultures of pleistocene humans in italy connecting european regions. demography and behaviour were thus deeply affected, resulting in the synchronic and diachronic development of a variety of archaeological cultures in different regions and at different times. for this reason, the timing and pattern of multiscalar shifts that occurred from the lgm to the onset of the late glacial (hereafter lg) interstadial (14.7 cal ka bp) are considered among the most important events, also in italy. before 30 ka bp in the alps, glaciers were already growing and reached their maximum extent around 25.0±1.7 cal ka bp (monegato et al., 2017). despite these geographic and climate changes (antonioli & vai, 2004), in southern europe several regions experienced the development of open boreal forests and highly productive wetlands thanks to more favourable conditions supporting (badino et al., in press) which also helped the survival of several mammal species (svenning et al., 2008): here they could thrive while large part of their former distribution areal, in central and northern europe, was covered by ice sheets. in turn, hunters-gatherers groups’ subsistence was favoured by the presence of a rich mammal fauna in these southern refugial areas in turn gave subsistence to hunters-gatherers groups enhancing their capability to maintain large-scale networks (soffer & gamble, 1990; djindjian et al., 1999; moreau, 2009) as attested also by large scale distribution of homalopoma sanguineum shells in the balkans (nitu et al., 2019). as a matter of fact, south of the alpine chain, more favourable conditions allowed the survival and delayed extinction of important consumers like cave bears (terlato et al., 2019a). nonetheless, a full understanding of the way upper palaeolithic groups modulated their biological, cultural and social adaptation to the late pleistocene climate change is still far from being achieved, especially in regions of strategic importance for their geographic position, geomorphological setting and biodiversity. the reason is also due to the low number of archaeological sites that have been radiocarbon-dated to the lgm: these are in western liguria, in the northern and northeastern fringes of the po valley, along the thyrrenian coast and, to the east, in apulia (palma di cesnola, 2001; mussi, 2001) (fig. 3). all of them are either caves or rockshelters, since only one open-air settlement has been excavated so far (mussi & peresani, 2004): these are the piovesello and bilancino sites on the apennine range. at piovesello, a site situated on the watershed of the northern apennine (peresani et al., 2018), unexpected archaeological evidence dated to gs-5 was recovered proving that open, extreme landscapes were the edge of elevational logistical movements of human groups along mountain ecozones. bilancino is a specialized site excavated on a fluvial terrace of the western slope of central apennine (aranguren & revedin, 2008). acquisition strategies of lithic raw materials hint for a well-established territory extended from the central tyrrhenian coasts to across the mountainous chain towards umbria or marche regions, where chert outcrops provided a relevant amount of knappable stone (aranguren et al., 2015). overall, this patchy gravettian archaeological record in italy is to some extent the result of a lack of scientific investigation (palma di cesnola, 2001). site size is also different in the two better investigated areas. some substantial or even large sites are known at sea level in liguria at the balzi rossi. grotta arene candide, further east, is possibly another major site. in southern italy, evidences of human occupation are very scarce in number indeed. grotta paglicci witnessed traces of repeated frequentations and human burials across its long-stratified deposits, thus becoming a reference cultural complex site (palma di cesnola, 2004). following the aurignacian, the gravettian technotypological signatures spread in a rather short time interval across europe (reynolds & green, 2019) and also italy. here, the earliest known gravettian assemblages at the edge of the great po plain are dated at fumane to ca. 35-34 cal ka bp and slightly later at paglicci cave in the southern adriatic region (palma di cesnola, 2004; talamo et al., 2014; falcucci & peresani, 2019). the early gravettian appears in italy to be more homogeneous than the later stages of this technocomplex, being characterized by the presence of backed points and the absence of other typical tool types. after this phase, the adriatic and tyrrhenian records took different cultural trajectories: noailles burins were designed, manufactured and used in western italy as a result of cultural contacts between adjacent regions (santaniello & grimaldi, 2019), but they are missing in the archaeological record of adriatic italy and the balkans (mihailovic & mihailovic, 2007). a key region for human and animal migrations was the great adriatic-po plain (gapr). this vast continental shelf emerged as consequence of the lgm sea level low stand, extending from the western balkan peninsula to peninsular italy (peresani et al., 2021). this area is a paradigmatic case, thanks to its peculiar geographic setting and climatic and ecological variability, which supported refugia for temperate species and witnessed vast movements of populations. the human adaptive flexibility expressed by the gravettian-epigravettian material culture, human mobility, subsistence and symbolic thinking from this region has been the focus of multidisciplinary investigations. in the last decade new paleo-geographic, ecological and anthropogenetic data were obtained from a large set of sources circumscribing the gapr, including the italian prealps, to boost our understanding of the settlement dynamics. summarizing, cultural and petroarchaeometric evidence of chert tools reveal the existence of large-scale circulation patterns across the gapr of finished or semifinished early epigravettian artefacts made of chert coming from the formations of the umbria-marche apennines in the subalpine zone, istria and dalmatia, thus pointing to the gapr as a suitable land for gravettian and epigravettian hunter-gatherers. this point of view was questioned several times since the end of the 80’s of the 20th century. some contrasting positions supported at times the view of a plain seasonally crossed by large migratory herbivores, thus rich in game, water and a variety of resources, especially along water courses, across ecotones, around lakes and on the coastal and estuarine environments. under this light the plain has become more attractive for human populations than the karstic inland, sporadically settled on a strictly seasonal basis and careful planning (peresani et al., 2021, and refer 194 peresani m. middle gravettian are too sparse in the gapr to reconstruct the settlement dynamics in this landscape, a marked trend in the design and circulation of chert artefacts has been highlighted starting with the late gravettian-early epigravettian and up to the early late epigravettian (peresani et al., 2021). this event coincided with a renewal in hunting weaponry around 24 cal ka bp, mainly consisting in the introduction of shouldered points rather than other backed implements. the longence therein). connections between sites located over 250 km apart from another do not contradict the scenario drawn in the innermost continental europe, when hunter-gatherers inhabited with variable continuity cold, cold-temperate and often moister biomes. at the edge of the gapr, stable terraces along the apennine belt were potential areas to settle on a seasonal base or maintain a network of exchanges between different groups. although data about human mobility during the 195 fig. 3 key upper palaeolithic sites in italy: 1) grotte di pradis; 2) altopiano del cansiglio; 3) riparo villabruna; 4) riparo dalmeri; 5) riparo del broion; 6) covolo di trene e grotta di paina; 7) grotta di fumane; 8) riparo tagliente; 9) balzi rossi; 10) grotta della basura; 11) arene candide; 12) piovesello; 13) bilancino; 14) grotta la fabbrica; 15) fosso mergaoni e grotta della ferrovia; 16) fonte delle mattinate; 17) grotta polesini; 18) colle rotondo; 19) grotta paglicci; 20) serino; 21) grotta di castelcivita; 22) grotta della cala; 23) grotta della serratura; 24) grotta del romito; 25) grotta di santa maria di agnano; 26) grotta del cavallo e grotte della baia di uluzzo; 27) grotta delle veneri; 28) grotta romanelli; 29) grotta san teodoro; 30) grotta dell'addaura (source http://tinitaly.pi.ingv.it; elab. by d.delpiano).. adaptations and cultures of pleistocene humans in italy range circulation of these points encompasses several macro-regions of europe and could be related to new mobility strategies or changes in human groups and their way of exploiting resources in this territory. around 24 cal ka bp, the early epigravettian replaced the former technocomplex in coincidence of the gi-2, a climatic threshold marking major cultural changes in western eurasia (ruiz-redondo et al., 2022). extensive renewals in the variety of marine species used as ornaments are recorded only during the late epigravettian, hence leaving incertitude on a wide chronological range (martini ed., 2007). paleogenetic studies focusing on gravettian and post-gravettian hunter-gatherer individuals, combined with fine resolution radiocarbon chronologies and cultural data allow a better comprehension of the population dynamics that accompanied modern human reexpansion towards the end of the lgm. specifically, biomolecular data reveal that several population transformations took place across europe, with reduced diversity in mtdna during the lgm, but also survival of european maternal gene pool (fu et al., 2016; posth et al., 2016). in this scenario, a population turnover took place around 18 cal ka and well before the lg interstadial, as revealed from genetic discontinuity due to the spread of individuals of the villabruna cluster (an individual retrieved in riparo villabruna, dated to 14.2-13.8 cal ka bp; aimar et al., 1992), sharing distinctive affinity to present-day populations from the near east. additional genome-wide data have been achieved from the analysis of the individual from riparo tagliente, so essential to understand the distribution of such ancestry through time in southern european climatic refugia (bortolini et al., 2021). this incoming genetic component largely replaced the ancestry identified also in older magdalenian-related individuals from central europe (fu et al., 2016) and supports the hypothesis that, from at least 19 -18 cal ka bp, european populations were broadly interconnected across the gapr and beyond. 6.4. late-glacial, the submersion of the gapr and the spread of epigravettian hunter-gatherers after the last glacial maximum, the changes of vegetation and animal distribution viewed the peopling of italy as a gradual process marked by the progressive colonization of new territories following (naudinot et al., 2014; vescovi et al., 2017) and coinciding with the spread of the epigravettian. this cultural complex consists in an ensemble of industries following the gravettian until the end of the pleistocene. as stated above, the reaction of human groups to the lgm physical and ecological turnovers deeply contributed to the shaping of our present genetic ancestry. in the gapr, the end of the lgm lgm witnessed, also in lowlands, quick geomorphological changes due to the corresponding collapse after 18 cal ka bp of the alpine glaciers, starting their final withdrawal. the effects of these modifications on human occupation along river terraces in the plain are not yet detectable. conversely, at the northern edge of the gapr in the prealpine foothills, riparo tagliente was a location persistently settled by human groups for the exploitation of local biotic and abiotic resources which marks one of the first steps of the pioneering colonization of the inner mountain belt on relatively stable areas (fontana et al., 2009). evidence of this phase is however scanty. such scarcity of data hampers the reconstruction of the peopling of the italian eastern alps and dinarides triggered by the climatic amelioration of the lg interstadial starting at 14.7/14.5 cal ka bp. in the lg interstadial, the progressive rise of the adriatic coastline combined to the expansion of the treeline up to 1700-1800 m a.s.l. in the se-alps (vescovi et al., 2007) are among the key factors leading human groups to intensely occupy the interior mountain ranges along new routes and to expand their settlements (bertola et al., 2007; naudinot et al., 2014) (fig. 3). late epigravettian penetration, firstly limited to valley floors and high plateaus around 500 m above modern sea level (amsl), reached mid-altitude territories during the second part of the lg interstadial with the full development of a logistical occupation network at the ecotone between coniferous woods and alpine prairies (bertola et al., 2007). this organisation corresponds to a seasonal mobility strategy based on sites that are functionally complementary to each other and located at different altitudes. regarding the faunal target, the most exploited game was ibex, which is the dominant species in dalmeri rock shelter and other midaltitude sites (tagliacozzo and fiore, 2000), alongside with marmots, systematically exploited in the pradis plateau (romandini et al., 2012; nannini et al., 2022). lithic industries evolved towards a progressive simplification of the production systems, associated with the persistence of standardized lithic backed tools used as projectile implements in response to specific functional requirements and constraints (duches et al., 2018; montoya et al., 2018). other than the alpine slope, the general increase of evidence and radiocarbon datataset at the beginning of the greenland interstade 1 (gi-1), has been interpreted as the result of a major change in the socio-economic system of epigravettian groups. changes in lithic technology occurred during this period are likely to be associated with some major modifications of the mobility patterns with clear increase of task-oriented sites and a global multiplication of the sites. evidence is sparse all over italy, but morefrequent in the ligurian arch, eastern alps, northern and central apennine, sicily and patches along the thyrrenian and adriatic coasts. in liguria, an exceptional ichnosite is the cave of básura near toirano, where about thirty footprints dated to 14 cal ka bp are referred to a small group of visitors (avanzini et al., 2021). the pleistocene-holocene transition also marked a major turnover in the history of the environment and prehistoric peopling of high latitude regions as much as mountain territories. after the gi-1, the progressive decrease in temperatures in coincidence of the greeenland stade 1 (gs-1: 12.9-11.7 cal ka bp), gave rise to a set of modifications with which the hunter-gatherers related. the spread of hunter-gatherers is recorded with variable details in the alps, the eastern sector, and the central apennine, which were the scenarios of extensive research on human occupation since the 1970’s. the archaeological record shows a relative scarcity of sites with evidence of gs-1 occupation, contrasting with the 196 peresani m. references agam a., barkai r. (2018) elephant and mammoth hunting during the palaeolithic: a review of the relevant archaeological, ethnographic and ethnohistorical records. quaternary, 1(3), 1-28. doi: 10. 3390/ quat1 010003 aimar a., alciati g., broglio a., castelletti l., cattani l., d'amico c., giacobini g., maspero a., peresani m. (1992) les abris villabruna dans la vallée du cismòn. preistoria alpina, 28(1), 227-254. aleo a., duches r., falcucci a., rots v., peresani m. (2021) scraping hide in the early upper palaeolithic: insights into the life and function of the protoaurignacian endscrapers at fumane cave. archaeological and anthropological sciences, 13(8), 137. antonioli f., vai g.b. (eds.) (2004) litho-paleoenvironmental maps of italy during the last two climatic extremes. explanatory notes, enea. aranguren b., revedin a. (eds.) (2008) bilancino : a 30,000 years ago camp-site in mugello, florence. istituto italiano di preistoria e protostoria, firenze. aranguren b., cavulli f., d'orazio m., grimaldi s., longo l., revedin a., santaniello f. (2015) territorial exploitation in the tyrrhenian gravettian italy: the case-study of bilancino (tuscany). quaternary international, 359-360, 442-451. aranguren b., grimaldi s., benvenuti m., capalbo c., cavanna f., cavulli f., ciani f., comencini g., giuliani c., grandinetti g., mariotti lippi m., masini f., mazza p.p.a., pallecchi p., santaniello f., savorelli a., revedin a. (2019) poggetti vecchi (tuscany, italy): a late middle pleistocene case of human-elephant interaction. journal of human evolution, 133, 32-60. doi: 10.1016/j.jhevol.2019.05.013 arrighi s., bortolini e., tassoni l., benocci a., manganelli g., spagnolo v., foresi l., bambini a.m., lugli f., badino f., aureli d., boschin f., figus c., marciani g., oxilia g., silvestrini s., cipriani a., romandini m., peresani m., ronchitelli a., moroni a., benazzi s. (2020) backdating systematic shell ornament making in europe to 45,000 years ago. archaeological and anthropological sciences, 12(59). doi: 10.1007/s12520-019-00985-3 arrighi s., moroni a., tassoni l., boschin f., badino f., bortolini e., boscato p., crezzini j., figus c., forte m., lugli f., marciani g., oxilia g., negrino f., riel-salvatore j., romandini m., spinapolice e.e., peresani m., ronchitelli a., benazzi s. (2020) bone tools, ornaments and other unusual objects during the middle to upper palaeolithic transition in italy. quaternary international, 551, 169-187. doi: 10.1016/j.quaint.2019.11.016 arsuaga j.l., martínez i., gracia a., lorenzo c. (1997) the sima de los huesos crania (sierra de atapuerca, spain). a comparative study. journal of human evolution, 33(2-3), 219-281. arzarello m., pavia g., peretto c., petronio c., sardella major record available for both the gi-1 and the greenlandian in the same region. although gs-1 climatic cooling had an impact on vegetation (vescovi et al., 2007), apparently it had only a limited effect on the exploitation of the middle altitude mountain landscape. compared to gi-1 sites, gs-1 valley floor sites are characterized by the increase of roe deer in the spectrum of hunted faunas, while at higher elevations they document the prevalent predation of ibex and to a lesser extent deer (fiore & tagliacozzo, 2006). evidence of smaller newlyestablished human settlements has been interpreted as resources stress in the human adaptation to mountain environment (mussi & peresani, 2011), and as reflecting shorter visits to this area, within a continuous but distinct use of resources, also through adoption of caching behaviour related to a higher mobility pattern (peresani, 2006). in continuity with the epigravettian, the early mesolithic colonization covered the central-eastern italian alpine region, as attested by archaeological evidence richer than in any other mountain district of europe (montoya et al., 2018 and references therein). the sauveterrian settlement system model was in accordance with a seasonal nomadism between highland and lowland camps located on the main valley bottoms, next to small lakes and/or sheltered under erratic boulders, attesting a varied functionality from residential camps to ephemeral short-term foraging task sites, intended to be exploited as different proximal ecological niches. site variability thus reflects human mobility within a given system of gathering food or exploiting resources seasonally, mostly based on the hunting of ungulates (red deer, roe deer, wild boar, ibex and chamois), complemented with other smaller prey like pikes and cyprinids, sweet water molluscs, and marsh turtles in the valley bottoms (wierer & boscato, 2006; bazzanella et al., 2007). 7. conclusions the pleistocene human peopling of italy was a complex process developed under the influence of different geographic and climatic contexts since the end of the early pleistocene. their impact on the biology and culture of pre-heidelbergensis, heidelbergensis, neanderthal and sapiens scavengers and hunter-gatherers has been reconstructed through an ensemble of proxies, with more and more increasing detail for the late pleistocene latest attestations. human biological turnovers do not support exclusive explanation of the variability of behavioural, economic and cultural aspects, which are expressed sometimes across chronologically constrained sequences and claim for a wider approach to disentangle the origin of cultural change and innovative behaviours. italy is a potential context for providing clues for an in-depth inspection of the relations between different hominin groups and taxa. acknowledgements the author is grateful to two reviewers for contributions to ameliorate the manuscript and to g.cattabriga for editing the text. 197 adaptations and cultures of pleistocene humans in italy r. (2012) evidence of an early pleistocene hominin presence at pirro nord (apricena, foggia, southern italy): p13 site. quaternary international, 267, 56-61. avanzini m., salvador i., starnini e., arobba d., caramiello r., romano m., citton p., rellini i., firpo m., zunino m., negrino f. (2021) following the father steps in the bowels of the earth: the ichnological record from the bàsura cave (upper palaeolithic, italy). in: pastoors, a., lenssen-erz, t. (eds.), reading prehistoric human tracks. springer, cham. 251-276. doi: 10.1007/978-3-030-60406-6_14 badino f., pini r., ravazzi c., margaritora d., arrighi s., bortolini e., figus c., giaccio b., lugli f., marciani g., monegato g., moroni a., negrino f., oxilia g., peresani m., romandini m., ronchitelli a., spinapolice e.e., zerboni a., benazzi s. (2020) an overview of alpine and mediterranean palaeogeography, terrestrial ecosystems and climate history during mis 3 with focus on the middle to upper palaeolithic transition. quaternary international, 551, 7-28. doi: 10.1016/j.quaint.2019.09.024 badino f., pini r., ravazzi c., chytrý m., bertuletti p., bortolini e., dudová l., peresani m., romandini m., benazzi s. (in press) high-resolution ecosystem changes pacing the millennial climate variability at the middle to upper palaeolithic transition in ne-italy. nature scientific reports. barkai r. (2021) the elephant in the handaxe: lower palaeolithic ontologies and representations. cambridge archaeological journal, 31(2), 349-361. doi.org/10.1017/s0959774320000360 benazzi s., douka k., fornai c., bauer c.c., kullmer o., svoboda j., pap i., mallegni f., bayle p., coquerelle m., condemi s., ronchitelli a., harvati k., weber g.w. (2011) early dispersal of modern humans in europe and implications for neanderthal behaviour. nature, 479, 525-528. benazzi s., slon v., talamo s., negrino f., peresani m., bailey s.e., sawyer s., panetta d., vicino g., starnini e., mannino m.a., salvadori p.a., meyer m., pääbo s., hublin j.j. (2015) the makers of the protoaurignacian and implications for neandertal extinction. science, 348(6236), 793-796. huguet r., vallverdú j., rodríguez-álvarez x.p., te r rad i l l os -berna l m. , barga l l ó a . , lombera-hermida a., menéndez l., modestomata m., van der made j., soto m., blain h.-a., garcía n., cuenca-bescós g., gómez-merino g., pérez-martínez r. a, b, expósito i., allué e., rofes j., burjachs f., canals a., bennásar m., nuñezlahuerta c., bermúdez de castro j.m., carbonell e. (2017) level te9c of sima del elefante (sierra de atapuerca, spain): a comprehensive approach. quaternary international, 433, 278-295. bermúdez de castro j.m., martinón-torres m., gómezrobles a., prado-simón l., martín-francés l., lapresa m., olejniczak a., carbonell e. (2011) early pleistocene human mandible from sima del elefante (te) cave site in sierra de atapuerca (spain): a comparative morphological study. journal of human evolution 61(1), 12-25. bertola s., broglio a., cassoli p., cilli c., cusinato a., dalmeri g., de stefani m., fiore i., fontana f., giacobini g., guerreschi a., gurioli f., lemorini c., liagre j., malerba g., montoya c., peresani m., mocci ris a., rossetti p., tagliacozzo a., ziggiotti s. (2007) l’epigravettiano recente nell’area prealpina e alpina orientale. in: martini f. (eds.), l’italia tra 15.000 e 10.000 anni fa, cosmopolitismo e regionalità nel tardoglaciale. millenni. studi di archeologia preistorica. museo fiorentino di preistoria, 5, 39-94. bocquet-appel j.p., demars p.y., noiret l., dobrowsky d. (2005) estimates of upper palaeolithic metapopulation size in europe from archaeological data. journal of archaeological science, 32, 16561668. bona f., peresani m., tintori a. (2007) indices de fréquentation humaine dans les grottes à ours au paléolithique moyen final. l’exemple de la caverna generosa dans les préalpes lombardes, italie. l’anthropologie, 111(3), 290-320. doi: 10.1016/j.anthro.2007.05.003 bortolini e., pagani l., oxilia g., posth c., fontana f., badino f., saupe t., montinaro f., margaritora d., romandini m., lugli f., papini a., boggioni m., perrini n., oxilia a., aiese cigliano r., barcelona r., visentin d., fasser n., arrighi s., figus c., marciani g., silvestrini s., bernardini f., menghi sartorio j.c., fiorenza l., moggi cecchi j., tuniz c., kivisild t., gianfrancesco f., peresani m., scheib c.l., talamo s., d’esposito m., benazzi s. (2021) early alpine occupation backdates westward human migration in late glacial europe. current biology, 31(11), 2484-2493. boscato, p., gambassini, p., ranaldo, f., ronchitelli, a. (2011) management of paleoenvironmental resources and raw materials exploitation at the middle palaeolithic site of oscurusciuto (ginosa, southern italy): units 1 and 4. in: conard n.j. & richter j. (eds.), neanderthal lifeways, subsistence and technology one hundred fifty years of neanderthal study. verlag ed., 87-98. buzi c., di vincenzo f., profico a., manzi g. (2021) the pre-modern human fossil record in italy from the middle to the late pleistocene: an updated reappraisal. alpine and mediterranean quaternary, 34(1), 17-32. cerilli e., fiore i. (2018) natural and anthropic events at la polledrara di cecanibbio (italy, rome): some significant examples. alpine and mediterranean quaternary, 31, 55-58. chelli cheheb r., arzarello m., arnaud j., berto c., cáceres i., caracausi s., colopi f., daffara s., montanari canini g., huguet r., karambatsou t., sala b., zambaldi m., berruti g.l.f. (2019) human behavior and homo-mammal interactions at the first european peopling: new evidence from the pirro nord site (apricena, southern italy). the science of nature, 106(16), 1-22. delpiano d., heasley k., peresani m. (2018) assessing neanderthal land use and lithic raw material management in discoid technology. journal of 198 peresani m. nal resources by neanderthals at grotta di fumane, unit a9. quaternary international, 421, 134153. doi: 10.1016/j.quaint.2015.11.142. fiore i., tagliacozzo a. (2006) lo sfruttamento dello stambecco nel tardiglaciale di riparo dalmeri (tn): il livello 26c. archaeozoological studies in honour of alfedo riedel, 59-76. fontana f., moncel m.h., nenzioni g., onorevoli g., peretto c., combier j. (2013) widespread diffusion of technical innovations around 300,000 years ago in europe as a reflection of anthropological and social transformations? new comparative data from the western mediterranean sites of orgnac (france) and cave dall’olio (italy). journal of anthropological archaeology, 32, 478-498. fontana f., cilli c., cremona m. g., giacobini g., gurioli f., liagre j., malerba g., rocci ris a., veronese c., guerreschi a. (2009) recent data on the late epigravettian occupation at riparo tagliente, monti lessini (grezzana, verona): a multidisciplinary perspective, preistoria alpina, 44, 49-58. frouin m., douka k., krishna dave a., schwenninger j.l., mercier n., murray a.s., santaniello f., boschian g., grimaldi s., higham t. (2022) a refined chronology for the middle and early upper palaeolithic sequence of riparo mochi (liguria, italy). journal of human evolution, 169, 103211. fu q., posth c., hajdinjak m., petr m., mallick s., fernandes d., furtwängler a., haak w., meyer m., mittnik a., nickelb., peltzer a., rohland n., slon v., lazaridis i., lipson m., schiffels s., skoglund p., gély b., benazzi s., gonzales morales m.r., peresani m., straus l.g., caramelli d., lari m., ronchitelli a., valentin f., constantin s., coppola d., grigourescu d., neugebauermaresch c., thevenet c., wehrberger k., crevecoeur i., rougier h., semal p., cupillard ch., bocherens h., mannino m., conard n.j., harvati k., moiseyev v., drucker d.g., svoboda j . , pinhasi r., kelso j., patterson n.,. krause j., pääbo s., reich d. (2016) the genetic history of ice age europe. nature, 534, 200-205. doi: 10.1038/nature17993 gennai j. (2021) back to the lithics: technological comparison of early upper palaeolithic assemblages from al-ansab/ jordan, româneşti dumbrăviţa/ romania and fumane/ italy. ph.d., dissertation, universität zu köln, köln. hershkovitz i., weber g.w., quam r., duval m., grün r., kinsley l., ayalon a., bar-matthews m., valladas h., mercier n., arsuaga j.l., martinóntorres m., maría bermúdez de castro j., fornai c., martín-francés l., , sarig r., may h., , krenn v.a., slon v., rodríguez l., garcía r., , lorenzo c., miguel carretero j., frumkin a., shahackgross r., bar-yosef mayer d.e., cui y., wu z., peled n., groman-yaroslavski i., weissbrod l., yeshurun r., tsatskin a., zaidner y., weinsteinevron m. (2018)the earliest modern humans outside africa. science, 359, 456-459. anthropological science, 96, 1-22. doi: 10.4436/jass.96006 delpiano d., zupancich a., peresani m. (2019) innovative neanderthals: results from an integrated analytical approach applied to backed stone tools. journal of archaeological science, 110, 105011. doi: 10.1016/j.jas.2019.105011 delpiano d., peresani m., bertola s., cremaschi m., zerboni a. (2019) lashed by the wind. short-term middle palaeolithic occupations within the loesspalaeosoil sequence at monte netto (northern italy). quaternary international, 502, 137-147. doi: 10.1016/j.quaint.2019.01.026 delpiano d., zupancich a., bertola s., martellotta e.f., livraghi a., cristiani e., peresani m. (2022) flexibility within quina lithic production systems and tool-use in northern italy: implications on neanderthal behavior and ecology during early mis 4. archaeological and anthropological sciences, 14, 219. doi: 10.1007/s12520-022-01684-2 djindjian f., kozłowski j.k., otte m. (1999) le paléolithique supérieur en europe. colin ed. paris. douka k., higham t.f.g., wood r., boscato p., gambassini p., karkanas p., peresani m., ronchitelli a. (2014) on the chronology of the uluzzian. journal of human evolution, 68, 1-13. doi: 10.1016/j.jhevol.2013.12.007 douka k., spinapolice e. (2012) neanderthal shell tool production: evidence from middle palaeolithic italy and greece. journal of world prehistory, 25, 4579. duches r., peresani m., pasetti p. (2018) success of a flexible behavior. considerations on the manufacture of late epigravettian lithic projectile implements according to experimental test. archaeological and anthropological sciences, 10, 1617-1643. doi: 10.1007/s12520-017-0473-x falcucci a., conard n.j., peresani m. (2017) a critical assessment of the protoaurignacian lithic technology at fumane cave and its implications for the spread of modern humans into europe. plosone, 12(12), e0189241. doi: 10.1371/journal.pone.0189241 falcucci a., conard n.j., peresani m. (2020) breaking through the aquitaine frame: a re-evaluation on the significance of regional variants during the early upper palaeolithic as seen from a key record in southern europe. journal of anthropological sciences, 98, 99-140. doi: 10.4436/jass98021 falcucci a., peresani m. (2019) a pre-heinrich event 3 assemblage at fumane cave and its contribution for understanding the beginning of the gravettian in italy. quartär, 66, 135-154. doi: 10.7485/qu66_6 falcucci a., peresani m. (2022) the contribution of integrated 3d model analysis to protoaurignacian stone tool design. plos one, 17(5), e0268539. doi: 10.1371/journal.pone.0268539 fiore i., gala m., romandini m., cocca e., tagliacozzo a., peresani m. (2016) from feathers to food: reconstructing the complete exploitation of avifau 199 adaptations and cultures of pleistocene humans in italy higham t., douka k., wood r., bronk ramsey c., brock f., basell l., camps m., arrizabalaga a., baena j., barroso-ruíz c., bergman c., boitard c., boscato p., caparrós m., conard n., draily c., froment a., galván b., gambassini p., grimaldi s., haesaerts p., holt b., iriarte-chiapusso m.j., jelinek a., jordá pardo j., maíllo-fernández j.m., marom a., maroto j., menéndez m., metz l., garcia-moreno a., morin e., moroni a., negrino f., panagopoulou e., peresani m., pirson s., de la rasilla m., riel-salvatore j., ronchitelli a., santamaria d., semal p., slimak l., soler j., soler n., villaluenga a., villaverde v., pinhasi r., jacobi r., 2014, the timing and spatio-temporal patterning of neanderthal disappearance. nature, 512, 306309. doi: 10.1038/nature13621 higham t., frouin m., douka k., ronchitelli a., boscato p., benazzi s., crezzini j., spagnolo v., mccarty m., arrighi s., schwenninger j.l., moroni a., boschin f. (2022) exploring spatio-temporal variation in the disappearance of neanderthals in the italian peninsula using high precision radiocarbon dating and bayesian modelling. paleoanthropology, 2, 421-617. doi: 10.48738/2022.iss2.809 hoffmann d.l., angelucci d.e., villaverde v., zapata j., zilhão j. (2018) symbolic use of marine shells and mineral pigments by iberian neandertals 115,000 years ago. science advances 4, eaar5255. hublin j.j. (2015) the modern human colonization of western eurasia: when and where? quaternary science reviews, 118, 194-210. doi: 10.1016/j.quascirev.2014.08.011 hublin j.j., sirakov n., aldeias v., sirakov n., aldeias v., bailey s., bard e., delvigne v., endarova e., fagault y., fewlass h., hajdinjak m., kromer b., krumov y., marreiros j., martisius n.l., paskulin l., sinet-mathiot v., meyer m., pääbo s., popov v., rezek z., sirakova s., skinner m.m., smith g.m., spasov r., talamo s., tuna s., wacker l., welker f., wilcke a., zahariev n., mcpherron s., tsanova t. (2020) initial upper palaeolithic homo sapiens from bacho kiro cave, bulgaria. nature, 581, 299-302. doi: g/10.1038/s41586-020-2259-z jaubert j., maureille b., peresani m. (2022) spiritual and symbolic activities of neanderthals. in: romagnoli f., rivals f., benazzi s. (eds.), updating neanderthals. elsevier monographies, 261-274. karavanić i., vukosavljević n., janković i., ahern j.c.m., smith f.h. (2018) palaeolithic hominins and settlement in croatia from mis 6 to mis 3: research history and current interpretations. quaternary international, 494, 152-166. kuhn s.l., 1990. diversity within uniformity: tool manufacture and use in the ‘pontinian’ mousterian of latium (italy) (ph.d. dissertation). university of new mexico. lari m., di vincenzo f., borsato a., ghirotto s., micheli m., balsamo c., collina c., de bellis g., frisia s., giacobini g., gigli e., hellstrom j.c., lannino a., modi a., pietrelli a., pilli e., profico a., ramirez o., rizzi e., vai s., venturo d., piperno m., lalueza-fox c., barbujani g., caramelli d., manzi g. (2015) the neanderthal in the karst: first dating, morphometric, and paleogenetic data on the fossil skeleton from altamura (italy). journal of human evolution, 82, 88-94. lemorini c., santucci e., caricola i., nucara a., nunziante‑cesaro s. (2022) life around the elephant in space and time: an integrated approach to study the human‑elephant interactions at the late lower palaeolithic site of la polledrara di cecanibbio (rome, italy). journal of archaeological method and theory. doi: 10.1007/s10816-022-09584-4 manzi g. (2016) humans of the middle pleistocene: the controversial calvarium from ceprano (italy) and its significance for the origin and variability of homo heidelbergensis. quaternary international, 411, 254-261. manzi g., magri d., palombo m.r. (2011) early-middle pleistocene environmental changes and human evolution in the italian peninsula. quaternary science reviews, 30(11-12), 1420-1438. marciani g., ronchitelli a., arrighi s., badino f., bortolini e., boscato p., boschin f., crezzini j., delpiano d., falcucci a., figus c., lugli f., oxilia g., romandini m., riel-salvatore j., negrino f., peresani m., spinapolice e.e., moroni a., benazzi s. (2020) lithic techno-complexes in italy from 50 to 39 thousand years bp: an overview of lithic technological changes across the middle-upper palaeolithic boundary. quaternary international, 551, 123-149. doi: 10.1016/j.quaint.2019.11.005 margaritora d., dozio a., chelidonio g., turrini m.c., peresani m. (2020) the lower and middle palaeolithic settlements in the baldo-lessini mountains. results from a gis investigation. alpine and mediterranean quaternary, 33(1), 115-132. doi: 10.26382/amq.2020.13 marín-arroyo a.b., terlato g., vidal-cordasco m., peresani m. (2023) subsistence of the early modern humans in europe: the protoaurignacian occupations at fumane cave. nature scientific reports, 13, 3788. doi: 10.1038/s41598-023-30059-3 martini f. (ed.) (2016) l’arte paleolitica e mesolitica in italia. millenni, studi di archeologia preistorica, museo fiorentino di preistoria “paolo graziosi”, firenze, 12. martini f. (ed.) (2007) l’italia tra 15.000 e 10.000 anni fa. cosmopolitismo e regionalità nel tardoglaciale. millenni, studi di archeologia preistorica, museo fiorentino di preistoria “paolo graziosi”, firenze, 5. mietto p., panarello a., di vito m.a. (2022) 2001-2021: vent’anni di ricerche sulle “ciampate del diavolo”. dalla leggenda alla realtà scientifica. miscellanea ingv, 64, pp. 244. mihailović d. (2020) push-and-pull factors of the middle to upper palaeolithic transition in the balkans. quaternary international, 551, 47-62. 200 peresani m. tremolada f., cremaschi m., peretto c. (2011) first dated human occupation of italy at ~0.85 ma during the late early pleistocene climate transition. earth planetary science letters, 307, 241e-252. doi: 10.1016/j.epsl.2011.05.025 muttoni g., scardia g., kent d.v. (2018) early hominins in europe: the galerian migration hypothesis. quaternary science reviews, 180, 1-29. nannini n., duches r., fontana a., romandini m., boschin f., crezzini j., peresani m. (2022) marmot hunting during the upper palaeolithic: the specialized exploitation at grotte di pradis (italian pre-alps). quaternary science reviews, 277, 107364. doi: 10.1016/j.quascirev.2021.107364 naudinot n., tomasso a., tozzi c., peresani m (2014) changes in mobility patterns as a factor of 14c date density variation in the late epigravettian of northern italy and southeastern france. journal of archaeological science, 52, 578-590. negrino f., starnini e. (2003) patterns of lithic raw material exploitation in liguria from the palaeolithic to the copper age, préhistoire du sud-ouest, supplément 5, 235-243. nigst p.r., haesaerts p., damblon f., frank-fellner c., mallol c., viola b., götzinger m., niven l., trnka g., hublin j.j. (2014) early modern human settlement of europe north of the alps occurred 43,500 years ago in a cold steppe-type environment. proceedings national academy of science of usa, 111, 14394-14399. doi: 10.1073/pnas.1412201111 nițu e.c., cârciumaru m., nicolae a., cîrstina o., lupu f.i., leu m. (2019) mobility and social identity in the mid upper palaeolithic: new personal ornaments from poiana cireșului (piatra neamț, romania). plos one, 14(4), e0214932. doi: 10.1371/journal.pone.0214932 palma di cesnola a. (1996) le paléolithique inférieur et moyen en italie. ed. millon. palma di cesnola a. (2001) le paléolithique supérieur en italie. préhistoire d’europe 9, jérôme millon, grenoble. palma di cesnola a. (ed.) (2004) paglicci. l'aurignaziano e il gravettiano antico. grenzi ed., foggia. palombo m.r. (2010) a scenario of human dispersal in the northwestern mediterranean throughout the early to middle pleistocene. quaternary international, 223-224, 179-194. doi: 10.1016/j.quaint.2009.11.016 panagopoulou e., tourloukis v., thompson n., konidaris g., athanassiou a., giusti d., tsartsidou g., karkanas p., harvati k. (2018) the lower palaeolithic site of marathousa 1, megalopolis, greece: overview of the evidence. quaternary international, 497, 33-46. doi: 10.1016/j.quaint.2018.06.031 panarello a., palombo m.r., di vito m.a., biddittu i., farinaro g., mietto p. (2020) on the devil tracks: unexpected news from the foresta ichnosite (roccamonfina volcano, central italy). journal of quaternary science, 35(3), 444456. pereira a., nomade s., falguères c., bahain j.j., tommihailović d., mihailović b. (2007) considérations sur le gravettien et l’epigravettien ancien des balkans de l’ouest. paléo, 19, 115-130. moncel m.h., santagata c., pereira a., nomade s., voinchet p., bahain j.j., daujeard c., curci a., lemorini c., hardy b., eramo g., berto c., raynal j.p., arzarello m., mecozzi b., iannucci a., sardella r., allegretta i., delluniversità e., terzano r., dugas p., jouanic g., queffelec a., d’andrea a., valentini r., minucci e., carpentieri l., piperno m. (2020) the origin of early acheulean expansion in europe 700 ka ago: new findings at notarchirico (italy). scientific reports, 10(1), 116. monegato g., scardia g., hajdas i., rizzini f., piccin a. (2017) the alpine lgm in the boreal icesheets game. nature scientific reports 7(2078). montoya c. (2008) evolution des concepts de productions lithiques et artistiques à l’epigravettien récent: analyses de collections des préalpes de la vénétie et des préalpes du sud françaises. in: mussi m. (eds.), il tardiglaciale in italia. lavori in corso. british archaeological reports, 1859, 43-55. montoya c., duches r., fontana f., peresani m., visentin d. (2018) peuplement tardiglaciaire et holocène ancien des préalpes de la vénétie (italie nord orientale): éléments de confrontation. in: averbouh a., bonnet-jacquement p., cleyet-merle j.-j. (eds.), l’aquitaine à la fin des temps glaciaires. paleo, numéro spécial, 193-202. moreau l. (2009) geißenklösterle. das gravettien der schwäbischen alb im europäischen kontext. kerns verlag. tübingen. moroni a., ronchitelli a., arrighi s., aureli d., bailey s.e., boscato p., boschin f., capecchi g., crezzini j., douka k., marciani g., panetta d., ranaldo f., ricci s., scaramucci s., spagnolo v., benazzi s., gambassini p. (2018) grotta del cavallo (apulia southern italy). the uluzzian in the mirror. journal of anthropological science, 96, 125-160. doi: 10.4436/jass:96004 mussi m. (2001) earliest italy. an overview of the italian palaeolithic and mesolithic. new york: kluwer academic/plenum publishers. mussi m., peresani m. (2004) the peopling of northern italy at the lgm. in: antonioli f., vai g.b. (eds.), climex maps italy. explanatory notes, enea, 5960. mussi m., peresani m. (2011) human settlement of italy during the younger dryas. quaternary international, 242(2), 360-370. muttillo b., lembo g., gallotti r. (2021) lithic productions during the first half of the middle pleistocene (mis 19-12) in the italian peninsula: an overview. alpine and mediterranean quaternary, 34(1), 3354. muttoni g., scardia g., kent d.v., swisher c.c., manzi g. (2009) pleistocene magnetochronology of early hominin sites at ceprano and fontana ranuccio, italy. earth and planetary science letters, 286(1-2), 255-268. muttoni g., scardia g., kent d.v., morsiani e., 201 adaptations and cultures of pleistocene humans in italy bret o., garcia t., voinchet p., bulgarelli m. g., anzidei a. p. (2017) 40ar/39ar and esr/u-series data for the la polledrara di cecanibbio archaeological site (lazio, italy). journal of archaeological science: reports, 15, 20-29. doi: 10.1016/j.jasrep.2017.05.025 peresani m. (2006) flint caches and raw material economy in the late upper palaeolithic and early mesolithic of the eastern italian alps. in: g.körlin, g.weisgerber (eds.) stone age mining age. proceedings of the viii international flint symposium, bochum, germany, der anschnitt. zeitschrift für kunst und kultur in bergbau, beiheft 19, 173182. peresani m. (2011) the end of the middle palaeolithic in the italian alps. an overview on neandertal land -use, subsistence and technology. in: conards n., richter j. (eds.), neanderthal lifeways, subsistence and technology. one hundred fifty years of neanderthal study. vertebrate paleobiology and paleoanthropology series, springer ed., 249-259. peresani m. (2014) l’uluzzien en italie. in: otte m. (ed.), néandertal/cro-magnon. la rencontre. editions errance, arles, 61-80. peresani m. (2022) inspecting human evolution from a cave. late neanderthals and early sapiens at grotta di fumane: present state and outlook. journal of anthropological sciences, 100, 71-107. doi: 10.4436/jass.10016 peresani m., bertola s., caricola i., nunziante cesaro s., duches r., ferretti p., margaritora d., marrocchino e., eftekhari n., vaccaro c., zupancich a., cristiani e. (2021) late neanderthal’s taste for the green and flat pebbles. journal of anthropological archaeology, 64, 101368. doi: 10.1016/j.jaa.2021.101368 peresani m., bertola s., delpiano d., benazzi s., romandini m. (2019) the uluzzian in the north of italy. insights around the new evidence at riparo broion rockshelter. archaeological and anthropological sciences, 11(7), 3503-3536. doi: 10.1007/s12520-018-0770-z peresani m., boldrin m., pasetti p. (2015) assessing the exploitation of double patinated artifacts during the late mousterian. implications for lithic economy and human mobility in the north of italy. quaternary international, 361, 238-250. doi: 10.1016/j.quaint.2014.10.058 peresani m., cristiani e., romandini m. (2016) the uluzzian technology of grotta di fumane and its implication for reconstructing cultural dynamics in the middle upper palaeolithic transition of western eurasia. journal of human evolution, 91, 3656. doi: 10.1016/j.jhevol.2015.10.012 peresani m., duches r., miolo r., romandini m., ziggiotti s. (2011) small specialized hunting sites and their role in epigravettian subsistence strategies. a case study in northern italy. p@lethnology, 3, 251-266. peresani m., fiore i., gala m., romandini m., tagliacozzo a. (2011) late neandertals and the intentional removal of feathers as evidenced from bird bone taphonomy at fumane cave 44ky bp, italy. proceedings national academy of sciences of the united states of america, 108, 3888-3893. doi: 10.1073/pnas peresani m., forte m., quaggiotto e., colonese a.c., romandini m., cilli c., giacobini g. (2019) marine shell exploitation in the early upper palaeolithic. re-examination of the shell assemblages from fumane cave (ne italy). paleoanthropology, 64-81. doi: 10.4207/pa.2019.art124 peresani m., monegato g., ravazzi c., bertola s., margaritora d., breda m., fontana a., fontana f., janković i., karavanic i., komšo d., mozzi p., pini r., furlanetto g., de amicis g.m.m., perhoč z., posth c., ronchi l., rossato s., vukosavljević n., zerboni a. (2021) hunter-gatherers across the great adriatic-po region during the last glacial maximum: environmental and cultural dynamics. quaternary international, 581, 128-163. doi: 10.1016/j.quaint.2020.10.007 peresani m., ravazzi c., pini r., margaritora d., cocilova a., delpiano d., bertola s., castellano l., fogliazza f., martino g., nicosia c., simon p. (2018) human settlement and vegetation-climate relationships in the greenland stadial 5 at the piovesello site (northern apennines, italy). quaternary research, 90(3), 503-528. doi: 10.1017/qua.2018.76 peresani m., vanhaeren m., quaggiotto e., queffelec a., d’errico f. (2013) an ochered fossil marine shell from the mousterian of fumane cave, italy. plosone, 8(7), e68572. doi: 10.1371/journal.pone.0068572 peretto c., amore f.o., antoniazzi a., antoniazzi a., bahain j.j., cattani l., cavallini e., esposito p., falguéres c., gagnepain j., hedley i.g., pugliese m., renault-miskovsky j., sozzi m., ungaro s., vannucci s., verges j.m., wagner j.j., yokoyama y. (1998) l'industrie lithique de cà belvedere di monte poggiolo: stratigraphie, matiére premiére, typologie, remontages et traces d’utilisation. l'anthropologie, 102, 343-465. peretto c., arnaud j., moggi-cecchi j., manzi g., nomade s., pereira a., falguères c., bahain j.l., grimaud-hervé d., berto c., sala b., lembo g., muttillo b., gallotti r., thun hohenstein u., vaccaro c., coltorti m., arzarello m. (2015) a human deciduous tooth and new 40ar/39ar dating results from the middle pleistocene archaeological site of isernia la pineta, southern italy. plos one, 10(10), e0140091. doi: 10.1371/journal.pone.0140091 porraz g., peresani m. (2006) occupations du territoire et exploitation des matières premières: présentation et discussion sur la mobilité des groupes humains au paléolithique moyen dans le nord-est de l’italie. in: bressy c., burke a., chalard p., lacombe s., martin h. (eds.) notions de territoire et de mobilité. exemples de l’europe et des premières nations en amérique du nord avant le contact européen. ètudes et recherches archéologiques de l’universitè de liège, liége, 116, 11-21. 202 peresani m. at grotta di fumane, italy: a zooarchaeological contribution to the reconstruction of neanderthal ecology. quaternary international, 337, 11-27. doi: 10.1016/j.quaint.2014.03.027 romandini m., peresani m., gurioli f., sala b. (2012) marmota marmota, the most predated species at grotta del clusantin. insights from an unusual case-study in the italian alps. quaternary international, 252, 184-194. doi: 10.1016/j.quaint.2011.03.016 romandini m., peresani m., laroulandie v., metz l., pastoors a., vaquero m., slimak l. (2014b) convergent evidence of eagle talons used by late neanderthals in europe: a further assessment on symbolism. plos one, 9(7), e101278. doi: 10.1371/journal.pone.0101278 romandini m., terlato g., nannini n., tagliacozzo a., benazzi s., peresani m. (2018a) bears and humans, a neanderthal tale. reconstructing uncommon behaviors from zooarchaeological evidence in southern europe. journal of archaeological science, 90, 71-91. doi: 10.1016/j.jas.2017.12.004 romandini m., thun hohenstein u., fiore i., tagliacozzo a., perez a., lubrano v., terlato g., peresani m. (2018b) late neandertals and the exploitation of small mammals in northern italy: fortuity, necessity or hunting variability? in: brugal j.ph. (ed.), 4th icaz taphonomy working group meeting. general to specific quaternary taphonomy. session 2: human and animal predation, paris. quaternaire, 29(1), 61-67. rubini m., cerroni v., festa g., sardella r., zaio p. (2014) a revision of hominin fossil teeth from fontana ranuccio (middle pleistocene, anagni, frosinone, italy). journal of human evolution, 77, 204-216. ruebens k., mcpherron s.j., hublin j.j. (2015) on the local mousterian origin of the châtelperronian: integrating typo-technological, chronostratigraphic and contextual data. journal of human evolution, 86, 55-91. ruiz-redondo a., vukosavljević n., tomasso a., peresani m., davies w., vander linden m. (2022) mid and late upper palaeolithic in the adriatic basin: chronology, transitions and human adaptations to a changing landscape. quaternary science reviews, 276, 107319. doi: 10.1016/j.quascirev.2021.107319 santaniello f., grimaldi s. (2019) le gravettien entre l’italie et la france : nouvelles données sur l’industrie lithique de l’abri mochi (balzi rossi, italie). bulletin de la société préhistorique française, 116, 255-282. santucci e., marano f., cerilli e., fiore i., lemorini c., palombo m.r., anzidei a.p., bulgarelli g.m. (2016) palaeoloxodon exploitation at the middle pleistocene site of la polledrara di cecanibbio (rome, italy). quaternary international, 406, 169182. doi: 10.1016/j.quaint.2015.08.042 shao y., limberg h., klein k., wegener c., schmidt i., weniger g.c., hense a., rostami m. (2021) posth c., renaud g., mittnik a., drucker d.g., rougier h., cupillard c., valentin f., thevenet c., furtwängler a., wißing c., francken m., malina m., bolus m., lari m., gigli e., capecchi g., crevecoeur i., beauval c., flas d., germonpré m., van der plicht j., cottiaux, r., gély b., ronchitelli a., wehrberger k., grigorescu d., svoboda j., semal p., caramelli d., bocherens h., harvati k., conard n.j., haak w., powell a., krause j. (2016) pleistocene mitochondrial genomes suggest a single major dispersal of non-africans and a late glacial population turnover in europe. current biology, 26, 827-833. reynolds n., green c. (2019) spatiotemporal modelling of radiocarbon dates using linear regression does not indicate a vector of demic dispersal associated with the earliest gravettian assemblages in europe. journal of archaeological science reports, 27, 101958. riel-salvatore j., negrino f. (2018) human adaptations to climatic change in liguria across the middle-upper palaeolithic transition. journal of quaternary science, 33(3), 313-322. rolfo m.f., bini m., di mario f., ferracci a., giaccio b., hsun-ming h., ilaria i., sadori l., shen c.c., vignola c., zanchetta g. (in press) neanderthal bones collected by hyena at grotta guattari, central italy, 66-65 ka: u/th chronology and paleoenvironmental setting. quaternary science reviews. romagnoli f., baena j., sarti l. (2016) neanderthal retouched shell tools and quina economic and technical strategies: an integrated behaviour. quaternary international 407, 29-44. romagnoli f., gómez de soler b., bargalló a., chacón m.g., vaquero m. (2018) here and now or a previously planned strategy? rethinking the concept of ramification for micro-production in expedient contexts: implications for neanderthal socioeconomic behavior. quaternary international 474, 168-181. romagnoli f., chabai v., gravina b., hérisson d., hovers e., moncel m.h., peresani m., uthmeier t., bourguignon l., chacón mg., di modica k., faivre j.p., kolobova k., malinski-buller a., neruda p., rios garaizar j., weiss m., wiśniewski a., wragg sykes r. (2022) neanderthal technological variability: a wide-ranging geographical perspective of the final middle palaeolithic. in: romagnoli f., rivals f., benazzi s. (eds.), updating neanderthals. elsevier monographies, 163204. romandini m., crezzini j., bortolini e., boscato p., boschin f., carrera l., tagliacozzo a., terlato g., arrighi s., badino f., figus c., lugli f., marciani g., oxilia g., moroni a., negrino f., peresani m., riel-salvatore j., ronchitelli a., spinapolice e.e., benazzi s. (2020) macromammal and bird assemblages of late middle to upper palaeolithic transition in italy: an extended zooarchaeological review. quaternary international, 551, 188-223. doi: 10.1016/j.quaint.2019.11.008 romandini m., nannini n., tagliacozzo a., peresani m. (2014a) the ungulate assemblage from layer a9 203 adaptations and cultures of pleistocene humans in italy human-existence probability of the aurignacian techno-complex under extreme climate conditions. quaternary science reviews, 263, 106995. doi: 10.1016/j.quascirev.2021.106995 sigari d. (2022) palaeolithic rock art of the italian peninsula. centro camuno di studi preistorici, archivi 21, 1st ed., pp. 272. sinitsyn a. (2003) a palaeolithic pompeii at kostenki. antiquity, 295, 9-14. slimak l., zanolli c., higham t., frouin m., schwenninger j.l., arnold l.j., demuro m., douka k., mercier n., guérin g., valladas h., yvorra p., giraud y., seguin-orlando a., orlando l., lewis j.e., muth x., camus h., vandevelde s., buckley m., mallol c., stringer c., metz l. (2022) modern human incursion into neanderthal territories 54,000 years ago at mandrin, france. science advances 8: eabj9496. doi: 10.1126/sciadv.abj9496 soffer o., gamble c. (eds.) (1990) the world at 18000 bp. high latitudes. unwin hyman, london, volume 1. soriano s, villa p. (2017) early levallois and the beginning of the middle palaeolithic in central italy. plos one. 2017; 2, e0186082. spinapolice e.e. (2012) raw material economy in salento (apulia, italy): new perspectives on neanderthal mobility patterns. journal of archaeological science, 39, 680-689. svenning j.c., normand s., kageyama m. (2008) glacial refugia of temperate trees in europe: insights from species distribution modelling. journal of ecology, 96, 1117-1127. taborin y. (2003) la mer et les premiers hommes modernes. in: vandermeersch b. (ed.) échanges et diffusion dans la préhistoire méditerranéenne. actes congrés cths, paris, 113-122. talamo s., peresani m., romandini m., duches r., jéquier c., nannini n., pastoors a., picin a., vaquero m., weniger g.c., hublin j.j. (2014) detecting human presence at the border of the northeastern italian pre-alps. 14c dating at rio secco cave as expression of the first gravettian and the late mousterian in the northern adriatic region. plos one, 9(4), e95376. tejero j.m, grimaldi s. (2015) assessing bone and antler exploitation at riparo mochi (balzi rossi, italy): implications for the characterization of the aurignacian in south-western europe, journal of archaeological science, 61, 59-77. terlato g., bocherens h., romandini m., nannini n., hobson k.a., peresani m. (2019a) chronological and isotopic data support a revision for the timing of cave bear extinction in mediterranean europe. historical biology, 31(4), 474-484. doi: 10.1080/08912963.2018.1448395 terlato g., livraghi a., romandini m., peresani m. (2019b) large bovids on neanderthal menu: exploitation of bison priscus and bos primigenius in northeastern italy. journal of archaeological science: reports, 25, 129-143. doi: 10.1016/j.jasrep.2019.04.006 terlato g., lubrano v., romandini m., marín-arroyo a.b., benazzi s., peresani m. (2021) late neanderthal subsistence strategies at san bernardino cave (berici hills northeastern italy) inferred from zooarchaeological data. alpine and mediterranean quaternary, 34(2), 213-235. doi: 10.26382/amq.2021.10 vanhaeren m., d’errico f. (2006) aurignacian ethnolinguistic geography of europe revealed by personal ornaments. journal of archaeological sciences, 33, 1105-1128. doi: 10.1016/j.jas.2005.11.017 vescovi e., ravazzi c., arpenti e., finsinger w., pini r., valsecchi v., wick l., ammann b., tinner w. (2007) interactions between climate and vegetation during the lateglacial period as recorded by lake and mire sediment archives in northern italy and southern switzerland. quaternary science reviews, 26(11-12), 1650-1669. villa p., boschian g., pollarolo l., saccà d., marra f., nomade s., pereira a. (2021) elephant bones for the middle pleistocene toolmaker. plos one 16 (8): e0256090. doi: 10.1371/journal.pone.0256090 villa p., pollarolo l., conforti j., marra f., biagioni c., degano i., lucejko j.j., tozzi c., pennacchioni m., zanchetta g., nicosia c., martini m., sibilia e., panzeri l. (2018) from neandertals to modern humans: new data on the uluzzian. plos one, 13(5), e0196786. villa p., soriano s., grün r., marra f., nomade s., pereira a., boschian g., pollarolo l., fang fang, bahain j.j. (2016) the acheulian and early middle palaeolithic in latium (italy): stability and innovation. plos one 11(8): e0160516. doi: 10.1371/journal.pone.0160516 white r. (2004) observations technologiques sur les objets de parure. in: schmider b. (ed.) l’aurignacien de la grotte du renne. gallia préhistoire, xxxiv supplément, cnrs, paris, 257-266. zanchetta g., giaccio b., bini m., sarti l. (2018) tephrostratigraphy of grotta del cavallo, southern italy: insights on the chronology of middle to upper palaeolithic transition in the mediterranean. quaternary science reviews, 182, 65-77. zanolli c., martinón-torres m., bernardini f., boschian g., coppa a., dreossi d., mancini l., de pinillos m.m., martín-francés l., bermúdez de castro j.m., tozzi c., tuniz c., macchiarelli r. (2018) the middle pleistocene (mis 12) human dental remains from fontana ranuccio (latium) and visogliano (friuli-venezia giulia), italy. a comparative high resolution endostructural assessment. plos one, 13(10), e0189773. zilhão j., banks w.e., d’errico f., gioia p. (2015) analysis of site formation and assemblage integrity does not support attribution of the uluzzian to modern humans at grotta del cavallo. plosone 10(7), e0131181. ms. received: march 2, 2023 revised: may 23, 2023 accepted: may 24, 2023 available online: may 27, 2023 204 peresani m. ojs 730 monegato et al 127-148.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 36 (2), 2023, 127-148 the early and middle pleistocene glaciations in the alps giovanni monegato 1, franco gianotti 2, susan ivy-ochs 3, jürgen m. reitner 4, giancarlo scardia 1, 5, naki akçar 6 1 institute of geosciences and earth resources, national research council, padova, italy. 2 dipartimento di scienze della terra, università di torino, torino, italy. 3 laboratory of ion beam physics, eth zurich, zurich, swiss. 4 geosphere austria, department geologische kartierung / geological mapping, vienna, austria. 5 universidade estadual paulista (unesp), instituto de geociências e ciências exatas, rio claro sp, brazil. 6 institut für geologie, universität bern, bern, swiss. corresponding author: giovanni monegato <giovanni.monegato@igg.cnr.it> abstract: the alps experienced extensive glaciations during many pleistocene cold stages. new stratigraphic and geochronological data gathered in the last decade depict the early pleistocene glaciations and their record is continuously updated. the onset of major glaciations since the late matuyama chron (mis 22-20) is better recognized in many end moraine systems along the southern side of the alps. the updated chronology of the middle pleistocene phases indicates an improvement of the knowledge about the penultimate glaciation (mis 6) and the evidence that every sector has had its own most extensive glaciation in a different time span. the dissimilar architecture of the end moraine systems suggests a different behavior of the glaciers from one cold stage to the others. the development of the largest glacier networks with associated piedmont lobes (i.e., adige, adda and likely inn) required abundant snow supply promoted by the southerly circulation, like in the lgm. for the systems with the highest accumulation areas (i.e., valais, dora baltea, rhine-reuss and ticino-toce) a larger number of glacial units was recorded likely because these were more sensitive to every circulation regime impacting the alps, whether northwest or south dominated. the alps remain the most studied mountain range with respect to quaternary glaciations, thereby providing a unique and valuable resource. keywords: quaternary glaciations, european alps, early-middle pleistocene, palaeomagnetism, glacigenic deposits. 1. introduction the european alps (fig. 1) have been the key site for the development of the idea of multiple quaternary glaciations since the milestone work of penck & brückner (1901-1909). the study of the glacial history of the alps began earlier, in the xix century (e.g., agassiz, 1840; morlot, 1854; omboni, 1861; de mortillet, 1861; gastaldi, 1865; taramelli, 1875; sacco, 1887; mühlberg, 1896; wannier, 2023), and since that time this mountain range has represented a major field laboratory for new theories and methodological advances in glacial stratigraphy and geochronology. the alpine terminal moraine systems, also known as morainic amphitheaters, occur at the outlet of the major alpine valleys and are primary sites for the study of quaternary glaciations (penck et al., 1894) and developing one of the major knowledge advance in quaternary studies (orombelli et al., 2023). their morphostratigraphic architecture was studied by penck & brückner (1901-1909), who defined four climatostratigraphic units and correlated them across the alps. accordingly, this study gave birth to a new paradigm in ice age history of the earth: four alpine glaciations (from older to younger: günz, mindel, riss, and würm) and the intervening “interglacials”. their definition based on glacial sequences consisting of terminal moraines and proglacial outwash terraces stands as a milestone in geoscientific research, not only for the alps but also for elsewhere in eurasia (e.g., krūkle & stelle, 1964; grosswald et al., 1994; lehmkuhl et al., 2011) and worldwide (cotton, 1963). for a long time, definition and correlation of the glacial and glaciofluvial deposits were mostly made by combining the weathering degree and geomorphological evidence (e.g. the altitudinal concordance of the distribution of glaciofluvial terraces), where topographic elevation is a key for a relative stratigraphic framework (e.g., bini, 1997). subsequent stratigraphic studies, since the 1970s, focused on facies analysis and bounding surfaces, leading to the identification of important discontinuities (including buried soils and interglacial/interstadial peat layers), casting new light on the age of old glaciations and questioning the reliability of the four glaciations paradigm (bowen, 1978; billard & orombelli, 1986; schlüchter, 1981; 1986). based on marine and ice cores, the development of the marine isotope stage (mis) stratigraphy documented up to fifty cold stages (shackleton & pisias, 1985; lisieki & raymo, 2005) during the pleistocene (sensu gibbard et al., 2010) raising the question if and how the four-glaciation model https://doi.org/10.26382/amq.2023.07 could have been applicable (e.g., billard & derbyshire, 1985; šibrava et al., 1986; billard & orombelli, 1986; schlüchter, 1988). with this change of perspective, in the alps, a minimum of 15 different glacier advances were then recognized in the swiss foreland (preusser et al., 2011; schlüchter et al., 2020), and about 11 in the central southern foreland sectors (bini et al., 2014; gianotti et al., 2015). among these, 13 and 7 respectively, are ascribable to the early and middle pleistocene (schlüchter et al., 2020; ivy-ochs et al., 2022). considering the lack of chronostratigraphic information for many early-middle pleistocene glacial units (hughes et al., 2020) and their geographical distribution we can pose several questions, such as: how many glacier advances could have been recorded in the circum-alpine area? which were the major ones (i.e. foreland reaching)? did alpine glaciers have comparable extents in each cold phase? the alps were also the playground for testing new geochronological tools during the last three decades, leading to several attempts to place the glacier advances within the framework of marine isotope stages, also considering the ongoing uplift of the alps (champagnac et al., 2007; scardia et al., 2006; 2012; sternai et al, 2019). moreover, the remarkable regional dissimilarities in term of number of glacier advances from one sector to another (ivy-ochs et al., 2022), reflect the differences in the morphological and sedimentary archives, due to variations in tectonic regimes (uplift vs. subsidence), accommodation space, and preservation potential. such conditions have an impact on the choice of suitable stratigraphic approach (litho-, morpho-, allostratigraphy) and in most cases also on the terminology of glaciations (chronostratigraphy, climatostratigraphy). this demands the development of new approaches in order to disentangle the stratigraphic puzzle, and its meaning in terms of paleoclimate vs. tectonic evolution of the alps. apart from the late pleistocene advances, encompassing the würm (chaline & jerz, 1984; monegato & ravazzi, 2018), the early and middle pleistocene glacial units still need further investigation. the present review is aimed at describing the architecture of early to middle pleistocene glacial units across the alps and discussing the major questions related to their distribution. 2. background studies as the cradle of the quaternary glaciation concept, the alps have a long-lasting history of studies concerning when and how mountain glaciers became a vast ice field during the pleistocene. the moraine amphitheaters in the piedmont area at the outlet of the major alpine valleys have been the site for countless studies since the early researches and also today represent key areas for reconstructing alpine glaciations. starting from the pioneering works by venetz (1833), agassiz (1840) and de charpentier (1841), in which the idea of glaciers reaching the lowlands was developed, a large number of scholars examined in depth the glacial landforms and deposits all around the alps. at the beginning, a single cold phase was assumed for the deposition of the moraines (e.g., venetz, 1833; martins & gastaldi, 1850; bruno, 1877) on the basis of lithostratigraphical description, including the outwash deposits. however, very soon evidence for multiple glaciations was reported from the lake geneva area (morlot, 1854), the swiss alpine forelands (mühlberg, 1896), the northern foreland (e.g., penck, 1882; blaas, 1884; penck et al., 1894) (fig. 2a), and the southern alpine foreland (nicolis, 1899; capeder, 1904). with their milestone work, penck & brückner (1901-1909) described different suites of gravel accumulation that were connected upstream to moraines (fig. 2c), recognizing four glaciations all across the circum-alpine area (fig. 2b). the four fold glaciation paradigm was, after its publication, quickly accepted and applied in regional studies and maps. some authors added more “glaciations” to the list according to older gravel accumulation suites (eberl, 1930; schaefer, 128 fig. 1 reference areas for the alpine pre-lgm glaciation in the european alps. main glacier catchments numbered as in tab. 1. monegato g. et al. in the northern foreland, the gravel units at stadlerberg and irchel (fig. 3b) in northern switzerland represent the early phase of the deckenschotter accumulation at 2.6 ±0.1 ma (claude et al., 2017; 2019; dieleman et al., 2022). this is in agreement with the occurrence of mimomys cf. pliocaenicus (irchel site, bolliger et al., 1996) which belongs to the gelasian/tiglian mn17 unit of the european land mammals zones. these gravels are interpreted as glaciofluvial units, thus as evidence of an early extensive glaciation that occurred already by 2.6 ma in the northern side the alps. actually the deckenschotter sequence at irchel is made of a number of different units, whose ages suggest a cut and fill evolution of the northern foreland during the early pleistocene (dieleman et al., 2022). in the swiss foreland an overall eight glaciations are suggested for the early pleistocene by schlüchter et al. (2020), which should include the late matuyama. the deckenschotter is interpreted as the glaciofluvial sediments related to this time span also in the german sector of the alpine foreland (älteste deckenschotter in german stratigraphy); there deckenschotter is attributed to be the outwash deposition of biber and donau glaciations (ellwanger et al., 2011; doppler et al., 2011), notwithstanding some disagreements (see fiebig et al., 2011). the first dating attempt of deckenschotter in the german sector provided the age of 2.35+1.08 -0.88 ma (häuselmann et al., 2007) that could be considered quite comparable to the deckenschotter chronology at irchel despite the large analytic uncertainty. in the western sector, evidence of cold stages is testified only by loess deposition along the rhone valley, south of lyon (bourdier, 1963) and biostratigraphically ascribed to 2.2 ma (guerin, 1980; billard & orombelli, 1986). around the plio-pleistocene boundary, the southern side of the alps was characterized by transitional and marine deposits (“villafranchian”; carraro et al., 1996; ), overlain by conglomerate (ceppo) in the lombardy sector (e.g., nangeroni, 1940; venzo, 1950; orombelli, 1979; zuccoli, 2000; bini et al., 2004a). the former belongs to the gelasian in the adda sector based on palaevegetation (venzo, 1950; corselli et al., 1985; pini et al., 2002) and in the verbano sector (bini et al., 1997). the first glacier advance is testified by immacolata and vivirolo formations in the verbano sector and tentatively ascribed by magnetostratigraphy (uggeri et al., 1997) to the gauss-matuyama geomagnetic reversal (2.58 ma; gradstein et al., 2020). actually, the magnetostratigraphy presented by uggeri et al. (1997) can be equally correlated to the jaramillo late matuyama (c1r.1n-c1r.1r) reversal (0.99 ma, see next section), and the associated glacigenic deposits could be ascribed to a late matuyama glaciation. lacking independent chronologic constraints, the age of the earliest glacigenic deposits in the verbano sector remains an open issue. conglomerate successions that mark the increase of sediment production and delivery are present in the prealpine valleys from the orobic to the julian alps and prealps, some of them were ascribed to the early pleistocene by means of palaeobotanic content and stratigraphic relationships (monegato & stefani, 2011; martinetto et al., 2012; bini et al., 2015; monegato 1956; schreiner & ebel, 1981; glückert, 1974; doppler et al., 2011) or split the four glaciations into subunits (e.g., venzo, 1965, 1977; carraro et al., 1970). this fact created some ambiguities in correlating glacial/ glaciofluvial units from one site to another, even if contiguous. the new field surveys, based on the allostratigraphic approach, revealed these differences by the difficulty of tracing lateral boundaries (e.g., bini et al., 2004a, 2004b, 2015), which led to a splitting of the regional alpine stratigraphy into local, independent stratigraphic frameworks over the swiss and italian sectors (e.g., preusser et al., 2011; graf & burkhalter, 2016; fioraso et al., 2021; ivy-ochs et al., 2022, and references therein). on the other hand, in the germanaustrian area, the penck & brückner (1901-1909) subdivision has been maintained because of the physical correlation of glaciofluvial terraces in the piedmont area and along the further catchment of the danube river (ellwanger et al., 2011; doppler et al., 2011; van husen & reitner, 2011a; ivy-ochs et al., 2022; reitner, 2022). within the general architecture of the moraine suites in the circum-alpine area thick sequences of conglomerates were also included, known as deckenschotter (cover gravels in german) on the northern side of the alps (du pasquier, 1891; frei, 1912; graf, 1993). in the southern side, coarse-grained gravel deposits, known as ceppo, were partially ascribed to glaciofluvial sedimentation based on petrographic composition (e.g., venzo, 1950; 1957). the systematic and multidisciplinary study of several cores in the southern alpine foreland yielded during the last two decades a more comprehensive framework for the onset of “major” glaciations and the midpleistocene revolution (muttoni et al., 2003, 2007; scardia et al., 2006, 2010, 2012). concurrently, the chronostratigraphy of the swiss deckenschotter in the northern alpine foreland was progressively improved with employment of new dating techniques all based on cosmogenic nuclides. these include the depth profile, burial and isochron-burial dating techniques, with the latter as well applying the p-pini age calculation model (akçar et al., 2014, 2017; claude et al., 2017, 2019; knudsen et al., 2020; dieleman et al., 2022). this new deckenschotter chronology outlines three major accumulation phases at ca. 2.5 ma, ca. 1.5 ma, and ca. 1 ma (fig. 3a-c). 3. glaciations at the plio-pleistocene boundary the earliest evidence of quaternary glaciation in the northern hemisphere is documented at the end of the pliocene (ca. 2.7 ma) by the first occurrence of icerafted debris in north atlantic oceanic sediments (thierens et al., 2012; bailey et al., 2013). terrestrial evidence is related to the earliest major waxing of the laurentide ice sheet (lis) at ca. 2.4 ma and correlated with mis 100 (balco & rovey, 2010). data about the alpine ice fields for that period are scarce (batchelor et al., 2019), although the alps had already achieved an elevation high enough to host large glaciers (e.g., pignalosa et al., 2011; kuhlemann & rahn, 2013; winterberg & willett, 2019; krsnik et al., 2021; dieleman et al., 2022). 129 the early and middle pleistocene glaciations in the alps & poli, 2015). a burial age to 1.86 ±0.19 ma was provided in the sava valley on conglomerate complex ascribed to glaciofluvial environment (mihevc et al., 2015). in the southern foreland, characterized by the transition to marine environments (scardia et al., 2006; garzanti et al., 2011), indications of cold phases triggering alluvial 130 fig. 2 a) map of the southern bavaria by penck (1882) in which the author depicted multiple glacial advances in the alps; b) cross sections correlating glacial units of the end moraine systems with glaciofluvial terraces in the northern foreland depicted by penck and brückner (1901-1909). c) glacial sequence as defined by penck & brückner (1901-1909). monegato g. et al. deckenschotter (upper older cover gravels) at zusamplatte (ausburg) recorded the b/m reversal (doppler et al., 2011); the glaciofluvial deposits were ascribed to the early pleistocene also for the presence of tiglian mammal fauna (königswald & heinrich, 2007). the same attribution, because of reverse polarity, was given to the aggradation were detected in many sites through sediment core analysis (ambrosetti et al., 1980; ravazzi et al., 2005, 2009; scardia et al., 2006; 2010; bini et al., 2015). the ceppo units were ascribed to glaciofluvial deposition during the early pleistocene (bini, 1997). according to the available data, glaciers could have developed during this period in the highest sectors of the alps (keller & krayss, 2010; preusser et al., 2011; van husen & reitner, 2011a) without directly reaching the foreland, but enhancing the development of widespread alluvial and braided systems at the outlets of alpine valleys, because of the increased sediment supply and water discharges. such processes enabled the formation of loess in the alpine foreland, as recorded in the loess archives of stranzendorf, showing the onset of loess at the g/m boundary and kremsschießstätte starting with the olduvai event (fink et al., 1976; fink & kukla, 1977). moreover, the occurrence of trunk valley glaciers is still debated as the carving of major valleys occurred later, starting from the late matuyama (häuselmann et al., 2007; valla et al., 2011). 4. late matuyama glaciations (mis22-20) according to muttoni et al. (2003) the “major” glaciations in the southern side of the alps started at about 0.9 ma when extensive boreal ice sheets expanded (batchelor et al., 2019; greenwood et al., 2022). for “major” we mean a climatic stage which was cold and long enough to allow the glaciers to spread out from the main alpine valleys, forming piedmont lobes in the foreland at both the sides of the mountain range. in the northern foreland, the till interbedded with deckenschotter at the swiss feusi site (fig. 3a) was dated to 0.9 ±0.1 ma with the p-pini cosmogenic nuclide burial-dating model for glacial deposits (after knudsen et al., 2020). in addition, two deckenschotter sites attributed to the steig gravels (sensu graf, 1993) at irchel were dated to 0.9 ±0.2 and 1.3 ±0.1ma using isochron-burial dating technique with cosmogenic 26al and 10be (claude et al., 2019; dieleman et al., 2022). in the german-austrian foreland, the lichtenegg diamicton (menzies & ellwanger, 2010; ellwanger et al., 2011) and the finegrained deposits intercalated with the glacial till at pfullendorf (bibus et al., 1996; doppler et al., 2011) were ascribed to the early pleistocene based on reverse polarity. fluvial deposits related to the älterer deckenschotter (older cover gravels) (ellwanger et al., 1995, 2011) at altheiligenberg showed reverse polarity (fromm, 1989). the covering loess of the hohere älterer 131 fig. 3 a) outcrop of deckenschotter at feusi (switzerland) (28 in fig. 1). weakly cemented, in part cross-bedded, gravels interbedded with a 2-m-thick till layer (beige unit in the center left of photograph). numerous glacially striated clasts have been found in this till layer. the deposit is capped by deeply weathered till, likely middle pleistocene in age (haldimann et al., 2017). calculated 10be-26al isochron-burial age of the till is 1.3-0.9 ma (grischott et al., 2020; knudsen et al., 2020); b) outcrop of deckenschotter at irchel (steig gravels sensu graf, 1996) (28 in fig. 1). steig gravels were dated to 0.9 ±0.1 ma by isochron-burial dating with cosmogenic 10be and 26al (claude et al. 2019; dieleman et al., 2022); c) outcrop of deckenschotter siglistorf. calculated 10be-26al isochron-burial age of these gravels is1.5 ±0.2 ma (akçar et al., 2017) (29 in fig. 1); d) close-up view of bünten till in the bünten gravel pit at möhlin, canton of basel (29 in fig. 1). this till dates back to 0.5 ±0.1 ma by isochron-burial dating with cosmogenic 10be and 26al (dieleman et al., 2022). hammer on the picture is for scale; e) weathering horizon on top of weisse nagelfluh (white conglomerate) overlain by graue nagelfluh (grey conglomerate; proglacial deposits of the günz glaciation) indicating a stable surface under supposed interglacial conditions (location: kremsmünster, site 19 in fig. 1, height of the outcrop approximately 4 m). the early and middle pleistocene glaciations in the alps langenloiser terrace of the danube (van husen & reitner, 2011a). the eichwaldschotter glaciofluvial unit in the salzach piedmont area was tentatively ascribed to mis 22 (van husen & reitner, 2011 a, b), because of the similarity in facies and presence of lithologies of the typical glaciofluvial sediments of the middle pleistocene. according to the evidence from the northern and southern sides, trunk valleys hosted valley glaciers that likely originated from ice domes located in the axial sector of the alps. in the northern swiss foreland, the glacial deposits interbedded into the deckenschotter point to an extension of the glaciers similar to but somewhat more extensive than the lgm (cf. frei, 1912; graf, 1993; doppler et al., 2011; ellwanger et al., 2011; knudsen et al., 2020). in the southern side, the first major glaciation has been chronologically constrained by magnetostratigraphy in the po plain subsurface and occurred in the late matuyama chron, between the end of the jaramillo (0.99 ma) and the beginning of the brunhes chron (0.78 ma; muttoni et al., 2003, 2007; scardia et al., 2006, 2012). based on this chronostratigraphic framework, reverse magnetizations in glacigenic deposits (carraro et al., 1991; scardia et al., 2010, 2015; graf, 2019) have fig. 4 a) the 500 km2 wide ivrea morainic amphitheatre (ima) (site 2 in fig. 1) represented by dtm (courtesy of the piedmont region) extends to the outlet of the dora baltea valley (db). the bedrock crops out in the ima inner sector in the granulite ivrea hills (ih) and in the outer western sector in the monti pelati peridotite reliefs (mp). the serra d'ivrea lateral moraines, the inner depression (id) and the outer outwash plain (op) are pointed out. the dora baltea river flows out of the ima through the mazzé gorge (ma). at the northeastern edge the bessa roman gold mine (be) extends into a sector previously occupied by the two oldest glacigenic units. white square indicates the location of the geological map showed in b. b) geological sketch map of the ima left lateral north-eastern sector, which retains the largest number of recognized glacigenic units in the ima. the pre-lgm glacigenic succession is divided in seven synthems referred to as many glaciations ranging from the end of early pleistocene to the late pleistocene. the bornasco and montino units separated by an interstadial layer (2) are regarded to as subsynthems. the ivrea synthem referred to the lgm is split into internal serra (ise, max lgm advance), piverone (piv), palazzo (pal) and andrate (and) subsynthems. c) geological cross-section of the ima lateral north-eastern sector (from gianotti et al., 2015, modified). profile trace is shown in b (blue line). interstadial or interglacial markers are indicated with asterisks: 1) bosa palaeosol; 2) sorgente solfurea peat layer; 3) comunità palaeosol; 4) gianetto gyttja layer. the glacigenic sequence is tentatively related to the pleistocene glaciations. possible hypotheses are proposed for magnano and external serra units. the correlation is made with the global isotopic curve from lisiecki & raymo (2005), which is a synthesis of 57 benthic marine oxygen isotope records. chronological boundaries between marine isotope stages (mis) are reported. 132 monegato g. et al. produced the spread of the glaciers. considering the size of the laurentide ice sheet (lis) and the european ice sheet (eis), a circulation model similar to the one that produced the alpine lgm (florineth & schlüchter, 2000; luetscher et al., 2015; monegato et al., 2017) can be supposed. however, the narrative of this period (761242 ka bp, between mis 18 and mis 8 cold stages) strongly suffers from lack of chronologic constraints, and glacial units are best grouped as pre-lgm deposits with normal magnetic polarity. in the swiss sector, in addition to field evidence, paleobotanical data and luminescence dating were the basis for distinguishing three major glacial units: möhlin, habsburg and hagenholz glaciations (preusser et al., 2011; schlüchter et al., 2020). several detailed studies on boreholes led to the conclusion that the middle pleisbeen confidently ascribed to a late matuyama glaciation and allowed to infer the spatial distribution of the first morainic landforms in the alpine foreland, even if they have been subsequently eroded. the size of the glaciers and the presence of an alpine ice field are still debated. in the distal sector, the po plain was filled by outwash streams (muttoni et al., 2003; scardia et al., 2006; garzanti et al., 2011). the ivrea (san michele-borgo and granero units in carraro et al., 1991; mongrando unit in gianotti et al., 2015) (fig. 4 and fig. 5c) and garda (ciliverghe hill and the chiese river sequence, fig. 5d) morainic amphitheaters hosted wide glacier piedmont lobes and it is likely that also the verbano (morazzone unit, but possibly also the immacolata and vivirolo formations) and the oglio (valenzano unit) glacier lobes spread out from the valley (bini, 2004a). with respect to the adda glacier, paleomagnetic analysis of the brugora glaciolacustrine sequence, formerly attributed to the bozzente unit (bini et al., 2014), provided reverse magnetization (fig. 6). actually, the deposits of the bozzente unit, as properly defined in terms of weathering profile and geomorphologic position (zuccoli, 2000; bini et al., 2014) bear brunhes chron normal magnetization (scardia et al., 2010), thus the brugora site must be ascribed to the late matuyama glaciations, possibly correlative of the san salvatore till (zuccoli, 2000). remnants of alpine intermontane basins, such as ecoteaux, leffe, and pianico, also recorded vegetational changes and glacigenic deposits related to the late matuyama glaciation (pugin et al., 1993; muttoni et al., 2007; scardia & muttoni, 2009). according to häuselmann et al. (2007), intensive glacial overdeepening of alpine valleys began during the late matuyama advance (i.e. aare valley). since the late matuyama, the progressive development of even more extensive glaciations has promoted deep valley incision and overdeepening in many sectors of the alps. however, it is likely that the late matuyama ice domes had smaller volumes than in the middle to late pleistocene glaciations, considering even if the extension of the piedmont lobes looks quite similar. it is remarkable that both the french western alps and the eastern alps are apparently missing remnants of matuyama glacial units (ivy-ochs et al., 2022 and references therein). 5. early-middle brunhes glaciations (mis188) marine isotope stages 16 and 12 are related to the greatest extents reached by boreal ice sheets (batchelor et al., 2019) as recorded by the prominent spikes of δ18o (lisiecki & raymo, 2005, bell et al., 2014; farmer et al., 2019). it is likely that also in the alps these cold phases 133 fig. 5 a) frontal moraine of the bornasco unit (middle pleistocene) in the ivrea end moraine system (site 2 in fig. 1); b) weathered lodgment till of the zubiena unit (middle pleistocene) in the ivrea end moraine system (site 2 in fig. 1); c) lodgment till and glaciolacustrine deposits of the mongrando unit (early pleistocene) in the ivrea end moraine system (site 2 in fig. 1); d) weathered fluvioglacial deposits (middle pleistocene) of ciliverghe laying on early pleistocene fluvial and glacial units in the garda end moraine system (site 7 in fig. 1). the early and middle pleistocene glaciations in the alps tocene was a period of intense incision and valley overdeepening after deposition of the deckenschotter units. in many foreland valleys of the swiss sector the bedrock floor is hundreds of meters beneath the present surface topography (jordan, 2010; preusser et al., 2010). palynological and luminescence data suggest that aggradation phases and filling of the overdeepened valleys began no later than 450 ka (mis 12; preusser et al., 2010; reitner et al., 2010; gegg et al., 2023; schwenk et al., 2022), possibly related to erosion-driven flexural uplift of the alps (scardia et al., 2012). recent studies ascribed the overdeepening in the bern area/aare valley to mis 12 (gegg et al., 2020; schwenk et al., 2022). recently, dieleman et al. (2022) studied the till layer (fig. 3d), which is exposed in a gravel pit at möhlin (canton of basel) and attributed it to the möhlin glaciation. the cosmogenic nuclide analysis in the clasts embedded in this till layer indicated a deposition age of 0.5 ±0.1 ma. in the austrian foreland, paleomagnetic constraints in loess successions (scholger & terhorst, 2013) and geological considerations (van husen & reitner, 2011a, b) were used to tentatively correlate the günz and mindel glaciations with the severe global climatic deteriorations of mis 16 and mis 12. in the austrian part, the preserved morphological and sedimentary record indicates the mindel glaciation as the largest one. günz end 134 fig. 6 the brugora site from the brianza lobe of adda glacier (site 5 in fig. 1). a) lodgement till passing upward to b) glaciolacutrine finegrained, laminated deposits with drop-stones. c) orthogonal projection of thermal demagnetization data of representative samples from the brugora site. d) equal-area projection of the characteristic component vectors determined for the brugora glaciolacustrine deposits. open circles indicate negative inclinations and plot onto the upper hemisphere. monegato g. et al. “external moraine complex” and ascribed to cold phases of the middle pleistocene (mandier, 1982). 6. the penultimate glaciation (mis6) the penultimate glaciation occurred at the end of the middle pleistocene and it is considered as the largest in term of ice sheets volume (batchelor et al., 2019). deposits related to this cold phase in the alps were dated with luminescence methods on glaciofluvial and glaciolacustrine exposed successions (preusser & schlüchter, 2004; bickel et al., 2015a, b; salcher et al., 2015; schielein et al., 2015; rades et al., 2018). in the swiss-german sector, detailed sedimentological work and luminescence dating have been done also on cores taken from the overdeepened valleys (dehnert et al., 2012; lowick et al., 2015; buechi et al., 2018), obtaining ages from mis 6 or even somewhat earlier (gegg et al., 2022). these studies depicted several phases of glacier advance and withdrawal, suggesting complex dynamics of the rhine glacier system from the end of mis 7 to the waning stages of mis 6. in many end-moraine systems of the alps, glacial deposits and landforms related to the penultimate glacial cycle are often close to those of the lgm, suggesting a comparable extension. they are distinguishable because their soils are much more developed, disallowing their attribution to the later pleistocene (e.g., venzo, 1977; castiglioni, 2004; zanferrari et al., 2008; buoncristiani & campy, 2011; doppler et al., 2011; preusser et al., 2011; ellwanger et al., 2011; van husen & reitner, 2011a; gianotti et al., 2015; fioraso et al., 2021). in the french western alps it is considered the “external moraine complex”, tentatively associated to the riss (buoncristiani & campy, 2011). in the eastern part of the austrian alps an exceptionally large mis 6 glaciation with terminal moraines up to 40 km downvalley of their lgm counterparts, like in the enns valley (eastern alps), did occur (fig. 7). such findings in narrow and gently sloping valleys can be explained by icedynamical reasons, such as ice congestions resulting in a disproportionate increase of accumulation areas of the salzach and enns (van husen, 2000), promoted by the moderate additional lowering of the ela of around 100 m (penck & brückner, 1901-1909). in the julian alps, ice-marginal and glacial deposits were dated to mis 6 glaciation in the soča valley (bavec et al., 2004; jamšek rupnik et al., 2022). in the southern side of the alps, mis 6 moraines are normally very close or partially buried by lgm terminal moraines. this situation can be detected in many morainic amphitheaters (cremaschi, 1987; rossato et al., 2013; gianotti et al., 2015; fioraso et al., 2021; kamleitner et al., 2022). in the verbano and lario amphitheatres, the besnate allogroup, formerly ascribed to the middle-late pleistocene (bini, 1997), has been dated to the lgm (kamleitner et al., 2022), suggesting that golasecca and binago units (tab.1) can be tentatively ascribed to mis 6. in the tagliamento sector the mis 6 moraines and glaciofluvial units were traced from the end moraine system to the coastline (zanferrari et al., 2008; pini et al., 2009; fontana et al., 2010). moraines are only preserved where the mindel glaciers had a slightly different advance direction. an outstanding middle pleistocene succession at kremsmünster in the krems valley (19 in fig. 1) is ascribed to glaciofluvial aggradation (kohl, 2000); it is stratigraphically confined between günz and mindel tills and glaciofluvial deposits, suggesting a cold phase of minor landscape modification between mis 16 and mis 12. this stratigraphic architecture still needs chronological constraints for a better assessment. in many morainic amphitheaters of the southern alpine sector the early-middle brunhes glaciations are distinguished in the stratigraphic architecture by the means of bounding surfaces marked by buried soils (paleosols), pedostratigraphy based on surface soils (bini et al., 2004a; gianotti et al., 2015; fioraso et al., 2021), occurrence of loess (venzo, 1965) or interbedded organic layers containing warm flora (pini et al., 2009; gianotti et al., 2008; 2015). in detail, in the eastern sector of the ivrea morainic amphitheatre, seven units (bornasco, montino, zubiena, parogno, torrazzo, magnano and external serra) are tentatively ascribed to the middle pleistocene glaciations (fig. 4), apart from the possibility of a late pleistocene, pre-lgm age for the external serra unit (gianotti et al., 2008; 2015). the mongrando (mis 22-20, with reversed polarity) and bornasco (mis 18) units are separated by the bosa paleosol (mis 19 interglacial). the bornasco (mis 18e) (fig. 5a) and montino (mis 18a) sub-units are separated by the sorgente sulfurea peaty layer with cool-climate pollens (mis18b-d interstadial) and so they can be correlated to the two peaks of the mis 18 glaciation, montino sub-unit (mis 18) and zubiena unit (mis 16) (fig. 5b) by the cascina comunità palaeosol (mis 17 interglacial), the parogno (mis 12) and torrazzo units (mis 10) by the cascina gianetto palustrine gyttja with warm-climate pollens (mis 11.3 interglacial, gianotti et al., 2015). other stratigraphic boundaries (zubiena-parogno and torrazzo-magnano) were identified by pedostratigraphy; pedogroup a (mongrando to zubiena units) shows hue 2.5yr, pedogroup b (parogno and torrazzo units) hue 5yr, and pedogroup c (magnano, external serra and ivrea synthems) hue 7.5yr. within the less ancient pedogroup, the magnano unit (mis 8 or, more likely, mis 6) is distinguishable from the external serra unit (mis 6, mis 4 or mis 3, based on pre-lgm exposure ages of erratic boulders) by soils with a thicker b horizon (> 2 m) and a higher degree of weathering of the clasts. in others morainic amphitheaters of the lombardy piedmont plain several middle pleistocene landform remnants (moraines and kame terraces) were distinguished through the occurrence of paleosols, loess cover and peat layers (bini et al., 2004a, 2014). each moraine system has its own stratigraphic subdivision (tab. 1), even if geochronological constraints are poor. in the verbano area thick aeolian deposition ascribed to middle pleistocene cold phases have been distinguished by means of paleosols (terhorst & ottner, 2003; terhorst et al., 2012; terhorst, 2013). at east of the garda system, glacial deposits related to early-middle brunhes are lacking or debated (zanferrari et al., 2013). the same lack of information occurs in the french side of the western alps, where glaciofluvial units were detected outside the 135 the early and middle pleistocene glaciations in the alps 136 fig. 7 glacier extent during the würmian (mis 2) and rissian (mis 6) in the enns valley and environs and in the steyr and ybbs valleys (mod. after van husen, 2011a). fig. 8 correlation sketch of the glacial/glaciofluvial units recognized for each sector of the alps; numbers indicate the sites of fig. 1 and tab. 1. black triangles indicate glacial unit and black dots glaciofluvial unit. green color points to available chronology; yellow color points to available reverse polarity. δ18o curve from lisiecki & raymo (2005). monegato g. et al. tary analyses with paleoclimatic proxies (i.e. pollen data) that indicate which part of the succession can be related to cold stages. for early pleistocene glaciations this means multidisciplinary investigation on deep cores of the depocenter areas (i.e., po plain, rhine graben, and vienna basin) coupled with investigation in major valleys (anselmetti et al., 2022). 7.2. extent of glaciations? as depicted by the distribution of the preserved record, we can argue how glacier expansions developed during each cold stage. the reconstruction of the paleoclimate during the lgm showed how the alps are sensitive to small shifts in atmospheric that conditioned the ela lowering circulation (luetscher et al., 2015; monegato et al., 2017; gribenski et al., 2021). moreover, the asymmetry of the alpine range in terms of distribution of high elevation areas would contribute to differentiate the major accumulation sectors according to their location with respect to the storm tracks feeding the glaciers. as remarked, for example, by the large extent of the mis 6 glaciation in the austrian sector (ybbs and enns in tab. 1 and fig. 7), we suppose that slightly lower ela can cause the development of a much larger glacier system. in this perspective, the concept of a most extensive glaciation can be applied only in specific sectors of the range and must not encompass the whole alps. the fact that mis 12, mis 6 or lgm frontal moraines occupy the outermost position in eastern and southeastern alps more frequently than in the southwestern or the northern alps points to different distribution of precipitation during each cold phase, determining the size of the glaciers and piedmont lobes. 7.3. which were the major glaciations? dissimilar distribution of the glacial units in the circumalpine area points to a reduced number of “major” glaciations and the most extensive glaciation concept 7. discussion 7.1. how many glaciations? located at mid latitude between the mediterranean sea and continental europe, the alps are the highest mountain range of this continent and are very sensitive to climate changes. in this way, they can have hosted mountain glaciers since the onset of the pleistocene glaciations. the available data of glacigenic deposits older than the late pleistocene are numerous, also thanks to more than 150 years of research, and can provide insights on how the pleistocene cold stages affected the alps and how many times. according to the available data from the area with the more detailed stratigraphic successions (fig. 8), a minimum of 13 different glacier advances of early to middle pleistocene age are recognized in the swiss foreland (preusser et al., 2011; schlüchter et al., 2020), about nine to ten in the ivrea and verbano sectors (bini, 1997; gianotti et al., 2015; zuccoli, 2000), but apparently only four in the lake garda area (cremaschi, 1987) and two in the tagliamento system (zanferrari et al., 2013). these events should represent locally just the major glacier expansions onto the foreland (fig. 9) and other cold stages (e.g. mis 14 and mis 8 stages, according to their weaker isotopic signal in the mis curve) should have seen glaciers expanded but remaining within the alpine valleys. moreover, the occurrence of multiple phases of glacier advance and withdrawal within the same cold stage (i.e., dehnert et al., 2012; lowick et al., 2015) has to be carefully considered for a correct counting of glaciation in a single sector. glaciofluvial input in the foreland is also an important tracer of sediment production and delivery during cold stages (scardia et al., 2006, 2012; garzanti et al., 2011; preusser et al., 2021; marcolla et al., 2021). however, to distinguish them in the lower-middle pleistocene successions implies the coupling of the sedimen 137 fig. 9 map of the alps with the sectors of tab. 1 colored for number of recorded glaciation: blue (1-2), purple (3-4), orange (5-6), red (>6). the early and middle pleistocene glaciations in the alps 138 g la ci a te d b as in u n it a g e k e y re fe re n ce s a tt ri b u ti o n d at es o th er c o n st ra in ts 1 s u s a v a lle y (r iv o li /a vi g li an a) c re st a g ra nd e m is 6 th ic k pa la eo so l o n to p (1 07. 5y r h ue c ol or in de x) , s tra tig ra ph ic co rre la tio n fi or as o et a l., 2 02 1 t ru c c a rle vè m id d le p le is to ce ne th ic k pa la eo so l o n to p (5 yr h ue c ol or in de x) t ru c m on sa gn a sc o m id d le p le is to ce ne th ic k pa la eo so l o n to p (7 .5 -5 yr h ue c ol or in de x) t ru c b a nd ie ra m id d le p le is to ce ne th ic k pa la eo so l o n to p (5 yr h ue c ol or in de x) s a n ga no e a rly ? -m id d le p le is to ce n e 2 a o s ta v a ll e y (i vr e a ) e xt e rn a l s e rr a m is 6 ( m is 4 o r m is 3 ) c o sm o ge n ic a ge s 10 b e : 35 .0 ± 3 .9 a n d 3 0. 8 ±3 .5 k a p ed os tra tig ra ph y g ia no tti e t a l., 2 00 8, 2 01 5 m a gn a n o m is 8 pe do st ra tig ra ph y (7 .5 yr h ue c ol or in de x) , s tra tig ra ph ic c or re la tio n t o rr a zz o m is 1 0 pe do st ra tig ra ph y (5 yr h ue c ol or in de x) po lle n da ta fr om a b as al p al us tri ne la ye r ( m is 1 1 in te rg la ci al p a ro gn o m is 1 2 po lle n da ta fr om a b as al p ea t l ay er , 5 yr h ue c ol or in de x z u b ie na m is 1 6 pa le os ol (2 .5 yr h ue c ol or in de x) , s tra tig ra ph ic c or re la tio n m o n tin o /b o rn a sc o m is 1 8? po lle n da ta fr om a p ea t l ay er m o n gr a n d o m is 2 02 2 re ve rs e po la rit y, p al ae os ol , p ed os tra tig ra ph y (1 0 r -2 .5 yr h ue c ol or in de x) c ar ra ro e t a l., 1 99 1; g ia no tti e t a l., 2 01 5 3 o s s o la v al le y (o rt a ) s o ris o m id d le p le is to ce ne no rm al p ol ar ity pi an a et a l., 2 01 7 g a rg a llo m id d le p le is to ce ne th ic k pa la eo so l o n to p 4 o ss o la a n d t ic in o v a ll e ys (v er b an o ) g o la se cc a m id d le p le is to ce ne pa le os ol (1 07. 5y r h ue c ol or in de x) , s tra tig ra ph ic c or re la tio n zu cc ol i, 20 00 ; b in i e t a l., 2 01 4 a lb iz za te m id d le p le is to ce ne pa le os ol (7 .5 yr h ue c ol or in de x) , s tra tig ra ph ic c or re la tio n m o ra zz o n e g ro up ( 3 u n its ) e a rly p le is to ce n e? pa le os ol (5 -7 .5 yr h ue c ol or in de x) , s tra tig ra ph ic c or re la tio n c a st ro n no e a rly p le is to ce n e? th ic k pa la eo so l o n to p an d st ra tig ra ph ic c or re la tio n im m a co la ta e a rly p le is to ce n e? st ra tig ra ph ic c or re la tio n v iv iro lo e a rly p le is to ce n e? st ra tig ra ph ic c or re la tio n 5 a d d a v a ll e y (l ar io a n d m e n d ri si o ) b in a go m id d le p le is to ce ne pa le os ol (1 07. 5y r h ue c ol or in de x) , s tra tig ra ph ic c or re la tio n zu cc ol i, 20 00 ; bi ni e t a l., 2 01 4 s p e co la m id d le p le is to ce ne pa le os ol (5 -7 .5 yr h ue c ol or in de x) , s tra tig ra ph ic c or re la tio n b o zz e n te g ro u p (2 u n its ) m id d le p le is to ce ne pa le os ol (1 02. 5y r h ue c ol or in de x) , s tra tig ra ph ic c or re la tio n c re m as ch i e t a l., 1 98 5; z uc co li, 2 00 0 s a n s a lv a to re m is 2 02 2 re ve rs e po la rit y sc ar di a et a l., 2 01 0 c a sa n o va l a n za g ro up e a rly p le is to ce n e? st ra tig ra ph ic c or re la tio n bi ni e t a l., 2 01 4 6 c am o n ic a v al le y (s eb in o ) m o n te ro to nd o m id d le p le is to ce ne pa le os ol (1 07. 5y r h ue c ol or in de x) , s tra tig ra ph ic c or re la tio n c as si ni s et a l., 2 01 1 m o n te p ia ne m id d le p le is to ce ne pa le os ol (5 -7 .5 yr h ue c ol or in de x) , s tra tig ra ph ic c or re la tio n f a n te co lo m id d le p le is to ce ne pa le os ol (5 -7 .5 yr h ue c ol or in de x) , s tra tig ra ph ic c or re la tio n c a m ig n o ne m id d le p le is to ce ne pa le os ol (1 05y r h ue c ol or in de x) , s tra tig ra ph ic c or re la tio n p a d e rn o d i f ra n ci a co rt a m id d le p le is to ce ne pa le os ol (1 05y r h ue c ol or in de x) , s tra tig ra ph ic c or re la tio n v a le n za n o e a rly p le is to ce n e? pa le os ol (1 02. 5y r h ue c ol or in de x) , s ca tte re d bo ul de rs 7 a d ig e /s a rc a va ll e ys ( g a rd a ) s e d en a /a lb a re m id d le p le is to ce ne th ic k pa la eo so l o n to p an d st ra tig ra ph ic c or re la tio n c re m as ch i, 19 87 , ac co rs i e t a l., 1 99 0 c a rp e n ed o lo m id d le p le is to ce ne c a rp e n ed o lo -m o n tic h ia ri m id d le p le is to ce ne c ili ve rg h e m is 2 02 2 re ve rs e po la rit y c re m as ch i, 19 87 ; b ar on i & c re m as ch i, 19 87 ; sc ar di a et a l., 2 01 5 7a a d ig e v a ll e y (r iv o li v er o n es e) m o n te c riv e lli n o m id d le p le is to ce ne ac co rs i e t a l., 1 99 0 c a p rin o m id d le p le is to ce ne p e si n a e a rly p le is to ce n e? 8 a s ti c o v a ll e y (c o g o llo ) s e gh e tta m is 6 po lle n da ta r os sa to e t a l., 2 01 3 p rà d e o ch i m id d le p le is to ce ne c uc at o, 2 00 1 9 p ia ve v a ll e y r is s gl a ci a l m id d le p le is to ce ne th ic k pa la eo so l o n to p an d st ra tig ra ph ic c or re la tio n ve nz o, 1 97 7 10 t ag lia m e n to p la in o m is 6 po lle n da ta a nd s tra tig ra ph ic c or re la tio n za nf er ra ri et a l., 2 00 8; l ow ic k et a l., 2 01 0 l e d ra n ia m id d le p le is to ce ne w ea th er ed g la ci al re m na nt s on ly in th e lo w er v al le y m on eg at o an d st ef an i, 20 11 ; za nf er ra ri et a l., 2 01 3 11 s o č a/ is o n zo r a vn i l a z/ m o d re jc e m is 6 ir s l d a te s in b o ve c: 1 5 4 .7 ± 2 2. 8 k a a n d u /t h d at e s: 1 52 .7 k a . o s l d a te s in m o d re jc e : 16 5 ± 6 5 ka a n d 1 6 9 ±2 1 ka ba ve c et a l., 2 00 4; b av ec & v er bi c, 2 01 1 ja m še k r up ni k et a l., 2 02 2 12 s a va b le dr ad ov lji ca m is 6 ir s l da te s: 1 5 6 ±1 8 ka ba ve c & ve rb ic , 2 01 1 u d in b o rš t e a rly p le st o ce ne c o sm o ge n ic a ge : 1. 9 ± 0 .2 m a m ih ev c et a l., 2 01 5 13 d ra u r is s gl a ci a l m is 6 bo be k, 1 95 9; v an h us en , 1 98 9 monegato g. et al. t ab . 1 a 139 g la ci a te d b as in u n it a g e k e y re fe re n ce s a tt ri b u ti o n d at es o th er c o n st ra in ts 14 m u r r is s gl a ci a l m is 6 sp re itz er , 1 96 1 15 e rl au f r is s gl a ci a l m is 6 m os er & s ch na be l, 20 19 16 l am in g r is s gl a ci a l m is 6 br yd a et a l. 20 13 17 y b b s r is s gl a ci a l m is 6 l u m in e sc en ce d a te s: 1 5 0 ±1 4 k a ( p ir ir 22 5 ) to 1 2 9 ±1 4 k a ( o s l ) n ag l, 19 70 ; b ic ke l e t a l. 20 15 a 18 e n n s r is s gl a ci a l m is 6 eg ge r & v an h us en , 2 01 1 19 s te yr -k re m s r is s gl a ci a l m is 6 va n h us en , 1 97 5, 2 00 0; k oh l, 19 99 m in d e l g la ci a l m is 1 2 ko hl , 2 00 0 va n h us en , 2 00 0; g ü n z gl a ci a l m is 1 6 20 a lm r is s gl a ci a l m is 6 eg ge r, 20 07 a 21 t ra u n r is s gl a ci a l m is 6 po lle n da ta eg ge r, 20 07 a, b ; va n h us en & e gg er , 2 01 4 m in d e l g la ci a l m is 1 2 g ü n z gl a ci a l m is 1 6 ko hl 2 00 0; e gg er , 2 00 7a 22 s a lz ac h r is s gl a ci a l m is 6 o s l d a te s: 1 9 3 ±3 0 k a 1 8 8 ±2 7 k a w ei nb er ge r, 19 55 ; r up p et a l., 2 01 1 sa lc he r e t a l., 2 01 5 m in d e l g la ci a l m is 1 2 w ei nb er ge r, 19 55 ; v an h us en , 2 00 0; d op pl er e t al ., 20 11 g ü n z gl a ci a l m is 1 6 23 in n -c h ie m se e r is s gl a ci a l m is 6 d op pl er e t a l., 2 01 1 m in d e l g la ci a l m is 1 2 24 is a rl o is a c h r is s gl a ci a l m is 6 d op pl er e t a l., 2 01 1 p a rs b e rg s w p u ch h e im m id d le p le is to ce ne 25 l e c h -w e rt ac h l e n ge nf e ld -l u d w ig sb e rg m is 6 d op pl er e t a l., 2 01 1 26 il le r r is s gl a ci a l m is 6 d op pl er e t a l., 2 01 1 h o lz h e u e r h ö h e b ra nd h o lz m a n n eb e rg m id d le p le is to ce ne 27 r h e in d o p p e lw a ll r is s m is 6 ir s l d a te s: 1 4 9 ± 1 5 to 1 7 9 ±1 7 ka r ad es e t a l., 2 01 8 l a up e rt sh a u se n m id d le p le is to ce ne sc hr ei ne r, 19 97 ; d op pl er e t a l., 2 01 1 h ei lig en be rg e ar ly ? -m id dl e p le is to ce n e s ch ie ne rb e rg d e ck e n sc h o tte r e a rly p le is to ce n e g ra f, 20 09 a c h ro o b a ch d e ck e n sc ho tt e r e a rly p le is to ce n e c o sm o ge n ic a ge : 1. 8 ± 0 .1 m a g ra f, 20 09 a; d ie le m an e t a l., 2 02 2 28 r eu ss /l in th r h e in /r h e in b e rin ge n g la ci a tio n m is 6 ir s l d a te s (~ 1 8 5 k a ) a t k le tt ga u o s l da te s fr om 1 5 9± 8 ka t o 20 5± 12 a t r in ik er fe ld g ra f, 20 09 b; k el le r & k ra ys s, 2 01 1, p re us se r e t al ., 20 11 ; d eh ne rt et a l., 2 01 0, 2 01 2; l ow ic k et al ., 20 15 ; b ue ch i e t a l., 2 01 7; s ch lü ch te r e t a l., 20 20 ; d ie le m an e t a l., 2 02 2; g eg g et a l., 2 02 2 h a ge n h o lz g la ci a tio n m id d le p le is to ce ne h a b sb u rg g la ci a tio n m id d le p le is to ce ne m ö h lin g la ci a tio n m id d le p le is to ce ne c o sm o ge n ic a ge : 0. 5 ± 0 .1 m a r h e in / l in th -r h ei n ir ch e l d e ck en sc h ot te r e a rly p le is to ce n e c o sm o ge n ic a ge s: 2 .6 0 .9 m a c la ud e et a l., 2 01 9; k nu ds en e t a l., 2 02 0; d ie le m an e t a l., 2 02 2a m am m a l f o ss ils : 2 .6 1 .8 m a (m n 1 7 ) bo llig er e t a l., 1 99 6 r e u s s / l in th -r h ei n ib e rig d e ck e n sc ho tte r e a rly p le is to ce n e c o sm o ge n ic a ge : 1. 3 0 .7 m a g ris ch ot t e t a l., 2 02 0; kn ud se n et a l., 2 02 0 t ro m sb e rg d e ck en sc ho tt e r e a rly p le is to ce n e c o sm o ge n ic a ge : 1. 3 0 .9 m a f e u si d e ck en sc h ot te r e a rly p le is to ce n e c o sm o ge n ic a ge : 1. 3 0 .9 m a s ig lis to rf d e ck en sc ho tte r e a rly p le is to ce n e c o sm o ge n ic a ge : 1. 5 ± 0 .2 m a ak ça r e t a l., 2 01 7 u e tli b e rg /a lb is d e ck e ns ch o tte r e a rly p le is to ce n e re ve rs ed p ol ar ity g ra f, 20 19 s ta d le rb e rg d e ck e n sc h o tte r e a rly p le is to ce n e c o sm o ge n ic a ge : 2. 4 + 2. 3 -1 .2 m a c la ud e et a l., 2 01 7; 2 01 9 29 a a re t ha lg u t m id d le p le is to ce ne sc hl üc ht er , 1 98 9; pr eu ss er & s ch lü ch te r, 20 04 r h o n ev al ai s ju ra m o un ta in s, s ca tte re d a lp in e b o u ld e rs m id d le p le is to ce ne c o sm o ge n ic a ge s: > 15 0 k a g ra f e t a l., 2 01 5 m e ik irc h m id d le p le is to ce ne , m is 8 sc hl üc ht er , 1 98 9; p re us se r e t a l., 2 00 5 30 is er er h o n e b a ro lle s m id d le p le is to ce ne m an di er , 1 98 2 o zo n m id d le p le is to ce ne t e rn a y m id d le p le is to ce ne l o u ze -m o n ta ill o ud m id d le p le is to ce ne 31 d u ra n c e s is te ro n ( r is s) m id d le p le is to ce ne g ab er t, 19 84 ta b. 1 ( a a nd b ) f ra m ew or k of e ar ly -m id dl e p le is to ce ne s tra tig ra ph ic u ni ts in th e a lp s re la te d to g la ci at io ns . t he re gi on s ar e la be le d an d re fe rr ed to f ig . 1 fo r lo ca tio n. the early and middle pleistocene glaciations in the alps t ab . 1 b should be applied with local significance, not being suitable for the whole alpine range. as the lgm can be considered a major one, the paleoclimatic setting that produced such an ice extent can be assumed also for the other large glacier extents in the alps. nevertheless, favorable microclimate conditions can promote local glacier advances in periods not necessarily in tune with the cold stages (gribenski et al., 2021). considering the ivrea-verbano area, available data show that six glacier advances took place in the middle pleistocene (bini, 2012; gianotti et al., 2015, tab. 1) as related to the stratigraphy of the foreland (scardia et al., 2012; garzanti et al., 2011), almost every cold stage could have here a preserved sedimentary signature. this can be related to the high elevation accumulation area (and in addition, located very close to the piedmont area in the case of the ivrea amphitheatre), which is able to host a large valley glacier and a powerful piedmont lobe when climate became cold enough to force a lowering of the ela. on the northern side, the other major ice domes (rhine and engadine; florineth & schlüchter, 2000; kelly et al., 2004) promoted four major glacier advances in the swiss foreland during the middle pleistocene (preusser et al., 2011); in this framework, the beringen glaciation was dated to mis 6 (lowick et al., 2015; buechi et al., 2017) and the möhlin glaciation to mis 12 (gaar & preusser, 2017; preusser et al., 2021; dieleman et al., 2022). these sectors have high accumulation areas fed both by westerly and southerly circulation and can develop large glaciers in both configurations. on the other side, in the northeastern alps the larger extent is related to the riss with overflow of enns glacier into weakly glaciated catchments (van husen, 2000); this phase is ascribed to mis 6 (van husen, 2000; van husen & reitner, 2011a). same processes are likely for the mindel (mis 12) glaciation, where preserved moraines and related glacigenic deposits in austria and southeastern bavaria are even more distal from the alpine front. in the southeastern side (piave, tagliamento and soča catchments), all the morainic amphitheaters show mis 6 deposits slightly outside the lgm (venzo, 1977; monegato et al., 2010; rossato et al., 2013). no more external glacial deposits have been observed, thus indicating that mis 6 bore the largest configuration in the sector. the longitudinal extremes (french side and eastern austrian sector) show only one middle pleistocene glacial unit (tab. 1 and fig. 9) larger than lgm. considering that in the western alps glacier growth is favored by westerly circulation, while the eastern alps are dominantly fed by southerly storm tracks, these units can testify to different cold stages of the middle pleistocene. the garda and adda systems, which are fed by the largest mountain catchments of the southern side of the alps, show three major units in the middle pleistocene, besides the lgm and the late matuyama (cremaschi, 1987; bini, 2012). considering their size, these systems need mostly southerly circulation for the expansion of the glacier network and formation of a piedmont lobe. in this perspective, apparently only three times in the middle pleistocene was the circulation comparable to the lgm, possibly in phase with the large extents of the boreal ice sheets (batchelor et al., 2019) and especially to the laurentide ice sheet, whose topography forced the polar front to the mid latitudes and the storm track into the mediterranean (beghin et al., 2015; del gobbo et al., 2022). 8. conclusions the nearly 200 years of research on alpine glaciations has shown that the alps hosted extensive glaciations in correspondence of several pleistocene cold stages and likely smaller valley glaciers during the minor climate deteriorations. thanks to the stratigraphic and geochronological data accumulated in the last decades, new insights have been provided for depicting the early pleistocene glaciations, whose extent was previously hypothetical, but now, especially in the northern foreland, their record is continuously updated. the onset of glaciations since the late matuyama (mis 22-20) is better recognized in many end moraine systems in the southern side of the alps and correlating with foreland core stratigraphy. the updated chronology of the middle pleistocene phases indicates it is likely that every sector has had its own most extensive glaciation in a different time span. the dissimilar architecture of the glacigenic units at the outlet of the major alpine catchments points to a different behavior of the glaciers depending on global paleoclimate configuration, which was likely dissimilar from one stage to the other. moreover, in the large accumulation areas of the central alps (adige, adda and inn) the development of an extensive interconnected glacier network with associated piedmont lobes required abundant snow supply also from the southerly circulation, which was promoted by the large extent of the laurentide ice sheet. in the higher accumulation areas (valais, dora baltea, rhine-reuss and ticino-toce) a larger number of glacial units was recorded probably because a small ela lowering in these catchments could lead to glacier advance. finally, the alps remain the most studied mountain range for reconstructing extents of quaternary glaciers and testing new methods and models. the long lasting studies are a treasure to preserve and a motivation for even better depicting the climatic and geomorphological evolution of the highest mountain environment of central europe. acknowledgements we want to thank the reviewers g. orombelli and l. gegg, whose suggestions greatly improved our manuscript. we also thank a. fontana (a.e.) for his comments. references agassiz l. (1840) études sur les glaciers. gent et gassman, neuchâtel. pp. 356. akçar n., ivy-ochs s., alfimov v., claude a., graf h.r., dehnert a., kubik p.w., rahn m., kuhlemann j., schlüchter c. (2014) the first major incision of the swiss deckenschotter landscape. swiss journal of geosciences, 107, 337347. 140 monegato g. et al. linked to the penultimate glaciation in the eastern alps. quaternary international, 357, 110-124. bickel l., lüthgens c., lomax j., fiebig m. (2015b) the timing of the penultimate glaciation in the northern alpine foreland: new insights from luminescence dating. proceedings of the geologists' association, 126(4-5), 536-550. billard a., derbyshire e. (1985) pleistocene stratigraphy and morphogenesis of la dombes: an alternative hypothesis. bull. ass. française pour l’etude du quaternaire. 22, 85-96. billard a., orombelli g. (1986) quaternary glaciations in the french and italian piedmonts of the alps. quaternary science reviews, 5, 407-411. bini a. (1997) stratigraphy, chronology and paleogeography of quaternary deposits of the area between the ticino and olona rivers (italyswitzerland). geologia insubrica, 2, 21-46. bini a. (2012) i ghiacciai del passato. in: bonardi l., rovelli e., scotti r., toffaletti a., urso m., villa f. (eds.), i ghiacciai della lombardia. hoepli, milano, 11-19. bini a., zuccoli l., bussolini c., corbari d., da rold o., ferliga c., rossi s., viviani c. (2004a) glacial history of the southern side of the central alps, italy, in: elhers j., gibbard p.l. (eds.), quaternary glaciations-extent and chronology-part i: europe. elsevier, 195-200. bini a., borsato a., carraro f., carton a., corbari d., cucato m., monegato g., pellegrini g.b. (2004b) definitions of terminologies used in the mapping of quaternary deposits in the alpine area. il quaternario italian journal of quaternary science, 17 (1), 75-82. bini a., sciunnach d., bersezio r., scardia g., tomasi f. (2014) note illustrative della carta geologica d’italia alla scala 1:50.000. foglio 096-seregno. ispra-regione lombardia, pp. 192. bini a., baio a., pavia f. (2015) analisi di una sezione geologica tracciata tra adda e mella, al margine tra alta e bassa pianura. geologia insubrica, 11, 316. blaas j. (1884) die zeichen der eiszeit in tirol. tiroler. schulfreund, innsbruck, nr. 7-9. bobek h. (1959) der eisrückzug im östlichen klagenfurter becken. mitteilungen der österreichischen geographischen gesellschaft; 101 (1959), 3-36. bolliger t., fejfar o., graf h.r. (1996) vorläufige mitteilung über funde von pliozänen kleinsäugern aus den höheren deckenschottern des irchels (kt. zürich). eclogae geol. helv. 89 (3), 1043-1048. bourdier f. (1963) le bassin du rhône au quaternaire. géologie et préhistoire. editions du centre national de la recherche scientifique, paris, pp. 294. bowen d.q. (1978) quaternary geology. a stratigraphic framework for multidisciplinary work, pergamon press, oxford, pp. 221. bruno l. (1877) i terreni costituenti l’anfiteatro allo sbocco della dora baltea. tipogragia f.l. curbis, ivrea, pp. 65. akçar n., ivy-ochs s., alfimov v., schlunegger f., claude a., reber r., christl m., vockenhuber c., dehnert a., rahn m., schlüchter c. (2017) isochron-burial dating of glaciofluvial deposits: first results from the swiss alps. earth earth surface processes and landforms, 42, 2414-2425. ambrosetti p., cigala fulgosi f., de giuli e., vialli v. (1980) mammiferi del pleistocene inferiore. in: i vertebrati fossili italiani. catalogo della mostra, verona, 217-226. anselmetti f.s., bavec m., crouzet c., fiebig m., gabriel g., preusser f., ravazzi c. and dove scientific team (2022) drilling overdeepened alpine valleys (icdp-dove): quantifying the age, extent, and environmental impact of alpine glaciations. sci. dril., 31, 51-70. bailey i., hole g.m., foster g.l., wilson p.a., storey c.d., trueman c.n., raymo m.e. (2013) an alternative suggestion for the pliocene onset of major northern hemisphere glaciation based on the geochemical provenance of north atlantic ocean ice-rafted debris. quaternary science reviews, 75, 181-194. balco g., rovey c.w. (2010) absolute chronology for major pleistocene advances of the laurentide ice sheet. geology, 38, 795-798. baroni c., cremaschi m. (1987) geologia e pedostratigrafia della collina di ciliverghe (brescia). annali museo civico storia naturale brescia, 23, 55-78. batchelor c.l., margold m., krapp m., murton d.k., dalton a.s., gibbard p.l., stokes c.r., murton j.b., manica a. (2019) the configuration of northern hemisphere ice sheets through the quaternary. nature communications, 10, 3713. doi: 10.1038/s41467-019-11601-2 bavec m., tulaczyk s.m., mahan s.a., stock g.m. (2004) late quaternary glaciation of the upper soča river region (southern julian alps, nw slovenia). sedimentary geology, 165, 165-183. bavec m., verbič t. (2011) glacial history of slovenia. in: ehlers j., gibbard p.l., hughes p.d. (eds.), quaternary glaciations extent and chronology a closer look, developments in quaternary sciences. elsevier, 385-392. beghin p., charbit s., dumas c., kageyama m., ritz c. (2015) how might the north american ice sheet influence the northwestern eurasian climate? climate of the past, 11, 1467-1490. bell d.b., jung s.j.a., kroon d., lourens l.j., hodell d.a. (2014) local and regional trends in pliopleistocene δ18 o records from benthic foraminifera. geochemistry geophysics geosystems, 15, 3304-3321. bibus e., bludau w., ellwanger d., fromm k., kösel m., schreiner a. (1996) on pre-würm glacial and interglacial deposits of the rhine glacier (south german alpine foreland, upper swabia, badenwürttemberg). in: turner ch. (ed.), the early middle pleistocene in europe, balkema, rotterdam, 195-204. bickel l., lüthgens c., lomax j., fiebig m. (2015a) luminescence dating of glaciofluvial deposits 141 the early and middle pleistocene glaciations in the alps bryda g., van husen d., kreuss o., koukal v., moser m., pavlik w., schönlaub h.-p., wagreich m. (2013) erläuterungen zur geologischen karte der republik österreich 1:50.000, blatt 101 eisenerz. geologische bundesanstalt, pp. 223. buechi m.w., lowick s.e., anselmetti f.s. (2017) luminescence dating of glaciolacustrine silt in overdeepened basin fills beyond the last interglacial. quaternary geochronology, 37, 55-67. buechi m.w., graf h.r., haldimann p., lowick s.e., anselmetti f.s. (2018) multiple quaternary erosion and infill cycles in overdeepened basins of the northern alpine foreland. swiss journal of geosciences, 111, 133-167. buoncristiani j.-f., campy m. (2011) quaternary glaciations in the french alps and jura. in: ehlers j., gibbard p.l., hughes p.d. (eds.), quaternary glaciations extent and chronology a closer look, developments in quaternary sciences. elsevier, 117-125. capeder g. (1904) sulla struttura dell’anfiteatro morenico di rivoli in rapporto alle diverse fasi glaciali. bollettino della società geologica italiana, 18, 309 -314. carraro f., malaroda r., piccoli g., sturani c., venzo s. (1970) carta geologica d’italia alla scala 1:100.000, f. 48 peschiera del garda. servizio geologico italiano. carraro f., lanza r., perotto a., zanella e. (1991) l’evoluzione morfologica del biellese occidentale durante il pliestocene inferiore e medio, in relazione all’inizio della costruzione dell’anfiteatro morenico d’ivrea. bollettino museo regionale di scienze naturali torino, 9(1), 99-117. carraro f. (1996) revisione del villafranchiano nell'area-tipo di villafranca d'asti. atti del convegno: "il significato del villafranchiano nella stratigrafia del plio-pleistocene" (peveragno (cn)villafranca d'asti (at), 20-24 giugno 1994). il quaternario italian journal of quaternary sciences, 9, 38-62. cassinis g., corbari d., falletti p., perotti c. (2011) note illustrative della carta geologica d’italia alla scala 1:50.000. foglio 099-iseo. ispra-regione lombardia, pp. 248. castiglioni g.b. (2004) quaternary glaciations in the eastern sector of the italian alps. in: elhers j., gibbard p.l. (eds.), quaternary glaciationsextent and chronology-part i: europe. elsevier, 209-215. chaline j., jerz h. (1984) arbeitsergebnisse der subkommission für europäische quartärstratigraphie. stratotypen des würm-glazials. eiszeitalter und gegenwart, 35, 185-206. champagnac j.d., molnar p., anderson r.s., sue c., delacou b. (2007) quaternary erosion-induced isostatic rebound in the western alps. geology 35, 195-198. charpentier j. de (1841) essai sur les glaciers et sur le terrain erratique du bassin du rhône. marc ducloux, lausanne, pp. 365. claude a., akçar n., ivy-ochs s., schlunegger f., kubik p.w., dehnert a., kuhlemann j., rahn m., schlüchter c. (2017) timing of early quaternary gravel accumulation in the swiss alpine foreland. geomorphology, 276, 71-85. claude a., akçar n., ivy-ochs s., schlunegger f., kubik p.w., christl m., vockenhuber c., kuhlemann j., rahn m., schlüchter c. (2019) changes in landscape evolution patterns in the northern swiss alpine foreland during the mid-pleistocene revolution. gsa bulletin, 131, 2056-2078. corselli c., gnaccolini m., orombelli g. (1985) depositi deltizi pliocenici allo sbocco della val brembana (prealpi bergamasche). rivista italiana di paleontologia e stratigrafia, 91, 117-132. cotton c.a. (1963) the question of high pleistocene shorelines. transactions of the royal society of new zealand geology, 2(5), 51-62. cremaschi m. (1987) paleosols and vetusols in the central po plain (northern italy). unicopli, milan. cremaschi m., orombelli g., salloway j.c. (1985) quaternary stratigraphy and soil development at the southern border of the central alps (italy): the bagaggera sequence. rivista italiana di paleontologia e stratigrafia 90, 565-603. de mortillet g. (1861) notes geologiques sur la savoie, pp. 72. dehnert a., preusser f., kramers j.d., akçar n., kubik p.w., reber r., schlüchter c. (2010) a multidating approach applied to proglacial sediments attributed to the most extensive glaciation of the swiss alps. boreas, 39, 620-632. dehnert a., lowick s., preusser f., anselmetti f., drescher-schneider r., graf h., heller f., horstmeyer h., kemna h., nowaczyk n., züger a., furrer h. (2012) evolution of an overdeepened trough in the northern alpine foreland at niederweningen, switzerland. quaternary science reviews, 34, 127-145. del gobbo c., colucci r.r., monegato g., žebre m., giorgi f. (2022) atmosphere-cryosphere interactions at 21 ka bp in the european alps. climate of the past discussions. doi: 10.5194/cp-2022-43 dieleman c., christl m., vockenhuber c., gautschi p., graf h.r., akçar n. (2022) age of the most extensive glaciation in the alps. geosciences, 12, 39. doi: 10.3390/geosciences12010039 doppler g., kroemer e., rögner k., wallner j., jerz h., grottenthaler w. (2011) quaternary stratigraphy of southern bavaria. quaternary science journal, 60(2/3), 329-365. du pasquier l. (1891) ueber die fluvioglacialen ablagerungen der nordschweiz. bern, eberl b. (1930) die eiszeitfolge im nördlichen alpenvorlande. ihr ablauf, ihre chronologie auf grund der aufnahmen im bereich des lechund illergletschers. augsburg, pp. 427. egger h. (2007a) erläuterungen zur geologischen karte der republik österreich 1:50.000, blatt 67 grünau i. almtal. geologische bundesanstalt, pp. 66. egger h. (2007b) erläuterungen zur geologischen 142 monegato g. et al. ennes en amont de sisteron, actes du colloque «signification dynamique et climatique des formations et terrasses fluviatiles quaternaires». bulletin de l’afeq, 1/2/3, 129-133. garzanti e., vezzoli g., andò s. (2011) paleogeographic and paleodrainage changes during pleistocene glaciations (po plain, northern italy). earth -science reviews, 105, 25-48. gastaldi b. (1865) sulla riescavazione dei bacini lacustri per opera degli antichi ghiacciai. memorie società italiana di scienze naturali, 1, 3-28. gegg l., buechi m. w., ebert a., deplazes g., madritsch h., anselmetti f.s. (2020) brecciation of glacially overridden palaeokarst (lower aare valley, northern switzerland): result of subglacial water-pressure peaks? boreas, 49, 813-827. doi: 10.1111/bor.12457 gegg l., preusser f. (2023) comparison of overdeepened structures in formerly glaciated areas of the northern alpine foreland and northern central europe. e&g quaternary science journal, 72, 23-36. doi: 10.5194/egqsj-72-23-2023 gianotti f., forno m.g., ivy-ochs s., kubik p.w. (2008) new chronological and stratigraphical data on the morainic amphitheatre of ivrea (piedmont, nw italy). quaternary international, 190, 123-135. gianotti f., forno m.g., ivy-ochs s., monegato g., pini r., ravazzi c. (2015) stratigraphy of the ivrea morainic amphitheatre (nw italy): an updated synthesis. alpine and mediterranean quaternary, 28, 29-58. gibbard p.l., head m.j., walker m.j.c., and the subcommission on quaternary stratigraphy (2010) formal ratification of the quaternary system/ period and the pleistocene series/epoch with a base at 2.58 ma. journal of quaternary science, 25, 96-102. glückert g. (1974) on pleistocene glaciations in the german alpine foreland. bulletin of the geological society of finland, 46, 117-131. gradstein f.m., ogg f.m., schmitz m.d., ogg g.m. (2020) geologic time scale 2020. vol. 2. elsevier, amsterdam, pp. 715. graf a., akçar n., ivy-ochs s., strasky s., kubik p.w., christl m., burkhard m., wieler r., schlüchter c. (2015) multiple advances of alpine glaciers into the jura mountains in the northwestern switzerland. swiss journal of geosciences, 108(2-3), 225 -238. graf h.r. (1993) die deckenschotter der zentralen nordschweiz. phd thesis eth zurich, pp. 150. graf h.r (1996) caliche-bildungen auf höheren deckenschotter der nordschweiz? eiszeitalter und gegenwart, 46: 48-53. graf h.r. (2009a) stratigraphie und morphogenese von frühpleistozänen ablagerungen zwischen bodensee und klettgau. quaternary science journal, 58(1), 12-53. graf h.r. (2009b) stratigraphie von mittelund spätpleistozän in der nordschweiz. swiss federal office of topography, swisstopo: bern, switzerland. karte der republik österreich 1:50.000, blatt 66 gmunden. geologische bundesanstalt, pp. 66. egger h., van husen d. (2011) erläuterungen zur geologischen karte der republik österreich 1:50.000, blatt 69 großraming. geologische bundesanstalt, pp. 119. ellwanger d., bibus e., bludau w., kösel m., merkt j. (1995) baden-württemberg. in: benda l. (ed.), das quartär deutschlands, bornträger, stuttgart, 255-295. ellwanger d., wielandt-schuster u., franz m., simon t. (2011) the quaternary of the southwest german alpine foreland (bodensee-oberschwaben, baden -württenberg, southwest germany). quaternary science journal, 60, 306-328. farmer j.r., hönisch b., haynes l.l., kroon d., jung s., ford h.l., raymo m.e., jaume-seguí m., bell d.b., goldstein s.l., pena l.d., yehudai m., kim j. (2019) deep atlantic ocean carbon storage and the rise of 100,000-year glacial cycles. nature geoscience, 12 (5), 355-360. doi: 10.1038/s41561-019-0334-6. fiebig m., ellwanger d., doppler g. (2011) pleistocene glaciations of southern germany. in: ehlers j., gibbard p.l., hughes p.d. (eds.), glaciationsextent and chronology. a closer look. elsevier, amsterdam, 163-173. fink j., fischer h., klaus w., koci a., kohl h., kukla j., lozek v., piffl l., rabeder g. (1976) exkursion durch den österreichischen teil des nördlichen alpenvorlandes und den donauraum zwischen krems und wiener pforte. mitteilungen der kommission für quartärforschung, 1: 31 s, wien. fink l., kukla g. (1977) pleistocene climates in central europe: at least 17 interglacials after the olduvai event. quaternary research, 7, 363-371. fioraso g., monegato g., balestro g., hajdas i., baggio p. (2021) disentangling the stratigraphic architecture of the rivoli-avigliana end moraine system (western alps, nw italy). journal of maps. doi: 10.1080/17445647.2021.1942252 florineth d., schlüchter c. (2000) alpine evidence for atmospheric circulation patterns in europe during the last glacial maximum. quaternary research, 54, 295-308. fontana a., mozzi p., bondesan a. (2010) late pleistocene evolution of the venetian-friulian plain. rend. lincei, 21 (suppl.1), 181-196. frei r. (1912) monographie des schweizerischen deckenschotters: beiträge zur geologischen karte der schweiz, n.f. 37, pp. 182. fromm k. (1989) paläomagnetische altersbestimmungen an eiszeitlichen quartärablagerungen bei heiligenberg (oberschwaben). niedersächsisches landesamt für bodenforschung, geowissenschaftliche gemeinschaftsaufgaben, bericht ar.-nr. 105863, 19 s., hannover. gaar d., preusser f. (2017) age of the most extensive glaciation of northern switzerland: evidence from the scientific drilling at möhliner feld. e&g quaternary science journal, 2017, 66, 1-5. gabert j. (1984) la naissance des terrasses wiirmi 143 the early and middle pleistocene glaciations in the alps graf h.r. (2019) die hoheren deckenschotter von albis, uetliberg und heitersberg. bulletin für angewandte geologie, 24, 3-25. graf h.r., burkhalter r. (2016) quaternary deposits: concept for a stratigraphic classification and nomenclature an example from northern switzerland. swiss journal of geosciences, 109(2), 137147. greenwood s.l., hughes a.l.c., winsborrow m.c.m. (2022) the eisc evolution prior to the last glacial maximum. in: palacios d., hughes p.d., ruiz j.m.g., de andrés n. (eds.), european glacial landscapes: maximum extent of glaciations. elsevier, amsterdam, 203-211. gribenski n., valla p.g., preusser f., roattino t., crouzet c., buoncristiani j.f. (2021) out-ofphase late pleistocene glacial maxima in the western alps reflect past changes in north atlantic atmospheric circulation. geology, 49, 10961101. grischott r., kober f., ivy-ochs s., hippe k., lupker m., bros e., maden c., christl m., vockenhuber c. (2020) dating quaternary terraces with cosmogenic nuclides in northern switzerland. unpublished nagra arbeitsbericht nab 19-025. grosswald m.g., kuhle m., fastook j.l. (1994) würm glaciation of lake issyk-kul area, tian sshan mts.: a case study in glacial history of central asia. geojournal, 33(2/3), 273-310. guerin c. (1980) les rhinoceros (mammalia perissodactyla) du miocene terminal au pleistocene superieur en europe occidentale. comparaison avec les especes actuelles. documents du laboratoire de geologie de lyon, 79, 1-1185. haldimann p., graf h.r., jost j. (2017) erläuterungen zum geologischen atlas der schweiz 1:25000, 1071 bülach (atlasblatt 151). bundesamt für landestopografie, swisstopo, pp. 151. häuselmann p., granger d.e., jeannin p.-y., lauritzen s.-e. (2007) abrupt glacial valley incision at 0.8ma dated from cave deposits in switzerland. geology, 35, 143-146. hughes p., gibbard p.l., ehlers j. (2020) the “missing glaciations” of the middle pleistocene. quaternary research, 96, 161-183. doi:10.1017/qua.2019.76 ivy-ochs s., monegato g., reitner j.m. (2022) the alps: glacial landforms prior to the last glacial maximum. in: palacios d., hughes p.d., ruiz j.m.g., de andrés n. (eds.), european glacial landscapes: maximum extent of glaciations. elsevier, amsterdam, 283-294. jamšek rupnik p., žebre m., jež j., zajc m., preusser f., monegato g. (2022) deciphering the deformation mechanism in quaternary deposits along the idrija fault in the formerly glaciated soča valley, southeast european alps. engeneering geology, 297, 106515. jordan p. (2010) analysis of overdeepened valleys using the digital elevation model of the bedrock surface of northern switzerland. swiss journal of geosciences, 103(3), 375-384. kamleitner s., ivy-ochs s., monegato g., gianotti f., akçar n., vockenhuber c., christl m., synal, h.a. (2022) the ticino-toce glacier system (swissitalian alps) in the framework of the alpine last glacial maximum. quaternary science reviews, 279, 107400. keller o., krayss e. (2010) mittel-und spätpleistozäne stratigraphie und morphogenese in schlüsselregionen der nordschweiz. e&g quaternary science journal, 59(1/2), 88-119. kelly m.a., buoncristiani j.f., schlüchter c. (2004) a reconstruction of the last glacial maximum (lgm) ice-surface geometry in the western swiss alps and contiguous alpine regions in italy and france. eclogae geologicae helvetiae, 97, 57-75. knudsen m.f., nørgaard j., grischott r., kober f., egholm d.l., hansen t.m., jansen j.d. (2020) new cosmogenic nuclide burial-dating model indicates onset of major glaciations in the alps during middle pleistocene transition. earth and planetary science letters, 549, 116491. kohl h. (1999) zur gliederung der rißmoränen in oberösterreich und ihre abgrenzung zu den mindelmoränen (subdivision of riss moraines in upper austria and their differentiation from mindel moraines). jahrbuch der geologischen bundesanstalt,141, 395-407. kohl h. (2000) das eiszeitalter in oberösterreich. schriftenreihe des oberösterreichischen musealvereins, 17, linz , 487 pp. königswald w., heinrich w.-d. (2007) biostratigraphische begriffe aus der säugetierpaläontologie für das pliozän und pleistozän deutschlands. eiszeitalter und gegenwart, 56, 96-115. krsnik e., methner k., campani m., botsyun s., mutz s. g., ehlers t. a., kempf o., fiebig j., schlunegger f., mulch a. (2021) miocene high elevation in the central alps. solid earth, 12, 2615-2631. doi: 10.5194/se-12-2615-2021 krūkle m., stelle v. (1964) mindel-rissian deposits in the town of krāslava. in: danilāns i. (ed.), questions of quaternary geology, vol. iii. publishing house of the academy of sciences of the latvian ssr, riga, 165-182. kuhlemann j., rahn m. (2013) plio-pleistocene landscape evolution in northern switzerland. swiss journal of geosciences, 106, 451-467. lehmkuhl f., klinge m., stauch g. (2011) the extent and timing of late pleistocene glaciations in the altai and neighbouring mountain systems. in: ehlers j., gibbard p.l., hughes p.d. (eds.), glaciations-extent and chronology. a closer look. elsevier, amsterdam, 967-979. lisiecki l.e., raymo m.e. (2005) a pliocenepleistocene stack of 57 globally distributed benthic d18o records. paleoceanography, 20, pa1003. doi: 10.1029/2004pa001071 lowick s.e., buechi m.w., gaar d., graf h.r., preusser f. (2015) luminescence dating of middle pleistocene proglacial deposits from northern switzerland: methodological aspects and stratigraphical conclusions. boreas, 44(3), 459-482. 144 monegato g. et al. morlot (1854) notice sur le quatemaire en suisse. bulletin de la société vaudoise des sciences naturelles, iv. s. 41. moser m., schnabel w. (2019) erläuterungen zur geologischen karte der republik österreich 1:50.000, blatt 72 mariazell. geologische bundesanstalt, pp. 229. mühlberg f. (1896) der boden von arau. festschrift zur einweihung des neuen kantonsschulgebäudes in aarau. mitteilungen der aargauischen naturforschenden gesellschaft, h. vii, 1-51. muttoni g., carcano c., garzanti e., ghielmi m., piccin a., pini r., rogledi s., sciunnach d. (2003) onset of major pleistocene glaciations in the alps. geology, 31, 989-992. muttoni g., ravazzi c., breda m., pini r., laj c., kissel c., mazaud a., garzanti e. (2007) magnetostratigraphic dating of an intensification of glacial activity in the southern italian alps during marine isotope stage 22. quaternary research, 67, 161173. nangeroni g. (1940) considerazioni sul quaternario dell’alta pianura lombarda. bollettino comitato glaciologico italiano, 20, 63-72. nagl h. (1970) zur rekonstruktion der pleistozänen vereisung im alpinen ybbstal. mitteilungen der geologischen gesellschaft 63, 185-202. nicolis e. (1899) triplice estensione glaciale ad oriente del lago di garda. atti regio istituto veneto scienze lettere ed arti, 58(2), 316-319. omboni g. (1861) i ghiacciai antichi ed il terreno erratico della lombardia. atti società italiana di scienze naturali, 6, 232-299. orombelli g. (1979) ii ceppo dell'adda: revisione stratigrafica. rivista italiana di paleontologia e stratigrafia, 85, 573-652. orombelli g., palombo m.r., ravazzi c. (2023) introduction to quaternary studies in italy: from arduino to the first half of the past century. alpine and mediterranean quaternary, 36 (1), 2023, 1-33. doi: 10.26382/amq.2023.04 penck a. (1882) die vergletscherung der deutschen alpen, ihre ursachen, periodische wiederkehr und ihr einfluss auf die bodengestaltung. johann ambrosius barth, leipzig, pp. 483. penck a., brückner e., du pasquier l. (1894) le système glaciaire des alpes. bulletin de la société des sciences naturelles de neuchâtel, 22, 70-83. penck a., brückner e. (1901-1909) die alpen im eiszeitalter. tauchnitz, leipzig, pp. 1199. piana f., fioraso g., irace a., mosca p., d’atri a., barale l., falletti p., monegato g., morelli m., tallone s., vigna g.b. (2017) geology of piemonte region (nw italy, alps-apennines interference zone). journal of maps, 13, 395-405. pignalosa a., zattin m., massironi m., cavazza w. (2011) thermochronological evidence for a late pliocene climate-induced erosion rate increase in the alps. international journal of earth sciences, 100, 847859, pini r., ravazzi c., orombelli g. (2002) le “argille sotto il ceppo” di paderno d’adda: nuovi dati paliluetscher m., boch r., sodemann h., spötl c., cheng h., edwards r. l., frisia s., hof f., müller w. (2015) north atlantic storm track changes during the last glacial maximum recorded by alpine speleothems. nature communications, 6, 6344. doi: 10.1038/ncomms7344 mandier p. (1982) pluralité del glaciations dans la région lyonnaise et la moyenne vallée du rhone. in: billard a., conchon o., shotton f.w. (eds.), report for the ninth session of igcp project 73/1/24 quaternary glaciations in the northern hemisphere, 184-204. marcolla a., monegato g., mozzi p., miola a., stefani c. (2021) seesaw longitudinal-transverse fluvial patterns driven by middle and late pleistocene climatic cycles in the southern foreland basin of the eastern alps. sedimentary geology, 421, 105960. martinetto e., monegato g., vassio e. (2012) a lower pleistocene plant assemblage with east european affinity in the friulian piedmont plain (ne italy). alpine and mediterranean quaternary, 25(2), 91104. martins c., gastaldi b. (1850) essai sur le terrins superficiels de la vallée du po, aux environs de turin, comparés a ceux de la plaine suisse. bull. soc. gèol. france, 7, 554-602. menzies j., ellwanger d. (2010) insights into subglacial processes inferred from the micromorphological analyses of complex diamicton stratigrahy near illmensee-lichtenegg, höchsten, germany. boreas, 40, 271-288. mihevc a., bavec m., häuselmann p., fiebig m. (2015) dating of the udin boršt conglomerate terrace and implication for tectonic uplift in the nortwesthern part of the ljubljana basin (slovenia). acta carsologica, 44, 169-176. monegato g., stefani c. (2011) preservation of a longlived fluvial system in a mountain chain: the tagliamento valley (southeastern italian alps). in: davidson s.k., leleu s., north c.p. (eds.), from river to rock record: the preservation of fluvial sediments and their subsequent interpretation. society for sedimentary geology, special publication, 97, 359-374. monegato g., poli m.e. (2015) tectonic and climatic inferences from the terrace staircase in the meduna valley, eastern southern alps, ne italy. quaternary research, 83(1), 229-242. doi: 10.1016/j.yqres.2014.10.001 monegato g., ravazzi c. (2018) the late pleistocene multifold glaciation in the alps: updates and open questions. alpine and mediterranean quaternary, 31, 225-229. monegato g., lowick s.e., ravazzi c., banino r., donegana m., preusser f. (2010) middle to late pleistocene chronology and palaeoenvironmental evolution of the south-eastern alpine foreland: the valeriano creek succession (ne italy). journal of quaternary science, 25, 617-632. monegato g., scardia g., hajdas i., rizzini f., piccin a. (2017) the alpine lgm in the boreal ice-sheets game. scientific reports, 7(1), 2078. 145 the early and middle pleistocene glaciations in the alps nologici e biostratigrafici. istituto lombardo (rendiconti scientifici) b, 136, 93-122. pini r., ravazzi c., donegana m. (2009) pollen stratigraphy, vegetation and climate history of the last 215 ka in the azzano decimo core (plain of friuli, north-eastern italy). quaternary science reviews, 28, 1268-1290. preusser f., schlüchter c. (2004) dates from an important early late pleistocene ice advance in the aare valley, switzerland. eclogae geologicae helvetiae, 97, 245-253. preusser f., drescher-schneider r., fiebig m., schlüchter c. (2005) re-interpretation of the meikirch pollen record, swiss alpine foreland, and implications for middle pleistocene chronostratigraphy. journal of quaternary science, 20(6), 607620. preusser f., reitner j.m., schlüchter c. (2010) distribution, geometry, age and origin of overdeepened valleys and basins in the alps and their foreland. swiss journal of geosciences, 103, 407-426. preusser f., graf h.r., keller o., krayss e., schlüchter c. (2011) quaternary glaciation history of northern switzerland. e&g quaternary science journal, 60, 282-305. preusser f., büschelberger m., kemna h.a., miocic j., mueller d., may j.-h. (2021) exploring possible links between quaternary aggradation in the upper rhine graben and the glaciation history of northern switzerland. international journal of earth sciences, 110, 1827-1846. pugin a., bezat e., weidmann m., wildi w. (1993) le bassin d’ecoteaux (vaud, suisse): temoin de trois cycles glaciaires quaternaires. eclogae geologicae helvetiae, 86, 343-354 rades e.f., fiebig m., lüthgens c. (2018) luminescence dating of the rissian type section in southern germany as a base for correlation. quaternary international, 478, 38-50. ravazzi c., pini r., breda m., martinetto e., mattoni g., chiesa s., confortini f., egli r. (2005) the lacustrine deposits of fornaci di ranica (late early pleistocene, italian pre-alps): stratigraphy, palaeoenvironment and geological evolution. quaternary international, 131, 35-58. ravazzi c., pini r., breda m. (2009) reconstructing the palaeoenvironments of the early pleistocene mammal faunas from the pollen preserved on fossil bones. quaternary science reviews, 28, 2940-2954. reitner j.m. (2022) the imprint of quaternary processes on the austrian landscape. in: embletonhamann c. (ed.), landscapes and landforms of austria. world geomorphological landscapes. springer, 47-72. doi: 10.1007/978-3-030-92815-5_3 reitner j. m., gruber w., römer a., morawetz r. (2010) alpine overdeepenings and paleo-ice flow changes: an integrated geophysical-sedimentological case study from tyrol (austria). swiss journal of geosciences, 103(3), 385-405. rossato s., monegato g., mozzi p., cucato m., gaudioso b., miola a. (2013) late quaternary glaciations and connections to the piedmont plain in the prealpine environment: the middle and lower astico valley (ne italy). quaternary international, 288, 8-24. rupp c., linner m., mandl g.w. (2011) erläuterungen zur geologischen karte der republik österreich 1:200.000, blatt oberösterreich. geologische bundesanstalt, pp. 255. sacco f. (1887) l’anfiteatro morenico di rivoli. bollettino del regio comitato geologico italiano, 5-6, 141-180. salcher b.c., starnberger r., götz j. (2015) the last and penultimate glaciation in the north alpine foreland: new stratigraphical and chronological data from the salzach glacier. quaternary international, 388, 218-231. scardia g., muttoni g. (2009) paleomagnetic investigations on the pleistocene lacustrine sequence of pianico-sellere (northern italy). quaternary international, 204, 44-53. doi: 10.1016/j.quaint.2008.06.017 scardia g., muttoni g., sciunnach d. (2006) subsurface magnetostratigraphy of pleistocene sediments from the po plain (italy): constraints on rates of sedimentation and rockuplift. gsa. bulletin, 118, 1299-1312. doi:10.1130/b25869.1 scardia g., donegana m., muttoni g., ravazzi c., vezzoli g. (2010) late matuyama climate-driven alluvial fan progradation at the alpine southern foothills. quaternary science reviews, 29, 832846. scardia g., de franco r., muttoni g., rogledi s., caielli g., carcano c., sciunnach d., piccin a. (2012) stratigraphic evidence of a middle pleistocene climate driven flexural uplift in the alps. tectonics, 31, tc6004. scardia g., festa a., monegato g., pini r., rogledi s., tremolada f., galadini f. (2015) evidence for late alpine tectonics in the lake garda area (northern italy) and seismogenic implications. geological society of america bulletin, 127, 113-130. schaefer i. (1956) sur la division du quaternaire dans l’avant pays des alpes en allemagne. actes iv. congress international du quaternaire (inqua), rome/pise, 1953, vol. 2: 910-914. schielein p., schellmann g., lomax j., preusser f., fiebig m. (2015) chronostratigraphy of the hochterrassen in the lower lech valley (northern alpine foreland). e&g quaternary science journal, 64, 15-28. schlüchter c. (1981) remarks on the pleistocene morphogenetic evolution of the swiss plain. zeitschrift für geomorphologie, n.f. suppl.-bd., 40, 61-66. schlüchter c. (1986) the quaternary glaciations of switzerland, with special reference to the northern alpine foreland: final report of the igcp project 24 quaternary glaciations of the northern hemisphere. quaternary science reviews, 5, 413-419. schlüchter c. (1988) the deglaciation of the swiss alps: a paleoclimatic event with chronological 146 monegato g. et al. sheet growth in the north atlantic region. quaternary science review, 44, 229-240. uggeri a., felber m., bini a., bignasca c., heller f. (1997) the valle della fornace succession. geologia insubrica, 2, 69-80. valla p., shuster d.l., van der beek p.a. (2011) significant increase in relief of the european alps during mid-pleistocene glaciations. nature geoscience, 4, 1242. doi: 10.1038/ngeo1242 van husen d. (1975) die quartäre entwicklung des steyrtales und seiner nebentäler. jahrbuch des oberösterreichischen musealvereines,120, 271289. van husen d. (1989) die entwicklung des krappfeldes und seiner weiteren umgebung im pliozän und pleistozän. arbeitstagung der geologischen bundesanstalt, 107-119. van husen d. (2000) geological processes during the quaternary. mitteilungen der österreichischen geologischen gesellschaft, 92, 135-156. van husen d., egger h. (2014) geologische karte der republik österreich 1:50.000, erläuterungen zu blatt 65 mondsee. geologische bundesanstalt, pp. 143. van husen d., reitner j.m. (2011a) an outline of the quaternary stratigraphy of austria. quaternary science journal 60, 366-387. van husen d., reitner j.m. (2011b) klimagesteuerte terrassenund lössbildung auf der traun-ennsplatte und ihre zeitliche stellung (das profi l wels/ aschet). mitt. komm. quartärforsch. österr. akad. wiss., 19, 1-11. venetz i. (1833) memoire sur les variations de la température dans les alpes de la suisse (rédigé en 1821). memoires de la societe helvetique des sciences naturelles, 1, 1-38. venzo s. (1950) rinvenimento di anacus arvernensis nel villafranchiano dell’adda di paderno, di archidiskodon meridionalis e cervus a leffe. stratigrafia e clima del villafranchiano bergamasco. atti soc. it. sc. nat., 89, 43 122. venzo s. (1957) rilevamento geologico dell'anfiteatro morenico del garda. parte i, tratto occidentale gardone. memorie società italiana di scienze naturali, 12, 1-140. venzo s. (1961) rilevamento geologico dell’anfiteatro morenico del garda: parte ii. memorie società italiana di scienze naturali, 13, 1-64. venzo s. (1965) rilevamento geologico dell’anfiteatro morenico frontale del garda dal chiese all’adige. memorie società italiana di scienze naturali, 14, 1 -82 venzo s. (1977) i depositi quaternari e del neogene superiore nella bassa valle del piave da quero al montello e del paleopiave nella valle del soligo (treviso). memorie degli instituti mineralogia e geologia dell’università di padova, 30, 1-64. wannier m.m.a. (2023) no publication, no fame: reassessing arnold guyot’s (1807-1884) pioneering contributions to the glacial theory. earth sciences history, 42(1), 123-159. problems. bulletin de l’association française pour l’étude du quarternaire, 2, 141-145. schlüchter c. (1989) a non-classical summary of the quaternary stratigraphy in the northern alpine foreland of switzerland. bulletin de la société neuchâteloise de géographie, 23, 143-157. schlüchter c., akçar n., ivy-ochs s. (2020) the quaternary period in switzerland. in: reynard e. (ed.) landscapes and landforms of switzerland (4769). springer, cham. scholger r., terhorst b. (2013) magnetic excursions recorded in the middle to upper pleistocene loess/ palaeosol sequence wels-aschet (austria). e&g quaternary science journal, 62, 14-21. schreiner a. (1997) einführung in die quartärgeologie. schweizerbart, stuttgart, pp. 257. schreiner a., ebel r. (1981) quartärgeologische untersuchungen in der umgebung von interglazialvorkommen im östlichen rheingletschergebiet (baden-württemberg). geol. jahrbuch, a59, 3-64. schwenk m.a., schläfli p., bandou d., gribenski n., douillet g.a., schlunegger f. (2022) from glacial erosion to basin overfill: a 240 m-thick overdeepening-fill sequence in bern. scientific drilling, 30, 17-42. shackleton n.j., pisias n.g. (1985) atmospheric carbon dioxide, orbital forcing, and climate. geophysical monograph series, 32, 303-317. šibrava v., bowen d.q., richmond g.m. (1986) quaternary glaciations in the northern hemisphere. report igcp n° 24, quaternary science reviews, 5(1-4). spreitzer h. (1961) der eiszeitliche murgletscher in steiermark und kärnten. geographischer jahresbericht aus österreich, 28, 1-50. sternai p., sue c., husson l., serpelloni e., becker t.w., willet s.d., faccenna c., di giulio a., spada g., jolivet l., valla p., petit c., nocquet j.-m., walpersdorf a., castelltort s. (2019) present-day uplift of the european alps: evaluating mechanisms and models of their relative contributions. earth-science reviews, 190, 589-604. taramelli t. (1875) dei terreni morenici e alluvionali del friuli. annali regio istituto tecnico udine, 8, 1-91. terhorst b. (2013) a stratigraphic concept for middle pleistocene quaternary sequences in upper austria. quaternary science journal, 62, 4-13. terhorst b., ottner f. (2003) polycyclic luvisols in northern italy: palaeopedological and clay mineralogical characteristics. quaternary international, 106/107, 215-231. terhorst b., ottner f., wriessnig k. (2012) weathering intensity and pedostratigraphy of the middle to upper pleistocene loess/palaeosol sequence of wels-aschet (upper austria). quaternary international, 265, 142-154. thierens m., pirlet h., colin c., latruwe k., vanhaecke f., lee j.r., stuut j.-b.w., titschack j., huvenne v.a.i., dorschel b., wheeler a.j., henriet j.-p. (2012) ice-rafting from the british-irish ice sheet since the earliest pleistocene (2.6 million years ago): implications for long-term mid-latitudinal ice 147 the early and middle pleistocene glaciations in the alps doi: 10.17704/1944-6187-42.1.123 weinberger l. (1955) exkursion durch das österreichische salzachgletschergebiet und die moränengürtel der irrseeund attersee-zweige des traungletschers. verhandlungen der geologischen bundesanstalt, 1955, 7-34, wien. winterberg s., willett s.d. (2019) greater alpine river network evolution, interpretations based on novel drainage analysis. swiss journal of geosciences, 112, 3-22. zanferrari a., avigliano r., monegato g., paiero g., poli m.e. (2008) note illustrative della carta geologica d'italia alla scala 1:50.000 foglio 066 “udine”. graphic linea, tavagnacco, pp. 176. zanferrari a., masetti d., monegato g., poli m.e. (2013) note illustrative della carta geologica d'italia alla scala 1:50.000 foglio 049 “gemona del friuli”. ispraregione autonoma friuli venezia giulia, pp. 262. zuccoli l. (2000) geologia dei pianalti di castelseprio e tradate (provincia di varese). il quaternario italian journal of quaternary science, 13, 57-80. 148 ms. received: february 28, 2023 revised: may 4, 2023 accepted: may 8, 2023 available online: may 22, 2023 ii quaternario 7 (2), 1994, 677-692 workshop on marine sections from the gulf of taranto (southern italy) usable as potential stratotypes for the gssp of the lower, middle and upper pleistocene (bari, italy, sept. 29 • oct. 4, 1994) m. b. cita (workshop convener) d. castradori (workshop rapporteur) dip.to di scienze della terra, universita di milano, milano, italy background the quaternary working group of the italian commission on stratigraphy organized a first workshop in november 1992 in sicily and calabria to investigate and discuss in the field several marine, fossiliferous, continuous, well exposed sections potentially usable as stratotypes for the pliocene and lower pleistocene. at the conclusion of the workshop, the possibility of introducing a new stage for the upper pliocene, to fill the gap existing in between the top of the piacentian and the n/q boundary as defined by its gssp at vrica, was discussed and considered viable. the san nicola section (see channell et al., 1992) close to gela (sicily) visited during the workshop, was considered to meet the international requirements. on the contrary, other exposures visited during the november 1992 workshop and previously proposed as stratotypes for the "selinuntian" (lower pleistocene) by ruggieri & sprovieri (1979) and for the "crotonian" (middle pleistocene) by ruggieri et al. (1977) were judged, by the working group, unsuitable as a reference for a global standard because of their near-shore setting strongly affec­ ted by eustatic/tectonic disturbances, and consequent sedimentary gaps. highly interesting exposures of terrigenous to hemipelagic sediments deposited in the depocenter of the apennine foredeep (nw of the gulf of taranto) were visited: there the marine sedimentation lasted longer than in other sicilian and calabrian peripheral basins, extending into the middle pleistocene. professor n. ciaranfi from the university of bari and his associates are actively working in the area, in order to provide the necessary stratigraphic multi-proxy data. after the 1992 workshop, a) professor g.b. vai, from the university of bologna, concentrated on a critical re-visitation of all the mari­ ne pleistocene stages previously defined in italy, some of them largely used in the international literature, others more obscure or misused; b) the gelasian stage was proposed (rio et al., 1994) with reference to the san nicola section mentioned above, and c) a gssp was defined for the base of the emilian stage in the vrica section, 75 m above the pliocene/pleistocene gssp (pasini & colalongo, 1994 ). --------------bari mare adria tico brindisi mar piccolo di taranto ~oi montalbanojonlco i\ • ! middle pleistocene gallipoli upper pleistocene / mare ionio crotone . lower pleistocene ;:, l--1 10km the 1994 workshop purpose of the second workshop was to extend the in-situ observa­ tions and discussions to the marine sections of the middle and upper pleistocene, moving around the gulf of taranto (fig. 1 ), where spectacu­ lar strombus-bearing raised beaches occur. the workshop consisted of three parts: 1) visit to the upper pleistocene sections near gallipoli and taranto (mare piccolo), under the guidance of ors . dai pra and mazzanti (september 29-30); 2) discussion of the basic philosophy and principles of stratigraphy as applied to the quaternary marine sequences. boundary stratotypes versus stage stratotypes, with reference to the newly published international stratigraphic guide (salvador a., editor, 1994) (bari, october 1); 3) visit to the vrica section under the guidance of dr. g. pasini and to the middle pleistocene sections of the apennine foredeep (fossa bradanica) under the guidance of prof. n. ciaranfi. fig. 1 location map. mappa de/le localita. 678 the workshop was long planned by the quaternary working group of the italian commission on stratigraphy, but the new devel­ opments of the quaternary subcommission of the international commission on stratigraphy (ics) and the proximity of the inqua congress (berlin, 1995) suggested to make it more open and international. aiqua, the italian association for the study of the quaternary, and the subcommission on neogene stratigraphy of the ics co­ sponsored the workshop. 9.1 13]1 i\i·dz 1-13 b e ·········· ···· · ..... .. ........ ···· ·· ······ ·· · .... ............ . : :: : r:-,.:::::::::: igali ,;:::::: . ... . . p.9 . ..... . 0 xjo zoo .joo m ······ ···· · ·· ·· 0.4!+0,04 (15) c' mlllb -~ _ _,'.:.-;:;,_-,;,-,.c;-"""......,"-'1£(1> / miiia __.....,=~~"! / ':~jri.~-~i':'.:: [id 0.15!0.03 (5) a fig. 2 quaternary stratigraphy of the area around gallipoli {after hearty & dai pra, 1992). stratigrafia def quatemario del/'area circostante gallipoli (da hearty & dai pra, 1992). excursions the first two days of the workshop were dedicated to visit out­ crops of tyrrhenian sediments in stratigraphic contact with underlying and overlying strata near gal lipoli (figs. 2 & 3) and in the area around the mar piccolo di taranto (figs. 4 & 5).the tyrrhenian raised beaches are richly fossiliferous, and several radiometric age determinations based on aminoacids analyses and u/th support their stratigraphic attribution (see hearty and dai pra, 1992, and references therein) . the outcrops of the area around the mare piccolo appeared the most promising for the definition of a gssp for the good condi­ tions of the exposures (eventually subject to be further improved with artificial cuts) and the thickness of the deposits. 3 2 0 4 d' a the vrica section near crotone, which extends from the upper pliocene to the lower pleistocene, and where the gssp for the p/p boundary was formally defined (bassett, 1985; aguirre and pasini, 1985), was subsequently visited. the same section has been recen­ tly used by pasini and colalongo (1994) to propose the gssp of the fig. 3 workshop partecipants walk on the shore of gallipoli towards a tyrrtienian outcrop (29/9/1994) . partecipanti de/workshop sulla spiaggia di gallipoli verso un affioramen­ to def tirreniano {29/9/1994). emilian substage (santernian/emilian boundary) at level p, some 75 m above the p/p gssp. the main biostratigraphic criteria usable to recognize the base of the emilian are the first occurrence of hyalinea balthica and the first occurrence of large gephyrocapsa, with an b 134 ka c -----;.o._ ___ _.flun d 1-1026 [§] 028 mii 0.39 mv ,=-miii 679 e gj f b' .,es,: jo ~~ ~-==---=~ 20 ,. •oo 200 0 fig. 4 quaternary stratigraphy of the area around the mar piccolo di taranto (after hearty & dai pra, 1992). stratigrafia dei depositi quaternari dell'area circostante if mar piccolo di taranto (da hearty & dai pra, 1992). interpolated age of approximately 1 .48 ma. figure 6 (after pasini and colalongo, 1994) shows the distribution of calcareous nannofossils in the vrica section and the position of the santemian in this section, whereas fig. 7 shows the position of level e, which identified the p/p gssp. if the classic vrica section was already familiar to several workshop participants, the montalbano lonico section, here presented as potential reference for the middle pleistocene, was only known to a limited number of scientists who had taken part to the 1992 workshop. a terrific work has been accomplished in less than two years, and is concisely reported in the following pages (see also figs. 8-11). th e montalbano jonico section in the bradanic foredeep (southern italy): a potential early-middle pleistocene boundary stratotype (contribution by: n. ciaranfi, a. d' alessandro, m. marino & l. sabato geology and geophysics dept., university of bari) in the south-western part of the bradanic foredeep, not far from the present-day gulf of taranto shoreline, along the agri river, west of montalbano jonico, a new detailed geological mapping (fig. 8) has shown some continuous stratigraphic successions, previously attributed to the early pleistocene (verhallen, 1991 ). the reconstructed section of montalbano jonico (fig . 9) that forms a monocline gently dipping towards se, has a thickness of about 350 m. it mainly consists of well stratified silty clays, intercalated fig. 5 workshop participants sample a tyrrhenian/pre-tyrrhenian section at punta penna, mar piccolo di taranto (30/9/94) partecipanti def workshop mentre campionano una sezione def tirreniano/pre-tirreniano a punta penna, mar piccolo di taranto (30/09/94). 680 legend : ~ 1 1pedm•n . ~ ~ . .,. ' s ~ sc•,.c e ;i i i ~ . i abr.ind■ "'.;/"'comfflcl'\ ~ : . . . ::! ~ ~ i 15 3 « i l l l ! ◄ ◄ . :;; ~ ~ .i v i 0 columnar ~ ~ 8 .1 g i section 1, :,: i a ~ 0 " i5 r ~ ~ ~ i i i i i i w joo 1z l w s---·1 .i ,,___ 0 q ---0 . i 25il . ii i p cl) 0 ----nw m i ..j i a. 200 ~1~-:-:,:,:, g~ '" ,........ e w d~ iso c-' . z b. w a. . 0 ,oo 0 i . ...i . i . • • . 50 a. i i . i i i i i i . . . : i i . i ' mo i i fig. 6 • distribution of calcareous nannofossils in the vrica section and definition of santernian/emilian boun­ dary (after pasini & colalongo, 1994). distribuzione dei nannofossili cafcarei neffa sezione di vrica e definfzione def fimite santeriano/emiliano (da pasini & colalongo, 1994). with several volcaniclastic layers (v1-v9) and marly-silty and/or sandy-silty bodies; these lithohorizons are useful to correlate successions of different localities. the nine volcaniclastic layers consist of pure ash, sand rich in volcanic minerals and pumice clasts. they belong, from a compositional and geochem­ ical point of view, to two different series (de rosa, pers. comm.): alkaline undersaturated volcanism (v1-v4) and calcoalkaline volcanism (v5-v9). the upper part of the montalbano section represents the local regressive emicycle of the foredeep, due to the presence of marine sands and conglomerates at the base, and of continental conglomerates at the top (figs . 10-1 1) . biostratigraphic analyses of nannofloral assemblages based on several sam­ ples collected from the middle part of the section (about 250 m thick), allowed us to recognize three pleistocene biozones according to the rio et al. (1990) scheme (fig . 9). the lower part of the sampled section has been referred to the large gephyrocapsa zone; the interval between the v1 layer and a strati ­ graphic level 5 m below the v2 layer has been referred to the small gephyrocapsa zone: both biozones indicate the younger part of the early pleistocene . the upper part of the sampled section is referable to the pseudoemiliania /acunosa zone, on the basis of the occurrence of gephyrocapsa para/le/a ( gephyrocapsa sp. 3, sensu rio, 1982). the distribution of this species (first occurrence at 944 ka, last occurrence at 584 ka, castradori, 1993) is discon­ tinuous in the mediterranean area with a ''temporary disappearance" (recorded in the montalbano section near the v3 layer) and a "reappearance" (in the montalbano section 20 m above the v4 layer) (see rio et al., 1990; castradori, 1993). the above mentioned results suggest the presence of the early-middle pleistocene boundary in the montalbano section. researches are in progress, including: sedimentology, calcareous nannofossil biostratigraphy, planktonic and benthonic foraminiferal biostratigraphy, paleoecology of macrofossil communities, petrology of volcaniclastic layers, magnetostratigraphy, radiometric dating. discussion one full day (october 1, 1994) was dedicated to discuss the principles, the sections, the chronostratigraphic subdivisions to be proposed. in order to prevent a disorganised discussion and to pro­ vide all the background information available, a tentative program was dressed (table 1). all the planned presentations were given with minor changes in the schedule. table 2 provides the list of workshop participants, with their home institutions and qualifications. the discussions were alive and sometimes heated, especially those concerning the lower and the upper pleistocene. the points of discussion may be categorized as follows: a) the principles of stratigraphy, as applied to the definition of boundary strato­ types, with reference to the new guide (salvador a., editor, 1994), and the role that priority plays versus world-wide correlability. see also contribution by j. van couvering in the following pages, a document distributed to all workshop participants. b) the major boundaries. on this point the consensus was full. the lower pleistocene has to start with the gssp defined, and formally accepted, in the vrica section (bassett , 1985; aguirre & pasini, 1985). there is no reason whatsoever to change its position, which has a correlation potential much better known now than ten years ago. the middle pleistocene should start with a point close to the upper jaramillo reversal, to isotopic stage 25 and to the small gephyrocapsa/pseudoemi/iania lacunosa nannofossil fig. 7 • workshop participants g.b. vai and s.laccarino sit on the pliocene/pleistocene gssp in the vrica section (2/10/94). i parlecipanti def workshop g.b. vai e s. lacca· rino sul gssp pliocene/pleistocene neffa sezione di vrica (2110/94). zonal boundary. such a point was considered to have a better correlation potential than a boundary coinciding with the brunhes/matuyama magnetic reversal. the proposed lower/middle pleistocene boundary is easily recognizable in the land record on the basis of mammal faunas (see contribution by a. azzaroli later on) . n a i ( mass. i .a monty "' / ,/ji(,( / ~ ._,,,"'vs v• • • v3 • • • • v2 v v v y v1 a)--.s ,;( 5 ..,......-,8 -7 v .., .., 8 v v v c:tzj i / , ____ .,.., '.,,.. '-' i c. \ (. c. c. \ c. l l / l c. l (. (. ( ,(/'-150 ,,,, ....... ..-l "'"'.,,,, -5 i ,.... ,,,......_ 'i /; i / i/ ....__.,,.... l '_) i . ' \ km 681 fig. 8 sketch map of the area studied by ciaranfi et al. (1994) near montalbano lonico; 1: alluvial deposits; 2: continental conglomerates; 3: marine sands and conglomerates; 4: silty clays and clayey silts; 8: landslides; s: measured sections. carta schematica del/ 'area studiata da ciaranfi et al. (1994) in vicinanza di montalbano lonico; 1: depositi alluvionali; 2: conglomerati continentali; 3: sab­ bie e conglomerati marini; 4: argille limose e limi argillosi; 8: frane; s: sezioni misurate. the upper pleistocene also obtained a general consensus; it had to start with termination ii, with the transition from isotopic stage 6 to stage 5 and with the base of the oldest strombus raised beach. c) the names to be used for the stage corresponding to the lower, middle and upper pleistocene, as defined above. the discussion of this item was really heated and difficult sometimes, maybe because some workshop participants were person­ ally involved as proponents of new stage names, or users of chronostratigraphic units not properly defined , or not largely used elsewhere or both. points of discussion were the role of priority in the definition of a stage, the opportunity to emend deeply rooted terms, widely used in the international literature; the importance to have a good standard reference section with a clearly defined gssp versus the interpretation given tens of years ago by various authors to some poorly known fossil localities, at times when several proxy data now used in the integrated stratigraphic approach were not available yet. further details on the discussion points are found in cita and castradori (in press, bollettino societa geologica ltaliana) to which reference is made. 682 111 l e ~ z ~ 111 "' .,, 0 c: 0 ~ ..!!! .!!! 0 c: -!!! "" e r .., .g ::, "' 00 .,, 0.. -l 111 11 .j u ~ e,j .!! i(!) ~ l § 2 legend sl .; 1n "' 0 0 ... ., iii "' :!.2 iij 0 u. 0 .• sl 0 > .!! 0 -.; ..., ,g 0 iii" ' .!: 0 .!: 0 5l "' 0 u. < section of montalbano jonico 20 main calcareous nannofossils ~ .,, e ... "' l ~ ii) x: i i i i i i i i i i i i i i i i • i i i i i i i i i i i i i i <> [ -c: q. ii) (!) cu ~ uj "' ~ "' c: "' -~ "' c: .q "' :@ t "' 0 <> :i = i g. <> [ l -c: g. ii) (!) (!) 0 c: = = q. "' ~ i i ... q. c: .., ..'!! (!) .s! ::, ., ;g e' ii) .!! 12:: .!! "' == e "' q. "' "' q. "' 0 i cd (!) i i i :i 0 § <> ..!!! -!!! c: -!!! :::: e ii) .g ::, ... ~ 1°0 ° i conglomerates ~ sandsand conglomerates -~ sandy sils and/or many silta illy clays -voldinicla&lic laye111 fig. 10 workshop participants climb the beautifully exposed fosso ldeale section (3/10/1994). partecipanti al workshop si arrampicano su/ bellissimo affioramento de/la sezione di fosso ideate (3/1011994). fig. 9 composite section of montalbano lonico and distribution of calcareous nannofossils (after ciaranfi eta!., 1994). sezione composita di montalbano lonico e distribuzio­ ne dei nannofossili calcarei (da ciaranfi et al., 1994). i fig. 11 panoramic view of the badlands west of montalbano lonico; vs is a prominent volcaniclastic marker-bed. panorama de/le argi/le a calanchi (badlands) ad ovest di montalbano lonico; vs indica uno strata guida di materiale c/astico di origine vu/canica. proposals table 1 program of the "discussion day". programma de/ "discussion day". societa geologica ltaliana commissions ltaliana di stratigrafia gruppo di lavoro per ii quaternario ass0ciazione italiana per lo studio del ouaternario presidents m.b. gita segretario a. bini international union of geological sciences international commission on stratigraphy subcommission on neogene stratigraphy workshop on marine sections from the gulf of taranto (southern italy) usable as potential stratotypes for the gssp of lower, middle and upper pleistocene october 1 discussion day tentative ag enda morning session 9.30 -12.30 9.30 m.b. crta the workshop: background and motivation 9.50 d. rro & r. srrovrrnr early pleistocene section and possible subdivision sns 10.1 o n. craranfi the evolution of chain-foredeep-foreland system in southern italy: geody­ namic explanation for the presence of continuous quaternary sections and possible sub­ division: present-day knowledge and related problems 10.30 d. rro stratigraphic and biostratigraphic evidences for middle pleistocene 10.50 r. mazzanti & g. dar pra late pleistocene (tyrrhenian) sections 11.30 j. van couvrn1ng what is the relationship between the base of quaternary and the base of pleistocene? general discussion afternoon session 14.30 18.30 14.30 g.c. pasini & j. van couvering the gssp of the vrica section and its world-wide correlability 15.00 a. azzaroli & p. ambros etti the point of view of continental stratigraphers 15.20 a. d'alessandro ecostratigraphy and its application to the montalbano sections 15.40 n. craranfr presentation of the excursion 16.00 coffee break 16.20 17.20 general discussion possibly followed by a round table discussion interventions by m. bassett, g.b. vai, d. rro, j. van couvering, i. raff! are foreseen 683 the proposed subdivision presented here (fig. 12) is the main result of the workshop(s). it has not been approved by consensus, but results from a) two polls among workshop participants, the first questionnaire being distributed after the general discussion in bari, the second one, with even more focussed questions, after another meeting held in crotone on october 2, 1994 and b) a postal ballot among the members of the quaternary working group of the italian commission on stratigraphy (indicated as glq on table 2) . the rules of iugs have been applied (60% quorum) to calculate the majority, which was large enough as to consider the proposed subdi­ vision on firm grounds. the following comments are aimed at clarifying the scheme, which extends into the pliocene, starting from its lower, older parts. the gelasian stage has been recently proposed (rio et al., 1994) for the stratigraphic interval above the piacenzian and above the event at approximately 2.5 ma (final event of the gradual initiation of glaciation in the northern hemisphere). this interval was not covered by a formal chronostratigraphic unit defined by a stratotype (rio et al., 1991; cita et al., in press). the gssp at the base of the gelasian has been proposed in the san nicola section (sicily) in a position slightly postdating the gauss/matuyama magnetic reversal (rio eta/., 1994). the pliocene/pleistocene boundary, located in the vrica section at the base of the marls overlying sapropelic layer "e" (see fig. 7) is the only one represented in fig . 12 to have been formally accepted by ics and ratified by iugs (bassett, 1985; aguirre & pasini, 1985). the italian working group is strongly supportive of its validity and worldwide correlability. it is pointed out that the scheme (fig. 12) does not include a formal tripartition of the pleistocene series in subseries (lower, 684 table 2 • workshop participants, including affiliations and qualifications. i partecipanti al workshop, con indicazione de/la qua/ifica e dell'organizzazione di appartenenza. ambrosetti, p. * dip. scienze terra palreontology professor univ. perugia italian delegate at inqua glq azzaro ii , a. dip. scienze terra palreontology professor univ. firenze italian delegate at inqua glq bassett, m. g. dept. of geology professor (univ. of wales, cardiff) national museum of wales, ics vice chairman cardiff chairman uk commission on stratigraphy carobene, l. • dip. scienze terra geology professor univ. genova glq carrozzini , b. dip. geomineralogico post-doc univ. bari castradori d. agip s.p.a. stratigrapher at agip (rapporteur) lab. bolgiano ciaranfi, n. * dip. geol. geof. geology professor (workshop organizer) univ. bari glq gita, m. b. * dip. scienze terra geology professor (workshop convener) univ. milano sns chairman cis chairman glq chairman colalongo, m. l. dip. scienze geol. palreontology professor univ. bologna glq dai pra, g. * enea-amb/saf/ter enea researcher casaccia, roma glq d'alessandro, a. dip. geol. geof. palreoecology professor (workshop organizer) univ. bari di stefano, e. dip. geol. geodesia researcher univ. palermo odp laccarino, s. * 1st. geologia micropalreontology professor univ. parma sns voting member, odp maiorano, p. dip. geol. geof. doctoral student univ. bari marino, m. dip. geol. geo!. post-doc (workshop organizer) univ. bari mazanti, r. * cnr-centro geologia cnr researcher dinamica e strutturale dell'appennino pasini, g. cnr-geol. marina cnr researcher bologna glq ratti , i. * facolta di scienze researcher; odp univ. chieti sns working group on pliocene time scale rio, d: dip. geologia micropalreontology professor univ. padova cis; glq sns voting member; odp sabato, l. dip. geol. geof. researcher (sedimentologist) (workshop organizer) univ. bari sprovieri , r. dip. geol. geodesia micropalreontology professor univ. palermo cis; glq sns corresponding member; odp vai, g. b. * dip. scienze geol. stratigraphy professor univ. bologna cis 'glq van couvering, j. micropaleontology press, editor-in-chief ( "micropaleontology") new york, usa phd geol. cambridge sns expert vernuccio, s. dip. geol. geodesia researcher univ. palermo cs: international commission on stratigraphy sns: subcommission on neogene stratigraphy of ics cis: commissione ltaliana di stratigrafia della societa geologica ltaliana glq: gruppo di lavoro sul quaternario della cis odp: ocean drilling program cnr: consiglio nazionale delle ricerche *: aiqua {associazione ltaliana per lo studio del quaternario) member middle and upper). this choice derives from the short time involved (less than two million years) , also following the advice of m. bassett. it also derives from the intent to induce scientists to the extensive and correct use of stage names. the calabrian stage covers the entire lower pleistocene, and extends from the gssp defined for the pliocene/pleistocene in the vrica section to the gssp to be de­ fined in the montalbano lonico section, the best candidate avail­ able for the middle pleistocene (see excursion, and further on). a redefinition of the stage, whose use is deeply root­ ed in the international literature but not consistent through­ out, is required (see notes by j . van couvering in the following pages; see also discussion in cita & castradori, in press, boll. soc. geol . ital.) . the possibility to further subdivide the lower pleis­ tocene or calabrian in three chronostratigraphic formal units, namely santernian, emilian and sicilian , was unan­ imously accepted. their rank is that of substages. a gssp for the emilian substage has been recently proposed by pasini and colalongo (1994), at sapropel layer "p" of the vrica section (see fig. 6). the second stage of the pleistocene, as here proposed, includes the sediments deposited in the time interval corre­ sponding to the "glacial pleistocene", predating the large tyrrhenian deglaciation. the name for this stage (ionian, from the ionian sea) and the basic criterion for the choice of its gssp were widely supported (practically by consen­ sus) by the polls and by the postal ballott, with the lower boundary close to the last (youngest) warm episode (iso­ topic stage 25) predating the beginning of the "glacial" pleistocene (isotopic stage 22). the latter alternative was considered , but discarded because a cold, regressive phase results inevitably in hiatuses on continental margins, and consequently is unfavourable for the base of a chrono­ stratigraphic unit. 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0 2.1 22 2.3 2.4 2.5 2.6 -~ :51 0 ., .. .. e .. .. ::i; 1 ~1 ""'" '""" __ ;t _______ _ z < z 0 > w a: z < w z u a: 0 w ii<i) < z w < :::, :::; 0 ...j u 0.. z en < z a: ~ cd ...j 'i < w ...j < z u < z a: ~ z < v) z w w ~ z z v) w w < ...j (!) u w 0 0 (!) w ...j z 0.. ,.; :$ 0.. 1: unnamed (tuantian7); 2: tyrrhonlan gssp to be proposed (taranto area, puglia) 685 in relation to the base of tho "strombus bed" gssp to be proposed (montalbano lonico, basilicata) close to isotopic stage 25 and/or small gephyrocapsajp. /acunosa nannofossil zonal boundary gssp to be proposed (montalbano lonico, basilicata or vrica, calabria) close to fo t. trucatulinoicfgs sxcelsa gssp proposed (vrica, calabria) paslni & colalongo, 1994 gssp wi.ciltd. (vrica, calabria) bassoll, 1985 agu irre & pasini, 1985 gssp proposed (s. nicola, sicily) rio et al., 1994 the montalbano lonico section has the potential to be a candidate section , as soon as properly documented, fig. 12 chronostratigraphic scheme resulting from the workshop. because of the continuous, undisturbed succession, rich lo schema cronostratigrafico risultante da/workshop. fossil content, expanded sequence. the problem concerning the late pleistocene is that the idea to extend the term tyrrhenian, deeply rooted in the international literature, up to the base of the holocene, was clearly rejected by the postal ballott. the name tarentian (after tarentum, the latin name of taranto), proposed by some, was not discussed enough, and is not supported at present by adequate sections. the tyrrhenian, limited to the "warm" isotopic stage 5, with an age range of approximately 130,000-80,000 y bp, should there­ after have the rank of substage. figura 13 schematical ly shows the extension of some classic plio-pleistocene sections from southern italy and adjacent areas. the figure caption contains some fundamental references, from the rich literature published in the latest few years. the last section to the right refers to the longest piston core investigated so far from the eastern mediterranean (calabrian ridge,' lonian sea) . this section (castradori, 1993; sanvoisin et al., 1993) is particularly interesting because it extends back to approximately 1 ma, contains three mag­ netic reversals, has isotopic stage 22 very well expressed (m. paterne, pars. communication, nov. 1994) and represents a perfect link with the upper part of the lower pleistocene, the entire middle pleistocene and the upper pleistocene sections from the gulf of taranto. proposal for a calabrian boundary stratotype (a contribution by: j. van couvering, micropaleontology press, amnh, new york) introduction the 1948 igc resolution, which has never been rescinded, states as follows : "the pliocene-pleistocene boundary should be based on changes in marine faunas ... ", "the lower pleistocene should include as its basal member in the type area the calabrian for686 mao 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 i.i 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3 2.4 2.5 2.6 ii-mg is.~ -~~ c/)~(o iii; .; c.. "' c: el .. g ~i "'2 ~(/) "' e "' >, :, "' zl :, "' (!) >a: <( z a: w i<( :, cj (/) cl) ·c: q) cl) hol cl) n f :::, cl) l......j 1 ""'" '""" '":("' z <( z 0 w z w 0 0 i(i) z w <( ::; ..j u 0.. z ;;; <( z a: <( id ::; :ij <( w ..j <( z 0 <( z a: w !z <( (i) sicily calabria bradanic trough ionian sea kc01b (piston core) (13;14) ·······•······•· · ·· ··---------············· · · --·-·· ··· · ······ . . montal­ bano i. (12) ··················· · ··-·-·-· -· ······ -----· -· ···· -slnga vrlca composite (8;9; (5;6;7) 10;11) --··· ······ ····· · · · ····· .... . . . .. . ... . . .. .. ... . . . . . capo rossello (1 ;2) ····•· ····· · ··· ··· ... ... . . ····· ·· ···· ·· ····· · · ·•·· san nicola (3;4) 1--f----<----+-+ · ··· -· . . ..... ·· -·-· · · · ·· ·· · · · · ···••··z w w <( z z (i) w w <( ..j (!) 0 w 0 0 (!) w ..j z 0.. f---··-· ...... ...... -·· · ··· ·· · · ···· · · ··· · ·· (.) <( ii: 1: unnamed (tarentlan?); 2: tyrrhenlan fig. 13 schematic stratigraphic extension of some classic plio-pleistocene sections from southern italy and adjacent seas. basic references are as follows: 1) cita & gartner (1973); 2) di stefano et al. (1993); 3) channell et al. (1992); 4) rio et al. (1994); 5) zijderweld et al. (1991 ); 6) hilgen (1987); 7) hilgen (1991); 8) selli et al. (1977); 9) agui rre & pasini (1985); 10) pasini & colalongo (1994); 11) see text for additional references; 12) ciaranfi et al. (1994); 13) castradori (1993); 14) sanvoisin et al. (1993). estensione stratigrafica schematica di alcune sezioni plio-pleistoceniche classiche dell 'ltalia meridionale e tratti di mare adiacenti. i principali riferimenti bibliografici sono: 1) gita & gartner (1973); 2) di stefano et al. (1993); 3) channell et al. (1992); 4) rio et al. (1994); 5) zijderweld et al. (1991); 6) hi/gen (1987); 7) hi/gen (1991); 8) se/ii et al. (1977); 9) aguirre & pasini (1985); 10) pasini & colalongo (1994); 11) see text for additional references; 12) ciaranfi et al. (1994); 13) castradori (1993); 14) sanvoisin et al. (1993). mation (marine) .. " and that "accor­ ding to evidence given this usage would place the boundary at the horizon of the first indication of cli­ matic deterioration in the italian neogene succession". from the above, we see that the criteria in order of increasing specificity are: i. change to colder climate at the end of the pl iocene; ii. change in marine faunas indicating a change to colder cli­ mate; iii. physical base of the ca­ labrian stage in its type area in italy, selected because it contains evidence of the change to colder climate. the pleistocene is a chrono­ stratigraphic unit, in the standard g lobal chronostratigraphic scale (9) . it is therefore not a "climatostra­ tigraphic" unit, or a biostratigraphic unit (8), or even a magnetostrati­ g raphic unit (14). chronostrati­ graphic units are defined in boundary-stratotypes, primarily the lower boundary (12) , which in the case of the global chronostrati­ g raphi c scale are denoted as gssp (7). the gcs is hierarchal (9), so the pleistocene series is defined by the base of its lowest constituent gcs stage (10) . point 1: the calabrian is the lowest stage in the pleistocene, per igc 1948 subcommission recom­ mendation (11 ). point 2: the usage of the calabrian as the lowest stage in the pleistocene is universally well established in the standard global chronostratigraphic scale (3). po int 3: the base of the calabrian, as presently defined at santa maria di catanzaro , does not coincide with the base of the pleistocene, as presently defined, and it does not adequately represent the calabrian stage as described by gignoux (5) (1). point 4: the section at vrica has been thoroughly described, analyzed and documented in a large number of studies (5, 13). point 5: the ratified gssp for the beginning of the pleistocene at vrica adequately represents the concept of lower calabrian in the sense of gignoux, as well as the customary and long standing practise in italy and the meaning of the 1948 london igc resolu(1) gignoux considered that all of the sections which he described were part ol a synthetic concept of the calabrian stage, and he refused on principle to designate a stratotype when requested by the igc subcommission (vai, pars.comm.). to use this name for an equivalent chronostratigraphic unit re­ quires that an appropriate stage stratotype is designated which exemplifies the fundamental characteristics (fauna, age, lithology) of gignoux' synthesis, and that an appropriate boundary-stratotype is designated which exemplifies the oldest part of the synthesis. neither of these considerations has been met adequately to this date. 687 tion, in regard to faunal and sedimentological evidence of a change to colder cl imate. it has been shown by igcp 41, "n/q boundary", that this change is synchronous with evidence for the first typical pleistocene glacial cycle regionally and worldwide as intended by the 1948 london igc subcommission in making its recommendation (10, 13). conclusion the base of marker bed "e" in component section b at vrica should be recognized henceforth as the lower boundary-stratotype of the calabrian stage, according to the 1948 igc resolution which designated calabrian as the lowest stage of the pleistocene (1,2, 12). the strata above this level to the top of the vrica section as described in the referenced literature should be recognized hen­ ceforth as the boundary-stratotype section of the calabrian stage (13). quotations (1 ). "there are stratigraphic situations where hard and fast rules cannot be applied and that common sense may indicate what will best promote clarity, understanding and progress." (p. 4) (2). "the revision and redefinition of a previously proposed and named unit requires a statement of intent to revise the unit, the rea­ sons for doing so, and a discussion of the history of the unit-author, original reference, previous treatment. if necessary, it should include a comprehensive description of the unit and designation of a new type section or type locality (or revision of the old one). the revision of a unit, to be valid, must be published in a recognized scientific medium." (p. 17) (3) . re priority, in regard to new names (e.g. santernian): (p . 23) "priority in publication of a properly proposed, named and defined unit should be respected ... the critical factors should be the usefulness of the unit, the adequacy of its description, freedom from ambiguity, and suitability for widespread publication." (p. 23) (4). re priority, in regard to earlier, obscure names: "priority alone does not justify displacing a well-established name by one not well known or only occasionally used; nor should an inadequately established (earlier obscure name) be preserved merely for the sake of priority." (p. 23) (5) . "revision or redefinition of previously established stratigraphic units. revision or redefinition of an adequately established unit without changing its name requires as much justification and the same kind of information as for proposing a new unit. ... redefinition may also become desirable because of.. .. errors in an earlier work .... changes in major chronostratigraphic units of international scope should be made only after consultation with appropriate stratigraphic organizations." (p . 24) (6). "b. parastratotype. a supplementary stratotype used by the original author. c. lectostratotype. a stratotype for a previously described stratigraphic unit selected later in the absence of an adequately described original stratotype." (p. 28) note (1 ). gignoux did not designated a stratotype. selli's was the first, thus the holostratotype, not the lectostratotype. (7). "global boundary stratotype section and point (gssp) is the term proposed for these standard boundary-stratotypes of units of the global chronostratigraphic scale (cowie et al 1986)."(p. 29. see references 12, 13) (8). "biostratigraphic units (biozones) are bodies of rock strata that are defined or characterized on the basis of their contained fossils." (p.53) (9). "the named units composing each rank in this standard global chronostratigraphic scale encompass, as a whole, the entire stra­ tigraphic sequence, without gaps and without overlaps." (p. 78} (1 0). "the selection of the boundaries of the stages of the standard global chronostratigraphic scale deserves particular emphasis because such boundaries serve to define not only the stages but also chronostratigraphic units of higher rank such as series and systems of which stages are components." (p. 79) (11 ). "series are defined by boundary stratotypes. if a series has been completely divided into stages its boundaries should be the lower boundary of its oldest stage and the upper boundary of its youngest stage, or the lower boundary of the lowermost stage in the overlying series. if stage subdivisions are not available, the series may be defined independently by its own boundary-stra­ totypes." (p. 80) (12). "the definition of chronostratigraphic units is best accomplished .... by the selection of boundary-stratotypes of their lower bound­ aries. these boundary-stratotypes are specific and representative sequences of strata in specific geographic localities that con­ tain unique and specific points that are the record of unique instants of geologic time." (p. 90) (13). "the selection of the boundary-stratotypes of chronostratigraphic units of the global chronostratigraphic scale, where possible, should take account of historical priority and usage and should approximate the traditional boundaries. to insure its acceptance and use over wide areas, preferably worlwide , a boundary-stratotype should be selected to contain as many specific good marker horizons or other features favourable for long-distance time correlation (chronocorrelation) as possible. examples are significant biohorizons characterized by distinctive marine, cosmopolitan fossils; magnetic polarity reversals; and stratigraphic intervals favourable for accurate numerical dating." (p. 91) 688 ► i ~~ w ~~ ~ w > ~ ~ ~ ~d~ ~ f ~ 00 ! o, i 0.2 ~ 031 04~ (/) w .j .j ll. m 'o 'o e sam paolo 1 lou!111111111un1 1ilh"elo,hugro10,i• triversa m111111lf1ynl piemonte 11111 cj c=j imola lot1i r1 1■m1i f1un1 ofsantern0v1lley positive paleomagneti sm reversed paleomagnetism marine sediments 1111111111 inna romagna liguria vi llafranca d'a. lmola-faenza sarzana toscana l. valdarno [ij ~ samia barbara c11lelnmolltis1blli011i l«1l111111lllm1 @ paleomagnetism still to be measured interval wrongly attributed to the "galeriano" position of the levels containing man1mal faunas c1p ilone loc1t11m11ll1u11 toscana western u. valdarno umbria umbria tiber valley marche apennines rn m lu rn w er: uj ::::; _j ~ 'z <c en [ 1-:z 0 ::a. ::::; _j uj cl :z 0 ~ <c en a:: w ~ a:: ifig. 14 correlation of continental fossiliferous successions from northern and central italy and the paleomagnetic stratigraphy (p. ambrosetti, unpubli­ shed, 1994). the columnar logs indicate the results of paleomagnetic investigations, when available. question marks indicate questionable data. corre/azione fra successioni continentali fossilifere dell'ltalia settentrionale e centrale e la stratigrafia pa/eomagnetica (p. ambrosetti, inedito, 1994). le stratigrafie mostrano i risultati degli studi paleomagnetici; i "?" indicano che i dati possono non essere certi. 689 (14). " ... the body of rock strata lying between magnetic-polarity-reversal horizons .... constitutes a polarity unit containing everywhere strata representing essentially, but not exactly, the same time span. such units may approximate chronostratigraphic units, but, strictly speaking, they are not chronostratigraphic units because they are defined primarily not by the record of time but by a spe­ cific physical property, a change of the polarity of remanent magnetization, which is not instantaneous." (p. 101 ). major breaks in continental faunal successions in europe and the need of high resolution datings for the pleistocene (a contribution by a. azzaroli, earth sciences dept. , university of florence) analysis of faunal successions of the plio-pleistocene is linked with the problem of correlation with marine sequences and cali­ bration with the geomagnetic scale. only few sites have been reliably calibrated so far. the very rich fauna of the maar of seneze, french central massif, has been calibrated to the early matuyama chron, in a reversed polarity interval between a short normal episcx:le (reunion) and the olduvai event. the age of the tegelen fauna of the netherlands, less rich but of similar composition, is comprised between the olduvai event and the underlying reversed polarity interval. only one late villafranchian (early pleistocene) fauna has been calibrated with the geomagnetic scale: the matassino local fauna in the upper valdarno lies about 5 m above the end of the olduvai event (torre et al., 1993). faunal change at the pliocene-pleistocene transition was marked by extinctions and new appearances of species but was not sharp, and the early pleistocene fauna still keeps close links with the faunas of the late pliocene. evidence presently available is not adequate to pinpoint the faunal change in the chronological scale, the more so as appearances of new elements in the faunas were not sudden, and some characteristic early pleistocene species occur sporadically in late pliocene levels: sus strozzii, leptobos etruscus. a faunal revolution of much greater moment took place later, at the villafranchian-galerian transition. many species became extinct and were replaced by new species, either immigrants or more derived descendants of late villafranchian species. the faunal assemblage changed its character: it lost its pliocene affinities and assumed a modern aspect. the present faunal assemblage assumed its fundamental outlines at this time. new types of adaptation developed: the heavy bovids bison, bos, ovibos, the recently extinct giant deer, megaloceros, megaceroides, cervalces latifrons. this revolution was not sudden, and localities with mixed faunal assemblages, in which late villafranchian holdovers are associated with modern elements, have been discovered at several sites and are under active study. still , there are reasons to believe that the revolution was rapid; moreover, it appears that it was not contemporary over eurasia. the revolution started in ne siberia with the first lemmings and muskoxen, somewhere around 1.2 ma and spread westwards. in germany, the main fauna of mosbach (graues mosbach), a typically galerian assemblage, dates from the early brunhes; an older level, with villafranchian elements associated with galerian immigrants (graues mosbach), dates from the jaramillo episode. vertebrate paleontologists and students of continental stratigraphy feel the need of a high resolution chronology in order to analyze cause-to-effect relationships in faunal events and in changes in climate and vegetation . the marine stratigraphic scale offers good prospects for a high resolution chronology. a boundary between early and middle pleistocene defined in a marine sequence on the basis of biological and climatic events may become a useful term of reference for detailed datings of continental formations and fossils , provided its age is not too far removed from the dates of the major revolutions on the continents. bibliografia aguirre e. & pasini g., 1985 the pliocene-pleistocene boundary. episodes, 8, 116-120. bassett m.g., 1985 towards a "common language" in stratigraphy. episodes, 8, 87-92. castradori d., 1993 calcareous nannofossi/ biostratigraphy and biochronology in eastern mediterranean deep-sea cores. riv. it. paleont. strat., 99, 107-126. channell j., di stefano e. & sprovieri r., 1992 calcareous plankton biostratigraphy, magnetostratigraphy and paleoclimatic history of the plio-pleistocene monte san nicola section (southern sicily). boll. soc. paleont. it. , 31 , 351 -382. ciaranfi n., d'alessandro a. , marino m. & sabato l., 1994 la successione argillosa infra e mediopleistocenica def/a parte sudocci­ dentale def/a fossa bradanica: la sezione di montalbano lonico in basilicata. in: guida a/le escursioni, congresso soc. geol. it., bari (1994), quaderni bibi. prov. matera, 15, 117-156. cita m.b. & gartner s., 1973 studi sul pliocene e gli strati di passaggio dal miocene al pliocene. iv. the stratotype zanclean. foraminiferal and nannofossil biostratigraphy. riv. it. paleont. strat. , 79, 503-558. cita m.b., rio d. & sprovieri r., in stampa the pliocene series: chronology of the type mediterranean record and standard 690 chronostratigraphy. wrenn et al. (eds.), aasp sp. vol. (baton rouge) . colalongo m.l. , pasini g. & sartoni s., 1980 neogene-quaternario e definizione def relativo stratotipo nella sezione vrica (calabria). paleontol. stratigr. ed evoluz., quad., 1, 91 -94. colalongo m.l., pasini g. & sartoni s., 1981 remarks on the neogene/quaternary boundary and the vrica section (calabria, italy). boll. soc. paleont. it., 20, 99-120. dai pra g., 1982 the late pleistocene marine deposits of torre castiglione (southern italy). geogr. fis. dinam. quat., 5, 115-119. dai pra g. & hearty p.j., 1988 i live/ii marini pleistocenici de/ go/to di taranto. sintesi geocronostratigrafica e tettonica. mem. soc. geol. it., 41, 637-644. dai pra g. & hearty p.j., 1989 variazioni de/ live/lo def mare sulla costa ionica salentina durante l'olocene. epimerizzazione dell'iso­ /eucina in helix sp. mem. soc. geol. it., 42, 311-320. di stefano e., sprovieri r. & caruso a., 1993 high resolution biochrono/ogy in the monte narbone formation of the capo rosse/lo section and the mediterranean first occurrence ofgloborotalia truncatul inoides. riv. it. paleont. strat., 99, 357-370. doderlein p., 1872 note illustrative de/la carta geologica de/ modenese e de/ reggiano. memoria 111, 74 pp. gignoux m., 1913 les formations marines pliocenes et quaternaires de l'ltalie du sud et de la sici/e. ann. univ. lyon, n.s., 1, 24-693. hearty p.j. & dai pra g., 1992 the age and stratigraphy of middle pleistocene and younger deposits along the gulf of taranto (southeast italy). j. coastal res., 8, 882-905. pasini g. & colalongo m.l., 1994 proposal for the erection of the santernian/emilian boundary-stratotype (lower pleistocene) and new data on the pliocene/pleistocene boundary-stratotype. boll. soc. paleont. it., 33, 101-120. pelosio g., ratti s. & rio d., 1980 the plio-p/eistocene boundary controversy. status in 1979 at the light of in ternational stratigraphic guide. in: f. petrucci & r. cavazzini (eds.), volume dedicate a sergio venzo, 131-140. ratti i. & rio d., 1980 nannoplancton calcareo de/ pliocene superiore-pleistocene inferiore de/la serie de/ fiume santerno. paleontol. stratigr. ed evoluz., quad., 1, 187-195. rio d., 1982 the fossil distribution of coccolithophore genus gephyrocapsa kamptner and related plio-pleistocene chronostrati­ graphic problems. lnit. rep. dsdp, 68, 325-343. rio d., ratti i. & villa g., 1990 pliocene-pleistocene calcareous nannofossils distribution patterns in the western mediterranean. proc. odp, sci. results, 107, 513-533. rio d., sprovieri r. & thunell r., 1991 pliocene lower pleistocene chronostratigraphy: a re-evaluation of mediterranean type sec­ tions. geol. soc. am. bull., 103, 1049-1058. rio d., sprovieri r. & di stefano e., 1994 the ge/asian stage: a proposal of a new chronostratigraphic unit of the pliocene series. riv. it. paleont. strat., 100, 103-124. ruddiman w.f., raymo m.e., martinson d.g ., clement b.m. & backman j., 1989 pleistocene evolution: northern hemisphere ice sheets and north atlantic ocean. paleoceanography, 4, 353-412. ruggieri g. & sprovieri r., 1976 ricerche sul siciliano di palermo: le argille de/ fiume oreto. boll. soc. geol. it., 94, 1613-1622. ruggieri g., unti a., unti m. & moroni m.a., 1977 la ca/carenite di marsala (pleistocene inferiore) e i terreni contermini. boll. soc. geol. it., 94, 1623-1657. ruggieri g. & sprovieri r., 1979 selinuntiano, nuovo superpiano per ii pleistocene inferiore. boll. soc. geol. ital., 96, 797-802. ruggieri g. & sprovieri r., 1983 recenti progressi nella stratigrafia de/ pleistocene inferiore. boll. soc. paleont. it., 22, 315-321. ruggieri g., buccheri g., greco a. & sprovieri r., 1976 un affioramento di siciliano nel quadro de/la revisione de/la stratigrafia de/ pleistocene inferiore. boll . soc. geol. it., 94, 889-914. ruggieri g., rio d. & sprovieri r., 1984 remarks on the chronostratigraphic classification of lower pleistocene. boll. soc. geol. it., 103, 251 -259. salvador a. (ed.), 1994 international stratigraphic guide. a guide to stratigraphic classification, terminology, and procedure. second edition, boulder, co, the geol. soc. of america. sanvoisin r., d'onofrio s., lucchi r., violanti d. & castradori d., 1993 1 ma paleoclimatic record,from the eastern mediterranean. marflux project: first results of a micropa/eontologica/ and sedimentologica/ investigation of a long piston core from the calabrian ridge. ii quaternario, 6, 169-188. selli r., 1971 calabrian. giorn. geologia, s.2, 37, 55-64. selli r., accorsi c.a., bandini mazzanti m., bertolani marchetti d., bigazzi g., bonadonna f.p., borsetti a.m., cati f., colalongo m.l., d'onofrio s., landini w., menesini e., mezzetti r., pasini g., savelli c. & tampieri r., 1977 the vrica section (calabria, italy). a potential neogene/quaternary boundary stratotype. giorn. geol. ser.2, 42, 181-204. tauxe l., opdyke n.d., pasini g. & elmi c., 1983 age of the plio-pleistocene boundary in the vrica section, southern italy. nature, 304, 125-129. torre d., albianelli a., azzaroli a., ficcarelli g., magi m. & napoleone g., 1993 paleomagnetic calibration of late villafranchian mammal faunas from the upper va/darno, central italy. mem. soc. geol. it., 49, 335-344. vergnaud-grazzini c., capotondi l. & lourens l., 1994 a refined pliocene to early pleistocene chronostratigraphic frame at odp 691 hole 653a (west mediterranean). mar. geol. , 117, 329-349. verhallen p.j.j.m., 1991 late pleistocene to early pleistocene mediterranean mud-dwelling foraminifera; infuence of a changing environment of community structure and evolution. utrecht microplaeont. bull., 40, 1-219. zijderveld j.d.a., hilgen f.j., langereis c.g., verhallen p.j.j .m. & zachariasse w.j ., 1991 integrated magnetostratigraphy and bio­ stratigraphy of the upper pliocene-lower pleistocene from the monte singa and crotone areas in calabria (italy). earth and planet. science letters. 107. 697-714. taranto 2-1 taranto 2-2 taranto 2-3 taranto 1-4 taranto 1-5 taranto 2-6 taranto 1-7 taranto 1-8 taranto 1-9 taranto 2-10 taranto 1-11 taranto 2-12 taranto 1-13 taranto 1-14 taranto 2-15 ustica is a small island in the southern tyrrhenian sea (fig. 1), with a long history dating back to the neolithic, in the 6th millennium before common era (bce). its historical trajectory closely follows that of sicily, particularly palermo, located only about 30 nautical miles away. during the middle bronze age (mba), ustica was densely inhabited. the largest settlement of that period was villaggio dei faraglioni, which, after about two centuries of intense activity, was suddenly abandoned around 1250-1200 bce (spatafora, 2009; spatafora & mannino, 2008). thereafter, the island remained uninhabited for a long time, until a new settlement was established at rocca della falconiera in the third century bce. this prolonged phase of abandonment is difficult to explain, as it coincides with the phoenician and greek colonization of sicily, despite ustica's strategic location along trade routes connecting the etruscans and sardinia (spatafora & mannino, 2008). several hypotheses have been put forward to explain ustica’s abandonment during the late bronze age, primarily attributing it to a sudden natural catastrophe, such as an earthquake, or an unexpected invasion and subsequent looting (spatafora & mannino, 2008). however, the catastrophe hypothesis is contradicted by archaeological evidence, which shows no signs of significant structural damage to the village’s defensive walls and huts, no massive destruction of pottery, and no evidence of extensive fire (foresta martin & furlani, 2021). available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 38 (1), 2025, 63-78 https://doi.org/10.26382/amq.2025.04 1. introduction there are numerous reports on the significant influence of climate change on the rise and fall of civilizations. for instance, the justinianic plague, which marks the decline of the roman empire, has been linked to a prolonged period of climate deterioration (zonneveld et al., 2024). similarly, the rise of the roman empire may have been facilitated by a sustained climatic optimum, characterized by the highest sea surface temperatures in the mediterranean over the past 2,000 years (margaritelli et al., 2019), before the anthropogenic co2 emission. the mediterranean region is particularly sensitive to climate fluctuations. ongoing global warming is progressing at an accelerated rate in the mediterranean sea, approximately 20% faster than the global ocean average (medecc, 2021; marriner et al., 2022). even past natural climatic oscillations were significantly amplified, as seen during the dansgaard-oeschger events of the last glacial period (incarbona et al., 2013; martrat et al., 2004; sprovieri et al., 2012). moreover, the mediterranean is the cradle of western civilization, as well as, at least in part, north african, near eastern, and middle eastern civilizations. ancient egyptians, greeks, and romans flourished in this region, and the distribution of unesco world heritage sites vividly reflects their highest density along mediterranean coasts. late bronze age collapse at ustica island (sicily italy): the drought hypothesis franco foresta martin1,2, alessandro incarbona3,4 1istituto nazionale di geofisica e vulcanologia, sezione di palermo, italy. 2laboratorio museo di scienze della terra isola di ustica, palermo, italy. 3università degli studi di palermo, dipartimento di scienze della terra e del mare, palermo, italy. 4national biodiversity future center (nbfc), palermo, italy. corresponding author: alessandro incarbona <alessandro.incarbona@unipa.it> abstract: ustica is a small island in the southern tyrrhenian sea. during the middle bronze age, hundreds of inhabitants were primarily concentrated in the fortified citadel of villaggio dei faraglioni. the site was suddenly abandoned between 1250 and 1200 bce, and the entire island remained uninhabited for eight centuries. several hypotheses have been put forward to explain this abandonment, including the occurrence of a natural catastrophe or an unexpected hostile invasion. here, we explore an alternative explanation: the impact of climate change, with a particular focus on drought. ustica remained uninhabited during a period of global and regional climatic deterioration, coinciding with sunspot minimum and stratospheric sulfate injection, from unknown explosive volcanic eruptions. both northern and southern offshore areas of sicily recorded prolonged and strengthened northerly atmospheric activity, which cooled sea surface temperatures and enhanced the water column vertical mixing. stable isotope data from speleothems in northern spain and central italy indicate pronounced drought episodes following ustica's abandonment at 3.15 ka bp, coinciding with a predominantly positive north atlantic oscillation phase. locally, reduced precipitation levels are evidenced by significant dryness in sicily between 3.2 and 3.0 ka bp, as reflected in lake level fluctuations. the severe drought affecting sicily and ustica between 3.2 and 3.0 ka bp appears to be the culmination of a broader aridification trend that had been ongoing at both global and regional scales since the 4.2 ka bp event. water shortages may have led to sanitary issues, crop failures, and famine. though speculative, our hypothesis provides a more plausible explanation for the well-preserved pottery and defensive walls at villaggio dei faraglioni, than scenarios involving natural catastrophes, invasions, or looting. keywords: central mediterranean; societal impact of climate change; event 3.2 ka; archaeology; paleoclimate. in this study, we explore an alternative explanation: the impact of climate change, with a particular focus on drought. this hypothesis is not entirely new (foresta martin & furlani, 2021), but here it is reassessed considering paleoclimatic advances made in the region over the past quarter-century. this review evaluates recent paleoclimatic proxy data from the middle and late holocene to support a broad range of archaeological research and applications. 2. study area 2.1. ustica geology, archaeology and history ustica is a deep-sea volcano formed by the activity of a left-transtensional fault system, resulting from the anticlockwise rotation of the italian peninsula and the opening of the tyrrhenian basin, likely during the earliest middle pleistocene (de vita et al., 1995, 1998). after several hundred thousand years of underwater volcanic activity, during which a high seamount was built, the island emerged approximately 500 ka ago. volcanic activity continued with a complex sequence of subaerial eruptions, including effusive, strombolian, and explosive phases, and ended around 130 ka with a hydromagmatic eruption that formed the monte falconiera crater (de vita & foresta martin, 2017). glacio-eustatic sea-level fluctuations led to the formation of several marine terraces dated to the middle and late pleistocene (de vita & orsi, 1994; buccheri et al., 2014; de vita & foresta martin, 2017), (fig.2). the first settlements on the island were established during the middle neolithic, between the 6th and 5th millennia bce (mannino, 1998; speciale et al., 2021). more abundant and significant archaeological remains from the eneolithic, early bronze age and middle bronze age have been identified at different sites, testifying to the island's continuous human presence during prehistory (foresta martin & furlani, 2021; spatafora & mannino, 2008). the middle bronze age (1400-1200 bce) marks the peak of population density on the island and the foundation of the fortified villaggio dei faraglioni on the northern cusp of the island. the rationality of the urban planning of the village, the fortification system and the diverse and sophisticated pottery recovered, suggests the development of a complex socio-economic structure within a prosperous community (spatafora & mannino, 2008; russolillo et al., 2024). around 1250-1200 bce villaggio dei faraglioni was suddenly abandoned, and the entire island remained uninhabited for approximately 800 years (spatafora & mannino, 2008; foresta martin & furlani, 2021; russolillo et al., 2024). a new settlement was established in ustica on the top of the falconiera crater (fig. 2) during the hellenistic-roman period, around the 3rd century bce, likely in the time of the first punic war (spatafora & mannino, 2008; foresta martin & furlani, 2021). throughout ustica’s prehistory, from the neolithic to the middle bronze age, water supply was a challenge due to the scarcity of natural springs. water was primarily obtained from dripping sources in sea caves and rain 64 f. foresta martin, a. incarbona fig. 1 bathymetric map of the western-central mediterranean sea (generated with ocean data view 4.0, schlitzer, 2025) showing the location of ustica island (red rectangle). black arrows indicate the modified atlantic water (maw) path (modified from pinardi & masetti, 2000). black dots mark the locations of sedimentary cores from the tyrrhenian sea and the sicily channel (sbaffi et al., 2001; incarbona et al., 2008). circles 1 and 2 indicate the locations of corchia and asiul caves, respectively (smith et al., 2016; isola et al., 2019). half of the 18th century, a new community, composed of settlers from lipari, established a permanent presence on ustica at the behest of the bourbon government, founding the present-day town of ustica near cala santa maria (fig. 2), on its southeastern coast (barraco picone, 2007). throughout the 19th and 20th centuries the growing need for drinking water was supplied by tank ships, whereas today it is provided by a desalination plant. 2.2. mediterranean climate framework both midand low-latitude climate systems exert a seasonally variable influence on the mediterranean region. in summer, subtropical high-pressure fields establish stable, dry and warm conditions across the mediterranean (lionello, 2012). in winter, the north african subtropical high weakens and shifts southward, allowing cold polar/continental air outbreaks and rainy westerlies to penetrate the mediterranean basin (lionello, 2012; rohling et al., 2015). the north atlantic oscillation (nao) is a mode of water harvesting (foresta martin & furlani, 2021). sea caves may have provided up to 100 liters of dripping water per day (foresta martin & furlani, 2021). rainwater, which also fed the cave drippings, is more difficult to be quantified as it depends on seasonal and decadal cycles and regional atmospheric patterns. following ustica’s reoccupation in the hellenistic-roman period, a far more advanced system for rainwater collection was developed, including an extensive network of cisterns for water storage, similar to those found in other mediterranean settings (yannopoulos et al., 2016). the island remained again inhabited since the 13th century, during the middle ages, except for a small community with an agricultural and pastoral vocation was established around a cistercian monastery, in the case vecchie area (fig. 2). this settlement, however, was short-lived due to the growing frequency of incursions by north african pirates, which compelled the inhabitants of ustica to abandon the island, rendered increasingly unsafe by raids and abductions (barraco picone, 2007). following almost five centuries of abandonment, in the second 65 late bronze age collapse at ustica island (sicily-italy): the drought hypothesis fig. 2 simplified geomorphological map of ustica island. the asterisks indicate the main archaeological settlements discovered so far. the villaggio dei faraglioni mba site is in the coastal northern cusp of the island. modified from foresta martin & furlani, 2021. decadal atmospheric variability that largely controls precipitation in the european-mediterranean region. during positive nao phases, when the pressure gradient between the azores high and the icelandic low is stronger, wet westerlies bring winter precipitation to central and northern europe, while southern europe and north africa experience drought. this pattern reverses during negative nao phases (hurrell, 1995; wanner et al., 2001). persistent positive or negative nao phases have been identified over longer timescales, based on proxy data, for preindustrial climate and societal changes such as the roman period, the medieval climate anomaly, and the little ice age (luterbacher et al., 2001, 2004; trouet et al., 2009), as well as for the holocene (olsen et al., 2012; smith et al., 2016). although the mediterranean sea’s thermohaline circulation does not significantly impact the global climate system, the outflow of salty intermediate-depth water through the strait of gibraltar may have enhanced water density and contributed to north atlantic deep water formation during heinrich stadials, potentially aiding in the resumption of the atlantic meridional overturning circulation (rogerson, 2012; rogerson et al., 2010). nonetheless, palaeoceanographic data from deep mediterranean sea sediments provide valuable insights into past climate regimes and events. among other indicators, variations in sea surface temperature, calcareous plankton productivity and seafloor ventilation reflect water column dynamics associated with different atmospheric patterns. the paleoclimatic proxy data relevant to this study are presented in detail in the next section (3. materials and datasets). 3. materials and datasets 3.1. the faraglioni village chronology since the early 1970s, thirteen excavation campaigns have been conducted at the faraglioni village under the direction of three different archaeologists: four by giovanni mannino between 1974 and 1980; four by robert ross holloway between 1990 and 1999; and a further five by francesca spatafora from 2000 to 2018 (spatafora, 2023; spatafora personal communication, 2025). the extensive body of scientific literature resulting from these excavations broadly agrees in identifying a settlement that persisted for approximately two or three centuries, from 1450-1400 bce to 1200-1150 bce. this chronology is supported by a rich and diverse assemblage of tableware and storage pottery, whose shapes and decorative styles align with the thapsos-milazzese cultural facies of eastern sicilian mba. “thapsos” refers to the eponymous site on the magnisi peninsula near syracuse, while “milazzese” relates to the homonymous village on panarea in the aeolian islands (spatafora, 2016; spatafora & mannino, 2008). among the most characteristic ceramics of this cultural tradition are high-footed cups (which in ustica feature a ribbed stylistic variant), ‘teglie’ with internal handles, vases and amphorae of different sizes (figs 3 and 4). thapsos-milazzese facies can be securely dated due to their close association with imported mycenaean pottery from the aegean, for which robust radiocarbon absolute chronology have been established (alberti, 2013 and references therein). interestingly, in ustica the presence of unequivocal mycenaean imports is limited to a single fragment of a stirrup jar (fig. 5) and a few glass beads recovered during holloway’s excavations (holloway, 1995). this scarcity has sparked debate among archaeologists as to whether it reflects the absence of mycenaean materials in the areas excavated thus far, or a genuine lack of trade connections between ustica and the aegean world. holloway (1995) submitted eight samples from the faraglioni village to the laboratory of isotopic geochemistry at the university of arizona in tucson for radiocarbon (¹⁴c) analysis, whose results are shown in table 1. due to the advances in the calibration curves over the last 30 years, we carried out a new calibration of holloway’s radiocarbon datings by oxcal v4.4.4, with the atmospheric data by reimer et al. (2020). no significant mismatch exists between the two different calibrations (table 1): most of results overlaps the traditional archaeological chronology, with a settlement which persisted from 1450-1400 bce to 1200-1150 bce; two calibrated ages fall outside the expected archaeological timeframe. different authors complain lacking information on examined materials and suggest that the site may have been shortly re-occupied (leighton, 2004; spatafora, 2009); one calibrated age indicate a much 66 fig. 3 the main vascular forms of the abundant pottery recovered during the excavations at the villaggio dei faraglioni in ustica. all stylistically recall the pottery of the thapsosmilazzese facies, typical of the mba, but with some stylistic variants exclusive to ustica. 1: "teglia" (large flat plan), with internal handles. 2, 3,4: medium-fine ware vessel with two handles. 5: jug with one handle. 6: cup with high trumpet foot and double handle. 7: cup with short trumpet foot and double handle. 8, 9: small two-handled amphorae. modified from mannino, 1982. f. foresta martin, a. incarbona and the holocene, when northern hemisphere ice sheets expanded, leading to their destabilization and the subsequent release of massive numbers of icebergs (bond et al., 1997, 2001; hemming, 2004). earlier occupation of the site. it may be an outlier and in any case its meaning is beyond the aim of the present paper that deals with the late bronze age abandonment. even the chronological development of the urban plan of the faraglioni village towards a more orderly and rational layout, characterized by a main road axis flanked by a sequence of huts and courtyards, with secondary streets arranged orthogonally, provides an indication, albeit indirect and approximate, of its construction period. it is the shared view of the archaeologists who have worked on the site that this more advanced layout, stratigraphically datable to the final phase of the village’s existence, is connected to contemporary urban planning practices in eastern sicily, notably at thapsos, which were themselves influenced by mycenaean housing culture (fig. 6) (holloway, 1995; spatafora & mannino, 2008). 3.2. holocene climatic cycles in our study, archaeological and demographic data were converted from bce or ce to bp, where year 0 corresponds to 1950 ce. the holocene, the current interglacial period that began 11.7 ka ago, was long considered climatically stable, characterized by a long-term cooling trend, with only one major climatic deterioration event at 8.2 ka (alley et al., 1997). bond et al. (1997, 2001) were the first to identify a complete sequence of holocene suborbital fluctuations, known as bond cycles, based on peaks of ice-rafted detritus (ird) deposited in the highlatitude north atlantic. these cycles exhibit the same 1,470-year periodicity as the last glacial dansgaard-oeschger events. however, unlike dansgaard-oeschger events, episodes of atlantic meridional overturning circulation (amoc) slowdown do not perfectly align with bond cycles, nor does solar variability provide a definitive explanation (bond et al., 2001; oppo et al., 2003). bond cycles closely resemble rapid climatic changes (rccs), a series of climatic anomalies recorded at more than 50 sites worldwide (mayewski et al., 2004). rather than being strictly cooling events, rccs represent local climatic anomalies, such as droughts, intensified atmospheric circulation, or glacier advances (mayewski et al., 2004). focusing on the mid-tolate holocene, which is particularly relevant for archaeological and historical studies, a wellestablished link exists between rccs and sunspot minima. these minima were often accompanied by explosive volcanic eruptions that released sulfur, which subsequently transformed into highly reflective sulfate aerosols in the atmosphere (maasch et al., 2005; mcgregor et al., 2015). the following section introduces the paleoclimatic proxy data presented in figs 7 and 8 to ensure a smooth discussion. all data are shown according to their original age models, with dating uncertainties generally within a few hundred years. ird peaks in the north atlantic were deposited during the coldest phases of both the last glacial period 67 late bronze age collapse at ustica island (sicily-italy): the drought hypothesis fig. 4 pottery recovered during excavations at the villaggio dei faraglioni, on display at the 'seminara' archaeological museum in ustica. from left, top: cups on a high foot; big pot supported by two 'alari'; large containers for storing grain, cereals and oil. photo by ffm. fig. 5 the only mycenaean vase fragment found so far at the faraglioni village of ustica. the find dates back to the excavations carried out by holloway in the first half of the 1990s. from holloway, 1995. sea surface temperature (sst) estimates are derived from different ‘paleothermometers,’ i.e., various analytical techniques. among fossil organic compounds, alkenones are the most commonly used, while in inorganic geochemistry, the mg/ca ratio in calcite shells is the primary method. solar magnetic activity decreases during periods of low sunspot numbers, leading to an increased flux of galactic cosmic rays in the earth's outer atmosphere, which enhances the production of ¹⁴c and ¹⁰be (finkel & nishiizumi, 1997; hughen et al., 2000; stuiver et al., 1998). the total solar irradiance (tsi, in w/m²) reconstruction used in this study is based on measurements of cosmogenic ¹⁰be in ice cores (steinhilber et al., 2009). net primary productivity estimates in the sicily channel are based on a regional calibration between the percentage values of the coccolithophore species florisphaera profunda in 43 surface sediment samples and ten years of net primary production data at the same sites, derived from satellite imagery. chlorophyll estimates obtained via remote sensing were converted into milligrams of carbon per square meter per day (mgc m ² d ¹) using the standard algorithm of the vertically generalized production model (behrenfeld & falkowski, 1997). the regression equation follows a logarithmic function, with r=0.84 (incarbona et al., 2008). high concentrations of non-sea-salt k + in greenland ice cores serve as a proxy for intensified atmospheric circulation in the northern hemisphere and an expanded polar vortex (mayewski et al., 1997; meeker & mayewski, 2002). local cave investigations have established a link between oxygen isotope variations in speleothems and regional rainfall levels. light and heavy δ¹⁸o values correspond to wet and dry conditions, respectively. decadal and centennial-scale variations in the cueva de asiul speleothem moisture record align with european reconstructions of nao variability over the past 2.5 kyr (smith et al., 2016). 4. discussion the centuries-old abandonment phase of ustica island, occurring between 3.2-3.15 and 2.25 ka bp, aligns perfectly with the bond cycle b2, a rapid climate change (rcc) interval, and the mediterranean sea surface temperature (sst) cooling event known as the 3.2 ka event (bond et al., 1997, 2001; marriner et al., 2022; mayewski et al., 2004) (figs. 7a-b). this indicates that the island remained uninhabited during a period of global and regional climatic deterioration. as with other late holocene rccs, this phenomenon is associated with three distinct phases of sunspot minima, including the homeric minimum between 2.8 and 2.55 ka bp (martin-puertas et al., 2012; steinhilber et al., 2009) (fig. 7c), as well as with stratospheric sulfate injections from unknown explosive volcanic eruptions (sigl et al., 2022), which contributed to global cooling (mcgregor et al., 2015). evidence of glacier advances in central asia, the southern hemisphere, north america, and scandinavia (denton & karlén, 1973; haug et al., 2001) confirms the widespread nature of this phenomenon, which is thought to have been extremely rapid and effective (krishnamohan et al., 2019; mcgregor et al., 2015). at a regional scale, the phase of ustica’s abandonment coincides with a ~2°c cooling recorded in the tyrrhenian core bs 79-38 (sbaffi et al., 2001) (cooling event c2 in fig. 7d), located just a few nautical miles away (fig. 1a), and with an increase of ~15 gc m² yr ¹ in net primary productivity at the sicily channel odp 963 site (incarbona et al., 2008) (fig. 7e). the combination of these two proxies, from both northern and southern sicily offshore locations, suggests the arrival of pro 68 tab. 1 revised calibrations of radiocarbon datings at villaggio dei faraglioni by holloway (1995). from the left: sample laboratory code; radiocarbon age and its uncertainty; calibration by holloway (1995) in years bce; revised calibration by oxcal v4.4.4 (bronk ramsey, 2021), with the atmospheric data by reimer et al. (2020). fig. 6 two aerial perspectives of the villaggio dei faraglioni. on the left, in the view from the north-east, the two stacks and the high cliff coast are highlighted. on the right, from the north-west, the orderly urban layout of the town can be appreciated, characterized by a main road with huts and courtyards at its edges. drone photo respectively by ingv and v. ambrosanio. f. foresta martin, a. incarbona 69 late bronze age collapse at ustica island (sicily-italy): the drought hypothesis fig. 7 late bronze age abandonment (red dashed line) and ellenistic-roman re-occupation (blue dashed line) at ustica island and selected paleoclimatic records. (a) ice rafted detritus (grains/g) from north atlantic, note the reversed axis. the black line has an infilling above 5 grains/g (bond et al., 1997. b1-b4 are bond cycles. (b) mediterranean sst (°c) stack. the blue line is a running average of xx points, with an infilling below 0 (marriner et al., 2022). the cooling of the 3.2 ka bp event is labelled (c) total solar irradiation (w/m2). the red line is a running average of xx points, with an infilling below 0 (steinhilber et al., 2009). the homeric sunspot minimum is shown. (d) sea surface temperatures (°c) in the tyrrhenian sea core bs 79-38 (sbaffi et al., 2001). the green line has an infilling below 17°c. the cold event c2 is shown. (e) net primary productivity estimates (mgc x m-2 x d-1) in the sicily channel odp site 963, note the reversed axis. the purple line has an infilling above 175 mgc x m-2 x d-1 (incarbona et al., 2008). (f) k+ (ppb) in greenland gisp2 ice cores, note the reversed axis. the orange line is a running average of xx points, with an infilling below 1 ppb (mayewski et al., 1997). the light grey shadow indicates the rapid climate change of the late bronze age (mayewski et al., 2004). all curves are plotted versus age expressed in years bp. late bronze age abandonment and ellenistic-roman re-occupation ages were converted into years bp. the siberian high (mayewski et al., 1997; 2004). focusing on atmospheric patterns and precipitation levels, stable isotope records from speleothems in both cueva de asiul (northern spain) and corchia cave (central italy) reveal pronounced drought episodes beginning with ustica’s abandonment at 3.15 ka bp (isola et al., 2019; smith et al., 2016), which were particularly severe during the homeric minimum (fig. 8a-b). speciflonged northerly atmospheric outbreaks, which cooled sea surface water and promoted vertical mixing in the water column, thereby fueling nutrient availability in the photic zone (cortina-guerra et al., 2021; incarbona et al., 2008, 2010a, 2016, 2019). the strengthening of atmospheric circulation in the northern hemisphere is further supported by the k+ record from greenland ice cores (fig. 7f), a proxy for the expansion and activity of 70 fig. 8 late bronze age abandonment (red dashed line) and ellenistic-roman re-occupation (blue dashed line) at ustica island and selected paleoclimatic records. (a) d18o values (‰) in cueva de asiul speleothem, note the reversed axis. the black line has an infilling above 5.5 ‰ (smith et al., 2016). higher and lower values are respectively associated with dry and wet phases and with prevalent positive and negative nao phases. (b) d18o values (‰) in corchia cave speleothem, note the reversed axis. the blue line is a running average of 3 points, with an infilling above 4.75 ‰. higher and lower values are respectively associated with dry and wet phases (isola et al., 2019). (c) d18o values (‰) in mawmluh cave speleothem, note the reversed axis. the red line is a running average of 7 points, with an infilling above 6.0 ‰. higher and lower values are respectively associated with dry and wet phases (berkelhammer et al., 2012). (d) preindustrial/ industrial changes in climate and society, following abram et al. (2016), büntgen et al. (2016) and margaritelli et al. (2016). roman period; dark age; mca: medieval climate anomaly; lia: little ice age; ie: industrial era. ages of these periods were converted into years bp. (e) population variations in italy (million individuals) between the imperial roman period and the middle ages in purple line (barbiera & dallazuanna, 2024). (f) d18o values (‰) in cueva de asiul speleothem, note the reversed axis. the green line is a running average of 5 points. higher and lower values are respectively associated with dry and wet phases (smith et al., 2016). all curves are plotted versus age expressed in years bp. late bronze age abandonment and ellenistic-roman re-occupation ages were converted into years bp. f. foresta martin, a. incarbona sahara phase) due to the northward shift of the intertropical convergence zone, which brought monsoon rainfall over a much wider catchment. at the same time, the nile river discharged massive volumes of freshwater into the eastern mediterranean, leading to the formation of an organic-rich seafloor layer (grant et al., 2017; rohling et al., 2015; tierney et al., 2017). while monsoon rains never reached mediterranean coastal areas, their intensification coincided with more frequent winter storm tracks from north atlantic low-pressure systems (dixit et al., 2020; toucanne et al., 2015; wagner et al., 2019). however, peak precipitation in southern europe may have been slightly delayed, sustaining high moisture availability throughout the middle holocene (capraro et al., 2023; magny et al., 2013; peyron et al., 2013; tinner et al., 2009; zanchetta et al., 2007). thus, while earlier climatic deteriorations (e.g., b4 in fig. 7) provided sufficient rainfall to sustain ustica’s population, the 4.2 ka bp event marked the first significant regional aridification episode. the hellenistic-roman reoccupation of ustica followed a general climatic improvement and, crucially, advancements in rainwater harvesting techniques, mitigating the effects of later droughts, including those of the dark ages (da) and the little ice age (lia, fig. 8d). severe droughts occurred in sicily during the lia, as documented in historical records (incarbona et al., 2010b; piervitali & colacino, 2001) and may have contributed to make the island uninhabitable between the 13th and 18th century, which is indeed ascribed to pirate raids by historians. while no ancient demographic estimates exist for ustica or sicily, data from the italian peninsula (6th-15th century ce) (barbiera & dallazuanna, 2024) (fig. 8e) reveal a striking correlation between population climate variability played a decisive role in ustica’s late bronze age collapse. 5. conclusion the hypothesis of severe drought as the cause of the eight-century-long abandonment of ustica island has been tested by leveraging advances in mediterranean paleoclimatology. the unoccupied phase of ustica island, between 3.2-3.15 and 2.25 ka bp, coincides with a global and regional period of climatic deterioration. this phase is associated with three distinct sunspot minimum periods (martin-puertas et al., 2012; steinhilber et al., 2009) (fig. 7c) and explosive volcanic eruptions (sigl et al., 2022), which contributed to global cooling (mcgregor et al., 2015). this interval is also characterized by sst cooling in the southern tyrrhenian sea and increased primary productivity in the sicily channel (sbaffi et al., 2001; incarbona et al., 2008), suggesting that prolonged atmospheric perturbations led to cooler sea surface temperatures and enhanced vertical mixing in the water column. climatic deterioration is coupled with severe drought, as inferred from speleothem oxygen isotope records in north spain and central italy, as well as lake level drops in sicily (isola et al., 2019; magny et al., 2007, 2011; sadori & narcisi, 2001; smith et al., 2016). a predominantly positive nao phase may have contributed to aridification across southern europe, the near east, and the middle east, where numerous societies declined or collapsed (drake, 2012; hazell et al., 2022; manning et al., 2023; weiss, 1982). the drought in sicily and ustica between 3.2 and ically, the speleothem record from northern spain suggests that a predominantly positive nao phase was established (fig. 8a), leading to arid conditions in southern europe (smith et al., 2016). the central italian speleothem record indicates reduced precipitation levels (fig. 8b) (isola et al., 2019), which likely affected the southern tyrrhenian sea as well. a marked drought episode in sicily between 3.2 and 3.0 ka bp is further supported by paleohydrological data from lake pergusa (magny et al., 2007; sadori & narcisi, 2001) and by a definitive water level drop at lake preola (magny et al., 2011). vegetation opening is evident in different sicily sites, but it may be due, at least partly, to the increased agricultural and pastoral activities in the island during the late bronze age (e.g. bisculm et al., 2012; calò et al., 2012; noti et al., 2009; tinner et al., 2009). it is worth noting that the pronounced drought affecting sicily and ustica between 3.2 and 3.0 ka bp appears to be the culmination of an aridification trend that began on a global and regional scale with the 4.2 ka bp event (bini et al., 2019). the 4.2 ka bp event represents a major reorganization of the global climate system and marks the beginning of the meghalayan stage within the holocene series (walker et al., 2018). among other impacts, the significant weakening of the east asian and indian summer monsoons (fig. 8c) has been linked to societal collapses in mesopotamia, india, the tibetan plateau, and china (blanco-gonzález et al., 2018; d’alpoim guedes et al., 2016; guo et al., 2018; ponton et al., 2012; zhang et al., 2018). in the central mediterranean, this megadrought event is documented by speleothem records (isola et al., 2019; zanchetta et al., 2016), while a decline in arboreal pollen suggests forest opening south of 39°n, similar to ustica’s geographic setting (di rita & magri, 2019; tinner et al., 2016). we propose that this long-term aridification trend may have culminated abruptly during the late bronze age, causing severe drought on ustica. water scarcity may have led to sanitary issues, such as contamination from animal waste and epidemic outbreaks, and/or crop failure and famine. although speculative, this hypothesis provides a more plausible explanation for the wellpreserved defensive walls, domestic architecture and pottery at villaggio dei faraglioni than scenarios involving natural disasters or hostile invasions. climate deterioration and drought have long been considered primary drivers of the late bronze age collapse (~1200 bce) across the eastern mediterranean and near and middle eastern societies. mycenaean, aegean, and anatolian populations fragmented into small settlements, the hittite empire collapsed, and both the assyrian empire and egypt’s new kingdom experienced decline (drake, 2012; hazell et al., 2022; manning et al., 2023; weiss, 1982). this broad geographical region suffered from socio-economic and political instability, conflicts, migrations, and depopulation. ustica serves as an especially suitable case study for evaluating the impacts of climate change, as its small geographic extent and limited resources meant that abandonment was the only viable response to climate deterioration and drought. one might question why ustica was abandoned specifically between 1200 and 300 bce, despite multiple previous and subsequent episodes of climate deterioration (fig. 7). to address this, we must consider holocene climate evolution. between 10.5 and 6.0 ka bp, the north african desert nearly disappeared (last green 71 late bronze age collapse at ustica island (sicily-italy): the drought hypothesis doi: 10.4319/lo.1997.42.1.0001 berkelhammer m.b., sinha a., stott l., cheng h., pausata f.s.r., yoshimura k. (2012) an abrupt shift in the indian monsoon 4000 years ago. geophysical monographs series, 198, 75-87. doi: 10.1029/2012gm001207 bini m., zanchetta g., perşoiu a., cartier r., català a., cacho i., dean j.r., di rita f., drysdale r.n., finnè m., isola i., jalali b., lirer f., magri d., masi a., marks l., mercuri a.m., peyron o., sadori l., sicre m.-a., welc f., zielhofer c., brisset e. (2019) the 4.2 ka bp event in the mediterranean region: an overview. climate of the past, 15(2), 555-577. doi: 10.5194/cp-15-555-2019 bisculm m., colombaroli d., vescovi e., van leeuwen j. f.n., henne p.d., rothen j., procacci g., pasta s., la mantia t., tinner w. (2012) holocene vegetation and fire dynamics in the supramediterranean belt of the nebrodi mountains (sicily, italy). journal of quaternary science, 27 (7), 687-698. doi: 10.1002/jqs.2551 blanco-gonzález a., lillios k.t., lópez-sáez j.a., drake b.l. (2018) cultural, demographic and environmental dynamics of the copper and early bronze age in iberia (3300-1500 bc): towards an interregional multiproxy comparison at the time of the 4.2 ky bp event. journal of world prehistory, 31(1), 1-79. doi: 10.1007/s10963-018-9113-3 bond g., showers w., cheseby m., lotti r., almasi p., demenocal p., priore p., cullen h., hajdas i., bonani g. (1997) a pervasive millennial-scale cycle in north atlantic holocene and glacial climates. science, 278(5341), 1257-1266. doi: 10.1126/science.278.5341.1257 bond g., kromer b., beer j., muscheler r., evans m.n., showers w., hoffmann s., lotti-bond r., hajdas i., bonani g. (2001) persistent solar influence on north atlantic climate during the holocene. science (new york, n.y.), 294(5549), 2130-2136. doi: 10.1126/science.1065680 bronk ramsey c. (2021) oxcal v.4.4.4 [software]. https://c14.arch.ox.ac.uk/oxcal.html buccheri g., d’arpa c., foresta martin f. (2014) a geosite to be saved: the tyrrhenian fossil deposit on the island of ustica. il naturalista siciliano, xxxviii, 179-191. büntgen u., myglan v.s., ljungqvist f.c., mccormick m., di cosmo n., sigl m., jungclaus j., wagner s., krusic p.j., esper j., kaplan j.o., de vaan m.a.c., luterbacher j., wacker l., tegel w., kirdyanov a.v. (2016) cooling and societal change during the late antique little ice age from 536 to around 660 ad. nature geoscience, 9(3), 231-236. doi: 10.1038/ngeo2652 calò c., henne p.d., curry b., magny m., vescovi e., la mantia t., pasta s., vannière b., tinner w. (2012) spatio-temporal patterns of holocene environmental change in southern sicily. palaeogeography, palaeoclimatology, palaeoecology, 323-325, 110-122. doi: 10.1016/j.palaeo.2012.01.038 capraro l., incarbona a., fornaciari e., sabatino n., 3.0 ka bp may represent the culmination of an aridification trend that began on both regional and global scales following the 4.2 ka bp event (bini et al., 2019), likely leading to epidemic outbreaks and famine. analyzing the holocene climatic evolution of the region suggests that previous episodes of climate deterioration still provided sufficient rainfall to sustain ustica’s population. after the hellenistic-roman reoccupation (3rd century bce), significant advancements in rainwater harvesting techniques mitigated the effects of subsequent droughts, including those during the dark age (da) and the little ice age (lia) (fig. 8d). however, the close correlation between population fluctuations in italy and north spain speleothem oxygen isotope records (barbiera & dallazuanna, 2024; smith et al., 2016) over the 6th to 15th centuries ce (fig. 4e-f) highlights the pervasive influence of climate variability, even on more advanced societies. this relationship in historical times further supports the hypothesis that climate change played a critical role in the late bronze age collapse at ustica island. this case study underscores the importance of an interdisciplinary approach that integrates paleoclimatic and archaeological records to understand past societal responses to environmental change. acknowledgments we are grateful to ilaria mazzini for helpful comments and suggestions. ai acknowledges the support received from the nbfc, funded by the italian ministry of university and research, pnrr, missione 4 componente 2, project cn00000033. we also thank v. ambrosiano for providing the drone photo shown in figure 6. references abram n.j., mcgregor h.v., tierney j.e., evans m.n., mckay n.p., kaufman d.s., thirumalai k., martrat b., goosse h., phipps, s.j., steig, e.j., kilbourne k.h., saenger c.p., zinke j., leduc g., addison j. a., mortyn p.g., seidenkrantz m.s., sicre m.a., von gunten l. (2016) early onset of industrialera warming across the oceans and continents. nature, 536 (7617), 411-418. doi: 10.1038/nature19082 alberti g. (2013) issues in the absolute chronology of the early-middle bronze age transition in sicily and southern italy: a bayesian radiocarbon view. journal of quaternary science, 28, 630-640. doi: 10.1002/jqs.2659 alley r.b., mayewski p.a., sowers t., stuiver m., taylor k.c., clark p.u. (1997) holocene climatic instability: a prominent, widespread event 8200 yr ago. geology, 25(6), 483-486. doi: 10.1130/0091-7613(1997)025<0483 barbiera i., dalla-zuanna g. (2024) demographic systems of medieval italy (6th-15th century ad). population and development review, 50(2), 541-570. doi: 10.1111/padr.12611 barraco picone m.g. (2007) ustica: itinerari attraverso il paesaggio, le popolazioni e l’architettura di un’isola unica. centro studi e documentazione dell’isola di ustica, palermo. behrenfeld m.j., falkowski p.g. (1997) photosynthetic rates derived from satellite-based chlorophyll concentration. limnology and oceanography, 42(1), 120. 72 f. foresta martin, a. incarbona https://c14.arch.ox.ac.uk/oxcal.html role of the mid-holocene environmental transition in the decline of late neolithic cultures in the deserts of ne china. quaternary science reviews, 190, 98-113. doi: 10.1016/j.quascirev.2018.04.017 haug g.h., hughen k.a., sigman d.m., peterson l.c., röhl u. (2001) southward migration of the intertropical convergence zone through the holocene. science, 293(5533), 1304-1308. hazell c.j., matthew j.p., hocking e.p. (2022) highresolution bronze age palaeoenvironmental change in the eastern mediterranean: exploring the links between climate and societies. palynology, 46(4), 1-20. doi: 10.1080/01916122.2022.2067259 hemming s.r. (2004) heinrich events: massive late pleistocene ditritus layers of the north atlanitc and their global cliamate imprint. reviews of geophysics, 42, 1-43. holloway r.r. (1995) ustica.: the results of the excavations of the regione siciliana, soprintendenza ai beni culturali ed ambientali provincia di palermo in collaboration with brown university in 1990 and 1991, center for old world archaeology and art, brown university. hughen k.a., southon j.r., lehman s.j., overpeck j.t. (2000) synchronous radiocarbon and climate shifts during the last deglaciation. science, 290 (5498), 1951-1955. doi: 10.1126/science.290.5498.1951 hurrell j.w. (1995) decadal trends in the north atlantic oscillation: regional temperatures and precipitation. science, 269(5224), 676-679. incarbona a., di stefano e., parti b., pelosi n., bonomo s., mazzola s., sprovieri r., tranchida g., zgozi s., bonanno a. (2008) holocene millennial-scale productivity variations in the sicily channel (mediterranean sea). paleoceanography, 23(3), 118. doi: 10.1029/2007pa001581 incarbona a., ziveri p., di stefano e., lirer f., mortyn g., patti b., pelosi n., sprovieri m., tranchida g., vallefuoco m., albertazzi s., bellucci l.g., bonanno a., bonomo s., censi p., ferraro l., giuliani s., mazzola s., sprovieri r. (2010a) the impact of the little ice age on coccolithophores in the central mediterranea sea. climate of the past, 6(6), 795-805. doi: 10.5194/cp-6-795-2010 incarbona a., zarcone g., agate m., bonomo s., stefano e., masini, f., russo, f., sineo, l. (2010b) a multidisciplinary approach to reveal the sicily climate and environment over the last 20 000 years. open geosciences, 2(2), 71-82. doi: 10.2478/v10085-010-0005-8 incarbona a., sprovieri m., di stefano a., di stefano e., salvagio manta d., pelosi n., ribera d’alcalà m., sprovieri r., ziveri p., di a., di e., salvagio d., pelosi n., ribera m., sprovieri r., ziveri p. (2013) productivity modes in the mediterranean sea during dansgaard-oeschger (20,000-70,000yr ago) oscillations. palaeogeography, palaeoclimatology, palaeoecology, 392, 128-137. doi: 10.1016/j.palaeo.2013.09.023 incarbona a., martrat b., mortyn p.g., sprovieri m., ziveri p., gogou a., jordà g., xoplaki e., scaillet s., sprovieri r., sprovieri m. (2023) hydroclimate variability in the central mediterranean during mis 17 interglacial (middle pleistocene) highlights timing offset with monsoon activity. scientific reports, 13(1), 18938. doi: 10.1038/s41598-023-45812-x cortina-guerra a., gomez-navarro j.j., martrat b., montávez j.p., incarbona a., grimalt j. o., sicre m.-a., mortyn p.g. (2021) northern hemisphere atmospheric pattern enhancing eastern mediterranean transient-type events during the past 1000 years. climate of the past, 17(4), 1523-1532. doi: 10.5194/cp-17-1523-2021 d’alpoim guedes j., manning s.w., bocinsky r.k. (2016) a 5,500-year model of changing crop niches on the tibetan plateau. current anthropology, 57(4), 517-522. de vita s., foresta martin f. (2017) the palaeogeographic setting and the local environmental impact of the 130 ka falconiera tuff-cone eruption (ustica island, italy). annals of geophysics, 60(2), 1-12. de vita s. orsi g. (1994) i terrazzi marini dell’isola di ustica (mar tirreno meridionale, italia), mem. descr. carta geol. d’it., 52, 405-406. de vita s., guzzetta g., orsi g. (1995). deformational features of the ustica volcanic island in the southern tyrrhenian sea (italy). terra nova, 7(6), 623629. de vita s., laurenzi m.a., orsi g., voltaggio m. (1998) application of 40ar/39ar and 230th dating methods to the chronostratigraphy of quaternary basaltic volcanic areas: the ustica island case history. quaternary international, 47-48, 117-127. denton g.h., karlén w. (1973) holocene climatic variations -their pattern and possible cause. quaternary research, 3(2), 155-205. di rita f., magri d. (2019) the 4.2ka event in the vegetation record of the central mediterranean. climate of the past, 15(1), 237-251. doi: 10.5194/cp-15-237-2019 dixit y., toucanne s., fontanier c., pasquier v., lora j. m., jouet g., tripati a. (2020) enhanced western mediterranean rainfall during past interglacials driven by north atlantic pressure changes. quaternary international, 553, 1-13. doi: 10.1016/j.quaint.2020.08.017 drake b.l. (2012) the influence of climatic change on the late bronze age collapse and the greek dark ages. journal of archaeological science, 39(6), 1862-1870. finkel r.c., nishiizumi k. (1997) beryllium 10 concentrations in the greenland ice sheet project 2 ice core from 3-40 ka. journal of geophysical research, oceans, 102(c12), 26699-26706. foresta martin f., furlani s. (2021) geomorphology and prehistoric settlements on a volcanic island: the case of ustica (palermo, italy). annals of geophysics, 64(5), 1-31. grant k.m., rohling e.j., westerhold t., zabel m., heslop d., konijnendijk t., lourens l. (2017) a 3 million year index for north african humidity/aridity and the implication of potential pan-african humid periods. quaternary science reviews, 171, 100118. doi: 10.1016/j.quascirev.2017.07.005 guo l., xiong s., ding z., jin g., wu j., ye w. (2018) 73 late bronze age collapse at ustica island (sicily-italy): the drought hypothesis https://dx.doi.org/10.1029/2007pa001581 (2011) holocene hydrological changes in southwestern mediterranean as recorded by lake-level fluctuations at lago preola, a coastal lake in southern sicily, italy. quaternary science reviews, 30(19-20), 2459-2475. doi: 10.1016/j.quascirev.2011.05.018 magny m., combourieu-nebout n., de beaulieu j.l., bout-roumazeilles v., colombaroli d., desprat s., francke a., joannin s., ortu e., peyron o., revel m., sadori l., siani g., sicre m. a., samartin s., simonneau a., tinner w., vannière b., wagner b., zanchetta g., anselmetti f., brugiapaglia e., chapron e., debret m., desmet m., didier j., essallami l., galop d., gilli a., haas n., kallel n., millet l., stock a., turon j. l., wirth s. (2013) north-south palaeohydrological contrasts in the central mediterranean during the holocene: tentative synthesis and working hypotheses. climate of the past, 9(5), 2043-2071. doi: 10.5194/cp-9-2043-2013 manning s.w., kocik c., lorentzen b., sparks j.p. (2023) severe multi-year drought coincident with hittite collapse around 1198-1196 bc. nature, 614 (7949), 719-724. doi: 10.1038/s41586-022-05693-y mannino g. (1982) il villaggio dei faraglioni di ustica. notizie preliminari. studi in onore di ferrante rittatore vonwiller, società archeologica comense, como, italy, 279-297. mannino g. (1998) il neolitico nel palermitano e la nuova scoperta nell’isola di ustica. quaderni del museo archeologico regionale antonino salinas, 4, 45-80. margaritelli g., vallefuoco m., di rita f., capotondi l., bellucci l.g., insinga d.d., petrosino p., bonomo s., cacho i., cascella a., ferraro l., florindo f., lubritto c., lurcock p.c., magri d., pelosi n., rettori r., lirer f. (2016) marine response to climate changes during the last five millennia in the central mediterranean sea. global and planetary change, 142, 53-72. doi: 10.1016/j.gloplacha.2016.04.007 margaritelli g., cacho i., català a., bellucci l., lubritto c., rettori r., lirer f. (2019) persistent warm mediterranean surface waters during the roman period. scientific reports, 10431, 1-10. doi: 10.1038/s41598-020-67281-2 marriner n., kaniewski d., pourkerman m., devillers b. (2022) anthropocene tipping point reverses longterm holocene cooling of the mediterranean sea: a meta-analysis of the basin’s sea surface temperature records. earth-science reviews, 227, 103986. doi: 10.1016/j.earscirev.2022.103986 martin-puertas c., matthes k., brauer a., muscheler r., hansen f., petrick c., aldahan a., possnert g., van geel b. (2012) regional atmospheric circulation shifts induced by a grand solar minimum. nature geoscience, 5(6), 397-401. doi: 10.1038/ngeo1460 martrat b., grimalt j.o., lopez-martinez c., cacho i., sierro f.j., flores j.a., zahn r., canals m., curtis j.h., hodell d.a. (2004) abrupt temperature changes in the western mediterranean over the past 250,000 years. science, 306(5702), 1762 luterbacher j., langone l., marino g., rodríguezsanz l., triantaphyllou m., di stefano e., grimalt j.o., tranchida g., sprovieri r., mazzola s. (2016) mediterranean circulation perturbations over the last five centuries: relevance to past eastern mediterranean transient-type events. scientific reports, 6, 1-10. doi: 10.1038/srep29623 incarbona a., jonkers l., ferraro s., sprovieri r., tranchida g. (2019) sea surface temperatures and paleoenvironmental variability in the central mediterranean during historical times reconstructed using planktonic foraminifera. paleoceanography and paleoclimatology, 34(3), 394408. doi: 10.1029/2018pa003529 isola i., zanchetta g., drysdale r. n., regattieri e., bini m., bajo p., hellstrom j. c., baneschi i., lionello p., woodhead j., greig a. (2019) the 4.2ka event in the central mediterranean: new data from a corchia speleothem (apuan alps, central italy). climate of the past, 15(1), 135-151. doi: 10.5194/cp-15-135-2019 krishnamohan k.-p.s.-p., bala g., cao l., duan l., caldeira k. (2019) climate system response to stratospheric sulfate aerosols: sensitivity to altitude of aerosol layer. earth system dynamics, 10(4), 885-900. doi: 10.5194/esd-10-885-2019 leighton r. (2004) fortress ustica? an island world in the bronze age. american journal of archaeology, 108, 103-106. lionello p. (2012) the climate of the mediterranean region: from the past to the future (1st ed.), elsevier inc., amsterdam, the netherlands, pp. 502. doi: 10.1016/b978-0-12-416042-2.00009-4 luterbacher j., dietrich d., xoplaki e., grosjean m., wanner h. (2004) european seasonal and annual temperature variability, trends, and extremes since 1500. science, 303(5663), 1499-1503. doi: 10.1126/science.1093877 luterbacher j., xoplaki e., dietrich d., jones p.d., davies, t.d., portis d., gonzalez-rouco j.f., von storch h., gyalistras d., casty c., wanner h. (2001) extending north atlantic oscillation reconstructions back to 1500. atmospheric science letters, 2(1-4). maasch k.a., mayewski p.a., rohling e.j., stager j.c., karlén w., meeker l.d., meyerson e.a. (2005) a 2000-year context for modern climate change. geografiska annaler, series a: physical geography, 87(1), 7-15. doi: 10.1111/j.0435-3676.2005.00241.x magny m., de beaulieu j.l., drescher-schneider r., vannière b., walter-simonnet a. v., miras y., millet l., bossuet g., peyron o., brugiapaglia e., leroux a. (2007) holocene climate changes in the central mediterranean as recorded by lakelevel fluctuations at lake accesa (tuscany, italy). quaternary science reviews, 26(13-14), 17361758. doi: 10.1016/j.quascirev.2007.04.014 magny m., vannière b., calo c., millet l., leroux a., peyron o., zanchetta g., la mantia t., tinner w. 74 f. foresta martin, a. incarbona from observations and modelling: a review. palaeogeogr palaeoclimatol palaeoecol 158, 153174. doi: 10.1016/s0031-0182(00)00048-1 ponton c., giosan l., eglinton t.i., fuller d.q., johnson j.e., kumar p., collett t.s. (2012) holocene aridification of india. geophysical research letters, 39(3). doi: 10.1029/2011gl050722 reimer p.j., austin w.e.n., bard e., bayliss a., blackwell p.j., bronk ramsey c., butzin m., cheng h., edwards r.l., friedrich m., grootes p.m., guilderson t.p., hajdas i., heaton t.j., hogg a.g., hughen k.a., kromer b., manning s.w., muscheler r., palmer j.g., pearson c., van der plicht j., reimer r.w., richards d.a., scott e.m., southon j.r., turney c.s.m., wacker l., adolphi f., buntgen u., capano m., fahrni s.m., fogtmann-schul a., friedrich r., kohler p., kudsk s., miyake f., olsen j., reinig f., sakamoto m., sookdeo a., talamo s. (2020) the intcal20 northern hemisphere radiocarbon age calibration curve (0-55 cal kbp). radiocarbon, 62(4), 725-757. doi: 10.1017/rdc.2020.41 rogerson m., colmenero-hidalgo e., levine r.c., rohling e.j., voelker a.h. l., bigg g.r., schönfeld j., cacho i., sierro f. j., löwemark l., reguera m. i., de abreu l., garrick k. (2010) enhanced mediterranean-atlantic exchange during atlantic freshening phases. geochemistry, geophysics, geosystems, 11(8), 1-22. doi: 10.1029/2009gc002931 rogerson m., rohling e.j.r., bigg g.r., ramirez j. (2012) paleoceanography of the atlanticmediterranean exchange: overview and first quantitative assessment of climatic forcing. reviews of geophysics, 50. doi: 10.1029/2011rg000376.1 rohling e.j., marino g., grant k.m. (2015) mediterranean climate and oceanography, and the periodic development of anoxic events (sapropels) earthscience reviews, 143, 62-97. doi: 10.1016/j.earscirev.2015.01.008 russolillo a., martin f. f., merico a., sapia v., talamo p., materni v., pischiutta m., de vita s., furlani s., targia d., di vito m.a. (2024) unveiling a hidden fortification system at “faraglioni” middle bronze age village of ustica island (palermo, italy) through ert and gpr prospections. journal of applied geophysics, 220, 105272. doi: 10.1016/j.jappgeo.2023.105272 sadori l., narcisi b. (2001) the postglacial record of environmental history from lago di pergusa, sicily. holocene, 11, 655-671. doi: 10.1191/09596830195681 sbaffi l., wezel f.c., kallel n., paterne m., cacho i., ziveri p., shackleton n. (2001) response of the pelagic environment to palaeoclimatic changes in the central mediterranean sea during the late quaternary. marine geology, 178(1-4), 39-62. schlitzer r. (2025) ocean data view 4.0. https://odv.awi.de sigl m., toohey m., mcconnell j.r., cole-dai j., severi m. (2022) volcanic stratospheric sulfur injections and aerosol optical depth during the holocene -1765. doi: 10.1126/science.1101706 mayewski p.a., meeker l.d., twickler m.s., whitlow s., yang q., lyons w.b., prentice m. (1997) major features and forcing of high-latitude northern hemisphere atmospheric circulation using a 110,000year-long glaciochemical series. journal of geophysical research: oceans, 102(c12), 2634526366. doi: 10.1029/96jc03365 mayewski p.a., rohling e.e., stager j.c., karlén w., maasch k.a., meeker l.d., meyerson e.a., gasse f., van kreveld s., holmgren k., lee-thorp j., rosqvist g., rack f., staubwasser m., schneider r.r., steig e.j. (2004) holocene climate variability. quaternary research, 62(3), 243-255. doi: 10.1016/j.yqres.2004.07.001 mcgregor h.v., evans m.n., goosse h., leduc g., martrat b., addison j.a., mortyn p.g., oppo d.w., seidenkrantz m.s., sicre m.a., phipps s.j., selvaraj k., thirumalai k., filipsson h. l., ersek v. (2015) robust global ocean cooling trend for the pre-industrial common era. nature geoscience, 8 (9), 671-677. doi: 10.1038/ngeo2510 medecc (2021). climate and environmental change in the mediterranean basin current situation and risks for the future. first mediterranean assessment report [cramer w., guiot j., marini k. (eds.)] union for the mediterranean, plan bleu, unep/ map, marseille, france, pp. 632. doi: 10.5281/zenodo.4768833 meeker l.d., mayewski p.a. (2002) a 1400-year highresolution record of atmospheric circulation over the north atlantic and asia. the holocene, 12(3), 257-266. doi: 10.1191/0959683602hl542ft noti r., van leeuwen j.f.n., colombaroli d., vescovi e., pasta s., la mantia t., tinner w. (2009) mid and late-holocene vegetation and fire history at biviere di gela, a coastal lake in southern sicily, italy. vegetation history and archaeobotany, 18(5), 371-387. doi: 10.1007/s00334-009-0211-0 olsen j., anderson n.j., knudsen m.f. (2012) variability of the north atlantic oscillation over the past 5,200 years. nature geoscience, 5(11), 808-812. doi: 10.1038/ngeo1589 oppo d.w., mcmanus j.f., cullen j.l. (2003) deepwater variability in the holocene epoch. nature, 422, 277. doi: 10.1038/422277b peyron o., magny m., goring s., joannin s., de beaulieu j.-l., brugiapaglia e., sadori l., garfi g., kouli k., ioakim c., combourieu-nebout n. (2013) contrasting patterns of climatic changes during the holocene across the italian peninsula reconstructed from pollen data. climate of the past, 9(3), 1233-1252. doi: 10.5194/cp-9-1233-2013 piervitali e., colacino m. (2001) evidence of drought in western sicily during the period 1565-1915 from liturgical offices. climate change, 225-238. doi: 10.1023/a:1010746612289 pinardi n., masetti e. (2000) variability of the large scale general circulation of the mediterranean sea 75 late bronze age collapse at ustica island (sicily-italy): the drought hypothesis https://zenodo.org/record/4768833 toucanne s., angue minto’o c.m., fontanier c., bassetti, m.a., jorry s.j., jouet g. (2015) tracking rainfall in the northern mediterranean borderlands during sapropel deposition. quaternary science reviews, 129, 178-195. doi: 10.1016/j.quascirev.2015.10.016 trouet v., esper j., graham n.e., baker a., scourse j.d., frank d.c. (2009) persistent positive north atlantic oscillation mode dominated the medieval climate anomaly. science, 324(5923), 78-80. doi: 10.1126/science.1166349 wagner b., vogel h., francke a., friedrich t., donders t., lacey j.h., leng m.j., regattieri e., sadori l., wilke t., zanchetta g., albrecht c., bertini a., combourieu-nebout n., cvetkoska a., giaccio b., grazhdani a., hauffe t., holtvoeth j., joannin s., jovanovska e., just j., kouli k., kousis i., koutsodendris a., krastel s., lagos m., leicher n., levkov z., lindhorst k., masi a., melles m., mercuri a.m., nomade s., nowaczyk n., panagiotopoulos k., peyron o., reed j.m., sagnotti l., sinopoli g., stelbrink b., sulpizio r., timmermann a., torri p., wagner-cremer f., wonik t., zhang x. (2019) mediterranean winter rainfall in phase with african monsoons during the past 1.36 million years. nature, 573(7773), 256-260. doi: 10.1038/s41586-019-1529-0 walker m., head m.j., berkelhammer m., björck s., cheng h., cwynar l., fisher d., gkinis v., long a., lowe j., newnham r., rasmussen s.o., weiss h. (2018) formal ratification of the subdivision of the holocene series/epoch (quaternary system/period): two new global boundary stratotype sections and points (gssps) and three new stages/subseries. episodes, 41(4), 213-223. doi: 10.1007/s12594-019-1141-9 wanner h., brönnimann s., casty c., gyalistras d., luterbacher j., schmutz c., stephenson d.b., xoplaki e. (2001) north atlantic oscillation concepts and studies. surveys in geophysics, 22 (4), 321-381. doi: 10.1023/a:1014217317898 weiss b. (1982) the decline of late bronze age civilization as a possible response to climatic change. climatic change, 4(2), 173-198. yannopoulos s., antoniou g., kaiafa-saropoulou m., angelakis a. (2016) historical development of rainwater harvesting and use in hellas: a preliminary review. water science and technology: water supply, 17, 1022-1034. doi: 10.2166/ws.2016.200 zanchetta g., drysdale r.n., hellstrom j.c., fallick a.e., isola i., gagan m.k., pareschi m.t. (2007) enhanced rainfall in the western mediterranean during deposition of sapropel s1: stalagmite evidence from corchia cave (central italy). quaternary science reviews, 26(3-4), 279-286. zanchetta g., regattieri e., isola i., drysdale r., bini m., baneschi i., hellstrom j.c. (2016) the socalled “4.2 event” in the central mediterranean and its climatic teleconnections. alpine and mediterranean quaternary, 29, 5-17. doi: 10.1016/j.quascirev.2006.12.003 zhang w., yan h., dodson j., cheng p., liu c., li j., lu (past 11500 years) from a bipolar ice-core array. earth system science data, 14(7), 3167-3196. doi: 10.5194/essd-14-3167-2022 smith a.c., wynn p.m., barker p.a., leng m.j., noble s.r., tych w. (2016) north atlantic forcing of moisture delivery to europe throughout the holocene. scientific reports, 6(march), 1-7. doi: 10.1038/srep24745 spatafora f. (2009) ustica tra il tirreno e la sicilia. storia del popolamento dell’isola dalla preistoria all’età tardo-romana. in ampolo c. (ed.), immagine e immagini della sicilia e di altre isole del mediterraneo antico. 507-517. scuola normale superiore pisa. spatafora f. (2016) tra mare e terra: la preistoria di ustica e il villaggio dei faraglioni. scienze dell'antichità 22.2, sapienza università di roma. spatafora f. (2023) postfazione a: ustica i. villaggio letterario ed. pp. 304. spatafora f., mannino g. (2008) ustica: guida breve. assessorato regionale dei beni culturali ambientali e della pubblica istruzione. speciale c., freund k.p., de vita s., larosa n., forgia v., battaglia g., tykot r.h., vassallo s. (2021) obsidian from the site of piano dei cardoni, ustica (palermo, italy): preliminary results on the first occupation of the island. 7(1), 273-290. doi: 10.1515/opar-2020-0140 sprovieri m., di stefano e., incarbona a., salvagio manta d., pelosi n., ribera d’alcalà m., sprovieri r. (2012) centennialto millennial-scale climate oscillations in the central-eastern mediterranean sea between 20,000 and 70,000 years ago: evidence from a high-resolution geochemical and micropaleontological record. quaternary science reviews, 46, 126-135. doi: 10.1016/j.quascirev.2012.05.005 steinhilber f., beer j., fröhlich c. (2009) total solar irradiance during the holocene. geophysical research letters, 36(19). doi: 10.1029/2009gl040142 stuiver m., reimer p.j., braziunas t.f. (1998) highprecision radiocarbon age calibration for terrestrial and marine samples. radiocarbon, 40(3), 1127-1151. doi: 10.1017/s0033822200019172 tierney j.e., pausata f.s.r., demenocal p.b. (2017) rainfall regimes of the green sahara. science advances, 3(1), e1601503. doi: 10.1126/sciadv.1601503 tinner w., van leeuwen j.f.n., colombaroli d., vescovi e., van der knaap w.o., henne p.d., pasta s., d’angelo s., la mantia t. (2009) holocene environmental and climatic changes at gorgo basso, a coastal lake in southern sicily, italy. quaternary science reviews, 28(15-16), 1498-1510. doi: 10.1016/j.quascirev.2009.02.001 tinner w., vescovi e., van leeuwen j.f.n., colombaroli d., henne p. d., kaltenrieder p., morales-molino c., beffa g., gnaegi b., van der knaap w.o., la mantia t., pasta s. (2016) holocene vegetation and fire history of the mountains of northern sicily (italy). vegetation history and archaeobotany, 25 (5), 499-519. doi: 10.1007/s00334-016-0569-8 76 f. foresta martin, a. incarbona f., zhou w., an z. (2018) the 9.2 ka event in asian summer monsoon area: the strongest millennial scale collapse of the monsoon during the holocene. climate dynamics, 50(7), 2767-2782. doi: 10.1007/s00382-017-3770-2 zonneveld k.a.f., harper k., klügel a., chen l., de lange g., versteegh g.j.m. (2024) climate change, society, and pandemic disease in roman italy between 200 bce and 600 ce. science advances, 10(4), 1-11. doi: 10.1126/sciadv.adk1033 77 late bronze age collapse at ustica island (sicily-italy): the drought hypothesis ms. received: june 16, 2025 revised: july 10, 2025 accepted: july 12, 2025 available online: july 29, 2025 78 imp. bosi nnuuoovvii pprroocceeddiimmeennttii ccaarrttooggrraaffiiccii ppeerr iill qquuaatteerrnnaarriioo ccoonnttiinneennttaallee:: ll’’eesseemmppiioo ddeellllaa ccaarrttaa ggeeoollooggiiccaa ddeellll''aallttaa vvaallllee ddeellll''aatteerrnnoo ccaarrlloo bboossii11,, ppaaoolloo mmeessssiinnaa11 && mmaarrccoo mmoorroo22 1 istituto di geologia ambientale e geoingegneria del cnr via del fosso del cavaliere, 100 00133 roma e-mail: c.bosi@igag.cnr.it; p.messina@igag.cnr.it 2 istituto nazionale di geofisica e vulcanologia via di vigna murata, 605 00143 roma e-mail: moro@ingv.it. riassunto nell’ambito della cartografia geologica italiana del quaternario continentale i procedimenti più evoluti sono attualmente quelli utilizzati dal progetto per la nuova carta geologica d’italia, alla scala 1:50.000 (carg). l’innovazione più sensibile introdotta da questo progetto è rappresentata dall’adozione delle unità allo-stratigrafiche o delle unità a limiti inconformi (ubsu). alcune realizzazioni degli anni ’90 suggeriscono però la possibilità di altre innovazioni che riguardano il contenuto informativo delle carte, con particolare riguardo alla utilizzazione degli elementi geomorfologici. in alcune delle procedure finora adottate, questi elementi non sono, infatti, più aggiunti a quelli stratigrafici, ma sono integrati con essi in una prospettiva che tende a superare l’abituale separazione fra stratigrafia e geomorfologia. la carta geologica del quaternario dell’alta valle dell’aterno è stata realizzata con procedimenti che rappresentano una radicalizzazione di queste procedure, fino al punto di modificare la struttura delle unità di riferimento. infatti, quelle cartografate non sono più unità stratigrafiche, ma unità corrispondenti ad una integrazione di unità allostratigrafiche ed unità “morfosequenziali”, queste ultime intese come elementi di una sequenza di superfici fossili (di erosione o di accumulo). queste unità, definite come “unità allo-morfosequenziali” (uam), sono di regola delimitate inferiormente da una superficie d’erosione sepolta al disotto della unità allostratigrafica, e superiormente da una, o più, superfici relitte. la principale differenza con le usuali unità stratigrafiche è che mentre queste sono definite principalmente sulla base dei fatti deposizionali, le uam rappresentano in modo esplicito anche i fatti morfogenetici, perfezionando la definizione della successione di eventi che hanno dato origine all’evoluzione geologica dell’area. questa differenza presenta anche conseguenze sul significato delle superfici di discontinuità che delimitano le unità stratigrafiche: esse non sono più considerate come semplici elementi di separazione fra unità allostratigrafiche (o ubsu), ma come testimonianze di eventi morfogenetici ai quali viene assegnata una totale parità di rango con quelli deposizionali. nell’area rilevata sono state riconosciute numerose unità che sono state raggruppate in tre insiemi diversi e precisamente: (i) una successione cronologicamente ordinata di 8 unità allo-morfosequenziali e di 19 unità morfosequenziali rappresentate da superfici relitte; (ii) 6 unità morfosequenziali corrispondenti ad una successione terrazzata almeno in parte più antica della successione precedente; (iii) tre unità stratigrafiche delle quali non è stato possibile definire nel dettaglio i rapporti con la successione cronologicamente ordinata. tutte queste unità sono state indicate con numeri che esprimono la posizione cronologica relativa degli elementi costitutivi (litosomi e forme). in una situazione come quella della zona considerata, dominata dal progressivo incassamento di forme e litosomi la successione delle unità allo-morfosequenziali viene manifestamente a corrispondere alle tappe del progressivo approfondimento del reticolo idrografico. viene quindi ad essere avvalorata la spiccata valenza evolutiva della carta. altre innovazioni adottate nella realizzazione della carta riguardano le indicazioni geomorfologiche e gli elementi strutturali. per le prime si è preferito rinunciare alle indicazioni usualmente riportate nelle carte geologiche (orlo di terrazzo, dolina, ecc.) limitandosi a cartografare solo gli elementi geomorfologici di diretto interesse nei riguardi della ricostruzione degli eventi geologici succedutisi nell’area, rappresentati dalle superfici relitte. per gli elementi strutturali sono state fornite indicazioni sulla cronologia della deformazione e sulla fonte delle valutazioni. tenuto conto che l’alta valle dell’aterno rappresenta un campione significativo delle conche intermontane dell’appennino centrale, la procedura illustrata in questa nota sembra essere suscettibile di una applicazione non strettamente locale. la carta presentata in questa nota si può quindi intendere come una proposta da collocare nella prospettiva metodologica di un superamento degli attuali criteri cartografici per il quaternario continentale. abstract in the field of the italian geological cartography of the continental quaternary deposits at present the most advanced procedures are those used for the new italian geological map project on a scale of 1:50.000 (carg). the most noticeable innovation introduced by this project is represented by the adoption of allo-stratigraphical units or unconformity boundary stratigraphic units (ubsu). some accomplishments in the 90’s, however, suggest the possibility of other innovations that regard the informative content of maps, with a particular consideration to the use of geomorphological elements. in some of the procedures which until now have been adopted, these elements have in fact not been added to those stratigraphic, but have been integrated with a perspective that tends to exceed the usual separation between stratigraphy and geomorphology. the quaternary geological map of the upper aterno valley has been achieved with a process that represents a radical use of these procedures, to such a degree that it modifies the structure of the reference unit. in fact, those cartographed are no longer stratigraphic units, but units that correspond to an integration of allo-stratigraphic units and morphosequencial units, the last agreed to be elements in a sequence of relict surfaces (due to erosion or accumulation). these units, defined as “allo-morphosequencial units” (uam) are delimited lower down by an erosional surface buried below by the allo-stratigraphic unit and above by one or more relict surfaces. the main difference with the usual stratigraphic units is that while these are defined mainly on the basis of depositional events, the uam also represents in an explicit way the morphogenetic events, perfecting the definition of the succession of events that have given origin to the geological evolution of the area. this difference also has consequences on the importance of the erosionial surfaces (unconformity) that delimit the stratigraphic units: they are no longer considered as simple elements of separation between allo-stratigraphic units (or ubsu), but as evidence of morphogenetic events to which is assigned a completely equal rank, as for those depositional. in the surveyed area many units have been recognised which have been divided into three different groups, which are: (i) a chronologically ordered succession of 8 units allo-morfosequenziali and 19 morphosequential units represented by relict surfaces. (ii) 6 morphosequential units corresponding to a terraced succession which is at least in part older than the previous succession il quaternario italian journal of quaternary sciences 1166(1), 2003, 109-120 110 c. bosi, p. messina & m. moro 11.. pprreemmeessssaa la geologia del quaternario continentale e marino costiero1 presenta notoriamente aspetti particolari, quali la rapida variabilità delle litologie e degli ambienti di sedimentazione, la frequenza ed il tipo delle discontinuità stratigrafiche, la prevalente modesta entità degli spessori e la possibilità di scansioni cronologiche molto dettagliate. una buona carta geologica del quaternario presuppone quindi l’adozione di criteri specifici ed un dettaglio di rilevamento inusuale in altri ambiti. per inciso è da osservare che le procedure anche impegnative che possono derivare da questi vincoli sono ampiamente giustificate dal fatto che il quaternario continentale rappresenta il contesto geologico maggiormente interessato dagli interventi antropici; se si eccettua la costruzione di gallerie e, in parte, lo sfruttamento delle risorse naturali, quasi tutti questi interventi riguardano infatti, in modo più o meno diretto, terreni e fenomeni quaternari. malgrado queste circostanze la cartografia geologica in italia si è sviluppata in una prospettiva stratigrafico-strutturale poco attenta alle problematiche quaternarie, con risultati spesso decisamente discutibili. una valutazione al riguardo è quella espressa dall’aiqua (associazione italiana per lo studio del quaternario), fondata sull’analisi di circa 160 carte geologiche pubblicate fino ai primi anni ’90 (bosi e messina, 1993). l’analisi, svolta da un gruppo di lavoro apposito2, ha messo in evidenza che la maggior parte delle carte ufficiali fino a quel tempo prodotte presentava gravi carenze, derivanti principalmente dal modo inadeguato con cui era stata definita la stratigrafia dei sedimenti continentali e marini costieri; altre carenze riguardavano i riferimenti cronologici, i criteri di correlazione fra le unità stratigrafiche, i dati strutturali e la utilizzazione degli elementi morfologici. a questa situazione si è proposto di ovviare il progetto per la nuova carta geologica d’italia alla scala 1:50.000 (carg), varato alcuni anni or sono, che ha introdotto nei criteri di rilevamento per il quaternario sensibili innovazioni (cnr, 1992), la più importante delle quali riguarda l’adozione di unità stratigrafiche più idonee alle specificità del quaternario (unità allostratigrafiche ed unità a limiti inconformi, v. paragrafo seguente). le informazioni disponibili sui risultati finora ottenuti in questo ambito e le esperienze acquisite con altre carte realizzate negli ultimi anni indicano tuttavia che esistono ancora ampi spazi per approfondimenti metodologici. di qui l’opportunità di iniziative come il progetto “carte prototipali” fondato sulla collaborazione fra cnr e servizio geologico nazionale, nel cui ambito è stata realizzata la carta geologica del quaternario dell’alta valle dell’aterno. lo scopo che ci si è prefisso con la redazione di questa carta è quello di fornire un esempio di carta geologica che sviluppa i criteri del progetto carg, nel duplice senso di una maggior coerenza e di una aumentata valenza geologico-evolutiva. la maggior coerenza è stata ottenuta con procedimenti che cercano di superare i l dualismo stratigrafia/geomorfologia riconducendo tutti gli elementi considerati alla comune radice geologica. questo obiettivo è stato ottenuto adottando unità sostanzialmente diverse dalle usuali unità stratigrafiche in quanto discendono da una stretta integrazione di elementi stratigrafici e geomorfologici. l’incremento della valenza evolutiva è stato ottenuto perfezionando la successione di eventi che sono alla base dell’evoluzione geologica dell’area, aumentando di conseguenza la scansione temporale delle valutazioni di cronologia relativa che ne possono derivare. scopo di questa nota è l’illustrazione del procedimento seguito, con particolare riguardo ai suoi aspetti concettuali e metodologici. informazioni più analitiche sulla stratigrafia e sull’evoluzione geologica dell’area sono riportate in un’altra nota (bosi et al., in stampa b). (iii) three stratigraphic units of which it has been impossible to define in detail its relationship with the chronologically ordered succession. all these units have been indicated with numbers that express the relative chronological position of the constituent elements (lithosomes and shapes). in a situation such as the one considered, dominated by the progressive embedding of shapes and lithosomes, the succession of the allo-morphosequential unit is revealed in correspondence to the progressive deepening phases of the hydrographic network. the distinct evolutionary valence of the map is therefore confirmed. other innovations adopted in the making of the map regard the geomorphological indications and the structural elements. for the first, the common indications usually referred to in the geological maps have been abandoned (terrace borders, dolines, etc.) limiting ourselves to cartographing only the geomorphological elements of direct interest in regards to the reconstruction of successive geological events in the area represented by relict surfaces. information on the chronology of the deformation and origin of the evaluation have been provided for the structural elements. taking into account that the upper aterno represents a significant sample of the intermountain valley of the central apennines, the illustrated procedure in this text does not seem to be susceptible to only a strictly local application. the map presented can therefore be considered as a proposal to be placed in a methodological perspective as a surpassing of the present cartographic criteria for the continental quaternary. parole chiave: quaternario, cartografia, conche intermontane. keywords: quaternary, cartography, intramountain basin. 1 nel seguito questo ambito sarà indicato semplicemente con il termine “quaternario”. 2 il gruppo era costituito da c. bartolini, a. bini, c. bosi, l. brancaccio, l. carobene, f. carraro, a. carton, g.b. castiglioni, n. ciaranfi, a. cinque, p. messina, m. panizza, a. sposato e a. ulzega. 22.. pprreecceeddeennttii mmeettooddoollooggiiccii i precedenti metodologici di maggior interesse nei riguardi della problematica affrontata in questa nota sono essenzialmente quelli contenuti in carte espressamente dedicate al quaternario, prodotte in italia nell’ultimo quindicennio. buona parte di queste carte sono state realizzate con le classiche metodologie fondate sulla litostratigrafia. un esempio, relativo ad un’area prossima a quella considerata, è la carta della conca di rieti (cavinato, 1993). nell’ultimo decennio si sono però diffuse anche procedure cartografiche diverse, fondate sulla adozione delle unità allostratigrafiche o delle unità a limiti inconformi, proposte dal progetto carg. si tratta notoriamente di due tipi di unità stratigrafiche analoghe, in quanto ambedue fondate su limiti corrispondenti a superfici di discontinuità; le differenze riguardano aspetti sostanzialmente formali, quali le caratteristiche di tracciabilità delle stesse superfici, e questioni di priorità terminologica. carte di questo tipo sono quelle dell’apparato glaciale dell’adda (cremaschi et al., 1994), la carta dell’astigiano di boano e forno (1999), la carta della zona del mandriosotto (bini et al., 2001), il foglio “susa” della nuova carta geologica d’italia (direttore del rilevamento delle formazioni superficiali, f. carraro) e la carta dei 111nuovi procedimenti cartografici ... laghi di cornisello della provincia autonoma di trento (rilevatori del quaternario, c. baroni e a. carton). altre carte sono state realizzate sulla base di unità stratigrafiche corrispondenti a singoli eventi sedimentari separati da fasi erosive o, comunque, da fasi di non sedimentazione. si tratta quindi di unità sostanzialmente equivalenti alle unità allostratigrafiche (o a limiti inconformi), in quanto anch’esse necessariamente delimitate da superfici di discontinuità. una carta di questo tipo, relativa ad una zona prossima a quella esaminata, è quella della conca di sulmona (miccadei et al., 1998), la cui struttura informativa può essere illustrata dallo schema dei rapporti stratigrafici contenuto nella carta (fig. 1). esistono poi numerose carte di impronta più decisamente geomorfologica. un esempio abbastanza tipico è quello fornito dalla carta di una parte del gruppo di brenta di petrucci e cavazzini (1992) che, in sostanza, è una carta geomorfologica arricchita da informazioni sulla stratigrafia delle successioni quaternarie. fra le carte di questo tipo per la zona appenninica è da ricordare quella della zona di amatrice di cacciuni et al. (1995) che, su campiture corrispondenti ad unità litostratigrafiche quaternarie, riporta un insieme di dati geomorfologici, fra i quali sono compresi anche i limiti di superfici relitte. orientata ad una maggiore integrazione fra elementi stratigrafici ed elementi geomorfologici è la carta fig. 1 schema dei rapporti stratigrafici della conca di sulmona (da miccadei et al., 1998). schema of the stratigraphic relationships of the sulmona basin (from miccadei et al., 1998). 112 dell’alta valle del volturno di brancaccio et al. (2000), fondata su unità morfo-litostratigrafiche (sensu bosi, 1989a). all’integrazione di elementi stratigrafici e geomorfologici sono ispirate anche altre carte, pubblicate alla fine degli anni ’80 e nei primi anni ’90, riguardanti l’area di montalto di castro (bosi et al., 1990), la conca di fossa (bertini e bosi, 1989 e 1993) e l’alta valle del sangro (galadini e messina, 1993). in queste carte gli elementi stratigrafici e geomorfologici sono rappresentati, rispettivamente, da unità stratigrafiche corrispondenti a singoli eventi deposizionali, e da superfici relitte di erosione o di accumulo; l’integrazione fra questi elementi è stata realizzata ponendoli tutti in un’unica sequenza temporale, sintetizzata in opportuni schemi esplicativi (fig. 2). in una zona come quella appenninica, nella quale l’evoluzione geologica quaternaria si è realizzata per erosione di zone in sollevamento, questi schemi permettono di dettagliare il progressivo approfondimento del reticolo idrografico, arricchendo la griglia temporale nella quale le diverse unità stratigrafiche devono essere collocate. una variante dello schema di figura 2 è quella proposta da basili e bosi (1996) che, sviluppando un precedente lavoro (bosi, 1989a) perfeziona l’integrazione stratigrafia-geomorfologia (v. anche carraro e ferrarino, 1981), considerando anche le superfici di erosione sulle quali si appoggiano le unità stratigrafiche; nel relativo schema morfologico-stratigrafico sono quindi presenti, ordinati in un’unica sequenza numerica, i prodotti degli eventi deposizionali ed erosivi testimoniati nell’area (fig. 3). 33.. mmeettooddii aapppplliiccaattii gli aspetti metodologicamente rilevanti dei criteri seguiti nella realizzazione della carta dell’alta valle dell’aterno sono quelli relativi alla tipologia delle unità utilizzate, alle informazioni geomorfologiche ed alle notazioni strutturali. la scelta delle unità da porre alla base del rilevamento è ispirata ad una radicalizzazione di quella integrazione di elementi geomorfologici e stratigrafici già perseguita in precedenti lavori, citati nel capitolo precedente (bosi, et al., 1990; bosi et al., 1989 e 1995; galadini e messina, 1993; basili e bosi, 1996; bosi e messina, 1997). l’unità di riferimento cartografico è infatti la “unità allo-morfosequenziale” (uam) definita come l’insieme di: una unità stratigrafica (ua), corrispondente al prodotto di una singola fase deposizionale ed assimilabile ad una “unità allostratigrafica” o “unità a limiti inconformi”3; le superfici di erosione e/o di accumulo che la delimitano, assunte come “unità morfosequenziali”4 (um). fig. 2 schema dei rapporti morfo-litostratigrafici della conca di fossa (da bertini e bosi, 1993, modificato). schema of the morpho-lithostratigraphic relationships of the fossa basin (modified after bertini and bosi, 1993). 3 come detto in precedenza i due termini siano sostanzialmente equivalenti nell’ambito della problematica che interessa: la preferenza al termine “allostratigrafico” in questa nota è legata solo a ragioni di semplicità verbale. 4 il termine “unità morfosequenziale” è stato proposto in bosi (1989a), per definire un elemento morfologico che fa parte di una successione cronologicamente ordinata di elementi consimili, evitando il termine “morfostratigrafico” (usato da altri autori) che rappresenta una dubbia commistione di concetti morfologici e stratigrafici. c. bosi, p. messina & m. moro 113 in una situazione, come è quella della zona studiata, nella quale i litosomi sono di regola progressivamente incassati l’uno nell’altro, ogni unità “allo-morfosequenziale” viene ad essere delimitata verso il basso dalla superficie d’erosione sepolta sulla quale giace l’unità allo-stratigrafica e, verso l’alto, da una o più superfici relitte. unità così definite configurano una perfetta parità di rango fra eventi erosionali ed eventi deposizionali, in una prospettiva che considera tanto gli uni quanto gli altri ugualmente determinanti nei riguardi dell’evoluzione geologica. questa parità ha anche risvolti concettuali in quanto cambia il modo di considerare le superfici che delimitano le unità stratigrafiche: l’identità di queste superfici non risiede più nel loro ruolo di limitare litosomi, ma nel fatto di rappresentare effetti di specifiche fasi morfogenetiche. e’ evidente che le unità allo-morfosequenziali non possono essere considerate unità stratigrafiche, ma si configurano come unità di rappresentazione cartografica corrispondenti agli effetti degli eventi deposizionali ed erosivi che hanno caratterizzato una specifica fase dell’approfondimento del reticolo. l’insieme delle “unità allo-morfosequenziali” può essere descritto con riferimento ad una successione unitaria, schematizzabile da un opportuno schema dei rapporti stratigrafico-morfologici (fig. 4). in questo schema possono trovare razionale collocazione anche unità morfosequenziali costituite da superfici relitte scolpite nel substrato pre-quaternario, che possono essere assimilate ad unità allo-morfosequenziali per le quali l’unità allostratigrafica abbia spessore nullo. per quanto riguarda le informazioni geomorfologiche riportate sulla carta, esse sono limitate a quelle relative a tutte le superfici relitte (d’erosione e di accumulo) osservabili nel paesaggio. non si è ritenuto opportuno riportare elementi geomorfologici diversi da queste superfici sostanzialmente per tre motivi distinti. il primo è la ovvia necessità di non complicare la carta con troppi graficismi. il secondo motivo discende dal fatto che molti dei dati geomorfologici abitualmente riportati nelle carte geologiche sono di fatto sovrabbondanti rispetto al contenuto informativo proprio di una carta geologica. nel caso di conoidi, morene, ecc. l’informazione geomorfologica aggiunge infatti ben poco ad una corretta informazione sulla litologia e sull’ambiente di sedimentazione5, mentre in altri casi (doline, dune, allineamenti di dune ecc.) le informazioni possono addirittura essere dedotte dalle carte topografiche al 25.000. fig. 3 schema morfo-litostratigrafico dell’area di monterotondo (da basili e bosi, 1996). morpho-litostratigraphic schema of the monterotondo area (from basili and bosi, 1996). 5 nel caso del conoide, ad esempio, una volta che esso sia rappresentato da un colore che ne esprima queste caratteristiche e ne precisi l’estensione, aggiungere il simbolo geomorfologico equivale di fatto a dire che un conoide ... ha la forma di un conoide. l’eventuale conservazione dell’abituale simbolo di conoide (come nella carta oggetto di questa nota) può avere una sua giustificazione solo come espediente per non cartografare il limite preciso dei sedimenti appartenenti al conoide. nuovi procedimenti cartografici ... 114 il terzo, e più importante, motivo è rappresentato dal fatto che le indicazioni geomorfologiche usualmente cartografate, configurano un set di informazioni avulso dal contesto stratigrafico-strutturale delle carte geologiche. si tratta infatti di indicazioni relative a forme presenti nel paesaggio attuale, senza che, di regola, ne sia indicata la collocazione cronologica, né i rapporti con le unità stratigrafiche riconosciute. seguire la prassi usuale equivale quindi a far coesistere due insiemi di informazioni sostanzialmente disomogene, a tutto scapito della struttura logica della carta. d’altra parte, anche l’eventuale precisazione in termini cronologici delle usuali notazioni geomorfologiche appare scarsamente soddisfacente. un esempio a questo proposito è quello del terrazzo il cui ciglio fornirebbe informazioni di fatto superate dalla rappresentazione cartografica della spianata sommitale del terrazzo. la delimitazione di questa spianata costituisce anzi un’informazione più completa dell’indicazione del ciglio del corrispondente terrazzo in quanto riguarda anche i casi di spianate prive di un ciglio morfologicamente definito. l’unico modo in cui la rappresentazione del ciglio fornirebbe informazioni più dettagliate sarebbe quello di rappresentare il ciglio come intersezione di una superficie sommitale con le scarpate che la delimitano, precisando l’età di ciascuna di esse; soluzione questa che risulta estremamente complessa e difficilmente realizzabile data la diacronicità delle scarpate. in relazione alle notazioni strutturali si è ritenuto utile inserire due informazioni, non considerate nelle usuali carte geologiche. la prima riguarda la cronologia della deformazione che è stata valutata in modo molto schematico, nei limiti concessi dalla situazione stratigrafico-strutturale dell’area cartografata. la seconda riguarda la fonte delle valutazioni cartografate e consiste nel mettere in evidenza quelle fondate su elementi decisamente interpretativi, quali le particolarità geomorfologiche potenzialmente riconducibili a dislocazioni tettoniche. 44.. iill qquuaatteerrnnaarriioo ddeellll’’aallttaa vvaallllee ddeellll’’aatteerrnnoo 44..11 lliinneeaammeennttii ggeeoollooggiiccii l’area cartografata si estende a w della catena del gran sasso, fra il versante sw del m. marine ed il margine ne del gruppo del m. giano. si tratta di un’area costituita da un substrato marino giurassico-miocenico variamente corrugato ricoperto da sedimenti continentali di varia facies ed età. i dati geologici disponibili per quest’area sono quelli riportati in bosi (1975), blumetti (1995), bagnaia et al. (1996), blumetti et al. (1996), basili et al. (1997), basili et al. (1999), messina et al. (2001) l’area è costituita da un importante fondovalle, che si evolve fino a divenire una ampia conca pianeggiante, e da un sistema di versanti calcareo-dolomitici (più raramente calcareo-marnosi) solcati da incisioni variamente pronunciate. in prossimità dei fondovalle sono estesamente presenti sedimenti fluviali, talora terrazzati, mentre sui versanti i sedimenti quaternari sono rappresentati solo da lembi di depositi di versante. l’area cartografata (figg. 5 e 6) rappresenta quindi un campione abbastanza significativo delle tipiche conche intermontane dell’appennino laziale-abruzzese. fig. 4 schema dei rapporti morfologico-stratigrafici dell’alta valle dell’aterno. schema of the morpho-stratigraphic relationships of the upper aterno valley. c. bosi, p. messina & m. moro 44..22 llaa ssuucccceessssiioonnee aalllloo--mmoorrffoosseeqquueennzziiaallee applicando la metodologia descritta nel capitolo 3, è stata delineata una successione di unità allo-morfosequenziali (uam), in ciascuna delle quali elementi stratigrafici ed elementi morfologici si integrano in vario modo. il limite inferiore di tutte le uam è costituito da una superficie di erosione scolpita in terreni di varia collocazione stratigrafica, in conseguenza del progressivo e costante incassamento dei litosomi l’uno nell’altro. questa superficie non ha una esplicita rappresentazione anche se è comunque definita nella carta; essa coincide infatti con il limite fra i colori delle diverse uam, corrispondente all’intersezione delle superfici d’erosione alla base delle diverse unità con l’attuale superficie topografica. il limite superiore di una uam può essere rappresentato dalla superficie di accumulo dell’unità allostratigrafica o da una spianata d’erosione che la tronca, o ad una combinazione delle due. come già detto in 3.3, nella successione allomorfosequenziale sono state inserite anche superfici relitte scolpite direttamente sul substrato, assunte come unità morfo-sequenziali. come si è già detto, queste unità, rilevanti in quanto testimonianze del progressivo approfondimento del reticolo idrografico, sono assimilabili ad unità allo-morfosequenziali per le quali la unità allostratigrafica abbia spessore nullo. la rappresentazione più indicativa della successione allo-morfosequenziale è quella dello schema dei rapporti morfologico-stratigrafici di fig. 4. in questo quadro seguendo la procedura già indicata in basili e bosi (1996) le unità stratigrafiche e le unità morfosequenziali sono state numerate progressivamente a partire dalla superficie di accumulo dei depositi alluvionali di fondovalle (1) alla superficie d’erosione alla base dell’unità stratigrafica più antica (27). a ciascuno di questi numeri è associata una sigla che chiarisce la natura del corrispondente elemento stratigrafico o morfologico (li=litosoma; se=superficie di erosione; sa=superficie di accumulo). questi numeri sono stati utilizzati anche per la denominazione delle diverse uam: ciascuna di queste unità è infatti definita da due numeri corrispondenti all’elemento (morfologico o stratigrafico) rispettivamente più recente e più antico fra quelli rappresentati nella stessa unità. si può far notare che questo tipo di denominazione ha il vantaggio di evitare il lungo elenco di termini (alloformazione o sintema o formazione di ….., superficie di …..) che sarebbe stato necessario adottare se si fosse applicata la usuale terminologia stratigrafica con i suoi riferimenti toponomastici; essa possiede inoltre una immediata evidenza in termini di cronologia relativa. complessivamente la successione allo-morfosequenziale è costituita da 27 (figg. 4 e 5) unità le cui caratteristiche sono sintetizzate in quanto segue, a partire dalla unità più antica. unità allo-morfosequenziale 26/27 l’ua 26 è costituita da conglomerati ad elementi carbonatici poco arrotondati e da alternanze di livelli ghiaiosi con ciottoli arenacei e calcarei e da livelli sabbioso-limosi. l'intera successione è basculata, con inclinazioni degli strati che raggiungano in alcuni casi i 20°. unità morfosequenziali 23-24-25 sono costituite da lembi di spianate di erosione rimodellate, scolpite su substrato e sviluppate a quote comprese tra 750 e 850 m. unità allo-morfosequenziale 21/22 l’ua 21 è costituita da ghiaie fluviali, talora sabbioso-limose, con elementi generalmente ben arrotondati (dimensioni variabil i f ino a 20 centimetri). localmente sono intercalati strati sabbioso–limosi con livelli ossidati probabilmente legati a variazioni del livello di falda. l’immersione della stratificazione varia tra s e w, con inclinazioni che raggiungono i 10°. l’embricatura dei ciottoli indica una direzione di trasporto da nw a se, mediamente parallela con il corso attuale dell’aterno. nella parte alta dell’unità è presente una superficie di erosione coperta da ghiaie fluviali appartenenti a successivi cicli sedimentari non distinguibili cartograficamente. unità allo-morfosequenziale 18/20 l’ua 19 è costituita da una successione di limi sabbioso-argillosi ben stratificati, a giacitura generalmente sub-orizzontale, a luoghi laminati, che rappresentano un deposito di fine ciclo fluviale passante verso l’alto ad ambiente lacustre. l’unità è delimitata a tetto dalla superficie di accumulo (um 18) ben conservata e riconoscibile a nw di barete a quota 780-800. unità morfosequenziale 17 e’ costituita da un insieme di lembi di superfici di erosione riconoscibili a nord di s. vittorino a quota 710800 m. le superfici, probabilmente riconducibili ad un episodio di spianamento sostanzialmente unitario, interessano in modo indifferenziato sia il substrato calcareo che l’ua 26 e l’ua 21. unità allo-morfosequenziale 14/16 l’ua 15 è costituita da un esiguo spessore (sino a 10 metri circa) di sabbie fini limose con rari ciottoli calcarei poco arrotondati. l’ambiente di sedimentazione è di tipo fluviale di bassa energia. l’unità è delimitata a tetto dalla corrispondente superficie di accumulo (um14) conservata in lembi rimodellati nella zona di cavallari. lateralmente um14 corrisponde ad una spianata di erosione che interessa sia il substrato calcareo che l’ua 21, ad una quota compresa tra 690 e 720 m circa. unità allo-morfosequenziale 11/13 l’ua 12 è costituita da livelli sub-orizzontali di ghiaie fluviali, variamente sabbiose, con elementi molto arrotondati, e da lenti di sabbie che contengono abbondante materiale di origine vulcanica (piccole scorie, pirosseni, biotite, ecc.). l’unità è delimitata a tetto dalla superficie di accumulo (um 11) conservata in lembi a quote 670-715 nella zona compresa tra prato lagone e prato dell’agora. unità morfosequenziale 10 e’ costituita da lembi di una spianata di erosione sviluppati a quote 665-675 e scolpiti sull’ua 12 nell’area compresa tra c.le visconti e pratiglio. 115nuovi procedimenti cartografici ... 116 fig. 5 stralci e legenda della carta geologica del quaternario dell’alta valle dell’aterno. la descrizione delle varie unità è riportata nel testo. base cartografica della regione abruzzo (aut. giunta reg. serv. inf. terr. e telem. prot. 2095 del 19/06/2003). parts and legend of the quaternary geological map of the upper aterno valley. see the text the description of the allo-morphosequential units. topographic map of the regione abruzzo. c. bosi, p. messina & m. moro unità allo-morfosequenziale 7/9 l’ua 8 è costituita da ghiaie sabbioso-limose fluviali ed è delimitata a tetto dalla superficie di accumulo (um 7) conservata in lembi a quote 670-680. unità allo-morfosequenziale 4/6 l’ua 5 è rappresentata da successioni limososabbiose con livelli di piccoli clasti sub-arrotondati ed è delimitata a tetto da una superficie, in parte di accumulo ed in parte di erosione (um 4), ben riconoscibile nella zona di scentella. unità allo-morfosequenziale 1/3 e unità allo-morfosequenziale 1/3 bis l’ua 2 è rappresentata da sedimenti fluviali sabbioso-ghiaiosi del fondovalle attuale e da coltri colluviali che ad esso si raccordano, nonché da depositi di versante e da depositi di conoide. l’unità è delimitata a tetto dalla superficie di accumulo (um 1), non cartografata, che corrisponde all’attuale fondovalle del fiume aterno. la successione allo-morfosequenziale descritta 117 fig. 6 ubicazione degli stralci cartografici di figura 5. location of the geological maps of figure 5. nuovi procedimenti cartografici ... non comprende tutte le unità stratigrafiche riconosciute: per mancanza di elementi di valutazione non è stato infatti possibile inserire esattamente in essa le “brecce di s. antonio”, le “brecce di s. marco” e l’ “allogruppo di arischia”. nell’allogruppo di arischia sono state incluse successioni litologiche di vario tipo (da limose a sabbiosoghiaiose) e di varia facies (da depositi di versante a sedimenti lacustri) sporadicamente conservate sul versante sinistro della valle. in queste successioni sono verosimilmente rappresentate più unità allostratigrafiche, delle quali non è però possibile indicare né le caratteristiche litologiche, né i loro reciproci rapporti. da segnalare anche che non è stato possibile precisare i rapporti fra la successione sopra delineata ed alcune unità morfosequenziali, rappresentate da lembi di spianate d’erosione molto rimodellate, osservate nella zona di cagnano amiterno. 44..33 rriiffeerriimmeennttii ccrroonnoollooggiiccii nell’area non sono state rinvenute faune o flore fossili di interesse cronologico. le valutazioni al riguardo sono quelle che possono essere indicate sulla base di alcune determinazioni 14c, di correlazioni a scala regionale e di misure di paleomagnetismo (bosi et al., in stampa a; messina et al., 2001). le determinazioni 14c riguardano le “brecce di s. antonio” per le quali sono state calcolate età calibrate di 31.710 ± 760 e 23.330 ± 300 anni bp (galadini e galli, 2000). le correlazioni a scala regionale inducono ad attribuire la ua 26 al più antico degli eventi deposizionali continentali noti, riferito ad un generico pliocene (primo evento deposizionale di bosi e messina, 1991; bosi et al., in stampa a). sulle stesse basi le ua 21 e 19 possono essere correlabili con il secondo e terzo evento deposizionale riferibili rispettivamente al pleistocene inferiore ed al pleistocene medio (bosi et al.; in stampa a). queste correlazioni sono in varia misura avvalorate da determinazioni di paleomagnetismo (messina et al., 2001) che indicano per la ua 26 una polarità normale riferibile ad una età maggiore di 1.170 ka, per la ua 21 una polarità inversa (matuyama) e per la ua 19 una polarità diretta (bhrunes). le “brecce di s. marco sono verosimilmente correlabili con le “brecce di f. vedice” (bosi, 1989b; bertini e bosi, 1989) e con le “brecce di bisegna” di bosi e messina (1990) che rappresentano un importante riferimento per tutto l’appennino laziale-abruzzese (bosi e messina, 1990; bosi e messina, 1991; bosi et al., 1995; bosi et al., in stampa, b) le determinazioni di paleomagnetismo confermano questa attribuzione, peraltro già avvalorata con lo stesso metodo da d’agostino et al. (1997). 44..44 eelleemmeennttii ssttrruuttttuurraallii coerentemente con il tema della carta sono stati cartografati solo gli elementi strutturali ad attività quaternaria considerati nella prospettiva delineata nel capitolo 3. tenuto conto di questa prospettiva e delle caratteristiche dell’area cartografata le faglie sono state classificate nel modo seguente: faglie ad attività documentata almeno sino alla parte alta del pleistocene superiore e loro ipotetici prolungamenti; faglie ad attività genericamente quaternaria e loro ipotetici prolungamenti; faglie probabili ad attività quaternaria, desunte solo da elementi morfologici. la faglia più importante è quella al piede del versante sw di m. marine che ha come espressione morfologica alcune evidenti scarpate di faglia che interessano anche terreni deposti in tempi storici (moro et al., 2002). un’altra faglia è quella presente lungo la direttrice s. marco s. vittorino che disloca le brecce di s. marco; essa costituisce il prolungamento verso nw della importante faglia del m. pettino la cui attività, al di fuori dell’area rilevata, si estende almeno fino al pleistocene superiore (galadini, 1999). altre piccole faglie sono quelle cartografate a ne di san vittorino, dedotte solo dalla presenza di alcune deboli e larghe depressioni ragionevolmente non riconducibili a fenomeni puramente erosivi. l’esistenza di queste faglie è stata di conseguenza ritenuta solo probabile. altre faglie di attribuzione incerta sono quelle osservate in una cava a w di cona della croce, non cartografate per la modesta entità del rigetto (pochi decimetri). altri elementi strutturali sono rappresentati da basculamenti nei depositi della ua26 a nord ed a ovest di barete. nella zona a sud della stessa località, la superficie um17 presente a tetto di ua21 è stata probabilmente basculata verso sse, in direzione cioè della zona di massima apertura del bacino di arischia. 55.. ccoonnssiiddeerraazziioonnii ccoonncclluussiivvee la carta geologica dell’alta valle dell’aterno è stata realizzata sulla base di criteri che corrispondono ad una radicalizzazione di alcune proposte metodologiche già pubblicate in precedenza, ispirate ad una stretta integrazione di informazioni stratigrafiche e geomorfologiche. questa integrazione è stata realizzata adottando particolari unità di riferimento, rappresentate da “unità allo-morfosequenziali” assunte come unità cartografiche a carattere misto, stratigrafico-morfologico, e, talora, da “unità morfosequenziali” rappresentate da superfici d’erosione relitte scolpite sul substrato, concettualmente riconducibili alle prime. queste unità non si configurano come unità stratigrafiche, ma come unità di rappresentazione cartografica, corrispondenti a particolari insiemi di elementi stratigrafici (unità allostratigrafiche o a limiti inconformi) e geomorfologici (superfici di erosione e di accumulo). e’ da osservare che in queste unità le superfici di erosione non sono più considerate solo come limiti di unità stratigrafiche, ma come effetti di specifici eventi geologici. nel caso dell’area in esame, caratterizzata dal progressivo incassamento di forme e litosomi, questi insiemi corrispondono alle principali tappe del progressivo approfondimento del reticolo che ha dato origine al paesaggio attuale. l’adozione di unità così definite sembra quindi avere una più spiccata valenza nei riguardi della ricostruzione dell'evoluzione geologica in tutti i suoi diversi aspetti. una delle differenze fra la carta così ottenuta e le 118 c. bosi, p. messina & m. moro usuali carte geologiche risiede nel fatto che le informazioni morfologiche non sono semplicemente aggiunte a quelle stratigrafiche, ma integrate con esse, in una prospettiva che considera in modo del tutto paritario fatti deposizionali ed erosivi, con tutti i loro effetti morfogenetici. questa integrazione, oltre a delimitare le superfici relitte, ne specifica infatti la collocazione cronologica relativa e ne precisa i rapporti genetici con le unità stratigrafiche ad esse sottostanti. di conseguenza, viene a cambiare la stessa struttura informativa della carta geologica. mentre le carte usuali corrispondono in sostanza ad una zonazione riferita ai prodotti degli episodi deposizionali (o comunque litogenetici) che si sono succeduti nel tempo, sulla quale sono sovrapposte notazioni geomorfologiche relative a forme riconoscibili nel paesaggio attuale, la carta oggetto di questa nota propone una zonazione riferita ai prodotti di particolari insiemi di eventi deposizionali ed erosivi, corrispondenti a diverse fasi dell’evoluzione geologica. e’ da osservare che la procedura adottata sembra fornire una adeguata soluzione al problema, formalmente ancora irrisolto, del rapporto fra dettaglio delle scansioni stratigrafiche e scala della carta. si tratta di un problema che viene affrontato secondo criteri propri delle diverse scuole. in qualche caso la soluzione viene ottenuta in modo riduttivo adeguando semplicemente le scansioni stratigrafiche alla scala della carta, nel senso che la scansione è tanto minore quanto minore è la scala. gli inconvenienti che possono derivare da una soluzione di questo tipo sono rappresentati sia dalla difficoltà di confrontare carte di operatori diversi e sia, soprattutto, dalla impossibilità di ricavare ricostruzioni dettagliate dell’evoluzione geologica quaternaria. una soluzione più soddisfacente è invece quella che nasce dalla applicazione che è stata fatta in relazione alle unità allostratigrafiche. se, come nel caso della carta in esame, queste unità si riferiscono al prodotto di un singolo evento deposizionale, il problema di restituire alla scala della carta i risultati ottenuti si riduce di fatto a quello di distribuire in gruppi le unità individuate, operazione che può essere eseguita con varie modalità senza nulla togliere alle conoscenze che vengono espresse nella rappresentazione cartografica. la zona alla quale è stata applicata la metodologia cartografica descritta può essere considerata sufficientemente rappresentativa di tutta la parte assiale della catena appenninica nella quale i litosomi quaternari sono tutti continentali e, di regola progressivamente incassati l’uno nell’altro. l’eventuale estensione del procedimento ad aree geologicamente diverse, quali le fasce periappenniniche nelle quali sono presenti anche successioni quaternarie di ambiente marino, non dovrebbe porre particolari problemi. dovrebbe infatti essere sufficiente ammettere che le unità allo-morfosequenziali possano avere una struttura più complessa, rappresentata ad esempio da più unità allostratigrafiche sovrapposte e da unità morfosequenziali interne alla successione stratigrafica. 66.. bbiibblliiooggrraaffiiaa bagnaia r., blumetti a.m., de luca g., gorini a., marcucci s., marsan p., milana g., salvucci r. e zambonelli e. (1996) morfotettonica dei rilievi a nord della conca aquilana. il quaternario, 99 (1), 287-292. basili r. e bosi c. (1996) morfo-litostratigrafia dell'area romana in sinistra tevere. il quaternario 99 (1), 273-279. basili r., bosi c. e messina p. (1997) la tettonica quaternaria dell 'alta valle del f. aterno (appennino centrale) desunta dall'analisi di successioni di superfici relitte. il quaternario, 1100 (2), 621-624. basili r., bosi c. e messina p. (1999) paleo-landsurfaces and tectonics in the upper aterno valley (central apennines). z. geomorph. n.f., suppl.bd. 111188, 17-25. bertini t. e bosi c. (1989) carta geologica della zona di barisciano s. demetrio dei vestini (l’aquila) – in: società geologica italiana, guida all’escursione su elementi di tettonica pliocenico-quaternaria nell’appennino laziale-abruzzese. esagrafica, roma. bertini t. e bosi c. (1993) la tettonica quaternaria della conca di fossa (l'aquila). il quaternario, 66 (2), 293-314. bini a., felber m., pomicino n. e zuccoli l. (2001) geologia del mandrisiotto (canton ticino, svizzera): messiniano, pliocene e quaternario. berichte des bundesamt für wasser und geologie / rapporti dell'ufficio federale delle acque e della geologia bwg/ufaeg, 1-459. blumetti a. m. (1995) neotectonic investigations and evidence of paleoseismicity in the epicentral area of the january-february 1703, central italy, earthquakes. in: serva l. e slemmons d. b. (eds.), a.e.g. special publication no. 6, perspective in paleoseismology, 83-100. blumetti a. m., cavinato g. p. e tallini m. (1996) evoluzione plio-quaternaria della conca di l 'aquila-scoppito: studio preliminare. i l quaternario, 99 (1), 281-286. boano p. e forno m.g. (1999) la successione “villafranchiana” nell’area di castelnuovo don bosco (asti) – il quaternario, 1122 (2), 161-194. bosi c. (1975) osservazioni preliminari su faglie probabilmente attive nell'appennino centrale. boll. soc. geol. it., 9944, 827-859. bosi c. (1989a) considerations and proposals on morpho-pedo-lithostratigraphic units in quaternary studies. il quaternario, 22, 3-9. bosi c. (1989b) tentativo di correlazione fra le successioni plio-pleistoceniche in: guida all'escursione “elementi di tettonica pliocenico-quaternaria ed indizi di sismicità olocenica nell'appennino lazialeabruzzese. esagraphica, roma bosi c. e messina p. (1990) elementi di stratigrafia neogenico-quaternaria tra il fucino e la valle del giovenco (l'aquila). mem. descr. carta geol. it., 3388, 85-96. bosi c. e messina p. (1991) ipotesi di correlazione fra successioni morfo-litostratigrafiche plio-pleistoceniche nell'appennino laziale-abruzzese. studi geologici camerti, crop 11, 275-263. bosi c. e messina p. (1993) valutazione della cartografia geologica italiana per la parte relativa al quaternario. soc. geol. it., 112, 869-876. 119nuovi procedimenti cartografici ... bosi c. e messina p. (1997) cartografia geologica di nuova generazione per il quaternario continentale e marino costiero. convegno nazionale della f.i.s.t. geoitalia 1997 1° forum italiano di scienze della terra bellaria (rimini), 5-9 ottobre 1997. bosi c., galadini f. & messina p. (1995) stratigrafia plio-pleistocenica della conca del fucino. il quaternario, 88 (1), 83-94. bosi c., galadini f., giaccio b., messina p., sposato a. (in stampa, a) plio-quaternary continental deposits in the latium-abruzzi apennines: the correlation of geological events across different intermontane basins. il quaternario. bosi c., messina p. & sposato a. (1989) la depressione del salto. in "elementi di tettonica pliocenicoquaternaria ed indizi di sismicità olocenica nell'appennino laziale-abruzzese". guida all'escursione della s. g. i., 89-96. esa grafica. bosi c., messina p. e moro m. (in stampa, b) carta geologica del quaternario dell'alta valle dell'aterno (italia centrale). il quaternario. bosi c., palieri l. e sposato a. (1990) carta geologica della fascia costiera fra il f. fiora ed il f. marta (lazio settentrionale) – aiqua, guida all’escursione sui terrazzi e linee di costa del litorale del lazio settentrionale. esagrafica, roma. brancaccio l., di crescenzo g., rosskopf c., santangelo n. e scarciglia f. (2000) carta geologica dei depositi quaternari e carta geomorfologica dell’alta valle del f. volturno (molise, italia meridionale). note illustrative. il quaternario, 13 (1/2), 81-94. c.n.r., commissione per la cartografia geologica e geomorfologica (1992) carta geologia d'italia 1:50.000 guida al r i levamento. servizio geologico nazionale, quaderni, serie iii, 1. cacciuni a., centamore e., di stefano r. e dramis f. (1995) evoluzione morfotettonica della conca di amatrice. studi geologici camerti, volume speciale 1995/2, 95-100. carraro f. e ferrarino g. (1981) tentativi di realizzazione di un nuovo tipo di carte morfologiche: le carte morfo-stratigrafiche. atti xvii conv. naz. ass. it. di cartografia, venezia. cavinato g. p. (1993) recent tectonic evolution of the quaternary deposits of the rieti basin (central apennines, italy): southern part. geologica romana, 2299, 411-434. cremaschi m., bini a., ferliga c., marchetti m., ravazzi c. e rossi s. (1994) montagna e pianura: i processi geologici recenti e gli effetti sull'ambiente. in: storia economica e sociale di bergamo: i caratteri originali della bergamasca. fondazione per la storia economica e sociale di bergamo. istituto di studi e ricerche, 109 –135. d'agostino, n., speranza, f. e funiciello, r. (1997) le "brecce mortadella" dell'appennino centrale: primi risultati di stratigrafia magnetica. il quaternario, 10 (1), 385-388. galadini f. (1999) pleistocene change in the central apennine fault kinematics, a key to decipher active tectonics in central italy. tectonics, 1188, 877-894. galadini f. e galli p. (2000) active tectonics in the central apennines (italy) – input data for seismic hazard assessment. natural hazard, 2222, 225-270. galadini f. e messina p. (1993) stratigrafia dei depositi continentali, tettonica ed evoluzione geologica quaternaria dell'alta valle del f. sangro (abruzzo meridionale). boll. soc. geol. it., 111122, 877-892. messina p., moro m. e speranza f. (2001) primi risultati di stratigrafia magnetica su alcune formazioni continentali dell'alta valle dell'aterno (italia centrale). il quaternario, 1144, 167-172. miccadei e., barberi r. e cabinato g.p. (1998) la geologia quaternaria della conca di sulmona (abruzzo, italia centrale). geologica romana, 3344, 59-86. moro m., bosi v., galadini f., galli p., giaccio b., messina p. e sposato a. (2002) analisi paleosismologiche lungo la faglia del m. marine (alta valle dell'aterno): risultati preliminari. il quaternario, 1155, 267-278. petrucci f. e cavazzini r. (1992) il quaternario del trentino sud-occidentale. i carta geomorfologica e dei depositi quaternari tra la val rendeva e cima tosa castel dei camosci (gruppo di brenta). il quaternario, 55(2), 163-172. 120 ms. ricevuto il 14 marzo 2003 testo definitivo ricevuto il 13 maggio 2003 ms. received: march 14, 2003 final text received: may 14, 2003 c. bosi, p. messina & m. moro available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 37 (1), 2024, 5-27 2009) and seattle (williams, 2015). geomorphological mapping in urban areas must take into account the wide distribution of anthropogenic landforms and deposits, in addition to the natural ones (de beer et al., 2012; luberti et al., 2019). the distinction of natural/anthropogenic landforms is often difficult and requires an integrated approach by combining geomorphological surveys with historical geographic analysis (faccini et al., 2020). many studies have been done on the urban areas of river cities, such as rome on the tiber r. (del monte et al., 2016; luberti, 2018; mancini et al., 2018; luberti et al., 2019; vergari et al., 2020), alessandria at the tanaro-bormida confluence (mandarino et al., 2020), pavia on the ticino r. (dall’aglio et al., 2011; pelfini et al., 2021), padua on the bacchiglione and the palaeobrenta rivers (mozzi et al., 2010; 2017; ), and ferrara at https://doi.org/10.26382/amq.2024.01 1. introduction research on urban geology has advanced in recent years concerning both the scientific approach (see brandolini et al., 2021, and references therein) and the use of urban subsoil for applicative purposes (del monte, 2018; del monte et al., 2016; agnesi, 2021). additionally, the effect of anthropic interventions, such as the accumulation of landfill deposits and the carrying out of morphological modifications, was extensively investigated for the main urban areas e.g. for rome (luberti et al., 2019), london (forster, 1997), paris (thierry et al., 2009), bordeaux (bourgine et al., 2009), bucharest (ciugudean-toma & stefanescu, 2009), montreal (boyer et al., 1985), denver (costa & bilodeau, 1982), kansas city (hasan et al., 1988), cairo (shata, 1988), hong kong (burnett, 1988), são paulo (do val et al., anthropogenic morphological modifications in turin along the po, sangone and dora riparia rivers (nw italy) m. gabriella forno, franco gianotti, gaia sartori earth science department, university of turin, turin, italy. corresponding author: m. gabriella forno <gabriella.forno@unito.it> abstract: geomorphological mapping in urban areas must address the wide distribution of anthropogenic landforms and deposits in addition to the natural ones. consequently, an integrated scientific approach, by combining field surveys and subsoil data with the use of historical documents, is necessary to recognize the main anthropogenic modifications of the natural landscape over time. recent field research concerning the morphology and shallow subsoil stratigraphy of turin, especially through the study of several boreholes, has led to the recognition of various anthropogenic modifications of the turin natural landscape that have occurred in the last four centuries. moreover, the examination of ancient papers and historical maps, with reported sectors in which the morphology of turin appears different from the current one, indicated some evident, partly anthropogenic, modifications. anthropogenic changes deduced essentially from ancient topographic maps have addressed the path of riverbeds, e.g. the stabilisation of the sangone r. meander near the mirafiori castle, the setting and artificial cut of the nichelino meander, the shift of the confluence between po and sangone rivers and the artificial cut of the wide meanders of the dora riparia r. near its confluence with the po r., to allow the expansion of the monumental cemetery. other significant anthropogenic river modifications that have been difficult to identify concern the filling of several ancient tributary incisions on the left of the po r., which have now completely disappeared. ancient quarries associated with brick-kilns lowered the surface through the removal of the clayey silt overbank cover of the turin unit in wide sectors of southern turin, rivalta and beinasco, as observed by field survey. areas in which the landfill has substantial thickness and extension such as to simulate natural river terraces, e.g. the long stretch between the palazzo del lavoro and the balbis bridge, were also recognized by observing geognostic cores coupled with the radiocarbon dating of the underlying fluvial deposits. surface surveys alone are sufficient to recognize the areas involved by substantial anthropic interventions when they are characterized by hummocky morphology such as in the valentino park and the cavour garden. finally, anthropogenic modifications deduced essentially from historical reports consist of the construction and filling of the michelotti canal along the po right riverside. the progressive extension of turin was closely related to the natural evolution caused by geomorphic agents (above all erosional and/or depositional processes carried out by watercourses) but also by anthropogenic modifications of the topographic surface (excavations and/or fillings). the investigated anthropogenic modifications of the turin landscape are therefore useful to both the scientific approach and the use of urban subsoil. keywords: urban geology, urban geomorphology, anthropogenic modifications, anthropogenic deposits, turin. the po-reno confluence (stefani & zuppiroli, 2010; stefani et al., 2020), that evidence significant morphological and stratigraphic modifications due to human activities. other case studies regard cities located in an ancient transitional environment, such as pisa (martini et al., 2010; sarti et al., 2012; bini et al., 2015) and the roman luna (bini et al., 2012) or in current alluvialcoastal environments such as rimini (guerra et al., 2020), chiavari-lavagna (roccati et al., 2020), rapallo (brandolini et al., 2020), genoa (faccini et al., 2020) and cagliari (porta et al., 2020). river cities were mostly founded on morphological highlands, but their expansion onto lowlands corresponding to alluvial plains since ancient times (rome), or exclusively in modern times (pavia, turin), has led to live with the risk due to river floods (e.g., the case of nichelino and moncalieri south of turin, giulietto & luino, 2006; see also brandolini et al., 2020; roccati et al., 2020; mandarino et al., 2021). in particular, ancient turin (from roman to medieval ages up to the risorgimento) was built between 245238 m asl in a flood-free area located on the distal sector of a wide proglacial outwash plain highly, safely resting above the active bed of the po r. (209 m asl). this 10-30 m high upland is deeply cut by the rivers through a set of entrenched fluvial terraces (fig. 1). the recent morphological and geological studies regarding both the landscape of turin and its subsoil stratigraphy suggested focusing attention on recognition and study of the anthropogenic modifications of the natural morphology (associated to small change of the shallow subsoil stratigraphy) that occurred in recent years for this area, especially in the sectors close to the riverbanks of the po and its tributaries dora riparia and sangone. a recent geomorphological survey of turin, finalized to produce its detailed geological map (forno & gianotti, 2021), allowed us to recognize various sectors in which the current morphology appears widely modified compared to the natural morphology, e.g. sectors in which the topographic surface looks higher or lower than the surrounding areas. in addition to the field survey, the observation of cores related to some tens of boreholes, coupled with radiometric dating, enabled the evaluation of the presence and thickness of important landfills, which extensively cover the natural morphology (forno et al., 2022). several pieces of evidence were also derived from the examination of historical maps related to the last four centuries, that reported some sectors in which the morphology of turin appeared different from its current morphology, or the path of watercourses changed over time, confirming some important, partly anthropogenic, modifications. moreover, numerous historical reports have also referred to substantial anthropogenic modifications of the turin landscape and shallow subsoil stratigraphy by human activity (lavazza, 2017; mongini & oddone, 2020). 2. methods this research used an interdisciplinary method focused on various sources of data. the recent geomorphological map of turin, which required a detailed geological and morphological survey of the turin plain, allowed us to identify several anthropogenic modifications (forno & gianotti, 2021). the quaternary fluvial succession in this map is distinguished into different stratigraphic units based on allostratigraphic and morphostratigraphic criteria. these units consist of erosive landforms (i.e. erosional terraces) reported as morphological units, and depositional bodies formed by accumulation of fluvial sediments (i.e. depositional terraces) referred to as morphological unconformity-bounded stratigraphic units (ubsus) (salvador, 1994). the different units are defined according to the sedimentary facies of the deposits, soil weathering degree and associated terrace morphology (elevation, lateral continuity and morphology). in the text several considerations about the subsoil refer to previous researches, that include the study of 34 boreholes drilled in 2020 by smat (società metropolitana acque torino) along the new sewer collector and 6 cores drilled in 2019 in the valentino park (forno et al., 2022), in addition to 126 stratigraphic logs collected in the archive of the regional environmental agency (arpa, forno & gianotti, 2021). moreover, historical maps of different ages, including ancient topographic maps from 1640 (listed in lupo, 1989) and more recent geological maps (bortolami et al., 1969; festa et al., 2009) allowed us to deduce some anthropogenic modifications that involved the natural surface. locally, also ancient aerial photos testified some modifications of the turin surface. finally, historical papers report topographic modifications that are related to the use of various sectors of turin, essentially for the construction of buildings. all the areas with anthropogenic modifications have been checked in the field and they have been reported on the carta tecnica regionale (ctr) of the piedmont region at the scale 1:10,000. 3. geological setting of turin the turin plain consists of a narrow band between the northwestern alps and the turin hill. the alps are formed by ancient palaeozoic and mesozoic metamorphic rocks that were highly deformed by the alpine orogeny. the turin hill consists of a tertiary marine sedimentary succession formed by various synthems ranging from eocene to pliocene, bounded by main erosional unconformities (dela pierre et al., 2003). this succession is deformed by an asymmetrical nw-verging anticline, with a sw-ne axis, that overthrusts onto the po plain foredeep along the padane thrust front, buried by the fluvial sediments of the plain (gelati & gnac 6 forno m.g. et al > > > > > > fig. 1 geological sketch map of the turin area and its surroundings. the wide proglacial outwash plain downstream of the rivoliavigliana end-moraine system (raes) is cut by the po r. incision where the po terraces are located. the municipal boundaries of turin are marked by the red line (modified from forno & gianotti, 2021). (b) digital model of terrain (dtm) of the same area. the study area is highlighted in yellow (5 m-dtm ice 2009-2011, courtesy of regione piemonte). 7 anthropogenic morphological modifications in turin 8 fig. 2 geological map of the po terraces in turin (modified from forno et al., 2022). forno m.g. et al southwards shift away from the hill watershed, suggesting a progressive uplift and southwards tilting of the southern slope (boano et al., 2004). this tilting eventually caused a natural river deviation of the po r. by an overflow phenomenon, to reach the current configuration in the turin plain during the lateglacial-holocene (forno et al., 2018). the new po r. deepened in the turin unit deposits, at the eastern edge of the raes proglacial plain, initially by shaping two high erosional terraces on the gravel of turin unit (molinette t1 and murazzi t2 terraces) and subsequently two lower depositional terraces essentially consisting of sand (vallere unit forming the t3 and meisino unit forming the t4 terraces) (forno & gianotti, 2021) (fig. 3). at the same time, another terraced sequence referred as vanchiglia, stura park and ortodossa church units was shaped due to the deepening in the proglacial plain of the tributary streams (sangone, dora riparia and stura di lanzo) (fig. 2). the 40 boreholes located in a ssw-nne elongated strip of eastern turin territory along the po r. allowed us to better understand the stratigraphic succession of the turin subsoil and highlighted the presence of a variously thick cover of anthropogenic deposits (forno et al., 2022), which is the specific object of this study about the anthropogenic modifications of the turin landscape. chronological references for the po river sediments in the po plain south of turin, essentially from 14c dating of the sediments outcropping in the moncalieri-la loggia quarries, form two distinct sets, a more ancient set ranging from >44,000 to 13,500 cal a bp and a more recent set ranging from 6800 to 59 cal a bp (tropeano & olive, 1989 with references; forno et al., 2018). the more ancient data refer to the previous po r. flowing south of turin hill, while the more recent set is related to the current direction of the po r. that has developed north of the hill. the lack of references between 13,500 and 6,800 cal a bp can help to define the age of the po r. deviation, in which the shaping of the erosional terraces t1 and t2 occurred (forno et al., 2018). in particular, nine radiocarbon ages obtained from some cores in the urban sector of turin (pesc 03, pesc 09bis, pesc 12 and val 74 cores), ranging from 855±23 to 173±23 a bp, supplied a historical age (1158 colini, 1982; biella et al., 1997; festa et al., 2009). the turin plain (fig. 1) consists of a glaciofluvial succession forming the proglacial plain of the rivoli-avigliana endmoraine system (raes), linked to the pleistocene glacial expansions of the dora riparia glacier at the susa valley outlet (ivy-ochs et al., 2018) and characterized by the occurrence of several fluvial terraces (forno & lucchesi, 2014; piana et al., 2017). most of the town of turin is founded on outwash sandy gravel and sand, with a cover of overbank silt (forno et al., 2018), identified as the turin unit, referred to the last glacial maximum (lgm) on morphoand pedostratigraphical criteria. this is also confirmed by the radiocarbon age of 37.7 ka cal bp at the bottom of the unit (at a depth of 18.3 m) acquired from the pes 17 borehole (fig. 2) (forno et al., 2022). this unit overlies a middle pleistocene glaciofluvial unit (bennale synthem; balestro et al., 2009), recognized both in outcrops along the sangone r. and in some geognostic cores in the turin subsoil thanks to the presence of a rubified palaeosol (forno et al., 2022). the whole glaciofluvial sequence lies on a subhorizontal erosional surface, buried at a depth between 10-60 m, carved into the marine transitional pliocene succession. only the eastern edge of the turin sector is constituted by sand and gravelly sand forming more recent terraces shaped by the po r. (forno & gianotti, 2021) (fig. 2). furthermore, the slopes of the turin hill keep traces of a long-lasting fluvial modelling somehow correlated with the setting of the plain below. in detail, its western and northwestern slopes show a sequence of deformed fluvial terraces related to the middle and late pleistocene, up to 480 m above the current po level linked to ancient path of the dora riparia and stura di lanzo rivers, and involved by a strong tectonic uplift (forno et al., 2002; forno & lucchesi, 2005). the overall data suggest the lack of the po r. as its current location at the western foot of the turin hill, until the late pleistocene (boano et al., 2004; barbero et al., 2007). moreover, the middle-upper pleistocene fluvial silty sediments and the wide abandoned meanders preserved in the southern slope of the turin hill are due to an ancient direction of the po r., which flowed south of turin hill until the last glacial maximum (lgm) (compagnoni & forno, 1992; forno & lucchesi, 2016). this ancient path of the po r. was involved in a gradual 9 anthropogenic morphological modifications in turin fig. 3 sketch showing the relationships between the stratigraphic units of the po terraces in turin (modified from forno & gianotti, 2021). -1803 ad) for the vallere unit forming the t3 terrace and allowed us to recognize a large buried stretch of the t3 terrace, hidden by thick landfill deposits (forno et al., 2022). 4. historical urban development of turin the roman colony of iulia augusta taurinorum was founded in 27 bc, located near the confluence of the dora riparia r. and the po r., but in a save-fromfloods location at 20-30 m above these riverbeds. however, remote origins of turin remain uncertain, since no archaeological discovery gives evidence of a preroman settlement (cresci marrone, 1997; see masci, 2012, for a review). the only pre-roman archaeological evidence found in the territory of turin are: (i) a few reworked fragments of ceramic vessels (7th-4th century bc) found in the archaeological excavations of palazzo madama (gambari, 2008) on the turin unit; (ii) ceramics dated to the second iron age in an alluvial layer in the subsoil of piazza della repubblica on the vanchiglia unit (peirani baricco & subbrizio, 2002); (iii) the remains of a small settlement of the taurini that has been dated between the 4th and the 3rd centuries bc at the bric san vito on the turin hill (pantò, 1994; gambari, 2008). turin was built in the typical quadrangular shape derived from the roman castrum (sides of 680 m and 750 m) with 5,000 inhabitants (diciotti & di nola, 2010). the monumental remains of the roman walls, the porta palatina and the theater, built in the 1st century ad (brecciaroli & gabucci, 2007) are the only evidence of augusta taurinorum. this city plan is still clearly visible by the orthogonal pattern formed by via garibaldi and via s. tommaso-via porta palatina which correspond to the decumaus maximus and the cardo maximum, respectively. 10 fig. 4 location of the reported anthropogenic modifications in turin (basemap from carta tecnica regionale bdtre 2023 at scale 1:50,000). forno m.g. et al co-spanish war 1635-59; see fig. 9a) and the siege of 1706 by the french army. until the end of the 17th century, turin was confined to the surface of the high glaciofluvial terrace, far enough away from its four rivers, except for some manufacturing facilities (such as several mills), the gardens of two ducal palaces (valentino and mirafiori) and, above all, the borgo po village, lying on the t1-t3 terraces in the right-hand bank of the po r. after the demolition of the 17th century bastions in the early 1800s, an initial expansion towards the po r. began but always remaining at a higher elevation on the t1-t2 terraces. turin, after becoming the first capital of the modern kingdom of italy in 1861, grew in population (250,000 inhabitants in 1870 ad) and experienced a rapid industrialization and an urban expansion northward on the high terrace of the dora riparia (vanchiglia district, on the vanchiglia unit, fig. 2) and subsequently also on part of the dora alluvial plain (vanchiglietta district on the parco stura unit, fig. 2). the ancient city was much more connected to the dora riparia r. than to the po r., thanks to the greater ease of water drawing damming the tributary riverbed only 5 km upstream to supply drinking fountains and the thermae, the sewer network, and the development of productive activities, especially mills. archaeological excavations have revealed a complex of warehouses close to the right bank north of porta palatina. land reclamations and bank defence works, made up of thousands of amphorae on the right bank of the river was discovered and document a first modification or containment of the dora riverbed (mercando, 2003). additionally, rests of warehouses extending over 2,000 m2, used between the 1st and 3nd centuries, have also been found on the po r. banks (gabucci & pejrani baricco, 2009). turin became the capital of the duchy of savoy in 1563 (20,000 inhabitants) and of the kingdom of sardinia in 1720 (90,000 inhabitants), mainly in baroque style. in this period, the major historical events were the double siege of turin in 1640 (during the conflict of the fran 11 fig. 5 (a) preserved foundation walls and relicts of staircases of the mirafiori castle along the high scarp shaped by the sangone r. in the turin terrace; (b) ancient course of the sangone r. far from the castle (carta topografica della caccia, 1762); (c) path of the sangone r. close below the mirafiori castle as a result of a cut of a meander reported in b (rcsmg, 1850b); (d) reconstruction of the various paths of the sangone r. over time: it formerly flowed relatively far from the castle (pre 1762), leaving space for a large park, subsequently (1850) it moved close the castle scarp and finally it was artificially moved a little away from the escarpment (topographic base: ctr bdtre 2022 at 1:10,000 scale) (see fig. 2 for the geological legend); p: peat. anthropogenic morphological modifications in turin the largest expansion on the proglacial high terrace (turin unit, fig. 2) took place between the two world wars (1918-1939) (430,000 inhabitants) when the periphery of the city expanded towards the south (crocetta, lingotto, millefonti, santa rita), the west (cenisia, cit turin, san donato) and the north (barriera di milano, borgo vittoria). urbanization (current 886,000 inhabitants) took place along the 500 m-wide narrow river strips of the po r., limited to the t1 and t2 terraces (molinette and murazzi units, fig. 2) and to the alluvial fans of the creeks originating from the turin hill (valsalice and sassi units, fig. 2). turin was partially reconstructed after the second world war, due to the aerial bombings creating a lot of rubble that was disposed in landfills. 5. anthropogenic modifications deduced by ancient topographic maps the ancient topographic maps of turin indicate that several modifications of the surface are essentially connected to the natural evolutions of the streams (see 5.2), but most modifications also involved anthropic interventions (see 5.1, 5.3, 5.4) (fig. 4). in the more complex cases, i.e. the over-elevation of natural terraces and the fillings of marshy depressions or creek incisions (see 5.5), the recognition of original natural landscapes on ancient maps was fundamental for understanding the context, geometries and distribution of the different landfill accumulations highlighted by the subsoil data. 5.1. mirafiori park meander the cartographic analysis and the field survey prove how the sangone riverbed experienced substantial changes near the mirafiori castle (1 in fig. 4). the original castle, which began to be built in 1585, has now disappeared, and only few foundation walls are preserved (fig. 5a). the most interesting and characterizing aspect of this castle, widely reported in historical documents, is the topographic setting on which the building and its park were located (battaglio, 2021). the ancient papers described the castle as located on a nice hill with a panoramic view of the sangone alluvial plain, rich in meadows and woods, and comfortably reached across a 12 fig. 6 (a) the natural sangone riverbed immediately downstream of the mirafiori castle does not show any ancient meander (rcsmg, 1850b); (b) and (c) the natural nichelino meander is reported by more recent topographic maps (igm, 1911; igm, 1950); (d) geological map with different paths of the nichelino meander in the time, also showing the current riverbed of the sangone r., bounded by bank defence (brown line) (topographic base: ctr bdtre 2022 at 1:10,000 scale of regione piemonte) (see fig. 2 for the legend). forno m.g. et al en, 1834) (fig. 5b). the sangone r. path in the ancient configuration was partly natural, its progressive widening being brought about by the evolution of the meander, partly anthropogenic, linked to the construction of garden steps (1587-1627) and fountains, that also implied attempts to locally divert the riverbed (baggio et al., 2003). subsequently, a natural meander cut created a straight riverbed, very close to the natural high terrace scarp on which the castle was built, as reported on the topographic maps of 1850 and 1854 (fig. 5c). on the contrary, the lowest terrace of the ortodossa church unit is associated with the current straight path of the sangone river, consisting of a low-sinuosity single channel (fig. 5d). river diversion is responsible for the separation between the mirafiori castle and the mirafiori park, which from that time were located on the left-hand and right-hand sides of the river respectively, and was probably linked to the big alluvial event of 12-15 september 1810 (baggio et al., 2003; giulietto & luino, 2006). the large meander is still shown in a map of 1834 probably out of date, given that no other major flood occurred until october 1857. long flat road (lupo, 1985). the geomorphological survey indicates that the mirafiori castle is built on the turin terrace (at 240 m a.s.l.), formed by fluvial gravel of the turin unit mostly supplied by the dora riparia basin, on the edge of the 15 m-high scarp that separates this terrace from the sangone incision (at 225 m a.s.l.). on the contrary, the mirafiori park is located on the low alluvial terraces underneath (at 233-230 m a.s.l.) shaped by the current sangone riverbed. large staircases, in small part preserved, connected the two terraces (fig. 5a). a 1020 m wide abandoned meander, with a depth of 1-3 m and a meander curvature radius of approximately 400 m is still preserved. locally, peaty layers outcrop within this landform. the abandoned meander is shaped in the terraced fluvial sequence ascribed to the vanchiglia unit (higher terrace) and to the stura park unit (lower terrace). this meander was buried by the building of several factories in the northwestern corner of the map and goes on the nichelino meander at the eastern edge. the sangone riverbed was initially far from the mirafiori castle, leaving space for a large park contiguous to the castle at the core of a large meander, as reported by ancient maps (carta topografica della caccia, 1762; de carloy, 1785; grossi, 1791; nicolosino & doy 13 fig. 7 small natural changes in the position of the confluence between po and sangone rivers over time, inferred comparing ancient maps (carta della caccia, 1762) (a) with more recent maps (rcsmg, 1850d) (b). as late as 1975 an aerial photo (volo rati, 1975) (c) displays an active meander near the confluence (blue arrow), as against a slightly more recent cover (volo comune di torino, 1979) (d) which has the new, straight confluence, though preserving the relict of the previous meander (blue arrow). anthropogenic morphological modifications in turin the recent construction of the public boschetto park at the site of the previous mirafiori park implied some other small morphological changes along the sangone r., as shown by comparison with old maps. these modifications involved a minor removal of the sangone r. from the natural scarp by means of the interposition of landfill deposits reinforced by embankments (fig. 5d). 5.2. nichelino meander the sangone riverbed, immediately downstream of the mirafiori castle (2 in fig. 4), does not show any meander in the maps before 1850 (fig. 6a). on the contrary, a new natural meander was abruptly formed in the 1880 inside the current nichelino inhabited area, and it is reported in the 1880, 1887, 1911 and 1919 maps until the 1950 (fig. 6b). river rectification was carried out artificially (giulietto & luino, 2006) between 1950 (igm map of 1950; fig. 6c) and 1968 (e.g., in the igm map of 1968 the riverbed has the same path as the current one). the construction of large factories on the right side of the sangone r. implied the recent construction of a bank defence and the stabilization of the riverbed (fig. 6d), which then switched from a variable natural path to an artificial fixed one. the geomorphological survey showed evidence of an abandoned meander, with a depth of 1-2 m and a curvature radius of approximately 300 m. this meander is shaped in the stura park unit and filled by the chiesa ortodossa unit. this landform is only partially preserved because it was essentially buried by the urbanization of the nichelino area. meander formation and abandon 14 >>>>> fig. 9 (a) ancient topographic map (siège de turin en 1640, 1643) showing numerous tributary incisions on the left side of the po r. between the dora riparia and the sangone tributaries: botanic garden (g); valentino (v); ergastolo (e); molinette (m); millefonti (f); (b) numerous tributary incisions of the po r. left side (v, e, m1, m2, m3, f1, f2, f3, f4, f5) and the sangone tributary incision named le basse (b) on the subsequent topographic map (rcsmg, 1850a); (c) now filled tributary incisions named le basse, presa di millefonti, millefonti, molinelle and reported by more recent maps (igm, 1911) (b, m2, f1, f3, f4, f5, v); (d) preserved valley, largely reshaped, on the valentino park; (e) detailed geological map reporting the filled tributary incisions (b, f, m, e, v, g) (from forno et al., 2022). fig. 8 ancient maps (stagnon, 1810; rcsmg, 1850c; igm, 1903) (a, b and c) reporting two significant meander loops in the dora riparia r. near the confluence with the po r.; more recent map (igm, 1911) (d) indicating the lack of the more western loop for the first enlargement of the turin monumental cemetery; current geological map drawn on the topographic map of 1991 (e), showing the lack of both meander loops to create a new building area (see fig. 2 for the legend). forno m.g. et al 15 anthropogenic morphological modifications in turin ment were also reported in recent morphological studies carried out essentially comparing aerial photos of different ages (giulietto & luino, 2006). 5.3. confluence between po and sangone rivers the natural evolution of the sangone r. at the confluence with the po r. is displayed in the old maps, which indicate small changes in the location of both the riverbeds and the confluence point (3 in fig. 4). the ancient path of the sangone r. with a meander loop near the confluence is shown on ancient topographic maps (carta topografica della caccia, 1760) (fig. 7a) and on more recent topographic maps (rcsmg, 1850b; igm, 1911) (fig. 7b) as well as on the geological map of 1969 (bortolami et al., 1969). however, the new sangone straight riverbed is shown only on recent maps (e.g., festa et al., 2009). historical documents, aerial photographs and ancient maps suggest that the confluence between po and sangone was artificially modified between 1976-78, as suggested by comparing previous aerial photograph (volo rati, 1975; fig. 7c), still showing the sangone meander loop, with the more recent aerial photograph (volo comune di torino, 1979; fig. 7d), indicating the current rectified path (arpa piemonte, 2018). the change in the sangone riverbed is to be related to the construction of the smat research center, which required a larger surface area for the installation and was not compatible with the presence of the meander. 5.4. dora riparia near the turin monumental cemetery the dora riparia r. experienced two significant anthropogenic deviations immediately upstream of its confluence with the po r. (4 in fig. 4). this course had a high-sinuosity meandering pattern, as shown in ancient documents, where two rather pronounced loops of meander were affected by a progressive enlargement (figs. 8a and 8b). these natural landforms are shown on ancient maps of 1805, 1810, 1850 and 1903 (sappa & compain, 1805; stagnon, 1810; rcsmg, 1850d; igm, 1903), on which a first small sector of the turin monumental cemetery is mapped (figs. 8b and 8c). the necessary expansion of this cemetery, consequent to the expansion of the town, required to cut out the larger western meander loop and to regularize and stabilize the new straight riverbed with bank defences (fig. 8d). this deviation was already indicated by more recent maps (igm, 1911; igm, 1923), where a wider turin cemetery is shown in place of the meander. 16 fig. 10 a preserved chimney of a brick-kiln at rivoli (nw of turin); ancient quarries near mirafiori (b) and at beinasco (c), characterized by a depression and by removal of the surficial level of clayey silt; (d) ancient brick-kilns reported in beinasco, turin and moncalieri on ancient topographic maps (igm, 1911; blue boxes). the meander of the low sangone r. near the confluence with the po r. is also shown. forno m.g. et al to 1 km long, were located on the left side of the po r. at the edge of the outwash plain (siège de turin en 1640, 1643; fig. 9a) and they have been progressively filled over time. moreover, the southernmost incision, over 2 km long and named le basse (b), represents a sangone tributary incision (igm, 1911, fig. 9c). most of the fluvial incisions were quickly filled, as evidenced by the less ancient maps (rcsmg, 1850a; fig. 9b), which no longer showed the depression of the botanic garden (g), and by the subsequent maps (igm, 1911; fig. 9c), where the main tributary incisions, named le basse (b), presa di millefonti (f4), millefonti (f1) and molinella (m2, now molinette) were still present while the ergastolo incision (and partially the valentino one) was missing. just one of these incisions is partly preserved in the valentino park, hosting the rock garden, near the turin exposition complex (v) (fig. 9d). another anthropogenic change in the dora riparia r. path, regarding the minor eastern meander loop, was carried out in the period 1930-1932 to create a new wide building area as reported in the current maps (forno & gianotti, 2021; fig. 8d). the geomorphological survey evidenced a preserved stretch of an abandoned dora riparia meander, with a depth of approximately 6 m, located along the boundary between the stura park and the chiesa ortodossa units and cut by the current rectified riverbed (fig. 8e). 5.5. filled tributary incisions the more ancient topographic maps of turin showed numerous fluvial incisions related to tributaries of the po r. directing approximately w-e (5 in fig. 4). these depressed landforms, some metres deep and up 17 anthropogenic morphological modifications in turin fig. 11 ancient map (la marchia, 1694-1703) showing the ancient morphology and the springs of the millefonti area (a); unità d’italia course built on landfill deposits that buried the po r. depositional t3 terrace (b); geological map showing palavela (pv) and palazzo del lavoro (bit) constructed on landfill above the t3 terrace (forno et al., 2022) (see fig. 2 for the legend) (c). the tributary incisions were eroded by small watercourses that flowed on the t1 terrace and also involved the surface of the proglacial fan formed by the turin unit through the regressive erosion. groundwater flowing out from these incisions fed numerous springs, now preserved only in the local toponyms, such as millefonti and molinette. these springs are likely connected to the stratigraphic contact between the turin unit (permeable gravels) and the underlying impermeable palaeosol preserved on the bennale unit, which some boreholes (pes 03, pes 05 in forno et al., 2022) met at a depth of 10-15 m. these springs fed a short watercourse, flowing towards ne near the fabbrica di tele metalliche, reported by the ancient topographic maps (la marchia, 16941703; rcsmg, 1850a; igm, 1911; figs. 11a and 11c) and corresponding to a now buried paleo-channel (fig. 11e). these tributary incisions created wide marshy areas that were subsequently reclaimed (città di torino, 1946). the intense land use and building construction, especially the erection of the molinette hospital complex in 1930-1935 and of unità d'italia course in 1935-1936, and the expansion of the nizza-millefonti district, implied the filling of the incisions. they are not visible in the current morphology as they are buried by thick anthropogenic fillings (fig. 9e). the filling of these incisions is also proved by some boreholes in which a very thick cover of anthropogenic sediments occurs (7 m in arpa 35; forno & gianotti, 2021). 6. anthropogenic modifications deduced by field survey some anthropogenic modifications were essentially recognized by the geological and geomorphological survey. particularly significant are wide sectors in which the morphology and the surficial geological succession are extensively anomalous when compared with the surrounding areas (see 6.1). elsewhere, an apparently natural morphology hides thick landfill bodies covering the original landscape, as proved by the study of geognostic cores (see 6.2). 6.1. ancient brick-kilns evidence of wide surficial excavations is diffusely preserved in the southern sector of turin as well as in rivalta, beinasco and moncalieri municipalities (7 in fig. 4). the morphology of these sectors, now characterized by slight depressions bordered by 1-2 m high subvertical scarps, suggests the anthropogenic lowering of the natural morphology compared to the surrounding sectors (fig. 10b). gravel of the turin unit forms the current topographic surface in these areas, while the complete succession should consist of fluvial sandy gravel overlain by a continuous thin cover of overbank sandy clayey silt (forno & gianotti, 2021). the current setting without silty cover suggests that the original cover was artificially removed (fig. 10c). these depressions are likely linked to the brick-kilns described by some historical documents (fig. 10a) shown on the ancient topographic map (igm, 1911) (fig. 10d). the ancient brick-kilns are located in beinasco (fornace bottone, fornace negri, fornace s. antonio, fornace barbera, fornace malcotti, fornace novaro and another fornace barbera), turin (fornace le basse) and moncalieri (fornace lavandè and fornace antica stazione) (fig. 10d). brick-kiln activities started in approximately 1860 and continued until 1960 to meet the needs of building expansion produced by the unification of italy. this 100year activity left a two-metre excavation on a total area of 667 ha (mongini & oddone, 2000). the change in brick manufacturing techniques and the opening of the new fiat factory led to the abandonment of kilns. fornace bottone and nuova fornace are the first and the last active brick factories, respectively, and the latter was located in the area of today's le fornaci shopping centre. 6.2. palavela, palazzo del lavoro and balbis bridge the long unità d’italia course (6 in fig. 4), an important communication route on the southern side of turin, is built on a narrow flat strip parallel to the po r. (fig. 11b). this strip essentially consists of thick bodies of anthropogenic sediments that mask the natural morphology of a po r. depositional t3 terrace (figs. 11c 18 fig. 12 the thick anthropogenic sediments reported from boreholes indicate in the sector of the palazzo del lavoro (bit) and unità d’italia course a buried depositional vallere terrace t3 (forno et al., 2022). forno m.g. et al between the two terraces. moreover, some large buildings were also constructed in the last century on southern turin, near the po r. these palaces, named palavela (pv) and palazzo del lavoro (also known as bit), were built on an anthropogenic surface consisting of very thick landfill sediments (fig. 12). a thick cover of anthropogenic sediments, which masks the different terrace scarps, is also located along the po r. banks. the wide distribution of these sediments, formed by angular brick fragments and rubble, is responsible for the diffuse lack of outcrops of the fluvial sediments forming the t3 and t4 terraces. 6.3. valentino park and cavour garden the valentino park is the most famous and oldest public park in turin, located along the po r. near the centre of the city (8 in fig. 4). this park was built in 1630, on project by carlo castellamonte, but was much improved between 1863 and 1864, becoming a public park. a better arrangement of avenues was implemented in this period, also creating a riding track and an artificial lake, which was used in winter as a skating ring and later dried up. the morandi building was recently and 12). the occurrence of a natural t3 terrace is also proved by the composition and dating of the fluvial sediments and by old maps (see fig. 6 in forno et al., 2022). in detail, a natural terraced surface located at 220-217 m can be reconstructed, buried by thick landfill deposits (10,5 m in pesc 03; 6 m in arpa17 at the palazzo del lavoro (bit); 8 m in arpa 21; 7 m in arpa 22 at the palavela (pv); 4.5 m in the pes 10; 8.5 m in pes 11; 9.5 m in pes 12 and in pes 09bis; 11 m in arpa 57; 9 m in arpa 58) (forno & gianotti, 2021; forno et al., 2022). this natural t3 terrace showed a peculiar morphology for the presence of a small alluvial fan at the outlet of the le basse incision and a short watercourse (igm, 1911) near the fabbrica di tele metalliche (igm, 1911; palaeochannel in fig. 11c), in which several springs flowed out (fig. 11a). this stream likely re-used an ancient direction of the sangone r. the unità d’italia course, getting closer to the centre of turin, where terrace t3 is lacking, must necessarily reach the t1 terrace at 232 m. therefore, it was necessary to build a ramp near the balbis bridge made of landfill material (9 m in core val61 and 7.5 m in core arpa 62) to overcome the high scarp originally existing 19 fig. 13 (a) ancient photography of the universal exposition of turin of 1911, showing the wide buildings quickly demolished in the following year; (b) hills chararcterizing the anthropogenic morphology of the northern sector of the valentino park; (c) the cavour garden built on the ruins of the ancient bastions; (d) geological map also comprising the valentino park (a and b), cavour garden (c) and royal gardens (d) (forno et al., 2022) (see fig. 2 for the legend). anthropogenic morphological modifications in turin constructed in the depression once occupied by this lake. the few important anthropogenic modifications of the valentino park landscape consist of the hillocks that currently characterize the northern sector of this park (b fig. 13d). these reliefs, high up to some metres (fig. 13b), are already visible on the maps since 1863 and more clearly on a 1935 map and are made of rubble essentially coming from the demolition of buildings. valentino park, for its vastness and panoramic view, was used in the time for the preparation of great national and international exhibitions (1829, 1838, 1844, 1850, 1858, 1871, 1884, 1998, 1902, 1911, 1928 and 1961) (bassignana, 2011; levra & roccia, 2011). the exhibition in 1884 led to the edification of the so-called medieval village, which today represents one of the main attractions of turin, built using various castles of piedmont and aosta valley as models. the geomorphological survey indicated that its construction was made essentially preserving the natural morphology of the po t2 and t3 terraces on which it is located. the exhibition of 1898 created the still preserved fountain of the twelve months, also built preserving the high scarp that separates the t1 terrace from the t3. the exhibition in 1911, even if led to the construction of numerous high and large buildings represented in 20 fig. 14 weir near the vittorio emanuele 1st bridge (a) and entrance of the michelotti canal (b) in the right bank of the po river; (c) ancient photograph (1884) of the michelotti canal, crossed by the eiffel iron bridge; (d) arch preserved in the sassi bridge on the po r. for the canal flow; (e) ancient topographic map (igm, 1911) that reports the michelotti canal on the right of the po r., from the weir (a) to the return to the stream (b). forno m.g. et al first dug and then filled. the michelotti canal had a long length (3436 m between the vittorio emanuele 1st bridge and il casotto near the confluence po-dora riparia), a remarkable width (7 m at the base and 12 m at the top), a substantial flow (up to 6.8 m3/sec) (fig. 14c) and a total drop in level of 130 cm. the preserved mobile floodgates kept the flow constant and prevented the accumulation of sediments. this canal was designed to replace the ancient floating mills with land mills (i.e., the molino delle catene), which represented an obstacle in the riverbed and a source of possible hydraulic risk (fig. 14e). the canal was totally filled with landfill deposits in 1935-36. its ancient route is also evidenced by the alignment of trees and buildings near the casale course, as well as an arch in the sassi bridge through which the canal passed (fig. 14d). 8. discussions and conclusions the progressive expansion of a city in an alluvial plain has a close relationship with the morphological evolution caused by both natural processes (erosional and/or depositional phenomena caused by watercourses) and by anthropogenic modifications of the topographic surface, that have occurred in recent years (excavations and/or fillings). for example, the construction of buildings in the southern sector of turin, as well as in rivalta, beinasco and moncalieri, had to adapt to the new morphology resulting from the shallow excavation related to the wide clay quarries (fig. 10). in the same way, the construction of buildings on terrace t3 in the northeastern sector of turin had to locally adapt to the excavation and filling of the michelotti canal (fig. 14). research on landscape modifications is particularly useful in an urban area, because a large amount of infrastructures is progressively constructed on its surface (buildings, bridges, overpasses) as well as in its shallow subsoil (subways, underpasses, foundations and underground floors of large buildings, sewers, power lines) and must take into account the morphology and its modifications. the same evolution of watercourses is influenced, in urban sites, not only by natural phenomena but also by widespread anthropic intervention, which comprises also major deviations of streams, in addition to the local building of embankments and bank defences. for example, the evolution of the dora riparia riverbed near the confluence with the po r. shows a complex relationship with the progressive building and expansion of the turin monumental cemetery, which eventually implied an anthropogenic deviation, creating a new rectified riverbed with abandonment of the previous wide meander (fig. 8). another case concerns the (anthropogenic) deviation of the sangone r. near the confluence with the po r. connected with a major building project (fig. 7). additionally, the bank defences along the current sangone r. into the quartier of nichelino prevent normal river migration and are aimed at stabilizing the natural cut of the nichelino meander (fig. 6). artificial deviations of streams are also well docuold photos (fig. 13a), created only a few morphological changes. the buildings and also a bridge were constructed with ephemeral materials (wood and plaster) and quickly demolished in the following year. finally, the last universal exposition of 1961 produced a gentle modification of the valley near the turin exposition village, crossed by artificial streams and decorated by many flowerbeds. this valley is not totally artificially excavated, but is likely located along an ancient natural tributary incision (see 5.5). other, elevating for some metres high hills, similar to those of valentino park, are also visible in cavour garden (fig. 13c) and royal garden (c and d in fig. 13d). 7. anthropogenic modifications deduced by historical reports finally, other anthropogenic modifications were essentially recognized by documents related to the turin history, written in favor of the knowledge and dissemination of the local events or finalized to the archaeological reconstruction of the territory. these local changes marked the landscape with evidence that was recognized through the geological and morphological survey (see 7.1). 7.1. michelotti canal preserved evidence of hydraulic modifications along the po r. indicates the building of a significant water canal for driving force in the po right bank, named michelotti canal after the engineer that designed it (9 in fig. 4). this evidence consists of a curved plant weir in the riverbed (fig. 14a) and a canal entrance in the right bank, with mobile floodgates, immediately downstream of the vittorio emanuele 1ts bridge (fig. 14b). the historical documents (lavazza, 2017) indicate that the michelotti canal was built in 1816, to supply water to the madonna del pilone mills, now deleted, but formerly located where the primary “altiero spinelli” school currently stands. this channel was built digging the surface of the t3 vallere terrace with a path parallel to the po r.: some stretch of this terrace was therefore 21 fig. 15 fluvial gravel containing brick clasts (red rounded cobble on the left) forming the chiesa ortodossa unit south of the mirafiori castle. anthropogenic morphological modifications in turin mented for other historical cities and particularly for the centre of rome, where the main deviation consists of the artificial acqua mariana canal, reported by ancient historical maps and photographs, that reused the previous river engraving of the nodicus r., left tributary of tiber r. (del monte, 2018). more generally, anthropogenic deviations of water courses may be misinterpreted as natural deviations in the absence of historical documents. a clear distinction between natural and anthropogenic modifications along a riverbed is not always easy. fluvial deposits of recent age not rarely incorporate fragments of anthropic artefacts, e.g. the fluvial body of the sangone r. forming the alluvial plain south of the mirafiori castle. this is composed of cross-bedded gravel and sand locally containing rounded brick clasts (fig. 15) connected to the reworking of ancient rubble. these natural fluvial deposits could easily be mistaken as anthropogenic landfill deposits when observed in few boreholes. on the contrary, the study of several boreholes (associated with outcrops of sediments) allow to reconstruct the detailed evolution of the natural hydrographic network, as the case of palatine hill in rome where a succession of paleo-valleys of different ages was reconstructed (mancini et al., 2018). also in alessandria a historical man-made hydrographic network, no longer recognizable, and the canalization of the tanaro r. were evidenced essentially by multitemporal analysis of historical maps (mandarino et al., 2020). the most important evidence of the landscape modifications (both natural and anthropogenic) on one hand consists of historical data, usually more direct and easy to read such as topographic maps and reports, aerial photos, and ancient photos; on the other hand, it includes subsoil data that are important but harder to obtain and must be interpreted in a complex way by integrating field observations on outcrops and landforms, geognostic cores and geochronological dating of sediments. the cross-use of various types of data is often important for geological reconstruction. the case of the natural changes followed by anthropogenic modifications of mirafiori park is particularly meaningful because it is indicated by various type of evidence (fig. 5). this case is reported by ancient topographic maps (where a wide sangone meander is shown far from the mirafiori castle), field surveys (through which an abandoned meander riverbed and various natural fluvial terraces and anthropogenic surfaces were recognized) and historical reports (in which the mirafiori castle and park are described contiguously and the castle is located a great distance from the sangone riverbed) (fig. 5). anyhow, the assessment of the extent of the changes is often difficult, because urban modifications are not always well documented and are not easy to find. it is particularly difficult to evaluate the real importance of landscape modifications owing to dubious reliability of some historical documents. ancient paintings related to the mirafiori castle, for example, show an unreal topographic surface that appears different from the current morphology preserving the ruined building (fig. 16). normally, you cannot trust even written observations by non-specialists, while you can well use the testimonials of qualified researchers, as in the case of the 22 fig. 16 ancient painting of the mirafiori castle that shows an imaginary very different castle from the real one (abret, 1670). forno m.g. et al the valentino park when it hosted large ephemeral buildings (soon dismantled) for the 1911 international exibition (fig. 13). in conclusion, the progressive building of turin was closely related to the natural evolution caused by geomorphic agents (above all erosional and/or depositional processes carried out by watercourses) but also by anthropogenic modifications of the topographic surface (excavations and/or fillings). understanding of this evolution and its final product is therefore of interest both to the scientists (the evolution) and to the geologists, engineers and architects dealing with the urban subsoil (the product). acknowledgements we are strongly indebted to the two anonymous reviewers and the associate editor alessandro fontana, for their careful review of our manuscript. we gratefully thank the staff of the lartu (laboratorio di analisi e rappresentazioni territoriali ed urbane) of the politecnico di torino for supporting us in the research and supply of cartographic materials. references abret g.b. (1670) veduta del castello di mirafiori. olio su tela, castello di racconigi. agnesi v. (2021) la geomorfologia di palermo. university press la sapienza, roma, pp. 171. arpa piemonte (2018) analisi e valutazione degli aspetti morfologici, torrente sangone, agenzia regionale per la protezione ambientale, attività 2017-2018. regione piemonte, 1-11. https://www.arpa.piemonte.it/approfondimenti/temi -ambiental i /geologia-e-dissesto/profluvial i / monitoraggio-morfologico-dei-corsi-dacqua/ sangone_04ss2n704pi.pdf baggio p., giardino m., mercalli l. (2003) val sangone: climi e forme del paesaggio: da due milioni di anni fa ad oggi, società metereologica subalpina, pp. 208. balestro g., spagnolo g., lucchesi s., fioraso g., forno m. g., cadoppi p., tallone s., piccardo g. b., polino r. (2009) foglio 155 “torino ovest” della carta geologica d'italia alla scala 1:50,000. apat, agenzia per la protezione dell'ambiente e per i servizi tecnici dipartimento difesa del suolo, roma. barbero d., boano p., colla m.t., forno m.g. (2007) pleistocene terraced fluvial succession, northern slope of the torino hill. quat. int. 2007, 171-172, 64-71. bassignana p.l. (2011) torino 1861-2011. storia di una città attraverso le esposizioni. edizione del capricorno, torino, pp. 261. battaglio m. (2021) il castello perduto nei prati di miraflores. torino storia, 60, 38-43. biella g.c., polino, r., de franco r., rossi p.m., clari p.a., corsi a., gelati r. (1997) the crustal structure of the western po plain: reconstruction from the integrated geological and seismic data. terra nova, 9, 28-31. bini m., brückner h., chelli a., pappalardo m., da prato nichelino meander, for which recent research evidenced its formation and abandonment along the time (fig. 6) (arpa piemonte, 2018; baggio et al., 2003). furthermore, there are cases in which the surface morphology is not congruent with the subsoil data, that can sometimes reveal large-scale anthropic modifications. in the turin area high terraces may simulate natural t2 terraces, while consisting of a very thick anthropogenic landfill lying above the fluvial sand forming a buried t3 terrace, as in the long stretch of unità d’italia course between the palazzo del lavoro and the balbis bridge (fig. 11). in this sector, the radiocarbon dating of the buried fluvial deposits was important to distinguish widely-extended landfill deposits (used to raise the low t3 terrace) from more localized landfill of yard excavations placed on the t2 high terrace (fig. 12). these fillings are made with the aim to over-elevating topographic surface terraces along the riverbeds (as is the t3 terrace along the po r.), comporting a recent progressive occupation of riverine areas, i.e. a very common practice as documented for rome, where large areas of the delta plain of the tiber r. were built for the expansion of the city and the construction of the fiumicino airport (del monte et al., 2016). the study of anthropogenic deposits is particularly detailed for rome, where the use of an interdisciplinary methodology allowed to estimate the thickness of this cover in the different sectors of the city (luberti et al., 2019). another major anthropic modification concerns large and thick landfills of fluvial incisions of left-hand tributaries of the po r. that cut the turin terrace at its eastern edge (fig. 9). these incisions can be identified in the ancient maps, but not in the new ones owing to total filling by landfill. in detail, the construction of the molinette hospital complex and the expansion of the nizza-millefonti district implied a filling of the tributary incisions, no longer visible for almost a century. the past existence of these small valleys is testified by brook displayed in engravings of ancient maps and confirmed by the core data. recent anthropogenic fillings of former valleys have also been recognized in the urbanized area of many other cities, such as in rome (such as the “fosso di santa croce” buried valley filled between 1676 and 1748 ad; vergari et al., 2020) and genua (the post 17th century filling of some stretches of the lagaccio and carbonara valleys; faccini et al., 2021). on the contrary, turin modifications do not comprise the demolition of whole hills, that characterized other cities such as rome (e.g., the progressive reduction and obliteration of the velia hill as documented by ancient photographs and maps; vergari et al., 2020). extensive demolition operations were not needed in turin because the city is built on an lgm alluvial plain without reliefs or high fluvial terraces. another morphology not congruent with stratigraphic data is observed for the anthropogenic excavations, as seen in the clay quarries associated with the brickkilns of the southern sector of turin, in which the overbank clayey silty cover of the turin unit is missing over large extents (fig. 10). on the other hand, major anthropogenic intervention are known to have taken place without significantly changing the natural topography. this occurred, e.g., in 23 anthropogenic morphological modifications in turin s., gervasini l. (2012) palaeogeographies of the magra valley coastal plain to constrain the location of the roman harbour of luna (nw italy). palaeogeography, palaeoclimatology, palaeoecology, 337-338, 37-51. bini m., rossi v., amorosi a., pappalardo m., sarti g., noti v., capitani m., fabiani f., gualandi m.l. (2015) palaeoenvironments and palaeotopography of a multilayered city during the etruscan and roman periods: early interaction of fluvial processses and urban growth at pisa (tuscany, italy). journal of archaeological science, 59, 197-210. boano p., forno m.g., lucchesi s. (2004) pleistocene deformation of the collina di torino inferred from the modelling of their fluvial succession. il quaternario, italian journal of quaternary sciences, 17 (2/1), 145-150. doi: 10.1016/j.quaint.2006.12.009 bortolami g.c., crema g.c., malaroda r., petrucci f., sacchi r., sturani c., venzo s. (1969) foglio 56 ‘torino’ della carta geologica d’italia alla scala 1:100,000, 2°ed., servizio geologico d’italia, rome, italy. bourgine b., dominique s., marache a., thierry p. (2009) tools and methods for constructing 3d geological models in the urban environment: the case of bordeaux. in: culshaw m.g., reeves h.j., jefferson i., spink t.w. (eds), engineering geology of tomorrow’s cities, geological society, london, engineering geology special publication 22, cd, paper n. 72. boyer l., bensoussan a., durand m., grice r.h., bérard j. (1985) geology of montreal, province of quebec, canada. bull. ass. eng. geol., 22, 333 -394. doi: 10.2113/gseegeosci.xxii.4.329 brandolini p., mandarino a., paliaga g., faccini f. (2020) anthropogenic landforms in an urbanized alluvial coastal plain (rapallo city, italy). journal of maps, 1-12. doi: 10.1080/17445647.2020.1793818 brandolini p., del monte m., faccini f., cattoor b., zwoliński z., smith m. (2021) geomorphological mapping in urban areas, journal of maps, 17 (4), 1 -5. doi: 10.1080/17445647.2021.1952671 brecciaroli taborelli l., gabucci a. (2007) le mura e il teatro di augusta taurinorum: sequenze stratigrafiche e dati cronologici, in forme e tempi dell’urbanizzazione nella cisalpina (ii secolo a.c. i secolo d.c.), atti delle giornate di studio (torino, 4-6 maggio 2006), a cura di brecciaroli taborelli l., firenze, 243-259. burnett a.d. (1988) geological and terrain mapping in hong kong. in: geology and urban development. atlas of urban geology, 1. united nations, new york, 85-97. carta topografica della caccia (1762-66) state archives of turin, section corte, secret topographic maps, torino 15 a vi rosso. città di torino (1946) progetto di risanamento delle zone paludose in prossimità delle vie testona e delle fontane., servizio tecnico ll. pp., divisione iva. ciugudean-toma v., stefanescu i. (2009) engineering geology of the bucharest city area, romania. in: culshaw m.g., reeves h.j., jefferson i., spink t.w. (eds). engineering geology of tomorrow’s cities. geological society, london, engineering geology special publication 22, cd paper n. 235. compagnoni r., forno m.g. (1992) significato geologico di depositi fluviali ghiaiosi pleistocenici medi nella collina di torino. il quaternario, italian journal of quaternary sciences, 5(1), 105-122. costa j.e., bilodeau s.w. (1982) geology of denver, colorado, united states of america. bull. assoc. eng. geol., 19, 261-314. cresci marrone g. (1997) la vigilia della romanizzazione, in sergi g. (a cura di), storia di torino. dalla preistoria al comune medievale, vol. 1, einaudi g., torino, 121-131. dall’aglio p.l., pellegrini l., ferrari k., marchetti g. (2011) correlazioni tra geografia fisica e urbanistica antica: il caso della pianura padana centrale. atti società toscana scienze naturali. memorie, serie a, 116, 85-94. de beer h., price s.j., ford j.r. (2012) 3d modelling of geological and anthropogenic deposits at the world heritage site of bryggen in bergen, norway. quaternary international, 251, 107-116. doi: 10.1016/j.quaint.2011.06.015 de carloy f. (1785) carta topografica dimostrativa dei contorni della città di torino (785-c.t.x-f.01). in: lupo g.m. (1989). cartografia di torino (15721954). stamperia artistica nazionale, pp. 181. dela pierre f., piana f., fioraso g., boano p., bicchi e., forno m.g., violanti d., clari p.a., polino r. (2003) note illustrative della carta geologica d’italia alla scala 1:50,000. foglio 157 “trino”. apat, agenzia per la protezione dell’ambiente e per i servizi tecnici-dipartimento difesa del suolo, rome, italy, pp. 147. del monte m. (2018) la geomorfologia di roma. university press la sapienza, pp. 218. del monte m., d’orefice m., luberti g.m., marini r., pica a., vergari f. (2016) geomorphological classification of urban landscapes: the case study of rome (italy). journal of maps 12(suppl. 1), 178189. doi: 10.1080/17445647.2016.1187977 diciotti f., di nola e. (eds.) (2010) guida archeologica di torino. gruppo archeologico torinese, l’artistica savigliano, vol. 1, 125 pp, vol. 2, pp. 195. do val m.a., lázaro a.a., stuermer m.m. (2009) the influence of geology on the urban development of são paulo city, brazil. in: culshaw mg, reeves hj, jefferson i, spink tw (eds). engineering geology of tomorrow’s cities. geological society, london, engineering geology special publication 22, cd paper n. 480. faccini f., giardino m., paliaga g. perotti l., brandolini p. (2020) urban geomorphology of genoa old city (italy). journal of maps, 17, 51-64. doi: 10.1080/17445647.2020.1777214 festa a., boano p., irace a., lucchesi s., forno m.g., dela pierre f., fioraso g., piana f. (2009) foglio 24 forno m.g. et al https://doi.org/10.1016/j.quaint.2006.12.009 https://www.museotorino.it/view/s/fb11cd00aa984245bd16c0ed71bd7c19 https://www.museotorino.it/view/s/fb11cd00aa984245bd16c0ed71bd7c19 https://www.museotorino.it/view/s/4faa4a4fd37441beb32c9ae811bec486 https://www.museotorino.it/view/s/4faa4a4fd37441beb32c9ae811bec486 https://www.museotorino.it/view/s/4faa4a4fd37441beb32c9ae811bec486 https://www.museotorino.it/view/s/4faa4a4fd37441beb32c9ae811bec486 https://www.ibs.it/libri-vintage/editori/stamperia-artistica-nazionale grossi g.l.a. (1791) carta corografica dimostrativa del territorio della città di torino. luoghi e parti confinanti (791-c.t.x.-f.01). in: lupo g.m. (1989). cartografia di torino (1572-1954). stamperia artistica nazionale, 181 pp. guerra v., guerra c., nesci o. (2020) geomorphology of the town of rimini and surrounding areas (emiliaromagna, italy). journal of maps. doi: 10. 1080/17445647.2020.1800527 hasan s., moberly r.l., caoile j.a. (1988) geology of greater kansas city, missouri and kansas, united states of america. bull. ass. en. geol., 25, 281341. igm (1903) tavoletta 1:25,000 torino, foglio 56 iii s.e. istituto geografico militare, firenze. igm (1911) tavoletta 1:25,000 torino, foglio 56, iii s.e. istituto geografico militare, firenze igm (1923) tavoletta 1:25,000 torino, foglio 56, iii s.e. istituto geografico militare, firenze. igm (1950) tavoletta 1:25,000 torino, foglio 56, iii s.e. istituto geografico militare. ivy-ochs s., lucchesi s., baggio p., fioraso g., gianotti f., monegato g., graf a., akcar n., christl m., carraro f., forno m.g., schluchter c. (2018) new geomorphological and chronological constraints for glacial deposits in the rivoli-avigliana end-moraine system and the lower susa valley (western alps, nw italy). j. quat. sci. 33, 550562. doi: 10.1002/jqs.3034 la marchia (1694-1703) carte de la montagne de turin avec l’etendue de la pleine dépuis le sangon jasqu’a la sture. state archives of turin, section corte, topographic maps a and b, torino, 14. lavazza m. (2017) scorreva il canale michelotti. torino storia, 2(18), 40-45. levra u., roccia r. (2011) le esposizioni torinesi (1805-1911). specchio del progresso e macchina del consenso. arte industria mestiere, 1(4), pp. 376. luberti g.m. (2018) computation of modern anthropogenic-deposit thicknesses in urban areas: a case study in rome. the anthropocene review, 5 (1), 2 -27. doi: 10.1177/2053019618757252 luberti g.m., vergari f., pica a., del monte m. (2019) estimation of the thickness of anthropogenic deposits in historical urban centres: an interdisciplinary methodology applied to rome (italy). the holocene, 29(1), 158-172. doi: 10.1177/0959683618804630 lupo g.m. (1985) i secoli di mirafiori. piemonte in bancarella ed., pp. 127. lupo g.m. (1989) cartografia di torino 1572-1954. stamperia artistica nazionale, torino, pp. 181. mancini m., marini m., moscatelli m., stigliano f., cavinato g.p., di salvo c., simionato m. (2018) stratigraphy of the palatine hill (rome, italy): a record of repeated middle pleistocene-holocene paleovalley incision and infill. alpine and mediterranean quaternary, 31(2), 171-194. doi: 10.26382/amq.2018.11 mandarino a., luino f., turconi l., faccini f. (2020) 156 “torino est” della carta geologica d'italia alla scala 1:50,000. apat, agenzia per la protezione dell'ambiente e per i servizi tecnicidipartimento difesa del suolo, roma. forno m.g., ben g., boano p., bocca p., boero v., compagnoni r. (2002) lembi di depositi fluviali provenienti dai bacini alpini nordoccidentali sulla collina di torino presso villa gualino (nw italy). il quaternario, il quaternario, italian journal of quaternary sciences, 15, 175-185. 29. forno m.g., lucchesi s. (2005) the fluvial pleistocenic terraced succession of w and nw slopes of the collina di torino. il quaternario, il quaternario, italian journal of quaternary sciences, 18, 123134. doi: 10.1080/17445647.2015.1027481 forno m.g., lucchesi s. (2014) la successione pliocenico-quaternaria su cui è edificata la città di torino e il suo significato per l’utilizzo del territorio. geol. dell’ambiente, 1, 3-10. forno m.g., lucchesi s. (2016) relicts of the pleistocene po plain on the western and southern slopes of the turin hill (nw italy). journal of maps, 12(2), 394-406. doi: 10.1080/17445647.2015.1027481 forno m.g., de luca d., bonasera m., bucci a., gianotti f., lasagna m., lucchesi s., pelizza s., piana f., taddia g. (2018) synthesis on the turin subsoil stratigraphy and hydrogeology (nw italy). alpine mediterranean quaternary, 31(2), 147-170. doi: 10.26382/amq.2018.10 forno m.g., gianotti f. (2021) the turin fluvial terraces as evidence of the new setting of the po river. journal of maps, 17(4), 75-85. doi: 10.1080/17445647.2020.1768447 forno m.g., gianotti f., storti u. (2022) geomorphology of the po fluvial terraces in turin deduced by new subsoil data (nw italy). water, 14(18), 2872. doi: 10.3390/w14182872 forster a. (1997) the engineering geology of the london area: 1:50,000 geological sheets 256, 257, 270, 271. technical report wn/97/27. british geological survey, keyworth. gabucci a., peirani baricco l.p. (2009) elementi di edilizia e urbanistica di augusta taurinorum. trasformazioni della forma urbana e topografia archeologica. in: annibaletto m., ghedini f. (eds), intra illa moenia domus ac penates (liv. 2,40, 7). il tessuto abitativo nelle città romane della cisalpina. atti delle giornate di studio, padova 10-11 aprile 2008, antenor quaderni 14, 229-245 gambari f.m. (ed.) (2008) taurini sul confine. il bric san vito di pecetto nell’età del ferro, celid, torino. gelati r., gnaccolini m. (1982) evoluzione tettonicosedimentaria della zona limite tra alpi ed appennino tra l’inizio dell’oligocene ed il miocene medio. mem. soc. geol. it., 24, 183-191. giulietto w., luino f. (2006) utilizzo di un’analisi multidisciplinare per la delimitazione delle aree potenzialmente inondabili: il caso del torrente sangone presso la confluenza con il fiume po (provincia di torino). giorn. geol. app., 4, 57-64. doi: 10.1474/gga.2006-04.0-07.0135 25 anthropogenic morphological modifications in turin https://www.ibs.it/libri-vintage/editori/stamperia-artistica-nazionale http://dx.doi.org/10.1080/17445647.2015.1027481 urban geomorphology of a historical city straddling the tanaro river (alessandria, nw italy). journal of maps, 17(3), 1-13. doi: 10.1080/17445647.2020.1746420 mandarino a., faccini f., terrone m., paliaga g. (2021) anthropogenic landforms and geo-hydrological hazards of the bisagno stream catchment (liguria, italy). journal of maps. doi: 10.1080/17445647.2020.1866704 martini i.p., sarti g., pallecchi p., costantini a. (2010) landscape influences on the development of the medieval-early renaissance city-states of pisa, florence, and siena, italy. in: p. martini, w. chesworth (eds.), landscape and societies. springer, netherlands, 203-223 masci g. (2012) la fondazione di augusta taurinorum: nuovi spunti di riflessione. historika. studi di storia greca e romana, 2, 63-78. doi: 10.13135/2039-4985/564 mercando l. (2003) il recupero del passato. in l. mercando (a cura di), archeologia a torino. dall'età preromana all'alto medioevo, u. allemandi, torino, 37-83. mongini g., oddone c. (2000) municipi e castellanie storia di beinasco dalle origini a oggi. allemandi publishing, pp. 323. mozzi p., piovan s., rossato s., cucato m., abbà t., fontana a. (2010) palaeohydrography and early settlements in padua (italy). il quaternario, il quaternario, italian journal of quaternary sciences, 23(2bis), 409-422. mozzi p., ferrarese f., zangrando d., gamba m., vigoni a., sainati c., fontana a., ninfo a., piovan s., rossato s., veronese f. (2017) the modeling of archaeological and geomorphic surfaces in a multistratified urban site in padua, italy. geoarchaeology, 33 (1), 67-84. doi: 10.1002/gea.21641 nicolosino m., doyen a. (1834) carta topografica della città e territorio di torino (834-c.t.x-f.01; 1834) in: lupo g.m. (1989). cartografia di torino (15721954). stamperia artistica nazionale, pp. 181. pantò g. (1994) pecetto, bric san vito. resti del castrum di monsferratus. restauro conservativo delle strutture. quaderni di archeologia del piemonte, 12, notiziario, 340-342. peirani baricco l., subbrizio m. (2002) indagini archeologiche nell’area del sottopasso veicolare di corso regina margherita a torino. quaderni di archeologia del piemonte, 19, notiziario, 41-49. pelfini m., brandolini f., d’archi s., pellegrini l., bollati i. (2020) papia civitas gloriosa: urban geomorphology for a thematic itinerary on geocultural heritage in pavia (central po plain, n italy). journal of maps. doi: 10.1080/17445647.2020.1736198 piana f., fioraso g., irace a., mosca p., d’atri a., barale, l., falletti, p., monegato, g., morelli, m., tallone, s., vigna, g.b. (2017) geology of piemonte region (nw italy, alps-apennines interference zone). journal of maps, 13(2), 395-405. doi: 10.1080/17445647. 2017.1316218 porta m., buosi c., trogu d., ibba a., de muro s. (2020) an integrated sea-land approach for analyzing forms, processes, deposits and the evolution of the urban coastal belt of cagliari. journal of maps. doi: 10.1080/17445647.2020.1719441 rcsmg (1850a) foglio 4 cavoretto scala 1:10,000, real corpo di stato maggiore generale, stamperia litografica m. doyen e compagnia. rcsmg (1850b) foglio 5e stupinigi scala 1:10,000, real corpo di stato maggiore generale, stamperia litografica m. doyen e compagnia. rcsmg (1850c) foglio 3 madonna del pilone scala 1:10,000, real corpo di stato maggiore generale, stamperia litografica m. doyen e compagnia. rcsmg (1850d) foglio 5 moncalieri scala 1:10,000, real corpo di stato maggiore generale, stamperia litografica m. doyen e compagnia. roccati a., mandarino a., perasso l., robbiano a., luino f., faccini f. (2020) large-scale geomorphology of the entella river floodplain (italy) for coastal urban areas management. journal of maps. doi: 10.1080/ 17445647.2020.1738281 salvador a. (1994) international stratigraphic guide. 2nd ed. geological society of america, pp. 214. sappa j.b., compain s. (1805) plan géométrique de la commune de turin alla scala al 50,000 (805-ca.t. f-f.01). in: lupo g.m. (1989). cartografia di torino (1572-1954). stamperia artistica nazionale, pp.181. sarti g., rossi v., amorosi a. (2012) influence of holocene stratigraphic architecture on ground surface settlements: a case study from the city of pisa (tuscany, italy). sedimentary geology, 281, 7587. doi: 10.1016/j.sedgeo.2012.08.008 shata a.a. (1988) geology of cairo, egypt. bull. assoc. eng. geol., 25,149-183. siège de turin en 1640 (1643) bibliothèque nationale de france, département estampes et photographie, fol-id-24. sparavigna a.c. (2020) sulla fondazione di torino come augusta taurinorum, ovvero sulla sua datazione. pp. 128. doi: 10.5281/zenodo.5137837 stagnon a.m. (1810) carta topografica di città torino e dei dintorni. fratelli reycend e c.a libraj. stefani m., zuppiroli m. (2010) the interaction of geological and anthropic processes shaping the urban growth of ferrara and the evolution of the surrounding plain. il quaternario, italian journal of quaternary sciences, 23 (2bis), 355-372. stefani m., minarelli l., pavanati a. (2020) cartografia geologica e storia deposizionale dei corpi sedimentari accumulati da po e reno nell’area di ferrara. bollettino di geofisica teorica ed applicata, 60 (2), 112-118. thierry p., prunier-leparmentier a.m., lembezat c., vanoudheusden e., vernoux j.f. (2009) 3d geological modelling at urban scale and mapping of ground movement susceptibility from gypsum dissolution: the paris example (france). engineering geology, 105 (1-2), 51-64. 26 forno m.g. et al https://doi.org/10.1080/17445647.2020.1746420 https://www.ibs.it/libri-vintage/editori/stamperia-artistica-nazionale https://doi:10.1080/17445647.%202017.1316218 https://www.ibs.it/libri-vintage/editori/stamperia-artistica-nazionale http://dx.doi.org/10.5281/zenodo.5137837 williams d.b. (2015) too high and too steep: reshaping seattle’s topography. university of washington press, pp. 253. jstor.org/stable/j.ctvcwnk3t ff10.1016/j.enggeo.2008.12.010ff. ffhal-00514427f tropeano d., olive p. (1989) vitesse de la sédimentation holocène dans la plaine occidentale du pô (italie). quaternaire, 26, 65-71. vergari f., luberti g.m., pica a, del monte m. (2020) geomorphology of the historic centre of the urbs (rome, italy), journal of maps. doi: 10.1080/17445647.2020.1761465 27 ms. received: june 17, 2023 revised: november 2, 2023 accepted: december 4, 2023 available online: december 22, 2023 anthropogenic morphological modifications in turin http://www.jstor.org/stable/j.ctvcwnk3t http://www.jstor.org/stable/j.ctvcwnk3t https://doi.org/10.1080/17445647.2020.1761465 28 283 che pur essendo accertata la presenza di tali condizioni nel pleistocene sup. in una fascia altimetrica che andava dal limite delle nevi perenni lino al pedeappennino, tuttavia i depositi periglaciali sono raramente conservati a causa sia dei fenomeni erosivi e di degrada­ zione superficiale in regime post-glaciale, dei fattori climatici , de! sollevamento tettonico recente e de! disboscamento intensivo opera­ to in epoca storica. i lembi residui di depositi e le evidenze morfologiche riferibili a processi periglaciali de! pleistocene sup. si riscontrano comunque, in fasce di quota tra i 700 m ed i 1000 m s.l.m. depositi di materiale prodotto da gelifrazione e messo in posto per geliflusso, si riscontrano ai margini di rilievi arenacei o car­ bonatici , in corrispondenza delle aree di affioramento dei complessi di base argillitici delle liguridi. panizza (1968) e panizza & mantovani (1974) hanno segnalato depositi periglaciali nell'area di pavullo de! frignano (appennino modenese), a quote comprese fra 650-700 m s.l.m. depositi simili sono stati riconosciuti da colombetti (1975) nell'area di zocca-castel d'aiano (appennino modenese) , a 700-800 m s.l.m. ii gsueg (1976) descrive depositi periglaciali nell 'area della pietra di bismantova (appennino reggiano). si tratta in particola­ re di lembi di un deposito di glacis da geliflusso, situato alla base delle scarpate della rupe di bismantova, a quote comprese ira 500-900 m s.l.m. depositi di glacis, nicchie di nivazione, riferibili ad un ambiente paleoclimatico periglaciale nel pleistocene superiore, sono stati inoltre descritti nell'area di febbio nell'appennino emiliano (gag, 1982) a quote comprese ira 900 e 1050 m s.l.m. sempre ii gag (1982) segnala a n de! m. la piella (appenino emiliano) un esempio di ghiacciaio di pietre (rock glaciel') , owero di un deposito a forma di lingua, che si sviluppa per una lunghezza di circa 300 m, costituito da blocchi arenacei marcatamente angolari. nell'area di febbio , sul versante s del m.prampa a quota 1500 m s.l.m. e stata riscontrata da bernini et alii (1978) una falda detritica stratificata (grezes litees o eboulis ordonnes) , potente oltre 20 m, formata da clasti angolari di gelifrazione con materiale limo­ so interstiziale. ii deposito e stato attribuito al secondo periodo pleniglaciale del pleistocene superiore. la falda detritica stratificata de! m.prampa rappresenta una delle poche documentazioni, nell'appenino emiliano, di tali depositi che costituiscono invece una delle caratteristiche tipiche de! paesaggio in zone montane nell'appenino umbro-marchigiano, dove sono stati accuratamente descritti da diversi autori (coltorti et al. , 1983; dramis, 1984; coltorti & dramis, 1987; 1988). nelle marche le !aide detritiche stratificate, spesse anche diverse decine di metri , sono state riscontrate a quote variabili ira i 200 m ed i 2000 m s.l.m., parti­ colarmente in corrispondenza di litotipi ad elevata gelivita, quali calcari e calcari marnosi. secondo dramis (1984b) , esse sono riferibili a due generazioni successive, datate in base alle relazioni con i terrazzi fluviali : la prima e attribuibile al pleistocene media, la seconda al pleistocene superiore (wurm) . aicerche in corso presso ii dipartimento di scienze della terra di firenze hanno evidenziato la presenza di !aide detritiche stratificate anche in diverse localita de! versante tirrenico dell'appennino, come in val di lima (fazzuoli et al., 1992), nell 'appenino tosco-romagnolo-marchigiano (m. fumaiolo; canuti , 1993) ed in toscana meridionale nella zona amiatina (m. cetona, m. civitella, m. labbro; canuti , 1993). altre caratteristiche morfologiche de! territorio montano dell 'appennino toscano, quali colate di terra o di detrito di vaste dimensioni, sostanzialmente inattive e difficilmente interpretabili nel quadro cimatico attuale, sembrano confermare la presenza di un regime climatico periglaciale nel pleistocene superiore. la back analysis di queste colate di terra, svolta con i metodi consueti della stabil ita dei versanti, ha evidenziato che i meccani­ smi di movimento richiedono valori di pressione interstiziale molto elevati (talvolta artesiani) che non trovano plausibile spiegazione nell 'attuale contesto idrogeologico di tali zone. un'altra tipologia di instabilita dei versanti che presenta notevoli problemi di interpreta­ zione sono le cosiddette deformazioni gravitative profonde che si osservano in alcune placche rocciose sovrastanti materiali argillosi. nella maggior parte dei casi registrati nell'appennino settentrionale, i principali fenomeni di questo tipo sono scarsamente attivi o sostanzialmente inattivi, salvo alcune porzioni , e sembrano essersi sviluppati in un diverso regime climatico. questa ha portato a porsi delle domande e a vedere anche se esistono delle relazioni ira i caratteri geomorfologici di questi fenomeni ed i movimenti di versante connessi a fenomeni periglaciali. una stretta relazione ira eventi franosi -in particolare quelli di grandi dimensionied ii clima e stata riscontrata da hutchinson (1991) e da zaruba & mencl (1982) . hutchison attribuisce al disgelo de! permafrost una notevole importanza per quanta riguarda la stabilita dei versanti: questo fenomeno infatti determina, come conseguenza, la presenza di ingenti quantita di acqua nel terreno e la generazione di eccessi di pressione nei pori , anche di tipo artesiano, in seguito ai processi di carico non drenato causati dal collasso della struttura del terrano, secondo un meccanismo noto come "consolidazione per disgelo" (morgestern & nixon). l'aumento delle pressioni neutre e ii softening (ii processo di rammollimento) che si instaurano nei materiali argillosi sovraconsolidati a seguito del disgelo, conducono ad una caduta della resistenza al taglio del terreno, favorendo quindi l'evoluzione di fenomeni di tipo gravitativo, anche di notevoli dimensioni, che non trovano giustificazione nel quadro morfoclimatico attuale. allara, noi vorremmo affrontare questo argomento, che per gli applicati si trova un po' al limite della loro preparazione; lo vor­ remmo affrontare con chi si occupa di clima e di morfologia e studia i processi periglaciali. aiteniamo che l'argomento sia di notevole interesse scientifico che presenti un aspetto, applicativo che e opportuno comprendere e la cui non valutazione ci fa trovare impre ­ parati di fronte a comportamenti , spesso coinvolgenti masse considerevoli di materiali , che possono porre vincoli rilevanti alla realiz­ zazione di grandi opere di ingegneria. per la bibliografia vedere: bartolini c. & carton a. , 1992 genni di geomorfologia. in: bortolotti v. (ed.} appennino tosco-emiliano. guide geologiche aegionali , soc. geol. it. , be-ma editrice, 86-90. geological history of the anagni basin including paleontological and archaeological findings, which represent the evolution of the territory through the quaternary. the museum aspires to become a key cultural reference for the region, rooted in a town already renowned for its historical importance. anagni, a major center for medieval studies (e.g., the 1303 “schiaffo di anagni” [literally, “the slap of anagni”], when king philip iv of france clashed with pope boniface viii, leading to the pope’s brief imprisonment by sciarra colonna, also offers a remarkable window into the history of earth and human evolution. its surrounding territory holds exceptional paleontological findings and evidence of early human presence, spanning the last two million years. the primary objective of the mae is twofold: to consolidate its status as a cultural pole and resource for the municipality of anagni, and to integrate its famous medieval heritage with that of its deeper past. a significant proportion of the findings exhibited at the mae comes from numerous excavations in the area surrounding anagni. these excavations have yielded a substantial number of finds attributable to fossil homo populations, all located within the sacco valley, which contains available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 38 (1), 2025, 31-43 https://doi.org/10.26382/amq.2025.02 1. introduction the museo archeologico ernico (mae) of anagni (frosinone) is a new and significant cultural institution dedicated to the preservation and promotion of the rich archaeological and paleontological heritage of the surrounding territory. the scientific and exhibition design project for the mae's ground and first floors begun in march 2022 and culminated in its inauguration on may 10, 2023. this goal was achieved through close collaboration between the ministry of culture, the superintendency of archaeology, fine arts and landscape (sabap, soprintendenza archeologia, belle arti e paesaggio) for the provinces of frosinone and latina and the municipality of anagni, through a scientific partnership with sapienza university of rome. the collaboration was coordinated by researchers, and professionals in relevant fields from the department of earth sciences of sapienza university (fig. 1). the exhibition was organized in eight thematic rooms maintaining the pre-existing layout of the first two floors of the museum building. the thematic journey of the mae focuses on the the museo archeologico ernico of anagni (frosinone, italy): a new paleontological and paleoanthropological exhibition in the “city of the popes” jacopo conti1,2,3, serena vona3, marco germani3, alessio iannucci4,3, dawid a. iurino5,3, beniamino mecozzi6,3, mattia yuri messina8,3, alfio moscarella3, marta pioggia3, flavia strani7,3, raffaele sardella2,3 1 polo museale, sapienza università di roma, roma, italy. 2 dipartimento scienze della terra, sapienza università di roma, roma, italy. 3 paleofactory laboratory, dipartimento scienze della terra, sapienza università di roma, roma, italy. 4 department geosciences, terrestrial palaeoclimatology, eberhard karls university of tübingen, tübingen, germany. 5 dipartimento scienze della terra ‘ardito desio’, università degli studi di milano, milano, italy. 6 dipartimento biologia ambientale, sapienza università di roma, roma, italy. 7 departamento ciencias de la tierra, iuca, universidad de zaragoza, zaragoza, spain. 8 dipartimento scienze chimiche e geologiche, università degli studi di cagliari, monserrato (ca), italy. corresponding author: jacopo conti <jacopo.conti@uniroma1.it> abstract: opened in may 2023, the museo archeologico ernico (mae) in anagni, italy, is a newly established institution dedicated to preserving and showcasing the archeological and paleontological heritage of the anagni basin (southern latium). this paper presents an overview of the museum's scientific and exhibition design, developed through a collaborative partnership between the ministry of culture, the superintendency for the provinces of frosinone and latina, and the municipality of anagni, under the scientific coordination of sapienza university. the mae highlights significant discoveries from key pleistocene sites in the sacco valley, including the early pleistocene fauna of coste san giacomo and the middle pleistocene hominin and faunal remains from fontana ranuccio. the exhibition, organized in eight thematic rooms, focuses on human evolution, geological and climatic dynamics, paleontological and archaeological research methods. beyond its role as an exhibition space, the mae aims to serve as a pivotal cultural and scientific institution, fostering local collaboration and implementing strategic initiatives to boost visitor engagement and promote the valorization of the rich archaeological and paleontological heritage of the sacco valley. with its modern infrastructure, the museum promotes accessibility, integration, and the use of innovative technologies, making it a significant resource for both academic research and public education. keywords: pleistocene, paleontological and archaeological heritage, science museum, anagni basin, human evolution. mailto:jacopo.conti@uniroma1.it fontana ranuccio and coste san giacomo two of italy's most important localities for the study of the quaternary (cassoli & segre naldini, 1984; segre & ascenzi, 1984; segre naldini et al., 2009; bellucci et al., 2012, 2014; angelucci et al., 2023). 2. the geological and paleoanthropological context of the sacco valley the valle latina (latin valley) is a tectonic depression located in southern latium, extending from rome to cassino along the course of the sacco river. it is bounded to the east by the lepini and volsci mountains, composed primarily of mesozoic carbonate successions, and to the west by the ernici mountains (cretaceous-miocene). during the apennine orogeny, these formations were subjected to compressive stress and thrusting, with significant phases of tectonic compression during the miocene and pliocene (carrara et al., 1995; sani et al., 2004; pereira et al., 2018) (fig. 2). during the pleistocene, the region experienced an extensional phase that led to the formation of several intramontane basins. the infilling of these depressions generated the quaternary continental successions of the area, predominantly composed of fluviolacustrine deposits such as gravels, sands, clays, and silts, as well as pyroclastic layers sourced from volcanic centers active in the central latin valley between approximately 700,000 and 250,000 years ago. the most prominent of these intramontane basins is the anagni basin, covering an area of roughly 20 km² (pereira et al., 2018). what grants this basin its scientific relevance is the paleontological record preserved within its continental stratigraphy a record that reconstructs the quaternary history of central italy through multiple phases. renowned sites of this territory are coste san giacomo, fontana ranuccio, colle marino and ceprano. 2.1. the site of coste san giacomo (csg) discovered in 1978 and dated approximately to 2.2 million years ago, the site of coste san giacomo is one of the most important italian and european localities containing vertebrate faunas from the middle villafranchian of the early pleistocene (palombo et al., 2003). the site's stratigraphy reveals an initial fluvial-torrential phase, followed by lacustrine deposits and finally fluvial and continental layers. these sedimentary conditions enabled the preservation of fossil remains, especially within sandy and clayey layers (bellucci et al., 2012, 2014; florindo et al., 2021). the site of coste san giacomo yielded a diverse vertebrate fauna, including especially large but also 32 conti j. et al. fig. 1 external view of the mae (museo archeologico ernico), anagni, latium. spanned from forests to open grasslands (cassoli & segre naldini, 1993; strani et al., 2018; bona & strani, 2021; conti et al., 2021; alberdi et al., 2024). human remains attributable to homo heidelbergensis, the presumed common ancestor of homo sapiens and homo neanderthalensis have also been recovered, alongside numerous flint tools, indicating prehistoric human activity at the site and four teeth (segre & ascenzi, 1984; rubini et al., 2014, zanolli et al., 2018; grimaldi et al., 2020; angelucci et al., 2023). fontana ranuccio is another reference locality for a european land mammal biochronological scheme, giving the name to one of the galerian faunal units around 400.000 years ago; (see iannucci & sardella, 2023, for discussion). 2.3. the ceprano cranium another site worth mentioning located near the anagni basin is ceprano, where a middle pleistocene human fossil was found by mr. italo biddittu in 1994, during road construction work. the specimen consists of fragments found in a layer of clay, hence the name “argil” (clay in italian) which constitutes a cranial vault (calvarium) representing an archaic human form characterized by a low, thick cranial dome and a strongly developed supraorbital torus (ascenzi et al., 1996, 2000; manzi et al., 2001; di vincenzo et al., 2017; buzi et al., 2021). overall, the fossil displays a mosaic of morphological features that appear transitional between homo erectus and homo heidelbergensis, suggesting it may represent an archaic form of the latter species. dated between 430,000 and 385,000 years ago, the ceprano cranium is one of the oldest hominin remains (even if partial) discovered in italy. its significance lies in the insights it provides into early human evolution on the continent, particularly regarding dispersal dynamics and diversification of prehistoric populations in italy and across europe (manzi, 2016; buzi et al., 2021). small mammals, and amphibians (bellucci et al., 2012, 2014, 2024; bona et al., 2015; strani et al., 2015; palombo et al., 2017; villa et al., 2021). for instance, several carnivorans are present at coste san giacomo, namely canis etruscus, pliocrocuta perrieri, martellictis ardea, ursus sp. and vulpes alopecoides. the site documents one of the earliest european occurrences of the hippo hippopotamus sp., the coexistence of the mastodon anancus arvernensis and the mammoth mammuthus meridionalis, and the largest european sample of the vole mimomys pliocaenicus (bona et al., 2015; bellucci et al., 2024; iannucci et al., 2023). for its importance, coste san giacomo has been taken as representative of a faunal unit, the last of the middle villafranchian recognized in the italian peninsula, playing a key role in the correlation of the gelasian continental paleontological sites of europe (gliozzi et al., 1997; bellucci et al., 2014; iannucci et al., 2023). 2.2. the site of fontana ranuccio fontana ranuccio represents a markedly different phase of the pleistocene. the site was discovered in 1976 during quarrying activities. excavations, primarily led by the istituto italiano di paleontologia umana (isipu), uncovered a pleistocene fauna and human remains initially dated to c. 450 ka, based on the 40k/39ar dating performed by biddittu et al. (1979) and subsequently redated at c. 400 ka with the 40ar/39ar technique (pereira et al., 2018). the sedimentary context is primarily volcanic, with stratigraphy composed of lapilli and scoria within a matrix of pedogenised colluvial sands. the fossiliferous layers also exhibit iron-rich diagenetic crusts indicative of post-depositional processes. notable faunal remains include carnivorans such as panthera sp. crocuta crocuta, canis mosbachensis, the presence of macaca sylvanus and the archaic form of cave bear ursus deningeri. the presence of stephanorhinus sp. and equus cf. e. mosbachensis, suggesting a range of habitats that 33 the museo archeologico ernico of anagni (frosinone, italy): a new ... fig. 2 reference map of the latina valley showing the locations of archaeological sites fontana ranuccio, cava pompi (c. pompi), campogrande (cg), isoletta, and lademagne. black triangles indicate the main volcanic centres. from pereira et al., 2018. 3. the museo archeologico ernico (mae): a hub for research and outreach, between past and present the exhibition is located on the ground and first floor of the museum building located in piazza guglielmo marconi, in the historic center of anagni. on the first floor, the exhibition route encompasses geo-paleontological, paleoanthropological, and archaeological thematic sections. for each of these sections the exhibited specimens were selected to explore the main themes of the exhibitions with a particular focus on the geologic evolution of the region and its ecosystems changes over the last 2 million years. to fully leverage the potential of the museum's spaces, the museological team conducted a comprehensive analysis of the existing structure. this involved not only an inventory of the available areas but also a detailed assessment of potential exhibition flow and critical emergency egress routes (fig. 3). concurrently with the museological planning, a virtual tour of the designated zones was developed. this digital model facilitated real-time visualization of the museological team's design choices, enabling more effective coordination with the museography team responsible for the physical implementation of the exhibition. the central idea of the exhibition is to place the anagni basin in a broader temporal context. this broadens the field of observation, going beyond the narrow focus on individual paleo-archaeological sites to embrace the overall evolution of the territory up to the present day. the understanding of the archaeological and paleontological discoveries in this area is enhanced by the recognition of the work of past scholars over the last century and the ongoing research of current specialists. to emphasize this, a dedicated room in the museum illustrates the evolution and modern methods used in paleontological and archaeological research (room 8). this approach not only honors the longstanding research efforts in the region but also imbues the finds with educational and engaging significance that extends beyond their purely scientific importance. 3.1. the museum structure considering the museum's structural organization across two levels, the visitor experience on the first floor unfolds through a series of thematically distinct rooms, each showcasing significant finds that highlight the archaeological, paleontological and geological richness of the region (fig. 4). the first room "the museum, anagni and its history”, serves as an introduction to the museum and the anagni city. a central display shows a partial cranium of bos primigenius with its impressive horn cores. this space acts as a crucial orientation point, clearly signposting the subsequent anthropological and geologicalpaleontological sections. the journey into human origins starts in the second room "introduction to human evolution", where key regional discoveries are presented in triangular showcases: a cast of the ceprano cranium, a fossilized hyena humerus and some lithic tools from colle marino, evidence of a human presence in the area around 650,000 years ago (angelucci et al., 2023). adjacent to this showcase, a cast of the so called "chimera", a virtual reconstruction of a hypothetical homo heidelbergensis, created by multiple specimens and digital modelling (profico et al., 2019) offers a tangible view into this ancient ancestor's morphology. explanatory panels contextualize these finds within the broader narrative of human evolution and the scientific methodologies employed in their study (fig. 5). room 3, "human evolution”, adopts a visually engaging approach, presenting human ancestry as a complex genealogical tree. at its center, a semi-circular ped 34 fig. 3 exhibit examples at mae. (a) skull of bos primigenius placed in the showcase donated by bancaanagni. (b,c) examples of triangular showcases displaying exhibits in the various rooms. conti j. et al. 35 fig. 4 museum's ground and first floors ayout, detailing exhibition and service areas: (01) the museum, anagni and its history; (02) introduction to human evolution; (03) human evolution; (04) geology and climate; (05) the coste san giacomo site; (06) the fontana ranuccio site part 1: environment and fauna; (07) the fontana ranuccio site part 2: humans and tools; (08) the middle pleistocene environment. the museo archeologico ernico of anagni (frosinone, italy): a new ... 36 estal displays a carefully curated selection of eight cranial casts representing the most known hominin species, illustrating the morphological changes over millions of years. a global map highlights key hominin discoveries worldwide, while a floor-level depiction of the evolutionary tree (fig. 6) spatially connects these ancestral forms. the deepness of the temporal context is established in room 4, "geology and climate”. here, two triangular showcases present stratigraphic and mineralogical samples that shed light on the geological forces that shaped the southern latium area and the principles of fossil dating. explanatory panels detail the region's dynamic geology, the science of stratigraphy, and the significant climatic fluctuations of the quaternary period, providing the essential backdrop for understanding the fossil records. the paleontological site of coste san giacomo (csg) is discussed in room 5, "the coste san giacomo site". showcases present key fossils from this 2.2 million year old early pleistocene site, including a tooth of homotherium, the saber tooth cat, along with a 3d print cast of the homotherium latidens cranium further enhances visitor inclusive experience. panels detail the site's discovery and multidisciplinary research, revealing a unique faunal assemblage including early occurrences fig. 5 a close-up view of the 'chimera', a virtual reconstruction of homo heidelbergensis, as exhibited in room 2. the background features explanatory panels and an artistic rendering of a possible female individual of this hominin specie. fig. 6 view of room 3 showcasing eight cranial casts representing key hominin species, arranged in front of a world map detailing significant global finds categorized by species. the foreground displays a stylized representation of the human evolutionary tree, illustrating the history of our ancestors. conti j. et al. of the genus hippopotamus and canis etruscus, alongside the coexistence of anancus arvernensis and mammuthus meridionalis emphasized by an animated video created by one of the authors (m.y.m.), which vividly reconstructs the csg environment and its fauna (fig. 7). room 6, "the fontana ranuccio site part 1: environment and fauna", introduces another crucial site of the valle del sacco basin, dating approximately 400,000 years ago. showcases display the diverse large mammal fauna species identified at the site, offering a glimpse into the middle pleistocene biodiversity. 3d prints of cave lion (panthera spelaea), hyena cranial casts and several 1:1 images of the animals “in vita” illustrated by one of the authors (f.s.), (fig. 8) provides detailed morphological insights of the species found. panels narrate the site's discovery, the research done during those years and the results obtained, such as the paleoenvironmental reconstruction, based on pollen and fossil analyses, which reveals a landscape of grasslands and woodlands inhabited by species such as palaeoloxodon antiquus, stephanorhinus hemitoechus, hippopotamus amphibius, and the early aurochs (bos primigenius), alongside predators like the cave lion and deninger's bear (ursus deningeri). the human presence at fontana ranuccio is the focus of room 7, "the fontana ranuccio site part 2: humans and tools". four significant human teeth discovered at the site digitalized by optical scanner and print in resin are shown in the room (fig. 9). another showcase presents a remarkable biface, made with elephant, alongside numerous retouched stone flakes, illustrating the sophisticated mode 2 acheulean technology employed. a pedestal highlights "small tools", refined flakes likely used for precision tasks. panels discuss the importance of human dental remains 37 fig. 8 reproduction of the extinct species represented in the museum. from left to right: clacton fallow deer, middle pleistocene red deer, praemegaceros, aurochs, middle pleistocene horse, stephanorhinus. shoulder height of red deer: around 1.20 m. the museo archeologico ernico of anagni (frosinone, italy): a new ... fig. 7 three frames of the videomapping showing the paleoenvironmental reconstruction of costa san giacomo and the detail of homotherium. cance. crafting this regional overview required a considerable amount of synthesis, as the team was tasked with selecting the essential information necessary to convey the area's central role in the development of paleoanthropological research. the challenge lay in condensing a complex scientific narrative into an intelligible and compelling format, without losing the richness and depth of the content. to achieve this, the panels integrate both thematic breadth and disciplinary depth. they provide foundational educational content on a range of topics, including paleoanthropology, stratigraphy, human evolution, virtual paleontology, the role of climate change as a key driver of evolutionary processes and the methods used in archaeological and paleontological excavation, offering visitors an understanding of the scientific processes behind the findings exhibited. this multifaceted approach was designed to engage a diverse audience one that includes general visitors who may not have a specialized academic background by equipping them with the conceptual tools necessary to appreciate the exhibits in their broader scientific context. alongside the selection of relevant content, an equally significant phase of the project was the editorial process. in close collaboration with the authors of the texts, the editorial team worked to streamline the language, eliminating redundant or overly technical passages that could hinder comprehension. a deliberately simple and linear syntax was adopted to enhance the readability of the texts and to ensure that even complex scientific ideas could be easily grasped. this careful editing phase was not merely a refinement of style, but a deliberate effort to align with the museum’s commitment to cultural accessibility and cultural democracy. the texts were thus restructured and revised to ensure that scientific knowledge could be transmitted clearly, accurately, and inclusively qualities essential to fostering informed public engagement. it was through continuous dialogue and mutual respect for both scientific rigor and communicative clarity that the final product emerged: a set of interpretive panels that are dense with information yet accessible to all (fig. 11). 4. mae: opening, developments, and future prospectives since its inauguration on 10 may 2023, the mae initially opened on weekends with free admission for several months, or upon specific requests from school groups or volunteers from the anagni proloco. in december 2023, the anagni municipal administration established crucial guidelines for the museum's initial phase, focusing exclusively on the first floor dedicated to the archeo-paleontological (resolution no. 39 of december 21, 2023). the administration gave key directives for an initial phase concentrated on developing the archeo-paleontological section, highlighting the importance of an intensive promotional strategy and cautious management of museum services. the introduction of essential services, such as web marketing strategies, data collection, guided tour management, and educational support, has optimized the museum's attractiveness and daily operation. february 2024 marked a turning point with the signing of a contract (lasting 10 months) with the company archeoares snc for the direct assignment of services specified in a previous resolution. despite the lack within the european middle pleistocene record and discuss the raw materials and production techniques of the lithic industry. finally, room 8, "the middle pleistocene environment", offers an immersive experience. a dedicated space introduces virtual paleontology, showcasing its applications through videos and 3d-printed animal crania and many large panels depict the megafauna of the preceding rooms (iurino et al., 2013, 2022; cherin et al., 2018). using existing trapdoors with walkable glass, some simulated fossil finds, excavation tools, and lithic casts are displayed from a unique "bottom-up" perspective. at the end of the exhibition path, a reconstructed excavation surface provides a tangible representation of archaeological practice, further detailed in an adjacent panel. a life-size, double-sided cutout of palaeoloxodon antiquus offers a striking encounter with an iconic species of this period (fig. 10). 3.2. the informative panels: objectives and contents in designing the museum’s informational panels, the curatorial team worked from the outset with the objective of promoting the museum as a cultural and scientific reference point for the territory it represents. the content of the panels has been developed to offer visitors not only a general introduction to the geopaleontological and archaeological characteristics of the area, but also to illuminate the broader scientific significance of the southern lazio region, whose contributions to the history of paleontology are of worldwide signifi 38 fig. 9 digitization of human dental remains from the fontana ranuccio site, held at the anthropological service of the s.b.a.l. (italian ministry of culture), and subsequent resin printing for public display. (a) virtual model acquired by optical scanner. (b) resin print of a fontana ranuccio tooth. on the left a resin model magnified in dimensions enlarged to enhance its morphological characteristics, on bottom two of the four printed and painted human teeth, on the right, a pla-printed human cranium is displayed, featuring highlighted teeth that represent the actual dental finds from the fontana ranuccio site. this presentation aims to improve comprehension of the specific teeth unearthed: an incisor, a canine, and two molars. conti j. et al. 39 fig. 10 the middle pleistocene environment exhibit: (a) floor display showing evidence of hominin marrow consumption. (b,c) final layout of the exhibition space. the museo archeologico ernico of anagni (frosinone, italy): a new ... access to multiple sites with a single purchase but also serves as a tool for enhancing the historical center of anagni, an area spanning approximately one kilometer that can be explored in about 20 minutes on foot. the creation of the "anagni pass" and ticketing strategies are steps towards the goal of a future concession of museum services to third parties, with the aim of creating a strong cultural network in the historical center of anagni, incentivizing tourism and the valorization of local heritage. two years after its opening, and following the decisions made by the municipality of anagni (determination no. 34 of january 10, 2025), artislendore italia srl has been tasked with managing its cultural services for seven months. this temporary choice serves to keep the museum open and functioning while the approval of internal regulations, the definition of services offered, the appointment of the scientific director, and the preparation for a long-term assignment are being completed. artislendore italia srl's responsibilities include online and onsite ticket sales, the organization of at least ten guided tours, activities for schools, and the coordination of all of this. of a full-time scientific director, the museum temporarily hired an activities coordinator, an employee of the company, with a part-time contract lasting ten months. the commitment to staff training and the museum's integration into the local cultural network, through agreements with cultural institutions and memoranda of understanding, has further strengthened its capacity to serve the community and visitors effectively. the mae management has adopted a proactive strategy to strengthen local cultural cooperation, promoting the signing of agreements and memoranda of understanding with other cultural bodies. in particular, the municipal administration has initiated a collaboration with o.p.e.s. to implement five universal civil service projects, an indispensable and useful resource for the museum's ticket office and reception activities. in march 2024, the "anagni pass" was conceived, established, and promoted, a single ticket providing access to both the mae and the nearby palazzo bonifacio viii. the introduction of this pass represents a strategic step towards integrating the mae into anagni's cultural and tourism fabric, fostering a synergy between local cultural institutions. the anagni pass not only facilitates 40 fig. 11 exhibit corner of the section concerning virtual paleontology (room 8). a) set up with digitized skulls in hands-on mode, video playback, and forex display panel summarizing some of the techniques used in modern paleontology and archaeology. b) example of display panel with qr-code for english version of the text. conti j. et al. 2762-2778. doi: 10.13133/2280-6148/18064 angelucci d., armellini j., biddittu i., bruni l., florindo f., marra f., nomade s., parenti f., pereira a., santaniello f., spagnolo v., grimaldi s. (2023) fontana ranuccio (excavations 2019-2022) and colle marino (excavations 2020-2021): middle pleistocene chronostratigraphic evidence of the earliest inhabitants in the anagni basin. journal of mediterranean earth sciences, 15, 51-63. doi: 10.13133/2280-6148/18064 ascenzi a., biddittu i., cassoli p.f., segre a.g., segre naldini e. (1996) a calvarium of late homo erectus from ceprano, italy. journal of human evolution, 31, 409-423. doi: 10.1006/jhev.1996.0069 ascenzi a., mallegni f., manzi g., segre a.g., segre naldini e. (2000) a re-appraisal of ceprano calvaria affinities with homo erectus, after the new reconstruction. journal of human evolution, 39, 443-450. doi: 10.1006/jhev.2000.0425 bellucci l., mazzini i., scardia g., bruni l., parenti f., segre a.g., segre naldini e., sardella r. (2012) the site of coste san giacomo (early pleistocene, central italy): palaeoenvironmental analysis and biochronological overview. quaternary international, 267, 30-39. doi: 10.1016/j.quaint.2011.04.006 bellucci l., bona f., corrado p., magri d., mazzini i., parenti f., scardia g., sardella r. (2014) evidence of late gelasian dispersal of african fauna at coste san giacomo (anagni basin, central italy): early pleistocene environments and the background of early human occupation in europe. quaternary science reviews, 96, 72-85. doi: 10.1016/j.quascirev.2013.10.011 bellucci l., bona f., conti j., mecozzi b., strani f., sardella r. (2024) the early pleistocene carnivoran of coste san giacomo (anagni, central italy): biochronological implications. quaternary, 7 (4), 57. doi: 10.3390/quat7040057 biddittu i., cassoli p.f., radicati di bronzolo f., segre a.g., segre naldini e., villa i. (1979) anagni a kar dated lower and middle-pleistocene site, central italy: preliminary report. quaternaria, 21, 5371. bona f., bellucci l., sardella r. (2015) the gelasian (late villanyan-mn17) diversified micromammal assemblage with mimomys pliocaenicus from coste san giacomo (anagni basin, central italy), taxonomy and comparison with selected european sites. hystrix, 26, 141-151. doi: 10.4404/hystrix-26.2-11441 bona f., strani f. (2021) new data on the middle pleistocene small mammal fauna from the homo bearing site of fontana ranuccio (anagni basin, central italy). alpine and mediterranean quaternary, 31(1), 135-139. doi: 10.26382/amq.2021.01 buzi c., di vincenzo f., profico a., manzi g. (2021) the pre-modern human fossil record in italy from the middle to the late pleistocene: an updated reappraisal. alpine and mediterranean quaternary, 34(1), 17-32. 5. conclusions the mae has significant potential as an important scientific and cultural resource. its modern and wellequipped facilities, which include areas for visitor reception, education and research, combined with the effective cooperation between the city management, cultural organization and universities, place it at the forefront among institutions dedicated to the cultural growth of the local area. this collaborative framework enables the museum to function as a nucleus of cultural, educational, and research activities, establishing it as a key reference point for culture and tourism in the region. the prospect of transforming the mae into a center of cultural and scientific excellence is a concrete and achievable ambition. the success of this transformation will depend on the implementation of modern management strategies that promote sustainability and the museum's integration into the broader cultural circuit. this, combined with the uniqueness of the exhibited finds, the focus on accessibility, and the use of innovative display and conservation technologies, will be crucial for its future impact. acknowledgements the authors wish to express sincere gratitude to the municipality of anagni, with acknowledgement to the mayor of anagni daniele natalia, for their belief and keen interest in achieving a project of long standing, and for financially supporting the work. special acknowledgement is extended to the ministry of culture, the superintendency of archaeology, fine arts and landscape for the provinces of frosinone and latina (francesco di mario) and latium (daniela quadrino). special thanks to chiara delpino, real “dea ex machina” of the project. the authors acknowledge mauro rubini (anthropological service of the s.b.a.l. italian ministry of culture) for granting access to the premises and the homo fossils from fontana ranuccio, thereby enabling the digitization of the dental remains. the authors acknowledge the polo museale sapienza for supplying essential software and instrumentations for the graphic contents and the reviewers who contributed to improving our paper. a kindfull thanks to marta stabile, for the illustrations of homo heidelbergensis exhibited in room 2. a special note of thanks is due to banc anag ni for their fundamental financial support. funding: raffaele sardella acknowledges the financial support of anagni municipality in cooperation with earth sciences department of sapienza. alessio iannucci is supported by the humboldt research fellowship provided by the alexander von humboldt foundation. flavia strani is supported by the marie skłodowska -curie actions programme (msca postdoctoral fellowship; project no. 101102131) funded by the european commission. references alberdi m.t., palombo m.r., strani f., bellucci l. (2024) the large horse from fontana ranuccio (anagni basin, central italy). historical biology, 36(12), 41 the museo archeologico ernico of anagni (frosinone, italy): a new ... iannucci a., sardella r. (2023) what does the “elephant-equus” event mean today? reflections on mammal dispersal events around the pliocenepleistocene boundary and the flexible ambiguity of biochronology. quaternary, 6(1), 16. doi: 10.3390/quat6010016 iurino d.a., danti m., della sala s.w., sardella r. (2013) modern techniques for ancient bones: vertebrate palaeontology and medical ct analysis = tecniche moderne per ossa antiche: paleontologia dei vertebrati e analisi tomografiche mediche. bollettino della societa paleontologica italiana, 52 (3), 145-155. iurino d.a., mecozzi b., iannucci a., moscarella a., strani f., bona f., gaeta m., sardella, r. (2022) a middle pleistocene wolf from central italy provides insights on the first occurrence of canis lupus in europe. scientific reports, 12(1), 2882. doi: 10.1038/s41598-022-06812-5 manzi g., mallegni f., ascenzi a. (2001) a cranium for the earliest europeans: phylogenetic position of the hominid from ceprano, italy. proceedings of the national academy of sciences usa, 98, 10011-10016. doi: 10.1073/pnas.15125999 manzi g. (2016) humans of the middle pleistocene: the controversial calvarium from ceprano (italy) and its significance for the origin and variability of homo heidelbergensis. quaternary international, 411, 254-261. doi: 10.1016/j.quaint.2015.12.047 palombo m.r., azanza b., alberdi m.t. (2003) italian mammal biochronology from latest miocene to middle pleistocene: a multivariate approach. geologica romana, 36, 335-368. palombo m.r., alberdi m.t., bellucci l., sardella r. (2017) an intriguing middle-sized horse from coste san giacomo (anagni basin, central italy). quaternary research, 87(2), 347-362. doi: 10.1017/qua.2017.6 pereira a., nomade s., moncel m.h., voinchet p., bahain j.j., biddittu i., falguères c., giaccio b., manzi g., parenti f., scardia g., scao v., sottili g., vietti a. (2018) integrated geochronology of acheulian sites from the southern latium (central italy): insights on human-environment interaction and the technological innovations during the mis 11-mis 10 period. quaternary science reviews, 187, 112-129. doi: 10.1016/j.quascirev.2018.03.021 profico a., bellucci l., buzi c., di vincenzo f., micarelli i., strani f., tafuri m. a., manzi g. (2019) virtual anthropology and its application in cultural heritage studies. studies in conservation, 64(6), 323336. doi: 10.1080/00393630.2018.1507705 rubini m., cerroni v., festa g., sardella r., zaio p.a. (2014) revision of hominin fossil teeth from fontana ranuccio (middle pleistocene, anagni, frosinone, italy). journal of human evolution, 77, 204216. doi: 10.1016/j.jhevol.2014.09.002 sani f., del ventisette c., montanari d., coli m., nafissi p., piazzini a. (2004) tectonic evolution of the internal sector of the central apennines, italy. marine and petroleum geology, 21, 1235-1254. doi: 10.26382/amq.2021.03 carrara c., frezzotti m., giraudi c. (1995) stratigrafia plio-quaternaria. in: carrara c. (ed.), lazio meridionale, sintesi delle ricerche geologiche multidisciplinari. enea, pp. 62-85. cassoli p.f., segre naldini e. (1984) nuovo contributo alla conoscenza delle faune villafranchiane e del pleistocene medio del bacino di anagni (frosinone). in: atti della xxiv riunione scientifica dell’istituto italiano di preistoria e protostoria, firenze, 115-118. cassoli f., segre naldini e. (1993) le faune. in: dives anagnia. archeologia della valle del sacco (ed. by gatti s.). l’erma di bretschneider, 30-38. cherin m., iurino d. a., zanatta m., fernandez v., paciaroni a., petrillo c., rettori r., sardella r. (2018) synchrotron radiation reveals the identity of the large felid from monte argentario (early pleistocene, italy). scientific reports, 8(1), 8338. doi: 10.1038/s41598-018-26698-6 conti j., bellucci l., iurino d.a., strani f., sardella r. (2021) review of ursus material from fontana ranuccio (middle pleistocene, central italy). new insights on the first occurrence of the brown bear in italy. alpine and mediterranean quaternary, 34 (1), 55-68. doi: 10.26382/amq.2021.14 di vincenzo f., profico a., bernardini f., cerroni v., dreossi d., schlager s., zaio p., benazzi s., biddittu i., rubini m., tuniz c., manzi g. (2017) digital reconstruction of the ceprano calvarium (italy), and implications for its interpretation. scientific reports, 7, 13974. doi: 10.1038/s41598-017-14437-2 florindo f., marra f., angelucci d. e., biddittu i., bruni l., florindo f., gaeta m., guillow h., jicha b., macrì p., morigi c., nomade s., parenti f., pereira a., grimaldi s. (2021) environmental evolution, faunal and human occupation since 2 ma in the anagni basin, central italy. scientific reports, 11(1), 7056. doi: 10.1038/s41598-021-85446-5 gliozzi e., abbazzi l., argenti p., azzaroli a., caloi l., capasso barbato l., di stefano g., esu d., ficcarelli g., girotti o., kotsakis t., masini f., mazza p., mezzabotta c., palombo m.r., petronio c., rook l., sala b., sardella r., zanalda e., torre d. (1997) biochronology of selected mammals, molluscs and ostracods from the middle pliocene to the late pleistocene in italy. the state of the art. rivista italiana di paleontologia e stratigrafia, 103, 369-388. doi: 10.1038/s41598-017-14437-2 grimaldi s., santaniello f., angelucci d.e., bruni l., parenti f. (2020) a techno-functional interpretation of the lithic assemblage from fontana ranuccio (anagni, central italy): an insight into a mis 11 human behaviour. journal of paleolithic archaeology, 3, 944-966. doi: 10.1007/s41982-020-00064-3 iannucci a., mecozzi b., sardella r. (2023) beware of the “wolf event” remarks on large mammal dispersals in europe and the late villafranchian faunal turnover. alpine and mediterranean quaternary, 36 (1), 75-90. doi: 10.26382/amq.2023.03 42 conti j. et al. villa a., minnelli e., bona f., bellucci l., sardella r., delfino m. (2021) the amphibians and reptiles from the early pleistocene of coste san giacomo (anagni basin, italy). historical biology, 33(11), 3075-3083. doi: 10.1080/08912963.2020.1849177 zanolli c., martinón-torres m., bernardini f., boschian g., coppa a., dreossi d., mancini l., de pinillos m.m., martín-francés l., de castr j.m.b., tozzi c., tuniz c., macchiarelli r. (2018) the middle pleistocene (mis 12) human dental remains from fontana ranuccio (latium) and visogliano (friulivenezia giulia), italy. a comparative high resolution endostructural assessment. plos one, 13(10), e0189773. doi: 10.1371/journal.pone.0189773 doi: 10.1016/j.marpetgeo.2004.09.004 segre a.g., ascenzi a. (1984) fontana ranuccio: italy’s earliest middle pleistocene hominid site. current anthropology, 25, 230-233. segre naldini e., muttoni g., parenti f., scardia g., segre a.g. (2009) nouvelles recherches dans le bassin plio-pléistocene d’anagni (latium méridional, italie). l’anthropologie, 113, 66-77. doi: 10.1016/j.anthro.2009.01.013 strani f., demiguel d., sardella r., bellucci l. (2015) paleoenvironments and climatic changes in the italian peninsula during the early pleistocene: evidence from dental wear patterns of the ungulate community of coste san giacomo. quaternary science reviews, 121, 28-35. doi: 10.1016/j.quascirev.2015.05.008 strani f., demiguel d., bona f., sardella r., biddittu i., bruni l., de castro a., guadagnoli f., bellucci l. (2018) ungulate dietary adaptations and palaeoecology of the middle pleistocene site of fontana ranuccio (anagni, central italy). palaeogeography, palaeoclimatology, palaeoecology, 496, 238247. doi: 10.1016/j.palaeo.2018.01.041 43 the museo archeologico ernico of anagni (frosinone, italy): a new ... ms. received: may 19, 2025 revised: june 25, 2025 accepted: june 27, 2025 available online: july 12, 2025 44 imp.carrara& calcareous tufa deposits of the aniene valley between vallepietra and mandela-vicovaro (latium, central italy) claudio carrara1, marili branca1, emanuela pisegna cerone2, vladimiro verrubbi3 & mario voltaggio1 1 cnr-igag, roma; m.branca@igag.cnr.it; claudio_carrara@fastwebnet; m.voltaggio@igag.cnr.it; 2 dip.to scienze della terra, università roma 1, emanuela.pisegnacerone@uniroma1.it; 3 enea c.r. casaccia, verrubbi@casaccia.enea.it abstract: carrara et al. – the calcareous tufa deposits of the aniene valley between vallepietra and mandela-vicovaro (latium, central italy). (it issn 0394-3356, 2006). calcareous tufa deposits occurring in the aniene and simbrivio valleys (latium, central italy) between vallepietra and mandelavicovaro areas have been studied by means of morpho-geological mapping, mineralogical and facies analysis, malacofauna investigation, geo-archeological research and u/th dating. the deposits of subiaco and mandela-vicovaro have been studied in detail, because their formation has modified not only the geomorphic features of the two areas, but has strongly controlled and directed the human activity. a 15 m thick calcareous tufa body occurring in a bore drilled near marano equo, intercalated in a paleoaniene alluvial deposits, has also been studied. after having examined the geological and structural pattern of the valley, controlled by apenninic (nw-se) and antiapenninic (ne-sw) faults and by a complex hydrological system, that makes it one of the richest valleys in spring-waters of latium (most of roman aqueducts came from the aniene valley), the deposits of the different sectors are described. calcareous tufa deposits, occurring in the simbrivio valley, connected to several cool springs issuing from the right, steep slope are described. the tufa deposits, prograding vertically and towards the valley bottom, interdigitate and often form highly vegetated terraces, on the front of which still active waterfalls, covered by moss and algae already partially calcified, occur. in the aniene valley, upstream of subiaco very interesting examples of still active tufa deposits, forming fan-shaped bodies, prograding towards the river bed, occur. they are made mainly of phytomicrohermal and stromatolitic laminites, rich in leaf moulds, covered by a thick mat of algae, mosses, liverworts and other hygrophytes. small barrage tufa deposits can also be observed. in the subiaco area a tufa deposit, covering an area of about 1 km2, 70-80 m thick, occurs; it represents a barrage deposit, formed in the gorge at the outlet of the subiaco basin, probably built up in correspondence to a morphological step of tectonic origin. its basal portion is mainly made of palustrine, thinly laminated facies, rich in leaf moulds and vegetal frustules, grading upward to massive or grossly stratified, phytomicrohermal framework, containing well-developed large pools, filled with sandy-silty phytoclastic sediments of fluvio-lacustrine environment. the outer part of the deposit is partially covered by vertical hanging festoons and drapes of moss cascade lithofacies. the deposit has been terraced in three orders of terraces by the river, at present flowing in a narrow gorge in the miocene substratum. the ist order terrace surface is covered by a thick, pedogenized soil colluvium, rich in volcanic minerals, while the terraces of the iind and iiird orders are covered by reddish-brown or brown soils, poor or devoid of volcanic minerals. in the mandela-vicovaro area a continuous calcareous tufa terrace extends along the aniene gorge for about 3 km, up to 60-70 m thick. it formed as a barrage deposit near vicovaro, where the emplacement of middle pleistocene volcanics, superimposed by younger, coarse alluvial sediments has produced a discontinuity in the river bed. as in the subiaco deposit, the lower portion of the mandela-vicovaro one is composed of thinly stratified, laminitic and microhermal lithofacies, rich in leaf molds and vegetal frustules, of palustrine environment. they grade upward to massive phytomicrohermal litofacies, associated with large sandy-silty pools, rich in malacofauna. the surface of the terrace is covered by brown, calcareous soil. the terrace has been cut deeply as far as the miocene substratum by the aniene river and licenza stream, its main right tributary. the sections of the terrace along the river are partially covered by waterfall moss lithofacies, forming vertical hanging drapes. the study of malacofauna contained in pool filling sands and silts referred the sediments to shallow freshwater, well vegetated environment, under temperate climate. several marano equo, subiaco and mandela-vicovaro samples have been dated by means of u/th method which allowed the reconstruction of the chronostratigraphic evolution of the three calcareous bodies, referring the first to late pleistocene, the second to upper pleistocene-early holocene and the third to late glacial-middle holocene. finally, on the basis of direct and bibliographic researches, the presence of roman dams built up in the subiaco area, forming upstream lacustrine basins, at present no longer existent, are discussed. riassunto: carrara et al. i travertini della valle dell’aniene tra vallepietra e mandela-vicovaro (lazio, italia centrale). (it issn 03943356, 2006). nel presente lavoro sono stati studiati i depositi di travertino presenti nella valle dell’aniene e del simbrivio, tra vallepietra e vicovaro, alcuni dei quali ancora in via di formazione. con particolare dettaglio sono stati studiati i vasti depositi di subiaco e di mandelavicovaro, che con la loro formazione hanno naturalmente modificato la struttura morfologica delle due aree, controllandone anche l’attività antropica. e’ stato studiato anche un corpo travertinoso di circa 15 m di spessore attraversato da un sondaggio effettuato presso marano equo, compreso in sedimenti alluvionali del paleoaniene e legato a sorgenti allora attive nell’area. dopo un esame geologico-strutturale della valle, profondamente controllata nel suo andamento da faglie appenniniche ed antiappenniniche e dalle condizioni idrogeologiche, che ne fanno una della valli del lazio più ricche di sorgenti, connesse con circuiti carsici molto sviluppati, si descrivono i lineamenti geo-morfologici dei depositi di travertino dei vari settori considerati. nel settore della valle del simbrivio si osservano modesti corpi interdigitati, connessi con una serie di sorgenti fredde emergenti sul ripido versante di destra della valle. detti corpi progradano verso il fiume, lungo il quale formano dei terrazzi di accumulo molto vegetati, in parte ancora attivi, con formazione di facies di cascata con muschi e alghe. nel settore della valle dell’aniene a monte di subiaco, si osservano begli esempi di corpi travertinosi di sbarramento fluviale e di corpi conoidiformi progradanti dal versante verso il fondovalle, ancora in via di deposizione, costituiti principalmente da facies fito-microermali e stromatolitiche, su ricca vegetazione di batteri, alghe, muschi, epatiche e altre igrofite. nel settore di subiaco è presente un grande deposito di travertino, ricoprente una superficie di circa 1 kmq, dello spessore di 70-80 m, creatosi per sbarramento della forra del fiume allo sbocco nel bacino di subiaco, sbarramento impostatosi probabilmente in corrispondenza di un gradino morfologico di controllo tettonico. la porzione basale è caratterizzata da facies di ambiente palustre, mentre la porzione medio-alta è costituita principalmente da facies fito-microermali massive o grossolanamente stratificate con sviluppo di vasche riempite da facies sabbioso-limose fitoclastiche. la scarpata del deposito è parzialmente coperta da grandi festoni e drappeggi verticali di facies fitoermali su muschio. il deposito, costituito da tre terrazzi deposizionali, è stato il quaternario italian journal of quaternary sciences 19(1), 2006 19-44 20 c. carrara et al. 1. introduction the calcareous tufa deposits1 occurring in the simbrivio and aniene valleys between vallepietra and mandela-vicovaro area have not yet been studied in detail. in the present work the mentioned deposits have been examined by means of detailed geo-morphological, sedimentological and facies analysis; mineralogical and petrographical composition, malacological content and u/th dating have also been determined. the research allowed not only the definition of their main geological features, but also their paleoenvironmental and paleoclimatic significance and evolution. the study has been carried out within the quaternary and paleoclimate research program of cnr-igag. 2. geological and morphological regional setting (c. carrara, v. verrubbi) the studied stretch of the aniene valley (fig. 1) has been deeply cut in geological formations attributed to different palaeogeographic units. east of the study area lithologies related to carbonate platform facies, from upper triassic to upper cretaceous in age, are widespread in the simbruini mountains. west of the aniene valley mainly transition and basinal facies occur. between these two palaeogeographic-structural units, upper-middle miocene siliciclastic deposits outcrop (damiani, 1992). the studied chain sector began to be involved with neogenic-quaternary geodynamic evolution from messinian times and underwent a polyphase tectonics resulting in imbricate ne vergency thrusts (bally et al., 1986), followed by nw-se extentional tectonics (salvini & storti, 1992; cavinato et al., 1992). during the lower pliocene last compressive tectonic phase, important e vergency thrusts occurred. sabina units, already structured in apenninic trend by preceding compressive phases, have been pushed toward east to pile up on the carbonate complex of latium-abruzzi platform. the tectonic line, along which the thrust of the basin units on the platform ones occurs, is known as olevano-antrodoco line. the later extensional tectonics that caused the dislocation of the thrust pile, dividing it into more or less extended, often tilted blocks and giving rise to horst and graben structures, is still active and is responsible for the seismicity observed in the upper aniene basin. the extensional tectonics has also determined the thinning of the crust along the tyrrhenian coast, favouring the upwell ing, from middle pleistocene, of the magma that has generated the alban hill district, immediately west of the studied area, and other volcanic centres within the apennine chain. after the complete emersion that took place in the upper miocene, the area underwent strong subaerial land shaping, mainly caused by the erosion due to meteoric water activity. it acted differently on calcareous and dolomitic sediments and on turbidites, depending on the degree of chemical and physical weathering of rocks, on their geometric setting, as well as on the microclimate of the exposed area and the climatic variations undergone. in carbonate sediments, outcropping generally in the highest parts, valleys show v cross profiles, more or less open according to their evolution stage. furthermore, they are often asymmetric because of different structural attitude. in the turbidite rocks the modelling gave rise to more open valleys with less steep slopes than the preceding ones. the cross sections have a higher degree of symmetry and generally the slopes are more regular. in some parts of the studied area a strong fluviodenudation process has been active. it has mainly affected dolomitic lithologies in the fiumata and vallepietra localities, where dolomites have been reduced to loose rocks with little aggregation of crystals, due to strong tectonic activity and secondary crystallization (damiani & pannuzi, 1981). infact, the slopes, cut into the dolomites, appear strongly incised and show several small valleys separated by short and sharp crests. in other carbonate inciso dal fiume, che attualmente scorre in una stretta forra con pareti di travertino, sul fondo della quale affiora il substrato miocenico. il terrazzo del i ordine è coperto da un colluvio di suolo fortemente evoluto, ricco di frammenti di rocce e minerali vulcanici; mentre sui terrazzi del ii e iii ordine si sviluppano un suolo rosso-bruno e bruno rispettivamente, poco sviluppati, privi o quasi di materiale vulcanico. nel settore di mandela-vicovaro, lungo la forra, si estende per circa 3 km un terrazzo di accumulo di travertino, con uno spessore che raggiunge 60-70 m, formatosi per sbarramento dell’aniene in corrispondenza di una discontinuità nel letto del fiume, causata dalla presenza di vulcaniti medio-pleistoceniche, sormontate da depositi alluvionali più recenti. come quello di subiaco, il corpo del terrazzo è costituito alla base da facie laminitiche e fito-microermali, sottilmente stratificate, ricche di foglie e frustoli vegetali, di ambiente palustre molto vegetato, passanti verso l’alto a facies massive microermali con sviluppo di ampie vasche a sedimentazione sabbioso-limosa, più o meno fitoclastica, ricca di malacofauna, di ambiente fluvio-lacustre. sulla superficie del terrazzo si sviluppa un suolo bruno, calcareo, mediamente sviluppato. anche qui il terrazzo è stato inciso fino al substrato miocenico dall’aniene e da alcuni tributari di destra. la scarpata del terrazzo lungo la valle è localmente coperta da spesse cortine verticali di travertino in facies fitoermale su muschio. lo studio della malacofauna contenuta nei limi di mandela ha permesso di riferirli a un ambiente temperato di acque basse, pozze d’acqua, piccoli laghi, ricchi di vegetazione. le numerose datazioni col metodo u/th di campioni di travertino dei depositi di marano equo, subiaco e mandela-vicovaro hanno permesso di ricostruire l’evoluzione dei depositi studiati, che cadono il primo nel pleistocene superiore, il secondo nel pleistocene superiore-olocene inferiore, il terzo nel tardo glaciale-olocene medio. infine, sulla base di ricerche dirette e bibliografiche, viene discussa la presenza di dighe di epoca romana, che sbarravano l’aniene presso subiaco, formando vasti laghi a monte. keywords: calcareous tufas, facies analysis, malacofauna, u/th dating, pleistocene, holocene, simbrivio-aniene, latium, italy. parole chiave: travertini, malacofauna, analisi di facies, datazioni u/th, pleistocene, olocene, simbrivio-aniene, lazio, italia. 1 “calcareous tufa” is a term widely used in the most recent international literature, as reported by capezzuoli & gandin, 2004, to define continental ”calcium carbonate deposits formed under cool water regime”. lithotypes too, examples of strong linear erosion can be observed, as in the orographic right of some stretches of the aniene valley between jenne and subiaco. the accumulation deposits resulting from fluviodenudation occur mainly as recent valley floor deposits, forming flat areas along the river; talus and landslide bodies sensu lato caused by strong erosion processes are also present (as for example south of santuario della trinità and under monastero di san benedetto). karstic modelling too is widespread on carbonate rocks. dolinas, poljes, sinkholes etc. among epigeal phenomena, caves among hypogean ones are well known. during the quaternary the considered area has been subjected to deposition of continental successions, particularly extended in the subiaco basin. herein, between cappuccini locality and agosta, on the right side of the aniene river, and near madonna del rapello, on the left side, deposits of stratified, horizontal, heterometric conglomerates, several tens of metres thick, composed of generally well reworked, grossly sorted and imbricated, mainly limestone pebbles, occur. they correspond to the “antiche alluvioni terrazzate” of the old authors (de angelis d’ossat, 1897; viola, 1903; beneo, 1934 and 1943). within the described deposits, intercalations of lacustrine episodes, composed of fine grained sediments, showing in places calcareous tufa characteristics, are described 21calcareous tufa deposits ... (damiani et al., 1998). they have been interpreted as deposited in the interchannel zones of the described alluvials, even if the authors do not esclude that they may represent a fandelta in a large lacustrine basin. in these deposits lignite levels as well as vertebrate remains (elephas antiquus falk.; rinoceros merkii kaup and jag.; bos taurus primigenii bos.; cervus euriceros aldr.) have been found that refer them to the pleistocene (ponzi, 1862, 1878; de angelis d’ossat, 1897,1924; damiani et al., 1998). similar deposits, in places showing clear breccia characteristics, related to ancient alluvial fans, and talus deposits are widespread in the vallepietra area. in the tract of valley between subiaco and vicovaro, small, in situ exsposures of intrapenninic middle pleistocene volcanics, widespread in the adjacent map sheets, represented by leucititic pyroclastic and lithoid flows, occur. weathered and often anthropically derived volcanoclastic ashes are also widespread (ponzi, 1852; damiani et al., 1998). it is important to note that strongly evolved, thick, soil colluvia, rich in small volcanic rock fragments and minerals, can be observed. they occur not only in the depressions and on the stable zones of siliciclastic and carbonate substratum, but also on the surfaces of the described terraced alluvials, as well as on the surface of the subiaco ist order calcareous tufa terrace (see 5.3). moreover, along the aniene river, downstream fig. 1 localization of the tufa deposits in the study area: 1. fonte acqua delle donne; 2. ponte del tartaro; 3. case reali; 4. brutto colatore; 5. comunacque; 6. acqua dei cardellini; 7. subiaco; 8. mandela-vicovaro. localizzazione dei depositi di travertino nell’area studiata: 1. fonte acqua delle donne; 2. ponte del tartaro; 3. case reali; 4. brutto colatore; 5. comunacque; 6. acqua dei cardellini; 7. subiaco; 8. mandela-vicovaro. 22 subiaco, local, lacustrine episodes and terraced deposits, referred to holocene, are present. 3. hydrogeological lineaments (c.carrara, v. verrubbi) the studied area (fig. 1) belongs to the iind order basin of the aniene river, tributary of the tiber river and is part of the mt. simbruini-ernici karstic hydrostructure, whose geometry follows the boundary marked by the upper miocene terrigenous sediments that surround the carbonate ridge (percopo, 1992). the river, that upstream subiaco and in the mandela-vicovaro area, shows the morphology of a very incised and narrow gorge, rises in granara valley at an elevation of 1619 m. from here as far as ponte delle tartare, where it receives the fosso campo, the river flows in ne-sw direction; at ponte delle tartare it changes direction and flows as far as cineto romano in se-nw direction; from here to vicovaro it takes again the former direction. these changes of direction are the result of the regional tectonic structure of the considered area; the nw-se trend is reported to be the more ancient, while that from ne to sw seems to be due to more recent tectonic structures (damiani & pannuzi, 1981; damiani, 1990a e 1990b). the tributaries of the aniene river generally pour into the river at right angle. not far upstream ponte comunacque the aniene river receives, on hydrographic right, the simbrivio stream that drains the vallepietra gorge and is fed by several cool springs issuing at an elevation of about 1000 m. other cool springs occur particularly upstream subiaco; among the most important ones: the inferniglio, pertuso, sorgenti di jenne, ponte del tartaro, acqua dei cardellini and comunacque can be mentioned. the abundance of spring waters of the aniene valley was well known by the romans; among the aqueducts bringing water to rome, at least four (anio vetus, anio novus, acqua marcia e claudia) came from the aniene valley (carosi, 1956). the waters of the mentioned springs are generally characterized by a carbonate-calcic, locally magnesic, composition, being connected mainly to calcareous and/or calcareous-dolomitic rocks. the ca/mg ratio allows the discrimination of the waters circulating in calcareous environment (higher values), from those belonging to dolomitic one (lower values) (brondi, 1995-96). almost in all the mentioned springs, either in their inner, karstic course or along the outer flow, more or less developed concretionary deposits, speleothems, calcareous pool infilling muds or other calcareous tufa deposits still depositing (simbrivio valley, ponte del tartaro, see 5.1) or prograding fan-shaped bodies (sorgente dell’acqua dei cardellini, see 5.2), occur. from subiaco to mandela-vicovaro area, along the aniene valley, small calcareous tufa bodies, related to cold springs, characterized by carbonate-calcic, magnesic, locally ferrugineous or sulphureous composition (ventriglia, 1990), occur. in the mandela-vicovaro area, on the contrary, between the aniene river on the southern side and the licenza stream on the northern side, an extended calcareous tufa deposit, described in detail in chap. 8, occurs. the formation of this deposit is related to several cool, mainly carbonate-calcic, magnesic springs (ventriglia,1990), linked to the hydrological circuits of the simbruini and lucretili mounts, draining partly towards the aniene river (boni, bono & capelli, 1988a e b). on the basis of geochemical and isotopic data of quaternary fossil and present travertines and the relative spring waters in the region north of rome, minissale et al. (2002) show that there are important differences in their composition between the springs and deposits placed west and east of the tiber valley. the western deposits show typical thermogenic (high temperature) characteristics, while the eastern ones (including the springs and travertine deposits described in the present work) show meteogenic (low temperature) characteristics. “the travertine-precipitating waters east of the tiber valley have shallower flow paths than those to the west”, therefore they are cooler and “have co2 isotopic signatures, indicating a significant biogenic contribution acquired from soils in the recharge area and limited deeply derived co2”. 4. previous authors (c. carrara) geological information about travertine deposits of the considered stretch of aniene valley are scarse and short. among the first the geological observations on travertine deposits of the roman country can be mentioned that of pellati (1882), where the author cites travertine quarries of the subiaco area, some of which give high quality material, while others produce only light and vacuolar travertine. an interesting, geological-geographic work on the upper aniene valley is that published by de angelis d’ossat (1897). in this work, besides the orographic, hydrographic and geological description of the area, the deposits of “lower post-pliocene age (sic)”, comprising the terraced conglomerates of subiaco containing mammal rests and several more or less consolidated volcanic in situ products are described in detail. the deposits of “upper and recent post-pliocene (sic)” comprise mainly travertine sediments and weathered loose volcanic materials mixed with colluvial detritus. the author asserts that travertine deposits are widespread in the subiaco area, where they seem to form “three different surfaces (sic)” likely terraced by the river that deeply cut them, and in mandela-s. cosimato area. they are rich in moulds of leaves, present flora and snails. moreover, the author states that in the deposit of the sambuci stream he found a frontal portion of a deer skull cut by man, while near jenne and mandela a big harts-horn and a fragment of an ox shoulder, both clearly recent, have been found respectively. the loose volcanic materials mixed with colluvial detritus, composed mainly of augite, black mica, feldspar and leucite grains, occur in several parts of the valley not only on ancient formations, but also on the most recent ones, such as the subiaco conglomerates, the travertines and the recent alluvial deposits of the aniene river. viola (1903) breif ly describes the ancient c. carrara et al. 23 quaternary of the aniene valley, which comprises several deposits of terraced conglomerates, occurring near subiaco and in other parts of the valley, and travertine deposits of subiaco and mandela-vicovaro areas. the subiaco travertine deposit, according to the author, forms a terraced body of a thickness not less than 100 m, spread on a surface of about 1 km2. this body, as well as that of mandela-vicovaro area, has been cut by the river that reached the tertiary substratum below. beneo (1934) mentions the ancient terraced conglomerates of subiaco, showing a thickness of about 50 m, and the volcanic tuffs widespread in the study area, which, being intercalated in the recent alluvial deposits of the aniene river, can be considered more recent than the subiaco fluvial terraces. devoto (1967) too mentions the pleistocene travertine and lacustrine calcareous tufa deposits filling the incised and extended valleys of the simbrivio and aniene rivers, observing that in the travertine deposits thin calcareous clayey layers are often intercalated, which have been deposited in small lacustrine mountain basins, as proved by their malacofaunal content, represented by bulimus b. tentaculatus limn., bulimus b. leachi (sheppard) and ostracofaunal content, consisting of potamocypris fulva (brady), ilyocipris brady sars, candona neglecta sars, candona (pseudocandona) lobipes hartwic, cypridopsis subterranea (wolf), ilyodromus fontinalis (wolf), ilyodromus olivaceus (br. and norm.), candona cf. acuminata (fisch.), candona cf. procera straub, candona rostrata (br. and norm.). damiani et al . (1998) describe briefly the quaternary deposits occurring in the subiaco area, composed mainly of terraced conglomerates with intercalations of lacustrine episodes, containing remains of plants and mammals, generically attributed to pleistocene, as well as holocene-pleistocene highly weathered volcanic ashes, resting on more ancient volcanoclastic and continental units, including the travertine deposits occurring in several parts of the simbrivio and aniene valleys. 5. morphological and geological features of the calcareous tufa deposits (carrara, verrubbi) 5.1 the simbrivio valley in the simbrivio valley, a right tributary of the aniene river, several small bodies of calcareous tufas occur (damiani et al., 1998). the main ones occur north of vallepietra near fonte acqua delle donne at 830 m a.s.l. and at ponte del tartaro at 785 m, while south of vallepietra other two bodies can be recognized at 20th km of state road sp 45 at case reali locality at 623 m and at brutto colatore locality, 1 km from the convergence to the aniene river at 590 m (fig. 1). the mentioned calcareous tufa deposits are similar for morfological and lithological characteristics. they form depositional coalescing fan-shaped bodies that from the western right steep slope have prograded towards the valley floor, forming a tabular sheet-like terrace that reached the river, encased of a few metres in its overflowing terrace. the progradation of the terrace towards the river, in places, seems to have determined its shifting to east. the surfaces of the terrace is flat and slightly dipping towards the river; the vertical escarpments, 5-6 m high, are visible continuously over distances ranging from some tens of metres to 200-300 m. the depositional terrace consist of superimposed, horizontal or subhorizontal irregularly stratified bodies, composed in the lower part of mainly microhermal lithofacies interfingered with phytoclastic sands and silts and lensoid phytohermal growths. upward they grade to an association of stromatolitic and microhermal lithofacies with intercalations of phytoclastic lithofacies; a few centimetres thick layers, very rich in moulds of leaves (bibliolitic lithofacies) are often associated. from the upper margin of the terrace scarps, thick, lobate, moss phytohermal drapes often hang; in places they can cover the whole scarp wall (fig. 2). the formation of the studied terrace is related to the activity of cool springs issuing on the right steep slopes of the valley; the springs, owing to the deposition of calcareous tufa sediments, have undergone frequent calcareous tufa deposits ... fig. 2 a: the scarp of the calcareous tufa terrace of ponte del tartaro. the deposition of calcareous tufas is still active, the scarp being flowed through by streams of incrusting waters and covered by vertically hanging drapes and festoons of hygrophites, partially calcified. scarpata del terrazzo di travertino di ponte del tartaro. la deposizione di travertino è ancora attiva; la scarpata è, infatti, corsa da ruscelli di acqua incrostante ed è coperta da festoni e drappeggi verticali di vegetazione igrofita parzialmente calcificata. 24 diversions and shiftings of their course, giving place to the formation firstly of braided stream like deposits, then toward the valley bottom of more uniform sheet-like interfingered bodies as reported in other calcareous tufa deposition areas (perched springline model of pedley, 1990; violante et al., 1994; pedley et al., 2003). in the terraces of fonte acqua delle donne and ponte del tartaro the activity of cool springs and the deposition of calcareous tufas still continue. 5.2 the aniene valley upstream of subiaco. in the upper aniene valley, se of subiaco, several small calcareous tufa deposits occur; the main ones crop out at about 1 km upstream from the ponte di comunacque at 550 m and at acqua dei cardellini at 558 m (damiani et al., 1998) (fig. 1). the ponte di comunacque deposit represents a typical fluvial barrage (pedley, 1990) composed of a microphytohermal, massive, some metres high framework, extended from one bank to the other of the river. the downstream wall of the barrage shows a gradine structure, where moss phytohermal vertical drapes associated with laminated, often wavy encrustations occur. the upstream part of the barrage forms a body extending some tens of metres, composed of coarse phytoclastic sands and silts. its inner structure is not visible, owing to the thick vegetational cover, but in some local incisions, which indicate outcrops of microhermal and stromatolitic textures. the calcareous c. carrara et al. fig. 3 still active fan-shaped calcareous tufa body (acqua dei cardellini), prograding and aggrading from the slope to the riverbed, covered by mosses, algae and other hygrophytes. corpo conoidiforme di travertino (acqua dei cardellini) ancora attivo, progradante e aggradante dal pendio al letto del fiume, coperto da muschi, alghe ed altre igrofite. fig. 4 simplified geological scheme of the subiaco area. legend of symbols: 1. iiird order terrace (holocene), 2. iind order terrace (early holocene), 3. ist order terrace (upper pleistocene), 4. alluvial deposits (lower pleistocene), 5. miocene substratum. schema geologico semplificato dell’area di subiaco: 1. terrazzo del iii ordine (olocene); 2. terrazzo del ii ordine (olocene inferiore); 3. terrazzo del i ordine (pleistocene superiore); 4. depositi alluvionali (pleistocene inferiore); 5. substrato miocenico. tufa barrage has undergone at least from the iii-iv century b.c. water diversion and catchment, as well as the cutting of deep and narrow channels for water penstock needed to turn mills. at present the deposit and the ruins of the mentioned works are only partially visible, because of the thick vegetation cover, comprising not only trees and bushes, but also a widespread mat of moss cushions and algae, already partially calcified by the river encrusting waters, herein forming cascades, rapids and whirlpools. the acqua dei cardellini deposit (cardellino is the name given in this region to the surficial, weathered, highly porous and vacuolar part of micro-phytohermal deposits) represents the typical example of a lobate, gradine, fan-shaped calcareous tufa body, genetically linked to an encrusting spring (fig. 3), prograding downslope (violante et al., 1994). its base is about some tens of metres width and several metres thick. it is presently precipitating and prograding, being run by several divergent streams of water and covered almost intirely by a luxuriant vegetation of mosses, algae and other hygrophyte plants. 5.3 the subiaco area in the stretch of the aniene valley comprised of between subiaco and the monastero di s. scolastica, a calcareous tufa deposit exposed on a surface of about 1 km2 and composed of three depositional terraces, occurs (de angelis d’ossat, 1897; damiani et al., 1998) (figg. 4, 5, 6). the ist order terrace consists of two segments occurring respectively on the left and right banks of the river, at the outlet in the subiaco basin. they rest uncomformably as wedge-shaped bodies on the miocene limestone bedrock. the segment on the right bank, on which the monastery is located, shows a vertical scarp of about 70 m (from 510 to 440 m), and a regular, flat surface. other portions of minor dimensions occurr along the road to comunacque, where in places are affected by evident landslide phenomena due to undercutting by the aniene river that, after having cut the entire deposit, at present flows in the limestones of the bedrock. the segment on the left side, wider than the right one, lies partly on the miocene substratum, partly on alluvial deposits related to lower pleistocene (damiani et al., 1998); it shows an even scarp, comprised of between 500 and 440 m in the river gorge and a flat surface in places cut by secondary minor scarps. the most complete section of the deposit is visible along the road rising to monastero di s. scolastica and in the cava segatori locality, where the uncomformable, abrupt contact of calcareous tufas on bedrock is often observable. from a lithological point of view two longitudinal parts of the deposit can be recognized: an inner one, mainly composed of autochthonous lithofacies associations, grading upwards to mainly phytoclastic lithofacies and an outer one, downstream, almost wholly composed of cascade lithofacies. the reconstructed section representative of the inner part of the deposit, is here described (fig. 7). at the base generally horizontal or gently dipping downstream layers of thinly laminated microhermal and stromatolitic lithofacies, from some centimetres to few decimetres thick, resting on a reddish-brown paleosol, outcrop. they can contain many molds of leaves, fru25calcareous tufa deposits ... fig. 5 view of the subiaco calcareous tufa deposit and the relative three orders of depositional terraces. veduta del deposito di travertino di subiaco con i relativi 3 ordini di terrazzi di deposizione. fig. 6 profile sketch (not to scale) of the three depositional terraces of fig. 5. legend of symbols: 1 pedogenized soil colluvium rich in volcanic minerals; 2 cascade moss phytohermal lithofacies; 3 mainly microhermal and phytohermal lithofacies framework. profilo schematico non in scala del deposito di subiaco con i relativi tre terrazzi deposizionali mostrati in fig. 5. legenda: 1 colluvio di suolo pedogenizzato ricco di minerali vulcanici; 2 litofacies fitoermali su muschio di cascata; 3 struttura di sbarramento costituita prevalentemente da litofacies micro e fitoermali grossolanamente stratificate. stules and other parts of plants. in places, however, lenticular bodies of microphytohermal lithofacies showing high vacuolar texture, occur. phytohermal l ithofacies on mosses and macrophytes prevail upwards, in the middle part of the section, where they form massive or coarsly stratified subhorizontal framework. to this phytohermal lithofacies lenticular intercalations of pool infilling phytoclastic calcareous sands and silts2, ranging from some decimetres to several metres in size, are associated. these phytoclastic lithofacies can be organized in massive or thinly laminated layers, showing in places planar cross-bedding structures, slightly dipping towards sw and containing small lenticular or rounded phytohermal cushions. the edges and the bottom of the pools are often coated by thinly laminated lithofacies, often showing microterraced structures. in the upper part of the section grossly stratified sandy and silty phytoclastic lithofacies prevail. they often contain lithified microhermal layers. on the surface of the deposit (ist terrace) a reddish-brown (5yr÷7.5yr), well-developed soil, some metres thick, containing a great quantity of volcanic minerals and highly weathered volcanic rock fragments3, occurs. the outer part of the deposit consists of moss phytohermal lithofacies, that form discontinuous, lobate, vertical curtains and drapes strongly tied to the external walls of the inner part. they have a variable thickness ranging from few decimetres to several metres. they often form landslide accumulations at the foot of the wall (fig. 6). the iind order terrace also occurs on both banks of the river; its surface, dipping gently towards the river, develops at an elevation of about 450 m a.s.l. the scarp of the terrace outcrops only in some sections along the river, at parata under chiesa di s. lorenzo. here, on the right bank of the river, the lower part of the deposit consists of a body, about 20 m thick, characterized by a chaotic structure, composed of phytoclastic, sandy matrix supported calcareous tufa boulders, varying from several cubic centimetres to more than a cubic metre, showing a different orientation (fig. 8). the boulders are mainly made of phytohermal and microhermal lithofacies; laminitic lithofacies are less widespread. the upper surface of this chaotic body is strongly eroded and is cut by deep, large channels and pools, filled with stratified, calcareous phytoclastic sands, in places associated with thin laminitic concretions and small phyto-microhermal lenses. these sediments lie uncomformably on the chaotic body at the base. the described lithofacies association grades in the uppermost 2-3 metres to laminated silts, containing thin, brown-blackish clayey layers. the chaotic body could represent an intraformational landslide or a local accu26 c. carrara et al. fig. 7 section of s. scolastica, subiaco (not to scale). legend of symbols: 1. pedogenized soil colluvium rich in volcanic minerals; 2. phytoclastic sands and silts; 3: mainly microhermal lithofacies; 4. mainly stromatolit ic laminites, microhermal and bibliolitic lithofacies; 5. massive or coarsely stratified phytohermal lithofacies; 6. reddishbrown soil; 7. calcareous miocene substratum. sezione di s. scolastica, subiaco (non in scala). legenda: 1. colluvio di suolo pedogenizzato ricco di minerali vulcanici; 2. sabbie e limi fitoclastici; 3. prevalenti litofacies microermali; 4. prevalenti litofacies laminitiche, microermali e bibliolitiche; 5. litofacies fitoermali massive o grossolanamente stratificate; 6. suolo rossobruno; 7. substrato calcareo miocenico. 2 they are mainly composed of fragments of microcrystalline calcite and micritic fitoclasts, few fragments of mollusc and ostracods and rare volcanic minerals. 3 well developed, acalcareous, reddish-brown soil, showing prismatic structure and containing clayey cutans and fe-mn striations; the skeleton is composed of angular fragments of limestone and dense tufa. the volcanic content ranges up to 40% and more of the rock and is represented in decreasing order by prismatic blackish pyroxene, large biotite plates, prismatic sanidine and rare leucitic grains. mulation of heterometric blocks of a preceding dismantled deposit. it does not occur on the left scarp of the terrace. it is worth noting that the iind order terrace surface is covered by a reddish-brown (5yr÷7.5yr) pedogenized silty-clayey colluvium, 1-2 m thick, lacking volcanic material, or containing a very poor fraction of such material, not comparable to that contained in the soil developed on the ist order terrace body. the iiird order terrace, whose discontinuous scarp is comprised of between 400 and 385 m, consists of a larger part, occurring on the right side of the river, at present completely covered by the recent buildings of subiaco, and of a narrow strip along the left side of the river under the s. lorenzo iind order terrace scarp. the iiird order terrace is poorly exposed; only discontinuous and small outcrops can be seen on its scarp along the river. vacuolar, microand phytohermal lithofacies, associated with thinly laminated bands, rich in moulds of leaves and small frustules, can be observed; they are associated with irregularly distributed stromatolitic lithofacies and pool infilling phytoclastic sands and silts; in places they are covered by small moss cascade curtains. on the iiird order terrace surface a brown (7.5yr), calcareous soil, devoid of volcanic material, occurs. the morphological and structural features of the described terraces suggest their depositional origin. the deposit has been deeply cut and dissected by the river, during non depositional and/or strong erosional phases. moreover, the calcareous tufa deposit of subiaco has been particularly affected by strong karstic processes, that developed mainly along fracture systems and the cavities left by decayed organic matter of plants. therefore, a very complicated and variable set of channels, cavities and caves formed; in general they are coated by laminar concretions of sparry, alabastrine calcite and by speleothems of variable sizes. on the bottom of some cavities thinly laminated, gray-greenish silty-clayey sediments, containing fragments of terrestrial gastropods, occur. the framework and the distribution of the associations of lithofacies described suggest a depositional model typical of fluvial barrage (buccino et al., 1978; pedley, 1990; carrara et al., 1995). at the outlet of subiaco basin, where the aniene valley was deepest and narrowest, the river met a morphological structure, tectonically controlled (the presence of transverse faults is reported in damiani & pannuzi, 1981; damiani et al., 1998), that caused a variation of the river flow and of the water turbulence. the obstacle triggered, therefore, the precipitation of calcium carbonate and the formation of the calcareous tufa barrage. this process was associated with the activity of many different macroand microorganisms that contributed to tufa deposition, as reported by several authors (carrara, 1991, golubic et al., 1993; farabollini et al., 1994; pedley, 2000; pedley et al., 2003). upstream the barrage, a well vegetated, palustrine to shallow fluvio-lacustrine environment formed, characterised by the deposition of laminated and microphytohermal and phytoclastic bodies, rich in moulds of leaves and parts of plants. afterwards a massive, phytohermal framework, with complex intercalations of pool infilling phytoclastic lithofacies, grew up. at the same time, on the barrage front cascade lithofacies deposited vertical curtains and drapes. 5.4 marano equo deposit (branca, voltaggio) the morphological depression of marano equo formed in early pleistocene as the result of the extensional tectonics which affected the late miocene-early pliocene units in the central appennines thrust belt. lithostratigraphical, compositional and paleontological analyses on sediment cores, from 8 continous boreholes 62.5 to 155 m deep drilled on behalf of the acea firm, suggested (branca et al., 1995) that the sedimentary sequence accumulated in notably different depositional environments rather than under uniform conditions. the coarse lithofacies, represented by conglomerate intervals and breccia episodes are related to a paleo-aniene river transport and erosion of rimming reliefs, respectively. sandy and clayey muds, along with humified and peaty levels record fluvial braided-plain events. lithoid tufas and calcareous sands point to the occurrence of formerly active springs issuing bicarbonate-enriched waters. in a core, 145 m deep, containing alternating sands and clayey muds, a calcareous tufa horizon 15 meter thick has been crossed. it extends from -64 m to – 50 m; two samples were collected from -59 level (su4-51) and -52 level (su452)(see chap. 7 and tab. 1). 27calcareous tufa deposits ... fig. 8 scarp of the iind order terrace at parata. in the lower and right side of the picture landslide body made mainly of phytohermal and microhermal boulders (a); in the middleupper part pools filling phytoclastic sands and silts (b); laminar textures bound an erosional surface (solid line). località parata: scarpata del terrazzo del ii ordine. nella foto in basso corpo di frana ad elementi di travertino (a); nella parte medio-alta vasche di limi calcarei fitoclastici (b) con tessiture laminitiche che limitano una superficie di erosione (linea continua). 5.5 the mandela-vicovaro area in the mandela-vicovaro area, a uniform, continuous, depositional, calcareous tufa deposit occurs, extending for about 3 km, from stazione di mandela to monastero di s. cosimato, as far as some hundreds of metres downstream vicovaro (figg. 9, 10). the deposit is bounded on the southern side by the aniene river, where its scarp follows closely the morphology of the valley, widening out as far as 450-500 m near s. cosimato and getting narrower where the valley forms a very incised gorge. on the northern side the deposit is limited by the licenza stream, right tributary of the aniene river. the stream has deviated its lower course from north-south direction to east, flowing counterslope into the aniene river at about 2 km eastward, due to emplacement of volcanics (bieler chatelain, 1929) and alluvial deposits near vicovaro, followed by the growth of the mandela-vicovaro calcareous tufa deposit. the two streams have deeply cut the terraced deposit, reaching the miocene calcarenitic substrate and exposing the inner structure of the deposit in several vertical sections, varying in thickness from a few tens of metres to 60-65 m. the surface of the deposit, at a mean elevation of 350 m, is flat and regular, in spite of the dissection by several tributaries on the right side of the aniene river and of the human activity. one of the more complete sections of the tufa deposit occurs at monastero di s. cosimato (fig. 11). the section goes down from 340 m to the river, at 275 m, near the acea artificial dam at 275 m, where it is possible to observe the abrupt contact of the tufas on 28 c. carrara et al. fig. 9 simplified geological scheme of the mandela-vicovaro area: 1. outcropping calcareous tufas (late glacial-holocene); 2. calcareous tufas covered by colluvials; 3. miocene substratum. schema geologico semplificato dell’area di mandela-vicovaro: 1. travertino in affioramento (tardoglaciale-holocene); 2. travertino coperto da colluvi vari; 3. substrato miocenico. fig. 10 partial view of the mandela-vicovaro terrace. veduta parziale del terrazzo di mandela-vicovaro. 29calcareous tufa deposits ... the bedrock and to recognize two distinct depositional lithofacies associations. the first one represents the whole thickness of the calcareous tufa deposit and shows a planar, coarsely stratified structure; the second lithofacies association forms a thick, vertical or subvertical complex closely draped to the walls of the scarp along the river. the basal portion of the first association is mainly composed of microhermal laminar lithofacies that form thin, wavy layers, often separating small, lensoid phytomicrohermal cushions. pool infilling phytoclastic sands and silts, in places ruditic, as well as rich bibliolitic lithofacies can be found as irregular, lenticular intercalations. the described associations grade upwards to mainly phytohermal, massive or poorly stratified framework, often interfingered with pool filling phytoclastic sands and silts, ranging from a few to dozen metres in extention and a few metres in thickness. these phytoclastic lithofacies contain several brown (7.5yr) clayey, levels, which often show a subhorizontal wavy lamination, planar cross-bedding structures and internal erosional surfaces (fig. 12). silty lithofacies are rich in fresh-water fauna, particularly in the area of stazione di mandela (see 5.5). the second depositional association of the calcareous tufa deposit is composed of moss phytohermal fig. 11 section of s. cosimato (not to scale). legend of symbols: 1. reddish-brown soil; 2. strongly diagenized silts; 3. phytoclastic sands and silts rich in molluscs; 4: mainly microhermal lithofacies; 5. unbedded mainly phytohermal lithofacies; 6. stromatolitic laminites and microhermal and bibliolitic lithofacies; 7. coarsely stratified microhermal and phytohermal lithofacies; 8. calcareous miocene substratum. sezione di s. cosimato (non in scala). legenda: 1. suolo rosso-bruno; 2. limi fortemente cementati; 3. sabbie e limi fitoclastici ricchi di molluschi; 4. prevalenti litofacies microermali; 5. prevalenti litofacies fitoermali non stratificate; 6. laminiti stromatolitiche e litofacies microermali e bibliolitiche; 7. litofacies microermali e fitoermali massive o grossolanamente stratificate; 8. substrato calcareo miocenico. fig. 12 thinly laminated calcareous sands and silts, filling a large pool and containing brown colluvial levels, showing erosional surfaces. sabbie e limi calcarei sottilmente laminati di riempimento di vasca, contenenti livelli bruni colluviati, interessati da superfici di erosione. lithofacies, forming lobate curtains and drapes, ranging from a few metres to some tens of metres in thickness, that hang vertically from the scarp of the deposit and in places cover a great part of it (fig. 13). this cascade lithofacies is particularly widespread in the steepest and deeply incised sector of the river valley, extending from monastero di s. cosimato and some hundred metres downstream from acea dam. another interesting section of the deposit can be observed just south of vicovaro, where the terrace has been cut deeply by the right tributaries of the aniene river. the section has a thickness of about 30 m and is mostly composed of a massive phytohermal lithofacies, covered in the upper part by laminated stromatolitic lithofacies, forming wavy layers, gently dipping towards the river. the basal portion of the section, a few metres in thickness, shows planar micro-phytohermal lithofacies, separated by laminated microhermal intercalations, a few centimetres thick. at the base of the section, stratified alluvial deposits, composed of well reworked, carbonate pebbles, several metres thick, occur. in the basal portion of the mandela-vicovaro deposit the lithofacies associations are indicative of a paludal depositional environment, characterized by still or slightly running waters. in the middle-upper portion of the section the observed lithofacies associations seem to reflect a fluvial barrage model (d’argenio & ferreri, 1986; pedley, 1990, carrara et al., 1995), grading upstream to a well vegetated fluvio-lacustrine environment, composed of large pools, filled with phytoclastic lithofacies, containing a very rich fresh-water fauna. the second depositional phase is composed of typical cascade lithofacies associations, that were deposited on the threshold of the scarp, as the deepening river cut it down. in the mandela-vicovaro area the calcium carbonate precipitation process was probably triggered by a morphotectonic structure, located just south of vicovaro, where a fluvial barrage body has been recognized. it could have formed near vicovaro, where the emplacement of middle pleistocene volcanics, superimposed by younger, coarse alluvial sediments produced a morphologic discontinuity in the river bed. later on, during non depositional and/or strong erosional phases, the deposit has been deeply cut and dissected by the aniene river and its right tributaries. moreover, during the cutting down process, the river left several niches of alluvial deposits encased in the calcareous tufas, at different altitudes on the present thalweg, well visible along the tiburtina road in the vicovaro area. they generally consist of horizontally stratified gravels and conglomerates, a few metres in thickness, composed of phytohermal tufa fragments and well reworked, in places graded and imbricated, siliciclastic matrix supported limestone pebbles. the mandela-vicovaro deposit also underwent intensive karstic processes, that caused the formation of cavities and caves, coated by laminated sparry calcite incrustations and speleothems, of remarkable dimensions. some of them, particularly in monastero di s. cosimato area, were inhabited by hermits in medieval times. 30 c. carrara et al. fig.13 a: mandela-vicovaro scarp terrace under the a24 motorway. a: horizontally grossly stratified, phytohermal and microhermal lithofacies; b: cascade lithofacies, subvertically hanging from the edge of the terrace scarp (solid line). b: profile sketch (not to scale) of the mandela-vicovaro deposit of fig. 13a. a: la scarpata della placca di travertino di mandela-vicovaro sotto l’autostrada a24. a: banchi orizzontali, grossolanamente stratificati, di associazioni fitoermali e microermali; b: associazioni di cascata, subverticali, appese alla scarpata del terrazzo (linea continua). b: profilo schematico non in scala della placca di travertino di mandela-vicovaro di fig. 13a. b a 31calcareous tufa deposits ... 6. faunal assemblages and palaeoecological considerations (e. pisegna cerone) the study of the faunal content of the calcareous sands and silts cropping out near mandela railway station allowed the identification of the following mollusc species: class gastropoda subclass prosobranchia pomatias elegans (müller, 1774) bithynia leachi (sheppard, 1823) subclass heterobranchia valvata cristata müller,1774 valvata piscinalis (müller,1774) subclass pulmonata carychium minimum müller,1774 carychium tridentatum (risso, 1826) lymnaea palustris (müller, 1774) planorbis planorbis (linneo, 1758) gyraulus laevis (alder, 1838) hippeutis complanatus (linneo, 1758) oxyloma elegans (risso, 1826) punctum pygmaeum (draparnaud, 1801) discus rotundatus (müller, 1774) oxychilus draparnaudi (beck, 1837) oxychilus cellarius (müller,1774) macrogastra plicatula (draparnaud, 1801) clausilia dubia draparnaud, 1805 hygromia cinctella (draparnaud, 1801) class bivalvia subclass heterodonta pisidium amnicum (müller, 1774) the palaeoecological analysis of the species has been carried out according to the method elaborated by ložek in 1964 for the study of the quaternary nonmarine molluscs of czechoslovakia. thanks to this methodology every considered species is part of an ecological class indicated by marks formed by the number of the ecological group and the abbrevation of the belonging biotope. the marks used in this work are: wood species 1w: species linked exclusively to wooded places; 2w(m): species living mainly in woods, but which can also live in mesophylous areas in mean moist localities and moist or dry biotopes. species living in wood as well as in open lands with different needs of moisture 7m: mesophylous species mainly distributed in mean dry places, but which can live in moist as well as dry biotopes; 8h: species fond of moisture, but not linked to clearly wet biotopes; 7wf: species living in woods or on mean moist rocks. terrestrial marsh species and aquatic species 9p: species living in marshes, in wet grasses, in highly moist to particularly wet biotopes, mainly near water; 10p: aquatic species living in shallow water, marshes rich in vegetation; 10s: aquatic species living in still water, from small pools and bogs to ponds and lakes; 10sf: species living in still or running water; 10f: aquatic species living in running water, from streams to rivers. the following symbols have been associated to ecological marks: !: species indicative of warm-moist intervals; !!: species characteristic of warm-moist intervals; (+): species occurring locally in loess. index of species and their habitat gastropoda pomatias elegans (müller, 1774) habitat: it is a mesophylous, almost exclusively calcicole species; it rarely occurs on calcareous substratum. it lives on dry slopes, between shallow bushes, dead leaves, along fences, seldom on stream banks, at the borders of woods (ehrmann, 1956; settepassi & verdel, 1965; kerney & cameron, 1979). ecological marks according to ložek (1964): 2w(m)!! bithynia leachi (sheppard, 1823) habitat: it lives in still or slightly running waters, in lakes, ponds, marshes; it is not particularly demanding. it occurs in mesohaline waters with salinity up to 6‰ (girod et al., 1980). ecological marks according to ložek (1964): 10p valvata cristata müller,1774 habitat: it lives in still, shallow, clear and clean waters, rich in vegetation, on leaves and stalks of aquatic plants (settepassi & verdel, 1965), also in marshes and ditches (ložek, 1964), in slowly flowing water (ehrmann, 1956) or in lakes, on pebbly bottoms with plenty of mud (girod et al., 1980). it occurs in mesohaline waters with salinity up to 12‰ (girod et al., 1980). it reaches a depth of 20 m and an elevation of more than 100 m (settepassi & verdel,1965). ecological marks according to ložek (1964): 10p valvata piscinalis (müller,1774) habitat: it lives in still or slightly running waters: lakes, ponds, springs, channels and marshes (girod et al., 1980). it can live up to 50 m in depth, but generally it can be observed within the first 20 m (girod et al., 1980); in lakes it reaches -80 m (ehrmann, 1956). it can be found up to 1000 m elevation (girod et al., 1980) and tolerates a maximum salinity of 4‰ (ehrmann, 1956). ecological marks according to ložek (1964): 10sf carychium minimum müller,1774 habitat: it lives in moist areas such as marshes, woods, grasses, especially in plains and low mountainous places (kerney & cameron, 1979). ecological marks according to ložek (1964): 9p carychium tridentatum (risso, 1826) habitat: it is a less hygrophilous species than carychium minimum. it does not live in marshes, but it occurs in moist grasses, in woods, in bushes, under dead leaves, in well sheltered places. it also lives in hilly and mountainous areas (settepassi & verdel, 1965; kerney & cameron, 1979). ecological marks according to ložek (1964): 8h lymnaea palusris (müller, 1774) habitat: it lives in shallow waters such as ponds, marshes, bogs, streams, ditches, rarely in rivers; it occurs also on the shores of some lakes (girod et al., 1980). ecological marks according to ložek (1964): 10p(+) planorbis planorbis (linneo, 1758) habitat: it lives in calm or slightly flowing waters within acquatic vegetation, on muddy bottoms (girod et al., 1980). ecological marks according to ložek (1964): 10p(+) gyraulus laevis (alder, 1838) habitat: it lives in ponds, ricefields, streams and channels (girod et al., 1980). ecological marks according to ložek (1964): 10s hippeutis complanatus (linneo, 1758) habitat: it lives in lakes, along the coast in places with sandy and muddy bottoms, sheltered from floods, in ponds and marshes (girod et al., 1980). ecological marks according to ložek (1964): 10s oxyloma elegans (risso, 1826) habitat: it lives along the banks of rivers, ditches, lakes, ponds and marshes (settepassi & verdel, 1965; kerney & cameron, 1979). ecological marks according to ložek (1964): 9p punctum pygmaeum (draparnaud, 1801) habitat: it prefers mean moist localities. it occurs generally under leaves and wood, but also in open regions, on rocks, in moist grasses, in shady and fresh places (esu, 1978). ecological marks according to ložek (1964): 7m(+) discus rotundatus (müller, 1774) habitat: it lives in moist places, in woods, at the bottom of trees, among dead leaves, in wet grass, under stones, in the fissures of walls (settepassi & verdel, 1965; kerney & cameron, 1979). ecological marks according to ložek (1964): 2w(m) oxychilus draparnaudi (beck, 1837) habitat: it lives in woods and among rocks (kerney & cameron, 1979). ecological marks according to ložek (1964): 7m! oxychilus cellarius (müller,1774) habitat: it lives in underbrush environments among rocks (kerney & cameron, 1979). ecological marks according to ložek (1964): 7m! macrogastra plicatula (draparnaud, 1801) habitat: it lives in litter or among decaying beechwoods (giusti et al., 1985), rocks, generally in moist and shady places; it can reach 2000 m elevation on swiss alps (kerney & cameron, 1979). ecological marks according to ložek (1964): 1w! clausilia dubia draparnaud, 1805. habitat: it lives on rocks or walls, rarely in woods (kerney & cameron, 1979). ecological marks according to ložek (1964): 7wf(+) hygromia cinctella (draparnaud, 1801). habitat: it lives in woods, hedgerows, in moist environments (banks of brooks) on slopes with fresh vegetation (kerney & cameron, 1979). ecological marks according to ložek (1964): 2w(m) bivalvia pisidium amnicum (müller, 1774) habitat: it lives in rivers, channels, brooks, ponds and lakes, up to 40 m in depth, in waters mildly rich in calcium carbonate, on muddy or fine sandy bottoms. it occurs in water with salinity comprised between 0,5 and 3‰ (castagnolo et al., 1980). ecological marks according to ložek (1964): 10 f data analysis palaeoecological considerations the analyzed sediments contain a very rich mollusc assemblage composed of aquatic species of fluviolacustrine environment and of terrestrial gastropods for a total of 19 species. moreover some ostracods and vegetal remains also occur. among gastropods many species belonging to prosobranchs, heterobranchs and pulmonates have been recorded; one species of bivalve also occurs in the assemblage (fig. 14). the mollusc fauna is composed mainly by fresh water species, such as bithynia leachi, valvata cristata, valvata piscinalis, lymnaea palustris, planorbis planorbis, gyraulus laevis, hippeutis complanatus and pisidium amnicum. among them the dominance of valvata piscinalis, characteristic of slightly flowing waters, has been observed. this species reaches 55.93% representing the most widespread species in the examined sample. the abundance of several species living in ponds and lakes shows variable percentages ranging from 11.19% (valvata cristata), to 10.51% (planorbis planorbis), 5.15% (bithynia leachi) and finally 0.67% (lymnaea palustris). the species hippeutis complanatus and gyraulus laevis also prefer to live in ponds and lakes and show, respectively, the following percentages: 0.67% and 1.34%. 32 c. carrara et al. 33calcareous tufa deposits ... the bivalve pisidium amnicum, reaching 0.89% in abundance, prefers channels and rivers, actually resulting to be a good indicator of running waters. moreover, species of moist and open environments, such as the strongly hygrophilous oxyloma elegans reaching 0.67%, carychium tridentatum and carychium minimum, both reaching 0.22%, have been recorded. the species punctum pygmaeum, oxychilus draparnaudi and oxychilus cellarius, occurring in relatively low percentages, respectively 3.36%, 0.22% and 2.01%, prefer underbrush environments, but can live also in open lands. among the wood species macrogastra plicatula has been noted. it is associated esclusively to woody places and occurs in the low percentage of 0.67%. other species such as pomatias elegans (3.58%), discus rotundatus (2.24%), hygromia cinctella and clausilia dubia (both reaching 0.22%), prefer the border areas of woods. the study of the recovered malacological assemblage, characterized by the dominance of proper aquatic species, as well as by highly hygrophilous species and by terrestrial ones loving woody environments, allows the reconstruction of a palaeoenviroment typical of moist wood, open in places, in the presence of a shallow water-body, rich in vegetation, such as pond and small lake. it is possible, moreover, to suppose, on the basis of the richness of the mollusc assemblage, of the occurrence of some species indicative of temperate-warm climatic phases and of the above described palaeoecological observations related to the species, that the climate was temperate. it is not possible to infer any chronostratigraphic consideration, as all the recorded species are still living and occur in italy at least from the beginning of the pleistocene. 7. chronostratigraphy and paleoclimatic outlines (m. branca, c. carrara, m. voltaggio) nine samples from the subiaco deposit, four samples from the vicovaro-mandela one and two samples of a core from the marano equo buried body were chosen for chronological determinations by the 230th/234u method. elementary and isotopic composition of uranium and thorium was determined by a-spectrometry following the method of gascoyne et al. (1978). seven samples showing a high content of detritic not-radiogenic thorium were analyzed also for the non carbonate fraction and corrected ages were computed using the correction method of ku and liang (1985) (tab. 1). fig. 14 palaeoecological diagram of the malacological association of mandela station. spettro paleoecologico dell’associazione malacologica della stazione di mandela. 34 c. carrara et al. tab. 1 u/th dating of marano equo, subiaco and mandela-vicovaro tufa deposits. datazioni u/th di campioni dei depositi di travertino di marano equo, subiaco e mandela-vicovaro. * subiaco r = residuo residue ° mandela-vicovaro l = liscivato leachate ˆ marano equo c = valori corretti correct values the samples from the marano equo core sampled at -52 (su 51) and -59 metres (su52) were analyzed by tims mass spectrometry using a finnigan mat 62 + rpq mass spectrometer and this accounts for the minor errors associated with their measurements. the two samples gave ages of 112 ±7 and 109±3 kyr. the samples of the ist order terrace of subiaco (su3, su12, su12c, su19, su20a, su34, su35) were picked up from different sections that, due to the great variability of tufas, the very irregular pattern of the substratum and the lack of marker beds, cannot be correlated, nor on the basis of precise altitude. dated samples were chosen from phytoand microhermal lithofacies or from stromatolitic laminites, generally lacking of late diagenetic cements or clear recrystallized portions. the samples of the ist order subiaco terrace, collected from the lower and middle parts of the body, gave the following ages: 64.8 ± 4.5, 35.2 ± 2.2, 23.2 ± 1.3, 19.3 ± 1.0, and 17.9 ±1.0 kyr. a sample of a crystalline calcareous crust collected near s. scolastica monastery within the silts near the surface of the terrace gave 4.2 ± 0.2 kyr. this age could represent the age of a late deposit, linked to local, ephemeral circulation of encrusting waters still visible at present. the mean deposition rate for the ist order subiaco terrace body, considering an average apparent density equal to 1.74 ±0.2, is of 0.19 g mm-2 a-1, a value comparable with other quaternary italian calcareous tufa plates (fig. 15). from the body of the iind order terrace two samples of stromatolitic laminites have been dated: 9.4±0.5 e 7.2±0.3 kyr. no samples of the iiird order terrace have been dated, because the lacking of favorable facies to dating. the subiaco calcareous tufa deposit can be related, therefore, to upper pleistocene-holocene. in detail, the ist order terrace could have been formed during the upper pleistocene, while the iind order terra35calcareous tufa deposits ... fig. 15 deposition rate and mean apparent density of quaternary travertine deposits of italy. data from this work and from faccenna et al.,1994. tasso di deposizione e densità media apparente dei depositi di travertino quaternari in italia. dati di questo lavoro e da faccenna et al., 1994. ce seems to have an upper holocene age. from s. cosimato monastery in the mandelavicovaro deposit four samples (su 21, su21a, su22, su23) were collected and dated, their ages being : 15.8±1.3, 11.6±0.6, 10.2±0.7, and 5.5±0.3 kyr. the beginning of the deposition of this deposit have started, therefore, from late glacial to middle holocene. its mean deposition rate, considering an average apparent density of 1.49, is of 0.94 g mm-2 a-1, the highest value among quaternary italian travertine deposits (fig. 15) but comparable to other holocenic calcareous tufas of the world (pazdur et al., 2002; kano et al., 2004). the fast erosion of the vicovaro gorge during the last 5 kyr was likely accelerated by the acidity of many springs that in the sector between marano equo and mandela are at present enriched in h2s (i.e. campo oreella). also the occurrence of at present still active co2 degassing zone at 12 km from vicovaro along the aniene river (between roviano and marano equo) probably contributed in the past to lower the calcium carbonate oversaturation of the depositing waters. the variation of the co2 and h2s degassing rates also explain the discontinuity over space and time of the deposition of calcareous tufa in the marano equo site. presently in the subiaco-vicovaro fluvial segment the eventual erosion is only of a physical nature because in this segment the aniene waters are oversaturated in calcium carbonate even if the calcium carbonate oversaturation factor ω decreases notably from subiaco to vicovaro (tolomeo l. pers. communication). from chronostratigraphic data reported previously, the following evolution phases of the subiaco tufa deposit can be recognized: ist depositional phase: growth of the tufa barrier; formation of the ist order terrace, as far as the elevation of 500-510 m; ages comprised of between 64.8±4.5 and at least 17.9±1.0 kyr. emplacement of soil colluvium rich in volcanic minerals on the surface of the terrace. erosional phase: cut down of the ist order terrace as deep as 450 m, comprised between 17.90 ± 1 and 9.4 ± 0.5 kyr. iind depositional phase: formation of the iind order terrace body with surface at 450 m; ages comprised of between 9.4 ± 0.5 and at least 7.2 ± 0.3 kyr. erosional phase: cut down of the iind order terrace as deep as 400 m, more recent than 7.2 ± 0.3 kyr. iiird depositional phase: formation of the iiird order terrace body with surface at 400 m a.s.l.; age undetermined. erosional phase: cut down of the iiird order terrace as far as the present river bed, still in progress. from this evolution scheme it follows that the deposition of calcareous tufa in the area of marano equo preceeds the formation of the ist order subiaco terrace, whereas the mandela-vicovaro tufa deposit seems to be more or less contemporary of the formation of the iind order subiaco terrace body, beginning in the late glacial (15.8 ± 1.3) and continuing during the early-middle holocene (11.6± 0.6, 10.2±0.7, 5.5±0.3). comparing the ages of the studied tufas with the isotopic curves (ravazzi, 2003), cautiously keeping in mind the method error, it is possible to draw some paleoclimatic considerations. the formation of the buried plate of marano equo (112 ±7, 109± 0.3) took place during the mis 5d, a substage of the last interglacial (fig. 16) characterized by a climate deterio36 c. carrara et al. fig. 16 dated samples of marano equo, subiaco and mandela-vicovaro calcareous tufa deposits inserted in the framework of late pleistocene chronologic and climatostratigraphic reference units used in europe (from ravazzi, 2003, modified). campioni datati dei depositi di marano equo, subiaco e mandela-vicovaro inseriti nello schema cronologico e climatostratigrafico delle unità di riferimento europee (da ravazzi, 2003, modificato). ration. the formation of the lower part of the subiaco deposit took place during mis 4 (64.8±4.5), in correspondence to the gap between greenland interstadial 18 and 19, characterized by a deterioration of climate if compared to the last interglacial. the middle part of the deposit falls into the mis 3 (35.2 ±1.2, 34.3±2.2), between the greenland interstadials 8 and 9, while the middle-upper part is comprised in the mis 2 (23.2±1.3, 19.3±1.0, 17.9±1.0), the two stages being characterized by great climatic variability. the depositional phase of the iind order terrace body (9.4±0.5 and 7.2±0.3) occurred in the mis1, in the early holocene, characterized by a decise climatic amelioration (thermal optimum). the mandela-vicovaro deposit begins to form during mis2, in the late glacial (15.8±1.3) in correspondence to the greenland stadial 2, characterized by the beginning of alpine deglaciation, then continuing in the early and middle holocene (11.6±0.6 ,10.2±0.7, 5.5±0.3), during thermal optimum. the deposition of calcareous tufas in the studied area seems to have been active in spans of time characterized by opposing climatic variations: not only during warm and wet stages (interglacials or interstadials), generally more favorable to calcium carbonate deposition, as already pointed out by a very wide literature (see for example gordon et al., 1989), but also during temperate and wet stages, as already mentioned in other works (carrara 1994, 1998, carrara et al., 1998) and proved by malacological content of sandysilty sediments. the age frequency histogram for 64 samples of central italy travertines deposited in the last 150 kyr (62 dated by 230th/234u method in the u-th geochronology laboratory of igag-cnr during the 1988-2005 period) (fig. 17) shows clearly that the growth frequency is indipendent of the temperature. conversely, considering the temporal evolution of the accretion rate of coeval speleothems (calculated on about 70 samples from the frasassi cave), a parameter which is directly proportional to the pluvial regime, we can note how the growth frequency of calcareous tufas is correlated with it. it is therefore probable that, at our mid latitudes and altitudes, the calcium carbonate precipitation process from continental waters is influenced more by the “degree of humidity” of that moment in that area, rather than by variations of temperature and that the deposition of calcareous tufas stops fully only during the cool and /or warm but dry intervals, while it undergoes a decrease or an increase during the intermediate ones. 37calcareous tufa deposits ... fig. 17 age frequency histogram of central italy travertines: v samples = vulsini (taddeucci & voltaggio, 1987); t samples = tivoli (faccenna et al., 1994); r samples = rocchetta al volturno (brancaccio et al., 1988); g samples = gallicano (funiciello et al., 1992); l = liri (carrara, 1991); mv samples = mandela-vicovaro (this work); s samples = subiaco (this work), me samples = marano equo (this work); sa samples = sabatini and rm = roccamonfina (cnr-igag, u/th laboratory), unpublished. frasassi data are from taddeucci et al., 1992. istogramma di frequenza delle età dei travertini dell’italia centrale: v campioni = vulsini (taddeucci & voltaggio, 1987); t = tivoli (faccenna et al., 1993); r = rocchetta al volturno (brancaccio et al., 1988); g = gallicano (funiciello et al., 1992); l = liri (carrara, 1991); mv = mandela-vicovaro (questo lavoro); s = subiaco (questo lavoro), me = marano equo (questo lavoro); sa = sabatini and rm = roccamonfina (cnr-igag, u/th laboratorio, non pubblicati. i dati di frasassi sono da taddeucci et al., 1992. discussing about paleoclimate problems, orombelli & ravazzi (1996) write: ”the variations in the hydrologic balance, particularly in the areas that are presently arid and hyperarid, had a much greater role in the environmental changes during the holocene, compared to the role played by temperature variations”. as regards to the deposition of calcareous tufas we think that the same phenomenon also counts for less dry areas and other quaternary periods. comparing the chronology of the studied deposits and the pre-protostoric peopling of the middle aniene valley that took place between the middle paleolith and the final bronze age, in places near the river and concentrated in the widest areas of the valley (festuccia & zabotti, 1992), a close relationship between the two events seems to be recognized. the occurrence of springs and the relative calcareous tufa deposits could have favoured the mentioned peopling. such a relationship, moreover, has been observed in other italian archeological sites, in areas rich in spring waters depositing calcareous tufas, exploited by man for agricultural, domestic and cult purposes (carrara, 2002). field observations on considered deposits have not allowed the recognition of sure evidence of postdepoditional neotectonics. the bedding attitude of the calcareous tufa bodies in the basal and proximal parts generally follows the substratum palaeomorphology, while they get horizontal or subhorizontal in the middle and distal parts. several open fractures and normal faults with displacements up to a few centimetres have been observed. nevertheless, such structures seem to be interpreted as mainly due to slope instability and the high vertical faces cut in the deposits. this is also suggested by the presence of frequent and great synsedimentary and postdepositional landslides (see 5.3). landslide events, probably cosismic, that affected the studied areas were recognized during excavations carried out by soprintendenza archeologica del lazio between 1994 and 1996 in the portion of the neronian villa where s. clemente monastery was located (fiore cavaliere & mari, 1996). other slope instability phenomena in the calcareous tufa bodies, where s. scolastica monastery is located, have been reported by molin et al. (2002). the quaternary morphotectonic evolution of the area has certainly conditioned the location and the deposition of studied calcareous tufas (see chap. 2); during and after their deposition the deposits have undergone strong erosion and quick incision events (see chap. 7), due to complex interactions between the uplifting of the area and the variations of the base level in their turn connected to climatic variations. to better understand such interactions, detailed studies on the quaternary geologic and geodinamic evolution of the whole aniene valley and adjacent areas would be necessary. 8. geoarcheological considerations (c. carrara, v. verrubbi) the name of subiaco derives from latin sublaqueum, term used by some latin writers to indicate the area where a great villa was built up by nero in the first years of his rein (54-68 a.d.) and some artificial lakes close to it (“lacus treis, amoenitatem nobiles, qui nomen dedere sublaqueum” pliny the elder; “ex lacu qui est super villam neronianam sublaquensem” frontinus; “in villa cui sublaqueum nomen est” tacitus (from carosi, 1956). the mentioned villa was localized in part on the right side of the aniene river, where at present there is the monastero di s. scolastica, in part on the left side at pianello locality. both these places are at 500-510 m and occur on the surface of the ist order terrace; they were connected by a road going from the right side of the river to pianello on the left side, then descending towards chiesa di s. lorenzo on the surface of the iind order terrace. near the villa and in the subiaco area one or more lakes (at least three according to pliny the elder) existed; their number, width and position have been long discussed by many archeologists. among them carosi (1956), orlandi (1984-88, 2002) and quilici (1996) have carried out a detailed, critical examination of ancient sources as well as of extant archeological ruins description and topographical localization. carosi (1956) suggests that the lakes were three, supported by three different artificial dams built up by nero. he is certain that a dam was “where at present the ponte s. mauro occurs, slightly to the west”; this dam, according to his estimate, was about 60 m high and at most about 20 m large, the altitude of the lake level could be around 459 m. the author suggests, moreover, that the other two dams, were next to the present ponte rapone at an elevation of about 450 m a.s.l. and the other next to the ponte s. antonio, at 400 m. orlandi (1984-1988) also debates in detail the neronian constructions and the existence of the three lakes, of which the highest, localised under the speco di s. benedetto, at ponte s. mauro, was certainly “the more extensive in lentgh and surface”; the lake level could not be less than 60 m over the river bed. some important remains of the dam, still in situ on both sides of the ponte s. mauro, and large ruins along the bottom of the river, are described. the author also reports the description of another neronian lake contained in “a letter written during the stay at subiaco of pope innocenzo the iiird, in 1202, by a member of the papal court”. he writes that the described lake must not be confused with the highest one and “must be searched far down, near the present subiaco”. the dam was probably localized near the cartiera di subiaco, at ponte s. antonio, and the depth of the lake has been estimated of about 27 m. this lake was probably separated by the highest one (ponte s. mauro) by a third lake whose dam could be sited in an area known as parata, where the author could observe recent lacustrine deposits. quilici (1996) sums up and subjects to a rigorous examination the works of the numerous preceding authors about the occurrence and the localization of the three roman dams, which ruins he describes in detail. they are still visible in the three above-mentioned sites along the river. he has no doubt on the occurrence of the highest and most spectacular dam at ponte s. mauro, where the river flows through a gorge between 6 to 20 m large and at least 50 m high; the lake level could have been placed at about 450 m. a second dam, from 10 to not more than 20 m high, 38 c. carrara et al. could have occurred at parata, forming a lower lake reaching the base of the s. mauro dam. on the contrary he doubts of the existence of the ponte rapone dam; according to him the ponte rapone hillock overlooked the lower lake. finally, the dam at cartiera di subiaco, near the ponte s. antonio, is not to be considered of roman age, but it is dated to the xv century. almost all the authors agree that in 1305 a catastrophic flood caused the collapse of the highest dam, the emptying of the relative lake and heavy damage downstream along the valley. from archeological research, therefore, it can be inferred that in the subiaco area the lakes, still active until 1305, were two (presumably three). they were substained by artificial dams or bridge-dams localised as follows: near the present ponte s. mauro, the highest and more extended lake with a surface at an altitude of 460 (fig. 18), near parata a supposed middle lake with a surface at 440-450 m and at cartiera di subiaco near ponte s. antonio, the third one, dated to the xv century (quilici, 1996) at 400 m. on the basis of data coming from the archeological ruins, described by archeologists, and of the results of morphological and geological detailed research, carried out in this research in the tract of aniene river between the mentioned bridges, it is worth noting that near ponte s. mauro and in the parata locality the ruins, related to roman dams, also observed by carosi (1956), orlandi (1984-1988, 2002) and quilici (1996), are still visible. actually, on the left side of the ponte s. mauro, wall ruins of great thickness (some metres) occur. they are linked to the northern vertical scarp of the ist order terrace, in which the cava segatori has been cut. the quarry, on the other hand, has been excavated for a long time and it cannot be excluded that it was used for the extraction of calcareous tufa materials for the construction of the dam. on the right side of the bridge, under cappella di s. mauro, the same walls were connected to the vertical scarp of the ist order terrace that also shows signs of quarrying. moreover, ruins of the dam have been observed by archeologists on the river bed under the bridge. it is worthy noting that along the aniene valley, upstream of subiaco, well preserved terraces, whose surfaces are at about 460-465 m, occur. the most developed one (fig. 19) extends some hundreds of metres and shows a scarp up to 10 m on the riverbed, where a section composed of fluvio-lacustrine, yellowreddish, fine-grained sands and silts, containing in the upper part brown, organic layers, can be observed. damiani et al. (1998) have already assumed that these terraces could be referred to the highest neronian lake. during the present research from the above-mentioned organic layers several samples for 14c dating have been collected, but until now results are not available. also at the locality of parata, where, according to several archeologists the second dam occurred, on the left side of the river, another thick, heavily dismantled wall can be observed. it is linked to the vertical tufa scarp of the iind order terrace body, here 30-40 m high. on the river bed, here flowing in a gorge not larger than some tens of metres, remains of a great ancient walls, related to roman age, under the gravel cement bulkheads built in more recent times, crops out (fig. 20). as regards the dam at ponte s. antonio, presumably built up in xv century to raise the river waters in order to feed the cartiera di subiaco, at present no ruins occur. probably this dam joined the river banks at the same elevation of the iiird order terrace surface. the morphological and geological features of the areas where the three dams were built up (fig. 21) and the information obtained from archeological data demonstrate that the three depositional calcareous tufa 39calcareous tufa deposits ... fig. 18 reconstruction of neronian villa and dam at ponte s. mauro at subiaco by l. canina (from orlandi, 2002). ricostruzione della villa e della diga di nerone al ponte di s. mauro a subiaco di l. canina (da m. orlandi, 2002). terraces previously described were fundamental in choosing the dam sites. infact, they were localized where the thick, vertical scarps of calcareos tufa terraces formed very narrow gorges. the sites, therefore, were most favourable for the construction of such works. hence, it can be inferred, if there is still need, that in the studied area the deposition of calcareous tufas and the formation of the relative terraces, in spite of the following erosion and remodelling phases, has considerably modified the former geomorfic framework of the valley and has been decisive in conditioning the human activity and its works. 9. conclusions in the aniene valley several calcareous tufa deposits occur; some of them are still active and are connected to mainly carbonate-calcic cool springs, linked to karstic paths of the simbruini-ernici and lucretili mounts. the marano equo, subiaco and mandelavicovaro deposits have been studied in greater detail. the first one, 15 m thick, has been found underground in a borehole that crossed alluvial sediments related to the paleo-aniene river, at a depth comprised of between –50 and –64 m. the subiaco deposit, about 70 metres thick, is composed of three depositional terraces, the formation of which alternated with extensive erosional phases. its lithofacies associations indicate that the deposition evolved from a palustrine to a higher energy, fluvio-lacustrine environment, due to fluvial barrage of a calcareous tufa system grown in correspondence to a morphological step of tectonic origin. the mandela-vicovaro deposit also, forming a wide terrace with a thickness of 60-70 m, extending about 3 km along the aniene valley, evolved from a palustrine to a fluvio-lacustrine environment. it was developed because of a fluvial barrage grown in the vicovaro area, where the emplacement of middle pleistocene volcanics covered by more recent alluvial sediments, caused the formation of a morphological high. the malacological content of calcareous sands and silts occurring in the upper part of the deposit indicates the presence of a depositional environment characterized by highly vegetated small shallow lakes, pools and ponds in a temperate climate. u/th datings of marano equo, subiaco and mandela-vicovaro deposits suggest the attribution of the first deposit to upper pleistocene, while the second and the third are related to upper pleistocene-lower holocene and lateglacial-middle holocene ages. the deposition of calcareous tufas in the studied area has been active in spans of time characterized by opposing climatic variations: not only during warm and wet stages (interglacials or interstadials), but also during fresher, temperate and wet stages, as proved by the malacological content of sandy-silty sediments and by datings. it is therefore probable that, at our mid latitudes and altitudes, the calcium carbonate precipitation from fresh waters is more influenced by the “degree of humidity” of that moment in that area, than by variations of temperature and that the deposition of calcareous tufas stops during the cool and /or warm but dry intervals, while it undergoes a decrease or an increase during the intermediate ones. on the basis of detailed bibliographic and field archeological and geological reserches, some considerations about the occurrence of artificial dams built up by nero in the subiaco area, which dammed the aniene river and caused upstream the formation of extended lakes, whose hypothetical reconstruction is drawn in fig. 18, have been discussed. at least two dams, at ponte s. mauro and at parata, have been built during nero’s reign; they were destroyed by a cathastrophic flood in 1305. a third dam, built near the cartiera di subiaco, can be attributed to the xv century. in the studied area the deposition of calcareous tufas and the formation of the relative terraces, in spite 40 c. carrara et al. fig. 19 lacustrine terrace occurring about 3,3 km upstream of subiaco, probably related to the neronian dam at ponte s. mauro and the relative lake, ruined in 1305 because of an alluvial flood. terrazzo lacustre affiorante a monte di subiaco, probabilmente connesso con la diga neroniana di ponte s. mauro e il relativo lago, distrutta nel 1305 da un’alluvione. fig. 20 ruins of a roman wall, occurring under more recent cement dam in the locality of parata, probably related to the neronian parata dam. resti del muro romano affioranti sotto una diga in cemento più recente, probabilmente connesso con la diga neroniana di parata. of the following erosion and remodelling phases, has considerably modified the former geomorphic framework of the valley and has been decisive in conditioning the human activity and its works. aknowledgements: the authors want to thank don romano of s. scolastica monastery for the help given in the bibliographic research. references bally a.w., burbi, l., cooper, c., ghelardoni, r. (1986) balanced sections and seismic reflections profiles across the central apennines. mem. soc. geol.. it., 35, 257-310. beneo e. (1934, anno xii) alcune osservazioni geologiche sulla regione sublacense. boll. r. com. geol., lix, 7, 2-16. 41calcareous tufa deposits ... fig. 21 hypothetical reconstruction of the lakes in the subiaco area, formed by the neronian dams at ponte s. mauro (1) and parata (2) and by the dam of xv century at cartiera di subiaco (3). ricostruzione ipotetica dei laghi presenti nell’area di subiaco, dovuti alle due dighe neroniane di ponte s. mauro (1) e parata (2) e a quella del xv secolo della cartiera di subiaco (3). beneo e. (1943) note illustrative alla carta geologica d’italia alla scala 1:100.000, f° 151 alatri. bieler chatelain t. (1929) lo sbocco a contropendio del torrente licenza nel fiume aniene. boll. soc. geol. it., 48, 59-62. boni c. f., bono p. & capelli g. (1988 a) carta idrogeologica del territorio della regione lazio. univ. degli studi di roma “la sapienza”. boni c. f., bono p. & capelli g. (1988 b) schema idrogeologico dell’italia centrale. mem. soc. geol. it., 35, roma (1986). branca m., calderoni g., cavarretta g., cosentino d., esu d., gliozzi e., parotto m. & piccardi e. (1995) pleistocene through holocene evolution of the intrappenninic basin of marano equo (latium, central italy): preliminary results of a multidisciplinary study on sediment cores. abstr. xiv intern. inqua congr., berlino 3-10 agosto, 1995, 54, berlin. brancaccio l., d’argenio b., ferreri v., stanzione d., taddeucci a. e voltaggio m. (1992) i travertini di rocchetta al volturno (molise). datazioni con il 230th e modello deposizionale. atti del 74° congr. soc. geol. it. sorrento, 13-17 sett 1988, pp. a63a67. brondi f. (1995-96) la sorgente carsica dell’inferniglio. acquisizione ed elaborazione dati anno 1994. tesi di laurea, università degli studi di roma “la sapienza”. buccino g., d’argenio b., ferreri v., brancaccio l., ferreri m., panichi c. & stanzione d. (1978) i travertini della bassa valle del tanagro (campania): studio geomorfologico, sedimentologico e geochimico. boll. soc. geol. it., 97, 617646. capezzuoli e. & gandin a. (2004) i “travertini” in italia: proposta di una nuova nomenclatura basata sui caratteri genetici. il quaternario, 17(2/1), 273-284. carosi p. (1956) il primo monastero benedettino. in: studia anselmiana, 39, 1-188, roma. carrara c. (1991) travertine deposits of the middle liri valley (central italy): geomorphological, sedimentological and geochemical study. palaeoenvironmental and palaeoclimatic implications. il quaternario, 4(1a), 55-84. carrarra c. (2002) aspetti genetici del travertino. in: giardini m. (a cura di): atti del convegno sul tema “il travertino: aspetti naturalistici e sfruttamento industriale all’inizio del terzo millennio”, guidonia, 27-28 ottobre 2000, 21-32. carrara c. (1994) i travertini di canino (viterbo, italia centrale): elementi di cronolitostraitigrafia, di geochimica isotopica e loro significato ambientale e climatico. ii quaternario, 7(1), 73-90. carrara c. (1998) i travertini della valle del pescara tra popoli e tor de' passeri (abruzzo, italia centrale). il quaternario, 11(2), 163-178. carrara c., esu d. & ferreli l. (1995) lo sbarramento di travertino delle marmore (bacino di rieti, italia centrale): aspetti geomorfologici, faunistici ed ambientali. il quaternario, 8(1), 111-118. carrara c., ciuffarella l. & paganin g. (1998) inquadramento geomorfologico e climatico ambientale dei travertini di rapolano terme (si). il quaternario, 11(2), 319-329. castagnolo l., franchini d. & giusti f. (1980) bivalvi: guide per il riconoscimento delle specie animali delle acque interne italiane, 10. consiglio nazionale delle ricerche, collana del progetto finalizzato “promozione della qualità dell’ambiente”, aq/1/49:1-63. cavinato g.p., corrado, s., sirna, m. (1992) dati preliminari sull’assetto geologico strutturale del settore sud-occidentale della struttura simbruino-ernica. studi geologici camerti, volume speciale (1991/1992), crop 11, 33-42. damiani a. v. (1990a, b) studi sulla piattaforma carbonatica laziale-abruzzese. nota i. b considerazioni e problematiche sull’assetto tettonico e sulla paleogeologia dei monti simbruini. mem. descr. carta geol. d’ it., 38, 145-176. damiani a.v. (1992) riflessioni sull’assetto tettonico della dorsale dei monti simbruini affilani “preernici” ernici e nuove ipotesi di lavoro. studi geologici camerti, vol. spec. (1991/1992), crop 11, 63-66. damiani a. v. & pannuzi l. (1981) foglio “376” subiaco di geomorfologia dinamica alla scala 1:50.000 e relative note illustrative. servizio geologico d’italia, 35 pp. damiani a. v., catenacci v., molinari v., panseri c. & tilia a. (1998) servizio geologico d’italia carta geologica d’italia alla scala 1:50.000, f° 376 subiaco e relative note illustrative, 1-55. d’argenio b. & ferreri v. (1986) a brief outline of sedimentary models for pleistocene travertine accumulation in southern italy. rend. soc. geol. it., 9, 167-170. de angelis d’ossat g. (1897) l’alta valle dell’aniene. i: orografia ed idrografia esterna. mem. soc. geogr., 7, 191-266. de angelis d’ossat g. (1897) l’alta valle dell’aniene. ii:contributo allo studio paleontologico. mem.soc. geogr., 16, 280-318. de angelis d’ossat g. (1924) l’elephas antiquus falk. presso subiaco. boll. soc. geol. it., 43, xli-xiv. devoto g. (1967) note geologiche sul settore centrale dei monti simbruini ed ernici (lazio nord-orientale). boll. soc. natur. napoli, 76, p. ii, 487-596. ehrmann p. (1956) mollusca. in: brohmer p., ehrmann p. & ulmer g., die tierwelt mitteleuropas. 2 (1), 1264, verlag quelle meyer. esu d. (1978) la malacofauna continentale pliopleistocenica della formazione fluvio lacustre di naraghe-su-casteddu e sue implicazioni paleogeografiche. geologica romana, 17, 1-33. faccenna c., funiciello r., montone p., parotto m.& m. voltaggio (1994). late pleistocene strikeslip tectonics in the acque albule basin (tivoli, latium). mem. descr. carta geolog. d’italia, 69, 37-50. farabollini p., materazzi m., miccadei e. & piacentini t. (1994) i travertini dell’italia centrale: genesi, cronologia, significato geomorfologico e paleoambientale. il quaternario, 17 (2/1), 259-272. festuccia s. & zabotti f. (1992) il popolamento della media valle dell’aniene in età pre protostorica. atti e mem. soc. tibur. storia e arte, 65, 129-156. fiore cavaliere m.g. & mari z. (1996) evidenze di un probabile terremoto medievale nella villa di 42 c. carrara et al. nerone a subiaco. atti e memorie della società tiburtina di storia e arte, 69, 10-17. frontinus, de aquaeductu urbis romae commentarius. xciii. funiciello r., mattei m. & voltaggio m. (1992) recent strike slip faulting and problems of possible reactivation in rome area. in: eartquake prediction, edited by e.boschi & m. dragoni, il cigno galileo galilei, 225-236. gascoyne m., schwarcz h. p. & ford d. c. (1978) uranium series dating and stable isotopic studies of speleothems. part i: theory and tecniques. proc. british cave res. assoc., 5, 91-111. r. s. harmon (eds.), uranium series disequilibrium: application to environment problems in the earth sciences. university press of oxford, oxford, 268-301. girod a., bianchi i. & mariani m. (1980) gasteropodi 1: guide per il riconoscimento delle specie animali delle acque interne ital iane, 7 . consiglio nazionale delle ricerche, collana del progetto finalizzato “ promozione della qualità dell’ambiente”, aq/1/44:1-85. giusti f., castagnolo l. & manganelli g. (1985) la fauna malacologica delle faggete italiane: brevi cenni di ecologia, elenco delle specie e chiavi per il riconoscimento del genere e delle entità più comuni. bollettino malacologico della società italiana di malacologia, 5-6, 69-144. golubic s., violante c., ferreri f. & d’argenio b. (1993) algal control and early diagenesis in quaternary travertine formation (rocchetta a volturno, central apennines). boll. soc. paleont. it., spec. vol. 1, mucchi, modena, 231-247. gordon d., smart p., ford d., andrews jn., atkinson t., rowe p., christopher n. (1989) dating of late pleistocene interglacial and interstadial periods in the united kingdom from speleothem growth frequency. quaternary research, 31, 1426. kano a., kawai t., matsuoka j. and ihara t.(2004) high-resolution records of rainfall events from clay bands in tufa. geol.soc. of america, 32(9),793796. kerney m. p. & cameron r. a. d. (1979) a field guide to the land snails of the britain and north-west europe. collins ed.: 7-288. ku t. l. & liang z. c. (1985) the dating of impure carbonates with decay-series isotopes. nuclear instruments and methods in physics research, 223, 563-571. ložek v. (1964) quartärmollusken der tschechoslowakei. rozpravy ústedniho ústavu geologichého, 31, 7-374, praga. minissale a., kerrick d. m., magro g., murrell m. t., paladini m., rihs s., sturchio n. c., tassi f. & vaselli o. (2002) geochemistry of quaternary travertines in the region north of rome (italy): structural, hydrologic and paleoclimatic implications. earth and plan. sc. letters, 203, 709-728. molin d., rossi a., tertulliani a., verrubbi v. (2002) studio della sismicità dell’alto bacino dell’aniene (appennino centrale – italia) e catalogo sismico dell’area. ingv, quaderni di geofisica, 24, 1-80. orlandi m. (1984-1988) la villa di nerone a subiaco. il sacro speco, 1984, 3, 87-89; 1985, 2, 57-61; 3, 92-94; 4/5, 132-137; 6, 175-177; 1986, 1, 24-27; 1987, 2, 59-62; 3, 86-91; 3, 149-153; 5, 149-153; 6, 57-60; 6, 183-186; 1988, 3, 91-94. orlandi m. (2002) i monasteri benedettini nella valle dell’aniene. in: xv centenario della venuta di s. benedetto a subiaco. celebrazioni benedettine 1999-2001, acta. parte prima, convegno archeologico, subiaco 2002, 13-38 e 45-54. orombelli g. & ravazzi c. (1996) the late glacial and early holocene: chronology and paleoclimate. il quaternario, 9(2), 439-444. pazdur a., dobrowolski r., durakievic t., mohanti m., piotrowska n., das s. (2002) radiocarbon time scale for deposition of holocene calcareous tufa from poland and india (orissa). geochronometria, 21, 85-96. pedley h. m. (1990) classification and environmental models of cool freshwater tufas. sedim. geol., 68, 143-154. pedley h. m. (2000) ambient temperature freshwater microbiala tufas. r. e. riding and s. m. awramik (eds.), microbial sediments, springer-verlag, berlin, heidelberg, 179-185. pedley m., gonzáles martín j. a., ordóñez delgado s. & ángeles garcía del cura m. (2003) sedimentology of quaternary perched springline and paludal tufas: criteria for recognition, with examples from guadalajara province, spain. sedim., 50, 23-44. pellati n. (1882, anno xiii) i travertini della campagna romana. boll. r. com. geol. d’it., xiii, 196-221. percopo c. (1992) idrogeologia del bacino rappresentativo alto aniene (subiaco). acquisizione dati anno 1991. tesi di laurea, dipartimento scienze della terra, università degli studi di roma “la sapienza”. pliny the elder, naturalis historia, iii, 12. ponzi g. (1852) sopra un nuovo cono vulcanico rinvenuto nella val di cona. atti acc. pontif. nuovi lincei, t. v, a. v, 1851-52, 263-267. ponzi g. (1862) dell’aniene e dei suoi relitti. atti acc. pont. dei nuovi lincei, 15, 1-6. ponzi g. (1878) le ossa fossili subappenninichedei dintorni di roma. atti acc. pont. nuovi lincei, 2, 709 pp. quilici l. (1996) i simbruina stagna di nerone nell’alta valle dell’aniene. in: uomo acqua e paesaggio, atti dell’incontro di studio sul tema “irreggimentazione delle acque e trasformazione del paesaggio antico”, s. maria capua vetere, 22-23 novembre 1996, l’erma di bretschneider. ravazzi c. (2003) an overview of the quaternary continental stratigraphic units based on biological and climatic events in italy. il quaternario, 16(1bis), 1118. salvini f., & storti f. (1992) vincoli per la preparazione di un profilo geologico bilanciato: la sezione ponte lucidi (subiaco) poggitello (tagliacozzo), appennino centrale. studi geologici camerti, volume speciale (1991/1992), crop 11, 95-101. settepassi f. & verdel u. (1965) continental quaternary mollusca of lower liri valley (southern latium). geologica romana, 4, 369-452, roma. tacitus, annales, xiv, 22. 43calcareous tufa deposits ... taddeucci a. and voltaggio m. (1987) th-230 dating of the travertines connected to the vulsini mts. volcanism (northern latium, italy) : neotectonics and hydrogeology. periodico di mineralogia, 56, 295-302. taddeucci a., tuccimei p. , voltaggio m. (1992) studio geocronologico del complesso carsico “grotta del fiume grotta grande del vento “ (gola di frasassi, ancona) e implicazioni paleoambientali. il quaternario, 5(2), 213-222. ventriglia u. (1990) idrogeologia della provincia di roma “regione orientale”. amm. prov. di roma, assessorato ll.pp., viabilità e trasporti, 4, 225228. viola c. (1903) osservazioni geologiche nella valle dell’aniene fatte nel 1902. boll. r. com. geol., xxxiv, 1, 34-47. violante c., ferreri v., d’argenio b. & golubic s. (1994) quaternary travertines at rocchetta a volturno (isernia, central italy). facies analysis and sedimentary model of an organogenic carbonate system. 15th ias regional meeting, april 1994, ischia, italy, excursion a1, 3-23. 44 c. carrara et al. ms. ricevuto il 17 novembre 2005 testo definitivo ricevuto il 21 marzo 2006 ms. received: november 17, 2005 final text received:march 21, 2006 ojs380 peresani et al def corretto potì.pub available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 35 (1), 2022 , 5-29 the middle palaeolithic site of vajo salsone in the monti lessini, italian alps. first report on the archaeofauna and lithic assemblage with foliate tools. marco peresani 1,2, davide delpiano 1, ursula thun hohenstein 1, gianluca arnetta 1, hugues-alexandre blain 3,4, vittoriana espedito 1, juan manuel lópez-garcía 3,4, alessandro potì 1, ugo sauro 5, davide visentin 1,6, giorgio chelidonio 1, davide margaritora 1, yvonne tafelmaier 7 with the collaboration of: lorena beltrame 1, cristina failla 1, federico pellegrini 8, paolo pellegrini 8 1 università di ferrara, dipartimento di studi umanistici, sezione di scienze preistoriche e antropologiche, ferrara, italy. 2 igag cnr, milano, italy. 3 iphes, tarragona, spain. 4 universitat rovira i virgili, departament d'història i història de l'art, tarragona, spain. 5 ethnografic museum, la lessinia, l’uomo e l’ambiente, boscochiesanuova (vr), italy. 6 archaeology of social dynamics group, imf-csic, barcelona, spain. 7 regierungspräsidium stuttgart, landesamt für denkmalpflege, referentin für paläolithikum & mesolithikum, esslingen, germany. 8 via vagiol 44, 37020, fane di negrar, verona, italy. corresponding author: marco peresani <marco.peresani@unife.it> abstract: this first report aims to illustrate the middle palaeolithic site of vajo salsone in the monti lessini plateau in the eastern italian alps, its geological and geomorphological context, the conditions leading to its discovery occurred after a road cutting, and the archaeological excavation of a karst structure where the sediments, faunal and cultural remains were still preserved. the karst infill is a massive clast-supported breccia with abundant animal bones and lithic artifacts coated of carbonate encrustations. the first analysis of the samples of small and large mammal assemblages recovered in the karst deposits has revealed the abundance of microtus arvalis, a rodent currently reported to live in open environments and in relatively drier regions of northern italy. still, mosaic habitats with the presence of stony areas and scattered low scrubs are suggested by the presence of h. viridiflavus among the herpetofauna. amongst the abundant faunal assemblage, the most common represented species are cervus elaphus, capreolus capreolus and rupicapra rupicapra along with few carnivores. at the present state, only red deer bones showed taphonomic evidence ascribable to hunting and exploitation, similarly to other middle palaeolihic sites of the region. the lithic industry consists of a huge number of chert artifacts produced using levallois as the main knapping method together with an ephemeral use of discoid and volumetric blade exploitation. no appreciable difference in the taphonomic layout has been observed between the byand end-products of these technologies. predetermined blanks, cores and numberless of flat, elongated, cortical flakes attest the integrity of the levallois reduction sequences. retouched tools are mostly simple, double, often converging and, occasionally, transverse scrapers, and retouched points. in addition to these typical mousterian tools, the distinguishing feature of vajo salsone is the presence of foliate tools made through invasive bifacial shaping, an already known model in central europe. based on what resulted from our preliminary data, we have provisionally reconstructed the morphogenesis of the site in accordance with the following hypothesis: 1) in the basal part of a wall, inside a large natural niche evolved by weathering and karst processes, groups of neanderthals settled, leading to the deposition of anthropogenic sediments; 2) following phenomena of rockfall and toppling of large blocks, retreat of the wall and dismantling of the large niche occurred, together with the erosion of the sediments of the shelter. these sediments were transported down-valley and partly trapped in a small karst shaft. even though most of the evidence from the vajo salsone lithic assemblage is comparable with the one of other sites in the region and the northern mediterranean area, it does however provide new details about the late pleistocene cultural scenario, thus contributing to enrich the middle palaeolithic picture. keywords: mousterian, foliate tool, fauna, prealps, italy. 1. introduction monti lessini, in the central southern italian prealps (fig. 1), is a mountainous area closely surveyed for the reconstruction of the middle palaeolithic settlement system and neanderthal culture. within the framework of multidisciplinary projects led by the natural history museum of verona, the university of ferrara, the superintendence for archaeological heritage of veneto and local societies, surface prospections and excavations have been carried on from the end of the 19th century, and they are still ongoing (see contributions in aspes, 2003). monti lessini count the highest number of mousterian sites within the north of italy. a considerable bulk of data was obtained from deposits in caves, rock shelters and open air sites, becoming even more significant when compared to other italian mountain ranges (margaritora et al., 2020). however, despite the remarkable information acquired through the study of these sites, our knowledge about the variability of neanderthal https://doi.org/10.26382/amq.2022.01 material culture is still unexpectedly far from being considered exhaustive. a factor of bias is the decreasing of the archaeological record as consequence of destructive post-depositional processes, which affect the degree of preservation and therefore the information value of the finds coming from open-air and stratified sites. stratigraphic deposits preserved in atrial cavities and under rock shelters, indeed act as geological archives, preserving key information about chronology, evolution of natural environments and expressions of human behavior. among the contexts that had been systematically explored, it is worth to mention riparo zampieri, riparo mezzena, the “cave a” of veja, riparo tagliente, grotta della ghiacciaia and grotta di fumane. in particular, the latter is a crucial site for the understanding of the middle and upper palaeolithic transition, bearing the oldest cultural attestations ascribable to anatomically modern humans (peresani, 2012; peresani et al., 2016; broglio et al., 2006). despite the dating of some stratigraphic sequences still need to be confirmed, according to the material culture found at these sites it appeared that human groups settled in the area roughly during the late pleistocene. older lithic assemblages are represented by thick flakes sometimes retouched or by levallois industries, both associated with some bifaces. still, the quinzano quarries remain the most important site, also because of the recovery of faunal remains of deer, elephant, fallow deer, and roe deer (zorzi & pasa, 1944-45). in north-eastern italy, it is commonly assumed that the levallois technology, with its recurrent unidirectional and centripetal modalities, dominates the lithic industries of the sites of this region and of monti lessini as well (peresani, 2001, 2011). flexibility in flake-making resulting from the application of these different recurrent modalities has been observed both at open-air and at multilayered sites. technological similarities amongst the lithic industries have been recognized within the tool -sets, mostly composed of side, transverse, converging scrapers, retouched points, and, to a much lesser extent, of denticulates. conversely, none of these assemblages specifically aimed at a levallois points production. yet, a core volumetric concept related to the quina sphere was undoubtedly identified at two sites (peresani, 2012; jéquier et al., 2015). discoid technology was recorded as well. it becomes more frequent during the marine isotope stage 3 and participates to a more complex cultural phenomena which highlights an fig.1 north-eastern italy showing the geographical location of vajo salsone and of the middle palaeolithic sites mentioned in the text: 1) vajo salsone; 2) fumane cave; 3) ghiacciaia cave; 4) tagliente rockshelter; 5-6) broion cave, broion rockshelter; 7-8) san bernardino cave, paina cave; 9) de nadale cave; 10) podere due pozzi; 11-13) palazzone-ca roma, peverella, ca’ san carlo; 14) brusaida; 15) ghiardo; 16) monte netto. coordinate system etrs89 / utm zone 32n (epsg 25832); digital elevation model (base topography – copernicus land monitoring service (clms), 2019 and general bathymetric chart of the oceans (gebco), 2019; rivers and lakes (http://www.sinanet.isprambiente.it/it/sia-ispra/download-mais/reticolo-idrografico). 6 peresani m. et al. increase in the variability at the end of the middle palaeolithic (peresani, 2011). discoid industries are typically represented by a range of flakes and pseudolevallois points, scrapers, points and denticulates, and purposedly modified backed tools (delpiano et al., 2019a). with the aim of shedding new light on the neanderthal cultural variability of this area, the following paper presents the recently discovered (2017) site of vajo del salsone (vajo salsone). its archaeological content is represented by a huge amount of lithic artefacts and faunal bones contained in a karst pit developed in oolitic limestones and opened during new road cutting. the cultural value of this site is supported by the unexpected finding of several leaf points which add a touch of originality in the middle palaeolithic of this part of mediterranean europe. 2. presentation of the vajo salsone site 2.1. the site in the morphostructural setting of the lessini mountains the vajo salsone site is located in the monti lessini, a mountain group belonging to the venetian prealps (fig. 1). the lessini group can be considered a monocline structure with a trapezoidal shape, where its shortest side faces north. it is radially dissected by several valleys developed along tectonic lines, shaping canyons locally called vaj in some sections. the relief is mainly sculptured in the context of a series of carbonate rocks ranging in age between the upper triassic and the eocene. this is the so-called “serie veneta" which includes the following geological formations: calcari grigi, oolite di san vigilio, rosso ammonitico veronese, maiolica, scaglia rossa, eocene limestones, formed in marine environment. volcanic rocks are equally attested in the upper part of the succession (bosellini et al., 1967; carraro et al., 1969). in its medium-high portion, the serie veneta is rich in chert. this one can be found both in primary outcrops as nodules and layered deposits in late jurassic, cretaceous and eocene rocks and in secondary position in superficial deposits, soils and coarse alluvial deposits (bertola, 2016). if the main features of the relief can be explained by the lithological and tectonic characteristics of the different formations, the understanding of the morphostructural building and its evolution requires a summary of the geological history and an analysis of the sort of deposits resulting from the main recent seismic events (sauro, 2003; sauro & zampieri, 2001; sauro & ferrarese 2016). the most significant tectonic events for the history of the morphostructural building began with a relaxing phase, developed during jurassic and cretaceous periods, when the sedimentary rock complex was still covered by the sea. the movements of continental masses generated fractures in the crust, with formation of a submarine rift consisting in a sort of plateau elongated in the n-s direction, corresponding to the current verona-trentino area (called “trento platform”). this plateau was bordered on both sides by a stairway of narrow and elongated blocks, which marked the passage towards the bottom of two basins located on the sides: on the west side the “lombard basin”, and on the east side the “belluno basin” (castellarin, 1981). in this phase, the different depths of the seabed influenced the sedimentation processes, and therefore determined the characteristics and thickness of the formations themselves. the subsequent deformation events were controlled by the fault systems identified in the context of the mesozoic rift. the ancient faults were reactivated due to different geodynamic conditions, mainly of compressive type. in addition, new fault systems were originated, such as the schio-vicenza system (zampieri, 1995, 2000). this evolution is explained by the collision of the african craton against the eurasian one, which, in the mediterranean, resulted in the formation of the alps. the directions of maximum tectonic compression have changed over time, rotating counterclockwise, from n 55° direction (between 50 and 35 million years ago), followed by n 25° directions (between 30 and 16 million years), n 340° (between 16 and 6 million years), and n 310° (between 6 and 2 million years) (castellarin et al., 2006). nowadays, compressive mechanisms are still active, as shown by recent earthquakes such as the friulian one in 1976, or the historical 1117 verona earthquake, which turns out to be the most famous historical seismic event in the alps (guidoboni et al., 1985, 2005; galadini et al., 2001; sauro & zampieri 2001; sauro, 2003; poli et al., 2008; viganò et al., 2008; sauro & ferrarese, 2016; mantovani et al., 2021). the prevailing compression from south to north is due to the advancement of the apennine front, buried under the alluvial sediments of the po river. yet, at the same time, the brescia pre-alps, being hindered in their movement to the north by the adamello batholith, divert their thrust to the east, investing the monte baldo group and the lessini mountains. therefore, the compressive forces are exerted both in n-s and in e-w direction due to the anisotropy of the structural building. the result is a progressive fragmentation of the n-s elongated blocks and their deformation, together with vertical shifting and western tilting (massironi et al., 2009; sauro & ferrarese, 2016). tectonic activity and its related fault systems (zampieri, 2000) exert strong influence on erosional phenomena, represented by weathering, karst, and different classes of slope processes which led to the development of the present-day landscape. karst is one of the most impacting process and together with hydrological activity gives rise to different styles of physical landscape also controlled by the lithological features of the geological formations. these features can be identified through the hydrographic network and from a series of different superficial and underground morphologies, resulted by the numerous faults and fractures that accelerate and facilitate the water flowing through rocks. according to the tectonic evolution and to the main mopho-dynamic processes, the pattern of the presentday landscape may be defined as both fluviokarstic and tectokarstic (sauro, 1973; mietto and sauro, 2000). in the valpantena area these movements can be easily detected: surface faulting walls with displace foliate tools from a middle palaeolithic site in italy 7 ments that locally exceed two meters, folds created at the edges of the blocks, covers of debris and breccias on the slope that can be interpreted as seismites (zanferrari et al., 1982; sauro & zampieri, 2001; sauro & ferrarese, 2016). the vajo salsone is located right besides an e-w fault that separates two of the blocks constituting the n-s ridge between valpolicella and valpantena. this explains the intense fracturing activity in proximity of the fault. during the quaternary, the monti lessini were partly covered by the adige glacier or by local glaciers attested on the upper part of the plateau and in the nearby carega massif (sauro, 1973, 2020). periglacial conditions activated strong erosion of the paleosols, accumulations of colluvial deposits in valley bottoms and dolines, especially in the central part of the plateau. from the middle pleistocene onward, the loess sedimentation affected the entire surface of the plateau (magaldi & sauro, 1982; castiglioni et al., 1990). deposits in caves and rock shelters along the slopes allowed to estimate that the deepening of gorges and valleys occurred at least from the late middle pleistocene (castiglioni et al., 1990; cremaschi, 1990). anthropogenic soil erosion during the holocene strongly affected the main slopes, especially starting from the neolithic. 2.2. the valpantena and the vajo salsone the prehistoric site (5046787.37 n, 655509.97 e, 376m a.s.l) is located on the left (northern) slope of vajo salsone, a deep cut in the right slope of the upper valpantena (fig. 2). this latter, a large erosional feature located ne of the town of verona, looks like an inlet of the high venetian plain within the pre-alpine relief, including a large alluvial plain that mostly originated during the middle and late pleistocene from the depositional activity of the adige river and its monti lessini tributaries (de zanche et al., 1977). valpantena begins at the confluence of three canyon like valleys: vajo della marciora, vajo dei falconi and vajo dell’anguilla. regarding the tectonic system, the afore-mentioned three fluviokarstic canyons together with valpantena as their continuation, are set along a bundle of fault lines oriented nnw-sse and nne-ssw. the right (western) slopes of these valleys are mainly in-facing slopes, while the left (eastern) ones are predominantly dipslopes (sauro, 1978, 2013). this explains the asymmetry of the valley slopes and the presence of high walls only on the right slopes. the profile of the main valley western slope surrounding the archaeological site is characterized, in its lower part, by a strip inclined 30-35°, modelled in the limestone of the lower jurassic (formations of calcari grigi and oolite di san vigilio). the band is delimited upstream by a frame of oolite di san vigilio and rosso ammonitico veronese limestone rock walls. the rosso ammonitico, consisting of micritic limestones more resistant to degradation and erosion than the underlying rocks, acts as a “roof” for the more erodible oolite limestones, thus favouring the conservation of the walls. above these, the profile develops in a large substructural terrace followed upwards by a sequence of slopes shaped in cretaceous limestone formations interbedded with volcanites, up to a sub-structural summit plateau in eocene limestone, which characterizes the ridge between valpantena and valpolicella (monte comun). karst landforms are widely distributed in the whole area either as surface karst (dolines, limestone pavements, natural bridges) and deep karst (caves, shafts, swallowing cavities). south of the confluence of the three valleys, the valley floor, formed by gravelly, sandy and pelitic alluvial and colluvial-detrital deposits at the foot of the steepest slopes, widens from north to south, joining the high venetian plain after 15 km. the thickness of the sedimentary filling increases towards south, to such an extent that the rocky bottom of the middle and lower valpantena is situated below the sea level. this can be explained by the messinian event of “desiccation” of the mediterranean and, therefore, by the over-excavation of the river due to the lowering of the base level (bini et al., 1978). fig. 2 geomorphologic map of valpantena. key: 1 vajo salsone site; 2 alluvional, fluvioglacial, lacustric and palustric deposits; 3 oolite di san vigilio, calcari grigi, encrinite of fanes; 4 rosso ammonico, fonzaso formation; 5 maiolica, soccher limestone; 6 scaglia rossa, scaglia variegata, scaglia cinerea; 7 basaltic vulcanite of euganei; 8 calvene formation, salcedo formation, castelgomerto limestone; 9 streams; 10 scarp � 10 m; 11 scarp n.d.; 12 fault line; 13 flexure scarp; 14 fault line valley; 15 small valleys along fault line; 16 caves. technical note. coordinate system wgs84. digital elevation model (base topography dtm 5m https://idt2.regione.veneto.it/). geological layers from https:// idt2.regione.veneto.it/. scarp from https://idt2.regione.veneto.it/. faults from sauro, 1978. 8 peresani m. et al. 2.3. discovery of the site, rescue excavation and processing of materials the site was found during the construction of a truckable road between stallavena (zona revolto) and coda (fig. 1). on may 1st 2016, two of us (f.p. and p.p.) were walking on the fresh road cut at mid elevation along the eastern slope of comun mount, collecting bones and flint artifacts from the mined brecciated bedrock between the fourth and the fifth harpin turn of the road, at 376 m a.s.l. (fig. 3a and 3b). thanks to this discovery a rescue excavation campaign (excavation code: grz17rfl45) was conducted by two of us (d.v. and a.p.) from may 23rd to june 3rd 2017, led by the archaeological superintendence and the university of ferrara. at first the excavations for the construction of the truckable road revealed covers of diamicton with a thickness of between a few decimeters and about 2 m, poor in matrix, formed by angular fragments of limestone, mostly small in size but including some big blocks. there was little or no cementation. inside the covers there were also soil sediments, both in the form of bodies trapped inside cavities with irregular shapes and mixed with rock clasts. the artificial sections of the deposit allowed to recognize some cavities inside it, in form of small conduits, probably caused by piping processes. the site is a small and narrow karst cavity filled by pleistocene sediments yielding abundant middle paleolithic artefacts and faunal remains. the finds were gathered in a context located two meters below the original ground-level, the vajo slope. during the excavation the reworked upper stratigraphic units (sus 1-2-3) were removed as a whole, whereas the main layer (su 5) fig.3 slope and road between stallavena and coda where the archaeological deposit was found (3a); the study area before any archaeological interventions (3b); detail of the terraced s-e side of the cavity (3c); eastern view of su 5 once recent layers were removed (3d); south-eastern view of us 5. red nails delimitate the square-grid used for the excavation of us 5 (3e); south-western view of a portion of su 5 preserved beside the karst chimney (3f). foliate tools from a middle palaeolithic site in italy 9 fig. 4 general plan of the excavated area with extention of su 5 (drawing by d.v. and a.p.). with its palaeontological and archaeological content was manually excavated through a 50 cm grid system and artificial spits of different depths (fig. 3c, 3d and 3e; fig. 4). due to mines activity, the rock wall was highly unstable. for this reason, it was not possible to entirely investigate the archaeological deposit since part of the cavity extended beside the road cut (fig. 3f). in addition to loose sediment samples, three columns of soil and abundant speleothems samples were collected for micromorphological analyses. sediments were wet sieved through superimposed meshes ranging from 5 to 0.5 mm. lithic artifacts and faunal remains were systematically recovered in situ during the excavation process and after wet sieving the sediments. 2.4. sedimentary context morphology of the karst structure. the site consists in a narrow vertical shaft -a feature locally called “arso”formed by the chemical dissolution and water erosion of a discontinuity in the geological bedrock, where two faults (respectively oriented wnw-ese and ne-sw) meet (fig. 5a). there were no traces of active water erosion. the eastern and southern sides of the cavity are terraced and consistent with the stratification of the bedrock, forming a sort of underground room. due to the explosions and the removal of the reworked material the top of the cavity was taken off, thus showing the central and lowest parts of the underground room. despite this partial loss, it was possible to infer the presence of a second karst system. this latter is sub-horizontal, developing n-s, and it might have contributed to the formation of the aforementioned underground room. on the southern side of the excavation the filling deposits directly expose on the slope. the remaining of the vertical chimney was identified at the nw of the deposit on the side of the road cut (fig. 5b). 10 peresani m. et al. nevertheless, this was not enough to allow to infer the original size and shape of the cavity. once the archaeological layers were removed, it was clear that these last ones occupied only a small portion of the chimney, which deepens far below the excavated area without any filling. sediments, distribution, and composition. below the reworked layers (rim) resulted by the construction works it lays the archaeological deposit. this filling is bounded by the cliff and the slope on its northern and southern sides, respectively. overall, the volume of the deposit spread over a 4x4 m surface, and it was thick more than 2 m (without considering the chimney). during the archaeological excavation six stratigraphic units (su) were identified, including a negative one: su1: reworked layer located in the northern part of the excavation besides the rock wall. it contained faunal remains, lithics and modern glazed pottery. su2: resulted by the digging of an artificial pit (su6) in the southern part of the excavation. the filling was located e or ne of the pit and it was characterized by abundant lithic artefacts, faunal remains and limestone clasts ranging in size from cm to dm. the artificial pit was realized in the framework of the first surveys carried on once the deposit was discovered but before any archaeological intervention. it deepens until su5. su3: present day soil preserved only in the se area of the excavation and laying on slope deposits, lays on su4 and partially on su5. it was cut by construction works which did not affect b and c horizons and its thickness measures about 15-40 cm. it is a loamy sand soil characterized by abundant and heterometric clasts (<30 cm) randomly oriented. the layer is dark brown, homogeneous, friable, with roots, organic matter, lithic artifacts and faunal remains scattered in proximity of the boundary with su 5. su5: loamy sand and clast supported layer, slightly hard, yellowish brown (10yr 6/6 munsell soil color charts®, 2001) with increasing content of clay in the lowest part. it contains monolithologic blocks of the size of decimeters, rare, smoothed blocks, fragmented speleothems, abundant lithic artefacts, and faunal remains showing fresh and not abraded edges. two are the most frequent carbonate deposits: a) fragments of speleothems dispersed in the sediment grading > 30-40 cm; b) withish, polylobed and millimetric spots/stains. the layer covers a 4x4 m surface and its thickness spans from few centimetres to more than two meters in relation to the topography of the karst structure (fig. 6). su4: carbonate bedrock exposed over the whole excavated area. flowstone and fragments. in the deepest part of the karst chimney which contained the archaeological layers it was identified a calcite deposit, 3-4 cm thick. it develops besides the bedrock and it preceded the blockage of the cavity. 3. the faunal bone assemblage 3.1. small vertebrates 3.1.1. materials and methods small vertebrates were identified following the general criteria given by berto (2013) and lópez-garcía (2011) for insectivores and rodents, and szyndlar (1984, 1991) for snakes. the specific attribution of this material is mainly based on the best diagnostic elements, mandible, maxilla and isolate teeth for small mammals, and trunk vertebrae for snakes. fossils from su5 were grouped using the minimum number of individuals (mni) method, by means of which we determined the sample (i.e. from each level) through the counting of the most represented diagnostic elements. in the case of snakes, mni has been approached taking into account size categories. 3.1.2. results although the number of identified specimens (nisp) and the mni of small vertebrates are low in vajo salsone su5, the number of the species represented is relatively high (tab. 1). as a matter of fact, small mammals are represented at least by nine different taxa, one insectivore (sorex sp.) and eight rodent species (arvicola amphibius, dinaromys bogdanovi, clerthrionomys glareolus, microtus arvalis, m. agrestis, m. fig. 5 the karst fissure exposed at the end of the excavation (5a) with portion of su 5 deepening below the rockwall left unexcavated because of the instability of the rock. as shown by the picture 5b, the deposit extends inside the rockwall on the northern side of the excavation. the sediment within the karst chimney only partially fills the latter. foliate tools from a middle palaeolithic site in italy 11 (terricola) multiplex-subterraneus, apodemus (sylvaemus) sp. and glis glis, whereas the herpetofauna is only represented by snakes. green whip snake (hierophis viridiflavus) is probably represented by two individuals, an adult (one cervical vertebra, and 20 trunk vertebrae) and a juvenile (two cervical vertebrae, and nine trunk vertebrae), while a viper (vipera aspis) is documented by two fragmentary trunk vertebrae. the relative abundance of m. arvalis, being the most abundant species and the presence of the balkan vole (d. bogdanovi) indicate a late pleistocene age for this assemblage. on the contrary, the holocene in this area (according to berto et al., 2019) from the bølling-allerød interstadial is characterized by a strong decrease of m. arvalis and the disappearance of d. bogdanovi. from a quantitative point of view, among the small mammals the common vole (m. arvalis) is the most abundant species, representing 39.3% of the total mni. such a high rate of m. arvalis is relatively common in late pleistocene sites of north-eastern italy, as attested during mis 5 of grotta maggiore di san bernardino (lópez-garcía et al., 2017), mis 3 of grotta del broion (colamussi, 2002), and grotta minore di san bernardino (lópez-garcía et al., 2019) in the berici hills, together with mis 3 of fumane cave (lópez-garcía et al., 2015) and mis 2 of riparo tagliente (berto et al., 2018) in lessini mounts. the abundance of m. arvalis is currently reported to be higher in open areas and in relatively drier regions of northern italy (amori et al., 2008). still h. viridiflavus prefers open, mosaic habitats with the presence of stony areas and scattered low scrubs. these conditions allowed both species to find open areas for thermoregulation, optimal shelters and hunting zones. on the other hand, they tend to avoid uniform environments such as extensive forest or large grasslands (scali et al., 2008). nowadays, in the region of vajo salsone, only two vipers are present: vipera aspis and vipera berus (sindaco et al., 2006; sillero et al., 2014). v. aspis occupies a wide variety of environments, however, its thermal requirements oblige it to exploit habitats provided with stony substrate, relatively sunny and south-facing dry soils, and with some vegetation cover. in a similar way, v. berus requires a certain habitat complexity. in southern france and northern fig. 6 stratigraphic sections of su 5 (see figure 4 for position; drawing by d.v. and a.p.). 12 peresani m. et al. italy, it is found in either low lying wetlands (if dry soils are available) or at high altitudes (mallow et al., 2003). among the aforementioned sites which are geographically close to each other, and cautiously taking in account data from vajo salsone su 5 due to the small sample of remains, it resulted that this latter mammal assemblage is similar to fumane cave’s one (lopezgarcía et al., 2015), spanning between 50-35 ka bp (peresani et al., 2008; higham et al., 2009). 3.2. large vertebrates 3.2.1. materials and methods our analysis concerned a sample of bone assemblage coming from the upper part of su 5 (spits i, ii and iii). overall, 26,360 faunal remains were examined for this study. the analyzed sample consists of unidentified bone elements and shows a high degree of fragmentation on 85.9% of the finds (22,631) smaller than 2 cm, while only 3,729 remains are longer than 2 cm. considering a total sample of 3.729 tnr selected both for archaeozoological and taphonomic analyses, only 89.8% was scrutinized because 10.2% of the remains (380) is covered by concretions (tab. 2). taxonomic identifications were carried on with the help of reference collections of the laboratory of archaeozoology and taphonomy (lat) and of the large vertebrates of the department of humanities, university of ferrara. anatomy atlases (schmidt, 1972; barone, 1980; pales & lambert, 1971; pales & garcia, 1981) were employed for skeletal and anatomical nomenclature. unidentified remains have been classified according to bone morphology (long, flat, and articular/compact bones), as well as animal groups by weight. we quantified the identified elements using the following indices: nr (number of remains); nisp (grayson, 1984); mne (minimum number of elements) it has been counted considering side, body size and ontogeny (klein & cruz-uribe, 1984); mni (klein & cruz -uribe, 1984; grayson, 1984; lyman, 1994) and mau (minimum animal units) (binford, 1984). fragmentation indexes (mne/nisp) and skeletal survival rate, obtained by comparing the minimum number of elements (mne) with the number of elements expected (ene) on the basis of the mni, were calculated to estimate the skeletal representation of the most represented taxa (binford, 1981; brain, 1981; lyman, 1994). we assessed age at death mainly through the state of ossification of the long bones and the study of deciduos and permanent isolated teeth, although in some instances teeth eruption degree, dental wear, and the stage of epiphysis fusion on long bones were used as well (habermehl, 1961; mariezkurrena, 1983). in order to distinguish the edaphic and anthropic modifications, we scrutinized all the selected specimens at both macroscopic and microscopic level. when necessary, microscopic analyses of bone surfaces were carried out using a leica s6d greenough stereomicroscope with 0.75-70x magnification range, also employed for capturing images. we distinguished taphonomic modifications according to the criteria established by behrensmeyer (1978), binford (1981), lyman (1994), fernández-jalvo & andrews (2016). we classified carnivore marks as follows: pits, scores, punctures, furrowing, gnawing and corrosion by gastric acid (fisher, 1995; domínguez-rodrigo & piqueras, 2003). burnt modifications were recorded too (bennett, 1999). trampling marks were distinguished from butchering tab. 1 representation of the number of identified specimens (nisp), minimum number of individuals (mni) and percentage of mni (%) for small vertebrates of vajo salsone us 5 archaeofauna assemblage. tab. 2 composition of a sample of vajo salsone us 5 archaeofauna assemblage with number of identified specimens (nisp), minimum number of individuals (mni) and minimum animal units (mau). minimal number of elements (mne) is referred to the most represented element useful to estimate both the mni and mau, except for red deer for which mni has been estimated on teeth and mau on astragalus (see table 3). foliate tools from a middle palaeolithic site in italy 13 marks using the works of blasco et al. (2008) and domínguez-rodrigo et al. (2009). evidence of anthropic modification observed on faunal remains include butchery marks (binford, 1981; potts & shipman, 1981; shipman, 1981; galán et al., 2009) and bone retouchers (mallye et al., 2012). 3.2.2. results: composition and taphonomy among the 3,729 selected remains longer than 2 cm, a taxonomic determination was only possible for 1,097 remains representing 29.4% of the sample (tab. 2). isolated teeth and phalanges predominate among the identified elements, followed by tarsal bones, metatarsals and metapodials. however, other skeletal elements belonging to both the axial and appendicular skeletons are present although very fragmented. the faunal composition (tab. 2) consists almost entirely of mammals and for a small percentage of birds, tab. 3 skeletal elements of cervus elaphus with estimation of minimum animal unit (mau), fragmentation index (mne/nisp) and skeletal survival rate (mne/ene-expected number of elements) of a sample of vajo salsone us 5 archaeofauna assemblage. the highlighted values are referred to the elements utilised for estimating mni and mne-mau of red deer for table 2. (grey and light grey respectively). 14 peresani m. et al. at the moment not yet identified at the species level. on the basis of nisp and mni, the most represented species among ungulates is red deer (cervus elaphus) with 62.0%. roe deer (capreolus capreolus) and chamois (rupicapra rupicapra) are rare: 0.5% and 0.4% respectively. the presence of elk (alces alces) is attested by only two remains (0.2%). among carnivores, wolf (canis lupus) prevails with 6.9%, while red fox (vulpes vulpes) reaches only 1.3%. several remains were classified as caprinae, cervidae, large cervidae, canidae in cases when it was not possible to identify them at species or genus level because of the lack of diagnostic morphological elements and the high degree of fragmentation. considering the age at death, estimated on the basis of the degree of dental eruption and wear, and on the state of ossification of long bones, most taxa belong to adults, while some young and sub-adults individuals have been recognized only for red deer. the estimation of minimum animal unit (mau) vs the mni suggests that more than a half of red deer carcasses were introduced complete into the site (tab. 2) and at least half carcasses for the other ungulates. however, only for cervus elaphus it is possible to propose some preliminary considerations about their exploitation and fragmentation of anatomical elements. red deer is represented by 18 individuals: distributed over 4 juvenile/ sub-adults and 14 adults, based on the presence of lower deciduous (dp4) and permanent isolated lower teeth (m3). with regard to the distribution of anatomical elements there are both parts of the axial skeleton and skull with high percentage of teeth (30.6%), and parts of the appendicular skeleton with prevalence of phalanges (14.7%) and tarsals (12%), followed by carpals (7.8%), tibia (5.3%) and metatarsals (4.6%) (tab. 3). estimation of the skeletal survival index (mne/ene) shows that the more represented anatomical elements are astragals (0.78). the other elements belonging to appendicular skeleton are instead poorly represented, showing greater fragmentation (mne/ nisp) of hind limb than forelimb bones. this could indicate a possible selection in the hunting area of elements introduced into the site. the marked representation of teeth, upper (0.58) and lower (0.53), could suggest a transport to the site not only of appendicular parts, but also of complete carcasses in agreement with the results of the comparison between mau and mni (tab. 3). 3.2.3. results: taphonomy all bones and teeth have the same preservation characteristics and uniform surface features pointing for a common sedimentary context and exclude any type of evidence ascribable to mixing with material of holocene or very recent origin. the faunal remains are in a good state of preservation, their color is very homogenous and ranges from whitish to light yellow (10yr8/6 munsell soil color charts®, 2001), with presence of scattered manganese oxides. 27% of the remains (nr 329) is completely covered by concretions that are present on the lithic assemblage too and did not allow to observe the bone surfaces. weathering is light although the remains present post-depositional fractures. of the whole ensemble of taphonomic traces, those ascribable to carnivore actions are rare, identified on only 0.08% of the sample and classified primarily as scores and scarce presence of digested bones. rodent marks were found on a small percentage as well (0.29%), mainly on lateral phalanges and tarsals. traces of anthropic modifications have been observed in higher number than those of carnivores and rodents (tab. 4). the remains bearing butchering marks are 1.7% of the sample and were recognized on bones of medium and large sized cervids: 17 remains belong to red deer, and one to elk. considering red deer’s anatomical elements, traces of butchery are mostly present on segments of the appendicular skeleton, exploited not only for the removal of the meat but also for the consumption of marrow. still, the attested cut-marks suggest skinning and disarticulation (fig. 7) operations, identified respectively on the tarsals and at the level of the articular heads of the long bones, and those relative to defleshing activites localized on the diaphyseal surface of the metapodials. impacts on long bones fragments aimed to collect marrow were also recognized. some thick fragments of long bones like the metapodials bear notches testifying the use of bones as retoucher of stone artifacts. burning traces were found primarily on remains smaller than 2 cm, while only 1.05% of the selected sample showed color changes due to exposure to heating; these included a tooth fragment, a phalanx of roe deer, two diaphyseal fragments of metapodial and a tarsus of red deer. 4. lithic industry 4.1. materials and methods the lithic industry consists of a huge number of chert artifacts picked up as single items during the excavation and after screening of wet sieved sediment. all artifacts are affected by extensive and deep whitish opaque patinae regardless the texture of the chert. nevertheless, the sandy textured chert artifacts of the jurassic san vigilio group were so intensively weathered that ended up disaggregating. however, we did not observe the presence of either the yellowish to dark reddish or bright alteration and patinae which usually affect the paleolithic artifacts contained in clayey paltab. 4 percentage distribution of the different typologies of bone surface modifications in a sample of vajo salsone us 5 archaeofauna assemblage. foliate tools from a middle palaeolithic site in italy 15 aeosoils surveyed in this region and the whitish surface patinae frequently developed on the neolithic bronze age lithic artifacts (magaldi et al., 1981; chelidonio & stocchiero, 1991; chelidonio & sommaruga, 2011). all artifacts are variably coated of carbonatic concretions. wet sieved sediments were carefully scrutinized in order to exclude any recent contamination of the vajo salsone lithic assemblage. we examined each artefact of module (length + width) greater than 4 cm in order to determine the main technological and typological features for an approximate total number of >10,000 items. the technological outlines of the major lithic production, together with the main typological and typometric features of retouched blanks and leaf points are described below in the results section. the conceptual and analytical approach to this preliminary inspection is inspired by several authors according to the main volumetric concepts in use during the middle palaeolithic (boëda, 1994; delagnes, 1992). moreover, it has been enriched with broader criteria for the definition of levallois predetermined products (grimaldi, 1995; guette, 2002) and with insights on the variability of the discoid core technology (peresani ed., 2003). volumetric blade technological features are consistent to what was assessed by inizan et al. (1999). we referred typological taxonomy to f. bordes, 1961. to provide a first reconstruction of the reduction sequences, we conducted morpho-technical and morphometric observations on cores, the complete levallois and other predetermined blanks, as well as certain by-products deemed to have had a significant role in the production, including the phase of the reduction sequence from which they were obtained. we did not conduct any systematic refitting of artifacts. technological outlines of the major lithic productions, together with the key typological features of the retouched blanks, are shown in the paragraphs below. 4.2. results: main technological outline the lithic industry does not contain any diagnostic artefact belonging to any of the upper palaleolithic blade-bladelet techno-typologically featured industries known in the area, like the uluzzian with the backed knives and splintered pieces (peresani et al., 2016; 2019), the aurignacian and proto-auignacian with the end-scrapers, retouched blades and bladelets, and bone industry (broglio, 1993; aleo et al., 2021), the early epigravettian with shouldered points (peresani et al., 2021) and the late epigravettian with the backed points, short endscrapers and microliths (broglio, 1992; montoya et al., 2018). the same holds for the mesolithic to bronze age technologically and typologically featured industries (broglio, 1992). the assemblage is mostly based on the use of the levallois method, as attested by predetermined blanks, abundant flat, elongated, cortical flakes and 50 levallois fig. 7 metacarpal of alces alces with linear butchering marks produced during the recovery of the meat mass (a) and scrapings, referable to the periosteum removing phase, associated to cupules produced by flint retouching (b). astragalus of cervus elaphus with a series of short and repeated cut-marks probably due to skinning (c). fragment of coxal bone ascribed to cervus elaphus showing a series of insistent cutmarks (d) and chopmarks (e) in proximity of the acetabulum associated to the disarticulation of the femur. 16 peresani m. et al. cores (tab.5). the set of finds ascribable to levallois core maintenance includes a wide range of items suggesting the use of various knapping strategies, such as the trimming of striking platforms, predetermination, the repair of flaking faces and the ablation of flaking accidents. all chert types were exploited: scaglia rossa, maiolica and san vigilio group. the levallois production consists of different reduction sequences based on recurrent unidirectional and centripete exploitation (fig. 8, nn. 1 and 2). these ones, at the same time, involve the application of technical variants related to the unidirectional modality. the initialization mostly concerned cortical nodules rather than plates and blocks, that were already naturally suitable for the predetermination of lateral and distal convexities. the blank was then processed, once that striking platforms were prepared while lateral convexities were shaped by means of detaching blades along the longest edges of the solid. the same procedure was used for distal convexities, which were either naturally shaped or improved with oblique or orthogonal removals to the core axis. the evidence related to unidirectional flakes reflects the intent of optimizing the exploitation of the volumes consistently with the technical criteria adopted during the main production phase, right up to deactivation. thanks to this optimisation strategy, the decortication and initial shaping of the core convexities were avoided. the striking platforms were faceted in an almost systematic manner, whereas the lateral convexities were created and maintained by means of ordinary and levallois core-edge removal flakes and the distal convexity was modelled with the removal of one or a series of moderately invasive flakes or from the ridges left by previous levallois removals. cores were exploited also by multidirectional levallois series from the very first stages of the reduction, and sometimes on both the faces of the core. centripetal modality had different roles in flake-making: it became active since both the first steps of core reduction and in the middle and final steps of the unidirectional sequence. this observation requires further confirmation, although several reasons might be already envisaged: hinged sensu lato unidirectional removals leading to the activation of new flaking axes for repair purposes; core reduction, with the consequent contraction in size to the detriment of the morpho-technical features of the predetermined blanks; routinary turning from unidirectional to orthogonal orientation of flake detachments with the core exploitation approaching the centripetal pattern with minimal modifications of the extenction of the striking platform. thus, flakes acquired variable edges showing either polygonal or fan-shaped outlines. except hinged or plunged flakes, or when the further re-shaping of the convexities is considered economically deficitary, the production ends with the reduction of the core volume. only few discards attributable to incipient fissurations, voids or other phenomena pinpointing to a poor selection of lithic raw materials have been observed. several flakes and some cores attest the exploitation of the lower faces of flake-cores obtained from fig. 8 selection of cores and artefacts representative of vajo salsone lithic assemblage: bifacial levallois cores exploited in the recurrent centripetal variant (1); unidirectional levallois core (2); centripetal core (3); overshot blade (4); mousterian point on a levallois blade (5); levallois centripetal flake (6); simple scraper on a laminar flake showing a burin-like detachment on the left edge (7). foliate tools from a middle palaeolithic site in italy 17 large cortical flakes. in these instances, knapping operations varied and they mostly involved the proximal zone, where the bulb could be directly removed once convexities were prepared. flakes are thin and invasive and the edges relatively long and regular, sometimes with the partial removal of the core-edge. discoid production is attested by very few centripete cores exploited on both surfaces for obtaining pseudo-levallois points, core-edge removal flakes and some centripete flakes. all these blanks were not retouched. cores display the typical biconvex outline with very limited remnants of cortical surface on one of the two faces and do not show any valuable evidence for reconstructing the origin of their reduction sequence. fig. 9 selection of leaf-shaped tools from vajo salsone: fragmented leaf points (1-2); fragmented and partially refitted leaf-shaped tool/ preform (3); bifacially leaf-shaped scraper (4); asymmetrical leaf knife (5); fragmented leaf point/knife (6). tab. 5 composition of vajo salsone retouched lithic assemblage according to the main tool types. 18 peresani m. et al. volumetric blade technology is mainly attested by laminar products and maintainance pieces, while blade cores are less abundant. the production of elongated artefacts is thus based both on levallois and laminar technologies: the latter can be recognized by thick blades characterized by curved profile, unidirectional or convergent scars and unprepared butt. blade production began when a natural edge was exploited on a major axis of the raw block. blade cores management was carried out through the detachments of lateral, partially-crested blades and overshot blades (fig. 8, n. 4). together with thick and wide blades, a production of thin bladelets is also attested, although not yet framed in their technological trajectories. bladelets could be obtained both from unipolar cores and from the burinlike reduction of flake blanks (fig. 8, n. 7). 4.3. results: retouched tools and bifacial tools retouched tools are mostly scrapers, followed by few points, notches and denticulates (fig. 8, nn. 5 and 6). scrapers are simple, double, often converging and occasionally transverse (tab. 5). marginally retouched flakes are rare. cortical and partially semicortical flakes were employed as well. we did not observe any evidence related to the utilization of flakes affected by accidents, fragmented flakes, recycled tools and cores. regarding scrapers, these tools were mostly shaped on unidirectional levallois flakes rather than centripete flakes, discoid flakes and blades. on the other hand, flakes and denticulates tended to be manufactured on cortical and flakes affected by imperfections, whereas points were made on levallois flakes. several scrapers, cortical flakes and levallois flakes were also thinned on the ventral face. artefacts yielding flat and invasive bifacial shaping represent one of the most distinctive features of vajo salsone lithic assemblage (fig. 9). at least 23 tools bear this type of retouch, characterized by a certain diversity in typology and raw material, chosen from those available locally: high quality, fine-grained cherts obtained from cretaceous limestone formations (maiolica, scaglia variegata alpina, scaglia rossa) represent the majority, while a couple of artefacts are manufactured on the coarse-grained chert from jurassic oolitic limestones. the foliate tools assemblage is almost exclusively composed by fragmented pieces (fig. 9), presumably abandoned on site as a result of the supervening fractures, characterized by the same heavy patinas affecting the knapping surfaces. a couple of rejoints of fragmented elements show the existence of very largesized, bifacially shaped tools with symmetrical lense-like sections, which presumably reached 15 cm in length when complete (fig. 9, n.3). a second rejoint allowed to reconstruct a preform 16 cm long, with large bifacial detachments and irregular edges, including a thick lateral portion used as striking platform. the manufacture of leaf-points from the further reduction of bifacial backed knives is a known model in central europe (nerudova & neruda, 2017), although in this instance the thick back might be hint of an unintentional residual due to the premature discharge of the tool. among the “finished” tools, only one is bearing a regular, thick back opposed to the bifacially-shaped edge (a leaf-knife), while the others are generally characterized by a bilateral techno-functional affinity as suggested by the two opposed cutting edges. these lateral edges are often symmetrical, ending in a pointed tip shaped by bilateral and bifacial flat retouching (fig. 9, n.1-2). when at least one end is present, the leaf-point tool-type can be often recognized. however, in some cases a light asymmetry between the two edges is attested. moreover, the tip could be curved or convex (fig. 9, n.5), maybe corresponding to the base of the fig. 10 dimensional scatter-plot of leaf-shaped tools from vajo salsone, grouped by tool sub-types. foliate tools from a middle palaeolithic site in italy 19 tool, or rounded as a consequence of the loss of functionality of the point. the edges of finished tools are extremely regular, with slightly convex sagittal profile; the sinuous edges belong to large-sized preforms, not yet subjected to the last refinement. in fact, the retouching stages are manifold. at the beginning, large and deep flakes are alternatively detached (presumably with the organic hammer) on both surfaces from the periphery of the tool. the next step is to regularize the thickness of the blank with invasive and flat detachments, prior to the refinement of the edges both in the longitudinal and sagittal views through scaled and more marginal detachments. bifacial symmetry can be observed on about half artefacts, while others have one surface flatter than the other. this feature is directly related to the initial blanks of the tools, which in several cases were recognized to be flakes or blades (fig. 9, n.4). in these cases, the retouching could range from partial to totally covering and therefore different than the retouching recorded on the leaf-points and leaf-knives. very few pieces (mainly preforms) seem to be shaped directly from raw blocks or plaquettes, while in most of the tools the raw blank is unrecognizable. moreover, some tools present a strong bifacial asymmetry and flat-convex transversal section, with scalar retouching on the upper face: these tools might be classified as bifacial or leaf-shaped scrapers (fig. 9, nn. 4-6). since these are almost exclusively fragmented tools, a dimensional plot showing width and thickness has been produced (fig. 10). according to it, leaf-points and knives clearly overlap leaf-shaped flakes and blades, taking in account that the latter are less bifacially symmetrical. leaf-shaped scrapers are significantly thicker, implying different tool-types both in functionality and manufacturing stages. preforms record larger sizes, although already defined in a bifacial and bilateral symmetry. 5. discussion 5.1. a model of the morfo-dynamic evolution of the slope and the genesis of the karst infill the geomorphological environment in which the site is located is characterized by a rock wall and a belt of the slope immediately below it. the wall is affected by the formation of large niches rockshelter-like, and locally also by the development of karst caves and pits. niche formation is explained by the slow circulation of water within the fractures and pores of the rock with consequent processes of clastic weathering and chemical erosion. niches originate where the rock is most porous and / or fractured. the wall is also affected by collapse and toppling phenomena of large blocks of rock, favored by chemical erosion and often triggered by seismotectonic events, such as high intensity earthquakes. the slope immediately below the wall is affected by these rockfall events with consequent crushing of the rock into both minute and coarse fragments, to constitute discontinuous coverings of diamicton, interpretable as seismites, which can contribute to the filling of karst cavities such as pits or relict portions of caves. seismites are hardly or not at all cemented, due to the slope processes and the repetition of the collapse fig. 11 reconstruction of the morfo-dynamic evolution of the vajo salsone slope with indication of the main formation process of the karst infill. 20 peresani m. et al. events. inside the diamicton covers, conduits attributable to piping-type processes were observed, resulting from the flow of water and the removal of the finest rock fragments. therefore, given this geomorphological context, the following hypothesis concerning the genesis of the site may be suggested: 1) the basal part of the wall presents a large shelter under the rock in which groups of neanderthals settled depositing anthropogenic sediments containing both flint tools and animal bones; 2) following phenomena of rockfall and toppling of large blocks occurred, with consequent retreat of the wall and dismantling of the large shelter-niche; 3) the sediments of the shelter, in addition to calcite flowstones fragments, have been exposed to the process of washout and transported along a suffusion conduit inside the diamicton cover, up to their accumulation place: a small karst pit interested by the formation of calcite flowstones below the diamicton cover. this pit functioned as a sedimentary trap. it follows that, if seismic events of strong intensity (see, for example, the verona earthquake of 1117) have occurred, in the most fragile areas, such as those located in proximity of the faults with e-w orientation, crossing the n-s elongated tectonic blocks, repeated collapses occurred, with the formation of covers of seismites. the formation of the archaeological deposit inside the sedimentary trap is contextual to the sedimentation of clasts resulted by the overlying diamicton and of fragmented speleothemes, as the finds were found both in the interstitial spaces between the blocks and crushed between each others (fig. 11). the arrangement of all these elements appears chaotic, indicating a massive sedimentary process, a fact that seems to confirm an important event of collapse of an overlying structure (cave or shelter?) which was the primary location of the archaeological record. the state of conservation of the artifacts, mostly damaged by very fresh mechanical fractures, linked to the action of mines but without traces of floating and prolonged transport suggests that the primary deposition site should not have been very far from the one of the discovery. this sedimentary evolution hinders the possibility of discriminating any frequentations distributed over a chronological interval which, however, remains to be determined. the only possible approximation would lead to consider a limited range: a broad stratification would be expressed by a greater variety in the faunal spectrum, by possible taphonomic differences between the artifacts, as well as by a greater variability in the techno-typological characteristics of the lithic industry, as instead is detected by cultural sequences that include well distinct levels of mousterian industries with quina, discoid and levallois technology, the latter declined in a series of techno-economic and typometric aspects (eg fumane cave: peresani, 2012; san bernardino cave: peresani, 1996). 5.2. mammal fauna, ecology, and possible chronological range according to preliminary results obtained from the study, the faunal spectrum is mainly composed of medium and large sized ungulates, with a clear prevalence of red deer and few remains of roe deer, chamois and elk. regarding the ecological context, this faunal assemblage is representative of close and open forests with transitive and discontinuous alpine grasslands or sparse vegetation on carbonate rocks (an environment vital to ibex), completed by humid environments and watercourses. the dominance of red deer and roe deer may suggests that forests were commonly the neanderthals’ most exploited hunting environment. however, caution is needed in declaring this assumption given the ecological plasticity of these kind of cervids, which can live in different ecosystems, although the roe deer primary habitat is forest clearings, hedges, and woodland edge (danilkin, 1996; geist, 1999). nevertheless, the low number of remains attributed to elk suggests the presence of humid areas presumably in the valley bottom, as attested by currently available evidence from fumane cave (cassoli & tagliacozzo, 1994; peresani et al., 2011; romandini et al., 2014), tagliente rockshelter (thun hohenstein & peretto, 2005) and san bernardino cave (terlato et al., 2019). the high incidence of cervids is consistent with the faunal records from the late middle palaeolithic stratigraphic sequence of fumane which, from units a11-a10 shows a progressive increase of these species to the detriment of those favoring open environments (fiore et al., 2004; romandini et al., 2020). dominance of cervids is also recorded at tagliente (thun-hohenstein & peretto, 2005) and san bernardino in layers of comparable age (terlato et al., 2021). moreover, the absence of large bovids at vajo salsone despite their representativeness of ecological conditions diversity, spanning from dense forests with wetlands and small streams, to hilly grasslands and plains, disagrees with the presence, although ephemeral, of these ungulates at both fumane and tagliente (terlato et al., 2019) and, above all, at de nadale cave in the berici hills, where the higher frequency of bovids has also been related to the mis 4 age of this site (livraghi et al., 2021). therefore, despite being so preliminar, these first data of the vajo salsone faunal assemblage agree with ecological contexts existing at the regional scale during mis 4 and mis 3, thus supporting this chronological position for the site. the main reference vegetation data in the alpine foreland are provided from the fimon pollen core, where persistent afforestation (eventually limited during millennial scale cold events) is recorded throughout the entire early and middle part of the last glaciation (early to middle würm; pini et al., 2010). mis 3 records clear evidence of afforestation persisting at a long-term scale south of the alps, although forest withdrawals with expansion of grasslands and dry shrublands occurred as a consequence of colder climatic conditions (badino et al., 2020) which reinforced the presence of alpine ibex, chamois, and marmot at low altitudes, as well as the presence of micromammals in steppic environments, and the diffusion of birds in open environments (romandini et al., 2020). however, these conditions are not recorded at vajo salone. concerning carnivores, the presence of wolf at vajo salsone and other sites in the region confirms the existence of open foliate tools from a middle palaeolithic site in italy 21 spaces and an abundant ungulate biomass, whereas, red fox is suited to a predominantly forested landscape. 5.3. a first insight on the origin of the zooarchaeological assemblage according to the taphonomic data, anthropic modifications such as cutmarks, scraping marks and impacts have been recognized on cervid bones (red deer, elk), showing that during this phase of occupation of the vajo salsone site, hunting activity was mainly focused on this ungulate. hunting and related activities of this ungulate are largely recorded in the pre-alpine belt, where taphonomic data indicate that the predominant association of game is consistent with the ecological conditions in the proximity of each specific site and shows shifts correlated with the most relevant climatic oscillations. de nadale cave in the berici hills was frequented by hunters of giant deer, red deer, bison and auroch during mis 4 (livraghi et al., 2021). san bernardino cave, fumane cave and tagliente rockshelter during mis 3 share similar exploitation models consisting of the selection of young adult and adult prey and of primary butchering. the main hunted ungulates during the final mousterian were thus mostly red deer, roe deer and giant deer with lesser amounts of chamois and ibex (fiore et al., 2004; thun hohenstein & peretto, 2005; peresani et al., 2011; romandini et al., 2014; terlato et al., 2021) and limited exploitation of elk, wild boar and bos/bison (terlato et al., 2019). the exploitation of marmots, beavers (romandini et al., 2018a) and of some carnivores like bear, wolf and fox (romandini et al., 2018b) is also documented and suggests recovery for meat, marrow and fur. 5.4. the cultural outline of vajo salsone in the north -eastern italy even though most of the evidence from the vajo salsone assemblage is comparable with that of other sites in the region and the northern mediterranean area, it does provide new details of the late pleistocene cultural scenario and contributes in making the middle paleolithic picture more complex. not surprisingly, as it occurred in almost all sites around the north-adriatic region, levallois technology is largely prevalent in the lithic industries. this flaking method either forms the substrate or contributes to cultural complexes traditionally labelled as typical mousterian rich in scrapers, eastern charentian mousterian, pontinian, in a large area from the rhône valley to the western balkans along the alpine arch and apennine ridge, displaying variations in each different facies in relation to the frequence of retouched tools and other aspects (palma di cesnola, 1996; peretto, 1992). nevertheless, none of these industries had the specific target of producing neither points nor converging scrapers at a so relevant number like at vajo salsone. although it is still lacking of a precise chronological position, the levallois technology of vajo salsone is as much variable as other sites even in the alpine footbelt (peresani, 2001) and subalpine area like monte versa on the euganean hills (attributed to the last interglacial; peresani, 2000-2001), monticello (undated, duches & peresani, 2009) and cavaso del tomba (undated: de stefani et al., 1999-2001), among others. at vajo salsone, this system mostly focused on longer-thanwide blanks using the unidirectional recurrent modality and, to a lesser extent, by means of centripetal flakemaking as it has been observed in the alpine foreland at sites dated to mis 3 (peresani, 2011; delpiano et al., 2019b), and along the northern slope of the apennines (lenzi & nenzioni, 1996; fontana et al., 2018). furthermore, at the present state we cannot confirm whether the different modalities (unidirectional and centripetal) expressed by the levallois variability at vajo salsone relate to different core surface maintenance strategies aimed at the setting of specific predetermination parameters for each lithic material exploited (coarsely vs finely texture chert). as a matter of fact, locally available resources were employed for flake-making, with a subtle prevalence of maiolica and scaglia rossa over the coarser materials catched in the carbonatic sandstones along the vajo salsone slope. as the provisioning of nodules, blocks and plates appears to be unconstrained in the site surroundings we did not observe the use of stream pebbles -, then preferences in relation to the main flaking modalities employed might be related to specific technical economical requirements. further analyses are needed to verify whether mechanical aptitude of the chert types or economic reasons shall be considered forcing agents in the design of tool sets. nonetheless, these latter were produced through the exploitation of all kinds of raw material. moreover, throughout the observation of the examined assemblage we did not record the presence of the same levallois reduction patterns already attested in certain stratified sequences, where the unidirectional exploitation systematically turned to the centripetal one when approaching the end of core reduction (peresani, 1996; 2012). on the contrary, in our instance unidirectional exploitation was applied until almost the end of the reduction sequence, as the presence of elongated flakes with thin and regular edges selected for the side and converging scrapers suggests. these patterns show that the above goals were achieved constantly, without caring for the optimization of the available resources, which may have not been subject to deficiencies in terms of either quality or quantity. on a regional scale, at open-air sites the levallois reduction stops at an intermediate grade of the potential exploitation. conversely, in shelters the exploitation was more exhaustive and affected structural and typometric arrangements, to such an extent that microlithism was observed in some assemblages (peresani, 1996). settlement dynamics were thus responsible both for fractionation in reduction sequences and for variations in the grade of retouching of the predetermined blanks and by-products, these latter being left unretouched at vajo salsone. still, although preliminary, the data presented here express one further element of lithic variability which consists in the co-presence of the discoid and laminar volumetric concepts, whereas we do not exclude other more expeditious productions. discoid industries have 22 peresani m. et al. been described at fumane and rio secco caves, where a high resolution in neanderthal occupations within the first part of mis 3 shows diachronic variability framed in cultural and behavioural contexts. at fumane, the discoid concept substitutes the levallois along a densely stratified sequence (peresani, 2012; delpiano et al., 2018), while at rio secco it is found in the same context with the levallois (peresani et al., 2014). concerning volumetric laminar production, it is ephemeral in the area and only represented by bladelet making at fumane unit a5-a6 (peresani et al., 2013) or remains poorly known and undated as at tagliente (carmignani, 2021). 5.5. foliate tools: comparing evidence in italy and behind the alps the foliate tools of vajo salsone, including leaf points, knives and leaf-shaped flakes, are a unique evidence for the northern adriatic region. nonetheless, in the southern margin of the po plain, where tens of open-air lower and middle palaeolithic sites are preserved on the pleistocene terraces of the lower apennines of emilia-romagna, five sites located between bologna and imola (fig. 1) contain isolated and sometimes fragmented leaf-points, found in assemblages characterized by developed laminar tendency achieved with the levallois method. these sites are generally related to the bellaria/san biagio stratigraphic unit that is supposed to be framed in mis 7 and covered by mis 6 loess (fontana et al., 2010; 2018). however, lack of absolute dating raised questions and issues: indeed, there would be a chronological divergence between these and other regional levallois complexes that recently yielded mis 4 (ghiardo) or early mis 3 (monte netto) dates (cremaschi et al., 2015; delpiano et al., 2019b). outside the boundaries of the great adriatic po region, archaeological sites yielding middle palaeolithic leaf-points are mainly situated in the southern part of germany, spreading along the danube and its tributaries in an e-w direction. most of the sites are located in the swabian and franconian jura, preserved in caves and rock-shelters, but also in open air sites resulting from surface collections of isolated leaf-points. the highest number of leaf-points has been found in bavaria, decreasing towards west and north. assemblages of southern germany containing leaf-points attracted scientific attention very early in the 20th century. except for a few examples, these sites have been excavated within the first half of the last century and, due to this reason, they are affected by lacking documentation, unreliable chronology and poor contextual information (uthmeier, 2004; richter, 2009). since the pioneering work of g. freund, and later t. uthmeier (2004) and m. bolus (2004), no comprehensive research study focused exclusively on leaf-points and their role in the late middle palaeolithic of southern central europe. both uthmeier (2004) and bolus (2004), as well as richter (2009), hypothesized that leaf-point assemblages in southern germany are part of the regional middle palaeolithic (richter, 1997) and should not be interpreted as an innovative behaviour of late neanderthals. rather, leaf-points might be related to specific task activities, probably hunting, within the context of a larger settlement system. nonetheless, leaf points are often considered as cultural expressions of late pleistocene neanderthals in europe. particularly relevant to this issue is the socalled szeletian (allsworth-jones, 1986), an archaeological leaf-points complex distributed in poland, hungary and moravia, although it is still far from being clearly defined in time, space and technological characteristics of stone tool production (mester, 2018). to the west, in southern germany, the outshoot of the szeletian should be considered the so-called altmühlian (bohmers, 1939, 1951) despite the significance of this complex as transitional industry has been recently discussed (richter, 1997; bolus, 2004; uthmeier, 2004) being lately considered as the last phase of keilmessergruppen/m.m.o. complex, which is the main cultural expression of central european neanderthals (richter, 2016; delpiano & uthmeier, 2020). for bavaria, only the so-called lincombian-ranisian-jerzmanovician (lrj) (flas, 2011) is accepted as a potential transitional complex leading from the middle to the upper palaeolithic. further east, the bohunician complex is widespread in moravia, where it is characterized by levallois alongside blade technology, with the presence of bifacial leaf-points in some sites (tostevin & skrdla, 2006); however, doubts have been raised on the links between bohunician and the neighboring transitional technocomplexes (neruda, 2009). incertitude thus concerns the chronology and geographic distribution of complexes in central and eastern europe containing bifacially worked leaf-points. furthermore, foliates do not seem to be constrained to the phase immediately before the upper palaeolithic, but may appear discontinuously and selectively from possibly as early as mis 7 to mis 3. sites bearing leaf-shaped tools in the balkans and in northern germany appear to belong to mis 5 or mis 7, even though bifacial reshaping and rejuvenation may have had heavily modified tools initially manufactured with a totally different conception (kot, 2017). in vajo salsone, both leaf-points, leaf-knives and other leafshaped flake tools are attested, abandoned at different manufacturing stages. these data suggest that they were possibly produced directly according to this mental template, rather than representing a consequence of the reduction of unifacial tools or other bifacial tools. 6. conclusions the discovery of the site of vajo salsone contributes to shed new lights on the complexity of the middle palaeolithic in the north of italy, where mousterian industries are mostly based on the application of the levallois technology, as recorded from cave and open air sites dated from mis 7 to early mis 3. this cultural scenario is not static. in fact, quina and discoid technologically related industries are documented as well, except for few contexts. furthermore, the discovery of leaf points, knives and leaf-shaped flakes in the alpine footbelt reinforces our view about the variability of the neanderthal world, thus providing a unique evidence not foliate tools from a middle palaeolithic site in italy 23 only for the north of italy but also for the whole adriatic region. it confirms the reliability of previous findings reported at open-air sites on the northern slope of the apennines, although isolated from their originary pedostratigraphic contexts. dating the apennine and vajo salsone evidence using biostratigraphic and geochronological methods, whenever these can be applied, is needed for assessing the values of affinities or differences between the foliate tools featured industries at the south and the north of the alpine range, in terms of biological and cultural population dynamics. acknowledgements the authors are indebted to the archaeological superintendence (dott. gianni de zuccato, soprintendenza archeologia, belle arti e paesaggio per le provincie di verona, vicenza e rovigo) for permission to the study of the archaeological assemblage, to refill s.r.l. the owner of the vajo salsone area for making possible excavation and for access the site area, to all students and collaborators of the university of ferrara who sieved and carefully scrutinized archaeological sediments and two reviewers who contributed to strengthen our paper. g. cattabriga revised the english text. authors contributions: m.p. designed and directed fieldwork and studies at vajo salsone, d.v. and a.p. conducted the rescue excavation, u.s. analyzed the geomorphological context, d.v. and a.p. provided field description of the stratigraphy and sediments, g.a. and u.t.h. examined archaeofauna remains, j.m.l.g and h.a.b. examined the small vertebrates, d.d., v.e. and m.p. analyzed the lithic assemblage, d.m. made the geomorphological map, lb., c.f., f.p., p.p. treated and prepared artefacts and bones for analysis, m.p. wrote and composed the manuscript with contributions by g.a., d.d, h.a.b., j.m.l.g., a.p., u.s., d.v., y.t., and u.t.h. references aleo a., duches r., falcucci a., rots v., peresani m., (2021) scraping hide in the early upper paleolithic: insights into the life and function of the protoaurignacian endscrapers at fumane cave. archaeological and anthropological sciences, 13, 137. allsworth-jones p. (1986) the szeletian and the transition from middle to upper palaeolithic in central europe. clarendon press, oxford. amori g., contoli l., nappi a. (2008) fauna d’italia. mammalia ii. erinaceomorpha, soricomorpha, lagomorpha, rodentia, calderini, milano. aspes a. (2003) preistoria veronese. contributi e aggiornamenti. memorie del museo civico di storia naturale di verona, ii serie, sezione scienze dell’uomo, 5. badino f., pini r., ravazzi c., margaritora d., arrighi s., bortolini e., figus c., giaccio b., lugli f., marciani g., monegato g., moroni a., negrino f., oxilia g., peresani m., romandini m., ronchitelli a., spinapolice e.e., zerboni a., benazzi s. (2020) an overview of alpine and mediterranean palaeogeography, terrestrial ecosystems and climate history during mis 3 with focus on the middle to upper palaeolithic transition. quaternary international, 551, 7-28. barone r. (1980) anatomia comparata dei mammiferi domestici. vol. 1: osteologia. bologna. beherensmeyer a.k., (1978) taphonomic and ecological information from bone weathering. paleobiology, 4, 150-162. bennett j.l. (1999) thermal alteration of buried bone. journal of archaeological science, 26, 1-8. berto c., (2013) distribuzione ed evoluzione delle associazioni a piccoli mammiferi nella peninsola italiana durante il pleistocene superiore (phd thesis). università degli studi di ferrara, ferrara. berto c., lópez-garcía j.m., luzi e. (2019) changes in the late pleistocene small-mammal distribution in the italian peninsula. quaternary science reviews, 225, 106019. berto c., luzi e., montanari g., guerreschi a., fontana f. (2018) climate and landscape in italy during late epigravettian. the late glacial small mammal sequence of riparo tagliente (stallavena di grezzana, verona, italy). quat. sci. rev., 184, 132-142. bertola s. (2016) southern alps (trento plateau) and northern apennines cherts: ages and distribution. in: ressources lithiques, productions et transferts entre alpes et méditerranée. séances de la spf, 55-75. binford l.r. (1981) bones: ancient men and modern myths. ny academic, 320. binford l.r. (1984) faunal remains from klasies river mouth. academic press, orlando, 305. bini a., cita m.b., gaetani m. (1978) southern alpine lakes; hypothesis of an erosional origin related to the messinian entrenchment. in: cita m.b., ryan w. b. f. (eds). messinian erosional surfaces in the mediterranean. marine geology, 27 (3-4), 271 288. blasco r., rosell j., fernández peris j., cáceres i., vergés j.m. (2008) a new element of trampling: an experimental application on the level xii faunal record of bolomor cave (valencia, spain). journal of archaeological science, 35, 1605-1618 boëda é. (1994) le concept levallois: variabilité des mèthodes. monographies centre rercherches archéologiques 9, cnrs, 280 bohmers a.(1939) die ausgrabungen in den höhlen von mauern. germanien 4, 151-156. bohmers a. (1951) die höhlen von mauern. palaeohistoria, 1, 1-107. j. b. wolters, groningen. bolus m. (2004) settlement analysis of sites of the blattspitzen complex in central europe in: conard, n.j. (ed.), settlement dynamics of the middle palaeolithic and middle stone age, 201-226. kerns verlag, tubingen. bordes f. (1961) . typologie du paléolithique ancien et moyen. institut préhistoire universitè bordeaux 1, 81. bosellini a., carraro f., corsi m., de vecchi g.p., gatto g.o., malaroda r., sturani c., ungaro s., zanettin 24 peresani m. et al. b. (1967) foglio 49 verona. note illustrative della carta geologica d’italia. servizio geologico d’italia, roma. brain c.k. (1981) the hunter or the hunted? an introduction to african cave taphonomy. university of chicago press, chicago, 376. broglio a. (1992) mountain sites in the context of the north-east italian upper palaeolithic and mesolithic. proc. preistoria alpina, 28/1, 293-310. broglio a. (1993) l'aurignacien au sud des alpes. actes xii congrès int. sciences préhist. protohist. bratislava 1991, 193-203. broglio a., de stefani m., tagliacozzo a., gurioli f., facciolo a. (2006) aurignacian dwelling structures, hunting strategies and seasonality in the fumane cave (lessini mountains). in: vasilev s.a., popov v.v., anikovich m.v., praslov n.d., sinitsyn a.a., hoffecker j.f. (eds.), kostenki and the early upper paleolithic of eurasia: general trends, local developments. nestor-historia, saint petersburg, 263-268. carmignani l. (2021) between the flake and the blade: associated systems of production at riparo tagliente (veneto, northern italy). journal of lithic studies, 4/1, 1-37. carraro f., malaroda r., piccoli g., sturani c., venzo s. (1969) note illustrative della carta geologica d’italia alla scala 1:100000. foglio 48 peschiera del garda, ministero dell’industria del commercio e dell’artigianato. direzione generale delle miniere. servizio geologico d’italia, poligrafica e cartavalori, ercolano. cassoli p.f., tagliacozzo a. (1994) i resti ossei di macromammiferi, uccelli e pesci della grotta maggiore di san bernardino sui colli berici (vi): considerazioni paleoeconomiche, paleoecologiche e cronologiche. bullettino di paletnologia, 85, 1-71. castellarin a. (1981) carta tettonica delle alpi meridionali alla scala 1:200.000. c.n.r., p.f. geodinamica, 441, 220. castellarin a., vai g.b., cantelli l. (2006) the alpine evolution of the southern alps around the giudicarie faults: late cretaceous to early eocene transfer zone. tectonophysics, 414, 203-223. castiglioni g.b., cremaschi m., guerreschi a., meneghel m., sauro u., van vliet lanoë b. (1990) the loess deposits in the lessini plateau, in cremaschi m. (ed.), the loess in northern and central italy: a loess basin between the alps and the mediterranean region. quaderni di geodinamica alpina e quaternaria, 1, 41-59. chelidonio g., sommaruga m. (2011) morfologie e tracce di frequentazioni paleolitiche a monte vegro (illasi). la lessinia ieri oggi domani, 79-86. chelidonio g., stocchiero l. (1991) monte precastio (tregnago/verona): prime note sulla nuova segnalazione di un sito riferibile al paleolitico inferioremedio nella lessinia orientale. quaderni di archeologia del veneto, vii, 123-135. colamussi v. (2002) studi climatici sul quaternario mediante l’uso dei micromammiferi (phd thesis). universita di ferrara, firenze, parma. cremaschi m. (1990) depositional and postdepositional processes in rock shelters of northern italy during the late pleistocene: their paleoclimatic and paleoenvironmental significance. quaternaire, 1, 51-64. cremaschi m., zerboni a., nicosia c., negrino f., rodnight h., spötl c. (2015) age, soil-forming processes, and archaeology of the loess deposits at the apennine margin of the po plain (northern italy): new insights from the ghiardo area. quaternary international, 376, 173-188. danilkin a. (1996) behavioural ecology of siberian and european roe deer. chapman & hall, london, 300. de stefani m., peresani m. (1999-2001) il paleolitico della valcavasia (prealpi trevigiane). atti società preistoria e protostoria friuli-venezia giulia, xii, 127-149. de zanche v., sorbini l., spagna v. (1977) geologia del territorio del comune di verona. memorie museo civico di storia naturale di verona (ii s.), sez. sc. terra, 1, 51. delagnes a. (1992) l’organisation de la production lithique au paléolithique moyen: approche technologique à partir de l’étude des industries de la chaise-de-vouthon (charente). phd dissertation, université paris x. delpiano d., heasley k., peresani m. (2018) assessing neanderthal land use and lithic raw material management in discoid technology. journal of anthropological science, 96, 1-22. delpiano d., zupancich a., peresani m. (2019a). innovative neanderthals: results from an integrated analytical approach applied to backed stone tools. journal of archaeological science, 110, 105011. delpiano d., peresani m., bertola s., cremaschi m., zerboni a. (2019b) lashed by the wind. shortterm middle palaeolithic occupations within the loess-palaeosoil sequence at monte netto (northern italy). quaternary international, 502, 137 -147. delpiano d., uthmeier t. (2020) techno-functional and 3d shape analysis applied for investigating the variability of backed tools in the late middle paleolithic of central europe. plos one 15, 1-55. domínguez-rodrigo m., de juana s., galán a., rodríguez m. (2009) a new protocol to differentiate trampling marks from butchery cut marks. journal of archaeological science 36, 2643-2654. domínguez-rodrigo m., piqueras a. (2003) the use of tooth pits to identify carnivore taxa in tooth-marked archeofaunas and their relevance to reconstruct hominid carcass processing behaviors. journal of archaeological science, 30, 1385-1391. duches r., peresani m. (2009) tra monti berici e colli euganei nel paleolitico. interpretazione preliminare del sito di monticello di barbarano (vi) sulla base dello studio tecno-economico dell’insieme litico. preistoria alpina, 44, 159-171. fernández-jalvo y., andrews p. (2016) atlas of taphonomic identifications. vertebrate paleobiology and paleoanthropology series, springer. foliate tools from a middle palaeolithic site in italy 25 fiore i., gala m., tagliacozzo a. (2004) ecology and subsistence strategies in the eastern italian alps during the middle palaeolithic. international journal osteoarchaeology, 14, 273-286. fischer j.w. (1995) bone surface modifications in zooarchaeology. journal of archaeological method and theory, 2, 7-68. flas d. (2011) the middle to upper paleolithic transition in northern europe: the lincombian-ranisianjerzmanowician and the issue of acculturation of the last neanderthals. world archaeology, 43(4), 605-627. fontana f., nenzioni g., peretto c. (2010) the southern po plain area ( italy ) in the mid-late pleistocene�: human occupation and technical behaviours. quaternary international, 223-224, 465471. fontana f., nenzioni g., pagani c. (2018) depositi paleolitici e industrie nell’area bolognese orientale. nuovi dati e dinamiche interpretative (a cura di f. lenzi). museo della preistoria luigi donini e istituto beni culturali della regione emilia romagna. galadini f., galli p., cittadini a., giaccio b. (2001) late quaternary fault movements in the baldolessini mts sector of the southalpine area (northern italy). netherlands journal of geosciences/geologie en mijnbouw, 80, 187-208. galán a.b., rodríguez m., de juana s., domínguezrodrigo m. (2009) a new experimental study on percussion marks and notches and their bearing on the interpretation of hammerstone-broken faunal assemblages. journal of archaeological science, 36, 776-784. geist v. (1999) deer of the world. swan hill press, shrewsbury, england, 432. grayson d. k. (1984) quantitative zooarchaeology, academic press, new york. grimaldi s. (1996) mousterian reduction sequences in central italy. in: bietti a., grimaldi s. (eds.), reduction processes (châines opératoires) in the european mousterian. quaternaria nova, vi, 279310. guette c. (2002) révision critique du concept de débitage levallois à travers l’étude du gisement moustérien de saint-vaast-la-hougue/le fort (chantiers i-iii et ii, niveaux inférieurs) (manche, franche). bulletin de la société préhistorique française, 99 (2), 237-248. guidoboni e., comastri a., boschi e. (2005) the ‘‘exceptional’’ earthquake of 3 january 1117 in the verona area (northern italy): a critical time review and detection of two lost earthquakes (lower germany and tuscany). journal of geophysical research, 110b, 20. guidoboni e., g. ferrari, postpischl d. (1985) il terremoto del 3 gennaio 1117, p. 810., 47 foto, 12 mappe, rep. rpt 37/85, enel, rome. habemehl k. h. (1961) altersbestimmung bei haustieren, peltzieren und beim jagdbaren. paul parey, berlin, germany. higham t.f.g., brock f., peresani m., broglio a., wood r., douka k. (2009) problems with radiocarbon dating the middle and upper palaeolithic transition in italy. quaternary science reviews, 28, 12571267. inizan m.l., reduron-ballinger m., roche h., tixier j. (1999) technology and terminology of knapped stone, préhistorie de la pierre taillée, tome 5, crep, nanterre. jéquier c., peresani m., romandini m., delpiano d., joannes-boyau r., lembo g., livraghi a., lópezgarcía j.m., obradovi� m., nicosia c. (2015) the de nadale cave, a single layered quina mousterian site in the north of italy. quartär, 62, 7-21. klein, r. g., cruz-uribe, k. (1984) the analysis of animal bones from archeological sites, the university of chicago press, chicago. kot m. (2017) bifacial and unifacial technology: a real difference or a problem of typo-technological approach? the example of the ehringsdorf assemblage. quaternary international, 428, 66-78. lenzi f., nenzioni g. (1996) lettere di pietra. i depositi pleistocenici: sedimenti, industrie e faune del margine appenninico bolognese. editrice compositori, bologna. livraghi a., fanfarillo g., dal colle m., romandini m., peresani m. (2021) neanderthal ecology and exploitation of cervids at the onset of mis4: a study on de nadale cave, italy. quaternary international, 586, 24-41. lópez-garcía j.m. (2011) los micromamíferos del pleistoceno superior de la península ibérica. evolución de la diversidad taxonómica y cambios paleo-ambientales y paleoclimáticos. editorial académica española, saarbrücken, 368. lópez-garcía j.m., berto c., peresani m. (2019) environmental and climatic context of the hominin occurrence in northeastern italy from the late middle to late pleistocene inferred from small-mammal assemblages. quateranry science reviews, 216, 18-33. lópez-garcía j.m., dalla valle c., cremaschi m., peresani m. (2015) reconstruction of the neanderthal and modern human landscape and climate from the fumane cave sequence (verona, italy) using small-mammal assemblages. quaternary science reviews, 128, 1-13. lópez-garcía j.m., luzi e., peresani m. (2017) middle to late pleistocene environmental and climatic reconstruction of the human occurrence at grotta maggiore di san bernardino (vicenza, italy) through the small-mammal assemblage. quaternary science reviews, 168, 42-54. lyman r.l. (1994) vertebrate taphonomy. cambridge university press, cambridge. magaldi d., peretto c., sauro u. (1981) depositi di versnte contenenti reperti del paleolitico inferiore nell’alta valpantena. bollettino museo storia naturale di verona, vii, 657-673. magaldi d. & sauro u. (1982) landforms and soil evolution in some karstic areas of the lessini mountains and monte baldo (verona, northern italy). geografia fisica dinamica quaternaria, 5, 82-101. mallow d., ludwig d., nilson g. (2003) true vipers: 26 peresani m. et al. natural history and toxinology of old world vipers. malabar, florida: krieger publishing company. mallye j.b., thiébaut c., mourre v., costamagno s., claud e., weisbeckerg p. (2012) the mousterian bone retouchers of noisetier cave: experimentation and identification of marks. journal of archaeological science, 39, 1131-1142. mantovani e., brancolini g., babbucci d., tamburelli c., viti m. (2021) possible multiple sources of the strong 1117 po plain earthquake, inferred from the plio-quaternary evolution of the northern adriatic area. international journal of geosciences, 12, 381-403. margaritora d., dozio a., chelidonio g., turrini m.c., peresani m. (2020) the lower and middle palaeolithic settlements in the baldo-lessini mountains. results from a gis investigation. alpine and mediterranean quaternary, 33/1, 115-132. mariezkurrena k. (1983) contribution al conocimiento del desarrollo de la denticion y el esqueleto postcraneal de cervus elaphus, «munibe», 35, 149202. massironi m, zampieri d., bianchi m, schiavo a, franceschini a. (2009) use of psinsar data to infer active tectonics: clues on the differential uplift across the giudicarie belt. tectonophysics, 476, 363-369. mester z. (2018) the problems of the szeletian as seen from hungary. recherches archéologiques, 9, 19-48. mietto p., sauro u. (2000) le grotte del veneto: paesaggi carsici e grotte del veneto, regione veneto. la grafica editrice, verona, 480. montoya c., duches r., fontana f., peresani m., visentin d. (2018) peuplement tardiglaciaire et holocène ancien des préalpes de la vénétie (italie nord orientale): éléments de confrontation. in: averbouh a., bonnet-jacquement p., cleyet-merle j.-j. (dirs.) l’aquitaine à la fin des temps glaciaires aquitaine at the end of the ice age. les sociétés de la transition du paléolithique final au début du mésolithique dans l’espace nord aquitain. paleo, numéro spécial, 193-202. neruda p. (2009) moravia during ois 3: cultural relations. praehistoria, 9-10, 125-147. nerudova z., neruda (2017) technology of moravian early szeletian leaf point shaping: a case study of refittings from moravský krumlov iv open-air site (czech republic). quaternary international, 428, 91-108. pales l., garcia m.a. (1981) atlas osteologique pour servir a l’identification des mammiferes du quaternaire. éditions du centre national de la recherche scientifique, paris. pales l., lambert c. (1971) atlas osteologique pour servir a l’identification des mammiferes du quaternaire. éditions du centre national de la recherche scientifique, paris. palma di cesnola a. (1996) le paléolithique inférieur et moyen en italie. millon ed. peresani m. (1996) the levallois reduction strategy at the cave of san bernardino (northern italy). in bietti a., grimaldi s. (eds.) reduction processes (châines opératoires) in the european mousterian. proc. international round table, quaternaria nova, vi, 205-236. peresani m. (2000-2001) il paleolitico medio dei colli euganei (veneto): stratigrafia e industria litica del sito di monte versa. rivista di scienze preistoriche, li, 73-137. peresani m. (2001) an overview of the middle palaeolithic settlement system in north-eastern italy. in n.j.conard (ed.), settlement dynamics of the middle palaeolithic and middle stone age. tübingen publications in prehistory, introductory volume, verlag, 485-506. peresani, m. (ed.) (2003) discoid lithic technology. advances and implications. british archaeological reports, international series 1120. peresani m. (2011) the end of the middle palaeolithic in the italian alps. an overview on neandertal land -use, subsistence and technology. in: conards n., richter j. (eds.), neanderthal lifeways, subsistence and technology. one hundred fifty years of neanderthal study. vertebrate paleobiology and paleoanthropology series, springer ed., 249-259. peresani m. (2012) fifty thousand years of flint knapping and tool shaping across the mousterian and uluzzian sequence of fumane cave. quaternary international, 247, 125-150. peresani m., bertola s., delpiano d., benazzi s., romandini m. (2019) the uluzzian in the north of italy. insights around the new evidence at riparo broion rockshelter. archaeological and anthropological sciences, 11(7), 3503-3536. peresani m., centi di taranto l.e. (2013) blades, bladelets and flakes: a case of variability in tool design at the onset of the middle upper palaeolithic transition in italy. comptes rendus palevol, 12/4, 211-221. peresani m., chrzavzez j., danti a., de march m., duches r., gurioli f., muratori s., romandini m., tagliacozzo a., trombino l. (2011) fire-places, frequentations and the environmental setting of the final mousterian at grotta di fumane: a report from the 2006-2008 research. quartär, 58, 131-151. peresani m., cremaschi m., ferraro f., falguères ch, bahain j.j., gruppioni g., sibilia e., quarta g., calcagnile l., dolo j.m. (2008) age of the final middle palaeolithic and uluzzian levels at fumane cave, northern italy, using 14c, esr,234u/230th and thermoluminescence methods. journal of archaeological science, 35, 2986-2996. peresani m., cristiani e., romandini m. (2016) the uluzzian technology of grotta di fumane and its implication for reconstructing cultural dynamics in the middle upper palaeolithic transition of western eurasia. journal of human evolution 91, 3656. peresani m., monegato g., ravazzi c., bertola s., margaritora d., breda m., fontana a., fontana f., jankovi� i., karavanic i., komšo d., mozzi p., pini r., furlanetto g., giovanni maria de amicis m., foliate tools from a middle palaeolithic site in italy 27 perho� z., posth c., ronchi l., rossato s., vukosavljevi� n., zerboni a. (2021) huntergatherers across the great adriatic-po region during the last glacial maximum: environmental and cultural dynamics. quaternary international, 581-582, 128-163. peresani m., potì a., visentin d., thun hohenstein u. (2018) at the western end. a discussion on the significance of a mousterian assemblage with leaf points discovered in northern italy. session xvi-1, the variability of bifacial tools in the middle palaeolithic and their importance in the transition to the upper palaeolithic in western eurasia: raw material, techno-typology, chronology and interactions in their environmental and cultural context. xviii congresso uispp, parigi, 26. peresani m., romandini m., duches r., jéquier c., nannini n., pastoors a., picin a., schmidt i., vaquero m., weniger g.c. (2014) new evidence for the mousterian and gravettian at rio secco cave, italy. journal of field archaeology, 39/4, 401-416. peretto, c. (1992) il paleolitico medio, in a.guidi m. (a cura di) piperno: italia preistorica, laterza, 170 197. pini r., ravazzi c., reimer p.j. (2010) the vegetation and climate history of the last glacial cycle in a new pollen record from lake fimon (southern alpine foreland, n-italy). quaternary science reviews, 29, 3115-3137. poli m.e., burrato p., galdini f., zanferrari a. (2008) seismogenic sources responsible for destructive earthquakes in north-eastern italy. bollettino di geofisica teorica ed applicata, 49, 301-313. potts r.b., shipman p. (1981) cut-marks made by stone tools on bones from olduvai gorge, tanzania. nature, 291, 577-80. richter j. (1997) sesselfelsgrotte iii: der g-schichtenkomplex der sesselfelsgrotte zum verständnis des micoquien. quartär-bibliothek, saarbrücken. richter j. (2009) the role of leaf points in the late middle palaeolithic of germany. praehistoria, 10. richter j. (2016) leave at the height of the party: a critical review of the middle paleolithic in western central europe from its beginnings to its rapid decline. quaternary international, 411, 107-128. romandini m., nannini n., tagliacozzo a., peresani m. (2014) the ungulate assemblage from layer a9 at grotta di fumane, italy: a zooarchaeological contribution to the reconstruction of neanderthal ecology. quaternary international, 337, 11-27. romandini m., terlato g., nannini n., tagliacozzo a., benazzi s., peresani m. (2018b) humans and bears a neanderthal tale. reconstructing uncommon behaviors from zooarchaeological evidence in southern europe. journal of archaeological science, 90, 71-91. romandini m., thun hohenstein u., fiore i., tagliacozzo a., perez a., lubrano v., terlato g., peresani m. (2018a) late neandertals and the exploitation of small mammals in northern italy: fortuity, necessity or hunting variability? quaternaire, 29(1), 6167. romandini m., crezzini j., bortolini e., boscato p., boschin f., carrera l., tagliacozzo a., terlato g., arrighi s., badino f., figus c., lugli f., marciani g., oxilia g., moroni a., negrino f., peresani m., riel-salvatore j., ronchitelli a., spinapolice e.e., benazzi s. (2020) macromammal and bird assemblages of late middle to upper palaeolithic transition in italy: an extended zooarchaeological review. quaternary international, 551, 188-223. sauro u. (1973) il paesaggio degli alti lessini: studio geomorfologico. mem. fuori, serie 6, museo di storia naturale di verona, 160. sauro u. (1978) forme strutturali e neotettoniche nei monti lessini. gruppo studio quaternario padano, 4, 31-60. sauro u. (2003) evidenze morfologiche di terremoti recenti nei monti lessini e nel monte baldo. atti e memorie della accademia di agricoltura scienze e lettere di verona, vol. 175, a.a. 1998-1999, 89110. sauro u. (2013) un golfo di pianura insinuato nel rilievo prealpino. in: b. avesani (ed.) valpantena dal vinum raeticum all’amarone. cantina sociale valpantena, gianni bussinelli editore, 4-17. sauro u. (2020) tracce di glaciazioni antiche nei monti lessini. la lessinia ieri oggi domani, 33-44. sauro u., ferrarese f. (2016) montagne in evoluzione e terremoti: alcuni casi nelle prealpi venete, trentine e gardesane. de rerum natura, numero monografico speciale, museo di storia naturale e archeologia montebelluna, 100, isbn 978-889724-104-1. sauro u., zampieri d. (2001) evidences of surface faulting and surface rupture in the fore-alps of veneto and trentino (ne italy). geomorphology, 40, 169-184. scali s., mangiacotti m., bonardi a. (2008) living on the edge: habitat selection of hierophis viridiflavus. acta herpetologica, 3, 85-97. schmid e. (1972) atlas of animal bones for prehistorians, archaeologists and quaternary geologists. london, elsevier. shipman p. (1981) life history of a fossil: an introduction to taphonomy and paleoecology, harvard university press, cambridge. sillero n., oliveira m.a., sousa p., sousa f., gonçalves -seco l. (2014) distributed database system of the new atlas of amphibians and reptiles in europe: the na2re project: amphibia-reptilia 35, 3339. sindaco r., doria g., razzetti e., bernini f. ( 2006) atlante degli anfibi e dei rettili d’italia. atlas of italian amphibians and reptiles. edizioni polistampa. firenze: societas herpetologica italica. szyndlar z. (1984) fossil snakes from poland. acta zoologica cracoviensia, 28, 1-156. szyndlar z. (1991) a review of neogene and quaternary snakes of central and eastern europe. part i: scolecophidia, boidae. colubrinae. estudios geologicos, 47, 103-126. terlato g., livraghi a., romandini m., peresani m. (2019) large bovids on neanderthal menu: ex 28 peresani m. et al. ploitation of bison priscus and bos primigenius in north-eastern italy. journal of archaeological science, 25, 129-143. terlato g., lubrano v., romandini m., marín-arroyo a.b., benazzi s., peresani m. (2021) late neanderthal subsistence strategies at san bernardino cave (berici hills northeastern italy) inferred from zooarchaeological data. alpine and mediterranean quaternary, 34(2), 1-23. thun-hohenstein u., peretto c. (2005) the exploitation of the faunal remains in the mousterian levels at riparo tagliente (verona, italy). in: molines, n., moncel m.h., monnier j.l. (eds), données récents sur les modalités de peuplement et sur le cadre chronostratigraphique. géologique et paléogéographique des industries du paléolithique inferieur et moyen en europe. b.a.r. international series, oxford, 261-268. tostevin g.b., skrdla p. (2006) new excavation at bohunice and the question of the uniqueness of the type-site for the bohunician industrial type. anthropologie xlv/1, 31-48. uthmeier t. (2004) micoquien, aurignacien und gravettien in bayern: eine regionale studie zum übergang vom mittelzum jungpaläolithikum (phd dissertation). habelt, bonn. viganò a., bressan g., ranalli g., martin s. (2008) focal mechanism inversion in the giudicarielessini seismotectonic region (southern alps, italy): insights on tectonic stress and strain. tectonophysics, 460, 106-115. zampieri d. (1995) tertiary extension in the southern trento platform, southern alps, italy. tectonics, 14, 645-657. zampieri d. (2000) segmentation and linkage of the lessini mountains normal faults, southern alps, italy. tectonophysics, 319, 19-34. zanferrari a., bollettinari g., carobene l., carton a., carulli g. b., castaldini d., cavallin a., panizza m., pellegrini g. b., pianetti f., sauro u. (1982) evoluzione neotettonica dell'italia nord-orientale. memorie scienze geologiche, 35, 355-376. zorzi f., pasa a. (1944-1945) il deposito quaternario di villa di quinzano. bullettino di paletnologia italiana, viii (1), 1-52. zilhão j. (2005) burial evidence for social differentiation of age classes in the early upper paleolithic, in: vialou, j., renault-miskowsky, j., patou mathis, m. (dir.), comportements des hommes du paléolithique moyen et supérieur en europe: territoires et milieux. eraul, liège, 231-241. foliate tools from a middle palaeolithic site in italy 29 ms. received: september 1, 2021 revised: december 2, 2021 accepted: december 2, 2021 avaiable online: february 1, 2022 30 sess 2_16022011_tpr3.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 recognizing avulsion events in the adige river alluvial system silvia piovan & paolo mozzi dipartimento di geografia – università di padova, padova corresponding author: s. piovan <silvia.piovan@unipd.it> abstract: piovan s. & mozzi p., recognizing avulsion events in the adige river alluvial system. (it issn 0394-3356, 2011) palaeohydrographical reconstructions of the adige river alluvial system has recently begun to exploit chronostratigraphy and detailed geomorphological analysis focused on the role of major avulsive events. following this research line, this work sums up the state of the art and discusses new data at a comprehensive scale. riassunto: piovan s. & mozzi p., eventi avulsivi nel sistema alluvionale del fiume adige. (it issn 0394-3356, 2011) la ricostruzione della paleoidrografia del sistema fluviale dell’adige ha iniziato a sfruttare, in tempi recenti, analisi geomorfologiche e cronostratigrafiche di dettaglio indirizzate a riconoscere i maggiori eventi avulsivi. seguendo tale linea di ricerca, questo lavoro sintetizza lo stato dell’arte e discute nuovi dati in una scala regionale. key words: adige river, holocene, alluvial plain, avulsion parole chiave: f. adige, olocene, pianura alluvionale, avulsione this work is an attempt to discuss the comprehensive palaeohydrographical reconstructions and stratigraphy of the adige river alluvial system, with a specific focus on the role of avulsive events. the study area ranges from roverchiara-legnago to the venice lagoon and the present coastline (from west to east), and from montagnana-este to rovigo-adria (from north to south). the area is characterized by a dense network of alluvial ridges formed by the adige river and, locally, by the po river through the aggradation of sandy and silty channel deposits, natural levees, and minor, proximal crevasse splays. these evidences suggest that alluvial plain formation has been mainly driven by avulsion, defined as the abandonment of all or part of a channel belt in favor of a new course (allen, 1965), rather than lateral migration of channel belts. this sedimentary process is prevailing in other alluvial settings, such as the rhine-meuse delta (stouthamer & berendsen, 2007) and the saskatchewan river (morozova & smith, 2000). the adige river is the second longest italian river (410 km) and the third in terms of catchment area (12,200 km2). the adige “high plain”, corresponding to the piedmont portion of the adige sedimentary system, is characterized by gravels and a braided river course. downstream, in the “low plain,” the sediments become sandy and silty-clayey and the river turns to a single-channel, meandering type. the adige river reaches the adriatic sea a few kilometers south of the lagoon of venice, through a cuspate delta mouth. the brenta river megafan and the po sedimentary system (murst, 1997; fontana et al., 2008) bound the late holocene adige sedimentary system to the north and to the south, respectively. in the distal portion of the alluvial plain, the boundary between adige and po alluvial systems is not well defined as branches of the po river have occasionally intersected the adige alluvial plain and vice versa. studies on the late holocene geomorphological evolution of the distal tract of the adige alluvial plain started in the 1970s, concurrent with an increase of archaeological surveys and excavations, given the relationship through time between important ancient settlements and the changing of river courses. regional reconstructions of the late holocene paleohydrography, such as those of peretto (1986), marcolongo & zaffanella (1987), mostly relied on remote sensing data. hence, the times of activity of the different branches of the adige river and their relations with the northernmost branches of the po river were largely hypothetical and commonly based only on the interpretation of landforms and their association with surface archaeological remains. detailed geoarchaeological and palaeoenvironmental investigations provided valuable data but were limited to few excavated sites, e.g., ballotta (1993) and balista (2004). seminal work of castiglioni (1978) provided some preliminary indications on the activity of different river branches, later supported by few radiocarbon datings (castiglioni, 1995). recently published works (e.g., amorosi et al., 2008; piovan et al., 2010), as well as ongoing geological surveys 120 122 121 (sheet 147 “monselice”, carg project) provide new detailed geomorphological and stratigraphical data on the distal part of the adige-po alluvial plain, allowing for the definition of the activity of some river branches at regional scale. a digital terrain model based on contour lines with a spacing of 0.5 m derived from “carta tecnica regionale del veneto” (1:5000 scale), combined with aerial photographs and satellite images, allow to recognize the most important alluvial ridges, as shown in figure 1. the montagnana-este adige alluvial ridge, which was active during the bronze age and until late roman times-early middle ages (marcolongo & zaffanella, 1987; balista, 2004), runs from bonavigo to monselice where it splits in a number of minor alluvial ridges. the bagnoli ridge, which runs from pernumia to agna in nw-se direction, is attributed to a roman/ pre-roman adige palaeochannel according to remote sensing and archaeological evidence (marcolongo, 1987). calcimetric analysis (zoletto, 1991) and dendrochronological analysis (castiglioni, 1995) confirm the activity of the adige river around 1164 bc. the conselve ridge runs from pernumia to santa margherita, few kilometres from the inner margin of the lagoon of venice. radiocarbon datings of organic material from manual boreholes in a crosssection through the conselve alluvial ridge date the local activity of the adige river to roman times. the deserto-sant’urbano was apparently active during the 2nd millennium bc, as from some unpublished radiocarbon datings (carg project). no chronological data are available for other alluvial ridges, such as those of pozzonovo and terrassa padovana, which have not yet been studied from a chrono-stratigraphical point of view. in detail, bagnoli and conselve alluvial ridges join the saline-cona ridge (also called “po northernmost branch by castiglioni, 1978) in agna and in concadalbero, respectively. the saline-cona alluvial ridge was formed by a po branch active until final bronze age (about 3000 cal bp) (piovan et al., 2010). it runs from rovigo through san martino di venezze, anguillara veneta, agna and cona to concadalbero. age estimates suggest that adige palaeochannel in bagnoli may have been partly contemporary to the saline-cona po branch. castiglioni (1978), on the basis of p. jobstraibizer’s petrographic analysis of sands, regarded the sands of the saline-cona alluvial ridge in cona, downstream of agna, as belonging to the po river but showing a adige component: this would be consistent with the existence of a junction of the adige and po rivers at agna. around 3000 bp, the po river northernmost branch was no more active (piovan et al., 2010); aggradation continued until roman times due to sedimentation by the adige river from concadalbero to santa margherita. here, according to stratigraphical investigations, the adige river was active during roman times. fig. 1, geomorphological sketch of the adige-po plain. the map shows the main alluvial ridges recognized by dtm (in the background) and remote sensing. the circles indicate the points where the major avulsion occurred. schema geomorfologico della pianura dell’adige-po. la carta mostra i principali dossi alluvionali riconosciuti mediante dtm (sullo sfondo) e telerilevamento. i cerchi indicano i punti in cui sono avvenute le principali avulsioni. recognizing avulsion events in the adige river ... 122 ms. received: testo ricevuto il present-day adige river alluvial ridge runs from bonavigo through legnago, badia polesine, san martino di venezze and pettorazza grimani to cavanella d’adige. it formed after an important avulsion, probably occured in late roman timesmiddle ages in bonavigo (la cucca site), that diverted the course of the adige river from the northern path of montagnana-este (zaffanella, 1979; zerbinati, 2003; balista, 2004). in figure 1 the main avulsive nodes are indicated, from which the different alluvial ridges stem out. future research will be dedicated to developing a more detailed chronostratigraphic framework, with the aim of sorting out the possible allocyclic forcings which may lead to major avulsions, i.e., climate-driven hydrological changes, enhanced sediment yield due to anthropogenic soil erosion in the catchment, relative base level changes. references allen j.r.l. (1965) a review of origin and characteristic of recent alluvial sediments. sedimentology, 5, 89-101. amorosi a., fontana a., antonioli f. , primon s. & bondesan a. (2008) post-lgm sedimentation and holocene shoreline evolution in the nw adriatic coastal area. geoacta, 7, 41-67. balista c. (2004) il territorio cambia idrografia: la rotta della cucca. in: g. leopardi and s. rossi (eds.) archeologia e idrografia del veronese a cent’anni dalla deviazione del fiume guà (1904-2004). atti della giornata di studi “la necropoli del fiume nuovo,” 15 maggio 2004. dipartimento di scienze dell’antichità, saltuarie dal laboratorio del piovego, 6, 55-86. ballotta c. (1993) studio geomorfologico del territorio comunale di villadose. in: e. maragno (ed.) la centuriazione dell’agro di adria. ags edizioni, stanghella, 208-211. castiglioni g.b. (1978) il ramo più settentrionale del po nell’antichità. atti e memorie accademia patavina ss.ll.aa., 90, 157-164. castiglioni g.b. (1995) risultati preliminari del nuovo rilevamento geomorfologico della pianura padana. in: g.b. castiglioni and p.r. federici (eds.) assetto fisico e problemi ambientali delle pianure italiane. atti delle giornate di studio della società geografica italiana, roma, 3-4 giugno 1993. società geografica italiana, roma, 13-72. fontana a., mozzi p. & bondesan a. (2008) alluvial megafans in the venetian-friulian plain (northeastern italy): evidence of sedimentary and erosive phases during late pleistocene and holocene. quaternary international, 189, 71-90. marcolongo b. (1987) ricostruzione paleoidrografica attraverso interpretazione di immagini telerilevate. in: b. marcolongo (eds.) paleoidrografia tardoquaternaria della pianura veneta sudoccidentale e il suo significato in una ricostruzione paleo climatica. c.n.r, padova, 6-9. marcolongo b. & zaffanella g.c. (1987) evoluzione paleogeografica della pianura veneta atesino padana. athesia, 1, 31-67. ministry of university research and technology (murst) (1997) geomorphological map of po plain, 3 sheets, scale 1:250000. s.el.ca, firenze. morozova g.s. & smith n.d. (2000) holocene avulsion styles and sedimentation patterns of the saskatchewan river, cumberland marshes, canada. sedimentary geology, 130, 81-105. peretto r. (1986) ambiente e strutture antropiche nell’antico polesine. in: aa.vv. (eds.) l’antico polesine. testimonianze archeologiche e paleoambientali. antoniana s.p.a., padova, 21-100. piovan s., mozzi p. & stefani c. (2010) bronze age palaeohydrography of the southern venetian plain. geoarcheology, 25 (1), 6-35. stouthamer e. & berendsen h.j.a. (2007) avulsion: the relative roles of autogenic and allogenic process. sed. geol., 198, 309-325. zaffanella g.c. (1979) geomorfologia e archeologia preistorica nel territorio compreso tra l’adige, i colli berici e i colli euganei. padusa, 15(1-2-3-4), 109-147. zerbinati e. (2003) i tre silvestri. in: accademia dei concordi (ed.) camillo, carlo e girolamo silvestri. successi delle acque dall’anno 1677 al 1755. s.i.t., treviso, xxi-xlv. zoletto r. (1991) geomorfologia ed analisi dei sedimenti sabbiosi nella pianura della “bassa padovana” ad est di monselice. unpublished master’s thesis, university of padova, italy. s. piovan & p. mozzi january 15, 2011 15 gennaio 2011 sess 0_retro e indice edi.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 the pleistocene calcareous tufa of santa sabina (perugia, central italy): stratigraphy, palynology and vertebrate paleontology fausto pazzaglia 1, massimiliano r. barchi 1, nicoletta buratti1, marco cherin1 & marianna ricci2 1 dipartimento di scienze della terra, università degli studi di perugia 2 dipartimento di scienze della terra, università degli studi di firenze corresponding author: f. pazzaglia <fpazzagl@unipg.it> abstract: pazzaglia f. et al., the pleistocene calcareous tufa of santa sabina (perugia, central italy): stratigraphy, palynology and vertebrate paleontology. (it issn 0394-3356, 2011) an integrated sedimentological, geochronological, paleontological (mammal fauna) and palynological study was carried out on the calcareous tufa of santa sabina, outcropping in the ellera basin (perugia, central italy). previous u/th datings on the investigated sections provided an absolute age of 115±8 ka as confirmed by the vertebrate fauna which could be biochronologically referred to the early-middle aurelian mammal age. it corresponds to the mis 5e, and to the last interglacial period (eemian) characterised by wet and warm climate conditions suitable for calcareous tufa depositon. riassunto: pazzaglia f. et al., i “calcareous tufa” pleistocenici di santa sabina (perugia, italia centrale): stratigrafia, palinologia e paleontologia a vertebrati. (it issn 0394-3356, 2011) lo studio integrato sedimentologico, geocronologico, paleontologico (fauna a vertebrati) e palinologico dei calcareous tufa di santa sabina, affioranti nella zona ad ovest di perugia (italia centrale, ha messo in evidenza la presenza di una mammalofauna riferibile all’aureliano inferiore-medio. questo è in accordo con quanto precedentemente indicato dalle datazioni u/th, che hanno restituito un’età assoluta di 115±8 ka per le sezioni studiate. questo intervallo di tempo corrisponde all’intervallo isotopico mis 5e e all’ultimo interglaciale (eemiano), caratterizzato da condizioni climatiche caldoumide, ideali per la deposizione dei calcareous tufa. key words: pleistocene, calcareous tufa, santa sabina, mammal fauna, palynology parole chiave: pleistocene, calcareous tufa, santa sabina,mammalofauna, palinologia among terrestrial carbonates (calcareous tufa, speleothem and travertines), calcareous tufa represent good proxy-indicator of environmental changes. they can be successfully approached by integrated analyses because of their multiple reliable geochemical records. a multidisciplinary investigation was carried out on the calcaerous tufa outcropping in the ellera basin area, located immediately west of perugia (central italy). the stratigraphical study and sedimentary facies analysis throughout two key sections (ssab2 and chiusa section) was combined with preliminary paleontological (fossil mammals) and palynological data. these data were compared with radiometric analyses carried out on ssab2 section (pazzaglia, 2008), in order to obtain a detailed paleoecological and chronological framework. the ellera basin is a little basin bordered to the north and north-east by mesozoic carbonate mountains, to the west by miocene flysch hills and to the south by pleistocene continental hills. it consists of a semigraben with a eastern master-fault dipping towards west and probably antithetic western minor faults. the thickness of sediments (calcareous tufas, silts, clays, sands and rare gravels) that have filled the basin is greater than 140 m. two units separated by erosional surfaces can be observed: the santa sabina unit and the san biagio unit. the first 22-30 m thick unit covers an area of 10 km2 and its surface appears flat, with an elevation higher in the center. the santa sabina unit shows two lithofacies: pgu4a (calcareous tufa) and pgu4b (clays, silts, peats and calcareous tufa) (pazzaglia, 2008). this study is focused on the characterisation of the calcareous tufa lithofacies which outcrop in the more proximal part of the santa sabina unit, with respect to the mesozoic ridge, where possible caco3-enriched water springs could be presumably located. from bottom to top the ssab2 section is characterised by the presence of a basal calcareoussiliciclastic sand level with rare lithoclasts and organic laminations (40 cm thick). at the top of the sandy level there is a centimetric calcareous crust, followed by a 110 cm thick level mainly consisting of coherent micritic tufa with phytohermal clusters/ tufts and lenticular accumulations of phytoclasts. the section is closed by centimetric strata of microhermal and phytoclastic tufa (40 cm thick) (fig. 1). u/th datings on the ssab2 sections provided an absolute age of 115±8 ka (pazzaglia, 2008). the chiusa section is characterised by the absence of microhermal facies and by the predominance of decimetric to metric strata of micritic and phytoclastic tufa. the total thickness of the section is about 10 m. 161 163 162 in the pgu4a phytohermal tufas, previous paleontological data (principii, 1930) have revealed the presence of leaves and stems of poaceae (arundo sp., phragmites sp.) and cyperaceae (carex?). in the micritic tufa abundant lacustrine molluscs (principi, 1930), ostracods and oogons of characeae have been found (pazzaglia, 2008). some of the sedimentological data recorded from ssab2 section reveal a partial fluvial origin of the deposits (i.e. siliciclastics inputs, presence of microhermal facies, current structures). these evidences are absent in the chiusa section. so, the facies association of the examined sections suggests a gradual passage from fluvio-palustrine to fully palustrine conditions from north (ssab2 section) to south (chiusa section), as the distance from the mesozoic carbonate ridge increases. fossil vertebrate finds from pleistocene travertine s.l. deposits are rare in europe. the most important site is weimar-ehringsdorf (germany), that has provided a diverse vertebrate collection, including fish, amphibians, reptiles, birds and mammals (schäfer et al., 2007). the first report about the presence of mammalian fossils from the “travertines” near the village of ellera was written by bonarelli (1900), who generically cited “hippopotamus remains”. later, principi (1930) published a more complete description of the “travertine” outcrops near ellera, where he listed and synthetically described the mammals. principi’s collection from ellera was long reported missing, but it was recently found again in the warehouse of the “soprintendenza per i beni archeologici per l’umbria”. the mammal fauna from ellera was collected at the beginning of the 20th century. unknown is the stratigraphic origin of the fossils: principi (1930) wrote that they became from “travertine” near “rosci’s house”, a farm still there, near chiusa section. the type of carbonatic encrustations on the fossil bones are comparable with the facies outcropping at chiusa section. because of the high rate of sedimentation of the calcareous tufa (i.e. pentecost & whitton, 2000), it could be reasonably supposed that the mammal remains form a chronologically homogeneous assemblage. the collection is poor in terms of quantity of fossil material, but it is characterised by a quite abundant paleodiversity. the most represented taxon is bos primigenius. four isolated molar teeth (two lower and two upper), a left astragalus, the distal end of a metacarpal, the proximal end of a radius, the proximal end of a femur, and lots of other fragments were identified. elephas antiquus is represented by fragments of molar teeth and tusks. the tip of a little tusk is still partially embedded in a block of very compact tufa. the distal end of a tibia belongs to a medium size cervid and is morfig. 1, ssab2 section, with indication of the 8 samples taken for palynological analysis. sezione ssab2, con indicazione degli 8 campioni raccolti per le analisi palinologiche. f. pazzaglia et al. 163 ms. received: testo ricevuto il phometrically compatible with cervus sp.. four lateral teeth (p4, m1, m2, m3) can be rather related to a smaller, dama-like form. cervidae are also represented by a dorsal vertebral centrum, lacking of the anterior and posterior epiphysis, thus referred to a young animal. other artiodactyla remains are a right m2 of sus scrofa and some teeth fragments of hippopotamus sp.. perissodactyla are represented by a tooth fragment and an astragalus of stephanorhinus sp.; further analysis of the latter bone will probably allow to determine the rhinoceros species. the only remain belonging to a carnivore is a left p4 of ursus spelaeus. the mammal fauna is typical of a forested landscape on the whole, with the presence of quite large palustrine and/or lacustrine habitats (because of the occurrence of hippopotamus sp.) as revealed by sedimentological inferences, and other paleontological data (plants, molluscs, and ostracods). although palynological processing of carbonates is still generally discouraged because considered as unfavourable lithotypes, some literature reveals that calcareous tufa could be palynologically productive and often suitable for pollen analysis (i.e. burjachs & julià, 1994; vermoere et al., 1999). a palynological investigation was carried out on 8 samples taken from the ssab2 section (fig. 1). the section was sampled with a variable interval (max. 60 cm) from both micritic and phytohermal facies. standard chemical and physical treatments were employed to remove most of the mineral sediment and to concentrate pollen grains in the residue. pollen analyses are in progress to define vegetational and climatic conditions during carbonate deposition. although most of the fossil material from ellera is fragmentary and some of the specimens have not been thoroughly examined yet, the finds allowed to infer some biochronological and paleoecological conclusions. the mammal collection could be biochronologically referred to the early-middle aurelian mammal age, as previously suggested by a radiometric dating (115±8 ka, pazzaglia, 2008). this age corresponds to the mis 5e, and to the last interglacial period (eemian) characterised by wet and warm climate conditions suitable for calcareous tufa depositon (baker et al., 1993; soligo et al., 2002; martin-algarra et al., 2003). the integrated stratigraphical, sedimentological, paleontological (mammalian fauna), and palynological analyses, carried out in this study, could allow to better define the depositional and climatic conditions controlling the deposition of the santa sabina calcareous tufa. references baker a., smart p.l. & ford d.c. (1993) northwest european palaeoclimate as indicated by growth frequency variations of secondary calcite deposits. palaeogeog., palaeoclim., palaeoecol., 100, 291-300. bonarelli g. (1900) descrizione geologica dell’umbria centrale. camera di commercio di perugia, ed. postupostuma 1967. burjachs f. & julià r. (1994) abrupt climatic changes during the last glaciation based on pollen analysis of the abric romani, catatonia, spain. quaternary research, 42, 308-315. martin-algarra a., martin-martin m., andreo b., julià r. & gonzales-gomez c. (2003) sedimentary patterns in perched spring travertines near granada (spain) as indicators of the paleohydrological and paleoclimatological evolution of a karst massif. sed. geol., 161, 217-228. pazzaglia f. (2008) evoluzione tettonico-sedimentaria dei bacini quaternari minori tra la val di chiana e il bacino tiberino. unpublished phd thesis. pentecost a. & whitton b.a. (2000) limestone. in: whitton b.a. & potts m. (eds). the ecology of cynobacteria. 257-279, kluwer academic publisher, netherland. principi p. (1930) alcune osservazioni intorno all’età dei travertini di ellera nei dintorni di perugia. atti r. acc. naz. lincei, s. 6, 11, 493-495. schäfer d., heinrich w.d., böhme g. & steiner w. (2007) aspects of the geology, palaeontology and archaeology of the travertine site of weimarehringsdorf (thuringia, central germany). cour. forsch.-inst. senckenberg, 259, 141-147. soligo m., tuccimei p., barbieri r., delitalia m.c., miccadei e. & taddeucci a. (2002) u/th dating of freshwater travertine from middle velino valley (central italy): paleoclimatic and geological implications. palaeogeogr., palaeoclim., palaeoecol., 184, 147-161. vermoere m., degrysen p., vanhecke l., muchez p., paulissen e., smets e. & waelkens m. (1999) pollen analysis of two travertine sections in baskoy (southwestern turkey): implications for environmental conditions during the early holocene. rev. palaeobot. palyn., 105, 93-110. the pleistocene calcareous tufa of santa sabina ... january 15, 2011 15 gennaio 2011 that is distinct from those of the holocene epoch. among scientists dealing with the anthropocene, only earth sciences researchers and earth systems scientists have the cultural and technical tools to be aware of the exceptionality of the times we are living in within the human enterprise, but also within geologic time spanning tens of millions of years. consequently, they have a responsibility to inform policymakers and the public about the risks young people will face in near future, and the formalization of the anthropocene represents an extraordinary opportunity in this respect, that has been missed for now. 2. the proposal when introducing the term anthropocene, crutzen & stoermer (2000) and crutzen (2002), proposed the beginning of the industrial revolution in europe, with the introduction of watt-boulton’s steam engine (1788). this technological breakthrough led to changes in greenhouse gas concentrations in the atmosphere through increased burning of coal, later accompanied by oil and natural gas. the resulting geological effects were gradual and varied in time and space, with no single clear isochronous signal in the geological record. however, the formalization of a new unit must respect the strict rules of the international stratigraphic guide published by the international subcommission on stratigraphic classification (issc), a constituent body of the ics operating within the iugs. a precise global start date in the international geologic time scale (gts) and a correlative global boundary stratotype section and available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 38 (2), 2025, 111-117 https://doi.org/10.26382/amq.2025.06 1. introduction in march 2024, the proposal of the international anthropocene working group (awg), founded in 2009 within the subcommission on quaternary stratigraphy (sqs) to study the suitability of the anthropocene to be promoted to a formal chronostratigraphic unit of the geological timescale, was refused by international commission on stratigraphy (ics) and the international union of geological sciences (iugs). the statement reads: “despite its rejection as a formal unit of the geologic time scale, the anthropocene will nevertheless continue to be used not only by earth and environmental scientists, but also by social scientists, politicians and economists, as well as by the public at large. it will remain an invaluable descriptor of human impact on the earth system” (iugs, 2024). one of the main obstacles to the acceptance of the anthropocene as a new epoch is the short duration (ca 72 years) of the time interval from the year 1952 ce, which the awg choose as the beginning of the anthropocene. however, the anthropocene concept of the iugs is different from the “epoch” concept proposed by crutzen & stoermer (2000) and crutzen (2002). the anthropocene “event” of those in opposition to the “epoch” relegates the importance of the post-mid-20th transformation to simply the latest of many phases of human influence on the earth, which dates back to the pleistocene, at least 50,000 years ago. the awg has provided an enormous amount of data to support the anthropocene as a chronostratigraphic unit, with a clear signature in sediments and ice the responsibility of geologists in defining the anthropocene dario zampieri senior scholar at the “studium patavinum” of università degli studi di padova, padova, italy. corresponding author: dario zampieri <dario.zampieri@unipd.it> abstract: the subcommission on quaternary stratigraphy (sqs), a constituent body of the international commission on stratigraphy (ics), established the anthropocene working group (awg) in 2009 to examine the anthropocene as a potential new formal division of the geological time scale (gts). in october 2023 the awg submitted the formal proposal to ics, which in march 2024 rejected the proposal. among the humanities and earth system scientists, only the geologists, more than anyone else, have the cultural and technical tools to be aware of the exceptionality of today’s times and to place them in deep time context. for example, dealing with one of the main threats, the climate crisis, few are aware that the speed and scale of anthropogenic release rate of the co2 are unprecedented during the cenozoic (last 66 ma). the rejection of anthropocene formalization hinders the communication, to the public and to policymakers, of the exceptionality of what physically the anthropocene is, and of the related catastrophic risks to human civilization. geologists have a responsibility to inform society about the risks young people will face in the near future, and formalization of the anthropocene represents an extraordinary opportunity in this respect, that has been missed for now. . keywords: anthropocene, climate crisis, tipping points, geologic analogues, geoethics. point (gssp, often called a “golden spike”), which is used to calibrate the stratigraphical record, are needed. afterwards, the community of earth system science (ess) researchers identified an array of global and near-synchronous signals at ~1950 ce, reflecting abrupt changes of socio-economic factors and biophysical processes. this process, termed the “great acceleration”, was coincident with, and driven by, unprecedented increases in population, energy consumption, industrialisation, pollution and globalisation following the end of world war ii (steffen et al., 2015a). between 2020 and 2023, 12 research teams formulated proposals for candidate gssps and other reference sections in eight distinct geological environments that cover five continents to define the base of the anthropocene as a series within the gts (waters et al., 2023). among the 12 candidates, the awg chose as golden spike a level that separates the summer and autumn sediment layers laid down in 1952 within varved sediments in crawford lake, a small meromictic lake occupying a sinkhole in silurian dolomitic limestones of ontario, canada. there, the primary marker shows a rapid increase in 239+240pu radionuclide concentrations from aboveground nuclear detonations, a signal clearly seen in many of the proposed sites, and tens of secondary markers have been identified (mccarthy et al., 2023, 2025). the efforts made by awg to respect the rules imposed by the issc, as testified by an enormous corpus of publications (e.g. zalasiewicz et al., 2019; head et al., 2023a, 2023b; waters et al., 2024) by now the term anthropocene had been cited in over 145,000 documents [(over 15,000 limiting the research to “article title, abstract, keywords” (https://www.scopus.com/)] have so far proved useless, and formalisation of the anthropocene must wait another submission in coming years. in my view, the geologists have missed a great opportunity to master what is within their own competence, delegating to the social and economic disciplines the mastering of the anthropocene concept. in doing so, they hinder the communication to the public and the policymakers of the exceptionality of what the anthropocene is physically, and of the attendant multiple crises with related catastrophic risks for human civilization. 3. the exceptionality of the anthropocene starting with the 20th century, the use of a cheap and high-power density energy oil has produced an abrupt planetary change forced by the cumulative and overwhelming impacts of human activities. the immense instantaneous power offered by managing fossil fuels has been compared by hansen (2009) to the bargain with mephistopheles, who offered faustus his present desire (i.e. power) at the cost of future detriment (i.e. climate disruption). fossil fuels raised living standards in much of the world, by replacing the labour of humans and domestic animals. globally, the world we inhabit is built and powered to the level of 87% by fossil fuels (energy institute, 2025), and some of their industrial uses are difficult to replace. analysis of the past evolution of energy sources allows us to infer that the substitution of fossil fuels by renewables may require several generations (smil, 2017). since energy demands are increasing, renewables are presently supplementing fossil fuels rather than replacing them, supporting fressoz's thesis (fressoz, 2025) that there has never been a transition between energy systems in the past, but rather that different forms of energy are symbiotic. consequently, climate breakdown and unprecedented biodiversity loss and the dispersal of novel entities (new substances, new forms of existing substances and modified life forms not previously known to the earth system) to the environment put humanity at grave risk, and threaten human lives, livelihoods and wellbeing worldwide. using the comparatively stable interglacial holocene as the baseline, nine biophysical systems and processes that are critical for maintaining the stability and resilience of the earth system have been recognized (rockström et al., 2009; steffen et al., 2015b). seven of nine planetary boundaries are now assessed as having been crossed, namely for biosphere integrity, climate change, land use, interference with biogeochemical cycles of nitrogen and phosphorus, novel entities, freshwater change and lastly ocean acidification (persson et al., 2022; wang-erlandsson et al., 2022; richardson et al., 2023; stenzel et al., 2025; kitzmann et al., 2025). the two remaining planetary boundaries that are not transgressed are stratospheric ozone depletion and the increase in atmospheric aerosol loading. many components of the great acceleration and planetary boundaries concepts can be analysed as regards their stratigraphic representation, since the anthropocene emerged from ess, but geologists have been able to assess the signals of the present environmental changes captured by sedimentary strata (e.g. zalasiewicz et al., 2017). 4. tipping points earth system ‘tipping points’ are critical thresholds when environmental stresses become so severe that large parts of the natural world are unable to maintain their current state, leading to abrupt and/or irreversible changes (e.g. marten, 2005; lenton et al., 2008). twenty-six earth system tipping points have been identified from evidence of past changes, observational records and computer models: six in the cryosphere, sixteen in the biosphere, and four in atmospheric and oceanic circulation (lenton et al., 2019, 2023, 2025). global warming is rapidly approaching levels that could trigger individual tipping points in systems that can interact with and destabilise other tipping systems, making tipping cascades possible. as warming approaches and surpasses 2°c this may cause tipping points, once considered low-likelihood, to rapidly become much higher-likelihood events (abrams et al., 2023). lenton et al. (2023) identified five major tipping systems that are already at risk of crossing tipping points at the present level of global warming: the greenland and west antarctic ice sheets, warm-water coral reefs, north atlantic subpolar gyre circulation, and permafrost regions. however, considering the “committed warming” due to thermal inertia of the oceans, which take up ca. 90% of the earth’s energy imbalance (von schuckmann et al., 2023), global warming continues to rise for long periods after a given increase. recently, lee et al. (2025) carried out simulations showing that human-induced perturbations will persist well beyond 2100 for several centuries. abrams et al. (2023) have investigated the commit 112 zampieri d. https://www.scopus.com/ (pagani et al., 2005). high-frequency changes in climate have been driven by periodic oscillations in earth’s orbital parameters of eccentricity, obliquity, and precession that affect the distribution and amount of incident solar energy. by contrast, gradual changes in earth’s major boundary conditions were controlled by plate tectonics, with north atlantic rift volcanism, opening of the tasmanian and drake antarctic gateways, collision of india with asia and subsequent uplift of the himalayas and tibetan plateau, and the uplift of panama and closure of the central american seaway. in the cenozoic time interval, a prominent climatic aberration is the paleocene-eocene thermal maximum (petm), which occurred at ca. 56 ma near the paleocene/eocene (p/e) boundary, accompanied by a major perturbation in the global carbon cycle as inferred from carbon isotope data. more than 10,000 petagrams of isotopically heavy carbon were released from volcanism associated with the north atlantic igneous province (gutjiar et al., 2017). sea surface temperatures as constrained by planktonic isotope records increased by as much as 8°c at high latitudes in less than 10 ka. the carbon release to the atmosphere occurred at a rate of 0.6-1.1 pg c a-1, the record high during the past 66 million years. the initial carbon release during the petm onset occurred over 4,000 to 6,000 years (zeebe et al., 2016; li et al., 2022). presently, anthropogenic carbon release rates are ca. 11 pg c a-1, one order of magnitude higher than inferred for the petm. therefore, the anthropogenic release rate is unprecedented during the cenozoic, and this represents a fundamental challenge to constraining future climate projections. climate simulations performed by earth system models have shown that under very high greenhouse gas (ghg) emissions scenario, the eocene emerges as the most likely analogue, accelerating after 2050 and representing the future climate by 2140 ce. an eocenelike climate emergence would suggest that the unmitigated warming of the rcp8.5 scenario is approximately equivalent to reversing a 50-ma cooling trend in two centuries (burke et al., 2018). under the rcp4.5 scenario, characterized by moderate emissions mitigation, the pliocene emerges as the most common best analogue and climate stabilizes at pliocene-like conditions by 2040 ce. pliocene-like and eocene-like climates emerge first in continental interiors and then expand outwards (burke et al., 2018). in the ipcc sixth assessment report (ar6) (ipcc, 2021) the rcp scenarios have been substituted by a new range of scenarios based on shared socioeconomic pathways (ssps; o’neill et al., 2016). the set of ssps recognizes that global radiative forcing levels can be achieved by different pathways of co2, nonco2 greenhouse gases, aerosols and land use; the set of ssps therefore establishes a matrix of global forcing levels and socio-economic narratives (ipcc, 2021). since the rcps are labelled by the level of radiative forcing they reach in 2100, they can in principle be related to the ssps scenarios. in this sense, the rcp4.5 roughly corresponds to middle-of-the-road ssp2-4.5 (ipcc, 2021, fig. 1.28), but they are not directly comparable. although in ar6, the high-end scenarios rcp8.5 or ssp5-8.5 have been argued to be implausible to unfold, these low-likelihood but high-impact scenarios must be considered, given the stake. the mid-pliocene (3.3-3.0 my), also known as the ted warming associated with the co2 equivalent (co2-e) for each year for three emission scenarios. the results are that the best-estimate threshold will be passed for one, two, and six climate tipping points by the end of the century for the “pre-commitment transient phase” under rcp2.6. rcp4.5, and rcp8.5 scenarios, respectively [rcp2.6 is a strong mitigation scenario in which radiative forcing peaks at approximately 2.6 w/m2 before 2100 and then slowly declines; rcp 4.5 is the intermediate stabilization pathways with 4.5 w/m2 radiative forcing stabilized after 2100; rcp8.5 is the high emissions pathway for which radiative forcing reaches >8.5 w/m2 by 2100 (fifth assessment report (ar5) from ipcc, 2013)]. but, during the subsequent “commitment transient phase”, extra warming will increase the risk of triggering climate tipping points, pushing mean temperatures into the possible tipping threshold range for five, six, and nine climate tipping points under rcp2.6. rcp4.5, and rcp8.5, respectively. under rcp4.5, the scenario that best matches current national commitments, the gap between committed equilibrium warming and pre-commitment transient temperatures is estimated to be 1.2°c in 2100 (abrams et al., 2023). randers & goluke (2020) have modelled the development of the global climate system from 1850 to 2500 under different assumptions about the emission of human ghgs, finding that a point-of-no return is already behind us. the self-sustained melting of the permafrost caused by methane release, lower surface albedo caused by arctic marine ice melting, and higher atmospheric humidity would be triggered by just +0.5°c above the pre-industrial level. in any case, an increase of the global temperature of 1.5°c as desired by the paris agreement and already reached by now would not be “safe” (e.g. möller et al., 2024). this level of warning, including the scientific uncertainty about how close we might be to a tipping point, would require climate governance based on principles of international law, such as precaution, equity and justice, as well as care for future generations. short-term decisions can have severe, even catastrophic, consequences over extremely long-time horizons, potentially affecting life on earth for several millennia, and future generations’ chances for survival and wellbeing (lenton et al., 2023, 2025). 5. the cenozoic analogues of the nine planetary boundaries, climate change is of special interest to the earth scientists, since the shift from holocene stable conditions during which settled civilization developed could make the planet ungovernable. the planetary boundary for atmospheric co2 concentration is set at 350 ppmv and for radiative forcing at 1 wm-2 (richardson et al., 2023). currently, the atmospheric co2 concentration is ca. 425 ppmv (https:// scrippsco2.ucsd.edu/) and the estimated total anthropogenic effective radiative forcing is 2.91 wm-2 [2022 estimate, relative to 1750 (forster et al., 2023)]. geologic analogues from past climate events are invaluable in understanding the impact of massive carbon release on the earth system. since 66 ma, the cenozoic era, earth’s climate system has experienced continuous changes, but the global climate trend has been one of cooling (zachos et al., 2001), while atmospheric co2 concentrations have declined overall 113 the responsibility of geologists in defining the anthropocene. piacenzian warm period, remains the best palaeoclimate for understanding the workings of the earth system at ca. 400 ppmv (360-420 ppmv) concentrations of co2 (burke et al., 2018; ipcc, 2021). therefore, the pliocene is the most appropriate analogue at 400 ppmv, since today we are at ca. 425 ppmv, although the ongoing increase in atmospheric co2 concentration makes the miocene climatic optimum (ca. 16.9-14.7 my, ca. 400-600 ppmv of co2) a strong candidate to serve as a future climate analogue (steinthorsdottir et al., 2021). in the mid-pliocene, mean annual surface temperatures were approximately 1.8 °c to 3.6 °c higher than preindustrial temperatures, the ice sheet extents were reduced, and sea level was about 16 m higher than today (burke et al., 2018; dumitru et al., 2019). the ar6 sets as very likely (90-100% probability) a global mean sea level (gmsl) 5-25 m higher than today and temperatures 2.5°c-4°c warmer (ipcc, 2021). therefore, sea level and temperature rises are both committed, unless implausibly large volcanic eruptions injecting aerosols into earth’s stratosphere will last for decades. 6. discussion the main criticisms to the proposal of the anthropocene as formal unit in the gts is that 72 years is too short to recognize an epoch, and that the future is not geologic time. apart the identification of a potential gssp at the crawford lake, time is precisely the variable that makes the formalization of the anthropocene an urgent and invaluable issue. the global changes of the earth system produced by homo sapiens though mainly by western societies in less than a century are so profound that they pose some of the gravest threats faced by humanity. for example, dealing with one of the main threats, the climate crisis, the anthropogenic release rate of the co2 is unprecedented during the cenozoic (last 66 ma). such an exceptional event may be fully understood in its planetary context only by earth scientists. during the phanerozoic (last 538 ma) our planet has suffered five main extinction episodes, and several minor extinctions, always accompanied by climate crises, fostering the evolution of living organisms including our species. however, the rise of what we call civilization benefitted from the stable conditions of the midholocene (the last 103 years), when climate and global mean sea level remained nearly constant. therefore, what is presently at risk is human civilisation, not the life itself or the planet. regarding the criticism regarding the inherently future scope of the anthropocene, it must be remembered that although the anthropocene is, so far, of extremely short duration, the anthropocene changes are already affecting the sedimentological and stratigraphic record, leaving a distinctively transformed fossil record that will persist long into the future. the climate system is already a mayor element of the proposed new epoch, and future projection is a standard part of science (summerhayes et al., 2024). the long timescale of the temperature responses to anthropogenic forcing, with the committed warming in the pipeline, is a consequence of the ocean’s great thermal inertia (hansen et al., 2023). the climate system’s slow response allows the possibility to avoid the “point of no return”. the delayed response provides humanity time to mitigate the anthropogenic climate forcing so that the equilibrium warming or even the 100-year warming, the time in which 60% of the equilibrium warming is achieved may never occur (hansen et al., 2025). however, the time for action is now, not tomorrow. among natural scientists, earth scientists and particularly geologists are the only ones who have constant awareness of the deep time dimension. not surprisingly therefore, the setting of global standards for expressing the history of the earth by means of the units (periods, epochs and age) of the gts is the responsibility of geologists. but, after all, the geological division of time is a human construction subjected to continuous refinements. in the recent past, geologists did not disdain to strongly quarrel over the gts, the last time about the use of the name quaternary (kerr, 2008). the designation of the holocene epoch itself may be questioned, since it is based on a climatic definition, being just one more interglacial period in a long series started 2.6 ma ago (lewis & maslin, 2015). however, the anthropocene is not only an academic issue, because its consequences are an existential threat to civilization and the designation of the anthropocene in general as an “invaluable descriptor of human impact on the earth system” (iugs, 2024) confuses the specific meaning of the anthropocene as proposed by crutzen and worked on by the awg. 7. conclusions the decision to reject the formalization of the anthropocene, which must await a re-submission, has temporally delegated to social and humanity scientists the managing of this concept. in this way, its link to the dimension of deep time, the prerogative of the geologists, is likely to be lost, along with the challenge of systemic risk governance. the long delay of climate in achieving its equilibrium response is both a curse and a blessing, because a great amount of future warming may be built up before actions required to stem climate change are undertaken. in addition, scientific uncertainty about how close we might be to a tipping point should be reason for urgent action, not delay. the full assumption of responsibility allowed by formalization of the anthropocene by geologists would have greatly informed policymakers of the critical moment we are living through in human history. the ethical obligation of modern geoscientists includes the transfer of knowledge to society, not only to the scientific community (bobrowsky et al., 2018). the extremely high stakes involved place a major burden of responsibility on the present generations and dramatically elevate the need for a precautionary approach, also to avoid intergenerational injustice towards young people and their descendants. the nature of the threats presented by tipping dynamics in the earth system challenges the common linear logic of decision-making in global governance. short-term decisions, that is actions and inaction over the next 10 years, can have ripple effects over millennia. policymakers must consider their responsibility for future impacts that only they can prevent, but they must urgently be informed and pressed by geologists. it is desirable that the sqs and/or the ics review the anthropocene soon. 114 zampieri d. gutjahr m., ridgwell a., sexton p., anagnostou e., pearson p.n., pälike h., norris r.d., thomas e., foster g.l. (2017) very large release of mostly volcanic carbon during the palaeocene-eocene thermal maximum. nature, 548, 573-577. doi: 10.1038/nature23646 hansen j. (2009) storms of my grandchildren. the truth about the coming climate catastrophe and our last chance to save humanity. new york, bloomsbury, pp. 336. hansen j.e., sato m., simons l., nazarenko l.s., von schuckmann k., loeb n.g., osman m.b., jin q., tselioudis g., jeong e., lacis a., ruedy r., russell g., cao j., li j. (2023) global warming in the pipeline. oxford open clim. chang., 3 (1). doi: 10.1093/oxfclm/kgad008 hansen j.e., kharecha p., sato m., tselioudis g., kelly j., bauer s.e., ruedy r., jeong e., jin q., rignot e., velicogna i., schoeberl m.r., von schuckmann k., amponsem j., cao j., keskinen a., li j., pokela a. (2025) global warming has accelerated: are the united nations and the public wellinformed? environment: science and policy for sustainable development, 67, 1, 6-44. doi: 10.1080/00139157.2025.2434494 head m.j., waters c.n., zalasiewicz j.a., barnosky a.d., turner s.d., cearreta a., leinfelder r., mccarthy f.m.g., richter, de b d., rose n.l., saito y., vidas d., wagreich m., han y., summerhayes c.p., williams m., zinke j. (2023a) the anthropocene as an epoch is distinct from all other concepts known by this term. journal of quaternary science, 38(4), 455-458. doi: 10.1002/jqs.3513 head m.j., zalasiewicz j.a., waters c.n., turner s.d., williams m., barnosky a.d., steffen w., wagreich m., haff p.k., syvitski j., leinfelder r., mccarthy f.m.g., rose n.l., wing s.l., an z., cearreta a., cundy a.b., fairchild i.j., han y., ivar do sul j.a., jeandel c., mcneill j.r., summerhayes c.p. (2023b) the anthropocene is a prospective epoch/series, not a geological event. episodes, 46 (2), 229-238. doi: 10.18814/epiiugs/2022/022025 kerr r.a. (2008) a time war over the period in which we live. science, 319, 402-403. doi: 10.1126/science.319.5862.402 kitzmann n.h., caesar l., sakschewski b., rockström j. (eds.) (2025) planetary health check 2025, a scientific assessment of the state of the planet. potsdam institute for climate impact research (pik), potsdam, germany. www.planetaryhealthcheck.org/ ipcc (2013) climate change 2013: the physical science basis. contribution of working group i to the fifth assessment report of the intergovernmental panel on climate change [stocker t.f., qin d., plattner g.-k., plattner g.-k., tignor m., allen s.k., boschung j., nauels a., xia y., bex v., midgley p.m. (eds.)]. cambridge university press, cambridge, united kingdom and new york, ny, usa, pp. 1535. www.cambridge.org/9781107661820 ipcc (2021) climate change 2021: the physical science basis. contribution of working group i to the sixth assessment report of the intergovernmental panel on climate change [masson-delmotte v., acknowledgements i thank giovanni monegato for discussions on the anthropocene that have continued for several years. i’m also grateful to michael wagreich and jan zalasiewicz for their suggestions that enriched the previous version of this text. declaration of competing interest the author declare that he has no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. data availability no data was used for the research described in the article. references abrams j.f., huntingford c., williamson m.s., armstrong mckay d.i., boulton c.a., buxton j.e., sakschewski b., loriani s., zimm c., winkelmann r., lenton t.m. (2023) committed global warming risks triggering multiple climate tipping points. earth's future, 11, e2022ef003250. doi: 10.1029/2022ef003250 bobrowsky p., cronin v.s., di capua g., kieffer s.w., peppoloni s. (2018) in gundersen l.c. (ed.) scientific integrity and ethics in the geosciences, agu special publications, 73, 175-212. burke k.d., williams j.w., chandler m.a., haywood a.m., lunt d.j., otto-bliesner b.l. (2018) pliocene and eocene provide best analogs for nearfuture climates. pnas, 115, 52, 13288-13293. doi: 10.1073/pnas.1809600115 crutzen p.j. (2002) the geology of mankind. geology, 415, 23. doi: 10.1038/415023a crutzen p.j., stoermer e.f. (2000) anthropocene. igbp global change newsletter, 41, 17-18. dumitru o.a., austermann j., polyak v.j., fornós j., asmerom y., ginés j., onac b.p. (2019) constraints on global mean sea level during pliocene warmth. nature, 574, 233-236. doi: 10.1038/s41586-019-1543-2 energy institute (2025) statistical review of world energy. 74th edition, pp. 76. www.energyinst.org/statistical-review forster p.m., smith c.j., walsh t., lamb w.f, lamboll r., hauser m., ribes a., rosen d., gillett n., palmer m.d., rogelj j., von schuckmann k., seneviratne s.i., trewin b., zhang x., allen m., andrew r., birt a., borger a., boyer t., broersma j.a., cheng l., dentener f., friedlingstein p., gutiérrez j.m., guẗschow j., hall b., ishii m., jenkins s., lan x., lee j.y, morice c., kadow c., kennedy j., killick r., minx j.c., naik v., peters g.p., pirani a., pongratz j., schleussner c.f., szopa s., thorne p., rohde r., corradi m.r., schumacher d., vose r., zickfeld k., massondelmotte v., zhai p. (2023) indicators of global climate change 2022: annual update of largescale indicators of the state of the climate system and the human influence. earth syst. sci. data, 15, 2295-2327. doi: 10.5194/essd-15-2295-2023 fressoz j.b. (2025) more and more and more. an allconsuming history. penguin books, london, pp. 320. 115 the responsibility of geologists in defining the anthropocene. https://www.nature.com/articles/nature23646#auth-heiko-p_like-aff7 https://doi.org/10.1038/nature23646 https://doi.org/10.1093/oxfclm/kgad008 https://doi.org/10.1080/00139157.2025.2434494 https://doi.org/10.1002/jqs.3513 https://doi.org/10.18814/epiiugs/2022/022025 https://doi.org/10.1126/science.319.5862.402 https://www.planetaryhealthcheck.org/ http://www.cambridge.org/9781107661820 https://doi.org/10.1029/2022ef003250 http://www.pnas.org/doi/10.1073/pnas.1809600115 https://doi.org/10.1038/s41586-019-1543-2 http://www.energyinst.org/statistical-review https://doi.org/10.5194/essd-15-2295-2023 zhai p., pirani a., connors s. l., péan c., berger s., caud n., chen y., goldfarb l., gomis m.i., huang m., leitzell k., lonnoy e., matthews j.b. r., maycock t.k., waterfield t., yelekçi o., yu r., zhou b. (eds.)]. cambridge university press, cambridge, united kingdom and new york, ny, usa, pp. 2391 doi: 10.1017/9781009157896 iugs (2024) https://stratigraphy.org/news/152. lee s. s., sharma s., rosenbloom n., rodgers k. b., kim j-e., kwon e. y., franzke c. l. e., kim i-w, sreeush m. g., stein k. (2025) multi-centennial climate change. in a warming world beyond 2100. earth syst. dynam., 16, 1427-1451. doi: 10.5194/esd-16-1427-2025 lenton t.m., held h., kriegler e., hall j.w., lucht w., rahmstorf s., schellnhuber h.j. (2008) tipping elements in the earth's climate system. proceedings of the national academy of science, 105 (6), 1786-1793. doi: 10.1073/pnas.0705414105 lenton t.m., rockström j., gaffney o., rahmstorf s., richardson k., steffen w., schellnhuber h.j. (2019) climate tipping points too risky to bet against, nature, 575, 592-595. doi: 10.1038/d41586-019-03595-0 lenton t.m., armstrong mckay d.i., loriani s., abrams j.f., lade s.j., donges j.f., milkoreit m., powell t., smith s. r., zimm c., buxton j.e., bailey e., laybourn l., ghadiali a., dyke j.g. (eds.) (2023) the global tipping points report 2023. university of exeter, exeter, uk. lenton t.m., milkoreit m., willcock s., abrams j.f., armstrong mckay d.i., buxton j.e. donges j.f., loriani s., wunderling n., alkemade f., barrett m., constantino s., powell t., smith s.r., boulton c.a., pinho p., dijkstra h.a., pearce-kelly p., roman-cuesta r.m., dennis d. (eds.) (2025) the global tipping points report 2025. university of exeter, exeter, uk. https://global-tipping-points.org/ lewis s.l., maslin m.a. (2015) defining the anthropocene. nature, 519. doi: 10.1038/nature14258 li m., bralower t.j., kump l.r., self-trail j.m., zachos j.c., rush w.d., robinson m.m. (2022) astrochronology of the paleocene-eocene thermal maximum on the atlantic coastal plain. nature communications, 13, 5618. doi: 10.1038/s41467-022-33390-x marten g.g. (2005) environmental tipping points: a new paradigm for restoring ecological security. journal of policy studies (japan), 20, 75-87. mccarthy f.m.g., patterson r.t., head m.j., riddick n. l., cumming b.f., hamilton p.b., pisaric m.f.j., a. gushulak c., leavitt p.r., lafond k.m., llew-williams b., marshall m., heyde a., pilkington p. m., moraal j., boyce j.i., nasser n.a., walsh c., garvie m., roberts s., rose n.l., cundy a.b., gaca p., milton a., hajdas i., crann c.a., boom a., finkelstein s.a., mcandrews j.h. and other members of team crawford (2023) the varved succession of crawford lake, milton, ontario, canada as a candidate global boundary stratotype section and point for the anthropocene series. the anthropocene review, 10(1), 146-176. doi: 10.1177/20530196221149281 mccarthy f.m.g., head m.j., waters c.n., zalasiewicz j. (2025) would adding the anthropocene to the geologic time scale matter? agu advances, 6, e2024av001430. doi: 10.1029/2024av001430 möller t., högner a. e., schleussner k.-f., bien s., kitzmann n.h., lamboll r.d., rogelj j., donges j. f., rockström j., wunderling n. (2024) achieving net zero greenhouse gas emissions critical to limit climate tipping risks. nature communications, 15, 6192. doi: 10.1038/s41467-024-49863-0 o’neill b.c., tebaldi c., van vuuren d.p., eyring v., friedlingstein p., hurtt g., knutti r., kriegler e., lamarque j.-f., lowe j., meeh g.a, moss r., riahi k., sanderson b.m. (2016) the scenario model intercomparison project (scenario mip) for cmip6. geoscientific model development, 9(9), 3461-3482. doi: 10.5194/gmd-9-3461-2016 pagani m., zachos j.c., freeman k.h., tipple b., bohaty s. (2005) marked decline in atmospheric carbon dioxide concentrations during the paleogene. science, 309, 600-603. persson l., carney almroth b.m., collins c. d., cornell s., de wit c. a., diamond m.l., fantke p., hassellöv m., macleod m., ryberg m.w., søgaard jørgensen p., villarrubia-gómez p., wang z., hauschild m.z. (2022) outside the safe operating space of the planetary boundary for novel entities. environ. sci. technol., 56, 15101521. doi: 10.1021/acs.est.1c04158 randers j., goluke u. (2020) an earth system model shows self-sustained melting of permafrost even if all man-made ghg emissions stop in 2020. scientific reports, 10, 18456. doi: 10.1038/s41598-020-75481-z richardson k., steffen w., lucht w., bendtsen j., cornell s.e., donges j.f., druk̈e m., fetzer i., bala g., von bloh w.,feulner g., fiedler s., gerten d., gleeson t., hofmann m., huiskamp w., kummu m., mohan c., nogués-bravo d., petri s., porkka m., rahmstorf s., scaphoff s., thonicke k., tobian a., virkki v., wangerlandsson l., weber l., rockström j. (2023) earth beyond six of nine planetary boundaries. sci. adv., 9, eadh2458. doi: 10.1126/sciadv.adh2458 rockström j., steffen w., noone k., persson å, chapin f.s., lambin e.f., lenton t.m., scheffer m., folke c., schellnhuber h.j., nykvist b., de wit c.a., hughes t., van der leeuw s., rodhe h., sorlin s., snyder p.k., costanza r., svedin u., falkenmark m., karlberg l., corell r.w., fabry v.j., hansen j., walker b., liverman d., richardson k., crutzen p., foley j. (2009) a safe operating space for humanity. nature, 461, 472-475. doi: 10.1038/461472a smil v. (2017) energy and civilisation: a history. the mit press, cambridge, massachusetts, pp. 552. doi: 10.7551/mitpress/9780262035774.001.0001 steffen w., broadgate w., deutsch l., gaffney o., ludwig c. (2015a) the trajectory of the anthropocene: the great acceleration. the anthropocene review, 2(1), 81-98. 116 zampieri d. https://doi.org/10.1017/9781009157896 https://stratigraphy.org/news/152 https://doi.org/10.5194/esd-16-1427-2025 http://www.pnas.org/cgi/doi/10.1073/pnas.0705414105 https://global-tipping-points.org/ https://doi.org/10.1038/nature14258 https://doi.org/10.1038/nature14258 https://doi.org/10.1038/s41467-022-33390-x https://doi.org/10.1038/nature14258 https://doi.org/10.1177/20530196221149281 https://doi.org/10.1029/2024av001430 https://doi.org/10.1038/s41467-024-49863-0 https://doi.org/10.5194/gmd-9-3461-2016 https://doi.org/10.1021/acs.est.1c04158 https://doi.org/10.1038/s41598-020-75481-z https://doi.org/10.1126/sciadv.adh2458 https://www.nature.com/articles/461472a#auth-_sa-persson-aff1-aff2 wang-erlandsson l., tobian a., van der ent r.j., fetzer i., te wierik s., porkka m., staal a., jaramillo f., dahlmann h., singh c., greve p., gerten d., keys p.w., gleeson t., cornell s.e., steffen w., bai x., rockström j. (2022) a planetary boundary for green water. nat. rev. earth environ., 3, 380-392. doi: 10.1038/s43017-022-00287-8 waters c.n., turner s. d., zalasiewicz j., head m.j. (2023) candidate sites and other reference sections for the global boundary stratotype section and point of the anthropocene series. the anthropocene review, 10(1), 3-24. doi: 10.1177/20530196221136422 waters c.n., turner s., an z., barnosky a., cearreta a., cundy a., fairchild i., fiałkiewicz-kozieł b., gałuszka a., grinevald j., hajdas i., han y., head m.j., ivar do sul j.a., jeandel c., leinfelder r., mccarthy f., mcneill j., odada e., oreskes n., poirier c., deb richter d., rose n., saito y., shotyk w., summerhayes c., syvitski j., vidas d., wagreich m., williams m., wing s., zalasiewicz j., zinke j. (2024) proposals by the anthropocene working group: executive summary, part 1 and part 2, eartharxiv. doi: 10.31223/x5vh70 zachos j., pagani m., sloan l., thomas e., billups k. (2001) trends, rhythms, and aberrations in global climate 65 ma to present. science, 292, 686693. doi: 10.1126/science.1059412 zalasiewicz j., steffen w., leinfelder r., williams m., waters c.n. (2017) petrifying earth process: the stratigraphic imprint of key earth system parameters in the anthropocene. theory, culture & society, 34, 83-104. doi: 10.1177/0263276417690587 zalasiewicz j., waters c.n., williams m., summerhayes c.p. (eds.) (2019) the anthropocene as a geological time unit: a guide to the scientific evidence and current debate. cambridge university press, 361 pp. zeebe r.e., ridgwell a., zachos j.c. (2016) anthropogenic carbon release rate unprecedented during the past 66 million years. nature geoscience. doi: 10.1038/ngeo2681 doi: 10.1177/2053019614564785 steffen w., richardson k., rockström j., cornell s.e., fetzer i., bennett e.m., biggs r., carpenter s.r., de vries w., de wit c.a., folke c., gerten d., heinke j., mace g.m., persson l.m., ramanathan v., reyers b., sörlin s. (2015b) planetary boundaries: guiding human development on a changing planet. science, 347, 1259855. doi: 10.1126/science.1259855 steinthorsdottir m., coxall h.k., de boer a.m., huber m., barbolini n., bradshaw c.d., burls n.j., feakins s.j., gasson e., henderiks j., holbourn a.e., kiel s., kohn m.j., knorr g., kur̈schner w. m., lear c.h., liebrand d., lunt d.j., mörs t., pearson p.n, pound m.j., stoll h., strömberg c. a.e. (2021) the miocene: the future of the past. paleoceanography and paleoclimatology, 36, e2020pa00 4037. doi: 10.1029/2020pa004037 stenzel f., ben uri l., braun j., breier j., erb k., gerten d. (2025) breaching planetary boundaries: over half of global land area suffers critical losses in functional biosphere integrity. one earth, 8, 101393. doi: 10.1016/j.oneear.2025.101393 summerhayes c.p., zalasiewicz j., head m.j., syvitski j., barnosky a.d., cearreta a., fiałkiewicz-kozieł b., grinevald j., leinfelder r., mccarthy f.m.g., mcneill j.r., saito y., wagreich m., waters c.n., williams m., zinke j. (2024) the future extent of the anthropocene epoch: a synthesis. global and planetary change, 242, 104568. doi: 10.1016/j.gloplacha.2024.104568 von schuckmann k., minière a., gues f., cuestavalero f.j., kirchengast g., adusumilli s., straneo f., ablain m., allan r.p., barker p.m., beltrami h., blazquez a., boyer t., cheng l., church j., desbruyeres d., dolman h., domingues c.m., garcía-garcía a., giglio d., gilson j. e., gorfer m., haimberger l., hakuba m.z., hendricks s., hosoda s., johnson g.c., killick r., king b., kolodziejczyk n., korosov a., krinner g., kuusela m., landerer f.w., langer m., lavergne t., lawrence i., li y., lyman j., marti f., marzeion b., mayer m., macdougall a.h., mcdougall t., monselesan d.p., nitzbon j., otosaka i., peng j., purkey s., roemmich d., sato k., sato k., savita a., schweiger a., shepherd a., seneviratne s.i., simons l., slater d. a., slater t., steiner a.k., suga t., szekely t., thiery w., timmermans m.l., vanderkelen i., wjiffels s.e., wu t., zemp m. (2023) heat stored in the earth system 19602020: where does the energy go? earth syst. sci. data, 15, 1675-1709. doi: 10.5194/essd-15-1675-2023 ms. received: october 2, 2025 revised: november 5, 2025 accepted: november, 11, 2025 available online: november 20, 2025 117 the responsibility of geologists in defining the anthropocene. https://doi.org/10.1038/s43017-022-00287-8 https://doi.org/10.1177/20530196221136422 https://doi.org/10.31223/x5vh70 https://doi.org/10.1177/0263276417690587 https://doi.org/10.1038/ngeo2681 https://doi.org/10.1177/2053019614564785 https://doi.org/10.1126/science.1259855 https://doi.org/10.1029/2020pa004037 https://doi.org/10.1016/j.oneear.2025.101393 https://doi.org/10.1016/j.gloplacha.2024.104568 https://doi.org/10.5194/essd-15-1675-2023 118 sess 0_retro e indice edi.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 relative sea level during the last millennium on the basis of archeological markers. new information from tuscany and northern sardinia   porqueddu alessandro1,2, antonioli fabrizio3, ducci silvia4 & pasquinucci marinella5 1 dipartimento scienze del mondo antico, pisa; 2 scuola di specializzazione in archeologia subacquea e dei paesaggi costieri, oristano 3 enea, dipartimento ambiente, casaccia, roma 4 soprintendenza per i beni archeologici della toscana, livorno 5 diparitmento di scienze del mondo antico, pisa corresponding author: a. porqueddu, <aleporqueddu@hotmail.it> abstract: porqueddu et al., relative sea level during the last millennium using archeological markers. new information from tuscany and northern sardinia. (it issn 0349-3356, 2011). preliminary results have been produced on a multi-disciplinary analysis about the opportunity to test paleo sea level on the basis of geo-archaeological signs. the study has concerned tuscany and northern sardinia sea coast, for the provinces of livorno and olbia. in order to decrease the error bar measurements was corrected for tide and atmospheric pressure using the same method of antonioli et al. (2007). the functionality of the archaeological marker was calculated on the basis of lambeck et al. (2004b) and auriemma et al. (2009). then the observed and corrected has been compared with the predicted sea level curve of lambeck et al. (2011). riassunto: porqueddu et al., variazioni del livello del mare durante gli ultimi millenni sulla base di indicatori archeologici. nuovi dati dalla toscana e dalla sardegna settentrionale. (it issn 0349-3356, 2011) vengono presentati i risultati preliminari di uno studio multidisciplinare sulla possibilità di misurare antichi livelli del mare sulla base di indicatori geo-archeologici. lo studio ha interessato le coste della toscana e della sardegna settentrionale, con particolare attenzione per le province di livorno e olbia. al fine di ridurre al minimo le incertezze altimetriche, gli indicatori sono stati misurati direttamente in situ e le relative quote sono state corrette per i valori di marea e pressione atmosferica registrati al momento della misurazione (antonioli et al., 2007). a queste misure è stata poi apportata una correzione basata sull’altezza rispetto al livello medio del mare che, originariamente, doveva garantire la funzionalità del marker archeologico (lambeck et al., 2004; auriemma et al., 2009). i dati ottenuti sono stati poi comparati con le previsioni dei più recenti modelli teorici di previsione validi per le stesse regioni (lambeck et al., 2011). key words: relative sea level parole chiave: livello relativo del mare  the soprintendenza per i beni archeologici and the dipartimento di scienze storiche del mondo antico, university of pisa, made some archaeological excavations and measurements on coastal archaeological markers in the site portus pisanus (livorno). the 2004 excavation campaign (located in “il deserto”) allowed to restore the stratigraphical sequence of the area from the late 7thearly 6th cent. bc to the 6th cent. ad (ducci et al., 2006). the stratigraphical level included between –130 and 160 cm a.s.l., has been identified as the sandy floor of a marine gulf used as maritime trade from the 3rd cent. bc up to the 1st cent. bc. this stretch of water was progressively and rapidly silted up by alternate sand and posidonia layers since the mid 2nd cent bc. in the late 1st cent bc activities connected with navigation could no longer be performed in this area and were moved to the west (ducci et al., 2005). this information has been improved by the analysis of the specimens of malacofauna using 14c, that were taken during the excavations from the same stratigraphical unit (us 23, -140 ± 5 cm a.s.l.). this has provided a date of 2071 ± 44 years cal bp. according to the excavation evidence, it has been supposed that this area had to be used by appropriate sheeps (so with a clearance value of 35 cm). we assume the chronological period of use was between 2210 ± 100 years bp. adding to the medium bottom level (-145 ± 15 cm a.s.l.) correction for tide (about 20 cm) and the supposed functional depth (35 cm), we get a change of sea level of 90 ± 15 cm from 2210 ± 100 year bp. along the coast south of livorno (at calafuria and surroundings) the evidence interpreted as stone quarry si activities in antiquity marked on the flysch which is typical of the cliffs of livorno’s mountains (galoppini et al.,1994) has been measured in situ. particular attention was given to the detaching surfaces of the blocks (certainly related to anthropic activity), today flooded by the sea. in the southern side of the quarry a small inlet has been identified. it is approximately rectangular-shaped, suited to hold medium size boats. near it, a docking ring 200 201 201 ms. received: testo ricevuto il has been supported, in the edge of the rock ( at the moment at about 20 cm a.s.l.). the construction marks are still evident (it may be because of chiselling). it is unlikely to be of natural formation. the selected point for the measurement has been located on the surface of a removed block with dimensions of 60x215 cm, measured at a depth of -95 cm a.s.l. (corretto). according to previous studies (antonioli et al., 2007; auriemma et al., 2009) we suppose that the quarry area had to be found at an altitude above the medium sea level so that it always had dry conditions, even in case of high tide (30 ± 30 cm above high tide level). the quarry level we propose, according to the chronology assigned in the bibliography (galoppini et al., 1994), is the hellenistic period. therefore we propose a change of sea level of +148 ± 30 cm from 2300 ± 100 years bp. geomorphologic features of the olbia gulf are well known thanks to intense surveys which have been of interest outside the gulf (segre, 1954; porqueddu et al., 2010). in 1999 the recovery of a few wrecks, due to the works for the implementation of the connecting tunnel between the extraurban network and the modern seaport, has provided new data to determine sea level variations on the inland side of the gulf. the soprintendenza per beni archeologici per le province di sassari e nuoro (olbia branch) excavated the remains of at least 24 boats of different sizes dated between the 1st and the 5th century ad and in the medieval period. due to the particular features of positions and the chronologically homogeneous context where they were integrated, only the relics found in the northern area of the excavation have been considered. the ships ,at the time of their destruction, must have been moored inside the harbour area with a low bottom (d’oriano, 2002). therefore it was chosen to determine the paleo sea level starting from the level of the placement of the wrecks measured at the base of the keel. to date this context the interpretations of the soprintendenza have been followed. the event was first dated around the middle of the 5th century ad, during the period of the vandal invasions. according to later theories, a date beyond 1560 ± 10 years bp is suggested. the height that the keel is positioned at with regard to the wreck has been measured at -145 cm a.s.l. (corretto). to this data has been added the functional height of the harbour area, needed to warrant the ships floating (40 cm) and included the higher sea level in case of mistakes (because when dealing with wrecks it cannot be excluded, that particularly during low sea level phases, the keels could be based on the floor)(riccardi, 2002). according to what has been changing of the relative sea level inside the gulf of olbia can be quantified in +105 ± 23cm from 1560 ± 10 years bp (porqueddu et al., 2010). comparing observed data connected with the sea level at portus pisanus and olbia, and the predicted sea level curves (lambeck et al., 2011), the proposed working hypothesis, in addition to confirming the tectonic stability of the searched areas, expresses a substantial uniformity between the obtained results and what was predicted, including differences in the indicated visible margins of error. more distant from the model of prevision is the datum of calafuria: this anomaly will be explained only with further researches in situ. references antonioli f., anzidei m., lambeck k., auriemma r., gaddi d., furlani s., orru` p., solinas e., gaspari a., karinja s., kovacĭc v., & surace l. (2007) sealevel change during the holocene in sardinia and in the northeastern adriatic (central mediterranean sea) from archaeological and geomorphological data, quaternary science reviews 26, 2463–2486. auriemma r. & solinas e. (2009) archaeological remains as sea level change markers: a review, quaternary international xxx, 1–13. d’oriano r. (2002) relitti di storia: lo scavo nel porto di olbia, in xiv convegno di studi sull’africa romana, 1249-1262. ducci s., pasquinucci m., menchelli s. & genovesi s. (2005) la scoperta del portus pisanus, in c. marcucci-c. megale (a cura di), rete archeologica. valorizzazione e ricerche, atti del convegno, 29-44. ducci s., pasquinucci m. & genovesi s. (2006) livorno. ricerche archeologiche a portus pisanus: la campagna 2006, in notiziario della soprintendenza per i beni archeologici della toscana, 2/2006, 238-241. galoppini r., letta c., mazzanti r., taddei m., tessari r. & viresini l. (1994) possibilità di misura di antichi livelli del mare nel litorale tra le foci dei fiumi arno e fine in toscana, in memorie e descrizioni della carta geografica d‟italia lii, 279-292. lambeck k., anzidei m., antonioli f., benini a. & esposito a. (2004) sea level in roman time in the central mediterranean and implications for recent change, earth and planetary science letters, volume 224, 3-4, 563-575. lambeck k, antonioli f., anzidei m., ferranti l., leoni g., scicchitano g. & silenzi s. (2011, in press) sea level change along italian coast during holocene and a proiection for the future. journal of quaternary international. porqueddu a., antonioli f., d’oriano r., gavini v., trainito e., verrubbi v. (2010, in press) relative sea level change in the olbia gulf (sardinia, italy) an important mediterranean harbour during last millennia, quaternary international. riccardi e. (2002) i relitti del porto di olbia, in xiv convegno di studi sull'africa romana, 1263-1274. segre a.g. (1954) il tirreniano del golfo di terranova pausania (olbia) e la sua fauna malacologica. bollettino del servizio geologico d'italia, 76, 43-74. january 15, 2011 15 gennaio 2011 sess 0_retro e indice edi.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 the grotta dei fiori (sardinia) stratigraphic succession: a multidisciplinary approach rita teresa melis1, maria rita palombo2, bassel ghabel3,, roberto boldrini2,& paola iacumin4 1 dipartimento scienze della terra, università di cagliari 2 dipartimento scienze della terra,università “sapienza” roma, 3 geotop-uqam, université du québec à montréal, canada 4dipartimento di scienze della terra, università, parma corresponding author: rita t. melis <rtmelisl@unica.it> abstract: melis r.t. et al., the grotta dei fiori (sardinia) stratigraphic succession; a multidisciplinary approach. (it issn 0394-3356, 2011) grotta dei fiori cave is one of the many limestone caves in south western sardinia containing well-stratified fossiliferous deposits intercalated with flowstones. a multidisciplinary methodological approach (paleontological, sedimentological, stable isotope analyses) and u/th datation, has been used to define the palaenvironmental context and chronology of fossiliferous deposits in the cave. riassunto: melis r.t. et al., la successione stratigrafica di grotta dei fiori (sardegna): approccio multidisciplinare. (it issn 0394-3356, 2011) grotta dei fiori è una delle numerose grotte nella sardegna sud occidentale caratterizzata da sedimenti ricchi in resti fossili intercalati con flowstones. la correlazione e l’interpretazione dei risultati di uno studio multidisciplinare (paleontologico, sedimentologico, analisi isotopica) e datazioni u/th, sono stati utilizzati per definire il contesto paleoambientale e precisare l’ intervallo cronologico dei depositi fossiliferi presenti nella grotta. key words: pleistocene, biochronology, sardinia. parole chiave: pleistocene,, biocronologia, sardegna grotta dei fiori cave (carbonia, sardinia) is one of the many caves in south western sardinia that contains fossiliferous deposits with large and small mammals intercalated with flowstones. the cave is localized nearby the carbonia town and developed in a cambrian limestone (“gruppo di gonnesa”) slightly metamorphosised by ercinic tectonic (fig.1). the hypogean karstification started at lower cambrian and continued at different times until the quaternary. the cave evolution was made through various spelaeogenetic cycles characterised by a succession of sedimentation, erosion and collapsing phases. probably sedimentation started in the permo-trias, as supported by data on karst evolution in the iglesias area (civita et al. 1986). the oldest (?) deposits likely correspond to fine sediments filling some fissures in the ceiling of main cavities. the pliopleistocene deposits, mainly fine and coarse sediments, are the most abundant and are characterised by rich small mammal remains (melis et al. 2002b). a multidisciplinary study has been carried out with the aim of reconstructing the cave evolution and finding a more accurate attribution of fossiliferous deposits cropping out in the karstic cave, through the correlation and interpretation of the results of different disciplinary approaches (palaeontology, geochemistry, sedimentology, soil micromorphology and u/th datation). three fossiliferous sequences have been identified outside, on the first and on the third cavity of “grotta dei fiori” cave (fig.2). the sequence u, localized outside the cave in a man-made cut of the second entrance, is characterized, in the bottom, by clayed deposits with mudcracks filled by calcite. follows a flowstone, about 30 cm thin, covered by cemented chaotic coarse deposits composed by large fragments of the previous flowstone, limestone fig. 1, location of grotta dei fiori. ubicazione di grotta dei fiori. 150 151 151 ms. received: testo ricevuto il clasts and red fine matrix with abundant fossil remains confined to small areas. the upper sequence ends with a thick flowstone. the sequence c, is formed by sub-horizontal levels ending with a flowstone of 25 cm. this sequence, about 5 m thick, is subdivided into two units: lower unit (unit a), characterised by fine red clay sediments with pedoretlicts interpreted as deposits which were washed into the back of the cave by gentle water flow of eroded soils developed outside. the transition from the lower to the upper unit b is marked by a level characterised by 3 thin flowstones alternated by levels of red clay sediments. this level is characterised by fine sediments interbedded with coarse clastic deposits. the coarse clastic deposits are poorly sorted and contain bone fragments. the amount of pedorelicts within the fine sediments matrix, suggests erosion of soils originated outside the cave, which fell into the cave. in the unit b, the poorly to well-developed internal layering, the angular to subangular shape of clasts, the large amount of pedorelicts in the fine matrix with coarse sediments, indicates that soils from outside the cave were catastrophically and suddenly washed down the slope and deposited into the cave. the sequence d, about 8 m thick, is formed by clayed and coarse sediments. the lower unit (unit a) is characterised by fine sediments, whereas the upper one (unit b) mostly by coarse deposits. the lower unit a, interbedded between two thin flowstones, consists of alternating clayed and sandy levels with poor fossil remains. the upper unit b is composed by predominantly coarse sediments and abundant fossil remains. the upper sequence ends with a flowstone about 10 cm thick. fossiliferous levels occur in all the above described stratigraphic sequences. small mammals (microtus (tyrrhenicola), ragamys, “nesiotites” and prolgagus) are always present, but so far only voles from the sequence c have been preliminarily analysed. the upper level sequence c, includes several fossiliferous levels from which a rich sample of small mammals have been retrieved. scanty remains of a quite large cynotherium aff. c. sardous and some no endemic birds (ciconia nigra, gypaetus barbatus, aquila sp., columba livia, pyrrhocorax pyrrhocorax, pyrrhocorax graculus, corvus corone, corvus corax, emberiza cirlus/schoeniclus) have been found in the uppermost fossiliferous level (melis et al. 2002; pavia & bedetti 2003, boldrini et al. 2010). data provided by sedimentology, soil micromorphology and geochemistry indicate that the fossiliferous sequences of “grotta dei fiori” was deposited under climatic conditions characterized by an alternation of wet and dry periods (boldrini et al 2010). taking into account results of palaeontological analysis, the hypothesis that the “grotta dei fiori” succession would be not older than the marine isotope stage (mis) 11 cannot be ruled out. u/th dating of flowstones, directly associated with this deposits, roughly support this hypothes, indicating that depositional events in the grotta dei fiori cave, occurred during the middle pleistocene from mis 11 to mis 9?. references boldrini r., palombo m.r., iacumin p. & melis r. (2010) the middle pleistocene fossiliferous sequence of grotta dei fiori (sardinia, italy): multidisciplinary analysis. boll. soc. palontologica it., 49 (2), 123-134. civita m., cocozza t., forti p., perna g. & turi b. (1986) identification of groundwater flow parameters of karstic aquifer in the mining district of iglesiente (sardinia-italy). cee "resources report eur 10572 en, 1-56. melis r.t., palombo m.r., bedetti c., fenza p., pavia m., mureddu m. & villani m. (2002). evoluzione speleogenetica e paleoambientale della grotta dei fiori sa/ca 218 (carbonia-sardegna sud-ccidentale). anthéo bollettino gruppo speleoarcheo giovanni spano di cagliari, 6, 71-88. pavia m. & bedetti c. (2003) the late pleistocene fossil avian remainsfrom grotta dei fiori, carbonia (sw sardinia, italy). boll. soc. paleontologica it., 42, 163-169. fig. 2, localization and plan of grotta dei fiori cave, from: elenco catastale delle grotte del comune di carbonia, gruppo ricerche speleologiche “e. a. martel” carbonia (1977). ubicazione e pianta della grotta dei fiori, da: elenco catastale delle grotte del comune di carbonia, gruppo ricerche speleologiche “e. a. martel” carbonia (1977). january 15, 2011 15 gennaio 2011 the grotta dei fiori (sardinia) stratigraphic succession ... imp.bigazzi& datazione di un livello cineritico del pleistocene medio: relazioni con sedimentazione, sollevamento e terrazzi marini nell’area crosia-calopezzati in calabria (italia) giulio bigazzi1 & luigi carobene2 1c.n.r., istituto di geoscienze e georisorse, via g. moruzzi, 1 – 56124 pisa 2dip.te.ris., università degli studi, corso europa, 26 – 16132 genova riassunto: bigazzi g. & carobene l., datazione di un livello cineritico del pleistocene medio: relazioni con sedimentazione, sollevamento e terrazzi marini nell’area crosia-calopezzati in calabria (italia). (it issn 0394-3356, 2004). nell’area di crosia-calopezzati, in destra del fiume trionto (calabria ionica), affiora un potente prisma sedimentario pleistocenico che, nelle parti più prossimali, è trasgressivo sui terreni miocenici. il sollevamento dell’area ha originato la formazione di 4 ordini di terrazzi marini, già descritti in un precedente lavoro; il rinvenimento e la datazione di un livello cineritico nel substrato argilloso pleistocenico ha permesso di ottenere una datazione indiretta degli stessi. il livello cineritico, per il quale è stata calcolata un’età di 450.000 anni ±10% con il metodo delle tracce di fissione, è stato infatti inquadrato stratigraficamente all’interno del corpo sedimentario; ciò ha consentito di trarre anche ulteriori deduzioni e ipotesi, sia cronologiche che quantitative, sul sollevamento e sull’emersione del prisma sedimentario pleistocenico e sulle velocità di sedimentazione. abstract: bigazzi g. & carobene l., fission-track dating of middle pleistocene ash layer: relationships to sedimentation, tectonic uplift and marine terraces in the crosia-calopezzati area (calabria, italy). (it issn 0394-3356, 2004). in the crosia-calopezzati area (ionian coast of calabria), east of the trionto river, crops out a pleistocene marine succession which is transgressive over miocene – pliocene (?) substratum (fig. 1; fig. 2). these sediments deposited during a lowering phase of the ionian margin, which caused the formation of important sedimentary basins in calabria and basilicata. a significant stage of knowledge of the geology of these regions during lower and middle pleistocene times had been already attained through studies that were performed on these basins. the uplift of the study area determined the formation of four orders of marine terraces (fig. 5) already described in a previous article (carobene, 2003). discovery and analysis of an ash layer interstratified with the pleistocene clayey substratum (fig. 3) provided the opportunity of inferring some considerations on the sedimentation rate and, consequently, on the onset of the sedimentation of the transgressive body. it was also possible to deduce some constraints on the beginning of its emersion as well as on the age of the marine terraces and on the uplift rate of the study area. the main results of this work can be summarized as follows (fig. 9): 1) age determination of the pyroclastic layer. the ash layer, referred to as “calopezzati ash”, looks poorly cemented, porous and white colored. dating of a population of glass shards separated from the calopezzati ash was performed using the fission-track method at the c.n.r. institute of geosciences and earth resources of pisa (fig. 4). an age of 450,000 a ± 10 % was determined (table 1). taking into account the close analogies found out with the pyroclastic layer named “parmenide ash” recognized in the nearby cutro basin, in the crotone peninsula (massari et alii, 2001), the deposition age of the calopezzati ash might be 420,000 a. 2) sedimentation rate. the position of the studied ash inside the sedimentary body allowed to compute a thickness of the overhanging clay cover of around 100 m and to deduce that sedimentation stopped at the end of mis 9 (280,000 a ago) (fig. 8). therefore, during the considered time span the average sedimentation rate was around 0.6 mm/a. 3) coastal area lowering (subsidence) and pleistocene sedimentation. based upon the mean sedimentation rate (see point 2 above) and taking into account the computed thickness of the sedimentary prism (around 400-500 m), we argue that sedimentation started during late lower pleistocene – early middle pleistocene times. 4) onset of the tectonic uplift. the onset of the uplift of the area is about coeval with the ash deposition, therefore an age of around 450,000 a can be deduced for the beginning of the uplift phase (fig. 6 a). 5) emersion of the sedimentary prism. obviously emersion is diachronic. it took place with evidence in correspondence with the eustatic lowering following the interglacial peak of mis 11, and it is testified by the sediments located at higher elevation (277 m, fig. 5); the sedimentary top does not coincide with the most recent sediments. 6) tectonic uplift and marine terracing. the interglacial high level subsequent the first emersion is attributed to the mis 9. it originated a wide terrace (i order terrace) nowadays to a great extent remodelled, with an inner margin at an elevation of 210 m (fig. 5). an algal limestone sample yielded a th/u ≥ 300.000 a (carobene, 2003). we computed an average uplift rate of 0.62 mm/a. we assume that the clayey sedimentation stopped with the eustatic lowering (fig. 8 – a e b). the following interglacial eustatic high level (mis 7) determined the formation of the ii order terrace which nowadays has an inner margin of 105÷120 m (chapter 4); the corresponding average uplift rate is 0.56 mm/a (tab. 2). the eustatic peak corresponding to mis 5.5 originated the iii order terrace, with an inner margin at present at around 65÷70 m; the average uplift rate is 0.50 mm/a (tab. 2). the last eustatic high of stage 5 (mis 5.1) produced the iv order terrace, which is of less importance than the previous ones as regards surface width and sediments thickness. the present elevation of its inner margin, 25÷30 m, allowed us to compute an average uplift rate of 0.46 mm/a. the chronological succession of the four orders of terraces and of the sedimentary top elevations (fig. 5 and tab. 2) proves an almost steady course of the uplift rate (fig. 6 – b), slightly decreasing with time (from 0.69 down to 0.46 mm/a). taking into account the uncertainties related to the attribution of the age to the palaeo-eustatic peaks and to the estimate of their original elevation, we have reckoned the variability interval of the computed uplift rate values reported above (fig. 7). parole chiave: livello cineritico, datazione con le tracce di fissione, terrazzi marini, tettonica quaternaria, eustatismo, pleistocene, calabria. keywords: ash layer, fission-track dating, marine terraces, quaternary tectonics, eustasy, pleistocene, calabria. il quaternario italian journal of quaternary sciences 17(2/1), 2004, 151-163 152 g. bigazzi & l. carobene 1. premessa nella presente nota viene utilizzata una data ricavata da un livello piroclastico, denominato “cinerite di calopezzati”, presente nel substrato argilloso pleistocenico, per definire la cronologia dei terrazzi marini sviluppati nell’area di crosia-calopezzati. la datazione è stata effettuata con il metodo delle tracce di fissione; le relative procedure di laboratorio vengono esposte nel cap. 3. gli eventi successivi alla deposizione del l ivello cineritico sono stati: 1) il completamento del corpo sedimentario che costituisce il substrato; 2) il sollevamento; 3) la formazione dei terrazzi marini, in relazione alla progressiva emersione dell’area e alle oscillazioni glacioeustatiche. i 4 ordini di terrazzi riconosciuti (fig. 1) sono stati descritti in dettaglio da carobene (2003); in conformità con dette descrizioni, i margini interni dei terrazzi corrispondono ai “margini interni geometricamente ricostruiti”, ritenuti equivalenti alle paleolinee di riva. i terrazzi vengono qui ricordati brevemente. i ordine: crinali suborizzontali, risultato di un forte rimodellamento di una superficie terrazzata avente margine interno a circa 210 m. nel settore di crosia l’ampiezza massima raggiunge quasi 2500 metri; lembi di depositi marini sono stati osservati solo tra 130 e 169 m di quota. alcune faglie dislocano il terrazzo, contribuendo al notevole dislivello esistente tra margine interno e orlo esterno. ii ordine: relitti di superfici terrazzate, con ampiezza massima di 1000 m e margine interno a 105÷120 m. i depositi marini e continentali raggiungono uno spessore complessivo massimo di 45 m. iii ordine: relitti ancora ben conservati di superfici terrazzate, con margine interno a 64÷71 m; l’ampiezza massima è di 800 m, ma si riduce drasticamente a se del t. fiumarella. i depositi marini e continentali terrazzati sono presenti con uno spessore massimo di 25 m. iv ordine: è rappresentato da pochi relitti di superfici aventi ampiezza non superiore a 170 m e margine interno a 25÷30 m. i depositi terrazzati hanno spessori di pochi metri e a volte sono assenti. sono stati considerati i possibili errori che entrano in gioco nei calcoli (errori di quota, di età, di spessori, ecc.), al fine di verificare il possibile campo di variabilità dei tassi di sollevamento (tab. 2). fig. 1 carta geologica schematica della distribuzione del substrato pleistocenico nell’area di crosia e calopezzati. sono inoltre mappati i depositi o le forme riferibili ai quattro ordini di terrazzi marini rilevati (carobene, 2003). 1)substrato miocenico; 2)argille e sabbie del pleistocene; 3) forme relitte e lembi di depositi del i ordine; 4) depositi del terrazzo del ii ordine, 5) depositi del terrazzo del iii ordine; 6) forme relitte e lembi di depositi del terrazzo del iv ordine; 7) depositi colluviali, depositi alluvionali e depositi costieri recenti e attuali; 8) linea di correlazione dei terrazzi marini; 9) giaciture di strato; 10) ubicazione della cinerite; 11) centri abitati. geological schematic map showing the distribution of the pleistocene substratum in the crosia – calopezzati area. the deposits or the features referable to the surveyed four orders of marine terraces (carobene, 2003) are also shown. 1) miocene substratum; 2) pleistocene clays and sands; 3) relict landforms and deposit remains of the 1st order terrace; 4) deposits of the 2nd order terrace; 5) deposits of the 3rd order terrace; 6) relict landforms and deposit remains of the 4th order terrace; 7) present or recent colluvial, alluvial and coastal deposits; 8) correlation line of the marine terraces; 9) bed attitude; 10)location of the sx.819 ash level; 11) towns. 2. stratigrafia nell’area di studio (fig. 1) il substrato è costituito da un prisma sedimentario pleistocenico di notevole spessore, rilevato in dettaglio al fine di ricostruire al meglio la successione stratigrafica (carobene, dati inediti); il pleistocene di crosia è stato descritto precedentemente da panizza (1967). le variazioni litologiche e sedimentologiche riscontrate, considerate sia in senso verticale che areale (da mare verso terra), indicano che si tratta di una sequenza sedimentaria originatasi per una progressiva e prolungata fase trasgressiva, culminata in un alto stazionamento eustatico finale, che ha preceduto l’emersione dell’area. l’innalzamento del livello marino è coinciso con una lunga fase di subsidenza (periodo della sedimentazione della sequenza), alla quale è seguita una fase di sollevamento tettonico (periodo dell’emersione e del terrazzamento marino). la colonna stratigrafica di fig. 2 indica in modo schematico la litologia; le sabbie gialle basali sono riferibili al periodo trasgressivo, e sono ben osservabili nella zona costiera più interna (più sollevata); le argille siltose grigio-azzurre occupano invece la restante fascia di territorio fino al mare, tanto da non permettere l’osservazione della parte stratigrafica basale. la colonna rappresenta quindi la successione cronostratigrafica; lo spessore rappresentato è relativo, in quanto esso varia da un minimo a monte ad un massimo (calcolato) di 400 e forse maggiore di 500 m a valle. le giaciture di strato variano da circa 15° a monte a 9-10° a valle; esse hanno permesso una discreta valutazione degli spessori, complicata tuttavia dalla presenza di faglie. la messa in posto del livello della cinerite di calopezzati, così come le successive fasi sedimentarie, eustatiche e tettoniche, sono state riferite cronologicamente alla curva isotopica dell’ossigeno (cap. 5). l’età della cinerite (cap. 3) e dello spessore di argille (circa 100 m) che lo sovrasta, hanno permesso inoltre di ricavare indicazioni sulla velocità media della loro sedimentazione e quindi, estrapolando il dato all’intero spessore del prisma sedimentario, di avanzare un’ipotesi sull’inizio della sedimentazione (cap. 4.3). 3. la datazione del livello cineritico il livello cineritico è stato rinvenuto ed osservato, circa alla quota di 45 m, lungo la strada che unisce la stazione di calopezzati con il paese di calopezzati (fig. 1), sul fianco destro di una valle che ha inciso la superficie terrazzata estesa tra le quote di 75 e 96 metri (terrazzo del ii ordine – carobene, 2003). lavori di sbancamento lungo il versante argilloso hanno portato alla luce un livello biancastro, poroso, leggero, poco cementato, spesso alcuni centimetri; a volte la cinerite era presente in lenti o sacche più spesse, non cementata (fig. 3). il campione sx.819 è stato analizzato con il metodo sem – eds e con il metodo delle tracce di fissione per ottenerne rispettivamente la composizione chimica e l’età. 3.1. datazione con il metodo delle tracce di fissione la datazione con il metodo delle tracce di fissione si basa sulla scoperta, fatta negli anni 60 del secolo scorso, che minerali e vetri naturali mantengono memo153datazione di un livello cineritico ... ria degli eventi di fissione nucleare dell’u238 prodotti al loro interno nei tempi geologici. ogni evento di fissione produce nel solido nel quale avviene una regione danneggiata – una traccia cilindrica lunga ~ 10 ÷ 20 µm – chiamata “traccia latente” osservabile soltanto al microscopio elettronico, che può essere rivelata con un opportuno attacco chimico in modo da essere osservafig. 2 colonna stratigrafica schematica rappresentativa del substrato pleistocenico. lo spessore è stato calcolato in base ad una ricostruzione geometrica del corpo sedimentario basata sulle giaciture di strato; le sabbie basali sono affioranti nella parte prossimale (verso terra), mentre le argille sommitali sono affioranti nella parte distale (verso mare). la deposizione delle argille che sovrastano la cinerite (450.000 anni) è terminata con il mis 9 (vedi fig. 8). schematic stratigraphy of the pleistocene substratum. thickness was estimated through geometric reconstruction of the sedimentary body. the basal sands crop out in the proximal part ( landward), whereas the upper clays crop out in the distal part (seaward). deposition of the clay overhanging the sx.819 ash level (450,000 years) stopped at the end of mis 9 (see also fig. 8). fig. 3 livello piroclastico bianco (cinerite di calopezzati) affiorante alla quota di circa 45 m; è venuto alla luce per un’azione di sbancamento del versante argilloso. white pyroclastic layer (calopezzati ash) cropping out at an elevation of about 45 m. it came to light in consequence of excavation works made on a clayey slope. 154 bile con un comune microscopio ottico. dato che la fissione nucleare spontanea dell’u238 avviene ad un tasso costante nel tempo, il numero di tracce di fissione accumulate nei tempi geologici, dette tracce “fossili”, in un minerale o in un vetro naturale è proporzionale al suo contenuto di uranio e al tempo trascorso dalla sua formazione. perciò la datazione con le tracce di fissione consiste nella determinazione della frazione di atomi di u238 che hanno subito la fissione nucleare. per calibrare lo sconosciuto contenuto di uranio, una frazione del campione viene irraggiata con neutroni termici in un reattore nucleare. l’irraggiamento produce la fissione indotta dell’isotopo u235: il numero di tracce rivelabili chimicamente dopo l’irraggiamento è proporzionale al contenuto di uranio. in pratica, quindi, una determinazione di età consiste nella stima di due densità superficiali di tracce – la densità di tracce fossili e la densità di tracce indotte – attraverso opportune tecniche di conteggio al microscopio. teoricamente non esistono limiti di età per l’applicazione del metodo delle tracce di fissione, ma in pratica, a causa della bassissima probabilità di verificarsi della fissione dell’u238, il contenuto di uranio di molti solidi non consente l’accumulo di un adeguato numero di tracce in tempi brevi. perciò, soltanto in casi particolari è possibile datare rocce recenti (età < 100.000 anni). benché le tracce di fissione siano state osservate in molti minerali, soltanto alcuni minerali pesanti, come ad esempio l’apatite, lo zircone e lo sfene e i vetri naturali vengono comunemente utilizzati. dato che la stabilità termica delle tracce in alcuni minerali è relativamente scarsa, l’applicazione più diffusa delle tracce di fissione è nel campo della termocronologia. particolare importanza riveste l’apatite, sia per la sua larga diffusione nelle rocce anche sedimentarie, sia per la fascia di temperature alle quali le tracce sono sensibili (da ~ 60°c a ~ 120°c). l’analisi dell’apatite con il metodo delle tracce di fissione si è rivelato un potente strumento per lo studio della storia dell’esumazione delle catene montuose o dello studio dell’evoluzione dei margini continentali. le tracce di fissione hanno fornito un contributo significativo anche nella datazione delle rocce vulcaniche, come ad esempio nello studio crono-stratigrafico in aree vulcaniche o nel campo della tefrocronologia. a questo proposito rivestono particolare importanza i vetri naturali. infatti l’unica fase databile di molti tefra consiste di una popolazione di frammenti di vetro, difficilmente databile con altre tecniche (walter, 1989). una descrizione esauriente della datazione con il metodo delle tracce di fissione e delle sue applicazioni è riportata da wagner & van den haute (1992). la cinerite di calopezzati è stata analizzata usando le metodologie messe a punto nell’istituto di geoscienze e georisorse del cnr di pisa (vedi ad esempio bigazzi et alii, 2000, espizua et alii, 2002). una frazione del vetro sx.819 è stata irraggiata con neutroni nella posizione lazy susan (rapporto cd 6,5 per au e 48 per co) del reattore del lena dell’università di pavia. dopo l’irraggiamento due frazioni del campione – una per il conteggio delle tracce fossili dovute alla fissione spontanea dell’u238 e l’altra per il conteggio delle tracce indotte dell’u235 prodotte dall’irraggiamento – sono state montate in resina epossidica, pulimentate in modo da esporre una superficie interna dei grani di vetro e attaccate per 90 s in hf 20% a 40°c per la rivelazione delle tracce. il conteggio è stato effettuato con un microscopio leica orthoplan a 500 x, utilizzando un oculare equipaggiato con una griglia, mentre le dimensioni delle tracce (l’asse maggiore degli ellissoidi che rappresentano l’intersezione delle tracce rivelate con la superficie dei grani) sono state misurate a 1000 x, utilizzando lo strumento leica-microvid accoppiato al microscopio. i risultati sono riportati in tab. 1. per il conteggio delle tracce è stata adottata la tecnica detta del “conteggio puntuale”, introdotta già negli anni ’60 (fleischer et alii, 1965), ma soltanto più recentemente utilizzata diffusamente (naeser et alii, 1982, westgate, 1989). secondo questa tecnica un campo di osservazione al microscopio viene considerato 1 se un punto di riferimento opportunamente scelto – tab. 1 tratt. termico: trattamento termico per la determinazione dell’età di plateau; ρs (ρi): densità superficiale delle tracce fossili (indotte); ns (ni): tracce fossili (indotte) contate; p(χ2): probabilità di ottenere il valore di χ2 calcolato nell’applicazione del test per confrontare la distribuzione dei conteggi delle tracce indotte con una distribuzione di poisson; ds/di: rapporto tra le dimensioni medie delle tracce fossili e indotte; età app.: età apparente; età corr.: età corretta con il metodo delle dimensioni o età di plateau. parametri usati per il calcolo dell’età: λ = 1,55125 x 10-10 a-1; λf = 8,46 x 10-17 a-1; σ = 5,802 x 10-22 cm2; 238u/235u = 137,88. la dose di neutroni, 1,53 x 1015 cm-2, è stata determinata usando il vetro standard ec-jrc-irmm-540 (de corte et alii, 1998), attraverso il conteggio di 6657 tracce sulla superficie dei detector esterni di muscovite giustapposti al vetro standard durante l’irraggiamento. gli errori sperimentali sono la propagazione degli errori di conteggio delle tracce e dell’errore introdotto dalla tecnica del conteggio puntuale (bigazzi & galbraith, 1999). tratt. termico: thermal treatment imposed for the plateau age determination; ρs (ρi) spontaneous (induced) track density; ns (ni): spontaneous (induced) track counted; p(χ2): probability of obtaining chi-square value for the induced track count distribution tested against a poisson distribution; ds/di: spontaneous to induced track size ratio; età app.: apparent age; età corr.: size-corrected or plateau age. the following parameters were used for age calculation: λ = 1.55125 x 10-10 a-1;λf = 8.46 x 10-17 a-1; σ = 5.802 x 10-22 cm2; 238u/235u = 137.88. samples were irradiated in the lazy susan (cd ratio 6.5 for au and 48 for co) facility of the triga mark ii reactor of lena, university of pavia (italy). the neutron fluence, 1.53 x 1015 cm-2, was determined using the ec-jrc-irmm-540 standard glass (de corte et al., 1998). 6657 tracks were counted on muscovite external detectors juxtaposed to the standard glass during irradiation. experimental errors are propagation of poisson counting errors and of the additional error due to the application of the point-counting technique (bigazzi & galbraith, 1999). campione ρs ns ρi ni p(χ2) ds/di età app. ± 1σ età corr. ± 1σ tratt. termico (cm-2 ) (cm-2 ) (%) (ma) (ma) sx.819 2.360 455 511.500 2.220 10 0,86 0,35 ± 0,03 0,44 ± 0,04 5h 180°c 2.222 104 372.000 512 90 1,01 0,45 ± 0,08 g. bigazzi & l. carobene 155 ad esempio il centro della griglia montata nell’oculare – si trova su una superficie di vetro utile per il conteggio, cioè su una area nella quale una traccia, se presente, sarebbe osservabile. altrimenti, cioè se il punto di riferimento si trova sulla resina o su una porzione di vetro nella quale una traccia non sarebbe identificabile, il campo è considerato 0. in questo modo il risultato finale del conteggio è una densità virtuale y/x, dove y è il numero di tracce e x è il numero dei punti su vetro. la frazione della superficie utile per il conteggio è stimata da x/n, dove n è il numero totale dei campi osservati. il conteggio puntuale consente l’analisi di superfici molto più ampie in tempi più brevi, dato che non è necessaria la stima della superficie utile dei singoli grani di vetro, tuttavia questa tecnica introduce un errore sperimentale addizionale che non può essere ignorato, anche se nel caso di basse densità di tracce questo errore può diventare anche molto modesto (bigazzi, 1999; bigazzi & galbraith, 1999). nei vetri naturali la stabilità delle tracce fossili nei tempi geologici è piuttosto scarsa: un certo tasso di cancellamento (annealing) che corrisponde a un accorciamento della lunghezza rivelabile dall’attacco chimico delle tracce stesse si produce in genere anche a temperatura ambiente. le tracce che hanno subito un certo tasso di annealing sono rivelate con efficienza ridotta. per questo motivo le età determinate con il metodo delle tracce di fissione nei vetri sono comunemente età ridotte, dette “età apparenti”, a meno che non venga applicata una tecnica di correzione. storzer & wagner (1969) hanno mostrato che la quantità di annealing può essere stimata dal rapporto tra le dimensioni delle tracce fossili e delle tracce indotte, ds/di, dove le tracce indotte sono assunte come tracce indisturbate di riferimento. una riduzione del rapporto ds/di (ds/di < 1) indica che le tracce fossili hanno subito un certo tasso di annealing, tanto più elevato quanto minore è il rapporto ds/di. il vetro sx.819 presenta un moderato tasso di annealing delle tracce fossili (ds/di = 0,86, tab. 1 e fig. 4). l’età di formazione del vetro è stata quindi stimata con il metodo delle dimensioni, utilizzando una curva di correzione delle età apparenti che mette in relazione la riduzione delle dimensioni con la corrispondente riduzione delle densità di tracce (storzer & wagner, 1969). abbiamo quindi determinato l’età di plateau, proposta da storzer & poupeau (1973) per correggere le età apparenti, che consiste nel ristabilire, attraverso trattamenti termici opportuni, una stessa efficienza di rivelazione delle tracce fossili ed indotte. seguendo la pratica comune, un solo trattamento termico è stato utilizzato in questo lavoro (arias et alii, 1981; westgate, 1989). il raggiungimento della condizione di plateau – una identica efficienza di rivelazione delle tracce fossili ed indotte – è testimoniato dal valore di ds/di, che dopo il trattamento termico diventa circa 1 (tab. 1, fig. 3). l’età corretta con il metodo delle dimensioni e l’età di plateau del campione sx.819, che sono considerate una stima affidabile dell’età di formazione del vetro, almeno nel caso di storie termiche semplici (wagner & van den haute, 1992), sono consistenti. l’età assegnata al livello piroclastico sx.819 (vedi tab. 1) permette di effettuare una possibile corrispondenza con uno dei livelli ritrovati nell’area di montalbano jonico (avanfossa bradanica dell’appennino), dove approssimativamente tra 400. e 500.000 anni ricadono ben 5 orizzonti piroclastici (v5 v6 – v7 – v8 – v9) (sezione vecchietto) (ciaranfi et alii, 2001). più preciso è il riferimento al bacino di crotone in calabria (massari et ali i, 2001), dove in località marcedusa (valle di manche) è stato riconosciuto un livello piroclastico denominato “parmenide ash” contenuto nell’unità di s. mauro, che comprende i sedimenti più recenti del riempimento del sub-bacino di s. mauro (bacino di crotone). in tale località il livello piroclastico marca praticamente l’emersione del corpo sedimentario, avvenuta “durante la fase iniziale della transizione mis 12 – mis 11” (ovvero 420. – 410.000 anni). esso si presenta composto da cinerite pura di color bianco. la coincidenza è quindi straordinaria sia per quanto riguarda l’età, sia per quanto riguarda il colore; inoltre la piccola distanza tra i due affioramenti, circa 60 km, depone a favore di una loro corrispondenza. l’età “più probabile” della cinerite del campione sx.819 potrebbe pertanto essere pari a 420.000 anni, per l’affinità con il “parmenide ash” (massari et alii, 2001). nel testo è stata comunque utilizzata l’età misurata. 4. sedimentazione, sollevamento e terrazzi marini la datazione della “cinerite di calopezzati” ha permesso di definire con buona precisione il quadro cronologico degli eventi sedimentari e del terrazzamento marino conseguente all’emersione dell’area crosiacalopezzati. tali eventi sono stati riferiti alla curva delle variazioni isotopiche dell’ossigeno (prell et alii, 1986), in quanto è ormai accettata la corrispondenza: alti eustatici interglaciali-picchi caldi climatici-massimi valori negativi del rapporto isotopico o18/o16. la sequenza sedimentaria, rilevata e campionata da carobene negli anni ’90, è purtroppo ancora priva di datazioni bio-stratigrafiche. comunicazioni verbali e l’analogia con la vicina sequenza sedimentaria di tarsia (valle del crati) (carobene et alii, 1997), unitamente allo studio dei terfig. 4 distribuzione delle dimensioni delle tracce rivelate nel vetro della cinerite di calopezzati prima (rapporto tra le dimensioni medie delle tracce fossili ed indotte ds/di = 0,86) e dopo il trattamento termico per la misura dell’età di plateau (ds/di = 1,01). size distribution of the fission tracks developed on glass shards from the calopezzati ash before (spontaneous to induced track-size ratio ds/di = 0.86) and after the thermal treatment imposed for the plateau age determination (ds/di = 1.01). datazione di un livello cineritico ... 156 razzi marini (carobene, 2003), avevano comunque permesso di ipotizzare la sua appartenenza al pleistocene medio; la datazione della cinerite ha confermato l’ipotesi, fornendo il vincolo cronologico mancante. nella fig. 5 è schematizzato il prisma sedimentario ed il terrazzamento marino; la sequenza deposizionale (descritta sommariamente in questa sede), è il risultato di una complessa sedimentazione avvenuta in un regime di subsidenza; la trasgressione è culminata in un alto stazionamento eustatico, al quale è seguita l’emersione per il perdurare di un regime di sollevamento tettonico. pertanto il prisma sedimentario è costituito da un insieme di sistemi deposizionali trasgressivi, testimoniati dai corpi sabbiosi basali illustrati in fig. 1, e da un insieme di sistemi deposizionali di alto stazionamento che, nelle parti centrali e distali del bacino hanno originato una sedimentazione prevalentemente argillosa, con spessori di centinaia di metri. da notare che, durante la fase di sollevamento, il depocentro della sedimentazione si è spostato progressivamente verso mare. nella parte medio-alta delle argille è stato rinvenuto il livello cineritico datato 450.000 anni (cap. 3); lo spessore di argille che lo sovrasta stratigraficamente è la testimonianza della sedimentazione avvenuta sicuramente durante l’alto eustatico corrispondente al mis 11 (picco massimo a 405.000 anni) e continuata per un certo periodo che verrà definito più avanti al paragr. 4.3. il nuovo regime di sollevamento tettonico causò l’emersione del prisma sedimentario prima nelle aree prossimali, successivamente nelle aree distali del bacino. i sedimenti più alti in quota, che segnano l’inizio dell’emersione, si rinvengono nell’area di crosia (fig. 1) a 277 m s.l.m. (cozzo s. pietro); essi sono costituiti da sabbie inclinate di pochi gradi verso mare, poggianti su argille mioceniche, per uno spessore di 25 m. le sabbie possono testimoniare l’ultimo alto eustatico interglaciale prima dell’emersione; a testimonianza di questo livello marino più alto vi sono crinali suborizzontali estesi verso sud fino alla quota di 300 m, sia in destra che in sinistra del fiume trionto. in corrispondenza di calopezzati il crinale si sviluppa infatti per 2200 m circa, mentre in corrispondenza di crosia lo sviluppo raggiunge i 5 km! 4.1. la datazione dei terrazzi marini per la risoluzione del problema sono stati distinti: i dati a disposizione, le ipotesi più attendibili, le relative deduzioni e, infine, le considerazioni conclusive. i dati 1) nell’area sono riconoscibili 4 ordini di terrazzi, con margine interno a 210 m (i ord.), a 105÷120 m (ii ord.), a 65÷70 m (iii ord.) e a 25÷30 m (iv ord.) s.l.m. essi sono intagliati nel substrato pleistocenico in gran parte argilloso (fig. 1). 2) il terrazzo del ii ordine (t2 in fig. 5) taglia dette argille, nelle quali è stato riconosciuto (alla quota di 45 m) il livello cineritico bianco, datato 450.000 anni ± 10% (cinerite di calopezzati). 3) lo spessore di argille che sovrasta la cinerite è attualmente valutabile in circa 100 m (±20); la misura si ricava dall’analisi della sezione geologica. 4) il substrato pleistocenico affiora (con sabbie litorali) alla quota massima di 277 m (cozzo s. pietro). 5) un esteso crinale con andamento suborizzontale si estende da tale quota verso monte per 5 km; esso potrebbe essere il relitto di una superficie di abrasione marina avente margine interno a 300 m s.l.m. 6) i depositi terrazzati del i ordine sono molto erosi. lembi relitti di calcari algali hanno fornito un’età th/u incerta ≥ 300.000 anni. 7) i depositi marini del ii e del iii ordine di terrazzi sono invece potenti, rispettivamente, fino a 40 e fino a 20 metri. 8) il terrazzo del iv ordine si presenta di ridotte dimensioni e con depositi che hanno uno spessore massimo di qualche metro. le ipotesi in base ai dati, si ritengono valide le seguenti affermazioni: 1) i terrazzi del i, ii e del iii ordine vanno riferiti a distinti e consecutivi periodi interglaciali, a loro volta correlabili a distinti mis delle curve paleoclimatiche. tale fig. 5 rappresentazione schematica dei terrazzi marini. p.l. = paleolivello marino corrispondente al top dei sedimenti; è stato attribuito al mis 11. i depositi più alti affiorano alla quota di 277 m; essi non costituiscono i depositi più recenti. c. = livello della cinerite di calopezzati rinvenuto alla quota di 45 m. t1, t2, t3, t4 = terrazzi marini attribuiti, rispettivamente, ai mis 9, 7, 5.5 e 5.1 (disegno non in scala). per notizie dettagliate vedi carobene (2003). schematic sketch of the four orders of marine terraces. p.l. = marine palaeo-level corresponding to the top of the sedimentary deposits, it was attributed to mis 11. the higher deposits crop out at an elevation of 277 m; they do not consist of the most recent sediments. c. = calopezzati ash layer, recognised at an elevation of 45 m. t1, t2, t3, t4 = marine terraces attributed to mis 9, 7, 5.5 and 5.1, respectively (non-scale drawing). see carobene (2003) for further details. g. bigazzi & l. carobene relazione è basata sulla consistente differenza altimetrica esistente tra i tre margini interni dei terrazzi, sulla grande estensione delle superfici (da 2400 a 800 metri), sullo spessore e sui caratteri stratigrafici dei depositi. 2) il terrazzo del iv ordine, viceversa, va riferito ad un substage isotopico di importanza minore, sia per la debole differenza altimetrica che lo separa dal terrazzo del iii ordine (35-40 m), sia per la sua ridotta ampiezza (inferiore a 170 m), sia per le caratteristiche dei depositi terrazzati. 3) il deposito sabbioso marino di quota 277 m ed il crinale con margine interno alla quota di 300 m testimoniano un lungo periodo di alto livello eustatico. 4) il sollevamento tettonico successivo a questo periodo interglaciale porta alla progressiva emersione del corpo sedimentario pleistocenico. 5) con il proseguire del sollevamento, il successivo periodo di alto eustatico interglaciale porta alla formazione del i ordine di terrazzi. le deduzioni 1) i 100 metri di argilla che sovrastano la cinerite sono più recenti di 450.000 anni, ma più antichi dell’interglaciale (mis) durante il quale si è formato l’ampio terrazzo del ii ordine. 2) il terrazzo del ii ordine non può essere attribuito al mis 11, con picco a 405.000 anni (ed a maggior ragione ad uno più antico), in quanto sarebbe mancato il tempo necessario alla deposizione delle argille post-cinerite. quindi non può essere più antico del mis 9. 3) il terrazzo del ii ordine non può essere attribuito al mis 5, in quanto ciò obbligherebbe ad attribuire i terrazzi del iii e del iv ordine ai substages 5.3 e 5.1. ciò contrasta col fatto che il iii ordine corrisponde in realtà ad un terrazzo molto importante, con uno spessore di depositi marini che raggiunge i 20 m e con superfici terrazzate ampie fino a 800 m. inoltre il tasso di sollevamento del terrazzo del i i ordine (attribuito al mis 5) risulterebbe quasi doppio di quello degli ordini iii e iv. l’origine del terrazzo del ii ordine va quindi attribuita o al mis 7 o al mis 9. 4) l’attribuzione del terrazzo del ii ordine al mis 9 comporterebbe invece: che la deposizione delle argille post-cinerite (spessore circa 100 m), tagliate dal terrazzo del ii ordine, sia avvenuta nell’intervallo di tempo tra 450.000 anni e la fine dell’alto eustatico (circa 370.000 anni fa) corrispondente al mis 11; che il terrazzo del iii ordine venga attribuito di conseguenza al mis 7; che il terrazzo del iv ordine venga attribuito al mis 5. queste tre possibilità sono poco probabili; la prima comporta infatti che la deposizione dei 100 m di argilla sia avvenuta in un arco di tempo breve, durante l’alto eustatico interglaciale corrispondente al mis 11, con una batimetria che andava rapidamente diminuendo durante la fase finale dello stage, fino ad annullarsi; ciò a causa dell’abbassamento eustatico e dell’avvenuta sedimentazione. la terza possibilità va esclusa per quanto già detto sopra (ipotesi 2); ciò esclude la possibilità due. pertanto si può dedurre, in base ai dati a disposizione, che l’attribuzione al mis 7 del terrazzo del ii ordine sia la più attendibile. le considerazioni conclusive l’attribuzione del terrazzo del ii ordine al mis 7, comporta che il i ordine vada riferito al mis 9 e l’emersione dell’area al mis 11. è probabile che l’emersione abbia avuto inizio già durante o subito alla fine del mis 11, a causa di un regime di sollevamento cominciato da qualche tempo. il cambiamento di regime tettonico, dalla fase subsidente a quella di sollevamento, determina un periodo di stasi tettonica che probabilmente si somma al periodo dell’alto eustatico interglaciale mis 11, manifestatosi tra 370. e 415.000 anni fa circa, con picco massimo a 405.000 anni (substage 11.3). ciò può spiegare la formazione dell’ampia superficie di erosione, la cui testimonianza è oggi un crinale suborizzontale esteso fino a 5 km (vedi sopra) e fino alla quota di 300 m. l’assenza di terrazzi a quota più elevata esclude che il sollevamento sia iniziato precedentemente. lo schema di fig. 6 sintetizza le fasi del sollevamento dell’area e del conseguente terrazzamento marino, avvenute posteriormente alla deposizione del livello cineritico sx.819. 157 fig. 6 schema che sintetizza le fasi dell’emersione del corpo sedimentario pleistocenico, del suo sollevamento ed il conseguente terrazzamento marino (b). l’emersione avviene con la fine del mis 11, che corrisponde ai sedimenti più alti in quota; il i ordine di terrazzi si forma in corrispondenza del mis 9; il ii ordine corrisponde al mis 7; il iii ordine al mis 5.5; il iv ordine al mis 5.1. il periodo della subsidenza (a) è stato ipotizzato in base al tasso di sedimentazione medio, considerato pari a 0,6 mm/a ± 30% (paragr. 4.3). sketch synthesizing the emersion phases of the pleistocene sedimentary body, of its uplift and of the consequent marine terracing (b). emersion occurred with the end of mis 11, which corresponds to the sediments located at higher elevation. the 1st order of terraces formed connected with mis 9, whereas the 2nd, 3rd and 4th orders correspond to mis 7, mis 5.5 and mis 5.1, respectively. the subsidence period (a) was hypothesised through an estimated average sedimentation rate of 0,6 mm/a ± 30% (see paragr. 4.3). datazione di un livello cineritico ... terrazzo del i ordine. si forma durante il mis 9, manifestatosi tra 280. e 335.000 anni fa, con picco massimo a 330.000 anni (substage 9.3). sia l’ampiezza (fino a 2500 metri), sia il dislivello in quota tra margine interno (210 m) e orlo esterno (130 m), indicano che alla costruzione della superficie terrazzata hanno contribuito gli alti eustatici dei substages (due o tre, a seconda delle curve isotopiche) appartenenti all’intero stage isotopico 9. al dislivello sopra evidenziato hanno contribuito in parte anche le faglie, attivatesi in questa prima fase di forte sollevamento. terrazzo del ii ordine. essendo il terrazzo immediatamente più basso, è stato riferito al mis 7; questo lungo periodo interglaciale, esteso tra 185. e 245.000 anni, è caratterizzato da 3 – 4 substages; dalle curve isotopiche o dei paleolivelli di stazionamento del mare non si evince in modo univoco qual’è stato il picco più importante (chappell & shackleton, 1986; waelbroeck et alii, 2002; williams et alii, 1988; winograd et alii, 1997, ecc.). in questa sede pertanto si attribuisce al picco maggiore del mis 7 un’età intermedia di 220.000 anni; tale valore è probabilmente affetto da un errore del ±10% circa. la quota attuale del margine interno del terrazzo è a 105÷120 m. terrazzo del iii ordine. è riferibile al successivo interglaciale mis 5, che si è sviluppato tra 80. e 135.000 anni. in questo caso però il terrazzo va attribuito al picco massimo centrato a 125.000 anni (substage 5.5, con durata di almeno 10.000 anni) per almeno due ragioni: 1) la sua ampiezza e lo spessore di depositi che lo caratterizza sono sensibilmente più ridotti rispetto ai terrazzi più alti; 2) esiste un iv ordine di terrazzi, più basso in quota, che deve essere attribuito ad un alto eustatico successivo appartenente al mis 5 (vedi avanti). il margine interno è alla quota di 65÷70 m. terrazzo del iv ordine. ha margine interno alla quota di 25÷30 m, ampiezza molto ridotta rispetto ai precedenti e uno spessore di sedimenti debole e a volte mancante. la sua attribuzione al 5.1 anziché al 5.3 è ritenuta più probabile, in quanto l’ultimo terrazzamento è generalmente il meglio conservato. 4.2. ipotesi sulle velocità di sollevamento la cronologia degli eventi sopra esposta permette di effettuare calcoli sulle velocità di sollevamento riferite sia al livello di chiusura (nella parte a monte) del prisma sedimentario che costituisce il substrato, sia dei quattro ordini di terrazzi che lo incidono a quote più basse. per i calcoli si fa riferimento alla cronologia delle curve delle paleotemperature degli isotopi dell’ossigeno. per valutare il sollevamento effettivo si è inoltre tenuto conto della probabile paleoquota dei singoli alti livelli interglaciali, desunta da vari autori (aharon & chappell, 1986; bender et alii, 1979; chappell & shackleton, 1986; dodge et alii, 1983; mush et alii, 1994; pirazzoli et alii, 1991; shackleton, 1987; williams et alii, 1998). nella colonna 8 della tab. 2 è riportato il tasso medio di sollevamento. il picco interglaciale più alto (mis 11), successivo alla cinerite sx.819, ha avuto il suo massimo a 405.000 anni; un lembo relitto di sedimenti del substrato è riconoscibile alla quota di 277 m (cozzo s. pietro), mentre il crinale suborizzontale esteso a monte ha il margine interno alla quota di 300 m. il tasso medio di sollevamento calcolato è pari a 0,69 mm/a. il picco interglaciale immediatamente più basso (mis 9) ha il suo massimo a 330.000 anni; la quota attuale del margine interno del terrazzo corrispondente è a 210 m. il tasso di sollevamento medio risultante è di 0,62 mm/a. il picco interglaciale successivo (mis 7) ha il suo massimo a 220.000 anni; la quota attuale del margine interno del corrispondente terrazzo è a 105÷120 m. il tasso di sollevamento medio è di 0,56 mm/a. il picco interglaciale (mis 5.5) ha avuto il suo massimo a 125.000; la quota del margine interno del terrazzo è a 64÷71 m. il tasso di sollevamento risultante è di 0,50 mm/a. il terrazzo più basso, con margine interno a 25÷30 m, viene fatto corrispondere al sottostadio mis 5.1, che ha avuto il suo massimo circa 82.000 anni fa. la velocità di sollevamento è pari a 0,46 mm/a. la tab. 2 riassume i valori sopra esposti; si ritiene che le età riportate in col. 3 siano affette da un errore del 5-10%. nella col. 5 sono riportati i presunti valori delle paleoquote di stazionamento diverse dall’attuale livello del mare, desunte dalla bibliografia (vedi carobene, 2003, cap. 3); questi valori sono sicuramente affetti da un errore che, in questa sede, è stato ritenuto pari a ±5÷10 m. si può osservare (col. 8) che i tassi diminuiscono da 0,69 a 0,46 mm/a, dal livello più antico al livello più recente; ciò è coerente con il quadro tettonico dell’area (carobene, 2003), dove l’attività di faglie quaternarie ha sollevato maggiormente la zona a monte, con rigetti di alcune decine di metri. non si può escludere tuttavia che le velocità iniziali di sollevamento siano andate leggermente scemando nel tempo. in ogni caso, sulla base degli errori che affliggono i dati delle colonne 3 (età) e 5 (paleoquote), è stata calcolata la variabilità dei tassi di sollevamento (tab. 2 col. 9 e fig. 7). 4.3. ipotesi sulle velocità di sedimentazione la datazione dei terrazzi sopra riportata permette di effettuare anche un calcolo della velocità media di sedimentazione delle argille che si sono deposte al di sopra del livello cineritico sx.819; lo spessore, calcolato in base a ricostruzioni geometriche basate sulla inclinazione degli strati, risulta di circa 100 metri ±20 m. la successiva formazione dei terrazzi marini ha intagliato il corpo argilloso, asportandovi la parte superiore, tanto che oggi l’orizzonte cineritico è stato rinvenuto, alla quota di 45 m, al di sotto della superficie terrazzata del ii ordine (che localmente presenta la quota massima a 95 metri) (vedi cap. 3). si dimostra che la deposizione dei 100 m di argilla sovrastanti la cinerite terminò con l’alto eustatico corrispondente al mis. 9, durante il quale la batimetria del fondo marino (in corrispondenza della cinerite ) non superava i 65 m circa (fig. 8 – a). tale valore di profondità era compatibile con la sedimentazione argillosa; successivamente (con l’abbassamento eustatico e con il proseguire del sollevamento dell’area), le condizioni non furono più favorevoli alla sedimentazione. infatti, durante il mis 7 il mare intagliava già il corpo argilloso, essendo più basso del top dei sedimenti (fig. 8 – b). si può pertanto concludere che la sedimentazione (in quel punto) deve essersi necessariamente conclusa con la 158 g. bigazzi & l. carobene pari a 0,6 mm/a circa. il valore così ritrovato è sicuramente afflitto da errori derivanti dalla incertezza del reale spessore di argille post-cinerite, dalla reale durata della deposizione e dalla variabilità del tasso di sedimentazione durante glaciali e interglaciali, per cui si è calcolata una variabilità compresa tra 0,4 e 0,8 mm/a. il valore di 0,6 mm/a fornisce tuttavia utili indicazioni per ricavare l’età della colonna stratigrafica di fig. 1. lo spessore calcolato di oltre 400 m (confermato da un pozzo presente in zona di 330 m completamente in argille!), permette di ipotizzare che la sequenza sedimentaria si sia deposta in un periodo di 635.000 anni, tenendo costante il tasso di 0,6 mm/a. l’inizio della sedimentazione risalirebbe quindi a 985.000 anni fa circa (170.+535.+280.000); tenendo conto di errori o incertezze, il campo di variabilità si estende da 800. a 1.200.000 anni circa). ciò è coerente con quanto dedotto dallo studio della successione pleistocenica di tarsia nella valle del crati (carobene et alii, 1997), che ha uno spessore complessivo di 210 m circa, essendosi deposta con un regime di minor subsidenza. in base a datazioni basate su foraminiferi, ostracodi e nannoplancton 159 tab. 2 dati relativi ai 4 ordini di terrazzi marini e al top del corpo sedimentario pleistocenico, che costituisce il substrato. il sollevamento medio (col. 8) subito dai terrazzi è stato calcolato tenendo conto dei sollevamenti effettivi (col. 6) e mediando i valori della col. 7. la col. 9 riporta la variabilità dei tassi di sollevamento causata sia dalle differenze di quota del m.i. dei terrazzi (col. 2), sia dell’incertezza delle quote originarie dei paleostazionamenti (col. 5). data related to the four orders of marine terraces and to the top of the pleistocene sedimentary body, which constitutes the substratum. the average uplift (col. 8) experienced by the terraces was computed taking into account the real uplift amounts (col. 6) and averaging the uplift rate values shown in col. 7. the variability of the average uplift rates owing to both the elevation differences of the inner margin (m.i.) of the terraces (col. 2), as well as to the uncertainties related to the original elevation of the palaeo-standing phases (col. 5) is shown in col. 9. 1 2 3 4 5 6 7 8 9 elemento quota m.i. età mis quota solletassi tasso variabilità considerato s.l.m. del picco curva probabile dei vamento di sollemedio dei tassi dovuta più alto paleotempaleostazionavamento agli errori (metri) (annix1000) perature menti (metri) (metri) (mm/anno) (mm/anno) (mm/anno) top 277 ÷ 300 405 11.3 + 10 ? 267 ÷ 290 0,66 ÷ 0,72 0,69 0,65 ÷ 0,80 sedimentazione i ordine terrazzi 210 330 9.3 + 5 ? 205 0,62 0,62 0,58 ÷ 0,70 ii ordine terrazzi 105 ÷120 220 7.3 10 ? 115 ÷ 130 0,52 ÷ 0,59 0,56 0,45 ÷ 0,65 iii ordine terrazzi 65 ÷ 70 125 5.5 + 5 ? 60 ÷ 65 0,48 ÷ 0,52 0,50 0,38 ÷ 0,58 iv ordine terrazzi 25 ÷ 30 82 5.1 10 ? 35 ÷ 40 0,43 ÷ 0,49 0,46 0,35 ÷ 0,55 fig. 7 il tasso medio di sollevamento dell’area decresce da 0,69 a 0,46 mm/a. il campo di variabilità attribuito ai singoli valori è stato calcolato: 1) in base alla variabilità della quota del margine interno dei terrazzi (m.i.); 2) in base all’errore (circa 10.000 anni) che si fa nell’attribuire una età ben precisa ai mis e 3) in base ad un errore nella valutazione della paleoquota originaria dei massimi livelli interglaciali (circa ± 10 m). the average uplift rate of the area decreased from 0.69 down to 0.46 mm/a. the variability interval of the individual uplift rate values was estimated taking into account 1) the variability of the elevation of the terrace inner margin (m.i.), 2) the uncertainty related to the attribution of a given numerical value to the age of a certain mis (around 10,000 years) and 3) the error of the estimate of the original palaeo-elevation of the maximum inter-glacial levels (around ± 10 m). fine dell’alto stazionamento corrispondente al mis 9, ovvero 300.-280.000 anni fa (al massimo). i 100 m di argilla sovrastanti la cinerite si sarebbero deposti in un arco di tempo non superiore a 170.000 anni (da 450. a 280.000 anni), con velocità media di sedimentazione datazione di un livello cineritico ... calcareo, l’intera successione di tarsia è stata infatti attribuita al pleistocene medio (“ioniano” in cita & castradori, 1995). nel caso della successione di crosia-calopezzati non è in realtà conosciuta la base della successione nella parte mediodistale, per cui non si può escludere una sua continuità di sedimentazione con il pleistocene inferiore. inoltre la superficie trasgressiva è diacrona, per cui il valore calcolato è valido sulla verticale del livello cineritico. 5. conclusioni nell’area di crosiacalopezzati, in destra del fiume trionto in calabria, affiora una successione marina pleistocenica trasgressiva (almeno nella parte prossimale) sul substrato miocenico. essa è il risultato di una fase di abbassamento del margine ionico, che ha originato importanti bacini di sedimentazione in calabria e in basilicata; il loro studio ha già fornito risultati rilevanti per la conoscenza del pleistocene inferiore e medio. per il bacino crotonese si segnala massari et alii (2001, cum bibl. ) e massari et al i i (2002) e per il bacino lucano ciaranfi et alii (2001, cum bibl.). nel bacino di crosiacalopezzati sono stati studiati i terrazzi marini legati al sollevamento dell’area (carobene, 2003), mentre lo studio del substrato è ancora in corso. il rinvenimento di un livello cineritico (“cinerite di calopezzati”) nelle argille del substrato, e la sua datazione con il metodo delle tracce di fissione, ha tuttavia permesso di effettuare considerazioni sul tasso di sedimentazione e, quindi, di avanzare ipotesi sull’inizio della sedimentazione del corpo trasgressivo che costituisce il substrato; si è inoltre potuto definire con buona sicurezza il momento della sua emersione, l’età dei terrazzi marini e le velocità di sollevamento dell’area. la successione degli eventi è sintetizzabile nei seguenti punti: 1) abbassamento dell’area costiera (subsidenza) e inizio della sedimentazione pleistocenica. utilizzando la presenza del livello cineritico datato con le tracce di fissione, e in base allo spessore di argille sovrastanti, è stato ipotizzato un tasso medio di sedimentazione pari a 0,6 mm/a. (cap. 4.); con riferimento allo spessore calcolato del prisma sedimentario, (colonna di fig. 2) la sedimentazione avrebbe avuto inizio con la fine del pleistocene inferiore inizio pleistocene medio (fig. 9 – col. 2). poiché la sommersione è stata diacrona, il dato si riferisce al punto sulla verticale del livello cineritico datato (ciò vale anche per altre considerazioni successive). 2) sedimentazione e oscillazioni eustatiche. la sedimentazione è cessata con la fine del mis 9 (280.000 anni fa) (vedi paragr. 4.1 e fig. 9 – col. 2). durante la deposizione del corpo sedimentario costituente il substrato pleistocenico dell’area, il livello del mare ha subito importanti e numerose oscillazioni glacioeustatiche, per cui il corpo è in realtà una somma di sequenze sedimentarie legate alle trasgressioni, agli alti stazionamenti e alle regressioni. ciò è solo parzialmente visibile in fig. 2; la sedimentazione “ciclica”, legata cioè alle oscillazioni glacioeustatiche, è invece stata ben documentata a tarsia (valle 160 fig. 8 ricostruzione degli alti livelli interglaciali relativi ai mis 9 e 7, basata sulle quote attuali (tra parentesi). a) durante lo stazionamento 9.3 (330.000 anni fa), la sedimentazione argillosa sulla verticale del punto di affioramento del livello cineritico era ancora possibile. essendo lo spessore calcolato (s) di argille al di sopra della cinerite pari a circa 100 m, la sua attuale quota corrisponderebbe a 145 m (tra parentesi) che, confrontata con il valore del paleolivello del mis 9.3 (oggi alla quota di 210 m), fornisce una batimetria di 65 m (vedi paragr. 4.3). b) durante lo stazionamento 7.3 (220.000 anni fa) il mare intagliava invece il substrato argilloso al di sopra del livello cineritico; ciò ha dato origine al terrazzo del ii ordine, con margine interno (m.i.) alla quota attuale di 110 m circa (tra parentesi). nota: le paleoquote dei livelli 9 e 7 sono state considerate per semplicità uguali a quelle attuali. reconstruction of the inter-glacial high levels related to mis 9 and 7, based on the present day elevations (in brackets). a) during the 9.3 marine highstand phase (330,000 years ago), the clayey sedimentation along the vertical over the ash outcropping place was still possible. since the estimated thickness (s) of the clay deposits overhanging the ash level is around 100 m, its present day elevation should correspond to 145 m (in brackets). comparing this value with that one corresponding to the palaeo-level of mis 9.3 (nowadays at an elevation of 210 m), one can deduce a bathymetry of 65 m (see paragr. 4.3). b) on the contrary, during the 7.3 marine highstand phase (220,000 year ago), the sea incised the clayey substratum over the ash level. that arrangement originated the 2nd order of terraces, with inner margin (m.i.) at a present-day elevation of around 110 m (in brackets). n.b.: for simplicity, the palaeo-elevations of levels 9 and 7 have been considered equal to the present day elevations. g. bigazzi & l. carobene del crati – cosenza) da carobene et alii (1997). l’intera successione di tarsia è stata attribuita al pleistocene medio in base alla biostratigrafia basata su nannofossili, foraminiferi e ostracofauna. vi sono riconoscibili 5 sequenze deposizionali sovrapposte (ciclotemi); i sedimenti dell’ultima sequenza affiorano alla quota massima di 311 m; il terrazzo marino più alto che incide il corpo sedimentario ha il margine interno a 260÷270 m s.l.m. poiché la 4° sequenza è “più recente di 0,584 ma”, è molto probabile che essa appartenga al picco eustatico dello stage 13; di conseguenza, la 5° sequenza (la più alta) appartiene verosimilmente allo stage 11; il terrazzo a +260÷270 m (il primo a formarsi con l’emersione) può con molta probabilità essere attribuito allo stage 9. ciò rende la successione di tarsia perfettamente corrispondente a quella di crosia-calopezzati. 3) inizio del sollevamento tettonico. si può far coincidere con la deposizione della cinerite, per cui è collocabile circa 450.000 anni fa (fig. 6 – a e fig. 9 – col. 4). esso precede infatti l’alto eustatico del mis 11 (vedi punto successivo). 4) emersione del prisma sedimentario. ovviamente l’emersione è diacrona e procede da monte verso mare; essa si manifesta con evidenza in coincidenza dell’abbassamento eustatico successivo al picco 161 fig. 9 relazioni cronologiche conclusive tra curva isotopica (col. 1) (prell, 1986 in bradley, 1999 – fig. 6.11) e la successione pleistocenica (col. 2); le date di inizio (a) e di fine sedimentazione (c) sono state ricavate indirettamente in base alla datazione della cinerite (b); col. 3 = età dei quattro ordini di terrazzi marini; col. 4 = movimenti verticali dell’area; b indica il passaggio tra il regime di abbassamento e quello di sollevamento. a indica l’inizio della sedimentazione della successione stratigrafica considerata, ma non necessariamente l’inizio della subsidenza; tale inizio (a) è basato su una “velocità di sedimentazione” costante pari a 0,6 mm/a (paragr. 4.3.). la fine della sedimentazione (c) è direttamente legata allo sviluppo delle superfici terrazzate (fig. 8). conclusive chronological relationships between isotopic curve (col. 1) (after bradley, 1999 – fig. 6.11) and the pleistocene succession (col. 2); the ages of the onset (a) and of the end of the sedimentation (c) have been estimated based on the age determined on the ash level (b); col. 3 = age of the four orders of marine terraces; col. 4 = vertical movements of the study area; b indicates the transition from a subsidence to a uplift framework; a indicates the onset of the sedimentation of the studied stratigraphic succession, but not necessarily the onset of the subsidence phase. datazione di un livello cineritico ... interglaciale del mis 11 (fig. 9 – col. 3). e’ testimoniata dai sedimenti più alti in quota (277 m) (fig. 5). 5) sollevamento tettonico e 1° terrazzamento marino. il tasso di sollevamento diventa inizialmente forte (circa 1 mm/a); l’alto livello interglaciale successivo, attribuito al mis 9 (cap. 4) si posiziona 70-80 m più in basso, originando un ampio terrazzo, oggi ampiamente rimodellato e con margine interno a 210 m (fig. 5 e fig. 9 – col. 3). un campione di calcare algale ha fornito un’età th/u ≥ 300.000 anni (carobene, 2003). il tasso di sollevamento medio risulta di 0,62 mm/a. durante questo alto eustatico la sedimentazione argillosa prosegue al largo, contribuendo a ultimare lo spessore di argille (circa 100 m) che sovrastano il livello cineritico datato. si assume che la sedimentazione cessi con il successivo abbassamento eustatico (fig. 8 – a e b). 6) sollevamento e 2° terrazzamento marino. un importante alto livello eustatico interglaciale (mis 7) determina la formazione del terrazzo del ii ordine, oggi con margine interno a 105÷120 m (cap. 4) (fig. 9 – col. 3). il mare crea una estesa superficie di abrasione nelle argille precedentemente depostesi, sulla quale si depositano 35 m di depositi marini, riferibili ad un sistema trasgressivo e ad un sistema di alto stazionamento. il sollevamento tettonico e l’abbassamento eustatico relativo al mis 6 determinano un rapido abbandono del terrazzo. il tasso di sollevamento medio del terrazzo risulta pari a 0,56 mm/a (tab. 2). 7) sollevamento e 3° terrazzamento marino. un successivo importante picco eustatico interglaciale, corrispondente al mis 5.5, origina il terrazzo del iii ordine, con margine interno attualmente a 65÷70 m circa (fig. 9 – col. 3). sulla superficie di erosione basale, tagliata nelle argille del substrato, poggiano 25 m di sedimenti marini e continentali. il tasso di sollevamento medio è pari a 0,50 mm/a (tab. 2). 8) sollevamento e 4° terrazzamento marino. l’ultimo alto eustatico dello stadio 5 (mis 5.1) determina il terrazzo del iv ordine (fig. 9 – col. 3), minore dei precedenti per ampiezza e per spessore dei sedimenti. la quota attuale del margine interno, pari a 25÷30 m, permette di ricavare un tasso medio di sollevamento di 0,46 mm/a. la successione cronologica dei 4 ordini di terrazzi e del top dei sedimenti evidenzia un regolare andamento del sollevamento (fig. 6 – b), leggermente calante nel tempo (da 0,69 a 0,46 mm/a) (tab. 2). il dato è in buon accordo con i valori dedotti da studi a carattere generale (ciaranfi et alii, 1983), e da ricerche condotte in aree limitrofe (belluomini et alii, 1988, carobene et alii, 1997, cucci e cinti, 1998, palmentola et alii, 1990). tenendo conto delle incertezze nell’attribuzione delle età dei paleostazionamenti più alti e della loro quota originaria, è stato possibile calcolare l’intervallo di variabilità dei tassi di sollevamento riportato in fig. 7. per concludere, la successione di crosiacalopezzati, tarata mediante “la cinerite di calopezzati”, documenta la sedimentazione marina del pleistocene medio almeno fino allo stage 9; i 4 ordini di terrazzi marini rinvenuti documentano invece il sollevamento e la progressiva emersione dell’area. ringraziamenti ricerca finanziata con fondi del progetto di ateneo 2001, università di genova (responsabile luigi carobene). si ringrazia il prof. francesco massari (università di padova) per gli utili suggerimenti. un ringraziamento va al sig. pio novelli (università di pisa) per l’accurata preparazione dei campioni destinati all’analisi con il metodo delle tracce di fissione e al dott. cristiano queirolo (università di genova) per il supporto tecnico nell’informatizzazione dei dati. un grazie infine al prof. neri ciaranfi per la rigorosa revisione. bibliografia citata aharon p. & chappell j. (1986) oxygen isotopes, sea level changes and the temperature history of a coral reef environment in new guinea over the last 105 years . palaeogeogr. palaeoclimatol. palaeoecol., 56 (3/4), 337-379. arias c., bigazzi g. & bonadonna, fp. (1981) size correction and plateau age in glass shards. nucl. tracks radiat. meas, 5, 129-136. belluomini g., gliozzi e. & ruggieri g. e di branca m., delitala l. (1988) first dates on the terraces of the crotone peninsula (calabria, southern italy). boll. soc. geol. it., 107, 249-254. bender m.l., fairbanks r.g., taylor f.w., matthews r.k., goddard j.g. & broecker w.s. (1979) uranium-series dating of the pleistocene reef tracts of barbados, west indies. geol. soc. am. bull., 90 (6), 577-594. bigazzi g. & galbraith r. (1999) point-counting technique for fission-track dating of tephra glass shards, and its relative standard error. quat. res, 51, 6773. bigazzi g. (1999) alternative track-counting strategies: short notes on precision and accuracy. mem. scienze geologiche, 51, 446-448. bigazzi g., bonadonna f.p., centamore e., leone g., mozzi m., nisio s. & zanchetta g. (2000) new radiometric dating of volcanic ash layers in periadriatic foredeep basin system, italy. palaeo. palaeo. palaeo., 155, 327-340. carobene l., colalongo m. l., pasini g. & raffi i. (1997) sequenze deposizionali del pleistocene medio nella valle del fiume crati presso tarsia (calabria). boll. soc. geol. it., 116 (1997), 503-524. carobene l. (2003) genesi, età, sollevamento ed erosione dei terrazzi marini di crosia-calopezzati (costa ionica della calabria – italia). il quaternario, 16 (1), 43-90. chappell j. & shackleton n.j. (1986) oxygen isotopes and sea level. nature, 324 (13 nov.), 137-140. ciaranfi n., guida m., iaccarino g., pescatore t., pieri p., rapisardi l., ricchetti g., sgrosso g., torre m., tortorici l., turco e. e di scarpa r., cuscito m., guerra i., iannaccone g., panza g.f. & scandone p. (1983) elementi sismotettonici dell’appennino meridionale. boll. soc. geol. it., 102, 201-222. 162 g. bigazzi & l. carobene ciaranfi n., d’alessandro a, girone a., maiorano p., marino m., soldati d. & stefanelli s. (2001) pleistocene sections in the montalbano jonico area and the potential gssp for early-middle pleistocene in the lucania basin (southern italy). mem. scienze geologiche, 53, 67-83, padova. cita m.b. & castradori d. (1995) workshop on marine sections from the gulf of taranto (southern italy) usable as potential stratotypes for the gssp of the lower, middle and upper pleistocene. il quaternario, 7 (2), 1994, 677-692. cucci l. & cinti f.r. (1998) studio dei terrazzi marini dell’alto ionio cosentino: considerazioni su sollevamento regionale e deformazione tettonica locale. il quaternario, 10 (2) (1997), 549-556. de corte f., bellemans f., van den haute p., ingelbrecht c. & nicholl c. (1998) a new u doped glass certified by the european commission for the calibration of fission-track dating. in van den haute p. & de corte f. (ed.), advances in fission-track geochronology. kluwer academic publishers, dordrecht. 67-78. dodge r.e., fairbanks r.g., benninger l.k. & maurasse f. (1983) pleistocene sea levels from raised coral reefs of haiti. science, 219 (4591), 1423-1425. espizua l.e., bigazzi g., iunes p.j., hadler j.c. & osorio a.m. (2002) fission-track dating of a tephra layer related to poti-malal and seguo drifts in the rio grande basin, mendoza, argentina. j. quat. sci., 17, 781-788. fleischer r. l., price p.b., walker r.m. & leakey l.s.b. (1965) fission track dating of bed i, olduvai gorge. science, 148, 72-74. massari f., rio d., sgavetti m., asioli a., backman j., capraro l., d’alessandro a., fornaciari e. & prosser g. (2001) the middle pleistocene of the crotone basin. mem. scienze geologiche, 53, 85112, padova. massari f., rio d., sgavetti m., prosser g., d’alessandro a., asioli a., capraro l., fornaciari e. & tateo f. (2002) interplay between tectonics and glacio-eustasy: pleistocene succession of the crotone basin, calabria (southern italy). gsa bullettin, 114 (10), 1183-1209. mush d. r., kennedy g. l. & rockwell t. k. (1994) uranium-series ages of marine terrace corals from the pacific coast of north america and implications foe last-interglacial sea level history. qatern. res., 42, 72-87. naeser n.d., westgate j.a., hugens o. & péwé t.l. (1982) fission-track ages of late cenozoic distal tephra beds in the yukon territory and alaska. can. j. earth sci , 19, 2167-2178. palmentola g., carobene l., mastronuzzi g. & sansò p. (1990) i terrazzi marini pleistocenici della penisola di crotone (calabria). geogr. fis. dinam. quat., 13 (1), 75-80. panizza m. (1967) il pleistocene di crosia (rossano, cosenza). riv. it. paleont. stratigr., mem. 13, 131194. pirazzoli p. a., radtke u., hantoro w.s., jouannic c., hoang c.t., causse c. & borel best m. (i991) quaternary raised coral-reef terraces on sumba island, indonesia. science, 252, 1834-1836. prell w.l., imbrie j., martinson d.g., morley j.j., pisias n.g., shackleton n.j. & streeter h.f. (1986) graphic correlation of oxygen isotope stratigraphy: application to the late quaternary . paleoceanography, 1, 137-182. shackleton n. j. (1987) oxygen isotopes, ice volume and sea level. quatern.sc.rev., 6 (3/4), 183-190. storzer d. & poupeau g. (1973) ages-plateau de mineraux et verres par la method des traces de fission. c. r. paris, 276 serie d, 317-319. storzer d. & wagner g.a. (1969) correction of thermally lowered fission-track ages of tektites. earth planet. sci. lett., 5, 463-468. waelbroeck c., labeyrie l., michel e., duplessy j.c., mcmanus j.f., lambeck k., balbon e. & labracherie m. (2002) sea-level and deep water temperature changes derived from benthic foraminifera isotopic records. quaternary science reviews, 21, 295-305. wagner g.a. & van den haute p. (1992) fission track dating. kluwer academic publishers, dordrecht. 285 pp. westgate j.a. (1989) isothermal plateau fission track ages of hydrated glass shards from silicic tephra beds. earth planet. sci. lett., 95, 226-234. williams d. f., thunell r. c., tappa e., rio d. & raffi i. (1988) chronology of the pleistocene oxygen isotope record: 0-1.88 m/y. b.p. palaeogeogr., palaeoclimat., palaeoecol., 64, 221-240. williams m., dunkerley d., de deckker p., kershaw p. & chappell j. (1998) quaternary environments. 329 pp., arnold, london. winograd i.j., landwehr j.m., ludwig k.r., coplen t.b. & riggs a.c. (1997) duration and structure of the past four interglaciations. quatern. res., 48, 141-154. 163 ms. ricevuto il 1° giugno 2004 testo definitivo ricevuto il 25 ottobre 2004 ms. received: june 1, 2004 final text received: october 25, 2004. datazione di un livello cineritico ... lakonis, and kalamakia. some of these sites remain central to debate regarding the latest presence of neanderthals in europe and the mediterranean basin, as continuous updates to chronological, archaeological, and palaeoanthropological records (higham et al., 2014; mihailović, 2020; déviese et al., 2017; tourloukis, 2021; karavanić et al., 2024). from this perspective, the region bordering the eastern adriatic and ionian seas, with its diverse geographic, climatic, and ecological characteristics including coastal plains, rolling hills, and mountain ranges reaching elevations of 2,600-2,700 m a.s.l. deserves consideration as an area that has witnessed significant population movements since the middle pleistocene. its rugged terrain, intersected by major se-nw orientated fluvial valleys connecting the southernmost part of the balkans with the adriatic region, may have provided refugia for temperate species and favoured pleistocene zoogeographic diversity from the earliest times (palombo & mussi, 2006). however, given the scarcity of middle palaeolithic sites in this region, our current understanding of neanderthal occupations, locations, territories, and adaptations to environmental and ecological diversity remains limited. it is expected that neanderthals adapted to this geographic diversity through varying mobility strategies and technological traditions, resulting in a cultural mosaic featured by a mix of expedient and curated technologies, shifts between continuity and disruption in different productions available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 38 (1), 2025, 5-30 https://doi.org/10.26382/amq.2025.01 1. introduction. the middle palaeolithic settlements of the western balkans: a biased scenario ? southern europe was extensively inhabited by neanderthals during the late middle pleistocene and late pleistocene. however, despite the available evidence indicating variability in settlement patterns and mobility strategies, the reconstruction of neanderthals cultures and adaptive behaviours remains biased. among the three peninsulas forming this part of europe iberian, italian, and balkan (romagnoli et al., 2022) the balkan peninsula, particularly its south-westernmost region, records a low number of mousterian sites, whether single-layered or multi-layered. these sites are located along the fringes of the great adriatic po region (peresani et al., 2021) and the ionian region, as well as in the mountain ranges of dinarids and epirus, extending to the southernmost greek peninsula (dogandžić, 2023; galanidou & papoulia, 2023; karavanić & banda, 2023). cave sites are also present in the mountainous area at the southern periphery of the pannonian basin (mihailović, 2020), while open-air sites are clustered along the main river basins of the sava, drina, and morava. currently, the most extensively investigated sites from north to south include krapina, vindija cave, mujina pećina, pešturina, kozarnika, crvena stijena, bioče, theopetra, asprochaliko, klissoura, middle palaeolithic in southern albania: perspectives from the lithic industry of the istraishta site rudenc ruka 1, michele bassetti 2, stefano bertola 3, davide delpiano 3, ilirjan gjipali 1, marco peresani 3, 4 1 prehistory department, institute of archaeology, academy of albanological studies, tirana, albania. 2 cora ricerche archeologiche, trento, italy. 3 university of ferrara, department of humanities, prehistoric and anthropological sciences unit, ferrara, italy. 4 cnr, igag, stratigraphic, vegetation, climate and man research group, lab. palinology and palaeoecology, milano, italy. corresponding author: marco peresani <marco.peresani@unife.it> abstract: neanderthal groups developed diverse mobility patterns and resource exploitation strategies across their territories. these variations are linked to different knapping methods and are likely to reflect adaptive strategies and responses at multiple ecological and cultural levels. neanderthals associated with discoid knapping are known to depend on context-specific, unplanned exploitation of lithic raw materials for daily subsistence and tend to be more mobile than those using different technologies. however, well-defined data are lacking for many geographical regions where this technocomplex has been identified. this study presents the open-air site of istraishta, where the mousterian industry is characterised by discoid technology applied to the reduction of pebbles, thin plates, and flakes. our multidisciplinary investigation includes an analysis on the lithic surface collection, an assessment of the quality and diversity of lithic raw materials exploited at the site, and an analysis of soil preserved in localised patches. these new findings contribute to our understanding of neanderthal behavioural variability in the southern balkans. we contextualise them at a macro-regional level, drawing comparisons with numerous sites in the adriatic basin, primarily dated between mis 5 and mis 3. keywords: lithic industry, palaeopedology, soil-micromorphology, open-air site, mousterian, korça basin, south-western balkans. 6 ruka r. et al. fig. 1 location and geomorphological map of the basin of korça with position of istraishta site. 1, height spot in metres; 2; town or village; 3, natural and channelised flowing talweg; 4, deep talweg; 5, epigenic gorge; 6, former abandoned course; 7, associated coarse spreading; 8, maliq lake in 1948; 9, marshes related to the lake in 1948; 10, recent alluvial fillings; 11, quaternary alluvial terrace; 12, holocene spreading cone and glacis; 13, undifferentiated quaternary colluvial deposits; 14, active quaternary fault line; 15, fault line without proven recent activity; 16, supposed fault line; 17, flexure; 18, local cleavage; 19, faceted escarpment (normalized slope); 20, faceted fault scarp; 21, steep fault scarp; 22, monoclinal steep slope; 23, pebble conglomerates; 24, ophiolites; 25, karstified limestone range; 26, pliocene hills; 27, neogene molasses (by fouache et al., 2010, modified by davide margaritora). is covered by several non-active, coalescent holocene alluvial cones and glacis. the hill of istraishta stands in isolation (fig. 2a) bounded to the north and south by two deep river erosions: of the kamenica stream valley to the north and a tributary of the dunaveci river to the south. the relief is formed by the anticline of the nappe emplacement of upper triassic-lower jurassic limestones and the molasse of the albanian thessalian basin (middle oligocene). the sequences are displaced by numerous normal faults orientated in a n-s to nne-ssw direction. at the summit, a small morpho-structural relief is formed by an outcrop of oligocene bioclastic calcarenites, approximately two meters thick, containing macro foraminifera, molluscs, and fragments of benthic colonial organisms. this unit overlies a sequence of alternating gravelsandy-siltstone deposits with siliceous conglomerate lenses particularly in the lower section and marls with neritic fossils. the eastern slope of the hill is affected by gullies that erode the marly-arenaceous molasse sequence. in recent times, the hill has been altered by military installations, including repeaters stations, and the limestone bank has been exploited as a domestic quarry. 2.2. discovery and research history of the site the istraishta site was discovered in 2001 during excavations at the nearby kamenica tumulus by albanian prehistorians ilir gjipali and skënder aliu, who visited the location during their fieldwork. gjipali affirmed the site’s early prehistoric nature, although lithic artefacts had first been noted in 1968 by aliu, who neither published nor pursued further research at the site. from 2001 onwards, surface collections were conducted during multiple visits, and the site was briefly mentioned in publications by gjipali, variously described as an early prehistoric, middle palaeolithic, and middle and upper palaeolithic site (gjipali, 2006; 2011; 2012; 2014; aliu, 2020). in 2011, istraishta was revisited as a part of a collaboration between ruka and gjipali for the former’s phd research, which culminated in an overview publication on the early prehistory of the korça basin, including istraishta (ruka, 2018). from 2012 onwards, the site was revisited on several occasions (peresani et al., 2016) and examined in the framework of a long-term albanian-italian research collaboration. initially the site was published under the name of the nearby village, kamenica (peresani et al., 2016). however, to avoid confusion with the excavated tumulus, it was later renamed after the hill on which it is located. 3. materials and methods the primary objective of the archaeological surveys was to analyse the spatial distribution of the artefacts, their relationship with the karst surface, and potential associations with surface deposits and soils preserved within karst fissures. surface collection, gps recording, and examinations of natural and artificial exposures on soil surfaces, gullies, and fluvial erosional banks were conducted (fig. 2b). we considered potential sources of information related to the quaternary context, including geomorphology, soil and sediment composition, and field and micromorphological features of palaeosoils. these analyses aimed to reconstruct the major geomorphic and pedological events responsible for shaping the present-day landscape. additionally, we and tool manufacture, and diverse modes and rhythms of site occupation and resource exploitation. yet, this broader picture remains incomplete. given the current state of knowledge, this study aims to contribute to the reconstruction of middle palaeolithic mountain habitation through the presentation of the data from a multidisciplinary investigation including palaeopedology, petroarchaeometry, and technological analysis of an open-air site located in the korça basin, near the town of korça, in southeastern albania. this region, previously unexplored for palaeolithic research, provides new evidence for future cultural-behavioural comparisons of neanderthals employing different production systems in the southwestern balkans. 2. presentation of the istraishta site in the korça basin 2.1. the quaternary and geomorphological context of istraishta the hill of istraishta (1010 m. a.s.l.) is located at the eastern edge of an intermontane plain in the southwestern korça basin (fig. 1). the plain slopes gently northward, with elevations ranging from approximately 890 m a.s.l. in the south to about 820 m a.s.l. in the north. it is bordered on all sides by mountains rising between 1500 and 2000 m a.s.l. the mountains bordering the korça plain particularly in the south are deeply incised by numerous small but high-energy streams and torrents that contribute sediments to the korça depression. the dunaveci river drains the southern portion of the plain and merges with the devolli river in the north. tectonically, the korça basin is a graben that began forming in the late miocene (xhomo et al., 2002; lindhorst et al., 2015). the basin has an asymmetric shape, with a significantly higher escarpment to the east, where limestone bedrock emerges abruptly. in contrast, molasse formations extensively surround the basin to the west (fouache et al., 2010). tectonic faulting is particularly developed along the eastern boundary, where the plain meets mount morava (mali morava), composed of ultrabasic rocks, and along the northern periphery of mali i thatë mountain, which consists mainly of triassic limestone. during the pliocene, an additional extensional phase of the regional graben system linked the ohrid and korça grabens, forming a unified lake-river system. pliocene to present day tectonic activity, particularly subsidence, gradually isolated the korça graben within its current geological borders, allowing the deposition of interposed pliocene formations in the northern part of the basin (tagari et al., 1993; lindhorst et al., 2015). subsidence led to the formation of graben-shaped quaternary lakes and plains. during this period, the graben lakes of korça, elbasani, zadrima, tirana, myzeqe, and others were formed. holocene fluvial deposits overlie much of the central part of the korça lowland, consisting mostly of alternating and discontinuous layers of variably sorted gravel, sand, ground silt, and clayey silt. the maximum thickness of quaternary deposits in the south-central part of the plain (in the turanbulgarec area) reaches approximately 300 m. mixed alluvial and alluvial fan deposits are widely exposed along the periphery of the korça plain (eftimi & sara, 2022). these deposits mainly consist of interbedded gravel, clay, and silt in highly variable sequences, while the southern part of the basin is characterised by quaternary alluvial terraces. the eastern slope of the basin 7 istraisha, a middle palaeolithic site in southern albania assessed the macroscopic nature of lithic resources in the surrounding area to compare them with the artefacts, aiming to confirm their local provenance. finally, the cultural technocomplex was defined based on the identification of the most typologically diagnostic artefacts, which were also analysed from a technological perspective. 3.1. soil field description and micromorphology two soil profiles, ist_1 and ist_2, respectively located at the southern edge of the top of istraishta hill in a karst fissure and in the central area of the plateau, were selected among other exposures identified during our surveys. these soils, which do not contain any lithic artefacts, are representative of soil patches scattered across the top of istraishta hill in the same area where artefacts were collected. soil horizons were described following fao guidelines (2006), while soil classification and horizon definitions were based on the criteria of soil taxonomy (soil survey staff, 2014) and the ‘world reference base for soil resources’ (iuss working group wrb, 2015). soil colours were determined in a wet state and coded using the munsell® soil colour charts (munsell color, 2009). profile ist_1 was selected for micromorphological analysis in favour of its completeness by respect to profile ist_2. four thin sections were analysed from sediment blocks extracted during surveys from horizons ab, bw, 2bt1b, and 2bt1b of profile ist_1 within a karst fissure (fig. 2b). thin section preparation was carried out by laboratorio servizi per la geologia (piombino, livorno) following the method proposed by murphy (1986). the analysis was conducted using a prior scientific mp3500a microscope with polarised light at 20x, 40x, 100x, and 400x magnifications. descriptions follow the criteria established by bullock et al. (1985), courty et al. (1989) and stoops (2021), while interpretations are based on stoops et al. (2018) and nicosia & stoops (2017). 3.2. lithic industry the lithic assemblage of istraishta consists of 1467 artefacts (see thereafter table 4). of these, less than 20 artefacts are unidentifiable due to intense fragmentation and physical and chromatic alterations caused by thermal stress, weathering, pedological processes, and other factors. these were, therefore, excluded from further discussion. additionally, a subset of fewer than 40 artefacts, securely attributable to the holocene potentially belonging to mesolithic, neolithic, or later periods based 8 fig. 2 views of istraishta hill and soil profile: 1, dtm of istraishta hill and surroundings with position of ist-1 and ist-2 soil profiles (from https://geoportal.asig.gov.al/); 2, the surveyed area looking north; 3, view of istraishta hill from south-east; 4, the ist-1 soil profile. ruka r. et al. the technological analysis is further supported by wellestablished protocols derived from refinements of e. boëda’s foundational definitions (mourre, 2003). in addition to counting all artefacts larger than 1 cm, we conducted a technological analysis on all the identifiable artefacts, using technological and morphological criteria to determine each flake’s role and position within the reduction sequence. the overall reduction sequence was broadly reconstructed based on qualitative reasoning, employing morpho-technical, diacritic, and morphometric analyses of cores, complete blanks, and selected by-products considered significant in the production process. certain reduction strategies, such as the exploitation of the ventral face cores on large cortical flakes, are classified as 'kombewa-type', referring to the adaptation of kombewa technology within the levallois volumetric concept (dauvois, 1981), which is also applicable to the discoid concept (bourguignon & turq, 2003). key typological features of retouched blanks are discussed in the following section. due to the chemicalphysical (patina) and mechanical surface alterations of the artefacts resulting from long-term exposure, we did not consider functional analyses to be viable. on technological and typological grounds was also excluded from the analysis, as it falls outside the scope of this study. the remaining assemblage, which exhibits diagnostic techno-typological features consistent with the middle palaeolithic, is examined in the following section. to broadly identify lithic sources, we conducted petrographic determinations on a representative sample of artefacts at the petropaleo laboratory at the department of humanities, following a standardised protocol based on macroscopic and mesoscopic scales of observation. adhering to established nomenclature (church, 1994; klein, 1999). the pebbles were examined with the naked eye and under a multivariable optical stereomicroscope optika sz series, 45x with camera moticam 3+ usb 3, and progressive magnifications ranging from 5x to 20x (yonekura et al., 2008). the colour was determined according to the munsell® soil colour charts (munsell color, 2009). the conceptual and analytical approach to the technological analysis of the istraishta lithic assemblage follows inizan et al. (1995), boëda (1993), peresani (1998), bourguignon & turq (2003), and references in peresani (2003) regarding the discoid reduction method. 9 tab. 1 field description notes for three profiles at the edge of the istraishta hill. istraisha, a middle palaeolithic site in southern albania 10 4. results 4.1. palaeopedology of profile 1 (ist_1) profile 1 (ist_1) consists of two distinct pedological units forming a complex palaeosoil. the lower unit is a terra rossa-like soil, 35 cm thick, truncated by an erosional surface. it comprises two horizons (2bt1b and 2bt2b) characterised by decarbonation, clay illuviation, and rubefaction. the upper unit represents the present-day soil (a-abbw), measuring 75 cm in thickness and characterised by structural modifications caused by intensive grazing. for detailed field descriptions, see table 1. the thin section analysis of the transitional ab horizon (thin section mm2; table 2) reveals a complex microstructure, it exhibits a highly separated primary granular microstructure, a weakly separated secondary subangular blocky microstructure; and an intrapedal channel microstructure. in mm2, porosity increases compared to the lower portion of the soil (about 10%) with the presence of channels likely formed by tree roots (diameter >2.5 mm) or biogalleries (diameter <5 mm). these biogalleries contain discontinuous and loose microgranular infillings (pedotubules, brewer 1964) attributed to soil mesofauna activities. the relative frequency distribution between the coarse (>20 μm) and the thin fraction follows an open porphyric pattern. the coarse fraction (15%) ranges in size from medium silt and fine sand with polycrystalline quartz characteristic of the granoblastic texture of metamorphic rocks being the dominant component. additionally, rare subangular particles of yellowish volcanic glass and microcrystalline chert are observed. the thin fraction consists of a reddish-brown ground mass composed of clay and slit-sized mineral grains, producing a crystallitic b-fabric. amongst the identified pedofeatures, both discontinuous and continuous loose microgranular infillings are present. these are often associated with coalesced or isolated ellipsoidal excrements produced by mesofauna. the voids contain dense, incomplete infillings of impure clay. furthermore, both typical anorthic impregnations of iron (hydr)oxide nodules, as well as nucleic nodules with angular quartz grains inherited from ancient soils, are observed. notably, fresh roots are found within the channels, along with ca-oxalate (whewellite) crystals. the bw horizon (thin section mm1; table 2) closely resembles the ab horizon in its microstructural characteristics and mineral composition of the ground mass. however, in bw, the coarse fraction is notably reduced. among the identified heavy minerals, rare amphiboles were observed. compared to thin section mm2, the organic content within the thin fraction decreases, while the pedofeatures remain similar. the presence of monomorphic, planar-shaped amorphous organic material with clear, sharp edges silt-sized in dimension suggests traces of micro-charcoal, albeit in very low quantities (<1%). fresh roots were also identified within channels containing ca-oxalate (whewellite) crystals (fig. 3). the horizon 2bt1b (thin section mm3; table 2) differs from the previously described horizons. its ground mass is characterised by subangular and polyhedric peds separated by planar voids. the coarse fraction consists of quartz grains (~10%), mica, rare chert fragments, and volcanic glass. the ground mass is composed of an opaque, brown-reddish, b-fabric speckled clay. pedofeatures indicate active mesofauna bioturbation, evidenced by passage features, loose discontinuous and continuous microgranular infillings, and coalescent ellipsoids excrements. as in the overlying horizons, dense incomplete infillings of impure clay and both typic and nucleic anorthic impregnative iron (hydr)oxide nodules sized similarly to fine sand are common (fig. 3). additionally, this horizon shows an increased presence (5%) of amorphous organic material ranging in size from silt to medium sand, with micro-charcoal still present but in low quantities (<1%). the 2bt2b horizon (thin section mm4) shares the fig. 3 mm1 and mm4 thin sections of the ist_1 soil profile: mm1, a, loose microgranular infilling; mm1, b, charcoal particle; mm4, c, infilling of impure clay; mm4, d, brown-reddish clay groundmass with anorthic impregnative iron (hydr) oxide nodules. ruka r. et al. ture, palaeontological content, silicification degree, and overall integrity. different types of cherts embedded within the adria triassic-jurassic limestones, radiolarites occur in the ophiolite sedimentary covers, and neogene cherts are found within flysch and molasse deposits. additional knappable raw materials include quartzite from the metamorphic basement, ignimbrite from volcano-sedimentary formations, and silcrete from silicified encrusted soils. the post-collisional evolution of the region mainly relates to the formation and evolution of the albanian-thessalian foredeep basin, which has been progressively filled with flysch (since upper cretaceous) and molasse (since eocene). these deposits consist of siliciclastic sediments and shallow marine bioclastic calcarenites, which are locally silicified. the korça basin, as part of this foredeep, overlies the mirdita (ophiolites), korabi (palaeozoic), and krasta-cukali (mesozoic platform-basin limestones). our survey along the eastern slopes of istraishta focused on conglomerate horizons, which are especially common within the eocene-miocene molasse. in conmicropedological features of mm3, with the primary distinction being the pronounced rubefaction of the clayish ground mass. 4.2. lithic raw material sources in the korça basin in the central-eastern hellenides/albanides, knappable lithic resources exhibit significant heterogeneity, reflecting the complex diversification of the region’s geological macro-units. the western adria plate (pelagonian zone) contains mesozoic limestones, neotethys jurassic ophiolites, metamorphic basement slabs, and volcanosedimentary sequences. this intricate regional geological framework results from the closure of the western sector of the neotethys ocean (vardar), whose remnants persist as ophiolite nappes over the eastern margin of the adria continental plate, as well as palaeozoic basement plates (schmidt et al., 2008; bortolotti et al., 2013; sherreiks & boudagher-fadel, 2021) (fig. 4). the sedimentary rocks of the basin and its slope contain chert nodules and layers with distinct characteristics, including variations in size, colour, texture, struc 11 tab. 2 micromorphological features observed throughout the ist_1 soil profile. istraisha, a middle palaeolithic site in southern albania deposits formed below the ccd (calcite compensation depth), possibly in the upper part of the ophiolite covers (vardar) or along the adria continental margins. collected as detritus near outcrops. 2. si. silcrete groups si1. vivid red chalcedony with massive and waxy translucency, with vacuolar porosities filled by microcrystalline quartz and locally with white quartz flames; genesis linked to laterite processes on ophiolite rocks during the cretaceous; non-tectonised. collected as pebbles. si2. yellow fine-textured silicified laterite with a brecciated texture. vacuolar porosities mineralised by zoned white chalcedony. formed through laterite processes on ophiolite rocks during the cretaceous; nontectonised. collected as pebbles. si3. laterite with a fine-textured silicified matrix, featuring chromite mineralisation and quartz veins. its genesis is linked to laterite processes affecting ophiolite rocks during the cretaceous; non-tectonised. collected as pebbles. si4. very fine crystalline grey chalcedony with a white patina and waxy translucency. contains lithoclasts and large green and dark minerals with altered reddish borders. exhibits a brecciated texture with chalcedony and microquartz mineralisation in porosities. formed through laterite processes on ophiolite rocks during the cretaceous; non-tectonised. collected from palaeosoils or alteration horizons (laterite). trast, the older flysch deposits are primarily composed of siltstones and sandstones. the pebbles within these deposits predominately derived from ophiolitic rocks, with additional lithologies sourced from eroded weathered formations. among these, silcrete (skarpelis, 2020) was also identified. during the late miocene, the region’s tectonic regime shifted from compressional to extensional (lindhorst et al., 2015), leading to the formation of several n-s orientated grabens (rifting) that were progressively filled with siliciclastic and lacustrine deposits. extensional tectonics in the region remain active today. as a result, cherts and other knappable raw materials have been redistributed through the quaternary and presentday terrace formations, as well as through torrential gravels in the istraishta surroundings. despite this rich lithic resource landscape, systematic petroarchaeological studies of lithic collections or field surveys of outcropping knappable rocks have yet to be conducted in this particular region. one of the most inclusive descriptions of the regional geological framework remains the national geological map of albania and associated illustrative notes (xhomo et al., 2002). our preliminary analysis suggests that most of the raw materials exploited at the site were collected as pebbles from the molasse conglomerates outcropping in the hills surrounding the southeastern and northwestern margins of the korça plain (fouache et al., 2010). the site itself is situated atop a molasse hill (fig. 1). the pebbles could have been gathered both near the outcrops and from alluvial deposits. in the majority of cases, the raw materials consist of rounded pebbles exhibiting varying degrees of alteration, as indicated by yellow to dark patinas resulting from pedogenetic and lateritic processes. a smaller proportion of raw materials specifically certain blocks of radiolarites and cherts display fresh and unaltered surfaces, suggesting they were probably sourced directly from nearby outcrops. ophiolite units and their sedimentary covers (radiolarites), from the southwestern margin of the korça plain, in close proximity to the site. the identified raw material lithotypes fall into the following categories (table 3, fig. 5): 1. ra. radiolarite groups ra1. grey-green radiolarites with reddish-brown alteration surfaces, exhibiting low silicification. contain poorly preserved white radiolarians and scattered sulphide deposits, some of which are locally oxidised. evidence of hydrothermal metamorphism suggests an origin from the ophiolite covers (vardar). collected as pebbles. ra2. red microlaminated radiolarites with abundant radiolarians, infilled with chalcedony (dark appearance) and pelagic mud (brown to pink). show signs of hydrothermal metamorphism, indicating an origin from the ophiolite covers (vardar). collected as pebbles. ra3. bi coloured green and red radiolarites with wellpreserved, heterometric radiolarians infilled with chalcedony, micro quartz, or calcite. these non tectonised radiolarites are likely derived from partially calcareous 12 fig. 4 schematic geological and tectonic map indicating the main units and basins of central-western balkans. key: 1, adria derived thrust sheets; 2, adria plate; 3, europe derived units; 4, external foredeep; 5, miocene thrust belt; 6, ophiolites and sediments; 7, rhodope complex; 8, tisza mega-unit (after lindhorst et al., 2015, modified by davide margaritora); the red frame corresponds to fig. 1. ruka r. et al. -basins system. collected as pebbles. ch4. dark, low silicified, and massive bituminous chert, with dispersed calcite/dolomite rhombic crystals and thick lamination; depositional environment: intraplatform basins. attribution: triassic-lower jurassic. collected as rounded and altered pebbles. ch5. silicified light yellow to beige, fine-textured biocalcarenite, matte, with abundant white bioclastic detritus (benthic foraminifers and crinoids, spicules, bioclasts). slightly tectonised. depositional environment: continental margin (slope). attribution: adria (pelagonian) mesozoic platform-basins system. ch6. very fine-textured light grey chert with an ivory-like mudstone cortex; contains numerous small white radiolarians and a few small spicules. this pelagic facies is very similar to maiolica limestone. depositional environment: basinal. attribution: adria (pelagonian) mesozoic platform-basins system. collected from paleosoils. 4.3. discoid manufacture the lithic assemblage reflects the typical variability observed in discoid core volumetric patterns, which in turn suggest a range of technical options employed throughout the production sequence. this resulted in two operational chains that were applied across all lithic materials (table 4). this approach aligns with findings from previous studies of similar assemblages across 3. qu. quartzite group qu1. fine-crystalline streaked quartzite with numerous pressure-orientated diaclases, some of which are locally filled by reddish clay. its genesis is attributed to metamorphic processes in the crystalline basement (paleozoic). collected as pebbles. 4. vo. volcanite group vo1. light grey trachyte with alkaline-feldspar phenocrystals. 5. ch. chert groups ch1. silicified light grey bio-calcarenite with sponge spicules, peloids, colonial-organism bioclasts, and benthic foraminifera, and a fine laminated structure. depositional environment: cretaceous-oligocene korça foredeep. collected as evolute pebbles with dark alteration surfaces. ch2. silicified reddish grey bio-calcarenite to mudstone with small spicules, peloids, and bioclasts dispersed in a fine brown-pink matrix. microfossils are often graded and re-sedimented; slightly tectonised. depositional environment: cretaceous-oligocene korça foredeep. collected as evolute pebbles, with dark alteration surfaces. ch3. silicified colonial organism (probably a sponge with clearly visible porosities and cellular structures). classified as framestone (dunham, 1962); slightly tectonised; depositional environment: external platform/ reef. attribution: adria (pelagonian) mesozoic platform 13 istraisha, a middle palaeolithic site in southern albania tab. 3 summary tab. of the main petrographic features of the raw materials exploited in the site. rr= big radiolarians; rr= small radiolarians; sp= small spicules; sp= big spicules; fbent= benthic forams; bcr= benthic crinoids; mol= molluscs; w= white; d= dark; pel= peloids; biocl= bioclasts. tation also induced some distinct modifications to the morphological outline of the cores, reflecting the varied technical strategies employed during manufacture. consequently, the convex flaking surface adopted a centripetal pattern primarily during the main production phase. however, technological analyses reveal both quantitative and qualitative variability in the flaking procedure. various usable blanks were obtained at the onset of exploitation, including slightly elongated and partially cortical flakes. these flakes sometimes retain cortex along a lateral edge, opposite a cutting edge, and often exhibit one or two unidirectional detachments. when the exploitation extended along the lateral edge, preceding the typical alternation between the two main surfaces, europe (see peresani, 2003; delpiano et al., 2018; delpiano & peresani, 2017; arrighi et al., 2009). the first reduction sequence involved the exploitation of medium-sized blocks and pebbles (from 5 to 12 cm on average), with primary products obtained already at the earliest stages, during both decortication and the creation of the core edge, which delimited the two core faces (fig. 6). some cores, measuring between 3.5 to 6 cm, were discarded at this initial stage after producing only a few flakes; these have been classified as ‘partially exploited’ discoid cores. the full production sequence, culminating in discard, was organised around this pivotal crest. in accordance with the substantial accordance with the discoid criteria of predetermination, this exploi 14 fig. 5 knappable raw materials exploited at istraishta, classified into the main lithological groups: radiolarite (ra1-ra3), silcrete (si1-si4), quartzite (qu1), volcanite (vo1), chert (ch1-ch6) (see table 3 for details). ruka r. et al. was punctuated by several readjustments and core preparations. the frequency of by-products displaying flaking errors is notably high, exceeding one hundred specimens. some core readjustments involved the partial removal of the core-edge and the reorientation of the exploitation onto a newly created surface. this technical behaviour, well documented in discoid core reduction, is evidenced here by 14 transversal or longitudinal crested flakes (2-3.5 cm) and a couple of discoid cores (2.5-3.5 cm) structured around three main surfaces (fig. 8). the second operational chain involves the exploitation of flakes as cores (ranging 3-5.5 cm), following a kombewa-type reduction. this approach partially aligns with the discoid volumetric concept and reduction pattern (fig. 9). in this context, the core edge corresponds to the intersection plane between the two faces of the flake. large cortical flakes are the preferred blanks for reduction, sometimes using the bulb as the primary volume of convexity. the exploitation process is relatively simple and less productive, mostly unifacial and concentrated on the ventral surface. however, small detachments on the upper surface are frequently observed, often associated with a partially worked crest. beyond the exploitation of various types of chert, the assemblage encapsulates the full spectrum of discoid techno-economic strategies recognised elsewhere. the high frequency of intact cortical products suggests that core initiation occurred on-site and that the bifurcaflakes with a natural back were produced. these flakes, which are well represented in the istraishta assemblage (n=79), measure between 3.5 and 6.5 cm in length. as decortication progressed, flake size decreased, with simple removal patterns with one or two parallel or convergent removals was progressively replaced by centripetal patterns, in accordance with a reduction process gradually replaced by centripetal patterns, reflecting a reduction process applied consistently throughout the sequence. the main production phase yielded a variety of blank types, determined by the organisation of core reduction. detachments serve both predetermined and predeterminant functions, ensuring adherence to the technical criteria of the core organisation, including the maintenance of surface convexities and angles. the two flaking axes centripetal and chordal relative to the core outline allow different approaches to shaping surface convexity. from the beginning of this stage, 25 débordant flakes and 24 centripetal flakes with cortical surfaces attest to the attainment of full production before the complete shaping and decortication of the core, which was discarded once it has been reduced to 2.5 to 4.5 cm in length. the primary production process focuses on generating a characteristic range of discoid blanks, including centripetal flakes (3-6 cm), core-edge removal flakes (éclats débordants) (2-4.5 cm), and pseudo-levallois points (1.5-4.5 cm) (fig. 7). this sequence 15 tab. 4 composition of the istraishta lithic assemblage. istraisha, a middle palaeolithic site in southern albania retouching is confirmed by the presence of two retouch flakes, attesting to the shaping of thick scrapers. scrapers constitute the predominant tool type (n=15) (fig. 10). although most of the tools are fragmented, some simple scrapers made from chert can be identified, primarily characterised by a straight longitudinal profile. notably, two proximal fragments of double scrapers in red and green radiolarite are present. the first exhibits a double, simple, and straight retouch, while the second features a left direct scalar retouch and a right inverse flat retouch. additionally, a fragmented convergent scraper is also made on radiolarite. the largest retouched tool in the assemblage is a simple denticulated scraper, manufactured on a 7.5 cm flake with a natural back. the assemblage is further composed of two notches, one denticulated tool, and three flakes with marginal retouch. some other tools may belong to a more recent (post-pleistocene) phase of human frequentation at the site. tion of discoid production into two operational sequences followed broadly comparable proportions. this is evidenced by the number of cores-on-flake (n=46) and the kombewa-type flakes (n=42). some discoid cores on thin slabs (n=11) or flakes (n=36), ranging from 4 to 6 cm in size, exhibit a very low degree of exploitation. these cores are characterised by a limited number of bifacial detachments, which shape a sinuous lateral edge, suggesting a deliberate search for exceptionally small discoid blanks. this interpretation is further supported by the diminutive size of the resulting pseudolevallois points and core-edge removal flakes, some of which measure less than 2 cm. 4.4. tool shaping the number of retouched tools is relatively low (n=21). it is reasonable to suggest that some middle palaeolithic retouched tools may have been introduced into the site already shaped, given the significant diversity of raw materials. however, evidence of on-site tool 16 fig. 6 discoid lithic assemblage: 1, unipolar-bidirectional flake; 2-5, cortically backed flakes. fig. 7 discoid lithic assemblage: 1-2, centripetal flakes; 3, 5, core-edge removal flakes; 4, 6-11, pseudo-levallois points. ruka r. et al. differences are observed in blank selection and raw material properties, lithic production and economy remain consistent across the different lithological groups. levallois technology is represented by a small number of artefacts, including seven cores and 14 flakes with prepared butts. additionally, some cores and flakes exhibit knapping on a single surface and follow a similar volumetric concept with two hierarchised surfaces, albeit without the meticulous preparation of the striking plat4.5. levallois flakes and cores the assemblage also includes levallois blanks (2.5 -5 cm) and cores (4-6 cm), along with flakes detached for the reconfiguration and maintenance of cores during reduction (fig. 11). the raw materials used for levallois implements are similar to those employed for discoid lithic artefacts, with fine-grained greyish chert being the most commonly exploited, while other raw material types are much less frequently represented. although slight 17 istraisha, a middle palaeolithic site in southern albania fig. 8 discoid cores: 1-2, typical discoid cores; 3, bifacial core with small detachment; 4-6, partially developed discoid cores; 7, discoid core on three surfaces. fig. 9 discoid cores: 1,3,5, discoid cores on flake; 2, core on flake with small bifacial detachments; 4, kombewa-type flake. the presence of a coarse quartz fraction, combined with a fine clayish texture that imparts a porphyric-peripheric distribution to the groundmass, serves as clear evidence of an advanced stage of soil weathering. the coarse fraction, composed of less weatherable and resistant minerals such as quartz, is typical of highly weathered horizons, akin to those found in oxisols (iuss working group wrb, 2015) or laterites. among the coarse components, subangular particles of yellowish volcanic glass identified as palagonite were detected, albeit in low concentrations. additionally, the presence of fine clayish, reddish material with a heterogeneous b-fabric is indicative of sub-superficial oxic horizons undergoing a high degree of pedogenetic evolution. such horizons typically develop on ancient and stable surfaces where a rejuvenation does not occur, marking a case of longterm pedogenesis. the polyhedric and angular microstructure, associated with a dense groundmass with an open porphyric c/f distribution, is characteristic of soil affected by cryform. 5. discussion 5.1. the polycyclic soil of istraishta and its quaternary frame profile 1 sequence of ist_1 resembles the features typical of polycyclic soils (duchaufour, 1983). the lower unit comprises horizons 2bt1b and 2bt2b (thin sections mm3 and mm4 respectively), while the upper unit is formed by horizons ab and bw (thin sections mm1 and mm2, respectively). both units are entirely decarbonised. the lower unit presents distinctive ‘terra rossa’ features and can be classified as fersiallitic soil (duchaufour, 1983) or luvisol (iuss working group wrb, 2015). such soils typically form a discontinuous layer of variable thickness ranging from a few centimetres to several metres overlying hard limestone and dolomitic rocks in karstic regions (durn et al., 1999; durn, 2003; merino et al., 2006; torrent, 2005). the soil colour, ranging from 5yr to 2.5yr (munsell colour, 2009), is a diagnostic feature of ‘mediterranean terre rosse’ and reflects the intensity of the rubefaction processes, particularly the preferential formation of haematite over goethite (schwertmann & taylor, 1989). the parent material has a polygenetic origin, resulting from the karstic dissolution of the limestone substrate, followed by the pedogenetic evolution of residual clay and the incorporation of allochthonous aeolian components (quartz, mica, volcanic glass, amphiboles). concerning micromorphology, the deep horizon 2bt2b is characterised by a strong accumulation of sesquioxides. in addition to rubefaction and a clay-rich ground mass, there is a notable absence of textural pedological features on void surfaces. this is consistent with the development of fersiallitic soil and suggests that intense bioturbation by mesofauna has led to the complete incorporation of these features into the ground mass. the upper unit shows similar micropedological features to the lower unit but also displays distinct characteristics in horizons bw1 and ab (thin sections mm1 and mm2, respectively). the transitional ab horizon can be identified by an increased organic fraction within the groundmass and a significant rise in biological activity. 18 ruka r. et al. fig. 10 istraishta retouched tools: 1, simple denticulated scraper; 2, double scraper with alternate retouch; 3, double scraper; 4, notch; 5, fragmented scraper; 6-8, convergent scrapers. fig. 11 levallois cores and products: 1-2, hierarchised cores on surface; 3, levallois flake; 4-5, levallois cores. weathering of the silt particles observed in ist_1 makes it difficult to identify their precise sources. loess deposition has affected istria and the dalmatian archipelago since the early middle pleistocene (cremaschi, 1990). the formation of these strongly weathered paleosoils is related to a prolonged period of biostasy, uninterrupted by major climatic shifts throughout the chibanian and late pleistocene. consequently, most studies in quaternary palaeopedology interpret terra rossa like a polygenetic relict soil that may have originated as early as the tertiary, the early pleistocene, or during warm interglacial periods following the mid-pleistocene climate transition (see durn, 2003, for review). however, a more plausible interpretation is that these soils represent vetusols (cremaschi, 1987), in which pedogenetic processes have continuously operated over extended timescales since the mid-pleistocene (bronger & sedov, 2002) or even the latter part of the late pleistocene, as observed in the southern mediterranean rim (gvirtzman & wieder, 2001). at istraishta, as in comparable contexts, this prolonged pedogenic phase was subsequently influenced by later land-use conditions, as evidenced by the confirmation of unstable conditions and the transformation of the soil into brown. in summary, the geochronological position of the istraishta middle palaeolithic industry, recovered from above the terra rossa soil at the top of the hill, remains broadly defined between the chibanian and the late pleistocene. however, it may be further constrained between the earliest presumed appearance of discoid technological assemblages in southern europe and the balkans, dating to mis5e, and the latest occurrences of these industries in mis3, as outlined in the following section. 5.2. discoid knapping on the edge beyond the extensive use of the levallois method, neanderthals exhibited significant technical variability, with discoid technology serving as a particularly illustrative comparative case. initially defined in the 90s in terms of its principal volumetric criteria (boëda, 1993) and subsequently explored in greater detail to assess its variability of application (see peresani, ed. 2003), this core shaping, exploitation, and maintenance strategy is traditionally considered less predetermined but more prolific and versatile/flexible than the levallois method. several factors support this interpretation, foremost among them being the inherently recurrent nature of its reductive and productive concept, by concatenating the exploitation of the core-faces and facilitating the detachment of both predetermining and predetermined pieces without embedded phases of shaping. this adaptability allows the production of a wide range of functional products from a qualitatively wider range of raw materials than the levallois and other technologies. as a result, discoid technology is particularly well-suited to overcoming ecological constraints and mitigating potential limitations associated with landscapes devoid of highquality knappable raw materials (turq et al., 2017). due to its applicability to a wide spectrum of different shapes, the discoid reduction concept can also extend to the exploitation of flakes, with maintenance stages and resulting products that are fully comparable to those produced through discoid reduction sequences on nodules or pebbles (bourguignon & turq, 2003). at several european sites, the discoid method was used with varying frequency within the broader producoturbation. in addition, the presence of an overlapping microstructure with channels containing loose discontinuous microgranular infillings often associated with coalescent ellipsoidal faecal pellets provides clear evidence of mesofaunal biological activity and root penetration in the sub-superficial horizon. these pedofeatures caused by mesofauna activity, combined with fresh root traces in channels characterised by whewellite crystals, indicate a recent shift in land use, notably from woodland to pasture. this transition is reflected in the gradual superimposition of a granular intrapedal and channel microstructure over the original angular polyhedral micro aggregation possibly also prismatic, although its exact morphology is difficult to determine at the thin section scale. dense and incomplete impure clay infillings maybe interpreted as illuviation phenomena and/or microstructural degradation resulting from vegetational cover loss. this phenomenon has also led to a significant increase in porosity in the sub-superficial portion of the rare (<1%) microcarbon particles, appearing as amorphous and monomorphic organic material with flat shapes and well-defined surfaces, having been observed. in the absence of direct dating, determining the geochronological position of the istraishta palaeolithic assemblage remains challenging. the only viable approach relies on the assumption that the red clayey soil analysed at the ist_1 profile is representative of the overall broader palaeopedogenetic context that developed atop the eocene carbonate bedrock at the summit of the hill. the ist_1 palaeosoil has been classified within the subclass of soils commonly referred to as terra rossa, which is largely diffused across carbonatic bedrocks in the mediterranean rim, including an extensive belt in the western balkans (durn, 2003). the processes of total decarbonation, clay illuviation, rubefaction, the enrichment of weathering-resistant mineral species, and the high concentration of fe (hydr)oxides all correspond to the characteristics of modal fersiallitic red soils (duchaufour, 1983), developed under stable interglacial climatic conditions, especially at midlatitudes (durn, 2003). typically, these soils accumulate discontinuously, varying in thickness from a few centimetres to several meters, and are primarily preserved on surfaces, within cracks, sinkholes, or other depressions formed through the dissolution of limestones and dolomites. non-primary red-clayey accumulations, commonly termed terra rossa-like materials, are often found in karst depressions or as contributors to pedosedimentary colluvial sequences; however, this is not the case at istraishta. given that the site is located on hard and permeable limestones and dolomite formations with a notably low insoluble residue content consistent with other regions of the balkans (macleod, 1980) it is likely that terra rossa soils here have incorporated external materials. these could have originated from volcanic events, aeolian streams, shallow water transport, and other processes, thereby diminishing the significance of the primary parent material derived from the insoluble residue of bedrocks (yaalon, 1997). evidence suggests that aeolian and pyroclastic material from the tyrrhenian area was transported across both sides of the central adriatic basin during the pleistocene (chiesa et al., 1990; šušnjara et al., 1994), with no exclusion of wind-borne material from africa (rapp, 1984). the addition of aeolian and volcanic dust to the istraishta soil is likely, although the high dispersion and 19 istraisha, a middle palaeolithic site in southern albania 2015). the industry is typically represented by cores, thick flakes, pseudo-levallois points, backed flakes with sharp opposing edges, polygonal and triangular flakes, produced through a main complex reduction sequence based on blocks and nodules, and a secondary, simpler, and less productive sequence based on flake-cores, either derived from by-products or directly introduced to the site. furthermore, like the istraishta assemblage, cores yielded usable blanks from the initial reduction stages, with core outlines gradually shifting from a unidirectional to a discoid pattern. this process involved continuous modification, ultimately resulting in polyhedral core shapes (delpiano & peresani, 2017; delpiano et al., 2017; 2018). the retouched toolset includes scrapers, points, denticulates, and tools intentionally modified to create a backed edge, either through retouching or by adapting an existing back for manual handling or potential hafting. these modifications suggest different levels of expertise and technical skill, reinforcing the notion that backing although rarely observed was a typical characteristic feature of neanderthal technological repertoires (delpiano et al., 2019). this feature is particularly prevalent in the late mousterian discoid technology (gravina & discamps, 2015; bodu et al., 2014); however, it is not present at istraishta. few archaeological contexts are geographically close to fumane cave (fig. 12). among them is the open-air site of monte cason, which remains undated. here, levallois was applied to allochthonous chert, whereas discoid was used on local raw materials (bertola & peresani, 2000). further west, discoid assemblages are present in the ciota ciara cave (daffara et al., 2014). a well-established mis3 chronology is known for rio secco cave, where this technology is evidenced by core-edge removal flakes and pseudolevallois points, in a region notably poor in chert (peresani et al., 2014). beyond rio secco, the only documented evidence of discoid industry and tools comes from divje babe i in the slovenian alps and caverna degli orsi in the trieste karst. late mis5 and mis4 sediments yielded only end-products, including a few pseudo-levallois points made from local and allochthonous chert and limestone (boschian, 1999-2000; boschian & de santis, 2011). at divje babe i, findings from layer 7 have been bracketed between the 14c dates of layer 6 (minimum age of 43.4+1/-1.4 cal ka bp) and layer 8 (maximum age of 45.1+1.5/-18 cal ka bp) (nelson, 1997), with later esr dating placing them between 49.0-50.1 cal ka bp (blackwell et al., 2009). more recent publications recognise the presence of the discoid cores alongside levallois cores and products, suggesting a broader use of the discoid method throughout the stratigraphy, with a higher frequency in levels a, a/ b, e 2, f 2, and h (turk & turk, 2014; turk, 2014). south of the trieste karst, in istria, the campanož open -air site features a large and densely packed lithic scatter, stratified between two horizons of mediterranean terra rossa soil. discoid production was organised on unifacial and bifacial cores and focused on small tools, with evidence of recycling of previously discarded artefacts. retouched tools include scrapers and abrupt points (banda et al., 2022). beyond these, no other discoid industries have been described in the upper adriatic region (peresani & tozzi, 2018). similar to the eastern adriatic, mousterian assemblages associated with discoid technology are absent in tive systems, ranging from ephemeral to dominant, and even exclusive in certain contexts and temporal phases. although this reduction technique was not solely a ’supporting‘ procedure aimed at maximising production, it does not appear to reflect in-depth planning. instead, it seems to be part of a place-provisioning strategy focused on short-term exploitation. in these cases, as previously investigated by delagnes & rendu (2011), the groups employing this technology would be characterised by increased seasonal mobility. lithic production, being internally diverse and highly ramified, would thus have had a high potential for immediate adaptability to varying needs. the advantage of the discoid method appears to lie in its ability to maintain a high degree of adaptability and renewal through strategies less constrained by environmental factors. this behaviour of technological flexibility can be interpreted as a rational and planned response, consistent with recent evidence of logistical planning in economic organisation in semilocal or exotic territories. this organisation would have been influenced by the quality and distance of available raw material sources, as well as by the systematic segmentation of the operative chain (delpiano et al., 2018). 5.3. discoid assemblages in the south-eastern european context the presence of industries employing discoid technology is well-documented in late middle pleistocene and late pleistocene sites across europe (see peresani, 2003, and papers therein). notable examples are also found in eastern italy and the balkans, where this technology is recorded at a limited number of sites alongside levallois reduction methods. however, these two technologies appear to have been applied differently depending on the suitability of available raw materials for knapping. levallois is generally associated with higher quality and occasionally allochthonous raw materials, whereas the discoid is predominantly linked to strictly local resources, irrespective of quality. in such cases, discoid technology seems to have been primarily employed to maximise the exploitation of local resources, with final reduction sequences serving only secondary purposes. in eastern italy, the distribution of discoid-based industries spans geographical regions with diverse physical landscapes, lithic resources, and varying degrees of settlement system visibility, including the eastern prealps, the trieste karst, and the stretch on the adriatic coast (peresani, 2003). some of these lithic assemblages were recovered from the surface at open-air sites lacking faunal remains and direct correlated pedostratigraphic correlation. at fumane cave, the cultural significance of unit a9 has been highlighted on several occasions, both for its discoid production technology and for various aspects of neanderthal innovative behaviours, diet, and subsistence (peresani, 2022, see references therein). the dates for a9 are older than 44.8 cal ka bp, which marks the lower chronological boundary of units a5+a6. unit a9 records an almost exclusive use of this technology positioned between two levallois units: a10 at the base and a6 at the top. the techno-economic structure of the a9 assemblage consists of complete reduction sequences carried out on local cherts, with occasional use of materials sourced from greater distances (delpiano et al., 2018). additionally, the assemblage includes patinated recycled artefacts (peresani et al., 20 ruka r. et al. pean contexts. the increased frequency of discoid assemblages toward the end of the middle palaeolithic aligns with the decline of levallois industries and a rise in technological variability an observable trend in italy (marciani et al., 2020) as well as in the iberian peninsula (romagnoli et al., 2022). this chronological and geographic distribution persists regardless of regional relationships, palaeo-environmental context, site typology, or associated faunal spectrum. environmental data do not indicate a strong correlation between site type and industry, particularly in sheltered, multilayered sites. this pattern is evident in the fumane sequence, where forest landscapes and ungulate associations remain stable despite shifts between levallois and discoid assemblages (lópez-garcia et al., 2015). in the balkans, at mujina pećina cave, along the dalmatian coast in croatia, has yielded rare elements of discoid technology, including a core and possible pseudo-levallois point (karavanić et al., 2008) (fig. 12). these finds have been attributed to the late mousterian (boschian et al., 2017; karavanić et al., 2021). another noteworthy case is podvršje-šibenička glava, an openair site in northern dalmatia, where several cores have been identified alongside various flakes, notches, denticulates, and sidescrapers. notably, levallois cores are absent, with only a single levallois flake recorded (vujević, 2009; vujević et al., 2017). further inland, in the mid-adriatic region of the lower western adriatic basin but reappear further south in the italian peninsula (fig. 12). in santa croce di bisceglie cave, although undated, pedo-sedimentary and paleontological data suggests a mis 4 chronology. here, the reduction sequence was aimed at producing sub-triangular flakes and pseudo-levallois points (arrighi et al., 2009). in the salento region, grotta del cavallo records discoid technology as complementary to unipolar débitage in layers m and l, while it becomes exclusive in the upper layers fiiia and fii. these upper layers are stratigraphically separated from the lower, more levallois-dominated assemblages. throughout the sequence, raw materialuse strategies vary, and a notable miniaturisation in production is evident in layer m (sarti et al., 2017). interestingly, a recurrent débitage on secant planes, exploiting only part of the core, is reported. following a similar reduction concept, istraishta contains numerous cores on slabs or flakes, which we classify as ‘low exploited discoid cores’ used to produce very small blanks. finally, near grotta del cavallo, grotta mario bernardini presents an analogous sequence, featuring both unifacial and bifacial variants of discoid debitage, along with the reduction of the ventral surface of cores-on-flakes (carmignani & romagnoli, 2017). the timespan bracketed by these industries is notably broad, highlighting their affinities with other euro 21 fig. 12 map of sites containing discoid industries: 1, fumane cave; 2, tagliente shelter; 3, rio secco cave; 4, caverna degli orsi cave; 5, santa croce cave; 6; mario bernardini cave; 7, cavallo cave; 8, divje babe cave; 9, campanož; 10, podvršje-šibeni glava; 11, kamen; 12, zobište shelter; 13, visoko brdo; 14, londža; 15, mališina stijena; 16, crvena stijena; 17, bioče; 18, golema pesht; 19, uzun mera; 20, mujina pećina; 21, molondra; 22, eleftherochori 7; 23, mikro karvounari; 24, megalo karvounari; 25, morfi; 26, asprochaliko; 27, kokkinopilos ; 28, dalani i vogël. the position of istraishta is shown (map created by davide margaritora). istraisha, a middle palaeolithic site in southern albania confirmed these findings in newly defined layers b2 and c1 (derevianko et al., 2021; shunkov et al., 2021). further inland, in northern macedonia, systematic research on the middle palaeolithic remains limited. the most important mp site is golema pešt cave (fig. 12), where late mp layers (6 and 5), contain both levallois and discoid cores on quartzite, along with numerous byproducts. ci tephra has been identified in layer 2, which is believed to overlie early up layers. preliminary esr dating of layer 3 places it between 83-61.8 ka, serving as a terminus ante quem for the yet unpublished esr estimates for layers 6 and 5 (salamanov-korobar, 2008; 2019; lowe et al., 2012; blackwell et al., 2019). additionally, the recently explored open-air site of uzun mera has provided evidence of mp discoid technology (stojanovski et al., 2018). in albania, small quantities of discoid cores and products have been found alongside larger levallois assemblages in open-air sites across the western regions of mallakastra, shkodra, and dalani i vogël. notably, levallois artefacts from dalani i vogël may date as late as 42.9 cal ka bp and 38.7 cal ka bp (runnels et al., 2009; ruka, 2023; badino et al., 2025). further south, in northwestern greece and adjacent to southern albania, 104 mp sites had been reported by 2015, yielding a variety of assemblages (fig. 12). the dated contexts range from mis 5e or slightly earlier to the first half of mis 3 (elefanti & gilbert, 2015). many openair sites. often associated with terra rossa deposits, are dominated by levallois method and products but occasionally contain discoid cores and products such as the sites of kokkinopilos, megalo karvounari, mikro karvounari, molondra, morphi, eleftherochori 1 and 3, kastoria area, samarina 1 and 2, and lake smixi (dakaris et al., 1964; kourtessi-philippakis, 1986; bailey et al., 1992; papaconstantinou & vassilopoulou, 1997; papagianni, 2000; galanidou, 2007; ligkovanlis, 2011, 2017 and 2018; papoulia, 2011; efstratiou et al., 2014; biagi et al., 2017 and 2023; papadea, 2019; ligkovanlis et al., 2022). however, two mp sites in northwestern greece stand out in relation to this study: asprochaliko and eleftherochori 7, both located in epirus and relatively close to istraishta. asprochaliko is a rock shelter that has been excavated and stratigraphically divided into two main units: the basal mousterian was thought to be dominated by levallois technology, while the upper mousterian was characterised by an exclusive use of the discoid technology. the upper mousterian has been dated using two conflicting 14c dates from layer 14, spit 19: one falls within the upper palaeolithic range (3227.6 cal ka bp), while the second is regarded as terminus ante quem (> 44.3 cal ka bp). this latter date has been generally regarded as upper mousterian. similarly, the basal mousterian has been dated using both 14c and tl methods. a single 14c date in layer 18, spit 30 produced a relatively young result (> 50-37.1 cal ka bp), whereas two tl dates from layer 18, spits 38-40, ranged between 102±14 ka and 96±11 ka (bailey et al., 1992; huxtable et al., 1992; gowlett & carter, 1997; papaconstantinou & vassilopoulou, 1997; papagianni, 2000; facorellis, 2013). more recently, the initial technological interpretations of the basal unit have been challenged and revised. it is now considered to be predominately discoid technology, with a minor presence of cores-on-flakes, whereas the upper unit appears to show the reverse pattern. notably, the basal mousterian assemblage contains 14 cores-on-flakes, which may the hrvatsko zagorje region, several significant cave sites have been identified. at veternica cave, the lithic assemblage is composed of non-levallois reduction methods, including centripetal cores and ‘cobble wedge cores,’ which require further analysis before they can be definitively classified as discoid. however, due to the loss of stratigraphic provenance, the assemblage is broadly attributed to mis 5e-5a or mis 4 (banda & karavanić, 2019). the same ‘cobble wedge’ cores were extensively used at krapina cave, whereas sidescrapers, notches, denticulates, and naturally backed knives dominate the assemblage. while levallois blanks appear throughout the sequence, they are not common, similarly to discoid cores, which remain occasional (simek, 1991; simek & smith, 1997). a comparable technological pattern is also observed at the late mousterian site of vinica cave, where a variety of reduction sequences including unidirectional, discoidal, and bidirectional cores were predominantly applied to quartz pebble. although levallois cores are absent, a few levallois products appear to have been transported to the site as finished products (vukosavljević et al., 2022). regarding bosnia and herzegovia, despite the lack of systematic research, an extensive presence of discoid cores has been noted at several sites, including visoko brdo, kamen, londža, and zobište. among these, zobište is the only site in the region that has been tl dated, with results ranging between 97.5±7 ka and 85.5±8.5 ka (baumler, 1987; 1988). in montenegro, three cave sites with middle palaeolithic components have been identified, each containing different levels of discoid technology (fig. 12). however, an increasing prevalence of levallois centripetal core exploitation over unidirectional reduction is observed in the later middle palaeolithic, particularly in sequences at crvena stijena and bioče (dogandžić & ðuričić, 2017). crvena stijena is well-known for its extensive prehistoric sequence and recent multidisciplinary research. discoid cores with one or two flaking surfaces, along with their associated products, appear throughout the sequence, from the deepest layers xxxi to layer xii. notably, an emphasis on unifacial discoidal cores is recorded in the later levels xii and xiv. the overall sequence likely spans from mis6/5 to the campanian ignimbrite (ci) eruption, which marks the final mp layer xii (mihailović, 2024; morley & woodward, 2011; mihailović & whallon, ed. 2017; monnier et al., 2020). bioče, another important site, was initially excavated between 1986 and 1997. discoid technology, alongside levallois, was recognised early within a stratigraphic sequence estimated to range from mis 5 and mis 4 to the ci eruption. the lithic industry, described as micromousterian, remains relatively uniform throughout the sequence (đuričić, 1997; dogandžić & đuričić, 2017). more recent excavations (2010-2015) uncovered deeper layers with similar characteristics. particularly significant is upper layer 1, which contains 90% of the total artefacts recovered and is dominated by discoid technology. its association with the ci eruption has been considered evidence of late neanderthal survival in the region (pavlenok et al., 2017; vishnevskiy et al., 2019; dragosavac et al., 2021). mališina stijena, the third site, has received comparatively less attention. initial excavations in the 1980’s identified discoid cores and related products in layers 3b13 (southern trench) and layers 13-12 (western trench) (radovanović, 1986). recent excavations have 22 ruka r. et al. 6. conclusions discoid industries were widespread across southern europe and other parts of western eurasia, appearing in diverse geographic and palaeo-environmental contexts, across various site types, and in association with different faunal spectrums and coexistence with other flaking methods. while the middle palaeolithic record of the western balkans shows a significant occurrence of the discoid method, dedicated studies on its prevalence remain scarce, partly due to its limited recognition in the scientific literature. when identified, discoid products appear in varying proportions, from minor occurrences to nearly exclusive dominance, often accompanied by small quantities of levallois products. the latter pattern is evident at istraishta, where discoid technology predominates, similar to sites such as asprochaliko, eleftherohori 7, and further afield, fumane. while a general classification of these assemblages under the discoid core reduction method is justified, each site exhibits unique characteristics. for instance, at fumane, backed pieces were intentionally prepared, whereas in the basal mousterian of asprochaliko, the ventral sides of large flakes were used as striking platforms for discoid cores. at istraishta, eleftherohori 7, and most of the discoid industries, pseudo-levallois points appear in varying frequencies, produced mainly from fully or partially developed discoid cores. a higher percentage of cores, along with a notably lower occurrence of cores on flakes, suggests a connection between istraishta, eleftherohori 7, and the basal mousterian of asprochaliko. however, do these variations reflect merely geographical adaptations, or do they indicate broader chronological patterns and widespread cultural traditions? given the current state of research on the western balkans, it remains difficult to determine the underlying causes of these differences. recent discoveries, including surface finds and open-air sites from field surveys in northwestern greece and southern albania (gjipali, 2006; forsén et al., 2011; adam, 2014; 2019; ruka et al., 2014; galanidou, 2007; et al., 2018; 2021; ligkovanlis & kourtessi-philippakis, 2022), as well as along the eastern adriatic fringe, have identified mp discoid assemblages. some of these findspots are related to terra rossa deposits, as is the case with istraishta. ongoing research in northwestern greece has aimed to clarify the taphonomy and chronostratigraphic relation of the mp assemblages with terra rossa deposits. however, despite continuous efforts, secure results have yet to be achieved (ligkovanlis et al., 2022), and the current resolution remains insufficient for further interpretations. similarly, in serbia’s mp record, the so called non-levallois facies (mihailović & mihailović, 2023) appear to span from mis 5 through mis 3, up to the onset of the upper palaeolithic a pattern also observed in other parts of the balkans (dogandžić, 2023; karavanić & banda, 2023). although chronological resolution remains limited, the variability seen in these assemblages likely stems from the inherent adaptability and versatility of the discoid method. as previously noted, the flexibility inherent in this reduction method would have facilitated the successful adaptations of highly mobile groups to diverse environments. moreover, the evidence from these sites suggests that the variety of exploited raw materials did not dictate the selection of a particular flaking method. inhave repurposed flakes from earlier stages of discoid production as blanks. these cores are ‘usually semicentripetally worked with the ventral faces of the flakes used as striking platforms’ (ligkovanlis, 2016). such a strategy does not appear in the assemblages of istraishta or eleftherohori 7, although end-products such as pseudo-levallois points are particularly abundant at all three sites. in addition, eleftherochori 7 is an open-air site that has been surface-collected and rescueexcavated through 55 trenches. its large lithic assemblage of mp and up components is mixed between two layers. the mp assemblage is dominated by discoid technology, which appears to closely resemble the basal mousterian of asprochaliko (ligkovanlis, 2013; 2017; ligkovanlis et al., 2022). the current evidence from the aforementioned western balkan sites suggests a chronological range from mis 6/5 to mis 3, providing a general timeframe for the istraishta assemblage. a notable characteristic of the istraishta lithic assemblage is its resemblance to the micro-mousterian industries of the balkans and the mediterranean area. these industries are defined by the small average size of the artefacts (mihailović, 2020; dogandžić, 2023) and are interpreted as the result of intense local raw material exploitation linked to neanderthal mobility and site occupation frequency (mihailović & whallon, 2017). this process also affected levallois cores, which progressively diminished in size due to prolonged reduction, leading to fewer residual cores (gowlett & carter, 1997). the overall microlithisation of these industries maintains the same general artefact classes found in other mousterian assemblages in southern europe, including the pontinian in italy (kuhn, 1995; rolfo et al., 2022). however, the reasons behind the small artefact sizes vary across contexts. in some cases, artefacts were made of small, locally available, low-quality raw materials, meaning their size was not necessarily the result of extensive core reduction and did not result from the overexploitation of natural cobbles (karavanić, 2004; dogandžić & ðuričić, 2017; banda et al., 2022). in other cases, the deliberate selection of small nodules, despite the availability of larger river pebbles, suggests that the production of micro-tools was an intentional technological choice (ðuričić, 2006). given that both raw material constraints and core reduction intensity can drive the overall reduction in artefact size, it is difficult to isolate the effects of each. in most cases, the characteristics of lithic industries result from a combination of these effects. micro-mousterian industries are typically characterised by retouched flakes, sidescrapers, denticulates, and notched pieces, with sidescrapers generally being the most dominant tool type. however, some assemblages such as those from crvena stijena and open-air sites along the dalmatian coast exhibit a notable prevalence of denticulates (karavanić & banda, 2023). constraints in raw material provisioning may have led to increased tool reduction, as repeated rejuvenation stages were necessary to extend tool usability. this process was influenced by both the physical properties of the knapped stones and the constraints in raw materials provisioning. however, studies from crvena stijena and bioče reveal that tool reduction was not primarily driven by raw material scarcity but rather by core reduction intensity, which resulted from the frequent and repeated occupation of these sites (dogandžić & ðuričić, 2017; pavlenok et al., 2017). 23 istraisha, a middle palaeolithic site in southern albania špilje veternice/the mousterian industry of veternica cave. prilozi instituta za arheologiju u zagrebu, 36, 5-40. banda m., romagnoli f., komšo d., čuka m., karavanić i. (2022) exploring a novelty in the middle palaeolithic of croatia: preliminary data on the open-air site of campanož. quartär, 69, 29-56. baumler m.f. (1987) core reduction sequences: an analysis of blank production in the middle paleolithic of northern bosnia. ph.d., tucson, the university of arizona. baumler m.f. (1988) core reduction, flake production, and the middle paleolithic industry of zobište (yugoslavia). in dibble h.l., montet-white a. (eds.) upper pleistocene prehistory of western eurasia. university museum symposium series ,1. pennsylvania, pa, university of pennsylvania museum, 255-74. bertola s., peresani m. (2000) variabilità tecnologica in due insiemi litici di superficie dei colli berici. quaderni di archeologia del veneto, xvi, 92-96. biagi p., nisbet r., starnini e., efstratiou n., michniak r. (2017) where mountains and neanderthals meet: the middle palaeolithic settlement of samarina in the northern pindus (western macedonia, greece). eurasian prehistory 13 (1-2), 3-76. biagi p., starnini e., efstratiou n., nisbet r., hughes p. d., woodward j. c. (2023) mountain landscape and human settlement in the pindus range: the samarina highland zones of western macedonia, greece. land, 12 (1), 96. doi: 10.3390/land12010096 blackwell b.a.b., yu e.s.k., skinner a.r., turk i., blickstein j.i.b., skaberne d., turk j., lau b. (2009) dating and paleoenvironmental interpretation of the late pleistocene archaeological deposits at divje babe i, slovenia. in: the mediterranean from 50,000 to 25,000 bp: turning points and new directions. oxbow books, 51-62. blackwell b.a.b., šalamanov-korobar l., huang c.l.c., zhuo j.l., kitanovski b., blickstein j.i.b., florentin j.a., vasilevski s. (2019) sedimentary radioactivity in an upper paleolithic-middle paleolithic (mp-up) transition site: increasing esr tooth dating accuracy at golema pešt, north macedonia. radiation protection dosimetry, 186(1), 94112. bodu p., salomon h., leroyer m., naton h.-g., lacarriere j., dessoles m. (2014) an open-air site from the recent middle palaeolithic in the paris basin (france): les bossats at ormesson (seineet-marne). quaternary international, 331, 39-59. boëda e. (1993) le débitage discoïde et le débitage levallois récurrent centripète. bullettin de la société préhistorique française, 90(6), 392-404. bortolotti v., chiari m., marroni m., pandolfi l., principi g., saccani e. (2013) geodynamic evolution of ophiolites from albania and greece (dinarichellenic belt): one, two, or more oceanic basins? international journal of earth science, 102(3), 783 -811. boschian g. (1999-2000) early upper pleistocene lithic industry from caverna degli orsi near san dorligo della valle (northeastern italy). atti società preistoria protostoria friuli-venezia giulia, 12 (2001), 55-65. boschian g., de santis a. (2011) bears and sedistead, different types were indiscriminately reduced to obtain a wide range of discoid flakes. the minimal presence of levallois cores or products at istraishta, eleftherohori 7, and asprochaliko along with varying quantities further north along the eastern adriatic may indicate occupational palimpsests or the interchangeable use of the two methods based on situational needs. such fluid adaptability transcends rigid technological classifications and aligns with previous discussions on the relationship between recurrent centripetal levallois and discoid core reduction methods, as well as other centripetal, though not strictly levallois, reduction strategies. acknowledgements the authors are grateful to the italian embassy and to the italian institute of culture for their assistance with the joint work. they also acknowledge gloria cattabriga and theppa mudiyanselage kalangi irushika rodrigo for revising the english text and davide margaritora for preparing figures 1, 4, and 12. funding the archaeological collaboration in albania was supported by the university of ferrara through the “startup” program (2013, 2014), the albanian institute of archaeology, and the italian ministry of foreign affairs (2014, 2015). author contributions conceptualisation: all the authors. lithic technological studies: dd, rr, mp. original draft: mb, sb, dd, rr., mp. figures: mb, rr, sb, dd. review and editing: all the authors. statements and declarations competing interests the authors declare no competing interests. references adam e. (2014) entopismós néon théseon epochís tou líthou sto nomó ioannínon. dodone xliiixliv (i), 1-15. adam e. (2019) diachronikí ekmetállefsi tou topíou sto nomó ioannínon katá tin proïstorikí período: i martyría ton lithinón technérgon. dodone xlvxlvi, 15-30. aliu s. (2020) kolonja. studime arkeologjike. jeta, kultura dhe identiteti. korçë, kotti. arrighi s., freguglia m., ranaldo f., ronchitelli a. (2009) production and use in the lithic industry of the mousterian in santa croce (bisceglie, italy). human evolution, 24(2), 91-106. badino f., ruka r., pini r., frechen m., argante v., susini d., el khair d. a., comolli r., mazzini i., delpiano d., çipa k., margaritora d., gjipali i., peresani m. (2025) palaeoenvironmental, stratigraphic and geochronological study of the coastal site of dalani i vogël (vlora, albania): new evidence for late neanderthal occupation and prehistoric archaeology. quaternary science reviews 349, 109111. bailey g., papaconstantinou v., sturdy s. (1992) asprochaliko and kokkinopilos: tl dating and reinterpretation of middle palaeolithic sites in epirus, north-west greece. cambridge archaeology journal, 2(1), 136-44. banda m., karavanić i. (2019) mustjerska industrija 24 ruka r. et al. kombewa et levallois dans l’acheuléen du maghreb et du sahara nord-occidental. in roubet c., hugot h.j., souville g. (eds.) préhistoire africaine. mélanges offerts au doyen lionel balout. editions a.d.p.f, paris, 313-321. delagnes a., rendu w. (2011) shifts in neandertal mobility, technology and subsistence strategies in western france. journal of archaeological science, 38, 1771-1783. delpiano d., heasley k., peresani m. (2018) assessing neanderthal land use and lithic raw material management in discoid technology. journal of anthropological sciences, 96, 1-22. delpiano d., peresani m. (2017) exploring neanderthal skills and lithic economy. the implication of a refitted discoid reduction sequence reconstructed using 3d virtual analysis. comptes rendu palevol, 16, 865-877. delpiano d., peresani m., pastoors a. (2017) the contribution of 3d visual technology to the study of palaeolithic knapped stones based on refitting: an application. digital applications in archaeology and cultural heritage, 4, 28-38. delpiano d., zupancich a., peresani m. (2019) innovative neanderthals: results from an integrated analytical approach applied to backed stone tools. journal of archaeological science, 110, 105011. derevianko a.p., shunkov m.v., bulatovich l., kozlikin m.b., anoikin a.a., pavlenok k.k., agadzhanyan a.k., ulianov a.v., vishnevskiy a.v. (2021) novoye v paleolitovedenii vostochnoy adriatiki. rossiysko-chernogorskiye issledovaniya v 2008-2021 godakh. novosibirsk, iaet sb ras publ. déviese t., karavanić i., comeskey d., kubiak c., korlević p., hajdinjak m., radović s., procopio n., buckley m., pääbo s., higham t. (2017) direct dating of neanderthal remains from the site of vindija cave and implications for the middle to upper paleolithic transition. proceedings of the national academy of sciences u.s.a., 114, 10606 -10611. dogandžić t. (2023) the middle paleolithic of the balkans: industrial variability, human biogeography, and neanderthal demise journal of world prehistory, 36, 257-338. dogandžić t., ðuričić l. (2017) lithic production strategies in the middle paleolithic of the southern balkans. quaternary international, 450, 68-102. dragosavac s., plavsic s., predrag r. (2021) the impact of the campanian ignimbrite (ci) eruption on palaeolithic settlement patterns in the central balkans. in babic s. (ed.) archaeology of crisis, belgrade, faculty of philosophy, university of belgrade, 25-42. duchaufour p.h. (1983) pedologie: pedogenesis and classification. mason et cie, paris-new yorkbarcelona-milan, 447. dunham r.j. (1962) classification of carbonate rocks according to depositional texture. american association of petroleum geologists 1, 108-121. đuričić l. (1997) artifacts of sandstone and limestone on the site of bioče. glasnik srpskog arheološkog društva, 13, 59-70. đuričić l. (2006) a contribution to research on bioče mousterian. glasnik srpskog arheološkog društva, 22, 179-96. durn g. (2003) terra rossa in the mediterranean rements at caverna degli orsi/medvedja jama (trieste, italy). toškan b. (eds.) fragments of ice age environments. proceedings in honour of ivan turk’s jubilee. opera instituti archaeologici sloveniae, 21, 181-207. boschian g., gerometta k., ellwood b. b., karavanić i. (2017) late neandertals in dalmatia: site formation processes, chronology, climate change and human activity at mujina pećina, croatia’. quaternary international, 450, 12-35. bourguignon l., turq a. (2003) une chaîne opératoire de debitage discoïde sur éclat du moustérien a denticulés aquitain: les exemples de champ bossuet et de combe-grenal c. 14. in peresani m. (ed.) discoid lithic technology. advances and implications. british archaeological reports international series, 1120, 131-152. brewer r.c. (1964) fabric and mineral analysis of soils. wiley, new york bronger a., sedov s.n. (2002) vetusols and palaeosols: natural versus man-induced environmental change in the atlantic coastal region of morocco. 17th world conference on soil science, paper no. 1530, 1-12. bullock p., fedoroff n., jongerius a., stoops g. j., tursina t. (1985) handbook for soil thin section description, waine research publications, albrighton. carmignani l., romagnoli f. (2017) revisione dell’industria litica musteriana di grotta mario bernardini (nardò, lecce). atti xlvii riunione scientifica preistoria e protostoria della puglia. istituto italiano di preistoria e protostoria, 139-144. chiesa s., coltorti m., cremaschi m., ferraris n., floris b., prosperi l. (1990) the loess and quaternary deposits in the marche region. in cremaschi m. (ed.) the loess in northern and central italy. centro di studio per la stratigrafia e petrografia delle alpi centrali, gutenberg, milan, 103-132. church t. (1994) lithic resource studies: a sourcebook for archaeologists. lithic technology, special publication, 3, pp. 255. courty m.a., goldberg p., macphail r.i. (1989) soils and micromorphology in archaeology, cambridge manuals in archaeology, cambridge university press. cremaschi m. (1987) paleosols and vetusols in the central po plain, a study in quaternary geology and soil development. unicopli, milan. cremaschi m. (1990) the loess in northern and central italy: a loess basin between the alps and the mediterranean regions. in cremaschi m. (ed.) the loess in northern and central italy. centro di studio per la stratigrafia e petrografia delle alpi centrali, gutenberg, milan, 15-19. daffara s., arzarello m., berruti g., berruto g., bertè d., berto c., casini a.i. (2014) the mousterian lithic assemblage of the ciota ciara cave (piedmont, northern italy): exploitation and conditioning of raw materials. journal of lithic studies, 1, 2. dakaris s.i., higgs e.s., hey r.w., tippett h., mellars p. (1964) the climate, environment and industries of stone age greece: part i. proceedings of the prehistoric society 30 (december):199244. doi: 10.1017/s0079497x00015139 dauvois m. (1981) de la simultanéité des concepts 25 istraisha, a middle palaeolithic site in southern albania island connections, in souyoudzoglou-haywood c., papoulia c. (eds.) archaeology of the ionian sea: landscapes, seascapes and the circulation of people, goods and ideas from the palaeolithic to the end of the bronze age. oxford & philadelphia, oxbow books. gjipali i. (2006) recent research on the palaeolithic and mesolithic archaeology of albania. in bejko l., hodges r. (eds.) new directions in albanian archaeology: studies presented to muzafer korkuti, international centre for albanian archaeology monograph series 1. oxbow books, 31-42. gjipali i. (2011) kërkime arkeologjike për prehistorinë e hershme në shqipërinë jugore’. in epiri antikkaonia: simpoziumi i dhe ii shkencor ndërkombëtar. universiteti ‘eqrem çabej’, gjirokastër, 33-38. gjipali i. (2012) epoka e gurit dhe shqipëria. tiranë, botart. gjipali i. (2014) stone age investigations in albania (1998-2013) in përzhita l., gjipali i., hoxha g., muka b. (eds.) proceedings of the international congress of albanian archaeological studies: 65th anniversary of albanian archaeology, tiranë: centre for albanian studies and institute of archaeology, 53-64. gowlett j.a.j., carter p.l. (1997) the basal mousterian of asprochaliko rockshelter, louros valley. in bailey g. (ed.) klithi: palaeolithic settlement and quaternary landscapes in northwest greece, vol. 1. klithi in its local and regional setting. mcdonald institute monographs, 441-458. gravina b., discamps e. (2015) mta-b or not to be? recycled bifaces and shifting hunting strategies at le moustier and their implication for the late middle palaeolithic in southwestern france, journal of human evolution, 84, 83-98. gvirtzman g., wieder m. (2001) climate of the last 53,000 years in the eastern mediterranean, based on soil-sequence stratigraphy in the coastal plain of israel. quaternary science reviews, 20/18. 1827-1849. higham t., douka k., wood r., ramsey c.b., brock f., basell l., camps m., arrizabalaga a., baena j., barroso-ruíz c., bergman c., boitard c., boscato p., caparrós m., conard n.j., draily c., froment a., galván b., gambassini p., garcia-moreno a., grimaldi s., haesaerts p., holt b., iriartechiapusso m.j., jelinek a., jordá pardo j.f., maíllo-fernández j.m., marom a., maroto j., menéndez m., metz l., morin e., moroni a., negrino f., panagopoulou e., peresani m., pirson s., de la rasilla m., riel-salvatore j., ronchitelli a., santamaria d., semal p., slimak l., soler j., soler n., villaluenga a., pinhasi r., jacobi r., (2014) the timing and spatiotemporal patterning of neanderthal disappearance. nature, 512, 306309. doi: 10.1038/nature13621 huxtable j., gowlett j.a.j., bailey g.n., carter p.l., papaconstantinou v. (1992) thermoluminescence dates and a new analysis of the early mousterian from asprochaliko. current anthropology, 33(1), 109-14. inizan m.l., reduron-ballinger m., roche h., tixier j. (1995) préhistoire de la pierre taillée t. 4 technologie de la pierre taillée. meudon, crep. gion: parent materials, composition and origin, geologia croatica, 56(1), 83-100. durn g., ottner f., slovenec d. (1999) mineralogical and geochemical indicators of the polygenetic nature of terra rossa in istria, croatia. geoderma, 91, 125-150. efstratiou n., biagi p., angelucci d. e., nisbet r. (2014) highland zone exploitation in northwestern greece: the middle paleolithic levallois sites of the pindus range of western macedonia. the saa archaeological record 14 (3), 38-42. eftimi r., sara f. (2022) quantity and quality of groundvater of intermountain basin of korça in albania and implication for sustainable management. geologìcnij žurnal, 4, 45-64. elefanti p., gilbert m. (2015) late pleistocene hominin adaptations in greece. in cowar f., wenbansmith f., pope m., hosfield r. (eds.) settlement, society and cognition in human evolution: landscapes in mind. cambridge university press, 189213. facorellis y. (2013) radiocarbon dates from archaeological sites in caves and rockshelters in greece. in mavridis f., jensen j.t. (eds.) stable places and changing perceptions: cave archaeology in greece 182, 19-72. bar international series 2558. oxford, archaeopress fao (2006) guidelines for soil description, fourth ed. fao, food and agricolture organization of the united nations, rome, pp. 97. forsén b., forsén j., lazari k., tikkala e. (2011) catalogue of sites in the central kokytos valley, in forsén b., tikkala e. (eds.) thesprotia expedition ii: environment and settlement patterns xvi, 73122. papers and monographs of the finnish institute at athens. helsinki: suomen ateenan instituutin säätiö (foundation of the finnish institute at athens) fouache e., desruelles s., magny m., bordon a., oberweiler c., coussot c., touchais g., lera p., lézine a.-m., fadin l., roger r. (2010) palaeogeographical reconstructions of lake maliq (korça basin, albania) between 14,000 bp and 2000 bp. journal of archaeological science, 37, 525-35. galanidou n. (2007) i proïstoría tis anthrópinis katagogís sti lekáni tis límnis tis kastoriás: oi martyríes apó ti syllogí pantazópoulou. to archaiologikó érgo sti makedonía kai thráki 21, 1-6. galanidou n., papoulia c. (2023) between the aegean and the adriatic: the balkan palaeolithic and the sea. in ruiz-redondo a., davies w. (eds.) the prehistoric hunter-gatherers of south-eastern europe. proceedings of the british academy, 258, oxford university press, 225-251. galanidou n., vikatou o., stavropoulou-gatsi m., vasilakis a., staikou v., iliopoulos g., veikou m., et al (2018) archaiologikí érevna epifaneías sto esoterikó archipélagos tou ioníou. in to archaiologikó érgo stin aitoloakarnanía kai ti lefkáda: praktiká 2ou diethnoús istorikoú kai archaiologikoú synedríou, i.p. 6-8 dekemvríou 2013, 445-73. mesolongi, eforeía archaiotíton aitoloakarnanías kai lefkádas. galanidou n., gatsi m., vikatou o., vasilakis a., morgan c., forsén j., staikou v., papoulia c., zervoudakis p. (2021) prehistoric settlement in the inner ionian sea archipelago and its ionian 26 ruka r. et al. pleistocene archaeology of northwestern greece: the evidence from three open-air sites and its implication for middle and upper palaeolithic hunter-gatherers activity and behaviour in southeastern europe. journal of greek archaeology, 2 (january), 1-32. ligkovanlis s. (2018) neanderthals kai homo sapiens katá to anótero pleistókaino sti voreiodytikí elláda. néa stoicheía apó laxevménes lithologíes pétra ton ypaíthrion chóron tis thesprotías. in to archaiologikó érgo sti voreiodytikí elláda kai ta nisiá tou ioníou: ioánnina; praktiká, 237-48. ligkovanlis s., kourtessi-philippakis g. (2022) palaeolithic chipped stone industries from zakynthos, ionian islands, greece. interpreting the new evidence within the western greek and adriatic context. in souyoudzoglou-haywood c., papoulia c. (eds.) archaeology of the ionian sea: landscapes, seascapes and the circulation of people, goods and ideas from the palaeolithic to the end of the bronze age, 41-51. oxford & philadelphia, oxbow books. ligkovanlis, s., iliopoulos g., palli o., tzortzatou a., tsakanikou p. (2022) palaeolithic artifact taphonomy in terra rossa sites at northwestern greece revisited: two new case studies. mediterranean archaeology and archaeometry 22(3), 215-29. lindhorst k., krastel s., reicherter k., stipp m., wagner b., schwenk t. (2015) sedimentary and tectonic evolution of lake ohrid (macedonia/albania). basin research, 27(1), 84-101. lópez-garcía j.m., dalla valle c., cremaschi m., peresani m. (2015) reconstruction of the neanderthal and modern human landscape and climate from the fumane cave sequence (verona, italy) using small-mammal assemblages. quaternary science reviews 128, 1-13. lowe j., barton n., blockley s., bronk ramsey ch., cullen v.l., davies w., gamble c., grant k., hardiman m., housley r., et al. (2012) volcanic ash layers illuminate the resilience of neanderthals and early modern humans to natural hazards. proceedings of the national academy of sciences, 201204579. macleod d.a. (1980) the origin of the red mediterranean soils in epirus, greece. journal of soil science, 31, 125-136. marciani g., ronchitelli a., arrighi s., badino f., bortolini e., boscato p., boschin f., crezzini j., delpiano d., falcucci a. (2020) lithic technocomplexes in italy from 50 to 39 thousand years bp: an overview of lithic technological changes across the middle-upper palaeolithic boundary. quaternary international 551, 123-149. doi: 10.1016/j.quaint.2019.11.005 merino e., banerjee a., dworkin s. (2006) dust, terra rossa, replacement, and karst: serendipitous geodynamics in the critical zone. geochimica et cosmochimica acta, 70, (18), a416. mihailović d. (2020) push-and-pull factors of the middle to upper paleolithic transition in the balkans. quaternary international, 551, 47-62. mihailović d. (2024) middle paleolithic assemblages from crvena stijena: insights from the 1954-1963 excavations. prehistoric settlements in caves and rock-shelters of serbia and montenegro, fasciiuss working group wrb (2015) world reference base for soil resources 2014, update 2015 international soil classification system for naming soils and creating legends for soil maps, world soil resources reports 106, fao, rome. karavanić i. (2004) the middle paleolithic settlement of croatia. in conard n. j. (ed.) settlement dynamics of the middle palaeolithic and middle stone age. tübingen publications in prehistory, introductory volume. tübingen, kerns verlag, 185-200. karavanić i., banda m. (2023) the middle palaeolithic of south-eastern europe. in ruiz-redendo a., davies w. (eds.) the prehistoric hunter-gatherers of south-eastern europe. proceedings of the british academy 258. oxford university press, 60106. karavanić i., miracle p.t., culiberg m., kurtanjek d., zupanič j., golubić v., paunović m., lenardić j.m., malez v., šošić r., janković i., smith f.h. (2008) the middle paleolithic from mujina pećina, dalmatia, croatia. journal of field archaeology, 33(3), 259-77. karavanić i., hellstrom j., rabeder g., vukosavljević n., banda m., smith f.h. (2021) new u-th dates from vindija, velika pećina (kličevica) and mujina pećina and their implications for chronology of the middle paleolithic in croatia. collegium antropologicum, 45(1), 1-10. karavanić i., bronić i.k., sironić a., radović s., banda m., smith f.h. (2024) chronology of hominin activity at vindija cave, croatia: new dates recorded via standard and ultrafiltration ams. antiquity, 98(398), e7. klein c. (1999) manual of mineralogy. john wiley & sons inc, new york. kuhn s.l. (1995) mousterian lithic technology: an ecological perspective. princeton university press. kourtessi-philippakis g. (1986) le paléolithique de la grèce continentale: état de la question et perspectives de recherche. histoire ancienne et médiévale 16. paris, éditions de la sorbonne. ligkovanlis s. (2011) megalo karvounari revisited. in thesprotia expedition ii: environment and settlement patterns, edited by björn forsén and esko tikkala, xvi,159-80. papers and monographs of the finnish institute at athens. helsinki, suomen ateenan instituutin säätiö (foundation of the finnish institute at athens). ligkovanlis s. (2013) a rare case of “technological connectivity” across the adriatic sea during the middle palaeolithic: the eleftherochori 7 mousterian lithic assemblage in its south/southeast european context. in bombardieri l., d’agostino l., guarducci g., orsi v., valentini s. (eds.) soma 2012 identity and connectivity. proceedings 16th symposium on mediterranean archaeology, florence, bar international series 2581. oxford, archaeopress, ii, 645-56. ligkovanlis s. (2016) on lithic technology terms and semantics. the example of the asprochaliko rockshelter middle palaeolithic stone industry. in elefanti p., andreasen n., kardulias p.n., marshall g. (eds.) lithics past and present. perspectives on chipped stone studies in greece. studies in mediterranean archaeology. uppsala, åströms förlag, cxliv, 95-110. ligkovanlis s. (2017) new insights into the upper 27 istraisha, a middle palaeolithic site in southern albania ish institute at athens. helsinki, suomen ateenan instituutin säätiö (foundation of the finnish institute at athens). pavlenok k.k., kozlikin m.b., kandyba a.v., bulatović l., derevianko a.p., shunkov m.v. (2017) style, deficit or reduction? analysing the bioče micromousterian. quartär, 64, 95-106. peresani m. (1998) la variabilité du débitage discoïde dans la grotte de fumane (italie du nord). paléo 10, 123-146. peresani m. (ed.) (2003) discoid lithic technology. advances and implications. british archaeological reports, international series, 1120. peresani m. (2003) an initial overview of the middle palaeolithic discoid industries in central-northern italy. in peresani m. (ed.) discoid lithic technology. advances and implications. british archaeological reports, international series, 1120, 209223. peresani m. (2022) inspecting human evolution from a cave. late neanderthals and early sapiens at grotta di fumane: present state and outlook. journal of anthropological sciences, 100, 71-107. peresani m., tozzi c. (2018) il paleolitico e il mesolitico del friuli-venezia giulia: quarant’anni di studi e ricerche. in borgna e., càssola g.p., corazza s. (eds.) preistoria e protostoria del caput adriae, atti xlix riunione scientifica istituto italiano di preistoria e protostoria. studi di preistoria e protostoria, 5, 45-59. peresani m., romandini m., duches r., jéquier c., nannini n., pastoors a., picin a., schmidt i., vaquero m., weniger g.c. (2014) new evidence for the mousterian and gravettian at rio secco cave, italy. journal of field archaeology, 39/4, 401-416. peresani m., boldrin m., pasetti p. (2015) assessing the exploitation of double patinated artifacts during the late mousterian. implications for lithic economy and human mobility in the north of italy. quaternary international 361, 238-250. peresani m., gjipali i., romandini m., ruka r. (2016) shqipëria jug-perëndimore, një korridor gjatë paleolitit për në brigjet veriore të mesdheut. in lepore g. (ed.) qytetet antike dhe peizazhi në shqipëri: një shekull kërkimesh arkeologjike italo -shqiptare. muzeu historik kombëtar. adrias. bari, edipuglia, 12, pp. 159-63. peresani m., monegato g., ravazzi c., bertola s., margaritora d., breda m., fontana a., fontana f., janković i., karavanic i., komšo d., mozzi p., pini r., furlanetto g., de amicis g.m., perhoč z., posth c., ronchi l., rossato s., vukosavljević n., zerboni a. (2021) hunter-gatherers across the great adriatic-po region during the last glacial maximum: environmental and cultural dynamics. quaternary international, 581-582, 128-163. radovanović i. (1986) novija istraživanja paleolita i mezolita u crnoj gori. glasnik srpskog arheološkog društva, 3, 63-77. rapp a. (1984) are terra rossa soils in europe eolian deposits from africa? geologiska foreninges et stockholm forhandlingar 105, 161-168. rolfo m.f., ceruleo p., marra f., jicha b., gatta m. (2022) exploring the lithic variability of the mousterian (mis 9-3) open-air sites of the pontine plain (central italy). journal of paleolithic archaeology, cule iii. faculty of philosophy, university of belgrade, center for archaeological research. mihailović d., mihailović b.r. (2023) chronology and succession of palaeolithic technocomplexes in serbia. zbornik narodnog muzeja archeologija, 26(1), 11-37. mihailović d., whallon r. (2017) crvena stijena revisited: the late mousterian assemblages. quaternary international, 450, 36-49. monnier g., tostevin g., pajović g., borovonić n., baković m. (2020) nova istraživanja paleolitskog nalazišta crvena stijena, istorijski kontekst. istorijski zapisi xciii, (1-2), 71-108. morley m.w., woodward j.c. (2011) the campanian ignimbrite (y5) tephra at crvena stijena rockshelter, montenegro. quaternary research, 75(3), 683-96. mourre v. (2003) discoïde ou pas discoïde? réflexions sur la pertinence des critères techniques définissant le débitage discoïde. in peresani m. (ed.) discoid lithic technology. advances and implications. british archaeological reports, international series, 1120. munsell color (2009) munsell soil color charts revised edition, new windsor, munsell® color. murphy c.p. (1986) thin section preparation of soils and sediments. ab academic publishers, berkhamsted, pp. 149. nelson e. (1997) radiocarbon dating of bone and charcoal from divje babe i cave. in turk i. (ed.) mousterian ‘bone flute’ and other finds from divje babe i cave siet in slovenia. opera instituti archaeologici sloveniae 2. ljubljana, znanstvenoraziskovalni center sazu, 51-54. nicosia c., stoops g. (2017) archaeological soil and sediment micromorphology, chichester, wiley blackwell, pp. 475. palombo m.r., mussi m. (2006) large mammal guilds at the time of the first human colonization of europe: the case of the italian pleistocene record. quaternary international 149, 94-103. papaconstantinou v., vassilopoulou d. (1997) the middle palaeolithic industries of epirus. in klithi: palaeolithic settlement and quaternary landscapes in northwest greece. vol. 2: klithi in its local and regional setting, edited by geoff bailey, 459-80. mcdonald institute monographs. cambridge, mcdonald institute for archaeological research. papadea a. (2019) anazitóntas tous palaiolithikoús anthropídes sta vouná tis thesprotías: oi ypaíthries théseis eleftherochóri 1 kai 3. in chouliaras ioannis p. & g.th. pliakou g. (eds) thesprotia i. proceedings 1st international conference on the archaeology and history of thesprotia. ioannina, ministry of culture and sports, ephorate of antiquities of thesprotia, pp. 21-36. papagianni d. (2000) middle palaeolithic occupation and technology in northwestern greece: the evidence from open-air sites. bar international series 882. oxford, bar publishing. papoulia c. (2011) mikro karvounari in context: the new lithic collection and its implications for middle palaeolithic hunting activities. in thesprotia expedition ii: environment and settlement patterns, edited by björn forsén and esko tikkala, xvi, 123-58. papers and monographs of the finn 28 ruka r. et al. 438. sherreiks r., boudagher-fadel m. (2021) the closure of the vardar ocean (the western domain of the northern neotethys) from early middle jurassic to paleocene time, based on surface geology of eastern pelagonia and the vardar zone, biostratigraphy, and seismic-tomographic images of the mantle below the central hellenides. ucl open, environment preprint. shunkov m.v., anoikin a.a., kozlikin m.b., bulatovich l., derevianko a.p. (2021) mnogosloynaya paleoliticheskaya stoyanka malishina stena v chernogorii: rezul’taty issledovaniy (2021) goda. problemy arkheologii, etnografii, antropologii sibiri i sopredel’nykh territoriy, 27, 349-54. simek j. (1991) stone tool assemblages from krapina (croatia, yugoslavia). in montet-white a. and holen s. raw material economies among prehistoric hunter-gatherers. university of kansas publications in anthropology 19. lawrence: university of kansas press, 59-72. simek j.f., smith f.h. (1997) chronological changes in stone tool assemblages from krapina (croatia). journal of human evolution, 32(6), 56175. skarpelis n, (2020) silcrete and chert as source rocks of early prehistoric artifacts: the case of central evia (greece). mediterranean archaeology and archaeometry, 21(1), 1-19. soil survey staff (2014) keys to soil taxonomy, 12th ed. usda-natural resources conservation service, washington dc, pp. 360. stojanovski d., arzarello m., nacev t. (2018) middle paleolithic stone-tool technology from the central balkans: the site of uzun mera (eastern republic of macedonia). quaternary international, 476 (may), 63-69. stoops g. (2021) guidelines for analysis and description of soil and regolith thin sections, 2nd edition, wiley & sons, inc, pp. 240. stoops g., marcelino v., mees f. (eds) (2018) interpretation of micromorphological features of soils and regoliths, 2nd edition, amsterdam, elsevier. šušnjara a., šćavničar b., gabrić a. (1994) the occurrence of vitric tuff in the quaternary deposits of gljev in dalmatia (southern croatia). geologia croatica, 47(2), 193-198. tagari d., vergely p., aliaj s. (1993) tectonique polyphasée plio-quaternaire en albanie orientale (région de korça-pogradeçi). bulletin de la société géologique française, 164(5), 727-737. torrent j. (2005) mediterranean soils. encyclopedia of soils in the environment, 2, 418-27. tourloukis v. (2021) palaeolithic archaeology: a review of recent research.” archaeological reports 67, 61-79. turk m. (2014) tipologija kamnitih artefaktov. in turk i. (ed.) divje babe i: upper pleistocene palaeolithic site in slovenia, part 2: archaeology. opera instituti archaeologici sloveniae 29. ljubljana, zrc sazu, založba zrc, 153-70. turk m., turk i. (2014) tehnologija, uporabljena pri izdelavi artefaktov. in turk i. (ed.) divje babe i: upper pleistocene palaeolithic site in slovenia, part 2: archaeology. opera instituti archaeologici sloveniae 29. ljubljana, zrc sazu, založba zrc, 57-78. 5, 1-28. romagnoli f., chabai v., gravina b., hérisson d., hovers e., moncel m.h., peresani m., uthmeier t., bourguignon l., chacón m.g., di modica k., faivre j.p., kolobova k., malinski-buller a., neruda p., rios garaizar j., weiss m., wiśniewski a., wragg sykes r. (2022) neanderthal technological variability: a wide-ranging geographical perspective of the final middle palaeolithic. in romagnoli f., rivals f., benazzi s. (eds.) updating neanderthals. elsevier monographies, 163-204. ruka r. (2018) an overview on early prehistoric evidence from the korça basin’. in lamboley j.-l., përzhita l., skënderaj a. (eds.) l’illyrie méridionale et l’epire dans l’antiquité, actes du vi colloque international de tirana (20-23 mai 2015). tiranë, alsa. ruka r. (2023) the lithic assemblages. in archaeological investigations in a northern albanian province: results of the projekti arkeologjik i shkodres (pash): volume two: artifacts and artifact analysis, edited by michael l. galaty and lorenc bejko, 1-43. memoirs of the museum of anthropology, university of michigan 64. ann arbor, michigan, university of michigan museum of anthropological archaeology. doi: 10.3998/mpub.12208577 ruka r., gjipali i., galaty m.l., bajramaj n. (2014) lithics at one end of circum-adriatic: case studies from the southernmost albanian coastal lowland. in përzhita l., gjipali i., hoxha g., muka b. (eds.) proceedings of the international congress of albanian archaeological studies, 65th anniversary of albanian archaeology (21-22 november, tirana 2013), 93-106. tiranë, centre for albanian studies and institute of archaeology. runnels, c., korkuti m., galaty m. l., timpson m. e., stocker s. r., davis j. l., bejko l., and muçaj s. (2009) early prehistoric landscape and landuse in the fier region of albania. journal of mediterranean archaeology 22 (2), 151-82. doi: 10.1558/jmea.v22i2.151 salamanov-korobar l. (2008) first paleolithic research in the r. macedonia (fyrom): the cave golema pesht near the village zdunje preliminary results. in darlas a., mihailović d. (eds.) the palaeolithic of the balkans, proceedings of the xv world congress uispp (lisbon, 4-9 september 2006). bar international series 1819. oxford, archaeopress, 17, 85-92. šalamanov-korobar l. (2019) analiza na delkanite kameni artefakti od srednopaleolitskite sloevi vo pešterata golema pešt’. macedoniae acta archaeologica, 21, 11-36. sarti l., romagnoli f., carmignani l., martini f. (2017) grotta del cavallo (scavi sarti): tradizione e innovazione nella sequenza musteriana sulla base dell’indicatore litico, studi di preistoria e protostoria (4), preistoria e protostoria della puglia, 131138. schmidt s.m., bernoulli d., fügenschuh b., matenco l., schefer s., schuster r., tischler m., ustaszewski k. (2008) the alpine-carpathian-dinaridic orogenic system: correlation and evolution of tectonic units. swiss journal of geosciences, 01, 139-183. schwertmann u.t.r.m., taylor r.m. (1989) iron oxides. minerals in soil environments 1(1989), 379 29 istraisha, a middle palaeolithic site in southern albania xhomo a., kodra a., xhafa z., shallo m. (2002) gjeologjia e shqipërisë. stratigrafia, magmatizmi, metamorfizmi, tektonika, neotektonika dhe evolucioni paleogjeografik dhe gjeodinamik, tirana, pp. 464. yaalon d.h. (1997) soils in the mediterranean region: what makes them different? catena, 28, 157-169. yonekura k., hasegawa h., hotta a., suzuki t. (2008) a novel approach to studies of prehistoric exploitation of stone tools materials using material composition, surface morphology, microstructure and mechanical properties, archaeometry, 50/5, 727746. turq a., faivre j.p., gravina b., bourguignon l. (2017) building models of neanderthal territories from raw material transports in the aquitaine basin (southwestern france). quaternary international, 433, 88-101. vishnevskiy a.v., pavlenok k.k., kozlikin m.b., ulyanov v.a., derevianko a.p., shunko m.v. (2019) a neanderthal refugium in the eastern adriatic. archaeology, ethnology & anthropology of eurasia, 47(4), 3-15. vujević d. (2009) the relationship between the middle palaeolithic sites in the zadar hinterland and the zadar islands. in forenbaher s. (ed.) a connecting sea: maritime interaction in adriatic prehistory. bar international series 2037. oxford, archaeopress, 1-11. vujević d., perhoč z., ivančić t. (2017) micromousterian in northern dalmatia. quaternary international, 450, 50-67. vukosavljević n., gužvica g., radanović-gužvica b., kurtanjek d., karavanić i. (2022) mousterian lithic assemblage from vinica cave (hrvatsko zagorje, croatia) new insights into regional middle paleolithic technological behavior. arheološki vestnik, 73, 7-28. 30 ruka r. et al. ms. received: october 11, 2024 revised: january 21, 2025 accepted: march 2, 2025 available online: march 14, 2025 imp.gordini& dinamica morfologica del litorale del delta del fiume tagliamento (adriatico settentrionale) in relazione ai possibili interventi di ripascimento emiliano gordini1, ruggero marocco2 & riccardo ramella1 1 istituto nazionale di oceanografia e di geofisica sperimentale ogs, trieste. (e-mail : egordini @ ogs.trieste.it; rramella @ ogs.trieste.it) 2 dipartimento di scienze geologiche, ambientali e marine, università degli studi di trieste. (e-mai : marocco @ units.it). riassunto: gordini e., marocco r., ramella r., dinamica morfologica del litorale del delta del fiume tagliamento (adriatico settentrionale) in relazione ai possibili interventi di ripascimento. (it issn 0394-3356, 2006). l’analisi morfodinamica delle spiagge del delta del f. tagliamento, dove insistono due delle località balneari più importanti dell’alto adriatico, ha messo in evidenza l’esistenza di tratti di litorale soggetti ad endemica erosione, altri in progressione ed altri ancora tendenzialmente stabili. rilievi topo-batimetrici di 66 profili perpendicolari alla spiaggia emersa, intertidale e sottomarina, eseguiti su scala annuale nel 2002-2003 (da un periodo estivo di ripascimento della spiaggia ciclo estivo o swale ad uno di erosione invernale ciclo invernale o storm) e il loro confronto con le risultanze dei studi precedenti hanno permesso di definire che nell’ambito della spiaggia sottomarina le variazioni stagionali e quelle pluriennali sono minime ad eccezione dei tratti in corrispondenza delle aree di foce e di bocca lagunare. qui si assiste ad un incremento dei fondali che beneficiano della deflessione del trasporto lungo riva a causa del pennello liquido dei flussi lagunari e fluviali. nell’area più dinamica della spiaggia sottomarina (zona delle barre e dei truogoli), poi, le variazioni sono determinate essenzialmente da semplici traslazioni delle barre verso terra e verso mare, senza perdite o guadagni volumetrici. diversa è invece la situazione lungo le spiagge intertidali ed emerse dove le variazioni sono sensibili e determinate a volte da cause naturali (scarsità di alimentazione lungo riva, incidenza del moto ondoso, ecc) ma anche dallo stratificarsi nel tempo di opere di difesa marittima diverse, costruite per finalità più disparate e oggi non completamente funzionanti. la situazione più drammatica è stata riscontrata nell’area fociale del tagliamento, dove gran parte delle sponde e dei tratti di spiaggia apicali sono soggetti ad intensa erosione, mentre complessivamente, le spiagge sottomarine immediatamente adiacenti sono in progressione (con un incremento di ca. 0,085 m3/m2). le aree in accumulo risultano essere particolarmente localizzate al centro del fronte deltizio e al suo lato oriente, poco a se dalla testata di un pennello di sbarramento. l’analisi a medio e lungo termine delle variazioni volumetriche in quest’area, risultanti dal confronto con rilievi precedenti (brambati 1987), eseguiti nel 1969 e nel 1985, hanno permesso di definire che dopo una prima fase di accrescimento delle spiagge intertidali ed emerse ed un approfondimento di quelle sottomarine (1969-1985) si è passati ad una situazione diametralmente opposta (1985-2002) che permane fino ad oggidì. in questa condizione, data la necessità di reperire sedimenti per un urgente ripascimento delle spiagge in erosione (circa 50.000 m3 anno) e di garantire il passo marittimo della foce, si ritiene che oltre alla porzione esterna dell’alveo fluviale che deve essere risagomato e approfondito (68.000 m3 e 166.000 m3 per raggiungere rispettivamente le profondità di 2,5 e 3,5 m ed una larghezza di 100-150 m) una parte di questo materiale (circa 90.000 m3) può essere prelevato dalle aree in accumulo rilevate da questo studio che oltre ad essere poste in vicinanza della foce, sono soggette a ricarica annuale. abstract: gordini e., marocco r., ramella r., morphological dynamics of the littoral zone of the tagliamento river delta (northern adriatic sea) related to eventual nourishment works. (it issn 0394-3356,2006). the morphodynamic analysis of the tagliamento river delta beaches, where two of the most important holiday sites of the upper adriatic sea are located, revealed some areas undergoing endemic erosion, some of which are presently under accretion, and others that appear to be stable. sixtysix topographic and bathymetric profiles orthogonal to the emerged, inter-tidal and submerged portions of the beaches were obtained during 2002 and 2003. comparison to results from earlier studies showed that seasonal and multiyear variations in the submerged areas are very low, except for the zones located in correspondence to the river mouth and the tidal inlet. here, the thickness of the sea floor sediment cover increases due to the deviation of the alongshore sediment transport as a consequence of both the tidal and fluvial outflows from the lagoon. in the most dynamic areas of the submerged beaches (bars and troughs), the sediment thickness variations are mainly represented by the outward and inward movements of the bars without net sediment volume losses or gains. a different situation has been identified in correspondence to the inter-tidal and emerged zones, where the variations are more conspicuous and are due not only to natural phenomena (limited alongshore feeding, waves etc.) but also to several coastal protection structures (constructed in the past for different purposes) that are not very effective. the worst situation has been found at the tagliamento river mouth where most of the river levees and the apical beach areas are undergoing intense erosion. instead, the adjacent submerged beaches are in general presently accreting (a global increase of 490.000 m3). the areas characterized by sediment accretion are mainly located in the central sector of the delta front and at its eastern side, southeast of a groin. the volumetric variations in the area have been analyzed over both short and long time-scales, and the resulting information has been confronted with those obtained from previous studies carried out in 1969 and in 1985 (brambati, 1987). this defined that, after a first accretion phase of the inter-tidal and exposed parts and of a deepening of the submerged portions of the beaches (1969 -1985), a completely different regime set in (1985-2002) which appears to characterize the present situation. a sediment supply in the order of about 50.000 m3/yr is urgently necessary to replenish the eroded beaches. sediment could be extracted from the river fan which presently has to be re-shaped and deepened for safe navigation (68.000 m3 or 166.000 m3 depending on whether a water depth of 2,5 m or 3,5 m is required, and a width roughly ranging from 100 m to 150 m). part of this material (90.000 m3) could also be obtained from the accretion areas, characterized currently by annual feedings, that were identified in the present study. parole chiave: dinamica costiera, ripascimento, delta fiume tagliamento, adriatico settentrionale, italia. keywords: coastal dynamics, nourishment, delta tagliamento river, northern adriatic sea, italy. il quaternario italian journal of quaternary sciences 19(1), 2006 45-65 46 e. gordini, r. marocco & r. ramella 1. introduzione oggigiorno diventa sempre più pressante individuare cave di prestito di sedimenti sabbiosi o ghiaiosi per cercare di porre rimedio alla ormai endemica erosione dei litorali, provocata a volte da cause naturali, ma anche e soprattutto dall’alterazione degli equilibri costieri da parte dell’uomo. in questa problematica, dettata anche da criteri d’estrema urgenza, rivestono particolare rilevanza gli studi di dinamica costiera finalizzati alla definizione delle modalità ottimali d’intervento, fermo restando la salvaguardia paesaggistica ed estetica dell’ambiente costiero. per far ciò spesso ci si avvale della tecnica di ripascimento artificiale delle spiagge che prevede il prelievo di opportuni accumuli sabbiosi in mare, rappresentati quasi sempre dalle sabbie di piattaforma, dalle barre di foce e dei delta di bocca lagunare e, buon ultimo, da cave a terra. esiste oggi una nutrita letteratura in merito che si rifà ai primi interventi nelle aree liguri, toscane, laziali e venete (cfr. ad esempio, capobianco et al., 1999), sino alle recenti sistemazioni costiere che ormai ricoprono gran parte del territorio nazionale con una mobilitazione di volumi di materiale per diversi milioni di m3 (di cui ca. 6 milioni per i soli litorali di pellestrina e cavallino nel veneto; de girolamo et al., 1999). fatte salve tutte le valutazioni sugli impatti ambientali che tali operazioni comportano, e l’annoso problema del mantenimento di questi materiali con opere di difesa “morbide” o “pesanti” o alla loro ricarica periodica, il provvigionamento di questi materiali può essere ricercato, come detto, a mare, a breve o lunga distanza dalla costa, oppure nell’ambito della fascia litorale stessa, attingendo anche a spiagge emerse in eccessivo accrescimento o ai passi marittimi che abbisognano di continue escavazioni. va rimarcato che in questo contesto non vanno assolutamente toccati gli accumuli eolici costieri che sono stati recentemente molto compromessi a seguito delle estrazioni e sbancamenti eseguiti a scopi edilizi che hanno determinato la costruzione di agglomerati urbani a nastro sull’intera linea di costa. le dune, che oltretutto fanno parte integrante e fissano la parte alta della spiaggia, vanno pertanto tutelate, preservate e possibilmente accresciute, non solo per il loro naturale valore paesaggistico ed ambientale, ma anche perché rimangono, a volte, l’ultimo baluardo costiero per contrapporsi alle mareggiate più violente e, a meso o macro scala temporale, alla paventata ingressione marina (prossima ventura). d’altro verso le sabbie di piattaforma dell’alto adriatico (che si ubicano mediamente dai 13 ai 25 m di profondità) rappresentano serbatoi molto estesi, quasi sempre poco potenti e a scarso rinnovo, poiché ereditati e rielaborati dall’ingressione marina quaternaria e limitatamente toccati dalle ondazioni attuali. ospitano inoltre una ricca popolazione di molluschi eduli e diffusi affioramenti rocciosi (gordini et al., 2004) che sono una delle ricchezze più ambite dai pescatori dell’intero comparto adriatico e pertanto difficilmente utilizzabili a questi fini senza innescare conflitti sociali. più interessanti, allora, rimangono i potenziali serbatoi sotto costa che oltre ad avere il pregio della loro vicinanza dal litorale, sono di per sé serbatoi rinnovabili in quanto ricaricati dal “nastro trasportatore litorale” e per questo, spesso scavati per mantenere officiosi i passi marittimi del retroterra. va da sé che questi serbatoi rappresentano almeno in casi di normale ripristino e conservazione di un litorale una delle soluzioni ideali, anche perché non modificano il complessivo bilancio volumetrico dell’unità fisiografica del paraggio. anche questo intervento, comunque, deve essere valutato attentamente in funzione della previsione dei tempi di ricarica delle cave di prestito e della quantità-qualità del materiale prelevabile. si rimarca che l’escavazione in queste aree comporta almeno teoricamente un duplice beneficio; la ricostruzione delle spiagge, da un lato, e la garanzia dell’accesso ai porti turistici, dall’altro, infrastrutture queste che rappresentano oggi una componente essenziale nell’offerta turistica di una località balneare. il presente studio intende investigare nell’ambito di un sistema complesso come quello del delta del f. tagliamento che ospita due tra le località turistiche più rinomate dell’alto adriatico (lignano nel friuli venezia giulia e bibione nel veneto), le potenzialità a breve e medio termine dell’utilizzo dei serbatoi naturali di depositi rappresentati dalla foce e dalle bocche lagunari per intervenire con ripascimenti artificiali sui tratti di litorale in forte erosione. queste possibili strategie d’intervento saranno adottate solamente dopo la definizione delle caratteristiche morfodinamiche del paraggio e il contesto evolutivo dei fondali di spiaggia (oggetto di questo studio) e della caratterizzazione sedimentologica e chimico-ambientale dei depositi sabbiosi da utilizzare, sancita dalle leggi vigenti (legge 179 del 2003). la scelta del delta del tagliamento come area campione per questa analisi è stata determinata in primo luogo dalla richiesta da parte delle amministrazioni locali di inquadrare sotto questa problematica le loro zone di competenza e in secondo luogo dalla possibilità di confrontare i risultati dei rilievi morfologici attuali con le risultanze di una nutrita serie di studi precedenti (vedi soprattutto zunica 1971, brambati 1987 e più recentemente, fontolan 2004) che permettono una visione panoramica e uno spessore cronologico delle fenomenologie dinamico-costiere rilevate nell’arco di un anno e in condizioni deposizionali erosive differenti (swale storm). 2. il delta del f. tagliamento l’area costiera oggetto dello studio è incentrata sulle coste basse e sabbiose del delta bilobato del tagliamento che rappresenta uno dei sistemi fluviali più importanti dell’italia settentrionale. si ubica geograficamente a cavallo della regione friuli venezia giulia (est) e veneto (ovest) tra i golfi di trieste e quello di venezia; il suo limite meridionale viene convenzionalmente posto lungo la batimetrica 8, approssimativamente lungo una rotta parallela alla costa ad una distanza di circa 3 km da essa. il litorale espone le sue spiagge a diversi regimi di vento e conseguentemente di moto ondoso. il suo regime anemometrico è governato dallo spirare dei venti del i° quadrante e soprattutto di quello di bora (ene, prevalentemente nella stagione invernale e autunnale). per quanto concerne i venti meridionali, lo scirocco, dopo la bora, è il vento che può raggiungere le massime velocità nel paraggio; segue il libeccio, che spira da so, con frequenza di poco inferiore a quella dello scirocco (essenzialmente dalla primavera all’estate). nel periodo estivo l’area è inoltre interessata da venti settentrionali prevalentemente a carattere diurno provenienti dal iv° quadrante (termiche estive). il mare regnante risulta essere quello di bora, che risente di considerevoli rifrazioni prima di giungere sulla battigia, mentre quello dominante è di scirocco, con in subordine i l mare di libeccio (catani, marocco, 1976; brambati, 1987). le maree sono tra le più ampie del mediterraneo. in situazione di sizigia (onde semidiurne) raggiungono un’escursione media a trieste di 86 cm (100 cm a venezia); in quadratura (onde diurne) un’escursione media di 22 cm (20 cm a venezia). casi eccezionali di acqua alta, hanno fatto registrare valori di 130 cm con valori estremi attorno ai 200 cm (marocco, pessina, 2000). la circolazione media del bacino è ciclonica con corrente ascendente lungo le coste croate e discendente lungo quelle italiane. studi condotti sull’evoluzione recente della fascia costiera hanno dimostrato che il delta attuale del tagliamento si è formato circa 2.000 anni fa a seguito di una diversione orientale del fiume che ha disseccato la paleolaguna di marano. la formazione del delta non si è realizzata con una progradazione graduale, ma con rapidi accrescimenti intervallati da fasi erosive e di stabilità (marocco, 1988; 1989; 1991). dalla cartografia storica analizzata con grande perizia da zunica (1971) emerge che dal 1644 al 1868 il delta ha subito profonde modifiche, in parte determinate da fattori naturali e dal regime meteo-marino del momento e in parte dall’uomo che ha modificato profondamente il territorio con opere di bonifica, tombamenti, arginature e continue regimazioni fluviali. per quanto attiene alla forma bialare del delta, il confronto delle carte prese in esame mette in risalto che le maggiori modificazioni si sono avute sull’ala destra del delta. segnatamente da una conformazione tozza e convessa verso mare del litorale (situazione del 1822) si passa, in un lasso di soli 46 anni, ad una accentuata concavità, particolarmente evidente nella sua porzione centro-occidentale a testimonianza del succedersi di eventi erosivi. si avverte anche una sensibile migrazione dell’asta terminale del fiume, con una prima e modesta rotazione verso levante, seguita, successivamente, da traslazioni verso ponente, tendenza, questa, che viene mantenuta anche attualmente. l’accrescimento della foce ha dunque mantenuto nel tempo un asse di direzione so. lo stesso autore specifica, inoltre, che il massimo arretramento dell’ala deltizia si è realizzato in un brevissimo periodo dal 1822 al 1833, seguito da graduali avanzamenti che nel 1868 riportano il litorale alla condizione di partenza, per poi superarla nel 1903. nello stesso intervallo temporale il rimanente tratto di litorale risulta sensibilmente più stabile, mentre fa registrare un forte incremento alla fine del secolo. dalle evidenze sopra esposte, considerate dovutamente le incertezze del metodo, emerge che il delta non ha avuto un ciclo evolutivo continuo nell’arco di tempo considerato, ma un’intermittenza di fasi particolarmente evidenti nell’ala destra. l’analisi delle varie edizioni delle tavolette i.g.m. (dal 1937 al 1951) confermano gli andamenti della costa dedotti dalle carte più antiche con una maggiore dinamicità dell’ala destra rispetto a quella sinistra, dove continuano periodi di cospicuo ripascimento, intervallati da altri di intensa attività erosiva. le diverse levate rendono particolarmente manifesto il meccanismo di 47dinamica morfologica del litorale ... accrescimento del delta che si attua con un progressivo saldamento di scanni sabbiosi alla battigia e la migrazione delle barre sottomarine sempre verso ovest, che vanno ad implementare quelle del delta inlet di punta baseleghe. anche brambati (1987), sulla base del confronto delle linee di riva riportate nei rilievi del 1891, 1978 e 1985, conferma l’ evoluzione dell’ala sinistra del tagliamento sottolineando l’accentuato sviluppo del lobo orientale della foce, in controtendenza all’erosione del tratto di litorale che si estende fino a lignano riviera. più ad est di questa località, fino alla bocca di lignano, risalta anche in questo caso, a livello secolare, una forte progressione della spiaggia. più recentemente, fontolan (2004) a riguardo dell’ala occidentale del delta evidenzia, riprendendo i dati di brambati, come nel 1968 per contrastare la forte erosione che, nella parte più prossima alla foce, poneva in pericolo la struttura del faro, furono costruiti tre frangiflutti in massi che, nei mesi successivi, favorirono un discreto accumulo di sabbie (brambati, 1970). sempre l’autore rimarca come la tendenza evolutiva del litorale sia rappresentata da una marcata fase erosiva del settore prossimo alla foce, il cui materiale, seguendo il verso della corrente di deriva principale, subisce un trasporto prevalente verso ovest. una parte di esso va a depositarsi nella porzione centrale del lobo occidentale deltizio, esattamente sul fronte della parte maggiormente urbanizzata: l’altra concorre all’accrescimento verso occidente del sistema bocca di porto baseleghe. significativa risulta anche la parziale distruzione dell’apparato dunare in corrispondenza della lama di revelino e di punta faro, anche se recentemente difeso da frangiflutti in continua risagomatura e prolungamento. anche il fronte delle dune litorali, fissato negli anni ’ 90 da sacchi di geotessile sovrapposti, risulta oggi fortemente compromesso, al di là delle viminate e dei sacconi di sabbia posti a loro difesa. in questa area la linea di riva ha subito un forte arretramento, con la completa scomparsa della spiaggia emersa, l’erosione del piede dell’avanduna e una perdita volumetrica stimata in 1,3 m3/m/anno (1968-88, da fontolan, 2004) sui fondali marini antistanti. numerosi sono i lavori sedimentologici eseguiti sui fondali antistanti il delta (brambati, venzo, 1967; catani et al., 1978; brambati et al., 1979; brambati et al., 1982; brambati, 1987). in estrema sintesi, i sedimenti che contraddistinguono questo tratto di litorale sono costituiti da sabbie medio fini, unimodali e ben classate dalla battigia fino alla profondità di 2-3 m e da depositi bimodali e moderatamente classati, costituiti da sabbie fini variamente mescolate a peliti, oltre questa profondità. quest’ultime diventano preponderanti al largo della foce e sui fondali oltre i 7 m. la dinamica del trasporto delle sabbie avviene per sospensione gradata (seguendo passega, 1964) e per saltazione secondo le metodiche di vischer (1969): quella delle peliti per sospensione più o meno uniforme. la dispersione dei contributi terrigeni fluviali avviene in modo diverso a seconda della granulometria: il pattern dei sedimenti sabbiosi più grossi evidenzia una movimentazione in un’area ristretta, disposta simmetricamente alla foce (con una maggiore tendenza verso ovest), mentre quello dei sedimenti più fini palesa una dispersione a distanze maggiori approssimativamente dalle batimetri48 che 6-7 in poi. risulta infine interessante osservare che, sempre secondo gli autori precedenti, il trasporto della frazione fine avviene in modo predominante al largo della isobata 7 m e comunque da est a ovest. geologicamente i depositi fronte mare rappresentano la tipica sedimentazione dei prismi costieri di h.s.t (highstend system tract) che testimoniano il massimo livello del mare raggiunto durante l’ultima trasgressione marina (marocco, 1991; gordini et al. 2002). l’intera area deltizia è stata oggetto, sin dagli anni ’60, di una intensa antropizzazione a fine urbanistico residenziale. le abitazioni sono sviluppate soprattutto a nastro nelle strette vicinanze delle spiagge e hanno comportato lo sbancamento dei r i l ievi dunari. l’impetuoso sviluppo urbano ha comportato anche l’insediamento di importanti poli nautici che hanno trovato luogo nelle strette vicinanze delle bocche lagunari (di lignano ad est) e di porto baseleghe (ad ovest). anche l’asta terminale del tagliamento è stata recentemente fissata dalla creazione di una marina che utilizza l’entrata del fiume come canale d’accesso. da una stima preliminare, risulta che gli attuali posti barca direttamente collegati all’attività turistica del delta (parte veneta e parte friulana) siano superiori a circa 5.000. non va inoltre dimenticato che all’interno d’ogni marina sono ospitati: cantieri nautici, officine, aree residenziali, spazi ricreativi, impianti sportivi, campi da tennis, piscine, bar e ristoranti, con un conseguente elevato impatto ambientale. in riferimento al grado di antropizzazione del litorale, in particolare durante la stagione estiva (maggiosettembre) i dati delle aziende turistiche di lignano e bibione, denunciano un’affluenza che da un calcolo approssimativo si aggira complessivamente sulle 8 milioni di presenze. in questo periodo le spiagge risultano quasi completamente occupate da circa 60.000 lettini, 31.000 ombrelloni che vengono tolti in periodo invernale per far posto a staccionate a difesa dalla deflazione eolica. 3. metodologia applicata alla definizione della spiaggia emersa, intertidale e sottomarina e processing dei dati batimetrici. sui 18 km circa di litorale che si estende sulle ali del delta sono stati eseguiti 66 profili topo batimetrici (fig. 1), con spaziatura di circa 150 200 m in corrispondenza della foce, mentre mediamente compresi tra 250 350 m nelle rimanenti aree. i profili sono stati ripetuti durante condizioni deposizionali ed erosive differenti, nello specifico, nei mesi di settembre ed ottobre 2002 e maggio e giugno 2003, al fine di evidenziare eventuali modificazioni su scala stagionale. la morfologia della spiaggia emersa e della porzione di spiaggia e. gordini, r. marocco & r. ramella fig. 1 delta del f. tagliamento: ubicazione dei profili batimetrici, dei capisaldi di riferimento e zonazione dei tratti di spiaggia intertidale e sottomarina. tagliamento river delta: location of the bathymetric profiles, fiducial points and zoning of the inter-tidal and submerged beach. 49 intertidale non coperta dai rilievi batimetrici è stata determinata con metodologia lidar1. contemporaneamente è stato eseguito anche un rilievo fotogrammetrico, condotto con camera–digitale semimetrica. la posizione planimetrica dei transetti batimetrici è stata ottenuta con dgps cinematico, in modalità continua. la strumentazione installata a bordo dell’imbarcazione è stata la seguente: • un ricevitore ashtech g12 lite dotato di decodificatore dgps landstar mkiv della thales tracs ltd per la correzione differenziale in tempo reale; • un plotter ed ecoscandaglio di navigazione lowrance lcx – 18c a doppia frequenza 200/50 khz dotato di cartografia elettronica dell’alto adriatico e funzione di registrazione e visualizzazione grafica dei profili; • un ricetrasmettitore cb 40 canali; • un computer portatile compaq presario 1200 con il compito di gestire l’acquisizione simultanea dei dati di profondità e di posizione forniti, rispettivamente, dall’ecoscandaglio e dal gps/dgps con una frequenza di un secondo. l’indagine è stata eseguita in condizioni di mare calmo, assenza di vento, con marea quasi sempre prossima alla quadratura. la velocità dell’imbarcazione è stata mantenuta costante (3,5 e 4,5 nodi). agli ecogrammi del fondo marino sono state apportate, in fase di elaborazione (postprocessing), le seguenti correzioni (fig.2): 1. il valore di offset del sensore dell’ecoscandaglio rispetto al pescaggio dell’imbarcazione; 2. taratura dello strumento per valutare le variazioni chimico fisiche della colonna d’acqua; 3. stima delle variazioni di immersione del trasduttore a seconda delle diverse velocità di navigazione; 4. ortogonalità dell’impulso acustico inviato dal trasduttore dell’ecoscandaglio rispetto il fondale marino; 5. escursione di marea astronomica-meteorica; 6. filtraggio di variazioni accidentali verticali dell’imbarcazione (onde provocate da altre imbarcazioni, ecc.). da verifiche eseguite in campo risulta che l’errore medio del rilievo batimetrico si aggira attorno ai +/7 cm. le variazioni volumetriche riscontrate dalla ripetizione dei profili in periodo invernale ed estivo sono state definite utilizzando il software matlab 6.5.1 della mathworks. il software ha permesso di passare dai due dem (digital elevation model) dei due rilievi ogs 2002 e 2003, ad una griglia a maglia quadrata che ha consentito per interpolazione lineare, il calcolo delle perdite o acquisti volumetrici dei fondali. 4. batimetria e caratteri morfologici della spiaggia i dati batimetrici sono stati processati con programma surfer version 8.0 surface mapping system della golden software, inc. le figg. 3 e 4 fotografano l’assetto bati morfologico del fondale della spiaggia intertidale e sottomarina nel maggio-giugno 2003. nella carta morfo batimetrica di fig. 4, sono ben visibili le morfologie positive (barre, dune, ecc…) del fondo marino, quelle negative (truogoli, incisioni, ecc…), a testimonianza della specifica dinamica del moto ondoso, dei flussi fluviali e delle correnti mareali lungo i delta inlet. 4.1 zonazione del litorale del delta del f. tagliamento sulla base dei risultati conseguiti è possibile eseguire una zonazione delle spiagge del delta a partire dall’area centrale ed interna alla foce del tagliamento (tratto d di fig.1). dinamica morfologica del litorale ... 1 il sistema lidar utilizzato è l’altm3033 di proprietà della helica s.r.l. e costituito da un laser operante nell’infrarosso (λ=1063 nm) che invia impulsi di luce alla frequenza di 33 khz. il sistema è stato montato solidale all’elicottero as350b2 a sua volta dotato di una piattaforma inerziale, che dispone di compensazione per le variazioni di assetto dell’aeromobile in rollio e beccheggio oltre al posizionamento dgps. l’indagine ha permesso di ottenere una densità media di punti al suolo superiore a 1,5 punti al m2. la camera digitale utilizzata per il rilievo fotogrammetrico è del tipo semimetrica rollei modello 6008 con dorso digitale phaseone modello h20. il sistema di acquisizione digitale ha una spaziatura di pixel di 9 micrometri ed è composta da 4080 x 4076 pixel con una dinamica di 48 bit. fig. 2 diagramma a blocchi del postprocessing applicato alle registrazioni del fondo marino. flow diagram of the post-processing sequence applied to the sea floor records. 50 e. gordini, r. marocco & r. ramella fi g. 3 c ar ta b at im et ric a d el la s p ia gg ia in te rt id al e e so tt om ar in a d el d el ta d el f . t ag lia m en to . r ili ev i o g s 2 00 3. b at hy m et ric m ap o f t he in te rtid al a nd s ub m er ge d b ea ch o f t he t ag lia m en to r iv er d el ta . 2 00 3 o g s s ur ve ys . 51dinamica morfologica del litorale ... fi g. 4 s ch em a m or fo d in am ic ose d im en ta rio d el d el ta d el f . t ag lia m en to e d el s uo li to ra le . m or p ho -d yn am ic a nd s ed im en ta ry s ke tc h of t he t ag lia m en to r iv er d el ta a nd o f i ts li tt or al a re a. la foce del f. tagliamento tratto d l’asta terminale del fiume, dopo un percorso meandriforme, si sviluppa su un breve tratto rettilineo (ampiezza di 150 m e profondità di 6 m circa) dove si è insediata la darsena “marina uno” e continua fino a mare, con sezione d’alveo molto simmetrica e classica barra di foce. sul tratto centrale dell’alveo sono presenti campi di dune subacquee (sensu, ashley et al., 1990; fontolan et al., 2000) a profilo asimmetrico, sviluppate secondo il flusso uscente, che divengono simmetriche verso lo sbocco a mare; qui, la piana sommersa viene definita da una vasta area semicircolare, a debole pendenza (da 1,0 a 1,7 ‰) incisa dal canale di foce, in parte naturale e in parte scavato artificialmente per rendere accessibile l’ingresso al porto fluviale. il passaggio tra la porzione interna ed esterna della foce, è contraddistinto dalla presenza di uno sviluppato ebb-tidal delta, che si concretizza con un imponente water flow ramp che dalla profondità di 6,0 m (darsena “marina uno”) passa, ad una distanza di circa 1,3 km (verso mare), ad una profondità di 1,0 m. il fronte deltizio s’identifica con il fitto ravvicinamento delle isobate comprese tra 1,0 e 6,0 m che determina un gradino morfologico ad elevata acclività (massimo 1,3 %). questo gradino rappresenta il limite estremo delle gittate solide più grosse del tagliamento, e dunque, i più recenti depositi riconducibili al sistema hst. nel dettaglio (fig. 3 e fig 5; transetto l01lignano e b03-bibione) la piana sommersa viene contrassegnata dalla presenza di numerose bedforms, che vanno dalle canalizzazioni marginali (1,2 m), solo in parte naturali che si sviluppano al piede delle barriere frangiflutto del faro di punta tagliamento, alle barre allungare e uncinate (altezza di circa 0,2-0,5 m) oltre a numerose barre di swash lunate, alternate ad altre più irregolari (altezza 0,4-0,6 m), in continua evoluzione e trasformazione operata dal moto ondoso. queste ultime morfologie attive, conferiscono al delta una componente wave-dominated (sensu, hayes, 1980) che palesa la ridistribuzione degli apporti da parte del moto ondoso. il canale principale è bordato da barre lineari di margine (altezza variabile da 0,5 a 0,8 m) che manifestano un maggiore sviluppo al lato occidentale. l’alveo della foce è soggetto a periodiche escavazioni per assicurare l’accesso al porto “marina uno. ad esempio, nel maggio 2003 ingenti quantità di sabbia sono state prelevate al letto del canale navigabile e depositate immediatamente ad ovest dell’area di scavo. ciò ha comportato una modificazione della forma e dell’estensione del fronte deltizio e, nel dettaglio, ha innescato un riequilibrio del canale e la trasformazione della barra lineare di margine. procedendo da ovest verso est, la linea di costa assume un andamento sinuoso, caratterizzato dal naturale protendimento fociale “sostenuto”, anche, da un lungo pennello di sbarramento, realizzato nel 1963 (fig. 5; transetto l01-lignano) e, accorciato, recentemente, per favorire il by-passing dei sedimenti e la loro naturale dispersione verso est. la spiaggia emersa, completamente livellata nel periodo balneare-estivo, assume un’estensione di circa 100 m ed è delimitata, verso terra, da apparati dunari a forma di barcana con al fronte accumuli eolici minori che vengono zappati dalle mareggiate invernali; quella intertidale, risulta leggermente più estesa (ca. 120 m) con un ampio terrazzo di bassa marea (tra 1,0 e 1,5 m), con barre di swash (sensu, king c.a.m., 1972; ashley et al., 1990), e campi di barre di accrescimento con orientazione sud-ovest (fig. 5; transetto l01-lignano). la spiaggia sottomarina è contraddistinta da un brusco restringimento delle isobate poste a circa 1 km dalla foce e da una loro inflessione verso riva. segnatamente, dopo la zona sub-orizzontale sostenuta dall’opera di difesa, segue una forte acclività del fondale (passaggio dalla isobata 1,0 a quella 6,0 m in 325 m circa) su cui si insediano forme di fondo attive (barre e cordoni sottomarini), determinate dall’interazione dell’energia di trasporto fluviale con quella litorale. va sottolineato che il corpo sedimentario di questo prisma deltizio rappresenta un notevole serbatoio di materiale sabbioso, eventualmente sfruttabile per mirate operazioni di riequilibrio del litorale circostante. dopo il piede del fronte deltizio il fondale declina dolcemente con valori (ca. 2,0 ‰) che rispecchiano le pendenze dei fondali limitrofi e sono caratterizzati dalla sedimentazione di materiali fini. al lato opposto, la sponda occidentale della foce del tagliamento, oggetto in questi anni di un rapido arretramento, è stata progressivamente difesa con importanti opere marittime a mare (scogliere) e al piede delle dune (fascinate verticali, graticciate, tubi tipo longard riempiti di sabbia) che hanno trasformato radicalmente l’aspetto paesaggistico del paraggio e l’idrodinamica litorale. tutte queste opere, comunque, non hanno evitato il perdurare dei processi erosivi che esplicano la loro massima concentrazione nel tratto interno alla foce ed immediatamente ad ovest del faro di punta tagliamento. il litorale è formato da una spiaggia piatta e di modesta estensione, contraddistinta da mini tomboli collegati ai frangiflutti. nelle aree non protette si registra una repentina regressione della battigia che ha portato ad una ulteriore diminuzione della spiaggia (< di 50 m) che ora viene delimitata verso terra dalle lame tra i vecchi cordoni dunari (lama di rivelino). la spiaggia intertidale e sottomarina mostrano, nell’insieme, l’assenza o quasi del terrazzo di bassa marea e un minimo sviluppo della zona dinamica a barre e truogoli. qui la transizione dalla battigia alla spiaggia esterna avviene con un’elevata acclività, indice questo, di una profonda instabilità. al piede delle scogliere, la spiaggia sommersa è incisa da una depressione (ampia circa 100 m e profonda 1,2 1,5 m), probabilmente determinata, in analogia con situazioni analoghe personalmente riscontrate, in parte da fenomeni di riflessione del moto ondoso (fig. 5; transetto b03-bibione) e in parte, anche dalle correnti di fondo dei flussi marginali del fiume. segue verso mare, una seconda ampia piana sub-orizzontale (da 0,5-1,0 m), dove sono evidenti in posizione arretrata barre intertidali seguite da cordoni sottomarini e complessi sistemi di barre di swash, complessivamente fino a 600-800 m dalla costa. dal piede della barra più esterna, si passa quindi con un brusco cambiamento di pendenza ad un fondale sub-pianeggiante: in particolare, la base della fascia degradante verso le profondità maggiori, si colloca ad una distanza pari circa 1000 m (corrispondente a 5,0/6,0 m di profondità) con un valore medio di pendenza di 15,4 ‰ (confrontabile con quello riscontrato sull’analogo settore dell’area friulana). dalla profondità di 6,0 m fino al limite dell’area indagata (circa 3000 m dalla battigia, 11,0 m), il fondale 52 e. gordini, r. marocco & r. ramella 53dinamica morfologica del litorale ... fig. 5 alcuni esempi significativi di profili topobatimetrici riguardanti le spiagge del delta del f. tagliamento. per l’ubicazione dei profili si rimanda alla fig. 1. le quote, in metri, sono riferite al livello medio mare (l.m.m.), mentre, le progressive, sempre espresse in metri, sono riferite ai capisaldi istituiti lungo il litorale. some meaningful examples of topographic and bathymetric profiles acquired in correspondence to the beaches of the tagliamento river delta. see fig. 1 for the profiles location. the elevation expressed in meters, are referred to the medium sea level (l.m.m), whereas the distances (in meters) are referred to the fiducial points located along the coast. marino presenta andamento pressoché tabulare con minima inclinazione. litorale orientale (dalla foce del tagliamento alla bocca di lignano) tratto c alla zona prettamente di foce segue verso est, senza soluzione di continuità, una linea di riva ad andamento prevalentemente concavo, disarticolato dalla presenza di numerosi pennelli trasversali che interrompono con i classici denti di sega il suo sviluppo lineare. l’accumulo delle sabbie sul lato occidentale dei pennelli rende palese la prevalenza del trasporto lungo riva da ovest verso est. la minor influenza del trasporto regionale in senso opposto (da est verso ovest), sembra essere legata al forte sviluppo dell’ebb-tidal delta della bocca lagunare di lignano, che trattiene gran parte dei depositi e in parte flette il movimento dei sedimenti verso il largo. il bilancio sedimentario totale, comunque, rende palese che gli arrivi di sabbie da ovest non compensano adeguatamente le perdite per erosione ormai croniche di questo tratto di costa. anche la limitata estensione della spiaggia (ca. 50 m, ampiezza tra le minime dell’intero paraggio), evidenzia i regimi erosivi tuttora in atto e l’inefficacia delle opere di difesa. la spiaggia emersa è delimitata al retro da opere longitudinali aderenti per impedire l’erosione delle aree urbanizzate retrostanti, ma che possono determinare pericolose superfici riflettenti dell’onda di mareggiata. il settore di litorale manifesta una zona sub-orizzontale molto limitata (10-15 m circa) o quasi del tutto assente e ravvivata da una unica barra intertidale (talvolta assente), seguita verso mare da un truogolo che si posiziona grossomodo a breve distanza dalla testa dei pennelli (fig. 5; transetto l07-lignano). più ad oriente, il fianco orientale del conoide deltizio si inflette verso costa, determinando un rapido approfondimento del fondale anche a limitata distanza dalla battigia e in particolar modo nell’area antistante le opere di difesa. la zona a barre e truogoli presenta un’estensione di circa 140 -160 m, una o al massimo due, barre sottomarine che si sviluppano su un’area a pendenza variabile da 12,7 a 16,3 ‰ (fig. 5; transetto l15-lignano). dopo la zona dinamica, il fondale presenta tre caratteristiche fasce a diversa pendenza: la prima, della barra sottomarina più esterna (ca. 200 m dalla battigia, 3,0 m), fino a circa 500 m dalla battigia (-4,5 m), con un’acclività prossima a 4,2 ‰, una seconda, tra 500 e 900 m circa dalla riva (rispettivamente 4,5 e 5,9 m di profondità) con un’acclività superiore alla fascia precedente (7,3 ‰) e, infine, la terza fascia che si colloca ad una distanza compresa tra 900 e 1900 m circa (corrispondenti a 7,0/8,0 e 10/11 m di profondità), con un valore di pendenza minore (1,6 ‰) rispetto al tratto precedente e simile a quelli osservati al largo della fascia prodeltizia. tratto b da lignano riviera a sabbiadoro la riva assume uno sviluppo convesso, con un’ampia spiaggia emersa (180 m) che passa ad una estesa piana di bassa marea (ca. 40-60 m) e intertidale sottomarina (340 m). e’ un tratto di spiaggia sostanzialmente in accrescimento con alle spalle (zona centrale), una duna litorale (4 a 5 m circa d’altezza), e nei tratti limitrofi opere di difesa aderenti in calcestruzzo. la spiaggia sottomarina manifesta una zona dinamica ampia 250 m, con due ordini di barre sottomarine e un’acclività di 9,0 ‰ circa. in questo tratto di litorale s’individuano cinque zone sottomarine a diversa acclività. nella presente situazione, però, i valori di pendenza sono nettamente inferiori a quelli visti precedentemente e danno al profilo della spiaggia un andamento più regolare, dove i cambiamenti di pendenza risultano meno accentuati (fig. 5; transetto l15-lignano). proseguendo verso la bocca di lignano (fig. 5; transetto l20-lignano) la spiaggia sottomarina fa risaltare un ulteriore addolcimento del fondale: in corrispondenza della convessità della linea di riva, la fascia a barre e truogoli raggiunge la massima estensione del paraggio (ca. 320 m), mediamente con due o tre ordini di barre ed eccezionalmente quattro. i profili tipici della spiaggia sottomarina di questa zona palesano tre intervalli, ad andamento regolare, con la presenza di fanerogame marine (cymodocea), che aumentano in ampiezza, e dunque diminuiscono gradualmente la loro acclività avvicinansi alla bocca (vedi fig. 5; transetto l20-lignano). segnatamente, le fanerogame si posizionano in una limitata area, a cavallo delle batimetriche 4,0/6,0, a largo della fascia costiera di lignano sabbiadoro, sulla rampa morfologica che porta al fondale più profondo. tratto a in prossimità del canale di accesso a lignano, la linea di riva è condizionata da una serie di interventi antropici (pennelli impermeabili ed opere di difesa aderenti) realizzati a salvaguardia dell’area urbanizzata retrostante e del suo ambito portuale. la spiaggia emersa risulta poco estesa (ca. 60 m) e fortemente antropizzata (anche con una serie di opere semifisse) per far fronte alla stagione turistica; verso mare è presente un terrazzo di bassa marea (come nel litorale precedente), ampio mediamente 40 m e fissato dall’aggetto dei pennelli. dopo questa distanza e con una forte pendenza inizia la zona a barre e truogoli. anche all’ interno della bocca lagunare il terrazzo di bassa marea (che si sviluppa tra le profondità di 0,5 e 1,0 m) trova la sua massima estensione, fino a delimitare il canale principale del delta inlet (fig. 5; transetto l27-lignano). nello specifico, il delta inlet di lignano (figg, 3 e 4) definisce un corpo sedimentario complesso che si protende di molto verso mare e che viene sostenuto da un canale principale. questo termina, dopo un andamento quasi rettilineo, con uno sbocco verso sudovest, allineandosi alla prevalente direzione delle bocche lagunari e delle foci dell’alto adriatico. il canale si approfondisce progressivamente verso mare, raggiungendo la profondità massima di 11,0 m e segue un andamento sinuoso con una prima deviazione verso oriente, con conseguente erosione della sponda, difesa da una scogliera in pietra a pezzatura grossolana. qui l’alveo assume una classica geometria asimmetrica con al centro un esteso campo di dune subacquee (di modeste dimensioni, h = 0,8 m e l = 20 m), disposte marginalmente rispetto alla direttrice principale di flusso. proseguendo verso il largo, il canale mostra un’ulteriore deviazione verso sud, sud-ovest con conseguente deflessione dei sedimenti sabbiosi verso le profondità maggiori e alla creazione di cordoni sottomarini 54 e. gordini, r. marocco & r. ramella marginali, con la barra longitudinale occidentale di minor sviluppo rispetto all’opposta. nel complesso, l’assetto della bocca lagunare, rimarca l’evidente progradazione verso mare e quindi la prevalenza della componente di riflusso rispetto a quella di flusso, con una componente longitudinale (da est ad ovest) resa palese dalla presenza di uncinature, forme lobate, propaggini sabbiose e forme lobate allungate. al lato orientale del canale (dalla battigia fino a 2,5 m), si sviluppa una vasta area a swash bars, con forme lunate alternate ad irregolari, continuamente rielaborate dal moto ondoso. anche il delta inlet della bocca di lignano e soprattutto gli accumuli laterali del canale principale, possono fornire materiale passibile di un utilizzo per il rifornimento artificiale delle spiagge dopo gli opportuni accertamenti sulla qualità dei depositi sanciti per legge. litorale occidentale (dalla foce del tagliamento a punta baseleghe) tratto e proseguendo più ad ovest la spiaggia emersa palesa la situazione evidenziata precedentemente (tratto d) con una sottile lingua sabbiosa (50 -100 m), delimita alle spalle dalla laguna-stagno costiero di revelino che comunica con il mare con una rotta di limitate dimensioni e profondità (20-40 m e -0,5 /-1,0 m, vedi fig. 5; transetti b08-bibione e b12-bibione). recentemente, anche in questa zona sono stati realizzati in situazione d’emergenza tre rubble-mound groins al fine di contrastare il processo d’arretramento in atto. l’erosione, verificatasi sopraflutto al pennello occidentale, fa ritenere che il loro dimensionamento (spaziatura e aggetto) non sia in grado di tamponare la situazione vigente. il carattere erosivo della spiaggia viene anche visualizzato dalla limitata estensione del terrazzo di bassa marea mostra (20-30 m) e un approfondimento costante del tratto intertidale della spiaggia fino al limite della zona a barre e truogoli (posta a 0,9 m di profondità e a 40/45 m dalla battigia). più al largo, il fondale è caratterizzato da una minima fascia dinamica (circa 100-150 m), sostenuta da una sola barra che talvolta risulta appena accennata o assente con un unico truogolo molto accentuato. ancora più al largo il fondale marino può essere suddiviso in tre profili tipici, corrispondenti a fasce di diversa acclività del conoide deltizio; • una prima fascia mossa da depressioni (da 130 m a cavallo dei 3,0 m di profondità, a circa 190 m dalla linea di riva) e zone in accumulo più estese (circa 400 m). il passaggio fra le due aree avviene con un gradino morfologico mediamente accentuato (5,9 ‰); • una seconda fascia, molto estesa (1600 m circa), prevalentemente sub-orizzontale; • un tratto finale, molto acclive che non trova riscontro nell’ala sinistra del delta. tratto f in questo settore del litorale si registra un graduale cambiamento del profilo di spiaggia sottomarina, con la comparsa di una zona sub-orizzontale interna, cui fa seguito la zona a barre e truogoli che si allarga progressivamente procedendo verso punta baseleghe (fig. 5; transetto b16-bibione). tale allargamento della zona dinamica è ben visibile in corrispondenza del piazzale zenith, dove raggiunge un’ampiezza di circa 250 m e comprende due ordini di barre e altrettanti truogoli, ad andamento irregolare. nello stesso profilo, dopo la zona dinamica, si riconosce una fascia ad andamento regolare con acclività media pari a 3,6 ‰. ancora più ad ovest la fascia a barre e truogoli si amplia ulteriormente, arrivando ad un’estensione massima di 250-340 m con 2-3 ordini di barre sottomarine. estremamente significativo risulta l’andamento delle isobate nel fondale prospiciente la zona piazzale zenith, tra i 3,0 e i 6,0 m di profondità che circoscrivono un’area in accumulo, derivante dall’erosione del tratto di spiaggia più orientale (fig. 4). in controtendenza rispetto alle aree sopra descritte, la parte centrale della costa di bibione mostra un’accentuata convessità verso mare. il confronto delle linee di riva della ctr del veneto (1999) e quella dei nostri rilievi (fig. 3) evidenzia una tendenza alla progressione naturale di questo tratto di litorale con valori di avanzamento della spiaggia emersa, pari a circa 10 m. l’arenile qui raggiunge il massimo valore (200-250 m) e mostra una pendenza regolare, senza rotture determinate da morfologie naturali (berma ordinaria e di tempesta) e viene delimitato da opere di difesa longitudinali aderenti che insistono in un’area depressa che si sviluppa fino al suo limite settentrionale. il terrazzo di bassa marea è molto esteso (60 m circa) e degrada dolcemente verso la fascia dinamica del litorale che è anch’essa abbastanza ampia (complessivamente 70-80 m). segue un fondale molto omogeneo (fig. 5; transetto b16-bibione) con una graduale diminuzione della pendenza passando dalla zona a barre e truogoli (7,6 ‰), a quella immediatamente seguente (5,4 ‰); tendenza questa, che viene confermata anche verso mare, dove dopo un modesto gradino morfologico (6,8 ‰), la spiaggia sottomarina mostra un assetto quasi sub-orizzontale con acclività pari a 2,8 ‰ (3,0 ‰ a circa 3 km dalla costa). tratto g proseguendo verso la bocca di baseleghe la spiaggia si assottiglia (ampiezza circa 50-70 m), senza però evidenziare processi erosivi in atto (fig. 5; transetto b24-bibione). il confronto dei rilievi 1999 con quelli 2003, confermano tuttavia la tendenza alla stabilità del litorale. la sua parte intertidale ha un’estensione di circa 70 m, con un evidente terrazzo di bassa marea delimitato da una barra (posta ad una profondità di – 0,7 m). tratto h in coincidenza con la freccia litorale che delimita la laguna di baseleghe (fig. 5; transetto b29-bibione) si assiste nuovamente ad un ampliamento della spiaggia emersa (circa 150 m) e alla presenza di apparati dunari di modesta elevazione (1-2 m) che si sviluppano parallelamente alla linea di riva dove sono presenti le classiche morfologie di accrescimento di una freccia litorale. la battigia si raccorda dolcemente al terrazzo di bassa marea (ampio 25 m circa) che a sua volta si congiunge dolcemente alla zona dinamica. in questa area tra le isobate 0,5 e 1,5 si riconoscono le tipiche morfologie legate al moto ondoso (piattaforma di spit, sensu, ashley et al., 1990, barre di swash e forme lobate) disposte parallelamente, con spiccata espansione verso ovest, tanto da occludere o trascinare sempre 55dinamica morfologica del litorale ... nella medesima direzione la bocca di baseleghe. questo processo al prolungamento verso occidente dell’ala destra del delta tilaventino e all’occlusione della bocca di baseleghe è ormai noto da molto tempo (zunica, 1971; catani et al., 1978; catani et al., 1982) e viene contrastato oggi, come in passato, attraverso la periodica escavazione del canale d’accesso al porto. si fa presente che anche queste escavazioni possono fornire ingenti quantità di materiale per il ripascimento delle aree in erosione. la spiaggia sommersa prossima a punta baseleghe mostra un carattere relativamente stabile. la sua parte verso terra è contraddistinta da un’estesa zona dinamica (250-270 m), alimentata da due ordini di barre litorali seguite dai rispettivi truogoli. si passa, poi, quasi senza soluzione di continuità, ad un fondale prevalentemente pianeggiante, caratterizzato essenzialmente da due fasce a modesta pendenza. la prima di queste fasce si estende dalla progressiva 280 m a 1100 m dalla battigia, tra le profondità da 2 a 7 m e con una pendenza di 5,5 ‰. la seconda, con acclività pari a 2,6 ‰, si sviluppa da 1280 a 3000 m dalla battigia, tra le profondità rispettivamente di 7 e 12 m (fig. 5; transetto b29-bibione). il protendimento verso mare del delta inlet è sottolineato in modo particolare dall’andamento delle isobate da 1,5 a 2,5 m che si collocano in posizione avanzata rispetto alle aree adiacenti. il passaggio alle profondità maggiori avviene con una superficie ad acclività pari a 6,3 ‰, che dalla progressiva 1300 m passa gradualmente verso mare ad un valore di 3,6 ‰. anche queste parti più esterne del profilo di spiaggia non presentano morfologie particolari, mantenendo la solita superficie debolmente inclinata che si raccorda ai fondali del golfo di venezia. rispetto al delta inlet opposto (bocca di lignano) quello di baseleghe è meno sviluppato (sia verso terra che verso mare) a dimostrazione che i flussi di marea qui sono meno forti e, soprattutto che nel versante a mare, l’azione della dispersione marina è di molto superiore a quella determinata dai flussi di marea. 5. analisi morfologica quantitativa della spiaggia a completamento di questo studio è stata condotta una breve indagine morfologica quantitativa (sensu, carobene, brambati, 1975; carobene, 1978) al fine di definire l’estensione, le quote e le pendenze e gli elementi morfologici peculiari delle diverse porzioni della spiaggia emersa, intertidale e sottomarina. la finalità dell’analisi è stata quella di identificare su base morfologica le condizioni di stabilità o instabilità del litorale e ciò anche per individuale il dimensionamento ideale del profilo di spiaggia nei diversi settori del paraggio. segnatamente è stata indagata in maniera particolare la zona che si estende dalla battigia alla “zona a barre e truogoli”, che già in altre ricerche si è dimostrata il termometro della situazione erosiva o di accrescimento del litorale (vedi catani et al., 1982). a tal fine, si è appurato che i risultati migliori si ottengono dall’analisi delle relazioni che legano la distanza tra linea di battigia e il piede della barra sottomarina esterna (lb-p) e la sua pendenza α (fig. 6). si è accertato anche, com’era del tutto prevedibile, che sussistono relazioni di dipendenza tra ampiezza della zona sottomarina (spiaggia intertidale + zona a barre e truogoli), la sua pendenza e le condizioni d’erosione o stabilità del litorale definite attraverso osservazioni dirette e validate dal confronto con dati pregressi. infatti, i punti che rappresentano questi parametri morfologici, calcolati per ogni sezione topo batimetrica (sono stati utilizzati esclusivamente, anche per omogeneità, i soli dati desunti dall’ultimo rilievo, maggio-giugno 2003) mostrano una regressione lineare d’equazione y = 0,0022 x + 1,1489 e r2 = 0,7386. in altri termini la pendenza della spiaggia, in condizioni d’omogeneità tessiturale dei sedimenti, è in relazione con la sua stabilità e permette di eseguire una zonizzazione delle aree in erosione da un lato e di quelle in progressione o in stabilità al lato opposto. alla maggiore acclività e minore estensione della zona a 56 e. gordini, r. marocco & r. ramella fig. 6 diagramma “distanza tra linea di battigia e piede della barra sottomarina esterna (lb-p) e la pendenza della retta lb-p (α). diagram “distance between the foreshore and the foot of the submerged external bar (lb-p) and the dip of the line lb-p (alfa.) barre e truogoli, corrisponde una concentrazione di punti (raggruppamento r1); viceversa in condizioni opposte (r2). tra questi due raggruppamenti o famiglie di tratti di litorale si colloca poi, una fascia intermedia di transizione graduale tra le due. all’interno del raggruppamento r1 si ubicano: • i tratti di spiaggia ad ovest delle opere marittime di difesa costruite in prossimità del faro di punta tagliamento (transetti b5; b6; b7; b8 e b9). come precedentemente osservato quest’area manifesta evidenti processi d’ erosione trascorsi ed in atto, che hanno portato ad un notevole assottigliamento della spiaggia emersa, con la presenza di rotte e varchi; • i tratti di spiaggia ad est della foce del tagliamento (lignano riviera), difesi da opere trasversali, eseguite negli anni 1966-1979, e soggetti tutt’oggi ad evidenti processi erosivi ( l4; l5; l6; l7; l8; l9 e l10) . • le strette spiagge del margine occidentale della bocca di lignano, anch’esse caratterizzate dalla presenza di opere di difesa impermeabili ( l27; l28 e l29). nell’ambito del raggruppamento r2: • si ubicano i rimanenti tratti del litorale ad eccezione di quelli di raccordo dell’area del faro e di bibione (transetti b 10, b 11 e b 12), e tra lignano riviera e sabbiadoro (l11). questa famiglia di punti raggruppa le aree di litorale dove sia in base ad osservazioni dirette (particolari morfologie osservate sulla spiaggia emersa ed intertidale), sia in base a confronti cartografici recenti (sovrapposizione della linea di costa definita dalle carte tecniche regionali delle regioni veneto e friuli venezia giulia, 1999 -1990 e quella dei presenti rilievi di maggio-giugno 2003) presentavano caratteri di stabilità o tendenza alla progressione naturale. se da un lato la distinzione tra le due famiglie che raggruppano tratti di litorale deltizio ai limiti del diagramma sono evidenti, dall’altro bisogna specificare che non tutti i punti che cadono nell’area di stabilità o progressione si trovano sotto una condizione acclarata. quest’ultimo fatto sembra essere spiegato come la tendenza di queste aree in lieve erosione a portarsi verso una relativa stabilità, oppure, all’inverso dalla condizione di stabilità relativa verso una condizione di erosione tendenziale (es. punti relativi ai transetti l12 e l3 o nel caso del litorale di bibione, b13 e b14). anche se permangono queste incertezze sull’interpretazione di un numero ristretto di dati, si può ritenere che nell’insieme il diagramma fornisce un ottimo strumento per discriminare aree tendenzialmente in erosione, da quelle stabili o in progressione naturale. altri parametri morfologici quantitativi delle spiagge forniscono informazioni analoghe, ma questo permette di definire con una certa precisione la pendenza e la distanza che le spiagge devono raggiungere in condizioni d’equilibrio con gli agenti meteomarini. 6. variazioni batimetriche e volumetriche del fondale marino dal ciclo erosivo invernale a quello deposizionale estivo nell’arco annuale scandito dal periodo invernale (settembre ed ottobre 2002) a quell’estivo (maggio e giugno 2003), sui 18 km circa di litorale si sono definiti i principali spostamenti del materasso sabbioso. i bilanci volumetrici eseguiti per ogni transetto sono riportati nelle tabelle i e ii. preme sottolineare che l’errore stimato sul valore di profondità rilevato (+/-7 cm), può portare a sovrastimare o sottostimare i volumi calcolati e ciò soprattutto, quando le variazioni di profondità sono minime e si ripercuotono su estese superfici. per questo motivo non si sono prese in considerazione le variazioni con valore eguale o inferiore a questo, anche se calcolate. ne consegue che le variazioni dei fondali che assommano a valori prossimi a +/15-20 m3/m, devono essere considerate solamente indicative di una tendenza del litorale, non variazioni effettive. la ripetizione dei rilievi nei due periodi ha confermato che i principali cambiamenti della spiaggia sottomarina avvengono quasi esclusivamente nella zona dinamica a barre e truogoli, con la traslazione delle barre più al largo dalla posizione estiva, durante la stagione invernale. ma oltre a questa fascia, tipicamente soggetta a variazioni, ne sono emerse altre aree e segnatamente (fig. 7): • una prima ubicata sul fronte deltizio, in cui sono presenti numerose barre e cordoni litorali che si muovono verso ovest, sospinti dalla corrente litoranea e dai mari del i quadrante, mentre subiscono una dispersione diversa, per mari del ii e iii quadrante. in questa zona e soprattutto in prossimità della foce si riscontrano locali approfondimenti dei fondali seguiti da accumuli che tendenzialmente divengono prevalenti. questi fenomeni diventano evidenti in corrispondenza del pennello occidentale di foce (vedi transetti l03 e l04; tab. i), che continua a trattenere nell’area, i contributi solidi del tagliamento, non permettendo l’alimentazione del litorale lignanese; • una seconda area, ad ovest di bibione, localizza ad una distanza compresa tra 800 e 1000 m dalla costa e a profondità variabile da 5,0 a 7,0 m, dove si riscontra una modesta rottura di pendenza (acclività massima pari a 10,5 ‰) che è possibile seguire per circa 2,5 km parallelamente alla costa (ben evidente nei transetti b19; b20; b21; b22 e b23). qui si registra una variazione massima di spessore di circa 0,5 m, ed un deficit sedimentario valutato lungo il transetto in 67,6 m2; • una terza, più ad est, presente sul fondale marino antistante bibione, che si estende da 870 a 980 m dalla costa, a cavallo della batimetrica 6. qui il fondale è relativamente elevato e si presenta fortemente accidentato per avvallamenti e gobbosità a geometria variabile, ben visibili lungo il transetto b11 (ma anche nei transetti dal b07 al b15). tali asperità, distribuite sul margine occidentale dell’alto morfologico (fig. 4), non presentano similitudini (in ampiezza e lunghezza d’onda) con le morfologie tipiche dalla zona a barre e truogoli. ritornando alla zona a barre e truogoli, nell’area veneta essa è maggiormente sviluppata verso ovest (da bocca di baseleghe alla porzione centrale del litorale), mentre perde di estensione e viene quasi completamente sostituita da aree in erosione in prossimità della foce tilaventina. dette aree, disposte parallelamente e/o leggermente inclinate rispetto alla linea di riva, sono particolarmente evidenti in prossimità di pineta punta faro e lame di revelino dove si riscontrano deficit 57dinamica morfologica del litorale ... 58 e. gordini, r. marocco & r. ramella fig. 7 variazione dello spessore dei sedimenti dei fondali risultante dai rilievi ogs 2002-2003. variation of the sediment thickness as resulted from the 2003 ogs surveys. sedimentari compresi tra 0,2 e 0,45 m3/m2. l’asportazione di materiale verso riva, viene tuttavia in buona parte compensata dalla deposizione al largo (0,13 m3/m2). nell’area friulana la zona a barre e truogoli è molto sviluppata in corrispondenza di lignano sabbiadoro e decresce fino alla quasi scomparsa verso lignano riviere e pineta. come è stato già evidenziato precedentemente, la spiaggia di sabbiadoro presenta, a lungo periodo, un carattere stabile tendente a periodi di progressione. tale situazione è confermata anche a breve periodo dal confronto dei rilievi eseguiti e dalla conformazione stessa del fondale marino (terrazzo intertidale, zona a barre e truogoli, fondale sub pianeggiante che si estende fino a 2 km dalla costa, ecc). l’area di bocca lagunare (bocca di lignano), presenta accumuli sotto forma di depositi allungati parallelamente alla direzione di sviluppo del canale principale. sulla base dei rilievi eseguiti non compaiono alcune evidenze macroscopiche di deficit o accumuli sedimentari in prossimità della bocca. queste probabilmente potranno emergere solamente da un’analisi effettuata in più lungo periodo. comportamento diverso, denuncia il tratto di litorale che va da lignano riviera a pineta; qui si osserva la quasi stabilità della zona, eccezion fatta, per le limitate aree d’approfondimento dei fondali (dell’ordine di 0,1÷ 0,2 m e quindi non significative, dati i limiti di accuratezza dei rilievi), poste al piede dei pennelli presenti nell’area. nelle tabelle i e ii oltre ai bilanci volumetrici calcolati dal confronto dei rilievi ogs 2002 e 2003, viene riportata anche la tendenza evolutiva del litorale che emerge dal confronto dell’ultimo rilievo ogs 2003 con quelli del 1997 (litorale di bibione) e della regione friuli venezia giulia (brambati, 1987 spiagge di lignano). in grassetto sono stati messi in evidenza i valori volumetrici che possono essere considerati meno influenzati dagli errori di misura e dunque considerati attendibili per un primo bilancio volumetrico del trasporto litorale. nell’ultima colonna si sono riportati i confronti con le situazioni precedenti. in particolare, dai transetti eseguiti in prossimità della foce, emerge che l’apparato deltizio presenta un consistente incremento volumetrico. questo dato è molto importante poiché questi accumuli possono essere utilizzati (dopo i controlli previsti per legge) per il ripascimento delle spiagge e, nel contempo, per liberare il passo marittimo d’accesso ai porti interni alla foce. si è cercato pertanto di quantificare con la massima precisione possibile e nell’intervallo temporale esaminato, l’ammontare e la relativa stabilità di tale accumulo di sedimento. per eseguire questa stima è stato utilizzato il programma surfer version 8.00 surface mapping system della golden software, inc., colorado. attraverso questo software è stato possibile 59dinamica morfologica del litorale ... tabella i variazioni volumetriche e tendenze evolutive dei fondali del delta del f. tagliamento (ala orientale). volume variations and evolutive trends of tagliamento river delta (eastern sector). transetto deficit deposizione variazione volumetrica tendenza evolutiva risultante dal confronto (m3 / m) dei profili ogs 2003 con quelli da rilievi ogs 2002-2003 brambati (1987) transetto l01 x + 64,3 consistente ripascimento al largo erosione sottocosta transetto l02 x + 24,1 leggera tendenza al ripascimento al largo erosione sottocosta transetto l03 x + 274,7 ripascimento al largo leggera tendenza all’erosione sottocosta transetto l04 x + 197,3 ripascimento al largo leggera tendenza all’erosione sottocosta transetto l05 x + 63,9 stabile leggero ripascimento sottocosta transetto l06 x 9,1 stabile leggero ripascimento sottocosta transetto l07 x + 9,3 stabile leggero ripascimento sottocosta transetto l08 x + 3,3 ripascimento sottocosta stabile con leggera tendenza all’erosione al largo transetto l09 x 39,9 leggero ripascimento sottocosta stabile con tendenza all’erosione al largo transetto l10 x 18,8 stabile transetto l11 x 6,4 stabile al largo leggero ripascimento sottocosta transetto l12 x + 57,6 stabile al largo leggera tendenza all’erosione sottocosta transetto l13 x 7,9 stabile leggera tendenza all’erosione sottocosta transetto l14 x + 17,3 stabile transetto l15 x + 6,6 stabilità transetto l16 x + 27,8 --transetto l17 x + 7,4 --transetto l18 x + 3,1 --transetto l19 x 5,4 --transetto l20 x 1,1 --transetto l21 x + 5,4 ripascimento sottocosta stabilità al largo transetto l22 x + 7,5 --transetto l23 x + 14,1 --transetto l24 x 18,0 --transetto l25 x + 4,9 stabilità sottocosta leggera tendenza al ripascimento al largo transetto l26 x + 11,3 transetto l27 x + 7,9 --transetto l28 x + 229,15 --transetto l29 x 2,9 --transetto l30 x + 5,3 --60 e. gordini, r. marocco & r. ramella e. gordini, r. marocco & r. ramella tabella ii variazioni volumetriche e tendenze evolutive dei fondali del delta del f. tagliamento (ala occidentale). volume variations and evolutive trends of tagliamento river delta (western sector). transetto deficit deposizione variazione volumetrica tendenza evolutiva risultante dal confronto (m3 / m) dei profili ogs 2003 con quelli da rilievi ogs 2002-2003 italrilievi s.n.c (1997) transetto b01 x 74,3 --transetto b02 x + 156,3 -- transetto b03 x + 79,9 --transetto b04 x + 74,3 stabilità al largo ripascimento sottocosta transetto b05 x + 82,8 tendenza al ripascimento transetto b06 x + 100,0 leggera tendenza all’erosione al largo leggera tendenza all’erosione sottoriva transetto b07 x + 44,3 erosione al largo erosione sottocosta transetto b08 x + 11,2 erosione al largo erosione sottocosta transetto b09 x 3,3 erosione al largo erosione sottocosta transetto b10 x + 46,2 erosione al largo erosione sottocosta transetto b11 x 50,0 erosione al largo erosione sottocosta transetto b12 x + 34,6 erosione al largo erosione sottocosta transetto b13 x 48,6 --transetto b14 x 64,7 --transetto b15 x + 0,2 erosione al largo erosione sottocosta transetto b16 x + 13,3 ripascimento sottoriva leggera erosione al largo transetto b17 x 4,3 ripascimento sottoriva stabilità con tendenza al rinascimento al largo transetto b18 x 7,4 ripascimento sottoriva stabilità al largo transetto b19 x + 0,6 ripascimento sottoriva stabilità al largo transetto b20 x 14,9 ripascimento sottoriva stabilità al largo transetto b21 x + 45,4 leggero ripascimento sottoriva stabilità al largo transetto b22 x + 11,0 leggero ripascimento sottoriva stabilità centrale ed erosione al largo transetto b23 x 71,8 ripascimento sottoriva stabilità con tendenza al rinascimento al largo transetto b24 x 18,8 ripascimento sottoriva stabilità con tendenza all’erosione al largo transetto b25 x + 12,3 ripascimento sottoriva stabilità con tendenza all’erosione al largo transetto b26 x + 0,6 ripascimento sottoriva stabilità al largo transetto b27 x + 11,8 ripascimento sottoriva stabilità al largo transetto b28 x + 4,6 ripascimento sottoriva erosione al largo transetto b29 x + 28,4 --transetto b30 x + 22,5 leggero ripascimento sottoriva stabilità centrale ed erosione al largo transetto b31 x + 8,5 ripascimento sottoriva stabilità al largo estrarre i due dem (digital elevation model), inerenti l’area deltizia per i due rilievi batimetrici ogs 2002 e 2003. successivamente, sempre con lo stesso software, sono stati creati con il metodo triangular with linear interpolation, altrettanti grid a maglie quadrate che rappresentano la superficie reale basata sulle informazioni reali disponibili (rilievo eseguito). la differenza fra le due superfici così ottenute ha permesso di raffigurare le variazioni di spessore subita dal litorale (fig. 8). dal confronto emerge che in prossimità della foce, le aree soggette a variazioni dei fondali superiori all’errore stimato sono pari a 5.809.408 m2 con zone in accumulo pari a 4.770.317 m2 e altre in approfondimento pari a 1.039.091 m2. il volume conseguente è risultato essere pari a ca. 570.000 m3 (volume positivo), contro uno di ca. 75.000 m3 (perdite), con un bilancio positivo di ca. 495.000 m3. tenendo presente che l’apporto solido complessivo (dalle ghiaie alle peliti) stimato per il tagliamento (brambati; 1987) è di circa 1.300.000 m3/anno e che gran parte del materiale è costituito da depositi fini (ca. 70 %) ne deriverebbe che complessivamente in un anno transitano via foce 390.000 m3 di sedimenti grossolani. secondo i calcoli precedenti (accrescimento riscontrato di circa 494.274 m3), diventa palese che all’input fluviale si deve aggiungere anche quello del trasporto lungo riva catturato dal pennello liquido del fiume. sta di fatto che sabbie si accumulano nell’area di foce in lassi temporali a scala annuale. rimane da appurare adesso se questi accumuli permangono nel tempo. per valutare questo si sono presi in considerazione i dati pregressi, editi da brambati (1987) sulla base del confronto dei rilievi del 1969 con quelli 1985. l’autore, stimando un valore medio su di un lungo periodo e in anni non molto vicini ad oggi, registra una situazione opposta a quella da noi riscontrata, con un deficit di 177.875 m3 di depositi distribuito su una superficie di 1.060.000 m2 (ca. 17 cm su metro quadrato). visti i risultanti emersi operando a scala pluriennale, si sono messi a confronto i rilievi ogs 2003 con quelli ricavati dal cnr nel 1969 (riportati da brambati, 1987) e con quelli del 1985 dello stesso autore. si specifica che per uniformità, è stata preventivamente eseguita, con il procedimento di confronto fra grid prima esposto (utilizzando il software surfer 8), la comparazione fra i rilievi cnr 1969 con quelli del 1985. il raffronto eseguito con questo metodo ha mostrato un deficit sedimentario leggermente superiore rispetto a quello prospettato dall’autore (fig. 9 a). anche se i valori assumono moduli leggermente diversi (-177.875 m3 contro i -195.728 m3) restano comunque confermate 61dinamica morfologica del litorale ... fig. 8 variazioni dello spessore dei sedimenti nell’area deltizia (rilievi ogs 2002-2003) e calcolo dei volumi. variation of the sediment thickness in the delta area (2002-2003 ogs surveys) and volume computation. le aree interessate dai maggiori cambiamenti (erosioni), che si manifestano sul fronte deltizio. i bassi fondali prossimi al litorale, mostrano invece un’abbondante deposizione di sabbie, valutabili in 1,0 ÷ 1,5 m di spessore nell’ala occidentale, e valori leggermente inferiori (0,4 ÷1,0 m) nel lobo orientale. va comunque sottolineato che anche se il bilancio volumetrico netto dell’intero paraggio risulta negativo (195.729 m3), le spiagge che bordano il delta manifestano processi di accumulo (non vale lo stesso, come abbiamo già osservato precedentemente, per quelle prossime al faro di punta tagliamento). completamente diversa risulta invece essere la situazione nei 18 anni seguenti (dal 1985 al 2003 fig. 9 b); le aree in accumulo perdono sedimenti a favore di quelle del fronte deltizio. nello specifico i maggiori accumuli si manifestano fra le batimetriche 3 e 5 sul delta front (spessore medio 1,5 m) con erosioni molto evidenti a ridosso del pennello di foce con al lato opposto, un forte arretramento della linea di costa e la creazione di un canale di sovraescavazione (spessore dei sedimenti asportati mediamente pari a 1,5 m) che si posiziona al piede delle nuove barriere frangiflutti realizzate. il bilancio di materiale indica che le aree soggette a variazioni sono pari a ca. 1.272.000 m2, delle quali, in accumulo 899.000 m2 e in approfondimento 373.000 m2. il volume conseguente è risultato essere di ca. 619.000 m3 (volume positivo), contro 177.000 m3 (perdite), con un bilancio netto positivo di ca. 442.000 m3. per completare l’analisi è stato realizzato il confronto dei fondali su un intervallo temporale di 34 anni (rilievi cnr 1969 ogs 2003; fig. 9 c). lo scenario emerso mostra un carattere stabile del sistema tendenzialmente volto alla progressione. il bilancio volumetrico netto è di ca. 242.000 m3 (corrispondente ad un volume medio annuo pari a 7100 m3/anno), con un volume positivo di 397.000 m3 (distribuito su di una superficie di 847.000 m2) mentre quello negativo risulta di ca.155.000 m3 (439.000 m2). in linea generale, la distribuzione di queste aree risulta abbastanza conforme a quella evidenziate nello studio a breve termine (ogs 2002-2003) e nell’evoluzione deltizia avvenuta dopo il 1985. in sintesi, le variazioni da noi riscontrate trovano un riscontro con le situazioni del passato: emerge dunque un incremento del materasso sedimentario sul fronte deltizio, con un predominante input proveniente da est che by -passa il pennello di foce e importanti arretramenti in 62 fig. 9 variazioni dello spessore dei sedimenti nell’area deltizia e calcolo dei volumi; a situazione 1969-1985; b situazione 1985-2003; c situazione 1969-2003. variation of the sediment thickness in the delta area and volume computation; a1969-1985 situation; b-1985-2003 situation; c-1969-2003 situation. e. gordini, r. marocco & r. ramella corrispondenza dello sbocco a mare del fiume e delle aree costiere immediatamente connesse ad esso. questo trend avviene attraverso periodi di scarso apporto solido (1969-1985; brambati 1987), seguito da fasi di stabilità più o meno lunghe, alternate a brevi periodi di forte apporto (2002-2003). in questo meccanismo risulta di fondamentale importanza l’azione disperdente operata dal moto ondoso e dalle correnti litoranee che ridistribuiscono in diverse settori, i nuovi sedimenti che entrano nel bilancio del litorale. dal confronto dei rilievi ogs 2002-2003, è possibile definire che: • i cambiamenti maggiori della spiaggia sottomarina si riscontrano in corrispondenza della zona dinamica a barre e truogoli e sono determinati dalla traslazione delle barre sabbiose da terra verso mare; • nel settore più profondo della spiaggia sottomarina le variazioni sono minime ad eccezione di due aree, localizzate a largo della costa veneta (ad una distanza compresa tra 800 e 1000 m dalla linea di riva e profondità variabile tra 5,0 e 7,0 m) e poste a cavallo di un gradino morfologico; • in corrispondenza delle bocche lagunari e della foce si registrano traslazioni di sedimento trasversalmente al litorale; • nell’area di foce del tagliamento si sono individuate due zone in accumulo, una antistante il pennello orientale (estensione: 52.000 m2; spessore minimo: 0,2÷0,3 m; spessore massimo: 1,4 m, volume stimato: 46.000 m3) e l’altra immediatamente a fronte della foce (estensione: 62.000 m2; spessore minimo: 0,2 m; spessore massimo: 1,4 m, volume stimato: 48.000 m3); • complessivamente, pur registrando locali perdite di fondale in corrispondenza dell’area prettamente di foce, l’area deltizia presenta un bilancio volumetrico positivo pari a ca. 494.000 m3; • il confronto con le variazioni subite dal litorale risultanti dai rilievi precedenti (bibione italrilievi s.n.c., 1997; lignano brambati, 1987) ha permesso di valutare le tendenze evolutive delle spiagge. 7. considerazioni conclusive i risultati ottenuti dall’analisi dei profili batimetrici della spiaggia intertidale e sottomarina, uniti alle osservazioni dirette condotte sulla spiaggia emersa e quelli più generali dedotti dalla prospezione lidar, permettono di tratteggiare una prima situazione morfodinamica delle spiagge del delta tilaventino e di tracciare una sua zonizzazione in tratti di litorale soggetti a processi erosivi, aree tendenzialmente stabili o in fase di leggera progressione. per alcuni di questi tratti, poi, è stato possibile valutare quantitativamente le variazioni registrate in un ciclo annuale (2002-2003) e, utilizzando dati pregressi, in due segmenti pluriennali (1969 – 2003 e 1985 – 2003). per quanto attiene alla spiaggia sottomarina emerge che, salvo rare eccezioni, questa rimane generalmente stabile nel periodo considerato salvo in corrispondenza delle bocche lagunari e alla foce del tagliamento e di due zone dell’ala occidentale del delta. segnatamente, incrementi e decrementi dei depositi di fondo diventano sensibili in corrispondenza della foce del tagliamento e delle bocche lagunari di lignano e porto baseleghe. qui i pennelli liquidi delle acque fluviali e lagunari deviano verso il largo i depositi che transitano in queste zone, incrementando così i fondali immediatamente prospicienti. diversa è invece la situazione riscontrata al largo di bibione (tra 3,0 e 6,0 m di profondità) dove in un’area piuttosto estesa si rinviene un accumulo di sedimenti che provengono dall’intensa erosione costiera delle spiagge immediatamente più ad est (litorale di bibione – lame di revelino e punta faro). la relativa stabilità di quest’accumulo negli anni di rilievo fa supporre che i depositi una volta abbandonati in quest’area dagli agenti che hanno determinato l’erosione costiera, tendano a stabilizzarsi e permanere nel tempo, non venendo più ripresi dall’azione di dispersione del moto ondoso. ciò determina una condizione che, almeno in prima ipotesi e data la loro granulometria si prospetta ottimale per un utilizzo come cava di prestito di questi accumuli da destinare ad opportune ricariche artificiali della spiaggia di pineta punta faro – lame di revelino, soggetta ad intensa erosione. altri fattori che inducono a questa ipotesi di intervento è la presunta affinità granulometrica dei sedimenti che in sostanza sono quelli erosi dal litorale che si vuol ricomporre e anche la limitata distanza fra area di presa e spiaggia da risanare. e’ evidente, comunque, che quest’operazione di riequilibrio del litorale, se attuata, deve essere corredata da opportune opere di ritenuta di questo materiale che viene riportato artificialmente alle condizioni iniziali. per quanto attiene, invece, le aree all’interno della zona a barre e truogoli e quelle intertidali, emerge che i tratti soggetti a maggiori cambiamenti sono: • quelli contraddistinti dalla migrazione delle barre nell’ambito dell’area più dinamica della spiaggia sottomarina; • quelli in continua erosione (o progressione) determinata da fattori naturali e/o dalle opere di difesa che si sono stratificate lungo il litorale; • la foce del tagliamento e le bocche lagunari. i cambiamenti volumetrici nell’area delle barre e truogoli sono determinati quasi sempre da semplici traslazioni verso mare o verso terra delle barre e non da reali impoverimenti complessivi della zona dinamica; in altre parole le perdite corrispondono quantitativamente agli acquisti con un bilancio complessivamente in pareggio. in generale, come dimostrato da più lavori, durante il periodo estivo le barre si trovano in posizione più ravvicinata alla linea di costa e viceversa durante quello invernale. differente è invece la situazione nell’area della spiaggia intertidale dove erosioni e progressioni della linea di riva e dei fondali del terrazzo di bassa marea sono causate da fattori naturali a volte agevolati, indotti e altre volte, vanamente ostacolati dalle opere di difesa marina. così nell’ala orientale del delta, nei litorali connessi alla bocca lagunare di lignano, si delinea una leggera instabilità delle spiagge anche se difese da una serie di pennelli impermeabili ed opere aderenti. qui le maggiori variazioni degli arenili sono condizionate dalle continue modificazioni interne della bocca lagunare (argini marginali e canali interni) che si ripercuotono sui lidi adiacenti e dall’altro, dalla deviazione verso il largo del trasporto litorale attuato dal suo pennello liquido. la porzione centrale del litorale di lignano mostra un 63dinamica morfologica del litorale ... carattere tipicamente stabile con fasi di progressione naturale, confermata anche a lungo termine. il tipico profilo di spiaggia mostra un’estesa parte emersa, come anche quella intertidale che si raccorda dolcemente ad una sviluppata zona a barre e truogoli. a questa, verso mare, succede un fondale sub -pianeggiante che si unisce al protendimento sabbioso dell’ebb tidal delta di lignano. più ad ovest, le spiagge di pineta lungomare adriatico, manifestano anch’esse una situazione tendenzialmente stabile, con temporanee condizioni regressive determinate dalla carenza di apporti sedimentari provenienti da est, secondo il trasporto prevalente, ma anche da ovest, a causa dell’effetto schermante di diverse opere di difesa che impediscono l’arrivo di nuovi sedimenti dal tagliamento. la situazione più critica, comunque, si registra in corrispondenza delle spiagge di riviera, difese vanamente da una serie di pennelli che hanno solo in parte mitigato l’erosione in atto da tempo. in questo tratto di litorale è evidente l’assenza di nuovi arrivi di sedimenti da ovest, come da est e il prevalente trasporto perpendicolare alla spiaggia, in parte determinato anche da una convergenza del moto ondoso. per tutti questi motivi questo tratto di litorale necessita, quasi obbligatoriamente, di un’alimentazione forzata, con ripascimenti di opportuni depositi prelevati in aree prossimali e il loro contenimento con idonee opere marittime. stante questa situazione, nel dettaglio si segnala che i lunghi pennelli di sbarramento e la loro serie ravvicinata, più che una cattura dei depositi che transitano lungo riva hanno solamente prodotto una parziale stabilizzazione delle sabbie all’interno delle celle tra due pennelli contigui. nel versante opposto, nell’ala occidentale del delta, dopo la zona prettamente di foce, si registra una situazione abbastanza simile a quella prima riscontrata: il litorale più orientale di bibione evidenzia una sensibile instabilità che ha portato recentemente, alla realizzazione di tre pennelli permeabili al fine di fermare la situazione erosiva in atto. l’aggetto e la spaziatura di queste opere, comunque, non appaiono le più indicate date le reali caratteristiche di trasporto di questo tratto di litorale. condizioni evolutive distinte esibiscono la parte centrale e occidentale del litorale di bibione, contrassegnate essenzialmente da una situazione stabile volta alla progressione. nello specifico, i caratteri peculiari del tratto centrale dell’ala deltizia (la configurazione convessa della linea di riva, l’estensione e la pendenza della spiaggia emersa, l’ampiezza della zona intertidale), confermano la stabilità della stessa e suggeriscono un carattere tendenzialmente deposizionale. proseguendo ancora verso l’estremità del delta (bocca di baseleghe), la spiaggia, dopo una prima riduzione dell’ampiezza (non determinata da una regressione in quanto stabile nel tempo considerato), palesa un notevole sviluppo nella parte intertidale ed uno spiccato allungamento verso ovest. ciò determina una progressiva occlusione e un trascinamento in questa direzione, della freccia litorale dell’ala occidentale del delta. anche la spiaggia più al largo confermano questa tendenza, mostrando le tipiche bedforms, legate al moto ondoso, che si generano nelle zone sub pianeggianti prossime alle bocche lagunari. la situazione più complessa dell’intero litorale si registra alla foce del tagliamento e alle sue sponde dove una serie di opere di difesa parallele e trasversali realizzate alla destra a partire dal 1966, probabilmente con finalità differenti, sono state costruite al fine di contrastare la naturale evoluzione regressiva del tratto apicale del delta. senza entrare nel merito all’attuale funzionalità di queste opere, si vuol qui sottolineare che se hanno bloccato, in parte, o generalmente rallentato i processi erosivi in atto da tempo, hanno però determinato condizioni di instabilità nelle aree immediatamente adiacenti. a ciò si aggiunga l’impatto visivo di queste costruzioni antropiche (barriere frangiflutti in massi) che contrasta con l’equilibrio delle forme naturali, tipico di una spiaggia e a maggior ragione in un delta di un fiume che viene considerato uno dei più naturali d’europa. nel versante opposto, il litorale viene pesantemente condizionato da pennello di foce (eseguito nel 1963) e recentemente accorciato. complessivamente nell’area fociale si assiste ad un progressivo arretramento della spiaggia emersa (parte occidentale) con messa a nudo dei depositi di lama sottostanti, alla quasi scomparsa del terrazzo di bassa marea, all’assottigliamento della zona a barre e truogoli, sostenuta da un’unica barra. le scogliere variamente sagomate, i tubi tipo longard, riempiti di sabbia, le continue alimentazioni artificiali della spiaggia con materiale scavato dalla foce (ca. 24.000 m3 di sedimenti nel solo anno 2005, con previsioni future di ca. 50.000 m3 ogni anno), hanno solo in parte tamponato l’erosione apicale del delta che, in pochi anni ha portato alla distruzione di buona parte delle splendide dune litorali. fermo restando che questo processo di adattamento della foce alle nuove condizioni ambientali non sembra essersi concluso, e quindi che la vigente situazione può perdurare nel tempo e d’altro canto, permane la necessità di garantire il passo marittimo alla foce di questo importante fiume, si ritiene che senza risagomare e approfondire esageratamente l’alveo, con prevedibili conseguenze sulle sponde e sull’asta terminale del fiume, i materiali idonei a bilanciare l’erosione costiera possono essere ricercati negli accumuli rinvenuti nell’area a ridosso del delta. si ricorda che complessivamente alla foce, in un anno, si registra un bilancio volumetrico positivo di ca. 490.000 m3 di sedimenti di cui circa 90.000 nelle aree di accumulo individuate in questo lavoro. l’asportazione di limitati spessori (ca. 0,5 m) da questi accumuli dovrebbe essere ricompensata a breve termine dall’appurata ricarica naturale, determinata dalla dinamica evolutiva della parte frontale del delta. il prelievo di questo materiale, comunque, deve essere inteso come una semplice integrazione di quello ricavato dalla escavazione del letto del fiume (valutato in circa 68.000 m3 e 166.000 m3 per raggiungere rispettivamente le profondità di 2,5 e 3,5 m ed una larghezza del canale di 100 -150 m). ringraziamenti si ringrazia il comune di lignano sabbiadoro e di san michele al tagliamento per aver finanziato lo studio dell’ogs “indagini meteo-oceanografiche, batimetriche, sedimentologiche e morfologiche finalizzate allo studio dei fenomeni di dinamica costiera lungo i litorali di lignano sabbiadoro e di bibione” e per la loro costante partecipazione in fase di realizzazione dello stesso. un ringraziamento va inoltre alla bibione spiaggia s.r.l., nella persona del geom. g. bittolobon e dei suoi 64 e. gordini, r. marocco & r. ramella collaboratori che hanno fornito un fondamentale supporto logistico durante le fasi di acquisizione dei dati e messo a nostra disposizione tutti gli studi eseguiti in passato. si ringraziano inoltre il personale dell’istituto nazionale di oceanografia e di geofisica sperimentale – ogs di trieste che, a vario titolo, ha offerto contributi utili alla stesura del presente lavoro: un caldo ringraziamento va a m. deponte, r. romeo e n. zanette (gruppo gea), f. donda (gruppo gepa), r. nair (gruppo cto) e p. paganini (gruppo carst). un ringraziamento profondamente sentito va all’”anonimo” revisore della rivista che con i suoi puntuali, motivati e molto pertinenti suggerimenti ha migliorato di molto l’articolo inviato alla stampa. bibliografia ashley g. m., symposium chairperson (1990) classif ication of large-scale subaqueous bedforms: a new look at an old problem. jour. of sedim. petrol., 60, 1, 160 -172. brambati a. (1970) provenienza, trasporto e accumulo dei sedimenti recenti nelle lagune di marano e di grado e nei litorali tra il f. isonzo e tagliamento. mem. soc. geol: ital., 9 (4), 281-329. brambati a. (1985) morfologia del delta del f. tagliamento e delle sue spiagge. in “raccontare lignano”, benvenuto edit. brambati a. (1987) studio sedimentologico e marittimo-costiero dei litorali del friuli venezia giulia. servizio idraulica della regione friuli venezia giulia, pp. 67. brambati a., catani g., marocco r. (1977) indagini sedimentologiche sulla spiaggia sottomarina dell’adriatico settentrionale tra i fiumi brenta e tagliamento. boll. soc. geol. it., 96, 69-86. brambati a., catani g., lenardon g., marocco r. (1982) rilievi sul litorale da monfalcone alla foce dell’ adige. c.n.r., p.f. “conservazione suolo”, s.p. “dinamica dei litorali”. tipografia nazionale. brambati a., venzo g.a. (1967) recent sedimentation in the northern adriatic sea between venice and trieste. st. trent. sc. nat., sez. a, 44(2), 479-493. capobianco m., hamm l., silva p. (1999) interventi di ripascimento nelle coste europee: ricadute a livello italiano. studi costieri, 1, 3-12. carobene l. (1978) analisi morfologica quantitativa delle spiagge dell’alto adriatico tra monfalcone e lignano. boll. soc. geol. it., 97, 131-164. carobene l., brambati a. (1975) metodo per l’analisi morfologica quantitativa delle spiagge. boll. soc. geol. it., 94, 479-493. catani g., lenardon g., marocco r., tunis g. (1982) rapporto sulle ricerche morfologiche e sedimentologiche effettuate nel 1976 nella spiaggia modello di valle vecchia (venezia). boll. soc. adriat. sc., lxvi, 73-103. catani g., marocco r. (1976) considerazioni sulle caratteristiche mareografiche e anemografiche a san nicolò di lido, runta tagliamento e grado. quaderni della ricerca scientifica, 92, 21-25. catani g., marocco r., brambati a., carobene l. & lenardon g. (1978) indagini sulle cause dell’erosione nel tratto orientale del litorale di valle vecchia (caorle, adriatico settentrionale). mem. soc. geol. it., 19, 399-405. de girolamo p., cecconi g., noli a., maretto g.p., contini p., (1999) monitoraggio della spiaggia di cavallino. studi costieri, 1, 13-25. fontolan g. & sartori di borgoricco m. (2000) caratteri morfodinamici e sedimentologici della bocca lagunare di s. andrea (laguna di marano). estratto da: la ricerca scientifica per venezia vol. ii, tomo ii, 983-991. fontolan g (2004) la fascia costiera, capitolo 4. xi. estratto da: geomorfologia della provincia di venezia (note illustrative della carta geomorfologica della provincia di venezia). esedra edit., pp. 514. gordini e., marocco r. & vio e. (2002) stratigrafia del sottosuolo della “trezza grande” (golfo di trieste, adriatico settentrionale). gortania, 24, 31-63. gordini e., caressa s., marocco r. (2003) nuova carta morfo-sedimentologica del golfo di trieste (da punta tagliamento alla foce dell’isonzo). gortania, 25, 5-30. gordini e., marocco r., tunis g., ramella r. (2004) i depositi cementati del fondale del golfo di trieste (adriatico settentrionale): distribuzione areale, caratteri geomorfologici e indagini acustiche ad alta risoluzione. il quaternario, 17 (2/2), 555-563. hayes m.o. (1980) general morphology and sediment patterns in tidal inlets. sed. geology, 26, 139-156. king c.a.m. (1972) beaches and coasts, (2nd ed). edward arnold, london, pp. 570. marocco r. (1988) considerazioni sedimentologiche sui sondaggi s19 e s20 (delta del f.tagliamento). gortania, 10, 101 –120. marocco r. (1989) evoluzione quaternaria della laguna di marano (friuli venezia giulia). il quaternario, 2, 125137. marocco r. (1991) evoluzione tardopleistocenica-olocenica del delta del f. tagliamento e delle lagune di marano e grado, (golfo di trieste). il quaternario, 4(1b), 223-232. marocco r., pessina m. (2000) il rischio litorale nell’area circumlagunare del friuli venezia giulia. gortania, 17, 5-35. passega r. (1964) grain size representation by cm patterns as a geological tool. journ. sed. petr. 34, 830-847. vischer g. s. (1969) grain size distribution and depositional processes. journ. sed. petr. 39, 10741106. ramella r., viezzoli d., gordini e., codiglia r., romeo r., deponte m. (2004) indagini meteo-oceanografiche, batimetriche, sedimentologiche e morfologiche finalizzate allo studio dei fenomeni di dinamica costiera lungo i litorali di lignano sabbiadoro e di bibione. istit. naz. di oceanogr. e di geofis. sperim. di trieste. rel-28/2004 oga 8. zunica m. (1971) ricerche sulle variazioni delle spiagge italiane – le spiagge del veneto. consiglio nazionale delle ricerche, tipografia antoniana, padova. pp. 141. 65 ms. ricevuto il 17 gennaio 2006 testo definitivo ricevuto il 31 maggio 2006 ms. received: january 17, 2006 final text received: may 31, 2006 dinamica morfologica del litorale ... available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 36 (2), 2023, 149-183 1. introduction the specific geographic location of italy as a peninsula bridging continental europe to the mediterranean and its variety of geomorphological units from the alps across the apennines to the large plains, from volcanos to shorelines, allowed the formation of a plethora of environmental niches with specific pedoclimatic conditions, thus supporting the evolution of many different soils during the pleistocene. paleopedological studies in italy and the international debate on the genesis, classification, rates of development and paleoclimatic record of paleosols in this country have been missing until the last two decades of the 20th century. since then, some papers started dealing with paleosols distributed along the italian territory, especially in the north and central sectors of the peninsula. therein, paleosols (i) were identified in sedimentary archives as markers of stages recording relative geomorphological stability (phyto/ biostasy conditions vs. rhexistasy); (ii) were described in the field from a qualitative point of view; (iii) were assumed as paleoclimatic indicators by comparing their main morphological features in terms of past climatic conditions (especially of glacial/cold and interglacial/ https://doi.org/10.26382/amq.2023.06 pleistocene paleosols of italy: pedostratigraphy, genesis, paleoclimate and geoarchaeology fabio scarciglia 1 , daniela sauer 2 , andrea zerboni 3 1 dipartimento di biologia, ecologia e scienze della terra (dibest), università della calabria, arcavacata di rende (cs), italy. 2 department of physical geography, institute of geography, university of göttingen, göttingen, germany. 3 dipartimento di scienze della terra “a. desio”, università degli studi di milano, milano, italy. corresponding author: fabio scarciglia <fabio.scarciglia@unical.it> abstract: this paper provides the first comprehensive, critical review on pleistocene paleosols of italy over about the last for decades. we summarize methodological approaches and major scientific findings from case studies throughout italy, in both natural environments and human-influenced (archaeological) contexts. many researchers showed the relevance of paleosols as pedostratigraphic and chronostratigraphic markers, useful for cross-correlations, geological mapping and reconstruction of the geomorphological evolution of quaternary landscapes. considering the variety of italian paleosols, scholars introduced, applied and discussed crucial concepts in soil science, such as pedostratigraphic level, geosol or pedocomplex to reconstruct paleotopographies over time and space. we also discuss the value of paleosols that received distal volcanic input from pleistocene explosive eruptions as (crypto)tephrostratigraphic markers, along with the neogenesis of short-range order minerals and development of andic properties as paleoenvironmental proxies. several authors explored the effect of time and duration of exposure of parent materials to pedogenesis on the degree and direction of soil development as observed in soil chronosequence studies. several among these studies revealed the efficiency of pedogenic iron forms to compare stages of soil formation with age. many studies emphasized the potential of paleosols for paleoclimatic and paleoenvironmental reconstructions, often achieved through combining different analytical techniques and natural archives, among which the role of micromorphology gained considerable importance. prominent clay illuviation and rubification due to hematite formation were interpreted as diagnostic of warm and humid paleoclimates, typical of pleistocene interglacials. illuviation of coarser particles, platy, lenticular or cuboid pedogenic structures, banded fabric, ice wedge casts and other macroand microscale features were considered as indicative of past seasonal freezing in colder environments during pleistocene glacial stages, when also loess deposition took place in northern italy. with respect to secondary carbonate accumulation, some papers invoked cold and dry climatic shifts during glacials or stadials, although this feature may reflect a wide range of paleoclimatic conditions. an interesting discussion arose on the complex genesis of fragipans, plinthite and petroplinthite. many case studies focused on paleosols related to archaeological contexts, where paleopedological and geoarchaeological investigations offer the possibility to understand the relations between settlements distribution, human impact and adaptation to geological, geomorphological, paleoclimatic and paleoenvironmental dynamics. worth mentioning are also the assessment of paleosol quality and their intrinsic pedodiversity as geoheritage, with respect to fertility for agricultural purposes and their pollution with potentially toxic elements, given the uniqueness and irreproducibility of specific pedogenic properties. other novel aspects and applications concern geotechnical and construction purposes, such as the suitability of certain paleosols for building foundations and the evaluation of the response to seismic events in urban areas. we draw further attention on key issues regarding the paleopedological approach, addressed by various authors or still needing investigations. a common problem arises from the lack of some genetic horizons after erosion, overprinting by younger pedogenesis due to surface exposure or changes in soil properties after burial, poor resilience of paleosols with respect to natural and anthropogenic threats, because of the long time required for acquiring specific properties. their multifaceted nature represents a valuable tool for predicting the potential responses of the earth system to forthcoming scenarios and providing best-suited strategies for sustainable land planning, adaptation and mitigation of geological hazards. keywords: soil chronosequences; soil micromorphology; paleoenvironmental reconstruction; volcanic input; human settlements and artifacts. 150 scarciglia f. et al. warm, subtropical or tropical climates) considered either similar to or different from the present -day environment; (iv) were investigated in correspondence of archaeological evidence to support their dating and paleoclimatic recosntruction (cremaschi et al., 1984; cremaschi, 1987; coltorti & dramis, 1988; cremaschi et al., 1990; cremaschi & van vliet-lanoë, 1990; busacca & cremaschi, 1998). other papers published during the last two decades of the last century included the study of paleosols in the frame of a more comprehensive geomorphological evolution. among these, amato & dimase (1997) applied soil micromorphology to investigate soil genesis and relate it to quaternary paleoclimatic shifts. a few attempts aimed at quantifying the degree of paleosol development using a soil chronosequence approach (arduino et al., 1984, 1986). since the early 2000s to nowadays there has been a flourishing of studies focused on paleosols, from both natural landscapes and archaeological settings throughout italy, as well as on stratigraphic markers, paleoclimatic/ paleoenvironmental proxies and indicators of different time spans. several multiproxy, multidisciplinary and multianalytical methodological approaches contributed to this substantial knowledge gain. in this work, we provide some of the major research advances on pleistocene paleosols of italy (fig. 1) from the aforementioned perspectives over more than the last four decades through a first comprehensive review on this topic. this review occasionally includes holocene soils as well, namely when a comparison of pedogenic features formed in the pleistocene and holocene enables a deeper understanding of the corresponding paleoenvironments, as well as in those cases when pedogenesis in certain paleosols started in the pleistocene but continued diachronically into the holocene, sometimes overprinting the pleistocene features to some extent. our critical analysis of the available literature also focuses on traditional and innovative techniques applied to paleopedological studies, often emphasizing several pedogenic features which are recurrent in different regions of italy and are diagnostic of specific genetic processes and corresponding (paleo) environments (table 1). in addition, we provide an overview of major applications, problems or open questions raised or addressed in the literature, including an overview on the application of paleopedology and related techniques to the study of archaeological soils. in fact, soil science is crucial in the reconstruction of processes involved in the formation and weathering of anthropogenic pedosedimentary sequences and in tracing evidence of human settlements on ancient topographic surfaces. a particular interest arises from the location of italy in the central mediterranean basin encompassing many different ecological settings (including paleosols related to human ecology), which makes it particularly sensitive to pleistocene, current and future climatic changes and related natural hazards. the latter are enhanced by the tectonic activity at the boundary be tween the african and eurasian plates, as well as by an increasing human impact, which threatens the pedodiversity of paleosols as heritage and georesource. 2. pedostratigraphy, chronostratigraphy and geomorphological implications field observation of paleosols is commonly used to separate phases of sedimentation from those characterized by absence of deposition, often coupled with prevalent weathering and soil formation processes, and possibly marked by episodes of erosion (fig. 2). where paleosols extend over wide areas, they may allow for correlating underlying and/or overlying sedimentary successions in space and time, even at regional scale (tens to hundreds km2 at least), and tracing surfaces or buried paleotopographies. the north american commission on stratigraphic nomenclature defined a geosol as the fundamental pedostratigraphic unit (nacsn, 1983, 2021; catt, 1998). it consists of a laterally traceable, mappable, geological weathering profile or threedimensional body of soil material comprising one or more differentiated pedogenic horizons, which has a consistent stratigraphic position and is buried by younger deposits at least in a reference site. although the international commission on stratigraphy (ics), which fig. 1 map of italy showing regions and major geographic place names where the study sites reported in the cited literature are located. base map: eric gaba and nordnordwest, cc by-sa 3.0 <https://creativecommons.org/licenses/by-sa/3.0>, via wikimedia commons. 151 pleistocene paleosols of italy: ... the northern apennines fringe. the author attributed major loess aggradation to the penultimate glacial period, whereas he ascribed fersiallitic pedogenesis and leaching/hydromorphic features to the penultimate and the last interglacial, respectively. cremaschi (1987) also introduced the concept of vetusols (see section 3) based on a combined study of quaternary geology and paleopedology of the pleistocene terrace staircase along the po river plain (northern italy). there, he identified relict paleosols, developed on alluvial, loessic and glacial deposits and, exposed at the present, stable topographoversees the matters relating to the world chronostratigraphic chart and the corresponding geological time scale within the international union of geological sciences (iugs), has never approved the use of pedostratigraphic units, several researchers have developed concepts around this topic and applied them to specific case studies. cremaschi (1978) was one of the italian scientists who first used lithostratigraphic and pedostratigraphic units to fix hypothetical chronological constraints and derive paleoclimatic shifts recorded in loess deposits with embedded paleosols on quaternary terraces in pedogenic features responsible processes paleoenvironmental/ paleoclimatic conditions major periods of development main geographic location rubification (matrix reddening) diffuse release of fe from mineral weathering and formation of ferrihydrite during moist winters, recrystallization into hematite during warm and dry summers warm and humid, seasonally contrasted pleistocene interglacials piedmont, liguria, lombardy, emilia romagna, tuscany, marche, abruzzo, molise, basilicata, calabria, sardinia, sicily illuvial clay coatings/ infillings and bt horizon translocation of clay particles temperate to warm and humid, seasonally contrasted pleistocene interglacials/ interstadials piedmont, liguria, tuscany, abruzzo, marche, molise, basilicata, calabria, sardinia, sicily fe/mn mottles, coatings, concretions, nodules segregation of fe/mn oxides caused by reduction, redistribution and precipitation by re-oxidation temperate to warm and humid, seasonally contrasted; hydromorphic pleistocene interglacials and glacials; waterlogging throughout the quaternary piedmont, lombardy, emilia romagna, marche, abruzzo, campania, calabria, sardinia carbonate coatings, concretions, nodules and bk horizon dissolution, leaching and precipitation of carbonate arid/semiarid (cold and dry; warm and dry; subhumid (temperate to warm and humid) pleistocene glacials and interglacials; holocene veneto, abruzzo, marche, molise, apulia, basilicata, calabria, sardinia loess wind erosion, transport and deposition of mostly glacierand meltwaterground rock grains arid/semiarid; bare soil as sediment source; grass and low shrubs as sediment traps pleistocene glacials/stadials; holocene dry spells piedmont, lombardy, veneto, emilia romagna, tuscany platy, lenticular structure and banded fabric alternation of ice lense formation and melting cold, with diurnal and seasonal temperature contrast pleistocene glacials/stadials piedmont, liguria, campania illuvial silt coatings/ infillings freeze-thaw cycles and silt translocation with intense meltwater flushes; intense rainfall on bare soil; agricultural practices cold, with diurnal and seasonal temperature contrast; poorly vegetated soil; ploughed and/or irrigated soil pleistocene glacials/stadials; holocene human-impacted soils piedmont, lombardy, liguria, campania, calabria, sardinia degenerated clay coatings freeze-thaw cycles (cryoturbation); shrink -swell dynamics (argilloturbation); bioturbation; anthropogenic activities cold, with diurnal and seasonal temperature contrast; faunal activity and/or vegetation cover; human impact pleistocene glacials/stadials; pleistocene inter­glacials/ interstadials; holocene humanimpacted soils tuscany, abruzzo, campania, calabria, sardinia cryoturbated horizons and wedge casts seasonal or permanent soil freezing and differential increase of ice volume cold, with diurnal and seasonal temperature contrast or permafrost pleistocene glacials/stadials piedmont, lombardy, liguria, calabria volcanic input volcanic eruptions and tephra/ cryptotephra deposition all throughout the quaternary umbria, abruzzo, latium, campania, molise, calabria, sicily vitric properties poor degree of weathering of tephra all throughout the quaternary latium, campania, molise, sicily andic properties neogenesis of short-range order minerals from the weathering of volcanic glass humid with udic soil moisture pedoclimate and free drainage pleistocene inter­glacials and milder glacial interstadials abruzzo, latium, campania, molise, calabria vertic properties and bss horizon shrink-swell dynamics and expandable clays alternation of imbibition/ desiccation of clays pleistocene glacials and interglacials lombardy, marche, molise, campania, calabria, sicily fragic properties and bx horizon freeze-thaw cycles; shrink-swell cycles; hydro-consolidation; seismic shaking and liquefaction; bonding by precipitated fe, al, si and/or clays cold, with diurnal and seasonal temperature contrast; all pleistocene glacials; throughout the quaternary lombardy, piedmont, tuscany, calabria plinthite, petroplinthite laterization processes and fe oxide segregation warm and humid pleistocene interglacials liguria, tuscany pedorelicts soil reworking all; anthropogenic impact throughout the quaternary lombardy, abruzzo, campania, apulia, calabria tab. 1 summary of major paleopedological features, associated processes and their paleoclimatic interpretation . ic surfaces, which underwent the same set of soil formation processes (decarbonation, rubification and clay illuviation) over time, i.e. keeping the same direction of pedogenesis, though less intense moving from older to younger surfaces, across the terrace-soil chronosequence. also, in the campania region (southern italy), magliulo et al. (2006) were able to distinguish different stacked lithostratigraphic units, separated by erosive discontinuities, within the early pleistocene, clastic alluvial fan succession of the eboli conglomerates, based on the study of intercalated (buried) paleosols. among these, the so-called paleosol of eboli (along with some k/ar-dated pyroclastic layers) permitted correlations between varying stratigraphic sections and proved to be a good pedostratigraphic marker in the area, also adding a potential climatic signature of warm and humid conditions of the mis 25 interglacial. in the sila massif upland plateaus (calabria, southern italy), scarciglia et al. (2008) defined an informal geosol in the surroundings of the cecita lake, which is an artificially dammed reservoir occupying a pleistocene morphotectonic depression that once hosted an ancient, extinct lake. soil charcoal content therein dated mostly to the holocene and limitedly to the late pleistocene, in line with the main pedological features (organic matter accumulation, clay illuviation, neogenesis of phyllosilicate and poorly crystalline clay minerals) and archaeological remains, the latter spanning from late neolithic to roman times (pelle et al., 2013; moser et al., 2017). noteworthy in that area is the partial contribution of very fine (micrometric) volcanic ashes, sourced from the aeolian islands archipelago (southern tyrrhenian sea, ne of sicily), to soil development, in addition to the in situ weathering of granitoid rocks and associated sediments. this finding permitted to use the sila upland soil as a potential (crypto)tephrostratigraphic marker. however, repeated late pleistocene and holocene explosive eruptions dispersed their distal, pyroclastic products with similar (rhyolitic) composition in the sila plateaus, thus not allowing the identification and dating of a single eruptive event and corresponding age (scarciglia et al., 2008; raab et al., 2017). the timetransgressive (diachronous) genesis of the ash-bearing sila upland soil, which in this case formed in various substrates of different ages, and the dominant exposure at the surface of the cecita lake geosol, only in places buried by alluvial, colluvial and detrital slope deposits, imply that it cannot be considered a chronostratigraphic unit. modern pedogenesis and anthropogenic disturbance may be partly superimposed on it, and partial truncation by surface erosion processes may cause a partial loss of “soil memory”. nonetheless, it still appears a reliable pedostratigraphic marker and record of the late pleistocene to middle holocene pedogenesis, indicating relatively stable geomorphic conditions, followed by late holocene episodes of severe erosion/sedimentary aggradation. it is a useful tool to constrain both older and younger soils and deposits and morphodynamic processes for more extensive correlation. paleosols have demonstrated to be very useful in quaternary geology surveys and mapping. napoli et al. (2006) and costantini et al. (2007b) applied soil surveys and paleopedological studies to generate detailed maps of the quaternary soil cover in a pilot area of tuscany (central italy) using geographic information system (gis). they produced pedostratigraphic maps representing ancient buried surfaces from the early to the middle and late pleistocene (and the holocene), derived from the regolith thickness and the estimated soil ages. different pedostratigraphic sequences were identified based on pedostratigraphic levels (pls), defined as characteristic assemblages of soil genetic horizons, formed in parent materials exhibiting a similar degree of weathering and a maximum age estimated by means of 152 fig. 2 (a) erosive and depositional unconformities marked by paleosols in a middle pleistocene stratigraphic sequence in the molise-apulian apennines between the trigno and fortore rivers (photo courtesy of v. bracone). (b) pleistocene pedostratigraphic succession alternating tephra and volcanic ash-bearing paleosols in the sessano intramontane basin (molise apennines). scarciglia f. et al. (2012) and amorosi et al. (2014b) also integrated paleosol information with the principles of sequence stratigraphy to delineate systems tract equivalents even in nonmarine successions and trace their quaternary geomorphological, tectono-sedimentary evolution. in some cases, the constraints obtained from the reconstruction of the deep pedostratigraphic architecture of river or coastal plains permitted to estimate sedimentary aggradation rates and paleoclimatic changes (fontana et al., 2014; bruno et al., 2017) and to use paleosols as regional stratigraphic markers for long-distance correlations, also supported by key pedochemical fingerprints (amorosi et al., 2021). such an approach of longdistance correlations based on the visual identification of buried paleosols (or soil horizons) along deep cores offers a tool to accomplish paleogeographic reconstructions up to the scale of sedimentary basin, although a major methodological bias was suggested by aghib et al. (in press). considering a deep core of pleistocene sediments from the northern po plain, they performed a micropedological investigation on layers visually interpreted as paleosols. their findings highlighted that only a few of them were real paleosols, whereas some others were preweathered and pedogenized sediments consisting of reworked and eroded paleosol material (geological pedorelict), layers of accumulation of caco3 related to the presence of groundwater (deep groundwater calcrete), or fe-enrich layers interpreted as buried iron bogs. a noteworthy example of the study of paleosols along deep sequence is represented by the so called caranto paleosol, found in cores from the central sector of the lagoon of venice (ne italy), outcropping in the fields during tillage, and referenced in ancient chronicles of local architects and builders (mozzi et al. 2003; donnici et al., 2011). this late pleistocene to early holocene paleosol is a compact layer (as expressed by the term caranto itself, which in the local dialect of peasants indicates hard, cemented horizons). according to mozzi et al. (2003), it consists of white calcic and greyish gleyic (with yellowish fe-hydroxide-rich mottles) pedogenic b and c horizons. it occurs at a depth of some meters from the topographic surface, often forming centimeterthick crusts, on top of distal alluvial plain sediments and overlain by transitional marine, lagoon and continental deposits. it is well-correlated with spatial continuity to the calcisols inland, and the alternation of oxidizing and reducing conditions, in response to groundwater fluctuations, are considered responsible of its pedogenic features. the time of pedogenesis of the caranto paleosol was estimated in a large range of 8,000-12,000 years and it marks a major stratigraphic uncomformity in the venice lagoon area separating the last glacial maximum from the holocene. the role of paleosols as pedostratigraphic markers in the frame of quaternary morphotectonic evolution (and paleoclimatic) reconstructions was also investigated by several researchers. zembo (2010) and zembo et al. (2011) focused on paleopedological characterization to unravel the interplay between tectonic activity, local base-level changes and climate in controlling alluvial dynamics in quaternary alluvial sediments of the val d’agri basin (southern italy). livio et al. (2009, 2014, 2020), zerboni et al. (2015) and perini et al. (2023) performed a detailed investigacorrelation to benchmark soils (costantini & priori, 2007). this approach proved to be a useful tool to identify differential tectonic uplift across the study area, even where the soil cover may hide surface evidence of faults underneath. further improvement of this approach came from geologists who identified stacks of unconformitybounded stratigraphic units (ubsus), marked by buried paleosols, thus using a quaternary geology approach in paleopedology. these often allowed to distinguish different synthems (capezzuoli et al., 2009; zuffetti & bersezio, 2021), together with their specific sedimentary facies associations, discontinuities and erosive boundaries (andreucci et al., 2010; giraudi et al., 2011; pascucci et al., 2014; di celma et al., 2016; bruno et al., 2017, 2020; morelli et al., 2017). this approach contributed to reconstruct 2d to 3d geological/ geomorphological and temporal evolution models from exposed outcrops and/or cores drilled in subsurface sedimentary successions of past marine and continental realms, especially where paleosols have large lateral continuity. in particular, coltorti & pieruccini (2006) studied in detail some pedocomplexes (compound geosols, i.e. sequences of overlapping paleosols of different ages formed on different lithologic units; nacsn, 1983) dating to the last interglacial from several sites in central italy. the pedocomplexes consisted of three buried, truncated paleosols, separated by erosive surfaces and/ or stone lines, marking the passage between the late middle pleistocene (mis 6) and late pleistocene (mis stages 4 and 2) ubsus, developed on calcareous fluvial and moraine gravels with minor flints. their main features are red colors, illuvial clays, secondary carbonate accumulation and bioturbation, which are consistent with the triplet of mis 5e-5c-5a last interglacial stages. these allow detailed correlation with similar paleosols and pedocomplexes already observed in other sectors of the central apennines, but conversely display dissimilar features and lesser degree of weathering than younger late pleistocene and holocene soils. almost the same time period including the last two glacial cycles (and older stages) is recorded in thick, continental (glaciofluvial) and shallow marine sedimentary successions from the venetian plain (ne italy) (marcolla et al., 2021). the authors provided detailed multiproxy data from deep cores on the stratigraphic architecture and landscape evolution. integrated stratigraphic, palynological, micropalaeontological, geochronological and paleopedological results showed that alluvial aggradation phases correlate to glacial culminations in the alps, which alternated with marine transgressions and/or soil formation during intervening interglacials. paleosols therein contributed to correlate mutually different core sections, similarly to other works where they were interbedded in pleistocene alluvial fan deposits and, although often truncated, served as pedostratigraphic markers and paleoclimatic proxies, from several sites of north, central and south italy (giaccio et al., 2004; robustelli et al., 2005a; carboni et al., 2006; magliulo et al., 2006; carnicelli et al., 2015; marcolla et al., 2021). other works worth mentioning are those of villa et al. (2016b) and amorosi et al. (2015), who coupled electrical resistivity tomography (ert) surveys and pocket penetration tests to assess high-resolution pedostratigraphic records. bracone et al. 153 pleistocene paleosols of italy: ... 154 tion of a loess-paleosol sequence on top of monte netto (brescia, lombardy region), which is one of the isolated hills of tectonic origin in the middle of the po plain (desio, 1965). their multidisciplinary investigation of paleosols allowed the reconstruction of the complex evolution of the hill and the identification of the tempo and mode of pleistocene structural deformation of the area and related seismic hazard. the same approach was applied to reconstruct the tectonic evolution of the monferrato hills in piedmont (frigerio et al., 2017). zuffetti et al. (2018) explored how relicts of eroded and reworked paleosols, occurring systematically in colluvial wedges close to the main faults and/or at the erosive bottom of paleovalleys, mark phases of tectonicallydriven landscape instability triggered by late pleistocene uplift and faulting, along with valley incision and drainage network diversion in a hilly sector of the po river plain (lombardy region, northern italy). aucelli et al. (2011) used paleosols as auxiliary tools to acquire morphostratigraphic and chronological constraints for the assessment of the geomorphological and tectonic evolution of quaternary paleosurfaces in the molise apennine (southern italy), the genesis of which can be related to long-lasting periods of major tectonic stability alternating with episodes of uplift. many of the aforementioned papers clearly showed that pedoand chronostratigraphic correlations obviously benefited from varying dating techniques, such as radiocarbon, 40k/40ar and 39ar/40ar, electron-spin resonance (esr) and optically stimulated luminescence (osl), according to the available materials and the time ranges investigated. despite the wide application of paleosols in reconstructing quaternary environments and dynamics, their classification remains matter of discussion (zerboni et al., 2015). in fact, many authors suggest that, due to their variability and the current soil nomenclature codes, paleosols can hardly be classified with accuracy without introducing specific pedologic parameters of classification (james et al., 1998; nettleton et al., 1998, 2000; krasilnikov & garcía calderón, 2006). the classification of paeolsols thus requires the identification of those key attributes in modern soils that have preservation potential following burial, diagenesis, deformative, and erosion events. unfortunately, most of the key soil attributes have a low probability of being preserved without major modification or destruction (james et al., 1998; zerboni et al. 2011). in such contexts, it is preferable to find analogies between the described paleosols (or at least their remaining b horizons, zerboni et al., 2011) and modern soils categories defined by the international nomenclature (iuss working group wrb, 2022. 3. soil age and chronosequences soil chronosequences provide insight into the rates of soil-forming processes under defined combinations of climate, vegetation, parent material, and relief (sauer, 2015). over the last four decades, soil chronosequences have been studied all along the italian peninsula and in sicily. in the very northwest of italy, in the piedmont region, three studies on soil chronosequences formed in several series of pleistocene river terraces were reported in the 1980s. arduino et al. (1984, 1986) investigated redness rating according to torrent et al. (1980), pedogenic iron ratios and clay mineralogical composition of soils formed in pleistocene river terraces around and northeast of torino, in between the rivers elvo and cervo. they found that redness, fed/fet × 100 and (fedfeo)/fet × 100 were closely related to terrace age. clay mineralogical composition was dominated by 2:1 clay minerals in soils on the younger terraces; kaolinite and gibbsite were identified only in a soil on the oldest terrace. only a short time later, ajmone marsan et al. (1988) studied soils on three pleistocene river terraces about 90 km northeast of torino, estimated to 10-50 ka bp, 90-130 ka bp, and 500-750 ka bp. all soils showed clay illuviation, whereby the bt horizons of the two younger soils had brown colors (10yr6/6 and 10yr6/8), whereas the bt horizons of the oldest soil were more reddish (7.5yr5/6). horizon thickness and clay contents increased with soil age. the ratio (fed-feo)/fet × 100 increased, while that of feo/fed × 100 decreased with soil age. in the emilia-romagna region, eppes et al. (2008) studied a soil chronosequence consisting of 19 soil profiles formed in late pleistocene to holocene fluvial terraces in the reno river valley near bologna. they found consistently progressing differentiation of soil profile horizonation, particularly for soils on the holocene and late würmian (ca. 12 ka) river terraces, whereas older soils reflected a more complex development affected by climatic changes, including periods of stronger carbonate leaching, and of variable input of calcareous dust and/or colluvium. soils <2 ka were cumulic soils with weakly developed bw horizons and no evidence of carbonate redistribution. soils developed in about 5.46 ka old deposits showed a well-developed bw horizon and weak carbonate accumulation below, in the form of filaments and minimal coatings on the bottom of clasts. soils on about 12.5 ka old terrace bodies had bt horizons with well-developed clay films, underlain by bk horizons with 2-5 cm thick carbonate pendants on clast bottoms. in the montagnola senese mountain range in tuscany, costantini et al. (2002a, b) and costantini & damiani (2004) investigated early, middle to late pleistocene and holocene soils developed in acid rock and siliceous slope and alluvial deposits. with increasing soil age, they observed decreasing silt/clay ratios, decreasing cation exchange capacity of clay, increasing proportions of vermiculite and kaolinite in the clay mineral composition, as well as increasing fet and fed contents. also, contents of other elements, particularly those of cr, pb, and zn, increased with soil age. magaldi & tallini (2000) proposed a quantitative micromorphological index (misodi) to assess the degree of weathering and pedogenesis of relict paleosols. their aim was to provide a tool for extracting improved chronostratigraphic information from relict paleosols, in order to correlate them with ancient landforms, and thus contribute to the reconstruction of quaternary landscape development based on pedostratigraphic successions. they tested this index on b horizons of relict paleosols in the l’aquila-scoppito basin, within the abruzzo region, central italy, for which chronostratigraphic information was available. the index, which is based on microstructure, b fabric, thickness and abundance of coatings and nodules, and degree of alteration of mineral grains, showed scarciglia f. et al. an overall increase with soil age, amounting to 0 to 12 for holocene relict paleosols, 7 to 17 for late pleistocene relict paleosols, and 14 to 22 for middle pleistocene relict paleosols. in the molise region in the southern central apennines, van otterloo & sevink (2021) observed a soil chronosequence in the upper volturno basin, ranging from fluvisols in holocene sediments of the volturno river and tributaries, to chromic luvisols in late pleistocene river terraces, and highly weathered, deeply developed chromic luvisols and nitisols with reddish argic horizons formed in early middle pleistocene fluvio-lacustrine sediments. along the tyrrhenian coast of northern calabria, scarciglia et al. (2006) studied two soil chronosequences on early to late pleistocene marine terraces, in between the noce river in the north and the lao river in the south. the age of the i order terraces (the oldest ones, at 100-130/140 m a.s.l.) is assumed to be 0.8-1.3 ma. the ii order terraces (at 50-65 m a.s.l.) are estimated to 0.8-0.65 ma, the iii order terraces (at 30-45 m a.s.l.) to 0.6-0.5 ma, the iv order terraces have been dated to 250 >350 ka by u series dating of corals, pointing to their formation during mis 7-9. the mis 5 sea-level highstand created no comparable extensive terrace, but only a small wave-cut platform in this area. each of the two soil chronosequences (a northern and a southern one) included four soil profiles. all soils had intensely rubified, clayey argic horizons with strongly developed blocky to prismatic structure and common to very abundant clay coatings on ped surfaces. particularly the older soils showed ironmanganese mottles, coatings and concretions in their deeper argic horizons. the youngest soils (on the mis 7 -9 terraces) show carbonate accumulation at some depth. the redness rating according to torrent et al. (1980) yielded higher values for the northern chronosequence compared to the southern one, without showing any age trend. the clay-mineralogical composition of all soils was dominated by kaolinite and illite. ratios of (fed -feo)/fet and fed/fet tended to be higher in soils on the i and ii order terraces, compared to the iii and iv order terraces, however, without exhibiting a strong relationship with terrace age. along the ionian coast of basilicata, sauer et al. (2010) studied a soil chronosequence on a staircase of marine terraces in an area framed by the rivers basento in the north and cavone in the south. twelve soil profiles were investigated across the terrace 155 fig. 3 late pleistocene marine terrace t2 exposed in a gravel quarry about 8 km southwest of metaponto, at the ionian coast of basilicata. fig. 4 chromic luvisol developed in terrace t2 near metaponto, attributed to mis 5c. pleistocene paleosols of italy: ... 156 staircase between lido di metaponto, located on holocene alluvial deposits (terrace t0), and pisticci, located on the oldest terrace body that accumulated already during the brunhes epoch (terrace t10). the terraces (fig. 3) were attributed to mis 1, 5a, 5c, 5e, 7, 9, 11, 13, 15, 17, and 19, respectively. later, the number of soil profiles was increased to 22 profiles (sauer et al., 2015). soils developed towards chromic luvisols and alisols (fig. 4), whereby clay/silt ratios tended to increase with soil age. the increase in the fed/fet ratio with soil age could be best described by a logarithmic function. the authors used the weathering index based on the molar element ratio of (ca+mg+k+na)/al (excluding ca in calcium carbonate), wimer (sauer, 2017), to trace progressive silicate weathering and leaching of the released base cations. the wimer showed a logarithmic decrease with soil age. soil thickness increased over the first ca. 400 ka, while erosion prevented a further increase in soil thickness thereafter. this trend could be best described by a logarithmic equation. however, soil thickness increase was probably not continuous but took place only during interglacial periods, whereas pedogenesis under drier, more continental conditions and a corresponding forest-steppe landscape during glacial periods affected only the upper parts of the already deeply developed interglacial soils (sauer, 2015). corresponding steppe soils have been found embedded within last-glacial alluvial fans in calabria (fig. 5 in sauer, 2010). robustelli et al. (2009) investigated a soil chronosequence at the ionian coast of northern calabria, on five stacked river terraces along the rivers colognati and coserie, that are running next to each other into the ionian sea. the oldest terrace t1, which was attributed to mis 11-9, is at 218-154 m a.s.l., the second oldest terrace t2, which accumulated during mis 7, reaches an elevation of 120 m a.s.l., and the three youngest terraces t3, t4, and t5, which were attributed to mis 5e, mis 5c, and mis 5a, are at about 80 m, 60 m, and 45 m a.s.l., respectively. all soils had well-developed reddish argic horizons with clay coatings on ped surfaces and fe-mn concentrations. redness rating according to torrent et al. (1980) was highest in the soils on the oldest terrace. also, the ratio (fed-feo)/fet (arduino et al., 1984) was highest in the soils on the oldest terrace and highly variable in the soils on the younger terraces. the weighted chemical index of alteration (cia) by nesbitt & young (1982) was high in all profiles, ranging between 0.8 and 0.95. later, scarciglia et al. (2015) also compared this soil chronosequence to the two soil chronosequences that had earlier been investigated by scarciglia et al. (2006) along the tyrrhenian coast of calabria and proved the efficiency of weighting pedogenic iron indices on the basis of single horizon and total soil profile thicknesses to minimize the effects of soil truncation by erosion. wagner et al. (2007) analyzed a soil chronosequence on a series of five middle pleistocene marine terraces around menfi in western sicily, ca. 50 km east of marsala. all soils were chromic luvisols having well-developed argic horizons with blocky to prismatic structure and clay films coating the ped surfaces. the oldest soil had ferric properties at some depth. soil thickness increased with soil age. the clay mineral composition included a mixture of illite, smectite, and kaolinite in all soils. fed/fet ratios generally ranged between 0.5 and 0.6; only the oldest soil had fed/fet ratios of 0.730.88. as time is crucial in the formation, development and preservation of soils, it is noteworthy reporting on the concept of vetusol proposed by cremaschi (1987) after reconsidering the paleosols formed in the po plain since the beginning of the pleistocene. cremaschi investigated many pedostratigraphic sequences distributed in the region including paleosols embedded in complex sedimentary sequences, remains of dismantled paleosols, and soil bodies at the ground surface. the latter category includes several highly developed red paleosols, traditionally called ferretto soil (billard & orombelli, 1986), which can be classified as a sol fersiallitique (following duchafour, 1983) or oxisol, meaning a soil with huge kaolinite neogenesis, decarbonation, clay and fe translocation, and development of red color (see also section 4.1). comaparing the soil forming processes required for the development of such soils and the soils formed under interglacial conditions in the pleistocene, cremaschi (1987) concluded that the ferretto soil is not the result of a single pedogenic event under warm and humid conditions during a single time window of the pleistocene. conversely, its formation presumably started at the end of the early pleistocene and never stopped until today. such soil is the product of continuous pedogenesis occurred on stable surfaces under mediterranean climatic conditions. glacial conditions only slowed down the process. moreover, erosion only limitedly removed the topsoil and windblown sediments never buried the ferretto because thin sedimentary layers were involved into the pedogenesis. 4. paleosol genesis, paleoenvironmental and paleoclimatic reconstructions 4.1. rubified, clay illuviated paleosols among major distinctive features of pleistocene paleosols across the italian territory is the common coexistence of rubification (i.e. a diffuse matrix reddening caused by intense fe staining due to the high pigmenting power of hematite among iron-oxyhydroxides; torrent et al., 1980, 1983), extensive in situ clay neogenesis, and abundant illuvial clay coatings/infillings forming one or more bt (argic) horizons (fig. 5). such types of paleosols largely represent acrisols, alisols and luvisols (iuss working group wrb, 2022) or alfisols (usda soil taxonomy; soil survey staff, 2014) and fall within the so-called terrae rossae, terra rossa or red mediterranean soils (fig. 6). several researchers have interpreted the above cited set of features (especially the pair rubification-clay illuviation) as developed under warm/temperate and humid, seasonally contrasted climatic conditions, diagnostic of pleistocene interglacial periods, both in italian sites (carboni et al., 2006; coltorti & pieruccini, 2006; scarciglia et al., 2006, 2009, 2011; robustelli et al., 2009; bracone et al., 2012; di celma et al., 2015) and in other circum-mediterranean (fedoroff, 1997; cremaschi & trombino, 1998b) and mid-latitude environments scarciglia f. et al. (catt, 1989; bronger & sedov, 2003). high moisture availability and seasonality promoted water infiltration and downprofile migration of clay-enriched water suspensions, followed by capillary water rise and evaporation, leading to water deficit and stacking of clay particles in the soil macro/micropores. also, water uptake by plant roots and evapotranspiration could have contributed to their emplacement, especially under a stable and dense (forest) vegetation cover. recurrent cycles of clay illuviation often lead to (polycyclic) microlaminated/ crescent coatings/infillings, in some cases distinguishable in more than one generation based on changes in color and/or texture (fig. 7). multiple generations of orange to yellow, limpid to dusty clay coatings were detected also in loesspaleosols sequence from the po plain and formed during mis 4 to 3, thus suggesting that interstadials occurred during cold phases were warm enough to break (or slow) wind sedimentation and allow the onset of soil forming processes (zerboni et al., 2015). the same pedoclimatic conditions are suitable to chemical weathering processes affecting primary rock components and neogenesis of clay minerals. in particular, they could have favored an intense iron staining responsible of rubification, with iron released from fe-bearing primary minerals as the mobile fe2+, followed by its precipitation as fe3+ in neoformed oxyhydroxides (schwertmann & taylor, 1989; huang & wang, 1997). such conditions 157 fig. 5 truncated reddish paleosol in the trionto river basin (calabria) showing the upper argic horizon exposed at the ground surface in response to severe erosion (a). a subangular blocky aggregate partly covered by dark brown clay coatings of illuvial origin (b) from marine sands in the pizzo calabro area (calabria). fig. 6 examples of typical pleistocene red mediterranean soils in tuscany (valdelsa basin) (a) and calabria (vrica site) (b). their substrates consist of lacustrine limestone shaped by karst dissolution (a) and terraced marine marly clays affected by concentrated water erosion and badlands (b). pleistocene paleosols of italy: ... 158 may lead to the development of other common pedofeatures of this and other types of paleosols, such as reddish-brown/yellow to blackish fe-mn mottles, coatings, soft concentrations and concretions (fig. 8) (scarciglia et al. 2003a, 2006; coltorti & pieruccini, 2006; robustelli et al., 2009; di celma et al., 2015; cremaschi et al., 2015; boretto et al., 2017). among these, rounded nodules, which often exhibit a typical concentric internal fabric identified in thin section under an optical microscope, are common. this layered pattern testifies to a progressive outward growth from an initial accumulation of iron and manganese oxides around an inner “nucleus”. fe and mn contents vary largely across the accretionary layering (white and dixon, 1996; liu et al., 2002; scarciglia et al. 2003a). the nodules may display redder fe-rich alternating with blackish mn-rich layers, in response to cyclical changes in moisture availability from humid to dry soil state and slightly changing redox conditions (taylor et al., 1964; mckenzie, 1989). worth mentioning is that the intense tectonic activity, coupled with glacio-eustatic sea-level oscillations during the pleistocene, in places led to the burial of paleosols, obviously developed under exposed continental conditions, by marine sediments emplaced during a transgressive depositional cycle (fig. 8a). it is the case of a middle pleistocene paleosol in the cilento area (campania region, southern italy). it formed from aeolian deposits, was partially truncated and covered by 4-6 m of younger biocalcarenites reaching an altitude of about 35 m a.s.l., although nowadays it is not located along the coastline (scarciglia et al., 2003a, b). its burial modified the geochemistry of the pedogenic matrix, leading to a strong increase of sodium in the exchangeable complex despite its high solubility and mobility in the pedoenvironment, and especially to chlorine trapping in the iron-rich layers of the concentric nodules, as nicely shown in sem-eds (scanning electron microscopy coupled with energy dispersive x-ray spectrometry) compositional maps (fig. 8c). based on size, shape, outer rim outline and geometric relationships with the surrounding groundmass observed in thin sections, some case studies found that not always fe-mn nodules formed in situ (anorthic), but were eroded and redeposited from other adjacent paleosols, sometimes coexisting with in situ nodules (cremaschi et al., 2015; di celma et al., 2015; boretto et al., 2017; frigerio et al., 2017). fig. 7 microphotographs of clay coatings observed in thin sections in plane polarized light (a, c) and crossed polarized light (b, d). smooth-banded to grainy extinction patterns observed between crossed polarizers and cracks indicate their relict significance. photos are from argic horizons developed on terraced fluvial gravel deposits including plutonic, metamorphic and sedimentary rock clasts in ne calabria (trionto river catchment) (a, b) and on detrital metarenite slope deposits in se sardinia (s’acqua callenti stream catchment) (c, d). in c and d a laminated clay infilling exhibits an alternation of silt and silty-clay coatings. scarciglia f. et al. both rubification and clay illuviation appear to be relict features. actually, (late) glacial and holocene (interglacial-like) soils do not display extensive red but rather (yellowish-)brown colors, and illuvial clay coatings have been usually attributed to glacial interstadials (with relatively milder climatic conditions than stadials), and/or to the late early to middle holocene climatic optimum (sensu rossignol-strick, 1999), while scarcely present in roman soils (scarciglia et al., 2008; aucelli et al., 2011; pelle et al., 2013; zucca et al., 2014a; boretto et al., 2017). similarly, based on pollen records from a karst cave in apulia (se italy), russo ermolli et al. (2022) constrained reddish paleosols to the last interglacial, during which olea was widespread in the mediterranean area, and ascribed the overlying brownish soils to the lateglacial, characterized by open, steppedominated environments with rare tree and shrub species. these finding are consistent with a comparison of soil-chronosequences from mediterranean areas in europe and california, which showed that matrix rubification can be found in soils >100,000 years (sauer, 2010). also, fedoroff (1997) suggested that clay illuviation in red soils can only occur at present in humid/sub-humid margins of the mediterranean basin. based on these considerations, the italian paleosols exhibiting the aforementioned features might have formed even under warmer and/or more humid climate conditions (tropical/ subtropical) than modern (pre-industrial) times, able to enhance seasonal contrast and the speed/intensity of process response. this is in line with global-scale paleotemperature and stable isotope records (lisiecki & raymo, 2005; hoffman et al., 2017) and paleoclimatic proxies from italian marine and coastal environments, where pleistocene interglacials (and the last interglacial in particular) are marked by higher sea-level stands and appearance of typical warm-water “senegalese” fauna (e.g., persististrombus latus, cladocora coespitosa, globigerinoides ruber) (capraro et al., 2005; ferranti et al., 2006; amorosi et al., 2014a; cerrone et al., 2021). the relict nature of the clay coatings in many italian paleosols dating to the pleistocene is proved by the frequent identification of post-emplacement degeneration/disruption features under the optical microscope in thin sections (fig. 7) (scarciglia et al., 2003a, b, 2006, 2009, 2011; coltorti & pieruccini, 2006). the main micromorphological evidence of their now inactive formation processes can be the one or more of the following: (1) smooth-banded to grainy extinction patterns observed between crossed polarizers, due to loss of the initial anisotropy (conversely showing sharp extinction bands derived from the parallel settlement of platy clay particles during illuviation onto pore surfaces); (2), fragmentation; (3) cross-cutting by subsequent pedofeatures; (4) deformation; (5) progressive disappearance 159 fig. 8 partially truncated middle pleistocene paleosol buried by marine bioclastic arenites in the mt. licosa promontory (cilento, campania) (a). microphotograph of massive and concentric fe-mn nodules in the same paleosol (b) and corresponding eds compositional maps of mn (green), fe (blue) and cl (red) (c). pleistocene paleosols of italy: ... and assimilation into the surrounding pedogenic matrix; (6) (sub)rounded clayey papules (sensu brewer, 1976) or pedorelicts (fig. 9a), indicative of soil reworking processes. the spatial rearrangement of clay coatings and their internal fabric can be a result of shrink-swell (vertic) dynamics (argilloturbation), cryogenic processes triggered by freeze-thaw cycles, bioturbation by soil fauna or plant roots (bronger, 1969/70; brewer, 1976; catt, 1989; fitzpatrick, 1984, kemp, 1998; verrecchia & trombino, 2021, david badía-villas et al., 2022). based on the very diagnostic set of macroand micromorphological features mentioned above, some researchers have tentatively used the red clay-illuviated paleosols (from north to south italy) as rough indicators of possible pleistocene interglacial-like climates, even when neither radiometric dating nor well-constrained chronostratigraphic information were available (e.g., magaldi & tallini, 2000; cottignoli et al., 2002; trombino & ferraro, 2002; d’amico et al., 2016). other interesting micromorphological features described in such types of italian paleosols across peninsular and insular italy are linear, crossed, curved or irregular anisotropic domains (speckled and striated bfabric), observed in thin section under crossed polarized light (fig. 9b) (cremaschi & van-vliet lanoë, 1990; coltorti & pieruccini, 2006; scarciglia et al., 2006, 2011). they point to varying extents of iso-orientation of phyllosilicate clay platelets along cracks delimiting aggregates, around rock clasts, nodules, rounded pores or within the pedogenic matrix. they formed in response to cyclical shrink-and-swell dynamics of clay-bearing materials in turn caused by alternating soil desiccation/ imbibition (vertic properties). this is consistent with cyclical changes in moisture, which also promoted clay translocation, iron-oxide staining and rubification. in places, the same authors found field evidence of this process in slickensides and/or shiny faces, although such features also occur in non-rubified soils and paleosols (e.g., aucelli et al., 2011; colombo et al., 2016). worthy of note are two innovative papers by scarciglia et al. (2009, 2011), which for the first time applied laser ablation inductively coupled plasma mass spectrometry (la-icp-ms) to thin sections, associated with traditional micromorphological (optical and scanning electron microscopy) techniques, to investigate soil genesis in some pedons of se sardinia including a paleosol (luvisol). among the main results is the detection of a trend of increase in the contents of some trace elements, including rare earth elements (rees), from the parent rock skeletal grains to the pedogenic matrix up to the illuvial clay coatings of the bt horizons. this behavior highlights that element mobilization and fractionation was clearly controlled by pedogenesis, with trace elements released from the weathering of primary minerals, concentrated through illuviation processes and adsorption onto negatively charged surfaces of clay minerals (and iron oxyhydroxides) thanks to their cation exchange capacity. 4.2. paleosols with secondary carbonate accumulation case studies from several sites of italy showed that commonly observed in pleistocene paleosols formed on limestone/dolostone and other caco3bearing parent materials is decarbonation or decalcification (loss of carbonates by leaching), often coupled with recarbonation of deeper horizons. secondary carbonate accumulation occurs in the form of soft concentrations, nodules or indurated concretions (sometimes including rhizoliths or impregnating the whole horizon) into bk (calcic) and bkm (petrocalcic) horizons (fig. 10a) (carboni et al., 2006; coltorti & pieruccini, 2006; scarciglia et al., 2006; sauer et al., 2010; bracone et al., 2012; di celma et al., 2015). the specificity and diffusion of such features is traditionally acknowledged in the popular culture and buried calcic soil horizons are often defined with proper names, as the abovementioned caranto in the veneto region (donnici et al., 2011) or the crusta and tufina in the apulia region (magaldi, 1983; carnicelli et al., 1989; magaldi & giammatteo, 2008; mariani et al., 2020). the latter terms refer to a petrocalcic soil horizon (calcrete) 160 fig. 9 microphotographs of: rounded iron-stained pedorelict reworked into a pedogenic matrix of a middle pleistocene paleosol showing different color, fabric and skeletal grain size (trionto river catchment, calabria) (a); moderately anisotropic matrix showing parallel and crossed anisotropic domains in an argic horizon formed on an early middle pleistocene marine terrace (north tyrrhenian sea coast of calabria, torre dino site) (b). both frames are in crossed polarized light. scarciglia f. et al. formed in the late pleistocene or early holocene onto pleistocene fluvial sediments related to the uplift of the southern apennines. caco3 redistribution often occurs in reddish, clay-illuviated paleosols as well. carbonate leaching is often assumed to necessarily occur before clay illuviation to allow dispersion of clay particles (inhibited by high amounts of ca2+ and other divalent ions) and their translocation downprofile (quènard et al., 2011). however, some case studies on soil chronosequences in south italy demonstrated that clay illuviation occurred even in paleosols where soil carbonates are occasionally still present and ph values are not always acidic (scarciglia et al., 2006; robustelli et al., 2009; sauer et al., 2010). this evidence suggests that na+ content in the exchangeable complex might have played a major role as driver of clay dispersivity and mobilization in respect of anti-dispersive (flocculating) ca2+ (or mg2+) ions. nonetheless, a relative low amount of the divalent cations is not always sufficient to hamper completely the dispersal of clay particles, based on ph values and types of clay minerals. in addition, a climate change towards more seasonally contrasted and possibly overall drier conditions might have favored carbonate dynamics after clay mobilization. such a seasonality might have controlled carbonate dissolution and leaching first, followed by marked water deficit for its reprecipitation. a suitable soil environment could be tentatively related to climate shifts occurred during the same interglacials (e.g., zucca et al., 2014b) or rather during intervening glacial stages (aucelli et al., 2011). the latter interpretation is consistent with the cyclical alternation of pleistocene carbonate-enriched layers and reddish iron-stained paleosols observed at low latitudes. this feature is interpreted as a response to cyclical changes from dry to wet climatic conditions (scarciglia et al., 2018), and agrees with the main glacial/interglacial cycles recorded in the δ18o isotopic signature at high latitudes (tiedemann et al., 1994). pollen data collected across the entire italian peninsula show a typical alternation of artemisia-dominated or wooded steppes and mesophilic/thermophilic forest cover as a proxy of the vegetation changes occurred during the pleistocene from overall warm/temperate and humid interglacials to cold/dry glacials respectively, although more complex patterns can be found locally (bertini, 2010; bertini et al., 2015). the works of boretto et al. (2017) and zanchetta et al. (2017) on stable isotopes from pedogenic carbonates and terrestrial mollusk shells found in a middle pleistocene paleosol and a late pleistocene loess developed during glacial periods (mis 14 and mis 2) in central italy, support these findings. values of δ13c and δ18o clearly evidence drier climate conditions, with a sparse c3-dominated vegetation cover and temperature on average 3-5 °c lower than present. based on these considerations, where bk horizons are observed at shallower depth, drier (semiarid) climate could be invoked (unless severe erosion has rejuvenated the paleosol profile), whereas subhumid conditions could have favored deeper pedogenic carbonate accumulation (cf. retallack, 2005). 4.3. paleosols developed under cold climatic conditions according to fedoroff (1997), red mediterranean paleosols developed during pleistocene interglacials, often experienced other geomorphic and pedogenic processes during intervening glacial periods. they were affected by erosion (truncation), colluviation, aggradation/burial by wind-transported dust (often providing allochthonous carbonate input with subsequent lea 161 fig. 10 thick petrocalcic horizon of late pleistocene age with composite laminar fabric in a fluviokarstic valley close to altamura town (apulia region) (a). laminar and lenticular structures in a buried palaeosol developed on calcschist and serpentinite fluvial gravels and sands located downslope of mt. beigua in liguria (photo courtesy of i. rellini) (b). pleistocene paleosols of italy: ... ching/precipitation; see section 4.2) and/or local water logging (likely caused by wet conditions in response to slow seasonal ice thawing or prolonged melt during interstadials and partially impeded drainage). from northern to southern italy, many researchers described soil features that clearly indicate the imprint of such a range of morphodynamic processes, also affecting other soil types (cremaschi & van-vliet lanoë, 1990; coltorti & pieruccini, 2006; scarciglia et al., 2003b, 2015). there are many other morphological properties, observed at both field and microscale, attributed to pleistocene glacial phases and considered diagnostic of seasonal soil freezing and thawing (periglacial conditions). these are platy, laminar, lenticular (fig. 10b) or cuboid pedogenic structures, sand wedges and ice wedge casts, banded (micro)fabric (fig. 11a), vesicular pores, cryoturbation (fig. 11b) and rock clast orientation, in situ frost shattering of rocks, granulation or ped disaggregation, silt illuviation in the form of typical silt cappings (or caps), silt coatings/infillings (fig. 7c, d) and sand coatings, degeneration/disruption of former illuvial clay coatings (catt, 1989; fitzpatrick, 1997; van vliet-lanoë, 1998; van vliet-lanoë & fox, 2018), discussed as follows. cremaschi & van-vliet lanoë (1990) and rellini et al. (2014) identified various horizontally elongated pedogenic structures in northern italian paleosols of different pleistocene ages located from liguria to lombardy even at low (non-mountain) altitudes on terraces, moraines, loess deposits and rock shelter fills at the margin of the po plain. platy and foliated structures are typical features caused by seasonal ice segregation (freeze-thaw cycles) in the form of lenses or veins within fissures formed by cryodesiccation in response to a progressive propagation of soil cooling from the surface downwards (van vliet-lanoë, 1998). in places, they may exhibit a banded fabric with internal textural changes (fig. 11a) (kemp, 1999). also, cubic structures formed by reticulate segregation patterns of ice were described from the ligurian alps (rellini et al., 2014) to southern tyrrhenian coastal sites (scarciglia et al., 2003a, b), along with redoximorphic features and bleached tongues/zones, supposed to form under conditions of water stagnation or severely hampered drainage, enhanced by seasonal ice and snow melting. scarciglia et al. (2003a, b) identified also vesicular pores, imprinted from air bubbles trapped during soil freezing, silt caps on skeletal grains and silt coatings in pores, derived from freeze-thaw cycles, in turn promoting aggregate disruption and granulation (see also cremaschi & van-vliet lanoë, 1990; rellini et al., 2009), followed by melt water-driven migration of coarse particles downprofile. degeneration features of clay coatings illuviated during pleistocene interglacials (see section 4.1) were attributed to subsequent soil freezing and thawing under periglacial conditions. although each of these pedogenic features has not always an univocal genesis, the coexistence of all of them in the same paleosols, coupled with other diagnostic geomorphological features observed in the study areas, support a past periglacial environment where (seasonal) frost action was prominent. this hypothesis is corroborated by the genesis of surface microrelief enhanced by frost action in swelling clay soils during the last glaciation, as well as by clear evidence of in situ frost shattering of cryogenic breccia (slope deposits) and a humanmade flint artifact (cremaschi & van-vliet lanoë, 1990). in line with these finding, d’amico et al. (2016, 2019) identified silt-illuviated horizons, lateral variations of coarse and fine particles, irregular depth patterns of organic matter, wedge casts and convoluted laminar microstructure in paleosols close to fossil periglacial landforms (blockfields/blockstreams, patterned ground and solifluction sheets) at elevations ≥600 m a.s.l. in the ligurian alps of piedmont (nw italy). all these features were explained by past cryoturbation and sorting during pleistocene glacial periods. also, typical stratified slope deposits (e.g., coltorti & dramis, 1988), emplaced by rockfalls and/or slope wash dynamics (robustelli et al., 2005b), alternated to reddish (sometimes reworked) interglacial paleosols even in coastal zones of southern italy (esposito et al., 2003; cottignoli et al., 2005; scarciglia et al., 2006), support the past occurrence of peri 162 fig. 11 microphotographs of: banded fabric developed in a weathered pyroclastic layer of late pleistocene age (agnano p.p. eruption, ~12 ka bp) sourced from the phlegrean fields in the vesuvius piedmont, in campania (photo courtesy of v. zumpano) (a); cryoturbated silt and clay coatings and numerous vesicular pores in a luvisol in the western po river plain, in lombardy (b). both frames are in plane polarized light. scarciglia f. et al. glacial conditions during pleistocene glacial stages (chelli et al., 2006). these led to cryoclastic and other cryonival processes, alternated and/or overprinted by varying surface dynamics and pedogenesis under milder conditions. similarly, the main cryogenic features described by rellini et al. (2014), located close to typical blockfields and blockstreams (firpo et al., 2005, 2006), support the action of frost weathering (e.g., ballantyne, 2010) and a combination of solifluction, gelifluction and/ or frost creep, related to past glacial conditions and possibly a discontinuous permafrost. a recent work of pintaldi et al. (2021) revealed the occurrence of welldeveloped paleosols hidden under the stony cover of periglacial blockstreams and blockfields in the nw italian alps, that likely record the major climatic changes and amelioration started since the end of the last glacial maximum (lgm). in addition, the occurrence of reworked loess material on top of a polygenetic paleosol profile in the ligurian alps, displaying evidence of repeated phases of erosion and deposition, is consistent with an extension of windblown dust sedimentation during late pleistocene cold dry stages in the north italian region between the alps and the mediterranean (rellini et al., 2014). based on some of the aforementioned micropedological features (granular, platy, subangular blocky microstructures and silt cappings on coarse mineral grains), created by gelifluction and ice lensing, along with relative soil chronology obtained by comparing crystallinity ratios of free fe oxides, and the analysis of paleoprecipitation/temperature derived from various proxies, longhi et al. (2021) reconstructed late pleistocene (and holocene) podzolization phases and permafrost aggradation, the latter lowered more than 300 m than today, in the central italian alps. to the last glacial period are referred a variety of soil morphological, micromorphological and sedimentological properties observed in two paleosols of mountain sites in the sila massif (calabria), such as a sand wedge and an ice wedge cast, silt veins and lenses, reticulate silt veins and matrix lenses (dimase, 2006). these features were interpreted as cryogenic and indicative of a periglacial environment possibly with former permafrost, and are in line with possible cirque landforms and moraine deposits reported by boenzi & palementola (1974, 1975) in close sites of the same massif. ice wedge casts and other (microand macro-) pedofeatures related to the occurrence of permafrost were identified in loessic soils from northern italy (cremaschi, 1990; zerboni et al., 2015, 2018; negri et al., 2021), indicating the occurrence of phases of periglacial conditions at least at the northern margin of the po plain during the late pleistocene. ice wedge casts are good indicators of past permafrost conditions, but they are less common in the italian loess record than in other loess basins of europe, likely suggesting relatively less severe climatic settings. 4.4. loess plaeosols and aeolian input during the pleistocene, wind sedimentation occurred in many parts of italy and triggered the formation of loess bodies and sand dunes, as much as the input of dust and volcanic material to soils (see also sections 2 and 4.6). windblown sediments underwent pedogenesis under warm (interglacial/interstadial) and cold (glacial/ stadial) phases, thus preserving information on past climate change. such soils were sometimes buried and are still preserved along complex pedosedimentary sequences, whereas elsewhere they were eroded or overprinted by holocene soil-forming processes (cremaschi, 1987). loess windblown silt is widespread along the italian peninsula and was recently classified into the 163 fig. 12 loess-palsosols sequences at monte netto (lombardy) (a) and ghiardo (emilia romagna) (a). in a a multiple sequence of middle to late pleistocene loess weathered into soil lays on top of a fluvial deposit. huge hydromorphic features and bc horizons (dark layers) formed in correspondence of the top of each buried soil. in b the stratigraphic sequence on the ghiardo plateau (cavriago site outcrop) exhibits the loess weathered into bt horizons and at its bottom a bc horizon is present, laying on a middle pleistocene clay-rich fluvial sediments (photo courtesy of m. cremaschi). pleistocene paleosols of italy: ... mediterranean loess domain of the loess landscapes of europe (lehmkuhl et al., 2021). in northern and central italy, loess is widely recorded along the margins of the po plain (fig. 12) and the coastline of the northern and eastern adriatic sea (cremaschi et al., 1990; cremaschi, 2004; boretto et al., 2017; costantini et al., 2018; badino et al., 2020). the main source for silt was the deflation of the middle/late pleistocene fluvioglacial and fluvial deposits at the southern margin of the alps and along the northern fringe of the apennines and the exposed marine shelves. a further source of loess along the southern adriatic and tyrrhenian shorelines were reworked tephra sediments (cremaschi & ferraro, 2007; hirniak et al., 2020). italian loess is also often overprinted by pedogenesis (costantini et al., 2018; zerboni et al., 2018) and a variety of soils are interbedded within loess sequences, including chernozems, alfisols, cambisols, and luvisols. occasionally, layers of reworked loess are also present. in many cases, polycyclic soils have been reported for loess sequences, suggesting the occurrence of subsequent pedogenic phases, marked by similar processes related to soil decarbonation, formation of iron oxides and clay translocation (fig. 13) (cremaschi, 1987; cremaschi & busacca, 1998; zerboni et al., 2015; negri et al., 2021). some studies also highlight the relative role played by time and climate in the formation of loessic soils (cremaschi & busacca, 1998). loessic soils commonly found along the northern fringe of the apennines display evidence of strong clay neoformation and translocation as much as huge decarbonatation occurred in the holocene (cremaschi et al., 2015). periglacial processes were also reported from several loess/paleosols sequences from northern italy. they are occasionally testified by the occurrence of pedofeatures related to soil freezing (e.g., ice lensing) (cremaschi et al., 1990, 2015; cremaschi & van vlietlanöe, 1990). the val sorda loess sequence, for instance, covers a truncated rubified soil dated to the last interglacial and includes at least three chernozem-type buried paleosols (ferraro, 2009), corresponding to phases of decreased wind sedimentation and accumulation of organics with low-rate of turnover in a steppe-like environment. at monte netto, several loessic soils are superimposed along a soil sequence formed since the middle pleistocene and displaying a progressive reduction in intensity of soil forming processes during each phase of pedogenesis (fig. 13a) (zerboni et al., 2015). at the same site, the rate of pedogenesis informs on the tectonic evolution of the area and the rate of vertical 164 fig. 13 microphotographs of: complex clay coatings in plane (a, c) and crossed polarized light (b) in a bt horizon developed in a loess sequence from the central po plain (monte netto, lombardy region); (d) a poorly weathered loess deposit from the central po plain (ghiardo site, in emilia romagna) affectd by hydromophism (formation of fe-mn-rich nodules and discoloration of the groundmass) observed in plane polarized light. in all frames, the groundmass shows a dominance of silt grains. scarciglia f. et al. uplift. loess sediments accumulated on top of karst regions or of limestone plateaus were affected by stronger pedogenesis and were almost completed digested into soils (trombino & ferraro, 2002; sauro et al., 2009; peresani & nicosia, 2015; d’amico et al., 2021). such evidence confirms that the paleopedological properties of italian loess records soil-forming processes occurred under different climatic conditions encompassing the glacial/interglacial phases of the middle and late pleistocene. costantini et al. (2018) suggested that the identification of loess contribution to soil formation can be detected based on selected pedological parameters (particle size distribution and sorting, pedostratigraphic position, shape of the grains observed under optical and scanning electron microscopes, soil micromorphological features). along the shorelines of italy, several pleistocene dunes deeply affected by pedogenesis can be found. some of them were interpreted as eolianites. along the shore of the elba island (tyrrhenian sea), late pleistocene calcareous eolianites were affected by deep redistribution of calcium carbonate due to pedogenesis. moreover, they display interlayered rubified soils that suggest the occurrence of phases of intense pedogenesis (cremaschi & trombino, 1998a; d’orefice et al., 2007). eolianites with interlayered rubified paleosols have been reported also from sardinia (coltorti et al., 2010). zucca et al. (2014a) report on a complex sequence formed by the interplay between pedogenesis and wind sedimentation along the coastline of sardinia, where a paleosol is buried by a coastal dune that experienced significant pedogenesis during the late pleistocene interstadials, before being buried by aeolian sand. the identification of aeolian inputs to soil formation is often difficult to assess, but several authors investigated pleistocene paleosols form italy and identified inputs from proximal or distal dust sources (costantini et al., 2018). the input of saharan dust is likely ubiquitous over europe, but its identification in ancient soils need a careful characterization of the geochemical fingerprint and of the mineral constituents of soil horizons. giraudi et al. (2013) identified the occurrence of hexogen quartz in soils from the mount matese in southern italy, associated to dust sedimentation sustained by late pleistocene phases of increased aridity and deflation over the sahara desert. andreucci et al. (2012) investigated a reworked paleosol from nw sardinia and using sem observation and xrd analyses identified the occurrence of abundant allochthonous dust that represents a saharan input to the island, which continued for large part of the late pleistocene. 4.5. fragipan, plinthite and petroplinthite-bearing paleosols other interesting field features described in pleistocene paleosols of italy are fragipans (fig. 14), plinthite and petroplinthite, all of which characterized by important enrichment in iron oxides and phyllosilicate clays. the genesis of fragipans is an actively debated and noteworthy issue, which still warrants strong research efforts to deepen in the understanding of the mechanisms responsible of their peculiar features. among the major hypotheses proposed in the literature, nicely summarized by bockheim & hartemink (2013), are the following: hydro-consolidation of wet soil material overloaded 165 fig. 14 paleosols exhibiting densely-packed horizons with hard consistence and fragic properties, which contributed to the development of glossic features, in places marking lenticular (a) or angular blocky to prismatic (b) structures. (a) montagnola senese, tuscany; (b) trionto river basin, calabria). pleistocene paleosols of italy: ... by younger heavy sediments upon wetting and drying; mechanical compaction and close-packing of soil particles, in cases promoted by shrink-swell cycles or ice growth and freeze-thaw cycles under relict periglacial conditions; the presence of lithologic discontinuities or paralithic/lithic contacts across soil profiles; seismic shaking and liquefaction; bonding by precipitated iron, aluminum, silica and/or clays. costantini & napoli (1996) studied in detail some fragipans and other closepacked horizons from different paleosols, developed during the pleistocene on alluvial and colluvial deposits derived from metamorphic rocks in the montagnola senese area, in tuscany. they showed silt-dominated textures, with alternatively high contents of sand or clay, overall hard consistence, high bulk and package density, poor hydraulic conductivity with prevalent micropores, varying extent of illuvial clay coatings/infillings often partially disrupted, high amounts of iron-oxides and free iron, redox depletion zones, no carbonate and poor contents of extractable silica. in the same region, certini et al. (2007) characterized some discontinuously distributed fragipans using field, physical, chemical, mineralogical, micromorphological analyses and radiocarbon dating, and argued that dewatering of past earthflow deposits could have led to consolidation of the soil material rather than other causes such as frost action. scalenghe et al. (2004) addressed similar hypotheses, pointing to the role of liquefaction of soil material caused by earthquakes, after performing experimental freeze-thaw cycles and vibrations of dry and water-saturated soil materials at different amplitude and time spans. ajmone marsan & torrent (1989) hypothesized the role of amorphous silica compounds associated with fe oxides (mostly goethite) as bonding agents in a paleosol with fragic properties developed on a river terrace of pleistocene age in nw italy, using citrate-bicarbonate-dithionite and acid oxalate extractions. other works on fragipans of italy are those of ajmone marsan et al. (1994) and falsone & bonifacio (2009) on such types of dense/indurated horizons in the piedmont region. they highlighted the role of soil porosity in terms of pore size distribution and spatial arrangement of coarse and fine particles, controlled by the nature of the parent materials and by pedogenic processes, applying physical analyses, hg intrusion porosimetry and/or image analysis of thin sections along with morphological observations. assallay et al. (1998) suggested the possibility of fragipan formation in loess soils after hydroconsolidation, and zerboni et al. (2015) detected fragic properties were in bt(x) soil horizons from the monte netto loess sequence. based on our experience, some transitional horizons that display reticulate, lenticular or tongued eluvial and fe-depleted patterns within feand clay-enriched matrix, such as ebt, bet, e/bt and b/et horizons (fig. 15) (scarciglia et al 2003a, b, 2015; robustelli et al., 2009) warrants attention, as occasionally observed in some paleosols of italy of middle pleistocene age. among these are some described by robustelli et al. (2009) in calabria, which were extremely hard to sample even using a geological hammer but slaked quickly after immersion in water, and might represent fragipans (ebtx, betx, e/btx and bx/et) to be investigated deeply, trying to assess their complex genesis. preliminary data suggest that they could have been derived from seasonal freezing and thawing during glacial stages, overprinted on mostly interglacial features. rellini et al. (2015) provide another case study on an indurated, petroplinthic horizon from a polygenetic paleosol, in the frame of a reconstruction of quaternary paleoenvironmental changes in a coastal pedosedimentary sequence from northwestern italy. by combining physico-chemical analyses, x-ray diffraction, micromorphological observations in thin section and scanning electron microscopy, the authors suggested that the hardening of petroplinthite derived from secondary feoxide enrichment due to intensely weathered, lateritic nodules reworked from an upslope, dismantled plinthite paleosol, which had previously undergone lateritization processes under different, tropical-like conditions. 4.6. volcanic paleosols given the long-lasting eruptive history of peninsular and insular italian volcanoes over the pleistocene (and the pliocene) (peccerillo, 2005), several strictly volcanic and peri-volcanic to distal environments appear poten 166 fig. 15 irregular to reticulate (a) and tongued (b) redox depletion zones surrounded by iron-oxide stained pedogenic matrix in two plaeosols developed on middle pleistocene fluvial and marine terraces from the tyrrhenian and ionian coasts of calabria, respectively. scarciglia f. et al. tially good natural archives where lava flows and/or fall deposits were spread and potentially led to associated soil formation. when the eruptive products can be dated by radiometric techniques or their provenance can be identified directly in the field or using geochemical tracers or minero-petrographic imprints, tephra reveal as very useful tools to fix time constraint to pedogenesis, achieve tephrostratigraphic correlations (see section 2) and allow paleoclimatic/environmental reconstructions at varying spatial and temporal scales. volcanic parent materials weathered to different extents, and in places mixed with different local substrates of non-volcanic origin, were widely identified in pleistocene pedostratigraphic successions across the italian territory. however, in many cases, the corresponding soil profiles and horizons did not exhibit typical features directly linked to the volcanic input (fig. 2b) (aucelli et al., 2011; colombo et al., 2016) or were not sufficiently characterized in terms of specific analytical techniques from such a diagnostic perspective (magaldi et al., 2009; peresani & nicosia, 2015; marinari et al., 2017; zuffetti et al., 2018; pereira et al., 2020). in some other cases, paleosols developed on tephra displayed distinct andic properties, typical of andisols/andosols (soil survey staff, 2014; iuss working group, 2015) and related to neoformed srom, i.e. short-range order (poorly crystalline) clay minerals (allophane, imogolite) and fe-hydroxide (ferrihydrite), or at least andic-like features despite belonging to other soil groups. frezzotti & narcisi (1996) identified a buried paleosol (pedomarker a) with andic properties, occasionally truncated, widespread in the central apennine chain. it developed on volcanic ashes sourced from the well-known campanian ignimbrite explosive eruption from the phlegrean fields (campania region), overlies carbonate outwash fan, alluvial and stratified slope deposits, and is sealed by similar types of clastic sediments and loess. the authors’ results indicate that this paleosol formed under temperate humid climatic conditions, likely occurred during the last interstadial oscillations of the pleniglacial, approximately between 39 and 30 ka. its development was interrupted by the early onset of colder and drier conditions of the last glacial maximum, which led to the emplacement of periglacial deposits, along with soil degradation, erosion and colluviation. de rosa et al. (2016) reported partly similar findings studying in detail the major pedogenic and syn-eruptive hydromagmatic emplacement features and processes of some brown tuffs, located on lipari island and widespread in the aeolian archipelago within a similar time span (ca. 40 to 27 ka). the poor development of andic properties is consistent with a prevalent dry climate during the last glacial period. nonetheless, some seasonal contrast between subhumid to dry conditions favored the neogenesis of phyllosilicate (crystalline) clay minerals, in particular the transformation of smectite (derived from the hydrothermal alteration of primary volcanic glass) to halloysite, rather than poorly crystalline clays (preferentially promoted under prolonged moisture availability). similarly, such conditions, likely occurred during milder glacial interstadials, were prone to the illuviation of clay coatings. the paper of mirabella et al. (2005) is in line with the absence of andic properties in other paleosols and soils of late pleistocene ages on the same island, which conversely displayed vitric and vertic features. in turn, egli et al. (2008) explored the relationships between time spans of pedogenesis and some soil properties in other pleistocene pedons on mt. etna volcano in ne sicily, where andic properties and short-range order minerals were identified, along with phyllosilicate clays, but also recorded a clear addition of younger volcanic ashes contributing to soil formation. still formed during the last glacial period are some buried paleosols located in the piedmont of mt. vesuvius volcano and the surrounding plain, overlain by holocene volcanic soils (scarciglia et al., 2014; vogel et al., 2016). based on the well-dated eruptions from the vesuvius and the phlegrean fields in the range of ca. 22 to 12 ka, along with detailed geochemical, mineralogical, micromorphological analyses and pedogenic fe indices, scarciglia et al. (2014) emphasized the role of time and climate in respect of the development of andic properties. predominant srom components were found in the pedogenic horizons corresponding to the early post-glacial amelioration and a milder interstadial of the lgm just predating the last pleniglacial culmination, during which climatic conditions were moister than the intermediate stadial and the subsequent lateglacial. conversely, in the paleosol horizons developed during proper glacial stages, phyllosilicate clay minerals prevailed thanks to drier and more seasonally contrasted environments. vacca et al. (2003) highlighted that in the roccamonfina volcano area (ca. 60 km nw of the vesuvius), allophanic and nonallophanic pleistocene soils coexist in similar landscapes under similar climatic conditions, probably as a response to different hydraulic properties of the parent material and different time ranges of pedogenesis. allophanic soils developed in younger, porous and permeable ash deposits, which favored a rapid weathering of glass fragments and consequent release and availability of al and si to enter the lattice of poorly crystalline clays. diversely, non-allophanic soils developed in older, less porous and less permeable scoria and consolidated tuffs, promoting the neoformation of crystalline clays (including halloysite) as a weathering product of volcanic glass. colombo et al. (2007) highlighted the prominent role of the duration of pedogenesis, along with climate, land use and human disturbance, for the varying degree of development of andic properties in volcanic paleosols of latium and campania which they considered more important than the role of parent materials with different mineralogical compositions. 5. some applications of paleosol studies 5.1. paleosol fertility and cultural value a relevant field of application of the paleosol knowledge in the italian peninsula regards fertility, especially in relation to the uniqueness and irreproducibility of paleosol features. costantini et al. (2012) investigated the main relationships between soil/paleosol properties, fertility, functional traits (soil texture, stoniness, root depth, bulk density, organic carbon, ph, cation exchange capacity, available water capacity, total carbonate, electrical conductivity, topography, pedoclimatic regime) and viticultural and oenological behavior, grape producti 167 pleistocene paleosols of italy: ... vity and organoleptic characteristics of a worldwide famous vintage wine in some vineyards of tuscany. pedological properties of pleistocene (and holocene) paleosols and corresponding vine varieties and quality changed remarkably even when developed on the same types of sediments, in response to unique natural geomorphological events and human impact on landscape shaping, in turn affecting the equilibrium between soil formation and erosion. therefore, such terroirs represent soil-climate-vineyard ecosystems that partly inherited their properties from past climatic/environmental conditions, but at the same time, they are intrinsically fragile and potentially prone to degradation. costantini et al. (2012) emphasized the need for considering them as part of the cultural heritage and legacy, worth of sustainable management and protection, especially to prevent possible ecological and economic losses, and increase the awareness of stakeholders through a deeper comprehension of the paleosols in the frame of the quaternary landscape evolution. adequate strategies of land planning should thus include information about paleosols and associated paleolandscapes, largely threatened by urbanization and other human activities, along with their cultural value rated through a set of intrinsic and extrinsic information. among these are their location and extension, geological setting and age, rarity of the diagnostic horizons, type of scientific interest and level of knowledge, state of preservation, type and intensity of risk, active and potential measures of protection, accessibility, exposure and visibility, tested through a large database of paleosols in italy (costantini et al., 2007a; costantini & l’abate, 2009; costantini, 2018). based on a study in the lombardy region, costantini et al. (2007a) proposed an enlargement of parks and natural protected areas as a suitable policy for the preservation of the paleosol heritage, especially those of outstanding cultural value. moreover, costantini (2018) stressed the need for compiling a red list of the european (and possibly worldwide) “pedosites” where paleosols pedodiversity (sensu ibanez & bockheim, 2013) have high risk of degradation and extinction. costantini & l’abate (2009) and bollati & zerboni (2021) remarked how paleopedological heritage and pedodiversity recorded by paleosols in natural and archaeological contexts (in places also including paleontological remnants) can contribute to the geodiversity and geomorphodiversity expressed by traditional “geosites”. they can thus add value to the geoheritage, not only from a scientific perspective related to a site-intrinsic geodiversity, but also from their potential for use. in this respect, paleosols are expressions of richness and diversity of the natural and human-related history of the local territory and valuable resources for the citizens living therein, in terms of cultural and educational values, along with functional, aesthetic, recreational and geotouristic potential, worth of being promoted and valorized, for instance planning ‘soil trails’ (masseroli et al., 2022) as geocultural itineraries. therefore, the pedodiversity of pleistocene paleosols needs to be protected from its vulnerability to natural and anthropogenic threats. also the cecita lake geosol mentioned above (section 2) warrants attention in respect of its use, fertility and protection. its complex genesis, partly linked to the mixed origin of its parent materials, highlights the beneficial effects of the late pleistocene and holocene volcanic ashes as natural fertilizers. the rapid weathering of volcanic glass and associated pedogenic processes led to the neogenesis of poorly crystalline clay minerals (scarciglia et al., 2008), which contribute, together with a dominant loamy texture, to the high water-holding capacity under well-drained conditions. these geopedological properties likely promote the good quality of the local potato, along with the large temperature ranges between day and night and the cold winter climatic conditions, controlled by the elevation above 1000 m a.s.l.. the thickest and high waterproof peel of the sila tuber than other potatoes cultivated in europe, acts as a very efficient protective barrier against large temperature shifts. these in turn minimize the parasitizing potential, making treatments with pesticides less intensive or unnecessary. indeed, this agrifood product of excellence, largely cultivated in the sila plateau, displays specific organoleptic properties (higher starch content than average values, with consequent greater nutritious value and taste), based on which it holds the protected geographical indication (pgi) trademark attributed by the european union (data from ifex italian food excellence group, 2014). nonetheless, the severe surface erosion that affects the sila upland (raab et al., 2018; scarciglia et al., 2020), represents a real threat not only for the geosol itself, but even for the potato as a typical agricultural resource and other crops (mainly cereals, such as wheat and oats). actually, these are among the main drivers of the local economy together with pasture and farming, which in turn benefit from a good quality of grassland growing in the natural soil, sourcing hay and plant fruits for cattle, sheep and pigs, and direct food derivatives (milk, cheese and sausages). 5.2. pedogenic processes and potential pollution of paleosols another key issue regarding soil quality refers to the source, amount and spatial distribution of the so called “heavy metals”, i.e. potentially toxic elements (ptes), the role of the soil system as an environmental filter and the evaluation of its potential pollution. the work of costantini et al. (2002) pointed out the relevance of natural, pedogenic processes in addressing element behavior in some soil profiles of the montagnola senese (tuscany), and especially an enrichment in paleosols and deep horizons, often neglected in favor of investigations involving topsoils only. among the main results are a control of metal amounts by neogenesis and illuviation of clays, with local element depletion and leaching within eluvial zones and under reducing conditions, along with an increase of some ptes (cr, pb, zn, mn) with soil age, thus showing higher amounts in early and middle pleistocene paleosols than in holocene soils. these results support the need of a detailed methodological approach combining field data with physical and geochemical laboratory analyses in order to evaluate the effective filter and sink capacity of soils and paleosols in respect to pollutants, and the need for an adequate regulation. similar findings and highlights were reported with more detailed, multi-analytical and multiscale methodologies in a series of linked papers, where for the 168 scarciglia f. et al. first time inductively coupled plasma mass spectrometry equipped with laser ablation (la-icp-ms) was applied on thin sections of soils and paleosols of sardinia in the muravera area (see section 4.1), and integrated with soil micromorphology and geochemistry (scarciglia et al., 2009, 2011; scarciglia & barca, 2017). these works successfully traced the behavior and fate of trace elements including rare earths and potential pollutants at the microsite level, allowing discriminating the contribution of ptes in relation to the intrinsic spatial variability of soil profiles and pedogenic features. in particular, trace metals were assessed in discrete soil subcomponents, such as skeletal rock fragments, clayenriched and humified pedogenic matrix, and specific pedofeatures of illuvial origin (unstained or iron-stained clay coatings) in a and bt horizons. the role of mineral weathering and soil formation processes was clearly demonstrated, tracing the release and fractionation of ptes and other trace metals from primary components of the parent rocks, their adsorption onto negatively charged surfaces of clay minerals, iron oxyhydroxides and/or organic matter through their cation exchange capacity, and their enrichment/migration through illuviation processes. this approach permitted to assess ptes even at very low contents, i.e. at early stages of concentration due to pedogenic processes, which could be an efficient tool for prevention of soil pollution and adequate risk mitigation strategies. scarciglia and coauthors revealed an anthropogenic contribution of heavy metal-bearing mineral grains sourced from abandoned mine plants, in addition to the natural host rocks, and a prominent interplay of soil-forming processes with geomorphic dynamics to explain the spatial distribution of trace elements. part of the geochemical behavior in different horizons of the paleosols can be considered as inherited from past, now inactive genetic processes, superimposed by younger and current processes. 5.3. geotechnical and seismic behavior of paleosols few papers showed that the specific properties of some italian paleosols can have a great relevance also in the light of geotechnical, engineering and construction purposes. it is the case of the hard, cemented caranto paleosol extensively found under sediments in the area of the venice lagoon (see section 2). donnici et al. (2011) found relatively high unconfined compressive and shear strengths in response to pedogenic processes and consolidation under aerial exposure conditions, compared to unweathered lagoonal deposits. these properties permitted its use as a valuable substrate for the foundations of only a few larger constructions directly extending into the caranto. conversely, it represented a more resistant layer, able to support the overlying plastic lagoon deposits, loaded by the foundations of most of the venetian buildings, and thus acting as their lowest constraint. this behavior increased structural stability, drove the location of human settlements since gothic times (12th-15th centuries a.d.), when venice widely experienced much of its urbanization, and allowed the preservation of buildings even after several historical earthquakes. another interesting case study is the recent work of tallini et al. (2020), who explored the potential link of paleosols with seismic site effects in the l’aquila downtown (abruzzo region, central italy). this urban area is characterized by a high seismic risk and was severely damaged by a high magnitude (mw 6.1) earthquake in 2009. the researchers hypothesized that the shaking effects of the earthquake could have been amplified by the local presence of a reddish colluviated alfisol developed during the late pleistocene, overlying a weathered epikarst zone on calcareous slope breccias of middle pleistocene age, in turn burying a masocenozoic bedrock. the varying spatial distribution of the red paleosol in terms of surface and depth extension, seems to be responsible for the medium microtremor frequency (3-13 hz) recorded site-by-site in the area, suggesting a seismic resonance, i.e. a seismic coupling of the shallow geopedological setting with the fundamental frequency of the buildings. the areal distribution of buildings that were affected by damages or collapsed during the 2009 and 1703 earthquakes of l’aquila strongly supported the hypothesis of a seismic paleosolbuilding coupling. this work highlighted the great potential of characterizing paleosols, as usually neglected, to assess seismic hazard and associated risk in areas with high current, historical and late quaternary seismicity, such as almost the entire italian territory and several other countries worldwide. in many cases paleosols could provide useful data in defining seismic site effects, thus helping in mitigating the seismic risk of urban areas, especially where historical constructions are more vulnerable to earthquake dynamic solicitations and have high cultural heritage value. 5.4. applications to geoarchaeology the contribution of paleopedology and related analytical methods (especially micropedology) to the archaeological research is well established (courty et al., 1989; macphail & goldberg, 2017) and relies on the general concept that the formation and preservation of archaeological sites and anthropogenic sequences is ruled out by the same processes that oversee the formation of soil: pedogenesis controls the transformation of each sediment at the earth’s surface including the anthropogenic ones and those entombing artefacts. several researchers have used archaeological findings (which are widespread and frequently detected in paleosols of italy because of a long-lasting flourishing of civilizations and pedosedimentary stratification of remains of different epochs) as valuable tools to fix some chronological constraints to paleosol development. to this purpose, both the vestigiae of settlements and human artifacts have revealed their great potential, often allowing a correlation of major paleopedogenic features (and associated processes) with other paleoclimatic/environmental proxies. the investigation of archaeological materials occasionally revealed the exploitation of georesources, including the use of clay-rich b horizons from pleistocene paleosols to make bricks or pottery, thus allowing to trace the provenance of raw materials. for instance, at the pulo di molfetta neolithic sites, people largely exploited the local clay-rich terra fusca-type paleosol (fig. 16a, b), corresponding to the pristine infilling of a sinkhole (muntoni & zerboni, 2017). in general, we must keep in mind that the stratification of archaeological layers and archaeological soils 169 pleistocene paleosols of italy: ... results from the interplay of two contrasting types of processes (cremaschi & rodolfi, 1991; cremaschi, 2000). on the one hand, human agency controlled all the processes, including the accumulation of sediments and its physical and chemical transformation. such processes prevailed during the phase of life of an archaeological site. on the other hand, after the abandonment of an archaeological site, the onset of natural processes of 170 fig. 16 microphotographs of: (a, b) reworked terra fusca-type soil material from the pulo di molfetta archaeological site; (c, d) strong redistribution of caco3 from a late pleistocene occupational layer in the uluzzo c rock shelter; granular aggregates and occasional bone fragments are visible; (e, f) aeolian quartz grains and red, rounded pedorelicts cemented by calcite from a late pleistocene layer of the uluzzo c rock shelter; a fragment of laminated speleothem crust (lithorelict) is visible. f shows at higher magnification the same features as in e. frames a, c, e are in plane polarized light and frames b, d, f are in crossed polarized light. scarciglia f. et al. pedogenesis modified anthropogenic sediments. in italy, paleopedology supported the geoarchaeological investigation on several archaeological sequences dating to the pleistocene, including open-air and sheltered sites. in the case of open-air contexts, archaeological layers interlayered to the pedostratigraphic sequences or archaeological soils containing evidence of human exploitation generally underwent deep pedogenesis affecting also archaeological materials. one of the most important italian archaeological sites dating to the lower paleolithic is the isernia la pineta butchering site, dated to the beginning of the early/middle pleistocene transition. therein, a complex sequence of fluvial lacustrine, spring, and volcanic sediments includes a layer of cross -bedded gravels, where a thick alfisols with a wellexpressed bt horizon developed (coltorti et al., 1982, 2005). middle palaeolithic occupation layers are preserved at many localities of the northern margin of the apennines at the interface between continental fluvial sediments and late pleistocene loess sediments. at those locations, mousterian hunters exploited the elevated surface of fluvial terraces to establish temporary campsites. this phase of human occupation was contemporary with the early period of loess sedimentation (cremaschi et al., 2015). at ghiardo site (emilia romagna), extensive archaeological excavations and paleopedological analyses highlighted the occurrence of deeply weathered loess deposits, including a sequence of bt horizons laying on top of a bc horizon marked by the formation of abundant mn/fe nodules and concretions (fig. 12b). holocene pedogenesis promoted a strong neoformation and illuviation of clay along the loessic soil, whereas in correspondence of the occupation layer water-logged conditions promoted hydromorphic features (fig. 13). a systematic investigation disclosed the existence of a buried undulated surface, interpreted as a gilgai microrelief and likely caused by long-lasting vertic process (cremaschi & christopher, 1984). at those sites, pedogenesis also affected lithic artifacts, whch displayed specific (yellowish-brown to reddish) patination depending on the specific setting of the soil horizons where they were entombed; in this case, soil science is helpful in explaining secondary displacement of archaeological materials. mousterian artifacts are commonly found along loess sequences at the margin of the po plain (baroni, 1986; cremaschi, 1987, 1990; zerboni et al., 2018) and are useful chronological indicators for the age of pedostratigraphic sequences dating to mis 3. a further example of open-air site is at monte netto and displays a multiple human occupation of the top of the hill during the middle and the late pleistocene (baroni et al., 1986; zerboni et al., 2015; delpiano et al., 2019); therein, the uppermost archaeological soil preserves a mousterian temporary camp site, whereas the deepest reddish soil contains ephemeral evidence of human occupation in the middle pleistocene. those examples suggest that paleosols have a great potential for the interpretation of the environmental conditions at the time of pleistocene occupation of the italian peninsula during both glacial (and stadial) and interglacial (and interstadial) phases. the application of paleopedology to cave/rock shelter contexts sometimes is a challenging task, because natural and anthropogenic sediments are juxtaposed and the influence of pedogenesis on the evolution of sediments is hampered by the geomorphological settings. in fact, cave/rock shelter sites are naturally protected from external forcing. if this limits the influence of post-depositional soil-forming processes, on the other hand increases the possibility to preserve archaeological sediments. as acknowledged by laville et al (1980), the atrial part of caves and rock shelters is a preferential trap for sediments. the same authors reported that each type of sediments found in such contexts at middle latitudes of europe thus including italy were formed by specific processes triggered by glacial/interglacial climatic conditions. evidence of the so-called laville cycle has been identified at several cave-sites in northern italy (cremaschi, 2000), where the paleopedological and micromorphological approach supported a precise interpretation of the stratigraphy and the identification of climate-triggered processes. the most iconic investigation was carried out at fumane cave (lessini mts., veneto), where pioneering geoarchaeological investigations followed each step of the archaeological excavation since the discovery of the archaeological site. therein, the paleopedological approach helped in disclosing the meaning of the stratigraphy, identifying at the micro-scale evidence of different processes, likely occurred since the last interglacial up to the apogee of the last glacial maximum (peresani et al., 2008). the earliest processes recorded in thin sections at fumane cave were the weathering of the limestone bedrock of the rock shelter and the formation of a colluvial layer of reddish soil material during warm conditions. a subsequent transition towards cold and arid climate were recorded by loess accumulation interlayered to breccias and anthropogenic layers, alng with frost-related pedofeatures (ferraro, 2002; cremaschi et al., 2005). in other cases, paleopedology supported archaeological investigations in reconstructing the processes and rates of cave infilling, as in the lateglacial grotta continenza site in central italy (boschian et al., 2017). therein, thin section micromorphology contributed to interpret the interplay between dust input and colluvial processes in the formation of the stratigraphy. a further example of the investigation on cave-sites concerns caves and rock shelters located along shorelines. along the italian peninsula, many caves and rock shelters have been exploited in the middle and late pleistocene and methods borrowed from soil science revealed the complexity of processes in charge of the formation of archaeological sediments and supported the reconstruction of climatic changes. the balzi rossi archaeological area has been investigated since the beginning of the last century, but only few investigations included the study of sediments. for instance, cremaschi (1993) reported on the ex-birreria archaeological sequence, which includes at its base a red, clay-rich soil, likely developed at the end of the last interglacial and then buried by colluvia at the onset of the last glacial period; more recently, zambaldi (2020) came to the same conclusions. in the same area, geoarchaeology supported the identification of a subsequent climatic event at the riparo mochi site (douka et la., 2012), whereas micromorphology in thin sections helped in the identification of bioturbation affecting late pleistocene 171 pleistocene paleosols of italy: ... archaeological sediments, including cryptotephras at the riparo bombrini site (hirniak et al., 2020). at grotta guattari (central italy), cremaschi et al. (2022) applied several methods to understand the peculiar pedogenic processes affecting the archaeological stratigraphy and influencing the preservation of biogenic phosphates and heavy minerals. the authors concluded that bones did not survive in some layers and the occurrence of phosphates was related to the formation of ca-al and cafe phosphates derived from the weathering of bat guano. the same conditions affected the heavy mineral assemblage, leading to the disappearance of the most labile ones. geoarchaeological and paleopedological investigations at several key sites of apulia (southern italy) disclosed the interplay between relative sea-level changes, continental surface processes, and human peopling since the middle pleistocene. at grotta paglicci (gargano promontory) thin section micromorphology and the study of heavy minerals highlighted a first phase of sedimentation controlled by the wind input of weathered volcanic material, followed by cryotic conditions and loess deposition (cremaschi & ferraro, 2007). similar conditions were observed at the uluzzo c rock shelter (spinapolice et al., 2022), where micropedology helped in the reconstruction of the formation processes, which include strong bioturbation and, in the mousterian layers, a huge redistribution of calcite forming an almost continuous breccia (fig. 16c-f). at the same site, the identification of former terra rossa‐type soil fragments (rolled pedorelicts) and speleothem clasts (fig. 16e, f) suggested an occasional reactivation of the hydrology of the local karst system under more humid conditions and the erosion of surface soils and older karst infillings. at grotta romanelli the application of geoarchaeology and paleopedology helped in the reassessment of the stratigraphic sequence, shedding new light on the formation processes of each stratigraphic unit and the interplay between the deposition and the weathering of sediments (pieruccini et al., 2022; russo ermolli et al., 2022). 7. some problems, open questions, conclusive remarks and perspectives the nature of paleosols is intrinsically diachronic (time-transgressive) and they are often spatially discontinuous. nonetheless, the abundant and variegated literature on italian case studies demonstrates that they can be successfully used as complementary proxies to others that are usually more continuous in time and space or simply intrinsically quantitative. in many cases (pleistocene) paleosols can be traced with large lateral continuity and allow synchronizing further geological/ biological archives interlayered in-between. at regional and extra-regional scales, they may allow a comparison of different local responses to more global paleoclimatic/ environmental changes, providing a deeper understanding of the spatio-temporal climate variability during quaternary times. a relevant issue worth mentioning regards several surface soils widespread from the alpine chain to the mountainous relieves and coastal areas of southern italy. they are often poorly differentiated into pedogenic horizons and overall weakly developed, although the ages of their local substrates can be much older (d’amico et al., 2016; scarciglia et al., 2015, 2016, 2020; raab et al., 2018). according to site-specific geoenvironmental characteristics, the authors interpreted this behavior as a response to paleoand/or historical to modern environmental changes that took place over time. among the possible explanations are extensive pleistocene glaciations, intrinsic or weathering-induced properties of parent materials, topographic features (namely high local relief and steep slopes) controlled by tectonic uplift or river dissection, climate shifts and/or land-use changes, which made the soil mantles highly susceptible to erosion and efficiently eroded over time. nonetheless, on some relict planation surfaces characterized by a relative geomorphic stability, and/or buried by younger sediments and associated soils (e.g., in the outermost reaches of the alps and on the sila upland plateau), some better developed and mature paleosols are at least partly preserved, often in small patches (d’amico et al., 2016; scarciglia et al., 2007, 2008). they display some features that are not consistent with holocene soil formation processes, but record paleoenvironmental/climatic conditions that can still be adequately reconstructed. however, this task cannot always be achieved, for instance in case of diagnostic features of seasonal freezing and thawing, which form in the active layer, or albic (eluvial) horizons in podzols. as these processes involve only the topsoil and shallow (subsurface) horizons, their evidence is very frequently lost because of soil profile truncation by erosion. in our opinion, this could be a reason why past periglacial conditions cannot be extensively assessed and might be underestimated in the italian paleopedological archives. worth to remark is also the difficult distinction between traces of seasonal freezing and permafrost conditions in paleosols from zones that are nowadays not glaciated or very far from glaciers, even in coastal area, although other paleoclimatic archives, geomorphological, stratigraphic and isotopic signatures may help solving this dilemma. similarly, several rubified and clay-illuviated paleosols lack of the corresponding surface a horizons and/or clay-depleted e horizons, and in places of part of the bt horizons themselves. this prevents an estimation of the original soil profile depth and of the extent of clay translocation, and possibly of other diagnostic features. nonetheless, the occurrence of paleosols with welldeveloped bt horizons often at the ground surface (fig. 5a) appears a clear evidence of severe erosion (robustelli et al., 2009; scarciglia et al., 2015). we cannot exclude that a decrease of soil porosity due to stacking of translocated clay particles onto pore surfaces could have hampered water infiltration, enhancing water runoff and erosion. in this respect, an interesting point to investigate would be the possible role of illuvial clay enrichment downprofile as a predisposing factor of shallow landslides affecting paleosols, where the consequently diminished drainage conditions in the subsoil could trigger the detachment and failure of upper horizons. the truncation and exposure of paleosols at the topographic surface, the complementary colluviation downslope triggered by wateror gravity-driven reworking processes and their burial by younger soils are a 172 scarciglia f. et al. common cause of a polygenetic imprint of pedogenic processes, some of which may record past environmental/climatic conditions and some others recent or modern ones. a clear discrimination between these different stages of soil formation cannot be always assessed, at least in the field. such geomorphic dynamics may also cause soil ageing or rejuvenation, e.g., on exposed terraced surfaces of soil chronosequences (cf. section 3), but soil micromorphology and geochemistry revealed to be of great help to provide reliable interpretations. the interpretation of the genesis of buried paleosol can be complicated because of potential modification of their properties after burial, in addition to the above discussed truncation, which is often synchronic with the sedimentation event leading to burial. in case of younger pedogenesis affecting the overlying sediments, further soil formation processes often occurred with two potentially different evolutionary trends. on the one hand, pedogenesis might have kept the same direction under similar climatic/environmental conditions, simply leading to superimposition of different generations of similar features (polycyclic). on the other hand, it might have evolved towards a different direction under varied conditions, with new pedogenic features overprinted on past, relic ones (polygenetic). major changes might have involved: (i) leaching/eluviation and accumulation/ illuviation of soluble substances or suspended particles sourced from the overlying (sometimes allochthonous and genetically different) parent material(s); (ii) compaction and changes in pedogenic structure, soil porosity and permeability, drainage and redox conditions. therefore, it is sometimes very difficult to interpret the resulting soil properties as occurred prior to or after the burial. this is a hard task to achieve especially when the paleosol is buried by very shallow sediments (and soils), which do not seal the buried paleosol from more recent pedogenesis, possibly masking lithological or erosive discontinuities, or when the overlying deposits, even despite very thick, may be highly porous and permeable and exert a poor sealing effect. this could be still more complicated when the paleosols were buried under submerged (e.g., marine) conditions (fig. 8) (scarciglia et al., 2003a, b) and/or were affected by waterlogging (cremaschi et al., 2015). the consequences of erosion and pollution (discussed above) and of other natural or human threats, nowadays often enhanced by ongoing climatic changes and increasing anthropogenic pressure on the environment, poses our attention on the potential resilience of pleistocene paleosols. their time ranges of development are in the order of 104 to 106 years, possibly under varying climatic/environmental conditions, as potentially subjected to one or more alternations of stadial/interstadial and interglacial/glacial cycles as far as the time spans increased. in such long intervals, the paleosols reached their specific properties, but their possible loss or degradation often took (or might take) place even in much shorter times. this implies their poor or null resilience and recovery at human scale, not only because of this time issue, but also in terms of nonreproducible paleoenvironmental conditions and corresponding pedogenic features. current and future pedogenesis would have different pathways from the past, and even additional peculiarity if we consider paleosols derived from volcanic products of pleistocene eruptions, which will not likely occur as in the past. one additional lesson that the pleistocene paleosols of italy teach us is the potential ability to discriminate between natural and anthropogenic drivers of landscape dynamics, based on the identification and interpretation of key features of past pedogenesis and corresponding environmental responses. this is a key tool for prediction of the potential responses of the earth system to forthcoming scenarios and provision of best-suited strategies for adaptation. in addition, pleistocene paleosols of different ages can be useful proxies for the assessment of geological/ geomorphological hazards and associated risks, based on long-term records of periods characterized by relative geomorphic stability prone to pedogenesis alternated to overall unstable and hazardous environments marked by floods, landslides, soil erosion and volcanic eruptions. acknowledgements we are grateful to vito bracone, mauro cremaschi, ivano rellini and veronica zumpano for providing some photos. we thank an anonymous reviewer and the editor in chief ilaria mazzini for their constructive comments. references aghib f., muttoni g., norini g., mariani g.s., zerboni a., de franco r., di capua a., tira, m.a., brusamolino a., menici s., caielli g., groppelli g., piccin a. (in press) the pleistocene tectono-stratigraphic evolution of the northern po plain (italy) around the castenedolo and ciliverghe hillocks. quat. res. ajmone marsan f., barberis e., arduino e. (1988) a soil chronosequence in northwestern italy: morphological, physical and chemical characteristics. geoderma, 42, 51-64. doi: 10.1016/0016-7061(88)90022-5 ajmone marsan f., torrent j. (1989) fragipan bonding by silica and iron oxides in a soil from northwestern italy. soil science society of america journal, 53, 1140-1145. doi: 10.2136/sssaj1989.03615995005300040025x ajmone marsan f., pagliai m., pini r. (1994) identification and properties of fragipan soils in the piemonte region of italy. soil science society of america journal, 58, 891-900. doi: 10.2136/sssaj1994.03615995005800030037x amato a., dimase a.c. (1997) paleoenvironmental features and geomorphologie evolution of the middle agri valley plateaux (basilicata) caratteristiche paleoambientali ed evoluzione geomorfologica dei plateau dell a media valle del fiume agri (basilicata). alpine and mediterranean quaternary, 10(2), 213-230. amorosi a., antonioli f., bertini a., marabini s., mastronuzzi g., montagna p., negri a., rossi v., scarponi d., taviani m., angeletti l., piva a., vai g.b. (2014a) the middle-upper pleistocene fronte section (taranto, italy): an exceptionally 173 pleistocene paleosols of italy: ... preserved marine record of the last interglacial. global planet. change, 119, 23-38. doi: 10.1016/j.gloplacha.2014.04.007 amorosi a., bruno l., rossi v., severi p., hajdas i. (2014b) paleosol architecture of a late quaternary basin margin sequence and its implications for high-resolution, non-marine sequence stratigraphy. global planet. change, 112, 12-25. doi: 10.1016/j.gloplacha.2013.10.007 amorosi a., bruno l., campo b., morelli a. (2015) the value of pocket penetration tests for the highresolution palaeosol stratigraphy of late quaternary deposits. geol. j., 50, 670-682. doi: 10.1002/gj.2585 amorosi a., bruno l., campo b., di martino a., sammartino i. (2021) patterns of geochemical variability across weakly developed paleosol profiles and their role as regional stratigraphic markers (upper pleistocene, po plain). palaeogeography, palaeoclimatology, palaeoecology, 574, 110413. doi: 10.1016/j.palaeo.2021.110413 andreucci s., clemmensen l.b., murray a.s., pascucci v. (2010) middle to late pleistocene coastal deposits of alghero, northwest sardinia (italy): chronology and evolution. quat. int., 222(1-2), 3-16. doi: 10.1016/j.quaint.2009.07.025 andreucci s., bateman m.d., zucca c., kapur s., akşit i̇., dunajko a., pascucci v. (2012) evidence of saharan dust in upper pleistocene reworked palaeosols of north-west sardinia, italy: palaeoenvironmental implications. sedimentology, 59(3), 917 -938. doi: 10.1111/j.1365-3091.2011.01285.x arduino e., barberis e., carraro f., forno m.g. (1984) estimating relative ages from iron-oxide/total-iron ratios of soils in the western po valley, italy. geoderma, 33, 39-52. doi: 10.1016/0016-7061(84)90088-0 arduino e., barberis e., ajmone marsan f., zanini e., franchini m. (1986) iron oxides and clay minerals within profiles as indicators of soil age in northern italy. geoderma, 37, 45-55. doi: 10.1016/0016-7061(86)90042-x assallay a.m., jefferson, i.f., rogers, c.d.f., smalley, i.j. (1998) fragipan formation in loess soils: development of the bryant hydroconsolidation hypothesis. geoderma 83, 1-16. doi: 10.1016/s0016-7061(97)00135-3 aucelli p., amato v., cesarano m., pappone g., rosskopf c.m., russo ermolli e., scarciglia f. (2011) new morphostratigraphic and chronological constraints for the quaternary paleosurfaces of the molise apennine (southern italy). geologica carpathica, 62(1), 17-26. doi: 10.2478/v10096-011-0002-2 badía-villas d., poch r.m., longares l.a., yuste a., bauluz b. (2022) genesis and stability of textural pedofeatures along a soil transect in the siliceous iberian chain (ne spain). catena, 211, 105965, 113. doi: 10.1016/j.catena.2021.105965 badino f., pini r., ravazzi c., margaritora d., arrighi s., bortolini e., figus c., giaccio b., lugli f., marciani g., monegato g., moroni a., negrino f., oxilia g., peresani m., romandini m., ronchitelli a., spinapolice e.e., zerboni a., benazzi s. (2020) an overview of alpine and mediterranean palaeogeography, terrestrial ecosystems and climate history during mis 3 with focus on the middle to upper palaeolithic transition. quat. int. 551, 7-28. doi: 10.1016/j.quaint.2019.09.024 ballantyne c.k. (2010) a general model of autochthonous blockfield evolution. permafr. periglac. process., 21, 289-300. doi: 10.1002/ppp.700 baroni c. (1986). rinvenimento di manufatti litici sulla collina di castenedolo (brescia). natura bresciana, 23, 385-386. baroni c., cremaschi m., peretto c. (1986) recenti ritrovamenti paleolitici in lombardia. atti ii convegno archeologico regionale, 13-15 aprile 1984, como villa olmo. new press, como, 363-378. bertini a. (2010) pliocene to pleistocene palynoflora and vegetation in italy: state of the art. quat. int., 225, 5-24. doi: 10.1016/j.quaint.2010.04.025 bertini a., toti f., marino m., ciaranfi n. (2015) vegetation and climate across the early-middle pleistocene transition at montalbano jonico, southern italy. quat. int., 383, 74-88. doi: 10.1016/j.quaint.2015.01.003 billard a., orombelli g. (1986) quaternary glaciations in the french and italian piedmonts of the alps. quat. sci. rev., 5, 407-411. doi: 10.1016/0277-3791(86)90205-2 boenzi f., palmentola g. (1974) prima segnalazione di tracce glaciali würmiane nei dintorni di monte botte donato (sila). bollettino della società geologica italiana, 93, 309-315. boenzi f., palmentola g. (1975) osservazioni sulle tracce glaciali della calabria. bollettino della società geologica italiana, 94, 961-977. bollati i.m., zerboni, a. (2021) the po plain loess basin (northern italy): scientific values, threats, and promotion opportunities. geoheritage, 13(3), 74. doi: 10.1007/s12371-021-00596-2 boretto g., zanchetta g., ciulli l., bini m., fallick a.e., lezzerini m., colonese a.c., zembo i., trombino l., regattieri e., sarti g. (2017) the loess deposits of buca dei corvi section (central italy): revisited. catena, 151, 225-237. doi: 10.1016/j.catena.2017.01.001 boschian g., serradimigni m., colombo m., ghislandi s., grifoni cremonesi r. (2017) change fast or change slow? late glacial and early holocene cultures in a changing environment at grotta continenza, central italy. quat. int., 450, 186-208. doi: 10.1016/j.quaint.2016.12.027 bracone v., amorosi a., aucelli p.p.c., rosskopf c.m., scarciglia f., di donato v., esposito p. (2012) the pleistocene tectono-sedimentary evolution of the apenninic foreland basin between trigno and fortore rivers (southern italy) through a sequencestratigraphic perspective. basin research, 24(2), 174 scarciglia f. et al. 213-233. doi: 10.1111/j.1365-2117.2011.00523.x brewer r. (1976) fabric and mineral analysis of soils. robert e. krieger publishing company, huntington, new york, pp. 482. bronger a. (1969/70) zur mikromorphogenese und zum tonmineralbestand quartärer lössböden in südbaden. geoderma, 3, 281-320. doi: 10.1016/0016-7061(70)90011-x bronger a., sedov s. (2003) vetusols and paleosols: natural versus man-induced environmental change in the atlantic coastal region of morocco. quat. int., 106-107, 33-60. doi: 10.1016/s1040-6182(02)00160-x bruno l., amorosi a., severi p., costagli b. (2017) late quaternary aggradation rates and stratigraphic architecture of the southern po plain, italy. basin research, 29(2), 234-248. doi: 10.1111/bre.12174 bruno l., marchi m., bertolini i., gottardi g., amorosi a. (2020) climate control on stacked paleosols in the pleistocene of the po basin (northern italy). journal of quaternary science, 35(4), 559-571. doi: 10.1002/jqs.3199 busacca a., cremaschi m. (1998) the role of time versus climate in the formation of deep soils of the apennine fringe of the po valley, italy. quat. int., 51-52, 95-108. doi: 10.1016/s1040-6182(97)00036-0 campo b., amorosi a., vaiani s.c. (2017) -sequence stratigraphy and late quaternary paleoenvironmental evolution of the northern adriatic coastal plain (italy). palaeogeography, palaeoclimatology, palaeoecology, 466, 265-278. doi: 10.1016/j.palaeo.2016.11.016 capezzuoli e., priori s., costantini e.a.c., sandrelli f. (2009) stratigraphic and paleopedological aspects from the middle pleistocene continental deposits of the southern valdelsa basin. bollettino della società geologica italiana italian journal of geosciences, 128(2), 395-402. doi: 10.3301/ijg.2009.128.2.395 capraro l., asioli a., backman j., bertoldi r., channell j.e.t., massari f., rio d. (2005) climatic patterns revealed by pollen and oxygen isotope records across brunhes-matuyama boundary in the central mediterranean (southern italy). in: head m.j., gibbard p.l. (eds.), early-middle pleistocene transitions: the land-ocean evidence. geological society of london, special publication 247,159 -182. doi: 10.1144/gsl.sp.2005.247.01.09 carboni s., palomba m., vacca a., carboni g. (2006) paleosols provide sedimentation, relative age, and climatic information about the alluvial fan of the river tirso (central-western sardinia, italy). quat. int., 156/157, 79-96. doi: 10.1016/j.quaint.2006.05.005 carnicelli s., ferrari g.a., magaldi d. (1989) les accumulations carbonates de type “calcrete” dans les sols et formations superficielles d’italie méridionale. méditerranée, 68, 51-59. carnicelli s., benvenuti m., andreucci s., ciampalini r. (2015) late pleistocene relic ultisols and alfisols in an alluvial fan complex in coastal tuscany. quat. int., 376, 163-172. doi: 10.1016/j.quaint.2014.10.009 catt j.a. (1998) report from working group on definitions used in paleopedology. quat. int., 51/52, 84. doi: 10.1016/s1040-6182(98)90232-4 cerrone c., ascione a., robustelli g., tuccimei p., soligo m., balassone g., mormone a. (2021) late quaternary uplift and sea level fluctuations along the tyrrhenian margin of basilicata northern calabria (southern italy): new constraints from raised paleoshorelines. geomorphology, 395, 107978, 1-19. doi: 10.1016/j.geomorph.2021.107978 certini g., ugolini f.c., taina i., bolla g., corti g., tescari f. (2007) clues of the genesis of a discontinuously distributed fragipan in the northern apennines, italy. catena, 69, 161-169. doi: 10.1016/j.catena.2006.05.005 chelli a., d’aquila p., firpo m., ginesu s., guglielmin m., pappalardo m., pecci m., piacentini t., queirolo c., robustelli g., scarciglia f., sias s., tellini c. (eds.) (2006) testimoni di una montagna scomparsa. contributo alle metodologie d’indagine delle forme periglaciali relitte. problematiche e applicazioni in differenti ambienti morfodinamici. imont (istituto nazionale della montagna) aigeo (associazione italiana di geografia fisica e geomorfologia). quaderni della montagna, 8, bononia university press, bologna, italy, pp. 136. colombo c., sellitto m.v., palumbo g., terribile f., stoops g. (2007) characteristics and genesis of volcanic soils from south central italy: mt. gauro (phlegraean fields, campania) and vico lake (latium). in: in: arnalds ó., óskarsson h., bartoli f., buurman p., stoops g., garcía-rodeja e. (eds.), soils of volcanic regions in europe. springer, berlin, heidelberg, 197-229. doi: 10.1007/978-3-540-48711-1_18 colombo c., palumbo g., di iorio e., russo f., terribile f., jiang z., liu q. (2016) soil development in a quaternary fluvio-lacustrine paleosol sequence in southern italy. quat. int., 418, 195-207. doi: 10.1016/j.quaint.2015.11.004 coltorti m., dramis f. (1988) the significance of stratified slope-waste deposits in the quaternary of umbria-marche apennines, central italy. zeitschrift für geomorphologie, supplementband 71, 59-70. coltorti m., pieruccini p. (2006) the last interglacial pedocomplexes in the lithoand morphostratigraphical framework of the central-northern apennines (central italy). quat. int., 156/157, 118132. doi: 10.1016/j.quaint.2006.05.025 coltorti m., cremaschi m., delitala m.c., esu d., fornaseri m., mcpherron a., nicoletti m., van otterloo r., peretto c., sala b., schmidt v., sevink j. (1982) reversed magnetic polarity at an early lower palaeolithic site in central italy. nature, 300, 173-179. doi: 10.1038/300173a0 coltorti m., feraud g., marzoli a., peretto c., ton-that 175 pleistocene paleosols of italy: ... t., voinchet p., bahain j.-j., minelli a., thun hohenstein u. (2005) new 40ar/39ar, stratigraphic and palaeoclimatic data on the isernia la pineta lower palaeolithic site, molise, italy. quat. int., 131(1), 11-22. doi: 10.1016/j.quaint.2004.07.004 coltorti m., melis e., patta d. (2010) geomorphology, stratigraphy and facies analysis of some late pleistocene and holocene key deposits along the coast of sardinia (italy). quat. int., 222, 19-35. doi: 10.1016/j.quaint.2009.10.006 costantini e.a.c. (2018) paleosols and pedostratigraphy. applied soil ecology, 123, 597-600. doi: 10.1016/j.apsoil.2017.09.021 costantini e.a.c., napoli r. (1996) properties and geographic relevance of fragipan and other closepacked horizons in a non-glaciated mediterranean region. geogr. fis. dinam. quat., 19(1), 29-45. costantini e.a.c., damiani d. (2004) clay minerals and the development of quaternary soils in central italy. rev. mex. cienc. geol., 21(1), 144-159. costantini e.a.c., priori s. (2007) pedogenesis of plinthite during early pliocene in the mediterranean environment. case study of a buried paleosol at podere renieri, central italy. catena 71, 425443. doi: 10.1016/j.catena.2007.03.015 costantini e.a.c., l’abate g. (2009) the soil cultural heritage of italy: geodatabase maps, and pedodiversity evaluation. quat. int., 209, 142-153. doi: 10.1016/j.quaint.2009.02.028 costantini e.a.c., angelone m., napoli r. (2002) soil geochemistry and pedological processes. the case study of the quaternary soils of the montagnola senese (central italy). alpine and mediterranean quaternary, 15(1), 111-120. costantini e.a.c., lessovaia s., vodyanitskii y. (2006) using the analysis of iron and iron oxides in paleosols (tem, geochemistry and iron forms) for the assessment of present and past pedogenesis. quat. int., 156/157, 200-211. doi: 10.1016/j.quaint.2006.05.008 costantini e.a.c., malucelli f., brenna s., rocca a. (2007a) using existing soil databases to consider paleosols in land planning. the case study of the lombardy region (northern italy). quat. int., 162163, 166-171. doi: 10.1016/j.quaint.2006.10.040 costantini e.a.c., napoli r., d’egidio g. (2007b) adding information about soils and paleosols to geological maps, through the application of the “pedostratigraphic level” concept. quat. int., 175, 125-139. doi: 10.1016/j.quaint.2007.05.006 costantini e.a.c., makeev a., sauer d. (2009) recent developments and new frontiers in paleopedology. quat. int., 209(1-2), 1-5. doi: 10.1016/j.quaint.2009.08.005 costantini e.a.c., bucelli p., priori s. (2012) quaternary landscape history determines the soil functional characters of terroir. quat. int., 265, 63-73. doi: 10.1016/j.quaint.2011.08.021 cottignoli a., boschian g., di maggio c., masini f., petruso d. (2002) pedostratigraphic notes on the middle-late pleistocene of capo san vito peninsula (nw sicily). alpine and mediterranean quaternary, 15(1), 121-130. cremaschi m. (1978) unità litostratigrafiche e pedostratigrafiche dei terreni quaternari pedeappenninici; loess e paleosuoli tra il fiume taro e il torrente sillaro. geogr. fis. dinam. quat., 1, 4-22. cremaschi m. (1987) paleosols and vetusols in the central po plain (northern italy): a study in quaternary geology and soil development. studi e ricerche sul territorio, 28, unicopli, milano, italy, pp. 306. cremaschi m. (2004) late pleistocene loess. in: antonioli f., vai g.b. (eds.), lithopalaeoenvironmental maps of italy during the last two climatic extremes. climex maps italy. museo geologico giovanni cappellini, bologna, italy. cremaschi m., christopher c. (1984) palaeolithic settlement and environment in the middle pleistocene of northern italy: the ghiardo site. the third conference of italian archaeology, vol. i, the environment. b.a.r., london, 87-104. cremaschi m., van vliet-lanoë b. (1990) traces of frost activity and ice segregation in pleistocene loess deposits of northern italy. deep seasonal freezing or permafrost? quat. int., 5, 39-48. doi: 10.1016/1040-6182(90)90023-w cremaschi m., trombino l. (1998a) eolianites, sea level changes and paleowinds in the elba island (central italy) during late pleistocene. in: busacca a.j. (ed.), dust aerosols, loess soils and global change, washington state university college of agriculture and home economics, pullman, wa, 131-134. cremaschi m., trombino l. (1998b) the palaeoclimatic significance of paleosols in southern fezzan (libyan sahara): morphological and micromorphological aspects. catena, 34, 131-156. doi: 10.1016/s0341-8162(98)00086-1 cremaschi m., rodolfi g. (1991) il suolo. pedologia nelle scienze della terra e nella valutazione del territorio. carocci editore, roma. cremaschi m., ferraro f. (2007) the upper pleistocene in the paglicci cave (gargano, southern italy): loess and tephra in the anthropogenic sequence. atti della società toscana di scienze naturali memorie serie a, 153-163. cremaschi m., orombelli g., salloway j.c. (1984) quaternary stratigraphy and soil development at the southern border of the central alps (italy): the bagaggera sequence. rivista italiana di paleontologia e stratigrafia, 90(4), 565-603. cremaschi m., fedoroff n., guerreschi a., huxtable j., colombi n., castelletti l., maspero a. (1990) sedimentary and pedological processes in the upper pleistocene loess of northern italy. the bagaggera sequence. quat. int., 5, 23-38. doi: 10.1016/1040-6182(90)90022-v cremaschi m., del lucchese a., negrino f., ottomano c., wilkens b. (1991) ventimiglia (imperia). località balzi rossi. nuovi dati sulla successione stratigrafica del ciclo interglaciale-glaciale-postglaciale. 176 scarciglia f. et al. scavi 1990. bollettino di archeologia, 8, 47-50. cremaschi m., ferraro f., peresani m., tagliacozzo a., (2005) il sito: nuovi contributi sulla stratigrafia, la cronologia, le faune a macromammiferi e le industrie del paleolitico antico. in: broglio a., dalmeri g. (eds.), pitture paleolitiche nelle prealpi venete: grotta di fumane e riparo dalmeri, memorie museo civico di storia naturale di verona, 2a serie, sezione scienze dell'uomo, 9, 12-22. cremaschi m., zerboni a., nicosia c., negrino f., rodnight h., spötl c. (2015) age, soil-forming processes, and archaeology of the loess deposits at the apennine margin of the po plain (northern italy). new insights from the ghiardo area. quat. int., 376, 173-188. doi: 10.1016/j.quaint.2014.07.044 cremaschi m., nicosia c., favero m. (2022) extreme diagenesis in the late pleistocene stratigraphic sequence of grotta guattari (central italy) and its impact on the archaeological record. quat. sci. rev., 298, 107732. doi: 10.1016/j.quascirev.2022.107732 d’amico m.e., freppaz m., filippa g., zanini e. (2014) vegetation influence on soil formation rate in a proglacial chronosequence (lys glacier, nw italian alps). catena, 113, 122-137. doi: 10.1016/j.catena.2013.10.001 d’amico m.e., catoni m., terribile f., zanini e., bonifacio e. (2016) contrasting environmental memories in relict soils on different parent rocks in the south-western italian alps. quat. int., 418, 6174. doi: 10.1016/j.quaint.2015.10.061 d’amico m.e., pintaldi e., catoni m., freppaz m., bonifacio e. (2019) pleistocene periglacial imprinting on polygenetic soils and paleosols in the sw italian alps. catena, 174, 269-284. doi: 10.1016/j.catena.2018.11.019 d’amico m.e., casati e., andreucci s., martini m., panzeri l., sechi d., el khair d.a., previtali f. (2021) new dates of a northern italian loess deposit (monte orfano, southern pre-alps, brescia). journal of soils and sediments, 21(2), 832841. doi: 10.1007/s11368-020-02860-4 degeai j.-p., villa v., chaussé c., pereira a., nomade s., aureli d., pagli m., nicoud e. (2018) chemical weathering of palaeosols from the lower palaeolithic site of valle giumentina, central italy. quat. sci. rev., 183, 88-109. doi: 10.1016/j.quascirev.2018.01.014 delpiano d., peresani m., bertola s., cremaschi m., zerboni a. (2019) lashed by the wind: short-term middle palaeolithic occupations within the loesspalaeosoil sequence at monte netto (northern italy). quat. int., 502, 137-147. doi: 10.1016/j.quaint.2019.01.026 de rosa, donato p., scarciglia f. (2016) on the origin and post-depositional history of widespread massive ash deposits: the case of intermediate brown tuffs (ibt) of lipari (aeolian islands, italy). journal of volcanology and geothermal research, 327, 135-151. doi: 10.1016/j.jvolgeores.2016.07.007 desio a. (1965) i rilievi isolati della pianura lombarda ed i movimenti tettonici del quaternario. rend. ist. lomb. acc. sci. lett., sez. a 99, 881-894. di celma c., pieruccini p., farabollini p. (2015) major controls on architecture, sequence stratigraphy and paleosols of middle pleistocene continental sediments (“qc unit”), eastern central italy. quaternary research, 83, 565-581. doi: 10.1016/j.yqres.2015.01.006 di celma c., ragaini l., caffau m. (2016) marine and nonmarine deposition in a long-term lowaccommodation setting: an example from the middle pleistocene qm2 unit, eastern central italy. marine and petroleum geology, 72, 234-253. doi: 10.1016/j.marpetgeo.2016.02.010 dimase a.c. (2006) fossil cryogenic features in paleosols of southern italy: characteristics and paleoclimatic significance. quat. int., 156/157, 32-48. doi: 10.1016/j.quaint.2006.05.032 donnici s., serandrei-barbero r., bini c., bonardi m., lezziero a. (2011) the caranto paleosol and its role in the early urbanization of venice. geoarchaeology, 26(4), 514-543. doi: 10.1002/gea.20361 d’orefice m., graciotti r., capitanio f. (2007) le eolianiti dell’isola d’elba: i depositi del promontorio del m. calamita e del golfo di viticcio. alpine and mediterranean quaternary, 20, 21-44. douka k., grimaldi s., boschian g., del lucchese a., higham t.f.g. (20129) a new chronostratigraphic framework for the upper palaeolithic of riparo mochi (italy). journal of human evolution 62, 286299. doi: 10.1016/j.jhevol.2011.11.009 egli m., nater m., mirabella a., raimondi s., plötze m., alioth l. (2008) clay minerals, oxyhydroxide formation, element leaching and humus development in volcanic soils. geoderma, 143, 101-114. doi: 10.1016/j.geoderma.2007.10.020 eppes m.c., bierma r., vinson d., pazzaglia f. (2008) a soil chronosequence study of the reno valley, italy: insights into the relative role of climate versus anthropogenic forcing on hillslope processes during the mid-holocene. geoderma, 147, 97-107. doi: 10.1016/j.geoderma.2008.07.011 falsone g., bonifacio e. (2009) pore-size distribution and particle arrangement in fragipan and nonfragipan horizons. journal of plant nutrition and soil science, 172, 696-703. doi: 10.1002/jpln.200800066 fedoroff n. (1997) clay illuviation in red mediterranean soils. catena, 28, 171-189. doi: 10.1016/s0341-8162(96)00036-7 ferranti l., antonioli f., mauz b., amorosi a., dai pra g., mastronuzzi g., monaco c., orrù p., pappalardo m., radtke u., renda p., romano p., sansò p., verrubbi v. (2005) markers of the last interglacial sea-level high stand along the coast of italy: tectonic implications. quat. int., 145/146, 3054. doi: 10.1016/j.quaint.2005.07.009 ferraro f. (2002) i riempimenti sedimentari delle cavità 177 pleistocene paleosols of italy: ... carsiche e dei ripari sottoroccia come memoria storica delle variazioni climatiche e paleoambientali del tardo pleistocene. unpublished phd thesis, university of milano, italy. ferraro f. (2009) age, sedimentation, and soil formation in the val sorda loess sequence, northern italy. quat. int., 204, 54-64. doi: 10.1016/j.quaint.2008.12.002 firpo m., guglielmin m., queirolo c. (2005) blockfields and blockstreams in the ligurian alps (mount beigua, italy). geogr. fis. dinam. quat., 28, 193204. firpo m., guglielmin m., queirolo c. (2006) relict blockfields in the ligurian alps (mount beigua, italy). permafr. periglac. process., 17, 71-78. doi: 10.1002/ppp.539 fitzpatrick e.a. (1984) micromorphology of soils. chapman and hall, london, pp. 433. fitzpatrick e.a. (1997) arctic soils and permafrost. in: woodin s.j., marquiss m. (eds.), ecology of arctic environments. british ecological society, special publication, 13, blackwell, oxford, uk, 1-39. fontana a., mozzi p., marchetti m. (2014) alluvial fans and megafans along the southern side of the alps. sedim. geol., 301, 150-171. doi: 10.1016/j.sedgeo.2013.09.003 frezzotti m., narcisi b. (1996) late quaternary tephraderived paleosols in central italy’s carbonate apennine range: stratigraphical and paleoclimatological implications. quat. int., 34-36, 147-153. doi: 10.1016/1040-6182(95)00079-8 frigerio c., bonadeo l., zerboni a., livio f., ferrario m.f., fioraso g., irace a., brunamonte f., michetti a.m. (2017) first evidence for late pleistocene to holocene earthquake surface faulting in the eastern monferrato arc (northern italy): geology, pedostratigraphy and structural study of the pecetto di valenza site. quat. int., 451, 143-164. doi: 10.1016/j.quaint.2016.12.022 giaccio b., rolfo m.f., bozzato s., galadini f., messina p., silvestrini m., sposato a. (2004) geoenvironmental and human response to the sub-orbital climatic oscillations of the ois3: geoarchaeological evidence from the colfiorito plain (central italy) la risposta ambientale ed umana alle oscillazioni climatiche sub-orbitali dell’ois3: evidenze geoarcheologiche dalla piana di colfiorito (appennino centrale). alpine and mediterranean quaternary, 17(2/1), 231-247. giraudi c., bodrato g., lucchi m.r., cipriani n., villa i.m., giaccio b., zuppi g.m. (2011) middle and late pleistocene glaciations in the campo felice basin (central apennines, italy). quaternary research, 75(1), 219-230. doi: 10.1016/j.yqres.2010.06.006 giraudi c., zanchetta g., sulpizio r. (2013) a latepleistocene phase of saharan dust deposition in the high apennine mountains (italy). alpine and mediterranean quaternary 26, 110-122. hirniak j.n., smith e.i., johnsen r., ren m., hodgkins j., orr c., negrino f., riel-salvatore j., fitch s., miller c.e., zerboni a., mariani g.s., harris j.a., gravel-miguel c., strait d., peresani m., benazzi s., marean c.w. (2020) discovery of cryptotephra at middle-upper paleolithic sites arma veirana and riparo bombrini, italy: a new link for broader geographic correlations. journal of quaternary science 35, 199-212. doi: 10.1002/jqs.3158 huang p.m., wang m.k. (1997) formation chemistry and selected surface properties of iron oxides. advances in geoecology, 30, 241-270. hoffman j., clark p.u., parnell a.c., he f. (2017) regional and global sea-surface temperatures during the last interglaciation. science, 355(6322), 276279. doi: 10.1126/science.aai84 ibanez j.j., bockheim j. (eds.) (2013) pedodiversity. crc press, boca raton, fl, usa, pp. 256. ifex-italian food excellence group, 2014. mountain potatoes. available at url: https://www.italianfo odexcellence.com/mountain-potatoes/ (accessed on february 25th, 2023). iuss working group wrb, 2022. world reference base for soil resources international soil classification system for naming soils and creating legends for soil maps. 4th edition. international union of soil sciences (iuss), vienna, austria, pp. 234. james w.c., mack g.h., monger h.c. (1998) paleosol classification. quat. int., 51 (52), 8-9. doi: 10.1016/s1040-6182(97)00043-8 kemp r.a. (1998) role of micromorphology in paleopedological research. quat. int., 51/52, 133-141. doi: 10.1016/s1040-6182(97)00040-2 kemp r.a. (1999) micromorphology of loess-paleosol sequences: a record of paleoenvironmental change. catena, 35(2-4), 179-196. doi: 10.1016/s0341-8162(98)00099-x krasilnikov p., garcía calderón n.e. (2006) a wrbbased buried paleosol classification. quat. int. 156/157, 176-188. doi: 10.1016/j.quaint.2006.05.009 laville h., rigaud j.p., sackett j. (1980) rock shelters of the perigord: geological stratigraphy and archaeological succession. academic press, cambridge. lehmkuhl f., nett j.j., pötter s., schulte p., sprafke t., jary z., antoine p., wacha l., wolf d., zerboni a., hošek j., marković s.b., obreht i., sümegi p., veres d., zeeden c., boemke b., schaubert v., viehweger j., hambach u. (2021) loess landscapes of europe mapping, geomorphology and zonal differentiation. earth-science reviews, 215, 103496. doi: 10.1016/j.earscirev.2020.103496 limondin-lozouet n., villa v., pereira a., nomade s., bahain j.-j., stoetzel e., aureli d., nicoud e. (2017) middle pleistocene molluscan fauna from the valle giumentina (abruzzo, central italy): palaeoenvironmental, biostratigraphical and biogeographical implications. quat. sci. rev., 156, 135149. doi: 10.1016/j.quascirev.2016.11.029 lisiecki l.e., raymo m.e. (2005) a pliocenepleistocene stack of 57 globally distributed benthic δ18o records. paleoceanography, 20, pa1003. 178 scarciglia f. et al. doi: 10.1029/2004pa001071. livio f., berlusconi a., michetti a.m., sileo g., zerboni a., trombino l., cremaschi m., mueller k., vittori e., carcano c., rogledi s. (2009) active faultrelated folding in the epicentral area of the december 25, 1222 (io=ix mcs) brescia earthquake (northern italy): seismotectonic implications. tectonophysics, 476, 320-335. doi: 10.1016/j.tecto.2009.03.019 livio f.a., berlusconi a., zerboni a., trombino l., sileo g., michetti a.m., spötl c. (2014) progressive offset and surface deformation along a seismogenic blind thrust in the po plain foredeep (southern alps, northern italy). j. geophys. res. solid earth, 199 (10), 7701-7721. doi: 10.1002/2014jb011112 livio f., ferrario f., frigerio c., zerboni a., michetti a.m. (2020) variable fault tip propagation rates affected by near-surface lithology and implications for fault displacement hazard assessment. journal of structural geology, 130, 103914. doi: 10.1016/j.jsg.2019.103914 liu f., colombo, c, adamo p., he j.z., violante a. (2002) trace elements in manganese-iron nodules from a chinese alfisol. soil science society of america journal 66, 661-670. doi: 10.2136/sssaj2002.6610 longhi a., trombino l., guglielmin m. (2021) soil micromorphology as tool for the past permafrost and paleoclimate reconstruction. catena, 207, 105628. doi: 10.1016/j.catena.2021.105628 macphail r.i., goldberg p. (2017) applied soils and micromorphology in archaeology. cambridge university press, cambridge. doi: 10.1017/9780511895562 magaldi d. (1983) calcareous crust (caliche) genesis in some mollisols and alfisols from southern italy: a micromorphological approach. in: proceedings of the soil micromorphology. international working meeting on soil micromorphology, 6, 623-636. magaldi d., tallini m. (2000) a micromorphological index of soil development for the quaternary geology research. catena, 41(4), 261-276. doi: 10.1016/s0341-8162(00)00096-5 magaldi d., giammatteo m. (2008) microstrutture della crosta calcarea laminare (orizzonte petrocalcico) di due paleosuoli pleistocenici nell’agro di cerignola (foggia). alpine and mediterranean quaternary, 21, 423-432. magliulo p., terribile f., colombo c., russo f. (2006) a pedostratigraphic marker in the geomorphological evolution of the campanian apennines (southern italy): the paleosol of eboli. quat. int., 156/157, 97-117. doi: 10.1016/j.quaint.2006.05.006 marcolla, a., miola, a., mozzi, p., monegato g., asioli a., pini, r., stefani, c. (2021) middle pleistocene to holocene palaeoenvironmental evolution of the south-eastern alpine foreland basin from multiproxy analysis. quat. sci. rev., 259, 106908. doi: 10.1016/j.quascirev.2021.106908 mariani g.s., muntoni i.m., zerboni a. (2020) the eneolithic/bronze age transition at tegole di bovino (apulia): geoarchaeological evidence of climate change and land-use shift. quaternary, 3, 14, 123. doi: 10.3390/quat3020014 marinari s., moscatelli m.c., fiordelmondo f., marabottini r., di buduo g.m., vianello g. (2017) preliminary evidences of a paleosol in the living landscape of civita di bagnoregio (italy). eqa international journal of environmental quality, 24, 3945. doi: 10.6092/issn.2281-4485/7289 masseroli a., bollati i.m., trombino l., pelfini m. (2022) the soil trail of buscagna valley, an example of the role of soil science in geodiversity and geoheritage analyses. geological society of london, special publications, 530. doi: 10.1144/sp530-2022-110 mirabella a., egli m., raimondi s., giaccai d. (2005) origin of clay minerals in soils on pyroclastic deposits in the island of lipari (italy). clays clay miner. 53(4), 409-421. doi: 10.1346/ccmn.2005.0530409 morelli a., bruno l., cleveland d.m., drexler t.m., amorosi a. (2017) reconstructing last glacial maximum and younger dryas paleolandscapes through subsurface paleosol stratigraphy: an example from the po coastal plain, italy. geomorphology, 295, 790-800. doi: 10.1016/j.geomorph.2017.08.013 moser d., di pasquale g., scarciglia f., nelle o. (2017) holocene mountain forest changes in central mediterranean: soil charcoal data from the sila massif (calabria, southern italy). quat. int., 457, 113-130. doi: 10.1016/j.quaint.2017.01.042 mozzi p., bini c., zilocchi l., becattini r., lippi m.m. (2003) stratigraphy, palaeopedology and palynology of late pleistocene and holocene deposits in the landward sector of the lagoon of venice (italy), in relation to the caranto level. alpine and mediterranean quaternary, 16(1bis), 193-210. muntoni i.m., zerboni a. (2017) analisi geoarcheologiche sui livelli del neolitico antico del pulo di molfetta fondo azzolini. in: radina f., (ed.), atti della xlvii riunione scientifica preistoria e protostoria della puglia, studi di storia e protostoria, 4, iipp, firenze, 751-756. nacsn (north american commission on stratigraphic nomenclature) (1983) north american stratigraphic code. the american association of petroleum geologists bulletin, 67(5), 841-875. nacsn (north american commission on stratigraphic nomenclature) (2021) north american stratigraphic code. stratigraphy, 18(3), 153-204. napoli r., costantini e.a.c., d’egidio g. (2006) using pedostratigraphic levels and a gis to generate three-dimensional maps of the quaternary soil cover and reconstruct the geomorphological development of the montagnola senese (central italy). quat. int., 156/157, 167-175. doi: 10.1016/j.quaint.2006.05.010 negri s., raimondo e., d'amico m.e., stanchi s., basile a., bonifacio e. (2021) loess-derived polygenetic 179 pleistocene paleosols of italy: ... https://doi.org/10.1144/sp530-2022-110 soils of north-western italy: a deep characterization of particle size, shape and color to draw insights about the past. catena, 196, 104892. doi: 10.1016/j.catena.2020.104892 nesbitt, h.v., young, g.m. (1982) early proterozoic climates and plate motions inferred from major elemnt chemistry of lutites. nature, 299, 715-717. doi: 10.1038/299715a0 nettleton w.d., brashears b.r., benham e.c., ahrens r.j. (1998) a classification system for buried paleosols. quat. int., 51/52, 175-183. doi: 10.1016/s1040-6182(97)00043-8 nettleton w.d., olson c.g., wysocki d.a. (2000) paleosol classification: problems and solutions. catena, 41, 61-92. doi: 10.1016/s0341-8162(00)00109-0 nicoud e., aureli d., pagli m., villa v., chaussé c., agostini s., bahain j.-j., boschian g., degeai j.p., fusco f., giaccio b., hernandez m., kuzucuoglu c., lahaye c., lemorini c., limondinlozouet n., mazza p., mercier n., nomade s., pereira a., robert v., rossi m.a., virmoux c., zupancich a. (2016) preliminary data from valle giumentina pleistocene site (abruzzo, central italy): a new approach to a clactonian and acheulian sequence. quat. int., 409, 182-194. doi: 10.1016/j.quaint.2015.08.080 pascucci v., sechi d., andreucci s. (2014) middle pleistocene to holocene coastal evolution of nw sardinia (mediterranean sea, italy). quat. int., 328 -329(1), 3-20. doi: 10.1016/j.quaint.2014.02.018 peccerillo a. (2005) plio-quaternary volcanism in italy. petrology, geochemistry, geodynamics. springer, berlin, pp. 365. pelle t., scarciglia f., di pasquale g., allevato e., marino d., robustelli g., la russa m.f., pulice i. (2013) multidisciplinary study of holocene archaeological soils in an upland mediterranean site: natural versus anthropogenic environmental changes at cecita lake, calabria, italy. quat. int., 303, 163-179. doi: 10.1016/j.quaint.2013.04.003 pereira a., monaco l., marra f., nomade s., gaeta m., leicher n., palladino d.m., sottili g., guillou h., scao v., giaccio b. (2020) tephrochronology of the central mediterranean mis 11c interglacial (∼425-395 ka): new constraints from the vico volcano and tiber delta, central italy. quat. sci. rev., 243, 106470, 1-23. doi: 10.1016/j.quascirev.2020.106470 peresani m., nicosia c. (2015) comparative study of two late pleistocene sequences with paleosols and aeolian deposits at the southern alpine foreland. geogr. fis. dinam. quat., 38 (1), 41-53. doi: 10.4461/gfdq.2015.38.05 peresani m., cremaschi m., ferraro f., falgueres c., bahain j.-j., gruppioni g., sibilia e., quarta g., calcagnile l., dolo j.-m. (2008) age of the final middle palaeolithic and uluzzian levels at fumane cave, northern italy, using 14c, esr, 234u/230th and thermoluminescence methods. journal of archaeological science 35, 2986-2996. doi: 10.1016/j.jas.2008.06.013 perini s., muttoni g., livio f., zucali m., michetti a.m., zerboni a. (2023) high-resolution magnetochronology detects multiple stages of pleistocene tectonic uplift and deformation in the po plain of northern italy. quat. res., 1-15. doi: 10.1017/qua.2022.67 pintaldi e., d'amico m.e., colombo n., martinetto e., said-pullicino d., giardino m., freppaz m. (2021) hidden paleosols on a high-elevation alpine plateau (nw italy): evidence for lateglacial nunatak? global and planetary change, 207, 103676. doi: 10.1016/j.gloplacha.2021.103676 polynov b.b. (1927) contributions of russian scientists to paleopedology. russian pedological investigations, u.s.s.r. academy of sciences, leningrad, 8, pp. 32. quènard l., samouëlian a., laroche b., cornu s. (2011) lessivage as a major process of soil formation: a revisitation of existing data. geoderma 167/168, 135-147. doi: 10.1016/j.geoderma.2011.07.031 raab g., halpern d., scarciglia f., raimondi s., norton k., pettke t., hermann j., de castro portes r., aguilar sanchez a.m., egli m. (2017) linking tephrochronology and soil characteristics in the sila and nebrodi mountains, italy. catena, 158, 266-285. doi: 10.1016/j.catena.2017.07.008 raab g., scarciglia f., norton k., dahms d., brandová d., de castro portes r., christl m., ketterer m.e., ruppli a., egli m. (2018) denudation variability of the sila massif upland (italy) from decades to millennia using 10be and 239+240pu. land degradation and development, 29, 3736-3752. doi: 10.1002/ldr.3120 rellini i., trombino l., firpo m., rossi p.m. (2009) extending westward the loess basin between the alps and the mediterranean region: micromorphological and mineralogical evidences from the northern slope of the ligurian alps, northern italy. geogr. fis. dinam. quat., 32(1), 103-116. rellini i., trombino l., rossi p.m., firpo m. (2014) frost activity and ice segregation in a palaeosol of the ligurian alps (beigua massif, italy): evidence of past permafrost? geogr. fis. dinam. quat., 37 (1), 29-42. doi: 10.4461/gfdq.2014.37.4 rellini i., trombino l., carbone c., firpo m. (2015) petroplinthite formation in a pedosedimentary sequence along a northern mediterranean coast: from micromorphology to landscape evolution. journal of soils and sediments, 15(6), 1311-1328. doi: 10.1007/s11368-014-0896-2 retallack g.j. (2005) pedogenic carbonate proxies for amount and seasonality of precipitation in paleosols. geology, 33, 333-336. doi: 10.1130/g21263.1 robustelli g., muto f., scarciglia f., spina v., critelli s. (2005a) eustatic and tectonic control on late quaternary alluvial fans along the tyrrhenian sea coast of calabria (south italy). quat. sci. rev., 24 (18-19), 2101-2119. 180 scarciglia f. et al. doi: 10.1016/j.quascirev.2004.08.025 robustelli g., scarciglia f., muto f. (2005b) sedimentology and fabric characteristics of subaerial slope and alluvial cone deposits in northern calabria (southern italy). geogr. fis. dinam. quat., 28(2), 219-227. robustelli g., lucà f., corbi f., pelle t., dramis f., fubelli g., scarciglia f., muto f., cugliari d. (2009) alluvial terraces on the ionian coast of northern calabria, southern italy: implications for tectonic and sea level controls. geomorphology, 106(3-4), 165-179. doi: 10.1016/j.geomorph.2008.12.010 rossignol-strick m. (1999) the holocene climatic optimum and pollen records of sapropel 1 in the eastern mediterranean, 9000-6000 bp. quat. sci. rev., 18, 515-530. doi: 10.1016/s0277-3791(98)00093-6 russo ermolli e., masi a., vignola c., di lorenzo h., masci l., bona f., forti l., lembo g., mazzini i., mecozzi b., muttillo b., pieruccini p., sardella r., sadori l. (2022) the pollen record from grotta romanelli (apulia, italy): new insight for the late pleistocene mediterranean vegetation and plant use. review of palaeobotany and palynology, 297, 104577. doi: 10.1016/j.revpalbo.2021.104577 sauer d. (2010) approaches to quantify progressive soil development with time in mediterranean climate i. use of field criteria. journal of plant nutrition and soil science, 173, 822-842. doi: 10.1002/jpln.201000136 sauer d. (2015) pedological concepts to be considered in soil chronosequence studies. soil research, 53, 577-591. doi: 10.1071/sr14282 sauer d. (2017) soil development: numerical indices. in: richardson d., castree n., goodchild m.f., kobayashi a., liu w., marston, r.a. (2017) the international encyclopedia of geography. john wiley & sons, ltd. doi: 10.1002/9781118786352.wbieg0909 sauer d., wagner s., brückner h., scarciglia f., mastronuzzi g., stahr k. (2010) soil development on marine terraces near metaponto (gulf of taranto, southern italy). quat. int., 222, 48-63. doi: 10.1016/j.quaint.2009.09.030 sauer d., schülli-maurer i., wagner s., scarciglia f., sperstad r., svendgård-stokke s., sørensen r., schellmann g. (2015) soil development over millennial timescales a comparison of soil chronosequences of different climates and lithologies. iop conference series: earth and environmental science, 25(1), 012009, 1-19. doi: 10.1088/1755-1315/25/1/012009 sauro u., ferrarese f., francese r., miola a., mozzi p., quario rondo g., trombino l., valentini g. (2009) doline fills case study of the faverghera plateau (venetian prealps, italy). acta carsologica, 38 (1), 51-63. scalenghe r., certini g., corti g., zanini e., ugolini f.c. (2004) segregated ice and liquefaction effects on compaction of fragipans. soil science society of america journal, 68, 204-214. doi: 10.2136/sssaj2004.2040 scarciglia f., barca d. (2017) a powerful tool for assessing distribution and fate of potentially toxic metals (ptms) in soils: integration of laser ablation spectrometry (la-icp-ms) on thin sections with soil micromorphology and geochemistry. environmental science and pollution research, 24(10), 9776-9790. doi: 10.1007/s11356-017-8654-9 scarciglia f., terribile f., colombo c. (2003a) micromorphological evidence of paleoenvironmental changes in northern cilento (south italy) during the late quaternary. catena, 54(3), 515-536. doi: 10.1016/s0341-8162(03)00124-3 scarciglia f., terribile f., colombo c., cinque a. (2003b) late quaternary climatic changes in northern cilento (southern italy): an integrated geomorphological and paleopedological study. quat. int., 106-107, 141-158. doi: .1016/s1040-6182(02)00169-6 scarciglia f., pulice i., robustelli g., vecchio g. (2006) soil chronosequences on quaternary marine terraces along the northwestern coast of calabria (southern italy). quat. int., 156-157, 133-155. doi: 10.1016/j.quaint.2006.05.027 scarciglia f., le pera e., critelli s. (2007) the onset of the sedimentary cycle in a midlatitude upland environment: weathering, pedogenesis, and geomorphic processes on plutonic rocks (sila massif, calabria). in: arribas j., critelli s., johnsson m.j. (eds.), sedimentary provenance and petrogenesis: perspectives from petrography and geochemistry. geological society of america special paper 420, 149-166. doi: 10.1130/2006.2420(10) scarciglia f., de rosa r., vecchio g., apollaro c., robustelli g., terrasi f. (2008) volcanic soil formation in calabria (southern italy): the cecita lake geosol in the late quaternary geomorphological evolution of the sila uplands. journal of volcanology and geothermal research, 177, 101-117. doi: 10.1016/j.jvolgeores.2007.10.014 scarciglia f., barca d., de rosa r., pulice i. (2009) application of laser ablation icp-ms and traditional micromorphological techniques to the study of an alfisol (sardinia, italy) in thin sections: insights into trace element distribution. geoderma, 152(1-2), 113-126. doi: 10.1016/j.geoderma.2009.05.021 scarciglia f., tuccimei p., vacca a., barca d., pulice i., salzano r., soligo m. (2011) soil genesis, morphodynamic processes and chronological implications in two soil transects of se sardinia, italy: traditional pedological study coupled with laser ablation icp-ms and radionuclide analyses. geoderma, 162(1-2), 39-64. doi: 10.1016/j.geoderma.2011.01.004 scarciglia f., zumpano v., sulpizio r., terribile f., pulice i., la russa m.f. (2014) major factors controlling late pleistocene to holocene soil development in the vesuvius area (southern italy). european journal of soil science, 65, 406-419. 181 pleistocene paleosols of italy: ... doi: 10.1111/ejss.12150 scarciglia f., pelle t., pulice i., robustelli g. (2015) a comparison of quaternary soil chronosequences from the ionian and tyrrhenian coasts of calabria, southern italy: rates of soil development and geomorphic dynamics. quat. int., 376, 146-162. doi: 10.1016/j.quaint.2014.01.009 scarciglia f., critelli s., borrelli l., coniglio s., muto f., perri f. (2016) weathering profiles in granitoid rocks of the sila massif uplands, calabria, southern italy: new insights into their formation processes and rates. sedim. geol. 336, 46-67. doi: 10.1016/j.sedgeo.2016.01.015 scarciglia f., mercatante g., fondevilla v., anadón p., oms o., donato p., agnini c., papini m., rook l., ghinassi m. (2018) pleistocene paleosol development and paleoenvironmental dynamics in east africa: a multiproxy record from the homo-bearing aalat pedostratigraphic succession, dandieo basin (eritrea). quat. sci. rev., 191, 275-298. doi: 10.1016/j.quascirev.2018.05.015 scarciglia f., nicolaci a., del bianco s., pelle t., soligo m., tuccimei p., marzaioli f., passariello i., iovino f. (2020) reforestation and soil recovery in a mediterranean mountain environment: insights into historical geomorphic and vegetation dynamics in the sila massif, calabria, southern italy. catena, 194, 104707, 1-20. doi: 10.1016/j.catena.2020.104707 schwertmann u., taylor r.m. (1989) iron oxides. in: dixon j.b., weed s.b. (eds.), minerals in soil environments, 2nd ed. soil science society of america, madison, wisconsin, usa, 379-438. soil survey staff (2014) soil survey field and laboratory methods manual. soil survey investigations report no. 51, version 2.0., burt r. and soil survey staff (eds.), u.s. department of agriculture (usda), natural resources conservation service (nrcs), lincoln, ne, pp. 457. spinapolice e.e., zerboni a., meyer m.c., talamo s., mariani g.s., gliganic l.a., buti l., fusco m., maiorano m.p., silvestrini s., sorrentino r., vazzana a., romandini m., fiorini a., curci a., benazzi s. (2022) back to uluzzo archaeological, palaeoenvironmental and chronological context of the mid-upper palaeolithic sequence at uluzzo c rock shelter (apulia, southern italy). journal of quaternary science, 37(2), 217-234. doi: 10.1002/jqs.3349 tallini m., lo sardo l., spadi m. (2020) seismic site characterisation of red soil and soil-building resonance effects in l’aquila downtown (central italy). bulletin of engineering geology and the environment, 79 (8), 4021-4034. doi: 10.1007/s10064-020-01795-x tiedemann r., sarnthein m., shackleton n.j. (1994) astronomic timescale for the pliocene atlantic δ18o and dust flux records of odp site 659. paleoceanography, 9, 619-638. doi: 10.1029/94pa00208 torrent j., schwertmann u., schulze d.j. (1980) iron oxide mineralogy of some soils of two river terrace sequences in spain. geoderma, 23, 191-208. doi: 10.1016/0016-7061(80)90002-6 torrent j., schwertmann u., fechter h., alferez f. (1983) quantitative relationships between soil color and hematite content. soil sci., 136 (6), 354358. trombino l., ferraro f. (2002) terra rossa paleosols on the prealpine border. the study case of mount casto (val sabbia, brescia northern italy) paleosuoli tipo terra rossa al margine prealpino. il caso di studio del monte casto (val sabbia brescia). alpine and mediterranean quaternary, 15(1), 131-140, vacca a., adamo p., pigna m., violante p. (2003) genesis of tephra-derived soils from the roccamonfina volcano, south central italy. soil science society of america journal, 67, 198-207. doi: 10.2136/sssaj2003.1980 van otterloo r.h., sevink j. (2021) soils and soilscapes of the upper volturno basin: a detailed survey of a large intermontane basin in the centralsouthern apennines, italy. journal of maps, 17(2), 63-72. doi: 10.1080/17445647.2021.1875064 van vliet-lanoë b. (1998) frost and soils: implications for paleosols, paleoclimates and stratigraphy. catena, 34, 157-183. doi: 10.1016/s0341-8162(98)00087-3 van vliet-lanoë b., fox c.a. (2018) frost action. in: stoops g., marcelino v., mees f. (eds.), interpretation of micromorphological features of soils and regoliths (2nd ed.), elsevier, oxford, 575-603. verrecchia e.p., trombino l. (2021) pedofeatures associated to soil processes. in: a visual atlas for soil micromorphologists. springer, cham., pp 135149. doi: 10.1007/978-3-030-67806-7_5 villa v., pereira a., chaussé c., nomade s., giaccio b., limondin-lozouet n., fusco f., regattieri e., degeai j.-p., robert v., kuzucuoglu c., boschian g., agostini s., aureli d., pagli m., bahain j.-j., nicoud e. (2016a) a mis 15-mis 12 record of environmental changes and lower palaeolithic occupation from valle giumentina, central italy. quat. sci. rev., 151, 160-184. doi: 10.1016/j.quascirev.2016.09.006 villa v., virmoux c., chaussé c., degeai j.-p., robert v., kuzucuoglu c., boschian g., agostini s., aureli d., pagli m., nicoud e. (2016b) the long sedimentary succession of the valle giumentina basin (abruzzo, central italy): new evidence from stratigraphic studies and electrical resistivity tomography (ert). alpine and mediterranean quaternary, 29(2), 193-199. vogel s., märker m., rellini i., hoelzmann p., wulf s., robinson m., steinhübel l., di maio g., imperatore c., kastenmeier p., liebmann l., esposito d., seiler f. (2016) from a stratigraphic sequence to a landscape evolution model: late pleistocene and holocene volcanism, soil formation and land use in the shade of mount vesuvius (italy). quat. int., 394, 155-179. doi: 10.1016/j.quaint.2015.02.033 wagner s., costantini e.a.c., sauer d., stahr k. (2007) 182 scarciglia f. et al. soil genesis in a marine terrace sequence of sicily, italy. revista mexicana de ciencias geologicas, 24(2), 247-260. white g.n., dixon j.b. (1996) iron and manganese distribution in nodules from a young texas vertisol. soil science society of america journal, 6, 1254-1262. doi: 10.2136/sssaj1996.03615995006000040042x zambaldi m. (2020) tra pleistocene medio e superiore nell’italia nord-occidentale: geoarcheologia di ciota ciara (vc) e balzi rossi museo (im). tesi di dottorato, università degli studi di trento, italy. zanchetta g., bini m., giaccio b., manganelli g., benocci a., regattieri e., colonese a.c., boschi c., biagioni c. (2017) middle pleistocene (mis 14) environmental conditions in the central mediterranean derived from terrestrial molluscs and carbonate stable isotopes from sulmona basin (italy). palaeogeography, palaeoclimatology, palaeoecology, 485, 236-246. doi: 10.1016/j.palaeo.2017.06.016 zembo i. (2010) stratigraphic architecture and quaternary evolution of the val d'agri intermontane basin (southern apennines, italy). sedim. geol., 223(34), 206-234. doi: 10.1016/j.sedgeo.2009.11.011 zembo i., trombino l., bersezio r., felletti f., dapiaggi m. (2012) climatic and tectonic controls on pedogenesis and landscape evolution in a quaternary intramontane basin (val d'agri basin, southern apennines, italy). journal of sedimentary research, 82(5), 283-309. doi: 10.2110/jsr.2012.22 zerboni a., trombino l., cremaschi m, (2011) micromorphological approach to polycyclic pedogenesis on the messak settafet plateau (central sahara): formative processes and palaeoenvironmental significance. geomorphology, 125, 319-335. doi: 10.1016/j.geomorph.2010.10.015 zerboni a., trombino l., frigerio c., livio f., berlusconi a., michetti a.m., rodnight h., spötl c. (2015) the loess-paleosol sequence at monte netto: a record of climate change in the upper pleistocene of the central po plain, northern italy. j. soils sedim., 15, 1329-1350. doi: 10.1007/s11368-014-0932-2 zerboni a., amit r, baroni c., coltorti m., ferrario m.f., fioraso g., forno m.g., frigerio c., gianotti f., irace a., livio f., mariani g.s., michetti a.m., monegato g., mozzi p., orombelli g., perego a., porat n., rellini i., trombino l., cremaschi m. (2018) towards a map of the upper pleistocene loess of the po plain loess basin (northern italy). alpine and mediterranean quaternary, 31, 253256 zucca c., andreucci s., akşit t., koca y.k, madrau s., pascucci v., previtali f., shaddad s.m., kapur s. (2014a) buried palaeosols of nw sardinia (italy) as archives of the late quaternary climatic fluctuations. catena, 122, 72-90. doi: 10.1016/j.catena.2014.06.005 zucca, c., sechi, d., andreucci, s., shaddad s.m., deroma m., madrau s., previtali f., pascucci, v., kapur, s. (2014b) pedogenic and palaeoclimatic evidence from an eemian calcrete in north-western sardinia (italy). european journal of soil science, 65(4), 420-435. doi: 10.1111/ejss.12144 zuffetti c., bersezio r. (2021) space-time geological model of the quaternary syntectonic fill of a foreland basin (po basin, northern italy). sedim. geo., 421, 105945. doi: 10.1016/j.sedgeo.2021.105945 zuffetti c., trombino, l., zembo i., bersezio r. (2018) soil evolution and origin of landscape in a late quaternary tectonically mobile setting: the po plain-northern apennines border in lombardy (italy). catena, 171, 376-397. doi: 10.1016/j.catena.2018.07.026 183 ms. received: february 3, 2023 revised: may 8, 2023 accepted: may 9, 2023 available online: may 19, 2023 pleistocene paleosols of italy: ... imp.lugli& composizione dei sedimenti sabbiosi nelle perforazioni lungo il tracciato ferroviario ad alta velocità: indicazioni preliminari sull’evoluzione sedimentaria della media pianura modenese stefano lugli, simona marchetti dori, daniela fontana & filippo panini dipartimento di scienze della terra, università degli studi di modena e reggio emilia, largo s. eufemia 19, 41100 modena. e-mail: lugli.stefano@unimore.it, marchettidori.simona@unimore.it, fontana.daniela@unimore.it, panini.filippo@unimore.it riassunto: lugli s. et al., composizione dei sedimenti sabbiosi nelle perforazioni lungo il tracciato ferroviario ad alta velocità: indicazioni preliminari sull’evoluzione sedimentaria della media pianura modenese. (it issn 0394-3356, 2004). le perforazioni effettuate lungo il tratto modenese del tracciato ferroviario ad alta velocità hanno fornito numerosi campioni di sabbie prelevate in profondità fino a 40-50 m dal piano campagna, per un intervallo temporale che presumibilmente copre il pleistocene sommitale e l’olocene. l’esame composizionale di 28 campioni di sabbie prelevati da 6 perforazioni ha permesso di evidenziare come la sedimentazione fluviale nella media pianura modenese sia drasticamente mutata a partire da circa 10-12 ka. la composizione dei sedimenti sabbiosi più recenti sembra riconducibile a quella dei corsi d’acqua minori che attraversano oggi la pianura nel tratto compreso tra i fiumi secchia e panaro. i sedimenti sabbiosi più antichi presentano invece composizioni diverse, particolarmente arricchite in feldspati. tali differenze composizionali possono riferirsi a combinazioni di vari fattori quali: a) variazioni nella litologia del substrato per fenomeni tettonici e/o per variazioni nello sviluppo del reticolo idrografico, b) fenomeni di riciclo di sedimenti fluviali antichi, c) effetti di alterazione per variazioni climatiche. i dati composizionali acquisiti, uniti a dati di tipo stratigrafico, suggeriscono che tra i sedimenti tardo-pleistocenici e quelli olocenici sia presente una significativa discontinuità stratigrafica di importanza regionale. abstract: lugli s. et al., composition of sands in cores along the high-speed rail (tav): preliminary indications on the sedimentary evolution of the modena plain. (it issn 0394-3356, 2004). the modena alluvial plain has been geologically investigated in great detail and is characterized by a spectacular abundance of archaeological sites of various age. for this reasons the area may be considered a natural laboratory for the reconstruction of the recent sedimentary evolution of the po plain. the alluvial plain area examined for this study has an approximate extent of 150 km2 and is located at the northern side of the northern apennines thrustand fold-belt, where streams draining the chain flow toward the northeast into the po river. detailed modal analyses by point-counting of thin sections show that modern stream sands in the modena plain show similar overall compositional fields, but can be discriminated on the base of key-components, such as quartz, feldspar, carbonate and lithic fragments. the study of sand sediments indicates that the compositional fields have not varied significantly since the neolithic. the only major diagenetic process is the formation of carbonate concretions (caliche), which can be easily recognized as secondary particles during point counting of thin sections. these results indicate that the reconstruction of the recent evolution of the local drainage system is possible by comparing ancient with modern fluvial sand compositions. the drilling of numerous wells along the new high speed train tract (tav) provided us with new insight on the sedimentary evolution of the plain through time. the samples recovered from 6 wells reaching depths up to -50 m show that the sand sediments older than 1012 kyr, have a significant shift in composition from the modern ones. this compositional change consists in a marked overall increase of quartz and feldspar components. the compositional variations can be explained by the combination of various factors: a) significant change in the bedrock lithology through time induced by tectonics and/or change in the local drainage pattern, and b) recycling of older fluvial sediments enriched in feldspar. because the sands older than 10-12 kyr compared to the overlaying olocenic and modern sediments are enriched in feldspar, which is considered a particularly alterable component, the compositional differentiation can be related to effects induced to glacial-interglacial climate changes but not to post-depositional diagenetic processes. the considerable change in sand composition and the stratigraphy of the deposits suggest dramatic geographical, environmental and depositional variations supporting the observation that a regional unconformity separates the late pleistocene from the olocene sediments. parole chiave: depositi fluviali, quaternario, pianura padana, composizione sabbie. keywords: fluvial sediments, quaternary, po plain, sand composition. il quaternario italian journal of quaternary sciences 17(2/1), 2004, 379-389 1. introduzione la pianura modenese, per la particolare abbondanza di siti archeologici e di sondaggi geognostici, rappresenta un laboratorio naturale per lo studio dell’evoluzione sedimentaria della pianura padana. alla ricca documentazione già disponibile, si aggiunge la notevole mole di dati di sottosuolo acquisita recentemente in occasione della realizzazione del tracciato ferroviario ad alta velocità. il presente lavoro illustra i primi dati composizionali ottenuti analizzando campioni di sabbie provenienti da perforazioni effettuate lungo tale tracciato. lo scopo è quello di fornire un contributo alla comprensione della complessa evoluzione sedimentaria del settore modenese della pianura padana (fig.1). indagini di dettaglio da noi recentemente effettuate (lugli et al., 2003), hanno permesso di individuare specifiche petrofacies caratterizzanti le sabbie attuali e recenti dei principali corsi d’acqua modenesi in funzione di alcuni parametri composizionali (quarzo+feldspati, 380 s. lugli et al. carbonati totali, frammenti litici). tale studio ha inoltre dimostrato che la composizione delle sabbie si è mantenuta pressoché costante a partire dal neolitico. questi risultati hanno fornito uno strumento importante per l’indagine dei sedimenti sabbiosi nel sottosuolo modenese, per l’identificazione degli apparati fluviali di pertinenza e della loro evoluzione. le perforazioni lungo il tracciato tav si sono rivelate una utile occasione per effettuare un confronto con i dati già in nostro possesso sulle composizioni delle sabbie dei corsi d’acqua modenesi, al fine di ottenere informazioni più complete sull’evoluzione della sedimentazione fluviale nel settore meridionale della pianura padana. 2. inquadramento stratigrafico dell’alta e media pianura le alternanze di peliti e di depositi conglomeratico-sabbiosi di ambiente alluvionale che caratterizzano la pianura emiliano-romagnola sono il risultato di cicli deposizionali che si sviluppano a partire dal pleistocene medio (da circa 650 ka) su di una superficie di discontinuità stratigrafica che li separa dai più antichi depositi di ambiente litorale. lo sviluppo di questa superficie è legata ad un sollevamento regionale che, nei settori prossimi al margine appenninico, ha il carattere di una superficie di erosione subaerea (regione emiliaromagna & eni-agip, 1998). a scala regionale, all’interno dei depositi continentali quaternari sono stati riconosciuti due principali cicli, corrispondenti a due unità, o a unità a limiti inconformi (sintema emiliano-romagnolo inferiore e superiore (amorosi & farina, 1994; 1995; regione emilia-romagna & eni-agip, 1998; gasperi & pizziolo, in stampa) separate da una discontinuità stratigrafica collocabile tra 350 e 450 ka (regione emiliaromagna & eni-agip, 1998), connessa ad un ulteriore episodio di sollevamento della catena (fig. 2). questi due sintemi sono stati ulteriormente suddivisi in unità di rango inferiore la cui organizzazione verticale riflette lo sviluppo di un ciclo trasgressivo-regressivo. il riconoscimento di queste unità di rango inferiore è agevole nell’alta pianura, dove sui depositi grossolani sono presenti paleosuoli più o meno sviluppati. nella media e bassa pianura invece, l’assenza di interruzioni prolungate nella sedimentazione, oltre al mancato o limitato sviluppo di pedogenesi ed un minor contrasto litologico, rendono difficile la loro definizione (gasperi & pizziolo, in stampa). a scala regionale, il più recente ciclo trasgressivoregressivo completo (subsintema di villa verucchio) è suddiviso in una porzione pelitica (unità di niviano), deposta durante la penultima fase interglaciale alla quale segue, nelle aree a ridosso del margine appenninico, e fino all’altezza della via emilia (fig. 3), una potente porzione grossolana (unità di vignola), corrispondente alla successiva fase glaciale e deposta durante un intervallo cronologico antecedente 15-18 ka. esso è ritenuto genericamente più antico di 30 ka (gasperi & pizziolo, in stampa), anche se la possibile correlazione con un orizzonte grossolano presente nell’appennino bolognese fa supporre una età della base non più antica di 20-23 ka (amorosi et al., 1996). nella pianura emiliana, la sedimentazione tardofig. 1 idrografia principale dell’alta e media pianura modenese e traccia del percorso della linea tav. e’ illustrata la distribuzione dei corpi ghiaiosi che costituiscono le conoidi pedemontane tardo-pleistoceniche dei fiumi secchia e panaro e del t. tiepido (modificata da pellegrini & zavatti, 1979). i = sezione geologica di fig. 4; ii = sezione geologica di fig. 5; iii = sezione geologica di fig. 6. schematic hydrography of the modena alluvial plain crossed by the new high speed train tract (tav). the late pleistocene piedimont gravel fans of the secchia, panaro and tiepido streams are illustrated (modified from pellegrini & zavatti 1979). i = geological section of fig. 4; ii = geological section of fig. 5; iii = geological section of fig. 6. fig. 2 schema stratigrafico dei depositi continentali quaternari della pianura emiliano-romagnola (modificata da regioneemilia-romagna & eni-agip, 1998; gasperi & pizziolo, in stampa). le sigle a0-4 si riferiscono alle unità idrostratigrafiche distinte in regione-emilia-romagna & eni-agip (1998). stratigraphic sketch of the quaternary continental deposits in the emilia romagna plain (modified from regione-emiliaromagna & eni-agip, 1998; gasperi & pizziolo, in press). the abbreviations a0-4 refer to the hydrostratigraphic units of regione-emilia-romagna & eni-agip (1998). pleistocenica ed olocenica è rappresentata da depositi di piana alluvionale (subsintema di ravenna), ad esclusione delle aree prossime al margine appenninico, dove sono presenti corpi ghiaioso-sabbiosi (depositi di canali intrecciati, fig. 3). nella media pianura modenese questa unità a limiti inconformi è caratterizzata da una parte inferiore, tra 15 ed 25 m di profondità dal piano campagna, ricca di materia organica (depositi di palude o di piana alluvionale mal drenata) con una età radiometrica tra 15 e 10 ka (gasperi & pizziolo, in stampa). un altro orizzonte ricco di materia organica, si rinviene al di sopra del precedente, tra 7,5 e 11 m di profondità ed ha fornito età radiometriche intorno a 4 ka. gli scavi e le perforazioni eseguite nell’area cittadina hanno documentato la presenza entro i l subsintema di ravenna di una unità stratigrafica superiore (unità di modena) costituita dai sedimenti alluvionali pelitici deposti dopo l’età romana, ed in prevalenza durante la crisi climatica databile all’alto medioevo (fig. 3). l’unità, potente 5-8 m si sovrappone ad una superficie pedogenetica poco sviluppata e si ritiene sia stata prodotta dalle esondazioni di un corso d’acqua minore (t. fossa-cerca o formigine) che scorreva nei pressi della città in epoca storica (gasperi et al., 1989; cremaschi & gasperi, 1989; fazzini & gasperi, 1996; gasperi & pizziolo, in stampa). nelle zone a nord di modena, l’identificazione delle unità a limiti inconformi precedentemente citate risulta più difficile a causa della mancanza di orizzonti ghiaiosi correlabili a quelli della media ed alta pianura. i profili geologici trasversali lungo la media pianura modenese attualmente disponibili sono illustrati in fig. 4 e 5. dal loro esame è possibile determinare l’orizzonte ghiaioso corrispondente all’unità di vignola e separarlo dai depositi sovrastanti dove le ghiaie passano alle alternanze di sabbie e limi del subsintema di ravenna. come si evince dalla estensione delle conoidi ghiaiose tardo-pleistoceniche (fig. 1), le ghiaie presenti nel sottosuolo cittadino sono probabilmente attribuibili al f. secchia. solo un corso d’acqua con un considerevole bacino idrografico e con una efficienza di trasporto elevata può infatti aver trasportato depositi ghiaiosi fino a molti chilometri oltre lo sbocco vallivo. più a nord gli episodi grossolani non sono presenti e l’intero record stratigrafico è dominato da depositi pelitici di piana alluvionale (fig. 6). 2.1. un nuovo profilo trasversale: il tracciato tav l’esecuzione dei sondaggi penetrometrici ed i carotaggi per la realizzazione della linea ferroviaria ad alta velocità milano-bologna, alcuni chilometri a nord di modena, ha permesso di acquisire un nuovo profilo stratigrafico che si spinge fino a 40-50 m di profondità dal piano campagna, orientato trasversalmente alla direzione dei corsi d’acqua appenninici (fig. 1 e 7) (valloni et al., 2003). dal profilo si può osservare come la sezione stratigrafica sia grosso modo suddivisibile in due parti. nei primi 25-30 m della sezione, i corpi sabbiosi sono rari e discontinui, suggerendo una correlazione con i depositi limosi e sabbiosi sovrastanti le ghiaie dell’unità di vignola, (pleistocene sommitale e dell’olocene del subsintema di ravenna). a conferma di ciò, sono dispo381composizione dei sedimenti sabbiosi ... nibili due datazioni radiometriche di un livello continuo di torbe rinvenuto nella parte basale di questa unità più superficiale. le datazioni sono state eseguite su campioni ubicati esternamente all’area studiata (baio, comunicazione personale) e hanno fornito un’età di 11,8 e 11,2 ka. tali età radiometriche consentono anche di correlare questo orizzonte pelitico con l’unità sommitale distinta nella pianura ad est del f. reno (unità b2: fig. 3 colonna stratigrafica schematica del sottosuolo nel centro urbano di modena secondo i dati di cremaschi & gasperi (1989) e gasperi & pizziolo (in stampa). legenda: 1) peliti prevalenti con orizzonti sabbiosi; 2) corpi ghiaioso-sabbiosi; 3) livelli con resti organici; 4) orizzonte pedogenizzato. schematic stratigraphic column of the modena urban area (data from cremaschi & gasperi 1989 and gasperi & pizziolo, in press). legend: 1) pelites with sand horizons; 2) grave-sand bodies; 3) organis-rich layers; 4) pedogenetic horizons. 382 fig. 4 sezione geologica traversale alla pianura modenese passante a sud del centro urbano che evidenzia la distribuzione in profondità dei corpi ghiaiosi (da gasperi et al., 1989). la linea tratteggiata in grassetto divide la parte superiore, con scarsi corpi ghiaiosi (subsintema di ravenna) da quella inferiore, caratterizzata da un notevole sviluppo di depositi grossolani. la linea tratteggiata inferiore rappresenta il limite dei dati. geological section transversal to the modena plain showing the distribution of the gravel bodies at depth, south of the urban area (from gasperi et al., 1989). the hatched thick line separates the upper gravel-poor portion (ravenna subsyntem) from the lower gravel-rich part. the lower hatched line mark the data limit. fig. 5 sezione geologica attraverso l’area urbana di modena (a nord della via emilia) nella quale è evidenziata (linea tratteggiata) il limite tra la porzione superiore costituita da peliti e corpi sabbiosi discontinui (subsintema di ravenna) e la porzione sottostante ricca in corpi ghiaioso-sabbiosi (unità di vignola). in corrispondenza del centro cittadino è evidenziata l’unità di modena (puntinato) con depositi di epoca post-romana (modificata da fazzini & gasperi, 1996). geological section along the modena urban area (north of via emilia) showing the limit (hatched line) between the upper gravel-poor portion (ravenna subsyntem) and the lower gravel-rich part (vignola unit). below the urban area is present the modena unit (dotted), characterized by post-roman age deposits (modified from fazzini & gasperi, 1996). fig. 6 sezione stratigrafica trasversale della pianura modenese all’altezza di carpi e ravarino. la sezione è ubicata circa 7 km a nord del tracciato della linea tav. sono messi in evidenza i rari e discontinui corpi sabbiosi intercalati a peliti (da: gruppo di studio sulle falde acquifere della pianura padana, 1979). geological section transversal to the modena plain near carpi and ravarino. the section is located about 7 km north of the tav track. notice the rare and discontinuous sand bodies intercalated into the pelites (from gruppo di studio sulle falde acquifere della pianura padana, 1979). s. lugli et al. 383 amorosi et al., 1996). valloni et al. (2003) collegano i livelli torbosi con età di circa 12 ka, alla fase di disattivazione delle conoidi fluviali legato alla trasgressione flandriana. ulteriori dati cronologici potranno provenire dalle indagini su alcuni campioni di materia organica da noi prelevati durante l’esecuzione dei sondaggi. lungo il profilo corrispondente alla linea tav, l’orizzonte sottostante 25-30 m di profondità è più ricco di corpi sabbiosi e può essere correlato con l’unità di vignola (fig. 7). tra le due porzioni dovrebbe essere presente una superficie di discontinuità corrispondente ad una prolungata interruzione della sedimentazione posteriore alla fase di costruzione delle conoidi pedemontane; la sezione studiata ne rappresenta l’area esterna, di transizione alla vera e propria pianura alluvionale. la deposizione delle conoidi si sviluppò, come accennato, durante o subito dopo l’ultima fase glaciale tardo-pleistocenica, od in corrispondenza di una fase particolarmente intensa di sollevamento della catena, come suggerito dalle ricerche in aree adiacenti (amorosi et al., 1996). la possibilità di prelevare campioni di sabbie durante l’esecuzione dei lavori di perforazione per la linea ferroviaria ha fornito un nuovo strumento indipendente di verifica del quadro stratigrafico e del modello interpretativo di riferimento. l’analisi composizionale può permettere infatti di verificare, anche lungo una trasversale più distale e meno definita dal punto di vista litologico se, come ipotizzato per il sottosuolo dell’area urbana, i depositi alluvionali appartenenti all’unità di vignola e quell i sovrastanti di pertinenza del subsintema di ravenna, presentino un’alimentazione dovuta a differenti apparati fluviali. gli orizzonti sabbiosi infatti, diversamente da quelli pelitici che derivano da esondazioni che interessano potenzialmente vasti tratti di pianura, sono legati a forme ed ambienti deposizionali strettamente connessi all’alveo fluviale (barre di canale, barre di meandro, depositi di argine, depositi di rotta) e dunque possono documentare le divagazioni spaziali e temporali di singoli corsi d’acqua. questa possibilità di verifica presuppone che vi sia stata, almeno durante il pleistocene sommitale e l’olocene, una sostanziale stabilità nel segnale composizionale relativo ai vari corsi d’acqua. 3. composizione dei sedimenti sabbiosi nelle perforazioni tav 3.1. metodi le perforazioni effettuate lungo il tratto modenese del tracciato ferroviario ad alta velocità hanno fornito numerosi campioni di sabbie prelevate in profondità fino a 40-50 m dal piano campagna. le perforazioni realizzate per il tracciato tav hanno attraversato prevalentemente sedimenti pelitici con intercalazioni sabbiose di modesta entità, per un intervallo temporale che presumibilmente copre il pleistocene sommitale e l’olocene. per il presente studio sono stati presi in esame 28 campioni di sabbie prelevati da 6 perforazioni nella porzione del tracciato tav che corre tra i fiumi secchia e panaro, a nord dell’abitato di modena, per uno sviluppo complessivo di 5,5 km (fig. 8, 9). fig. 7 sezione stratigrafica lungo il tracciato della linea tav (modificata da valloni et al., 2003). la linea tratteggiata indica il limite fra la porzione superiore (subsintema di ravenna) e la porzione sottostante (unità di vignola), sono indicate le perforazioni dalle quali sono stati prelevati i campioni di sabbie analizzati. geological section along the tav track (modified from valloni et al., 2003). the hatched line shows the limit between the upper ravenna subsyntem and the lower vignola unit. the sampled wells are also shown. fig. 8 ubicazione delle perforazioni studiate lungo il tracciato ferroviario ad alta velocità. location of studied wells along the new high speed train tract (tav). composizione dei sedimenti sabbiosi ... 384 la frazione sabbiosa di tali campioni è stata separata nei diversi intervalli granulometrici mediante setacciatura. la frazione fine (0,250-0,125 mm) è stata impregnata attraverso resina epossidica per la realizzazione di sezioni sottili, colorate per il riconoscimento dei feldspati (houghton, 1980). sulle sezioni è stata condotta l’analisi modale al microscopio ottico mediante conteggio di circa 300 granuli, secondo la metologia gazzi-zuffa (gazzi, 1966; dickinson, 1970; zuffa, 1985), che permette di calcolare, partendo dai dati ottenuti, i vari parametri dei principali diagrammi classificativi proposti in letteratura. lo schema classificativo utilizzato (cibin & di giulio, 1996), mostrato in tab.1, comprende anche componenti intrabacinali e antropici, quali laterizi, bioclasti penecontemporanei e concrezioni carbonatiche diagenetiche, esclusi in fase di elaborazione dei dati in quanto non diagnostici della provenienza dei sedimenti fluviali. l’errore che viene compiuto utilizzando il conteggio al tavolino integratore di 300 granuli corrisponde a 2 σ = 2% per un componente presente al 5% (5% ± 2) al 95% di confidenza. un componente presente al 50% è invece caratterizzato da 2 σ = 5,7 % (50% ± 5,7) al 95% di confidenza (howarth, 1998). per semplicità di lettura tali errori non sono riportati nei diagrammi classificativi presentati. 3.2. risultati i risultati composizionali ottenuti dai conteggi al tavolino integratore sono stati confrontati con i dati ottenuti da lugli et al. (2003) sulle sabbie oloceniche e attuali dei corsi d’acqua che solcano il territorio modenese (secchia, panaro, tiepido, grizzaga e cerca) e sono sintetizzati nella tabella 1 e in fig. 10 e 11. l’analisi dei sedimenti fluviali attuali ha evidenziato campi composizionali distinti per i diversi fiumi, sulla base del contenuto in quarzo, feldspati, litici carbonatici e ofiolitici. in particolare il sistema fluviale secchiagrizzaga-cerca mostra al suo interno una certa affinità e registra la prevalenza della componente silicoclastica su quella carbonatica terrigena. i depositi dei fiumi panaro e tiepido registrano invece prevalenza dei litotipi carbonatici all’interno della frazione terrigena. la maggior parte dei campioni analizzati in questo lavoro provenienti dai sondaggi tav mostra composizioni affini a quelle caratteristiche dei corsi d’acqua cerca e grizzaga, mentre soltanto tre campioni risultano simili a quelli del fiume panaro e nessuno a quelli del fiume secchia (fig. 10 e 11). più in dettaglio, i campioni analizzati possono essere suddivisi in due gruppi principali: quelli al di sopra e quelli al di sotto dei livelli di torba riferibili ad una età di circa 12 ka (sensu valloni et al., 2003) posta a circa 19-20 m dal piano campagna. nei diagrammi ternari q+f-carb-litici la maggior parte dei campioni presenti al di sopra dei livelli di torba mostra composizioni affini a quelle caratteristiche del torrente cerca (fig. 10). la quasi totalità dei campioni con età maggiore di fig. 9 stratigrafie delle perforazioni tav esaminate (non in scala). le frecce indicano i campioni di sabbie analizzati. stratigraphic columns of the studied wells along the tav track (not to scale). arrows point to the analyzed sand samples. s. lugli et al. 385 ta b . 1 , p ag . 1 c om p os iz io ne m od al e d ei c am p io ni a na liz za ti p re le va ti d al le p er fo ra zi on i t a v . m od al c om p os iti on o f s an d s fr om t he s tu d ie d w el ls a lo ng t he t a v t ra ck . s 7 2 -1 4, 5 s 7 2 -1 9, 5 s 7 2 -2 1, 5 s 7 222 p 1 43 23 p 1 43 24 p 1 83 14 ,5 p 1 81 32 ,5 p 1 81 39 p 1 90 30 ,5 p 1 90 31 p 1 90 32 p 2 16 38 p 2 16 -4 1 n c e q q m on oc ris ta lli no 13 ,6 18 ,1 13 ,0 11 ,2 11 ,6 16 ,3 15 ,4 17 ,1 13 ,1 17 ,8 18 ,5 15 ,6 13 ,3 18 ,4 q p ol ic ris ta lli no a t es si tu ra g ro s. 1, 6 2, 8 2, 0 1, 6 1, 3 1, 3 1, 3 0, 3 0, 6 3, 3 2, 6 1, 2 3, 0 1, 6 q p ol ic ris ta lli no a t es si tu ra fi ne 0, 9 1, 3 1, 0 1, 0 0, 3 1, 0 0, 9 1, 5 0, 9 0, 8 2, 3 0, 6 1, 7 0, 3 s el ce 0, 6 0, 3 0, 3 0, 3 0, 6 0, 6 1, 7 1, 4 1, 5 0, 3 q in f. r. p lu to ni co -g ne is si ca 0, 6 1, 3 1, 0 1, 6 1, 3 0, 3 1, 2 0, 6 1, 4 1, 4 0, 6 0, 7 0, 3 q in f. r. m et am or fic a 0, 7 0, 3 0, 3 0, 6 0, 6 0, 9 0, 3 q in f. r. v ul ca ni ca q in f. r. c la st ic a 3, 8 0, 6 1, 3 1, 3 1, 0 2, 3 0, 3 1, 8 0, 9 1, 1 1, 2 1, 8 1, 0 0, 3 f k m on oc ris ta lli no 0, 6 2, 0 3, 6 5, 1 6, 8 3, 1 3, 0 3, 0 3, 3 0, 3 4, 8 0, 7 3, 9 k in f. r. p lu to ni co -g ne is si ca 0, 7 1, 6 1, 0 0, 9 0, 3 0, 9 0, 3 0, 3 k in f. r. m et am or fic a k in f. r. v ul ca ni ca k in f. r. c la st ic a 0, 3 0, 3 p m on oc ris ta lli no 15 ,2 17 ,2 14 ,3 9, 9 13 ,5 11 ,1 9, 1 12 ,5 13 ,7 18 ,9 20 ,2 12 ,9 15 ,0 10 ,7 p in f. r. p lu to ni co -g ne is si ca 1, 3 0, 7 0, 7 0, 6 0, 7 0, 3 2, 1 1, 2 0, 8 2, 6 1, 8 0, 7 1, 3 p in f. r. m et am or fic a 0, 3 0, 3 p in f. r. v ul ca ni ca p in f. r. c la st ic a 1, 6 1, 0 0, 3 0, 3 0, 3 0, 6 0, 9 0, 3 0, 7 l li tic o m et am or fic o 0, 6 0, 3 0, 7 0, 9 0, 6 0, 6 0, 3 li tic o vu lc an ic o 0, 0 li tic o ip oa b is sa le 0, 3 1, 6 2, 3 0, 3 1, 3 0, 3 0, 6 1, 8 0, 6 0, 8 0, 9 0, 6 1, 0 0, 3 s p ili te 0, 9 0, 0 0, 7 1, 0 0, 7 0, 6 0, 6 0, 3 0, 6 0, 3 0, 3 s er p en tin ite 1, 3 2, 2 2, 3 2, 3 0, 6 0, 3 0, 3 4, 3 0, 3 1, 7 1, 7 0, 3 1, 3 li tic o cl as tic o s ha le 9, 5 8, 8 8, 5 6, 9 8, 7 6, 2 6, 6 6, 4 9, 1 8, 4 5, 2 5, 4 6, 3 10 ,4 s ilt iti 7, 3 8, 1 14 ,3 12 ,5 12 ,5 10 ,4 9, 7 10 ,7 10 ,1 6, 4 10 ,4 10 ,2 10 ,0 9, 4 m ic he e c lo rit i m on oc ris ta lli ne 1, 3 2, 2 0, 7 0, 3 0, 3 0, 9 0, 3 0, 3 2, 8 0, 6 0, 3 m ic he e c lo rit i i n f.r . 0, 3 m in er al e p es an te m on oc ris t 0, 3 0, 7 m in er al e p es an te in f. r. o ss id i f er ro 0, 3 0, 3 0, 3 c e c c al ci te s p at ic a 19 ,9 15 ,3 16 ,9 15 ,8 16 ,7 17 ,3 23 ,6 13 ,1 19 ,8 14 ,2 12 ,1 17 ,1 21 ,3 14 ,6 c al ca re s p at ic o 5, 1 4, 4 2, 9 7, 6 4, 5 3, 6 4, 1 3, 0 4, 3 1, 9 3, 8 5, 1 8, 0 5, 8 c al ca re im p ur o 2, 5 1, 3 1, 6 2, 3 1, 3 1, 6 1, 6 2, 4 5, 5 1, 9 1, 4 2, 4 2, 0 2, 9 m ud st on ew ac ke st on e 11 ,1 14 ,4 15 ,0 18 ,8 15 ,8 15 ,3 18 ,6 14 ,6 11 ,6 9, 7 10 ,7 15 ,0 13 ,0 17 ,8 p ac ks to ne -g ra in st on e b io cl as to (t er rig en o) 0, 3 0, 3 0, 9 0, 6 0, 3 0, 6 n c i a ltr i n c i ( la te riz i) c i b io cl as to (p en ec on te m p or an eo ) a ltr i c i ( ca lc in el li) g ra no in d et er m in at o 0, 3 0, 6 0, 9 1, 2 0, 3 to ta le 10 0 10 0 10 0 10 0 10 0 10 0 10 0 10 0 10 0 10 0 10 0 10 0 10 0 10 0 composizione dei sedimenti sabbiosi ... 386 ta b . 1 , p ag . 2 c om p os iz io ne m od al e d ei c am p io ni a na liz za ti p re le va ti d al le p er fo ra zi on i t a v . m od al c om p os iti on o f s an d s fr om t he s tu d ie d w el ls a lo ng t he t a v t ra ck . p 24 -3 2 p 24 -3 5 p 27 -1 4 p 27 -1 6 p 27 -1 8 p 27 -2 5 p 27 -2 6 p 27 -2 7 p 27 -2 9 p 27 -3 1 p 27 -3 3 p 27 -3 5 p 27 -3 7 p 27 -4 1 p 27 -4 9 n c e q q m on oc ris ta lli no 18 ,4 16 ,4 10 ,8 13 ,5 15 ,4 15 ,8 15 ,5 16 ,3 20 ,3 24 ,2 17 ,6 18 ,6 15 ,8 26 ,0 26 ,5 q p ol ic ris ta lli no a t es si tu ra g ro s. 1, 4 3, 2 1, 5 2, 4 1, 3 5, 0 1, 8 3, 3 4, 3 2, 7 5, 8 2, 5 2, 3 2, 4 2, 2 q p ol ic ris ta lli no a t es si tu ra fi ne 1, 9 1, 4 0, 9 1, 2 0, 6 1, 6 3, 3 2, 4 1, 8 1, 5 1, 2 0, 3 0, 6 2, 4 0, 3 s el ce 1, 1 0, 9 0, 6 1, 2 0, 3 1, 5 0, 3 0, 3 0, 3 1, 2 0, 6 1, 2 0, 9 q in f. r. p lu to ni co -g ne is si ca 0, 3 0, 9 1, 5 0, 6 0, 6 1, 6 1, 5 2, 1 0, 9 1, 8 1, 8 0, 3 0, 6 0, 3 1, 5 q in f. r. m et am or fic a 1, 1 0, 6 0, 3 1, 3 0, 3 0, 3 0, 6 0, 6 1, 5 0, 0 0, 3 0, 0 q in f. r. v ul ca ni ca 0, 3 0, 3 0, 3 0, 0 0, 0 q in f. r. c la st ic a 1, 4 1, 7 1, 8 2, 1 1, 0 1, 6 0, 3 0, 9 0, 9 1, 2 1, 8 1, 5 1, 9 0, 9 0, 9 f k m on oc ris ta lli no 6, 5 6, 6 0, 3 1, 9 8, 5 2, 4 6, 2 8, 3 5, 2 2, 4 3, 5 1, 2 2, 8 k in f. r. p lu to ni co -g ne is si ca 1, 1 1, 2 0, 6 0, 9 0, 3 0, 3 0, 6 0, 3 0, 6 k in f. r. m et am or fic a k in f. r. v ul ca ni ca 0, 3 k in f. r. c la st ic a 0, 3 0, 6 0, 0 0, 6 p m on oc ris ta lli no 7, 9 10 ,1 14 ,8 10 ,7 15 ,4 10 ,7 18 ,8 14 ,5 18 ,5 10 ,0 19 ,1 14 ,9 10 ,6 19 ,0 16 ,7 p in f. r. p lu to ni co -g ne is si ca 1, 1 1, 2 1, 5 1, 6 1, 6 2, 4 2, 4 1, 8 2, 1 1, 2 1, 9 2, 3 2, 4 1, 2 p in f. r. m et am or fic a p in f. r. v ul ca ni ca p in f. r. c la st ic a 0, 6 0, 9 0, 9 0, 6 0, 3 0, 9 0, 6 1, 2 0, 6 0, 9 0, 6 0, 6 0, 9 l li tic o m et am or fic o 0, 8 0, 3 0, 3 0, 3 0, 9 0, 6 0, 6 0, 9 0, 3 0, 3 0, 6 0, 6 0, 3 li tic o vu lc an ic o 0, 3 0, 6 li tic o ip oa b is sa le 1, 6 0, 3 0, 3 0, 6 0, 3 0, 9 0, 6 0, 9 1, 5 0, 6 0, 9 0, 3 0, 6 1, 8 0, 3 s p ili te 0, 5 0, 6 0, 3 0, 9 0, 3 0, 9 0, 3 0, 6 0, 9 s er p en tin ite 1, 1 1, 4 0, 3 0, 6 0, 6 1, 3 0, 9 0, 9 1, 2 1, 2 1, 5 1, 9 1, 0 0, 3 0, 3 li tic o cl as tic o s ha le 7, 0 2, 9 8, 0 6, 7 5, 1 8, 5 4, 0 6, 2 4, 3 4, 2 7, 0 7, 7 4, 2 2, 8 6, 2 s ilt iti 10 ,8 11 ,0 11 ,1 9, 8 11 ,9 6, 6 10 ,0 8, 6 6, 8 8, 8 6, 4 7, 1 8, 4 7, 3 7, 1 m ic he e c lo rit i m on oc ris ta lli ne 0, 3 1, 2 0, 6 0, 6 1, 3 0, 9 1, 2 0, 3 0, 3 0, 3 2, 5 m ic he e c lo rit i i n f.r . 0, 3 0, 3 0, 3 0, 3 m in er al e p es an te m on oc ris t 0, 5 0, 3 0, 3 0, 3 0, 3 m in er al e p es an te in f. r. 0, 3 0, 3 o ss id i f er ro 0, 8 0, 3 0, 3 0, 6 0, 6 0, 3 0, 3 0, 3 0, 3 c e c c al ci te s p at ic a 14 ,9 16 ,4 18 ,2 17 ,4 18 ,3 7 13 ,2 13 ,4 13 ,1 10 ,2 12 ,1 15 ,2 14 ,6 17 ,7 11 ,6 13 ,9 c al ca re s p at ic o 5, 7 5, 2 4, 9 5, 2 3, 5 4, 1 5, 5 5, 0 2, 8 3, 3 3, 3 5, 6 4, 2 2, 4 3, 1 c al ca re im p ur o 1, 9 1, 2 4, 3 3, 1 3, 2 3, 2 3, 6 3, 9 2, 5 3, 3 2, 7 1, 9 1, 3 2, 1 1, 2 m ud st on ew ac ke st on e 11 ,4 15 ,3 17 ,5 20 ,8 16 ,1 9, 8 11 ,9 8, 6 7, 7 11 ,2 8, 8 14 ,9 20 ,6 11 ,0 8, 0 p ac ks to ne -g ra in st on e b io cl as to (t er rig en o) 0, 5 0, 6 0, 3 0, 6 0, 6 0, 9 0, 6 0, 3 0, 6 0, 6 0, 9 n c i a ltr i n c i ( la te riz i) c i b io cl as to (p en ec on te m p or an eo ) a ltr i c i ( ca lc in el li) g ra no in d et er m in at o 0, 3 0, 3 0, 3 0, 9 0, 3 0, 3 0, 6 0, 3 0, 9 0, 3 to ta le 10 0 10 0 10 0 10 0 10 0 10 0 10 0 10 0 10 0 10 0 10 0 10 0 10 0 10 0 10 0 s. lugli et al. 12 ka (fig. 11) non ricade all’interno dei campi composizionali individuati per i corsi d’acqua attuali, ma si allinea in posizione intermedia rispetto ai campi composizionali del grizzaga, del secchia e dell’unità di vignola (pleistocene sup.). come si può notare nella tab. 1, tali campioni sono caratterizzati da un contenuto in granuli feldspatici (13,5-30,8 %) maggiore rispetto a quelli dei corsi d’acqua attuali (6,9-21,3 %). 387 fig. 10 composizione dei campioni prelevati nelle perforazioni tav con età minore di 10-12 ka. nel diagramma sono indicati i campi composizionali delle sabbie attuali e recenti (neolitico) dei corsi d’acqua modenesi. composition of samples from tav wells with an age younger than 10-12 kyr. the diagram shows also the compositional f ields of modern and recent (neolithic) sands of the modena plain streams. fig. 11 composizione dei campioni prelevati nelle perforazioni tav con età maggiore di 1012 ka. nel diagramma sono indicati i campi composizionali delle sabbie attuali e recenti (neolitico) dei corsi d’acqua modenesi e dell’unità di vignola (pleistocene sup., presso formigine). composition of samples from tav wells with an age older than 10-12 kyr. the diagram shows also the compositional fields of modern and recent (neolithic) sands of the modena plain streams and of the vignola unit (late pleistocene, close to formigine). composizione dei sedimenti sabbiosi ... 388 3.3. discussione dei dati composizionali i dati composizionali suggeriscono che l’alluvionamento recente della media pianura modenese, di età inferiore a circa 12 ka, sia stato prevalentemente effettuato dai corsi d’acqua minori, mentre i fiumi maggiori, secchia e panaro, probabilmente contribuivano alla sedimentazione attraverso deposizione di sedimenti fini. il rinvenimento di sabbie non attribuibili ai due fiumi maggiori nel sottosuolo in prossimità del loro attuale letto sembra confermare l’ipotesi che i tracciati del secchia e panaro abbiano iniziato a convergere nella zona a nord della città soltanto in epoca piuttosto recente, come evidenziato dalla distribuzione delle tracce dei paleoalvei ancora visibili in superficie (gasperi & pizziolo, in stampa). altro dato significativo riguarda il torrente tiepido le cui sabbie presentano una composizione del tutto caratteristica e che non sono state identificate nel sottosuolo della media pianura. l’ipotesi più probabile è che anche in passato, così come oggi, esso confluisse nel panaro a monte dell’area esaminata. i campioni prelevati al di sotto dei livelli torbosi riferibili ad un’età di circa 12 ka evidenziano una situazione complessa. le sabbie hanno una composizione particolare, spostata verso il vertice quarzo-feldspati, che non ha corrispondenza con le petrofacies individuate per le sabbie oloceniche e attuali dei corsi d’acqua modenesi. in particolare, come evidenziato in precedenza, le sabbie risultano arricchite in feldspati. la spiegazione di tale composizioni non è semplice. queste sabbie appartengono probabilmente ad un ciclo sedimentario più antico rispetto a quello per il quale è stata dimostrata la validità del nostro schema interpretativo, basato sulla composizione dei sedimenti olocenici ed attuali (lugli et al., 2003). le differenze composizionali riscontrate possono essere indotte da variazioni nella natura dei litotipi affioranti nel bacino di alimentazione, e potrebbero essere collegate all’erosione di successioni terrigene a composizione francamente arcosica, come quelle presenti in successioni torbiditiche del cretaceo superiore di unità liguri interne, o ad unità epiliguri ricche in feldspati. l’erosione di porzioni di formazioni geologiche di composizione diversa rispetto a quelle attualmente affioranti potrebbe inoltre essere il risultato di variazioni nello sviluppo ed estensione del reticolo idrografico. la variazione composizionale dei sedimenti trasportati dai corsi d’acqua potrebbe essere imputata a mutamenti climatici legati ai cicli glaciale-interglaciale in grado di indurre variazioni nell’entità e modalità dei fenomeni di alterazione ed erosione del substrato (effetto climatico). altro fattore che può aver contribuito alla differenziazione composizionale riscontrata nei sedimenti deposti intorno a 10-12 ka sono le alterazioni diagenetiche, che potrebbero aver in parte modificato i granuli di sabbia in condizioni di seppellimento. tali effetti però non hanno modificato in misura importante i sedimenti fluviali olocenici (lugli et al., 2003). i fenomeni diagenetici nelle sabbie oloceniche consistono infatti prevalentemente nella formazione di concrezioni carbonatiche, e non possono quindi essere responsabili di arricchimenti in feldspati, minerali ritenuti particolarmente labili in tali condizioni diagenetiche. non ultimo, il riciclo di successioni sedimentarie più antiche potrebbe aver contribuito alla produzione di sedimenti a composizione diversa rispetto a quelli oggi deposti. tali fenomeni di riciclo dovevano comunque coinvolgere sedimenti caratterizzati da un contenuto in feldspati maggiore di quello attuale. le differenze composizionali osservate tra la porzione superiore e quella inferiore della successione studiata indicano cambiamenti drastici nel contesto geografico, ambientale e deposizionale, avvalorando l’ipotesi di una significativa discontinuità stratigrafica tra le due porzioni. 4. conclusioni le perforazioni tav hanno permesso di evidenziare come la sedimentazione fluviale nella media pianura modenese sia drasticamente mutata a partire da circa 10-12 ka. la composizione dei sedimenti sabbiosi più recenti sembra ricalcare quella dei corsi d’acqua minori che attraversano oggi la pianura nel tratto compreso tra i fiumi secchia e panaro. i sedimenti sabbiosi più antichi di circa 10-12 ka presentano invece composizioni diverse, arricchite in feldspati. queste differenze composizionali possono riferirsi a combinazioni di vari fattori quali: a) variazioni nella litologia del substrato per fenomeni tettonici e/o per variazioni nello sviluppo del reticolo idrografico, b) fenomeni di riciclo di sedimenti fluviali antichi. l’arricchimento in feldspati che caratterizza queste sabbie rende improbabili effetti di alterazione per variazioni climatiche e/o modificazioni diagenetiche post-deposizionali. i dati composizionali acquisiti, la distribuzione dei sedimenti sabbiosi lungo la sezione studiata ed il confronto con le stratigrafie oloceniche e tardo-pleistoceniche in settori più prossimali (area urbana di modena e alta pianura) suggeriscono che tra i sedimenti tardo-pleistocenici e quelli olocenici sia presente una significativa discontinuità stratigrafica di importanza regionale. i nuovi dati composizionali in corso di acquisizione e le datazioni assolute attualmente in via di realizzazione permetteranno di ottenere nuove informazioni utili per interpretare l’evoluzione spaziale e temporale dei corpi fluviali nel sottosuolo della pianura modenese. ringraziamenti questo lavoro non sarebbe stato possibile senza la disponibilità delle ditte operanti nei cantieri della tav. un ringraziamento al consorzio cepav uno e in particolare a maria de vita per la gentilezza e la disponibilità dimostrata. un ringraziamento a mariangelo baio e renzo valloni per le preziose informazioni e il diretto aiuto sul terreno. riferimenti bibliografici amorosi a. & farina m. (1994) sequenze deposizionali nei depositi alluvionali quaternari del primo sottosuolo nell'area a est di bologna, tra il t. savena e s. lugli et al. 389 il t. idice 1st. european congress on regional geological cartography and information systems. bologna, june 13-16, 5, pp. 35-54. amorosi a. & farina m. (1995) – large-scale architecture of a thrust-related alluvial complex from subsurface data: the quaternary succession of the po basin in the bologna area (northern italy) giorn. di geol., ser. 3, 57 (1/2), pp. 3-16. amorosi a., farina m., severi p., preti d., caporale l. & di dio g. (1996) genetically related alluvial deposits across active fault zones: an example of alluvial fan-terrace correlation from the upper quaternary of the southern po basin, italy sedim. geol., 102, pp. 275-295. cibin u. & di giulio a. (1996) proposta per l’analisi microscopica della composizione delle areniti nell’ambito della carta geologica d’italia boll. serv. geol. d’italia, cxv, pp. 87-98. cremaschi m. & gasperi g. (1989) l’alluvione alto medioevale di mutina (modena) in rapporto alle variazioni ambientali oloceniche mem. soc. geol. it., 42, pp.179-190. dickinson w.r. (1970) interpreting detrital modes of graywacke and arkose journ. sedim. petrology, 40, pp. 695-707. fazzini p. & gasperi g. (1996) il sottosuolo della città di modena accad. naz. sci. lett. arti di modena miscellanea geologica, 15, pp. 41-54. gasperi g., cremaschi m., mantovani uguzzoni m.p., cardarelli a., cattani m. & labate d. (1989) evoluzione plio-quaternaria del margine appenninico modenese e dell'antistante pianura. note illustrative alla carta geologica mem. soc. geol. it. 39, pp. 375-431. gasperi g. & pizziolo m. (in stampa) note illustrative della carta geologica d’italia a scala 1:50.000. foglio 201 “modena” regione emilia-romagna servizio geologico d’italia. gazzi p. (1966) le arenarie del flysh sopracretaceo dell’appennino modenese; correlazioni con il flysh di monghidoro miner. petrogr. acta, 12, pp. 69-97. houghton h.f. (1980) refined techniques for staining plagioclase and alkali feldspars in thin section journ. sedim. petrology, 50, pp. 629-631. howarth r.j. (1998) improved estimators of uncertainity in proportions, point-counting and pass-fail test results am. journ. of science, 298, pp. 594607. lugli s., marchetti dori s. & fontana d. (2003) composition of fluvial sands as a tool to unravel the recent sedimentation history of the modena plain (northern italy) abstract: 22nd ias meeting of sedimentology, opatj ia (croatia), 17-19 september 2003, abstracts book, p. 11. pellegrini m. & zavatti, a. (1979) le falde acquifere della pianura a sud del fiume po, tra i fiumi enza e panaro genio rurale, 42, 5. regione emilia-romagna & eni-agip (1998) riserve idriche sotterranee della regione emilia-romagna (a cura di di dio g.). s.el.ca. (firenze) pp. 120. valloni r., baio m. & bedulli f. (2003) architettura deposizionale del pleistocene superiore nel sottosuolo della media pianura emiliana riassunti convegno fist geoitalia 2003, bellaria,16-18 settembre 2003, pp.125-127. media print, livorno. zuffa g.g. (1985) optical analyses of arenites: influence of methodology on compositional results in (a cura di g.g. zuffa) “provenance of arenites”. nato asi series, reidl publishing company, 148, pp. 165-189. ms. ricevuto l’11 maggio 2004 testo definitivo ricevuto il 18 agosto 2004 ms. received: may 11, 2004 final text received: august 18, 2004 composizione dei sedimenti sabbiosi ... hara into a verdant landscape dotted with lakes, rivers, and vegetation ranging from wooded steppe to savanna (petit-maire & riser, 1981; petit-maire & riser, 1983). pollen analyses have revealed the presence of tropical and sahelian taxa, indicating increased biodiversity. in addition, speleothem records confirm the persistence of humid conditions during the late pleistocene and early holocene (ritchie et al., 1985; salzmann & waller, 1998; lézine & casanova, 1989; cheddadi et al., 2009; ait brahim et al., 2023; helmens, 2014; lézine et al., 2023; paine et al., 2024). however, as summer insolation gradually declined, the african monsoon retreated southward, leading to progressive aridification and the re -establishment of desert conditions across the sahara (nicole petit-maire et al., 1983; salzmann & waller, 1998). this process of desertification is well documented during the mid-holocene, particularly through lacustrine records such as those from lake yoa in chad, which reveal a continuous and gradual drying trend over the past 6.000 years (kröpelin et al., 2008). an abrupt increase in saharan dust deposition in the atlantic around 5.000 cal bp further supports this shift (demenocal et al., 2000). marine sediment records also confirm this trend, as shown by the studies of lézine et al. (2005), weldeab et al. (2005), and haslett & smart (2006). despite these climatic evidence, research on the evolution of fluvial systems in north africa remains limited. yet, alluvial archives represent valuable indirect indicators of paleohydrological dynamics during the late available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 38 (2), 2025, 85-109 https://doi.org/10.26382/amq.2025.05 1. introduction the glacial periods of the late quaternary, particularly marine isotope stages (mis) 5b and 3, as well as the holocene interglacial, reflect the complex processes underlying earth’s climatic variability (siddall et al., 2006; romero et al., 2011; bereiter et al., 2012). these periods are characterized by alternating wet and dry phases, which continue to be the focus of extensive research aimed at understanding the origins and driving mechanisms of these climatic shifts (foley et al., 2003; castañeda et al., 2009; specht et al., 2024; zaky et al., 2024). during the early holocene, substantial evidence indicates significantly increased moisture levels across the sahara desert in north africa (petit-maire & riser, 1981; petit-maire & riser, 1983; pachur et al., 1987; petit-maire, 1989; pachur & hoelzmann, 1991; depreux et al., 2021; petit-maire, 2021; cheddadi et al., 2021). geomorphological, lacustrine, and paleoecological records consistently show that the region was markedly wetter than today and extensively vegetated throughout the early to mid-holocene. this multi-millennial phase of enhanced humidity is commonly referred to as the “african humid period” or the “green sahara” (streetperrott et al., 1993; kröpelin et al., 2008; lézine et al., 2011; limondin-lozouet et al., 2013; burrough & thomas, 2013; campbell et al., 2017; depreux et al., 2022; lghamour et al., 2024). furthermore, the northward expansion of the african monsoon brought abundant rainfall to areas that are now arid, transforming the sahigh-resolution morpho-sedimentary and paleoenvironmental evolution of wadi akka (drâa basin, morocco) from late pleistocene to holocene fatima saadi 1,2, larbi boudad 1, mailys richard 3,4, jean-françois berger 2 1 geosciences, water, environment laboratory, earth sciences dep., faculty of sciences, mohammed v university in rabat, morocco. 2 cnrs, umr 5600 evs-irg, university of lyon, france. 3 archéosciences bordeaux, umr 6034 cnrs-bordeaux montaigne university, pessac, france. 4 department of early prehistory and quaternary ecology, university of tübingen, tübingen, germany. corresponding author: fatima saadi <fatima_saadi@um5.ac.ma> abstract: the fluvial evolution of southern morocco during the late quaternary, particularly in non-mediterranean basins such as the wadi akka, a tributary of the drâa, remains poorly documented. this study presents the first chronostratigraphic framework for the wadi akka formations, based on a high-resolution reconstruction of fluvial dynamics and paleoenvironmental changes since the end of the last interglacial period. the analysis follows a multiproxy approach, combining geomorphological, sedimentological, and geochemical data, and is supported by 13 radiocarbon and four optically stimulated luminescence (osl) ages. nine main stratigraphic units reveal alternating phases of aggradation, pedosedimentary stability, and incision, associated with climatic fluctuations from marine isotope stage (mis) 5b (~82 ka) to the late holocene. during mis 3 (~40 ka cal bp), a low-energy hydromorphic environment prevailed, marked by fine sedimentation and soil development under relatively humid conditions. the early african humid period (11.400-9.700 cal bp) is characterized by fluvio-lacustrine settings, peat layers, and tufa deposits, indicating stable, wet environments. conversely, arid phases are marked by significant incision and sedimentary hiatuses, particularly between 9.500-8.500 and after 6.000 cal bp. alluviation phases are also dated to around 7.200 and 656-579 cal bp. the presence of tuf deposits and travertine dams indicates peaks in humidity, especially during the beginning of little ice age. finally, comparison with other regional archives has allowed for the reconstruction of upper pleistocene and holocene paleoenvironmental conditions at both regional and supra-regional scales, highlighting the correspondence between phases recorded in the akka plain and broader climatic events in the region. keywords: fluvial geomorphology, multi-proxy analysis, mis 5b and mis 3, holocene, akka plain, drâa valley. pleistocene and holocene. unlike slope or colluvial deposits, which reflect more localized processes, fluvial records integrate environmental changes across entire watersheds, offering a broader and more comprehensive perspective on past hydrological variability (faust et al., 2004; zielhofer & faust, 2008; zielhofer et al., 2008). this transitional period is crucial for understanding the profound landscape transformations and the multiple forcing mechanisms that have driven the ongoing aridification of north africa. however, the current state of research highlights significant gaps, as many regions still lack chronological frameworks or pedo-sedimentary archives documenting paleoenvironmental, climatic, and anthropogenic events during the late quaternary. in southern morocco, the akka wadi is a major right-bank tributary of the drâa river in its lower basin, which spans approximately 66 km² and extends into the northwestern sahara desert. the history of studies on this sector of africa has received little attention from geomorphologists and quaternary scientists. notably, the akka plain has never been investigated in the context of holocene paleoenvironmental reconstructions. this area of south-eastern morocco lacks of absolute chronological data, despite a few earlier contributions (weisrock et al., 1991; wengler et al., 2002; mathieu et al., 2004; weisrock et al., 2006, 2008). as a result, there remains a significant gap in morpho-pedosedimentary and paleoenvironmental documentation of climatic and anthropogenic changes during the recent quaternary (mathieu et al., 2004). in contrast, only a handful of recent studies have focused on marine sequences off cape ghir in southern morocco (baqloul et al., 2021; tadoumant et al., 2022). meanwhile, the mediterranean watersheds of northern morocco, such as the moulouya river and its tributaries, as well as the kert river, have been the focus of extensive geomorphological and paleoenvironmental research. (lefèvre, 1985; el amrani et al., 2008; zielhofer et al., 2010; ibouhouten et al., 2010; bartz et al., 2018; depreux et al, 2021, 2022), resulting in a ro 86 saadi f. et al. fig. 1 geographical location of the study area: a) satellite image of morocco showing the akka sub-basin (outlined in white) within the drâa basin (outlined in black line). (source: terra color imagery, esri, 2009), b) topographical map of the akka watershed highlighting the study area. (source: shuttle radar topography mission (srtm)), c) geological and geomorphological map of the akka plain with the study area indicated by a red rectangle. the legend below corresponds to maps (c) and (d), d) locations of the profiles and stratigraphic sections studied along the eastern and western banks of the wadi. bust and near-continuous holocene chronostratigraphic framework for that region. the main objectives of this study are as follows; a) to carry out a comprehensive geomorphological analysis of alluvial formations across several sectors of the akka basin, b) to refine the chronostratigraphic framework of recent quaternary alluvial deposits through the examination of multiple transects and the application of absolute dating methods, including radiocarbon (¹⁴c) and optically stimulated luminescence (osl), c) to perform detailed physico-chemical and sedimentological analyses on samples collected from selected profiles, with the aim of developing a diachronic model reconstructing the hydrogeomorphological and paleoenvironmental evolution of the region, d) to investigate the climatic and anthropogenic drivers of the observed paleoenvironmental changes in the akka sequence by comparing our results with published paleoclimatic and paleoenvironmental data at the regional scale, encompassing the northwestern sahara and broader north africa. 2. study area the akka wadi is a major right-bank tributary of the drâa river (fig. 1a), situated in the pre-saharan zone of the western anti-atlas in southern morocco. it drains a sub-basin covering approximately 2.190 km² along a course of about 100 km (fig. 1b). due to its geographical position, the tata-akka region experiences a continental saharan hyper-arid climate. annual precipitation is low, averaging around 100 mm (monographie 2015 agence du bassin hydraulique drâa), primarily occurring as intense thunderstorms. prolonged dry spells of 4 to 5 months without rainfall are common. temperatures exhibit considerable daily and seasonal variability, ranging from minima of around 12 °c in winter to highest values reaching 49 °c in summer. 3. materials and methods 3.1. geomorphological and chronostratigraphic context the identification of the studied terraces is based on a geomorphological survey combining the analysis of google earth satellite images and field observations. satellite images allowed the identification of the bestpreserved holocene alluvial terraces, while field campaigns validated these observations by identifying the most intact construction sections, exposed by the recent natural incision of watercourses. four field campaigns were thus conducted in the akka region, southern morocco, in may 2022, april 2023, november 2023, and january 2024. the geomorphological map of the akka area (fig. 1c) illustrates the geological and morphological framework of the study site. the upstream watershed is dominated by rugged mountainous terrain reaching approximately 1100 m in altitude, characterized by steep slopes composed of ancient ordovician rocks, notably the bani 87 high-resolution morpho-sedimentary and paleoenvironmental evolution of wadi akka ... >>>>> fig. 2 a) panoramic photograph of the left bank outcrop of akka wadi; b) stratigraphic section of the left bank showing the location of the three studied stratigraphic profiles (1, 2, and 3), c) panoramic photograph of the right bank outcrop of akka wadi; d) stratigraphic section of the right bank with the location of the studied profiles (4a and 4b), sandstones. downstream, the landscape extends into low alluvial desert plains, rich in pebbles, up to the confluence of the wadi akka with the drâa river (fig. 1b). the oldest terraces, t1 and t2 (fig. 1c), consist of gravel formations attributed to the middle to upper pleistocene, as indicated by the geological map of the western anti-atlas and the drâa plains (akkatafagount-tata) (choubert & ennadifi, 1970). these two terraces were not investigated in the field due to the absence of precise chronological constraints but are included here for contextual purposes. the most recent terrace, t3, where the studied outcrops are located, is composed of fluviolacustrine deposits and more or less bedded floodplain silts, very locally interrupted by gravel layers with a thickness of 5 to 6 meters. these sediments, mainly greenish silts and occasional tufa deposits, are attributed to the holocene (choubert & ennadifi, 1970). below the t3 terrace lies the ant/t3 terrace (fig. 1c,d), which is topographically lower and corresponds to anthrosol deposits linked to the establishment of the akka oasis, a topic that will be addressed in more detail later. two stratigraphic sections were studied on the recent t3 terrace. the first section, (figs. 2a and 2b), located on the left bank of the akka wadi (29° 22'50.66"n/8°15'51.25"w), includes three profiles (profiles 1, 2, and 3) arranged from north to south. the second section, located on the right bank (29° 22'47.40"n/ 8°15'57.39"w), contains a fourth profile (profile 4). these profiles were selected based on the clear continuity of the sedimentary layers, which is essential for accurate stratigraphic interpretation. the lithostratigraphic analysis of the four profiles led to the identification of 19 sedimentary grouped in 9 main units. the identification of sedimentary units is primarily based on lithological descriptions carried out in the field, including outcrop sketches, as well as the analysis of structures, texture, and color of the units. due to local topographic configurations, successive interbedding of alluvial layers, oblique intersections of old palaeochannels, observable truncations, and longitudinal facies variations, it is often necessary to study several complementary sedimentary logs at the same site. this approach makes it possible to best reconstruct the alluvial archive, to capture its initial geometry by developing a local master core that is representative of all the hydrogeomorphological and sedimentary events recorded in the stratigraphic sequence. figure 3 shows a lithostratigraphic correlation of the various units and sub-units from the studied profiles on both sides of the akka wadi. the four profiles reveal eight broadly comparable pedosedimentary phases on 88 fig. 3 correlation of the four dated stratigraphic sequences. (the crossed-out dates indicate a chronostratigraphic inconsistency). saadi f. et al. blocks was extracted and prepared for luminescence analyses. the external part of the blocks, which was exposed to light during sampling, was kept for dose rate measurements. for luminescence dating analyses, each sample was sieved with water and the 100-140 µm fraction was chemically treated following published protocols (e.g. tribolo et al., 2013) including hcl (10%) to dissolve the carbonates and h2o2 (30%) to degrade the organic matter. the quartz and feldspars were extracted using density separation with heavy liquid (heteropoly tungstate of sodium). three separations were conducted, the first one to extract heavy minerals (d=2.72 g/cm3), the second one to separate quartz and feldspars (d=2.62 g/cm3) and the third one to separate plagioclase and potassium feldspars (d=2.58 g/cm3). the quartz fraction was then treated using h2sif6 (31%) over one week and rinsed with hcl (10%) to eliminate the possible remaining feldspars. for dose rate measurements, the external part of each block was dried in an oven and the difference between the wet and the dry weight was used to calculate the water content. note that due to the warm conditions at the time of the sampling, the samples were almost dried and the measured water content may not reflect the average water content during burial time. the ages were thus calculated assuming a water content of 6%. this fraction was then sealed in a container that was analysed using a laboratory gamma-ray spectrometer equipped with a high-resolution, broad energy ge (bege) detector to determine the u, th, and k content in each sample and derive the beta dose rate. the gamma dose rate was measured in situ using a portable gamma-ray spectrometer connected to a labr probe (inspector 1000, canberra) at the same location as the samples. the data were treated using the “threshold” technique (mercier & falguères, 2007). the cosmic dose rate was calculated taking into account the current depth of the samples following the equation in prescott & hutton (1988). b luminescence measurements multi-grain (mg) analyses were first conducted on the quartz of the four samples (1 mm ø aliquots) using the protocol given in tab. s1 with a tl/osl lexsyg smart reader (richter et al., 2015) and a lexsyg research reader (richter et al., 2013). the osl signal was integrated using the first 1.5 seconds and the background subtracted using the last 20 seconds, and the signal was detected with a combination of uv filters (schott bg-3, 3 mm in conjunction with a delta bp365/50 ex). dose recovery tests (drt) were conducted on mg quartz aliquots in order to assess the reliability of the protocol. the disks were bleached two minutes in a solar simulator (hönle 500) and a given dose of 266 gy (akka2-osl1), 202 gy (akka2-osl2), and 91 gy (akka2-osl3) was applied before applying the single aliquot regeneration (sar) protocol in tab. s1. the preheat temperature was fixed at 240°c (akka2-osl1, 2 and 3) and 260°c (akka2-osl1 and 3), and three aliquots were measured for each temperature. the drt (recovered/given) values are, for akka2osl 1, 0.76 ± 15% (240°c) and 0.75 ± 3% (260°c); for akka2-osl 2, 0.95 ± 3% (240°c); for akka2-osl3, 0.94 ± 5% (240°c) and 0.95 ± 10% (260°c). however, considering that the osl signal of akka2-osl1 was close to saturation and that the drt values were under both banks, along with significant morphological changes in the alluvial plain, related to successive incision and refill events. while the two stratigraphic sections are easily accessible for sampling, the scarcity or absence of carbonized remains, especially throughout the coarse basal unit (u1) and the subsequent unit (u2), led us to complement radiocarbon dating with the luminescence dating method, as a complementary technique for the parts where radiocarbon dating material is not available. a detailed description each of these main units is provided in section 4.2. 3.2. sedimentological and pedological analysis sediment samples of approximately 200 g were systematically collected at regular intervals of 4 to 6 cm by recovering material in bulk (using a trowel or pick from the walls of the natural section, thereby destroying the sedimentary structure), based on the lithostratigraphic variations observed in the field. a total of 259 samples were collected from the four sequences. according to the chronostratigraphic order of the master core created. these samples underwent a multiproxy analysis in the laboratory, following a systematic stratified approach, including geochemistry, sedimentology, and chronology. 3.3. chronology 3.3.1. radiocarbon dating the chronology of the studied sequences is based on 13 ams radiocarbon ages obtained from charcoal and organic matter (mineralized peat). due to the scarcity of carbonaceous material, more than 45 samples sieved through a 200-micron mesh (>50), followed by binocular examination at magnifications up to 50x in both natural and incident light to better identify carbonized micro-debris. despite using ams, many carbonized micro-fragments had to be combined to reach the required 1 to 2 mg for dating. we sometimes had to group 2 samples 6 cm apart, but always included in the same stratigraphic sub-unit. this methodological approach ensures that all collected material comes from the same stratigraphic unit. the obtained ages were then assessed for chronostratigraphic consistency, and any date showing inconsistency was systematically excluded in order to ensure the robustness of the proposed chronological framework. the ams analyses were performed at the poznań laboratories (poland). dates were calibrated using intcal20 (reimer et al., 2020) with calib 8 software. radiocarbon dating results are presented in table 1. 3.3.2. optically stimulated luminescence (osl) and post-infrared stimulated luminescence (pirir) dating four blocks were collected from the two studied sections for luminescence dating of sediments. on the left bank, sample akka2-osl1 (profile 4) was taken at a depth of 225 cm, while akka2-osl2 (profile 4) comes from a level at 380 cm. on the right bank, akka2-osl3 (profile 1) was collected at a depth of 250 cm, and akka2-osl4 (profile 2) at 280 cm. a sample preparation the samples were prepared at the archéosciences bordeaux laboratory (bordeaux montaigne university, france), under subdued red light and controlled conditions in order to prevent light exposure. the core of the 89 high-resolution morpho-sedimentary and paleoenvironmental evolution of wadi akka ... the commonly accepted range for mg aliquots of 1 ± 10%, the post-infrared infrared stimulated luminescence protocol at 290°c (pirir290, thiel et al., 2011) was applied on k-feldspars (supplementary tab. s2) using a tl/osl lexsyg smart reader. the irsl signal was detected with a combination of optical filters (schott bg 39-3 mm; ahf brightline hc 414/46-3.5 mm). for the other samples, some of the quartz drcs were saturated or close to saturation (osl 2 and 3) and high overdispersion (od) values were obtained (21%, 34% and 55% for akka2-osl2, 3 and 4 respectively), probably due to differential bleaching (see details in the results section). single grain (sg) osl analyses were thus performed using the protocol displayed in tab. s3 on a risø osl/ tl reader. a green laser was used to measure 1000 grains and the signal was detected using hoya u340 filters. drt tests were conducted on sg disks for akka2-osl 2 (given dose = 147 gy) and 3 (given dose = 69 gy) using the protocol in tab. s3. the recovered/ given values are 0.99 ± 15% (akka2-osl2) and 1.18 ± 20% (akka2-osl3). these ratios are included within 1 ± 20%, due to the intrinsic variations of the samples at the single grain scale. the equivalent doses obtained using both single and multi-grain measurements were selected using the following criteria: a recycling ratio limit of 10%; a recuperation <5% of the natural signal; a maximum test dose error of 10%; and a test dose signal >3 sigma above background. the mg pirir290 signal was integrated using the first 5 seconds and the background subtracted using the last 50 seconds. the sg osl signal was integrated using the first 0.07 seconds and the background subtracted using the last 0.25 seconds. the drc were obtained using an exponential + linear function for the pirir290 measurements and an exponential function for the osl measurements. 3.3.3. sedimentological and geochemical analyses the sedimentological and geochemical analyses presented in this study were conducted on the omeaa platform of umr 5600 evs (environment, city, society) at the université lumière lyon. a laser granulometry grain size analysis was carried out to measure the size of sediment particles and to assess the energy required for their transport. the method is based on measuring laser beam diffraction and the light intensity scattered by particles smaller than 2 mm. measurements were performed using a fritsch analysette 22 laser granulometer. prior to laser granulometry, the samples were chemically pretreated: several treatments with h₂o₂ to remove organic matter, and with hcl to dissolve carbonates, followed by deflocculation with kcl. after rinsing and centrifugation, the samples were dispersed in a sodium hexametaphosphate solution. this method enables the evaluation of flow energy by reconstructing transport hydrodynamics and provides a precise characterization of clay (0.4-2 μm), silt (2-63 μm), and sand (63 μm-2 mm) fractions, as well as variations in hydrological regimes over time. data processing was performed using the gradistat software (version 8), developed in excel by simon j. blott and kenneth pye (blott & pye, 2001). the d50 and d90 values were used to assess flow energy: d50 represents the median flow value, while d90 indicates the maximum flow energy (passega, 1964; bravard, 1983). although d99 would more accurately represent the maximum competence of the current responsible for particle transport (salvador, 2016), the data curves did not allow reliable determination of d99 values, so d90 was preferred instead. b loss on ignition (loi) the loss on ignition (loi) method was used to determine the organic matter (om) and carbonate (caco₃) content of 259 samples. samples were first dried at 106°c for 24 hours. organic matter content was then measured by calcining the dried, ground samples at 550°c for 4 hours using a nabertherm muffle furnace,while carbonate content was determined by firing the samples at 950°c for 2 hours (heiri et al., 2001). c volume magnetic susceptibility (ms) magnetic susceptibility provides insights into the composition and origin of sediments, as well as the postdepositional processes they may have undergone, particularly pedogenesis. this parameter is highly dependent on the chemical and mineralogical composition of the sediments, notably the presence of minerals sensitive to magnetic fields especially iron-bearing phases such as ferrimagnetic minerals (iron oxides, hydroxides, and oxyhydroxides) (dearing, 1999). at a local scale, magnetic susceptibility can also be influenced by various environmental and diagenetic processes, including redox conditions associated with fluctuations in the water table, pedogenic processes involving the alteration, mobilization, and concentration of iron compounds by microbial and bacterial activity, bioturbation, physico-chemical weathering (e.g., hydrolysis), secondary processes following erosion and transport, and even the impact of fire on soil surfaces (mullins, 1977). measurements were conducted on oven-dried and finely ground samples to minimize grain-size effects. samples were placed in plastic cups and analyzed using a bartington ms2e dual-frequency sensor operating at 4.65 khz, with a sensitivity range of 0.1 and a measurement period of 15 seconds. each sample was measured in triplicate, and the mean value was recorded following the protocol established by dearing (1999). results are expressed in si units (10⁻⁸ m³/kg). d geochemical analysis and principal component analysis (pca) x-ray fluorescence can be used to approximate the geochemical composition of sediment through the detection of a number of major and minor elements. to analyze the geochemical content of the three alluvial sequences studied, we used aportable nikon xrf spectrometer. which can measure the quantities of forty major and minor elements. data quality in terms of data precision was analyzed by performing triplicate measurements. samples, previously dried and ground, were placed in cups covered with a film to minimize interference from factors such as grain size, porosity, and moisture content (profe et al., 2016). the geochemical data were analyzed by establishing correlation curves between stratigraphic logs and measured elemental concentrations to identify those showing significant variations. only the elements mn, al, fe, k, rb, ti, si, zr, sr, s, cr, mg, and ca were selected for their consistent detection above limits and meaningful variability. several geochemical ratios were used to evaluate flow energy and redox conditions. the zr/rb 90 saadi f. et al. upstream of the site a common process in fluvial contexts. 4.1.2. osl and pirir290 dating the equivalent doses for the pirir290 multi-grain analyses of akka2-osl1 were computed using the central age model (cam, galbraith et al., 1999), giving an od value of 9 ± 3%, tab. 2. for the other three samples, the single grain measurements allowed the minimum age model (mam) in order to give more weight to the well-bleached grains and discard saturated grains. the od value obtained on the sg measurement of akka2-osl2 is similar to the one obtained on mg aliquots, of 21%. however, the od values are higher for akka2-osl3 and 4, of 52% and 61% respectively (tab. 2). the mam allowed taking into account the youngest grains, i.e., providing a minimum age estimate for the layer. ages are displayed in tab. 2 and range from 82. 9 ± 5.5 ka (akka2-osl1) to 8.5 ± 1.4 ka (osl3). note that the yield of accepted quartz grains is low, under 3%. the statistics regarding the single grain selection criteria are available in supplementary material table. s4. the dose rate data are presented in tab. 3. 4.2. landforms, textures and compositions: multiproxy analyses of the alluvial sequences of akka a detailed analysis of the four akka plain profiles based on granulometric, structural, colorimetric, and pedological criteria (including bioturbation intensity, root traces, types and densities of secondary carbonates, and redox features) identified nine major lithopedostratigraphic units, further divided into 19 sub-units. these units reflect the local hydrogeomorphological history, encompassing erosion, aggradation, and minor bed mobility. the lithostratigraphic and chronological results are detailed in section 4.2.1, and the sedimentological and physico-chemical analyses in section 4.2.2. ‘’multi-proxy analyses and types of pedosedimentary environments’’. ratio serves as an indicator of flooding and coarser (sandy) alluvial deposits in a fluvial context (rothwell & croudace, 2015; jones et al., 2012; wang et al., 2011). the fe/mn ratio help in assessing the redox conditions of the alluvial plain (rothwell & croudace, 2015), while the ca/mg ratio indicates biochemical calcite precipitation related to low environmental hydrodynamics (lauterbach et al., 2011). the si/al ratio is used to identify the origin of windblown or sediment dust (klasen et al., 2015; zech et al., 2008; profe et al., 2016) and is correlated with other proxies influenced by grain size (liang et al., 2013). lastly, the rb/sr ratio serves as an indicator of soil weathering and/or erosion of developed soils (jones et al., 2012; rothwell & croudace, 2015; profe et al., 2016). to synthesize geochemical data signal, a principal component analysis (pca) was conducted. only the eleven most relevant elements rb, fe, ti, k, al, mg, si, zr, s, mn, and ca were included in the pca, based on their environmental interpretability and local stratigraphic relevance. the analysis was performed in r using the factominer, package. no standardization was applied, as all variables were expressed in comparable intensity units derived from the xrf measurements. the pca was based on a correlation matrix (default in factominer), and no missing values were present in the selected dataset. 4. results and interpretations 4.1. chronological results 4.1.1. radiocarbon dating radiocarbon dating provided a total of 13 ages on organic material (charcoal and organic matter). of these, six dates were excluded because they were inconsistent with the chronostratigraphic framework established in the field. these discrepancies appear to be mainly due to contamination by older material, likely reintroduced as a result of repeated phases of erosion and alluviation 91 tab. 1 chronological data of samples from the wadi akka: conventional radiocarbon ages and calibrated ages. high-resolution morpho-sedimentary and paleoenvironmental evolution of wadi akka ... bp (11.227-11.736 cal bp). unit 4 (u4): this formation appears at the base of profile 2 (fig. 5a). it begins with the deposition of a massive clayey silt layer with a pale brown hue (10yr 6/3, pale brown), measuring 50-70 cm in thickness. this basal unit is dated by radiocarbon ¹⁴c to approximately 10.520 cal bp (10.097-10.690 cal bp). overlying this layer is a thicker deposit of brownish clayey silts (u4b) (10yr 5/6, yellowish brown), characterized by intercalated centimeter-scale layers of blackish, highly mineralized peat. the peat is notably flaky and composed of strongly humified plant debris, arranged in indistinct micro-beds (fig. 5c). also present are cylindrical travertine tubes (4-5 cm long, <1.5 cm in diameter) with calcified walls (fig. 5c), melanopsis sp. shells, and a thin yellowish-orange oxidized lens. morphologically, this unit represents the sedimentary infill of a broad alluvial channel approximately 150 meters wide exposed at the base of profile 2 and extending beneath the modern alluvial plain (fig. 2a/b/3). the upper part of the unit has been dated to around 9.591 cal bp (9.025-10.187 cal bp). unit 5 (u5) is identified in both the left and right bank deposits of the akka wadi (fig. 3) and comprises four sub-units. sub-unit u5a is a thin, 10 cm layer of heterometric gravels gs1 (gravel sheet) (fig. 6a), located above u4b. it is discontinuously preserved along the 4.2.1. litho-chronostratigraphy unit 1 (u1): the basal formation (u1a) is found at the base of both outcrops on the left and right banks (fig. 3). it consists of a conglomerate deposit made up of heterometric gravels (2-10 cm) set in a greyish sandy matrix (10yr 7/2, light gray), exhibiting a compact texture. the thickness ranges from 40 cm on the left bank to 70 cm on the right bank (fig. 3). no samples were collected from this unit. above this, unit 1b (u1b) (fig. 4a) consists of alternating infill deposits within narrow or flared gravelly channels, which are shallow, along with lenses of heterometric gravels (figs. 2c and 2d). this sedimentary structure is particularly well-exposed on the right bank, where it displays a braided pattern, indicating high lateral channel migration and significant instability of the floodplain, with a thickness of nearly 2 meters (fig. 2d). overlying this is unit 1c (u1c), a silty clay deposit (10yr 7/3, very pale brown) with a massive structure containing some secondary carbonate nodules. an osl date obtained from this formation suggests an age of approximately 82.900 ± 5.500 years. unit 2 (u2): this unit, observed only on the right bank of the wadi in profile 4 (fig. 3), consists of a silt deposit approximately 1.50 m thick, (fig.4a) with a greenish-gray color (10yr 7/2, light gray). the deposit exhibits a polyhedral structure and contains some shell fragments. osl dating places this unit at approximately 40.5 ± 2.4 ka (tab. 2). unit 3 (u3): this unit is clearly distinguishable in the outcrop by its greenish to light gray color (10yr 7/2, light gray), observed on the left bank of the akka wadi (figs. 2a, 2b, and 3). it appears at the base of profiles 1 and 3 (fig. 4b) and is characterized by a massive silty facies, 50 to 70 cm thick, containing a few centimeter-sized lenses of heterometric gravels. above this lies a massive deposit of silt to fine silty sand (u3b), associated with the presence of melanopsis (probably of aff. cariosa type, according to linnaeus (1789)). this unit (u3), which outcrops discontinuously on the left bank of the akka wadi (figs. 2a, 2b), is preserved over a limited distance of approximately 250 meters to the south. this formation is dated by radiocarbon ¹⁴c to around around 11.428 cal 92 tab. 2 multi-grain (mg) pirir290 ages obtained from k-feldspar of sample akka2-osl1 and single-grain (sg) osl ages obtained from quartz of samples akka2-osl2, 3, and 4 (1σ uncertainties). for mg analyses, de values were measured on 1 mm diameter aliquots. for sg analyses, quartz grains were mounted on standard 150 μm hole disks, reporting accepted (n) and measured (n) grains with overdispersion (od). alpha and beta dose rates were calculated from radioactive elements (u, th, k) measured by gamma spectrometry (tab. 3), using conversion factors from guérin et al. (2011) and alpha attenuation factors (0.14 for u, 0.17 for th) from brennan et al. (1991). gamma dose rates were measured in situ (tab. 3), and cosmic dose rates were estimated from burial depth (prescott & hutton, 1988). feldspar ages were calculated using the central age model (cam, galbraith et al., 1999) with beta absorption factors (0.098 for u, 0.139 for th, and 0.039 for k) as per guérin et al. (2012) and an α-value of 0.08 ± 25%. the internal dose rate for the k-feldspars was calculated using a k-content assumed of 12 ± 1%. quartz ages used the minimum age model (mam) with beta absorption factors (0.100 for u, 0.142 for th, and 0.041 for k) following guérin et al. (2012) and an s-a value of 4.5 ± 20% tab. 3 u, th and k contents of sediment samples analysed with a laboratory gamma-ray spectrometer equipped with a high-resolution, broad energy ge (bege) detector and in-situ gamma dose rate measured using a portable gamma-ray spectrometer. saadi f. et al. shell debris of melanopsis sp. numerous root traces are also visible, pointing to the development of local hydrohygrophilous vegetation. overlying this, sub-unit u5c is a 20 to 60 cm thick layer of homogeneous fine sand of similar coloration (10yr 6/4), marking a transition in sedimentation dynamics and a clear increase in hydrodynamic energy. this intensification culminates in subunit u5d, a deposit of heterometric gravels (gs2) ranging from 10 to 20 cm in thickness, which is consistently visible across the outcrop (figs. 5a, 6a). this gravel right bank outcrop and marks a lithostratigraphic discontinuity, as it erodes the upper part of the underlying fluvio -palustrine deposits (u4b). this erosional contact indicates a significant shift in sedimentary dynamics, prefiguring the processes that dominate the subsequent subunits. sub-unit u5b is composed of massive clayey silts with a light beige color (10yr 6/4 light yellowish brown), measuring between 40 cm thick on the right bank and up to 1 m on the left bank. this facies includes small tufa lenses forming calcified filaments, as well as 93 fig. 4 field photographs of profiles 3 and 4: a) sedimentary units of profile 4 on the right bank, showing sample locations and osl and radiocarbon (¹⁴c) dates, b) profile 3 on the left bank, which forms the base of profile 2, c) gravelly unit u1a at the base of profile 4. fig. 5 field photographs of profile 2 on the left bank: a) overview of the sedimentary units composing profile 2, with sample locations and chronological sequence, b) detailed view of units u8, u9a, and u9b, c) close-up of unit u3b, highlighting travertine tubes, dark peat layers, and melanopsis shell fragments. high-resolution morpho-sedimentary and paleoenvironmental evolution of wadi akka ... prises a tuffaceous sand layer with a yellowish-brown color (10yr 6/4) and a thickness of 70 cm. this deposit features large, heavily cemented travertine tubes (fig. 6b), associated with shell fragments. 4.2.2. multi-proxy analyses and discussion of sedimentary environment types the cross-analysis of sedimentological and physico-chemical data (fig. 7) allows for the reconstruction of past environmental dynamics of the akka plain. based on the results obtained, three main types of pedosedimentary environments (tpe) have been identified. each of these environments is characterized by specific features reflecting depositional conditions (grain size, hydrodynamic energy), the degree of pedogenetic alteration, carbonate precipitation dynamics, organic matter accumulation, redox conditions, and sediment provenance. these elements are summarized in table 5. these parameters were assessed using a series of environmental proxies: grain size indices (d50 and d90) indicate depositional energy; magnetic susceptibility (ms) and the rb/sr ratio inform on the intensity of pedogenetic processes, sometimes associated with high concentrations of organic matter; carbonate content (caco₃) and the ca/mg ratio reflect carbonate precipitation conditions, organic matter (om) content indicates biological productivity or the preservation of authigenic vegetation, the fe/mn ratio is used as a marker of redox conditions, finally, the si/al ratio serves as an indicator of detrital input and can also be interpreted as a proxy for aridity. tpe 1: low-energy fluvio-palustrine environment this type of environment includes units u1b, u2, u3a, and u4b (fig. 7). it is characterized by a high proportion of fine particles (silt and clay), representing between 70% and 90% of the total grain size, with a clear dominance of silt. d50 and d90 values below 30 μm indicate very calm depositional conditions, typical of stable, shallow, or even semi-permanent settings such as wetlands or marshes. magnetic susceptibility is low (5 to 10 × 10⁻⁸ m³·kg⁻¹), consistent with a low concenlayer reflects a major increase in flow energy, likely associated with a significant incision phase of the wadi between profiles 4 and 3, as illustrated in figure 3. unit 6 (u6) is deposited above the gravelly phase (gs2) (fig. 3). it appears in profiles 1 and 2 (figs. 5a and 6a) and is characterized by a facies similar to unit u5b, consisting of massive, tuffaceous clayey silts with a light brown color (10yr 6/4 pale brown). its thickness ranges from 20 to 30 cm and contains a few melanopsis shells. this formation is dated between 8.500 (u5d) and 7.204 cal bp (u7a). unit 7 (u7) starts with a massive deposit of silt (u7a), light yellowish-brown in color (10yr 6/4), clearly visible in profiles 1 and 2, with a thickness ranging from 20 to 50 cm. this layer contains a few roots, especially on the right bank in profile 2 (fig. 5a). above it lies a thick layer of silty sand (u7b), varying from 30 cm to 1 m thick in profile 2. this alluvial plain aggradation features a sometimes well-developed and cemented tufa layer, associated with a few melanopsis shells. the formation is dated to 7.204 cal bp (6.992-7.420 cal bp). unit 8 (u8) corresponds to a channel deposit composed of massive silts that overlie unit u7b (profile 2) (fig. 2b), with a thickness of about 50 cm. it extends over 85 meters, exclusively along the left bank in profile 1 (fig. 2c/d). the unit is also marked by the presence of a few root traces. unit 9 (u9) is subdivided into three sub-units, observed in the upper parts of both outcrops on the left and right banks (fig. 3), south of profile 4. the first sub-unit, u9a, consists of a loose-textured silty sand deposit with a yellowish-brown color (10yr 5/4) and a thickness of 60 cm (fig. 5b). the next sub-unit, u9b, is a fine sand layer about 70 cm thick, perforated by numerous root traces. it is overlain by a thin 10 cm layer of heterometric gravels (gs3), found only in profile 1 (fig. 3). this formation is dated to 656 cal bp (506-904 cal bp). the final sub-unit, u9c, is observed only in profile 1. it com 94 fig. 6 field photos of profile 1: a) view of the sedimentary units forming profile 1 on the left bank to the north; b) zoom on the tuffaceous alluvium deposit (u9c) with large travertine tubes; c) stromatolithic travertine dam observed to the north of profile 1, deposited at the same level as unit u9c. saadi f. et al. 95 tab. 4 synthetic description of the lithostratigraphic facies and the deposits related to the sedimentary environments identified in the akka sequences. high-resolution morpho-sedimentary and paleoenvironmental evolution of wadi akka ... 96 fig. 7 correlation diagramms of the principal granulometric, magnetic, and geochemical properties from the four studied profiles, integrated to propose a reference cross-section of the akka alluvial sequence. colored bands highlight the distinctive characteristics of each sedimentary unit. geochemical ratios are expressed relative to the average values of each ratio. black arrows atop the curves indicate sedimentary discontinuities within the alluvial record. saadi f. et al. ic susceptibility (ms) ranges from 5 to 15 × 10⁻⁸ m³·kg⁻¹, indicating a moderate presence of magnetic minerals. the rb/sr ratio is variable. carbonate contents (caco₃) are moderate to high (50-70%), with high ca/mg ratios, suggesting carbonate precipitation partially linked to biogenic processes or calcium-rich groundwater inputs. organic matter (om) is moderately abundant, generally between 10% and 30%. redox conditions are variable, with occasional fe/mn peaks, indicating a frequently water-saturated environment with possible fluctuations. the si/al ratio is generally low, indicating limited detrital input. however, some units (notably u5b, u6a, u7a, and u8) show peaks in the si/al ratio, indicating changes in sediment sources after 9.700 cal bp, reflecting an increase in fluvial detital or aeolian influence. altogether, these indicators reflect a calm and humid floodplain environment with fine sediment deposits, moderate to advanced pedogenesis, and carbonate precipitation. this type of setting corresponds to sub-humid to humid climatic conditions, with shallow groundwater tables and diffuse runoff and floods events. it is characteristic of low-energy floodplains, where water is present temporarily or semi-permanently, favoring the deposition of fine and relatively stable sediments. these environments are often associated with channel margins, overflow areas, or wetlands fed by groundwater or diffuse surface flow. tpe 3: dynamic high-energy alluvial environment this environment includes units u1a, u5a, u5c, u5d, u7, u9a, and u9b (fig. 7). the grain size is tration of magnetic allogenic minerals, often linked to organic or carbonate-rich environments. the rb/sr ratio is generally high, indicating significant pedogenetic alteration, possibly due to leaching processes or in-situ soil formation. carbonate contents (caco₃) are high (5065%), as are ca/mg ratios, suggesting carbonate precipitation under calm conditions, favored by bicarbonaterich groundwater inputs. these deposits may be associated with the formation of carbonate tufas, particularly in the presence of dense vegetation and good water retention. organic matter is abundant (20-50%), reflecting either local high biological productivity or/and good preservation under hydromorphic conditions. the fe/mn ratio shows medium to high values, indicating alternations between oxidizing and reducing conditions, common in periodically saturated environments. lastly, the si/al ratio is generally low, suggesting limited detrital input and supporting the hypothesis of a closed environment with minimal allochthonous influence. overall, these features indicate a low-energy fluviopalustrine environment, with high biological production, carbonate precipitation, organic soil development, and frequent hydromorphic conditions typically associated with wetter climatic phases or/and high groundwater levels. tpe 2: low-energy (carbonate-rich) floodplain this environment includes units u3b, u4a, u6, and u9c (fig. 7). the grain size distribution is dominated by silty fractions (60-80%), with d50 values below 50 μm, indicating low to moderate depositional energy. magnet 97 tab. 5 comparative summary of pedosedimentary environment types (tpe). high-resolution morpho-sedimentary and paleoenvironmental evolution of wadi akka ... correlation with units u1b, u2, and u4b. iron, a terrigenous element frequently used as a redox indicator (rothwell & croudace, 2015), reflects variations in the oxidation conditions of the environment but also is involved in pedogenesis processes, while rubidium, generally associated with fine clay deposits, indicates detrital input in a low-energy context, potentially linked to pedogenetic or soil erosion processes. in the lower part, zirconium (zr) and silica (si) are enriched in the samples from units u9a, u9b, and u5c. these elements, contained in resistant minerals to physical and mechanical processes such as zircon, reflect high-energy deposits and suggest a predominantly aeolian and/or torrential river inputs. overall, this analysis allows for the distinction of three main sedimentary poles: carbonate deposits with redox conditions represented by units u1b, u2, and u4b; alluvial detrital inputs mainly grouping units u7b and u8; and finally, coarse deposits with a dominant aeolian origin characterizing units u9a, u9b, and u5c. 5. synthesis and discussion in this section, we discuss the morphosedimentary and paleoenvironmental evolution of the akka plain. our analysis draws on the geochemical composition and sedimentary dynamics of the formations, alongside the concurrent development of the alluvial plain’s geomorphological setting and the chronological framework of the deposits. by correlating these proxies, we reconstruct the local geomorphological and paleoenvironmental history of the plain from the late pleistocene (mis 5b) to the present (fig. 9). these results are compared with similar reconstructions from alluvial archives across north africa, as well as with recently published paleoenvironmental and paleoclimatic data at local, regional, and supraregional scales throughout the eastern sahara and north africa (fig. 10). our approach involves correlating evolutionary histories reconstructed in other regions to validate and strengthen our local findings, thereby situating them within the broader context of paleoenvironmental dynamics. 5.1. mis 5b (ca. 82.9 ± 5.5 ka): fluvial aggradation and hydroclimatic instabilities during phase 1, dated to approximately 82.9 ± 5.5 ka, the akka plain records a marked phase of aggradation, characterized by sediment accumulation reaching up to 4.5 meters in thickness. the sedimentary sequence displays a fining-upward trend: coarse sediments at the base gradually give way to finer materials, interspersed with gravelly layers in the upper section. these deposits are associated with narrow and shallow channels, where massive, heterometric gravel unit are observed typical of a braided river system. this type of fluvial dynamic is generally seen in deep valleys subjected to highly variable hydrological regimes or in response to exceptional rainfall events (lghamour et al., 2024) paine et al., (2024). the silty matrix binding the gravel elements suggests deposition during waning flood stages. it also indicates the probable presence of permanent ponds during low-flow periods. these features reflect strong alluvial activity driven by unstable hydroclimatic conditions, likely linked to the end of the last interglacial period (marine isotope stage 5), a phase still poorly documented in the fluvial archives of southern morocco and coarse, dominated by sand (70-80%) and sometimes gravel, indicating high hydrodynamic energy and stronger connectivity with upstream areas. grain size indices are high (d50 > 100 μm, d90 > 220 μm), and the zr/rb ratio is also significant, confirming rapid and energetic fluvial transport. magnetic susceptibility varies (10 to 50 × 10⁻⁸ m³·kg⁻¹), with high values in certain units (e.g., u5a, u9b), indicating a stronger contribution of detrital magnetic minerals. the rb/sr ratio is low, reflecting limited mineral alteration due to rapid deposition and minimal pedogenetic development. carbonate contents (caco₃) are moderate (40-50%), with low ca/mg ratios, indicating a context where carbonate precipitation is not favored due to the high-energy depositional dynamics. organic matter content is very low (2-15%), reflecting a very detrital environment unfavorable for its accumulation and frequently subject to remobilization. the fe/mn ratio is highly variable, suggesting possible alternations between oxidizing and reducing phases. finally, the si/al ratio is high, confirming a substantial input of coarse detrital material of aeolian or torrential origin. overall, this type of environment reflects an active, high-energy alluvial setting dominated by coarse inputs, minimal soil development, poor organic matter preservation, and indicative of episodic flood phases, aeolian redeposition of alluvial deposits associated to drier climatic conditions. 4.3. principal component analysis (pca) in order to gain a better understanding and simplify the analysis of the geochemical dataset obtained from x -ray fluorescence (xrf), we conducted a principal component analysis (pca). for a clearer representation of the results, only the most representative units from each profile were selected, thus forming the core geochemical dataset (fig. 11 in supplementary material) figure 8 shows the pca biplot, where two axes are represented. axis dim1 explains 32% of the total variance, and axis dim2 accounts for 20.7%, giving a cumulative total of 52.7% of the overall inertia. the colored dots represent the samples, coded according to depth, with a gradient ranging from blue at the base of the sequence to orange at the top. the black arrows represent the geochemical variables, with their direction indicating correlation with the axes, and their length reflecting the strength of that correlation. the samples cluster into units (u1b, u2, u4b, u7b, u8, u9, and u5c), highlighting their relationships with certain elemental variables. the first dimension (dim1), which explains 32% of the total variance, contrasts two groups. on the left side, there is a positive correlation between calcium (ca), sulfur (s), and manganese (mn) with the samples from units u1b and u2. calcium and sulfur reflect carbonate and evaporite deposits. their joint enrichment suggests carbonate deposits associated with hydrological fluctuations of the water table. on the opposite side, to the right, titanium (ti), potassium (k), aluminum (al), and magnesium (mg) show a positive correlation with the samples from units u7b and u8. titanium, of continental origin, is mainly linked to coarse detrital inputs, while potassium and aluminum, associated with clay minerals, reflect finer sediment inputs. this elemental grouping characterizes an alluvial minerogenic detrital dynamic. the second dimension (dim2), which accounts for 20.7% of the variance, separates two trends. in the upper part, iron (fe) and rubidium (rb) show a positive 98 saadi f. et al. silty unit u2. this unit, about 1 meter thick, is characterized by predominantly fine deposits (over 80% silt), indicating a stable sedimentary environment influenced by low-energy hydrological dynamics. the greenish-grey color (10yr 7/2), the massive polyhedral structure of the deposit, and a high organic matter content (over 30%) confirm the presence of active hydromorphic pedogenetic processes associated with a high, quasipermanent fluvial aquifer, during sedimentation. these features point to a prolonged period of soil exposure, consistent with a phase of relative landscape stability. the sedimentological characteristics, confirmed by associated grain-size and geochemical analyses, suggest a low-energy depositional environment with limited aridity, supporting the hypothesis of a more humid climate during this period. available paleoenvironmental and paleoclimatic data on mis 3 in morocco, although limited, reinforce these observations. in the southern part of the country, geomorphological analyses of the fluvial systems of the wadi tamadroust and wadi noun reveal the accumulation of lacustrine deposits dating between 50 and 30 ka bp. these findings indicate low-energy fluvial activity during mis 3, in a relatively humid climatic context (weisrock et al., 2006). at the regional scale, alluvial archives from the falémé valley in senegal also document a high load of fine sediments and progressive aggradation of the riverbed during mis 3 and 2 (rasse northern africa. this interpretation is supported by data from the wintimdouine cave stalagmite, located about 200 km west of akka and 30 km north of agadir (ait brahim et al., 2017; ait brahim et al., 2023). isotopic analysis of this karst archive reveals a period of high rainfall between 84 and 77 ka bp, during the late pleistocene, reflecting intensified precipitation and regional runoff. the variability of δ¹³c and δ¹⁸o, with more negative values around 80 ka and more positive values near 73 ka, suggests that both proxies respond to the same orbitalscale climatic forcing (ait brahim et al., 2023). meanwhile, records from dim cave in southern turkey show a peak in detrital input during the mis 5amis 4 transition (81-70 ka), associated with increased erosion, surface weathering, and progressive mineralogical changes (paine et al., 2024). these developments indicate a decline in regional moisture availability, followed by a pronounced aridity peak after 74 ka, corresponding to a rapid transition to intense cold and dry conditions observed across the northern hemisphere's paleoclimatic archives. 5.2. mis 3 (ca. 60-30 ka): evidence of fluvial dynamics and relationship to humid/arid fluctuations. around 40.500 ± 2.400 years ago, during marine isotope stage 3 (mis 3), the akka plain experienced a new phase of aggradation (fig. 9), represented by the 99 fig. 8 results of the principal component analysis (pca) performed on the akka geochemical dataset. colored areas associated with clusters of projected samples emphasize the hydro-sedimentary and environmental contexts corresponding to each correlation group. high-resolution morpho-sedimentary and paleoenvironmental evolution of wadi akka ... north, in morocco particularly in the sedimentary records of the noun, assaka, and kert rivers, as well as in the moulouya basin, where indicators of hydrological reactivation and hydromorphy appear between 11.500 and 10.800 cal bp (ouammou, 1993; boudad et al., 2003; mathieu et al., 2004; zielhofer et al., 2008). despite the limited dating of alluvial archives in some areas of southern morocco, such as thocse from the wadi noun (weisrock et al., 1991), and the scarcity of data from saharan fluvial systems in this region, the deposits from the akka plain represent the first clear and well-dated evidence of hydrological dynamics associated with the african humid period (ahp) in southern morocco. 5.4. early holocene / african humid period 11.5-8 ka bp this phase, dated between 10.520 and 9.591 cal bp, begins with a marked incision of about 1.5 m, cutting into the previous phase as well as the underlying pleistocene formations (fig. 9). it is followed by a fine alluvial aggradation reaching a thickness of 2 m, represented by unit u4. this phase is part of the early holocene dynamics, characterized by a progressive intensifiet al., 2020) (fig. 10). these observations are further supported by the work of preusser et al. (2002), who reported an absence of aeolian remobilization in the wahiba sands region of oman (eastern arabia) between 64 and 22 ka bp, indicating a prolonged humid phase between 58 and 32 ka bp. 5.3. late pleistocene / younger dryas (15-11.5 ka): fluvial reactivation and early signs of the african humid period this phase (fig. 9), dated between 11.428 and 10.520 cal bp, begins with a clear incision of the riverbed on the left bank, followed by fine alluvial aggradation forming unit u3, with a thickness ranging from 1.5 to 2 meters. this sequence reflects fluctuating hydrological dynamics: at its base, the deposits indicate a low-energy fluvio-palustrine environment, which gradually transitions to conditions still dominated by low energy but intermittently disrupted by brief, more powerful hydrological events, as evidenced by the localized presence of coarse sand layers interpreted as the result of sudden flood events. similar dynamics have been documented further 100 fig. 9 model of the geomorphological and paleoenvironmental evolution of the akka plain to since mis 5b, phases 5a, 5b and 7 present an imprecise chronology due to the lack of carbonaceous material within the sedimentary units. saadi f. et al. in valley bottoms, the formation of organic-rich soils associated with hygro-hydrophilous vegetation, and the presence of weakly active alluvial channels. the localized presence of melanopsis shells associated with tubular tufa deposits (fig. 5c) indicates slow and perennial flow in a freshwater environment saturated with calcium bicarbonate. this interpretation is supported by several geochemical indicators (fig. 7) pointing to very low-energy conditions in a hydromorphic environment with high water stability. the observed oxidation deposit shows a subsequent partial drying of cation of regional humidity, corresponding to the first manifestations of the last african humid period (ahp). the sedimentological and geochemical characteristics of this sequence indicate a low-energy fluvial system, favorable to the development of stable marshy environments. the abundance of authigenic organic matter deposits (peat), the accumulation of carbonates (tufa), and the high silt content point to persistently humid climatic conditions, under the effect of increased and more evenly distributed rainfall throughout the year. this hydrological context promoted the expansion of wetlands 101 fig. 10 comparison of environmental and climatic records during the late pleistocene (mis 5b) and the holocene in north africa. chronology is expressed in calibrated years before present (cal bp). blue bands represent humid periods, while yellow bands indicate arid environmental phases. a) paleoclimatic δ¹³c record from speleothems in wintimdouine (ait brahim et al. 2023), b) paleoclimatic δ¹⁸o record from speleothems in wintimdouine (ait brahim et al., 2023), c) mg/ca ratio curve as a sea surface temperature (sst) proxy from planktonic foraminifera shells (globigerinoides ruber) (parker et al., 2016), d) precipitation index for the western mediterranean basin derived from speleothems from chaara cave (ait brahim et al., 2019), e) summer and winter insolation curves at 40°n (berger & loutre, 1991), f) north atlantic ice-rafted debris records showing both tuned and original datasets, with numbered bond events chronology (bond et al., 2001), g) paleoenvironmental records from the niayes peat bog, northern senegal (ndiaye et al., 2022), h) climatic reconstructions from fossil diatoms in paleolakes in central sahara, chad (yacoub et al., 2023), i) paleoenvironmental records from the charef river, northern morocco (depreux et al., 2022; depreux et al., 2021), j) environmental records from the takarkori river, southwestern libya (cremaschi et al., 2014), k) environmental records from the yami river, sahara, western africa (lespez et al., 2011), l) holocene paleoenvironmental record from the middle drâa basin (saadi et al., 2024), m) paleoenvironmental archives from the akka plain (this study). question marks in the akka sequence highlight phases with chronological uncertainty. high-resolution morpho-sedimentary and paleoenvironmental evolution of wadi akka ... truncations and hiatuses, suggesting a transition to more arid conditions, accompanied by high fluvial energy. three distinct phases are identified in the akka plain during this period: phase 5, subdivided into three subphases (5a, 5b, and 5c), as well as phases 6 and 7. these different phases illustrate a marked variability in fluvial dynamics and climatic conditions, typical of the middle holocene (renssen et al., 2003; roberts et al., 2011; fletcher et al., 2013; berger et al., 2016) phase 5a: fluvial incision and erosive dynamics the first sub-phase, corresponding to unit u5a, is marked by significant fluvial incision (fig. 9), estimated between 1 and 1.5 meters deep, cutting into the alluvium of the previous phase. grain-size and geochemical analyses reveal a notable increase in flow energy, characterized by a high proportion of coarse fractions and elevated zr/rb and si/al ratios. these markers indicate an episode of intense erosion, resulting in a negative sedimentary record (erosive truncation), probably linked to episodic alluvial discharges and significant aeolian input. this abrupt change reflects a substantial drop in the alluvial water table and hydrological instability in the akka plain. this event could be associated with a regional arid phase that occurred around 9 300 cal bp, linked to the global rapid climate change (rcc) event of that period. similar dynamics have been observed in the moulouya basin, where a nearly synchronous depositional hiatus has been identified (depreux et al., 2022). phase 5b: fluvial aggradation and return to humid conditions. the following sub-phase, corresponding to unit u5b, is marked by a resumption of fluvial aggradation within a more stable hydromorphic context. flow conditions became more regular, favoring a rise in the alluvial water table and sediment accumulation. geochemical indicators reveal high organic matter content (up to 30%), low carbonate concentration, predominance of fine particles, and a low rb/sr ratio, pointing to a temporary return to a humid, low-energy fluvial environment. phase 5c: major erosive episode and return to arid conditions. the last sub-phase, dated by osl between 9.5008.500 bp and corresponding to units u5c and u5d, records a new episode of intense erosion, well preserved on both banks of the wadi akka. grain-size and geochemical data attest to this hydrological dynamic: a high proportion of coarse fractions (sands, gravels > 80%), elevated d50 and d90 values, and an accentuated zr/ rb ratio. these parameters reflect a powerful fluvial dynamic in a high-energy environment. similarly, low rb/sr ratios suggest limited pedological alteration, while the low organic matter content indicates sedimentation dominated by detrital minerogenic inputs, with minimal biological contribution. these features are typical of more arid climatic conditions. this phase marks the transition between the early and middle holocene and reflects a major change in sedimentary dynamics and paleoenvironmental conditions. it remains poorly documented in most maghrebian fluvial archives (zielhofer et al., 2008; depreux et al., 2021).this regional sedimentary hiatus appears to result from major hydro-geomorphological disturbances affectthe channel bed. at the regional scale, comparable sequences have been identified in the alluvial archives of the wadi noun, characterized by fluvio-lacustrine deposits rich in organic matter, stagnant waters, and evidence of pedogenesis (weisrock, 1980; chennaoui et al., 2005; weisrock et al., 2006). in the moulouya basin, sedimentary and palynological data reveal the presence of marshy environments and carbonate tufa formation between 10,800 and 9 000 cal bp, associated with strong hydrological stability (depreux et al., 2021). these environments reflect prolonged humid conditions, confirmed by the identification of several successive palynological biozones, the oldest indicating the presence of shallow lakes before 10.600 cal bp, followed by a marked aridification episode around 5.000 cal bp (limondin-lozouet et al., 2013). beyond the moroccan context, early holocene humid sequences are well documented at the north african scale. in the niyes peat bogs, senegal (fig. 10), archives reveal a more wooded landscape, a high water table, and a strengthening of the monsoon around 9.500 cal bp (ndiaye et al., 2022). data from lake chad also show a rise in lake level between 9.500 and 6.500 cal bp, characterized by low δ¹⁸o values and low conductivity, pointing to a positive water balance. in the tadrart acacus massif, southern libya, the reactivation of springs is attested by travertine deposits dated to around 9.500 cal bp (fig. 10j), associated with a renewed activity of large saharan hydrological systems (cremaschi et al., 2010; cremaschi & zerboni, 2011). further indications of the african humid period are found in saharan paleo-lakes such as hassi el mejnah and sebkha mellala in tunisia, which show an abrupt transition from arid to lacustrine conditions around 10.500 cal bp. these data collectively mark a hydrological optimum, particularly in high-latitude regions (fontes et al., 1985; gasse et al., 1990; gasse, 2002). these records reflect increased regional and supra -regional humidity, driven by enhanced precipitation resulting from intensified summer insolation around 12 ka cal bp (berger & loutre, 1991). this insolation peak caused a northward migration of the intertropical convergence zone (itcz), which shifted approximately 500 to 800 km beyond its current position (petit-maire et al., 1995; gasse, 2000; maley & vernet, 2013). this shift facilitated the expansion of the west african monsoon domain, triggering significant climatic transformations across the region. the resulting increase in precipitation not only reactivated fluvial systems but also induced substantial changes in local ecosystems, promoting the development of wetter and more wooded landscapes (kutzbach, 1981; demenocal & tierney, 2012; pausata et al., 2020). it is also noteworthy that the deserts of the arabian peninsula experienced a contemporaneous humid phase during the early to mid-holocene, coinciding with these african climatic shifts (yan & petit-maire, 1994; lézine et al., 1998; fleitmann et al., 2007). this synchronicity suggests that these climatic changes had a broad geographic reach, affecting not only the sahara but also other arid regions at similar latitudes. 5.5. middle and late holocene (after 8 000 cal bp) the middle and late holocene mark a notable change in the morpho-sedimentary, hydrodynamic, and paleoenvironmental dynamics of the akka plain. this period is characterized by the appearance of numerous 102 saadi f. et al. of detrital elements (zr, si) (fig. x), low organic matter concentration, and a notable decrease in carbonates. these indicators suggest a lowering of the water table. furthermore, a significant increase in magnetic susceptibility (ms), from 9 × 10⁻⁸ to 50 × 10⁻⁸ m³/kg, indicates a change in sediment provenance, probably linked to a modification in sediment supply sources. phase 9, postdating 597 cal bp, is represented by unit u9c. it is expressed by a tufa formation containing travertine tubes, developed over alluvial deposits at higher elevation on the right bank of the wadi akka (fig. 6b). this phase is also marked by the development of a stromatolitic carbonate formation (fig. 6c), indicating a prolonged period of water abundance and stagnation. this phase, probably dated to the last five centuries, may correspond to one of the humid periods of the little ice age (lia), well documented in moroccan regional archives. for example, increased humidity is recorded around 150-300 cal bp in the ifoulki stalagmite (middle atlas; ait brahim et al., 2017),and between 300-400 cal bp in the tufa deposits of imouzzer kandar (azennoud et al., 2022). in north africa, particularly in saharan and presaharan regions, paleoenvironmental data for the late holocene remain scarce, especially in alluvial archives. a recent comprehensive study by saadi et al. (2024) in the middle basin of the wadi drâa has begun to fill this gap by integrating paleoenvironmental, paleohydrological, and archaeological archives. their work provides an initial chronological framework for the main morphodynamic and paleoenvironmental phases documented over the last 3.500 years (cal bp). most of the environmental and climatic changes recorded in fluvial system archives have often been primarily attributed to human activities, with many studies emphasizing anthropogenic influences on geomorphological processes during the late holocene (ramrath et al., 2000; oldfield et al., 2003). however, the holocene sedimentary archives of the akka plain, located in a sub-saharan region particularly sensitive to climatic fluctuations, indicate that the main environmental changes in this area are closely linked to major climatic events. the chronological and sedimentary hiatuses observed during the second half of the middle holocene and throughout the late holocene in the wadi akka archives correspond to phases of sediment truncation and intense hydro-sedimentary instability in the floodplain. these episodes reflect a morphodynamic and hydrological context characterized by periods of severe erosion and substantial destruction of earlier sedimentary deposits. 6. conclusion the sedimentary archives of the akka alluvial plain provide a valuable new reference for understanding the impacts of climate change on the continental saharan environment of north africa during the late pleistocene to holocene. this study focuses particularly on mis 5b, mis 3, and the early holocene period associated with the african humid period (ahp). employing a multidisciplinary approach including geomorphological and sedimentological field analyses, radiocarbon and osl dating, and geochemical investigations four alluvial sequences from the akka plain, a right-bank tributary of the drâa river in southern morocco, were examined. this research enabled the reconstruction of environing moroccan fluvial systems, probably in response to two rapid climate change (rcc) events that occurred around 8.200 and 7.600 cal bp in the charef basin, a tributary of the lower moulouya (depreux et al., 2022) phase 6, dated between 8.500 and 7.204 cal bp corresponds to sedimentary unit u6, and is characterized by a new phase of erosion (fig. 9), followed by a thin alluvial aggradation (less than one meter). this sequence reflects a significant decrease in sedimentation rate, suggesting a reduction in fluvial dynamics, marking an environment of low fluvial activity. phase 7 (u7 and u8) around 7.204 cal bp, begins with renewed aggradation in the alluvial plain (fig. 9), with deposits thicknesses ranging from 1 to 1.5 meters. this period records an energy shift, marked by an increase in coarse fractions and indices of aeolian contributions. these observations suggest a return to arid conditions in the region, with an environment increasingly influenced by wind action. at regional and continental scales, this phase coincides with a period of progressive aridification, well documented in many paleoenvironmental archives. in particular, data from lake yoa, located in the heart of the central sahara (chad), reveal irregular declines in lake level beginning around 7.000 cal bp, reflecting a transition to more arid landscapes. these changes are generally attributed to modifications in north atlantic atmospheric dynamics, notably a weakening or reorganization of the atlantic meridional overturning circulation (amoc). this phenomenon likely disrupted rainfall regimes across north africa, contributing to the progressive drying of sahelo-saharan wetlands (sylvestre et al., 2024). following this phase, a long sedimentary hiatus is evident from geomorphological and especially geochronological data of the akka river archive. this hiatus, extending from about 7,204 to 656 cal bp, suggests a period of hydrodynamic instability in the wadi akka, marked by incision and truncation, probably caused by one or several successive arid episodes. such interruptions are frequently observed in african fluvial deposits and are often attributed to a decline in fluvial activity at the end of the african humid period (ahp) (lespez et al., 2011; depreux et al., 2021). meanwhile, sahelian and sudanian regions experienced increasing aridity between about 5.000 and 3.000 cal bp (demenocal et al., 2000; lézine et al., 2005; gasse, 2000), leading to the southward shift of major vegetation zones toward their modern limits. this climatic drought phase also corresponds to the intensification of aeolian processes, particularly in the inner niger delta and its surroundings (makaske, 1998), which probably caused the erosion of the rare wetter fluvial records of the late holocene, identified elsewhere in the upstream basin of the drâa (saadi et al., 2024). in the maghreb, this transition is reflected by increased episodes of torrential runoff and alluvial crises, indicating progressive regional aridification (faust et al., 2004; weisrock et al., 2006; saadi et al., 2024). 5.6. late holocene / little ice age this interval marks a significant change in the sedimentation regime, following a long sedimentary hiatus in the akka plain archives. phase 8, dated between 656 and 597 cal bp, is characterized by marked fluvial aggradation, reaching about 1 meter in thickness. this sequence reflects arid environmental conditions, evidenced by a high content 103 high-resolution morpho-sedimentary and paleoenvironmental evolution of wadi akka ... for their very helpful comments and suggestions. we also thank the poznań radiocarbon laboratory. we are grateful to the omeaa platform (umr 5600 evs and 5133 archéorient, university of lyon) for providing access to the facilities necessary for sample processing, and to the irg/evs team for their financial support. we also extend our thanks to e. rafins and m. payet for preparing the luminescence (osl) samples. references ait brahim y.a., cheng h., sifeddine a., wassenburg j.a., cruz f.w., khodri m., sha l., pérez-zanón n., beraaouz e.h., apaéstegui j. (2017) speleothem records decadal to multidecadal hydroclimate variations in southwestern morocco during the last millennium. earth and planetary science letters, 476, 1-10. doi: 10.1016/j.epsl.2017.07.045 ait brahim y., wassenburg j.a., sha l., cruz f.w., deininger m., sifeddine a., bouchaou l., spötl c., edwards r.l., cheng h. (2019) north atlantic ice ‐rafting, ocean and atmospheric circulation during the holocene: insights from western mediterranean speleothems. geophysical research letters, 46(13), 7614-7623. doi: 10.1029/2019gl082405 ait brahim y.a., sha l., wassenburg j.a., azennoud k., cheng h., cruz f.w., bouchaou l. (2023) the spatiotemporal extent of the green sahara during the last glacial period. iscience, 26(7) 107018. doi: 10.1016/j.isci.2023.107018 aitken m.j. (1998) an introduction to optical dating: the dating of quaternary sediments by the use of photon-stimulated luminescence. oxford, new york, oxford university press, pp. 267. doi: 10.1017/s0016756899551777 azennoud k., baali a., ait brahim y.a., ahouach y., hakam o. (2022) climate controls on tufa deposition over the last 5000 years: a case study from northwest africa. palaeogeography, palaeoclimatology, palaeoecology, 586, 110767. doi: 10.1016/j.palaeo.2021.110767 baqloul a., schefuß e., kölling m., dupont l., groeneveld j., zhao x., reddad h., bouchaou l., bouimetarhan i. (2021) climate and land-use effects on hydrological and vegetation signals during the last three millennia: evidence from sedimentary leaf waxes in southwestern morocco. the holocene, 31(5), 699-708. doi: 10.1177/0959683620988053 bartz m., rixhon g., duval m., arnold l. j., demuro m., king g., álvarez-posada c., parés j.m., brückner h. (2018) une approche multi-méthodes originale: l’utilisation combinée de la résonance de spin électronique, de la luminescence et du paléomagnétisme pour reconstituer l’évolution quaternaire de la basse moulouya (ne du maroc). bereiter b., lüthi d., siegrist m., schüpbach s., stocker t.f., fischer h. (2012) mode change of millennial co2 variability during the last glacial cycle associated with a bipolar marine carbon seesaw. proceedings of the national academy of sciences, 109(25), 9755-9760. doi: 10.1073/pnas.1204069109 berger a., loutre m.-f. (1991) insolation values for the climate of the last 10 million years. quaternary 104 saadi f. et al. mental and morpho-hydrosedimentary conditions over five distinct phases, spanning more than 82,900 years, thereby providing new insights into the climatic and hydrological dynamics of the region.  around 82.9 ka (mis 5b), the akka plain underwent a phase of high-energy braided fluvial activity, marked by coarse gravel deposition and significant lateral instability, under a humid climatic regime associated with the end of the last interglacial.  during mis 3 (~40.5 ± 2.4 ka), fine-grained aggradation occurred under low-energy hydrological conditions, supported by geochemical proxies (e.g., high rb/sr ratios, organic-rich horizons), reflecting enhanced soil development and relatively humid conditions.40.5 ± 2.4 ka.  between 11.428 and 10.260 cal bp, a phase of silty aggradation marks the early african humid period (ahp) in the wadi akka alluvial records, indicating humid conditions with low hydrodynamic energy.  between 10.260 and 9.500 cal bp, the persistence of humid and stable conditions is evidenced by tufa and peat accumulation, and the presence of aquatic fauna (e.g., melanopsis), suggesting perennial freshwater environments and regional landscape stability. between 9.500 to 8.500 cal bp, the system shifted toward a more dynamic regime, marked by torrential flows, coarse sediment input, and aeolian contributions, revealing a phase of increased climatic variability and sedimentary instability within the ahp.  a return to wetter conditions is suggested around 7.204 cal bp, evidenced by silty aggradation and tufa facies, following a poorly documented but morphodynamically active interval dominated by incision and erosion.the most recent period, between 656 and 579 cal bp, signals a significant change in sedimentation consistent with arid conditions. however, after 597 cal bp, a wet phase is recorded, marked by large travertine tubes and stromatolithic travertine dams. this phase likely corresponds to the last humid episode of the little ice age (lia), also associated with paleosol formation in the middle drâa basin (saadi et al., 2024). at akka, the fluvial record predominantly preserves the most humid phases of the late pleistocene and holocene, leading to an over-representation of wetter conditions in the sedimentary archive. in contrast, the middle holocene and much of the late holocene are characterized by incision and truncation events, often accompanied by gravel deposits resulting from highly erosive fluvial processes. these dynamics account for the frequent sedimentary hiatuses and discontinuities observed in the fluvial systems. such periods appear to be linked to rapid climatic fluctuations and a general trend of aridification driven by orbital forcing. nevertheless, this extended interval remains poorly constrained chronologically at akka and will require substantial future efforts in geochronology, particularly through osl dating, contingent upon achieving sufficient bleaching of the alluvial deposits under study. acknowledgments this study was carried out as part of the phc toubkal/21/132 project (campus france) 45924wj, as well as the appi-lyon2 "transmar" project. we would like to express our gratitude to the editor and reviewers requires mediterranean winter rainfall. proceedings of the national academy of sciences, 118(23), e2024898118. doi: 10.1073/pnas.2024898118 chennaoui k., nahid a., argant j., noçairi m., malek f., sahbi h. (2005) etude intégrée dʼun enregistrement morphosédimentaire anthropique holocène: lʼescargotière de tissouirine (atlas atlantique, maroc) revue de paléobiologie, 24(2), 541-550. choubert g., ennadifi y. (1970) carte géologique du flanc sud de l’anti-atlas occidental et des plaines du dra: akka-tafagount-tata. service géologique du maroc. cremaschi m., zerboni a. (2011) human communities in a drying landscape: holocene climate change and cultural response in the central sahara. landscapes and societies: selected cases, 67-89. doi: 10.1007/978-90-481-9413-1_5 cremaschi m., zerboni a., spötl c., felletti f. (2010) the calcareous tufa in the tadrart acacus mt.(sw fezzan, libya): an early holocene palaeoclimate archive in the central sahara. palaeogeography, palaeoclimatology, palaeoecology, 287(1-4), 8194. doi: 10.1016/j.palaeo.2010.01.019 cremaschi m., zerboni a., mercuri a.m., olmi l., biagetti s., di lernia s. (2014) takarkori rock shelter (sw libya): an archive of holocene climate and environmental changes in the central sahara. quaternary science reviews, 101, 36-60. doi: 10.1016/j.quascirev.2014.07.004 dearing j. (1999) magnetic susceptibility. environmental magnetism: a practical guide, 35-62. demenocal p., ortiz j., guilderson t., adkins j., sarnthein m., baker l., yarusinsky m. (2000) abrupt onset and termination of the african humid period: rapid climate responses to gradual insolation forcing. quaternary science reviews, 19(1-5), 347-361. demenocal p.b., tierney j.e. (2012) green sahara: african humid periods paced by earth’s orbital changes. nature education knowledge, 3(10), 12. depreux b. (2021) dynamiques des systèmes fluviaux dans le bassin de la moulouya (maroc) à l’holocène: morphogenèse fluviale, changements climatiques et occupations humaines. montpellier 3. depreux b., lefèvre d., berger j.-f., segaoui f., boudad l., el harradji a., degeai j.-p., limondinlozouet n. (2021) alluvial records of the african humid period from the nw african highlands (moulouya basin, ne morocco). quaternary science reviews, 255, 106807. doi: 10.1016/j.quascirev.2021.106807 depreux b., berger j.-f., lefèvre d., wackenheim q., andrieu-ponel v., vinai s., degeai j.-p., el harradji a., boudad l., sanz-laliberté s. (2022) first fluvial archive of the 8.2 and 7.6-7.3 ka events in north africa (charef river, high plateaus, ne morocco). scientific reports, 12(1), 7710. doi: 10.1038/s41598-022-11353-y el amrani m., macaire j.-j., zarki h., bréhéret j.-g., fontugne m. (2008) contrasted morphosedimentary activity of the lower kert river (northeastern morocco) during the late pleistocene and the holocene. possible impact of bioclimatic variations and human action. comptes rendus. géoscience, science reviews, 10(4), 297-317. doi: 10.1016/0277-3791(91)90033-q berger j.-f., delhon c., magnin f., bonte s., peyric d., thiebault s., guilbert r., beeching a. (2016) a fluvial record of the mid-holocene rapid climatic changes in the middle rhone valley (espeluchelalo, france) and of their impact on late mesolithic and early neolithic societies. quaternary science reviews, 136, 66-84. doi: 10.1016/j.quascirev.2015.11.019 blott s.j., pye k. (2001) gradistat: a grain size distribution and statistics package for the analysis of unconsolidated sediments. earth surface processes and landforms, 26(11), 1237-1248. doi: 10.1002/esp.261 bond g., kromer b., beer j., muscheler r., evans m. n., showers w., hoffmann s., lotti-bond r., hajdas i., bonani g. (2001) persistent solar influence on north atlantic climate during the holocene. science, 294(5549), 2130-2136. doi: 10.1126/science.1065680 boudad l., kabiri l., weisrock a., wengler l., fontugne m., el maataoui m., makayssi a., vernet j.l. (2003) les formations fluviatiles du pléistocène supérieur et de l’holocène dans la "plaine" de tazoughmit (oued rheris, piémont sud-atlasique de goulmina, maroc). quaternaire, 14(3), 139-154. doi: 10.3406/quate.2003.1738 bravard j.-p. (1983) les sédiments fins des plaines d’inondation dans la vallée du haut-rhône. revue de géographie alpine, 71(4), 363-379. doi: 10.3406/rga.1983.2543 brennan b.j., lyons r.g., phillips s.w. (1991) attenuation of alpha particle track dose for spherical grains. international journal of radiation applications and instrumentation. part d. nuclear tracks and radiation measurements, 18(1-2), 249-253. doi: 10.1016/1359-0189(91)90119-3 burrough s.l., thomas d.s.g. (2013) central southern africa at the time of the african humid period: a new analysis of holocene palaeoenvironmental and palaeoclimate data. quaternary science reviews, 80, 29-46. doi: 10.1016/j.quascirev.2013.08.001 campbell j.f.e., fletcher w.j., joannin s., hughes p. d., rhanem m., zielhofer c. (2017) environmental drivers of holocene forest development in the middle atlas, morocco. frontiers in ecology and evolution, 5, 113. doi: 10.3389/fevo.2017.00113 castañeda i.s., mulitza s., schefuß e., lopes dos santos r.a., sinninghe damsté j.s., schouten s. (2009) wet phases in the sahara/sahel region and human migration patterns in north africa. proceedings of the national academy of sciences, 106(48), 20159-20163. doi: 10.1073/pnas.0905771106 cheddadi r., fady b., françois l., hajar l., suc j., huang k., demarteau m., vendramin g.g., ortu e. (2009) putative glacial refugia of cedrus atlantica deduced from quaternary pollen records and modern genetic diversity. journal of biogeography, 36 (7), 1361-1371. doi: 10.1111/j.1365-2699.2008.02063.x cheddadi r., carré m., nourelbait m., françois l., rhoujjati a., manay r., ochoa d., schefuss e. (2021) early holocene greening of the sahara 105 high-resolution morpho-sedimentary and paleoenvironmental evolution of wadi akka ... quaternary science: published for the quaternary research association, 21(3), 259-269. doi: 10.1002/jqs.970 heiri o., lotter a.f., lemcke g. (2001) loss on ignition as a method for estimating organic and carbonate content in sediments: reproducibility and comparability of results. journal of paleolimnology, 25, 101110. doi: 10.1023/a:1008119611481 helmens k.f. (2014) the last interglacial-glacial cycle (mis 5-2) re-examined based on long proxy records from central and northern europe. quaternary science reviews, 86, 115-143. doi: 10.1016/j.quascirev.2013.12.012 ibouhouten h., zielhofer c., mahjoubi r., kamel s., linstädter j., mikdad a., bussmann j., werner p., härtling j.w., fenech k. (2010) archives alluviales holocènes et occupation humaine en basse moulouya (maroc nord-oriental). géomorphologie: relief, processus, environnement, 16(1), 41-56. doi: 10.4000/geomorphologie.7812 jones a.f., macklin m.g., brewer p.a. (2012) a geochemical record of flooding on the upper river severn, uk, during the last 3750 years. geomorphology, 179, 89-105. doi: 10.1016/j.geomorph.2012.08.003 klasen n., fischer p., lehmkuhl f., hilgers a. (2015) luminescence dating of loess deposits from the remagen-schwalbenberg site, western germany. geochronometria, 42(1). doi: 10.13140/rg.2.2.29534.64328 kröpelin s., verschuren d., lézine a.-m., eggermont h., cocquyt c., francus p., cazet j.-p., fagot m., rumes b., russell j. m. (2008) climate-driven ecosystem succession in the sahara: the past 6000 years. science, 320(5877), 765-768. doi: 10.1126/science.1154913 kutzbach j.e. (1981) monsoon climate of the early holocene: climate experiment with the earth’s orbital parameters for 9000 years ago. science, 214(4516), 59-61. doi: 10.1126/science.214.4516.59 lauterbach s., brauer a., andersen n., danielopol d.l., dulski p., hüls m., milecka k., namiotko t., obremska m., von grafenstein u. (2011) environmental responses to lateglacial climatic fluctuations recorded in the sediments of pre-alpine lake mondsee (northeastern alps). journal of quaternary science, 26(3), 253-267. doi: 10.1002/jqs.1448 lefèvre d. (1985) les formations plio-pléistocènes du bassin de ksabi (moyenne moulouya, maroc). bordeaux 1. lespez l., le drezen y., garnier a., rasse m., eichhorn b., ozainne s., ballouche a., neumann k., huysecom e. (2011) high-resolution fluvial records of holocene environmental changes in the sahel: the yamé river at ounjougou (mali, west africa). quaternary science reviews, 30(5-6), 737 -756. doi: 10.1016/j.quascirev.2010.12.021 lézine a.-m., casanova j. (1989) pollen and hydrological evidence for the interpretation of past climates in tropical west africa during the holocene. quaternary science reviews, 8(1), 45-55. doi: 10.1016/0277-3791(89)90020-6 lézine a.-m., saliege j.-f., robert c., wertz f., inizan 340(8), 533-542. doi: 10.1016/j.crte.2008.05.004 esri (2009) "world imagery", accessed 2020-06-05. www.arcgis.com/home/item.html?id=10df2279f968 4e4a9f6a7f08febac2a9 faust d., zielhofer c., escudero r.b., del olmo f.d. (2004) high-resolution fluvial record of late holocene geomorphic change in northern tunisia: climatic or human impact? quaternary science reviews, 23(16-17), 1757-1775. doi: 10.1016/j.quascirev.2004.02.007 fleitmann d., burns s.j., mangini a., mudelsee m., kramers j., villa i., neff u., al-subbary a.a., buettner a., hippler d. (2007) holocene itcz and indian monsoon dynamics recorded in stalagmites from oman and yemen (socotra). quaternary science reviews, 26(1-2), 170-188. doi: 10.1016/j.quascirev.2006.04.012 fletcher w.j., debret m., goñi m.f.s. (2013) midholocene emergence of a low-frequency millennial oscillation in western mediterranean climate: implications for past dynamics of the north atlantic atmospheric westerlies. the holocene, 23(2), 153166. doi: 10.1177/0959683612460783 foley j.a., coe m.t., scheffer m., wang g. (2003) regime shifts in the sahara and sahel: interactions between ecological and climatic systems in northern africa. ecosystems, 6(6), 524-532. doi: 10.1007/s10021-002-0227-0 fontes j.c., gasse f., callot y., plaziat j.c., carbonel p., dupeuble p.a., kaczmarska i. (1985) freshwater to marine-like environments from holocene lakes in northern sahara. nature, 317(6038), 608610. doi: 10.1038/317608a0 galbraith r.f., roberts r.g., laslett g.m., yoshida h., olley j.m. (1999) optical dating of single and multiple grains of quartz from jinmium rock shelter, northern australia: part i, experimental design and statistical models. archaeometry, 41(2), 339-364. doi: 10.1111/j.1475-4754.1999.tb00987.x gasse f. (2000) hydrological changes in the african tropics since the last glacial maximum. quaternary science reviews, 19(1-5), 189-211. doi: 10.1016/s0277-3791(99)00061-x gasse f. (2002) diatom-inferred salinity and carbonate oxygen isotopes in holocene waterbodies of the western sahara and sahel (africa). quaternary science reviews, 21(7), 737-767. doi: 10.1016/s0277-3791(01)00125-1 gasse f., téhet r., durand a., gibert e., fontes j.-c. (1990) the arid-humid transition in the sahara and the sahel during the last deglaciation. nature, 346(6280), 141-146. doi: 10.1038/346141a0 guérin g., mercier n., adamiec g. (2011) dose-rate conversion factors: update. ancient tl, 29(1), 5-8. doi: 10.26034/la.atl.2011.443 guérin g., mercier n., nathan r., adamiec g., lefrais y. (2012) on the use of the infinite matrix assumption and associated concepts: a critical review. radiation measurements, 47(9), 778-785. doi: 10.1016/j.radmeas.2012.04.004 haslett s.k., smart c.w. (2006) late quaternary upwelling off tropical nw africa: new micropalaeontological evidence from odp hole 658c. journal of 106 saadi f. et al. mullins c.e. (1977) magnetic susceptibility of the soil and its significance in soil science-a review. journal of soil science, 28(2), 223-246. doi: 10.1111/j.1365-2389.1977.tb02232.x murray a.s., wintle a.g. (2000) luminescence dating of quartz using an improved single-aliquot regenerative-dose protocol. radiation measurements, 32 (1), 57-73. doi: 10.1016/s1350-4487(99)00253-x ndiaye a., bentaleb i., favier c., fourel f., sebag d., fall m., giresse p., diouf b. (2022) reconstruction of the holocene climate and environmental changes of niayes peat bog in northern coast of senegal (nw africa) based on stable isotopes and charcoals analysis. quaternary science reviews, 289, 107609. doi: 10.1016/j.quascirev.2022.107609 oldfield f., asioli a., accorsi c. a., mercuri a.m., juggins s., langone l., rolph t., trincardi f., wolff g., gibbs z. (2003) a high resolution late holocene palaeo environmental record from the central adriatic sea. quaternary science reviews, 22(24), 319-342. doi: 10.1016/s0277-3791(02)00088-4 ouammou a. (1993) evolution morphologique récente du bas plateau de tiznit (maroc). nancy 2. pachur h-j, hoelzmann p. (1991) paleoclimatic implications of late quaternary lacustrine sediments in western nubia, sudan. quaternary research, 36 (3), 257-276. doi: 10.1016/0033-5894(91)90002-m pachur h-j, röper h.-p., kroepelin s., goschin m. (1987) late quaternary hydrography of the eastern sahara. paine a.r., baldini j.u.l., ünal-imer e., wadsworth f.b., iveson a.a., humphreys m.c.s., brown r.j., müller w., ottley c.j. (2024) abrupt climate change at the mis 5/4 transition recorded in a speleothem from the eastern mediterranean. quaternary science reviews, 339, 108841. doi: 10.1016/j.quascirev.2024.108841 parker a.o., schmidt m.w., jobe z.r., slowey n.c. (2016) a new perspective on west african hydroclimate during the last deglaciation. earth and planetary science letters, 449, 79-88. doi: 10.1016/j.epsl.2016.05.038 passega r. (1964) grain size representation by cm patterns as a geologic tool. journal of sedimentary research, 34(4), 830-847. doi: 10.1306/74d711a4-2b21-11d78648000102c1865d pausata f.s.r., gaetani m., messori g., berg a., de souza d. m., sage r.f., demenocal p.b. (2020) the greening of the sahara: past changes and future implications. one earth, 2(3), 235-250. doi: 10.1016/j.oneear.2020.03.002 petit-maire n. (1989) interglacial environments in presently hyperarid sahara: palaeoclimatic implications. in paleoclimatology and paleometeorology: modern and past patterns of global atmospheric transport (637-661) springer. doi: 10.1007/978-94-009-0995-3_27 petit-maire n. (2021) sahara: les grands changements climatiques naturels. éditions errance. petit-maire n., riser j. (1981) holocene lake deposits and palaeoenvironments in central sahara, northeastern mali. palaeogeography, palaeoclimatom.-l. (1998) holocene lakes from ramlat assab’atayn (yemen) illustrate the impact of monsoon activity in southern arabia. quaternary research, 50(3), 290-299. doi: 10.1006/qres.1998.1996 lézine a.-m., dupless, j.-c., cazet j.-p. (2005) west african monsoon variability during the last deglaciation and the holocene: evidence from fresh water algae, pollen and isotope data from core kw31, gulf of guinea. palaeogeography, palaeoclimatology, palaeoecology, 219(3-4), 225-237. doi: 10.1016/j.palaeo.2004.12.027 lézine a.-m., hély c., grenier c., braconnot p., krinner g. (2011) sahara and sahel vulnerability to climate changes, lessons from holocene hydrological data. quaternary science reviews, 30(21-22), 3001-3012. doi: 10.1016/j.quascirev.2011.07.006 lézine a.-m., kageyama m., bassinot f. (2023) data and models reveal humid environmental conditions during mis 3 in two of the world’s largest deserts. comptes rendus. géoscience, 355(s2), 229-246. doi: 10.5802/crgeos.240 lghamour m., karrat l., picotti v., hajdas i., haghipour n., guidobaldi g., heeb k.w., gourari l. (2024) late pleistocene to holocene alluvial deposits of the inaouène valley and their paleoenvironmental significance (north morocco). quaternary science reviews, 344, 108941. doi: 10.1016/j.quascirev.2024.108941 liang l., sun y., beets c.j., prins m.a., wu f., vandenberghe j. (2013) impacts of grain size sorting and chemical weathering on the geochemistry of jingyuan loess in the northwestern chinese loess plateau. journal of asian earth sciences, 69, 177-184. doi: 10.1016/j.jseaes.2012.12.015 limondin-lozouet n., haddoumi h., lefèvre d., ghamizi m., aouraghe h., salel t. (2013) holocene molluscan succession from ne morocco: palaeoenvironmental reconstruction and biogeographical implications. quaternary international, 302, 61-76. doi: 10.1016/j.quaint.2012.11.036 linnaeus c. (1789) systema naturae per regna tria naturae, secundum classes, ordines, genera, species; cum characteribus, differentiis, synonymis, locis (vol. 1). apud jb delamolliere. makaske b. (1998) anastomosing rivers: a review of their classification, origin and sedimentary products. earth-science reviews, 53(3-4), 149-196. doi: 10.1016/s0012-8252(00)00038-6 maley j., vernet r. (2013) peuples et évolution climatique en afrique nord-tropicale, de la fin du néolithique à l’aube de l’époque moderne. afriques. débats, méthodes et terrains d’histoire, 04. doi: 10.4000/afriques.1209 mathieu j., weisrock a., wengler l., brochier j.e., even g., fontugne m., mercier n., ouammou a., senegas f., valladas h. (2004) holocene deposits in the lower section of the assaka wadi, south morocco: preliminary results. quaternaire, 15(1-2), 207-218. mercier n., falguères c. (2007) field gamma doserate measurement with a nai (tl) detector: reevaluation of the" threshold" technique. ancient tl, 25(1), 1-4. doi: 10.26034/la.atl.2007.400 107 high-resolution morpho-sedimentary and paleoenvironmental evolution of wadi akka ... material research and dating application. geochronometria, 42(1), 202-209. doi: 10.1515/geochr-2015-0022 ritchie j.c., eyles c.h., haynes c.v. (1985) sediment and pollen evidence for an early to mid-holocene humid period in the eastern sahara. nature, 314 (6009), 352-355. doi: 10.1038/314352a0 roberts n., brayshaw d., kuzucuoğlu c., perez r., sadori l. (2011) the mid-holocene climatic transition in the mediterranean: causes and consequences. the holocene, 21(1), 3-13. doi: 10.1177/0959683610388058 romero o.e., leduc g., vidal l., fischer g. (2011) millennial variability and long‐term changes of the diatom production in the eastern equatorial pacific during the last glacial cycle. paleoceanography, 26 (2). doi: 10.1029/2010pa002099 rothwell r.g., croudace i.w. (2015) twenty years of xrf core scanning marine sediments: what do geochemical proxies tell us? micro-xrf studies of sediment cores: applications of a non-destructive tool for the environmental sciences, 25-102. doi: 10.1007/978-94-017-9849-5_1 saadi f., boudad l., berger j.-f. (2024) late holocene morphosedimentary and palaeoenvironmental study of the middle drâa river basin (southeastern morocco). quaternary international, 710, 29-48. doi: 10.1016/j.quaint.2024.09.003 salvador p.-g. (2016) caractérisation des remblaiements sédimentaires de six paléochenaux de la plaine alluviale du rhône par la méthode granulométrique de passega (basses terres, ain, isère). bulletin de la société géographique de liège, 67, 107-124. doi: 10.25518/0770-7576.4492 salzmann u., waller m. (1998) the holocene vegetational history of the nigerian sahel based on multiple pollen profiles. review of palaeobotany and palynology, 100(1-2), 39-72. doi: 10.1016/s0034-6667(97)00053-5 siddall m., stocker t. f., blunier t., spahni r., mcmanus j. f., bard e. (2006) using a maximum simplicity paleoclimate model to simulate millennial variability during the last four glacial periods. quaternary science reviews, 25(23-24), 3185-3197. doi: 10.1016/j.quascirev.2005.12.014 specht n.f., claussen m., kleinen t. (2024) dynamic interaction between lakes, climate, and vegetation across northern africa during the mid-holocene. climate of the past, 20(7), 1595-1613. doi: 10.5194/cp-20-1595-2024 street-perrott f.a., hales p.e., perrott r.a., fontes j. c., switsur v.r., pearson a. (1993) late quaternary palaeolimnology of a tropical marl lake: wallywash great pond, jamaica. journal of paleolimnology, 9, 3-22. doi: 10.1007/bf00680032 sylvestre f., melles m., wennrich v., dinies m., chalié f., swingedouw d., dallmeyer a., shi x., claussen m., jaeschke a. (2024) drought events during the african humid period suggest future drying of the sahara. doi: 10.21203/rs.3.rs-5288623/v1 tadoumant s., bouimetarhan i., baqloul a., hssaisoune m., reddad h., bouchaou l. (2022) modern pollogy, palaeoecology, 35, 45-61. doi: 10.1016/0031-0182(81)90093-6 petit-maire n., riser j. (1983) sahara ou sahel. quaternaire récent du bassin de taoudenni (mali). paris: centre national de la recherche scientifique, 473. petit-maire n., riser j., blanc-vernet l., fairbridge r.w. (1983) sahara ou sahel?: quaternaire récent du bassin de taoudenni (mali). c.n.r.s., laboratoire de géologie du quaternaire, marseille. petit-maire n., sanlaville p., yan z. (1995) oscillations de la limite nord du domaine des moussons africaine, indienne, et asiatique au cours du dernier cycle climatique. bulletin de la société géologique de france, 166(2), 213-220. prescott j.r., hutton j.t. (1988) cosmic ray and gamma ray dosimetry for tl and esr. international journal of radiation applications and instrumentation. part d. nuclear tracks and radiation measurements, 14(1-2), 223-227. doi: 10.1016/1359-0189(88)90069-6 preusser f., radies d., matter a. (2002) a 160.000year record of dune development and atmospheric circulation in southern arabia. science, 296(5575), 2018-2020. doi: 10.1126/science.1069875 profe j., zolitschka b., schirmer w., frechen m., ohlendorf c. (2016) geochemistry unravels mis 3/2 paleoenvironmental dynamics at the loesspaleosol sequence schwalbenberg ii, germany. palaeogeography, palaeoclimatology, palaeoecology, 459, 537-551. doi: 10.1016/j.palaeo.2016.07.022 ramrath a., sadori l., negendank j.f.w. (2000) sediments from lago di mezzano, central italy: a record of lateglacial/holocene climatic variations and anthropogenic impact. the holocene, 10(1), 87-95. doi: 10.1191/095968300669348734 rasse m., lespez l., lebrun b., tribolo c., chevrier b., douze k., garnier a., davidoux s., hadjas i., ollier c. (2020) synthèse morpho-sédimentaire et occurences archéologiques dans la vallée de la falémé (de 80 à 5 ka; sénégal oriental): mise en évidence d’une permanence des occupations à la transition pléistocène‑holocène. quaternaire. revue de l’association française pour l’étude du quaternaire, 31/1, 71-88. doi: 10.4000/quaternaire.13181 reimer p.j., austin w.e.n., bard e., bayliss a., blackwell p.g., ramsey c.b., butzin m., cheng h., edwards r.l., friedrich m. (2020) the intcal20 northern hemisphere radiocarbon age calibration curve (0-55 cal kbp). radiocarbon, 62(4), 725757. doi: 10.1017/rdc.2020.41 renssen h., brovkin v., fichefet t., goosse h. (2003) holocene climate instability during the termination of the african humid period. geophysical research letters, 30(4), 1177. doi: 10.1029/2002gl016636 richter d., richter a., dornich k. (2013) lexsyg a new system for luminescence research. geochronometria, 40(4), 220-228. doi: 10.2478/s13386-013-0110-0 richter d., richter a., dornich k. (2015) lexsyg smart a luminescence detection system for dosimetry, 108 saadi f. et al. wintle a.g., murray a.s. (2006) a review of quartz optically stimulated luminescence characteristics and their relevance in single-aliquot regeneration dating protocols. radiation measurements, 41(4), 369-391. doi: 10.1016/j.radmeas.2005.11.001 yacoub a.n., sylvestre f., moussa a., hoelzmann p., alexandre a., dinies m., chalié f., vallet-coulomb c., paillès c., darius f. (2023) the african holocene humid period in the tibesti mountains (central sahara, chad): climate reconstruction inferred from fossil diatoms and their oxygen isotope composition. quaternary science reviews, 308, 108099. doi:10.1016/j.quascirev.2023.108099 yan z., petit-maire n. (1994) the last 140 ka in the afro-asian arid/semi-arid transitional zone. palaeogeography, palaeoclimatology, palaeoecology, 110(3-4), 217-233. doi: 10.1016/0031-0182(94)90085-x zaky a.s., de azevedo a.q., vogel h., jovane l., hamdan m., achyuthan h., frontalini f., szidat s., anselmetti f.s. (2024) climate variability in northern africa during the late holocene: a multiproxy perspective from el-beida lake (wadi el-natrun, egypt). quaternary science reviews, 337, 108801. doi: 10.1016/j.quascirev.2024.108801 zech m., zech r., zech w., glaser b., brodowski s., amelung w. (2008) characterisation and palaeoclimate of a loess-like permafrost palaeosol sequence in ne siberia. geoderma, 143(3-4), 281295. doi: 10.1016/j.geoderma.2007.11.012 zielhofer c., faust d. (2008) mid-and late holocene fluvial chronology of tunisia. quaternary science reviews, 27(5-6), 580-588. doi: 10.1016/j.quascirev.2007.11.019 zielhofer c., faust d., linstädter j. (2008) late pleistocene and holocene alluvial archives in the southwestern mediterranean: changes in fluvial dynamics and past human response. quaternary international, 181(1), 39-54. doi: 10.1016/j.quaint.2007.09.016 zielhofer c., bussmann j., ibouhouten h., fenech k. (2010) flood frequencies reveal holocene rapid climate changes (lower moulouya river, northeastern morocco). journal of quaternary science, 25(5), 700-714. doi: 10.1002/jqs.1347 len distribution and its relationship with environmental gradient in southern morocco. review of palaeobotany and palynology, 298, 104595. doi: 10.1016/j.revpalbo.2021.104595 thiel c., buylaert j.-p., murray a., terhorst b., hofer i., tsukamoto s., frechen m. (2011) luminescence dating of the stratzing loess profile (austria)testing the potential of an elevated temperature post-ir irsl protocol. quaternary international, 234(1-2), 23-31. doi: 10.1016/j.quaint.2010.05.018 tribolo c., mercier n., douville e., joron j.-l., reyss j.l., rufer d., cantin n., lefrais y., miller c.e., porraz g. (2013) osl and tl dating of the middle stone age sequence at diepkloof rock shelter (south africa): a clarification. journal of archaeological science, 40(9), 3401-3411. doi: 10.1016/j.jas.2012.12.001 wang m., zheng h., xie x., fan d., yang s., zhao q., wang k. (2011) a 600-year flood history in the yangtze river drainage: comparison between a subaqueous delta and historical records. chinese science bulletin, 56, 188-195. doi: 10.1007/s11434-010-4212-2 weisrock a.l.e. (1980) géomorphologie et paléoenvironnements de l’atlas atlantique (maroc). université de lille iii, atelier national de reproduction des thèses. weisrock a, ouammou a., hssaine a. (1991) erosion et sédimentation dans les oueds du sud-ouest marocain à l’holocène. géo physio, 22-23, 95100. weisrock a., wahl l., ouammou a., chakir l. (2006) systèmes fluviaux du sud-ouest marocain et leur évolution depuis le pléistocène supérieur. géomorphologie: relief, processus, environnement, 12(4), 229-248. weisrock a., rousseau l., reyss j.-l., falguères c., ghaleb b., bahain j.-j., beauchamp j., boudad l., mercier n., mahieux g. (2008) travertins de la bordure nord du sahara marocain: dispositifs morphologiques, datations u/th et indications paléoclimatiques. géomorphologie: relief, processus, environnement, 14(3), 153-167. doi: 10.4000/geomorphologie.6793 weldeab s., schneider r.r., kölling m., wefer g. (2005) holocene african droughts relate to eastern equatorial atlantic cooling. geology, 33(12), 981984. doi: 10.1130/g21874.1 wengler l., weisrock a., brochier j.-é., brugal j.p., fontugne m., magnin f., mathieu j., mercier n., ouammou a., reyss j.-l. (2002) enregistrement fluviatile et paléoenvironnements au pléistocène supérieur sur la bordure méridionale atlantique de l’anti-atlas (oued assaka, so marocain). quaternaire, 13(3), 179-192. doi: 10.3406/quate.2002.1710 109 ms. received: july 2, 2025 revised: september 30, 2025 accepted: october 2, 2025 available online: october 18, 2025 high-resolution morpho-sedimentary and paleoenvironmental evolution of wadi akka ... 110 imp.iandelli_piccini rapporti tra morfogenesi carsica ed evoluzione paleogeografica nelle aree costiere della toscana meridionale niccolò iandelli 1, leonardo piccini 1 1 dipartimento di scienze della terra, università degli studi di firenze; e-mail: leonardo-piccini@.unifi.it. riassunto: n. iandelli & l. piccini, rapporti tra morfogenesi carsica ed evoluzione paleogeografica nelle aree costiere della toscana meridionale. (it issn 0394-3356, 2007). nella toscana meridionale si trovano estesi affioramenti di brecce carbonatiche che presentano superfici a bassa pendenza con estesi fenomeni carsici. un’analisi morfologica ha permesso di riconoscere due tipi di superfici: spianate sommitali e terrazzi marini d’erosione. le prime sono presenti soprattutto nell’area del poggio del leccio, la cui natura permette di escludere per esse un controllo lito-strutturale. queste superfici si trovano prevalentemente intorno a 250 m di quota e in misura minore intorno a 300 m s.l.m.. i terrazzi marini si trovano invece a quote comprese tra 0 e 70 m. le forme carsiche comprendono numerose grotte le quali possono essere distinte in due tipi principali: cavità relitte, di forma grossomodo a camera, presenti soprattutto nelle zone sommitali a bassa pendenza; cavità ramificate a sviluppo orizzontale, appartenenti a due generazioni, di cui la più antica è situata intorno a 250 m di quota. sulla base delle caratteristiche del rilievo e delle cavità carsiche è stato possibile ipotizzare le principali fasi evolutive dei fenomeni carsici in relazione all’evoluzione morfotettonica di quest’area costiera. in occasione della trasgressione pliocenica, si forma probabilmente una vasta piattaforma d’erosione marina in rocce calcaree, che è poi smembrata e sollevata in modo differenziale durante il pliocene superiore e il quaternario. durante la progressiva emersione, si sviluppano forme carsiche legate alla presenza di una tavola d’acqua in prossimità della superficie della piattaforma, nonché cavità costiere ai suoi margini. il sollevamento porta porzioni di questa superficie sino a 250-300 m di quota, conservati nelle spianate sommitali a bassa pendenza del poggio del leccio. nel pleistocene medio-superiore si ha l’esumazione di cavità relitte epifreatiche più antiche e la formazione di una nuova generazione di cavità costiere in corrispondenza della zona di oscillazione eustatica del livello del mare. abstract: n. iandelli & l. piccini, relationships between karst morphogenesis and palaeogeographic evolution in coastal areas of southern tuscany. (it issn 0394-3356, 2007). in southern tuscany, close to the border with lazio region, wide outcrops of carbonate breccias (calcare cavernoso) display e relief characterised by top horizontal surfaces and slope terraces with karst landforms. morphometric analysis, based on a dtm with a resolution of 10 m, has allowed us to identify some low-gradient surfaces displaced from 0 to 300 m a.s.l.. erosional surfaces are of two different kinds: old summit surfaces and marine terraces. the formers occur mainly on poggio del leccio area, as smooth-relief areas not controlled by lythologic surfaces. presently, these surfaces are located around 250 m a.s.l., up to 300 m a.s.l., whereas marine terraces are located between 0 and 70 m a.s.l.. the most peculiar feature of this area is the occurrence of surface karst and caves that can be related to palaeo-coastal environments. caves show two different patterns: chamber-shaped relict caves, occurring mainly on low gradient surfaces, and horizontal maze caves. those of first kind can be the result of the collapse of caves formed at the water table, in a coastal platform anciently located just a few tens of meters above the sea level, similar to those of many present coastal tropical karsts. horizontal maze caves can be grouped into two generations. the first one regards only few caves located around 250 m a.s.l.. the second generation is located near the present sea level and is probably due to mixing solution in epiphreatic condition. submerged caves, occurring up to 50 m below the present s.l., must be related to sea low-stands, because vadose speleothems occur inside them. the morphologic features of the area, together with the geomorphic features of caves, indicate some of the evolutionary steps that fit well with the palaeo-geographic reconstructions proposed by authors for pliocene and pleistocene. during the pliocene transgression a wide marine platform develops on carbonate rocks. the platform is fragmented and differentially raised during late pliocene and quaternary. during the emersion of this platform, caves form at the water table just near the topographic surface, whereas flank margin caves are developed along the coast. the uplift moves some portion of this old marine platform up to 250-300 m a.s.l.. during middlelate pleistocene, relict epiphreatic caves are exhumed and destroyed by surface denudation, whereas a new generation of flank margin caves is forming in the zone of eustatic variation of sea level. parole chiave: chiave: carsismo, morfologia costiera, grotte marine, toscana meridionale, orbetello. keywords: karst, coastal morphology, sea caves, southern tuscany, orbetello. il quaternario italian journal of quaternary sciences 19(1), 2006 79-87 1. introduzione gran parte delle forme carsiche superficiali (escluse ovviamente quelle a piccola scala) e soprattutto sotterranee sono forme relitte, nel senso che si sono formate in condizioni morfologiche e climatiche, talvolta legate ad un lontano passato, diverse da quelle attuali. ciò significa che gli ambienti carsici hanno un’elevata capacità di conservazione morfologica, a causa del ridotto ruolo dei processi erosivi di modellamento. quest’elevata “inerzia” morfologica rende queste aree adatte per la ricostruzione delle principali tappe dell’evoluzione paleogeografica. un caso particolare è quello dei contesti paleo-costieri, nei quali le forme carsiche possono servire come ulteriori elementi per il riconoscimento e la correlazione di antiche linee di riva, e fornire dati per la stima dei tassi di sollevamento. in italia sono presenti molte zone carsiche costiere, in corrispondenza di affioramenti carbonatici lungo le coste attuali o in prossimità di esse (cicogna et al., 2003). in toscana, gli esempi più interessanti si trovano in provincia di grosseto e riguardano estesi affioramenti di brecce carbonatiche, cartografate genericamente come calcare cavernoso, che presentano diversi 80 n. iandelli & l. piccini aspetti morfologici peculiari (piccini, 2001). i maggiori affioramenti si trovano al m. argentario e sui colli ad e di orbetello, per una superficie totale di circa 80 km2. la presenza di grandi cavità di sprofondamento, note localmente come “bottini”, aveva già attirato l’attenzione di mori (1931), che aveva anche osservato il fatto che queste si concentravano in corrispondenza di superfici con bassa energia del rilievo che caratterizzano le parti sommitali di alcuni rilievi calcarei. in anni relativamente recenti queste zone sono state oggetto di ricerche da parte di speleologi di firenze e grosseto (adiodati et al., 1998; cavanna, 1998). queste indagini hanno prodotto una ricca ed interessante documentazione e hanno portato alla scoperta di altre cavità, per un totale di 57 grotte conosciute. parallelamente sono state condotte ricerche lungo la costa, che hanno permesso la scoperta di numerose grotte subacquee sino alla profondità di circa 50 m (alvisi et al. 1987; alvisi & bruni, 1990; bard et al., 2001). queste scoperte, oltre ad avere evidenziato l’importanza di queste aree nel quadro dei fenomeni carsici della toscana, permettono oggi di affrontare una prima analisi del fenomeno con l’obiettivo di capire la genesi di queste forme carsiche e i rapporti con l’evoluzione paleogeografica di questa zona costiera. 2. inquadramento geografico e geologico l’area in oggetto si trova in provincia di grosseto, nell’estreme propaggini meridionali della toscana, al confine con il lazio. essa comprende una serie di rilievi continentali (poggio del leccio, colli di capalbio) e para-insulari (monte argentario, isola di giannutri), caratterizzati, con l’eccezione dell’argentario, da forme relativamente dolci (fig. 1). da un punto di vista geologico, questa zona è caratterizzata dalla presenza di più unità tettoniche di pertinenza ligure-piemontese (unità di cala grande, unità di santa fiora), subligure (unità di cala piatti) e toscana (falda toscana e unità toscane metamorfiche) (decandia & lazzarotto, 1980; bonazzi et al., 1992) (fig. 2). la falda toscana affiora come “serie ridotta”, in cui fenomeni di laminazione epicrostale, successivi all’accavallamento delle diverse unità, hanno portato all’elisione quasi completa della successione, lasciando spesso solo le formazioni evaporitiche basali (anidriti di burano) a interporsi tra basamento paleozoico e unità liguri (decandia et al. 1993). in gran parte dell’area, alle formazioni della falda toscana si accompagnano estesi affioramenti di brecce carbonatiche, cartografate come “calcare cavernoso”, la cui genesi è per molti versi ancora controversa. alle prime interpretazioni, che vedevano queste brecce come il risultato di una frammentazione autoclastica (per idratazione dei solfati) e/o tettonica delle formazioni basali della falda toscana, si sono aggiunte, con il tempo, ipotesi che vedono nel calcare cavernoso principalmente il prodotto di un rimaneggiamento in ambiente subaereo di rocce carbonatiche già fortemente cataclasate, in un quadro di esumazione tettonica e di elevata dinamica superficiale (carmignani & kligfield, 1990; pandeli & padoa, 1998). al di là delle ipotesi sull’origine di queste brecce, è importante sottolineare il fatto che esse, salvo situazioni particolari e localizzate, presentano un discreta omogeneità ed un’alta isotropia “in grande”, e quindi non sono in grado di dare luogo a forme a controllo litostrutturale, se non alla scala dei singoli affioramenti. 3. analisi dell’orografia in queste aree, e in particolare nella zona del poggio del leccio, poco a ne di orbetello, sono presenti superfici a bassa pendenza, sommitali e non, già segnalate da diversi autori (mori, 1931; pasquarè et al., 1983; zanchi & tozzi, 1987) e da questi interpretate come “antiche superfici d’erosione marina”. fig. 1 localizzazione geografica dell’area di studio e modello tridimensionale della zona di orbetello. la linea bianca delimita gli affioramenti di rocce carbonatiche; l’isola di giannutri è interamente costituita da rocce calcaree. location of study area and 3d model of orbetello area. the white line encircles the carbonate outcrops; giannutri island consists entirely of limestone. allo scopo di analizzare queste superfici da un punto di vista morfologico, è stato realizzato un modello digitale del terreno (dtm) basato su un’elaborazione, che prende il nome di tin (triangulated irregular network), che unisce tutte le quote note, distribuite nello spazio irregolarmente, attraverso segmenti. in questo modello, costruito utilizzando la cartografia numerica in scala 1:10.000 della regione toscana, con l’uso del software arcgis 8.3 di esri, la superficie topografica è approssimata da triangoli i cui vertici corrispondono ai punti quotati. dal tin è stato estrapolato un grid a celle quadrate con una risoluzione di 10 m. sul grid sono state compiute diverse analisi morfometriche ed elaborazioni statistiche allo scopo di mettere in risalto la presenza “anomala” di zone a bassa pendenza sulle sommità dei rilievi e lungo i versanti. le prime analisi, tese a descrivere l’ipsografia dell’area, hanno riguardato il calcolo della superficie delle fasce altimetriche, definite su diversi intervalli di quota, e la distribuzione altimetrica delle zone a bassa pendenza. la distribuzione altimetrica per fasce di quota su tutta l’area considerata (fig. 3a) mette in evidenza la presenza di estese superfici a quote comprese tra 75 e 100 m. al di sopra dei 100 m, l’andamento dell’istogramma ipsografico mostra un profilo regolare, tipico di un rilievo che potremmo definire “evoluto”, e non mette in evidenza la presenza di estese superfici sommitali a basso gradiente topografico. più significative risultano le analisi della distribuzione altimetrica delle superfici a bassa pendenza (fig. 3b). per la scelta del limite locale di “bassa pendenza” 81rapporti tra morfogenesi ... fig. 2 schema tettonico dell’area di orbetello e dell’isola di giannutri. tectonic sketch map of the orbetello region and giannutri island. fig. 3 a) istogramma ipsografico (fasce di quota di 10 m) dell’area studiata. b) distribuzione altimetrica delle superfici a bassa pendenza (< 14 %). a) hypsographic histogram (altitudinal ranges = 10 m) in the study area. b) altitudinal distribution of low-gradient surfaces (< 14%). 82 è stata prima effettuata un’analisi delle acclività, sulla base del dtm. da queste analisi sono state derivate, utilizzando diverse classi di pendenza, varie carte che hanno permesso di individuare in 8°, pari a circa una pendenza del 14 %, il valore che meglio discrimina le superfici a basso gradiente topografico presenti sui rilievi e in particolare su quelli a litologia calcarea (calcare cavernoso). questo tipo di analisi è stato effettuato sia su tutta l’area in esame, sia separatamente sui 3 gruppi orografici principali: monte argentario, poggio del leccio e colli di capalbio. i grafici ottenuti denotano la presenza di zone a bassa pendenza distribuite su diverse fasce di quota. sul m. argentario (fig. 4) si nota la presenza di zone pianeggianti soprattutto a quote di qualche decina di metri sul livello del mare. significativa è pure la presenza di zone di cresta arrotondate nelle parti alte del rilievo, di modesta estensione complessiva ma percentualmente rilevanti (le aree a quote comprese tra 550 e 580 m s.l.m. sono in gran parte a bassa pendenza). al riguardo occorre precisare che una parte, anche percentualmente significativa, delle zone di cresta che il grafico mostra come a “bassa pendenza” possono essere il prodotto dell’interpolazione tra curve di livello che il software opera nella costruzione del dtm. rilievi sul terreno e da foto aeree mostrano però l’effettiva presenza di zone di cresta arrotondate e a tratti pianeggianti. al poggio del leccio (fig. 5), oltre alle ampie superfici della piana costiera attuale, situate a quote comprese tra 10 e 20 m, si nota un modesto ma significativo picco a quote intorno a 250 m, la cui importanza è messa ben in risalto dal grafico che mostra il peso percentuale di queste superfici. anche qui il grafico che mostra la percentuale di superfici a bassa pendenza per ogni fascia di quota evidenzia la significativa presenza di zone a basso gradiente nelle aree sommitali, per le quali c’è il ragionevole dubbio che si tratti, in alcuni casi, di superfici fittizie create dal dtm. nella zona dei colli a nw di capalbio (fig. 6), le superfici a bassa pendenza sono localizzate soprattutto tra 70 e 100 m, senza contare l’attuale piana costiera, e corrispondono principalmente alle superfici di terrazzi fluviali del pleistocene e a superfici d’erosione che interessano diverse litologie del substrato, tra cui i conglomerati poligenici del miocene. le superfici a bassa pendenza individuate sono state oggetto d’indagini di campagna e con foto aeree, permettendo di distinguere, limitatamente a quelle d’erosione, due categorie: antiche superfici sommitali e piattaforme d’erosione marina. le prime sono arealmente significative soprattutto nell’area del poggio del leccio e sono impostate prevalentemente sul calcare cavernoso, la cui natura litologica, come già detto, permette di escludere per esse un controllo lito-strutturale per l’assenza di stratificazione. fig. 4 a) distribuzione altimetrica (10 m) delle superfici a bassa pendenza (< 14%) al monte argentario. b) rapporto percentuale tra superfici a bassa pendenza e superficie totale per fasce di quota (10 m). a) altitudinal distribution (10 m) of low-gradient surfaces (< 14%) in the monte argentario. b) percent ratio between lowgradient surface and total surface as function of 10 m altitudinal ranges. fig. 5 a) distribuzione altimetrica (10 m) delle superfici a bassa pendenza (< 14 %) al poggio del leccio. b) rapporto percentuale tra superfici a bassa pendenza e superficie totale per fasce di quota (10 m). a) altitudinal distribution (10 m) of low-gradient surfaces (< 14%) in the poggio del leccio area. b) percent ratio between low-gradient surface and total surface as function of 10 m altitudinal ranges. n. iandelli & l. piccini 83 più che di vere e proprie superfici pianeggianti si tratta di zone a basso gradiente topografico, con pendenze solitamente inferiori al 10 %, modellate in forme dolci e arrotondate e con idrografia poco accentuata. come risulta dai grafici, queste superfici si trovano localizzate prevalentemente intorno a 250 m di quota e, in misura minore intorno a 300 m s.l.m. queste zone risultano anche quelle maggiormente carsificate e ricche di cavità relitte. la presenza di estesi fenomeni carsici può avere avuto un ruolo importante, non solo nella conservazione, ma anche nel modellamento di queste superfici, contribuendo a conferire loro una bassa acclività “in grande” come risultato della coalescenza di depressioni carsiche dovute all’infiltrazione. i terrazzi marini sono invece localizzati a quote comprese tra 0 e 70 m. si tratta di lembi di superfici, di estensione solitamente ridotta, relativamente piane, in qualche caso associate a paleo linee di riva o a depositi costieri e sono attribuiti alle fasi trasgressive succedutesi durante il pleistocene mediosuperiore (mori, 1968; grauso e zarlenga, 1991; mazzanti, 1995). 4. il carsismo l’altro elemento peculiare di questa zona è la presenza di diffuse forme carsiche di superficie e di cavità sotterranee con morfologia molto particolare (mori, 1931, 1932; adiodati et al., 1998). forme carsiche di superficie sono presenti a tutte le scale. alla scala dell’affioramento si osservano le tipiche alveolature del calcare cavernoso, dovute a processi di alterazione e di dissoluzione differenziale dei clasti, accompagnati da fenomeni di disgregazione fisica che porta alla formazione di fori passanti, crepacci e rilievi ruiniformi. le forme più interessanti, come già accennato, sono però quelle a scala media e grande (sensu piccini, 1999) presenti soprattutto nelle zone superiori a bassa pendenza. rilievi sul terreno e con foto aeree hanno permesso di individuare un centinaio di doline, di diametro variabile da pochi metri sino a oltre 100. alcune grandi depressioni presenti nelle zone periferiche dei rilievi carbonatici e controllate anche da elementi strutturali, possono essere assimilate a polje marginali. é importante ricordare che nella zona di pianura sono presenti diversi laghi, e molti di più ve n'erano in passato (mori, 1932), che in gran parte possono essere interpretati come il prodotto di fenomeni di sprofondamento (sinkhole) analoghi a quello verificatosi recentemente nei pressi di roselle, poco a nord di grosseto (berti et al., 2001). al riguardo, un’ipotesi che necessiterebbe di studi più approfonditi è che molti di questi sprofondamenti si siano formati durante l’ultima fase di basso eustatico, come conseguenza dell’abbassamento della superficie piezometrica, nelle zone ove sedimenti costieri avevano coperto aree di affioramento del calcare cavernoso. molte delle doline e delle depressioni presenti nelle zone sommitali a bassa pendenza sono legate a crolli di cavità sotterranee, alcune delle quali sono ancora parzialmente accessibili. le dimensioni arrivano a superare i 20 m di diametro con profondità sino a 35 metri. le depressioni più accentuate sono note come “bottini” e presentano spesso vani laterali la cui morfologia fa pensare ad un’origine in ambiente sommerso, per la presenza di alveolature e forme di corrosione tipo spongework sulle pareti. per quanto riguarda i fenomeni carsici più propriamente sotterranei, in tutta la zona sono note 57 grotte, concentrate per lo più nell’area del poggio del leccio. le dimensioni sono in genere modeste e non sono al momento conosciuti sistemi carsici complessi. la grotta più estesa è la grotta di punta degli stretti (numero catasto: 250/gr, fig. 7), che si apre sul bordo occidentale del monte argentario, a pochi metri dalla laguna di orbetello. questa cavità è costituita da fig. 6 a) distribuzione altimetrica (10 m) delle superfici a bassa pendenza (< 14 &) nell’area dei colli di capalbio. b) rapporto percentuale tra superfici a bassa pendenza e superficie totale per fasce di quota (10 m). a) altitudinal distribution (10 m) of low-gradient surfaces (< 14%) in the colli di capalbio area. b) percent ratio between low-gradient surface and total surface as function of 10 m altitudinal ranges. fig. 7 profilo schematico della grotta di punta degli stretti (250 t/gr). sketch profile of grotta di punta degli stretti (250 t/gr). rapporti tra morfogenesi ... 84 una galleria ad andamento orizzontale con brevi ramificazioni, che si sviluppa in corrispondenza del livello del mare attuale. la grotta è prevalentemente di origine epifreatica, dovuta a processi di dissoluzione a livello della tavola d’acqua, legati a fenomeni di miscelazione tra acque d’infiltrazione e acque salmastre. nelle parti iniziali della grotta sono presenti riempimenti clastici che ricoprono antichi corpi di concrezione di età non conosciuta (segre, 1959). nella grotta sono evidenti i segni di stazionamento del livello delle acque a circa 34 m di altezza, rispetto al livello attuale, riconducibile all’alto eustatico tirreniano. altre modeste cavità a sviluppo orizzontale si trovano nelle zone di versante del poggio del leccio, intorno a quota 200 m s.l.m. la maggior parte delle grotte ha però sviluppo misto. ad un primo tratto verticale, segue un tratto orizzontale od inclinato, che corrisponde al pavimento detritico di ambienti a camera, anche molto vasti, spesso di pianta ellittica. si tratta per lo più di cavità prive di ramificazioni, di forma emisferica, comunicanti con l’esterno tramite crolli che ne hanno interessato la volta. tra queste, la più ampia e profonda è il bottino della corbacchiara (1413/gr) che si apre con un grande pozzo di 35 m, che da accesso ad una vasta camera il cui pavimento scende sino ad una profondità di 73 m (fig. 8 e 9). le numerose grotte sottomarine, note soprattutto allo scoglio dell’argentarola e a giannutri (alvisi et al. 1987; alvisi & bruni, 1990) hanno dimensioni modeste ed andamento prevalentemente orizzontale. in molti casi sono chiaramente connesse con paleofalesie ora sommerse (fig. 10). da segnalare, infine, la presenza in molte cavità di riempimenti detritici costituiti da brecce con matrice rossastra, spesso bene cementate, ricche in molti casi di resti di grossi vertebrati erbivori (cervidi, equidi) e carnivori (canidi, felidi, ursidi, …) (fig. 11) che molti autori fanno risalire al pleistocene superiore (blanc, 1955; radmilli et al., 1955; segre, 1959; azzaroli et al., 1990) 5. morfogenesi della cavità carsiche da un punto di vista morfologico è possibile distinguere due tipi principali di grotte: cavità di forma grossomodo a camera, presenti soprattutto nelle zone sommitali a bassa pendenza, e cavità ramificate a sviluppo prevalentemente orizzontale. nessuna delle grotte, anche tra le poche a sviluppo prevalentemente verticale, ha le caratteristiche di cavità di percolazione o di paleo-inghiottitoi. grandi cavità a camera, prive di estese diramazioni laterali e non inquadrabili in sistemi di drenaggio sotterraneo di acque d’infiltrazione, sono di solito attribuite a fenomeni ipercarsici (sensu forti, 1993), per lo più dovuti a miscelazione localizzata tra acque a carattere chimico diverso, legate solitamente a risalita di acque termali, fenomeni di ossido-riduzione di mineralizzazioni o intrusione di acque marine (palmer, 1991). fig. 8 rilievo topografico del bottino della corbacchiara (1413 t/gr). topographic survey of bottino della corbacchiara (1413 t/gr). fig. 9 il grande ambiente alla base del pozzo d’ingresso del bottino della corbacchiara. the big chamber at the foot of the external pit of bottino della corbacchiara. n. iandelli & l. piccini un esame, peraltro non ancora completo, delle principali cavità carsiche non ha mostrato indizi di una loro possibile origine termale, come invece avviene per altre grotte della toscana meridionale, presenti in provincia di grosseto in contesti idrotermali ancora attivi (ad esempio presso roselle e saturnia). d’altra parte, la consistenza e la diffusione delle forme carsiche permette di escludere l’azione di acque rese aggressive da fenomeni di ossido-riduzione di mineralizzazioni, in particolare solfuri, presenti in alcune aree localizzate (monte argentario, capalbio) ma non al poggio del leccio, dove invece si segnala il maggior numero di grotte. queste considerazioni, insieme a diversi altri indizi di tipo morfologico, fanno propendere per un’origine in seguito a fenomeni di miscelazione tra acque dolci ed acque salate, o comunque in un contesto costiero. nel complesso, infatti, i diversi tipi di cavità si inquadrano bene in un modello di speleogenesi costiero (fig. 12) secondo il classico schema proposto da mylroie & carew (1990; 2000). le cavità a camera si sono probabilmente formate a livello della tavola d’acqua, in un ambiente prospiciente ad un’antica l inea di costa, e in una situazione morfologica paragonabile a quella di alcune piattaforme calcaree, emerse o sommerse, attualmente presenti in aree tropicali (ad esempio florida, bahamas, yucatan). in questi contesti, risultano importanti anche i fenomeni di dissoluzione innescati da processi di degradazione di sostanza organica in condizioni anossiche, che portano alla formazione di h2s e che danno anche origine a quelle cavità note come blue hole (mylroie & carew, 2000). si tratterebbe quindi di fenomeni isolati, non connessi a veri sistemi carsici di drenaggio sotterraneo, che si sviluppano in corrispondenza di punti di maggior infiltrazione, spesso coincidenti con incroci di fratture. le cavità a sviluppo orizzontale, sovente ramificate, sono riconducibili ad almeno due generazioni. tale circostanza risulta dalla distribuzione altimetrica delle grotte ad elevato indice di orizzontalità, definito come il rapporto tra sviluppo planimetrico e sviluppo spaziale di una grotta (piccini, 1998), come mostrato nel grafico di figura 13. sopra il valore di 0,8, le grotte risultano suddivise in due gruppi ben distinti: il primo formato da 85 fig. 10 profilo batimetrico della scogliera sommersa in corrispondenza della grotta dei parapandulus, all’ isola di giannutri, (da alvisi et al., 1987, modificato). batimetric profile of submerged reef close to the grotta dei parapandulus, at giannutri island (after alvisi et al., 1987, modified). fig. 11 le brecce ossifere, deposte sopra crostoni calcitici, che riempiono relitti di cavità carsiche all’isola di giannutri, presso cala maestra, . the bones breccias, laying on a calcite flowstone, filling relict karts caves in the giannutri island, at cala maestra. fig. 12 schema di formazione di cavità carsiche in ambiente costiero (da: mylroie & carew, 2000, modificato). formation of caves in coastal environment (after: mylroie & carew, 2000, modified). rapporti tra morfogenesi ... poche cavità relitte, situate intorno a 250 m di quota, con morfologie riconducibili a fenomeni di miscelazione in ambiente freatico lungo margini costieri; il secondo ubicato a quote inferiori e quindi più recente, formato da cavità a sviluppo orizzontale, situate in prossimità dell’attuale livello del mare o anche sotto a esso, e legate a fenomeni di miscelazione, innescati dal moto delle maree, in corrispondenza della tavola d’acqua, vale a dire in corrispondenza della linea di costa. le cavità sottomarine, per le quali, a dire il vero, non si hanno descrizioni morfologiche di dettaglio, sono da mettere in relazione a fasi in cui il livello del mare era più basso dell’attuale e contengono abbondante concrezionamento formatosi in condizioni vadose. su queste concrezioni sono state seguite datazioni u/th, che hanno dato, per un campione preso in una cavità dello scoglio dell’argentarola, età comprese tra 206 e 245 ka, riferibili dunque alle fasi di basso eustatico tra gli stadi mis 7.1 e mis 6.4 (bard et al., 2002). 6. conclusioni le particolarità morfologiche dell’area, unitamente ai caratteri speleogenetici delle cavità, permettono di riconoscere alcune tappe evolutive dei fenomeni carsici che si conciliano abbastanza bene con le ricostruzioni paleogeografiche proposte per i l pliocene e i l quaternario da diversi autori (ad esempio pasquarè et al., 1983; zanchi & tozzi, 1987). l’origine delle superfici sommitali a bassa energia del rilievo, presenti ad esempio al poggio del leccio, rimane, in mancanza di indizi geologici significativi, un problema aperto. una prima ipotesi è che in occasione della trasgressione pliocenica si sia formata una vasta piattaforma d’erosione marina, che interessa l’insieme di isole di natura prevalentemente carbonatica in cui è suddivisa la porzione meridionale della dorsale mediotoscana. l’origine di questa piattaforma può essere stata favorita dalla litologia e dalla elevata permeabilità delle brecce carbonatiche. in queste condizioni si hanno, infatti, fenomeni di corrosione per miscelazione a livello della tavola d’acqua, che agiscono anche lontano dai margini costieri. questi processi danno origine a cavità ramificate che, una volta che sono intercettate dall’arretramento delle falesie, facilitano il lavoro di smantellamento del moto ondoso. non si può tuttavia escludere che la morfologia dolce delle zone sommitali, nelle zone di affioramento del calcare cavernoso, sia in parte ereditata dalla conformazione originaria del tetto di questa formazione o essere anche il prodotto di processi di modellamento in ambiente continentale durante le prime fasi di messa a nudo della successione toscana. durante il pliocene superiore, le aree carbonatiche sono smembrate dalla tettonica e sollevate in modo differenziale. alcune porzioni sono depresse sotto il livello del mare, mentre su quelle che vanno progressivamente sollevandosi si sviluppano forme carsiche legate alla presenza di una tavola d’acqua in prossimità della superficie, nonché cavità costiere ai margini. il sollevamento, che prosegue anche nel pleistocene, porta porzioni del plateau calcareo sino a 250-300 m di quota, conservati nelle superfici sommitali a bassa pendenza del poggio del leccio. nel pleistocene medio-superiore, si ha probabilmente l’esumazione e lo smantellamento delle forme carsiche più antiche in corrispondenza delle superfici sommitali e dei versanti a controllo strutturale. lungo le linee di costa si ha invece la formazione di una nuova generazione di cavità costiere, in corrispondenza della recente zona di oscillazione eustatica del livello del mare. terrazzi e cavità carsiche legate a questa fase, sono attualmente dislocati sino a 70 m di altezza sul livello del mare attuale lungo le coste meridionali del m. argentario. secondo alcuni autori ciò potrebbe essere attribuito ad un basculamento verso n pre-tirreniano che ha interessato l’argentario (grauso e zarlenga, 1991). in effetti, la morfologia del monte argentario si differenzia notevolmente da quella del poggio del leccio e dei colli di capalbio, anche in situazioni con litologia simile, indicando una maggiore attività morfodinamica legata sia alla maggiore esposizione ai processi d’erosione litorale sia, forse, ad un sollevamento più marcato e disomogeneo. dati cronologici in grado di chiarire meglio la successione temporale delle fasi principali di sviluppo dei fenomeni carsici, al momento solo abbozzate, potranno venire dallo studio e dalla datazione dei riempimenti clastici, in particolare quelli fossiliferi, e dalla datazione con metodi radiometrici delle concrezioni, previsti per il proseguimento di questo studio. ringraziamenti si ringraziano il prof. carlo bartolini e il prof. ugo sauro per gli utili suggerimenti e il lavoro di revisione del primo manoscritto. bibliografia azzaroli a., borselli v., rustioni m. (1990) nuovi ritrovamenti di fossili continentali in alcune isole 86 fig 13distribuzione altimetrica delle cavità carsiche in funzione del loro indice di orizzontalità (io). si noti come per valori superiori a 0,8, le cavità risultino divise in due famiglie ben distinte. altitudinal distribution of caves vs horizontal index (io). note that caves with indexes more than 0.8 are grouped in two well shared sets. n. iandelli & l. piccini minori dell’arcipelago toscano. atti soc. tosc. sci. nat., mem., serie a, 97, 15-30. adiodati g., fallani f., magazzini p., mori e. (1998) l’area carsica dei poggi ad est di orbetello. allegato a talp, fed. spel. tosc., 18, 16 pp. alvisi m., bruni r. (1990) le grotte sommerse dell’argentarola. speleologia, soc. spel. it., 23, 17-22. alvisi m., bruni r., casadei c., chiesi m. (1987) giannutri: gioiello del tirreno. speleo, speleo club firenze, 17, 3-12. bard e., antonioli f., silenzi s. (2002) sea-level during the penultimate interglacial period based on a submerged stalagmite from argentarola cave (italy). earth and planetary science letters, 196, 135-146. berti g., canuti p., casagli n., pranzini g., micheli l. (2001) risultati preliminari delle indagini sullo sprofondamento in loc. bottegone. in: "le voragini catastrofiche, un nuovo problema per la toscana". ed. regione toscana, 242-256. blanc a., (1955) breccia ossifera a leone delle caverne di orbetello. quaternaria, 2, 313-314. bonazzi u., fazzini p., gasperi g. (1992) note alla carta geologica del bacino del fiume albegna. boll. soc. geol. it., 11, 341-354. cavanna c., (1998) – le grotte della provincia di grosseto. soc. nat. spel. maremmana. scripta manent ed. grosseto, 174 pp. carmignani l., kligfield r., (1990) crustal extension in the northern apenni-nes: the transition from compression to extension in the alpi apuane core complex. tectonics, 9, 6, 1275-1303. cigogna f., nike bianchi c., ferrari g. & forti p. (eds.) (2003) grotte marine: cinquant'anni di ricerca in italia. min. ambiente e tutela territorio, 505 pp.. decandia a., lazzarotto a. (1980) le unità tettoniche del monte argentario (toscana meridionale). mem. soc. geol. it., 21, 385-393. decandia a., lazzarotto a., liotta d. (1993) la "serie ridotta" nel quadro della evoluzione geologica della toscana meridionale. mem. soc. geol. it., 49, 181-191. forti p. (1993) meccanismi genetici ed evolutivi delle grotte marine. speleologia, soc. spel. it., 28, 6368. grauso s., zarlenga f., (1991) il quaternario di p.ta dell’avoltore (monte argentario toscana meridionale). il quaternario, 4(2), 311-326. mazzanti r., (1983) il punto sul quaternario della fascia costiera dell’arcipelago di toscana. boll. soc. geol. it., 102, 419-556. mori a. (1931) i fenomeni carsici dell’orbetellano e del capalbiese. mem. r. soc. geogr. it., 17, 1-83. mori a. (1932) ricerche sui laghi dell’orbetellano e del capalbiese. boll. soc. geol. it., 51, 1-52. mori a. (1933) grotte nelle brecce ossifere del monte argentario. boll. soc. geol. ital., 37, 44-51. mori a. (1968) caratteri geologici e morfologici del promontorio argentario secondo le acquisizioni più recenti. boll. soc. geogr. it., serie ix, v. 10, 44-51. mylroie j.e., carew j.l. (1990) the flank margin model for dissolution cave development in carbonate platform. earth surface processes and landforms, 15, 413-424. mylroie j.e., carew j.l. (2000) speleogenesis in coastal and oceanic setting. in: klimchouk a.b., ford d.c., palmer a.n. and dreybrodt w. eds. “speleogenesis: evolution of karst acquifers”. national speleological society, 226-233. palmer a. n. (1991) origin and morphology of limestone caves. geol. soc. am. bull., 103: 1-21. pandeli e., padoa e. (1998) le rocce brecciate triassiche delle colline metallifere: calcare cavernoso e anidriti di burano. in: “il sillabario foglio di poesia, letteratura e scienza”. riv. ass. turistica “pro pomarance”. tip. grafitalia peccioli, vol. 4, 9-10. pasquarè g., chiesa s., vezzoli l. & zanchi a. (1983) evoluzione paleogeografia e strutturale di parte della toscana meridionale a partire dal miocene superiore. mem. soc. geol. it., 25, 145-157. piccini l. (1998) l’analisi morfometrica delle grotte carsiche atti 18° congr. naz. spel., chiusa val pesio, ottobre 1998. suppl. nuovi sentieri, 3 (2001), 145-149. piccini l. (1999) geomorfologia e speleogenesi carsica. quaderni didattici, società speleologica italiana, 1, 22 p.p. piccini l. (2001) l'evoluzione plio-pleistocenica del carsismo in toscana. in: "le voragini catastrofiche, un nuovo problema per la toscana". ed. regione toscana, 99-109. radmilli m.a., romagnoli l., tongiorgi e. (1955) il deposito eolico sul versante occidentale del promontorio di ansedonia e la fauna fossile della grotta rose mary. atti soc. tosc. sci. nat., ser. a, 62 (1), 73-83. segre a. (1959) giacimenti pleistocenici con fauna e industria litica a monte argentario (grosseto). rivista di scienze preistoriche, 14, f. 1-4, 1-18. zanchi a., tozzi m. (1987) evoluzione paleogeografia e strutturale recente del bacino del fiume albegna (toscana meridionale). geologica romana, 26, 305-325. 87 ms. ricevuto il 10 maggio 2006 testo definitivo ricevuto il 10 ottobre 2006 ms. received: may 10, 2006 final text received: october 10, 2006 rapporti tra morfogenesi ... animals (aurochs, horse, ibex, camel, and deer), humans (feminine silhouette, warrior-hunter, and rider), tamgas (abstract signs that recall those signs used on seals as identifiers for livestock) and boat figures. each chronological phase has its own distinct style and subject matter that, in some cases, have provided interesting connections with other contexts, offering a preferential view onto the possible cultural geographies of the past, especially on those dynamics occurring between asia and europe. available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 38 (1), 2025, 45-62 https://doi.org/10.26382/amq.2025.03 1. introduction the long chronology, from the upper palaeolithic to historical times, together with the high quality and the excellent preservation of thousands of petroglyphs on more than 1,000 boulders or rock walls make gobustan (qobustan in azerbaijanian language) one of the richest and most interesting open-air rock art sites in eurasia (sigari, 2020). the main themes of this rock art heritage include rock art relationships between central asia and europe: the role of gobustan (azerbaijan) dario sigari1,2, marcos garcía-diez3, sevinc shirinli4, rәhman abdullayev5, susana alonso6, bàrbara mas7,8, daniele gianolla9, nurane hasanova4, darío herranz-rodrigo10, blanca ochoa3, guillermo bustos-pérez11, manuel vaquero6, günay verdiyeva4, andrea zerboni12 1dipartimento di beni culturali e ambientali, università degli studi di milano, milano, italy. 2dipartimento di studi umanistici, università degli studi di ferrara, ferrara italy. 3facultad de geografía e historia, universidad complutense de madrid, madrid, spain. 4gobustan national historical artistic preserve, gobustan, azerbaijan. 5minnesota historical society, minnesota, usa. 6departament d'història i història de l'art, universitat rovira i virgili de tarragona, tarragona, spain. 7université côte d'azur, cnrs, cepam, nice, france. 8serp, departament d’història i arqueologia, universitat de barcelona, barcelona, spain. 9società romana di scienze naturali, roma, italy. 10departamento de prehistoria y arqueología, universidad de granada, granada, spain. 11department of human origins, max planck institute for evolutionary anthropology, leipzig, germany. 12dipartimento di scienze della terra “ardito desio”, università degli studi di milano, milano, italy. corresponding authors: dario sigari <dario.sigari@unimi.it>; marcos garcía-diez <diez.garcia.marcos@gmail.com>; sevinc shirinli <sevincshirinli19@gmail.com> abstract: within a continuously changing scenario of knowledge about prehistoric and late prehistoric art, the contact area between asia and europe is crucial in understanding the development of the graphic symbolism of ancient cultures. consequently, the gobustan region in azerbaijan, which hosts numerous open-air rock art sites, is a key to interpreting the emergence of symbolism, its dispersal, and the social dynamics beyond it. the azerbaijan region preserves one of the richest open-air rock art sites in eurasia. it is at the easternmost end of the greater caucasus range, along the western bank of the caspian sea, whose quaternary level changes profoundly shaped local landforms, and heavily conditioned human settlement patterns. its unique geostrategic position nurtured a cultural crossroads between europe, central asia, and the near east, influencing the region’s artistic traditions. designated as a unesco world heritage site (2007), gobustan engravings possess a universal and exceptional value for their quality, quantity, and density (more than 7,000 petroglyphs on over 1,000 rocks) and preservation, in addition to their chronological (from the upper palaeolithic to historical times), thematic and stylistic variety. among the symbols, the main themes are animals (aurochs, horse, ibex, camel, and deer), humans (feminine silhouette, warrior-hunter, rider), tamgas and boats. engravings are carved in limestone boulders, shaping the figures with a thick and deep main outline, often overlapping previous figures, thus forming rich palimpsests. the long use of the same sites, rocks and symbols prompt a reflection on the meaning of the places, which was probably passed down from generation to generation, increasing the number of decorating motifs, reusing, and/or modifying previous graphic units. several engraved rocks are found inside shelters with occupation layers or burials. they help to understand the use, the social function of the rock art, through the analysis of the archaeological remains and the functional complementarity of the sites. major shifts in the main represented subjects, and in their styles occurred over the long occupation of the site: the palaeolithic art shows ties with the western european tradition, while the post-palaeolithic engravings suggest links with the middle east and arabian peninsula. therefore, gobustan rock art invites to investigate potential changes in the relationship between socioeconomic organisation and symbolic heritage. in this way, the gobustan engravings become a powerful legacy of lost cultures and demonstrates the symbolic and cognitive complexity of ancient human groups, suggesting cultural and economic changes, dispersals, and connections. as such, the study of the archaeological record of gobustan, and its rock art in particular, provides crucial information to the main scientific debate around: 1) the way the stylistic, thematic and technological development of prehistoric art took place; 2) the relations with other european and asian rock art contexts in terms of differences and similarities; 3) the cultural, social or symbolic contexts into which the rock art was produced. this paper presents the gobustan rock art context and the new international research project. keywords: rock art; caucasus; world heritage site; prehistoric archaeology. mailto:dario.sigari@unimi.it mailto:diez.garcia.marcos@gmail.com mailto:sevincshirinli19@gmail.com a new archaeological research project, funded by fundación palarq-fundación atapuerca and the ministry of the foreign affairs of the italian republic, began in 2019 (garcía-diez et al., 2020; sigari et al., 2020). this paper provides a first introduction to the site, together with a general literature review, presenting the new project and its main objectives. 2. backgrounds 2.1. location gobustan is a semiarid region of azerbaijan, on the northern edge of the shirvan steppe subdesert plain, about 60 km south of the capital city, baku. it is at the easternmost appendix of the greater caucasus range, on the western bank of the caspian sea, and represents an important landbridge between europe and asia (fig. 1). in this setting, the national historical-artistic preserve of gobustan includes five main rock art clusters: böyükdaş (188 m above sea level-asl), kiçikdaş (170 m asl), jingirdağ (198 m asl)-yazılitepe (47 m asl), şongardag (200 m asl), and şikhgaya (202 m asl). outside the boundaries of the reserve, a further three clusters were discovered: daşlidag, şikhov beach, and sona gaya (86 m asl) respectively found in 2002, 1989 and 2017 (abdullayev & shirinli, 2020; shirinli & abdullayev, 2021). in 2007, at the xxxi session of unesco in christchurch, new zealand, the gobustan rock art cultural landscape complex was inscribed on the world heritage list (sigari et al., 2019). gobustan, which means the “land of dry riverbed”, is characterised by a landscape with flat top rock outcrops within a semiarid environment, dotted by cold mud volcanos and flat-top hills (fig. 2). the vegetation 46 sigari d. et al. fig. 1 location of gobustan in: (a) the euromediterranean area (from googleearth, editing: d. sigari), and (b) azerbaijan (image: d. sigari). (c) the gobustan national reserve, from north to south jingirdağ-yazılitepe, kәniza volcano, böyükdaş and kiçikdaş. the numbers indicate the shelters gaya arasi 1 (1), firuz 2 (2), ana zaga (3) and maral (4) (from: sigari et al., 2019). the middle ages (rustamov, 1994; rustamov & muradova, 2008; shirinli & abdullayev, 2021). muradova and rustamov recorded nearly 400 new engraved stones, landscape of gobustan reflects extreme environmental conditions typical of desert and semidesert ecosystems, with water scarcity, high soil salinity, and poorly developed substrates. the presence of plant communities dominated by artemisia lerchiana, bothriochloa ischaemum, and halophytes such as halocnemum strobilaceum and salsola spp. indicates vegetation highly adapted to aridity and edaphic stress, forming a discontinuous but functional steppe environment for species such as saiga tatarica (dieterich & askerov, 2024). its geology comprises a thick limestone sedimentary rock containing in its matrix numerous fragments of bivalve shells attributable to the genus didacna sp. (fig. 3), an endemic taxon that survived till recent times, as recognised within the archaeological layers together with other endemic taxa of marine molluscs (such as the bivalve dreissena cf. grimmi and monodacna cf. caspia and the gastropods turricaspia meneghiniana, t. lyrata and laevicaspia caspia) (van de velde et al., 2019) as a consequence of the long submersion of the region by the caspian sea during the pleistocene (sigari, 2020). sporadic occurrence of landsnail remains (particularly the dune species xerolenta obvia) points to a proximity to the coast of an open, dry environment (welter-schultes 2012). following the maximum stage of the early khvalynian sea transgression (up to +50 m above sea level-asl), another two transgression movements occurred during a period of deglaciation, approximately around 16,000 and 14,000 years ago, increasing sea level up to +35 and +22 metres asl (arslanov et al., 2016; dolukhanov et al., 2010). at that time gobustan must have been under water and the two hills böyükdaş and kiçikdaş would have emerged as two islands. later on, between 14,000 and 12,000 years ago the caspian sea level increased from the present level (-28 metres under sea level-usl) again twice up to 0 and -12 metres; the former probably corresponding to an allerød warming phase, and the latter to the warming at the end of the younger dryas (arslanov et al., 2016; dolukhanov et al., 2010; mamedov, 1997; yanina, 2012). the terraced profile of the upland areas of böyükdaş and kiçikdaş is therefore clear evidence of ancient coastlines where the first human groups landed and settled. 2.2. history of research the discovery of gobustan rock art dates to may 1939. archaeologist iskhag jafarzade then began intensive fieldwork in 1939. however, due to events in world war ii, systematic research did not start until 1947 and continued under that scholar until 1965. during this work, most of the engravings were documented, and over 3,500 petroglyphs including anthropic cupmarks and holes, on more than 750 rocks, were catalogued and studied (jafarzade, 1973). following jafarzade’s work, archaeologists rustamov and muradova continued archaeological research in gobustan, unearthing a long chronological multilayered stratigraphy from the upper palaeolithic to 47 rock art relationships between central asia and europe: the role of gobustan (azerbaijan). fig. 2 (a) cold mud volcanos in the area of kiçikdaş (photo: d. sigari); (b) the böyükdaş flat-topped hill (pink arrow) and kәniza volcano on the back (yellow arrow) (photo: d. sigari). fig. 3 fossiliferous limestone with external and internal molds and seashell fossils of didacna sp. (photo: d. sigari). increasing the number of rock art sites to more than 6,000 engravings on 1,000 rocks (rustamov & muradova, 2008). at the beginning of the new millennium new studies have been carried out by farajova, (2009, 2018), sigari (2009a, 2009b, 2013, 2016, 2017), abdullayev and shirinli (abdullayev & shirinli, 2020; shirinli & abdullayev, 2021), leading to the discovery of new petroglyphs, and increasing the number of the known engravings to more than 7,000. 3. archaeology of gobustan and chronology of its occupation according to the literature, the archaeological evidences of long term occupation are abundant: forty kurgans (burial mounds built over grave), a multiple burial (ten adults and one child) in firuz (fig. 4), a possible sanctuary in yazılitepe, and bronze age settlements have been documented, together with around 105,000 archaeological finds, including flints, pebbles and tools, ochre fragments, arrow heads and such other weapons as axes, clay vessels and bones (farajova, 2018; rustamov, 2006). however, if we assume that archaeology is a time science, then the available chronometric data to establish the different occupation stages in gobustan are very limited (farajova, 2012, 2018). the first dated sample came from ana zaga (the mother cave, in azerbaijanian language) at a depth of 1.85 m and yielded an age of 8,996 ±33 bp (farajova, 2012: 937). a few more samples from gaya arasi 1, firuz 2, ana zaga and maral (fig. 1c) were later published by farajova (2018). unfortunately, their entire archaeological context has not yet been cleared or published, and therefore the real link with the parietal engravings is missing. only the height of the engravings and the depth of the dated sample are known, which makes the dating series uncertain, at least as a way to propose an interpretation of the rock art chronology. thus, any chronological proposal must currently be based on the typological analysis of the material culture. according to rustamov (2006), the first occupation phase was between 20,000-15,000 years ago. the fisher-hunter-gatherer human groups settled gobustan until around 9,000 years ago. in this period, societies mainly hunted gazelles and mules. by analysing the findings, scholars have divided this long-time frame into two main moments, the first one fig. 4 the firuz site in kiçikdaş. the rock under the sheltered part is completely engraved with boat, anthropomorph and zoomorph figures (photo: d. sigari). >>>> fig. 5 the southern side of rock no. 29, where it is possible to see hunters-warriors of different size and a boat figure with a solar symbol on its praw. part of the panel (see the remarked human figure in yellow) is covered by a slab (its edge is marked in white) that fell from the top of the mountain in ancient time suggesting a catastrophic event that happened in the past and led to the displacement of several rocks (photo: d. sigari). 48 sigari d. et al. rock art production in böyükdaş and kiçikdaş, as well as the expansion of rock art creation to other regions, such as jingirdağ and the abşeron peninsula. archaeological excavations carried out by rustamov and muradova between 1972 and 1977 in jingirdağ led to the identification of a three-room building, where glazed and unglazed ceramic materials, bone remains, stone objects, a gold ring with turquoise, and other artefacts were found. the ceramic finds perfectly fit within the general pottery record recovered at other medieval sites in azerbaijan, thus providing a valid chronological reference. the same is true for the glazed ceramic that dates to the 10th-13th centuries ad. a second room was brought to light in yazılitepe. here the traces of a hearth and pottery confirm that there was a dynamic society in gobustan during the middle ages (muradova & rustamov, 1993: 97-98). more middle age materials come from böyükdaş where archaeological excavations were carried out near rocks no. 6, 7, 8 and in the ana-zaga shelter. here, both antique and early medieval pottery was recorded (rustamov & muradova, 1980). lastly, important information about the way of life of the local communities during the middle ages was determined in daşlidag in kiçikdaş, where pottery and architectonic remains confirm the predominance of transhumant pastoral and agricultural societies (rustamov & muradova, 2008). the continuous occupation of the region, from the upper palaeolithic to the middle ages, also involved the production of rock art (rustamov, 2006). linked to upper palaeolithic societies, and the recent one to mesolithic cultures. palaeoenvironmental analyses were performed for the most ancient phases and showed how during the first settlement of gobustan the environment was characterised by a drought-resistant open woodland with pistachio trees, hawthorn, willow pear, juniper and pomegranate (vereshagin, 1981; farajova, 2009). in the late pleistocene, the gobustan landscape must have resembled a tugay forest, with oak and pine trees (farajova, 2009; rustamov, 2006). based on the archaeological evidence, despite the discovery of a pre-pottery neolithic burial in kaniza shelter and some artefacts, the neolithic is underrepresented. the explanation may be found in a natural event that occurred in gobustan in the early years of the neolithic, that can be recognised in the numerous displaced rocks, and that led to a temporary abandonment of the region until the end of the calcolithic-beginning of the early bronze age (rustamov, 2006; sigari, 2009a; sigari et al., 2019) (fig. 5). a later human presence in the region is confirmed during the bronze age, when it is possible to recognise strong influence by other caucasian cultures, e.g., the kura-arax, maykop, and khojaly-gadabay (muradova, 2011). during the bronze age, rock shelters ana zaga, çardag zaga, çapmali, and firuz-1, and fortified settlements daire and böyükdaş were densely inhabited by transhumant pastoral groups (muradova, 2011; crist & abdullayev, 2024). the heightened occupancy of old shelters and settlements coincided with an increase in fig. 6 part of the big northern panel of the rock no. 29 of böyükdaş with its rich palimpsest that can be the key to understand the different figurative periods (photo: d. sigari). 49 rock art relationships between central asia and europe: the role of gobustan (azerbaijan). 4. the rock art ensemble and its chronology the rich rock art heritage can be classified into eleven main thematic groups: aurochs, horse, boats, feminine silhouette, warrior-hunter, ibex, camel, tamgas, deer, rider and inscription. each chronological phase has its own distinct style and subject matter. consequently, based on the analysis of the variability of the themes, it has been possible to suggest chronological interpretations. different scholars have proposed relative chronologies based on petroglyph styles. first, jafarzade recognised six styles grouped into two phases: the first three belong to the most ancient periods (jafarzade, 1973). when anati reviewed jafarzade's chronology in 2001, he suggested subdividing the first two cultural horizons described by jafarzade (1973) into six phases in the following order: i/a, b, c; ii/a; i/d; ii/b; i/e; ii/c (anati, 2001). however, anati in his tracing of rock no. 29 marks a boat, attributed to phase i/e, under an aurochs of phase ii/b (anati, 2001: 30), demonstrating how his chronological scheme is objectionable (fig. 6). elaborating on jafarzade's chronology, rustamov proposed a stylistic evolution, but for each subject and only for three main categories: anthropomorphs, zoomorphs and boats. the original factor in rustamov’s work is the emphasis given to the anthropomorphic figures which seem to have been first engraved. the male figures reveal a different sequence based on their sizes, from the smallest to the biggest. the same stylistic evolution appears in the different shapes of boats whereas, among the zoomorphs, the oldest would be the most naturalistic figures, not the smallest ones (rustamov, 2006). in the first decade of the new millennium, farajova developed a new stylistic and more detailed chronology consisting of six phases each subdivided into different styles (farajova, 2009, 2018). the first phase has been subdivided into four styles and would correspond to the whole upper palaeolithic and mesolithic. the second and third phases belong to neolithic, while the fourth and the fifth phases, respectively to the bronze age and the iron age. the sixth phase encompasses the late periods (farajova, 2009, 2018; shirinli & abdullayev, 2021). 5. the sea in the rocks the caspian sea not only shaped the landscape of gobustan, but also profoundly influenced cultures and economies of the ancient settlers in the region. witnessing this relationship, together with the archaeological finds discovered in excavations, such as the tools for weaving fishing nets (rustamov, 2006), are the fish (fig. 7) and boat figures engraved in the rocks (farajova, 2009; sigari, 2017). moreover, a series of pierced rocks suggests they were used to dock the boats when the sea reached those terraces. these links with the water resource formed the core of a recent study that looked at the relationships between rock art themes and landscape, or rather “seascape” (sigari, 2017), to approach an understanding of the chronology of gobustan rock art. it focused on the boat figures which had been engraved over a long time, changing style, possibly according to new ideologies (sigari, 2017, 2020) (fig. 8). through the analysis of the changes in styles, altitudes and positioning of boat figures, a relative chronology revealed different use of spaces, from the top of the hills down to the lower terraces, fig. 7 one of the fish figures of the rock no. 104 of böyükdaş (photo: d. sigari). in the small picture on the right, the same fish figure is highlighted. 50 sigari d. et al. 14,000 years ago, when the caspian sea level was higher than today (badyukova, 2021; sigari, 2017, 2020). then, between 14,000 and 12,000 years ago, the later khvalynian stages occurred, and the caspian sea on what must have been palaeo-beaches. the first boat images, which are very simple in their shape even though they may vary in their size, are found on the upper terraces of both böyükdaş and kiçikdaş and would date to a period of deglaciation, between 16,000 and fig. 8 detail of the western panel of rock no. 19 in kiçikdaş, with a key series of engraved boat figures (photo: d. sigari). fig. 9 a second sector of the big northern panel of the rock no. 29 of böyükdaş. the simple-shape long boat is highlighted (photo: b. ochoa). 51 rock art relationships between central asia and europe: the role of gobustan (azerbaijan). 6. scene compositions the relationship among different figurative themes is a recurrent topic in the gobustan rock art. therefore, after briefly introducing the graphic compositions in which the boat figures appear, we can recognise how all the other different graphic units are associated: how they may be found standing alone, or in relationship with other figures. these relationship typologies are differently expressed in terms of juxtaposition or superimposition. for the juxtapositions we recognise: • figures facing one another e.g., the aurochs confronted on rocks no. 46b, 49, or the caprids on rock no. 42 in böyükdaş, and rock no. 54 in jingirdağ-yazılitepe (fig. 11); • figures in line e.g., the two boats on rock no. 8 (fig:10), the bovids on rock no. 42, or the anthropomorphs on rock no. 67 in böyükdaş (fig. 12a); • herds: rock no. 46 in böyükdaş (fig. 12b); • hunting scenes e.g., rock no. 45 in böyükdaş (fig. 12c). this kind of figurative association can express contemporaneity and possibly a narrative involving the represented subjects. in contrast, superimpositions are harder to interpret since they may be the result of diachronicity in a figurative palimpsest and this may respond to different reasons: e.g., refreshing, narrative, erasing, reusing. an interesting kind of composition is the bovidhorse pairing that is differently expressed by juxtaposing figures in line, for instance on the western side of rock no. 31 in böyükdaş, or by placing an equid inside a bovid, e.g., an unnumbered rock behind ana zaga in böyükdaş; or by superimposing the horse on the aurolevel increased from its current level, which is 28 metres usl, up to 0 and 12 metres usl (dolukhanov et al., 2010). to this period, or to a later one, the boat figures engraved in the foothills of böyükdaş and kiçikdaş can be dated. from here the boat style with the sun-symbol on the prow and the “x”-shaped crew would spread up to the upper terraces (sigari, 2017, 2020) (fig. 10) and might last for centuries, until a significant cultural change. boat figures were displayed differently in the panels: alone, superimposed by other themes, associated in pairs or in groups. at first sight, it seems that the long boats with a simple shape, for instance the one on the northern side of rock no. 29 in böyükdaş (fig. 9), are alone and correspond to the earliest artistic phases. in contrast, in the most recent phase, when the prows are curved and the solar symbol becomes a recurrent feature decorating the ships, boats are represented in pairs or groups, e.g., rock no. 8 in böyükdaş (fig. 10) or rock no. 19 in kiçikdaş (sigari, 2017). moreover, they are juxtaposed or underlie anthropomorphic figures, mainly female silhouettes, and zoomorphs, especially bovids (sigari, 2017). the boat theme is peculiar to gobustan and is possibly among the oldest evidence of sailing. however, some connections have already been proposed with figures in the scandinavian peninsula and recently a new relationship has been suggested with a painted motif found in the late upper palaeolithic layers of romanelli cave in southern italy (sigari, 2020). the diffusion of this symbol, despite different chronologies, means we should look further into its evolution, importance for past cultures, and the human dynamics behind its representation. fig. 10 rock no. 8 on the lower terrace of böyükdaş and its coupled boats with the “x-shaped” crew (photo: d. sigari). 52 sigari d. et al. mediterranean area in the late pleistocene (delporte, 1990; leroi-gourhan, 1992; sauvet & wlodarczyk, 2000). moreover, from a stylistic point of view some comparisons can be established as well, especially for the bovids, as expressed by several researchers. therefore, in brief, it seems that during the late pleistocene we can recognise elements, in terms of themes, styles, and compositions, in common with the artistic tradition of societies that lived and spread around the mediterrachs like on rock no. 49 in böyükdaş (fig. 11a). what emerges in the three cases is a strong link between the two animals that may recall a sort of structured cosmogony of opposed or complementary elements that undoubtedly needs to be investigated further. bovids and equids are certainly among the most represented themes in palaeolithic art in western europe and such a recurrent association invites us to investigate the spread and diffusion of these subjects in the eurofig. 11 (a) facing bovids, with a horse overlapping one of the two aurochs, on rock no. 49 in böyükdaş; (b) facing goats on rock no. 42 in böyükdaş; (c) facing goat figures on rock no. 54 in jingirdağ mountain and behind is the sheltered site composed by rocks no. 12 and 9 (photos: d. sigari). 53 rock art relationships between central asia and europe: the role of gobustan (azerbaijan). • the so-called dancers and jumpers (fig. 12a), • human figures with raised arms (fig.s. 14b). anthropomorphs usually change from the most stylized to the most naturalistic figures. these changes occur according to different chronological phases. rustamov (2006) emphasised the anthropomorphic figures which seem to have been the first engraved. they reveal male figures belonging to a sequence based on their size, from the smallest to the largest (sigari et al., 2019). moreover, the first three groups are usually associated with the most ancient phases, while the fourth is recurrent during late prehistory e.g., rock no. 25 in jingirdağ-yazılitepe (jafarzade, 1973), or rocks no. 15, 24, 29 in böyükdaş (jafarzade, 1973; sigari, 2009b). undoubtedly, the most fascinating theme is linked to the female silhouettes, which have appeared in gobustan rock art since the upper palaeolithic, as the series of this representation in the lowermost part of the nean basin. finally, any potential narrative seems also to be reflected in the association of bovid and anthropomorphic figures surrounding the animal, as in the big southern panel of rock no. 30 (fig. 13) or unnumbered rock behind ana zaga in böyükdaş. 7. anthropomorphic figures together with zoomorphic figures, which were recently discussed in a complete and detailed paper by shirinli and abdullayev (2021), anthropomorphic figures are important among the different figurative categories of gobustan. four main groups of anthropomorphic petroglyphs can be defined: • female silhouettes (fig. 14a), • hunter-warriors (fig.s. 5, 12c), fig. 12 (a) the anthropomorphic figures of rock no. 67 of böyükdaş. they are displayed in two main rows, framing them into the panel. some of the graphic units have a headgear; (b) a series of horse figures, all oriented to the west, towards the sheltered area. böyükdaş, rock no. 46; (c) a hunting scene to aurochs on rock no. 45 in böyükdaş (photos: d. sigari). 54 sigari d. et al. engraving techniques differ from one figure to another. this high concentration of multiple styles is unlike the situation on rock no. 78 in böyükdaş, with the so-called “seven beauties” (fig. 16). indeed, these six (despite the given name) female figures are homogeneous in their style (all represented in frontal view, with decorated bodies and a pole on their breast) and overlap a bovid figure. the same graphic composition is seen on a rock near rock no. 78, apparently closing that hidden place dominated by those female silhouettes, thus suggesting a possible social meaning of the site, with exclusive accessibility. northern side of rock no 29 in böyükdaş seems to confirm (fig. 15). the subject of female silhouettes varies considerably in terms of style, size, location, and association with other figurative themes. this may reflect not only different chronologies, but even different cultural and social reasons e.g., the accessibility of a site determining if it was a public or not (sigari, 2016). thus, on rock no. 29 in böyükdaş we find different feminine representations that are clearly visible. some of them are small sized, while others can be c. 1.5 m high. some are displayed in front view, others in profile. some are squared, contrasting with the more sinuous ones. even the fig. 13 a detail of the southern side of rock no.30 in böyükdaş where it is possible to see a bovid figure surrounded by anthropomorphs (photo: d. sigari). fig. 14 (a) female silhouette in profile with the decorated body on rock no. 2 in böyükdaş, lower terrace; (b) praying anthropomorphs on rock no. 24 in böyükdaş (photos: d. sigari). 55 rock art relationships between central asia and europe: the role of gobustan (azerbaijan). fig. 15 the female silhouettes of rock no. 29. they are displayed in row and are partially covered by the ground, suggesting they can be among the earliest figures of the panel (photo: d. sigari). fig. 16 the “seven beauties” are engraved in a hidden place, where the accessibility is reduced to very few people suggesting a private use of the space. the figures are showed in front view with the decorated body and overlap a bovid (photo: d. sigari). 56 sigari d. et al. rences in the way this animal was portrayed. deer images in gobustan can be divided into two groups according to the techniques used: linear images and images with outline. deer are recorded as single, isolated images, in groups or herds, and in hunting scenes. deer antlers are shown as being very large, forming a primary focus; their tines are very thin, and some have backward tails. deer images are usually depicted in motion, sometimes turning the head backward. the deer body on stone number 9 in jingirdağ was depicted close to natural size, despite the exaggerated antlers (fig. 19b). jafarzade attributed the oldest deer images to the 3rd millennium bc (jafarzade, 1973). the deer-hunting scenes found in the jingirdağ-yazılitepe area would belong to a second stage, between the 2nd and 1st millennia bc (rustamov, 1994: 73-74). besides the images in rock art, deer were frequently depicted on ceramics and metal objects in the bronze age (abdullayev, 2016). some naturalistic deer figures may recall other representations in central asia, e.g., siberia and mongolia (francfort et al., 1990; kubarev, 2010; molodin & cheremissin, 1999), where this animal becomes the main motif and displays stylistic similarities, suggesting shared symbolism over wide territories. 10. sacred spaces gobustan rock art seems to be strictly linked to the daily life and is usually located in places where products of everyday life have been unearthed e.g., pottery, lithic and bone tools, and hearths. however, the firuz site indicates how rock art was associated with afterlife rituals as well, as attested by the burials discovered there (rustamov, 2006; sigari, 2017). this link is evident from the most ancient phases and possibly lasted for millennia. it is particularly common in the bronze age, when more structured spaces existed, like the yazılitepe (fig. 11c). 11. historical inscriptions another interesting theme in gobustan rock art consists of inscriptions. indeed, thanks to them it was possible to understand the importance of the region during millennia when it was a landbridge between europe and asia and a place of exchanges and meetings among people. thus, here we find the roman inscription furthest from rome. at the foot of the böyükdaş mountain, there is an epigraph engraved by a centurion of the legio xii fulminata of the roman army. the inscription testifies the passage of the romans in gobustan during domitian’s reign (ad 81-96) (sigari et al., 2019) (fig. 20a). in jingirdağ "imad shaki came, prayed, left" was written on rock no. 91 close to where the remains of a building were found. according to jafarzade (1973), this epigraphic sample dates to the 13th or 14th centuries ad, so it would be the same age as the proximate building, suggesting that the place was dedicated to worshipping activities (fig. 20b). more inscriptions have been found, and some date to even more recent times. these inscriptions are written in cyrillic alphabet and mainly report personal names. 8. the time of the goats a significant change in the graphic repertoire of the gobustan rock art can be noticed during the bronze age. in this period the most frequent themes are bezoar ibex (capra aegagrus), deer (cervus elaphus) and anthropomorphs (shirinli & abdullayev, 2021). the main petroglyph clusters belonging to this period are in jingirdağ-yazılitepe and böyükdaş. especially in böyükdaş, the ibex are ideal chronological markers since they are not associated with the most ancient figures and, in some cases, overlap previous carvings (abdullayev & shirinli, 2020; sigari et al., 2019). moreover, this subject was found on 30 rocks out of 34, which were covered by layers dated to the bronze age, thus confirming the chronological reference, between the 4th and 2nd millennia bc (abdullayev, 2016; muradova, 2003) (fig. 17a). the large number of ibex figures naturally attracted the attention of the researchers who tried to address this topic in terms of both the chronology and its meaning (abdullayev, 2016; farajova, 2009; jafarzade, 1973; muradova, 2003; rustamov, 1994). a first classification of this theme distinguishes between the more realistic figures (some of them in their natural size too) which are proper of the bronze age, and the more schematic figures that belong to more recent periods; for instance, jingirdağ-yazılitepe rock no. 59 (fig. 18) (abdullayev, 2016; jafarzade, 1973). the explosion of this subject in the rock art of gobustan seems to reflect a significant change in the cultural connections, which are no longer addressed towards the mediterranean and western europe as in the case of palaeolithic imagery (sigari, 2013; sigari et al., 2019), but are closer and involve, from a thematic point of view, western and central asia; e.g., iran (karimi et al., 2020), oman (fossati, 2018) and the altai region (shirinli & abdullayev, 2021) and mesopotamia (crist & abdullayev, 2024). according to muradova (2003), the change in the choice of theme reflects an alteration in the economic life of people causing a modification in religious beliefs too. thus, ibex increased in importance for the gobustan inhabitants, they become a worshipped element (muradova, 2003: 48). finally, farajova in her book “rock art of azerbaijan” proposed that ibex images would be a symbol of sun and fertility, with the large, curved horns that would be linked to the sun (farajova, 2009: 173) (fig. 17b). according to shirinli and abdullayev (2021) ibex figures are present in almost all periods from the early bronze age to the historical period. they were rarely represented during the palaeolithic. however, with the development of seasonal pastoralism, this animal soon became a main player in the agricultural economy, on the farm and in people’s worldview, thus affecting religious ideas. 9. the last deer the cervid theme is a minor topic in discussions on gobustan rock art. nevertheless, deer petroglyphs appear in gobustan, absheron, kalbajar and gemigaya rock art repertories, at least in azerbaijan. thus, for the deer, we can recognise three main clusters in jingirdağ-yazılitepe, kiçikdaş and böyükdaş (fig. 19a). the three concentrations show some diffe 57 rock art relationships between central asia and europe: the role of gobustan (azerbaijan). fig. 17 (a) jingirdağ-yazılitepe, goat figures and a horse rider on rock no. 47; (b) the dominating rock no. 1 in jingirdağ-yazılitepe, with its series of goat figures. the human figure with the raised arms, apparently holds a goat, however it was probably reused being under the zoomorph and so representing an older stage (photos: d. sigari). 58 sigari d. et al. such a huge concentration of rock art in gobustan, in relation to the occupation contexts? • what is the relationship between symbolic space and domestic space? • was the palaeolithic graphic tradition produced within a local tradition? or was it part of wider phenomenon and therefore should be studied within a network of graphic traditions? the research focuses on the ana zaga site in böyükdaş. after the forced stop because of the sars12. a new research project a new interdisciplinary research project began in 2019 with the objective of answering some crucial questions: • when did the prehistoric art of western asia first appear? • how did the palaeolithic rock art develop in stylistic, thematic, technical and spatial organisation aspects? • what is the cultural, social or symbolic reason behind fig. 18 tracing o f the rock no. 59 of jingirdağ-yazılitepe (from: abdullayev & shirinli, 2020) with the goat figures in both naturalistic style (bronze age) and schematic (probably historical times) (photos: k. abbasov & r. abdullayev). fig. 19 (a) a deer figure from böyükdaş rock no. 22 with a more schematic style; (b) the big naturalistic deer from jingirdağ-yazılitepe. it is located on the top of stone no. 9 (photo: d. sigari). 59 rock art relationships between central asia and europe: the role of gobustan (azerbaijan). types of evidence will provide solid references to answer the main questions of the research project, fill those blank pages of the new chapter of the project itself, remark the importance of carrying out interdisciplinary works in rock art contexts, highlight the value of the international cooperation, and establish a methodological approach to such a site typology. acknowledgments the authors wish to thank the gobustan national historical artistic preserve director, mr. vugar isayev; the workers at the gobustan museum for their help; and mr. fikrәt abdullayev for his support. we are greatful to peter smith for the written english review. the research is funded by the fundación palarqfundación atapuerca, and by the ministero degli affari esteri e della cooperazione internazionale della repubblica italiana (n. 954-2021, n. 1234-2022, n. 1501-2023, n. 2969-2024). bo is a researcher under the juan de la ciervaincorporation program (jc2020-044629-i), funded by the spanish ministerio de ciencia e innovación (mcin/ aei/10.13039/501100011033) and the european union nextgenerationeu/prtr. references abdullayev r. (2016) bronze age rock art of gobustan. arkeos proceedings of the xix international rock art conference ifrao 2015 (cáceres, spain, 31 august 4 september 2015), 37, 16931703. abdullayev r., shirinli s. (2020) qobustan. cingirdağyazılıtəpə və sona qaya petroqliflerinin korpusu. ideal-print, baku, pp 520. anati e. (2001) gobustan. azerbaijan. edizioni del centro, capo di ponte, pp. 95. arslanov kh. a., yanina t.a., chepalyga a.l., svitoch a. a., makshaev r.r., maksimov f.e., chernov s.b., tertychniy n.i., starikova a.a. (2016) on the age of the khvalynian deposits of the caspian sea coasts according to 14c and 230th/234u methods. quaternary international, 409, 81-87. doi: 10.1016/j.quaint.2015.05.067 badyukova e.n. (2021) caspian sea level fluctuations in the neopleistocene (was there an atelian regression?). oceanology, 61(2), 283-291. cov-2 pandemic outbreak, five fieldwork sessions have already taken place between november 2021 and august 2024, involving both an archaeological excavation and rock art recording. their objective was to study some specific areas to then lay the foundations for the next archaeological activities, which aim to systematically document the artistic production and the traces of the daily life of the people who used this shelter. 12.1. the ana zaga shelter the selected shelter is located on the upper terrace of böyükdaş and is made of some displaced limestone boulders: rocks 29, 30, 31. these blocs were engraved with hundreds of figures (anthropomorphic, zoomorphic, boats above all), whose style points towards a long chronology of use of the site. moreover, the dense palimpsest characterised by several overlapping figures support the long reuse of the rock surfaces to make rock art, as the two main rocks forming the shelter reveal, rocks no. 29 and 30. small boulders with engraved figures are randomly dispersed within the sheltered area for instance, rocks no. 30r, 30s, 30ş. the ana zaga shelter had been studied since the earliest archaeological fieldworks for its parietal engravings (jafarzade, 1973). however, the first archaeological investigation at ana zaga was launched in 1965 and conducted intermittently until 1986. this research activity led to the identification of approximately 28 engraved portable slabs, along with the documentation of thousands of other archaeological artefacts (lithic tools, bones, human remains, decorated pebbles, pottery). fortunately, some parts of the deposit were left in place, so that with the new project, it was possible to select key areas within the site where part of the deposit was covering engraved boulders, and the whole stratigraphic sequence could be reconstructed. the systematic review of both archive documentation and previously collected materials (portable art, engraved slabs, lithic industry) plays a key role in the new project, widening the spectrum of available information so to reconstruct the ancient setting of the site, to understand the links between daily and symbolic spaces, to fix a solid chronological frame for the parietal art, and to suggest the cultural links behind the graphic production at a continental scale. finally, in other words cross-analysing different fig. 20 (a) the roman inscription at the feet of böyükdaş; (b) rock no. 91 in jingirdağ-yazılitepe with the arabic inscription (photos: d. sigari). 60 sigari d. et al. qazıntılar. in azərbaycanın maddi mədəniyyəti. elm, baku, 90-101. muradova f. (2003) qobustanın tunc dövrü abidələrindən rəsmli daşlar. azərbaycan arxeologiyası və etnoqrafiyası jurnalı, 1, 47-54. muradova f. (2011) gobustan at the bronze age. yek production, baku, pp. 225. rustamov d. (1994) gobustan dünyasi. nurlar, baku, pp. 130. rustamov d. (2006) gobustan, the ancient centre of azerbaijan culture: devoted to the 80th anniversary of archeologist jafargulu rustamov. nurlar. baku, pp. 93. rustamov d., muradova f. (1980) археологическая работа 1977 года в гобустане. in аэи в азербайджане. elm, baku, 3-6. rustamov d., muradova f. (2008) kiçikdaş abidələri. e.l., baku, pp. 229. sauvet g., wlodarczyk a. (2000) l’art pariétal, miroir des sociétés paléolithiques. zephyrus, 217-240. shirinli s., abdullayev r. (2021) post-paleolithic zoomorphic images in gobustan rock art. "animals in prehistoric art. the mediterranean area and its surroundings” revista arkeogazte aldizkaria, 11 (special issue), 243-270. sigari d. (2009a) la roccia 44 di böyük daş (gobustan, azerbaijan): elementi per lo studio delle figure zoomorfe nell’arte rupestre all’aria aperta nell’arco alpino e in europa. bullettin d’etudes préhistoriques et archeologiques alpines, xx, 151-160. sigari d. (2009b) la roccia 44 di böyük daş, nel quadro dell’arte rupestre del gobustan (azerbaijan). elementi per lo studio delle figure zoomorfe di stile paleo-epipaleolitico all’aria aperta. università degli studi di milano. sigari d. (2013) palaeolithic rock art in gobustan, azerbaijan, the rock 44 of böyük das, gobustan. journal of iranian archaeology, 4, 15-22. sigari d. (2016) goddesses’ art. feminine representations in gobustan rock art. arkeos. proceedings of the xix international rock art conference ifrao 2015 (cáceres, spain, 31 august 4 september 2015), 37, 521-522. sigari d. (2017) portrayal of a sea in a semiarid environment: boat engravings in böyük daş, gobustan. journal of arid environments, 143, 57-63. doi: 10.1016/j.jaridenv.2016.12.012 sigari d. (2020) the sea on the rocks. sailing in the rock art of gobustan. in biglari f., nokandeh j., naderi beni a., hozhabri a. (eds.), human and the sea. a review of thousands of years of relationship between humans and the sea in iran. national museum of iran and ports and maritime organization of iran, tehran, 165-173. sigari d., garcía-diez m., shirinli s., abdullayev r., ochoa-fraile b., vaquero m. (2020) gobustan. un laboratorio su roccia. archeologia viva, 205, 52 -61. sigari d., shirinli s., abdullayev r. (2019) gobustan rock art cultural landscape. in smith c. (ed.), encyclopedia of global archaeology. springer, cham, 4618-4625. doi: 10.1007/978-3-319-51726-1_2827-1 van de velde s., wesselingh f.p., yanina t.a., anistratenko v.v., neubauer t.a., ter poorten j.j., vonhof h.b., kroonenberg s.b. (2019) mollusc doi: 10.1134/s0001437021010021 crist w., abdullayev r. (2024) herding with the hounds: the game of fifty-eight holes in the abşeron peninsula. european journal of archaeology, 28(1), 61-80. doi: 10.1017/eaa.2024.24 delporte h. (1990) l’image des animaux dans l’art préhistorique. picard, paris, pp. 254. dieterich t., askerov e. (2024) feasibility study for introducing saiga to azerbaijan-site comparison. astana, baku, pp. 41. dolukhanov p.m., chepalyga a.l., lavrentiev n.v. (2010) the khvalynian transgressions and early human settlement in the caspian basin. quaternary international, 225(2), 152-159. doi: 10.1016/j.quaint.2009.10.039 farajova m. (2009) rock art of azerbaijan. aspoliqraf, baku, pp. 373. farajova m. (2012) pleistocene art in azerbaijan. préhistoire, art et sociétés l’art pléistocène dans le monde / pleistocene art of the world / arte pleistoceno en el mundo, actes du congrès ifrao, tarascon-sur-ariège, septembre 2010, symposium « art pléistocène en asie », numero special, 929-942. farajova m. (2018) about specifics of rock art of gobustan and some innovative approaches to its interpretation (“firuz 2” shelter). quaternary international, 491, 78-98. doi: 10.1016/j.quaint.2017.07.034 fossati a.e. (2018) messages from the past: rock art of al-hajar mountains. ministry of heritage & culture-sultanate of oman, muscat, pp. 332. francfort h.-p., klodzinski d., mascle g. (1990) pétroglyphes archaïques du ladakh et du zanskar. arts asiatiques, 45(1), 5-27. doi: 10.3406/arasi.1990.1275 garcía-diez m., sigari d., abdullayev r., ochoa b., shirinli s., vaquero m. (2020) gobustan (azerbaiyán). los orígenes del arte entre europa y asia. arqueología e historia, 28. https://bit.ly/3jt48wt (access: 30/05/2025). jafarzade i.m. (1973) qobustan. qayaüstü rəsmlər. nurlar, baku, pp. 321. karimi e., heydarian m., alirezazadeh m., ghorbani h. r., sarikhani m. (2020) ibex in context: a new insight into the meaning of the ibex depiction in the rock art of iran based on new findings from mount eüji-iti in central western iran. archaeological research in asia, 23, 100211. doi: 10.1016/j.ara.2020.100211 kubarev v.d. (2010) khar chulu: a new rock art site in the mongolian altai. archaeology, ethnology and anthropology of eurasia, 38(2), 89-96. doi: 10.1016/j.aeae.2010.08.012 leroi-gourhan a. (1992) l’art pariétal. langage de la préhistoire. jerome million, grenoble, pp. 420. mamedov a.v. (1997) the late pleistocene-holocene history of the caspian sea. quaternary international, 41-42, 161-166. doi: 10.1016/s1040-6182(96)00048-1 molodin v.i., cheremissin d.v. (1999) pétroglyphes de l’âge du bronze du plateau d’ukok. a propos des représentations de personnages avec une coiffure fongiforme. arts asiatiques, 54(1), 148-152. doi: 10.3406/arasi.1999.1440 muradova f., rustamov d. (1993) yazılıtəpədə arxeoloi 61 rock art relationships between central asia and europe: the role of gobustan (azerbaijan). https://bit.ly/3jt48wt welter-shultes f. (2012) european non-marine molluscs, a guide for species identification. planet poster editions, goettingen, pp. 760. biodiversity in late holocene nearshore environments of the caspian sea: a baseline for the current biodiversity crisis. palaeogeography, palaeoclimatology, palaeoecology, 535, 1-15. doi: 10.1016/j.palaeo.2019.109364 vereshagin n.k. (1981) paleontologist’s notes. in the footstepsof ancestors. nauka, leningrad, pp. 167. (in russian). yanina t.a. (2012) correlation of the late pleistocene paleogeographical events of the caspian sea and russian plain. quaternary international, 271, 120129. doi: 10.1016/j.quaint.2012.06.003 62 sigari d. et al. ms. received: june 16, 2025 revised: july 10, 2025 accepted: july 12, 2025 available online: july 18, 2025 imp.napoleone ccaalliibbrraattiioonn ooff tthhee uuppppeerr vvaallddaarrnnoo bbaassiinn ttoo tthhee pplliioo--pplleeiissttoocceennee ffoorr ccoorrrreellaattiinngg tthhee aappeennnniinnee ccoonnttiinneennttaall sseeqquueenncceess ggiioovvaannnnii nnaappoolleeoonnee11,,22,, aannddrreeaa aallbbiiaanneellllii11,, aauugguussttoo aazzzzaarroollii11,,22,, aaddeellee bbeerrttiinnii11,,22,, mmaauurriizziioo mmaaggii11,, mmeennoottttii mmaazzzziinnii22 1dipartimento di scienze della terra, università di firenze, via la pira, 4 i 50121 2museo di storia naturale, sezione di geologia e paleontologia, università di firenze, via la pira, 4 i 50121 e-mail: napo19@unifi.it albix@geo.unifi.it abertini@geo.unifi.it menotti@unifi.it abstract the upper valdarno continental sequence is formed by 500 m thick sediments calibrated to gauss and matuyama chrons, for nearly 2.5 my history. continuity in lacustrine and fluviatile deposition is interrupted by two major pulses of the apennine uplift. one is dated to the boundary of the gauss/matuyama chrons at 2.58 ma and lasts until 2.1 ma, the other from shortly after the olduvai chron at 1.77 ma until 1.05 ma (jaramillo), or 0.78 ma (brunhes). such interruptions are recorded differently. the former by a condensed sequence containing two events of the magnetic polarity, the g/m boundary and the short normal chron reunion within the early matuyama, while the second missed any record. the condensed sequence is of wind-blown sands, with scanty levels of fine silt, used also for pollen analyses. the deposition intervals, now dated in the lacustrine sequences, are similarly long. in the first basin filling, from mammoth at 3.3 ma, the lake deposits of uniform silty clays, the meleto clays, began at nearly 3.15 ma, from shortly before kaena through the latest gauss. this time span was separately measured by spectral content of the magnetic signal to last 400 ky; there, cyclostratigraphy enhanced periods of various lengths accounting for either different rates of deposition through the time series or the occurrence of a bimodal cyclicity at 2.85 ma. at this time, the pollen record started moving towards a reduction of species of the subtropical forest and an increase of the altitudinal coniferous vegetation; an oscillating pattern from open to forest vegetation took place in the early matuyama. in the second lacustrine cycle the record is less continuous, and the highest percentage of herbs is reached at nearly the p/p boundary. key villafranchian faunas, from triversa or villafranca d’asti sequence of north-western italy to pirro faunas of south-eastern italy, were grouped in the biochronologic sequence of different faunal units, and are now correlated with the upper valdarno chronostratigraphic framework. after the early villafranchian, the montopoli fauna, the only one with a date (2.58 ma) before the calibration of the upper valdarno, marked the major change with the preceding fauna of triversa, leading to the middle villafranchian. the other faunas formed the late villafranchian, from olivola of north-western apennines to tasso of upper valdarno and farneta in central italy to pirro, which were little affected by the global changes occurred at the p/p boundary. after the villafranchian age, the new fauna starts to build the asset of the present day distribution at the end of the matuyama, and possibly at the boundary with the jaramillo chron, as recorded also in the upper valdarno. devoid of a direct calibration, these faunas containing the mammal neogene (mn) age units mn16a mn16b and mn17 of western europe faunal distribution, had always been very difficult to correlate with biostratigraphy, and even more with the geomagnetic polarity time scale gpts. they are now placed relative to the upper valdarno magnetochronology, from mammoth to jaramillo. the high resolution of the upper valdarno is viable for finer enhancements in the apennine sequences explored by direct magnetostratigraphies. these will permit the dating of their complete faunal sequences and correlate them with the european late-neogene mammal faunas. riassunto la datazione dei depositi continenali del valdarno superiore è stata effettuata per una estensione di ca. 2.5 milioni di anni (ma), ricostruendo dai vari affioramenti, lungo 30 km di estensione del bacino, la successione sedimentaria. su entrambi i fianchi della valle, essa è stata testimone di diverse quantità di apporto e di erosione, nel corso della sua storia intervallata da due fasi tettoniche che ne hanno segnato l'assetto. la più intensa è datata con inizio in prossimità del limite tra i magnetocroni a polarità normale gauss (c2an.1n) e matuyama (c1r.3r) inversa, a 2.58 ma. essa è responsabile della netta dislocazione del fianco orientale del bacino che ha depresso il bordo delle argille lacustri (a. di meleto) con un'inclinazione a ne di oltre 30°. la seconda crisi tettonica segna la fine della seconda fase deposizionale, con il riempimento del bacino in corrispondenza della crisi climatica globale alla fine del pliocene che segna il limite con il pleistocene. gli ultimi depositi di questo ciclo sono datati fino a dopo il debutto della nuova fase, cioè ad un'età appena più recente del limite plio-pleistocene, superando di poco la fine del crono olduvai (c2n) che è alla data di 1.77 ma. la terza fase si apre senza apparenti discordanze nel versante a destra dell’arno e con una di valore modesto, nel versante sinistro. molto più consistente è invece il salto cronologico: esso coinvolge quasi tutta la porzione post-olduvai del matuyama (c1r.2r), per almeno 650 mila anni (ka), prima della nuova fase, segnata con una breve alternanza di magnetizzazione inversa e normale. nella scala gpts dei tempi magnetici la prima polarità normale dopo l'olduvai si riscontra alla data di 1.05 ma, jaramillo (c1r.1n), e la seconda, brunhes (c1n), alla data di 0.78 ma alla quale è calibrato il limite del pleistocene medio. a questi punti fermi magnetocronologici si aggiungono quelli forniti dagli eventi sedimentari più rimarchevoli, che accompagnano i cambiamenti protrattisi per durate notevoli; anche queste durate, segnate dallo scorrere di una deposizione con velocità non sempre costante, sono state misurate. i primi depositi sono i conglomerati di base (ciottolami di spedalino), che cominciano alla data di oltre 3.3 ma nel mammoth (c2an.2r) e poggiano sul basamento oligo-miocenico delle arenarie del macigno. la deposizione assume quindi un regime continuo in acque molto basse, con il breve episodio di accumulo palustre di ligniti, che lateralmente al piccolo lago poggiano direttamente sul basamento. il livello più basso di ligniti è compreso tra la fine del breve crono a polarità normale (c2an.2n) prima del kaena (c2an.1r) e l’inizio di quest’ultimo, cioè in un breve intervallo valutabile in qualche decina di ka a cavallo del limite a 3.11 ma. a questa data è ricondotta l’età della prima fauna a vertebrati, che aveva fornito la datazione precedente dei depositi palustri all’inizio del villafranchiano. quindi il depocentro si approfondisce e si depositano argille sabbiose e limi (argille di meleto) la cui sedimentazione continua si estende per tutto il gauss terminale (3.04÷2.58 ma), senza però raggiungerne il limite, perché interrotta dal riempimento sabbioso del lago. la ricostruzione della serie deposta durante il gauss (senza nessun reperto fossilifero) è stata effettuata attraverso l’analisi spettrale della oscillazione continua del segnale magnetico. essa ha fornito la ciclostratigrafia della serie fino ai 60 ka prima del limite, cioè fino alla data di 2.64 ma, dopo dei quali si depositano rapidamente le sabbie di riempimento del lago (sabbie di s. donato). una foresta subtropicale di clima caldo umido è presente durante la formazione della lignite in un ambiente di palude arborata e prosegue per buona parte della successiva prevalente deposizione lacustre. il progressivo fenomeno di raffrescamento, segnalato dai “record marini” come più evidente a partire da circa 2.77 ma, determina una progressiva riduzione degli elementi più termofili e il contemporaneo aumento delle conifere di altitudine tipiche oggi delle foreste boreali. non si registrano variazioni significative nei valori delil quaternario italian journal of quaternary sciences 1166(1bis), 2003, 131-166 132 g. napoleone et al. 11.. iinnttrroodduuccttiioonn the continental deposits of the upper valdarno represent a fundamental key for timing the major apennine uplift during pliocene and pleistocene (fig. 1). also their fossil record of mammals became famous in the late seventeen hundreds and was studied in the early eighteen hundreds with a decisive contribution to the development of palaeontology. the first represented fossil was the proboscidean jaw reproduced by nesti in 1808, followed by rich collections. during the last 50 years the museum collections were reconsidered, and thence arranged in the villafranchian biochronological sequence (azzaroli, 1977a) which was further enriched l’umidità, i quali invece risulteranno fortemente alterati in seguito all’instaurarsi dei cicli glaciali/interglaciali a partire dall’inizio del matuyama. alle sabbie di san donato seguono in discordanza le sabbie della fase di erosione e inclinazione degli strati verso ne (rena bianca): nei pochi livelli limosi misurati, esse hanno fornito tratti discontinui di una polarità normale alla base, seguita da una inversa, ed interpretati come il limite gauss-matuyama, fino al breve crono con polarità normale, reunion (2.15 ma), e l’inizio di una nuova parte del matuyama c2r.1r, con i limi della nuova fase fluvio-lacustre della serie del ciclo di montevarchi (limi di terranuova). questa serie è in continuità sulle sabbie della rena bianca, nella parte più occidentale in sinistra d'arno; nella serie del depocentro affiorante in destra d'arno il contatto non è stato mai rinvenuto. qui, il nuovo livello argilloso affiora nel letto dell’arno e la sua età è prossima a 2.1 ma; il primo livello fossilifero, invece, è alla data di 1.99 ma. esso inaugura la nuova fauna del villafranchiano superiore, che nella sezione di faella si rinviene con una distribuzione stratigrafica di 220 ka ed è parimenti datata con la correlazione magnetostratigrafica poco dopo l’olduvai. infatti, nella sezione composita di faella e galleria tasso, la serie procede con l’inizio del magnetocrono a polarità normale olduvai a 1.95 ma. la sua prima porzione arriva a 1.815 ma, seguita da un breve tratto a polarità inversa fino a 1.785 ma ed un nuovo normale fino a 1.77 ma, secondo la calibrazione effettuata nello stratotipo della vrica. in quest'ultimo, il limite p/p è definito a 1.796 ma, entro la breve inversione al tetto dell’olduvai. in ca. 300 ka intorno al limite p/p è racchiuso tutto l’arco del villafranchiano superiore presente nel valdarno superiore fino all’unità faunistica tasso, che però costituisce la grande maggioranza delle collezioni del museo di firenze. gli elementi di una foresta subtropicale-temperato calda progressivamente sempre più impoverita nei suoi elementi più termofili si alternano a quelli erbacei tipici di una vegetazione aperta nella quale trovano spazio anche numerosi elementi steppici. nei sedimenti della rena bianca, il passaggio gauss-matuyama, è marcato dalla prima registrazione testimoniante l’espansione della vegetazione steppica con artemisia che raggiunge per la prima volta valori dell’ordine di oltre il 20%. con tali punti di controllo, datati con l’accuratezza di 10 ka, entro la quale si ritiene compresa la durata di transizione da una polarità all’altra, anche le date di tutti gli eventi faunistici, pollinici e sedimentari sono fissate lungo la serie, con accuratezze cioè di qualche ka. in particolare, per quelli del secondo ciclo sedimentario di montevarchi che risultano continui per la durata complessiva da ca. 2.05 ma a ca. 1.75 ma, gli eventi faunistici sono scanditi entro 2 ka e quelli vegetazionali correlati con le alternanze delle ciclicità astronomiche di milankovitch misurate dalla distribuzione spettrale del segnale magnetico. gli eventi faunistici sono quelli classici del villafranchiano superiore successivi alla fauna di olivola della toscana settentrionale. sono costellati da depositi fossiliferi fra i più cospicui, come la fauna del tasso della fine dell’800 e quella di poggio rosso della fine del 900, nonchè dai reperti isolati che sono stati riposizionati nella serie di montevarchi, come il rinoceronte di nesti del 1811 e l’elefante di azzaroli del 1953. ora, queste collezioni del museo di firenze sono datate insieme con la calibrazione del limite p/p rapportato alla stratotipo della vrica. quindi, così come alla vrica, il limite p/p è marcato dall’instaurarsi di una fase glaciale che si traduce in un’espansione della vegetazione erbacea, e tale fase è preceduta da una lunga fase calda ed umida. i successivi cicli glaciali-interglaciali si differenziano ulteriormente da quelli pliocenici per una notevole riduzione nella diversità floristica determinata dalla progressiva scomparsa nel corso del pleistocene di numerosi taxa (ad esempio taxodiaceae, cathaya e tsuga). le sabbie di oreno sovrastanti le argille di ascione chiudono il ciclo di montevarchi, e con esso termina il villafranchiano nel bacino del valdarno superiore. la sedimentazione riprende dopo una interruzione non valutabile, sul versante destro dell'arno, in mancanza di una serie magnetostratigrafica: nella parte se del bacino, presso lévane (cava specchiano), pochi livelli limosi nei ciottolami di laterina e nelle sabbie di lévane hanno fornito una polarità inversa attribuita al matuyama superiore. sul versante sinistro, nella zona a sw presso bucine (cava gori), i conglomerati sono a polarità inversa e i limi e le argille soprastanti a polarità normale. la ricca fauna di bucine, rinvenuta negli strati sabbioso-ghiaiosi a copertura degli ultimi depositi, nettamente post-villafranchiana, era anzi rapportata ai tempi del pleistocene medio terminale sulla base delle evidenze archeo-antropologiche di reperti litici. sia che il salto di polarità corrisponda ai tempi magnetici del crono jaramillo che a quelli del brunhes, rimane l'importante indicazione che il tempo trascorso dopo gli ultimi depositi della serie di montevarchi è vicino a/o raggiunge 1 ma, che è pertanto il salto dalla fauna del tasso a quella di bucine. da tale quadro cronologico emergono le condizioni per calibrare gli eventi faunistici e floristici dei bacini intermontani dell’appennino, correlandoli con quelli del valdarno superiore. il prototipo è dato dal bacino tiberino. il “record” pollinico della formazione di fosso bianco è stato calibrato direttamente con la magnetostratigrafia, per 600 ka, durante il gauss terminale ed il matuyama fino a tutto il reunion. l’unica indicazione cronologica è data dalla ridotta associazione faunistica di todi, rinvenuta a cava toppetti nella sovrastante formazione di ponte naia ed attribuita al villafranchiano medio, tra le età dell'unità faunistica di montopoli (calibrata a 2.58 ma) e quella di olivola (ora datata a ca. 2.1 ma): essa risulta perciò entro confini molto ristretti, intorno ad una età prima di olivola, ma certamente non prima di 2.15 ma, essendo posteriore al reunion. per gli altri bacini, nonostante la mancanza di controlli magnetostratigrafici diretti, le età che erano state fissate con i criteri biocronologici vengono ora circoscritte intorno a date che le hanno talvolta spostate notevolmente. la stessa durata del villafranchiano, ritenuta nel valdarno superiore estendersi dal pliocene medio a circa la fine del pleistocene inferiore, è stata accorciata all’età biostratigrafica di poche decine di ka dopo l’inizio del pleistocene. nella calibrazione alla scala gpts questo comincia nell’olduvai terminale, a circa 1.8 ma e l’età del villafranchiano arriva nel valdarno superiore a ca. 1.75 ma, cioè con una riduzione di 600-700 ka rispetto a quanto implicato dalle precedenti correlazioni indirette. con la completezza del quadro magnetocronologico del valdarno superiore possono essere correlate le faune principali dei bacini appenninici, e gli eventi sedimentari e floristici rinvenuti nei due versanti della catena. in particolare, viene riportata la nuova interpretazione della successione stratigrafica dei depositi faunistici, a partire da quello di villafranca d’asti, come rieferimento per il villafranchiano, che risulta coevo con quello di castelnuovo dei sabbioni. seguono le età di montopoli (già nota, a 2.58 ma) e di olivola ora interpretata a 2.1 ma, mentre quelle di tasso e farneta sono molto prossime fra loro ed entrambe appena dopo il limite pliopleistocene; quella di pirro alquanto indefinita. il passaggio alla fase nuova che prelude alla fauna attuale è marcato al crono jaramillo, 1.05 ma. key words: magnetochronology, upper valdarno basin, villafranchian faunas, pliocene correlations, pleistocene boundary, vegetational changes, climate changes. parole chiave: magnetocronologia, valdarno superiore, faune villafranchiane, pliocene, pleistocene, variazioni climatiche. by various details (azzaroli, 1977b; 1983; 1992; 1995; 1998; 2001; azzaroli et al. 1988; 1997), until magnetostratigraphy provided the dates for the whole record beginning from nearly 3.1 ma (fig. 2). in a framework related to the geomagnetic polarity time scale (gpts), the new historical reconstruction of the upper valdarno faunal sequence is correlated with great confidence with the sedimentologic and climatic ones. magnetic stratigraphy has in fact demonstrated the onset of the continental deposition at 3.3 ma and of the lacustrine facies at 3.1 ma, when the first faunal sequence was also recorded (albianelli et al., 1997). its end was close to the gauss/matuyama boundary. a second lake developed at 2.1 ma and a new fossil record has been dated since 1.99 ma (cioppi & napoleone, 2001, napoleone et al., 2001c, albianelli et al., 2002a). in the mean time, the sedimentary features showed a marked change in the 450 ky time series of the first lake with a gradual increase of the deposition rate by more than 60% from the middle to the end of the late gauss chron (albianelli et al., 1999, napoleone & albianelli, 2002). it was recorded by the magnetic signal as mainly related to milankovitch climatic changes that were also recorded by the pollen distribution (bertini, 1994; bertini & roiron, 1997). two results emerged from these studies. one was to date the turnover of the milankovitch precessional signal towards the obliquity one at 2.85 ma, when also the pollen of warm-temperate forest began to change towards a cooler vegetation and later alternate with the warmer one at nearly the 133calibration of the upper val d’arno basin ... gauss/matuyama boundary. the other one was to find the pliocene/pleistocene boundary with the same features as in the stratotype (van couvering, 1997), and to record the acme of the pollen concentration up to 89% of steppe herbs in proximity of that boundary. the present contribution summarizes these results and the ones from additional studies not reported in specific accounts, with the aim of developing the comprehensive history of the basin directly calibrated to the numerical dates of the gpts. we briefly review the classical faunas of the upper valdarno as illustrated by azzaroli et al. (1988), together with the faella small collection now revised in its composition because of new acquisitions in the inventory of specimens from different levels of the faella clay pit. other specimens were also considered from the finds accurately reported in the automated catalogue of the museum of firenze (cioppi et al., 1996). accuracy on their stratigraphic position reflects on their datings, with a confidence of 2 to 15 ky, that build the base for correlation of most apennine faunas which were until now approximately placed in the biostratigraphic chronology, and fairly incorrectly related to the gpts. 22.. bbiioocchhrroonnoollooggiicc hhiissttoorryy ooff tthhee uuppppeerr vvaallddaarrnnoo sseeqquueennccee the early geologic reconstructions were made for the italian peninsula, at the same time when also the upper valdarno chronostratigraphy was established. its continental deposits were classified in the general asset of the marine sequences, with the pliocene clay (blue clay formation) overlain by the pleistocene sand (cocchi, 1856; pareto, 1865). both successions were believed to be of equivalent geochronologic resolution, and biochronology of the mammal age classification was associated with the biostratigraphic classif ication. the villafranchian defined by pareto (1865) for the triversa vertebrate fauna of vil lafranca d'asti in piemonte (north-western italy) was later extended to the sequences of peninsular italy, and its onset related to the early pliocene (azzaroli, 1977a), in its twofold definition before a third stage was recently introduced for the latest pliocene. the mid villafranchian is represented by the montopoli fauna, collected in the lower valdarno basin, and related to the late pliocene, while the olivola fauna of late villafranchian collected in northwestern toscana was assumed to mark the beginning of the pleistocene. magnetochronology has now figure 1 general tectonic setting of the intramontane basins along the northern apennine belt (modified, after martini and sagri, 1993). the upper and lower valdarno, south and west from florence, respectively, and valtiberina farther south from upper valdarno are the only ones here taken into account for their direct calibration by magnetic stratigraphy, but their features are typical throughout the italian peninsula. 134 fixed new dates for the pliocene and pleistocene, so that the previous correlation used for assigning an age to the major turnovers in the terrestrial fauna is recognized to diverge from the ones of the marine record. the main difference is at the pliocene/pleistocene boundary, which did not mark any vertebrate diversification, as pointed out from the following facts (to be discussed in the chapter on calibrations). the earliest turnover of vertebrate associations (azzaroli, 1983) took place at 2.58 ma, the boundary between the gauss (c2an.1n) and matuyama (c1r.3r) chrons, which also calibrates to the gpts the boundary of the middle to late pliocene (berggren et al., 1995). the next one marked the extinction of the main taxa which are no longer represented in the presentday faunal associations and was dated at the jaramillo chron, approximately 1 ma (azzaroli, 1995). the mid pleistocene boundary was calibrated to the following chron of brunhes, while the onset of the quaternary recorded only the so-called “wolfevent” with the arrival of a new canis (xenocyon) overlapping the previous mid villafranchian one (torre et al., 2001). this lack of major events was also one of the reasons why the pleistocene boundary had a late recognition (pasini & colalongo, 1997) and correlation with it of the italian mammal fauna was actually made through the himalayan sequence (azzaroli et al., 1997), calibrated to the pliocene and pleistocene by its magnetostratigraphy (azzaroli & napoleone, 1981). with calibration of the stratotype to the gpts at the date of 1.796 ma, also the upper valdarno series is defined by the same dates, including the boundary at the pliocene/pleistocene, and the various ages before and after it which become actually correlated at the highest resolution with their faunal events. the main aspects of the upper valdarno faunal record are recalled here, as they represent most reference events for the villafranchian vertebrates of the italian peninsula and will put the benchmarks for magnetochronologic calibration of several of them. the first fauna of castelnuovo dei sabbioni (early villa-franchian) is separated from the next one of the montevarchi sedimentary cycle (late villafranchian) by the wind blown and unfossiliferous sands of rena bianca. its intermediate position, covering the middle villafranchian age actually missing in the upper valdarno, is represented by a single fossil which has been hitherto allegedly found, a partial skeleton of a mastodont described and partly figured by nesti in 1826, and now referred to anancus arvernensis by azzaroli. the fossil was restored and is exhibited in the museum of firenze; its provenance was not reported by nesti and the position in the rena bianca is here only inferred. g. napoleone et al. figure 2 magnetostratigraphic asset of the upper valdarno sedimentary sequence used for dating the villafranchian faunas and implemented by the present results. the basic figure was after albianelli (1995), and first used in cioppi and napoleone (2001). an important change is now introduced, after recognizing the unconformity between rena bianca and san donato sand units, so that they are split in two zones belonging to the montevarchi cycle and to the castelnuovo cycle, respectively. the san donato sand represents therefore a short time span, and rena bianca a condensed sequence to which the valtiberina profile at todi provides a full extent for correlation. the montevarchi sequence is synthesized from various profiles; the filling sediments are not reported herein. 135 22..11 tthhee ccaasstteellnnuuoovvoo ddeeii ssaabbbbiioonnii llooccaalliittyy the mining of the lignite-bearing levels of the basal unit yielded few fossil specimens kept in the university museum of firenze. the small collection assembled as the castelnuovo dei sabbioni fauna actually came from various sites of the old small mines (gaville, tegolaio, etc.), distributed in the area around the small town of castelnuovo dei sabbioni. the last and largest one at santa barbara provided extended outcrops used for surveying various sedimentary aspects, but its industrialized exploitement did not allow any fossil recovery (fig. 3). the fauna is characterized by the mastodonts zygolophodon borsoni, anancus arvernensis, and by ursus minimus, the perissodactyl tapirus arvernensis, the turtle mauremys etrusca, the fish tinca sp. it has been correlated with the triversa fauna occurring at villafranca d'asti in piemonte and is characterized by the same faunal elements (azzaroli, 1977a). as the triversa assemblage was taken by pareto (1865) to represent the villafranchian terranes (see the discussion reported in azzaroli, 2001), the triversa locality was assigned as the base of the villafranchian stage, and the castelnuovo locality was accordingly positioned at the same time level. the rough chronostratigraphy derived from broad correlations with the marine sequences gave an age of pliocene, actually corresponding to a lower piacenzian as defined by pareto (1865). therefore, the castelnuovo fauna represents the earliest mammal assemblage from the apennine intramontane basins developed with the plio-pleistocene uplifting of the chain. the present date, produced by its magnetostratigraphic determination (see in chapter 5), is calibrated to the gpts and will be used (in chapter 6) to date more accurately the reference assemblage of triversa by a correlation better defined. calibration of the upper val d’arno basin ... figure 4 the earliest illustration of a fossil specimen from the upper valdarno old collections (after nesti, 1808, reproduced in azzaroli et al., 1992). this proboscidean was tentatively attributed by azzaroli to anancus arvernensis. figure 3 the outcrop of the meleto clay in the santa barbara pit, opened for the exploitement of the l ignite seam. in the foreground, the lignite-bearing level has already been removed, and the paleomagnetic survey has been carried out up to the top. the sampling for palynology was conducted earlier, in the profile on the left side of the section, 1 km away. 136 22..22 llooccaall ffaauunnaass iinn tthhee mmoonntteevvaarrcchhii sseeqquueennccee in this complex, forming the second depositional cycle, the bulk of the upper valdarno fauna stored in the palaeontological museum of firenze has been collected since early eighteen hundreds, and a large collection is also stored in the famous museum of montevarchi, the town from which the succession is named. the first catalogue of the upper valdarno fossils in the museum of firenze was assembled by filippo nesti in 1845, and contained the list of 356 specimens (azzaroli et al., 1992). some of them are in the exhibition, representing the best pieces for the study collection, and were studied in detail to create the base for the developments in palaeontology. the earliest description, dating from 1808, is a toothless jaw of a then unnamed proboscidean; it belongs to a mastodont, likely from the older lake of castelnuovo dei sabbioni and tentatively assigned to anancus arvernensis (fig. 4). a second fossil was the rhinoceros described by nesti in 1811 (a pelvis and the four limbs), named rhinoceros etruscus, and now stephanorhinus etruscus. the detailed description of the site location has now been reconsidered for dating the embedding sequence, and the level of provenance recognized in the sequence of poggio di monte al pero, which is the hill peak by the side of matassino, another important fossil site. these localities are both dated with high resolution by magnetostratigraphy of their sequences, as reported in chapter 5. the oldest fossils collected so far in the montevarchi sequence are an antler of a juvenile cervid, pseudodama nestii (fig. 5) acquired in the catalogue on april 1999, and a tibia of the equus stehlini acquired in the catalogue on january 2000, with specimens of a few more species. they all come from the lowermost 10÷15 m of the faella section, 2 km away from that of matassino, on the right (eastern) bank of the arno river (see on map of fig. 8). as discussed in the next sections, the faella outcrop represented the key for new insights into the biochronologic history of the upper valdarno, because the whole fauna collected in two centuries from this area and resumed from the catalogue was calibrated, thus becoming the reference for the equivalent faunal collections. in fact it spans all through the montevarchi succession from which most of the fossil sites were retrieved. the species list of the faella small collection of 29 specimens includes pachycrocuta brevirostris, leptobos etruscus, leptobos vallisarni, sus strozzii, eucladoceros dicranios, canis arnensis, ursus etruscus, archidiskodon meridionalis, pseudodama nestii, equus stehlini. they are now dated in stratigraphical sequence, as will be discussed in the magnetochronologic section, even if a provenance of the specimens in the old collections was not reported (napoleone & azzaroli, 2002). cocchi (1867) made an important recovery at the same level as the base of the faella section, just across the faella creek and at the foot of the monte al pero hill, with two additional genera: megantereon and rhinoceros (now stephanorhinus). the matassino hill is the northern flank of monte al pero, and culminates with the peak of poggio rosso. at its base, the matassino site was the first rich assemblage recovered in the uv as one single deposit (azzaroli, 1967), in a channelled sand pocket, with two young male and female elephants, the latter shown in figure 6. it was dated to the late villafranchian and represented until three years ago the oldest faunal assemblage in the montevarchi sequence, for which a close affinity with the olivola fauna was recognized (azzaroli, 1977a) and an age of earliest pleistocene was since established. the matassino local mammal fauna (lmf) is assembled in the catalogue list from 8 sites around the mentioned deposit and contains most of the species of the faella previous list, totalling 12, including the canis arnensis described by torre (1967). in the same sequence of the matassino locality, some 30 m higher up, a very rich fauna was discovered in 1995 (mazzini m. et al., 2000), the poggio rosso fauna, and is under preparation. a list of the specimens exhibited in the museum during 1997÷2002 included 13 species, archidiskodon meridionalis, equus stenonis, equus stehlini, stephanorhinus etruscus, leptobos etruscus, eucladoceros dicranios, pseudodama nestii, sus strozzii, pachycrocuta brevirostris, canis etruscus, canis arnensis, ursus etruscus, castor plicidens. the species are now 19 out of more than one thousand specimens restored and preliminarily examined; the complete list of more than 15 hundred specimens is not yet fully included in the automated catalogue. the fauna lies in a channelled sand pocket and was washed in by a stream during a flood. although the association has still to be defined, all groups being under study, there appear to be present the most characteristic elements that had been attributed for their analogies to the olivola faunal unit (reported later, in chapter 6), with the exclusion of the species endemic to that site and with the addition of equus stehlini, canis arnensis, castor plicidens and hystrix etrusca. the latter species was described from other sites of the basin by bosco in late eighteen hundreds (quoted in azzaroli, 1998). owing to transport by a stream the elephant is represented by few g. napoleone et al. figure 5 one of the most recent acquisitions (april 1999) of the upper valdarno fossils made by the natural history museum of firenze, the cervid antler of a juvenile specimen at the base of the faella clay pit, few meters by the side of the faella creek. in january 2000, a few meters underneath, the oldest fossils of the late villafranchian dated 1.99 ma have been found. bones of the hand. two complete skeletons of the elephant archidiskodon meridionalis m. were collected by azzaroli in the montevarchi territory, on the left bank of the arno. the one collected in 1949 is stored in the montevarchi museum, and a male skeleton was collected in 1953 on a hilltop at the borro quercio creek. the find of 1949 was recovered not far and at a level slightly higher than that of the other one, and determined as a young female individual of elephas meridionalis nesti (azzaroli, 1952). the find of 1953, stored in the museum of firenze, has been reappraised (azzaroli & napoleone, in ms) to report on its preliminary determinations and on accurate chronology of its level bed (fig. 7). a fairly rich fauna was collected in recent years near casa frata, not far nw of the town of terranuova bracciolini (borselli et al., 1980; de giuli & masini, 1986), and is still under study. it includes canis etruscus, canis falconeri (?), ursus etruscus, martes sp., pachycrocuta brevirostris, lynx cf. issiodorensis, acynonyx pardinensis, homotherium crenatidens, eucladoceros sp., pseudodama sp., equus stehlini, stephanorhinus etruscus and the limbs of a mediumsized, heavily built bovid, which has not yet been detected in other sites of the upper valdarno. the sequence containing the two major deposits of the casa frata assemblage is not well exposed and has not been studied for palaeomagnetism. from the vicinity of the area labeled in the museum catalogue as il tasso come: lepus etruscus, castor plicidens, mimomys savini, canis etruscus, canis arnensis, canis falconeri (now canis (xenocyon) ex gr. falconeri, rook, 1994), ursus etruscus, martes sp., pannonictis nestii, pachycrocuta brevirostris, lynx issiodorensis, panthera toscana, homotherium crenatidens, megantereon cultridens, stephanorhinus etruscus, equus stehlini, sus strozzii, pseudodama nestii, eucladoceros dicranios, leptobos vall isarni, archidiskodon meridionalis. the occurrence of equus stenonis and leptobos etruscus is doubtful, that of the hippopotamus antiquus included in the catalogue as belonging to this group will be discussed at the end of this chapter. several more localities with minor finds and/or of undetermined positions are classified in the catalogue, but their variability is not recognizable from the above mentioned localities already ordered in stratigraphic succession, as dated later by their magnetochronology. a large tusk of an elephant was collected by azzaroli and de giuli in 1975, west of montevarchi and near km 41 of the road from siena, at an altitude of 205÷210 m. it is decidedly larger than the tusks of the borro quercio elephant and other tusks from the upper valdarno and nearly equals in size to the specimens found near the farneta abbey in eastern toscana, to be discussed in the stratigraphical reconstructions of chapter 6. 22..33 aaddddiittiioonnaall ffaauunnaass aafftteerr tthhee pplleeiissttoocceennee bboouunnddaarryy the basin fill is recorded in a short succession overlying the eartliest pleistocene sand. the one exposed on the right-hand bank of the arno did not yield any fossil remains but the frontal skull of a bovid; on the lefthand side, in contrast, a rich assemblage was collected and labeled as the bucine local fauna, even if randomly found on the surface, in the area around pogi, south of the small town of bucine. these sediments extend in a flat area from bucine to ambra, beyond the southern margin of the valdarno basin at an altitude of 220÷240 m, unconformably sitting on the previous unit. in the late eighteen hundreds, during the reconstruction of the railroad from firenze to roma, a set of tunnels were opened near bucine at an altitude of 205÷207 m. in one of these, forsyth major collected a set of teeth of the reported late middle pleistocene equus süssenbornensis von reichenau (azzaroli, 1984). higher up in this area, near the village of pogi, a small fauna was collected in the 1960s and stored in the museum of firenze: 137calibration of the upper val d’arno basin ... figure 6 a specimen of the first fossil assemblege recovered at matassino by the staff of the museum of firenze, in a channelled deposit of sand and fine gravel interlayered in the terranuova silt level which is now dated as just preceding the onset of the olduvai chron at 1.95 ma (albianelli & napoleone, 2002, unpublished data). figure 7 the largest specimen in the exhibition of the natural history museum of firenze, collected in 1953 near montevarchi and now dated in the upper olduvai, at nearly 1. 85 ma (azzaroli & napoleone, 2002). mammuthus primigenius, a lower molar; equus ferus, a left metacarpal; dama dama, a left metatarsal; cervus elaphus, a right antler; stephanorhinus hemitoechus, a male skull; grus cf. cinerea, a partial humerus, tibio-tarsus. it was assigned an age of late, but not latest pleistocene. three upper and two lower molars referable to equus ferus (named equus caballus by azzaroli, 1984), and a left horncore of bison schoetensacki from the higher levels of the eastern margin of the basin were also described by the same author and were referred to the late pleistocene. the assemblage kept in the palaeontological collection of the montevarchi museum and of the high school of bucine comes from 11 collecting localities listed by mazza (1997), and used to reconstruct the taphonomy of their occurrence: elephas (palaeoloxodon) antiquus, mammuthus primigenius, stephanorhinus sp., equus gr. bressanus-süssenbornensis, sus scrofa, bos primigenius, bison priscus, cervus elaphus, dama dama, megaloceros sp., capreolus capreolus, ursus arctos, canis lupus, crocuta crocuta, castor fiber. the biochronologic dating of this fauna, although decidedly more derived than the villafranchian ones, is not sufficient to resolve its age in some detail. the age of late middle pleistocene (latest galerian ?) was arbitrarily assigned, lacking any stratigraphic correlation, as will be shown by its calibration. the efforts of cocchi (1856) and pareto (1865) to correlate continental sequences with the marine ones were not improved by the biochronologic attempts for dating deposition gaps of unknown duration. in the upper valdarno filling, this has been a major problem until magnetostratigraphy provided the numerical dating of their time intervals (napoleone et al., 2001c). a 30 m thick sequence, in the upper silt and clay underlying the final thin bed of sand, was surveyed for magnetics in a gravel and sand pit, in the vicinity of bucine. also in a shorter section of a similar pit, ca. 1 km away, the same sequence was sampled after an elephant tusk was reported by one of us (m. mazzini) on the 21st of october 2001, in the yellowish lenticular fluvial deposits. several remains of elephas antiquus were recovered on the 26th, 27th, and 29th of october, and the specimen is labeled in the inventory of the museum as igf 8215v. the fossil level was above the gravel bank and a less than 10 m section was sampled for magnetostratigraphy, including two clay and silt lenticular levels in the gravel bank. the hippopotamus of the upper valdarno, descibed by nesti and grouped with the large assemblage of specimens of the tasso faunal unit, devoid of a position within the montevarchi sequence, raises a problem. the fossils, which slightly differ from the living species, are plentiful. nesti gave no details on their locality, and no fossils of this species were collected in recent years, either in the upper valdarno or in younger deposits of the farneta area of val di chiana and the mugello basin, north of firenze (reported in chapter 6). this leads us to suppose that the hippopotami are of a younger age than the main upper valdarno fauna. the remains of a similar hippopotamus were collected in recent years farther east, at the boundary between umbria and marche districts of central italy, in the colfiorito basin, associated with other remains of postvillafranchian fossils (borselli et al., 1988). the upper valdarno fauna, owing to its richness and recent acquisitions, has not yet been studied with the detail it deserves. 33.. tteeccttoonniicc aanndd sseeddiimmeennttaarryy eevvoolluuttiioonn ooff tthhee bbaassiinn the arno river makes its 240 km path running from the casentino valley in east toscana, first south towards arezzo, and before reaching the town it turns west and then north to firenze, across the upper valdarno basin (fig. 1). after the firenze basin, it continues west cutting a series of hills and, in the lower valdarno basin, the shallow marine deposits of miocene and early pliocene. sometimes its early and mid villafranchian sediments interfinger with the mid pliocene ones. however, the fairly poor biostratigraphic resolution in this area never led the accurate dating of the vertebrate fossil sites that are also scattered in younger deposits, but never indicative of a faunal assemblage of biochronological significance. the upper and lower vardarno basins also had quite a different tectonic history, the latter responding to the pulses of the apennine uplift by mild sea level changes which formed several regressivetransgressive cycles in a circa-littoral environment (benvenuti et al., 1995). short-lived episodes of continental deposition and of minor areal extent are in contrast with the relatively long sequences accumulated in the marine facies. also the pollen distribution was different, recording changes largely reduced in ampliture and testifying a lagunar facies in the vegetation. sedimentation started in the upper valdarno directly with continental deposits, unconformably overlying the turbiditic sandstone of oligo-miocene age, and was affected by two main episodes of the apennine uplifting, which produced deep changes in its lacustrine sequences. these were in fact interrupted twice, for time spans which are now dated to represent long breaks in the history of the basin. similar breaks are expected to be found in the several intramontane basins of the apennine belt, and in the external apennines where are now dated coeval with the upper valdarno breaks (albianelli et al., this volume). 33..11 sseettttiinngg ooff tthhee bbaassiinn the general setting of the northern-apenninic architecture was described by merla (1951), and the upper valdarno disposition in its framework by abbate et al. (1971). a detailed survey of the basin led to the lazzeri (1977) map, from which the sketch of figure 8 is taken. in the present reconstruction only few references are quoted, without discussing the general framework developed since merla's (1951) modern views for the northern apennines and later reproposed with increasing details. the upper valdarno basin was re-visited by merla & abbate (1967) and azzaroli (1967) for their tectonic and biochronologic reconstructions. an updated tectonic and sedimentarry feature was provided by martini and sagri (1993), who restored the asset of the northern apennine basins as reported in figure 1, while the lazzeri (1977) map completed the scheme to which all studies on the upper valdarno record were later linked. a next step will be marked by the detailed new 138 g. napoleone et al. mapping, which is beginning in these days. it will be useful to report more widely on the previous works. the time implications on the history of the basin, until now established by the faunal distribution earlier mentioned, are shortly emphasized, although disregarding the tectonic reconstructions of the basin in relation to the close intramontane structures along the northern apennine belt. the basin is an asymmetrical depression, bordered on the north-eastern margin by the pratomagno ridge, which divides the upper valdarno from the casentino basin, and with a normal fault system of smaller displacements along the south-western margin by the chianti mts (merla & abbate, 1967; magi et al., 1992). these deeply regulated the sedimentary regime, which produced a number of local deposits. they have been grouped in two main sets, better exposed on either side of the arno river bank, one on the western border containing the earliest and latest sequences, and the other on the eastern bank with the richest fossil sites and of median age between the tectonic displacements of the apennine uplift now dated to last half a million years and nearly one million, respectively. during these ages, indeed, the deposition was also regulated by the climatic changes affecting the geologic system at the critical ages of the turnovers to the late pliocene and to pleistocene. they were recorded by the pollen and magnetic signatures, imprinted by their continuous changes throughout the series. therefore, our interest is directed to timing the main events in the history of the basin, which will provide the reference for the similar ones accompanying the time span of the apennine growth. it is notable that this growth also left traces in the external apennine marine sequences and their detailed correlation with the upper valdarno ones will be the next goal in dating the ages of the tectonic phases across the mountain belt. 33..22 tthhrreeee ddeeppoossiittiioonnaall ccyycclleess the upper valdarno sedimentary fill is made of three separate units, each marked by angular and/or erosional discontinuities (billi et al., 1991; martini & sagri, 1993); the bulk of its new asset is represented in figure 2, the dates for their events having been provided by magnetostratigraphy (albianelli et al., 1997; 2002a). it is here used to introduce the general aspects, while a more detailed reconstruction descending from the present study is reproposed in figure 18, with the actual series exposed on both sides of the valley and correlated by their magnetostratigraphy. the first phase developed in the south-western margin of the basin, with the fluvial-lacustrine deposition of the castelnuovo succession. it started with pebble and sand of alluvial fan type; after a while, the fine grained sedimentation developed, and rapidly moved to palustrine clay with thick lignite seams and to a decidedly lacustrine facies. the basin was filled up by sandy fluvial deposits (san donato sand) which are overlain by a more than 30 m thick level of wind-blown white sand, rena bianca (magi & sagri, 1996), recognized in recent cuts to unconformably stand on them. this deposit was the result that followed the strong apennine uplift which displaced and tilted to the ne the lacustrine deposits. for its disposition, it is now assigned to the overlying montevarchi sequence (fig. 2), thus deeply modifying the previous asset of the magnetostratigraphic reconstructions reported in previous papers (albianelli et al., 1997; cioppi & napoleone, 2001; napoleone et al., 2001c). the second lacustrine and palustrine phase developed in the central basin, which occupied a quite larger area than the previous one, with fan-delta deposits in the marginal sides (billi et al., 1991). the former facies is made of clayey-sandy silts, with frequent sand levels containing lignitiferous beds in their middle-upper part; the fan delta facies, in contrast, is made of coarse pebbly deposits passing to channelled sand and pebble. the lacustrine and palustrine sediments are represented by alternating sand and silt levels, grouped in the 80-90 m thick montevarchi succession. the third phase marks the filling of the basin and is separated from the second one by an erosional event, which is now known as a significant one as it represents an extended gap, whose duration still needed to be defined until magnetostratigraphy provided a date for its long duration (see in chapter 4). a fluviatile facies, the monticello succession, crops out in the axial zone, with alluvial fan sediments of the ciuffenna succession (fig. 2), in the vicinity of the pratomagno ridge and mainly in its south-eastern edge. in the wstern bank, indeed, the corresponding facies has released a rich fossil fauna. 3.2.1 the early lacustrine facies in the santa barbara profile a direct view of an outcrop in the open mine of santa barbara is shown in figure 3 and illustrates the full extent of the meleto clays, which were removed for quarrying the 15 m thick lignitiferous level. in the marginal area of the present view, the lignite seam directly lies on the arenaceous basement, which is exposed on the left-hand side of the picture as the wall of the basin 139calibration of the upper val d’arno basin ... figure 8 simplified sketch of the upper valdarno geologic map (redrawn after lazzeri, 1977, and magi et al., 1992). the basic sedimentary sequences are shown, together with some of the fossil sites mentioned in this paper. at the foot of the chianti mts. in the background, about 1 km away, the lowermost sediments are exposed, with the spedalino gravel and sand derived from the oligocene-miocene deposits of the basement, in which few fine-grained limy beds were also sampled for magnetic stratigraphy and palynology. farther off the margin, a few meter thick level of clay underlies the lignite seam and represents the beginning of the lacustrine sedimentation. so, this facies shortly precedes the palustrine one of the lignite-bearing level. the rapid accumulation of the latter, then, quickly moved back to the shallow-water lake deposits in the meleto area and in the extreme north-western edge of the basin. the 156 m section in the foreground of the picture (fig. 3) is in the clays above the lignites and was sampled for magnetics avoiding the more sandy beds; the one in the background was sampled for palynology a few years earlier, for nearly 300 m from the base. the lower part of the sequence, beginning with the aforesaid levels of the basal gravel and sand and nearly a half of the lacustrine clay, is entirely dominated by the pollen of warm, humid forest vegetation typical of subtropical to warm-temperate climates (e.g. taxodium/glyptostrobus type, nyssa, engelhardia, arecaceae, itea, symplocos, cephalanthus, clethraceae, cyrillaceae, myrica, carya, quercus, carpinus, ulmus, zelkova). the basin, after this phase corresponding to the development of a bog, moved toward cooler conditions, with some fluctuations, leading to an expansion of cooler forest; the herbs (including the steppe flora) remain a minor component. then, near the top of the meleto clays, the subtropical forest almost vanished, giving way to a great expansion of the coniferous boreal forests (with a large component of picea). this record is correlative with the reuverian of zagwjin (1960). the thickness of the lithologic profile is reported from the section measured for the magnetic stratigraphy, which was correlated with that for the pollen profile by several markers (fig. 2). it is formed by the clay and lignite seam, which were sampled in the cores of two drilling bore-holes, overlain by a thinner level of siderite before the next lignite seam; then a thick pile of silt extends upwards until the sandy beds begin to increase in thickness and frequency, progressing with the lake filling. these beds are recognized in short sequences from several sites but their total thickness is still tentative. 3.2.2 end of the castelnuovo cycle up to the rena bianca sand the time span for deposition of the san donato sand overlying the meleto clay and of the rena bianca sand is questionable, lacking adequate reference of fossil finds and sufficiently long exposures; only recent cuts for quarrying evidenced the unconformity of rena bianca with the underlying sand. this led to the separation of these two sandy units, which were earlier assumed as two different facies of the sand body separating the first lacustrine cycle from the second one. therefore, the short reversal measured in the lowermost rena bianca unit is interpreted as the gauss/matuyama boundary (fig. 2), and no more associated with the san donato sand as previously reported (albianelli, 1995; albianelli et al., 1997; 1999; cioppi & napoleone, 2001). in the san donato sands, instead, a strong resurgence of the warm forest is recorded by pollen, while at the base of the rena bianca sand, i.e. at the gauss/matuyama boundary, a drastic change has marked the withdrawal of almost all the forest taxa, leaving a profile dominated by herbs including a very large component of artemisia. above this, but still in the earliest matuyama, a great increase in the warm forest taxa and cathaya as well as a strong reduction of steppe elements are recovered. this phase can be correlated with the first glacial/interglacial cycles following the onset of the arctic glaciation reported at 2.6 ma and the praetiglian of zagwijn. an unconformity between rena bianca and the overlying series was never found until the latest intensive quarrying of the rena bianca sands has exposed their contact. the new silty facies is the very beginning of the terranuova unit in the montevarchi cycle, leading thus to the connection of rena bianca with the second lacustrine sedimentation (magi, unpublished data; ghinassi et al., in manuscript) this implies that most of the tilting of the meleto sand unit occurred before deposition of the rena bianca, i.e. in the very short time span preceding the gauss/matuyama boundary, and the rest took place in the longer interval before the new phase placed at nearly 2.1 ma (fig. 2). the pollen record there evidenced -at the gauss/matuyama boundarythe presence of an arid climate vegetation (bertini, 1994; bertini & roiron, 1997). therefore a wind blown origin for it was supported by the dates of the scanty interbedded silt levels at a time when the ice rafting of the pliocene had already started (shackleton et al., 1984). from the (lower part of) rena bianca presumably comes a single vertebrate fossil, the mastodont skeleton studied by nesti (1825) but reported without any account on its location. 3.2.3 the montevarchi cycle in the faella pit section the lacustrine and palustrine deposits of the montevarchi sequence mostly lie in flat bedding with an average thickness outcropping for 80÷90 meters, which is almost wholly included in the section of the faella pit (fig. 9), and its magnetostratigraphic profile is reported in figure 17. they are subdivided into three lithostratigraphic units, the first being represented by 30÷35 m of prevailing sandy silts and sands, the terranuova silt. the second one is a 20÷25 m thick horizon with peat or lignite and clays rich in organic matter, and with silt and sand interbeds, the ascione clay. the third unit is a ca. 30 m thick sequence mainly of sand, the oreno silt and sand, which also closes the lacustrine deposition in the central area of the basin. the surveyed sequence exposed in the faella pit, about half a km southwest of the faella village and on the right bank of the arno river, is ca. 70 m thick. in figure 9 most of its extent is shown in a fresh section (fig. 9a), starting at ca. 150 m level and slightly above the base of the present quarry (143 m). the lower sediments reach an elevation shortly above 185 m, and consist partly of the terranuova silt and the entire ascione clay, while in figure 9b the overlapping portion of the ascione unit extends in the oreno silt and sand, which reaches 207 m in a short section further in the back140 g. napoleone et al. ground. the actual thicknesses of the lithology profile are reported in the magnetostratigraphic profi le albianelli et al. (2002a), and reach 134 m at the base of the faella section (napoleone & azzaroli, 2002). on the right-hand bank the horizontal montevarchi sediments are overlain with a small angular discontinuity by the silt and sand of the successive sequence, and upstream (the south-eastern edge of the basin) the fluvial regime deposited the basal laterina gravel (fig. 2). the same gravel marks the unconformity of 15°÷20° dip, due ne, on the left-hand bank, although in the area nw of bucine it seems to lie on the intermediate unit (ascione) of the montevarchi sequence, possibly with a minor oreno level (fig. 10). in the faella section, the terranuova silt is represented by 25 m of mixed levels of more clayey and sandy grey silt, sometimes maculated and often bioturbated and pedogenized, and by sand with variable lime content, in widely extended flat beds. channelled sandy bodies are also present. some 20 m thick peaty clays of the ascione unit overlie the terranuova silt. brownish to grey-greenish clays alternate in beds of various thickness from few cm to some dm; interbeds of sand and silty-sand also alternate with a similar variable thickness. about 25 m of the mainly sandy oreno unit are exposed in the upper section, with thicker beds of sands also containing some lignite seams in a coarser sand-topebble facies which is usually rich in fossils. channelled bodies are here more frequent. a similar sequence was described by cocchi (1867) on the opposite hill of monte al pero, across the faella creek, and correlates with the lowermost faella profile. in the present section, then, the ascione clay is fully represented while the oreno unit is interrupted, partly because its sand was removed for industrial works. a close analogy of this sequence with the one brought to light at tasso (fig. 10), nearly 10 km south of faella, was found while surveying the outcrop for the new railroad tunnel. its sedimentary sequence showed the ascione and oreno units as at faella. the sedimentologic recognition on both sections led to closely correlate the upper ascione unit and basal oreno, and also drove more attention to the same units exposed in the matassino pit, 2 km away and closer to the arno river. even if palynological sampling was carried out in several sections, documentation of vegetational changes is less complete than in the castelnuovo succession and less continuous (bertini, 1994; albianelli et al., 1995). in fact the dominant silty and sandy sediments are generally barren or nearly barren of pollen and spores; in a few cases a high spore abundance along with concentricystes seems due to stream concentration. palynological data show a progressive reduction of subtropical/warm-temperate taxa that are mainly represented, although discontinuously, by cathaya (plus pinus haploxylon type) and taxodium. a sequence of steppeforest alternations, indicative of well established glacial/interglacial climatic cycles is recorded. steppe assemblages are characterized by non-arboreal pollen (mainly asteraceae included artemisia, poaceae, cyperaceae); forest assemblages by thermophilous arboreal pollen (mainly quercus, carya, carpinus, pterocarya, ulmus, zelkova). in particular at matassino, in the level beds from the poggio rosso fossil deposit to the level of nesti's rhino, a glacial-integlacial oscillation is recorded. in the upper part of the oreno silt and sand, at the tasso tunnel section, a significant increase of the herbs percentage (up to 89%) is measured; it is represented mainly by asteraceae cichorioideae, and marks a cold and dry phase correlated with the beginning of the eburonian of 141calibration of the upper val d’arno basin ... figure 9 the outcrop of the montevarchi sequence is better exposed in the faella clay pit. the profile for the lithology is controlled on the detailed survey of the area (magi, 1999), and that for the magnetic stratigraphy is the composition from the sampled sections shown after a fresh cut: in a the lower portion reaches 185 m in elevation, and in b the upper one is exposed, but not up to the end of the sequence, which was sampled up to 207 m level in a short section slightly beyond the peak (modified, after albianelli et al., 2002a). figure 10 the trench opened for the artificial tunnel of the new railroad roma-firenze, yielded the magnetostratigraphic profile shown by the side, and used with the previous one of faella for reconstructing the magnetostratigraphic reference section of figure 16 (modified after napoleone et al., 2001c). zagwijn in northern europe. this trend toward aridity coincides with a partial drying of the basin and a more frequent input of arenaceous sediments. 3.2.4 the third cycle: cava gori and c. minuto pits, on the western bank of the arno river this sequence is rather thin. its base is formed by a 6÷8 m thick gravel bank in the south-western edge of the basin, and by an equivalent sand bank more to the north. the gravel in the southern outcrops generally overlies the clay unit (ascione) of the montevarchi sequence, while the oreno sand is lacking. this is the case with the section in the cava gori pit, which was thoroughly sampled in the occasion of new outcrops which uncovered a 20 m deep well of roman age (fig. 11). the ascione clay underlying the basal gravel bank is tilted 17°; a 4 m thick sand covers the gravel and is followed by 5 m of silt and 4 m of clay rich in organic matter. on top, the coarse material of the final basin fill had been already removed in c. gori, but at pogi, near bucine, it released a rich fauna. downsection, a slice of the ascione unit is underlain by the terranuova silt of several meters thickness; the full profile is reconstructed for nearly 40 m, almost half with terranuova silts and half with ascione clays but either one covered by a few meters and with a relevant displacement in the mid section. the upper lithologic profile fits that obtained in the reduced sequence shown by the side of the magnetic stratigraphy in c. minuto (see fig. 17). the latter is very similar to the uppermost sequence of c. gori, although with minor changes in thicknesses, due to the irregular fluvial deposition. the gravel bank at the base is of comparable thickness, but the clay silt overlying it and containing the elephant bones reported earlier are of reduced thickness due to the nearly complete absence of the uppermost level rich in organic matter. the widespread closure horizon is also present, with a thin bed of sand on top and the gravel, just exploited by the quarrying but still visible in the vineyards by the side. 44.. mmaaggnneettoocchhrroonnoollooggyy ooff tthhee ddeeppoossiittiioonnaall rreeccoorrdd the magnetostratigraphic dating of the upper valdarno sequence was first applied to calibrate single sites with known position of fossil finds, either belonging to actual recoveries (torre et al., 1993; albianelli et al., 1997; 2002a; napoleone et al., 2001b) or to the museum old collections reappraised from the information in the automated catalogue (cioppi & napoleone, 2001; napoleone et al., 2001a). a thoroughly revised dating of the main museum collections is reported in a paper submitted in january 2001 to the bulletin of the italian paleontological society and still unpublished (napoleone et al., 2001c). these localities were placed in the new magnetostratigraphical asset, which was by the way still devoid of several results recently acquired and only now reported herein, while fresh outcrops let to better sample new sites with better behaved magnetic properties. one such sites was the poggio rosso profile, where even the more sandy samples of the series led to measure the acquisition of magnetization under strong applied fields as shown in the next section. the 142 g. napoleone et al. figure 11 the short sequence of the third depositional cycle is shown in the outcrop of the cava gori sand pit during the excavations for recovering the old water well of roman age. the full sequence is represented in the profile by the lithologies surveyed in the walls of the pit and its outskirts. the base of the profile is formed by the ascione clay of the underlying montevarchi series, which was surveyed for almost 40 meters in a partly covered outcrop in continuity with the present section (after albianelli et al., unpublished data). faunal site of matassino, in the same profile, was the prominent locality re-placed once the channelled nature of the previous section measurement produced the misleading value of its age previously reported (torre et al., 1993). finally, the filling series was investigated thouroughly and its late matuyama age is the newest result. this leads to an important role in the history of the growth of the appenine range that will be plaid by the complete range of dates now recorded, the longest series in the continental deposits of the apennines. last but not least, all recent data were made possible by the new recognition in the sedimentary sequence of the unconformity between the san donato and rena bianca sands which permitted to place the gauss/matuyama boundary in the basal rena bianca and identify in the overlying silts the short reunion chron (fig 2). the tabulated data from the measurements yielded the results here illustrated in a few figures by some representative diagrams, in order to focus the main aspects in the rock-magnetic properties associated with the upper valdarno lithologies, which provided the fundamentals for its magnetostratigraphy. 44..11 mmaaggnneettiicc pprrooppeerrttiieess ooff tthhee rroocckk ttyyppeess the problem of stability of the magnetic signal is of major concern in studying sedimentary sequences of rapid accumulation, as experienced in the present deposits on continental slopes, for the bacterial activities which reduce the iron oxides to sulphides. these can be very unstable under laboratory tests, by either changing with temperature into another mineral phase (magnetite) or being incapable of maintaining a regular track of their natural remanent magnetization (nrm) under applied fields with alternative currents (af). such a behavior was shown by the most representative early pliocene rock type of marine facies, in southern sicily, and by the lacustrine clay very rich in organic matter, close to the lignite seam at santa barbara (albianelli, 1995). these occurrences are enhanced by the following three main precedures. saturation of the isothermal remanence (irm), nrm stepwise demagnetization and the curie balance curves are among the more usual ones used for evidencing the basic rock-magnetic properties. with the first type of experiments, the degree of irm acquired along the three axes is shown by its demagnetization curves, which remark the low coercivity of ferromagnetic minerals. in the second one, visualised in zijderveld’s vectorial plots, the trend of the directions converging to the origin of the axes, while demagnetizing the rock sample, are indicative of a stable primary magnetization, not influenced by the secondary ones. with the curie-balance experiment, the acquisition of the remanence by a rock sample is enhanced while it is cooling in a strong applied field after its complete demagnetization with stepwise increasing temperatures. these tests were applied to the surveyed sections, and their lithologies showed a variety of different behaviors. sometimes such changes assumed a wider range within the same sequence rather than between the three main depositional series. depending on minor changes in the mineralogical content of their ferromagnetic particles, and related alterations suffered during their geologic past, the main types will be shortly illustrated in some examples for their good rock-magnetic properties on which the magnetostratigraphic interpretations are based. 4.1.1 meleto clay in the castelnuovo cycle as for all the other units, the basic lithology formed by silt is varying in a wide range of more sandy compositions: the stage of a complete sand bed is reached with marked discontinuities within the meleto clay. the most common representative of the rock type is here shown for only some of the measured characters. for example, in two samples of the meleto clay, different sulphide content can be demonstrated in beds overlying the lignite seam, one (sb -12) less than 5 m above its top and one (sb 27) 44 m higher up (fig. 12). the magnetic remanence is steadily decreasing versus temperature, to ca. 300÷400 °c, above which a remanence is added by new-formed minerals, essentially magnetite. the occurrence of sulphur compounds is common in marine and continental sediments of recent geologic ages and of rapid accumulation, depending on the redox conditions at the bottom surfaces where anoxic conditions lead the bacterial activity to reduce iron oxides of the magnetic minerals. this behavior was particularly diffused in the marine carbonates of the early pliocene sequence in southern italy, which showed a very unstable behavior and the diagrams for the curie-balance experiments enhanced peaks even more prominent than the ones here reported (albianelli, 1995). also the nrm reveals the presence of such perturbations in the rock composition, and is evidenced in the zijderveld plot where the directions are projected in the vertical plane z (inclination) and in the horizontal one h (declination), for every step of the demagnetization procedures. a onecomponent primary magnetization would show a straightforward trend to the axis origin, while perturbations at various demagnetization steps would enhance additional vectors which are being removed. the presence of a new magnetic phase, as in the previous example, would make the directions completely out of the steady demagnetization pattern: for this reason the values for a sample (sb -1) 11 m above the previous one (sb -12), are not plotted for temperatures higher than 300 °c, as the direction is suddenly diverging 143calibration of the upper val d’arno basin ... figure 12 diagram of the curie balance measurements carried out on two samples of the meleto, one (sb -12) from a level very close to the top of the lignite seam and another one (sb 27) some 40 m higher up. their magnetizations are decreasing at increasing temperatures, until a rapidly increasing value is measured around a critical range of 300÷350 °c, interpreted as a new magnetic mineral phase produced by oxidation of the sulphide contained in the rock. this content is markedly higher in the levels closer to the organic material, strongly decreases at 40 m level, and is absent farther up in the series. and the susceptibility sharply increasing. in contrast, the level bed at 46 m (sb 29) is devoid of these alterations. the latter type of diagram is available for every sample, as in all of them a number of demagnetization steps were used in order to control more accurately the changes measured, up to the highest step before alterations could interfere with the normal trend, or to the lowest magnetic moment detectable. the latter was that of the magnetometer of the eth paleomagnetic laboratory in zurich, and the measured signal provided fully reliable intensities for magnetizations in the range of 10-8 uem/gr. 4.1.2 the montevarchi units the few levels with fine-grained limy beds in the coarse grain unit of san donato sand and finer sand in the rena bianca usually enhance low nrms, which rapidly decay to undetectable values not further than 300 °c. in the overlying montevarchi sediments the general characters of the rock magnetic behavior are similar to the meleto types, with a more common occurrence of oxidized material of higher coercivity, able to reach higher blocking temperatures in samples with higher silt and sand contents. the experiment for irm saturation in the orthogonal directions, with its demagnetization, adds one more evidence of different behaviors of the carriers of the magnetization. two examples of this test are also shown (fig. 13). for each of them, two diagrams show the acquisition of the magnetization and its differential removal, to represent the behavior of a clay (gt 13) in contrast with a silt (f 48). in the first two diagrams on the left, the magnetization rapidly increases, in the range from 50 mt to 200 mt of an applied field up to 1 tesla (t). the upper sample represents the saturation for the low coercivity minerals, which is normally attained in that range; the lower sample represents those of high coercivity, which do not reach the saturation, requiring stronger fields (usually up to 5 t, or more). on the adjacent two diagrams , the three components of the magnetizations acquired show their decay curves, which are in the great majority of the measured samples showing low blocking temperatures for minerals with low coercivities. in sample gt 13, the component acquired up to 100 mt contains the total amount of the magnetization and practically nothing is left to the other two. the only one blocking temperature is interpreted to be that of magnetite as the sole carrier of the magnetization. the opposite occurs in sample f 48, with a first branch of the diagram relative to a low coercivity mineral phase, and a superimposed one not reaching the saturation up to 1 t. the minor phase showing a low blocking temperature is likely associable to other ferromagnetic minerals including sulphides; another one not yet destroyed at 600 °c, is interpreted as hematite. the same properties are evidenced by the related demagnetization curves of nrm, on the right hand diagrams, for two samples, one at the same level gt 13, and the other, f 45, with the same lithology as f 48. another example (fig. 14) shows two samples from the level beds close to the poggio rosso fossil site, whose nrm is demagnetized by thermal treatment and by alternative fields af. the fairly straight pattern of the af curve in also an indication of the absence of sulfides, whose instability produces random directions 144 g. napoleone et al. figure 13 an example of the irm saturation for two samples from the tasso section (gt 13) and faella section (f 48); their remanence acquired on the three axes is thermally demagnetisedin order to show the blocking temperature of the minerals associable to different coercivity ranges. the next two diagrams on the rigth show the nrm demagnetization for two similar samples, plotted in the zijderveld polar diagrams. 145calibration of the upper val d’arno basin ... figure 14 at poggio rosso, in the series of the second sedimentary cycle, the demagnetization of the nrm is shown by applying either the thermal treatment to a sample of sandy silt shortly above the fossil site, or that of the alternative fields af applied up to 160 mt. both treatments destroy stepwise their remanences, in order to enhance any superimposed field fixed after the primary one, which is well preserved in the original directions. during successive demagnetization steps. 4.1.3 the uppermost units the final deposits of the upper valdarno, exposed at the cava gori, are represented by a sample of the uppermost silty clay (cgn 14), which is compared with a reversed one from the unconformably underlying unit of the montevarchi sequence (fig. 15). both levels are made of the same material, although their dates are nearly 1 my apart, as shown in the next section. the silt is in both cases more clayey and peaty, and the samples are taken from very fresh outcrops. the reversed one, cgv 33, shows the removal of a weak component with normal magnetization, usually due to the present normal polarity acting for the recent geologic past, which is rapidly cancelled in the initial demagnetization steps. both sand levels and the thin beds of fine sediment in the lower half of the cava gori profile (fig. 11) revealed poor rock-magnetic properties, with their nrms very weak and demagnetization curves of rather unstable directions, indicative of a transitional field, which was instead better recorded in cava minuto with a decise reversal (fig. 17). 44..22 mmaaggnneettoossttrraattiiggrraapphhyy iinn tthhee rreeffeerreennccee sseeccttiioonnss the sedimentary reconstruction of the basin is now being completed, and it led to the selection of the sections for the paleomagnetic surveys, on both sides of the arno bank. on the left bank, the first cycle of sediments is displaced by a significant lowering on its eastern flank so that it is exposed only in the western bank, from the gravel and clay underlying the lignite seam to the meleto clay, and up to the rena bianca. the dates there measured mark the steps from 3.3 ma to 3.1 ma, up to 2.1 ma, respectively. the full sequence of the second lake is represented on the right bank of the arno river by generally flat beds, except the lowermost ones which are not exposed; it spans from nearly 2.1 ma to 1.7 ma and covers almost completely the montevarchi series. in the left bank, this sequence is partial, interrupted for long intervals and dipping 15°÷20° to the nne. the unconformity cuts there nearly half of the montevarchi sequence, as the basal gravel of the third cycle directly overlies the ascione unit, while the lower series of the terranuova silt is present only with its upper portion. the third cycle has been surveyed in two outcrops on the right bank and two on the left bank, all in quarries exploiting gravel and sand. its basal gravel yielded on both sides reversely magnetized levels in the few limy figure 15 in the sediments of the third cycle, at the cava gori sand pit, a sample with reversed magnetization is thermally demagnetized, in the same way as the previous samples, and is compared with a sample of normal magnetization collected in the underlying outcrop belonging to the ascione unit. beds, but followed by the normally magnetized ones in the silty sequence of the western bank. 4.2.1 dates from 3.3 ma to 2.1 ma, santa barbara and rena bianca sections the gravel in the earliest sediments is devoid of measurable levels, except for few thin silty beds with reversed polarity. the few-meters clay level above it was no longer exposed at the time of the paleomagnetic survey, and the section for magnetic stratigraphy was sampled in the outcrop starting above the lignite-bearing clay directly lying on the basement. it was later completed downwards by cores drilled in two bore-holes, less than 100 m away from the outcrop, towards the inner lake, where the lignite seam is followed downcore by a few meter thick clay level overlying the sandstone basement. a normal polarity is measured in the lower core, and a reversed one in the higher clay and in part of the lignite, while further up the rest of the lignite and the clay yield again a normal polarity. this persists until the end of the section. its magnetic stratigraphy is interpreted as the latest gauss normal polarity following the kaena reversed one (albianelli et al., 1997). above the lignite-bearing level, the series continues some 400 ky in the meleto clay (albianelli, 1995). in fact, from the magnetostratigraphic constraint of the kaena boundary the duration of the sequence was calculated by spectral analysis of the magnetic record, which marked its continuous changes in the milankovitch index-forced sedimentation, to last 60 ky before the end of the gauss chron. the cyclicity-driven changes are discussed elsewhere (napoleone & albianelli, 2002), and they also date the onset of the alternating vegetational associations of warmer and cooler climatic intervals, starting in the mid pliocene and preceding the ice-rafting of the glacial-pliocene (shackleton et al., 1984; demenocal & bloemendal, 1995). the overlying sand unit (san donato sand) is not in continuity with the profile of figure 3, and yields a normal polarity in the few measurable silt levels. further up, two levels with a normal and reversed polarity are measured and labeled as marking a short interval containing the gauss-matuyama boundary. this latter was felt to be positioned only when the cyclostratigraphic processing of the magnetic signal through the time series of the meleto clay yielded the full extent of the latest gauss, except the last 60 ky before the boundary. these results were reported in several meetings, from the ias of 1998 to the gsa of 1999, the euromam in 2000, and on the sepm integrated cyclostratigraphy in, 2001, for which the final study is in the press (napoleone & albianelli, 2002). in the wind-blown sand complex above the san 146 g. napoleone et al. figure 16 the magnetostratigraphic profile of the faella clay pit, valid for the whole montevarchi series. the lower portion is provided by the faella section, and the upper part, by the tasso tunnel section,. the lithologic profile is that of cava faella, to wich the positions of the museum collection of the faella local fauna are associated. thus, the localities of the montevarchi series are calibrated to the faella composite magnetostratigraphy and the vrica stratotype is reported for reference. donato sand, few levels were useful for sampling. the final figure is still under discussion, but the results support the occurrence of a short reunion chron, just above the end of the rena bianca sand and in the following montevarchi succession. this updated version is reported here (fig. 2), and a more detailed profile is reproduced in figure 18. 4.2.2 the interval 2.1 to 1.7 ma in the faella section after the reunion, recorded above the condensed series of wind-blown sand, the sedimentary history and its continuity with the overlying sequence in the matuyama has not yet been fully recognized. in the western bank, the rena bianca is overlain by the terranuova silt for a few meters; in the eastern bank the terranuova silt extends over a thickness of several tens of meters, but the contact with the underlying unit has never been uncovered. this disconformity has an estimated duration of less than 100 ky, after the magnetostratigraphic reconstructions made so far on the outcropping sections, while more data from a bore-hole core extend the series few ky earlier in the reversed magnetozone (albianelli & napoleone, unpublished data). in fact, the earliest fossil is dated 1.99 ma at faella while the terranuova silt extends at least 20 m below it in the outcrops, and possibly 20 more meters, as cored in the bore-hole drillings at terranuova. this sequence, at the rates of deposition calculated by albianelli et al. (2002a) and discussed in napoleone and albianelli (2002), would add ca. 100 ky, and therefore the earliest date be extended to 2.1 ma. from the bottom, the identification of the reunion leads to a date of 2.24 ma (in the time scale of baksi, 1993) as a lowermost limit, with some more space available to shorten this 150 ky gap, which becomes much shorter with the date of 2.14 ma used in the scale of berggren et al. (1995). the geological setting of the montevarchi complex indicates a wide distribution of its three units, which are exposed frequently by quarrying operations. a nearly complete magnetostratigraphic succession is reconstructed on the right-hand bank. from the missing contact with the rena bianca sand, its lowermost exposures are at the arno level, and not in continuity. they are overlain by the faella section, the longest and most continuous one, forming the profile for the central lake sequence (fig 18). in the western bank, the montevarchi beds are interfingered with the upper levels of the aeolian sand younger than the reunion, therefore not reaching a date of 2.14 ma. also the upper limit is not calibrated, the youngest date being measured in the eastern bank shortly after 1.77 ma, in the oreno sand; some more 50 ky may be expected in the last 20÷30 m of the highest sequences, considering the sedimentation rate calculated by spectral analysis of the continuous magnetic record (napoleone & albianelli, 2002) and the average rates shown by the detailed magnetic stratigraphy (albianelli et al., 2002a). therefore a date not younger than 1.70 ma would be reached. significant geochronologic results relate to this interval. downsection from the base of the olduvai at 1.95 ma, the earliest fossil occurrence dates 1.99 ma, with the new recovery in january 2000. the top of the profile did not yield any positioned fossil site and also the end of the olduvai was better defined in the tasso tunnel section. therefore, the magnetostratigraphic section is produced from the composition of the two (fig. 16), and adapted to the profile shown in figure 18. the entire sequence also provides the base for correlating several profiles surveyed in the montevarchi units, usually with an accuracy within 5 ky. the most important one is the matassino section where the base of the olduvai was first identified (torre et al., 1993). for its geochronologic implications, see the discussion in napoleone et al. (2001b). the section of monte al pero, adjacent to the matassino section, was surveyed from top to 20 m above the ground-level of the matassino clay pit; only one normal polarity was measured, as occurred also with the normal polarity in the poggio rosso section. both sequences were correlated with the faella section (fig. 16). more implications arise after the new results from several cores drilled in the upper sequence and at its base, thus extending the magnetostratigraphic profi le, downward in the terranuova silt and upward in the oreno sand, but details on these data will be reported elsewhere (napoleone et al., in preparation). the preliminary results extend only by a few meters the lower profile in the reverse polarity, but they produce important implications in the upper profile because a normal polarity is measured for several meters on top of the sequence. this part is recognized in the latereto sand of the upper series, discussed in the next section. the total time span of the measured series ranges from nearly 2.05 ma to 1.75 ma, while an estimate for 147calibration of the upper val d’arno basin ... figure 17 at cava minuto, 1 km away from cava gori, the sediments of the third cycle are represented by a less complete sequence, but in the basal gravel two lenses of silty clay are better developed than in the c. gori and their magnetization is with a reversed polarity. above the gravel unit the polarity is normal as in c. gori (after napoleone et al., unpublished data). the remaining parts not yet found in the exposures would add some 50 ky to both extremes. 4.2.3 the upper series at cava gori and c. minuto the sedimentary cycle above the montevarchi succession started again without any striking gap recorded by sedimentary or tectonic discontinuity. the faunal record was totally lacking in the eastern bank, except one frontal skull of a bovid, while on the western bank the faunal record occurred only in the uppermost filling, on the surface. on the right-hand side a reversed polarity was measured at cava specchiano, and a normal one on the opposite bank, at cava gori in the monteleone area. the first magnetic polarity dating is from the fine grained levels in a less than 10 m thick gravel deposit. it stands as an isolated reversely magnetized interval in the matuyama, and a date for it was questionable; a moderately young matuyama date was only reported as tentative (albianelli, 1995; cioppi & napoleone, 2001). in the cava gori profile, which also unconformably overlies parts of the montevarchi series, the normal polarity measured in the sand just above the gravel, correlative with that of c. specchiano and farther up in the latereto silt, may imply a post-matuyama chron (albianelli & napoleone, unpublished data). at present, this reversed matuyama level is considered to shortly precede the jaramillo or brunhes chrons. it would imply that a lack of nearly 0.7 my or 1 my, respectively, affected the sedimentary record, beginning soon after the end of the olduvai. the sequence is there tilted by 17°, and the magnetic stratigraphy of the profile reported in figure 11, is used to reconstruct the comprehensive upper valdarno series (fig. 18). an important date is added here by new results (napoleone & albianelli, unpublished data) from the analogous section at cava minuto (fig. 17). this profile is a little shorter than at c. gori, its lower sand level being actually missing; the basal gravel on the contrary contains two episodes of fine grained silt, which both yield a very stable reversed magnetization; above the gravel, the silt containing the fossil site and the remaining sequence show a normal polarity. this sharp time signal can be represented as in figure 18 and its date should correspond to a postolduvaian polarity change, which can only be the jaramillo or brunhes chrons. in such conditions the choice of any one of them cannot be solved because the basin fill is devoid of any further step; on the other hand, the previous results provide a fundamental date to reconstruct the history of the basin. the long time span implied in the previous considerations, during which no sedimentary record was preserved, ought to be recognized in the geological processes taking place in the basin and recorded in some way. 44..33 tthhee ssuummmmaarriisseedd mmaaggnneettiicc ppoollaarriittyy sseeqquueennccee a new magnetochronology has been brought about by the results discussed so far in this chapter and its comprehensive features better enhance several details (fig. 18). magnetostratigraphy of the thick first sequence interval yielded a date of ca. 3.3 ma (at the mammoth chron, c2an.2r) for the basal spedalino gravel and pebbly sand, and ca. 3.1 ma for the lignite seam, which began depositing shortly before the kaena (c2an.1r). the succeeding clay sediments attained a variable thickness (100÷200 m), and their layers became progressively more closely interbedded with sand levels while approaching the gauss-matuyama boundary. the sequence was calculated to end at 2.64 ma, shortly before that boundary (2.58 ma), while the record of the short reunion chron c2r.1n (2.15 ma) has now 148 g. napoleone et al. figure 18 the complete reconstruction of the lacustrine sediments is represented in the lithologic profiles from both sides of the arno river bank. the first lake is represented only by the long sequence outcropping in the western bank; in the eastern side the exposures begin with the second lake, and are well developed. correlation with the western bank is marked by the occurrence of the olduvai chron and its underlying matuyama; the former is interrupted in the ascione clay unit, while the short polarity sequence above the unconformity is dated to the jaramillo chron (or later, to the brunhes). its equivalent in the eastern bank has not been measured in the central area, and has yielded only one reversed polarity in the southern area, at specchiano. the olduvai and correlated with the deposits retrieved in 1862 by cocchi (1867), as emphasized in napoleone et al. (2001c). these represent the earliest fossil finds, over 1 my younger than the fossils from the preceding castelnuovo succession. the biochronologically youngest fauna of tasso, elevated to the rank of reference unit (azzaroli, 1977a; 1983), is believed to come from the upper levels. it is assembled by all unpositioned specimens from the old collections; only one site was reported by bosco (quoted in azzaroli, 1998) for two porcupine skulls at le strette, 183 m in elevation. nearly the entire series of montevarchi is now assigned by the magnetostratigraphic reconstruction to a late pliocene age (albianelli et al., 2002a); while the boundary of the pleistocene is calibrated in the oreno unit, at 195 m of the faella composite section (fig. 17). the latest fauna, at the very end of the basin fill provided the greatest new results, i.e. a date for it is firstly reported herein. it is fixed at 1.0 ma and replaces the previous age of late middle pleistocene by precise stratigraphical constraints for reconsidering the whole biochronologic history of the basin and its palaeoenvironmental reconstructions. 55..11 tthhee eeaarrllyy vviill llaaffrraanncchhiiaann ffaauunnaa mmnn1166aa aatt tthhee kkaaeennaa//llaattee ggaauussss bboouunnddaarryy ooff 33..1111 mmaa the fossil finds assembled in the castelnuovo dei sabbioni fauna (mn16a) were collected only in the lignite-bearing level, whose base is older than the beginning of the kaena chron (ca2n.1r), at 3.11 ma, and in the clay beds interfingered with the top of the lignite, at 3.04 ma. a date shortly earlier than this boundary may be assigned, 3.07 ma, with an uncertainty even better than ± 0.02 my, considering that the lignite seam could represent a rather short-lived event in the sedimentary record (fig. 2). its time span may be reconstructed by the magnetic cyclostratigraphy carried out on the meleto clay series (albianelli et al., 1999; napoleone & albianelli, 2002). the clay above the lignite-bearing level yielded an accumulation rate of 220 mm/ky, progressively increasing, up to 390 mm/ky on top; at that lower rate, a 15 m thick lignite bed would last 2/3 of 100 ky, and a rate only twice higher than that one for the clay would lead to the mentioned size of ± 0.02 my in the error bar on a date close to 3.11 ma. it is also reminded that the early villafranchian record of the castelnuovo fauna was classified as contemporary with the triversa faunal unit from villafranca d'asti and the latter will be described in the next chapter. the calibration of the castelnuovo fauna puts a tight constraint on the faunas of triversa and arondelli in piemonte, the latter correlating with the other one in the lower valdarno provisionally taken as an undefined lmf assemblage, but dated quite younger than triversa (to be discussed in next chapter 6). 55..22 mmiidd vviillllaaffrraanncchhiiaann:: tthhee mmaassttooddoonntt iinn tthhee eeaarrllyy mmaattuuyyaammaa,, 22..5588--22..1155 mmaa faunas of this age are labeled in the mammal classification as mn16b. its reference faunal unit was the montopoli association, not represented by an equivalent local fauna in the upper valdarno record, but highly significant for the major turnover it marked in the 149calibration of the upper val d’arno basin ... been found shortly above the rena bianca sand in one of its few exposures. the following matuyama time is recorded in the lower montevarchi silt, and the olduvai in the overlying units. the late olduvai however recorded an important event in the split polarity reversal, which is dated 1.815 ma and 1.785 ma in the p/p stratotype boundary (1.796 ma), before the end of the chron at 1.77 ma. the latest sediments are not calibrated by a polarity sequence, due to the short length of profiles, and the date near 1.05 ma reported above is alternative to the one at 0.78 ma. the lithoand magnetostratigraphic profiles are summarized in the two reconstructions made from the opposite banks of the arno (fig 18), while the previous magnetostratigraphic framework was reported for convenience in the introduction (fig. 2). the discussion on the dates for each faunal interval, for the ca. 2.5 my surveyed in the basin will follow below, while the results from cyclostratigraphy, reported in the references quoted above, mainly relate to the climate and sedimentary changes for these critical ages of the recent geological time. 55.. ddaatteess ffoorr tthhee uuppppeerr vvaallddaarrnnoo ffoossssiill vveerrtteebbrraatteess most events of the villafranchian age were recorded in this basin, and the dating of its sediments is related to calibration of the middle and late pliocene and beginning of pleistocene. correlation with the bio-chronostratigraphy is updated to the revised one of berggren et al. (1995), and calibration of the pleistocene boundary is related to that of the vrica stratotype (van couvering, 1997). an attempt at uniforming various stages of vertebrate associations in the mammal neogene (mn) age classification assigned the villafranchian to the relative ages mn16 and mn17 (mein, 1990). for the aforesaid reasons, azzaroli (1995) split the mn16 in mn16a for the early villafranchian and mn16b for the middle villafranchian, pointing out that the major faunal turnover occur between the triversa and montopoli fu at the late pliocene boundary (azzaroli, 1983). whereas the faunas of montopoli and olivola respectively of middle and late villafranchianwere collected outside of the upper valdarno, from single pockets with a rich concentration of bones and a variety of species, the early villafranchian fauna of castelnuovo was dispersed, even if the few species lived for a presumably short time span within/or across the lignite-bearing level. in contrast, the rich fossil-bearing montevarchi succession is widely distributed and tightly constrained by several magnetostratigraphic tie-points, after a long gap occupied by the condensed series, which has now been dated to range from the gauss-matuyama boundary at 2.58 ma to the reunion at 2.15 ma. the montevarchi sediments extend from the vicinity of incisa in the north-west to around bucine in the south-west, with a length of over 20 km, and fossils are distributed in horizontal deposits ranging from approximately 130 to 230 m in elevation. the fossil-bearing levels lie in either one of the ascione and oreno units overlying the terranuova silt, and in the latter as well. in the terranuova silt , in particular, the fossils collected from the basal faella clay pit at 134 m are calibrated before biodiversification of the terrestrial fauna in western europe and southern russia (azzaroli, 1983; 2001). with the magnetostratigraphic calibration, it is established that during the mid villafranchian age the upper valdarno record was mostly formed by subaerial deposits, for a more than 0.4 my time span (fig. 2) and in a well established regime of glacial-interglacial oscillations partly recorded by the pollen distribution. thin limy beds within these wind-blown sands have recently shown the end of the reversed polarity alternating with the normal one, which leads to the recognition of the presence of the reunion chron c2r.1n immediately above the transition to the silt of the following lower deposits (albanelli & napoleone, unpublished data). the only one finding of vertebrates, attributed by azzaroli to possibly belong to this sequence is a nearly complete skeleton of a mastodont found in the vicinity of the montecarlo convent, on the hilltop on the left bank of the montevarchi basin. the fossil was excavated in early eitghteen hundred and was summarily described, without an exact indication of the site, by filippo nesti in 1825, who did not report on the stratigraphy of the upper valdarno in that occasion. in 1811, in contrast, he gave precise indication for the location of the rhinoceros of poggio di monte al pero and of the geology of the montevarchi deposits (nesti, 1811). the anancus of figure 4 is from the castelnuovo sequence but considered somewhat younger than the castelnuovo dei sabbioni fauna, although its recovery was not reported and location is unknown. the montecarlo convent is built on deposits of the second cycle, but not far west the hill slopes down and overlies deposits of the rena bianca unit. the skeleton may safely be assumed to come from the latter formation. it is practically complete (only the tusks are missing; in the exibition of the museum they were replaced). the specimen is of a large size, nearly 3 m high at the withers. it slightly exceeds the size of a mastodont from valleandona in piemonte, west of asti, summarily described and figured by capellini (1908). to judge from the shape of its pelvis, it seems to belong to a female. this famous specimen in the paleontological collections of the museum of firenze was ascribed to the mid vil lafranchian, as it was last represented in the montopoli fauna. another specimen of anancus was reported in the marchesa paulucci collection, donated in the early 19 hundreds to the museum of firenze (cioppi et al., 2001); it consists of a tusk and a molar whose position is believed by azzaroli at the base of the hill on top of which her villa is positioned at sammezzano, on the right bank of the arno, in the middle of the area of the montevarchi terranes, but the fossil site cannot be better identified. 55..33 llaattee vviillllaaffrraanncchhiiaann:: ffaauunnaass ooff oolldduuvvaaii ttiimmee ddaatteedd 11..9999--11..7777 mmaa this mammal age is covered in the upper valdarno by the montevarchi sequence which is represented by the outcrops on the eastern bank of the arno forming the profile of the central lake (fig. 18). the whole sequence is particularly well documented by the detailed dates of its finds, but it is unfortunate that the majority of fossils of the older collections, ca. 75% of the upper valdarno vertebrates in the museum, do not bear an indication of the locality nor of the exact level of provenance. almost all of the series has been calibrated to the late pliocene age, and the dated fossil record spans 220 ky from 1.99 ma in the faella section, including the pleistocene boundary sited in the oreno unit. as said before, this section has recently provided the oldest specimens. out of faella, the matassino deposit represented until recently (gliozzi et al., 1997; torre et al., 2001) the first fauna of the late villafranchian, which had been classified as coeval with the olivola faunal unit for their affinities (azzaroli, 1977a). magnetic stratigraphy of the matassino section identified this locality to stand ca. 10 m above the base of the olduvai, and its date to be quite younger than 1.95 ma (torre et al., 1993). a new determination has been made in the summer of 2002, sampling a profile adjacent to the previous one and where parts of an elephant have been later collected. it shows that a 12 m thick normal polarity was brought in by channelled sand embedded in a reversed magnetozone (napoleone & albianelli, unpublished data). a further profile, sampled closely by the side of the channelled deposit, led to the reconstruction of the classical old locality as sited just at the base of the olduvai, and its date at 1.95 ma, replacing the previous profile which produced the misleading date of latest olduvai. in the same clay pit, the poggio rosso site is 30 m above the matassino site, and its fauna forming the richest assemblage collected in the upper valdarno is dated 1.87 ma. this value is the result of the cyclostratigraphic analysis of the magnetic signature (napoleone & albianelli, 2002) and of the correlation with the faella magnetostratigraphic section (napoleone et al., 2001b). to the se of the matassino hill, the rhinoceros studied by nesti in 1811 was collected near the top, at poggio di monte al pero and located shortly above the poggio rosso fauna: it was dated ca. 1.83 ma, being correlated with the faella reference section. the same date has been given the rhinoceros skeleton recovered in 1999, while the elephant collected by azzaroli in 1953 is estimated to be slightly older, 1.87 ma (azzaroli & napoleone, in manuscript). the old collection of faella is centered at a level higher than the latter site and a younger date was assigned to this part of the faella lmf, at 1.82 ma, while the elefant of 1949 would be even younger. the large tusk collected on the road to siena, west of montevarchi, was excavated in the upper oreno sand and represents the youngest dated specimen of the montevarchi series (fig. 16); it is labeled as azzaroli’s elephant only for graphic covenience. several other large collections do not have a magnetic stratigraphy, or their sites are not positioned. however, from the previous results some inferences restrict their dates to a narrow range of uncertainty. first of all, the casa frata fauna was collected near the section of the tasso tunnel, in the upper ascione beds close to the transition to the oreno sand, which in that profile is in the portion of the olduvai ending at 1.815 ma. the casa frata fauna is therefore placed in figure 16 quite older than this date and likely close to 1.85 ma. the problem with the tasso faunal unit is similar. few detailed indications were given only on the porcupine of bosco (azzaroli, 1998), referred as positioned at le strette al tasso, an area around the small water gap 150 g. napoleone et al. of the tasso creek, where the farm labeled as le strette on the official map of the national topographic survey is reported at 183 m. as a consequence, the biochronologic constraint that the tasso faunal unit (to which this porcupine belongs) follows the poggio rosso and casa frata faunas imposes that all specimens of the assemblage should have been recovered in level beds quite higher in the series and not in the lower oreno unit still datable in the late olduvai. although not fully calibrated, the oreno sand would not reach the date of 1.70 ma: at most, the tasso faunal unit, sited in the short interval of the oreno sand would be dated from shortly before the p/p boundary to shortly later, for example between 1.8 ma and 1.75 ma. in figure 20 its position is stretched towards this upper limit. the totality of the fauna dated so far did not range beyond the late pliocene; only a minor part, before its calibration, is expected to actually be of early pleistocene age, and lasted very few ky. also another proxy is in the same condition, the pollen record, which does not reach the pleistocene boundary, as reported elsewhere (albianelli et al., submitted). at very few ky before the boundary the pollen record attains the highest percentage of herb sporomorphs, indicating a steppe vegetation of glacial facies. deposition becomes more sandy and its rate close to that of the san donato sand. all fossils from this succession were assigned a wide range of dates in the early pleistocene, and with this age are reported in the gef automated catalogue (cioppi et al., 1996). no site has been measured yet in the pleistocene, as it is located in the p/p stratotype (van couvering, 1997). therefore one might argue that early pleistocene representatives are barely present in the palustrine sequence of the upper valdarno, considering that the two skulls of hystrix etrusca, from le strette, se of terranuova, were found in a site which lies near the unfossiliferous wall opened for the tasso tunnel. in this section the end of the olduvai chron was measured at 205 m level and the pleistocene boundary placed at 195 m (figs.10, 16). the remaining fauna from the undefined localities of the tasso mammal unit might be considered in a similar condition. it was never fully studied from the palaeontological point of view, and none of its specimens was sited precisely in the several findings from the tasso localities, le strette al tasso, il tasso, ville al tasso, etc. these all belong to the upper montevarchi series, but a stratigraphic resolution better than ± 20 m would add a slightly more precise age of no more than 50 ky around the end of the olduvai at 1.77 ma, except to slip back and forth across the pleistocene boundary. 55..44 tthhee ppoosstt--vviillllaaffrraanncchhiiaann ooff bbuucciinnee aatt tthhee jjaarraammiilllloo bboouunnddaarryy,, 11..0055 mmaa the rich faunal assemblage collected on the surface in several sites of the pogi area near the town of bucine, belongs to the gravel of the latest filling of the basin, best represented by the cava gori lithologic profile. the magnetostratigraphic profile of the adjacent cava minuto gives, instead, a prime result for the history of the upper valdarno: the lower portion, in the reversed magnetozone, puts the lower limit of the basin fill not younger than the transition from villafranchian to the galerian mammal age. in the meantime, the fossil site of cava minuto would summarize the thin horizon of the bucine fauna and yield a date of the onset of the normal polarity interval. however, its range would be very narrow, as the recoveries at pogi had been in the upper gravel, no more exploited, but in the same horizon which closes the basin fill at cava minuto, and just following in the normal polarity the elephant bed. therefore, a younger limit could reach the date of 0.78 ma, to which the beginning of the middle pleistocene is calibrated to the gpts, and an older one would be dated shortly more than 1 ma. a date very close to 1 ma or to 0.8 ma would be provided for both, the fossil collected at cava minuto and the ones at pogi. these dates build a completely new framework for the history of the basin, which now is more clearly understood also in relation to the other northern apennine basins. the calibrated faunas there recovered (see in the next chapter) do not exceed a date younger than the brunhes boundary and more likely jaramillo. only the bucine lmf would have reached an age as young as a late middle pleistocene, which has to be rejected in absence of stratigraphical supports, while the present magnetochronologic framework puts immediately the constraints on the age of the elephas antiquus recovered in october 2001. 66.. cchhrroonnoossttrraattiiggrraapphhiicc ffrraammeewwoorrkk ffoorr tteerrrreessttrriiaall ffaauunnaass ooff tthhee iittaalliiaann ppeenniinnssuullaa the time span elapsed for the deposition of the upper valdarno sediments, during the villafranchian mammal age, is now calibrated by magnetic stratigraphy to the middle and late pliocene, and to the earliest pleistocene. these accurate dates are applied to date the fossil sites and the palaeoenvironmental changes which affected the apennine basins. for these ages, in fact, the faunas of the main localities of the italian peninsula, recently reconsidered by azzaroli (2001), are now recognized in stratigraphic order. their distribution is mainly located in the northern apennines (fig. 19), and correlation is made with the same criteria as for the biostratigraphical series, so that the previously established biochronologic dating can be now formulated on the base of the gpts dates, with a decidedly improved accuracy (fig. 20). this chronostratigraphic asset of the faunal events is also valid for the main events of the global climatic changes, which were recorded in the apennine continental sediments using the magnetic signal for processing the spectral distribution of its changes, and detecting the oscillations of the pollen percentage affecting vegetational assemblages of cooler and warmer climates. both proxies were investigated in parallel over three sequences, whose time series were constrained by a direct magnetostratigraphic zonation. in the upper valdarno, the interval 3.1÷2.64 ma showed the shift from the precessional to the obliquity cyclicity at 2.85 ma; in the valtiberina, the interval 2.8÷2.1 ma showed the same shift, but shortly later; in the san arcangelo basin of southern apennines, dated shortly before the jaramillo, the eccentricity cycle period was already established along with that of obliquity (albianelli et al., unpublished data). climatic changes in the geological system were inferred from palaeotemperature oscillations in the oceanic waters (shackleton, 1995). they consist of fre151calibration of the upper val d’arno basin ... quent fluctuations, at a rhythm of approximately 40 ky, which took place after a steady decline to cooler temperatures occurring between 3.1 ma and 2.5 ma. the 40 ky signal dominated until ca. 1.0 ma, and was followed by a marked change in amplitude and frequency with a shift to fluctuations of 100 ky and to a further decline in temperature involving major climatic changes on the continents. a marked change of climate in china was shown by deng et al. (1999) to coincide with the beginning of loess deposition, at about 2.6 ma. also magnetic stratigraphy enhanced in the loess deposits the onset of an alternating signal during wet and dry conditions with alternations of paleosols producing distinctive magnetic characters (heller et al., 1991; spassov et al., 2001). in western europe a direct influence of the climatic changes on the vegetation was evidenced by the pollen distribution with drastic changes during the late pliocene and pleistocene (zagwijn, 1974; suc et al., 1995). in the vrica stratotype area, the series yielded a pollen record representative of the central mediterranean realm (combourieu-nebout, 1993; combourieu-nebout & vergnaud-grazzini, 1991). in the northern apennines such changes were searched in the upper valdarno, where details in the vegetational associations were dated since 3.1 ma with the stratigraphic resolution of the gpts. the subtropical forest of warm-temperate climate, already established since the early pliocene, was still steadily persisting in the mid pliocene meleto clay, and gradually replaced by a conifer vegetation of cooler climate (bertini, 1994), beginning in the middle of late gauss, at 2.85 ma. this date was focused by a marked change in the spectral content of the magnetic susceptibility profile, with the amplitide of the dominant cycle at 20 ky period of the precessional index in the early pliocene drifting to the 40 ky period of the obliquity (albianelli et al., 1999; napoleone & albianelli, 2002). a similar drift was recorded by the magnetic signal in the deposits produced by the climatic changes in the subtropical africa (demenocal & bloemendal, 1995). the measured periods of the cycles were in the range of the milankovitch changes of the astronomical parameters affecting the solar radiation. it may be assumed that temperature changes in the boreal hemisphere were triggered by the insolation, and that deep ocean sediments reflected with a definite lag events which had taken place on the surface of the earth. the lag, from the observations on continental faunas and loess deposition, was possibly of the order of 100 ky, or may be even larger according to pollen and magnetic records. the villafranchian terrestrial faunas of the apennine basins were deeply influenced by climate changes at the gauss/matuyama boundary when the pliocene ice-rafting took place (shackleton et al., 1984), and at the jaramil lo. in contrast, at the pliocene/pleistocene bondary their turnover was much less notable, as shown in the following faunal distribution, reconsidered after its magnetochronologic asset. the present paper discusses faunal events that took place in central and southern italy (fig. 19) during the period from nearly the onset of the late gauss, through reunion and jaramillo, up to the onset of brunhes, approximately from 3.1 ma to 0.8 ma. magnetostratigraphic calibrations made in the upper valdarno involved sequences not much younger than the end of olduvai (1.77 ma), thus not reaching 1.70 ma. then two short sections, at colle curti and cesi in the colfiorito basin and the one at oriolo in the littoral deposits of the external apennines (to be discussed at the end of this chapter), were respectively dated to the jaramillo and beginning of brunhes. most of the middle pleistocene is now being studied through one single section in the southern apennines, although with a poor faunal record. preliminary studies dated its base shortly prior to the jaramillo (sabato et al., 2002), and new detailed results extended the series into the brunhes (albianelli & napoleone, unpublished data). all the assemblages reported in the following sections will be assigned a position on the gpts, summarized in figure 20, to which a numerical date will correspond for calibration. as discussed before, the late villafranchian faunas of tasso and of the close farneta area are inferred to date in the proximity of the end olduvai, but their stratigraphic position is still drawn at a younger age, so partly maintaining the biochronologic setting. their range of uncertainty is visibly wide, at the scale of the gpts geochronology, but the faunas lacking a direct magnetostratigraphic calibration are positioned with dates in the most appropriate approximation inferred from what reported below. some faunas discussed in the next sections but not shown in figure 20 can be accordingly located with the same cautions used for the accuracy of their numerical dates, which anyhow can benefit from an improved accuracy by the new position of the faunal units, displayed in the last column on the right-hand side. 66..11 tthhee ddeeppoossiittss ooff eeaarrllyy vviillllaaffrraanncchhiiaann aaggee the earliest continental sedimentation of the apennine basins is the one of the upper valdarno, as it is enhanced by magnetostratigraphy, and marked to occur in the second half of the gauss chron, to which a middle pliocene age is correlated. the earliest deposit 152 g. napoleone et al. figure 19 – map of the main sites of faunal distribution in peninsular italy. the earliest fauna, out of the triversa site located in the western corner of the po valley and north of the area here represented, was believed to lay in the area of aulla underneath the olivola site. a general trend of more evolved faunas was recognized, moving from west towards the more easterly basins. the present magnetostratigraphic dates are reported in chapter 6 for the sites here labeled: 1, olivola; 2, mugello; 3, montopoli; 4, firenze; 5, upper valdarno, in its bulk; 6, farneta; 7, selvella; 8, pietrafitta; 9, colfiorito; 10, todi; 11, l'aquila; 12, pirro nord. 153calibration of the upper val d’arno basin ... was identified on the north-western border of the mountain belt while the intramontane basins developed in upper and lower valdarno, and sarzana. their record is based on a mammal fauna that correlates with the mn16a because of absence of equus from it as well as from the sites od western europe (e.g; gea in spain, quoted in lindsay et al., 1997), readily correlated with late gauss and early matuyama. direct calibration to the figure 20 the overall recostruction of the stratigraphic position for the main mammal sites in the northern apennines is shown in the draft assembled by ambrosetti in 1994 and reported in cita & castradori (1994, quoted in albianelli et al., 2002b), and updated for all the results discussed in the present work. the calibrated faunas (positioned by the dots) are sided by the magnetostratigraphic column with normal (black) and reversed (white) polarities; the others (not calibrated, and with the shadowed column) are correlated with the gpts of berggren et al. (1995) by a lesser tight constraint, due to the faible stratigraphic resolution of their biochronological ages. the display follows a general disposition from west to east, to which correspond the dates of each site readable on the gpts, while the faunal units grouping them in the biochronological setting are shown on the vertical scale in the other extreme. for the confidence range of the faunal units dates, see the discussion in the text. 154 g. napoleone et al. gpts of continuous long profiles in the upper valdarno clears up any biochronological uncertainty leading to different scenarios, such as those discussed by lindsay et al. (1997) for the triversa fauna in its villafranca d’asti type area. there, the lower triversa sequence was correlated with the mn15 faunal sequence and with the late gilbert chron. however, this area is out of the northern apennine range while the equivalent fauna of the upper valdarno was directly calibrated in a long magnetostratigraphic series; but the triversa fauna of the type area, with its rather rich sequence, is emphasized because it marks the onset of the villafranchian and its diversification is now estimated during a long time span which as compared with the upper and lower valdarno ones. it is noteworth to recall that the geologic setting was reappraised in great detail (carraro et al., 1995), but its stratigraphic updating by lindsay et al. (1997) seems not correlatable with the upper valdarno series. 6.1.1 the triversa sequence at 3.1-2.9 ma of the kaena/late gauss chrons the triversa sequence (mn16a) comes from several sites along the triversa river near the town of villafranca d'asti in piemonte, and is mainly characterized by its typical elements zygolophodon borsoni, anancus arvernensis, ursus minimus, and the turtle mauremys etrusca (azzaroli, 1977a). the triversa fauna at fornace rdb site is considered the oldest one, and the previous list in all alike the fauna of castelnuovo dei sabbioni is thence dated in the kaena chron, at 3.1 ma. the specimens of fornace rdb were recovered in an unknown position through a short profile of silts and silty sands in the lower part, and sands higher up. its list contains also other species, macaca florentina, castor sp., acinonyx pardinensis, tapirus arvernensis, stephanorhinus jeanvireti, procapreolus cf. cusanus, leptobos stenometopon. among several other sites, the arondelli and san paolo faunas are considered to overlay by few meters the rdb site although the species list is poorer, containing the former one with insectivores (talpa cf. minor) rodents and few carnivores. they were not measured for palaeomagnetism and are placed correlative to the upper late gauss, according to the stratigraphic inferences of azzaroli (1977a). the fornace rdb profile includes a tiny normal polarity magnetozone between the two reversed ones, i.e. a nearly 25 m outcrop with a less than 2 m thick magnetic zone of normal polarity at 12 m level. the two reversals are therefore associable to the mammoth and kaena events in the gauss chron. as a consequence we reject lindsay’s et al. (1997) assignement of the earlier triversa fauna to the gilbert chron an assignment that would make it one million years older than the same faunas in the upper and lower valdarno basins. in our interpretation, then, the triversa faunal unit stems from the gauss chron, close to and/or within the kaena event (fig. 20). the arondelli local fauna, few meters above the main triversa fauna, has not yet been found in the more easterly basins, but is most likely of gauss age as well. its age could match that of the new fauna collected in the lower valdarno (to be discussed in the next section) that has been grouped in the occasion of the magnetostratigraphic exploration of the series, downwards from the montopoli locality and is now dated to not reach 2.9 ma as a lower limit. 6.1.2 lower valdarno finds with triversa affinity, 2.8 ma the oldest finds in the apennine basins, after the upper valdarno local fauna of castelnuovo, are in the lower valdarno. the significant site is in the eastern side of the basin, at the base of the marine sedimentary cycles mentioned earlier, in chapter 2. from there, the tapir recently found and few more remains were dated as coeval with the same fauna of castelnuovo (benvenuti et al., 1995). their age was not fully resolved by the marine sequence, due to a poor biostratigraphic record, as the tentative biozonation assigned the bulk of the sequence to the globorotalia aemiliana zone, therefore with a too large range for the resolution of the present correlation. also the record of the vertebrate fauna released in the lower sequence was poor, but the only one correlatable with that of the upper valdarno, as demonstrated by the magnetostratigraphic dating. this minor faunal assemblage comes from relatively recent discoveries: f irstly a canid nyctereutes megamastoides del campana was found in 1917 at the brick factory chiarugi, and then two jaws of the arvicolid vole mimomys stehlini kormos, followed by a fragmental antler of croizetoceros cf. ramosus (azzaroli, 1992). a lower molar m1 of anancus arvernensis from the piazzano farm, was dated approximately 3 ma by aminochronologic analysis (g. belluomini, 1990, personal communication to azzaroli). near the small town of ponte a elsa, the antlers of a small-sized cervid were recovered and adopted as the species holotype of pseudodama lyra (azzaroli, 1992). finally, an almost complete skeleton of tapirus arvernensis was found in the clay pit of casenuove, with other fragments (dominici et al., 1994). all these specimens may be assembled in a local fauna, the lower valdarno lmf (mn16a), confined in a short time span of emersion between two thick sequences of shallow marine facies, and supposedly at a date not much younger than that of the castelnuovo fauna. in fact, the magnetostratigraphic date of the latter is close to 3.1 ma, while in the lower valdarno the aforesaid date of ca. 3 ma was the only available indication until magnetic stratigraphy of the composite sequence was measured in the overlying marine silts and sands (albianelli et al., unpublished data). it released only one magnetozone of normal polarity, taken as the end of the gauss chron before the montopoli fauna found on top of the marine sequence, and dated at the lowermost matuyama (lindsay et al., 1980). its duration, however, could not be calculated by the magnetic cyclostratigraphy, as it was done in the santa barbara profile. the sequence was made of separate short sections, although well correlated, but not with the required accuracy for detecting the milankovitch periods used in the upper valdarno to date its duration. with an indicative rate of deposition of the marine sequence similar to that measured in the upper valdarno, and the thickness reconstructed from the various outcrops, a time span longer than 200 ky before the matuyama boundary is estimated. so, the lower valdarno fauna with affinity to the triversa faunal unit would not reach a date as old as 2.9 ma and therefore be at least 200 ky younger than the castelnuovo faunal assemblage. the affinity of the latter with the triversa fauna suggests a parallel affinity of the arondelli fauna above the fornace rdb site with the present lower valdarno fauna, based on an equivalent magnetostratigraphic date inferred for the arondelli fauna. 6.1.3 the aulla find near olivola, nw toscana, 3.1 ma (?) in the abandoned clay pit, 1 km out of the aulla town, sarzana basin (val di magra), two small cervid remains were recovered in a 5 m short outcrop (abbazzi et al., 1995). part of a right shed antler was available to inferring the presence of procapreolus cusanus; a psedodama ex gr. pardinensis-lyra was also determined. their little biochronologic resolution is even reduced by a poor preservation, which did not prevent, however, to infer an early villafranchian age. actually, this was assumed in order to replace the previous age of earliest pliocene established by presence of pollen species of a vegetation still maintaining some miocene characters. large excavations, presently made to build the new railway station of aulla, and drilling bore-holes added a 30 m thickness to the sequence, down to the basal lignite-bearing clay. they did not provide a polarity sequence, but only one reversed polarity, as it was also for the 5 m outcropping section (napoleone and albianelli, unpublished data). an expected date for this 35 m thick profile with reversed polarity would suggest a magnetization acquired in the matuyama chron, and the age of this poor record would be assigned to a time younger than the gauss chron. therefore, also this site cannot be assigned a date of the castelnuovo fauna, but quite younger than that and still fitting the very wide range of uncertainty of the biochronologic inferences. from the above discussion the reversed polarity of an early matuyama would date this site younger than 2.58 ma, most probably not reaching 2.5 ma, as it is placed at least 35 m above the onset of the magnetozone and if an average sedimentation rate is assumed close to that of the valdarno basins. 66..22 mmiiddddllee vviillllaaffrraanncchhiiaann mmaammmmaallss this mammal age was a period of scanty finds, also corresponding to a generalized time of widespread transgression on land, which reduced the continental environment. in azzaroli 's (1977a) revision of villafranchian the triversa fauna is the holotype of this land mammal age and represents the early villafranchian, while montopoli represented a new stage. until the present dating of the triversa-like fauna of castelnuovo dei sabbioni and of the subsequent gaussian fauna of the lower valdarno correlated with the arondelli lmf, the time span between triversa and montopoli faunal units was considered large and marked in europe by the arrival of elephant from africa and horse from n. america. the former event is dated now earlier than 3.1 ma, witnessed by the tectonic phase producing the subsidence basins in the apennine intramontane belt, the latter by the montopoli fauna calibrated to 2.58 ma. the half a million year lag from this event to the previous one is now covered by findings of intermediate dates reported for the aforesaid faunas in the upper triversa sequence. for younger ages, the only finds are the poor fauna of todi, which indeed by magnetostratigraphy is tightened very close to the upper limit of the montopoli mammal age, with a similar lag of nearly 0.5 my, but without any intermediate finding in the apennine basins. the montopoli locality contains the richest assemblage of the few ones in western europe, among which that of senèze, dated at the reunion chron, represents the successive saint vallier faunal unit. in italy, an affinity with the fauna of montopoli (mn16b) was attributed to that of costa san giacomo (central italy) (gliozzi et al., 1997). 6.2.1 the montopoli fauna of lower valdarno, 2.58 ma it is the oldest fauna of this period (middle villafranchian), at the base of the matuyama chron, dated shortly after 2.48 ma by lindsay et al. (1980), but the beginning of the matuyama has now been corrected to 2.6 ma (see shackleton, 1995), while the updated scale by berggren et al. (1995) puts it at 2.58 ma. the fauna was collected by forsyth major (1877) near a hilltop south of montopoli, a small town in the lower valdarno, west of firenze and south of the arno river. after the detailed account by forsyth major (1877), the list of fossils was revised by azzaroli and de giuli in order to update the information in the newly created automated catalogue (cioppi et al., 1996). it is fairly rich but fossils are fragmentary: archidiskodon gromovi, anancus sp., stephanorhinus jeanvireti, equus cf. livenzovensis, pseudodama cf. lyra, croizetoceros ramosus, procapreolus cf. cusanus, pliocrocuta perrieri, nyctereutes megamastoides, acynonyx pardinensis. a similar fauna from liventsovka in southern russia, near the azov sea, was described by bajgusheva (1971; 1978; quoted in azzaroli, 2001). the relevance of the montopoli fauna as testimony of a major dispersal event in the late cenozoic was emphasized by lindsay et al. (1980). soon after azzaroli (1983) brought new attention to the problem, having l inked it with the mammal fauna of the himalayan india dated by magnetostratigraphic investigation to the late pliocene and early pleistocene (azzaroli and napoleone, 1981). the faunal diversification there verif ied, was correlated with the late villafranchian fauna of western europe, and its major dispersals, which took place before and after the pliocene/pleistocene boundary, were emphasized (azzaroli et al., 1997) in order to place in a stratigraphic order the villafranchian faunas of the italian peninsula. with the present magnetostratigraphic record these correlations could be revised with a much finer resolution. 6.2.2 the fauna from cava toppetti near todi, umbria, 2.13 ma a poor fauna was collected at cava toppetti, sw of todi, in umbria (abbazzi et al. 1997), and comprises: stephanorhinus cf. etruscus a fragmental scapula pseudodama cf. rhenanus fragments of antlers, two damaged teeth, a hoof phalange procapreolus sp. the basal portion of an antler 155calibration of the upper val d’arno basin ... apodemus cf. dominans a right m1/ this small association is presumed to be younger than the montopoli fauna, despite its poor biochronologic resolution. the fossiliferous beds crop out in the cava toppetti clay pit exploited for the brick factory, at todi, in the ponte naia formation. the series uncomformably overlies the fosso bianco fm, which was calibrated to the latest gauss and early matuyama, and soon after the reunion (fig. 2). the fossil bearing section has not given data of its palaeomagnetism, but from the above biochronological indications it may be considered older than the olduvai chron, and therefore of late pliocene age. it was actually constrained between montopoli and olivola faunal units, whose dates are now avalaible, although the second one will be further discussed in the present work. a major argument to the previous biochronologic assignment of an age is that the olivola unit is now recognized older than 1.95 ma (by possibly 150 ky), and much younger than the reunion (2.24 ma, in the gpts calibrated by baksi, 1993, or 2.15 ma in that used by cande & kent, 1995 and adopted by berggren et al., 1995). this contradicts the geological evidence because these scanty finds are overlying, with a sequence of at least 100 ky duration, the beds with normal polarity of the reunion chron, measured in the same section, but above the major fault that affects the whole valtiberina basin. a larger time span for it would reach the olduvai, which is younger than the olivola fauna, to be discussed, in the next section. more discussion on the pollen distribution and its correlation with the upper valdarno series is made specifically with the lower fosso bianco formation (pontini et al., 2002). a possible lag between their records is detected by magnetostratigraphy and attributed to climatic differences of local origin producing a microclimate. the stratigraphic position of this fauna is visualized in figure 20 as closely before olivola, and therefore strongly confined by the olivola date of nearly 2.1 ma, which will be discussed later. this position is indeed forced against the tight limit of reunion at 2.15 ma and the main fault in between. it seems an evident case for evaluating the resolution power of both chronologies when compared to one another, the highly constraining numerical one of the gpts and the faunal unit sequence of the comparative osteology, which needs very wide margins of confidence for fixing biochronologic affinities. 66..33 llaattee vviillllaaffrraanncchhiiaann mmaammmmaallss this new mammalian age (mn17) was particularly well represented either in the upper valdarno and in the italian peninsula. in the latter, several localities were collected, among which the richest one is at pietrafitta, in umbria (gentili et al., 2000). an important result seems evident: with the present numerical dates available for this continental series, the rich fossil deposits actually exhibit a monotonous composition, because they belong to almost the same narrow range of dates. it has been stressed above, for the upper valdarno, that biodiversification was practically undetectable in the faunal assemblages of the montevarchi sequence, while in the same sediments the magnetic and pollen records clearly detected the severe changes which prepared the break at the pleistocene boundary. the present dates have in fact shortened the time span of the continental sedimentation during which the assemblages remained unchanged, as summarized in the faella collection by its stratigraphical disposition spanning over 220 ky across the olduvai (napoleone & azzaroli, 2002). another important result can be commented. it is now quite clear that the late villafranchian age comes to an end pretty soon in the upper valdarno, the first find being dated 1.99 ma and the last ones demonstrated here to be not much younger than 1.77 ma. in contrast, during last half a century the trend in dating their biochronologic ages was to rather expand the time intervals between various localities, and separate these latter in faunal units in spite of their tenuous palaeontological constraints. the “wolf-event” was actually the only biochronological date to make the divide between the middle and late villafranchian (torre et al., 2001) the example of the matassino assemblage is typical because its first recognized affinity with olivola (representing the basal pleistocene), that led to assigning both of them the same age (azzaroli, 1977a), was progressively shifted to a younger age on the statement that the next tasso faunal unit should be substantially higher up in the early pleistocene, to approach the major faunal turnover of the new age (gliozzi et al., 1997; mazzini i. et al., 2000; torre et al., 2001). such a scheme was actually the basic asset for the biochronologic history of the villafranchian, but the new data brought to light by magnetostratigraphy and reported since a decade (torre et al., 1993; 1996; albianelli et al. 1995; 1997; 2002a) have drastically changed the previous framework. these results are commented stepwise, in a chronologic order mostly inferred from indirect correlations with the gpts magnetochronology. 6.3.1 the olivola fauna of lunigiana, nw toscana, 2.1 ma a rich fauna was retrieved in the late eighteen hundreds by forsyth major (1890) from silts underlying the olivola village, which stands on a hilltop ne of aulla, the main town of the lunigiana district, nw toscana, where the sarzana basin is occupied by the val di magra valley. this will be discussed just after reporting that the fauna was collected in a site already known for a long time for its content of fossil vertebrates: it was visited in the mid eighteen hundreds by igino cocchi and by giovanni capellini, who collected some specimens which were stored in the palaeontological museums of the universities of pisa and bologna. several years later forsyth major undertook a regular excavation and obtained a large collection. most of it was taken to the palaeontological museum of firenze university, some fossils were brought to the british museum (natural history), where among others a fine facial skull of sus strozzii is now stored. fossils were transported by a stream; they are white and brittle, embedded in a pink-yellowish matrix, and as a rule are disconnected, but some articulated, partial limbs were also collected. bones were selected according to size: an elephant is represented only by a partial ulna and radius and part of the carpus; other large herbivores and carnivores are common, smaller species are rare (azzaroli, 1950). the most common species are: 156 g. napoleone et al. stephanorhinus etruscus skulls, jaws, limb bones equus stenonis skulls, jaws, limb bones sus strozzii fragmental skulls, jaws, limb bones leptobos etruscus fragmental skulls, jaws, limb bones eucladoceros dicranios olivolanus partial skulls, jaws, antlers, limb bones pseudodama nestii partial skulls, jaws, antlers, limb bones ursus etruscus partial skulls, jaws, limb bones canis etruscus skulls, jaws, limb bones pachycrocuta brevirostris a maxillary, two jaws, isolated teeth, few limb bones less common elements are: megantereon cultridens a partial skull, fragmental jaws, isolated teeth homotherium crenatidens few teeth lynx issiodorensis an incomplete skull, a maxillary, a jaw, fragments of the pelvis and limbs. these species are also represented in the montevarchi succession of the upper valdarno, with the only exception of eucladoceros dicranios, represented in the upper valdarno by a different subspecies (see below). species recorded in italy only from olivola are: procamptoceras cf. brivatense an upper tooth row gallogoral meneghinii a partial skull, the distal end of a humerus chasmaporthetes lunensis a partial skull felis lunensis (also called felis sylvestris lunensis by ficcarelli and torre, 1974, in azzaroli 1977a) a felid of the size of a common cat: a jaw, partial fore and hind limbs. the first two species occur in italy only at olivola; they also occur in france, in the middle-late pliocene. the problem of dating the olivola site, previously established to represent the base of the pleistocene, was a critical one since the initial calibration in the upper valdarno sites. its age is still lacking a direct magnetostratigraphic exploration, but inferences were made, based on the following statement (cioppi & napoleone, 2001). the matassino fauna was considered, on the biochronological basis, of the same age as olivola for the affinities between them, and then its age was moved stepwise to younger dates than olivola (e.g. azzaroli et al., 1988; gliozzi et al, 1997). separately, the faella fauna -in all alike the matassino onewas dated as old as 1.99 ma (albianelli et al. 2002; napoleone & azzaroli, 2002). the olivola must precede the pleistocene boundary, fixed at 1.796 ma in the end olduvai, by more than 200 ky. moreover, considering that in the upper valdarno the new late villafranchian fauna is retrieved from the terranuova silt and this sequence extends more than 50 ky earlier than the basal fossil find of faella, an upper limit for the olivola date might be as old as 2.05 ma and a lower limit younger than reunion, to which the senéze fauna of the st. vallier faunal unit is calibrated. a date younger than reunion is further fixed as a more recent time by the fauna of todi, already recognized quite younger than reunion but assumed older than olivola. with the biochronological considerations made before, a date of 2.1 ma with a narrow excursion (say, less than ± 50 ky) is conceivable for olivola, and this puts its date quite older than any other one reported so far. this shift to the late, and not even the latest pliocene has been pushed back since the first calibration of the matassino fauna (torre et al., 1993), when the upper valdarno faunas of the montevarchi succession were already considered quite younger than olivola. with the present magnetostratigraphic calibration, all these faunas are quite aged, as shown in the previous chapter, being dated still prior to the onset of the olduvai chron (albianelli et al., 2002a; napoleone et al., 2001b). the yellowish silt of the fossil deposit is exposed at olivola for about 1 m in thickness and is magnetized with reversed polarity: this is not in conflict with the discussion made before, but not decisive for defining a more precise date than that just inferred at 2.1 ma. 6.3.2 the recent finds from north of roma, 2.0÷1.75 ma (?) an occasional find at monte riccio, in the northern lazio district, 10 km inland from the tyrrhenian sea and 100 km n of roma, was the first locality from that area and dated after the analogies with the fauna of the upper valdarno (mazzini i. et al., 2000). in a 30 m section of very shallow marine facies, attributed to the late pliocene by the geological evidence in the area, a terrestrial fauna was deposited during a short episode of emersion. a biostratigraphically poor association is based on ostrea, clamys, pecten, etc., mostly indicating the low water depth, and a similar estimate was provided by the benthic foraminifera. an ostracod with stratigraphic meaning, cyperideis torosa, would be noticeable for its first appearence being at the beginning of the pleistocene. nonetheless, this is one of the few occasions, in the italian peninsula, to have an indication of biostratigraphic dating for a terrestrial fauna. a fairly rich assemblage overlying the marine detrital sequence is formed by the following specimens: prolagus sp. two fragmentary molars elephantidae cf. archidiskodon meridionalis some limb bones and a dental lamina sus strozzii fragmentary mandible and a metapodial hippopotamus sp. a fragment of the skull leptobos cf. leptobos etruscus two frontal bones, a metacarpal procapreolus sp. fragmentary frontal bones with the basal part of the antler eucladoceros ctenoides a basal part of an antler, some molars, a tibia fragment, a calcaneum of juvenile specimen pseudodama? metapodials, fragmentary limb bones, jugal teeth stephanorhinus cf. s. etruscus a fragmentary humerus, radius and tibia equus stenonis an almost complete mandible very similar to the holotype from the upper valdarno, a fragmentary scapula vulpes cf. vulpes alopecoides part of mandible with two molars canis etruscus a fragmentary mandible with two molars and a left hand in anatomical connection megantereon cultridens a metatarsal the range of these species spans a large interval, but their association leads to a restricted age comprising 157calibration of the upper val d’arno basin ... the olivola and tasso faunal units (mazzini i. et al., 2000). this indication led to assigning an age derived from the alleged age of the latter in the late part in the erly pleistocene, still used in the catalogue and in the most recent accounts (gliozzi et al., 1997; torre et al., 2001). but this resulted an inference very weak for the monte riccio section, as the biochronological range of the tasso fauna is actually poorly defined, and even less is the biostratigraphic timing of the profile with a generical age as pleistocene. the presumed age, at the resolution of the tasso faunal unit, was arbitrarily used in a stratigraphic meaning for its upper early pleistocene age, disregarding the indication of the only fossil there recognized with a stratigraphic meaning for a presence started since the beginning of the pleistocene. nonetheless, the affinity with the tasso fu still provides an age indication better constrained than that of a broader pleistocene given by the marine fossils of this short series, and dated with the accuracy fixed for the tasso fu by the new magnetochronologic constraints. therefore, with a tasso fu dating soon after the olduvai, its age would be in the earliest pleistocene, in a very limited range before 1.7 ma, and anyhow quite shorter than that assigned in figure 20 to the faunal unit. 6.3.3 the firenze basin, 1.8÷1.7 ma firenze lies in an old lacustrine basin which, unlike the upper valdarno, was never filled completely. scanty fossils were collected. on the right bank of the arno, in the centre of the town, some limb bones of an elephant were retrieved during excavations for the building of barracks. on the left bank, south of porta romana, in the southern outskirts of the town, an elephant tusk and few molars were collected. a fragment of a metatarsal cannon of leptobos was retrieved in a railway tunnel north of the town. a portion of the nasal bone of a rhinoceros was collected near signa, at the western end of the lacustrine basin and a fragment of a left maxillary was collected from a well near prato, in the north of the basin. these remains do not allow for a more accurate biochronological timing than the age of the latest montevarchi sediments or shortly younger (the farneta fauna?, see below). the magnetic stratigraphy is not available, due to lack of convenient outcrops, but its stratigraphic position is here assigned to an age earlier than that of the next fauna only on the basis of the biochronological indications, which were indeed recalled in several aforesaid occasions to yield a too large range of uncertainty. 6.3.4 the late villafranchian fauna of farneta, 1.7÷1.6 ma the farneta abbey is placed on a series of hills of fluviatile sands which run to the right (east) of the chiana river, a southern tributary of the arno. a rich fauna surrounds it and extends southwards until the boundary between toscana and umbria near pozzuolo. in quarries north and west of the boundary with umbria, remains of elephants and other fossils, including a beaver, were collected. a large sized subspecies of the elephant, archidiskodon meridionalis vestinus, dominates the fauna (azzaroli 1977b); the type of the species is from scoppito, west of l’aquila, central italy (fig. 19), and was described as elephas meridionalis by maccagno (1962). small sized deer are represented by the progressive species pseudodama farnetensis (azzaroli 1992) and the valdarno eucladoceros has been replaced by the more derived megaceroides obscurus, a forerunner of the middle pleistocene megaceroides verticornis. the geological setting of the area, also described by azzaroli (1992) to argue the slight differentiation of cervids in toscana (azzaroli, 1947), leads to a stratigraphic position slightly younger than the upper deposits of the montevarchi unit in the adjacent upper valdarno. the quarrying is over and not sufficiently long sequences with fresh cuts are useful for palaeomagnetic sampling. a date however could be expected close to the end olduvai, i.e. not much younger than 1.77 ma, possibly in the range of the tasso fu with the gpts; as a direct magnetostratigraphy is lacking, the biochronologic indications are partly maintained for correlation with the stratigraphic setting of the tasso unit in figure 20. the adjustments in repositioning the fossil sites are made for the ones dated by magnetostratigraphy. only the todi and olivola ages are moved because of their stringent magnetochronological evidence. the biochronological ages of the others are partly correlated with the gpts dates, but emphasizing that their shadowed columns, by the side, earlier represented the time span presumed for the extent of the sequences lacking the magnetostratigraphic calibration, and cover the minimum range of uncertainty in this indirect correlation or pseudo-calibration. 6.3.5 selvella fauna, 1.7÷1.6 ma farther south-east, in umbria, a more poorly preserved fauna was retrieved by de giuli (1986) at selvella. it includes equus cf. stenonis, pseudodama sp. (farnetensis?), a large cervid called eucladoceros cf. dicranios (possibly a megaceroides obscurus?; see azzaroli, 1953), leptobos sp., canis etruscus, lynx issiodorensis, sus sp. and an undetermined elephant. fossils are less bulky than those collected around farneta: the stream which carried them was slowing down. arkidiskodon meridionalis vestinus is poor: few limb bones. equus stenonis, a large sized eucladoceros, and a leptobos are mainly represented by limb bones; pseudodama farnetensis is also documented by fragmental antlers, carnivores are documented by a facial skull of canis etruscus and a fragmental jaw of a lynx. the age of this locality matches that of farneta, representing only a different depositional setting, more downstream; thus, the same date of the farneta fauna is assigned to it in the representation of figure 20, although in absence of magnetic stratigraphy. 6.3.6 mugello basin, 1.7÷1.6 ma sited north of firenze and in a deep depression with a more than 600 m thick pile drilled in the central basin, this was another lacustrine basin where the fossil record had been collected for a long time, from scattered sites and without notes on their position. fossils 158 g. napoleone et al. mainly come from the lignite-bearing levels, and the interfingered or overlying clays. in the latest mining operations a rhinoceros -a small skulland an archidiskodon meridionalis vestinus -a dextral femurwere recovered and kept in the museum of firenze. important recoveries in the eighteen hundreds were kept in the museums of pisa and bologna. a rather fragmental fossil assemblage of 13 species is from the sands overlying the lignite-bearing clays and represents a fauna similar to the one of farneta. it mainly includes tusks and other bones of the large sized elephant, ursus etruscus, sus strozzii, a pseudodama, fragments of a large cervid not identified specifically, a derived rhinoceros recalling those from pietrafitta (see in next section), mustela sp. and a macaque (macaca florentina), poorly represented by fragmentary remains. the short length of the sections with the fossil recoveries, and their correlation, not sufficiently accurate to allow a cyclostratigraphic determination of the time spans involved in a given sequence, prevented assigning a date to the three surveyed sites (albianelli & napoleone, unpublished data). rock magnetic properties were among the best ones for the continental sediments so far examined in the apennine basins, but unfortunately the main result was to have measured only one reversed polarity, which leads to a matuyama chron younger than olduvai. transferring the biochronological affinities into the established asset of the numerical dates, one may figure out a date still close to 1.7 ma used for the end of the montevarchi sequence, which is also a date very close to that of the farneta fu. the range of the latter is arbitrarily kept in figure 20 too wide, as presumed by the previous biochronologic assignments, and thus placed quite younger than that of tasso. the position of the mugello fauna is not drawn in figure 20. 6.3.7 some notes on the pietrafitta fauna, 1.6÷1.5 ma a very rich fauna with several elephant skeletons was collected during excavations for the extraction of l ignite at pietrafitta, in umbria, south of lake trasimeno. the fauna has not been studied and only few species have been described (gentili et al. 1996, mazza et al. 1993). the species l ist contain: archidiskodon meridionalis vestinus, stephanorhinus hundsheimensis, equus sp., leptobos aff. vallisarni, megaloceros obscurus, pseudodama farnetensis, ursus etruscus, panthera gombaszoegensis, pannonictis nesti i , macaca cf. f lorentina, castor plicidens, oryctolagus etruscus, microtus (allophaiomys) cf. ruffoi, microtus (allophaiomys) chalinei, mimomys pusillus, sorex sp., talpa sp. among other species, a large deer is documented by an antlered skull and several other remains, megaceroides boldrinii, named after its collector (azzaroli & mazza, 1992). the best preserved specimen is a juvenile antlered skull. there are, in addition, fragmental antlers belonging to at least seven individuals, a right jaw and some limb bones. the antlers display an exceedingly high variability, which is interpreted as evidence of a genetical instability preceding the evolution leading to m. obscurus and in the galerian to m. verticornis. for the same reasons as with the mugello fauna, the uncertainty for the dates is relatively large, and a possible date would be quite older than the reported 1.5 ma for the farneta fauna in figure 20. the short section presently outcropping has been sampled for palaeomagnetics, and its samples showed very stable directions. it recorded only one reversed polarity (albianelli & napoleone, unpublished data) presumably a matuyama date not better defined, but still not much younger than the end of the olduvai, based on the biochronological affinities with the farneta fauna. 6.3.8 the faunas from pirro nord in se italy this fauna was retrieved by de giuli and collaborators near pirro nord, in the surroundings of apricena, at the eastern foot of the mountains of the gargano promontory in the south-east of the italian peninsula. the geologic setting is devoid of a detailed stratigraphic position, while the fauna is still under study; a preliminary note was published by de giuli et al. (1986), attributing a still younger age to it, while specific aspects were also reported (mazza, 1987; mazza et al., 1993; masini & santini, 1991). the most characteristic element of the fauna is eobison, a genus of intermediate morphology between leptobos and bison, represented by a partial skull with a bulging forehead, a jaw and two rather short and massive metacarpals. the fauna, collected from several sinkholes, is rich. it includes an elephant, a rhinoceros (may be stephanorhinus), a rather slender limbed equid with stenonid features in its dentition, a pseudodama more derived than p. farnetensis, a megaceroides, sus, megantereon cf. cultridens, homotherium crenatidens, pachycrocuta brevirostris, canis arnensis, canis falconeri, ursus etruscus, vulpes cf. alopecoides, hystrix, apodemus, microtus, hypolagus, lepus, miniopterus, myotis, rhinolophus, talpa. with the lack of any stratigraphic indication sharper than the biochronological one (ficcarelli et al., 1996), the dating of this fauna, which was distinguished in a unit representing the end of the villafranchian mammal age, is positionable in a wide range of the gpts. but it is also quite likely that the next dramatic change, which will occur with the turnover at 1 ma, took place after a long sedimentation gap, due to a long tectonic activity in the apennines and/or to a generalised unfavourable state of environmental conditions for the continental deposition. therefore, a date still not much younger than 1.7 ma is conceivable, also in view of the indication deriving from the evidence discussed shortly below. meanwhile, its position is arbitrarily maintained in figure 20 at a higher stratigraphic level. 66..44 eenndd ooff tthhee vviillllaaffrraanncchhiiaann aanndd ttrraannssiittiioonn ttoo tthhee nneeww aaggee aatt tthhee jjaarraammiilllloo bboouunnddaarryy,, 11..0055 mmaa the alleged middle pleistocene following the end of the villafranchian saw the development of a large number of mammalian species and new adaptations: the large deer megaloceros and megaceroides, the heavy bovids bos, bison and ovibos. equids differentiated into a large number of species, the cold-adapted mammuthus made its appearance. the new age has been related to a major event in the pleistocene, which makes the turnover to the middle pleistocene. it is calibrated in the gpts to the jaramillo chron, so that a date for its onset is fixed at 1.05 ma. in the upper 159calibration of the upper val d’arno basin ... valdarno, the last testimony of a faunal association in the bucine fauna was classified to an age of late middle pleistocene, while in the present magnetochronologic reconstruction is dated at the base of the jaramillo or at most at the base of the brunhes. out of the upper valdarno, the beginning of this new age has the first example with the colfiorito and oriolo faunas, because they are directly calibrated by means of magnetostratigraphy to the gpts. another site of comparable age had a palaeomagnetic survey, the outstanding site of isernia with its human remains, but is not calibrated because its magnetostratigraphy yielded only one normal polarity, interpreted as an early brunhes from biochrological and anthropological inferences (sala, 1990; sala & fortelius, 1993). 6.4.1 the alleged middle pleistocene fossils from the farneta area the late villafranchian deposits of farneta described above are overlain by coarser sediments with a scanty fauna of galerian age. remains of a skull of megaceroides verticornis were retrieved from the vicinity of farneta abbey and further south, at pozzuolo and petrignano in umbria. remains of a hippopotamus were collected near farneta. here it can be recalled that, lacking a time constraint until the date of 1 ma, the time span between the farneta fauna and these remains of galerian age is cancelled by the coarser sediments just mentioned. the same case was reported in the upper valdarno where the gap between the end of the montevarchi series at nearly 1.7 ma and the new one overlying the conglomerate on both sides of the arno river bank at nearly 1.05 ma or 0.78 ma, was, on the contrary, measured by magnetic stratigraphy thus lasting 0.7 my or 1 my. therefore, a similar condition would be repeated in valdichiana after the deposits of the farneta localities. above the gravel bed, the new faunal remains would date roughly 1 my younger than last villafranchian deposits, as calibrated in the adjacent upper valdarno in the profile of cava minuto (fig. 17) succeeding the late pliocene one of faella. 6.4.2 the fauna of colle curti this fauna was recovered in the colfiorito basin, on the apennines not far east of the watershed between umbria and marche. it was palaeomagnetically dated at the onset of the jaramillo and therefore close to 1 ma, with an age calibrated to it for the emilian bio-chronostratigraphic stage (coltorti et al., 1998). the beginning of the great faunal revolution from late villafranchian to galerian is related to such an event. the fauna, still under study, is signif icant, represented by megaceroides verticornis and stephanorhinus cf. hundsheimensis, two typically galerian elements, with some survivors from late villafranchian: pseudodama cf. farnetensis, canis arnensis, canis cf. falconeri, ursus cf. etruscus, microtus (allophaiomys) cf. pliocaenicus and a large sized variant of hippopotamus antiquus (borselli et al., 1988; ficcarelli & mazza, 1990). its stratigraphic position is in a 12 m thick silt level, overlying a longer series of sand layers, in correspondence with the polarity change from a reversed to a normal magnetozone. the transitional characters of the colle curti assemblage are therefore peaked at the magnetic polarity transition, dated 1.05 ma in the gpts. another date at 426 ka was provided by the radiometric timing of the tephra contained in the paleosol level unconformably overlying the basin fill. 6.4.3 the fauna of cesi in the same basin of colfiorito, at cesi, few km away, a 10 m sequence of silt containing the fossil site and overlain by the same paleosol with the tephra dated 426 ka was assigned a higher stratigraphic position than the previous one at colle curti. the polarity couplet of reversed and normal directions was referred to the only possible polarity change younger than the jaramillo of colle curti (ficcarelli et al., 1997). the fauna was with more differentiated characteristics, and this led, together with the radiometric date of the overlying paleosol, to assigning the polarity chron a magnetostratigraphic date of the end matuyama, at the boundary with brunhes. a long separation between the deposits of these two colfiorito faunas, from jaramillo to brunhes, was actually introduced on the bases of such preliminary inferences rather than by firm stratigraphic markers recognized in their distant profiles. both sequences extended over ca. 10 m thick beds of massive fine sediments, capped by the paleosol layer containing the dated tephra. the date of an early brunhes was therefore tentative, expecially when compared with similar results from the oriolo fauna, reported in the next section, which in contrast supports the choice of the jaramillo date. both sites are positioned (fig. 20) according to the previous constraints but are left in that yielded by the biochronologic determination, while magnetochronology would have been undetermined between brunhes or jaramillo boundary. the fauna includes among others stephanorhinus cf. hundsheimensis, hippopotamus sp., megaceroides solhilacus, cervus elaphus, dama clactoniana, bison schoetensacki, homotherium, and an indetermined elephant (archidiskodon meridionalis vestinus ?) whose date at the onset of the brunhes chron would extend its previous range of distribution (torre et al., 1996), known so far until the jaramillo. 6.4.4 the fauna of oriolo the finds are scarse and include scanty remains of hippopotamus, rhinoceros, horse, bison and elephant in a 20 m thick section through the transitional sequence from the sand unit overlying the main blue clay formation of the external apennines. most representative are the skull of bison cf. schoetensacki at the bottom and a skull of archidiskodon meridionalis vestinus close to the top, in a reversed polarity and in a normal one, respectively. this disposition does not contradict an assigned date to the jaramillo, although the sedimentary indications suggest a more recent age, while the former was preferred because the a. meridionalis vestinus is known until the jaramillo and its extension to the brunhes would deserve a stronger support by a widespread recognition rather than the generalised age of the geologic setting. therefore, all three sites lately measured are datable in the transition to the jaramillo, which could also be 160 g. napoleone et al. the date of the bucine fauna of the upper valdarno, leading to a conclusion that no one fauna so far examined in the northern apennines would be representative of the new mammal age. this time span should be searched in the records of younger basins, as are those from the southern apennines. one example has been reported from the san arcangelo basin, already mentioned (sabato et al., 2002), and with new palaeomagnetic data which calibrate a section nearly 200 m thick, spanning from the reversed polarity before the jaramillo to the beginning of the brunhes (albianelli et al., unpublished data). in a lateral section, where the fossiliferous site with a poor fauna of micromammal species was found (masini et al., unpublished data), the measured magnetic polarity was in the brunhes, and the biochronologic indication suggested an age of this site related to an early brunhes (masini, personal communication). 77.. ccoonncclluussiioonnss magnetic stratigraphy has now dated the upper valdarno series in the gpts system, and therefore this basin results one of the oldest in age and the one of longest duration among the sequences in the intramontane basins of the italian peninsula. it spans from middle through late pliocene, up to the beginning of the pleistocene, during which two major steps of the appennine uplift brought about such extensional basins, in a time span comprised in the magnetostratigraphic framework of 1.5 my (fig. 2). the second one, in particular, produced a long gap in the lacustrine sedimentary record, dated to last more than 0.7 my. the first interruption, instead affected the faunal and pollen records, which registered the main climatic events of the glacial pliocene. in fact, from the magnetochronological criteria, the bases were developed for a new concept in dating faunal complexes, which provided facts of a tangible and substantial renovation (lindsay, 2001). by themselves, they warrant a radical revision of what was established in more than one and a half centuries, until azzaroli (1977a) decidedly pointed to the stratigraphical significance of the historical content inherent in the museological collection of fossil vertebrate faunas of the upper valdarno, with which the history of the museum of firenze was started. the awareness of the lack of basic chronological data for all ancient collections brought us to look for new ways of confering a more significant dating to the biochronological criterion which had been protracted since the first results of the comparative osteology of cuvier (1824). through inductive ways, comparing what had already been established with magnetostratigraphic criteria of dating continental sedimentary sequences, the mammal faunas of most apennine basins may be reasonably dated with a highly improved accuracy, assigning them the ages of the pliocene and pleistocene biostratigraphic record. also classical vertebrate fossils of the upper valdarno collections in the museum of firenze were dated with a resolution of few thousand years out of an age of nearly 2 ma, due to the direct calibration of their sites within the magnetostratigraphic series of 2.5 my there established. for the geological setting of the sedimentary series, the newest data provided by dating the time span between major events, such as the duration of the upheaval pulses and breaks of sedimentation, put fundamental steps for re-defining the history of the basin fill. the sedimentation started at 3.3 ma in the mammoth magnetochron, but the bulk of the lake deposits is dated after the short episode of the lignite seam (may be shorter than 3.13 to 3.08 ma) across the boundary of 3.11 ma for the kaena chron. the thick meleto-clay pile of silts lasted until 60 ky before the gauss-matuyama boundary of 2.58 ma, and was replaced by sand deposits (san donato sands) rapidly filling the basin. the g/m boundary was recorded during a subaerial deposition (rena bianca sands) when a condensed series of sand accumulated until shortly before the reunion chron at 2.15 ma. this dating is the most recent result, first reported in this work, and the implications need to be discussed with great attention. after this interruption (at 2.64 ma) a lacustrine-fluviatile regime was restored with the montevarchi sequence shortly after 2.15 ma. the new silty sediments have been recently found in contact with the sand, and therefore the reunion was immediately followed by the reversed matuyama polarity. the first mammal fauna is recovered in layer beds dated 1.99 ma, after which its blooming is recorded thoughout 220 ky and with resolutions of very high accuracy, while several important facts occur at the same time and are now dated in the upper valdarno series. the main events coeval with the faunal record are the two magnetostratigraphic boundaries between gauss and matuyama and the end-olduvai. the first calibrates to the gpts the chronostratigraphic boundaries of the middle and late pliocene, and the second the end of pliocene and the beginnig of the quaternary. this makes the upper valdarno continental sequence the reference series for correlating the apennine continental basins on the bases of events on the global scale which produce the main changes in the geologic system. two main climatic changes were documented in the geologic system. one was the temperature oscillations on a trend of decreasing values, observed in the oceanic record by the oxygen isotope ratios (summarized in shackleton et al., 1984). the other one observed in the continental areas was given by the pollen percentage changes, reproducing vegetational assemblages of wet/temperate forest alternating with those from herbs and sprouts of a dry/cold vegetation (summarized in zagwijn, 1974; leroy & seret, 1992). the former took place as a decreasing temperarture marked by the increasing of the absolute values of the oxygen ratios, which began to cyclically oscillate with the 41 ky period, as the obliquity atronomical parameter, while approaching the boundary between middle and late pliocene. its calibration has been updated by shackleton (1995). the latter confirmed the trend of decreasing temperatures by remarking a decrease in pollen percentage of the arboreal plants, from a forest vegetation of a warm and wet climate towards a cooler one, leading then to an oscillating abundance of forest and herb pollen sporomorphs. this condition spinned up in the olduvai, when it drastically jumped to nearly 90% of the steppe vegetation representative herbs dominated by artemisia, while in the ocean the oscillating ratio moved to periods of 100 ky, the short eccentricity cycle. the magnetic signal was capable of detecting both changes in the milankovian periodicities, acting as another proxy independently to the previous ones, and to date very accura161calibration of the upper val d’arno basin ... tely their occurrences. the earlier one was enhanced by the onset of the obliquity cycle taking place at 2.85 ma a date representing the initial conditions leading to the pliocene glacial/interglacial alternation systemand overprinting the precessional one which was prevailing before. the second one by calibrating the p/p boundary in the continental deposits where the highest percentage of herbs pollen was recorded in correspondence to the level beds just preceding the pleistocene by few tens of ky. this is another date of critical relevance because its recording in the marine series of vrica, southern italy, decidedly contributed to fixing there the ‘golden spike’ for the pleistocene boundary stratotype, “just before the end of the olduvai”, at 1.796 ma (zijderveld et al., 1991). in these ages accurately dated, also the upper valdarno faunas were all dated at high resolution. the range spanned from 50 ky to 2 ky, according to the degree of accuracy for their positions reported with the recovery, from the ones only located in a broad area or stratigraphic level to the ones with detailed positions, given the present magnetostratigraphical framework. it begins in the gauss chron and extends throughout the olduvai (1.77ma), thus establishing an essentially continuous magnetostratigraphic reconstruction of the continental series, after which an interruption of nearly 1 my was documented in the basin fill. more outcrops of these continental deposits may be uncovered by excavations for industrial purposes, and thence more data would be added. in the prospect of new results, some of the closest ones may be suggested as an outlook. improving the dates of the museum collections. high resolution dating of the upper valdarno fauna from the main collections in the museum of firenze was made at ± 2 ky for the fossil sites with accurate positions, and at ± 50 ky for those reported in the catalogue without indication of a precise position. to this group belong almost 75% of the upper valdarno collections, which will have in the present magnotochronologic framework the best reference for reconsidering their broad datings of specimens labeled so far as simply pliocene or pleistocene. with such a resolution, a review of information available in the automated catalogue is highly recommended; as a conclusion of the present work, the ages of most of these faunas would shift from pleistocene to the last 300 ky of the pliocene. the first dates were already assigned, and their numerical uncertainties were close to ± 10 ky; this resolution seems viable for the specimens of several collections. a second point would deal with the pollen events, as changes in their percentages can be dated with the same accuracy reached in the mammal fauna, so that subtle changes can be ordered in time series in order to analyse the climatic changes. the main global events were already identified in the upper valdarno record: refinements at a higher order can detect minor changes between close areas, at the scale of microclimates, such as that already tested in the apennine basins, where differential upliftings may have affected their paleoenvironments. the case of a short diachronism, measured between upper valdarno and valtiberina pollen records at the gauss/matuyama boundary, can be extended to other basins to reconstruct the history of the climatic changes in the italian peninsula. a further point would focus attention on the correlation of the marine series of the italian peninsula with the calibrated upper valdarno series, by reversing the prospects for a finer resolution. the continental sequences are now very well dated series, with a time resolution extremely high and able to improve, for most sequences through the apennines, that of the biozonation, which is in contrast rather poor in these critical ages from pliocene to pleistocene. the stages around the boundary, best represented in the italian sequences, may have a number of detailed tests dealing with dated sequences to reconstruct the comprehensive sedimentary geology, produced after nearly a century since that compiled by gignoux. the present case of the mid and late pliocene sequence of the marchean pelites calibrated to the gpts (this volume) demonstrates the role represented by the upper valdarno magnetochronology as a reference sequence. a direct correlation between these series, documenting the upheaval of the apennine range on both sides of the watershed, is producing dates of various episodes of its tectonic activity. the conclusive figure 20 shows the faunal distribution of the main portion of the classical sites and few recent ones that have been calibrated to magnetochronology. some crucial faunal units remain to be calibrated, as olivola and tasso. for both of them only a short continuous sequence can be measured, and this will add little information. more important would be to calibrate the interval from the olduvai to jaramillo which includes the faunal units of farneta and pirro. they are now positioned in a more appropriate relationship with the gpts reference than previously attempted without a close magnetostratigraphic reference, such as the present one of the upper valdarno. a new accurate timing can be used for reporting on finds which will be recovered with stratigraphic indication, and from magnetochronology trying to set up the various evidences to reconstruct for them a biochronologic history with stratigraphic criteria. aacckknnoowwlleeddggmmeennttss the present work benefited during several years from the help of numerous scientists and organizations, in the field recognition on pit sections. new fossil recoveries provided fundamental markers for the biochronologic asset of the late villafranchian, leading to a reconstruction of a magnetostratigraphic profile where a detailed positioning of their sites dated the ages directly to the gpts. the owners of the pits recalled in this work are deeply aknowledged for letting us survey any available outcrop, especially the brothers del buffa who opened new trenches at matassino and poggio rosso for recovering fossil remains and sampling fresh outcrops for magnetostratigraphy. several organizations provided cores from bore-hole drilling. the administrators of the terranuova bracciolini township put to our disposal two cores from the hilltop near the casa frata site, which yielded the tasso sand and oreno sand in the montevarchi series. the administrators of the montevarchi township let us sample two cores drilled in the arno bed, which hel162 g. napoleone et al. ped to extend downwards the profile of the montevarchi series. two more were made available in the rena bianca by the owners of the pit, and their few limy beds confirmed the presence of the gauss/matuyama boundary at its bottom. the enterprise people in charge (ing. bianchini) provided us with two cores drilled in the aulla railway station that supported the idea of a younger date than gauss for the aulla site. the continuous financial support from both our organizations, the museum and the department of the firenze university, is deeply aknowledged for helping in the operations of recovering fossil material and surveying for sections eligible for pollen and stratigraphic profiles. in the course of a decade several persons helped in the field works: to all of them our best thanks are addressed. the murst national grant to g.n. for the project on high resolution magnetic stratigraphy was most valuable for completing this work. several new results are reported in this occasion, after the more recent measurements, which have been carried out in zurich at the eth palaemognetic laboratory: its facilities have been used for collecting all our data and for this we are deeply indebted. from friedrich heller we always received advises and all the warmth of his friendship, with his continuous interest for the present work while in progress. rreeffeerreenncceess abbate e., bortolotti v., passerini p. & sagri m., 1971 introduction to the geology of the northern apennines. sedimentary geology, 44, 207-250. abbazzi l., ficcarelli g. & torre d., 1995 deer fauna from the aulla quarry (val di magra, northern apennines). biochronological remarks. riv. it. paleont. strat., 110011, 341-348. abbazzi l., albianelli a., ambrosetti p., argenti p., basilici g., bertini a., gentil i s., masini f., napoleone g. & pontini r., 1997 paleontological and sedimentological record in the pliocene distal alluvial depostis at cava toppetti (todi, central italy). boll. soc. paleont. it., 3366, 5-22. albianelli a., 1995 proprietà magnetiche e magnetostratigrafia dei sedimenti anossici fluvio-lacustri e marini coevi. phd. diss., univ. of firenze, 139 pp. albianelli a., bertini a., magi m., napoleone g. & sagri m., 1995 i l bacino plio-pleistocenico del valdarno superiore: eventi deposizionali, paleomagnetici e paleoclimatici. il quaternario (italian journal of quaternary sciences), 88, 11-18. albianelli a., azzaroli a., bertini a., ficcarelli g., napoleone g. & torre d., 1997 paleomagnetic and palynologic investigations in the upper valdarno basin (central italy): calibration of an early villafranchian fauna. riv. it. paleont. strat., 110033, 111-118. albianelli a., bertini a., hinnov l.m., napoleone g. & fischer a.g., 1999 mid pliocene climatic change in the valdarno basin, italy paleomagnetic exploration of lacustrine sediments at the milankovitch scale. gsa ann. mtg, 25-28 oct., 1999, denver (co). (abt) albianelli a., magi m., mazzini m. & napoleone g., 2002a the plio-pleistocene boundary in the northern apennine continental deposits as defined by the faella magnetostratigraphic section in the upper valdarno. boll. soc. geol. it., pialli special vol., 11, 473-479. albianelli a., cantalamessa g., didaskalou p., micarelli a., napoleone g. & potetti m., 2002b dating pliocene series of the external apennines in central italy for correlation with continental sequences. this volume azzaroli a., 1947 i cervi fossili della toscana, con particolare riguardo alle specie villafranchiane. palaeontogr. italica 4433, 45-82. azzaroli a., 1950 osservazioni sulla formazione villafranchiana di olivola in val di magra. atti soc. tosc. sc. nat., mem., 5577, 104-111. azzaroli a., (1952) sul recente ritrovamento di uno scheletro di elephas meridionalis presso montevarchi. accademia valdarnese del poggio, memorie, ser. v, 11, 47-52, montevarchi. azzaroli a., 1953 the deer of the weybourn crag and forest bed of norfolk. bull. brit. museum (nat. history) geology, 22, 1-96, london. azzaroli a., 1967 lineamenti geologici del bacino fluvio-lacustre del valdarno superiore. comitato neogene medit. iv congr., bologna. guida alle escursioni, 161-172. azzaroli a., 1977a the villafranchian stage in italy and the plio-pleistocene boundary. giornale di geologia, 4411, 61-79. azzaroli a., 1977b evolutionary patterns of villafranchian elephants in central italy. mem. acc. naz. lincei, cl. sci. fis. mat. nat., ser. viii, 1144, 129-168. azzaroli a., 1983 quaternary mammals and the “endvillafranchian” dispersal event. a turning point in the history of eurasia. pelaeogeogr., palaeoclim., palaeoecol., 4444,, 117-139. azzaroli a., 1984 on some vertebrate remains of middle pleistocene age from the upper valdarno and val di chiana, tuscany. palaeontogr. italica, 7733, 104-115. azzaroli a., 1992 the cervid genus pseudodama n.g. in the villafranchian of tuscany. palaeontogr. italica, 7799, 1-41. azzaroli a., 1995 the “elephant-equus” and the “endvillafranchian” dispersal events in eurasia. in: vrba e.s., denton g.h., partridge t.c. and burckle l.s., eds.: palaeoclimate and evolution, with emphasis on human origins. yale university press, 311-318. azzaroli a., 1998 hystrix etrusca bosco, the late villafranchian porcupine from the upper valdarno, central italy. palaeontogr. italica, 8855, 177-198. azzaroli a., 2001 middle and late villafranchian vertebrates from tuscany and umbria. a synopsis. boll. soc. paleont. it., 4400, 351-356. azzaroli a. & mazza p., 1992 the cervid genus eucladoceros in the pleistocene of tuscany. palaeontogr. italica, 7799, 41-100. azzaroli a. & napoleone g., 1981 magnetostratigraphic investigation of the upper sivaliks near pinjor, india. riv. it. paleont. strat., 8877, 739-762. azzaroli a., de giuli c., ficcarelli g. & torre d. 1988 late pliocene to early pleistocene mammals in 163calibration of the upper val d’arno basin ... eurasia: faunal succession and dispersal events. pelaeogeogr., palaeoclim., palaeoecol., 6666, 77100. azzaroli a., cioppi e. & mazzini m., 1992 il museo di geologia e paleontologia dell'università degli studi di firenze, sezione vertebrati, 76a riunione estiva soc. geol. it., firenze, 21-23 sett. 1992, 19 pp. azzaroli a., colalongo m.l., nakagawa h., pasini g., rio d., ruggieri g., sartoni s. & sprovieri r., 1997 the pliocene-pleistocene boundary in italy. in: van couvering j.a., (ed), the pleistocene boundary and the beginning of the quaternary. world and regional geology series, 99, cambridge univ. press, 141-155. baksi a.k., 1993 a geomagnetic polarity time scale for the period 0-17 ma, based on 40ar/39ar plateau ages for selected field reversals. geophys. res. lett., 2200, 1607-1610. benvenuti m., dominici s. & rook l., 1995 inquadramento stratigrafico-deposizionale delle faune a mammiferi villafranchiane (unità faunistiche triversa e montopoli del valdarno inferiore nella zona a sud dell’arno (toscana). il quaternario (italian journal of quaternary sciences), 88, 457464. berggren w.a., kent d.v., swisher iii c.c. & aubry m.p., 1995 a revised cenozoic geochronology and chronostratigraphy. am. ass. petrol. geol., sepm special publ. n. 5544, 129-212. bertini a., 1994 palynological investigations on upper neogene and lower pleistocene sections in central and northern italy. mem. soc. geol. it., 4488, 431-443. bertini a. & roiron p., 1997 evolution de la végétation et du climat pendant le pliocène moyen en italie centrale: apport de la palynologie et des microflores à l’étude du bassin du valdarno supèrieur, coupe de santa barbara. c.r. acad. sci. paris, sér 2e, 332244, 763-771. billi p., magi m. & sagri m., 1991 pleistocene lacustrine fan delta deposits of the valdarno basin. jour. sedim. petrology, 6611; 280-290. borselli v., de giuli c., ficcarelli g. & mazzini m., 1980 casa frata, una località fossilifera del villafranchiano superiore presso terranuova bracciolini (arezzo) nel valdarno superiore. boll. soc. paleont. it., 1199: 245-258. borselli v., ficcarelli g., landucci f., magnatti m., napoleone g., & pambianchi g., 1988 segnalazione di mammiferi pleistocenici nell'area di colfiorito (appinnino umbro-marchigiano) e valutazione delle potenzialità del giacimento con metodi geofisici. boll. soc. paleont. it., 2277, 253-257. cande s.c. & kent d.v., 1995 revised calibration of the geomagnetic polarity time scale for the late cretaceous and cenozoic. jour. geophys. res., 110000, 6,093-6,095. capellini g., 1908 mastodonti del museo geologico di bologna. ii, 11 pp., 2 pls, tipografia gamberini & parmeggiani. carraro f., (ed.), 1996 revisione del villafranchiano nell’area-tipo di villafranca d’asti. il quaternario (italian journal of quaternary sciences), 99, 5-120. cioppi e. & napoleone g., 2001 the fossil vertebrate database of the natural history museum of florence and high-resolution magnetostratigraphy in the upper valdarno basin, as a clue to date old collections. riv. it. paleont. strat., 110077, 297-303. cioppi e., dorbolò d. & berdondini e., 1996 gef: un sistema di catalogazione automatizzata delle collezioni paleontologiche. museologia scientifica, 1133, 9-21. cioppi e., dominici s. & mazza p., 2001 le collezioni paleontologiche della marchesa paulucci consevate presso il museo di storia naturale di firenze. museologia scientifica, 1166, 219-229. cocchi i., 1856 description des roches ignées et sedimentaires de la toscane dans leur succession géologique. bull. soc. géol. france, 1133, 226-301. cocchi i., 1867 l’uomo fossile nell’italia centrale. studi paleontologici. mem. soc. it. sci. nat., milano, 22, 1-80. coltorti m., albianelli a., bertini a., ficcarelli g., napoleone g. & torre d., 1998 the colle curti mammal site in the colfiorito area (umbrianmarchean apennines): stratigraphy and palynological analysis. quaternary international, 4477, 107116. combourieu-nebout n., 1993 vegetation response to upper pliocene glacial-interglacial cyclicity in the central mediterranean. quaternary research, 4400, 228-236. combourieu-nebout n. & vergnaud-grazzini c., 1991 late pliocene northern hemisphere glaciations: the continental and marine responses in the central mediterranean. quaternary science review, 1100, 319-334. cuvier g., (1824) recherches sur les ossemens fossiles, où l’on retablit les caractères de plusieurs animaux dont les révolutions du globe ont détruit les espèces. 2nd ed., v tom. de giuli c., 1986 late villafranchian faunas in italy: the selvella local fauna in the southern chiana valley, umbria. palaeontogr. italica, 7744, 11-50. de giuli c. & masini f., 1986 late villafranchian faunas in italy: the casa frata local fauna (upper valdarno, tuscany). palaeontogr. italica, 7744: 1-9. de giuli c., masini f. & torre d., 1986 the latest villafranchian faunas in italy: the pirro nord fauna (apricena, gargano). palaeontogr. italica, 7744: 5162. demenocal p.b. & bloemendal j., 1995 pliopleistocene climatic variability in subtropical africa and the palaeoenvronment of hominid evolution: a combined data-model approach. in: vrba e.s., denton g.h., partridge t.c. and burckle l.s., eds.: palaeoclimate and evolution, with emphasis on human origins. yale university press, 262288. deng t., xue x. & dong x., 1999 the evidence of fossil carbon isotopes of the climatic event at the beginning of the quaternary. chinese science bulletin, 4444, 477-480. dominici s., rook l., benvenuti m. & abbazzi l., 1994 tapir remains in paralic deposits of pliocene age in lower valdarno (tuscany, italy): facies analysis and taphonomy. geobios, mem. spec., 1188, 131-135. ficcarelli g. & mazza p., 1990 new fossil findings from the colfiorito basin (umbrian-marchean apen164 g. napoleone et al. nine). boll. soc. paleont. it., 2299, 245-247. ficcarelli g., masini f., mazza p. & torre d., 1996 the mammals of the latest villafranchian in italy. in: turner c., (ed.): the early middle pleistocene in europe: 263-272. a.a. balkema, rotterdam, brookfield. ficcarelli g., abbazzi l., albianelli a., bertini a., coltorti m., magnatti m., masini f., mazza p., mezzabotta c., napoleone g., rook l., rustioni m. & torre d., 1997 cesi, an early middle pleistocene site in the colfiorito basin (umbro-marchean apennine), central italy. jour. quat. science, 1122, 507-518. forsyth major, c.j., 1877 considerazioni sulla fauna dei mammiferi pliocenici e post-pliocenici della tocana. atti soc. tosc. sci. nat., proc. verb., 33, 202-221. forsyth major, c. j., 1890 l’ossario di olivola in val di magra (provincia di massa carrara). proc. verbali soc. tosc. sci. nat., 2 marzo 1890. gentili s., abbazzi l., masini f., ambrosetti p., argenti p. & torre d., 1996 voles from the early pleistocene of pietrafitta (central italy, perugia). acta zool. cracov., 3399, 185-199. gentili s., barili a. & ambrosetti p., 2000 lignites, fossils and miners! a paleontological heritage at pietrafitta (perugia, central italy). museologia scientifica, 1166, 27-40. gliozzi e. & 20 more authors, 1997 biochronology of selected mammals, molluscs, ostracods from the middle pliocene to the late pleistocene in italy. the state of the art. riv. it. paleont. strat., 110033, 369-388. heller f., liu x.m., liu t.s. & xu t.c., 1991 magnetic susceptibility of loess in china. earth planet. sci. lett., 110033, 301-310. lazzeri l., 1977 carta geologica del valdarno superiore, con note illustrative di a. azzaroli. cnr, centro studi dell’appennino settentrionale, 6 pp. leroy s. & seret g. 1992 duration and vegetation dynamics of the nogaret interglacial (1.9 ma, s of france): tentative correlation with stage 75. in: g.j. kukla and e. went (eds.), start of a glacial. springer verlag, nato asi series 1(3), 113-125. lindsay e.h., 2001 correlation of mammalian biochronology with the geomagnetic polarity time scale. boll. soc. paleont. it., 4400, 225-233. lindsay e.h., opdyke n.d. & johnson n.m., 1980 pliocene dispersal of the horse equus and late cenozoic mammalian dispersal events. nature, 228877, 135-138. lindsay e.h., opdyke n.d., fejfar o., 1997 correlation of selected late cenozoic european mammal faunas with the magnetic polarity t ime scale. pelaeogeogr., palaeoclim., palaeoecol., 113333, 205226. maccagno a.m., 1962 l’elephas meridionalis nesti di contrada “madonna della scala”, scoppito (l’aquila). accad. sci. fis. mat. di napoli, atti, 44, 1-132. magi m., 1999 rilievo geologico di dettaglio dell'area di faella e di matassino, nell'ambito della carta geologica del valdarno superiore. (open file nhmfu, 19 pp.) magi m. & sagri m., 1996 aeolian sand sheets and terminal sands: sedimentological evidences of arid climatic condit ions in the plio-pleistocene valdarno basin (northern apennines, italy). 17th ias regional african-european mtg, sfax, tunisia, abt, 172-173. magi m., marri c. & sagri m., 1992 carta geologica del bacino fluvio-lacustre del valdarno superiore. 76a riunione estiva soc. geol. it., firenze, 21-23 sett. 1992, riassunti, 187-188. martini i.p. & sagri m., 1993 tectono-sedimentary characteristics of late miocene-quaternary extensional basins of the northern apennines, italy. earth-science reviews, 3344,, 197-233. masini f. & santini g., 1991 microtus (allophaiomys) (arvicolidae, rodentia, mammalia) from cava pirro (apricena, gargano) and other italian localities. boll. soc. paleont. it., 3300, 355-380. masini f. & torre d., 1990 large mammal dispersal events at the beginning of the late villafranchian. in: lindsay e.h., fahlbusch v. and mein p., (eds), european neogene mammal chronology, nato asi series a, 180, plenum press, new york, 131138. mazza p. 1987 prolagus apricenicus and prolagus imperialis: two new ochotonids (lagomorpha, mammalia) of the gargano (southern italy). boll. soc. paleont. ital., 2266, 233-243. mazza p., 1997 taphonomic analysis of late middle pleistocene mammal remains from bucine (upper valdarno, tuscany, central italy. boll. soc. paleont. it., 3366,, 381-390. mazza p., sala b. & fortelius m., 1993 a small latest villafranchian (late early pleistocene) rhinoceros from pietrafitta (perugia, umbria, central italy), with notes on the pirro and westerhoven rhinoceroses. palaeontogr. italica, 8800, 25-50. mazzini i., paccara p., petronio c. & sardella r., 2000 geological evolution and biochronological evidences of the monte riccio section (tarquinia, central italy). riv. it. paleont. strat., 110066, 247-256. mazzini m., borselli v., cioppi e. & napoleone g., 2000 poggiorosso: un importante arricchimento delle faune a vertebrati villafranchiane del valdarno superiore. boll. soc. paleont. it., 3399, 381-388. mein p., 1990 updating the mn zones. in: lindsay e.h., fahlbusch w. & mein p. (eds), european neogene mammal chronology, nato asi series a, 180, plenum press, new york, 73-90. merla g., 1951 geologia dell’appennino settentrionale. boll. soc. geol. it. 7700, 95-382. merla g., & abbate e., 1967 note illustrative della carta geologica d’italia foglio 114 arezzo. servizio geologico d’italia, 52 pp. napoleone g. & albianelli a., 2002 magnetic susceptibility cycles in lacustrine deposits of northern apennines. am. ass. petr. geol., sepm special publ. (in press). napoleone g. & azzaroli a., 2002 a collection of fossil vertebrates from the upper valdarno (central italy) calibrated tn the end pliocene to span 220,000 years across the olduvai magnetochron. riv. it. paleont. strat., 110088, 479-492. napoleone g., albianelli a. & mazzini m., 2001a the fossil rhinoceros found by nesti on 1811 dated in the final pliocene by magnetostratigraphy of the upper valdarno sequence. boll. soc. paleont. it., 165calibration of the upper val d’arno basin ... 4400, 249-256. napoleone g., albianelli a., azzaroli a. & mazzini m., 2001b the poggio rosso locality calibrated to the end-pliocene and its significance for dating the late villafranchian faunas of the upper valdarno, central italy. riv. it. paleont. strat., 110077, 287-296. napoleone g., albianelli a., azzaroli a. & mazzini m., 2001c dating the upper valdarno fossil vertebrate collections in the natural history museum of firenze from its magnetochronology in the pliocene framework of the northern apennine continental sequence, italy. boll. soc. paleont. it., submitted. nesti f., 1811 sopra alcune ossa fossili di rinoceronte. tip. piatti, firenze, 24 pp. nesti f., 1825 sulla nuova specie di elefante fossile del valdarno. tip. nistri, pisa, 23 pp. pareto m., 1865 sur les subdivisions que l'on pourrait etablir dans les terrains tertiaires de l'appennin septentrional. bull. soc. géol. france, 2222, 210277. pasini g. & colalongo m.l., 1997 the plio-pleistocene boundary-stratotype at vrica, italy. in: van couvering j.a., (ed), the pleistocene boundary and the beginning of the quaternary. world and regional geology series, 99, cambridge univ. press, 15-45. pontini m.r., albianelli a., basilici g., bertini a. & napoleone g., 2002 palynologic and magnetostratigraphic investigation of the lacustrine sequence in the tiberino basin. boll. soc. geol. it., pialli special vol., 1, 467-472. rook l., 1994 the plio-pleistocene old world canis (xenocyon) ex gr. falconeri. boll. soc. paleont. it., 3333, 71-82. sabato l., bertini a., masini f., albianelli a., napoleone g., & pieri p., 2002 the early and mid pleistocene record of the san lorenzo lacustrine sequence in sant’arcangelo basin (southern apennines, italy). terra nova (in press). sala b., 1990 panthera leo fossils (v. reichel, 1906) (felidae) de isernia la pineta (pléistocène moyen inferieur d’italie). geobios, 2233, 189-194. sala b. & fortelius m., 1993 the rhinoceroses of isernia la pineta (early middle pleistocene, southern italy). palaeont. italica, 8800, 157-174. shackleton n.j., backman j., zimmerman h., kent d.v., hall m.a., roberts d.g., schnitker d., baldauf j.g., despraisries a., homrighausen r., huddlestun p., keene j.b., kaltenback a.j., krumsiek k.a.o., morton a.c., murray j.w. & westberg-smith j., 1984 oxygen isotope calibration of the onset of the ice-rafting and history of glaciation in the north atlantic region. nature, 330077, 620-623. shackleton n.j., 1995 new data on the evolution of climatic variability. in: vrba e.s., denton g.h., partridge t.c. and burckle l.s., eds.: palaeoclimate and evolution, with emphasis on human origins, 311-318. yale university press. spassov s., heller f., evans m.e., yue l.p. & ding z.l., 2001 the matuyama/brunhes geomagnetic polarity transition at lingtai and baoji, chinese loess plateau. phys. chem. earth (a), 2266, 899904. suc j.p., bertini a., combourieu-nebout n., diniz f., leroy s., russo-ermolli e., zeng z., bessais e. & ferrier j., 1995 structure of west mediterranean vegetation and climate since 5.3 ma. acta zool. cracov., 3388, 3-16. torre d., 1967 i cani villafranchiani della toscana. palaeontogr. italica, 6633,, 113-138. torre d., albianelli a, azzaroli a., ficcarelli g., magi m., napoleone g. & sagri m. 1993 palaeomagnetic calibration of late villafranchian mammalian faunas from the upper valdarno, central italy. mem. soc. geol. ital., 4499,, 355-344. torre d., albianelli a., bertini a., ficcarelli g., masini f. & napoleone g., 1996 paleomagnetic calibration of plio-pleistocene mammal localities in central italy. acta zool. cracov., 3399, 559-570. torre d., abbazzi l., bertini a., f. fanfani, ficcarelli g., masini f., mazza p. & rook l., 2001 structural changes in italian late pliocene-pleistocene large mammal assemblages. boll. soc. paleont. it., 4400, 303-306. van couvering j.a., 1997 preface. in: van couvering. j.a., (ed.), the plio-pleistocene boundary and the beginning of the quaternary. world and regional geology series, 99, xi-xvii. cambridge university press. zagwijn w.h. (1960) aspects of the pliocene and early pleistocene vegetation in the netherlands. mededelingen van de geologische stichting, ser. c, 3 (5): 1-78. zagwijn w.h. (1974) the plio-pleistocene boundary in western and southern europe. boreas, 3: 75-97. zijderveld j.d.a., hilgen f.j., langereis c.g., verhallen p.j.j.m. & zachariasse w.j., 1991 integrated magnetostratigraphy and biostratigraphy of the upper pliocene lower pleistocene from the monte singa and crotone areas in calabria, italy. earth planet. sci. lett., 110077, 697-714. 166 g. napoleone et al. sess 0_retro e indice edi.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 ms. received: testo ricevuto il mediterranean sapropels and plio-pleistocene high-low latitudes connections florence colleoni1, simona masina 1,2, alessandra negri 1,3 & alice marzocchi1 1 cmcc, bologna, 2 ingv bologna 3 universita’ politecnica delle marche, ancona corresponding author: a. negri <a.negri@univpm.it> abstract: colleoni et al. mediterranean sapropels and plio-pleistocene high-low latitudes connections. (it issn 0384-3356, 2011) we present a comparison of the mediterranean stable isotopic planktic foraminifera record to analogous records in the atlantic ocean in order to evidence the high-low latitude connections during the plio-pleistocene interval. riassunto: colleoni et al., sapropel del mediterraneo e connessione tra alte e bassse latitudini nel plio-pleistocene. (it issn 0384-3356, 2011) abbiamo confrontato uno studio del record isotopico dell’ossigeno ottenuto su foraminiferi planktonici nel mare mediterraneo con record analoghi provenienti dall’oceano atlantico per evidenziare le possibili connessioni climatiche tra alte e basse latitudini durante il plio-pleistocene.. key words: mediterranean sea , sapropel, high-low latitude connections parole chiave:mare mediterraneo, sapropel. connessione alte-basse latitudini during the late pliocene, a gradual cooling of the global climate led to the onset of northern hemisphere glaciations toward 3 million years ago (ma). through external forcings and internal climate feedbacks, the mediterranean testifies of these large scale climate changes by means of rhythmic sediment, alternating marly limestone, marls and organic carbon rich sediments layers (sapropel). we consider the planktonic δ18o stack of four mediterranean cores (medstack, lourens et al., 2004 ; wang et al., 2010) spanning the entire plio-pleistocene period. the medstack is further compared with four north atlantic high latitudes benthic δ18o records and north atlantic tropical benthic δ18o and aeolian dust flux records. the time-evolutive power spectrum of these timeseries were performed on the orbital bands at 100 kyr, 41 kyr and 23 kyr. results show that the climate variability of the mediterranean is tightly linked to that of the tropical records prior the onset of northern hemisphere glaciations, being dominated by precession. after 3 ma, all latitudes exhibit a similar variability with increasing power in the 41 kyr band, in both benthic and planktonic records. however, the mediterranean seems to be still influenced by tropical climate dynamics which is in turn paced, after ~2.5 ma, by high latitudes glacial/interglacial alternation. references lourens l. j. (2004) revised tuning of ocean drilling program site 964 and kc01b (mediterranean) and implications for the d18o, tephra, calcareous nannofossil, and geomagnetic reversal chronologies of the past 1.1 myr. paleoceanography 19, pa3010. wang p., tian j. & lourens l. j. (2010) – obscuring of long eccentricity cyclicity in pleistocene oceanic carbon isotope records. earth planet. sc. lett. 290, 319-330. 207 january 13, 2011 13 gennaio 2011 connection with the valtellina to the northwest and trentino to the northeast. the area surrounding the site is characterized by glacial geomorphological structures, small moraine ridges, and impressive gravitational phenomena that have led to landslides of large blocks of rock, made unstable by the retreat of glaciers, which broke away from the mountainsides. these large blocks also served as shelters for shepherds until recently. geologically, the area is characterized by the presence of basement rocks such as schists, but, locally, there are limited outcrops of white marble (locally called vezza or canè marble depending on where it was quarried). according to seventeenth-century local tradition, the toponym torre dei pagà refers to the legendary passage of charlemagne through valcamonica, where he is said to have defeated the last pockets of pagan resistance associated with the lombards (biancardi, 2022). the archaeological potential of the area, first noted by ausilio priuli in 1976, prompted mario mirabella roberti to carry out a brief survey in july of the following year. this investigation confirmed the presence of ancient wall structures, although their precise chronology remained uncertain (mirabella roberti, 1987). in 2011, the municipality of vione launched a project to enhance its archaeological heritage, initiating a research programme in collaboration with the catholic university of milan. to date, fourteen annual summer excavation campaigns have been carried out, up to 2018 on behalf of sabap (soprintendenza archeologia belle arti e paesaggio) for the provinces of bergamo and brescia, and since 2019 under concession from the ministry of culture. available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 38 (2), 2025, 133-149 https://doi.org/10.26382/amq.2025.08 1. introduction excavation campaigns carried out since 2011 at the locality of tor dei pagà (2250 m a.s.l.), in upper valcamonica (vione, bs), have revealed substantial remains of medieval fortifications dating to the late 13thearly 14th century, as well as evidence of ritual activities at the site during the iron age (between the late 7th and 5th centuries bc) (bellandi, 2017; bellandi et al., 2015). during the excavation of the medieval layers, however, few knapped lithic artifacts attributable to the mesolithic were also recovered, likely originating from deposits at the base of the archaeological sequence. although no additional evidence or absolute dating is currently available, the presence of these artifacts alone pushes the earliest human occupation of tor dei pagà back to the beginning of the holocene, placing the site within the broader framework of mesolithic settlement across the lombard alpine arc by the last hunter-gatherer groups (lo vetro et al., 2022a). 2. the geographical context of tor dei pagà and the history of research the site of tor dei pagà lies at an elevation of 2,250 m a.s.l., approximately 1,000 metres above the village of vione, in the upper valcamonica (bs) (fig. 1). the action of glaciers during the last glacial phase and the holocene geomorphological reorganization strongly characterize the area. the tor dei pagà site is located on a steep ridge with the canè valley to the east and the vione valley to the west. the natural continuation of the morphological ridge on which the site is located establishes a direct mesolithic presence at tor dei pagà: an early holocene settlement in eastern lombardy (italy) conforti jacopo 1 , bellandi giovanna 2 , bona fabio 3 1 dipartimento di scienze della terra e geoambientali, università di bari aldo moro, bari, italy. 2 archaeologist, freelance. via angelo righetti 16, brescia, italy. 3 palaeontologist-archaeozoologist, freelance. piazza scaglia 6, casalbuttano ed uniti (cr), italy. corresponding author: bona fabio <fabiobona1@gmail.com> abstract: the site of tor dei pagà (2,250 m a.s.l.), in the upper valcamonica (vione, brescia), is is notable for its rich archaeological stratigraphic sequence, which includes an iron age ritual area (late 7th-5th centuries bc) and the remains of fortified structures from the late middle ages (late 13th-early 14th centuries). the recovery of a small number of knapped lithic artifacts of mesolithic attribution from within the medieval layers pushes the earlies human presence at tor dei pagà back to the early holocene. however, the lack of absolute dating and the absence of clearly diagnostic artifacts currently prevent a more precise cultural assignement to either the sauveterrian or castelnovian. despite their scarcity, these elements alone allow to place tor dei pagà within the broader framework of mesolithic settlement in the lombard alpine arc, reflecting the exploitation of high-altitude areas tied to subsistence strategies and to the strengthening of social networks and inter-valley connections with the trentino region by the last hunter-gatherer groups. keywords: mesolithic, iron age, later middle ages, high-altitude exploitation, valcamonica. archaeological investigations have uncovered a complex fortified system consisting of two towers (g and b) (fig. 2), each positioned at the apex of a layout that includes a perimeter wall, internal buildings, and additional associated structures in the surrounding area. the finds, among them several coins and radiocarbon dates of samples obtained from two larch beams, indicate that the fortification was built and occupied for a relatively short period, between the late 13th and early 14th centuries. in 2015, evidence of an earlier occupation phase was identified beneath one of the late medieval towers (tower b), dating from the late 7th and 5th centuries bc. this layer consists of carbon-rich deposits containing remains of offerings: bronze artefacts, fragments of ceramic jugs, and burnt bones. such contexts are well 134 conforti j. et al. fig. 1 a, positioning of tor dei pagà site (basemap: esri world topo). b, panoramic overview of the site from west. (photo g. bellandi) fig. 2 site plan, letters refer to the identified structures: north tower g with the courtyard delimited by the wall e and the internal building h, i and l; south tower b with the area b1 and the wall with no yet name; a, d and f are not yet well defined structures. (map elaboration by c. alexander and r. valente) 135 mesolithic settlement in upper valcamonica fig. 3 the material culture: 1. copper alloy lyre buckle; 2. iron d-buckle; 3-4. circular buckles in copper and iron alloy; 5. silver alloy floral applique; 6. vago in glass paste; 7. bone die; 8. iron furniture key; 9-12. iron crossbow bolt projectile points; 13-14: iron arrowheads (photo by f. airoldi). known in alpine archaeology and widely documented in nearby south tyrol and trentino, where they are referred to as a brandopferplätze, or "alpine-style votive pyre" (bellandi, 2017; bellandi et al., 2015). 3. chronological phases of the site 3.1. the late medieval phase and material culture occupation of the area during the late middle ages appears to have been considerably more complex and structured. the site today comprises a system of structures featuring at least two towers. one of these (tower g) occupies the highest point of a complex comprising of a polygonal outer wall (e) and several internal buildings (h, i, and l). the other, tower b, lies approximately 200 metres away along the rocky ridge descending from cima bles. this second tower is likewise enclosed by a wall and includes internal rooms (bellandi et al., 2017; sannazzaro, 2016) (fig. 2). the presence of two towers and two very similar structural complexes in such proximity remains the topic of debate. gis analyses based on a high-resolution dsm generated by uav mapping have suggested that tower b may have been added to address a tactical flaw in the position of the original com 136 fig. 4 c14 date of tor dei pagà. red square: tower g (respectively from a larch beam rings 18-26 and same larch beam rings 39-49); blue square: tower b (unspecified wooden beam); green square: brandopferplatz (respectively from a calcinated bone and a charred twig). fig. 5 the material culture of the protohistoric phase: 1. bronze serpentine arch fibula with fold-holding disk; 2. bronze conical phalera tip; 3. bronze eyelet strap; 4. bronze spiral pendant; 5. bronze double spiral pendant; 6. metal sheets and various objects partially deformed by the heat of the fire (photo by g. vanoglio). conforti j. et al. ward. this context corresponds closely to the brandopferplatz typology: alpine cult sites characterised by ritual burning practices that developed between the middle bronze age and the iron age and in many cases continued in use into the roman period (solano, 2017). 3.3. the soil (us246) at the base of the archaeological stratigraphic sequence lies a yellowish-brown (10yr5/8 4/6) soil that originally extended uniformly across the two areas investigated. this soil is characterized by a sandy spodic horizon (bs), the structure is very fine and well expressed. the soil developed directly from the weathering of the underlying parent material (micaschist and, locally, marble veins). human activity has reworked and disturbed it in several parts of the site, and in some areas, it has been completely removed. this geological body, originally and still today where not removed by human activity, is distributed across the entire mountain ridge where the visible archaeological structures develop. the age of this soil formation is unknown, but it unquestionably predates the occupation that took place during the middle of the first millennium bc. the presence of a small yet significant set of knapped lithic artefacts attributable to early holocene (see paragraphs 6 and 7), likely originating from this basal layer, allows us to hypothesize that the soil itself dates at least to the early holocene (fig. 6). 4. post-mesolithic environment: palaeobotanical data from the iron age and late middle ages in the anthracological remains from the iron age ritual fires in tower b, conifers dominate with picea abies, larix decidua, pinus cembra and pinus sylvetris/ mugo well represented. the wide ring growth observed in picea abies suggests that the wood derived from trees growing at the forest edge or in relatively open, plex: an area of non-visible “dead ground” to the west of the original structure, that could have exposed the fortification to direct assault (alexander, 2017). according to this interpretation, tower b would therefore post-date tower g. this hypothesis is supported not only by the excavation data from area b1, but also by analyses of the mortars from the two towers, which reveal compositional differences between those used in tower b and those in tower g (bugini & folli, 2017). the dating of the finds recovered from the site (fig. 3), including several coins and the radiocarbon analysis (martinelli & pignatelli, 2017), indicates that the fortification was built and occupied for a relatively brief period, between the late 13th century and the early decades of the 14th century (fig. 4). 3.2. the iron age phase beneath the walls and floor surfaces of one of the medieval towers (tower b), traces of an earlier protohistoric phase were identified and subsequently dated to between the 7th and 5th centuries bc, based on radiocarbon analyses (bassetti & degasperi, 2017) and typological comparisons of the objects recovered (bellandi, 2017; marzatico, 2017) (fig.s 4 and 5). the deposit consists of the remains of repeated burning episodes in two distinct areas identified during the archaeological excavation. charcoal, mainly from spruce and larch, was recovered together with burned bone and cereal remains, all contained within the dark, ashy soil of the fire (castiglioni & cottini, 2017). fragmentary metal objects damaged by heat were also found, including fibulae, double spirals, and objects apparently linked to armour, such as a rare phalera tip (fig. 5). among the ceramic fragments, vessels with finely smoothed surfaces and occasional linear incisions or cord impressions, there are large and small mugs comparable to forms known from nearby trentino (accessible via the tonale pass and the val di sole), as well as cups and bowls. these materials appear to have served a ritual function, either as offerings placed into the fire or as libation vessels intentionally broken after 137 fig. 6 stratigraphic section in ene-wsw direction, seen from the north. in this section, the contact between the late medieval phase (lme) stratification and the soil (brown) is visible. the complete series, including the protohistoric phase, is visible only in some portions at the top of the area directly below or adjacent to tower b. scale bar: 1 metre. (modified by bassetti & degasperi, 2017). mesolithic settlement in upper valcamonica isolated positions. ericaceae, including kalmia procumbens and rhododendron ferrugineum/hirsutum, as well as salix sp. are also present, likely used as fire starters or possibly for other ritual purposes. the iron age environment was therefore very similar to that of today: a coniferous forest dominated by picea abies and larix decidua with pinus cembra occurring more sporadically and ericaceae shrub formations dominated by kalmia procumbens present at higher elevations. (castiglioni & cottini, 2017). anthracological evidence from the later middle ages similarly reflects a natural landscape dominated by conifers. picea abies appears as the dominant species and was used as firewood, with larix decidua also present and pinus cembra rare. in the hearth in structure e, twigs of calluna vulgaris, arctostaphylos sp. and other ericaceae were found. the twigs were collected during the summer season, when the last annual growth ring had fully developed. palynological analyses of four mortar and lime samples reveal that human activities at the site does not appear to have left traces. instead, the results primarily reflect the surrounding vegetation, which again is very similar to that of today: coniferous forests, alder stands in the wettest areas, grasslands and moorland (castiglioni et al., 2017). 5. mesolithic settlement between prealpine lombardy and western trentino despite the limited number of knapped lithic artefacts recovered at tor dei pagà and the absence of absolute dating that would allow a secure chronological contextualisation, the techno-typological characteristics of the assemblage, considered together with the geographical setting of the site, suggest a plausible attribution to the mesolithic. within the framework of the present study, this attribution is treated as a working hypothesis that requires contextual evaluation. to this end, it is appropriate to outline the evidence for mesolithic occupation within the broader geographical area in which tor dei pagà is located, namely, the lombard pre -alpine-alpine arc and the region largely encompassing western trentino (fig. 7). this regional overview draws primarily recent synthetic studies that have substantially updated current knowledge of human settlement dynamics in north-eastern italy during early holocene (e.g. lo vetro et al., 2022a; fontana et al., 2023). 138 fig. 7 selected mesolithic sites of lombard prealpine-alpine arc and western trentino: 1. ispra, 2. baranzini, 3. valganna-dosso tra laghi di torba e ganna, 4. tana di erbonne, 5. erbonne cimitero, 6. pian dei cavalli ca15, 7-8. pian dei cavalli ca1 and ca13, 8. pratizagni di sotto, 9. monte cornizzolo, 10. passo s. marco, 11. alpe azzaredo, 12. grotta del pussu, 13. pizzo formico, 14. colle san zeno, 15. croce di marone, 16. pian del bene di sopra, 17. monte stalletti, 18-19. cascina valmaione 1 e 2, 20. stanga di bassinale, 21. malga rondaneto, 22. san glisente, 23. laghetti del crestoso, 24. laghetto di dasdana, 25. lago ovest di ravènola, 26. fienile rossino 2, 27. sopra fienile rossino, 28. roccolo di serle, 29. vaiale, 30. laghetto di vaia, 31. dosso gavia, 32. passo gavia-malga dell’alpeval di gavia, 33. cividate camuno via palazzo, 34. foppe di nadro riparo 2, 35. cemmo, 36. zufallhtitte, 37. samerberg, 38. laugen i, 39. laugen ii, 40. le regole 3, 41-51. passo della mendola i-ii-iii-iv-v-vi-vii-viii-ix-x-xi, 52. gangelbühel-doss de la forca, 53. mezzacorona-borgonuovo, 54. campo carlomagno, 55. zambana loc. vatte, 56. m.te gazza passo, 57. pradestel, 58. riparo gaban, 59. doss trento, 60. la vela, 61. zambana "el vato", 62. madonna bianca, 63. romagnano loc iii, 64. viotte costa dei cavai, 65. acquaviva, 66. bus de la vecia, 67. paludei volano, 68. vezzano loc. naran, 69. terlago lago montepiana, 70. moletta patone, 71. arco pra de gom, 72. pozza lavino, 73. passo s. barbara, 74. busa dell' adamo, 75. carbonare, 76. riparo cogola, 77. m. pasubio-rif. lancia, 78. malga campo, 79. madonna della neve, 80. malga artillione, 81. passo delle fittanze-ala, 82. riparo soman (map data from: https:// doi.org/10.13127/tinitaly/1.1., graphic elaboration f. bona & j. conforti). conforti j. et al. 1993, 1997; biagi et al., 1994, 1995; biagi & nisbet, 2008; biagi & starnini, 2015, 2016; biagi et al., 2017). some key radiocarbon dates place the earliest occupation at valmaione 2 in the preboreal (grn-20093: 9410 ±80 bp; grn-20890: 9630 ±100 bp). malga rondeneto represents a short summer frequentation in the boreal (grn-19590: 8880 ±150 bp). the high altitude site of lago ovest di ravènola (1957 m a.s.l.), located in a transitional area between the grigna and camonica valleys, also dates to the boreal (grn-26800: 8160 ±100 bp; gra-59653: 8725 ±40 bp), shows a small non-local flint assemblage consistent with sauveterrian complexes (biagi, 1976b, 1981, 1985, 1997, 1998; biagi & starnini, 2015). castelnovian evidence in the brescia area includes riparo 2 di foppe di nandro (biagi, 1981, 1983, 1997), as well as several mediumand highaltitude contexts. in the pre-alpine area, on the cariàdeghe plateau, sites such as fienile rossino 2 (903 m a.s.l.), roccolo di serle (947 m a.s.l.), and especially sopra fienile rossino (950 m a.s.l.), dated between the boreal and atlantic periods (bln-3277: 6810 ±70 bp) (biagi, 1972; accorsi et al., 1987), have yielded structural evidence (a pit and a posthole) and rich lithic industry (approximately 2,000 pieces) combining, among the armatures. sauveterrian elements and trapezes. the site, located within a broadleaf forest, must have functioned as a hunting station frequented between spring and autumn, as indicated by the presence of hazelnut shells (accorsi et al, 1987). in val trompia, the site of laghetti del crestoso. located in an area strongly shaped by glacial activity at 2,000 m a.s.l. (biagi, 1992; baroni & biagi, 1997), produced several structural features (hearths and postholes) and several hundred lithic artefacts, mostly local materials. based on lithic assemblage and radiometric data, a multi-phase castelnovian occupation during the has been suggested: an initial occupation at the beginning of the atlantic (grn-21889: 7870 ±50 bp; grn-21889: 7850 ±80 bp), characterized by trapezes with retouched truncations associated with sauveterrian microliths, and a second phase (grn-18091: 6870 ±70 bp; har-8871: 6790 ±120 bp), where sauveterrian elements progressively disappeared and the industry was marked by the spread of trapezes with piquant trièdre (baroni & biagi, 1997). further castelnovian evidence in the brescia area comes from valmaione 2 (biagi & starnini, 2015, 2016), passo di san glisente (biagi, 1998), and pozza oltre la stanga di bassinale (1861 m a.s.l.), though in the latter the association between material and radiometric date is uncertain (grn-20886: 6330 ±45 bp) (biagi et al., 1994; biagi, 1997; lo vetro et al., 2022a). surface finds between valcamonica, val sabbia, and val trompia have been recorded in mountain passes, near small lakes, or in dominant topographic positions: at lago di dasdana (1875 m a.s.l.) (biagi et al., 1979), monte stalletti (1550 m a.s.l.), croce di marone (1160 m a.s.l.), pian del bene di sopra (1520 m a.s.l.), and colle san zeno (1434 m a.s.l.) (biagi, 2002). colle san zeno may belong to the sauveterrian, whereas the few pieces found at the other sites do not allow for an attribution beyond a generic mesolithic. farther into the interior alpine zone (fig. 7), significant sites include passo gavia-malga dell’alpe (bagolini et al., 1978; bagolini & nisi, 1980) and dosso gavia (2360 m a.s.l.) (angelucci et al., 1994) where, a stratigraphic excavation identified a sauveterrian lithic as5.1. the mesolithic in lombard pre-alpine-alpine arc lombardy has yielded numerous indications of human presence during the mesolithic, across the alpine sector to the north and the pre-alpine hills and plains to the south (lo vetro et al., 2022a). over the past thirty years, extensive multidisciplinary research has investigated the paleoenvironmental evolution of lombardy between the end of the late pleistocene and the early holocene (ravazzi et al., 2022) allowing the archaeological evidence related to the settlement of the region’s last hunter-gatherer groups to be placed within a broader environmental framework. much of the currently available mesolithic evidence derives from investigations begun in the 1970s, especially in the brescia area (biagi, 1972, 1976a, 1981, 1986; fusco, 1982; castelletti et al., 1984). in subsequent decades, investigations expanded into valcamonica (fedele, 1988; poggiani keller, 1995, 1999), valtellina (poggiani keller, 1989), valchiavenna (fedele et al., 1991), and the bergamo area (poggiani keller, 2006). the data collected made it possible to produce the first micro-regional syntheses (biagi, 1991, 1997; poggiani keller, 1992; de marinis, 1994), which were later updated with new discoveries after the 2000s (poggiani keller, 2007; baioni, 2012) and through the extension of research into additional areas (bietti, 2008; banchieri, 2009; starnini, 2017; lo vetro et al., 2022a). evidence of mesolithic human presence in lombardy spans a wide variety of environmental contexts and demonstrates a widespread, albeit heterogeneous, settlement pattern, shaped in part by the uneven intensity of research across different areas (fig. 7). while many findings derive from surface collections, some alpine contexts have been investigated stratigraphically (lo vetro et al., 2022a). only rarely archaeobotanical, faunal, and structural remains are preserved, yet the reconstruction of paleoenvironmental and settlement framework remains an important component of regional studies (scaife & biagi, 1994; ravazzi et al., 2012; pini et al., 2016; ravazzi et al., 2022; bona & poggiani keller, 2024). within the framework of mesolithic occurrences in the region, the pre-alpine and alpine area is undoubtedly the one that has yielded the largest share of evidence regarding human settlement at the beginning of the holocene (lo vetro et al., 2022a). mesolithic finds are especially numerous here particularly in the brescia region (fig. 7). these sites, occur from valley floors to elevations of 1,700-2,000 m a.s.l. on the valley floor, sauveterrian occupations are known from cemmo (400 m a.s.l.) (martini et al., 2016b) and, notablyl, from cividate camuno-via palazzo (273 m a.s.l.), which has yielded over one thousand artefacts dated to the boreal (gx18843: 8820 ±112 bp) (poggiani keller, 1996). raw materials derive both from the brescia-bergamo foothills and trentino (lo vetro et al., 2022b); traceological analyses show predominance of hunting activities (impact fractures) alongsides hides and carcasses processing (martini et al., 2016a). along the valcamonica-val trompia-val sabbia watershed, five sites have been stratigraphically investigatigated, revealing sauveterrian occupations (vaiale, 830 m a.s.l.; cascina valmaione 1, 1780 m a.s.l.; malga rondeneto, 1780 m a.s.l.), castelnovian occupations (laghetti del crestoso), or evidence from both periods (cascina valmaione 2, 1778 m a.s.l.) (biagi, 1988, 1992, 139 mesolithic settlement in upper valcamonica blages (marchand, 2014; lo vetro et al., 2022a). for sauveterrian complexes, typical elements include the exclusive use of direct percussion for knapping, operational sequences aimed at the production of flakes, laminar flakes, and irregular bladelets, and the presence of triangles, segments, and fusiform backed points (sauveterre points). castelnovian complexes, in contrast, reflect more elaborate knapping techniques, such as indirect percussion and pressure, producing more regular blades and bladelets, and are distinguished by the clear presence of trapezes, which progressively replace earlier armatures. however, the continuity of operational sequences between the two phases (fontana et al., 2023) means that in cases lacking radiometric and represented by very small assemblages, a cautious attribution to a generic mesolithic may be more appropriate. the uneven distribution of sites, mostly concentrated in the eastern lombardy (fig. 7), cannot be explained by geology or raw material availability (martino et al., 2016; bertola et al., 2021, 2022) but primarily reflects research intensity and site visibility. given the partial and heterogeneous nature of the evidence, reconstructing a comprehensive framework of mesolithic settlement in lombardy (lo vetro et al., 2022a). the alpine zone represents the part of lombardy where mesolithic settlement patterns can be reconstructed most clearly (lo vetro et al., 2022a), with sites distributed on the valley floors (500-800m), the prealpine plateaus (~ 900m), the inter-valley ridges (17002000 m), and the innermost alpine belt (2200-2350m) (fig. 7). in one of the most extensively investigated areas, namely valcamonica, the valcamonica-val trompiaval sabbia watershed, and surrounding territories (accorsi et al., 1987; biagi, 1992, 1997, 2001; biagi & starnini, 2015, 2016; baroni & biagi, 1997), recurring settlements near passes, lakes, and lookout points is evident (fig. 7). drawing on comparison from trentino (broglio, 1980), a logistical relationship has been proposed between valley-floor sites such as cividate camuno and the high-altitude site of lake ravènola, at the head of the grigna valley,a strategic location for reaching the dasdana pass and, consequently, val sabbia (biagi et al., 2017). the comparatively lower density of evidence, compared with that of the trentino and veneto regions (lo vetro et al., 2022a), has led some authors to suggest differing modes of exploiting mountain areas (fedele, 1999) and a possible chrono-cultural discontinuity in alpine land use (biagi & starnini, 2016; biagi et al., 2017). however valid, these remain hypotheses that clearly require further confirmation (lo vetro et al., 2022a). overall, the data from lombardy highlight the central role of valley systems as hubs of alpine land use and as corridors for mobility along major watersheds. the onset of the holocene appears to coincide with a reduction in territoriality among hunter-gatherer groups, reflected in subsistence strategies and operational sequences well adapted to locally available raw materials (fedele, 1999; fontana & visentin, 2016). equally significant is the evidence suggesting an intensification of social networks and inter-valley contacts within the lombard alpine arc during the mesolithic (fedele, 1999; lo vetro et al., 2022a). the results of raw materials provenance analyses of from cividate camuno seem to support this, indicating strong connections with the trentino semblage, over 200 alpine-prealpine cherts artefacts, suggesting a base camp or hunting lookout during the boreal or atlantic periods. this evidence indicates that the gavia (2621 m a.s.l.) and stelvio (2758 m a.s.l.) passes were already traversed between the preboreal and boreal (lo vetro et al., 2022a). further west, alpine sites in the inner valleys are rarer. in the bergamo area (fig. 7), sauveterrian traces occur in the brembana valley near the grotta del pusü site (650 m a.s.l.) (biagi, 1981; poggiani keller, 2006) and at mezzoldo-alpe di azzaredo (2000 m a.s.l.) (longhi et al., 2016). the latter yielded a flint and rockcrystal assemblage and was dated to the final phase of the castelnovian (ltl14817a: 7564 ±60 bp). on the border between italy and switzerland, in val chiavenna, the pian dei cavalli plateau has yielded around fifteen mesolithic sites (fedele, 2014, 2018). aat lago basso (2250 m a.s.l.) (fedele, 1999), sediments indicate that the area has been ice-free since the bølling-allerød interstadial; charcoal particles throughout the lake sequence suggests deliberate burining by mesolithic hunters between approximately 8500-7850 and 7300-6300 cal bc (vallé et al., 2022). at pian dei cavalli 1 (ca1, 2200 m a.s.l.), around forty hearths and possible temporary structures were found (fedele, 1999). lithics include rock crystal and perhaps cherts from the north could suggest contacts with val mesolcina (mesocco tec nev, switzerland) indicating cross-watershed mobility. the assemblage includes sauveterrian and castelnovian components, consistent with radiocarbon dates (8800-7400 cal bc and 6300-6000 cal bc) (lo vetro et al., 2022a). although somewhat uncertain, these dates appear to correspond to periods of open vegetation at pian dei cavalli (fedele, 1999). site ca1, like the other pian dei cavalli sites located along the northwestern slope, is interpreted as a hunting camp used for selective hunting of ecotonal fauna, perhaps deer (fedele, 1999), whereas other plateau sites may relate to specialized hunting (fur-bearing animals or birds). the occupation of pian dei cavalli 13 (ca13) has been attributed exclusively to the castelnovian, at the beginning of the atlantic (na-251: 7030 ±750 bp; na252: 7610 ±260 bp) (fedele et al., 1991), while pian dei cavalli 15 (ca15, 2258 m a.s.l.) dates to the end of the boreal (beta-385447: 8340 ±30 bp; beta-385446: 8060 ±30 bp) (fedele, 2014). in the como area, monte cornizzolo (1110 m a.s.l.) (castelletti, et al., 1984) yielded more than 2,000 artefacts in local cherts, including trapezes, sauveterre points, and triangles, indicating occupation during both mesolithic phases. also in the como area (fig. 7), in the upper breggia valley, there are sauveterrian-castelnovian attestations at erbonne-cimitero (940 m a.s.l.) and exclusively castelnovian evidence at tana d’erbonne (1045 m a.s.l.) (biagi, 1981; franco, 2011). in the varese area (fig. 7), despite the absence of trapezes, the artefacts recovered from lakes ganna and torba, in valganna (454-457 m a.s.l.), have been attributed to the castelnovian period, based on the regularity of the bladelets (biagi, 1981, 1980-81). taken together, these data confirm the wide distribution of mesolithic evidence across lombardy (fig. 7), although many sites remain poorly documented, lacking stratigraphic investigation and absolute dating. consequently, chrono-cultural attribution often relies primarily on techno-typological characteristics of the lithic assem 140 conforti j. et al. the sauveterrian. mesolithic evidence is also documented at significantly higher altitudes, around 1000 m a.s.l., as at arco pra de gom (pasquali, 1980), and even close to 2000 m a.s.l., as at monte gazza-passo s. antonio-terlago (1896 m a.s.l.) (dalmeri & pasquali, 1980) and pozza lavino (1800 m a.s.l.). the latter, located in the ledro area, has yielded evidence of occupation during both the sauveterrian and castelnovian phases (scoz et al., 2015). numerous valley-floor sites, mainly rock shelters, have been recorded along the adige valley (fig. 7), generally located at altitudes between 120 and 340 m a.s.l.. an exception is represented by bus della vecia (besenello), which is situated at a higher altitude (600 m a. s.l.) (dalmeri & pedrotti, 1994; cavulli et al., 2011; fontana et al., 2023). several sites -including major ones such as riparo soman (broglio & lanzinger, 1985 -1986), romagnano loc iii (broglio & kozlowski, 1983; fontana et al., 2016), la vela (bagolini, 1990; pedrotti, 1990), pradestel (dalmeri et al., 2008), riparo gaban (bagolini, 1980; bisi et al., 1985), galgenbühel-dos de la forca (bazzanella & weirer, 2001)-have yielded significant traces of multiple occupation dating to the sauveterrian (riparo soman, galgenbühel-dos de la forca) or to both the early and late mesolithic phases (romagnano loc iii, la vela, pradestel, riparo gaban). romagnano loc. iii, in particular, has yielded one of the most important mesolithic sequences, documenting multiple sauveterrian and castelnovian occupations (fontana, 2011; fontana et al., 2016). early mesolithic phases are dated to between the middle preboreal and the middle boreal (ca. 9300-7400 cal bc), while late mesolithic layers are dated to between ca. 6800 and 5400 cal bc (fontana et al., 2016). in the area between monte baldo and monte paganella (fig. 7), several open-air sites have been reported at altitudes between 1100 and 1750 m a.s.l. (dalmeri & pedrotti, 1994; cavulli et al., 2011; fontana et al., 2023). the lithic industries recovered from many of these sites (e.g., madonna della neve, malga artillione, and viotte costa dei cavai on monte bondone) can be broadly attributed to the mesolithic (bagolini & nisi, 1976, 1978; dalmeri & pasquali, 1980), although at least some, such as malga campo, are clearly associated with sauveterrian groups (bagolini et al., 1980; fontana, 2011). in the area between val rendena, val di non, and the maddalene group, numerous open-air mesolithic sites are known at altitudes ranging between 1238 and 2350 m a.s.l. (dalmeri & pedrotti, 1994; cavulli et al., 2011; fontana, 2011; fontana et al., 2023). only a limited number of sites can be attributed to either the sauveterrian (le regole 3, laugen ii, passo della mendola iv) or castelnovian (passo della mendola vi-vii, laugen i), whereas many others merely attest to a generic human presence during the mesolithic (niederwanger, 1981; lunz, 1986; dalmeri & pedrotti, 1994; dalmeri et al, 2004; cavulli et al., 2011; fontana, 2011; fontana et al., 2023). the lower concentration of sites in western trentino, compared to the eastern sector of the region, appears to depend mainly-at least regarding high-altitude areas-on the heterogeneity of research and, in particular, of survey activities (dalmeri & pedrotti, 1994; cavulli et al., 2011). as regards the valley floor areas, however, the greater or lesser concentration of sites seems closevalleys (lo vetro et al., 2022b). 5.2. the western sector of the south-eastern alps between the alta lessinia and the val di non starting from the beginning of the preboreal, sauveterrian human groups peopled the trentino region. the early mesolithic site distribution seems denser compared to the late upper palaeolithic groups, with sites that ranging from the adige river valley floor and the high-altitude areas situated at around 2000m asl (dalmeri & pedrotti 1994; cavulli et al., 2011; fontana et al., 2023). adige and sarca valleys form the ‘backbones’ of the region and these valleys, oriented roughly northsouth, represent a natural junction that linking the northern slope of the alps, through east-west oriented valleys such as valtellina, valpusteria, and valsugana, to other segments of the alpine chain (cavulli et al., 2011). the pre-wurmian drainage pattern was significantly different from the present one and at the alpine last glacial maximum (algm, circa 20,000 bp), trentino was almost completely subject to glacial and periglacial conditions, with glacial bodies than occupying the main adige, sarca and brenta valleys (angelucci & bassetti, 2009). the deglaciation took place between circa 16,000 and 14,500 bp at the alpine margin, and around 12,000 bp in mountain areas. human occupation reached the mid-altitude prealpine plateaux during gi1 but during the gs1 (i.e. younger dryas) cold shift caused an interruption of these trends (angelucci & bassetti 2009). starting from the early holocene, geomorphological surfaces progressively stabilized and the drainage systems reestablished equilibrium by infilling of depressions such as those at trento and valle dei laghi in the sarca drainage (angelucci & bassetti 2009). during this time span, stability and biostasy up to 2000m a.s.l. matching with the increased mesolithic presence in mountain areas. the alpine area roughly corresponding to western trentino has yielded abundant evidence of human occupation during the mesolithic (fig. 7), although numerically far fewer than those known from the eastern sector (e.g., dalmeri & pedrotti, 1994; cavulli et al., 2011; fontana et al., 2023). in the alta lessinia (fig. 7), several open-air sites have been identified at altitudes between 1181 and 1850 m a.s.l., on the folgaria plateau (bagolini & pasquali, 1985), at passo delle fittanze-ala (chelidonio & solinas, 1978), and on monte pasubio near rifugio lancia (dalmeri, 1980). these sites are generally attributed to the mesolithic (dalmeri & pedrotti, 1994; cavulli et al., 2011; fontana et al., 2023). in the near vallarsa (fig. 7), cogola rockshelter (1070 m s.l.m.) has yielded important evidence of occupation by sauveterrian groups dating to preboreal (lacogola-rc1: 10736-10563 bp) (bassetti et al., 2005; cusinato et al., 2004). in the area between lake ledro and the sarca valley (fig. 7), a series of sites is documented across a wide range of altitudes (dalmeri & pedrotti, 1994; cavulli et al., 2011; fontana et al., 2023). near arco, the rock shelter of moletta patone (95 m a.s.l.) has yielded evidence of human occupation during both the early and late mesolithic (bagolini et al., 1984). between 400 and 500 m a.s.l., the sites of terlago lago montepiana (dalmeri, 1985) and vezzano (locality of naran) (pasquali, 1985) have yielded material securely dated to 141 mesolithic settlement in upper valcamonica that emerged for mondeval de sora indicate that, whereas during the sauveterrian raw material exploitation mainly reflects a connection with the piave valley floor, during the castelnovian the supply area expanded both eastward and westward (fontana et al., 2020). this expansion likely aimed at acquiring higher-quality cherts suitable for more sophisticated knapping techniques, such as indirect percussion and pressure flaking (fontana et al., 2020). only targeted research will clarify whether similar trends can also be identified at sites surrounding the atesino basin. regarding the techno-typological aspects of knapped lithic industries, sauveterrian technology persisted into the late mesolithic, as shown by the stratigraphic sequence of romagnano loc iii, where the opportunistic use of direct percussion and bipolar flaking -particularly during the final stages of core reduction-is documented within castelnovian layers (fontana et al., 2016). this continuity is also reflected in osseous equipment and settlement choices (fontana et al., 2023). evidence related to bladelet production and arrowhead manufacture at romagnano loc iii indicates the onset of the late mesolithic with the layer ab, at the base of the castelnovian sequence, where the first trapezoidal armatures appear together with the production of more regular bladelets through the adoption of new knapping techniques. within the same stratigraphic sequence, trapeze manufacturing techniques suggest a possible change between layers ab and aa, while the presence of sauveterrian microliths decreases over time (fontana et al., 2023). open-air sites likewise document the persistence of typical sauveterrian microliths during the castelnovian (fontana et al., 2023). the major innovations associated with the transition between the early and late mesolithic, at the onset of the atlantic period, correspond to the diffusion of new lithic technologies. available evidence indicates that these innovations originated outside the region and were progressively incorporated into pre-existing cultural traditions (fontana et al., 2023). 6. material 6.1. the knapped lithic artefacts of tor dei pagà only four knapped lithic artefacts have been recovered from tor dei pagà (fig. 8). although these were recovered from within medieval layers, they almost certainly originated from the yellowish-brown deposit at the base of the stratigraphic sequence. the assemblage includes a small, exhausted core, a laminar flake, and two fragmentary products, at least one of which can be securely identified as a bladelet fragment. no retouched tools were recovered, but all pieces were subjected to technological analysis (inizan et al., 1995) to identify elements useful for their chronocultural assessment. to date, none of the tor dei pagà knapped lithic artefacts have undergone specific analyses to determine raw material provenance; this information is expected to be obtained through forthcoming petrographic studies aimed at evaluating their possible derivation from one or more of the chert-bearing geological formations of the lombard prealpine arc (bertola et al., 2021, 2022). the small, exhausted core (26 × 26 × 7 mm) made of grey chert, displays an irregular quadrangular morphology (fig. 8-1). it appears to result from the opportunistic recycling of a flake blank through bipolar percusly linked to their visibility; in fact, these, in most cases covered by meters of sediment, emerge, as in the case of the trento area, only in conjunction with building expansions or where mining activities are concentrated (dalmeri & pedrotti, 1994). two of the most problematic issues are the shorter chronological depth of the castelnovian (ca. 6700-5000 cal bc) compared to the sauveterrian (ca. 9500-6700 cal bc), and the cultural attribution of sites to one of these technocomplexes, which, for surface lithic assemblages, is exclusively based on techno-typological features (dalmeri & pedrotti, 1994; fontana et al., 2023). moreover, at sites where both phases are attested, natural and anthropogenic agents could be responsible for erosive processes, which may have mostly affected castelnovian layers (fontana et al., 2023). analysis of the available evidence suggests that altitude represents a key variable for understanding human settlement trends between the late upper palaeolithic and the mesolithic. while palaeolithic sites are generally located at mid-elevations (1000-1600 m asl), mesolithic sites are distributed across three main elevation ranges: low (95-594 m asl), middle (1000-1238 m asl), and high (1773-2000 m asl) (dalmeri & pedrotti, 1994; cavulli et al., 2011). during both the early and late mesolithic, settlement strategies display substantial continuity, with repeated occupation of the same territories and exploitation of similar ecological niches (fontana et al., 2023). regarding evidence related to game exploitation, a wide variety of species can be observed (fontana et al., 2023). valley-bottom sites display the most comprehensive faunal spectra, including species associated with humid environments such as beaver, fish, and molluscs. ungulates also play a significant role, with a diachronic decrease in capra ibex and a corresponding increase in red deer (fontana et al., 2023). these two ungulates become increasingly important at high-altitude sites; however, in some valley-bottom contexts red deer is replaced as the dominant species by roe deer and wild boar (fontana et al., 2023). this pattern is closely linked to the expansion of forested environments during the boreal and atlantic periods (cattani, 1994; drescherschneider, 2009). settlement strategies and population patterns, at least during the sauveterrian, appear to have been primarily linked to subsistence activities and the broad exploitation of resources available in the alpine environment, rather than to the presence of chert outcrops (cavulli & grimaldi, 2009). indeed, many sites are located more than 40 km from the nearest potential chert source. sauveterrian raw material exploitation appears flexible and opportunistic, mainly aimed at optimising available lithic resources with relatively few technical constraints (fontana et al., 2023). in western trentino, early mesolithic groups exploited the numerous chertbearing formations located along the adige valley, between alta lessinia and val di non (bertola & cusinato, 2005; barbieri et al., 2013), closely linked to seasonal mobility that developed preferentially along this same hydrographic basin (broglio, 2016; fontana et al., 2023). while lithic raw material procurement systems have been extensively investigated for sauveterrian groups in trentino, far fewer data are available for the castelnovian, making it more difficult to advance hypotheses regarding raw material supply for this phase (fontana et al., 2023). if we look at the belluno dolomites, the data 142 conforti j. et al. the mesial fragment of a bladelet (4 mm wide, 2 mm thick) in yellow-orange chert is rather irregular (fig. 8-4). a naturally backed surface with cortical residues along the left edge indicates that it represents a lateral product removed from the side of the core’s debitage surface (fig. 8-4). both fragments show no patinas, edge damage or ridge rounding. 7. discussion although the knapped lithic artifacts found at tor dei pagà are extremely few in number and no retouched tools are present, they nonetheless display useful elements for hypothesizing their chrono-cultural attribution and for contextualizing their presence within the site. the four pieces were recovered in secondary position within the medieval occupation layers; however, the absence of physical alterations on the edges and ridges suggests that they underwent only limited spatial displacement from their original context and little to no exposure to processes such as trampling or weathering. by contrast, there is no clear evidence to establish whether the slight thermal alteration-most likely involuntary-observed on the small, exhausted core preceded or followed the redeposition of the artifacts within the medieval layers. despite its very small size and the absence of formally diagnostic tools, the tor dei pagà lithic assemblage can nonetheless be confidently assigned to the sion, with part of the ventral surface still visible on one of the two faces of the residual core (fig. 8-1). one face preserves a series of non-standardized unipolar removals, while the opposite face shows at least two series of opposing bipolar negatives (also non-standardized) indicating that the striking and resting platforms were rotated by at least 90°, and possibly up to 180° (fig. 8-1). slight discoloration and small thermal detachments suggest that the artifact was exposed to fire. the ridges between the negatives do not show rounding. the laminar flake (17 × 10 × 2 mm) in red-orange chert is sub-triangular in shape (fig. 8-2). the thin blank has a small faceted, prepared platform (fig. 8-2) with a flaking angle between 80° and 90°, and only a weakly developed the bulb. these features indicate production by direct freehand percussion, probably using a soft lithic hammerstone. the negatives are convergent and unipolar, and the profile is slightly twisted (fig. 8-2) suggesting removal from a core with unipolar detachments and a debitage surface showing some transverse convexity. this flake could derive from a reduction sequence specifically aimed at producing elongated flakes, or it might represent a secondary product from bladeletoriented reduction that integrated both bladelet and flake production. the piece shows no patinas, edge damage or ridge rounding. the other piece (fig. 8-3), 2 mm thick and without cortex, is compatible with an elongated blank but is too fragmentary to offer substantial information. 143 fig. 8 tor dei pagà lithic industry. n. 1: exhausted core exploited by bipolar knapping, n.2: laminar flake, n. 3 flake/bladelet fragment, n. 4 natural backed bladelet mesial fragment (artefacts photos: f. bona, graphic elaboration: j. conforti). mesolithic settlement in upper valcamonica vated strategic points, passes, lakes, and lookout areas, documented throughout the region (lo vetro et al., 2022a). these settings are commonly associated with subsistence hunting activities and possibly also with broader mobility patterns linking different valleys. as suggested by several authors (fedele, 1999; lo vetro et al., 2022a, 2022b) such mobility may reflect the intensification of social networks and inter-valley contacts, including connections with the western sector of trentino area (dalmeri & pedrotti, 1994; cavulli et al., 2011; fontana, 2011; fontana et al., 2023). in this sense, even a minimal assemblage such as that from tor dei pagà provides meaningful evidence, reinforcing the emerging picture of early holocene occupation in the alpine arc between lombardy and western trentino and contributing to our understanding of how mesolithic groups exploited high-altitude environments. 8. conclusion the data presented in this paper allow a reassessment of the mesolithic presence at tor dei pagà and highlight key directions for future research aimed at clarifying this early phase of occupation: the four knapped lithic artifacts with mesolithic characteristics recovered from within the medieval levels at tor dei pagà undoubtedly attest to the presence of hunter-gatherer groups at the site from at least the beginning of the holocene. although limited in number, these artifacts nonetheless provide valuable insights into the mesolithic occupation of the high-altitude areas of lombardy and fit well within the broader framework of human settlement in the western sector of the eastern alps during the early holocene. it remains possible that subsequent occupations during the iron age and the late middle ages may have partially or entirely disturbed, or even destroyed, traces of the mesolithic presence. given the characteristics of the lithic assemblage and the absence of distinctive techno-typological elements, it is not yet possible to assign the mesolithic evidence at tor dei pagà more precisely to either the sauveterrian or the castelnovian cultural facies. continued research at the site will be essential to test the hypotheses regarding the original stratigraphic provenance of the recovered lithic artifacts. further investigations may also expand the availabledataset for this phase, ideally yielding additional lithic artifacts and materials suitable for radiometric dating (e.g., charcoal, hearth resideus), thereby contributing to a more refined chrono-cultural interpretation of the site’s mesolithic occupation. acknowledgement we would like to thank those who have made the vione archeologica project, which is the basis of the results reported here, possible. in particular, comune di vione (especially mauro testini and luigi sterli), unione dei comuni di alta valle camonica, the comunità montana di valle camonica and parco nazionale dello stelvio who support the excavation campaign at the tor dei pagà site every year. we thank soprintendenza archeologia belle arti e paesaggio per le province di bergamo and brescia (andrea breda and serena solamesolithic, and most plausibly to the sauveterrian tradition (marchand, 2014; lo vetro et al., 2022a; fontana et al., 2023). the attribution to the mesolithic rather than to earlier paleolithic phases or to more recent holocene human presences, results from the convergence of both contextual and technological indicators. on the one hand, the environmental and geographical setting of the site, its high-altitude position within the lombard alpine arc and its proximity to well-documented mesolithic routes and activity zones, is fully consistent with the spatial patterning documented for sauveterrian groups in this area (lo vetro et al., 2022a). technologically, several traits observed in the artefacts, such as the characteristics of the laminar flake, the morphology of the exhausted core, and the production attributes of the bladelet fragment, are consistent with operational sequences commonly associated with early mesolithic knapping strategies. the evidence of direct and bipolar on anvil percussion, the poor regularity of laminar products, and the absence of indications of more elaborate techniques such as indirect percussion and pressure are insufficient, based on only four artefacts and in the absence of absolute dating, to support a clear attribution to the sauveterrian (marchand, 2014; fontana et al., 2023). the use of direct percussion, soft hammerstones, the production of laminar flakes, and the application of bipolar on anvil percussion during the residual phases of exploitation are, in fact, technological features shared by both the sauveterrian and castelnovian (fontana et al., 2023). based on these observations, the few knapped lithic artifacts recovered at tor dei pagà most likely date to a mesolithic occupation of the site. an attribution to the late-final epigravettian (lo vetro et al., 2022a) or to more advanced phases of the holocene, such as the neolithic or eneolithic (scoz et al., 2015; pedrotti et al., 2022; poggiani keller & baioni, 2022), cannot be entirely excluded; however, it appears highly unlikely in light of the settlement dynamics documented for the lombard alpine arc during these periods and the absence of other diagnostic evidence among the materials from tor dei pagà. in the absence of absolute dates and more diagnostic techno-typological indicators, while a sauveterrian attribution remains plausible, it is considered more prudent at present to assign the few knapped lithic artifacts from tor dei pagà to a generic mesolithic framework. 7.1. the mesolithic presence at tor dei pagà within the early holocene human occupation of the lombard pre-alpine-alpine arc and western trentino the small number of knapped lithic artefacts recovered at tor dei pagà (2,250 m a.s.l.) in upper valcamonica fits well within the broader framework of mesolithic alpine settlement known in lombardy, particularly in the valcamonica-val trompia-val sabbia area (e.g., biagi & starnini, 2015; lo vetro et al., 2022a), where numerous high-altitude sites attributed to both the sauveterrian and castelnovian periods have been identified (fig. 7). given the extremely small number of artefacts and the lack of absolute dating, these observations cannot, on their own, support a definitive assignment to the sauveterrian. nevertheless, the tor dei pagà evidence fits perfectly within the high-altitude settlement model reconstructed for the mesolithic in lombardy. the location of the site corresponds to the recurrent use of ele 144 conforti j. et al. bassetti m., degasperi n. (2017) indagini archeologiche sulle stratificazioni di epoca protostorica. un brandopferplatz in alta valle camonica. in: “tor dei pagà: protostoria e medioevo di un sito d'alta quota. indagini archeologiche 2011-2017”, bellandi g., sannazaro m. ed., 268-286. bassetti m., dalmeri g., peresani m. (2005) riparo cogola. note preliminari sulla successione stratigrafica. preistoria alpina, 40, 99-105. bazzanella f., wierer u. (2001) die mesolithische fundstelle am galgenbühel in salurn, südtirol: eine sauveterrienstation im etschtal. der schlern, 75, 116-128. bellandi g. (2017) memoria storica e prime indagini archeologiche. in: “tor dei pagà: protostoria e medioevo di un sito d'alta quota. indagini archeologiche 2011-2017”, bellandi g. & sannazaro m. ed., 17-52. bellandi g., cesana d., fanetti d., scippa a., vignola m. (2015) la fortificazione di tor dei pagà a vione (valcamonica, brescia). risultati delle campagne archeologiche 2011-2014. archeologia medievale, 42, 95-118. bellandi g, fanetti d., scippa a. (2017) le indagini di scavo. in: “tor dei pagà: protostoria e medioevo di un sito d'alta quota. indagini archeologiche 20112017”, bellandi g., sannazaro m. ed., 91-114. bertola s., cusinato a. (2005) le risorse litiche dell’altopiano di folgaria e il loro utilizzo a riparo cogola. preistoria alpina, 40, 107-123. bertola s., lo vetro d., schirolli p., confortini f., malzanni m., pallecchi p. (2021) chert exploitation and circulation in east lombardy (northern italy). a diachronic overview trough prehistory, uispp journal 3, 1, 1-20. doi: 10.62526/m85be9 bertola s., lo vetro d., schirolli p., confortini f., malzanni m., pallecchi p. (2022) le risorse litiche scheggiabili delle prealpi della lombardia centroorientale: primi dati per una caratterizzazione degli areali di approvvigionamento delle materie prime usate durante la preistoria. rivista di scienze preistoriche lxxii s2, preistoria e protostoria in lombardia e canton ticino, 217-237 biagi p. (1972) il giacimento sopra fienile rossino sull’altopiano di cariàdeghe (serle, brescia), natura bresciana, 8, 177-197. biagi p. (1976a) stazione mesolitica a provaglio d’iseo. natura bresciana, 13, 75-92. biagi p. (1976b) laghi di ravènole e laghetto dasdana (brescia). preistoria alpina, 12, 262-263. biagi p. (1980-81) stazioni mesolitiche presso i laghi di ganna e torba in valganna. archivio storico della badia di san gemolo in valganna xi-xi,167170. biagi p. (1981) introduzione al mesolitico della lombardia. in atti del 1° convegno archeologico regionale, 1, 55-76. biagi p. (1983) segnalazione di industria mesolitica a trapezi dal riparo 2 di foppe di nadro in valcamonica. bollettino del centro camuno di studi preistorici, 20, 117119. biagi p. (1985) le più antiche presenze umane. in berruti g. ed. laghi alpini del bresciano. editoriale ramperto, 107-111. biagi p. (1986) stazione mesolitica a lonato (bs), no) that make research possible and università cattolica del sacro cuore (prof. marco sannazaro) who collaborates in the management of the excavation and is involved in the research. we also thank regione lombardia for its support. references accorsi c.a., bandini mazzanti m., biagi p., castelletti l, cremaschi m., leoni l., pavarani m. (1987) il sito mesolitico sopra fienile rossino sull’altipiano di cariàdeghe (serle, brescia). aspetti pedostratigrafici, archeologici, antracologici e palinologici. natura bresciana, 23, 239-292. alexander c. (2017) la funzione della torre b. in: “tor dei pagà: protostoria e medioevo di un sito d'alta quota. indagini archeologiche 2011-2017”, bellandi g., sannazaro m. ed., 119-122. angelucci d.e., bassetti m. (2009) humans and their landscape from the alpine last glacial maximum to the middle holocene in trentino: geoarchaeological considerations, preistoria alpina, 44, 59-78. angelucci d., cremaschi m., negrino f., pelfini e. (1994). il sito mesolitico di dosso gavia val di gavia (s. caterina valfurva, so): evoluzione ambientale e popolamento umano durante l'olocene antico nelle alpi centrali. preistoria alpina, 28(1), 19-32. bagolini b. (1980) il trentino nella preistoria del mondo alpino. ed. temi, trento. bagolini b. (1990) cultura dei vasi a bocca quadrata . il sepolcreto neolitico de la vela di trento. die ersten bauern, 2, 225-231. bagolini b., nisi d. (1976) monte baldo (verona trento). preistoria alpina, 12, 237-241. bagolini b., nisi d. (1978) passo sella (trento). preistoria alpina, 14, 232-233. bagolini b., nisi d. (1980) passo gavia (sondrio). notiziario extraregionale 1980-1981. preistoria alpina, 16, 145. bagolini b., pasquali t. (1985) lagorai cima d'asta. preistoria alpina, 21, 238-260. bagolini b., nisi d., tonelli l. (1978) malga dell’alpe, passo gavia (sondrio). preistoria alpina, 14, 275. bagolini b., nisi d., loss d. (1980) malga campo brentonico (trento). preistoria alpina, 16, 85. bagolini b., pasquali t., zampedri m. (1984) testimonianze epigravettiane nella piana della marcésina altopiano dei sette comuni. preistoria alpina, 21, 11-20. baioni m. (2012) il paradiso perduto. il paleolitico e il mesolitico. in archeologia nella lombardia orientale. i musei della rete ma_net e il loro territorio, 4160. banchieri d.g. (2009) la preistoria del territorio di varese. in de marinis r.c, massa s., pizzo m. eds. alle origini di varese e del suo territorio. roma, 310. barbieri s., avanzini m., grimaldi s. (2013) la selce nel bacino atesino meridionale: caratterizzazione e diffusione. preistoria alpina, 47, 27-37. baroni c., biagi p. eds. (1997) excavations at the high altitude mesolithic site of laghetti del crestoso (bovegno, brescia-northern italy). ateneo di brescia, accademia di scienze, lettere ed arti (brescia 1997). 145 mesolithic settlement in upper valcamonica sary. verlag dr. rudolf habelt gmbh, bonn, 293, 33-40. biagi p., starnini e., nisbet r. (2017) rondeneto: a high altitude sauveterrian camp in the central italian alps and the boreal mesolithic settlement pattern in the region. in margarit m., boroneant a. eds. from hunter-gatherers to farmers. human adaptations at the end of the pleistocene and the first part of the holocene. targoviste: ed. cetatea de scaun, 367-384. biancardi b. (2022) fondamenti historiali del forte e antico castello di vione e della sua comunità. giarelli l. ed. (transcriptions by c. riva). youcanprint, vione, pp. 266. bietti a. (2008) i recenti rinvenimenti di materiali paleolitici nell’area di monte faita tra muscoline e gavardo (brescia). in mottes e., nicolis f., zontini g. eds. archeologia lungo il chiese. nuove indagini e prospettive della ricerca preistorica e protostorica in un territorio condiviso fra trentino e lombardia, atti del 1° convegno interregionale, storo 24-25 ottobre 2003, 15-23. bisi f., broglio a., dalmeri g., lanzinger m., sartorelli a. (1985) les bases mésolitiques du néolithique ancien au sud des alpes. in kozlowski j.k., koslowski s.k. (eds) chipped stone industries of the early farming cultures in europa , archeologia interregionalis, university warzawa, university cracow, 33-48. bona f. poggiani keller r. (2024) hunter-gatherers between the late glacial and the beginning of the holocene in northwestern italy: animal exploitation at cividate camuno (valle camonica lombardy, brescia). quaternary international, 691, 8-17. doi: 10.1016/j.quaint.2024.02.012 broglio a. (1980) culture ed ambienti della fine del paleolitico e del mesolitico nell’italia nordorientale, preistoria alpina, 16, 7-29. broglio a. (2016) the discovery of the mesolithic in the adige valley and the dolomites (north-eastern italy): a history of research. quaternary international, 423, 5-8. doi: 10.1016/j.quaint.2015.08.085 broglio a., kozlowski s.k. (1983) tipologia ed evoluzione delle industrie mesolitiche di romagnano iii. preistoria alpina, 19, 93-148. broglio a., lanzinger m. (1985-1986) risultati preliminari degli scavi al riparo soman presso ceraino in val d'adige. annuario storico della valpolicella, 928. bugini r., folli l. (2017) indagini mineralogiche su campioni di malta. in: “tor dei pagà: protostoria e medioevo di un sito d'alta quota. indagini archeologiche 2011-2017”, bellandi g., sannazaro m. ed., 151-154. castelletti l., d’errico f., leoni l. (1984) il sito mesolitico di monte cornizzolo (prealpi lombarde occidentali). preistoria alpina, 19, 213-220. castiglioni e., cottini m., fanetti d. (2017) i macroresti botanici della fase medievale. in: “tor dei pagà: protostoria e medioevo di un sito d'alta quota. indagini archeologiche 2011-2017”, bellandi g., sannazaro m. ed., 235-246. castiglioni e., cottini m. (2017) i macroresti botanici della fase protostorica. in: “tor dei pagà: protostolocalità case vecchie. natura bresciana, 22 (1985), 179-190. biagi p. (1988) una stazione epipaleolitica/mesolitica iniziale sullo spartiacque val trompia valcamonica (brescia). natura bresciana, 25(1989), 376377. biagi p. (1991) i primi abitatori. in simoni c. ed. atlante del garda. uomini, vicende, paesi, 1. grafo edizioni, brescia, 133-141. biagi p. (1992) mesolithic exploitation of the highland zone: a case study for the southern alps. preistoria alpina, 28(1)(1994), 367-372. biagi p. (1993) il mesolitico in provincia di brescia: ricerche e scavi lungo lo spartiacque della val sabbia, valtrompia e valcamonica. commentari dell’ateneo di brescia, 29-50. biagi p. (1997) recenti ricerche sul mesolitico della valcamonica (brescia). bollettino del centro camuno di studi preistorici, 30, 23-39. biagi p. (1998) prospezioni e ricerche su uno spartiacque delle alpi meridionali: gli effetti dell’impatto antropico fra l’inizio dell’olocene e il medioevo. saguntum, 31(1999) 117-124. biagi p. (2001) some aspects of the late mesolithic and early neolithic periods in northern italy. in from the mesolithic to the neolithic. in kertesz r., makkay j. eds. proceedings of the international archaeological conference. szolnok, 71-88. biagi p. (2002) le stazioni preistoriche del monte guglielmo (gölem) e del monte ario in val trompia (brescia). commentari dell’ateneo di brescia, 223249. biagi p., nisbet r. (2008) gli scavi nella stazione preistorica di vaiale in valle sabbia (lavenone, brescia). in mottes e., nicolis f., zontini g. eds. archeologia lungo il chiese. nuove indagini e prospettive della ricerca preistorica e protostorica in un territorio condiviso tra trentino e lombardia. atti del 1° convegno interregionale. provincia autonoma di trento, trento, 25-35. biagi p., castelletti l., cremaschi m., sala b., tozzi c. (1979) popolazione e territorio nell’appennino tosco-emiliano e nel tratto centrale del bacino del po tra il ix ed il v millennio a.c. emilia preromana, 8, 13-36. biagi p., nisbet r., scaife r. (1994) man and vegetation in the southern alps: the valcamonicavaltrompia-valsabbia watershed (northern italy). in biagi p., nandris j. eds. highland zone exploitation in southern europe. monografie di natura bresciana, 20, 133-142. biagi p., nisbet r., scaife r. (1995) hunter-foragers subsistence and settlement in a southern alpine watershed. porocilo o raziskovanju paleolitika, neolitika in eneolitika v sloveniji xxii, 219-232. biagi p., starnini e. (2015) human settlement and environmental exploitation of valcamonicavaltrompia watershed from the beginning of the holocene to the middle ages. natura bresciana, 39, 249-259. biagi p., starnini e. (2016) the exploitation of the highland zone: the earliest mesolithic hunters of the central alpine arc. in bacvarov k., gleser r. eds. southeast europe and anatolia in prehistory. essays in honor of vassil nikolov on his 65th anniver 146 conforti j. et al. 20,000 anni al castello di breno. catalogo della mostra fotografica. boario terme (bs), brescia, pp. 267. fedele f. (1999) economy and territory of high altitude mesolithic land-use: the central alps, in della casa p. ed. prehistoric alpine environment and society. papers of the international colloquium paese, zurich 1997. universitätsforschungen zur prähistorischen archäologien 55. bonn, 25-36. fedele f. (2014) nuove date radiocarboniche per l’archeologia preistorica e storica della valle spluga: pian dei cavalli, borghetto, mottaletta. clavenna, 53, 9-32. fedele f. (2018) pian dei cavalli: inventare le alpi, “noi” e “loro”. iubilantes annuario, 22, 20-38. fedele f., campajola l., cascini a., de matteis f., gialanella p.r., godio a., incoronato a., ranieri g., romano m., sambuelli l., terrasi f., wick l. (1991) preistoria e paleoambienti della valchiavenna: pian dei cavalli 1991. clavenna, 30, 9122. fontana f. (2011) from season to season: a revision of the functional status of sauveterrian sites in the north eastern sector of the italian peninsula and implications for the mobility of human groups, in bon f., costamagno s., valdeyron n. (eds.), hunting camps in prehistory. current archaeological approaches, proceedings of the international symposium, may 13-15 2009, university toulouse ii le mirail, p@lethnology, 3, 291-308. fontana f., visentin d. (2016) between the venetian alps and the emilian apennines (northern italy): highland vs. lowland occupation in the early mesolithic. in fontana f., visentin d., wierer u. eds. proceedings of the international conference mesolife. selva di cadore 11-14 june 2014, quaternary international, 423, 266-278. doi: 10.1016/j.quaint.2015.12.014 fontana f., flor e., duches r. (2016) technological continuity and discontinuity in the romagnano loc iii rock shelter (ne italy) mesolithic series. in fontana f., visentin d., wierer u. eds. proceedings of the international conference mesolife. selva di cadore 11-14 june 2014, quaternary international, 423, 252-265. doi: 10.1016/j.quaint.2015.10.046 fontana f., cristiani e., bertola s., briois f., guerreschi a., ziggiotti s. (2020) a snapshot of late mesolithic life through death: an appraisal of the lithic and osseous grave goods from the castelnovian burial of mondeval de sora (dolomites, italy). plos one, 15(8), e0237573. doi: 10.1371/journal.pone.0237573 fontana f., visentin d., bertola s., cristiani e., dipino n., flor e., fontana a. (2023) investigating the early-to-late mesolithic transition in northeastern italy: a multifaceted regional perspective. open archaeology 2023, 9, 20220284. doi: 10.1515/opar-2022-0284 franco c. (2011) la fine del mesolitico in italia. identità culturale e distribuzione territoriale degli ultimi cacciatori-raccoglitori. quaderno 13. trieste: società per la preistoria e la protostoria della regione friuli-venezia giulia, pp. 280. fusco v. (1982) ricerche preistoriche nel territorio di angera. studi in onore di mario bertolone, assoria e medioevo di un sito d'alta quota. indagini archeologiche 2011-2017”, bellandi g., sannazaro m. ed., 235-246. cattani l. (1994) prehistoric environments and sites in the eastern alps during the late glacial and postglacial. preistoria alpina, 28(1992), 61-70. cavulli f., grimaldi s. (2009) raw material and settlement strategies at the pleistocene/holocene boundary in trentino (north-eastern italian alps): a gis approach. in: mccartan s., schulting r., warren c., warren p. (eds.) mesolithic horizons. papers presented at the seventh international conference on the mesolithic in europe, belfast 2005, oxbow books, oxford, uk, 96-101. cavulli f., grimaldi s., pedrotti a., angelucci d.e. (2011) toward a comprehension of archaeological visibility: the case study of the trentino region (southern alps). in: leusen m., van sarti l., pizziolo g. (eds.), hidden landscapes of mediterranean. europe. cultural and methodological biases in preand protohistoric landscape studies. proceeding of the international meeting. siena, italy, may 25-27. bar international series, 2320. archeopress, oxford, 83-94. chelidonio g., solinas a. (1978) passo delle fittanzeala (trento). preistoria alpina, 14, 228-231. cusinato a., dalmeri g., kompatscher k., hroznykompatscher m. (2004) gli insiemi litici della sequenza preistorica di riparo cogola e la problematica relativa alla transizione tra epigravettiano e mesolitico in area alpina. preistoria alpina, 40, 125-154. dalmeri g. (1980) m. pasubio rif. lancia (trento). preistoria alpina, 16, 92. dalmeri g. (1985) l'arte mobiliare dell'abitato tardopaleolitico-rnesolitico di terlago. preistoria alpina, 21, 21-31. dalmeri g., pasquali t. (1980) monte gazza-paganella (trento). preistoria alpina, 16, 80-82. dalmeri g., pedrotti a. (1994) distribuzione topografica dei siti del paleolitico superiore finale e mesolitico in trentino alto-adige e nelle dolomiti venete (italia). prestoria alpina, 28, 247-267. dalmeri g., kompatscher k., hrozny kompatscher m., bassetti m., cusinato a., piazzi o., (2004) dinamiche comportamentali degli ultimi cacciatori raccoglitori in area alpina. il caso di studio del sito lr3 del laghetto delle regole, preistoria alpina, 40, 5-26. dalmeri g., cusinato a., neri s., nicolodi f. (2008) le industrie mesolitiche di riparo pradestel (trento). aspetti tipologici ed evolutivi. preistoria alpina, 43, 131-186. de marinis r.c. (1994) preistoria e protostoria del territorio di lecco. dal paleolitico alla fine dell’età del bronzo. in casini s. ed. carta archeologica della lombardia. la provincia di lecco. 1994, modena, 18-80. drescher-schneider r. (2009) la storia forestale delle alpi sud-orientali e del margine pedemontano durante gli ultimi 25 mila anni. in m. peresani & c. ravazzi (eds.), le foreste dei cacciatori paleolitici. ambiente e popolamento umano in cansiglio tra tardoglaciale e postglaciale, 27-64. fedele f. (1988) l’uomo, le alpi, la valcamonica: 147 mesolithic settlement in upper valcamonica pedrotti a. (1990) l'abitato neolitico de la vela di trento. die ersten bauern 2, 219-224. pedrotti a., poggiani keller r., banchieri d., longhi c. (2022) il neolitico in lombardia. rivista di scienze preistoriche lxxii s2, preistoria e protostoria in lombardia e canton ticino, 123-166. pini r., ravazzi c., aceti a., castellano l., perego r., quirino t., vallè f. (2016) ecological changes and human interactions in valcamonica, the rock art valley, since the last deglaciation. alpine and mediterranean quaternary, 29(1), 19-34. poggiani keller r. (1989) valtellina e mondo antico nella preistoria. catalogo della mostra, milano 31 ottobre7 dicembre 1989. modena, pp. 191. poggiani keller r. (1992) aspetti culturali, insediativi, funerari tra paleolitico ed età del ferro. in poggiani keller r. ed. carta archeologica della lombardia. ii. la provincia di bergamo, modena, 67-114. poggiani keller r. (1995) museo archeologico della valcamonica (cividate camuno, brescia). in aspes a. ed. italia padana e centro-alpina. guide archeologiche. preistoria e protostoria in italia, 5, forlì, 1995, abaco, 195-201. poggiani keller r. (1999) resti insediativi del paleolitico superiore e del mesolitico nel centro urbano di cividate camuno in valcamonica (brescia-italia). in della casa p. ed. prehistoric alpine environment, society and economy, papers of the international colloquium “paese ‘97”, zurich 1997, universitätsforschungen zur prähistorischen archäologie, 55, 119-121. poggiani keller r. (2006) tracce del mesolitico. storia economica di bergamo, i.i. i primi secoli. bergamo, 74-75. poggiani keller r. (2007) stato degli studi e delle ricerche. in fortunati m., poggiani keller r. eds. storia economica e sociale di bergamo. i primi millenni: dalla preistoria al medioevo, 1, 57-67. poggiani keller r., baioni m. (2022) l’età del rame in lombardia. rivista di scienze preistoriche lxxii s2, preistoria e protostoria in lombardia e canton ticino, 253-270. ravazzi c., badino f., marsetti d., patera g., reimer p.j. (2012) glacial to paraglacial history and forest recovery in the oglio glacier system (italian alps) between 26 and 15 kyr cal bp. quaternary science reviews, 58, 146-161. doi: 10.1016/j.quascirev.2012.10.017 ravazzi c., artioli g., badino f., baioni m., banino r., castellano l., castelletti l., chiesa s., colombaroli d., comolli r., cremaschi m., croce e., dal corso m., dal sasso g., deaddis m., de amicis m., ferrario m.f., fontana f., furlanetto g., garozzo l., livio f., mangani c., marchetti m., martinelli e., michetti a.m., motella de carlo s., nicosia c., perego r., peresani m., pini r., poggiani keller r., quirino t., rapi m., rottoli m., ruggiero m.g., tinner w., tramelli a., trentacoste a., vallé f., visentin d., wick l., zanon a., zerboni a. (2022) scenari di ricostruzione delle interazioni uomo-ambienteclima in lombardia (nitalia) dal paleolitico medio all’età del ferro. rivista di scienze preistoriche lxxii s2, preistoria e protostoria in lombardia e canton ticino, 9-36. reimer p.j., austin w., bard e., bayliss a., blackwell ciazione storica ed archeologica m. bertolone, varese, 1-38. inizan m.-l., reduron-ballinger m., roche h., tixier j. (1995) technologie de la pierre taillee: suivi par un vocabulaire multilingue. vol. 4. crep, pp. 199. longhi c., redaelli m., tremari m. (2016) sulle tracce dei cacciatori mesolitici all’alpe di azzaredo, mezzoldo. quaderni brembani, 14, 50-53. lo vetro d., fontana f., arzarello m., martini f. (2022a) il paleolitico e il mesolitico in lombardia. rivista di scienze preistoriche lxxii s2, preistoria e protostoria in lombardia e canton ticino, 77-110 lo vetro d., bertola s., poggiani keller r., martini f. (2022b) le industrie litiche paleolitiche e mesolitiche di cividate camuno (valle camonica, brescia): sistemi tecnici e materie prime. rivista di scienze preistoriche lxxii s2, preistoria e protostoria in lombardia e canton ticino, 837-844 marchand g. (2014) beyond the technological distinction between the early and late mesolithic. in henry a., marquebielle b., chesnaux l., michel s. eds. techniques and territories: new insights into mesolithic cultures, proceedings of the round table, november 22-23 2012, maison de la recherche, toulouse (france), palethnology, 6, 9-22. doi: 10.4000/palethnologie.1107 martinelli n., pignatelli o. (2017) la datazione del legno. in: “tor dei pagà: protostoria e medioevo di un sito d'alta quota. indagini archeologiche 20112017”, bellandi g., sannazaro m. ed., 157-160. martini f., baglioni l., magri f., mazzucco n., poggiani keller r. (2016a) mesolithic frequentation at cividate camuno via palazzo (brescia italy). preistoria alpina, 48, 93-101. martini f., lo vetro d., timpanelli l., magri f., poggiani keller r. (2016b) mesolithic findings from the area of the engraved boulders at cemmo (lombardia, italia), preistoria alpina, 48, 89-92. martino g., lo vetro d., trenti f., pallecchi p., livio f., rigamonti i., banchieri d. (2016) les ressources siliceuses de lombardie occidentale: affleurements, caractérisation et premières notions sur la gitologie régionale. in tomasso a., binder d., martino g., porraz g., simon p., naudinot n. eds. ressources lithiques, productions et transferts, séances de la société préhistorique française, 5, 77-96. marzatico f. (2017) la documentazione ceramica del rogo votivo (brandopferplatz). in: “tor dei pagà: protostoria e medioevo di un sito d'alta quota. indagini archeologiche 2011-2017”, bellandi g., sannazaro m. ed., 287-298. mirabella roberti m. (1987). presenze di età longobarda a vione in valcamonica. in: convivium. raccolta di scritti in onore di davide pace, villa di tirano, 133140. lunz r. (1986) vorund frtihgeschichte stidtirols. band l steinzeit, bruneck, pp. 59. niederwanger g. (1991) steinfunde auf dem mendelkamm 1m memoriam adolf moller. der schlern, 65 (11/12), 608-628. pasquali t. (1980) val duron val di fassa (trento). preistoria alpina, 16, 78-79. pasquali t. (1985) colbricon lago superiore (trentino orientale). preistoria alpina, 21, 202. 148 conforti j. et al. solano s. (2017) ll rogo votivo di vione-tor dei pagà nel contesto delle manifestazioni di culto protostoriche in valcamonica e nell’arco alpino centroorientale. in: “tor dei pagà: protostoria e medioevo di un sito d'alta quota. indagini archeologiche 2011-2017”, bellandi g., sannazaro m. ed., 323338 starnini e. (2017) il più antico popolamento umano: paleolitico e mesolitico. in harari m. ed. il territorio di varese in eta preistorica e protostorica. varese, 79-85. vallè f., visentin d., fontana f., furlanetto g., peresani m., pini r., quirino t., ravazzi c. (2022) gli incendi nel mesolitico alle alte quote alpine. il ruolo della vegetazione, del clima e del popolamento. in ravazzi c., artioli g., badino f., et al. eds. scenari di ricostruzione delle interazioni uomo-ambienteclima in lombardia (n-italia) dal paleolitico medio all’età del ferro. rivista di scienze preistoriche lxxii s2 2022, preistoria e protostoria in lombardia e canton ticino, 14-16. ms. received: november 13, 2025 revised: december 14, 2025 accepted: december 15, 2025 available online: december 19, 2025 p.g., bronk ramsey c., butzin m., cheng h., edwards r.l., friedrichet m., grootes p.m., guilderson t.p., hajdas i., heaton t.j., hogg a.g., hugen k.a., kromer b., manning s.w., muscheler r., palmer j.g., pearson c., van der plicht j., reimer r.w., richards d.a., scott e.m., southon j.r., turney c.s.m., wacker l., adolphi f., büntgen u., capano m., fahrni s.m., fogtmann-schulz a., friedrich r., köhler p., kudsk s., miyake f., olsen j., reinig f., sakamoto m., sookdeo a., talamo s. (2020) the intcal20 northern hemisphere radiocarbon age calibration curve (0-55 cal kbp). radiocarbon, 62, 725-757. doi: 10.1017/rdc.2020.41 sannazaro m. (2016) archeologia d’alta quota: le fortificazioni basso-medievali di tor dei pagà (vione, bs). in: archeologia classica e post-classica tra italia e mediterraneo. scritti in ricordo di maria pia rossignani, lusuardi siena s., perassi c., sacchi f., sannazaro m. eds, milano, 243-253. scaife r., biagi p. (1994) pollen analysis of the rondeneto mesolithic site and dating of peat accumulation in the valcamonica region (northern italy). in biagi p., nandris j. eds. highland zone exploitation in southern europe. monografie di natura bresciana, 20, 143-152. scoz l., cavulli f., fedrigotti a., neri s., pedrotti a., dalmeri g. (2015) new data on the first human settlements in western trentino: the site of pozza lavino in the ledro valley (trentino, italy), quaternary international. doi: 10.1016/j.quaint.2015.11.112 149 mesolithic settlement in upper valcamonica 150 sess 0_retro e indice edi.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 statistical analysis of pleistocene calcareous microplanktonic assemblages: an attempt for understanding the variations of environmental parameters claudia lupi 1, miriam cobianchi 1, luciani valeria 2 & manuela bordiga1 1 dipartimento di scienze della terra, università di pavia, pavia 2 dipartimento di scienze della terra, università di ferrara, ferrara corresponding author: c. lupi. <clupi@dst.unipv.it> abstract: lupi c. et al., statistical analysis of pleistocene calcareous microplanktonic assemblages: an attempt for understanding the variations of environmental parameters (it issn 0394-3356, 2011) the application of a multivariate statistical approach to a database concerning the occurrence of the two major calcareous planktonic groups (calcareous nannofossils and foraminifera) provides a potential additional instrument to identify the variation over time of the sea surface water parameters riassunto: lupi c. et al., analisi statistica di associazioni microplanctoniche del pleistocene: un tentativo per la comprensione delle variazioni dei parametri ambientali (it issn 0394-3356, 2011) l’applicazione di metodi statistici quali l’analisi multivariata su di un database concernente la distribuzione dei due principali gruppi di microplancton calcareo (nannofossili calcarei e foraminiferi) fornisce un ulteriore strumento per identificare le variazioni nel tempo dei principali parametri delle acque superficiali. key words: calcareous nannofossils, planktonic foraminifera, principal component analysis parole chiave: nannofossili calcarei, foraminiferi planctonici, principal component analysis 1. introduction in the view of the paleoenvironmental reconstructions based on the ecological meaning of fossil species, statistical methods are here used to investigate the ecological preferences of pleistocene calcareous micro-planktonic species and assemblages (nannofossils and foraminifera) of the core md 97-2114 (sw pacific ocean) in order to highlight the variability through time of the main sea surface water parameters. several recent studies, in fact, have demonstrated the effectiveness of multivariate statistical approaches to the pleistocene fossil record in detecting paleoenvironmental changes or paleoecology preferences of extinct species (e.g., malmgren & kennett, 1976; boeckel & baumann, 2004; maiorano et al., 2009). this approach highlights characteristic assemblages in order to determine, from a numerical point of view, the relations among the species involved in the assemblages. however, the knowledge of the ecology for some species presents certain ambiguities, making at times still problematical the interpretation of the past environments. starting from our micropaleontological database we provide statistical and graphical treatments from coccolithophorids and planktonic foraminifera firstly processing the data separately secondly making a composite database. we process together the nannofossils and the planktonic foraminifera because these groups characterize the surface water ecosystem. the application of the statistical methods simultaneously to the two major calcareous plankton groups is an innovative step for obtaining combined and crossed information. this approach may represent a potential additional instrument for identifying the puzzling sea surface water parameters whose variations have, over time, limited the planktonic foraminiferal and coccolithophorid distribution and abundance fluctuations. 2. material and methods our case history is the core md 97-2114 (42° 22.32’s; 171°20.42’w) which was recovered from an images cruise (international marine past global change study) at a water depth of 1,935 m on the north-eastern slope of the chatham rise (southwestern pacific ocean). the succession is 28 m thick and exhibits pelagic and hemipelagic sediments. the bio-magnetostratigraphic calibration of the core is accurately constrained (lupi et al., 2008; venuti et al., 2007). a detailed benthic oxygen isotope stratigraphy was recently performed by cobianchi et al. (in prep.). the age model indicates that the studied succession shows a continuous sedimentary record for the past 1.07 ma and spans from the marine isotope stage (mis) 1 to the mis 29 with an average sediment accumulation rate of ca 2.6 cm/kyr. the micropaleontological content was analysed in 113 samples and the data have been collected using standard methodologies (lupi et al., 2008) and then processed utilizing the basic and useful statistical methods of mono and multivariate analysis of the past software (paleontology statistic, hammer et al., 2001) to perform a principal com 212 214 213 ponent analysis (pca). the pca is a procedure for finding hypothetical components which account for as much of the variance in a multidimensional database (davis, 1986; harper, 1999). these new variables are liear combinations of the original variables, in our case the nannofossils and planktonic foraminifera genera and species. the pca may be used for simple reduction of the data set to only two/three variables (the two/three most important components), that are correlated with some other underlying variables. for ecological data, the components might be physical parameters (for example water temperature or nutrient availability). moreover, it is possible to verify what degree (loading) the different original variables (in our case, the taxa) enter into the new variable (the components). these loadings are important when we interpret the meaning of the components. in fact, the loading diagrams reveal the affinities of the taxa with respect to the unknown components that influence the planktonic foraminiferal and nannofossil distribution in the core. potentially, using the taxa with known ecology, we can interpret the components as environmental parameters. 3. results the good to excellent microfossil preservation throughout the core allowed us to identify 48 species among the nannofossils and 30 species among the planktonic foraminifera. the nannofossil assemblages are dominated by the small gephyrocapsa kamptner, and subordinately by calcidiscus leptoporus (murray & blackman) (abundance up to 25% of assemblages), coccolithus pelagicus (wallich) (up to 40%), pseudoemiliania lacunosa (kamptner), (up to 40%), medium gephyrocapsa kamptner (up to 40%), reticulofenestra minuta roth (up to 30%), emiliania huxleyi (lohmann) (up to 20%), helicosphaera carteri (wallich) (up to 20%). since small gephyrocapsa represents on average almost the 50% of the nannofossil assemblage, this morphogroup tends to obscure the fluctuations within the less common species. hence, for ecological interpretation and multivariate analysis, the small gephyrocapsa was removed from the quantitative analysis. the pca highlights the two major components driving the composition of assemblages: the first one explains the 51% and the second the 23% of variance. component 1 is positively loaded by c. pelagicus (0.85), and negatively by p. lacunosa (0.44). component 2 is positively loaded by p. lacunosa (0.69), c. pelagicus (0.44) and by r. minuta (0.45). the most common planktonic foraminiferal species is globoconella inflata d’orbigny (34%) followed in abundance by globigerina bulloides d’orbigny, (19%), neogloboquadrina incompta (cifelli) (11%) and neogloboquadrina dutertrei d’orbigny (8%). the pca highlights that the two major components explain, respectively, the 32% and the 27% of variance. component 1 is positively loaded by g. inflata (0.45) and negatively loaded by g. bulloides (-0.40). component 2 is positively loaded by truncorotalia truncatulinoides (d’orbigny) (0.50) and g. inflata (0.45), and negatively by truncorotalia crassaformis (galloway & wissler) (-0.55) for the composite database, through the pca we identify three major components. they account for the 33.5%, 17% and 12% of the variance, respectively. component 1 is positively loaded by pseudoemiliana lacunosa (0.49) and negatively loaded by coccolithus pelagicus (-0.66). component 2 is positively loaded by c. pelagicus (0.47), and p. lacunosa (0.41) and negatively by globoconella inflata (-0.55), finally, none species loads positively component 3, whereas it is negatively loaded by c. pelagicus (-0.46) and g. inflata (-0,69). 4. discussion and conclusions using the ecological meaning of the taxa, their affinities and relations with the unknown principal components (pcs), we can interpret these latter as environmental parameters. however, the ecological meaning of the some species is still matter of debate (for example pseudoemiliania lacunosa) due to scarce data available or because they are extinct. checking the effectiveness of the statistical approach, we observe that the processing of each microfossil group separately reveals two major pcs driving the associations. the pcs found for nannofossils and planktonic foraminifera can be different but they have to be consistent because reflecting the same surface water characters. for each processing we identify a great number of species that makes the discussion very complex and full of ambiguities. through the use of a composite database we reduce the pcs from four to three and the number of species involved decreases as well. however, these species were already present in the first elaboration confirming that the composite approach could be valid. among the three parameters, one (pc1) mainly influences only the nannofossils. in the interpretations of the data we have to take in account this constrain searching for a parameter that could influence primarily the nannofossils (phytoplankton) with respect to the foraminifera (zooplankton), as can be for example the light. the final interpretation will be based on the ecological meaning of species with well-known preferences thus helping to clarify the environmental behavior of different statistical analysis of pleistocene calcareous ... 214 ms. received: testo ricevuto il fossil groups. as an example, in our case history the oligotrophic foraminiferal species g. inflata, negatively loaded with respect to pc2, appears to validate the hypothesis about the meaning of a supposed eutrophic nannofossil species (c. pelagicus), positively loaded with respect to the same component. in conclusion, we proposed here, for the first time, the application of statistical methods simultaneously to two microfossil groups. the data have to come from the same samples and to be measured in the same units (percentage). this approach shows apparently some vantages. since it is just an attempt, the idea will be checked in more casehistories adding at the database (matrix) more independent data from isotopic or sedimentologic analyses to verify and corroborate the final interpretations. references boeckel b. & baumann k.-h. (2004) distribution of coccoliths in surface-sediments of the south-eastern south atlantic ocean: ecology, preservation and carbonate contribution. marine micropaleontology, 51, 301–320. davis j.c. (1986) statistics and data analysis in geology. john wiley and sons. hammer ø., harper d.a.t. & ryan p.d. (2001) past: paleontological statistics software package for education and data analysis. palaeontologia electronica, 4 (1) http:// palaeo-electronica. org/2001_1/past/issue1_01.htm harper d.a.t. (1999). numerical palaeobiology. john wiley and sons lupi c., luciani v. & cobianchi m. (2008) integrated calcareous nannofossil and planktonic foraminiferal bioevents of the last 1.07 ma: a case study from the east new zealand pacific ocean. micropaleontology, 54 (5), 463-476. maiorano p., marino m. & flores j.a. (2009) the warm interglacial marine isotope stage 31: evidences from the calcareous nannofossil assemblages at the site 1090 (southern ocean). marine micropaleontology, 71, 166-175. malmgren b. & kennett j.p. (1976) principal component analysis of quaternary planktic foraminifera in the gulf of mexico: paleoclimatic applications. marine micropaleontology, 1, 299-360. venuti a., florindo f., michell e. & hall i. r.(2007) magnetic proxy for the deep (pacific) western boundary current variability across the mid-pleistocene climate transition. earth and planetary science letters, 259, 107-118. january 13, 2011 13 gennaio 2011 c. lupi et al. sess 3_14022011_edi as (3).pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 inferring the diet of extinct elephants: the case study of straight-tusked elephants from neumark nord 1 (northeastern germany) maria rita palombo1 & paola iacumin2 1dipartimento di scienze della terra, università “sapienza”, roma 2dipartimento di scienze della terra, università degli studi di parma. corresponding author: maria rita palombo <mariarita.palombo@uniroma1.it> abstract: palombo m.r. & iacumin p., inferring the diet of extinct elephants: the case study of straight-tusked elephants from neumark nord 1 (northeastern germany). (it issn 0394-3356, 2011) inferring the diet of fossil mammals is a major approach to mammalian palaeobiology and palaeoecology. compared to other mammals, proboscideans pose significant problems because elephants eat different kinds of food and may change it frequently. results obtained by analysing the last molars of palaeoloxodon antiquus from neumark nord, highlight the effectiveness of a multidisciplinary approach in inferring the dietary adaptation of elephants. the microwear pattern and stable isotope data obtained for the straight-tusked elephants from neumark nord 1, suggest they were mainly grazers in a wooded grassland and moderately humid environment. riassunto: palombo m.r. & iacumin p., dedurre la dieta degli elefanti fossili: l’esempio di palaeoloxodon antiquus di neumark nord 1 (germania nordorientale). (it issn 0394-3356, 2011) la definizione della dieta delle specie fossili è uno degli aspetti di maggiore interesse in paleobiologia e paleoecologia. uno studio che associ l’analisi delle microtracce di usura dentale e degli isotopi stabili è particolarmente utile nel caso degli elefanti fossili, in quanto la definizione delle loro abitudini alimentari pone problemi interpretativi dovuti alla varietà di cibo assunta. lo studio, applicato agli esemplari di palaeoloxodon antiquus di neumark nord 1, dimostra come questi esemplari vivessero in condizioni climatiche miti e relativamente umide e si cibassero prevalentemente di erbe. key words: microwears, stable isotope, diet, palaeoloxodon antiquus, neumark nor 1, pleistocene, germany. parole chiave: microtracce di usura, isotopi stabili, dieta, palaeoloxodon antiquus, neumark nord 1, pleistocene, germania. 1. introduction inferring the diet of fossil mammals is a major approach to mammalian palaeobiology and palaeoecology. therefore palaeodiet recon-struction is of increasing interest in depicting environmental changes as well as in investigating a wider range of ecological issues. since the second half of the last century, two methodological approaches have been developed to supply this information. they are based on microwear enamel defects (produced on tooth enamel by the attrition of food particles), and on stable isotope analyses. compared to other mammals, elephants pose significant logistical problems for dental microwear analysis (palombo et al., 2005, todd et al., 2007). elephants exhibit a quite unusual manner of food comminution, depending on the extent of the masticator surface and on the high number of enamel bands of their teeth. moreover, elephants eat different kinds of food and may change it frequently. as a result, to establish the average dietary adaptation of an elephant population, it should be convenient to combine microwear with stable isotope analyses. this study is aimed at comparing the results obtained by analysing dental microwears and stable isotopes in straight-tusked elephants from neumark nord 1 (sachsen-anhalt; germany) (palombo et al., 2010), a site which provide an extraordinary palaeontological record, counting about two hundreds of flora species, mollusks, insects, and a diversified vertebrate fauna, including fishes, amphibians, reptiles and several more or less complete skeletons of large mammals found in sediments deposited during an interglacial phase (? mis 7, ? mis 5e) (meller, 2010). 2. microwears analysis, performed on twenty among the best preserved ultimate e penultimate molars (m2, m3) using both stereomicroscope and scanning electron microscope, reveal a modest variability in the microwear patterns of elephants from neumark nord 1. scratches, especially coarse and hypercoarse, prevail, though pits, both large and small, maybe locally abundant. coarse scratches, large and relatively deep, with a u-shaped bottom are usually more frequent in the middle part of enamel band, while fine, sometimes, narrow, deep, and vshaped scratches have been observed on the border of enamel band. cross-coarse scratches are always present. some large and deep cavities (gouges) are also observed. the presence of very small fragments of enamel prisms at the bottom of the cavities suggest the eating of hard food such as wood or bark. the comparison of the range of variability of num 155 157 155 ber of pits and scratches in extant herbivores highlights the peculiarity of microwear patterns in elephants. the morphospace boundaries were obtained by plotting the average numbers of scratches of each dietary category versus the average numbers of pits (fig. 1). neumark nord 1 elephants plot within the so-called meal-by-meal mixed feeders that could change their dietary behaviour depending on either the most abundant or the most pleasing food, but close to the morphospace of grazers. in the principal component analysis, extant elephants plot close to the fruit dominated browsers, while the fossil elephants from neumark nord 1, fall in the overlapping area of fruit-dominated browsers and grazers. this is because the variables that mostly contributed to the setting are the percentage of coarse scratches, large pits and gouges (first component) as well the percentage of cross scratches (second component), not the average number of pits and scratches that, in the bivariate analysis, permits to separate grazers from browsers. all in all, the microwear pattern of elephants from neumark nord 1 suggests they were meal-by-meal mixed feeders, including a large amount of grasses in their diet..   3. stable isotopes stable isotopes have proved useful in determining the dietary habits of mammals and to obtain information on past climates and environments (see e.g. deniro, 1987; longinelli, 1994; iacumin et al., 1996; bocherens, 2003). the δ18o values calculated from the neumark nord 1 sample, are not statistically different from those already obtained for the italian elephants from la polledrara di cefig. 1, bivariate plot of the average number of pits versus average number of scratches in extant ungulates (data from solounias & semprebon 2002), extant elephants (loxodonta africana and elephas maximus), and palaeoloxodon antiquus from neumark nord 1 (nn). diagramma di dispersione del numero medio di cavità e strie negli ungulati viventi (dati da solounias & semprebon 2002), negli elefanti viventi l. africana ed e. maximus, e in p. antiquus di neumark nord 1 (nn). fig. 2, principal component analysis: scatterplot diagram of extant ungulates extant elephants (loxodonta africana and elephas maximus) and palaeloxodon antiquus from neumark nord 1 (nn). variables are average number of pits and scratches, % of large pits, % of gouges, % of fine scratches, % of coarse/hypercoarse scratches, % of mixed scratches, % of cross scratches. analisi delle component principali effettuata per gli ungulati e gli elefanti (l. africana e e. maximus) attuali e p. antiquus di neumark nord 1. variabili: numero medio di cavità e strie, % di cavità grandi; %di fosse; % di strie sottile; % di strie larghe; di strie “miste”; % di incroci. fig. 3, carbon and oxygen isotope values of diet and local meteoric water calculate from the measured carbon and oxygen isotope value of apatite of elephant samples preserved in neumark nord 1, and fields of variation of the same parameters of the italian sites "la polledrara" and casal de pazzi". the symbol represents the mean δ18o value of modern precipitation in the neumark nord area (halle, leipzig). dieta e valori delle acque meteoriche calcolate in base ai valori degli isotopi dell’ossigeno e del carbonio ottenuti dall’analisi dell’apatite del campione di neumark nord 1. sono riportati i campi di variabilità ottenuti per i siti italiani di “la polledrara” e “casal de’ pazzi): il simbolo indica il valore del δ18o delle precipitazioni moderne nell’area di neumark nord (halle, lipsia). m.r. palombo & p. iacumin 156 ms. received: testo ricevuto il canibbio and casal de’ pazzi (palombo et al., 2005). this may suggest that the climate were similar at the two different latitudes during the middle pleistocene. however, we have also to consider that, unlike the italian elephants, the german ones are enriched in 18o of about 2‰ in comparison to the modern precipitation in the leipzig area. this probably suggests that the mean environmental condition were not far from modern ones, slightly warmer at the most. the nitrogen isotope composition of dentine and bone collagen (δ15ncoll) are consistent with a diet based mainly on grass which has significantly higher δ15n compared to woody growth forms (virginia & delawiche, 1982). accordingly, isotope results suggest that elephants from neumark nord were mainly grazers in a wooded grassland and moderately humid environment. 4. remarks results obtained by analyzing the sample of molars of palaeoloxodon antiquus from neumak nord 1, highlights the effectiveness of a multidisciplinary approach to a large data set in inferring the dietary adaptation of elephants. elephants, indeed, are known as mega-herbivores showing the highest range of variability in feeding among the extant species. both loxodonta and elephas feed on more than 80 different plant species, eating low grass as well as tree branches or fruits (the latter are eaten especially by the forest species loxodonta cyclotis), as well as aquatic vegetation. as a result, the ingested food would vary meal-by-meal, and microwear patterns can change considerably, depending on geographic area, season and also during short time spans. accordingly, isotope analysis could be a fundamental support in inferring the average dietary behaviour of fossil proboscideans as well as the physic parameters of the environment they inhabited. among extant elephants grazing is generally related to the increase of grass availability during humid periods, whereas browsing increases when grass tend to be withered. accordingly, the patterns in microwear shown by the elephants from neumark nord are consistent with the stable isotope data obtained for the site, suggesting temperate and moderately humid environmental conditions. acknowledgements we thank prof. h. meller for inviting us to study elephants from neumark nord. references bocherens h. (2003) isotopic biogeochemistry and the paleoecology of mammoth steppe fauna. advances in mammoth research. deinsea, 9, 57-76. deniro m.j. (1987) -, stable isotopes and archaeology. american scientist, 75, 182-191. iacumin p., bocherens h., mariotti a. & longinelli a. (1996) oxygen isotope analyses of co-existing carbonate and phosphate in biogenic apatite: a way to monitor diagenetic alteration of bone phosphate? earth and planetary science letters, 142, 1-6. longinelli a. (1984) oxygen isotopes in mammal bone phosphate: a new tool for paleohydrological and paleoclimatological research? geochimica et cosmochimica acta, 48, 385-390. meller h. (ed.) (2010) elefantenreich eine fossilwelt in europa. landesmuseum für vorgeschichte, halle (saale), palombo m.r., filippi m.l., iacumin p., longinelli a., barbieri m. & maras a. (2005) coupling tooth microwear and stable isotope analyses for palaeodiet reconstruction: the case study of late middle pleistocene elephas (palaeoloxodon) antiquus teeth from central italy (rome area). quaternary international, 126–128, 153–170 palombo m.r., albayrak e. & marano f. (2010) the straight-tusked elephants from neumark nord, a glance to a lost world. in: meller h. (ed.) – elefantenreich eine fossilwelt in europa. landesmuseum für vorgeschichte, halle (saale), 219-247. solounias n. & semprebon g. (2002) advances in the reconstruction of ungulate ecomorphology with application to early fossils equids. american museum novitates, 3366, 1–49. todd n.e., falco n., silva n. & sanchez c. (2007) dental microwear variation in complete molars of loxodonta africana and elephas maximus. quaternary international, 169–170, 192–202. virginia r.a. & delawiche c.c. (1982) natural 14n abundance of presumed n2-fixing and non-n2 fixing plants from selected ecosystems. oecologia, 54, 317325. inferring the diet of extinct elephants: the case study of ... january 15, 2011 15 gennaio 2011 << /ascii85encodepages false /allowtransparency false /autopositionepsfiles true /autorotatepages /none /binding /left /calgrayprofile (dot gain 20%) /calrgbprofile (srgb iec61966-2.1) /calcmykprofile (u.s. web coated \050swop\051 v2) /srgbprofile (srgb iec61966-2.1) /cannotembedfontpolicy /error /compatibilitylevel 1.4 /compressobjects /tags /compresspages true /convertimagestoindexed true /passthroughjpegimages true /createjobticket false /defaultrenderingintent /default /detectblends true /detectcurves 0.0000 /colorconversionstrategy /cmyk /dothumbnails false /embedallfonts true /embedopentype false /parseiccprofilesincomments true /embedjoboptions true /dscreportinglevel 0 /emitdscwarnings false /endpage -1 /imagememory 1048576 /lockdistillerparams false 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/pdfxoutputintentprofileselector /documentcmyk /preserveediting true /untaggedcmykhandling /leaveuntagged /untaggedrgbhandling /usedocumentprofile /usedocumentbleed false >> ] >> setdistillerparams << /hwresolution [2400 2400] /pagesize [612.000 792.000] >> setpagedevice imp. nisio ii ffeennoommeennii ddii sspprrooffoonnddaammeennttoo:: ssttaattoo ddeellllee ccoonnoosscceennzzee eedd aallccuunnii eesseemmppii iinn iittaalliiaa cceennttrraallee sstteeffaanniiaa nniissiioo dipartimento dei servizi tecnici nazionali servizio geologico nazionale v. curtatone, 3 00185 roma riassunto nella letteratura nazionale ed internazionale sono stati da tempo codificati numerosi termini per indicare i vari tipi di cavità che si aprono nel terreno, attualmente però viene sempre più spesso utilizzato il termine sinkhole per definire queste forme, spesso omologhe, ma sviluppatesi attraverso processi genetici differenti. così tale termine risulta piuttosto semplificativo e generico. questo lavoro si propone perciò di riesaminare la terminologia con la quale sono state indicate le varie forme in relazione alla loro genesi e di proporre una definizione più precisa del termine sinkhole. nella letteratura italiana per indicare i vari tipi di cavità subcircolari furono introdotti sin dai tempi più antichi i termini di dolina (geneticamente distinta in diversi tipi), sprofondamento e camino di collasso. nel primo caso il processo morfogenetico si sviluppa in rocce solubili per dissoluzione attraverso l’infiltrazione d’acqua di ruscellamento. nel secondo caso i fattori predisponenti sono la gravità e l’antropizzazione, nel terzo invece i fattori principali dell’evoluzione di tali forme, oltre alla dissoluzione sono costituiti dalla risalita di fluidi aggressivi e dai fenomeni di aumento e di diminuzione di pressione indotti dalle oscillazioni della tavola d’acqua al di sotto del piano campagna. anche nella letteratura anglosassone per le cavità carsiche era utilizzato il termine doline (suddiviso poi in vari tipi) equivalente alla dolina della letteratura italiana; in seguito esso è stato quasi del tutto sostituito dal termine sinkhole. quest’ultimo è stato utilizzato la prima volta per indicare depressioni subcircolari dovute al crollo di piccole cavità carsiche, sinonimo quindi di dolina, successivamente è stato adottato per indicare gli sprofondamenti di qualsiasi genere. prendendo in considerazione i meccanismi genetici che favoriscono lo sviluppo degli sprofondamenti s.l. il termine sinkhole in senso stretto dovrebbe essere adottato soltanto per quelle forme in cui il processo genetico principale è la risalita dei fluidi dal basso, attraverso reticoli di fratture che mettono in comunicazione un substrato carsificato con i sedimenti superficiali, con conseguenti fenomeni di piping o suffosione. esso sarebbe pertanto sinonimo dei termini camino di collasso o voragine di terra della letteratura italiana e di piping sinkhole della letteratura anglosassone. i casi di sinkhole in italia risultano concentrati nelle piane alluvionali, nelle immediate vicinanze di dorsali carbonatiche, in contesti geologico-strutturali ed idrogeologici complessi innescati da cause di diversa natura (sismi, siccità, alluvioni, emungimenti di acque etc.). la presenza di un pacco di sedimenti impermeabili o semi-permeabili, al tetto di un substrato carbonatico carsificato, un reticolo di faglie e diaclasi che mettano in comunicazione i due mezzi, sono fattori predisponenti essenziali. inoltre la presenza di fluidi liquidi e gassosi nel sottosuolo, co2 e h2s, che consentano la dissoluzione e di conseguenza il sifonamento dei materiali di copertura è stata riscontrata nella maggioranza dei casi. abstract technical literature offers a lot of terms to indicate different types of geological cavities, but recently the term sinkhole seems to be commonly adopted to indicate underground cavities which are similar in their features but have different morphogenetic origins. that is why the term sinkhole appears to be rather generic or inadequate. the aim of this work, therefore, is to propose a new terminology for every kind of cavity and to associate a more rigorous definition to each of them, according to their different morphological genesis. in the italian traditional literature the terms “dolina” (divided in various types), “sprofondamento” and “camino di collasso” were adopted to indicate different kinds of sub-circular collapses. according to the first term the soil dissolution is caused by the infiltration of water in soluble rocks; according to the second one gravity and anthropizzation are the main factors causing these collapses and according to the last one, above the soil dissolution, the predisposing factor is the pressure of the water coming back to the plane surface level. in the english literature the term doline (still divided in several types) was originally adopted to indicate karst caves as an equivalent of the italian word “dolina” but it was later replaced by the term sinkhole. at first this term simply indicated sub-circular depressions due to the landslide of small karst caves, but actually it is adopted to indicate every kind of cavity. taking into account the processes that cause the development of a sinkhole, the use of this term seems only suitable to indicate cavities caused by a piping process (“suffosione” in italian) and therefore it should be a synonymous of the italian term “camino di collasso” (known as piping sinkhole in the english literature). the sinkholes in italy are concentrated in alluvial flats, near carbonatic ridges, in some structural and hydrogeological contexts which were originated by different causes (earthquakes, dryness, alluviums, water wells etc.). impermeable sediments laid on the top of karst carbonatic bedrocks, faults and fractures between the two layers, are the main predisposing factors. moreover, the presence of water and gases, such as co2 and h2s, concurring to the dissolution and the piping processes, has been detected in almost all the circumstances. parole chiave: sinkhole, sprofondamenti, suffosione. keywords: sinkhole, sinking, piping il quaternario italian journal of quaternary sciences 1166(1), 2003, 121-132 122 s. nisio iinnttrroodduuzziioonnee i fenomeni di sprofondamento sono riconosciuti in diverse parti del mondo. negli stati uniti (california, florida) tali fenomeni sono particolarmente diffusi e costituiscono una delle maggiori calamità naturali scarsamente prevedibili e dalle quali non è facile difendersi (sinclair & steward, 1985; newton, 1987; wilson & shock, 1996). in florida il fenomeno è talmente frequente che il servizio geologico nazionale ha predisposto siti internet, destinati alla popolazione, per denunciare in tempi reali il verificarsi di sprofondamenti tipo sinkhole. le cause naturali sono generalmente preponderanti mentre le cause antropiche sono concause o accessorie anche se nell’ultimo ventennio si è registrato un aumento dei casi in tutto il mondo in seguito probabilmente proprio all’espansione urbanistica (sinclair, 1982; newton, 1987; tihansky & galloway, 2000). ii ffeennoommeennii ddii sspprrooffoonnddaammeennttoo recentemente per indicare gli sprofondamenti di qualsiasi genere viene utilizzato, da esperti del settore e non, il termine sinkhole, che ha quasi del tutto sostituito altri termini più specifici, generando una notevole confusione terminologica. un uso più corretto del termine sinkhole permetterà di individuare meglio il tipo di sprofondamento cui ci si vuole riferire. il termine sinkhole (che tradotto letteralmente significa “pozzo di scarico”, “buco di scolo”) è stato introdotto per la prima volta da fairbridge (1968) e successivamente da monroe (1970) per indicare una depressione di forma sub-circolare dovuta al crollo di piccole cavità carsiche sotterranee. infatti alcuni autori, monroe (1970), jennings (1985), white (1988), ed altri distinguono fenomeni di solution sinkhole, collapse sinkhole e subsidence sinkhole (coincidenti con i termini di solution doline, collapse doline, subsidence doline introdotti da cramer, 1941 e successivamente uti l izzati da castiglioni nel 1986 in italia e da molti altri autori), pertanto il termine sinkhole sarebbe sinonimo di dolina. attualmente negli stati uniti e in gran bretagna il temine sinkhole viene usato frequentemente e definisce una qualunque cavità nel terreno di forma sub-circolare originatasi per motivi diversi. beck, (1984), beck & wilson, (1987), berti et al., (2002 a) utilizzano tale termine per indicare anche cavità, di forma non necessariamente sub-circolare, apertesi nel terreno per cause antropiche. anche in italia di recente (a partire dagli anni novanta) è stato adottato il termine sinkhole (faccenna et al., 1993, brunamonte et al., 1994; nolasco, 1998; ciotoli et al., 1998 e molti altri) per indicare una cavità sub-circolare, che si apre improvvisamente nel terreno, con richiamo di materiali verso il basso. esso pertanto sarebbe sinonimo di sprofondamento s.l. ed è applicabile a fenomeni come le doline di crollo, gli sprofondamenti di natura antropica, i camini di collasso o voragini di terra, che si aprono nei terreni a granulometria variabile. la dolina di crollo ( cramer, 1941, castiglioni, 1986) indica una depressione tipica di aree carsiche, che si forma principalmente per dissoluzione dovuta all’assorbimento nel terreno di acqua da ruscellamento (anelli, 1959; 1965, sweeting, 1972; ford & williams, 1989; klimchouck et al., 1997; ferrarese & sauro 2001; macalluso et al., 2002), cui si aggiunge il crollo per gravità della parte superiore della cavità. uno sprofondamento in genere è una depressione di forma varia, anche se generalmente sub-circolare, formatasi rapidamente, tipica oltre che di zone carsiche, di aree di pianura, di aree in cui nel sottosuolo sono presenti altre cavità (canuti, 1982). lo sprofondamento catastrofico, poiché improvviso ed arrecante danni, comprende anche quei dissesti non direttamente collegabili a fenomeni carsici, come le cavità sotterranee originate dall’attività antropica, in aree urbanizzate, da miniere, scavi, cunicoli e cavità di antiche catacombe.gli sprofondamenti sono legati principalmente alla gravità. i “camini di collasso” o “voragini di terra” sono ampie e profonde depressioni sub-circolari con dimensioni da pochi metri al centinaio di metri e profondità di alcune decine di metri, a pareti sub-verticali che si aprono rapidamente in terreni a granulometria variabile. i camini di collasso sono in genere colmati da acque, spesso mineralizzate, formando laghetti e specchi d’acqua; sono caratterizzati da subsidenza che può localmente essere dovuta a presenza di sorgenti. sono localizzati in genere su allineamenti tettonici lungo i quali spesso si evidenziano anomalie di fluidi liquidi e gassosi; la continua erosione delle pareti del camino provoca il progressivo colmamento della voragine, un aumento del diametro e nello stesso tempo una diminuzione della profondità dello specchio d’acqua. la formazione dei camini di collasso è improvvisa ma può essere realizzata in un evento unico o in più eventi con progressivo cedimento delle pareti (brunamonte et al., 1994). nel primo caso il substrato è interessato da un condotto unico e la cavità presenta nel tempo dimensioni più o meno stazionarie. nel secondo caso lo sviluppo del camini di collasso avviene per lento dilavamento dal basso verso il tetto della cavità; la cavità stessa tende ad allargarsi notevolmente per cedimento progressivo e coinvolgimento di volumi sempre più grandi. si è constatato che la maggior parte di tali fenomeni è dovuta ad una serie di cause, di cui si parlerà in seguito, ma ruolo importante assumono i processi di risalita, sifonamento e suffosione, (sensu castiglioni, 1986) (derbyshire & mellors, 1988; derbyshire et al., 1991; billiard et al., 1992; 1993; muxart et al., 1994). un processo di suffosione, definito da castiglioni (1986), è un effetto meccanico dello scorrimento subsuperficiale dell’acqua nel terreno (con dimensioni granulometriche dalle argille alle ghiaie) che si realizza quando quest’ultimo è crepacciato o poroso e quando l’acqua abbondante e con pressione elevata, riesce a trovare vie di scorrimento in cui passare con velocità abbastanza sostenuta. il passaggio dell’acqua provoca l’erosione di materiale e la formazione di canalicoli a sviluppo sub-orizzontale e di condotti tubolari lungo le linee idrauliche di flusso. quest’ultimo fenomeno viene indicato nella letteratura anglosassone con il termine piping. pertanto nel processo di formazione dei camini di collasso dovrebbe avere un ruolo importante la pressione idraulica iniziale nei condotti (guerricchio, 1982). sprofondamenti in cui è stata accertata la presenza di meccanismi di questo tipo tipo sono noti in letteratura anglosassone come piping sinkhole. secondo forti (2002) i fenomeni di piping si possono verificare in un sistema carsico, solo se l’acquifero termale non è confinato ed è situato a breve distanza dalla superficie. infatti secondo l’autore i meccanismi di piping non si possono sviluppare in un sistema carsico termale posto a notevole profondità e ricoperto da rocce impermeabili proprio perché la presenza di queste ultime impedirebbe ai processi di progredire, dal basso verso l’alto, in superficie. i fenomeni registrati nell’appennino ed in altre parti del mondo mostrano che i fenomeni di sinkholes, dovuti a fenomeni di risalita di fluidi dal basso, si sono formati nella maggior parte dei casi proprio in acquiferi imprigionati, con substrato posto a notevole profondità, sormontato da depositi costituiti da materiali a granulometria variabile, ma generalmente da limi, a scarso stato di consistenza, in presenza di faglie o fratture (littlefield et al., 1984; derbyshire & mellors, 1988; derbyshire et al., 1991; billiard et al., 1992; 1993; faccenna, 1993; muxart et al., 1994; ciotoli et al., 2000; berti et al., 2002 a, b; di filippo et al., 2002). pertanto sembrerebbe che proprio la presenza di faglie e diaclasi, che mettano in comunicazione i due mezzi, (permeabile di base ed impermeabile al tetto) sia la spiegazione dell’innesco di sinkhole in acquiferi imprigionati. i meccanismi di piping e suffosione sub-superficiale potrebbero essere catturati dal basso sulla direttrice a sviluppo verticale verso l’alto delle cavità carsiche, proprio per la presenza di faglie e diaclasi all’interno dei terreni di copertura posti al di sopra del bedrock carbonatico. in conclusione viene riportata la terminologia con la quale vengono indicati i diversi tipi di cavità che si aprono nel terreno. sprofondamento: è una cavità di forma varia, anche se generalmente sub-circolare, formatasi rapidamente, tipica di zone carsiche, di aree di pianura, di aree urbane, di aree il cui sottosuolo presenti altre cavità anche di origine antropica; sprofondamento catastrofico: sprofondamento rapido ed improvviso arrecante danni a persone o cose; sprofondamento di origine antropica (che potremmo definire anthropogenic sinkhole): è il collasso di una volta in cavità di origine antropica; “dolina di soluzione normale” (coincidente con il termine anglosassone di “solution sinkhole” e “solution doline”): conca chiusa originata per dissoluzione della roccia da parte dell’acqua di ruscellamento superficiale (castiglioni, 1986); “dolina alluvionale” (coincidente con il termine anglosassone di “subsidence sinkhole” o potrebbe meglio definirsi “cover sinkhole”): conca chiusa che si forma su materiali di copertura in genere, e/o alluvionali, in seguito all’originarsi, in rocce solubili sottostanti, di cavità carsiche per dissoluzione sub-superficiale o di crollo (castiglioni, 1986); “dolina di crollo” (coincidente con il termine anglosassone di “collapse sinkhole” e “collapse doline”): cavità con forma a pozzo nei calcari e in rocce solubili formatesi per il crollo del soffitto di grotte (cramer, 1941; castiglioni, 1986); “dolina di subsidenza in roccia” (coincidente con il 123i fenomeni di sprofondamento ... termine anglosassone di “rock subsidence sinkhole” o “subsidence doline”): cavità formatesi su rocce coerenti e permeabili ma non solubili, poggiate su rocce solubili per crollo di volta (castiglioni, 1986); sinkhole in senso stretto, o camino di collasso (coincidente con il termine anglosassone di piping sinkhole): cavità sub-circolare che si apre improvvisamente in terreni di varia granulometria, per meccanismi prevalenti di risalita delle acque e dei gas, di sifonamento di suffosione e di successivo collasso. in definitiva per una più corretta terminologia il termine sinkhole s.s. dovrebbe essere applicato esclusivamente a quelle cavità che si formano a seguito di processi non solamente carsici ma anche di risalita delle acque ed erosione e sifonamento dei materiali di copertura; termine equivalente così ai camini di collasso e alle voragini di terra della letteratura italiana e ai piping sinkholes della letteratura anglosassone. in alternativa sarebbe necessario aggiungere un attributo accanto al termine sinkhole per indicarne la genesi e per evitare di creare confusione circa il fenomeno cui si vuole riferire (piping, collapse, solution, subsidence, anthopic o anthropogenic, cover). per quanto riguarda gli sprofondamenti dovuti al carsismo è preferibile utilizzare il termine già esistente dolina di crollo (equivalente a collapse doline o collapse sinkhole della letteratura anglosassone), mentre per i collassi dovuti all’antropizzazione (crolli di grotte, cunicoli, miniere etc.) dove solo casualmente si formano cavità subcircolari, si può adottare il termine generico di sprofondamento antropico (o anthropogenic collapse). llee ccaauussee i sinkholes s.s. (o piping sinkhole) si formano per cause predisponenti ed innescanti. si originano in contesti di complesse situazioni geologico-strutturali ed idrogeologiche del territorio che ne costituiscono il substrato essenziale. vengono innescati per motivi di diversa natura quali un sisma, un periodo di siccità, o una alluvione (ciò che può provocare una variazione rapida del livello piezometrico), l’emungimento di grandi quantitativi di acqua dal sottosuolo. definire quale sia la causa principale è difficile poiché esse sono molteplici e generalmente concomitanti; queste possono così essere riassunte: 1) un substrato carbonatico o costituito da roccia solubile (calcari, dolomie, evaporiti o rocce solfatiche) sottoposto a fenomeni carsici; la presenza di una morfologia del bedrock accidentata, sia a piccola scala che a grande scala, con macroforme carsiche (doline, uvala, crepacci e grotte) e con cavità carsiche presenti al tetto del substrato (interfaccia suolo/roccia) risultato di processi corrosivi e pedogenetici; 2) la presenza di un pacco di sedimenti impermeabili o semi-permeabili al tetto del substrato, costituito da limi, argille, sabbie a differente granulometria, omogenee o eterogenee; 3) scarse caratteristiche fisico-meccaniche dei materiali costituenti il manto superiore (consolidazione, addensamento, resistenza); 4) presenza di un reticolo di fratture o faglie che permettano una maggiore circolazione idrica e una 124 notevole erosione meccanica; 5) presenza di abbondanti acque di circolazione sotterranea; 6) presenza di gas nel sottosuolo, generalmente co2 e h2s, che consentano la dissoluzione dei materiali di copertura e la risalita delle acque (faccenna et al., 1993; ciotoli et al., 1998); 7) intensità elevata delle precipitazioni piovose e alternanza di periodi secchi e piovosi, risultano particolarmente favorevoli alla formazione delle oscillazioni della tavola d’acqua; 8) le attività antropiche: attività estrattive, emungimenti di acqua; il forte emungimento per uso irriguo ed idropotabile fa sì che si sviluppino, in prossimità dei pozzi, coni di depressione tali da far aumentare notevolmente la velocità dei flussi idrici e quindi l’asportazione delle particelle dei sedimenti e subsidenza delle coperture alluvionali; 9) le eventuali escursioni termiche; in zone poste a quote elevate e soprattutto alle alte latitudini (nord europa), i passaggi al di sopra e al di sotto dello zero possono originare cunei e lenti di ghiaccio che tendono ad allargare le cavità nel terreno; 10)la scarsa presenza di un manto vegetale che possa esercitare un effetto limitante nei confronti della mobilizzazione dei terreni; 11)le scosse sismiche. ddoovvee ssii vveerriiffiiccaannoo i sinkholes si originano su piane alluvionali, pianure costiere, conche intermontane, generalmente di origine tettonica in corrispondenza di successioni carbonatiche massicce carsificate, sedi di falde acquifere di grande potenza, a cui si sovrappongono depositi fluvio-lacustri, lagunari, vulcanici o marini di potenza variabile (newton, 1984). se ne presentano di seguito alcuni esempi nell’appennino centrale (fig 1). fig 1 le aree interessate da fenomeni di sinkhole the areas interested from phenomena of sinkhole s. nisio 125 eesseemmppii nneell llaazziioo 11)) llaa ppiiaannaa ddii ss.. vviittttoorriinnoo, (ri) caratteri generali la piana di s. vittorino, attraversata dal f. velino, costituisce una depressione tettonica bordata da faglie che ne hanno favorito una particolare conformazione triangolare, con apice rivolto a sud (fig. 2). essa è caratterizzata da un notevole sviluppo di forme di collasso, presenti anche sui versanti circostanti; secondo la letteratura anglosassone sarebbe definita una sinkholes plain. poiché i fenomeni di sprofondamento hanno provocato e provocano tutt’ora notevoli danni alle strutture antropiche dell’area, questa è stata oggetto di studi specifici sin dai tempi più antichi (tenore 1872; verri 1886) che sono stati ulteriormente approfonditi di recente (nolasco, 1986; 1998; faccenna et al., 1993; ciotoli et al., 1998, 2000, bigi et al., 1999; centamore & nisio, 2002 a, b, 2003; bersani & castellano 2002). la piana è stata colmata da depositi fluvio-lacustri del pleistocene superiore-olocene, a differente granunometria, per la maggior parte costituiti da limi (60%), argille (20%), sabbie (10%), localmente si rivengono lenti di ghiaie, e travertini (per lo più sabbiosi), con spessori che variano aumentando verso il centro della piana fino ad un massimo di circa 130 -170 m; lungo i versanti della piana sono presenti lembi di travertini, di depositi terrazzati e di conoide, del pleistocene medio. i depositi continentali che colmano la depressione tettonica di s. vittorino ricoprono blocchi delle successioni affioranti a m.te paterno fagliati e dislocati verso il basso (centamore et al., 2003). questi blocchi sono costituiti prevalentemente da formazioni carbonatiche, sulle quali prima della fase tettonica distensiva che ha favorito la formazione della depressione, si sarebbero sviluppate forme carsiche, presenti tra l’altro sul versante di m.te paterno. sulla destra idrografica del fiume si elevano i m.ti reatini, mentre sulla sinistra sono presenti il rilievo carbonatico di m.te nuria e la dorsale di calcariola (fig. 2). la dorsale dei monti reatini, a n, è caratterizzata dalla sovrapposizione di una successione carbonatica pelagica (dell’unità dei m.ti reatini) su una successione carbonatica di piattaforma e silico-clastica dell’unità m.te nuria (centamore & nisio, a, b , 2003). il gruppo montuoso del m.te nuria, a se, è costituito da una potente successione carbonatica di piattaforma (piattaforma laziale-abruzzese) con quote che arrivano fino a 1850 m. la dorsale di calcariola è costituita prevalentemente dai depositi fluvio-lacustri del bacino di rieti che ricoprono un substrato costituito da arenarie (appartenenti all’unità del salto; centamore & nisio, 1999; 2002 a, b; 2003 centamore et al., 1999) e da termini carbonatici (dell’unità m.te navegna e dell’unità m.ti reatini). la piana è bordata da elementi tettonici distensivi e/o transtensivi che ne hanno condizionato la morfologia (da cui la caratteristica forma triangolare, centamore & nisio, 1999; 2002 a, 2003; centamore et al., in stampa; dramis & nisio, in stampa). il più importante di questi elementi è la faglia fiamignano-micciani, una dislocazione di importanza regionale a direzione nw-se ed immergente verso sw che si segue per chilometri (fig. 2), al di fuori della piana, pur essendo interrotta e spostata da faglie trasversali e oblique. la faglia mette a contatto le formazioni carbonatiche di m.te nuria con quelle prevalentemente torbiditiche della depressione del salto; attraversa tutta la valle del f. velino e continua più a nord, bordando il versante occidentale del gruppo montuoso del terminillo. il segmento che attraversa la piana di s. vittorino non è facilmente individuabile sul terreno, anche a causa dei continui e radicali interventi antropici, che dalla fine dell’ottocento hanno modificato drasticamente l’antico paesaggio lacustre; esso sembra coincidere con un allineamento micciani s. vittorino (faccenna et al., 1993; ciotoli et al., 1998; 2000; centamore & nisio, 2000). dal punto di vista idrogeologico la piana di san vittorino costituisce il luogo di recapito della circolazione idrica dei versanti limitrofi (boni et al., 1995, e da dall’aglio & campanile,1996, ciotoli et al., 1998; 2000, colombi et al., 1999; capelli et al., 2000) e, soprattutto, del sistema idrogeologico dei monti giano, nuria e velino. in questa zona le sorgenti presenti sono distribuite ai margini settentrionale e meridionale della pianura, hanno un carattere prevalentemente puntuale (con un’unica emergenza) e sono tra loro associate a costituire fronti di deflusso emergenti per trabocco della falda idrica indotto dalla coltre satura dei sedimenti alluvionali. le portate emergenti sui lati opposti della piana sono molto differenti tra loro: circa 2000 l/s per il bordo settentrionale rispetto ai circa 18000 l/s complessivi di quello meridionale (sorgenti del peschiera). alcune sorgenti puntuali sono poi presenti anche all’interno della piana con portate modeste (stimate tra 0.1 ÷ 2 l/s), poste in corrispondenza dei sinkholes. i sinkholes della piana la piana di s. vittorino, oggetto sin dalla fine del secolo scorso di una serie di interventi antropici che ne hanno modificato notevolmente il paesaggio, è caratterizzata dalla presenza di almeno 29 cavità sub-circolari (camini di collasso o sinkholes) che ospitano laghetti e piccole pozze, di sorgenti mineralizzate, in concentrazioni anomale dei fluidi gassosi, di altri numerosi piccoli sprofondamenti localizzati, ed emergenze di acqua dolce (fig 2). il primo sprofondamento di cui si ha menzione è quello che riguarda la chiesa di s. vittorino (edificata nel 1614), avvenuto nel 1703, in seguito ad una scossa sismica, che ha dato origine ad una cavità di circa 20 m di diametro e 2 m di profondità. si contano altri 5 sprofondamenti avvenuti nei secoli scorsi (tra il 1700 e il 1850; gli atlanti del 1808 ne mostrano solo due; bersani & castellano, 2002) di cui non si hanno informazioni certe. alcuni di essi sono stati riattivati nei primi decenni di questo secolo (nel 1915 e 1951; riccardi, 1951; mori, 1983;) le cavità hanno dimensioni variabili con diametri di 204, 130, 80, 50 e 15 m (tra cui il lago di paterno, il pozzo di mezzo, il pozzo burino) e profondità che variano da un massimo di 45 m a pochi metri (capelli & petitta, 1998; capelli et al., 2000). nel 1893 si aprirono improvvisamente altre 5 cavità con diametri da 100 a 8 m e profondità da 10 a 15 m e tra il 1900 e il 1903 ancora 5 con dimensioni di pochi metri. i fenomeni di sprofondamento ... 126 altre attivazioni, neoformazioni o allargamenti, si sono avute in occasioni di sismi (michetti et al., 1994), come avvenne durante il sisma del 1915, (pozzo gustavo, in seguito al terremoto di avezzano). nel 1986 in seguito ad alluvioni si aprono 3 voragini in località sciamargutta (nolasco, 1986; catenacci, 1992) con diametri da 5 a 60 m e profondità di una decina di metri. l’ultimo sinkhole, che si è formato nel 1993 presenta solo pochi metri di diametro. i sinkholes sono concentrati nella zona settentrionale della piana, tra s. vittorino e vasche, e sono allineati secondo direzioni ne-sw tra vasche e case paterno, e-w tra le terme di cotilila e s. vittorino e nw-se, nella fascia tra le sorgenti del peschieramicciani e terme di cotilia s. vittorino, in parte coincidente con il prolungamento settentrionale della faglia fiamignano-micciani, ad ovest della quale non si evidenziano più i fenomeni di sprofondamento (faccenna et al., 1993; nolasco, 1998; centamore et al., 1999; ciotoli et al., 2000, centamore & nisio, 2002, a, b, 2003; nisio, in stampa). le acque mineralizzate sono rappresentate principalmente da acque solfuree e da acque ferruginose; le emergenze sono concentrate prevalentemente ai piedi del versante di m.te paterno, tra s. vittorino e vasche, ma si rinvengono localizzate anche in sinistra del f. velino lungo l’allineamento nw-se piedimozza-cerquara. in particolare le acque ferruginose emergono in alcuni laghetti a se di s. vittorino, lungo l’allineamento corrispondente al prolungamento settentrionale della faglia fiamignano-micciani, mentre le sorgenti solfuree sono allineate con direzioni circa e-w, tra s. vittorino e vasche, e nw-se, tra pendenza e s. vittorino e tra piedimozza e cerquara, (faccenna et al., 1993; nolasco, 1998; ciotoli et al., 2000). per quanto riguarda i fluidi gassosi le anomalie di elio sono concentrate lungo un allineamento e-w tra s. vittorino e le terme di cotilia, e lungo due allineamenti nw-se, tra le sorgenti del peschiera e s. vittorino. quelle del radon si concentrano invece per la maggior parte nel settore nord-occidentale della piana e in misura minore lungo gli allineamenti micciani-s. vittorino a direzione nw-se, e con direzioni ne-sw tra vaschecase di paterno, e parallelamente al versante nordoccidentale del rilievo carbonatico di pendenza-colle impicciavera, (ciotoli et al., 2000). il lato settentrionale e quello sud-orientale della piana sono caratterizzati inoltre dall’emergenza di alcune sorgenti di acqua dolce. negli sprofondamenti presenti nell’area in esame si possono distinguere doline di crollo localmente chiamate canetre, impostate esclusivamente sui versanti di m.te paterno e sinkholes localizzati nelle coperture config 2 schema dell’ubicazione dei sinkholes nella piana di s. vitorino (rieti) scheme of the sinkholes in the s. vittorino plane (rieticentral italy) s. nisio tinentali della piana. per qualche autore (nolasco, 1998) alcune cavità di antica origine (lago di paterno, pozzo di mezzo e pozzo burino) rappresenterebbero delle doline. ma lo spessore dei depositi continentali posti al di sopra del substrato carbonatico e per la locale situazione geologico-strutturale queste depressioni si sarebbero comunque originate per fenomeni di risalita, di sifonamento ed erosione (piping) e rappresenterebbero dunque sinkholes in senso stretto (nel senso sopra indicato) (fig. 3). per altri autori (capelli et al., 2000; bersani & castellani, 2002) la genesi degli sprofondamenti nella piana di s. vittorino sarebbe legata alla dissoluzione e conseguente collasso di orizzonti di travertino, con spessori non superiori a 10 m, riscontrati in sondaggi a profondità di 7-8 m nei pressi di cotilia e a 3040 m in altre località. ma in altri sondaggi effettuati al centro della piana i travertini sono caratterizzati da spessori molto modesti e da una struttura sabbiosa, piuttosto incoerente, tale da non giustificare collassi di una certa entità. nei pressi poi del lago rotondo, verso le aree più meridionali della piana, non si sono incontrati travertini se non in spessori decimetrici. di conseguenza la sola presenza dei travertini peraltro non continui in tutta la piana, non è sufficiente a spiegare la genesi di tutte le cavità presenti nella piana stessa (fig 4). ma la disposizione degli sprofondamenti, tutti localizzati su allineamenti tettonici, la presenza sia di un acquifero confinato in profondità, sia di falde circolanti nelle coperture alluvionali, nonché la disposizione delle anomalie dei fluidi gassosi (faccenna et al., 1993; ciotoli et al., 1998, 2000, centamore & nisio, 2000) mettono in evidenza che fattore importante della genesi degli sprofondamenti in parola sono anche i processi di piping o suffosione legati ai fenomeni di dissoluzione degli orizzonti travertinosi, dove questi sono presenti (fig 4). questi fenomeni potrebbero essere stati favoriti, oltre che dai sistemi di dislocazioni, che costituiscono la via preferenziale di risalita dei fluidi, anche dalla presenza in profondità di un substrato carsificato in precedenza, le cui forme potrebbero essersi evolute in questo contesto, favorendo così le evidenze superficiali. i fenomeni di sifonamento che si produrrebbero nella parte più superficiale del manto alluvionale potrebbero avvenire in corrispondenza di più ampie cavità carsiche poste ad un centinaio di metri nel substrato carbonatico e in collegamento tramite lo sviluppato reticolo di faglie e fratture che si rinviene lungo tutta le piana. 22)) ppiiaannuurraa ppoonnttiinnaa ((llaattiinnaa)) casi di sprofondamento sono comuni in tutta la pianura pontina, costellata da numerosi laghetti e sorgenti; i laghi del vescovo, per esempio, sono una serie di cavità ubicate nell'area compresa tra il settore più meridionale dei monti lepini e il fiume uffente a sud di sezze, a ridosso di faglie di importanza regionale, che ospitano specchi d’acqua. da nord verso sud si riconoscono il lago di s. carlo, il gruppo vero e proprio denominato del vescovo e il lago mazzocchio. il gruppo del vescovo è composto da 4 specchi d'acqua, di cui 3 presentano acque mineralizzate (con presenza di alti tenori in co2, h2s e altri composti dello zolfo) e sono caratterizzati da colore opalescente, mentre uno è d'acqua dolce. quello d'acqua dolce è profondo circa 18 metri ed ha una caratteristica forma di 8. il lago 127 fig. 3 formazione di sinkholes nella piana di s. vittorino formation of sinkholes in the st. vittorino plain (rieti-central italy) i fenomeni di sprofondamento ... mazzocchio è invece alimentato dalle acque di un canale (che drena nel fiume uffente) dopo un impianto idrovoro, risulta circondato da alti canneti e difficile da reperire. doganella di ninfa, doganella di ninfa è ubicata nella porzione nordorientale della pianura pontina a pochi chilometri da latina. in questo settore la pianura pontina è bordata ad oriente dalla dorsale dei monti lepini, disposta in direzione appenninica, costituita da una potente successione di calcari di piattaforma. una faglia di importanza regionale borda il versante sud-occidentale dei monti lepini a contatto con la pianura, il substrato carbonatico viene ribassato a gradinata da un sistema di faglie (semigraben) al di sotto dei sedimenti alluvionali. in questa zona sono ospitate numerose emergenze per una portata complessiva di 15.000 l/s alimentate dall’acquifero principale ospitato nella dorsale lepina (boni et al., 1980; celico, 1983). al di sotto della pianura pontina i carbonati ribassati e chiusi al tetto dalle alluvioni prevalentemente limose costituiscono un acquifero imprigionato. a volte si riscontrano falde all’interno dei sedimenti continentali, alimentate sia da apporti meteorici sia dalla dorsale carbonatica attraverso una serie di faglie o fratture che mettono in comunicazione i due sistemi. lo sprofondamento a doganella è avvenuto il 22 agosto del 1989, in seguito ad una scossa sismica registrata nei primi giorni di agosto, e ad un periodo di siccità che ha provocato l’abbassamento della falda. la cavità passò da uno a 4 metri di diametro in soli tre giorni, per arrivare a 31 m tre anni dopo. attualmente è sede di un laghetto che assume forma ellissoidale con una superficie di 720 mq ed asse principale di 32 m. da dati recenti è stata ipotizzata la presenza a 30-40 m di profondità di travertini (bono, 1995; di filippo et al., 2002) e di alcuni deficit di massa (probabili cavità sotterranee) riscontrati da analisi gravimetriche, accompagnati ad una rete di canali e di fratture che possano provocare fenomeni di risalita, di dissoluzione e conseguentemente di erosione ed asportazione di materiale clastico con successivo collasso superficiale. tale situazione sembra molto simile a ciò che si verifica nella piana di s. vittorino. 33)) llaa vvaallllee ddeell tteevveerree ((ccaappeennaa)) nel settore nord-orientale dell’area vulcanica dei monti sabatini, in prossimità della valle del tevere, a sud del monte soratte, sono presenti forme di sprofondamento originatesi in epoca storica: lago vecchio (o lago sinibaldi), lago nuovo, fontana ciocci, lago puzzo. lago puzzo nell’area in esame dal punto di vista geologico si possono distinguere: un substrato meso-cenozoico del monte soratte e del monte belvedere, costituito dalla successione marina condensata calcareo-silico-marnosa; una successione marina, trasgressiva sul basamento carbonatico, costituta da alternanze di sabbie, argille e 128 fig 4 schema evolutivo di un meccanismo di piping sinkhole. a) caso con depositi alluvionali privi di orizzonti di travertino; b) l’orizzonte di travertino funge da struttura metastabile e permette l’allargamento di una cavità. evolutionary outline of a mechanism of piping sinkhole. a) case with alluvial sediments without horizons of travertine; b) the horizon of travertine acts as from meta-stabile structure and allows to the increase of one cavity. s. nisio ghiaie; una copertura vulcanica costituita da piroclastiti rimaneggiate alternate ad epivulcaniti; depositi lacustri con caratteristiche e granulometrie differenti in cui si intercalano diatomiti, travertini intercalati ai prodotti piroclastici. il monte soratte è un horst costituito da due scaglie tettoniche con piani di accavallamento a direzione nnw-sse; esso è delimitato a sud da faglie a direzione meridiana. da tali piani di faglia avviene la risalita di fluidi di origine profonda ricchi di gas; lungo il fosso s. martino si allineano una serie di sorgenti di portata modesta. le acque del lago puzzo in particolare hanno riscontrato un alto tenore di h2s, da cui il nome al lago. il basamento carbonatico al di sotto del lago si attesterebbe ad una profondità compresa tra i 50 ei 100 m; al tetto sono presenti sedimenti costituiti da sabbie, silt e piroclastiti. il lago puzzo, ormai in via di estinzione, si apriva a contatto tra i travertini (sponda sud con spessore di 67 m; di loreto et al., 1999) e le sabbie marine, presenta forma ellittica con asse maggiore orientato in direzione n-s, con profondità molto scarsa (mezzo metro) negli anni ’90, attualmente quasi del tutto interrito a causa degli apporti detritici. dal fondo del lago si originavano sorgenti mineralizzate, ormai completamente obliterate dalla copertura argillosa, ed emissioni di gas che si notano tuttora nei fanghi del fondo. la prima segnalazione storica della formazione del lago puzzo risale al 1856 (28 ottobre), quando si aprì improvvisamente una cavità che subito si riempì d’acqua (ponzi, 1857; ratti, 1857); essa venne attribuita a un fenomeno postvulcanico o al crollo di cavità carsiche. prevalse la seconda ipotesi con cui si spiegò anche la formazione di una seconda cavità, il lago di leprignano, che si formò nel 1895 (brunialti, 1895; folghraiter, 1896; meli, 1896; moderni 1896). altri laghi e piccole cavità ormai estinti si allineano tutti secondo una dislocazione ad andamento n-s; l’estinzione sembra esser proceduta da n verso s: (lago vecchio o lago sinibaldi, con diametro di 500 m, fontana ciocci (250 m), lago nuovo o di leprignano (260 m), pian della casa che si formò nel 1897. nel corso del tempo il lago puzzo si è colmato per apporti detritici provenienti dal vicino torrente di s. martino e si sarebbe riformato nella medesima posizione in tempi più recenti del 1930 accompagnato da emissioni di gas, lanci di detriti, boati (segre, 1948, patrizi, 1967). aallttrrii eesseemmppii nneellll’’aappppeennnniinnoo cceennttrraallee ttoossccaannaa 1) camaiore località le funi: il sinkhole si è formato il 15 ottobre del 1995 con 30 m di diametro e 11 di profondità (buchignani, 2002; buchignani & chines, 2002; d’amato et al., 2002; gonnelli et al., 2002). il substrato risulta costituito da calcare cavernoso affiorante ad una profondità media di circa 140 m, sormontato da alluvioni impermeabili o semipermeabili, con presenza di una potente falda in un acquifero confinato; 2) grosseto, località bottegone: il sinkhole si è formato il 29 gennaio1999 con 153 m di diametro e 17 di profondità (berti et al., 2001; gonnelli et al., 2002), il substrato risulta costituito da calcare cavernoso ad una profondità di circa 200 m, su cui giacciono argille e limi argillosi (in sondaggio riscontrati fino a 110 m di profondità, berti et al., 2002), con presenza di una potente falda di un acquifero confinato termale, nelle vicinanze di una faglia di importanza regionale; 3) lago di s. antonio, poggibonsi (siena), solo da notizie storiche (del zanna, 1901), di genesi incerta, si riescono a trarre informazioni di questo sprofondamento che potrebbe trattarsi di un sinkhole, formato su di un substrato di travertino, posto a non elevate profondità; 4) lago dell’accesa, massa marittima (gr) e lago di s. floriano, capalbio (gr), di origine incerta, si sono formati in base a notizie storiche alla fine del secolo scorso in seguito ad eventi improvvisi, su di un substrato carbonatico a notevole profondità sormontato da depositi continentali. ccoonncclluussiioonnii i casi di sinkhole in italia centrale, concentrati soprattutto nelle piane alluvionali, nelle immediate vicinanze di dorsali carbonatiche, presentano dimensioni diverse da poche decine di metri a diametri e profondità che possono superare i 100 m. in letteratura vengono definiti impropriamente sinkholes fenomeni la cui genesi coincide con le doline di crollo, le doline alluvionali o le doline di subsidenza in roccia. molti autori definiscono sinkhole una cavità di qualsiasi forma che si genera anche per cause antropiche, così come crolli di volte in antiche catacombe, o in miniere dismesse, cave di tufo o crolli del manto stradale sovrapposto a cavità. in questa sede si vuole puntualizzare la differenza tra il fenomeno di sprofondamento in genere, di cui fanno parte tutti i fenomeni sopra elencati, le doline ed i sinkholes. i sinkholes (il cui termine corretto in italiano è camini di collasso) hanno forma sub-circolare e si aprono improvvisamente in terreni di origine continentale a granulometria variabile. la genesi di un fenomeno con queste caratteristiche non è semplicemente carsica (come avviene nelle doline) ma deve necessariamente ammettere un processo di risalita di acque, ricche in gas, che possano generare sifonamento e asportazione di particelle solide, suffosione o piping sfruttando come vie di risalita preferenziali sistemi di faglie e fratture. fenomeni di questo tipo, definiti in questa sede sinkhole in senso stretto, coincidono con quei fenomeni definiti dalla letteratura anglosassone piping sinkhole. pertanto allo stato attuale delle conoscenze poiché non è più possibile ridefinire il termine sinkhole in tutta la letteratura internazionale risulta necessario aggiungere al termine, almeno, un attributo che chiarifichi la genesi e il tipo di fenomeno di cui si sta trattando (piping sinkhole, collapse sinkhole, solution sinkhole e così via). tutti i casi esaminati nell’appennino centrale presentano caratteristiche comuni: 129i fenomeni di sprofondamento ... a) presenza di un substrato carbonatico posto a notevole profondità (oltre i 100 m), b) presenza al tetto del substrato un potente pacco di depositi continentali a granulometria variabile, generalmente impermeabili o semipermeabili c) scarse caratteristiche fisico-meccaniche dei sedimenti di tetto (scarsa, consistenza o uno scarso grado di addensamento); d) presenza di un potente acquifero confinato (falda in pressione) e di sorgenti poste nelle immediate vicinanze con portate elevate; e) origine tettonica delle piane sulle quali si originano i fenomeni (graben o semigraben); f) presenza di importanti dislocazioni tettoniche di faglie e di fratture che attraversano il substrato; g) presenza di gas (radon, metano, elio, anidride carbonica, acido solfidrico); h) presenza di un reticolo di piccole fratture o diaclasi che mette in comunicazione il mezzo permeabile con quello impermeabile. non comune a tutti i casi (piana pontina?, alcuni casi nella piana di s. vittorino?, lago di s. antonio) è la presenza di orizzonti o lenti travertinose poste a profondità intermedia tra il substrato e il piano campagna (3040 m). gli autori che hanno analizzato il problema (ad esempio capelli et al., 2000; bersani & castellano, 2002) manifestano diversità di vedute sulla possibilità di un processo di risalita di fluidi, sifonamento e suffosione su sedimenti continentali di notevole potenza. tale possibilità sembra invece poter dipendere dagli altri elementi sopra elencati, in particolare i meccanismi di piping e suffosione potrebbero sfruttare proprio le linee di maggior debolezza, nonché dal fattore tempo. pertanto i fenomeni di erosione sub-superficiale potrebbero essere richiamati dal basso ed essere collegati ai fenomeni carsici del bedrock attraverso linee tettoniche e fratture. in alcuni casi è possibile che le cavità di superficie possano avere origine per la dissoluzione di sedimenti, quali travertini o altri, a scarse profondità (alcuni metri o poche decine di metri) dal piano di campagna, in molti altri casi la genesi dei sinkholes è da ricercarsi a profondità più elevate nel bedrock carbonatico. bbiibblliiooggrraaffiiaa anelli f. (1959) nomenclatura italiana dei fenomeni carsici. grotte d’italia, 3(3), 3-56, castellana grotte. anelli f. (1965) fenomeni carsici, paracarsici e pseudocarsici. giorn. di geol., 3311(2), 11-35. beck b.f. (1984) sinkholes: their geology, engineering & environmental impact. ed. a.a. balkema/ rotterdam/boston (1984). beck b.f. & wilson w.l. (1987) karst hydrogeology: engineering and environmental applications. ed. a.a. balkema/rotterdam/boston (1987). bersani p. & castellano f. (2002) i sinkhole della piana di s. vittorino (rieti) e il rischio idraulico connesso. in: le voragini catastrofiche, un nuovo problema per la toscana. att. conv. 31 marzo 2000, (gr). regione toscana, 47-61. bersani p., biagi p. f., ferranti c. & piotti a. (2000) gli sprofondamenti della piana di s. vittorino (rieti). l’aquila, 1/2000, 39-48. berti g., canuti p., & casagli n. (2002 a) voragini e sprofondamenti nel territorio nazionale: analisi morfometrica di alcuni casi caratteristici in aree appenniniche. in: le voragini catastrofiche, un nuovo problema per la toscana. att. conv. 31 marzo 2000, gr. regione toscana, 71-81. berti g., canuti p., & casagli n., micheli l., pranzini g. (2002 b) risultati preliminari sullo sprofondamento in località bottegone (grosseto). in: le voragini catastrofiche, un nuovo problema per la toscana. att. conv. 31 marzo 2000, gr. regione toscana, 242-256. billiard a., muxart t., derbyshire e., wang j.t. & dijkstra, t.a. (1992) les glissements de terrain induits parles loess de la province de gansou, chine. annales de gèographie, 556666, 495-515. billiard a., muxart t., derbyshire e., wang j.t. & dijkstra, t.a. (1993) landsliding and land use the loess of gansu province, chine. zeitschrift fur geomorphologie, supplement band 8877, 117-131. bigi g., capelli g., mazza r., parotto m., petitta m.& salvati r. (1999) strutture di collasso nella piana di s. vittorino (fiume velino, lazio): interazione tra circolazione idrica sotterranea e tettonica attiva. convegno conoscenza e salvaguardia delle aree di pianura. ferrara italy, 8-11 novembre 1999. boni c., bono p., calderoni g., lombardi s., & turi b. (1980) indagine idrogeologica e geochimica sui rapporti tra ciclo carsico e circuito idrotermale nella pianura pontina (lazio meridionale). geol. apl. e idrogeol. 1155, 203-247. boni c., cappelli g.& petitta m. (1995) carta idrogeologica dell’alta e media valle del f. velino. system cart, roma. bono p. (1995) the sinkhole of doganella (pontina, plain, central italy). environmental geology, 2266, 48-52. brunamonte f., prestininzi a. & romagnoli c. (1994) geomorfologia e caratteri geotecnici dei depositi di terre rosse nelle aree carsiche degli aurunci orientali (lazio meridionale, italia). geol. rom., 30, 465-478. brunialti a. (1895) il nuovo lago di leprignano. l’illustrazione italiana, 22: 339-340. buchignani v. (2002) indagini relative al fenomeno di crollo verificatosi nell’ottobre 1995 in località “le funi” camaiore capuologo, rapporto di aggiornamento 2001. in: le voragini catastrofiche, un nuovo problema per la toscana. att. conv. 31 marzo 2000, gr. regione toscana, 202-209. buchignani v.& chines c. (2002) indagini relative al fenomeno di crollo verificatosi nell’ottobre 1995 in località “le funi” camaiore capuolog.. in: le voragini catastrofiche, un nuovo problema per la toscana. att. conv. 31 marzo 2000, gr. regione toscana, 176-201. canuti p. (1982) ambienti geologici investigati nell’ambito del sottoprogetto fenomeni franosi. c.n.r. progetto finalizzato conservazione del suolo (1982). capelli g. & petitta m. (1998) la piana di s. vittorino: rischi geologici e idrogeologici. tevere rivista dell’autorità di bacino del tevere, in stampa. 130 s. nisio capelli g., petitta m. & salvati r. (2000) relationships between catastrophic subsidence hazards and groundwather in the velino valley (central italy) – procedings sixth international symposium on land subsidence sisols 2000, ravenna, italy. 1, 123-136. castiglioni g.b. (1986) geomorfologia. opere utet di geografia e discipline affini; 436 pp. catenacci v. (1992) censimento dei dissesti causati dal crollo di cavità sotterranee verificatesi in italia dal dopo guerra al 1990. mem. serv. geol. naz. vol. xlvii. celico p. (1983) idrogeologia dei massicci carsici, delle piane quaternarie e delle aree vulcaniche dell’italia centro-meridionale (marche e lazio meridionali, abruzzo, molise e campania). quad. cassa mezzogiorno, 4 (2). centamore e. & nisio s. (1999) quatenary morphodinamics between the velino and salto valleys. international workshops on large-scale vertical movements and related gravitational processes. rome-camerino, june 21-26, 1999. abstracts, 45. centamore e. & nisio s. (2002 a) quaternary morfodinamic between the velino and salto valleys. studi geol. camerti vol spec. (1999), 3744. centamore e. & nisio s. (2002 b) tettonica e sedimentazione (lias-pleistocene) nella media valle del f. salto (rieti,italia centrale). studi geol. camerti. ii 2003, (in stampa). centamore e. & nisio s. (2003) the effects of uplift and tilting in the central apennine. quaternary international 110011--110022 (2003), 93-101 centamore e., nisio s. & sabatinelli a. (1999) nuovi dati sull’assetto geologico-strutturale e morfotettonico della piana di s. vittorino (“zona d’incontro tra umbria-marche e lazio-abruzzi, lazio nordorientalerieti). boll. serv. geol. naz. (in stampa). ciotoli g., di filippo m., nisio s., romagnoli c. (1998) la piana di s. vittorino: dati preliminari sugli studi geologici, strutturali , geomorfologici, geofisici e geochimica. atti conv. giovani ricercatori di geologia applicata. chieti 22-24 ott. 1998, vol. abs. 200-201. ciotoli g. di filippo m. nisio s. & romagnoli c. (2000) la piana di s. vittorino: dati preliminari sugli studi geologici, strutturali, geomorfologici, geofisici e geochimici. mem. soc. geol. it., 5566, 297-308. colombi a., salvati r., capell i g., sericola a., colasanto f., crescenzi r., mazza r., meloni f. & orazi a. (1999) problematiche da sprofondamento catastrofico nelle aree di pianura della regione lazio. il progetto sinkhole del lazio. convegno conoscenza e salvaguardia delle aree di pianura. ferrara italy, 8-11 novembre 1999. cramer h. (1941) die systematik der karstdolinen. neues jb. miner. geol paläont., 85, 293-382. d’amato avanzi g., puccinelli a., verani m. (2002) la geologia della piana di camaiore in relazione al fenomeno di sprofondamento del 15 ottobre 1995. in: le voragini catastrofiche, un nuovo problema per la toscana. att. conv. 31 marzo 2000, gr. regione toscana, 154-175. del zanna (1901) i laghi di s. antonio in provincia di siena. boll. soc. geol. it., viii. derbyshire e., & mellors t. w. (1988) geological and geotechnical characteristic of some loess and loessic soil from china and britain: a comparison. engineering geology, 2255, 135-175. derbyshire e., wang j., jin z., billard a., egels y., kasser m., jones d.k. c. muxart t. & owen l. (1991) landslide in the gansu loess of china. catena supplement, 2200, 119-145. di filippo m., palmieri m., toro b. (2002) studio gravimetrico del sinkhole di doganella di ninfa (latina). in: le voragini catastrofiche, un nuovo problema per la toscana. att. conv. 31 marzo 2000, gr. regione toscana, 62-70. di loreto e., liberi l., & piro m. (1999) riqualificazione ambientale del geotopo di lago puzzo, comune di fiano romano roma. mem descr. carta geol. d’it., lliivv, 339-346. dramis f. & nisio s. (in stampa) cenni di geomorfologia. note illustrative della carta geol d’italia, f° 358, pescorocchiano. serv. geol. naz.; faccenna c. , florindo f., funicello r., & lombardi s. (1993) tectonic setting and sinkhole features: case histories from western central italy. quaternary proceeding n.3, 47-56. fairbridge (1968) the encyclopedia of geomorphology. ed. reinhold, new york, 1968, 1295 pp. ferrarese f. & sauro u. (2001) le doline: aspetti evolutivi di forme carsiche emblematiche. le grotte d’italia, 2, 25-38. folgheraiter g. (1896) sopra i l nuovo lago di leprignano. frammenti concernenti la geofisica dei pressi di roma, 3, 1-17, roma. ford d. & williams p. w. (1989) karst geomorphology and hydrology. unwin hyman, london, 601 pp. forti p. (2002) evoluzione ipercarsica all’interno di acquiferi termali e in rapporto a possibili problemi di suffosione. in: le voragini catastrofiche, un nuovo problema per la toscana. att. conv. 31 marzo 2000, gr. regione toscana,11-26. guerricchio a. (1982) carsogenesi e movimenti gravitativi nelle formazioni carbonatiche dell'appennino meridionale. atti ii symp. int. "utilizzazione delle aree carsiche", geol. appl. idrogeol., 1177 (2), 161186, bari . jennings j.n. (1985) karst geomorphologykateprint co. ltd, oxford, 293 pp.. klimchouk a., lowe d., cooper a. & sauro u. (1997) gypsum karst of the world. int. j. speleol. 25 (34), 1996, 308 pp.. littlefield j.r., culbreth m.a. upchurch s.b., stewart m.t. (1984) relationship of modern sinkhole development to large scale-pholinear features. in: beck barry f. (1984) sinkholes: their geology, engineering & environmental impact. ed. a.a. balkema/rotterdam/ boston. macaluso t., madonia g., palmieri a., sauro u. (2002) atlante dei karren nelle evaporiti della sicilia (atlas of the karren in the evaporitic rocks of sicily). quaderni del museo geologico “g.g. gemellaro”, 5,dip. di geologia e geodesia, università degli studi di palermo, 143 pp. meli r., (1896) breve relazione delle escursioni geologiche eseguite all’isola del giglio e al lago nuovo di leprignano. ann. scuola applicaz ingegneri, 131i fenomeni di sprofondamento ... 12-16. roma. michetti a.m., brunamonte f., serva l. & whitney r.a. (1994) seismic hazard assessment from paleosismological evidence in the rieti region, centrl italy. bull. ass. eng. geologist. spec. vol., 63-82. moderni p. (1896) il nuovo lago e gli avvallamenti del suolo nei dintorni di leprignano. boll. regio comit. geol., 27: 46-57, roma. monroe w.h. (1970) a glossary of karst terminology. u.s. geol. surv. water sup (1970). mori a. (1983) sulla formazione di alcuni laghetti presso cittaducale. in: la petrografia per tutti. muxart t., billard a., & derbyshire e. & wang j. (1994) variation in runoff on steep unstable loess slopes near lanzhou, china: initial results using rainfall simulation. in: m. j. kirby – process models and theoretical geomorphology (1994), 337-355. newton j.c. (1984) review of induced sinkhole development. in: beck barry f. (1984) sinkholes: their geology, engineering & environmental impact. ed. a.a. balkema/rotterdam/boston. newton j.c. (1987) development of sinkholes resulting from man’s activities in the eastern united states. usgs c-968, 54 pp. nisio s. (in stampa) geologia applicata: movimenti franosi. in: note illustrative della carta geol d’italia, f° 358, pescorocchiano. serv. geol. naz. (in stampa). nolasco f. (1986) sprofondamenti del terreno in località sciamargutta presso cotilia terme. roma nolasco f. (1998) la piana di s. vittorino. contributo allo studio dei processi evolutivi dei rischi e della prevenzione. regione lazioacea. patrizi (1967) sullo stato attuale del lago puzzo (fiano romano lazio) atti de xx congr. geograf. it. marzo-aprile, 1967. soc. geogr. it.: 3-7, roma. ratti f. (1857) sul laghetto di recente formazione nelle vicinanze di leprignano. in corrsp. scient. di roma, scienze, 5, 65-69. riccardi m. (1951) nuove ricerche sulla piana di s. vittorino. boll. soc. geogr. it., iv, fasc. v. segre a.g. (1948) i fenomeni carsici e la speleologia del lazio. ist. geogr. dell’unv, xi, 239 pp., roma sinclair, w.c. (1982) sinkhole development resulting from ground-water, development in the tampa area, florida. usgs wri, 81-50, 19pp. sinclair w.c. & stewart, j.w. (1985) sinkhole type, development and distribution in florida .usgs ms-110, 1 plate sweeting m.m. (1972) karst landform. macmillan, london, 362 pp. tenore g. (1872) sulle azioni chimiche e meccaniche dell’acqua come cagioni attuali modificatrici nella valle del velino nel secondo abruzzo ulteriore (piana di san vittorino). tihansky a.b. & galloway d.l. (2000) land and waterresource development activities increase sinkhole frequency in the mantled karst region of florida. usa. procedings sixth international symposium on land subsidence sisols 2000, ravenna, italy. 1, 77-90. verri a. (1886) la sorgente del peschiera. in: l’annunziatore umbro-sabino. anno iv, n° 38.7 white w.b. (1988) geomorphology and hydrology of carbonate terrains. university press, oxford, 464 pp. wilson w.l. & shock e.j. (1996) new sinkhole data spreadsheet manual (v1,1) subsurface evaluation inc., tampa, florida, 31 pp. 132 ms. ricevuto il 2 dicembre 2002 testo definitivo ricevuto il 13 maggio 2003 ms. received: december 2, 2002 final text received: may 13, 2003 s. nisio imp.geremia& coastal geomorphosites of the isles of lipari and stromboli (aeolian islands, italy): new potential for geo-tourism francesco geremia1 & raniero massoli-novelli2 1dipartimento di scienze della terra, università degli studi di messina, salita sperone 31, 98166 messina email: fgeremia@unime.it 2coordinator of the geosites sigea working group, via della mendola 85, 00135 roma, italy email: massoli@tiscali.it abstract: f. geremia & r. massoli-novelli, coastal geomorphosites of the isles of lipari and stromboli (aeolian islands, italy): new potential for geo-tourism. (it issn 0394-3356, 2005). after illustrating the main geological, volcanological and geomorphological characteristics of the aeolian islands and, in particular, of lipari and stromboli – the two main isles of the archipelago – their most important coastal geomorphosites are individuated. considering their high level of geological and geomorphological interest, two geo-tourism itineraries by boat are planned – one for each island – to promote their coastal landscape of volcanic origin. six coastal geomorphosites or groups of geomorphosites of elevated scientific and educational value are selected for each itinerary. the itinerary for the island of lipari begins in its eastern side with a panoramic view of the famous castle of lipari, built on a imposing rhyolitic lava dome. it continues toward the northern coast, where there are considerable pumice quarries and a rare coarse clastic beach, characterized by the presence of dark volcanic gravels and pebbles and light-coloured pebbles of pumice, to finish in the southern side with the observation of two notable volcanic pinnacles (pietralunga and pietra menalda). the itinerary for the island of stromboli begins from the pier of scari, characterised from a dark-coloured sandy beach and continues toward ginostra, where it is possible to run along the first geological-historical path of aeolian islands. the itinerary continues toward northwest with the impressive panoramic view of the “sciara del fuoco”, a rare landscape in the mediterranean, and to finish around the neck of strombolicchio, the last evidence of a vast volcanic edifice. emphasis is given to the importance of this new kind of cultural tourism, named “geo-tourism”, according the principles of sustainable development and based on the promotion and conservation of the unique geomorphological-volcanological heritage of aeolian islands. riassunto: f. geremia & r. massoli-novelli, geomorfositi costieri delle isole lipari e stromboli (isole eolie, italia): una nuova potenzialità per il turismo. (it issn 0394-3356, 2005). dopo la illustrazione delle principali caratteristiche geologiche, vulcaniche e geomorfologiche delle isole eolie in generale ed in particolare di lipari e stromboli, le due principali isole dell’arcipelago, ne vengono individuati i principali geomorfositi costieri. in base alle valenze geologiche-geomorfologiche identificate vengono progettati due itinerari geoturistici, uno per isola, da dedicare al paesaggio costiero di origine vulcanica e da effettuare in barca. per ogni itinerario sono stati scelti sei geomorfositi o gruppi di geomorfositi, scelti tra i più importanti e con maggiore valenza didattica, e per ognuno di essi è stato progettato uno stop, con osservazioni da effettuare a seconda delle situazioni o dalla barca o a terra. l’itinerario per l’isola di lipari inizia ad est con lo splendido castello di lipari che sorge su un imponente bastione di lava riolitica, prosegue verso nord con le grandi cave di pomice e con la rara spiaggia di porticello, caratterizzata dalla presenza di ciottoli di lava nera e di pomice bianca, per terminare a sud con i due notevoli pinnacoli lavici di pietralunga e pietra menalda, che si ergono in mezzo al mare. l’itinerario per l’isola di stromboli inizia dal molo di scari, caratterizzato da una spiaggia con sabbia vulcanica completamente nera, scende verso ginostra, ove si può percorrere a terra un già collaudato sentiero geologico, continua a nord-ovest con l’impressionante sciara del fuoco, un paesaggio unico nel mediterraneo, e termina di fronte allo scenografico “neck” di strombolicchio, residuo dello smantellamento di un ben più vasto edificio vulcanico. viene sottolineata l’esigenza di questa nuova forma di turismo culturale che è il “geoturismo”, valido sotto il profilo dello sviluppo sostenibile, basato sulla spiegazione, promozione e conservazione del prezioso, talvolta unico, patrimonio geomorfologico-vulcanologico delle isole eolie. keywords: geomorphosites, geo-tourism, lipari, stromboli, aeolian islands, tyrrhenian sea. parole chiave: geomorfositi, geoturismo, lipari, stromboli, isole eolie, mar tirreno. il quaternario italian journal of quaternary sciences 18(1), 2005 volume speciale, 233-244 1. introduction the potential for geo-tourism is high all over sicily, and especially in the aeolian islands. as the geological features of these islands are relevant, the whole archipelago was included in the list of unesco natural assets, on the grounds that: “the volcanic landforms of the aeolian islands represent classic features in the continuing study of volcanology worldwide”. the coastal geomorphosites of the aeolian islands typically witness the history and dynamics of past and recent volcanic events and geomorphological processes affecting the archipelago. they may be analysed from different perspectives: from landscape description to scientific interpretations, from encouraging interest in geological knowledge to examining the economic role of geo-tourism initiatives. the identification and study of coastal geomorphosites from the viewpoint of sustainable tourism is only the first step towards intelligent fruition of the aeolian archipelago. geosite assessment, selection and protection criteria should satisfy not only scientific 234 f. geremia & r. massoli-novelli needs but also the need for social fruition. the fundamental parameters of this type of assessment are essentially as follows: scientific value – educational value – rareness – degree of conservation – visibility and accessibility – extra value, also considering natural istic, archaeological etc. aspects (arnoldushuyzendveld et al., 1995; panizza & piacente, 2002; d’andrea et al., 2003; massoli-novelli, 2003a; 2003b). organising geological and geomorphological excursions allows various advantages, such as promoting the knowledge of earth sciences, which is so poorly appreciated among the population at large. this would offer new professional opportunities to young geologists and naturalists and result in a better distribution of tourists: not only in the months of july and august but also in the spring and autumn. in this way the aeolian territory would benefit from a renewed socio-economic balance, which has long been sought after by local administrations. taking into account the high scientific and educational value of the coastal scenery in lipari and stromboli, two geo-tourism itineraries by boat are planned. six coastal geomorphosites or groups of geomorphosites are individuated for each itinerary. they were analysed through a their detailed geomorphological survey integrated with information provided by scientific and historical literature. the aim of these two geological itineraries is to explain to tourists visiting the aeolian islands every year, that the input of energy into a coastal system via waves is one of the main forces determining coastal processes and how the coast-forming volcanic materials of lipari and stromboli act in response to mechanical wave erosion and mass movement processes. besides, it is important to investigate how the tourism fruition of present coastal scenery can be developed in presence of a high value of vulnerability induced by human activity and, above all, to volcanic hazards consequences. 2. general geological setting the aeolian islands are located in the south-eastern tyrrhenian sea facing the northern coast of sicily (fig. 1). they provide an outstanding record of volcanic island-building and destruction processes and ongoing volcanic phenomena. studied since at least the 18th century, these islands have permitted to investigate on two types of eruption (vulcanian and strombolian) and so have featured prominently in the education of all geoscientists for over 200 years. the archipelago of the aeolian islands is made up of seven main islands (lipari, vulcano, panarea, stromboli, salina, filicudi ed alicudi) and several seamounts and islets, along the internal margin of the apennine -maghrebian chain. it is correlated to the complex geodynamic situation of the mediterranean area which has been site of the collision between the african and eurasian plates, with a trending convergence (barberi et al., 1974). the aeolian islands are the part emerged of a large submarine volcanic basement extending for around 200 km, having a typical arc-shaped structure. the depth of the basement from which the seven islands emerge ranges from 1000 and the 2000 m b.s.l. they consist mainly of volcanic products, spanning in age from about 400 ka to the present, and subordinately from late-quaternary marine deposits. vertical crustal movements of the volcanic edifices have been interpreted as being the result of interaction between episodic eruptive events and neo-tectonic processes, both transitory and active on a local scale (calanchi et al., 1996; 2002). seismic and volcanic activities linked to quaternary tectonics and marine erosion, both pleistoceneholocene and present, are the main factors responsible for the great coastal diversity of the aeolian islands, both emerged and submerged (romagnoli et al., 1993). the volcanic coastal landscape of aeolian islands is particularly suitable for physical processes (e.g. mechanical wave erosion, mass movement and longshore sediment transport). these processes have played an important role in the development of present coastal scenery with formation of a great diversity of coastal features (e.g. plunging and composite cliffs, embayed and pocket beaches, sea arches and caves, islets and stacks, etc.). all these coastal features develop chiefly along the structural weaknesses (e.g. the joints and the fault planes) or as the result of a differential erosion of dykes. instead, other marine processes, such as bioerosion and chemical and salt weathering, are absent or insignificant. fig. 1 location of the isles of lipari and stromboli in the aeolian archipelago (south-eastern tyrrhenian sea). inquadramento geografico delle isole di lipari e stromboli nell’arcipelago eoliano (mar tirreno sudorientale). 3. the isle of lipari 3.1. geological framework lipari is the largest island of the archipelago with a surface extending for 38 km2, a maximum length of about 9.5 km (north-south) and a width of 7 km (eastwest). during the neolithic age it was one of the rare sources of obsidian in the mediterranean and it was also famous as the most important trading station for kaolin and pumice. from a geological and volcanic viewpoint, the isle of lipari – like stromboli is the emerged part of a large volcanic edifice, rising from the sea floor at a depth of about 1000 m b.s.l.. although the geological evolution of lipari is complex, it can be divided in two phases of different volcanic activity, separated by a long period of dormancy (about 45,000 years), revealed by evident subaerial and marine erosional surfaces. the volcanic activity of the first period (paleolipari) starts about 230,000 years bp with the emission of products composed of basalt and andesite. post-erosional volcanic activity begins at about 42,000 years bp, with very different eruptive styles and magma composition, as testified by the emission of evolved magmatic products (rhyolite – obsidian lava flows) and large amounts of surge deposits (pumice deposits). the last volcanic activity in lipari occurred between 16,800 and 1,400 years bp and is located in its north-eastern sector. this important activity results in a substantial emission of pumice surge deposits on monte pilato and of exceptional obsidian and rhyolite lava flows in rocche rosse (pichler, 1980; tranne et al., 2000). recent dating establishes that the last eruption took place about 1400 years bp, covering the fourth and fifth century roman remains in the acropolis of lipari with a thin layer of pumice (calanchi et al., 1996; tranne et al., 2000). the coastal scenery of lipari is varied and rugged; it is characterised by the presence of headlandembayment sequences with numerous sea-stacks, arches and caves. embayed beaches with sands, gravel and cobbles are principally prevalent along the eastern and northern side of the island, from the port of lipari to the headland of punta del legno nero. high and steep, plunging and composite cliffs dominate along the western and southern coast; although boulder beaches are present on the south-western coast between punta le grotticelle and punta crepazza, and a very sorted sandy beach, nourished naturally by the adjacent landslide and detrital deposits, is embayed in the valle muria bay. in addition, mechanical wave erosion and mass movement are the dominant exogenetic processes along the coast of lipari (fig. 2). 3.2. coastal geomorphosites and geo-tourism there are numerous pathways on the isle of lipari connecting various localities but some of these tracks are quite difficult to follow, so it is more interesting to explore the extraordinary coastal scenery of lipari sailing around the island by boat (fig. 2). a complete tour around the island, taking about 9 hours and including two stops at porticello and valle muria beaches, is proposed. it is better to sail round the island anticlockwise, so as to have a good view of the eastern side during the morning and the western side during the afternoon with a spectacular panoramic 235coastal geomorphosites of ... view of its southern side at sunset. in this way the following coastal geomorphosites of volcanic origin can be observed very well: stop n. 1 – rocca del castello cliff the famous castle of lipari is built on a strongly eroded rhyolitic lava dome, linked to the eruptive centre of monte guardia (some 20,000 years bp). at the base of cliff, evidences of progressive rock falls can be observed, which have brought the margin of the cliff up to the castle’s ancient spanish walls. next to the rocky cliff, the interaction between endogenetic volcanic phase and exogenetic processes (e.g. mechanical wave erosion and mass movement) can be observed, together with evidence of human activities and works carried out to protect ancient buildings (table 1). tab. 1 dominant landform and processes, vulnerability and accessibility of the first stop selected around the coast of the island of lipari. morfologia e processi dominanti, vulnerabilità ed accessibilità del primo stop selezionato intorno alla costa dell’isola di lipari. 236 stop n. 2 – campo bianco pumice quarry and porticello beach the porticello beach is characterised by the presence of berms with dark volcanic gravels and pebbles and bigger, roundish, light-coloured pebbles of pumice (table 2). at north of porticello beach the rhyolite-obsidian lava flow of rocche rosse (1,400 years bp) shows spectacular convoluted flow foliation structures visible along the abandoned cliff. to the south on the eastern side of monte pilato there is the very large campo bianco pumice quarry which has long quays on the coast, where the extracted rock is loaded onto ships (fig. 3). in the past the discarded materials from the pumice quarry formed a completely white gravelly f. geremia & r. massoli-novelli fig. 2 the geological-tourism itinerary around the isle of lipari. location, dominant landforms and processes of the main coastal geomorphosites. l’itinerario geologico-turistico intorno all’isola di lipari. ubicazione, morfologia e processi dominanti dei principali geomorfositi costieri. 237 beach, much appreciated by tourists; at present the pumice extraction is incompatible with a sustainable development of the island. stop n. 3 – le torricelle sea stack the sea stack of le torricelle, some 32 m high, is an interesting coastal geomorphosite, characterised by plunging cliffs with a pillar-like structure originated by effusive activity of paleolipari volcanic centres (223,000 150,000 years bp) and covered by conglomerate levels with pebbles and pyroclastic deposits. its upper coastal geomorphosites of ... tab. 2 dominant landform and processes, vulnerability and accessibility of the second stop selected around the coast of the island of lipari. morfologia e processi dominanti, vulnerabilità ed accessibilità del secondo stop selezionato intorno alla costa dell’isola di lipari. tab. 3 dominant landform and processes, vulnerability and accessibility of the third stop selected around the coast of the island of lipari. morfologia e processi dominanti, vulnerabilità ed accessibilità del terzo stop selezionato intorno alla costa dell’isola di lipari. fig. 3 lipari, stop n. 2. the large pumice quarry at campo bianco. lipari, stop n. 2. l’estesa cava di pomice di campo bianco. 238 extremity appears flattened by sea abrasion and is to be linked to elevated marine terraces recognised along the western coast of lipari (table 3). the ancient uplifted shorelines are the result of interaction between sealevel fluctuations in the late quaternary and vertical movement of the volcanic island (calanchi et al., 2002). stop n. 4 – valle muria bay valle muria is a narrow and elongated wave-dominated embayed beach confined between the two headlands of and punta di levante. tuff and lapilli tuff (hydromagmatic activity) and scoriae of first period (223,000 150,000 years bp) crop out along the promontory of punta di ponente; they are locally characterised by fumarole levels, ranging in colour from yellow to white and red (table 4). at punta di levante the remains of an ancient lava dome, belonging to the punta del perciato eruptive complex, have been overlaid by a massive brown ash tuff deposit (brown tuffs) with intercalation of one black coarse ash layer related to the salina volcanic activity (tranne et al., 2000). stop n. 5 – punta del perciato headland the rocky headland of punta del perciato is the last evidence of a thick, rhyolitic lava dome, dating from 20,300 – 42,000 years bp. concentric ramp structures with excellent examples of onion-like flux exfoliation can here be observed. in addition, the site is characterised by the presence of a sea arch with vertical walls; it is a significant indicator that a strong wave action in all two sides of the promontory (table 5). stop n. 6 – pietralunga and pietra menalda pinnacles the beautiful pietralunga and pietra menalda pinnacles, some 60 and 25 m high, are the last witnesses of a wide volcanic structure which was dismantled by marine erosion (fig. 4). they were formed by the same volcanic activity of fourth period (42,000 20,300 years bp) which originated the promontory of punta del perciato. these two sea stacks are characterised by steeply descending cliffs that pass far below sea level without any shore platform and are attacked continuously by wave erosion (table 5). 4. the isle of stromboli 4.1 – geological framework stromboli is the most active volcano in europe and is famous worldwide on account of its typical “strombolian” activity, which consists of ejection of ash, lapilli and lava bombs with rare lava effusions of short duration. stromboli is also considered an extremely important field laboratory for volcanic hazard assessment. it is the northernmost island of the aeolian archipelago and covers an area of 12.2 km2. stromboli with an elevation of 924 m a.s.l. forms a steep and f. geremia & r. massoli-novelli tab. 4 dominant landform and processes, vulnerability and accessibility of the fourth stop selected around the coast of the island of lipari. morfologia e processi dominanti, vulnerabilità ed accessibilità del quarto stop selezionato intorno alla costa dell’isola di lipari. fig. 4 lipari, stop n. 6. the beautiful 60 m high pietralunga volcanic pinnacle. lipari, stop n. 6. l’eccezionale faraglione di pietralunga, alto 60 metri s.l.m. uniform volcanic cone which rises from a depth of about 2400 m in the tyrrhenian sea. the island of stromboli was affected by several collapses, which took place in two main stages: the older one, characterised by three concentric caldera collapses and several pyroclastic eruptions related to a flank collapse toward south-east, and the younger one, characterised by two sector collapses, one flank collapse towards north-west and predominant lava effusions (pasquarè et al., 1993). the geological evolution of stromboli is recorded in its subaerial part for a time span from about 100,000 years bp up to the present. four major periods (paleostromboli, vancori cicles, neostromboli and recent stromboli) have been recognised and further subdivided into 30 volcano-stratigraphic units. pyroclastites (ignimbrites, surge and lahar deposits) predominate over lavas (latites) during the first two periods, while the more recent products are generally basalts, with shoshonitic composition (horningkjarsgaard et al., 1993; rosi, 1980). as regards volcanic hazard, stromboli is at present characterised by a peculiar state of permanent activity consisting of mild intermittent explosions and continuous gas steaming. from time to time this normal activity is interrupted by eruptive crises characterised by either lava emission or more violent explosions. there are on average 2.1 events per year of major explosions with fallout of large blocks and incandescent bombs up to a distance of about 1.5 km from the craters. more violent paroxysms with a larger volume of ejected material and a broader spectrum of phenomena have an occurrence of one event every 10-15 years (barberi et al., 1993). the island of stromboli has a high vulnerability to volcanic hazards (e.g. explosive eruption and volcanic landslides) and large tsunamis could also take place as the effect of huge landslide at “sciara del fuoco” (tinti et al., 1999). the morphology of this island is rugged and jagged, owing to continuous volcanic eruptions and marine erosional processes. flat areas, made up of emerged marine terraces, are very rare. they are site of the two main human settlements: the villages of stromboli in the north-east side and of ginostra in the south-west side. the coastal scenery is characterised by the presence of cliffs with more or less gentle slopes. only on the north-east side the coastal slope is gentle and grass-covered with rich soil and fields under cultivation. some sandy and pebbly beaches are also found, mainly along the north-east side. a dark-coloured sandy foreland, between scari and punta lena, extends out from the coast towards the islet of strombolicchio. it is a significant indicator that two dominant swells are in opposition (fig. 5). 4.2 – coastal geomorphosites and geo-tourism stromboli is an island at high volcanic risk, where it is no longer possible to walk along high-altitude footpaths without an authorised guide. it is, therefore, advisable to explore its rugged coastal landscape by sailing along it, thus reaching also the islet of strombolicchio, some 1.3 miles away from stromboli’s north-eastern coast. the complete tour by boat around the island takes about 5 hours, including a stop at the village of ginostra (fig. 5). starting from the pier of scari and proceeding clockwise, the most important coastal geomorphosites of volcanic origin are as follows: stop n. 1 – le schicciole valley along the eastern coast, three steep small valleys filled with pyroclastic material can be seen. these are volcano-tectonic collapse structures, named “le schicciole” and formed some thousands of years ago along the western flanks of stromboli volcano. they are similar on a smaller scale to the famous “sciara del 239coastal geomorphosites of ... tab. 5 dominant landform and processes, vulnerability and accessibility of the fifth and sixth stop selected around the coast of the island of lipari. morfologia e processi dominanti, vulnerabilità ed accessibilità del quinto e sesto stop selezionati intorno alla costa dell’isola di lipari. fuoco” depression, which will be described in one of the next stops. in fact, also in this case, the hollow spaces left after collapse were later filled by soft and cohesionless pyroclastic materials with respect to the harder, ancient flows which form a sort of container (table 6). stop n. 2 – secche di lazzaro underwater arches in the area surrounding secche di lazzaro the coast has an exposure between 90° and 120°n and is still sheltered from the strong north-westerly mistral wind. since sea dismantling activity is less intense, the “lazzaro pyroclastites” (some 4,000 years bp) crop out on top of the neostromboli lava flows (some 14,000 years bp). here there are, therefore, excellent conditions for observing the various degrees of incidence of erosional processes on the lavas and dip-downstream pyroclastic deposits. nearby, at secche di lazzaro, snorkelling allows the viewing of magnificent rock arches, appearing a few meters below the sea surface. these structures were carved into pyroclastic deposits by wave-motion when the sea level was lower than it is now (table 7). 240 f. geremia & r. massoli-novelli fig. 5 the geological-tourism itinerary around the isle of stromboli. location, dominant landforms and processes of the main coastal geomorphosites. l’itinerario geologico-turistico intorno all’isola di stromboli. ubicazione, morfologia e processi dominanti dei principali geomorfositi costieri. stop n. 3 – ginostra secche di lazzaro (first “geological-historical path” of the aeolian islands) ginostra is a small coastal village naturally isolated from the lava flows of the ever-active stromboli volcano. the village is made up of a cluster of very basic, simple houses, still with no running water or electricity. owing to the high landslide susceptibility of the volcano’s flanks, there are no road connections, not even footpaths, between the vil lages of ginostra and stromboli. the passengers arriving by ferryboat from naples, messina and the other aeolian islands are transferred into small boats that eventually take them to the “pertuso”, the small natural harbour dug by the sea into the black basalt lava. at present, the construction of a little harbour similar to that of stromboli is in progress, in order to offer safe conditions to the local population and the numerous summer tourists (table 7). some years ago, the first “geological-historical path” of the aeolian islands, from ginostra to secche di 241coastal geomorphosites of ... tab. 6 dominant landform and processes, vulnerability and accessibility of the first stop selected around the coast of the island of stromboli. morfologia e processi dominanti, vulnerabilità ed accessibilità del primo stop selezionato intorno alla costa dell’isola di stromboli. tab. 7 dominant landform and processes, vulnerability and accessibility of the second and third stop selected around the coast of the island of stromboli. morfologia e processi dominanti, vulnerabilità ed accessibilità del secondo e terzo stop selezionato intorno alla costa dell’isola di stromboli. lazzaro, was opened (fig. 6). it is about 1 km long and its volcanological features of neostromboli lava flow (13,800 years bp) are particularly interesting: pahoehoe basalt lavas on the path, latitic dykes cutting through it, ignimbrite deposits and their spectacular erosional features, high-energy coastal erosion, with enormous rounded basalt stones and underwater arches carved into pyroclastic rocks (massoli-novelli, 1999). stop n. 4 – punta chiappe dykes punta chiappe is the site where the major volcanological and geomorphological features of stromboli can be observed better than anywhere else: the vertical lava dykes (latitic in type of timpone del fuoco about 6,000 years bp) which radially cut through the main volcanic edifice. owing to differential erosion, these dykes clearly emerge as brownish walls from the soft and black pyroclastites which surround them. this series of vertical dykes runs along the west flanks of the collapsed structure which gave origin to the “sciara del fuoco”, described below. at the foothill of the volcano the dykes stretch out into the sea giving rise to a series of small sea stacks, strongly exposed to northern wave activity (table 8). stop n. 5 – sciara del fuoco depression the “sciara del fuoco” depression is an exceptional coaxial semicircular escarpment, defined as a large horseshoe-shaped amphitheatre, opened at the northwest end continuing below sea level (romagnoli et al., 1993). it is located along the western slope of the island where most of the volcano’s lava and explosive products are accumulated. this slope is considerably high – some 400 m a.s.l. – with a slope angle of about 35°, and offers an impressive view when observed from a boat. the “sciara del fuoco” is formed as consequence of the youngest flank collapse of stromboli volcano (pasquarè et al., 1993) and it is made up of lateral lava flows and cohesionless deposits constantly moving along the slope. these deposits are composed of surge materials, such as scoriae, pumice and volcanic sand, erupted from the volcano’s active vents, which are located in a depression called “fossa” at an altitude of 700 m. the origin of this concave landform dates from 510,000 years ago, following a series of volcano-tectonic collapses (13,800 years bp) which led to the formation of a 2 km long longitudinal depression which continues underwater in a large submarine canyon up to a depth of 1700 m. in its more superficial part, the walls of the canyon are 150-200 m high and decrease progressively until they gradually disappear beyond 1000 m in depth (romagnoli et al., 1993). the floor of this submarine depression constantly receives the materials erupted by the volcano, offering spectacular views of great interest for geo-tourism as well as for volcanological excursions (table 8). stop n. 6 – strombolicchio neck the neck of strombolicchio (about 49 m a.s.l.) is the only emerged evidence of the earliest evolutional stage (some 200,000 years bp) of stromboli volcanism. it corresponds to the calcalkaline and andesite-basalt compositional neck of a previous volcanic edifice which was completely dismantled by wave-motion (calanchi et al., 1996). owing to its peculiar structure with steep cliffs and position at some 2 km in direction of north-east from stromboli, the islet of strombolicchio, with a powerful lighthouse at the top, has a particular meaning in the social perception of both residents and tourists; consequently, the understanding and promotion of its peculiar volcanological and geomorphological features is of considerable relevance (table 9). 5. conclusions islands are fragile ecosystems with a very delicate balance between environmental, economic and social activities and requirements. it is widely acknowledged that islands should be areas singled out for priority interventions concerning conservation policies and sustainable development set up by public boards, in order to better define developing projects and related conservation actions. these goals may be attained by means of properly planned, well-targeted and culturally innovative interventions. although the classical tourist approach to the aeolian islands can offer plenty of enjoyable leisure activities, it may leave the culturally motivated tourist with a sense of bitterness and frustration, resulting from the lack of appropriate structures capable of appraising the numerous and important geo242 f. geremia & r. massoli-novelli fig. 6 stromboli, stop 3. panoramic viewpoint from south-west of the geological-historical path from ginostra (left) to secche di lazzaro (right). stromboli, stop 3. panoramica da sud-ovest del sentiero geologico-storico da ginostra (a sinistra) a secche di lazzaro (a destra). logical and geomorphological peculiarities of this archipelago. hence the need to provide visitors with alternative routes which take in the classical tourist destinations of these islands, but also leave plenty of space for the satisfaction of new cultural needs. the coastal geomorphosites of lipari and stromboli represent a good example of volcanism controlled by marine processes with a high scientific and educational value. the reconstruction of constructive and destructive phases, leading to present coastal scenery, is essential for a systematic knowledge of the archipelago’s geomorphosites. high levels of vulnerability induced by human activity are perceptible in the eastern side of lipari for the reason that the pumice extraction activity continues and the tourism installations are increasing. instead, very high levels of vulnerability to natural hazards (e.g. explosive eruption and volcanic landslides) are existing in stromboli, mainly along the north-west side. 243 tab. 9 dominant landform and processes, vulnerability and accessibility of the sixth stop selected around the coast of the island of stromboli. morfologia e processi dominanti, vulnerabilità ed accessibilità del sesto stop selezionato intorno alla costa dell’isola di stromboli. tab. 8 dominant landform and processes, vulnerability and accessibility of the fourth and fifth stop selected around the coast of the island of stromboli. morfologia e processi dominanti, vulnerabilità ed accessibilità del quarto e quinto stop selezionato intorno alla costa dell’isola di stromboli. coastal geomorphosites of ... therefore, according the principles of sustainable development, emphasis is given to the importance of this new form of cultural tourism, named “geo-tourism” finalised not only to promotion and conservation of the coastal landscape of volcanic origin, but also to link opportunities of tourism fruition with the problem of the vulnerability to volcanic hazard consequences. references arnoldus-huyzendveld a., gisotti g., massoli-novelli r. & zarlenga f. (1995) i beni culturali a carattere geologico: i geotopi. un approccio culturale al problema geologia tecnica e ambientale, 4, pp. 35-47. barberi f., innocenti f., ferrara g., keller j. & villari l. (1974) evolution of eolian arc volcanism (southern tyrrenhian sea) earth planet. science letters, 21, pp. 269-276. barberi f., rosi m. & sodi a. (1993) volcanic hazard assessment at stromboli based on review of historical data acta vulcanologica, 3, pp. 173188. calanchi n., rossi p.l., sanmarchi f. & tranne c.a. (1996) guida escursionistico vulcanologica delle isole eolie ed. centro studi ricerche storia problemi eoliani, 203 pp. calanchi n., lucchi f., pirazzoli p., romagnoli c., tranne c.a., radtke u., reyss j.l. & rossi p.l. (2002) late-quaternary and recent relative sea-level changes and vertical displacements at lipari (aeolian islands) journ. of quaternary sciences, 17 (5-6), pp. 459-467. d’andrea m., colacchi s., gramaccini g., lisi a. & lugeri n. (2003) un progetto nazionale per il censimento dei geositi in italia geologia dell’ambiente, sigea, 1, pp. 25-33. horning-kjarsgaard i., keller j., koberski u., stadlbauer e., francalanci l. & lenhart r. (1993) geology, stratigraphy and volcanological evolution of the island of stromboli, aeolian arc, italy acta vulcanologica, 3, pp. 21-68. massoli-novelli r. (1999) an important italian geosite: the volcano-island of stromboli (sicily) proceed. iii intern. symp. progeo on the conserv. of the geolog. heritage, madrid, november 23-25, 1999, pp. 410-414. massoli-novelli r. (2003a) una strategia per la geoconservazione: il geoturismo geologia dell’ambiente, sigea, 1, pp. 17-24. massoli-novelli r. (2003b) geositi, geoturismo e sviluppo sostenibile geologia dell’ambiente, sigea, 1, pp. 167-170. panizza m. & piacente s. (2002) geositi nel paesaggio italiano: ricerca, valutazione e valorizzazione. un progetto di ricerca per una nuova cultura geologica. geologia dell’ambiente, sigea, 2, 3-4. pasquarè g., francalanci l., garduno v.h. & ribaldi a. (1993) structure and geologic evolution of the stromboli volcano, aeolian islands, italy acta vulcanologica, 3, 79-89. pichler h. (1980) the island of lipari in: “the aeolian islands. an active volcanic arc in the mediterranean sea”. rend. soc. it. miner. petrol., 36 (1), pp. 415-440. romagnoli c., kokelaar p., rossi p.l. & sodi a. (1993) the submarine extension of sciara del fuoco feature (stromboli isl.): morphologic characterization acta vulcanologica, 3, pp. 91-98. rosi m. (1980) the island of stromboli in: “the aeolian islands. an active volcanic arc in the mediterranean sea”. rend. soc. it. mineral. petrol., 36 (1), pp.345-368. tinti s., bortolucci e. & romagnoli c. (1999) – modeling a possibile holocenic landslide-induced tsunami at stromboli volcano, italy phys. chem. earth, 24, pp. 423-429. tranne c.a., calanchi n., lucchi f. & rossi p.l. (2000) geological sketch map of lipari (aeolian islands, italy) ed. dip. scienze della terra e geologicoambientali, università di bologna. 244 f. geremia & r. massoli-novelli ii quaternario 7 (1) , 1994, 655-676 premessa guida all'escursione nell'area-tipo del villafranchiano (villafranca d'asti, 23-24 giugno 1994) la presente guida si propane di il/ustrare l'escursione che e stata effettuata a conclusione def convegno "ii significato def vi/lafranchiano nelle successioni plio-pleistoceniche" (peveragno, cuneo, 20-24 giugno 1994). nella prima giornata def congresso sono stati illustrati i risultati piu significativi def lavoro di revisione def/a successione-tipo def villafranchiano di villafranca d'asti effet­ tuato come preparazione al convegno. scopa dell'escursione e stato quello di visitare, illustrandoli, gli affioramenti piu significativi def/a successione. per praticita, la faro il/ustrazione, nelle pagine che seguono come e stato fatto su/ terreno nel corso dell'escursio­ ne sara a cura solo di a/cuni dei ricercatori che hanno preso parte al complesso lavoro di revisione; e owio che i dati e le interpreta­ zioni esposti rappresentano ii risultato de/ /avoro di tutti coloro che hanno preso parte al/a revisione, i cui nomi figurano nella relativa monografia i/lustrativa e che qui citiamo per ii doveroso riconoscimento: p. boano e m.g. forno per ii rilevamento geo/ogico e la ricostruzione stratigrafica; g. bas/lie/ per le ana/isi e le interpretazioni sedimentologiche; g. belluomini per le datazioni con gli amminoacidii; g. pavia ed e. ferrero per lo studio def/a biostratigrafia def/a successione marina; r. berto/di, r. caramlello e a. zeme per la palinostratigrafia; e. martinetto e h.d. mal per lo studio dei macroresti vegetali; f. campanino, a. stefani, p. boano e 5. olivero per le ricerche storico-bibliografiche; a. clangherottl, d. esu, o. girotti ed e. gllozzl per lo studio def/a malacofauna e dell'ostracofauna; m. giardino per l'analisi e l'interpretazione dei dati struttura/i; a. perotta e g. genovese per le analisi e le interpretazioni geotecniche; f. carrara e a. moscariello per le indagini tefrocronologiche; a. vlolanti per le indagini e le interpretazioni de/le faune a foraminiferi; p. ambrosetti, a. azzaro//, g. ficcare/11, s. gentili, f. lkome equlle, a. mottura, b. sala e d. torre, per lo studio dei vertebrati. mentre la monografia che illustra i risultati def/a revisione e al/a qua/e si rinvia per l'inquadramento def problema e per i dettagli relativi ai diversi aspetti trattati, e strutturata secondo lo schema tradiziona/e di uno studio geo/ogico, nell'articolazione dell'itinerario dell'escursione, e conseguentemente nella descrizione dei singoli punti di fermata che vengono proposti nella guida, si e ritenuto opportuno seguire, come fi/o conduttore, quello di far ripercorrere ai partecipanti ii tragitto ideale seguito dagli autori def/a revisione per giungere a formulare ii mode/lo interpretativo proposto a conclusione def faro /avoro. l'escursione ha toccata, pertanto, in successione i seguenti temi: 1) individualita def complesso di depositi fluviali terrazzati post-villafranchiani che costituiscono in superficie l'altopiano di poirino; 2) evidenza e singolarita morfologica def/a zona di deformazione def t. traverso/a che interrompe verso est l'altopiano stesso; 3) stratigrafia def complesso lnferiore def/a successione villafranchiana; 4) caratteri e significato def/a superficie di erosione di cascina viarengo; 5) stratigrafia def complesso superiore def/a successione villafranchiana; 6) presenza dei depositi fluviali terrazzati post-villafranchiani sulle sommita e $ui versanti dei rilievi dell'astigiano. l 'escursione si proponeva soprattutto come occasione di discussione e di confronto con quei partecipanti che operano in altre aree sul/o stesso tipo di problematica. ii programma non prevedeva quindi mo/ti punti di fermata ed i tempi dedicati ad ogni singolo stop sonb stati f/essibili in modo da consentire uno spazio sufficiente a/le discussioni che ii faro esame, ci si augura, abbia stimolato. quando non e stato possibile visitare alcuni dei punti di fermata previsti, in re/azione anche a/le condizioni meteorologiche dei giorni in cui e stata effettuata l'escursione, la guida propane comunque una faro descrizione in modo da consentire a coloro che fossero inte­ ressati un faro esame in altra occasione. ii mese di giugno, se da un lato si presta per tutta una serie di motivi per effettuare un convegno, non puo certo essere conside­ rato idea/e per un'escursione in un paesaggio collinare come quel/o meta di questa escursione: jo sviluppo de/la vegetazione in que/ mese costituisce certamente un notevole ostacolo a/le osservazioni di carattere morfologico. pertanto i partecipanti furono invitati a consultare con frequenza la carta al/a sea/a 1:50.000 riportata in figura 3 (con indicazione dell'itinerario) che si e ritenuta essere di aiuto per questo aspetto def/a problematica. la stagione estiva e stata comunque ritenuta favorevole al/a visita degli affioramenti; a proposito di questi ultimi e da ricordare che, interessando formazioni sciolte fortemente erodibili, e possibile che tra le descrizioni forni­ te in questa guida e le situazioni che si andavano esaminando nel corso dell'escursione sia soprawenuto qua/che cambiamento: di questo e stato data canto nell'illustrazione che e stata fatta verbalmente ad ogni stop. 656 fig. 1 percorso di awicinamento all'itinerario dell'escursione. route to the post-congress tour localities. l' escursione percorso di avvicinamento l'itinerario geologico nell'area-tipo de/ villafranchiano ha inizio 90 km circa a nne del centro congressi di perveragno (fig. 1 ). ii pullman percorrera inizialmente (primi 10 km circa) la strada comunale che corre sull'altopiano di beinette, lembo di un complesso di conoidi coale­ scenti, di eta pleistocenica inferiore, lega­ te ai bacini dei t. ellero e pesio . attraversata la strada provinciale cuneo­ mondovl, raggiungera successivamente, dopo un percorso di 23 km, l'abitato di fossano. in questo tratto la strada si svi­ luppa sul settore de/la pianura piemontese meridionale costituito dal grande conoide de/ t. stura di demonte. la superficie e di eta pleistocenica superiore ed e su questa superficie che si e verificato ii fenomeno di traciniazione de/ f. tanaro (cfr. stop 1): tra s. albano di stura e fossano si attraversa l'ampia e profonda incisione de/ t. stura di demonte, prodotta dal "ringiovanimento" conseguente al fenomeno di tracimazione stesso. le scarpate di questa incisione ed in parte ii suo fondo (a monte de/ ponte) sono modellati nei sedimenti sabbioso-ghiaiosi di caratteristico colore giallastro che costituiscono ii primo !ermine de/la suc­ cessione regressiva pliocenica, nel quale sacco ha proposto l ' istituzione de / "fossaniano". da fossano, proseguendo in direzione nord lungo la "strada reale", si fiancheggia ii lato occidentale dell'altopiano di fossano che, unitamente a quelli di trinita e magliano a/pi, situati piu a sud, rappresenta l'espressione morfologica dell'anticlinale vivente di fossano. questa struttura deforma la copertura neoautoctona messiniano-quaternaria nel settore sudorientale de/ bacino piemontese meridionale: la sua evoluzione recente ha rappresentato una delle cause de/la tracimazione de/ f. tanaro. la strada prosegue poi sempre verso nord per circa 24 km fino a raggiungere carmagnola. in questo tratto torna a correre sulla superficie del conoide pleistocenico superiore de/ t. stura di demonte. in questa superficie, pochi chilometri ad est della strada percorsa dal pullman, e conservato l'alveo abbandonato dal "paleotanaro", cioe l'originaria prosecuzione di questo corso d'acqua verso nnw prima de/ fenomeno di tracimazione , quando conflui­ va nel f. po in corrispondenza all 'attuale carmagnola (fig. 2). dalla circonvallazione di carmagnola si imbocca la strada provinciale per poirino villanova d'asti: questa corre sull 'altopiano di poirino, propaggine orientale de/la pianura piemontese meridionale (fig. 2). da villanova si prende a destra la strada provinciale per ferrere, lungo la quale ha inizio l'itinerario geologico. ltinerario geologico l'itinerario prende origine lungo la strada provinciale tra villanova d'asti e valfenera (fig. 3). stop 1: dusi no (a circa 1 km dal bivio per valfenera , in comune di dusino) ii paesaggio che fiancheggia entrambi i lati della strada, ben visibile dal pullman, e quello dell'altopiano di poirino; ii pullman ha comincia­ to a percorrere questa unita morfologica dopo aver superato l'abitato di carmagnola: e da sot­ tolineare che lunge la strada non si e incontrata alcuna soluzione di continuita tra la pianura piemontese meridionale e l'altopiano di poirino ii quale si configura quindi come una propaggine verso est della precedente (ctr. fig. 2). morfologicamente, la superficie dell'altopiano di poirino si presenta articolata in una serie di blande ondulazioni: queste hanno un dislivello 657 stop 1 ----deposit! fluvlali terrazzatl postvlllafranchianl --~-----------~~~~~~~~ maretto ~ ccessione_ marina prevlllafranchiana ---...:..__; ---:-.. -· relative medio di 10 m e mostrano andamento curvilineo in pianta. osservando la carta di figura 4 si pub consta­ tare come queste forme corrispondano a origi­ nari meandri fluviali, abbandonati dal corso d'acqua che ii ha model­ lati nella lase iniziale del loro processo di "inca­ stramento"(1). i depositi in cui queste forme sono conservate sono limi argillosi di esondazione fluviale molto omoge­ nei, di colore bruno-gial­ lastro (1 o yr 5/4 nelle notazioni delle munsell soil color charts): in questo settore mostra­ no spessore di qualche (1) ctr. forno m.g. (1980) evidenza di un drenaggio abbandonato nel settore settentrionale de/l'altopiano di poirino {torino). geogr. fis. dinam. quater.,3, 61-65, 3 ff. fig. 2 l'altopiano di poirino costituisce la pro­ paggine verso est della pianura piemontese meri­ dionale. the poirino plateau is the eastward extension of the southern piedmont plain. 658 fig. 3 ltinerario dell'escursione: con la linea continua e indicato l'itinerario del 23 giugno; con linea tratteggiata l'itinerario del 24 giugno. the post-congress tour itinerary: the 23rd june route is marked with the solid line; that of the 24th july with the dashed line. metro (max. 10 m) e presenta­ no localmente, dispersi, ciot­ toletti con varia natura litologica. nei rari punti in cui e possibile osservare la loro superficie di appoggio basale (non nel punto di fermata, che e dedica­ to essenzialmente all'esame del loro aspetto morfologico) , questa appare di natura ero­ s ionale : essa tronca, in quest'area, la parte alta del complesso superiors della successione-tipo del villa­ franchiano. questa superficie e stata modellata per erosio­ n a laterals da parte di un corso d'acqua di portata con­ frontabile con quella del po o del tanaro attuali (ii raggio meandrico di questi fiumi e infatti paragonabile con quel­ i o delle depressioni ad andamento curvilineo). questo corso d'acqua aveva la propria direzione di deflusso verso est , come si pub dedurre seguendo l'andamento com­ plessivo di questi relitti morfo­ logici dalla pianura piemontese meridionale verso i rilievi dell' astigiano. i denti di e. primige­ n i us descritti da zuffardi (1913)(2) indicati dall'autore genericamente come prove­ nienti da s. paolo solbrito , sembrano con ogni probabi­ lita provenire, secondo i dati storici reperiti con pazienti ricerche d'archivio, dalla cave aperte in questi depositi per realizzare ii rilevato della fer­ rovia nel tratto tra villanova e villafranca. questa circostanza, unitamente alle indicazioni di carattere pedostratigrafico che si possono ricavare dai limi fluviali, non­ cha dal contesto stratigrafico generals del bacino piemontese meridionale in cui questi si situar-10, ne indicano in maniera sufficiente­ mente affidabile l'eta tardo-pleistocenica superiors (60.000 +40.000 anni b.p.). ii collettore del bacino piemontese meridionale lino appunto verso la fine del pleistocene superiors defluiva a sud dei ril ievi della collina di torino, lungo l'asse dell 'attuale altopiano di poirino. in un certo momento durante questo intervallo di tempo, per la combina­ zione di una serie di fenomeni di natura geodinamica con altri di origins esogena (cir. § 4.2. della monografia illustrativa della revisio­ ne), questo collettore ha sublto un fenomeno di diversions: ii corso d'acqua cui fa capo ii deflusso del bacino piemontese meridionale ha cos] assunto l'attuale decorso a nord dei rilievi collinari (quello del fiume po tra moncalieri e valenza po). nell'area in cui era (2) zuffardi p. (1913) etefanti fossili de/ piemonte. pal. it. , 19, 121-187. defluito ii collettore del bacino piemontese meridionale si e in seguito impostato ii reticolato idrografico locale del t. sanna. ii disegno di quest'ultimo ha ereditato in molti tratti l'andamento del preesistente , maggiore corso d'acqua: cio e piu facilmente riscontrabile nei trat­ ti che si sviluppano con direzione media n-s, comuni ai due sistemi idrografici caratterizzati pero da un senso di deflusso opposto. ii drenaggio verso ovest del bacino del t. sanna appare conforme con la pendenza nella stessa direzione dell'altopiano di poirino; questa pen­ denza si era peraltro cominciata a delineare fin dai primi episodi di modellamento di questa unita morfologi­ ca, ma ii collettore del bacino piemontese meridionale era riuscito a compensarla con la propria attivita sedi­ mentaria (tratto occidentale) o erosiva (tratto orientale) lino al momenta della diversione. risaliti sul pullman, si percorrono poche centinaia di metri fino a che, all 'inizio dell 'abitato di valfenera, si apre improvvisamente ii paesaggio collinare dell' astigiano: ii limite tra altopiano di poirino e rilievi dell'astigiano e segnato da una scarpata alta in media 80 metri; questa ha un andamento in pianta che, se pure molto articolato nel dettaglio, appare complessiva­ mente rettilineo e diretto n-s nel suo tratto settentriona­ le per poi piegare verso sw in quello meridionale (cfr. fig. 2). la situazione del tutto particolare che si riscon­ tra in corrispondenza a questa scarpata, situazione che non era sfuggita agli autori del secolo scorso, e che ii paesaggio collinare che si incontra ad est di questa si sviluppa a quote piu basse del prolungamento ideale nella stessa direzione dell' altopiano stesso; solo le sommita piu elevate mostrano quote talora leggermente superiori. tale circostanza aveva fatto parlare gastaldi ed altri autori suoi contemporanei di "rilievi modellati in negativo", come se si trattasse di un caso particolare e come se tutti i rilievi che esprimono l'espressione morfologica di un orogeno non lo fossero; ma di un caso particolare si tratta in effetti. la scarpata che costituisce ii margine orientals dell'altopiano di poirino rappresenta l'espressione morfologica della zona di ..... i \ i 4 pleistocene 1 b superion, , , pleistocene i ' medio .. plci1toccnc • mcdio-1up. 659 orio di t plci1~cn• __...scup■. ta iiijic'i""' oloc:enc -%-%sinclinalc fig. 4 le tracce dell'idrografia a meandri, conservata sull'altopiano di poirino [da forno (1981) in bartolini (1992)] . evidence of the winding path of water courses on the poirino plateau [see forno (1981) in bartolini (1992)]. deformazione del t. traversola, importante fascia di strutture a vivace attivita recente di natura traspressiva destra: i due paesaggi profondamente diversi che si riconoscono ai due lati di questa struttura testimoniano ii tipo di evoluzione completamente differente intercorsa in epoca recente (post-tardo pleistocenica superiore) nei settori posti ad ovest e ad est della stessa. ii settore occiden­ tals {altopiano di poirino) e stato sostanzialmente stabile subendo un leggero basculaggio verso ovest; quello orientals (rilievi dell 'astigiano), pure tiltato verso ovest, e stato inoltre sede di un leggero sollevamento differenziale subendo una veloce e consistente traslazione verso sud. percorsi alcuni chilometri in direzione se, si scende sul fondo della valle stanavasso. ii fianco sinistro di questa incisione (che drena verso nord) e impostato nel fascia di strutture che costituiscono la zona di deformazione del t. traversola: le formazio­ ni in cui e incisa appartengono sia al complesso inferiors che a quello superiors. ii versante destro e invece modellato nella intera successione indisturbata. avvicinandosi all'abitato di ferrere, in relazione alla inclinazione verso nw della successione, ii rilievo comincia ad essere modellato esclusivamente nel complesso lnferiore. estesi affioramenti nelle sabbie dell 'unita di ferrere sono riconoscibili, soprattutto in sinistra della strada, subito dopa aver oltrepassato ii centro di ferrera, alla testata della valle maggiore. 660 maretto .· · . -~-~ccessione marina pr~vlllafr~n~hla~a ... .. :.--·-· .. -·-· .... -. . stop 2: cascina mottura (5 km a sud di villafranca d'asti, in comune di ferrera) l'affioramento e situato sul versante sinistro della valle maggiore, 200 m a sud di cascina mottura, nella fascia altimetrica compresa tra 220 e 235 m. in prossimita al margine meridionale dell' area-tipo, in corrispondenza al fianco meridionale della sinclinale di asti , e osservabile la base della successione villafranchiana e, in particolare, ii contatto con la sottostante successione marina. alla base dell'affioramento, per uno spesso­ re di circa 1 m, sono osservabili i sedimenti sab­ biosi dell'unita di ronco, corrispondenti alla parte inferiore della formazione indicata in letteratura come "sabbie di asti": questi sono caratterizzati da stratificazione pianoparallela e da resti di numerosi molluschi marini, prevalentemente concentrati in livelli (un elenco delle forme piu diffuse e l'interpretazione del loro significato paleoambientale, paleoclimatico e cronostratigrafico sono riportati nella descrizione dello stop 3): la concentrazione dei resti fossili e accompagnata da una sensibile cementazione carbonatica. al di sopra dei sedimenti descritti, per tutto ii rimanente spessore visibile, di circa 13 m, sono osservabili i sedimenti sabbiosi dell'unita di ferrera, corrispondenti al termine inferiore della successione villafranchiana. questi sedimenti presentano una stratifica­ zione incrociata concava a grande scala, sottolineata da evidenti superfici di erosione con andamento pure concave: i sedimenti sab­ biosi che ne costituiscono ii riempimento contengono alla base sande mud clasts arrotondati connessi alla rielaborazione di livelli arenacei o siltosi, con diametro da centimetrico fino a decimetrico, e presentano una tessitura progressivamente piu fine verso l'alto; al tetto localmente si osservano lenti di sedimenti siltosi. le strutture sedimentarie risultano sottolineate da concentrazioni di ossidi di ferro e di manganese. si osservi come i sedimenti dell'unita di ferrera siano caratterizzati da grado di addensamento apprezzabile, evidenziato anche dalla sostanzialmente buona conservativita delle scarpate naturali e artificiali modellate in questa unita: questo aspetto andra ricordato quando si effettuera lo stop 8 dedicato all'osservazione delle sabbie dell'unita di cascina gherba, del complesso superiore, che risulteranno visibilmente molto meno addensate. risaliti in pullman si percorre in direzione ne la strada comunale che segue la base del versante sinistro della valle maggiore, modellato nel complesso lnferiore: i termini del complesso superiore costituiscono solo le dorsali sommitali. al bivio situato circa 1 km a monte di villafranca si prende a destra la strada per cantarana e si attraversa ii largo fondovalle della valle maggiore. raggiunto l'abitato di cantarana, lo si lascia sulla destra, e si percorrono alcune centinaia di metri lino a raggiungere lo stop 3. dee~!!~~~ t~~l_postvlllafranchlanl stop 3 : arboschio (2 km a se di villafranca d'asti, in comune di cantarana (3) (4)) l'affioramento e situato lungo ii versante destro della valle maggiore, 200 m a sud dell'abi­ tato di arbbschio, nella fascia altimetrica compre­ sa tra 170 e 210 m. corrisponde attualmente ad una successione di fronti di cava sovrapposti con estensione complessiva in altezza di circa 40 m. in questo settore sviluppato al margine orientale dell'area-tipo, in relazione all'inclinazione verso ovest dell'asse della sinclinale, affiora la parte inferiore della successione villafranchiana. la cava coltiva ii tratto inferiore della successione descritta da pavia (1970) (5): litozona 1) e da ghibaudo in carraro et al. (1982)(6) . maretto . · · .--..:_-~ccessione marina previllafran~hlana . . . . . . . . . . . . ··:-.. -· {3) la soprintendenza archeologica del piemonte ha fatto eseguire un progetto di ripristino ambientale della cava per realizzare un parco paleontologico. (4) in genera ii limite inferiors dei fronti di cava coincide con ii limite tra le sabbie marine dell'unita di ronco e quelle deltizie dell'unita di ferrere: eviden­ temente le prime, caratterizzate da un notevole contenuto di molluschi marini, sono meno adatte come inerti in confronto alle seconde che invece si pre­ stano molto bene all 'utilizzo industriale. (5) pavia g. {1970) resti di anancus arvemensis e flora ad affinita pfiocenica nel villafranchiano inferiore def/a cava di arboschio. mem. soc. geol. it. , 9, 157-176. {6) carraro f., forno m.g. & valpreda e. (1982) field trip in northern italy guideblok: september 15th-piedmont: asti area. "i.g.c.p. 73/1/24", quaternary glaciations in the northern hemisphere, final session, september 1-17 th. , 1982, france italy, 19-25, lit. m. & s., torino. 661 alla base dell 'affioramento, quando non ancora coperta dai prodotti colluviali, era possibile riconoscere i sedimenti sabbiosi rnarini riccamente fossiliferi dell'unita di ronco (sabbie di asti p. p.). in corrispondenza alla parte inferiore dell'affioramento attuale sono invece riconoscibili i sedimenti sabbiosi dell 'unita di ferrera, osservabili per l'intero spessore pari a circa 18 m. vi si possono riconoscere due litozone: 1) alla base, per 1,5 metri, affiorano sabbie medie di colore grigio vistosamente bioturbate da domicnia (galleria di crostacei dell'icno­ genere ophiomorpha); la struttura risulta omogenea con fantasmi di laminazioni piu o meno oblique. non sono stati rinvenuti fossili; 2) seguono sabbie da medie a grossolane, spesso microghiaiose, organizzate in strutture a festoni con laminazioni oblique ad angoli opposti e variamente aperti . tale litozona costituisce ii corpo in cui e aperto ii fronte di cava e si estende per circa 16 metri di spes­ sore. nel tratto intermedio e superiore sono frequenti le strutture canalizzate con base del canale evidenziata da accumuli spesso caotici di mud c/asts, ciottoli, legni fluitati e fossili di molluschi. nella meta inferiore della litozona i sets di !amine, estesi lateralmente, sono evi­ denziati da concentrazioni di fossili di molluschi, soprattutto bivalvi giustapposti sulle superfici laminari con convessita verso l'alto; nel trat­ to superiore della successione sabbiosa le strutture canalizzate, piu alte, sono invece evidenziate da allineamenti di mud clasts appiattiti e da ciottoletti. la colorazione delle sabbie e tendenzialmente grigiastra, a tratti arrossata o annerita rispettivamente da ossidazioni o da residui di alterazione della sostanza organica. le sabbie contengono ricche associazioni fossili con prevalenti resti di molluschi marini, la cui composizione si impoverisce dal basso verso l'alto pur mantenendosi costante negli elementi tassonomici piu frequenti. alie sabbie si intercalano orizzonti sabbioso-pelitici di colore bruno-grigiastro a laminazione piano-parallela; gli strati pelitici si presentano vagamente ondulati, lenticolari alla scala dell'affioramento ed interrotti lateralmente dalle strutture canalizzate. essi sono attraversati da galleria subverticali, verosimilmente domicnia terebrati a partire dalla superficie superiore dello strato pelitico, dopo la sua deposizione, entro le sabbie sottostanti. localmente le peliti sabbiose contengono fossili di molluschi marini e frequenti addensamenti planari di filliti di fanerogame terrestri , evidentemente fluitate. contenuto paleontologico della litozona 2 le sabbie della litozona 2, soprattutto nel terzo inferiore, sono riccamente fossilifere con associazioni a molluschi di pertinenza marina e solo in parte riconducibili ad ambienti influenzati da apporto di acqua deice. sono state riconosciute complessivamente 105 specie, di cui 46 gasteropodi, 55 bivalvi, 4 scafopodi di seguito elencati secondo la sistematica adottata da cavallo & repetto (1 992)(7); i bivalvi dominano come numero di esemplari. i gusci sono fortemente decalcificati e molto spesso i fossili si sbriciolano durante ii campionamento; e quindi possibile che la composizione dell'orictocenosi possa essere incrementata con la raccolta in settori di sedimento meno sottoposti a sottrazione di carbonate ad opera delle acque percolanti. la raccolta, effettuata manualmente, e di tipo semiquantitative ed integra i dati gia riportati in letteratura (pavia, 1970) ; i valori di abbondanza delle singole specie sono espressi con: raro (r) = 1 +2 esemplari; comune (c) = 3+7 esemplari; frequente (f) = 8+20 esemplari; frequentissimo (ff)=> 20 esemplari. gastropoda c diodora italica r gibbula magus r diloma patulum r tricolia pullus r bo/ma rugosa f cerithium crenatum c potamides tricinctus c turritella vermicu/aris r aporrhais pespelecani f calyptraea chinensis c crepidula gibbosa r crepidu/a unguiformis c petaloc. glomeratus c natica tigrina i neverita josephinia c sinum striatum r ma/ea orbiculata r epitonium commune c botinus torutarius r heraptex tapparonii r ocenebra erinacea r ocinebrina scalaris c heterop. polymorpha r hadriania oretea i cyctope neritea r nassarius serraticosta r nassarius mayeri f nassarius gibbosu/us i nassarius mutabilis c nassarius lima r mitre/la scripta r mitra minor c cancel/aria cancellata r salafia hirta r ganus mercatii r ganus pyruta r ganus striatulus c hastuta costulata c strioterebrum reticulare f subu/a fuscata r terebra acuminata r basisu/cata simplex r turbonilla jactea r acteon semistriatus c ringicula auriculata r ovate/la myotis scaphopoda c dentalium sexangu/um r antatis inaequicostata c antalis fossilis f antalis vu/garis 8/valvia f nucuta nucleus c -arca noae r anadara pectinata f glycymeris insubrica ff modiolus adriaticus r pecten jacobaeus r aequipecten scabrel/a c chlamys multistriata c lima exilis f ostrea forskalii f lucine/la divaricata f diplodonta rotundata c chama placentina c cardites antiquatus c acanthocardia spinosa f cerastoderma edule c mactra glauca r lutraria lutraria c te/jina compressa c tellina planata r gastrana fragilis ff donax minutus r pharus jegumen ff chamelea gallina f dosinia jupinus f callista puella r paphia vetula genei r panopea glycimeris r nuculana pella c barbatia mytiloides c glycymeris bimaculata r mytilus scaphoides r atrina pectinata ff pecten flabelliformis f ch/amys inaequicostalis c lissochlamys excisa f ostrea edulis f loripes lacteus f diplodonta apicalis f chama gryphoides f glans intermedia f acanthocardia acu/eata f laevicardium crassum ff cerastoderma c/odiense f spisu/a subtruncata r donacil/a cornea c tellina nitida r macoma cumana c gastrana /etcunosa c abra prismatica c v. foliaceolamellosa r timoclea ovata c callista chione c pelecyora gigas c corbula gibba ( 7 ) cavallo 0. & repetto g. (1992) "conchiglie fossili def roero: atlante iconografico". ass. natur. piemont., mem. 2, 249 pp. 662 nel loro complesso le sabbie della litozona 2 presentano associazioni a molluschi fossili del tutto corrispondenti a quelle degli affioramenti tipici della formazione delle sabbie di asti. ii 98% delle specie elencate ad arboschio e infatti presente nel cosiddetto "strato a glycymeris" di valleandona e baldichieri; detta percentuale di somiglianza specifica aumenta al 100% se paragonata con l'associazione a molluschi dello "strato a jsognomon" (pavia, dati personali}, orizzonte fossilifero ubicato nella parte media delle "sabbie di asti" alla sommita della sezione del castello di valleandona (sampo et al., 1968(8)). fa eccezione la frequenza di c. glau­ cum clodiense, bivalve riconducibile ad ambienti sedimentari influenzati da apporto di acqua dolce, se non salmastri. nella litozona 2 si hanno due livelli tabulari (rispettivamente 3 e 10 m sopra la base della sezione) composti da numerosi strate­ relli pelitici (1 +5 cm) con intercalazioni sabbiose planari all'incirca del medesimo spessore. nel livello inferiore prevalgono impronte di resti fogliari altamente frammentati, su alcuni dei quali e stata notata la presenza di briozoi. due straterelli pelitici (ab10 e ab12) del livello superiore (10,0+ 10,8 m) sono invece ricchi di impronte di foglie perfettamente integre o solo scarsamente frammentate. queste si rinvengono anche in grossi blocchi di peliti (ab13) incluse nel livello sabbioso soprastante (10 ,8+15 m ca.) . di seguito sono elencati i taxa identificati e la loro frequenza: ab10 ab12 ab13 acer tricuspidatum a/nus cecropiaefolia a/nus gaudinii "bambusa" cf. astensis betula sp. celtissp. daphnogene po/ymorpha r dicotylophyllum sp. fagussp. ocotea heeri platanus sp. popu/ussp. populus cf. tremula pterocarya sp. sa/ixsp. ulmussp. considerazioni tafonomiche sulle associazioni a molluschi ff rr rr rr rr rr r 1 f r r ff rr rr rr ? ff rr rr ff dal punto di vista fossildiagenetico, i gusci di molluschi mostrano uguale stato di conservazione ed i fossili, seppur decalcificati, non presentano differenze che possano essere ricondotte a diversi episodi diagenetici. la decalcificazione interessa prevalentemente i gusci aragonitici (la maggior parte dei gasteropodi, molti bivalvi e tutti gli scafopodi}, mentre sono meno alterati i gusci originariamente calcitici dei gasteropodi epitoniidae e dei bivalvi pectinidae ed ostreidae, che si raccolgono con relativa facilita anche nel detrito di cava. l'analisi biostratinomica indica una pervasiva e costante alloctonia dei fossili, con elementi tafonomici prodotti in altri luoghi e tra­ sferiti (risedimentati) da correnti sul fondale di sedimentazione. ne sono indizi: (1) la frequente usura dei gusci dei molluschi con trac­ ce di frattura da urto, abrase per attrito con i grani sabbiosi; (2) la costante disarticolazione dei gusci di bivalvi; (3) la riorientazione delle valve con convessita verso l'alto e la loro disposizione sulla superficie delle lamina oblique; (4) la disposizione caotica dei fossili al fondo delle strutture canalizzate in assenza di bioturbazione. lo stato di conservazione dei fossili non frammentati permette di escludere fenomeni di rimaneggiamento (rielaborazione sensu fernandez lopez, 1991 ), ipoteticamente compatibili con la forte energia idrodinamica di un siffatto ambiente sedimentario comportan­ te erosione di sedimenti precedentemente deposti ed esumazione di strutture scheletali gia sepolte (fossili). chiare indicazioni in tal senso si ricavano sia dall'omogeneita fossildiagenetica sia dalla sporadica presenza di gusci di gasteropodi non colmati da sedimento sia ancora da deformazione clastica dei gusci per carico sedimentario. e' ii caso dei fossili presenti !n un lembo pelitico-sabbioso preservato nel terzo inferiore della successione, in cui sono stati rinvenuti esemplari di n. josephinia e n. mutabilis in notevole stato di freschezza, rotti per trasporto e deformati per compattazione, ma non usurati; a questi gasteropodi era associato un esemplare di d. lupinus ii cui guscio a valve articolate esclude ogni rielaborazione. eventuali casi di rielaborazione su fossili appartenenti a fasi di sedimentazione (e di diagenesi) precedenti potrebbero essere ipotizzati per i frequenti gusci fratturati ed usurati, ma in nessun caso risultano evidenze significative; tali fossili sono tafonomicamente indefinibili. le orictocenosi presenti nei successivi orizzonti fossiliferi della litozona sabbiosa 2 sono quindi da considerare omogenee dal punto di vista tafonomico e possono essere utilizzate nel loro complesso per considerazioni sia cronostratigrafiche sia paleoambientali. (8) sampo' m., zappi l. & caretto p.g. (1968) "les foraminiferes de /'astien •. giorn. geol., 35 (1967) , 277-293. 663 lnquadramento cronostratigrafico le associazioni fossili della litozona 2 di arboschio non forniscono dati biostratigrafici "tradizionali" utili per un diretto inquadra­ rnento cronostratigrafico dei relativi sedimenti sabbiosi. tuttavia alcune specie di molluschi sono significative a questo riguardo. l'insieme dei molluschi, sebbene con un basso grado di estinzione rispetto alle malacofaune attuali (29%), contiene alcune spe­ cie a distribuzione mio-pliocenica oppure esclusive del pliocene (13%). tra queste ultime, l. excisa e p. gigas, presenti ad arboschio con esemplari integri, non rielaborati, sono ricordate da marasti & ratti (1976(9)) e da ratti & marasti (1982)(10) come forme estinte alla base del piacenziano (pliocene medio) prima del raffreddamento climatico datato 3,2+3,0 ma. dal punto di vista cronostratigrafi­ co, le sabbie della litozona 2 di arboschio sono quindi riferibili al limite zancleano-piacenziano o piu verosimilmente al piacenziano inferiore sensu rio et al. (in stampa)(11 ). considerazioni paleoecologiche l'analisi paleoecologica e stata condotta con riferimento sia alla ricca bibliografia esistente sull'argomento (cf. ferrero & merlino, 1992 (12); campantico, 1993) sia agli studi sulle comunita bentoniche attuali del mediterraneo (peres & picard, 1964 (13); picard, 1955(14)). le associazioni a molluschi della litozona 2, pur impoverite tassonomicamente dal basso verso l'alto della successione litostrati­ grafica, si possono considerare omogenee dal punto di vista del significato paleoambientale. esse sono classificabili come "orictoce­ nosi alloctone indigene", in quanto costituite da resti conchigliari prodotti da biota viventi in ambienti contigui dei piani infralitorale e litorale . dal punto di vista qualitative, quasi ii 50% dei molluschi elencati popolava infatti i fondali piu superficiali del mare astigiano, rnentre la restante percentuale di specie riguarda forme euribate diffuse a diversi livelli biocenotici della piattaforma continentale. la pertinenza infralitorale e litorale raggiunge pero valori prossimi al 100% nel compute limitato alle specie f o ff. ii dato batimetrico e in accordo con l'affinita tessiturale propria dei taxa determinati. alcuni molluschi, riportati in letteratura come indicatori di substrati solidi, nel contesto della forrnazione delle sabbie di asti sono da ricondurre a fondali sabbiosi con abbondanti conchiglie, o eventualmente ricchi di ciottoli ghiaiosi, funzionanti da ancoraggio di bivalvi bissati o di molluschi cementanti (es. 0. edu­ lis, 0. forskali1) . altre forme risultano invece adattabili a fondali misti , sabbioso-pelitici, e tra queste ii mistofilo m. adriaticus. la mag­ gior parte dei molluschi enumera invece specie viventi su o entro fondali sabbiosi; si tratta di forme psammofile pure o tolleranti che comprendono quasi tutte le forme classificate f o ff, tra cui merita ricordare c. clodiense, d. minutus, c. gallina. fanno eccezione le specie pelofile tolleranti c. crenatum, d. rotundata, c. edule, adattate anche a fondali fangosi di ambiente lagunare, e n. josephinia forma euritopa della parte superiore della piattaforma continentale . dal punto di vista paleobiocenotico, tutte le specie di molluschi sono riconducibili a paleocomunita dei livelli superiori del piano infralitorale o, in minor misura, del piano litorale, direttamente in quanto esclusive (e) o preferenziali (p), oppure indirettamente in quanto accompagnatrici delle biocenosi marine superficiali elencate da peres & picard (1964), picard (1965) e corselli & scola (1990)(15). le considerazioni che seguono sono !imitate alla specie classificate ad arboschio come f o ff, trascurando quelle ii cui significato bio­ cenotico e nullo o imprecisato. la maggior parte di queste specie e riferibile alla biocenosi attuale delle "sabbie fini ben calibrate" (sfsc). tra le specie piu signi­ ficative si ricordano: n. josephinia (e), n. mutabilis (e), s. fuscata (p), b. mytiloides (p), g. insubrica (p), c. inaequicostalis (e), g. inter­ media (p), a aculeata (e), c. gal/ina (p), d. lupinus (p), c. puella (e) . la biocenosi sfbc si sviluppa su fondali con sabbie fini a granulometria omogenea, talvolta leggermente fangose; gli organismi bentonici, tra i quali i bivalvi costituiscono la componente mala­ cologica dominante, sono in grado di tollerare un'eventuale diminuzione di salinita, rispondendo alle variazioni del parametro chirnico con un impoverimento in specie caratteristiche bilanciato da un aumento dei taxa accompagnatori eurialini. specie accompagnatrici della biocenosi sfbc sono da considerare c. gryphoides (caratteristico del posidonieto), n. nucleus (diffusa nei livelli al passaggio con ii circalitorale, al di fuori della costante energia idrodinamica propria dell'infralitorale), c. chinensis, d. apicalis, l. crassum, a. vulgaris (carattersitici di fondali a sabbie grossolane sottoposti a correnti di fondo). [le specie classificate c sbilanciano ancor di piu in senso sfbc tali considerazioni paleobiocenotiche]. altre specie di molluschi sono ritenute significative della biocenosi delle "sabbie fini dei livelli superficiali" sviluppata lungo la linea (9) marasti r. & ratti s. (1976) "osservazioni biostratigrafiche e paleoecologiche sul/a malacofauna def piacenziano di maiatico (parma, emilia occi­ denta/e)". boll. soc. paleont. it., 15, 189-214. (10) ratti s. & marasti r. (1982) 'the mediterranean bioprovince from the pliocene to the recent: observations and hypoteses based on the evolution of the taxonomic diversity of molluscs". proc. 1st intern. meet. "paleontology, essential of historical geology", venezia, 151-177. (11) rio d., sprovieri r. & di stefano e. (in stampa) 'the gelian stage: a new chronostratigraphic unit of the pliocene series". riv. it. paleont. (12) ferrero e. & mertine b. (1992) "ricostruzione paleoecologica di una malacofauna def bacino pliocenico astigiano {italia nw)". boll. malacol., 28, 101-138. (13) peres j.m. & picard j. (1964) "nouveau manuel de bionomie benthique de ta mer mediterranee•. rec. trav. st. mar. endoume, 31 , 137 pp. (14) picard j. (1965) "recherches qualitatives sur /es biocenoses marines des substrats meubles dragables de la region marsei/laise•. rec. trav. st. mar. endoume, 36, 160 pp. (15) corselli c. & scola d. (1990) "biocenoses and thanatocenoses in sfb_g bottom•. atti v simp. "ecologia e paleoecologia delle comunita bentoniche", mus. reg. sc. nat. torino, 643-658. 664 di battigia in area di shoreface (sfhn: ferrero & merlino, 1992): n. gibbosu/us e, soprattutto, la ff d. minutus. sano frequenti inoltre i molluschi che, pur segnalati diffusamente in sfbc e sfhn, sono in grado di sopportare variazioni di salinita; la loro abbondanza e un chiaro indizio di condizioni almeno parzialmente influenzate da apporto dulcicolo: c. crenatum, c. neritea, m. adriaticus, l. divaricata, d. rotundata, c. edule, s. subtruncata. a queste si aggiunge c. c/odiense, classificato ff ad arboschio ed indicato come forma esclusi­ va della biocenosi delle "lagune eurialine ed euriterme" (lee: picard, 1965). lnfine l. lacteus e esclusivo della biocenosi delle "sabbie fangose superficiali in ambients protetto" (svcm). considerazioni diverse riguardano p. flabelliformis, bivalve fossils ritenuto significativo dei fondali pelitico-sabbiosi al passag­ gio ira i piani infrae circalitorale ma anche segnalato autoctono nelle orictocenosi infralitorali delle sabbie di asti. tenendo presenti le dimensioni generalmente ridotte dei resti di tale pettinide e la prevalenza di valve sx piatte rispetto a quelle dx convesse, la fre­ quenza di p. flabelliformis pub essere spiegata con un trasporto selettivo ad opera di correnti di fondo in grade di trasferire strutture ad elevata portanza idrodinamica. in conclusions, le orictocenosi alloctone a molluschi della litozona 2 risultano composts da differenti stocks paleobiocenotici importati dai settori piu superficiali del piano infralitorale e da quelli al passaggio con ii litorale. la maggior parte dei molluschi fossili campionati ad arboschio comprende infatti specie proprie di paleobiocenosi sfbc (es. c. gallina), a cui si associano larghe percentuali di forme riconducibili a biotopi sfhn0rd (0. minutus) e lee (c. c/odiense). circa ii tipo di corrente a cui imputare tale concentrazione biostratinomica, la coesistenza di numerosi molluschi tipicamente marini con specie in grado di sopportare una diminuzione di salinita per apporto dulcicolo, se non addirittura caratteristiche di lagune eurialine, trova spiegazione nel gia descritto controllo delle correnti di marea (ghibaudo in carrara et al. , 1982) sulla deposizione delle sabbie a carpi canalizzati con strutture a festoni e lamina oblique, alternali ad episodi di decantazione degli orizzonli sabbioso-pelitici con filliti. nella parte superiors dell'attuale cava, per uno spessore di circa 3 m, sono osservabili i sedimenti limoso-sabbiosi dell'unita di s. martino. questi risultano costituiti da alternanze a scala metrica di silt, caratterizzati da laminazione pianoparallela, e da sabbie fini, che presentano invece laminazione incrociata planare. in prossimita del limite fra le due unita e riconoscibile un livello con spessore decimetrico legato ad una sensibile cementazione carbonatica. al di sopra dell'affioramento esposto nella cava attiva si sviluppa un fronte di cava superiore, non piu attiva, in corrispondenza al quale e osservabile, per lo spessore complessivo di circa 15 m, parte dell'unita di s. martino. essa e in particolare costituita alla base da alternanze a scala decimetrica di sedimenti siltosi e di sedimenti sabbiosi fini; nella parte alta prevalgono invece i sedimenti siltosi , ricchi di impronte di foglie e di frustoli vegetali con locali concentrazioni di molluschi continentali. all'interno di due intercalazioni sab­ biose riferibili all'unita di s. martino, pavia (1970) segnala ii rinvenimento dei resti di anancus arvemensis e di rhinoceros sp.(16). al tetto dell'affioramento, intercalato nell'unita di s. martino, e riconoscibile un livelletto sabbioso di pochi centimetri di spessore con una fauna a lamellibranchi e foraminiferi di ambients salmastro (pavia, 1970), fatto che sottolinea l'esistenza di locali rapporti di interdigitazione fra le due unita del complesso inferiore: unita di s. martino e unita di ferrera. considerazioni sui macrofossili vegetali in diversi livelli della cava sono conservate impronte di resti vegetali terrestri , che rappresentano sia associazioni alloctone (unita di ferrera e alcuni livelli dell'unita di s. martino) sia autoctone/ipoautoctone (unita di s. martino). le impronte di foglie (filliti) rappre­ sentano certamente ii materiale da cui si possono trarre le maggiori informazioni. ii piu ingente contribute alla raccolta e allo studio di filliti in questa successione e dovuto a pavia (1970). durante ii recente lavoro di revisione del villafranchiano si sono effettuate raccol­ te molto piu !imitate, le quali hanno, tuttavia, messo in luce degli insiemi floristici del tutto analoghi a quelli evidenziati in precedenza, fatta salva la necessita di una generale revisions tassonomica. le nuove indagini sui macrofossili vegetali nel livello (ab20) ubicato 31 m sopra la base della sezione (sedimenti pelitici al tetto di un paleosuolo poco evolute) hanno evidenziato un'associazione palustre oligolipica con impronte di foglie dei seguenti taxa: a/nus gaudinii ff acer tricuspidatum glyptostrobus europaeus rr monocotiledoni "pteris" sp. taxodium dubium nella parte piu alta della sezione (41 m sopra la base), estate possibile campionare alcune impronte di vegetali in un livello pelitico (ab30): acersp. carpinus sp. frutto frutto {16) originariamente dovevano essere presenti locali forti concentrazioni di resti di vertebrati: negli anni '70 la concentrazione dei resti era cosi rilevante da costringere i cavatori ad accumulare le ossa "in modo da consentire l'utilizzo della sabbia, di per se molto pura". daphnogene polymorpha fagussp. magnolia sp. pinus cf. peuce quercus sapperi ouercus pseudocastanea symplocos schereri toddalia sp. foglie frutto e cupula frutto cono cupule foglie frutti semi 665 tutte le associazioni a macrofossili vegetali della successione della cava arboschio, benche piu o meno ricche, indicano chiara­ mente delle condizioni climatiche temperate caldo-umide. i dati disponibili per la successione esposta nella cava arbbschio non met­ tono in luce alcuna differenza di rilievo fra le flora fossili dei sedimenti delle unita di ferrera e di s. martino. soprattutto grazie alla ricca documentazione raccolta da pavia (1970), si pub ricostruire una vegetazione arborea prevalentemente caducifoglia con molti generi ancora viventi in europa, attiancati a non pochi elementi "esotici". risulta chiaro che ii record paleotloristico e fortemente sbilan­ ciato a favore di elementi rivieraschi (a/nus, popu/us, platanus, pterocarya, salix, u/mus), caratteristica tipica di associazioni a macro­ resti condizionate da un trasporto fluviale. notevole la costante presenza di alcune forme sempreverdi termolile che giocano a favore di un clima leggermente piu caldo dell'attuale. un trend di raffreddamento verso l'alto (proposto da pavia, 1970) non e documentabile con le macroflore se si tiene conto del recente rinvenimento, nella parte piu alta della sezione di arboschio (ab30), di numerosi taxa termofili "terziari", come daphnogene polymorpha, quercus sapperi, quercus pseudocastanea, symplocos schereri, toddalia sp. dal punto di vista biostratigrafico le !lore di arbbschio mostrano spiccate affinita neogeniche. si tenga perb conto che in italia centrale associazioni a foglie e legni ad affinita neogenica sono segnalate in un deposito datato radiomentricamente a 700.000 anni (follieri, 1984(17)) . ciononostante , l'associazione paleocarpologica del livello ab30, con symplocos schereri e toddalia sp., non pub essere posteriore al piacenziano. caratteristiche sedimentologiche della successione dei quattro fronti di cava descritti da pavia (1970) solo ii piu basso, ancora attivo, permette una visione completa e dettaglia­ ta delle litofacies; negli altri tre detrito superficiale e vegetazione nascondono gran parte dei fronti di scavo ed impediscono una corretta visione dei depositi. la successione sedimentaria affiora, per circa 44 m, senza evidenti discontinuita stratigraliche, ma solo per i primi 22+23 m si hanno buone condizioni di affioramento. nell'insieme la successione pub essere suddivisa in due parti: una parte inferiore (da q. 0 a q. 17,70 m) dominata da litofacies sabbiose e da resti di malacofauna marina (litozone 1 e 2); una parte superiore (da q. 17,70 a q. 44 m) costituita da alternanze di corpi sabbiosi con limi argillosi. parte inferiore de/la successione di arboschio unita di ferrere (uf) questa porzione e completamente affiorante in corrispondenza del fronte di cava piu basso, unico attualmente attivo. si osserva­ no litofacies organizzate secondo sequenze deposizionali, spesse da 70 cm a 3,5 m, con diminuzione della granulometria verso l'alto (fining upward sequences) . ciascuna sequenza e limitata da superfici erosive alla base ed alla sommita ed e costituita da tre litofa­ cies: a, b e c. canali di marea litofacies a la superficie erosiva e continua, piuttosto irregolare e caratterizzata da tasche erosive profonde lino ad 1 m; per estensioni late­ rali di circa 30 m, sembra avere una disposizione subparallela ai piani di stratilicazione. subito al di sopra della superficie erosiva affio­ rano sabbie grossolane o molto grossolane, contenenti clasti di argilla (mud clasts) e, piu raramente, ciottoli silicei subarrotondati o subangolosi; i clasti di argilla derivano dalla erosione di argille siltose laminate affioranti nella parte alta di questa sequenza sedimen­ taria (litofacies c), oppure a paleosuoli non affioranti in questa parte della successione. la sequenza continua con sabbie media o medio-grossolane, organizzate in stratificazioni incrociate con9ave di altezza compresa ira 15 e 60 cm, le cui dimensioni gradatamente diminuiscono verso l'alto. lamina o sottili strati di limi argillosi si osservano alla base delle stratilicazioni incrociate concave op pure coprono i foreset sabbiosi. i versi de lie paleocorrenti mostrano una spiccata bimodalita. le sabbie lino a q. 1 0 m contengono, con percentuali variabili dallo 0 al 60%, resti di molluschi marini, esclusivamente in fram­ menti molto usurati; resti di tronchi sono invece conservati per tutta la successione. piana tidale esterna litofacies b in continuita di sedimentazione, sabbie fini si sovrappongono alle sabbie con stratilicazioni incrociate. le sabbie mostrano lami­ nazioni incrociate non piu alte di 2 cm con lamina immergenti in direzioni opposte; la loro forma esterna (form set) simmetrica permette di interpretarle come legate, almeno in parte, al moto ondoso. sottili pellicole di limo o sabbia molto fine, concave verso l'alto, coprono (17) follieri m. (1984) 'the history of the climate and vegetation in italy based on palynological and macrofossil record". webbia, 38, 441-453. 666 queste increspature simmetriche producendo strutture del tipo stratificazione-f/asersemplice. spesso le strutture sedimentarie sono mascherate da una intensa bioturbazione che ha lasciato galleria a sviluppo verticale , interpretabili come callianassa. piana tidale interna litofacies c la parte alta della sequenza e costituita da sottili alternanze di limi argillosi con sabbie fini o molto fini. questa litofacies si segue lateralmente per tutta la cava per una estensione superiore a 30+40 m. gli strati sabbiosi sono costituiti da lenti piano convesse, di forma debolmente asimmetrica o simmetrica; internamente sono for­ mati da laminazioni con verso di migrazione bipolare. a volte le sabbie contengono anche detrito conchigliare. i limi argillosi mostrano !amine piano parallele continue lateralmente e contengono resti vegetali (foglie) ed animali (bivalvi), tra cui relativamente frequente e cerastoderma sp., conservato con entrambe le valve e a volte in posizione di vita. i depositi fini sono spesso attraversati da galleria di bioturbazione verticali, larghe tra 2 e 10 mm, mostranti forma ad u e riempimento disposto a menisco. nella parte basale della cava arboschio si osservano sette sequenze, ma solo due mostrano una successione completa delle litofacies a, b e c; nelle altre quattro la porzione superiore della sequenza non conserva la litofacies c. tale aspetto sembra essere legato a fenomeni erosivi piu che non deposizionali. la sequenza di litofacies a, b e c o a e b e stata interpretata come formata in ambiente marino costiero, dominato da correnti di marea. la litofacies a testimonia l'attivita di correnti che avevano la capacita di erodere un fondo argillo-limoso o sabbioso e di trasporta­ re e depositare sabbia medio-grossolana tramite dune subacque alte fino a 1,2 m. le direzioni delle paleocorrenti indicano una marca­ ta bimodalita con valori, in uno stesso strato, anche bipolari. le condizioni energetiche ambientali dovevano essere anche caratterizzate da momenti di stasi, che permettevano la deposizione di drappi di fango argilloso sui foreset e alla base delle stratifica­ zioni incrociate concave. tali aspetti testimoniano flussi con alternanza di energia e con direzioni di scorrimento opposte o differenti, che possono essere messi in relazione a correnti tidali. la presenza di frammenti di molluschi marini e tronchi sarebbe un ulteriore elemento che testimonierebbe l'azione di due flussi con direzione verso terra e verso mare. su grandi distanze (almeno 200 m) le superfici erosive alla base della litofacies a mostrano una geometria spiccatamente concava verso !'alto. per tale ragione i depositi sabbiosi sovrastanti possono essere interpretati come prodotti di forrne canalizzate in ambiente tidale. le litofacies b e c si sono depositate nella fascia intertidale non solcata da canali. correnti di energia piu debole, ma ancora con versi di scorrimento bimodali alternati a momenti di energia nulla, sono qui testimoniate da laminazioni incrociate con foresetdiret­ ti in senso opposto e strutture di tipo flaser. in tali .ambienti l'azione delle deboli correnti tidali interagiva con ii moto ondoso che rielabo­ rava la parte sommitale delle increspature da corrente (current ripples) prodotte dalla marea e ne produceva una forma esterna (form set) simmetrica. secondo le caratteristiche granulometriche e le strutture sedimentarie la litofacies b pub rappresentare la parte piu distale (verso mare) della piana intertidale, mentre la litofacies c rappresenterebbe la porzione piu prossimale (verso terra) dove le condizioni energetiche erano ancora piu basse ed era possibile la deposizione di fango argilloso. la presenza di un ambiente continentale vicino e testimoniata dalla abbondanza di resti vegetali terrestri. sulla base di queste considerazioni ed osservando che i depositi sovrastanti indicano un ambiente deposizionale deltizio, e possibile ipotizzare che la por­ zione inferiore della cava arboschio si sia depositata in un ambiente di estuario. parle superiore de/la successione di arboschio unita di s.martino (usm) scarsi e limitati affioramenti, nascosti tra una fitta vegetazione, costituiscono la porzione superiore della cava arboschio. ii pas­ saggio tra la porzione superiore ed inferiore (q. 17,70 m) e caratterizzato da un profilo di paleosuolo spesso circa 3 m e mostrante un grado di evoluzione medio-alto. questo passaggio costituisce ii contatto tra l'unita di ferrera (uf) e l'unita di s. martino (usm) ed anche ii passaggio tra un ambiente deposizionale marino costiero ed uno francamente continentale. le litofacies piu frequentemente osservabili in questo intervallo sono costituite da grandi corpi sabbiosi o ghiaioso-sabbiosi (lito­ facies d), spessi dai 3 ai 5 m, con base erosiva e mostranti stratificazioni incrociate concave, alte fino a 20 cm; le poche direzioni di paleocorrente (3 valori in tutto) indicano versi di scorrimento dei paleoflussi diametralmente opposti. sulla base dei caratteri sedimentari questi corpi sabbiosi possono essere interpretati come corpi di canale nei quali si risentiva ancora l'effetto delle maree. i depositi grossolani si alternano a sedimenti argilloso-limosi nei quali sono individuabili tre differenti tipi di litofacies (litofacies e, f e g). la litofacies ee costituita da argille limose laminate contenenti un'alta concentrazione di resti vegetali (soprattutto foglie) . la litofacies fe formata da limi con laminazioni piano parallele e continue, alternati a strati sabbiosi lenticolari, spessi fino a 10 cm. questi ultimi sono gradati e mostrano laminazioni pianoparallele alla base ed incrociate nella parte alta oppure sono semplicemente costituite da laminazioni incrociate, spesso rampicanti; la forrna esterna (form set) delle increspature da corrente e sempre conservata. le litofacies e ed f corrispondono a sedimentazione di zone allagate tra i canali distributori di una piana deltizia e sono state prodotte rispettivamente da semplice decantazione di materiale fine o anche da flussi di materiale piu grossolano, tramite deboli correnti di densita. la litofacies g corrisponde a paleosuoli. se ne riconoscono due tipi: uno molto evoluto, con profili spessi piu di 3 m e con strutture pedogenetiche ben sviluppate, ed un secondo poco evoluto, non piu spesso di 70 cm e con spiccate caratteristiche di idromorfia. i diffe­ renti tipi di litofacies g corrispondono a diverse condizioni pedogenetiche: ii primo e interpretato come ii prodotto della pedogenesi in 667 aree per lungo tempo lontane dalla sedimentazione e relativamente ben drenate; ii secondo tipo si e formato in aree imbevute di acqua (condizioni di idromoriia) e frequentemente sommerse dalle acque. in sintesi la parte superiore della successione di arboschio corrisponde alla parte emersa di una zona deltizia con canali distribu­ tori influenzati dall'azione delle correnti tidali (facies d); le aree di intercanale erano in parte sommerse (piccoli stagni litofacies e ed f) ed in parte emerse e sottoposte a pedogenesi (facies g). ripreso ii pullman si prosegue lungo la strada che porta alla s.s. n. 10, fiancheggiando le tracce delle vecchie cave di cantarana. ragg iunta la statale, si prende a sinistra in direzione nw e, dopo alcuni chilometri percorsi sul largo fondovalle del t. triversa, ramo principale del reticolato idrografico locale, si prende ii secondo bivio per villafranca alle cui porte, superato ii cavalcavia sulla ferrovia torino-genova, si lascia ii pullman. dopo un percorso a piedi di alcune centinaia di metri in direzione ovest, dapprima lungo la ferrovia e successivamente all'interno dell'area di cava, ci si porta in posizione panoramica davanti al fronte inferiore della cava r.d.b. deposit! fluvlall terrazzatl postvlllafranchlanl ~-------------~-..-..~~~~~~~ maretto :," ,• · stop4 . · .· .--:__.-~ccess~one_ marina prevlllafran~hlana •-.--.. -· stop 4: cava r. d. b. (in comune di villafranca d'asti, 600 ma nw dell'abitato) l'affioramento e ubicato in corrispondenza al versante destro della valle del t. triversa, 200 m a s dell 'abitato di taverna: i suoi fronti sono attualmente compresi nella fascia altimetrica che si estende tra 175 e 215 m. in corrispondenza al settore centrale dell' area-tipo e quindi all'asse della sinclinale di asti, affiora la parte medio-superiore della successio­ ne villafranchiana: la fascia inferiore dei versanti e modellata nei sedimenti dell'unita di s. martino (complesso lnferiore); la fascia superiore e inve­ ce impostata nei sovrastanti sedimenti dell 'unita di cascina gherba e dell'unita di maretto (complesso superiore). l'affioramento corrisponde alla successione dei fronti di cava sovrapposti della fornace r.d.b., coltivata per produzione di lateri­ zi. complessivamente i diversi fronti si sviluppano per una un'altezza di circa 40 m, costituendo l'affioramento piu esteso dell'intera area-tipo: esso e stato ripetutamente preso in esame da molti auteri sotto ii profile stratigrafico, paleontologico e palinologico. nei diversi fronti sono osservabili i sedimenti dell'unita di s. martino, esposti per uno spessore complessivo di 38 m, corrispon­ dente solo a parte dello spessore conservato per i sedimenti di questa unita. in questo affioramento risulta particolarmente evidente la notevole variabilita di facies di questi sedimenti : sono infatti costituiti da ripetute alternanze, a scala metrica, decimetrica o centimetrica di sedimenti siltosi , siltoso-argillosi e sabbiosi minuti. confrontando le descrizioni delle stratigrafie osservate nei fronti di cava in tempi successivi, dai diversi autori che hanno studiato la successione esposta, si evidenzia l'andamento lenticolare anche in grande delle alternanze di litofacies. i sedimenti siltosi sono caratterizzati prevalentemente da laminazione piano-parallela: piu raramente presentano solo un accen­ no di laminazione o ne sono del tutto privi; localmente mostrano piccoli ripples o strutture convolute legate a fuoriuscita d'acql:la. i sedimenti sabbiosi presentano laminazione incrociata, prevalentemente planare, o sono privi di strutture: talvolta alla base si sviluppa­ no orizzonti carbonatici con spessore da centimetrico a decimetrico, legati a fenomeni secondari. complessivamente i sedimenti sab­ biosi sono di gran lunga subordinati rispetto a quelli siltosi, costituendo intercalazioni con spessore in genere compreso tra alcuni cm e 1 m: solo al tetto del fronte inferiore si sviluppa un corpo sabbioso con spessore di circa 2 m. localmente inoltre si osservano ridotti corpi lenticolari costituiti alla base da sedimenti ghiaiosi. i sedimenti mostrano nel loro insieme un sensibile addensamento, particolarmente rilevante in corrispondenza ai silt privi di lami­ nazione. i sedimenti siltosi contengono localmente, a piu livelli, impronte di foglie , concentrate in corrispondenza ai depositi fittamente laminati, frustoli vegetali, radici e frammenti di rami e tronchi. si osservano inoltre numerosi livelli ricchi di gasteropodi continentali, spesso associati a orizzonti di colore grigio scuro con spessore decimetrico, ricchi di sostanza organica, interpretabili come paleosuoli s./. in corrispondenza alla base del fronte inferiore, prima degli ultimi scavi, si osservava un ceppo fossile in posizione di vita, che conservava parte dell'apparato radicale : ii ceppo, con altezza di circa 60 cm e diametro massimo di circa 80 cm, giaceva in corrispon­ denza a uno strato siltoso ed era sottolineato dall'andamento subverticale della laminazione. nella fascia altimetrica centrale del fronte inferiore (circa 15 m sopra l'attuale base della cava) e riconoscibile un livello di spes668 sore decimetrico ricco di frammenti di tronchi e rami fossili lignitizzati. in corrispondenza al fronte intermedio, per uno spessore di circa 2 m, i sedimenti siltosi sono caratterizzati da una sensibile pedo­ genesi evidenziata dal colore bruno (l'indice di colore medic e 7,5 yr 5/8 nelle notazioni delle munsell soil color charts), dalla presenza di pseudogleys e dalla diffusione delle patine di argilla e delle concrezioni carbonatiche: queste ultime mostrano di avere un andamento a reticolo, in pianta, sottolineando la fessurazione prismatica dei sedimenti. al tetto del fronte superiore si osservano depositi sabbioso-ghiaiosi che costituiscono un corpo lenticolare, separate dai sotto­ stanti sedimenti siltosi da una evidente superficie di erosione irregolare. la matrice, costituita da una mescolanza di sabbia e silt, mostra colore bruno (l'indice di colore media e 7,5 y r 5/6 nelle notazioni delle munsell soil color charts); i ciottoli, caratterizzati da sensibile arrotondamento e modesta sfericita, hanno diametro massimo compreso ira 1 e 3 cm e sono costituiti prevalentemente da quarziti e quarziti conglomeratiche e subordinatamente da gneiss e dolomie. ii modesto addensamento di questi depositi consente di ipotizzare che siano legati alla rielaborazione, ad opera di fenomeni colluviali , dei sedimenti dell'unita di cascina gherba affioranti nella fascia altimetrica immediatamente superiore del versante, dai quali ereditano soprattutto le caratteristiche dei ciottoli. descrizione delle caratteristiche strutturali la successione sedimentaria affiorante presso la cava r.d.b. dal punto di vista strutturale e collocata nel settore assiale della sinclinale di asti, in corrispondenza al quale l'unita di s. martino mostra ii massimo spessore conservato . per quanta riguarda le giaci­ ture locali delle superfici di stratificazione all 'interno di questa unita, valutando quelle che presentano la massima continuita laterale sui fronti di cava, si ricavano valori medi debolmente inclinati (5+6°) verso wsw; si rinvengono pure localmente giaciture "anomale" che localmente sono legate ad irregolarita nelle superfici erosionali minori. lf ~~ '• f1 ~ fo f2 f7 fs e f5 a) b) fig. 5 cava r. d. b., fronte di scavo orientale, settore centrale. strutture deformative entro ai sedimenti limoso-argillosi dell'unita di s. martino. a) faglie inverse (f0, 35°-> 190°; f1 , 25°-> 10°; f3, 25°-> 5°) e normali (f2, 35°-> 190°). le misure del rigetto sul livello ricco di resti vegetali (v) sono in centimetri. le dislocazioni si perdono all ' interno dei soprastanti livelli marnoso-argillosi fittamente laminati {lf). b) faglie inverse (f5 ed f6, 35°-> 170°) e faglie a movimento indeterminato (f7 e fb, 30°-> 25°) che attra­ versano livelli limoso-argillosi a laminazione ondulata e contorta {lc); le dislocazioni sono troncate da una superficie erosionale. r. d. b. quarry, the central portion of the eastern exploitation face. displacement features of silty-clayey deposits of the san martino unit. a): reverse (fo, 35'-> 190'; ft , 25'-> 10'; f3, 25'-> 5') and direct faults (f2, 35'-> 190'). displacement height from the level rich in vegetal matter (vj is in centimetres. displacement evidence disappear within the overlying tightly laminated marl-clay deposits (lf). b) reverse faults (f5 and f6, 35'-170') and faults with undefined kinematic features (fl and fb, 30'-> 25') cutting silty­ clayey layers with undulated and twisted lamination (lc); displacements are truncated by an erosion surface. osservando nel suo complesso la successione affiorante non sono visibili deformazioni che ne attraver­ sino tutto lo spessore. in dettaglio sono invece rilevabili discontinuita strutturali minori. sul fronte orientale della cava, nella parte inferiore della sezione, si rinvengono alcune faglie a basso angolo, alcune delle quali con evidenze di movimento inverse e dislocazioni dell'ordine del centime­ tre; in particolare, nella parte centra­ le di questo fronte di scavo, sono stati misurati dati mesostrutturali in corrispondenza di un settore in cui viene a mancare la continuita latera­ le della laminazione parallela, altrove molto marcata e ben visibile. l'area perturbata e delimitata da faglie che si estendono per qualche metro dalla base dello scavo lino ad attraversa­ re, dislocandolo, un livello ricco in resti vegetali. nella figura sa tale livello e utilizzato come marker per schematizzare le superfici di taglio, la cui direzione media e n100°e. in un livello stratigrafico immediatamente superiore, una decina di metri verso nord, e stata rilevata una situazione analoga, schematizzata in figura sb. altre faglie a basso angolo, con tracce di movimento inverse (dislocazioni e/o trascinamento di lamine pianoparallele) sono state rinvenute, sempre sulla parete orientale della cava, nel settore terminale verso nord (30°➔170° , rigetto apparente di 2 cm; 30°➔205°, rigetto apparente di 0,5 cm, fig. 6) . i sedimenti limoso-argillosi dell'unita di san martino sono talvolta caratterizzati da laminazioni ondulate con ampiezza compresa fra 20 e 60 cm; tali caratteristiche sono particolarmente apprezzabili sulla parete occidentale del gradino creato durante i lavori di scavo sul fronte meridionale. localmente i livelli ondulati sono evidenziati da un colore di alterazione bruno-giallastro, che contrasta con i sottostanti livelli limoso-argillosi non ossidati, di colore grigio-bluastro. la caratteristica significativa dal punto di vista strutturale in questo caso e rappresentata da una sistematica fratturazione subverticale rilevabile entro i livelli inferiori, non alterati, caratterizzati da una fitta laminazione pianoparallela (fig. 7) . le direzioni delle fratture sono, in ordine di frequenza, n100°e, n45°e, n130°e; tali siste­ mi sono spaziati, rispettivamente, 20+40 cm, 50+70 cm, 80+100 cm, definendo talvolta un vero e proprio clivaggio subverticale per fratturazione; localmente si registrano dislocazioni verticali dei blocchi, appena percettibili. al passaggio fra i livelli limoso-argillosi infe­ riori e quelli superiori (con laminazione ondulata) si registra un improwiso e circoscritto aumento della frequenza della fratturazione 669 fig. 6 faglia inversa metrica sulla parete orientale della cava r.d.b., con inclinazione 30°➔ 205° e rigetto apparente di 0,5 cm osservato in corrispon­ denza della fitta laminazione dei limi argillosi dell'unita di s. martino. 3(!'➔ 205° dipping one-metre reverse fault on the eastern wall of the r. d. b. quarry; apparent displacement is 0.5 cm with respect to the tight lamination of the s. martino unit clayey silt deposits. .-.... 1·· ;_ • + -~ • . •-;~~ .) . . ...... ,. :.:· ~_:...;;-;_. {f-che scompare invece quasi del tutto al di sopra di questa fascia, con spessore di una ventina di centimetri. solo alcuni piani si pro­ pagano ulteriormente verso l'alto e tagliano le lamine ondulate in corrispondenza delle creste o delle depressioni. gli elementi deformativi sopra descritti sono stati osser­ vati, con costanza di orientazione e caratteri deformativi lunge lo stesso livello stratigrafi­ co, su tutto ii fronte della cava r.d.b. per una lunghezza di circa 250 metri. non esiste al memento un quadro interpretative chiaro per quanto riguarda le strutture deformative rilevate. le misure rac­ colte (delle quali in fig. 8 e presentato un diagramma riassuntivo) permettono perb alcune considerazioni: 1) tutti i casi di deformazione mostrano fig. 7 sistemi di fratture subverticali (direzioni n100°e, n45°e, n130°e, in ordine di frequenza) nei sedimenti limoso -argillosi non alterati dell'unita di s. martino. nei soprastanti sedime,, : limoso-argillosi, alterati , della stessa unita, la lami­ nazione appare ondulata simmetricamente rispet­ to alle fratture principali. scala: 3,5 mm= 10 cm. subvertical fracturing (stretching n10(j'e, n45°e, n13(j'e, in frequency order) of unweathered silty­ clayey deposits of the san martino unit. lamination in the overlying weathered silty-clayey deposits of the same unit is symmetrically undulated with respect to main fractures. scale: 3.5 mm= 10 cm. 670 i caratteri di surface deformation realizzatasi a stretto contatto con la superficie topografica; la presenza di soprastanti sedimenti indeformati, presumibilmente deposti in tempi immediatamente successivi, permette di classificare tali strutture come intrafolial sedi­ ment deformation (leeder m., 1987(18)); 2) nel primo gruppo di strutture ii quadro geometrico complessivo e gli indicatori cinematici sono compatibili con un campo defor­ mativo locale caratterizzato da compressione lungo la direttrice nne-ssw; cib risulta geometricamente compatibile anche con la disposizione degli altri elementi deformativi rilevati; 3) per ii secondo gruppo di strutture, ii legame geometrico ira le deformazioni fragili (fratture) e le deformazioni "duttili" (ondulazio­ ni nelle !amine) dei sedimenti limoso-argillosi rende plausibile un legame cinematico e dinamico. gli stili diversi appaiono imputabili al diverso grado di consolidamento dei sedimenti e/o ad un effetto differenziale indotto dalla falda idrica locale. in particolare per quanta riguarda i livelli superiori si pub ipotizzare una soft sediment deformation realizzatasi per flusso plastico del materiale non consolidate. nel pomeriggio si riprende la strada statale n. 1 0 in direzione est e, percorse alcune centinaia di metri , si prende a sinistra, sem­ pre sul fondo della v. triversa, seguendo le indicazioni per montafia. al primo bivio, subito dopa aver superato con ii cavalcavia l'autostrada a21 torino-piacenza, si prende a destra e dopo poche decine di metri si lascia ii pullman per accedere allo stop 5. maretto "°gherba ~ . · · .-.....:__-~ccessione marina prevlllafran~hlana . . ..::-·-.. -·. . . . . ___,:___; stop 5: cascina san martino (in comune di villafranca d'asti, circa 1,5 km a nord dell'abitato) l'affioramento corrisponde ad un taglio arti­ ficiale aperto nel versante alle spalle di cascina s. martino; esso e compreso nella fascia altimetri­ ca estesa tra 180 a 195 m. in questo settore, cor­ rispondente alla parte centrale dell'area-tipo, affiora la parte medio-superiore della successio­ ne villafranchiana: lo stop e dedicato in particola­ re all'osservazione della superficie di erosione di cascina viarengo, intagliata nei sedimenti del complesso lnferiore (unita di s. martino), sulla quale poggia ii termine inferiore del complesso superiore (unita di cascina gherba). l'affioramento e limitrofo all 'ex-cava di cascina arondelli, oggi non piu visibile, ubicato sul versante opposto della piccola valle percorsa dalla strada che porta all'abitato di gorla, ad una quota leggermente inferiore: entro i sedimenti siltosi dell'unita di s. martino e stata rinvenuta, negli anni '60, da berzi et af.(19) una fauna ricca di micromammiferi poi indicata come unita faunistica di cascina arondelli. l'affioramento e costituito nella parte inferiore da alternanze di sedimenti siltosi e sabbiosi fini, osservabili per uno spessore di circa 8 m. i sedimenti siltosi sono caratterizzati da laminazione pianoparallela o da assenza di laminazione. contengono localmente fru­ stoli vegetali e molluschi continentali: presentano inoltre orizzonti di colore grigio scuro con spessore centimetrico, caratterizzati da una notevole concentrazione di sostanza organica e dalla presenza di radici. i sedimenti sabbiosi mostrano invece laminazione incrociata planare o sono privi di laminazione. la notevole estensione laterale dell'atfioramento consente di valutare l'andamento complessivamente lenticolare dei carpi sedi­ mentari , che risulta invece tabulare nel dettaglio. fra le discontinuita mesostrutturali che interessano localmente i livelli dell'unita di san martino sono da ricordare i piani di taglio, a basso angolo e movimento, inverso a direzione n80°e, con immersione sia verso sse che verso nnw. i sedimenti descritti risultano troncati verso !'alto da una evidente superficie di erosione, sottolineata dall'andamento piu arretrato della parete: questa e la superficie di erosione principale riconosciuta entro la successione villafranchiana, indicata come superficie di cascina viarengo che separa ii complesso lnferiore da quello superiore (fig. 9) ; ad essa e associata una debole discordanza angolare (cir. profili geologici allegati alla monografia) . al di sopra di questa superficie si osservano, per uno spessore di 5 m circa, i sedimenti sabbiosi e sabbioso-ghiaiosi dell'unita di (18) leeder m. (1987} • sediment deformation structures and the palreotectonic analysis of sedimentary basins, with a case•study from the carboniferous of the northern england. in: jones m.e. & preston r.m.f. (eds.) (1987) deformation of sediments and sedimentary rocks. geol. soc. america spec. publ.; . n. 29, p. 137·146. (19) berzi a. , micheaux j., hutchinson j. h., lindsay e. (1967) the arondelli local fauna, an assemblage of small vertebrates from the villafranchian stage near villafranca d'asti, italy. giornale di geologia, 35, 1, 1 ·4 cascina gherba. questi mostrano una evidente stratificazione incrociata concava, sot­ tolineata localmente da concentrazioni di ossidi di ferro e di manganese; in essi non sono stati rinvenuti resti paleontologici di alcun genere. a sottolineare l'importanza della superficie di erosione descritta si osserva che l'addensamento dei sedimenti dell'unite di cascina gherba (complesso superiore) risulta decisamente inferiore rispetto a quello dei sedimenti dell'unita di cascina s. martino (complesso lnferiore): questa differenza e sottolineata, come gie ricordato, dall'andamento piu arretrato del !ratio di parete impostato in questi ultimi. durante ii modellamento del rilievo nella successione villafranchiana, questa e stata intagliata a piu livelli (entro alle incisioni vallive) da una successione di superfici di erosione, di estensione va­ --usm riabile, legate geneticamen­ te all'appro­ fondimento del retico lato idro­ g rafico: esse sono cronologi­ camente riferi­ bili all 'intervallo di tempo plei­ stocene me­ dio-olocene. in -·· b c d 671 fig . 8 proiezione stereografica (reticolo di schmidt, emisfero inferiore) della distribuzione degli elementi mesostrutturali : a) faglie inverse; b) faglie normali; c) fratture di taglio associate ad ondulazioni delta laminazione; d) altre fratture. stereographic projection (schmidt net, lower emi­ sphere) of mesotructural elements distribution: a) reverse faults; b} direct faults; c) shear frac­ tures associated with lamination waving; d) other fractures. fig. 9 rappresentazione schematica dell'affioramento di cascina s. martino. usm: unita di s. martino; scv: superficie di cascina viarengo; ug. unita di cascina gherba. schematic section of the "cascina s. martino" outcrop. usm: san martino unit; scv: "cascina viarengo' surface; ug: "cascina di gherba ' unit. corrispondenza del settore occidentale dell'affioramento di cascina s. martino e osservabile un lembo di superficie ter­ razzata legato geneticamente al t. triversa: e costituito in superficie da depositi alluvionali siltosi, caratterizzati da uno spessore di pochi decimetri. al di sopra dei depositi fluviali recenti si nota una copertura di prodotti colluviali connessi con la successiva evoluzione del versante sovrastante. in settori prossimi a quello in oggetto, in rapporto con lembi di superfici terrazzate quaternarie, sono stati rinvenuti diffusamente manufatti in selci e quarziti microcristalline, attribuibili al paleolitico antico. lo studio di questi reperti ha permesso di riferire alcuni episodi di approfondimento del reticolato idrografico all'interno della successions villafranchiana al passaggio ira pleistocene medio e superiore . venerdi 24 giugno 1994 ii percorso di awicinamento all'itinerario geologico sare lo stesso del giorno precedente. superata villanova si prosegue lino a s. paolo solbrito, ubicato sul giglio della scarpata che segna ii margine orientale dell 'altopiano di poirino. di qui si prende a sinistra e si prosegue lungo la strada che corre lungo ii giglio della scarpata stessa: a sinistra si puo osservare la caratteristica morfologia dolce­ mente ondulata dell 'altopiano di poirino, mentre a destra si estendono i rilievi dell'astigiano le cui sommite solo in alcuni tratti di svi­ luppano a quote superiori a quelle dell'altopiano di poirino. percorsi 2 km circa, ad un quadrivio si prende a destra la strada che scende la scarpata e si dirige verso est. questa scende inizialmente lino sul fondo della valle del t. traversola, impostata in corri­ spondenza di una fascia di deformazione, di cui la scarpata che segna ii margine orientale dell'altopiano di poirino rappresenta l'espressione morfologica; tale fascia suddivide la parte settentrionale dell'area-tipo della successione villafranchiana in alcuni settori differenziabili per spessore delle diverse unite e quota delle superfici di appoggio basale. a partire dal versante sinistro della valle del t. traversola e inoltre rilevabile verso est una fascia di disturbo nell'assetto giacitu­ rale delle unite costituenti la successione villafranchiana che registrano un improwiso incremento di inclinazione (lino a 25°); lungo tale fascia, orientata n120°e la quota di appoggio basale delle unita del complesso superiore aumenta bruscamente verso nord men­ ire diminuisce lo spessore affiorante dell' unita di marello. oltrepassato ii ponte sul corso d'acqua, si lascia ii pullman e si effettua un breve percorso a piedi verso sse per raggiungere lo stop 6. stop 6: cascina viarengo (7 km a nw di villafranca d'asti, in comune di s. paolo-solbrito) 672 l'affioramento e situato lungo la valle del t. traversbla, 600 m a sw di cascina viarengo, nella fascia altimetrica compresa tra 210 e 220 m. in questo settore, sviluppato in prossimita del mar­ gine nordoccidentale dell'area-tipo, affiora la parte superiore della successione villafranchiana: in par­ ticolare e osservabile localmente la superficie di erosione di cascina viarengo che separa i sedi­ me nti del complesso lnferiore da quelli del complesso superiore. nella parte inferiore dell'affioramento sono osservabili, per uno spes­ sore di circa 4 m, alternanze di spessore decime­ tri co di sedimenti siltosi, caratterizzati prevalentemente da laminazione pianoparallela, e di sedimenti sabbiosi minuti, prevalentemente privi di stratificazione. i sedimenti siltosi contengono ~--~~d_eposl~luvlall terrazzatl postvlllafranchlanl maretto · .' .---.:__-~ccesslone marina prevlllafran~hlana --.-· · . . .: .. -· .. -· . . . .. -·. . ' molluschi continentali, concentrati in corrispondenza a orizzonti di colore grigio scuro legati all'abbondanza della sostanza organica. sono state rilevate fratture subverticali appartenenti ai due principali sistemi che caratterizzano ii settore nordoccidentale dell'area­ tipo del villafranchiano, diretti in media rispettivamente n-s e n120°e. ii primo e qui rappresentato da piani le cui direzioni variano tra n10°w e n30°e con notevole dispersione: le fratture di tale sistema mostrano un'inclinazione media di circa 80° verso est. um --· ,· . . . . .__,. . ~~ . · .. . fig. 10 rappresentazione schematica dell 'affioramento. usm: unita di s. martino; scv: superficie di cascina viarengo; ug: unita di cascina gherba; um: unita di maretto. schematic section of the outcrop. usm: san martino unit; scv: "cascina viarengo " surface; ug: "cascina di gherba " unit; um: maretto unit. sviluppano sedimenti siltoso-argillosi riferibili alla sovrastante unita di maretto. nella parte superiore dell'affioramen­ to sono osservabili sedimenti siltosi fitta­ mente laminati , i quali appaiono troncati verso l'alto da una evidente superficie di erosione (superficie di cascina viarengo) (fig. 10): questa e caratterizzata nel detta­ glio da un andamento sensibilmente ondu­ lato per la presenza di depressioni profonde oltre 50 cm . al di sopra della superficie di erosione si sviluppano sedimenti sabbiosi grossolani, osservabili per uno spessore di oltre 3 m, riferibili all'unita di cascina gherba (complesso superiore). questi sedimenti sono caratterizzati da una stratificazione incrociata concava a grande scala. essi pre­ s e ntano piccole fratture con direzione n20°e, caratterizzate da un andamento ondulato sul piano verticale; si tratta di frat­ ture di tensione sottolineate da sottili riempi­ menti di sabbia. al tetto di questi depositi si poche centinaia di metri a nord dell'affioramento si sviluppa la struttura disgiuntiva con direzione 1200, indicata come "zona di faglia di cascina fagliaverde", responsabile del sollevamento di circa 30 m del settore nordorientale rispetto a quello sudoccidentale. ii rigetto della struttura e valutabile confrontando lo sviluppo altimetrico della superficje di erosione di cascina viarengo in corrispondenza ai due lati della struttura: tale superficie e sviluppata a circa 215 m immediatamente a sw, come visibile nell'affioramento in esame, e a circa 245 m immediatamente a ne, in prossimita di madonna di casale. alcune centinaia di metri a ovest dell'affioramento inoltre si sviluppa la "zona di deformazione del t. traversbla", con direzione media n-s, che costituisce la manifestazione superficiale di una fascia di deformazione che riveste un ruolo molto importante nell 'asset­ to dell'intera area, separando un substrato pre-messiniano di pertinenza alpina ad ovest, da uno di pertinenza appenninica a est. tornati sul pullman, si riprende la strada verso ene e si attraversa la dorsale che separa la val traversbla dalla val triversa, modellata in questo tratto nel settore situato a nord della zona di fag lia di cascina fagl iaverde : le formazioni affioranti sono le sabbie dell'unita di ronco, quelle dell 'unita di ferrere e, limitatamente alle sommita delle coll ine, le litofacies dell'unita di s. martino. giunti al bivio di montafia, si svolta a destra in direzione sud e si segue per un tratto di circa 4 km la strada di fondovalle; ad un bivio con indicazioni per roatto, si svolta a sinistra, in direzione est, e si supera la dorsale che separa la val triversa dalla valle di 673 maretto. al bivio sul fondo di quest'ultima si lascia ii pullman e, percorsi circa 200 m, si raggiunge lo stop 7. poiche le successioni strati­ grafiche esposte nei prossimi due stop sono simili , viene rappresentato un unico schema per entrambe. stop 7: case beltramo (5 km a ne di villafranca d'asti, in comune di maretto) l'affioramento e situato sul versante sini­ stro della valle di maretto 50 m a sw di case beltramo, nella fascia altimetrica compresa tra 215 e 220 m. in questo settore, sviluppato al margine orientale dell'area-tipo, affiora la parte medio­ superiore della successione villafranchiana: solo la fascia inferiore dei versanti e infatti modellata nei sedimenti del complesso lnferiore (unita di s. martino); al di sopra si svi­ luppano i sedimenti del complesso superiore ira i quali sono ben rappresentati e affioranti con relativa continuita i depositi sabbiosi dell'unita di cascina gherba. l'affioramento pressoche continua delle sabbie e sottolineato dalla presenza di numerose sorgenti legate al ---------d~ep~~!!..!_~~~ t~~l_postvlllafranchlanl -~ccess!one_ marina prevlllafran~hlana ·, ..--.. -· fatto che le sabbie ospitano una falda idrica sostenuta dai sottostanti depositi siltosi dell 'unita di s. martino. l'affioramento permette di osservare, per uno spessore complessivo di circa 6 m, i sedimenti sabbiosi di questa unita, carat­ terizzati da stratificazione incrociata concava e dalla presenza di mud c/asts di dimensioni centimetriche . al di sopra delle sabbie si osservano, per lo spessore di circa 1 m, i sedimenti siltoso-argillosi dell 'unita di marello, mal esposti nella piccola nicchia di distacco di uno scoscendimento. la particolarita dell'affioramento consiste nell'esistenza, in corrispondenza al limite fra le due unita, di una sensibile cementazione carbonatica che interessa la parte superiore delle sabbie: la cementazione interessa uno spessore notevole (circa 1 m) e sottolinea la stratificazione incrociata, rendendola piu evidente. l'origine di questi fenomeni di cementazione secondaria di carbonati e legata, secon­ do ogni evidenza, alla risalita ed alla diffusione di fluidi idrotermali, connessi con ii complesso e vivace assetto tettonico dell'area. tornati al pullman, si risale fino a maretto e di 11 si prende la strada che in direzione sw scende nuovamente sul fondo della val triversa. si segue la strada che corre sul fondovalle di quest'ultima per un tratto di circa 4 km fino a incrociare l'autostrada torino­ piacenza, la strada statale e la ferrovia. oltrepassate queste importanti vie di comunicazione, si aggira verso est l'abitato di villafranca e si risale la strada della valle maggiore (gia percorsa in senso contrario ii giorno precedente per portarsi dallo stop 2 allo stop 3). la si ripercorre fino ad oltrepassare la dorsale che separa la valle maggiore dalla testata della valle del t. stanavasso e, superato l'abitato di ferrere, dopo circa 1 km si lascia ii pullman. effettuato un breve percorso a piedi su strada asfaltata (non percorribile pero con ii pullman) si raggiunge lo stop 8. stop 8: cascina volpiano (5 km a sw di villafranca d'asti, in comune di valfenera) l'affioramento e situato sul versante sinistro della valmaggiore, 200 m a ne di cascina volpiano, nella fascia altimetrica com­ presa tra 250 e 260 m. in questo settore, sviluppato al margine sudoccidentale dell 'area-tipo, affiorano ~ssenzialmente i sedimenti del complesso superiore: solo la fascia altimetrica inferiore dei versanti e modellata nei sedimenti del complesso lnferiore. l'affioramento mette in luce i sedimenti sabbioso-ghiaiosi dell'unita di cascina gherba, osservabili per uno spessore di circa 7 m, sui quali poggiano i sedimenti siltoso-argillosi dell'unita di maretto, esposti su uno spessore di circa 2 m. i sedimenti mostrano stratificazione incrociata concava a grande scala, evidenziata dalla presenza di superfici di erosione conca­ ve: al di sopra di queste si sviluppano sequenze di sedimenti via via piu fini verso l'alto, caratterizzati da una gradazione della frazione ghiaiosa e dalla presenza, nella parte superiore, di carpi lenticolari siltosi con spessore centimetrico. la frazione sabbiosa e costituita da una netta prevalenza di granuli di quarzo. ii sedimento mostra complessivamente colore grigio: solo localmente si riconoscono modeste concentrazioni di ossidi di ferro e di manganese. la frazione ghiaiosa, relativamente poco abbondante, e formata in preva­ lenza da elementi di quarziti e quarziti conglomeratiche ("anageniti" auct.) e subordinatamente da dolomie, gneiss, diaspri e arenarie. complessivamente questi sedimenti sono caratterizzati da un addensamento molto modesto, che determina una morfologia molto dolce ed una pressoche totale assenza di affioramenti. 674 i sovrastanti sedimenti siltosi risultano invece privi di stratificazione e mostrano una evidente fessurazione prismatica a scala centimetrica, legata alle contrazioni per disseccamento: a sottolineare ii contatto ira le due litofacies si sviluppa un orizzonte carbonati­ co con spessore fino a circa 20 cm. le discontinuita strutturali alla mesoscala rilevabili nell 'affioramento sono rappresentate da fratture subverticali con direzione n50°e, n80°e e n120°e. la costituzione della frazione sabbiosa, formata in netta prevalenza da quarzo, e la modesta sfericita dei granuli valgono a diffe­ renziare ulteriormente i sedimenti sabbiosi dell 'unita di cascina gherba da quelli dell'unita di ferrera, in cui si osserva invece una rile­ vante frazione micacea e i granuli presentano maggiore sfericita le dolt. giulia nocchi e roberta marchesini, del dipartimento di scienze della terra dell 'universita di ferrara, coadiuvate da un gruppo di studenti del corso di geologia del quaternario dell 'universita di torino, hanno effettuato la vagliatura di circa 2 me di questi sedimenti nella speranza di recuperare denti di rod itori spesso presenti in sedimenti di questo tipo: sono stati recuperati solo un incisi­ ve di roditore, non significativo ai fini di una classificazione, ed alcuni opercoli di pomatias che, in base alle osservazioni di 0. girotti, non appaiono appartenere alle specie attualmente viventi in italia e non corrispondono neppure a quelli descritti e figurati da sacco. ii problema di individuare un affioramento dell'unita di maretto con caratteri di rappresentativita tali da farlo visitare ai partecipan­ ti di questa escursione e state veramente arduo: come si e avuto piu volte occasione di ricordare, questa unita da luogo a rari affiora­ menti, tutti di ridotta estensione ed in ogni caso soggetti ad evoluzione molto rapida. e' questo ii motive per cui nelle pagine che seguono verra riportata la descrizione di ire affioramenti di questa unita: saranno le condizioni meteorologiche (soprattutto quelle dei giorni immediatamente precedenti l'escursione) e le informazioni che ci verranno fornite al momenta della partenza del secondo giorno dell'escursione, da parte di persona del luogo, che ci faranno optare, all'ultimo momenta, per l'uno piuttosto che per l'altro dei tre . non siamo quindi in grade di descrivere l'itinerario che ii pullman percorrera per raggiungere l'affioramento prescelto: si trattera in ogni caso di uno stop in cui non saranno possibili osservazioni di carattere stratigrafio ma ci si limitera ad esaminare la litofacies prevalente nell'unita di maretto; riteniamo comunque importante la visita di uno di questi affioramenti per completare ii quadro delle conoscenze del villafranchiano-tipo e per comprendere alcuni elementi importanti di supporto al modello interpretative proposto a con­ clusione del lavoro di revisione . si fa presente che l'accesso di tutti e tre gli affioramenti descritti non pub definirsi particolarmente agevole: pensiamo valga comunque la pena di visitarli anche per renderci canto del perche ii complesso superiore non sia mai state oggetto di interesse da parte di altri ricercatori. in tutti e ire gli affioramenti la situazione stratigrafica esposta e praticamente la stessa per cui la loro posizione nello schema dei rapporti stratigrafici e stata indicata in un'unica rappresentazione di seguito riportata. stop 9a: ca' nuova (5 km a nord di villafranca d'asti , in comune di roatto) · _· -~ -~ccess)o~e. marina prevlllafran~hlana ··-:.. -· sia la sovrastante, potente copertura colluviale. l'affioramento e ubicato sul versante destro della valle di maretto, 50 m a sw di ca' nuova nella fascia altimetrica compresa tra 235 e 245 m. in corrispondenza al margine nordorientale dell'area-tipo, sensibilmente incise dal reticolato idrografico, affiora l'intera successione villafran­ chiana: alla base dei versanti si osservano infatti i termini marini (unita di ronco), nella fascia inter­ media i sedimenti del complesso lnferiore (unita di ferrere e di s. martino) e infine sulla sommita dei rilievi i sedimenti del complesso superiore (unita di cascina gherba e di maretto). l'affioramento e ubicato in corrispondenza della nicchia di distacco di un dissesto gravitati­ ve che coinvolge sia i sedimenti villafranchiani alla base dello spaccato si possono osservare i sedimenti sabbiosi dell'unita di cascina gherba, affioranti per uno spessore di circa 4 m, sui quali poggiano i sedimenti siltosi dell'unita di maretto, esposti per uno spessore di circa 2 m: risulta quindi particolar­ mente ben esposta la sovrapposizione in continuita stratigrafica dei sedimenti delle due unita. i sedimenti sabbiosi sono caratterizzati da stratificazione incrociata concava e sono interessati da evidenti fratture subverticali: la loro natura distensiva e suggerita dalla presenza di riempimenti sabbiosi. i sedimenti siltosi risultano privi di stratificazione. stop 9b: cascina ciocchero (8 km a nw di villafranca, in comune di buttigliera d'asti) 675 gli affioramenti sono situati sul versante destro della valle traversola, 300 m a se di cascina ciocchero nella fascia altimetrica compresa tra 235 e 255 m. al margine nordoccidentale dell'area in esame e osservabile la parte medio-superiore della successione villafranchiana: nella fascia inferiore dei versanti affiorano i sedimenti de! complesso lnferiore (unita. di s. martino), nella fascia intermedia i sedimenti de! complesso superiore (unita. di cascina gherba e di maretto) e al di sopra si sviluppano con continuita. i depositi fluviali terrazzati post­ villafranchiani costituenti in superficie l'altopiano di poirino. in particolare in corrispondenza alle testate delle piu marcate incisioni del reticolato idrografico vengono localmente in luce i sedimenti dell'unita di maretto, altrove difficilmente osservabili . gli affioramenti sono ubicati in corrispondenza all'incisione di un piccolo corso d'acqua non riportata nella cartografia topografica: risalendo quest'ultima sono osservabili numerosi, ridotti affioramenti che consentono complessivamente l'osservazione di uno spesso­ re di una ventina di metri della successione. alla base dell'incisione sono presenti, non esposti in questi affioramenti, i sedimenti sabbiosi dell'unita. di cascina gherba. i primi affioramenti, dal basso, mettono in luce i sedimenti siltoso-argillosi dell'unita di maretto: questi risultano privi di stratifica­ zione e caratterizzati da una colorazione grigio-cenere, caratteristica della porzione basale non ossidata dell'unita.. localmente si osservano intercalazioni sabbiose di spessore decimetrico. questi depositi risultano qui particolarmente ricchi di concrezioni carbonati­ che, che si possono osservare lungo tutta l'incisione, dove risultano concentrate dall 'azione del corso d'acqua. complessivamente i sedimenti siltoso-argillosi messi in luce in tutto lo sviluppo dell'affioramento presentano caratteristiche sen­ sibilmente omogenee, tali da consentirne la distinzione rispetto ai sedimenti dell'unita. di s. martino, anch'essi prevalentemente siltosi ma decisamente piu addensati, caratterizzati in genere da strutture sedimentarie ed associati sempre ad altre litofacies. i risultati delle analisi palinologiche di campioni prelevati da questi affioramenti, effettuate da r. caramiello e da a. zeme, (siglati "ciocchero in alto nel fiume" e "ciocchero lungo fiume") hanno indicate la presenza di pinus, abies, quercus, cory/us, tilia, a/nus, chopodiaceae e filicali monolete. stop 9c: cimitero di s. paolo (1 km a nord dell'abitato di s. paolo, in comune di s. paolo-solbrito) gli affioramenti, in condizioni morfologiche molto simili ai precedenti, sono presenti lungo l'incisione di un piccolo corso d'acqua uti lizzato come discarica: vi si osservano sedimenti siltoso-argillosi di colore grigio-cenere, massivi, dalle cui fratture esce sempre dell'acqua (negli affioramenti piu bassi). sano presenti intercalazioni sabbiose, grigie e fini nella porzione inferiore e di colore ocraceo e molto piu grossolane verso !'alto (ricordano alcune litofacies dell'unita di ferrere); i granuli di dimensioni maggiori sono quarzosi e mostrano contorni angolosi. tutta la formazione, soprattutto in corrispondenza ai livelli siltoso-argillosi, appare impregnata di concrezioni carbonatiche bian­ castre cha sono diffuse nella massa e non concentrate come invece avviene altrove. alcune sottolineano delle fratture verticali. la particolare abbondanza di questi carbonati secondari e da mettere in relazione con la localizzazione dell 'affioramento, in corrisponden­ za alla scarpata che segna ii margine orientale dell'altopiano di poirino e che rappresenta l'espressione morfologica della fascia di deformazione del t. traversola. si nota una complessiva inclinazione di circa 5° verso wnw. localmente si osservano faglie a basso angolo con immersione verso est: la loro presenza e pure da mettere in relazione con la particolare situazione strutturale in cui si collocano gli affioramenti. questa circostanza fa sl che l'aspetto complessivo dell'unita di maretto qui osservabile non possa essere considerata particolarmente rappresentativa. tuttavia si e deciso di inserire nell'escursione la visita di questi affioramenti essendo questi quelli piu estesi e relativa­ mente meglio esposti di questa unita.. anche in questi affioramenti sono stati prelevati dei campioni ("sp1", "sp2") di cui r. caramiello e a. zeme hanno verificato ii contenuto pollinico: sono stati riconosciuti pinus, cory/us, betula, populus, hordeum, rumex, a/nus e gramineae l'itinerario del secondo giorno di escursione si concluders. con la visita ad uno scavo fatto appositamente eseguire in un lembo di superficie subpianeggiante nei pressi dell'abitato di valfenera. per raggiungere ii punto di fermata si percorrera la strada che corre lungo ii ciglio della scarpata che segna ii margine orientale dell'altopiano di poirino: si avra. cosl continuamente l'occasione di osserva­ re da un lato e dall'altro del pullman la singolare situazione morfologica piu volte ricordata. superato l'abitato di valfenera, si proce­ dera verso sud fino a portarci alle porte della frazione villata, ubicata nei primi rilievi collinari che si sviluppano a est della scarpata. scesi dal pullman, all'altezza del cimitero di questa frazione, si percorreranno poche decine di metri per raggiungere lo stop 10. stop 10: villata (7,5 km a sw di vil lafranca d'asti, in comune di valfenera) lo stop e ubicato 300 m a nord dell'abitato di vil lata, alla quota di circa 31 o m. oggetto dell'osservazione e la successione espo­ sta in uno scavo fatto eseguire appositamente. vi si riconoscono i "depositi fluviali terrazzati posvillafranchiani" che in occasione dello stop 1 della prima giornata si aveva constatato costituire in superficie l'altopiano di poirino. l'aratura effettuata nell'area circostante ne 676 stop10 .,.~~~~..!d~eposl~all terrazzatl postvlllafranchlanl maretto ~ccess~one_ marina prevlllafranchlana •·-.--.. -· mostrano l'aspetto superficiale, tipicamente rubefatto. nello spaccato si osservano, dall'alto al basso, sedimenti siltoso-argillosi dapprima rossastri (5 yr 5/8 nelle notazioni delle munsell soil color charts), ricchi di patine di argilla, di slicken-sides e di screziature di colore, che passano in maniera sfumata verso ii basso a sedimenti siltoso-argillosi di colore grigiastro o bruno. e' appunto la natura graduale del limite a far capire che i sediment! sui quali si sviluppa ii suolo fanno parte della stessa unita cui appartengono i limi argillosi sottostanti. in questo affioramento non e possibile osservare ii limite tra i sedimenti dell'unita di maretto ed i "depositi fluviali terazzati postvilla­ franch ian i", percha quest'ultimo complesso raggiunge qui uno spessore di una decina di metri. e' solo la situazione morfologica, che corrisponde a quella di una superficie sommitale subpianeggiante, integrata dalla conoscenza regionale, piu che la differenza di litofa­ cies, francamente non avvertibile alla scala del singolo affioramento, che consente di comprendere come i sedimenti descritti non fac­ ciano parte della successione villafranchiana ma costituiscano un complesso decisamente piu recente, di origine fluviale . tali sedimenti sono conservati in lembi di superfici relitte, i quali costituiscono i resti dell'originaria prosecuzione verso est del settore cen­ tromeridionale dell'altopiano di poirino. vill 1-1 vill 2-2 vill 1-3 vill 2-4 vill 1-5 vill 2-6 vill 2-7 vill 2-8 vill 2-9 vill 2-10 vill 1-11 vill 2-12 vill 1-13 vill 1-14 vill 1-15 vill 2-16 vill 2-17 vill 1-18 vill 2-19 vill 2-20 vill 2-21 vill 2-22 sess 4_17022011.pub il quaternario italian journal of quaternary sciences 24, (abstract aiqua, roma 02/2011), congresso aiqua il quaternario italiano: conoscenze e prospettive roma 24 e 25 febbraio 2011 lake evolution since the bronze age in the lower mincio river valley and the forcello etruscan harbour (central po plain) cesare ravazzi1*, mauro marchetti2, marco zanon1, renata perego3, lorenzo castellano1, massimiliano deaddis1, mattia de amicis4, claudia fredella5, davide margaritora1, raffaele de marinis5 & tommaso quirino5 1 c.n.r., istituto per la dinamica dei processi ambientali milano, italy 2 dip. scienze della terra, università di modena e reggio emilia – modena, italy 3 ipna, basel, switzerland 4 disat, università di milano bicocca, italy 5 dip. scienze dell’antichità, università degli studi di milano, italy * corresponding author: c. ravazzi <cesare.ravazzi@idpa.cnr.it> abstract: ravazzi c. et al., lake evolution since the bronze age in the lower mincio river valley and the forcello etruscan harbour (central po plain). (it issn 0394-3356, 2011) the etruscan harbour of forcello in lower valley of the mincio river, n-italy, was active between the vi to iv centuries bc. the stratigraphic investigations revealed that the settlement occupied a hill on the shore of a large lake, connected to the mantua perifluvial lake system. the lake formed between the late bronze age and the early iron age in the embanked floor of the mincio valley, and persisted till the late middle age. the diversion of the po river at guastalla during the iron age is considered responsible for damming the mincio river at its confluence. riassunto: ravazzi c. et al., evoluzione lacustre della bassa valle del mincio a partire dall’età del bronzo e il porto fluviale etrusco del forcello (pianura padana centrale). (it issn 0394-3356, 2011) la città portuale del forcello, situata nella bassa valle del fiume mincio (n-italia), fu attiva tra il vi e il iv secolo a.c. nuove indagini stratigrafiche hanno stabilito che l’abitato sorgeva su un dosso alla riva di un lago esteso per almeno 5 km. il lago si sviluppò a cavallo tra l’età del bronzo e l’età del ferro e persistette sino alla bonifica del tardo medioevo. si avanza l’ipotesi che l’origine sia connessa con la diversione del po a guastalla nell’età del ferro e il conseguente sbarramento del mincio alla sua foce. key words: bronze age, etruscan harbour, forcello, fluvial dynamics, forest history, plant goods trade parole chiave: età del bronzo, porto etrusco, forcello, dinamica fluviale, storia forestale, commercio di merci vegetali one of the most important etruscan settlements in northern italy (forcello, 16 m a.s.l., vi to iv century bc), was built in the valley of the mincio river. the forcello harbour allowed fluviatile trades connecting the eastern mediterranean basin and continental europe (de marinis & rapi, 2005). in 2008, a stratigraphic research was undertaken with the aim to look for plant goods trade and to reconstruct the landscape surrounding the site from charcoal and pollen assemblages preserved in the settlement and in the lowland sediments surrounding the site. a main question is attached to the reasons why etruscans did settle the main trading post for the padanian uplands well inside the mincio valley, instead that along the po river. stratigraphic evidence of the origin and evolution of the bagnolo lake. a transect of semidisturbed drilling across the hill hosting the etruscan settlement and slopes towards the mincio valley floor allowed discovering a succession of openwater lake sediments formed by marly-silts and shell marly silts, overlapping palustrine and hydromorphic soils. in turn, the palustrine organic accumulation rests over channeled sequences of laminated, well sorted sand. we extended the coring campaign downstream, thus highlighting that the lake sequence increases in thickness. this proves that the lake occupied the mincio embanked valley at least between mantua and bagnolo (fig. 2a). a set of radiocarbon dating and loi analysis on the master core (fig. 1) shows that the pre-lacustrine phase of organic accumulation extends over part of the bronze age, while an age of 500-700 yr cal bc, close to the lake sequence base, set the origin of the bagnolo lake between the late bronze age and the early iron age. the lake existed all along the etruscan and the subsequent roman and middle ages, in agreement with historical sources that a lake there was being dried up artificially late in the middle age (de marinis, 1991). the above data show that the forcello harbour flourished on the border of a low terrace bordering the shore of a large perifluvial lake, at least 5 km long, constrained into the deeply embanked mincio valley. downstream, the lake was connected to the po river. hence, assuming that the evolution of the bagnolo lake is linked to the perifluvial lake system 202 204 203 of mantua (sestini, 1957), there were more than the existing three lakes, before human alterations (see fig. 2b). the threshold supporting the lake basin was located downstream of the bagnolo town, thus the dam was unrelated to the change of channel direction near mantua (fig. 2), otherwise considered a river anomaly (burrato et al., 2003). iron age avulsion of the po river, origin of the bagnolo lake and etruscan shipping. figure 2b shows the reconstructed river network in the central po plain after the diversion of the po river at guastalla and the abandonment of the bondeno channel segment, the latter active throughout most of the bronze age. this event, dated back to the iron age (castaldini, 1989), caused overflooding of a wide belt of the plain between suzzara, ostiglia and mirandola. as a matter of fact, this belt lacks evidence of bronze age settlements, buried under the overbank cover. the new drainage pattern established at the iron age acknowledged a strong discharge increase of the po river at the confluence with the mincio r., due to contribution of two main alpine rivers (adda and oglio) previously independent from the po. we suggest that the displacement of these drainage axes in front of the mincio valley mouth (fig. 2b) reduced flow velocity, increased the sediment load (mainly of apennine source rather than alpine), caused damming and establishment of a permanent lake system in the terraced valley. in agreement with location and economical relevance of major iron age settlements in the lowermost po plain (i.e. the town of adria), we argue that the modification in the fluviatile network promoted upstream shipping from the northern adriatic till the bagnolo perifluvial lake, where a main harbour was thus settled. plant good trades and forest history around the forcello harbour. the bagnolo lake was kept until middle age reclaiming; hence lacustrine sediments registered the forest history and human activities since the time of the etruscan settlement till xiv century ad. the archaeobotanical investigation (pollen, charcoal, and other plant macroremains) carried out in the forcello archaeological layers (phase f) is still in progress. many useful plants (aboveall pulses) and weeds were identified, together with a smaller amount of wild plants of wet environments. altogether they provided information on the diet of the etruscans and on some supposed imported plants. besides, an offsite palynological investigation from the lacustrine succession is being carried out. according to the radiocarbon dating, the record extends from the late bronze age to the late middle ages. the pollen record testifies the roman forest clearings and shows unprecedented evidence of an early middle age phase of abandoning. finally, an overall change in land use is dated at the x century ad. first occurrences of species important for the palaeoenvironmental history in northern italy, such as walnut and chestnut, are also documented here. particularly walnut pollen already increases around viii century bc, well before its appearance at the southern border of the alps, testifying its older introduction in the lower po plain by the etruscan people. references burrato p., ciucci f. & valensise g. (2003) an inventory of river anomalies in the po plain, northern italy: evidence for active blind thrust faulting. annals of geophysics, 46, 865-881. castaldini d. (1989) evoluzione della rete idrografica centropadana in epoca protostorica e storica. acc. sc. ferrara, 115-134. de marinis r.c. (1991) l’abitato etrusco del forcello: opere di difesa e di drenaggio e importanza delle vie di comunicazione fluviale. in: m. bergamini (a cura di) gli etruschi maestri di idraulica. perugia, 75-85. de marinis r.c. & rapi m. (2005) l’abitato etrusco del forcello di bagnolo s. vito (mantova). le fasi di età arcaica. università degli studi di milano. firenze. 311 pp. sestini a. (1957) l’italia fisica. touring club italiano, 320 pp. fig. 1 log of the master core, drilled in the lowland, 100 m e of the forcello hill border. log della carota principale, ottenuta nel fondovalle, 100 m ad e del margine del dosso del forcello. lake evolution since the bronze age in the lower mincio ... 204 ms. received: testo ricevuto il fig. 2 – geomorphological maps near forcello 2a) modern setting; 2b) v century b.c. legend: 1) rivers and lakes (dashed lines depict presumed fluvial tracks), 2) high water fluvial bed, mostly between main levees, 3) poorly drained lowlands, 4) alluvial ridge, 5) abandoned fluvial course, 6) main fluvial scarp, 7) crevasse splay area, 8) main plain level (surface marking the last aggradation phases, before the beginning of deglaciation). carta geomorfologica dei dintorni del forcello. 2a) assetto attuale; 2b) v secolo a.c. legenda: 1) fiumi e laghi (il tratteggio indica i tracciati fluviali presunti); 2) aree golenali, pricipalmente tra gli argini maestri; 3) aree depresse mal drenate; 4) dossi fluviali; 5) letto fluviale abbandonato; 6) scarpata fluviale principale; 7) ventaglio di rotta; 8) livello “fondamentale” della pianura (superficie limite dell’aggradazione dei conoidi durante l’ultimo massimo glaciale, prima della deglaciazione) january 7, 2011 7 gennaio 2011 c. ravazzi et al. imp.longhitano_zanini coastal models and beach types in ne sicily: how does coastal uplift influence beach morphology? sergio longhitano1, angiola zanini2 1 dipartimento di scienze geologiche, università degli studi della basilicata campus di macchia romana, 85100, potenza; e-mail: longhitano@unibas.it. 2 dipartimento di scienze geologiche, università degli studi di catania corso italia 55, 95100, catania; e-mail: zanini@unict.it. abstract: s. longhitano, a. zanini, coastal models and beach types in ne sicily: how does coastal uplift influence beach morphology? (it issn 0394-3356, 2005). this paper compares morphological and sedimentary characters of beach types occurring along the ionian coastline of ne sicily and local coastal uplift rates, with the aim of evaluating how vertical coastal movements influence beach morphologies. the ionian coastline of ne sicily may be divided into many coastal provinces and subprovinces, following the relative positions that each segment of littoral occupies within the general geological setting of the central mediterranean. this coastline runs perpendicularly along the africa-europe plate boundary, crossing successions belonging to the chain, volcanic products, a foredeep and a foreland sector. in this paper only the northern sector, pertaining to the chain and volcanic coastal provinces, is examined. from the south to the northern edge of ne sicily, four main localities were chosen for examination: (i) capo peloro/messina; (ii) taormina/giardini-naxos; (iii) riposto/praiola; (iv) ognina/catania. in these sites, a series of combined observations on the gradient of the nearshore profile, grain size of sediments, local water dynamics, and uplift rates identified classes of distinct beach types and models. results indicate that all these coastal profiles developed recently, due to vertical local tectonic movements rather than control by the width of the continental shelf, the morphology of which is strongly influenced by the malta escarpment fault system. differing coastal uplift rates define classes of beach types in which patterns of morphological and sedimentological characters, together with the hydrodynamics of the nearshore zone, are closely related to recent tectonic vertical movements of the coast. riassunto: s. longhitano, a. zanini, modelli costieri e tipi di spiaggia nella sicilia nord-orientale: come il sollevamento costiero influenza la morfologia della spiaggia? (it issn 0394-3356, 2005). la correlazione tra una serie di dati derivanti da uno studio di carattere morfologico e sedimentologico con i tassi di sollevamento calcolati lungo tutto il litorale ionico della sicilia nord-orientale ha permesso di identificare il grado di influenza che i movimenti verticali costieri possono avere sullo sviluppo dei differenti modelli di spiaggia. la costa orientale della sicilia può essere suddivisa in province e sotto-province costiere, in stretta relazione con le caratteristiche geologiche e geodinamiche che essa stessa presenta. il litorale percorre perpendicolarmente il margine di giunzione afro-europeo, attraversando, da nord verso sud, un dominio di catena, un dominio vulcanico, uno di avanfossa ed uno di avampaese. in questo lavoro vengono riportati i risultati che derivano dalle osservazioni condotte soltanto nel settore costiero di catena e vulcanico. da nord verso sud sono state considerate quattro principali località tipo: (i) capo peloro/messina, (ii) taormina/giardini-naxos, (iii) riposto/praiola e (iv) ognina/catania. in ognuna di queste località, sono state acquisite informazioni circa il gradiente del profilo sotto costa, il diametro medio dei sedimenti di spiaggia, le caratteristiche idrodinamiche locali e i valori relativi ai tassi di sollevamento dell’area costiera locale. la combinazione di questi parametri ha permesso di individuare distinte classi di differenti modelli di spiaggia. i risultati suggeriscono inoltre come la morfologia che caratterizza ognuno dei profili di spiaggia considerati è stata direttamente influenzata dall’azione dei movimenti di uplift costieri, piuttosto che dall’ampiezza della piattaforma continentale, che, tettonicamente controllata dal sistema di faglie della scarpata maltese, presente nel settore meridionale, si assottiglia progressivamente verso nord fino a scomparire del tutto. le differenti classi e modelli di spiaggia individuati per ciascun settore, mostrano pertanto altrettanto differenti sistemi di drenaggio a monte e caratteri morfo-sedimentologici che vengono direttamente controllati dai locali tassi di uplift. keywords: ne sicily; ionian coastline; coastal provinces; beach types; coastal uplift rate. parole chiave: sicilia nord-orientale; province costiere; modelli di spiaggia; tassi di sollevamento costiero. il quaternario italian journal of quaternary sciences 19(1), 2006 103-117 1. introduction the ionian coast of sicily (fig. 1) runs along the eastern part of the island, crossing an important geodynamic part of the central mediterranean. this littoral extends along terrains belonging to the africa-europe plate boundary, normal to the subduction direction (longhitano & zanini, 2005; 2006). in this geological setting, three structural coastal domains are identified: chain, foredeep and foreland. the three domains may be considered as a series of coastal compartments or provinces (sensu finkl, 2004), and include several examples of various beach types, each characterised by peculiar morpho-sedimentary features, in response to the geological setting within each segment of shoreline developed in recent times. the ionian coast of sicily has been studied in terms of its coastal dynamics and morpho-bathymetric features of the nearshore zone, sedimentary drift and budget, grain-size beach characteristics (amore et al., 1979; 1990), and meteomarine conditions (di geronimo, 1990; ferretti et al., 2003), disregarding the fundamen104 s. longhitano & a. zanini tal role of the coastal geological framework in the control of beach development. recent publications about coastal systems analyse the evolution of discriminated transects of different examples of shorelines from over the world in relation to recent tectonic evolution. in detail, quantification of uplift rates, fault control and relative morphological features of coastal environments identify separate geotectonic coastal provinces. recent anthropogenic influences are also included in the final evaluation of the coastal setting. this approach has been neglected in recent studies of the eastern coast of sicily, and this paper is a first preliminary approach on understanding of the coastline and its setting. this work describes and classifies some of the most representative beach types occurring along the northern segment of the ionian shoreline, using sedimentological, morphological and hydrodynamic datasets, in order to identify the various coastal provinces in relation to their respective geological settings and local uplift rates. 2. geological setting of ne sicily the north-eastern coast of sicily has a n-s (±30°) oriented shoreline, extending from capo peloro (north) and catania (south) (fig. 1). it faces the ionian sea and represents a microtidal oceanographic framework: here, only wave action and long-shore currents, controlled by the complex messina strait dynamics, influence coastal dynamics. the rivers outflowing on this coast are the main points of sedimentary input. they drain several areas, producing variable amounts of sediment, depending on lithology, gradient and headland altitude (which, in turn, controls the local rate of rainfall) of the respective drainage basins. from n to s, the zaffaria, d’agrò, letojanni, alcantara and macchia are the main rivers. the studied coastline is the northernmost geodynamic domain of the n-s geological transect (fig. 2). it lies above terrains representing the thin-skinned expression of a chain and the eastern flank of an active volcano, which, in turn, are counterparts of an extremely complex subduction zone running between the african plate (to the s) flexured beneath the european plate (from the n) (fig. 1, inset). 2.1 morphotectonics north-eastern sicily runs perpendicularly to the southern margin of the tyrrhenian basin, which includes calabria (gvirtzman & nur, 1999a,b). the study area consists of sedimentary and metamorphic rocks within a south-verging system of nappes of the appenine–maghrebian chain, overthrusting the northward-dipping african plate. the malta escarpment is the most important active tectonic structure influencing the evolution of the ne coast of sicily. it produces a dip-slip displacement, amounting to 3 km onshore. where it intersects the coast on the eastern side of mt etna, a series of active faults (the timpe fault system) occur, forming scarps of up to 200 m and fault planes displaying both dip-slip and right-oblique slip kinematic indicators (lanzafame et al., 1996; monaco et al., 1997). the orientation of the entire coastline within this domain is strongly controlled by the structural pattern fig. 1 ionian coast of sicily and geological setting (inset). many coastal provinces and subprovinces are identified, according to respective geological frameworks. the study sites mentioned in this paper are mainly located along the chain province, divided from n to s, into the peloritani mts and mt etna subprovinces. schema geologico generale della costa ionica della sicilia ed assetto strutturale (riquadro). il litorale può essere suddiviso in alcune province e sotto-province costiere in relazione al locale assetto geologico. il tratto costiero studiato per il presente lavoro interessa principalmente la provincia più settentrionale, ulteriormente divisa da n a s in peloritani mts subprovince e mt etna subprovince. of the faults dissecting the area. the most important structure intersecting the faults associated with the malta escarpment is the seismogenetic nne-sswstriking messina fault system which caused the messina earthquake (approximate magnitude 7.5) in 1908. this system defines the north-eastern coastline bordering the straits of messina and extends south to the taormina area. on strike, fault scarps also cut the surface of holocene deposits on the eastern side of mt etna, and are connected with the faults of the timpe system (lanzafame et al., 1996). the continental shelf flanking this coastal domain has a high gradient (3-4°) and a narrow seaward extension which progressively thins northwards (from 2.0 to 0.4 km). this complex structural setting has produced cliffed shorelines and promontories, and pocket, shingle and sandy beaches. each single type and its morphology also reflect the influence of lithology and uplift rate of the pertaining coastal province. 2.2 lithologic units the onshore lithologic units of the study area represent the southern flank of the calabrian-peloritani arc (amodio-morelli et al., 1976), formed of hercynian crystalline terranes, variously deformed according to a series of ese-verging thrust-sheet systems, and their cenozoic sedimentary covers (lentini et al., 1995; di stefano & lentini, 1995; lentini et al., 2000). synand post-orogenic sediments are represented by upper eocene and younger sequences, each indicating a stage in the polyphasic tectonic evolution of the area (lentini et al., 2000, and references therein). in detail, the main lithologic units are represented by the conglomerates and sandstone of the tortonian s. pier niceto fm, very thin messinian evaporite, pliopleistocene biocalcarenite and pleistocene-holocene coarse-grained fan deltas of the messina fm. the corresponding coastline has alternating gravelly/sandy shores and promontories. to the south, the volcanics of mt etna lie above the sedimentary meso-cenozoic successions. its recent effusive-type activity has been greatly influenced by the development of the neighbouring coast (longhitano & colella, 2007). in the last few centuries, lava flows from the eastern flank of the volcano have created a protrusive rocky shoreline, forming the northern margin of the gulf of catania. the volcanic coastal subprovince is characterised here by high cliffs, composed of resistent basalt alternating with scoriaceous lava flow deposits. 105coastal models and beach types ... all these lithologic units, differently involved in local drainage, are recognisable in the mineralogical composition of the sediments of the corresponding beach types pertaining to each single coastal province. sediment composition varies from metamorphic, carbonatic and arenaceous clasts on the northern coast, to fully volcanic on the southern coast. 2.3 uplift rates in the last few years, emphasis has been placed by the scientific community on evaluation of ne sicily coastal uplift rates and their relationship with onshore geology (bonfiglio & violanti, 1983; di grande & neri, 1988; firth et al., 1996; stewart et al., 1997; bordoni & valensise, 1998; rust & kershaw, 2000; monaco et al., 2000; antonioli et al., 2002, 2003; 2004a,b; kershaw & antonioli, 2004; antonioli et al., 2006). research on sea-level indicators (marine notches and 14c dated shells) close to the modern sea level at several locations along the coastline (firth et al., 1996; stewart et al., 1997; rust & kershaw, 2000; kershaw, 2000) show that different uplift rates were active during the pleistocene and the holocene. the messina strait area shows the highest longterm uplift rates in italy; bordoni & valensise (1998) indicate a rate of up to 1.2 mm a-1 over the last 125 ka. however, evidences reported by miyauchi et al. (1994) suggest that the sites of capo peloro and ganzirri are undergoing long-term uplift rates of 0.8 mm a-1. to the south, monaco et al. (2004) and antonioli et al. (2006) obtain holocene uplift rates of at least 2.4 and 1.2 mm a-1 for the taormina and capo sant’alessio localities (bordered by the messina fault system) and the etna area (bordered by the malta escarpment), respectively. new data from shell remains from the taormina area north of mt etna have been used to show that uplift over the past 6000 years (short-term) had a slower rate of about 1.4 mm a-1 (antonioli et al., 2003; kershaw & antonioli, 2004). 3. methods our observations were made along the studied coastline according to its geological characters and significance. for each site, shore profiles were measured, starting from mid-swash and moving landwards to the foredune. beachface sediments were sampled at points where relevant grain-size variations occurred. sampling density was designed with respect to the total length of profiles, varying from site to site and fig. 2 geological cross-section along ionian coast of sicily, showing coastal provinces and subprovinces proposed in this study. sezione geologica schematica attraverso la costa ionica della sicilia orientale, mostrante la suddivisione in province e sotto-province costiere proposta in questo lavoro. 106 depending on the local beach dimensions. sediment grain-sizes were compared with those of previous works (e.g. amore et al., 1992). statistics covered the means, standard deviations, skewness and kurtosis of grain sizes and settling velocity distributions of sediments. environmental parameters associated with the location of each sediment sample were determined from field observations and analysis of aerial photographs. beach morphology and shoreline stability were identified from bathymetric charts and interpretations deriving from previous works. for each single location, dean’s surf scaling (dss) parameter was calculated (dean, 1991), in order to define numerically the rate of energy dissipation or reflection along an idealised nearshore profi le. estimates take into account the characteristics of the dominant wave motion and the physical features of beach sediments, according to the following formula: hb ω = ––––– (1) ws t where hb and t are breaker height and period respectively, obtained from local measurement stations between january 2003 and january 2006, and ws is mean sediment fall velocity. parameter ws was obtained from the following formula: 2 a2 (σ – ρ) g ws = ––– –––––––––––– (2) 9 η in which a and σ are particle grain size (radius) and density, respectively; ρ is fluid (marine water) density; g is gravity acceleration, and η is fluid dynamic viscosity. formula (2) derives from stoke’s law, in which falling velocity is proportional to the square of the particle radius (allen, 1982). formula (1) was calculated for nine sites. results are summarised in table 1. 4. coastal provinces the northern segment of the ionian coast of sicily has a regular n30°-trending shoreline, composed of various beach types. this coastal domain has a total length of 107.36 km and extends from capo peloro (to the n) to catania (to the s). on the basis of geological table 1 hydrodynamic setting of nearshore profiles for study areas (from n to s) along ne sicilian coastline, according to dean’s surf scaling parameter values. mean breaker heights and periods obtained from in situ measurements and ‘catania buoy’, mainly from january 2003 to january 2006. see text for explanation on mean sediment fall velocity. identità idrodinamica calcolata nei confronti dei profili sotto costa di ciascuna area di studio (da n verso s) lungo la costa nord-orientale della sicilia, secondo i valori del dean’s surf scaling parameter. l’altezza media dei frangenti ed il periodo sono stati ottenuti da alcune misure in situ e principalmente dai dati della ‘boa di catania’, nel periodo gennaio 2003-2006. fare riferimento al testo per il calcolo del valore ws. site of mean breaker mean breaker mean sediment dean’s measurements height (hb) period (t) fall velocity (ws) surf scaling beach-type (from n to s) m sec cm . sec-2 parameter (ω) capo peloro/ganzirri 0.32 6.34 0.39 5.2 intermediate messina 0.22 4.00 0.20 4.2 intermediate rocca lumera 0.089 5 0.075 5.9 intermediate/dissipative letojanni 0.089 7.10 0.10 6.1 slightly dissipative taormina 0.089 3.30 0.36 0.8 slightly reflective giardini-naxos 0.045 6.30 0.16 1.7 intermediate riposto/praiola 0.750 1.50 56,25 0.02 highly reflective fondachello 0.750 5.40 40,5 0.1 reflective catania/ognina 0.048 2 32 0.003 very highly reflective fig. 3 overall seawater circulation of ne sicily. s-directed, long-shore currents, due to messina strait, hydrodynamics interact with clockwise, offshore circulation of ionian sea. circolazione marina del settore nordorientale della sicilia. le correnti lungo costa, dirette verso meridione e generate dallo stretto di messina, interagiscono con le correnti a largo dello ionio, producendo dei locali movimenti rotazionali in senso orario. s. longhitano & a. zanini 107 and morphological characters, this province may be further divided into two subprovinces: (i) a northern segment, consisting of the ionian side of the peloritani mts from capo peloro to the city of riposto (first 75.1 km), where the kabilo-calabride terranes outcrop; (ii) a southern segment, made up of the volcanics of the eastern flank of mt etna, down to the city of catania. 4.1 coastal hydrodynamics the peloritani subprovince, is the coastal segment most strongly influenced by the complex messina strait seawater dynamics (de domenico, 1987). throughout this narrow waterway, connecting the tyrrhenian to the n and the ionian to the s, reverse flows of strong tidal currents occur in phase opposition every six hours, whereas in the microtidal regime of the mediterranean, tidal currents run at a speed of 6 or 7 knots on the surface (montenat et al., 1987). these hydrodynamics control seawater movement along the peloritani coastal subprovince, where a fan of sdirected currents develops (fig. 3). these flows give rise to ssw-directed long-shore currents, controlling the coastal drift of sediments. the seawater dynamics of the messina strait also influence water circulation along the southern coastal subprovince, where generally s-directed long-shore currents flow. here, they interact with the volcanic promontory of the eastern flank of mt etna and with nne-directed offshore circulation, producing a series of clockand anticlock-wise cells (longhitano & zanini, 2002), marked by the turbidity plumes of suspended loads debouching from the main rivers, visible in satellite photographs (fig. 3). 4.2 beach types the absence of a wide continental shelf which is characteristic of the ne coast of sicily has deeply influenced the morphology of the relative beach types. narrow beaches are generally found, extending for several kilometres. other types consist of strips of coarse-grained material, constrained between promontories. the average gradient is mediumhigh (up to 9°) and the isobaths of the nearshore zones describe a narrow, rapidly subsiding sea-floor: the bottom deepens regularly to -1000 or -1500 m, without any shelf break (ramp-type shelf). the beach types which are more representative of this coastal domain are described in four main sectors, located from n to s: (i) messina and (ii) taormina, within the peloritani mts coastal subprovince, and (iii) riposto and (iv) ognina (catania), within the mt etna subprovince. fig. 4 (a) view of capo peloro and ganzirri coastline; (b) geological map; (c) profile (modified after bottari et al., 2005). (a) vista panoramica di capo peloro e della costa di ganzirri. (b) schema geologico del settore e relativa sezione (c) (modificata, da bottari et al., 2005). coastal models and beach types ... 108 4.3 peloritani mts subprovince 4.3.1 messina area the messina and capo peloro types are represented by sandy beaches, ne-evolving to a sandy-gravelly spit, which grew during the late holocene transgression due to the action of littoral current circulation (segre et al., 2004). the beaches in the messina area are mainly formed of shingle and sandy types, with morphological configurations directly influenced by the high hydrodynamics of the messina strait. the capo peloro spit-peninsula (fig. 4a) extends from ganzirri to granatari-torre faro, and consists of a highstand lagoon and eolian coastal deposits overlying transgressive marine sand. the latter deposits represent middle pleistocene coastal wedges, prograding during a relative sea-level rise toward the messina strait and eroding lower pleistocene regressive fandelta deposits (messina fm., auct.; fig. 4b). the beach type that summarizes this geological framework shows a wide coastal plain, with a gentle landward inclination. this morphological setting derives from the accommodation space generated by roll-over of the normal-fault hanging-wall, where holocene saltmarsh sedimentation takes place (fig. 4c; bottari et al., 2005). the nearshore beach profile may be considered as the remnant of a beach-barrier system which, strictly controlled by the anthropogenic activity of the last few centuries, has lost its original morphology (fig. 5). the dss parameter calculated for the nearshore profile ranges from 4.1 to 5.2, indicating an intermediate stage between dissipative and reflective domains. this is also shown by the seaward increase in the beach gradient: the nearshore profile evolves from slightly dissipative to reflective type, although dominant wave energy is mitigated by the action of the messina strait tidal currents flowing parallel to the shore (fig. 6). 4.3.2 taormina area the taormina area comprises a number of promontories and islands (fig. 7), amounting to several kilometres of limestone-bordered coastline. this uplifted headland area is located on the relatively downthrown side of a major fault, whose strike corresponds to that of the messina system and which generally bounds the coastline in this area (rust & kershaw, 2000). the shore is represented by cliffs with debris accumulations at the base, without abrasion platforms. when present, the beach is compartmentalized into shingle pocket clast accumulations occurring fig. 5 (a) view from south of capo peloro and ganzirri area; (b, c, d): details of beach types occurring along coast. a) vista meridionale dei settori di capo peloro e ganzirri. (b, c e d) particolari dei modelli di spiaggia osservabili lungo questo litorale. s. longhitano & a. zanini within indentations (spisone, isola bella) and by sandy prograding beaches on the embayments (giardini-naxos, figs. 7a, 7b). the s-directed long-shore seawater circulation is diffracted by the irregular coastline and a series of local clockand anticlock-wise cells develop at local scale. beach sediments are composed of metamorphic and calcareous clasts, up to 30 mm in size, organized into a 5°-7° seaward-inclined narrow strip. along the shingle beach, relicts of ancient beachrock deposits formed of gently seaward-inclined conglomeratic beds occur, referable to a recent uplifted beach face (fig. 8). the beach for this sector can be described as a reflective-type profile, characterized by a staircase-type section (submerged data are from antonioli et al., 2003), with a dss rating of 0.8 (fig. 9). a sector which well represents the degree of morphological variability typical of this coastal subprovince is the area of giardini-naxos. located a few kilometers south of taormina, two promontories, the calcareous capo taormina (north) and the volcanic capo schisò (south) form a wide gulf (see fig. 6a). this particular morphology causes local seawater circulation which has given rise to a broad sandy shoal, during the last 5-6000 years (randazzo, 2003). this morphological setting locally changes the hydrodynamic framework of this part of the subprovince, from a reflective to a local dissipative (dss = 1.7) nearshore profile (fig. 8d). 109 fig. 6 beach type and nearshore profile of capo peloro/messina area. original morphology of previous beach-barrier system profoundly modified by anthropogenic activity along coast in last few centuries. (ω = dean’s surf scaling parameter; ws = mean sediment fall velocity; hb = mean breaker height; t = mean breaker period). modello di spiaggia schematico e profilo sotto costa relative al settore di capo peloro/messina. si noti come l’originale assetto morfologico di un sistema di tipo barra è stato profondamente modificato dall’azione antropica lungo costa degli ultimi secoli. fig. 7 (a) view of taormina and giardini naxos coastline; (b) geological map; (c) profile (modified after lentini et al., 2000). (a) vista panoramica delle aree di taormina e giardini naxos. (b) schema e relativo profilo geologico (c) (modificato, da lentini et al., 2000). coastal models and beach types ... 4.4 mt etna subprovince 4.4.1 local coastal hydrodynamics the eastern flank of mt etna has a typical morphology that reflects the progressive emplacement of historic and recent lava flows, due to effusive volcanic activity, reaching the sea and creating a peculiar coastal setting (monaco et al., 1997). here, currents driven by the messina strait also influence local seawater circulation, producing longshore s-directed and local n-directed currents. nearshore circulation is often diffracted and inhibited by the great complexity of the cliffed volcanic shoreline, marked by a number of small coastal promontories and indentations, created by eroding lava deltas. in this subprovince, only wave energy may be considered as a dominant factor affecting the shoreline and controlling beach sediment re-working. waves approach the coast obliquely, as a result of the s-directed currents. 4.5 riposto area the main tectonic and morphologic feature of 110 fig. 8 (a) panoramic view of taormina cliff, showing marine notch 5 m above present sea level; (b) isola bella promontory, connected at the coast to a gravel spit; (c) detail of shingle beach type, a few km n of previous photos; (d) beach type at giardini naxos. (a) veduta panoramica della falesia di taormina, mostrante un chiaro solco d’erosione marina posto ad un’altezza di circa 5 metri sull’attuale livello del mare. (b) il promontorio dell’isola bella, collegato alla linea di costa attraverso un sottile tombolo ghiaioso. (c) dettaglio della spiaggia ghiaiosa di spisone, pochi km a nord delle precedenti foto. (d) spiaggia sabbiosa di giardini naxos. fig. 9 beach type characterizing coastline of taormina area. a shingle, narrow beach is confined to inner part of a steep, dissipative-to-reflective nearshore profile. (ω = dean’s surf scaling parameter; ws = mean sediment fall velocity; hb = mean breaker height; t = mean breaker period). modello di spiaggia relativo alla costa taorminese. l’unica spiaggia ghiaiosa di piccole dimensioni che può svilupparsi appare chiaramente confinata nel settore più interno di un profilo di tipo dissipativo/riflessivo. s. longhitano & a. zanini eastern mt etna is the widespread nnwand nne-trending active fault system. the nnwsse-oriented timpe fault system is considered to be the inland extension of the malta escarpment (cristofolini et al., 1979; lentini, 1982). here, a coarse-grained fan-delta deposit occurs extensively (figs. 10a, 10b). the socalled ‘chiancone’ (kieffer, 1969; 1970; romano & sturiale, 1981; di grande & di maggio, 1988) represents the largest etnean volcanoclastic sequence (del negro & napoli, 2002). some authors (e.g., calvari & groppelli 1996; bousquet et al., 1998) have pointed out that this fan-shaped deposit has a submerged counterpart toward the ionian, which modifies the isobathic trend of this coastal sector (fig. 10c). the beach type is characterized by monogenic volcanic clasts, with the largest grain size observed along the whole ionian coast of sicily (fig. 11). during high-energy stages, waves rework the clasts along the swash zone, producing very impressive noise and vibration, perceptible quite far from the beach. beach morphology here is directly influenced by the size of the clasts, organized into three orders of berms and characterized by a seaward gradient of up to 10° (fig. 12). the dss parameter indicates a fully reflective nearshore profile, controlled by oblique wave incidence. according to monaco et al. (1997), the beach of this sector developed on the foot-wall of a normal fault. instead, our observations indicate that it represents sediments which accumulated during the end of the last sea-level rise, occupying the erosional platform caused by the sea during the present sea-level highstand. 4.6 ognina the youngest normal faults of the mt etna area are located along the base of the eastern flank of the volcano. nnwand nne-trending fault segments control the present coastal morphology, producing steep late pleistocene-holocene sea cliffs (monaco et al., 1997). the most impressive scarps extend for about 20 km from acireale to s. alfio, producing walls up to 120 m high (fig. 13a). the terrains forming this cliffed coast are made up of lava flows from eruptions of different ages (romano & sturiale, 1982) (fig. 13b). the coastal morphology is characterized by sea terraces, occupied by holocene alluvial volcanoclastic deposits (fig. 13c). the beach types considered most representative of the southern sector of this subprovince were studied n of catania, along the shoreline of ognina. here, anthropogenic activity is recent and less invasive, and the morphological characters of this coast are still well-preserved (fig. 14). the beach type is represented here by small pocket beaches, containing coarse-grained volcanic sediments, deriving only from rock-fall debris of the cliffs, attacked and eroded by the powerful action of 111 fig. 10 (a) view of the riposto and praiola coastline; (b) geological map; (c) profile (modified after del negro and napoli, 2002). (a) vista panoramica del settore costiero di riposto e praiola. (b) schema e profilo geologico del settore (c) (modificato, da del negro e napoli, 2002). coastal models and beach types ... waves. the nearshore profile reflects the morphology of a submerged lava delta front, characterized by a staircase-type sea-bottom which creates a very high reflective-type hydrodynamic setting (dss parameter 0.003) (fig. 15). 5. discussion and conclusions the subdivision of discrete segments of shoreline, based on the geological framework in which they developed in recent times, identifies the characters of the beach types in a more analytical way. the morphology 112 fig. 11 (a) cliff along praiola beach; (b) detail of same beach characterized by a series of storm berms; (c) volcanic cobbles and pebbles along swash zone; (d) detail of clast morphology. a) falesia vulcanoclastica lungo la spiaggia di praiola. (b) dettaglio della stessa spiaggia, caratterizzata da una serie di berme generate da episodi di tempesta. (c) clasti vulcanici lungo la zona di battigia. (d) dettaglio morfometrico dei clasti vulcanici. fig. 12 beach type of riposto/praiola site. nearshore profile is reflective, slightly dissipative. beach develops near a cliff cut due to present sea-level highstand. (ω = dean’s surf scaling parameter; ws = mean sediment fall velocity; hb = mean breaker height; t = mean breaker period). modello relativo alla spiaggia di riposto/praiola. il profilo sotto costa è di tipo riflessivo, leggermente dissipativo. la spiaggia si sviluppa occupando il solco erosivo formatosi durante l’attuale stazionamento alto del livello del mare. s. longhitano & a. zanini and sedimentology of each single coastal segment directly refer to a series of geological considerations, giving a complete framework of the coastal system. morphological and sedimentological observations collected from the sites of capo peloro-messina, taormina-giardini naxos, riposto and ognina-catania, in the northern coastal province of the ionian coast of sicily, describe a series of beach types which directly reflect the local geological framework. the present-day aspect of these beaches indicates by longmediumand short-term processes, the duration of which depended on the time over which they developed within the system. the general morphology of a coastal compartment influences beach characters in terms of longitudinal/lateral extension of sediments, prograding rate, and wave influence on long-shore sediment distribution. all these elements are long-term features, directly influencing the local geology. in contrast, a series of several different features may be appreciated in beaches, where short-term control processes are active. for example, beach gradient and the physical organization of sediments along the beachface are parameters which depend on grain size and recent hydrodynamics which, in turn, derive from local meteomarine conditions. an exception to these considerations is the coastal uplift rate, especially when recent vertical movements are very rapid. the examples observed in the ne coastal province of the ionian sicilian shoreline show several coastal compartments characterized by high uplift rates. the time-span over which vertical coastal movements have been calculated (125÷5 ka) and their influence on coastal morphology are considered as medium-term controlling factors for the development of a coastal sector. the beach types developing along uplifting coasts are regarded as the variables of a coastal system which best record this condition. the hydrodynamic identity of each study site, quantified by dean’s surf scaling (dss) parameter, characterizes the dynamic behavior of every beach and its relative nearshore zones. the results are transitional between dissipative, slightly dissipative, and reflective nearshore profiles, depending not only on the parameters included in the calculation (sediment grain size, mean breaker height and length, etc.) but also on the coastal gradient of the bedrock on which the beach developed during recent times. the gradient of the bedrock is strongly controlled by vertical tectonic coastal movements, which are expressed in coastal uplift rates. assuming this background, every beach profile, 113 fig. 13 (a) view of ognina and catania volcanic coastline; (b) geological map; (c) profile (modified after monaco et al., 2000). (a) vista panoramica relative al settore costiero di ognina e catania. (b) schema e profilo geologico del settore (c) (modificato, da monaco et al., 2000). coastal models and beach types ... 114 fig. 14 (a) panoramic view of ognina coastline (from south), typically characterized by lava deltas of historic etnean eruptions; (b) view of same coast (from north) where pocket beaches composed of volcanoclastic detritus occur; (c) detail of columnar, basaltic cliff; (d) pocket beach at toe of cliff in previous photo. (a) veduta panoramica meridionale del settore costiero di ognina, caratterizzata da spandimenti lavici appartenenti alle eruzioni storiche dell’etna. (b) veduta settentrionale del medesimo tratto costiero, dove si sviluppano alcune isolate pocket beach costituite da clasti esclusivamente di natura basaltica. (c) dettaglio dei basalti colonnari che costituiscono una parte della falesia vulcanica. (d). dettaglio di una pocket beach presente alla base della falesia ritratta nella foto precedente. fig. 15 beach type of ognina/ catania site. beach occurs at toe of a basaltic cliff, created by erosive action of waves. beach sediment derives only from debris produced by wave erosion. reflective type of nearshore profi le implies highenergy hydrodynamics and temporal suspension of coarse clasts during storms. (ω = dean’s surf scaling parameter; ws = mean sediment fal l velocity; hb = mean breaker height; t = mean breaker period). modello di spiaggia relativo al settore di ognina/catania. i clasti basaltici si attestano alla base della falesia lavica prodotta dall’azione meccanica dell’erosione del moto ondoso. il sedimento deriva esclusivamente dal crollo di porzioni della parete vulcanica. il comportamento idrodinamico di tipo riflessivo del profilo sotto costa determina la temporanea sospensione di clasti anche di grandi dimensioni durante le fasi di alta energia. s. longhitano & a. zanini with its morphological, sedimentological and hydrodynamic features, may be referred to the local coastal uplift rate. fig. 16 displays the gradient and grain-size of nearshore profiles on the y-axis, and the relative distance along the ionian coast of sicily on the x-axis. the first parameter (range: 1÷5) indicates the gradient of the nearshore profile and the sediment grain-size for each single site of observation. as these two characteristics vary in the same way, as gradient and sediment grain-size increase, index values vary progressively from 1 to 5. the uplift rates on the righthand y-axis define discriminated classes of uplfiting coasts. all these combined parameters show a normal correlation with a gradual transition between dissipative and reflective beach types. the continental shelf progressively spreads eastward from northern to southern coastal subprovinces (fig. 16) and shows two main groups of beach types. the first group corresponds to the models of the northern sector, where the continental shelf progressively thins northwards and the beach types show wide, dissipative-type, sandy inshore profiles, characterized landwards by well-developed alluvial plains. the beach gradients observed at capo peloro, messina and letojanni are medium-low, and uplift rates of up to 0.8 mm a-1. the second group contains taormina, riposto and ognina, where the continental shelf widens southwards, and the beach types are narrow, coarse-grained and cliffed with a medium-high gradient and uplift rates of up to 2.4 mm a-1. thus, the ionian coastal province of ne sicily shows beach types with morphology mainly influenced by local uplift rates, rather than by continental shelf width. another way of describing the beach types occurring in the studied subprovinces is shown in fig. 17. this block-diagram has a series of differing coastal profiles and models, taking each beach type into account: ( i ) bedrock lithology; (ii) the nature of the feeder system of a given shoreline; (iii) local uplift rates. in the model of fig. 17, where beach types are displayed in no geographic order, as uplift rates increase (ranging from 0.7 to 2.4 mm a-1), the feeder systems evolve from wide, well-developed, alluvial braided plains (letojanni), to torrential-type coarse-grained 115 fig. 17 some coastal profiles and models occurring along study coastline and related to changes in uplift rates. in this type of correlation, wave energy, sea-bottom gradient and beach sediment grain-size correspond directly to various classes of coastal vertical movements. diagramma che mostra alcuni differenti modelli costieri sono stati individuati lungo litorale studiato, in funzione della variazione dei tassi di sollevamento. in questo tipo di correlazione, l’energia del moto ondoso, il gradiente del fondale sotto costa e il diametro medio dei sedimenti corrispondono a differenti classi di movimenti verticali della costa. fig. 16 correlation between sediment grain-size and gradient of each nearshore system (studied here) (left-hand y-axis), with local coastal uplift rates (right-hand y-axis), with relative distances of study sites (lower x-axis). note progressive changes in hydrodynamic behavior of each profile from ‘dissipative’ to ‘reflective’ as uplift rate increases. progressive, southward enlargement of continental shelf does not correlate with gradient of inshore profile. diagramma mostrante la correlazione tra diametro dei sedimenti e gradiente di ciascun sistema di spiaggia considerato nel presente studio (asse di sinistra delle ordinate) con i locali tassi di sollevamento (asse di destra delle ordinate), riferiti alle rispettive distanze (relative e cumulative) che separano le diverse aree studiate (asse delle ascisse). si noti una progressiva variazione nel comportamento idrodinamico di ciascun singolo profilo da ‘dissipativo’ a ‘riflessivo’ all’aumentare della velocità del tasso di sollevamento locale. la progressiva espansione verso meridione della piattaforma continentale sembra non correlarsi direttamente con questa caratteristica. coastal models and beach types ... meandering streams (messina and giardini naxos) and then to alluvial fans (riposto), directly influencing the beaches. the vertical tectonic movements affecting the coastal bedrock strongly influence the sedimentation style of the supply systems and the morphology of the beach types which develop here show no influence of continental shelf morphology. correlations between the morphology and sedimentology of a beach type and the local uplift rate may thus represent a useful tool in discriminating behavior, and may perhaps be applied to other similar coastal systems. however, the model is hypothetical and needs to be verified by means of a wider range of case studies, like those represented by the beaches in the central-southern part of the ionian coast of sicily. acknowledgments we are grateful to prof. mario grasso (university of catania) and an anonymous referee for their useful and productive review of the manuscript. financial support for this study was provided by the ministero dell’università, grant 60% (a. zanini). references allen j.r.l., 1982 sedimentary structures: their character and physical basis. vol. i, elsevier scientific publishing company, new york, pp. 593. amodio morelli l., bonardi g., colonna v., dietrich d., giunta g., ippolito f., liguori v., lorenzoni s., paglionico a., perrone v., piccarreta g., russo m., scandone p., zanettin lorenzoni e., zuppetta a., 1976 l’arco calabro–peloritano nell’orogene appenninico–maghrebide. memorie della società geologica italiana, 17, 1-60. amore c., d’alessandro l., giuffrida e., lo giudice a., g., zanini a., 1992 dinamica litorale tra capo peloro e capo passero (sicilia orientale). boll. acc. gioienia sci. nat., 25, 339, 69-114. amore c., d’alessandro l., giuffrida e., lo giudice a., randazzo g., zanini a., 1990 first data about shoreline evolution along the coasts of eastern sicily. littoral ’90, eurocoast marseilles, 284292. amore c., gandolfi g., giuffrida e., paganelli l., zanini a., 1979 caratteristiche morfologiche, tessiturali e composizionali del litorale del golfo di catania. miner. petrogr. acta, 23, 47-75. antonioli f., ferranti l., lambeck k., kershaw s., verrubbi v., dai pra g., 2006 late pleistocene to holocene record of changing uplift rates in southern calabria and northeastern sicily (southern italy, central mediterranean sea). tectonophysics 422, 23-40. antonioli f., cremona g., immordino f., puglisi c., romagnoli c., silenzi s., valpreda e., verrubbi v., 2002 new data on the holocenic sea level rise in nw sicily. global and planetary change 34, 121–140. antonioli f., dai pra g., segre a.g., sylos labini s., 2004a new data on late holocene uplift rates in the messina area, italy. quaternaria nova, viii, 4567. antonioli f., lambeck k., kershaw s., rust d., sylos labini s., segre a.g., verrubbi v., belluomini g., dai pra g., ferranti l., improta s., vesica p., 2004b evidence for non-uniform uplift rates in southern italy (calabria and eastern sicily) on glacial-cycle timescales. quaternaria nova, viii, 187192. antonioli f., kershaw s., rust d., verrubbi v., 2003 holocene sea-level change in sicily, and its implications for tectonic models: new data from the taormina area, ne sicily. marine geology 196, 53–71. bonfiglio l., violanti l., 1983 prima segnalazione di tirreniano ed evoluzione pleistocenica del capo peloro (sicilia nord-orientale). geogr. fis. din. quat. 6, 3-15. bordoni p., valensise g., 1998 deformation of the 125 ka marine terrace in italy: tectonic implications. in: stewart, i.s., vita-finzi, c. (eds.). coastal tectonics, geological society special publications, 146. geological society, london, pp. 71–110. bottari a., bottari c., carveni p., giacobbe s., spano n., 2005 genesis and geomorphologic and ecological evolution of the ganzirri salt marsh (messina, italy). quaternary international 140-141, 150–158. bousquet j.c., gabbianelli g., lanzafame g., sartoiri r., 1998 evolution volcanotectonique de l’etna (sicilie): nouvelles donées de géologie marine et terrestre. rapp. commiss. int. pour l’explor. sci. de la mer méditerr. 35, 56-57. calvari s., groppelli g., 1996 relevance of the chiancone volcaniclastic deposit in the recent history of etna volcano (italy). j. volcanol. geotherm. res. 72, 239-258. cristofolini r., lentini f., patanè g., rasà r., 1979 integrazione di dati geologici, geofisici e petrologici per la stesura di un profilo crostale in corrispondenza dell’etna. boll. soc. geol. it. 98, 239-247. de domenico e., 1987 caratteristiche fisiche e chimiche delle acque nello stretto di messina. in: le détroit de messine (italie). evolution tectono-sédimentaire récente (pliocène et quaternaire) et environnement actuel. in p. barrier, i. di geronimo and montenat c., eds.. doc. et trav. igal, paris, 11, 272 p. dean r. g., 1991 equilibrium beach profiles: characteristics and applications. journal of coastal research, 7, 53-84. del negro c., napoli r., 2002 ground and marine magnetic surveys of the lower eastern flank of etna volcano (italy). journal of volcanology and geothermal research 114, 357-372. di geronimo i., 1990 relation entre biocénoses et pollution dans la baie d'augusta (sicile orientale). map technical reports. ser. 40, pp. 83-115, f.a.o. unep, athens. di grande a., di maggio f., 1988 lineamenti geologici dell’area del ‘chiancone’ (etna). boll. acc. gioenia sci. nat. 21 (334), 399-416. di grande a., neri m., 1988 tirreniano a strombus bubonius a m. tauro (augusta siracusa). rend. 116 s. longhitano & a. zanini soc. geol. ital. 11, 57-58. di stefano a., lentini f., 1995 ricostruzione stratigrafica e significato paleotettonico dei depositi pliopleistocenici del margine tirrenico tra villafranca tirrena e faro (sicilia nord-orientale). studi geologici camerti, volume speciale 2, 219-237. ferretti o., delbono i., furia s., barsanti m., 2003 elementi di gestione costiera (parte i). tipi morfosedimentologici dei litorali italiani. enea, pp. 43. finkl c.w., 2004 coastal classification: systematic approaches to consider in the development of a comprehensive scheme. journal of coastal research 20, 1, 166-213. firth c., stewart i., mcguire w.m., kershaw s., vitafinzi c., 1996 coastal elevation changes in eastern sicily: implications for volcano instability at mount etna. in: mcguire, w.m., jones, a.p., neuberg, j. (eds.). volcano instability on the earth and other planets, geological society special publication geological society, london, pp. 153–167. gvirtzman z., nur a., 1999a plate detachment, asthenosphere upwelling, and topography across subduction zones. geology 27, 563–566. gvirtzman z., nur a., 1999b the formation of mount etna as the consequence of slab rollback. nature 401, 782–785. kershaw s., 2000 quaternary reefs of northeastern sicily: structure and growth controls in an unstable tectonic setting. j. coast. res. 16, 1037-1062. kershaw s., antonioli f., 2004 tidal notches at taormina, east sicily: why is the mid-holocene notch well-formed, but no modern notch is present in the same locality? quaternaria nova, viii, 155-169. kieffer g., 1969 origine explosive de la valle del bove (etna, sicilie). c. r. acad. sci. paris 269, 19381941. kieffer g., 1970 les dépots detritiques et pyroclastiques du versant oriental de l’etna. atti acc. gioenia sci. nat. ser. viii, 2, 131-160. lanzafame g., neri m., rust d., 1996 active tectonics affecting the eastern flank of mount etna: structural interactions at a regional and local scale. in: gravestock, p.j., mcguire, w.j. (eds.), etna: fifteen years on. centre for volcanic studies, cheltenham and gloucester college of higher education, pp. 25–33. lentini f., 1982 the geology of the mt. etna basement. mem. soc. geol. it. 23, 7-25. lentini f., carbone s., catalano s., di stefano a., gargano c., romeo m., strazzulla s., vinci g., 1995 sedimentary evolution of basins in mobile belts: examples from tertiary terrigenous sequences of the peloritani mts (ne sicily). terra nova, 7(2), 161-170. lentini f., catalano s., carbone s., 2000 carta geologica della provincia di messina (sicilia nord-orientale), scala 1:50.000, s.el.ca. firenze. longhitano s., colella, a., 2007 geomorphology, sedimentology and recent evolution of the anthropogenically modified simeto river delta system (eastern sicily, italy). sedimentary geology. (in press). longhitano s., zanini a., 2002 sedimentary features and morphological prediction for the modern simeto river delta (eastern sicily). the changing coast. 3, 245-252. longhitano s., zanini a., 2005 holocene coastal systems of eastern sicily and their relationship with the onshore geology. proceedings of the geosed annual meeting, spoleto, september 2005. longhitano s., zanini a., 2006 primi dati sui differenti modelli di spiaggia della costa nord-orientale della sicilia in relazione all’assetto geologico strutturale. atti del congresso aiqua, roma, 52-53. miyauchi, t., dai pra, g., sylos labini, s., 1994 geochronology of pleistocene marine terraces and regional tectonics in tyrrhenian coast of south calabria, italy. il quaternario 7, 17–34. monaco c., antonioli f., de guidi g., lambeck k., tortorici l., verrubbi v., 2004 tectonic uplift and sea-level change during the holocene in the catania plain (eastern sicily). quaternaria nova, 8, 171-185. monaco c., catalano s., de guidi g., gresta s., langer h., tortorici l., 2000 the geological map of the urban area of catania (eastern sicily): morphotectonic and seismotectonic implications. mem. soc. geol. ital. 55, 425-438. monaco c., tapponier p., tortorici l., gillot p.y., 1997 late quaternary slip rates on the acirealepiedimonte normal faults and tectonic origin of mt. etna (sicily). earth and planetary science letters 147, 125–139. montenat c., barrier p., di geronimo i., 1987 the strait of messina, past and present: a review. in: le détroit de messine (italie). evolution tectonosédimentaire récente (pliocène et quaternaiie) et environnement actuel, (p. barrier, i. di geronimo and montenat c., eds.). doc. et trav. igal, paris, 11, 272 p. randazzo g., 2003 giardini naxos-isle of sicily (italy) in eurosion project. pp.1-16. romano r., sturiale c., 1981 geologia del versante sudorientale etneo. f. 270 iv (no, ne, so, se). boll. soc. geol. it. 100, 15-40. romano r., sturiale c., 1982 the historical eruption of mt etna (volcanological data). mem. soc. geol. ital., 23, 75-97. rust d., kershaw s., 2000 holocene tectonic uplift patterns in northeastern sicily: evidence from marine notches in coastal outcrops. marine geology 167, 105-126. segre a. g., bagnaia r., sylos labini s., 2004 holocene evolution of the pelorus headland, sicily. quaternaria nova, viii, 69-78. stewart i.s., cundy a., kershaw s., firth c., 1997 holocene coastal uplift in the taormina area, northeastern sicily: implications for the southern prolongation of the calabrian seismogenic belt. journal of geodynamics 24, 37–50. 117 ms. ricevuto il 31 maggio 2006 testo definitivo ricevuto il 3 ottobre 2006 ms. received: may 31, 2006 final text received: october 3, 2006 coastal models and beach types ... (antonioli et al., 2006; ferranti et al., 2007; pavano et al., 2016). along the northern margin, well-developed terrace flights show a clear eastward increase in uplift from the low-strain western sector into the actively rising peloritani region (antonioli et al., 2006; ferranti et al., 2007; pavano et al., 2016; di maggio et al., 2017; parrino et al., 2023). by contrast, much of the southern coastline preserves no clear mis 5e markers, likely reflecting limited accommodation space, erosion, and poor preservation potential (d’angelo & vernuccio, 1996; antonioli et al., 2006; ferranti et al., 2006). much of this regional work has focused on mis 5e terrace surfaces, often recognised either near their quasi -eustatic reference elevation of ~5-6 m in tectonically stable mediterranean settings, or at significantly uplifted positions along the sicilian margin, ranging from ~2-14 m in the northwest to >100 m in the rapidly rising northeastern sector (antonioli et al., 2006, 2025; ferranti et al., 2006, 2007; sulli et al., 2013; parrino et al., 2023). in several areas these surfaces are also identified by the warm-water marker fossil thetystrombus latus (gmelin, 1791) (=strombus bubonius lamarck, 1822). the distribution of this fossil, however, is highly uneven and notably absent along the southwestern coast, leaving terrace available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 38 (2), 2025, 119-131 https://doi.org/10.26382/amq.2025.07 1. introduction marine terraces along coastlines are key archives of quaternary landscape evolution. they preserve signals of glacio-eustatic sea-level fluctuations modulated by regional uplift and crustal deformation (bull, 1984; dumas et al., 2005; malatesta et al., 2022). nowhere is this more evident than in the central mediterranean, specifically along the sicilian margin, where terrace sequences record the combined imprint of climatic oscillations and the structural dynamics of the sicilian fold and thrust belt (sftb). these landforms offer critical constraints on rates of uplift, sedimentary response to sea-level highstands, and coastal evolution through the middle and late pleistocene (antonioli et al., 2006, 2025; ferranti et al., 2006, 2007, 2021; di maggio et al., 2017; pavano et al., 2016; parrino et al., 2022, 2023; agate et al., 2025). across sicily, the marine terrace records are far from uniform. the sicilian region spans multiple tectonic domains, and coastal uplift patterns change markedly along strike. in northeastern sicily, mis 5e terraces rise to more than +100 m, reflecting rapid vertical motions of the calabrian forearc above the subducting ionian slab unravelling late quaternary coastal evolution through a multidisciplinary approach: a case study from southwestern sicily (italy) eshaan srivastava1, nicolò parrino2, alessandro bonfardeci1, mauro agate1, francesco caldareri1, maurizio gasparo morticelli1, pierfrancesco burrato2, andrea moscariello3, mitthu dhali4, javed n. malik4, attilio sulli1 1dipartimento di scienze della terra e del mare, university of palermo, palermo, italy. 2istituto nazionale di geofisica e vulcanologia, rome, italy. 3department of earth sciences, university of genève, genève, switzerland. 4department of earth sciences, indian institute of technology, kanpur, india. corresponding author: alessandro bonfardeci <alessandro.bonfardeci@unipa.it> abstract: we present new lithostratigraphic, micropaleontological, and chronological evidence for the late quaternary evolution of the carboj river mouth along the southwestern sicilian coastline. field mapping, micropaleontological analysis, and luminescence dating reveal a narrow, elevated coastal landform, the maragani relief, capped by a flat surface underlined by marine sands dated to ~77 ka (mis 5a). this surface, perched at ~55 m a.s.l., overlies the early pleistocene agrigento formation, assigned to the middle calabrian, establishing a vertical stratigraphy spanning nearly one and half million years. unlike the classic stepped terraces typical of the region, the maragani relief lacks fluvial incision and shows no evidence of marine abrasion. instead, its geometry, lithology, and tectonic context support interpretation as a relict wave-built mouth bar formed during a sealevel stillstand and later uplifted by regional deformation associated with the sicilian fold and thrust belt. this study shows that even single localized coastal features can capture the combined effects of tectonic uplift and sea-level change. by focusing on the maragani relief, we highlight how site-specific landforms, often overlooked, can offer valuable insight into quaternary landscape evolution along the mediterranean margins. keywords: coastal landscape; lithostratigraphy; micropaleontology; luminescence dating; central mediterranean. mailto:alessandro.bonfardeci@unipa.it chronologies in this sector historically less certain. within this broader framework, the southwestern margin remained poorly constrained until the work of ferranti et al. (2021), who provided the first integrated mapping and luminescence ages for marine terraces spanning mis 7 to mis 5. their study showed that uplift in the menfi-selinunte-sciacca sector reflects both a long-wavelength regional signal and shorter-wavelength deformation linked to active fold growth along the buried front of the sftb. this work established the first quantitative terrace chronology for the area and clarified the structural controls on coastal emergence. as these sicily-wide and regional frameworks have become better defined, new questions have emerged at 120 srivastava e. et al. fig. 1 (a) geological map of the carboj river mouth region showing lithostratigraphic units, mapped tectonic structures, terrace inner margins, trace of the section (see fig. 2) and sample locations. the stratigraphy includes early pleistocene deep-marine marls of the agrigento fm. (agga), overlain by marine terrace deposits (gn5 to gn7), alluvial terraces deposits (bn1, bn5), transitional (g1), alluvial (ba1), and continental (a1, af1, ec1) units. outcrop locations are marked in red (agga) and blue (gn5), with s1 and s2 indicating the precise sampling points discussed in figures 4 and 5. dashed coloured lines trace the inner margins of stepped marine terraces (t2-t6), interpreted as mis 5c to 7c features (modified from ferranti et al., 2021). black dashed contour lines (50 and 100 m a.s.l.) highlight the topography of the maragani relief and surrounding landscape. (b) tectonic overview map of southern sicily, showing the main structural domains, including the sicilian fold and thrust belt (sftb), gela foredeep, and iblean and pelagian forelands. the study area is indicated by the red box. (c) location of the study area within the central mediterranean sea (modified from google earth). pleistocene (calabrian) agrigento formation (agg; fig. 1a), a syn-tectonic regressive succession consisting of marly sands, sandy to silty clays (agga), biocalcarenites, and biocalcirudites (aggc) (catalano et al., 1998; gasparo morticelli et al., 2015; montana et al., 2024; pucci et al., 2023; sulli et al., 2024). the agg deposits unconformably overlie deformed meso-cenozoic bedrock and related miocenepliocene syn-tectonic covers, reaching thicknesses of over 500 meters (fig. 2) in the western part of the study area (sulli et al., 2024). moreover, even after the agrigento formation was deposited, this region was still affected by a compressive tectonic regime, which caused the folding of the succession after the calabrian age, as evidenced by the presence of the capo s. marco anticline (fig.s 1a, 2; sulli et al., 2024). marine terrace deposits, mapped as gn5 and gn7 in figure 1, unconformably lie on the agga unit. they consist of sands and calcareous arenites and conglomerates, occasionally rich in rhodoliths and displaying shallow marine facies. their elevations and morphologies correspond to established sea-level highstands during mis 5 and mis 7. above these marine units, two main types of surficial deposits are present. the fluvial terrace deposits (bn) comprise unconsolidated yellow-brown silty sands grading into poorly sorted, clast-supported conglomerates with rounded carbonate clasts (fig. 2). these deposits typically occur between 35 and 70 m a.s.l. (fig.s 1a, 2). overlying and surrounding them, the transitional and continental covers include valley-floor alluvium (ba1), slope debris and landslide deposits (af1, a1), eluvial-colluvial sediments (ec1), and beach deposits (g1). these units are widespread and often discontinuous, blanketing terrace surfaces and valley margins (fig.s 1a, 2). the maragani relief, positioned between the capo san marco plateau and the carboj river mouth, fits into this stratigraphic framework. it is underlain by the agga and mantled by middle-late pleistocene deposits, integrating it structurally and stratigraphically into the broader terrace system. the geological crosssection a-b and the relative lithostratigraphic column, finer spatial scales. one such question arises from fieldbased observations at the mouth of the carboj river, where we identified a distinctive landform, the maragani relief (fig. 1), that diverges from the stepped marineterrace pattern typical of the region. this narrow, elongated surface extends parallel to the coastline but is oriented perpendicular to the carboj river mouth, a configuration not observed at adjacent, larger river systems. its isolated expression, lack of upstream incision, and capping of marine sands suggest it is not the result of fluvial erosion or classic marine abrasion. this makes the maragani relief a compelling case study for examining how sedimentary, hydrodynamic, and tectonic processes can interact in complex, site-specific ways that diverge from regional terrace models. by zooming in on this particular landform and applying a multiproxy approach that integrates lithostratigraphy, micropalaeontology, and luminescence dating, we aim to show how landscape evolution in tectonically active settings is not only regionally coherent but also locally complex when examined at finer resolution. in doing so, we place the maragani relief within the broader context of late quaternary coastal uplift in southwestern sicily and refine the link between terrace formation, stratigraphic architecture, and active structures along the sftb front. 2. geological setting the study area is located along the southwestern coast of sicily, within the foreland domain of the sftb. according to regional physiographic mapping (amadei et al., 2000), the landscape transitions from “terrigenous hill landscape with plateaus” in the west to “heterogeneous hill landscape with plateaus” toward the east. this variation reflects the lithological complexity and structural heterogeneity of the region, shaped by neogene compressional tectonics and overprinted by quaternary coastal processes. thoe castal segment between capo san marco and the carboj river mouth (fig. 1) exposes a wellpreserved suite of middle-late pleistocene marine and continental deposits. marine terraces, ranging in elevation from ~50 to 105 m a.s.l., are carved into the early 121 relict bar at the carboj river mouth, south-western sicily fig. 2 composite lithostratigraphic column shown on the left illustrates the composition and the geometric relationship between the different outcropping units, as well as their average thickness. on the right, the geological cross-section a-b (modified from sulli et al., 2024) is shown (trace in figure 1a). as regards the a-b section, the undifferentiated bedrock includes the deformed meso-cenozoic units of the saccense domain and the overlying middle miocene to pliocene syn-tectonic deposits (sulli et al., 2024). illustrate the stratigraphic architecture across the study area and highlights the persistence of agg as the underlying unit beneath both marine and continental sequences (fig. 2). 3. materials and methods 3.1. field mapping geological mapping and field observations were conducted between 2021 and 2024 under the framework of the italian national geological mapping initiative (carg project, sheet 628 “sciacca”; sulli et al., 2024). the survey focused on the capo san marcocarboj river sector, with special attention to the maragani relief and adjacent terraces. terrace surfaces were mapped using high-resolution topographic data and field -verified through stratigraphic logging and lithofacies description. the underlying stratigraphy, including the early pleistocene agrigento formation (agga), was traced across multiple outcrops and logged in detail to distinguish marine (mis 5 and mis 7) and continental facies, as well as to characterize the stratigraphic boundaries. 3.2. lithostratigraphy stratigraphic successions were identified through field analyses, by observing well-exposed outcrops and documenting facies information, thickness, stratal pattern, bedding attitudes, and detailed logs were subsequently obtained. moreover, stratigraphic relationships between the different units and various boundary types were also examined to produce detailed lithostratigraphic logs (nichols, 2009; miall, 2022). direct macroscopic observations of the grain size and distribution, mineralogical content, and fossiliferous content, served to obtain crucial compositional and granulometric data. additionally, two sediment samples, labelled as s1 and s2, were collected and then subjected to laboratory processing and analysis. granulometric analyses were conducted on these samples to estimate the dimensional distribution of the analysed sediments. thereafter, by using a reflected-light optical microscope we determined the compositional features of the sediments (besler, 2008). 3.3. micropaleontological analysis one of the two collected samples (s1) was treated in the laboratory to study the micropaleontological content. in particular, a portion of this sample of about 80100 g was oven-dried, disaggregated in a dilute solution of 10% hydrogen peroxide (h2o2) for about 24 h, and then washed using a 63 µm mesh sieve (ayyad et al., 2025). the residue was then oven-dried at about 50-60 °c and weighed to obtain an estimate of its particle size distribution. qualitative analysis of the planktonic and benthic foraminiferal assemblages was conducted on the size fraction greater than 125 µm of the residue (caruso, 2004; sabbatini et al., 2014; bonfardeci et al., 2018; ferraro et al., 2024). the biostratigraphic and chronostratigraphic assumptions were based on planktonic foraminiferal taxa, adopting the most recent biozonal scheme for the mediterranean sea (lirer et al., 2019). 3.4. luminescence dating to establish a chronostratigraphic marker for the maragani relief, we collected a single optical stimulated luminescence (osl) sample (s2-osl) from a sandy horizon capping the surface. the sample preparation was carried out under low-intensity red light in the osl/ tl laboratory of the department of earth sciences, iit kanpur. the outermost 3 cm of each sample was used to assess moisture content and calculate dose rates, while the inner, light-protected portion was used to determine equivalent doses (de). this inner material was sieved to isolate grains between 90 and 212 μm, then treated with 32% hydrochloric acid (hcl) to remove carbonates, followed by 30% hydrogen peroxide (h2o2) to eliminate organic matter. to prevent particle clumping, 0.01 n sodium oxalate (na2c2o4) was added. finegrained polymineral fractions (4-11 μm) were isolated by settling based on stokes' law (wintle, 2008; mahan et al., 2023; malik et al., 2024; sharma et al., 2024; srivastava et al., 2025). for de measurement, continuous-wave osl was recorded using a risø tl/osl reader equipped with blue (470 nm) and infrared (870 nm) leds and a 90sr/90y beta source. post-ir irsl signals were filtered through corning 7-59 and schott bg-39 filters. the fine grains were mounted on 9.8 mm stainless steel cups using a pipette with acetone suspension (~2 mg/ml). the post-ir irsl single aliquot regeneration (sar) protocol (pirir225) was used for de estimation (buylaert et al., 2009, 2012; thiel et al., 2011). aliquots were preheated at 251 °c for 60 seconds, then stimulated twice with ir light for 200 seconds, first at 50 °c (ir signal), then at 225 °c (post-ir signal). a 200-second ir bleach at 290 °c concluded each sar cycle to remove any residual signals. at least 20 aliquots per sample were analysed, and both recycling ratios and recuperation were assessed. the luminescence signal was derived from the first 2 seconds of stimulation, subtracting the final 50 seconds as background. to determine the environmental dose rate, surrounding sediment was dried at 50 °c, sealed in airtight containers for over 21 days to allow radon-222 equilibrium with radium-226 and then analyzed via gamma spectrometry using a high-purity germanium (hpge) detector to measure concentrations of 238u, 232th, and 40k. all luminescence data were processed using risø analyst software, and dose rates and final age estimates were calculated using the drac (dose rate and age calculator) version 1.2 (durcan et al., 2015). 4. results 4.1. field characteristics and overall stratigraphic architecture field mapping and sedimentary logging at the carboj river mouth reveal a stratigraphic succession capping the maragani relief, bounded by the capo san marco plateau to the southeast and the present coastline to the southwest (fig. 1). the relief itself stretches over 2 km in a nw-se direction and is constructed from a basal unit of laminated sandy clays and marls, several tens of meters thick, assigned to the early pleistocene (agga) (fig. 3). this unit is unconformably overlain by well-stratified reddishbrown sands and weakly cemented calcarenites, up to ten meters thick (unit gn5; fig.s 2, 3), which define the key morphosedimentary expression. the relief terminates abruptly to the northeast at the maragani valley, an incised linear depression notably lacking any visible upstream catchment or channel incision. this valley 122 srivastava e. et al. cluding mollusc, echinoderm, and ostracod valve fragments (tab. 1). 4.3. stratigraphy, sedimentology, and osl chronology of the gn5 deposits (sample s2) the reddish-brown calcarenite outcrops of the marine terrace deposits (unit gn5), which unconformably overlie the early pleistocene marls and clays of the agga (fig.s 5a, 6a), are organised in well-stratified, centimetre-thick beds showing sub-parallel to moderately cross-bedded stratification (fig. 6b). closer inspection of the outcrop (fig. 6c) reveals alternating sets of planar and cross-laminated beds, with clear evidence of herringbone structures, as well as storm-generated erosional surfaces truncating previously deposited layers (fig. 6d). some beds show weak channelisation, suggesting deposition in a nearshore environment shaped by the combined action of tidal currents and moderate wave energy. the dip directions of the strata and laminae observed in the cross-bedded and herringbone structures are oriented torwards ne and sw. at the northwestern end of the maragani relief (fig.s 1a, 4, 6a, 6d), where the same unit (gn5) is also exposed, we collected sample s2. the outcrop at the sampling site shows well-stratified, centimetre-thick reddish-brown weakly cemented calcarenites alternating with moderately sorted fine sands. the sediments were subsequently examined under reflected-light optical separates the relief from the capo san marco staircase. on its southern edge, the relief is bounded by low-lying alluvial deposits (unit ba1) that extend to the present-day shoreline. 4.2. micropalaeontology and sedimentology of the agga unit (sample s1) two sediment samples were analyzed from the maragani sequence (fig. 4). sample s1, collected from the lower agga unit, showed a fine-grained matrix dominated by clay and marl, with minor sandy silt (fig.s 4, 5a, b). micropaleontological analyses revealed a rich and well-preserved planktonic foraminiferal assemblage including globigerinoides ruber, g. elongatus, g. tenellus, globoconella inflata, neogloboquadrina pachyderma, and neogloboquadrina incompta (tab. 1; fig. 5c). benthic taxa include hyalinea balthica, a marker for the middle calabrian (azzaroli et al., 1996; caruso, 2004; cita et al., 2008; montana et al., 2024). on the basis of the planktonic foraminifera biostratigraphy, sample s1 was attributed to the middle part of the mple1 zone “globigerina cariacoensis interval zone” (lirer et al., 2019). therefore, the occurrence of hyalinea balthica and the evidence on planktonic foraminiferal assemblage point to a middle calabrian age (emilian substage) for this sample. the sample also contained quartz, calcite, pyrite, and mica fragments, as well as abundant bioclasts, in 123 fig. 4 lithostratigraphic sketch of the sampled outcrops from the maragani relief. here sample s1 refers to the grey-brownish marls and clays of the agrigento fm. (agga) and s2 to the well-stratified, reddish-brown calcarenites of unit gn5, organized in sub-parallel to moderately cross-bedded layering. fig. 3 (a) location of the point from which the photo was taken. the black line represents the topographic profile trace along with outcrop locations in red (agga) and blue (gn5); (b) panoramic view of the carboj river mouth (on the right), maragani relief, maragani valley and capo s. marco plateau (on the left); (c) topographic profile derived from the dem, corresponding to the panoramic view shown in figure b. additionally, the corresponding lithologies and their geometric relationships have been reported below the topographic profile. relict bar at the carboj river mouth, south-western sicily 124 tab. 1 multi-disciplinary information of collected samples from the maragani relief. fig. 5 (a) a section on the maragani relief showing the agrigento fm. (aggₐ) unconformably overlain by the marine terrace deposits (gn) of the maragani relief. the red square indicates the site where sample s1 was collected; (b) detail of the grey-brownish marls and clays of the agrigento fm. (agga) is shown, with the indication of the sampling point s1; (c) microphotograph of sample s1 taken with a reflectedlight optical microscope (fraction larger than 125 µm) revealing the main planktonic and benthic foraminiferal taxa identified. the genus and species of the various planktonic and benthic foraminifera taxa are indicated by white labels. planktonic foraminifera: g.t.= globigerinoides tenellus; g.i.= globoconella inflata; n.p.= neogloboquadrina pachyderma (left coiling). benthic foraminifera: h.b.= hyalinea balthica; m.p.= melonis padanum. sample elevation (m a.s.l.) lithology lithic fragments bioclasts biostratigraphic markers biozone chronostratigraphy s1 23 clays and marls with minor sandy silts quartz, calcite, pyrite, and micas mollusc, echinoderm and ostracod shell fragments, and foraminiferal tests planktonic foraminifera (globoconella inflata, globigerinoides tenellus, neogloboquadrina pachyderma); benthic foraminifera (hyalinea balthica) mple1 early pleistocene (middle calabrian) s2 51 moderately sorted fine sands and weakly cemented calcarenites calcite, quartz, crystalline carbonate fragments, minor pyrite, glauconite, and gypsum foraminiferal tests late pleistocene (77±6.1 ka) srivastava e. et al. 5. discussion 5.1. origin and depositional setting of the maragani relief the maragani relief illustrates how broad tectonic and sea-level patterns, well documented along the southwestern sicilian coast, can manifest in distinctive ways at the local scale. while studies such as ferranti et al. (2021) and pucci et al. (2023) have mapped and dated classic stepped marine terraces in the menfiselinunte-sciacca sector, our observations at the carboj river mouth reveal a coastal landform that does not conform to the canonical model of terrace formation through marine abrasion or progradation. in this respect, microscopy (fig. 6e). the sample reveals moderately sorted fine sands composed predominantly of angular to sub-rounded grains of calcite and quartz, followed by crystalline carbonate fragments, minor pyrite, and trace amounts of glauconitic grains and rare gypsum. notably, the sample includes bioclasts, both reworked planktonic and benthic foraminifera (tab. 1). the osl sample (s2-osl), taken from the same stratigraphic level as s2, yielded an age of 77±6.1 ka, placing the deposit within mis 5a (fig. 7). this result provides a minimum age for the formation of the maragani surface and is consistent with its elevation relative to other dated marine terraces in the region. 125 fig. 6 (a) outcrop view of the maragani relief showing marine terrace deposits (gn) unconformably overlying the early pleistocene agrigento formation (aggₐ). the unconformity is traced by the red line. sample s2 (gn5) was collected near the central part of the ridge, while sample s1 (aggₐ) lies at its base. (b) close-up of the outcrop showing well-stratified, reddish-brown calcarenites of unit gn5, organized in sub-parallel to moderately cross-bedded centimetric layers. (c) detail from the same outcrop highlighting alternating sets of planar and cross-laminated beds, with evidence of herringbone structures indicative of tidal influence. (d) lateral view of the same stratigraphic interval showing internal bedding, weak channelization, and storm-generated erosional surfaces (red dashed line), with the sample s2 location. (e) reflected-light optical micrograph of the s2 sample (fraction >63 µm) displaying moderately sorted fine sands composed of angular to sub-rounded grains of calcite and quartz, along with bioclasts, pyrite, crystalline carbonate fragments, and accessory glauconite, and rare gypsum. the sedimentary features point to a tideand wave-influenced nearshore depositional setting. relict bar at the carboj river mouth, south-western sicily incision, and no evidence of channelized fluvial processes. this rules out a fluvial origin and points instead to a coastal depositional environment. micropaleontological and lithostratigraphic analysis of the two sampled units, s1 from the agga and s2 from the overlying marine terrace deposits (gn5), reveals a stark contrast in depositional settings and ages. the lower agga unit comprises clay-rich marls with a well-diversified planktonic and benthic foraminiferal assemblage including globigerinoides ruber, g. elongatus, globoconella inflata, neogloboquadrina spp., and hyaour interpretation diverges from previous reconstructions of terrace architecture in the region, which largely emphasise planar abrasion platforms and progradational foresets. instead, the maragani relief represents a geomorphic anomaly that complements, rather than contradicts, the broader regional framework. the geometry is the first clue, as the maragani relief is a narrow, elongated feature perched at approximately 55 m a.s.l., oriented parallel to the coastline but perpendicular to the carboj river mouth. the adjacent maragani valley exhibits no upstream catchment, no 126 fig. 7 (a) sampling of the sandy unit (gn5) from the maragani relief for luminescence dating (sample s2-osl); (b) grain-size distribution of the sampled horizon; (c-d) natural and regenerated luminescence decay curves (ln, lₓ; tn, tₓ) obtained from the post-ir irsl (pirir225) single aliquot regeneration (sar) protocol; (e) dose-response curve used for equivalent dose (dₑ) determination; (f) sensitivity change between sar cycles; (g) quality control parameters showing recycling ratios, recuperation rates, and palaeodose errors within acceptance limits; (h) abanico plot of individual aliquot dₑ values; the calculated age is 77.64 ± 6.09 ka, placing the deposit within mis 5a. srivastava e. et al. 5.3. local morphodynamics and evolutionary model what makes the maragani relief distinctive is its isolation and the absence of similar features at other nearby river mouths. a likely explanation is that, during mis 5a, the carboj river entered a locally subsiding or flexurally warped coastal sector, possibly along a frontal splay of the sftb. in such a setting, low fluvial discharge combined with local bathymetry would have allowed wave and tidal processes to dominate sediment redistribution and promote mouth-bar formation near sea level. the preservation of this feature at elevation reflects subsequent regional uplift. further support comes from the alignment of the relief and the sedimentary structures, which indicate southeast-to-northwest longshore transport during the highstand. these directions differ from the modern setting and likely reflect different bathymetric configurations, wave-refraction patterns, or the influence of nowsubmerged barriers (micallef et al., 2013; lodolo et al., 2023). circulation features such as the adventure bank vortex underscore how sensitive local hydrodynamics are to bathymetric changes, especially during different sea-level stands (omrani et al., 2016; borzì et al., 2022; spatola et al., 2023). alternative origins, including fault-controlled basins or catastrophic flooding, can be dismissed. there is no evidence of major reverse faulting, and no chaotic breccias or debris-flow deposits are present. instead, the sedimentary architecture and fossil assemblages support a long-lived shallow-marine system modulated by relative sea level and uplift (parrino et al., 2023; srivastava et al., 2023; agate et al., 2025). the conceptual model in figure 8 outlines this evolution in four stages. during stage 1, the agga unit accumulated in a deep marine setting during a period of regional subsidence, establishing the structural and stratigraphic base of the maragani relief. although a terrace associated with mis 7 is not preserved in the logged section. stage 2 likely corresponds to relative sea-level fall and regional uplift during mis 6. this resulted in partial erosion, deformation, and preparation of the substrate for renewed deposition. stage 3 marks the mis 5a highstand, during which the carboj river mouth occupied a shallow, waveand tide-influenced embayment. here, the gn5 calcarenites were deposited as a mixed-energy mouth bar, shaped by alternating tidal flows, wave reworking, and southeast-to-northwest longshore transport. these deposits now preserve a clear record of highstand shoreline dynamics. finally, in stage 4, regional uplift along the sftb gradually raised the entire depositional surface to its current elevation, approximately 55 m above sea level, isolating it from further reworking. the juxtaposition of the s1 and s2 horizons, which respectively record deep marine and shallow coastal processes, shows how even a single relief can encapsulate more than a million years of stratigraphic and tectonic history. 6. conclusion this contribution puts forward a new hypothesis for understanding landscape evolution along a key stretch of the southern sicilian coastline with just recent information on the uplift rate. the staged conceptual model we present (fig. 8) integrates geomorphological, stratigraphic, and chronological evidences. this showcases linea balthica, the latter indicating a middle calabrian (emilian) age. these assemblages point to upperbathyal, open-marine sedimentation on a tectonically active slope within the sftb foredeep. the absence of coastal indicators confirms deposition well offshore prior to any emergence of the maragani relief. in contrast, the overlying calcarenites of unit gn5 show well-stratified, moderately cross-bedded layers with alternating planar and cross-laminated sets and herringbone structures typical of tidal environments or under wave influence in shallow water (foreshore/upper shoreface) settings, hinting at an alternately paleocurrent direction of ne and sw (nichols, 2009; van den berg and martinius, 2024). weak channelisation and moderate sorting further support deposition within a mixed-energy nearshore system, consistent with a wave and tide-modulated mouth bar (walker & plint, 1992; cole et al., 2021). this facies arrangement differs from the classic terrace facies described by ferranti et al. (2021), highlighting that not all elevated coastal surfaces in this region originated from the same geomorphic mechanism. the unconformity separating the agga and gn5 units marks a significant break in depositional history, recording burial, deformation, exposure, and truncation of the agga marls prior to renewed highstand sedimentation. this transition integrates tectonic uplift, relative sea-level change, and coastal dynamics operating over >1 myr. similar stratigraphic discontinuities have been inferred regionally, but our section provides a rare outcrop-based example along the southwestern sicilian margin. 5.2. sea-level history and uplift rates along the sicilian margin the osl age of approximately 77 ka from the gn5 calcarenites places the highstand deposition in mis 5a. although mis 5e, around 125 ka, is commonly used as the principal highstand marker in sicily, the maragani relief stands at a comparable elevation despite its younger age. this yields a long-term uplift rate of approximately 0.9-1.0 mm yr-1, which is consistent with the uplift values reconstructed by ferranti et al. (2021) for the menfi-selinunte-sciacca sector. thus, our uplift estimate aligns with regional patterns and indicates that mis 5a highstands can reach elevations similar to mis 5e under sustained uplift. in terms of reconstructed sealevel oscillations and uplift rates, our results therefore corroborate previous regional interpretations, even though the geomorphic expression at maragani differs from classic terrace flights. this relationship also highlights an important methodological contrast. many previous uplift reconstructions across sicily rely on mis 5e indicators dated through faunal markers or lower-precision age methods, such as amino acid racimization (aar), electron spin resonance (esr), or u/th on cladocora caespitosa (linnaeus, 1767) and molluscs, as summarised in antonioli et al. (2025). these approaches often assign a nominal mis 5e age and may underestimate uplift where highstand correlation is uncertain. our osl age provides a higherprecision constraint for this sector and demonstrates the value of integrating luminescence dating into coastal uplift studies along the sicilian margin. in this sense, our results are methodologically distinct but broadly consistent with existing uplift frameworks, while helping to refine the timing and elevation of younger highstands. 127 relict bar at the carboj river mouth, south-western sicily 128 fig. 8 conceptual model illustrating the proposed evolutionary stages of the maragani relief: (a-b) stage 1 (mis 7 highstand): deposition of shallow-marine calcarenites overlying the early pleistocene marls and clays of the agrigento fm. (agga) under alongshore current influence; (c-d) stage 2 (mis 6 lowstand): after relative sea-level fall, valley incision, and initial tectonic uplift of the coastal margin; (e-f) stage 3 (mis 5 highstand): formation of a wave-dominated sand bar at the carboj river mouth under high-energy conditions in the sicily channel, followed by continued uplift; (g-h) stage 4 (recent): present-day morphology with the maragani relief capped by mis 5a marine sands (sample s2) overlying the agrigento fm. (sample s1). srivastava e. et al. (italy): a benchmark of coastal tectonics. quaternary international, 145-146, 3-18. doi: 10.1016/j.quaint.2005.07.002 antonioli f., ferranti l., agate m., ascione a., cerrone c., de santis v., deiana g., fontana a., furlani s., leoni g. (2025) the last interglacial transgression in italy: the breath of the italian coasts documented by 461 sites. quaternary science reviews 360, 109376. doi: 10.1016/j.quascirev.2025.109376 ayyad h.m., bazeen y.s., samir a., ghanem s.g., ali a.h., gaafar a.t., abdel-gawad a. (2025) foraminiferal proxies reveal miocene climatic shifts in the gulf of suez: insights from the rudeis and kareem formations on lithostratigraphic ambiguities and central paratethys climatic linkages during burdigalian-langhian intervals. geological journal. doi: 10.1002/gj.70000 azzaroli a., colalongo m.l., nakagawa h., pasini g., rio d., ruggieri g., sartoni s., sprovieri r. (1996) the pliocene-pleistocene boundary in italy, in: the pliocene-pleistocene boundary: definition and worldwide correlation. cambridge university press, 141-155. hdl.handle.net/11577/2522336 besler h. (2008) the granulometric analysis. in developments in sedimentology, 59, 73-98. doi: 10.1016/s0070-4571(07)10005-4 bonfardeci a., caruso a., bartolini a., bassinot f., blanc -valleron m.m. (2018) distribution and ecology of the globigerinoides ruber-globigerinoides elongatus morphotypes in the azores region during the late pleistocene-holocene. palaeogeography, palaeoclimatology, palaeoecology, 491, 92-111. doi: 10.1016/j.palaeo.2017.11.052 borzı a.m., minio v., cannavò f., cavallaro a., d’amico s., gauci a., de plaen r., lecocq t., nardone g., orasi a. (2022) monitoring extreme meteomarine events in the mediterranean area using the microseism (medicane apollo case study). scientific reports, 12, 21363. doi: 10.1038/s41598-022-25395-9 bull w.b. (1984) tectonic geomorphology. journal of geological education, 32, 310-324. doi: 10.5408/0022-1368-32.5.310 buylaert j.-p., murray a.s., thomsen k.j., jain m. (2009) testing the potential of an elevated temperature irsl signal from k-feldspar. radiation measures, 44, 560-565. doi: 10.1016/j.radmeas.2009.02.007 buylaert j., jain m., murray a.s., thomsen k.j., thiel c., sohbati r. (2012) a robust feldspar luminescence dating method for middle and late pleistocene sediments. boreas, 41, 435-451. doi: 10.1111/j.1502-3885.2012.00248.x caruso a. (2004) climatic changes during late pliocene and early pleistocene at capo rossello (sicily, italy): response from planktonic foraminifera. presented at the proceedings of the first italian meeting on environmental micropaleontology: grzybowski foundation special publication, 17-36. catalano r., stefano e., sulli a., vitale f., infuso s., vail p. (1998) sequences and systems tracts calibrated by high-resolution bio-chronostratigraphy: the central mediterranean plio-pleistocene record. how local coastal features, like the maragani relief, record the interplay of regional tectonic uplift driven by the sicilian fold and thrust belt and global sea-level fluctuations during the late quaternary, and how these signals compare with previously reconstructed terrace frameworks and uplift patterns along the sicilian margin. what this study highlights is that coastal evolution is not just a story of rising or falling seas. it’s also about whether sea-level highstands align with stable surfaces and sufficient sediment supply or miss their window entirely. the maragani relief, with its unusual geometry and depositional history, stands as a clear example of how these factors can converge to produce coastal landforms that don’t fit neatly into regional models, but still hold the imprint of broader geodynamic trends. at the same time, our uplift estimate is derived from a single osl-dated shoreline unit; although it is consistent with values reported for the menfi-selinunte-sciacca sector, it underlines the need for additional, high-precision dating across southwestern sicily to test and refine these interpretations. while further quantitative modelling would enhance this interpretation, the stratigraphic and morphotectonic evidence provided here establishes a solid framework for future tectono-sedimentary investigations in the region. building on the still sparse but growing body of dated coastal records from the sicilian margins, this knowledge is essential not only for advancing geological understanding but also for informing sustainable coastal management strategies aimed at preserving the cultural and environmental heritage of the mediterranean landscape. acknowledgement funding for this research came from carg projects (ispra-italian geological survey): sciacca (sheet 628, pi a. sulli) and castelvetrano (sheet 618, pi m. agate). moreover, we extend our sincere thanks to the editor in chief, dr. ilaria mazzini, and the two anonymous reviewers for their feedbacks and for handling the manuscript. author contribution: as, ma, and mgm oversaw the overall research. es, np, and ab conducted fieldwork, analyzed and interpreted the data, developed the landscape model with figures, and drafted the manuscript. fc, pb, and am contributed to visualization and review of the manuscript. es, md, and jnm supervised and assisted with the analysis and interpretation of the luminescence data. references agate m., antonioli f., caldareri f., devoto s., gasparo morticelli m., sulli a., parrino n., furlani s. (2025) decoding late quaternary faulting through marine terraces and mis 5.5 tilted tidal notches: insights from central mediterranean sea (nw sicily, italy). geomorphology, 472, 109587. doi: 10.1016/j.geomorph.2024.109587 amadei m., bagnaia r., di bucci d., laureti l., lugeri f.r., nisio s., salvucci r. (2000) carta della natura alla scala 1: 250.000: carta dei tipi e delle unità fisiografiche di paesaggio d’italia. antonioli f., kershaw s., renda p., rust d., belluomini g., cerasoli m., radtke u., silenzi s. (2006) elevation of the last interglacial highstand in sicily 129 relict bar at the carboj river mouth, south-western sicily https://doi.org/10.1016/j.geomorph.2024.109587 co e., cosentino c., sierro f.j., caruso a. (2019) mediterranean neogene planktonic foraminifer biozonation and biochronology. earth-science reviews, 196, 102869. doi: 10.1016/j.earscirev.2019.05.013 lodolo e., nannini p., baradello l., ben-avraham z. (2023) two enigmatic ridges in the pantelleria vecchia bank (nw sicilian channel). heliyon, 9 (3), e14575. doi: 10.1016/j.heliyon.2023.e14575 mahan s.a., rittenour t.m., nelson m.s., ataee n., brown n., dewitt r., durcan j., evans m., feathers j., frouin m. (2023) guide for interpreting and reporting luminescence dating results. gsa bulletin, 135, 1480-1502. doi: 10.1130/b36404.1 malatesta l.c., finnegan n.j., huppert k.l., carreño e.i. (2022) the influence of rock uplift rate on the formation and preservation of individual marine terraces during multiple sea-level stands. geology, 50, 101-105. doi: 10.1130/g49245.1 malik j.n., srivastava e., gadhavi m.s., livio f., sharma n., arora s., parrino n., burrato p., sulli a. (2024) holocene surface-rupturing paleoearthquakes along the kachchh mainland fault: shaping the seismic landscape of kachchh, western india. scientific reports, 14, 11612. doi: 10.1038/s41598-024-62086-z miall a. d. (2022) facies analysis. in stratigraphy: a modern synthesis, 91-174. springer international publishing, cham. doi: 10.1007/978-3-030-87536-7_3 micallef a., foglini f., le bas t., angeletti l., maselli v., pasuto a., taviani m. (2013) the submerged paleolandscape of the maltese islands: morphology, evolution and relation to quaternary environmental change. marine geology, 335, 129-147. doi: 10.1016/j.margeo.2012.10.017 montana g., gasparo morticelli m., bonfardeci a., bechtold b., randazzo l. (2024) late 6th-early 4th century bce western greek amphorae produced in selinunte (western sicily): ceramic paste characterisation by an integrated archaeometric approach. journal of archaeological science: reports, 58, 104698. doi: 10.1016/j.jasrep.2024.104698 nichols g. (2009) sedimentology and stratigraphy. john wiley & sons, pp. 432. omrani h., arsouze t., béranger k., boukthir m., drobinski p., lebeaupin-brossier c., mairech h. (2016) sensitivity of the sea circulation to the atmospheric forcing in the sicily channel. progress in oceanography, 140, 54-68. doi: 10.1016/j.pocean.2015.10.007 parrino n., burrato p., sulli a., gasparo morticelli m., agate m., srivastava e., malik j.n., di maggio c. (2023) plio-quaternary coastal landscape evolution of north-western sicily (italy). journal of maps, 19, 2159889. doi: 10.1080/17445647.2022.2159889 parrino n., pepe f., burrato p., dardanelli g., corradino m., pipitone c., gasparo morticelli m., sulli a., di maggio c. (2022) elusive active faults in a low strain rate region (sicily, italy): hints from a multi155-177. doi: 10.2110/pec.98.02.0155 cita m.b., capraro l., ciaranfi n., di stefano e., lirer f., maiorano p., marino m., raffi i., rio d., sprovieri r. (2008) the calabrian stage redefined. episodes journal of international geoscience, 31, 408 -419. doi: 10.18814/epiiugs/2008/v31i4/006 cole g., jerrett r., watkinson m.p. (2021) a stratigraphic example of the architecture and evolution of shallow water mouth bars. sedimentology, 68, 1227-1254. doi: 10.1111/sed.12825 d’angelo u., vernuccio s. (1996) i terrazzi marini quaternari della estremità occidentale della sicilia. memorie della società geologica italiana, 51, 585594. di maggio c., madonia g., vattano m., agnesi v., monteleone s. (2017) geomorphological evolution of western sicily, italy. geologica carpathica, 68, 80. dumas b., guérémy p., raffy j. (2005) evidence for sea-level oscillations by the “characteristic thickness” of marine deposits from raised terraces of southern calabria (italy). quaternary science reviews, 24, 2120-2136. doi: 10.1016/j.quascirev.2004.12.011 durcan j.a., king g.e., duller g.a.t. (2015) drac: dose rate and age calculator for trapped charge dating. quaternary geochronology, 28, 54-61. doi: 10.1016/j.quageo.2015.03.012 ferranti l., antonioli f., mauz b., amorosi a., dai pra g., mastronuzzi g., monaco c., orrù p., pappalardo m., radtke u., renda p. (2006) markers of the last interglacial sea-level high stand along the coast of italy: tectonic implications. quaternary international, 145, 30-54. doi: 10.1016/j.quaint.2005.07.009 ferranti l., monaco c., antonioli f., maschio l., kershaw s., verrubbi v. (2007) the contribution of regional uplift and coseismic slip to the vertical crustal motion in the messina straits, southern italy: evidence from raised late holocene shorelines. journal of geophysical research: solid earth, 112(b6). doi: 10.1029/2006jb004473 ferranti l., burrato p., sechi d., andreucci s., pepe f., pascucci v. (2021) late quaternary coastal uplift of southwestern sicily, central mediterranean sea. quaternary science reviews, 255, 106812. doi: 10.1016/j.quascirev.2021.106812 ferraro s., incarbona a., bonomo s., capotondi l., giaramita l., langone l., tranchida g. (2024) planktonic foraminifera response to the azores high and industrial-era global warming in the central-western mediterranean sea. global and planetary change, 240, 104532. doi: 10.1016/j.gloplacha.2024.104532 gasparo morticelli m., valenti v., catalano r., sulli a., agate m., avellone g., albanese c., basilone l., gugliotta c. (2015) deep controls on foreland basin system evolution along the sicilian fold and thrust belt. bulletin de la société géologique de france, 186, 273-290. doi: 10.2113/gssgfbull.186.4-5.273 lirer f., foresi l.m., iaccarino s.m., salvatorini g., tur 130 srivastava e. et al. sulli a., presti v. l., morticelli m. g., antonioli f. (2013) vertical movements in ne sicily and its offshore: outcome of tectonic uplift during the last 125 ky. quaternary international, 288, 168-182. doi: 10.1016/j.quaint.2012.01.021 sulli a., agate m., gasparo morticelli m., todaro s., bonfardeci a., avellone g., rizzo g.f., maiorana m., gennuso m., parrino n., petrella f., incarbona a., di maggio c., rotigliano e., cappadonia c., madonia g., muraro c. (2024) carta geologica d’italia alla scala 1:50.000, f. 628 sciacca. ispra servizio geologico d’italia, roma. thiel c., buylaert j.-p., murray a., terhorst b., hofer i., tsukamoto s., frechen m. (2011) luminescence dating of the stratzing loess profile (austria): testing the potential of an elevated temperature postir irsl protocol. quaternary international, 234, 23-31. doi: 10.1016/j.quaint.2010.05.018 van den berg j.h., martinius a.w. (2024) recognition of cross-shore dynamics of longshore bars in upper-shoreface deposits of prograding sandy coastal barriers. journal of sedimentary research, 94, 382-401. doi: 10.2110/jsr.2023.116 walker r.g., plint a.g. (1992) waveand stormdominated shallow marine systems. in: facies models response to sea level change, 219238. wintle a.g. (2008) luminescence dating: where it has been and where it is going. boreas, 37, 471-482. doi: 10.1111/j.1502-3885.2008.00059.x disciplinary land-to-sea approach. tectonophysics, 839, 229520. doi: 10.1016/j.tecto.2022.229520 pavano f., pazzaglia f.j., catalano s. (2016) knickpoints as geomorphic markers of active tectonics: a case study from northeastern sicily (southern italy). lithosphere, 8, 633-648. doi: 10.1130/l577.1 pucci s., avellone g., contino a., incarbona a., sagnotti l., sulli a., di stefano e., smedile a., gueli a.m., stella g. (2023) geology of the lower belice river valley, epicentral area of the m > 5 1968 seismic sequence (south-western sicily, italy). journal of maps, 19, 2242725. doi: 10.1080/17445647.2023.2242725 sabbatini a., morigi c., nardelli m.p., negri a. (2014) foraminifera. in goffredo s., dubinsky z. (eds), the mediterranean sea. springer, dordrecht. doi: 10.1007/978-94-007-6704-1_13 sharma r., singh y., singh r., malik j.n., dhali m., srivastava e., sharma n. (2024) appraisal of active tectonics: an insight from the morphotectonic study of drainage basins and osl dating in the kangra area, himachal pradesh. journal of the geological society of india, 100, 996-1006. doi: 10.17491/jgsi/2024/173942 spatola d., sulli a., basilone l., casalbore d., napoli s., basilone g., chiocci f.l. (2023) morphology of the submerged ferdinandea island, the ‘neverland’ of the sicily channel (central mediterranean sea). journal of maps, 19, 2243305. doi: 10.1080/17445647.2023.2243305 srivastava e., malik j.n., parrino n., burrato p., sharma n., gadhavi m., sulli a., di maggio c., gasparo morticelli m. (2023) extremely fast holocene coastal landscape evolution in the kachchh upland (nw india): clues from a multidisciplinary review. journal of maps, 19, 2167617. doi: 10.1080/17445647.2023.2167617 srivastava e., gadhavi m., sharma n., kumar p., malik j.n., sulli a. (2025) geomorphic imprints of long and short-term deformation in the kachchh intraplate region (western india). geomorphology, 109890. doi: 10.1016/j.geomorph.2025.109890 131 relict bar at the carboj river mouth, south-western sicily ms. received: september 30, 2025 revised: november 27, 2025 accepted: november 28, 2025 available online: december 5, 2025 132 available online http://amq.aiqua.it issn (print): 2279-7327, issn (online): 2279-7335 alpine and mediterranean quaternary, 36 (2), 2023, 221-284 the italian quaternary volcanism stefano branca 1 , alessandra cinquegrani 2 , raffaello cioni 3 , aida maria conte 4 , sandro conticelli 3, 4 , gianfilippo de astis 5 , sandro de vita 6 , rosanna de rosa 7 , mauro antonio di vito 6 , paola donato 7 , francesca forni 8 , lorella francalanci 3 , mario gaeta 9 , biagio giaccio 4 , guido giordano 10, 4 marisa giuffrida 11 , roberto isaia 6 , federico lucchi 12 , fabrizio marra 5 , silvia massaro 13 , eugenio nicotra 7 , danilo m. palladino 9 , cristina perinelli 9, 4 , paola petrosino 14 , marco pistolesi 15 , josé pablo sepulveda-birke 3 , gianluca sottili 9 , claudia romagnoli 12 , silvio rotolo 2, 16 , roberto sulpizio 13 , claudio antonio tranne 12 , marco viccaro 11, 1 1 istituto nazionale di geofisica e vulcanologia sezione di catania, osservatorio etneo, italy. 2 dipartimento di scienze della terra e del mare, università degli studi di palermo, palermo, italy. 3 dipartimento di scienze della terra, università degli studi di firenze, firenze, italy. 4 cnr istituto di geologia ambientale e geoingegneria, montelibretti e roma, italy. 5 istituto nazionale di geofisica e vulcanologia sezione di sismologia e tettonofisica, roma, italy. 6 istituto nazionale di geofisica e vulcanologia osservatorio vesuviano, napoli, italy. 7 dipartimento di biologia, ecologia e scienze della terra, università della calabria, arcavacata di rende (cs), italy. 8 dipartimento di scienze della terra, università di milano la statale, milano (mi), italy. 9 dipartimento di scienze della terra, sapienza, università di roma, roma, italy. 10 dipartimento di scienze dell’università degli studi roma iii, roma, italy. 11 dipartimento di scienze biologiche, geologiche e ambientali, università di catania, catania, italy. 12 dipartimento di scienze biologiche, geologiche e ambientali, università di bologna, bologna, italy. 13 dipartimento di scienze della terra e geoambientali, università di bari, italy. 14 dipartimento di scienze della terra, dell'ambiente e delle risorse, università degli studi di napoli federico ii, napoli, italy. 15 dipartimento di scienze della terra dell’università degli studi di pisa, pisa, italy. 16 istituto nazionale di geofisica e vulcanologia sezione di palermo, palermo, italy. corresponding authors: biagio giaccio <biagio.giaccio@cnr.it> and paola petrosino <paola.petrosino@unina.it> abstract: the peninsular and insular italy are punctuated by quaternary volcanoes and their rocks constitute an important aliquot of the italian quaternary sedimentary successions. also away from volcanoes themselves, volcanic ash layers are a common and frequent feature of the quaternary records, which provide us with potential relevant stratigraphic and chronological markers at service of a wide array of the quaternary science issues. in this paper, a broad representation of the italian volcanological community has joined to provide an updated comprehensive state of art of the italian quaternary volcanism. the eruptive history, style and dynamics and, in some cases, the hazard assessment of about thirty quaternary volcanoes, from the northernmost mt. amiata, in tuscany, to the southernmost pantelleria and linosa, in sicily channel, are here reviewed in the light of the substantial improving of the methodological approaches and the overall knowledge achieved in the last decades in the volcanological field study. we hope that the present review can represent a useful and agile document summarising the knowledege on the italian volcanism at the service of the quaternary community operating in central mediterranean area. keywords: italian volcanisms, stratigraphy, geochronology, eruptive dynamics, distal tephra. 1. introduction (s.c., b.g., p.p.) volcanic products undoubtedly represent an important part of the quaternary deposits in italy. for this reason, we have decided to take the opportunity offered by the inqua conference to be held in rome in 2023 to present a review of the state of the art and knowledge of the italian quaternary volcanism. a few remarks should be made to explain why we felt the need to do this. the activity of the italian quaternary volcanoes during the last century has been the subject of intense investigations, although at first the main focus was on mineralogical-petrographical-magmatological aspects other than on the strictly volcanological ones. it was probably in the decade 1980-1990, with the publication of the results of the “progetto finalizzato geodinamica” of the italian national research council (cnr), that monographic works were published on some volcanic areas, such as the neapolitan volcanoes or etna, which, in addition to the petrographic features, proposed a systematic study of the stratigraphic aspects of the products, mapping their distribution and thus providing a reconstruction of their eruptive history (e.g., santacroce, 1987 for somma-vesuvio, rosi & sbrana, 1987 for campi flegrei, vezzoli, 1988 for ischia, romano et al., 1979 for etna, etc.). since then, and especially in the last two decades, this reconstruction has been progressively refined due to the improved knowledge of volcanic history and stratigraphy, in particular thanks to the cartografia geologica e geotematica (carg) project (e.g. groppelli & viereck-goette, 2010), dedicated to updating the geologihttps://doi.org/10.26382/amq.2023.09 mailto:biagio.giaccio@cnr.it mailto:paola.petrosino@unina.it 222 fig. 1 location of the italian quaternary volcanoes with indication of the time interval of activity (ma, unless differently indicated). branca s. et al. cal mapping of the italian territory. a multidisciplinary approach (stratigraphic, geomorphological, geochemical) allowed the reconstruction of the time-space history of most of the italian quaternary volcanic areas, which has been furthered by the increased ability to obtain reliable 40ar/39ar ages on both pyroclastic deposits and lavas. in fact, the significant technological developments of noble gas mass spectrometers over the last decade (mixon et al., 2022), have improved the effectiveness of the method and the possibility of getting accurate and highprecision 40ar/39ar dating allowing a detailed and robust reconstruction of the eruptive history. this has been made possible and facilitated by the peculiar potassic nature of the magmas feeding the peri-tyrrhenian potassic quaternary volcanoes (e.g., peccerillo, 2017), which generated products bearing k-rich minerals (e.g., sanidine and leucite), ideal for direct 40ar/39ar dating. furthermore, with regard to the explosive activity, the great deal of tephrostratigraphic research on distal stratigraphic successions, i.e., located tens to thousands of km from the volcanic sources, substantially contributed to increase the knowledge on the recurrence, temporal extent and dynamics of explosive activity, providing integrative information that are difficult to detect in the proximal areas (e.g., monaco et al., 2021, 2022a; leicher et al., 2023). finally, the last twenty years have seen an increase in research aimed at evaluating volcanic risk in areas of active volcanism, with particular reference to hazard assessment based on knowledge of past eruptive history (e.g., cioni et al., 2003; lirer et al., 2010; del negro et al., 2013; bevilacqua et al., 2022 and references therein). given these premises, it seemed important to gather the contributions of various members of the italian volcanological community in order to present an updated review on the italian quaternary volcanoes. to emphasize the volcanological aspects over the petrographicmagmatological ones as companion papers we deliberately decided to not adopt the division into magmatic provinces (see conticelli et al., 2010, 2015a; peccerillo, 2017; and references in these papers and book) but to list the italian quaternary volcanoes in a simple and neutral geographical way, starting the from tuscany and then moving southward on to those located in lazio, campania, tyrrhenian sea and sicily (fig. 1). for each volcanic area or volcano dealt with, a summary of the eruptive history is proposed, focusing on the dynamics in relation to time, with emphasis on the most recent researches, and shortly mentioning the chemistry of the products. for the active volcanic areas, particularly those exposed to higher risk, information is also given on the state of hazard and risk assessment research. we hope that this paper will be a valid support for the studies of the quaternary community, which very often has to deal with the eruptive history of the italian volcanoes and for which it is extremly necessary to have an agile, exhaustive and up-to-date general framework. 2. geodynamic framework of quaternary volcanic activity in italy (s.c., b.g., p.p.) the tyrrhenian sea is one of the most geologically complex areas in the world (faccenna et al., 2001b; cavazza et al., 2004; beltrando et al., 2010). the reasons for this complexity are mainly linked to its role in the convergence of the african and european plates, which starting from the cretaceous to the present time, has led to the formation of two orogenic belts (alpine and apennine chain) and several back-arc basins of progressively younger age moving from w to e in the western mediterranean (sartori, 2003). magmatic processes are integral part of this geodynamically complex region and punctuated all stages of its evolution. in the initial stages this activity was concentrated in the alps (e.g., conticelli et al., 2009b, 2010; alagna et al., 2010) along the margins of the colliding plates and, to a lesser extent, within the africa-adria plate. the last phase of this complex geodynamic magmatic pattern began in the upper eoceneoligocene and is still on-going. this is coeval with the formation of the apennine-maghrebian chain, and the opening of the western mediterranean basin (lustrino et al., 2011; di capua et al., 2016), and has therefore been referred to as “the apennine magmatism” (peccerillo, 2017). opening of slab tears and incipient slab detachment also occurred in the late evolution of the apennine orogen, favouring the channelling of intra-plate volcanism that mixed with the orogenic one during the final stage of vulture volcanism (e.g., faccenna et al., 2001a, 2001b, 2004; avanzinelli et al., 2008, 2009; conticelli et al., 2009b). the apennine orogen has been subject to backarc extension since the late miocene due to the rapid slab roll-back of the calabrian block (malinverno & ryan, 1986), which has produced two major extensional basins in the abyssal plain of the tyrrhenian sea, the vavilov and the marsili basins, located at north-west and southeast portions of the southern tyrrhenian basin, respectively (marani and gamberi, 2004). the opening of the marsili back-arc basin also coincides with the formation of the aeolian volcanic arc, whose spatial evolution is linked to the decoupling and roll-back of the slab beneath the calabrian arc (loreto et al., 2020). at the back of the eastward migrating apennine orogen intense extension occurred since the upper miocene (jolivet et al., 1998, and references therein). in the central tyrrhenian margin, the onset of extensional tectonics can be dated at late miocene, the age of syn-rift sedimentary sequences filling in the extensional basins located between the tolfaceriti and roccamonfina volcanoes (mattei et al., 2010). the tyrrhenian margin of southern italy, on the counterpart, has been mainly characterized by plio-quaternary back-arc extension, with the development of nw-se normal faults (acocella and funiciello, 2006); coeval nesw transverse systems are also present. despite the overall nw-se alignment of the quaternary volcanoes along the tyrrhenian margin, most of them formed where nw-se normal faults intersect transverse ne-sw tectonic lineaments which, thanks to the higher vertical depth with respect to the nw trending features, represent a preferential structure for magma uprising and fluids upwelling (acocella and funiciello, 2002). the volcanic edifices consist of poli-phase calderas and large ignimbrite plateaus, which identify vast areas with negligible topographic relief (vulsini, sabatini, the vulcano laziale the early edifice of the colli albani volcano, campi flegrei) and stratovolcanoes with summit calderas (e.g., vico, faete the intracaldera edifice of colli albani, roccamonfina and vesuvius). 223 the italian quaternary volcanism 3. the central italy quaternary volcanoes 3.1. tuscany (s.c., j.p.s.-b.) 3.1.1. general background the oldest potassic to ultrapotassic volcanic rocks of the central mediterranean region are found on the western margin of the tyrrhenian basin, distributed n-s (fig. 2), in corsica at sisco (14.1 ma; civetta et al., 1978), at capraia island (7.5-4.6 ma; gasparon et al., 2009) and at cornacya seamount (12.6 ma; mascle et al., 2001). these are leucite-free, lamproite-like, ultrapotassic rocks associated with shoshonitic and high-k calcalkaline volcanic rocks (conticelli et al., 2009a). following the rollback of the slab and the consequent opening of the tyrrhenian basin, the volcanism shifted diachronically eastward, from miocene to pliocene, from corsica to tuscany (fig. 2) (e.g., avanzinelli et al., 2009; conticelli et al., 2010, 2015a). in tuscany, lamproite like, leucite-free ultrapotassic rocks and associate shoshonitic and calc-alkalic volcanic rocks of ultimate mantle origin are distributed on both sides of the western shoreline of the italian peninsula (fig. 2a; e.g., peccerillo et al., 1987; conticelli & peccerillo, 1992; conticelli et al., 2009a, 2010, 2015; peccerillo, 2005, 2017), and in some cases these volcanic rocks are intimately associated, in space, but not in time, with crustal-derived rhyolitic to granitic rocks (peccerillo et al., 1987; conticelli et al., 2002, 2004, 2010; conte & dolfi, 2002). the oldest ultrapotassic to high-k calc-alkalic igneous rocks of the so called “tuscan magmatic province” (conticelli & peccerillo, 1992) are found at elba island, in the archipelago between italian peninsula and corsica with a 40ar/39ar age of 5.89 ma (conticelli et al., 2001). these were followed by the emplacement, in the mainland, of the val d’era lamproites made of the hypabissal minette of montecatini val di cecina, emplaced at 4.1 ma (k/ar; borsi et al., 1967), and lamproite-like “orendite” of orciatico (conticelli et al., 1992), of the latitic dykes at campiglia (conticelli et al., 2004), and in the latium region of the volcanic products of the tolfamanziana-ceriti dome complexes (fig. 2a) between 4.3 and 1.9 ma (e.g., evernden & curtis, 1965; fazzini et al., 1972; bigazzi et al., 1979; lombardi et al., 1974; villa et al., 1989). the quaternary volcanic rocks are instead found at radicofani, torre alfina, monte cimino, ponza island (monte la guardia) and in drills in the campania region. these leucite-free ultrapotassic, lamproite-like, to shoshonitic and calc-alkalic rocks were emplaced between 1.3 and 0.85 ma (e.g., evernden & curtis, 1965; nicoletti, 1969; pasquarè et al., 1983; sollevanti, 1983; d'orazio et al., 1991; laurenzi et al., 2015; conte et al., 2016; nappi et al., 2022). 3.1.2. torre alfina monogenetic volcano the torre alfina volcano (fig. 2b) is located a few kilometers north of the vulsinian district (fig. 2; 42° 45’19”n-11°56’41”e) and consists of a few tiny lava flows erupted from a small volcanic centre, and a small neck cropping out north of torre alfina castle. torre alfina is a monogenetic volcano characterised mainly by lava flows and minor strombolian activity (conticelli, 1998). the torre alfina volcanic rocks rest directly on the sedimentary substratum of the monte cetona horst. the torre alfina lava flows were erupted at the top of the hill and flowed partly into the canyon formed by the paglia river. field characteristics indicate that they had low viscosities, and some lava tunnels may be recognised in the eastern part of the vent. two slightly different types of lava can be also recognised. they were emplaced contemporaneously. they have different colours, vesiculation, and porphyritic indexes. the most mafic lava (type-a, fig. 2b) is dark grey, almost aphyric, and fig. 2 a) distribution of ultrapotassic rocks in the central italian region revealing the location the torre alfina, radicofani and monte amiata volcanoes (spots within the large rectangular shapes) and the distribution of the major magmatic potassic and ultrapotassic events. red spots and areas (kamafugites) and dark green spots (lamproites) mark the location sites of the most extreme endmembers of the orogenic magmatic activity. modified after conticelli et al. (2010, 2013, 2015a) and günther et al. (2023); b): geological sketch map of the torre alfina volcano. legend: 1) cretaceous carbonaceous and argillaceous sedimentary rocks; 2) blocky olivine-latite lava flows, type b; 3) low viscosity olivine-latite lava flows, type b; 4) low-viscosity olivine-latite lava flows, type a; 5) lapilli and scoriae; 6) leucite-tephrite to leucite-phonolite vulsini lavas; 7) leucite-phonolite to leucite-trachyte vulsini pyroclastic rocks. redrawn after conticelli (1998) and avanzinelli et al. (2017). 224 branca s. et al. contains abundant green ultramafic microxenoliths 2-4 cm in diameter (conticelli & peccerillo, 1990), as well as a few lower crustal xenoliths of variable size (5-10 cm) and nature (orlando et al., 1994). type-b lava is the most widely represented at torre alfina volcano. it is dark grey to light grey in color, with a variable porphyritic index and vesiculation, showing some flattened vesicles of a few centimeters in length. type-b lavas contain abundant crustal xenoliths of variable size (2-30 cm), some large (3-20 cm) magmatic mica-rich inclusions, and rare green ultramafic xenoliths. torre alfina lavas are leucite free ultrapotassic rocks of lamproitic nature of ultimate mantle origin generated by low degrees of partial melting of a veined mantle wedge at low xco2 conditions (conticelli et al., 2015a). 3.1.3. radicofani monogenetic volcano the radicofani volcano is a monogenetic volcano lying within the central portion of the radicofani basin, few kilometers north of the torre alfina volcano (fig. 2b). the radicofani basin represents the southernmost branch of the sienaradicofani graben, one of the most important post -orogenic extensional tectonic features of the northern apennine (e.g., pasquaré et al., 1983; acocella et al., 2002; bonini & sani, 2002). the radicofani monogenetic volcano is formed by a 90 m-high wellpreserved volcanic neck, with remnants of a cinder cone and of a lava lake at its top, and by several lava flows (fig. 3). the lava flows are scattered around the neck and lie on top of the pliocene marine sediments (liotta, 1996; disperati & liotta, 1998; ghinassi & lazzarotto, 2005; conticelli et al., 2011). the original volcanic edifice was made up by a cinder cone a few hundred meters high. today only a thin layer of red scoriae is preserved on the edge of the top of the neck, just west of the homonym castle. the top of the neck is made up of red vesicular lava that becomes dense and grey downward (fig. 3). columnar jointing is present in the middle and lower portions of the neck in grey and dark grey aphyric to subaphyric lavas. oxidised septa dividing the different portions of the neck can also be observed. rocks of different portions of the volcano yield radiometric ages in the range between 1.315 ma and 1.08 ma (e.g., barberi et al., 1971; pasquaré et al., 1983; d’orazio et al., 1991), but the uncertainty in the age determination is relevant. the radicofani volcanic rocks have significant compositional variations from basaltic andesite (high-k calcalkaline), at the bottom of the neck to ultrapotassic shoshonite for the lava-lake lavas, scoria and lava flows. the overall volcanic rocks show aphyric to sub-aphyric textures with small euhedral phenocrysts of olivine set in a microcrystalline matrix made of clinopyroxene, sanidine, ilmenite, and magnetite. rare microliths of orthopyroxene are found in the groundmass of calc-alkaline samples. chemical and isotopic variations along the necks are thought to be a primary feature due to incremental partial melting of a veined mantle wedge under conditions of low xco2, favouring the genesis of silica-saturated, leucitefree, ultrapotassic magmas (conticelli et al., 2011). 3.1.4. the monte amiata: a quaternary “hybrid” volcano the monte amiata volcano is a small linear late pleistocene volcano located some tens of kilometers north of the vulsini district (fig. 1) and few kilometers west of radicofani monogenetic volcano (figs. 2a and 4). it is found where the roman and tuscany magmatic provinces overlap in space but not in time (conticelli et al., 2004, 2010). the monte amiata volcano produced a sequence of several viscous lava flows and exogenous domes outpoured from nne-ssw tectonic structures (fig. 2a), both hosting abundant cognate magmatic enclaves (e.g., ferrari et al., 1996; marroni et al., 2015). the volume of magma outpoured is smaller than the amount of magma erupted in roman volcanoes, but consistently larger than that produced by tuscan volcanoes (conticelli et al., 2009a; 2010). according to laurenzi et al. (2015) the onset of magmatic activity was at 305 ka with final lavas emplaced at 230 ka. lavas and enclaves are characterised by high-k calc-alkaline to shoshonitic affinities ranging in composition with time from trachydacites to trachyte, latite, and olivine latite, with a progressive increase of the amounts of mafic enclaves. monte amiata rocks, lavas and enclaves, are leucite free, with phenochrysts of olivine, confined to the most mafic terms, biotite, plagioclase, sanidine, clinopyroxene and orthopyroxene, set in a microcrystalline to glassy matrix. finegrained magmatic enclaves range from porphyritic to aphyric and invariably display chilled margin texture, ranging in compositions from trachybasaltic to shoshonitic and latitic. petrographic and compositional characteristics of fine-grained magmatic enclaves suggest that they were molten at the time of inclusion by the host trachytic magma. their chemical, mineralogical, and isotopic characteristics are strongly suggestive of genesis by mixing/mingling between a resident trachydacitic mag fig. 3 (a) scoria and lapilli of the cinder cone containing the lava lake at the roof of the neck; (b) reddish shoshonitic lava forming the lava lake at the roof of the neck; (c) oxidised septum that separates shoshonitic lava of the upper neck from the high potassium basaltic andesitic lava of the lower neck (redrawn after conticelli et al., 2011; avanzinelli et al., 2022). 225 the italian quaternary volcanism ma, derived by crystal fractionation from a high-k calcalkaline basaltic-andesitic magma (tuscan type), similar in composition to the radicofani magma and a younger roman-type, silica-undersaturated, basanitic magma (conticelli et al., 2015b, and references therein). 3.1.5. the other leucite-free volcanoes in latium and campania other leucite-free ultrapotassic associated to shoshonitic and calc-alkalic volcanic rocks of ultimate mantle origin were emplaced along the tyrrhenian border of the italian peninsula in a period of time between 2 and 1 ma (fig. 2) at monte cimino volcanic complex, in northern latium underlying the vico volcano (conticelli et al., 2013), at tolfa-maziana-cerite volcanic complexes, in central latium underlying the sabatini volcanoes (bertagnini et al., 1995), offshore in the pontine archipelago, in southern latium (conte & dolfi, 2002; cadoux et al., 2005), and in the neapolitan area, in the central campania, beneath the campi flegrei volcanoes (albini et al., 1980; barbieri et al., 1979; brocchini, 1999). in most of these localities the older leucite-free igneous rocks preceded by a few hundred thousand years the younger strongly silica-undersaturated, meliliteto leucite -bearing roman volcanic rocks (conticelli et al., 2010, 2015a). 3.2. latium and northern campania (d.m.p., s.c., j.p.s.-b., m.g. b.g., g.g., f.m., g.s.) 3.2.1. general background the quaternary (middle pleistocene to present) ultrapotassic magmatism of central italy fits into the geodynamical context of the tyrrhenian back-arc extension related to the ne retreat of the west-directed adriatic slab (malinverno & ryan, 1986; conticelli & peccerillo, 1992; faccenna et al., 2001a; acocella & funiciello, 2006). this originated a nw-se trending volcanic belt extending between the tyrrhenian sea coast and the apennine orogen from southern tuscany, through latium and campania. defined as the roman comagmatic region since washington (1906), this volcanic region is known worldwide for its peculiar potassic and strongly silicaundersaturated and meliliteto leucite-bearing ultrapotassic magma: feeder magmas display a wide compositional range and multiple differentiation trends, ranging from kbasalts to k-foidites, phonolites and trachytes, and even k-rhyolites. based on isotope geochemistry, the roman, ernici-roccamonfina and campanian districts are distinguished (peccerillo, 2005, 2017; conticelli et al., 2010). here, we focus on the roman province volcanoes, i.e., from nw to se, vulsini, vico, sabatini and colli albani, as well as on the volsci volcanic field (formerly erroneously defined ernici volcanoes) and roccamonfina volcano, which belong to the ernici-roccamonfina districts (fig. 5). these volcanoes show a full spectrum of fig. 4 geological sketch map of the amiata region. legend: 1) sedimentary sequences of the ligurid units; 2) pliocene marine sediments; 3-4) radicofani volcano, neck and dismembered lavas, respectively; 5-14) monte amiata volcano 5-6) basal trachydacitic lava flows (6); 7-11) trachytic domes and lava flows; 13) latitic lava flows; 14) olivine latitic lava flows; 15) quaternary alluvial deposits (redrawn after conticelli et al., 2015a,b; laurenzi et al., 2015; marroni et al., 2015). 226 branca s. et al. eruptive dynamics and related morphologies, ranging from small-scale strombolian and phreatomagmatic events from monogenetic centers (scoria cones, maartuff rings and tuff cones), with associated effusive activity, to highly explosive plinian and pyroclastic flow-forming events, often related to caldera collapses. major volcanic districts with a dominant areal character (i.e., vulsini and sabatini), characterized by multiple caldera depressions and networks of monogenetic eruptive centers, alternate with essentially central volcanoes, such as stratovolcanoes with summit calderas and subordinate eccentric activity (i.e., vico and roccamonfina), or polygenetic caldera volcanoes with ignimbrite plateaux (i.e., vulcano laziale in the colli albani district). in some cases, central volcanic edifices with summit calderas, such as latera and montefiascone (vulsini), sacrofano (sabatini) and faete (colli albani), superimposed in time and space with areal volcanism. quite peculiarly, the volsci volcanic field consists of small-scale, isolated or locally clustered, eruptive centers. the onset of potassic volcanism is documented by the oldest exposed products in the volsci volcanic field that date back to at least ca. 760 ka (boari et al., 2009b; cardello et al., 2020; marra et al., 2021) (fig. 6). however, evidence of even earlier activity in the roman area is provided by ca. 750-810 ka tephra layers found in the tiber river delta (marra et al., 2014; fig. 6). since ca. 600 ka, the vulsini, sabatini, colli albani, volsci and roccamonfina volcanoes were all simultaneously active (fig. 6) (e.g., marra et al., 2003; sottili et al., 2004; rouchon et al., 2008; boari et al., 2009b; conticelli et al., 2010; palladino et al., 2010; soligo & tuccimei, 2010), followed at ca. 415 ka by the onset of volcanic activity at vico (pereira et al., 2020). 3.2.2. vulsini volcanic district (ca. 590-111 ka) the northernmost and largest (ca. 2200 km2) volcanic district in the roman province developed along the southern termination of the nnw-sse trending miocenepliocene siena-radicofani graben from the superposifig. 5 location and geological sketch of the quaternary peri-tyrrhenian potassic volcanoes of central italy. 227 the italian quaternary volcanism tion of five major volcanic complexes (or lithosomes), partially overlapping in space and time: paleovulsini, vulsini fields (formerly defined as southern vulsini), bolsena-orvieto, montefiascone and latera (vezzoli et al., 1987; palladino et al., 2010 and reference therein; figs. 7 and 8). the most prominent volcano-tectonic feature in the district is the wide caldera depression hosting lake bolsena, which is intersected, respectively to the w and se, by the latera and montefiascone central volcanoes, featuring collapse calderas (nappi et al., 1991; acocella et al., 2012). the whole area is dotted with several tens of monogenic cones and craters, either isolated (e.g., lagaccione maar, tuff cones of bisentina and martana islands in lake bolsena) or clustered (e.g., the valentano scoria cones on the se rim of latera caldera) or located along volcano-tectonic lineaments (e.g., the n-s scoria cone alignment along the eastern rim of bolsena caldera). overall, volcanic activity spanned a broad spectrum of eruptive styles, intensities and magnitudes, ranging from small-scale explosive (strombolian and hydromagmatic) and effusive eruptions from monogenetic centers, up to plinian and pyroclastic flow, caldera-forming, events (sparks, 1975; conticelli et al., 1987; nappi et al., 1994; palladino & valentine, 1995; palladino & agosta, 1997; palladino & simei, 2005; palladino et al., 2014). figure 9 shows an example of interbedded volcanic units from different source vents and their unconformity boundaries. in the following, the five lithosomes are briefly described: 1) the paleovulsini lithosome groups the early eruptive products of vulsini (ca. 590 to <490 ka; nicoletti et al., 1981; vezzoli et al., 1987; cioni et al., 1989; nappi et al., 1995), which consist of trachytic welded pyroclasticflow deposits (basal ignimbrites or nenfri, ca. 550-505 ka) and associated plinian pumice fall horizons exposed at the periphery of the district on top of the sedimentary substrate. an early collapse caldera possibly related to the basal ignimbrites, inferred from the bolsena lake bathymetry and deep drillings, controlled the location and style of the following eruptive activity, which followed as areal volcanism (vulsini fields lithosome); 2) the vulsini fields (former southern vulsini complex; fig. 6 temporal distribution of the middle pleistocene volcanic activity from the peri-tyrrhenian potassic volcanic systems, plotted against the lr04 benthic stack record (lisiecki & raymo, 2005). data source: vulsini: palladino et al. (2010), marra et al. (2020a); vico: perini et al. (2004), pereira et al. (2020); sabatini: sottili et al. (2010), marra et al. (2014, 2020b); colli albani: marra et al. (2009); volsci: boari et al. (2009), centamore et al. (2010), marra et al. (2021); roccamonfina: giannetti (1996a, 1996b), giannetti & de casa (2000), rouchon et al. (2008), scaillet et al. (2008). 228 branca s. et al. fig. 7 geological sketch map of the vulsini volcanic district (modified after palladino et al., 2010). the boundaries of the sheet no. 344tuscania of the 1:50,000 geological map of italy (carg project) are also shown. towns and other localities: a, acquapendente; b, bolsena; c, canino; f, farnese; g, grotte di castro; m, montefiascone; o, orvieto; p, pitigliano; s, sovana; so, sorano; t, tuscania; ta, torre alfina; cm, capodimonte; lr, la rocchetta; ps, piansano. 229 the italian quaternary volcanism vezzoli et al., 1987) is a composite lithosome consisting of a gently sloping volcanic plateau, extending throughout the whole district, which developed by long-lasting (ca. 490-111 ka) effusive and subordinate explosive activity from a network of scattered eruptive centers. volcano-tectonic lineaments related to the early paleovulsini caldera might have favoured the eruption of poorly differentiated, small magma batches from multiple source vents around the present lake bolsena depression. although this areal volcanism largely preceded the onset of central explosive activities at latera and montefiascone at ca. 280 ka (nappi et al., 1995; brocchini et al., 2000), it was also contemporaneous and even followed the montefiascone and latera explosive climax until the waning phases of activity in the district. in particular, the monte bisenzio spatter cone represents the most recent volcanic product dated so far at vulsini (ca. 111 ka; marra et al., 2020a). in lack of evidence of major caldera-forming eruptions that could explain the size of the bolsena depression, walker (1984) and cole et al. (2005) classified it as a downsag caldera end-member. the relationships among eruptive sources and volcano-tectonic lineaments may suggest that the prolonged magma drainage during the vulsini fields activity was accompanied by incremental caldera growth that extended the early paleovulsini caldera collapse and eventually resulted into the wide depression hosting lake bolsena (acocella et al., 2012); 3) the bolsena-orvieto lithosome includes lava and pyroclastic successions that are mainly exposed in the northeastern sector of vulsini, from lake bolsena to the tiber valley, including a series of plinian fall deposits fig. 8 sketch of the legend of sheet 344-tuscania (after palladino et al., 2010, modified), where representative lithostratigraphic volcanic units are grouped into lithosome units and organized in the framework of the unconformity-bounded stratigraphic (ubs) units recently defined for the volcanic and tyrrhenian coastal areas of northern latium. note that major ubs unit boundaries correlate to evennumbered oxygen isotope stages, corresponding to low-stands of sea level (δ18o curve after shackleton et al., 1990; shackleton, 1995). 230 branca s. et al. fig. 9. field pictures of the vulsini volcanic successions. (a) la rocchetta locality (6 km sw of capodimonte): major pyroclastic units of latera (i.e., canino, sorano, grotte di castro formations) on top of a lava flow from the vulsini fields and intervening stratigraphic discontinuities, such as paleosols (e.g., d1, p) and high-relief erosional surfaces (e.g., d2, d3, d4), related to ubs boundaries of different rank (see fig. 8). note the u-shaped channel (d2) mantled by a thin ash-fall layer and filled by pyroclastic current deposits of the sorano formation (flow direction toward the page; d-example of flow unit boundary). (b) 5 km sw of montefiascone: interbedded vulsini fields and montefiascone volcanic successions, showing the slightly undulating erosional surface bounding the barca di parma (bp) and fiume fiora (ff) synthems, and local stratigraphic discontinuities representative of temporal hiatuses in the eruptive activity, as evidenced by steep erosional channels (black arrow) or paleosols (p). (c) close-up of the upper part of the canino formation at la rocchetta, showing the depositional boundary between temporally closely spaced pyroclastic flow and fall units, topped by the canino-farnese inter-eruptive paleosol. 231 the italian quaternary volcanism (nappi et al., 1994, 1995) and the interbedded ca. 332 ka orvieto-bagnoregio ignimbrite related to a major caldera-forming event (palladino et al., 2014; marra et al., 2019; palladino & pettini, 2020); 4) the montefiascone lithosome, se of lake bolsena, consists of a central volcanic edifice cut by a nearly circular polygenetic caldera, ca. 3 km across. the onset of activity (<286 ka), broadly contemporaneous with latera, is represented by the lithic-rich montefiascone basal ignimbrite (nappi & marini, 1986), a hydromagmatic event related to an early stage of caldera collapse; 5) latera is a gently sloping, central volcanic edifice (at least 30 km across) located in the western part of vulsini (fig. 9). its climactic activity (ca. 253-177 ka; monaco et al., 2022a and reference therein) produced widespread plinian fall (palladino & agosta, 1997) and ash-pumice flow deposits (sparks, 1975; palladino & valentine, 1995; palladino & giordano, 2019; valentine et al., 2019), resulting in the latera-vepe nested caldera system (9 km by 7 km across) through multiple collapse stages (e.g., nappi, 1969; sparks, 1975; barberi et al., 1984; vezzoli et al., 1987; nappi et al., 1991; palladino & simei, 2005). in particular, the sovana and onano eruptions, which emplaced typical lag breccia deposits, are identified as major caldera-forming events (palladino & simei, 2005; palladino et al., 2014). the late volcanic activity was characterized by effusive (e.g., fig. 10 (a) geological sketch map of the cimino volcanic complex (tuscan magmatic province, avanzinelli et al., 2009; conticelli et al., 2010, 2015a). legend: 1) sedimentary substrate; 2) domes and lava flows of the i cimino phase; 3) pyroclastic flows of ii cimino phase; 4) latitic to trachitic lava flows of the iii cimino phase; 5) olivine latitic to shoshonitic lava flows of the iv cimino phase; 6) roman-type leucite -bearing vico volcanic rocks (roman magmatic province); 7) quaternary fluvial deposits; (redrawn after perini et al., 1997, 2004; conticelli et al., 2007, 2010; 2013, 2015a). (b) geological sketch map the vico volcano. legend: e) caldera rim; 8) macigno flysch; 9) allochtonous flysch; 10) post-orogeny pliocene-pleistocene marine sediments; 11-13) cimino dome complex (1300-900 ka): 11) lamproitic lava; 12) rhyodacitic domes; 13) rhyodacitic peperino tipico ignimbrite; 16-14) lago di vico synthem (second period; the earlier rio ferreira synthem is not representable at this map scale): 14) stratocone building leucite-bearing lavas; 15) caldera forming phonolitic ignimbrites; 16) carbognano phreatomagmatic ignimbrite; 17) monte venere lithosome: post-caldera scoria cones (third period); 18) travertine; 19) holocene alluvial and lacustrine deposits; (c) geological sketch section through the monte cimino (1.3-0.9 ma) and vico (0.45-0.05 ma) nested volcanoes (redrawn after conticelli et al., 2013; avanzinelli et al., 2017). 232 branca s. et al. the ca. 157 ka shoshonitic selva del lamone lava plateau), strombolian and phreatomagmatic eruptions from intraand peri-caldera monogenetic centers. the vulsini volcanics span a full range of potassic rock types, from the least differentiated (i.e., k-basalts, trachybasalts, basanites, and tephrites), which mostly characterize lava flows and plateaus, as well as strombolian and hydromagmatic products, to the most differentiated ones (i.e., phonolites, and trachytes), typical of plinian pumice-fall and ash-pumice flow deposits from major fig. 11 -variation of the silica content upsection within the vico α and vico β plinian deposits and the minor pre-vico α and post-vico β units (modified from pereira et al., 2020). 233 the italian quaternary volcanism explosive eruptions (conticelli et al., 1987, 1991; nappi et al., 1994; palladino & agosta, 1997; palladino et al., 2010, 2014 and reference therein). in particular, the montefiascone lavas (e.g., from the circum-caldera orto piatto eruptive center; ca. 226 ka; nappi et al., 1995) display peculiar compositional features (i.e., high cao and mgo and low sio2, al2o3 and alkali contents) and are recognized among the most primitive rock types in the vulsini district and in the whole roman province as well (conte et al., 2009). in distal setting, the activity of the vulsini volcanic district is particularly well documented for the latera stage (ca. 255-157 ka) in fucino basin, central italy (monaco et al., 2021). from the same basin, several tephra layers originated from vulsini have been also found in the interval 430-300 ka (e.g., orvietobagnoregio unit of 335 ka; leicher et al., 2023; monaco et al., 2021), while activity of the paleovulsini is possibly documented in lake ohrid (leicher et al., 2019; 2021). 3.2.3. cimino (ca. 1.1-0.8 ma) and vico (ca. 415-95 ka) on the basis of morphological, geological, and mineralogical data the cimino and vico volcanoes (fig. 10) represent two distinct edifices active in different times, but fed by the same plumbing system (e.g., perini, 1997; perini et al., 1997, 2000, 2003, 2004; peccerillo, 2005; conticelli et al., 2010, 2013, 2015a; ). according to peccerillo et al. (1987) the cimino volcanic complex, active during the early pleistocene, belongs to the tuscan magmatic province, whilst the nested and younger vico stratovolcano, active during the late pleistocene, belongs to the roman magmatic province. the cimino volcanic complex is the oldest edifice of the cimino-vico area, and it is a relatively simple volcano with an evolution through four main phases (conticelli et al., 2013) in a short time span from 1.35±0.08 to 0.94±0.20 ma (e.g., evernden & curtis, 1965; nicoletti, 1969; borghetti et al., 1981). the cimino volcano is made up of: i) an initial alignment of trachydacitic to trachytic cryptodomes along a nw-se trend (auctor. “peperino delle alture”); ii) two welded pyroclastic flow units, outpoured when the activity was concentrated in the central part of the volcano (auctor. “peperino tipico”); iii) lava flows of the monte cimino cone; iv) final mafic lava flows unit (e.g., puxeddu, 1971; lardini & nappi, 1987; perini et al., 2003; cimarelli & de rita, 2006a,b; laberge et al., 2006, 2008; conticelli et al., 2013; nappi et al., 2022). the cimino volcanic rocks are invariably leucite-free ranging with time from trachydacite, to trachyte, latite, olivine-latite, and shoshonites. details on mineralogical and petrographic features are provided in perini et al. (2003) and conticelli et al. (2013). after a hiatus of some hundreds of thousands of years, renewal of volcanic activity occurred in the area, at 450 ka, few kilometers southwest of the monte cimino with eruption of roman-type, silica-under-saturated, leucite-bearing magmas (fig. 10). the vico volcano was built in the form of a conic stratovolcano cut by a summit polygenetic caldera (perini et al., 1997, 2004). postcaldera activity, subordinate in volume, both within and on the n and w edges of the caldera do occur (fig. 10b; perini & conticelli, 2002; perini et al. 1997, 2004). vico volcanic rocks were strong to mild silica-undersaturated, leuciteto plagioclase-leucite-bearing generated by partial melting of a lithospheric mantle wedge under high xco2 conditions. the eruptive history of the vico volcano is subdivided into three periods and corresponding lithosomes (perini et al., 2004; conticelli et al., 2013): 1) rio ferriera synthem (sensu perini et al., 2004), involving an early effusive period, alternating with explosive phases at ca. 415-400 ka that produced the vico α and vico β plinian fall markers (cioni et al., 1987; pereira et al., 2020); 2) lago di vico synthem, involving the build-up of the main stratovolcano by essentially effusive activity (ca. 305-258 ka), followed by a climactic, caldera-forming, explosive phase at ca. 250-144 ka that produced ignimbrites a, b, c (also known as tufo rosso a scorie nere vicano) and d (locardi, 1965; bertagnini & sbrana, 1986), corresponding to the farine, ronciglione, sutri and carbognano formations (perini et al., 2004; bear et al., 2009a,b); 3) monte venere synthem (ca. 138-95 ka), characterized by phreatomagmatic and strombolian-effusive activities from periand intra-caldera monogenetic centers. vico α and vico β are geochemically peculiar within the peri-tyrrhenian volcanism. in fact, in addition to the usual trachy-phonolitic ones, the juvenile fraction of the deposits of both eruptions contains rhyolitic pumice clasts (fig. 11), which represent a puzzling exception among the quaternary potassic volcanoes of central italy. isotopic and trace element data indicate an origin of these rhyolitic magmas by fractional crystallization processes (perini et al., 2004), occurred at unusually highpressure conditions: the rhyolitic glasses in pumice clasts show, indeed, high volatile contents (h2o ca. 5-7 wt%) and are in equilibrium with amphibole (monaco, 2022). the deep level of the vico α and vico β pre-eruptive magma systems is consistent with the wide dispersal of the fallout products and the lack of co-eruptive pyroclastic currents associated with caldera-forming processes. conversely, the tufo rosso a scorie nere vicano (ca. 150 ka; laurenzi & villa, 1987) is related to the main caldera collapse at vico (bear et al., 2009a,b; palladino et al., 2014). the eruption succession includes: i) a basal plinian fall horizon containing whitish sub-aphyric pumice, related to a central feeder conduit; ii) black spatterbearing, coarse lithic-rich, co-ignimbrite lag breccias, related to developing ring faults during caldera collapse; iii) red tuff with leucite-bearing black scoria, that is the main pyroclastic flow deposit emplaced at the eruption climax, extending with remarkable continuity as far as 25 km from the vent, over an area of 1200 km2. the facies architecture and the variation patterns of juvenile textural features and glass compositions, along with mineral chemistry, reveal a magma chamber characterized by thermal and volatiles gradients (which reflect in crystal concentration gradients) and changing magma withdrawal dynamics in the course of a typical caldera-forming event (bear et al. 2009a; palladino et al., 2014). owing to their peculiar rhyolitic components and/or wide dispersal, vico α and vico β and the vico ignimbrites c and b are key stratigraphic markers for regional and ultra-regional correlations (cioni et al., 1987; pereira et al., 2020; monaco et al., 2021; iurino et al., 2022), as 234 branca s. et al. far as lake ohrid, albania-north macedonia (leicher et al., 2021). 3.2.4. sabatini volcanic district (ca. 810-70 ka) the sabatini volcanic district extends over an area of ca. 1,800 km2 north of rome (fig. 12). volcanism was dominated by explosive activity ranging through a broad spectrum of intensities and magnitudes, from strombolian and phreatomagmatic eruptions from monogenetic centers to plinian and pyroclastic flow-forming events associated with caldera collapses (sottili et al., 2004, 2010a; marra et al., 2014, 2016). today, the main landforms in the area are represented by the bracciano caldera, hosting a lake ca. 9 km in diameter, and by the 6 x 4 km sacrofano caldera to the east. although quite subordinate volumetrically, a number of monogenetic tuff rings and scoria cones that postdate the main calderaforming events are either clustered or scattered in the northern area of the district and between the bracciano and sacrofano calderas (sottili et al., 2010a; valentine et al., 2015). eruptive activity mostly took place in the 0.6-0.1 ma time span, although older widespread plinian fall deposits of uncertain source (yet tentatively attributable to a sabatini paleo-activity) were also found in drill sites along the tiber valley and dated at ca. 810-614 ka (karner et al., 2001). conventionally, the sabatini activity is divided into three main phases (cioni et al., 1987, 1993; de rita et al., 1993, 1996; barberi et al., 1994; conticelli et al., 1997; karner et al., 2001; sottili et al., 2004, 2010, 2012, 2019; masotta et al., 2010): 1) early phase from the morlupo (ca. 589-500 ka) and southern sabatini (ca. 500-400 ka) source areas, respectively to the east and south of the present lake bracciano, characterized by widespread pyroclastic flows and subplinian to plinian fallout (vei 3-5). during this phase of activity, the main eruptions of the ca. 548 ka tufo giallo della via tiberina and the ca. 449 ka tufo rosso a scorie nere sabatino occurred, the latter being the volumetrically most important, calderaforming event in the whole activity history of sabatini (sottili et al., 2004; 2010; masotta et al., 2010; marra et al., 2014; palladino et al., 2014); 2) intermediate phase of effusive and explosive activity (ca. 400-200 ka) from lake bracciano and sacrofano source areas, marked by two major caldera-forming eruptions, respectively the ca. 310 ka tufo di bracciano and the ca. 285 ka tufo giallo di sacrofano; 3) late eruptive phase (ca. 150-70 ka), dominated by phreatomagmatic and subordinate strombolian and effusive activities from monogenetic and polygenetic tuff rings and scoria cones in the central area of sabatini (sottili et al., 2012; valentine et al., 2015), mostly between the bracciano and sacrofano calderas (e.g., baccano, martignano and stracciacappa centers). compositionally, the sabatini volcanics cover a fig. 12 sketch geological map of the sabatini volcanic district (after sottili et al., 2010a), showing the areal distributions of the main activity periods. insets show the locations of the sabatini and the other volcanic districts of the roman province, central italy. legend: 1sedimentary terrains; 2-m.ti ceriti-tolfetano-manziate lava domes (pliocene); 3morlupo phase products (0.6-0.5 ma); 4southern sabatini products (0.5-0.4 ma); 5bracciano caldera products (0.3-0.2 ma); 6sacrofano caldera products (0.3-0.2 ma); 7vico volcano (0.40.1 ma); 8sabatini late activity (< 0.15 ma); 9scoria cones; 10maars; 11caldera rims; 12buried source areas. 235 the italian quaternary volcanism wide spectrum of potassic rock types, ranging from trachybasalts to trachytes and phonolites (conticelli et al., 1997, 2010; peccerillo, 2005; sottili et al., 2019). marra et al. (2020b) highlighted a noticeable parallelism in time and eruption magnitude between sabatini and colli albani during most of their lifetime, and suggested a common regional tectonic trigger, such to define them twin volcanic systems. the explosive activity of the sabatini volcanic district is well documented in distal setting. the most widespread unit is fall a (~500 ka) of the morlupo phase, found in central-southern italy intermountain basins (sulmona, mercure and acerno; giaccio et al., 2014; petrosino et al., 2014; di rita & sottili, 2019) and lake ohrid (leicher et al., 2021). many other tephra layers spanning the interval 550-120 ka, of either well identified or supposed sabatini origin, have been found in fucino and acerno basins, lake monticchio and even lake ohrid (wulf et al., 2012; giaccio et al., 2012; 2017a, 2019; petrosino et al., 2014; monaco et al., 2021; 2022a; leicher et al., 2023). tephra layers with sr isotope composition and age comparable to the putative sabatini paleo-activity (~615-810 ka) have been found in the sulmona basin (giaccio et al., 2013b; 2015; sottili et al., 2019), although their attribution to the sabatini volcanic district is still uncertain. 3.2.5. colli albani volcanic district (ca. 608-36 ka) following a poorly documented early activity period, the colli albani volcanism took place in three main phases marked by different eruptive mechanisms and magma volumes (de rita et al., 1988, 1995b; giordano et al., 2006; fig. 13): 1) the climactic activity period, known as tuscolanoartemisio phase (de rita et al., 1988) or, referring to the evolution of the edifice, as vulcano laziale caldera complex (giordano & the carg team, 2010), produced at least five subsequent eruptive cycles, dominated by large mafic and caldera-forming ignimbrites, in the ca. 561-351 ka time span (karner et al., 2001; marra et al., 2009), alternated with effusive and mild explosive activity. strikingly, large-volume (up to several tens of km3) pyroclastic flows were fed by k-foiditic magmas with sio2 as low as 42 wt%, e.g., during the early trigoria-tor de’ cenci and palatino “pisolitic tuff” eruptions and the main ca. 456 ka pozzolane rosse and ca. 365 ka villa senni caldera-forming eruptions (freda et al., 1997, 2011; palladino et al., 2001; boari et al. 2009a; marra et al., 2009; vinkler et al., 2012; gaeta et al., 2016); 2) the faete phase (de rita et al., 1988), during which the tuscolano-artemisio peri-caldera ring fracture system and the intra-caldera faete stratovolcano were built (giordano & the carg team, 2010), occurred at ca. 308-250 ka (marra et al., 2003) and was characterized mainly by strombolian and effusive activities; 3) following a ca. 50 kyr-long dormancy, the late hydromagmatic phase (ca. 200-36 ka; marra et al., 2003, 2016; freda et al., 2006; giaccio et al., 2007, 2009), or via dei laghi lithosome (giordano & the carg team, 2010), was dominated by maar and tuff ring forming eruptions (e.g., ariccia, nemi, valle marciana, laghetto or giuturna, albano). in particular, the albano polygenetic maar (ca. 69-36 ka) hosted the most recent and energetic activity (giordano et al. 2002; freda et al., 2006; giaccio et al., 2007; de benedetti et al., 2008). the age of the last eruption at colli albani has been a matter of debate (see the above references and soligo & tuccimei, 2010 for a review). a wide data-set of accurate 40ar/39ar dating consistently indicates that the last documented eruptive event occurred at the albano maar at ca. 36 ka (marra et al., 2003; giaccio et al., 2007, 2009), in spite of younger ages reported in the literature (e.g., ca. 26 ka; villa et al., 1999) that are affected by stratigraphic inconsistencies and/or methodological uncertainties. in addition, a series of lahar deposits (tavolato formation) have been attributed to the repeated overflows of the lake albano and possibly associated with intrusion-triggered limnic eruptions (funiciello et al., 2003; de benedetti et al., 2008), although the occurrence and exact age of these events, possibly extending into the holocene, has been a matter of controversy (marra & karner, 2005; giaccio et al., 2007, d’ambrosio et al., 2010). on these grounds, bv considering the long-lasting quiescence periods occurred in the past (ca. 40 kyr; marra et al. 2004), it cannot be excluded that colli albani can be potentially active (de rita et al., 1995a; marra et al., 2016), also in light of the several geophysical (chiarabba et al., 1997) and geochemical (carapezza et al., 2010) indicators of volcanic unrest. although the colli albani rock-types span the tephrite, phonotephrite and k-foidite fields of the tas classification diagram, they show invariably, regardless of eruption size, a leucititic mineral assemblage. the latter is characterized by the virtual absence of feldspars, with a few exceptions in the groundmass of olivine-bearing lavas, and in glass-bearing juvenile pyroclasts formed at high cooling rates (trigila et al., 1995; gaeta, 1998; gaeta & freda, 2001; gaeta et al., 2006, 2016; giordano et al., 2006; boari et al., 2009a; marra et al., 2009; gozzi et al., 2014). the peculiar magma differentiation trend, leading to k-foiditic magmas with sio2 contents <50 wt%, has been explained by the assimilation of sedimentary carbonate. this process allows the establishment of co2rich conditions in the colli albani magmas and reduces the stability fields of olivine and phlogopite in favour of clinopyroxene and leucite (gaeta et al., 2000, 2009, 2021; freda et al., 2008; di rocco et al., 2012). the anomalous highly explosive behaviour of sio2-poor magmas at colli albani has also been attributed to co2 entrainment in the pre-eruptive system due to magmacarbonate wall rock interaction at supra-crustal levels (freda et al., 1997, 2011; sottili et al., 2010b; cross et al., 2014). an alternative hypothesis suggests that the main location for magma-carbonate fluids interaction, controlling both the peculiar line of descent and the explosivity, is within the metasomatized mantle source (boari et al., 2009a; jorgenson et al., 2020). the uncommon lithology and k-foiditic composition and other peculiar features of the colli albani tephra (e.g., the 87sr/86sr time-dependent variability; gaeta et al., 2016) make them among the most distinctive markers in the framework of the central mediterranean tephrostratigraphy (giaccio et al., 2013a). the pyroclastic products of the main activity phase of colli albani (ca. 561-351 ka), as well as of the late hydromagmatic phase (ca. 200-36 ka), are widely dispersed in central-southern italy (giaccio et al., 2009; 2013; 2017a; 2019; petrosino et al., 236 branca s. et al. 2014; monaco et al., 2021). the largest events, such as the ~456 ka pozzolane rosse, can be traced in the tephra record as far as lake ohrid (leicher et al., 2019; 2021). 3.2.6. volsci volcanic field (ca. 760-230? ka) this volcanic field (also known as monti ernici or middle latin valley volcanoes) groups several monogenetic centers (e.g., scoria cones, maar-diatremes and tuff rings) scattered through the middle latin valley and the volsci carbonate range, as far as the adjoining pontina plain (pasquarè et al., 1985; boari et al., 2009b; centamore et al., 2010; cardello et al., 2020; marra et al., 2021 and reference therein; fig. 14). the volsci eruptive pattern was characterized by small volume (in the order of 0.01-0.1 km3) eruptions from a network of monogenetic centers, totaling nearly 4 km3, i.e., two orders of magnitude lower than the major potassic volcanic districts of the roman province. three main phases of activity have been distinguished (marra et al., 2021), as follows: 1) the “early eruptive phase” (ca. 761-541 ka) mainly occurred along the carbonate volsci range (e.g., patrica eruptive center) and was essentially fed by k-rich, leucite-melilite-bearing (hks) magmas, showing evidence of high degree of carbonate assimilation, possibly due to multi-stage ascent through thick carbonate successions (hence the diffuse phreatomagmatic character); 2) subsequently, during the “main eruptive phase” (ca. 424-349 ka), hks rock types alternated with poorly differentiated, plagioclase-bearing (ks) rock types from eruptive sources close in time and space (e.g., in the ceccano and pofi areas). in particular, the eruptive activity along the major faults bounding the middle latin valley graben testifies for the fast ascent of nearly primary ks magmas (k-basaltic in composition; centamore et al., 2010); 3) during the “late eruptive phase (ca. 300-231? ka), ks magmas prevailed, although still accompanied by hks events. the low-intensity and low-volume (i.e., hawaiian-strombolian, phreatomagmatic, and subordinate effusive) eruptive events, fed by poorly differentiated potassic magmas, reflect the tectonically controlled, fast ascent of primitive magma batches from the mantle source (“bullet eruptions”; cardello et al., 2020). owing to the lack of glass chemical compositions from the volsci pyroclastic deposits, identifying potential distal correlatives is hardly feasible. nevertheless, the fig. 13 stratigraphic-chronological scheme and geological sketch of the colli albani (alban hills) volcanic district (marra et al., 2011; gaeta et al., 2016). 237 the italian quaternary volcanism volsci is currently the sole volcanic source for which an activity as old as 760 ka is documented in near-vent setting, which is geochronologically compatible with a series of sulmona tephra layers dated between ~805 and ~715 ka (giaccio et al., 2013b; 2015). 3.2.7. roccamonfina volcano (630-55? ka) roccamonfina volcano (fig. 15) is the result of the superposition of different morphostructures. the oldest edifice is a stratovolcano made up mostly of leucitebearing, highly silica-undersaturated (high-k series; hks; conticelli et al., 2009b), phonotephritic lava flows and strombolian deposits (roccamonfina synthem, de rita & giordano, 1996). an age of 630 ka was obtained for the pyroclastic deposits at the very base of the volcanic pile sampled from a deep borehole drilled at the center of the present caldera (ballini et al., 1989a). some k-ar ages as old as ~1.2 ma (gasparini & adams, 1967) and ~700 ka (radicati di brozolo et al., 1988) reported for the products of this early stage may be not reliable for modern analytical standards. as a result of ne-trending extensional faults cutting the edifice, a major lateral sector collapse interrupted the growth of the stratovolcano (de rita & giordano, 1996) at around ~440 ka (end of rio rava stage; chiesa et al., 1995; giannetti, 2001; rouchon et al., 2008). subsequent activity (related to the riardo synthem; de rita & giordano, 1996) shifted to dominantly explosive and a series of vei 3-5 subplinian to plinian eruptions shaped a polygenetic summit caldera, superimposed to the earlier sector collapse (cole et al., 1993; de rita & giordano, 1996; giannetti, 2001). ruchon et al. (2008) subdivided this caldera-forming stage into several substages. the oldest one, between 410 ka and 360 ka, culminated with the first caldera-forming event of the brown leucitic tuff (blt; luhr & giannetti, 1987; cole et al., 1993), which is the last eruption involving hks magmas at roccamonfina. the following activity was fed by slightly silica-saturated leucite-free magmas with a shoshonite affinity (sho; conticelli et al., 2009b). between ~331 ka and ~230 ka, the white trachytic tuffs (wtts; ballini et al., 1989b; cole et al., 1993; giordano, 1998a,b: giannetti & de casa, 2000) originated from multiple trachytic plinian eruptions. at least two of them (i.e., wtt cupa and wtt galluccio of giordano, 1998a, or lwtt and uwtt of giannetti & de casa, 2000) resulted into caldera collapses in the central area of the volcano. the pyroclastic deposits of the yellow trachytic tuff (rouchon et al., 2008) were also emplaced during this period. the youngest activity at roccamonfina (vezzara synthem; de rita & giordano, 1996; or 170-150 ka santa croce stage; rouchon et al., 2008), was controlled by ntrending tectonic lineaments and gave birth to the intracaldera latitic domes of lattani and m.te santa croce. eruptive activity ended at ~150 ka according to rouchon fig. 14 geological sketch map of southern latium, showing the location of the volsci volcanic field (square area) between the major colli albani and roccamonfina volcanoes (after marra et al., 2021, modified). 238 branca s. et al. et al. (2008), though a younger age of ~55 ka is reported in radicati di brozolo et al. (1988). in distal setting, tephra layers attributed to the roccamonfina activity have been recognized on regional and extra-regional scales. rio rava is documented in molise region, immediately east of roccamonfina volcano (russo ermolli et al., 2010), while blt has been recently identified in the fucino basin (central italy) and associated to the widespread “bag tephra” of danubian middle pleistocene loess succession (leicher et al., 2023). the lwtt is also well documented in molise alluviallacustrine successions (amato et al., 2014; galli et al., 2017) and, more distally, in the fucino basin (leicher et al., 2023). of note, distal records, spanning the 600-200 ka interval, indicate the occurrence of a number of tephra layers with roccamonfina-like geochemical compositions that currently lack specific proximal counterparts (e.g., giaccio et al., 2014; petrosino et al., 2014; leicher et al., 2021), providing evidence for a conspicuous, yet still not well-defined, middle pleistocene explosive activity at roccamonfina volcano. 3.2.8. final remarks: the state of volcanic activity ongoing research aims at refining the chronology of volcanic activity in central italy, in order to better constrain the eruption frequency and the duration of quiescence periods, which is crucial for long-term hazard assessment. in this regard, tephra correlations from distal archives provide additional, detailed information for a comprehensive reconstruction of tempo and dynamics of the peri-tyrrhenian quaternary volcanoes (e.g., giaccio et al., 2019; leicher et al., 2019; monaco et al., 2021; 2022a). based on the ages of the last documented eruptive events in the roman province, i.e., ca. 111 ka at vulsini, ca. 95 ka at vico, ca. 70 ka at sabatini and 36 ka at colli albani (the latest activity at volsci and roccamonfina is not yet well constrained), it appears that the waning (or, possibly, cessation) of eruptive activity shifted progressively from nw to se. strikingly, these volcanoes reveal a “relay behavior” (marra et al., 2020a), i.e.: the waning stage of activity at vulsini (ca. 150-110 ka) was concomitant to an activity climax at vico (third period, perini et al., 2004; also including the main caldera-forming event of tufo rosso a scorie nere vicano); then, waning activity at vico (ca. 95 ka) occurred during a peak of phreatomagmatic activity at sabatini; again, the last documented eruption at sabatini (ca. 70 ka) was accompanied by the onset of the albano maar cycle at colli albani. finally, the last eruptive phase at albano (40-36 ka) was broadly coincident with the climactic super-eruption of the 40 ka campanian ignimbrite at campi flegrei. the focus of volcanic activity seems therefore to have shifted through time from northern latium, through the roman area, toward the neapolitan area. however, considering that the time lapse since the last documented eruptions at sabatini (ca. 70 kyr) and colli albani (ca. 36 kyr), is in the same order of the dormancies occurred in the activity history of the two volcanoes (ca. 70 kyr and ca. 40 kyr, respectively), the possible occurrence in the near future of eruptive codas from the dormant “twin” volcanoes at the gates of rome cannot be ruled out (marra et al., 2020b). in addition, a recent work by giordano & caricchi (2022) points out that defining the state of activity of volcanoes based on recurrence times alone requires the assumption that the magma plumbing system is steadystate, while even at constant magma fluxes, the thermal fig. 15 sketch geological map of the roccamonfina volcano showing the main volcanic units grouped into the respective synthems (redrawn after conticelli et al., 2010). 239 the italian quaternary volcanism and geometric configurations and chemical reactivity of plumbing systems may change significantly over time. this means that as they thermally mature, plumbing systems may allow the growth and coalescence of progressively larger magma bodies, implying progressively a longer quiescence, which may lead to larger eruptions. in this sense, refining our knowledge of the longevity of a volcano is as important as knowing the age of its last eruption, and this is why recent efforts in extending back the distal tephrochronology of the peri-tyrrhenian quaternary volcanoes is so important (e.g., giaccio et al., 2019; leicher et al., 2019; monaco et al., 2021). at the same time giordano & caricchi (2022) pointed out that the heat flux of the roman volcanoes, especially at vulsini and sabatini is as high as, and locally even higher than, at the certainly active ischia and campi flegrei volcanoes and much higher than at vesuvius, suggesting that in order to define the state of activity of these volcanoes a much better imaging of their present magma plumbing system is required, although again none should be considered extinct. 4. peninsular-insular southern italy volcanoes and seamounts 4.1. the pontine archipelago (a.m.c., c.p.) the pontine archipelago consists of five major volcanic islands divided in western islands, ponza, palmarola and zannone and eastern islands, ventotene and s. stefano (fig. 16a). the western islands lie on a ne-sw elongated structural high dividing two major areas of sedimentation i.e., the palmarola and ventotene intraslope basins (fig. 16a) created by the plio-pleistocene extensional deformations, which also gave rise to a very steep nw-se trending continental slope and an intense magmatic activity developed from late pliocene to late pleistocene (conte & dolfi, 2002; cadoux et al., 2005). the eastern islands are the emerged portions of the caldera rim of a large strato-volcano rising ca. 700 m from the sea-floor emplaced at the center of the subsiding ventotene basin (fig. 16a; metrich et al., 1988; bellucci et al., 1999). in the western islands the pliocene volcanic cycle (4.5-2.9 ma; cadoux et al., 2005; fig. 17a) produced a large effusion of high-k, calc-alkaline (hkca) rhyolite lavas from extensional fissures in a submarine environment. this led to the emplacement of differently textured hyaloclastites and lava dykes which formed the typical cryptodome-dyke systems that constitute most part of ponza island (fig. 16b, c). indeed, three main coalescing domes of about 1 km radius, centered at cala m.te pagliaro and aligned along a ne trending regional fracture, have been identified at ponza on a morphological basis (de rita et al., 2001). the same likely occurred in the submerged sw sector of palmarola (conte et al., 2016; fig. 16b). at zannone, as a consequence of local eustatic movements, rhyolite magmas similar, and probably coeval to those of ponza (conte et al., 2016), were emplaced as cryptodomes in a subaqueous/subaerial environment and also intruded into a substrate made up of sedimentary and metamorphic units, which are locally exposed (de rita et al., 1986). this prevented the fine white hyaloclastite to form and led to the formation of a strongly brecciated lava in which flow structures are often recognized. similar brecciated lava facies are observed in the nw sector of ponza island, including the islet of gavi, suggesting a similar subaqueous/subaerial environment of emplacement. the second volcanic cycle started in early pleistocene age (1.64-1.52 ma; fig. 17a) during which palmarola was entirely built owing to the emplacement of a submarine hyaloclastite unit intruded by dykes ranging in compositions from nearto peralkaline trachytes and rhyolites belonging to the transitional rock-series (tr; conte et al., 2016). the pleistocene activity progressed with the local emission of comendite lava (1.2 ma; savelli, 1987) and the emplacement of pyroclastic trachytic products in the southern part of ponza (1.2-0.9 ma; savelli, 1987; bellucci et al., 1999; fig. 17a), where the resumption of volcanism coincides with the transition from a submarine to a subaerial environment. the pleistocene cycle ended at ca. 1.0 ma with the emplacement of trachytes of potassic series (k-alkaline, ka fig. 17b) in the southeastern part of ponza (i.e., the monte la guardia lava dome, punta della guardia lava dyke, fig. 16c). this episode represents the debut of the potassic alkaline magmatism that successively developed southeastward to the eastern pontine islands up to the romancampanian magmatic provinces. the eastern pontine islands, ventotene and s. stefano, display a similar chronological sequence of the outcropping units, which were erupted during the 0.9 and 0.1 ma time span (fig. 17a). it was initially characterized by effusive activity comprising a number of trachybasaltic lava flows (fig. 17b) followed by a huge explosive phase, which ended with the caldera formation. the composition of the volcaniclastic products ranges from latitic to trachytic and phonolitic (fig. 17b; bellucci et al., 1999). further insights on the magmatic spectrum existing in the pontine archipelago (fig. 17b) were provided by submarine rocks of relatively undifferentiated compositions (basalt to andesites), so far missing in the literature, collected in outcrops along the continental slope (conte et al., 2016), and in submarine volcanic edifices (i.e., the ventotene volcanic ridge; conte et al., 2020; fig. 16a, 17a, 17b). geochemical data from these new findings, and thermodynamic modeling allowed to rule out an anatectic origin for both subalkaline and peralkaline rhyolites recognized in the archipelago (paone, 2013) and to infer that the whole hkca-and tr-series felsic rocks, and the ka as well, derived by the respectively poorly evolved rocks by fractional crystallization processes (fig. 17b). moreover, the new geochemical data confirm the orogenic signature of the three suites and indicate highly heterogeneous mantle sources, due to crustal components variously recycled in the mantle via subduction. in addition, the age of these new findings (conte et al., 2020) led to infer that the pliocene and pleistocene volcanic cycles developed in the pontine archipelago are likely associated to the pliocene e-w directed rifting stage of the tyrrhenian back-arc basin, which produced a more intense activity during the time span ∼5.0-2.0 ma (the emplacement time of hkca and tr series). after that, this fault activity decreased and the extensional direction changed to nw-se causing the beginning of the ka activity (<∼2.0 ma). 240 branca s. et al. fig. 16 (a) location of the pontine archipelago in the central tyrrhenian sea. the inset indicates the morphological high of ventotene volcanic ridge (modified after conte et al., 2016 and 2020); (b) selected portion of the 1:50,000 geological map of foglio 413-borgo grappa (reported at reduced scale). in the simplified map legend are reported only the main volcanic units; (c) pliocene: hyaloclastite cryptodoma intruded by dykes at ponza; (d) pleistocene: trachytic lava dyke at punta della guardia, ponza, showing cooling structures (vertical and curved columnar jointing). 241 the italian quaternary volcanism 4.2. the neapolitan volcanoes: somma-vesuvius, campi flegrei and ischia island (r.s., r.c., s.d.v., m.a.d.v., r.i., s.m.) somma-vesuvius, campi flegrei and ischia island are among the most famous active volcanoes in the world and are part of the neapolitan landscape. the activity of the volcanoes punctuated the human history since bronze age, as testified by archaeological findings recognised in the plain and relieves surrounding the volcanic area. the world-famous eruption of 79 ce consigned the somma-vesuvius to the history, because of the burying of some important roman towns like pompeii and herculaneum. the campi flegrei volcanic field largely contributed to the birth of myths, and was one of the seven gates of roman hell. ischia island was always a favorite place for thermal baths since roman times. this brief chapter summarizes the main characteristics of these three world famous volcanoes, resuming their eruptive history, eruptive behavior, composition of their products and finally, the main hazards they pose to the surroundings and distal regions. 4.2.1. somma-vesuvius (39 ka-1944 ce) the somma-vesuvius volcanic complex consists of an older volcano dissected by a summit caldera, monte somma, and a recent cone, vesuvius, built within the caldera after the 79 ce “pompeii” eruption (cioni et al., 1999). the original roman name vesuvius (or vesbius) was first applied to the old volcano. starting from the fifth century, chroniclers make mention of mt. somma, as the highest (“summa”) peak of the mountain. the new cone grew discontinuously during periods of semi-persistent, low-intensity activity (from strombolian to violent strombolian, accompanied by important effusive activity). these periods possibly occurred in the first to third centuries, in the fifth to eighth centuries (after the 472 ce “pollena” eruption), in the tenth to twelfth centuries, and in 1631-1944 time span (cioni et al., 2008; santacroce et al., 2008). until relatively recent times, the formation of somma-vesuvius (sv) caldera was ascribed to the pompeii eruption. roman paintings from pompeii and herculaneum prompted stothers & rampino (1983) to conclude that, prior to 79 ce, the top of the volcano was asymmetrically shaped, indicating that a somma-type caldera was already present. the volcanological interpretation of the roman fresco from pompeii "mars and venus", now at naples national archaeological museum, made by nazzaro (1997) leaves few doubts about the presence of a pre-existing caldera (cioni et al., 1999). the sv caldera has a lobate, quasi-elliptical shape with a 5-km-long, east -west major axis (fig. 18a). the northern rim of the caldera is a well-defined steep wall, with an average elevation of approximately 1000 m. the drainage pattern of the highest portions of the volcano, unaffected by conspicuous deposition of recent products, is clearly radial, suggesting a symmetrical original cone. in this assumption, the shape and size of the ancient mt. somma can be constrained, placing the apex of the old volcano around 1900 m elevation and approximately 500 m north of the present vesuvius crater. although the general morphology of the volcano (fig. 18a) could be suggestive of the occurrence of lateral collapses of the seaward, western sector (milia et al., 1998; ventura et al., 1999; rolandi et al., 2004), field evidence discards such a possibility at least for the last 20,000 years (sulpizio et al., 2008). about 22 cal ky bp, the mainly effusive activity of mt. somma changed into largely explosive (fig. 18b). at least four high-magnitude plinian eruptions occurred, staggered with minor events covering a large range of magnitude and intensity. high-intensity, explosive eruptions sporadically occurred, the two largest being the subplinian events of 472 ce (also known as pollena eruption; rosi & santacroce, 1983; sulpizio et al., 2005) and 1631 ce (rosi et al., 1993; bertagnini et al., 2006). fig. 17 (a) chronology and serial affinity of pliocene-quaternary volcanism of the pontine archipelago and ventotene volcanic ridge. yellow, hkca; pale green, ka; dark green, tr. see the text for the abbreviation; (b) total alkali-silica (tas; le maitre et al., 2002) classification diagram reporting the whole range of compositions of volcanic rocks from pontine archipelago. the arrows indicate the liquid lines of descent simulating fractional crystallization trends leading to the felsic rocks constituting the islands from the relatively undifferentiated parental melts recovered in the islands and surroundings. specifically, a trachybasalt similar to that of ventotene led to the ka trachyte and trachyte-phonolite of ponza and ventotene, respectively; andesite rocks recovered by dredges in the deep water (yellow fill circles) led to the hkca pliocene rhyolites, and transitional basalts from both deep water (green small fill circles) and ventotene volcanic ridge led the tr pleistocene peralkaline rhyolites from palmarola (conte et al. 2016, 2020). * the age of zannone island is deduced by the morphological continuity with ponza and the compositional affinities of the products of the two islands. indeed, since now no absolute dating exists for the zannone due to the high alteration degree of the volcanic rocks (dolfi & conte, 2018). 242 branca s. et al. fig. 18 (a) geological map of somma-vesuvius volcano (santacroce et al., 2003; sbrana et al., 2020). for the legend the reader has to refer to the original publication; (b) chronogram of somma-vesuvius activity. arrows refer to explosive eruptions, length and colour reflect the estimated vei. blue boxes show recorded or inferred periods of persistent mild strombolian and effusive activity, punctuated by vei 2-3 explosive eruptions; (c) variation of somma-vesuvius rocks and glasses from the major explosive eruptions within total alkalis vs. silica (tas) diagram (santacroce et al., 2008). the variations of nb, sr and ba of major explosive eruptions of sv discriminate the three groups of rocks, and are peculiar for most of single eruptions. note the pompeii trend in the sr vs. ba plot, completely out of the “mildly silicaundersaturated” field (from santacroce et al., 2008); (d) pdc inundation frequency for the main eruptions of somma-vesuvius during the last 22 ka. the map shows areas that relate to high, medium, and low frequency of pdc inundation during the last 22 ka of activity (from gurioli et al., 2010); (e) probability hazard map for fallout load exceeding 300 kg/m2 for large explosive eruptions at somma-vesuvius (from sandri et al., 2016). 243 the italian quaternary volcanism the most recent period (1631-1944) was characterised by summit or lateral lava effusions and semi-persistent, mild explosive activity (small lava fountains, gases and vapour emission from the crater) interrupted by pauses lasting from months to a maximum of seven years (santacroce, 1987; arrighi et al., 2001; fig. 18b). lateral activity was minor and, starting from the 79 ce, the few eruptive fissures were confined to the western and southern sectors of the volcano (cortini & scandone, 1982; santacroce, 1987; principe et al., 2004; acocella et al., 2006). sv activity has been characterised in the last 20 ka by the eruption of potassic and ultra-potassic magmas spanning a wide compositional spectrum and showing an increase with time of both k2o content and silica undersaturation (fig. 18c). the shift from potassic magmas (represented by the trachytes and latites erupted in the period from the pomici di base to the greenish pumice) to k-rich compositions occurred before 8 ka. the products younger than 8 ka have been characterised by increasing alkalinity, and the products of the last 2 ka of activity (following the 79 ce pompeii pumice) show the most alkali-rich compositions and the lowest sio2 content of the whole set of the erupted products. slightly silica undersaturated (to saturated) magmas (blue field; fig. 18c) two large eruptions related to somma-vesuvius activity occurred in the period preceding the mercato eruption: the subplinian, 19,000 cal yr bp “greenish pumice” and the plinian, 22,000 cal yr bp “pomici di base”. the most relevant common geochemical signature of the rocks of all these eruptions, related to their k-trachytic highly evolved composition, concerns the higher silica and lower alkali contents (with respect to rocks with comparable degree of evolution of the other two groups), as well as their moderate sr and ba contents (fig. 18c). as a whole, the geochemical features of these rocks are coherent with evolutionary trends of kbasaltic liquids initially driven by crystallization of mafic phases and plagioclase and later involving k-feldspar fractionation. mildly silica undersaturated magmas (green field; fig. 18c) this group consists of the pyroclastic products of three plinian eruptions (79 ce “pompeii”, 3910 cal yr bp “avellino” and 8,900 cal yr bp “mercato”) and at least six other explosive eruptions occurred between the avellino and pompeii events (ap1 to ap6; andronico & cioni, 2002). differently from the mercato deposits, characterized by a strong compositional homogeneity all along the whole eruptive sequence, the products of the other eruptions of this group present important compositional variations, from the most evolved products at the base to the least evolved toward the top. the mercato and avellino eruptions (first-erupted white pumice) are characterized by the emission of the most evolved products of somma-vesuvius (cao<2.0%, nb>100 ppm; zr>700 ppm, th up to 100 ppm). strongly silica undersaturated magmas (pink field; fig. 18c) this group comprises all the products erupted after the 79 ce pompeii eruption. the most relevant common geochemical signatures of these rocks concern their lower silica and higher alkali contents with respect to rocks with comparable evolution from the other two groups, as well as their very high sr and ba contents (fig. 18c). these features are consistent with evolutionary trends (mostly fractionation within a periodically supplied magma chamber) of k-tephritic liquids dominated by crystallization of leucite and mafic minerals, and characterized by a minor role of plagioclase and the absence of k-feldspar fractionation. the products of the largest somma-vesuvius eruptions are widely dispersed in central mediterranean area, many of which being important stratigraphic markers for the regional archaeological and paleoclimatic investigations. codola is dispersed in tyrrhenian sea and adriatic sea and on land in san gregorio magno basin (petrosino et al., 2019), lake monticchio (wulf et al., 2004) and apulia. where acts as a marker for the palaeolithic successions (giaccio et al., 2008). mercato is an important marker for synchronizing the sapropel s1 in adriatic sea series with onland holocene successions of the central-southern italy and western area of the balkan peninsula (e.g., zanchetta et al., 2011). the avellino and pompeii tephra, with their quite opposite dispersal axis, from east to north and south-east, respectively also act as relevant stratigraphic markers for dating and synchronizing marine and and terrestrial successions of the southern-central and southern italy (zanchetta et al., 2011; crocitti et al., 2019; doronzo et al., 2022). 4.2.2. campi flegrei (>80 ka-1538 ce) campi flegrei (cf) is a ca. 14 km wide volcanic caldera located in southern italy, in a highly urbanized area including the western part of the city of naples. the campi flegrei volcanic field (fig. 19a), includes small volcanic apparatus and several monogenetic tuff rings, tuff cones and rarely cinder cones and lava domes. these volcanoes are exposed outside, on the borders, and within a large polygenetic caldera formed by the eruptions of the campanian ignimbrite (ci) and the neapolitan yellow tuff (nyt) (e.g., armienti et al., 1983; di girolamo et al., 1984; rosi & sbrana, 1987; orsi et al., 1992, 1995, 1996, 1999; cole & scarpati, 1993; rosi et al., 1996, 1999; di vito et al., 1999; de vivo et al., 2001; ort et al., 2003). the northern and western parts of the caldera are above sea level and characterized by the presence of many dispersed cones and craters, whereas the southern part is principally submarine and extends into the gulf of pozzuoli. the oldest rocks date back till ca. 80 ka and are represented by pryroclastic deposits cropping out outside and along the borders of the caldera (pappalardo et al., 1999; scarpati et al., 2012). precaldera volcanism mainly generated monogenetic tuff cones and subordinate lava domes widespread also within the city of naples (e.g., rosi & sbrana, 1987; scarpati et al., 2012). thick pyroclastic sequences generated from at least 80 ka also occur (orsi et al., 1996; pappalardo et al. 1999; (fig. 19a). the caldera forming large volume ci eruption (fisher et al., 1993; rosi et al., 1996) erupted ca. 300 km3 of trachytic dense rock equivalent magma (dre). the ci eruption was the largest magnitude eruption to occur in the mediterranean region during the late quaternary, and resulted in the formation of a 14-km wide caldera (rosi & sbrana, 1987). the eruption began with a plinian phase, during which a se-distributed pumice fallout was emplaced. this was followed by a succes 244 branca s. et al. fig. 19 (a) geological sketch map of the campi flegrei (from vitale and isaia 2014); (b) chronostratigraphy of campi flegrei activity (from vitale and isaia, 2014); (c) frequencies of pdc arrival computed using ec simulations (fsim) and pdc deposits (fobs) at campi flegrei. yellow star indicates downtown naples (from tierz et al., 2016); (d) conditional probability maps for a loading threshold of 300 kg/m2, for size small, medium, large and all sizes (from selva et al., 2018). 245 the italian quaternary volcanism sion of pyroclastic density currents (pdc) that deposited ash and pumice flows and densely-welded ignimbrites that covered the campanian plain and surrounding hills (barberi et al., 1978). proximal deposits (e.g., breccia museo, piperno) cropping out at the top of the eruption deposits along the caldera margins are interpreted as proximal facies related to the final caldera-forming phase (rosi & sbrana, 1987; rosi et al., 1996). on these deposits, several age data were produced (ca. 37 ka, deino et al., 2004; ca. 39 ka, de vivo et al., 2001; ca. 38 ka, fedele et al., 2008). a recent and high precision 14c and 39ar/40ar age determination of the ci yielded an age of 39.85±0.14 ka (giaccio et al., 2017b). after the ci caldera forming eruption volcanic activity occurred almost exclusively through the formation of pyroclastic deposits from several volcanic centers located within or along the border of the caldera. this period of activity culminated with the second large eruption at cf occurred at 15 ka (deino et al., 2004) named neapolitan yellow tuff (nyt; cole & scarpati, 1993; wohletz et al., 1995; fig. 19b), whose volume has been estimated larger than 20 km dre of latitic to trachytic magma (orsi et al., 1992, 1995; scarpati et al., 1993). the eruption was mainly phreatomagmatic producing pyroclastic density currents and subordinate thin fallout layers. the pdc deposits close to cf caldera were largely zeolitized and form the substrate on which lies the city of naples. ashes were mainly dispersed toward north-northeast from the vent area. the eruptions of the post-nyt period were confined within the structural boundaries of the caldera and comprised at least 70 known events, dominated by lowto medium-magnitude phreatomagmatic-magmatic eruptions with volumes of <0.1 km3 (di renzo et al., 2011; smith et al., 2011). the monte nuovo tuff cone formed as consequence of the most recent eruption in 1538 ce (e.g., d’oriano et al., 2005; di vito et al., 2016). after the nyt eruption, the caldera suffered significant ground deformation phenomena, especially in its central sector, where the uplift is still ongoing. the primary magmas produced have a mid-ocean ridge basalt (morb)-like asthenospheric mantle wedge composition, and these are modified by aqueous fluids, oceanic sediments, and continental crust (tonarini et al., 2004; d'antonio et al., 2007). the mafic melts at campi flegrei are k-basalts (e.g., webster et al., 2003). these mafic compositions are preserved as melt inclusions in antecrystic mg-rich olivines and clinopyroxenes in some eruption deposits (e.g., cannatelli et al., 2007). the composition of the erupted melts range from shoshonitic to phonolitic and trachytic, with the most differentiated compositions dominating (e.g., mangiacapra et al., 2008; smith et al., 2011; tomlinson et al., 2012; fig. 19c). the phenocrysts in these campi flegrei magmas are predominantly plagioclase + k-feldspar + clinopyroxene ± biotite. magnetite and apatite occur as accessory phases and eruption products occasionally contain olivine or rare feldspathoids. the sio2 and na2o contents of the magmas increase with differentiation, whereas cao, feo, mgo, and p2o5 contents decrease (e.g., civetta et al., 1991b). there is a noticeable inflection in k2o melt compositions, denoting k-feldspar-in, at ca. 60 wt% sio2 (fowler et al., 2007; smith et al., 2011; tomlinson et al., 2012). the sr, ba, and eu contents behave compatibly, and reflect the significant amount of felspar fractionation. other ree (excluding eu), y, nb, zr, rb, th, and ta are all incompatible (e.g., civetta et al., 1997; bohrson et al., 2006, arienzo et al., 2010; tomlinson et al., 2012). these major and trace element compositions follow an evolutionary trend that could be generated through fractional crystallization of a single parental melt (e.g., civetta et al., 1991a; d’antonio et al., 1999; fourmentraux et al., 2012) but isotopic variations indicate that the melts that erupt are derived from different batches of magma (pappalardo et al., 1999, 2002; d’antonio et al., 2007; di renzo et al., 2011; fig. 19c). samples from campi flegrei eruption deposits suggest that only evolved magmas were erupted in the early history (pappalardo et al., 1999) and it was only after the last caldera-forming nyt eruption (ca. 15 ka) that more compositionally diverse melts were erupted (e.g., d’antonio et al., 1999; smith et al., 2011). the isotope (nd, pb and sr) and occasionally the major and trace element glass compositions of the magmas indicate that the eruptions tap distinct batches of melt, and some have interacted at depth (e.g., di renzo et al., 2011). this has been well documented for the large caldera-forming events (e.g., forni et al., 2018) and for eruptions in the last 15 ka (e.g., tonarini et al., 2009; fourmentraux et al., 2012). the general trend between 60 and 10 ka is that nd and pb isotopic compositions of the erupted magmas became progressively less radiogenic (143nd/144nd 0.51252 to 0.51236 and 206pb/204pb 19.2 to 18.9) while the sr-isotope composition became more enriched (0.70700 to 0.70864) over time (pabst et al., 2008; di renzo et al., 2011). these changes in the isotopic compositions are consistent with an increase in crustal contamination. however, the campi flegrei liquid line of descent and extent of sr and pb isotopic heterogeneity is compatible only with very minor assimilation (d’antonio et al., 2007; fowler et al., 2007). the continuous and intense activity of the campi flegrei, makes this volcanic system the main source of the late pleistocene tephra in central mediterranean area. y-5, the tephra of the ci, the largest campi flegrei eruption, is to great extent the most widespread, and one of the most relevant stratigraphic markers for synchronizing stratigraphic, paleoclimatic and cultural events occured in western eurasia around 40 ka (e.g., giaccio et al., 2017b). though still poorly known in near vent sections, a number of other widely dispersed tephra preceding the ci eruption, including, among other the x-6, x-5 and c-22 marine layers, have been attributed to previously unknown 92-109 ka campi flegrei activity (monaco et al., 2022b). following the ci eruption, the two other tephrostratigraphic markers, which significantly exceed the regional dispersal, are those of the relatively poorly known masseria del monte eruption of ca. 29 ka (y-3, albert et al., 2019) and of the neapolitan yellow tuff, mainly dispersed toward north and found until central europe (e.g., lane et al., 2011; 2015). 4.2.3. ischia island (>150 ka-1302 ce) the island of ischia is part of the phlegraean volcanic district, related to extensional tectonic phases that accompanied the anticlockwise rotation of the italian peninsula (ippolito et al., 1973; d’argenio et al., 1973; 246 branca s. et al. finetti & morelli, 1974; bartole, 1984; piochi et al., 2005). ischia is the emerged part of an active volcanic field, which rises more than 1,000 m above the sea floor (fig. 20a; orsi et al., 1999; bruno et al., 2002), along the margin of an e-w trending scarp that borders to the south the phlegraean volcanic district. the island covers an area of 46.4 km2 and is morphologically dominated by the monte epomeo (787 m a.s.l.) in its central portion, and by the ne-sw monte vezzi monte cotto alignment in the se corner. volcanism at ischia dates back to more than 150 ka and continued, with centuries to millennia of quiescence, until the most recent eruption occurred in 1302 ce (vezzoli, 1988; sbrana & toccaceli, 2011; sbrana et al., 2018; fig. 20b). the oldest exposed rocks, aged between 150 and 75 ka, are lava flows and/or lava domes, and a sequence of pyroclastic deposits with intercalated paleosols, mainly exposed in the southern part of the island (scarrupata di barano formation in vezzoli, 1988; ancient ischia synthem in sbrana & toccaceli, 2011; phase 1 in sbrana et al., 2018; l.c. volcanics older than 75 ka of figs. 20b and c). almost in the same time span, a prevailing effusive activity determined the emplacement of a series of small trachytic and phonolitic lava domes, which are presently exposed at the periphery of the island (fig. 20a). a very intense period of explosive activity followed between 74 and 55 ka. during this period, many volcanic vents were active mainly in the southern sector of the island, likely producing the highest magnitude eruptions recorded at ischia. the deposits of at least 10 explosive eruptions, fed by phonolitic to trachytic magmas, generated pyroclastic density currents, fallout deposits, block and ash flows from collapsing lava domes, explosion breccias and hydromagmatic dilute and turbulent pyroclastic density currents (brown et al., 2008; rifugio di san nicola synthem in sbrana & toccaceli, 2011; phase 2 in sbrana et al., 2018). the activity of this period culminated with the caldera forming eruptions of the monte epomeo green tuff (megt) between 60 and 50 ka (brown et al., 2008; sbrana & toccaceli, 2011; sbrana et al., 2018; fig. 20b). this tuff consists mostly of trachytic ignimbrites that partially filled the caldera depression in a submarine environment, and were also emplaced on land outside its margins. the caldera depression was later the site of marine sedimentation, which formed a succession of clays, tuffites, sandstones and siltstones by the reworking of megt and sedimentary supply from the mainland (sbrana & toccaceli, 2011). after the megt eruptions, volcanism continued with a series of hydromagmatic and magmatic explosive eruptions up to 33 ka. most of the vents were located along the present sw and nw offshore of the island. volcanism in this period was fed by latitic and shoshonitic magmas (brown et al., 2014; phase 3 in sbrana et al., 2018), whose injection into the system triggered the asymmetric resurgence of the caldera floor, generating the monte epomeo block (orsi et al., 1991). after an about 5 ka long period of quiescence, volcanism resumed at ca. 28 ka. the beginning of this period of activity was marked by the eruption of shoshonitic magmas, isotopically distinct from those characterizing the previous eruptions, suggesting the arrival of a new batch of magma into the feeding system of ischia, followed by its differentiation and mixing with the resident magma (poli et al., 1987; civetta et al., 1991b; casalini et al., 2017). volcanism continued sporadically until 18 ka (or 13 ka, phase 4 in sbrana et al., 2018), with the emission of shoshonitic to alkali-trachytic magmas that fed effusive and both hydromagmatic and magmatic explosive eruptions, with the emplacement of lava flows and strombolian fallout deposits, and the construction of small tuff-cones and scoria-cones, exposed along the se and sw coasts of the island (fig. 20c; campotese subsynthem in sbrana & toccaceli, 2011). the radiometric dating of the outcropping volcanic products suggests that between 18 and 10 ka there was a period of almost complete quiescence (vezzoli, 1988), whereas other interpretations (sbrana & toccaceli, 2011; sbrana et al., 2018) seem to indicate the occurrence of some eruptions in this timespan. in any case, all the authors agree in considering the interval between 18 and 10 ka as a period of quiescence or very reduced volcanic activity (fig. 20b). a period of more sustained activity at ischia started at ca. 10 ka, and was fed by mainly trachytic and subordinately latitic magmas. these are characterized by a sr isotopic ratio lower than those of the previous periods, leading to hypothesize the arrival of a new, geochemically distinct magma into the system. volcanism was mainly concentrated around 5.5 ka and after 2.9 ka, with almost all the vents located in the eastern part of the island (fig. 20c). only a few vents are located outside this area, along regional fault systems or along the margins of the resurgent block: these vents generated a multi-vent lava field in the nw corner of the island, a pyroclastic sequence, exposed to the sw, and a lava dome in the n sector of the island. since 2.9 ka, about 34 effusive and explosive eruptions took place: the effusive eruptions emplaced lava domes and high-aspect ratio lava flows, while the explosive eruptions, both magmatic and phreatomagmatic, generated tuff cones, tuff rings and variably dispersed pyroclastic-fall and-current deposits, which had a very variable impact on both the island’s environment and human settlements (de vita et al., 2010 and references therein; sbrana & toccaceli, 2011; de vita et al., 2013; phases 5 and 6 in sbrana et al., 2018). as volcanism was not continuous since 10 ka, but characterized by the alternation of centuries of quiescence and periods of very intense activity, it has been hypothesized that repeated episodes of magma intrusions occurred intermittently (tibaldi & vezzoli, 2004; de vita et al., 2006; vezzoli et al., 2009; de vita et al., 2010), likely accompanied by resurgence. even if, since the last eruption, no evidence of renewal of uplift due to fault reactivation has been recorded in concurrence with more recent minor mass movements, the magmatic system of ischia has to be considered still active, as testified by intense volcanism in historical times and widespread fumaroles and thermal springs. the ischia volcanics belongs to the low-k series of the roman comagmatic province, ranging in composition from shoshonite to latite, trachyte and phonolite; the most abundant exposed rocks are alkali-trachytes (angiulli et al., 1985; poli et al., 1987, 1989; crisci et al., 1989; civetta et al., 1991; fig. 20d). the activity of ischia volcano is well documented in distal settings (e.g., wulf et al., 2004; 2008). the most widespread ischia tephra is the one related to the monte 247 the italian quaternary volcanism fig. 20 (a) geological and structural sketch map of ischia volcanic field. deposits of debris avalanches and volcanic vents are highlighted in marine areas (from sbrana et al., 2018). for the legend the reader has to refer to the original publication; (b) simplified chronostratigraphic sequence (not to scale) of ischia volcanic field (from sbrana et al., 2018); (c) total alkali vs. silica classification diagram showing the variability of composition for ischia products (from d’antonio et al., 2021; santacroce et al., 2008). k-b = potassic basalt; k-tb = potassic trachybasalt; sh = shoshonite; lt = latite; tr = trachyte (these rock names are relative to a potassic alkaline series); th/bas = tephrite/basanite; ph-th = phonotephrite; th-ph = tephriphonolite; ph = phonolite; (d) distribution of pdc in the last 10 ka (from selva et al., 2019); (e) distribution of pyroclastic fall-out deposits for all the eruptions in the last 10 ka (from selva et al., 2019). 248 branca s. et al. epomeo green tuff eruption of ca. 56 ka (tomlinson et al., 2014), matching the layer tm-19 of monticchio (wulf et al., 2004), s16 of san gregorio magno (petrosino et al., 2019) and tf-7 of fucino (giaccio et al., 2017a), and a still unknown, slightly older, ca. 60 ka, eruption that matches the widespread marine layer y-7 (keller et al., 1978) and the monticchio tephra tm-20 (d'antonio et al., 2021). several tephra layers that are compositionally attributable to ischia, preceding both megt and the unknown y-7-related eruption, found, e.g., in the tyrrhenian sea (paterne et al., 2008) and fucino (monaco et al., 2022a), extend the activity of this volcano at least to 200 ka. 4.2.4. procida island the volcanic island of procida formed due to several monogenetic explosive eruptions that led to the formation of five volcanic centres characterizing the emerged-submerged morphology of the island: vivara, pozzo vecchio, terra murata, fiumicello, and solchiaro (fig. 21; aucelli et al., 2022). these tuff rings, except the tuff cone of terra murata, are sw-ne oriented following a fault line crossing the centre of procida and the nearby island of ischia (e.g., pescatore & rolandi, 1981). de astis et al. (2004) tentatively constrained the beginning of the volcanic activity of procida island around 70 ka and several authors (alessio et al., 1976; lirer et al., 1991; fedele et al., 2012) identified the last fig. 21 geological map of procida island with the chronological classification of the main volcanic events and the location of the main coastal sites (from aucelli et al., 2022, modified after fedele et al., 2012). the position of the submerged marine terraces was obtained from putignano et al. (2014). 249 the italian quaternary volcanism https://www.sciencedirect.com/topics/earth-and-planetary-sciences/marine-terrace https://www.sciencedirect.com/science/article/pii/s0025322722000858?casa_token=p8notpiiy5kaaaaa:krw3akojpmovay324myoirgmgl3lbvrv2abiutapkbehvi3lhsnuurckcd4b7gvttx8yejrx#bb0325 volcanic episode of the area with the solchiaro eruption, occurred 22 ka (fedele et al., 2012). the different volcanic episodes, which led to several volcano-tectonic collapses, modified the original structure of the island together with the activity of the main fault systems (putignano & schiattarella, 2010). the deposits deriving from these activities, mainly made up of stratified to massive ash levels, are covered by a tephra succession, cropping out along the sw flank of vivara and pozzo vecchio and partially at terra murata, and interbedded with the volcanic formation of pignatiello (55-74 ka; fedele et al., 2012). procida rocks range in composition from basalt to shoshonite and trachyte. the presence of a compositional gap in the range sio2=54-59 wt % is evidence of magma bimodality, suggesting that the feeding magmatic system was formed by at least two different reservoirs located at different depths (de astis et al., 2004). 4.2.5. hazard assessment the neapolitan area represents one of the highest volcanic risk areas in the world due to the presence of three active volcanoes. in the last decades, many studies assessed tephra fall hazard from them combining field data and numerical simulations. initially, conditional ash load probability maps for one or few reference volcanic scenarios were provided (e.g., barberi et al., 1995; cioni et al., 2003; macedonio et al., 2008; costa et al., 2009; folch & sulpizio, 2010; sulpizio et al., 2012). the choice of selecting a single scenario was very useful to support civil protection emergency plans (e.g., emergency plan of vesuvius; dpc 2015) and it is computationally less expensive and more feasible for near-real-time applications (e.g., selva et al., 2014). however, this strategy was not appropriate to achieve an unbiased probabilistic volcanic hazard assessment (pvha; marzocchi et al., 2010; selva et al., 2010; sandri et al., 2016) since the uncertainty only accounted for wind conditions (e.g., macedonio et al., 2008; 2016). to overcome this limitation, the analysis of the intrascenario variability is certainly more complete, allowing a reduction of the epistemic uncertainty (e.g., selva et al., 2014; sandri et al., 2016; titos et al., 2022) in both long and short-term hazard assessments (e.g., selva et al., 2010; sandri et al., 2012; 2014; selva et al., 2014; thompson et al., 2015; constantinescu et al., 2016). in more recent pvhas at the neapolitan volcanoes, new sampling procedures have been set to fully explore the intra-size-class aleatory variability comparing the results with the classical approach based on reference volcanic scenarios, in the case of proximal/medial areas and large tephra loads from somma-vesuvius and campi flegrei (sandri et al., 2016) or by using ensemble modeling of submarine eruptive vents and tephra total grainsize distributions considering variable mass fraction and aggregates for ash (selva et al., 2018). moreover, montesinos et al. (2022) have developed a new bayesian event tree based on high performance computing applied to campi flegrei, aiming to robust and unbiased shortand long-term pvha on a large-scale (thousands km) and high-resolution (about 2 km) domain to be used by civil protection agencies, aviation companies and other stakeholders. a novel contribution in the quantification of volcanic hazard regards the estimation of the present state of the neapolitan volcanoes based on a simple physics-based statistical model that satisfactorily fits the eruptive history of each volcano (selva et al., 2022). the model is compatible with existing data (including isolated events and long repose periods) and accounts for two activity regimes (high-low) able to describe the temporal modulations in eruptive activity and to provide a homogeneous quantification of the probability of eruption, considering the state of the volcano and the possible transitions. more recently, massaro et al. (2023) proposed a new methodology for a probabilistic long-term tephra fallout hazard assessment in southern italy from the active neapolitan volcanoes (somma-vesuvius, campi flegrei and ischia). by means of thousands of numerical simulations they quantify the mean annual frequency with which the tephra load at the ground exceeds critical thresholds in 50 years. the output hazard maps account for changes in eruptive regimes of each volcano and are also comparable with those of other natural disasters in which more sources are integrated. for pyroclastic density currents, gurioli et al. (2010) provided the high, medium and low inundation frequency from the main eruptions of somma-vesuvius during the last 22 ka of activity (fig. 18d). more recently, quantitative pvhas were carried out by tierz et al. (2016) for somma-vesuvius and campi flegrei testing the energy cone model (fig. 19d) and by selva et al. (2019) for ischia island (fig. 20e-f). 4.3. the mt. vulture and monticchio lakes nested volcanoes (>730-130 ka) (s.c., p.p., j.p.s.-b.) the monte vulture and monticchio nested volcanoes with few small eccentric explosive monogenetic centres along the ofanto valley and at ripacandida make up the lucanian magmatic province (fig. 1). the volcanism of this magmatic province is located east of the apennine system, at the outermost edge of the fold and trust belt. the volcano lies on a structural high made up of meso-cenozoic units of the substratum overlain by pliocene continental sediments (schiattarella & beneduce, 2006) and is situated on a deep transfer fault (trinitapoli-paestum line in ciaranfi et al., 1983; vulture line in schiattarella et al., 2005). the volcanic activity at vulture-monticchio nested volcanoes (fig. 22a) developed entirely within the pleistocene starting at about 0.74 ma (villa & buettner, 2009). a reconstruction of the eruptive history of the volcano, after the pioneering work of hieke merlin (1967), was carried out by principe & la volpe (1989a), who recognized several markers useful to build a stratigraphic framework. the eruptive history has been systematically reinvestigated in the frame of the carg project by giannandrea et al. (2006), who adopted usbu systematics to map the primary volcanic products and the sedimentary deposits of the several fluvial/lacustrine successions that characterise the perivolcanic area (fig. 22b). they highlight the strong tectonic control on the whole of the vulture activity and identify erosional phases, epiclastic sediments and/or paleosoils which testify to the occurrence of variably long quiescence phases. the very first dated products pertain to the fara d'olivo sub-synthem (giannandrea et al., 2006) and are represented by two main ignimbrite units (ignimbrite a and b of crisci et al., 250 branca s. et al. 1983), for the lowermost of which an 40ar/39ar age of 739±12 ka has been determined (villa & buettner, 2009). these ignimbrites, to which a caldera collapse has been ascribed (principe & giannandrea, 2006), unconformably overlay the deposits of an older explosive activity (campanile subsynthem, giannandrea et al., 2006). a subaerial erosional phase, with the associated epiclastic sediments, marks the passage to the barile synthem, to which the toppo san paolo subsyntem, a lava dome, on the nw rim of the vulture, belongs, together with the rionero subsyntem, a complex sequence of pyroclastic fall and pyroclastic flow deposits. among these deposits, the fallout of masseria boccaglie (de fino et al., 1982) has the prominent role of a stratigraphic marker (marker m3 of la volpe & principe, 1989) younger than 720±25 ka (buettner et al., 2006). starting from the rionero, but mainly in the vulture-san michele subsynthems (principe & giannandrea, 2006) the main stratovolcano was built up between ca. 670 and 600 ka (brocchini et al., 1994; villa & buettner, 2009) by alternating mildly explosive and effusive activity, respectively emplacing block and ash flow with minor pyroclastic fall deposits, and thin lava flows. a phreatomagmatic eruptive phase (ventaruolo subsynthem) marks the beginning of an intense phase of destruction of the stratovolcano, occurred mainly during the melfi synthem deposition, in which parasitic vents along the north and north-eastern side of the volcano produced lava flows with the emission of the melfi haüynophire (557±7 ka, bonadonna et al., 1998; 573±4 ka, villa & buettner, 2009) and piano di croce lavas. the volcanic and tectonic activity of the vulture area has been sealed by a thick paleosoil (schiattarella et al., 2005), which la volpe & principe (1989) had identified as marker m18. the last deposits, grouped in the monticchio supersynthem by giannandrea et al. (2006), were erupted starting from ca. 500 ka (buettner et al., 2006 fig. 22 (a) detailed geological sketch map of the vulture volcanic products. legend: 1) monticchio lakes; 2) landslides, alluvial and lacustrine deposits; 3) laghi di monticchio synthem (upper pleistocene); 4) valle dei grigi fosso del corbo synthem (middle pleistocene); 5) melfi synthem (middle pleistocene); 6) barile synthem (middle pleistocene); 7) foggianello synthem (middle pleistocene); 8) fiumara di atella supersynthem (upper pliocene-lower pleistocene?); 9) cretaceous to miocene apennines units; 10) thrusts; 11) reverse faults; 12) normal faults; 13) strike-slip faults; 14) high-angle faults; 15) crateric rim; 16) secondary volcano eruptive centres. (b) unconformity bounded stratigraphic units forming the whole volcanic products of the vulture volcano. modified from schiattarella et al. (2005) and giano et al. (2022); (c) tas classificative diagram (le maitre et al., 2002) for the vulture volcanic rocks (modified from conticelli et al., 2010); (d) view of the lago grande di monticchio (available at fondoambiente.it/luoghi/monticchio?ldc ). 251 the italian quaternary volcanism https://fondoambiente.it/luoghi/monticchio?ldc and references therein) from a series of monogenetic centers, and mostly show evidence of phreatomagmatic activity. this supersynthem also includes the ash tuff deposits of the two maar-like centres of lago grande and lago piccolo di monticchio (fig. 22d). the recommended age of the lago piccolo subsynthem, which gives the youngest 40ar/39ar age determined so far for the vulture products, is 141±11 ka (villa & buettner, 2009). the bulk of the erupted products mostly belong to a basanite-tephrite-phonolite series (fig. 22c), with mafic products (basanites and tephrites) dominating in both lavas and pyroclastic rocks (e.g., de fino et al., 1986; beccaluva et al., 2002). more silica undersaturated rocks, though minor in volume, are typical of this volcanic complex (hieke merlin, 1964, 1967). melilitites, haüynites, haüyne-bearing leucitites are also found at the end of the monte vulture volcanic activity in the form of dykes, plugs and lava flows in the north-western flank of the volcano. on the other hand, trachyphonolites are found as dykes in the neighboring of the volcanic complex, and may be representatives of an earlier, and less silica undersaturated stage of activity (melluso et al., 1996; beccaluva et al., 2002). a small carbonatitic lava flow has been also found at toppo del lupo (e.g., stoppa & principe, 1997; d’orazio et al., 2008; stoppa et al., 2008). within the hydromagmatic units of the monticchio supersynthem, round lapilli tuff units with ejecta of intrusive carbonatites and mantle nodules are visible (e.g., jones et al., 2000; rosatelli et al., 2000; downes et al., 2002). k2o contents of the volcanic products decrease with time passing from monte vulture to monticchio volcanoes. sodic compositions are also found among lapilli tuffs of the monticchio lake activity (avanzinelli et al., 2008, 2009). two distal tephra attributed to vulture activity and tentatively correlated with ignimbrites a and b of crisci et al. (1983) despite the incomplete age overlap, were found embedded in the montalbano jonico marine sequence (petrosino et al., 2015). 4.4. aeolian islands (1.3 ma-present) (f.l., g.d.a., r.d.r., p.d., f.f., l.f., e.n., m.p., r.s., c.r., c.a. t., m.v.) 4.4.1. general background the aeolian islands arc is the most active volcanic structure in the mediterranean area, and is composed of seven volcanic islands (alicudi, filicudi, salina, lipari, vulcano, panarea, stromboli) and several seamounts rising ca. 2000-3000 m above the seafloor in the southern tyrrhenian sea (romagnoli, 2013; romagnoli et al., 2013) (fig. 23a). they are arranged in an articulated, tectonically-controlled arc-shaped structure, crossed in its central sector by the nnw-sse lithospheric tindariletojanni fault system, which has developed in a complex subduction-type scenario during the quaternary (ventura, 2013). the oldest products from the submarine sectors are dated to 1.3 ma (beccaluva et al., 1985), whereas the age of emergent islands ranges between 270-250 ka (leocat, 2011) and the present (fig. 23b). different stages of volcanic activity through time are established on the basis of the available radiometric ages and stratigraphic relationships with marine terraces and tephra layers of campanian and/or aeolian origin (lucchi et al., 2013a and references therein). the aeolian islands volcanoes are typically characterized by a large variety of volcanic landforms and rock types which mostly depends upon the wide compositional range observed in the erupted products from basalts to rhyolites with calcalkaline (ca) to potassic signature (de astis et al., 2013; forni et al., 2013; francalanci et al., 2013; lucchi et al., 2013a, b, c, d, e; nicotra et al., 2020) (fig. 23c), and the corresponding eruption types (from strombolian/ hawaiian to subplinian), under the direct control of regional fault systems and recurrent calderas and lateral collapses. the western aeolian volcanoes (salina, filicudi and alicudi) are considered extinct, and currently active to quiescent volcanoes (vulcano, stromboli, panarea, lipari) are basically restricted to the eastern and the outer portions of the sector of the aeolian islands arc. major explosive eruptions involving more evolved magmas occurred during the last 75 ka on stromboli (petrazza tuffs), salina (grey porri tuffs, lower and upper pollara tuffs) and lipari (monte guardia, vallone del gabellotto, monte pilato) producing widespread tephra layers recorded in the tyrrhenian, ionian and adriatic deep sea cores and other lake or terrestrial archives in southern italy (albert et al., 2017; meschiari et al., 2020 for references). hereafter we describe the most important geological features and chronology of the alicudi, filicudi, salina, lipari and panarea volcanic complexes (from west to east), whereas a particular attention will be given to vulcano and stromboli in dedicated paragraphs. the island of alicudi is the emerged portion of a composite volcano constructed between 106 and 28 ka by lava flows, domes and strombolian scoriae with a compositional range between ca basalts and high-k ca andesites (lucchi et al., 2013d). six eruptive epochs were characterized by a mainly central-type volcanism interrupted by periods of dormancy and three summit caldera-type collapses (lucchi et al., 2013d). the alicudi rocks are characterized by the most primitive geochemical and isotopic signature of the entire aeolian archipelago, with a progressive shift toward more acid products due to the evolution of the magma feeding system and polybaric crystal fractionation, and a lower control by extensional regional tectonics (peccerillo et al., 2013). the island of filicudi is the emerged portion of a volcanic complex, result of the superimposition of lava flows, lava domes and coulees and subordinate pyroclastic deposits ranging in composition from ca basalts to (minor) hk ca dacites (lucchi et al., 2013e). four eruptive epochs developed between 246 and 29 ka, separated by quiescence stages, erosional episodes and partial collapses of portions of the volcanic edifices (lucchi et al., 2013e). four partially overlapping stratovolcanoes and scoria cones (casa ficarisi, fossa felci, chiumento and monte guardia) were mostly controlled by the wnwese regional tectonic trend, with a progressive shifting of activity toward south-east. a variation of compositions toward the dacitic terms was recorded in the lava domes and coulees and explosive eruptions in the south-eastern sector of filicudi at ca. 64-50 ka (monte terrione, capo graziano, monte montagnola and case dello zucco grande; lucchi et al., 2013e). volcanic activity of filicudi has been regulated by the interaction of different evolutionary processes, such as fractional crystallization, crus 252 branca s. et al. fig. 23 (a) sketch bathymetry of the aeolian islands and seamounts, southern italy (modified from beccaluva et al., 1985). the trace of the tindari-letojanni fault system (tl) is shown. depth contour lines in metres below sea level. (b) schematic chronological framework of the aeolian islands volcanoes based on the available radiometric ages and correlation of marine terraces and tephra layers (see lucchi et al., 2013a for age references). (c) sio2 vs. k2o wt% (peccerillo & taylor, 1976) classification diagram of volcanic rocks from the aeolian islands volcanoes: ca=calcalkaline; hkca=high potassium calcalkaline; sho=shoshonitic; bas=basalt; basand=basaltic andesite; sho=shoshonite; and=andesite; lat=latite; dac=dacite; tra=trachyte; rhy=rhyolite. source of data: alicudi (lucchi et al., 2013d); filicudi (lucchi et al., 2013e); salina (lucchi et al., 2013b); lipari (forni et al., 2013); vulcano (de astis et al., 2013); panarea (lucchi et al., 2013c); stromboli (francalanci et al., 2013). (d) panoramic view from the north of the rocche rosse obsidian lava flow (rr) effused from the ne side of the monte pilato pumice cone (mp), the flanks of which are intensely dissected by quarry activity. (e) aerial view of the submarine gas bursts (arrows) occurred in 2002-2003 in the area of the minor islets; in the background the main island of panarea is visible. 253 the italian quaternary volcanism tal assimilation and mixing. the youngest activity in this area is recorded by the canna neck and lava flows (29 ka), representing the few remnants of an independent volcanic center offshore the nw coast of filicudi. the island of salina, in the center of the aeolian archipelago, is the emerged portion of a large volcanic complex developed through time under the influence of the three regional tectonic trends acting in the archipelago (nnw-sse, wnw-ese, ne-sw). six eruptive epochs between 244 and 15 ka produced lava flows, strombolian scoriae and hydromagmatic and subplinian pyroclastic deposits with a ca basaltic to high-k ca dacitic composition (lucchi et al., 2013b; nicotra et al., 2014; sulpizio et al., 2016), interrupted by major periods of quiescence, volcano-tectonic collapses and marine ingression phases during mis 7 and mis 5 stages (lucchi et al., 2013b). the typical twin-volcanoes shape of the island is the result of the superimposition of the monte dei porri stratocone with the compound volcano formed by the nested pizzo capo, monte rivi and monte fossa delle felci stratovolcanoes. magma compositions and their variation through time are the result of contamination of primary magmas with the calabro-peloritano lower crust and subsequent differentiation dominated by polybaric fractional crystallization becoming dominant during the activity of monte fossa delle felci and monte dei porri, whereas the older pizzo capo and monte rivi were fed by deep magma reservoirs located at the crustmantle boundary (nicotra et al., 2014). during the latest eruptive activities of the pollara crater (27-15 ka) magma mixing and mingling processes triggered high-energetic basaltic to rhyolitic explosive eruptions. the island of panarea (fig. 23d), together with the basiluzzo islet, the small rocks of le formiche and the minor islets of dattilo, panarelli, lisca bianca, bottaro, lisca nera are the remnants of ca to high-k ca andesite to dacite lava dome-fields, with minor pyroclastic products, representing the subaerial culminations of a large, mainly submerged, irregularly truncated cone-shaped volcanic complex. volcanism on panarea dates back to 155-149 ka, with different growth phases interrupted by erosional unconformities, whereas the latest explosive eruption occurred in the time range between 27-26 and 8.7 ka from an undefined eruptive vent in the area of minor islets (calanchi et al., 1999; lucchi et al., 2013c). although long considered an extinct volcano going through a weak fumarolic phase of activity, panarea was recently (2002-2003) characterized by signs of a possible eruptive renewal manifesting through spectacular submarine gas bursts occurred in 2002-2003 in the area of the minor islets (fig. 23d) and accompanied by seismic swarms and emission of high temperature fluids with magmatic geochemical signature (caliro et al., 2004; capaccioni et al., 2007). the island of lipari is the above-sea-level culmination of a broad, largely submerged volcanic complex belonging to the vulcano-lipari-salina volcanic belt. this volcanic complex is composed of a large variety of lava flows, domes and coulees and pyroclastic successions produced by a spectrum of hydromagmatic, strombolian to subplinian and effusive activities, under the control of major regional tectonic trends and recurrent volcanotectonic collapses. volcanism has developed between c. 267 ka and the medieval age, showing progressive westeast and south-north shifts of the eruptive vents through time, together with an overall chemical change of erupted products from early ca and high-k basaltic andesites to latest rhyolites with a notable gap in the dacites field and a steep increase in the k2o content through time (forni et al., 2013). the youngest volcanic eruptions produced the prominent monte pilato pumice cone (viii century ce) (fig. 23e) and the obsidian lava flows of rocche rosse and forgia vecchia (xiii century ce), sited in the north-eastern sector of the island, as well as highly dispersed white-coloured, fine-grained rhyolitic tephra layers (pistolesi et al., 2021). at present, lipari is in a quiescent stage with a few low-temperature fumaroles and hot springs. 4.4.2. vulcano volcanic complex (130 ka-present) the island of vulcano is the exposed summit of a largely submerged volcanic complex that is separated from the nearby lipari only by a shallow-water and narrow strait of sea. its development has occurred from about 130 ka to the well-known eruptive cycle of 1888-90 ce which gave origin to the definition of the “vulcanian” eruptive style (mercalli & silvestri, 1891). volcanism displayed a wide spectrum of eruptive-explosive activities from a number of volcanic edifices which become gradually younger moving north-westwards under control of tectonic structures associated to the nnw-sse oriented tindari-letojanni fault system. the development of the two il piano (ca.100 ka) and la fossa multi-stage caldera structures (78-8 ka) have the same nnw-sse elongation and display a progressive nnw-shifting through time (de astis et al., 2013) (fig. 24). erupted products have variable k-alkaline character and degrees of evolution, ranging from basalts to rhyolites and changing through time parallel to the evolution of the volcanic system. it is noteworthy that successive large-scale hydromagmatic eruptions from the la fossa caldera emplaced the widely distributed brown tuffs (70-8 ka) pyroclastic products (meschiari et al., 2020). the holocene activity mostly occurred from the la fossa and vulcanello eruptive centres (fig. 24), fed by magmas ranging from shoshonites to rhyolites and alternating each other (de astis et al., 2013; nicotra et al., 2018). the la fossa stratocone (lfo) (fig. 24a and b), in the middle of la fossa caldera, was built during the last 5.5 ka through recurrent hydromagmatic to vulcanian explosive eruptions, which gave rise to multiple dilute pyroclastic currents and fallout deposits, alternating with a few trachytic to rhyolitic lava flows. compositionally, the lfo products reach the maximum degrees of magma evolution and alkali contents on vulcano. the progressive growth of the cone occurred during different eruptive cycles interrupted by short intervals of quiescence. after the early activity (5.5-2.9 ka), when most of the present cone was built up to 250-300 m in elevation, a younger eruptive cycle during roman to early medieval times produced pyroclastic successions deposited by dilute to concentrated pyroclastic currents, two fallout layers and four lava flows from two different, intersecting craters (de astis et al., 2013; malaguti et al., 2022). the activity of the eccentric forgia crater (fig. 24c) in medieval times is still not chronologically well constrained. another explosive cycle of activity started from 1727 ce and culminat 254 branca s. et al. fig. 24 simplified geological map of vulcano merged on a shaded relief dem of the island, showing the areal distribution of the erupted products and vents during its eruptive history, as well as the collapse rims corresponding to the multi-stage formation of the il piano and la fossa calderas (modified from de astis et al., 2013). main landforms and caldera rims in the ne shallow-water submarine portion are also shown (from casalbore et al., 2018). age references from de astis et al. (2013) and references therein. magma compositions: basalt (bas), andesite (and), shoshonite (sho), latite (lat), trachite (tra), rhyolite (rhy), high-k (hk), shoshonitic (sho). (a) panoramic view of the central sector of the island of vulcano with the field evidence for the major volcano-tectonic collapse rims (vc1, vc2, vc4, vc6) leading to formation of the multi-stage il piano and la fossa calderas, and the la fossa stratocone (lfo) standing out in the middle of la fossa caldera. (b) view from the south of the summit area of lfo showing the crater (cr1) and vents (ve) of the ad 1888-1890 eruption, and its products characterized by bread-crust bombs and lava blocks; this crater is nested within older crater rims (cr2, cr3). the active fumarolic field (arrow) is visible along the northern rim of the ad 1888-1890 crater. (c) outcrop of the intensely hydrothermally altered rocks of the faraglione cone (fa) near to the spiaggia di levante beach, where intense gas emission in shallow-water areas (arrow) has occurred during the 2021-2022 unrest. in the background, the eccentric forgia crater (fo) is visible along the northern flank of lfp. (d) view from lipari of the vulcanello lava platform (la) and nested scoria cones (sc), with the lfo in the background. all photographs credit f. lucchi. 255 the italian quaternary volcanism ed with the effusion of the outstanding pietre cotte rhyolitic lava flow in 1739 ce, the last effusive event from lfo (de fiore, 1922). the gran cratere explosive eruptive cycle developed between 1739 ce and the latest paroxysmal activity of 1888-1890 ce, and was characterized by the distinctive emplacement of bread-crust bombs and lava blocks widely dispersed in the summit area of lfo (fig. 24b). since the last eruption, the lfo has shown only fumarolic activity, associated with shallow seismicity, fed by a shallow latitic magma body at a depth of 2.5-3.5 km (paonita et al., 2013; mandarano et al., 2016). gas emissions are concentrated in several high-temperature active fumaroles along the northern rim of lfo crater, and subordinate points of emission and hot springs in the submarine areas near the porto di levante harbour (granieri et al., 2006) (fig. 24c). unrest periods of increase in temperature above the usual range of 330-400 °c and in the magmatic component of the total gas flux (usually called ‘crises’) have occurred periodically (1920s, 1987-93, 1996-98, 2004-2009), with the last one started in september 2021 and still ongoing at the time of writing (aiuppa et al., 2022). vulcanello is located along the northern border of la fossa caldera and consists of three ne-sw-aligned, nested small strombolian scoria cones from which a lava plateau, made up by a composite lava flow field of pahoehoeto aa-lavas, formed (fig. 24d). the oldest reported submarine to shallow-water eruption occurred during roman times (ii century bc, stothers & rampino, 1983), whereas most of the subaerial activity took place up to early medieval times (de astis et al., 2013; malaguti et al., 2022), with latest eruptions around the xvi century and fumarolic activity persisting until 1878 ce (keller, 1980). in the early stages, vulcanello developed as an independent islet and was successively linked to the main island of vulcano through the progressive accumulation of ash erupted from la fossa forming the isthmus area between 1525 ce and 1550 ce (barbano et al., 2017). 4.4.3. stromboli composite volcano (85 ka-present) stromboli is a largely submerged composite volcano well-known for its persistent “strombolian” eruptive activity from historical times. controlled by a regional nesw structural system, the exposed portion of stromboli was entirely developed from ca. 85 ka to present times (e.g. gillot and keller, 1993; risica et al., 2019), whereas the strombolicchio neck is dated to ca. 204 ka. the successive epochs of activity, represented by paleostromboli i-iii (85-34 ka), vancori (26-13 ka), neostromboli (13-4 ka) and recent stromboli (<2.4 ka) (fig. 25), mainly erupted mafic products (ca. <56 wt% sio2) covering a large compositional affinity from calc-alkaline to shoshonitic and potassic-alkaline series (hornig-kjarsgaard et al., 1993; francalanci et al., 2013). these epochs were repeatedly interrupted by small, summit calderas and lateral collapses cutting the nw and se flanks of the volcano down to the submerged basis of the edifice (tibaldi, 2001; romagnoli et al., 2009) (fig. 25a, b). they largely conditioned the location of active vents and erupted products, with the current sciara del fuoco (sdf) scar developed during the last 13 ka. the activity has been mostly supplied from summit vents through alternating effusive and strombolian eruptions, whilst more intense subplinian explosions only characterized the paleostromboli i and vancori epochs, and subordinate (but notable) flank eruptions along the ne and sw buttressed flanks of the volcano took place during the neostromboli one. recurrent nw-dipping lateral collapses occurred during the holocene in alternation with sequences of eruptions, and caused the unloading of the magmatichydrothermal system, likely triggering atypical hydromagmatic eruptions and pyroclastic density currents (pdc) that affected the lower slopes of the volcano (lucchi et al., 2018). the recent stromboli epoch started during roman times and resulted in the construction of the summit pizzo scoria cone, whilst the san bartolo fissure erupted pahoehoe lava flows that largely invaded the ne coastal sector forming a fan-shaped delta, and represented the last effusive activity outside the sdf. the presentday activity of stromboli, starting from (at least) early medieval times, has occurred from a crateric terrace located at elevations of c. 750 m a.s.l. near the sdf headwall (rosi et al., 2013)(fig. 25c). this activity is typically characterized by continuous active degassing (puffing) and rhythmic, discrete, weak to moderate explosions lasting a few seconds (fig. 25d) that eject dark highly-porphyritic (hp) scoriaceous lapilli, bombs and ash, accumulating in the area around the craters and along the steep sdf scar. occasional more violent explosions, covering a large intensity range from major explosions to paroxysms (bevilacqua et al., 2020), produce convective plumes rising up to 7-8 km (fig. 25e) and eject mingled scoriaceous hp and “pumiceous”, light-coloured and lowporphyritic lapilli, bombs and spatter, together with lithic blocks derived from deeper craterization of the upper conduit and vent system. ballistic fallout can overcome the sdf walls impacting the flanks of the cone, and occasionally reaching the inhabited areas of stromboli and ginostra, whereas short-lived pdcs due to column collapse generally flow within the sdf (fig. 25f). during historical times, paroxysms occurred repeatedly in the xvi-xvii and the xx centuries, with the more energetic event in 1930 and 1944, whilst recent paroxysms occurred on 5 april 2003, 15 march 2007, and the close events of 3 july and 28 august 2019 (giordano & de astis, 2021; metrich et al., 2021; ripepe et al., 2021; viccaro et al., 2021). effusive eruptions from summit craters or lateral vents/fissures opened at various elevations within sdf, recurrently interrupt the ‘normal’ strombolian activity, lasting from ca. 1 day to a few months (e.g. in 2002-2003, 2007, 2014)( fig. 25g). for (at least) the past three centuries, lava flows have descended the steep slopes of sdf, and eventually reached the sea (e.g. in 2007, 2014, 2022), representing a negligible hazard for people and infrastructures. up to the middle age, lava flows have episodically surmounted the sdf lateral rims and expanded along the upper to lower flanks of the cone. recurrent gravitational instabilities and collapses at various scales along the oversteepened slopes of sdf are recorded during the last century (barberi et al., 1993), eventually resulting in tsunami waves along the stromboli and surrounding coasts, as observed associated to the december 2002 submarine and subaerial landslide developed along the sdf (tinti et al., 2005). 256 branca s. et al. fig. 25 simplified geologic map of stromboli (modified from francalanci et al., 2013) and morpho-structural sketch map (a) of its submerged flanks (modified from romagnoli et al., 2013). altitude points are in metres above sea level. the map is based on a dem-shaded relief image courtesy of dicea (dipartimento di ingegneria civile edile e ambientale), università di roma la sapienza (research project funded by the italian department of civil protection). age references from francalanci et al. (2013) and references therein. magma compositions: basalt (bas), basaltic-andesite (bas-and), andesite (and) shoshonite (sho), latite (lat), trachyte (tra), high-k (hk), shoshonitic (sho). (b) aerial view of the stromboli composite volcano and the sciara del fuoco collapse scar cutting its nw flank, with the active craters visible near its headwall (credit italian civil protection). (c) aerial view of the summit area of the stromboli composite volcano showing the ne-sw aligned active craters near the headwall of the sciara del fuoco collapse scar (credit ingv). (d) strombolian activity of the summit craters (credit m. pistolesi). (e) eruptive column formed during the 5 april 2003 paroxysm (credit ingv). (f) pyroclastic currents formed along the sciara del fuoco collapse during the 3rd july 2019 paroxysm (unknown author). (g) pahoehoe lava flows forming a lava delta along the sciara del fuoco collapse during the 2007 effusive activity (credit c. romagnoli). 257 the italian quaternary volcanism 4.4. mt. etna (500 ka to present) (s.b., m.g., e.n., m.v.) the eruptive history of mt. etna began about 500 ka (de beni et al., 2011) in the eastern sicily, an area of geodynamic complexities, where the apenninemaghrebian chain overlaps the undeformed margin of the african continental plate, the hyblean foreland, bounding westwards the oceanic ionian lithosphere (lentini, 1982; cristofolini et al., 1985; branca et al., 2004; 2008; 2011a,b; fig. 26). volcanic activity in the area developed after an early long period of scattered basaltic magmatism in the hyblean plateau that migrated northwards during middlelate pleistocene towards the region of the present mt. etna (neri et al., 2018). volcanism in this area began with fissure-type eruptions with tholeiitic affinity emplacing lava flows in submarine and subaerial environment (tanguy et al., 1978). remnants of the submarine activity are pillow-lavas and columnar outcrops on the eastern shore north of catania (about 500 ka; gillot et al., 1994; corsaro & cristofolini, 1997; 2000; de beni et al., 2011; fig. 26). subaerial tholeiites date back to 330 ka (de beni et al., 2011) and mostly crop out on the sw slopes of the volcano (fig. 26). the erupted lavas gradually changed in composition from subalkaline towards naalkaline, while the fissure activity mainly concentrated on the ionian coast along the timpe fault system starting from about 220 ka (tanguy et al., 1997; corsaro & cristofolini, 1997; branca et al., 2004; 2008; 2011a,b; fig. 26). during the last 130 ka the major eruptive axes migrated westwards, gradually aligning themselves on a central axis. this transition from fissure to central vent activity led to the construction of a series of centralconduit edifices producing strombolian to plinian eruptions in the area of the present-day valle del bove. as the central activity stabilized at ca. 57 ka (de beni et al., 2011), a huge stratovolcano, the ellittico, grew up. the intense eruptive activity both effusive and highly explosive of the ellittico created a roughly 3600 m-high cone, which constitutes the frame of the present edifice of mt. etna (fig. 26). the ellittico activity ended 15 ka ago after four plinian eruptions (coltelli et al., 2000; del carlo et al., 2017) that created a 4 km-wide caldera. this became the site of persistent volcanic activity that progressively led to the emplacement of a new stratovolcano, the mongibello, over the last 15 ka (fig. 26). the formation of the valle del bove, a horseshoe depression about 7 x 4.5 km wide that is located on the eastern flank of mt. etna, dates back to the activity of the mongibello stratovolcano, namely to 7478 7134 bce (malaguti et al., 2023). the activity of mongibello marks the beginning of the recent volcanic history of mt. etna, which also displayed a wide range of eruptive styles from purely effusive to violent explosive (branca & del carlo, 2004). historical records of eruptions date back to the greek colonization of sicily (734 bce), passing through other chronicles during the roman age and the xvii century (branca & abate, 2019) with reference, respectively, to the 122 bce plinian eruption (coltelli et al., 1998) and the impressive 1669 eruption (corsaro et al., 1996; nicotra & viccaro, 2012; kahl et al., 2017). the last few centuries were dominated by effusive and strombolian eruptions (branca & del carlo, 2005) with emission of hawaiitic products and subordinate mugearites (viccaro & cristofolini, 2008). over the last five decades, the eruption frequency and explosivity increased, while the composition of volcanic products shifted towards ktrachybasalts (tanguy et al., 1997; tonarini et al., 2001; viccaro et al., 2011; viccaro & zuccarello, 2017). mt. etna has been particularly active during the last 30 years, experiencing continuous morphological modifications (harris et al., 2011). most of the morphological changes were caused by the opening of eruptive fissures on the flanks of the volcano that produced lava flows, as in 1991-1993, 2004-05 and 2008-09, and large scoria cones, as during the 2001 and 2002-2003 eruptions (tonarini et al., 1995; clocchiatti et al., 2004; métrich et al., 2004; andronico et al., 2005; allard et al., 2006; ferlito et al., 2012; palano et al., 2017). since nineties, there was also a clear growth in the number of paroxysmal eruptions from the summit craters (fig. 26), which generated extensive eruptive columns, abundant tephra fallouts and ash-lapilli dispersion up to hundreds of km far from craters (andronico et al., 2021). main paroxysmal episodes occurred in short-term sequence of multiple events lasting weeks to years. remarkable sequences were in 1998-1999 (23 events in 6 months), 2000 (64 events in 6 months) and 2007 (7 events in 7 months). the last decade has also seen the development of some of the most energetic, yet long-lasting paroxysmal sequences of recent times, which have been fed by the most volatile-rich magmas ever found at mt. etna (zuccarello et al., 2021). these include a three-year-long sequence of 44 lava fountains during 2011-2013 (behncke et al., 2014; giuffrida & viccaro, 2017; giuffrida et al., 2018; zuccarello et al., 2022), and the very recent sequence of 62 events that took place between december 2020 and february 2022. these sequences alternate with periods of dominant effusive activity from both the summit and the volcano flanks (viccaro et al., 2019; borzì et al., 2020; giuffrida et al., 2021), with the only brief interlude of two short, but powerful paroxysmal series in december 2015 (4 events) and may 2016 (3 episodes) (corsaro et al., 2017; calvari et al., 2018; cannata et al., 2018; zuccarello et al., 2022). the recurrence of highly explosive events at the summit, which produce severe tephra fallout and episodic formation of pyroclastic density currents due to partial collapses of the south east crater cone (behncke, 2009a; ferlito et al., 2010; scollo et al., 2013; costa et al., 2023), and effusive flank eruptions from vents located at low altitude (del negro et al., 2013) have the potential to cause significant socio-economic damages because of the high probability to impact the densely populated areas around the volcano, as well as hundreds of thousands of tourists who visit mt. etna yearly. 4.5. the hyblean volcanism (m.g., m.v.) the hyblean volcanism began in upper triassic ca. 200 ma (cristofolini, 1966) and continued until lower pleistocene, with both submarine and subaerial episodes of mafic volcanism widely scattered across the area of southeastern sicily (carbone & lentini, 1981; schmincke et al., 1997). no volcanism is known to have occurred from the upper cretaceous to the middle-upper miocene. the mesozoic volcanism produced lavas of na-alkaline affinity that outcrop in the southernmost and eastern part 258 branca s. et al. fig. 26 synthemic geological map of mt. etna volcano with the main morphotectonic features (upper panel, modified after branca et al., 2011); a scheme of the stratigraphic relationships of the volcanic succession using the supersynthem, synthem and lithosomes classifications and the radioisotopic ages have been also reported down-left in the figure (modified after branca et al., 2011b) and aerial view of the mt. etna summit area taken on january 2021 with the 5 active craters, namely (lower panels): voragine (vor), north east crater (nec), bocca nuova 1 and bocca nuova 2 (bn1 and bn2), south east crater (sec). 259 the italian quaternary volcanism of the hyblean plateau. a hiatus of ca. 50 ma separates these earlier emissions from the later activity that resumed during miocene in the central-northern area of the plateau with eruptions of both tholeiitic and alkaline magmas (de rosa et al., 1991; tonarini et al., 1996; beccaluva et al., 1998; trua et al., 1998). the neogenequaternary volcanism includes two different eruptive cycles: a) the miocenic cycle, prevalently alkaline in composition (mostly basanites and alkali-olivine basalts), which is dominated by explosive eruptions testified by diatreme-related volcanoclastic deposits bearing a significant amount of mantle xenoliths (scribano, 1987a, b; scribano et al., 2009; suiting & schmincke, 2010; 2012); b) the plio-pleistocene cycle almost exclusively characterized by relatively basic magmas, ranging in composition from extremely silica-undersaturated alkaline magmas to silica-oversaturated tholeiites. the pliopleistocene cycle was the most widespread, taking place over an area of ca. 500 km2 at the northern margin of the hyblean plateau. large volumes of tholeiitic products were erupted in a shallow marine environment during the upper pliocene, followed by at least five episodes of alkali basaltic volcanism between the end of the upper pliocene and the lower pleistocene. the first of these episodes emplaced in the northernmost sector of the hyblean plateau a considerable volume of alkali basalts as pillow breccias, subaerial lavas and scoria deposits (behncke, 2009b), while the latest eruptions (ca. 1.4 ma; schmincke et al., 1997) emitted scarce volumes of basanitic and nephelinitic lavas. 4.6. the sicily channel (a.c., m.g., s.r., m.v.) 4.6.1. general background the sicily channel is set in the thinned continental crust of the pelagian block (fig. 27a), a rifted zone in the sicilian maghrebian chain foreland (catalano et al., 2014). the main morphotectonic features are three deep tectonic troughs, nw-se oriented, namely the pantelleria, linosa and malta grabens, which exert control on magma generation and ascent (fig. 27a). magmatism in the sicily channel is widespread and results in the occurrence of several volcanic submarine centres (civile et al., 2008; rotolo et al., 2006) and two subaerial volcanic complexes, the pantelleria (fig. 27b) and linosa islands. submarine volcanism began around 10 ma, with the latest event of the ‘ferdinandea’ ephemeral islet emersion in 1831 ce and the 1891 ce ‘foestner’ entirely submarine eruption (conte et al., 2014; coltelli et al., 2016; kelly et al., 2014). submarine volcanic rocks are mafic and dominantly mildly alkalic regarding the serial affinity (rotolo et al., 2006; white et al., 2020). ascent of mafic magmas is driven by tectonic structures, with the exception of pantelleria, where the route to the surface is facilitated in the northern part of the island (giuffrida et al., 2020) and inhibited in the central sector, with production of abundant felsic derivative products. 4.6.2. pantelleria (320-4 ka) the subaerial volcanic activity at pantelleria started around 320 ka and is characterized by emission of pantelleritic products emplaced as lava flows and pumice fallout deposits (civetta et al., 1984; mahood & hildreth, 1986; rotolo et al., 2013; jordan et al., 2018). nine ignimbrite eruptions covered the island (entirely to partly) in the age interval 181-46 ka and alternated with interignimbrite periods, during which tens of local eruptive centers were active (jordan et al., 2018, rotolo et al., 2021; fig. 27c). two ignimbrites out of nine, namely the capre and green tuff formations (age 140 and 46 ka, respectively) are associated with caldera collapses and related scarp remnants (la vecchia and cinque denti caldera, respectively; fig. 27b, speranza et al., 2012; rotolo et al., 2013). other five potential caldera collapses (now buried) have been hypothesized based on the occurrence of thick pyroclastic breccia horizons within or at the top of some ignimbritic deposits (jordan et al., 2018). over the period 181-46 ka, basaltic manifestations were rare and limited only to some lava flow units dating back to 118 ka and 83 ka (civetta et al., 1984) that were found in the northwestern part of the island (fig. 27c). the postgreen tuff volcanic activity was dominated by lowenergy strombolian eruptions and effusive events, mostly inside and along the rim of the cinque denti caldera. this activity produced pumice fall deposits, lava flows and domes of dominant pantelleritic compositions (civetta et al., 1988; rotolo et al., 2007). an updated stratigraphy of the post-green tuff evolution is given in rotolo et al. (2021) based on high resolution 40ar/39ar ages (scaillet et al., 2011) and paleomagnetic data (speranza et al., 2010), with two periods of activity after the green tuff eruption, instead of the five proposed by civetta et al. (1988). basaltic volcanism accounts for ca. 5 % of outcropping rocks and is centered in the nw sector of the island with short lava flows and scoria cones (giuffrida et al., 2020). mafic volcanism is dated (k/ar) in the age interval 31±13 ka and 27±10 ka, with possible younger ages close to 10 ka (unpublished data; civetta et al., 1984; fig. 27d). 4.6.3. linosa (1.06-0.5 ma) linosa is a small volcanic island (ca. 6 km2) whose subaerial portions represent only 4% of the entire volcanic edifice, which extends for ca. 20 km along the nw-se tectonic lineament characterizing the whole sicily channel (fig. 28; romagnoli et al., 2020). while no age data are available for its submarine activity, the subaerial eruptive history can be constrained between ca. 1.06 and 0.5 ma, during which volcanism was effusive to explosive, mostly hydromagmatic, and occurred over three major periods (rossi et al., 1996). erupted magmas show limited compositional variation, being only mafic (alkali basalts to hawaiites/mugearites), slightly more primitive than the pantelleria basalts. rare intrusive lithics in pyroclastic products have more evolved, syenitic compositions never erupted as magma. 4.7. seamounts of the tyrrhenian sea (6 ma-present) (r.d.r., s.d.v., p.d., f.l., e.n., r.s., c.a.t., m.v.) the tyrrhenian sea started its opening 15 ma during the apennine orogenesis as a result of back-arc extensional processes. in the southern sector, the roll-back of the ionian slab caused the se migration of the calabrian arc and accelerated the process of back-arc extension, leading to the progressive thinning and substitution of the continental crust with a new oceanic one. this process is responsible for the opening of the vavilov (6 260 branca s. et al. or 4.5 2.5 ma) and marsili (1.8 ma-pres.) oceanic basins and the birth and growth of a great number of seamounts (fig. 28a; trua et al., 2004), whose ages decrease from nw toward se. marsili is a huge (70x30 km) volcanic submarine complex, elongated along a n-s direction with its summit placed 3 km above the seafloor. although the oldest products date back to 1 ma, marsili is considered an active volcanic system due to: i) seismic activity typical of volcanic and hydrothermal areas (d’alessandro et al., 2012); ii) volcanic gases detected above the water column (lupton et al., 2011); iii) the products of the two eruptive episodes occurred 3000 and 5000 years ago, recognized at its top (iezzi et al., 2014). a temporal progression characterizes the marsili magmatic activity from iab-like basalts with calc-alkaline affinity to oib-like basalts (trua et al., 2007). the summit area is marked by volcanic cones perfectly preserved, with some evidence of lava flow fields and volcano-tectonic structures (ventura et al., 2013). magnaghi and vavilov are the other two important seamounts of the tyrrhenian sea, with an elongated shape over 20 km. magnaghi seamount is related to the ancient activity (3-2.7 ma; serri et al., 2001), whereas vavilov seamount formed during the quaternary (0.73-0.1 ma) and it could still be considered active (savelli & ligi, 2017). although they lie on a seafloor with morb-like geochemical signature (trua et al., 2007), the few rocks collected at magnaghi and vavilov seamounts show a mildly alkaline oib-like geochemical affinity (trua et al., 2007). palinuro seamount, considfig. 27 (a) schematic structural map of the sicily channel (pt: pantelleria through; mt: malta through; lt: linosa through, gb: graham bank) and (b) geological and structural sketch map of the island of pantelleria (modified after catalano et al., 2014); (c) volcanic succession in the area of kazen at pantelleria: pre-green tuff scoriaceous basaltic rocks are visible at the bottom of the succession, which is constituted in the upper portion by other pre-green tuff ignimbrites and finally by the green tuff ignimbrite; (d) pantelleria island (salto la vecchia): la vecchia caldera scarp. the caldera wall dips 50° nw (left) and separates flat-lying pre-caldera ignimbrites (to the right of the caldera wall), with concordant post-caldera ignimbrites and one fallout deposit. the sequence is topped by the green tuff ignimbrite (age 46 ka), the last of the nine pantelleria ignimbrites; (e) linosa island (punta calcarella): hydromagmatic and fallout deposits of three major volcanic phases. 261 the italian quaternary volcanism fig. 28 (a) morphometric map of the tyrrhenian sea; seamounts are labeled in white, whereas emerged volcanoes in yellow; (b) simplified geological map of ustica; (c) panoramic view of the western coast of the ustica island and of the monte costa del fallo stratocone (eruptive epoch 2); (d) panoramic view of the northern seacliff of the ustica island and of lavas and scoriae belonging to eruptive epoch 3. 262 branca s. et al. ered active or quiescent (milano et al., 2012), presents a 50 km e-w elongated shape, resulting from the superimposition of different volcanic edifices. the composition of emitted products is very similar to the emerged portion of the aeolian islands (trua et al., 2004). 4.8. ustica (730-ca.130 ka) (r.d.r., s.d.v., p.d., f.l., e.n., r.s., c.a.t., m.v.) the island of ustica is the exposed summit of a largely submerged ne-sw elongated volcanic complex rising about 2000 m above the tyrrhenian seafloor, including an extensive field of submerged volcanic cones (up to thirty) to the north of the island. it is located over a transitional zone between a northern domain characterized by thinned oceanic crust (ca. 8 km thick) and a variably thick (25-30 km) western-southern domain of continental crust (savelli, 1988; sulli, 2000). based on literature data and new unpublished studies, the eruptive history of the island of ustica, entirely developed during the quaternary (de vita et al., 1998; bonomo & ricci, 2010), is arranged into five epochs of activity (fig. 28b) that emplaced submarine to subaerial volcanic rocks with a na-alkaline signature. the first epoch (730-516 ka) includes submarine basaltic lavas emitted from fissural vents and basaltic to hawaiitic and mugearitic lavas relevant to the large mt. guardia dei turchi stratocone, which progressively emerged from the sea. basaltic to hawaiitic and mugearitic lava flows and pyroclastic products of the second epoch (490-441 ka) are related to the monte costa del fallo stratocone and its lateral eruptive vents, partly located offshore the west coast of the island. the third epoch (424-412 ka) is characterized by the emplacement of hawaiite/mugearite lava flows (fig. 28c and d) and trachytic pumice pyroclastic products from the monte costa del fallo stratocone, together with the products of a series of lateral vents including the trachytic, amphibole-bearing sub-intrusive body exposed at punta san paolo (alletti et al., 2005). the fourth eruptive epoch was fed by lateral dykes in the nw sector of monte costa del fallo stratocone that emplaced hawaiitic to mugearitic lava flows and minor strombolian deposits. finally, the fifth eruptive epoch includes the alkali-basaltic tuff cone and lava neck of capo falconiera, which was active at about 130 ka (de vita et al., 1998). the whole island of ustica has been eroded and reworked by different orders of marine terraces, whereas the volcanic products of capo falconiera are interlayered within marine terraces of the last interglacial (de vita et al., 1998). acknowledgments biagio giaccio and paola petrosino, together with all the co-authors, would like to thank an anonymous reviewer whose valuable suggestions helped to improve the first version of the ms. they are deeply indebted to the associate editor ilaria mazzini for inviting them to design and coordinate this review paper on the italian quaternary volcanism. references acocella, v., funiciello r. (2002) transverse structures and volcanic activity along the tyrrhenian margin of central italy, memorie della società geologica italiana 1, 739-747. acocella v., funiciello r. (2006) transverse systems along the extensional tyrrhenian margin of central italy and their influence on volcanism. tectonics, 25, tc2003. acocella v., porreca m., neri m., mattei m., funiciello r. (2006) fissure eruptions at mount vesuvius (italy): insights on the shallow propagation of dikes at volcanoes. geology, 34, 673-676. doi: 10.1130/g22552.1 acocella v., palladino d.m., cioni r., russo p., simei s. (2012) caldera structure, amount of collapse and erupted volumes: the case of bolsena caldera, italy. geological society of america bulletin, 124(910), 1562-1576. aiuppa a., bitetto m., calabrese s., delle donne d., lages j., la monica f.p., chiodini g., tamburello g., cotteril a., fulignati p., gioncada a., liu e.j., moretti r., pistolesi m. (2022) mafic magma feeds degassing unrest at vulcano island, italy. communications earth & environment, 3, 255. alagna k., peccerillo a., martin s., donati, c. (2010) tertiary to present evolution of orogenic magmatism in italy. in: beltrando m., peccerillo a., mattei m., conticelli s., doglioni c. (eds.) the geology of italy: tectonics and life along plate margins, journal of the virtual explorer, 36, paper 18. doi: 10.3809/jvirtex.2010.00233 albert p.g., tomlinson e.l., smith v.c., di traglia f., pistolesi m., morris a., donato p., de rosa r., sulpizio r., keller j., rosi m., menzies m. (2017) glass geochemistry of pyroclastic deposits from the aeolian islands in the last 50 ka: a proximal database for tephrochronology. journal of volcanology and geothermal research, 336, 81-107. albert p.g., giaccio b., isaia r., costa a., niespolo e.m., nomade s., pereira a., renne p.r., hinchliffe a., mark d.f., brown r.j., smith v.c. (2019) evidence for a large-magnitude eruption from campi flegrei caldera (italy) at 29 ka. geology, 47 (7), 595e599. doi: 10.1130/g45805.1 albini a., cristofolini r., di girolamo p., stanzione d. (1980) rare-earth and other trace-element distributions in the calc-alkaline volcanic rocks from deep boreholes in the phlegrean fields, campania (south italy). chemical geology, 28, 123-133. alessio m, bella f, improta s, belluomini g, calderoni g, cortesi c, turi b (1976) university of rome carbon-14 dates xiv. radiocarbon, 18, 321-349. allard p., behncke b., d’amico s., neri m., gambino s. (2006) mt. etna 1993-2005: anatomy of an evolving eruptive cycle. earth science reviews. 78, 85114. alletti m., pompilio m., rotolo s.g. (2005) mafic and ultramafic enclaves in ustica island lavas: inferences on composition of lower crust and deep magmatic processes. lithos, 84 (3-4), 151-167. amato v., aucelli p.p.c., cesarano m., jicha b., lebreton v., orain r., pappone g., petrosino p., russo ermolli e. (2014) quaternary evolution of the largest intermontane basin of the molise apennine (central-southern italy). rendiconti lincei. scienze fisiche e naturali, 25(2), 197-216. 263 the italian quaternary volcanism https://doi.org/10.1130/g45805.1 doi: 10.1007/s12210-014-0324-y andronico d., cioni r. (2002) contrasting styles of mount vesuvius activity in the period between the avellino and pompeii plinian eruptions, and some implications for assessment of future hazards. bulletin of volcanology, 64, 372-391. doi: 10.1007/s00445-002-0215-4 andronico d., branca s., calvari s., burton m., caltabiano t., corsaro r.a., del carlo p., garfì g., lodato l., miraglia l., murè f., neri m., pecora e., pompilio m., salerno g., spampinato l. (2005) a multi-disciplinary study of the 2002-03 etna eruption: insights into a complex plumbing system. bulletin of volcanology, 67, 314-330. andronico d., cannata a., di grazia g., ferrari f. (2021) the 1986-2021 paroxysmal episodes at the summit craters of mt. etna: insights into volcano dynamics and hazard. earth science reviews, 220, 103686. angiulli g., de francesco a.m., lomonaco l. (1985) nuovi dati geochimica sull’isola di ischia. mineralogica et petrografica acta, 29, 41-60. arienzo i., moretti r., civetta l., orsi g., papale p. (2010) the feeding system of agnano-monte spina eruption (campi flegrei caldera, italy): dragging the past into present activity and future scenarios. chemical geology, 270, 135-147. doi: 10.1016/j.chemgeo.2009.11.012 armienti p., barberi f., bizouard h., clocchiatti r., innocenti f., metrich n., rosi m., sbrana a. (1983) the phlegrean fields: magma evolution within a shallow chamber. journal of volcanology and geothermal research 17, 289-301. arrighi s., principe c., rosi m. (2001) violent strombolian and subplinian eruptions at vesuvius during post -1631 activity. bulletin of volcanology, 63, 126-150. doi: 10.1007ls004450100130 avanzinelli r., elliott t., tommasini s., conticelli s. (2008) constraints on the genesis of the potassium-rich italian volcanics from u/th disequilibrium. journal of petrology, 49, 195-223. avanzinelli r., lustrino m, mattei m., melluso l., conticelli s. (2009) potassic and ultrapotassic magmatism in the circum-tyrrhenian region: the role of carbonated pelitic vs. pelitic sediment recycling at destructive plate margin. lithos, 113, 213227. avanzinelli r., cioni r., conticelli s., giordano g., isaia r., mattei m., melluso l., sulpizio r. (2017) the vesuvius and the other volcanoes of central italy. geological field trips and maps, 9: no.1. 1, pp. 158. doi: 10.3301/gft.2017.01 avanzinelli r., benvenuti m.g., brogi a., cifelli f., cioni r., conticelli s., laurenzi m.a., liotta d., marroni m., pandolfi l., papini m., paternostro s., rook l., sepulveda birke j.p., tavarnelli e., valeriani l., vaselli o. (2022) itinerario 9 baccinello. monte amiata. val d’orcia e monte cetona. in: guide geologiche regionali toscana (conti p., conticelli s., cornamusini g., marroni m. (edts), società geologica italiana, roma, 15, 243-267. isbn: 9-788894-484434 aucelli p.p.c., mattei g., caporizzo c., di luccio d., tursi m.f., pappone g. (2022) coastal vs volcanic processes: procida island as a case of complex morpho-evolutive response. marine geology, 106814. doi: 10.1016/j.margeo.2022.106814 ballini a., barberi f., laurenzi m.a., mezzetti f., villa i.m. (1989a) nuovi dati sulla stratigrafia del vulcano di roccamonfina. bollettino gnv, 5, 533-555. ballini a., frullani a., mezzetti f. (1989b) la formazione piroclastica del tufo trachitico bianco del vulcano di roccamonfina. bollettino gnv, 5, 557-574. barbano s., castelli v., pirrotta c. (2017) materiali per un catalogo di eruzioni di vulcano e di terremoti delle isole eolie e della sicilia nordorientale (secc. xv-xix). quaderni di geofisica, 142. barberi f., ferrara g., innocenti f., marinelli g., mazzuoli r. (1971) a magmatic province of anatectic origin: the tuscan-latian province (italy). abstract, xv ucgi congress, moscow. barberi f., innocenti f., lirer l., munno r., pescatore t.s., santacroce r. (1978) the ci: a major prehistoric eruption in the neapolitan area (italy). bulletin of volcanology, 41, 1-22. barbieri m., di girolamo p., locardi e., lombardi g., stanzione d. (1979) petrology of the calc-alkaline volcanics of the parete 2 well (campania, italy). periodico di mineralogia, 48, 53-74. barberi f., innocenti f., landi p., rossi u., saitta m., santacroce r., villa i.m. (1984) the evolution of latera caldera (central italy) in the light of subsurface data. bulletin of volcanology, 47, 125-141. barberi f., rosi m., sodi a. (1993) volcanic hazard assessment at stromboli based on review of historical data. acta vulcanologica, 3, 173-187. barberi f., buonasorte g., cioni r., fiordelisi a., foresi l., iaccarino s., laurenzi m.a., sbrana a., vernia l., villa i.m. (1994) plio-pleistocene geological evolution of the geothermal area of tuscany and latium. memorie descrittive della carta geologica d’italia, 49, 77-134. barberi f., coltelli m., frullani a., rosi m., almeida e. (1995) chronology and dispersal characteristics of recently (last 5000 years) erupted tephra of cotopaxi (ecuador): implications for long-term eruptive forecasting. journal of volcanology and geothermal research, 69, 217-239. bartole r. (1984) tectonic structure of the latiancampanian shelf (tyrrhenian sea). bollettino di oceanografia teorica e applicata, ii, 3, 197-230. bear a.n., cas r.a.f., giordano g. (2009a) the implications of spatter, pumice and lithic clast rich proximal co-ignimbrite lag breccias on the dynamics of caldera forming eruptions: the 151 ka sutri eruption, vico volcano, central italy. journal of volcanology and geothermal research, 181, 225-255. bear a.n., cas r.a.f., giordano g. (2009b) variations in eruptive style and depositional processes associated with explosive, phonolitic composition, caldera -forming eruptions: the 151 ka sutri eruption, vico caldera, central italy. journal of volcanology and geothermal research, 184, 1-24. beccaluva l., gabbianelli g., lucchini f., rossi p.l., savelli c. (1985) petrology and k/ar ages of volcanics dredged from the aeolian seamounts: impli 264 branca s. et al. cations for geodynamic evolution of the southern tyrrhenian basin. earth planetary science letters, 74, 187-208. beccaluva l., siena f., coltorti m., di grande a., lo giudice a., macciotta g., tassinari r., vaccaro c. (1998) nephelinitic to tholeiitic magma generation in a transactional tectonic setting: an integrated model for the iblean volcanism, sicily. journal of petrology, 39, 1547-1576. beccaluva l., coltorti m., di girolamo p., melluso l., milani l., morra v., siena f. (2002) petrogenesis and evolution of mt. vulture alkaline volcanism (southern italy). mineralogy and petrology, 74, 277 -297. behncke b. (2009a) hazards from pyroclastic density currents at mt. etna (italy). journal of volcanology and geothermal research, 180, 148-160. behncke b. (2009b) late pliocene volcanic island growth and flood basalt-like lava emplacement in the hyblean mountains (se sicily). journal of geophysical research, 109, b09201. behncke b., branca s., corsaro r.a., de beni e., miraglia l., proietti c. (2014) the 2011-2012 summit activity of mount etna: birth, growth and products of the new se crater. journal of volcanology and geothermal research, 270, 10-21. bellucci f., lirer l., munno r. (1999) geology of ponza, ventotene and santo stefano islands (with a 1:15,000 scale geological map). acta vulcanologica, 11, 197-222. beltrando m., rubatto d., manatschal g. (2010) from passive margins to orogens: the link between ocean-continent transition zones and (ultra)highpressure metamorphism. geology, 38(6), 559-562. bertagnini a., sbrana a. (1986) il vulcano di vico: stratigrafia del complesso vulcanico e sequenze eruttive delle formazioni piroclastiche. memorie della società geologica italiana, 35, 699-713. bertagnini a., de rita d., landi p. (1995) mafic inclusions in the silica-rich rocks of the tolfa-ceritimanziana volcanic district (tuscan province, central italy): chemistry and mineralogy. mineralogy and petrology, 54, 261-276. bertagnini a., cioni r., guidoboni e., rosi m., neri a., boschi e. (2006) eruption early warning at vesuvius: the a.d. 1631 lesson. geophysical research letters. doi: 10.1029/2006gl027297 bevilacqua a., bertagnini a., pompilio m., landi p., del carlo p., di roberto a., aspinall w., neri a. (2020) major explosions and paroxysms at stromboli (italy): a new historical catalog and temporal models of occurrence with uncertainty quantification. scientific reports, 10, 17357. doi: 10.1038/s41598-020-74301-8 bevilacqua a., macedonio g., neri a., orsi g., petrosino p. (2022) volcanic hazard assessment at the campi flegrei caldera, italy. active volcano world. doi: 10.1007/978-3-642-37060-1_12 bigazzi g., bonadonna f.p., iaccarino s. (1979) geochronological hypothesis on plio-pleistocene boundary in latium region. bollettino società geologica italiana, 92, 391-422. boari e., avanzinelli r., melluso l., giordano g., mattei m., de benedetti a., morra v., conticelli s. (2009a) isotope geochemistry (sr-nd-pb) and petrogenesis of leucitebearing volcanic rocks from "colli albani" volcano, roman magmatic province, central italy: inferences on volcano evolution and magma genesis. bulletin of volcanology, 71, 977-1005. boari e., tommasini s., laurenzi m.a., conticelli s. (2009b) transition from ultrapotassic kamafugitic to sub-alkaline magmas: sr, nd, and pb isotope, trace element and 40ar-39ar age data from the middle latin valley volcanic field, roman magmatic province, central italy. journal of petrology, 7, 1327-1357. bohrson w.a., spera f.j., fowler s.j., belkin h.e., de vivo b., rolandi g. (2006) petrogenesis of the campanian ignimbrite: implications for crystal-melt separation and open-system processes from major and trace elements and th isotopic data. in volcanism in the campania plain: vesuvius, campi flegrei and ignimbrites, 9, 249-288. bonini m., sani f. (2002) extension and compression in the northern apennines (italy) hinterland: evidence from the late miocene‐pliocene siena‐radicofani basin and relations with basement structures. tectonics, 21, 1-19. bonomo r., ricci v. (2010) application of unconformitybounded stratigraphic (ubs) units to the geological survey of the volcanic island ustica (italy). stratigraphy and geology of volcanic areas, 51. borghetti g., sbrana a., sollevanti f. (1981) vulcano tettonica dell’area dei monti cimini e rapporti cronologici tra vulcanismo cimino e vicano. rendiconti della società geologica italiana, 4, 253-254. borsi s., ferrara g., tongiorgi e. (1967) determinazione con il metodo k/ar delle età delle rocce magmatiche della toscana. bollettino della società geologica italiana, 86, 403-410. borzì a.m., giuffrida m., zuccarello f., palano m., viccaro m. (2020) the christmas 2018 eruption at mt. etna: enlightening how the volcano factory works through a multi-parametric inspection. geochemistry geophysics geosystems, 21, 10, e2020 gc009226. branca s., abate t. (2019) current knowledge of etna’s flank eruptions (italy) occurring over the past 2500 years. from the iconographies of the xvii century to modern geological cartography. journal of volcanology and geothermal research, 385, 159-178. branca s., del carlo p. (2004) eruptions of mt. etna during the past 3,200 years: a revised compilation integrating the historical and stratigraphic records. geophysical monograph series 143, 1-27. branca s., del carlo p. (2005) types of eruptions of etna volcano ad 1670-2003: implications for shortterm eruptive behaviour. bulletin of volcanology, 67, 732-742. branca s., coltelli m., groppelli g. (2004) geological evolution of etna volcano. in: bonaccorso a., calvari s., coltelli m., del negro c., falsaperla s. (eds). mt. etna volcano laboratory. agu (geophysical monograph series), 143, 49-63. branca s., coltelli m., de beni e., wijbrans j. (2008) geological evolution of mount etna volcano (italy) from earliest products until the first central volcan 265 the italian quaternary volcanism https://doi.org/10.1038/s41598-020-74301-8 https://doi.org/10.1007/978-3-642-37060-1_12 ism (between 500 and 100 ka ago) inferred from geochronological and stratigraphic data. international journal of earth sciences, 97, 135-152. branca s., coltelli m., groppelli g. (2011a) geological evolution of a complex basaltic volcano: mount etna, italy. italian journal of geosciences, 130 (3), 306-317. branca s., coltelli m., groppelli g., lentini f. (2011b) geological map of etna volcano, 1:50,000 scale. italian journal of geosciences, 130 (3), 265-291. brocchini d. (1999) cronologia ed evoluzione del vulcanismo nell’area del somma-vesuvio. ph.d. thesis, pisa, 1-168. brocchini d., la volpe l., laurenzi m.a., principe c. (1994) storia evolutiva del mt. vulture. plinius 12, 22-25. brocchini d., di battistini g., laurenzi m.a., vernia l., bargossi g.m. (2000) new 40ar/39ar datings on the southeastern sector of the vulsinian volcanic district (central italy): bollettino della società geologica italiana, 119, 113-120. brown r. j., orsi g., de vita s. (2008) new insights into late pleistocene explosive volcanic activity and caldera formation on ischia (southern italy). bulletin of volcanology, 70, 583-603. brown r.j., civetta l., arienzo i., d'antonio m., moretti r., orsi g., tomlinson e.l., albert p.g., menzies m.a. (2014) geochemical and isotopic insights into the assembly, evolution and disruption of a magmatic plumbing system before and after a cataclysmic caldera collapse at ischia volcano (italy). contribution to mineralogy and petrology, 168, 1035. bruno p.p.g., de alteriis g., florio g. (2002) the western undersea section of the ischia volcanic complex (italy. tyrrhenian sea) inferred by marine geophysical data. geophysical research letters, 29(9), 1343. buettner a., principe c., villa im, brocchini d. (2006) geocronologia 39ar-40ar del monte vulture. la geologia del monte vulture (a cura di claudia principe) in c. principe ed. la geologia del monte vulture, 73 -86. calanchi n., tranne c.a., lucchini f., rossi p.l., villa i.m. (1999) explanatory notes to the geological map (1:10 000) of panarea and basiluzzo islands, aeolian arc, italy. acta vulcanologica, 11, 223-243. caliro s., caracausi a., chiodini g., ditta m., italiano f., longo m., minopoli c., nuccio p.m., paonita a., rizzo a. (2004) evidence of a new magmatic input to the quiescent volcanic edifice of panarea, aeolian islands, italy. geophysical research letters, 31, l07619. cadoux a., pinti d. l., aznar c., chiesa s., gillot p. (2005) new chronological and geochemical constraints on the genesis and geological evolution of ponza and palmarola volcanic islands (tyrrhenian sea, italy). lithos, 81, 121-151. calanchi n., tranne c.a., lucchini f., rossi p.l., villa i.m. (1999) explanatory notes to the geological map (1:10 000) of panarea and basiluzzo islands, aeolian arc, italy. acta vulcanologica, 11, 223-243. caliro s., caracausi a., chiodini g., ditta m., italiano f., longo m., minopoli c., nuccio p.m., paonita a., rizzo a. (2004) evidence of a new magmatic input to the quiescent volcanic edifice of panarea, aeolian islands, italy. geophysical research letters, 31, l07619. calvari s., cannavò f., bonaccorso a., spampinato l., pellegrino a.g. (2018) paroxysmal explosions, lava fountains and ash plumes at etna volcano: eruptive processes and hazard implications. frontiers in earth science, 6. doi: 10.3389/feart.2018.00107 cannata a., di grazia g., giuffrida m., gresta s., palano m., sciotto m., viccaro m., zuccarello f. (2018) space-time evolution of magma storage and transfer at mt. etna volcano (italy): the 2015-2016 reawakening of voragine crater. geochemistry geophysics geosystems, 19, 471-495. cannatelli c., lima a., bodnar r.j., de vivo b., webster j.d., fedele l. (2007) geochemistry of melt inclusions from the fondo riccio and minopoli 1 eruptions at campi flegrei (italy). chemical geology, 237, 418-432. capaccioni b., tassi f., vaselli o., tedesco d., poreda r. (2007) submarine gas burst at panarea island southern italy, on november 3, 2002: a magmatic versus hydrothermal episode. journal of geophysical research, 112, b05201. caporizzo c., di luccio d., tursi m.f., pappone g. (2022) coastal vs volcanic processes: procida island as a case of complex morpho-evolutive response. marine geology, 448, 106814. carapezza m.l., barberi f., tarchini l., ranaldi m., ricci t. (2010) volcanic hazards of the colli albani. the colli albani volcano, special volume geological society london, 3, 1-279. carbone s., lentini f. (1981) caratteri deposizionali delle vulcaniti del miocene superiore negli iblei (sicilia sud-orientale). geologica romana, 20, 79101. cardello g.l., consorti l., palladino d.m., carminati e., carlini m., doglioni c. (2020) tectonically controlled carbonate-seated maar-diatreme volcanoes: the case of the volsci volcanic field, central italy. journal of geodynamics, 139, 101763. casalbore d., romagnoli c., bosman a., de astis g., lucchi f., tranne c.a., chiocci f.l. (2018) multistage formation of la fossa caldera (vulcano island, italy) from an integrated subaerial and submarine analysis. marine geophysical research. doi: 10.1007/s11001-018-9358-3 casalini m., avanzinelli r., heumann a., de vita s., sansivero f., conticelli s., tommasini s. (2017) geochemical and radiogenic isotope probes of ischia volcano, southern italy: constraints on magma chamber dynamics and residence time. american mineralogist, 102, 262-274. catalano s., tortorici l., viccaro m. (2014) regional tectonic control on large size explosive eruptions: insights into the green tuff ignimbrite unit of pantelleria. journal of geodynamics, 73, 23-33. cavazza w., roure f., ziegler p.a. (2004) the mediterranean area and the surrounding regions: active processes, remnants of former tethyan oceans and related thrust belts. in the transmed atlas. the mediterranean region from crust to mantle, 1-29. 266 branca s. et al. springer, berlin, heidelberg. centamore e., dramis f., di manna p., fumanti f., milli s., rossi d., palombo m.r., palladino d.m., trigila r., zanon v., chiocchini m., didaskalou p., potetti m., nisio s. (2010) note illustrative del foglio 402 ceccano. carta geologica d’italia 1:50.000. servizio geologico d’italia, rome. chiarabba c., amato a., delaney p.t. (1997) crustal structure, evolution, and volcanic unrest of the alban hills, central italy. bulletin of volcanology, 59, 161-170. chiesa s., floris b., gillot p.y., prosperi l., vezzoli l. (1995) il vulcano di roccamonfina. in: enea (ed.), lazio meridionale. enea, 128-150. ciaranfi n., guida m., iaccarino g., pescatore t., pieri p., rapisardi l., ricchetti g., sgrosso i., torre m., tortorici l., turco e., scarpa r., cuscito m., guerra i., iannaccone g., panza g.f., scandone p. (1983) elementi sismotettonici dell'appennino meridionale. bollettino della società geologica italiana, 102, 201-222. cimarelli c., de rita d. (2006a) relatively rapid emplacement of dome-forming magma inferred from strain analyses: the case of the acid latian dome complexes (central italy). journal of volcanology and geothermal research, 158, 106-116. cimarelli c., de rita d. (2006b) structural evolution of the pleistocene cimini trachytic volcanic complex (central italy). bulletin of volcanology, 68, 538-548. cioni r., sbrana a., bertagnini a., buonasorte g., landi p., rossi u., salvati l. (1987) tephrostratigraphic correlations in the vulsini, vico and sabatini volcanic successions. periodico di mineralogia, 56, 137155. cioni r., laurenzi m.a., sbrana a., villa i.m. (1989) geochronology and stratigraphy of basal pyroclastites of the vulsini volcanic district. plinius european journal of mineralogy, 1, 46-47. cioni r., laurenzi m.a., sbrana a., villa i.m. (1993) 40ar/39ar chronostratigraphy of the initial activity in the sabatini volcanic complex (italy). bollettino della società geologica italiana, 112, 251-263. cioni r., santacroce r., sbrana a. (1999) pyroclastic deposits as a guide for reconstructing the multistage evolution of the somma-vesuvius caldera. bulletin of volcanology,61, 207-222. doi: 10.1007/s004450050272 cioni r., longo a., macedonio g., santacroce r., sbrana a., sulpizio r., andronico d. (2003) assessing pyroclastic fall hazard through field data and numerical simulations: example from vesuvius. journal of geophysical research, 108, 2063. doi: 10.1029/2001jb000642 cioni r., bertagnini a., santacroce r., andronico d. (2008) explosive activity and eruption scenarios at somma-vesuvius (italy): towards a new classification scheme. journal of volcanology and geothermal research, 178, 331-346. doi: 10.1016/j.jvolgeores.2008.04.024 civetta l., orsi g., scandone p., pece r. (1978) eastwards migration of the tuscan anatectic magmatism due to anticlockwise rotation of the apennines. nature, 276, 604-606. civetta l., cornette y., crisci g., gillot p.y., orsi g., requejos c.s. (1984) geology, geochronology and chemical evolution of the island of pantelleria. geological magazine, 121, 541-668. civetta l., cornette y., gillot p. y., orsi g. (1988) the eruptive history of pantelleria (sicily channel) in the last 50 ka. bulletin of volcanology, 50, 47-57. civetta l., carluccio e., innocenti f., sbrana a., taddeucci g. (1991a) magma chamber evolution under phlegraean fields during the last 10 ka: trace element and isotope data. european journal of mineralogy, 3, 415-428. civetta l., gallo g., orsi g. (1991b) srand ndisotope and trace-element constraints on the chemical evolution of the magmatic system of ischia (italy) in the last 55 ka. journal of volcanology and geothermal research, 46, 213-230. doi: 10.1016/0377-0273(91)90084-d civetta l., orsi g., pappalardo l., fisher r.v., heiken g.h., ort m. (1997) geochemical zoning, mixing, eruptive dynamics and depositional processes the campanian ignimbrite, campi flegrei, italy. journal of volcanology and geothermal research, 75, 183219. civile d., lodolo e., tortorici l., lanzafame g., brancolini g. (2008) relationships between magmatism and tectonics in a continental rift: the pantelleria island region (sicily channel, italy). marine geology, 251, 32-46. clocchiatti r., condomines m., guènot n., tanguy j.c. (2004) magma changes at mount etna: the 2001 and 2002-2003 eruptions. earth and planetary science letters, 226, 397-414. cole p.d., scarpati c. (1993) a facies interpretation of the eruption and emplacement mechanisms of the upper part of the neapolitan yellow tuff, campi flegrei, southern italy. bulletin of volcanology, 55, 311-326. cole p.d., guest j.e., duncan a.m. (1993) the emplacement of intermediate volume ignimbrites: a case study from roccamonfina volcano, southern italy. bulletin of volcanology, 55, 467-480. cole j.w., milner d.m., spinks k.d. (2005) calderas and caldera structures: a review. earth-science reviews, 69, 1-26. coltelli m., del carlo p., vezzoli l. (1998) the discovery of a plinian basaltic eruption of roman age at mt. etna volcano (italy). geology, 26, 1095-1098. coltelli m., del carlo p., vezzoli l. (2000) stratigraphic constraints for explosive activity in the last 100 ka at etna volcano, italy. international journal of earth sciences, 89, 665-677. coltelli m., cavallaro d., d’ anna g., d’ alessandro a., grassa f., mangano g., patanè d., gresta s. (2016) exploring the submarine graham bank in the sicily channel. annals of geophysics, 59, 2. doi: 10.4401/ag-6929 constantinescu r., robertson r., lindsay j.m., tonini r., sandri l., rouwet d., smith p., stewart r. (2016) application of the probabilistic model bet_unrest during a volcanic unrest simulation exercise in dominica, lesser antilles. geochemistry geophysics and geosystems, 17, 4438-4456. doi: 10.1002/2016gc006485 conte a.m., dolfi d. (2002) petrological and geochemi 267 the italian quaternary volcanism cal characteristics of plio-pleistocene volcanics from ponza island (tyrrhenian sea, italy). mineralogy and petrololgy, 74, 75-94. conte a.m., dolfi d., gaeta m., misiti v., mollo s., perinelli c. (2009) experimental constraints on evolution of leucite-basanite magma at 1 and 10-4 gpa: implications for parental compositions of roman high-potassium magmas. european journal of mineralogy, 21, 763-782. conte a.m., martorelli e., calarco m., sposato a., perinelli c., coltelli m., chiocci f.l. (2014) the 1891 submarine eruption offshore pantelleria island (sicily channel, italy): identification of the vent and characterization of products and eruptive style. geochemistry, geophysics, geosystems, 15, 6, 25555-2574 doi: 10.1002/2014gc005238 conte a.m., perinelli c., bianchini g., natali c., martorelli e., chiocci f.l. (2016) new insights on the petrology of submarine volcanics from the western pontine archipelago (tyrrhenian sea, italy). journal of volcanology and geothermal research, 327, 223239. conte a.m., perinelli c., bosman a., castorina f., conti a., cuffaro m., di vincenzo g., martorelli e., bigi s. (2020) -tectonics, dynamics and plio-pleistocene magmatism in central tyrrhenian sea: insights from the transitional submarine basalts of the ventotene volcanic ridge (pontine islands, italy). geochemistry, geophysics, geosystems, 21 (12). doi: 10.1029/2020gc009346 conticelli s. (1998) effects of crustal contamination on ultrapotassic magmas with lamproitic affinity: mineralogical, geochemical and isotope data from the torre alfina lavas and xenoliths, central italy. chemical geology, 149, 51-81. conticelli s., peccerillo a. (1990) petrological significance of high-pressure ultramafic xenoliths from ultrapotassic rocks of central italy. lithos, 24, 305322. doi: 10.1016/0024-4937(89)90050-9 conticelli s., peccerillo a. (1992) potassic and ultrapotassic volcanism from central italy: compositional characteristics, petrogenesis and inferences on the evolution of the mantle source. lithos, 28, 221-240. doi: 10.1016/0024-4937(92)90008-m conticelli s., francalanci l., manetti p., peccerillo a. (1987) evolution of latera volcano: evidence from major and trace element chemistry of pyroclastic rocks. periodico di mineralogia, 56, 175-199. conticelli s., francalanci l., santo a.p. (1991) petrology of the final stage latera lavas: mineralogical, geochemical and sr-isotopic data and their bearing on the genesis of some potassic magmas in central italy. journal volcanology and geothermal research, 46, 187-212. doi: 10.1016/0377-0273(91)90083-c conticelli s., manetti p., menichetti s. (1992) petrology, chemistry, mineralogy and sr-isotopic features of pliocenic orendites from south tuscany: implications on their genesis and evolutions. european journal of mineralogy, 4, 1359-1375. conticelli s., francalanci l., manetti p., cioni r., sbrana a. (1997) petrology and geochemistry of the ultrapotassic rocks from the sabatini volcanic district, central italy: the role of evolutionary processes in the genesis of variably enriched alkaline magmas. journal of volcanology and geothermal research, 75, 107-136. conticelli s., bortolotti v., principi g., laurenzi m.a., vagelli g., d'antonio m. (2001) petrology, mineralogy and geochemistry of a mafic dyke from monte castello, elba island, italy. ofioliti 26, 249-262. conticelli s., d'antonio m., pinarelli l., civetta l. (2002) source contamination and mantle heterogeneity in the genesis of italian potassic and ultrapotassic volcanic rocks: sr-nd-pb isotope data from roman province and southern tuscany. mineralogy and petrology, 74, 189-222. doi: 10.1007/s007100200004 conticelli s., melluso l., perini g., avanzinelli r., boari e. (2004) petrologic, geochemical, and isotopic characteristics of potassic and ultrapotassic magmatism in central-southern italy: inferences on its genesis and on the nature of mantle sources. periodico di mineralogia 73, 153-164. conticelli s., guarnieri l., farinelli a., mattei m., avanzinelli r., bianchini g., boari e., tommasini s., tiepolo m., prelević d., venturelli g. (2009a) trace elements and sr-nd-pb isotopes of k-rich, shoshonitic, and calc-alkaline magmatism of the western mediterranean region: genesis of ultrapotassic to calc-alkaline magmatic associations in a post-collisional geodynamic setting. lithos, 107, 6892. conticelli s., marchionni s., rosa d., giordano g., boari e., avanzinelli r. (2009b) shoshonite and subalkaline magmas from an ultrapotassic volcano: srnd-pb isotope data on the roccamonfina volcanic rocks, roman magmatic province, southern italy. contribution to mineralogy and petrology, 157, 4163. conticelli s., laurenzi m.a., giordano g., mattei m., avanzinelli r., melluso l., tommasini s., boari e., cifelli f., perini g. (2010) leucite-bearing (kamafugitic/leucititic) and-free (lamproitic) ultrapotassic rocks and associated shoshonites from italy: constraints on petrogenesis and geodynamics. journal of virtual explorer, 36, 1-95. conticelli s., avanzinelli r., marchionni s., tommasini s., melluso l. (2011) sr-nd-pb isotopes from the radicofani volcano, central italy: constraints on heterogeneities in a veined mantle responsible for the shift from ultrapotassic shoshonite to basaltic andesite magmas in a post-collisional setting. mineralogy and petrology, 103, 123-148. conticelli s., avanzinelli r., poli g., braschi e., giordano g. (2013) shift from lamproite-like to leucititic rocks: sr-nd-pb isotope data from the monte cimino volcanic complex vs. the vico stratovolcano, central italy. chemical geology, 353, 246-266. conticelli s., avanzinelli r., ammannati e., casalini m. (2015a) the role of carbon from recycled sediments in the origin of ultrapotassic igneous rocks in the central mediterranean. lithos, 232, 174-196. conticelli s., boari e., burlamacchi l., cifelli f., moscardi f., laurenzi m.a., ferrari pedraglio l., francalanci l., benvenuti m.g., braschi e., manetti p. (2015b) 268 branca s. et al. geochemistry and sr-nd-pb isotopes of monte amiata volcano, central italy: evidence for magma mixing between high-k calc-alkaline and leucititic mantle-derived magmas. italian journal of geosciences, 134, 266-290. corsaro r.a., cristofolini r. (1997) geology, geochemistry and mineral chemistry of tholeiitic to transitional etnean magmas. acta vulcanologica, 9, 55-66. corsaro r.a., cristofolini r. (2000) subacqueous volcanism in the etnean area: evidence for hydromagmatic acticity and regional uplift inferred from the castle rock of acicastello. journal of volcanology and geothermal research, 95, 209-225. corsaro r.a., cristofolini r., patanè l. (1996) the 1669 eruption at mount etna: chronology, petrology and geochemistry, with inferences on the magma sources and ascent mechanisms. bulletin of volcanology, 58, 348-358. corsaro r.a., andronico d., behncke b., branca s., caltabiano t., ciancitto f., cristaldi a., de beni e., la spina a., lodato l., miraglia l., neri m., salerno g., scollo s., spata g. (2017) -monitoring the december 2015 summit eruptions of mt. etna (italy): implications on eruptive dynamics. journal of volcanology and geothermal research, 341, 53-69. cortini m., scandone r. (1982) feeding system of vesuvius between 1754 and 1944. journal of volcanology and geothermal research, 12, 393-400. costa a., dell’erba f., di vito m.a., isaia r., macedonio g., orsi g., pfeiffer t. (2009) tephra fallout hazard assessment at the campi flegrei caldera (italy). bulletin of volcanology, 71, 259-273. doi: 10.1007/s00445-008-0220-3 costa g., mereu l., prestifilippo m., scollo s., viccaro m. (2023) modeling the trajectories of ballistics in the summit area of mt. etna (italy) during the 20202022 sequence of lava fountains. geosciences, 13 (5), 145. crisci g., de fino m., la volpe l., rapisardi l. (1983) pleistocene ignimbrites of monte vulture (basilicata, southern italy). neues jahrbuch für geologie und paläontologie, 12, 731-746. crisci g.m., de franesco a.m., mazzuoli r., poli g., stanzione d. (1989) geochemistry of recent volcanics of ischia island, italy: evidences of fractional crystallization and magma mixing. chemical geology, 78, 15-33. crocitti m., sulpizio r., insinga d.d., de rosa r., donato p., iorio m., zanchetta g., barca d., lubritto c. (2019) on ash dispersal from moderately explosive volcanic eruptions: examples from holocene and late pleistocene eruptions of italian volcanoes. journal of volcanology and geothermal research 385, 198-221. cristofolini (1966) le manifestazioni eruttive basiche del trias superiore nel sottosuolo di ragusa. periodico di mineralogia, 35, 1-38. cristofolini r., ghisetti f., scarpa r., vezzani l. (1985) character of the stress field in the calabrian arc and southern apennines (italy) as deduced by geological, seismological and volcanological information. tectonophysics, 117, 39-58. cross j.k., tomlinson e.l., giordano g., smith v.c., de benedetti a.a., roberge j., manning c.j., wulf s., menzies m.a. (2014) high level triggers for explosive mafic volcanism: albano maar, italy. lithos, 190, 137-153. cuffaro m., martorelli e., bosman a., conti a., bigi s., muccini f., cochi l., ligi m., bortoluzzi g., scrocca d., canese s., chiocci f.l., conte a.m., doglioni d., perinelli c. (2016) the ventotene volcanic ridge: newly explored complex in the central tyrrhenian sea (italy). bulletin of volcanology, 78, 86. d'alessandro a., mangano g., d'anna g. (2012) evidence of persistent seismo-volcanic activity at marsili seamount. annals of geophysics, 55, 213-214. d'ambrosio e., giaccio b., lombardi l., marra f., rolfo m.f., sposato a. (2010) l'attività recente del centro eruttivo di albano tra scienza e mito: un'analisi critica del rapporto tra il vulcano laziale e la storia dell'area albana lazio e sabina, sesto incontro di studi sul lazio e sabina, roma, 125-136. d’antonio m., civetta l., orsi g., pappalardo l., piochi m., carandente a., de vita s., di vito m.a., isaia r., southon j. (1999) the present state of the magmatic system of the campi flegrei caldera based on the reconstruction of its behaviour in the past 12 ka. journal of volcanology and geothermal research, 91 (2-4), 247-268. d’antonio m., tonarini s., arienzo i., civetta l., di renzo v. (2007) components and processes in the magma genesis of the phlegrean volcanic district, southern italy. in: beccaluva l., bianchini g., wilson m. (eds.) cenozoic volcanism in the mediterranean area. geological society of america special paper, 418, 203-220. doi: 10.1130/2007.2418(10) d’argenio b., pescatore t., scandone p. (1973) schema geologico dell’appennino meridionale. atti del convegno “moderne vedute sulla geologia dell’appennino”. accademia nazionale dei lincei, 183, 4972. d’antonio m., arienzo i., brown r.j., petrosino p., pelullo c., giaccio b. (2021) petrography and mineral chemistry of monte epomeo green tuff, ischia island, south italy: constraints for identification of the y-7 tephrostratigraphic marker in distal sequences of the central mediterranean. minerals 11, 9. de astis g., ventura g., vilardo g. (2003) geodynamic significance of the aeolian volcanism (southern tyrrhenian sea, italy) in light of structural, seismological and geochemical data. tectonics, 22, 10401057. de astis g., pappalardo l., piochi m. (2004) procida volcanic history: new insights into the evolution of the phlegraean volcanic district (campania region, italy). bulletin of volcanology, 66, 622-641. de astis g., lucchi f., dellino p., la volpe l., tranne c.a., frezzotti m.l., peccerillo, a. (2013) geology, volcanic history and petrology of vulcano (central aeolian archipelago). geological society, london, memoirs, 37, 281-348. de benedetti a.a., funiciello r., giordano g., diano g., caprilli e., paterne m. (2008) volcanology, history and myths of the lake albano maar (colli albani volcano, italy). journal of volcanology and geo 269 the italian quaternary volcanism thermal research, 176(3), 387-406. de beni e., branca s., coltelli m., groppelli g., wijbrans j. (2011) 39ar/40ar isotopic dating of etna volcanic succession. italian journal of geosciences, 130, 3, 292-305. de fino m., la volpe l., piccarreta g. (1982) magma evolution at mt. vulture (southern italy). bulletin of volcanology, 45, 115-126. de fiore o. (1922) vulcano (isole eolie). rivista vulcanologica i. friedlaender 3, 1-393. deino a.l., orsi g., piochi m., de vita s. (2004) the age of the neapolitan yellow tuff caldera-forming eruption (campi flegrei caldera italy) assessed by 40ar/39ar dating method. journal of volcanology and geothermal research, 133,157-170 del carlo p., branca s., d’oriano c. (2017) new findings of etna pumice fall deposits in ne sicily and implications for distal tephra correlations in the mediterranean area. bulletin of volcanology, 75, 50. del negro c., cappello a., neri m., bilotta g., herault a., ganci g. (2013) lava flow hazards at mount etna: constraints imposed by eruptive history and numerical simulations. scientific reports, 3, 3493. de rita d., giordano g. (1996) volcanological and structural evolution of roccamonfina volcano (italy): origin of the summit caldera. geological society of london special publications, 110(1), 209 -224. de rita d., funiciello r., pantosti d., salvini f., sposato a., velonà m. (1986) geological and structural characteristics of the pontine islands (italy) and implications with the evolution of the tyrrhenian margin. memorie della sociatà geologica italiana, 36, 55-65. de rita d., funiciello r., parotto m. (1988) geological map of the colli albani volcanic complex. progetto finalizzato geodinamica c.n.r., rome, italy. de rita d., funiciello r., corda l., sposato a., rossi u. (1993) volcanic units. in: di filippo m. (ed.), sabatini volcanic complex. quad. ric. sci., 114, 3379. progetto finalizzato geodinamica c.n.r., roma. de rita d., faccenna c., funiciello r., rosa c. (1995a) stratigraphy and volcano-tectonics. in: trigila, r. (ed.), the volcano of the alban hills. università degli studi di roma "la sapienza", rome, italy, 3371. de rita d., giordano g., rosa c., sheridan m.f. (1995) volcanic risk at the alban hills volcano and numerical simulations. the volcano of the alban hills. tipografia sgs, roma, 267-283. de rita d., di filippo m., rosa c. (1996) structural evolution of the bracciano volcano-tectonic depression, sabatini volcanic district, italy. in: mcguire w.j., jones a.p., neuberg j. (eds.), volcano instability on the earth and other planets. geological society of london special publications, 225-236. de rita d., giordano g., cecili a. (2001) a model for submarine rhyolite dome growth: ponza island (central italy). journal of volcanology and geothermal research, 107, 221-239. de rosa r., mazzuoli r., scribano v., trua t. (1991) nuovi dati petrologici sulle vulcaniti dei monti iblei (sicilia sud-orientale): implicazioni genetiche e geotettoniche. mineralogica et petrografica acta, 34, 133-151. de vita s., laurenzi m.a., orsi g., voltaggio m. (1998) application of 40ar/39ar and 230th dating methods to the chronostratigraphy of quaternary basaltic volcanic areas: the ustica island case history. quaternary international, 4 (48), 117-127. de vita s., sansivero f., orsi g., marotta e. (2006) cyclical slope instability and volcanism related to volcano-tectonism in resurgent calderas: the ischia island (italy) case study. engineering geology, 86, 148-165. de vita s., sansivero f., orsi g., marotta e., piochi m. (2010) volcanological and structural evolution of the ischia resurgent caldera (italy) over the past 10 ky. in groppelli g., viereck-goette l. (eds.), stratigraphy and geology of volcanic areas. geologica society of america special papers, 464, 193-241. doi: 10.1130/2010.2464 de vita s., di vito m., gialanella c., sansivero f. (2013) the impact of the ischia porto tephra eruption (italy) on the greek colony of pithekoussai. quaternary international, 303, 142-52. de vivo b., rolandi g., gans p.b., calvert a., bohrson w.a., spera f.j., belkin h.e. (2001) new constraints on the pyroclastic eruptive history of the campanian volcanic plain (italy). mineralogy and petrology, 73, 47-65. di girolamo p., ghiara m.r., lirer l., munno r., rolandi g., stanzione d. (1984) vulcanologia e petrologia dei campi flegrei. bollettino della società geologica italiana, 103,349-413 di capua a., vezzoli g., groppelli g. (2016) climatic, tectonic and volcanic controls of sediment supply to an oligocene foredeep basin: the val d’aveto formation (northern italian apennines). sedimentary geology, 332, 68-84 di renzo v., civetta l., d’antonio m., tonarini s., di vito m.a., orsi g. (2011) the magmatic feeding system of the campi flegrei caldera: architecture and termporal evolution. chemical geology, 281,227241. doi: 10.1016/j.chemgeo.2010.12.010 di rita f., sottili g. (2019) pollen analysis and tephrochronology of a mis 13 lacustrine succession from eastern sabatini volcanic district (rignano flaminio, central italy). quaternary science reviews, 204, 78-93. di rocco t., freda c., gaeta m., mollo s., dallai l. (2012) magma chambers emplaced in carbonate substrate: petrogenesis of skarn and cumulate rocks and implications for co2 degassing in volcanic areas. journal of petrology, 53, 2307-2332. disperati l., liotta d. (1998) estimating uplift of clayfilled extensional basins through the porosity depth curve: the case of the radicofani basin (italy). annals of tectonics, 12, 162-176. di vito m.a., isaia r., orsi g., southon j., de vita s., d’antonio m., pappalardo l., piochi m. (1999) volcanic and deformation history of the campi flegrei caldera in the past 12 ka. journal of volcanology and geothermal research, 91, 221-246. di vito m.a., acocella v., aiello g., barra d., battaglia 270 branca s. et al. m., carandente a., del gaudio c., de vita s., ricciardi g.p., ricco c., scandone r., terrasi f. (2016) magma transfer at campi flegrei caldera (italy) before the 1538 ad eruption, scientific reports, 6, 32245, 1-9. doi: doi. org/ 10. 1038/ srep3 2245 dolfi d., conte a.m. (2018) vii-caratteri mineralogici e petrochimici delle vulcaniti delle isole pontine occidentali (ponza, zannone, palmarola). in: note illustrative della carta geologica d’italia alla scala 1:50.000. foglio 413, borgo grappa isole ponziane. ispradipartimento per il servizio geologico d’italia, 2018. d’orazio m., laurenzi m.a., villa i.m. (1991) 40ar/39ar dating of a shoshonitic lava flow of the radicofani volcanic center (southern tuscany). acta vulcanologica, 1, 63-67. d'oriano c., poggianti e., bertagnini a., cioni r., landi p., polacci m., rosi m. (2005) changes in eruptive style during the a.d. 1538 monte nuovo eruption (phlegrean fields, italy): the role of syneruptive crystallization. bulletin of volcanology, 67, 601-621. d’orazio m., innocenti f., tonarini s., doglioni c. (2008) reply to the discussion of “carbonatites in a subduction system: the pleistocene alvikites from mt. vulture (southern italy)“ by d’orazio m., innocenti f., tonarini s., doglioni c. (lithos 98, 313-334) by stoppa f., principe c., giannandrea p., lithos, 103, 557-561. doronzo d.m., di vito m.a., arienzo i., bini m., calusi b., cerminara m., corradini s., de vita s., giaccio b., gurioli l., mannella g., ricciardi g.p., rucc i., sparice d., todesco m., trasatti e., zanchetta g. (2022) the 79 ce eruption of vesuvius: a lesson from the past and the need of a multidisciplinary approach for developments in volcanology. earthscience reviews 231, 104072. downes h., kostoula t., jones a.p., beard a.d., thirlwall m.f., bodinier j.-l. (2002) geochemistry and sr-nd isotopic compositions of mantle xenoliths from the monte vulture carbonatite-melilitite volcano, central southern italy. contribution to mineralogy and petrology, 144, 78-92. evernden j.f., curtis g.h. (1965) the potassium-argon dating of late cenozoic rocks in east africa and italy. current antropology, 6, 343-385. faccenna c., becker t.w., lucente f.p., jolivet l., rossetti f. (2001a) history of subduction and back arc extension in the central mediterranean. geophysical journal international, 145(3), 809-820. faccenna c., funiciello f., giardini d., lucente p. (2001b) episodic back-arc extension during restricted mantle convection in the central mediterranean. earth and planetary science letters, 187, 105-116. faccenna c., piromallo c., crespo-blanc a., jolivet l., rossetti f. (2004) lateral slab deformation and the origin of the western mediterranean arcs. tectonics, 23, tc1012. doi:10.1029/2002tc001488, 2004 fazzini p., gelmini r., mantovani m.p., pellegrini m. (1972) geologia dei monti della tolfa (lazio settentrionale, province di viterbo e roma). memorie società geologica italiana, 11, 65-144. fedele l., scarpati c., lanphere m., melluso l., morra v., perrotta a., ricci g. (2008) the breccia museo formation, campi flegrei, southern italy: geochronology, chemostratigraphy and relationship with the campanian ignimbrite eruption. bulletin of volcanology, 70, 1189-1219. fedele l., morra v., perrotta a., scarpati c., sbrana a., putignano m. l., orrù p., schiattarella m., aiello g., d’argenio b., conforti a. (2012) note illustrative della carta geologica dell’isola di procida alla scala 1: 10.000-foglio 465-464. ferlito c., viccaro m., nicotra e., cristofolini r. (2010) relationship between the flank sliding of the south east crater (mt. etna, italy) and the paroxysmal event of november 16, 2006. bulletin of volcanology, 72, 1179-1190. ferlito c., viccaro m., nicotra e., cristofolini r. (2012) regimes of magma recharge and their control on the eruptive behaviour during the 2001-2005 period at mt. etna (italy). bulletin of volcanology, 74, 533543. ferrari l., conticelli s., burlamacchi l., manetti p. (1996) volcanological evolution of the monte amiata volcanic center, southern tuscany, central italy: new geological and petrochemical data. acta vulcanologica, 8, 41-56. finetti i., morelli c. (1974) esplorazione sismica a riflessione dei golfi di napoli e pozzuoli. bollettino di geofisica teorica e applicata, 16, 175-222. fisher r.v., orsi g., ort m., heiken g. (1993) mobility of a large-volume pyroclastic flow: emplacement of the campanian ignimbrite, italy. journal of volcanology and geothermal research, 56, 205-220. folch a., sulpizio r. (2010) evaluating long-range volcanic ash hazard using supercomputing facilities: application to somma-vesuvius (italy), and consequences for civil aviation over the central mediterranean area. bulletin of volcanology, 79, 10391059. forni f., lucchi f., peccerillo a., tranne c.a., rossi, p.l., frezzotti m.l. (2013) stratigraphy and geological evolution of the lipari volcanic complex (central aeolian archipelago). geological society, london, memoirs, 37, 213-279. forni f., petricca e., bachmann o., mollo s., de astis g., piochi m. (2018) the role of magma mixing/ mingling and cumulate melting in the neapolitan yellow tuff caldera-forming eruption (campi flegrei, southern italy). contribution to mineralogy and petrology, 173, 45. fourmentraux c., metrich n., bertagnini a., rosi m. (2012) crystal fractionation, magma step ascent, and syn-eruptive mingling; the averno 2 eruption (phlegraean fields, italy). contribution to mineralogy and petrology, 163, 6, 1121-1137. fowler j., spera f., bohrson w., belkin h.e., de vivo b. (2007) phase equilibria constraints on the chemical and physical evolution of the campanian ignimbrite. journal of petrology, 48, 459-493. francalanci l., lucchi f., keller j., de astis g., tranne c.a. (2013) eruptive, volcano-tectonic and magmatic history of the stromboli volcano (northeastern aeolian archipelago). geological society, 271 the italian quaternary volcanism london, memoirs, 37, 395-469. freda c., gaeta m., palladino d.m., trigila r. (1997) the villa senni eruption (alban hills, central italy): the role of h2o and co2 on the magma chamber evolution and on the eruptive scenario. journal of volcanology and geothermal research, 78, 103120. freda c., gaeta m., karner d.b., marra f., renne p.r., taddeucci j., scarlato p., christensen j.n., dallai l. (2006) eruptive history and petrologic evolution of the albano multiple maar (alban hills, central italy). bulletin of volcanology, 68, 567-591. freda c., gaeta m., misiti v., mollo s., dolfi d., scarlato p. (2008) magma-carbonate interaction: an experimental study on ultrapotassic rocks from alban hills (central italy). lithos, 101, 397-415. freda c., gaeta m., giaccio b., marra f., palladino d.m., scarlato p., sottili g. (2011) co2-driven large mafic explosive eruptions: a case study from the colli albani (central italy). bulletin of volcanology, 73, 241-256. funiciello r., giordano g., de rita d. (2003) the albano maar lake (colli albani volcano, italy): recent volcanic activity and evidence of pre-roman age catastrophic lahar events. journal of volcanology and geothermal research, 123, 43-61. gaeta m. (1998) petrogenetic implications of basanidine in the lionato tuff (colli albani volcanic district, central italy). mineralogical magazine, 62, 697-701. gaeta m., freda c. (2001) strontian fluoromagnesiohastingsite in alban hills lavas (central italy): constraints on crystallization conditions. mineralogical magazine, 65, 787-795. gaeta m., fabbrizio g., cavarretta g. (2000) fphlogopites in the alban hills volcanic district (central italy): indications regarding the role of volatiles in magmatic crystallization. journal of volcanology and geothermal research, 99, 179-193. gaeta m., freda c., christensen j.n., dallai l., marra f., karner d.b., scarlato p. (2006) time-dependent geochemistry of clinopyroxene from the alban hills (central italy): clues to the source and evolution of ultrapotassic magmas. lithos, 86, 330-346. gaeta m., di rocco t., freda c. (2009) carbonate assimilation in open magmatic systems: the role of melt-bearing skarns and cumulate-forming processes. journal of petrology, 50, 361-385. gaeta m., freda c., marra f., arienzo i., gozzi f., jicha b., di rocco t. (2016) paleozoic metasomatism at the origin of mediterranean ultrapotassic magmas: constraints from time-dependent geochemistry of colli albani volcanic products (central italy). lithos, 244, 151-64. gaeta m., bonechi b., marra f., perinelli c. (2021) uncommon k‐foiditic magmas: the case study of tufo del palatino (colli albani volcanic district, italy). lithos, 396-397 (106): 239. galli p., giaccio b., messina p., peronace e., amato v., naso j., nomade s., pereira a., piscitelli s., bellanova j., billi a., blamart d., galderisi a., giocoli a., stabile t., thil f. (2017) middle to late pleistocene activity of the northern matese fault system (southern apennines, italy). tectonophysics, 699, 61-81. gasparini p., adams j.a.s. (1967) k-ar dating of italian plio-pleistocene volcanic rocks. earth and planetary science letters, 6, 225-230. gasparon m., rosenbaum g., wijbrans j., manetti p. (2009) the transition from subduction arc to slab tearing: evidence from capraia island, northern tyrrhenian sea. journal of geodynamics, 47, 3038. ghinassi m., lazzarotto a. (2005) different source areas feeding the early pliocene marine radicofani basin (siena): geological and paleogeographical implications. bollettino della società geologica italiana, 3, 15-28. giaccio b., sposato a., gaeta m., marra f., palladino d.m., taddeucci j., barbieri m., messina p., rolfo m.f. (2007) mid-distal occurrences of the albano maar pyroclastic deposits and their relevance for reassessing the eruptive scenarios of the most recent activity at the colli albani volcanic district, central italy. quaternary international, 171(172), 160-178. giaccio b., isaia r., fedele f.g., di canzio e., hoffecker j., ronchitelli a., sinitsyn a.a., anikovich m., lisitsyn s.n., popov v.v. (2008) the campanian ignimbrite and codola tephra layers: two temporal/ stratigraphic markers for the early upper palaeolithic in southern italy and eastern europe. journal of volcanology and geothermal research, 177 (1), 208-226. doi: 10.1016/j.jvolgeores.2007.10.007 giaccio b., marra f., hajdas i., karner d.b., renne p.r., sposato a. (2009) 40ar/39ar and 14c geochronology of the albano maar deposits: implications for defining the age and eruptive style of the most recent explosive activity at the alban hills volcanic district, italy. journal of volcanology and geothermal research, 185, 203-213. giaccio b., nomade s., wulf s., isaia r., sottili g., cavuoto g., galli p., messina p., sposato a., sulpizio r., zanchetta g. (2012) the late mis 5 mediterranean tephra markers: a reappraisal from peninsular italy terrestrial records. quaternary science reviews, 56, 31-45. giaccio b., arienzo i., sottili g., castorina f., gaeta m., nomade s., galli p., messina p. (2013a) isotopic (sr-nd) and major element fingerprinting of distal tephras: an application to the middle-late pleistocene markers from the colli albani volcano, central italy. quaternary science reviews, 67, 190-206. giaccio b., castorina f., nomade s., scardia g., voltaggio m., sagnotti l. (2013b) revised chronology of the sulmona lacustrine succession, central italy. journal of quaternary science, 28, 545-551. giaccio b., galli p., peronace e., arienzo i., nomade s., cavinato g.p., mancini m., messina p., sottili g. (2014) a 560-440 ka tephra record from the mercure basin, southern italy: volcanological and tephrostratigraphic implications. journal of quaternary science, 29, 232-248. giaccio b., regattieri e., zanchetta g., nomade s., renne p.r., sprain c.j., drysdale r.n., tzedakis p.c., messina p., scardia g., sposato a., bassinot 272 branca s. et al. https://doi.org/10.1016/j.jvolgeores.2007.10.007 f. (2015) duration and dynamics of the best orbital analogue to the present interglacial. geology, 43, 603-606. giaccio b., niespolo e.m., pereira a., nomade s., renne p.r., albert p.g., arienzo i., regattieri e., wagner b., zanchetta g., gaeta m., galli p., mannella g., peronace e., sottili g., florindo f., leicher n., marra f., tomlinson e.l. (2017a) first integrated tephrochronological record for the last ca. 190 kyr from the fucino quaternary lacustrine succession, central italy. quaternary science reviews, 158, 211-234. giaccio b., hajdas i., isaia r., deino a., nomade s. (2017b) high-precision 14c dating and 40ar/39ar dating of the campanian ignimbrite (y-5) reconciles the time-scales of climatic-cultural processes at 40 ka. scientific reports, 7, 45940. doi: 10.1038/srep45940 giaccio b., leicher n., mannella g., monaco l., regattieri e., wagner b., zanchetta g., gaeta m., marra f., nomade s., palladino d.m., pereira a., scheidt s., sottili g., wonik t., wulf s., zeeden c., ariztegui d., cavinato g.p., dean j.r., florindo f., leng m.j., macrì p., niespolo e., renne p.r., rolf c., sadori l., thomas c., tzedakis p.c. (2019) extending the tephra and palaeoenvironmental record of the central mediterranean back to 430 ka: a new core from fucino basin, central italy. quaternary science reviews, 225, 106003. giannandrea p., la volpe l., principe c., schiattarella m. (2006) unità stratigrafiche a limiti inconformi e storia evolutiva del vulcano medio-pleistocenico di monte vulture (appennino meridionale, italia). bollettino della società geologica italiana, 125, 67-92. giannetti b. (1996a) the geology of the yellow trachytic tuff, roccamonfina volcano. journal of volcanology and geothermal research, 71 (1), 53-72. giannetti b. (1996b) volcanology of trachytic and associated basaltic pyroclastic deposits at roccamonfina volcano, roman region. italy. journal of volcanology and geothermal research, 71 (2-4), 229248. giannetti b. (2001) origin of the calderas and evolution of roccamonfina volcano (roman region, italy). journal of volcanology and geothermal research, 106(3-4), 301-319. giannetti b., de casa g. (2000) stratigraphy, chronology, and sedimentology of ignimbrites from the white trachytic tuff, roccamonfina volcano, italy. journal of volcanology and geothermal research, 96(3-4), 243-295. giano s.i., pescatore e., biscione m., masini e., bentivenga m. (2022) geoand archaeo-heritage in the mount vulture area: list, data management, communication, and dissemination. a preliminary note. geoheritage, 14, 10. gillot p.-y., keller j. (1993) radiochronological dating of stromboli. acta vulcanologica, 3, 69-77. gillot p.y., kieffer g., romano r. (1994) the evolution of mount etna in the light of potassium-argon dating. acta vulcanologica 5, 81-87. giordano g. (1998a) facies characteristics and magma -water interaction of the white trachytic tuffs (roccamonfina volcano, southern italy). bulletin of volcanology, 60, 10-26. giordano g. (1998b) the effect of paleotopography on lithic distribution and facies associations of small volume ignimbrites: the wtt cupa (roccamonfina volcano, italy). journal of volcanology and geothermal research, 87(1-4), 255-273. giordano g., carg team (2010) stratigraphy, volcano tectonics and evolution of the colli albani volcanic field. in: r. funiciello, g. giordano (eds.), the colli albani volcano, special publications of iavcei, 3, geological society of london, london, 43-98. giordano g., de astis g. (2021) the summer 2019 basaltic vulcanian eruptions (paroxysms) of stromboli. bulletin of volcanology, 83, 1. doi: 10.1007/s00445-020-01423-2 giordano g., caricchi l. (2022) determining the state of activity of transcrustal magmatic systems and their volcanoes. annual review earth and planetary science, 50, 231-259. giordano g., de rita d., cas r., rodani s. (2002) valley pond and ignimbrite veneer deposits in the small-volume phreatomagmatic ‘peperino albano’basic ignimbrite, lago albano maar, colli albani volcano, italy: influence of topography. journal of volcanology and geothermal research, 118 (1-2), 131-144. giordano g., de benedetti a.a., diana a., diano g., gaudioso f., marasco f., miceli m., mollo s., cas r.a.f., funiciello r. (2006) the colli albani mafic caldera (roma, italy): stratigraphy, structure and petrology. journal of volcanology and geothermal research, 155, 49-80. giuffrida m., viccaro m. (2017) three years (20112013) of eruptive activity at mt. etna: working modes and timescales of the modern volcano plumbing system from microanalytical studies of crystals. earth science reviews, 171, 289-322. giuffrida m., viccaro m., ottolini l. (2018) ultrafast syneruptive degassing and ascent trigger high-energy basic eruptions. scientific reports, 8, 147. giuffrida m., nicotra e., viccaro m. (2020) changing modes and rates of mafic magma supply at pantelleria (sicily channel, southern italy): new perspectives on the volcano factory drawn upon olivine records. journal of petrology, 61 (5), egaa051. giuffrida g., scandura m., costa g., zuccarello f., sciotto m., cannata a., viccaro m. (2021) tracking the summit activity of mt. etna volcano between july 2019 and january 2020 by integrating petrological and geophysical data. journal of volcanology and geothermal research, 418, 107350. gozzi f., gaeta m., freda c., mollo s., di rocco t., marra f., dallai l., pack a. (2014) primary magmatic calcite reveals origin from crustal carbonate. lithos, 190-191, 191-203. granieri d., carapezza m.l., chiodini g., avino r., caliro s., ranaldi m., ricci t., tarchini l. (2006) correlated increase in co2 fumarolic content and diffuse emission from la fossa crater (vulcano, italy): evidence of volcanic unrest or increasing gas release from a stationary deep magma body? geophysical research letters, 33, l13316. groppelli g., viereck-goette l. (eds.) (2010) stratigraphy and geology of volcanic areas. the geological 273 the italian quaternary volcanism https://doi.org/10.1038/srep45940 https://doi.org/10.1007/s00445-020-01423-2 https://doi.org/10.1007/s00445-020-01423-2 society of america special paper, pp. 464. isbn 978-0-8137-2464-5 günther j., prelević d., mertz d., rocholl a., mertzkraus r., conticelli s. (2023) subduction-legacy and olivine monitoring for mantle-heterogeneities of the sources of ultrapotassic magmas: the italian case study. geochemistry, geophysics, geosystems, 24. doi: 10.1029/2022gc010709 gurioli l., sulpizio r., cioni r., sbrana a., santacroce r., luperini w., andronico d. (2010) pyroclastic flow hazard assessment at somma-vesuvius based on the geological record. bulletin of volcanology, 72, 1021-1038. doi: 10.1007/s00445-010-0379-2 harris a.j.l., steffke a., calvari s., spampinato l. (2011) thirty years of satellite-derived lava discharge rates at etna: implications for steady volumetric output. journal of geophysical research, 116, b08204. hieke merlin o. (1964) le vulcaniti del settore orientale del monte vulture (lucania). memorie dell’istituto di geologia e mineralogia dell’università di padova, xxvi, 3-67. hieke merlin o. (1967) i prodotti vulcanici del monte vulture (lucania). memorie dell’istituto di geologia e mineralogia dell’università di padova, 26, 1-67. hornig-kjarsgaard i., keller j., koberski u., stadlbauer e., francalanci l., lenhart r. (1993) geology, stratigraphy and volcanological evolution of the island of stromboli, aeolian arc, italy. acta vulcanologica, 3, 21-68. iezzi g., caso c., ventura g., vallefuoco m., cavallo a., behrens h., mollo s., paltrinieri d., signanini p., vetere f. (2014) first documented deep submarine explosive eruptions at the marsili seamount (tyrrhenian sea, italy): a case of historical volcanism in the mediterranean sea. gondwana research, 25, 764-774. ippolito f., ortolani f., russo m. (1973) struttura marginale tirrenica dell’appennino campano: reinterpretazione di dati di ricerche di idrocarburi. memorie della società geologica italiana, 12, 228-249. iurino d.a., mecozzi b., iannucci a., moscarella a., strani f., bona f., gaeta m., sardella r. (2022) a middle pleistocene wolf from central italy provides insights on the first occurrence of canis lupus in europe. scientific reports, 12(1), 2882. jolivet l., faccenna c., d’agostino n., fournier m., worrall d. (1999) the kinematics of back-arc basins, examples from the tyrrhenian, aegean and japan seas. geological society, london, special publications, 164(1), 21-53. jones a.p., kostoula t., stoppa f., wolley a.r. (2000) petrography and mineral chemistry of mantle xenoliths in a carbonate-rich melilitic tuff from mt. vulture volcano, southern italy. mineralogical magazine, 64, 341-361. jordan n.j., rotolo s.g., williams r., speranza f., mcintosh wc., branney mj., scaillet s. (2018) explosive eruptive history of pantelleria, italy: repeated caldera collapse and ignimbrite formation at a peralkaline volcano. journal of volcanology and geothermal research, 349, 67-73. jorgenson c., caricchi l., bouvier a.-s., giordano g., weber g., marxer f. (2020) consequences of co2-magma interaction for explosive volcanism at colli albani (italy). in agu fall meeting abstracts, v038-0002. 2020. kahl m., viccaro m., ubide t., morgan d., dingwell d.b. (2017) a branched magma feeder system during the 1669 eruption of mt. etna: evidence from a time -integrated study of zoned olivine phenocryst populations. journal of petrology, 58, 443-472. karner d.b., marra f., renne p.r. (2001) the history of the monti sabatini and alban hills volcanoes: groundwork for assessing volcanic-tectonic hazards for rome. journal of volcanology and geothermal research, 107, 185-219. keller j. (1980) the island of vulcano. rendiconti della società italiana di mineralogia e petrologia, 36, 369 -414. keller j., ryan w.b.f., ninkovich d., altherr r. (1978) explosive volcanic activity in the mediterranean over the past 200,000 yr as recorded in deep-sea sediments. geologica society of america bulletin, 89, 591-604. kelly t.j., carey s., pistolesi m., rosi m., croff-bell k.l.c., roman c., marani m. (2014) exploration of the 1891 foerstner submarine vent site (pantelleria, italy): insights into the formation of basaltic balloons. bulletin of volcanology, 76, 844. doi: doi.org/10.1007/s00445-014-0844-4 la volpe l., principe c. (1989a) stratigrafia e storia eruttiva del monte vulture revisione ed aggiornamenti. bollettino gruppo nazionale per la vulcanologia 5, 889-902. laberge r.d., giordano g., cas r.a.f., ailleres l. (2006) syn-depositional substrate deformation produced by the shear force of a pyroclastic density current: an example from the pleistocene ignimbrite at monte cimino, northern lazio, italia. journal of volcanology and geothermal research, 158, 307320. laberge r.d., porreca m., mattei m., giordano g., cas r.a.f. (2008) meandering flow of a pyroclastic density current documented by the anisotropy of magnetic susceptibility (ams) in the quartz latite ignimbrite of the pleistocene monte cimino volcanic centre (central italy). tectonophysics. doi: 10.1016/j.tecto.2008.09.009 lane c.s., andric m., cullen v.l., blockley s.p.e. (2011) the occurrence of distal icelandic and italian tephra in the lateglacial of lake bled, slovenia. quaternary science reviews, 30, 1013-1018. lane c.s., brauer a., martín-puertas c., blockley s.p.e., smith v.c., tomlinson e.l. (2015) the late quaternary tephrostratigraphy of annually laminated sediments from meerfelder maar, germany. quaternary science reviews, 122, 192-206. lardini d., nappi g. (1987) i cicli eruttivi del complesso vulcanico cimino. rendiconti della società italiana di mineralogia e petrologia, 42, 141-153. laurenzi m.a., villa i.m. (1987) 40ar/39ar chronostratigraphy of vico ignimbrites. periodico di mineralogia, 56, 285-293. laurenzi m., braschi e., casalini m., conticelli s. (2015) new 40ar-39ar dating and revision of the geochro 274 branca s. et al. https://doi.org/10.1007/s00445-010-0379-2 nology of the monte amiata volcano, central italy. italian journal of geosciences, 134, 255-265. le maitre r.l., streckeisen a., zanettin b. (2002) igneous rocks. a classification and glossary of terms. recommendations of the iugs subcomission on the systematics of igneous rocks. leicher n., giaccio b., zanchetta g., wagner b., francke a., palladino d.m., sulpizio r., albert p.g., tomlinson e.l. (2019) central mediterranean explosive volcanism and tephrochronology during the last 630 ka based on the sediment record from lake ohrid. quaternary science reviews, 226, 106021. leicher n., giaccio b., zanchetta g., sulpizio r., albert p.g., tomlinson e. l., lagos m., francke a., wagner b. (2021) lake ohrid’s tephrochronological dataset reveals 1.36 ma of mediterranean explosive volcanic activity. scientific data, 8, 231. doi: 10.1038/s41597-021-01013-7 leicher n., giaccio b., pereira a., nomade s., monaco l., mannella g., galli p., peronance e., palladino d.m., sottili g., zanchetta g., wagner b. (2023) central mediterranean tephrochronology between 313 and 366 ka: new insights from the fucino palaeolake sediment succession. boreas. doi: 10.1111/bor.12610 lentini f. (1982) the geology of the mt. etna basement. memorie della società geologica italiana, 23, 7-25. leocat e. (2011) histoire eruptive des volcans du secteur occidental des iles eoliennes (sud de la mer tyrrhenienne, italie). phd thesis, university of paris 11, orsay. liotta d. (1996) analisi del settore centro-meridionale del bacino pliocenico di radicofani (toscana meridionale bollettino della società geologica italiana, 115, 115-143. lirer l., rolandi g., rubin m. (1991) 14c age of the “museum breccia” (campi flegrei) and its relevance for the origin of the campanian ignimbrite. journal of volcanology and geothermal research 48, 223-227. lirer l., petrosino p., alberico i. (2010) hazard and risk assessment in a complex multi-source volcanic area: the example of the campania region, italy. bulletin of volcanology, 72, 411-429. doi: 10.1007/s00445-009-0334-2 lisiecki l.e., raymo m.e. (2005) a pliocenepleistocene stack of 57 globally distributed benthic δ18o records. paleoceanography, 20, pa1003. doi: 10.1029/2004pa001071 locardi e. (1965) tipi di ignimbriti di magmi mediterranei; le ignimbriti del vulcano di vico. atti della società toscana di scienze naturali, 72, 55-174. lombardi g., nicoletti m., petrucciani c. (1974) età delle vulcaniti acide dei complessi tolfetano, cerite e manziate (lazio nordoccidentale). periodico mineralogia, 43, 181-204. loreto m.f., zitellini n., ranero c., palmiotto c., manel p. (2020) extensional tectonics during the tyrrhenian back-arc basin formation and a new morphotectonic map. basin research, 33, 138-158. lucchi f., keller j., tranne c.a. (2013a) regional stratigraphic correlations across the aeolian archipelago (southern italy). geological society, london, memoirs, 37, 55-81 lucchi f., gertisser r., keller j., forni f., de astis g., tranne c.a. (2013b) eruptive history and magmatic evolution of the island of salina (central aeolian archipelago). geological society, london, memoirs, 37, 155-211. lucchi f., tranne c.a., peccerillo a., keller j., rossi p.l. (2013c) geological history of the panarea volcanic group (eastern aeolian archipelago). geological society, london, memoirs, 37, 349-393. lucchi f., peccerillo a., tranne c.a., rossi p.l., frezzotti m.l., donati c. (2013d) volcanism, calderas, and magmas of the alicudi composite volcano (western aeolian archipelago). geological society, london, memoirs, 37, 83-111. lucchi f., santo a., tranne c.a., peccerillo a., keller j. (2013e) volcanism, magmatism, volcanotectonics and sea-level fluctuations in the geological history of filicudi (western aeolian archipelago). geological society, london, memoirs, 37, 113-153. lucchi f., francalanci l., de astis g., tranne c.a., braschi e., klaver m. (2018) geological evidence for recurrent collapse-driven phreatomagmatic pyroclastic density currents in the holocene activity of stromboli volcano, italy. journal of volcanology and geothermal research. doi: 10.1016/j.jvolgeores.2018.10.024 luhr j.f., giannetti b. (1987) the brown leucitic tuff of roccamonfina volcano (roman region, italy). contribution to mineralogy and petrology, 95, 420436. lupton j., de ronde c., sprovieri m., baker e.t., bruno p.p., italiano f., walker s., faure k., leybourne m., britten k., greene r. (2011) active hydrothermal discharge on the submarine aeolian arc. journal of geophysical research b: solid earth, 116, b02102. lustrino m., duggen s., rosenberg c.l. (2011) the central-western mediterranean: anomalous igneous activity in an anomalous collisional tectonic setting. earth-science reviews, 104(1-3), 1-40. macedonio g., costa a., folch a. (2008) ash fallout scenarios at vesuvius: numerical simulations and implications for hazard assessment. journal of volcanology and geothermal research, 178, 366377. macedonio g., costa a., scollo s., neri a. (2016) effects of eruption source parameter variation and meteorological dataset on tephra fallout hazard assessment: example from vesuvius (italy). journal of applied volcanology, 5, 5. doi: 10.1186/s13617-016-0045-2 mahood g.a., hildreth w. (1986) geology of the peralkaline volcano at pantelleria, strait of sicily. bulletin of volcanology, 48, 143-172. malaguti a.b., rosi m., pistolesi m., speranza f., menzies m. (2022) the contribution of palaeomagnetism, tephrochronology and radiocarbon dating to refine the last 1100 years of eruptive activity at vulcano (italy). bulletin of volcanology, 84, 12 malaguti a.b., branca s., speranza f., coltelli m., del carlo p., renzulli a. (2023) age of the valle del bove formation and chronology of the post-collapse 275 the italian quaternary volcanism https://doi.org/10.1111/bor.12610 https://doi.org/10.1007/s00445-009-0334-2 https://doi.org/10.1016/j.jvolgeores.2018.10.024 flank eruptions, etna volcano (italy). journal of volcanology and geothermal research, 434, 107752. malinverno a., ryan w.b.f. (1986) extension in the tyrrhenian sea and shortening in the apennines as result of arc migration driven by sinking of the lithosphere. tectonics, 5, 227-245. mandarano m., paonita a, martelli m., viccaro m., nicotra e., millar i.l. (2016) revealing magma degassing below closed-conduit active volcanoes: geochemical features of volcanic rocks versus fumarolic fluids at vulcano (aeolian islands, italy). lithos, 248-251, 272-287. mangiacapra a., moretti r., rutherford m., civetta l., orsi g., papale p. (2008) the deep magmatic system of the campi flegrei caldera (italy). geophysical research letters, 35, l21304. doi: 10.1029/2008gl035550 marani m.p., gamberi f. (2004) distribution and nature of submarine volcanic landforms in the tyrrhenian sea: the arc vs the back-arc. memorie descrittive della carta geologica italiana, lxiv, 109-126. marra f., karner d.b. (2005) the albano maar (alban hills volcanic district, italy): active or dormant volcano? il quaternario, 18 (2), 173-185. marra f., freda c., scarlato p., taddeucci j., karner d.b., renne p.r., gaeta m., palladino d.m., trigila r., cavarretta g. (2003) 40ar/39ar geochronology of the recent phase of activity of the alban hills volcanic district (rome, italy): implications for seismic and volcanic hazards. bulletin of volcanology, 65, 227-247. marra f., taddeucci j., freda c., marzocchi w., scarlato p. (2004) recurrence of volcanic activity along the roman comagmatic province (tyrrhenian margin of italy) and its tectonic significance. tectonics, 23, tc4013. marra f., karner d.b., freda c., gaeta m., renne p.r. (2009) large mafic eruptions at the alban hills volcanic district (central italy): chronostratigraphy, petrography and eruptive behavior. journal of volcanology and geothermal research,179, 217-232. marra f., deocampo d., jackson m. d., ventura g. (2011) the alban hills and monti sabatini volcanic products used in ancient roman masonry (italy): an integrated stratigraphic, archaeological, environmental and geochemical approach. earth-science reviews, 108(3-4), 115-136. marra f., sottili g., gaeta m., giaccio b., jicha b., masotta m., palladino d.m., deocampo d.m. (2014) major explosive activity in the sabatini volcanic district (central italy) over the 800-390 ka interval: geochronological geochemical overview and tephrostratigraphic implications. quaternary science reviews, 94, 74-101. marra f., gaeta m., giaccio b., jicha b., palladino d.m., polcari m., sottili g., taddeucci j., florindo f., stramondo s. (2016) assessing the volcanic hazard for rome: 40ar/39ar and in-sar constraints on the most recent eruptive activity and present-day uplift at colli albani volcanic district. geophysical research letters, 43, 6898-6906. marra f., costantini l., di buduo g.m., florindo f., jicha b., monaco l., palladino d.m., sottili g. (2019) combined glacio-eustatic forcing and volcanotectonic uplift: geomorphological and geochronological constraints on the tiber river terraces in the eastern vulsini volcanic district (central italy). global and planetary changes, 182, 103009. marra f., jicha b., palladino d.m., gaeta m., costantini l., di buduo g.m. (2020a) 40ar-39ar single crystal dates from pyroclastic deposits provide a detailed record of the 590-240 ka eruptive period at the vulsini volcanic district (central italy). journal of volcanology and geothermal research, 398, 106904. marra f., castellano c., cucci l., florindo f., gaeta m., jicha b., palladino d.m., sottili g., tertulliani a., tolomei c. (2020b) monti sabatini and colli albani: the dormant twin volcanoes at the gates of rome. scientific reports, 10, 8666. doi: 10.1038/s41598-02-65394-2 marra f., cardello g.l., gaeta m., jicha b.r., montone p., niespolo e.m., nomade s., palladino d.m., pereira a., de luca g., florindo f., frepoli a., renne p.r., sottili g. (2021) the volsci volcanic field (central italy): eruptive history, magma system and implications on continental subduction processes. international journal of earth sciences, 110, 689-718. marroni m., moratti g., costantini a., conticelli s., benvenuti m.g., pandolfi l., bonini m., cornamusini g., laurenzi m.a. (2015) geology of the monte amiata region, southern tuscany, central italy. italian journal of geosciences, 134(2), 171-199. marzocchi w., sandri l., selva j. (2010) bet_vh: a probabilistic tool for long-term volcanic hazard assessment. bulletin of volcanology, 72, 705-716. mascle g. h., tricart p., torelli l., bouillin j.p., rolfo f., lapierre h., monié p., depardon s., mascle j., peis d. (2001) evolution of the sardinia channel (western mediterranean): new constraints from a diving survey on cornacya seamount off se sardinia. marine geology, 179, 179-201. masotta m., gaeta m., gozzi f., marra f., palladino d.m., sottili g. (2010) h2oand temperaturezoning in magma chambers: the example of the tufo giallo della via tiberina eruptions (sabatini volcanic district, central italy). lithos, 118(1-2), 119 -130. massaro s., stocchi m., martínez montesinos b., sandri l., selva j., sulpizio r., giaccio b., moscatelli m., peronace e., nocentini m., isaia r., titos luzón m., dellino p., naso g., costa a. (2023) assessing long-term tephra fallout hazard in southern italy from neapolitan volcanoes. natural hazards and earth system sciences discussions, 1-35. mattei m., conticelli s., giordano g. (2010) the tyrrhenian margin geological setting: from the apennine orogeny to the k-rich volcanism the colli albani volcano, funiciello r., giordano g. (eds.), special publication of iavcei, 3, the geological society, london, 7-27. melluso l., morra v., di girolamo p. (1996) the m.te vulture volcanic complex (italy): evidence for distinct parental magmas and for residual melts with melilite. mineralogy and petrology, 56, 225-250. 276 branca s. et al. mercalli g., silvestri o. (1891) le eruzioni dell’isola di vulcano, incominciate il 3 agosto 1888 e terminate il 22 marzo 1890. annali dell’ufficio centrale di meteorologia e geodinamica, 10 (4), 1-213. meschiari s., albert p.g., lucchi f., sulpizio r., smith v.c., kearne r., tranne c.a. (2020) frequent activity on vulcano (italy) spanning the last 80 ky: new insights from the chemo-stratigraphy of the brown tuffs. journal of volcanology and geothermal research, 406. métrich n., santacroce r., savelli c. (1988) ventotene, a potassic quaternary volcano in central tyrrhenian sea. rendiconti società italiana mineralogia petrologia, 43, 1195-1213. métrich n., allard p., spilliaert n., andronico d., burton m. (2004) 2001 flank eruption of the alkaliand volatile-rich primitive basalt responsible for mount etna’s evolution in the last three decades. earth and planetary science letters, 228, 1-17. métrich n., bertagnini a., pistolesi m. (2021) paroxysms at stromboli volcano (italy): source, genesis and dynamics. frontiers in earth sciences. doi: 10.3389/feart.2021.593339 milano g., passaro s., sprovieri m. (2012) present-day knowledge on the palinuro seamount (southeastern tyrrhenian sea). bollettino di geofisica teorica ed applicata, 53, 403-416. milia a., giordano f., nardi g. (1998) stratigraphic and structural evolution of naples harbour over the last 12 ka. giornale di geologia, 60, 41-52. mixon e.e., jicha b.r., tootell d., singer b.s. (2022) optimizing 40ar/39ar analyses using an isotopx ngx-600 mass spectrometer. chemical geology, 593, 120753. doi: 10.1016/j.chemgeo.2022.120753 monaco l. (2022) tempo and dynamics of the perityrrhenian quaternary explosive volcanism inferred from distal archives. phd dissertation, xxxiv doctorate cycle, ph.d. school “vito volterra”, earthsciences curriculum, sapienza-university of rome, pp. 267. monaco l., palladino d.m., gaeta m., marra f., sottili g., leicher n., mannella g., nomade s., pereira a., regattieri e., wagner b., zanchetta g., albert p.g., arienzo i., d’antonio m., petrosino p., manning c.j., giaccio b. (2021) mediterranean tephrostratigraphy and peri-tyrrhenian explosive activity revaluated in light of the 430-365 ka record from fucino basin (central italy). earth-science reviews, 220, 103706. monaco l., leicher n., palladino d.m., arienzo i., marra f., petrelli m., nomade s., pereira a., sottili g., conticelli s., d’antonio m., fabbrizio a., jicha b.r., mannella g., petrosino p., regattieri e., tzedakis p.c., wagner b., zanchetta g., giaccio b. (2022a) the fucino 250-170 ka tephra record: new insights on peri-tyrrhenian explosive volcanism, central mediterranean tephrochronology, and timing of the mis 8-6 climate variability. quaternary science reviews, 296, 107797. monaco l., palladino d.m., albert p.g., arienzo i., conticelli s., di vito m., fabbrizio a., d'antonio m., isaia r., manning c.j., nomade s., pereira a., petrosino p., sottili g., sulpizio r., zanchetta g., giaccio b. (2022b) linking the mediterranean mis 5 tephra markers to campi flegrei (southern italy) 109-92 ka explosive activity and refining the chronology of mis 5c-d millennial-scale climate variability. global and planetary change, 211, 103785. montesinos b.m., luzón m.t., sandri l., rudyy o., cheptsov a., macedonio g., folch a., barsotti s., selva j., costa a. (2022) on the feasibility and usefulness of high-performance computing in probabilistic volcanic hazard assessment: an application to tephra hazard from campi flegrei. frontiers in earth science, 10:941789. doi: 10.3389/feart.2022.941789 nappi g. (1969) genesi ed evoluzione della caldera di latera: bollettino del servizio geologico italiano, 90, 61-81. nappi g., marini a. (1986) i cicli eruttivi dei vulsini orientali nell’ambito della vulcanotettonica del complesso. memorie della società geologica italiana, 35, 679-687. nappi g., renzulli a., santi p. (1991) evidence of incremental growth in the vulsinian calderas (central italy). in: verma-surendra p. (ed.), calderas: genesis, structure and unrest. journal of volcanology and geothermal research,47, 13-31. nappi g., capaccioni b., mattioli m., mancini e., valentini l. (1994) plinian fall deposits from vulsini volcanic district (central italy). bulletin of volcanology, 56, 502-515. nappi g., renzulli a., santi p., gillot y. (1995) geological evolution and geochronology of the vulsini volcanic district (central italy). bollettino della società geologica italiana, 114, 599-613. nappi g., chiocchini u., bonomo r., madonna s., mattioli m., ricci v., vita l. (2022) note illustrative della carta geologica d’italia alla scala 1:50.000, f. 345 viterbo. ispra servizio geologico d’italia, roma, pp. 273. doi: 10.15161/oar.it/75774 nazzaro a. (1997) il vesuvio: storia eruttiva e teorie vulcanologiche. liguori ed., napoli, italy, pp. 374. neri m., rivalta e., maccaferri f., acocella v., cirrincione r. (2018) etnean and hyblean volcanism shifted away from the malta escarpment by crustal stresses. earth and planetary science letters, 486, 1522. nicoletti m. (1969) datazioni ar-k di alcune vulcaniti delle regioni vulcaniche cimina e vicana. periodico di mineralogia, 38, 1-20. nicoletti m., petrucciani c., piro m., trigila r. (1981) nuove datazioni vulsine per uno schema di evoluzione dell'attività vulcanica. nota ii il quadrante sud-occidentale. periodico di mineralogia, 50, 141169. nicotra e., viccaro m. (2012) unusual magma storage conditions at mt. etna (southern italy) as evidenced by plagioclase megacryst-bearing lavas: implications for the plumbing system geometry and summit caldera collapse. bulletin of volcanology, 74, 795815. nicotra e., viccaro m., de rosa r., sapienza m. (2014) volcanological evolution of the rivi-capo volcanic complex at salina, aeolian islands: magma storage processes and ascent dynamics. bulletin of volcan 277 the italian quaternary volcanism https://doi.org/10.3389/feart.2021.593339 ology, 75, 840. nicotra e., giuffrida m., viccaro m., donato p., d'oriano c., paonita a., de rosa r. (2018) timescales of pre-eruptive magmatic processes at vulcano (aeolian islands, italy) during the last 1000 years. lithos, 316-317, 347-365 nicotra e., minniti m., donato p., de rosa r. (2020) insights into the eruptive dynamics of small caldera-forming eruptions: the case study of the welded scoriae of vulcano (aeolian islands, italy). frontiers in earth science, 8, 223. doi: 10.3389/feart.2020.00223 orlando a., conticelli s., manetti p., vaggelli g. (1994) the basement of northern vulsinian volcanic district as inferred from the study of crustal xenoliths from the torre alfina lavas, viterbo, central italy. memorie della società geologica italiana, 48, 681-688. orsi g., gallo g., zanchi a. (1991) simple-shearing block resurgence in caldera depressions. a model from pantelleria and ischia. journal of volcanology and geothermal research, 47, 1-11. doi: 10.1016/0377-0273(91)90097 orsi g., d'antonio m., de vita s., gallo g. (1992) the neapolitan yellow tuff, a large-magnitude trachytic phreatoplinian eruption: eruptive dynamics, magma withdrawal and caldera collapse. journal of volcanology and geothermal research, 53, 275-287. orsi g., civetta l., d'antonio m., di girolamo p., piochi m. (1995) step-filling and development of a threelayers magma chamber: the neapolitan yellow tuff case history. journal of volcanology and geothermal research, 67, 291-312. orsi g., de vita s., di vito m. (1996) the restless, resurgent campi flegrei nested caldera (italy): constraints on its evolution and configuration. journal of volcanology and geothermal research, 74, 179214. orsi g., civetta l., del gaudio c., de vita s., di vito, isaia r.m., petrazzuoli s., ricciardi g., ricco c. (1999) short term ground deformations and seismicity in the nested campi flegrei caldera italy : an example of active block resurgence in a densely populated area. journal of volcanology and geothermal research, 91, 415-451. ort m., orsi g., pappalardo l., fisher r.v. (2003) anisotropy of magnetic susceptibility studies of depositional processes in the campanian ignimbrite, italy. bulletin of volcanology, 65, 55-72. pabst s., wörner g., civetta l., tesoro r. (2008) magma chamber evolution prior to the campanian ignimbrite and neapolitan yellow tuff eruptions (campi flegrei, italy). bulletin of volcanology, 70,961-976. doi: 10.1007/s00445-007-0180-z palano m., viccaro m., zuccarello f., gresta s. (2017) magma transport and storage at mt. etna (italy): a review of geodetic and petrological data for the 2002-03, 2004 and 2006 eruptions. journal of volcanology and geothermal research, 347, 149-164. palladino d.m., agosta e. (1997) pumice fall deposits of the western vulsini volcanoes (central italy). journal of volcanology and geothermal research, 78, 77-102. palladino d.m., giordano g. (2019) on the mobility of pyroclastic currents in light of deposit thickness and clast size trends. journal of volcanology and geothermal research, 384, 64-74. palladino d.m., pettini m. (2020) sourcevs topographic-forcing in pyroclastic currents: the case of the orvieto-bagnoregio ignimbrite, vulsini, central italy. periodico di mineralogia, 89, 217-229. palladino d.m., simei s. (2005) eruptive dynamics and caldera-collapse during the onano eruption, vulsini, italy. bulletin of volcanology, 67, 423-440. palladino d.m., valentine g.a. (1995) coarse-tail vertical and lateral grading in pyroclastic flow deposits of the latera volcanic complex (vulsini, central italy): origin and implications for flow dynamics. journal of volcanology and geothermal research,69, 343-364. palladino d.m., gaeta m., marra f. (2001) a large kfoiditic hydromagmatic eruption from the early activity of the alban hills volcanic district, italy. bulletin of volcanology, 63, 345-359. palladino d.m., simei s., sottili g., trigila r. (2010) integrated approach for the reconstruction of stratigraphy and geology of quaternary volcanic terrains: an application to the vulsini volcanoes (central italy). in: groppelli g., viereck l. (eds.), "stratigraphy and geology in volcanic areas", geological society of america, special papers, 464, 66 -84. palladino d.m., gaeta m., giaccio b., sottili g. (2014) on the anatomy of magma chamber and caldera collapse: the example of trachy-phonolitic explosive eruptions of the roman province (central italy). journal of volcanology and geothermal research, 281, 12-26. paone a. (2013) petrogenesis of trachyte and rhyolite magmas on ponza island (italy) and its relationship to the campanian magmatism. journal of volcanology and geothermal research, 267, 15-29. paonita a., federico c., bonfanti p., capasso g., inguaggiato s., italiano f., madonia p., pecoraino g., sortino f. (2013) the episodic and abrupt geochemical changes at la fossa fumaroles (vulcano island, italy) and related constraints on the dynamics, structure, and compositions of the magmatic system. geochimica et cosmochimica acta, 120, 158-178. pappalardo l., civetta l., d’antonio m., deino a., di vito m.a., orsi g., carandente a., de vita s., isaia r., piochi m. (1999) chemical and sr isotopical evolution of the phlegraean magmatic system before the campanian ignimbrite (37 ka) and the neapolitan yellow tuff (12 ka) eruptions. journal of volcanology and geothermal research, 91, 141166. pappalardo l., civetta l., de vita s., di vito m.a., orsi g., carandente a., fisher r.v. (2002) timing of magma extraction during the campanian ignimbrite eruption (campi flegrei caldera). journal of volcanology and geothermal research, 114, 479-497. pasquaré g., chiesa s., vezzoli l., zanchi a. (1983) evoluzione paleogeografica e strutturale di parte della toscana meridionale a partire dal miocene superiore. memorie della società geologica italiana. 25, 145-157. 278 branca s. et al. pasquarè g., serri g., vezzoli l. (1985) carta geologica dell’area della media valle latina. scala 1:50 000. progetto finalizzato geodinamica. sottoprogetto: sorveglianza dei vulcani e rischio vulcanico. in: carte tematiche sul vulcanismo recente. istituto di geologia, university of milan, italy. paterne m., guichard f., duplessy j.c., siani g., sulpizio r., labeyrie j. (2008) a 90,000-200,000 yrs marine tephra record of italian volcanic activity in the central mediterranean sea. journal of volcanology and geothermal research, 177, 187-196. peccerillo a. (2005) plio-quaternary volcanism in italy. springer-verlag, berlin heidelberg, pp. 365. peccerillo a. (2017) cenozoic volcanism in the tyrrhenian sea region. iavcei, advances in volcanology, springer (ed.), barcelona, spain, pp. 399. peccerillo a., conticelli s., manetti p. (1987) petrological characteristics and the genesis of the recent magmatism of south tuscany and north latium. periodico di mineralogia, 56, 157-173. peccerillo a., de astis g., faraone d., forni f., frezzotti m.l. (2013) compositional variations of magmas in the aeolian arc: implications for petrogenesis and geodynamics geological society of london memoirs, 37, 1, 491-510. doi:10.1144/m37.15 pereira a., monaco l., marra f., nomade s., gaeta m., leicher n., palladino d.m., sottili g., guillou h., scao v., giaccio b. (2020) tephrochronology of the central mediterranean mis 11c interglacial (∼425-395 ka): new constraints from the vico volcano and tiber delta, central italy. quaternary sciences reviews, 243, 106470. perini g. (1997) evoluzione magmatologica del vulcano di vico. ph.d. thesis, università degli studi di firenze. perini g., conticelli s. (2002) crystallization conditions of leucite-bearing magmas and their implications on the magmatological evolution of ultrapotassic magmas: the vico volcano, central italy. mineralogy and petrology, 74, 253-276. perini g., conticelli s., francalanci l. (1997) inferences on the volcanologcal history of the vico volcano, roman magmatic province, central italy: stratigraphic, petrographic and geochemical data. mineralogica and petrographica acta, 40: 67-93. perini g., conticelli s., francalanci l., davidson j p. (2000) the relationship between potassic and calc -alkaline post-orogenic magmatism at vico volcano, central italy. journal of volcanology and geothermal research, 95, 247-272. perini g., tepley f.j. iii, davidson j.p., conticelli s. (2003) the origin of k-feldspar megacrysts hosted in alkaline potassic rocks: track for low scale mantle heterogeneity. lithos, 66, 223-240 perini g., francalanci l., davidson j.p., conticelli s. (2004) evolution and genesis of magmas from vico volcano, central italy: multiple differentiation pathways and variable parental magmas. journal of petrology, 45(1), 139-182. pescatore t., rolandi g. (1981) preliminary observations on stratigraphy of volcanoclastic deposits of the sw sector of campi flegrei. bollettino della società geologica italiana, 100, 233-254. petrosino p., jicha b.r., mazzeo f.c., russo ermolli e. (2014) a high-resolution tephrochronological record of mis 14-12 in the southern apennines (acerno basin, italy). journal of volcanology and geothermal research, 274, 34-50. petrosino p., jicha b.r., mazzeo f.c., ciaranfi n., girone a., maiorano p., marino m. (2015) the montalbano jonico marine succession: an archive for distal tephra layers at the early-middle pleistocene boundary in southern italy. quaternary international, 383, 89-103. doi: 10.1016/j.quaint.2014.10.049 petrosino p., arienzo i., mazzeo f.c., natale j., petrelli m., milia a., perugini d., d’antonio m. (2019) the san gregorio magno lacustrine basin (campania, southern italy): improved characterization of the tephrostratigraphic markers based on trace elements and isotopic data. j. quat. sci. 34, 393-404. piochi m., bruno p.p., de astis g. (2005) relative roles of rifting tectonics and magma uprising processes: inferences from geophysical, structural and geochemical data of the neapolitan volcanic region (southern italy). geochemistry geophysics and geosystems, 6, q07005. doi: 10.1029/2004gc000885 pistolesi m., rosi m., malaguti a.b., lucchi f., tranne c.a., speranza f., albert p.g., smith v.c., di roberto a., billotta e. (2021) chrono-stratigraphy of the youngest (last 1500 years) rhyolitic eruptions of lipari (aeolian islands, southern italy) and implications for distal tephra correlations. journal of volcanology and geothermal research, 420, 107397 poli s., chiesa s., gillot p.y., gregnanin a., guichard f., stella r. (1987) major and trace element variation versus time in the volcanic products of ischia (gulf of neaples), evidence of successive magmatic cycles. contributions to mineralogy and petrology, 95, 322-335. poli s., chiesa s., gillot p.y., guichard f., vezzoli l. (1989) time dimension in the geochemical approach and hazard estimates of a vulcanic area: the isle of ischia case (italy). journal of volcanology and geothermal research, 36, 327-335. principe c., giannandrea p. (2006) storia evolutiva del monte vulture. in c. principe ed. la geologia del monte vulture, 49-54. principe c., la volpe l. (1989) guida all’escursione sul monte vulture del 18-19 ottobre 1989. convegno scientifico “genesi e aspetti geodinamici del vulcanismo potassico e ultrapotassico: stato dell’arte e prospettive di ricerca”. bari, 17-18 ottobre 1989, 133. principe c. tanguy j.c. arrighi s., paiotti a., le goff. m., zoppi u. (2004) chronology of vesuvius’ activity from a.d. 79 to 1631 based on archeomagnetism of lavas and historical sources. bulletin of volcanology, 66, 703-724. putignano m.l., schiattarella m. (2010) geomorfologia strutturale e domini di frattura dei fondali marini pericostieri dell’isola di procida (campi flegrei insulari, italia meridionale). alpine and mediterranean quaternary, 23(2), 229-242. putignano m.l., orrù p. e., schiattarella m. (2014) ho 279 the italian quaternary volcanism locene coastline evolution of procida island, bay of naples, italy. quaternary international, 332, 115125. puxeddu m. (1971) studio chimico-petrografico delle vulcaniti del m. cimino (viterbo). atti della società toscana di scienze naturali, memorie, serie a, 78, 329-394. radicati di brozolo f., di girolamo p., turi b., oddone m. (1988) 40ar-39ar and k-ar dating of k-rich rocks from the roccamonfina volcano, roman comagmatic region, italy. geochmica et cosmochimica acta, 52, 1435-1441. ripepe m., lacanna g., pistolesi m., silengo m. c., aiuppa a., laiolo m., massimetti f., innocenti l., della schiava m., bitetto m., la monica f. p., nishimura t., rosi m., mangione d., ricciardi a., genco r., coppola d., marchetti e., delle donne d. (2021) ground deformation reveals the scaleinvariant conduit dynamics driving explosive basaltic eruptions. nature communications, 12, 1683. doi: 10.1038/s41467-021-21722-2 risica g., speranza f., giordano g., de astis g., lucchi f. (2019) palaeomagnetic dating of the neostromboli succession. journal of volcanology and geothermal research, 371. doi: 10.1016/j.jvolgeores.2018.12.009 rolandi g., bellucci f., cortini m. (2004) a new model for the formation of the somma caldera. mineralogy and petrology, 80, 27-44. romagnoli c. (2013) characteristics and morphological evolution of the aeolian volcanoes from the study of submarine portions. geological society, london, memoirs, 37, 13-26. romagnoli c., kokelaar p., casalbore d., chiocci f.l. (2009) lateral collapses and active sedimentary processes on the northwestern flank of stromboli volcano. marine geology, 265, 101-119. romagnoli c., casalbore d., bortoluzzi g., bosman a., chiocci f.l., d’oriano f., gamberi f., ligi m., marani m. (2013) bathy-morphological setting of the aeolian islands. geological society, london, memoirs, 37, 27-36. romagnoli c., belvisi v., innangi s., di martino g., tonielli (2020) new insights on the evolution of the linosa volcano (sicily channel) from the study of its submarine portions. marine geology, 419, 106060. romano r., sturiale c., lentini f. (1979) carta geologica del monte etna, consiglio nazionale delle ricerche progetto finalizzato geodinamica, 1:50,000-scale, catania, sicily. rosatelli g., stoppa f., jones a.p. (2000) intrusive calcitecarbonatite occurrence from mt. vulture volcano, southern italy. mineralogical magazine, 64. rosi m., santacroce r. (1983) the a.d. 472 “pollena” eruption: volcanological and petrological data for this poorly-known, plinian-type event at vesuvius. journal of volcanology and geothermal research, 17 (1-4), 249-271 rosi m., sbrana a. (eds) (1987) phlegraean fields. quaderni de "la ricerca scientifica" cnr, rome, 114, 1-175 rosi m., principe c., vecci r. (1993) the 1631 vesuvius eruption. a reconstruction based on historical and stratigraphical data. journal of volcanology and geothermal research, 58(1-4), 151-182. doi: 10.1016/0377-0273(93)90106-2 rosi m., vezzoli l., aleotti p., de censi m. (1996) interaction between caldera collapse and eruptive dynamics during the campanian ignimbrite eruption, phlegraean fields, italy. bulletin of volcanology, 57, 541-554. rosi m., vezzoli l., castelmenzano a., greco g. (1999) plinian pomice fall deposit of the campanian ignimbrite eruption (phlegrean fields italy). journal of volcanology and geothermal research, 91,179198. rosi m., pistolesi m., bertagnini a., landi p., pompilio m., di roberto a. (2013) stromboli volcano, aeolian islands (italy): present eruptive activity and hazards. geological society, london, memoirs, 37, 473-490. rossi p.l., tranne c. a., calanchi n., lant e. (1996) geology, stratigraphy and volcanological evolution of the island of linosa (sicily channel). acta vulcanologica, 8, 73-90. rotolo s.g., castorina f., cellura d., pompilio m. (2006) petrology and geochemistry of submarine volcanism in the sicily channel rift. journal of geology, 114 (3), 355-365. rotolo s.g., la felice s., mangalaviti a., landi p. (2007) geology and petrochemistry of the recent (<25 ka) silicic volcanism at pantelleria island. bollettino della società geologica italiana, 126, 191-208. rotolo s.g., scaillet s., la felice s., vita-scaillet g. (2013) a revision of the structure and stratigraphy of pre-green tuff ignimbrites at pantelleria (strait of sicily). journal of volcanology and geothermal research, 250, 61-74. rotolo s.g., scaillet s., speranza f, white j.c., williams r., jordan n.j. (2021) volcanological evolution of pantelleria island (strait of sicily) peralkaline volcano: a review. comptes rendus geosciences, 353, 111-132. rouchon v., gillot p.y., quidelleur x., chiesa s., floris b. (2008) temporal evolution of the roccamonfina volcanic complex (pleistocene), central italy. journal of volcanology and geothermal research, 177, 500-514. russo ermolli e., aucelli p.p.c., di rollo a., mattei m., petrosino p., porreca m., rosskopf c.m. (2010) an integrated stratigraphical approach to the middle pleistocene succession of the sessano basin (molise, italy). quaternary international, 225, 114127. sandri l., jolly g., lindsay j., howe t., marzocchi w. (2012) combining long-and short-term probabilistic volcanic hazard assessment with cost-benefit analysis to support decision making in a volcanic crisis from the auckland volcanic field, new zealand. bulletin of volcanology, 74, 705-723. doi: 10.1007/s00445-011-0556-y sandri l., thouret j.-c., constantinescu r., biass s., tonini r. (2014) long-term multi-hazard assessment for el misti volcano (peru). bulletin of volcanology, 76, 771. doi: 10.1007/s00445-013-0771-9 sandri l., costa a., selva j., tonini r., macedonio g., 280 branca s. et al. https://doi.org/10.1038/s41467-021-21722-2 https://doi.org/10.1038/s41467-021-21722-2 folch a., sulpizio r. (2016) beyond eruptive scenarios: assessing tephra fallout hazard from neapolitan volcanoes. scientific reports, 6, 2427124313. doi: 10.1038/srep24271 santacroce r. ed. (1987) somma vesuvius. cnr, quadaderni della ricerca scientifica, 114 (8), pp. 220. santacroce r., cioni r., marianelli p., sbrana a., sulpizio r., zanchetta g., donahue d.j., joron j. l. (2008) age and whole rock-glass compositions of proximal pyroclastics from the major explosive eruptions of somma-vesuvius: a review as a tool for distal tephrostratigraphy. journal of volcanology and geothermal research, 177, 1-18. doi: 10.1016/j.jvolgeores.2008.06.009 sartori r. (2003) the tyrrhenian back-arc basin and subduction of the ionian lithosphere. episodes, 26 (3), 217-221. doi: 10.18814/epiiugs/2003/v26i3/011 savelli c. (1987) k/ar ages and chemical data of volcanism in the western pontine islands (tyrrhenian sea). bollettino della società geologica italiana, 106, 356-546. savelli c. (1988) late oligocene to recent episodes of magmatism in and around the tyrrhenian sea: implications for the processes of opening in a young inter-arc basin of intra-orogenic (mediterranean) type. tectonophysics, 146, 163181. savelli c., ligi m. (2017) an updated reconstruction of basaltic crust emplacement in tyrrhenian sea, italy. scientific reports, 7, 18024. sbrana a., toccaceli r.m. (2011) isola di ischia. foglio 464, carta geologica della regione campania, scala 1:10.000. note illustrative. regione campania, assessorato difesa del suolo, pp. 216. sbrana a., marianelli p., pasquini g. (2018) volcanology of ischia (italy). journal of maps, 14 (2), 494503. doi: 10.1080/17445647.2018.1498811 sbrana a., cioni r., marianelli p., sulpizio r., andronico d., pasquini g. (2020) volcanic evolution of the somma-vesuvius complex (italy), journal of maps, 16(2), 137-147. doi: 10.1080/17445647.2019.1706653 scaillet s., vita-scaillet g., guillou h. (2008) oldest human footprints dated by ar/ar. earth and planetary science letters, 275, 320-325. scaillet s., rotolo s.g., la felice s., vita g. (2011) high resolution 40ar/39ar chronostratigraphy of the post-caldera (< 20 ka) volcanic activity at pantelleria, sicily strait. earth planetary science letters, 309, 280-290. scarpati c., cole p., perrotta a. (1993) the neapolitan yellow tuff-a large volume multiphase eruption from campi flegrei. southern italy. bulletin of volcanology, 55,343-356. scarpati c., perrotta a., lepore s., calvert a. (2013) eruptive history of neapolitan volcanoes: constraints from 40ar-39ar dating. geological magazine, 150, 03, 412-425. schiattarella m., beneduce p. (2006) caratteri geomorfologici, assetto strutturale ed evoluzione morfotettonica del monte vulture e delle aree contigue. in c. principe ed. la geologia del monte vulture, 1724. schiattarella m., beneduce p., di leo p., giano s.i., giannandrea p., principe c. (2005) assetto strutturale ed evoluzione morfotettonica quaternaria del vulcano del monte vulture (appennino lucano). bollettino della società geologica italiana, 124, 543‑562. schmincke h.u., behncke b., grasso m., raffi s. (1997) evolution of the northwestern iblean mountains, sicily: uplift, pliocene/pleistocene sea-level changes, paleoenvironment, and volcanism. geologische rundschau, 86, 637-669. scollo s., coltelli m., bonadonna c., del carlo p. (2013) tephra hazard assessment at mt. etna (italy). natural hazards and earth system sciences, 13, 3221-3233. scribano v. (1987a) deep-seated xenoliths in alkaline volcanic rocks from the hyblean plateau (sesicily). memorie della società geologica italiana, 38, 475-482. scribano v. (1987b) the ultramafic and mafic nodule suite in a tuff-breccia pipe from cozzo molino (hyblean plateau, sicily). rendiconti della società italiana di mineralogia e petrologia, 42, 203-217. scribano v., viccaro m., cristofolini r., ottolini l. (2009) metasomatic events recorded in ultramafic xenoliths from the hyblean area (southeastern sicily, italy). mineralogy and petrology, 95, 235-250. selva j., costa a., marzocchi w., sandri l. (2010) bet_vh: exploring the influence of natural uncertainties on long-term hazard from tephra fallout at campi flegrei (italy). bulletin of volcanology, 72, 717-733. selva j., costa a., sandri l., macedonio g., marzocchi w. (2014) probabilistic short-term volcanic hazard in phases of unrest: a case study for tephra fallout. jornal of geophysical reseach solid earth, 119, 8805-8826. doi: 10.1002/ 2014jb011252 selva j., costa a., de natale g., di vito m. a., isaia r., macedonio g. (2018) sensitivity test and ensemble hazard assessment for tephra fallout at campi flegrei, italy. journal of volcanology and geothermal research, 351, 1-28. doi: 10.1016/j.jvolgeores.2017. 11.024 selva j., acocella v., bisson m., caliro s., costa a., della seta m., de martino p., de vita s., federico c., giordano g., martino s., cardaci c. (2019) multiple natural hazards at volcanic islands: a review for the ischia volcano (italy). journal of applied volcanology, 8, 5. doi: 10.1186/s13617-019-0086-4 selva j., bonadonna c., branca s., de astis g., gambino s., paonita a., pistolesi m., ricci t., sulpizio r., tibaldi a., ricciardi a. (2020) multiple hazards and paths to eruptions: a review of the volcanic system of vulcano (aeolian islands, italy). earth-science reviews, 207, 103186. selva j., sandri l., taroni m., sulpizio r., tierz p., costa a. (2022) a simple two-state model interprets temporal modulations in eruptive activity and enhances multivolcano hazard quantification. science 281 the italian quaternary volcanism https://doi.org/10.18814/epiiugs/2003/v26i3/011 advances, 8(44), eabq4415. serri g., innocenti f., manetti p. (2001) magmatism from mesozoic to present: petrogenesis, timespace distribution and geodynamics implications. vai g.b., martini i.p. (eds.), anatomy of an orogen: the apennines and adjacent mediterranean basins, kluwer academic publisher, great britain, 77104. shackleton n.j. (1995) new data on the evolution of pliocene climatic variability. in: vrba e.s., denton g., partdrige h.t.c., burkle l.h. (eds.), paleoclimate and evolution, with emphasis on human origins, new haven, connecticut, yale university press, 242-248. shackleton n.j., berger a., peltier w.a. (1990) an alternative astronomical calibration of the lower pleistocene timescale based on odp site 677. transactions of the royal society of edinburgh: earth sciences, 81, 251-261. smith v.c., isaia r., pearce n.j.g. (2011) tephrostratigraphy and glass compositions of post-15 kyr campi flegrei eruptions: implications for eruption history and chronostratigraphic markers. quaternary science reviews, 30, 3638-3660. soligo m.l., tuccimei p. (2010) geochronology of colli albani volcano. in: r. funiciello, g. giordano (eds.), the colli albani volcano, special publications of iavcei, 3, geological society london, london (2010), 99-106. sollevanti f. (1983) geologic, volcanologic and tectonic of the vico-cimino area, italy. journal of volcanology and geothermal research, 17, 203-217. sottili g., palladino d.m., zanon v. (2004) plinian activity during the early eruptive history of the sabatini volcanic district, central italy. journal of volcanology and geothermal research, 308, 135, 361-379. sottili g., palladino d.m., marra f., jicha b., karner d.b., renne p. (2010a) geochronology of the most recent activity in the sabatini volcanic district, roman province, central italy. journal of volcanology and geothermal research, 196, 20-30. sottili g., taddeucci j., palladino d.m. (2010b) constraints on magma-wall rock thermal interaction during explosive eruptions from textural analysis of cored bombs. journal of volcanology and geothermal research, 308, 192, 27-34. sottili g., palladino d.m., gaeta m., masotta m. (2012) origins and energetics of maar volcanoes: examples from the ultrapotassic sabatini volcanic district (roman province, central italy). bulletin of volcanology, 74, 163-186. sottili g., arienzo i., castorina f., gaeta m., giaccio b., marra f., palladino d.m. (2019) time-dependent sr and nd isotope variations during the evolution of the ultrapotassic sabatini volcanic district (roman province, central italy). bulletin of volcanology, 81, 67. sparks r.s.j. (1975) stratigraphy and geology of the ignimbrites of vulsini volcano, central italy. geologische rundschau, 64, 497-523. speranza f., landi p., d’ajello caracciolo f., pignatelli a. (2010) paleomagnetic dating of the most recent silicic eruptive activity at pantelleria (strait of sicily). bulletin of volcanology, 72, 847-858. speranza f., di chiara a., rotolo s.g. (2012) correlation of welded ignimbrites on pantelleria, using paleomagnetism. bulletin of volcanology, 74, 341 357. stoppa f., principe c. (1997) eruption style and petrology of anew carbonatitic suite from the mt. vulture southern italy: the monticchio lakes formation. journal of volcanology and geothermal research, 78, 251-265 stoppa f., principe c., giannandrea p. (2008) comments on: carbonatites in a subduction system: the pleistocene alvikites from mt. vulture (southern italy) by d'orazio et al., (2007). lithos, 103, 550556. stothers r.b., rampino m.r. (1983) volcanic eruptions in the mediterranean before a.d.630 from written and archaeological sources. journal of geophysical research, 88 (b8), 6357-6371. suiting i., schmincke h.u. (2010) iblean diatremes 2: shallow marine volcanism in the central mediterranean at the onset of the messinian salinity crisis (iblean mountains, se-sicily) a multidisciplinary approach. international journal of earth sciences, 99, 1917-1940. suiting i., schmincke h.u. (2012) iblean diatremes 3: volcanic processes on a miocene carbonate platform (iblean mountains, se-sicily): a comparison of deep vs. shallow marine eruptive processes. bulletin of volcanology, 74, 207-230. sulli a. (2000) structural framework and crustal characteristics of the sardinia channel alpine transect in the central mediterranean. tectonophysics, 324, 321-336. sulpizio r., mele d., dellino p., la volpe l. (2005) a complex, subplinian-type eruption from lowviscosity, phonolitic to tephri-phonolitic: the ad 472 (pollena) eruption of somma-vesuvius, italy. bulletin of volcanology, 67, 743-767. doi: 10.1007/s00445-005-0414-x sulpizio r., bonasia r., dellino p., di vito m.a., la volpe l., mele d., zanchetta g., sadori l. (2008) discriminating the long distance dispersal of fine ash from sustained columns or near ground ash clouds: the example of the pomici di avellino eruption (somma-vesuvius, italy). journal of volcanology and geothermal research, 177, 263-276. sulpizio r., folch a., costa a., scaini c., dellino p. (2012) hazard assessment of far-range volcanic ash dispersal from a violent strombolian eruption at somma-vesuvius volcano, naples, italy: implications on civil aviation. bulletin of volcanology, 74, 2205-2218. sulpizio r., lucchi f., forni f., massaro s., tranne c.a. (2016) unravelling the effusive-explosive transitions and the construction of a volcanic cone from geological data: the example of monte dei porri, salina island (italy). journal of volcanology and geothermal research, 327, 1-22. tanguy j.c. (1978) tholeiitic basalt magmatism of mount etna and its relations with the alkaline series. contributions to mineralogy and petrology, 66, 51-67. tanguy j.c., condomines m., kieffer g. (1997) evolution of mount etna magma: constraints on the pre 282 branca s. et al. sent feeding system and eruptive mechanism. journal of volcanology and geothermal research, 75, 221-250. thompson m.a., lindsay j.m., gallard j.c. (2015) the influence of probabilistic volcanic hazard map properties on hazard communication journal of applied volcanology, 4, 6. doi: 10.1186/s13617-015-0023-0 tibaldi a. (2001) multiple sector collapses at stromboli volcano, italy: how they work. bulletin of volcanology, 63, 112-125. tibaldi a., vezzoli l. (2004) a new type of volcano flank failure: the resurgent caldera sector collapse, ischia, italy. geophysical research letters, 31(14), l14605. tierz p., sandri l., costa a., zaccarelli l., di vito m. a., sulpizio r., marzocchi w. (2016) suitability of energy cone for probabilistic volcanic hazard assessment: validation tests at somma-vesuvius and campi flegrei (italy). bulletin of volcanology, 78 (11), 79 tinti s., manucci a., pagnoni g., armigliato a., zaniboni f. (2005) the 30 december 2002 landslideinduced tsunamis in stromboli: sequence of the events reconstructed from the eyewitness accounts. natural hazards and earth system sciences, 5, 763-775. titos m., martínez montesinos b., barsotti s., sandri l., folch a., mingari l., macedonio g., costa a. (2022) long-term hazard assessment of explosive eruptions at jan mayen (norway) and implications for air traffic in the north atlantic. natural hazards and earth systems science 22, 139-163. doi: 10.5194/nhess-22-139-2022 tomlinson e.l., arienzo i., wulf s., smith v.c., carandente a., civetta l., hardiman m., orsi g., rosi m., thirlwall m., muller w., menzies m.a. (2012) campi flegrei italy: geochemistry of the proximal sources for major mediterranean tephras (c-1, c-2, y-3 & y-5). geochimica et cosmochimicha acta, 93,102-128. doi: 10.1016/j.gca.2012.05.043 tomlinson e.l., albert p.g., wulf s., brown r.j., smith v.c., keller j., orsi g., bourne a.j., menzies m.a. (2014) age and geochemistry of tephra layers from ischia, italy: constraints from proximal-distal correlations with lago grande di monticchio. journal of volcanology and geothermal research, 287, 22-39. tonarini s., armienti p., d’orazio m., innocenti f., pompilio m., petrini r. (1995) geochemical and isotopic monitoring of mt. etna 1989 1993 eruptive activity: bearing on the shallow feeling system. journal of volcanology and geothermal research, 64, 95-115. tonarini s., d'orazio m., armienti p., innocenti f., scribano v. (1996) geochemical features of eastern sicily lithosphere as probed by hyblean xenoliths and lavas. european journal of mineralogy, 8, 1153-1173. tonarini s., armienti p., d’orazio m., innocenti f. (2001) subduction-like fluids in the genesis of mt. etna magmas: evidence from boron isotopes and fluid mobile elements. earth and planetary science letters, 192, 471-483. tonarini s., leeman w.p., civetta l., d'antonio m., ferrara g., necco a. (2004) b/nb and δ11b systematics in the phlegrean volcanic district (pvd). journal of volcanology and geothermal research, 113, 123-139. tonarini s., d’antonio m., di vito m.a., orsi g., carandente a. (2009) geochemical and isotopical (b, sr, nd) evidence for mixing and mingling processes in the magmatic system feeding the astroni volcano (4.1-3.8 ka) within the campi flegrei caldera (south italy). lithos, 107, 135-151. doi: 10.1016/j.lithos.2008.09.012 trigila r., agosta e., currado c., de benedetti a.a., freda c., gaeta m., palladino d.m., rosa c. (1995) petrology. in: trigila r. (ed.), the volcano of the alban hills. università degli studi di roma "la sapienza", rome, italy, 95-165. trua t., esperança s., mazzuoli r. (1998) the evolution of the lithospheric mantle along the n. african plate: geochemical and isotopic evidence from the tholeiitic and alkaline volcanic rocks of the hyblean plateau, italy. contributions to mineralogy and petrology, 131, 307-322. trua t., serri g., rossi p.l. (2004) coexistence of iabtype and oib-type magmas in the southern tyrrhenian back-arc basin: evidence from recent seafloor sampling and geodynamic implications. in: from seafloor to deep mantle: architecture of the tyrrhenian backarc basin. memorie descrittive della carta geologica d’italia, lxiv, 83-96. trua t., serri g., marani m. (2007) geochemical features and geodynamic significance of the southern tyrrhenian backarc basin. geological society of america, special paper 418, 221-233. valentine g.a., sottili g., palladino d.m., taddeucci j. (2015) tephra ring interpretation in light of evolving maar-diatreme concepts: stracciacappa maar (central italy). journal of volcanology and geothermal research, 308, 19-29. valentine g.a., palladino d.m., diemkaye k., fletcher c. (2019) lithic-rich and lithic-poor ignimbrites and their basal deposits: sovana and sorano formations (latera caldera, italy). bulletin of volcanology, 81, 29. ventura g. (2013) kinematics of the aeolian volcanism (southern tyrrhenian sea) from geophysical and geological data. geological society, london, memoirs, 37, 3-11. ventura g., vilardo g., bruno p.p. (1999) the role of flank failure in modifying the shallow plumbing system of volcanoes: an example from sommavesuvius, italy. geophysical research letters, 26, 3681-3684. ventura g., milano g., passaro s., sprovieri m. (2013) the marsili ridge (southern tyrrhenian sea, italy): an island-arc volcanic complex emplaced on a ‘relict’ back-arc basin. earth science reviews, 116, 85-94. vezzoli l. (1988) island of ischia. quaderni de ‘la ricerca scientifica’ del cnr progetto finalizzato geodinamica. monografie finali, 10, 134. vezzoli l., conticelli s., innocenti f., landi p., manetti p., palladino d.m., trigila r. (1987) stratigraphy 283 the italian quaternary volcanism of the latera volcanic complex: proposals for a new nomenclature. periodico di mineralogia, 56, 89 -110. vezzoli l., principe c., malfatti j., arrighi s., tanguy jc., le goff m. (2009) modes and times of caldera resurgence: the <10 ka evolution of ischia caldera, italy, from high-precision archaeomagnetic dating. journal of volcanology and geothermal research, 186, 305-319. viccaro m., cristofolini r. (2008) nature of mantle heterogeneity and its role in the short-term geochemical and volcanological evolution of mt. etna (italy). lithos, 105, 272-288. viccaro m., zuccarello f. (2017) mantle ingredients for making the fingerprint of etna alkaline magmas: implications for shallow partial melting within the complex geodynamic framework of eastern sicily. journal of geodynamics, 109, 10-23. viccaro m., nicotra e., millar i.l., cristofolini r. (2011) the magma source at mount etna volcano: perspectives from the hf isotope composition of historic and recent lavas. chemical geology, 281, 343351. viccaro m., giuffrida m., zuccarello f., scandura m., palano m., gresta s. (2019) violent paroxysmal activity drives self-feeding magma replenishment at mt. etna. scientific reports, 9, 6717. viccaro m., cannata a., cannavò f., de rosa r., giuffrida m., nicotra e., petrelli m., sacco g. (2021) shallow conduit dynamics fuel the unexpected paroxysms of stromboli volcano during the summer 2019. scientific reports, 11(1), 266. doi: 10.1038/s41598-020-79558-7 villa i.m., buettner a. (2009) chronostratigraphy of monte vulture volcano (southern italy): secondary mineral microtextures and 39ar-40ar systematics. bulletin of volcanology, 71, 1195-1208 villa i.m., giuliani o., de grandis g., cioni r. (1989) datazioni k/ar dei vulcani di tolfa e manziana (in italian). bollettino gruppo nazionale di vulcanologia, 5, 1025-1026. villa i.m., calanchi i., dinelli e., lucchini f. (1999) age and evolution of the albano crater lake (roman volcanic province). acta vulcanologica, 11, 305310. vinkler a.p., cashman k., giordano g., groppelli g. (2012) evolution of the mafic villa senni calderaforming eruption at colli albani volcano, italy, indicated by textural analysis of juvenile fragments. journal of volcanology and geothermal research, 235-236, 37-54. walker g.p.l. (1984) downsag calderas, ring faults, caldera sizes, and incremental caldera growth. journal of geophysical research solid earth, 89 (b10), 8407-8416. washington h.s. (1906) the roman comagmatic region. carnegie institution washington publications, 57, p.p. 199. webster j.d., raia f., tappen c., de vivo b. (2003) pre eruptive geochemistry of the ignimbrite-forming magmas of the campanian volcanic zone, southern italy, determined from silicate melt inclusions. mineralogy and petrology, 79, 99-125. white j.c., neave d.a., rotolo s.g., parker d.f. (2020) geochemical constraints on basalt petrogenesis in the strait of sicily rift zone (italy): insights into the importance of short lengthscale mantle heterogeneity. chemical geology, 545, 1-18. wohletz k., orsi g., de vita s. (1995) eruptive mechanisms of the neapolitan yellow tuff interpreted from stratigraphic, chemical and granulometric data. journal of volcanology and geothermal research, 67, 263-290 wulf s., kraml m., keller j., negendank j.f.w. (2004) tephrochronology of the 100 ka lacustrine sediment record of lago grande di monticchio (southern italy). quaternary internationa, 122, 7-30. wulf s., kraml m., keller j. (2008) towards a detailed distal tephrostratigraphy in the central mediterranean: the last 20,000 yrs record of lago grande di monticchio. journal of volcanology and geothermal research, 177, 118-132. wulf s., keller j., paterne m., mingrama j., lauterbach s., opitz s., sottili g., giaccio b., albert p.g., satow c., tomlinson e.l., viccaro m., brauer a. (2012) the 100-133 ka record of italian explosive volcanism and revised tephrochronology of lago grande di monticchio. quaternary science reviews, 58, 104-123. zanchetta g., sulpizio r., roberts n., cioni r., eastwood w.j., siani g., caron b., paterne m., santacroce r. (2011) tephrostratigraphy, chronology and climatic events of the mediterranean basin during the holocene: an overview. holocene 21, 33-52. zuccarello f., schiavi f., viccaro m. (2021) magma dehydration controls the energy of recent eruptions at mt. etna volcano. terra nova, 33, 423-429. zuccarello f., schiavi f., viccaro m. (2022) the eruption run-up at mt. etna volcano: constraining magma decompression rates and their relationships with the final eruptive energy. earth and planetary science letters, 597, 11782. 284 ms. received: march 7, 2023 revised: may 20, 2023 accepted: may 24, 2023 avaiable online: june 29, 2023 branca s. et al. imp. sulpizio aa rreevviieeww ooff tteepphhrroossttrraattiiggrraapphhyy iinn cceennttrraall aanndd ssoouutthheerrnn iittaallyy dduurriinngg tthhee llaasstt 6655 kkaa rroobbeerrttoo ssuullppiizziioo11,,22,, ggiioovvaannnnii zzaanncchheettttaa22,, mmaarrttiinnee ppaatteerrnnee33 && ggiiuusseeppppee ssiiaannii44 1 dipartimento geomineralogico, via orabona 4, 70125, bari, italy 2 dipartimento di scienze della terra, via s. maria 53, 56126, pisa, italy 3 lab. des sciences du climat et de l’environm., cnrs-cea, 91198 gif sur yvette, france 4 fre 2566 orsayterre université paris xi 91405 orsay cedex abstract this work presents an attempt at correlating tephra layers through different proxies in central and southern italy over the last 65 ka. on the basis of the recent refinement of stratigraphy of some italian volcanoes (mainly somma-vesuvius and phlegrean fields) and new lacustrine and marine cores (from lago grande di monticchio and south adriatic sea) 35 dated tephra layers among terrestrial, lacustrine and marine settings are correlated. these correlations supply a detailed and comprehensive chronostratigraphic scheme previously not available. in particular, 9 tephra layers were related to the somma-vesuvius, 16 to the phlegrean fields, 3 to ischia, and 1 to procida, etna, lipari, salina, pantelleria and palinuro seamount explosive activity. one tephra layer has an uncertain source between ischia island and phlegrean fields. finally, dispersal maps of selected tephra layers are shown. riassunto questo lavoro presenta un tentativo di correlazione di livelli di tephra di età minore di 65 ka rinvenuti in depositi marini e lacustri con i corrispondenti livelli piroclastici prossimali. l'area interessata dall'indagine comprende carote marine dai mari tirreno, adriatico, ionio e dal bacino di bannock, mentre i dati dei tephra lacustri provengono da carote ottenute nei laghi di monticchio, vico, mezzano, nemi, valle di castiglione e da depositi di versante della conca del fucino. una carota proviene inoltre dalla laguna di mljet in croazia. le correlazioni di dettaglio dei tephra marini e lacustri con i depositi prossimali sono state possibili grazie al recente raffinamento dei dati riguardanti la cronostratigrafia di alcuni vulcani italiani (in particolare somma-vesuvio e campi flegrei) e ai dati provenienti da nuove carote perforate nel mare adriatico e nel lago grande di monticchio. dei 35 livelli di tephra correlati 9 appartengono ad eruzioni del somma-vesuvio, 16 ai campi flegrei, 3 ad ischia e 1 a procida, etna, lipari, salina, pantelleria e palinuro seamount rispettivamente. un solo livello di tephra risulta difficilmente discriminabile tra una origine flegrea o ischitana. infine le mappe di dispersione di alcuni di questi livelli di tephra sono state tracciate sulla base dei dati prossimali e delle carote marine e lacustri distali. keywords: tephra layers, marine, lacustrine, proximal deposits, italian volcanoes, central mediterranean sea. parole chiave: livelli di tephra, tephra marini, tephra lacustri, vulcani italiani, mediterraneo centrale. il quaternario italian journal of quaternary sciences 1166(1), 2003, 91-108 iinnttrroodduuccttiioonn over the last 50 years, tephra layers have been extensively investigated, since their widespread presence in marine and lacustrine sediments are an invaluable tool used to support geochronological and climatological studies (kennett, 1982; mangerud et al., 1984; bard et al., 1994; paterne et al., 1990; siani et al., 2001; tonthat et al., 2001, among many others). indeed, tephrochronological studies provide precise chronostratigraphic constraints for proxy records and their correlation. moreover, they improve our knowledge of both the areas affected by pyroclastic deposition and the mass of erupted magmas in the past (sparks & huang, 1980). these data are of primary importance in volcanic hazard mitigation, as they are hardly obtained only from terrestrial data. this is especially true for the distal products of ancient eruptions. in the mediterranean sea, a lot of research has dealt with the study of marine cores from tyrrhenian, adriatic, aegean or levantine seas. one of the earliest drilling expeditions in the area was carried out in 194748 (norin, 1958), but the first comprehensive study of tephra layers is that of keller et al. (1978). further on, a refinement of the data was provided by paterne et al. (1986; 1988), mccoy & cornell (1990), fontugne et al. (1989), vezzoli (1991), calanchi et al. (1994), siani et al. (2003) for the tyrrhenian, adriatic and south ionian (bannock basin) seas. in particular, paterne et al. (1986; 1988) and paterne & guichard (1993) provided a detailed chronological and geochemical record of tephra layers over the last 80,000 years. on the other hand tephra layers in lacustrine settings were investigated in detail in recent years, mostly inside the eu funded projects paliclas and euromaars (i.e. narcisi, 1996; calanchi et al., 1996a; 92 r. sulpizio et al. calanchi et al., 1996b; watts et al., 1996; narcisi, 1999a; ramrath et al., 1999). several sedimentary successions of some lakes from central and southern italy were drilled and investigated by interdisciplinary research. in particular, seven lakes (fig. 1) have been considered in this work (lakes of mezzano, vico, albano, nemi, valle di castiglione, monticchio and fucino basin), owing to the presence in their sediments of tephra layers of interest in the investigated time span (<65 ka). this large set of data on marine and lacustrine tephra can be profitably matched with the new stratigraphic, geochemical and chronological data obtained in recent years for some important quaternary volcanoes of southern italy, such as somma-vesuvius (andronico et al., 1995; 1996; cioni et al., 2003a), phlegrean fields (orsi et al., 1996a; di vito et al., 1999; pappalardo et al., 1999; sulpizio et al., 2003), mt etna (coltelli et al., 2000). this paper deals with a review of tephrochronologic correlations among terrestrial (intended as deposits recognised on land, mostly in proximal sites), lacustrine and marine proxies of central-southern italy, with the aim of proposing a comprehensive chronostratigraphic scheme of the tephra succession and dispersion for the last 65 ka. in particular, thephrochronologic correlations are better detailed for the last 18 ka, owing to the availability of a major amount of data on both marine-lacustrine and terrestrial environments (andronico et al., 1995; narcisi, 1996; di vito et al., 1999; siani et al., 2001; wulf et al., 2001; siani et al., 2003 ). however, the correlation in 18-65 ka time span are mainly based on the work of sulpizio et al. (2003), which correlate several poorly-known terrestrial deposits to marine tephra of adriatic and tyrrhenian seas. tthhee tteerrrreessttrriiaall rreeccoorrdd in the investigated time span (<65 ka) the explosive activity of the italian volcanoes was mainly concentrated in the neapolitan area (rosi & sbrana, 1987; santacroce, 1987; poli et al., 1987; vezzoli, 1988; andronico et al., 1995; orsi et al., 1996a; di vito et al., 1999; sulpizio et al., 2003), while few large explosive eruptions occurred at mount etna (kieffer, 1979; coltelli et al., 2000) and eolian islands (keller, 1980; pichler, 1980; frazzetta et al., 1983; crisci et al., 1991; calanchi et al., 1993; de astis et al., 1997; gioncada et al., 2003). during this time span, the roman province, mount vulture and roccamonfina volcanoes were not active, while pantelleria was characterised by a very weak activity out the green tuff eruption (45 ka; gillot, 1984; civetta et al., 1984; mahood & hildreth, 1986; orsi et al., 1991). the stratigraphic record of neapolitan volcanoes has been improved in recent years, especially for the late pleistocene-holocene. in particular, detailed sets of both stratigraphic, chronologic and geochemical data are available for somma-vesuvius (santacroce, 1987; andronico et al., 1995; cioni et al., 2003a) and phlegrean fields (rosi & sbrana, 1987; di vito et al., 1999; orsi et al., 1996a; pappalardo et al., 1999; sulpizio et al., 2003). minor detail exists for the data from ischia and procida volcanoes (vezzoli, 1988; di girolamo & stanzione, 1973; poli et al., 1987; crisci et al., 1989; orsi et al., 1996b). all these data allow the reconstruction of a general chronostratigraphic scheme of the activity of these volcanoes (fig. 2). in the same figure the major explosive eruptions of eolian islands, palinuro seamount and etna volcano are also reported (crisci et al., 1991; calanchi et al., 1993; de astis et al., 1997; coltelli et al., 2000). from this chronostratigraphic scheme, the explosive activity of somma-vesuvius and phlegrean fields emerges characterising the last 18 ka, whereas phlegrean explosive activity dominates the 1865 ka time span, with only few explosive events of pantelleria, ischia and procida islands. tables 1 and 2 summarises the chronology and the main lithological and chemical characteristics of the proximal pyroclastic deposits used in this work for the correlation with marine and lacustrine tephra layers. figure 1 location map of the lacustrine and marine cores considered for this study. lmz – lago di mezzano (ramrath et al., 1999; narcisi, 1999b); vico – lago di vico (narcisi, 1999b); palb1e – lago di albano, lago di nemi and valle di castiglione (calanchi et al., 1996a; narcisi, 1999a); fuc – conca del fucino (slope deposits on the border of the basin; narcisi, 1993); mon – lago grande di monticchio (narcisi et al., 1996; wulf , 2000; wulf et al., 2001); mlj – mljet lagoon (jahns & van den bogaard, 1998); pal948, pal9466, cm9241, cm9242, rf9230 – central adriatic sea cores (calanchi et al., 1998); ket8216, ket8218, md90-917 – south adriatic sea cores (paterne et al., 1988; fontugne et al., 1989; siani et al., 2001; 2003); ket8003, 8004, 8011, 8019, 8022, odp leg 107 – tyrrhenian sea cores (paterne et al., 1988; kallel et al., 1997; calanchi et al., 1994); v10-69, rc9191 – ionian sea cores (keller et al., 1978); ban – bannock basin cores (vezzoli, 1991). 93a review of tephrostratigraphy ... figure 2 detailed chronostratigraphic scheme of somma-vesuvius and phlegrean fields volcanoes of the last 65 ka. in the sommavesuvius chronostratigraphy are shown in italic two eruptions attributed to phlegrean fields (andronico, 1997; zanchetta et al., 2000). schemes of the main explosive eruptions of etna, eolian islands, ischia and procida islands are also shown. the explosive eruption of palinuro seamount is enclosed in the eolian islands chronostratigraphy. note the change in scale for ages older than 19 ka and for eolian islands column. in brackets are shown the published 14c or 39ar/40ar ages. a deino et al. (1994); b ton-that et al. (2001); c pescatore and rolandi (1981); d de rita et al. (1991). 94 tthhee llaaccuussttrriinnee rreeccoorrdd in recent years seven lakes in central and southern italy (lakes mezzano, vico, albano, nemi, valle di castiglione, fucino and monticchio; fig. 1) were drilled, mainly with the aim of studying environmental and climatic conditions in central-southern italy in the past. tephra layers recognised in these lacustrine environments have been investigated in detail by calanchi et al. (1996a, b), ramrath et al. (1999), narcisi (1996; 1999a, b), wulf (2000) and wulf et al. (2001). the lago grande di monticchio (mt vulture; fig. 1) shows the most abundant and representative record of tephra layers, due to its location downwind of the neapolitan volcanoes (fig. 1). narcisi (1996) provided the correlation of 13 tephra layers from the lago grande di monticchio succession to the activity of neapolitan volcanoes, while wulf (2000) and wulf et al. (2001) reported the same layers and several others not recognised by narcisi (1996; fig. 3). indeed, wulf et al. (2001) reported the occurrence of many tephra layers of unknown origin, but, unfortunately, they did not provided chemical analyses, thus preventing their correlations to terrestrial or marine correspondents. for this reason only the well-known and widespread tephra layers y3 and y1, together with the trachytic tephra of agnano m. spina, the latitic tephra of solchiaro and the leucititictephrite-phonolite tephra of pollena (ad 472) have been added to the lago grande di monticchio succession reported by narcisi (1996). the tephra layers recognised in the lago grande di monticchio cores pertain to the major explosive eruptions of somma-vesuvius and phlegrean fields, which occurred in the last 18 ka, whereas the origin of tephra layers in the 18-65 ka time span is less clear, even if the predominance of phlegrean fields and ischia island sources can be inferred by geochemical data (narcisi, 1996; sulpizio et al., 2003; fig. 3). figure 3 shows some differences in respect to the previous correlations of tephra layers from lago grande di monticchio made by narcisi (1996). in particular, layer l3, previously attributed to the interplinian activity between avellino and ad 79 eruptions of sommavesuvius (narcisi, 1996), has been correlated to the avellino eruption of somma-vesuvius. this different correlation has been suggested by eds chemical analyses (especially by the high content of al2o3; cioni et al., 2000) and dispersal of fall deposits of aps and avellino r. sulpizio et al. table 1 chronology and main lithological characteristics of the proximal terrestrial deposits of the last 18.3 ka correlated to the marine and lacustrine tephra layers. a14c age from andronico et al. (1995); b14c age from siani et al. (2001; 2003); c14c age from di vito et al. (1999); d14c age from calanchi et al. (1993). e-lacustrine layer from wulf et al. (2001), marine layer from fontugne et al. (1989); fkeller et al. (1978); g-narcisi et al. (1996), attribution to avellino eruption: this work; h-siani et al. (2003); i-calanchi et al. (1998); lpaterne et al. (1988), paterne & guichard (1993), paterne (1985).characteristics of proximal deposits and lithology of juvenile fragments of pollena, pompeii, avellino, mercato, greenish, pomici di base from santacroce (1987); ap1-2 from andronico & cioni (2002); astroni, agnano p.p. and neapolitan yellow tuff from rosi & sbrana (1987); agnano m. spina from de vita et al. (1999); gabellottofiumebianco from crisci et al. (1991); gm1 from zanchetta et al. (2000); upper pollara from calanchi et al. (1993); lagno amendolare from andronico (1997); biancavilla ignimbrite from de rita et al. (1991). eerruuppttiioonn aaggee cchhaarraacctteerriissttiiccss ooff pprrooxxiimmaall lliitthhoollooggyy ooff jjuuvveenniillee ffrraaggmmeennttss iinnffeerrrreedd tteepphhrraa ddeeppoossiittss ssoouurrccee llaayyeerr pyroclastic fall deposit comprises greenish-grey pumice: highly a thin basal layer of greenish-grey vesicular, porphyritic (lc+pyr+san). pumice followed by several layers tephri-phonolitic chemical somma-ppoolllleennaa ad 472 of dark grey scoria. accidental composition. dark grey scoria: highly vesuvius pollenae lithics are mainly carbonate and to incipiently vesicular, porphyritic lava fragments. pyroclastic (lc+pyr+san). leucititic-tephriteflows abundant in proximal areas. phonolite chemical composition. pyroclastic fall deposit comprises white-pinkish pumice: highly a basal layer of white-pinkish vesicular, moderately porphyritic pumice followed by an upper (san). phonolitic chemical somma-ppoommppeeiiii ad 79 layer of grey pumice. accidental composition. grey pumice: highly to vesuvius z1f lithics are mainly carbonate and moderately vesicular, moderately lava fragments. pyroclastic flows porphyritic (san+pyr). tephriabundant in proximal areas. phonolitic chemical composition. pyroclastic fall deposits comprise white pumice: highly vesicular, a thin basal layer of white pumice almost aphiric. phonolitic chemical somma-aapp11--22 3,220±65a followed by an alternation of grey composition. grey scoria: highly to vesuvius l1-2g scoria and ash beds. pyroclastic moderately vesicular, moderately flow deposits are very scarce. porphyritic (san+pyr). pyroclastic fall deposit comprises a white pumice: highly vesicular, basal layer of white pumice followed porphyritic (san). phonolitic chemical by an upper layer of grey pumice. composition. grey pumice: highly to aavveelllliinnoo 3,760±70a accidental lithics are mainly moderately vesicular, porphyritic sommal3g carbonate and lava fragments with (san+pyr). tephri-phonolitic chemical vesuvius subordinate syenites, cumulates and composition. skarns. pyroclastic flows abundant in proximal areas. 95a review of tephrostratigraphy ... eerruuppttiioonn aaggee cchhaarraacctteerriissttiiccss ooff pprrooxxiimmaall lliitthhoollooggyy ooff jjuuvveenniillee ffrraaggmmeennttss iinnffeerrrreedd tteepphhrraa ddeeppoossiittss ssoouurrccee llaayyeerr massive deposit formed by light grey highly vesicular, porphyritic aassttrroonnii 33 3,820±50b pumice. sparse accidental lithics, (san+plag+pyr+bt), light grey in phlegrean 140-17h mainly lava fragments. pyroclastic colour. trachytic to alkali-trachytic in fields flows abundant in proximal areas. composition. pyroclastic fall deposit comprises highly vesicular, porphyritic several poorly sorted pumice layers (san+plag+pyr+bt+lc). pumice aaggnnaannoo 4,130±50c separated by thin, fine ash beds. fragments show a yellowish patina. phlegrean amsi mm.. ssppiinnaa accidental lithics are hydrotermally inner colour: grey; outer colour: fields altered lava fragments. pyroclastic yellowish-brown. trachytic to alkaliflows abundant in proximal areas. trachytic chemical composition. ggaabbeelllloottttoo-several pumice and ash layers highly vesicular, almost aphiric. lipari 7,770±35b interbedded by massive and colour: white. rhyolitic chemical (eolian) e1l ffiiuummeebbiiaannccoo cross-stratified ashes composition islands) pyroclastic fall deposit comprises highly vesicular , almost aphyric. three main layers of white brown colour: white. phonolitic chemical pumice separated by thin, pinkishcomposition. somma-mmeerrccaattoo 8,010±35a brown ash beds. accidental lithics v-1l are mainly lava fragments and vesuvius subordinate carbonates. pyroclastic flows abundant in proximal areas. ppaalliinnuurroo co-ignimbrite deposits of brown, variably vesicular glass shards of palinuro9,990±90b fine ash. trachytic composition 275-17 h sseeaammoouunntt accidental lithics are absent. seamount pyroclastic fall deposit comprises highly vesicular , porphyritic three main layers of light brown (san+plag+pyr+bt). pumice fragments aaggnnaannoo 10,480±90b pumice separated by thin, fine ash show a pinkish-brown patina. inner phlegrean c1l pp.. pp.. beds. accidental lithics are lava colour: grey; outer colour: pinkishfields fragments. pyroclastic flows brown. trachytic chemical abundant in proximal areas. composition. several pumice and ash layers juvenile fragments are highly nneeaappoolliittaann 12,100±170b interbedded by massive and vesicular, light grey in colour, almost phlegrean c2s.l. l yyeellllooww ttuuffff cross-stratified ashes aphiric (san+pl+pyr+bt) and alkalifields /395-17h trachytic to latitic in composition. pyroclastic fall deposit comprises an highly vesicular, aphiric, light grey in alternation of three layers of vesicular colour. trachytic chemical phlegrean ggmm11 12,600±110b ash and light coloured pumice. composition. 405-17 h a thick co-ignimbrite ash layer forms fields the upper part of the deposits. uuppppeerr alternation of pyroclastic fall highly vesicular, porphyritic salina 12,750±140d and flow deposits that comprise (bt+pyr+hbl+ol+pl), white in colour. (eolian e2l ppoollllaarraa white pumice. dacitic chemical composition. islands) pyroclastic fall deposit comprises a highly vesicular, aphiric. colour light basal layer of white pumice followed to dark grey. both types are trachytic llaaggnnoo 13,070±90b by fine brown ashes. upper layer in composition. phlegrean 435-17h aammeennddoollaarree comprises mixed white and black fields pumice. sparse accidental lithics, mainly lava fragments. bbiiaannccaavviillllaa at least four ignimbritic flow units highly to moderately vesicular. mount14,230±85b of ash and juvenile scoriae. colour varies from light to dark grey. y1 f/et1l iiggnniimmbbrriittee benmoreitic composition. etna pyroclastic fall deposit comprises highly to moderately vesicular, almost an alternation of fine to coarse lapilli aphiric (san+pyr). colour from light and ash layers. different types of grey to dark green and brown. ggrreeeenniisshh 16,070±170b juvenile clasts mixed in the same trachytic composition. sommal8 g/530ppuummiiccee layer. accidental lithics are lava vesuvius 17h and carbonate fragments. few pyroclastic flow deposits in proximal areas. pyroclastic fall deposit comprises a white pumice: highly vesicular, white pumice basal layer followed by almost aphiric (san+pyr), trachytic ppoommiiccii ddii a black scoriae upper layer. accidental composition. black scoriae: somma-18,300±180a lithics are lava and carbonate moderately vesicular, aphiric, latitic 595-17h bbaassee fragments. some pyroclastic composition. vesuvius flow deposits in proximal areas. segue table 1 96 eruptions (andronico & cioni, 2002; cioni et al., 2000). the correlation of layer l10 to the sarno eruption was questioned by sulpizio et al. (2003), on the basis of the attribution of the sarno deposits to the distal products of the pomici di base eruption (bertagnini et al., 1998; andronico et al., 1995; 1996). indeed, the layer l10 can be correlated to the tau1-e eruption , very similar in lithology (light and dark coloured juvenile fragments; table 2), chemical composition (trachytes-latites; table 3) and age (about 24 ka) to the previously attr ibuted sarno eruption. furthermore, the codola eruption, previously reported as a plinian eruption of sommavesuvius (santacroce, 1987), has been recently attributed to the activity of phlegrean fields, on the basis of lithology and dispersal of fall deposits (andronico et al., 1995; 1996; sulpizio et al., 2003). the recognition of tephra layers in cores from the other lakes is more sporadic and limited to the somma-vesuvius eruption of avellino (lago di nemi and lago di albano), biancavilla ignimbrite (lago di albano, lago di mezzano and in the slope deposits on the flanks of the fucino basin) and neapolitan yellow tuff (valle di castiglione; fig. 3). tthhee mmaarriinnee rreeccoorrdd siani (1999) and siani et al. (2001; 2003) provided a detailed study and correlation of 11 tephra layers of the last 18 ka from a core located in the adriatic sea (md90-917; fig. 1). three of these tephra layers belong to the eruptions of agnano m. spina (tephra ams/pf), agnano pomici principali (tephra c1) and biancavilla ignimbrite (tephra et1/y1) previously recognised in marine cores (keller et al., 1978; paterne et al., 1988; vezzoli, 1991; calanchi et al., 1998). a fourth tephra of rhyolitic composition (tephra e1) has been correlated to the gabellottofiumebianco eruption of lipari (eolian islands) on the basis of chemistry and chronology. the other seven tephra layers have been for the first time correlated to terrestrial proximal deposits, on the basis of their chemistry, lithology and chronology (table 1). two of them (tephra 595-17 and 530-17) have been related to the pomici di base (santacroce, 1987; bertagnini et al., 1998) and greenish (santacroce, 1987; cioni et al., 2003b) eruptions of somma-vesuvius respectively, whereas the tephra layer 275-17 has been related to the activity of palinuro seamount (fig. 4 and table 1). the other four tephra layers have been related to the phlegrean fields activity. in particular the tephra layer 140-17 has been correlated to the astroni eruption, while tephra layers 39517, 405-17, 435-17 clustered in a stratigraphic position very close to the previously recognised c2 tephra (paterne et al., 1988; calanchi et al., 1998), related to the neapolitan yellow tuff eruption (paterne et al., 1988). indeed, the accurate sampling of the core (every 3 cm; siani, 1999; siani et al., 2003) allowed to recognise three difr. sulpizio et al. figure 3 schematic correlation among tephra layers recognised in the lacustrine cores considered in this study. see fig. 1 for locations. * recognised in the detrital deposits on the flanks of fucino basin (narcisi, 1993). la go g ra nd e di m on tic ch io v ic o m ez za no v al le d i c as tig lio ne , 97a review of tephrostratigraphy ... table 2 chronology and main lithological characteristics of the proximal terrestrial deposits of the 18.3-65ka time span correlated to the marine and lacustrine tephra layers. m14c age from paterne et al. (1988); n14c age from sulpizio et al. (2003); o 14c and 39ar/40ar ages from deino et al. (1994) and ton-that et al. (2001); in italic are shown the ages calculated by interpolation of 14c data in marine cores (paterne et al. 1988; paterne & guichard, 1993). f-keller et al. (1978); g-narcisi et al. (1996); h-siani et al. (2003); l-paterne et al. (1988), paterne & guichard (1993), paterne (1985); p-calanchi et al. (1994). characteristics of proximal deposits and lithology of juvenile fragments of tau1-d, e, smp1-a, c, d, e, ca1-a, sc2-a, sa3-a, sa2-a, codola and s. lucia from sulpizio et al. (2003); solchiaro/taurano from di girolamo & stanzione (1973) and zanchetta et al. (2000); schiava pumice from zanchetta et al. (2000); campanian ignimbrite from rosi & sbrana (1987); green tuff of pantelleria from mahood & hildreth (1986); green tuff of ischia from vezzoli (1988). eerruuppttiioonn aaggee cchhaarraacctteerriissttiiccss ooff pprrooxxiimmaall lliitthhoollooggyy ooff jjuuvveenniillee ffrraaggmmeennttss iinnffeerrrreedd tteepphhrraa ((kkaa)) ddeeppoossiittss ssoouurrccee llaayyeerr massive layer formed by well poorly vesicular , sub-aphiric ssoollcchhiiaarroo 19.62±0.27m sorted, black, scoriaceous, coarse (amph+pyr+san). inner colour: n3procida c4l //ttaauurraannoo lapilli. sparse accidental lithics, dark grey; outer colour: n5-medium island mainly lava fragments. grey. latitic chemical composition. basal layer formed by light light coloured pumice: moderately coloured pumice followed by an vesicular, almost aphiric (amph+pyr). upper layer of black scoriae. colour n5, medium grey. trachytic phlegrean l10g ttaauu11--ee 24 accidental lithics are scarce and chemical composition. black scoriae: mainly are lava fragments. moderately vesicular, almost aphiric fields c6l (amph+pyr). colour n3, dark grey. latitic chemical composition. double alternation of fine grained, highly to medium vesicular, aphiric, vesicular ash and light to dark grey pumice and scoria. presence of pumice lapilli layers. fine grained banded pumice fragments. phlegrean l11g ccooddoollaa 25.1±0.4m pumice lapilli scatterly occur inside color:5y 8/1yellowish grey; fields c8l the ash layers. accidental lithics are n4-medium dark grey. dark coloured lava fragments. trachytic chemical composition. massive ash with sparse, light grey highly vesicular, aphiric, pumice. phlegreanssmmpp11--ee 25.82±0.27n pumice lapilli. absence of coarse color:5y 8/1-yellowish grey. y3f accidental lithic fragments. trachytic chemical composition. fields massive pyroclastic fall deposit of highly vesicular, aphiric pumice. light brown pumice lapilli. sparse inner colour: 5y 8/1-yellowish grey; phlegreanttaauu11--dd 27.8 accidental lithics mainly are lava outer colour: 10yr 8/2-very pale orange. fields 332-04l fragments. trachytic chemical composition massive pyroclastic fall deposit of highly vesicular, porphyritic brown, scoriaceous, coarse lapilli (pyr+bt+san) scoria. presence of with good sorting. sparse cumulate xenoliths. inner colour: 5y phlegreanssmmpp11--dd 28.5 accidental lithics, mainly are lava 6/1-light olive grey; outer colour: fields 360-18l fragments. 10yr 6/2-pale yellowish brown. latitic chemical composition alternation of 5 fine grained, light highly microvesicular, sub-aphiric sscchhiiaavvaa brown, vesicular ash and 4 well (bt+san), pumice. colour: n8-very ischia3366 sorted, light grey pumice lapilli light grey. trachytic chemical c-9l ppuummiiccee layers. accidental lithic are scarce composition island and are lava fragments. basal pyroclastic fall layer followed by pumice fragments are highly impressive pyroclastic flow deposits vesicular, moderately porphyritic ccaammppaanniiaann which form the ignimbrite s.s. large (san+bt). colour: from pinkish-brown phlegrean iiggnniimmbbrriittee 37-41o variability of juvenile fragments, which to light grey. trachytic chemical c13al comprise light coloured pumice and composition fields dark, porphyritic scoriae. accidental lithics are mainly lava fragments basal massive layer of pumice highly vesicular, sub-aphiric lapilli that graded into an alternation (san+bt+pyr), pumice. tubular phlegreanssmmpp11--cc ~40 of ash and lapilli. accidental lithics vesicles. colour: 5y 6/4-dusty yellow. fields c13bl are scarce and are lava fragments trachytic chemical composition massive, well to moderately sorted highly vesicular, sub-aphiric ischia layer of greyish pumice lapilli. (san+bt+pyr), pumice. tubular island/ssmmpp11--aa 4422 accidental lithics are scarce and vesicles. colour: 5y 6/1-light olive phlegrean c14l are lava fragments. grey. trachytic chemical composition fields alternation of pyroclastic fall and ggrreeeenn ttuuffff 45 flow deposits, sometimes welded pantelleria y6f in proximal areas. alternation of brown fine grained highly vesicular, sub-aphiric (san+bt), ash and light grey pumice lapilli pumice. tubular vesicles. inner layers. fine grained pumice lapilli colour: 5y 6/1-light olive grey; outer phlegreanssaannttaa lluucciiaa 47.5±2.6n scatterly occur inside the ash colour; 10yr 6/2-pale yellowish fields c15l layers. accidental lithics are dark brown. trachytic chemical coloured lava fragments. composition. ferent peaks of homogeneous glass shards in the 12-13 ka time span, correlable to the proximal pyroclastic deposits of lagno amendolare (tephra 435-17), gm1 (tephra 405-17) and neapolitan yellow tuff (tephra 39517; table 1). the record of tephra layers younger than 18 ka is completed by the recognition of e2, v1, avellino and z-1, respectively related to pollara eruption from salina island (eolian archipelago; paterne et al., 1988), mercato, avellino and ad 79 eruptions from sommavesuvius (keller et al., 1978; paterne et al., 1988; fontugne et al., 1989). anyway, the correlations regarding two of these tephra layers need some further comments. tephra layer z-1 has been related to the ad 79 eruption from somma-vesuvius, even if keller et al. (1978) reported a possible correlation with the avellino eruption from somma-vesuvius (3.8 ka; cioni et al., 1995; 2000). anyway, mineralogical characteristics of tephra layer z-1 (presence of melanite and leucite; keller et al., 1978) rules out the possible correlation with avellino deposits, characterised by the presence of scapolite and nepheline (cioni et al., 2000). up to now the tephra layers rf93-30 (530), recognised in the adriatic sea (calanchi et al., 1998), has not been correlated to a precise somma-vesuvius explosive event due to its chemical similarity to both ad 79 and avellino products (calanchi et al., 1998). indeed, both eds chemical analyses of proximal deposits (cioni et al., 2000), age of rf93-30 (530) tephra layer (>3660±100 yr bp; calanchi et al., 1998) and diversity in dispersal of fall deposits (ne for avellino, se for ad 79 deposits; cioni et al., 2000; sigurdsson et al., 1985) support the correlation of rf93-30 (530) tephra layer to the avellino eruption. the correlation of many of the tephra layers older than 18 ka with terrestrial deposits still remains difficult, with the only exceptions of the solchiaro eruption from procida island (tephra layer c4; paterne et al., 1988; paterne & guichard,1993), campanian ignimbrite eruption from phlegrean fields (tephra layer y5/c13; keller et al., 1978; paterne et al., 1988; ton-that et al., 2001) and green tuff from pantelleria (tephra layer y6; keller et al., 1978). several authors (keller et al., 1978; paterne et al.,1988; paterne & guichard,1993; calanchi et al., 1994; 1998) correlated numerous tephra layers of age between 18 and 65 ka from tyrrhenian and adriatic sea cores (fig. 4) to different sources such as etna, eolian islands and ischia volcanoes, usually grouping together phlegrean fields and somma-vesuvius due to the chemical homogeneity of their products. however, the contribution of somma-vesuvius to the tephra record in the 18-65 ka is negligible, as testified by the lack of pyroclastic deposits of comparable age in the terrestrial record (fig. 2). on the basis of lithology, chemistry and chronology (tables 2 and 3), sulpizio et al. (2003) correlated fourteen tephra layers of age between 18 and 65 ka to terrestrial pyroclastic deposits from phlegrean fields, ischia, and dubitatively sommavesuvius (fig. 5). these correlations allow to unravel some important points about the existence of many primary vs secondary tephra layers in this time span (questioned by mccoy & cornell, 1990 and narcisi & vezzoli, 1999) and the attribution of the tephra layers to precise volcanic sources, in many cases different to the previously hypotised (keller et al., 1978; paterne et al.; 1988; paterne & guichard, 1993; calanchi et al., 1994). in particular, tephra layers c6 and c8 (paterne, 1985; paterne et al., 1988) have been correlated to the pyro98 eerruuppttiioonn aaggee cchhaarraacctteerriissttiiccss ooff pprrooxxiimmaall lliitthhoollooggyy ooff jjuuvveenniillee ffrraaggmmeennttss iinnffeerrrreedd tteepphhrraa ((kkaa)) ddeeppoossiittss ssoouurrccee llaayyeerr massive, well to moderately sorted highly vesicular, sub-aphiric layer of greyish brown coarse (san+bt+pyr), coarse pumice lapilli. pumice lapilli. accidental lithics tubular vesicles. inner colour: 5y phlegreanccaa11--aa 51 are scarce and are lava fragments. 6/1-light olive grey; outer colour: fields c16l 10yr 6/2-pale yellowish brown. trachytic chemical composition mainly pyroclastic flow deposits, from highly to incipiently vesicular, sometimes welded in proximal porphyritic (san+pl+pyr). colour from ischia l14g ggrreeeenn ttuuffff 55 areas, rich in accidental lithics and whitish to yellowish. trachytic blocks of poorly vesicular juvenile chemical composition. island fragments. alternation of grey, fine grained fine grained, highly vesicular, sub pumice lapilli and brown coarse aphiric (bt), pumice lapilli. elongated ischiasscc22--aa 57 ash layers. accidental lithics are shape. tubular vesicles. colour: 5gy c(i)6l scarce and are lava fragments. 6/1-greenish grey. trachytic chemical island composition. basal layer formed by brown, fine highly vesicular, sub-aphiric (bt), ash followed by a well-sorted, pumice lapilli. colour 5y 6/4-dusty phlegrean c18l/y7f/ssaa33--aa 60.3 massive, yellowish brown pumice yellow. trachytic chemical lapilli layer. accidental lithics are composition. fields t003p scarce and are lava fragments. basal, dark coloured pumice lapilli highly vesicular, sub-aphiric layer overlaid by black, vesicular, (bt+px+san), pumice. inner colour: 5y somma-ssaa22--aa 62.3 fine ash with sparse fine pumice 4/1-olive grey; outer colour: 10yr 666-04l lapilli. accidental lithics are 6/2-pale yellowish brown. trachytic vesuvius reddish lava fragments. chemical composition. segue table 2 r. sulpizio et al. 99 ee rruu pptt iioo nn tt aa uu 11-ee ll11 00bb st . d ev . ll11 00aa st . d ev . cc 66 cc oodd ooll aa st . d ev . ll11 11 st . d ev . cc 88 w hi te a bl ac ka l. g re ya (n =2 ) d . g re ya s io 2 63 .3 61 .7 8 64 .2 3 1. 23 63 .8 7 0, 05 63 .5 8 58 .7 5 0. 04 60 .7 3 60 .0 1 0, 05 60 .4 t io 2 0. 56 0. 6 0. 39 0. 12 0. 41 0. 11 0. 32 0. 64 0. 01 0. 57 0. 55 0. 28 0. 23 a l 2 o 3 18 .0 2 19 .1 3 18 .3 6 0. 26 18 .2 4 0. 23 19 .4 18 .3 6 0. 02 18 .1 1 20 .5 6 1. 31 20 .0 2 f e 2 o 3 3. 21 3. 62 3. 26 0. 36 3. 21 0. 24 2. 66 4. 85 0. 44 4. 21 2. 79 1. 26 2. 69 m no 0. 15 0. 16 0. 16 0. 12 0. 1 0. 1 0. 14 0. 01 0. 13 0. 09 0. 07 m go 0. 7 0. 65 0. 38 0. 18 0. 5 0. 22 0. 34 5 1. 12 0. 33 0. 86 0. 47 0. 43 0. 04 c ao 2. 29 2. 4 2. 13 0. 2 2. 02 0. 19 2. 24 5 4. 8 0. 38 3. 93 4. 73 0. 92 3. 15 n a 2 o 4. 38 4. 05 2. 14 0. 29 2. 39 0. 41 3. 38 3. 55 0. 66 3. 78 2. 92 0. 52 4. 38 k 2o 7. 34 7. 53 8. 63 0. 63 8. 95 0. 45 8. 07 7. 7 1. 86 7. 56 7. 58 1. 36 9. 05 p 2o 5 0. 06 0. 07 0. 35 0. 23 0. 28 0. 15 0. 13 0. 03 0. 11 0. 26 0. 17 l. o .i. 4. 79 4. 52 3. 67 2. 65 6. 99 1. 55 3. 58 0. 06 2. 74 4. 62 1. 94 n b 67 74 53 9 54 z r 45 8 50 4 30 9 30 31 5 y 38 43 31 4 30 s r 86 1 91 6 11 25 95 10 37 r b 23 4 24 2 28 4 16 28 3 c e 27 0 28 4 13 3 12 14 2 b a 10 36 10 91 18 17 40 0 15 06 la 15 2 14 7 73 6 74 n i 3 4 6 1 6 c r 3 4 10 2 7 v 61 66 91 17 78 c o 4 5 9 1 6 t ot al 10 0. 01 99 .9 9 10 0. 03 99 .9 7 99 .9 9 10 0. 01 99 .9 9 99 .9 6 99 .9 6 t ot al a lk al i 11 .7 2 11 .5 8 10 .7 7 11 .3 4 11 .4 5 11 .2 5 11 .3 4 10 .5 13 .4 3 k 2o /n a 2 o 1. 68 1. 86 4. 03 3. 74 2. 39 2. 26 2 2. 6 2. 07 ss mm pp 11-ee yy 33 tt aa uu --dd aa 3333 22-0044 ss mm pp 11-dd st .d ev . 3366 00-1188 xx rr ff ee dd ss (n =2 0) 62 .0 2 62 .2 6 63 .8 1 63 .4 8 56 .4 5 59 .7 8 0. 73 60 .2 7 0. 35 0. 43 0. 49 0. 31 0. 74 0. 18 0. 11 0. 53 18 .6 6 18 .4 18 .0 7 19 .3 1 15 .4 1 18 .1 0. 36 19 .0 9 3. 2 3. 59 3. 06 2. 94 6. 05 4. 26 0. 3 4. 15 0. 15 0. 11 0. 13 0. 12 0. 06 0. 08 0. 7 0. 93 0. 58 0. 38 4. 83 1. 2 0. 19 0. 16 2. 4 2. 69 1. 83 2. 31 7. 88 3. 8 0. 42 3. 64 4. 2 4. 13 3. 96 3. 12 2. 46 4. 31 0. 19 3. 6 8. 2 7. 47 7. 98 8. 12 5. 74 8. 29 0. 27 8. 52 0. 11 0. 07 0. 33 2. 8 4. 54 4. 21 1. 99 68 28 54 2 23 5 41 26 34 4 55 5 27 7 21 7 22 9 96 27 4 10 63 13 1 48 3 73 5 20 2 56 15 3 5 21 99 .9 9 10 0 99 .9 8 99 .9 7 10 0. 01 10 0 99 .9 6 12 .4 11 .6 11 .9 4 11 .2 4 8. 2 12 .6 12 .1 2 1. 95 1. 81 2. 02 2. 6 2. 33 1. 92 2. 37 t ab le 3 c he m ic al a na ly se s of t he p ro xi m al p yr oc la st ic d ep os its o ld er t ha n 18 .3 k a of t he c am pa ni an a re a an d th e co rr el at ed t ep hr a la ye rs . e d s a na ly se s fo r al l l ac us tr in e an d m ar in e te ph ra la ye rs . a x r f c he m ic al a na ly se s. n = nu m be r of a na ly se d sa m pl es . 33aa )) a review of tephrostratigraphy ... 100 ee rruu pptt iioo nn ss cchh iiaa vvaa aa s t. de v. cc 99 ss mm pp 11-ccaa cc 1133 bb ss mm pp 11-aa aa cc 1144 ss .. ll uucc iiaa aa s t. de v. cc 1155 cc aa 11-aa aa st . d ev . cc 1166 st . d ev . ss cc 22-aa aa st . d ev . cc ((ii)) 66 (n =3 ) (n =8 ) (n =4 ) (n =2 ) s io 2 67 .7 1 0. 41 66 .1 6 60 .7 1 60 .9 8 62 .2 4 63 .1 4 59 .7 4 0. 35 61 .3 5 61 .0 9 1. 14 61 .6 3 0. 93 63 .4 6 0. 36 64 .3 7 t io 2 0. 21 0. 01 0. 24 0. 48 0. 34 0. 47 0. 28 0. 51 0. 03 0. 29 0. 46 0. 05 0. 31 0. 09 0. 53 0 0. 13 a l 2 o 3 16 .4 2 0. 34 17 .8 2 18 .5 4 19 .3 4 19 .2 1 19 .2 18 .6 2 0. 69 19 .1 3 18 .0 7 0. 08 19 .0 9 0. 22 17 .7 8 0. 23 18 .5 5 f e 2 o 3 2. 27 0. 04 1. 98 3. 72 3. 25 3. 84 2. 58 5. 03 0. 25 3. 06 4. 45 0. 59 2. 97 0. 47 3. 86 0. 04 2. 39 m no 0. 14 0 0. 15 0. 24 0. 15 0. 01 0. 14 0 0. 32 0. 01 m go 0. 41 0. 01 0. 04 0. 58 0. 55 0. 56 0. 13 1. 24 0. 14 0. 13 1. 09 0. 18 0. 14 0. 07 0. 51 0. 04 0. 01 c ao 2. 29 0. 07 2. 26 3. 47 2. 52 1. 9 1. 54 3. 40 0. 19 1. 95 3. 07 0. 39 1. 84 0. 29 1. 62 0. 04 1. 56 n a 2 o 3. 79 0. 06 3. 6 3. 55 3. 4 4. 92 5. 76 3. 26 0. 34 6. 52 3. 37 0. 04 6. 27 0. 49 5. 59 0. 06 4. 99 k 2o 6. 73 0. 11 7. 85 8. 73 9. 6 6. 55 7. 34 7. 88 0. 34 7. 53 8. 12 0. 21 7. 72 0. 54 6. 32 0. 1 7. 98 p 2o 5 0. 03 0 0. 06 0. 07 0. 17 0. 02 0. 15 0. 04 0. 04 0 l. o .i. 3. 8 0. 08 3. 54 5. 39 3. 98 0. 61 4. 05 0. 54 4. 56 0. 11 n b 48 3 60 11 4 47 4 48 2 15 7 2 z r 39 3 10 38 5 70 1 32 5 16 33 5 13 10 26 8 y 27 2 35 60 30 3 32 1 99 1 s r 18 9 7 73 6 56 73 6 50 73 0 33 35 13 r b 38 3 8 31 7 35 2 26 1 19 25 9 13 42 7 4 c e 14 7 5 15 8 24 0 15 4 12 15 3 3 46 8 11 b a 92 3 76 8 18 12 03 16 8 10 73 72 34 10 la 90 2 91 13 1 85 8 86 4 25 2 3 n i 4 2 4 4 6 3 5 2 4 1 c r 4 1 4 2 9 4 7 3 3 2 v 17 1 58 17 84 8 68 14 15 1 c o 3 1 5 5 10 1 8 2 5 1 t ot al 10 0 99 .9 5 99 .9 9 99 .9 8 10 0 99 .9 7 10 0 99 .9 6 10 0 99 .9 7 10 0. 01 99 .9 8 t ot al a lk al i 10 .5 3 0. 14 11 .4 5 12 .2 8 13 11 .4 7 13 .1 11 .1 3 0. 64 14 .0 5 11 .4 9 0. 22 13 .9 9 11 .9 1 0. 16 12 .9 7 k 2o /n a 2 o 1. 78 0. 03 2. 18 2. 46 2. 82 1. 33 1. 27 2. 43 0. 18 1. 15 2. 41 0. 06 1. 23 1. 13 0 1. 6 st .d ev . ss aa 33-aa aa cc 1188 ss aa 22-aa aa st .d ev . 6666 66-0044 (n =2 ) (n =2 ) 1. 08 62 .3 61 .3 6 59 .2 4 0. 47 60 .8 0. 13 0. 45 0. 31 0. 66 0 0. 36 0. 07 18 .3 2 18 .9 6 17 .6 4 0. 1 19 .6 4 0. 22 3. 57 3. 17 5. 64 0. 26 3. 09 0. 18 0. 14 0 0. 02 0. 63 0. 32 2 0. 42 0. 09 0. 16 2. 15 2. 78 4. 79 0. 16 2. 59 0. 99 3. 99 3. 4 3. 31 0. 5 4. 93 0. 42 8. 34 9. 68 6. 36 0. 41 8. 47 0. 06 0. 23 0. 03 3. 92 3. 04 0. 21 64 45 7 40 4 33 2 50 41 36 3 39 6 82 6 29 27 6 20 8 11 21 0 16 5 24 14 9 11 58 14 1 11 4 87 20 3 10 5 2 27 27 34 10 6 1 5 13 1 99 .9 9 99 .9 8 10 0 99 .9 7 12 .3 3 13 .0 8 9. 67 0. 08 13 .4 2. 09 2. 85 1. 95 0. 42 1. 72 s eg ue t ab le 3 33bb )) r. sulpizio et al. clastic fall deposits of tau1-e and codola (table 2) respectively, while the widely dispersed y3 tephra layer (keller et al., 1978) has been correlated to the co-ignimbrite deposit smp1-e, dated at 25.82±0.27 ka (tables 2 and 3). the attribution of tephra layer c8 to codola eruption needs some comments. this tephra layer was recognised in cores ket 8004, 8011 and 8218 from tyrrhenian and adriatic seas, and dated at 26.7±0.8 ka (paterne, 1985). anyway, in more recent papers (paterne et al., 1988; paterne & guichard, 1993) c8 101 figure 4 schematic correlation among tephra layers recognised in the marine cores considered in this study. see figure 1 for locations. a review of tephrostratigraphy ... tephra layer is not reported, due to the misleading attribution of tephra layer c10 to the campanian ignimbrite eruption made by paterne et al. (1988) and the following “forced” adjustment of the stratigraphy of core ket 8004 on the basis of a c10 age of 33.5 ka (paterne et al., 1988). indeed, new 14c and 39ar/40ar data aged the terrestrial campanian ignimbrite deposits to about 37-39 ka (deino et al., 1994; de vivo et al., 2001), in agreement with the new correlation of these deposits to tephra layer c13 (dated at about 41 ka; ton-that et al., 2001). on the basis of these evidences the original stratigraphy of core ket 8004 reported by paterne (1985) and age of tephra layer c8 of 26.7±0.8 ka have been considered correct and adopted for the correlation with proximal deposits. similar problems affect also the tephra layers 332-04 and 360-18, which have been correlated to the tau1-d and smp1-d pyroclastic fall deposits. these two tephra layers were dated at about 33.5-33.7 ka (paterne et al., 1988), but these ages must not be considered correct, being influenced by the double error introduced by the correlation of layer c10 to the campanian ignimbrite deposits and to the age of 33.5 ka attributed to its proximal terrestrial deposits (paterne et al., 1988). on the basis of these considerations the original ages of 27.8 and 28.5 ka for tephra layers 332-04 and 36018 (paterne, 1985) have been adopted. moreover, an accurate inspection of chemical and stratigraphic data of c13 tephra layer shows the coexistence of at least two different tephra with similar chemical composition (peralkalic trachyte and trachyte; paterne, 1985; paterne et al., 1988), here labelled c13a and c13b (tables 2 and 3). indeed, only the c13a tephra layer belong to the campanian ignimbrite deposits, while the c13b tephra layer has been correlated to 102 figure 5 schematic correlation among terrestrial deposits and tephra layers recognised in lacustrine and marine cores. dashed lines indicate the lack of tephra layer in lacustrine or marine cores. on the left of the terrestrial record column are shown the deposits from phlegrean fields activity, whereas on the right are shown the deposits of somma-vesuvius (plain text), ischiaprocida (italic text) and etna-eolian islands-palinuro seamount-pantelleria (underlined italic text). the grey dashed box indicates the uncertainties in the age of campanian ignimbrite deposits. r. sulpizio et al. the smp1-c pyroclastic fall deposit, emplaced very close to the campanian ignimbrite eruption (sulpizio et al., 2003). the recognition of smp1-c deposits can also help in the unravelling the discussion about the single or multiple occurrence of campanian ignimbrite(s) (paterne et al., 1988; scandone et al., 1991; narcisi & vezzoli, 1999). as shown for the c2 tephra layer (siani et al., 2003), this is probably due to the clustering of different large explosive eruptions of similar chemical composition occurred in a relatively short time span, which frequently results in a thick, single, marine tephra layer. the correlation of tephra layer c9 (dated at 36 ka; paterne & guichard, 1993) to the schiava eruption is supported by the most evolved chemical composition in the whole set of data shown by both deposits (table 3), while tephra layer c14 has been correlated to the smp1-a pyroclastic fall deposit (tables 2 and 3). the c15-c18 tephra layers were grouped in the green tuff series by paterne et al. (1988), and attributed to the activity of the ischia island. indeed, only the tephra layer c17 can be correlated to the green tuff eruption of ischia, while the other tephra layer have been correlated to terrestrial proximal deposits on the basis of chronology, lithology and chemical composition (tables 2 and 3). among them the only tephra layer correlable to ischia activity is the c(i)6, dated at 57 ka (paterne et al., 1988), which correspond to the sc2-a pyroclastic fall deposit (tables 2 and 3). the other tephra layers of the green tuff series have been correlated to the explosive activity of phlegrean fields (table 2; sulpizio et al., 2003). in particular, c15 tephra layer has been correlated to the large explosive eruption of s. lucia, dated at 47.5±2.6 ka (sulpizio et al., 2003; table 2), while c16 tephra layer has a terrestrial counterpart in the ca1-a pyroclastic fall deposit (tables 2 and 3). tephra layer c18 appear very widespread in the central mediterranean cores, and correspond to the tephra layer 003 from odp leg 107-site 650 (calanchi et al., 1994), and to the tephra layer y7 (keller et al., 1978). it has an interpolated age of 60.3 ka (paterne et al., 1988; paterne & guichard, 1993) and corresponds to the terrestrial proximal deposit sa3-b (tables 2 and 3). finally, the oldest tephra layer correlated to a terrestrial counterpart is 666-04, dated at 62.3 ka by paterne et al. (1988), which corresponds to sa2 pyroclastic fall deposit (tables 2 and 3). ccoorrrreellaattiioonnss aammoonngg ddiiffffeerreenntt pprrooxxiieess figure 5 shows a schematic correlation among terrestrial, lacustrine and marine proxies. it represents an up-to-date, detailed chronostratigraphic scheme of the last 65 ka, useful for the correlation of different archives in the mediterranean region. seventeen tephra layers were correlated in the last 20 ka among the three proxies, while two tephra layers (ap1-2) were correlated between proximal terrestrial and lacustrine proxies. most of them are concentrated in the <4.5 ka and in the 10.5-20 ka time spans, with the occurrence of only two tephra layers (mercato and e1 tephra layers) in the 4.510.5 ka (fig. 5). other sixteen tephra layers were correlated in the 20-63 ka time span among terrestrial, marine and lacustrine proxies. a cluster of five tephra layers occurs between 24-27 ka, whereas ten tephra layers, almost regularly spaced, characterise the >35 ka time span (fig. 5). moreover, sources from neapolitan volcanoes dominated throughout the whole succession, with the occurrence of only two eolian (e1/gabellottofiumebianco and e2/pollara; paterne et al., 1988; calanchi et al., 1993; siani et al., 2001; 2003) and etnean (y1/et1/biancavilla ign.; keller et al., 1978; paterne et al., 1988) tephra. on the basis of the proposed correlations the dispersal areas of several of these tephra layers can be traced (figs. 6 and 7). these areas, even broadly defined and strongly dependent on the recognition of tephra in the marine and lacustrine cores, are generally in agreement with the main direction of dispersal of fall deposits of several well-known eruptions from sommavesuvius and phlegrean fields, such as ad 79, avellino, agnano m. spina, mercato, agnano p.p., greenish, pomici di base, tau1-e and s. lucia (figs. 6 and 7). in some cases, the dispersal areas indicate in figures 6 and 7 comprise sites (i.e. cores) where the tephra layer has not been recognised. several causes can account for this lack of recognition, such as settling of the marine tephra as multiparticle aggregates (carey, 1997), erosion due to bottom currents or coring process. on the other hand, pyroclastic fall deposits are frequently dispersed along a defined dispersal axis and the isopach maps enclose ellipse-shaped areas, even if changes in dispersal axis is possible in very distal areas (cas and wright, 1987). in this way, in figures 6 and 7 we traced the indicative dispersal areas on the basis of proximal isopachs, irrespective of the presence or not of the tephra layer in all the cores enclosed. instead, broader and irregular dispersions characterise the tephra layers correlated to single (i.e. campanian ignimbrite) or clusters (biancavilla, nyt) ignimbrite-forming eruptions (fig. 6 and 7), due to the different eruptive dynamic and dispersal of volcanic clouds not linked to large convective columns (cas and wright, 1987). ccoonncclluuddiinngg rreemmaarrkkss the proposed correlations highlights only part of the tephra layer record reported for the central mediterranean region (i.e. keller et al., 1978; paterne et al., 1988; vezzoli, 1991; narcisi, 1996; calanchi et al., 1998; wulf et al., 2001), but more work is necessary to reach a comprehensive correlation among terrestrial, lacustrine and marine records. the correlations proposed in this work, although being as comprehensive as possible, intend to be preliminary. indeed, it is only of transitory usefulness, because the knowledge of past activity for some italian volcanoes is in tumultuous growth and in the near future new data will be available. in particular, the knowledge of stratigraphy and chronology of tephra layers older than 18 ka of centralsouthern italy need to be supported by extensive studies on terrestrial records near volcanic centres. specific studies should be addressed in this direction and it should be a specific task since active volcanoes are often studied only in respect to recent activity for the obvious purpose of hazard assessment. 103a review of tephrostratigraphy ... 104 66)) r. sulpizio et al. 105 figure 6 and 7 maps showing selected dispersal areas inferred from the recognition of tephra layers in lacustrine and marine cores. for deposits from sustained columns (fall deposits) the dispersal area has been traced using an ellipse with the same eccentricity of the proximal isopachs and delimited with a dashed line. the dashed areas in the avellino, agnano p.p. and s. lucia maps indicate secondary lobes of dispersion of tephra. for co-ignimbrite deposit (neapolitan yellow tuffs, biancavilla ignimbrites and campanian ignimbrite) and for the gabellotto-fiumebianco eruption the shaded area indicates the present day limit of recognition of the respective tephra layers. proximal isopach maps from: ad 79-sigurdsson et al. (1985); avellino-cioni et al. (2000); agnano m. spina-de vita et al. (1999); mercato-santacroce (1987); agnano p.p.-rosi & sbrana (1987); greenish-cioni et al. (2003b); pomici di base-bertagnini et al. (1998); tau1-e-sulpizio et al. (2003); campanian ignimbrite-cornell et al. (1983); s. lucia-sulpizio et al. (2003). 77)) a review of tephrostratigraphy ... l'eruzione vesuviana delle “pomici di avellino” e la facies di palma campania (bronzo antico). territorio storico e ambiente 2. centro universitario europeo per i beni culturali, ravello, 61-82. edipuglia, bari. cioni r., levi s. & sulpizio r. (2000) apulian bronze age pottery as a long distance indicator of the avellino pumice eruption (vesuvius, italy). in mcguire w.g., griffiths d. & stewart i (eds): the archaeology of the geological catastrophes. geol. soc. special publications , 171, 159-177, cioni r, longo a, macedonio g, santacroce r, sbrana a., sulpizio r. & andronico d. (2003a) assessing pyroclastic fall hazard through field data and numerical simulations: the example from vesuvius. j. geophys. res. 110088, doi:10.1029/2001 jb000642. cioni r., sulpizio r. & garruccio n. (2003b) variability of eruption dynamic during a subplinian event: the greenish pumice of somma-vesuvius (italy). j. volcanol. geotherm. res. 124, 89-114. civetta l., cornette y., crisci g., gillot p.y., orsi g. & requiejo c.s. (1984) geology, geochronology and chemical evolution of the island of pantelleria. geol. mag. 112211, 541-668 coltell i m., del carlo p. & vezzoli l. (2000) stratigraphic constraints for explosive activity in the past 100 ka at etna volcano, italy. int. j. earth sciences. 8899, 665-677. cornell w., carey s. & sigurdsson h. (1983) computer simulation of transport and deposition of the campanian y-5 ash. j. volcanol. geotherm. res. 1177, 89-109. crisci g.m., de francesco a.m., mazzuoli r., poli g. & stanzione d. (1989) geochemistry of recent volcanics of ischia island, italy: evidences of crystallization and magma mixing. chem. geol. 7788, 15-33. crisci g.m., de rosa r., esperanca s., mazzuoli r. & sonnino m. (1991) temporal evolution of a three component system: the island of lipari (aeolian arc, southern italy). bull. volcanol. 5533, 207-221. de astis g., la volpe l., peccerillo a. & civetta l. (1997) volcanological and petrological evolution of vulcano island (aeolian arc, southern tyrrhenian sea). j. geophys. res. b4, 110022, 80218050. de rita d., frazzetta g. & romano r. (1991) the biancavilla-montalto ignimbrite (etna, sicily). bull. volcanol. 5533, 121-131. de vivo b., rolandi g., gans a., calvert a., bohrson w.a., spera f.j. & belkin h.e. (2001) new constraints on the pyroclastic eruptive history of the campanian volcanic plain (italy). mineralogy and petrology. 7733, 47-65. deino a.l., courtis g.h., southon j., terrasi f., campajola l. & orsi g. (1994) 14c and 39ar/40ar dating of the campanian ignimbrite, phlegrean fields, italy. icog., berkeley, ca, p. 77 (abstract). de vita s., orsi g., civetta l., carandente a., d'antonio m., deino a., di cesare t., di vito m.a., fisher r.v., isaia r., marotta e., necco a., ort m., pappalardo l., piochi l. & southon j. (1999) the agnano-monte spina eruption (4100 years bp) in the restless campi flegrei (italy). in orsi g., civetta l. & valentine g.a. (eds): volcanism in the 106 rreeffeerreenncceess andronico d. (1997) la stratigrafia dei prodotti dell’eruzione di lagno amendolare, campi flegrei, napoli. atti soc. toscana sci. nat. pisa mem., serie a, 110044, 165-178. andronico d. & cioni r. (2002) contrasting styles of mt. vesuvius activity in the period between avellino and pompeii plinian eruptions, and some implications for assessments of future hazards. bull. volcanol., 6644, 372-391. andronico d., calderoni g., cioni r., sbrana a., sulpizio r. & santacroce r. (1995) geological map of somma vesuvius volcano. per. mineral., 6644, 77-78. andronico d., cioni r., marianelli p., santacroce r., sbrana a. & sulpizio r. (1996) introduction to somma-vesuvius. in santacroce r., rosi m., sbrana a., cioni r. & civetta l. (eds): vesuvius decade volcano workshop handbook, september 17-22, p. 1-13, naples. bard e., arnold m., mangerud j., paterne m., labeyrie l., duprat j., mélières m., sonstegaard e. & duplessy j.c. (1994) the north atlantic atmosphere-sea surface 14c gradient during the younger dryas climatic event. earth. planet. sci. letts. 112266, 275-287. bertagnini a., landi p., rosi m. & vigliargio a. (1998) the pomici di base plinian eruption of sommavesuvius. j. volcanol. geotherm. res. 8833, 219239. calanchi n., de rosa r., mazzuoli r., rossi p. & santacroce r. (1993) silicic magma entering a basaltic magma chamber: eruptive dynamics and magma mixing-an example from salina (aeolian islands, southern tyrrhenian sea). bull. volcanol. 5555, 504-522. calanchi n., gasparotto g. & romagnoli c. (1994) glass chemistry in volcaniclastic sediments of odp leg 107, site 650, sedimentary sequence: provenance and chronological implications. j. volcanol. geotherm. res. 6600, 59-85. calanchi n., dinelli e., lucchini f. & mordenti a. (1996a) chemostratigraphy of the late quaternary sediments from lake albano and central adriatic sea cores (paliclas project). mem. ist. ital. idrobiol. 5555, 247-263. calanchi n., dinelli e., gasparotto g. & lucchini f. (1996b) etnean tephra layer in albano lake and adriatic sea cores: new findings of y-1 layer in the central mediterranean area. acta vulcanologica. 88, 7-13. calanchi n., cattaneo a., dinelli e., gasparotto g. & lucchini f. (1998) tephra layers in late quaternary sediments of the central adriatic sea. mar. geol. 114499, 191-209. carey s. (1997) influence of convective sedimentation on the formation of widespread tephra fall layers in the deep sea. geology. 99, 839-842. cas r. & wright j.w. (1987) volcanic successions: modern and ancient. allen and unwin, london, 528 pp. cioni r., morandi d., sbrana a. & sulpizio r. (1995) l'eruzione delle pomici di avellino: aspetti stratigrafici e vulcanologici. in albore livadie c. (ed): r. sulpizio et al. campi flegrei. j. volcanol. geotherm res. 91, p. 269-301. di girolamo p. & stanzione d. (1973) lineamenti geologici e petrologici dell’isola di procida. rendic. soc. it. min. petr, 81-125. di vito m.a., isaia r., orsi g., southon j., de vita s., d’antonio m., pappalardo l. & piochi m. (1999) volcanism and deformation since 12,000 years at the campi flegrei caldera (italy). j. volcanol. geotherm. res. 9911: 221-246. fontugne m., paterne m., calvert s.e., murat a., guichard f. & arnold m. (1989) adriatic deep water formation during the holocene: implication for the reoxygenation of the deep eastern mediterranean sea. paleoceanography. 44, 199206 frazzetta g., la volpe l. & sheridan m. (1983) evolution of the fossa cone, vulcano. j. volcanol. geotherm. res. 1177: 329-360 gillot p.y. (1984) datations par la methode du potassium-argon des roches volcaniques récentes (pleistocene et holocene). contribution à l'étude chronostratigraphique et magmatique des provinces volcaniques de campanie, des îles eoliennes, de pantelleria (italie du sud) et de la reunion (océan indien). thèse dr sc paris sud: 249 pp gioncada a., mazzuoli r., bisson m. & pareschi m.t. (2003) petrology of volcanic products younger than 42 ka on the lipari-vulcano complex (aeolian islands, italy): an example of volcanism controlled by tectonics. j. volcanol. geotherm. res. 112222, 191-220. kallel n., paterne m., labeyrie l., duplessy j.c. & arnold m. (1997) temperature and salinity records of the tyrrhenian sea during the last 18,000 years. palaeogeogr. palaeoloclimatol. palaeoecol. 8844, 191-215. keller j., ryan w.b.f., ninkovich d. & altherr r. (1978) explosive volcanic activity in the mediterranean over the past 200,000 yr as recorded in deep-sea sediments. geol. soc. am. bull. 8899, 591-604 keller j. (1980) the island of salina. rend. soc. ital. mineral. petrol. 3366, 489-524 kennet j. (1982) marine tephrochronology. in: emiliani e. (ed): the sea. wiley and sons, 1373-1436 kieffer g. (1979) l'activité de l'etna pendant les dernières 20 000 ans. c. r. acad. sci. paris. 228800dd, 1023-1026 jahns s. & van den boogard c. (1998) new palynological and tephrostratigraphical investigations of two salt lagoons on the island of mljet, south dalmatia, croatia. veget. hist. archaeobot. 77, 219-234. mahood g.a., & hildreth w. (1986) geology of the peralkaline volcano at pantelleria, strait of sicily. bull. volcanol. 4488, 143-172. mangerud j., lie s.e., furnes h., kristiansen i.l. & lomo a. (1984) a younger dryas ash bed in western norway and its possible correlations with tephra in cores from the norwegian sea and the north atlantic. quat. res. 2211, 85-104. mccoy f. & cornell w. (1990) volcaniclastic sediments in the tyrrhenian basin. in: kastens k.a., mascle j. et al. (eds): proc. odp. sci. results, 107, 291305. college station, tx ocean drilling program. narcisi b. (1993) segnalazione di un livello piroclastico di provenienza etnea nell'area del fucino (italia centrale). il quaternario. 66, 87-92. narcisi b. (1996) tephrochronology of a late quaternary lacustrine record from the monticchio maar (vulture volcano, southern italy). quat. sci. rev. 1155, 155-165 narcisi b. (1999a) neapolitan yellow tuff tephra in the lacustrine sediments of the valle di castiglione crater (alban hills). acta vulcanologica. 1111, 265269. narcisi b. (1999b) nuovi ritrovamenti del tephra tardiglaciale etneo in italia centrale. il quaternario. 1122, 69-78. narcisi b. & vezzoli l. (1999) quaternary stratigraphy of distal tephra layers in the mediterranean-an overview. global planet. change. 2211, 31-50. norin e. (1958) the sediments of the tyrrhenian sea. swedish deep-sea exped. repts., 1947-1948. 88, 4-136. orsi g., ruvo l. & scarpati c. (1991) the recent explosive volcanism at pantelleria. geol. rundschau. 8800, 187-200. orsi g., de vita s. & di vito m. (1996a) the restless, resurgent campi flegrei nested caldera (italy): constraints on its evolution and configuration. j. volcanol. geotherm. res. 7744, 179-214. orsi g., piochi m., campajola l., d’onofrio a., gialanella l. & terrasi f. (1996b) 14c geochronological constraints for the volcanic history of the island of ischia (italy) over the last 5000 years. j. volcanol. geotherm. res. 7711, 249-257. pappalardo l., civetta l., d’antonio m., deino a., di vito m., orsi g., caradente a., de vita s., isaia r. & piochi m. (1999) chemical and sr-isotopical evolution of the phlegrean magmatic system before the campanian ignimbrite and the neapolitan yellow tuff eruptions. j. volcanol. geotherm. res. 9911, 179-214. paterne m. (1985) reconstruction de l'activitè explosive des volcans de l'italie du sud par tèphrochronologie marine. thèse dr. sciences paris sud, 144 pp. paterne m., guichard f., labeyrie j., gillot p.y. & duplessy j.c. (1986) tyrrhenian sea tephrachronology of the oxygen isotope record for the past 60 000 years. mar. geol. 7722: 259-285. paterne m., guichard f. & labeyrie j. (1988) explosive activity of the south italian volcanoes during the past 80 000 years as determined by marine tephrochronology. j. volcanol. geotherm. res. 3344, 153-172. paterne m., labeyrie j., guichard f., mazaud a. & maitre f. (1990) fluctuation of the campanian explosive activity (south italy) during the past 190,000 years, as determined by marine tephrochronology. earth planet. sci. letts. 9988, 166-174 paterne m. & guichard f. (1993) triggering of volcanic pulses in the campania area, south italy, by periodic deep magma influx. j. geophys. res. 9988, 1861-1873. pescatore t., rolandi g. (1981) osservazioni preliminari sulla stratigrafia dei depositi vulcanoclastici nel settore sw dei campi flegrei. boll. soc. geol. it. 110000, 233-254. pichler h. (1980) the island of lipari. rend. soc. ital. mineral. petrol. 3366, 415-440. 107a review of tephrostratigraphy ... poli s., chiesa s., gillot p.y. & guichard f. (1987) chemistry versus time in the volcanic complex of ischia (gulf of naples, italy): evidence of successive magmatic cycles. contrib. mineral. petrol. 9955, 322-335. ramrath a., zolitschka b., wulf s. & negendank j.f.w. (1999) late pleistocene climatic variations as recorded in two italian maar lakes (lago di mezzano, lago grande di monticchio). quat. sc. rev. 1188, 977-992. rosi m. & sbrana a., eds. (1987) phlegraean fields. cnr quad. ric. sci. 111144 ((88)), 175 santacroce r., ed. (1987) somma-vesuvius. cnr quad. ric. sci. 111144((99)) 230. scandone r., bellucci f., lirer l. & rolandi g. (1991) the structure of the campanian plain and the activity of the neapolitan volcanoes (italy). j. volcanol. geotherm. res. 4488, 1-31. siani g. (1999) estimation de l'âge 14c du réservoir des eaux de surface de la méditerranée pendant les derniers 18 000 ans. relations avec la circulation océanique. thèse, université de paris-sud orsay. 171. siani g., paterne m., michel e., sulpizio r., sbrana a., arnold m. & haddad g. (2001) sea-surface radiocarbon reservoir age changes since the last glacial maximum. science. 229944, 1917-1920. siani g., sulpizio r., paterne m. & sbrana a. (2003) detailed tephrochronology for the last 18,000 years in the south adriatic deep-sea sediments: correlations with terrestrial deposits. quat. sc. rev. submitted. sigurdsson h., carey s., cornell w. & pescatore t. (1985) the eruption of vesuvius in a.d. 79. national geographic research. 11 (3), 332-387. sparks r.j.s. & huang t.c. (1980) the volcanological significance of deep-sea ash layers associated with ignimbrites. geol. magaz. 111177, 425-436. sulpizio r., zanchetta g. & di vito m.a. (2003) the late pleistocene pyroclastic deposits of the southern campanian plain: insights on their sources and relationships with tephrostratigraphy. int. journ. earth sc. submitted ton-that t., singer b. & paterne m. (2001) 40ar/39ar dating of latest pleistocene (41 ka) marine tephra in the mediterranean sea: implications for global climate records. earth planet. sci. letts. 118844, 645658. vezzoli l. (1988) island of ischia. cnr quad. ric. sci. 111144((1100)), 230. vezzoli l. (1991) -tephra layers in bannock basin (eastern mediterranean). mar. geol. 110000, 21-34. watts w.a., allen. j. r.m. & huntley b. (1996) vegetation history and climate of the lastglacial period at laghi di monticchio, southern italy. quat. sc. rev. 1155, 133-153. wulf s. (2000) das tephrochronologische referenzprofil des lago grande di monticchio. phd thesis. universitat potsdam. in german. wulf s., brauer a., frank u., mingram j. & negendank j.f.w. (2001) detailed stratigraphy of the italian explosive volcanism in sediments of lago grande di monticchio. cities on volcanoes 2, auckland, new zealand, february 22-26th, 2001. poster with abstract. zanchetta g., di vito m., fallick a.e. & sulpizio r. (2000) stable isotopes of pedogenic carbonate from somma-vesuvius area, southern italy, over the last 18 ka: palaeoclimatic implications. j. quat. sc. 1155, 813-824. 108 ms. ricevuto il 20 novembre 2002 testo definitivo ricevuto il 3 giugno 2003 ms. received: november 20, 2002 final text received: june 3, 2003 r. sulpizio et al. imp.bertoldi& new data from northern apennines (italy) pollen sequences spanning the last 30,000 yrs remo bertoldi 1, alessandro chelli 2, rachele roma 1 & claudio tellini 2* 1 dipartimento di biologia evolutiva e funzionale, università degli studi di parma, parma, italy 2 dipartimento di scienze della terra, università degli studi di parma, parma, italy * corresponding author: c. tellini, dipartimento di scienze della terra, università di parma, viale g. usberti, 157/a, 43100 parma, italy. e-mail: claudio.tellini@unipr.it abstract: bertoldi r., chelli a., roma r. & tellini c., new data from northern apennines (italy) pollen sequences spanning the last 30,000 yrs. (it issn 0394-3356, 2007). palynological analyses and radiocarbon dates were performed on lacustrine sequences from the two sites of berceto (820 m a.s.l.) and lagdei (1,254 m a.s.l.) in parma province (northern italy). this work allowed us to obtain new data and constrains about vegetational and climatic history of the northern apennines from upper pleistocene to lower holocene. the berceto core provided a long pollen sequence from the pleniglacial to the lateglacial. in it the oscillations of the percentage of picea and of the concentration values of ap, allow us to highlight a succession of stadials and interstadials. the correlation among three climatic amelioration periods found in the berceto pollen sequence and the interstadials tursac, laugerie and lauscaux was discussed. the lagdei lacustrine sequence, already studied by one of us in the 1980, was newly cored and analyzed in its portion tributable to the lateglacial and postglacial. the results from pollen analyses and radiocarbon dates allowed us to establish that bertoldi interpretation, questioned by lowe, was correct and to reconstruct the vegetation characters at the lateglacial/postglacial boundary for the northern apennines. riassunto: bertoldi r., chelli a., roma r. & tellini c., nuovi dati da sequenze polliniche degli ultimi 30.000 anni nell’appennino settentrionale (italia). (it issn 0394-3356, 2007). sono state condotte analisi palinologiche, corredate da datazioni assolute 14c, in due depositi lacustri dell’appennino parmense nell’ambito di più vaste ricerche glaciologiche-geomorfologiche in questo settore dell’appennino settentrionale. scopo di questo lavoro è la ricostruzione della storia vegetazionale e climatica dell’appennino settentrionale nell’intervallo pleistocene superiore – olocene inferiore che finora appare ancora ampiamente lacunosa. infatti mentre sono numerosi gli studi pollinici in piccole conche palustro-lacustri di età olocenica, soltanto due profili pollinici (lagdei e prato spilla) svelano episodi di età tardoglaciale. nessun dato pollinico e/o cronologico è invece disponibile finora per il pleniglaciale. la successione lacustre del deposito di berceto (820 m s.l.m.) ha fornito una lunga sequenza pollinica appartenente al pleniglaciale ed in parte al tardoglaciale. questa successione vegetazionale è troncata alla sommità da una grossa lacuna sedimentaria che delimita alcuni eventi riferibili al postglaciale inferiore. la sequenza pollinica pleniglaciale permette di intravedere episodi stadiali e interstadiali, sulla base delle oscillazioni dei valori percentuali di picea e dei valori delle concentrazioni ap. le fasi stadiali sono caratterizzate da formazioni steppiche con pinus, mentre quelle interstadiali da formazioni aperte a pinus con presenza di picea. tentativamente le tre fasi di miglioramento climatico del pleniglaciale sono correlate (messe in relazione) con gli interstadiali di tursac, laugerie e lauscaux. il limite pleniglaciale/tardoglaciale sembra chiaramente espresso ed appare un po’ più antico di 14.480 ± 50 14c bp. la sequenza tardoglaciale di berceto è troncata al livello di m 6,20 datato 11.150 ± 70 14c bp. il deposito lacustre di lagdei, alta val parma (1254 m s.l.m.), già studiato nel 1980 da uno di noi, ma allora non corredato da datazioni assolute, è stato nuovamente sondato e studiato nella sua porzione tardoglaciale e postglaciale (lagdei-ii) con il supporto di datazioni radiometriche. scopo principale era quello di individuare nella sequenza il limite tardoglaciale /postglaciale e quindi di ordinare nel tempo gli eventi vegetazionali del tardoglaciale, che erano stati contestati e reinterpretati da lowe. i risultati pollinici e cronologici della sequenza di lagdei-ii confermano in pieno l’originaria interpretazione della sequenza pollinica fatta da bertoldi nel 1980. in particolare è stato stabilito definitivamente il limite tardoglaciale/postglaciale al limite tra le z.p. c e d, limite che coincide con il passaggio fra sedimenti inorganici ed organici e che risulta collocato 15/20 cm sotto al livello datato 9.900 ± 80 14c bp. e’ stato così possibile seguire nel tempo l’evoluzione vegetazionale stadiale/interstadiale durante l’intero tardoglaciale nell’appennino settentrionale. keywords: pleniglacial, lateglacial, palynology, palaeoclimate, italy. parole chiave: : pleniglaciale, tardoglaciale, palinologia, paleoclima, italia. il quaternario italian journal of quaternary sciences 20(1), 2007 3-20 1. introduction the sector of the northern apennines (northern italy) among liguria, emilia and tuscany is between 45° 05’n and 43° 30’n and between 8° 39’e and 12° 22’e. it reaches the maximum altitude in correspondence of mt. cimone (2,165 m) (fig. 1). severe geomorphological processes acted in the northern apennines in the late quaternary, during which at least two glacial episodes occurred (losacco, 1949; federici, 1977). glacial landforms (i.e.: cirques, troughs, moraines) and deposits (i.e.: till and lacustrine sequences) are well represented in several areas, such as in the parma and enza valleys, at elevations ranging from 750 to 1,800 m a.s.l. many palustrine and lacustrine deposits in this area were extensively studied by means of pollen analyses, in order to reconstruct the vegetational history and environmental changes which occurred. unfortunately, only occasionally the pollen analyses were supported by radiocarbon datings (chiarugi, 1936; ferrarini, 1962; braggio morucchio et al., 1978; 4 r. bertoldi et al. figure 1 geographic sketch map of the area (a) and of the sites considered in the text (b). inquadramento geografico dell’area (a) e delle località considerate nel testo (b). bertoldi, 1980; gentile et al., 1988; cruise, 1990; lowe, 1992; lowe & watson 1993; montanari et al., 1994; watson, 1996), and only for two sequences,(1) at lagdei, in the parma valley (bertoldi, 1980) and (2) at prato spilla, in the enza valley (lowe, 1992) (fig.1) was demonstrated a lateglacial age (no more than 13,000 14c yr bp) for the deepest parts of the deposits. in reality, at lagdei a pollen record was detected that can be confidently referred to early upper pleistocene (bertoldi, 1980), but the lack of radiocarbon datings did not allow its sure chronological attribution. at present, no pollen sequences and/or radiocarbon datings are available in this area for the pleniglacial. therefore, one of the problems in the palaeoenvironmental studies in the northern apennines, is the lack of palaeoclimatic records corresponding to the time interval from the last glacial maximum to lateglacial, a crucial time for the environmental changes. in this paper we present the results of pollen analyses and radiocarbon datings performed on a lacustrine sequence found in correspondence to the berceto village (parma province), located not far from the site of lagdei, containing the lgm and the transition to the lateglacial. moreover, we present a new pollen diagram from the sequence of the lagdei site, this time supported by radiocarbon datings. on the whole, the pollen data and radiocarbon dates from the two sequences allow us to illustrate, for the first time, the vegetational and floristic features of the pleniglacial in the northern apennines and to investigate the boundary pleniglacial/lateglacial. moreover, more detailed issues are provided on the vegetational and climatic events that took place during the lateglacial-early postglacial time. 2. the studied sites 2.1 the berceto site the berceto village lies at 820 m a.s.l., close to the divide between the baganza torrent and manubiola torrent, the latter a tributary of the taro river (fig. 1). the geological setting of the berceto area, where three different ligurian tectonic units outcrop (servizio geol. it., 2002), is characterized by a south-verging recumbent anticline that develops within sandstones (arenarie di scabiazza formation). the rocks underlying the sandstones are mainly shaly rocks (argille a palombini di monte rizzone formation and the so-called complesso ofiolitico) (bertoldi et al., 2004). berceto is at the top of a westward-trending slope that experienced many landslide events of different types and sizes. a shallow hollow, lengthened nnessw and with an extension of about 30x103 m2, is in the area between the village and the divide. it is the morphological expression of the trench linked to a rotational landslide that involves the large part of the top of the berceto slope. 2.2 lithostratigraphy of the berceto core the lacustrine sequence found in berceto is 25 meters long and represents about 50% of the total length of a core (fig. 2) collected from a borehole drilled in the centre of the trench due to the landslide. lithostratigraphic analyses were performed on the 5new data from northern apennines ... deposit. in particular, optical microscopy on polished thin-sections yielded information on the sediments fabric and structure; petrographic and mineralogical investigations were also accomplished by means of sem analyses. here we present the main highlights on the berceto sequence and the more exhaustive description is available in bertoldi et al. (2004). the sequence represents the infill of the landslide trench and, from the bottom to the top, the sequence was subdivided into 6 lithological units. the borehole encountered the bedrock at the depth of 48.00 m, represented by argille a palombini di monte rizzone, while from 48.00 to 31.00 m (unit 6, fig. 2) a breccia made up of clasts with silty matrix appeared. the first unit of the lacustrine sequence extends from 31.00 to 17.00 m depth (unit 5, fig. 2). generally, it is composed by light grey silty graded laminae, from 1 to 3 mm thick, and submillimetric dark clayey organic laminae. in detail, the graded laminae are fining upward and show a grey-yellowish lower portion gradually changing pale grey. sometimes, whitish (pale) very thin laminae are put together with the clayey dark organic ones. the pale laminae contain dolomite and mixed layers of clay minerals (illite/smectite). the laminae are folded and affected by shear surfaces. the clastic graded laminae are short repeated sedimentary events. they may represent either flows which occurred from the banks of the lake or the sediment influx from its catchment area. in reality, the lake did not have a tributary but the main source for the water was, likely, the surface runoff that occurred in its surrounding area. the dark and pale laminae were produced by precipitation and flocculation of clay-rich material, during periods characterized by the lack of coarse clastic inputs. between 17.00 and 9.20 m depth (unit 4, fig. 2) a grey-yellowish silt exists that contains levels with pale and dark laminae, deformed in a ductile way and, locally, very fine sands with scattered plant scraps and wood fragments appear. the pale and dark laminae are vague, even if they are still visible. from 9.20 to 6.10 m depth (unit 3, fig. 2), a massive package occurs of light grey fine silty sand. there are intraclasts that vary in colour from lightto dark grey and, locally (especially between 9.20 m and 9.12 m depth), thin levels with plant remains. within this unit the deformation is high, the formerly laminated structures are almost completely destroyed and the material is rather homogeneous. in general, as stated by bertoldi et al. (2004), the whole lacustrine sequence shows, from the bottom to the top, a rising deformation linked to small shackings, as testified by the coherence of the sequence, due to the landslide movements. the features of different units show that the landslide events occurred after the deposition of the unit 5 and they were recorded by each unit in different ways, probably regarding their depth below the bottom of the ancient lake. in the units 4 and 3 the events occurred just after their deposition, when they were still very close to the bottom of the lake and to the water, whereas the unit 5 was affected by folding and shearing when it was already covered by overlying sediments and far from the water. the unit 2 (fig. 2) from 6.10 to 4.30 m depth, 6 represents the definitive infill of the berceto lacustrine basin. the unit starts with a thin layer of sand, gradually replaced upwards by a thick layer of poorly preserved peat, as emphasized by the content of sporomorph that is dominated by oxidized and broken specimens. the bad conservation of peat suggests that it underwent events of pervasive reworking. from 4.30 m depth to 0 m (unit 1, fig. 2) a chaotic breccia made up of poligenic clasts (limestones, sandstones, ophiolithes, etc.) of different sizes and a silty-clay matrix exists. 2.3 the lagdei site: features and previous works the lagdei site is located in the high parma valley at about 1,254 m a.s.l., 12 km south of berceto (fig. 1). around the lagdei site, a mainly arenaceous succession (macigno formation, tuscan nappe) that is made up of thick to very thick turbiditic units, is widely exposed. from a geomorphological point of view, relict glacial landforms and deposits prevail. the evolution of the confluent parma valley glacier, after its maximum in correspondence of the lgm (equilibrium line altitude-ela 1,260 m a.s.l. and glacier front at 730 m a.s.l.), was the topic of an article written by federici & tellini (1983). they recognized at least three stages during the retreat of the glacier. the ela of the first stage reached about 1,370 m a.s.l., with an increase of about 110 metres as regards the lgm. in correspondence of the second stage (ela 1,530 m a.s.l.) the parma valley was characterized by three distinct glaciers, each one confined within one of the three main deep valleys representing the high parma torrent basin. at that time, the overdeepened hollow of lagdei was free from the ice and the sediment deposition started. during the third stage, the ela exceeded the medium altitude of the divide of the northern apennines and only very small glaciers were within the cirques or snowfields which existed on the slopes with a northern aspect. federici & tellini (1983) correlated, by means of the increases of the equilibrium line altitude (ela), the glacial stages of the parma valley with the classic ones of the alps and they put the third stage in correspondence to the younger dryas. nowadays, a marsh in the middle of the lagdei site exists and it represents the closure of the deposit that filled the overdeepened glacial hollow. pollen analyses on the lagdei sequence began in the early 1980s, when a 12.60 m borehole was handdrilled in the centre of the deposit and analyzed for its pollen contents (bertoldi, 1980). the pollen record indicates that the upper segment (i.e., from the top of the core down to 8.80 m depth) represents the holocene. a good correlation was found between this interval and the coeval pollen records previously identified in the northern apennines (chiarugi, 1936; ferrarini, 1962; braggio morucchio et al., 1978). also the middle part of the core (between 9.85 and 8.80 m depth) provided a well preserved pollen record. because of the lack of radiocarbon datings, the chronostratigraphic interpretation of this interval was achieved by comparison with the better age-constrained vegetational sequences from the southern alps (zoller, 1960; beug, 1964; sercelj, 1966; bertoldi, 1968; beaulieu de & jorda, 1977; behre, 1967; schneider, 1978), which suggested that the middle part of the lagdei sequence is lateglacial in age. this finding was especially important, because for the first time a complete pollen record straddling the lateglacial was found in the northern apennines. in the basal portion of the core (from 12.60 to 10.00 m depth), further vegetational events were recognized, but their age still remains unkfigure 2 lithological features of berceto and lagdei-ii boreholes. litostratigrafia dei carotaggi di berceto e di lagdei-ii. r. bertoldi et al. 7 nown. a new core (“lagdei-ii” core hereafter) was recovered in 1994 with the specific purpose of collecting material suitable for radiocarbon datings, thus providing better age control for the lagdei pollen record. the lagdei-ii borehole was drilled at the southern margin of the lagdei lacustrine area. a continuous and undisturbed core, approx. 15.00 m long, was recovered and can be subdivided into 7 lithostratigraphic units (fig. 2) that are synthetically described. from the top to the bottom of the sequence, after 0.90 m of reworked filling there are: the unit between 0.90 and 2.40 m depth: an alluvial fan deposit characterized by gravels with silty-sandy matrix. the unit between 2.40 and 6.70 m depth: represented by a well-preserved peat layer that contains a fine sandy inorganic fraction. from 6.70 to 7.00 m depth: grey to greenish sandy silt. the unit between 7.00 and 7.30 m depth: made of medium to coarse silty sand, that ranges in color from grey to greenish. from 7.30 to 8.30 m depth: yellowish sandy silt with layers made of silty sand. the unit from 8.30 m to the bottom of the core: a diamict made of clasts of variable size and a sandy-silty matrix. this unit is interpreted as a lodgement till left from the glacial tongue on the bottom of the overdeepened hollow. 3. materials and methods in order to perform pollen analysis, we collected 65 samples from the berceto core, in the interval between 4.30 and 30.00 m, and 70 samples from the lagdei core, in the interval between 2.50 and 8.50 m. peaty samples were prepared according to the techniques described by faegri & iversen and acetolysis (erdtman’s) procedures. sediment samples with prevailing inorganic content were treated according to standard laboratory protocols (zheng, 1986, modified): 10 grams of dried sediments, washing with hcl, soaking in hf, lüber tecnique, boiling in diluited 10% koh, followed by enrichment procedure, in particular gravitative separation using zncl2 (density 2,004 g/cm3) and sonication. during the first step of chemical treatment, a tablet containing a determined number of lycopodium spores was added to each sample in order to estimate the pollen concentration (stockmarr, 1971). an average of 400 pollen grains per sample were counted. the pollen flora is represented in analytical pollen diagrams (figs. 3-5). the pollen curves show the role and development of single taxa, both of the arboreal (ap) and herbaceous plants (nap). interpretation of the vegetational development is based on summary pollen diagrams, in which percentage curves either of selected pollen taxa (such as betula, picea, abies, fagus) or pollen groups are shown. specifically, these are: pinus-group: mainly pinus + other pioneering taxa, such as juniperus and hippophae; quercetum: mainly quercus, secondly corylus, ulmus, tilia, being acer, carpinus, ostrya and ilex sporadic; other ap: principally alnus, salix, cf. populus; artemisia-group: mainly artemisia + ephedra; other nap: in decreasing order of abundance, these are asteraceae, poaceae, caryophyllaceae, chenopodiaceae, cistaceae (helianthemum included), ranunculaceae (thalictrum included), brassicaceae, polygonaceae, fabaceae, plantaginaceae and other sporadic herbaceous taxa. hygro-hydrophytes are also included in this group, because their presence is persistently low and discontinuous. on the right side of the pollen diagrams, the ap concentration curve is represented. 4. results 4.1 berceto sequence pollen flora taxonomic details are shown in the analytical pollen percentage diagram (fig. 3). the ap are ever prevalent. in detail, in the middle-lower portion of the diagram pine (mainly pinus sylvestris-type and traces of p. mugo-type) clearly prevails accompanied by low values of picea, juniperus, hippophae, while broad-leaved trees (as quercus, betula, ulmus, tilia, carpinus, corylus, etc.) are sporadic. these last taxa with abies become significant only in the final spectra of the profile. the nap are represented continuously by ephedra (e. distachya-type and e. fragilis-type), artemisia and other asteraceae, chenopodiaceae, poaceae. open curves show ranunculaceae with thalictrum, brassicaceae, fabaceae, polygonaceae, plantaginaceae, rubiaceae, rosaceae, and traces of other nap, as dipsacaceae, ericaceae, gentianaceae, etc. the hygro-hydrophyta (cyperaceae, sparganiaceae, typhaceae, nymphaeaceae, myriophyllum) are very scarce. biostratigraphy the berceto summary pollen sequence (fig. 4) can be subdivided into three major segments. the basal segment is rather long, from 30.00 to 12.50 m depth, and characterized by a rather homogeneous pollen flora. specifically, pinus-group is dominant (percentages 80%-90% of the pollen sum) with relatively abundant picea, other ap occur sporadically, while the nap groups are largely subdued. further subdivisions of these segments in local pollen assemblage zones (paz) can be established based on the oscillations either of picea percentages or ap concentrations. indeed, paz ber-2, ber-4, ber-6 and ber-8 show relative high percentages of picea and appreciable ap concentrations (in excess of 5,000 grains/g); in contrast, paz ber-1, ber-3, ber5 and ber-7 are characterized by negligible values of picea and low ap concentrations (around 2,500 grains/g). the middle segment of the sequence, between 12.50 and 6.20 m depth, is characterized by two successive events of major increases in the nap complex, which simultaneously result in the two abrupt decreases in the pinus-group. new data from northern apennines ... 8 fi gu re 3 a na ly tic al p ol le n p er ce nt ag e d ia g ra m o f b er ce to . p er ce nt ag es r ef er to t he p ol le n su m (a p + n a p ). d ia g ra m m a p o ll in ic o a n a li ti c o d i b er ce to . le p er ce nt ua li si r ife ris co no a l co nt eg gi o to ta le d ei p ol lin i ( a p + n a p ). r. bertoldi et al. specifically, basal paz ber-9 is characterized by high percentages of the pinus-group (about 60% of the pollen sum), a decrease of the picea curve and very low ap concentrations (about 2,500 grains/g). the overlying paz ber-10 is characterized by a further decrease in the pinus-group, which falls at about 40% of the total pollen, a rise of herbs (especially artemisia) and the continuous presence of betula, which reaches 20% of the total sum in the uppermost pollen spectra. at first, the quercetum elements (essentially quercus and corylus grains) are scattered and dispersed. however, they increase and become continuous in the upper spectra of this pollen zone. picea shows a gradual decrease and abies is sporadic. ap concentrations are significant, since they vary from 7,500 to a maximum of 15,000 grains/g in the upper part of paz ber-10. the transition to the upper segment of the sequence, from 6.20 to 4.30 m of depth (paz ber-11), is marked by a sharp sedimentary gap, which results in a dramatic change in the overall vegetational state in respect to the lower paz ber-10. indeed, a cyclical turnover between abies and quercetum is observed, along with the decrease of other arboreal and nonarboreal taxa, apart from the other ap-group (alnus, salix, populus). ap concentrations raise up to the maximum value detected throughout the succession (about 190,000 grains/g). chronostratigraphy and vegetational-climatic features interpretation of the berceto succession can be attained by integrating floristic and biostratigraphic data with radiocarbon ages. globally, the berceto pollen sequence yielded an overall “modern” arboreal flora, which closely resembles the present-day woodlands of northern italy. therefore, it is strongly suggested, based on pollen evidence, that the berceto succession was laid during upper pleistocene and holocene times. the lower segment of the pollen diagram (fig. 4) shows four pollen zones paz ber-2, ber-4, ber-6 and ber-8 characterized by boreal-like pinus forests with picea alternating with four paz ber-1, ber-3, ber-5 and ber-7 characterized by steppe/forest-like of pinus. the radiocarbon ages from bulk sediment recovered at 22.50 and 11.65 meters depth (table 1) allow us to arrange chronologically the pollen zones sequence. the paz ber-1 and ber-2 are probably older than 30,000 year bp. the time interval between paz ber-3 and ber-8 corresponds very well to the last würmian pleniglacial (orombelli & ravazzi, 1996). the vegetation pattern suggests that in the mountain belt of northern apennines, drastic changes took place in the regional availability of effective moisture. specifically, the significant abundances of picea amidst the open pine woodlands is indicative of continental and moderately humid climates, which can be regarded as “interstadial” intervals. by contrast, the dominance of steppe/forest communities with pinus stands suggests harsher climatic conditions, thus fully consistent with “stadial” intervals. the middle segment of the succession encompasses the lateglacial, although documentation is interrupted abruptly by a sedimentary gap immediately above 11,150±70 14c yr bp, i.e. at 6.20 m depth. paz ber-9 represents a stadial interval, being characterized by the abrupt increase of herbs (nap) in an open woodland with pine. in contrast, the following paz ber-10 documents a more forested phase, evidenced by two distinct increases of the ap pollen concentration, with dominant pinus and, secondly, betula. the pollen features of ber-10 suggest that a transient reforestation event of the apennine slopes took place, principally in response to a significant increase in average temperatures. still, the overall sporadic occurrence of water-demanding trees suggests that effective moisture remained low, although in the uppermost spectra a slight increase in temperate elements is observed. in the uppermost segment of the sequence, i.e.: paz ber-11, abies and quercetum are dominant. this interval is in stark contrast with the previous ones, being characterized by vegetational features that are fully consistent with a postglacial phase. 4.2 lagdei site pollen flora the ap findings, as pinus, abies, quercus, tilia, ulmus, corylus, alnus + salix + populus, show widely variable curves. low and discontinuous values of juniperus, hippophae, picea, betula, acer, fraxinus, fagus, taxus (cf.) and other ap (traces of carpinus, ostrya, castanea, juglans, ilex, hedera ,viscum, cornus, etc) occur (fig. 5). the nap flora is qualitatively and quantitatively rich. the most important taxa are artemisia and other asteraceae and poaceae. chenopodiaceae, ranunculaceae with thalictrum, helianthemum, ericaceae, plantaginaceae, polygonaceae, caryophyllaceae, brassicaceae, umbelliferae, rosaceae show discontinuous curves. other nap, such as dipsacaceae, fabaceae, campanulaceae, rubiaceae show only sporadic values and the hygrohydrophyta (cyperaceae, sparganiaceae, typhaceae, hydrocharitaceae) are scarce. findings of ephedra were found only in the lower spectra. biostratigraphy and chronostratigraphy in the continuous and undisturbed lagdei-ii lacustrine succession, pollen data demonstrate that the interval between 2.40 and 8.30 m depth documents the lateglacial and the early postglacial. very good agreement exists 9 dating code sample conventional 14c age calibrated 14c age depth (m) (14c yr bp) (cal yr bp) beta 178882 6.20 11,50±70 13,390-13,240/13,240-12,900 beta 181866 11.65 14,80±50 17,705-17,00 beta 181867 22.50 19,620±290 -----------table 1 results of 14c datings from berceto core (beta analytic inc, miami, florida, u.s.a.) (from bertoldi et al. 2004). risultati delle datazioni radiocarbonio dei campioni di berceto (beta analytic inc, miami, florida, u.s.a.) (da bertoldi et al. 2004). new data from northern apennines ... 10 fi gu re 4 s um m ar y p ol le n p er ce nt ag e d ia gr am o f b er ce to w ith s el ec te d s in gl e ta xa (b et ul a, p ic ea , a b ie s) a nd p ol le n gr ou p in gs . t he p er ce nt ag es a re c al cu la te d w ith r es p ec t to t he t ot al p ol le n su m . o n th e le ft o f t he d ia gr am a re r ep re se nt ed t he s tr at ig ra p hi c co lu m n, t he r ad io ca rb on d at in gs a nd , o n th e ex tr em e rig ht , t he a p c on ce nt ra tio n cu rv e. il d ia gr am m a p ol lin ic o ria ss un tiv o d i b er ce to m os tr a si ng ol i t ax a se le zi on at i ( b et ul a, p ic ea , a b ie s) e r ag gr up p am en ti p ol lin ic i. le p er ce nt ua li so no c al co la te r is p et to a lla s om m a to ta le d ei p ol lin i. s ul la s in is tr a d el d ia gr am m a so no r ap p re se nt at e: la c ol on na s tr at ig ra fic a e le d at az io ni r ad io ca rb on io ; a ll’ es tr em ità d es tr a è rip or ta ta la c ur va d i c on ce nt ra zi on e a p . r. bertoldi et al. 11 fi gu re 5 a na ly tic al p ol le n p er ce nt ag e d ia gr am o f l ag d ei -i i. p er ce nt ag es r ef er t o th e p ol le n su m (a p + n a p ). d ia gr am m a p ol lin ic o an al iti co d i l ag d ei -i i. le p er ce nt ua li si r ife ris co no a l c on te gg io t ot al e d ei p ol lin i ( a p + n a p ). new data from northern apennines ... both in tempo and modes of the dynamics of the floristic taxa found in this sequence with respect to the previous one reported in bertoldi (1980). the criteria employed for subdividing the lagdei-ii pollen record (fig. 6) into 6 pollen assemblage zones, namely paz lgd-a to paz lgd-f, are the same as bertoldi (1980) here integrated with the ap concentration datum. as a result, it was at first demonstrated that the former subdivision proposed is in excellent correspondence with the zonation established in the lagdei-ii pollen record, where 4 age control points based on radiocarbon dating are also available (table 2). a major result is represented by the firm recognition of the lateglacial/ postglacial boundary, which occurs at 6.75 m depth in close correspondence to a manifest change both in vegetation and in sedimentation. age of the boundary is approximated by the radiocarbon age of 9,900±80 14c yr bp derived from a peaty sample at 6.50÷6.60 m depth. the transition to the postglacial is continuous and well documented by the stratigraphic sequence and pollen record, being correlative to the sharp transition from paz lgd-c to paz lgd-d. this is in agreement with the data derived from the core drilled in the centre of lagei hollow in 1980. besides this, the radiocarbon age 9,620±70 14c yr bp at 6.00÷6.10 m depth supports the attribution of the paz lgd-d to the basal holocene. the other radiocarbon datings (8,190±70 14c yr bp at 4.50÷4.60 m and 6,840±60 14c yr bp at 2.43÷2.53 m of depth) allow us to attribute the paz lgd-e and lgd-f to the early-middle holocene (table 2; fig. 6). paz lgd-a, lgd-b and lgd-c belong to the lateglacial. however, radiocarbon ages are not available in this segment and therefore, chronology of paz lgd-a, lgd-b and lgd-c is based on the occurrence of prominent vegetational features. paz lgd-a is consistent with the oldest dryas, being characterized by minimal ap concentrations (<1,000 grains/g) that document a steppe-like landscape with sparse pinus stands. paz lgd-b represents a closing pinus forest with scattered occurrences of other trees such as betula, picea, quercus, alnus and salix. the peculiar pollen assemblage and the increasing ap concentration (from 1,000 to 20,000 grains/g) are in full agreement with the well-known interstadials of the lateglacial. specifically, the two-folded distribution pattern of the ap concentration curve suggests that paz lgd-b encompasses the bölling alleröd interstadial complex. paz lgd-c is characterized by a culmination of the pinus-group curve, along with a decrease of herbs (especially the artemisia-group) and a sharp fall of the ap concentration. this interval is logically correlative to the younger dryas stadial oscillation. the beginning of the preboreal (i.e., the base of the holocene) is especially well documented. a last dramatic fall is observed of the pinus-group (base of paz lgd-d), which is gradually replaced by abies and temperate deciduous trees. from this point upwards, all herbaceous taxa are persistently subdued. 5. discussion 5.1 pleniglacial both vegetational data and radiocarbon ages indicate that the interval from ber-3 to ber-8 of the berceto pollen sequence (fig. 4) belongs to the last pleniglacial, which spans from ca. 30,000 to 15,000 yr bp, including the last glacial maximum (lgm) (see e.g. zagwijn & paepe, 1968; mangerud et al., 1974; woillard & mook, 1982; behre, 1989; allen et al., 1999; beaulieu de & reille, 1992; antonioli & vai [eds.], 2004; bini et al., 2004; orombelli et al., 2005). the chronostratigraphic interpretation of the berceto sequence is based on the oscillations of the picea percentage values. indeed, spruce survived during the pleniglacial in the northern apennines in relict area that represented its most southern refuges in europe (ravazzi, 2002). only during the lateglacial began a phase of contraction of the spruce range with its extinction at the beginning of the holocene, except two small areas where the spruce survived (chiarugi, 1936; bertoldi, 1980; ravazzi, 2002; ravazzi et al., 2006). as a consequence, moderate peaks of the percentage pollen curve of picea are climatically significant. the co-variance of the ap concentration curve confirms the significance of the picea culminations. specifically, paz ber-4, ber-6 and ber-8 document short-lived events of climatic amelioration (i.e., interstadials) that are older than 14,480±50 14c yr bp and thus are likely to develop during last pleniglacial times. based on these chronological ties, it is strongly suggested that paz ber-4, ber-6 and ber-8 correlate confidently with the well documented interstadials tursac, laugerie and lascaux that were first recognized and dated in pollen sequences from southern france by leroi-gourhan (1965, 1968, 1980) and confirmed afterwards by laville (1988) and weissmueller (1997). in the light of a long-distance correlation, the berceto pollen emergences are especially worthy of note and provide further evidence that latitudinal control on the vegetation in europe was especially strong during pleniglacial times. so far, indeed, documentation of tursac, laugerie and lascaux interstadials is virtually missing in central europe and north-eastern france (hammen van der et al., 1967; zagwijn & paepe, 1968; frenzel, 1968; woillard, 1978; behre, 1989) and largely 12 dating code sample conventional 14c age calibrated 14c age depth (m) (14c yr bp) (cal yr bp) roma-875 2,43-2.53 6,840±60 7,670-7,570 roma-876 4.50-4.60 8,190±70 9,250-8,990 roma-877 6.00-6.10 9,620±70 10,950-10,500 roma-878 6.50-6.60 9900±80 11,200-10,990 table 2 results 14c datings of lagdei-ii core (14c radiocarbon dating laboratory, dept. of earth sciences, university of rome, italy). risultati delle datazioni radiocarbonio dei campioni di lagdei-ii (radiocarbon dating laboratory, dipartimento di scienze della terra, università la sapienza-roma, italia). r. bertoldi et al. 13 fi gu re 6 s um m ar y p ol le n p er ce nt ag e d ia gr am o f la gd ei -i i w ith s el ec te d s in gl e ta xa (b et ul a, p ic ea , a b ie s, f ag us ) a nd p ol le n gr ou p in gs . th e p er ce nt ag es a re c al cu la te d w ith r es p ec t to t he to ta l p ol le n su m . o n th e le ft o f t he d ia gr am a re r ep re se nt ed t he s tr at ig ra p hi c co lu m n, t he r ad io ca rb on d at in gs a nd , o n th e ex tr em e rig ht , t he a p c on ce nt ra tio n cu rv e. il d ia gr am m a p ol lin ic o ria ss un tiv o d i l ag d ei -i i m os tr a si ng ol i t ax a se le zi on at i ( b et ul a, p ic ea , a b ie s, f ag us ) e ra gg ru p p am en ti p ol lin ic i. le p er ce nt ua li so no c al co la te r is p et to a lla s om m a to ta le d ei p ol lin i. s ul la s in is tr a d el d ia gr am m a so no r ap p re se nt at e: la c ol on na s tr at ig ra fic a e le d at az io ni r ad io ca rb on io ; a ll’ es tr em ità d es tr a è rip or ta ta la c ur va d i c on ce nt ra zi on e a p . new data from northern apennines ... incomplete in the eastern mediterranean region (wijmstra, 1969; bottema, 1979). in central-southern italy, where a fairly complete record of the last pleniglacial is provided by a number of pollen sequences (watts, 1985; follieri et al., 1988, 1989; lowe et al.,1996; allen et al., 1999) tursac, laugerie and lascaux events were not identified, although prominent peaks of ap curves at about 20,000 yr bp were recognized in several crater lakes in the lazio region (follieri et al., 1998; magri, 1999). furthermore, integrated analyses based on a wide range of climatic proxies (geomorphology, geochemistry, magnetic susceptibility, foraminifers) unravelled the occurrence of short-term events of climatic amelioration that are younger than 24,000 yr bp (antonioli & vai [eds.], 2004; carboni et al., 2005). however, in the sedimentary succession of the venice lagoon (northern italy: müllenders et al., 1996; serandrei et al., 2005) tursac and laugerie interstadials were recognized and age-calibrated at 22,270 and 19,060-19,260 yrs bp respectively; a detailed discussion from one of us is available in serandrei et al. (2005). interestingly, such interstadials were not detected by means of pollen analyses in the sedimentary cores recovered from the neighbouring po and veneto floodplains (amorosi et al., 1999, 2004; miola et al., 2003; bondesan et al., 2003). the lascaux interstadial, which is also correlative to the philippi interstadial (tenaghi philippon, greece: wijmstra, 1969), occurs between 17,800 and 16,500 yr bp (leroi-gourhan, 1965, 1968, 1980). this event was not documented in italian pollen records so far, although high-resolution studies have been performed on coeval sedimentary cores from the adriatic sea (zonneveld, 1996). indeed, the lascaux interstadial is not represented in the venice sedimentary succession because of a major stratigraphical gap that occurs in the upper part of the venice core (bortolami et al., 1977). in the lowermost part of the berceto core, a stadial (paz ber-1) and an interstadial (paz ber-2) have been recognized that are older than 29,620±290 14c yr bp. chronology of paz ber-2 is fully consistent with the arcy interstadial, which yielded an age of about 31,000 yr bp (leroi-gouhran, 1968). likely, this event corresponds to the onset of the denekamp interstadial, recognized in central and western europe (hammen van der et al., 1967; zagwijn & paepe, 1968; zagwijn, 1974; mangerud et al., 1974; woillard & mook, 1982; behre, 1989; beaulieu de et al., 1994). warming climatic oscillations referable to the same age but named differently were recognized, thanks to pollen data, both in crater lakes of central italy (follieri et al., 1998; magri, 1999) and in other european regions (gullentops, 1954; lumely de, 1965; wijmstra, 1969). in our opinion the paz ber-1 and ber-2 can be collocated at the end of the middle pleniglacial, as shown in table 3, where the likely correlation between the pollen zones of berceto and the central-southern european climatostratigraphy for the late upper pleistocene is shown. 5.2 lateglacial pollen data and radiocarbon age constraints recovered from the berceto and lagdei-ii records permit the reconstruction of the vegetation history in the mountain slopes of the northern apennines, both at low and high altitude, during the lateglacial period. specifically, the transition from paz ber-8 to paz ber-9 in the berceto sequence (fig. 4), characterized by the abrupt rise of nap and the concomitant decrease of the pinus-group, documents a peculiar vegetational pattern that is also observed at the pleniglacial/lateglacial boundary in southern europe. the pleniglacial/lateglacial boundary yielded an age of ca. 15,000-16,000 yr bp in many pollen sequences from central-western europe and from the adriatic region as well (hammen van der, 1957; zoller, 1960; hammen van der et al., 1967; behre, 1967; grüger, 1975; beaulieu de & reille, 1984a, 1984b; beaulieu de et al., 1985; reille & beaulieu de, 1988; beulieu de & reille, 1992; rossignol-strick et al., 1992; andrieu et al., 1993; beualieu de et al., 1994), in good agreement with the berceto record. indeed, the age datum of 14,480±50 14c yr bp observed at 11.65 m depth in the berceto core suggests that the base of paz ber-9 (at 12.57 m depth) is slightly older than 15,000 yr bp, thus possibly representing the pleniglacial/lateglacial boundary. this horizon was not identified in the lagdei-ii succession, where the boundary is likely to occur beneath the bottom of the recovered core. in the lagdei-ii pollen sequence (fig. 6), the lateglacial/postglacial boundary, as mentioned above, was pinned down at about 6.75 m depth (transition from paz lgd-c to paz lgd-d), in correspondence with the latest sharp decline of pinus, artemisia and other herbs, which occurs in concomitance with the immigration and the prominent increase of abies and warm-temperate trees. a radiocarbon dating performed at 6.50-6.60 m depth yielded an age of 9,900±80 14c yr bp, slightly younger than the age 10,300 yr bp conventionally established for the pleistocene/holocene boundary throughout europe, as testified by the abrupt change in different proxies (e.g. see in: zagwijn & paepe, 1968; zoller, 1960; mangerud, 1982; welten, 1982; burga, 1987; pons & reille, 1988; dansgaard et al., 1989; reille, 1993; beaulieu de et al., 1994; lang, 1994; bottema, 1995; lowe et al., 1996; friedrich et al., 1999). recently, the international commission on stratigraphy (gibbard, 2004) proposed to shift the boundary pleistocene/holocene at 10,000 yr 14c bp (11,550 ± 50 yr cal bp). with respect to the boundaries mentioned above, it is suggested that paz ber-9 and ber-10 of the berceto sequence, as well as the lower part of the lagdei-ii sequence (i.e., paz lgd-a, lgd-b and lgdc), represent the lateglacial. we attempted (table 4) a correlation between the pollen assemblage zones in the study sections and the chronozones as proposed and calibrated by mangerud et al. (1974). the ap concentration curve, which testifies the degree of arboreal coverage during the considered time interval, demonstrates that a significant correlation exists between major forestation events at berceto and lagdei. in particular, a steppe-woodland with pinus extended in the mountain slopes of the northern apennines during the oldest dryas. the observed lesser discrepancies in ap concentrations may still depend on the different altitudes of the studied sites. on the contrary, a sharp increasing trend of ap concentrations is documented in the upper lateglacial 14 r. bertoldi et al. chronozones, which are correlated to the böllingalleröd interstadial complex. in the berceto record, the percentages of the quercetum (essentially quercus and corylus), at the beginning overall sporadic, become continuous and important starting from the end of the alleröd interstadial. however, the stratigraphic record is interrupted abruptly at 11,150±70 14c yr bp, in relation to a major coring hiatus that hampered the preservation of the final lateglacial-early postglacial interval. on the other hand, the interval straddling the bölling-alleröd chronozones is continuous in the lagdei-ii succession, being characterized by the dominance of pinus with betula and the virtual dearth of temperate deciduous trees. paz lgd-c, similar indeed to paz lgd-b in terms of vegetation, corresponds to 15 table 3 local pollen assemblage zones, vegetational and climatic succession of the berceto core tentatively related to the main chronologic and climatostratigraphic units used in central-southern europe for the late upper pleistocene. tentativo di correlazione tra zone polliniche, successione vegetazionale e climatica di berceto con le unità cronologiche e climatostratigrafiche dell’europa centro-meridionale del tardo pleistocene superiore. new data from northern apennines ... the younger dryas as suggested both by the fall of the ap concentrations and radiocarbon datings. changes in ap concentrations and fluctuations of the ap/nap ratio in the study sections provide further information on the past altitude of both timberline and treeline during the latest pleistocene in the northern apennines. the beginning of mixed massive forestation after the lgm in the appennino parmense is apparently delayed with respect to other italian regions characterized by more favorable climates. indeed, the delayed northward diffusion of both abies and quercetum elements during postwürmian times was already documented in central and northern apennines (ferrarini, 1962). in central italy, the diffusion of temperate deciduous trees began after the lgm and came to a completion during lateglacial interstadials (follieri et al., 1988, 1989, 1998; magri, 1999; lowe et al., 1996; drescher-schneider et al., in press). in the insubrian lowland areas (northern italy), the same process begun during the alleröd interstadial and ended at the beginning of the holocene (zoller, 1960; beug, 1964; bertoldi, 1968; schneider, 1978, 1985; wick, 1996; gobet et al., 2000). pollen data from berceto and lagdei-ii document that the immigration of temperate deciduous trees in the northern apennines occurred at the end of alleröd interstadial at low altitudes (e.g. berceto, 820 m a.s.l.), whilst immigration and expansion of quercetum elements occurred at the beginning of the holocene at higher altitudes (e.g. lagdei, 1,254 m a.s.l.). chronological and vegetational constraints arising from this paper shed new light on both the tempo and fashion of forest development and dynamics in the northern apennine area during the lateglacial. in particular, our new data permit a reassessment of the pollen-based age model developed for the previous lagdei pollen record by bertoldi (1980). the latter interpretation was radically emended by lowe (1992) and lowe & 16 table 4 schema of the role of the principal arboreal and herbaceous taxa and correlation with the chronology for the lateglacial and early-middle holocene in the appennino parmense. schema del ruolo dei principali elementi arborei ed erbacei e loro correlazione nel quadro cronologico del tardoglaciale e dell’olocene inferiore e medio nell’appennino parmense. r. bertoldi et al. watson (1993) order to match the chronology of the prato spilla pollen record (cedra valley) (fig.1), where a mixed forest with abundance of abies and temperate deciduous trees was formerly present at the beginning of the lateglacial interstadials. the model of lowe (1992) and lowe & watson (1993) was challenging because of geobotanical evidence: actually, one had to infer that higher altitudes (that is, prato spilla at 1,350 m a.s.l.) were populated by forests rich in abies and temperate elements, while concomitantly, a pioneer arboreal vegetation almost exclusively, occasionally together with betula, was dominant at lower altitudes (i.e., lagdei, 1,254 m a.s.l. and berceto, 820 m a.s.l.). however, chronological ties presented in this paper provide evidence that the former model of the vegetational development for the lateglacial of bertoldi (1980) was overall correct. furthermore, the age model presented in this paper is supported by vegetation evidence in both berceto and lagdei, which are in good agreement with a number of pollen records either from central or northern italy, as mentioned above. 5.3 early holocene in the lagdei pollen record, paz d, e and f belong to the early-middle postglacial based on distinctive vegetational features. further detail is provided by radiocarbon age constraints, which suggest a correlation between this interval and the preboreal-early atlantic chronozones (table 4). vegetational development in the northern apennines during the holocene is well documented so far (chiarugi, 1936; ferrarini, 1962; braggio morucchio et al., 1978; bertoldi, 1980; bertoldi et al., 1986; gentile et al., 1988; cruise, 1990; lowe, 1992; lowe & watson, 1993; montanari et al., 1994; watson, 1996). in general, the early and middle holocene is dominated by mixed communities with abies and quercus, while during the middle-late holocene fagus is dominant. the immigration of fagus in the northern apennines postdates 6,800 yr bp (this paper), while its massive diffusion took place after 5,000 yr bp (lowe, 1992). as stated above, the base of paz ber-11 in the berceto record is marked by a major stratigraphic hiatus and the entire pollen zone is characterized by abundant abies and quercetum elements, while fagus is absent. this vegetational assemblage suggests that paz ber-11 belongs to the early holocene (table 4). 6. conclusions the studies performed on the lacustrine sediments of berceto and lagdei permitted us, as a whole, to obtain new data on the vegetational and climatic features that characterized the northern apennines starting before 30,000 yr b.p. the long time interval encompassed by the two sequences allowed the reconstruction of a succession of stadial/interstadial cycles that started in the latest middle pleniglacial, where a climatic cycle likely correlated to the arcy events was found. the onset of the last pleniglacial is older than of 29,620±290 yr bp and coincides with the beginning of paz ber-3, while its culmination is not settled in the pollen sequence. it is represented by alternanting stadial/interstadial events recorded in berceto core before 14,480±50 yr b.p. we stress that the events of climatic amelioration are tentatively correlated with the wellknown last pleniglacial interstadials: tursac, laugerie and lascaux. during which a boreal-like pinus forest with picea existed and climatic conditions characterized by a relative improvement of the temperature and, especially, by a slight increase in humidity occurred. the stadial phases were characterized by a steppe-woodland with pinus and moreover the pollen spectra testify cold continental climatic conditions, but not very dry. the pleniglacial/lateglacial boundary was recognized in a pollen succession and it is placed just before 14,480±50 yr b.p. the pollen results demonstrate that a steppeforest with pinus existed in the mountain region during the lowest lateglacial stadial (oldest dryas), while a boreal-like pinus forest with low values of picea and betula existed during the lateglacial interstadials at altitudes exceeding 800-900 m. a mixed pinus-betula woodland with broad-leaved trees, mostly quercus and corylus, occurred at lower altitudes only at the end of the alleröd interstadial, precisely at 11,150 ± 70 14c yr bp. the density of these woodlands is documented by significant variations of ap concentration values. from our pollen data the lateglacial/postglacial boundary, that occurred just before 9,900±80 yr b.p., is very prominent. indeed it records the definitive fall of the pioneer arboreal vegetation (pinus-group) and the diffusion and fast expansion of the abies and of the temperate deciduous trees. on the contrary the climatic cooling of the younger dryas has little evidence in the pollen spectra of the parma valley. indeed it is marked overall by the sharp fall of the ap concentration curve. this fact means that during this period an open woodland occurred in the higher mountain belt. this is in agreement with some findings in southern europe, where a diminution of the cooling effect during the younger dryas southwards across the continent was found (woillard & mook, 1982; watts, 1985; turner & hannon, 1988; rossignol strick et al., 1992) this palaeoenvironmental picture is in agreement with the geomorphological evidence in the northern apennines. this climatic event corresponds to the third glacial stage of federici & tellini (1983), during which glaciers were absent in parma valley or only small ones were confined in the cirques with an northern aspect. acknowledgements this work was supported by the local research fund fil 2006 (head: s. perego-università di. parma). the authors are grateful to the referees donatella magri and laura sadori (università la sapienza, rome) for the careful reading of the text, the useful suggestions and comments that helped to improve the manuscript. besides we are grateful to walter finsinger (university of utrecht) for the critical review of the manuscript. we are grateful to gilberto calderoni (radiocarbon dating laboratory of università la sapienza-rome) that performed the datings of lagdei core. 17new data from northern apennines ... references allen jrm., brandt u., brauer a., hubbertens hw., huntley b., keller j., kraml m., mackensen a., mingram j., negendank jfw., nowaczyk nr., oberhänsli h., watts wa., wulf s. & zolitschka b. (1999) rapid environmental changes in southern europe during the last glacial period. nature, 400, 740-743. amorosi a., colalongo m.l., fusco f., pasini g. & fiorini f. (1999) glacio-eustatic control of continental-shallow marine cyclicity from late quaternary deposits of the southeastern po plain, northern italy. quaternary research , 52, 1-13. amorosi a.., colalongo ml., fiorini f., fusco f., pasini g., vaiani s.c. & sarti g. (2004) palaeogeographic and palaeoclimatic evolution of the po plain from 150-ky core records. global and planetary change, 40, 55-78. andrieu v., eicher u. & reille m. (1993) le fin du dernier pléniglaciare dans les pyrénées (france): donée polliniques, isotopiques et radiométriques,c.r. académie des sciences, paris, t.316 (s.ii), 245-250. antonioli f. & vai g.b. (eds.) (2004) litho-palaeoenvironmental maps of italy during the last two climatic extremes. explanatory notes. 32nd international geological congress, florence, italy, pp. 80. beaulieu de j.l. & jorda m. (1977) tardiglaciaire et postglaciaire des alpes de haute provence. bulletin association française pour etude du quaternairy 3, 3-15. beaulieu de j.l. & reille m. (1984a) a long upper pleistocene pollen record from les echets, near lyon, france. boreas, 13, 111-132. beaulieu de j.l. & reille m. (1984b) the pollen sequence of les echets (france): a new element for the chronology of the upper pleistocene. géographie physique et quaternaire, 38, 3-9. beaulieu de j.l., pons a. & reille m. (1985) recherches pollenanalytiques sur l’histoire tardiglaciaire et holocene de la vegetation des monts d’aubrac (massif central, france) . review palaeobotany & palynology, 44, 37-80. beaulieu de j.l. & reille m. (1992) the last climatic cycle at la grande pile (vosges, france). a new pollen profile. quaternary science reviews, 11, 431-438. beaulieu de j.l., andrieu j.j., lowe j.j., ponel p. & reille m. (1994) the weichselian lateglacial in southwestern europe (iberian peninsula, pyrenees, massif central, northern apennines). journal of quaternary science, 9, 101-108. behre k.e. (1967) the late glacial and early postglacial history of vegetation and climate in nothwestern germany. review palaeobotany & palynology, 4, 149-161. behre k.e. (1989) biostratigraphy of the last glacial period in europe. quaternary science reviews, 8, 25-44. bertoldi r. (1968) ricerche pollinologiche sullo sviluppo della vegetazione tardiglaciale e postglaciale nella regione del lago di garda. studi trentini scienze naturali, 45, 87-162. bertoldi r. (1980) le vicende vegetazionali e climatiche nella sequenza paleobotanica würmina e post-würmiana di lagdei (appennino settentrionale). acta naturalia, ateneo parmense, 18, 147175. bertoldi r., timossi a.m., borghi m.l. & magri d. (1986) studio di una piccola torbiera montana dell’appennino emiliano attraverso i microfossili vegetali. l’italia forestale e montana, 41(4), 216230. bertoldi r., chelli a., roma r., tellini c. & vescovi p. (2004) first remarks on the late pleistocene lacustrine deposit in the berceto area (northern apennines, italy). il quaternario, italian journal quaternary sciences, 17, 133-143. beug h.j. (1964) untersuchungen zur spätund postglazialen vegetationsgeschichte im gardaseegebiet unter besonderer berücksichtigung der mediterranen arten. flora, 154, 401-444. bini a., borsato a., carraro f., carton a., corbari d., cucato m., monetato g. & pellegrini g.b. (2004) definizione di alcuni termini in uso nella cartografia dei depositi quaternari continentali in ambito alpino. il quaternario, italian journal quaternary sciences, 17, 75-82. bondesan a., meneghel m., miola a.& valentini g. (2003) paleoenvironmental reconstruction from lgm to historical time in the lower coastal plain of the piave river. preliminary pollen analysis on a 20 m core of lagoon and fluvial sediments. i l quaternario, italian journal quaternary sciences, 16(1bis), 183-192. bortolami g.c., fontes j.c., markgraf v. & saliere j.f. (1977) land, sea and climate in the northern adriatic region during late pleistocene and holocene. paleogeograpyhy paleoclimatology paleoecology, 21, 139-156. bottema s. (1979) pollen analytical investigations in thessali (grece). palaeohistoria, 21, 19-40. bottema s. (1995) the younger dryas in the eastern mediterranean. quaternary science review, 14, 883-892. braggio morucchio g., guido m.a. & montanari c. (1978) studio palinologico e della vegetazione della torbiera del lajone presso piampaludo (gruppo m. beigua, appenino ligure occid.). archivio botanico.biogeografico italiano, 54, 115136. burga c.a. 1987 gletscher und vegetationsgeschichte der südrätischen alpen seit der späteiszeit. birkhäuser verlag, basel., 161 pp. carboni m.g., bergamin l., di bella l., landini b., mandra l. & vesica l. (2005) late quaternary paleoclimatic and paleoenvironmental changes in the tyrrenian sea. quaternary science reviews, 24, 2069-2082. chiarugi a. (1936) ricerche sulla vegetazione della etruria marittima. nuovo giornale botanico italiano, 43, 1-61. cruise g.m. (1990) holocene peat initiation in the ligurian apennines, northern italy. review palaeobotany & palynology, 63, 173-182. dansgaard w., white j.w.c. & johnsen s.j. (1989) the abrupt termination of the younger dryas climate event. nature, 339, 532-534. drescher-schneider r., de beaulieu j.l., magny m., 18 r. bertoldi et al. walter-simonnet a.v., bossuet g., millet l., brugiapaglia e. & drescher a. – vegetation history, climate and human impact over tha last 15,000 years at lago dell’accesa (tuscany, central italy). vegetation history and archaeobotany, (in press). federici p.r. (1977) tracce di glacialismo pre-wurmiano nell'appennino parmense. rivista geografica italiana, 84, 205-216. federici p.r. & tellini c. (1983) la geomorfologia dell’alta val parma (appennino settentrionale). rivista geografica italiana, 90(3/4), 393-428. ferrarini e. (1962) analisi polliniche di depositi lacustri dell’appennino lunigianese con osservazione sulla vegetazione attuale. accademia italiana scienze forestali, 11, 61-95. follieri m., magri d. & sadori l. (1988) 250.000 year pollen record from valle di castiglione (roma). pollen et spores, 30, 329-356. follieri m., magri d. & sadori l. (1989) pollen stratigraphical synthesis from valle di castiglione (roma). quaternary international, 3/4, 81-84. follieri m., giardini m., magri d. & sadori l. (1998) palynostratigraphy of the last glacial period in the volcanic region of central italy. quaternary international, 47/48, 3-20. frenzel b. (1968) grundzüge der pleistozänen vegetationsgeschichte nord-eurasien. franz steiner verlag gmbh, erdwiss. forsch. 1, wiesbaden, 326 pp. friedrich m., kromer b., spurk m., hofmann j. & kaiser k.f. (1999) palaeo-environment and radiocarbon calibration as derived from late glacial/ early holocene tree-ring chronologies. quaternary international, 61, 27-39. gentile s., guido m.a., montanari c., paola g., braggio morucchio g. & petrillo m. (1988) ricerche geobotaniche e saggi di cartografia della vegetazione del piccolo bacino di lago riane (appennino emiliano). braun blanquetia, 2, 77-104. gibbard p. (2004) – quaternary …now you seeit, now you don’t!. quaternary perspectives, 14(2), 89-91. gobet e., tinner w., hubschimd p., jansen i., wehrli m., ammann b. & wick l. (2000) – influence of human impact and bedrock differences on the vegetational history of the insubrian southern alps. vegetation history and archaeobotany, 9(3), 175187. grüger e. (1975) pollenanalyse spätpleistozäner und holozäner sedimente aus der adria. geologische jahrbuch, 29, 3-32. gullentops f. (1954) contribution à la chronologie du pléistocène et des formes du relief en belgique. institut géologique universitaire, louvain, xviii, 123-252. hammen van der t. (1957) the stratigraphy of the lateglacial. geologie en mijnbouw, 19, 250-254. hammen van der t., maarleveld g.c., vogel j.c. & zagwijn w.h. (1967) stratigraphy, climatic succession and radiocarbon dating of the last glacial in the netherlands. geologie en mijnbouw, 46, 79-95. laville h. (1988) recent developments on the chronostratigraphy of the paleolithic in the périgord. in: dibble h.l & montet-white a.(eds.): upper pleistocene prehistory of western eurasia. university monograph, 54, 147-160. lang g. (1994) quartäre vegetationsgeschichte europas. fischer verlag, jena, 462 pp. leroi-gourhan a. (1965) chronologie des grottes d’arcy-sur-cure. gallia-préhistoire, 7, 1-64. leroi-gourhan a. (1968) dénominations des oscillations wurmiennes. bulletin de l’association française pour l’etude du quaternaire, 4, 281-287. leroi-gourhan a. (1980) interstades wurmiens: laugerie et lascaux. bulletin de l’association française pour l’etude du quaternaire, 3, 95-100. losacco u. (1949) la glaciazione quaternaria dell'appennino settentrionale. rivista geografica italiana, 56, 1142. lowe jj. (1992) lateglacial and early holocene lake sediments from the northern apennines, italy – pollen stratigraphy and radiocarbon dating. boreas, 21,193-208. lowe jj. & watson c. (1993) lateglacial and early holocene pollen stratigraphy of the northern apennines, italy. quaternary science reviews, 12, 727-738. lowe jj., accorsi ca., bandini mazzanti m., bishop a., van der kaars s., forlani l., mercuri am., rivalenti c., torri p. & watson c. (1996) pollen stratigraphy of sediment sequences from lakes albano and nemi (near rome) and from the central adriatic, spanning the interval from oxygen isotope stage 2 to the present day. memorie istituto italiano idrobiologia, 55, 71-98. lumely de h. (1965) evolution des climats quaternaires d’après le remplissage des grottes de provence et du languedoc méditerranéen . bulletin de l’association française pour l’etude du quaternaire, 2, 165-170. magri d. (1999) late quaternary vegetation history at lagaccione near lago di bolsena . review paleobotany & palynology, 106, 171-208. mangerud j., anderson st., berglund be. & donner j. (1974) quaternary stratigraphy of norden, a proposal for terminology and classification. boreas, 3, 109-128. mangerud j. (1982) the chronostratigraphic subdivision of the holocene in norden; a review. striae, 16, 65-70. miola a., albanese d., valentini g. & corani l. (2003) pollen data for a biostratigraphy of lgm in the venetian po plain. il quaternario, italian journal quaternary sciences, 16, 21-25. montanari c., guido ma., boccaccia a. & rametta m. (1994) paleoecologia olocenica del monte gottero (parma) nel quadro della storia del popolamento vegetale dell’appennino ligure. i l quaternario, italian journal quaternary sciences, 7 (1), 373-380. müllenders w., favero v., coremans m. & dirickx m. (1996) analyses polliniques des sondages à venise (ve1, ve1bis, ve2 ) . aardkundige mededelingen, 7, 87 – 117. orombelli g. & ravazzi c. (1996) – the late glacial and early holocene: chronology and paleoclimate. il quaternario, italian journal quaternary science, 9(2),439 –444. orombelli g., ravazzi c. & cita m.b. (2005) osservazioni sul significato dei termini lgm 19new data from northern apennines ... (umg), tardoglaciale e postglaciale in ambito globale, italiano ed alpino. il quaternario, italian journal quaternary science, 18(2), 147-155. pons a. & reille m. (1988) the holocene and upper pleistocene pollen record from padul (granada, spain). a new study . palaeogeography palaeoclimatology palaeoecology, 66, 243-263. ravazzi c. (2002) – late quaternary history of spruce in southern europe . review palaeobotany & palynology, 120, 131-177. ravazzi c., donegana m., vescovi e., arpenti e., caccianiga m., kaltenrieder p., londeix l., marabini s., mariani s., pini r., vai g.b. & wick l. (2006) – a new late-glacial site with picea abies in the northern apennine foothills: an exception to the model of glacial rifugia of trees. vegetation history and archaeobotany, 15(4), 357-371. reille m. (1993) l’interface tardiglaciaire-holoène dans un site du littoral atlantique sud-europèen : le moura (pyrénées atlantiques, france). c.r. académie des sciences, paris, 316, 463-468. reille m. & beaulieu de j.l. (1988) history of the würm and holocene vegetation in western velay (massif central, france): a comparison of pollen analysis from three corings at lac du bouchet. review paleobotany & palynology, 54, 233-248. rossignol-strick m., planchais n., paterne m. & duzer d. (1992) vegetation dynamics and climate during the deglaciation in the south adriatic basin from a marine records. quaternary science reviews, 11, 415-423. schneider r. (1978) pollenanalytische untersuchungen zur kenntnis der spätund postglazialen vegetationsgeschichte am südrand der alpen zwischen turin und varese (italien). botanische jahrbücher, systematik, 100, 26-109. schneider r. (1985) palynologic research in the southern and southeastern alps between torino and trieste – a review of investigations concerning the last 15000 years. dissertationes botanicae, 87, 83-106. sercelj a. (1966) pollenanalytische untersuchungen der pleistozänen und holozänen ablagerungen von ljubljansko barje. razprave, 9, 1-44. serandrei barbero r., bertoldi r., canali g., donnici s. & lezziero a. (2005) paleoclimatic record of the past 22,000 years in venice (northern italy): biostratigraphic evidences and chronology. quaternary international, 140-141, 37-52. servizio geologico d'italia, (2002) carta geologica d'italia alla scala 1:50.000 f. 216 borgo val di taro" e note illustrative del foglio (aa.vv). servizio geologico sismologico e dei suoli, regione emilia-romagna, s.el.ca, firenze. stockmarr j. (1971) tablets with spores used in absolute pollen analysis. pollen et spores, 13, 615621. turner c. &, hannon g.e. (1988) vegetational evidence for late quaternary climatic changes in southwest europe in relation to the influence of the northern atlantic ocean. philosophical transactions of the royal society of london, 318, 451-485. watson cs. (1996) the vegetational history of the northern apennines, italy: information from three new sequences and review of regional vegetational change. journal of biogeography, 23, 805841. watts wa. (1985) a long pollen record from laghi di monticchio, southern italy: a preliminary account. journal. geological society, london, 14, 491-499. weissmüller w. (1997) eine korrelation der delta 18 oereignisse des grönlandischen festlandeises mit den interstadialen des atlantischen und des kontinentalen europas in zeitraum von 45 bis 18 ka. quartär, 47/48, 51-111. welten m. (1982) vegetationsgeschichtl iche untersuchungen in den westlichen schweizer alpen: bern-wallis. denkschriften schweizerischen naturforschenden gesellschaft, 95, 1104. wick l. (1996) – late-glacial and early-holocene palaeoenvironments in brianza, n italy . i l quaternario-ital ian journal of quaternary sciences, 9(2), 653-660. wijmstra t.a. (1969) palynology of the first 30 metres of a 120 m deep section in northern greece. acta botanica neederlandica, 18, 511-27. woillard m.g. (1978) grande pile peat bog: a continuous pollen record for the last 140.000 years. quaternary research, 9, 1-21. woillard mg. & mook w. (1982) carbon-14 dates at grande pile: correlation of land and sea chronologies. science, 215, 159-161. zagwijn wh. (1974) vegetation, climate and radiocarbon datings in the late pleistocene of the netherlands. part i i : middle weichselian . mededelingen rijks geologische dienst, n.s., 25, 101-111. zagwijn wh. &, paepe r. (1968) die stratigraphie der weichselzeitlichen ablagerungen der niederland und belgiens. eiszeitalter und gegenwart, 19, 129-146. zheng z. (1986) contribution palynologique a la connaissance du neogene du s-e francais et ligurie. phd thesis, université sciences et techniques du languedoc, montpellier, france. zoller h. (1960) pollenanalytische untersuchungen zur vegetationsgeschichte der insubrischen schweiz . denkschriften schweizerischen naturforschenden gesellschaft, 83(2), 45-156. zonneveld k.a. (1996) palaeoclimatic reconstruction of the last deglaciation (18-8 ka b.p.) in the adriatic sea region; a land-sea correlation based on palynological evidence. palaeogeography palaeoclimatology palaeooecology, 122, 89-106. 20 ms. ricevuto il 12 dicembre 2006 testo definitivo ricevuto il 14 marzo 2007 ms. received: december 12, 2006 final text received: march 14, 2007 r. bertoldi et al. imp.forno&lucchesi la successione fluviale terrazzata pleistocenica dei versanti occidentale e nordoccidentale della collina di torino maria gabriella forno1 & stefania lucchesi2 1dipartimento di scienze della terra, università di torino 2c.n.r. istituto di geoscienze e georisorse, sezione di torino riassunto: forno m. g. & lucchesi s., la successione fluviale terrazzata pleistocenica dei versanti occidentale e nordoccidentale della collina di torino. (it issn 0394-3356, 2005). gli studi precedenti riguardanti l’evoluzione geologica quaternaria della collina di torino hanno consentito di evidenziare in modo preliminare le tracce di un reticolato idrografico pleistocenico, sensibilmente sospeso e con andamento molto differente rispetto ai corsi d’acqua sviluppati attualmente nel rilievo collinare. il rilevamento geologico dei versanti occidentale e nordoccidentale effettuato in occasione del presente studio, i cui risultati sono riassunti nella carta geologica alla scala 1:20.000 allegata, permette di ricostruire con maggiore dettaglio la distribuzione della successione fluviale conservata sulle sommità delle dorsali spartiacque. il riconoscimento dei diversi termini di questa successione, distribuiti in corrispondenza a differenti fasce altimetriche, è facilitato dalla loro espressione morfologica: corrispondono a lembi di superfici terrazzate con estensione compresa tra alcune migliaia e alcune decine di migliaia di m2, spesso evidenziati dalla presenza di antichi edifici residenziali, e localmente a più estesi relitti di meandri incastrati. l’estrema antropizzazione dell’area e la diffusa copertura eolica e colluviale rappresentano invece un ostacolo all’analisi sul terreno. malgrado le difficoltà incontrate, l’estremo dettaglio con cui è stato effettuato il rilevamento geologico ha consentito di riconoscere corpi sedimentari di origine fluviale, con spessore metrico, in corrispondenza alla maggior parte dei lembi descritti; localmente tali forme sono risultate invece modellate direttamente sui termini marini terziari. i numerosi lembi sono stati distinti tra loro e correlati in base al differente sviluppo altimetrico e alla diversa alterazione dei sedimenti, che hanno consentito il riferimento cronologico dell’intera successione all’intervallo di tempo corrispondente al pleistocene medio e superiore. l’attuale assetto altimetrico delle forme relitte, variamente sospeso rispetto alla pianura con un dislivello compreso tra 20 e 400 m, la loro distribuzione complessiva, in corrispondenza alle attuali dorsali secondo fasce allungate parallelamente allo spartiacque collinare, e l’allungamento prevalente dei singoli lembi, svincolato dall’andamento dei corsi d’acqua attuali, suggeriscono il legame con una situazione morfologica e geologica del rilievo collinare notevolmente diversa dall’attuale. e’ possibile in particolare ipotizzare lo sviluppo di corsi d’acqua con andamento circa parallelo allo spartiacque principale: l’impostazione estremamente recente dell’attuale f. po al margine nordoccidentale del rilievo collinare, già documentata in letteratura, indica che le tracce prese in esame sono invece da collegare a precedenti andamenti del reticolato affluente; lo studio mineralogico dei sedimenti, oggetto di un lavoro specifico tuttora in corso, consente di ipotizzare una alimentazione essenzialmente dai bacini dei fiumi dora riparia e stura di lanzo. lo sviluppo altimetrico anomalo dei lembi fluviali relitti e la presenza di scarpate con altezza di alcune decine di metri tra i diversi ordini suggeriscono una successione di episodi di approfondimento erosionale del reticolato idrografico, connessa con il sollevamento recente dell’edificio collinare. la successione terrazzata esaminata rappresenta quindi il risultato della progressiva deformazione del settore distale dei conoidi alpini, coinvolti nel sollevamento della collina di torino e nella migrazione verso nw del suo margine esterno, che hanno portato al loro inglobamento nell’area collinare. si può stimare che tale deformazione, tutt’ora in atto, abbia avuto, nell’intervallo compreso tra il pleistocene medio e l’olocene, una componente verticale con velocità media di sollevamento relativo di circa 1 mm/anno abstract: forno m. g. & lucchesi s., the fluvial pleistocenic terraced succession of w and nw slopes of the collina di torino. (it issn 0394-3356, 2005). previous studies about the quaternary evolution of the collina di torino put in evidence in a preliminary way traces of a pleistocenic hydrographic net, suspended and with a different pattern from the watercourses now developed in the relief. the geological survey of the western and northwestern slopes carried out during the present study, synthesized in the attached geological map at 1:20.000 scale, allows a more detailed reconstruction of the distribution of the fluvial terraced succession preserved on the secondary watersheds. the identification of the various relics of the succession, distributed with different elevations, is suggested by its morphology: they correspond to terraced surfaces with an extension between some thousands and some tens of thousands of m2, often underlined by ancient buildings, and locally to wider remains of embedded meander. the local manmade modifications of the area and the loess and colluvial covers are instead obstacles for the field work. despite these difficulties the extreme detail used for the geological survey allows the recognition of fluvial sedimentary bodies, some meters thick, associated with the main described shapes: locally the terraced surfaces appear modelled directly on the tertiary marine sediments. the different shapes are identified and correlated by the elevation and the alteration degree of the sediments, suggesting the chronological reference to the middle and upper pleistocene. the present elevation of the remains, suspended from 20 to 400 m on the plain, their distribution in the present ridges along strips parallel to the main watershed and their elongation, different from the present watercourses, suggest a link with a very different morphological and geological situation of the relief. in particular it can be supposed the trend of watercourses parallel to the main watershed: the extremely recent setting of the present river po along the northern boundary of the relief, already known by literature, shows that the examined remains are instead connected to a previous trend of the hydrographic net; mineralogical analysis, still in progress, suggest an alimentation particularly from the stura di lanzo and dora riparia basins. the anomalous elevation of the fluvial succession and the presence of scarps some tens of meters high between the different orders of terraces suggest a succession of erosional deepening episodes of the hydrographic net, connected to the uplifting of the collina di torino. the examined terraced succession represents the result of the deformation of the distal sector of the alpine fluvial aprons, involved in the uplift of the turin hill and in the northwestern migration of its external margin, and their embedding in the hilly area. it can be supposed that this deformation, still in action, had a rate of uplift of the order of 1mm/yr from the middle pleistocene to the holocene. parole chiave: collina di torino, depositi fluviali, deformazione, pleistocene. keywords: collina di torino, fluvial sediments, deformation, pleistocene. il quaternario italian journal of quaternary sciences 18(2), 2005, 123-134 124 g. forno & s. lucchesi 1. introduzione la presenza di lembi di superfici pianeggianti sul versante occidentale della collina di torino era già stata osservata localmente in occasione di precedenti indagini geologiche (boano & forno, 1997; forno et al., 2002); studi successivi, riguardanti anche il versante nordoccidentale, avevano consentito di valutare in modo preliminare la diffusione di queste forme e di ricostruire la loro distribuzione secondo determinate fasce altimetriche: l’insieme degli elementi raccolti aveva permesso di interpretarli come i relitti di più estese superfici pianeggianti costituenti una successione fluviale terrazzata riferibile al pleistocene medio e superiore, indicativa di una sensibile deformazione recente dell’area collinare (boano et al., 2002; boano et al., 2004). il presente lavoro sintetizza i risultati ottenuti dallo studio sistematico di questa successione, effettuato attraverso un rilevamento geologico di dettaglio alla scala 1:10.000 dei versanti occidentale e nordoccidentale della collina di torino. in particolare si è realizzata una carta geologica (tav. 1) in cui sono rappresentate le singole forme di modellamento fluviale, erosionali e deposizionali, che hanno consentito di effettuare una ricostruzione complessiva della successione terrazzata. il lavoro effettuato è risultato difficoltoso per la ridotta estensione dei lembi, per la generalizzata scarsità di affioramenti e per la presenza di una diffusa copertura di loess eolico e di prodotti colluviali. e’ stato inoltre condizionato dall’intensa antropizzazione dell’area, iniziata già nel 1700, che determina condizioni particolari per quanto riguarda l’acquisizione dei dati geologici: da un lato i frequenti scavi per la realizzazione di edifici offrono l’occasione di osservare periodicamente i sedimenti e di integrare le indagini sul terreno con le prove geotecniche o le perizie geologiche esistenti; da un altro lato, essendo l’area in esame adibita in larga misura ad uso residenziale, la raccolta dei dati è notevolmente ostacolata dalle difficoltà di accesso alle proprietà (fig. 1). l’acquisizione dei dati è inoltre talvolta impedita da interventi antropici di diversa entità, che determinano una modesta densità di affioramento e creano alcune difficoltà nel ricostruire la morfologia originaria dei lembi di superfici terrazzate: spesso i sedimenti appaiono mascherati da muri e pavimentazioni; talvolta si hanno modifiche morfologiche, quali ad esempio l’ampliamento degli originari settori pianeggianti tramite riporti sorretti da muri e interventi di spianamento, o avviene la dissezione delle originarie forme terrazzate per la realizzazione di nuovi accessi alle proprietà. solo molto localmente gli interventi determinano invece la creazione di settori pianeggianti totalmente artificiali che, ad un’analisi più dettagliata, appaiono chiaramente non correlabili ai lembi naturali sia per una anomala distribuzione plano-altimetrica sia per le dimensioni, generalmente più ridotte. 2. lavori precedenti la successione di sedimenti marini terrigeni costituenti il rilievo collinare, di età compresa tra l’eocene e il pliocene, è stata oggetto di numerosi lavori a carattere generale tra cui ricordiamo la seconda edizione del foglio geologico “torino” alla scala 1:100.000 (bortolami et al., 1969), le relative note illustrative (bonsignore et al., 1969) e alcuni approfondimenti successivi (sturani, 1975). le ricerche svolte negli ultimi anni hanno riguardato essenzialmente la ricostruzione degli eventi deformativi che interessano la successione marina: la struttura collinare è stata interpretata come una antiforme separata dall’antistante pianura padana tramite un insieme di importanti elementi tettonici sepolti, indicati complessivamente come "thrust padano" (consiglio nazionale delle ricerche, 1990; piana & polino, 1994) (cfr. inserto 1 di tav. 1). per quanto riguarda i sedimenti quaternari dell’area collinare nella cartografia ufficiale (bortolami et al., 1969) sono stati indicati esclusivamente i principali fig. 1 in corrispondenza a numerosi lembi di superfici terrazzate sono stati costruiti antichi edifici residenziali: nell’immagine è osservabile il lembo di villa prever (attuale villa abeg) (q. 292) riferibile all’unità di monte dei cappuccini (2 in tav. 1). some ancient villas have been built in various terraced surfaces: in the picture it can be seen the surface of villa prever (present villa abeg) at 292 m, related to the monte dei cappuccini unit (2 in tav. 1). fig. 2 il profilo geologico in corrispondenza al lembo di villa gualino (unità 4 in tav. 1) evidenzia un corpo sedimentario fluviale sviluppato in discordanza al di sopra del substrato marino e coperto dal loess eolico. 1) substrato marino; 2) depositi fluviali; 3) depositi colluviali; 4) loess eolico; 5) terreno di riporto (modificato da boano et al., 2004). the geological section of the villa gualino terraced surface (unit 4 in tav. 1) shows a fluvial sedimentary body in unconformity on the marine bedrock and covered by the aeolian loess. 1) marine bedrock; 2) fluvial sediments; 3) colluvial sediments; 4) aeolian loess; 5) dum (modified from boano et al., 2004). 5 4 3 2 1 lembi della copertura di loess e non compariva invece la successione fluviale oggetto del presente studio; i sedimenti eolici dell’area collinare, riferibili al pleistocene superiore, sono stati in seguito oggetto di indagini specifiche, che hanno consentito di differenziarli dagli altri termini e di precisarne la distribuzione e lo spessore (forno, 1979; 1990). il primo elemento significativo per la ricostruzione dell’evoluzione quaternaria dell’area in esame è stata l’ipotesi di carraro (1976) secondo la quale il settore di pianura sviluppato immediatamente a nw della collina di torino sarebbe stato modellato dagli attuali affluenti del f. po e non dal corso d’acqua principale, impostato in questo settore in epoca estremamente recente: la conferma di questa ipotesi è avvenuta negli anni successivi attraverso il riconoscimento della presenza, in corrispondenza al versante meridionale della collina di torino e all’adiacente altopiano di poirino, di sedimenti fluviali associati a relitti di meandri incastrati riferibili al pleistocene medio e superiore, indicativi del deflusso del precedente collettore principale a sud della collina di torino (forno, 1980; forno, 1982; carraro et al., 1982). in seguito gli studi riguardanti l’evoluzione pliopleistocenica dell’area piemontese hanno evidenziato come la collina di torino e l’area di pianura sviluppata immediatamente a nw del rilievo siano stati e siano tuttora interessati da un comportamento geodinamico differente, corrispondente rispettivamente ad un sensibile sollevamento e ad una relativa stabilità (carraro et al., 1987): le stesse ricerche hanno considerato questa evoluzione differenziale la principale responsabile delle profonde modificazioni nell’assetto del reticolato idrografico dell’area piemontese durante il pleistocene. studi specifici sulla composizione dei clasti costituenti i depositi fluviali connessi con il collettore sviluppato sul versante meridionale della collina di torino suggeriscono l’alimentazione da parte del settore alpino occidentale, compreso tra la val sangone e le valli di lanzo (compagnoni & forno, 1992) (cfr. inserto 2 di tav. 1). solo recentemente è stata effettuata una cartografia preliminare della successione di forme fluviali terrazzate pleistoceniche conservate sul versante occidentale del rilievo collinare: tali indagini hanno consentito una prima ricostruzione, essenzialmente su base morfologica, dell’antico reticolato idrografico e un riferimento, su base pedostratigrafica, al pleistocene medio e superiore (boano & forno, 1997). in corrispondenza ad una di queste forme, e in particolare al lembo di villa gualino, caratterizzato da notevole estensione, lo studio di un insieme di sondaggi a carotaggio continuo ha consentito di individuare la presenza nell’immediato sottosuolo di un corpo lenticolare di depositi fluviali 125la successione fluviale pleistocenica ... sabbioso-siltosi, con spessore di circa 5 metri, che poggia in discordanza sui termini marini ed è coperto dal loess eolico (forno et al., 2002) (fig. 2). un quadro più completo dell’evoluzione del reticolato idrografico pleistocenico del piemonte centrale è contenuto in carraro et al . (1994): successivi approfondimenti riguardanti la collina di torino ne hanno precisato l’intensa evoluzione tettonica recente (boano et al., 2000; boano et al., 2002; boano et al., 2004). 3. assetto morfologico la collina di torino costituisce un rilievo che supera i 700 m di quota e si eleva di circa 500 rispetto fig. 3 modello digitale del terreno del piemonte centrale: la collina di torino, incisa al margine settentrionale dall’attuale f. po, forma un rilievo che si innalza di circa 500 m sulla pianura, costituita dagli estesi conoidi dei corsi d’acqua alpini (modificato da arpa piemonte, sigeoonline, 2004). terrestrial digital model of the central piedmont: the collina di torino develops a relief that is cut at the northern margin by the river po and that rises from the plain formed by the wide alpine fluvial aprons of about 500 metres (modified from arpa piemonte, sigeoonline, 2004). fig. 4 vista da nw degli estesi lembi di superfici terrazzate del versante nordoccidentale della collina di torino, sospesi di alcune centinaia di metri rispetto al tratto di pianura padana su cui sorge la città di torino. nw sight of the wide terraced surfaces of the northwestern slope of the collina di torino. they are suspended some hundreds of metres respect to the sector of po plain where the town of torino is built. 126 alla contigua pianura padana occidentale, dalla quale è separato tramite l’incisione del f. po (fig. 3). l’area in esame corrisponde, in particolare, ai versanti occidentale e nordoccidentale del rilievo collinare delimitati, rispetto al versante meridionale, dallo spartiacque principale con direzione circa sw-ne. entrambi i versanti presentano un insieme di ampie dorsali allungate, caratterizzate da andamento rispettivamente e-w e senw, separate tra loro da incisioni relativamente strette modellate dall’attuale reticolato idrografico affluente del f. po, con profondità compresa tra alcune decine e il centinaio di metri: a partire da sw si sviluppano in particolare le dorsali di moncalieri, boccia d’oro, ronchi, cavoretto, tetti rovei, san vito, santa margherita, villa rey, reaglie, mongreno, superga e costa parigi (tav. 1). la caratteristica morfologica più evidente delle dorsali collinari è rappresentata dal loro profilo longitudinale articolato: la regolarità nell’inclinazione delle dorsali è interrotta da numerosi lembi di superfici pianeggianti o debolmente inclinate (fig. 4) e, localmente, da ampie depressioni allungate, in contropendenza. i lembi pianeggianti hanno estensione relativamente ridotta, compresa tra 5.000 e 25.000 m2, e allungamento per lo più indipendente dall’andamento dell’attuale reticolato idrografico collinare. in generale presentano una modesta inclinazione, in media del 3% verso w o nw, secondo l’allungamento delle dorsali: nel dettaglio i lembi sviluppati a quote maggiori mostrano complessivamente inclinazioni più sensibili e ondulazioni più marcate (cfr. inserto 6 in tav. 1); i lembi a quote inferiori appaiono invece meno inclinati e sono caratterizzati da un andamento relativamente pianeggiante (fig. 1). le depressioni allungate, caratterizzate da un settore centrale depresso di qualche metro rispetto alle aree laterali, hanno distribuzione planimetrica localizzata nella fascia altimetrica superiore del versante occidentale: mostrano un evidente andamento arcuato in pianta e ampiezza relativamente estesa, fino a diverse migliaia di m2 (cfr. inserto 4 in tav. 1). l’insieme dei dati in seguito esposti consente di interpretare questi elementi morfologici come i relitti di antiche forme fluviali costituenti una successione terrazzata (fig. 4): in particolare i lembi pianeggianti rappresentano settori conservati, marginali, di precedenti pianure alluvionali e le depressioni in contropendenza corrispondono a relitti di antichi meandri incastrati. dal punto di vista altimetrico la successione terrazzata è distribuita in corrispondenza a gran parte dello sviluppo delle dorsali, tra 630 e 240 m di quota (tav. 1). i singoli lembi mostrano una distribuzione altimetrica concentrata in determinate fasce altimetriche: possono essere raggruppati in undici ordini di forme terrazzate conservati per il versante occidentale e quattordici per quello nordoccidentale; nel dettaglio le singole dorsali non mostrano in genere testimonianza dell’intera successione, ma preservano un numero minore di ordini (cfr. inserto 7 in tav. 1). in generale si osserva che le forme fluviali a quote superiori sono conservate in modo discontinuo e appaiono più profondamente rimodellate e dissecate; i relitti a quote inferiori mostrano invece una distribuzione relativamente continua e appaiono generalmente più estesi e meglio conservati. le diverse forme terrazzate sono separate tra loro da scarpate con acclività compresa tra il 10 e 12 % e altezza di alcune decine di metri, relativamente costante per ogni singolo ordine. per quanto riguarda, invece, i caratteri planimetrici si osserva che le diverse forme sviluppate a quote confrontabili mostrano una distribuzione complessiva secondo fasce allungate in direzione s-n, sul versante occidentale, e sw-ne, su quello nordoccidentale (cfr. inserto 3 in tav. 1): è da sottolineare che questo andamento, circa parallelo allo spartiacque principale, è invece trasversale a quello degli attuali corsi d’acqua collinari. come precisato più avanti l’ampia distribuzione altimetrica complessiva della successione, generalizzata a gran parte del rilievo collinare, suggerisce che i fenomeni di modellamento fluviale siano avvenuti a spese di un rilievo interessato da una sensibile deformazione recente (boano et al., 2004). le ondulazioni e le ridotte dimensioni delle forme conservate sono invece indicative del rimodellamento da parte del ruscellamento diffuso e della dissezione da parte del reticolato idrografico attuale, caratterizzato da notevoli gradienti e impostato in sedimenti facilmente erodibili. come descritto dettagliatamente in seguito, l’allungamento complessivo s-n e sw-ne di queste forme suggerisce il legame delle originarie forme fluviali con un precedente reticolato idrografico, circa parallelo allo spartiacque principale (cfr. inserto 3 in tav. 1), progressivamente coinvolto nella deformazione dell’edificio collinare e dissecato dagli attuali corsi d’acqua. la presenza di questa successione favorisce la spiccata vocazione residenziale dell’area in esame, compresa in gran parte nel comune di torino: in particolare sui lembi terrazzati sono costruite le antiche ville che caratterizzano l’area collinare (fig. 1); le incisioni fluviali, corrispondenti ai tratti più ripidi dei versanti caratterizzati da diffusi fenomeni di dissesto, sono invece per lo più incolti e presentano una fitta vegetazione arbustiva. 4. la successione fluviale terrazzata la successione fluviale terrazzata conservata sui versanti occidentale e nordoccidentale della collina di torino è costituita da numerose forme relitte distribuite in modo piuttosto uniforme e secondo fasce allungate parallelamente all’attuale spartiacque collinare. solo in corrispondenza al settore di valsalice, compreso tra le dorsali di san vito a sw e di santa margherita a ne, non sono conservate forme di modellamento fluviale riconducibili a quelle presenti nel resto del rilievo (tav. 1). in generale si è osservato che le forme sviluppate a quote inferiori preservano in modo relativamente continuo gli originari sedimenti fluviali: questi sono interessati da suoli meno evoluti, con indice di colore compreso tra 7.5 yr e 10 yr (munsell soil color charts). i lembi a quota superiore conservano invece solo in modo sporadico gli originari depositi fluviali: su questi depositi, o direttamente sui termini marini, si sviluppano suoli profondamente evoluti, con indice di colore compreso tra 2.5 yr e 5 yr (munsell soil color charts). in corrispondenza alla maggior parte dei lembi g. forno & s. lucchesi 127 pianeggianti terrazzati sono conservati depositi prevalentemente fini (fig 5): le analisi granulometriche effettuate indicano che i diversi campioni (curve a, b, c, d, e, f, j in fig. 6) corrispondono a sabbie-limose debolmente argillose e mostrano una composizione tessiturale tra loro piuttosto simile; in particolare si osserva una prevalenza dei granuli con dimensioni comprese tra 1 e 0.01 mm: tale composizione tessiturale, indicativa di una scarsa selezione dei depositi e caratterizzata dalla presenza di “code” sia ghiaiose sia argillose, è in accordo con l’origine fluviale dei sedimenti in esame (rizzetto et al., 1998); è inoltre evidente la loro differenziazione rispetto al loess eolico presente localmente al di sopra dei sedimenti fluviali (fig. 6), con il quale macroscopicamente possono essere confusi, contraddistinto invece da una maggiore selezione tessiturale (forno, 1979). in corrispondenza ai relitti di meandri incastrati sono invece conservati sedimenti con tessitura ghiaioso-sabbiosa più eterogenea (curva i in fig. 6). la successione fluviale terrazzata è stata differenziata utilizzando il criterio allostratigrafico, attraverso il riconoscimento delle discontinuità erosionali che definiscono la base e il tetto delle singole unità: le superfici sommitali delle unità sono direttamente rilevabili sul terreno; le loro superfici di appoggio basale, invece, sono osservabili solo localmente e talvolta identificabili tramite dati di sottosuolo. in generale le diverse unità sono state definite sulla base di un insieme di caratteri: 1) distribuzione altimetrica delle forme terrazzate che, anche se conservate in tutto lo sviluppo dei versanti, mostrano una distribuzione preferenziale secondo determinate fasce altimetriche; 2 continuità laterale delle forme terrazzate, che risultano dissecate dalle attuali incisioni; 3) analoga entità del rimodellamento e della dissezione che interessano le forme terrazzate; 4) estensione confrontabile delle forme terrazzate; 5) analoga morfologia delle forme, corrispondenti a superfici pianeggianti o a relitti di meandri incastrati; 6) analoghi facies e grado di conservazione dei depositi fluviali; 7) grado di evoluzione dei suoli confrontabile. complessivamente la successione terrazzata mostra un assetto altimetrico connesso con la deformazione recente (boano et al., 2004): i diversi lembi in origine erano distribuiti a quota sensibilmente inferiore, corrispondente allo sviluppo altimetrico della originaria pianura. l’insieme dei dati raccolti suggerisce però che tale deformazione sia confrontabile per i diversi lembi appartenenti ad una determinata fascia altimetrica e non alteri i rapporti tra le diverse fasce, che risultano separate tra loro da scarpate con altezza di alcune decine di metri (cfr. inserto 7 in tav. 1). si osserva inoltre come, anche nel dettaglio, lo sviluppo altimetrico dei singoli lembi terrazzati possa variamente discostarsi da quello originario, corrispondendo a forme relativamente antiche interessate da un più o meno intenso rimodellamento ad opera del ruscellamento diffuso e/o dal seppellimento da parte di una copertura eolica o colluviale: a seconda dei casi, si prospettano diverse relazioni tra la configurazione attuale e quella originaria. in particolare, valutando caso per caso la natura (1a, 1b, 1c, 1d, 2a, 2b, 2c, 2d in fig. 7) dei lembi attualmente conservati (t) è possibile ricondurli a due differenti tipologie originarie corrispondenti rispettivamente a lembi modellati nel substrato marino, già inizialmente privi di depositi fluviali (1), e a lembi caratterizzati dall’originaria presenza di sedimenti fluviali (2). nel primo caso, ossia a partire da un’originaria superficie di erosione impostata nel substrato (e), si possono formare lembi (t) con una quota leggermente inferiore (1a), a seguito del rimodellamento da parte del ruscellamento diffuso, lembi con uno sviluppo altimetrico confrontabile (1b e 1c), se interessati dallo stesso rimodellamento e da un successivo seppellimento ad opera di una copertura eolica e/o colluviale con spessore modesto, o infine lembi a quota leggermente più elevata (1d), a seguito unicamente del seppellimento ad opera della stessa copertura. nel secondo caso, ossia a partire da un’originaria superficie di accumulo dei sedimenti fluviali (a), si possono formare lembi (t) con uno sviluppo altimetrico leggermente inferiore impostati negli stessi sedimenti fluviali (2a), a seguito di un modesto rimodellamento da parte del ruscellamento diffuso, lembi con uno sviluppo altimetrico confrontabile se interessati dallo stesso rimodellamento e da un successivo seppellimento ad opera di una copertura eolica e/o colluviale di modesto spessore (2b e 2c), o infine lembi a quota leggermente più elevata, a seguito unicamente del seppellimento ad opera della stessa copertura (2d). infine, anche a partire da un’originaria configurazione di accumulo, si può verificare lo sviluppo di una superficie di erosione modellata a quota inferiore nel substrato marino (1a), a seguito della completa asportazione dei sedimenti fluviali. a commento della ricostruzione sopraesposta occorre precisare come non risulti sempre facile ricostruire l’evoluzione di un lembo terrazzato conservato nell’area collinare e definire quale fosse la situazione originaria. in generale si può affermare che, maggiore è il grado di rimodellamento e di dissezione delle forme, maggiore è la variazione rispetto alla configurazione originaria. nel dettaglio la presenza di prodotti colluviali a spese di depositi fluviali pedogenizzati, a valle di un determinato lembo terrazzato, indica l’esistenza di un’originaria copertura fluviale; al contrario lo sviluppo di suoli sul substrato marino suggerisce l’assenza, già in origine, dei depositi fluviali o il loro spessore estremamente ridotto. le configurazioni attuali più semplici da interpretare corrispondono ai lembi in cui è conservata l’originaria copertura fluviale, riconducibile alla situazione iniziale di accumulo (a). più difficili da valutare sono invece i lembi attualmente modellati nel substrato marino (1a), per i quali risulta spesso impossibile ricondurli ad un’originaria superficie di erosione (e) o ad una superficie di accumulo (a): in questi casi il riconoscimento della configurazione originaria può essere talvolta facilitato da altre evidenze. secondo il criterio allostratigrafico, l’elemento da utilizzare per correlare tra loro i diversi corpi sedimentari corrisponde alla superficie di erosione che ne segna la base: nel caso della successione terrazzata della collina di torino, considerando le limitazioni sopra la successione fluviale pleistocenica ... 128 accennate tra cui soprattutto la scarsità di affioramenti e le loro modeste dimensioni, che non consentono nella maggior parte dei casi di osservare la superficie basale dei depositi fluviali, si è dovuto ricorrere a considerare la quota della superficie attualmente visibile. quest’ultima, come sopra illustrato, può corrispondere sia ad una superficie di erosione modellata nel substrato marino (e) sia ad una superficie di accumulo dei depositi fluviali (a). in ogni caso la differenza di quota fra le due configurazioni è poco significativa in quanto sia lo spessore dei sedimenti fluviali sia l’entità del rimodellamento o dell’eventuale seppellimento, ad opera di sedimenti eolici o colluviali, comportano variazioni di alcuni metri e sono pertanto trascurabili se confrontati con le differenze altimetriche tra le diverse unità, corrispondenti alle scarpate che le separano, con altezza invece di alcune decine di metri (cfr. inserto 7 in tav. 1). nell’ambito di una stessa fascia altimetrica si determinano spesso condizioni di conservazione analoghe e quindi, a parità di quota, si confrontano di fatto elementi con lo stesso significato geologico. va inoltre precisato come, nei casi in cui uno stesso lembo risulti sviluppato a quota diversa da monte verso valle o in senso trasversale, viene sempre considerata, come riferimento, la quota più elevata in quanto rappresenta presumibilmente la situazione più conservativa (fig. 7). i dati raccolti a seguito del rilevamento geologico alla scala 1:10.000 sono sintetizzati nella carta geologica allegata (tav. 1): tenendo presente le possibili modificazioni antropiche precedentemente descritte, si è cercato di realizzare una cartografia dei soli lembi almeno in parte naturali, tralasciando ovviamente i lembi creati artificialmente. in particolare sono rappresentati tutti gli elementi morfologici e i depositi conservati sulle dorsali, facenti parte della successione fluviale terrazzata originaria: non sono invece cartografati gli elementi morfologici e i depositi conservati entro le incisioni fluviali attuali, connessi con il successivo modellamento da parte del reticolato affluente. i lembi che conservano i sedimenti fluviali sono rappresentati in modo differente da quelli privi di depositi: considerando la ridotta estensione dei lembi terrazzati, che rende la successione preservata di difficile lettura, si è anche effettuata una rappresentazione schematica della probabile distribuzione complessiva delle diverse unità costituenti la successione fluviale terrazzata, prima della dissezione da parte del reticolato idrografico affluente. tale rappresentazione è stata realizzata sulla base della distribuzione plano-altimetrica degli elementi conservati, integrata con quella dei prodotti colluviali che rielaborano gli originari sedimenti fluviali: comprende un insieme di “fasce” allungate parallelamente all’attuale spartiacque, indicate in colore più tenue rispetto alle relative aree di conservazione degli elementi morfologici e dei sedimenti. sono stati infine rappresentati i depositi fluviali conservati in pianura, che costituiscono il riferimento altimetrico della distribuzione originaria delle unità più recenti. le unità individuate sono state indicate con una numerazione progressiva, a partire da quelle conservate nelle fasce altimetriche inferiori: per quelle a quota più elevata, a causa della mancanza di correlabilità tra gli elementi dei due versanti, è stato necessario effettuare un’ulteriore differenziazione delle unità, introducendo il riferimento “w” per il versante occidentale e “n” per quello nordoccidentale (cfr. inserti 5 e 7 in tav. 1). i principali caratteri relativi ad ogni singola unità vengono di seguito brevemente descritti a partire da quelle a quota inferiore. 1 l’unità di madonna del pilone comprende cinque lembi terrazzati sviluppati ad una quota compresa tra 258 e 240 m, con distribuzione estremamente discontinua in entrambi i versanti, e una sella in contropendenza immediatamente a e del monte dei cappuccini (fig. 10). i lembi, che conservano una superficie subpianeggiante prossima a quella originaria, mostrano estensione generalmente ridotta di poche centinaia di m2: l’unico lembo di dimensioni rilevanti, con estensione di circa 4.000 m2, è quello più settentrionale (v. savio) sede dell’istituto piante da legno “ipla” (stop 2.11 in carraro et al, 2005). in corrispondenza ai diversi lembi sono stati osservati sedimenti fluviali sabbioso-siltosi scarsamente addensati, con spessore variabile tra 3 e 4 m, molto debolmente alterati e g. forno & s. lucchesi fig. 5 aspetto dei depositi fluviali siltoso-sabbiosi affioranti in corrispondenza al lembo di superficie terrazzata di villa prever (attuale v. abeg, q. 292, unità 2). aspect of the silt-sandy fluvial deposits outcropping in the terraced surface of villa prever (292 m, unit 2). fig. 6 curve granulometriche cumulative dei sedimenti presi in esame, confrontate con la curva del loess eolico affiorante a villa gualino: (a) scuola di s. margherita; (b) ne di tetti rovei; (c) cavoretto; (d) il bellardo; (e) villa s. croce; (f) villa sambuelli; (g) villa rey; (h) e di residenza superga ; (i) torre; (j) boccia d’oro. granulometric cumulative curves of the examined sediments, compared with the curve of the aeolian loess outcropping at villa gualino: (a) scuola of s. margherita; (b) ne of tetti rovei; (c) cavoretto; (d) il bellardo; (e) villa s. croce; (f) villa sambuelli; (g) villa rey; (h) e of residenza superga ; (i) torre; (j) boccia d’oro. caratterizzati da suoli bruno-giallastri con indice di colore 10 yr 4/4÷5/3 (munsell soil color charts): solo in corrispondenza al lembo su cui è costruito parte del centro storico di moncalieri, sulla dorsale omonima, non si sono potute effettuare osservazioni sulla costituzione dei sedimenti. nel lembo di v. savio, al di sotto dei sedimenti siltosi, sono stati rinvenuti in affioramento e individuati nei sondaggi, per uno spessore di alcuni metri, sedimenti fluviali ghiaiosi, caratterizzati da ciottoli prevalentemente allungati con dimensioni comprese tra alcuni cm e alcuni dm, costituiti da serpentiniti, prasiniti, quarziti e gneiss; nel lembo della chiesa di sassi, al di sotto dei sedimenti siltosi, sono stati rinvenuti sedimenti fluviali sabbiosi, con spessore visibile di circa 2 m. 2 l’unità del monte dei cappuccini è rappresentata da diciannove lembi terrazzati sviluppati tra 300 e 280 m, conservati con notevole continuità laterale su entrambi i versanti. i lembi, anch’essi caratterizzati da una superficie subpianeggiante prossima a quella originaria, hanno estensione media di alcune centinaia di m2 (fig. 1) e allungamento preferenziale in direzione s-n nel versante occidentale e circa sw-ne in quello nordoccidentale: nella quasi totalità dei casi conservano depositi fluviali sabbioso-siltosi scarsamente addensati, con spessore medio di circa 2 m, molto debolmente alterati e caratterizzati da suoli bruno-giallastri con indice di colore compreso tra 10 yr 4/4 e 10 yr 5/4 (fig. 5); localmente i sedimenti presentano pseudogley di colore grigio 2,5 y 5/4. particolarmente significativi risultano i lembi del monte dei cappuccini (fig. 8) e del convitto principessa felicita di savoia, in corrispondenza ai quali è osservabile uno spessore di circa 2 m di depositi fluviali sabbiosi con colore bruno-giallastro 10 yr 4/4. 3 l’unità di villa rey comprende nove lembi terrazzati conservati tra 320 e 310 m, aventi dimensioni piuttosto ridotte, forma irregolare e superficie debolmente ondulata; la distribuzione areale dei lembi è disomogenea in quanto appaiono in gran parte concentrati sul versante nordoccidentale. nella quasi totalità dei casi conservano depositi fluviali siltoso-sabbiosi, con spessore visibile compreso tra 2 e 3 m, debolmente alterati e caratterizzati da suoli con indice di colore variabile tra bruno-giallastro 10 yr 4/3 e bruno 7.5 yr 4/6 e da una modesta cementazione carbonatica. in alcuni affioramenti, in particolare presso villa rey sulla dorsale omonima, al di sopra dei sedimenti fluviali è osservabile una copertura con spessore variabile tra 2 e 4 m di loess eolico, caratterizzato da una note129 fig. 7 diverse configurazioni (t) degli attuali lembi di superfici terrazzate (1a, 1b, 1c, 1d, 2a, 2b, 2c, 2d) a partire dalle due possibili tipologie iniziali (1 e 2), a seguito di fenomeni di rimodellamento e/o seppellimento. different configuration (t) of the present terraced surfaces (1a, 1b, 1c, 1d, 2a, 2b, 2c, 2d) from two possible initial conditions (1 and 2) as a consequence of remodelling and/or burial phenomena. la successione fluviale pleistocenica ... vole coesione e da una evidente fessurazione prismatica (forno, 1979; 1990); la lisciviazione di questi depositi è responsabile della locale cementazione dei depositi fluviali e della formazione di un livello di caliche, con spessore di alcuni centimetri, a sottolineare il limite tra i due sedimenti. 4 l’unità di villa gualino comprende sedici lembi terrazzati conservati tra 345 e 320 m, con notevole continuità laterale: i lembi mostrano estensione media di alcune centinaia di m2 e allungamento variabile; presentano una superficie ondulata, indicativa di un sensibile rimodellamento. nella quasi totalità dei casi conservano gli originari depositi fluviali siltososabbiosi, con spessore conservato compreso tra 2 e 5 metri, mediamente alterati e caratterizzati da suoli con indice di colore bruno 7.5 yr 4/4; su alcuni lembi, al di sopra dei sedimenti fluviali, si sviluppa una copertura di loess eolico con spessore metrico. particolarmente esteso risulta il lembo di villa gualino sulla dorsale di s. vito, compreso in questa unità e già oggetto di uno studio specifico (forno et al., 2002) (fig. 2): la realizzazione di numerosi sondaggi ha consentito di precisare la geometria lenticolare dei sedimenti fluviali in cui è modellato, con spessore di circa 5 m, costituiti da un termine inferiore sabbioso e da un termine superiore essenzialmente siltoso; al di sopra dei sedimenti fluviali si sviluppa il loess eolico, carbonatico, con spessore metrico. particolarmente significativo è anche il lembo sviluppato a sw dell’abitato di cavoretto, sulla dorsale omonima: conserva diffusamente depositi fluviali siltosi, osservabili per uno spessore di circa 3 m e coperti dal loess eolico, con spessore di circa 2.5 m; i depositi fluviali sono caratterizzati nella parte inferiore da concentrazioni di noduli di mn con diametro millimetrico. 5 l’unità di cavoretto è rappresentata anch’essa da sedici lembi terrazzati conservati su entrambi i versanti tra 370 e 340 m e caratterizzati da una superficie ondulata, indicativa di un sensibile rimodellamento. nel versante occidentale i lembi mostrano una buona continuità laterale, dimensioni compresa tra 50 e 300 m2 e allungamento prevalente s-n; nel versante nordoccidentale i lembi risultano invece sensibilmente dissecati, mostrano dimensioni molto più ridotte e allungamento variabile. la continuità laterale di questa unità sembra essere interrotta nel settore di valsalice, compreso tra le dorsali di san vito e santa margherita, al raccordo tra i due versanti. nella maggior parte dei casi, soprattutto sul versante occidentale, conservano gli originari depositi fluviali siltososabbiosi, con spessore conservato fino a 3 m e appaiono mediamente alterati, con indice di colore bruno 7.5 yr 4/4. particolarmente significativo è il lembo di tetti rovei, sulla dorsale omonima, caratterizzato da un corpo fluviale lenticolare con spessore di circa 2,5 m: la superficie di appoggio dei sedimenti fluviali, con andamento concavo, appare sottolineata da un orizzonte carbonatico di spessore centimetrico. 6n l’unità del bellardo è rappresentata da sette lembi terrazzati conservati esclusivamente nel versante nordoccidentale, tra 380 e 370 m, e caratterizzati da una superficie ondulata, indicativa di un sensibile rimodellamento. i lembi mostrano estensione generalmente ridotta di poche decine di m, e allungamento prevalentemente in direzione se-nw. solo alcuni lembi conservano gli originari depositi fluviali, generalmente siltoso-sabbiosi o siltoso-argillosi, con indice di colore 7.5 yr 4/6: particolarmente significativo è il lembo del bellardo sulla dorsale di realie, allungato in direzione n-s; in corrispondenza a questo lembo si osservano sedimenti fluviali siltososabbiosi con spessore visibile di circa 2 m. 7n l’unità del fortino è rappresentata da otto lembi terrazzati, ondulati nel dettaglio, conservati esclusivamente in corrispondenza al versante nordoccidentale tra 390 e 385 m. i singoli lembi hanno estensione generalmente inferiore a 100 m2, allungamento variabile da e-w a se-nw e conservano solo localmente gli originari depositi fluviali, caratterizzati da tessitura siltoso-sabbiosa o siltoso-argillosa e indice di colore medio 5 yr 4/6. la maggior parte dei lembi risultano invece modellati direttamente sul substrato terziario, interessato da un suolo con grado di evoluzione confrontabile a quello dei sedimenti fluviali localmente preservati, come ad esempio in corrispondenza al lembo di villa corra. particolarmente significativi sono i lembi del fortino, sulla dorsale di santa margherita, e di villa maggia, sulla dorsale di reaglie; in entrambi i casi i lembi non risultano compresi nella fascia di interpolazione dell’unità 7n ma sono inglobati in quelli della successiva unità 6n, rispetto alla quale appaiono sospesi; in corrispondenza a entrambi si osservano localmente sedimenti fluviali siltoso-sabbiosi, costituenti corpi lenticolari con spessore rispettivamente di circa 2,5 e 5 m, separati dal substrato sottostante da superfici di erosione con andamento concavo. 8w e 8n le unità di san vito e di villa sambuelli comprendono rispettivamente nove e dodici lembi conservati sui versanti occidentale, tra 415 e 410 m, e nordoccidentale, tra 420 e 400 m. le due unità mostrano caratteri morfologici e sedimentologici confrontabili: sono state tuttavia tra loro differenziate, in quanto non vi è continuità laterale tra i lembi sviluppati nei due versanti; i lembi del versante occidentale si raccordano con i relitti di meandri incastrati conservati nel versante meridionale a quota leggermente inferiore. i lembi di entrambi i versanti hanno superficie debolmente ondulata e risultano piuttosto articolati in pianta; hanno estensione di alcune centinaia di m2, mediamente superiore rispetto alle altre unità, e allungamento variabile. generalmente conservano, in particolare per l’unità di san vito, gli originari depositi fluviali siltosi, con spessore visibile di 2-3 m e indice di colore medio 5 yr 5/6; negli altri casi risultano invece modellati direttamente sul substrato terziario, su cui si sviluppa un suolo con grado di evoluzione confrontabile a quello dei sedimenti fluviali localmente preservati. particolarmente significativi sono i lembi di villa racca, sulla dorsale di boccia d’oro, e di villa maria, sulla dorsale di villa rey, entrambi allungati in direzione e-w; in corrispondenza a questi lembi, al di sotto di una copertura di loess ricco di gasteropodi continentali, con spessore di circa 3 m, si osservano per uno spessore di 2 m sedimenti fluviali siltoso-argillosi, caratterizzati da una colorazione bruno-rossastra 5 yr 4/4, dalla presenza di patine di argilla e da una notevole cementazione da parte degli ossidi di fe, indicative di una sensibile alterazione pedogenetica. in corrispondenza al lembo di v. cavoretto, sulla dorsale di boccia d’oro, sono invece osservabili sedimenti fluviali ghiaiosi con spessore visibile di circa 2 m: i ciottoli, con diametro variabile tra alcuni centimetri e circa 10 cm, sono costituiti prevalentemente da serpentiniti e anfiboliti con subordinati prasiniti, gabbri e micascisti; al di sopra di questi depositi si sviluppa una copertura di loess con spessore di circa 4 m, ricco di concrezioni carbonatiche allungate verticalmente. anche in corrispondenza al lembo di villa sambuelli, sulla dorsale di regalie, si osservano sedimenti fluviali sabbiosoghiaiosi, con spessore di alcuni metri: i ciottoli, con diametro da centimetrico a decimetrico, sono costituiti da serpentiniti, gabbri, peridotiti, prasiniti, gneiss e calcari. localmente al margine dei lembi sono presenti prodotti colluviali, legati alla rielaborazione degli originari sedimenti fluviali da parte del ruscellamento diffuso, come ad esempio nei lembi di villa paradiso, villa maria, villa sambuelli, la fagianella, villa ada e villa lena. 9w e 9n – le unità dei ronchi e di villa tabasso comprendono rispettivamente cinque e dieci lembi conservati sui versanti occidentale, tra 445 e 430 m, e nordoccidentale, tra 445 e 425 m (cfr. inserto 6 in tav. 1). anche in questo caso le due unità, pur mostrando caratteri morfologici e sedimentologici confrontabili, sono state tra loro differenziate in quanto non vi è continuità laterale tra i lembi sviluppati nei due versanti; i lembi del versante occidentale si raccordano con i relitti di meandri incastrati conservati nel versante meridionale a quota leggermente inferiore. i lembi di entrambi i versanti sono caratterizzati da forma allungata, in direzione compresa tra e-w e se-nw, e da una superficie ondulata indicativa di un sensibile rimodellamento; risultano piuttosto articolati in pianta e hanno estensione di alcune centinaia di m2. solo i lembi sviluppati nel versante occidentale e il lembo di villa tabasso, nel versante nordoccidentale, conservano i depositi fluviali, con spessore visibile compreso tra 2 e 4 m e colore bruno-rossastro variabile tra 5 yr 4/2÷5/3. particolarmente significativi sono i lembi di villa bobella, nella dorsale di boccia d’oro , e di villa tabasso, nella dorsale di reaglie: al di sopra del substrato marino si sviluppano depositi fluviali siltoso-argillosi relativamente omogenei con uno spessore di circa 4 m, caratterizzati da una colorazione bruno-rossastra 5 yr 5/4. 10w l’unità di c. feno comprende tre lembi molto allungati e con larghezza ridotta sviluppati sul versante occidentale tra 490 e 485 m: sono caratterizzati da allungamento prevalente e-w e andamento ondulato, indicativo di un sensi130 g. forno & s. lucchesi bile rimodellamento. queste forme si raccordano con relitti di meandri osservabili nel versante meridionale, a quota leggermente inferiore. conservano gli originari depositi fluviali siltoso-argillosi caratterizzati da un colore bruno-giallastro 5 yr 4/6; solo in corrispondenza al lembo di c. feno, sulla dorsale di cavoretto, si osservano ridotti affioramenti di sedimenti ghiaiosi. 11w l’unità di torre comprende due relitti di meandri incastrati sviluppati esclusivamente sul versante occidentale tra 510 e 495 m, con forma irregolare in pianta ed estensione di alcune migliaia di m2: queste forme si raccordano con analoghi relitti conservati nel versante meridionale a quota leggermente inferiore. tali relitti si differenziano sensibilmente dai lembi pianeggianti delle altre unità, oltre che per le maggiori dimensioni, per il profilo trasversale concavo, caratterizzato da una evidente depressione centrale, e per la forma arcuata in pianta (cfr. inserto 4 in tav. 1): conservano diffusamente sedimenti siltoso-argillosi con indice di colore 5 yr 4/6 e spessore variabile tra 2 e 5 m. particolarmente significativo è il lembo su cui si sviluppa cascina long (stop 2.9 in carraro et al, 2005), dove i sedimenti fluviali siltosi, con spessore fino a circa 5 m, coprono una evidente superficie d’erosione concava modellata sul substrato marino. nel relitto di torre (stop 2.10 in carraro et al, 2005), alla base dei sedimenti siltosi, si osservano corpi lenticolari di sedimenti fluviali sabbioso-ghiaiosi, con spessore di alcuni metri: i ciottoli, con diametro da centimetrico a decimetrico, sono costituiti da serpentiniti, prasiniti, anfiboliti, gabbri, peridotiti, quarziti e calcari; i depositi ghiaiosi contengono numerose concrezioni carbonatiche subsferiche con diametro centimetrico. 12n, 13n e 14n le unità di villa morano, di bric delle ghiaie e dell’eremo comprendono un numero ridotto di lembi conservati esclusivamente sul versante nordoccidentale rispettivamente tra 500 e 490 m, tra 540 e 520 e tra 630 e 600. i lembi, con estensione modesta di poche decine di m2, appaiono sensibilmente rimodellati e dissecati, con la conseguenza che risultano più difficoltose e incerte la loro correlazione e attribuzione alle diverse unità: in particolare i lembi riferibili all’unità 12n appaiono molto allungati e con larghezza ridotta. i diversi lembi, risultano modellati nei sedimenti marini del substrato, su cui in genere si sviluppa un suolo con spessore visibile di alcuni metri e indice di colore medio 2.5 yr 4/4÷4/6. infine, nella fascia altimetrica superiore del versante, lungo lo spartiacque principale, sono riconoscibili settori subpianeggianti, sviluppati tra il colle della maddalena (q. 715) e la basilica di superga (q. 669) (fig. 4). a causa della sensibile ondulazione, della ridotta estensione e dell’assenza di sedimenti fluviali non è possibile ricostruire l’originaria morfologia di questi settori e pertanto chiarire se siano interpretabili come lembi di superfici terrazzate, intensamente rimodellati e dissecati, o semplicemente come rilievi; nel settore della basilica di superga sono inoltre documentati estesi interventi antropici che hanno sensibilmente modificato la morfologia originaria: per tali motivi queste forme non sono state inserite in alcuna unità e differenziate solo dove conservano relitti di suoli e/o prodotti colluviali molto evoluti. 5. considerazioni conclusive lo studio sistematico dei versanti occidentale e nordoccidentale del rilievo collinare, effettuato attraverso la cartografia e l’analisi dettagliata delle forme e dei depositi quaternari, conferma la diffusa conservazione di relitti di modellamento fluviale (fig. 4): si osservano in particolare numerosi lembi di superfici pianeggianti (cfr. inserto 6 in tav. 1) in corrispondenza alla maggior parte dei quali sono conservati sedimenti fluviali sabbioso-siltosi (fig. 5); solo localmente, nella fascia altimetrica superiore del versante occidentale, sono presenti alcuni relitti di meandri incastrati (cfr. inserto 4 in tav. 1), a cui sono associati sedimenti ghiaiosi. la distribuzione di queste evidenze su diverse fasce altimetriche ne consente l’interpretazione come una successione fluviale terrazzata costituita da diverse unità informali, definite con criteri allostratigrafici (cfr. inserti 5 e 7 in tav. 1). come già indicato in precedenti contributi la successione è attualmente conservata in corrispondenza al settore collinare a seguito di una sensibile deformazione sinmorfogenetica (boano et al., 2004). per individuare i diversi termini costituenti la successione presa in esame sono state effettuate correlazioni utilizzando la continuità laterale degli elementi morfologici, la loro distribuzione altimetrica e i caratteri tessiturali e pedogenetici dei sedimenti fluviali localmente presenti; questi elementi sono stati integrati con un insieme di evidenze riguardanti le aree limitrofe. la risposta coerente fornita dai diversi tipi di osservazioni suggerisce come, nel caso specifico, la deformazione, sia confrontabile a parità di fascia altimetrica e non alteri i rapporti geometrici tre le diverse fasce. sono state così individuate nove unità informali nel versante occidentale e dodici nel versante nordoccidentale (cfr. inserti 5 e 7 in tav. 1): in particolare nelle fasce altimetriche più elevate le forme appaiono più rimodellate e conservano depositi con maggior grado di alterazione; nelle fasce altimetriche inferiori le forme risultano invece meno rimodellate e i depositi sensibilmente meno alterati. lo studio pedostratigrafico dei sedimenti fluviali associati alle forme descritte, calibrato su scala pedostratigrafica locale (arduino et al., 1984), consente di collocare cronologicamente l’intera successione terrazzata tra la parte inferiore del pleistocene medio e la fine del pleistocene superiore: in accordo con questo riferimento è la presenza su alcune unità inferiori del versante occidentale di una copertura di loess riferito, su base paleontologica, alla parte superiore del pleistocene superiore (forno, 1979; 1990). le variazioni altimetriche all’interno delle singole unità, con entità di poche decine di metri, possono essere attribuite in parte all’inclinazione originaria delle superfici, secondo il gradiente del corso d’acqua responsabile del modellamento, e in parte al diverso grado di rimodellamento (fig. 7). la successione fluviale presa in esame è da collegare essenzialmente al sensibile approfondimento erosionale operato entro al rilievo dall’antico reticolato idrografico, in risposta al contemporaneo sollevamento: a tale fenomeno è connessa la formazione delle scarpate modellate nel substrato terziario, con altezza di alcune decine di metri, che separano le diverse unità terrazzate (fig. 8). la genesi delle superfici pianeggianti è da collegare, invece, a fenomeni di erosione laterale associati a episodi di modesta sedimentazione, che interrompono il trend erosionale dominante: in questo contesto la maggiore estensione di alcuni lembi conservati nel versante nordoccidentale, come ad esempio quelli relativi all’unità di v. sambuelli (8n), è indicativa di un più importante episodio di erosione areale da parte del reticolato idrografico. lo sviluppo preferenziale degli elementi fluviali secondo direttrici s-n e se-nw, circa paralleli allo 131la successione fluviale pleistocenica ... spartiacque principale e non collegabili all’andamento dei corsi d’acqua che attualmente incidono il rilievo, suggerisce il riferimento della successione presa in esame ad un precedente reticolato idrografico caratterizzato da gradienti modesti, con decorso parallelo al margine collinare. le ridotte dimensioni dei lembi conservati sono invece indicative di una dissezione da parte del reticolato idrografico attuale, circa ortogonale rispetto al precedente e caratterizzato da sensibili gradienti. malgrado la distribuzione della successione fluviale sia prossima all’attuale alveo del f. po e abbia un andamento ad esso circa parallelo, non è possibile riferirla a quest’ultimo corso d’acqua: i dati riguardanti l’andamento del reticolato idrografico piemontese sono infatti concordi nell’indicare che durante il pleistocene medio e il pleistocene superiore il f. po defluiva in corrispondenza al versante meridionale della collina di torino (forno, 1980; 1982; compagnoni & forno, 1992). partendo dall’osservazione che gli attuali conoidi alpini occupano gran parte della pianura e in particolare lambiscono i versanti collinari (fig. 9), sembra invece verosimile ipotizzare come la successione terrazzata descritta sia formata da lembi originariamente appartenenti al settore distale di tali conoidi: i lembi relitti, coinvolti nell’intensa deformazione collinare, avrebbero successivamente perso l’originaria continuità con la pianura. considerando la successione con maggiore dettaglio si può effettuare una distinzione tra due settori altimetrici differenti, indicati rispettivamente come a e b (cfr. inserto 5 di tav. 1), comprendenti ognuno una successione di unità. per il settore altimetrico superiore (a) le unità mostrano caratteristiche diverse tra il versante occidentale (unità 8w÷10w) e quello nordoccidentale (unità 6n÷14n) per quanto riguarda il numero di unità ricostruibili, la distribuzione altimetrica dei lembi e l’inclinazione complessiva, rispettivamente verso s e verso nw; inoltre, esclusivamente per il versante occidentale, è possibile effettuare una correlazione dei lembi fluviali con quelli conservati nel versante meridionale e si ha la locale presenza di relitti di meandri incastrati (11w). l’insieme di questi elementi consente di ipotizzare che le successioni rinvenute nei due versanti non siano tra loro correlabili e suggerisce come durante il modellamento della parte più antica della successione, riferita a gran parte del pleistocene medio, il rilievo fosse di pertinenza di due distinti bacini idrografici drenanti rispettivamente verso sud per il versante occidentale e verso ne per quello nordoccidentale. a confermare tale ipotesi sono la continuità tra le forme e i depositi del versante occidentale con quelli del versante meridionale descritti in compagnoni & forno (1992) e i dati mineralogici sintetizzati più avanti. per il settore altimetrico inferiore (b) (cfr. inserto 5 in tav. 1) la continuità laterale delle forme e l’inclinazione confrontabile verso n-ne per entrambi i versanti (unità 1÷5) indica invece una buona correlabilità tra gli elementi conservati nei due settori: tale osservazione consente di ipotizzare che nel pleistocene superiore l’intera area sia venuta a fare parte di un unico bacino drenato da un corso d’acqua con deflusso verso ne. non esiste invece continuità con le forme del versante meridionale, rispetto alle quali sono separate da uno spartiacque corrispondente alla dorsale di moncalieri. di interpretazione problematica è infine la mancanza di lembi fluviali nel settore di valsalice sviluppato in corrispondenza del limite fra i versanti occidentale e nordoccidentale, caratterizzato da un particolare assetto geologico per la presenza di evidenti discontinuità strutturali, tuttora in corso di studio. le evidenze morfologiche suggeriscono che tale settore sia interessato da un’intensa erosione da parte del reticolato idrografico attuale e da estesi fenomeni gravitativi: questa evoluzione impedisce di chiarire se esso abbia rappresentato per lungo tempo un settore di spartiacque fra i due versanti interessati dal modellamento fluviale o se vi fossero lembi fluviali attribuibili a uno dei due versanti, in seguito cancellati. dalle considerazioni precedentemente esposte, integrate con i risultati delle analisi mineralogiche dei depositi fluviali tuttora in corso (forno et al., 2002), è possibile individuare come bacino di provenienza della successione fluviale descritta i bacini alpini occidentali, con un apporto principalmente dai fiumi dora riparia e stura di lanzo, e proporre un’ipotesi interpretativa dei bacini di provenienza dei diversi elementi che la costituiscono (cfr. inserti 2 e 3 in tav. 1). 132 fig. 9 gli estesi conoidi legati ai corsi d’acqua alpini, attuali affluenti di sinistra del f. po, lambiscono il margine settentrionale della collina di torino, visibile in primo piano. the wide alpine aprons connected to the alpine watercourses tributary of the river po lap the northern margin of the collina di torino, in the foreground. g. forno & s. lucchesi fig. 8 il lembo di superficie terrazzata del monte dei cappuccini (q. 284, unità 2) appare sospeso rispetto all’alveo attuale del f. po tramite una scarpata con altezza di circa 50 m. the monte dei cappuccini terraced surface (q. 284, unit 2) appears suspended from the present river po by a 50 metreshigh scarp. la successione terrazzata descritta in origine costituiva quindi il settore distale dei conoidi alpini che lambivano il margine della collina di torino, in intenso sollevamento. i lembi di questi conoidi conservati nell’area di pianura (compresi in piccola parte in tav. 1 sulla sinistra del f. po) hanno mantenuto sostanzialmente le caratteristiche originarie; i lembi conservati invece nell’area collinare sono stati progressivamente coinvolti nel sollevamento del rilievo e sensibilmente deformati, fino a raggiungere l’attuale sviluppo altimetrico, sospeso rispetto alla pianura; contemporaneamente a questa evoluzione le superfici sono state dissecate dal reticolato idrografico che si organizzava progressivamente nel settore collinare, fino ad assumere l’attuale conservazione in lembi relitti. inizialmente, fino a gran parte del pleistocene medio, nel settore in esame erano presenti almeno due corsi d’acqua principali che defluivano rispettivamente verso sw e ne; successivamente, durante il pleistocene superiore, anche il corso d’acqua più meridionale deviò il proprio corso, andando verosimilmente a confluire con quello più settentrionale. il settore collinare esaminato è stato quindi interessato da una profonda modificazione dell’assetto geologico, indotta dall’evoluzione geodinamica: da area inizialmente appartenente alla pianura padana, caratterizzata dal prevalere dell’erosione areale accompagnata da una limitata sedimentazione fluviale, è venuta a fare parte dell’area collinare, interessata invece dal prevalere dell’approfondimento erosionale. un ulteriore elemento che può avere concorso all’attuale assetto altimetrico della successione fluviale riguarda la possibile deformazione differenziale tra il settore settentrionale e quello meridionale del rilievo: si può ipotizzare che tale comportamento differenziale abbia, in un primo tempo, favorito l’esistenza di due diversi bacini idrografici e, in un secondo tempo, deformato in modo differenziale la successione fluviale sui due versanti. la ricostruzione proposta è inquadrabile nell’ambito dell’evoluzione cinematica recente che ha coinvolto la collina di torino, rappresentata in particolare dallo sviluppo di due fenomeni tra loro strettamente connessi: il progressivo sollevamento dell’edificio strutturale della collina di torino e la migrazione verso nw del suo margine esterno (fig. 10). confrontando il riferimento cronologico della successione fluviale con la sua distribuzione altimetrica, e quindi con il dislivello di circa 400 m che essa mostra, è possibile stimare che tra il pleistocene medio e l’olocene si sia verificato un sollevamento con velocità media di circa 1 mm/anno. i tassi di sollevamento così ottenuti sono congruenti con i valori desunti dalle livellazioni geodetiche relative al primo sessantennio dello scorso secolo (arca & beretta, 1985), che individuano nei rilievi collinari i valori di massimo sollevamento dell’intera area piemontese (> 3 mm/anno). la presenza, entro la successione terrazzata descritta, di scarpate di erosione con entità diversa per le diverse fasce altimetriche consente di ipotizzare che tale tasso di sollevamento non sia stato costante nel tempo, ma che si siano succeduti momenti di minore o maggiore attività geodinamica. ringraziamenti si ringrazia il professor f. carraro per la lettura critica del manoscritto e gli utili suggerimenti forniti. lavori citati arca s. & beretta g. (1985) prima sintesi geodeticageologica sui movimenti verticali del suolo nell’italia settentrionale (1897-1957). boll. geod. sc. aff. , 2, 125-156. arduino e., barberis e., carraro f. & forno m. g. (1984) estimating relative ages from ironoxide/total-iron ratios of soils in the western po valley, italy. geoderma, 33, 39-52, amsterdam. boano p. & forno m. g. (1997) evoluzione morfologica quaternaria del versante occidentale della collina di torino. geoitalia, 1° forum italiano di scienze della terra della fist (bellaria, 5-9 ottobre 1997), 2, 221-222. boano p., carraro f., forno m. g., giardino m., lozar f., lucchesi s., perotto a., piana f. & polino r. (2000) l’evoluzione recente della collina di torino: un esempio di interazione tra attività geodinamica e morfogenesi. in: carulli g. b. & longo salvator g. (eds.) riassunti delle comunicazioni orali e dei posters della 80a riunione estiva della società geologica italiana (trieste, 6-8 settembre 2000). ed. univ. trieste, 81-83. boano p., forno m. g. & lucchesi s. (2002) deformazione pleistocenica della collina di torino dedotta dal modellamento della successione fluviale. in: fioraso g., malusà m., mosca p. & tallone s. (eds.) riassunti della 81a riunione estiva della società geologica ital iana “cinematiche collisionali: tra esumazione e sedimentazione” (torino, 10-12 settembre 2002). litografia geda, nichelino (to), 52-53. boano p., forno m. g. & lucchesi s. (2004) pleistocene deformation of the collina di torino inferred from the modelling of their fluvial succes133 fig. 10 la sella in contropendenza che separa il lembo terrazzato del monte dei cappuccini dal resto del rilievo, connessa con l’incisione fluviale riferibile all’unità 1, suggerisce che il sollevamento della collina di torino e la migrazione del suo margine settentrionale determinino il progressivo inglobamento nel rilievo di settori inizialmente di pianura. the position of the monte dei cappuccini terraced surface, separated by an evident fluvial cut from the relief (unit 1), suggest that the uplift of the collina di torino and the migration of its northern margin produced the progressive embedding in the relief of initial plain areas. la successione fluviale pleistocenica ... sion. il quaternario, it. journ. quat. sc., 17, 145150. bonsignore g., bortolami g. c., elter g., montrasio a., petrucci f., ragni u., sacchi r. & zanella e. (1969) note illustrative della carta geologica d’italia alla scala 1:100.000, fogli 56 e 57 “torino” e “vercelli”, iia ed., serv. geol. it., roma. bortolami g. c., crema g. c., malaroda r., petrucci f., sacchi r., sturani c., tagliavini s. & venzo s. (1969) foglio 56 “torino” della carta geologica d’italia alla scala 1:100.000. iia ed., serv. geol. it., roma. carraro f. (1976) diversione pleistocenica nel deflusso del bacino piemontese meridionale: un’ipotesi di lavoro. gr. st. quat. pad., 3, 89-100. carraro f., forno m. g. & valpreda e. (1982) field trip in northern italy. guidebook. september 15th. piedmont: asti area . i .g.c.p. 73/1/24 pr. quaternary glaciations in the northern hemisphere. final session. september 1/17th 1982. franceitaly. litografia massaza & sinchetto, 24 pp. carraro f., forno m. g., ricci b. & valpreda e. (1987) neotectonic map of italy (scale 1: 500.000): foglio1. in: ambrosetti p., bosi c., carraro f., ciaranfi n., panizza m., papani g., vezzani l. & zanferrari a. (eds.) neotectonic map of italy. c.n.r., progetto finalizzato geodinamica. litografia artistica cartografica, firenze. carraro f., collo g., forno m. g., giardino m., maraga f., perotto a. & tropeano d. (1994) l'evoluzione del reticolato idrografico del piemonte centrale in relazione alla mobilità quaternaria. in: polino r. & sacchi r. (eds.) atti del convegno "rapporti alpi-appennino" e guide alle escursioni peveragno (cn), 31 maggio-1 giugno 1994. ac. naz. sc., 14, 445-461. carraro f., forno m. g., giardino m. & paro l. (2005) field trip guide.14th meeting of the association of european geological societies, september 23th 2005, torino hill. il quaternario, it. journ. quat. sc., 18 (2), 3-55. consiglio nazionale delle ricerche (1990) structural model of italy, scale 1:500.000, sheet 1. progetto finalizzato geodinamica, s.e.l.c.a., firenze. compagnoni r. & forno m. g. (1992) significato geologico di depositi fluviali ghiaiosi pleistocenici medi nella collina di torino. il quaternario, it. journ. quat. sc., 5, 105-122. forno m. g. (1979) il loess della collina di torino. revisione della sua distribuzione e della sua interpretazione genetica e cronologica. geogr. fis. dinam. quat., 2, 105-124. forno m. g. (1980) evidenza di un drenaggio abbandonato nel settore settentrionale dell’altopiano di poirino (prov. di torino). geogr. fis. dinam. quat., 3, 61-65. forno m. g. (1982) studio geologico dell’altopiano di poirino. geogr. fis. din. quat., 5, 129-162. forno m. g. (1990) aeolian and reworked loess in the turin hil ls (northwestern italy). quaternary international, 5, 81-87, oxford. forno m. g., ben g., boano p., bocca p., boero v. & compagnoni r. (2002) lembi di depositi fluviali provenienti dai bacini alpini nordoccidentali sulla collina di torino presso villa gualino (nw italy) il quaternario, it. journ. quat. sc., 15, 175-185. sturani (1975) explanatory notes on western alps (from the sestri-voltaggio line to the val d’ossola). in: ogniben l., parotto m. & praturlon a. (eds), structural model of italy. quad. la ricerca scientifica, 90, 149-174. piana f. & polino r. (1994) la zona transpressiva di rio freddo e l’evoluzione convergente della collina di torino e del monferrato durante il terziario. atti tic. sc. terra, ser. spec., 1, 167180. rizzetto f., mycielska-dowgiallo e. & castiglioni g.b. (1998) some aeolian features in the po plain near este (north italy). geogr. fis. din. quat., 21, 245253. 134 ms. ricevuto il 27 aprile 2005 testo definitivo ricevuto il 19 ottobre 2005 ms. received: aprile 27, 2005 final text received: october 19, 2005 g. forno & s. lucchesi